AU2023290887B2

AU2023290887B2 - Heat-sealable paper and packaging bag

Info

Publication number: AU2023290887B2
Application number: AU2023290887A
Authority: AU
Inventors: Moeka Namioka; Yasutomo Noishiki; Yuta SHAMOTO; Misaki Wakabayashi
Original assignee: Oji Holdings Corp
Current assignee: Oji Holdings Corp
Priority date: 2022-06-14
Filing date: 2023-06-13
Publication date: 2025-07-03
Anticipated expiration: 2043-06-13
Also published as: WO2023243642A1; AU2025238122A1; CN119343498A; EP4541967A1; AU2023290887A1

Description

23 May 2025 2023290887 23 May 2025

DESCRIPTION DESCRIPTION

Title ofof Title Invention: HEAT-SEALABLE Invention: PAPER HEAT-SEALABLE PAPERAND AND PACKAGING BAG PACKAGING BAG

Technical Field Technical Field

[0001]

[0001] 2023290887

Thepresent The present invention invention relates relates to to heat-sealable heat-sealablepaper paper and and aapackaging packaging bag using the bag using the heat-sealable paper. heat-sealable paper.

Background Art Background Art

[0002]

The discussion of the background to the invention herein is intended to facilitate an The discussion of the background to the invention herein is intended to facilitate an

understanding of the invention. However, it should be appreciated that the discussion is not understanding of the invention. However, it should be appreciated that the discussion is not

an an acknowledgement acknowledgement or or admission admission thatthat anyany aspect aspect of of thethe discussion discussion was was part part of of thecommon the common general knowledge general knowledge as atasthe at priority the priority date date ofapplication. of the the application.

[0002a]

Packagesusing Packages usingaaheat heat sealing sealing method methodhave havebeen been widely widely used used forfor packaging packaging foods, foods,

medicines, medical devices, etc., other than packaging general industrial products. medicines, medical devices, etc., other than packaging general industrial products.

[0003]

In recentyears, In recent years,the theproblem problem of plastic of plastic waste waste is getting is getting worse.worse. Of theplastic Of the world's world's plastic production amount, the packaging sector accounts for a large portion of the plastic production amount, the packaging sector accounts for a large portion of the plastic

production amount, production amount,which whichisisone oneofofthe thecauses causesofofplastic plastic waste. Plasticsdodonot waste. Plastics notdecompose decompose semi-permanently, andtheir semi-permanently, and theirgarbage garbageturns turnsinto into microplastics microplastics in in the the natural natural environment, environment,

whichhas which hasaa serious serious adverse adverse effect effect on on the the ecosystem. ecosystem. AsAs a countermeasure, a countermeasure, it has it has been been

proposed to replace plastics with paper. proposed to replace plastics with paper.

[0004]

For example, JP 2022-024664 A discloses water-resistant, oil-resistant, heat-sealable For example, JP 2022-024664 A discloses water-resistant, oil-resistant, heat-sealable

paper that contains a coating layer containing a thermoplastic resin, a wax, and a pigment on paper that contains a coating layer containing a thermoplastic resin, a wax, and a pigment on

at at least least one surfaceofofa apaper one surface paper substrate, substrate, for for the the purpose purpose of providing of providing water-resistant, water-resistant, oil- oil- resistant, heat-sealable paper that has water resistance, oil resistance, and the heat sealing resistant, heat-sealable paper that has water resistance, oil resistance, and the heat sealing

suitability andcan suitability and canbebestored stored forfor a long a long period period of time. of time.

23 May 2025 2023290887 23 May 2025

Summary Summary ofofInvention Invention

[0005]

Theheat-sealable The heat-sealable paper paper described describedin in JP JP 2022-024664 2022-024664 has has an an excellentblocking excellent blocking resistance. However, resistance. However, tearing tearing ofof a abag bagduring duringtransportation transportationororease easeofofopening openingatatthe the time time of openingareare of opening notnot discussed. discussed.

[0006]

[0006] 2023290887

It is desirable to provide heat-sealable paper that can achieve a packaging bag that is It is desirable to provide heat-sealable paper that can achieve a packaging bag that is

difficult to tear and can be easily opened at the time of opening, and a packaging bag difficult to tear and can be easily opened at the time of opening, and a packaging bag

including the heat-sealable paper. including the heat-sealable paper.

[0007]

According to one aspect of the present invention there is provided: According to one aspect of the present invention there is provided:

<1> Heat-sealablepaper <1> Heat-sealable papercomprising comprising one one or or more more heat-sealable heat-sealable layers layers onon atat leastone least onesurface surface of a paper of a papersubstrate, substrate,wherein wherein the heat-sealable layer comprises a water-dispersible resin binder, the heat-sealable layer comprises a water-dispersible resin binder,

aa longitudinal and longitudinal and transverse transverse geometric geometric mean mean of ofindex a tear a tearofindex of the heat-sealable the heat-sealable

2 or more, paper is paper is 10 10 mNm mN.m²/g/g or more, aa burst indexofofthe burst index theheat-sealable heat-sealable paper paper is kPa.m²/g is 3.0 3.0 kPamor 2more, /g or and more, and whentwo when twosuch suchheat-sealable heat-sealablelayers layersare areheat-sealed heat-sealed to to each each other other at at 150C and0.2 150°C and 0.2 MPafor MPa forone onesecond, second,a aheat heatsealing sealing peel peel strength strength is is 2.0 2.0N/15 N/15 mm mm orormore moreand and 1010 N/15 N/15 mm mm or or less. less.

<2> Theheat-sealable <2> The heat-sealablepaper paperaccording accordingtoto<1>, <1>,wherein wherein theheat-sealable the heat-sealablelayer layerfurther further comprises a lubricant. comprises a lubricant.

<3>The <3> Theheat-sealable heat-sealablepaper paperaccording accordingtoto<2>, <2>,wherein wherein thelubricant the lubricantcomprises comprisesat at leastone least one selected from selected the group from the consisting of group consisting of paraffin paraffin wax, wax, carnauba wax,and carnauba wax, andpolyolefin polyolefinwax. wax. <4> Theheat-sealable <4> The heat-sealablepaper paperaccording accordingtoto<2> <2>oror<3>, <3>,wherein wherein a content a content of of thelubricant the lubricantinin the heat-sealable the heat-sealable layer layerisis1% 1% by by mass mass or or more and5% more and 5%bybymass mass or or less. less.

<5>The <5> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone oneofof<1> <1>toto <4>,wherein <4>, wherein a glass a glass transition transition

temperature temperature of of thethe water-dispersible water-dispersible resinresin binderbinder is 0°C is or0C more or andmore 100°Cand 100C or less. or less.

<6>The <6> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone oneofof<1> <1>toto <5>,wherein <5>, wherein thethe water- water-

dispersible resin binder comprises at least one selected from the group consisting of a dispersible resin binder comprises at least one selected from the group consisting of a

styrene-butadiene copolymerand styrene-butadiene copolymer and anan olefin-unsaturatedcarboxylic olefin-unsaturated carboxylicacid acidcopolymer. copolymer. <7>The <7> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone oneofof<2> <2>toto <6>,wherein <6>, wherein thethe water- water-

dispersible resin dispersible resinbinder bindercomprises comprises a a styrene-butadiene styrene-butadiene copolymer, andthe copolymer, and thelubricant lubricant comprisesparaffin comprises paraffin wax. wax.

-- 2a 2a -- 23 May 2025 2023290887 23 May 2025

<8>The <8> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone oneofof<2> <2>toto <6>,wherein <6>, wherein thethe water- water-

dispersible resin dispersible resinbinder bindercomprises comprises an an olefin-unsaturated olefin-unsaturated carboxylic carboxylic acid acid copolymer, andthe copolymer, and the lubricant comprises lubricant carnaubawax. comprises carnauba wax. <9> Theheat-sealable <9> The heat-sealablepaper paperaccording accordingtotoany anyone oneofof<1> <1>toto <8>,wherein <8>, wherein Canadian Canadian standard standard

freeness freeness of of pulp pulp constituting constitutingthe thepaper papersubstrate substrateisis 500 mL 500 mL or ormore more and and 750 mLororless. 750 mL less. <10>The <10> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone oneofof<1> <1> to to <9>, <9>, wherein wherein a main a main 2023290887

component component ofofpulp pulpconstituting constitutingthe thepaper papersubstrate substrate is is needle needle unbleached kraft pulp. unbleached kraft pulp.

<11>The <11> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone one ofof <1> <1> to to <10>, <10>, wherein wherein a value a value (Clark (Clark

stiffness/basis stiffness/basisweight) weight)obtained obtained by by dividing dividing aalongitudinal longitudinaland andtransverse transversegeometric geometric mean of mean of

Clark stiffness of the heat-sealable paper by a basis weight (g/m²) of the2 heat-sealable paper is Clark stiffness of the heat-sealable paper by a basis weight (g/m ) of the heat-sealable paper is 0.20 m2/g or 0.20 m²/g or more moreand and1.20 m2/gororless. 1.20m2/g m²/g less. <12>The <12> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone one ofof <1> <1> to to <11>, <11>, wherein wherein a piercing a piercing

strength of the heat-sealable paper is 10.0 N or more. strength of the heat-sealable paper is 10.0 N or more.

<13>The <13> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone one ofof <1> <1> to to <12>, <12>, wherein wherein a basis a basis weight weight of of g/m² or2 more and 150 g/m² or less. the paper substrate is 50 g/m or more and 150 g/m or less. the paper substrate is 50 g/m2 2

<14>The <14> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone one ofof <1> <1> to to <13>, <13>, wherein wherein a basis a basis weight weight of of the heat-sealable layer is 3 g/m² or2 more and 30 g/m² or less. the heat-sealable layer is 3 g/m or more and 30 g/m or less. 2

<15> <15> Theheat-sealable <15> The The heat-sealablepaper heat-sealable paperaccording paper accordingto according totoany anyone any oneof one ofof <1> <1> <1> toto to <14>, <14>, <14>, wherein wherein wherein a basis aa basis basis weight weight weight of of of the heat-sealable paper is 50 g/m² or 2more and 200 g/m² or less.2 the heat-sealable paper is 50 g/m or more and 200 g/m or less. <16>The <16> Theheat-sealable heat-sealablepaper paperaccording accordingtotoany anyone oneofof<1> <1> to to <15>, <15>, wherein wherein the the paper paper

substrate is extensible paper. substrate is extensible paper.

<17>AApackaging <17> packagingbagbag using using thethe heat-sealable heat-sealable paper paper according according to to any any oneone of of <1><1> to to <16>. <16>.

Description of Description of Embodiments Embodiments

[0008]

Hereinafter, the preferable embodiments of the present invention will be described. Hereinafter, Hereinafter,the preferable the embodiments preferable of theof embodiments present invention the present will be described. invention will be described.

In this In thisdescription, description,"X "XtotoY" Y"showing showing a a range range means means aarange rangeofof "X "Xorormore moreand andY Y or or less". less".

Whennumerical When numerical ranges ranges areare statedstepwise, stated stepwise,the theupper upperand andlower lower limitsofofeach limits eachnumerical numerical range can range can be be combined combinedarbitrarily. arbitrarily. InInthis thisdescription, description, unless unless otherwise otherwise specified, specified, operations operations

and measurements and measurements of of physicalproperties physical propertiesand andthe thelike likeare are performed performedunder underthetheconditions conditionsofof roomtemperature room temperature(20 (20toto25°C)/relative 25C)/relativehumidity humidityofof4040toto50%RH. 50%RH. Further, Further, the term the term

"(meth)acrylic" collectively "(meth)acrylic" collectively refers refers to acrylic to acrylic and and methacrylic. methacrylic.

[0009]

<Heat-sealable paper> <Heat-sealable paper>

Heat-sealable paper Heat-sealable paper of of the the present present embodiment (hereinafter,simply embodiment (hereinafter, simplyreferred referredto to as as "heat-sealable paper") "heat-sealable paper") includes includes onemore one or or heat-sealable more heat-sealable layers onlayers on one at least at least oneofsurface surface a of a paper substrate, wherein the heat-sealable layer comprises a water-dispersible resin binder, a paper substrate, wherein the heat-sealable layer comprises a water-dispersible resin binder, a

longitudinal and transverse geometric mean of a tear index of the heat-sealable paper is 10 longitudinal and transverse geometric mean of a tear index of the heat-sealable paper is 10

mNm2/gorormore, mN.m²/g more, a a burstindex burst indexofofthe theheat-sealable heat-sealable paper paperis is 3.0 3.0 kPam 2 or more, and when /g or more, and when kPa.m²/g kPa.m2/g

two such two suchheat-sealable heat-sealable layers layers are are heat-sealed heat-sealed to toeach each other otheratat150C 150°C and and 0.2 0.2 MPa for one MPa for one second, aa heat second, heat sealing sealing peel peel strength strengthisis 2.0 N/15 2.0 N/15mm or more mm or and10 more and 10N/15 N/15mmmm or less. or less.

According to the heat-sealable paper of the present embodiment, it is possible to obtain a According to the heat-sealable paper of the present embodiment, it is possible to obtain a

packaging bag that is difficult to tear and can be easily opened at the time of opening. packaging bag that is difficult to tear and can be easily opened at the time of opening.

[0010]

The water-dispersible resin binder is used to form a heat-sealable layer, which makes it The water-dispersible resin binder is used to form a heat-sealable layer, which makes it

possible to achieve the heat sealing property. In addition, it is thought that when heat- possible to achieve the heat sealing property. In addition, it is thought that when heat-

sealable paper sealable paper has has a a longitudinal longitudinal and and transverse transverse geometric geometric mean ofaa tear mean of tear index index of of 10 10

mNm2/gorormore, mN.m2/g mN.m²/g more, theheat-sealable the heat-sealablepaper papercan canwithstand withstand shearing shearing due due to to drop drop oror deformation deformation

during transportation and is difficult to tear. Moreover, it is thought that when heat-sealable during transportation and is difficult to tear. Moreover, it is thought that when heat-sealable

2 paper has paper has aa burst burst index index of of 3.0 3.0 kPam kPa.m2/g kPa-m²/g/g or or more, a packaging more, a bagobtained packaging bag obtainedfrom fromthe theheat- heat- sealable paper is prevented from being torn due to drop or the like during transportation. sealable paper is prevented from being torn due to drop or the like during transportation. In In In

addition, it is thought that when heat-sealable paper has a heat sealing peel strength of 2.0 addition, it is thought that when heat-sealable paper has a heat sealing peel strength of 2.0

N/15mm N/15 mmor or more, more, a heat-sealed a heat-sealed portionisisprevented portion preventedfrom from being being damaged damaged due due to drop to drop or or the the like during transportation, and when the heat-sealable paper has a heat sealing peel strength of like during transportation, and when the heat-sealable paper has a heat sealing peel strength of

10 N/15 mm N/15 mm or or less,opening less, openingisiseasily easily performed. performed.Note Note that, that, thethe effectofofthe effect thepresent present invention is invention is not not limited limitedby by the theabove above mechanism. mechanism. In In thethe present present specification,the specification, the longitudinal direction of the heat-sealable paper means a direction corresponding to a longitudinal direction of the heat-sealable paper means a direction corresponding to a

papermaking direction (MD direction) of a paper substrate, and the transverse direction of the papermaking direction (MD direction) of a paper substrate, and the transverse direction of the

heat-sealable paper heat-sealable paper means means aadirection direction corresponding correspondingtotoaa width widthdirection direction (CD (CDdirection) direction) of of the the paper substrate. paper substrate.

[0011]

[Paper substrate]

(Raw materialpulp) (Raw material pulp) The pulp constituting the paper substrate is not particularly limited, and known pulps The pulp constituting the paper substrate is not particularly limited, and known pulps

can be can be used. used. Specifically, Specifically,examples examples thereofinclude thereof includeunbleached unbleached pulps pulps such such as Leaf as Leaf

UnbleachedKraft Unbleached KraftPulp Pulp(LUKP) (LUKP) and and Needle Needle Unbleached Unbleached Kraft(NUKP); Kraft Pulp Pulp (NUKP); chemicalchemical pulps pulps such as such as Leaf BleachedKraft Leaf Bleached KraftPulp Pulp(LBKP) (LBKP)andand Needle Needle Bleached Bleached KraftKraft Pulp Pulp (NBKP); (NBKP);

mechanicalpulps mechanical pulpssuch suchasasGroundwood GroundwoodPulpPulp (GP), (GP), Pressurized Pressurized Groundwood Groundwood Pulp Pulp (PGW), (PGW), Refiner Mechanical Refiner Mechanical Pulp Pulp(RMP), (RMP), ThermoMechanical Pulp (TMP), ThermoMechanical Pulp (TMP), ChemiThermoMechanical ChemiThermoMechanical

Pulp (CTMP), Pulp ChemiMechanicalPulp (CTMP), ChemiMechanical Pulp(CMP), (CMP),and andChemiGroundwood ChemiGroundwood Pulp Pulp (CGP); (CGP); waste waste

paper pulps; paper pulps; non-wood non-woodfiber fiberpulps pulpssuch suchasaskenaf, kenaf,bagasse, bagasse,bamboo, bamboo,andand cotton; cotton; and and synthetic synthetic

pulps. These pulps. These pulps pulps maymay be used be used individually individually by one by one typetype or combination or in in combination of two of two or more or more

types. Among types. Among them, them, at least at least oneone selected selected from from thethe group group consisting consisting of of Leaf Leaf Unbleached Unbleached

Kraft Pulp Kraft (LUKP),Needle Pulp (LUKP), Needle Unbleached Unbleached Kraft Kraft PulpPulp (NUKP), (NUKP), Leaf Bleached Leaf Bleached Kraft Kraft Pulp Pulp (LBKP),and (LBKP), andNeedle Needle Bleached Bleached Kraft Kraft Pulp Pulp (NBKP) (NBKP) is preferable, is preferable, at least at least oneone selected selected from from thethe

group consisting group consisting of of Leaf UnbleachedKraft Leaf Unbleached KraftPulp Pulp(LUKP) (LUKP) and and Needle Needle Unbleached Unbleached Kraft Kraft Pulp Pulp

(NUKP) (NUKP) is ismore more preferable,and preferable, andNeedle Needle Unbleached Unbleached Kraft Kraft PulpPulp (NUKP) (NUKP) is still is still moremore

preferable. preferable.

[0012]

A main A maincomponent componentof of pulp pulp constituting constituting thepaper the paper substrateused substrate usedininthe theheat-sealable heat-sealable paper of paper of the the present present embodiment embodiment isispreferably preferablysoftwood softwoodpulp, pulp,and andisismore morepreferably preferablyNeedle Needle UnbleachedKraft Unbleached KraftPulp Pulp(NUKP). (NUKP). The "main The "main component component of pulp constituting of pulp constituting the the paper paper substrate is softwood pulp" means that the content of softwood pulp in pulp constituting the substrate is softwood pulp" means that the content of softwood pulp in pulp constituting the

paper substrate paper substrate is is more more than than 50% bymass, 50% by mass,and andthe thecontent contentofofthe thesoftwood softwoodpulp pulpisispreferably preferably 80% 80% bybymass massoror more, more, more more preferably preferably 90%90% by mass by mass or more, or more, and still and still moremore preferably preferably 100%100%

by mass. by mass. Similarly, Similarly, the"main the "main component component of pulp of pulp constituting constituting the the paper paper substrate substrate is is needle needle

unbleachedkraft unbleached kraft pulp" pulp" means meansthat thatthe thecontent contentof of needle needle unbleached unbleachedkraft kraftpulp pulpinin pulp pulp constituting the constituting the paper paper substrate substrateisis more morethan than50% by mass, 50% by mass, and andthe the content content of of the the needle needle

unbleachedkraft unbleached kraft pulp pulp is is preferably preferably 80% bymass 80% by massorormore, more,more more preferably preferably 90%90% by mass by mass or or more, and more, andstill still more more preferably preferably 100% bymass. 100% by mass.The The average average fiberfiber length length of softwood of softwood pulp pulp is is long, and use of a paper substrate containing softwood pulp as raw material pulp is preferable long, and use of a paper substrate containing softwood pulp as raw material pulp is preferable

because heat-sealable paper that has desirable tear index and burst index can be obtained. because becauseheat-sealable heat-sealablepaper thatthat paper has desirable tear index has desirable tearand burstand index index can index burst be obtained. In can be obtained. In In addition, use addition, use of of Needle Needle Unbleached KraftPulp Unbleached Kraft Pulp(NUKP) (NUKP) as pulp as pulp constituting constituting a paper a paper substrate substrate

is advantageous because the strength of the pulp fiber itself is higher than that of Needle is advantageous because the strength of the pulp fiber itself is higher than that of Needle

BleachedKraft Bleached KraftPulp Pulp(NBKP) (NBKP) or Leaf or Leaf Unbleached Unbleached KraftKraft Pulp Pulp (LUKP), (LUKP), andthe and thus thus the obtained obtained

paper substrate has higher strength and elongation. paper substrate has higher strength and elongation.

