Water-dispersed composition, tackifying resin water-dispersed composition, pressure-sensitive adhesive / adhesive composition, and pressure-sensitive adhesive sheet / adhesive sheet

Abstract

[Technical Problem] Provide a water-dispersible composition comprising a novel rosin-based resin with excellent emulsification properties. [Technical Solution] Provide a water-dispersible composition comprising a rosin-based resin (A) having a weight-average molecular weight of 1,600 to 3,000 and an emulsifier (B), wherein the content of components having a weight-average molecular weight of 6,000 or greater in the rosin-based resin (A) is less than 10% by mass.

Description

Technical Field

[0001] The present invention relates to a water-dispersed composition, a tackifying resin water-dispersed composition, an aqueous pressure-sensitive adhesive composition / aqueous adhesive composition (aqueous adhesive / bonding agent composition), and a pressure-sensitive adhesive sheet / adhesive sheet. Background Art

[0002] Rosin resins are widely used in a variety of fields, including as tackifiers for pressure-sensitive adhesives / adhesives such as hot melt adhesives and pressure-sensitive adhesives, modifiers for rubber and plastics, emulsifiers for synthetic rubber, base materials for chewing gum, binder resins for road marking paints and inks, and sizing agents for papermaking. These rosin resins were previously typically dissolved in organic solvents, but in recent years, aqueous dispersions dispersed or emulsified in water have become the mainstream for environmental, health, and resource conservation considerations.

[0003] As aqueous dispersion compositions of rosin-based resins, compositions emulsified in the presence of various anionic emulsifiers and nonionic emulsifiers have been proposed (see Patent Documents 1 and 2). However, some of these aqueous dispersion compositions generate a large amount of aggregates, and their emulsification properties are still insufficient.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-106259

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 11-61087 Summary of the Invention

[0008] Technical problem to be solved by the invention

[0009] An object of the present invention is to provide an aqueous dispersion composition containing a novel rosin-based resin having excellent emulsification properties.

[0010] Technical means to solve technical problems

[0011] The inventors of the present invention have conducted intensive research and have discovered that the aforementioned problems can be solved by an aqueous dispersion composition containing a specific rosin-based resin. Specifically, the present invention relates to the following aqueous dispersion composition, aqueous dispersion composition containing a tackifying resin, aqueous pressure-sensitive adhesive composition / aqueous adhesive composition, and pressure-sensitive adhesive sheet / adhesive sheet:

[0012] 1. A water-dispersible composition comprising a rosin-based resin (A) having a weight-average molecular weight of 1,600 to 3,000 and an emulsifier (B), wherein the content of components having a weight-average molecular weight of 6,000 or more in the rosin-based resin (A) is less than 10% by mass.

[0013] 2. The water-dispersible composition according to the above item 1, wherein the component (A) is a rosin ester.

[0014] 3. A tackifying resin aqueous dispersion composition comprising the aqueous dispersion composition according to item 1 or 2 above.

[0015] 4. A water-based pressure-sensitive adhesive composition or a water-based adhesive composition comprising the water-dispersed composition according to the above item 1 or 2 and a base polymer.

[0016] 5. The water-based pressure-sensitive adhesive composition / water-based adhesive composition according to the above item 4, wherein the base polymer is an acrylic polymer emulsion.

[0017] 6. A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer comprising the aqueous pressure-sensitive adhesive composition according to item 4 or 5 above, and a substrate.

[0018] Beneficial effects

[0019] The aqueous dispersion composition of the present invention suppresses the formation of aggregates, has a small particle size, and exhibits excellent emulsification properties. Furthermore, the aqueous dispersion composition of the present invention can impart excellent adhesion to aqueous pressure-sensitive adhesive compositions / aqueous adhesive compositions containing the composition. Furthermore, the aqueous dispersion composition of the present invention exhibits excellent storage stability. DETAILED DESCRIPTION

[0020] [Water-dispersible composition]

[0021] The water-dispersible composition of the present invention comprises a rosin-based resin (A) having a weight-average molecular weight of 1,600 to 3,000 and containing less than 10% by mass of a component having a weight-average molecular weight of 6,000 or more (hereinafter referred to as component (A)) and an emulsifier (B) (hereinafter referred to as component (B)).

[0022] <Rosin-based resin (A)>

[0023] There are no particular limitations on the composition of component (A), and various known rosin-based resins can be used, as long as the component (A) has a weight-average molecular weight of 1,600 to 3,000 and the content of components having a weight-average molecular weight of 6,000 or greater is less than 10% by mass. Component (A) can be used alone or in combination of two or more.

[0024] When the weight-average molecular weight of component (A) is 1,600 or more, the emulsification property in the aqueous dispersion composition is excellent, and the aqueous pressure-sensitive adhesive composition / aqueous adhesive composition containing the same has excellent adhesion. When the weight-average molecular weight of component (A) is 3,000 or less, the emulsification property in the aqueous dispersion composition is excellent. From the perspective of excellent adhesion and emulsification, the weight-average molecular weight of component (A) is preferably about 1,800 to 2,500. In addition, in this specification, the weight-average molecular weight is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC).

[0025] When the content of the component having a weight average molecular weight of 6,000 or more of the component (A) is less than 10% by mass, the emulsification in the water-dispersed composition is excellent, and the adhesion in the aqueous pressure-sensitive adhesive composition / aqueous adhesive composition containing it is excellent. From the viewpoint of excellent adhesion and emulsification, the content of the component having a weight average molecular weight of 6,000 or more of the component (A) is preferably less, preferably about 0% to 8% by mass. In addition, in this specification, the content (% by mass) of the component having a weight average molecular weight of 6,000 or more in the component (A) is obtained by the ratio ((S2) / (S1)) of the total peak area value (S2) of the component having a weight average molecular weight of 6,000 or more measured by gel permeation chromatography (GPC) to the total peak area value (S1) of the component (A).

[0026] Examples of the component (A) include natural rosins (gum rosin, tall oil rosin, wood rosin) derived from species such as Masson pine (Pinus massoniana), Elliot pine (Pinus elliottii), South Asian pine (Pinus merkusii), Caribbean pine (Pinus caribaea), Simao pine (Pinus kesiya), Loblolly pine (Pinus taeda), and King pine (Pinus palustris); refined rosin (hereinafter referred to as unmodified rosin); hydrogenated rosin; disproportionated rosin; polymerized rosin; α,β-unsaturated carboxylic acid-modified rosin; and esters thereof (hereinafter also referred to as rosin esters); and rosin phenolic resin.

[0027] The purified rosin can be obtained using various known methods. Specifically, it can be obtained using various known purification methods, such as distillation, extraction, recrystallization, and adsorption. Examples of distillation methods include distilling the natural rosin at a temperature of approximately 200°C to 300°C and a reduced pressure of approximately 0.01 kPa to 3 kPa. Examples of extraction methods include preparing the natural rosin into an alkaline aqueous solution, extracting the insoluble unsaponifiable matter with various organic solvents, and then neutralizing the aqueous layer. Examples of recrystallization methods include dissolving the natural rosin in an organic solvent serving as a good solvent, then distilling off the solvent to form a concentrated solution, and then adding an organic solvent serving as a poor solvent. Examples of good solvents include aromatic hydrocarbon solvents such as benzene, toluene, and xylene; chlorinated hydrocarbon solvents such as chloroform; lower alcohols; ketones such as acetone; and acetates such as ethyl acetate. Examples of poor solvents include n-hexane, n-heptane, cyclohexane, and isooctane. Examples of the adsorption method include a method in which a molten unmodified rosin or a solution of unmodified rosin in an organic solvent is brought into contact with a porous adsorbent. Examples of the porous adsorbent include activated carbon, metal oxides (e.g., alumina, zirconia), silica, molecular sieves, zeolites, and microporous clays.

