KR20060101287A - Aqueous emulsion and method of producing the same - Google Patents

Abstract

Modified polyurethane aqueous emulsions comprising emulsion polymerization of monomers containing ethylene, vinyl esters and polyfunctional monomers, and polyurethane aqueous emulsions with redox catalysts using erythorbic acid and / or ascorbic acid and salts of transition metals as reducing agents. Manufacturing method.

Description

Aqueous emulsion and its manufacturing method {AQUEOUS EMULSION AND METHOD OF PRODUCING THE SAME}

The present invention relates to an aqueous emulsion and a method for preparing the same.

As an adhesive composition having excellent adhesion and heat resistant creep under general conditions, an adhesive composition containing ethylene vinyl acetate polyfunctional monomer-based copolymer aqueous emulsion and polyurethane aqueous emulsion is known (Japanese Patent Laid-Open No. 9). -194811) [claims], a suitable adhesive composition for adhesives is described between a wood material and a polyvinyl chloride sheet.

In view of environmental problems, polyvinylchloride sheets are being converted to polyolefin sheets, and, in terms of polyolefin sheets, there is a demand for an adhesive composition having excellent adhesiveness and heat creep resistance under general conditions that are equal to or greater than polyvinylchloride sheets. do.

As an adhesive composition having excellent adhesion and heat creep resistance under general conditions to a polyolefin sheet, an adhesive composition obtained by emulsion-polymerizing ethylene and vinyl acetate with ammonium persulfonate using a polyurethane aqueous emulsion as a seed is disclosed. (Japanese Patent Laid-Open No. 2004-211037, [claim 1], [0035]).

 The inventors made an attempt to prepare an aqueous emulsion obtained by further emulsion polymerizing ethylene and vinyl acetate with ammonium persulfate as a catalyst using a polyurethane aqueous emulsion as a seed according to Example 1 of Japanese Patent Application Laid-Open No. 2004-211037. come.

An object of the present invention is to provide an aqueous emulsion which provides an adhesive having excellent heat creep resistance and a method for producing the same.

The present inventors have diligently studied and found an aqueous emulsion with some problems as described above, and as a result, in a method for producing an aqueous emulsion comprising emulsion polymerizing a polyurethane aqueous emulsion with a monomer of any species under any conditions. Thus, the present inventors have found that an aqueous emulsion can be prepared that provides an adhesive with excellent heat creep resistance, thus completing the present invention.

That is, this invention provides the following [1]-[7].

[1] A reducing agent comprising a step of emulsion polymerizing a monomer containing ethylene, a vinyl ester and a polyfunctional monomer, and a polyurethane aqueous emulsion with a redox catalyst containing a salt of a transition metal, erythorbic acid and / or ascorbic acid. Method for producing a modified polyurethane aqueous emulsion, characterized in that.

[2] The method for producing a modified polyurethane aqueous emulsion according to [1], wherein the redox catalyst contains a hydrogen peroxide as an oxidizing agent.

[3] A modified polyurethane aqueous emulsion, which is obtained by the method described in [1] or [2].

[4] An adhesive comprising the modified polyurethane aqueous emulsion according to [3].

[5] A laminate comprising an adhesive layer made of the adhesive according to [4] and a base material capable of absorbing water.

[6] The laminate according to [5], further comprising laminating a polyolefin layer on the surface of the adhesive layer.

[7] adding a monomer containing ethylene, a vinyl ester and a polyfunctional monomer to the polyurethane aqueous emulsion in the presence of a redox catalyst containing a salt of a transition metal, erythorbic acid and / or ascorbic acid, as a reducing agent, and

A process for producing a modified polyurethane aqueous emulsion, comprising the step of heating at a temperature of about 20 ° C to 80 ° C.

Hereinafter, the present invention will be described in detail.

The polyurethane aqueous emulsion used in the present invention is an aqueous emulsion in which a polyurethane obtained by reacting a polyol compound or another compound with a polyisocyanate compound is dispersed in water. Examples of the reaction method include acetone method, prepolymer mixing method, ketimine method, hot melt dispersion method and the like.

