JP2005139266A - Copolymer latex for adhesive and adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copolymer latex which largely improves the pot lives of aqueous polymer isocyanate-based adhesives and is used for the aqueous polymer isocyanate-based adhesives having excellent adhesive performance balances. <P>SOLUTION: This copolymer latex for the aqueous polymer isocyanate-based adhesives is prepared by emulsion-copolymerizing 20 to 60 wt. % of an aliphatic conjugated diene-based monomer with 80 to 40 wt. % of another vinylic monomer capable of copolymerizing with the same in the presence of an emulsifier comprising the monovalent cation salt of a polyaromatic compound polysulfonate having two or more aromatic rings whose at least one has an aliphatic hydrocarbon group as a substituent, in the molecule. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a copolymer latex for an aqueous polymer isocyanate-based (aqueous vinyl urethane) adhesive, and an adhesive containing the same, which can be suitably used mainly for adhesion of wood.

Conventionally, adhesives mainly composed of formaldehyde condensation type thermosetting resins such as urea resins, melamine resins, phenol resins, and resorcinol resins have been used as adhesives for wood. On the other hand, an aqueous polymer isocyanate-based (aqueous vinyl urethane) adhesive has been developed (Patent Document 1: Japanese Patent Publication No. 51-30576), and in recent years due to its excellent adhesive strength and the feature of not using formaldehyde, Used in large quantities.
This water-based polymeric isocyanate-based adhesive is a type of adhesive in which a water-soluble polymer / water-based emulsion compound as a main agent and an isocyanate compound as a curing agent are mixed immediately before use. Polyvinyl alcohol is mainly used as the molecule, and (ethylene) vinyl acetate emulsion, styrene-butadiene copolymer latex, and acrylic emulsion are usually used as the aqueous emulsion. These water-based emulsions are used in combination with water-soluble polymers for the purpose of improving the adhesive strength, but when these are selected and blended, particularly those that are effective in improving the water-resistant adhesive strength, the main agent is stored. It is difficult to ensure viscosity stability at the time (hereinafter referred to as storage stability), or the reaction proceeds immediately after mixing the isocyanate compound of the curing agent, so the pot life (hereinafter pot life) This often causes problems in practicality as an adhesive.

In particular, with the recent expansion of the use of water-based polymeric isocyanate adhesives, there is an increasing need to adjust the adhesive by mixing the main agent and curing agent at once on a relatively large batch scale. Since the time from the mixing of the main agent and the curing agent to the time when the adhesive is applied and used becomes longer, further improvement of the pot life is required.
As means for solving these problems, for example, Patent Document 2 (Japanese Patent Laid-Open No. 59-59768) discloses a method using a copolymer latex having a large particle size and Patent Document 3 (Japanese Patent Laid-Open No. 05-331440). As can be seen, a method using a copolymer latex using a specific surfactant has been proposed.
However, the pot life improvement effect by these methods is not sufficient for recent needs, and further improvement of the pot life has been expected.

Japanese Patent Publication No.51-30576 JP 59-59768 A JP 05-331440 A

  An object of the present invention is to provide a copolymer latex for an aqueous polymer isocyanate-based adhesive that greatly improves the pot life of the aqueous polymer isocyanate-based adhesive and has an excellent adhesion performance balance.

The present invention solves the above-mentioned problems, and is characterized in that a copolymer latex using a specific emulsifier is used as a copolymer latex for an aqueous polymer isocyanate-based (aqueous vinyl urethane) adhesive. It is.

By using the copolymer latex of the present invention as a copolymer latex for an aqueous polymer isocyanate-based (aqueous vinyl urethane) adhesive, the pot life is greatly improved as compared with conventional ones, and excellent Adhesive performance balance can be obtained.

That is, the present invention provides a monovalent cation of a polyaromatic compound polysulfonate having two or more aromatic rings in one molecule and at least one of the aromatic rings having an aliphatic hydrocarbon group as a substituent. An aqueous polymer obtained by emulsion polymerization of 20 to 60% by weight of an aliphatic conjugated diene monomer and 80 to 40% by weight of another vinyl monomer copolymerizable therewith using an emulsifier composed of a salt. The present invention provides a copolymer latex for an isocyanate-based adhesive.