[0028] The above-mentioned disproportionated rosin can be obtained using various well-known methods. Specifically, for example, it can be obtained by a method (disproportionation) of heating the above-mentioned unmodified rosin in the presence of a disproportionation catalyst. As a disproportionation catalyst, the following various well-known substances can be used: supported catalysts such as palladium-carbon, rhodium-carbon, platinum-carbon; metal powders such as nickel and platinum; iodides such as iodine and iron iodide. The amount of the catalyst used is generally about 0.01 to 5 parts by mass, preferably about 0.01 to 1 part by mass, relative to 100 parts by mass of unmodified rosin. The reaction temperature is about 100°C to 300°C, preferably about 150°C to 290°C.

[0029] Furthermore, as the disproportionated rosin, a disproportionated rosin subjected to the above-mentioned purification may be used.

[0030] The hydrogenated rosin can be obtained using various known methods. Specifically, for example, it can be obtained by hydrogenating the unmodified rosin using known hydrogenation conditions. Examples of hydrogenation conditions include heating the unmodified rosin at a hydrogen pressure of about 2 MPa to 20 MPa and a temperature of about 100°C to 300°C in the presence of a hydrogenation catalyst. In addition, preferably, the hydrogen pressure is about 5 MPa to 20 MPa and the reaction temperature is about 150°C to 300°C. As the hydrogenation catalyst, various known substances such as supported catalysts and metal powders can be used. Examples of supported catalysts include palladium-carbon, rhodium-carbon, ruthenium-carbon, platinum-carbon, etc. Examples of metal powders include nickel and platinum. Among them, palladium, rhodium, ruthenium and platinum catalysts are preferred because the hydrogenation rate of the unmodified rosin becomes higher and the hydrogenation time becomes shorter. The amount of the hydrogenation catalyst used is generally about 0.01 to 5 parts by mass, preferably about 0.01 to 2 parts by mass, relative to 100 parts by mass of the unmodified rosin.

[0031] The hydrogenation can be carried out, if necessary, while dissolving the unmodified rosin in a solvent. The solvent used is not particularly limited, as long as it is inert to the reaction and readily dissolves the raw materials and products. Specifically, for example, one or a combination of two or more of cyclohexane, n-hexane, n-heptane, decalin, tetrahydrofuran, and dioxane can be used. The amount of solvent used is not particularly limited; generally, it can be used at a solids content of 10% by mass or more, preferably in the range of 10% to 70% by mass, relative to the unmodified rosin.

[0032] Furthermore, as the hydrogenated rosin, hydrogenated rosin subjected to the above-mentioned purification may be used.

[0033] The polymerized rosin can be obtained using various known methods. Specifically, for example, a method in which the unmodified rosin as a raw material is reacted in a solvent such as toluene or xylene containing a catalyst such as sulfuric acid, hydrogen fluoride, aluminum chloride, or titanium tetrachloride at a reaction temperature of approximately 40°C to 160°C for approximately 1 to 5 hours is exemplified.

[0034] Specific examples of polymerized rosins include gum-based polymerized rosins using gum rosin as a raw material (for example, the trade name "Polymerized Rosin B-140", manufactured by Xinzhou (Wuping) Forest Chemical Co., Ltd.), tall oil-based polymerized rosins using tall oil rosin (for example, the trade name "Silbatak 140", manufactured by Arizon Chemicar Co., Ltd.), and wood-based polymerized rosins using wood rosin (for example, the trade name "Dimarex", manufactured by Isterman Chemicar Co., Ltd.).

[0035] Alternatively, the polymerized rosin may be a polymerized rosin subjected to various treatments, including the aforementioned purification, hydrogenation, and disproportionation, as well as α,β-unsaturated carboxylic acid modification such as acrylic acidization, maleic acidization, and fumaric acidization, as described later. Each of these treatments may be performed alone or in combination of two or more.

[0036] The α,β-unsaturated carboxylic acid-modified rosin is obtained by subjecting the α,β-unsaturated carboxylic acid to an addition reaction with the unmodified rosin.

[0037] The α,β-unsaturated carboxylic acid is not particularly limited, and various known substances can be used. Specific examples include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, muconic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, muconic anhydride, maleic acid half esters, fumaric acid half esters, and itaconic acid half esters. Among these, maleic acid, maleic anhydride, and fumaric acid are preferred. From the perspective of emulsification, the amount of the α,β-unsaturated carboxylic acid used is generally about 1 to 20 parts by mass, preferably about 1 to 3 parts by mass, relative to 100 parts by mass of the unmodified rosin.

[0038] The above-mentioned α,β-unsaturated carboxylic acid-modified rosin can be obtained using various well-known methods. Specifically, for example, the above-mentioned α,β-unsaturated carboxylic acid is added to the above-mentioned unmodified rosin melted under heating, and the reaction is carried out at a temperature of about 180°C to 240°C for about 1 hour to 9 hours. In addition, the above-mentioned reaction can also be carried out while blowing an inert gas such as nitrogen into a closed reaction system. Furthermore, in the reaction, for example, known catalysts such as Lewis acids such as zinc chloride, ferric chloride, and tin chloride and Bronsted acids such as p-toluenesulfonic acid and methanesulfonic acid can also be used. The amount of these catalysts used is generally about 0.01% by mass to 10% by mass relative to the above-mentioned unmodified rosin.

[0039] The obtained α,β-unsaturated carboxylic acid-modified rosin may contain resin acid derived from the unmodified rosin, with the content being less than 10% by mass.

[0040] (Rosin Esters)

[0041] Examples of the rosin esters include reaction products of the above-mentioned unmodified rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, and α,β-unsaturated carboxylic acid-modified rosin (hereinafter collectively referred to as rosins) with alcohols. In this specification, esters of unmodified rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, and α,β-unsaturated carboxylic acid-modified rosin are referred to as unmodified rosin esters, hydrogenated rosin esters, disproportionated rosin esters, polymerized rosin esters, and α,β-unsaturated carboxylic acid-modified rosin esters, respectively.

[0042] The alcohol is not particularly limited, and various known alcohols can be used. Examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-octanol, 2-ethylhexanol, decanol, lauryl alcohol, cyclohexanol, benzyl alcohol, borneol and other monohydric alcohols; ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, neopentyl glycol, trimethylene glycol, cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4'-isopropylidene dicyclohexanol, 4,8-bis(hydroxymethyl)tricyclo[5.2.1.0 2,6 ] diols such as decane; triols such as glycerol, trimethylolethane, and trimethylolpropane; tetraols such as pentaerythritol, diglycerol, and di(trimethylolpropane); pentaols such as triglycerol; hexaols such as dipentaerythritol, etc. Furthermore, glycidyl ethers and glycidol that react with carboxylic acids to form esters may also be used. These alcohols may be used alone or in combination of two or more.

[0043] From the viewpoint of excellent adhesive strength, the alcohol is preferably a trivalent to hexavalent alcohol, and more preferably glycerol, pentaerythritol, diglycerol, and dipentaerythritol.

[0044] The rosin esters can be obtained using various known methods. Specifically, for example, the rosins can be reacted with the alcohols at a temperature of approximately 150°C to 300°C for approximately 1 to 24 hours. The amounts of the rosins and alcohols used are not particularly limited, but the equivalent ratio of OH groups of the alcohol to COOH groups of the rosin is typically set within a range of approximately 0.8 to 8, preferably approximately 1.1 to 1.3.

