Water-based resin dispersion compositions, coating compositions, adhesive compositions, ink compositions

Abstract

An object of the present invention is to provide an aqueous resin dispersion composition which is capable of forming a coating film having excellent adhesion to a polyolefin substrate and which also has excellent film-forming properties. [Solution] The aqueous resin dispersion composition of the present invention contains an aqueous resin dispersion (I) containing an olefin resin (A) having a complex viscosity of more than 1,500 Pa·s at 200°C and 0.1 Hz, and an aqueous resin dispersion (II) containing an olefin resin (B) having a complex viscosity of 1,500 Pa·s or less at 180°C and 0.1 Hz.

Description

[Technical Field]

[0001] The present invention relates to an aqueous resin dispersion composition, a coating composition, an adhesive composition, and an ink composition. [Background technology]

[0002] In recent years, environmentally friendly resin compositions have been attracting attention. In particular, water-dispersed resin compositions that do not contain solvents have been attracting attention. In particular, solvent-free resin compositions have been studied in the field of paints. On the other hand, polyolefins, such as polypropylene and copolymers of propylene with other α-olefins, which are the materials to be coated, are used in a wide range of fields due to their excellent mechanical properties, heat resistance, chemical resistance, water resistance, etc. However, when forming a coating on polyolefins, adhesion of the coating can be difficult due to the low polarity of polyolefins.

[0003] Known methods for improving adhesion to polyolefins include chemically treating the surface of polyolefins with chemicals, etc., and oxidizing the surface by corona discharge treatment, plasma treatment, flame treatment, etc. However, these methods require special equipment and have the problem that the effect of improving adhesion is not sufficient. On the other hand, paints containing modified olefin resins such as chlorinated polyolefins, acid-modified polyolefins, acid-modified chlorinated polyolefins, etc. are known as paints with improved adhesion to polyolefins. Such paints include solvent-based paints in which the modified olefin resin is dissolved in an organic solvent, and water-based paints in which the modified olefin resin is dispersed in an aqueous medium, but water-based paints are preferred from the standpoints of safety and hygiene and reducing environmental pollution.

[0004] However, since the performance of water-based paints containing modified olefin resins is insufficient, further improvements have been attempted. For example, Patent Document 1 discloses an aqueous resin dispersion that uses a specific propylene polymer having a low melting point and a low molecular weight in combination with a specific propylene polymer having a high melting point and a high molecular weight that has also been modified with an unsaturated organic acid derivative. Patent Document 2 discloses the use of a composite resin of an acrylic resin modified with a specific radical polymerizable monomer and an olefin resin. Patent Document 3 discloses an aqueous dispersion composition containing a modified polyolefin, a polyolefin different from the modified polyolefin, a tackifier, and an epoxy resin. Patent Document 4 discloses an aqueous coating composition containing an olefin resin and a hydroxyl group-containing resin having a specific hydroxyl group. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-031360 [Patent Document 2] International Publication No. 2017 / 213192 [Patent Document 3] International Publication No. 2019 / 181336 [Patent Document 4] Japanese Patent Application Publication No. 2019-210308 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is room for further improvement in the adhesion to polyolefin substrates of the conventional products such as those disclosed in Patent Documents 1, 2, 3, and 4. In addition, they are unable to satisfy both film-forming properties and adhesion properties.

[0007] An object of the present invention is to provide an aqueous resin dispersion composition capable of forming a coating film having excellent adhesion to a polyolefin substrate. [Means for solving the problem]

[0008] The present inventors have conceived of having an aqueous resin dispersion containing a high melt viscosity olefin resin and an aqueous resin dispersion containing a low melt viscosity olefin resin present independently in an aqueous resin dispersion composition. The present inventors have found that by employing such a technical means, the film-forming properties of olefin resin particles are improved due to the film strength provided by the high melt viscosity olefin resin, and that the low melt viscosity olefin resin fills in the gaps between the high melt viscosity olefin resin, thereby improving adhesion, and have completed the present invention.

[0009] The present invention has the following aspects. [1] An aqueous resin dispersion (I) containing an olefin resin (A) having a complex viscosity of more than 1,500 Pa·s at 200°C and 0.1 Hz; an aqueous resin dispersion (II) containing an olefin resin (B) having a complex viscosity of 1,500 Pa s or less at 180°C and 0.1 Hz; An aqueous resin dispersion composition comprising: [2] The aqueous resin dispersion composition according to [1], wherein the mass ratio of the olefin resin (A) to the olefin resin (B) is 50 / 50 to 85 / 15. [3] The aqueous resin dispersion composition according to [1] or [2], wherein the proportion of propylene-derived structural units among the olefin-derived structural units of the olefin-based resin (A) and the olefin-based resin (B) is 50 mol % or more. [4] The aqueous resin dispersion composition according to any one of [1] to [3], wherein the aqueous resin dispersion (I) has an average particle size of 500 nm or less. [5] The aqueous resin dispersion composition according to any one of [1] to [4], wherein the aqueous resin dispersion (II) has an average particle size of 500 nm or less. [6] A coating composition containing the aqueous resin dispersion composition according to any one of [1] to [5]. [7] An adhesive composition comprising the aqueous resin dispersion composition according to any one of [1] to [5]. [8] An ink composition comprising the aqueous resin dispersion composition according to any one of [1] to [5]. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an aqueous resin dispersion composition that can form a coating film having excellent adhesion to a polyolefin substrate and also has excellent film-forming properties. DETAILED DESCRIPTION OF THE INVENTION