As said polyisocyanate compound, the organic polyisocyanate compound which has 2 or more isocyanate compounds in the molecule | numerator used for normal polyurethane manufacture is mentioned. Specific examples thereof include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 3-isocyanate methyl-3,5,5-trimethyl Cyclohexyl isocyanate, dicyclohexyl methane-4,4'-diisocyanate, methylcyclohexyl-2,4-diisocyanate, methylcyclohexyl-2,6-diisocyanate, xylylenediisocyanate (XDI), 1,3 Aliphatic diisocyanates such as bis (isocyanate) methylcyclohexane, tetramethylxylylene diisocyanate, transcyclohexane-1,4-diisocyanate and lysine diisocyanate; 2,4-toluylene diisocyanate (TDI), 2,6-toluylene diisocyanate (TDI), diphenylmethane-4,4'- diisocyanate (MDI), 1,5'-naphthene diisocyanate, tolidinedi Aromatic diisocyanates such as isocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyldiisocyanate and 1,3-phenylenedi isocyanate; Lysine ester triisocyanate, triphenylmethane triisocyanate, 1,6,11- undecane triisocyanate, 1,8-isocyanate-4,4-isocyanate methyl octane, 1,3,6-hexamethylene triisocyanate, bicycloheptane Triisocyanates such as triisocyanates, addition products of trimethylolpropane and toluylene diisocyanate, addition products of trimethylolpropane and 1,6-hexamethylene diisocyanate, and the like, and these may be used alone or in combination of two or more thereof. good.

As said polyol compound, the compound which has two or more hydroxyl groups in the molecule | numerator used for normal polyurethane production is mentioned, The specific example is ethylene glycol, diethylene glycol, propylene glycol, 1, 4- butanediol, Polyhydric alcohols such as 1,6-hexanediol, neopentylglycol, trimethylolpropane and glycerin; Polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene ether glycol; Dicarboxylic acid and ethylene such as adipic acid, sebacic acid, itaconic acid, maleic anhydride, terephthalic acid, isophthalic acid, fumaric acid, succinic acid, oxalic acid, maronic acid, glutaric acid, pimeric acid, subberic acid, azelaic acid and the like Glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentylglycol, 1,2-propanediol, 1,3-propanediol, 1,9-nonanediol, 3-methyl Polyester polyols obtained from polyol compounds such as -1,5-pentanediol, 1,3-propanediol, tripropylene glycol, trimethylol propane and glycerin; Polylactone polyester polyols such as polycaprolactone polyol and poly β-methyl-d-valerolactone; Polybutadiene polyol or its hydride, polycarbonate polyol, polythioether polyol, polyacrylate polyol and the like.

In preparing a polyurethane aqueous emulsion, it is preferable to introduce a hydrophilic group into the molecule since the stability can be enhanced when the polyurethane aqueous emulsion is dispersed in water. As compounds used for introduction of a hydrophilic group, for example, has a nonionic hydrophilic group, such as a structural unit derived from a polyethylene glycol molecule, a sulfonyl group, a carboxyl group, a hydroxyl group, primary amino group (-NH _{2), 2} primary amino group ( And compounds having one or more active hydrogens having reactivity with isocyanate groups such as = NH) (hereinafter sometimes referred to as hydrophilic group-containing compounds).

Examples of the hydrophilic group-containing compound include 3,4-diaminobutanesulfonic acid, 3,6-diamino-2-toluenesulfonic acid, 2,6-diaminobenzenesulfonic acid and N- (2-aminoethyl) -2-amino Sulfonic acid-containing compounds such as ethyl sulfonic acid; Carboxylic acid containing compounds, such as 2, 2- dimethyl olactic acid, 2, 2- dimethylol propionic acid, and 2, 2- dimethylol valeric acid, are contained. The said hydrophilic group containing compound may be used individually or in combination of 2 or more types.

The polyurethane aqueous emulsion containing a hydrophilic group obtained by using the hydrophilic group-containing compound in a molecule is called an ionomer structure, and itself has a surface active ability. Therefore, it is easily disperse | distributed in water, and also shows the preferable tendency which improves the water resistance of the aqueous emulsion obtained by emulsion polymerization of a monomer and a polyurethane aqueous emulsion.

As said hydrophilic group, anionic groups, such as a sulfonyl group and a carboxyl group, are preferable, and a sulfonyl group is especially preferable since it has the tendency to further increase the water resistance of the aqueous emulsion obtained by emulsion polymerization of a monomer.

It is preferable that the anionic group is generally neutralized with a neutralizing agent. The neutralizing agent may be a tertiary amine compound such as triethylamine and triethanolamine; Nonionic alkali compounds such as sodium hydroxide; Ammonia and the like.

In preparing a polyurethane aqueous emulsion, a compound containing active hydrogen capable of reacting with an isocyanate compound in the molecule may be used, and if necessary, a compound different from the hydrophilic group-containing compound may be used for chain extension and molecular weight control. Examples of such a compound include polyvalent amine compounds such as ethylenediamine, 1,4-butanediamine, and 1,6-hexanediamine; Polyhydric alcohols containing tertiary amines such as triethanolamine, monoalcohols such as methanol, ethanol, butanol and the like.

As the polyurethane aqueous emulsion, a commercially available polyurethane aqueous emulsion may be used.

Specifically, U of HYDRAN ECOS-3000, ADS-120, ADS-110, Sanyo chemical industries, Ltd., UPRENE UXA-3005, Sumika Bayer Urethane Co., Ltd., manufactured by Dainippon Ink & Chemicals, Inc. -53, U-54, U-56 and the like.

