JP2005200440A - Tackifier resin emulsion and adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tackifier resin emulsion imparting better initial adhesiveness as compared with a conventional aqueous adhesive and having good stability even when produced without using an organic solvent and to provide an aqueous adhesive having the good initial adhesiveness. <P>SOLUTION: The tackifier resin emulsion is obtained by emulsifying a tackifier resin in the presence of a polymeric emulsifying agent composed of an anionic monomer (A) and an alkyl (meth)acrylate (B) as main constituents and having ≤110°C glass transition point. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tackifier resin emulsion and an adhesive composition containing the tackifier resin emulsion.

  Adhesives are used in a wide range of fields such as packaging, construction, and building materials. Generally, a tackifier resin is added to a base polymer such as an acrylic polymer to impart tack properties such as tack. ing. In the past, solvent-based adhesives have been widely used. However, in recent years, water-based emulsion adhesives have various advantages such as no air pollution, excellent health and safety, and resource saving. It is being converted.

  Conventionally, as a water-based adhesive, an acrylic polymer emulsion, a styrene-butadiene copolymer latex, a natural rubber latex, a chloroprene latex, etc. are used as a base polymer, and rosins, rosin derivatives, petroleum resins, terpene resins, A water-based adhesive composition obtained by blending a tackifier resin emulsion such as a phenol resin or a ketone resin is known. Usually, such tackifier resin emulsions are widely used as emulsions of rosin resins such as rosins and rosin derivatives because they have good compatibility with base polymers and good adhesive properties.

  However, even when these rosin-based resin emulsions are used, the initial adhesiveness and coating properties particularly required for aqueous adhesives are insufficient, and aqueous adhesives that can improve these are required.

  By the way, the present applicant was excellent in mechanical stability and heat resistance using a reactive emulsifier, a polymer emulsifier mainly composed of styrene and / or (meth) acrylic acid alkyl ester and an anionic monomer. A tackifier resin emulsion has been proposed (see Patent Document 1). However, the resin emulsion does not necessarily satisfy initial adhesiveness, and if an attempt is made to produce a resin emulsion that does not contain a solvent, stability and the like There were cases where there was a problem. In addition, the present applicant has proposed a tackifier resin emulsion having improved initial adhesiveness (see Patent Document 2), but the tackifier resin emulsion has a specific acid value and a softening point. There was a problem that it was applicable only to resin.

JP 7-331208 A JP 2003-336021 A

An object of the present invention is to provide a tackifier resin emulsion that gives good initial adhesiveness as compared with conventional aqueous adhesives and has good stability even when produced without using an organic solvent. To do.

  As a result of investigations to solve the above problems, the present inventors have found that the above problems can be solved by using a polymer emulsifier having a specific glass transition point. It has been found that the initial adhesiveness can be particularly improved by using a polymer of the component.

That is, the present invention comprises an anionic monomer (A) and a (meth) acrylic acid alkyl ester (B) as main components, and in the presence of a polymer emulsifier having a glass transition point of 110 ° C. or lower. The present invention relates to a tackifier resin emulsion obtained by emulsifying a tackifier resin and an adhesive composition comprising the tackifier resin emulsion.

  According to the present invention, not only gives good initial adhesiveness compared to conventional aqueous adhesives, but also storage stability is good when a tackifier resin emulsion is produced without using an organic solvent. A tackifier resin can be provided. Therefore, since the tackifier resin emulsion produced without using the organic solvent does not contain an organic solvent, it is preferable in terms of safety and health. In addition, the water-based adhesive composition using the tackifier resin emulsion is excellent in initial adhesiveness, and the tackifier resin emulsion produced without using an organic solvent does not contain a solvent. Is also preferable.

  The tackifier resin emulsion of the present invention comprises an anionic monomer (A) (hereinafter referred to as component (A)) and (meth) acrylic acid alkyl ester (note that (meth) acrylic acid alkyl ester is alkyl acrylate). An ester and / or a methacrylic acid alkyl ester. Hereinafter, (meth) has the same meaning.) (B) (hereinafter referred to as component (B)) as a main component has a glass transition point of 110 ° C. or lower. It is obtained by emulsifying the tackifier resin in the presence of the polymer emulsifier.

