JP2001139919A - Tackifier resin emulsion, method for producing the same and water-based adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based adhesive composition without having an anxiety about endocrine disruptors by using an emulsifying agent excellent in emulsifiability and storage stability of the emulsion and adhesive properties and workability under normal conditions without including substances correspond ing to the endocrine disruptor. SOLUTION: This tackifier resin emulsion is composed of a tackifier resin, an emulsifying agent and water and characterized in that the emulsifying agent is an anionic emulsifying agent represented by the general formula: R-O-(CH2CH2 O)n-X (wherein, R denotes a 10-20C alkyl; (n) denotes an integer of 3-50; and X denotes a sulfosuccinate alkali metal salt group). The tackifier resin emulsion is characterized in that the emulsion is obtained by emulsifying the tackifier resin in the water in the presence of the emulsifying agent. The water-based adhesive composition is characterized by comprising at least one kind of a base polymer selected from the group consisting of an acryl-based polymeric emulsion, a rubber-based latex and a synthetic resin-based emulsion and the tackifier resin emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a tackifier resin emulsion, a method for producing the same, and an aqueous tacky / adhesive composition. More specifically, a tackifier resin capable of providing an aqueous viscous / adhesive composition having excellent storage stability and excellent adhesive properties under ordinary conditions, excellent workability, and no concern about environmental hormones. For emulsions.

[0002]

2. Description of the Related Art Adhesives and adhesives are used in a wide variety of fields such as tapes, sheets, labels, packaging, and building materials. Generally, adhesive properties such as tack are applied to a base polymer such as an acrylic polymer. A tackifier resin has been added for use. Conventionally, solvent-type adhesives have been widely used, but in recent years, aqueous emulsion-type adhesives have various advantages such as no air pollution, excellent safety and health, and suitability for resource saving.・ It is being converted to an adhesive.

Conventionally, water-based adhesives and adhesives include acrylic polymer emulsions, styrene-butadiene copolymer latex, natural rubber latex, chloroprene latex, and the like as base polymers, and rosins, rosin derivatives, and petroleum-based resins. Water-based adhesive / adhesive compositions comprising a tackifier resin emulsion such as a terpene resin are known. Usually, the emulsifier used in such a tackifier resin emulsion includes anionic emulsifiers such as alkylphenyl sulfate, polyoxyethylene alkylphenyl ether sulfate, half-ester salt of sulfosuccinic acid of polyoxyethylene aralkylphenyl ether, and polyoxyethylene alkyl. Nonionic emulsifiers such as phenyl ether are used.

However, when the emulsifier is used, there is a high possibility that it contains a substance corresponding to an environmental hormone, which has recently become a problem, and there is a concern that an environmental hormone problem may occur.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides an emulsifier which is excellent in emulsifiability, storage stability and adhesive properties under ordinary conditions, is excellent in workability, and does not contain an environmental hormone-related substance. It is an object of the present invention to provide an excellent aqueous viscous / adhesive composition having no fear of environmental hormones by using the composition.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies from the viewpoint of the molecular structure of the emulsifier in order to solve the above-mentioned problems of the prior art, and as a result, as an emulsifier for producing a tackifier resin emulsion, It has been found that by selecting a specific anionic emulsifier, it is possible to obtain an excellent aqueous viscous / adhesive composition which is excellent in emulsion stability and free from concern about environmental hormones. The present invention has been completed based on such new knowledge.

That is, the present invention provides a tackifier resin emulsion comprising a tackifier resin, an emulsifier, and water, wherein the emulsifier has a general formula: R—O— (CH ₂ CH ₂ O) _n —X Is an alkyl group having 10 to 20 carbon atoms, and n is 3
X represents an integer of from 50 to 50, and represents an alkali metal sulfosuccinate base. The present invention relates to a tackifier resin emulsion, which is an anionic emulsifier represented by the formula (1): The present invention also relates to a tackifier resin emulsion characterized by emulsifying a tackifier resin in water in the presence of the emulsifier. Furthermore, an acrylic polymer emulsion,
The present invention relates to a water-based adhesive composition comprising at least one base polymer selected from the group consisting of rubber-based latex and synthetic resin-based emulsion and a tackifier resin emulsion.