The method for producing a modified polyurethane aqueous emulsion of the present invention is a method for emulsion polymerization using a polyurethane aqueous emulsion as a seed and ethylene, a vinyl ester and a polyfunctional monomer as monomers. Hereinafter, the method is referred to as seed polymerization method.

Examples of vinyl esters used in the seed polymerization method include vinyl acetate, vinyl butyrate, vinyl propionate, vinyl pivalate, vinyl laurate, vinyl isononanoate, vinyl versatate, and the like. As said vinyl ester, 2 or more types of vinyl esters may be used. Among the vinyl esters, vinyl acetate is preferably used.

The use amount of the said vinyl ester is about 60-95 weight part with respect to 100 weight part of total amounts used for the said seed polymerization method.

The polyfunctional monomer means a monomer capable of supplying two or more ethylene double bonds to monomers such as ethylene and vinyl ester. Specific examples of the polyfunctional monomer include triallyl cyanurate, triallyl isocyanurate, diallyl phthalate and the like.

The amount of the polyfunctional monomer to be used is preferably about 0.01 to 1 parts by weight, preferably about 0.05 to 0.5 parts by weight based on 100 parts by weight of the vinyl ester used in the seed polymerization method, and in the above range, the heat creep resistance is improved. Do.

The monomer used in the seed polymerization method is a monomer different from ethylene, vinyl ester and a polyfunctional monomer, and a monomer capable of supplying one ethylene double bond (hereinafter sometimes referred to as a copolymerizable monomer) may be used. Specific examples thereof include vinyl halides such as vinyl chloride and vinyl bromide; Vinylidene halides such as vinylidene chloride; Vinyl compounds such as vinylphosphonic acid, vinylsulfonic acid and salts thereof; Aromatic vinyls such as styrene, α-methylstyrene, and chlorostyrene; (Meth) acrylic acid, such as methacrylic acid and acrylic acid; (Meth) acrylates, such as methyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate; Α, β-unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, succinic acid and itaconic acid; Nitriles such as (meth) acrylonitrile; Acrylamides such as N-methylol acrylamide and N-butoxymethyl acrylamide; Allyl compounds, such as an allyl sulfonate, etc. are contained.

As for the usage-amount of the said copolymerizable monomer, 20 weight part or less is common with respect to 100 weight part of total amounts of the monomer used for a seed polymerization method, and 10 weight part or less is preferable.

In the present invention, the redox catalyst is used in the seed polymerization method,

The redox catalyst refers to a catalyst system that generates radicals by the reaction of an oxidizing agent and a reducing agent. The redox catalyst may generate radicals even at a low temperature of about 25 ° C.

The reaction is initiated by heat generation caused by mixing the oxidizing agent and the reducing agent at once or in portions. The addition method to the polymerization system is a method of adding oxidizing agent and reducing agent in one portion at the same time or by dividing at the same time, the method of adding one of the oxidizing agent and reducing agent in advance to the polymerization system, and adding the other one at once or in portions by dropping or the like. This includes.

As the reducing agent for the redox catalyst, erythorbic acid and / or ascorbic acid are used together with the salt of the transition metal.

Examples of the salt of the transition metal include chlorides such as iron, copper, cobalt, titanium, nickel, chromium, zinc, manganese, vanadium, molybdenum, cerium, sulfates, and the like. Among these, ferroc chloride, ferros sulfate, copper sulfate, etc. are used preferably.

As the reducing agent, the salt of the transition metal is generally about 0.001 to 0.05 wt. Times based on erythorbic acid and / or ascorbic acid. It is preferable in order to improve the reaction rate of emulsion polymerization, since it is 0.001 weight% or more, and it is preferable in it being 0.05 weight% or less, since the coloring of the above-mentioned aqueous emulsion is reduced.

As the reducing agent, examples of the erythorbic acid and / or ascorbic acid include erythorbic acid and ascorbic acid, and alkali metal salts such as sodium salts and potassium salts. Among these, sodium salts are preferable, and sodium erythorbate is particularly preferably used.

The reducing agent is generally used in an amount of 0.02 to 1 part by weight based on 100 parts by weight of vinyl ester. If it is 0.02 weight part or more, since the reaction rate of emulsion polymerization improves, it is preferable, and if it is 1 weight part or less, the discoloration of the produced aqueous emulsion is suppressed and the strength of the obtained aqueous emulsion, for example, the film which consists of aqueous emulsion, is intensity | strength. It is preferable because it improves water resistance and the like.

Examples of the oxidizing agent for the redox catalyst include persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate; peroxides, such as t-butyl peroxide and hydrogen peroxide. Among these, hydrogen peroxide is preferable because it is easy to handle and suppresses discoloration of the obtained aqueous emulsion.

