JP6631312B2 - Hot melt composition and lid material using the same - Google Patents

Description

The present invention relates to a hot melt composition and a lid material using the same.

  In the field of article packaging, a method of bonding a lid material to an opening of a container via a heat-sealing layer having excellent sealing properties is used for protecting and preserving contents.

  Aluminum foil, polypropylene, polyvinyl chloride, polyethylene terephthalate, etc. sheet, or a lid material made of such a container obtained by vacuum forming a thermoplastic resin sheet such as high impact polystyrene, polypropylene, polyethylene terephthalate (PET) As a method of sealing, a sheet material in which a low-melting point resin such as low-density polyethylene, low-molecular-weight polyester or ethylene-unsaturated ester copolymer is laminated on the bonding surface of the lid material, or only the sealing portion, A method in which a hot melt adhesive is applied in advance is used.

  Above all, hot melt adhesives used for sealing food containers are different from hot melt adhesives intended only for general bonding, and their coating properties, airtightness, water resistance, oil resistance, alkali resistance, and nontoxicity are Of course, the following special qualities are required.

・ Adjustment of adhesive strength is easy. Adhesive force (opening strength) that can be easily bonded can be set to 10N to 15N (easy-opening property).
-There is no zipping (a phenomenon accompanied by strong resistance and sound) at the time of peeling, and the peeling feeling is good. Capable of smooth and even peeling without spilling or scattering contents.

  In recent years, containers made of polyethylene terephthalate have been increasingly used because of their excellent physical properties such as strength, transparency, and heat resistance. However, conventional hot melts using thermoplastic resins such as styrene-based elastomers, ethylene-vinyl acetate copolymers, and polyolefins require the use of a larger amount or a limited type of tackifier resin than usual. Therefore, it has been an issue to achieve a balance between adhesiveness, easy-openability, and peeling sensation.

Then, conventionally, in order to solve the above problems, polyester hot melt adhesives have been proposed as shown in Patent Documents 1 and 2 below.

  Patent Document 1 discloses an easy-opening hot-melt, characterized in that 5 to 25 parts by weight of an ABA type heat-meltable elastomer is blended with 100 parts by weight of a linear polyester and / or a linear copolymerized polyester. Melt adhesive is proposed.

  Patent Document 2 is characterized in that the epoxidized diene-based block copolymer is blended in an amount of 3 to 100 parts by weight with respect to 100 parts by weight of a polyester having a softening point of 100 ° C. or more and 180 ° C. or less. Hot melt adhesives are proposed.

  However, these proposals all use a polyester-based thermoplastic resin, and have low suitability for coating and low safety, and the raw materials that can be used in combination are limited. It was hard to say a melt adhesive. Also, the blocking resistance was not sufficient.

JP-A-9-176610 JP 2000-290629 A

An object of the present invention is to use a highly versatile ethylene-unsaturated ester copolymer to have sufficient sealing properties, easy-opening properties, and smooth peeling without zipping on a polar substrate such as PET. Another object of the present invention is to provide a hot melt composition having excellent coating suitability and blocking resistance.

  The present invention provides an ethylene-unsaturated ester copolymer (A): 20 to 45% by weight, a styrene monomer-grafted polyethylene wax (B): 3 to 45% by weight, and a melting point of 40 ° C or higher and lower than 80 ° C. Wax (C) having a Saybolt universal viscosity at 120 ° C. of 20 to 300 seconds: 30 to 70% by weight, and the total of the wax (B) and the wax (C) is 50 to 80% by weight. And a hot melt composition (provided that the total of the above (A) to (C) is 100% by weight).

  The present invention also relates to the hot melt composition, wherein the wax (B) is a polyethylene wax having styrene grafted in an amount of 20% by weight or more.

  Further, the present invention relates to a cover material comprising a hot-melt layer made of the hot-melt composition provided on one surface of a substrate on which at least two or more types selected from the group consisting of a resin sheet, paper, and aluminum are laminated. .

  The present invention also relates to the lid, wherein the resin sheet is a sheet selected from the group consisting of a polyethylene sheet, a polypropylene sheet, a polyethylene terephthalate sheet, and a vapor-deposited sheet thereof.

  Further, the present invention relates to a member set for an openable sealed container, comprising a container and the lid material.

  Further, the present invention relates to an openable sealed container, wherein an opening of the container is heat-sealed with a hot melt layer in the lid material.

