JPH10114851A - Moistureproofing composition, moistureproof paper and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moistureproofing composition which can give moistureproof paper excellent in resistance to mechanical damage, blocking resistance, moistureproofness, the capability of being easily dissociated and bendability by mixing a self-crosslinking synthetic resin emulsion with a wax emulsion. SOLUTION: This composition comprises 100 pts.wt. (in terms of the solid matter) self-crosslinking synthetic resin emulsion (A) obtained by polymerizing 99.5-85 pts.wt. polymerizable unsaturated monomer with 0.5-15 pts.wt. crosslinking unsaturated monomer copolymerizable therewith and 1-100 pts.wt. (in terms of the solid matter) wax emulsion (B). Component A is desirably one which has at least one type of functional-group-containing unsaturated monomer and is crosslinked by heating as a result of the reaction of the functional groups or one having a crosslinked structure formed by crosslinking through a polyfunctional crosslinking unsaturated monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-proof paper, particularly a cardboard moisture-proof paper, which is hardly damaged by mechanical damage in a box-making process and in actual use (hereinafter also referred to as "mechanical damage resistance"). The present invention provides a moisture-proof composition having excellent disintegration, blocking resistance, and bendability, and a cardboard coated with the composition. It is intended to provide a composition and a method for producing a moisture-proof paper provided with the composition.

[0002]

2. Description of the Related Art Conventionally, high-quality paper, kraft paper, carton paper, corrugated paper, various types of coated paper, etc., and paper products such as high-quality paper and coated paper have been conventionally used. For the packaging, wrapping paper is used in which a polyolefin polymer compound such as polyethylene or polypropylene is applied to paper, laminated or internally added to prevent moisture absorption of the product to impart moisture resistance and water resistance. In addition, for heavy paper base paper such as cement bags, salt bags, feed bags, garbage bags, etc., moisture-proofing and strength are required to transport heavy objects while preventing moisture absorption and water absorption of the contents after bag making and bagging. In addition, a polyolefin laminated paper (hereinafter abbreviated as polylaminate paper) obtained by laminating polyethylene, polypropylene or the like on kraft paper is overlapped with kraft paper and used as a multilayer bag.

[0003] Even if these poly-laminate papers are collected to be reused as used paper after use, they are not sufficiently disintegrated in water and cannot be reused as used paper, which poses a problem in terms of recycling. Also, used poly-laminate paper requires a burden for the user even when discarded, and it is difficult to treat the waste in terms of environmental pollution due to incineration and landfill.

[0004] Attempts to disintegrate used moisture-proof wrapping paper with water and reuse it as a raw material for paper are also known.

For example, JP-A-53-41511 discloses a method for producing a moisture-proof wrapping paper using an aqueous emulsion comprising a synthetic rubber-based latex and a wax emulsion. This method is used when manufacturing moisture-proof wrapping paper.
By performing high-temperature drying, it is intended to eliminate a decrease in moisture resistance and a decrease in moisture resistance due to bending during use of the product. However, this method provides a very high degree of moisture resistance, but is still insufficient. In addition, it is necessary to increase the amount of the moisture-proofing agent, and the resulting processed paper becomes slippery or mechanically damaged.
In addition, there are many new problems such as the tendency of processed paper to cause blocking.

JP-A-56-148997 discloses that a synthetic hydrocarbon resin and wax, a styrene-maleic acid copolymer and a surfactant are used and dispersed in water in the presence of at least an equivalent of saponified alkali. A composition for moisture-proofing paper comprising a mixture with an emulsion obtained by the method is disclosed. It is said that the moisture-proof paper produced by applying this composition to paper and drying is excellent in moisture-proof property, friction coefficient, blocking resistance, folding property and recyclability.
However, there is a drawback that moisture-proof paper is liable to be blocked when the amount of coating is increased for the purpose of enhancing the moisture-proof property, in addition to being a factor of lowering the moisture-proof property because it is susceptible to mechanical damage.

