JP3304580B2 - Manufacturing method of laminated paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing laminated paper. Specifically, an ionic (meth) acrylamide-based water-soluble or water-dispersible polymer (hereinafter, ionic (meth) acrylamide-based water-soluble or water-dispersible polymer is simply referred to as acrylamide-based water-soluble (Also referred to as a molecule), and a method for producing a laminated paper having excellent interlayer adhesion strength.

[0002]

2. Description of the Related Art Conventionally, in the production of laminated paper, an interlayer adhesive has been applied by spraying to the surface of a wet paper layer before lamination in order to improve the interlayer adhesive strength. An ungelatinized starch dispersion is mainly used as an interlayer adhesive. However, the adhesive strength of starch is weak, and a large amount of starch must be used in order to obtain sufficient interlayer adhesive strength. In addition, in addition to problems such as insufficient gelatinization in the drying process after lamination, and the water that has absorbed the starch during gelatinization causes blistering between layers, the addition amount due to clogging of the spray nozzle and sedimentation of the dispersion liquid. There is also a problem in terms of operation, such as run-out, and an environmental problem, such as the fact that the starch which is not fixed between the layers and falls out of the paper causes an increase in the COD of the wastewater.

[0003] Further, there has been proposed a method of solving the above-mentioned problems by using an acrylamide-based water-soluble polymer as an interlayer adhesive. In order to obtain a laminated paper having excellent interlayer strength using such an acrylamide-based water-soluble polymer, it is necessary to improve the fixing property between layers by increasing the molecular weight of the acrylamide-based water-soluble polymer. However, there is a problem that the spray liquid does not form a mist and cannot be uniformly applied because the viscosity increases with an increase in the molecular weight. On the other hand, there is a problem that the concentration of the spray liquid must be reduced in order to apply uniformly, and an acrylamide-based water-soluble polymer that can produce a laminated paper having excellent interlayer strength with good workability has not yet been obtained. Not been.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing an interlayer adhesive by using a water-soluble acrylamide polymer in a low addition amount, which has good fixability between layers and is suitable for spray coating. An object of the present invention is to provide a method for producing a laminated paper having excellent adhesive strength with good workability.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems of the prior art, and as a result, have found that an acrylamide-based water-soluble polymer obtained by copolymerizing a crosslinkable monomer is used as an interlayer. When used as an adhesive, since the water-soluble polymer has a three-dimensional network structure, it can be used with low viscosity even when the molecular weight is increased to improve the fixability between layers. And completed the present invention.

That is, the present invention relates to a method for producing a laminated paper having two or more layers by applying an interlayer adhesive to the surface of the wet paper layer before the lamination and then laminating the laminated paper. as, it is those using a (meth) acrylamide, an ionic water-soluble or water-dispersible polymer obtained by copolymerizing an ionic monomer and a crosslinking monomer
And apply an interlayer adhesive to the surface of the wet paper layer before lamination.
When woven, the surface of the wet paper layer has a low moisture content.
The present invention relates to a method for producing a laminated paper, which comprises applying an interlayer adhesive to the surface of either wet paper layer . Again
Akira applied an interlayer adhesive to the surface of the wet paper layer before laminating, and then laminated the laminated paper to produce two or more layers of laminated paper. been made to use an ionic monomer, the ionic water-soluble or water-dispersible polymer obtained by copolymerizing a hydrophobic monomer and a crosslinkable monomer, paper making if
When applying an interlayer adhesive to the surface of the wet paper layer before
Then, the surface of the wet paper layer having the lower moisture content
The present invention relates to a method for producing a laminated paper, which comprises applying an interlayer adhesive to the surface of a wet paper layer . Also, the present invention provides
An interlayer adhesive was applied to the surface of the wet paper layer before bonding
Later, it is laminated to produce two or more layers of laminated paper.
(Meth) acrylamide as an interlayer adhesive
Copolymerized with ionic monomers and crosslinkable monomers
Ionic water-soluble or water-dispersible polymer
To be used on the surface of the wet paper layer before lamination
When applying an interlayer adhesive to the surface of the wet paper layer,
Of the wet paper layer on the opposite side to the dewatering direction of the paper machine.
Coating characterized by applying an interlayer adhesive to the surface
The present invention relates to a method for manufacturing a paper. Also, the present invention provides
After applying the interlayer adhesive to the surface of the wet paper layer,
To produce two or more layers of laminated paper
(Meth) acrylamide, io
Monomer, hydrophobic monomer and crosslinkable monomer
Ionic high water solubility or water dispersibility obtained by copolymerization
Uses molecules, wet paper layer before lamination
When the interlayer adhesive is applied to the surface of
Wet on the opposite side to the paper machine dewatering direction
Characterized by applying an interlayer adhesive on the surface of the paper layer
The present invention relates to a method for producing laminated paper.