[0045] In the above-mentioned method for producing rosin esters, the esterification reaction can be carried out in the presence of a catalyst to shorten the reaction time. Examples of catalysts include acid catalysts such as p-toluenesulfonic acid, acetic acid, methanesulfonic acid, hypophosphorous acid, and sulfuric acid; metal hydroxides such as calcium hydroxide and magnesium hydroxide; metal oxides such as calcium oxide and magnesium oxide; and metal salts such as ferric chloride and calcium formate. A single catalyst may be used alone, or two or more may be used in combination. Furthermore, since the esterification reaction produces water, the reaction can be carried out while removing the generated water from the system. Considering the color tone of the resulting rosin ester, it is desirable to carry out the reaction under a stream of inert gas. Furthermore, the reaction can be carried out under pressure, if desired.

[0046] In the above-mentioned method for producing rosin esters, the reaction can be carried out in an organic solvent that is non-reactive with the rosin and alcohol. Examples of such organic solvents include hexane, cyclohexane, toluene, and xylene. When an organic solvent is used, the organic solvent and unreacted raw materials can be removed by distillation under reduced pressure as needed.

[0047] In the above-mentioned method for producing rosin esters, the obtained rosin esters may be further subjected to various treatments such as the above-mentioned purification, hydrogenation, disproportionation, and α,β-unsaturated carboxylic acid modification. The various treatments may be performed alone or in combination of two or more.

[0048] In the method for producing polymerized rosin ester and α,β-unsaturated carboxylic acid-modified rosin ester, it is preferred to further react the polymerized rosin, α,β-unsaturated carboxylic acid-modified rosin, and the above-mentioned alcohol with unmodified rosin from the viewpoint of reducing the content of components having a weight-average molecular weight of 6,000 or more.

[0049] Alternatively, the production methods of hydrogenated rosin ester, disproportionated rosin ester, polymerized rosin ester, and α,β-unsaturated carboxylic acid-modified rosin ester may be methods in which the reaction product of the unmodified rosin and the alcohol is subjected to hydrogenation, disproportionation, polymerization, and modification with an α,β-unsaturated carboxylic acid.

[0050] (rosin phenolic resin)

[0051] The rosin phenolic resin is obtained by reacting phenols with the unmodified rosin.

[0052] The phenols are not particularly limited, and various known compounds can be used. Specifically, examples include alkylphenols such as methylphenol, butylphenol, octylphenol, and nonylphenol; phenol, bisphenols; and naphthols. These can be used alone or in combination. From the perspective of emulsification, the phenols are typically used in an amount of approximately 0.8 to 1.5 moles per mole of the rosin raw material.

[0053] The method for producing the above-mentioned rosin phenolic resin is not particularly limited. For example, a method in which the above-mentioned unmodified rosin and phenols are heated in the presence of an acid catalyst as needed to react them is exemplified. As the reaction temperature, it is usually allowed to react for about 6 to 18 hours at 180°C to 350°C. In addition, the acid catalyst that can be used in this reaction is not particularly limited. For example, inorganic acid catalysts such as sulfuric acid, hydrogen chloride, and boron trifluoride and organic acid catalysts such as p-toluenesulfonic acid and methanesulfonic acid can be exemplified. When an acid catalyst is used, about 0.01 to 1.0 parts by mass can be used relative to 100 parts by mass of the above-mentioned unmodified rosin. In addition, the rosin phenolic resin can also be a resin obtained by further reacting the resin obtained in the above-mentioned reaction with an alcohol to esterify it. The alcohol used at this time is the same as described above.

[0054] From the viewpoint of excellent emulsification and adhesive strength, component (A) is preferably a rosin ester. From the same viewpoint, at least one selected from the group consisting of polymerized rosin esters and α,β-unsaturated carboxylic acid-modified rosin esters is more preferred. From the same viewpoint, polymerized rosin esters are particularly preferred.

[0055] Component (A) may contain various additives as long as they do not impair the effects of the present invention. Examples of such additives include dehydrating agents, crystallization nucleating agents, plasticizers, flow improvers, weathering agents, antioxidants, ultraviolet absorbers, heat stabilizers, and light stabilizers. Such additives may be used alone or in combination of two or more.

[0056] Examples of the antioxidant include sulfur-based antioxidants, thiophosphite-based antioxidants, phosphorus-based antioxidants, and hindered phenol-based antioxidants.

[0057] Examples of the antioxidant include Irganox (registered trademark) 565 and the like.

[0058] (Physical Properties of Rosin-Based Resin (A))

[0059] The physical properties of component (A) are not particularly limited except for the weight-average molecular weight. From the perspective of excellent emulsification and adhesion, the hydroxyl value of component (A) is preferably approximately 20 mgKOH / g to 50 mgKOH / g. Furthermore, from the perspective of excellent emulsification and adhesion, the acid value of component (A) is preferably approximately 1 mgKOH / g to 20 mgKOH / g; from the same perspective, it is more preferably approximately 5 mgKOH / g to 9 mgKOH / g. In the present invention, the hydroxyl value and acid value are values measured in accordance with JIS K0070.

[0060] <Emulsifier (B)>

[0061] Component (B) is not particularly limited, and various known emulsifiers can be used. Specifically, high molecular weight emulsifiers obtained by polymerizing monomers, low molecular weight anionic emulsifiers, low molecular weight nonionic emulsifiers, etc. Component (B) can be used alone or in combination of two or more.

[0062] Examples of monomers used in the production of the high molecular weight emulsifier include (meth)acrylate monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and polyoxyalkylene (meth)acrylate; monocarboxylic acid vinyl monomers such as (meth)acrylic acid and crotonic acid; dicarboxylic acid vinyl monomers such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, and muconic acid; sulfonic acid vinyl monomers such as vinyl sulfonic acid, styrenesulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid; 2-(meth)acryloyloxy Phosphate-based vinyl monomers such as ethyl acid phosphate and diphenyl-2(meth)acryloyloxy phosphate; alkali metal salts, alkaline earth metal salts, ammonium salts, and organic base salts of these various organic acids; (meth)acrylamide monomers such as (meth)acrylamide and N-hydroxymethyl (meth)acrylamide; nitrile monomers such as (meth)acrylonitrile; vinyl ester monomers such as vinyl acetate; hydroxyl-containing (meth)acrylate monomers such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; styrenes such as styrene, α-methylstyrene, and vinyltoluene; and other monomers such as methyl vinyl ether, glycidyl (meth)acrylate, urethane acrylate, α-olefins having 6 to 22 carbon atoms, and vinyl pyrrolidone. These monomers may be used alone or in combination of two or more.

[0063] From the viewpoint of polymerizability and emulsification of the resulting high molecular weight emulsifier, the monomers used in the production of the high molecular weight emulsifier are preferably methyl (meth)acrylate, alkali metal salts of sulfonic acid vinyl monomers, and styrenes.

[0064] Examples of polymerization methods for the high molecular weight emulsifier include solution polymerization, suspension polymerization, and emulsion polymerization using a reactive emulsifier other than the high molecular weight emulsifier described below, or a non-reactive emulsifier other than the high molecular weight emulsifier. Examples of the non-reactive emulsifier include the low molecular weight anionic emulsifiers and low molecular weight nonionic emulsifiers described below.

[0065] The weight average molecular weight of the high molecular weight emulsifier is not particularly limited, but is generally preferably about 1,000 to 500,000 from the viewpoint of the adhesive properties of the resulting aqueous dispersion composition. In this specification, the weight average molecular weight refers to the polyoxyethylene equivalent value obtained by gel permeation chromatography (GPC).