[0007] JP-A-3-279492 discloses that in order to solve the problem of blocking, even if the surface of the paper is coated with a relatively small amount of a coating solution with a low concentration, a sufficient moisture-proof effect is obtained. Moreover, a coating resin composition that is hardly subject to mechanical damage and hardly causes a blocking phenomenon is disclosed. The resin composition comprises α · β selected from the group consisting of alkyl (meth) acrylates and aromatic unsaturated monomers.
An aqueous dispersion of a synthetic resin obtained by emulsion polymerization of a monomer compound comprising a monoethylenically unsaturated monomer and acrylamide and / or methacrylamide is mixed with a wax emulsion to form a composition, This is one in which the secondary transition temperature of the synthetic resin is increased by using a high secondary transition temperature. Processed paper produced by applying such a composition to paper such as kraft paper has excellent blocking resistance, but the effect on foldability is unknown. In addition, in the case of producing a box using the processed paper, it is impossible to bond or adhere with an emulsion-based paste or an aqueous-based paste, and it was impossible to produce a box. In addition, the printability on the coated surface was poor due to bleeding.

[0008]

SUMMARY OF THE INVENTION In view of the above situation, the present inventors have considered blocking resistance, mechanical damage resistance, and adhesiveness (bonding and bonding using emulsion-based or aqueous-based paste). As a result of intensive studies to solve the problems of the prior art such as printability, a self-crosslinkable synthetic resin emulsion [emulsion (A)] and a wax-based emulsion [emulsion (W)] were blended. Moisture-proof coating agent having excellent performance in mechanical damage resistance, blocking resistance, moisture-proof property, easy disintegration, and bendability by applying a moisture-proof composition to base paper, and a method for producing cardboard provided with the same. Further, a moisture-proofing agent having good adhesiveness of the water-based adhesive and excellent printability, a moisture-proof paper provided with the same, and a method for producing the same have been completed.

That is, the present invention provides a polymerizable unsaturated monomer
99.5 to 85 parts by weight, and a self-crosslinkable synthetic resin emulsion [emulsion (A)] obtained by polymerizing 0.5 to 15 parts by weight of a crosslinkable unsaturated monomer copolymerizable therewith, and a wax-based emulsion [ Emulsion (W)] with respect to 100 parts by weight (solid content) of the emulsion (A) in a ratio of 1 to 100 parts by weight (solid content) of the wax emulsion (W).

Further, the present invention provides an emulsion (A) comprising:
Having one or more crosslinkable unsaturated monomers having a functional group,
The composition for moisture-proof processing, wherein the functional groups react with each other by heating and crosslink with each other, or have a crosslinked structure in the emulsion by a polyfunctional crosslinkable unsaturated monomer. .

[0011] The present invention also provides the composition for moisture-proof treatment as described above, wherein the wax contained in the wax emulsion (W) is at least one selected from the group consisting of polyolefin wax, paraffin wax and natural vegetable wax. About things.

The present invention also relates to a method for producing a moisture-proof paper, which comprises applying the above-mentioned composition for moisture-proof processing to a base paper as a moisture-proof layer, followed by drying and / or crosslinking.

The present invention also relates to a moisture-proof paper having a moisture-proof layer on a base paper, wherein the moisture-proof layer is provided with the above-mentioned composition for moisture-proof processing.

Further, the present invention relates to a packaging material using a moisture-proof paper having a moisture-proof layer on a base paper, wherein the moisture-proof layer is provided with the above composition for moisture-proof processing.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The self-crosslinkable synthetic resin emulsion used in the present invention is obtained by polymerizing 99.5 to 85 parts by weight of a polymerizable unsaturated monomer and 0.5 to 15 parts by weight of a crosslinkable unsaturated monomer copolymerizable therewith. It contains the obtained polymer. In the present invention, in particular, the self-crosslinkable synthetic resin emulsion has one or more crosslinkable unsaturated monomers having a functional group, and the functional groups react with each other by heating to crosslink. Or those having a crosslinked structure in the emulsion by a polyfunctional crosslinkable unsaturated monomer are preferred.

