Water-dispersed composition, water-dispersed tackifier resin composition, water-based pressure-sensitive adhesive composition, and pressure-sensitive adhesive sheet

Abstract

To provide a new water dispersion composition that has excellent emulsifiability and contains a rosin-based resin.SOLUTION: A water dispersion composition contains a rosin-based resin (A) with a weight average molecular weight of 1,600-3,000 and an emulsifier (B). In the rosin-based resin (A), the content of a component with a weight average molecular weight of 6,000 or more is less than 10 mass%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a water-dispersed composition, a water-dispersed tackifier resin composition, a water-based pressure-sensitive adhesive composition, and a pressure-sensitive adhesive sheet. [Background technology]

[0002] Rosin resins are widely used in various fields, such as tackifiers for adhesives and tackifiers for hot melts 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 have traditionally been generally dissolved in organic solvents, but in recent years, in consideration of the environment, safety and hygiene, resource conservation, and the like, aqueous dispersion compositions in which the resins are dispersed or emulsified in water are becoming mainstream.

[0003] As water-dispersed compositions of rosin-based resins, those emulsified in the presence of various anionic emulsifiers or nonionic emulsifiers have been proposed (see Patent Documents 1 and 2). However, some of the conventional water-dispersed compositions generate a large amount of aggregates, and the emulsifiability of the compositions is still insufficient. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-106259 A [Patent Document 2] Japanese Patent Application Publication No. 11-61087 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a water-dispersed composition containing a novel rosin-based resin, which has excellent emulsification properties. [Means for solving the problem]

[0006] As a result of extensive investigations, the present inventors have found that the above-mentioned problems can be solved by an aqueous dispersion composition containing a specific rosin-based resin. That is, the present invention relates to the following aqueous dispersion composition, aqueous dispersion composition of a tackifier resin, aqueous pressure-sensitive adhesive composition, and pressure-sensitive adhesive sheet.

[0007] 1. A composition comprising a rosin-based resin (A) having a weight average molecular weight of 1,600 to 3,000 and an emulsifier (B), A water-dispersed composition, 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 mass%.

[0008] 2. The water-dispersed composition according to item 1, wherein the component (A) is a rosin ester.

[0009] 3. A tackifier resin aqueous dispersion composition comprising the aqueous dispersion composition according to item 1 or 2.

[0010] 4. An aqueous pressure-sensitive adhesive composition comprising the aqueous dispersion composition according to item 1 or 2 above and a base polymer.

[0011] 5. The aqueous pressure-sensitive adhesive composition according to item 4, wherein the base polymer is an acrylic polymer emulsion.

[0012] 6. A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer made of the aqueous pressure-sensitive adhesive composition according to item 4 or 5 above, and a substrate. Effect of the Invention

[0013] The aqueous dispersion composition of the present invention is suppressed from generating aggregates, has a small particle size, and has excellent emulsification properties. In addition, the aqueous dispersion composition of the present invention can impart excellent adhesive strength to an aqueous pressure-sensitive adhesive composition containing the aqueous dispersion composition. Furthermore, the aqueous dispersion composition of the present invention is also excellent in storage stability. BEST MODE FOR CARRYING OUT THEINVENTION

[0014] [Water dispersion composition] The water-dispersed composition of the present invention contains a rosin-based resin (A) (hereinafter referred to as component (A)) having a weight-average molecular weight of 1,600 to 3,000 and a content of components having a weight-average molecular weight of 6,000 or more of less than 10 mass %, and an emulsifier (B) (hereinafter referred to as component (B)).

[0015] <Rosin-based resin (A)> The component (A) is not particularly limited, and various known rosin-based resins can be used, so long as it has a weight-average molecular weight of 1,600 to 3,000 and contains less than 10% by mass of components with a weight-average molecular weight of 6,000 or more. The component (A) may be used alone or in combination of two or more.

[0016] When the weight average molecular weight of the (A) component is 1,600 or more, the emulsification property is excellent in a water-dispersed composition, and the adhesive strength is excellent in a water-based pressure-sensitive adhesive composition containing the same. When the weight average molecular weight of the (A) component is 3,000 or less, the emulsification property is excellent in a water-dispersed composition. From the viewpoint of excellent adhesive strength and emulsification strength, the weight average molecular weight of the (A) component is preferably about 1,800 to 2,500. In this specification, the weight average molecular weight is a polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method.

[0017] When the content of the component having a weight average molecular weight of 6,000 or more is less than 10% by mass, the component (A) has excellent emulsifiability in an aqueous dispersion composition, and has excellent adhesive strength in an aqueous pressure-sensitive adhesive composition containing the component. In terms of excellent adhesive strength and emulsifiability, the component (A) preferably has a smaller content of the component having a weight average molecular weight of 6,000 or more, preferably about 0 to 8% by mass. In this specification, the content (mass%) of the component having a weight average molecular weight of 6,000 or more in the component (A) is calculated from the ratio ((S2) / (S1)) of the total peak area value (S2) of the components having a weight average molecular weight of 6,000 or more to the total peak area value (S1) of the component (A) measured by gel permeation chromatography (GPC).

[0018] Examples of component (A) include natural rosins (gum rosin, tall oil rosin, wood rosin) derived from massoniana (Pinus massoniana), slash pine (Pinus elliottii), Merkusii (Pinus merkusii), Caribbean pine (Pinus caribaea), Sibo pine (Pinus kesiya), Loblolly pine (Pinus taeda), and Pinus palustris, refined rosins (hereinafter, natural rosins and refined rosins are collectively referred to as unmodified rosins), 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 resins.

[0019] The purified rosin can be obtained by using various known means. Specifically, the purified rosin can be obtained by using various known purification means such as distillation, extraction, recrystallization, and adsorption. The distillation method includes, for example, a method of distilling the natural rosin at a temperature of about 200 to 300° C. under a reduced pressure of about 0.01 to 3 kPa. The extraction method includes, for example, a method of making the natural rosin into an alkaline aqueous solution, extracting insoluble unsaponifiable matter with various organic solvents, and then neutralizing the aqueous layer. The recrystallization method includes, for example, a method of dissolving the natural rosin in an organic solvent as a good solvent, distilling off the solvent to obtain a concentrated solution, and further adding an organic solvent 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. The adsorption method may, for example, be a method in which unmodified rosin in a molten state or unmodified rosin in a solution state dissolved in an organic solvent is contacted with a porous adsorbent, for example, activated carbon, metal oxides such as alumina, zirconia, silica, molecular sieves, zeolite, and porous clay having fine holes.

