JPH1081865A - Adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive compsn. having an excellent adhesion to an adherend and also thermal and water resistances. SOLUTION: This compsn. comprises (A) an emulsion comprising an ethylene/ vinyl acetate copolymer having an ethylene content of 5 to 40wt.% and a toluene-insolubles content of at least 70wt.% or (B) an emulsion comprising a (meth)acrylic acid/ethylene/vinyl acetate copolymer having a (meth)acrylic acid content of 0.3 to 5wt.%, an ethylene content of 5 to 40wt.% and a toluene- insolubles content of at least 70wt.%, and (C) an emulsion comprising a urethane resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a novel adhesive exhibiting excellent adhesive strength, heat resistance and water resistance to adherends such as inorganic materials such as plastic materials, wood, paper and concrete. Composition.

[0002]

2. Description of the Related Art Conventionally, for bonding plastic materials such as vinyl chloride resin, polyolefin resin and polyester resin, wood, paper, concrete and the like, ethylene-vinyl acetate copolymer, acrylate-vinyl acetate have been used. Adhesive compositions containing an emulsion as a main component such as a copolymer have been used, and in order to further improve the adhesion and heat resistance of such an emulsion, for example,
Japanese Patent Publication No. Hei 7-26072 discloses a method in which an emulsion containing a urethane resin as a main component is blended with the above emulsion.

Using such adhesive compositions, wood materials such as rawan plywood, medium fiberboard (MDF, medium density fiberboard), particle board, and solid wood; cement board, gypsum board, ALC, etc. A sheet of a plastic material such as a hard or semi-hard vinyl chloride resin, a polyolefin resin, or a polyester resin on a base material such as an inorganic material; a veneer obtained by processing wood into a sheet;
A surface decorative material obtained by laminating a so-called surface decorative sheet such as decorative paper on which various decorative prints are applied and imparting a design property is called a laminated plywood or the like, and is widely used as various building members and furniture members.

However, the adhesive composition does not have sufficient heat resistance, and when the obtained surface decorative material is used in a portion where a local load is applied at a high temperature, partial blistering or peeling occurs. There was a problem of doing. In addition, there is a problem that the water resistance is insufficient, and it cannot be used as a member around water.

[0005] When a decorative sheet is adhered to a substrate using the above-mentioned adhesive composition, the adhesive composition is undried and still flowing in order to obtain sufficient wetting on the surface of the substrate. The wet bonding method is used in which the bonding is performed without losing the properties.However, when the base material is a porous material, the bonding is performed only on the convex portions because there are many irregularities on the surface. No spots tend to adhere. The point bonding state means that the effective bonding area is smaller than in the case of the smooth substrate, and there is a problem that the original bonding strength of the adherend cannot be exhibited. In addition, since the adhesive composition has an increased adhesive strength due to the diffusion of water, volume contraction cannot be avoided. For this reason, depending on the surface decorative sheet, the uneven shape of the base material may appear as it is on the sheet surface after bonding, and the appearance of the surface decorative material may be reduced.

In order to solve these problems, there are methods such as pre-filling the porous material or applying various resin components as primers, but these methods hinder productivity. Therefore, it was practically difficult to apply.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and an object of the present invention is to provide an adhesive composition having excellent adhesion to an adherend and excellent heat resistance and water resistance. To provide things.

[0008]

The adhesive composition of the invention according to claim 1 of the present invention (hereinafter referred to as the first invention) comprises:
(A) an emulsion comprising an ethylene-vinyl acetate copolymer having an ethylene content of 5 to 40% by weight, wherein the toluene-insoluble content is 70% by weight or more, or (B) a toluene-insoluble content of 70% by weight or more, An emulsion composed of (meth) acrylic acid-ethylene-vinyl acetate copolymer having a (meth) acrylic acid content of 0.3 to 5% by weight and an ethylene content of 5 to 40% by weight, and an emulsion composed of (C) a urethane resin And is compounded.

The invention according to claim 2 of the present invention (hereinafter referred to as "second
The adhesive composition according to the first aspect, wherein the emulsion (C) is formed from a urethane resin having a polyester skeleton in the molecule and containing a sulfonic acid (salt) residue in the skeleton. It is characterized by.

Hereinafter, the first invention will be described. The adhesive composition of the first invention comprises an emulsion (A) comprising an ethylene-vinyl acetate copolymer or an emulsion (B) comprising a (meth) acrylic acid-ethylene-vinyl acetate copolymer and an emulsion comprising a urethane resin. (C) is blended.

The ethylene content of the ethylene-vinyl acetate copolymer used in the emulsion (A) is 5-4.
0% by weight, preferably 10 to 25% by weight.
If the ethylene content is less than 5% by weight, the low-temperature adhesiveness decreases, and the film-forming temperature increases, resulting in poor film-forming properties. When the ethylene content is more than 40% by weight, the adhesiveness to various adherends is deteriorated, and the heat resistance is reduced.

In the (meth) acrylic acid-ethylene-vinyl acetate copolymer used in the emulsion (B), the ethylene content is 5 to 40% by weight, preferably 10 to 25% by weight. If the ethylene content is less than 5% by weight, the low-temperature adhesiveness decreases, and the film-forming temperature increases, resulting in poor film-forming properties. When the ethylene content is more than 40% by weight, the adhesiveness to various adherends is deteriorated, and the heat resistance is reduced.

The (meth) acrylic acid-ethylene-vinyl acetate copolymer used in the emulsion (B) has a (meth) acrylic acid content of 0.3 to 5% by weight, preferably 0.3 to 5% by weight. ３3% by weight. When the (meth) acrylic acid content is less than 0.3% by weight, the effect of improving adhesion, water resistance and heat resistance is insufficient, and the miscibility when mixed with the emulsion (C) described below is reduced. The mechanical and storage stability of both formulations is poor. When the (meth) acrylic acid content exceeds 5% by weight, the water resistance is reduced and the mechanical and storage stability of the emulsion (B) is deteriorated.