In the present invention, (meth)
An acrylamide-based water-soluble polymer obtained by copolymerizing acrylamide, an ionic monomer and a crosslinkable monomer is used.

In the present invention, (meth) acrylamide means acrylamide or methacrylamide,
These can be used alone or in combination, but acrylamide is preferably used alone in terms of economy.

The ionic monomer includes an anionic monomer and a cationic monomer. Examples of the anionic monomer include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, muconic acid, and citraconic acid; vinylsulfonic acid, styrenesulfonic acid, and 2-carboxylic acid.
Organic sulfonic acids such as acrylamido-2-methylpropanesulfonic acid; and sodium salts and potassium salts of these various organic acids. Examples of the cationic monomer include dimethylaminoethyl (meth)
Vinyl monomers having a tertiary amino group such as acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, and the like of inorganic or organic acids such as hydrochloric acid, sulfuric acid, and acetic acid. And salts or vinyl monomers containing a quaternary ammonium salt obtained by reacting the tertiary amino group-containing vinyl monomer with a quaternizing agent such as methyl chloride, benzyl chloride, dimethyl sulfate or epichlorohydrin. One of these ionic monomers can be used alone or two or more of them can be used in combination, and imparts anionic, cationic or amphoteric ionicity to the acrylamide-based water-soluble polymer.

Examples of the crosslinkable monomer include di (meth) acrylates such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and triethylene glycol di (meth) acrylate, methylene bis (meth) acrylamide, ethylene Bis (meth) acrylamides such as bis (meth) acrylamide and hexamethylenebis (meth) acrylamide, divinyl esters such as divinyl adipate and divinyl sebacate, epoxy acrylates, urethane acrylates, N-methylol acrylamide, diallylamine, Bifunctional monomers such as diallyldimethylammonium, diallylphthalate, diallylchlorendate and divinylbenzene, 1,3,5-triacryloylhexahydro-S- Trifunctional monomers such as riadine, triallyl isocyanurate, triallylamine, triallyl trimellitate, N, N-diallylacrylamide, tetramethylolmethanetetraacrylate, tetraallyl pyromellitate, N, N, N ', N' And 4-functional monomers such as tetraallyl-1,4-diaminobutane, tetraallylamine salt, and tetraallyloxyethane.

[0011] The crosslinkable monomer of the present invention includes:
Vinyl monomers having a chain transfer substituent can also be used. Any vinyl monomer having a chain transfer functional group can be used without particular limitation as long as it has a chain transfer functional group. For example, vinyl monomers having an allyl group, a polyalkylene glycol group, an N-substituted amide group, etc. and itacone Acid diester and the like. Allyl group-containing vinyl monomers include allyl (meth)
Acrylate, N-allyl (meth) acrylamide,
N, N-diallyl (meth) acrylamide, allylamine and the like can be mentioned. The polyalkylene glycol group may have at least two repeating units of an oxyalkylene group, and generally up to about 10 repeating units can be used. Specific examples include diethylene glycol mono (meth) acrylate,
Polyethylene glycol mono (meth) acrylates such as triethylene glycol mono (meth) acrylate and tetraethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and methoxy polyethylene glycol mono (meth) as described above
Examples include acrylate, polytrimethylene glycol mono (meth) acrylate, polytetramethylene glycol mono (meth) acrylate, and polyethylene glycol propylene glycol mono (meth) acrylate. Examples of the vinyl monomer having an N-substituted amide group include dimethylacrylamide, diacetone acrylamide, isopropylacrylamide, 2-acrylamido-2-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanecarboxylic acid, And alkyl esters of the formulas 1 to 4. Examples of the itaconic diester include dialkyl itaconates having 1 to 4 carbon atoms. In the present invention, any of the crosslinkable monomers can be used, but it is preferable to use a vinyl monomer having a chain transfer substituent. Further, one kind of the crosslinkable monomer may be used, or two or more kinds thereof may be used.