[0066] Examples of reactive emulsifiers other than the above-mentioned high molecular weight emulsifiers include emulsifiers 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 having a carbon-carbon double bond in the molecule. Examples of the carbon-carbon double bond include functional groups such as (meth)allyl, 1-propenyl, 2-methyl-1-propenyl, vinyl, isopropenyl, and (meth)acryloyl.

[0067] Examples of the reactive emulsifier include polyoxyethylene alkyl ethers having at least one of the aforementioned functional groups in the molecule, polyoxyethylene phenyl ethers having at least one of the aforementioned functional groups in the molecule, and their sulfosuccinates and sulfates. Furthermore, examples include polyoxyethylene alkyl phenyl ethers having at least one of the aforementioned functional groups in the molecule, their sulfosuccinates, sulfates, phosphates, and aliphatic or aromatic carboxylates. Furthermore, examples include acidic phosphoric acid (meth)acrylate emulsifiers, anhydride-modified products of rosin glycidyl acrylate (see JP-A-4-256429), and emulsifiers described in JP-A-63-23725, JP-A-63-240931, and JP-A-62-104802. Furthermore, there can be mentioned emulsifiers in which the polyoxyethylene in the above-mentioned reactive emulsifier is replaced with polyoxypropylene, or emulsifiers in which polyoxyethylene and polyoxypropylene are block copolymerized or randomly copolymerized.

[0068] Examples of commercially available products of the reactive emulsifier include "KAYAMER PM-1", "KAYAMER PM-2", and "KAYAMER PM-21" (the above are manufactured by Nippon Kayaku Co., Ltd.), "SE-10N", "NE-10", "NE-20", "NE-30", "アデカリアソープSR-10", "アデカリアソー"プSR-20", "アデカリアソープER-20" (the above are manufactured by ADEKA Co., Ltd.), "ニューフロンティアA229E", "ニューフロンティアN117E", "ニューフロ"ンティアN250Z", "アクアロンRN-10", "アクアロンRN-20", "ア"クアロンRN-50", "アクアロンHS-10", "アクアロンKH-05", "アクTypical examples include "Econon KH-10" (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), "Economicon JS-2" (manufactured by Sanyo Chemical Industry Co., Ltd.), and "Lateral K-180" (manufactured by Kao Co., Ltd.).

[0069] From the viewpoint of polymerizability and emulsification of the resulting high molecular weight emulsifier, the reactive emulsifier is preferably polyoxyethylene alkyl ethers or polyoxyethylene phenyl ethers.

[0070] Examples of the low molecular weight anionic emulsifier include dialkyl sulfosuccinate salts, alkane sulfonates, α-olefin sulfonates, polyoxyethylene alkyl sulfosuccinate salts, polyoxyethylene alkyl ether sulfosuccinate salts, polyoxyethylene styrylphenyl ether sulfosuccinate salts, naphthalenesulfonic acid formalin condensate, polyoxyethylene alkyl ether sulfate salts, polyoxyethylene dialkyl ether sulfate salts, polyoxyethylene trialkyl ether sulfate salts, and polyoxyethylene alkylphenyl ether sulfate salts. These may be used alone or in combination of two or more.

[0071] Examples of the low molecular weight nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene sorbitan fatty acid ester, etc. These may be used alone or in combination of two or more.

[0072] The amount of component (B) used is not particularly limited. However, from the viewpoint of excellent emulsification, the amount is preferably about 1 to 20 parts by mass, more preferably about 2 to 10 parts by mass, based on solid content, per 100 parts by mass of component (A).

[0073] The aqueous dispersion composition of the present invention may contain a crosslinking agent, a defoaming agent, a thickener, a filler, an ultraviolet absorber, a light stabilizer, an antioxidant, a water resistance agent, a film-forming aid, a preservative, a pH adjuster such as aqueous ammonia and sodium bicarbonate, etc., as necessary, unless the desired properties are impaired.

[0074] Examples of the preservative include thiazoline-based preservatives and benzisothiazole-based preservatives.

[0075] The aqueous dispersion composition of the present invention is obtained by emulsifying component (A) in the presence of component (B) (hereinafter also referred to as "emulsifier"). The emulsification method is not particularly limited, and known emulsification methods such as high-pressure emulsification and phase inversion emulsification can be used.

[0076] The high-pressure emulsification method involves premixing the emulsifier and water after molten component (A), performing microemulsification using a high-pressure emulsifier, and then removing the solvent as needed. The emulsified material can be molten by heating alone, dissolving it in a solvent and then heating it, or mixing it with a non-volatile substance such as a plasticizer and then heating it, but heating alone is preferred. Examples of solvents include organic solvents capable of dissolving the emulsified material, such as toluene, xylene, methylcyclohexane, and ethyl acetate.

[0077] The phase inversion emulsification method is a method in which component (A) is heated and melted, and then an emulsifier / water is added while stirring to first form a W / O emulsion, and then the phase is inverted to an O / W emulsion by adding water or changing the temperature.

[0078] The concentration of the resulting aqueous dispersion composition is not particularly limited; it is typically adjusted to a solids content of approximately 20% to 70% by mass. Furthermore, from the perspective of storage stability, the volume average particle size of the resulting aqueous dispersion composition is preferably less than approximately 0.7 μm. The resulting aqueous dispersion composition exhibits a white to milky white appearance and a viscosity of typically approximately 10 to 1,000 mPa·s (at 25°C and a concentration of 50% by mass).

[0079] The pH of the aqueous dispersion composition obtained above is generally about 2 to 10. Furthermore, the pH of the aqueous dispersion composition may be adjusted, as necessary, by adding an inorganic acid such as hydrochloric acid, sulfuric acid, or phosphoric acid; an alkanolamine such as monomethylamine, monoethanolamine, diethanolamine, or diisopropanolamine; an aliphatic amine such as ethylamine, n-butylamine, or triethylamine; an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide; or an alkaline earth metal hydroxide such as calcium hydroxide.

[0080] [Tackifying resin aqueous dispersion composition]

[0081] The aqueous tackifying resin dispersion of the present invention includes the aqueous dispersion of the present invention. The aqueous dispersion of the present invention can function as a tackifier by being used in a pressure-sensitive adhesive / adhesive (including the aqueous pressure-sensitive adhesive composition / aqueous adhesive composition described below).

[0082] [Water-based pressure-sensitive adhesive composition / water-based adhesive composition]

[0083] The aqueous pressure-sensitive adhesive composition / aqueous adhesive composition of the present invention comprises the aqueous dispersion composition of the present invention (or the tackifying resin aqueous dispersion composition of the present invention) and a base polymer. In addition, the aqueous pressure-sensitive adhesive composition / aqueous adhesive composition of the present invention can be used as an aqueous pressure-sensitive adhesive / aqueous adhesive. In addition, in this specification, "pressure-sensitive adhesive / adhesive" clearly refers to a substance containing either or both of a pressure-sensitive adhesive and an adhesive.

[0084] Above-mentioned base polymer for example enumerates acrylic polymer emulsion, rubber latex and synthetic resin emulsion etc.This base polymer can use 1 kind alone, also can use with 2 or more combination.In addition, as required, can also use pH adjusting agent such as crosslinking agent, defoamer, viscosity modifier, filler, antioxidant, water-proofing agent, film-making aid, preservative, ammoniacal liquor and sodium bicarbonate, leveling agent, peeling modifier, plasticizer, softener, colorant (pigment, dye etc.), surfactant, antistatic agent, anti-aging agent, ultraviolet absorber, light stabilizer etc.In addition, can further use known water-dispersed composition.For the concentration of these aqueous pressure-sensitive adhesive compositions / aqueous adhesive compositions, usually solid content is 40 mass %~70 mass %, is preferably 55 mass %~70 mass %.