By using the copolymer containing (meth) acrylic acid, the emulsion (B)
A carboxyl group is introduced. By the introduction of such an acid group, the interaction between the copolymer in the emulsion (B) and the adherend becomes strong, so that the cohesive force increases, and the heat resistance and water resistance improve. . In addition, since the copolymer has an ionic group, ion shock at the time of mixing with another emulsion can be mitigated, so that miscibility is improved, storage stability, and mechanical and storage properties of the blend are improved. Stability is improved.

Further, by introducing an acid group into the emulsion (B), when a curing agent is blended in the emulsion (B), the acid group can be used as a crosslinking point, so that the coagulation of the cured product can be achieved. Strength is improved, and adhesiveness, heat resistance and water resistance are improved.

The above-mentioned ethylene-vinyl acetate copolymer or (meth) acrylic acid-ethylene-vinyl acetate copolymer may be copolymerized with another monomer, if necessary. Examples of the other monomer include acrylic acid 2
-Acrylates such as ethylhexyl, butyl acrylate and ethyl acrylate; methacrylates such as methyl methacrylate and butyl methacrylate; vinyl esters such as vinyl chloride and vinyl versatate; containing carboxyl groups other than (meth) acrylic acid In addition to the monomers, various monomers containing functional groups such as a sulfonic acid group, a hydroxyl group, an epoxy group, a methylol group, an amino group, and an amide group can be used.

Further, in order to improve the heat resistance and water resistance of the obtained adhesive composition, the toluene-insoluble content of the emulsion (A) or (B) is limited to 70% by weight or more.
It is preferably at least 80% by weight, more preferably at least 85% by weight.

The above-mentioned toluene-insoluble matter is a numerical value calculated according to the following definition for a film obtained by drying and removing water from an emulsion. The value of the toluene-insoluble component increases when the polymer structure has a crosslinked or branched structure or when the molecular weight increases, and generally the higher the value of the polymer, the denser the interaction between the molecules.
In particular, performance such as heat creep resistance is improved. Toluene insoluble matter (% by weight) = [(dry weight of insoluble resin after immersion in toluene) / (weight of resin before immersion in toluene)] × 1
00

The emulsion (A) or (B) preferably has a toluene swelling ratio of 2 to 30, more preferably 2 to 30.
~ 15. When the toluene swelling ratio is less than 2, the crosslinked structure becomes too strong and the wettability is reduced, so that the adhesion to the adherend is deteriorated. On the other hand, when the toluene swelling ratio exceeds 30, the crosslinked structure is too loose, so that heat resistance and water resistance are reduced.

The above-mentioned toluene swelling ratio is a numerical value often used as an index indicating the molecular weight between cross-linking points and the molecular weight between entanglement points. The larger the numerical value, the tighter the cross-linked structure or entangled structure. The toluene swelling ratio is calculated according to the following definition. Toluene swelling ratio =
(Wt weight of insoluble resin after immersion in toluene) / (weight of resin before immersion in toluene)

As the emulsifying and dispersing agent used when polymerizing the above emulsion (A) or (B), nonionic,
Examples thereof include anionic and cationic surfactants, which may be used alone or in combination of two or more. In addition, a reactive surfactant having a reactive double bond in the surfactant molecule; a water-soluble polymer such as polyvinyl alcohol and starch can also be used. Among these, use of a water-soluble polymer such as polyvinyl alcohol is particularly preferable.

It is preferable to use a water-soluble polymer such as polyvinyl alcohol among the above-mentioned surfactants, because the stability of the emulsion (A) or (B) at the time of roll application is improved. As the polyvinyl alcohol to be used, those having an average degree of saponification of 70 to 99.5 mol% and an average degree of polymerization of 200 to 3000 are preferable. When using polyvinyl alcohol as the emulsifying dispersant,
Other various surfactants and other water-soluble polymers may be used in combination.

Emulsion (C) used in the first invention
Is composed of a urethane resin, and a known urethane resin dispersion is used.

The content of the emulsion (C) insoluble in tetrahydrofuran (hereinafter referred to as THF) is preferably at least 10% by weight. The THF-insoluble content is a numerical value obtained according to the following definition for a film from which the emulsion (C) is dried to remove water. This THF-insoluble matter may cause the polymer structure to take a cross-linked or branched structure,
As the molecular weight increases, the numerical value increases. In general, the higher the numerical value, the denser the interaction between molecules, and the higher the performance such as heat creep resistance and the like. THF insoluble matter (% by weight) = [(dry weight of insoluble resin after immersion in THF) / (weight of resin before immersion in THF)] × 100

The emulsion (C) preferably has a THF swelling ratio of 2 to 70. When the THF swelling ratio is less than 2, the crosslinked structure becomes too strong and the wettability is reduced, so that the adhesion to the adherend is deteriorated. Also, TH
When the F swelling ratio exceeds 70, the crosslinked structure becomes too loose, so that heat resistance and water resistance are reduced.

The THF swelling ratio is a numerical value often used as an index indicating the molecular weight between cross-linking points and the molecular weight between entanglement points. The larger the numerical value, the tighter the cross-linked structure or entangled structure. The toluene swelling ratio is
It is calculated according to the following definition. THF swelling ratio = (undried weight of insoluble resin after immersion in THF) / (resin weight before immersion in THF)

The emulsion (C) can be produced, for example, by the method described in Japanese Patent Application No. 8-76501. That is, it can be produced by dispersing a polyurethane obtained by reacting a known polyisocyanate compound and a polyol compound with another compound, if necessary, in water.