The amount of the (meth) acrylamide, ionic monomer and crosslinkable monomer used is such that the acrylamide-based water-soluble polymer obtained by copolymerizing them has a high molecular weight and low viscosity and is used as an interlayer adhesive. In this case, the fixing rate between layers is good, and the spray performance is excellent,
Decisions must be made with due consideration to ensure stable operation.

That is, the amount of (meth) acrylamide used is usually 50 to 99.9 based on the total moles of the monomers.
It is about mol%, preferably 60 to 99.5 mol%.

When an anionic acrylamide-based water-soluble polymer is obtained, the amount of the ionic monomer used is usually about 0.1 to 30 mol%, preferably about 0.1 to 30 mol%, based on the total mol of the monomers. Is used in an amount of 0.2 to 15 mol%, and when a cationic acrylamide-based water-soluble polymer is obtained, the cationic monomer is usually used in an amount of about 0.1 to 30 mol%, preferably 0.1 to 30 mol%, based on the total mol of the monomer. Is used in an amount of 0.2 to 15 mol%. When an amphoteric acrylamide-based water-soluble polymer is obtained, the cationic monomer is usually used in an amount of 0.1 to 20 with respect to the total mole of the monomer.
The anionic monomer is used in an amount of about 0.1 mol%, preferably 0.2 to 15 mol%, usually 0.1 mol
About 20 mol%, preferably 0.2 to 15 mol%. When the proportion of the ionic monomer is less than the above range, the proportion of the ionic component is small and the fixability to the surface of the wet paper layer is deteriorated. When the proportion exceeds the above range, the proportion of the (meth) acrylamide is small. In this case, a laminated paper having a sufficient interlayer strength cannot be obtained.

The amount of the crosslinking monomer is usually about 0.01 to 10 mol%, preferably 0.01 to 5 mol%, based on the total mol of the monomers. When the amount is less than 0.01 mol%, a sufficient three-dimensional network structure is not obtained, and a low-viscosity, high-molecular-weight acrylamide-based water-soluble polymer cannot be obtained. If it exceeds 10 mol%, the obtained copolymer is insoluble in water, which is not preferable.

In the present invention, acrylonitrile, vinyl acetate, styrene, α
-The fixing property can be further improved by using a hydrophobic monomer such as an olefin. The amount of the hydrophobic monomer to be used is generally about 40 mol% or less, preferably 35 mol% or less, based on the total mol of the monomers. 40
If it exceeds mol%, the copolymer becomes insoluble in water, which is not preferable.

As a method for obtaining the acrylamide-based water-soluble polymer by copolymerizing the above-mentioned monomer, various conventionally known methods can be adopted. For example, the above-described monomers and water are charged into a predetermined reaction vessel, and potassium persulfate, a persulfate such as ammonium persulfate, or a redox polymerization initiator in the form of a combination thereof with a reducing agent such as sodium bisulfite. An ordinary acrylamide-based water-soluble polymer can be obtained by adding a usual radical polymerization initiator and heating under stirring.

Since the interlayer adhesive of the present invention comprising the acrylamide-based water-soluble polymer thus obtained uses a crosslinkable monomer, it can be used as a conventional linear acrylamide-based water-soluble polymer. In comparison, it has a relatively low viscosity while having a high molecular weight. The weight-average molecular weight of the acrylamide-based water-soluble polymer of the present invention is usually about 1.5 to 10 million, and the viscosity is 15% by weight of solid content.
It is usually less than about 10,000 cps (25 ° C)
Preferably, the properties are about 5000 cps (25 ° C.) or less.

In the present invention, the interlayer adhesive comprising the acrylamide-based water-soluble polymer is applied to the surface of the wet paper layer before lamination, then laminated by a conventional method, dehydrated and dried. Produce two or more layers of laminated paper.

The application of the interlayer adhesive is generally performed by spraying, and the interlayer adhesive is usually used at a concentration of about 0.1 to 1.5% by weight and a viscosity of about 3 to 50 cps (25 ° C.). . Also, the interlayer adhesive is usually based on the pulp solids content.
It may be applied at a usage ratio of 0.05 to 1.5% by weight (solid content) .

The interlayer adhesive comprising the acrylamide-based water-soluble polymer is selected from starch, which has been conventionally used as an interlayer adhesive, to the extent that the object of the present invention is not impaired.
It can also be used in combination with natural powdery resins such as modified starch, casein, galactomannan and the like.