According to the present invention, there is provided a hot melt composition having sufficient sealing properties, easy-opening properties, smooth peeling without zipping, excellent coating suitability, and excellent blocking resistance to a polar substrate such as PET. It becomes possible.

In the present invention, an ethylene-unsaturated ester copolymer (A), a styrene monomer-grafted polyethylene wax (B), and a melting point of 40 ° C or more and less than 80 ° C, and a Saybolt universal viscosity at 120 ° C of 20 to 300. The hot melt composition containing the second wax (C) will be specifically described.

<Ethylene-unsaturated ester copolymer (A)>
The ethylene-unsaturated ester copolymer (A) constituting the hot melt composition of the present invention is obtained by copolymerizing ethylene and an unsaturated ester monomer. Examples of the unsaturated ester monomer include alkyl (meth) acrylates such as methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methyl methacrylate, and isobutyl methacrylate, and maleic acid. Examples include unsaturated carboxylic acid alkyl esters such as dimethyl and diethyl maleate, and carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate. Two or more unsaturated esters may be used. However, glycidyl (meth) acrylate is excluded.

The ethylene-unsaturated ester copolymer (A) may contain any of the above-mentioned unsaturated ester monomers, but vinyl acetate and methyl methacrylate are preferred. The melt flow rate (MFR) of the ethylene-unsaturated ester copolymer is preferably 3 g / 10 minutes or more and 200 g / 10 minutes or less. The melt flow rate is a flow rate (g / 10 minutes) measured at 190 ° C. under a load of 2160 g for 10 minutes, according to JIS K 7210.

The portion derived from the unsaturated ester in the ethylene-unsaturated ester copolymer (A) is preferably from 10% by weight to 34% by weight based on 100% by weight of the total amount of the ethylene-unsaturated ester copolymer. More preferably, the content is 15% by weight or more and 30% by weight or less. When it is within the above range, the adhesiveness, coating suitability, and blocking resistance are excellent.

The amount of the ethylene-unsaturated ester copolymer (A) is as follows: the ethylene-unsaturated ester copolymer (A), the polyethylene wax (B) on which a styrene monomer is grafted, and the melting point of 40 ° C. or more and less than 80 ° C. When the total of the wax (C) having a Saybolt universal viscosity at 120 ° C. of 20 to 300 seconds is 100% by weight, it is preferably 20% to 45% by weight, and 25% to 40% by weight. More preferably, there is. When the amount is less than 20% by weight, the adhesiveness becomes insufficient, and when the amount exceeds 45% by weight, coating suitability is remarkably reduced.

<Wax (B)>
The wax (B), which is an essential component of the hot melt composition, is not particularly limited as long as it is a wax in which styrene is graft-polymerized, and a wax in which a styrene monomer is graft-polymerized in a polyethylene-polypropylene copolymer is preferable. One type or two or more types can be used.
It is important that the wax (B) is graft-polymerized with styrene, and it is preferable that the wax (B) is grafted in an amount of 20% by weight or more, more preferably 40% by weight or more in 100% by weight of the wax. When the styrene monomer is grafted in an amount of 40% by weight or more, it becomes easy to achieve both the adhesion to a polar substrate such as PET, the easy-opening property, and the feeling of peeling.

In the present specification, the measurement of the graft ratio of the styrene monomer is a solvent fractionation method, that is, a predetermined amount of a hot melt resin is completely dissolved in p-xylene at 135 ° C., and after cooling, the ratio of p-xylene / acetone is 1 : Acetone was added to obtain a mixture of 3, and the mixture was stirred and filtered with a glass filter. At this time, the styrene-grafted homopolymer is completely dissolved in the solvent and separated. For the polymer separated by filtration, the graft ratio was determined from the absorbance at 1601 cm ^{-1 by} the IR method.

  The melting point of the wax (B) is not particularly limited, but is preferably from 80 to 120C. The melt viscosity (140 ° C.) is preferably from 10 to 2000 mPa · s, and the penetration (25 ° C.) is preferably from 0.5 to 20 dmm.

It is important that the blending amount of the polyethylene wax (B) is 3% by weight to 45% by weight when the total of the above (A) to (C) is 100% by weight, and 10% by weight to 40% by weight. Is preferred. When the amount is less than 3% by weight, the adhesiveness becomes insufficient. When the amount exceeds 45% by weight, the compatibility with other components deteriorates, and the adhesiveness decreases.