[0020] The disproportionated rosin can be obtained by using various known means. Specifically, for example, the unmodified rosin can be obtained by a method (disproportionation) of heating the unmodified rosin in the presence of a disproportionation catalyst. As the disproportionation catalyst, various known catalysts such as supported catalysts on palladium-carbon, rhodium-carbon, platinum-carbon, etc.; metal powders such as nickel and platinum; and iodides such as iodine and iron iodide can be used. The amount of the catalyst used is usually about 0.01 to 5 parts by mass, preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the unmodified rosin. The reaction temperature is about 100 to 300°C, preferably about 150 to 290°C.

[0021] Furthermore, the disproportionated rosin used may be one obtained by subjecting a disproportionated rosin to the above-mentioned purification.

[0022] The hydrogenated rosin can be obtained by using various known means. Specifically, for example, the hydrogenated rosin can be obtained by hydrogenating the unmodified rosin under known hydrogenation conditions. For example, the hydrogenation conditions include a method of heating the unmodified rosin to about 100 to 300° C. under a hydrogen pressure of about 2 to 20 MPa in the presence of a hydrogenation catalyst. In addition, the hydrogen pressure is preferably about 5 to 20 MPa, and the reaction temperature is preferably about 150 to 300° C. As the hydrogenation catalyst, various known catalysts such as supported catalysts and metal powders can be used. As the supported catalysts, palladium-carbon, rhodium-carbon, ruthenium-carbon, platinum-carbon, and the like can be used. As the metal powder, nickel, platinum, and the like can be used. Among these, palladium, rhodium, ruthenium, and platinum-based catalysts are preferred because they increase the hydrogenation rate of the unmodified rosin and shorten the hydrogenation time. The amount of the hydrogenation catalyst used is usually about 0.01 to 5 parts by mass, and preferably about 0.01 to 2 parts by mass, based on 100 parts by mass of the unmodified rosin.

[0023] The hydrogenation may be carried out, if necessary, in a state where the unmodified rosin is dissolved in a solvent. The solvent to be used is not particularly limited, but may be any solvent that is inert to the reaction and easily dissolves the raw materials and products. Specifically, for example, cyclohexane, n-hexane, n-heptane, decalin, tetrahydrofuran, dioxane, etc. may be used alone or in combination of two or more. The amount of the solvent used is not particularly limited, but it is usually sufficient to use the solvent so that the solid content is 10% by mass or more, preferably about 10 to 70% by mass, relative to the unmodified rosin.

[0024] The hydrogenated rosin may be one obtained by subjecting hydrogenated rosin to the above-mentioned purification.

[0025] The polymerized rosin can be obtained by various known means, for example, by reacting the unmodified rosin as a raw material 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 about 40 to 160° C. for about 1 to 5 hours.

[0026] Specific examples of polymerized rosins include gum-based polymerized rosin using gum rosin as a raw material (e.g., trade name "Polymerized Rosin B-140" manufactured by Shinzhou (Wuping) Hayashi Chemical Co., Ltd.), tall oil-based polymerized rosin using tall oil rosin (e.g., trade name "Silvatac 140" manufactured by Arizona Chemical Company), and wood-based polymerized rosin using wood rosin (e.g., trade name "Dimalex" manufactured by Eastman Chemical Company).

[0027] The polymerized rosin may be one that has been subjected to various treatments, such as the above-mentioned purification, hydrogenation, disproportionation, and α,β-unsaturated carboxylic acid modification such as acrylation, maleinization, and fumaration, which will be described later. The various treatments may be used alone or in combination of two or more.

[0028] The α,β-unsaturated carboxylic acid modified rosin is obtained by subjecting the unmodified rosin to an addition reaction with an α,β-unsaturated carboxylic acid.

[0029] The α,β-unsaturated carboxylic acid is not particularly limited, and various known carboxylic acids 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 ester, fumaric acid half ester, itaconic acid half ester, etc. Among these, maleic acid, maleic anhydride, and fumaric acid are preferred.The amount of the α,β-unsaturated carboxylic acid used is usually about 1 to 20 parts by mass, preferably about 1 to 3 parts by mass, based on 100 parts by mass of the unmodified rosin from the viewpoint of emulsification.

[0030] The α,β-unsaturated carboxylic acid modified rosin can be obtained by using various known means. Specifically, for example, the α,β-unsaturated carboxylic acid is added to the unmodified rosin melted under heating, and the reaction is carried out at a temperature of about 180 to 240° C. for about 1 to 9 hours. The reaction may be carried out while blowing an inert gas such as nitrogen into a sealed reaction system. Furthermore, in the reaction, a known catalyst such as a Lewis acid such as zinc chloride, iron chloride, or tin chloride, or a Bronsted acid such as paratoluenesulfonic acid or methanesulfonic acid may be used. The amount of these catalysts used is usually about 0.01 to 10 mass% relative to the unmodified rosin.

[0031] The obtained α,β-unsaturated carboxylic acid modified rosin may contain the resin acid derived from the unmodified rosin, and the content thereof is less than 10% by mass.

[0032] (rosin esters) Examples of the rosin esters include reaction products of the unmodified rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, and α,β-unsaturated carboxylic acid-modified rosin (hereinafter, these are also collectively referred to as rosins) with alcohol. In this specification, the esterification products of unmodified rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, and α,β-unsaturated carboxylic acid-modified rosin are referred to as unmodified rosin ester, hydrogenated rosin ester, disproportionated rosin ester, polymerized rosin ester, and α,β-unsaturated carboxylic acid-modified rosin ester, respectively.

[0033] The alcohol is not particularly limited, and various known alcohols can be used. Examples of the alcohol include monohydric alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butyl alcohol, n-octyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, lauryl alcohol, cyclohexanol, benzyl alcohol, and borneol; 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'-isopropylidenedicyclohexanol, 4,8-bis(hydroxymethyl)tricyclo[5.2.1.0 2,6 ]Dihydric alcohols such as decane; trihydric alcohols such as glycerin, trimethylolethane, trimethylolpropane; tetrahydric alcohols such as pentaerythritol, diglycerin, di(trimethylolpropane); pentahydric alcohols such as triglycerin; hexahydric alcohols such as dipentaerythritol. The alcohol may be a glycidyl ether or glycidol that reacts with a carboxylic acid to form an ester. The above alcohols may be used alone or in combination of two or more.

[0034] The alcohol is preferably a trihydric to hexahydric alcohol, and more preferably glycerin, pentaerythritol, diglycerin, or dipentaerythritol, because these have excellent adhesive strength.