[0013]

Thesoftwood The softwoodpulp pulpisispreferably preferablypulp pulpobtained obtainedfrom fromatatleast least one one or or more moreselected selectedfrom from the group the consisting of group consisting of Douglas fir and Douglas fir and pine pine tree, tree,and and isismore more preferably preferablypulp pulp obtained obtained from from

Douglas fir, from the viewpoint of obtaining heat-sealable paper having desirable tear index Douglas Douglasfir, fir,from thethe from viewpoint of obtaining viewpoint heat-sealable of obtaining paper having heat-sealable desirable paper having tear index tear index desirable

and burst index. and burst index.

[0014]

Theraw The rawmaterial materialpulp pulpconstituting constituting the the paper paper substrate substrate preferably preferably contains contains one one or or more more

selected from selected the group from the consisting of group consisting of bleached kraft pulp bleached kraft pulp and and unbleached kraft pulp, unbleached kraft pulp, and more and more

preferably contains preferably contains unbleached kraft pulp. unbleached kraft pulp.

[0015]

(Canadian standardfreeness) (Canadian standard freeness) The beating degree of the raw material pulp constituting the paper substrate is not The beating degree of the raw material pulp constituting the paper substrate is not

specifically limited. specifically Fromthe limited. From theviewpoint viewpointofofobtaining obtainingheat-sealable heat-sealablepaper paperhaving havingdesirable desirable tear index tear index and and burst burst index, index, the theCanadian standard freeness Canadian standard freeness (CSF) is preferably (CSF) is preferably 500 mLoror 500 mL

moreand more andmore morepreferably preferably550 550 mL mL or more, or more, and and is preferably is preferably 750750 mLless mL or or less and and moremore preferably 700 preferably mLororless. 700 mL less. Moreover, Moreover, the the smoothness smoothness of the of the surface surface of paper of paper becomes becomes good good and the printability can be maintained. and the printability can be maintained.

TheCSF The CSFisismeasured measured according according to to JISJIS P 8121-2:2012 P 8121-2:2012 "Pulp-Freeness "Pulp-Freeness test test method- method-

Chapter2: Chapter 2: Canadian Canadianstandard standardfreeness freenessmethod". method".

[0016]

(Kappa number) (Kappa number)

Thepulp The pulpconstituting constituting the the paper paper substrate substrate preferably preferably has has aa kappa kappa number asmeasured number as measured in accordance in withJIS accordance with JIS PP 8211:2011 8211:2011ofof3030orormore, more,and and preferably6060 preferably oror less,more less, morepreferably preferably 55 or less, further preferably 50 or less, further preferably 46 or less, for obtaining heat- 55 or less, further preferably 50 or less, further preferably 46 or less, for obtaining heat-

sealable paper sealable paper having impactresistance having impact resistance and and workability. workability. TheThe kappa kappa number number of pulp of the the pulp constituting the constituting the paper paper substrate substrateisis measured measured in inaccordance accordance with with JIS JIS P P 8211:2011, usingaa 8211:2011, using

paper substrate paper substrate pulp pulp disintegrated disintegrated in inaccordance accordance with with JIS JIS P P 8220-1:2012 asaasample. 8220-1:2012 as sample.

[0017]

(Basis weight) (Basis weight)

The basis weight of the paper substrate is not specifically limited, but is preferably 50 The basis weight of the paper substrate is not specifically limited, but is preferably 50

g/m2 or g/m2 g/m² or more, more, more morepreferably preferably6060g/m² 2 more, and still more preferably 70 g/m² or g/moror more, and still more preferably 70 g/m2 ormore, more, and is preferably 150 g/m² or 2less, more preferably 120 g/m² or less,2 still more preferably 110 and is preferably 150 g/m or less, more preferably 120 g/m or less, still more preferably 110 g/m² 2or less, and even still more preferably 100 g/m² or less, 2 from the viewpoint of obtaining g/m or less, and even still more preferably 100 g/m or less, from the viewpoint of obtaining heat-sealable paper heat-sealable paper having desirable tear having desirable tear index index and and burst burst index. Thebasis index. The basisweight weightofofthe the paper substrate paper substrate is is measured in accordance measured in withJIS accordance with JISPP8124:2011. 8124:2011.

[0018]

(Thickness) (Thickness)

Thethickness The thickness of of the the paper substrate is paper substrate ispreferably 60m preferably60 µm or um or more, morepreferably more, more preferably80 80 m um ormore, µm or more,and andstill still more preferably 100 more preferably 100ummorormore, µm more,andand is ispreferably preferably200 µmm 200um or or less, less,

morepreferably more preferably180 m 180um µm or or less,and less, andstill still more preferably 160 more preferably mororless, 160 um µm less, from fromthe the viewpoint viewpoint of obtaining of obtaining heat-sealable heat-sealable paper paper having desirable tear having desirable tear index index and and burst burst index. Thethickness index. The thickness of the of the paper paper substrate substrate is ismeasured measured in in accordance with JIS accordance with JIS PP 8118:2014. 8118:2014.

[0019]

(Density) (Density) 3 or more and more preferably Thedensity The density of of the the paper substrate isispreferably paper substrate preferably0.3 0.3g/cm g/cm³or more and more preferably 3 more, and is preferably 1.0 g/cm³ or less, 3 3 0.5 g/cm or more, and is preferably 1.0 g/cm or less, more preferably 0.9 g/cm or less, and 0.5 g/cm³ or more preferably 0.9 g/cm³ or less, and

still more preferably 0.75 g/cm³ or 3less, from the viewpoint of obtaining heat-sealable paper still more preferably 0.75 g/cm or less, from the viewpoint of obtaining heat-sealable paper having desirable having desirable tear tear index index and and burst burst index index and from the and from the viewpoint viewpointofof formability. formability. TheThe density of the paper substrate is calculated from the basis weight and the thickness of the density of the paper substrate is calculated from the basis weight and the thickness of the

paper substrate paper substrate obtained by the obtained by the aforementioned measurement aforementioned measurement methods. methods.

[0020]

(Optional components) (Optional components)

Thepaper The papersubstrate substrate may maycontain containoptional optionalcomponents components including including internal internal additivessuch additives such as anionic, cationic, or amphoteric retention aids, drainage aids, dry paper strength additives, as anionic, cationic, or amphoteric retention aids, drainage aids, dry paper strength additives,

wet paper strength additives, sizing agents, fixing agents, and fillers, waterproofing agents, wet paper strength additives, sizing agents, fixing agents, and fillers, waterproofing agents,

dyes, and fluorescent whitening agents, as required. dyes, and fluorescent whitening agents, as required.

[0021]

Examplesofofthe Examples thedry drypaper paperstrength strengthadditives additivesinclude includecationized cationizedstarch, starch, polyacrylamide, polyacrylamide,

carboxymethylcellulose, carboxymethylcellulose, carboxymethylcellulose and and and the the the like.The like. like. The The content content content of thethe of the of dry dry dry paper paper paper strength strength strength additives additives additives isis is not not not

specifically limited and is preferably 3.0 mass% or less per raw material pulp (absolute dry specifically limited and is preferably 3.0 mass% or less per raw material pulp (absolute dry

mass). mass).

[0022]

Examplesofofthe Examples thewet wetpaper paperstrength strengthadditives additivesinclude includepolyamide polyamidepolyamine polyamine epichlorohydrin, urea epichlorohydrin, urea formaldehyde formaldehyderesin, resin,melamine melamine formaldehyde formaldehyde resin, resin, andand the the like.The like. The content of the wet paper strength additive is not specifically limited, but is preferably 3.0% by content of the wet paper strength additive is not specifically limited, but is preferably 3.0% by

mass or less per raw material pulp (absolute dry mass). mass or less per raw material pulp (absolute dry mass).

[0023]

Examples of the sizing agents include internal sizing agents such as rosin sizing agents, Examples of the sizing agents include internal sizing agents such as rosin sizing agents,

synthetic sizing agents, petroleum resin sizing agents, and the like, and surface sizing agents synthetic sizing agents, petroleum resin sizing agents, and the like, and surface sizing agents

such as such as styrene/acrylic styrene/acrylic acid acid copolymers, copolymers, styrene/methacrylic acid copolymers, styrene/methacrylic acid copolymers,and andthe thelike. like. The content of the sizing agents is not specifically limited and is preferably 3.0 mass% or less The content of the sizing agents is not specifically limited and is preferably 3.0 mass% or less

per raw per material pulp raw material pulp (absolute (absolute dry dry mass). mass).

[0024]

Examplesofoffixing Examples fixingagents agentsinclude includealuminum aluminum sulfate,polyethyleneimine, sulfate, polyethyleneimine, andand thethe like. like.

The content of the fixing agents is not specifically limited and is preferably 3.0 mass% or less The content of the fixing agents is not specifically limited and is preferably 3.0 mass% or less

[0025]

Examples of the fillers include inorganic fillers such as talc, kaolin, calcined kaolin, Examples of the fillers include inorganic fillers such as talc, kaolin, calcined kaolin,

calcium carbonate, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, alumina, calcium carbonate, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, alumina,

magnesium magnesium carbonate, carbonate, magnesium magnesium oxide, oxide, silica, silica, white white carbon, carbon, bentonite, bentonite, zeolite,sericite, zeolite, sericite, and and

smectite, and organic fillers such as acrylic resins and vinylidene chloride resins. smectite, and organic fillers such as acrylic resins and vinylidene chloride resins.

[0026]

As the As the paper paper substrate, substrate, Clupak paper (extensible Clupak paper (extensible paper) paper) or or the the like likewhich which has has been been

subjected to subjected to Clupak processingfor Clupak processing for shrinking shrinking paper paperstrip strip may beused, may be used, for for example. example. TheThe

extensible paper refers to paper that has an elongation in the longitudinal direction or in the extensible paper refers to paper that has an elongation in the longitudinal direction or in the transverse direction transverse direction of of5% or more 5% or measuredaccording more measured according to to JISP P8113:2006, JIS 8113:2006, andand examples examples thereof include thereof include kraft kraft paper paper type-5 type-5 Nos. Nos. 11 and and 2 2 described described in in JIS JIS PP 3401:2000. The 3401:2000. The paper paper substrate is preferably Clupak paper (extensible paper) from the viewpoint of obtaining heat- substrate is preferably Clupak paper (extensible paper) from the viewpoint of obtaining heat- sealable paper having desirable Clark stiffness and piercing strength. sealable paper having desirable Clark stiffness and piercing strength.

[0027]

[Heat-sealable layer]

Theheat-sealable The heat-sealable paper paper according accordingtoto this this embodiment comprises embodiment comprises at at leastone least oneheat- heat- sealable layer on at least one surface of the paper substrate. The heat-sealable layer is a sealable layer on at least one surface of the paper substrate. The heat-sealable layer is a

layer that is melted and adheres by heating, ultrasonic waves, or the like. layer that is melted and adheres by heating, ultrasonic waves, or the like.

[0028]

(Water-dispersible resin binder) (Water-dispersible resin binder)

Theheat-sealable The heat-sealable layer layer contains contains a a water-dispersible water-dispersible resin resinbinder. Thewater- binder. The water- dispersible resin binder is a resin binder that is not water-soluble (specifically, the solubility dispersible resin binder is a resin binder that is not water-soluble (specifically, the solubility

in water at 25C is 10 g/L or less) but is finely dispersed in water like an emulsion or a in water at 25°C is 10 g/L or less) but is finely dispersed in water like an emulsion or a

suspension. Aqueous suspension. Aqueous application application of the of the heat-sealable heat-sealable layer layer using using a water-dispersibleresin a water-dispersible resin binder enables heat-sealable paper that is excellent in re-disintegration property and can be binder enables heat-sealable paper that is excellent in re-disintegration property and can be

recycled as recycled as paper to be paper to be obtained. obtained. InInthe thecase casewhere wherethe thewater-dispersible water-dispersibleresin resin binder binder also also corresponds to the following lubricant, it is classified as a lubricant. corresponds to the following lubricant, it is classified as a lubricant.

[0029]

The water-dispersible resin binder is not specifically limited, as long as it exerts the The water-dispersible resin binder is not specifically limited, as long as it exerts the

effects of the present invention, but examples thereof include polyolefin resins (such as effects of the present invention, but examples thereof include polyolefin resins (such as

polyethylene and polypropylene), vinyl chloride resins, styrene resins, styrene-butadiene polyethylene and polypropylene), vinyl chloride resins, styrene resins, styrene-butadiene

copolymers,styrene-unsaturated copolymers, styrene-unsaturatedcarboxylic carboxylicacid acidcopolymers copolymers (such (such as as styrene-(meth)acrylic styrene-(meth)acrylic

acid copolymer), acrylic resins, acrylonitrile-styrene copolymers, acrylonitrile-butadiene acid copolymer), acrylic resins, acrylonitrile-styrene copolymers, acrylonitrile-butadiene

copolymers,ABS copolymers, ABS resins,AAS resins, AAS resins, resins, AESAES resins, resins, vinylidene vinylidene chloride chloride resins,polyurethane resins, polyurethane resins, poly-4-methyl pentene-1 resins, polybutene-1 resins, vinylidene fluoride resins, vinyl resins, poly-4-methyl pentene-1 resins, polybutene-1 resins, vinylidene fluoride resins, vinyl

fluoride resins, fluorine resins, polycarbonate resins, polyamide resins, acetal resins, fluoride resins, fluorine resins, polycarbonate resins, polyamide resins, acetal resins,

polyphenyleneoxide polyphenylene oxideresins, resins,polyester polyester resins resins (such (such as as polyethylene terephthalate and polyethylene terephthalate and

polybutyleneterephthalate), polybutylene terephthalate), polyphenylene sulfide resins, polyphenylene sulfide resins, polyimide resins, polysulfone polyimide resins, polysulfone

resins, polyether sulfone resins, polyarylate resins, olefin-unsaturated carboxylic acid resins, polyether sulfone resins, polyarylate resins, olefin-unsaturated carboxylic acid

copolymers,and copolymers, andmodified modified products products thereof.These thereof. These may may be used be used individually individually bytype by one one or type or maybebeused may usedinincombination combinationofoftwo two typesorormore. types more. Among these, the heat-sealable layer preferably includes at least one selected from the Among these, the heat-sealable layer preferably includes at least one selected from the

group consisting group consisting of of aa styrene-butadiene copolymerand styrene-butadiene copolymer andananolefin-unsaturated olefin-unsaturatedcarboxylic carboxylicacid acid copolymer. copolymer.

Furthermore, the heat-sealable layer preferably includes an olefin-unsaturated Furthermore, the heat-sealable layer preferably includes an olefin-unsaturated

carboxylic acid carboxylic acid copolymer copolymerfrom fromthetheviewpoint viewpoint of of increasingheat increasing heatsealing sealingpeel peelstrength, strength, and and morepreferably more preferablyincludes includesaa styrene-butadiene styrene-butadienecopolymer copolymer from from thethe viewpoint viewpoint of of availability, availability,

cost, and recyclability. cost, and recyclability.

[0030]

Examplesofofthe Examples theolefin-unsaturated olefin-unsaturatedcarboxylic carboxylicacid acidcopolymer copolymer include include anan ethylene- ethylene-

(meth)acrylic acid copolymer (meth)acrylic acid andananethylene-(meth)acrylic copolymer and ethylene-(meth)acrylicacid acidalkyl alkylester ester copolymer. copolymer. Among Among them, them, an an ethylene-(meth)acrylic ethylene-(meth)acrylic acid acid copolymer copolymer is preferably is preferably included, included, andand an an ethylene-acrylic acid ethylene-acrylic acid copolymer is more copolymer is morepreferably preferablyincluded. included. Therefore, the water-dispersible resin binder contained in the heat-sealable layer Therefore, the water-dispersible resin binder contained in the heat-sealable layer

preferably contains at least one selected from the group consisting of a styrene-butadiene preferably contains at least one selected from the group consisting of a styrene-butadiene

copolymerand copolymer andananethylene-(meth)acrylic ethylene-(meth)acrylic acidcopolymer. acid copolymer. Note Note that, that, the olefin-unsaturated the olefin-unsaturated

carboxylic acid carboxylic acid copolymer copolymermay maybe be an an ionomer. ionomer.

[0031]

Thestyrene-butadiene The styrene-butadienecopolymer copolymermaymay be any be any of synthetic of synthetic product product and and commercially commercially

available product, available product, and and examples ofthe examples of the commercially commerciallyavailable availableproduct productinclude includeNipol Nipollatex latex LX407G51,LX407S10, LX407G51, LX407S10, LX407S12, LX407S12, LX410, LX410, LX415M, LX415M, LX416, LX416, LX430,LX430, LX433C, LX433C, 2507H, 2507H, available from available ZeonCorporation, from Zeon Corporation,Nalstar NalstarSR-101, SR-101, SR-102, SR-102, SR-103, SR-103, SR-115, SR-115, and SR-153, and SR-153,

available from available NIPPON from NIPPON A&LA&L INC.,INC., and styrene and styrene butadiene butadiene latex latex 0602 0602 and 0597C, and 0597C, available available

from JSR from JSRCorporation. Corporation.

[0032]

Theethylene-(meth)acrylic The ethylene-(meth)acrylicacid acidcopolymer copolymerto to bebe used used may may be be anyany of synthetic of synthetic

products and products andcommercially commercially availableproducts, available products,and andexamples examples of of thethe commercially commercially available available

products include products includeMP498345N, MP498345N, MP4983R, MP4990R, MP4983R, MP4990R, andand MFHS1279, MFHS1279, available available from from

MichelmanJapan Michelman Japan LLC, LLC,ZAIKTHENE ZAIKTHENE (registered (registered trademark)A Aand trademark) andZAIKTHENE ZAIKTHENE (registered (registered

trademark)AC, trademark) AC,available availablefrom fromSumitomo Sumitomo Seika Seika Chemicals Chemicals Company, Company, Limited, Limited, and and CHEMIPEARL CHEMIPEARL S Series, S Series, available available from from MitsuiMitsui Chemicals, Chemicals, Inc. Inc.

[0033]

The glass transition temperature of the water-dispersible resin binder is preferably 0C The glass transition temperature of the water-dispersible resin binder is preferably 0°C

or more, or morepreferably more, more preferably10°C 10Corormore, more,and and still more still morepreferably preferably15°C 15Corormore. more.WhenWhen the the the

water-dispersible resin binder having a glass transition temperature that is equal to or higher water-dispersible resin binder having a glass transition temperature that is equal to or higher

than the above lower limit is used, the blocking resistance of the heat-sealable paper can be than the above lower limit is used, the blocking resistance of the heat-sealable paper can be

improved.FromFrom improved. the the viewpoint viewpoint of the of the heatheat sealing sealing property, property, thethe glass glass transitiontemperature transition temperature of the water-dispersible resin binder is preferably 100C or less, more preferably 80C or less, of the water-dispersible resin binder is preferably 100°C or less, more preferably 80°C or less,

still more preferably 60C or less, and even still more preferably 50C or less. still more preferably 60°C or less, and even still more preferably 50°C or less.

- 10 --

As the glass transition temperature of the water-dispersible resin binder, a value As the glass transition temperature of the water-dispersible resin binder, a value

measured with a differential scanning calorimeter is used. measured with a differential scanning calorimeter is used.

[0034]

The content of the water-dispersible resin binder in the heat-sealable layer is preferably The content of the water-dispersible resin binder in the heat-sealable layer is preferably

30%bybymass 30% massoror more, more, more more preferably preferably 50%50% by mass by mass or more, or more, stillstill more more preferably preferably 70% 70% by by massor mass or more, more,and andeven evenstill still more preferably 80% more preferably 80%bybymass mass or or more, more, andand is is 100% 100% by mass by mass or or less, less,preferably preferably99% by mass 99% by massoror less, less, and and more preferably 98% more preferably 98%bybymass mass or or less.WhenWhen less. the the

content falls within the above range, the heat-sealable paper having a high heat sealing peel content falls within the above range, the heat-sealable paper having a high heat sealing peel

strength can be obtained. strength can be obtained.

[0035]

That is, according to one embodiment of the present invention, the content of the That is, according to one embodiment of the present invention, the content of the

styrene-butadiene copolymer styrene-butadiene copolymerand/or and/orolefin-unsaturated olefin-unsaturatedcarboxylic carboxylicacid acidcopolymer copolymer (preferably (preferably

ethylene-(meth)acrylic acid ethylene-(meth)acrylic acid copolymer) copolymer)ininthe theheat-sealable heat-sealable layer layer is is preferably preferably 30% by mass 30% by mass or more, or morepreferably more, more preferably50% 50%byby mass mass or or more, more, stillmore still more preferably preferably 70% 70% by mass by mass or more, or more,

and even and evenstill still more more preferably preferably 90% bymass 90% by massorormore, more,and and isis100% 100%by by mass mass or less, or less, preferably preferably

99%bybymass 99% massoror less,and less, andmore morepreferably preferably98% 98% by by mass mass or less. or less. Here, Here, "content "content of A of A and/or and/or

B" refers to the content of A or B when only one of A and B is contained, or refers to the total B" refers to the content of A or B when only one of A and B is contained, or refers to the total

content of content of A and BBwhen A and whenboth bothA A andand B are B are contained. contained.

[0036]

(Lubricant) (Lubricant)

From the viewpoint of imparting the slip property and blocking resistance to the heat- From the viewpoint of imparting the slip property and blocking resistance to the heat-

sealable paper, the heat-sealable layer preferably includes a lubricant in addition to the above sealable paper, the heat-sealable layer preferably includes a lubricant in addition to the above

water-dispersible resin binder. The lubricant is a substance that can reduce the coefficient of water-dispersible resin binder. The lubricant is a substance that can reduce the coefficient of

friction on the surface of the heat-sealable layer by being mixed in the heat-sealable layer. friction on the surface of the heat-sealable layer by being mixed in the heat-sealable layer.