[0011] As used herein, the following terms have the following meanings: "(Meth)acrylic acid" is a general term for acrylic acid and methacrylic acid. The term "dispersion" refers to a substance containing an olefin resin in a dispersed state and water, a solvent other than water, or a mixed solvent thereof. The term "dispersed state" means that the olefin resin is present in the form of particles without being dissolved in water, a solvent other than water, or a mixed solvent thereof. The "copolymer" may be a random copolymer or a block copolymer. The term "integrated" means that multiple resins having different structures are bonded together by chemical interactions (for example, covalent bonds), physical interactions (for example, intermolecular forces), or mechanical interactions. The symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0012] [Aqueous resin dispersion composition] The aqueous resin dispersion composition of the present invention contains an aqueous resin dispersion (I) containing an olefin resin (A) having a complex viscosity of more than 1,500 Pa s at 200°C and 0.1 Hz, and an aqueous resin dispersion (II) containing an olefin resin (B) having a complex viscosity of 1,500 Pa s or less at 180°C and 1.0 Hz.

[0013] In the aqueous resin dispersion composition of the present invention, the aqueous resin dispersion (I) and the aqueous resin dispersion (II) described below exist independently, and therefore a coating film having excellent adhesion to polyolefin substrates can be formed. Here, "the aqueous resin dispersion (I) and the aqueous resin dispersion (II) exist independently" means that particles containing the olefin resin (A) and particles containing the olefin resin (B) exist as separate particles. The particles containing the olefin resin (A) and the particles containing the olefin resin (B) do not exist as identical particles chemically or physically, but exist independently.

[0014] (Water-based resin dispersion (I)) The aqueous resin dispersion (I) contains an olefin resin (A) in a dispersed state. The content of the olefin resin (A) in the aqueous resin dispersion (I) is preferably 5 to 80 mass %, more preferably 10 to 60 mass %, and even more preferably 20 to 50 mass %.

[0015] The olefin resin (A) is a resin having structural units derived from an olefin. Examples of the olefin include ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, cyclopentene, cyclohexene, and norbornene. One type of olefin may be used alone, or two or more types may be used in combination.

[0016] The proportion of the olefin-derived structural units is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more of the total number of moles of structural units constituting the olefin-based resin (A). The higher the proportion of the olefin-derived structural units, the more likely it is that the adhesion to polyolefin substrates will improve.

[0017] The olefin resin (A) may be linear or branched. From the viewpoint of adhesion to polyolefin substrates, the olefin resin (A) preferably contains a propylene polymer having structural units derived from propylene, and more preferably contains an ethylene-propylene copolymer, an ethylene-propylene-butene copolymer, or a propylene-butene copolymer. The proportion of structural units derived from propylene in the propylene polymer is preferably 50 mol % or more, more preferably 60 mol % or more, and even more preferably 70 mol % or more of all structural units derived from olefin in the olefin resin (A).

[0018] The olefin resin (A) may be a chlorinated polyolefin obtained by chlorinating an olefin resin. In this case, the chlorination degree of the chlorinated polyolefin is preferably 40% by mass or less, more preferably 30% by mass or less.

[0019] Examples of the olefin-based resin (A) include an olefin homopolymer (hereinafter referred to as "olefin-based homopolymer (A1)"), a copolymer of an olefin with another monomer copolymerizable with the olefin (hereinafter referred to as "olefin-based copolymer (A2)"), and an olefin-based composite resin (A3).

[0020] The olefin homopolymer (A1), the olefin copolymer (A2), and the olefin composite resin (A3) may have a group reactive with an amino group, such as a carboxy group, an epoxy group, an isocyanato group, a sulfonic acid group, or a hydroxyl group. The reactive group may be an acid anhydride structure of a carboxy group.

[0021] As the olefin resin (A), an olefin resin (A) having a reactive group is more preferred in terms of excellent compatibility with the olefin resin (B) and excellent water-resistant adhesion. Hereinafter, the olefin homopolymer (A1) having a reactive group will be referred to as "polymer (A11)", the olefin copolymer (A2) having a reactive group will be referred to as "polymer (A21)", and the olefin composite resin (A3) having a reactive group will be referred to as "polymer (A31)".