[0035] The rosin esters can be obtained by using various known means. Specifically, for example, the rosins and the alcohols are reacted at a temperature of about 150 to 300° C. for about 1 to 24 hours. The amounts of the rosins and the alcohols charged are not particularly limited, but are usually determined so that the OH group of the alcohol / COOH group of the rosins (equivalent ratio) is in the range of about 0.8 to 8, preferably about 1.1 to 1.3.

[0036] In the above-mentioned method for producing rosin esters, the esterification reaction can be carried out in the presence of a catalyst in order to shorten the reaction time. Examples of the catalyst include acid catalysts such as paratoluenesulfonic 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 iron chloride and calcium formate. The catalyst can be used alone or in combination of two or more. In addition, since water is generated as a result of the esterification reaction, the reaction can be carried out while removing the generated water from the system. Considering the color tone of the obtained rosin ester, it is desirable to carry out the reaction under an inert gas flow. In addition, the reaction can be carried out under pressure if necessary.

[0037] In the method for producing the rosin esters, the reaction may be carried out in an organic solvent that is non-reactive with the rosins and alcohol. Examples of the organic solvent include hexane, cyclohexane, toluene, and xylene. When an organic solvent is used, the organic solvent or unreacted raw materials can be distilled off under reduced pressure, if necessary.

[0038] In the above-mentioned method for producing rosin esters, the rosin esters obtained may be further subjected to various treatments such as the above-mentioned purification, hydrogenation, disproportionation, and α,β-unsaturated carboxylic acid modification. Moreover, the various treatments may be performed alone or in combination of two or more kinds.

[0039] In the method for producing the polymerized rosin ester or the α,β-unsaturated carboxylic acid-modified rosin ester, it is preferable to further react the polymerized rosin or the α,β-unsaturated carboxylic acid-modified rosin and the alcohol with unmodified rosin, since this reduces the content of components having a weight-average molecular weight of 6,000 or more.

[0040] The hydrogenated rosin ester, disproportionated rosin ester, polymerized rosin ester and α,β-unsaturated carboxylic acid-modified rosin ester may be produced by subjecting a reaction product of the unmodified rosin with the alcohol to hydrogenation, disproportionation, polymerization and modification with an α,β-unsaturated carboxylic acid, respectively.

[0041] (rosin phenolic resin) The rosin phenol resin is obtained by reacting the unmodified rosin with a phenol.

[0042] The phenols are not particularly limited, and various known phenols can be used. Specific examples include alkylphenols such as cresol, butylphenol, octylphenol, and nonylphenol, phenol, bisphenols, and naphthols. These may be used alone or in combination of two or more. In terms of emulsifiability, the amount of phenols used is usually about 0.8 to 1.5 moles per mole of the raw rosin.

[0043] The method for producing the rosin phenolic resin is not particularly limited, but may be, for example, a method in which the unmodified rosin and phenols are heated and reacted in the presence of an acid catalyst as necessary. The reaction temperature is usually 180 to 350°C, and the reaction is carried out for about 6 to 18 hours. The acid catalyst that can be used in the reaction is not particularly limited, but may be, for example, an inorganic acid catalyst such as sulfuric acid, hydrogen chloride, or boron trifluoride, or an organic acid catalyst such as paratoluenesulfonic acid or methanesulfonic acid. When an acid catalyst is used, it may be used in an amount of about 0.01 to 1.0 part by mass per 100 parts by mass of the unmodified rosin. The rosin phenolic resin may be an ester obtained by further reacting the resin obtained by the reaction with an alcohol. The alcohol used in this case is the same as above.

[0044] From the viewpoint of excellent emulsifiability and adhesive strength, component (A) is preferably a rosin ester, and from the same viewpoint, at least one selected from the group consisting of polymerized rosin ester and α,β-unsaturated carboxylic acid-modified rosin ester is more preferable, and from the same viewpoint, polymerized rosin ester is particularly preferable.

[0045] The component (A) may contain various additives as long as they do not impair the effects of the present invention. Examples of the additives include dehydrating agents, crystal nucleating agents, plasticizers, flow improvers, weather resistance agents, antioxidants, UV absorbers, heat stabilizers, light stabilizers, etc. The additives may be used alone or in combination of two or more.

[0046] Examples of the antioxidant include sulfur-based antioxidants, thiophosphite-based antioxidants, phosphorus-based antioxidants, and hindered phenol-based antioxidants.

[0047] The antioxidant includes, for example, Irganox (registered trademark) 565.

[0048] (Physical properties of rosin-based resin (A)) The physical properties of the (A) component are not particularly limited except for the weight average molecular weight. The hydroxyl value of the (A) component is preferably about 20 to 50 mgKOH / g from the viewpoint of excellent emulsifiability and adhesive strength. The acid value of the (A) component is preferably about 1 to 20 mgKOH / g from the viewpoint of excellent emulsifiability and adhesive strength, and more preferably about 5 to 9 mgKOH / g from the same viewpoint. In the present invention, the hydroxyl value and acid value are values ​​measured according to JIS K0070.

[0049] <Emulsifier (B)> The (B) component is not particularly limited, and various known emulsifiers can be used. Specific examples include high molecular weight emulsifiers obtained by polymerizing monomers, low molecular weight anionic emulsifiers, low molecular weight nonionic emulsifiers, etc. The (B) component may be used alone or in combination of two or more.

[0050] Examples of monomers used in the production of the high molecular weight emulsifier include (meth)acrylic acid ester 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, stearyl (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, styrene sulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid; and 2-(meth)acryloyloxyethyl a Examples of suitable monomers include phosphate vinyl monomers such as phosphate ester vinyl monomers such as acryloyl phosphate and diphenyl-2(meth)acryloyloxyphosphate; and alkali metal salts, alkaline earth metal salts, ammonium salts, and salts of organic bases of these 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)acrylic acid ester monomers such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; styrenes such as styrene, α-methylstyrene, and vinyl toluene; other monomers such as methyl vinyl ether, glycidyl (meth)acrylate, urethane acrylate, α-olefins having 6 to 22 carbon atoms, and vinyl pyrrolidone. These may be used alone or in combination of two or more.

[0051] The monomers used in the production of the above-mentioned high molecular weight emulsifier are preferably methyl (meth)acrylate, alkali metal salts of sulfonic acid vinyl monomers, and styrenes, from the viewpoints of polymerizability and emulsifying properties of the resulting high molecular weight emulsifier.