As the polymerizable unsaturated monomer, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, n-
Amyl (meth) acrylate, iso-amyl (meth) acrylate, n-hexyl (meth) acrylate, 2-
Such as ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, and benzyl (meth) acrylate; (Meth) acrylates; vinyl acetate,
Vinyl esters such as vinyl propionate; styrene,
Aromatic vinyls such as vinyltoluene, 2-methylstyrene, t-butylstyrene, chlorostyrene, vinylanisole and vinylnaphthalene; (meth) acrylamide;
Amides such as n-monoethyl (meth) acrylamide, dimethyl (meth) acrylamide, t-butyl (meth) acrylamide, diacetone (meth) acrylamide;
(Meth) acrylonitrile, ethylene, propylene, vinyl chloride, vinylidene chloride, butadiene, chloroprene and the like. Among these, styrene, butadiene, vinylidene chloride, alkyl acrylate, alkyl methacrylate, vinyl acetate, ethylene,
Acrylonitrile and the like are preferably used.

As the copolymerizable crosslinkable unsaturated polymer, one or more kinds of crosslinkable unsaturated monomers having a functional group, which have the property of reacting with each other by heating to crosslink, or A polyfunctional crosslinkable unsaturated monomer having a property of having a crosslink structure in the emulsion is preferred.

The one or more types of crosslinkable unsaturated monomers having a functional group, which have the property that the functional groups react with each other upon heating and crosslink, include (1) a crosslinkable unsaturated monomer having a methylol group. A cross-linkable unsaturated monomer capable of cross-linking with a methylol group, (2) a cross-linkable unsaturated monomer having an epoxy group, and a cross-linkable unsaturated monomer capable of cross-linking with an epoxy group, (3) a crosslinkable unsaturated monomer having a carboxyl group, a crosslinkable unsaturated monomer capable of undergoing a crosslink reaction with a carboxyl group, (4) a crosslinkable unsaturated monomer having a hydroxyl group, and a hydroxyl group. Examples include a crosslinkable unsaturated monomer capable of performing a crosslink reaction, (5) a crosslinkable unsaturated monomer having an alkoxysilyl group, and a crosslinkable unsaturated monomer capable of performing a crosslink reaction with an alkoxysilyl group.

(1) Examples of the crosslinkable unsaturated monomer having a methylol group include n-monomethylol (meth) acrylamide, n-butoxymethyl (meth) acrylamide,
An unsaturated monomer having a methylol group or an etherified methylol group such as isobutoxymethyl (meth) acrylamide is used. Among these, n-monomethylol (meth) acrylamide, n-butoxymethyl (meth) acrylamide and the like are preferably used.
(1) As a crosslinkable unsaturated monomer capable of undergoing a crosslink reaction with a methylol group, in addition to an unsaturated monomer having a methylol group,
Unsaturated monomers having a carboxyl group such as (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid and itaconic acid; 2-hydroxyethyl (meth) acrylate, 2-
An unsaturated monomer having a hydroxyl group such as hydroxypropyl (meth) acrylate; and an unsaturated monomer having a glycidyl group such as glycidyl (meth) acrylate are used. Among these, acrylic acid, methacrylic acid,
Itaconic acid, hydroxyethyl acrylate, glycidyl methacrylate and the like are preferably used.

(2) As the crosslinkable unsaturated monomer having an epoxy group, an unsaturated monomer having a glycidyl group such as glycidyl (meth) acrylate is used. (2)
Examples of the cross-linkable unsaturated monomer capable of cross-linking with an epoxy group include unsaturated monomers having a carboxyl group such as (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, and itaconic acid; 2-hydroxyethyl (Meth) acrylate,
An unsaturated monomer having a hydroxyl group such as 2-hydroxypropyl (meth) acrylate is used. Among these, acrylic acid, methacrylic acid, itaconic acid, hydroxyethyl acrylate and the like are preferably used.

(3) Examples of the crosslinkable unsaturated monomer having a carboxyl group include (meth) acrylic acid, maleic acid,
Unsaturated monomers having a carboxyl group such as fumaric acid, crotonic acid and itaconic acid are used. Among them, acrylic acid, methacrylic acid, itaconic acid and the like are preferably used. (3) Examples of the crosslinking unsaturated monomer capable of undergoing a crosslinking reaction with a carboxyl group include the above-mentioned unsaturated monomer having a methylol group or an etherified methylol group, an unsaturated monomer having an epoxy group, An unsaturated monomer having an alkoxysilyl group is used.

(4) As the crosslinkable unsaturated monomer having a hydroxyl group, an unsaturated monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate or 2-hydroxypropyl (meth) acrylate is used. Can be (4) As the crosslinkable unsaturated monomer capable of undergoing a crosslinking reaction with a hydroxyl group, the above-mentioned unsaturated monomer having a methylol group or an etherified methylol group, an unsaturated monomer having an epoxy group, An unsaturated monomer having an alkoxysilyl group is used.