Hereinafter, the present invention will be described in detail.
Monovalent cation of polyaromatic compound polysulfonate having two or more aromatic rings in one molecule used in the present invention, at least one of which has an aliphatic hydrocarbon group as a substituent In an emulsifier composed of a salt (hereinafter abbreviated as an emulsifier of the present invention), examples of the aromatic ring include a benzene ring and a naphthalene ring. The aromatic ring is a benzene ring as an aliphatic hydrocarbon group which is a substituent of the aromatic ring. In this case, a linear or branched monovalent aliphatic hydrocarbon group having 8 to 14 carbon atoms is preferable. When the aromatic ring is a naphthalene ring, a linear or branched monovalent aliphatic carbon group having 1 to 4 carbon atoms A hydrogen group is preferred. The polyaromatic compound has two or more, preferably 2 to 10, aromatic rings as described above in one molecule. Specifically, the aromatic compound has an aliphatic hydrocarbon group as a substituent. An ether compound obtained by etherification of an aromatic compound having an aliphatic hydrocarbon group as a substituent with another compound and another aromatic compound, an aromatic compound having an aliphatic hydrocarbon group as a substituent, and formaldehyde A condensed formalin condensate, a formalin cocondensate obtained by co-condensing an aromatic compound having an aliphatic hydrocarbon group as a substituent, another aromatic compound and formaldehyde, and the like can be given.
The monovalent cation salt is preferably an alkali metal salt such as sodium or potassium; an ammonium salt; or an amine salt such as alkanolamine.

Especially as the emulsifier of the present invention, a salt of alkyldiphenyl ether disulfonate (“PEX SSL”, “PEX SSH” manufactured by Kao Corporation, “New Coal 271A” manufactured by Nippon Emulsifier Co., Ltd., “DOWFAX 2A1” manufactured by Dow Chemical Co., Ltd.) Available), salt of formalin condensate of β-naphthalenesulfonic acid (available as “Demol NL” manufactured by Kao Corporation), salt of formalin cocondensate of butylnaphthalenesulfonic acid and naphthalenesulfonic acid (“Demol manufactured by Kao Corporation”) SNA ”and a salt of methyl naphthalene sulfonic acid formalin condensate (available as“ Demol MS ”manufactured by Kao Corporation), and the like, and most preferably a salt of alkyl diphenyl ether disulfonate. These may be used alone or in combination of two or more.

  Further, the emulsifier of the present invention and other emulsifiers such as sulfates of higher alcohols, alkylbenzene sulfonates, aliphatic sulfonates, aliphatic carboxylates, sulfate salts of nonionic surfactants and the like It is also possible to use a nonionic surfactant such as an alkyl ester type of polyethylene glycol, an alkyl ester type of alkyl glycol, an alkyl phenyl ether type or an alkyl ether type. However, in order to keep the effect of the present invention sufficiently high, the amount of other emulsifiers used must be 50% by weight or less, preferably 30% by weight or less based on the total emulsifier.

The use amount of the emulsifier of the present invention (or the total emulsifier in which other emulsifiers used in combination) is combined is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 7 parts by weight, Most preferably, it is 0.2 to 3 parts by weight. If the amount of the emulsifier used is less than 0.05 parts by weight based on the total amount of the monomers, the stability of the copolymer latex is insufficient, and a storage stable adhesive cannot be obtained, and more than 10 parts by weight. When it increases, the water resistance of the adhesive tends to decrease.

The monomer constituting the copolymer latex of the present invention is composed of an aliphatic conjugated diene monomer and another vinyl monomer copolymerizable therewith.

Aliphatic conjugated diene monomers include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, substituted Examples thereof include linear conjugated pentadienes, substituted and side chain conjugated hexadienes, and one or more kinds can be used. 1,3-butadiene is particularly preferable.

  The amount of the aliphatic conjugated diene monomer used is required to be 20 to 60% by weight with respect to the total monomers constituting the copolymer latex of the present invention. When the amount of the aliphatic conjugated diene monomer used is less than 20% by weight, the flexibility of the obtained adhesive is lowered, the repeated heat resistance of the adhesive is lowered, and when it exceeds 60% by weight, the water resistance of the obtained adhesive is reduced. Is unfavorable because of lowering.

Other copolymerizable vinyl monomers include unsaturated carboxylic acid alkyl ester monomers, aromatic vinyl monomers, vinyl cyanide monomers, and ethylenically unsaturated carboxylic acid monomers. And unsaturated monomers containing a hydroxyalkyl group, unsaturated carboxylic acid amide monomers, and the like.

