JPH07331208A - Tackifier resin emulsion and water-based tack agent composition - Google Patents

Abstract

PURPOSE:To obtain an emulsion-type composition excellent in the stability to mechanical shear and heat resistance by emulsifying a tackifier resin in the presence of a polymeric emulsifier comprising a reactive emulsifier, styrene compound and anionic monomer. CONSTITUTION:This composition is obtained by emulsifying a tackifier resin in the presence of a polymeric emulsifier consisting mainly of (A) 10-50wt.% of a reactive emulsifier, (B) 15-49wt.% of a styrene compound and/or (meth) acrylic alkyl ester and (C) 40-80wt.% of an anionic monomer. Furthermore, (D) <=20wt.% of a nonionic monomer may be incorporated in the above composition. The tackifier resin is e.g. a rosin, rosin derivative, petroleum-based resin or terpene resin. The other objective emulsion is obtained by blending 100 pts.wt. of an acrylic polymer emulsion and/or latex for with 5-150 pts.wt. of the above emulsified composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to tackifier resin emulsions and aqueous pressure-sensitive adhesive compositions. More specifically, it relates to a tackifier resin emulsion capable of providing an aqueous pressure-sensitive adhesive composition having excellent mechanical stability and heat resistance.

[0002]

BACKGROUND OF THE INVENTION Adhesives are applied to papers, plastic films, etc., and are applied to tapes, sheets, labels, etc. Generally, they are applied to a base resin such as an acrylic polymer or the like, such as tacks. Tackifier resins have been added and used to impart properties. In addition, as the pressure-sensitive adhesive, a solvent type has been generally used in the past, but in recent years, an aqueous emulsion has various advantages such as no air pollution, excellent safety and health, and suitability for resource saving. It tends to be converted to mold adhesive.

As the applications of such water-based emulsion type adhesives expand, the required performance becomes higher, and one of the required performances is the stability of the emulsion, especially the stability against mechanical shear. Came to be. Here, the stability against mechanical shear refers to the stability against mechanical shear added in conventionally known gear pumps, roll coating machines, etc., and the spray coating that has been increasing in coating systems in recent years. It refers to the stability against mechanical shear that is added at the time of work.If the stability against such mechanical shear is inferior, aggregates occur in the emulsion, reducing the commercial value of tapes, sheets, labels, etc. There was a problem of causing it.

In order to improve the stability against such mechanical shear, a method of adjusting the type or amount of an emulsifier used in a base resin such as an acrylic polymer emulsion or a tackifier resin emulsion is studied. However, it has not been sufficiently improved. Further, a method of adding a water-soluble polymer such as polyacrylic acid to a base resin and a tackifier resin emulsion has been proposed, but an aqueous emulsion-type adhesive having good stability against mechanical shear is still obtained. Not not.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an emulsion type water-based pressure-sensitive adhesive composition having good stability against mechanical shear.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned problems of the prior art, and as a result, the reaction mixture contains a reactive emulsifier as an emulsifier of a tackifier resin emulsion. It has been found that an aqueous pressure-sensitive adhesive composition having extremely good stability against mechanical shear can be obtained by using the specific polymer emulsifier. The present invention has been completed based on this new finding.

That is, according to the present invention, the reactive emulsifier (A), styrenes and / or (meth) acrylic acid alkyl ester (B) {in the present invention, the (meth) acrylic acid alkyl ester is an acrylic acid alkyl ester and / or It also means an alkyl methacrylate. Below (meta) has the same meaning. }
And a tackifier resin emulsion obtained by emulsifying a tackifier resin in the presence of a polymeric emulsifier composed mainly of an anionic monomer (C). Further, the present invention relates to an aqueous pressure-sensitive adhesive composition containing an acrylic polymer emulsion and / or latex for pressure-sensitive adhesive, and the tackifier resin emulsion.

As the tackifier resin used in the present invention, various known resins can be used. Examples thereof include rosins, rosin derivatives, petroleum-based resins, terpene-based resins, and the like, and one of these can be used alone or two or more can be used as a mixture.