[0037]

The lubricant is not specifically limited, and waxes, metal soaps, fatty acid esters, and The lubricant is not specifically limited, and waxes, metal soaps, fatty acid esters, and

the like can be used, for example. One of the lubricants may be used alone, or two or more the the like likecan canbebe used, for for used, example. Oneof example. One ofthe thelubricants lubricantsmay maybe beused usedalone, alone,or ortwo twoor ormore more

of them of them maybe them may may bebe usedin used used inincombination. combination. combination. Examples Examples Examples ofwaxes of the of the the waxes waxes include include include natural natural natural waxeswaxes waxes

including animal including animalor or plant-derived plant-derived waxes waxes(such (suchasasbeeswax beeswax and and carnauba carnauba wax), wax), mineral mineral waxes waxes

(such as (such as microcrystalline microcrystalline wax), wax), and petroleumwax; and petroleum wax;and andsynthetic syntheticwaxes waxes including including polyolefin polyolefin

wax, paraffin wax, paraffin wax, polyester wax, wax, polyester wax,and andthe the like. like. Examples Examplesof of thethe metal metal soaps soaps include include

calcium stearate, sodium stearate, zinc stearate, aluminum stearate, magnesium stearate, fatty calcium stearate, sodium stearate, zinc stearate, aluminum stearate, magnesium stearate, fatty

acid sodium acid soap,potassium sodium soap, potassiumoleate oleatesoap, soap,castor castor oil oil potassium soap, composites potassium soap, compositesthereof, thereof, and and the like. the Among like. Among thethe above above lubricants, lubricants, paraffinwax, paraffin wax, carnauba carnauba wax, wax, and and polyolefin polyolefin wax wax are are preferable since preferable since the the melting melting point point is iscomparatively comparatively low, low, wax components wax components areeasily are easilyformed formedonon

- 11 --

the surface of the coating layer, and the effect of improving the blocking resistance is the surface of the coating layer, and the effect of improving the blocking resistance is

excellent. That is, the lubricant preferably contains at least one selected from the group excellent. That is, the lubricant preferably contains at least one selected from the group

consisting of consisting of paraffin paraffinwax, wax, carnauba wax, and carnauba wax, andpolyolefin polyolefinwax. wax.FromFrom the the viewpoint viewpoint of of imparting the imparting the slip slip property property and and improving dampproofness, improving dampproofness, thethe lubricantpreferably lubricant preferablycontains contains paraffin wax. paraffin wax.

As carnauba As carnaubawax, wax,a asynthesized synthesizedproduct productorora acommercially commercially available available product product maymay be be used. Examples used. Examples of the of the commercially commercially available available product product include include Selosol Selosol 524 524 available available fromfrom

ChukyoYushi Chukyo YushiCo., Co., Ltd. Ltd.and andMichem Michem Lube Lube 160RPH available from 160RPH available from Michelman. The Michelman. The

paraffin wax paraffin to be wax to be used maybebeany used may anyofofsynthetic syntheticproducts productsand andcommercially commercially available available

products, and products, examplesofofthe and examples thecommercially commercially availableproducts available productsinclude includeHidorin Hidorin L-700 L-700 andand the the the

like, available like, availablefrom from Chukyo YushiCo., Chukyo Yushi Co.,Ltd. Ltd.As As polyethylene polyethylene wax,wax, a synthesized a synthesized product product or or or

a commercially a availableproduct commercially available productmay maybebe used.Examples used. Examples ofcommercially of the the commercially available available

product include product include Aquacer Aquacer531 531available availablefrom from BYK. BYK.

[0038]

Whenthe When thewater-dispersible water-dispersibleresin resinbinder bindercontains containsaa styrene-butadiene styrene-butadienecopolymer, copolymer,the the lubricant preferably lubricant preferably contains contains paraffin paraffinwax. When wax. When thethe water-dispersible water-dispersible resin resin binder binder contains contains

an olefin-unsaturated an olefin-unsaturated carboxylic acid copolymer carboxylic acid (preferablyananethylene-(meth)acrylic copolymer (preferably ethylene-(meth)acrylicacid acid copolymer),the copolymer), the lubricant lubricant preferably preferably contains contains carnauba wax. carnauba wax.

[0039]

When the heat-sealable layer contains a lubricant, the content of the lubricant is When the heat-sealable layer contains a lubricant, the content of the lubricant is

preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, and still preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, and still

morepreferably more preferably11part part by by mass massorormore, more,and andisis preferably preferably 30 30 parts parts by massor by mass or less, less, more more

preferably 10 parts by mass or less, and still more preferably 5 parts by mass or less, relative preferably 10 parts by mass or less, and still more preferably 5 parts by mass or less, relative

to 100 parts by mass of the water-dispersible resin binder. to 100 parts by mass of the water-dispersible resin binder.

[0040]

When the heat-sealable layer contains a lubricant, the content of the lubricant in the When the heat-sealable layer contains a lubricant, the content of the lubricant in the

heat-sealable layer heat-sealable layer is ispreferably preferably0.1% 0.1% by by mass or more, mass or morepreferably more, more preferably0.3% 0.3%bybymass mass or or

more,and more, more, andstill and still more still more preferably more preferably 1% preferably 1% bymass 1% by by massor mass orormore, more,and more, andpreferably and preferably30% preferably 30% 30% by by by mass mass mass or or less, or less, less,

morepreferably more preferably10% 10%byby mass mass or or less,and less, andstill still more preferably5% more preferably 5%bybymass mass or or less. less.

[0041]

In the present embodiment, the heat-sealable layer contains the water-dispersible resin In the present embodiment, the heat-sealable layer contains the water-dispersible resin

binder, and preferably contains the lubricant in addition to the water-dispersible resin binder. binder, and preferably contains the lubricant in addition to the water-dispersible resin binder.

In addition, the heat-sealable layer may contain the water-dispersible resin binder, and, if In addition, the heat-sealable layer may contain the water-dispersible resin binder, and, if

necessary, a pigment in addition to the lubricant. necessary, a pigment in addition to the lubricant.

[0042]

12 12 ---

(Pigment) (Pigment)

In the In the present present embodiment, theheat-sealable embodiment, the heat-sealable layer layer may maycontain containthe theabove abovewater- water- dispersible resin binder, and, if necessary, a pigment in addition to the lubricant. dispersible resin binder, and, if necessary, a pigment in addition to the lubricant. The The problem of the heat-sealable layer-coated surface sticking to the back surface of the heat- problem of the heat-sealable layer-coated surface sticking to the back surface of the heat-

sealable paper sealable paper to to cause cause peeling peeling (blocking) (blocking) is issuppressed suppressed when producingthe when producing theheat-sealable heat-sealable paper by paper by containing containingaa pigment, pigment,SOsothat so that the the heat-sealable heat-sealable paper paper having having excellent excellent blocking blocking

resistance is obtained. resistance is obtained.

[0043]

Thepigment The pigmentisisnot notspecifically specifically limited, limited, and and examples thereof include examples thereof include various various pigments pigments conventionally used conventionally usedfor for pigment pigmentcoating coatinglayers. layers. TheThe pigment pigment may may be used be used alonealone bytype by one one type or may or beused may be usedinin combination combinationofoftwo twoorormore more types.As the types. As the pigment, pigment, the heat-sealable the heat-sealable layer layer layer

preferably contains preferably contains a a pigment havingananaspect pigment having aspectratio ratio of of 20 20 or or more fromthe more from the viewpoint viewpointofofheat heat sealing peel sealing peel strength strength and and blocking blocking resistance. Theaspect resistance. The aspectratio ratio of of the the pigment is more pigment is more

preferably 25 or more, further preferably 30 or more, particularly preferably 60 or more, and preferably 25 or more, further preferably 30 or more, particularly preferably 60 or more, and

is preferably 10,000 or less, more preferably 1,000 or less, further preferably 300 or less, in is preferably 10,000 or less, more preferably 1,000 or less, further preferably 300 or less, in

view of view of the the availability availabilityand andsmoothness of the smoothness of the heat-sealable heat-sealable layer layersurface. Theaspect surface. The aspectratio ratio of the of the pigment meansmajor pigment means majoraxis/minor axis/minor axisandand axis may may be be measured measured by following by the the following method. method.

[0044]

Thepigment The pigmentpreferably preferablycontains containsa alayered layeredinorganic inorganiccompound compound having having an aspect an aspect ratio ratio

of 20 of 20 or or more. The more. The form form of of thethe layered layered inorganic inorganic compound compound is tabular. is tabular. When When the pigment the pigment

is tabular, the protrusion of the pigment from the surface of the heat-sealable layer is is tabular, the protrusion of the pigment from the surface of the heat-sealable layer is

suppressed, and a heat-sealable layer having excellent blocking resistance is obtained, while suppressed, and a heat-sealable layer having excellent blocking resistance is obtained, while

maintaining the heat sealing property. maintaining the heat sealing property.

[0045]

Thepigment The pigmentpreferably preferablyhas hasa alength length(average (averageparticle particle size) size) of 0.1 m of 0.1 um or more µm or and100 more and 100 m um orless. µm or less. When When the the length length is is 0.1 µmm 0.1um or or more, more, thethe pigment pigment is easily is easily arranged arranged in in paralleltoto parallel

the paper substrate. Further, when the length is 100 m or less, there is little concern that a the paper substrate. Further, when the length is 100 um µm or less, there is little concern that a

part of part of the thepigment pigment protrudes protrudes from the heat-sealable from the heat-sealable layer. Thelength layer. The lengthofofthe thepigment pigmentisis morepreferably more preferably0.3 morormore, 0.3 um µm more,further furtherpreferably preferably0.5 morormore, 0.5um µm more,particularly particularlypreferably preferably 1.0 m 1.0 um or more, µm or more,and andisis more morepreferably m preferably3030um µm oror less,further less, further preferably preferably 20 mororless, 20 um µm less, particularly preferably 15 m or less. particularly preferably 15 um µm or less.

[0046]

Here, the length of the pigment when contained in the heat-sealable layer is determined, Here, the length of the pigment when contained in the heat-sealable layer is determined,

as follows. as follows. AnAn enlarged enlarged image image of the of the cross cross section section ofof theheat-sealable the heat-sealablelayer layeris is captured captured

with an with an electron electron microscope. microscope. At At thistime, this time,the themagnification magnificationisissuch suchthat that about about20 20toto 30

- 13 --

pigmentsare pigments are included includedinin the the screen. screen. The The length length ofof eachpigment each pigment in in thethe screen screen isismeasured. measured. Then, the Then, the average averageof of the the lengths lengths obtained is calculated obtained is calculated as asthe thelength lengthofof thethepigment. The pigment. The

length of the pigment may be expressed in terms of particle size. length of the pigment may be expressed in terms of particle size.

[0047]

Thepigment The pigmentpreferably preferablyhas hasa athickness thicknessofof200 200nmnmororless. less.TheThe thickness thickness of of thethe

pigmentisis more pigment morepreferably preferably100 100nmnm or or less,further less, further preferably preferably 80 80 nm nmororless, less, even more even more

preferably 50 nm or less, particularly preferably 30 nm or less. Further, it is preferably 5 nm preferably 50 nm or less, particularly preferably 30 nm or less. Further, it is preferably 5 nm

or more, or morepreferably more, more preferably1010nmnmorormore. more.The The smaller smaller the average the average thickness thickness of the of the pigment, pigment,

the higher the heat sealing peel strength is obtained. Here, the thickness of the pigment the higher the heat sealing peel strength is obtained. Here, the thickness of the pigment

whencontained when containedininthe theheat-sealable heat-sealable layer layer is is determined, determined, as as follows. Anenlarged follows. An enlarged image image of of the cross section of the heat-sealable layer is captured with an electron microscope. At At this this the cross section of the heat-sealable layer is captured with an electron microscope. At this

time, the magnification is such that about 20 to 30 pigments are included in the screen. The time, time, the themagnification magnificationis such that that is such about about 20 to 30 20 pigments are included to 30 pigments are in the screen. included in the screen. The The thickness of thickness of each each pigment in the pigment in the screen screen is is measured. Then, measured. Then, thethe average average of of thethethicknesses thicknesses obtained is calculated as the thickness of the pigment. obtained is calculated as the thickness of the pigment.

[0048]

Specific examples of the pigment include mica, bentonite, kaolin, pyrophyllite, talc, Specific examples of the pigment include mica, bentonite, kaolin, pyrophyllite, talc,

smectite, vermiculite, chlorite, septe chlorite, serpentine, stilpnomelane, montmorillonite, smectite, vermiculite, chlorite, septe chlorite, serpentine, stilpnomelane, montmorillonite,

heavycalcium heavy calciumcarbonate carbonate(ground (ground calcium calcium carbonate), carbonate), lightcalcium light calcium carbonate carbonate (synthetic (synthetic

calciumcarbonate), calcium carbonate), composite compositesynthetic syntheticpigment pigmentofofcalcium calcium carbonate carbonate andand other other hydrophilic hydrophilic

organic compounds, satin white, lithopone, titanium dioxide, silica, barium sulfate, calcium organic compounds, satin white, lithopone, titanium dioxide, silica, barium sulfate, calcium

sulfate, alumina, sulfate, alumina, aluminum hydroxide,zinc aluminum hydroxide, zincoxide, oxide,magnesium magnesium carbonate, carbonate, silicate,colloidal silicate, colloidal silica, plastic pigments of hollow or solid organic pigments, binder pigments, plastic beads, silica, plastic pigments of hollow or solid organic pigments, binder pigments, plastic beads,

microcapsules, and the like, and the heat-sealable layer preferably contains at least one microcapsules, and the like, and the heat-sealable layer preferably contains at least one

selected from the group consisting of the above. selected from the group consisting of the above.

[0049]

Specific examples Specific ofmica examples of micainclude includesynthetic syntheticmica mica(such (suchasasswelling swellingsynthetic syntheticmica), mica), white mica (muscovite), silk mica (sericite), phlogopite (phlogopite), black mica (biotite), white mica (muscovite), silk mica (sericite), phlogopite (phlogopite), black mica (biotite),

fluorine phlogopite (artificial mica), red mica, soda mica, vanadium mica, illite, tin mica, fluorine phlogopite (artificial mica), red mica, soda mica, vanadium mica, illite, tin mica,

paragonite, and paragonite, brittle mica. and brittle Further, specific mica. Further, specific examples of bentonite examples of bentonite include include montmorillonite. montmorillonite.

[0050]

Specific examples of kaolin include various kaolins such as kaolin, calcined kaolin, Specific examples of kaolin include various kaolins such as kaolin, calcined kaolin,

structured kaolin, and delaminated kaolin. structured kaolin, and delaminated kaolin.

[0051]

- 14 --

Among Among them, them, in in particular,the particular, the heat-sealable heat-sealable layer layer preferably preferably contains contains aa pigment pigment

having an having an aspect aspect ratio ratio of of 20 20 or or more, more, more preferably contains more preferably contains one one or or more moreselected selected from from mica, bentonite, kaolin, and talc, and still more preferably contains kaolin from the viewpoint mica, bentonite, kaolin, and talc, and still more preferably contains kaolin from the viewpoint

of heat sealing peel strength, blocking resistance, and economy. of heat sealing peel strength, blocking resistance, and economy.

[0052]

Whenthe When theheat-sealable heat-sealablelayer layercontains containsaa pigment, pigment,the the content content of of the the pigment is pigment is

preferably 11 part preferably part by by mass or more, mass or morepreferably more, more preferably33parts parts by by mass massorormore, more,still still more more

preferably 55 parts preferably parts by by mass or more, mass or and even more, and evenstill still more more preferably preferably 8 8 parts parts by by mass mass or or more more

relative to 100 parts by mass of the water-dispersible resin binder from the viewpoint of relative to 100 parts by mass of the water-dispersible resin binder from the viewpoint of

blocking resistance, whereas the content of the pigment is preferably 200 parts by mass or less, blocking resistance, whereas the content of the pigment is preferably 200 parts by mass or less,

more preferably 100 parts by mass or less, and still more preferably 30 parts by mass or less more preferably 100 parts by mass or less, and still more preferably 30 parts by mass or less

relative to 100 parts by mass of the water-dispersible resin binder, from the viewpoint of the relative to 100 parts by mass of the water-dispersible resin binder, from the viewpoint of the

heat sealing property. heat sealing property.

[0053]

Whenthe When theheat-sealable heat-sealablelayer layercontains containsaa pigment, pigment,the the content content of of the the pigment in the pigment in the heat-sealable layer heat-sealable layer is ispreferably preferably1% 1% by by mass or more, mass or morepreferably more, more preferably3%3% byby mass mass or or more, more,

still more still more preferably preferably 5% by mass 5% by massoror more, more,and andeven evenstill still more preferably 8% more preferably 8%bybymass mass or or more more

from the viewpoint of blocking resistance and recyclability, whereas the content of the from the viewpoint of blocking resistance and recyclability, whereas the content of the

pigmentinin the pigment the heat-sealable heat-sealable layer layer is ispreferably preferably70% 70% by by mass or less, mass or less, more preferably 30% more preferably by 30% by

mass or less, and still more preferably 20% by mass or less from the viewpoint of the heat mass mass or orless, less,and still and moremore still preferably 20% by20% preferably massbyormass less or from the from less viewpoint of the heat of the heat the viewpoint

sealing property. sealing property.

[0054]

(Other components) (Other components)

Theheat-sealable The heat-sealable layer layer may containother may contain othercomponents componentsin in additiontotothe addition thewater- water- dispersible resin dispersible resinbinder, binder,and andthe thelubricant and/or lubricant thethe and/or pigment pigmentifif necessary. necessary. Examples ofthe Examples of the other components other includesilane components include silanecoupling couplingagents; agents;defoaming defoaming agents; agents; viscositymodifiers; viscosity modifiers; leveling agents such as surfactants and alcohols; colorants such as coloring dyes. leveling agents such as surfactants and alcohols; colorants such as coloring dyes.

[0055]

The coating amount (basis weight) of the heat-sealable layer is not specifically limited. The coating amount (basis weight) of the heat-sealable layer is not specifically limited.

However,the However, thecoating coatingamount amount (basisweight) (basis weight) isispreferably g/m2orormore, preferably3 3g/m² more,more more preferably preferably 5 5 g/m2 or g/m² g/m2 or more, more, and andstill still more more preferably preferably 8 g/m²2 or 8 g/m or more fromthe more from theviewpoint viewpointofofobtaining obtainingaaa sufficient heat sealing property and from the viewpoint of obtaining a packaging bag that is sufficient heat sealing property and from the viewpoint of obtaining a packaging bag that is

difficult to tear and can be easily opened at the time of opening, and is preferably 30 g/m2 or difficult to tear and can be easily opened at the time of opening, and is preferably 30 g/m² or

less, more preferably 20 g/m² or 2less, and still more preferably 15 g/m² or less 2from the less, more preferably 20 g/m or less, and still more preferably 15 g/m or less from the viewpointof viewpoint of economy economy and and recyclability. recyclability.

- 15 --

[0056]

<Physical properties <Physical properties of of heat-sealable heat-sealable paper> paper>

(Tear index) (Tear index) Thelongitudinal The longitudinal and andtransverse transverse geometric geometricmean meanofof thetear the tearindex indexofofthe the heat-sealable heat-sealable 2 or more, and preferably 12 mN.m²/g or paper is paper is 10 10 mNm mN.m2/g mN.m²/g/g or more, and preferably 12 mNm2/g more or more fromfrom the viewpoint the viewpoint of of obtaining a packaging bag that is difficult to tear and can be easily opened at the time of obtaining a packaging bag that is difficult to tear and can be easily opened at the time of

opening, and the upper limit thereof is not specifically limited, but is preferably 30 mNm2/g opening, and the upper limit thereof is not specifically limited, but is preferably 30 mN.m2/g mN.m²/g

2 or less, and still more preferably 20 mN.m2/g 2 or less. or less, or less,more more preferably preferably 25 25 mNm mN.m2/g mN.m²/g/g or less, and still more preferably 20 mNm mN.m²/g/g or less. The tear index of the heat-sealable paper is a value obtained by dividing the tear The tear index of the heat-sealable paper is a value obtained by dividing the tear

strength measured strength accordingtotoJIS measured according JISPP8116:2000 8116:2000by by thethe basisweight. basis weight. A method A methodfor foradjusting adjustingthe thelongitudinal longitudinal and andtransverse transverse geometric geometricmean meanofof thetear the tear index of the heat-sealable paper to the above range is not specifically limited, but the index of the heat-sealable paper to the above range is not specifically limited, but the

longitudinal and longitudinal transverse geometric and transverse meanofofthe geometric mean thetear tear index index can can be be adjusted adjusted by by selecting selecting the the kind of pulp constituting the paper substrate or beating conditions (the beating degree, the kind of pulp constituting the paper substrate or beating conditions (the beating degree, the

pulp concentration at the time of beating, or the like). The tear index can be increased by pulp concentration at the time of beating, or the like). The tear index can be increased by

using, for using, for example, example, softwood pulp,preferably softwood pulp, preferably needle needleunbleached unbleachedkraft kraftpulp. pulp.In In addition,the addition, the tear index can be adjusted by setting an appropriate beating degree, and a high beating degree tear index can be adjusted by setting an appropriate beating degree, and a high beating degree

(a low (a low CSF) tendsto CSF) tends to decrease decrease the the tear tear index. Moreover, index. Moreover, beating beating at at a a highconcentration high concentration results in a branched or microfibrillar pulp, which makes it possible to increase the tearing results in a branched or microfibrillar pulp, which makes it possible to increase the tearing

resistance. Moreover, resistance. Moreover, use use of of extensiblepaper extensible papersubjected subjectedtotoClupak Clupak processing processing as as thethe paper paper

substrate can also absorb energy at the time of tearing when the extensible paper is elongated, substrate can also absorb energy at the time of tearing when the extensible paper is elongated,

which makes it possible to obtain a high tear index. which makes it possible to obtain a high tear index.