Component (A), which is a component of the polymer emulsifier of the present invention, includes monocarboxylic acids such as (meth) acrylic acid and crotonic acid, and dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, and muconic acid. Carboxylic acids such as vinyl sulfonic acid, styrene sulfonic acid, organic sulfonic acids such as 2-acrylamido-2-methylpropane sulfonic acid, etc .; phosphate vinyl monomers such as 2- (meth) acryloyloxyethyl acid phosphate; and these Examples thereof include alkali metal salts such as sodium salts and potassium salts of various organic acids, alkaline earth metal salts, ammonium salts, and salts of organic bases. Among these (A) components, (meth) acrylic acid is preferred because of its high copolymerizability and good emulsifying properties. In addition, (A) component may be used individually, respectively and may use 2 or more types together.

The component (B), which is a constituent component of the polymer emulsifier used in the present invention, is not particularly limited, and known ones can be used. Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth) acrylic Examples include iso-butyl acid, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, and the like. Of these, (meth) acrylic acid linear alkyl ester and (meth) acrylic acid cyclic alkyl ester having an alkyl substituent having 4 or more carbon atoms are used in combination from the viewpoint of the affinity between the polymer emulsifier and tackifier resin to be produced. It is preferable to do. Examples of the (meth) acrylic acid linear alkyl ester having an alkyl substituent having 4 or more carbon atoms include n-butyl (meth) acrylate, and examples of the (meth) acrylic acid cyclic alkyl ester include cyclohexyl (meth) acrylate. Can be mentioned. In addition, (B) component may be used individually, respectively, and both may be used together.

The polymer emulsifier used in the present invention is mainly composed of the components (A) and (B), but by using a reactive emulsifier (C) (hereinafter referred to as component (C)), Adhesiveness can be further improved. The component (C) used in the present invention is a surfactant having a hydrophilic group and a hydrophobic group and having a carbon-carbon double bond in the molecule. Examples of the carbon-carbon double bond include functional groups such as a (meth) allyl group, 1-propenyl group, 2-methyl-1-propenyl group, vinyl group, isopropenyl group, and (meth) acryloyl group. . Specific examples of the reactive emulsifier include, for example, a polyoxyethylene alkyl ether having at least one functional group in the molecule, a sulfosuccinic acid ester salt of polyoxyethylene alkyl ether having at least one functional group in the molecule, Sulfate ester salt of polyoxyethylene alkyl ether having at least one functional group in the molecule, polyoxyethylene phenyl ether having at least one functional group in the molecule, poly having at least one functional group in the molecule Sulfosuccinic acid ester salt of oxyethylene phenyl ether, sulfate of polyoxyethylene phenyl ether having at least one functional group in the molecule, polyoxyethylene alkyl phenyl ether having at least one functional group in the molecule, A sulfosuccinic acid ester salt of polyoxyethylene alkylphenyl ether having at least one functional group in the molecule, a sulfate ester salt of polyoxyethylene alkylphenyl ether having at least one functional group in the molecule, and the functional group in the molecule A polyoxyethylene aralkylphenyl ether having at least one functional group, a sulfosuccinic acid ester salt of polyoxyethylene aralkylphenyl ether having at least one functional group in the molecule, and a polyoxyethylene aralkyl having at least one functional group in the molecule Sulfate ester salt of phenyl ether, polyoxyethylene alkylphenyl ether phosphate ester salt having at least one functional group in the molecule, polyoxyethylene having at least one functional group in the molecule Alkyl phenyl ether aliphatic or aromatic carboxylates, acidic phosphoric acid (meth) acrylate ester emulsifiers, acid anhydride modified products of rosin glycidyl ester acrylate (see JP-A-4-256429), JP-A Examples thereof include various emulsifiers described in JP-A 63-23725, JP-A 63-240931, and JP-A 62-104802. Furthermore, what replaced polyoxyethylene in the said reactive emulsifier with polyoxypropylene or the block copolymerization or random copolymerization of polyoxyethylene and polyoxypropylene is mentioned. In the present invention, such reactive emulsifier can be used without any particular limitation.