The polyisocyanate compound used in the emulsion (C) is an organic polyisocyanate compound used in the production of ordinary urethane resins, for example, 1,4-tetramethylene diisocyanate, 1,6-hexaene. Methylene diisocyanate, 2,
2,4-trimethylhexamethylene diisocyanate,
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4'-diisocyanate, methylcyclohexyl-2,4-diisocyanate, methylcyclohexyl-
Aliphatic diisocyanates such as 2,6-diisocyanate, xylylenediisocyanate, 1,3-bis (isocyanate) methylcyclohexane, tetramethylxylylenediisocyanate, transcyclohexane-1,4-diisocyanate, and lysine diisocyanate;
2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, diphenylmethane-4,4'-
Aromatic diisocyanates such as diisocyanate, 1,5'-naphthene diisocyanate, tolidine diisocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,3-phenylene diisocyanate; lysine ester triisocyanate , Triphenylmethane triisocyanate, 1,
6,11-undecane triisocyanate, 1,8-isocyanate-4,4-isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate,
Bicycloheptane triisocyanate, adducts of trimethylolpropane and tolylenediisocyanate, triisocyanates such as adducts of trimethylolpropane and 1,6-hexamethylene diisocyanate, and the like, and these may be used alone. Well, two or more kinds may be used in combination.

The polyol compound used in the emulsion (C) is one having two or more hydroxyl groups in a molecule, which is used in the production of a usual urethane resin, and is, for example, ethylene glycol, diethylene glycol, propylene glycol. , 1,4-butanediol,
1,6-hexanediol, neopentyl glycol,
Polyhydric alcohols such as trimethylolpropane and glycerin; polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene ether glycol; adipic acid, sebacic acid, itaconic acid, maleic anhydride, terephthalic acid, isophthalic acid, and fumaric acid Acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, dicarboxylic acids such as azelaic acid and ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, Neopentyl glycol, 1,2-propanediol, 1,3-propanediol, 1,9-nonanediol, 3-methyl-1,5-
Polyester polyols obtained from polyol compounds such as pentanediol, 1,3-propanediol, tripropylene glycol, trimethylolpropane, and glycerin; polycaprolactone polyol, polyβ
Polylactone-based polyester polyols such as -methyl-δ-valerolactone; polybutadiene polyols or hydrogenated products thereof, polycarbonate polyols, polythioether polyols, and polyacrylate polyols.

The emulsion (C) can be produced from a urethane raw material by a known method such as an acetone method, a prepolymer mixing method, a ketimine method, and a hot melt dispersion method. The above emulsion (C)
When producing a compound, an active hydrogen-containing compound may be used in combination for the purpose of chain elongation or molecular weight control as necessary. Examples of such active hydrogen-containing compounds include polyamine compounds such as ethylenediamine, 1,4-butanediamine, and 1,6-hexanediamine; tertiary amine-containing polyhydric alcohols such as triethanolamine; methanol; Monoalcohols such as ethanol and butanol are exemplified.

The stability of the urethane resin used in the emulsion (C) when dispersed in water can be improved by introducing a hydrophilic group into the molecule during the production. Examples of the compound used for introducing a hydrophilic group include a sulfonic acid group, a carboxylic acid group, a nonionic hydrophilic group such as polyethylene glycol in the molecule, and a hydroxyl group, a primary amino group, a secondary amino group, and the like. A compound having one or more active hydrogens reactive with an isocyanate group is exemplified.

Examples of the above compounds include 3,4-diaminobutanesulfonic acid, 3,6-diamino-2-toluenesulfonic acid, 2,6-diaminobenzenesulfonic acid, and N- (2-aminoethyl) -2 Sulfonic acid-containing compounds such as -aminoethylsulfonic acid; 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid, 2,2-
Examples thereof include carboxylic acid-containing compounds such as dimethylol valeric acid, which may be used alone or in combination of two or more.

The polyurethane resin containing a hydrophilic group in a molecule obtained by using these hydrophilic group-containing compounds is called an ionomer structure, and has a surface activity itself. The emulsion can be emulsified without using a low-molecular hydrophilic additive such as an emulsifier, and thus the obtained emulsion has an advantage of having excellent water resistance.

In order to improve the surface activity, the hydrophilic group such as a sulfonic acid group or a carboxylic acid group introduced into the polyurethane resin is usually neutralized with a neutralizing agent, and the sulfonic acid group or the carboxylic acid group is neutralized. Is preferred.
Examples of the neutralizing agent used for this purpose include tertiary amine compounds such as triethylamine and trietalamine; inorganic alkali compounds such as sodium hydroxide; and ammonia.

The adhesive composition of the first invention is obtained by blending the emulsion (A) or (B) with the emulsion (C). In the adhesive composition, when the amount of the emulsion (C) is smaller, the adhesiveness and heat resistance are reduced, and the adhesiveness at low temperature is deteriorated. When the amount is larger than a certain amount, the adhesiveness and heat resistance are improved. Therefore, the amount of the emulsion (A) or (B) is preferably 3 to 150 parts by weight, more preferably 5 to 150 parts by weight.
１００100 parts by weight.

In the first invention, the method of blending the emulsion (A) or (B) with the emulsion (C) is not particularly limited, but generally, the two are adjusted so that their pH values are substantially the same, and then mixed. This is preferred because storage stability after mixing and stability during roll coating are improved. In practice, it is preferable that the pH value of the emulsion (A) or (B) is adjusted to the pH value of the emulsion (C) before mixing.

In general, the emulsion (C) exhibits alkalinity. If the emulsion (C) is adjusted to an acidic side, the stability of the emulsion (C) is remarkably reduced. Therefore, the pH of the emulsion (A) or (B) is adjusted to adjust the alkalinity. It is preferred that In order to adjust the pH of the emulsion (A) or (B) to alkaline, the emulsion (A) or (B) is stirred under a stirring condition with an appropriate amount of aqueous ammonia; an organic amine compound such as triethanolamine or triethylamine; An inorganic base such as sodium oxide and sodium bicarbonate is added.