[0057]

The tear index of the heat-sealable paper in a longitudinal direction is preferably 8 The tear index of the heat-sealable paper in a longitudinal direction is preferably 8

mNm2/gorormore, mN.m2/g mN.m²/g more, and and more more preferably preferably 10 10 mNmor2/gmore mN.m2/g mN.m²/g or more fromviewpoint from the the viewpoint of obtaining of obtaining

a packaging bag that is difficult to tear and can be easily opened at the time of opening, and a packaging bag that is difficult to tear and can be easily opened at the time of opening, and

2 the upper limit thereof, which is not specifically limited, is preferably 30 mNm /g or less, the upper limit thereof, which is not specifically limited, is preferably 30 mN.m2/g mN.m²/g or less,

morepreferably more preferably24 mNm2/g 24mN.m2/g mN.m²/g or or less,and less, andstill still more preferably 18 more preferably mNm2/g 18mN.m2/g mN.m²/g or or less. less.

[0058]

The tear index of the heat-sealable paper in a transverse direction is preferably 10 The tear index of the heat-sealable paper in a transverse direction is preferably 10

mNm2/gorormore, mN.m2/g mN.m²/g more, more more preferably preferably 12 12 mNmor2/gmore, mN.m2/g mN.m²/g or more, and still and still moremore preferably preferably 14 14 mNm2/gorormore mN.m²/g more from from thethe viewpoint viewpoint of obtaining of obtaining a packaging a packaging bag bag thatthat is difficulttototear is difficult tear and and

can be easily opened at the time of opening, and the upper limit thereof, which is not can be easily opened at the time of opening, and the upper limit thereof, which is not

specifically limited, is preferably 32 mN.m²/g or 2less, more preferably 28 mN.m2/g mN.m²/g or less, 2 specifically limited, is preferably 32 mNm /g or less, more preferably 28 mNm /g or less, 2 or less. and still and still more more preferably preferably 24 24 mNm mN.m²/g/g or less.

16 --

[0059]

(Burst (Burst index) index)

2 The burst index of the heat-sealable paper is 3.0 kPam /g or more, and preferably 3.5 The burst index of the heat-sealable paper is 3.0 kPa.m2/g kPa.m²/g or more, and preferably 3.5

kPa.m2/g2 or more, from the viewpoint of obtaining a packaging bag that is difficult to tear and kPam /g or more, from the viewpoint of obtaining a packaging bag that is difficult to tear and kPa-m²/g

kPa.m²/g or2 less, more preferably 8.5 kPa.m2/g specifically limited, is preferably 10.0 kPam /g or less, more preferably 8.5 kPam /g or less, specifically limited, is preferably 10.0 kPa.m2/g 2 kPa.m²/g or less,

kPa.m²/g or2 less. and still more preferably 7.0 kPam /g or less. and still more preferably 7.0 kPa.m2/g

The burst index of the heat-sealable paper is a value obtained by dividing the bursting The burst index of the heat-sealable paper is a value obtained by dividing the bursting

strength measured strength accordingtotoJIS measured according JISPP8112:2008 8112:2008by by thethe basisweight. basis weight. A method for adjusting the burst index of the heat-sealable paper to the above range is A method for adjusting the burst index of the heat-sealable paper to the above range is

not specifically limited, but the burst index of the heat-sealable paper can be adjusted by not specifically limited, but the burst index of the heat-sealable paper can be adjusted by

selecting the kind of pulp constituting the paper substrate or the beating conditions, and the selecting the kind of pulp constituting the paper substrate or the beating conditions, and the

burst index burst index can can be be increased by using, increased by using, for for example, softwoodpulp, example, softwood pulp,preferably preferablyneedle needle unbleachedkraft unbleached kraft pulp. pulp. InInaddition, addition,the theburst burst index indexcan canbe beadjusted adjustedby bysetting setting an an appropriate appropriate beating degree, beating degree, and and aa high high beating beating degree (a low degree (a CSF)tends low CSF) tendstotodecrease decreasethe the burst burst index. index. Moreover, beating at a high concentration results in a branched or microfibrillar pulp, which Moreover, beating at a high concentration results in a branched or microfibrillar pulp, which

makes it possible to increase the bursting strength. makes it possible to increase the bursting strength.

Moreover,use Moreover, useofofextensible extensiblepaper papersubjected subjectedtoto Clupak Clupakprocessing processingasasthe thepaper paper substrate can also obtain a high burst index. In addition, addition of an internal paper substrate can also obtain a high burst index. In addition, addition of an internal paper

strengthening agent strengthening agent or the or the likelike to the to the paper paper substrate substrate canincrease can also also increase theindex. the burst burst index.

[0060]

(Heat sealingpeel (Heat sealing peel strength) strength)

In the In the heat-sealable heat-sealable paper paper of ofthe thepresent presentembodiment, fromthe embodiment, from the viewpoint viewpointofofobtaining obtaining a packaging bag that is difficult to tear and can be easily opened at the time of opening, the a packaging bag that is difficult to tear and can be easily opened at the time of opening, the

heat sealing heat sealing peel peel strength strength isis2.0 N/15 2.0 N/15mm or more, mm or preferably 3.0 more, preferably 3.0 N/15 mm N/15 mm or or more, more, more more

preferably 4.0 preferably 4.0 N/15 mmorormore, N/15 mm more, and and still more still morepreferably preferably4.5 4.5N/15 N/15mmmm or more, or more, and and is is preferably 10.0 preferably 10.0 N/15 mm N/15 mm or or less,more less, morepreferably preferably9.0 9.0N/15 N/15mmmm or less, or less, still more still morepreferably preferably 8.0 N/15 mm or less, even still more preferably 6.5 N/15 mm or less, and further still more 8.0 N/15 mm or less, even still more preferably 6.5 N/15 mm or less, and further still more

preferably 7.0 preferably 7.0 N/15 mmororless. N/15 mm less. Moreover, Moreover, the the heatheat sealing sealing peel peel strength strength is is preferably4.8 preferably 4.8 N/15mm N/15 mmor or more more from from the the viewpoint viewpoint of automatic of automatic packaging packaging formability. formability. Thestrength The peel peel strength of the heat-sealable layer is a peel strength when two heat-sealable layers are heat-sealed of the heat-sealable layer is a peel strength when two heat-sealable layers are heat-sealed

under the under the conditions conditions of of 150C, 0.2 MPa, 150°C, 0.2 MPa,and and1 1second, second,specifically, specifically, is is aa value value measured by measured by

the method the accordingtotoExamples, method according Examples, which which is is described described below. below.

The peel strength can be adjusted by selecting the glass transition temperature, the kind, The peel strength can be adjusted by selecting the glass transition temperature, the kind,

and the and the coating coating amount ofthe amount of the water-dispersible water-dispersible resin resin binder. Forexample, binder. For example, theresins the resinsmelt melt

- 17 --- 17

and heat-sealable and heat-sealable layers layers adhere adhere well well to to each each other other under under predetermined heat sealing predetermined heat sealing conditions by setting the glass transition temperature of the water-dispersible resin binder to conditions by setting the glass transition temperature of the water-dispersible resin binder to

100C 100°C oror less,SO less, soso thata adesired that desired peel peel strength strength canensured. can be be ensured.

[0061]

(Surface smoothness) (Surface smoothness) TheOken The Okensmoothness smoothness of of a surface a surface of of theheat-sealable the heat-sealablelayer layerofofthe the heat-sealable heat-sealable paper paper of the of the present present embodiment embodiment isispreferably preferably30 30seconds secondsorormore, more,more more preferably preferably 40 40 seconds seconds or or more, and more, andstill still more more preferably preferably 50 50 seconds or more, seconds or more, from fromthe theviewpoint viewpointofofimproving improving theheat the heat sealing peel strength, and the upper limit thereof, which is not specifically limited, is sealing peel strength, and the upper limit thereof, which is not specifically limited, is

preferably 500 seconds or less, more preferably 300 seconds or less, and still more preferably preferably 500 seconds or less, more preferably 300 seconds or less, and still more preferably

100 seconds 100 seconds or or less. less.

Theheat-sealable The heat-sealable layer layer may beprovided may be providedononW W side side (wire (wire side)ofofthe side) thepaper papersubstrate substrate or may be provided on F side (felt side), which is not specifically limited. Here, the W side or may be provided on F side (felt side), which is not specifically limited. Here, the W side

(wire side)isis aa side (wire side) sidethat thatisis in in contact contactwith with a wire a wire when when the paper the paper strip strip is is formed, formed, and its and its

opposite side is the F side (felt side). opposite side is the F side (felt side).

Further, the Oken smoothness of the surface opposite to the heat-sealable layer (the Further, the Oken smoothness of the surface opposite to the heat-sealable layer (the

other surface of the paper substrate, for example, in the case where the heat-sealable layer is other surface of the paper substrate, for example, in the case where the heat-sealable layer is

provided only on one surface of the paper substrate, and the paper substrate is exposed on the provided only on one surface of the paper substrate, and the paper substrate is exposed on the

other surface) other surface) is ispreferably preferably3 3seconds seconds or ormore, more, and and more preferably 55 seconds more preferably or more seconds or morefrom from the viewpoint of improving the printability, and the upper limit thereof, which is not the viewpoint of improving the printability, and the upper limit thereof, which is not

specifically limited, is preferably 1,000 seconds or less, more preferably 300 seconds or less, specifically limited, is preferably 1,000 seconds or less, more preferably 300 seconds or less,

and still more preferably 100 seconds or less. and still more preferably 100 seconds or less.

TheOken The Okensmoothness smoothness is is measured measured in accordance in accordance withwith JIS P8155:2010. JIS P8155:2010.

TheOken The Okensmoothness smoothness of of each each of of thethe surface surface of of theheat-sealable the heat-sealablelayer layerand andthe theopposite opposite surface of surface of the the heat-sealable heat-sealablepaper paper can can be be adjusted adjusted to tothe theaforementioned aforementioned range range by super by super

calendering or the like, which is described below. calendering or the like, which is described below.

[0062]

(Basis weight) (Basis weight)

From the viewpoint of obtaining a packaging bag that is difficult to tear and can be From the viewpoint of obtaining a packaging bag that is difficult to tear and can be

easily opened at the time of opening, the basis weight of the heat-sealable paper of the present easily opened at the time of opening, the basis weight of the heat-sealable paper of the present

2 more, more preferably 70 g/m2 or2 more, embodiment embodiment is is preferably5050g/m² preferably g/moror more, more preferably 70 g/m g/m² or more, stillmore still more preferably 80 preferably g/m2 or 80 g/m2 g/m² or more, more, and andeven evenstill still more preferably 85 more preferably g/m2or 85 g/m2 g/m² or more, more,and andisis preferably preferably 2 less, more preferably 150 g/m2 2 still more preferably 120 g/m² or less, and 2 200 g/m or less, more preferably 150 g/m or less, still more preferably 120 g/m or less, and 200 g/m² or g/m² or less,

2 even still more preferably 100 g/m or less. g/m² or less. even still more preferably 100 g/m2

Thebasis The basis weight weightof of the the heat-sealable heat-sealable paper paper is is measured accordingtoto JIS measured according JIS PP 8124:2011. 8124:2011.

- 18 --

[0063]

(Thickness) (Thickness)

easily opened at the time of opening, the thickness of the heat-sealable paper of the present easily opened at the time of opening, the thickness of the heat-sealable paper of the present

embodiment embodiment is is preferably µmm preferably6060um or or more, more, more more preferably preferably 80 um µm mmore, 80 or or more, stillstill moremore preferably 90 preferably morormore, 90 um µm more,and andeven evenstill still more morepreferably preferably100 µmm 100um or or more, more, andand is is preferably preferably

300 mororless, 300 um µm less, more morepreferably preferably200 m 200um µm or or less,and less, andstill still more preferably 150 more preferably mororless. 150 um µm less. Thethickness The thicknessof of the the heat-sealable heat-sealable paper paper is is measured accordingtoto JIS measured according JIS PP 8118:2014. 8118:2014.

[0064]

(Density) (Density)

easily opened at the time of opening, the density of the heat-sealable paper is preferably 0.50 easily opened at the time of opening, the density of the heat-sealable paper is preferably 0.50

g/cm3or g/cm³ or more, more,more morepreferably preferably0.60 0.60g/cm³ 3 more, and still more preferably 0.65 g/cm³ or g/cmoror more, and still more preferably 0.65 g/cm3 or 3 more preferably 0.90 g/cm³ or less, 3and still more more, and is preferably 1.0 g/cm or less, more preferably 0.90 g/cm or less, and still more more, and is preferably 1.0 g/cm³ or less,

preferably 0.80 preferably g/cm³3 or 0.80 g/cm or less. less. The Thedensity densityofofthe theheat-sealable heat-sealable paper paperis is calculated calculated from the from the

basis weight and the thickness of the heat-sealable paper that are obtained from the above basis weight and the thickness of the heat-sealable paper that are obtained from the above

measurementmethods. measurement methods.

[0065]

(Clark stiffness) (Clark stiffness)

The longitudinal and transverse geometric mean of the Clark stiffness of the heat- The longitudinal and transverse geometric mean of the Clark stiffness of the heat-

sealable paper is preferably 20 or more, more preferably 30 or more, still more preferably 35 sealable paper is preferably 20 or more, more preferably 30 or more, still more preferably 35

or more, or and even more, and evenstill still more more preferably preferably 40 40 or or more fromthe more from the viewpoint viewpointofofobtaining obtainingaa packaging bag that is difficult to tear and can be easily opened at the time of opening, and the packaging bag that is difficult to tear and can be easily opened at the time of opening, and the

longitudinal and transverse geometric mean of the Clark stiffness of the heat-sealable paper is longitudinal and transverse geometric mean of the Clark stiffness of the heat-sealable paper is

preferably 150 or less, more preferably 100 or less, still more preferably 85 or less, even still preferably 150 or less, more preferably 100 or less, still more preferably 85 or less, even still

more preferably 70 or less, or may be 60 or less, or may be 50 or less from the viewpoint of more preferably 70 or less, or may be 60 or less, or may be 50 or less from the viewpoint of

automatic packaging automatic packagingformability. formability. The longitudinal and transverse geometric mean of the Clark stiffness of the heat- The longitudinal and transverse geometric mean of the Clark stiffness of the heat-

sealable paper sealable paper is is obtained obtained by by determining determining aa geometric meanofofClark geometric mean Clarkstiffnesses stiffnesses in in the the longitudinal direction longitudinal direction and and in in the thetransverse transversedirection directionmeasured measured by by the the method of Example method of Example

according to according to JIS JIS P P 8143:2009. 8143:2009.

A method A methodfor foradjusting adjustingthe thelongitudinal longitudinal and andtransverse transverse geometric geometricmean meanofof theClark the Clark stiffness of the heat-sealable paper is not specifically limited but the longitudinal and stiffness of the heat-sealable paper is not specifically limited but the longitudinal and

transverse geometric mean of the Clark stiffness of the heat-sealable paper can be adjusted by transverse geometric mean of the Clark stiffness of the heat-sealable paper can be adjusted by

conditions such as the kind or the beating degree of pulp constituting the paper substrate, the conditions such as the kind or the beating degree of pulp constituting the paper substrate, the

- 19 --

basis weight, basis weight, calendering, calendering, and and Clupak processing.ForFor Clupak processing. example, example, whenwhen softwood softwood pulp pulp and and hardwood pulp are used as the pulp constituting the paper substrate, an increase in the content hardwood pulp are used as the pulp constituting the paper substrate, an increase in the content

of the of the hardwood pulptends hardwood pulp tendstotodecrease decreasethe the Clark Clarkstiffness. stiffness. InInaddition, addition, when whenthe thepulp pulp constituting the constituting the paper paper substrate substratehaving having an an increased increased beating beating degree degree and and a a low low CSF is used, CSF is used, the the Clark stiffness Clark stiffness tends tends to todecrease. Moreover,a adecrease decrease. Moreover, decreaseininthe thebasis basis weight weighttends tendsto to decrease decrease the Clark stiffness, and the paper substrate subjected to Clupak processing or calendaring the Clark stiffness, and the paper substrate subjected to Clupak processing or calendaring

tends to decrease the Clark stiffness. tends to decrease the Clark stiffness.

[0066]

The Clark stiffness of the heat-sealable paper in the longitudinal direction is preferably The Clark stiffness of the heat-sealable paper in the longitudinal direction is preferably

20 or 20 or more, morepreferably more, more preferably3030orormore, more,and andstill still more preferably 40 more preferably 40or or more morefrom fromthe the viewpoint of obtaining a packaging bag that is difficult to tear and can be easily opened at the viewpoint of obtaining a packaging bag that is difficult to tear and can be easily opened at the

time of opening, and is preferably 250 or less, more preferably 200 or less, still more time of opening, and is preferably 250 or less, more preferably 200 or less, still more

preferably 150 or less, even still more preferably 100 or less, further still more preferably 85 preferably 150 or less, even still more preferably 100 or less, further still more preferably 85

or less, much more preferably 80 or less, particularly preferably 75 or less, may be 70 or less, or less, much more preferably 80 or less, particularly preferably 75 or less, may be 70 or less,

maybebe6565ororless, may less, and and may be5555ororless may be less from fromthe the viewpoint viewpointofofautomatic automaticpackaging packaging formability. formability.

[0067]

The Clark stiffness of the heat-sealable paper in the transverse direction is preferably The Clark stiffness of the heat-sealable paper in the transverse direction is preferably

20 or 20 or more, morepreferably more, more preferably3030orormore, more,and andstill still more preferably 35 more preferably 35or or more morefrom fromthe the viewpoint of obtaining a packaging bag that is difficult to tear and can be easily opened at the viewpoint of obtaining a packaging bag that is difficult to tear and can be easily opened at the

or less, much more preferably 80 or less, particularly preferably 70 or less, may be 60 or less, or less, much more preferably 80 or less, particularly preferably 70 or less, may be 60 or less,

and may and maybebe5050ororless less from fromthe theviewpoint viewpointofofautomatic automaticpackaging packaging formability. formability.

[0068]

(Clark stiffness/basisweight) (Clark stiffness/basis weight) 2 A value (Clark stiffness/basis weight) (unit: m /g) obtained by dividing the A value (Clark stiffness/basis weight) (unit: m2/g) m²/g) obtained by dividing the

longitudinal and transverse geometric mean of the Clark stiffness of the heat-sealable paper longitudinal and transverse geometric mean of the Clark stiffness of the heat-sealable paper

by the basis weight (g/m²) of2 the heat-sealable paper is preferably 0.20 m²/g or more, 2 more by the basis weight (g/m ) of the heat-sealable paper is preferably 0.20 m /g or more, more 2 or more, and still more preferably 0.40 m²/g preferably 0.30 preferably 0.30 m /g or more, and still more preferably 0.40 m2/g or m²/g or more fromthe more from theviewpoint viewpoint of obtaining a packaging bag that is difficult to tear and can be easily opened at the time of of obtaining a packaging bag that is difficult to tear and can be easily opened at the time of

opening and from the viewpoint of formability (e.g., appearance of a bag), and is preferably opening and from the viewpoint of formability (e.g., appearance of a bag), and is preferably

1.20 m2/gororless, 1.20 m²/g less,more more preferably preferably 1.00 1.00 m2less, m²/g or /g or even less,still evenmore stillpreferably more preferably 0.90 m²/g 0.90 or m2/g or less, much more preferably 0.80 m²/g or 2less, particularly preferably 0.65 m²/g or less, 2 may be less, much more preferably 0.80 m /g or less, particularly preferably 0.65 m /g or less, may be

- 20 --

0.60 m2/g or 0.60 m²/g or less, less, and and may be 0.55 may be m2/gor 0.55 m²/g or less less from the viewpoint from the of automatic viewpoint of automaticpackaging packaging formability. formability.