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

Examples of the rosins include raw rosins of gum rosin, wood rosin and tall oil rosin, and stabilized rosins and polymerized rosins obtained by disproportionating or hydrogenating the raw rosins. Rosin derivatives include rosin esters and rosin phenols. As the rosin esters, a rosin ester obtained by subjecting the rosin and a polyhydric alcohol to an esterification reaction, a raw material rosin is partially fumarated or maleated, and then partially maleated or partially fumaric obtained by esterification Polyhydric alcohol ester of rosin, partially malated or maleated raw rosin, disproportionation, and then esterification to obtain partially maleated or partially fumarated disproportionated rosin polyhydric alcohol ester, etc. Is raised. Rosin phenols refer to those obtained by adding phenols to rosins and thermally polymerizing them, or then esterifying them. Incidentally, the polyhydric alcohol used for the esterification is not particularly limited, diethylene glycol, glycerin,
Trimethylolpropane, trimethylolethane, 1,
Various known compounds such as 2,6-hexanetriol, 1,2,4-butanetriol and pentaerythritol can be exemplified.

The petroleum resins include C5 petroleum resin, C9 petroleum resin, C5-C9 copolymer petroleum resin, cumarone resin, coumarone-indene resin, pure monomer resin, dicyclopentadiene petroleum resin and the like. And terpene resins such as α-
Examples thereof include an aromatic-modified terpene-based resin obtained by copolymerizing a terpene such as a pinene resin, a β-pinene resin, an α-pinene, a β-pinene, and an aromatic monomer such as styrene, and hydrides thereof.

The softening point of these tackifier resins is not particularly limited, and those having a high softening point of 200 ° C. or lower to liquid ones can be appropriately selected and used according to various uses.

In the present invention, the following general formula: R—O— (CH ₂ CH ₂ O) _n —X ( _where R is an alkyl group having 10 to 20 carbon atoms, and n is 3)
X represents an integer of from 50 to 50, and represents an alkali metal sulfosuccinate base. The above tackifier resin is emulsified in water in the presence of the anionic emulsifier represented by the formula (1) to produce a tackifier resin emulsion.

The anionic emulsifier represented by the above general formula can be easily obtained, for example, as follows. The corresponding known polyoxyalkylene ethers are subjected to an esterification reaction with sulfosuccinic anhydride, or the ethers are subjected to an esterification reaction with maleic anhydride to obtain an esterified product, which is then sulfonated. Further, the resulting anion emulsifier is partially or completely neutralized with an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or the like to form a sulfonate, thereby forming a target anionic emulsifier. I can get it.

The alkyl group of the anionic emulsifier represented by the above formula has 10 to 20 carbon atoms (10 to 20 carbon atoms).
An alkyl group as a residue of an alcohol)
If it is less than or greater than 20, the emulsifiability of the tackifier resin will be poor. The polymerization degree (number of moles added) of ethylene oxide is usually 3 to 50, preferably 5 to 2.
If it is less than 3, the emulsifying property is poor. If it is more than 50, the cost of the emulsifier increases, and the resulting tackifier resin emulsion has a disadvantage such as high viscosity.

The amount of the anionic emulsifier is not particularly limited, but is usually about 1 to 10 parts by weight, preferably 2 to 7 parts by weight, based on 100 parts by weight of the tackifier resin.
Parts by weight. When the amount exceeds 10 parts by weight, the water-based adhesive / adhesive composition obtained has reduced water resistance. When the amount is less than 1 part by weight, the storage stability of the resin emulsion during emulsification deteriorates.