[0022] Examples of the olefin copolymer (A2) include a copolymer of ethylene and propylene; a copolymer of at least one of ethylene and propylene with a monomer copolymerizable with ethylene and propylene (for example, an α-olefin having 4 or more carbon atoms, such as butene-1, pentene-1, hexene-1, heptene-1, octene-1, cyclopentene, cyclohexene, or norbornene); a copolymer of two or more α-olefins selected from the group consisting of the α-olefins having 4 or more carbon atoms; Copolymers of α-olefins having two or more carbon atoms and non-aromatic monomers other than α-olefins, such as vinyl acetate, acrylic esters, and methacrylic esters; Copolymers of α-olefins having two or more carbon atoms and aromatic monomers such as aromatic vinyl monomers, or hydrogenated copolymers thereof; Conjugated diene block copolymers or hydrogenated products thereof are exemplified. Two or more types of comonomers other than olefins may be used.

[0023] Examples of the olefin composite resin (A3) include composite resin (a31) in which at least one resin selected from the group consisting of olefin homopolymer (A1) and olefin copolymer (A2) is integrated with a resin having a structure different from that of the above resin, and composite resin (a32) in which the above composite resin (a31) is further integrated with a resin having a structure different from that of the above composite resin (a31). It is preferable that a plurality of resins having different structures are integrated to form a graft polymer, a core-shell structure, a microphase-separated structure, an interpenetrating polymer network structure, or the like.

[0024] The melting point (hereinafter referred to as "Tm") of the olefin resin (A) is preferably 125°C or lower, more preferably 100°C or lower, and even more preferably 90°C or lower. The Tm of the olefin resin (A) is preferably 60°C or higher. The higher the Tm of the olefin resin (A), the less sticky the resin becomes. The lower the Tm of the olefin resin (A), the lower the drying and baking temperatures. The Tm of the olefin resin (A) can be measured using a differential scanning calorimeter "DSCEXSTAR6000" manufactured by Hitachi High-Tech Science Corporation.

[0025] The weight average molecular weight (hereinafter referred to as "Mw") of the olefin resin (A) is measured by Gel Permeation Chromatography (GPC). The GPC measurement is carried out after preparing an aqueous dispersion and vacuum drying it at 40°C for 12 hours. The measurement is carried out by a conventional method using a commercially available apparatus and a solvent such as orthodichlorobenzene or tetrahydrofuran.

[0026] The Mw of the olefin resin (A) is preferably more than 200,000 and not more than 2,000,000. The lower limit of the Mw of the olefin resin (A) is more preferably 230,000, and even more preferably 250,000. The upper limit of the Mw of the olefin resin (A) is more preferably 1,000,000, and even more preferably 500,000. The higher the Mw of the olefin resin (A), the better the durability of the coating film. The lower the Mw of the olefin resin (A), the better the film-forming properties of the coating film and the better its adhesion to the substrate. In addition, the viscosity is lower, making it easier to prepare an aqueous resin dispersion.

[0027] The complex viscosity of the olefin resin (A) at 200°C and 0.1 Hz is greater than 1,500 Pa·s. The complex viscosity of the olefin resin (A) at 200°C and 0.1 Hz is preferably 1,500 Pa·s or greater, more preferably 2,000 Pa·s or greater, even more preferably 3,000 Pa·s or greater, and particularly preferably 4,500 Pa·s or greater. The complex viscosity of the olefin resin (A) at 200°C and 0.1 Hz is preferably 30,000 Pa·s or less, more preferably 15,000 Pa·s or less, and even more preferably 10,000 Pa·s or less. The complex viscosity is measured using a rheometer at 200°C and 0.1 Hz after the aqueous dispersion containing the olefin resin (A) is vacuum dried at 40°C for 12 hours.

[0028] The melt flow rate (MFR) of the olefin resin (A) is preferably less than 20 g / 10 min at 230° C. under a load of 2.16 kg, more preferably less than 10 g / 10 min, and even more preferably less than 8 g / 10 min. The lower limit of the MFR of the olefin resin (A) is usually about 0.1 g / 10 min. The MFR of the olefin resin (A) is measured by the method of ASTM D1238.

[0029] The olefin resin (A) can be produced, for example, by polymerizing an olefin by a method such as radical polymerization, cationic polymerization, anionic polymerization, coordination polymerization, etc. Each of these polymerizations may be living polymerization.

[0030] Catalysts used in coordination polymerization include Ziegler-Natta catalysts and single-site catalysts. Generally, single-site catalysts can achieve sharp molecular weight and stereoregularity distributions through ligand design. Examples of single-site catalysts include metallocene catalysts and Brookhart catalysts. Examples of metallocene catalysts include C1 symmetric, C2 symmetric, C2V symmetric, and CS symmetric. An appropriate catalyst can be selected from these depending on the stereoregularity of the desired polyolefin.