In addition, In addition, when "the longitudinal when "the longitudinal and and transverse transverse geometric meanofofClark geometric mean Clark 2 is 1.00 m²/g or 2 less, the heat-sealable paper has an stiffness/basis weight (unit: m /g)" is 1.00 m /g or less, the heat-sealable paper has an m²/g)" stiffness/basis weight (unit: m2/g)"

appropriate softness appropriate softness and and the the heat-sealable heat-sealable paper paper can can follow follow deformation whenformed deformation when formed with with a a bag making bag makingmachine. machine. Therefore, Therefore, it thought it is is thought that that wrinkles wrinkles or or bad bad appearance appearance is prevented, is prevented,

and excellent and excellent automatic packagingformability automatic packaging formabilityisis achieved. achieved. Moreover, Moreover, whenwhen "the "the longitudinal and transverse geometric mean of Clark stiffness/basis weight (unit: m2/g)" is longitudinal and transverse geometric mean of Clark stiffness/basis weight (unit: m²/g)" is

2 or more, it is thought that firmness or robustness of the packaging bag is improved, 0.20 m /g or more, it is thought that firmness or robustness of the packaging bag is improved, 0.20 m²/g

and the and the packaging bagisis prevented packaging bag preventedfrom frombeing beingtorn. torn. In the specification, the phrase "excellent automatic packaging formability" means that In the specification, the phrase "excellent automatic packaging formability" means that

a bag a bag can be continuously can be continuouslyproduced producedwith withananautomatic automatic packaging packaging machine, machine, and and thatthat the the

appearanceofofthe appearance the obtained obtained bag bagisis good. good. Here, Here, thethe phrase phrase "a "a bag bag can can be be continuously continuously

produced"means produced" means thatwhen that when a packaging a packaging bag bag is formed is formed withwith an automatic an automatic packaging packaging machine, machine,

phenomena phenomena such such as as wrinkles, wrinkles, meandering, meandering, fracture fracture of of a packaging a packaging material, material, andand sticking sticking toto a a packagingmachine packaging machinedodo not not occur,ororthat occur, thateven evensuch suchphenomena phenomena occur, occur, it does it does notnot affect affect

continuousproduction continuous productionofofbags. bags.Furthermore, Furthermore, the the phrase phrase "the "the appearance appearance of aofbag a bag is good" is good"

meansthat means that bad badappearance appearancesuch suchasaswrinkles wrinklesonona abag, bag,seal sealdefect defect(misalignment (misalignmentofofa asealed sealed portion), or deformation is not found, or that even such bad appearance is found, it falls portion), or deformation is not found, or that even such bad appearance is found, it falls

within an within an acceptable acceptable range. range.

[0069]

[0069] 2 A value (Clark stiffness/basis weight) (unit: m /g) obtained by dividing the Clark A value (Clark stiffness/basis weight) (unit: m2/g) m²/g) obtained by dividing the Clark

stiffness of the heat-sealable paper in the longitudinal direction with the basis weight (g/m2) stiffness of the heat-sealable paper in the longitudinal direction with the basis weight (g/m²)

2 2 of the of the heat-sealable heat-sealable paper paper is ispreferably preferably0.20 0.20mm²/g /g orormore, more,more more preferably preferably 0.30 0.30 m m²/g/g or or more, more,

2 and still and still more more preferably preferably 0.40 0.40 m m²/g/g or or more fromthe more from the viewpoint viewpointofofobtaining obtainingaa packaging packagingbag bag that is difficult to tear and can be easily opened at the time of opening, and is preferably 2.40 that is difficult to tear and can be easily opened at the time of opening, and is preferably 2.40

2 or less, more preferably 2.00 m²/g or2 less, still more preferably 1.50 m²/g or less, 2 even m /g or less, more preferably 2.00 m /g or less, still more preferably 1.50 m /g or less, even m²/g

2 less, further still more preferably 0.90 m²/g or less, 2 still more preferably 1.00 m /g or less, further still more preferably 0.90 m /g or less, yet even still more preferably 1.00 m²/g or yet even

2 2 or less, may be 0.60 still more still more preferably preferably 0.80 0.80 m m²/g/g or or less, less,much much more preferably 0.70 more preferably 0.70 m /g or less, may be 0.60 m²/g

m2/g or m²/g or less, less, orormay may be be 0.55 0.55 m 2 or less from the viewpoint of automatic packaging /g or less from the viewpoint of automatic packaging m²/g

formability. formability.

[0070]

2 A value (Clark stiffness/basis weight) (unit: m /g) obtained by dividing the Clark A value (Clark stiffness/basis weight) (unit: m²/g) obtained by dividing the Clark

stiffness of the heat-sealable paper in the transverse direction with the basis weight (g/m2) of stiffness of the heat-sealable paper in the transverse direction with the basis weight (g/m²) of

2 2 or more, the heat-sealable the heat-sealable paper paper is ispreferably preferably0.20 0.20mm²/g /g orormore, more, more more preferably preferably 0.30 0.30 m /g or more, m²/g

- 21 --

2 and still and still more more preferably preferably 0.40 0.40 m m²/g/g or or more fromthe more from the viewpoint viewpointofofobtaining obtainingaa packaging packagingbag bag that is difficult to tear and can be easily opened at the time of opening, and is preferably 1.20 that is difficult to tear and can be easily opened at the time of opening, and is preferably 1.20

2 or less, more preferably 1.00 m²/g or2 less, still more preferably 0.90 m²/g or less, 2 m /g or less, more preferably 1.00 m /g or less, still more preferably 0.90 m /g or less, m²/g

2 less, and may be 0.60 m²/g or less 2 from the viewpoint of particularly preferably 0.80 m /g or less, and may be 0.60 m /g or less from the viewpoint of m²/g or particularly preferably 0.80 n2/g

automatic packaging automatic packagingformability. formability.

[0071]

(Piercing strength) (Piercing strength)

Thepiercing The piercing strength strength of of the the heat-sealable heat-sealable paper paper is ispreferably preferably10.0 10.0NNor ormore, more, more more

preferably 11.0 preferably 11.0 N or more, N or more, still still more more preferably preferably 12.0 12.0 N N or or more, more, or and and more, even even and stillmore still even still more more

preferably 12.5 N or more from the viewpoint of obtaining a packaging bag that is difficult to preferably 12.5 N or more from the viewpoint of obtaining a packaging bag that is difficult to

tear, and the upper limit thereof, which is not specifically limited, is preferably 30.0 N or less, tear, and the upper limit thereof, which is not specifically limited, is preferably 30.0 N or less,

more preferably 25.0 N or less, still more preferably 20.0 N or less, even still more preferably more preferably 25.0 N or less, still more preferably 20.0 N or less, even still more preferably

18.0 18.0 N or less, N or less,and and much morepreferably much more preferably17.0 17.0NNororless less from fromthe theviewpoint viewpointofofobtaining obtainingheat- heat- sealable paper having a desirable Clark stiffness and from the viewpoint of easy production. sealable paper having a desirable Clark stiffness and from the viewpoint of easy production.

Thepiercing The piercing strength strength of of the the heat-sealable heat-sealable paper paper is ismeasured measured according to JIS according to JIS Z Z

1717:2019. 1717:2019.

A method for adjusting the piercing strength of the heat-sealable paper to the above A method for adjusting the piercing strength of the heat-sealable paper to the above

range is not specifically limited but the piercing strength of the heat-sealable paper can be range is not specifically limited but the piercing strength of the heat-sealable paper can be

adjusted by selecting conditions such as the kind or beating degree of pulp constituting the adjusted by selecting conditions such as the kind or beating degree of pulp constituting the

paper substrate, paper substrate, basis basisweight, weight, and and Clupak processing. ForFor Clupak processing. example, example, when when at least at least oneone

selected from selected softwoodpulp from softwood pulpand andhardwood hardwood pulp pulp as the as the pulp pulp constituting constituting thepaper the papersubstrate substrateisis used, an increase in the content of softwood pulp tends to increase piercing strength. used, an increase in the content of softwood pulp tends to increase piercing strength. In In addition, when addition, the pulp when the pulp constituting constituting the the paper paper substrate substrate having having an an increased increased beating beating degree degree

and aa low and CSFisisused, low CSF used,the the piercing piercing strength strength tends tends to to decrease. Moreover, decrease. Moreover, anan increaseininthe increase the basis weight basis tends to weight tends to increase increase piercing piercing strength. Moreover,the strength. Moreover, thepaper papersubstrate substratesubjected subjectedtoto Clupakprocessing Clupak processingincreases increaseselongation elongationofofpaper paperand andcan canabsorb absorbananimpact impact due due to to piercing, piercing,

which tends to increase piercing strength. which tends to increase piercing strength.

[0072]

[Production method

[Production methodofofheat-sealable heat-sealablepaper] paper] Theproduction The productionmethod methodof of theheat-sealable the heat-sealablepaper paperofofthe theembodiment embodimentis is notnot

specifically limited. specifically Examplesthereof limited. Examples thereofinclude includea aproduction productionmethod method comprising comprising an an application step of applying at least one heat-sealable layer on at least one surface of a paper application step of applying at least one heat-sealable layer on at least one surface of a paper

substrate obtained substrate obtained by by a a method that comprises method that comprisesaacooking cookingstep stepofofcooking cookinga araw rawmaterial materialpulp, pulp, a beating a beating step step of of beating beating aadispersion dispersioncontaining containing20 20 mass% or more mass% or moreand and4545mass% mass% or less or less of of

the raw the material pulp raw material subjected to pulp subjected to cooking, cooking, and and aa papermaking stepofofmaking papermaking step making paper paper from from thethe

- 22 --

raw material raw raw material pulp material pulp subjected to pulp subjected subjected to to beating. Each beating. Each beating. Each stepof step step ofofthe theproduction the productionmethod production method method will will will be be be

described below. described below.

[0073]

(Cooking step) (Cooking step)

Thecooking The cookingstep stepisis step step of of cooking cooking aa raw raw material material pulp. pulp. TheThe kappa kappa number number of of the the raw material raw material pulp pulp is is preferably preferably 30 30 or or more and 60 more and 60 or or less less by by the the cooking step. Although cooking step. Althoughnotnot

specifically limited, raw material chips used as a material of the raw material pulp are specifically limited, raw material chips used as a material of the raw material pulp are

preferably treated preferably treated with with aa chemical chemical solution solution containing containing sodium hydroxide.As As sodium hydroxide. the the method method for for treatment with treatment with aa chemical solution containing chemical solution containing sodium sodiumhydroxide, hydroxide,a aknown known treatment treatment method method

using aa known using chemical known chemical solutioncan solution canbebeused. used.

[0074]

By setting the kappa number of the raw material pulp 30 or more and 60 or less, it is By setting the kappa number of the raw material pulp 30 or more and 60 or less, it is

possible to obtain heat-sealable paper that can form a packaging bag, which is difficult to tear possible to obtain heat-sealable paper that can form a packaging bag, which is difficult to tear

and can and can be be easily easily opened at the opened at the time time of of opening. From opening. From this this pointofofview, point view,the thekappa kappa number number

of raw material pulp is preferably 50 or less, more preferably 45 or less. of raw material pulp is preferably 50 or less, more preferably 45 or less.

[0075]

The raw material chips used as a material of the raw material pulp preferably contains The The raw rawmaterial materialchips usedused chips as a as material of the of a material rawthe material pulp preferably raw material contains pulp preferably contains

softwoodpulp softwood pulpasasaa main maincomponent. component. The "raw The "raw material material chipschips containing containing softwood softwood pulp pulp as a as a maincomponent" main component"hashas a content a content of of thesoftwood the softwood of of over over 50 50 mass%, mass%, preferably preferably a content a content of the of the

softwoodofof80 softwood 80mass% mass%or or more, more, more more preferably preferably 90 mass% 90 mass% or more, or more, further further preferably preferably 100 100 mass%,ininthe mass%, theraw rawmaterial materialchips. chips.

[0076]

Theraw The rawmaterial materialpulp pulpmay maynotnotbebebleached bleached or or may may be be bleached. bleached. Thematerial The raw raw material pulp is pulp is preferably preferably one one or or more selected from more selected the group from the consisting of group consisting of bleached kraft pulp bleached kraft pulp and and

unbleachedkraft unbleached kraft pulp, pulp, more morepreferably preferablyunbleached unbleachedkraft kraftpulp. pulp.

[0077]

(Beating step) (Beating step)

Thebeating The beatingstep step is is aa step stepof ofbeating beatinga adispersion dispersionpreferably containing preferably containing2020mass% or mass% or

moreand more and4545mass% mass%or or less less ofof theraw the rawmaterial materialpulp pulpsubjected subjectedtotocooking. cooking.The The beating beating

method is not specifically limited and preferably includes: dispersing, in water, the raw method is not specifically limited and preferably includes: dispersing, in water, the raw

material pulp material pulp subjected to cooking, subjected to cooking, producing producing aa dispersion dispersion having havingthe the above aboveraw rawmaterial material pulp concentration, pulp concentration, and subjecting the and subjecting the dispersion dispersion to to beating. Thebeating beating. The beatingmethod methodis is not not

specifically limited and can be performed, for example, using a beater such as a double disk specifically limited and can be performed, for example, using a beater such as a double disk

refiner, a single disk refiner, and a conical refiner. refiner, a single disk refiner, and a conical refiner.

[0078]

- 23 --

Beating the Beating the dispersion dispersion containing 20 mass% containing 20 mass% oror more more andand 45 45 mass% mass% or less or less of the of the rawraw

material pulp material pulp subjected subjected to to cooking allows aa paper cooking allows paper substrate substrate with with impact resistance and impact resistance and

workability and heat-sealable paper using the paper substrate to be obtained, as well as workability and heat-sealable paper using the paper substrate to be obtained, as well as

allowing excellent productivity. allowing excellent productivity.

[0079]

(Papermaking step) (Papermaking step)

Thepapermaking The papermaking step step isisa astep stepof of making makingpaper paperfrom from therawraw the material material pulp pulp subjected subjected

to beating. to Thepapermaking beating. The papermaking method method is not is not specifically specifically limited, limited, andand examples examples thereof thereof

include the include the acidic acidic papermaking method papermaking method in in which which papermaking papermaking is performed is performed at a at pHa of pHaround of around 4.5, the 4.5, the neutral neutralpapermaking methodininwhich papermaking method whichpapermaking papermaking is performed is performed at aatpHa pH of about of about 6 to6 to about 9, about 9, and and the the like. In the like. In the papermaking step,agents papermaking step, agentsfor for papermaking papermaking stepsuch step such asas pHpH

adjusters, defoamers, pitch control agents, and slime control agents can be appropriately adjusters, defoamers, pitch control agents, and slime control agents can be appropriately

added, as added, as required. The required. The paper paper making making machine machine is also is also not not specifically specifically limited,and limited, andexamples examples thereof include Fourdrinier, cylindrical, and inclined continuous paper machines or multilayer thereof thereofinclude includeFourdrinier, cylindrical, Fourdrinier, and inclined cylindrical, continuous and inclined paper machines continuous paperormachines multilayer or multilayer

paper machines paper machinesthat thatcombine combine these. these.

[0080]

Thepaper The papersubstrate substrate used used for for the the heat-sealable heat-sealable paper paper of of the theembodiment canbebe embodiment can

obtained by obtained by aa method methodincluding includingthe thecooking cookingstep, step,the thebeating beatingstep, step, and the papermaking and the step. papermaking step.

After the After the papermaking step,aa Clupak papermaking step, Clupakstep stepofof shrinking shrinkingthe the paper paper strip strip using using Clupak Clupak

equipmentmay equipment maybe be provided, provided, as as required.A known required. A known ClupakClupak equipment equipment can beThe can be used. used. The The productionmethod production methodofofthe thepaper papersubstrate substrateused usedfor for the the heat-sealable heat-sealable paper of the paper of the embodiment embodiment

is not is not limited limitedto tothe aforementioned the aforementioned method. method.

[0081]

Further, the Further, the production production method ofthe method of the heat-sealable heat-sealable paper paper in in the the embodiment may embodiment may

include a surface treatment step of treating the surface of the paper substrate with an agent. include a surface treatment step of treating the surface of the paper substrate with an agent.

Examplesofofthe Examples theagent agentused usedfor forthe the surface surface treatment treatment step step include include sizing sizing agents, agents, waterproofing waterproofing

agents, water agents, water retention retention agents, agents,thickeners, thickeners,lubricants, and lubricants, thethe and like. like.AAknown device can known device can be be used for the surface treatment step. used for the surface treatment step.

[0082]

Theproduction The productionmethod methodof of theheat-sealable the heat-sealablepaper paperofofthe theembodiment embodiment comprises comprises an an application step of applying the heat-sealable layer on at least one surface of the paper application step of applying the heat-sealable layer on at least one surface of the paper

substrate obtained substrate obtained as as described described above. The above. The heat-sealable heat-sealable layercoating layer coatingliquid liquid(heat-sealable (heat-sealable layer coating layer coating material) material) may be applied may be applied twice twice or or more. more.

[0083]

- 24 --

In the case of forming multiple heat-sealable layers on the paper substrate, the In the case of forming multiple heat-sealable layers on the paper substrate, the

aforementionedmethod aforementioned methodof of sequentiallyforming sequentially forming thethe heat-sealable heat-sealable layersisispreferable, layers preferable, but but there is there isno no limitation limitationtoto this, andand this, a simultaneous multilayer a simultaneous coating multilayer method coating methodmay may be be employed. employed.

Thesimultaneous The simultaneousmultilayer multilayercoating coatingmethod methodis is a a method method of of discharging discharging multiple multiple types types of of

coating liquids separately from slit-shaped nozzles to form a liquid laminate and applying the coating liquids separately from slit-shaped nozzles to form a liquid laminate and applying the

laminate to the paper substrate to form multiple heat-sealable layers simultaneously. laminate to the paper substrate to form multiple heat-sealable layers simultaneously.

[0084]

The application equipment for applying the heat-sealable layer coating liquid to the The application equipment for applying the heat-sealable layer coating liquid to the

paper substrate paper substrate is isnot notspecifically specificallylimited, andand limited, known knownequipment maybebeused. equipment may used.Examples Examples of of the application equipment include blade coaters, bar coaters, air knife coaters, slit die coaters, the application equipment include blade coaters, bar coaters, air knife coaters, slit die coaters,

gravure coaters, micro gravure coaters, roll coaters, size presses, gate roll coaters, Sym-sizers, gravure coaters, micro gravure coaters, roll coaters, size presses, gate roll coaters, Sym-sizers,

and the like. and the like.

[0085]

The drying equipment for drying the heat-sealable layer is not specifically limited, and The drying equipment for drying the heat-sealable layer is not specifically limited, and

knownequipment known equipment cancan be be used. used. Examples Examples of theof the drying drying equipment equipment includeinclude hot airhot air dryers, dryers,

infrared dryers, gas burners, hot plates, and the like. Further, the drying temperature may be be infrared dryers, gas burners, hot plates, and the like. Further, the drying temperature may be

appropriately set in consideration of the drying time. appropriately set in consideration of the drying time.

[0086]

The solvent for the heat-sealable layer coating liquid is not specifically limited, and The solvent for the heat-sealable layer coating liquid is not specifically limited, and

water or an organic solvent such as ethanol, isopropyl alcohol, methyl ethyl ketone, and water or an organic solvent such as ethanol, isopropyl alcohol, methyl ethyl ketone, and

toluene can toluene can be be used. used. Among Among these, these, water water is preferable is preferable as as a dispersion a dispersion medium medium for for the the heat- heat-

sealable layer coating liquid, since there is no problem of volatile organic solvents. That is, sealable layer coating liquid, since there is no problem of volatile organic solvents. That is,

the heat-sealable layer coating liquid is preferably an aqueous composition for heat-sealable the heat-sealable layer coating liquid is preferably an aqueous composition for heat-sealable

layers. layers.

[0087]

The solid content (solid content concentration) of the heat-sealable layer coating liquid The solid content (solid content concentration) of the heat-sealable layer coating liquid

is not specifically limited and may be appropriately selected from the viewpoint of the coating is not specifically limited and may be appropriately selected from the viewpoint of the coating

property and property and ease ease of of drying drying but but is is preferably preferably 10% bymass 10% by massorormore, more,more more preferably preferably 20% 20% by by massor mass or more, more,and andstill still more preferably 30% more preferably 30% bybymass massoror more, more, and and is is preferably80% preferably 80%by by mass mass

or less, or less,more more preferably preferably 60% bymass 60% by massororless, less, still still more more preferably preferably 50% by mass 50% by massororless, less, and and

even still even still more more preferably preferably 40% bymass 40% by massororless. less.

[0088]

The preferable range of the coating amount (after drying) of the heat-sealable layer is The preferable range of the coating amount (after drying) of the heat-sealable layer is

as described as described above. The above. The heat-sealable heat-sealable layermaymay layer be be oneone layer layer or or maymay be two be two or more or more layers. layers.

- 25 --

Whenthe When thenumber numberof of thethe heat-sealablelayer heat-sealable layerisistwo twoorormore, more,the theaforementioned aforementioned coating coating

amountisis the amount the total total coating coating amount. amount.

[0089]

After the heat-sealable layer is applied and dried, super calendering is preferably After the heat-sealable layer is applied and dried, super calendering is preferably

performed.Here, performed. Here, thethe super super calendering calendering is is provided provided independently independently fromfrom the the papermaking papermaking

and is generally to pass the paper to be processed between metal rolls or between a metal roll and is generally to pass the paper to be processed between metal rolls or between a metal roll

and an elastic roll, heat it, apply a pressure thereto, and the like. Super calendering may be and an elastic roll, heat it, apply a pressure thereto, and the like. Super calendering may be

performed in one stage or in multiple stages, and there is no specific limitation. performed in one stage or in multiple stages, and there is no specific limitation.

