JP2003073647A - Tackifier resin emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tackifier emulsion with enhanced heat resistance and good mechanical stability without detriment to self-adhesive properties. SOLUTION: The tackifier resin emulsion comprises a tackifier resin dispersed in water using an emulsifier, where the emulsifier is a polymer obtained by saponifying a copolymer having a brittle temperature of 110-150 deg.C. The emulsifier is a saponified product of a copolymer obtained by reacting a hydrophobic monomer, for example, styrenes, or (meth)acrylate esters with a polymerizable unsaturated organic acid such as unsaturated carboxylic acids, or unsaturated sulfonic acids. The use of the emulsifier gives to the tackifier resin emulsion advantages that it exhibits excellent self-adhesive properties and heat resistance and that it can secure the heat resistance even when a rosin tackifier resin whose softening point is not so high is employed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aqueous emulsion of a tackifier resin such as a rosin-based resin, a terpene-based resin, a petroleum-based resin, etc., while improving heat resistance without sacrificing tackiness and Provided is one having mechanical stability.

[0002]

2. Description of the Related Art Generally, a tackifier resin emulsion is added to a base resin such as an acrylic polymer or various latexes for the purpose of improving the adhesive properties and is used as various adhesives and adhesives. . In recent years, the form of viscous / adhesive is changing from the conventionally used solvent type to an aqueous emulsion type due to increasing awareness of environmental problems. However, as the use of such an aqueous emulsion type is widespread, it is required. Performance is also becoming more sophisticated. In particular, in terms of adhesive properties, it is not uncommon for various physical properties to conflict with each other, and it is required to improve these conflicting physical properties together so as to have performance equivalent to or better than that of the solvent type. In recent years, as one of such demands, it has become necessary to simultaneously improve heat resistance, which tends to conflict with this, while maintaining good adhesiveness (tack).

For the purpose of improving the tackiness property, the following are conventional techniques in which the type of tackifier resin constituting the aqueous emulsion is specified. (1) JP-A-5-31137 (Prior Art 1) Polymerized rosin for the purpose of improving tackiness and adhesive strength at normal temperature of polyolefin and adhesive strength at high temperature, which tend to conflict with each other. Obtained by reacting a polyhydric alcohol with a resin acid containing
A pressure-sensitive adhesive containing an aqueous emulsion of a rosin-based tackifier resin having a high softening point of ℃ or higher is disclosed.

(2) JP-A-6-264041 (Prior Art 2) Core of a tackifier resin having a chain transfer effect for the purpose of improving the adhesive force to polyolefin without lowering the adhesive holding force. Disclosed is a tackifier resin emulsion comprising an aqueous dispersion of a resin in which a shell is hybridized to a layer with a specific acrylic resin as a constituent and having a glass transition temperature of −85 ° C. to −30 ° C., and a hydrazine derivative. Has been done. The aqueous dispersion of the hybrid resin is prepared by previously dispersing a tackifier resin having a chain transfer effect in water to form an emulsion state, and then adding a monomer mixture capable of forming a shell layer and emulsion polymerizing the mixture. (See paragraph 24 of the publication). In this case, it is described that if the glass transition temperature of the shell layer is too low, the holding force is lowered, and conversely, if it is too high, the adhesive force is lowered (see paragraph 22 of the same publication).
Further, the hydrazine derivative is used in combination to secure the adhesive physical properties by crosslinking, and if the blending ratio is too small, the crosslinking will not be carried out sufficiently and the holding power will decrease, and if it is too large, the adhesive force will tend to decrease. Is described (see paragraph 33 of the publication).

(3) Japanese Patent Laid-Open No. 2001-49227 (Prior Art 3) For the purpose of imparting good storage stability and adhesive performance together,
A tackifier resin such as a rosin-based resin or a terpene-based resin, and an acrylic polymer, an olefin-based polymer, a rubber-based polymer similar to the base polymer used for the pressure-sensitive adhesive, and a glass at -70 ° C to 0 ° C. Transition temperature
A low Tg polymer having (Tg) is dissolved in a solvent together,
A method for producing an aqueous emulsion of a tackifier resin by adding an emulsifier separately is disclosed. In this case, Tg
It is described that when the temperature is 0 ° C or lower, the storage stability (skinning property) of the product is improved, and when the temperature is -70 ° C or higher, the decrease in heat resistance can be suppressed (see paragraph 23 of the publication). ).

On the other hand, various improvements have been made not only for the tackifier resin itself as in the above-mentioned prior arts 1 to 3, but also for the emulsifier for dispersing the resin in water. There are the following.

(4) Japanese Unexamined Patent Publication No. 61-14249 (Prior Art 4) In order to obtain a stable aqueous emulsion having a fine and uniform particle size and having a low foaming property, the styrene monomer content is 3%.
Disclosed is a tackifier resin emulsion in which an alkaline aqueous solution of a styrene / acrylic polymer having an acid value of 100 to 300 and a weight average molecular weight of 3000 to 30,000 at 0% by weight or more is used as an emulsifier.

(5) Japanese Patent Laid-Open No. 7-331208 (Prior Art 5) For the purpose of improving stability against mechanical shear,
A tackifier resin emulsion using a polymeric emulsifier composed mainly of a reactive emulsifier, styrenes and / or (meth) acrylic acid alkyl ester, and an anionic monomer is disclosed. The above-mentioned reactive emulsifier is a surfactant having a hydrophilic group and a hydrophobic group, has a C = C bond in the molecule, and has a specific functional group such as (meth) allyl group or 1-propenyl group. Examples include polyoxyethylene alkyl ether sulfosuccinate ester salts, polyoxyethylene alkyl ether sulfate ester salts, polyoxyethylene phenyl ether sulfosuccinate ester salts, polyoxyethylene phenyl ether sulfate ester salts, and the like. (See paragraph 13 of the publication), the anionic monomer,
(Meth) acrylic acid, maleic acid, styrene sulfonic acid,
Examples thereof include vinyl sulfonic acid (see paragraph 17 of the same publication).

(6) Japanese Patent Application Laid-Open No. 1-203031 (Prior Art 6) A copolymer obtained by reacting a hydrophobic monomer, a (meth) acrylic acid-based monomer, and a sulfonic acid group-containing monomer, or further , Maleic acid or a salt thereof, an aqueous rosin emulsion using a copolymer obtained by reacting a hydrophilic monomer such as (meth) acrylamide as an emulsifier is disclosed, and it is disclosed that the emulsion can be used as an adhesive or the like ( (Refer to the item of the effect of the invention in the same publication).

