JP2002285137A - Tackifying resin emulsion, method for producing the same and aqueous tackifier and adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tackifying resin emulsion having not only excellent productivity in an emulsifying step and storage stability and tackifier and adhe sive characteristics, but also high safety because of containing no aromatic organic solvent such as toluene, and further an aqueous tackifier and adhesive composition obtained by compounding the tackifying resin emulsion and having higher safety and excellent tackifier and adhesive characteristics. SOLUTION: This method for producing a tackifying resin emulsion comprises using an alicyclic organic solvent having low toxicity in place of a conventional aromatic organic solvent for dissolving the tackifying resin in the method for producing the tackifying resin emulsion by emulsifying a tackifying resin in the presence of an emulsifying agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a tackifying resin emulsion, a method for producing the same, and an aqueous viscous / adhesive composition. More specifically, the workability, excellent storage stability, since it does not contain any aromatic organic solvent such as toluene, the load on the human body and the environment is small, a highly safe tackifying resin emulsion and a method for producing the same, In addition, excellent viscosity comprising the tackifying resin emulsion.
The present invention relates to a water-based adhesive / adhesive composition having adhesive properties. The aqueous viscosity / adhesive composition containing the tackifier resin emulsion of the present invention can be suitably used for various applications such as labels, tapes, packaging, and building materials.

[0002]

2. Description of the Related Art Adhesives and adhesives can be broadly classified into solvent type and aqueous type. In recent years, however, they have various advantages such as no air pollution, excellent safety and hygiene, and suitability for resource saving. It is being converted from a solvent system to an aqueous system. The water-based viscous / adhesive is generally composed of a base polymer emulsion, a tackifier resin emulsion for imparting tackiness or the like to the base polymer, other additives, and the like. Is an acrylic polymer emulsion, styrene-
Butadiene copolymer latex, natural rubber latex,
Chloroprene latex and the like are used, and rosins, rosin derivatives, petroleum resins, terpene resins and the like are used as resin components in the tackifier resin emulsion.

[0003] Such a tackifier resin emulsion is generally manufactured by a known method such as a high-pressure emulsification method or an inverse emulsification method. In these emulsification methods, an organic solvent may be used during the manufacturing process for the purpose of lowering the melt viscosity or melt viscosity of the tackifier resin, and although the organic solvent is usually distilled off under reduced pressure, a small amount of the organic solvent is contained in the final product. There is a problem of remaining.

As such organic solvents, aromatic organic solvents such as toluene are generally used from the viewpoints of workability and cost. However, since aromatic organic solvents are highly toxic, they are used in tackifier resin emulsions. The use of adhesives or adhesives with aromatic organic solvents remaining during the manufacturing process may affect the human body and the environment.
In building materials, it may cause sick house syndrome.

On the other hand, emulsification methods without using an organic solvent include an inversion emulsification method under high temperature and high pressure, a high pressure emulsification method under high temperature, and a method using a special high shear type emulsifier. In the method (1), the type and amount of the emulsifier to be used are greatly restricted, and control of emulsification conditions and maintenance of the apparatus are often complicated. In particular, when a tackifying resin having a relatively high softening point is to be emulsified, these effects are easily affected, and as a result, the workability is reduced, and the adhesive properties and storage stability of the obtained tackified resin emulsion are reduced. However, these properties cannot be satisfied at the same time.

[0006]

DISCLOSURE OF THE INVENTION The present invention not only has excellent workability in the emulsification step, storage stability, and viscosity / adhesion properties, but also has a safety that does not include an aromatic organic solvent such as toluene. Providing a high tackifying resin emulsion;
It is a further object of the present invention to provide an aqueous viscous / adhesive composition which is obtained by blending the tackifier resin emulsion and has higher safety and excellent viscous / adhesive properties.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a method for producing a tackifier resin emulsion by emulsifying a tackifier resin in the presence of an emulsifier comprises: By using a low-toxic alicyclic organic solvent instead of the conventional aromatic organic solvent to dissolve the tackifying resin, a tackifying resin emulsion with higher safety and excellent storage stability and adhesive properties Was found to be able to be produced, and it was found that the above problem could be solved by using an aqueous tacky / adhesive composition containing the tackifier resin emulsion, and the present invention was completed.