Examples of rosins include gum rosin, wood rosin, tall oil rosin raw material rosin, stabilized rosin obtained by disproportionating or hydrogenating the raw material rosin, and polymerized rosin. Examples of rosin derivatives include rosin esters and rosin phenols. As the rosin ester, a rosin ester obtained by subjecting the rosin and a polyhydric alcohol to an esterification reaction, partially fumarized or maleated from a raw material rosin, and then partially maleated or partially fumarized by esterification Polyhydric alcohol ester of rosin, polymaleic alcohol ester of partially maleated or partially fumarized disproportionated rosin obtained by partially fumarizing or maleating raw material rosin, and then disproportionating Say. Further, 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 includes diethylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, penta Various publicly known substances such as erythritol can be exemplified.

The petroleum resin is a C5 petroleum resin, C
Examples include 9-based petroleum resin, C5-C9 copolymer-based petroleum resin, coumarone resin, coumarone-indene-based resin, pure monomer resin, dicyclopentadiene-based petroleum resin and hydrides thereof, and the terpene-based resin is α- Examples thereof include a pinene resin, a β-pinene resin, an aromatic-modified terpene resin obtained by copolymerizing a terpene such as α-pinene and β-pinene with an aromatic monomer such as styrene, and a hydride thereof.

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 present invention, the tackifier resin is composed mainly of a reactive emulsifier (A), styrenes and / or (meth) acrylic acid alkyl ester (B) and an anionic monomer (C). Emulsification in the presence of a polymeric emulsifier to produce a tackifier resin emulsion.

The reactive emulsifier (A) 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 (meth) allyl group, 1-propenyl group,
Functional groups such as 2-methyl-1-propenyl group, vinyl group, isopropenyl group, (meth) acryloyl group and the like can be mentioned. Specific examples of the reactive emulsifier include, for example, polyoxyethylene alkyl ether having at least one functional group in the molecule, 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, sulfuric acid ester salt of polyoxyethylene phenyl ether having at least one functional group in the molecule, polyoxyethylene alkylphenyl ether having at least one functional group in the molecule, At least one functional group in a molecule
Sulfosuccinate ester salt of polyoxyethylene alkylphenyl ether having one, sulfuric acid ester salt of polyoxyethylene alkylphenyl ether having at least one functional group in the molecule, polyoxyethylene having at least one functional group in the molecule Aralkyl phenyl ether, sulfosuccinic acid ester salt of polyoxyethylene aralkyl phenyl ether having at least one functional group in the molecule, sulfate ester salt of polyoxyethylene aralkyl phenyl ether having at least one of the functional group in the molecule, A phosphoric acid ester salt of a polyoxyethylene alkylphenyl ether having at least one functional group in the molecule, a polyoxyethylene alkylphenyl ether having at least one functional group in the molecule, Aliphatic or aromatic carboxylic acid salts, acidic phosphoric acid (meth) acrylic acid ester emulsifiers, acid anhydride modified product of rosin glycidyl ester acrylate (see JP-A-4-256429), JP 63-2372
5, JP-A-63-240931, JP-A-6-
Various compounds such as the emulsifiers described in JP-A-2-104802 can be mentioned. Furthermore, the polyoxyethylene in the reactive emulsifier may be replaced with polyoxypropylene or a block copolymer or random copolymer of polyoxyethylene and polyoxypropylene.
In the present invention, such reactive emulsifier can be used without particular limitation.