In the method for producing a laminated paper according to the present invention, when an interlayer adhesive is applied to the surface of the wet paper layer before the lamination, the water content of the surface of the wet paper layer is reduced. By applying an interlayer adhesive to the surface of the smaller wet paper layer, the interlayer adhesive strength of the laminated paper can be further improved. That is, since the amount of moisture on the surface of the wet paper layer is different from each other, if the surface of the wet paper layer to which the interlayer adhesive is applied is selected as in the above-described coating method, the interlayer adhesion that flows out of the paper together with the moisture during the paper making process is selected. As a result, the ratio of fixing of the interlayer adhesive between the layers is increased, and the interlayer adhesive strength of the laminated paper can be improved.

Further, the surface of the wet paper layer before the lamination is
When the interlayer adhesive is applied, by further applying the interlayer adhesive to the surface of the wet paper layer on the opposite side of the surface of the wet paper layer with respect to the dewatering direction of the paper machine, further papermaking is performed. The interlayer adhesive strength of the laminated paper can also be improved.
In other words, if the surface of the wet paper layer to which the interlayer adhesive is applied is selected as in the above-described application method, the interlayer adhesive flowing out of the paper together with moisture during dehydration after laminating can be minimized. As a result, the fixing ratio of the interlayer adhesive between the layers is increased, and the interlayer adhesive strength of the laminated paper can be improved.

[0024]

According to the present invention, a laminated paper having high interlayer adhesive strength can be provided. The interlayer adhesive used in the present invention has low viscosity and excellent workability.

[0025]

The present invention will now be described more specifically with reference to examples and comparative examples. All parts and percentages are based on weight.

(Preparation of Acrylamide-Based Water-Soluble Polymer) Production Example 1 Ion-exchanged water 475 was charged into a flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet pipe, a dropping funnel for monomer and a dropping funnel for catalyst. And heated to 90 ° C. with stirring. Next, 287 parts of acrylamide, 5 parts of itaconic acid, 6 parts of dimethylaminoethyl methacrylate, and 0.1 part of methylenebisacrylamide were added to the dropping funnel for monomer.
05 parts and 558 parts of ion-exchanged water were charged, and the pH was adjusted to 4 to 5 using sulfuric acid. The catalyst dropping funnel was charged with 1.4 parts of ammonium persulfate and 100 parts of ion-exchanged water as a polymerization initiator. After removing all the oxygen in the reaction system through nitrogen gas, the catalyst was continuously added dropwise for 200 minutes, while the monomer was added dropwise for 120 minutes, and the polymerization was carried out under reflux.
%, Viscosity 2800 cps (25 ° C.), average molecular weight 310
An amphoteric acrylamide-based water-soluble polymer was obtained.

Production Example 2 Into the same reactor as in Example 1, 499 parts of ion-exchanged water was charged and heated to 90 ° C. with stirring. Next, 267 parts of acrylamide and 26 parts of itaconic acid were added to the dropping funnel for monomer.
Parts, dimethylacrylamide 1.2 parts and ion-exchanged water 587 parts. The catalyst dropping funnel includes:
As a polymerization initiator, 1.2 parts of ammonium persulfate and 100 parts of ion-exchanged water were charged. After removing all the oxygen in the reaction system through nitrogen gas, the catalyst is continuously 200
The monomer was added dropwise for 120 minutes, and the monomer was added dropwise for 120 minutes to conduct polymerization under reflux. The anionic acrylamide-based water-soluble polymer having a solid content of 15%, a viscosity of 2100 cps (25 ° C.) and an average molecular weight of 2.8 million was used. The molecule was obtained.

Production Example 3 Into the same reactor as in Example 1, 510 parts of ion-exchanged water was charged and heated to 90 ° C. with stirring. Next, 276 parts of acrylamide, 24 parts of dimethylaminopropyl methacrylamide, 0.4 part of triallylamine and 600 parts of ion-exchanged water were charged into the dropping funnel for monomer, and the pH was adjusted to 4 to 5 with sulfuric acid. In addition, ammonium persulfate as a polymerization initiator was added to the dropping funnel for catalyst.
4 parts and 100 parts of ion-exchanged water were charged. After removing all oxygen in the reaction system through nitrogen gas, the catalyst was dropped continuously over 200 minutes, while the monomer was
The polymerization was carried out under reflux for 15 minutes, the solid content was 15%, the viscosity was 2400 cps (25 ° C.), and the average molecular weight was 3
One million cationic acrylamide-based water-soluble polymers were obtained.