[0031] The polymerization method may be any of solution polymerization, slurry polymerization, bulk polymerization, gas phase polymerization, etc. In the case of solution polymerization or slurry polymerization, examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, heptane, and octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, halogenated hydrocarbons, esters, ketones, and ethers. Among these, aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbons are preferred, and toluene, xylene, heptane, and cyclohexane are more preferred. One solvent may be used alone, or two or more solvents may be used in combination.

[0032] The olefin resin (A) having a reactive group can be produced, for example, by graft polymerizing a radically polymerizable monomer having a reactive group onto an olefin resin. The radically polymerizable monomer having a reactive group is preferably a radically polymerizable monomer having a carboxyl group or an anhydride structure thereof. Examples of the radically polymerizable monomer include (meth)acrylic acid, fumaric acid, maleic acid and its anhydride, itaconic acid and its anhydride, and crotonic acid. The radical polymerizable monomer having a reactive group may be used alone or in combination of two or more kinds, and the olefin resin used in the graft polymerization may be used alone or in combination of two or more kinds.

[0033] The radical polymerization initiator used in the graft polymerization can be appropriately selected from known radical polymerization initiators such as organic peroxides and azonitrile.

[0034] Examples of organic peroxides include peroxyketals such as di(t-butylperoxy)cyclohexane, hydroperoxides such as cumene hydroperoxide, dialkyl peroxides such as di(t-butyl)peroxide, diacyl peroxides such as benzoyl peroxide, and peroxyesters such as t-butylperoxyisopropyl monocarbonate. One type of organic peroxide may be used alone, or two or more types may be used in combination. Examples of azonitriles include azobisbutyronitrile and azobisisopropylnitrile. One azonitrile may be used alone, or two or more azonitriles may be used in combination.

[0035] As the radical polymerization initiator, for example, benzoyl peroxide and t-butylperoxyisopropyl monocarbonate are preferred. The radical polymerization initiators may be used alone or in combination of two or more.

[0036] The ratio of the radical polymerization initiator to the radical polymerizable monomer to be grafted is preferably radical polymerization initiator:radical polymerizable monomer=1:100 to 2:1 (molar ratio), more preferably 1:20 to 1:1. The reaction temperature during graft polymerization is preferably 50° C. or higher, more preferably in the range of 80 to 200° C. The reaction time for graft polymerization is preferably 2 to 20 hours.

[0037] The olefin resin (A) having a reactive group may be produced by a method other than graft polymerization, for example, the following method. A method in which olefin resin and radical polymerizable monomer are reacted by heating and stirring in a solution. A method of reaction by melting, heating and stirring without using a solvent. - A method in which the material is heated and kneaded in an extruder to react. When the resin is produced in a solution, the same solvents as those explained in the production method of the olefin resin (A) by solution polymerization can be used.

[0038] As the olefin resin (A) having a reactive group, a propylene polymer having a reactive group is preferred from the viewpoint of adhesion to a polypropylene substrate. Examples of propylene polymers having a reactive group include maleic anhydride-modified polypropylene, maleic anhydride-modified ethylene-propylene copolymer, maleic anhydride-modified propylene-butene copolymer, acrylic acid-modified polypropylene, acrylic acid-modified ethylene-propylene copolymer, acrylic acid-modified propylene-butene copolymer, and chlorinated products thereof.

[0039] When the olefin resin (A) has a reactive group, the content of the reactive group per 1 g of the olefin resin (A) is preferably 0.01 to 1 mmol / g, more preferably 0.05 to 0.5 mmol / g or more, and even more preferably 0.1 to 0.3 mmol / g.

[0040] When the reactive group is an acidic group such as a carboxyl group or its anhydride, or a sulfonic acid group, the higher the content of the reactive group, the higher the acid value of the olefin resin (A). This tends to improve mechanical stability and improve the polymerization of radically polymerizable monomers during production. The lower the content of acidic groups, the higher the adhesion of the coating film to polyolefin substrates. The acid value of the olefin resin (A) can be adjusted by the content of acidic groups.

[0041] Neutralizing the acidic groups with a basic compound tends to improve the mechanical stability of the olefinic resin (A). Examples of basic compounds include inorganic bases such as sodium hydroxide and potassium hydroxide, ammonia, triethylamine, diethylamine, ethanolamine, dimethylethanolamine, 2-methyl-2-aminopropanol, triethanolamine, morpholine, and pyridine. The neutralization rate of the acidic groups is not particularly limited as long as dispersibility in water is obtained, but is preferably 1 to 100 mol%, and more preferably 50 mol% or more. The higher the neutralization rate, the more the dispersibility of the olefinic resin (A) in water tends to improve.