The present invention provides a method for producing a tackifier resin emulsion by emulsifying a tackifier resin in the presence of an emulsifier, wherein an alicyclic organic solvent is used for dissolving the tackifier resin. The present invention relates to a method for producing a resin emulsion. Further, the tackifying resin emulsion obtained by the production method, and at least one base polymer selected from the group consisting of an acrylic polymer emulsion, a rubber-based latex, and a synthetic resin-based emulsion, contain the tackifying resin emulsion. The present invention relates to a water-based adhesive / adhesive composition.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the tackifier resin emulsion of the present invention will be described. Various known resins can be used as a tackifying resin as a raw material of the emulsion. For example, rosins, rosin derivatives, petroleum resins, terpene resins, phenolic resins, ketone resins,
These can be used alone or as a mixture of two or more.

As the rosins, gum rosin, wood rosin or tall oil rosin; stabilized rosin or polymerized rosin disproportionated or hydrogenated using the rosin;
Further, it is modified with maleic acid, fumaric acid, (meth) acrylic acid ((meth) acrylic acid means acrylic acid and / or methacrylic acid, and (meth) has the same meaning hereinafter). And the like. These can be used singly or as a mixture of two or more.

As the rosin derivative, various known ones derived from the above-mentioned rosins can be used, and specific examples thereof include an esterified product of the rosin, a phenol-modified product and an esterified product thereof. Such an esterified rosin refers to one obtained by subjecting the rosin and a polyhydric alcohol to an esterification reaction, and examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, and neopentyl glycol. Dihydric alcohols; trihydric alcohols such as glycerin, trimethylolethane, and trimethylolpropane;
Examples include tetrahydric alcohols such as pentaerythritol and diglycerin; hexahydric alcohols such as dipentaerythritol, and these can be used alone or in combination of two or more. In addition, phenol-modified rosins and their esterified products are those obtained by adding phenols to the rosins, those obtained by adding phenol to the rosins and then esterified, and those obtained by adding resole-type phenol resins and rosins. It refers to a so-called rosin-modified phenolic resin or its esterified product obtained by the reaction. Among these rosin derivatives, esterified products of the rosins are preferred from the viewpoint of excellent compatibility with various base polymers used in the aqueous viscosity / adhesive composition.

As the petroleum resin, a C5 petroleum resin obtained from pentene, pentadiene, isoprene or the like; indene, methylindene, vinyltoluene, styrene, α
C9 petroleum resin obtained from -methylstyrene, β-methylstyrene, etc .;
C9 copolymer petroleum resin; pure monomer resin; DCP obtained from cyclopentadiene, dicyclopentadiene
D-based petroleum resins; hydrides of these petroleum resins, and the like.

As the terpene resin, α-pinene resin,
Examples thereof include β-pinene resins and aromatic-modified terpene resins obtained by copolymerizing terpenes such as α-pinene and β-pinene with aromatic monomers such as styrene.

As the phenol resin, condensates of phenols and formaldehyde can be used. Examples of the phenols include phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, and the like. And the like can be exemplified. Further, a rosin phenol resin obtained by adding phenol to rosin with an acid catalyst and thermally polymerizing the rosin can also be exemplified.

Examples of the ketone resin include methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexanone, and a condensate of methylcyclohexanone and formaldehyde.

The softening point of these tackifying resins is not particularly limited, but may be 20 or more depending on various uses of the aqueous viscosity / adhesive composition.
A liquid having a high softening point of 0 ° C. or lower can be appropriately selected and used.

As the emulsifier used in the present invention, various known anionic and / or nonionic emulsifiers having a weight average molecular weight of 100,000 or less, preferably 50,000 or less can be used without any particular limitation. When an emulsifier having a weight average molecular weight of more than 100,000 is used, the viscosity of the tackifier resin emulsion tends to be too high. Specific examples of the emulsifier include α-olefin sulfonates, alkyl sulfates, alkyl phenyl sulfates, polyoxyethylene alkyl phenyl ether sulfates, half-ester salts of sulfosuccinic acid of polyoxyethylene aralkyl phenyl ether, and anionic emulsifiers such as rosin soap. Nonionic emulsifiers such as polyoxyethylene alkyl phenyl ether, and the like, and these can be used alone or in combination of two or more. The emulsifier is usually 1 to 1 in terms of solid content based on 100 parts by weight of the tackifier resin.
It is used in an amount of about 0 parts by weight, preferably 1 to 5 parts by weight. When the amount of the emulsifier used is less than 1 part by weight, emulsification becomes difficult, and when the amount is more than 10 parts by weight, the water-resistant and adhesive / adhesive performance of the water-based adhesive composition containing the obtained resin emulsion. Tends to decrease.

In the present invention, an alicyclic organic solvent is indispensable from the viewpoint of various workability in the emulsification step described later and other viewpoints. That is, the solvent is workable during emulsification (reduction of viscosity in the system, occurrence of foaming and agglomerates, emulsion stability, safety and environmental load of the solvent, ease of solvent removal, etc.), and the obtained adhesiveness. It is selected in consideration of the storage stability and the like of the applied resin emulsion. Examples of such alicyclic organic solvents include cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, methylethylcyclohexane and the like, and these can be used alone or in combination of two or more. Above all,
It is preferable to use methylcyclohexane because of low cost and easy distillation under reduced pressure.