In order to improve the storage stability of the adhesive composition and the stability during roll application, an additive for improving miscibility may be used. As such an additive, a surfactant such as an anionic surfactant, a nonionic surfactant, or an anion-nonionic surfactant may be used, and among these, a nonionic surfactant is particularly preferable.

The above adhesive composition is applied using an application device such as a roll coater, a flow coater, a knife coater, a spray coater and the like. When the adhesive composition is applied using a roll coater, the viscosity is preferably adjusted to 3000 to 100000 Cp, more preferably 5000 to 70000 Cp. When the viscosity is less than 3000 Cp, the adhesive easily flows, so that the adhesive flows out of the applicator at the time of roll application, and the workability deteriorates. On the other hand, if the viscosity exceeds 100,000 Cp, it becomes difficult to flow, so that the supply of the adhesive is inconvenient, and it is difficult to apply a uniform coating amount of the roll.

The thixotropic index, which is an index of the fluidity of the adhesive composition, is 2 to 1 when applied with a roll coater.
0 is preferable, and 2-7 are more preferable. The thixo index here is the ratio of the viscosity under high-speed shearing force to the viscosity under low-speed shearing force, and is a numerical value defined by the following equation. Thixo index = measured viscosity at 2 rpm / measured viscosity at 20 rpm

To adjust the viscosity within the above range, an organic solvent such as toluene or xylene may be added. Such an organic solvent is preferably used because it has an effect of not only adjusting the viscosity but also improving the film forming property at low temperatures. The amount of the organic solvent to be added is 1 to 100 parts by weight of the blend of the emulsion (A) or (B) and the emulsion (C).
10 parts by weight are preferred. If the addition amount is less than 1 part by weight, a sufficient thickening effect and the effect of improving the film forming property cannot be obtained, and if the addition amount exceeds 10 parts by weight, not only separation during storage or increase in viscosity, but also The work environment may be contaminated.

Examples of the viscosity improver include not only organic solvents but also known thickeners and viscosity improvers such as urethane nonionic thickeners, alkali thickener type anionic thickeners, and various water-soluble polymers. Agents may be used. Moreover, you may use together the said organic solvent and a thickener.

The solid content concentration of the adhesive composition is 30 to 7
The content is preferably adjusted to be 0% by weight, more preferably 35 to 55% by weight. If the solid concentration is less than 30% by weight, the amount of water becomes too large, and a long time is required for drying. Not only is the workability lowered, but also the transportation cost is increased and uneconomical. On the other hand, if the solid concentration exceeds 70% by weight, the mechanical stability at the time of applying the roll is reduced, and the workability is deteriorated. Further, the storage stability is reduced, and problems such as separation during storage occur. Not preferred.

Next, the second invention will be described. The adhesive composition of the second invention is the adhesive composition of the first invention, wherein the urethane resin used for the emulsion (C) is:
It has a polyester skeleton in the molecule and contains a sulfonic acid (salt) residue in the skeleton.

In order to introduce a polyester skeleton into the urethane resin molecule used in the emulsion (C), a polyester polyol is used as a polyol compound. By the introduction of the polyester skeleton, generally excellent adhesion to many types of adherends is expressed,
Further, the adhesion can be improved. Particularly, it is preferable because it exhibits excellent adhesiveness to a plastic material. Further, a polyol compound other than the polyester polyol may be used in combination as long as the advantage of the skeleton of the polyester is not impaired. Examples of such a polyol compound include the polyol compounds used in the first invention.

A sulfonic acid (salt) residue can be introduced into the urethane resin skeleton by using a compound having a sulfonic acid (salt) residue. The sulfonic acid group is
The effect of promoting the hydrolysis reaction on the ester bond such as a carboxylic acid group is small, so that the polyester main chain skeleton is hardly cut by water in the air or water penetrating into the bonding portion, etc. Excellent in water resistance and water resistance. In addition, since a strong hydrogen bond is formed in the adhesive layer, the heat resistance can be improved also by having a strong interaction between the polymer skeletons and forming a pseudo-crosslinked structure.

An inorganic filler containing 50% by weight or more of calcium carbonate may be added to the adhesive composition of the present invention. By adding an inorganic filler containing 50% by weight or more of calcium carbonate, excellent adhesion performance can be exhibited even if the adherend is a porous material.

Examples of the inorganic filler containing 50% by weight or more of calcium carbonate include known calcium carbonate-based fillers such as heavy calcium carbonate, colloidal light calcium carbonate, and surface-treated finely divided calcium carbonate. In addition to these calcium carbonate-based fillers, other inorganic-based fillers such as talc, clay, mica powder and silica such as silica sand may be used in combination. In this case, if the amount of the other inorganic filler is too large and the proportion of the calcium carbonate-based filler in all the fillers is less than 50% by weight, the viscosity of the adhesive composition increases and the structural viscosity increases. Is not preferred because it leads to a rise in

The amount of the inorganic filler containing 50% by weight or more of calcium carbonate is 1 part by weight per 100 parts by weight of the resin solid content of the emulsion (A) or (B) and (C).
The amount is preferably from 0 to 300 parts by weight, more preferably from 10 to 1 part by weight.
50 parts by weight. If the addition amount is less than 10 parts by weight, the effect of filling the unevenness of the base material is small, which does not lead to improvement in the adhesive strength. If the addition amount exceeds 300 parts by weight, the viscosity of the adhesive composition and the structural viscosity increase. Not only is it violent, but the ratio of the resin component effective for expressing the adhesive strength is too small, and the adhesive strength is rather reduced.