An example (seed polymerization method) of the manufacturing method of a modified polyurethane aqueous emulsion is shown below.

Polyurethane aqueous emulsions, emulsion dispersants, all or part of vinyl esters, salts of transition metals, and all or part of copolymerizable monomers, all or part of polyfunctional monomers, and neutralizing agents such as acetic acid, etc. After being filled and purged with nitrogen, after the temperature is generally increased to about 20-80 ° C., preferably about 40-70 ° C., the partial pressure of ethylene is generally about 1-10 MPa, preferably about Ethylene is pressurized to be 3 to 8 MPa.

Hereinafter, an oxidizing agent such as hydrogen peroxide and erythorbic acid and / or ascorbic acid are gradually mixed in the pressure vessel at about 20 to 80 ° C. The oxidant and erythorbic acid and / or ascorbic acid may be diluted with water or the like to facilitate preparation.

At the same time, while maintaining the temperature, the mixture is thermally added until the remaining vinyl ester, copolymerizable monomer and polyfunctional monomer are gradually added to the pressure resistant container and the vinyl ester in the reaction liquid of the pressure resistant container is sufficiently reduced. Insulated and stirred.

When the vinyl ester is not sufficiently reduced, a redox catalyst such as an oxidizing agent may be added.

In general, the amount of the polyurethane aqueous emulsion used in the seed polymerization method (nonvolatile content) is about 3 to 50 parts by weight based on 100 parts by weight of the nonvolatile content of the aqueous emulsion produced by seed polymerization. If it is 3 weight part or more, since adhesive force improves, it is preferable, and if it is 50 weight part or less, since emulsion polymerization rates, such as ethylene and a vinyl ester, improve, it is preferable.

In the seed polymerization method, an emulsifier may be used.

Examples of the emulsifier include some or all saponified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, starch, modified starch, starch oxide, sodium alginate and the like, and a colloid, polyoxyethylene alkyl ether, poly Nonionic surfactants such as oxyethylene alkyl phenol ether, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, alkyl sulfate, alkylbenzene sulfonate, alkyl sulfosuccinate Anionic surfactants, such as a nitrate, an alkyl diphenyl ether disulfonate, a polyoxyethylene alkyl sulfate, and a polyoxyethylene alkyl phosphate, are included.

Here, the polyvinyl alcohol may be modified with a compound containing carboxylic acid, sulfonic acid, siloxane and the like.

In particular, the polyvinyl alcohol preferably has an average degree of polymerization of about 100 to 3000 and an average degree of saponification of about 80 to 98 mol%.

Regarding the amount of the emulsifying dispersant used, the nonvolatile content of the emulsifying dispersant is generally about 3 to 12 parts by weight, and preferably about 4 to 8 parts by weight based on 100 parts by weight of the total amount of the monomers used in the seed polymerization method.

The content of the structural unit derived from ethylene of the prepared aqueous emulsion is generally about 5 to 70 parts by weight based on 100 parts by weight of the total amount of monomers used in the seed polymerization method. In particular, when the structural unit derived from ethylene is contained in the quantity of 5-35 weight part, since adhesive force improves even at low temperature of about 0-10 degreeC, it is preferable.

When the ethylene partial pressure in the seed polymerization method is 1 MPa or more, the content of the structural unit derived from ethylene of the aqueous emulsion prepared may be improved, and the reaction time may be reduced. On the other hand, it is preferable that partial pressure is 10 Mpa or less from a viewpoint of the pressure tolerance of a pressure-resistant container.

In order to raise the ratio of the structural unit derived from ethylene with respect to the total amount of the structure derived from all the monomers used for the said seed polymerization method, superposition | polymerization is performed, keeping the vinyl ester content of the monomer in the reaction liquid of the said pressure-resistant container low. Preferably, the amount of vinyl ester added initially or after that may be controlled suitably.

The modified polyurethane aqueous emulsion produced generally has a nonvolatile content of about 40-75% by weight, and the emulsion can be diluted with water as needed.

The aqueous emulsion can be used by itself, and also adjusts its water content, and if necessary, the following compounding agent is added, and the resulting mixture is used as an adhesive such as adhesive for wood, adhesive for paper processing, adhesive for plastic, etc. It can be used or it can be used as a paint by coating on the surface of the base material.

As a compounding agent which can be blended with the adhesive, for example, thermosetting resins such as urea resins, melamine resins, phenol resins, fillers such as clay, kaolin, talc, calcium carbonate, preservatives, rust preventive agents, antifoaming agents, foaming agents, polyacrylic acid, poly Thickeners such as ethers, viscosity modifiers, flame retardants, pigments such as titanium oxide, and plasticizers such as dibasic acid esters.

It is recommended to use a filler in order to improve coating force and flame retardancy at the time of adhesion, and the amount of use thereof is generally about 1 to 500 parts by weight, and preferably 5 to 200 parts by weight based on 100 parts by weight of the non-volatile content of the aqueous emulsion. Do.