  Examples of commercially available products of the component (C) include KAYAMER PM-1 (trade name, manufactured by Nippon Kayaku Co., Ltd.), KAYAMER PM-2 (trade name, manufactured by Nippon Kayaku Co., Ltd.), KAYAMER PM- 21 (trade name, manufactured by Nippon Kayaku Co., Ltd.), SE-10N (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), NE-10 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), NE-20 ( Product name, manufactured by Asahi Denka Kogyo Co., Ltd.), NE-30 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), Adekaria Soap SR-10 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), Adekaria Soap SR-20 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), Adekaria Soap ER-20 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), New Frontier A229E (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ), New Frontier N117E (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) , New Frontier N250Z (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Aqualon RN-10 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Aqualon RN-20 (trade name, Daiichi Kogyo Seiyaku Co., Ltd.) ), Aqualon RN-50 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Aqualon HS-10 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Aqualon KH-05 (trade name, Daiichi Industrial Pharma Co., Ltd.), Aqualon KH-10 (trade name, Daiichi Kogyo Seiyaku Co., Ltd.), Eminol JS-2 (trade name, Sanyo Chemical Industries, Ltd.), Laterum K-180 (trade name) , Manufactured by Kao Corporation) and the like. The component (C) is preferably a polyoxyethylene phenyl ether type from the viewpoint of polymerizability and the emulsifying properties of the resulting polymer emulsifier, and an unsaturated sulfone having a structure in which 5 to 20 moles of an alkylene oxide chain are polymerized. It is particularly preferred to use acid salts. As these commercial products, Adekaria soap SR-10 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), Adekaria soap SR-20 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), Aqualon KH-05 ( Trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and Aqualon KH-10 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) are preferred.

In the present invention, in addition to the component (C), a reactive monomer (D) other than the components (A) to (C) (hereinafter referred to as the component (D)) can also be used. As the component (D), amide monomers such as (meth) acrylamide and N-methylol (meth) acrylamide; nitrile monomers such as (meth) acrylonitrile; vinyl ester monomers such as vinyl acetate; Hydroxy group-containing (meth) acrylic acid ester monomers such as (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, and (meth) acrylic acid 2-hydroxybutyl; Polyoxyalkylene (meth) acrylic acid ester monomers such as monomers; in addition, phosphoric acid ester vinyls such as methyl vinyl ether, glycidyl (meth) acrylate, urethane acrylates, diphenyl-2 (meth) acryloyloxyphosphate Monomer, α-olefin having 6 to 22 carbon atoms, vinyl pyro Don and the like.

  In the present invention, a copolymer obtained by copolymerization by various known methods using the components (A) and (B) and, if necessary, the components (C) and (D), is used as a polymer emulsifier. The amount of each constituent component of the polymer emulsifier used in the present invention is the component (A) and the component (B), and further when the component (C) and the component (D) are used, The glass transition point before neutralization of the copolymer is appropriately determined so as to be 110 ° C. or lower. The amount of each component used is usually about 10 to 90% by weight of component (A) and about 10 to 90% by weight of component (B), preferably 20 to 80% by weight of component (A) and component (B). 20 to 80% by weight. When the component (C) is used, the component (A) is about 10 to 50% by weight, the component (B) is about 10 to 50% by weight, and the component (C) is about 10 to 50% by weight. The component is 20 to 50% by weight, the component (B) is 20 to 50% by weight, and the component (C) is 20 to 50% by weight.

  In the said copolymer, when the usage-amount of each structural component is less than the said range, it exists in the tendency for the performance as a polymer emulsifier of the obtained copolymer to fall. That is, when the amount of component (A) used is less than 10% by weight, the resulting emulsion has low emulsifiability and may separate over time. On the other hand, when it exceeds 90% by weight, the viscosity of the polymer emulsifier to be produced increases, and the workability is remarkably lowered and the water resistance tends to be deteriorated. When the amount of the component (B) used is less than 10% by weight, the hydrophobic component is insufficient, so the balance as an emulsifier is lost, and it is difficult to obtain a stable emulsion. There is a possibility that the hydrophobic component becomes excessive and it does not function as an emulsifier. Further, when the component (C) is used, the initial adhesiveness tends to decrease when the amount of the component (C) used is less than 10% by weight, and further when the amount exceeds 50% by weight. The effect of improving the initial bonding performance is not seen, and is unnecessary from an economic viewpoint.

  When the component (D) is used, the proportion of the component (D) is 20% by weight or less, preferably 15% by weight or less of the constituent of the polymer emulsifier. When the component (D) exceeds 20% by weight, the emulsifiability of the resulting polymer emulsifier tends to decrease, such being undesirable.

  As a polymerization method for obtaining the copolymer (polymer emulsifier), various known methods such as solution polymerization, emulsion polymerization and suspension polymerization can be employed as they are. The component (A) may be partially neutralized or completely neutralized before polymerization to form a salt, or may be partially neutralized or completely neutralized to form a salt after polymerization.