The method of emulsifying the tackifier resin is not particularly limited, and any known emulsifying method such as a high-pressure emulsifying method, an inverse emulsifying method, an ultrasonic emulsifying method, and a solvent emulsifying method may be employed. For example, when a high-pressure emulsification method is employed, the tackifier resin is dissolved in a solvent such as benzene or toluene, and then the emulsifier and soft water are added, and emulsification is performed using a high-pressure emulsifier under a pressure condition of about 10 to 50 MPa. After that, the solvent may be removed under reduced pressure.

The solids concentration of the tackifier resin emulsion thus obtained is not particularly limited, but is usually 20 to 7
It is used after being appropriately adjusted to be about 0% by weight. The average particle size of the obtained emulsion is usually 0.2
２2 μm, most of which are uniformly dispersed as particles of 0.5 μm or less. The emulsion has a white to milky white appearance and has a pH value of about 2 to 9.

The water-based tacky / adhesive composition of the present invention is obtained by blending the tackifier resin emulsion with at least one base polymer selected from the group consisting of an acrylic polymer emulsion, a rubber latex and a synthetic resin emulsion. It is made.

The acrylic polymer emulsion used in combination with the tackifier resin emulsion is not particularly limited, and various types can be used. The acrylic polymer emulsion is a (meth) acrylic acid ester (in addition,
(Meth) acrylate refers to acrylate and / or methacrylate, and (meth) has the same meaning hereinafter. ) Batch polymerization method, monomer sequential addition polymerization method, emulsion monomer sequential addition polymerization method,
It can be easily produced by a known emulsion polymerization method such as a seed polymerization method.

The (meth) acrylate used includes, for example, 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 as a mixture of two or more. Further, in order to impart storage stability to the obtained acrylic polymer emulsion, a small amount of (meth) acrylic acid may be used in place of the (meth) acrylic ester. If desired, copolymerizable monomers such as vinyl acetate and styrene can be used in combination to such an extent that the adhesive properties of the (meth) acrylic acid ester polymer are not impaired. The glass transition temperature of these (meth) acrylate-based polymers is usually -7.
The temperature is about 0 to 0 ° C, preferably -60 to -10 ° C. 0
When the temperature exceeds ℃, the tack is remarkably reduced, which is not preferable. As the emulsifier used for the acrylic polymer emulsion, various known ones such as anionic emulsifier, nonionic emulsifier, partially saponified polyvinyl alcohol and the like, which are free from environmental hormone problems, are preferably used. Is 0.1 to 100 parts by weight of the polymer.
It is about 5 parts by weight, preferably 0.5 to 3 parts by weight.

The ratio of the acrylic polymer emulsion and the tackifier resin emulsion is usually about 2 to 40 parts by weight of the tackifier resin emulsion per 100 parts by weight (solid content) of the acrylic polymer emulsion. (In terms of solid content), preferably 5 to 20 parts by weight. When the amount of the tackifier resin emulsion is less than 2 parts by weight, the modification by adding the tackifier resin is hardly recognized, and when it exceeds 40 parts by weight, the cohesive strength tends to decrease. Neither case is appropriate.

As the rubber-based latex used in combination with the tackifier resin emulsion, various known latexes used in aqueous viscosity / adhesive compositions can be used. For example, natural rubber latex, styrene-butadiene copolymer latex, chloroprene latex and the like can be mentioned.

The rubber-based latex and the tackifier resin emulsion are used in an amount of usually 10 to 150 parts by weight (solids conversion) per 100 parts by weight (solids conversion) of the rubber-based latex. And preferably 25 to 100 parts by weight. When the amount of the tackifier resin emulsion is less than 10 parts by weight, almost no modification due to the addition of the tackifier resin is recognized, and when it exceeds 150 parts by weight, the cohesive strength tends to decrease, and Is not appropriate.

Further, the synthetic resin emulsion used in combination with the tackifier resin emulsion includes an aqueous viscous emulsion.
Various known materials used for the adhesive composition can be used,
Examples include synthetic resin emulsions such as vinyl acetate emulsions, ethylene-vinyl acetate copolymer emulsions, and urethane emulsions.