Commercially available products of the above-mentioned (A) reactive emulsifiers include, for example, (trade name KAYAMER PM-1, manufactured by Nippon Kayaku Co., Ltd.), (trade name KAYAMER PM-2, manufactured by Nippon Kayaku Co., Ltd.). , (Product name KAYAMER PM-2
1, manufactured by Nippon Kayaku Co., Ltd., (trade name SE-10N, manufactured by Asahi Denka Kogyo Co., Ltd.), (trade name NE-10, manufactured by Asahi Denka Kogyo Co., Ltd.), (trade name NE-20, Asahi Denka Co., Ltd.
Manufactured), (trade name NE-30, manufactured by Asahi Denka Kogyo Co., Ltd.),
(Product name New Frontier A229E, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), (Product name New Frontier N-117
E, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., (trade name New Frontier N250Z, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), (trade name Aqualon RN-10, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), (trade name) Aqualon RN-20, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.,
(Brand name Aqualon RN-50, Daiichi Kogyo Seiyaku Co., Ltd.)
(Product name), (Product name Aqualon HS-10, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), (Product name Eminor JS-2, Sanyo Kasei Co., Ltd.), (Product name Laterum K-180, Kao Corporation)
Manufactured) is a typical example. Among the reactive emulsifiers, polyoxyethylene phenyl ether-based ones are preferable from the viewpoint of polymerizability and emulsification property of the obtained polymer emulsifier, and commercially available products include (trade name: Aqualon RN-1).
0, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., (trade name: Aqualon RN)
-20, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., (trade name: Aqualon RN-50, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) are preferable.

Among the styrenes and / or (meth) acrylic acid alkyl ester (B), examples of the styrenes include styrene, α-methylstyrene, vinyltoluene and the like. Among these, styrene and α-methylstyrene are preferable from the viewpoint of affinity with the tackifying resin. Examples of alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and (meth).
Iso-propyl acrylate, n- (meth) acrylate
Butyl, iso-butyl (meth) acrylate, (meth)
Examples thereof include 2-ethylhexyl acrylate and stearyl (meth) acrylate. Among these, methyl (meth) acrylate is preferable from the viewpoint of affinity with the tackifier resin.

These styrenes and alkyl (meth) acrylates may be used alone or in combination. In the present invention, in consideration of the affinity with the tackifier resin, it is preferable to use both styrenes and alkyl (meth) acrylate in combination.
The ratio when both are used in combination is styrene based on weight:
(Meth) acrylic acid alkyl ester = 1: 2 to 5:
2, preferably in the range of 1: 2 to 2: 1.

Examples of the anionic monomer (C) include monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid,
Carboxylic acids such as dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid and muconic acid; organic sulfonic acids such as vinyl sulfonic acid, styrene sulfonic acid and 2-acrylamido-2-methylpropane sulfonic acid; 2- Phosphoric acid vinyl monomers such as (meth) acryloyloxyethyl acid phosphate; and alkali metal salts such as sodium salts and potassium salts of these various organic acids, alkaline earth metal salts, ammonium salts, salts of organic bases, etc. can give. Among these anionic monomers (C), methacrylic acid and styrenesulfonic acid are preferable from the viewpoints of emulsifying property of the obtained polymer emulsifier and affinity with the tackifier resin. Particularly, styrenesulfonic acid is preferable from the viewpoint of affinity with the tackifying resin.

The anionic monomer (C) may be used alone or in combination of two or more kinds. In the present invention, it is preferable to use the carboxylic acid and the organic sulfonic acid together in view of the emulsifying property of the obtained polymer emulsifier and the affinity with the tackifier resin. When used in combination, the ratio is carboxylic acids: organic sulfonic acids = 1: 1 by weight.
It is preferable that the range is ˜6: 1, preferably 3: 2 to 5: 1.

In the present invention, a nonionic monomer (D) other than the component (B) can be used in addition to the components (A), (B) and (C). Examples of the nonionic monomer (D) include amide monomers such as (meth) acrylamide and N-methylol (meth) acrylamide;
Nitrile-based monomers such as (meth) acrylonitrile; vinyl ester-based monomers such as vinyl acetate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2- (meth) acrylic acid Hydroxy group-containing (meth) acrylic acid ester-based monomers such as hydroxybutyl; polyoxyalkylene (meth) acrylic acid ester-based monomers such as polyoxyalkylene-based monomers; methyl vinyl ether and glycidyl (meth) ) Acrylate, urethane acrylates, diphenyl-2
Examples thereof include phosphoric acid ester vinyl monomers such as (meth) acryloyloxyphosphate, α-olefins having 6 to 22 carbon atoms, and vinylpyrrolidone.

