JPH09221645A - Adhesive composition and information carrier sheet coated with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an adhesive composition capable of forming an adhesive layer having a sufficient thickness even with a small coating amount and obtaining a sufficient adhesive strength and easily peelable on a necessary occasion by imparting the adhesive composition with a property of thickening and gelling when heated (heat-sensitive gelation). SOLUTION: This composition consists of (A) a resin latex, preferably a resin latex whose content of an emulsifying agent in a liquid phase is zero or $0.01mmol/g, as an adhesive base agent and (B) a polymer which reciprocally changes its property between hydrophilic and hydrophobic properties at a constant temperature making it as a boarder, preferably at a temperature in the range of 15-100 deg.C in an amount of 0.01-50 pts. based on 100 pts.wt. of the component A. The composition is used for an information carrier sheet having a spreading surface which is tentatively adhered but easily peeled on a necessary occasion. Further, the component A is preferably a material obtained by the emulsion polymerization using a radically polymerizing emulsifying agent having (meth)acryloyloxy group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition and a sheet for information carrier, which is formed by applying the adhesive composition and has a facing surface that can be temporarily adhered but can be easily peeled off when necessary. More specifically, the present invention relates to a suitable adhesive composition for a confidential information carrier sheet such as a folding card, a laminated sheet, an information hiding sheet, and an information carrier sheet obtained by applying the same.

[0002]

2. Description of the Related Art Conventionally, there has been proposed an information carrier sheet provided with a layer of an adhesive composition comprising an adhesive base and a fine particulate filler having an incompatibility with the adhesive base. (For example, JP-A-5-69687).

[0003]

However, if the coating amount of the adhesive composition is 0.3 g / m ² or less in terms of solid content, the adhesive strength will be insufficient, and therefore the coating amount may be made larger than that. There was a problem that it was necessary. This is because the adhesive excessively penetrates (sinks) into the coated substrate (paper or the like).

[0004]

Means for Solving the Problems The inventors of the present invention have made earnest studies on an adhesive composition showing a sufficient adhesive force even if the coating amount is reduced, and as a result, the adhesive is thickened and gelated by heating. By imparting the property (temperature-sensitive gelling property), the adhesive composition thickens and gels during heating and drying, and excessive penetration of the adhesive into the substrate can be prevented. As a result, the coating amount can be reduced. It was found that an adhesive layer having a sufficient thickness can be formed to obtain a sufficient adhesive force, and the present invention has been achieved.

That is, although the present invention temporarily adheres,
An adhesive composition based on a resin latex (A), which is used for an information carrier sheet having a double-faced surface that can be easily peeled off when necessary, is reversible in hydrophilicity and hydrophobicity at a constant temperature as a boundary. The polymer (B) that changes to
0.01 to 50 relative to 100 parts by weight of the solid content of (A)
The present invention relates to an adhesive composition characterized by containing parts by weight; and an information carrier sheet comprising an adhesive layer made of the composition.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the resin latex (A) is not particularly limited, and examples thereof include vinyl polymer resins (acrylic resin, styrene-acrylic resin, styrene-resin).
Butadiene resin, butadiene-acrylonitrile resin, vinyl acetate resin, ethylene-vinyl acetate resin,
Ethylene / propylene resin, polybutadiene resin, etc.), polyurethane resin, polyurethane urea resin, polyester resin, natural rubber or styrene,
Examples thereof include a latex of a resin such as a grafted natural rubber obtained by graft-copolymerizing an alkyl (meth) acrylate.

Among (A), the resin constituting the latex of the vinyl polymer resin is a (co) polymer of a radical-polymerizable monomer, and the radical-polymerizable monomer is, for example, an acrylic monomer [methyl ( (Meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate, glycidyl (meth) acrylate,
Hydroxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) acryloyloxypolyglycerol, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl ( (Meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, etc.], styrene-based monomer (styrene, α-methylstyrene, vinyltoluene, etc.), butadiene-based monomer (butadiene, Isoprene, chloroprene, etc.), fatty acid vinyl monomers (vinyl acetate, vinyl propionate, etc.) and other monomers [ethylene, propylene, (meth) acrylonitrile, vinyl alcohol, Vinyl, vinyl alcohol, allyl alcohol, (meth) acrylamide, N,
N-dibutyl (meth) acrylamide, cyclohexyl (meth) acrylamide, N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, N-
Vinyl-2-pyrrolidone, vinylimidazole, N-vinylsuccinimide, p-aminostyrene, N-vinylcarbazole, 2-vinylpyridine, 2-cyanoethyl (meth) acrylate, (meth) acrylic acid, (anhydrous)
Maleic acid, fumaric acid, itaconic acid, vinyl sulfonic acid, styrene sulfonic acid, alkylallyl sulfosuccinic acid, (meth) acryloyl polyoxyalkylene sulfate, N, N-dimethylaminoethyl (meth) acrylamide, 1,1,1- Trimethylamine (meth) acrylimide, 1,1-dimethyl-1-ethylamine (meth) acrylimide, 1,1-dimethyl-1- (2′-
Phenyl-2'-hydroxyethyl) amine (meth) acrylimide, 1,1,1-trimethylamine (meth)
Acrylimide, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate,
Divinylbenzene and the like]. These monomers are used alone or in combination of two or more.