(5) Examples of the crosslinkable unsaturated monomer having an alkoxysilyl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, vinylmethyldimethoxysilane, γ
-(Meth) acryloxypropyltrimethoxysilane,
γ- (meth) acryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldiethoxysilane and the like are used. Among them, γ- (meth) acryloxypropyltrimethoxysilane is preferably used. (5) As the crosslinkable unsaturated monomer capable of undergoing a crosslinking reaction with an alkoxysilyl group, the above-mentioned unsaturated monomer having a carboxyl group or unsaturated monomer having a hydroxyl group is used. Unsaturated monomers having a group are also used.

A polyfunctional crosslinkable unsaturated monomer having a property of having a crosslinkable structure in the emulsion is defined as having two functional groups.
Refers to the unsaturated monomer having the above, for example, divinylbenzene, 1,4-butanediol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyethylene glycol di A polyfunctional unsaturated monomer such as (meth) acrylate is used. Among these, divinylbenzene and trimethylolpropane di (meth) acrylate are preferably used.

The self-crosslinkable synthetic emulsion of the present invention can be prepared by a known method such as emulsion polymerization, for example, a method in which a polymerizable unsaturated monomer, a crosslinkable unsaturated monomer, an emulsifier and water are added in advance to a polymerization vessel charged with water. The mixed solution preliminarily emulsified and the aqueous solution of the polymerization initiator are separately dropped, and emulsion polymerization is performed to form an emulsion.If necessary, additives such as a stabilizer, a film-forming aid, and a preservative, as well as melamine and urea are used. A cross-linking agent for external addition such as is also used.

These self-crosslinkable synthetic resin emulsions can be synthesized by known means. For example, a polymerizable unsaturated monomer in a polymerization vessel charged with water in advance,
A mixed solution obtained by pre-emulsifying an emulsifier and water and an aqueous solution of a polymerization initiator can be separately dropped to carry out emulsion polymerization.

The emulsifier is not particularly limited and includes, for example, general anionic surfactants or nonionic surfactants.

Examples of the anionic surfactant include, for example,
Examples thereof include alkyl benzene sulfonate, alkyl naphthalene sulfonate, and polyethylene oxide alkyl ether sulfate. In the present invention, these anionic surfactants can be used alone or in combination of two or more.

Examples of the nonionic surfactant include, for example,
Polyethylene oxide alkyl ether, polyethylene oxide alkyl phenyl ether, polyethylene oxide-polypropylene oxide block copolymer, and the like. In the present invention, these nonionic surfactants can be used alone or in combination of two or more. You can also.

In the present invention, for example, an anionic surfactant and a nonionic surfactant can be used in combination.

The polymerization initiator is not particularly restricted but includes, for example, hydroperoxides such as cumene hydroperoxide and diisopropylbenzene hydroperoxide, peroxides such as benzoyl peroxide and lauroyl peroxide, and azobisisopropoxide. Organic polymerization initiators such as azo compounds such as butyronitrile, and inorganic polymerization initiators such as persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate. These polymerization initiators can be used alone or in combination of two or more. In addition, sodium bisulfite, a reducing agent such as ascorbic acid and a salt thereof is used in combination with a polymerization initiator,
A so-called redox polymerization initiator can also be used.

In producing the self-crosslinkable synthetic resin emulsion used in the present invention, the mixing ratio of the polymerizable unsaturated monomer and the crosslinkable unsaturated monomer copolymerizable with the polymerizable unsaturated monomer is as follows. 99.5 to 85 parts by weight of the saturated monomer, 0.5 to 15 parts by weight of the crosslinkable unsaturated monomer copolymerizable therewith, but 99.5 to 90 parts by weight of the polymerizable unsaturated monomer ,
The range of 0.5 to 10 parts by weight of a crosslinkable unsaturated monomer copolymerizable therewith is more preferable.