(7) Japanese Unexamined Patent Publication No. 2001-139919 (Prior Art 7) Polyoxyalkylene ethers for the purpose of improving storage stability and adhesive properties under normal conditions and eliminating concerns about environmental hormones. It is obtained by esterification of sulfosuccinic anhydride with sulfosuccinic anhydride, or by using a specific anionic emulsifier containing a sulfonated alkali metal sulfosuccinate after the esterification reaction of the above ethers with maleic anhydride. , Tackifier resin emulsions are disclosed.

[0011]

In the above-mentioned prior art 1 in which the type of tackifier resin constituting the aqueous emulsion is specified, the heat resistance is improved, but the tack is actually reduced. Further, in the above-mentioned conventional techniques 2 to 3 in which a polymer in which Tg is specified is introduced into a part of the constitution of the tackifier resin, the manufacturing process is complicated, and it is doubtful whether or not it is possible to impart an adhesive physical property commensurate with the production cost. For example, in the prior art 2, although the purpose is to achieve both the adhesive force and the holding force, the heat resistance is not sufficiently improved. In the prior art 3, the storage stability is improved to some extent, but the adhesive property is improved. Is not enough.

On the other hand, the prior arts 4 to 7 are devised as an emulsifier for dispersing the tackifier resin in water, the prior arts 4 to 6 are high molecular weight emulsifiers, and the prior art 7 are low molecular weight emulsifiers. However, although these related arts 4 to 7 can be expected to improve the mechanical stability and storage stability of the resulting aqueous emulsion, they are intended to improve various physical properties inherent in the tackifier resin regarding tackiness. Can not expect much. The technical object of the present invention is to improve the heat resistance of a tackifier resin emulsion without sacrificing the tackiness to satisfy both physical properties and to have good mechanical stability.

[0013]

In the above-mentioned prior arts 2 to 3, it is described that when the Tg of the tackifier resin changes, the adhesive properties such as adhesive strength and holding power are affected. Therefore, the present inventors have conducted intensive studies with reference to these conventional techniques, as a result, not a tackifier resin,
In consideration of limiting the type and physical properties of the emulsifier for dispersing the tackifier resin in water, selecting a polymeric emulsifier as the emulsifier, and of the physical properties of this polymeric emulsifier, not Tg It has been found that the adhesive property can be appropriately controlled by limiting the brittle temperature to a specific range. Specifically, when using a copolymer obtained by polymerizing various monomers, a polymer emulsifier obtained by saponifying a copolymer having a brittle temperature in a specific range of 110 to 150 ° C. It is possible to obtain a tackifier resin emulsion that simultaneously satisfies the contradictory physical properties of heat resistance, and further, in addition to the above-mentioned polymer emulsifier, a low-molecular emulsifier, particularly a low-molecular weight emulsifier such as an organic sulfonate or a sulfate ester salt. The present invention has been completed by finding out that the combined use of a molecular emulsifier effectively increases the emulsifying power when producing a tackifier resin emulsion.

That is, the present invention 1 is a tackifier resin emulsion in which a tackifier resin is dispersed in water using an emulsifier, wherein the emulsifier saponifies a copolymer having an embrittlement temperature of 110 to 150 ° C. It is a tackifier resin emulsion characterized by being a polymer emulsifier.

A second aspect of the present invention is the tackifier resin emulsion according to the first aspect, wherein the tackifier resin is a rosin resin, a terpene resin, a petroleum resin, or the like.

A third aspect of the present invention is the tackifier resin emulsion according to the first aspect, wherein the tackifier resin is a rosin resin having a softening point of less than 150 ° C.

In a fourth aspect of the present invention, in any one of the first to third aspects, the polymer emulsifier comprises (A) a hydrophobic monomer and (B)
The tackifier resin emulsion is a saponified product of a copolymer obtained by reacting a polymerizable unsaturated organic acid.

In a fifth aspect of the present invention, in any one of the first to fourth aspects of the invention, the tackifier resin is dispersed in water by using a mixture of a high molecular weight emulsifier and a low molecular weight emulsifier instead of the high molecular weight emulsifier. It is a characteristic tackifier resin emulsion.

A sixth aspect of the present invention is the tackifier resin emulsion according to the fifth aspect, wherein the low molecular weight emulsifier is an organic sulfonate or an organic sulfate ester salt.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is, firstly, a tackifier resin emulsion emulsified and dispersed using a polymeric emulsifier having a specific embrittlement temperature, and secondly, in addition to the above-mentioned polymeric emulsifier. It is a tackifier resin emulsion that is emulsified and dispersed together with a low molecular weight emulsifier. In the present invention, by designing the embrittlement temperature of the polymer emulsifier in a specific range, it is possible to produce a viscous / adhesive having good heat resistance even if a tackifier resin having a softening point not so high is used.

Examples of the tackifier resin include rosin-based resins, terpene-based resins, petroleum-based resins, dammar, copal, shellac, alkylphenol resins, and xylene resins. Of these, rosin-based resins are preferred.
In particular, as shown in the present invention 3, a rosin resin having a softening point of less than 150 ° C. is preferable. The rosin-based resin can be used alone or in combination with rosins and rosin derivatives. The rosins are tall rosin, gum rosin and wood rosin,
Further, it is a concept including disproportionated rosin, polymerized rosin, hydrogenated rosin, other chemically modified rosin, or purified products thereof.

As the rosin derivative, carboxylic acid groups of rosin esters, unsaturated carboxylic acid-modified rosins, unsaturated carboxylic acid-modified rosin esters, or rosins modified with rosins or unsaturated carboxylic acids are reduced. Examples include treated rosin alcohols. The rosin ester refers to a product obtained by producing the rosin and the polyhydric alcohol by a known esterification method. As conditions for the esterification reaction, the charging ratio of the rosin and the polyhydric alcohol is COOH / OH = 1 / (0.2-2.0.2 in terms of the hydroxyl group equivalent ratio of the alcohol to the carboxyl group equivalent of the rosin.
0), the reaction temperature is about 150 to 300 ° C., and the reaction time is about 2 to 30 hours. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, neopentyl glycol, trimethylene glycol, tetramethylene glycol, dihydric alcohols such as 1,3-butanediol and 1,6-hexanediol, glycerin and trimethylolpropane, Trihydric alcohols such as trimethylolethane and triethylolethane, tetrahydric alcohols such as pentaerythritol and diglycerin,
Hexahydric alcohol such as dipentaerythritol, or
Examples thereof include amino alcohols such as triethanolamine, tripropanolamine, triisopropanolamine, N-isobutyldiethanolamine and N-normal butyldiethanolamine.