The adhesive composition of the present invention may contain, as a curing agent, a compound having two or more functional groups having a reactive activity to a carboxylic acid group and / or a sulfonic acid group in the molecule. .

Examples of the compound having two or more functional groups having a reaction activity for a carboxylic acid group and / or a sulfonic acid group in the molecule include, for example, isocyanate-based, melamine-based, aziridine-based, epoxy-based, and oxazoline-based compounds. ,
Known curing agents such as carbodiimide-based and various metal chelate type curing agents can be used. Of these, isocyanate-based, epoxy-based, and carbodiimide-based curing agents; and various metal chelate-type curing agents are particularly preferable.

As the isocyanate-based curing agent,
For example, diisocyanate compounds such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and hexamethylene diisocyanate (HDI); polyisocyanate compounds which are dimers, trimers, and multimers of the diisocyanate compounds; Modified isocyanate compounds and the like. Among these, those obtained by modifying the above polyisocyanate compound with a nonionic hydrophilic group such as polyethylene glycol are particularly preferable. A polyisocyanate compound modified by such a hydrophilic segment is called a water-dispersible isocyanate and is widely marketed as an aqueous curing agent.

Examples of the epoxy-based curing agent include compounds having two or more epoxy groups in the molecule. Examples of such an epoxy curing agent include bisphenol type epoxy compounds; phenol novolak type epoxy compounds; compounds containing tertiary amines such as N, N, N ', N'-tetraglycidyl-m-xylylenediamine. As such, an epoxy curing agent which does not itself have water solubility or strong hydrophilicity; a water-soluble epoxy curing agent modified with a hydrophilic segment; a bisphenol type epoxy compound or a phenol novolak type epoxy compound is forcibly forced by an emulsifier. A water-dispersed epoxy curing agent dispersed in water is exemplified, and any of them can be used.

Examples of the water-soluble epoxy curing agent include, for example, polypropylene glycol diglycidyl ether,
Polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcin diglycidyl ether, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, 1,6-hexane And diol diglycidyl ether.

As the carbodiimide-based curing agent, the general formula R ¹ -N = C = NR ² (wherein R ¹ and R ² represent a hydrogen atom, a propyl group, a cyclohexyl group or a p-toluoyl group) And the like. These carbodiimide-based curing agents are preferably modified into a form imparted with hydrophilicity, and are preferably diluted with water or a hydrophilic organic solvent at the time of addition.

Examples of the various metal chelate type curing agents include metal oxides such as zinc oxide, aluminum oxide and magnesium oxide; zinc, magnesium, iron, calcium, cobalt, copper, aluminum, molybdenum, vanadium, tin, and the like. Examples include acetylacetone complexes of various metal elements such as titanium.

The amount of the curing agent varies depending on the type of the curing agent, but is preferably 0.1 to 30 parts by weight based on 100 parts by weight of the total amount of the emulsion (A) or (B) and (C). More preferably, it is 0.3 to 10 parts by weight. These curing agents may be added immediately before use, or may be supplied in a state where they are added in advance. In particular, as long as the storage stability is good and the viscosity does not increase or gelation occurs, it is preferable to supply in a state where it is added in advance and use it as a one-component adhesive.

The adhesive composition of the present invention is applied to at least one of a porous material and a decorative surface sheet, and before the moisture in the applied adhesive composition of the present invention is completely dried,
The surface decorative material manufactured by bonding and pressing the porous material and the surface decorative sheet has excellent performance that can be suitably used in a wide range of applications such as building members used under severe environments. Have Particularly, in the case of an adhesive composition to which an inorganic filler containing 50% by weight or more of calcium carbonate is added, excellent effects are exhibited.

The porous material is not particularly limited.
For example, Rawan plywood, medium fiberboard (MDF, medium density fiberboard), particle board,
Wood material such as solid wood; cement board, gypsum board, A
Inorganic materials such as LC;

The surface decorative sheet is not particularly limited, and examples thereof include plastic material sheets such as hard or semi-hard vinyl chloride resin, polyolefin resin, and polyester resin; veneers made of wood processed into sheet form; Applied decorative paper.

The adhesive composition of the present invention may contain a solvent, a plasticizer, a fungicide, an antifoaming agent, a rust inhibitor, a filler,
Tackifiers and tackifiers may be added.

[0062]

The adhesive composition of the first invention comprises an emulsion (A) comprising an ethylene-vinyl acetate copolymer having a specific crosslinked structure and a specific molecular weight, or a carboxyl group derived from (meth) acrylic acid in a polymer molecule. Further, since the emulsion (B) composed of an ethylene-vinyl acetate copolymer having a specific cross-linked structure and a specific molecular weight is used, the adhesive layer has a high cohesive strength, and the emulsion composed of a urethane resin (C) ) Is excellent in adhesion to various adherends.

In the adhesive composition of the second invention, the urethane resin forming the emulsion (C) has a polyester skeleton and further has a sulfonic acid (salt) residue.
Excellent adhesion to various adherends, heat resistance and water resistance.

The adhesive composition of the fourth invention is excellent in heat resistance and water resistance because the urethane resin forming the emulsion (C) has a specific crosslinked structure or molecular weight.

The adhesive composition of the fifth invention is excellent in adhesive strength to a porous material in particular because an inorganic filler containing 50% by weight or more of calcium carbonate is added.

The adhesive composition according to the seventh aspect of the present invention contains a curing agent which reacts with an acid group, so that cohesive strength is improved, and heat resistance and water resistance are excellent.