  As the solvent used for the solution polymerization, benzene, toluene, xylene, hexane, cyclohexane, methanol, ethanol, isopropyl alcohol, ethyl acetate, acetone, methyl isobutyl ketone, dioxane, dimethylformamide, dimethyl sulfoxide and the like can be used.

  In the case of emulsion polymerization, a non-reactive emulsifier usually used for emulsion polymerization may be used. Examples of such emulsifiers include dialkyl sulfosuccinic acid ester salts, alkane sulfonic acid salts, α-olefin sulfonic acid salts, polyoxyethylene alkyl ether sulfosuccinic acid ester salts, polyoxyethylene styryl phenyl ether sulfosuccinic acid ester salts, and naphthalene sulfonic acid formalin condensation. Products, anionic emulsifiers such as polyoxyethylene alkyl ether sulfates and polyoxyethylene alkylphenyl ether sulfates, and nonionic emulsifiers such as polyoxyethylene alkyl ethers, polyoxyethylene styryl phenyl ethers and polyoxyethylene sorbitan fatty acid esters Is mentioned. These emulsifiers can be used alone or in appropriate combination of two or more. The amount used is usually 100 with respect to 100 parts by weight of the total charge of component (A) and component (B) (component (C), component (D) when all of these components are used). About part by weight or less, preferably about 0.1 to 50 parts by weight. In addition, since (C) component has an emulsification capability, an emulsifier is not particularly required, but the non-reactive emulsifier may be used.

  The polymerization initiator used in the polymerization is not particularly limited, and various known ones such as persulfates, peroxides, azo compounds, and redox initiators can be used.

  In order to produce a tackifier resin emulsion containing no solvent, it is necessary to employ an emulsion polymerization method or a suspension polymerization method.

    The glass transition point before neutralization of the copolymer (polymer emulsifier) must be 110 ° C. or less. When it exceeds 110 ° C., the initial adhesion performance is deteriorated, and the storage stability of the tackifier resin emulsion produced without using a solvent is deteriorated, which is not preferable. In addition, it is preferable for the glass transition point to be 85 ° C. or less because the initial adhesion performance is remarkably improved. Moreover, since the molecular weight of the copolymer (polymer emulsifier) directly correlates with the dispersibility of the emulsion of the tackifier resin, it is usually preferable that the weight average molecular weight is 1,000 to 200,000. A known chain transfer agent can be used to adjust the molecular weight. Examples of the chain transfer agent include isopropyl alcohol, carbon tetrachloride, ethylbenzene, isopropylbenzene, cumene, thioglycolic acid ester, alkyl mercaptan, 2,4-diphenyl-4-methyl-1-pentene, and the like. The amount of chain transfer agent used is usually 0.5 with respect to the total charge of component (A) and component (B) (component (C), component (D) when all of these components are used). ˜30% by weight.

  In this invention, tackifier resin is emulsified using the copolymer (polymer emulsifier) obtained above, and tackifier resin emulsion is manufactured.

  Various known tackifiers can be used as the tackifier used in the present invention. For example, rosins, rosin derivatives, petroleum resins, terpene resins and the like can be used, and one of these can be used alone or two or more can be used as a mixture.

Examples of rosins include raw rosin of gum rosin, wood rosin or tall oil rosin, stabilized rosin or polymerized rosin obtained by disproportionating or hydrogenating the raw rosin. Examples of the rosin derivative include rosin esters and rosin phenols. As the rosin ester, the rosin ester obtained by esterifying the rosin and the polyhydric alcohol, the raw rosin is partially fumarated or maleated, and then partially maleated or partially fumarated obtained by esterification. Polyhydric alcohol ester of rosin, partial maleated or partially fumarated disproportionated rosin polyhydric alcohol ester obtained by partially fumarating or maleating raw material rosin and then disproportionating and then esterifying Say. The rosin phenols are those obtained by adding phenols to rosins and thermally polymerizing them, or subsequently esterifying them. The polyhydric alcohol used for the esterification is not particularly limited, and diethylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, penta Various well-known things, such as erythritol, can be illustrated.
The petroleum resins are C5 petroleum resins, C9 petroleum resins, C5-C9 copolymer petroleum resins, coumarone resins, coumarone-indene resins, pure monomer resins, dicyclopentadiene petroleum resins, and hydrides thereof. Examples of terpene resins include α-pinene resins, β-pinene resins, and aromatic-modified terpene resins obtained by copolymerizing terpenes such as α-pinene and β-pinene with aromatic monomers such as styrene. Resins and their hydrides can be exemplified. Among these tackifiers, the use of rosin esters is preferable because the adhesion to the substrate is improved. The softening point of these tackifier resins is not particularly limited, and those having a high softening point of 200 ° C. or lower can be appropriately selected and used according to various applications.