In the present invention, a copolymer obtained by copolymerizing the above-mentioned components (A), (B) and (C), and optionally (D) by various known methods is used as a polymer emulsifier. To use as. The amount of each constituent component of the polymer emulsifier used in the present invention is appropriately determined in consideration of the mechanical stability of the obtained emulsion.

The amount of each constituent used is 10 to 50% by weight of the reactive emulsifier (A), styrene and / or (meth) acrylic acid alkyl ester (B) 15 to 40.
% By weight and 40 to 80% by weight of anionic monomer (C). Preferably, the reactive emulsifier (A) 10 to 45
% By weight, 15 to 35% by weight of styrene and / or (meth) acrylic acid alkyl ester (B) and 45 to 65% by weight of anionic monomer (C).

When the amount of each component used in the copolymer is less than the above range, the performance of the resulting copolymer as a polymeric emulsifier tends to decrease. That is, when the amount of the component (A) used is less than 10% by weight, the emulsifying property of the polymer emulsifier obtained and the emulsion particles of the tackifier resin of the present invention formed by using the polymer emulsifier If the amount of the component (A) used exceeds 50% by weight, the mechanical stability will decrease, and the water resistance of the resulting aqueous pressure-sensitive adhesive composition tends to decrease. When the amount of the component (B) used is less than 15% by weight, the storage stability and mechanical stability of the emulsion particles of the tackifier resin obtained are lowered, and the amount of the component (B) used is 40% by weight. If it exceeds the range, the emulsifiability in producing an emulsion of the tackifier resin tends to be lowered. Further, when the amount of the component (C) used is less than 40% by weight, the emulsifying property of the polymer emulsifier obtained and the emulsion particles of the tackifier resin of the present invention formed by using the polymer emulsifier When the amount of the component (C) used exceeds 80% by weight, the mechanical stability is lowered, and the water resistance of the resulting aqueous pressure-sensitive adhesive composition tends to be lowered.

When the nonionic monomer (D) is used, the proportion of the nonionic monomer (D) used is 20% by weight or less, preferably 15% by weight or less of the constituents of the polymeric emulsifier. It is good to say (D) 2 nonionic monomers
If the amount exceeds 0% by weight, the emulsifying property of the obtained polymer emulsifier tends to decrease, which is not preferable.

As the method for polymerizing the copolymer (polymeric emulsifier), various known methods such as solution polymerization, emulsion polymerization, suspension polymerization and the like can be directly adopted. The anionic monomer (C) may be partially neutralized or completely neutralized to form a salt before polymerization, or partially neutralized or completely neutralized after polymerization to form a salt. .

Solvents used for solution polymerization include 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, since the reactive emulsifier (A) has an emulsifying ability, an emulsifier is not particularly required, but an emulsifier usually used in 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,
Naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl ether sulfate ester salt, polyoxyethylene alkylphenyl ether sulfate ester salt and other anionic emulsifiers, polyoxyethylene alkyl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene sorbitan fatty acid ester And nonionic emulsifiers. These emulsifiers can be used alone or in an appropriate combination of two or more. The amount used is usually about 10% by weight or less, preferably 0.1% by weight based on the total amount of the above-mentioned components (A), (B) and (C), and optionally (D). It is set to about 10% by weight.

The polymerization initiator used in the above-mentioned polymerization is not particularly limited, and various ones such as persulfates, peroxides, azo compounds and redox type initiators can be used. Since the molecular weight of the copolymer (polymer emulsifier) is directly correlated with the dispersibility of the emulsion of the tackifier resin,
Usually, it is preferable that the weight average molecular weight is 1,000 to 200,000. A known chain transfer agent can be used to control 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 can be mentioned. The amount of the chain transfer agent used is the above-mentioned component (A), component (B) and component (C),
Also, it is usually about 0.5 to 30% by weight with respect to the total amount of the component (D) used as necessary.

In the present invention, the tackifier resin emulsion is produced by emulsifying the tackifier resin using the copolymer (polymer emulsifier) obtained above.

