阅读说明：本技术 增粘树脂乳液、水系粘合和/或胶粘剂组合物以及粘合和/或胶粘片 (Tackifier resin emulsion, water-based adhesive and/or cohesive agent composition, and adhesive and/or cohesive sheet ) 是由 佐野正英 小川寿子 于 2020-03-05 设计创作，主要内容包括：本发明涉及增粘树脂乳液、水系粘合和/或胶粘剂组合物以及粘合和/或胶粘片。提供一种增粘树脂乳液,其可提供在保持对各种基材的胶粘力以及粘合和/或胶粘剂层的保持力的同时对聚烯烃类树脂的曲面胶粘性优良的水系粘合和/或胶粘剂组合物,并且与基础聚合物的相容性优良。一种增粘树脂乳液,其包含软化点为120～180℃的松香类树脂(A)、<Sup>1</Sup>H-NMR谱图中的6.3～7.6ppm的峰面积值(S’<Sub>NMR</Sub>)相对于全部峰面积值(S<Sub>NMR</Sub>)的比率(S’<Sub>NMR</Sub>/S<Sub>NMR</Sub>)为0～4.0％的石油树脂(B)和乳化剂(C)。(The present invention relates to a tackifier resin emulsion, a water-based adhesive and/or cohesive agent composition, and an adhesive and/or cohesive sheet. To provide a tackifier resin emulsion which can provide a good adhesive holding effect to various substratesThe aqueous adhesive and/or adhesive composition has excellent adhesion to a curved surface of a polyolefin resin, excellent holding power of an adhesive and/or adhesive layer, and excellent compatibility with a base polymer. A tackifier resin emulsion comprising a rosin resin (A) having a softening point of 120 to 180℃, 1 6.3 to 7.6ppm peak area value (S ') in H-NMR spectrum' NMR ) Relative to the total peak area value (S) NMR ) Ratio of (S' NMR /S NMR ) 0-4.0% of petroleum resin (B) and emulsifier (C).)

1. A tackifying resin emulsion comprising:

a rosin resin (A) having a softening point of 120 to 180℃,

¹6.3 to 7.6ppm peak area value S 'in H-NMR spectrum'_NMRRelative to the total peak area value S_NMRRatio S of'_NMR/S_NMR0 to 4.0% of petroleum resin (B), and

an emulsifier (C).

2. The tackifier resin emulsion according to claim 1, wherein the component (A) is a polymerized rosin ester and/or a rosin phenol resin.

3. The tackifier resin emulsion according to claim 1 or 2, wherein the component (B) is at least one petroleum resin selected from the group consisting of aliphatic petroleum resins, alicyclic petroleum resins and hydrogenated petroleum resins.

4. A tackifier resin emulsion according to any one of claims 1 to 3, wherein the weight average molecular weight of the component (B) is 500 to 4000.

5. The tackifier resin emulsion according to any one of claims 1 to 4, wherein the mass ratio (A)/(B) of the component (A) to the component (B) is from 60/40 to 99/1 in terms of solid content.

6. A water-based adhesive and/or cohesive composition comprising the tackifying resin emulsion of any one of claims 1 to 5 and a base polymer.

7. The water-based bonding and/or adhesive composition of claim 6, wherein the base polymer is an acrylic polymer emulsion.

8. An adhesive and/or pressure-sensitive adhesive sheet comprising an adhesive and/or pressure-sensitive adhesive layer composed of the water-based adhesive and/or pressure-sensitive adhesive composition according to claim 6 or 7 and a substrate.

Technical Field

The present invention relates to a tackifier resin emulsion, a water-based adhesive and/or cohesive agent composition, and an adhesive and/or cohesive sheet.

Background

In general, polyolefin resins such as polyethylene and polypropylene used for food packaging and exterior packaging of electronic and electrical products have no functional group and are nonpolar, and therefore have poor affinity with polar molecules, very weak adhesion to adhesives and wettability, and easy peeling. Therefore, a method of modifying the adhesive surface by coating a primer on the adhesive surface is generally used, but there is a strong demand for an adhesive and/or a pressure-sensitive adhesive having sufficient adhesive strength to polyolefin resin, particularly, adhesiveness to curved surfaces, without using a primer.

In recent years, water-based adhesives and/or adhesives that contain a small amount of volatile organic solvents and the like and reduce environmental load have been demanded for safety concerns about the environment and human bodies. However, if the organic solvent-based adhesive and/or the adhesive is changed to a water-based adhesive, there is a problem that the adhesiveness to the curved surface of the polyolefin-based resin is insufficient. In addition to curved surface adhesiveness, water-based adhesives and adhesives are required to have adhesive strength to various substrates, adhesion, holding power of an adhesive layer, and the like.