  In the tackifier resin emulsion of the present invention, the components (A) and (B) (when the components (C) and (D) are used, the components (A) and (B) and these components) are combined. The tackifier resin is emulsified using a polymer emulsifier obtained by polymerization, and a low molecular emulsifier can also be used. In the present invention, the low molecular emulsifier usually refers to those having a molecular weight of about 1000 or less. The low molecular emulsifier is not particularly limited, and known ones can be used. Specifically, for example, when the components (A) and (B), the component (C), and the component (D) are used, the components (A) and (B) and these components are polymerized to form the present invention. In addition to those used in the production of the polymer emulsifier, the component (C) used in the production of the polymer emulsifier of the present invention can be used. Among these, organic sulfonates or sulfate esters are exemplified. Examples of the organic sulfonate include dodecylbenzene sulfonic acid, sodium polyoxyethylene lauryl ether sulfate, and the like. Examples of the sulfate ester salt include sodium polyoxyethylene lauryl ether sulfate. In addition, it is preferable to use the low-molecular emulsifier together with the polymer emulsifier because emulsification is improved.

Although the usage-amount of a polymeric emulsifier is not specifically limited, It is about 1-10 weight part normally in conversion of solid content with respect to 100 weight part of tackifier resin, Preferably it is 2-7 weight part. If it exceeds 10 parts by weight, the water resistance of the resulting aqueous adhesive composition is lowered, and if it is less than 1 part by weight, it becomes difficult to obtain a stable resin emulsion. Although the usage-amount of an anionic low molecular emulsifier is not specifically limited, About 1-10 weight part normally in conversion of solid content with respect to 100 weight part of tackifier resin, Preferably it is about 2-7. When the amount exceeds 10 parts by weight, the water resistance tends to decrease. When the amount is less than 1 part by weight, the emulsifiability is insufficient and it becomes difficult to obtain a stable resin emulsion.

  As the emulsification method, a conventionally known high-pressure emulsification method, inversion emulsification method, or the like can be employed. Specifically, (i) the tackifier resin is dissolved in a solvent such as benzene or toluene, the polymer emulsifier and soft water are added, and the mixture is emulsified using a high-pressure emulsifier, and then the solvent is removed under reduced pressure. Method, (ii) Mixing a small amount of solvent such as benzene, toluene, etc. with the tackifier resin, then kneading the emulsifier, and gradually adding hot water, followed by phase inversion emulsification to obtain an emulsion (Iii) raising the temperature above the softening point of the resin under pressure or normal pressure, kneading the emulsifier, gradually adding hot water and emulsifying the emulsion by phase inversion emulsification. And the like. In addition, when manufacturing the tackifier resin emulsion which does not contain a solvent, it is necessary to employ | adopt the said (iii) method.

The solid content concentration of the tackifier resin emulsion thus obtained is not particularly limited, but it is usually adjusted appropriately so as to be about 20 to 70% by weight. Moreover, the average particle diameter of the obtained emulsion is usually about 0.2 to 2 μm, and most of them are uniformly dispersed as particles of 0.5 μm or less. The emulsion exhibits a white to milky white appearance and has a pH of about 2 to 9. In addition, it is preferable from the surface of health and safety that the organic solvent content of the tackifier resin emulsion is 500 ppm or less. Such a tackifier resin emulsion can be obtained by adopting the method (iii).

  The adhesive composition of the present invention contains the tackifier resin emulsion, specifically, for example, at least selected from the group consisting of an acrylic polymer emulsion, a rubber latex, and a synthetic resin emulsion. The tackifier resin emulsion is blended with a kind of base polymer.

There is no restriction | limiting in particular as an acrylic polymer emulsion used together with the said tackifier resin emulsion, Various things can be used. The acrylic polymer emulsion can be easily produced by a known emulsion polymerization method such as a batch charging method of (meth) acrylic acid ester, a monomer sequential addition polymerization method, an emulsion monomer sequential addition polymerization method, or a seed polymerization method. it can.