If the amount of the crosslinkable unsaturated monomer is less than 0.5 parts by weight, the mechanical damage resistance and blocking resistance of the coating applied to the base paper surface are reduced, and the object of the present invention is achieved. Can not do it. On the other hand, when the amount of the crosslinkable unsaturated monomer exceeds 15 parts by weight, the strength of the coating film is too large, the disintegration property is reduced, and there is a problem in recycling. In addition, the resistance to bending resistance decreases, and the object of the present invention cannot be achieved.

Further, the polymer having a glass transition temperature of −20 ° C. to 50 ° C. is preferably used from the viewpoints of moisture resistance, blocking resistance, mechanical damage resistance, easy defibration, and bendability.

The wax contained in the wax emulsion used in the present invention includes paraffin wax, microcrystalline wax, polyolefin wax, fatty acid ester wax, resin acid wax, petroleum resin wax, synthetic resin wax. And natural vegetable waxes. Among these, paraffin wax, polyolefin wax and natural vegetable wax are preferable, and paraffin wax, low melting point polyethylene wax and carnauba wax are particularly preferably used. These wax-containing wax emulsions may be used alone or as a mixture of two or more wax emulsions.

These waxes are emulsified and dispersed in water by known means and used as an emulsion. For example, it is used in the form of an emulsion obtained by mechanically emulsifying water by adding an emulsifier and a wax to water, or an emulsion of a wax having a carboxyl group and adding a basic compound such as ammonia or sodium hydroxide to water.

The amount of the wax emulsion used in the present invention ranges from 1 to 100 parts by weight on a solid basis with respect to 100 parts by weight of the solids of the self-crosslinkable synthetic resin emulsion. A range of parts by weight is more preferred.

Although the object of the present invention can be achieved even when the amount of the wax emulsion is less than 1 part by weight, the self-crosslinkable synthetic resin emulsion has too large a film-forming property and the disintegration is slightly lowered. However, it is at a level that does not cause any problem in industrial production. On the other hand, when the amount of the wax emulsion exceeds 100 parts by weight, the film-forming property is weak, and particularly, the resistance to mechanical damage resistance and bending property decreases, and the object of the present invention cannot be achieved. In addition, the adhesiveness and printability are reduced.

The moisture-proofing composition of the present invention may optionally contain additives such as a defoaming agent, a lubricant, an anti-blocking agent, a release agent, a lubricant, and a water repellent, as well as a pigment. Also,
Alcohols, organic solvents and the like may be added for the purpose of improving the drying property.

In order to further improve the drying property, aromatic hydrocarbons such as toluene and xylene; ketone solvents such as methyl ethyl ketone and acetone; chlorinated hydrocarbons such as carbon tetrachloride and trichloroethylene; isopropyl alcohol and isoamyl alcohol May be used as a self-crosslinkable synthetic resin dispersed or dissolved in an alcohol-based solvent.

As the base paper of the moisture-proof paper produced according to the present invention, high-quality paper, kraft paper, carton paper, corrugated paper and the like are used. Among these, when thick paper such as carton paper or corrugated paper is used, The mechanical damage resistance and the moisture proofness, which are the objects of the present invention, are exhibited.

In producing the moisture-proof paper of the present invention, known methods are used as a method for applying a moisture-proofing agent to the base paper. For example, any of a bar coater, a roll coater, an air knife coater, a rod coater, a gravure roll coater, a Meyer lot, a blade coater, a reverse coater and the like can be used, and no special coating device is required.

The greater the coating amount of the moisture-proofing composition used in the present invention, the better the moisture-proofing property.
In consideration of blocking resistance, bending resistance, and the like, the solid content is preferably in the range of ^{2 to 20} g / m ² .

The moisture-proof paper of the present invention can be obtained by applying a moisture-proof composition comprising a self-crosslinkable synthetic resin emulsion and a wax emulsion to a base paper, followed by drying and / or crosslinking. The conditions for the drying and / or cross-linking reaction vary depending on the type of the cross-linkable unsaturated monomer used, but the drying and / or cross-linking temperature is preferably in the range of 70 to 220 ° C. The drying and / or cross-linking time varies depending on the type of the cross-linkable unsaturated monomer, the solid concentration of the moisture-proofing agent, and the amount of application, but it is heated for several seconds to several minutes, and dried and / or dried.
Alternatively, a crosslinking reaction is performed.

As a method for heating, drying and / or crosslinking, known means is used. For example, a hot air drying method, a method using a hot roll, and a method using a hot plate are preferably used.