As an aqueous adhesive and/or a pressure-sensitive adhesive having improved adhesiveness to a curved surface of a polyolefin-based resin, for example, patent document 1 proposes an emulsion-type pressure-sensitive adhesive comprising an acrylic copolymer and a tackifier resin emulsion derived from a rosin-based tackifier resin and a C5/C9 copolymerized petroleum resin.

Disclosure of Invention

Problems to be solved by the invention

However, the emulsion adhesive of patent document 1 has insufficient adhesiveness to a curved surface of a polyolefin resin, and there is room for improvement. In addition, the above tackifier resin emulsion has the following problems: the emulsion-type adhesive containing the emulsion has low transparency because compatibility with an acrylic copolymer as a base polymer is insufficient.

The invention provides a tackifier resin emulsion which can provide a water-based adhesive and/or an adhesive composition having excellent adhesiveness to a curved surface of a polyolefin resin while maintaining the adhesiveness to various substrates and the holding power of an adhesive and/or an adhesive layer, and has excellent compatibility with a base polymer.

Means for solving the problems

As a result of intensive studies, the present inventors have found that the above problems can be solved by a tackifier resin emulsion using a combination of a rosin-based resin having a specific softening point and a specific petroleum resin. That is, the present invention relates to the following tackifier resin emulsion, water-based adhesive and/or cohesive agent composition, and adhesive and/or cohesive sheet.

1. A tackifying resin emulsion comprising:

a rosin resin (A) having a softening point of 120 to 180℃,

¹6.3 to 7.6ppm peak area value (S ') in H-NMR spectrum'_NMR) Relative to the total peak area value (S)_NMR) Ratio of (S'_NMR/S_NMR)0 to 4.0% of petroleum resin (B), and

an emulsifier (C).

2. The tackifier resin emulsion according to claim 1, wherein the component (A) is a polymerized rosin ester and/or a rosin phenol resin.

3. The tackifier resin emulsion according to item 1 or 2, wherein the component (B) is at least one petroleum resin selected from the group consisting of aliphatic petroleum resins, alicyclic petroleum resins and hydrogenated petroleum resins.

4. The tackifier resin emulsion according to any one of items 1 to 3, wherein the component (B) has a weight average molecular weight of 500 to 4000.

5. The tackifier resin emulsion according to any one of items 1 to 4, wherein a mass ratio ((A)/(B)) of the component (A) to the component (B) is 60/40 to 99/1 in terms of solid content.

6. A water-based adhesive and/or cohesive agent composition comprising the tackifier resin emulsion described in any one of items 1 to 5 above and a base polymer.

7. The water-based adhesive and/or cohesive agent composition according to claim 6, wherein the base polymer is an acrylic polymer emulsion.

8. An adhesive and/or pressure-sensitive adhesive sheet comprising an adhesive and/or pressure-sensitive adhesive layer composed of the water-based adhesive and/or pressure-sensitive adhesive composition described in the above item 6 or 7 and a base material.

Effects of the invention

The tackifier resin emulsion of the present invention can provide an aqueous adhesive and/or adhesive composition having excellent adhesiveness to a curved surface of a polyolefin resin while retaining the adhesive force to various substrates, the adhesion, the holding force of an adhesive layer, and the like. Further, since the tackifier resin emulsion of the present invention is excellent in compatibility (hereinafter also referred to as compatibility) with the base polymer in the aqueous adhesive and/or the adhesive composition, the aqueous adhesive and/or the adhesive composition containing the emulsion has high transparency, and is suitable as an adhesive and/or an adhesive in applications requiring transparency and design properties, for example, an adhesive and/or an adhesive for a transparent label used for a cosmetic container and a shampoo container.

Detailed Description

[ tackifying resin emulsion ]

The tackifier resin emulsion of the present invention comprises a rosin resin (A) (hereinafter referred to as component (A)) having a softening point of 120 to 180 ℃, (B) a tackifier resin, and (C) a tackifier resin,¹Peak area value (S ') of 6.3 to 7.6ppm in H-NMR spectrum'_NMR) Relative to the total peak area value (S)_NMR) Ratio of (S'_NMR/S_NMR)0 to 4.0% of a petroleum resin (B) (hereinafter referred to as component (B)) and an emulsifier (C) (hereinafter referred to as component (C)).