Next, a method for producing the tackifier resin emulsion of the present invention will be described. The tackifier resin emulsion of the present invention can be produced by various known emulsification methods, taking into account the workability during emulsification, the storage stability of the obtained tackifier resin emulsion, the effect on aqueous viscosity and adhesive properties, and the like. Then, a high-pressure emulsification method through an operation of high-pressure emulsification is preferred. In the case of using a high-pressure emulsification method, first, the tackifier resin is dissolved in an appropriate amount of an alicyclic organic solvent, the emulsifier and soft water are added thereto, pre-emulsification is performed, and then emulsification is performed using a high-pressure emulsifier. By removing the organic solvent together with water under reduced pressure, the desired tackifier resin emulsion can be obtained. The pressure during high-pressure emulsification is usually 10 to 5
It is about 0 MPa, preferably 20 to 40 MPa. When the pressure is lower than 10 MPa, it is difficult to obtain a tackifier resin emulsion having a uniform particle diameter, and when the pressure is higher than 50 MPa, maintenance of the emulsifying apparatus becomes complicated.

The solid content concentration of the tackifying resin emulsion obtained by the above method is not particularly limited and can be appropriately determined according to the intended use, but is usually about 20 to 70% by weight. The emulsion has a white or milky white appearance, usually has an average particle size of about 0.2 to 2 μm, and is mostly uniformly dispersed as particles of 0.5 μm or less. The pH value is usually about 2 to 9, and the viscosity is usually 10 to 10.
It is about 500 mPa · s.

Next, the water-based adhesive / adhesive composition of the present invention will be described. Such an aqueous viscous / adhesive composition is obtained by blending the tackifier resin emulsion of the present invention 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.

As the acrylic polymer emulsion,
A variety of known materials used in acrylic adhesives and adhesives can be used. These emulsions are prepared by batch charging polymerization of monomers such as (meth) acrylic acid ester, monomer sequential addition polymerization, emulsion monomer sequential addition polymerization, It can be easily produced by a known emulsion polymerization method such as a seed polymerization method. Specific examples of the (meth) acrylate include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylate.
Examples thereof include 2-ethylhexyl acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and the like.
More than one species can be used in combination. Further, for the purpose of imparting storage stability to the obtained emulsion, a small amount of (meth) acrylic acid can be used in combination with the (meth) acrylic ester. Further, copolymerizable monomers such as vinyl acetate and styrene can be used together as long as the viscosity and adhesive properties of the aqueous viscosity and adhesive composition of the present invention are not impaired. As the emulsifier used for the acrylic polymer emulsion, an anionic emulsifier, a partially saponified polyvinyl alcohol, or the like can be used.
About 5 parts by weight, preferably 0.5 to 3 parts by weight.
If the amount is less than 0.1 part by weight, it is difficult to obtain a stable emulsion having a uniform particle size, and if it is more than 5 parts by weight, the water resistance and the adhesiveness / adhesive properties of the aqueous adhesive / adhesive composition tend to decrease.

The amount of the tackifying resin emulsion of the present invention to be used in the acrylic polymer emulsion is usually 2 to 4 parts by weight per 100 parts by weight (in terms of solid content) of the acrylic polymer emulsion.
It is about 0 parts by weight (in terms of solid content). When the amount used is less than 2 parts by weight, little improvement in the viscosity / adhesion properties of the resulting water-based adhesive / adhesive composition is observed.
If the amount exceeds the weight part, the cohesive strength tends to decrease.

As the rubber-based latex, various known ones used for an aqueous-based adhesive / adhesive composition can be used without any particular limitation. Specific examples include natural rubber latex, styrene-butadiene copolymer latex, chloroprene latex, and the like. The amount of the tackifier resin emulsion used for the rubber latex is 10
The tackifier resin emulsion is usually about 10 to 150 parts by weight (in terms of solids) with respect to 0 parts by weight (in terms of solids). When the amount used is less than 10 parts by weight, little improvement in the viscosity and adhesive properties of the resulting water-based adhesive composition is observed, while when it exceeds 150 parts by weight, the cohesive strength decreases. There is a tendency.