[0046]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the description, “parts” and “%” indicate “parts by weight” and “% by weight”, respectively.

Examples 1-2 and 4, Comparative Examples 1-2 Base paper (K-liner (corrugated cardboard), basis weight 200 g / m ² )
After applying a predetermined amount of the composition for moisture-proof processing of Table 1 using a bar coater, the composition was heated at 120 ° C. for 2 minutes with a hot-air drier (table coater, manufactured by Hirano Techseed Co., Ltd.) to obtain a test piece of moisture-proof paper. Was. Table 2 shows the measurement results of the physical properties of the test pieces.
Shown in

Example 3 Example 1 was carried out using a base paper (carton paper, basis weight 600 g / m ² ).
The same operation as described above was performed to obtain a test piece of moisture-proof paper. Table 2 shows the measurement results of the physical properties of the test piece.

The types of the self-crosslinkable synthetic resin emulsion and the wax-based emulsion in Table 1 and methods for evaluating the physical properties of the obtained test pieces are shown below.

[Self-crosslinkable synthetic resin emulsion (A-
1)] 180 parts of ion-exchanged water is charged into a polymerization vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen gas inlet tube.
After purging with nitrogen, the internal temperature was raised to 80 ° C. On the other hand, 110 parts of ion-exchanged water, 111.2 parts of styrene, 83.8 parts of 2-ethylhexyl acrylate, 3 parts of n-methylolacrylamic acid, 2 parts of acrylic acid, and 4 parts of sodium dodecylbenzenesulfonate were mixed and emulsified by a homomixer. And 10 parts of a 10% aqueous ammonium persulfate solution were separately added dropwise to the polymerization vessel over 2 hours.
The reaction was carried out for an hour to complete the polymerization. The resulting copolymer emulsion (hereinafter abbreviated as A-1) had a solid content of 40.1%.
% And the glass transition temperature of the polymer was 18 ° C.

[Self-crosslinkable synthetic resin emulsion (A-
2)] a polymerizable unsaturated monomer and a crosslinkable unsaturated monomer,
112 parts of styrene, 78 parts of 2-ethylhexyl acrylate,
A copolymer emulsion was obtained in the same manner as in the production example of the self-crosslinkable synthetic resin emulsion (A-1) except that glycidyl methacrylate was changed to 5 parts, methacrylic acid was changed to 3 parts, and 2-hydroxyethyl methacrylate was changed to 2 parts. The obtained copolymer emulsion (hereinafter abbreviated as A-2) had a solid content of 39.2%, and the glass transition temperature of the polymer was 20 ° C.

[Self-crosslinkable synthetic resin emulsion (A-
3)] a polymerizable unsaturated monomer and a crosslinkable unsaturated monomer,
88.6 parts of styrene, 2-ethylhexyl acrylate 101.4
Parts, methacrylic acid 6 parts, and γ-methacryloxypropyltrimethoxysilane 4 parts, except that the copolymerized emulsion was obtained in the same manner as in the production example of the self-crosslinkable synthetic resin emulsion (A-1). The obtained copolymer emulsion (hereinafter abbreviated as A-3) had a solid content of 39.8% and a glass transition temperature of the polymer of -10 ° C.

[Self-crosslinkable synthetic resin emulsion (A-
4)] In a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet tube, add 180 parts of ion-exchanged water and Emar
8 parts of 20C (25% aqueous solution, sodium polyoxyethylene lauryl ether sulfate, manufactured by Kao Corporation) was charged, and after nitrogen replacement, the internal temperature was raised to 80 ° C. Meanwhile, 110 parts of ion-exchanged water, 160 parts of vinylidene chloride, 38.4 parts of methyl methacrylate, 1.6 parts of divinylbenzene,
A mixture obtained by mixing and emulsifying 16 parts of 20C (25% aqueous solution, sodium polyoxyethylene lauryl ether sulfate, manufactured by Kao Corporation) with a homomixer, and a 10% aqueous ammonium persulfate solution
10 parts were separately dropped into the polymerization vessel over 2 hours, and further reacted at 80 ° C. for 5 hours to complete the polymerization. The obtained copolymer emulsion (hereinafter abbreviated as A-4) had a solid content of 39.5%, and the glass transition temperature of the polymer was 0 ° C.