The polyurethane resin is an addition polymer of a polyol and a polyisocyanate compound, and the polyol component is a polyhydric alcohol (ethylene glycol, propylene glycol, butylene glycol, α,
α-dimethylol propionic acid, etc.), polyester polyol (polycaprolactone polyol, condensed polyester polyol of adipic acid with the polyhydric alcohol, etc.), polyether polyol (ethylene oxide and / or propylene oxide adduct of the polyhydric alcohol, Polyoxytetramethylene glycol etc.) and the like. Examples of the polyisocyanate compound include aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.), aliphatic diisocyanates (hexamethylene diisocyanate, isophorone diisocyanate, etc.) and modified products thereof (isocyanurate modified product, buret modified product, uretdione modified product). , Modified carbodiimide, etc.) and the like.

Polyurethane urea resin is an addition polymer with a polyisocyanate compound in which a polyamine is used in combination with the above-mentioned polyol, and as the polyamine, aromatic polyamine (diaminotoluene, 4,4'-diaminodiphenylmethane, etc.), aliphatic polyamine (Ethylenediamine, hexamethylenediamine, etc.), alicyclic polyamine (isophoronediamine, 4,4′-diaminocyclohexylmethane, etc.) and the like can be mentioned.

Specific examples of the latex of polyurethane resin or polyurethane urea resin include, for example, neutralized products of free isocyanate group-containing urethanene prepolymers from polyols, carboxyl group-containing diols and polyisocyanates, and if necessary diamines. The self-emulsifying latex obtained by dispersing it in water containing the above chain extender.

The resin latex (A) in the present invention is preferably a latex of acrylic resin, styrene-acrylic resin, styrene-butadiene resin, polyurethane resin and polyurethane urea resin.

When the resin latex (A) is a resin latex in which the amount of emulsifier in its liquid phase is usually 0.01 mmol / g or less, preferably 0.002 mmol / g or less, the temperature-sensitive adhesive composition It is preferable because the gelation property becomes better. The amount of the emulsifier is based on the weight of the liquid phase component in (A).

The amount of the emulsifier in the liquid phase is determined by analyzing the liquid phase obtained by removing the resin component from the resin latex by liquid chromatography or the like and quantifying it. As a method of removing the resin component from the resin latex, for example, a method of removing the resin component by coagulating and solidifying the resin component after freezing the resin latex, a method of removing the resin component by sedimentation and solidification by a centrifugal separator, an acid or an alkali. In addition, a method of removing and solidifying and removing the resin component may be used.

As a method for producing a resin latex in which the amount of the emulsifier in the liquid phase of the latex is 0 or 0.01 mmol / g or less, for example, a radically polymerizable monomer is known by using an emulsifier having a low solubility in water. Emulsion polymerization, a method of emulsion-polymerizing a radical-polymerizable monomer using a radical-polymerizable emulsifier (a) as an emulsifier, and a known method of using a water-soluble polymer as a protective colloid. Emulsion polymerization method, ionic functional group (carboxyl group, in an organic solvent,
A polymer having a sulfonic acid group, an amino group, etc.) is synthesized by a known method and, if necessary, neutralized with an alkali or an acid,
Examples include a method of adding water and removing the solvent after emulsification.

The emulsifier having a low solubility in water in the method (1) has an HLB value of 3 to 9, for example, an amine or an alkali metal salt of a fatty acid having 22 or more carbon atoms, an aliphatic or aromatic having 15 or more carbon atoms. Examples thereof include ethylene oxide 1 to 6 mol adducts of group alcohols.

Examples of the radical-polymerizable emulsifier (a) in the method of (1) include (1) anionic (meth) acrylic acid esters, (2) anionic (meth) acrylamides, and (3) anionic styrene derivatives. , (4) nonionic (meth) acrylic acid esters, (5) nonionic (meth) acrylamides, (6) nonionic styrene derivatives, (7) cationic (meth) acrylic acid esters, (8)
Examples include cationic (meth) acrylamides and (9) cationic styrene derivatives.