< rosin-based resin (A) >

The component (A) has a softening point of 120 to 180 ℃. When the softening point of the component (A) is less than 120 ℃, the adhesiveness to a curved surface is insufficient and the holding power is reduced. When the softening point of the component (A) exceeds 180 ℃, the compatibility is lowered and the adhesiveness to a curved surface is insufficient. The softening point of the component (a) is preferably from about 130 to about 160 ℃, more preferably from about 140 to about 160 ℃ from the viewpoint of an excellent balance among the adhesiveness to a curved surface, the compatibility, the adhesive strength, and the holding power. In the present specification, the softening point is a value measured by the ring and ball method (JISK 5902).

As the component (A), various known rosin resins can be used without particular limitation as long as the softening point thereof is 120 to 180 ℃. Examples of the component (a) include polymerized rosin, α, β -unsaturated carboxylic acid-modified rosin, rosin esters, and rosin phenol resin. These may be used alone or in combination of two or more.

The polymerized rosin is a rosin derivative containing dimerized resin acids.

As a method for producing the polymerized rosin, a known method can be used. Specifically, for example, a method of reacting natural rosin (gum rosin, tall oil rosin, wood rosin) derived from masson pine, slash pine, southern pine, pinus khasys, loblolly pine, jowar pine, or the like and/or purified rosin obtained by purifying natural rosin by a vacuum distillation method, a steam distillation method, an extraction method, a recrystallization method, or the like (hereinafter, natural rosin and purified rosin are collectively referred to as raw material rosin) in a solvent such as toluene, xylene, or the like containing a catalyst such as sulfuric acid, hydrogen fluoride, aluminum chloride, titanium tetrachloride, or the like at a temperature of about 40 ℃ to about 160 ℃ for about 1 hour to about 5 hours, and the like can be mentioned.

Specific examples of the polymerized rosin include gum-based polymerized rosins (for example, trade name "polymerized rosin B-140", manufactured by newcastle linning limited), tall oil-based polymerized rosins (for example, trade name "シルバタック 140", manufactured by arizona chemical company), which use tall oil rosins, and wood-based polymerized rosins (for example, trade name "ダイマレックス", manufactured by ASHLAND corporation), which use wood rosins, which use gum rosins among the raw material rosins.

The polymerized rosin may be obtained by subjecting the polymerized rosin to various treatments such as hydrogenation, disproportionation, acrylation, maleation, and fumaration. Further, each process may be performed alone or two or more kinds may be performed in combination. The polymerized rosin is preferably one obtained by acrylation, maleation or fumaration.

The α, β -unsaturated carboxylic acid-modified rosin is a modified rosin obtained by addition reaction of the raw material rosin with an α, β -unsaturated carboxylic acid.

The α, β -unsaturated carboxylic acid is not particularly limited, and various known α, β -unsaturated carboxylic acids can be used. Specific examples thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, muconic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, and muconic anhydride. Among them, acrylic acid, maleic anhydride and fumaric acid are preferable. The amount of the α, β -unsaturated carboxylic acid used is usually about 1 to about 20 parts by mass, preferably about 1 to about 3 parts by mass, based on 100 parts by mass of the raw material rosin, from the viewpoint of emulsifiability.

The method for producing the α, β -unsaturated carboxylic acid-modified rosin is not particularly limited, and examples thereof include a method in which the α, β -unsaturated carboxylic acid is added to the raw rosin melted under heating, and the mixture is reacted at a temperature of about 180 to about 240 ℃ for about 1 to about 9 hours. The reaction may be carried out while blowing an inert gas such as nitrogen into the closed reaction system. In the above reaction, for example, a known catalyst such as a lewis acid such as zinc chloride, ferric chloride, and tin chloride, or a bronsted acid such as p-toluenesulfonic acid and methanesulfonic acid can be used. The amount of these catalysts used is usually about 0.01 to about 10% by mass based on the above raw material rosin.

The obtained α, β -unsaturated carboxylic acid-modified rosin may contain resin acids derived from the above raw material rosin.

The rosin esters are rosin esters, polymerized rosin esters, and unsaturated carboxylic acid-modified rosin esters, which will be described later.

The rosin ester is obtained by reacting an alcohol with the raw material rosin, a hydrogenated rosin obtained by hydrogenating the raw material rosin, or a disproportionated rosin obtained by disproportionating the raw material rosin.

The reaction of the rosin and the alcohol may be carried out at about 250 to about 280 ℃ for about 1 to about 8 hours by adding an esterification catalyst as necessary in the presence or absence of a solvent.