[0052] The polymerization method of the high molecular weight emulsifier can be solution polymerization, suspension polymerization, emulsion polymerization using a reactive emulsifier other than the high molecular weight emulsifier described below, a non-reactive emulsifier other than the high molecular weight emulsifier, etc. Examples of the non-reactive emulsifier include a low molecular weight anionic emulsifier and a low molecular weight nonionic emulsifier described below.

[0053] The weight-average molecular weight of the high molecular weight emulsifier is not particularly limited, but is usually preferably about 1,000 to 500,000 in terms of the adhesive properties of the resulting aqueous dispersion composition. In this specification, the weight-average molecular weight refers to a polyethylene oxide equivalent value measured by gel permeation chromatography (GPC).

[0054] Examples of reactive emulsifiers other than the high molecular weight emulsifiers include those having hydrophilic groups such as sulfonic acid groups and carboxyl groups, and hydrophobic groups such as alkyl groups and phenyl groups, and having a carbon-carbon double bond in the molecule. Examples of the carbon-carbon double bond include functional groups such as (meth)allyl groups, 1-propenyl groups, 2-methyl-1-propenyl groups, vinyl groups, isopropenyl groups, and (meth)acryloyl groups.

[0055] Examples of the reactive emulsifier include polyoxyethylene alkyl ethers having at least one of the functional groups in the molecule, polyoxyethylene phenyl ethers having at least one of the functional groups in the molecule, and their sulfosuccinates and sulfates, and further include polyoxyethylene alkyl phenyl ethers having at least one of the functional groups in the molecule, and their sulfosuccinates, sulfates, phosphates, and aliphatic or aromatic carboxylates. Other examples include acidic phosphoric acid (meth)acrylic acid ester emulsifiers, acid anhydride modified products of rosin glycidyl ester acrylate (see JP-A-4-256429), and emulsifiers described in JP-A-63-23725, JP-A-63-240931, and JP-A-62-104802. Further, the polyoxyethylene in the reactive emulsifier may be replaced with polyoxypropylene or a block copolymer or random copolymer of polyoxyethylene and polyoxypropylene.

[0056] Representative examples of commercially available reactive emulsifiers include "KAYAMER PM-1", "KAYAMER PM-2", "KAYAMER PM-21" (all manufactured by Nippon Kayaku Co., Ltd.), "SE-10N", "NE-10", "NE-20", "NE-30", "ADEKA REASOAP SR-10", "ADEKA REASOAP SR-20", "ADEKA REASOAP ER-20" (all manufactured by ADEKA Corporation), "New Frontier A229E", "New Frontier N117E", "New Frontier N250Z", "Aqualon RN-10", "Aqualon RN-20", "Aqualon RN-50", "Aqualon HS-10", "Aqualon KH-05", "Aqualon KH-10" (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), "Eminol JS-2" (manufactured by Sanyo Chemical Industries, Ltd.), and "Latherm K-180" (manufactured by Kao Corporation).

[0057] The reactive emulsifier is preferably a polyoxyethylene alkyl ether or polyoxyethylene phenyl ether from the viewpoints of polymerizability and the emulsifying properties of the resulting high molecular weight emulsifier.

[0058] Examples of the low molecular weight anionic emulsifier include dialkyl sulfosuccinate salts, alkanesulfonates, α-olefinsulfonates, polyoxyethylene alkyl sulfosuccinate salts, polyoxyethylene alkyl ether sulfosuccinate salts, polyoxyethylene styryl phenyl ether sulfosuccinate salts, naphthalenesulfonic acid formalin condensates, polyoxyethylene alkyl ether sulfate salts, polyoxyethylene dialkyl ether sulfate salts, polyoxyethylene trialkyl ether sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, etc. These may be used alone or in combination of two or more.

[0059] Examples of the low molecular weight nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene sorbitan fatty acid ester, etc. These may be used alone or in combination of two or more kinds.

[0060] The amount of the (B) component used is not particularly limited, but from the viewpoint of excellent emulsifiability, it is preferably about 1 to 20 parts by mass, and more preferably about 2 to 10 parts by mass, per 100 parts by mass of the (A) component, calculated as solid content.

[0061] The aqueous dispersion composition of the present invention may contain, as necessary, a crosslinking agent, an antifoaming agent, a thickener, a filler, an ultraviolet absorber, a light stabilizer, an antioxidant, a water-resistant agent, a film-forming assistant, a preservative, a pH adjuster such as aqueous ammonia or sodium bicarbonate, and the like, as long as the desired properties are not impaired.

[0062] Examples of the preservative include thiazoline-based preservatives and benzoisothiazole-based preservatives.

[0063] The water 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.

[0064] The high-pressure emulsification method is a method in which the (A) component is melted, an emulsifier and water are premixed, finely emulsified using a high-pressure emulsifier, and then the solvent is removed as necessary. The material to be emulsified may be melted by heating alone, by dissolving it in a solvent and then heating, or by mixing it with a non-volatile substance such as a plasticizer and then heating, but it is preferable to perform the method by heating alone. In addition, examples of the solvent include organic solvents that can dissolve the material to be emulsified, such as toluene, xylene, methylcyclohexane, and ethyl acetate.

[0065] The phase inversion emulsification method is a method in which component (A) is heated and melted, and then an emulsifier and water are added with 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, etc.

[0066] The concentration of the aqueous dispersion composition thus obtained is not particularly limited, but is usually adjusted appropriately so that the solid content is about 20 to 70 mass%. From the viewpoint of storage stability, the volume average particle size of the aqueous dispersion composition obtained is preferably less than about 0.7 μm. The aqueous dispersion composition obtained has a white to milky white appearance and a viscosity of usually about 10 to 1,000 mPa·s (temperature 25°C, concentration 50 mass%).

[0067] The pH of the aqueous dispersion composition obtained above is usually about 2 to 10. If necessary, the pH of the aqueous dispersion composition may be adjusted by appropriately 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.

[0068] [Tackifying resin water dispersion composition] The tackifier resin aqueous dispersion composition of the present invention includes the aqueous dispersion composition of the present invention. The aqueous dispersion composition of the present invention can function as a tackifier when used in a pressure-sensitive adhesive (including the aqueous pressure-sensitive adhesive composition described below).

[0069] [Water-based adhesive composition] The aqueous pressure-sensitive adhesive composition of the present invention comprises the aqueous dispersion composition of the present invention (or the aqueous dispersion composition of the tackifier resin of the present invention) and a base polymer. The aqueous pressure-sensitive adhesive composition of the present invention can be used as an aqueous pressure-sensitive adhesive. In this specification, it is clear that the term "adhesive" includes either or both of a pressure-sensitive adhesive and an adhesive.