The unsaturated carboxylic acid-modified rosins are those obtained by reacting the rosins with α, β-unsaturated carboxylic acids by a known method. In this case, the reaction temperature is 1
The reaction temperature time is about 50 to 300 ° C. and the time is about 1 to 24 hours. The charging amount of the α, β-unsaturated carboxylic acids is about 20 parts by weight or less of the α, β-unsaturated carboxylic acids with respect to 100 parts by weight of the rosins. Examples of the α, β-unsaturated carboxylic acids include fumaric acid, (anhydrous) maleic acid, itaconic acid, (anhydrous) citraconic acid, acrylic acid and methacrylic acid.

The unsaturated carboxylic acid-modified rosin ester can be obtained by reacting the rosin with a polyhydric alcohol and an α, β-unsaturated carboxylic acid either sequentially or simultaneously. Esterification reaction with polyhydric alcohol, α,
The strengthening reaction with β-unsaturated carboxylic acids is as described above. In addition, when α, β-unsaturated carboxylic acids are reacted after the esterification reaction of rosins at a high temperature, rosins having a levopimal skeleton are reduced and isomerized to dehydroabietic acid skeleton, and the reaction proceeds. Be careful as it may be difficult to do.

Examples of the terpene-based resin include polymers of α-pinene and β-pinene, phenolic or aromatic modified products thereof, hydrogenated modified products, and hydrocarbon modified products thereof. As the petroleum resin, aliphatic (C ₅₎ resins, aromatic (C ₉₎ resin, copolymerized (C ₅ / C ₉₎ resins, coumarone resins and coumarone - indene resins, dicyclopentadiene-based petroleum Examples thereof include resins, hydrogenated petroleum resins, and pure monomer petroleum resins such as styrene.

The polymeric emulsifier of the present invention is a saponified product of a copolymer having a specific embrittlement temperature, and the embrittlement temperature of the copolymer before saponification is 110 to 150 ° C., preferably 120 to 1
40 ° C. If the embrittlement temperature is lower than 110 ° C, the heat resistance of the final product viscous / adhesive will be reduced, and if it is higher than 150 ° C, the monomers that can be used will be restricted, making molecular design of the copolymer difficult. And, in practice, the embrittlement temperature is 1
Even if it exceeds 50 ° C, it does not contribute much to further improvement of heat resistance.

The above-mentioned polymeric emulsifier may be one obtained by saponifying a copolymer having an arbitrary monomer composition whose brittleness temperature can be designed within the above-mentioned specific range. Specifically, the present invention 4
As shown in, a saponified product of a copolymer having a hydrophobic monomer (A) and a polymerizable unsaturated organic acid (B) as constituent monomers can be mentioned. The hydrophobic monomer (A) includes styrenes and (meth)
Acrylic acid esters can be used alone or in combination. Examples of styrenes include styrene, styrene derivatives having a substituent on the vinyl group such as α-methylstyrene, and styrene derivatives having a substituent on the benzene ring such as vinyltoluene and p-chlorostyrene. However, styrene, α-methylstyrene and the like are preferable from the viewpoint of the affinity between the polymer emulsifier and the tackifier resin. the above
Examples of (meth) acrylic acid esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, and methacrylic acid. Methacrylic acid esters such as benzyl acid ester, ethyl acrylate,
Propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, acrylic acid-2
Examples thereof include acrylic acid esters such as ethylhexyl, cyclohexyl acrylate, and benzyl acrylate, and methyl methacrylate and isobutyl methacrylate are preferable from the viewpoint of affinity between the polymer emulsifier and the tackifier resin.

As the polymerizable unsaturated organic acid (B), a polymerizable unsaturated carboxylic acid or a polymerizable unsaturated sulfonic acid can be used alone or in combination. The unsaturated carboxylic acids are unsaturated monomers having at least one carboxyl group in the molecule, and specifically, acrylic acid, methacrylic acid,
Crotonic acid, (anhydrous) maleic acid, fumaric acid, itaconic acid, (anhydrous) citraconic acid, or their sodium salts,
Alkali metal salts such as potassium salts, alkaline earth metal salts, ammonium salts, or organic bases, and the like,
Methacrylic acid and (anhydrous) maleic acid are preferable from the viewpoint of the affinity between the polymer emulsifier and the tackifier resin. Also,
The unsaturated sulfonic acids are unsaturated monomers having at least one sulfonic acid group in the molecule, and specifically, isoprene sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, 2- (meth) ) Acrylamide-
2-Methylpropanesulfonic acid, sulfopropyl (meth) acrylate, or their alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts, ammonium salts, organic bases, etc. From the viewpoint of the affinity between the emulsifier and the tackifier resin or the cost, isoprenesulfonic acid or its alkali metal salt is preferred. By the way, from the standpoint of promoting solubility in water and improving the coating function of the polymeric emulsifier on the tackifier resin, the polymerizable unsaturated organic acids include unsaturated sulfonic acids rather than unsaturated carboxylic acids. It is better to give priority to. Therefore, as shown in the present invention 6, it is preferable to use unsaturated sulfonic acids alone or to use unsaturated sulfonic acids and unsaturated carboxylic acids in combination as the polymerizable unsaturated organic acids.

The copolymer constituting the high molecular weight emulsifier of the present invention can be obtained by a conventional method such as emulsion polymerization, solution polymerization, suspension polymerization or bulk polymerization of a mixture of the above-mentioned constituent monomers in the presence of a polymerization initiator. And is preferably produced by known aqueous emulsion polymerization or solution polymerization. In the emulsion polymerization, basically, various monomer components are mixed and added all at once to an aqueous system mixed with an emulsifier, or gradually added. As the emulsifier, a known anionic, nonionic or amphoteric surfactant or the like can be used. Examples of the anionic surfactant include alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, fatty acid salts, rosinates, alkyl sulfates, alkyl sulfosuccinates, α-olefin sulfonates, alkylnaphthalene sulfonates, Examples thereof include polyoxyethylene alkyl (aryl) sulfate ester salts. Examples of the nonionic surfactant include C _{1 to} C ₂₀ alkanols, phenols, naphthols, bisphenols, C _{1 to} C ₂₀ alkylnaphthols, polyoxyethylene (propylene) glycols, ethylene oxides such as aliphatic amines, and / or propylene. Examples thereof include oxide adducts. Examples of the amphoteric surfactant include carboxybetaine-type, sulfobetaine-type, aminocarboxylic acid-type, and imidazoline-derivative type surfactants.

Examples of the above-mentioned polymerization initiator include persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate, and 2,2-azobis-N-2-carboxyethyl-2-methylpropionamidine hydrate. Examples thereof include water-soluble azo compounds and oil-soluble initiators such as benzoyl peroxide. It goes without saying that a chain transfer agent can be used for the purpose of adjusting the molecular weight in the emulsion polymerization. Examples of the chain transfer agent include n-dodecyl mercaptan, n-octyl mercaptan, mercaptoethanol, thioglycolic acid and its salts, mercaptans such as thioglycolic acid ester such as butyl thioglycolate, isopropyl alcohol, carbon tetrachloride, cumene. Etc. can be used alone or in combination.