The synthetic resin emulsion can be used without any particular limitation as long as it is various known ones used in aqueous adhesive compositions. Specific examples include vinyl acetate emulsions, ethylene-vinyl acetate copolymer emulsions, and urethanes. System emulsion and the like. The amount of the tackifier resin emulsion used with respect to the synthetic resin emulsion is usually 2 to 100 parts by weight (solid content) of the synthetic resin emulsion.
It is about 40 parts by weight (in terms of solid content). When the amount used is less than 2 parts by weight, little improvement in the viscosity and adhesion properties of the resulting water-based viscosity and adhesive composition is observed.
If it exceeds 0 parts by weight, the cohesive strength tends to decrease.

The aqueous viscosity / adhesive composition of the present invention may be used together with an antifoaming agent, a thickening agent, a filler, an antioxidant, a water-proofing agent, a film-forming aid and the like, if necessary. Can also.

[0027]

The tackifier resin emulsion of the present invention comprises:
Since a conventionally used highly toxic aromatic organic solvent such as toluene is not used, there is little adverse effect on the human body and environmental load, and excellent storage stability and tackifying effect.
Further, according to the method for producing a tackifier resin emulsion of the present invention, it is possible to realize excellent workability with almost no occurrence of foaming or aggregates in the emulsification step. Further, an aqueous viscosity / adhesive composition obtained by blending the tackifier resin emulsion,
Possesses the effect due to the tackifying resin emulsion,
Develops excellent adhesive and adhesive properties.

[0028]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Production Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples. In each example, all parts and percentages are by weight unless otherwise specified.

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,
44.46 parts of water and an anionic emulsifier (trade name “HITENOL S”, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., solid content 50%)
0.90 parts were completely dissolved. Next, (1) a mixture of 43.90 parts of butyl acrylate and 1.36 parts of acrylic acid, (2) 0.23 part of a catalyst (potassium persulfate),
A mixture consisting of 0.11 part of a pH adjuster (baking soda) and 9.04 parts of water was mixed with 1/1 from each dropping funnel.
A 0-volume drop was added, and the mixture was stirred at 70 ° C. for 30 minutes under a nitrogen gas stream to perform a preliminary reaction. Thereafter, the remaining 9/10 amount of each of (1) and (2) was added dropwise over 2 hours with stirring to carry out a polymerization reaction. After dropping all of (1) and (2), a complete reaction was carried out at 70 ° C. for 1 hour, and after cooling to room temperature, it was taken out while performing 100 mesh wire gauze filtration to obtain an acrylic acrylic having a solid content of 45.7%. A polymer emulsion was obtained.

Example 1 Disproportionated rosin ester having a softening point of 100 ° C. (trade name “Super Ester A-100”, manufactured by Arakawa Chemical Industry Co., Ltd.)
00 parts and methylcyclohexane 60 as an alicyclic solvent
The mixture was completely dissolved at 100 ° C. for about 1 hour, and then cooled to 80 ° C. Next, an anionic emulsifier (trade name “HITENOL S”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
5 parts of solid content 50%) and 120 parts of soft water were added, and 75 parts of
Preliminary emulsification was performed by vigorous stirring at 1 ° C for 1 hour. Further, the obtained pre-emulsion was emulsified at a pressure of 30 MPa using a high-pressure emulsifier (trade name “high-pressure homogenizer”, manufactured by APV Gaulin) to obtain an emulsion. Next, the emulsion was charged into a vacuum distillation apparatus, and vacuum distillation was performed at 50 ° C. and 130 hPa for 6 hours, and the solid content was 50%, pH5, viscosity was 30 mPa · s, and average particle diameter was 0.46 μm (laser diffraction particle size). Distribution measuring device, trade name "SALD-200
0 "(measured using Shimadzu Corporation).

Example 2 A tackifying resin was prepared by polymerizing a rosin ester having a softening point of 160 ° C. (trade name “Pencel D-160”, Arakawa Chemical Industry Co., Ltd.)
And a solid content of 50%, a pH of 5, a viscosity of 25 mPa · s, and an average particle diameter of 0.47 μm in the same manner as in Example 1 except that the amount of methylcyclohexane, which is an alicyclic solvent, was changed to 80 parts. A tackifier resin emulsion was obtained.

Comparative Example 1 A solid content of 50%, a pH of 5, a viscosity of 25 mPa · s, and an average were set in the same manner as in Example 1 except that the kind of the organic solvent used for dissolving the tackifying resin and the amount of the solvent used were changed to 50 parts of toluene. A tackifier resin emulsion having a particle size of 0.48 μm was obtained.

Comparative Example 2 A solid content of 50%, a pH of 5, a viscosity of 20 mPa · s, and an average were obtained in the same manner as in Example 2, except that the kind of the organic solvent used for dissolving the tackifier resin and the amount of the solvent used were changed to 60 parts of toluene. A tackifier resin emulsion having a particle size of 0.46 μm was obtained.