Unsaturated carboxylic acid alkyl ester monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, glycidyl methacrylate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl maleate, dimethyl itaconate , Monomethyl fumarate, monoethyl fumarate, 2-ethylhexyl acrylate and the like, and one kind or two or more kinds can be used. Particularly preferred is methyl methacrylate.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, methyl α-methylstyrene, vinyltoluene, divinylbenzene, and the like, and one or more can be used. Styrene is particularly preferable.

Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile and the like, and one or more can be used. Particularly preferred is acrylonitrile.

Examples of the ethylenically unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid and the like, and one or more of them can be used.

Examples of unsaturated monomers containing hydroxyalkyl groups include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, 3-chloro-2-hydroxy Propyl methacrylate, di- (ethylene glycol) maleate, di- (ethylene glycol) itaconate, 2-hydroxyethyl maleate, bis (2-hydroxyethyl) maleate, 2-hydroxyethyl methyl fumarate and the like. Two or more kinds can be used. In particular, β-hydroxyethyl acrylate is preferable.

Examples of unsaturated carboxylic acid amide monomers include acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N, N-dimethylacrylamide, and the like, and one or more of them can be used. Particularly preferred is (meth) acrylamide.

In addition to the above monomers, fatty acid vinyl esters such as vinyl acetate and vinyl propionate, aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 2-vinylpyridine Basic monomers such as 4-vinylpyridine, vinyl chloride, vinylidene chloride and the like can be used.

In the present invention, the monomer constituting the copolymer latex is particularly 20 to 60% by weight of an aliphatic conjugated diene monomer, 10 to 50% by weight of an unsaturated carboxylic acid alkyl ester monomer, and It is preferable from the viewpoint of the storage stability of the adhesive that it consists of 70 to 0% by weight of other vinyl monomers copolymerizable therewith.

Although there is no restriction | limiting in particular about the number average particle diameter of the copolymer latex in this invention, It is preferable that it is the range of 70-300 nm from a viewpoint of the water resistant strength expression of an adhesive agent. More preferably, it is 100-200 nm.
The number average particle diameter can be measured by a dynamic light scattering method (LPA-3000 / 3100 (manufactured by Otsuka Electronics) was used for the measurement).

The addition method of various components in the present invention is not particularly limited, and any of a batch addition method, a divided addition method, and a continuous addition method can be adopted. Also, the emulsion polymerization method is not particularly limited, and any one-stage polymerization, two-stage polymerization, multistage polymerization or the like can be employed. Further, in the emulsion polymerization, conventional chain transfer agents, emulsifiers, protective colloids, polymerization initiators, hydrocarbon solvents, electrolytes, polymerization accelerators, chelating agents and the like can be used.

Such chain transfer agents include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-stearyl mercaptan, dimethylxanthogen disulfide, diisopropylxanthogen. Xanthogen compounds such as disulfide, α-methylstyrene dimer, terpinolene, thiuram compounds such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide, 2,6-di-t-butyl-4-methylphenol , Phenolic compounds such as styrenated phenol, allyl compounds such as allyl alcohol, halogenated charcoal such as dichloromethane, dibromomethane, carbon tetrabromide Hydrogen compounds, α-benzyloxystyrene, α-benzyloxyacrylonitrile, vinyl ethers such as α-benzyloxyacrylamide, triphenylethane, pentaphenylethane, acrolein, methacrolein, thioglycolic acid, thiomalic acid, 2-ethylhexylthioglycolate Can be used, and one or more can be used.
There is no limitation on the amount of these chain transfer agents used, and the amount can be appropriately adjusted according to the performance required for the copolymer latex, but preferably 0 to 10 parts by weight with respect to 100 parts by weight of the monomer mixture. It is.

As the protective colloid, polyvinyl alcohol-based partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol and derivatives of polyvinyl alcohol, or cellulose-based hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose and the like are used.

As the polymerization initiator, water-soluble initiators such as potassium persulfate, ammonium persulfate, and sodium persulfate, redox initiators, and oil-soluble initiators such as benzoyl peroxide can be used.

Examples of hydrocarbon solvents include saturated hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, cycloheptane, pentene, hexene, heptene, cyclopentene, cyclohexene, cycloheptene, 4-methylcyclohexene, 1-methylcyclohexene, etc. Examples thereof include hydrocarbon compounds such as unsaturated hydrocarbons, aromatic hydrocarbons such as benzene, toluene and xylene.