[0085] As the acrylic polymer emulsion, those commonly used in various aqueous pressure-sensitive adhesive compositions / aqueous adhesive compositions can be used, for example, acrylic polymers containing a monomer component of an alkyl (meth)acrylate. The acrylic polymer emulsion can be produced using various known emulsion polymerization methods. For example, it can be easily produced by a known emulsion polymerization method such as a single charge polymerization method of the monomer component in the presence of a polymerization initiator, a stepwise monomer addition polymerization method, a stepwise emulsified monomer addition polymerization method, or a seed polymerization method. The acrylic polymer emulsion can be used alone or in combination of two or more.

[0086] Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate. These alkyl (meth)acrylates may be used alone or in combination of two or more.

[0087] The monomer components in the acrylic polymer emulsion may further contain other monomers copolymerizable with the alkyl (meth)acrylate. Examples of such monomers include carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, cyano group-containing monomers, ketone group-containing monomers, monomers having a nitrogen atom-containing ring, alkoxysilyl group-containing monomers, and polyfunctional monomers.

[0088] Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid (AA), methacrylic acid (MAA), and crotonic acid; and ethylenically unsaturated dicarboxylic acids such as maleic acid, itaconic acid, and citraconic acid, and their anhydrides (maleic anhydride, itaconic anhydride, etc.).

[0089] Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate; and unsaturated alcohols such as vinyl alcohol and allyl alcohol.

[0090] Examples of the amide group-containing monomer include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, and N-butoxymethyl(meth)acrylamide.

[0091] Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate.

[0092] Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, and allyl glycidyl ether. Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile. Examples of the ketone group-containing monomer include diacetone (meth)acrylamide, diacetone (meth)acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, and vinyl acetoacetate.

[0093] Examples of the above-mentioned monomers having a nitrogen atom-containing ring include N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, and N-(meth)acryloylmorpholine.

[0094] Examples of the alkoxysilyl group-containing monomer include 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, and 3-(meth)acryloyloxypropylmethyldiethoxysilane.

[0095] Examples of the polyfunctional monomer include 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, glycerol di(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinylbenzene, butyl di(meth)acrylate, and hexyl di(meth)acrylate.

[0096] The content of the other monomer copolymerizable with the alkyl (meth)acrylate in the monomer components is not particularly limited, but is preferably about 40% by mass or less relative to 100% by mass of the monomer components.

[0097] The above-mentioned monomer components may further contain vinyl ester monomers such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene, substituted styrenes (such as α-methylstyrene), and vinyltoluene; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, and isobornyl (meth)acrylate; aromatic ring-containing (meth)acrylates such as aryl (meth)acrylates (such as phenyl (meth)acrylate), aryloxyalkyl (meth)acrylates (such as phenoxyethyl (meth)acrylate), and arylalkyl (meth)acrylates (such as benzyl (meth)acrylate); olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; chlorine-containing monomers such as vinyl chloride and vinylidene chloride; isocyanate-containing monomers such as 2-(meth)acryloyloxyethyl isocyanate; alkoxy-containing monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; and vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether. The content of these monomers is not particularly limited, but is preferably about 10% by mass or less relative to 100% by mass of the above-mentioned monomer components.

[0098] The polymerization initiator is not particularly limited, and examples thereof include azo initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate, 2,2'-azobis(N,N'-dimethyleneisobutylamidine), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride; 1,1-bis(1,1-dihydrogen iodide) Peroxide initiators such as (tert-hexylperoxy)-3,3,5-trimethylcyclohexane, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, tert-hexylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyisobutyrate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxylaurate, benzoyl peroxide, tert-butyl hydroperoxide, and hydrogen peroxide; and persulfate initiators such as potassium persulfate and ammonium persulfate. Polymerization initiators may be used alone or in combination of two or more.

[0099] The weight-average molecular weight (Mw) of the acrylic polymer in the acrylic polymer emulsion is not particularly limited, but is generally in the range of approximately 100,000 to 5,000,000. From the perspective of improving adhesive properties, the weight-average molecular weight (Mw) of the acrylic polymer is preferably 1,500,000 or less, more preferably 1,000,000 or less. From the perspective of cohesiveness, etc., it is preferably 200,000 or more, more preferably 300,000 or more. In this specification, the weight-average molecular weight refers to the polystyrene-equivalent value as determined by gel permeation chromatography (GPC).

[0100] The content ratio of the acrylic polymer emulsion and the aqueous dispersion composition is not particularly limited. However, as an appropriate range for fully exhibiting the modifying effect of the aqueous dispersion composition and preventing a decrease in heat resistance retention, viscosity, etc. due to excessive use, the aqueous dispersion composition is generally preferably present in an amount of about 2 to 40 parts by mass per 100 parts by mass of the acrylic polymer emulsion, calculated as solid content.

[0101] As the rubber latex, various known materials used in water-based pressure-sensitive adhesive compositions / water-based adhesive compositions can be used. Examples of the rubber latex include natural rubber latex and synthetic rubber latex. Natural rubber latex may also be modified natural rubber obtained by grafting an alkyl (meth)acrylate onto natural rubber. These rubber latexes may be used alone or in combination of two or more.

[0102] The above-mentioned synthetic rubber latex is an aqueous dispersion of a synthetic polymer. Examples of the synthetic polymer include polyisoprene, styrene-butadiene rubber (SBR), styrene-isoprene (SI) rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, styrene-butadiene-styrene block copolymer (SBS) rubber, styrene-ethylene-butylene-styrene block copolymer (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-ethylene-propylene block copolymer (SEP) rubber, recycled rubber, butyl rubber, polyisobutylene, styrene-butadiene-vinylpyridine rubber, polybutadiene, methyl methacrylate-butadiene rubber, acrylonitrile-butadiene rubber (NBR), and polychloroprene (CR).

[0103] The content ratio of the rubber latex and the water-dispersible composition is not particularly limited. As an appropriate usage range that can fully demonstrate the modification effect of the water-dispersible composition and does not cause a decrease in adhesive strength, viscosity, etc. due to excessive use, it is generally preferably set to about 10 to 150 parts by mass of the water-dispersible composition per 100 parts by mass of the rubber latex, calculated as solid content.

[0104] As the synthetic resin emulsion, various known substances used in water-based pressure-sensitive adhesive compositions / water-based adhesive compositions can be used, for example, synthetic resin emulsions such as vinyl acetate emulsions, ethylene-vinyl acetate copolymer emulsions, and urethane emulsions. These synthetic resin emulsions may be used alone or in combination of two or more.

[0105] The content ratio of the above-mentioned synthetic resin emulsion and water-dispersible composition is not particularly limited. As an appropriate usage range that can fully demonstrate the modification effect brought about by the water-dispersible composition and does not cause a decrease in adhesive strength, viscosity, etc. due to excessive use, it is generally preferable to set the water-dispersible composition to about 2 to 40 parts by mass based on solid content per 100 parts by mass of the synthetic resin emulsion.

[0106] As long as the desired properties are not impaired, the aqueous pressure-sensitive adhesive composition / aqueous adhesive composition of the present invention may also contain various additives such as cross-linking agents, defoaming agents, viscosity modifiers, fillers, antioxidants, water resistance agents, film-forming aids, preservatives, pH adjusters such as ammonia water and sodium bicarbonate, leveling agents, release modifiers, plasticizers, softeners, colorants (pigments, dyes, etc.), surfactants, antistatic agents, anti-aging agents, ultraviolet absorbers, and light stabilizers.