When the aqueous emulsion is used as an adhesive, it may be used as an active ingredient, as a pot type adhesive containing an aqueous emulsion, and when an adhesive force such as heat creep resistance and water resistance is required, a curing agent is used together. It is desirable to.

As the curing agent, isocyanate-based curing agents are effective, for example, the MDI, TDI, HDI, XDI and oligomers and polymers thereof are listed. As for the compounding quantity of the said hardening | curing agent, 0.1-20 weight part is common with respect to 100 weight part of aqueous emulsion, and 1-10 weight part is preferable. As a commercial item, Sumidur 44V20 by the Sumika Bayer Urethane Co., Ltd., Sumidur N3300, etc. are mentioned, for example.

As a base material adhere | attached to the adhesive agent of this invention, For example, wood-based materials, such as a wood, a plywood, a MDF (medium density fiber board), a particle board, a fiber board; Paper-based materials such as wallpaper and wrapping paper; Cellulosic materials such as cotton fabric, hemp fabric and rayon; Materials which absorb water such as porous materials; The materials which can remove water, such as a nonwoven fabric, are mentioned.

When a part of the adhesive of the present invention is adhered to a material capable of removing water, the other part may be a polyolefin such as polyethylene, polypropylene, polystyrene, plasticizer such as polyester, polyether, polyvinyl chloride or glass, pottery or the like. It may be adhered to a ceramic material.

In particular, the laminate obtained by laminating a polyolefin and water absorbing material with the adhesive of the present invention is almost equivalent to the laminating agent obtained with an adhesive composition comprising an ethylene-vinylacetate copolymer aqueous emulsion and a polyurethane aqueous emulsion under general conditions. It has one or more of adhesiveness and is very excellent in heat creep resistance.

According to the present invention, under general conditions, the ethylene-vinylacetate copolymer emulsion and the polyurethane aqueous emulsion are separately prepared and have almost the same or more adhesive properties as the adhesive obtained by mixing them, and also have excellent heat resistance. Aqueous emulsions with creep properties can be prepared.

In addition, according to the present invention, an aqueous emulsion having excellent heat creep resistance can be easily produced with high reproducibility.

(Example)

The invention is explained in more detail by the following examples, which should not be construed as limiting the invention thereto.

In particular, parts and percentages are per weight unless stated. The nonvolatile content was measured by the method according to JIS K-6828. The viscosity was measured with a Brookfield viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25 ° C.

Example 1

<Production Example of Aqueous Emulsion (B1)>

160 parts vinyl acetate, 7 parts polyvinyl alcohol "PVA-217" (manufactured by Kuraray Corp., degree of saponification: 88 mol%, average degree of polymerization: 1700), two parts "PVA-205" (manufactured by Kuraray Corp., degree of saponification: 88 mol%, average degree of polymerization: 500), 40 parts polyurethane aqueous emulsion (A1, anionic urethane emulsion "HYDRAN ECOS-3000" manufactured by Dainippon Ink & Chemicals, Inc., non-volatile content: 40%), 0.005 parts The solution prepared by dissolving los sulfate heptahydrate and 0.4 part of acetic acid in 150 parts of water in advance was injected into the pressure-resistant container. Then, after the atmosphere in the pressure vessel was purged with nitrogen, the atmosphere in the vessel was heated to 60 ° C. and then pressurized with ethylene to 4.6 MP. Next, 0.5 parts of 30% hydrogen peroxide-containing aqueous solution and 0.6 parts of sodium erythorbate were diluted with water, and their dropping was started. Then, after the increase in the liquid temperature in the pressure vessel was confirmed, a solution prepared by dissolving 0.17 parts of triallyl isocyanurate in 10 parts of vinyl acetate was added over 3 hours. The temperature in the reaction vessel was maintained at 60 ° C. by controlling the temperature of the jacket during polymerization, and an aqueous solution of hydrogen peroxide was added, and the concentration of vinyl acetate in the reaction solution became 1% or less. After the mixture was stirred until, unreacted ethylene gas was removed to give an aqueous emulsion (B1).

The resin composition of the aqueous emulsion (B1) obtained is a structural unit derived from 22 parts of ethylene, a structural unit derived from 0.1 part of triallyl isocyanurate, and 9 parts of polyurethane based on a structural unit derived from 100 parts of vinyl acetate. Resin components (nonvolatile components) derived from the aqueous emulsion (A) and resin components (nonvolatile components) derived from 5.3 parts of polyvinyl alcohol were included. The aqueous emulsion (B1) had 52.5% of nonvolatile components and a viscosity of 1,200 mPa · s.