The copolymer, which has undergone the above-mentioned polymerization reaction, is neutralized with an alkali such as sodium hydroxide, potassium hydroxide, ammonia, a lower amine, or an alkanolamine to partially or completely saponify the copolymer ( That is, it is prepared as a copolymer salt aqueous solution) and provided as the polymer emulsifier of the present invention. However, by using the constituent monomers of the copolymer in the form of salt such as carboxylate or sulfonate, the aqueous solution of the copolymer obtained is already in a saponified state without addition of alkali. In this case, it is not necessary to separately saponify with alkali as described above. Specific examples of the copolymer constituting the polymer emulsifier of the present invention include styrene as a hydrophobic monomer, α-methylstyrene, maleic acid, methacrylic acid, isoprenesulfonic acid, and styrenesulfone as polymerizable unsaturated organic acids. A copolymer obtained by polymerizing sodium salts of an acid as a constituent monomer, respectively, or a part of a hydrophobic monomer based on these constituent monomers, such as isobutyl methacrylate and methyl methacrylate. Copolymers which are substituted or added to the (meth) acrylic acid esters are preferred.

The low molecular weight emulsifier is used together with the high molecular weight emulsifier and is used for the purpose of improving the emulsifying power of the tackifier resin emulsion. As the low molecular weight emulsifier, ordinary anionic emulsifiers and nonionic emulsifiers can be used alone or in combination. Besides, as described above, the same surfactants used for the production of high molecular emulsifiers are also effective. Examples of the anionic emulsifiers include organic sulfonates and sulfate ester salts, and specifically, the following (1) to (6). (1) Alkylaryl sulfonates such as sodium dodecylbenzene sulfonate. (2) Alkyl (or alkenyl) sulfate ester salts such as sodium lauryl sulfate and sodium oleyl sulfate. (3) Polyoxyethylene alkyl (or alkenyl) such as sodium polyoxyethylene lauryl ether sulfate and sodium polyoxyethylene oleyl ether sulfate
Ether sulfate ester salts. (4) Polyoxyethylene alkylaryl ether sulfate ester salts such as sodium polyoxyethylene nonylphenyl ether sulfate. (5) Alkylsulfosuccinate ester salts such as sodium monooctylsulfosuccinate, sodium dioctylsulfosuccinate, and disodium polyoxyethylenelaurylsulfosuccinate, and derivatives thereof. (6) Alkyl diaryl ether disulfonates such as sodium alkyl diphenyl ether disulfonate and derivatives thereof.

Examples of the above nonionic emulsifiers include the following. Polyoxyethylene alkyl (or alkenyl) ethers such as polyoxyethylene lauryl ether and polyoxyethylene oleyl ether. Polyoxyethylene alkylphenyl ethers such as polyoxyethylene nonylphenyl ether. Sorbitan higher fatty acid esters such as sorbitan monolaurate and sorbitan trioleate. Polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate. Polyoxyethylene higher fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monooleate. Glycerin higher fatty acid esters such as oleic acid monoglyceride and stearic acid monoglyceride. Polyoxyethylene / polyoxypropylene / block copolymer.

The low molecular weight emulsifier is preferably an anionic emulsifier such as an organic sulfonate or a sulfate ester salt as shown in the present invention 8. Specifically, specifically, the polyoxyethylene alkyl (or alkenyl) of the above (3) is used. ) Ether sulfate ester salts and the like are preferable. In addition, the applicant of the present invention is Japanese Patent Laid-Open No.
In JP-A 0-81247, when a polyoxyethylene alkyl ether sulfosuccinate ester salt is used as an emulsifier when producing an aqueous emulsion using a rosin ester as a tackifier resin, the emulsion is finely divided and excellent in stability. Since it discloses that the adhesive performance of the adhesive can be improved, the polyoxyethylene alkyl ether sulfosuccinic acid ester salt (5) to which the polyoxyethylene alkyl ether sulfosuccinic acid ester salt and its derivatives also belong,
It is useful as a low molecular weight emulsifier of the present invention.

The tackifier resin emulsion of the present invention is produced by a solvent type emulsification method, a solventless emulsification method, a phase inversion emulsification method, or any other conventional method. The solvent-type emulsification method, various tackifier resins are dissolved in an organic solvent such as methylene chloride and toluene, and after preliminarily mixing an emulsifier and water to prepare an aqueous emulsion of coarse particles, various mixers, a high-pressure emulsifier, This is a method in which the above organic solvent is removed after fine emulsification using a high pressure discharge type emulsifying machine, a high shear type emulsifying disperser or the like. The above solventless emulsification method is a method in which various molten tackifier resins and emulsifiers are premixed to prepare an aqueous emulsion of coarse particles, and then fine emulsification is similarly performed using various emulsification dispersers. Further, the phase inversion emulsification method, after sufficiently kneading the tackifier resin, a polymeric emulsifier consisting of a saponified product of the copolymer (copolymer salt aqueous solution), or further the low molecular weight emulsifier, This is a method in which water is gradually added with stirring to invert the phase of the water-in-oil emulsion to the oil-in-water emulsion.

When the above tackifier resin emulsion is produced, the addition ratio of the polymeric emulsifier is 0.5 to 10 parts by weight, preferably 2 to 10 parts by weight based on 100 parts by weight of the tackifier resin. 6 parts by weight. When a high molecular weight emulsifier and a low molecular weight emulsifier are used in combination, it is preferable to adjust the total so as to be the above addition ratio.

[0037]

When the tackifier resin is dispersed in water using the polymer emulsifier of the present invention, the polymer emulsifier coats the surface of the fine particles of the tackifier resin, and the embrittlement temperature of the tackifier resin itself increases. Even when it is low, it is estimated that the tackifier resin emulsion can have excellent heat resistance because the apparent embrittlement temperature of the tackifier resin fine particles is increased. Also, regarding tacky physical properties such as tack,
Since the physical properties originally possessed by the tackifier resin are obtained, both physical properties of heat resistance and tackiness, which are contradictory properties in the prior art, can be achieved at the same time. On the other hand, the tackifier resin emulsion dispersed in water using the polymer emulsifier of the present invention forms a fine emulsification system and shows good mechanical stability, but it is a low molecular emulsifier in addition to the polymer emulsifier. When used together, the emulsifying power at the time of emulsion production is enhanced, and a finer particle-based emulsion can be formed.
It is presumed that this is because the low-molecular weight emulsifier is further adsorbed on the surface of the fine particles of the tackifier resin whose surface is protected by the high-molecular weight emulsifier to prevent the aggregation and sedimentation of the emulsion.