<Wax (C)>
The wax (C) which is an essential component of the hot melt composition preferably has a melting point of 40 or more and less than 80 ° C. When the melting point is in the above-mentioned range, it becomes easy to achieve both adhesion and coating suitability. In the present invention, the melting point is a temperature at a peak top when the temperature is raised at 10 ° C./min in a differential scanning calorimeter (DSC) measurement.

The Saybolt universal viscosity at 120 ° C. of the wax (C) is preferably from 20 to 300 seconds, more preferably from 25 to 100 seconds. When the Saybolt universal viscosity is in the above range, coating suitability is improved. The Saybolt universal viscosity is represented by the number of seconds for a 60 mL sample to flow out of the Saybolt universal viscometer.

Examples of the wax (C) include paraffin wax, microcrystalline wax, montan wax, Fischer-Tropsch wax, polyethylene wax and the like. Among these, paraffin wax is preferred. These waxes (C) can be used alone or in combination of two or more.

The amount of the wax (C) is preferably 30% by weight to 70% by weight, and more preferably 40% by weight to 60% by weight, when the total of the above (A) to (C) is 100% by weight. . If the amount is less than 30% by weight, the coating aptitude decreases, and if it exceeds 70% by weight, the adhesiveness decreases.

The hot-melt composition of the present invention is characterized in that the ethylene-unsaturated ester copolymer (A), the wax (B), and the wax (C) are (A) :( B) :( C) = 20 to 45: 3 to 45:30 to 70 (% by weight), and (A) :( B) :( C) = 25 to 40:10 to 40:40 to 60 (% by weight). It is preferable to contain it in the composition. The sum of the wax (B) and the wax (C) is 50 to 80% by weight, preferably 60 to 75% by weight. However, the total of (A), (B) and (C) is 100% by weight.

The total amount of the ethylene-unsaturated ester copolymer (A), the wax (B), and the wax (C) is preferably 80% by weight or more, more preferably 85% or more, in 100% by weight of the hot melt composition. More preferably, it is 90% by weight or more.
The resin composition of the present invention contains the ethylene-unsaturated ester copolymer (A) in a range not incompatible with the object of the present invention, that is, within a range that does not impair the PET adhesiveness, easy-opening property, peeling feeling, and blocking resistance. ), Wax (B) and a resin other than wax (C).

Specific examples of such a resin include polyolefin resins such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, and polybutene; and ethylene-non-polymers such as ethylene- (meth) acrylic acid copolymer. As various elastomers such as a saturated monocarboxylic acid copolymer and a metal salt thereof, an ethylene-propylene copolymer elastomer, an ethylene-1-butene copolymer elastomer, a styrene-butadiene copolymer elastomer and a hydrogenated product thereof, or as a tackifying resin, Known tackifying resins used in the hot melt bonding field, such as aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, aromatic hydrocarbon resins, polyterpene resins, and rosins, are exemplified.
These resins may be used alone or in combination of two or more.

The fusible composition of the present invention can contain, as optional components, an antioxidant, a silane coupling agent, an antiblocking agent, and hydrophobic oxide fine particles.

Antioxidants include, for example, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxy) Phenyl) propionate, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphonate, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene ) Bis [3- (5-tert-butyl-4-hydroxy-m-tolyl] propionate, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,4-di-tert-butylphenyl) ) Pentaerythritol diphosphite and the like.
The phenolic antioxidant is preferably pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], and the phosphorus-based antioxidant is tris (2,4-di-t -Butylphenyl) phosphite is preferred.
These can be used alone or in combination of two or more.

Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltrisilane. Ethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-amino Propyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane 3-mercaptopropyl trimethoxysilane, 3-mercaptopropyl triethoxy silane, mercaptopropyl butyl trimethoxysilane and 3-mercaptopropyl methyl dimethoxy silane, and the like.
These can be used alone or in combination of two or more.

As the antiblocking agent, for example, inorganic fine powder and organic fine powder can be used. As the inorganic fine powder, heavy calcium carbonate, light calcium carbonate, silica, talc, clay, fine silica powder, synthetic silicate, precipitated barium sulfate, calcium silicate, aluminum hydroxide, etc. can be used. Examples of the powder include fillers made of heat-resistant polyethylene, polypropylene, urethane, acrylic, nylon, urea-based resins, and the like, styrene cross-linked fillers, benzoguanamine cross-linked fillers, and the like.
These can be used alone or in combination of two or more.

Examples of the hydrophobic oxide fine particles include silica (silicon dioxide), alumina, titania, calcium oxide, calcium carbonate, calcium sulfate, and calcium silicate.
These can be used alone or in combination of two or more.