Preferably, super Preferably, super calendering improvesthe calendering improves thesmoothness smoothnessofof thesurface the surfaceofofthe theheat- heat- sealable layer, which results in improvement of the heat sealing peel strength (decrease in the sealable layer, which results in improvement of the heat sealing peel strength (decrease in the

minimum minimum substrate substrate destructiontemperature) destruction temperature) and and a decrease a decrease in in theClark the Clarkstiffness. stiffness. Further, it is preferable since the smoothness of the surface opposite to the heat- Further, it is preferable since the smoothness of the surface opposite to the heat-

sealable layer (the other surface of the paper substrate, for example, in the case where the sealable layer (the other surface of the paper substrate, for example, in the case where the

heat-sealable layer is provided only on one surface of the paper substrate, and the paper heat-sealable layer is provided only on one surface of the paper substrate, and the paper

substrate is exposed on the other surface) is improved, as a result of which the printability is is substrate is exposed on the other surface) is improved, as a result of which the printability is

improved. improved.

Further, since the density of the heat-sealable paper tends to increase by super Further, since the density of the heat-sealable paper tends to increase by super

calendering, and calendering, the surface and the surface smoothness is improved, smoothness is improved,asasdescribed describedabove, above,super supercalendering calenderingisis preferable because preferable delivering the because delivering the heat-sealable heat-sealable paper paper in in the thepacking packing machine duringbag machine during bag makingbecomes making becomes good, good, thereby thereby improving improving processability. processability.

Thelinear The linear pressure pressure in in super super calendering calendering is is preferably preferably10 10 kg/cm kg/cm or or more, more more, more

preferably 30 preferably kg/cmorormore, 30 kg/cm more,further further preferably preferably 50 50 kg/cm kg/cmorormore, more,and andisispreferably preferably1000 1000 kg/cm or less, more preferably 500 kg/cm or less, further preferably 200 kg/cm or less. kg/cm or less, more preferably 500 kg/cm or less, further preferably 200 kg/cm or less.

However,the However, thelinear linear pressure pressure may maybebeappropriately appropriatelychanged changed according according to to thethe desired desired

smoothnessand smoothness anddensity. density. Further, in the case where heating is performed in super calendering, the heating Further, in the case where heating is performed in super calendering, the heating

temperatureis temperature is not not specifically specificallylimited limitedbut butisis preferably 20C preferably 20°Coror more, more,more more preferably preferably 30C 30°C

or more, or further preferably more, further preferably 35C or more, 35°C or andis more, and is preferably preferably 80C or less, 80°C or less, more preferably more preferably

70C or less, further preferably 60C or less, for preventing deterioration of the paper 70°C or less, further preferably 60°C or less, for preventing deterioration of the paper

substrate and the heat-sealable layer due to heat and sticking of the heat-sealable layer while substrate and the heat-sealable layer due to heat and sticking of the heat-sealable layer while

enhancing the effect of treatment. enhancing the effect of treatment.

[0090]

Theheat-sealable The heat-sealable paper paper according accordingtoto the the present present embodiment embodiment cancan be be favorably favorably used used as as a packaging a bagfor packaging bag for foods, foods, household householdgoods, goods,books, books,commodities commodities (soaps, (soaps, cleaning cleaning agents, agents, andand

- 26 --

diapers), and diapers), and the the like. Accordingly,the like. Accordingly, thepresent present invention invention also also provides provides aa packaging packagingbag bag using the heat-sealable paper. using the heat-sealable paper.

Examples Examples

[0091]

Hereinafter, examples will be mentioned in order to specifically describe this invention, Hereinafter, examples will be mentioned in order to specifically describe this invention,

but this but this invention invention is isnot notlimited toto limited these examples. these examples. Unless otherwisespecified, Unless otherwise specified, the the following following

operations were performed operations were performedunder underthetheconditions conditionsofof23°C 23C and and a relativehumidity a relative humidityofof50%RH. 50%RH. In the In the following following examples andcomparative examples and comparative examples, examples, "parts" "parts" andand "%""%" respectively respectively refer refer to to

"parts by "parts by mass" and "mass%", mass" and "mass%", unlessotherwise unless otherwise specified. specified.

[0092]

[Example1]1]

[Example

<Preparation <Preparation of <Preparation ofof heat-sealable heat-sealable layer layer heat-sealable coating coating layer material> material> coating material>

98 parts 98 parts of of an an aqueous dispersion of aqueous dispersion of aa styrene/butadiene styrene/butadiene copolymer (Nipollatex copolymer (Nipol latex LX407S12, LX407S12, available available from from Zeon Zeon Corporation, Corporation, solid solid content content 46%, 46%, glass glass transition transition temperature: temperature:

18C (catalog 18°C (catalog value)) value)) (in (in terms terms of solid of solid content) content) and 2 and parts2 of parts of a paraffin a paraffin wax emulsion wax emulsion

(Hidorin L-700, (Hidorin L-700,available available from fromChukyo Chukyo Yushi Yushi Co., Co., Ltd., Ltd., solidcontent solid content30%) 30%)(in(in terms terms of of solid solid

content) were content) mixed,and were mixed, andwater waterwas wasadded added thereto thereto toto a asolid solidcontent contentconcentration concentrationofof33%, 33%, followed by stirring, to prepare a heat-sealable layer coating material (concentration 33%). followed by stirring, to prepare a heat-sealable layer coating material (concentration 33%).

Thestyrene/butadiene The styrene/butadienecopolymer copolymerhadhad a solubilityininwater a solubility wateratat 25°C 25Cofof1010g/L g/Lororless. less.

[0093]

<Production ofheat-sealable <Production of heat-sealable paper> paper> Theobtained The obtainedheat-sealable heat-sealablelayer layer coating coating material material was usedto was used to form formaa heat-sealable heat-sealable layer with an air knife coater on the W side of extensible paper having a basis weight of 82.9 layer with an air knife coater on the W side of extensible paper having a basis weight of 82.9

g/m2, aa thickness g/m², thickness of 123 m, of 123 um, andaa density µm, and density of of 0.67 g/cm³3 (( available 0.67 g/cm available from from Oji Oji Materia Co., Materia Co.,

Ltd., needle Ltd., needle unbleached kraft pulp: unbleached kraft pulp: 100% bymass, 100% by mass,Canadian Canadian standard standard freeness: freeness: 677677 mL,mL,

Clupakprocessing Clupak processingwas wasdone, done,smoothness smoothness F side: F side: 4 seconds, 4 seconds, W side: W side: 7 seconds) 7 seconds) SO so that so that thethe

2 heat-sealable coating amount of the heat-sealable layer after drying was 10 g/m , then, the heat-sealable coating amount of the heat-sealable layer after drying was 10 g/m², then, the

layer coating material was dried with a dryer at 130 to 160C, finally, a chilled roll was in layer coating material was dried with a dryer at 130 to 160°C, finally, a chilled roll was in

contact with the coated surface and a cotton roll was in contact with the non-coated surface so contact with the coated surface and a cotton roll was in contact with the non-coated surface SO so

as to achieve a linear load of 90 kg/cm, followed by heating the rolls to 40C and one-stage as to achieve a linear load of 90 kg/cm, followed by heating the rolls to 40°C and one-stage

super calendering, super calendering, to to thereby thereby obtain obtain heat-sealable heat-sealable paper paper (smoothness (smoothness FF side: side: 88 seconds, seconds, W W

side: 64 side: 64 seconds). Supercalendering seconds). Super calendering increased increased thesmoothness the smoothness and and improved improved printability printability

comparedtotopaper compared paperbefore beforecoating. coating.

[0094]

- 27 --

[Example

[Example 2]2]

A heat-sealable A heat-sealable layer layer was formedand was formed andsuper supercalendering calenderingwas was performed performed in the in the same same

mannerasasinin Example manner Example 1 1 except except thatthe that theextensible extensiblepaper paperwas waschanged changedto to extensiblepaper extensible paper having aa basis having basis weight of 78.3 weight of g/m2, aa thickness 78.3 g/m², thickness of 126 m, of 126 um, andaa density µm, and density of of 0.62 g/cm³3 0.62 g/cm

(available (available from from Oji Oji Materia Co., Ltd., Materia Co., Ltd., needle needle unbleached kraft pulp: unbleached kraft pulp: 100% bymass, 100% by mass,Canadian Canadian standard freeness: standard freeness: 563 563 mL, smoothness mL, smoothness F side:1212seconds, F side: seconds,W W side: side: 2929 seconds) seconds) andand thethe

coating amount of a heat-sealable layer after drying was set to 12 g/m², thereby2 to obtain heat- coating amount of a heat-sealable layer after drying was set to 12 g/m , thereby to obtain heat- sealable paper sealable paper (smoothness (smoothness FFside: side: 15 15 seconds, seconds,WWside: side:6161seconds). seconds).

[0095]

[Example

[Example 3]3]

mannerasasinin Example manner Example 1 1 except except thatthe that theextensible extensiblepaper paperwas waschanged changedto to heavy-duty heavy-duty

packagingpaper packaging paperhaving havinga abasis basisweight weightofof79.2 g/m2,aathickness 79.2g/m², thicknessof of 132 m,and 132um, µm, anda adensity densityofof 0.60 g/cm3 (available 0.60 g/cm³ (available from Oji Materia from Oji MateriaCo., Co., Ltd., Ltd., needle needle unbleached kraft pulp: unbleached kraft pulp: 100% 100%byby mass, Canadian mass, Canadianstandard standardfreeness: freeness:578 578mL, mL, smoothness smoothness F side: F side: 3 seconds, 3 seconds, W side: W side: 2 seconds, 2 seconds,

Clupakprocessing Clupak processingwas wasnot notperformed) performed) andand thethe coating coating amount amount of aofheat-sealable a heat-sealable layer layer after after 2 thereby to obtain heat-sealable paper (smoothness F side: 25 drying was drying wasset set to to 10 10 g/m g/m²,, thereby to obtain heat-sealable paper (smoothness F side: 25 seconds, WWside: seconds, side: 65 65seconds). seconds).

[0096]

[Example4]4]

[Example

Ninety eight Ninety eight parts parts of of an an aqueous dispersion of aqueous dispersion of aa commercially available ethylene- commercially available ethylene- acrylic acid copolymer (glass transition temperature: 45C) (in terms of solid content) and 2 acrylic acid copolymer (glass transition temperature: 45°) 45°C)(in (interms termsof ofsolid solidcontent) content)and and22

parts of parts of an an aqueous dispersion of aqueous dispersion of aa commercially available carnauba commercially available carnaubawax wax(Michem (Michem LubeLube

160RPH, availablefrom 160RPH, available fromMichelman, Michelman, solid solid content content concentration: concentration: 25%25% by mass) by mass) (in terms (in terms of of

solid content) were mixed, and water was added thereto with stirring so that the solid content solid content) were mixed, and water was added thereto with stirring SO so that the solid content

concentration was concentration was35%, 35%,totothereby therebyprepare preparea aheat-sealable heat-sealablelayer layer coating coating material material (concentration: 35%). (concentration: A heat-sealable 35%). A heat-sealable layer layer was was formed formed and and super super calendering calendering was was performedininthe performed the same samemanner manneras as inin Example Example 2 except 2 except that that thethe obtained obtained heat-sealable heat-sealable layer layer

coating material coating material was used, to was used, to thereby thereby obtain obtain heat-sealable heat-sealable paper paper (smoothness (smoothness FFside: side: 88 seconds, WWside: seconds, side: 82 82seconds). seconds).TheThe ethylene-acrylic ethylene-acrylic acid acid copolymer copolymer had had a solubility a solubility to to water water

of 10 g/L or less at 25C. of 10 g/L or less at 25°C.

[0097]

[Example

[Example 5]5]

mannerasasinin Example manner Example 1 1 except except that2 2parts that partsof of aa polyethylene polyethylenewax waxemulsion emulsion (Aquacer (Aquacer 531,531,

- 28 --

available from available BYK,solid from BYK, solidcontent contentconcentration: concentration:45% 45%by by mass) mass) (in(in terms terms of of solidcontent) solid content) was added instead of 2 parts of the paraffin wax emulsion (in terms of solid content), to was added instead of 2 parts of the paraffin wax emulsion (in terms of solid content), to

prepare a heat-sealable layer coating material, to thereby obtain heat-sealable paper prepare a heat-sealable layer coating material, to thereby obtain heat-sealable paper

(smoothnessF Fside: (smoothness side: 88 seconds, seconds, WWside: side:4242seconds) seconds)

[0098]

[Example

[Example 6]6]

Heat-sealable paper Heat-sealable paper (smoothness (smoothnessF Fside: side:1212seconds, seconds,W W side:4040seconds) side: seconds) was was obtained obtained

in the in the same mannerasasinin Example same manner Example 2 2 except except thatsuper that supercalendering calenderingwas was notnot performed. performed.

[0099]

[Example

[Example 7]7]

mannerasasinin Example manner Example 1 1 except except thatthe that theparaffin paraffin wax waxemulsion emulsion was was notnot added, added, to to thereby thereby

obtain heat-sealable obtain heat-sealable paper paper (smoothness (smoothness FFside: side: 88 seconds, seconds, WWside: side:60 60seconds). seconds).

[0100]

[Example

[Example 8]8]

Heat-sealable paper Heat-sealable paper (smoothness (smoothnessF Fside: side:88seconds, seconds,WW side:1212seconds) side: seconds)was was obtained obtained

in the in the same mannerasasinin Example same manner Example 1 1 except except that1010parts that partsofofan anaqueous aqueousdispersion dispersionofofkaolin kaolin (average particlesize: (average particle m, size:8 8um, µm, aspect aspect ratio: ratio: 80100) 80 to to 100) havinghaving a solidacontent solid content concentration concentration of of 50% (in terms of solid content), 88 parts of an aqueous dispersion of a styrene/butadiene 50% (in terms of solid content), 88 parts of an aqueous dispersion of a styrene/butadiene

copolymer(available copolymer (availablefrom fromZeon Zeon Corporation, Corporation, Nipol Nipol latex latex LX407S12, LX407S12, solidsolid content content

concentration: 46%, glass transition temperature: 18C (catalog value)) (in terms of solid concentration: 46%, glass transition temperature: 18°C (catalog value)) (in terms of solid

content), and content), and 2 2 parts parts of ofa aparaffin paraffinwax waxemulsion emulsion (available (available from from Chukyo YushiCo., Chukyo Yushi Co.,Ltd., Ltd., Hidorin L-700, Hidorin L-700,solid solid content content concentration: concentration: 30%) 30%)(in (interms termsofof solid solid content) content) were used to were used to prepare a heat-sealable layer coating material. prepare a heat-sealable layer coating material.

[0101]

[Example

[Example 9]9]

mannerasasinin Example manner Example 1 1 except except that2 2parts that partsof of aa carnauba carnaubawax waxemulsion emulsion (Michem (Michem Lube Lube

solid content) was added instead of 2 parts of the paraffin wax emulsion (in terms of solid solid content) was added instead of 2 parts of the paraffin wax emulsion (in terms of solid

content), to prepare a heat-sealable layer coating material, to thereby obtain heat-sealable content), to prepare a heat-sealable layer coating material, to thereby obtain heat-sealable

paper (smoothness paper (smoothnessF Fside: side:88seconds, seconds,WWside: side:6464seconds). seconds).

[0102]

[Example

[Example 10]

[Example10] 10]

- 29 --

mannerasasinin Example manner Example 2 2 except except that2 2parts that partsof of aa polyethylene polyethylenewax waxemulsion emulsion (Aquacer (Aquacer 531,531,

available from available BYK,solid from BYK, solidcontent contentconcentration: concentration:45% 45%by by mass) mass) (in(in terms terms of of solidcontent) solid content) was added instead of 2 parts of the paraffin wax emulsion (in terms of solid content) to was added instead of 2 parts of the paraffin wax emulsion (in terms of solid content) to

(smoothness (smoothness F Fside: side: 15 15seconds, seconds,WWside: side:4242seconds). seconds).

[0103]

[Example 11]

mannerasasinin Example manner Example 1 1 except except thatthe that theextensible extensiblepaper paperwas waschanged changedto to extensiblepaper extensible paper having aa basis having basis weight of 100.0 weight of g/m2, aa thickness 100.0 g/m², thickness of of 149 m, 149 um, andaadensity µm, and density of of 0.67 g/cm3 0.67 g/cm³ (available (available from from Oji Oji Materia Co., Ltd., Materia Co., Ltd., needle needle unbleached kraft pulp: unbleached kraft pulp: 100% bymass, 100% by mass,Canadian Canadian standard freeness: standard freeness: 677 mL,Clupak 677 mL, Clupakprocessing processing was was performed, performed, smoothness smoothness F side: F side: 7 seconds, 7 seconds,

Wside: W side: 18 18seconds), seconds),to to thereby thereby obtain obtain heat-sealable heat-sealable paper (smoothnessF Fside: paper (smoothness side: 88 seconds, seconds, WW side: 57 seconds). side: 57 seconds).

[0104]

[Example

[Example 12]

[Example12] 12]

Heat-sealable paper Heat-sealable paper (smoothness (smoothnessF Fside: side:1515seconds, seconds,W W side:2424seconds) side: seconds) was was obtained obtained

in the in the same mannerasasinin Example same manner Example 2 2 except except that1010parts that partsofofan anaqueous aqueousdispersion dispersionofofkaolin kaolin (average particlesize: (average particle m, size:8 8um, µm, aspect aspect ratio: ratio: 80100) 80 to to 100) havinghaving a solidacontent solid content concentration concentration of of 50% (in terms of solid content), 88 parts of an aqueous dispersion of a styrene/butadiene 50% (in terms of solid content), 88 parts of an aqueous dispersion of a styrene/butadiene

content), and content), and 2 2 parts parts of ofa aparaffin paraffinwax waxemulsion emulsion (available (available from from Chukyo YushiCo., Chukyo Yushi Co.,Ltd., Ltd., Hidorin L-700, Hidorin L-700,solid solid content content concentration: concentration: 30%) 30%)(in (interms termsofofsolid solid content) content) were used to were used to prepare a heat-sealable layer coating material. prepare a heat-sealable layer coating material.

[0105]

[Example

[Example 13]

[Example13] 13]

mannerasasinin Example manner Example 2 2 except except that2 2parts that partsof of aa carnauba carnaubawax waxemulsion emulsion (Michem (Michem Lube Lube

paper (smoothness paper (smoothnessF Fside: side:15 15seconds, seconds,WW side:6262seconds). side: seconds).

[0106]

- 30 --

[Comparative Example

[Comparative Example 1] 1]

mannerasasinin Example manner Example 1 1 except except thatthe that theextensible extensiblepaper paperwas waschanged changed to to unbleached unbleached light- light-

duty packaging duty packagingpaper paperhaving havinga abasis basisweight weightofof80.5 g/m2,a athickness 80.5g/m², thicknessofof 114 m,and 114um, µm, anda a 3 density of 0.71 g/cm (available from Oji Materia Co., Ltd., needle unbleached kraft pulp / density of 0.71 g/cm³ (available from Oji Materia Co., Ltd., needle unbleached kraft pulp /

leaf bleached leaf bleached kraft kraft pulp pulp == 80/20 80/20 (mass ratio), Canadian (mass ratio), Canadian standard standard freeness: freeness: 478 478 mL, mL,

smoothnessF Fside: smoothness side:17 17seconds, seconds,WW side:1616seconds), side: seconds),totothereby therebyobtain obtainheat-sealable heat-sealablepaper paper (smoothness (smoothness F Fside: side: 89 89seconds, seconds,WWside: side:219 219seconds). seconds).

[0107]

[Comparative Example

[Comparative Example 2] 2]

Unbleachedlight-duty Unbleached light-dutypackaging packaging paper paper having having a basis a basis weight weight of of 70.0 70.0 g/ma2, thickness g/m², a thickness of 100 of m,and µm, 100 um, andaadensity densityof of 0.70 g/cm3(available 0.70 g/cm³ (available from fromOji Oji Materia MateriaCo., Co.,Ltd., Ltd., needle needle unbleachedkraft unbleached kraft pulp/leaf pulp/leaf bleached kraft pulp bleached kraft pulp = = 80/20 (massratio), 80/20 (mass ratio), Canadian standard Canadian standard

freeness: 478 freeness: 478 mL, smoothness mL, smoothness F F side:1616seconds, side: seconds,W W side: side: 1414 seconds) seconds) waswas subjected subjected to to melt melt

extrusion lamination extrusion lamination SO so that so that the the thickness thickness of ofpolyethylene polyethylene was was 20 m, 20 um, to thereby µm, to thereby form form 2 polyethylenelaminated polyethylene laminatedpaper paperhaving havinga abasis basisweight weightofof89.2 89.2g/m2 g/m(smoothness g/m² (smoothness F side: F side: 16 16

seconds, WWside: seconds, side: 140 140seconds). seconds).