[Synthetic resin emulsion (A-5)] As a carboxy-modified styrene-butadiene copolymer, XSBR
Latex 0695 (manufactured by Nippon Synthetic Rubber Co., Ltd., solid content concentration 50
%, Glass transition temperature -10 ° C) was designated as A-5.

[Wax emulsion (W-1)] As an emulsion of carboxy-modified polyethylene wax, HYTEC S-8512 (manufactured by Toho Chemical Industry, solid content 25%)
Was set to W-1.

[Wax emulsion (W-2)] Polylon 393 is used as a polyethylene wax emulsion.
Hydrin Z-7-30 (zinc stearate, manufactured by Chukyo Yushi Co., Ltd., solids concentration 31.5%) was blended with 100 parts (solid content 31%, manufactured by Chukyo Yushi Co., Ltd.) as a lubricant. W-2.

[Wax emulsion (W-3)] As a paraffin wax emulsion, prunite
707Z (manufactured by Shin-Nakamura Chemical Co., Ltd., solid content concentration 30%) with W-3
And

[Wax emulsion (W-4)] Polylon 393 is used as a polyethylene wax emulsion.
(Chukyo Yushi Co., Ltd., solid content concentration 31%) was designated as W-4.

[Wax Emulsion (W-5)] As a carnauba wax emulsion, Cellosol 524 (manufactured by Chukyo Yushi Co., Ltd., solid content concentration: 30%) was designated as W-5.

[Method for evaluating physical properties] (1) Mechanical scratch resistance-2 kg of chromium-plated 40 cm ² bottom surface with the coated surface facing up in an environment of room temperature 23 ° C. and 60% RH. The operation of moving the iron plate back and forth by about 10 cm was reciprocated 20 times, and the coated surface [mechanical damage resistance—room temperature] was observed and evaluated on a 4-point scale. ：: No change ○: Almost no change ：: Partially scratched or frayed part ×: Flaw generation and coating surface frayed over the entire surface

(2) Mechanical scratch resistance—High temperature 23 ° C., 60% RH environment, chromium plating with the coated surface of the test piece up, bottom area 40 cm ² , and 180 ° C.
An operation of moving the heated 2 kg iron plate back and forth about 10 cm back and forth was repeated five times, and the coated surface [mechanical damage resistance-high temperature] was observed and evaluated on a four-point scale. ：: No change ○: Almost no change ：: Partially scratched or frayed part ×: Flaw generation and coating surface frayed over the entire surface

(3) Moistureproofness Measured according to JIS Z-0208. With the coated surface of the test piece on the high temperature side, the moisture permeability was measured at 40 ° C. and 90% RH (unit: g / m ² · 24 hr).

(4) Disintegration 5 g of a test piece cut into 2 cm squares and 500 ml of water were stirred for 1 minute with a household juicer mixer, and then handmade paper was made with a square-type handmade paper machine (manufactured by Kumagaya Riki Kogyo). This was dried with a Yankee dryer at 120 ° C. for 15 seconds to obtain recycled paper.
The recycled paper was visually observed, and the disintegration was evaluated on a 4-point scale. ◎: Completely disintegrated ○: Almost disintegrated △: Polymer of 1 mm or more was present ×: Polymer of 2 mm or more was present in the form of a film.

(5) Blocking Resistance A test piece cut into a square of 5 cm was overlaid with the coated surfaces, and left under a load of 10 kg under an atmosphere of 40 ° C. and 90% RH for 24 hours. Thereafter, the paper was gradually cooled at room temperature, and the surface state of the paper when the test piece was peeled was visually evaluated in four stages. ：: no blocking ：: slight noise but no blocking ：: partial blocking ×: blocking over the entire surface

(6) Bendability The test piece was bent 180 degrees with the coated side facing outside, and the portion was visually inspected for the presence of cracks and cracks, and evaluated on a four-point scale. ◎: No change ：: Almost no change ：: Partial crack generation ×: Cracking or crack generation over the entire bent portion.