(1) Specific examples of anionic (meth) acrylic acid esters include, for example, CH ₂ ═C (R ¹ ) CO ₂ (CH ₂ ) mSO ₃ M (wherein R ¹ is a hydrogen atom or Methyl group, m is 1 to 24
And M represents an alkali metal ion, an ammonium ion or an aminium ion. ), C
H ₂ ═C (R ¹ ) CO (AO) pOSO ₃ M or CH ₂ ═C (R ¹ ) CO (AO) pOCH ₂ CO ₂ M (wherein R ¹ is a hydrogen atom or a methyl group, and AO is the number of carbon atoms. An oxyalkylene group of 2 to 4, p is an integer of 2 to 200,
M represents an alkali metal ion, an ammonium ion or an aminium ion. ) And the like.

(2) Specific examples of the anionic (meth) acrylamides include, for example, CH ₂ ═C (R ¹ ) CONH (CH ₂ ) mSO ₃ M (wherein R ¹ is a hydrogen atom or a methyl group, m Is an integer of 1 to 24, M is an alkali metal ion, an ammonium ion or an aminium ion.), CH
₂ = C (R ¹ ) CONHCH ₂ (AO) pOSO ₃ M or CH ₂ ═C (R ¹ ) CONHCH ₂ (AO) pOCH ₂ CO ₂
M (In the formula, R ¹ is a hydrogen atom or a methyl group, AO is an oxyalkylene group having 2 to 4 carbon atoms, p is an integer of 2 to 200,
M represents an alkali metal ion, an ammonium ion or an aminium ion. ) And the like. Specific examples of (3) anionic styrene derivatives include, for example, CH ₂ ═CHAr (CH ₂ ) rSO ₃ M (wherein Ar is an aromatic ring, r is an integer of 4 to 24, and M is an alkali metal ion). , An ammonium ion, or an aminium ion), CH ₂ ═CHA
r (AO) pSO ₃ M or CH ₂ ═CHAr (AO) pOCH ₂ CO ₂ M (wherein Ar is an aromatic ring, p is an integer of 2 to 200, M is an alkali metal ion, ammonium ion, or aminium). And the like).

(4) Specific examples of the nonionic (meth) acrylic acid esters include, for example, CH ₂ ═C (R ¹ ) CO (EO) pOR ² (wherein R ¹ is a hydrogen atom or a methyl group). , EO is an oxyethylene group, p is an integer of 2 to 200, and R ² is a carbon number of 5
21 represents an alkyl group, an alkenyl group or an aralkyl group. ), CH ₂ = C (R ¹ ) CO (P
O) p (EO) qOR ³ or CH ₂ ═C (R ¹ ) CO (EO) p (PO) qOR ³ (wherein R ¹ is a hydrogen atom or a methyl group, PO is an oxypropylene group, and EO is oxyethylene. Groups, p and q are each independently an integer of 2 to 200, R ³ is a hydrogen atom, an alkyl group having 1 to 21 carbon atoms, an alkenyl group or an aralkyl group.) And the like. (5) Specific examples of the nonionic (meth) acrylamides include CH ₂ ═C (R ¹ ) CONHCH ₂ (EO) pOR ³ (wherein R ¹ is a hydrogen atom or a methyl group, and EO is oxyethylene. Group, p is an integer of 2 to 200, R ³ is a carbon number of 5 to 2
1 represents an alkyl group, an alkenyl group or an aralkyl group. ). (6) Specific examples of the nonionic styrene derivatives include, for example, CH ₂ ═CHAr (EO) pOR ³ (wherein Ar is an aromatic ring, EO is an oxyethylene group, p is an integer of 2 to 200, and R is ³ represents an alkyl group having 5 to 21 carbon atoms, an alkenyl group or an aralkyl group.) And the like.