[0042] The olefin resin (A) is preferably an olefin composite resin (A3). As the olefin composite resin (A3), preferred are composite resins (a31) in which at least one resin selected from the group consisting of olefin homopolymers (A1) and olefin copolymers (A2) is integrated with a hydrophilic polymer such as a polyether resin, and composite resins (a32) in which the composite resin (a31) is integrated with a polymer having a structural unit derived from a radically polymerizable monomer having a reactive group.

[0043] Examples of the radically polymerizable monomer having a reactive group used in the composite resin (a32) obtained by integrating a polymer having a structural unit derived from a radically polymerizable monomer having a reactive group into the composite resin (a31) include hydroxyl group-containing radically polymerizable monomers such as 3-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxybutyl methacrylate, polypropylene glycol acrylate, and polypropylene glycol methacrylate, and epoxy group-containing radically polymerizable monomers such as glycidyl methacrylate and 4-hydroxybutyl acrylate glycidyl ether. 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, and glycidyl methacrylate are preferred because of their excellent adhesion to polyolefin substrates.

[0044] When the olefin composite resin (A3) has hydroxyl groups, the hydroxyl value of the olefin composite resin (A3) is preferably 0.01 to 100 mgKOH / g, more preferably 0.05 to 80 mgKOH / g, and even more preferably 0.1 to 50 mgKOH / g. The smaller the hydroxyl value, the more likely the adhesion to polypropylene substrates is improved. The hydroxyl value is calculated using the following formula 1. Hydroxyl value (mgKOH / g) = (f × M1 / Mw / M2 × [KOH] × 1,000) f: number of hydroxyl groups in hydroxyl-containing monomers Equation 1 In Formula 1, [KOH] is the molecular weight of KOH, M1 is the mass (g) of the hydroxyl group-containing monomer, M2 is the mass (g) of the solid content of the olefin composite resin (A3), and Mw is the molecular weight (number average molecular weight) of the hydroxyl group-containing monomer.

[0045] When the reactive group is a hydroxyl group, the content of the polymer having a structural unit derived from a radically polymerizable monomer having a reactive group is preferably 0.01 to 50 mass%, more preferably 0.05 to 40 mass%, and even more preferably 0.1 to 30 mass%, of the total mass of the olefin composite resin (A3). The smaller this content, the better the adhesion to the polyolefin substrate tends to be. The higher this content, the better the water resistance tends to be.

[0046] When the resin has an epoxy group as the reactive group, the content of the polymer having a structural unit derived from a radically polymerizable monomer having a reactive group is preferably 0.01 to 50 mass% of the total mass of the olefin composite resin (A3), more preferably 0.05 to 40 mass%, and even more preferably 0.1 to 30 mass%. The smaller this content, the better the adhesion to the polyolefin substrate tends to be. The higher this content, the better the water resistance tends to be.

[0047] A polymer having a structural unit derived from a radically polymerizable monomer having a reactive group may contain a structural unit derived from a vinyl-based monomer, since this has excellent polymerizability with the radically polymerizable monomer having a reactive group. Examples of the vinyl-based monomer include (meth)acrylic monomers such as (meth)acrylic acid and (meth)acrylic acid esters; aromatic monomers such as styrene and α-methylstyrene; amide monomers such as (meth)acrylamide and dimethyl(meth)acrylamide; (meth)acrylonitrile, vinyl acetate, vinyl propionate, and vinyl versatate.

[0048] Among these, (meth)acrylic monomers and aromatic monomers are preferred in terms of weather resistance and solvent resistance. Examples of (meth)acrylic monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, (meth)acrylic acid esters having an aryl group or an aralkyl group having 6 to 12 carbon atoms, Examples of the aromatic monomer include benzyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-aminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, an adduct of (meth)acrylic acid and polyethylene oxide, a (meth)acrylic acid ester having an alkyl group having 1 to 20 carbon atoms and containing a fluorine atom, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, and 2-perfluoroethylethyl (meth)acrylate. Examples of the aromatic monomer include styrene and α-methylstyrene.

[0049] The method for producing the olefin composite resin (A3) is not particularly limited, and examples thereof include the following methods. A method for polymerizing a radically polymerizable monomer in an aqueous dispersion of an olefin homopolymer (A1), an olefin copolymer (A2), or a composite resin (a31) to integrate a polymer containing a structural unit derived from the radically polymerizable monomer. A method in which an olefin homopolymer (A1), an olefin copolymer (A2) or a composite resin (a31) and a radical polymerizable monomer are dispersed in an aqueous medium to form an aqueous resin dispersion, and then the radical polymerizable monomer is polymerized to integrate them. From the viewpoint of the polymerizability of the radical polymerizable monomer, the former method is preferred.

[0050] A preferred method for producing the olefin composite resin (A3) is, for example, the following method. A method in which 80 to 100 mass % of a radical polymerizable monomer and a vinyl monomer are supplied all at once to an aqueous dispersion of an olefin homopolymer (A1), an olefin copolymer (A2) or a composite resin (a31), and polymerization is carried out using a water-soluble initiator. A method of polymerization using a redox initiator that uses an organic peroxide and a reducing agent such as sodium thiosulfate.