The adhesive of the present invention comprises a main component composed of the copolymer latex and a water-soluble polymer and an isocyanate compound as a crosslinking agent.

As the polyvinyl alcohol which is a water-soluble polymer, usual partially saponified polyvinyl alcohol, completely saponified polyvinyl alcohol and derivatives of polyvinyl alcohol are used. The polymerization degree of polyvinyl alcohol is preferably 300 to 2500, and the saponification degree is preferably 80 to 100%.

The blending amount of the water-soluble polymer is preferably 5 to 200 parts by weight, more preferably 30 to 160 parts by weight with respect to 100 parts by weight of the copolymer latex (solid content). If the water-soluble polymer is less than 5 parts by weight, the initial adhesiveness is insufficient, and if it exceeds 200 parts by weight, the storage stability is lowered, which is not preferable.

The isocyanate compound that is a crosslinking agent may be any compound containing two or more isocyanate groups in the molecule, such as tolylene diisocyanate and its hydride, trimethylolpropane-tolylene diisocyanate adduct, triphenylmethane triisocyanate, Polyisocyanates such as diphenylmethane diisocyanate and its hydride and hexamethylene diisocyanate addition condensate can be mentioned, among which trimethylolpropane-tolylene diisocyanate adduct, diphenylmethane diisocyanate and its polymer are preferable. Further, a mixing method of polyisocyanate and polyol, that is, a mixture of the above-mentioned isocyanate compound in a polyol such as polyester may be used. Further, an NCO-terminated prepolymer prepolymerized with a polyol and an excess of polyisocyanate may be used, and an excess of the above polyisocyanate is added to an OH-terminated prepolymer previously polymerized with an excess of polyol. It may be added.

The blending amount of the isocyanate compound is preferably 10 to 250 parts by weight, more preferably 30 to 200 parts by weight, based on 100 parts by weight of the copolymer latex (solid content) of the present invention. If the isocyanate compound is less than 10 parts by weight, the initial adhesive strength and water resistance are insufficient, and if it exceeds 250 parts by weight, the pot life becomes too short.

A bulking agent and a filler can be mix | blended with the adhesive agent of this invention. Examples of these extenders and fillers include wheat flour, starches, defatted soy flour, wood flour, clay, calcium carbonate, talc, titanium oxide and the like. These fillers and fillers are preferably 10 to 400 parts by weight, more preferably 30 to 300 parts by weight, based on 100 parts by weight of the copolymer latex (solid content) of the present invention. Furthermore, a thickener, a dispersant, a penetrating agent, an antifoaming agent, an antiseptic, an antifungal agent, a solvent, a color pigment, and the like can be added as necessary.

The adhesive of the present invention is suitable for bonding wood materials such as plywood, LVL, veneer, decorative board, laminated wood, particle board, etc., and paper, cloth, metal, ceramics, glass, various plastics, inorganic / cement The present invention can also be applied to bonding or coating between the same or different types of plate-like or fibrous materials made of.

Hereinafter, in order to clearly show the excellent effects of the present invention, examples and comparative examples will be given to describe the present invention more specifically. However, the present invention is not limited to these examples unless it exceeds the gist. It is not limited. In addition, the part and% shown in an Example and a comparative example are based on a weight unless there is particular notice.

Production of copolymer latex (a) In a 10 liter autoclave, 100 parts of water, 4.6 parts of 1,3-butadiene, 5.8 parts of methyl methacrylate, 0.4 part of methacrylic acid, and itaconic acid 1 Part, sodium salt of alkyl diphenyl ether disulfonate (Perox SSL manufactured by Kao Corporation) 0.5 part, 0.3 parts of t-dodecyl mercaptan, 0.5 part of potassium persulfate was heated to 65 ° C. with sufficient stirring. For 1 hour, and then a mixture of 36.54 parts of 1,3-butadiene, 52.2 parts of methyl methacrylate, and 0.5 part of a sodium salt of alkyldiphenyl ether disulfonate (Perex SSL, manufactured by Kao Corporation) for 6 hours. Then, the polymerization reaction was completed by maintaining the temperature at 65 ° C. for another 8 hours. Subsequently, an aqueous caustic soda solution was added to adjust the pH to 6, and unreacted monomers and the like were removed by steam distillation to obtain a copolymer latex (a). The number average particle diameter of the copolymer latex (a) was 180 nm.