Production Example 4 474 parts of ion-exchanged water were placed in the same reactor as in Example 1, and heated to 90 ° C. with stirring. Next, 199 parts of acrylamide and 5 parts of itaconic acid were added to the dropping funnel for monomer.
Parts, dimethylaminopropyl methacrylamide 12 parts,
1. 66 parts of acrylonitrile, dimethylacrylamide
After charging 1 part and 558 parts of ion-exchanged water, the pH was adjusted to 4 to 5 using sulfuric acid. Further, 1.7 parts of ammonium persulfate and 100 parts of ion-exchanged water were charged as a polymerization initiator in the dropping funnel for the catalyst. After removing all the oxygen in the reaction system through nitrogen gas, the catalyst was continuously added dropwise for 200 minutes, while the monomer was added dropwise for 120 minutes, and the polymerization was carried out under reflux.
%, Viscosity 1500 cps (25 ° C.), average molecular weight 240
An amphoteric acrylamide-based water-soluble polymer was obtained.

Production Example 5 Into the same reactor as in Example 1, 469 parts of ion-exchanged water was charged and heated to 90 ° C. with stirring. Next, 213 parts of acrylamide and itaconic acid 26 were added to the dropping funnel for monomer.
Parts, 40 parts of acrylonitrile, 1.2 parts of dimethylacrylamide, and 500 parts of ion-exchanged water. Further, 1.7 parts of ammonium persulfate and 100 parts of ion-exchanged water were charged as a polymerization initiator in the dropping funnel for the catalyst. After removing all the oxygen in the reaction system through nitrogen gas, the catalyst was continuously added dropwise over 200 minutes, while the monomer was added dropwise over 120 minutes, and the polymerization was carried out under reflux to obtain a solid content of 15%. , Viscosity 2600 cps (25
C) and an anionic acrylamide-based water-soluble polymer having an average molecular weight of 1.9 million was obtained.

Production Example 6 Into the same reactor as in Example 1, 519 parts of ion-exchanged water were charged and heated to 90 ° C. with stirring. Next, 289 parts of acrylamide and itaconic acid 5 were added to the dropping funnel for monomer.
Parts, 6 parts of dimethylaminoethyl methacrylate, 4 parts of styrene, 1.2 parts of dimethylacrylamide and 558 parts of ion-exchanged water.
Adjusted to 5. Further, 1.7 parts of ammonium persulfate and 100 parts of ion-exchanged water were charged as a polymerization initiator in the dropping funnel for the catalyst. After removing all the oxygen in the reaction system through nitrogen gas, the catalyst was dropped continuously over 200 minutes, while the monomer was dropped over 120 minutes.
The polymerization was carried out under reflux, and the solid content was 20% and the viscosity was 1020.
An amphoteric acrylamide-based water-soluble polymer having 0 cps (25 ° C.) and an average molecular weight of 1.95 million was obtained.

Production Example 7 Acrylamide 184 was placed in the same reactor as in Example 1.
Parts, 16 parts of dimethylaminopropyl methacrylamide and 1277 parts of ion-exchanged water, and the pH was adjusted to 4 to 5 with sulfuric acid. The mixture was heated to 50 ° C. with stirring, 0.18 parts of ammonium persulfate and 0.04 part of sodium bisulfite were added as polymerization initiators, and polymerization was carried out under reflux for 180 minutes. %, A viscosity of 9000 cps (25 ° C.), and a cationic acrylamide-based water-soluble polymer having an average molecular weight of 1.2 million.

Production Example 8 In the same reactor as in Example 1, 11 parts of methacrylic acid,
16 parts of an 8% aqueous sodium hydroxide solution and 500 parts of ion-exchanged water were charged and kept at 70 ° C. for 30 minutes. 60 ° C
After cooling, 200 parts of acrylamide and 68 parts of ion-exchanged water
0 parts, 5 parts of isopropyl alcohol and 6 parts of sulfuric acid at 60 ° C., and 0.6 part of potassium persulfate were further added. After polymerization was performed for 150 minutes under reflux, ion-exchanged water was added, and the solid content concentration was 7%. An anionic acrylamide-based water-soluble polymer having 5000 cps (25 ° C.) and an average molecular weight of 1,000,000 was obtained.