[0107] Examples of the crosslinking agent include isocyanate crosslinking agents and epoxy crosslinking agents. The content of the crosslinking agent is not particularly limited, but is generally 20 parts by mass or less, preferably about 0.01 to 10 parts by mass, per 100 parts by mass of the base polymer.

[0108] Examples of the isocyanate crosslinking agent include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; alicyclic polyisocyanates such as cyclopentyl diisocyanate, cyclohexyl diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated xylene diisocyanate; aromatic polyisocyanates such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylene diisocyanate; and their biuret forms, isocyanurate forms, allophanate forms, and adduct forms, and complexes obtained by reacting two or more of the isocyanate forms, isocyanurate forms, allophanate forms, and adduct forms.

[0109] Examples of the epoxy crosslinking agent include bisphenol A epichlorohydrin-type epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diamine glycidyl amine, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N'-diaminoglycidylaminomethyl)cyclohexane, and other compounds having two or more epoxy groups in the molecule.

[0110] The aqueous pressure-sensitive adhesive composition of the present invention can be obtained by mixing the aqueous dispersion composition, the base polymer, and various additives as needed. The mixing method is not particularly limited, and various known methods can be used.

[0111] [Pressure-sensitive adhesive sheet / adhesive sheet]

[0112] The pressure-sensitive adhesive sheet of the present invention comprises a pressure-sensitive adhesive layer composed of the above-mentioned water-based pressure-sensitive adhesive composition and a substrate. The pressure-sensitive adhesive sheet of the present invention may be a substrate-attached pressure-sensitive adhesive sheet, in which the pressure-sensitive adhesive layer is provided on one or both sides of the substrate, or a substrate-free pressure-sensitive adhesive sheet, in which the pressure-sensitive adhesive layer is supported on a release liner (which can also be understood as a substrate having a release surface). The concept of the pressure-sensitive adhesive sheet includes pressure-sensitive adhesive tapes, pressure-sensitive adhesive labels, and pressure-sensitive adhesive films.

[0113] As the substrate, for example, 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, fluororesin films, other cellophane-based plastic films; Japanese paper, kraft paper, glassine paper, high-quality paper, synthetic paper, top-coated paper, etc. can be used. Woven and non-woven fabrics made from fibrous materials such as natural fibers, semi-synthetic fibers, or synthetic fibers, such as cotton, staple fibers, abaca, pulp, rayon, acetate, polyester, polyvinyl alcohol, polyamide, and polyolefin fibers, either alone or in blends; rubber sheets made from natural rubber, butyl rubber, and the like; foam sheets made from foams such as expanded polyurethane and expanded polychloroprene rubber; metal foils such as aluminum foil and copper foil; and composites thereof. The aforementioned films may be either non-stretched or stretched (uniaxially stretched or biaxially stretched). The substrate may be in a single-layer or laminated form.

[0114] Furthermore, various additives such as fillers (inorganic fillers, organic fillers, etc.), anti-aging agents, antioxidants, ultraviolet absorbers, lubricants, plasticizers, and colorants (pigments, dyes, etc.) may be blended into the base material as needed.

[0115] The surface of the substrate (particularly the surface on the polymer layer side) may be subjected to appropriate known or customary surface treatments such as physical treatments such as corona discharge treatment and plasma treatment, or chemical treatments such as primer treatment and back surface treatment.

[0116] The pressure-sensitive adhesive sheet / adhesive sheet of the present invention can be manufactured by a known method. First, the above-mentioned water-based pressure-sensitive adhesive composition / water-based adhesive composition is applied to one or both sides of a substrate to form a coating layer formed by the water-based pressure-sensitive adhesive composition / water-based adhesive composition. The coating method can use a known method, including a roll coater method, a comma coater method, a die coater method, a reverse coater method, a screen method, and a gravure coater method. Then, by heating or drying the coating layer, a pressure-sensitive adhesive layer / adhesive layer formed by the above-mentioned water-based pressure-sensitive adhesive composition / water-based adhesive composition is formed. The conditions during heating or drying can be appropriately set according to the thickness of the pressure-sensitive adhesive layer / adhesive layer, for example, the temperature is 10° C. to 120° C., and the time is, for example, 0.1 hour to 10 hours. The thickness of the pressure-sensitive adhesive layer / adhesive layer (thickness after drying) varies according to the application and is preferably 5 μm to 200 μm.

[0117] Example

[0118] The present invention is described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified, "parts" and "%" in the examples are by mass.

[0119] <Measurement of Weight Average Molecular Weight (Mw)>

[0120] The weight average molecular weight (Mw) of the rosin-based resins (A-1) to (A'-5) in Production Examples 2 to 10 was determined by gel permeation chromatography (GPC) using a standard polystyrene calibration curve and calculated as a polystyrene-equivalent value. GPC measurements were performed under the following conditions.

[0121] Analyzer: HLC-8320 (manufactured by Tosoh Corporation)

[0122] Column: TSKgelSuperHM-L×3 columns

[0123] Eluent: tetrahydrofuran

[0124] Injection sample concentration: 5 mg / mL

[0125] Flow rate: 0.6mL / min

[0126] Injection volume: 40 μL

[0127] Column temperature: 40°C

[0128] Detector: RI

[0129] <Content of Components Having a Weight Average Molecular Weight (Mw) of 6,000 or More>

[0130] The content (mass %) of the component having a weight average molecular weight (Mw) of 6,000 or greater in the rosin-based resins (A-1) to (A'-5) in Production Examples 2 to 10 was calculated using the following formula based on the GPC chart obtained by the above method.

[0131] Content (mass %) of components having a weight average molecular weight (Mw) of 6,000 or more = [peak area value (S2) of components having a weight average molecular weight of 6,000 or more / total peak area value (S1)] × 100

[0132] (Acid value and hydroxyl value)

[0133] The acid value (mgKOH / g) and the hydroxyl value (mgKOH / g) of the rosin-based resins (A-1) to (A'-5) in Production Examples 2 to 10 were measured in accordance with JIS K0070.

[0134] <Manufacturing of base polymers>

[0135] Production Example 1

[0136] An aqueous solution consisting of 43.4 parts of water and 0.92 parts of polyoxyethylene alkyl ether sulfate ammonium salt (anionic emulsifier: trade name "Hitenol LA-16," manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping funnel, and nitrogen inlet tube under a nitrogen stream, and the temperature was raised to 70°C. Next, a mixture consisting of 90 parts of butyl acrylate, 7 parts of 2-ethylhexyl acrylate, and 3 parts of acrylic acid, along with 1 / 10 of an aqueous initiator solution consisting of 0.24 parts of potassium persulfate (polymerization initiator), 0.11 parts of sodium bicarbonate (pH adjuster), and 8.83 parts of water, was added to the reaction vessel, and a preliminary polymerization reaction was carried out at 70°C under a nitrogen stream for 30 minutes. Subsequently, the above mixture and the remaining 9 / 10 of the aqueous initiator solution were added to the reaction vessel over 2 hours to carry out emulsion polymerization, and then the temperature was maintained at 70°C for 1 hour to complete the polymerization reaction. The acrylic polymer emulsion thus obtained was cooled to room temperature and then filtered using a 100-mesh metal mesh to obtain an acrylic polymer emulsion having a solid content concentration of 47.8%.