Production of copolymer latex (b) In a 10 liter autoclave, 100 parts of water, 4 parts of 1,3-butadiene, 6 parts of methyl methacrylate, sodium salt of alkyldiphenyl ether disulfonate (Perox SSL manufactured by Kao Corporation) ) 0.5 part, sodium salt of β-naphthalenesulfonic acid formalin condensate (Demol NL manufactured by Kao Corporation) 0.7 part, 0.3 part of t-dodecyl mercaptan, 0.5 part of potassium persulfate Then, the temperature was raised to 65 ° C. and reacted for 1 hour, and then the temperature was raised to 70 ° C., 36 parts of 1,3-butadiene, 54 parts of methyl methacrylate, polyoxyethylene alkyl ether (Emulgen 120 manufactured by Kao Corporation) A mixture consisting of 0 parts was continuously added in 5 hours, and then the temperature was kept at 70 ° C. for 6 hours to complete the polymerization reaction. Subsequently, 0.2 part of sodium salt of alkyldiphenyl ether disulfonate (Perox SSL manufactured by Kao Corporation) is added, pH is adjusted to 8 by addition of aqueous caustic soda, and unreacted monomers are removed by steam distillation. Thus, copolymer latex (b) was obtained. The number average particle diameter of the copolymer latex (b) was 120 nm.

Production of copolymer latex (c) In a 10 liter autoclave, 100 parts of water, 3.0 parts of 1,3-butadiene, 2.8 parts of methyl methacrylate, 0.7 part of styrene, 0.35 of acrylonitrile Parts, 0.5 parts of hydroxyethyl acrylate, 0.5 parts of itaconic acid, 0.4 parts of sodium dodecylbenzenesulfonate, 0.5 parts of t-dodecyl mercaptan, 1 part of potassium persulfate and 2 parts of cyclohexene However, after raising the temperature to 70 ° C., 40 parts of 1,3-butadiene, 37.2 parts of methyl methacrylate, 9.3 parts of styrene, 4.65 parts of acrylonitrile, 1 part of acrylic acid, sodium of β-naphthalenesulfonic acid formalin condensate A mixture consisting of 1 part of salt (Demol NL manufactured by Kao Corporation) was continuously added in 6 hours and kept at 70 ° C. for 6 hours. The reaction was completed. Next, 1 part of sodium salt of β-naphthalenesulfonic acid formalin condensate (Demol NL manufactured by Kao Corporation) is added, adjusted to pH 8 by addition of aqueous caustic soda, and unreacted monomers are removed by steam distillation. As a result, a copolymer latex (c) was obtained. The number average particle diameter of the copolymer latex (c) was 190 nm.

Production of copolymer latex (d) In a 10 liter autoclave, 100 parts of water, 4 parts of 1,3-butadiene, 5.8 parts of styrene, 1 part of itaconic acid, sodium dodecylbenzenesulfonate 0.5 Part, t-dodecyl mercaptan 0.45 part, potassium persulfate 1.5 part, cyclohexene 3 part, heated to 70 ° C. with sufficient stirring and reacted for 1 hour, 36 parts of 1,3-butadiene, styrene 52 A mixture comprising 2 parts, 1 part of acrylic acid and 1 part of sodium salt of alkyl diphenyl ether disulfonate (Perox SSL manufactured by Kao Corporation) was continuously added in 8 hours, and the polymerization reaction was completed by maintaining at 70 ° C. for 8 hours. . Subsequently, 1 part of sodium salt of β-naphthalene sulfonic acid formalin condensate (Demol NL manufactured by Kao Corporation) is added, pH is adjusted to 7 by adding aqueous caustic soda, and unreacted monomers are removed by steam distillation. Thus, a copolymer latex (d) was obtained. The number average particle diameter of the copolymer latex (d) was 170 nm.