Specific examples of the (7) cationic (meth) acrylic acid esters include, for example, [CH ₂ ═C (R ¹ ) CO (AO) pN (R ³ ) ₃ ] X [wherein R ¹ Is a hydrogen atom or a methyl group, AO is an oxyalkylene group having 2 to 4 carbon atoms, p is an integer of 2 to 200,
R ³ is a hydrogen atom or an alkyl group having 4 to 21 carbon atoms, an alkenyl group or an aralkyl group, X is a halogen, N
O ₃ , HSO ₄ , CH ₃ OSO ₂ , (CH ₃ O) ₂ PO ₂ , C
Each anion of H ₃ CO ₂ or HCO ₃ is shown. ] And the like. (8) Specific examples of the cationic (meth) acrylamides include, for example, [CH ₂ ═C (R ¹ ) CONH (AO) pN (R ³ ) ₃ ] X [wherein R ¹ is a hydrogen atom or methyl. Group, AO is an oxyalkylene group having 2 to 4 carbon atoms, p is an integer of 2 to 200,
R ³ is a hydrogen atom or an alkyl group having 4 to 21 carbon atoms, an alkenyl group or an aralkyl group, X is a halogen, N
O ₃ , HSO ₄ , CH ₃ OSO ₂ , (CH ₃ O) ₂ PO ₂ , C
Each anion of H ₃ CO ₂ or HCO ₃ is shown. ] And the like. (9) Specific examples of the cationic styrene derivatives include, for example, [CH ₂ ═CHAr (AO) pN (R ³ ) ₃ ] X [wherein Ar is an aromatic ring and AO is an oxy group having 2 to 4 carbon atoms]. Alkylene group, p is an integer of 2 to 200, R ³ is a hydrogen atom or an alkyl group having 4 to 21 carbon atoms, an alkenyl group or an aralkyl group, X is a halogen, NO ₃ , HSO ₄ , CH ₃
OSO ₂ , (CH ₃ O) ₂ PO ₂ , CH ₃ CO ₂ or HCO
Each anion of ₃ is shown. ] And the like.

Of these, the pigment dispersants (1) to (6) are preferable because they are unlikely to aggregate with a conventional pigment dispersant [eg, sodium poly (meth) acrylate], and (1)
Of these, (meth) acrylic acid ester having an anionic group and a polyoxypropylene chain is particularly preferable in that it gives a more stable latex.

The amount of the emulsifier used in the above or the method is usually 0.1 to 20% by weight based on the resin content.

Specific examples of the water-soluble polymer used as a protective colloid in the method of (1) include, for example, water-soluble vinyl polymers containing a hydrophilic radical-polymerizable monomer as a constituent unit, polyethylene glycol, celluloses and the like. Can be mentioned. Examples of the hydrophilic radically polymerizable monomer include carboxylic acids [(meth) acrylic acid, (anhydrous) maleic acid, fumaric acid, itaconic acid, etc.]
And its alkali salts, sulfonic acids [styrene sulfonic acid, (meth) acryloylalkyl sulfonic acid, etc.] and its alkali salts, amino group-containing monomers [dimethylaminoethyl (meth) acrylate, vinyldimethylaniline, etc.] and salts of these acids, Hydroxyl group-containing monomers [ethylene oxide adducts of (meth) acrylic acid, vinyl alcohol, etc.], amides [(meth) acrylic acid amide, etc.] and amine imides [1,1,1-trimethylamine (meth) acrylic imide] are mentioned. .

Specific examples of the polymer having an ionic functional group in the method (1) include a water-insoluble vinyl polymer containing the hydrophilic radical-polymerizable monomer as a constituent unit, and a polyol component having an ionic functional group ( Examples thereof include a polyurethane resin and a polyurethane urea resin containing dimethylolpropionic acid, polyethylene glycol, etc.) as a constituent unit.

Among these methods, the method in which the resin latex can be easily obtained under usual conditions is particularly preferable.

The resin content in the resin latex (A) is usually 20 to 75%, preferably 40 to 60%. Also,
The particle size of the resin suspended in the resin latex (A) is usually 10 to 500 nm, preferably 50 to 300 nm, and the pH is usually 3 to 12, preferably 6 to 10. If the particle size exceeds 500 nm or the pH is 3
When it is less than 12 or more than 12, the temperature-sensitive gelling property of (B) cannot be sufficiently exhibited.

Examples of the polymer (B) whose hydrophilicity and hydrophobicity reversibly change at the boundary of a certain temperature in the present invention include, for example, cyclic amines or alkylene oxide adducts of acyclic amines having 5 or more carbon atoms. (B1) containing 50 wt% or more of the vinyl carboxylic acid ester (b1) as a structural unit, N-alkyl, N-alkylene or N-alkoxyalkyl (meth) acrylamide (b
50% by weight of a polymer (B2) containing 50% by weight or more as a constitutional unit, a polyethylene glycol monoalkyl ether mono (meth) acrylate or a polyalkylene glycol monophenyl ether mono (meth) acrylate (b3) as a constitutional unit. The polymer (B3) containing the above, polyethylene glycol monoalkyl monovinyl ether or polyethylene glycol monophenyl monovinyl ether (b4) as a constituent unit is 50
A polymer (B4) containing 50% by weight or more and a polymer (B5) containing 50% by weight or more as a constitutional unit of a polyethylene glycol monoalkyl ether mono (vinylphenyl) ether (b5) are included.