Examples of the (meth) acrylic acid ester to be used include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and glycidyl (meth) acrylate. , (Meth) acrylic acid 2-hydroxyethyl and the like, and these may be used alone or in admixture of two or more. Further, in order to impart storage stability to the resulting acrylic polymer emulsion, a small amount of (meth) acrylic acid may be used instead of the (meth) acrylic acid ester. Furthermore, if desired, copolymerizable monomers such as vinyl acetate and styrene can be used in combination so long as the adhesive properties of the (meth) acrylic acid ester polymer are not impaired. In addition, as an emulsifier used for an acrylic polymer emulsion, various well-known things, such as an anionic emulsifier, a nonionic emulsifier, partially saponified polyvinyl alcohol, can be used, and the usage-amount is 0 with respect to 100 weight part of polymers. About 1 to 5 parts by weight, preferably 0.5 to 3 parts by weight.

  The proportion of the acrylic polymer emulsion and the tackifier resin emulsion used is usually about 10 to 100 parts by weight (in terms of solid content) of the tackifier resin emulsion with respect to 100 parts by weight (in terms of solid content) of the acrylic polymer emulsion. ) Is preferable. When the tackifier resin emulsion is less than 10 parts by weight, the modification by adding the tackifier resin may be hardly observed, and when it exceeds 100 parts by weight, the cohesive force is reduced. There is a tendency.

  Moreover, as rubber latex, various well-known things used for an aqueous | water-based adhesive / adhesive composition can be used. Examples thereof include natural rubber latex, styrene-butadiene copolymer latex, chloroprene latex and the like.

  The ratio of the rubber latex and the tackifier resin emulsion used is usually about 10 to 150 parts by weight (in terms of solid content) of the tackifier resin emulsion with respect to 100 parts by weight of the rubber latex (in terms of solid content). Is preferred. When the tackifier resin emulsion is less than 10 parts by weight, there may be little modification by adding the tackifier resin, and when it exceeds 150 parts by weight, the cohesive force tends to decrease. It is in.

  Further, as the synthetic resin emulsion, various known ones used in aqueous adhesive compositions can be used, for example, synthetic resin emulsions such as vinyl acetate emulsion, ethylene-vinyl acetate copolymer emulsion, urethane emulsion and the like. It is done.

  The ratio of the synthetic resin emulsion and the tackifier resin emulsion used is about 10 to 100 parts by weight (solid content conversion) of the addition amount of the tackifier resin emulsion to 100 parts by weight (solid content conversion) of the synthetic resin emulsion. ) Is preferred. When the tackifier resin emulsion is less than 10 parts by weight, the modification by adding the tackifier resin may be hardly observed, and when it exceeds 100 parts by weight, the cohesive force is reduced. There is a tendency.

The aqueous adhesive composition of the present invention comprises at least one base polymer selected from the group consisting of an acrylic polymer emulsion, a rubber latex and a synthetic resin emulsion, and a tackifier resin emulsion as essential components. In addition to these, an antifoaming agent, a thickener, a filler, an antioxidant, a water-resistant agent, a film-forming aid, a water retention agent, and the like can be added as necessary.

  Hereinafter, the production method and the like of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The analysis of the polymer emulsifier and the resin emulsion was performed by the following method.

Glass transition point (Tg)
The polymer emulsifier before saponification was dried under reduced pressure at 105 ° C. for one day to obtain a film. Using a thermal stress strain measuring device (TMA) manufactured by Seiko Instruments Inc., a 5 g load was applied to the film-like material via a needle probe, and the temperature was raised from room temperature at a constant rate (10 ° C./min). The glass transition point (° C.) was determined from the transition curve.

Viscosity A solution viscosity (mPa · s) was measured at 25 ° C. and a rotation speed of 30 rpm using a B-type viscometer B8M manufactured by Tokimec Co., Ltd.

Storage stability The obtained resin emulsion was allowed to stand at 25 ° C. for 10 days, and the presence or absence of sediment was visually determined.