Examples 1 to 6 and Comparative Examples 1 and 2 (Manufacture of laminated paper) Used corrugated paper was beaten with a Niagara beater to obtain Canadian Standard Freeness (CSF).
After adding 2% of the sulfuric acid band to the pulp adjusted to 420 ml, 0.9% of the pulp with a commercially available anionic acrylamide-based paper strength agent was added thereto, followed by stirring and mixing uniformly. The obtained pulp slurry was diluted to 0.5%, and wet paper A having a water content of 86% and wet paper B having a water content of 96% were diluted with a hand paper tester.
(Dry basis weight 100 g / m 2) was prepared. On one side of wet paper B, acrylamide-based water various acrylamide-based water-soluble polymer obtained in Production Example 1-8 shown in Table 1 a solution diluted to 0.7% with ion-exchanged water, relative to the pulp solids High
After spray application at a ratio where the solid content of the molecule is 0.7%, the application surfaces of the wet paper web A and the wet paper web B are overlapped, and one
The mixture was suction-dehydrated at 50 mmHg for 1 minute and dried to obtain a laminated paper.

Example 7 The procedure of Example 5 was repeated, except that the acrylamide-based water-soluble polymer obtained in Production Example 5 was applied to one side of the wet paper web A, and suction dehydration was performed from the direction of the wet paper web A. In the same manner as in Example 5, a laminated paper was obtained.

Example 8 A laminated paper was obtained in the same manner as in Example 5, except that suction dehydration was performed in the direction of the wet paper web A.

Example 9 A laminated paper was obtained in the same manner as in Example 5 except that the acrylamide-based water-soluble polymer obtained in Production Example 5 was applied to one surface of wet paper A. Was.

Example 10 A laminated paper was obtained in the same manner as in Example 4 except that the acrylamide-based water-soluble polymer obtained in Production Example 4 was applied to one side of wet paper A. Was.

Examples 11 to 16 and Comparative Examples 3 to 4 (Production of laminated paper) BKP was beaten with a Niagara beater to obtain Canadian Standard Freeness (CSF) 550.
the pulp was adjusted to ml, and stirred and uniformly mixed by adding commercially available amphoteric acrylamide paper strength agent to 0.9% pulp. The obtained pulp slurry (pH 6.8) was added to 0.1 %.
It was diluted to 5% and wet paper A with a water content of 86% and wet paper B with a water content of 96% (dry basis weight 100 g / m 2) using a hand paper tester.
) Was prepared. Production Example 1 shown in Table 1 on one side of wet paper B
Of acrylamide-based water-soluble polymer diluted to 0.7% with ion-exchanged water obtained in Steps 8 to 8 so that the acrylamide-based water -soluble polymer has a solid content of 0.7% with respect to the pulp solid content. Then, the coated surfaces of the wet paper web A and the wet paper web B were overlapped, suction-dehydrated at 150 mmHg for 1 minute in the direction of the wet paper web B, and dried to obtain a laminated paper.

Example 17 The procedure of Example 15 was repeated except that the acrylamide-based water-soluble polymer obtained in Production Example 5 was applied to one side of the wet paper web A, and the suction dehydration was performed from the direction of the wet paper web A. In the same manner as in Example 15, a laminated paper was obtained.

Example 18 A laminated paper was obtained in the same manner as in Example 15, except that suction dehydration was performed from the direction of the wet paper web A.

Example 19 A laminated paper was obtained in the same manner as in Example 15 except that the acrylamide-based water-soluble polymer obtained in Production Example 5 was applied to one side of wet paper A. Was.

Example 20 A laminated paper was obtained in the same manner as in Example 14 except that the acrylamide-based water-soluble polymer obtained in Production Example 4 was applied to one surface of wet paper A. Was.

(Measurement of Interlaminar Adhesive Strength) The obtained laminated paper was conditioned for 24 hours and then subjected to J-TAPPI paper pulp test method No. The interlayer adhesive strength (T-peel strength (g / in)) was measured according to 19-77. The results are shown in Table 1 or Table 2.

(Fixing rate) The nitrogen content of the obtained laminated paper was measured, and the fixing rate between layers was calculated. Fixing rate (%) = (B−C) / A × 100. A: The measured value of nitrogen in the applied acrylamide-based water-soluble polymer, B: The measured value of nitrogen in the paper obtained by applying the acrylamide-based water-soluble polymer as an interlayer adhesive, and C: the same pulp as B Measurement of nitrogen content of paper laminated without using an interlayer adhesive. The results are shown in Table 1 or Table 2.