[0108]

[Comparative Example

[Comparative Example 3] 3]

mannerasasinin Example manner Example 3 3 except except thatananaqueous that aqueous dispersion dispersion of of anan ethylene/vinylacetate ethylene/vinyl acetate copolymer (available copolymer (available from fromSumika SumikaChemtex Chemtex Company, Company, Limited, Limited, SUMIKAFLEX 470HQ, SUMIKAFLEX 470HQ,

solid content: 55%, glass transition temperature: 0C (catalog value)) was used instead of the solid content: 55%, glass transition temperature: 0°C (catalog value)) was used instead of the

aqueousdispersion aqueous dispersionof of the the styrene/butadiene styrene/butadiene copolymer copolymerasasthe theheat-sealable heat-sealablelayer layer coating coating material, and material, and the the paraffin paraffinwax wax emulsion wasnot emulsion was notused, used,to to thereby thereby obtain obtain heat-sealable heat-sealable paper paper

(smoothnessF Fside: (smoothness side: 25 25seconds, seconds,WWside: side:5656seconds). seconds).

[0109]

[Comparative Example

[Comparative Example 4] 4]

mannerasasinin Example manner Example 1 1 except except thatthe that theextensible extensiblepaper paperwas waschanged changedto to one-side one-side glazed glazed kraft kraft

paper having paper havingaa basis basis weight weight of of 78.2 g/m2, aa thickness 78.2 g/m², thickness of 100 m, of 100 um, andaa density µm, and density of of 0.78 g/cm3 0.78 g/cm³ (available from Oji Materia Co., Ltd., needle bleached kraft pulp/leaf bleached kraft pulp = (available from Oji Materia Co., Ltd., needle bleached kraft pulp/leaf bleached kraft pulp =

35/65 (mass 35/65 (massratio), ratio), Canadian standardfreeness: Canadian standard freeness: 578 578 mL, mL,smoothness smoothness F side:120120 F side: seconds, seconds, W W side: 18 side: 18 seconds), seconds), to to thereby thereby obtain obtainheat-sealable heat-sealablepaper paper(smoothness F side: (smoothness F side: 300 300 seconds, seconds, W W

side: 291 seconds). side: 291 seconds).

- 31 --

[0110]

[Comparative Example

[Comparative Example 5] 5]

mannerasasinin Example manner Example 1 1 except except thatthe that theextensible extensiblepaper paperwas waschanged changedto to one-side one-side bleached bleached

kraft paper having a basis weight of 50.7 g/m , a thickness of 61 m, and a density of 0.83 2 kraft paper having a basis weight of 50.7 g/m², a thickness of 61 um, µm, and a density of 0.83

g/cm3 (available g/cm³ (available from from Oji Oji F-Tex F-TexCo., Co.,Ltd., Ltd., leaf leaf bleached kraft pulp: bleached kraft pulp: 100% bymass, 100% by mass,Canadian Canadian standard freeness: standard freeness: 420 mL,smoothness 420 mL, smoothness F side:430 F side: 430seconds, seconds, W W side: side: 16 16 seconds, seconds, Clupak Clupak

processing was processing wasnot notperformed), performed),totothereby therebyobtain obtainheat-sealable heat-sealable paper paper(smoothness (smoothnessF Fside: side:963 963 seconds, WWside: seconds, side: 219 219seconds). seconds).

[0111]

[Comparative Example

[Comparative Example 6] 6]

mannerasasinin Example manner Example 1 1 except except thatthe that theextensible extensiblepaper paperwas waschanged changedto to thickglassine thick glassinepaper paper having aa basis having basis weight of 30.6 weight of g/m2, aa thickness 30.6 g/m², thickness of 30 m, of 30 um, and aa density µm, and density of of 1.01 g/cm³3 1.01 g/cm

(available from (available from Oji Oji F-Tex Co., Ltd., F-Tex Co., Ltd., needle needle bleached kraft pulp: bleached kraft pulp: 100% bymass, 100% by mass,smoothness smoothnessF F side: 1,300 side: 1,300 seconds, seconds, W side: 1,350 W side: 1,350 seconds), seconds), to to thereby obtain heat-sealable thereby obtain heat-sealable paper paper

(smoothness (smoothness F Fside: side: 1,700 1,700seconds, seconds,WWside: side:1,500 1,500seconds). seconds).

[0112]

[Measurement method]

Theobtained The obtainedheat-sealable heat-sealable paper paperwas wasused usedtotoperform performthe thefollowing followingmeasurements. measurements. <Smoothness> <Smoothness>

TheOken The Okensmoothness smoothness waswas measured measured according according toP8155:2010 to JIS JIS P8155:2010 to determine to determine a a value of value of the the smoothness. smoothness. TheThe smoothness smoothness of the of the paper paper substrate substrate was was measured measured in same in the the same mannerasasdescribed manner describedabove. above.

[0113]

<Clarkstiffness> <Clark stiffness> Each of the Clark stiffnesses of paper in the longitudinal direction and the transverse Each of the Clark stiffnesses of paper in the longitudinal direction and the transverse

direction was direction measuredaccording was measured accordingtotoJIS JISP P8143:2009, 8143:2009, and and both both of of them them were were usedused to to determineaa geometric determine geometricmean, mean,and and thegeometric the geometric mean mean was was defined defined as aas a value value of Clark of Clark

stiffness geometric stiffness geometric mean. mean.

[0114]

<Tearindex <Tear indexofof heat-sealable heat-sealable paper> paper> Thetearing The tearing resistance resistance of of the the heat-sealable heat-sealablepaper paperwas was measured accordingtotoJIS measured according JIS PP 8116:2000. Each 8116:2000. Each of the of the tearing tearing resistancesininthe resistances thelongitudinal longitudinaldirection direction and and the the transverse transverse direction was direction measured,and was measured, andthe theobtained obtainedvalue valuewas wasdivided dividedbybya abasis basisweight, weight,and andthe thethus- thus-

- 32 --

obtained value obtained value was wasdefined definedasasaa tear tear index. From index. From thethe obtained obtained tearindexes tear indexes inin the the

longitudinal direction and the transverse direction, a longitudinal and transverse geometric longitudinal direction and the transverse direction, a longitudinal and transverse geometric

meanwas mean wasdetermined. determined.

[0115]

<Burst index <Burst indexof of heat-sealable heat-sealable paper> paper> Thebursting The bursting strength strength of of the the heat-sealable heat-sealable paper paper was was measured accordingtotoJIS measured according JISPP 8112:2008. 8112:2008. TheThe obtained obtained value value was was divided divided by a by a basis basis weight, weight, and and thus-obtained thus-obtained valuevalue was was

defined as a burst index. defined as a burst index.

[0116]

<Piercing strength> <Piercing strength> Thetest The test was performedaccording was performed accordingtotoJIS JISZ1717:2019. Z1717:2019.

[0117]

<Measurement <Measurement of of heat heat sealingpeel sealing peelstrength> strength> One set of two heat-sealable papers was stacked so that heat-sealable layers face each One set of two heat-sealable papers was stacked SO so that heat-sealable layers face each

other and other heat-sealed using and heat-sealed using a a heat heat seal sealtester tester(TP-701-B, (TP-701-B, available availablefrom from TESTER SANGYO TESTER SANGYO

CO,LTD.) CO, LTD.)under under theconditions the conditionsofof150°C, 150C, 0.2 0.2 MPa, MPa, andand one one second. second. The heat-sealed The heat-sealed test test specimenswere specimens wereleft left standing standingin in aa room at aa temperature room at temperature of 23C+±1°C of 23°C 1Cand anda ahumidity humidity of of 50% 50%

 2% + ± 2%for for44 hours hoursor or more. more.Subsequently, Subsequently, the the test test specimen specimen heat-sealed heat-sealed was was cut cut intointo a width a width

of 15 of 15 mm andT-peeled mm and T-peeled using using a tensiletester a tensile tester at at aa tensile tensilespeed speedofof300 300mm/min, andthe mm/min, and the maximum maximum load load recorded recorded was was taken taken as aasheat a heat sealing sealing peel peel strength. strength.

[0118]

<Drop test using <Drop test using sand> sand> Twosheets Two sheetsofofheat-sealable heat-sealable paper paperwith with400 400square squaremillimeters millimeterswere wereplaced placedwith with the the

surfaces of the heat-sealable paper facing each other, and heat sealing was performed at three surfaces of the heat-sealable paper facing each other, and heat sealing was performed at three

sides, approximately 2 kg of sand was filled thereinto, and the remaining one side was heat- sides, approximately 2 kg of sand was filled thereinto, and the remaining one side was heat-

sealed, to sealed, to thereby thereby produce produce a a packaging bagfilled packaging bag filled with with the the contents. contents. AAdrop droptest testwas wasthen then conductedononthis conducted this according accordingtoto JIS JIS ZZ 0202:2017. 0202:2017.FiveFive bagsbags werewere mademade in same in the the same manner manner

as described as described above for the above for the drop test. The drop test. Thenumber numberof of tornbags, torn bags,the thenumber numberof of broken broken bags, bags,

and the and the number number ofofopened openedheat-sealed heat-sealedportions portionsininall all the the bags were totaled, bags were totaled, followed by followed by

determination based on the following criteria (only A is acceptable). determination based on the following criteria (only A is acceptable).

A: In the drop test, torn paper, a broken bag, and opening of the heat-sealed portions A: In the drop test, torn paper, a broken bag, and opening of the heat-sealed portions

were not found at all. were not found at all.

B: In the drop test, the total number of torn paper or the number of opened heat-sealed B: In the drop test, the total number of torn paper or the number of opened heat-sealed

portions was 1 or more but 4 or less. portions was 1 or more but 4 or less.

- 33 --

C: In the drop test, the total number of torn paper or the number of opened heat-sealed C: In the drop test, the total number of torn paper or the number of opened heat-sealed

portions was portions was 55 or or more. more.

[0119]

<Drop test using <Drop test using gravel> gravel> Twosheets Two sheetsofofheat-sealable heat-sealable paper paperwith with400 400square squaremillimeters millimeterswere wereplaced placedwith with the the

sides, approximately 2 kg of gravel (sharper than sand) was filled thereinto, and the remaining sides, approximately 2 kg of gravel (sharper than sand) was filled thereinto, and the remaining

one side one side was heat-sealed, to was heat-sealed, to thereby thereby produce produce aa packaging bagfilled packaging bag filled with with the the contents. contents. A A

drop test drop test was was then then conducted onthis conducted on this according according to to JIS JIS Z 0202:2017.FiveFive Z 0202:2017. bags bags were were mademade in in the same the mannerasasdescribed same manner describedabove above forthe for thedrop droptest. test. TheThe number number of torn of torn bags, bags, the the number number

of broken bags, and the number of opened heat-sealed portions in all the bags were totaled, of broken bags, and the number of opened heat-sealed portions in all the bags were totaled,

followed by determination based on the following criteria (only A is acceptable). followed by determination based on the following criteria (only A is acceptable).

A: In the drop test, torn paper and a broken bag were not found at all. A: In the drop test, torn paper and a broken bag were not found at all.

B: In the drop test, the total number of torn paper or the number of broken bags was 1 B: In the drop test, the total number of torn paper or the number of broken bags was 1

or more but 4 or less. or more but 4 or less.

C: In the drop test, the total number of torn paper or the number of broken bags was 5 C: In the drop test, the total number of torn paper or the number of broken bags was 5

or more. or more.

[0120]

<Ease of opening <Ease of openingtest> test> The heat-sealed portion of a packaging bag similar to that used in the drop test was The heat-sealed portion of a packaging bag similar to that used in the drop test was

pulled in both directions perpendicular to the heat-sealed surface without tearing (by pulling pulled in both directions perpendicular to the heat-sealed surface without tearing (by pulling

both sheets of heat-sealed paper in opposite directions so as to peel the heat-sealed layers both sheets of heat-sealed paper in opposite directions SO so as to peel the heat-sealed layers

from each from eachother), other), and the ease and the ease of of opening at the opening at the time time of of opening opening was evaluated as was evaluated as follows. follows. A: AApackaging A: packagingbag bagcould could bebe easilyopened. easily opened. B: A packaging bag was very tight and is difficult to open. B: A packaging bag was very tight and is difficult to open.

[0121]

<Blockingresistance> <Blocking resistance> Ten sheets of the heat-sealable paper were laminated so that the coated surface and the Ten sheets of the heat-sealable paper were laminated SO so that the coated surface and the

non-coatedsurface non-coated surfacewere wereinincontact contact with witheach eachother, other, and and were werepressed pressedatat aa pressure pressure of of 20 20

2 15 hours while the sheets were heated to 40°C in the longitudinal direction with a kgf/cm for 15 hours while the sheets were heated to 40C in the longitudinal direction with a kgf/cm2 for kgf/cm²

hot press hot press machine. After machine. After thethe pressurewaswas pressure released,thethepaper released, paperwas was taken taken out.Then. out. Then, Then, the the result obtained result obtained when the sheets when the sheets were peeledwith were peeled withhand handwas wasevaluated. evaluated. A: Neither A: Neither breakage breakagenor norpaper paperpeeling peelingwas wasfound. found. B: Either B: Either breakage or paper breakage or paper peeling peeling was wasfound. found.

[0122]

- 34 --

Heat-sealable paper Heat-sealable paper was wascontinuously continuouslymade made into into bags bags using using a high-speed a high-speed transverse transverse

pillow packing pillow packingmachine machine(Wrapper (aWrapper FW3410, available from FW3410,available (Wrapper FW3410, available fromFUJI from FUJIMACHINERY FUJI MACHINERYCO., MACHINERY CO., CO.,

LTD.).At At LTD.). this this time,nonocontents time, contentswere were put put intothe into thebag, bag,but butananempty emptybag bag was was used used forfor

molding,and molding, andthe theappearance appearanceand andthe therunnability runnabilitywere werechecked checkedto to determine determine thethe followings. followings.

Here, "continuous Here, "continuousbag bagmaking making was was impossible" impossible" means means a state a state in which in which wrinkles wrinkles werewere

generated, aa state generated, statein inwhich which aabag bag could could not not formed due to formed due to meandering, oraa paper meandering, or paper break break occurred. TheThe occurred. phrase phrase "bad "bad appearance" appearance" means means the presence the presence of wrinkles, of wrinkles, misalignment misalignment of theof the sealed portion, or deformation of the bag (A and B are acceptable). sealed portion, or deformation of the bag (A and B are acceptable).

A: Continuous A: Continuousbag bagmaking making waswas possible, possible, andand thethe appearance appearance of the of the bagbag waswas good. good.

B: Continuous B: Continuousbag bagmaking making waswas possible, possible, butbut thethe appearance appearance of of thethe bagbag waswas slightly slightly defective. defective.

C: Continuous C: Continuousbag bagmaking makingwaswas impossible. impossible.

[0123]

- 35 -- Table 1 Heat-sealable paper Heat-sealable layer Paper substrate beating after Freeness stiffness/basis Clark smoothness side W packaging Automatic strength peel sealing Heat smoothness side W smoothness side F resistance Blocking stiffness Clark smoothness Fside (gravel) test Drop strength Piercing formability Ease of opening Drop test (sand) Burst index Tear index Thickness Basis weight Thickness Basis weight weight Density Density Kind Table 11 Table layer Heat-sealable Example 1 Example 1 Example 2 Example 2 Example3 3 Example Example 4 Example 4 Example 5 Example 5 Example 6 Example 6 Example 7 Example 7 Example 8 Example 8 Example 9 Example 9 Example 10 Example 10 Example 11 Example 11 Example 12 Example 12 Example 13 Example 13 Heavy-duty Heavy-duty Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Extensible Kind Kind - packaging packaging paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper paper Freenessafter afterbeating beating mL 677 563 578 563 677 563 677 677 677 563 677 563 563 Paper substrate

Freeness 677 563 578 563 677 563 677 677 677 563 677 563 563 mL mean geometric transverse (mN-m²/g) Transverse (mN-m²/g) Longitudinal mean geometric transverse (m²/g) Longitudinal mean geometric transverse agent main of Kind (m²/g) Transverse g/m2 and Longitudinal Basis weight 82.9 78.3 79.2 78.3 82.9 78.3 82.9 82.9 82.9 78.3 100.0 78.3 78.3 Longitudinal and Longitudinal and Basis weight g/m² 82.9 78.3 79.2 78.3 Transverse Longitudinal 82.9 78.3 82.9 82.9 82.9 78.3 100.0 78.3 78.3 Lubricant N/15mm kPa.m²/g (mN-m²/g) Pigment Second Second Tg (°C) Second Second m (m²/g) g/cm³ g/cm³ g/m² g/m² Thickness Thickness - I - - - 123 123 126 126 132 132 126 126 123 123 µm 126 126 123 123 123 123 123 123 µm126 126 mL149 149 - 126 126 126 126 um Density Density g/cm3 g/cm³ N 0.67 0.67 0.62 0.62 0.60 0.60 0.62 0.62 0.67 0.67 0.62 0.62 0.67 0.67 0.67 0.67 0.67 0.67 0.62 0.62 0.67 0.67 0.62 0.62 0.62 0.62 F side F side smoothness smoothness Second Second 4 4 12 12 3 3 12 12 4 4 12 12 4 4 4 4 4 4 12 12 7 7 12 12 12 12 Extensible Example 1 Paraffin W side smoothness W side smoothness Second 6.0Second 6.0 14.0 17.9 720.7 7 15.5 29 29 0.49 0.52 2 2 0.47 45.9 29 43.5 29 48.4 7 7 0.78 120 29 29 93.0 None wax 7 7 7 7 SBR 7 7 0.67 12329 29 82.9 677 1818 paper 29 29 29 29 64 18 A A A A AKind of main agent 8 7 4 Heat-sealable layer

Ethylene- Ethylene- Kind of main agent SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR SBR acrylic acid acrylic acid Paraffin Extensible Example 2 None paper Tg 5.0 Tg12.9 (C)4.2 (°C) 17.2 18 20.0 18 14.8 18 0.49 18 0.43 18 0.54 18 43.8 45 39.2 45 48.9 61 18 18 15 0.75 120 18 90.2 18 wax 18 18 18 18 SBR 18 29 1218 18 0.62 12618 18 78.3 563 1818 18 18 18 18 Heat-sealable A layer Heat-sealable layer A A A A Lubricant Lubricant Paraffin Paraffin Paraffin Paraffin Paraffin Paraffin Carnauba Carnauba PE wax PE wax Paraffin Paraffin None Paraffin Paraffin Carnauba Carnauba PE wax PE wax Paraffin Paraffin Paraffin Paraffin Carnauba Carnauba None wax wax wax wax wax wax wax wax 167.9 wax wax Paraffin wax wax wax wax wax wax paper

packaging wax Heavy-duty wax Example 3 wax wax 0.56 91.2 49.5 0.69 89.2 None wax 0.60 79.2 7.0 10.5 12.9 14.5 11.5 1.02 1.88 130 SBR 132 578 Pigment3.8 Pigment None None None None None None None None None 65 None 25 None None None 18 None Kaolin Kaolin None None None None None None Kaolin Kaolin None None Basis weight Basis weight C A A B A g/m22 g/m 93.0 93.0 90.2 90.2 89.2 89.2 90.3 90.3 93.1 93.1 90.2 90.2 93.0 93.0 93.0 93.0 93.0 93.0 2 3 90.2 90.2 110.2 110.2 90.2 90.2 90.2 90.2 m Ethylene- Thickness 120 120 130 120 120 140 120 120 120 120 140 120 120 Carnauba acrylic acid Extensible Example 4 Thickness 120 120 130 120 120 140 None 120 120 120 120 140 120 120 6.5 um paper 0.49 0.45 0.54 44.2 40.2 48.6 0.75 0.62 13.1 4.4 17.5 19.8 15.5 120 90.3 wax 126 78.3 563 Density Density g/cm3 g/cm³ 0.78 0.78 0.75 0.75 0.69 0.69 0.75 0.75 82 0.78 0.78 0.64 0.64 0.78 0.78 45 0.78 29 12 0.78 0.78 0.78 0.75 0.75 0.79 0.79 0.75 0.75 0.75 0.75 F side F A side smoothness smoothness A A A A Second Second 8 8 15 15 25 25 8 8 8 8 8 12 12 8 8 88 8 8 15 15 8 8 15 15 15 15 - 35 W side smoothness Second 64 61 65 82 42 40 60 12 64 0.67 42 57 24 Example 5 62 Extensible W side smoothness Second 64 61 65 82 42 PE wax 60 12 64 42 57 24 62 14.0 17.6 20.2 15.3 0.50 0.53 0.47 46.5 49.7 43.5 0.78 40 93.1 None SBR 82.9 paper 6.5 6.1 120 123 677 Longitudinal Longitudinal 43.5 43.5 48.9 167.9 48.6 42 43.5 43.5 59.0 43.5 18 43.5 43.5 43.5 48.7 70.4 48.0 48.0 A A A A A Transverse Transverse 48.4 48.4 48.9 39.2 39.2 167.9 49.5 49.5 48.6 40.2 40.2 49.7 49.7 8 59.0 52.6 52.6 43.5 48.4 48.4 48.4 48.4 7 443.5 48.4 48.4 48.7 39.4 39.4 70.4 67.6 67.6 48.0 42.2 42.2 48.0 42.2 42.2 Clarkstiffness Clark stiffness Longitudinal andand Example 6 Extensible Longitudinal Paraffin 13.1 4.6 geometric 4.3 mean 18.0 45.9 45.9 20.8 15.6 43.8 43.8 0.62 0.58 91.2 91.2 0.65 55.7 44.2 44.2 52.6 59.0 46.5 46.5 0.64 140 55.7 55.7 90.2 None wax 45.9 45.9 45.9 45.9 SBR 45.9 45.9 0.62 43.8 126 43.8 78.3 69.0 69.0 563 paper 45.0 45.0 45.0 45.0 transverse transverse geometric mean 40 12 18 29 12 B A A A A Longitudinal Longitudinal (m (m 2 ²/g)/g) 0.47 0.47 0.54 0.54 1.88 1.88 0.54 0.54 0.47 0.47 0.65 0.65 0.47 0.47 0.47 0.47 0.47 0.47 0.54 0.54 0.64 0.64 0.53 0.53 0.53 0.53 2 Transverse Transverse (m (m /g) ²/g) 0.52 0.52 0.43 0.43 0.56 0.56 0.45 0.45 0.53 0.53 0.58 0.58 0.52 0.52 0.52 0.52 0.52 0.52 0.44 0.44 0.61 0.61 Extensible 0.47 0.47 Example 7 0.47 0.47 Clark stiffness/basis Clark stiffness/basis Heat-sealable paper