The alcohols are not particularly limited, and examples thereof include monohydric alcohols such as methanol, ethanol, propanol and stearyl alcohol, dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol and dihydric alcohols, trihydric alcohols such as glycerin, trimethylolethane and trimethylolpropane, tetrahydric alcohols such as pentaerythritol and diglycerin, and hexahydric alcohols such as dipentaerythritol. Among these, polyhydric alcohols having two or more hydroxyl groups are preferable, and pentaerythritol is particularly preferable.

The polymerized rosin ester is obtained by reacting an alcohol with the polymerized rosin.

The reaction conditions of the polymerized rosin and the alcohol may be such that the polymerized rosin and the alcohol are reacted at about 250 to about 280 ℃ for about 1 to about 8 hours by adding an esterification catalyst as necessary in the presence or absence of a solvent.

The alcohols used for esterifying the polymerized rosin are the same as described above.

The order of the polymerization reaction and the esterification reaction is not limited to the above-mentioned order, and the polymerization reaction may be carried out after the esterification reaction.

The physical properties of the polymerized rosin ester are not particularly limited. The physical properties of the polymerized rosin ester are preferably a softening point of about 150 to about 180 ℃ from the viewpoint of excellent curved surface adhesiveness, adhesive strength and holding power.

The unsaturated carboxylic acid-modified rosin ester is obtained by reacting an alcohol with the α, β -unsaturated carboxylic acid-modified rosin and esterifying the reaction product.

The reaction conditions of the α, β -unsaturated carboxylic acid-modified rosin and the alcohol are not particularly limited, and examples thereof include adding an alcohol to an α, β -unsaturated carboxylic acid-modified rosin melted under heating, and reacting at a temperature of about 250 to about 280 ℃ for about 15 to about 20 hours. The reaction may be carried out while blowing an inert gas such as nitrogen into the closed reaction system, and the catalyst may be used.

The alcohols used for esterifying the α, β -unsaturated carboxylic acid-modified rosin are the same as described above.

The rosin phenol resin is obtained by reacting a phenol with the raw material rosin.

The phenol is not particularly limited, and various known phenols can be used. Specifically, there may be mentioned alkylphenols such as cresol, butylphenol, octylphenol and nonylphenol, phenol, bisphenol and naphthol. These may be used alone or in combination of two or more. From the viewpoint of emulsifiability, the phenol may be used in an amount of usually about 0.8 mol to about 1.5 mol based on 1 mol of the raw material rosin.

The method for producing the rosin phenol resin is not particularly limited, and examples thereof include a method in which the above raw materials rosin and phenol are reacted by heating in the presence of an acid catalyst as necessary. The reaction temperature is usually 180 to 350 ℃ for about 6 to 18 hours. The acid catalyst that can be used in the reaction is not particularly limited, and examples thereof include: inorganic acid catalysts such as sulfuric acid, hydrogen chloride, boron trifluoride, etc.; organic acid catalysts such as p-toluenesulfonic acid and methanesulfonic acid. When an acid catalyst is used, the amount of the acid catalyst may be about 0.01 to about 1.0 part by mass per 100 parts by mass of the raw material rosin. The rosin phenol resin may be a resin esterified by further reacting an alcohol with the resin obtained by the above reaction. The alcohols used in this case are the same as described above.

The component (a) is preferably the rosin ester and/or the rosin phenol resin from the viewpoint of excellent balance among the adhesiveness to a curved surface, the compatibility, the adhesive strength, and the holding power. The rosin ester is more preferably the polymerized rosin ester from the viewpoint of excellent balance among the adhesiveness to a curved surface, the compatibility, the adhesive strength, and the holding power.

< Petroleum resin (B) >

As component (B), it¹6.3 to 7.6ppm peak area value (S ') in H-NMR spectrum'_NMR) Relative to the total peak area value (S)_NMR) Ratio of (S'_NMR/S_NMR) (hereinafter referred to as "S'_NMR/S_NMR)0 to 4.0% by percentage. (S'_NMR/S_NMR) If the content exceeds 4.0%, the water-based adhesive and/or the curved surface adhesiveness of the adhesive composition may be insufficient.

In the present specification, the above-mentioned "6.3 to 7.6 ppm" means that¹And (B) a region in which a (signal) peak derived from an aromatic ring contained in the component (B) appears in an H-NMR spectrum. In addition, the peak of "6.3 to 7.6 ppm" may be a peak which is considered to be derived from an aromatic ring. Namely, the above (S'_NMR/S_NMR) The content ratio of the aromatic ring component such as benzene ring in the component (B) is defined. In the present specification, peaks derived from an NMR measurement solvent (deuterated chloroform, etc.) are removed from all peaks appearing in the above-mentioned "6.3 to 7.6 ppm". In addition, "all peak area value (S)_NMR) The term "includes no integral value of a peak derived from an NMR measurement solvent.