[0051] The initiator may be one generally used in radical polymerization. For example, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate, oil-soluble azo compounds such as azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), and 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, and 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,2'-azobis{2-methyl-N-[2-(1-hydroxyethyl)]propionamide}, and 2,2'-azobis{2-methyl-N-[2-(1-hydroxybutyl)]propionamide}. Water-soluble azo compounds such as 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] and its salts, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] and its salts, 2,2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane} and its salts, 2,2'-azobis(2-methylpropynamidine) and its salts, and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]; and organic peroxides such as benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-butyl peroxy-2-ethylhexanoate, and t-butyl peroxyisobutyrate. These initiators can be used alone or in combination.

[0052] From the viewpoint of the polymerization rate of the resulting aqueous resin dispersion, the polymerization temperature is preferably 50° C. or higher. In this case, it is preferable to use a reducing agent such as sodium bisulfite, ferrous sulfate, isoascorbate, or Rongalit as an initiator in combination with a water-soluble radical polymerization catalyst.

[0053] The polymerization time is preferably 30 minutes or more. If it is less than 30 minutes, the radical polymerizable monomer will not polymerize sufficiently, and the polymerization rate will tend to be poor. Also, the polymerization time is preferably 3 hours or less. If it exceeds 3 hours, a large amount of cullet will be generated during polymerization, and production stability will tend to be poor. Furthermore, known chain transfer agents such as n-dodecyl mercaptan, t-dodecyl mercaptan, and α-methylstyrene dimer can be used as molecular weight modifiers.

[0054] After the emulsion polymerization is completed, the emulsion is cooled and, when the emulsion product is taken out, it is preferable to carry out a filtration operation to prevent foreign matter or cullet from being mixed in. As the filtration method, a known method can be used, for example, a nylon mesh, a bag filter, filter paper, a metal mesh, etc.

[0055] (Preparation of Water-Based Resin Dispersion (I)) When producing the aqueous resin dispersion composition, the olefin resin (A) is blended as an aqueous resin dispersion (I). The aqueous resin dispersion (I) containing the olefin resin (A) can be prepared, for example, by the following method. A method of dispersing an olefin resin (A) in an aqueous medium using a surfactant. A method in which the organic acid groups of the olefin resin (A) are neutralized with a basic substance and dispersed in an aqueous medium. A method of dispersing a composite resin (a31) in an aqueous medium, which is an olefinic resin such as an olefinic homopolymer (A11) or an olefinic copolymer (A21) integrated with a hydrophilic polymer by graft bonding or the like.

[0056] As the aqueous resin dispersion (I) containing the olefinic resin (A), an aqueous resin dispersion containing a composite resin (a31) is preferred because the coating film has excellent water resistance and stability.

[0057] The hydrophilic polymer used in producing the composite resin (a31) refers to a polymer that has an insoluble content of 1% by mass or less when dissolved in water at 25°C at a concentration of 10% by mass. This hydrophilic polymer may be a synthetic polymer, a semi-synthetic polymer, or a natural polymer. The number-average molecular weight (Mn) of the hydrophilic polymer is preferably 300 or more. The larger the Mn of the hydrophilic polymer, the more likely it is that the mechanical stability of the aqueous resin dispersion (I) containing the olefin resin (A) will be improved.

[0058] Examples of hydrophilic synthetic polymers that can be used include polyether resins, polyvinyl alcohol resins, polyvinylpyrrolidone resins, etc. Examples of hydrophilic natural polymers that can be used include starch, gum arabic, gum tragacanth, casein, gelatin, dextrin, etc. Examples of hydrophilic semi-synthetic polymers that can be used include carboxylated starch, cationized starch, dextrin, ethyl cellulose, carboxylated methyl cellulose, hydroxyethyl cellulose, cationized cellulose, etc.

[0059] As the hydrophilic polymer, synthetic polymers are preferred because the degree of hydrophilicity is easy to control and the properties are stable, and polyvinyl alcohol resins, polyvinylpyrrolidone resins, and polyether resins are more preferred. The hydrophilic polymer may be used alone or in combination of two or more. Among them, highly hydrophilic polyether resins are preferred. The average particle size of the aqueous dispersion can be adjusted by the type and combination of hydrophilic polymers.

[0060] The polyether resin can be produced, for example, by ring-opening polymerization of a cyclic alkylene oxide or a cyclic alkylene imine. The polyether resin may be integrated with the olefin resin without being bonded to the olefin resin, but is preferably integrated by being bonded to the olefin resin because it does not bleed out from the coating film.