[0137] <Production of Rosin-Based Resin (A)>

[0138] Production Example 2

[0139] In a reaction vessel equipped with a stirrer, a condenser, a thermometer, and nitrogen / water vapor inlet tubes, 70 parts of polymerized rosin (acid value 145 mgKOH / g, softening point 140°C) and 30 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) were added and melted at 220°C. Subsequently, 12 parts of pentaerythritol were added, and the temperature was raised to 250°C and allowed to react at the same temperature for 2 hours. The temperature was then further raised to 280°C and allowed to react at the same temperature for 7 hours. Subsequently, the mixture was treated under reduced pressure for 5 hours to obtain a polymerized rosin ester (A-1) having a weight-average molecular weight (Mw) of 2,200 and containing 6% of components having a weight-average molecular weight (Mw) of 6,000 or greater (hereinafter referred to as component (A-1)). Component (A-1) had an acid value of 6 mgKOH / g and a hydroxyl value of 45 mgKOH / g.

[0140] Production Example 3

[0141] In the same reaction vessel as in Production Example 2, 45 parts of polymerized rosin (acid value 145 mgKOH / g, softening point 140°C) and 55 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) were added and melted at 220°C. Subsequently, 11 parts of pentaerythritol were added, and the temperature was raised to 250°C, where the mixture was reacted for 2 hours. The temperature was further raised to 280°C, where the mixture was reacted for 7 hours to complete esterification. Subsequently, the mixture was subjected to a 5-hour decompression treatment to obtain a polymerized rosin ester (A-2) having a weight-average molecular weight (Mw) of 2,000 and a content of 4% of components having a weight-average molecular weight (Mw) of 6,000 or greater (hereinafter referred to as component (A-2)). Component (A-2) had an acid value of 7 mgKOH / g and a hydroxyl value of 24 mgKOH / g.

[0142] Production Example 4

[0143] In the same reaction vessel as in Production Example 2, 20 parts of polymerized rosin (acid value 145 mgKOH / g, softening point 140°C) and 80 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) were added and melted at 220°C. Subsequently, 11 parts of pentaerythritol were added, and the temperature was raised to 250°C, where the mixture was reacted for 2 hours. The temperature was further raised to 280°C, where the mixture was reacted for 7 hours. Subsequently, the mixture was subjected to a reduced pressure treatment for 5 hours to obtain a polymerized rosin ester (A-3) having a weight-average molecular weight (Mw) of 1,600 and a content of 2% of components having a weight-average molecular weight (Mw) of 6,000 or greater (hereinafter referred to as component (A-3)). Component (A-3) had an acid value of 10 mgKOH / g and a hydroxyl value of 35 mgKOH / g.

[0144] Production Example 5

[0145] In the same reaction vessel as in Production Example 2, 85 parts of polymerized rosin (acid value 145 mgKOH / g, softening point 140°C) and 15 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) were added and melted at 220°C. Subsequently, 12 parts of pentaerythritol were added, and the temperature was raised to 250°C, where the mixture was reacted for 2 hours. The temperature was further raised to 280°C, where the mixture was reacted for 7 hours. Subsequently, the mixture was subjected to a 5-hour decompression treatment to obtain a polymerized rosin ester (A-4) having a weight-average molecular weight (Mw) of 2,500 and a content of components having a weight-average molecular weight (Mw) of 6,000 or greater (hereinafter referred to as component (A-4)). Component (A-4) had an acid value of 6 mgKOH / g and a hydroxyl value of 30 mgKOH / g.

[0146] Production Example 6

[0147] In the same reaction vessel as in Production Example 2, 100 parts of polymerized rosin (acid value 145 mgKOH / g, softening point 140°C) was added and melted at 220°C. Subsequently, 11 parts of pentaerythritol was added, the temperature was raised to 250°C, and the mixture was reacted at the same temperature for 2 hours. The temperature was further raised to 280°C, and the mixture was reacted at the same temperature for 9 hours to complete esterification. Subsequently, the mixture was subjected to a 2-hour decompression treatment to obtain a polymerized rosin ester (A'-1) having a weight-average molecular weight (Mw) of 2,600 and containing 10% of components having a weight-average molecular weight (Mw) of 6,000 or greater (hereinafter referred to as component (A'-1)). Component (A'-1) had an acid value of 12 mgKOH / g and a hydroxyl value of 40 mgKOH / g.

[0148] Production Example 7

[0149] In the same reaction vessel as in Production Example 2, 100 parts of polymerized rosin (acid value 145 mgKOH / g, softening point 140°C) was added and melted at 220°C. Subsequently, 12 parts of pentaerythritol was added, the temperature was raised to 250°C, and the mixture was reacted at the same temperature for 2 hours. The temperature was further raised to 280°C, and the mixture was reacted at the same temperature for 14 hours. Subsequently, the mixture was subjected to a 3-hour decompression treatment to obtain a polymerized rosin ester (A'-2) having a weight-average molecular weight (Mw) of 3,200 and containing 15% of components having a weight-average molecular weight (Mw) of 6,000 or more (hereinafter referred to as component (A'-2)). Component (A'-2) had an acid value of 7 mgKOH / g and a hydroxyl value of 40 mgKOH / g.

[0150] Production Example 8

[0151] In the same reaction vessel as in Production Example 2, 100 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) was added and melted at 130°C. Subsequently, 22 parts of maleic anhydride was added, the temperature was raised to 170°C, and 25 parts of pentaerythritol was added. The temperature was then raised to 220°C and reacted at the same temperature for 7 hours to obtain a maleated rosin ester (A'-3) having a weight-average molecular weight (Mw) of 1,500 and a content of 6% of components having a weight-average molecular weight (Mw) of 6,000 or greater (hereinafter referred to as component (A'-3)). The acid value of component (A'-3) was 130 mgKOH / g.

[0152] Production Example 9

[0153] In the same reaction vessel as in Production Example 2, 100 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) was added and melted at 170°C. Subsequently, 20 parts of fumaric acid was added, the temperature was raised to 220°C, and the mixture was reacted at the same temperature for 2 hours. Subsequently, 7 parts of glycerin was added, the temperature was raised to 210°C, and the mixture was reacted at the same temperature for 3 hours. This yielded a fumarated rosin ester (A'-4) having a weight-average molecular weight (Mw) of 1,100 and containing 3% of components having a weight-average molecular weight (Mw) of 6,000 or greater (hereinafter referred to as component (A'-4)). The acid value of component (A'-4) was 190 mgKOH / g.

[0154] Production Example 10

[0155] In the same reaction vessel as in Production Example 2, 100 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) was added and melted at 170°C. Subsequently, 10 parts of maleic anhydride and 18 parts of glycerin were added, the temperature was raised to 270°C, and the mixture was reacted at the same temperature for 1 hour. Subsequently, the mixture was subjected to a reduced pressure treatment for 1 hour to obtain a maleated rosin ester (A'-5) having a weight-average molecular weight (Mw) of 3,200 and containing 17% of components having a weight-average molecular weight (Mw) of 6,000 or greater (hereinafter referred to as component (A'-5)). The acid value of component (A'-5) was 23 mgKOH / g.

[0156] <Production of Emulsifier (B)>

[0157] Production Example 11

[0158] In a four-necked flask equipped with a nitrogen inlet, thermometer, reflux condenser, and stirring device, 30 parts of methyl acrylate, 12 parts of methyl methacrylate, 30 parts (solids basis) of a polyoxyethylene phenyl ether reactive emulsifier (trade name "Aqualon RN-20," manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 15 parts of sodium styrene sulfonate, and 13 parts of styrene were added. Furthermore, 10 parts of ion-exchanged water was added to prepare an aqueous monomer solution. Next, 5 parts of 2,4-diphenyl-4-methyl-1-pentene, 2.4 parts of ammonium persulfate, and 72 parts of ion-exchanged water were added to this aqueous monomer solution. The reaction system was heated to 85°C and held for 2 hours to allow free radical polymerization to proceed. Next, 1 part of ammonium persulfate was added to the reaction system, and the temperature was maintained for another hour. Finally, 14 parts of a 48% aqueous sodium hydroxide solution was added to the reaction system, stirred thoroughly, and cooled to room temperature. In this manner, an aqueous solution of a high molecular weight emulsifier (B-1) (hereinafter referred to as component (B-1)) having a solid content of 21.0% was obtained.