The tackifier resin emulsion of the present invention is obtained by using the component (A) and the component (S)'_NMR/S_NMR) The component (B) in a specific range maintains compatibility in an aqueous adhesive and/or an adhesive composition, and is excellent in curved surface adhesiveness. The detailed reason is not clear, but the following reason is presumed. In component (B), (S'_NMR/S_NMR)0 to 4.0% means that the content of the aromatic ring component is low or 0, and therefore, it can be said that the polarity of the component (B) is low. It is also presumed that the component (B) having a low polarity has a good affinity for the polyolefin-based resin having a low polarity.

The component (B) is the above-mentioned (S'_NMR/S_NMR) Preferably from about 0 to about 1.0%.

Component (B) is not limited to the above-mentioned (S'_NMR/S_NMR) The content of the polymer is 0 to 4.0%, and various known petroleum resins can be used without any particular limitation. From the viewpoint of excellent adhesiveness to a curved surface, (B) hasPreferably at least one petroleum resin selected from the group consisting of aliphatic petroleum resins, alicyclic petroleum resins and hydrogenated petroleum resins.

Examples of the aliphatic petroleum resin include C5-based petroleum resins obtained from a C5 petroleum fraction of naphtha. Examples of the C5 petroleum fraction include: c4-6 conjugated diolefinic unsaturated hydrocarbons represented by isoprene, trans-1, 3-pentadiene, cis-1, 3-pentadiene, cyclopentadiene, methylcyclopentadiene, and the like; monoolefinic unsaturated hydrocarbon having 4 to 6 carbon atoms, represented by butene, 2-methyl-1-butene, 2-methyl-2-butene, 1-pentene, 2-pentene, cyclopentene and the like; aliphatic saturated hydrocarbons such as cyclopentane, 2-methylpentane, 3-methylpentane and n-hexane; mixtures thereof and the like.

Examples of the alicyclic petroleum resin include DCPD-based petroleum resins obtained from dicyclopentadiene petroleum fractions of naphtha. The dicyclopentadiene-based petroleum fraction includes, for example: c10 cyclic aliphatic compounds such as dicyclopentadiene; a cyclic aliphatic compound having 11 carbon atoms such as methyldicyclopentadiene; a C12 cyclic aliphatic compound such as dimethyldicyclopentadiene; mixtures thereof and the like.

Examples of the hydrogenated petroleum resin include hydrogenated products of petroleum resins such as the above aliphatic petroleum resin, the above alicyclic petroleum resin, aromatic petroleum resin, and aliphatic/aromatic petroleum resin.

Examples of the aromatic petroleum resin include a C9-based petroleum resin obtained from a C9 petroleum fraction of naphtha, and a copolymer obtained by polymerizing one or more of the C9-based petroleum resins. Examples of the C9 petroleum fraction include: aromatic compounds having 8 carbon atoms such as styrene; aromatic compounds having 9 carbon atoms such as α -methylstyrene, β -methylstyrene, vinyltoluene, indene and the like; aromatic compounds having 10 carbon atoms such as 1-methylindene, 2-methylindene and 3-methylindene; aromatic compounds having 11 carbon atoms such as 2, 3-dimethylindene and 2, 5-dimethylindene; mixtures thereof and the like.

Examples of the aliphatic/aromatic petroleum resin include C5/C9 copolymer petroleum resins obtained from the above-mentioned C5 petroleum fraction and C9 petroleum fraction.

When the aromatic petroleum resin and the aliphatic/aromatic petroleum resin are used as component (B), their (S ') is'_NMR/S_NMR) In many cases, the amount exceeds 4.0%, and therefore, the aqueous adhesive and/or the curved surface adhesiveness of the adhesive composition are not sufficient, which is not preferable.

The physical properties of component (B) are other than those of component (S'_NMR/S_NMR) The other components are not particularly limited. The softening point of the component (B) is preferably from about 60 to about 160 ℃ from the viewpoint of high adhesion to polyolefin, high holding power, and excellent adhesion to curved surfaces.

The weight average molecular weight of the component (B) is preferably from about 500 to about 4000 from the viewpoint of excellent compatibility with the base polymer. The weight average molecular weight of the component (B) is more preferably from about 500 to about 3500 from the viewpoint of not only excellent compatibility but also improved holding power, and is still more preferably from about 500 to about 2500 from the viewpoint of not only excellent compatibility and holding power but also excellent curved surface adhesiveness. In the present specification, the weight average molecular weight refers to a polystyrene equivalent value in a Gel Permeation Chromatography (GPC) method.