Since the amount of the above optional components varies depending on the physical properties, the lower limit cannot be limited. However, the upper limit is preferably 10% by weight or less, more preferably 8% by weight or less, in 100% by weight of the hot melt composition. When the blending amount is 10% by weight or less, bleed-out of an optional component becomes more difficult to occur.

  The hot melt composition of the present invention comprises an ethylene-unsaturated ester copolymer (A), a wax (B), a wax (C) and other optional components used as necessary, such as a roll, a Banbury mixer, a kneader, and a stirrer. Obtained by using a hot-melt adhesive obtained by heating and mixing using a melting pot equipped with, or a single- or twin-screw extruder, or a solvent-type adhesive obtained by dissolving in a suitable solvent and stirring and mixing. be able to. The hot melt composition used in the present invention is preferably a hot-melt adhesive that does not use a solvent.

The hot melt composition of the present invention preferably has a viscosity at 160 ° C of 500 to 50,000 mPa · s. The viscosity is a value measured using a B-type viscometer (measurement conditions: 160 ° C., rotor No. 3, 12 rpm, 30 seconds).

<Lid material>
The hot melt composition of the present invention can be suitably used for a lid material. The lid has a hot-melt composition layer in which the hot-melt composition is applied to one surface of a base material, and can be used for an openable container.
The method for manufacturing the lid material is not particularly limited as long as the target lid material of the present invention can be manufactured, and can be manufactured using a known manufacturing method.
The method for applying the hot melt composition is not particularly limited, and generally known contact coating and non-contact coating are used. Contact coating is a coating method in which a jetting machine is brought into contact with a member or a film when applying a hot melt composition. The non-contact coating is a coating method in which a jetting machine is not brought into contact with a member or a film when a hot melt composition is coated.
Examples of the contact coating method include slot coater coating, gravure coater coating, and roll coater coating. Non-contact coating methods include, for example, spiral coating that can be applied spirally, and wavy coating. Examples include omega coating, control seam coating, slot spray coating that can be applied in a planar manner, curtain spray coating, dot coating that can be applied in a dot form, and bead coating that can be applied in a linear form. The thickness of the hot melt composition is preferably from 1 to 100 μm. The hot melt layer can be crosslinked by heating or ultraviolet irradiation.

The substrate is formed by laminating at least two types selected from the group consisting of a resin sheet, paper, and an aluminum sheet (aluminum foil). For example, as the resin sheet, a polyester resin such as polyethylene terephthalate, a polycarbonate resin, a polyarylate resin, an acrylic resin, a polyphenylene sulfide resin, a polystyrene resin, a vinyl resin, a vinyl chloride resin, a polyimide resin, A resin sheet formed from a resin such as an epoxy resin, a polyolefin-based resin such as polyethylene, polypropylene, and poolinorbornene is exemplified. In addition, a vapor-deposited sheet of these sheets may be used, and examples thereof include a metal-deposited sheet on which a metal such as aluminum is vapor-deposited, and a transparent vapor-deposited sheet on which alumina, silicon oxide, or the like is vapor-deposited. Preferred are a polyethylene sheet, a polypropylene sheet, a polyethylene terephthalate sheet, and a vapor-deposited sheet thereof. As the vapor-deposited sheet, a metal-deposited polyethylene terephthalate sheet, a transparent vapor-deposited polypropylene sheet, and a transparent vapor-deposited polyethylene terephthalate sheet are preferable.
As the lid material, nonwoven fabric, woven fabric, cloth, glass, or the like can be further laminated.

The lamination structure is not particularly limited, but preferred specific examples include “paper / polyethylene”, “polyethylene terephthalate / paper / polyethylene”, and “polyethylene terephthalate / aluminum foil / polyethylene”.
The base material may be subjected to a corona discharge treatment, a plasma treatment, a blast treatment, an easy adhesion treatment such as a chemical etching treatment, an antistatic treatment, a coloring treatment, or the like, if necessary.
The thickness of the substrate is not particularly limited, but is preferably 1 to 300 μm.

<Member set for sealed container, sealed container>
The lid material can be suitably used together with the container as a member set for a sealed container that can be opened. In addition, the above set is used by heat-sealing an opening of a container and a lid with a hot melt layer.

  Hereinafter, the present invention will be described specifically and in detail with reference to examples. However, these examples are merely one embodiment of the present invention, and the present invention is not limited to these examples. In the examples, “parts” means “parts by weight”, and “%” means “% by weight”.