Examples of the polymer (B1) include the above-mentioned vinyl carboxylic acid ester (b1) [non-aromatic heterocyclic amine (aziridine, pyrrolidine, 2-methylpiperidine, 1-methylpiperazine, morpholine, 3-pyrroline, etc. ); Aromatic heterocyclic amine (2-hydroxypyridine, pyrrole, etc.); Aromatic amine (N-methylaniline, etc.); Aliphatic acyclic amine having 5 or more carbon atoms (isopentylamine, methylbutylamine, methylhexylamine) , Dibutylamine and the like) (ethylene oxide and / or propylene oxide 1 to 50 mol adduct (meth) acrylic acid ester and the like] as a structural unit.
Vinyl polymers and the like containing at least 5% by weight, such as JP-A-6-984
Those described in Japanese Patent No. 8 can be mentioned.

Examples of the polymer (B2) include N-alkyl-, N-alkylene- or N-alkoxyalkyl (meth) acrylamide (b2) [N-isopropyl (meth) acrylamide, N- (meth) acryloylpiperidine, (Meth) acryloylmorpholine, N-isopropoxypropyl (meth) acrylamide, N-ethoxyethyl (meth) acrylamide and the like] as a constituent unit in a proportion of 50% by weight or more.
Examples thereof include those described in Japanese Patent No. 14276.

As the polymer (B3), the above-mentioned polyethylene glycol monoalkyl ether mono (meth) acrylate or polyalkylene glycol monophenyl ether mono (meth) acrylate (b3) [polyethylene glycol monobutyl ether mono (meth) acrylate, polyethylene glycol Monophenyl ether mono (meth) acrylate, (poly) oxypropylene polyoxyethylene glycol monomethyl ether mono (meth) acrylate, polyoxyethylene (poly) oxypropylene polyoxyethylene glycol monomethyl ether mono (meth) acrylate, etc.] As a vinyl polymer containing 50% by weight or more,
No. 23375, etc. are mentioned.

As the polymer (B4), the above-mentioned polyethylene glycol monoalkyl monovinyl ether or polyethylene glycol monophenyl monovinyl ether (b4) [polyethylene glycol monobutyl monovinyl ether, (poly) oxypropylene polyoxyethylene glycol monomethyl monovinyl ether, polyethylene Glycol monophenyl monovinyl ether, etc.]
A vinyl polymer containing 50% by weight or more as a structural unit, "Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 30, page 2407 (199).
2 years) ”.

As the polymer (B5), the above-mentioned polyethylene glycol monoalkyl ether mono (vinylphenyl) ether (b5) [polyethylene glycol monomethyl mono (vinylphenyl) ether polyethylene glycol monopropyl mono (vinylphenyl) ether, etc.] is constituted. A vinyl polymer containing 50% by weight or more as a unit may be mentioned.

Of these, the polymer (B1) is particularly preferable because it has a high effect of suppressing the penetration of the adhesive into the substrate.

The weight average molecular weight of the polymer (B) is usually 1,
000 to 5,000,000, preferably 10,000
0-2,000,000, particularly preferably 100,000
It is 0 to 1,000,000.

In the case of (B), hydrophilicity and hydrophobicity change reversibly at a constant temperature as a boundary, and the temperature (transition temperature) at which the hydrophilicity and hydrophobicity change is usually 15 to 100 ° C. ,
It is preferably 40 to 80 ° C. If the transition temperature is less than 15 ° C, the viscosity of the compounded liquid becomes unstable and handling becomes difficult, and if it exceeds 100 ° C, the effect of suppressing the permeation of the adhesive into the coated substrate is significantly reduced. The transition temperature is 1 in (B).
% Aqueous solution is gradually heated, and the temperature at which the aqueous solution starts to become cloudy or gel is measured.

The proportion of (B) per 100 parts by weight of the solid content (resin content) of (A) in the adhesive composition of the present invention is usually 0.01 to 50 parts by weight, preferably 0.1 to 30 parts by weight. Parts, more preferably 0.5 to 20 parts by weight.
If the proportion of (B) is less than 0.01 parts by weight, the temperature-sensitive gelling property of the adhesive composition will be insufficient, and the effect of preventing the penetration of the adhesive into the substrate will be insufficient. On the other hand, if the amount exceeds 50 parts by weight, the adhesive strength will decrease.