(A) The mass ratio of the component (a) to the component (B) ((a)/(B)) is not particularly limited, and is preferably 60/40 to 99/1 in terms of solid content, from the viewpoint of excellent compatibility with the base polymer. Further, from the viewpoint of not only excellent compatibility but also improved holding power, (a)/(B) is more preferably 70/30 to 95/5, and further more preferably 80/20 to 90/10 from the viewpoint of not only excellent compatibility and holding power but also excellent curved surface adhesiveness.

< emulsifier (C) >

(C) The component (b) is not particularly limited, and various known emulsifiers can be used. Specific examples thereof include high molecular weight emulsifiers, low molecular weight anionic emulsifiers, and low molecular weight nonionic emulsifiers obtained by polymerizing monomers. These may be used alone or in combination of two or more.

Examples of the monomer used for producing the high molecular weight emulsifier include: (meth) acrylate monomers such as methyl (meth) acrylate and ethyl (meth) acrylate; monocarboxylic acid-based vinyl monomers such as (meth) acrylic acid and crotonic acid; dicarboxylic acid-based vinyl monomers such as maleic acid and maleic anhydride; sulfonic acid vinyl monomers such as vinylsulfonic acid and styrenesulfonic acid; and alkali metal salts, alkaline earth metal salts, ammonium salts, salts of organic bases of the above-mentioned various organic acids; (meth) acrylamide monomers such as (meth) acrylamide and N-methylol (meth) acrylamide; nitrile monomers such as (meth) acrylonitrile; vinyl ester monomers such as vinyl acetate; hydroxyl group-containing (meth) acrylate monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; methyl vinyl ether, glycidyl (meth) acrylate, urethane acrylate, an alpha-olefin having 6 to 22 carbon atoms, vinyl pyrrolidone, and other monomers. These may be used alone or in combination of two or more.

Examples of the polymerization method include solution polymerization, suspension polymerization, and emulsion polymerization using a reactive emulsifier other than a high-molecular-weight emulsifier, a non-reactive emulsifier other than a high-molecular-weight emulsifier, and the like, which will be described later.

The weight average molecular weight of the high molecular weight emulsifier thus obtained is not particularly limited, but is preferably usually set to about 1000 to about 500000 in terms of the adhesive properties of the tackifier resin emulsion obtained. The weight average molecular weight as used herein refers to a polystyrene equivalent value in a Gel Permeation Chromatography (GPC) method.

The reactive emulsifier other than the high-molecular-weight emulsifier is, for example, a reactive emulsifier having a hydrophilic group such as a sulfonic acid group or a carboxyl group and a hydrophobic group such as an alkyl group or a phenyl group, and means a reactive emulsifier having a carbon-carbon double bond in the molecule.

Examples of the low-molecular-weight anionic emulsifier include dialkyl sulfosuccinate salts, alkane sulfonates, α -olefin sulfonates, polyoxyethylene alkyl ether sulfosuccinate salts, polyoxyethylene styryl phenyl ether sulfosuccinate salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl ether sulfate salts, polyoxyethylene dialkyl ether sulfate salts, polyoxyethylene trialkyl ether sulfate salts, and polyoxyethylene alkyl phenyl ether sulfate salts. These may be used alone or in combination of two or more.

Examples of the low-molecular weight nonionic emulsifier include polyoxyethylene alkyl ethers, polyoxyethylene styrylphenyl ethers, and polyoxyethylene sorbitan fatty acid esters. These may be used alone or in combination of two or more.

(C) The amount of the component (B) is not particularly limited, and is preferably from about 1 to about 20 parts by mass, and more preferably from about 2 to about 10 parts by mass, in terms of solid content, based on 100 parts by mass of the total of the components (a) and (B), from the viewpoint of excellent emulsifiability.

The tackifier resin emulsion of the present invention may contain, if necessary, a defoaming agent, a thickener, a filler, an antioxidant, a water resistant agent, a film forming aid, a pH adjuster such as ammonia water or sodium hydrogen carbonate, and the like, as long as desired characteristics are not impaired.

The tackifier resin emulsion of the present invention can be obtained by emulsifying the component (a) and the component (B) in the presence of the component (C) (hereinafter, also referred to as "emulsifier") and mixing the obtained emulsions, or emulsifying the component (a) and the component (B) together. The emulsification method is not particularly limited, and a known emulsification method such as a high-pressure emulsification method and a phase inversion emulsification method can be used.