<Production Example of Adhesive and Laminate>

In 110 parts of aqueous emulsion (B1), as a plasticizer, 5.3 parts of DBE (mixture of dibasic esters (dimethylsuccinate, dimethyladipate, dimethylglutarate)) produced by INVISTA JAPAN and a thickener (SN thickener A-812 , 6 parts of the material obtained by diluting the trademark, SAN NOPCO LIMITED, urethane-modified polyether, active ingredient: 40%) were blended, and the product was used as an adhesive. The adhesion test was done as follows using the said adhesive agent.

<Evaluation of adhesive force>

An aqueous emulsion was applied at 110 g / m ² on a JAS 1 water-resistant plywood, and then a non-vinyl choloride sheet WS-201E manufactured by Dai Nippon Printing Co., Ltd. was laminated and After degassing, it was allowed to stand for one day while compressing to 50 kgf / 900 cm ² , and after further decompressing, it was further dried for 6 days to obtain a laminate.

Peel strength under general conditions was measured at a peel rate of 200 mm / min by Autograph (manufactured by Autograph, manufactured by Shimadzu). For heat creep resistance, the laminate was adjusted to 80 ° C., and then peeled off at a peel angle of 90 ° and a load of 500 gf / 25 mm, and the peeled length at each time was measured. The results are summarized in Table 1.

Example 2

<Production Example of Aqueous Emulsion (B2)>

Instead of the polyurethane aqueous emulsion of Example 1 (A1, 40 parts of HYDRAN ECOS-3000 manufactured by Dainippon Ink & Chemicals, Inc.), 32 parts of polyurethane aqueous emulsion (A2, manufactured by Dainippon Ink & Chemicals, Inc., ADS-120 (50%)) was used in the same procedure as in Example 1 except that it was used.

The resin composition of the obtained aqueous emulsion (B2) is a structural unit derived from 22 parts of ethylene, a structural unit derived from 0.1 part of triallyl isocyanurate, and 9 parts of polyurethane based on a structural unit derived from 100 parts of vinyl acetate. The resin component (nonvolatile component) derived from aqueous emulsion (A) and the resin component (nonvolatile component) derived from 5.3 parts of polyvinyl alcohol are included. The aqueous emulsion (B2) had 53.1% of nonvolatile components and a viscosity of 7570 mPa · s.

Into 110 parts of the aqueous emulsion (B2) was mixed DBE made from 5.3 parts of INVISTA JAPAN, and the material obtained by diluting 0.5 parts of SAN NOPCO LIMITED thickener A-812 twice was mixed, and then the product was prepared as an adhesive. Was used and the adhesion experiment described in Example 1 was conducted.

Comparative Example 1

<Production example of aqueous emulsion (C)>

The same procedure was followed as in Example 1, except that 0.5 parts of sodium persulfate were used instead of 0.5 parts of 30% hydrogen peroxide-containing aqueous solution and 0.6 parts of sodium erythorbate.

The vinyl acetate in the pressure vessel did not decrease and the emulsion polymerization did not proceed.

Comparative Example 2

<Production Example of Ethylene Vinyl Acetate Polyfunctional Monomer Copolymer Aqueous Emulsion (D)>

180 parts vinyl acetate, 8 parts polyvinyl alcohol "PVA-217" (manufactured by Kuraray Corp., degree of saponification: 88 mol%, average degree of polymerization: 1700), 2.3 parts "PVA-205" (manufactured by Kuraray Corp., saponification degree: 88 mol%, average degree of polymerization: 500), 0.005 parts of ferros sulfate heptahydrate and 0.4 parts of acetic acid were pre-dissolved in 160 parts of water, and the solution prepared was injected into a pressure-resistant container. Thereafter, the atmosphere in the pressure vessel was purged with nitrogen gas, and the atmosphere in the vessel was heated to 60 ° C, and then pressurized with ethylene to 4.6 MPa. Then 0.33 parts of an aqueous solution containing 30% hydrogen peroxide and 0.6 parts of sodium erythorbate were diluted with water and their dropping started. Then, after the increase in the liquid temperature in the pressure vessel was confirmed, a solution prepared by dissolving 0.19 parts of triallyl isocyanurate in 10 parts of vinyl acetate was added over 3 hours. By controlling the temperature of the jacket during the polymerization, the temperature in the reaction vessel was maintained at 60 ° C., and an aqueous solution of hydrogen peroxide was added until the concentration of vinyl acetate in the reaction solution became 1% or less. After stirring the mixture, unreacted ethylene gas was removed to obtain an ethylene vinyl acetate polyfunctional monomer-based copolymer aqueous emulsion (D).

The resin composition of the aqueous emulsion (D) obtained is a structural unit derived from 22 parts of ethylene, a structural unit derived from 0.1 part of triallyl isocyanurate and 5.4 parts of polyvinyl alcohol with respect to a structural unit derived from 100 parts of vinyl acetate. It includes the resin component derived from. The aqueous emulsion (D) had a nonvolatile content of 55.0% and a viscosity of 3000 mPa · s.