<Preparation method of hot melt composition>
The styrene graft wax (B) and the paraffin wax (C) were added to the stainless beaker provided with the stirrer at the ratio of the raw materials shown in Table 1, and the contents were heated so that the temperature did not exceed 180 ° C. After confirming the melting of the contents, stirring is started, and the ethylene-unsaturated ester copolymer (A) and, if necessary, additives are added, and the mixture is stirred until it is completely mixed. Got.

The raw materials described in Table 1 are as follows.
<Ethylene-unsaturated ester copolymer (A)>
A1: Ultracene 710 (ethylene-vinyl acetate copolymer manufactured by Tosoh Corporation, vinyl acetate content 28%, MFR 18 g / 10 minutes)
A2: Ultracene 680 (ethylene-vinyl acetate copolymer manufactured by Tosoh Corporation, vinyl acetate content 20%, MFR 160 g / 10 min)

<Wax (B)>
B1: High Wax 1160H (manufactured by Mitsui Chemicals, Inc., ethylene / propylene copolymer grafted with 60% by weight of styrene monomer, DSC melting point: 104 ° C., melt viscosity (B type viscometer, 140 ° C.): 1100 mPa · s, needle (Dip: 1.0 dmm / 25 ° C)
B2: High wax 1120H (manufactured by Mitsui Chemicals, ethylene / propylene copolymer grafted with 20% by weight of styrene monomer, DSC melting point: 107 ° C, melt viscosity (B-type viscometer, 140 ° C): 40 mPa · s, needle (Dip: 7.0 dmm / 25 ° C)

The melt viscosity of the wax (B) was measured according to JIS K6862. The measurement was performed using a B-type viscometer under the conditions of a temperature of 140 ° C., a rotation speed of 60 rpm, and 30 seconds, and an appropriate rotor was used as necessary.
The penetration of the wax (B) was measured according to JIS K2207. Specifically, the penetration depth when a needle having a conical tip with a diameter of about 1 mm and a vertex angle of 9 ° is vertically entered with a constant load is read in units of 0.1 mm, and a numerical value obtained by multiplying this by 10 times. , And the measurement was performed under the conditions of a sample temperature of 25 ° C., a load of 100 g, and an entry time of 5 seconds.

<Wax (C)>
C1: Purban 1353 (manufactured by TWC, paraffin wax, DSC melting point: 62 ° C., Saybolt universal viscosity (120 ° C.): 37 seconds, penetration: 12.8 dmm / 25 ° C.)
C2: HNP-9 (Nippon Seiro Co., Ltd., paraffin wax, DSC melting point: 76 ° C, Saybolt universal viscosity (120 ° C): 44 seconds, penetration: 7.0 dmm / 25 ° C)

<Other wax (D)>
D1: High wax 220P (manufactured by Mitsui Chemicals, Inc., ethylene / propylene copolymer, DSC melting point: 110 ° C., melt viscosity (B type viscometer, 140 ° C.): 80 mPa · s, penetration: 13 dmm / 25 ° C.)
D2: High wax 220MP (manufactured by Mitsui Chemicals, oxidized ethylene / propylene copolymer, DSC melting point: 107 ° C, melt viscosity (B-type viscometer, 140 ° C): 80 mPa · s, penetration: 14 dmm / 25 ℃)
D3: High wax 1105A (manufactured by Mitsui Chemicals, acid-modified ethylene / propylene copolymer, DSC melting point: 104 ° C, melt viscosity (B-type viscometer, 140 ° C): 150 mPa · s, penetration: 6. 0dmm / 25 ° C)

<Tackifying resin (E)>
E1: Archon P-100 (Arakawa Chemical Industries, Ltd., alicyclic saturated hydrocarbon resin, DSC melting point: 54 ° C.)
E2: Licatac 4851 (Rosin-pentaerythritol ester, Arakawa Chemical Industries, DSC melting point: 69 ° C)

<Production method of hot melt coated product (lid material)>
Using a gravure coater, the hot melt composition obtained by the above method is coated on a substrate PE surface laminated in the order of PET (20 μm) / Al (aluminum foil, 15 μm) / PE (polyethylene, 20 μm) by: Coating was performed at a coating amount of 16 g / m ² to obtain a hot melt coated product. Table 2 shows the results of the following evaluations.