Production of copolymer latex (e) Into a 10 liter autoclave, 100 parts of water, 3.65 parts of 1,3-butadiene, 6.2 parts of styrene, sodium alkyl sulfate (Taikalite N1230, manufactured by Teika Co., Ltd.) ) 0.3 part, 0.4 part of t-dodecyl mercaptan and 1 part of potassium persulfate, with sufficient stirring, heated to 65 ° C. and reacted for 1 hour, 32.85 parts of 1,3-butadiene, 55 of styrene 8 parts, 1.5 parts of hydroxyethyl acrylate, and 1 part of sodium salt of alkyl diphenyl ether disulfonate (Perox SSL manufactured by Kao Corporation) are continuously added in 7 hours, and the polymerization reaction is further maintained at 65 ° C. for 6 hours. Completed. Subsequently, 0.7 parts of sodium alkyl sulfate (Taikalite N1230 manufactured by Teika Co., Ltd.) was added, the pH was adjusted to 9 by adding an aqueous solution of caustic soda, and unreacted monomers were removed by steam distillation to co-polymerize. Combined latex (e) was obtained. The number average particle diameter of the copolymer latex (e) was 190 nm.

Production of copolymer latex (f) In a 10 liter autoclave, 100 parts of water, 4.5 parts of 1,3-butadiene, 5.4 parts of styrene, 0.5 part of hydroxyethyl acrylate, 1 itaconic acid Part, sodium dodecylbenzenesulfonate 0.5 part, t-dodecyl mercaptan 0.5 part, potassium persulfate 1.2 part, cyclohexene 3 part, heated to 60 ° C. with sufficient stirring and reacted for 1 hour, A mixture consisting of 40 parts of 1,3-butadiene and 48.6 parts of styrene was continuously added in 8 hours, and the polymerization reaction was completed by maintaining the mixture at 60 ° C. for 8 hours. Subsequently, 0.5 part of sodium dodecylbenzenesulfonate was added, the pH was adjusted to 6 by adding an aqueous caustic soda solution, and unreacted monomers were removed by steam distillation to obtain a copolymer latex (f). It was. The number average particle diameter of the copolymer latex (f) was 180 nm.

Production of copolymer latex (g) In a 10 liter autoclave, 100 parts of water, 4.5 parts of 1,3-butadiene, 5.5 parts of styrene, 0.3 part of sodium dodecylbenzenesulfonate, 1 part of oxyethylene alkyl ether (Emalgen 120 manufactured by Kao Corporation), 0.5 part of t-dodecyl mercaptan, and 1.2 parts of potassium persulfate were heated to 60 ° C. with sufficient stirring and reacted for 1 hour. , 3-butadiene 40.5 parts and styrene 49.5 parts were continuously added in 8 hours and kept at 60 ° C. for 6 hours to complete the polymerization reaction. Subsequently, 0.5 parts of sodium dodecylbenzenesulfonate and 3 parts of polyoxyethylene alkyl ether (Emalgen 120, manufactured by Kao Corporation) were added, the pH was adjusted to 7 by addition of an aqueous solution of caustic soda, and unreacted simple substance was obtained by steam distillation. The monomer and the like were removed to obtain a copolymer latex (g). The number average particle diameter of the copolymer latex (g) was 190 nm.

Production of copolymer latex (h) To a 10 liter autoclave, 100 parts of water, 4.3 parts of 1,3-butadiene, 5.5 parts of styrene, sodium alkyl sulfate (Taikalite N1230 manufactured by Teika Co., Ltd.) ) 0.4, t-dodecyl mercaptan 0.4 part, potassium persulfate 1.2 part, with sufficient stirring, heated to 60 ° C. and reacted for 1 hour, 1,3-butadiene 38.7 parts, styrene A mixture consisting of 49.5 parts, 1 part of acrylic acid and 1 part of itaconic acid was continuously added in 6 hours, and the polymerization reaction was completed by keeping the mixture at 60 ° C. for 6 hours. Subsequently, the pH was adjusted to 6 by adding an aqueous caustic soda solution, and unreacted monomers and the like were removed by steam distillation to obtain a copolymer latex (h). The number average particle diameter of the copolymer latex (h) was 170 nm.

Production of copolymer latex (i) In a 10 liter autoclave, 100 parts of water, 11.85 parts of 1,3-butadiene, 18 parts of styrene, 0.5 part of acrylic acid, sodium dodecylbenzenesulfonate 0 .25 parts, 0.4 parts of t-dodecyl mercaptan and 0.9 parts of potassium persulfate were heated to 70 ° C. with sufficient stirring and reacted for 6 hours to give 27.65 parts of 1,3-butadiene and 42 of styrene. A mixture consisting of 1.5 parts of polyoxystyrenated phenol and 1.5 parts of sodium polyoxyalkylphenol ether sulfate was continuously added over 10 hours, and the polymerization reaction was completed by maintaining at 70 ° C. for 8 hours. Subsequently, the pH was adjusted to 6 by adding an aqueous caustic soda solution, and unreacted monomers and the like were removed by steam distillation to obtain a copolymer latex (i). The number average particle diameter of the copolymer latex (i) was 230 nm.