[0038]

As the emulsifier for dispersing the tackifier resin emulsion in water, a polymer emulsifier obtained by saponifying a copolymer having a specific embrittlement temperature is used. The heat resistance can be effectively improved without sacrificing the adhesiveness, and thus both can be satisfactorily achieved. In particular, even if a rosin resin whose softening point is not so high is used as the tackifier resin, there is an advantage that the heat resistance can be secured. Further, the tackifier resin emulsion emulsified using the polymer emulsifier of the present invention is also excellent in mechanical stability, and in particular, when used in combination with a low molecular weight emulsifier, the emulsifying power at the time of emulsion production is enhanced. It is possible to obtain a fine emulsion equivalent to or more than that of the tackifier resin emulsion, and it is possible to further improve the mechanical stability of the emulsion.

[0039]

[Examples] Production examples of various rosin-based resins, synthesis examples of polymer emulsifiers, production examples of tackifier resin emulsions in which rosin-based resins are dispersed in water using polymer emulsifiers, the tackifier resins A property test example of an emulsion, a production example of an aqueous adhesive using the emulsion, and an adhesive performance evaluation test example of the aqueous adhesive will be sequentially described. In addition, "parts" and "%" in the following examples and test examples are based on weight unless otherwise specified. The present invention is not limited to the following examples and test examples, and it goes without saying that any modification can be made within the scope of the technical idea of the present invention.

<< Production Example of Rosin Resin >> (1) Production Example 1 (Production Example of Polymerized Rosin Ester with Softening Point 140 ° C.) Polymerized rosin was added to a reaction apparatus equipped with a stirrer, a cooler, a thermometer and a nitrogen inlet tube. After charging 100 parts and 11 parts of glycerin (abbreviated as GLY in FIG. 1 described later), the system was gradually heated under a nitrogen gas stream until the temperature of the system reached 270 ° C., and reacted at the same temperature for 4 hours. Then, the low boiling point component was removed to obtain a glycerin ester of polymerized rosin. The polymerized rosin ester had a softening point of 140 ° C., an acid value of 14, and a Gardner color number of 10.

(2) Production Example 2 (Production Example of Polymerized Rosin Ester with Softening Point of 160 ° C.) This Production Example 2 is an example of production of a high softening point resin similar to the rosin resin disclosed in Prior Art 1. . That is, a stirring device,
100 parts of polymerized rosin, pentaerythritol (PE in FIG. 1 was placed in a reactor equipped with a cooler, a thermometer and a nitrogen inlet tube.
After a 10-part charge, the system was gradually heated under a nitrogen gas stream until the temperature of the system reached 280 ° C., and the reaction was carried out at the same temperature for 8 hours. Then, the low boiling point component was removed to obtain a pentaerythritol ester of polymerized rosin. The polymerized rosin ester had a softening point of 160 ° C., an acid value of 17, and a Gardner color number of 12.

(3) Production Example 3 (Example of production of rosin ester having a softening point of 100 ° C.) 100 parts of gum rosin and 12 parts of pentaerythritol were placed in a reactor equipped with a stirrer, a cooler, a thermometer and a nitrogen introducing tube.
After charging the parts, the system was gradually heated under a nitrogen gas stream until the temperature of the system reached 280 ° C., and the reaction was carried out at the same temperature for 8 hours. Then, the low boiling point component was removed to obtain a pentaerythritol ester of rosin. The softening point of the rosin ester is 1
At 00 ° C., the acid value was 18, and the Gardner color number was 11.

<< Synthesis Example of Polymer Emulsifier >> In the following synthesis examples, Synthesis Example 1 is an example in which a copolymer having an embrittlement temperature of 120 ° C. is saponified, and Synthesis Example 2 has an embrittlement temperature of 140 ° C. The example in which the copolymer is saponified and Comparative Synthesis Example 1 are 100 ° C.
An example of saponifying a copolymer having a brittleness temperature of Comparative Example 2 is styrene prepared according to the above-mentioned Prior Art 2.
This is an example of saponification of an acrylic polymer.

(1) Synthesis Example 1 A reactor equipped with a stirrer, a cooler, a thermometer and a nitrogen inlet tube was charged with 51.45 parts of water and 0.84 part of maleic anhydride.
0.98 parts of isoprene sulfonic acid, 1.95 parts of sodium alkylbenzene sulfonate (solid content 63%), and 0.49 parts of polyoxyethylene nonylphenyl ether were charged to prepare a homogeneous aqueous solution. The temperature of the aqueous solution was raised to 84 ° C., and 4.96 parts of methacrylic acid and 0.42 part of isobutyl methacrylate, 2.38 parts of α-methylstyrene, 4.49 parts of styrene, and 0.28 parts of n-dodecyl mercaptan were added thereto. Was added, and further 3.91 parts of water was added. Then, at 74 ° C, 1.95 parts of water and sodium bisulfite of 0.
Polymerization was started by adding 3 parts by weight of an aqueous solution. The temperature was raised to 98 ° C. in about 40 minutes, kept at 95 ° C. for 1.5 hours, and then cooled to 78 ° C. Then 10.25 parts of water and 4
The resin was saponified by adding 5.68 parts of 8% sodium hydroxide aqueous solution, the reaction was terminated by stirring at 85 ° C for 1 hour, and after cooling, 9.67 parts of water was added to give a solid content of 19%.
A high molecular weight emulsifier was obtained. The embrittlement temperature of the resin was 120 ° C. before saponification.

The measurement of the embrittlement temperature is as follows.
In addition, in the case of Synthesis Example 2 and Comparative Synthesis Examples 1 and 2 described later, the same measurement was performed. That is, as shown in FIG. 2, a metal rod is placed vertically in a cylindrical container having a diameter of 5 mm and a depth of 5 mm, the resin of Synthesis Example 1 is poured around the metal rod, and water is evaporated to remove the metal rod. A measurement sample was prepared by fixing.
While applying a tension of 300 mN to the metal rod of this sample,
The temperature was raised from 30 ° C. to 350 ° C. at a rate of 5 ° C./min, and the embrittlement temperature was measured. The measuring device is DMS6100
(Manufactured by Seiko Instruments Inc.) was used.

(2) Synthetic Example 2 Based on the above Synthetic Example 1, among the monomers used in Synthetic Example 1, isobutyl methacrylate was not used, and α
-Methylstyrene was changed to 5.2 parts and styrene was changed to 2.09 parts, and the other conditions were set as in Synthesis Example 1 to obtain a polymer emulsifier having a solid content of 19%. The embrittlement temperature of the resin before saponification was 140 ° C.