[0034]

[Table 1]

(Workability test) In each of the examples and comparative examples, the workability (foaming or agglomeration) when the tackifying resin was emulsified was visually observed and evaluated according to the following criteria. Table 2 shows the results. Good: Almost no foaming or agglomeration occurred, and excellent workability. Δ: Foaming or agglomeration was observed, and workability was slightly inferior. ×: Many occurrences of foaming or aggregates are observed, and workability is poor.

(Storage stability test) The emulsion of the tackifying resin obtained in each of the examples and comparative examples was allowed to stand in a constant temperature bath at 40 ° C for 2 weeks, and then the viscosity, pH and particle size change over time were measured. , Storage stability was determined. Table 2 shows the results. ：: No change over time, excellent in storage stability. Δ: There is a slight change with time, and the storage stability is slightly inferior. X: There is a change with time, and storage stability is poor.

(Evaluation of Performance of Water-Based Adhesive Composition) Production Example 1
Was mixed with 100 parts (in terms of solids) of the acrylic polymer emulsion obtained in (1), and 10 parts (in terms of solids) of the tackifying resin emulsion obtained in each of Examples and Comparative Examples. Name "Primal ASE-6"
0 ", manufactured by Nippon Acrylic Co., Ltd.) 0.5 parts (solid conversion)
Was added, and an appropriate amount of about 7% aqueous ammonia was added to adjust the pH to about 8 to increase the viscosity to obtain an aqueous pressure-sensitive adhesive composition.
This aqueous pressure-sensitive adhesive composition was applied to a 38 μm-thick polyester film (trade name “S-100”, manufactured by Diafoil Hoechst Co., Ltd.) using a dice-type applicator (manufactured by Daisuke Kiki Co., Ltd.) to have a dry film thickness of about 25 μm. And then dried in a circulating drier at 105 ° C. for 5 minutes to prepare a film for a sample tape, which was subjected to various tests by the following performance evaluation methods.

(Adhesive Performance Test) Adhesive properties were evaluated by the following test methods. Table 2 shows the evaluation results. (1) Adhesiveness From the sample tape film to the sample tape (25 mm wide)
× length 150 mm), this was adhered to a polypropylene plate, and peeled at 180 ° at a peeling speed of 300 mm / min at 23 ° C. according to PSTC-1, and the adhesive force (g per 25 mm width at that time) / 25 mm). (2) Cohesive force From the sample tape film to the sample tape (25 mm ×
25mm), and paste this on a stainless steel plate.
A 1 kg load was applied at 60 ° C., and the drop time (min) was measured.

[0039]

[Table 2]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C09J 161/00 C09J 161/00 193/00 193/00 F term (reference) 4J040 BA202 CA011 CA121 DA051 DB051 DE021 DF041 DF051 DN032 DN072 EB012 EB032 EF001 HB02 HB22 HD12 HD13 JA03 JB09 NA05 NA06 NA12

Claims (9)

[Claims] 1. A method for producing a tackifier resin emulsion by emulsifying a tackifier resin in the presence of an emulsifier,
A method for producing a tackifier resin emulsion, comprising using an alicyclic organic solvent for dissolving the tackifier resin. 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, terpene resins, phenol resins, and ketone resins. Manufacturing method. 3. The method for producing a tackifier resin emulsion according to claim 1, wherein the emulsifier is an anionic and / or nonionic emulsifier. 4. The alicyclic organic solvent comprises cyclohexane,
The method for producing a tackifier resin emulsion according to any one of claims 1 to 3, wherein the method is at least one of methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, and methylethylcyclohexane. 5. The method for producing a tackifier resin emulsion according to claim 1, wherein the emulsification step includes an operation of high-pressure emulsification. 6. A tackifier resin emulsion obtained by the method for producing a tackifier resin emulsion according to claim 1. 7. An aqueous viscous solution containing at least one base polymer selected from the group consisting of an acrylic polymer emulsion, a rubber-based latex and a synthetic resin-based emulsion, and the tackifier resin emulsion according to claim 6. Adhesive composition. 8. An acrylic polymer emulsion and / or
Alternatively, 2 to 40 parts by weight (in terms of solid content) of the tackifying resin emulsion according to claim 6 is blended with 100 parts by weight (in terms of solid content) of the synthetic resin emulsion. -An adhesive composition. 9. The composition according to claim 7, wherein 10 to 150 parts by weight (in terms of solids) of the tackifier resin emulsion according to claim 6 is blended with 100 parts by weight (in terms of solids) of the rubber-based latex. Water-based adhesive / adhesive composition.