[0067]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) Emulsion of ethylene-vinyl acetate copolymer ("Sumikaflex (hereinafter referred to as SF) 45" manufactured by Sumitomo Chemical Co., Ltd.) was used as emulsion (A).
5 ", an ethylene content of 18% by weight, a solid content concentration of 55% by weight, and a pH of 5), to which 25% by weight of aqueous ammonia was added to adjust the pH to 8.0. In addition, an emulsion of an aromatic urethane resin having a sulfonic acid group and a polyester skeleton as the emulsion (C) (“UX-306” manufactured by Sanyo Chemical Co., Ltd., solid content concentration 45% by weight, pH 8)
Was used. Next, 30 parts by weight of the emulsion (C) was added to 100 parts by weight of the emulsion (A) and mixed well, and then a thickener (Allied C) was added to adjust the viscosity.
alloys Limited “Viscalex”
AT-77 ") 0.2 parts by weight and sufficiently dispersed in 5 parts by weight of toluene were dispersed and added to the mixture of emulsions (A) and (C) to obtain an adhesive composition.

The toluene insoluble content of SF455 was measured by the following procedure. Emulsion (A) (SF455) was applied in a thin film having a thickness of about 1 mm, and dried in a blast drying oven at 40 ° C. for 24 hours to produce a dried film. About 0.5 g of the dried film section was immersed in about 50 ml of toluene, left standing at room temperature for 24 hours, and then the container was shaken lightly by hand, and the insoluble matter was immediately scooped with a 200-mesh stainless steel wire mesh. I took it. The wire mesh from which the insolubles had been scooped was placed on a paper waste for 30 seconds to absorb excess toluene and removed, and then the weight of the wire mesh together with the toluene swollen state was immediately measured. In addition, the wire mesh
It was left as it was in a drying oven at 110 ° C. for 4 hours to volatilize the toluene component, and the weight of the wire net was measured. The toluene insoluble content and the toluene swelling ratio were calculated by the following equations. Toluene insoluble matter (% by weight) = [(insoluble matter weight after toluene drying−weight of stainless steel wire mesh) / (resin weight before toluene immersion)] × 100 toluene swelling ratio = [(insoluble matter weight in toluene swelling state−
Weight of stainless steel mesh) / (weight of insoluble matter after drying in toluene-weight of stainless steel mesh)

The THF insoluble content of UX-306 and T
The HF swelling ratio was the same except that toluene was replaced by THF.
It was measured by the same procedure as the above-mentioned method for measuring the toluene insoluble content and the swelling ratio, and was calculated by the following formula. THF insoluble matter (% by weight) = [(weight of insoluble matter after drying in THF−weight of stainless steel wire mesh) / (weight of resin before immersion in THF)] × 100 THF swelling ratio = (weight of insoluble matter in THF swollen state−stainless steel wire mesh) Weight) / (insoluble matter weight after THF drying−weight of stainless steel wire mesh)

As a result of the above measurement, the insoluble content of toluene of SF455: 92% by weight, the swelling ratio of toluene: 9.3, UX-3
06 THF insolubles: 54% by weight, THF swelling ratio: 4
Three.

(Examples 2 to 4, Comparative Examples 1 to 3) SF455 or SF467 [emulsion (A)] and UX-306, HW-311 or U-
An adhesive composition was produced in the same manner as in Example 1 except that 42 [Emulsion (C)] was used. Note that S
F467, HW-311 and U-42 have the following properties. [Emulsion (A)] SF467: ethylene-vinyl acetate copolymer emulsion, manufactured by Sumitomo Chemical Co., Ltd., ethylene content: about 20% by weight, solids concentration: 65% by weight, pH 5, toluene-insoluble content: 29% by weight, toluene swelling ratio 43 [Emulsion (C)]-HW-311: carboxyl group-containing aromatic polyester skeleton urethane emulsion manufactured by Dainippon Ink and Chemicals, solids concentration 45% by weight, pH 8, THF insoluble content 0% by weight-U-42: Sumitomo Bayer Urethane emulsion, carboxyl group-containing aliphatic polyester skeleton urethane emulsion, solid concentration 49% by weight, pH 7, THF insoluble 88
Wt%, THF swelling ratio 5.0

With respect to the adhesive compositions obtained in the above Examples and Comparative Examples, the following performance evaluations were performed.
It was shown to. [Preparation of vinyl chloride decorative board sample] The obtained adhesive was uniformly applied to a 3 mm thick JAS1 Rawan plywood using a rubber roller so as to have an application amount of 100 g / m ² , and this adhesive was applied. 0.2 with woodgrain printing on the surface
After attaching a semi-rigid vinyl chloride decorative sheet having a thickness of mm, the layers were pressed together at room temperature and a pressure of 440 kg / m ² for 24 hours, laminated, and then left for 1 week at room temperature after decompression to cure. Then, a vinyl chloride decorative board sample was prepared.

(1) Normal Peeling Test The obtained decorative board sample was cut into a width of 25 mm,
A 180 ° peeling test was performed at a peeling speed of 200 mm / min under the atmosphere described above. (2) Water Resistance Peeling Test The obtained decorative board sample was cut into a 25 mm width,
Immersed in water for 24 hours, immediately without drying, immediately in a 20 ° C. atmosphere, peeling speed 200 mm / mi
n, a 180-degree peel test was performed. (3) Heat-resistant creep test The obtained decorative board sample was 25 mm (width) x 200 mm.
(Length), peeled off the vinyl chloride decorative sheet side 50 mm from the edge in the vertical direction, placed it horizontally, and placed the peeled vinyl chloride decorative sheet in a blow drying oven at 60 ° C. while keeping it hanging. After standing for 1 hour, a load of 500 g was applied to the tip of the peeled vinyl chloride decorative sheet, and the length of progress of peeling after 24 hours was measured. In this case, the shorter the peel length, the better the heat creep resistance.