The amount of the polymeric emulsifier used is not particularly limited, but is usually about 1 to 10 parts by weight, preferably 2 to 7 parts by weight in terms of solid content, relative to 100 parts by weight of the tackifier resin. When it exceeds 10 parts by weight, the water resistance of the obtained aqueous pressure-sensitive adhesive composition is lowered, and when it is less than 1 part by weight, the storage stability and mechanical stability of the resin emulsion during emulsification are deteriorated.

As the emulsification method, the conventionally known high-pressure emulsification method, reverse emulsification method and the like can be adopted. Specifically, a method of dissolving the tackifier resin in a solvent such as benzene and toluene, and then adding the polymer emulsifier and soft water, emulsifying using a high-pressure emulsifier, and then removing the solvent under reduced pressure. A small amount of solvent such as benzene and toluene is mixed with the imparting agent resin, and then an emulsifier is kneaded, and then hot water is gradually added to obtain an emulsion by phase inversion emulsification, and then the solvent is removed under reduced pressure or Examples thereof include a method of using as it is, a method of elevating the temperature above the softening point of the resin under pressure or normal pressure, kneading the emulsifier, gradually adding hot water, and then phase inversion emulsifying to emulsify. .

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 and used. The average particle size 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 has a white to milky white appearance and has a pH of about 2-9.

The tackifier resin emulsion of the present invention obtained as described above is blended with an acrylic polymer emulsion as a base resin and / or a latex for pressure-sensitive adhesives to give tackiness to various aqueous pressure-sensitive adhesive compositions such as tack. It imparts properties and improves the mechanical shear of the aqueous pressure-sensitive adhesive composition.

As the acrylic polymer emulsion, those generally used for various acrylic pressure-sensitive adhesives can be used.
It can be easily produced by a known emulsion polymerization method such as a monomer sequential addition polymerization method, an emulsion monomer sequential addition polymerization method, and a seed polymerization method.

Examples of the (meth) acrylic acid ester used include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
Examples thereof include 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate. These may be used alone or in admixture of two or more. Further, in order to impart storage stability to the obtained emulsion, a small amount of (meth) acrylic acid may be used instead of the (meth) acrylic acid ester. If desired, to the extent that the adhesive properties of the (meth) acrylic acid ester polymer are not impaired, for example,
Copolymerizable monomers such as vinyl acetate and styrene can be used together. The glass transition temperature of the polymer containing these (meth) acrylic acid ester as a main component is usually about −70 to 0 ° C.,
It is preferably -60 to -10 ° C. If it exceeds 0 ° C, the tack is remarkably lowered, which is not preferable. The emulsifier used in the acrylic polymer emulsion may be an anionic emulsifier, partially saponified polyvinyl alcohol, or the like, and the amount of the emulsifier used is 0.1 per 100 parts by weight of the polymer.
Is about 5 to 5 parts by weight, preferably 0.5 to 3 parts by weight.

The ratio of the acrylic polymer emulsion to the tackifier resin emulsion used is usually about 5 to 30 parts by weight of the tackifier resin emulsion with respect to 100 parts by weight of the acrylic polymer emulsion (solid content). It is preferable to use solid content conversion). When the tackifier resin emulsion is less than 5 parts by weight, almost no modification by the addition of the tackifier resin is observed, and 50
If the amount is more than parts by weight, the cohesive force tends to decrease, which is not suitable in any case.

Examples of the latex for adhesive include natural rubber latex, styrene-butadiene copolymer latex, chloroprene latex and the like. As the natural rubber latex, a known one used in an aqueous pressure-sensitive adhesive composition can be used, and it may be either depolymerized or non-depolymerized. As the styrene-butadiene copolymer latex and chloroprene latex, those commercially available for pressure-sensitive adhesives can be usually used. The styrene-butadiene copolymer latex and chloroprene latex may be carboxy-modified.

The ratio of the latex for tackiness agent to the tackifier resin emulsion used is usually about 5 to 150 parts by weight (solid content) of the tackifier resin emulsion to 100 parts by weight (solid content) of the latex for tackiness agent. (Converted) is recommended. When the amount of the tackifier resin emulsion is less than 5 parts by weight, almost no modification by the addition of the tackifier resin is observed, and when it exceeds 150 parts by weight, the cohesive force tends to decrease. Is also not appropriate.