The high-pressure emulsification method is as follows: after the component (a) and/or the component (B) are brought into a molten state, an emulsifier and water are premixed, and a microemulsion is carried out using a high-pressure emulsifier, and then, the solvent is removed as necessary. The emulsified material may be heated alone, or may be dissolved in a solvent and then heated, or may be mixed with a nonvolatile material such as a plasticizer and heated, and preferably heated alone. Examples of the solvent include organic solvents capable of dissolving the emulsified material, such as toluene, xylene, methylcyclohexane, and ethyl acetate.

The phase inversion emulsification method is as follows: after the component (A) and/or the component (B) are heated and melted, an emulsifier and water are added while stirring to form a W/O emulsion, and then the mixture is phase-inverted into an O/W emulsion by adding water, changing the temperature, and the like.

The concentration of the tackifier resin emulsion thus obtained is not particularly limited, and is usually appropriately adjusted so that the solid content is about 20% by mass to about 70% by mass. The volume average particle diameter of the tackifier resin emulsion obtained is usually about 0.1 μm to about 2 μm. The tackifier resin emulsion is mostly uniformly dispersed in the form of particles of 1 μm or less, but from the viewpoint of storage stability, it is preferable that the volume average particle diameter thereof is 0.7 μm or less. The obtained tackifier resin emulsion has a white or milky appearance, and the viscosity is usually about 10 mPas to about 1000 mPas (temperature 25 ℃ C., concentration 50% by mass).

The pH of the tackifier resin emulsion obtained by the above method is usually about 2 to about 10. Further, as necessary, an inorganic acid such as hydrochloric acid, sulfuric acid, or phosphoric acid may be added to the tackifier resin emulsion as appropriate; alkanolamines such as monomethylamine, monoethanolamine, diethanolamine, and diisopropanolamine; aliphatic amines such as ethylamine, n-butylamine, and triethylamine; alkali metal hydroxides such as potassium hydroxide and sodium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide, etc. to adjust the pH.

[ Water-based adhesive and/or cohesive agent composition ]

The water-based adhesive and/or cohesive composition of the present invention comprises the tackifying resin emulsion of the present invention and a base polymer. The water-based adhesive and/or cohesive agent composition of the present invention can be used as a water-based adhesive and/or cohesive agent. It should be noted that in the present specification, "bonding and/or adhesive" obviously includes either or both of a bonding agent and an adhesive.

The base polymer may be an acrylic polymer emulsion, a rubber latex, a synthetic resin emulsion, or the like, and these may be used in combination, and further, if necessary, a crosslinking agent, a defoaming agent, a thickener, a filler, an antioxidant, a water resistant agent, a film forming aid, a pH adjuster such as ammonia water or sodium hydrogen carbonate, or the like may be used. In addition, a known tackifier resin emulsion may be further used. The concentration of the water-based adhesive and/or cohesive composition is usually about 40 to 70% by mass, preferably 55 to 70% by mass, in terms of solid content.

The acrylic polymer emulsion can be an emulsion generally used for various acrylic adhesives and/or pressure sensitive adhesives, and can be easily produced by a known emulsion polymerization method such as a one-shot polymerization method of a monomer such as a (meth) acrylate ester, a sequential monomer addition polymerization method, a sequential emulsified monomer addition polymerization method, or a seed polymerization method.

Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate, and two or more of these may be used alone or in combination. In addition, in order to impart storage stability to the obtained emulsion, (meth) acrylic acid may be used instead of a part of the above (meth) acrylic acid ester. In addition, copolymerizable monomers such as vinyl acetate, styrene and the like may also be used in combination to such an extent as not to impair the adhesive properties of the (meth) acrylate polymer, as desired. As the emulsifier used in the acrylic polymer emulsion, an anionic emulsifier, a partially saponified polyvinyl alcohol, or the like can be used, and the amount thereof used is about 0.1 to about 5 parts by mass, preferably about 0.5 to about 3 parts by mass, in terms of solid content, relative to 100 parts by mass of the (meth) acrylate polymer.

The content ratio of the acrylic polymer emulsion and the tackifier resin emulsion is not particularly limited, and the tackifier resin emulsion may be usually set to about 2 parts by mass to about 40 parts by mass based on 100 parts by mass of the acrylic polymer emulsion in terms of solid content as an appropriate range in which the effect of modification by the tackifier resin emulsion can be sufficiently exhibited and the heat-resistant holding power, viscosity, and the like are not reduced by excessive use.