[0075]

[Table 1]

Example 5 Emulsion of acrylic acid-ethylene-vinyl acetate copolymer (“Sumikaflex CY205” manufactured by Sumitomo Chemical Co., Ltd., acrylic acid content 0.8% by weight, ethylene content 18) as emulsion (B) Weight%, solid content concentration 55% by weight, pH 5)
The pH was adjusted to 8.0 by adding 5% by weight of aqueous ammonia. Further, an emulsion (B) of an aromatic urethane resin having a sulfonic acid group and having a polyester skeleton (“UX-306” manufactured by Sanyo Chemical Co., solid content concentration: 45% by weight, pH 8) was used as the emulsion (C). 10
To 0 parts by weight, 30 parts by weight of the emulsion (C) was added and mixed well. Then, for viscosity adjustment, a thickener (A
"V" manufactured by Llied Colloids Limited
iscalexAT-77 ") was added to a mixture of emulsions (B) and (C), in which 0.2 parts by weight and 5 parts by weight of toluene were sufficiently stirred and dispersed to obtain an adhesive composition.

(Examples 6 to 8) C of the compounding amount shown in Table 2
An adhesive composition was produced in the same manner as in Example 5, except that Y205 or SF467 [emulsion (B)] and UX-306, HW-311 or U-42 [emulsion (C)] were used.

The CY205 has the following properties. CY205: toluene insoluble content 91% by weight, toluene swelling ratio 7.2, THF insoluble content 54% by weight, THF swelling ratio 4
3

For the adhesive compositions obtained in the above Examples 5 to 8, a vinyl chloride decorative board sample was prepared in the same manner as in Example 1, and the obtained sample was used in the same manner as in Example 1. The performance evaluations of (1) to (3) were performed, and the results are shown in Table 2.

[0080]

[Table 2]

Example 9 100 parts by weight of a mixture of the emulsions (A) and (C) prepared in the same manner as in Example 1 was used as a curing agent as a water-soluble epoxy curing agent (“Denacol” manufactured by Nagase Kasei Co., Ltd.). EX-614B ", sorbitol polyglycidyl ether) (2 parts by weight), and mixed and stirred well to produce an adhesive composition.

(Examples 9 to 22, Comparative Examples 4 to 11) Table 3
SF467, OM4000 or E of the compounding amount shown in
Except for using P11 [emulsion (A)], CY205 [emulsion (B)] and HW-311 or U-42 [emulsion (C)], and a curing agent,
An adhesive composition was produced in the same manner as in Example 9.

In Tables 3 to 7, the following properties were used. [Emulsion] ・ OM4000: “Panflex OM-4” manufactured by Kuraray
000 ", ethylene-vinyl acetate copolymer emulsion, solid content concentration 65% by weight, pH 5, toluene insoluble content 5
9% by weight, toluene swelling ratio 12 EP11: "Evadic EP-1" manufactured by Dainippon Ink and Chemicals, Inc.
1 ", ethylene-vinyl acetate copolymer emulsion, solid content concentration 53% by weight, pH 4, toluene insoluble content 63% by weight, toluene swelling ratio 10

[Curing agent] Denacol EX-313: a glycerol polyglycidyl ether, water-soluble epoxy curing agent manufactured by Nagase Kasei Co., Ltd. Denacol EM-125: a cresol novolac epoxy compound emulsion, solid content concentration, manufactured by Nagase Kasei Co., Ltd. 25% by weight ・ Denacol EX-1101: Emulsion of modified bisphenol A type epoxy compound, manufactured by Nagase Kasei Co., Ltd., solid content concentration: 50% by weight ・ TETRAD-X: Manufactured by Mitsubishi Gas Chemical Company, N, N,
N ', N'-tetraglycidyl-m-xylylenediamine ・ Esdine UX-W: Water-dispersible isocyanate-based curing agent manufactured by Sekisui Chemical Co., Ltd. ・ UCARLNK XL-25SE: A carbodiimide-based curing agent manufactured by Sunker Co. (USA) Organic solvent solution, solid content concentration 50% by weightCarbodilite V-06: Nisshinbo Co., Ltd., aqueous solution of carbodiimide-based curing agent, solid content concentration 40% by weight

For the adhesive compositions obtained in Examples 9 to 20 and Comparative Examples 4 to 11, a vinyl chloride decorative board sample was prepared in the same manner as in Example 1, and the obtained sample was used. The same performance evaluations (1) to (3) as in Example 1 were performed, and the results are shown in Tables 3 to 7.

[0086]

[Table 3]

[0087]

[Table 4]

[0088]

[Table 5]

[0089]

[Table 6]

[0090]

[Table 7]

(Example 23) SF455 was used as the emulsion (A), and 25% by weight of aqueous ammonia was added to adjust the pH to 8.0. Further, 0.5 parts by weight of Sammorin OT-70 (manufactured by Sanyo Chemical Industries, solid content concentration: 70% by weight) was added as a mixing stabilizer to 100 parts by weight of the pH-adjusted emulsion (A). next,
30 parts by weight of UX-306 as emulsion (C) was added to 100 parts by weight of emulsion (A) and mixed well. Then, for viscosity adjustment, a thickener (All
"Vis" manufactured by ied Colloids Limited
calex AT-77 ") 0.1 parts by weight of toluene 5
The mixture which was sufficiently stirred and dispersed in parts by weight was added to the mixture of the emulsions (A) and (C).

Next, calcium carbonate grade 1 (manufactured by Sankyo Flour Mill, general heavy calcium carbonate) was used as an inorganic filler with respect to 100 parts by weight of the mixture of emulsions (A) and (C).
20 parts by weight (29 parts by weight based on 100 parts by weight of the resin solids in the emulsion thus far) were blended to prepare an adhesive composition. The compounding method is such that the mixture of the emulsions (A) and (C) is stirred with a homodisper, the inorganic filler is gradually added thereto, and stirring is continued for 30 minutes after the addition is completed. went.