The adhesive composition of the present invention contains the resin latex (A) and the polymer (B) alone or an aqueous solution of (B) at a temperature lower than the temperature at which (B) changes from hydrophilic to hydrophobic. It is obtained by mixing at a temperature with a conventional mixing device (a paddle type stirring blade or the like).

The adhesive composition of the present invention contains, if necessary, known tackifiers (alkylphenol-formalin resin, terpene resin, etc.), fine particles [clay, calcined clay, Kaolin, calcined kaolin, calcium carbonate, satin white, titanium oxide, aluminum oxide, hydrous silicic acid, silicic acid anhydride, calcium silicate, aluminum silicate, magnesium silicate, sodium aluminosilicate, magnesium aluminosilicate, diatomaceous earth, hydroxylated Aluminum, barium sulfate,
Zinc oxide, calcium sulfate, talc; plastic pigments (styrene-based, styrene / butadiene-based, styrene / acrylic-based, acrylic-based, solid resin such as urea-formalin resin, hollow, core-shell-shaped beads, etc.), starch , Silica, activated clay, zinc oxide, shirasu balloon, etc.], water-soluble resin (hydroxyethyl cellulose,
Methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyvinyl alcohol, solubilized starch,
Modified polyvinyl alcohol, styrene-maleic anhydride copolymer or an alkali salt thereof, ethylene-maleic anhydride copolymer or an alkali salt thereof, sodium polyacrylate, acrylamide-acrylic acid ester copolymer, etc.), an antioxidant, UV inhibitors, dyes, lubricants, foaming agents, flame retardants, etc. can be added.

A method for producing the information carrier sheet of the present invention will be described. The support base material is not particularly limited,
Various types of sheets such as paper, coated paper, synthetic paper, and plastic film can be used, but when the adhesive composition of the present invention is applied to a porous substrate such as paper, a particularly remarkable effect is exhibited. To do.

The information carrier sheet can be used as a single layer or a multilayer using the adhesive composition of the present invention using a coating machine (air knife coater, bar coater, roll coater, blade coater, curtain coater, champlex coater, gravure coater, etc.). It can be obtained by coating uniformly, flatly or with fine irregularities, coating with heat, drying with a drier, and calendering for smoothing if necessary.

In heating and drying with a dryer, it is preferable to heat the adhesive composition as quickly as possible after coating in order to quickly thicken and gel the adhesive composition. As a dryer, an infrared heater is used before drying with hot air. A heating and drying system for preheating by such means as is preferable.

The calendar treatment is preferable in order to further improve the blocking characteristics and the print fixing suitability. The pressure during calendering is usually 1 to 10 kg / cm ² .

The coating amount of the adhesive is usually 0.1 to 10 g / m ² as weight of solids, preferably 0.2-5 g / m ²
It is. If the coating amount is less than 0.1 g / m ² , the sheet may be easily peeled off during normal handling, and if it exceeds 10 g / m ² , the sheet may be easily curled and a problem may occur in printability.

The information carrier sheet obtained in this manner is a postcard having confidentiality such as a three-fold postcard, a two-fold postcard, a partially folding type postcard, and a superposition type postcard, and a size-expandable organizer. It is used as a sheet, a printing paper, a copying paper, or the like, and it is particularly preferable that at least a part of the layer made of the adhesive composition is a surface for describing concealment information.

[0045]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. Parts in Examples are parts by weight and% is% by weight.

Production Example 1 10 parts of 2-morpholinoethyl methacrylate (1 mol adduct of morpholine with ethylene oxide, ester with methacrylic acid) and 2,2'-azobis (2,4-dimethylvaleronitrile) (AIVN) 0.01 A part was added to an ampoule, frozen and deaerated, then sealed, and polymerized at 50 ° C. for 8 hours to obtain a polymer 1.

Production Example 2 9 parts of 2- (2-morpholinoethoxy) ethyl methacrylate (ester of 2 mol adduct of morpholine with ethylene oxide and methacrylic acid), 10 parts of methyl methacrylate
Parts and 0.01 parts of AIVN were added to an ampoule, freeze-deaerated, sealed, and polymerized at 60 ° C. for 8 hours to obtain a polymer 2.

Production Example 3 Acryloyloxypolyoxypropylene (degree of polymerization = 1) was used as an emulsifier having a radically polymerizable group in a pressure reaction vessel equipped with a stirrer, a dropping cylinder, a nitrogen gas introducing tube, and a thermometer.
2) Sulfuric acid ester Na salt 10 parts, water 102 parts, styrene 45 parts, methyl methacrylate 9 parts, methacrylic acid 4
, 1 part of sodium persulfate and 0.2 part of lauryl mercaptan were charged, and the system was purged with nitrogen gas under stirring.
37 parts of butadiene was press-fitted from a dropping cylinder and 3
The reaction was carried out for 0 hours and then at 85 ° C. for 5 hours. Then adjust the pH to 8.5 with aqueous sodium hydroxide and strip the unreacted monomer under reduced pressure to give SBR.
-Based resin latex (solid content 47.9%, hereinafter "SBR
1 "). The amount of emulsifier in the liquid phase of SBR1 was 0.0003 mmol / g.