[0070] Examples of the base polymer include acrylic polymer emulsion, rubber latex, and synthetic resin emulsion. The base polymer may be used alone or in combination of two or more. If necessary, a crosslinking agent, an antifoaming agent, a viscosity modifier, a filler, an antioxidant, a water-resistant agent, a film-forming assistant, a preservative, a pH adjuster such as aqueous ammonia or sodium bicarbonate, a leveling agent, a release adjuster, a plasticizer, a softener, a colorant (pigment, dye, etc.), a surfactant, an antistatic agent, an antiaging agent, an ultraviolet absorbing agent, a light stabilizer, etc. may also be used. A known water dispersion composition may also be used. The concentration of these water-based pressure-sensitive adhesive compositions is usually about 40 to 70 mass % in terms of solid content, and preferably 55 to 70 mass %.

[0071] The acrylic polymer emulsion may be one generally used in various aqueous pressure-sensitive adhesive compositions, such as an acrylic polymer of a monomer component containing alkyl (meth)acrylate. The acrylic polymer emulsion may be produced by various known emulsion polymerization methods, such as a batch polymerization method, a monomer stepwise addition polymerization method, an emulsion monomer stepwise addition polymerization method, or a seed polymerization method, in the presence of a polymerization initiator. The acrylic polymer emulsion may be used alone or in combination of two or more.

[0072] 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, s-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, and isooctyl (meth)acrylate. Examples of the alkyl (meth)acrylate include 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 can be used alone or in combination of two or more.

[0073] The monomer component in the acrylic polymer emulsion may further contain other monomers copolymerizable with the alkyl (meth)acrylate, such as carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, cyano group-containing monomers, keto group-containing monomers, monomers having a nitrogen atom-containing ring, alkoxysilyl group-containing monomers, and polyfunctional monomers.

[0074] 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, as well as their anhydrides (maleic anhydride, itaconic anhydride, etc.).

[0075] 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.

[0076] 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.

[0077] Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate.

[0078] 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 keto group-containing monomer include diacetone (meth)acrylamide, diacetone (meth)acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, and vinyl acetoacetate.

[0079] Examples of the monomer 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.

[0080] Examples of the alkoxysilyl group-containing monomer include 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane.

[0081] 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, glycerin di(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinylbenzene, butyl di(meth)acrylate, and hexyl di(meth)acrylate.

[0082] The content of other monomers copolymerizable with alkyl (meth)acrylate in the monomer component is not particularly limited, but is preferably about 40% by mass or less relative to 100% by mass of the monomer component.

[0083] The monomer components further include vinyl ester monomers such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene, substituted styrene (α-methylstyrene, etc.) and vinyl toluene; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate and isobornyl (meth)acrylate; aryl (meth)acrylates (e.g., phenyl (meth)acrylate), aryloxyalkyl (meth)acrylates (e.g., phenoxyethyl (meth)acrylate), arylalkyl ... The monomers may include aromatic ring-containing (meth)acrylates such as acrylates (e.g., benzyl (meth)acrylate); olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; chlorine-containing monomers such as vinyl chloride and vinylidene chloride; isocyanate group-containing monomers such as 2-(meth)acryloyloxyethyl isocyanate; alkoxy group-containing monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; 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 monomer components.

[0084] The polymerization initiator is not particularly limited, and examples thereof include azo-based 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; and 1,1-bis(t-hexylperoxy)-3,3,5-trimethylaminopropane. Examples of the polymerization initiator include peroxide initiators such as methylcyclohexane, t-hexyl peroxypivalate, t-butyl peroxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, benzoyl peroxide, t-butyl hydroperoxide, and hydrogen peroxide; and persulfate initiators such as potassium persulfate and ammonium persulfate. The polymerization initiator may be used alone or in combination of two or more.

[0085] The weight average molecular weight (Mw) of the acrylic polymer in the acrylic polymer emulsion is not particularly limited, but is usually in the range of about 100,000 to 5,000,000. 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 viewpoint of improving adhesive properties, and is preferably 200,000 or more, more preferably 300,000 or more from the viewpoint of cohesiveness, etc. In this specification, the weight average molecular weight refers to a polystyrene equivalent value in a gel permeation chromatography (GPC) method.

[0086] The content ratio of the acrylic polymer emulsion and the water-dispersed composition is not particularly limited, but an appropriate range in which the effect of the modification by the water-dispersed composition can be fully exhibited and which does not cause a decrease in heat resistance retention, tackiness, etc. due to excessive use is usually about 2 to 40 parts by mass of the water-dispersed composition per 100 parts by mass of the acrylic polymer emulsion, calculated as solid content.

[0087] As the rubber latex, various known latexes used in aqueous pressure-sensitive adhesive compositions can be used. Examples of the rubber latex include natural rubber latex and synthetic rubber latex. The natural rubber latex may be modified natural rubber obtained by grafting natural rubber with an alkyl (meth)acrylate ester or the like. The rubber latex may be used alone or in combination of two or more.

[0088] The above-mentioned synthetic rubber latex is an aqueous dispersion of synthetic polymers, and examples of synthetic polymers 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, reclaimed rubber, butyl rubber, polyisobutylene, styrene-butadiene-vinylpyridine rubber, polybutadiene, methyl methacrylate-butadiene rubber, acrylonitrile-butadiene rubber (NBR), polychloroprene (CR), and the like.

[0089] The content ratio of the rubber latex and the water-dispersed composition is not particularly limited, but as an appropriate range in which the effect of modification by the water-dispersed composition can be fully exhibited and the adhesive strength, tackiness, etc. are not reduced due to excessive use, it is usually preferable to use about 10 to 150 parts by mass of the water-dispersed composition per 100 parts by mass of the rubber latex in terms of solid content.

[0090] As the synthetic resin emulsion, various known emulsions used in aqueous pressure-sensitive adhesive compositions can be used, such as vinyl acetate emulsions, ethylene-vinyl acetate copolymer emulsions, urethane emulsions, etc. The synthetic resin emulsions may be used alone or in combination of two or more.

[0091] The content ratio of the synthetic resin emulsion and the water-dispersed composition is not particularly limited, but an appropriate range of use in which the effect of modifying the water-dispersed composition can be fully exhibited and a decrease in adhesive strength, tack, etc. due to excessive use is not caused, is usually about 2 to 40 parts by mass of the water-dispersed composition per 100 parts by mass of the synthetic resin emulsion, calculated as solid content.