(3) Comparative Synthesis Example 1 Based on the above Synthesis Example 1, 3.92 parts of isobutyl methacrylate among the monomers used in Synthesis Example 1,
α-Methylstyrene was changed to 0.88 parts and styrene was changed to 2.49 parts, and otherwise the same setting as in Synthesis Example 1 was carried out to obtain a polymer emulsifier having a solid content of 19%. The embrittlement temperature of the resin before saponification was 100 ° C.

(4) Comparative Synthesis Example 2 As described above, a styrene-acrylic polymer emulsifier was produced in accordance with Example 1 of the prior art 2 mentioned above.
That is, based on the above Synthesis Example 1, the monomer composition used in Synthesis Example 1 was changed to 14 parts of styrene and 6 parts of methacrylic acid.
Part (at that time, sodium alkylbenzene sulfonate as an emulsifier and polyoxyethylene nonylphenyl ether were also charged at the same time as the monomer), and also 48%
Saponification was performed by changing 5.68 parts of aqueous sodium hydroxide solution to 5.68 parts of 20% aqueous ammonia, and otherwise, Synthesis Example 1
Under the same conditions as described above, a polymer emulsifier having a solid content of 22% was obtained. The embrittlement temperature of the resin before saponification was 100 ° C.

<< Example of Tackifier Resin Emulsion >>
Therefore, using the rosin-based resins of Production Examples 1 to 3 as tackifier resins, the above Synthesis Examples 1 and 2 and Comparative Synthesis Examples 1 and 2 are used.
Each polymer emulsifier of Example 1 was used to disperse in water, and Example 1 was used.
~ 6 and each tackifier resin emulsion of Comparative Examples 1 to 4 were produced. Among Examples 1 to 6 below, Example 1 uses a high molecular emulsifier obtained by saponifying a copolymer having an embrittlement temperature of 120 ° C. and an anionic low molecular emulsifier, and has a softening point of 14
An example in which a polymerized rosin ester at 0 ° C. is dispersed in water, Example 2 is based on the same Example 1, but a rosin resin has a softening point of 1
An example of substituting a rosin ester at 00 ° C., Example 3 is also based on Example 1, and a polymeric emulsifier is used at a brittle temperature of
An example of substituting a saponified product of a copolymer at 0 ° C., Example 4 is basically the same as Example 1, and an example of substituting a low-molecular emulsifier with a nonionic emulsifier, and Example 5 is similarly based on Example 1. As an example in which only a high molecular emulsifier is used alone without using a low molecular weight emulsifier, Example 6 is an example in which the rosin-based resin is replaced with a polymerized rosin ester having a softening point of 160 ° C. based on Example 1 as well. is there.

Among Comparative Examples 1 to 4, Comparative Example 1 uses only an anionic low molecular weight emulsifier and has a softening point of 1
An example in which a polymerized rosin ester at 40 ° C. is dispersed in water, Comparative Example 2 is based on Comparative Example 1, and the rosin-based resin is replaced with a polymerized rosin ester having the same high softening point (160 ° C.) as in the above-mentioned Prior Art 1. Similarly, the comparative example 3 or 4 is based on the comparative example 1, and a polymeric emulsifier obtained by saponifying a copolymer having an embrittlement temperature of 100 ° C. (Comparative Synthesis Example 1 or 2) is used in combination with a low molecular weight emulsifier. And a polymerized rosin ester having a softening point of 140 ° C. is dispersed in water.

Example 1 100 parts of the polymerized rosin ester (softening point 140 ° C.) of the above Production Example 1 was dissolved in 56 parts of toluene to prepare a toluene solution of the polymerized rosin ester. Next, the polymer emulsifier of Synthesis Example 1 (brittle temperature 12
2 parts in terms of solid content, and 2 parts of polyoxyethylene oleyl ether sulfuric acid ester sodium salt (Hitenol 073; manufactured by Daiichi Kogyo Seiyaku Co., Ltd., abbreviated as emulsifier 1 in FIG. 1) in terms of solid content. The emulsifier aqueous solution was prepared by dissolving it in 118 parts of water, and the emulsifier aqueous solution was added to the previously prepared toluene solution and stirred to carry out preliminary emulsification. The obtained preliminary emulsion was emulsified by high-pressure emulsification at a pressure of 300 kg / cm ² with a high-pressure emulsifier manufactured by Manton Gaulin. This emulsion is 110mmHg
Toluene is removed by vacuum distillation under the conditions of
% Tackifier resin emulsion was obtained.

Example 2 Based on Example 1 above,
The tackifier resin was prepared from the rosin ester of Production Example 3 (softening point 1
(00 ° C.) and other conditions were set as in Example 1 to obtain a tackifier resin emulsion having a solid content of 55%.

<< Embodiment 3 >> Based on Embodiment 1 above,
Polymeric emulsifiers of Synthesis Examples 1 to 2 (brittle temperature 140
C.) and other conditions were set as in Example 1 to obtain a tackifier resin emulsion having a solid content of 55%.

<Embodiment 4> Based on the above Embodiment 1,
From low molecular weight emulsifiers to anionic polyoxyethylene oleyl ether (Neugen ET-12)
9; manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., abbreviated as emulsifier 2 in FIG. 1) and other conditions were set as in Example 1 to obtain a tackifier resin emulsion having a solid content of 55%.

Example 5 Based on the above Example 1,
Without using the low molecular weight emulsifier, 4 parts of the high molecular emulsifier of Synthesis Example 1 was used alone in terms of solid content, and other conditions were the same as in Example 1.
By the same setting as above, a tackifier resin emulsion having a solid content of 55% was obtained.

<< Sixth Embodiment >> Based on the above first embodiment,
The tackifier resin was replaced with the polymerized rosin ester of Production Example 2 (softening point of 160 ° C.), and the other conditions were set as in Example 1 to obtain a tackifier resin emulsion having a solid content of 55%. .

Comparative Example 1 Based on the above Example 1,
Without using a high molecular weight emulsifier, only 4 parts of the low molecular weight emulsifier used in Example 1 was used in terms of solid content, and other conditions were set in the same manner as in Example 1 to give a tackiness of 55% solid content. A resin emulsion was obtained.

Comparative Example 2 Based on Example 6 above,
Without using a high molecular weight emulsifier, only 4 parts of the low molecular weight emulsifier used in Example 6 was used in terms of solid content, and other conditions were set in the same manner as in Example 6 to impart tackiness of 55% solid content. A resin emulsion was obtained.

Comparative Example 3 Based on the above Example 1,
When the high molecular emulsifier and the low molecular emulsifier are used in combination, the high molecular emulsifier is replaced with the high molecular emulsifier of Synthesis Example 1 to Comparative Synthetic Example 1 (embrittlement temperature 100 ° C.), and other conditions are the same as in Example 1. To obtain a tackifier resin emulsion having a solid content of 55%.