In the aqueous pressure-sensitive adhesive composition of the present invention, an acrylic polymer emulsion as a base resin and a latex for pressure-sensitive adhesive may be used in combination, and if necessary, a defoaming agent, a thickener, a filler and an oxidizer. It is also possible to use an inhibitor, a water-proofing agent, a film-forming aid and the like.

[0039]

According to the tackifier resin emulsion obtained by the present invention, it is possible to provide an aqueous pressure-sensitive adhesive composition having good stability against mechanical high shear during gear pump, roll coating, spray coating, etc. The workability during coating can be greatly improved. Further, the obtained water-based pressure-sensitive adhesive composition has characteristics that it has excellent heat resistance as well as excellent adhesiveness similar to the conventional water-based pressure-sensitive adhesive composition.

[0040]

EXAMPLES The present invention will be described in detail below with reference to production examples, examples and comparative examples, but the present invention is not limited to these examples. In each example, parts and% are based on weight.

Production Example 1 (Production Example of Acrylic Polymer Emulsion) A four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel and a nitrogen inlet tube was placed under a nitrogen gas stream at 70 ° C.
43.40 parts of water and an anionic emulsifier (“Hitenol S”, solid content 50%, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 0.9
Two parts were dissolved. Also, (1) butyl acrylate 4
5.10 parts and acrylic acid 1.40 parts, (2) catalyst (potassium persulfate) 0.24 parts, pH adjuster (baking soda)
0.11 parts and 8.83 parts of water were added dropwise from separate dropping funnels in an amount of 1/10 and preliminarily reacted at 70 ° C. under a nitrogen gas stream for 30 minutes, and then (1)
And 9/10 amount of (2) was added dropwise over 2 hours. After all the amounts of (1) and (2) have been dropped,
Complete the reaction at 70 ° C for 1 hour, cool to room temperature, and then 10
Take out while performing 0 mesh wire mesh filtration, solid content 4
A 5.7% acrylic polymer emulsion was obtained.

Production Example 2 (Production Example of Polymer Emulsifier) A polyoxyethylene phenyl ether-based reactive emulsifier (trade name) was placed in a four-necked flask equipped with a nitrogen gas inlet tube, a thermometer, a reflux condenser and a stirrer. Aqualon RN-5
0, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., in terms of solid content, 25 parts, styrene 12.5 parts, methyl methacrylate 12.5 parts, methacrylic acid 40 parts and sodium styrene sulfonate 10
20 parts of water was added to prepare a transparent uniform system. Then, 1 part of dodecanethiol, 2 parts of benzoyl peroxide and 300 parts of water were mixed with this to initiate polymerization. After stirring at 65 ° C. for 2 hours, 28
% 29% aqueous ammonia was added, and the mixture was further stirred at 65 ° C. for 6 hours to complete the polymerization, and then cooled to room temperature. A dispersion liquid of a polymer emulsifier having a nonvolatile content of 22.5% and a weight average molecular weight of 32,000 was obtained.

Production Example 3 (Production Example of Polymer Emulsifier) A polyoxyethylene phenyl ether-based reactive emulsifier (trade name: Aqualon RN) was placed in the same reactor as in Production Example 2.
-20, Daiichi Kogyo Seiyaku Co., Ltd.) 15 parts, styrene 15
Parts, 20 parts of methyl methacrylate and 50 parts of methacrylic acid
20 parts of water was added to prepare a transparent uniform system. Next, 0.5 part of octanethiol, 2 parts of potassium persulfate and 300 parts of water were mixed with this to initiate polymerization. After stirring at 85 ° C for 2 hours, 1 part of potassium persulfate was added and the mixture was kept at the same temperature for 1 hour. 4 more
After adding 24 parts of 8% potassium hydroxide aqueous solution, it cooled to normal temperature. Nonvolatile content 24.3%, weight average molecular weight 3
A dispersion of 3500 polymeric emulsifiers was obtained.