The ratio of the synthetic resin emulsion and the tackifier resin emulsion used is as follows.
It is preferable that the tackifier resin emulsion is usually used in an amount of about 2 to 40 parts by weight (in terms of solid content) based on 00 parts by weight (in terms of solid content). When the amount of the tackifier resin emulsion is less than 2 parts by weight, the modification by adding the tackifier resin is hardly observed, and when the amount exceeds 40 parts by weight, the cohesive strength tends to decrease. Is not appropriate.

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

[0027]

EFFECT OF THE INVENTION The tackifier resin emulsion obtained by the present invention has characteristics such as good storage stability, excellent workability, and no concern about environmental hormones. Further, the obtained water-based pressure-sensitive adhesive / adhesive composition has the characteristics derived from the tackifier resin emulsion, and also has excellent adhesiveness similar to that of the conventional water-based pressure-sensitive adhesive / adhesive composition.

[0028]

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 addition, in each example, parts and% are based on weight.

Production Example 1 (Production Example of Acrylic Polymer Emulsion) In a four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel and a nitrogen inlet tube, at 70 ° C. under a nitrogen gas stream,
43.40 parts of water and 0.92 part of disodium polyoxyethylene alkylsulfosuccinate (alkyl is a synthetic alcohol having 12 to 14 carbon atoms, degree of polymerization of ethylene oxide: 7) as an anionic emulsifier were dissolved. Also,
(1) 45.10 parts of butyl acrylate and 1.40 parts of acrylic acid, and (2) 0.2 catalyst (potassium persulfate)
4 parts, pH adjuster (baking soda) 0.11 part and water 8.83
Parts were dropped from separate dropping funnels, respectively, and a preliminary reaction was carried out at 70 ° C. for 30 minutes under a nitrogen gas flow. Thereafter, 9/10 amounts of (1) and (2) were added to 2/10 parts. The drop polymerization was carried out over time. (1) and (2)
After completion of the dropwise addition, the reaction was completed at 70 ° C. for 1 hour, cooled to room temperature, and taken out while performing 100 mesh wire mesh filtration to obtain an acrylic polymer emulsion having a solid content of 45.7%.

Example 1 100 parts of a polymerized rosin ester having a softening point of 160 ° C. was dissolved in 60 parts of toluene at 100 ° C. for about 1 hour.
Cooled down. Subsequently, 3 parts of polyoxyethylene alkyl sulfosuccinate disodium (alkyl has 12 to 14 carbon atoms, the polymerization degree of ethylene oxide is 7) as a solid content and 3 parts of water and 120 parts of water are added as an emulsifier, and the mixture is added at 75 ° C for 1 hour. Preliminary emulsification was performed by vigorous stirring. Further, the obtained preliminary emulsified product was emulsified under a high pressure of 30 MPa using a high-pressure emulsifier (manton gauulin) to obtain an emulsified product. Next, the above-mentioned emulsion was charged into a vacuum distillation apparatus,
Vacuum distillation was performed for 6 hours under the condition of 0 hPa, and the solid content was 5
A 0% tackifier resin emulsion was obtained.

Example 2, Comparative Examples 1 to 5 An emulsion of a tackifier resin was obtained in the same manner as in Example 1, except that the emulsifier was used in place of the one shown in Table 1.

[0032]

[Table 1]

The workability of the emulsification of the tackifier resin in Examples and Comparative Examples (whether or not emulsion preparation was possible without any problem) was visually judged.
The results are shown in Table 2. 〇: No problem. (Good emulsifying property) Δ: Somewhat problematic. (Slightly poor emulsifying properties. Foaming or generation of a small amount of aggregates is observed.) ×: There is a problem. (Poor emulsifiability. Many occurrences of foaming or aggregates are observed.)