(7) Gluing property The test piece was cut to a width of 25 mm, and a 25 mm-long glue (vinyl acetate emulsion type adhesive, solid concentration 50
%), Apply a load of 2 kg for 5 seconds, and then
It was left for 1 day in a 60% RH atmosphere. The surface state of the paper when the test piece was peeled was visually evaluated in four stages. ◎: 100% base paper was destroyed ○: 51 to 99% base paper was destroyed △: 1 to 50% base paper was destroyed ×: The entire base paper was not destroyed.

(8) Printability A brown ink (ZPR-83 DF220, manufactured by Sakata Ink) was printed on the coated surface of the test piece with an RI tester, and the ink bleeding and sharpness were visually evaluated in three steps. ◎: No bleeding, clear ○: Slight bleeding, but almost good △: Large bleeding, 0.5 mm line width is about 1 mm or more. Blurred.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

Industrial Applicability The present invention is resistant to mechanical damage (excellent in mechanical damage resistance) in the box making process and in actual use during the production of moisture-proof paper, especially cardboard moisture-proof paper. An object of the present invention is to provide a moisture-proof composition having excellent blocking and bending properties, a moisture-proof paper provided with the composition, and a method for producing the same. For example, it is possible to provide a method for producing a moisture-proof paper having a good adhesive property of an aqueous adhesive and a good printability when producing corrugated cardboard or carton paper and producing a box using the same.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI D06M 15/263 D06M 15/263 15/273 15/273 15/37 15/37 15/693 15/693 D21H 19/24 D21H 1 / 34 M 19/18 1/36 5/00 Z D06M 13/02

Claims (12)

[Claims] (1) 99.5 to 85 parts by weight of a polymerizable unsaturated monomer,
A self-crosslinkable synthetic resin emulsion [emulsion (A)] and a wax emulsion [emulsion (W)] obtained by polymerizing this and 0.5 to 15 parts by weight of a copolymerizable crosslinkable unsaturated monomer. , Emulsion (A) 100 parts by weight (solid content), wax emulsion (W) 1
A composition for moisture-proof processing, which is contained in a proportion of 100 parts by weight (solid content). 2. The emulsion (A) has one or more kinds of crosslinkable unsaturated monomers having a functional group, and the functional groups react with each other by heating to form a crosslink. For moisture-proof processing. 3. The moisture-proof according to claim 2, wherein the crosslinkable unsaturated monomer in the emulsion (A) is an unsaturated monomer having a methylol group and an unsaturated monomer capable of undergoing a crosslinking reaction with the methylol group. Processing composition. 4. The crosslinkable unsaturated monomer in the emulsion (A) is an unsaturated monomer having an epoxy group and an unsaturated monomer capable of undergoing a crosslinking reaction with the epoxy group.
The composition for moisture-proof processing as described in the above. 5. The moisture-proof according to claim 2, wherein the crosslinkable unsaturated monomer in the emulsion (A) is an unsaturated monomer having a carboxyl group and an unsaturated monomer capable of cross-linking with the carboxyl group. Processing composition. 6. The moisture-proof according to claim 2, wherein the cross-linkable unsaturated monomer in the emulsion (A) is an unsaturated monomer having a hydroxyl group and an unsaturated monomer capable of cross-linking with the hydroxyl group. Processing composition. 7. The crosslinkable unsaturated monomer in the emulsion (A) is an unsaturated monomer having an alkoxysilyl group and an unsaturated monomer capable of undergoing a crosslinking reaction with the alkoxysilyl group. For moisture-proof processing. 8. The moisture-proof composition according to claim 1, wherein the emulsion (A) has a crosslinked structure in the emulsion by a polyfunctional crosslinkable unsaturated monomer. 9. The wax according to claim 1, wherein the wax contained in the wax emulsion (W) is at least one selected from the group consisting of polyolefin waxes, paraffin waxes and natural vegetable waxes. 3. The composition for moisture-proof processing according to item 1. 10. A method for producing a moisture-proof paper, comprising applying the composition for moisture-proof treatment according to any one of claims 1 to 9 to a base paper as a moisture-proof layer, followed by drying and / or crosslinking. 11. A moisture-proof paper having a moisture-proof layer on a base paper, wherein the moisture-proof layer is provided with the moisture-proofing composition according to any one of claims 1 to 9. 12. A packaging material using a moisture-proof paper having a moisture-proof layer on a base paper, wherein the moisture-proof layer is provided with the moisture-proof composition according to any one of claims 1 to 9.