Production Example 4 In the same manner as in Production Example 3, 50 parts of styrene, 4 parts of methyl methacrylate, 4 parts of methacrylic acid, 5 parts of acrylonitrile, 32 parts of butadiene and methacryloyloxypolyoxypropylene (polymerization degree = 9) sulfuric acid ester. From 10 parts of Na salt, SBR resin latex (solid content 48.3
%, Hereinafter referred to as “SBR2”). The amount of emulsifier in the liquid phase of SBR2 was 0.0005 mmol / g.

Production Example 5 102 parts of water and 1 part of sodium persulfate were added to a reaction vessel equipped with a stirrer, a dropping funnel, a reflux condenser, a nitrogen gas inlet tube, and a thermometer, and the temperature was raised to 80 ° C. Then, acryloyloxypolyoxypropylene (degree of polymerization = 12) sulfuric acid ester Na salt 1 as an emulsifier having a radically polymerizable group
0 parts, 60 parts of n-butyl acrylate, 20 parts of 2-ethylhexyl acrylate, 4 parts of acrylic acid, 12 parts of vinyl acetate, and polycaprolactone adduct to 2-hydroxyethyl methacrylate, obtained by ring-opening addition of succinic anhydride [ A mixture of 5 parts of "FM-1A" manufactured by Daicel Chemical Industries, Ltd. and 0.2 parts of lauryl mercaptan was continuously added dropwise from a dropping funnel over 4 hours under a nitrogen stream.
Furthermore, after reacting at 85 ° C. for 3 hours, the pH was adjusted to 8.5 with an aqueous sodium hydroxide solution, and unreacted monomer was stripped under reduced pressure to obtain an acrylic resin latex 1 (solid content 48.5%, Hereinafter referred to as "ALx1"). The amount of emulsifier in the liquid phase of the ALx1 is 0.0
It was 003 mmol / g.

Production Example 6 In the same manner as in Production Example 5, methacryloyloxypolyoxypropylene (degree of polymerization = 9) sulfuric acid ester Na salt 10
Parts, n-butyl acrylate 35 parts, 2-ethylhexyl acrylate 45 parts, acrylic acid 4 parts, "FM-1
A ”from 5 parts and vinyl acetate 10 parts, acrylic resin latex 2 (solid content 47.8%, hereinafter“ ALx2 ”)
). The amount of emulsifier in the liquid phase of the ALx2 is
It was 0.0005 mmol / g.

Example 1 100 parts of SBR1 obtained in Production Example 3, 2 parts of a 30% aqueous solution of the polymer 1 obtained in Production Example 1, 5 parts of alkylphenol-formaldehyde resin, silica gel (average particle size 4 μ) 2
Adhesive composition 1 of the present invention was obtained by mixing 5 parts of wheat starch and 25 parts of wheat starch (average particle size 15 µ). This adhesive composition 1 was applied to a high-quality paper of 58 g / m ^{2 in} a dry coating amount of 0.3 g /
The information carrier sheet 1 is coated on one side with a blade coater so as to have a m ² (solid content) and dried for 1 minute in a hot air dryer (hot air temperature; 130 ° C.) provided with an infrared heating zone. Obtained. Table 1 shows the results of measuring the adhesive strength and heat resistance and abrasion resistance of the sheet.

Example 2 An adhesive composition 2 of the present invention was obtained in the same manner except that the polymer 2 of Production Example 2 was used in the same amount in place of the polymer 1 of Example 1. Using this adhesive composition 2, an information carrier sheet 2 was prepared in the same manner as in Example 1. Table 1 shows the results of measuring the adhesive strength and heat resistance and abrasion resistance of the sheet.

Example 3 Instead of SBR1 in Example 1, SBR in Production Example 4 was used.
An adhesive composition 3 of the present invention was obtained in the same manner as in Example 1 except that the same amount of 2 was used. Using this adhesive composition 3, an information carrier sheet 3 was prepared in the same manner as in Example 1. Table 1 shows the results of measuring the adhesive strength and heat resistance and abrasion resistance of the sheet.