Production Example 4 (Production Example of Polymer Emulsifier) A polyoxyethylene phenyl ether-based reactive emulsifier (trade name: Aqualon RN) was placed in the same reactor as in Production Example 2.
-10, Daiichi Kogyo Seiyaku Co., Ltd.) 20 parts, styrene 20
Parts, 15 parts of methyl methacrylate, 30 parts of methacrylic acid and 15 parts of sodium styrene sulfonate were charged, and further 20 parts of water was added to make the charged components a transparent homogeneous system. Next, 0.5 part of octanethiol, 2 parts of potassium persulfate and 300 of water were mixed with this to initiate polymerization. 8
After stirring at 5 ° C for 2 hours, 1 part of potassium persulfate was added and the mixture was kept at the same temperature for 1 hour. Further, 28.6 parts of a 48% potassium hydroxide aqueous solution was added and then cooled to room temperature.
A dispersion liquid of a polymer emulsifier having a nonvolatile content of 23.8% and a weight average molecular weight of 31,500 was obtained.

Production Example 5 (Production Example of Polymer Emulsifier) A polyoxyethylene phenyl ether-based reactive emulsifier (trade name: Aqualon RN) was placed in the same reactor as in Production Example 2.
-50, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 25 parts of methyl methacrylate, 45 parts of methacrylic acid and 15 parts of sodium styrene sulfonate were charged, and further 20 parts of water was added to the mixture to prepare a transparent homogeneous system. And Then, 5 parts of 2,4-diphenyl-4-methyl-1-pentene was added thereto,
Polymerization was initiated by mixing 2 parts of potassium persulfate and 300 of water. After stirring at 85 ° C for 2 hours, 1 part of potassium persulfate was added and the mixture was kept at the same temperature for 1 hour. Further, 24 parts of 48% potassium hydroxide aqueous solution was added, and then cooled to room temperature. A dispersion liquid of a polymer emulsifier having a nonvolatile content of 24.1% and a weight average molecular weight of 35,000 was obtained.

Production Example 6 (Production Example of Polymer Emulsifier for Comparative Example) 30 parts of styrene, 30 parts of methyl methacrylate and 40 parts of methacrylic acid were charged in the same reactor as in Production Example 2. Then, to this, 2,4-diphenyl-4-methyl-
Polymerization was initiated by mixing 5 parts of 1-pentene, 2 parts of potassium persulfate and 300 parts of water. After stirring at 85 ° C for 2 hours, 1 part of potassium persulfate was added and the mixture was kept at the same temperature for 1 hour. Further, 24 parts of 48% potassium hydroxide aqueous solution was added, and then cooled to room temperature. A dispersion liquid of a polymeric emulsifier having a nonvolatile content of 24.5% and a weight average molecular weight of 31,000 was obtained.

Example 1 100 parts of pentaerythritol ester (tackifier resin) of polymerized rosin having a softening point of 160 ° C. was dissolved in 60 parts of toluene at 100 ° C. for about 1 hour and then cooled to 80 ° C. Next, 3 parts of the polymer emulsifier obtained in Production Example 2 and 160 parts of water in terms of solid content were added, and preliminarily emulsified by strongly stirring at 75 ° C. for 1 hour. Further, the obtained preliminary emulsion is 300 by a high pressure emulsifying machine (manton gaurin company).
High pressure emulsification was performed at a pressure of kg / cm ² to obtain an emulsion. Next, 200 parts of the above emulsion was charged in a vacuum distillation apparatus and 50
Vacuum distillation was carried out for 8 hours under conditions of 100 ° C. and 100 mmHg to obtain a tackifier resin emulsion having a solid content of 50%.

20 parts of the emulsion of the polymerized rosin pentaerythritol ester thus obtained (in terms of solid content) and 80 parts of the acrylic polymer emulsion obtained in Production Example 1 (in terms of solid content) were mixed. An aqueous pressure-sensitive adhesive composition was obtained.