[0092] The aqueous pressure-sensitive adhesive composition of the present invention may contain various additives, such as a crosslinking agent, an antifoaming agent, a viscosity modifier, a filler, a water-resistant agent, a film-forming aid, a preservative, a pH adjuster such as aqueous ammonia or sodium bicarbonate, a leveling agent, a release adjuster, a plasticizer, a softener, a colorant (pigment, dye, etc.), a surfactant, an antistatic agent, an antiaging agent, an ultraviolet absorber, an antioxidant, and a light stabilizer, as necessary, so long as the desired properties are not impaired.

[0093] Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, etc. The content of the crosslinking agent is not particularly limited, but is usually 20 parts by mass or less, preferably about 0.01 to 10 parts by mass, per 100 parts by mass of the base polymer.

[0094] Examples of the isocyanate-based 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 cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylene diisocyanate; aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate; and biuret, isocyanurate, allophanate, and adduct thereof, as well as complexes obtained by reacting two or more selected from the group consisting of biuret, isocyanurate, allophanate, and adduct.

[0095] Examples of the epoxy crosslinking agent include compounds having two or more epoxy groups in the molecule, such as bisphenol A epichlorohydrin type epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, diamine glycidylamine, N,N,N',N'-tetraglycidyl-m-xylylenediamine, and 1,3-bis(N,N'-diamineglycidylaminomethyl)cyclohexane.

[0096] The aqueous pressure-sensitive adhesive composition of the present invention can be obtained by mixing the aqueous dispersion composition and the base polymer, and, if necessary, various additives. The mixing method is not particularly limited, and various known methods can be used.

[0097] [Adhesive / bonding sheets] The adhesive sheet of the present invention comprises an adhesive layer made of the aqueous adhesive composition and a substrate. The adhesive sheet of the present invention may be an adhesive sheet with a substrate in which the adhesive layer is provided on one or both sides of the substrate, or may be an adhesive sheet without a substrate in which the adhesive layer is supported by a release liner (which may also be understood as a substrate having a release surface). The concept of the adhesive sheet here may include those referred to as adhesive tapes, adhesive labels, adhesive films, etc.

[0098] Examples of the substrate include 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 plastic films such as cellophane; Japanese paper, craft paper, glassine paper, wood-free paper, synthetic paper, top-coated paper, and other papers; cotton fiber, staple fiber, Manila hemp, pulp, rayon, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, polyolefin fiber, and other natural fibers, semi-synthetic fibers, and synthetic fibers, woven fabrics and nonwoven fabrics made by blending or the like; rubber sheets made of natural rubber, butyl rubber, and the like; foam sheets made of foams such as polyurethane foam and polychloroprene rubber foam; metal foils such as aluminum foil and copper foil; and composites thereof. The film may be either a non-stretched type or a stretched type (uniaxially stretched type or biaxially stretched type). The substrate may have a single layer form or a laminate form.

[0099] In addition, the base material may contain various additives such as fillers (inorganic fillers, organic fillers, etc.), antiaging agents, antioxidants, UV absorbers, lubricants, plasticizers, colorants (pigments, dyes, etc.), etc., as necessary.

[0100] The surface of the substrate (particularly the surface on the polymer layer side) may be subjected to an appropriate known or conventional surface treatment, for example, a physical treatment such as a corona discharge treatment or a plasma treatment, or a chemical treatment such as an undercoat treatment or a back surface treatment.

[0101] The adhesive sheet of the present invention can be produced by a known method. First, the aqueous adhesive composition is applied to one or both sides of a substrate to form a coating layer made of the aqueous adhesive composition. A known method can be applied as the coating method, and examples of the coating method include a roll coater method, a comma coater method, a die coater method, a reverse coater method, a silk screen method, and a gravure coater method. Next, the coating layer is heated or dried to form an adhesive layer made of the aqueous adhesive composition. The heating or drying conditions can be appropriately set depending on the thickness of the adhesive layer, and the temperature is, for example, 10 to 120°C, and the time is, for example, 0.1 to 10 hours. The thickness of the adhesive layer (thickness after drying) varies depending on the application, but is preferably 5 to 200 μm. EXAMPLES

[0102] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto. In the examples, "parts" and "%" are by weight unless otherwise specified.

[0103] <Measurement of weight average molecular weight (Mw)> The weight average molecular weight (Mw) of the rosin resins (A-1) to (A'-5) in Production Examples 2 to 10 was calculated as a polystyrene equivalent value obtained from a calibration curve of standard polystyrene by gel permeation chromatography (GPC). The GPC method was measured under the following conditions. Analytical equipment: HLC-8320 (Tosoh Corporation) Column: TSKgel SuperHM-L x 3 Eluent: Tetrahydrofuran Injection sample concentration: 5mg / mL Flow rate: 0.6mL / min Injection volume: 40μL Column temperature: 40℃ Detector: RI

[0104] <Content of components with weight average molecular weight (Mw) of 6,000 or more> The contents (mass%) of components having a weight average molecular weight (Mw) of 6,000 or more in the rosin-based resins (A-1) to (A'-5) in Production Examples 2 to 10 were calculated from the GPC charts obtained by the above method using the following formula.

[0105] Content (mass%) of components with a weight-average molecular weight (Mw) of 6,000 or more = [Peak area value (S2) of components with a weight-average molecular weight of 6,000 or more / Total peak area value (S1)] x 100

[0106] (Acid value and hydroxyl value) The acid value (mgKOH / g) and hydroxyl value (mgKOH / g) of the rosin resins (A-1) to (A'-5) in Production Examples 2 to 10 were measured according to JIS K0070.

[0107] <Production of base polymer> Manufacturing Example 1 A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen inlet tube was charged with 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.) under a nitrogen gas flow, and the temperature was raised to 70 ° C. Then, a mixture consisting of 90 parts of butyl acrylate, 7 parts of 2-ethylhexyl acrylate and 3 parts of acrylic acid, 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. for 30 minutes under a nitrogen gas flow. Next, the 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 mixture 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 through a 100 mesh wire screen to obtain an acrylic polymer emulsion with a solid content concentration of 47.8%.

[0108] <Production of rosin-based resin (A)> Manufacturing Example 2 A reaction vessel equipped with a stirrer, condenser, thermometer, nitrogen inlet tube, and water vapor inlet tube was 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 charged and melted at 220°C. Next, 12 parts of pentaerythritol were charged, and the temperature was raised to 250°C and reacted at the same temperature for 2 hours, and then the temperature was raised to 280°C and reacted at the same temperature for 7 hours. After that, the mixture was subjected to a reduced pressure treatment for 5 hours to obtain a polymerized rosin ester (A-1) (hereinafter referred to as component (A-1)) having a weight average molecular weight (Mw) of 2,200 and a content of components having a weight average molecular weight (Mw) of 6,000 or more of 6%. The component (A-1) had an acid value of 6 mgKOH / g and a hydroxyl value of 45 mgKOH / g.