Example 4 In place of SBR1 in Example 1, ALx of Production Example 5 was used.
An adhesive composition 4 of the present invention was obtained in the same manner as in Example 1 except that 1 was used in the same amount. Using this adhesive composition 4, an information carrier sheet 4 was prepared in the same manner as in Example 1. Table 1 shows the results of measuring the adhesive strength and heat resistance and abrasion resistance of the sheet.

Example 5 Instead of SBR1 in Example 1, ALx of Production Example 6 was used.
An adhesive composition 5 of the present invention was obtained in the same manner as in Example 1 except that the same amount of 2 was used. Using this adhesive composition 5, an information carrier sheet 5 was prepared in the same manner as in Example 1. Table 1 shows the results of measuring the adhesive strength and heat resistance and abrasion resistance of the sheet.

Comparative Example 1 A comparative adhesive composition 6 was obtained in the same manner as in Example 1 except that the polymer 1 was not used. This adhesive composition 6
A comparative information carrier sheet 6 was obtained by using the same procedure and conditions as in Example 1. Table 1 shows the results of measuring the adhesive strength and heat resistance and abrasion resistance of the sheet.

Comparative Example 2 A comparative adhesive composition 7 was obtained in the same manner as in Example 4, except that the polymer 1 was not used. This adhesive composition 7
A comparative information carrier sheet 7 was obtained using the same procedure and conditions as in Example 1. Table 1 shows the results of measuring the adhesive strength and heat resistance and abrasion resistance of the sheet.

[0059]

[Table 1]

(Test Method) Adhesive Strength-1: The sheet was heated at 180 ° C. for 2 seconds and then pressure-bonded with a dry sealer at a pressure of 50 kg / cm ² . This was cut into a width of 25 mm, and the peel strength was measured by an autograph. Depending on the level of peel strength, x (0
~ 15g / 25mm), △ (16-30g / 25m)
m), ○ (31 to 50 g / 25 mm), ◎ (51 to 10)
0 g / 25 mm). Adhesive strength-2: After heating the sheet at 180 ° C. for 2 seconds, R
Apply 0.5 g / m ² of silicone oil with an I printer,
It was pressure-bonded with a dry sealer at a pressure of 100 kg / cm ² . This was cut into a width of 25 mm, and the peel strength was measured by an autograph. ×, depending on the level of peel strength
(0-15g / 25mm), △ (16-30g / 25m)
m), ○ (31 to 50 g / 25 mm), ◎ (51 to 10)
0 g / 25 mm). Heat and abrasion resistance: 200 g / at a temperature of 150 ° C on a sheet
The surface of the adhesive was abraded with metal while applying a load of cm ² , and the degree of abrasion was observed. Depending on the level of wear,
× (the worn area is 31% or more of the worn surface), Δ (the worn area is 11 to 30% of the worn surface), ○ (the worn area is 1 to 10% of the worn surface), ◎ (the worn area is 1 of the wear surface
%).

[0061]

The adhesive composition of the present invention is used as an adhesive for an information carrier sheet because it has the property of rapidly thickening and gelling by heating during heating and drying (so-called temperature-sensitive gelling property). In this case, since the adhesive composition is dried in a state of being immobilized at the time of heating and drying, the adhesive does not penetrate (sink) into a substrate such as paper, and a thick and uniform adhesive layer can be obtained. . For this reason, sufficient adhesive strength is exhibited even with a small amount of adhesive applied, and the abrasion resistance is also excellent. Further, since the adhesive layer of this information carrier sheet is bulky, there is also an advantage that it is excellent in printability.

Claims (5)

[Claims] 1. A sheet for information carrier, which is temporarily adhered but has a facing surface that can be easily peeled off when necessary,
In an adhesive composition having a resin latex (A) as an adhesive base, a polymer (B) whose hydrophilicity and hydrophobicity reversibly change at a constant temperature as a boundary is added to a solid content of (A). 10
An adhesive composition containing 0.01 to 50 parts by weight with respect to 0 parts by weight. 2. The adhesive composition according to claim 1, wherein (A) is a resin latex in which the amount of emulsifier in the liquid phase is 0 or 0.01 mmol / g or less. 3. The adhesive composition according to claim 1, wherein (A) is a resin latex emulsion-polymerized using a radical-polymerizable emulsifier having a (meth) acryloyloxy group. 4. The adhesive composition according to claim 1, wherein the temperature at which the hydrophilicity and the hydrophobicity of (B) change reversibly is 15 to 100 ° C. 5. An adhesive layer obtained by applying the adhesive composition according to any one of claims 1 to 4 on at least a part of the surface of the base sheet and heating and drying the adhesive composition. Information carrier sheet.