20.7 0.49 0.52 0.47 45.9 48.4 43.5 0.78 93.0 None None 0.67 82.9 paper 6.8 14.0 and 17.9 15.5 SBR weight weight Longitudinal Longitudinal and 6.0 60 120 18 123 677 B B A A A transversegeometric transverse geometricmean mean 0.49 0.49 0.49 0.49 1.02 1.02 0.49 0.49 0.50 0.50 8 0.62 0.62 0.49 0.49 0.49 0.49 7 40.49 0.49 0.49 0.49 0.63 0.63 0.50 0.50 0.50 0.50 (m2/g) (m2/g) Paraffin Extensible Example 8 Kaolin 2 Longitudinal Longitudinal 5.6 14.0 (mNm (mNm2/g) 6.0 /g) 17.9 15.5 15.5 20.7 15.5 14.8 14.8 0.49 0.52 11.5 11.5 0.47 45.9 15.5 15.5 48.4 43.5 15.3 15.3 0.78 120 15.6 15.6 93.0 wax 15.5 15.5 15.5 15.5 SBR 15.5 15.5 0.67 123 14.8 14.8 82.9 14.2 14.2 677 paper 14.3 14.3 14.3 14.3 12 18 A A A A A Transverse Transverse (mNm2/g) (mN.m2/g) 20.7 20.7 20.0 20.0 14.5 14.5 19.8 19.8 20.2 20.2 8 20.8 20.8 20.7 20.7 20.7 20.7 7 420.7 20.7 20.0 20.0 23.0 23.0 19.6 19.6 19.8 19.8 Tear index Tear index Longitudinal Longitudinal andand Carnauba Extensible Example 9 transverse transverse geometric geometric 6.0 14.0 6.0 mean mean 17.9 17.9 17.9 20.7 15.5 17.2 17.2 0.49 0.52 12.9 12.9 0.47 45.9 17.5 17.5 48.4 43.5 17.6 17.6 0.78 120 18.0 18.0 93.0 None wax 17.9 17.9 17.9 17.9 SBR 17.9 17.9 0.67 123 17.2 17.2 82.9 18.1 18.1 677 paper 16.7 16.7 16.8 16.8 64 18 A A A A A (mNm2/g) (mNm2/g) Burstindex Burst index kPam2/g kPa-m2/g 6.0 6.0 4.2 4.2 3.8 3.8 4.4 4.4 6.1 6.1 8 4.3 4.3 6.0 6.0 6.0 6.0 7 4 6.0 6.0 4.2 4.2 4.8 4.8 4.2 4.2 4.2 4.2 Example 10 Extensible Piercing strength N 4.2 14.0 12.9 0.44 10.5 13.1 14.0 13.1 PE wax Piercing strength 5.5 N 13.0 17.2 14.0 20.0 14.8 12.9 0.49 10.5 0.54 43.8 13.1 39.4 48.7 14.0 0.75 120 13.1 90.2 None 14.0 14.0 14.0 14.0 SBR 14.0 14.0 0.62 126 13.0 13.0 78.3 16.9 16.9 563 paper 12.9 12.9 12.9 12.9 42 29 12 Heatsealing sealing A peel strength A N/15mm 6.0 5.0 7.0 6.5 6.5 15 4.6 6.8 18 5.6 6.0 5.5 7.0 5.5 6.0 Heat peel strength A A A N/15mm 6.0 5.0 7.0 6.5 6.5 4.6 6.8 5.6 6.0 5.5 7.0 5.5 6.0 Droptest Drop test(sand) (sand) -- A A A A A A A A A A A A A A A A A A A A A A Extensible

A AExample 11

A A Paraffin Droptest Drop test(gravel) (gravel) -- 7.0 16.9 4.8 18.1 A A 23.0 14.2 A 0.63 A 0.61 B B 0.64 69.0 A 67.6 A 70.4 A A 0.79 140 A 110.2 A None wax A A AA SBR A A 0.67 149 A A 100.0 677 A A paper A A A A 57 18 18 Ease A A Easeofofopening opening A A A - - A A A A A A A A A 8 A A A A A AA 7AAA A A A A A A A A Blocking Blocking resistance resistance - - A A A A A A A A A A A A B B A A A A A A A A AExample 12

A A Extensible Paraffin Automatic packaging Automatic packaging Kaolin paper 5.5 - 12.9 - 4.2 16.7 A A 19.6 14.3 A 0.50 A 0.47 C 0.53 C 45.0 A 42.2 A 48.0 24 A A 0.75 120 B 90.2 B wax B B 18 A SBR A 29 A 12A 0.62 126A A 78.3 563 A A A A AA formability formability 15 A A A A A Example 13 Carnauba Extensible 0.50 0.47 0.53 45.0 42.2 48.0 0.75 90.2 None 0.62 paper 6.0 12.9 4.2 16.8 19.8 14.3 120 wax SBR 126 78.3 563 62 15 18 29 12 A A A A A

- 36 --

[0124]

Table 22 Table Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Example1 1 Example Example2 2 Example Example3 3 Example Example4 4 Example Example5 5 Example Example6 6 Example

Unbleached Unbleached Unbleached Unbleached Heavy- Heavy- One-side One-side One-side One-side One-side Thick Thick Kind - light-duty light-duty light-duty light-duty duty duty glazed glazed glazed glazed glassine glassine Kind glassine - - packaging packaging packaging packaging packaging packaging kraft kraft kraft kraft paper paper paper paper paper paper paper paper paper paper paper paper Freeness after beating Freeness after beating mL mL 478 478 478 478 578 578 578 578 420 420 - -- Paper Paper Paper Basis weight Basis weight g/m²2 g/m g/m² 80.5 80.5 70.0 70.0 79.2 79.2 78.2 78.2 50.7 50.7 30.6 30.6 substrate substrate Thickness Thickness m 114 114 100 100 132 132 100 100 61 61 30 30 um µm Density Density g/cm3 g/cm³ 0.71 0.71 0.70 0.70 0.60 0.60 0.78 0.78 0.83 0.83 1.01 1.01

F side smoothness F side smoothness Second Second 17 17 16 16 33 3 120 120 120 430 430 1300 1300 W side smoothness W side smoothness Second Second 16 16 16 14 14 14 2 2 18 18 16 16 1350 1350

Kindof Kind of main main SBR PE- PE- PE- Ethylene- Ethylene- SBR SBR SBR agent agent SBR laminated laminated vinyl acetate vinyl acetate SBR SBR SBR Heat- Heat- Heat-sealable sealable sealable Heat-sealable Tg (°C) Tg Tg (C) (C) 18 18 - -- 0 0 18 18 18 18 18 18 layer layer layer layer layer Paraffin Paraffin Paraffin Paraffin Paraffin Paraffin Paraffin Paraffin Paraffin Paraffin Paraffin Lubricant Lubricant None None None None wax wax wax wax wax wax wax wax Pigment Pigment None None None None None None None None None None None None Basis weight Basis weight g/m2 g/m² 90.5 90.5 89.2 89.2 89.3 89.3 88.9 88.9 60.2 60.2 40 40 Thickness Thickness m 115 115 123 123 123 130 130 95 95 62 62 40 40 µm um Density Density g/cm3 g/cm³ 0.79 0.79 0.73 0.73 0.69 0.69 0.94 0.94 0.97 0.97 1.00 1.00

F side smoothness F side smoothness Second Second 89 89 16 16 16 25 25 300 300 963 963 1700 1700 W side smoothness W side smoothness Second Second 219 219 140 140 56 56 291 291 219 219 1500 1500 Longitudinal Longitudinal 158.0 158.0 130.0 130.0 168.2 168.2 40.2 40.2 40.2 40.2 10.3 10.3

Transverse Transverse 57.6 57.6 57.3 57.3 50.6 50.6 18.3 18.3 18.3 18.3 4.4 4.4 Clark stiffness Clark stiffness Longitudinal Longitudinal and transverse and transverse 95.4 95.4 86.3 86.3 92.3 92.3 27.1 27.1 27.1 27.1 6.7 6.7 geometric mean geometric mean longitudinal longitudinal longitudinal 2/g) (m²/g) (m (m²/g) 1.75 1.75 1.46 1.46 1.88 1.88 0.45 0.45 0.67 0.67 0.67 0.26 0.26

Transverse Transverse Clark Clark (m (m 2/g) ²/g) (m²/g) 0.64 0.64 0.64 0.64 0.57 0.57 0.21 0.21 0.30 0.30 0.11 0.11 stiffness/Basis stiffness/Basis

weight weight Longitudinal Longitudinal and transverse and transverse 1.05 1.05 0.97 0.97 1.03 1.03 0.30 0.30 0.45 0.45 0.17 0.17 Heat- Heat- geometric geometric mean geometric mean mean 2/g) sealable sealable sealable (m (m ²/g) (m²/g)

paper paper Longitudinal Longitudinal 2/g) 12.4 12.4 10.8 10.8 11.5 11.5 7.1 7.1 6.6 6.6 4.1 4.1 4.1 (mNm (mN.m²/g) (mNm2/g)

Transverse Transverse (mNm2/g) (mN-m²/g) (mNm2/g) 16.0 16.0 14.9 14.9 14.5 14.5 7.5 7.5 7.2 7.2 4.5 4.5 Tear index Tear index Longitudinal Longitudinal and and transverse and transverse transverse 14.1 14.1 12.7 12.7 12.9 12.9 7.3 7.3 6.9 6.9 4.3 4.3 4.3 geometric mean geometric mean 2/g) (mNm (mN.m2/g) (mN-m²/g)

Burst Burst index Burst index index kPam2/g kPa.m2/g kPa-m²/g 2.6 2.6 3.5 3.5 3.9 3.9 3.7 3.7 4.2 4.2 3.6 3.6

Piercing strength Piercing Piercingstrength strength N N 8.9 8.9 8.9 9.5 9.5 10.5 10.5 5.9 5.9 4.7 4.7 1.8 1.8

Heat sealing Heat sealing peelpeel N/15mm 5.0 5.0 20.0 20.0 12.0 12.0 5.0 5.0 4.8 4.8 3.3 3.3 strength strength N/15mm Droptest Drop test (sand) (sand) - -- C C B B A A C C C C C C C Droptest Drop test(gravel) (gravel) C C C C B B C C C C C C Ease of Ease of opening opening - - A A B B B B A A A A A A Blocking resistance Blocking resistance - - A A A A A A A A A A A A Automaticpackaging Automatic packaging formability formability - - C C C B B C C C A A A A A A

[0125]

37 -- 23 May 2025 2023290887 23 May 2025

FromTable From Table1,1,the thepackaging packagingbags bagsobtained obtained from from thethe heat-sealablepaper heat-sealable paper ofof Examples Examples

11 to to 13 13 were were excellent excellent in indrop drop impact impact resistance resistance and and were were prevented frombeing prevented from beingtorn. torn. In In addition, addition, these these packaging bags were packaging bags wereeasily easily opened openedatat the the time time of of opening. opening.

In In contrast, contrast,from from Table Table 2, 2, the thepackaging packaging bag bag obtained fromthe obtained from the heat-sealable heat-sealable paper paper of of Comparative Example Comparative Example 1 having 1 having a burst a burst index index of of less less than kPam2/g than3.03.0kPa.m²/g waswas deteriorated deteriorated in in

drop impact drop impactresistance resistance and and was wastorn. torn. TheThe packaging packaging bag bag obtained obtained fromfrom the heat-sealable the heat-sealable 2023290887

paper of paper of Comparative Example Comparative Example 2, 2, which which was was obtained obtained by providing by providing a PE alayer PE layer on on unbleachedlight-duty unbleached light-duty packaging packagingpaper paperthrough through lamination lamination andand hadhad a heat a heat sealing sealing peel peel

strength strength of of more than 10 more than 10 N/15 N/15mm, mm, was was deteriorated deteriorated inin dropimpact drop impact resistanceand resistance and easeofof ease

opening. Moreover, opening. Moreover, the the packaging packaging bag bag obtained obtained from from the heat-sealable the heat-sealable paperpaper of of

Comparative Example Comparative Example 3 having 3 having a heat a heat sealing sealing peel peel strength strength ofof more more than than 10 10 N/15 N/15 mm was mm was

deteriorated in deteriorated in ease easeof ofopening. Thepackaging opening. The packaging bags bags obtained obtained from from the the heat-sealable heat-sealable paper paper

of Comparative of Examples Comparative Examples 4 to 4 to 6 each 6 each having having a longitudinal a longitudinal andand transverse transverse geometric geometric mean mean

2 of aa tear of tearindex indexof ofless than less 1010mNm than /g were mN.m²/g deteriorated in were deteriorated in drop drop impact resistance and impact resistance and were were

torn. torn.

Theheat-sealable The heat-sealable paper paper of of Examples Examples1 1toto66and and8 8toto13, 13, which whichcontained containeda alubricant, lubricant, were excellent in were excellent in blocking resistance. InInaddition, blocking resistance. addition, comparison comparisonbetween between Example Example 2 and 2 and

Example6 6found Example foundthat thatsuper supercalendering calenderingdecreases decreasesClark Clark stiffnessand stiffness andimproves improves heatsealing heat sealing peel strength. peel strength.

[0126]

It can be said from the above results that the heat-sealable paper of the present It can be said from the above results that the heat-sealable paper of the present

embodiment makes it possible to obtain a packaging bag that is difficult to tear and can be embodiment makes it possible to obtain a packaging bag that is difficult to tear and can be

easily opened at the time of opening. easily opened at the time of opening.

[0127]

Unless the context Unless the requires otherwise, context requires otherwise, where the terms where the terms "comprise", “comprise”,"comprises", “comprises”, “comprised” or “comprising” are used in this specification (including the claims) they are to "comprised" or "comprising" are used in this specification (including the claims) they are to

be interpreted as specifying the presence of the stated features, integers, steps or components, be interpreted as specifying the presence of the stated features, integers, steps or components,

but not precluding the presence of one or more other features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components,

or groupthereof. or group thereof.

Claims

- 38 -- 2023290887 12 Mar 2025 THE CLAIMS THE CLAIMS DEFINING DEFINING THE THE INVENTION INVENTIONARE AREAS ASFOLLOWS: FOLLOWS:

1. 1. Heat-sealable paper Heat-sealable paper comprising comprisingone oneorormore more heat-sealablelayers heat-sealable layersononatatleast least one one surface ofaapaper surface of papersubstrate, substrate, wherein wherein

the heat-sealable layer comprises a water-dispersible resin binder, the heat-sealable layer comprises a water-dispersible resin binder,

aa longitudinal and longitudinal and transverse transverse geometric geometric mean mean of ofindex a tear a tearofindex of the heat-sealable the heat-sealable paper paper 2 or more, is 10 is 10 mNm mN.m²/g/g or more, 2023290887

aa burst indexofofthe burst index theheat-sealable heat-sealable paper paper is kPa.m²/g is 3.0 3.0 kPamor 2more, /g or and more, and whentwo when twosuch suchheat-sealable heat-sealablelayers layersare areheat-sealed heat-sealed to to each each other other at at 150C and0.2 150°C and 0.2 MPa MPa for one for one second, second, a a heat heat sealing sealing peel peelstrength strengthisis 2.02.0 N/15 N/15mm mm or or more and 10 more and 10N/15 N/15mmmm or or less. less.

2. 2. The heat-sealable paper according to claim 1, wherein the heat-sealable layer further The heat-sealable paper according to claim 1, wherein the heat-sealable layer further

comprises a lubricant. comprises a lubricant.

3. 3. The heat-sealable paper according to claim 2, wherein the lubricant comprises at least The heat-sealable paper according to claim 2, wherein the lubricant comprises at least

one selected from one selected the group from the group consisting consisting of of paraffin paraffin wax, wax, carnauba wax,and carnauba wax, andpolyolefin polyolefinwax. wax.

4. 4. The heat-sealable paper according to claim 2 or 3, wherein a content of the lubricant in The heat-sealable paper according to claim 2 or 3, wherein a content of the lubricant in

the heat-sealable the heat-sealable layer layerisis1% 1% by by mass or more mass or and5% more and 5%bybymass mass or or less. less.

5. 5. Theheat-sealable The heat-sealable paper paper according accordingtoto any anyone oneofofclaims claims11to to 4, 4, wherein wherein aa glass glass transition temperature of the water-dispersible resin binder is 0C or more and 100C or less. transition temperature of the water-dispersible resin binder is 0°C or more and 100°C or less.

6. 6. Theheat-sealable The heat-sealable paper paper according accordingtoto any anyone oneofofclaims claims11to to 5, 5, wherein the water- wherein the water- dispersible resin binder comprises at least one selected from the group consisting of a styrene- dispersible resin binder comprises at least one selected from the group consisting of a styrene-

butadiene copolymer butadiene copolymerand and anan olefin-unsaturatedcarboxylic olefin-unsaturated carboxylic acidcopolymer. acid copolymer.

7. 7. Theheat-sealable The heat-sealable paper paper according accordingtoto any anyone oneofofclaims claims22to to 4, 4, wherein the water- wherein the water- dispersible resin dispersible resinbinder bindercomprises comprises a a styrene-butadiene styrene-butadiene copolymer, andthe copolymer, and thelubricant lubricant comprises comprises paraffin wax. paraffin wax.

8. 8. Theheat-sealable The heat-sealable paper paper according accordingtoto any anyone oneofofclaims claims22to to 4, 4, wherein the water- wherein the water- dispersible resin dispersible resinbinder bindercomprises comprises an an olefin-unsaturated olefin-unsaturated carboxylic carboxylic acid acid copolymer, andthe copolymer, and the lubricant comprises lubricant carnaubawax. comprises carnauba wax.

39 --

2023290887 12 Mar 2025

9. 9. Theheat-sealable The heat-sealable paper paper according accordingtoto any anyone oneofofclaims claims11to to 8, 8, wherein Canadian wherein Canadian

standard freeness of standard freeness of pulp pulp constituting constituting the thepaper papersubstrate substrateisis 500 mL 500 mL or ormore more and and 750 mLoror 750 mL

less. less.

10. 10. TheThe heat-sealable heat-sealable paper paper according according to any to any one one of claims of claims 1 to1 9, to wherein 9, wherein a main a main

component component ofofpulp pulpconstituting constitutingthe thepaper papersubstrate substrate is is needle needle unbleached kraft pulp. unbleached kraft pulp. 2023290887

11. 11. TheThe heat-sealable heat-sealable paper paper according according to any to any one one of claims of claims 1 to1 10, to 10, wherein wherein a value a value (Clark (Clark

Clark stiffnessofofthe Clark stiffness theheat-sealable heat-sealable paper paper by a by a basis basis weightweight of the2)heat-sealable (g/m²) (g/m of the heat-sealable paper is paper is

0.20 m2/g or 0.20 m²/g or more moreand and1.20 m2/gororless. 1.20m²/g less.

12. 12. TheThe heat-sealable heat-sealable paper paper according according to any to any one one of claims of claims 1 to1 11, to 11, wherein wherein a piercing a piercing

strength ofthe strength of theheat-sealable heat-sealable paper paper is 10.0 is 10.0 N or N or more. more.

13. 13. TheThe heat-sealable heat-sealable paper paper according according to any to any one one of claims of claims 1 to1 12, to 12, wherein wherein a basis a basis weight weight

of the paper substrate is 50 g/m² or2 more and 150 g/m² or less. of the paper substrate is 50 g/m or more and 150 g/m or less. 2

14. 14. TheThe heat-sealable heat-sealable paper paper according according to any to any one one of claims of claims 1 to1 13, to 13, wherein wherein a basis a basis weight weight

of the heat-sealable layer is 3 g/m² or2 more and 30 g/m² or less. of the heat-sealable layer is 3 g/m or more and 30 g/m or less. 2

15. 15. TheThe heat-sealable heat-sealable paper paper according according to any to any one one of claims of claims 1 to1 14, to 14, wherein wherein a basis a basis weight weight

of the heat-sealable paper is 50 g/m² or 2more and 200 g/m² or less.2 of the heat-sealable paper is 50 g/m or more and 200 g/m or less.

16. 16. TheThe heat-sealable heat-sealable paper paper according according to any to any one one of claims of claims 1 to1 15, to 15, wherein wherein the the paper paper

substrate is extensible substrate is extensiblepaper. paper.

17. 17. A packaging A packaging bag using bag using the heat-sealable the heat-sealable paper paper according according to one to any any of oneclaims of claims 1 to 116. to 16.