[0046]

[Table 1]

[0047]

[Table 2]

From the results shown in Tables 1 and 2, according to the interlayer adhesive using the acrylamide-based water-soluble polymer of the present invention, the conventional interlayer adhesive using the same ionic acrylamide-based water-soluble polymer can be used. It is recognized that a laminated paper having excellent interlayer adhesion strength can be obtained. Further, according to the method of applying the present invention, it is recognized that more excellent combination papers interlayer adhesion strength Ru <br/> to have a can be obtained.

Continuation of the front page (56) References JP-A-5-272092 (JP, A) JP-A-5-263393 (JP, A) JP-A-5-156597 (JP, A) JP-A-5-140896 (JP) JP-A-5-140893 (JP, A) JP-A-5-140892 (JP, A) JP-A-5-125692 (JP, A) JP-A-5-86597 (JP, A) JP-A-4-46915 (JP, A) JP-A-4-11095 (JP, A) JP-A-3-227482 (JP, A) JP-A-2-139494 (JP, A) JP-A-2-61197 (JP, A A) JP-A-62-104998 (JP, A) JP-A-63-227896 (JP, A) JP-A-48-10306 (JP, A) JP-A-63-21999 (JP, A) JP-A-62 -257498 (JP, A) JP-A-5-230792 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D21H 11/00-27/42 D21F 1/00-13/12

Claims (7)

(57) [Claims] 1. An interlayer adhesive is applied to the surface of a wet paper layer before laminating, and then laminated to produce two or more layers of laminated paper. ) acrylamide been made to use an ionic water-soluble or water-dispersible polymer obtained by copolymerizing an ionic monomer and a crosslinkable monomer, prior to mating paper making
When applying an interlayer adhesive to the surface of the wet paper layer,
Table of the wet paper layer with the lower moisture content on the surface of the paper layer
A method for producing a laminated paper, comprising applying an interlayer adhesive to a surface . 2. An interlayer adhesive is applied to the surface of the wet paper layer before laminating, and then laminated to produce two or more layers of laminated paper. ) be one which uses acrylamide, ionic monomers, the ionic water-soluble or water-dispersible polymer obtained by copolymerizing a hydrophobic monomer and a crosslinking monomer
And apply an interlayer adhesive to the surface of the wet paper layer before lamination.
When woven, the surface of the wet paper layer has a low moisture content.
A method for producing a laminated paper, comprising applying an interlayer adhesive to the surface of either wet paper layer . 3. The method according to claim 1, wherein the surface of the wet paper layer before laminating is coated with an interlayer.
After applying the adhesive, make two or more layers
In the production of laminated paper, a
T) Acrylamide, ionic monomer and crosslinkable monomer
Ionic water-soluble or water obtained by copolymerizing nomers
The use of a dispersible polymer, and prior to lamination
When applying an interlayer adhesive to the surface of the wet paper layer,
On the surface of the paper layer, opposite to the direction of dewatering of the paper machine
A special feature is to apply an interlayer adhesive to the surface of a wet paper layer.
Paper making combined paper manufacturing method of a butterfly. 4. The method according to claim 1, wherein the surface of the wet paper layer before laminating is coated with an interlayer.
After applying the adhesive, make two or more layers
In the production of laminated paper, a
TA) acrylamide, ionic monomers, hydrophobic monomers
Obtained by copolymerizing monomer and crosslinkable monomer
Using water-soluble or water-dispersible polymers
And apply an interlayer adhesive to the surface of the wet paper layer before lamination.
When woven, dewatering of the paper machine on the surface of the wet paper layer
Apply an interlayer adhesive to the surface of the wet paper layer on the opposite side
A method for producing a laminated paper, characterized by applying the following . 5. The method according to claim 1, wherein the interlayer adhesive is an anionic water-soluble or
5. The method for producing a laminated paper according to claim 1, wherein is a water-dispersible polymer . 6. The method according to claim 1, wherein the interlayer adhesive is a cationic water-soluble or
5. The method for producing a laminated paper according to claim 1, wherein is a water-dispersible polymer . 7. The interlayer adhesive is amphoteric water-soluble or water-soluble.
The method for producing a laminated paper according to any one of claims 1 to 4 , which is a dispersible polymer .