The storage stability of the emulsification of the tackifier resin in Examples and Comparative Examples was evaluated as 40 or more.
After standing for 2 weeks in a constant temperature bath at ℃, the changes over time in viscosity, pH and particle size were measured. The results are shown in Table 2. 〇: No change △: Slight change ×: Change

Performance evaluation of water-based pressure-sensitive adhesive composition Acrylic polymer emulsion 10 obtained in Production Example 1
0 parts (in terms of solids), 10 parts (in terms of solids) of the tackifier resin emulsion obtained in the above Examples and Comparative Examples were mixed, and a thickener (trade name “Primal A”) was further added.
SE-60 "(manufactured by Nippon Acrylic Co., Ltd.) (0.5 parts (in terms of solids)) was added and the mixture was thickened with aqueous ammonia to obtain a pressure-sensitive adhesive composition. The obtained water-based pressure-sensitive adhesive composition has a thickness of 38 μm.
A polyester tape is coated with a dice-type applicator so that the dry film thickness is about 25 μm, then water in the adhesive composition is removed to prepare a sample tape, and various tests are performed by the following performance evaluation methods. Was done.

(Adhesion Performance Test) Adhesion characteristics were evaluated by the following test methods. Table 2 shows the evaluation results. (1) Adhesion A sample tape (width 25 mm x length 150 mm) was stuck on a polypropylene plate, and at 20 ° C according to PSTC-1,
180 ° peeling was performed at a peeling speed of 300 mm / min, and the adhesive force per 25 mm width (g / 25 mm) was measured. (2) Cohesive force: A sample tape (25 mm × 25 mm) was adhered to a stainless steel plate, a 1 kg load was applied at 60 ° C., and the drop time (minute) was measured.

[0037]

[Table 2]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 193/04 C09J 193/04 F-term (Reference) 4J040 BA202 CA001 DF041 DF051 DN032 DN072 EE052 EL012 HD13 JA03 JB09 KA26 KA38 LA05 LA11

Claims (7)

[Claims] 1. A tackifier resin emulsion comprising a tackifier resin, an emulsifier and water, wherein the emulsifier has a general formula: R—O— (CH ₂ CH ₂ O) _n —X ( _where R represents 10 carbon atoms) ~ 20 alkyl groups, n is 3
X represents an integer of from 50 to 50, and represents an alkali metal sulfosuccinate base. A tackifier resin emulsion, which is an anionic emulsifier represented by the formula (1): 2. The tackifier resin emulsion according to claim 1, wherein the tackifier resin is at least one selected from the group consisting of rosins, rosin derivatives, petroleum resins and terpene resins. 3. A general formula: R—O— (CH ₂ CH ₂ O) _n —X (wherein, R is an alkyl group having 10 to 20 carbon atoms, and n is 3)
X represents an integer of from 50 to 50, and represents an alkali metal sulfosuccinate base. (3) emulsifying a tackifier resin in water by employing a high-pressure emulsification method, an inverse emulsification method, an ultrasonic emulsification method or a solvent emulsification method in the presence of an anionic emulsifier represented by the formula (1) and water. A method for producing a tackifier resin emulsion. 4. The method for producing a tackifier resin emulsion according to claim 3, wherein the tackifier resin is at least one selected from the group consisting of rosins, rosin derivatives, petroleum resins and terpene resins. 5. A base polymer selected from the group consisting of an acrylic polymer emulsion, a rubber latex and a synthetic resin emulsion, and at least one base polymer.
Or an aqueous tacky / adhesive composition comprising the tackifier resin emulsion according to item 2 or 2. 6. An acrylic polymer emulsion and / or
Alternatively, 2 to 40 parts by weight (in terms of solid content) of the tackifier resin emulsion according to claim 1 or 2 is blended with respect to 100 parts by weight (in terms of solid content) of the synthetic resin emulsion. Water-based adhesive / adhesive composition. 7. A composition comprising 10 to 150 parts by weight (in terms of solids) of the tackifier resin emulsion according to claim 1 or 2 per 100 parts by weight (in terms of solids) of the rubber latex. 6. The aqueous viscous / adhesive composition according to 5.