Preparation of copolymer latex (j) Into a 10 liter autoclave, 100 parts of water, 12 parts of 1,3-butadiene, 18 parts of styrene, 0.25 part of sodium dodecylbenzenesulfonate, t-dodecyl mercaptan 0 .4 parts, 0.9 part of potassium persulfate with sufficient stirring, heated to 70 ° C. and reacted for 6 hours, 28 parts of 1,3-butadiene, 42 parts of styrene, 0.5 part of polyoxystyrenated phenol Then, a mixture of 1.5 parts of sodium polyoxyalkylphenol ether sulfate was continuously added over 10 hours, and the polymerization reaction was completed by keeping the mixture at 70 ° C. for 8 hours. Subsequently, the pH was adjusted to 6 by adding an aqueous caustic soda solution, and unreacted monomers and the like were removed by steam distillation to obtain a copolymer latex (j). The number average particle diameter of the copolymer latex (j) was 210 nm.

[Examples 1-5, Comparative Examples 1-5]
Formulation of main agent Each copolymer latex obtained above (prepared to a solid content of 45%) / polyvinyl alcohol (Kuraray made Poval 217, prepared to a solid content of 15% aqueous solution) / calcium carbonate (made by Maruo Calcium) Super SS) / sodium hexametaphosphate was blended and stirred so that the apparent parts by weight were 100 parts / 100 parts / 50 parts / 0.5 parts to prepare each main agent.

Blending of adhesives 39 parts of polydiphenylmethane polyisocyanate (Cosmonate M-200 manufactured by Mitsui Takeda Chemical Co., Ltd.) was added as a cross-linking agent to each of the above main ingredients, and stirred vigorously for 5 minutes, as shown in Table 1. Each adhesive of Examples 1-5 and Comparative Examples 1-5 was obtained.

Test method Viscosity was measured using a BH viscometer according to JIS K6833 6.3.
(1) Storage stability The viscosity at normal temperature immediately after blending the main agent (immediately after viscosity) and sealed in a polybin and stored at 40 ° C. for 10 days, after returning to 23 ° C., the viscosity (viscosity with time) was measured.
(2) After completion of blending the pot life adhesive, the viscosity after being allowed to stand at 23 ° C. for 5 minutes and the viscosity after being allowed to stand for 180 minutes were measured.
(3) Normal compression shear bond strength The normal compression shear bond strength was measured according to JIS K 6806 4.11.1 (compression shear bond strength).
(4) Hot water compression shear strength The hot water compression shear strength was measured according to JIS K 6806 4.11.1 (compression shear strength).

It is clear that the aqueous polymer isocyanate-based adhesive using the copolymer latex of the present invention has a significantly improved pot life compared to the conventional ones and is excellent in adhesion performance balance.

Claims (3)

An emulsifier comprising a monovalent cation salt of a polyaromatic compound polysulfonate having two or more aromatic rings in one molecule and at least one of the aromatic rings having an aliphatic hydrocarbon group as a substituent. A copolymer for aqueous polymer isocyanate adhesives obtained by emulsion polymerization of 20 to 60% by weight of an aliphatic conjugated diene monomer and 80 to 40% by weight of another vinyl monomer copolymerizable therewith. Polymer latex. An emulsifier comprising a monovalent cation salt of a polyaromatic compound polysulfonate having two or more aromatic rings in one molecule and at least one of the aromatic rings having an aliphatic hydrocarbon group as a substituent. 20 to 60% by weight of an aliphatic conjugated diene monomer, 10 to 50% by weight of an unsaturated carboxylic acid alkyl ester monomer, and 70 to 0% by weight of another vinyl monomer copolymerizable therewith. % Copolymer latex for aqueous polymer isocyanate adhesives. 5 to 200 parts by weight of a water-soluble polymer and 10 to 250 parts by weight of an isocyanate compound are blended with 100 parts by weight of the copolymer latex (solid content) according to claim 1 or 2. Adhesive.