Example 2 A tackifier resin was prepared in the same manner as in Example 1 except that pentaerythritol ester of partially fumarized disproportionated rosin (softening point 125 ° C.) was used as the tackifier resin in Example 1. An emulsion of Further, an aqueous pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

Example 3 An emulsion of a tackifier resin was obtained in the same manner as in Example 1 except that glycerin ester of disproportionated rosin (softening point 100 ° C.) was used as the tackifier resin in Example 1. It was Further, an aqueous pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

Examples 4 to 6 In Example 1, instead of the polymer emulsifier obtained in Production Example 2, Production Example 3 (corresponding to Example 4), Production Example 4 (corresponding to Example 5) or production. An emulsion of the tackifier resin was obtained in the same manner as in Example 1 except that the polymer emulsifier obtained in Example 5 (corresponding to Example 6) was used. Further, an aqueous pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

Comparative Example 1 Tackification was carried out in the same manner as in Example 1 except that the polymeric emulsifier obtained in Production Example 6 was used in place of the polymeric emulsifier obtained in Production Example 2. An emulsion of the agent resin was obtained. Further, an aqueous pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

Comparative Example 2 Example 5 was repeated except that sodium dodecylbenzenesulfonate (trade name: Neogen R, manufactured by Kao Corporation) was used in place of the polymer emulsifier obtained in Production Example 2 in Example 1. An emulsion of the tackifier resin was obtained in the same manner as in 1.
Further, an aqueous pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

The aqueous pressure-sensitive adhesive compositions obtained in Examples and Comparative Examples were subjected to the following tests. The evaluation results are shown in Table 1.

(Stability to mechanical shear) The aqueous pressure-sensitive adhesive compositions prepared in Examples and Comparative Examples were further adjusted to pH 8 and nonvolatile content 30% with 28% ammonia water, and then subjected to a Marlon test. , Aggregate generation rate (%)
= (Aggregate / initial solid content) × 100 was calculated. Conditions of the Marlon test are load: 10 kg, rotation speed: 1000 r
pm, share time: 10 minutes.

(Heat Resistance) The water-based pressure-sensitive adhesive compositions prepared in Examples and Comparative Examples were applied onto a PET film and dried to prepare a pressure-sensitive adhesive tape having a film thickness of 30 μm.
A creep test was conducted by the method according to C-7 to evaluate heat resistance (holding power). Evaluation is temperature 60 ℃, load 1
It was expressed as a deviation (mm) when held for 2 hours under the condition of kg.

[0057]

[Table 1]

Claims (8)

[Claims] 1. In the presence of a polymeric emulsifier mainly composed of a reactive emulsifier (A), styrenes and / or (meth) acrylic acid alkyl ester (B) and an anionic monomer (C). , A tackifier resin emulsion obtained by emulsifying a tackifier resin. 2. The proportion of the constituents of the polymeric emulsifier used is
Reactive emulsifier (A) 10 to 50% by weight, styrene and / or (meth) acrylic acid alkyl ester (B)
15-40% by weight and anionic monomer (C) 40
The tackifier resin emulsion according to claim 1, which is -80% by weight. 3. The tackifier resin emulsion according to claim 1, which further comprises a nonionic monomer (D) other than (B) as a constituent component of the polymeric emulsifier. 4. The proportion of the nonionic monomer (D) used is
The tackifier resin emulsion according to claim 3, which is 20% by weight or less of the constituents of the polymeric emulsifier. 5. The tackifier resin emulsion according to claim 1, wherein the tackifier resin is at least one selected from rosins, rosin derivatives, petroleum resins and terpene resins. 6. An acrylic polymer emulsion and / or
Alternatively, an aqueous pressure-sensitive adhesive composition containing a latex for pressure-sensitive adhesive and the tackifier resin emulsion according to any one of claims 1 to 5. 7. The tackifier resin emulsion according to claim 1, which is used in an amount of 5 to 30 parts by weight (solid content) based on 100 parts by weight of acrylic emulsion (solid content). The aqueous pressure-sensitive adhesive composition according to claim 6. 8. The tackifier resin emulsion according to claim 1, which is used in an amount of 5 to 150 parts by weight (solid content) based on 100 parts by weight of adhesive latex (solid content). The aqueous pressure-sensitive adhesive composition according to claim 6.