[0061] The polyether resin can be integrated in a bonded state with the olefin resin, for example, by the following method. A method of ring-opening polymerization of a cyclic alkylene oxide in the presence of an olefin resin having a reactive group, such as polymer (A11) or polymer (A21). A method in which a reactive group of a polyether polyol or polyether amine obtained by ring-opening polymerization or the like is reacted with a reactive group of an olefin resin having a reactive group.

[0062] Polyether polyol is a compound having a hydroxyl group, which is a reactive group, at both ends of a resin having a polyether skeleton. Polyether amine is a compound having a primary amino group, which is a reactive group, at one or both ends of a resin having a polyether skeleton. Polyether amine is preferred as a polyether resin to be integrated with an olefin-based resin. Examples of polyether amine include Huntsman's "Jeffamine" M series, D series, ED series, and "Surfonamin" L series.

[0063] The polyether resin preferably has a hydrophilic structural unit such as polyethylene oxide or polyethyleneimine, and a hydrophobic structural unit such as polypropylene oxide or polypropyleneimine. The polyether resin more preferably has a structural unit derived from polyethylene oxide and a structural unit derived from polypropylene oxide. The HLB (Hydrophile Lipophile Balance) of the polyether resin can be adjusted by the amount of the hydrophilic structural unit and the hydrophobic structural unit. The polyether resin preferably includes one with a high hydrophilicity having an HLB in the range of 9 to 18.

[0064] It is preferable to use a polyether resin having high hydrophilicity as described above in combination with a polyether resin having low hydrophilicity with an HLB value of 1 to 8. The lower the HLB value of the polyether resin, the lower the surface energy of the olefin resin integrated with the polyether resin. Therefore, when producing the composite resin (a32), the impregnation of the radical polymerizable monomer tends to be improved. The HLB value of the low hydrophilic polyether resin is preferably 1 to 6, more preferably 1 to 4.

[0065] The polyether resin preferably has one or more reactive groups capable of reacting with the olefin polymer before bonding with the olefin polymer. Examples of such reactive groups include carboxylic acid groups, dicarboxylic anhydride groups, dicarboxylic anhydride monoester groups, hydroxyl groups, amino groups, epoxy groups, and isocyanate groups. Among these, polyether resins having at least an amino group are preferred. Since amino groups are highly reactive with various reactive groups such as carboxylic acid groups, carboxylic anhydride groups, glycidyl groups, and isocyanate groups, bonding of the olefin polymer and the polyether resin is easy. The amino group may be primary, secondary, or tertiary, but primary amino groups are preferred.

[0066] The number of reactive groups per molecule of the polyether resin is one or more, preferably one. If there are two or more reactive groups, there is a possibility that a three-dimensional network structure will be formed and gelation will occur when the polyether resin is bonded to an olefin-based polymer. However, even if there are two or more reactive groups, as long as only one reactive group is more reactive than the others, there may be two or more reactive groups. Examples of such polyether resins include polyether resins having a hydroxyl group and one amino group that is more reactive than the hydroxyl group. Here, reactivity refers to reactivity with the reactive groups of the olefin-based polymer.

[0067] The weight average molecular weight (Mw) of the polyether resin is preferably 200 to 200,000, more preferably 300 to 100,000, even more preferably 500 to 10,000, and particularly preferably 500 to 3,000. The higher the Mw of the polyether resin, the lower the surface energy of the composite resin (a31) and the better the wettability tends to be. The lower the Mw of the polyether resin, the lower the viscosity of the aqueous dispersion of the composite resin (a31), which tends to make preparation easier. The Mw of the polyether resin is a value measured by GPC and converted using a polystyrene calibration curve. GPC measurement can be performed by a known method using a commercially available device and a solvent such as THF.

[0068] The composite resin (a31) is preferably an olefin resin having a reactive group, such as polymer (A11) or polymer (A21), and a polyether resin bonded together in a mass ratio of olefin resin having a reactive group:polyether resin of 100:1 to 100:100. This mass ratio is more preferably 100:5 to 100:70, and even more preferably 100:10 to 100:50. In the region where the proportion of polyether resin is low, the particle size of the composite resin (a31) tends to become smaller as the proportion increases. Therefore, when a composite resin (a32) containing the composite resin (a31) and a polymer containing a radically polymerizable monomer having a reactive group as a structural unit is produced, the polymerization of the radically polymerizable monomer tends to be improved. In the region where the proportion of polyether resin is high, the smaller the proportion, the higher the acid value of the composite resin (a31), the more likely it is that the polymerization of the radically polymerizable monomer used to produce the composite resin (a32) will be improved, and the adhesion of the coating film to the polyolefin substrate will also be improved.

[0069] An example of a method for dispersing the olefin resin (A) in an aqueous medium to obtain the aqueous resin dispersion (I) is to add a solvent other than water to the olefin resin (A), heat it appropriately to dissolve it, and then add water. This method has the advantage of easily producing an aqueous dispersion with small particle sizes. The temperature for dissolving the resin in the solvent and adding water is preferably 30 to 150°C, more preferably 50 to 100°C. The solvent other than water may be distilled off after adding water.