[0109] Production Example 3 In a reaction vessel similar to that of 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 charged and melted at 220°C. Next, 11 parts of pentaerythritol were charged, and the temperature was raised to 250°C and reacted at the same temperature for 2 hours. The temperature was further raised to 280°C and reacted at the same temperature for 7 hours to complete the esterification. After that, the mixture was subjected to a reduced pressure treatment for 5 hours to obtain a polymerized rosin ester (A-2) (hereinafter referred to as component (A-2)) having a weight average molecular weight (Mw) of 2,000 and a content of components having a weight average molecular weight (Mw) of 6,000 or more of 4%. The component (A-2) had an acid value of 7 mgKOH / g and a hydroxyl value of 24 mgKOH / g.

[0110] Production Example 4 In a reaction vessel similar to that of 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 charged and melted at 220°C. Next, 11 parts of pentaerythritol were charged, and the temperature was raised to 250°C and reacted at the same temperature for 2 hours. The temperature was further raised to 280°C and reacted at the same temperature for 7 hours. After that, the mixture was subjected to a reduced pressure treatment for 5 hours to obtain a polymerized rosin ester (A-3) (hereinafter referred to as component (A-3)) having a weight average molecular weight (Mw) of 1,600 and a content of components having a weight average molecular weight (Mw) of 6,000 or more of 2%. The component (A-3) had an acid value of 10 mgKOH / g and a hydroxyl value of 35 mgKOH / g.

[0111] Production Example 5 In a reaction vessel similar to that of 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 charged and melted at 220°C. Next, 12 parts of pentaerythritol were charged, and the temperature was raised to 250°C and reacted at the same temperature for 2 hours. The temperature was further raised to 280°C and reacted at the same temperature for 7 hours. After that, the mixture was subjected to a reduced pressure treatment for 5 hours to obtain a polymerized rosin ester (A-4) (hereinafter referred to as component (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 more of 9%. The component (A-4) had an acid value of 6 mgKOH / g and a hydroxyl value of 30 mgKOH / g.

[0112] Production Example 6 In a reaction vessel similar to that of Production Example 2, 100 parts of polymerized rosin (acid value 145 mgKOH / g, softening point 140°C) was charged and melted at 220°C. Next, 11 parts of pentaerythritol was charged, and the temperature was raised to 250°C and reacted at the same temperature for 2 hours. The temperature was further raised to 280°C and reacted at the same temperature for 9 hours to complete esterification. After that, the mixture was subjected to a reduced pressure treatment for 2 hours to obtain a polymerized rosin ester (A'-1) (hereinafter referred to as component (A'-1)) having a weight average molecular weight (Mw) of 2,600 and a content of components having a weight average molecular weight (Mw) of 6,000 or more at 10%. The component (A'-1) had an acid value of 12 mgKOH / g and a hydroxyl value of 40 mgKOH / g.

[0113] Production Example 7 In a reaction vessel similar to that of Production Example 2, 100 parts of polymerized rosin (acid value 145 mgKOH / g, softening point 140°C) was charged and melted at 220°C. Next, 12 parts of pentaerythritol was charged, and the temperature was raised to 250°C and reacted at the same temperature for 2 hours. The temperature was further raised to 280°C and reacted at the same temperature for 14 hours. After that, the mixture was subjected to a reduced pressure treatment for 3 hours to obtain a polymerized rosin ester (A'-2) (hereinafter referred to as component (A'-2)) having a weight average molecular weight (Mw) of 3,200 and a content of components having a weight average molecular weight (Mw) of 6,000 or more of 15%. The component (A'-2) had an acid value of 7 mgKOH / g and a hydroxyl value of 40 mgKOH / g.

[0114] Production Example 8 In a reaction vessel similar to that of Production Example 2, 100 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) was charged and melted at 130°C. Then, 22 parts of maleic anhydride were charged and heated to 170°C, 25 parts of pentaerythritol were charged, and the temperature was raised to 220°C. The mixture was reacted at the same temperature for 7 hours to obtain a maleic rosin ester (A'-3) (hereinafter referred to as component (A'-3)) having a weight average molecular weight (Mw) of 1,500 and a content of components having a weight average molecular weight (Mw) of 6,000 or more at 6%. The acid value of component (A'-3) was 130 mgKOH / g.

[0115] Production Example 9 In a reaction vessel similar to that of Production Example 2, 100 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) was charged and melted at 170°C. Next, 20 parts of fumaric acid was charged, and the temperature was raised to 220°C, and the reaction was carried out at the same temperature for 2 hours. After that, 7 parts of glycerin was charged, and the temperature was raised to 210°C, and the reaction was carried out at the same temperature for 3 hours to obtain a fumarated rosin ester (A'-4) (hereinafter referred to as component (A'-4)) having a weight average molecular weight (Mw) of 1,100 and a content of components having a weight average molecular weight (Mw) of 6,000 or more of 3%. The acid value of component (A'-4) was 190 mgKOH / g.

[0116] Manufacturing Example 10 In a reaction vessel similar to that of Production Example 2, 100 parts of rosin (acid value 170 mgKOH / g, softening point 80°C) was charged and melted at 170°C. Next, 10 parts of maleic anhydride and 18 parts of glycerin were charged, and the temperature was raised to 270°C, and the mixture was reacted at the same temperature for 1 hour. After that, the mixture was subjected to a reduced pressure treatment for 1 hour, thereby obtaining a maleic rosin ester (A'-5) (hereinafter referred to as component (A'-5)) having a weight average molecular weight (Mw) of 3,200 and a content of components having a weight average molecular weight (Mw) of 6,000 or more of 17%. The acid value of component (A'-5) was 23 mgKOH / g.

[0117] <Production of emulsifier (B)> Manufacturing Example 11 In a four-neck flask equipped with a nitrogen gas inlet tube, a thermometer, a reflux condenser, and a stirrer, 30 parts of methyl acrylate, 12 parts of methyl methacrylate, 30 parts (solid content equivalent) of a polyoxyethylene phenyl ether-based reactive emulsifier (trade name "Aqualon RN-20", manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 15 parts of sodium styrenesulfonate, and 13 parts of styrene were charged, and 10 parts of ion-exchanged water was further added to obtain 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 the aqueous monomer solution. Next, the reaction system was heated to 85°C and held for 2 hours to carry out a radical polymerization reaction. Next, 1 part of ammonium persulfate was added to the reaction system, and the system was further kept warm for 1 hour. Then, 14 parts of a 48% aqueous sodium hydroxide solution was added to the reaction system, which was then thoroughly stirred and cooled to room temperature. In this way, an aqueous solution of high molecular weight emulsifier (B-1) (hereinafter referred to as component (B-1)) with a solid content of 21.0% was obtained.