Comparative Example 4 Based on the above Example 1,
When the high molecular weight emulsifier and the low molecular weight emulsifier of Synthesis Example 1 are used in combination, the high molecular weight emulsifier is replaced with the high molecular weight emulsifier of Synthesis Example 1 (Comparative Synthesis Example 2) (embrittlement temperature 100 ° C.) and other conditions Setting the same as in Example 1, a tackifier resin emulsion having a solid content of 55% was obtained.

<< Testing Properties of Tackifier Resin Emulsion >> The average particle size of each tackifier resin emulsion obtained in Examples 1 to 6 and Comparative Examples 1 to 4 was measured by the following measurement tests. The diameter (μm), the generation rate (%) of the resin precipitated by centrifugal precipitation, and the generation rate (%) of the aggregate by the Malone test were measured to evaluate the degree of fineness and mechanical stability of the tackifier resin emulsion.

(1) Test of measurement of average particle size Using a measuring device (LA-920; manufactured by Horiba Ltd.), the transmittance of the tungsten lamp (that is, the transmittance (H) in the measuring device) is 80 to 85%. So that the tackifier resin emulsion is diluted with distilled water, and the relative refractive index is measured under the conditions of 1.2, and the result is computer-processed to obtain the arithmetic mean diameter of the emulsion. The average particle diameter was used.

(2) Centrifugal Sedimentation Measurement Test After adjusting the tackifier resin emulsion to a solid content of 50%, centrifugal force 2980G (G is gravitational acceleration) using a centrifuge (RM-180 rotor; manufactured by Kokusan Co., Ltd.). The upper layer liquid was removed by decantation, the centrifuge tube was washed with distilled water, dried, and the weight of the solid resin in the sedimentation part was measured, and the degree of sedimentation was calculated by the following formula. . Occurrence rate of sediment (%) = (sedimented solid content / initial solid content) x
100

(3) Mechanical stability test After adjusting the tackifier resin emulsion to a solid content of 50%, a Marlon test was carried out under the conditions of a load of 10 kg, a rotation speed of 1000 rpm, and a share time of 5 minutes to measure the weight of aggregates. Then, the generation rate of aggregates was calculated by the following formula. Aggregate generation rate (%) = (aggregate / initial solid content) x 100

Columns 5 to 3 from the right in FIG. 1 summarize the test results. First, looking at the column of average particle size in FIG. 1, it was found that Examples 1 to 6 had a smaller average particle size than Comparative Examples 1 to 4, and the particles were finer. Generally, the quality of the emulsifying power at the time of producing an emulsion can be judged by the size of the average particle diameter of the obtained emulsion, and therefore the polymer emulsifier of the present invention is a normal low-molecular emulsifier (Comparative Examples 1 and 2) or It was revealed that the emulsifying power at the time of production of the tackifier resin emulsion can be enhanced as compared with the polymeric emulsifiers having an embrittlement temperature lower than the specific range of the present invention (Comparative Examples 3 to 4). . When the relative evaluation between Examples 1 to 6 is performed in more detail, the polymer emulsifier and the nonionic low-molecular emulsifier (the emulsifier described above are more than the average particle size of Example 5 in which only the polymer emulsifier of the present invention is used alone). The average particle size of Example 4 in which 2) is used in combination is further finer, and the polymer emulsifier and the anionic low molecular weight emulsifier (the above-mentioned emulsifier 1; Since the average particle size of Examples 1 to 3 in which a salt-based anionic low-molecular emulsifier is used in combination is further fine, a low-molecular emulsifier is used in addition to the high-molecular emulsifier,
Especially, it was found that the combined use of the anionic low molecular weight emulsifier improves the emulsifying power during the production of the emulsion and contributes to the miniaturization of the emulsion.

On the other hand, with respect to the respective occurrence rates of the centrifugal sediment and the aggregate (Marlon test) in FIG.
Markedly improved from Comparative Examples 1 to 4. That is, in Comparative Examples 3 to 4 in which a high molecular emulsifier having a brittle temperature lower than that of the present invention is used, Comparative Examples 1 to 2 in which only a low molecular emulsifier is used.
As a result, the respective occurrence rates of the centrifugal sediment and the agglomerate were improved, but in Examples 1 to 6 in which the polymer emulsifier of the present invention was used, the occurrence rates were further improved as compared with the above Comparative Examples 3 to 4. Therefore, taking the results shown in FIG. 1 together, when the polymer emulsifier of the present invention is used in the production of the tackifier resin emulsion, the emulsifying power is increased and the emulsion can be finely satisfactorily satisfactorily sewn. Since it is possible to improve the stability and storage stability, it is clear that specifying the embrittlement temperature of the copolymer that constitutes the polymer emulsifier greatly contributes to the miniaturization and stabilization of the tackifier resin emulsion. Became. In this case, if a low molecular weight emulsifier is used in combination with the polymeric emulsifier of the present invention, the emulsifying power is further enhanced and the emulsion can be further refined.
It has been found that anionic low molecular weight emulsifiers based on sulfate or organic sulfonate are preferable as the low molecular weight emulsifier.

<< Production Example of Aqueous Emulsion Acrylic Adhesive >> Then, the tackifier resin emulsions of Examples 1 to 6 and Comparative Examples 1 to 4 were added to an acrylic polymer emulsion as a base polymer. Thus, an aqueous emulsion adhesive was prepared, and an adhesive performance evaluation test of tackiness and heat resistance of this aqueous emulsion adhesive was conducted as described later. First, the method for producing the acrylic polymer is as follows. That is, 60.0 parts of ion-exchanged water and 0.1 part of a reducing agent (sodium bisulfite) were dissolved in a reactor equipped with a stirrer, a cooler, a thermometer and a nitrogen inlet tube under a nitrogen gas stream. Aqueous solution (a) was used. Further, 1.5 parts of polyethylene glycol nonyl phenyl ether and 1.5 parts of polyethylene glycol oleyl ether ammonium sulfonate were dissolved in 34.5 parts of ion-exchanged water, and 97.0 parts of 2-ethylhexyl acrylate and 3 parts of methacrylic acid were dissolved therein. 0.0 parts and catalyst (ammonium persulfate) 0.5
Parts were added and pre-emulsified with a homomixer to obtain a dispersion liquid (b). The above aqueous solution (a) is kept at 82 ° C.
(b) was polymerized dropwise over 4 hours. After the entire amount of the dispersion liquid (b) had been added dropwise, the reaction was carried out at 82 ° C for 1 hour, and 2.0 parts of deionized water was added to a reducing agent (sodium bisulfite) of 0.1
Parts and 0.1 parts of catalyst (ammonium persulfate) dissolved were added. Complete the reaction for an additional 1 hour, and after cooling 1
Filtration with a 50 mesh wire net gives a solid content of 49.5%.
Acrylic polymer emulsion of was obtained. Then, to 100 parts of the acrylic polymer emulsion (solid content conversion), 15 parts (solid content conversion) of each tackifier resin emulsion of Examples 1 to 6 and Comparative Examples 1 to 4 was added. , An aqueous emulsion type acrylic adhesive was produced.