[0159] Production Example 12

[0160] In the same reaction vessel as in Production Example 11, 12.8 parts of methyl methacrylate, 26.6 parts of styrene, 26.6 parts of α-methylstyrene, 34 parts of methacrylic acid, 333 parts of ion-exchanged water, and 1.7 parts of n-dodecylmercaptan as a chain transfer agent were added. The mixture was heated to 80°C while stirring under nitrogen bubbling. 5 parts of ammonium persulfate (APS) was added as a polymerization initiator, and the temperature was raised to 90°C and maintained for 120 minutes. Then, 17.7 parts of a 48% aqueous sodium hydroxide solution and a prescribed amount of ion-exchanged water were added to the reaction system, followed by thorough stirring and cooling to room temperature. This yielded an aqueous solution of a high molecular weight emulsifier (B-2) (hereinafter referred to as component (B-2)) with a solids content of 23.0%.

[0161] [Production of Water-Dispersible Composition]

[0162] Example 1

[0163] 100 parts of the component (A-1) of Production Example 2 was dissolved in 80 parts of methylcyclohexane at 80°C for 3 hours, and then 3 parts of the component (B-1) (based on solid content) and 140 parts of water were added and stirred for 1 hour. Subsequently, high-pressure emulsification was performed at a pressure of 30 MPa using a high-pressure emulsifier (manufactured by Manton Gaulin Co., Ltd.) to obtain an emulsion. Subsequently, the mixture was heated at 70°C and 2.93×10 -2 Under the conditions of 100 MPa, vacuum distillation was performed for 6 hours to obtain an aqueous dispersion composition with a solid content concentration of 50%.

[0164] Example 2 to Example 4

[0165] A water-dispersed composition having a solid content concentration of 50% was obtained in the same manner as in Example 1 except that the component (A-1) was changed to the components (A-2) to (A-4).

[0166] Example 5

[0167] A water-dispersed composition having a solid content concentration of 50% was obtained in the same manner as in Example 1 except that the component (B-1) was changed to the component (B-2).

[0168] Example 6

[0169] A water-dispersible composition with a solid content concentration of 50% was obtained in the same manner as in Example 1, except that the component (B-1) in Example 1 was changed to 3 parts (in terms of solid content) of disodium polyoxyethylene alkyl (C 12-14) sulfosuccinate (hereinafter referred to as component (B-3)).

[0170] Comparative Examples 1 to 5

[0171] A water-dispersed composition having a solid content concentration of 50% was obtained in the same manner as in Example 1 except that the component (A-1) was changed to the components (A'-1) to (A'-5).

[0172] (Evaluation of emulsification properties)

[0173] The volume average particle size of the aqueous dispersion compositions of each Example and Comparative Example was measured using a laser diffraction particle size analyzer (manufactured by Shimadzu Corporation, trade name "SALD-7500nano") under the conditions of a refractive index of 1.70-0.20i and an absorbance of 0.06. The resulting volume average particle size was evaluated according to the following criteria. The results are shown in Table 1. The smaller the volume average particle size, the better the emulsification and storage stability of the aqueous dispersion composition.

[0174] ○: Volume average particle size less than 0.5 μm

[0175] △: Volume average particle size 0.5 μm or more and less than 0.7 μm

[0176] ×: Volume average particle size 0.7 μm or more

[0177] Furthermore, the aqueous dispersion compositions of each Example and Comparative Example were filtered through a 150-mesh wire mesh, and the resulting residue was weighed relative to the weight percentage of the rosin-based resin (A). The weight percentage of this residue was evaluated according to the following criteria. The results are shown in Table 1. The lower the weight percentage of the residue, the more the formation of aggregates in the aqueous dispersion composition is suppressed, and the better the emulsification properties.

[0178] ○: less than 0.1% by weight

[0179] Δ: 0.1 wt% or more and less than 0.5 wt%

[0180] ×: 0.5 wt% or more

[0181] [Manufacturing of Water-Based Pressure-Sensitive Adhesive Composition / Water-Based Adhesive Composition]

[0182] 90 parts (solids content conversion) of the acrylic polymer emulsion synthesized in Preparation Example 1 and 10 parts (solids content conversion) of the aqueous dispersion composition of Example 1 were mixed to obtain a water-based pressure-sensitive adhesive composition / water-based adhesive composition. Water-based pressure-sensitive adhesive compositions / water-based adhesive compositions were similarly prepared for each of the aqueous dispersion compositions of Examples 2 to 6 and Comparative Examples 1 to 5.

[0183] [Preparation of sample tape]

[0184] The water-based pressure-sensitive adhesive composition / water-based adhesive composition was applied to a polyester film (trade name "S-100", manufactured by Mitsubishi Chemical Co., Ltd., thickness: 38 μm) using a dice-type applicator (manufactured by Taiyu Kizai Co., Ltd.) in a thickness of about 50 μm, and then dried in a circulating air dryer at 105°C for 5 minutes to prepare a sample tape.

[0185] (Evaluation of constant load peeling)

[0186] The sample tape was cut into a width of 25 mm and laminated to the adherend (polyethylene sheet (PE)) by reciprocating a 2 kg roller twice. The tape was then left to stand for 1 day. A load of 200 g was then applied to the end of the tape, and the tape was fixed so as to be peeled at 90°. The peel distance (mm) was measured every hour at 23°C. The peel distance was evaluated according to the following criteria. The results are shown in Table 1. The shorter the peel distance, the better the bonding strength of the aqueous pressure-sensitive adhesive composition / aqueous adhesive composition.

[0187] ◎: Peeling distance per hour is less than 20mm

[0188] ○: Peeling distance per hour is 20 mm or more and less than 30 mm

[0189] △: Peeling distance per hour is 30 mm or more and less than 50 mm

[0190] ×: Peeling distance per hour is 50 mm or more

[0191] [Table 1]

[0192]

[0193] The annotations in Table 1 are as follows.

[0194] ※Value of the content (mass %) of the component having a weight average molecular weight of 6,000 or more in the component (A).

Claims

1. A water-dispersible composition comprising a rosin-based resin (A) having a weight-average molecular weight of 2,000 to 3,000 and an emulsifier (B), wherein the content of components having a weight-average molecular weight of 6,000 or greater in the rosin-based resin (A) is less than 10% by mass; and the acid value of the rosin-based resin (A) is 5 mgKOH / g to 9 mgKOH / g.

2. The aqueous dispersion composition according to claim 1, wherein Component (A) is a rosin ester.

3. A tackifying resin aqueous dispersion composition comprising the aqueous dispersion composition according to claim 1 or 2.

4. A water-based pressure-sensitive adhesive composition or a water-based adhesive composition comprising the water-dispersible composition according to claim 1 or 2 and a base polymer.

5. The aqueous pressure-sensitive adhesive composition / aqueous adhesive composition according to claim 4, wherein: The base polymer is an acrylic polymer emulsion.

6. A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer comprising the aqueous pressure-sensitive adhesive composition according to claim 4 or 5, and a substrate.

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