Production Example 1
A reaction vessel equipped with a stirrer, a reflux tube, a thermometer, and a nitrogen inflow tube was charged with 33 parts of an anionic reactive emulsifier (Aquaron KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 210 parts of water. A uniform aqueous solution was obtained. The temperature was raised to 95 ° C. under a nitrogen stream, and a solution consisting of 33 parts of methacrylic acid, 14 parts of butyl acrylate, 20 parts of cyclohexyl acrylate, 1 part of n-dodecyl mercaptan, and an aqueous solution consisting of 1.5 parts of APS and 15 parts of water was gradually added. It was dripped at and reacted for 3 hours. Furthermore, the aqueous solution which consists of 0.5 parts of APS and 5 parts of water was dripped, and it was made to react for 2 hours. Subsequently, 30 parts of 48% sodium hydroxide and 220 parts of water were added to obtain a polymer emulsifier having a solid content of 20.0%, a pH of 7.9, and a viscosity of 790 mPa · s. The glass transition point of the resin before saponification was 52 ° C.

Production Examples 2-11
A polymer emulsifier was produced in the same manner as in Production Example 1, except that each compounding component was changed as shown in Table 1. The properties of the obtained polymer emulsifier are shown in Table 1.

(Manufacture of resin emulsion)
Examples 1-9 and Comparative Examples 1-4
Glycerin ester of gum rosin (A-100, manufactured by Arakawa Chemical Industries, Ltd.), pentaerythritol ester of gum rosin (GA-100, manufactured by Arakawa Chemical Industries, Ltd.), pentaerythritol ester of disproportionated rosin (GB-120, Arakawa Chemical Industries, Ltd.) as a tackifier resin, 2 parts of the polymer emulsifier obtained in Production Examples 1 to 9, low molecular emulsifier (trade name Neogen AO-90, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts and 2 parts of a low molecular emulsifier (trade name: Hightenol 12, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were added and dispersed in water to obtain resin emulsions shown in Table 2. When the polymer emulsifiers obtained in Production Examples 9 and 10 were used, emulsification could not be performed.

Evaluation of adhesive performance of water-based emulsion adhesive Water-based emulsion adhesive comprising 100 parts (solid part) of an aqueous acrylic polymerized emulsion, 70 parts (solid part) of a resin emulsion, 250 parts of calcium carbonate, and 40 parts of triethylene glycol Adjusted.
The initial adhesive evaluation was performed by applying the above adhesive composition to a fiber reinforced cement board with a comb iron, and after 40 minutes open time, the vinyl floor sheet was pressure-bonded with a hand roller, cured for 15 minutes, and then applied to one end of the sheet. A 200 g weight was suspended and peeled at 90 °, and the time (seconds) until peeling of the entire surface was measured. The longer the peeling time, the stronger the adhesion.
The results are shown in Table 2.

As shown in Examples 1 to 9 of Table 2, a good initial adhesive force can be obtained by blending the tackifier resin emulsion obtained in the presence of the polymer emulsifier of the present invention with an aqueous acrylic polymer emulsion adhesive. Can be granted.

Claims (9)

The tackifier resin is emulsified in the presence of a polymeric emulsifier composed mainly of an anionic monomer (A) and an alkyl (meth) acrylate (B) and having a glass transition point of 110 ° C. or lower. Obtained tackifier resin emulsion. 2. The tackifier according to claim 1, wherein the components used in the polymer emulsifier are 10 to 90% by weight of the anionic monomer (A) and 10 to 90% by weight of the (meth) acrylic acid alkyl ester (B). Agent resin emulsion. In the presence of a polymer emulsifier composed mainly of an anionic monomer (A), a (meth) acrylic acid alkyl ester (B) and a reactive emulsifier (C) and having a glass transition point of 110 ° C. or lower. The tackifier resin emulsion according to claim 1, obtained by emulsifying a tackifier resin. The constituent ratio of the polymer emulsifier is 10 to 50% by weight of the anionic monomer (A), 10 to 50% by weight of the (meth) acrylic acid alkyl ester (B), and 10 to 50 of the reactive emulsifier (C). The tackifier resin emulsion according to claim 3, wherein the tackifier resin emulsion is by weight. The tackifier according to claim 3 or 4, wherein the reactive emulsifier (C) constituting the polymer emulsifier is an unsaturated sulfonate having a structure in which 5 to 20 mol of an alkylene oxide chain is polymerized. Agent resin emulsion. The tackifier resin emulsion according to any one of claims 1 to 5, wherein a low molecular emulsifier is used in combination with the high molecular emulsifier. The tackifier resin emulsion according to any one of claims 1 to 6, wherein the low molecular emulsifier is an organic sulfonate or a sulfate ester salt. Content of an organic solvent is 500 ppm or less, The tackifier resin emulsion in any one of Claims 1-7. An adhesive composition comprising the tackifier resin emulsion according to any one of claims 1 to 8.