<< Adhesive Performance Evaluation Test Example of Aqueous Emulsion Adhesive >> Then, an aqueous adhesive using the tackifier resin emulsion of each of Examples 1 to 6 and Comparative Examples 1 to 4 was prepared.
The thickness is 25 μm so that the thickness of the coating film after drying is 30 μm.
Was coated on the PET film of Example 1 and dried at 105 ° C. for 3 minutes to prepare a pressure-sensitive adhesive sheet, which was subjected to the following various performance evaluation tests.

(1) Tack By the J. Dow method described in JIS-Z0237,
1/32 (steel ball No. 1) to 32/3 on the adhesive sheet
Rolling a 2 (steel ball No. 32) inch steel ball, the maximum steel ball number that stops on the sheet is the inclination of 30 degrees and the temperature of 23 ° C.
It was measured under the conditions. Therefore, in the test, it can be determined that the higher the steel ball number, the better the tack performance.

(2) Heat resistance The heat resistance test was carried out by using the deviation of the cohesive force test as a criterion. That is, based on JIS-Z0237, a stainless steel plate (SUS304 polished with 280-plate abrasive paper for surface processing) is used as an adherend, and 25 × 25 m
The pressure-sensitive adhesive sheet of m was attached, and the deviation width (mm) was measured after applying a load of 1 kg in the gravity direction for 1 hour at a temperature of 70 ° C.

The rightmost two columns in FIG. 1 show the test results. In Comparative Examples 1 to 4, when one of the tack and the heat resistance was evaluated as good, the other tended to be bad. On the other hand, in Examples 1 to 6, it was found that the heat resistance can be improved satisfactorily without sacrificing the tack, and these adhesive properties exhibiting contradictory tendencies can be compatible. That is, 16
In Comparative Example 2 in which the polymerized rosin ester having a high softening point of 0 ° C. was used as the tackifier resin, the heat resistance was naturally good, but the tack evaluation was not sufficient. It was found that the heat resistance of Examples 1 and 3 to 5 in which the polymerized rosin ester having a softening point of 150 ° C. or lower was used can be as high as that of Comparative Example 2 or higher. On the other hand, the softening point 10
In Example 2 using 0 ° C rosin ester, the same level of heat resistance as that of Comparative Example 1 using a polymerized rosin ester having a softening point of 140 ° C was shown, and the tack of Example 2 was higher than that of Comparative Example 1. Had been improved. In addition, the softening point 16
Comparing Example 6 and Comparative Example 2 which are common in using the polymerized rosin ester at 0 ° C., the tack was at the same level, but the heat resistance of Example 6 was improved to a higher level than Comparative Example 2. Was there. In this case, it is worth noting that the heat resistance of Example 3 using the polymerized rosin ester having a softening point of 140 ° C. exhibited a high level equivalent to that of Example 6. Therefore, it becomes clear that, when the polymeric emulsifier of the present invention is used, even if a tackifier resin having a softening point not so high is used, the other can be favorably held without sacrificing one of tack and heat resistance. It was

In particular, in order to make it easy to understand the evaluation of the specification of the polymeric emulsifier that disperses the tackifier resin in water, the polymeric rosin ester having the same softening point (140 ° C.) was used by using the polymeric emulsifier. When Example 1 and Examples 3 to 5 and Comparative Examples 3 to 4, which are common in terms of emulsification, are extracted and compared,
In Comparative Examples 3 to 4 using the polymeric emulsifier having an embrittlement temperature lower than the specific range of the present invention, the tack was good, but the heat resistance was low, whereas the polymeric emulsifier of the present invention was used. In Examples 1, 3 to 5 in which No. 2 was used, the tack and heat resistance were both excellently evaluated. Therefore, in the polymeric emulsifier used in the production of the tackifier resin emulsion,
It was revealed that specifying the embrittlement temperature of the copolymer that constitutes the polymer emulsifier greatly contributes to achieving both tackiness and heat resistance, which are adhesive properties exhibiting contradictory tendencies.

[Brief description of drawings]

FIG. 1 shows the types of tackifier resins and emulsifiers used in producing the tackifier resin emulsions of Examples 1 to 6 and Comparative Examples 1 to 4, the test results of the properties of the tackifier resin emulsions, and It is a chart which shows the test result of the adhesive property of the water-based emulsion type acrylic adhesive which used the tackifier resin emulsion.

FIG. 2 shows an apparatus for measuring an embrittlement temperature, FIG. 2A is a schematic perspective view of the apparatus, and FIG. 2B is a schematic sectional view of the apparatus.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09J 193/04 C09J 193/04 F term (reference) 4J040 BA202 DF012 DF042 DF052 DJ012 DN032 HB14 HB23 HD12 HD13 JA03 JB09 KA26 KA38 LA06 LA08

Claims (8)

[Claims] 1. A tackifier resin emulsion in which a tackifier resin is dispersed in water using an emulsifier, wherein the emulsifier is a polymeric emulsifier obtained by saponifying a copolymer having an embrittlement temperature of 110 to 150 ° C. A tackifier resin emulsion characterized by being present. 2. The tackifier resin emulsion according to claim 1, wherein the tackifier resin is a rosin resin, a terpene resin, a petroleum resin, or the like. 3. The tackifier resin emulsion according to claim 1, wherein the tackifier resin is a rosin resin having a softening point of less than 150 ° C. 4. The polymeric emulsifier is a saponified product of a copolymer obtained by reacting a hydrophobic monomer (A) with a polymerizable unsaturated organic acid (B). Any one of three
Item tackifier resin emulsion according to item. 5. The hydrophobic monomer (A) is at least one of (meth) acrylic acid esters and styrene, and the polymerizable unsaturated organic acid (B) is an unsaturated carboxylic acid and an unsaturated sulfone. It is at least one with an acid, The tackifier resin emulsion of Claim 4 characterized by the above-mentioned. 6. The adhesive according to claim 5, wherein the polymerizable unsaturated organic acid (B) is an unsaturated sulfonic acid or a mixture of an unsaturated sulfonic acid and an unsaturated carboxylic acid. Additive resin emulsion. 7. The tackifier resin is dispersed in water using a mixture of a high molecular weight emulsifier and a low molecular weight emulsifier instead of the high molecular weight emulsifier.
Item tackifier resin emulsion according to item. 8. The tackifier resin emulsion according to claim 7, wherein the low molecular weight emulsifier is an organic sulfonate or a sulfate ester salt.