<Production Example of Adhesive and Laminate>

100 parts of aqueous emulsion (D) were formulated with 4.8 parts of DBE manufactured by INVISTA JAPAN, and 4 parts of the material obtained by diluting the thickener A-812 manufactured by SAN NOPCO LIMITED was compounded, and then the product was used as an adhesive. Using the said adhesive agent, the adhesion experiment as described in Example 1 was done. The results are summarized in Table 1.

Comparative Example 3

<Production Example of Adhesive Composition Composed of Aqueous Emulsion (D) and Polyurethane Aqueous Emulsion>

100 parts of aqueous emulsion (D) obtained in Comparative Example 2, 10.6 parts of anionic urethane emulsion "HYDRAN ECOS-3000" (non-volatile content of 40% by Dainippon Ink & Chemicals, Inc.) and 5.3 parts of DBE manufactured by INVISTA JAPAN The pH was adjusted to 8-9 with 0.2 parts of 25% ammonia, and then 4 parts of the material obtained by diluting the thickener A-812 manufactured by SAN NOPCO LIMITED twice was combined to obtain an adhesive. Using this adhesive, the same adhesion experiment as in Example 1 was conducted. The results are summarized in Table 1.

Comparative Example 4

<Production Example of Adhesive Composition Composed of Ethylene Vinyl Acetate Polyfunctional Monomer Copolymer Aqueous Emulsion (D) and Polyurethane Aqueous Emulsion>

100 parts aqueous emulsion (D) obtained in Comparative Example 2, 8.5 parts anionic urethane emulsion "HYDRAN ADS-120" (manufactured by Dainippon Ink & Chemicals, Inc., non-volatile content: 50%) and 5.3 parts DBE manufactured by INVISTAR JAPAN The pH was adjusted to 8-9 with 0.2 parts of 25% ammonia, and then 4 parts of the material obtained by diluting the thickener A-812 manufactured by SAN NOPCO LIMITED twice was combined to obtain an adhesive. The same adhesion experiment as in Example 1 was conducted using this adhesive. The results are summarized in Table 1.

Comparative Example 5

<Production example of aqueous emulsion (E)>

170 parts vinyl acetate, 2 parts polyvinyl alcohol "PVA-217" (manufactured by Kuraray Corp., saponification degree: 88 mol%, average degree of polymerization: 1700), 6 parts "PVA-205" (manufactured by Kuraray Corp., saponification degree: 88 mol%, average degree of polymerization: 500), 40 parts of polyurethane aqueous emulsion (A) (polyester-based anionic urethane emulsion "HYDRAN ECOS-3000" manufactured by Dainippon Ink & Chemicals, Inc., non-volatile content: 40%) And a solution prepared by dissolving 0.005 parts of ferros sulfate heptahydrate and 0.4 parts of acetic acid in 150 parts of water in advance were injected into a pressure resistant vessel. Subsequently, the atmosphere in the pressure vessel was purged with nitrogen gas, and the atmosphere in the vessel was heated to 60 ° C., and then pressurized with ethylene to 4.6 MPa. Then 0.5 parts of 30% hydrogen peroxide aqueous solution and 0.6 parts of sodium erythorbate were diluted with water and their dropping was initiated. By controlling the temperature of the jacket during the polymerization, the temperature of the reaction vessel was maintained at 60 ° C., and an aqueous solution of hydrogen peroxide was further added, and then the concentration of vinyl acetate in the reaction solution became 1% or less. After stirring the mixture until unreacted ethylene gas was removed to give an aqueous emulsion (E).

The resin composition of the obtained aqueous emulsion (E) comprises a structural unit derived from 22 parts of ethylene, 9 parts of a resin component (nonvolatile content) and 4.7 parts of a structural unit derived from 100 parts of vinyl acetate. The resin component (nonvolatile content) of negative polyvinyl alcohol was included.

The aqueous emulsion (E) had a nonvolatile content of 52.9% and a viscosity of 1890 mPa · s.

In 110 parts of the emulsion (E), 6 parts of the material obtained by diluting 5.3 parts of DBE manufactured by INVISTA JAPAN and thickener A-812 manufactured by SAN NOPCO LIMITED were combined to obtain an adhesive, and Example 1 was used. The same adhesion experiment was carried out. The results are summarized in Table 1.