(Examples 24-26, Comparative Example 12) SF455 [Emulsion (A)], U
X-306 or HW-311 [emulsion (C)],
Example 2 except that an inorganic filler was used.
In the same manner as in Example 3, an adhesive composition was produced. The following fillers were used as the inorganic filler.

[Inorganic filler]-Calcium carbonate 1st grade: General-purpose heavy calcium carbonate manufactured by Sankyo Milling Co., Ltd.-SCP-E # 110: Sankyo Milling Co., Ltd., fatty acid surface-treated heavy calcium carbonate-Shuplex: Sanyo Trading Company-made, clay-based filler

For the adhesive compositions obtained in Examples 23 to 26 and Comparative Example 12, a vinyl chloride decorative board sample was prepared in the same manner as in Example 1, and the obtained sample was used to carry out The same performance evaluations (1) to (3) as in Example 1 were performed, and the results are shown in Table 8. Further, the coating workability (4) of the obtained adhesive composition was also evaluated by the following method.

(4) Coating workability The obtained adhesive composition was applied to a 30 cm square JAS1 type Rawan plywood using a rubber roller in an amount of 100 g.
/ M ² , and roll sensory properties and elongation on Rawan plywood were organoleptically evaluated. In addition, both the roll separation property and the elongation on the Rawan plywood were determined by a three-point method in which three points were good, two points were normal, and one point was bad.

[0097]

[Table 8]

(Example 27) SF455 was used as the emulsion (A), and 25% by weight of aqueous ammonia was added to adjust the pH to 8.0. Further, 0.5 parts by weight of Sammorin OT-70 (manufactured by Sanyo Chemical Industries, solid content concentration: 70% by weight) was added as a mixing stabilizer to 100 parts by weight of the pH-adjusted emulsion (A). next,
30 parts by weight of UX-306 as emulsion (C) was added to 100 parts by weight of emulsion (A) and mixed well. Then, for viscosity adjustment, a thickener (All
"Vis" manufactured by ied Colloids Limited
calex AT-77 ") 0.1 parts by weight of toluene 5
The mixture which was sufficiently stirred and dispersed in parts by weight was added to the mixture of the emulsions (A) and (C).

Next, calcium carbonate first grade (general-purpose heavy calcium carbonate, manufactured by Sankyo Flour Milling Co., Ltd.) was used as an inorganic filler for 100 parts by weight of the mixture of the emulsions (A) and (C).
20 parts by weight (29 parts by weight based on 100 parts by weight of the resin solids in the emulsion thus far) were blended to prepare an adhesive composition. The compounding method is such that the mixture of the emulsions (A) and (C) is stirred with a homodisper, the inorganic filler is gradually added thereto, and stirring is continued for 30 minutes after the addition is completed. went. To 100 parts by weight of the adhesive composition thus obtained, 2.0 parts by weight of EX-614B was added as a curing agent, and the mixture was well mixed and stirred.

(Examples 28 to 32, Comparative Examples 13 and 14)
Example 27 except that SF455 or SF467 [emulsion (A)], UX-306 or HW-311 [emulsion (C)], a curing agent, and an inorganic filler of the blending amounts shown in Table 9 were used. In the same manner as in the above, an adhesive composition was produced.

Examples 27 to 32 and Comparative Examples 13, 1
For the adhesive composition obtained in 4, a vinyl chloride decorative board sample was prepared in the same manner as in Example 1, and (1) to (3) similar to those in Example 1 using the obtained sample.
Was performed, and the results are shown in Table 9. Further, the coating workability (4) of the obtained adhesive composition was evaluated in the same manner as in Example 23, and shown in Table 9.

[0102]

[Table 9]

[0103]

The adhesive composition of the present invention has the above-mentioned composition, and has excellent adhesiveness, high cohesive strength, and excellent heat resistance and water resistance. A surface decorative material obtained by laminating a decorative sheet on the surface of a wood material, a building material, a furniture material, or the like using the above-mentioned adhesive composition is excellent in heat resistance and water resistance, and thus can be applied to a wide range of uses.

Claims (7)

[Claims] 1. An emulsion comprising (A) an ethylene-vinyl acetate copolymer having a toluene-insoluble content of 70% by weight or more and an ethylene content of 5 to 40% by weight, or (B)
A toluene-insoluble content is 70% by weight or more, a (meth) acrylic acid content of 0.3 to 5% by weight and an ethylene content of 5 to 5%.
An adhesive composition comprising 40% by weight of an emulsion composed of (meth) acrylic acid-ethylene-vinyl acetate copolymer and (C) an emulsion composed of urethane resin. 2. The adhesive according to claim 1, wherein the emulsion (C) is formed of a urethane resin having a polyester skeleton in the molecule and containing a sulfonic acid (salt) residue in the skeleton. Composition. 3. Emulsion (C) is added to 100 parts by weight of emulsion (A) or emulsion (B).
The adhesive composition according to claim 1 or 2, wherein the adhesive composition is blended in an amount of from 150 to 150 parts by weight. 4. The adhesive composition according to claim 1, wherein the content of tetrahydrofuran insoluble in the emulsion (C) is 10% by weight or more. 5. The adhesive composition according to claim 1, wherein an inorganic filler containing 50% by weight or more of calcium carbonate is added. 6. The resin solid content of the emulsion (A) or the emulsion (B) and the emulsion (C) is 100.
The adhesive composition according to claim 5, wherein the inorganic filler is added in an amount of 10 to 300 parts by weight based on part by weight. 7. The curing agent according to claim 1, wherein a compound having two or more functional groups having a reaction activity for a carboxylic acid group and / or a sulfonic acid group in the molecule is added. The adhesive composition according to claim 2, claim 3, claim 4, claim 5, or claim 6.