<Hot melt evaluation method>
<Viscosity>
The melt viscosity of the hot melt composition was measured according to JIS K6862. Using a B-type viscometer, the temperature was 160 ° C. and the rotor No. 3. The measurement was performed under the conditions of a rotation speed of 12 rpm and 30 seconds. In general, those having a viscosity of 5,000 mPa · s or less at 160 ° C. are excellent in workability, and those having a viscosity of 5,000 mPa · s or less are evaluated as ○: good, and those exceeding 5000 mPa · s are evaluated as x: poor.

<Opening strength (seal strength)>
After the lid material obtained by the above method was cut into a size of 100 mm x 100 mm, the size of the opening was heat-sealed and sealed at a gauge pressure of 0.3 MPa at 160 ° C for 0.5 seconds in a 71 mmΦ PET container. . The sample was allowed to stand in a thermo-hygrostat at a temperature of 23 ° C. and a humidity of 65% for 24 hours, and the measurement was carried out in the same chamber at a speed of 200 mm / min by 45 ° square peeling. The maximum load (N) at the time of opening was measured at five points for each package, and the average value was defined as the opening strength. Generally, if the opening strength is 10 to 15 N, it can be said that the easy-opening property is good.

<Sealing strength>
After cutting the lid material obtained by the above method for producing a hot melt coated product into a size of 100 mm × 100 mm, the opening size is 71Φ PET container at a gauge pressure of 0.3 MPa, 160 ° C. and 0.5 seconds. And heat sealed. The container was allowed to stand for 24 hours in a constant temperature / humidity room at a temperature of 23 ° C. and a humidity of 65%, and the pressure inside the container was increased at a rate of 13.3 kPa / 10 seconds in the same room. kPa) was measured at five points for each package, and the average value was taken as the sealing strength. In general, if the sealing strength is 18 kPa or more, it can be said that the material has sufficient sealing properties.

<Feeling of peeling>
After cutting the lid material obtained by the above method for producing a hot melt coated product into a size of 100 mm × 100 mm, heat sealing in a 71Φ PET container at a gauge pressure of 0.3 MPa, 160 ° C. and 0.5 seconds, Sealed. When left in a constant temperature and humidity room at a temperature of 23 ° C. and a humidity of 65% for 24 hours and peeled off the lid material by hand, the peeling feeling (with or without zipping) was as follows: Δ: good, Δ: acceptable, ×: bad The evaluation was made in three steps.

<Blocking resistance>
After the lid material obtained by the above method for producing a hot melt coated product is cut into a size of 50 mm × 50 mm, the lid material is overlaid on 10 sheets, and a load of 1 kg / cm ² is applied in a 50 ° C. atmosphere and left for 24 hours. I do. After that, it was left still for 1 hour in a constant temperature and humidity room at a temperature of 23 ° C. and a humidity of 65%, and the presence or absence of blocking when the lid material was peeled by hand was removed without any resistance (very good). : Peeling with resistance and sound (good) 3: Peeling with resistance and sound (good) 2: Peeling with resistance and sound (slightly bad) 1: Blocking and not peeling (bad) ) And 5).

As is evident from the results in Table 2, the results were not sufficient in the comparative examples, while the examples showed good results.

Claims (6)

Ethylene-unsaturated ester copolymer (A): 20 to 45% by weight, polyethylene wax grafted with styrene monomer (B): 3 to 45% by weight, and melting point at 40 ° C or higher and lower than 80 ° C, at 120 ° C Wax (C) having a Saybolt universal viscosity of 20 to 300 seconds: a hot melt composition containing 30 to 70% by weight, wherein the total of the wax (B) and the wax (C) is 50 to 80% by weight. object.
(However, the total of (A) to (C) is 100% by weight)   The hot melt composition according to claim 1, wherein the wax (B) is a polyethylene wax having styrene grafted in an amount of 20% by weight or more.   A lid comprising a hot melt layer comprising the hot melt composition according to claim 1 or 2 provided on one surface of a substrate on which at least two or more types selected from the group consisting of a resin sheet, paper, and an aluminum sheet are laminated. Wood.   The lid material according to claim 3, wherein the resin sheet is a sheet selected from the group consisting of a polyethylene sheet, a polypropylene sheet, a polyethylene terephthalate sheet, and a vapor-deposited sheet thereof.   An openable sealed container member set comprising a container and the lid according to claim 3. An openable sealed container, wherein an opening of the container is heat-sealed with the hot melt layer of the lid material according to claim 3 or 4.