[0118] Manufacturing Example 12 In a reaction vessel similar to that of 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-dodecyl mercaptan as a chain transfer agent were charged, and the mixture was heated to 80°C while stirring under nitrogen gas bubbling. 5 parts of ammonium persulfate (APS) were added as a polymerization initiator, and the mixture was heated to 90°C and maintained for 120 minutes. Then, 17.7 parts of 48% aqueous sodium hydroxide solution and a predetermined amount of ion-exchanged water were added to the reaction system, which was then thoroughly stirred and cooled to room temperature. Thus, an aqueous solution of a high molecular weight emulsifier (B-2) (hereinafter referred to as the (B-2) component) with a solid content of 23.0% was obtained.

[0119] [Production of Water-Dispersed Composition] Example 1 100 parts of the (A-1) component of Production Example 2 was dissolved in 80 parts of methylcyclohexane at 80°C for 3 hours, and then 3 parts of the (B-1) component (solid content equivalent) and 140 parts of water were added and stirred for 1 hour. Next, the mixture was emulsified at a pressure of 30 MPa using a high-pressure emulsifier (manufactured by Manton Gaulin) to obtain an emulsion. Then, the mixture was mixed at 70°C with 2.93 x 10-2 MPa for 6 hours to obtain a water-dispersed composition with a solid content of 50%.

[0120] Examples 2 to 4 The same procedure as in Example 1 was carried out except that the component (A-1) in Example 1 was changed to the components (A-2) to (A-4), to obtain a water-dispersed composition with a solid content concentration of 50%.

[0121] Example 5 The same procedure as in Example 1 was carried out except that the component (B-1) in Example 1 was changed to the component (B-2), to obtain a water-dispersed composition with a solid content concentration of 50%.

[0122] Example 6 The same procedure as in Example 1 was carried out, except that in Example 1, the (B-1) component was changed to 3 parts (solid content equivalent) of disodium polyoxyethylene alkyl (carbon number: 12 to 14) sulfosuccinate (hereinafter referred to as (B-3) component), to obtain a water-dispersed composition with a solid content concentration of 50%.

[0123] Comparative Examples 1 to 5 The same procedure as in Example 1 was carried out except that the component (A-1) in Example 1 was changed to the components (A'-1) to (A'-5), to obtain a water-dispersed composition with a solid content concentration of 50%.

[0124] (Evaluation of emulsifying properties) The volume average particle size of the water-dispersed composition of each of the Examples and Comparative Examples was measured using a laser diffraction particle size measuring device (manufactured by Shimadzu Corporation, product name "SALD-7500nano") under conditions of a refractive index of 1.70-0.20i and an absorbance of 0.06. The obtained volume average particle sizes were evaluated according to the following criteria. The results are shown in Table 1. The smaller the volume average particle size, the better the emulsifiability and storage stability of the water-dispersed composition. ○: Volume average particle size less than 0.5 μm △: Volume average particle size 0.5 μm or more and less than 0.7 μm ×: Volume average particle size 0.7 μm or more

[0125] In addition, the aqueous dispersion composition of each Example and Comparative Example was filtered through a 150 mesh wire screen, and the weight % of the resulting residue relative to the rosin-based resin (A) was weighed. The weight % of the residue was evaluated according to the following criteria. The results are shown in Table 1. The smaller the weight % of the residue, the more the generation of aggregates in the aqueous dispersion composition is suppressed, and the better its emulsifiability. ○: Less than 0.1% by weight △: 0.1% by weight or more and less than 0.5% by weight ×: 0.5% by weight or more

[0126] [Production of Water-Based Pressure-Sensitive Adhesive Composition] An aqueous pressure-sensitive adhesive composition was obtained by mixing 90 parts (solid content equivalent) of the acrylic polymer emulsion synthesized in Production Example 1 and 10 parts (solid content equivalent) of the aqueous dispersion composition of Example 1. For each of the aqueous dispersion compositions of Examples 2 to 6 and Comparative Examples 1 to 5, an aqueous pressure-sensitive adhesive composition was similarly produced.

[0127] [Creating sample tapes] Using a dice-shaped applicator (manufactured by Taiyu Kizai Co., Ltd.), the above aqueous pressure-sensitive adhesive composition was applied to a polyester film (product name "S-100", manufactured by Mitsubishi Chemical Corporation, thickness: 38 μm) to a thickness of about 50 μm, and then dried for 5 minutes in a circulating air dryer at 105°C to prepare a sample tape.

[0128] (Evaluation of constant load peeling) The above sample tape was cut to a width of 25 mm, and was laminated to an adherend (polyethylene plate (PE)) by rolling it back and forth twice with a 2 kg roller, and was left to stand for one day. Next, a load of 200 g was applied to the end of the tape, and the tape was fixed so as to peel at a 90° angle, and the peel distance (mm) per hour was measured 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 adhesive strength of the aqueous pressure-sensitive adhesive composition. ◎: Peel distance per hour is less than 20 mm ○: Peel distance per hour is 20mm or more and less than 30mm △: Peeling distance per hour is 30mm or more and less than 50mm ×: Peel distance per hour is 50 mm or more

[0129] [Table 1] The notes in Table 1 are as follows: *The content (mass%) of components with a weight average molecular weight of 6,000 or more in component (A).

Claims

1. The present invention comprises a rosin-based resin (A) having a weight average molecular weight of 2,000 to 3,000 and an emulsifier (B), 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, The rosin-based resin (A) has an acid value of 5 to 10 mgKOH / g; the rosin-based resin (A) is a polymerized rosin ester, The emulsifier (B) is at least one selected from the group consisting of high molecular weight emulsifiers and low molecular weight anionic emulsifiers. Water-dispersed compositions (but not including petroleum resins).

2. A tackifier resin water-dispersed composition comprising the water-dispersed composition of claim 1.

3. An aqueous pressure-sensitive adhesive composition comprising the aqueous dispersion composition according to claim 1 and a base polymer.

4. The aqueous pressure-sensitive adhesive composition according to claim 3, wherein the base polymer is an acrylic polymer emulsion.

5. An adhesive sheet comprising an adhesive layer comprising the aqueous adhesive composition according to claim 3 or 4, and a substrate.

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