As the rubber latex, various known rubber latexes used in aqueous adhesive and/or pressure-sensitive adhesive compositions can be used. Examples thereof include natural rubber latex, styrene-butadiene copolymer latex, and chloroprene latex.

The content ratio of the rubber latex and the tackifier resin emulsion is not particularly limited, and the tackifier resin emulsion may be usually set to about 10 parts by mass to about 150 parts by mass in terms of solid content per 100 parts by mass of the rubber latex as an appropriate range in which the modification effect by the tackifier resin emulsion can be sufficiently exhibited and the reduction in adhesive strength, viscosity, and the like due to excessive use is not caused.

As the synthetic resin emulsion, various known synthetic resin emulsions used in aqueous adhesive and/or pressure-sensitive adhesive compositions can be used, and examples thereof include synthetic resin emulsions such as vinyl acetate emulsions, ethylene-vinyl acetate copolymer emulsions, and urethane emulsions.

The content ratio of the synthetic resin emulsion to the tackifier resin emulsion is not particularly limited, and the tackifier resin emulsion may be usually set to about 2 parts by mass to about 40 parts by mass in terms of solid content based on 100 parts by mass of the synthetic resin emulsion as an appropriate use ratio that can sufficiently exhibit the effect of modifying the tackifier resin emulsion and does not cause a decrease in adhesive strength, viscosity, and the like due to excessive use.

The aqueous adhesive and/or cohesive agent composition of the present invention is obtained by mixing the tackifier resin emulsion with the base polymer. The mixing method is not particularly limited, and various known methods can be used.

[ adhesive and/or tacky sheet ]

The adhesive and/or pressure-sensitive adhesive sheet of the present invention comprises an adhesive and/or pressure-sensitive adhesive layer comprising the above-mentioned water-based adhesive and/or pressure-sensitive adhesive composition, and a base material. The pressure-sensitive adhesive sheet of the present invention may be a pressure-sensitive adhesive sheet with a substrate having a pressure-sensitive adhesive layer on one or both sides of the substrate, or may be a pressure-sensitive adhesive sheet without a substrate, such as a pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer is held on a release liner (also referred to as a substrate having a release surface). The concept of the adhesive and/or cohesive sheet described herein may include materials referred to as adhesive and/or cohesive tapes, adhesive and/or cohesive labels, adhesive and/or cohesive films, and the like.

As the substrate, for example: plastic films such as polyolefin (polyethylene, polypropylene, ethylene-propylene copolymer, etc.) films, polyester (polyethylene terephthalate, etc.) films, vinyl chloride resin films, vinyl acetate resin films, polyimide resin films, polyamide resin films, fluorine resin films, and other cellophanes; papers such as japanese paper, kraft paper, cellophane paper, high-quality paper, synthetic paper, and coated paper; fabrics such as woven and nonwoven fabrics obtained from various fibrous materials alone or in combination; rubber sheets made of natural rubber, butyl rubber, or the like; foamed sheets made of foamed polyurethane, foamed polychloroprene rubber, or the like; metal foils such as aluminum foil and copper foil; a complex thereof; and the like.

The adhesive and/or cohesive sheet of the present invention can be manufactured by a known method. First, the aqueous pressure-sensitive adhesive and/or adhesive composition is applied to one or both surfaces of a substrate to form a coating layer made of the aqueous pressure-sensitive adhesive and/or adhesive composition. As the coating method, a known method can be used, and roll coating, comma coating, die coating, reverse coating, screen printing, gravure coating, and the like can be mentioned. Next, the coating layer is heated or dried to form an adhesive layer composed of the aqueous adhesive and/or pressure-sensitive adhesive composition. The conditions for heating or drying may be set appropriately according to the thickness of the adhesive layer and/or the adhesive layer, and the temperature is, for example, 10 to 120 ℃ and the time is, for example, 0.1 to 10 hours. The thickness of the adhesive layer (dried thickness) varies depending on the application, and is preferably 5 to 200 μm.

The bonding and/or adhesive sheet of the present invention comprises a bonding and/or adhesive layer comprising the above-mentioned aqueous bonding and/or adhesive composition, and therefore, is excellent in curved surface adhesiveness and is suitable for use as a bonding and/or adhesive sheet for bonding to a curved surface of a polyolefin resin, for example, as a building material, an automobile interior member, a film label, or the like. Further, the pressure-sensitive adhesive sheet of the present invention is excellent in transparency, and therefore, is suitable as a pressure-sensitive adhesive sheet for applications requiring transparency or design property, for example, a transparent label used for a cosmetic container or a shampoo container.