Comparative Example 6

<Preparation Example of Ethylene Vinyl Acetate Copolymer Aqueous Emulsion (F)>

190 parts vinyl acetate, 2.3 parts polyvinyl alcohol "PVA-217" (manufactured by Kuraray Corp., degree of saponification: 88 mol%, average degree of polymerization: 1700), 7 parts "PVA-205" (manufactured by Kuraray Corp., degree of saponification: 88 mol%, average degree of polymerization: 500), 0.005 parts of ferros sulfate heptahydrate and 0.4 parts of acetic acid were pre-dissolved in 160 parts of water, and the prepared solution was injected into a pressure-resistant container. Subsequently, the atmosphere in the pressure vessel was purged with nitrogen gas, and the atmosphere in the vessel was heated to 60 ° C., and then pressurized with ethylene to 4.6 MPa. Subsequently, 0.33 parts of an aqueous solution containing 30% hydrogen peroxide and 0.6 parts of sodium erythorbate were diluted with water and their dropping was initiated. By controlling the temperature of the jacket during the polymerization, the temperature of the reaction vessel was maintained at 60 ° C., an aqueous solution of hydrogen peroxide was further added, and then the concentration of vinyl acetate in the reaction solution was 1% or less. After the mixture was stirred until unreacted ethylene gas was removed to give an ethylene vinyl acetate copolymer aqueous emulsion (F).

The resin composition of the obtained aqueous emulsion (F) contained a structural unit derived from 22 parts of ethylene and a resin component (nonvolatile content) of 4.9 parts of polyvinyl alcohol with respect to the structural unit derived from 100 parts of vinyl acetate. The aqueous emulsion (F) had a nonvolatile content of 55.0% and a viscosity of 1200 mPa · s.

<Production example of adhesive composition consisting of an aqueous emulsion (F) and a polyurethane aqueous emulsion>

100 parts aqueous emulsion (F), 10.6 parts anionic urethane emulsion "HYDRAN ECOS-3000" (manufactured by Dainippon Ink & Chemicals, Inc., non-volatile content: 40%) and 5.3 parts DBE manufactured by INVISTAR JAPAN were combined. The pH was adjusted to 8-9 with 0.2 parts of 25% ammonia, and then 6 parts of the material obtained by diluting the thickener A-812 manufactured by SAN NOPCO LIMITED twice was combined to obtain an adhesive. The same adhesion experiment as in Example 1 was conducted using this adhesive. The results are summarized in Table 1.

ECOS-3000: HYDRAN ECOS-3000 manufactured by Dainippon Ink & Chemicals, Inc.

ADS-120: HYDRAN ADS-120 manufactured by Dainippon Ink & Chemicals, Inc.

DBE: DBE by INVISTA JAPAN

2-fold diluted A-812: obtained by 2-fold dilution of A-812 from SAN NOPCO LIMITED

As apparent from Table 1, reproduction of Japanese Patent Laid-Open No. 2004-211037 was difficult (Comparative Example 1), but the production methods (Examples 1 and 2) of the present invention were easily performed. The adhesive of the present invention is an adhesive containing only an ethylene vinyl acetate polyfunctional monomer copolymer-containing aqueous emulsion as an active ingredient (comparative example 2) under general conditions, and an adhesive containing the copolymer-containing aqueous emulsion and polyurethane aqueous emulsion (Japan It had almost the same strength as Patent Publication No. Hei 9-194811, Comparative Examples 3, 4 and 6). However, the heat resistance creep resistance of the adhesive of the present invention was very excellent even for a long time.

Moreover, when a polyfunctional monomer is not used for seed polymerization (comparative example 5), heat creep resistance becomes very low.

The modified polyurethane aqueous emulsion produced by the method of the present invention is used for woodworking, paper processing, wallpaper, packaging, (secondary) plywood, construction, factory, lamination, textile, household, civil construction, bookbinding. One pot adhesive such as a solvent; Two potted adhesives used with curing agents; It can be used suitably for paints and the like.

Claims (7)

A reducing agent comprising the step of emulsion polymerizing a monomer containing ethylene, a vinyl ester and a polyfunctional monomer and a polyurethane aqueous emulsion with a redox catalyst containing a salt of a transition metal, erythorbic acid and / or ascorbic acid. Method of producing a modified polyurethane aqueous emulsion. The method for producing a modified polyurethane aqueous emulsion according to claim 1, wherein the redox catalyst contains hydrogen peroxide as an oxidizing agent. It is obtained by the method of Claim 1 or 2, The modified polyurethane aqueous emulsion characterized by the above-mentioned. An adhesive comprising the modified polyurethane aqueous emulsion according to claim 3. A laminated body comprising an adhesive layer made of the adhesive according to claim 4 and a substrate capable of absorbing water. The laminate according to claim 5, wherein the polyolefin layer is further laminated on the surface of the adhesive layer. Adding as a reducing agent a monomer containing ethylene, a vinyl ester and a polyfunctional monomer in a polyurethane aqueous emulsion in the presence of a redox catalyst containing a salt of a transition metal, erythorbic acid and / or ascorbic acid, and A process for producing a modified polyurethane aqueous emulsion, comprising the step of heating at a temperature of about 20 ° C to 80 ° C.