[0070] The aqueous resin dispersion (I) may further contain additives in addition to the olefin resin (A). Examples of additives include various pigments, resin beads, antifoaming agents, pigment dispersants, leveling agents, anti-sagging agents, curing catalysts, matting agents, UV absorbers, light stabilizers, antioxidants, heat resistance improvers, slip agents, preservatives, plasticizers, thickeners, wetting agents, and solvents. One type of additive may be used alone, or two or more types may be used in combination.

[0071] The aqueous resin dispersion (I) may further contain other polymer particles, a water-soluble resin, a viscosity control agent, an amino resin, a polyisocyanate compound, a blocked polyisocyanate compound, a melamine resin, a urea resin, a carboxy group-containing compound, a carboxy group-containing resin, an epoxy group-containing resin, an epoxy group-containing compound, or a curing agent such as a carbodiimide group-containing compound. Examples of other polymer particles include dispersed particles made of other polymers such as polyester resins, polyurethane resins, acrylic resins, acrylic silicone resins, silicone resins, fluorine resins, epoxy resins, polyolefin resins, and alkyd resins.

[0072] The aqueous resin dispersion (I) may further contain a solvent. Solvents commonly used in aqueous paints can be used. The water content in the aqueous medium is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The upper limit may be 100% by mass, 98% by mass, or 95% by mass.

[0073] Examples of the solvent include water, linear, branched, or cyclic aliphatic alcohols having 5 to 14 carbon atoms; alcohols containing an aromatic group; and alcohols of the general formula HO-(CHCHXO) p -R 1 (R 1 is a linear or branched alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a methyl group, and p is an integer of 5 or less; monoethers such as (poly)ethylene glycol or (poly)propylene glycol represented by the general formula R 2 COO-(CHCHXO) q -R 3 (R 2 , R 3is a linear or branched alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a methyl group, and q is an integer of 5 or less. Examples of suitable organic solvents include (poly)ethylene glycol ether esters or (poly)propylene glycol ether esters represented by the following formula:

[0074] Of these, linear, branched, or cyclic aliphatic alcohols having 5 to 14 carbon atoms are preferred, alcohol solvents having 7 to 14 carbon atoms are more preferred, and at least one alcohol solvent selected from the group consisting of 1-octanol, 2-octanol, 2-ethyl-1-hexanol, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol mono-n-butyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-methyl ether, and dipropylene glycol mono-n-butyl ether is particularly preferred.

[0075] The aqueous resin dispersion (I) may further contain a surfactant to improve storage stability. Examples of the surfactant include various anionic, cationic, or nonionic surfactants, and polymeric surfactants. So-called reactive surfactants having an ethylenically unsaturated bond can also be used as the surfactant. Among these, anionic surfactants are preferred in terms of improving the storage stability of the resulting aqueous dispersion. The anionic surfactant is not particularly limited, but examples include ADEKA REASOAP SR, a reactive surfactant, and Neocoal SW-C, a non-reactive surfactant, manufactured by ADEKA Corporation.

[0076] The proportion of the surfactant is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and may be 0 part by mass, relative to 100 parts by mass of the olefin resin (A). By keeping the proportion at 2 parts by mass or less, stability can be maintained during formulation into a coating material without impairing water resistance.

[0077] The amount of solvent other than water contained in the aqueous resin dispersion (I) of olefin resin (A) is preferably 50% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 1% by mass or less. The solvent other than water can be any of the aforementioned solvents, but solvents that dissolve in water at 1% by mass or more are preferred, and solvents that dissolve at 5% by mass or more are more preferred. Preferred solvents include, for example, methyl ethyl ketone, cyclohexanone, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, cyclohexanol, tetrahydrofuran, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-methoxypropanol, and 2-ethoxypropanol.

[0078] The apparatus for producing the aqueous dispersion by adding water after dissolving in the solvent is not particularly limited. For example, a reaction vessel equipped with a stirrer, a single-screw or twin-screw kneader, etc. can be used. The stirring speed varies slightly depending on the type of apparatus, but is usually in the range of 10 to 1000 rpm. When the stirring speed is equal to or higher than the lower limit of the above range, the particle size of the aqueous resin dispersion (I) containing the olefin resin (A) is unlikely to become excessively large.

[0079] The average particle size of the aqueous dispersion (I) containing the olefin resin (A) is preferably 500 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. The smaller the average particle size of the aqueous dispersion (I), the better the film-forming properties and adhesion of the coating film tend to be. The lower limit of the average particle size of the olefin resin (A) is not particularly limited, but may be, for example, about 1 nm. The average particle size of the olefin resin (A) is a cumulant average particle size measured using a concentrated particle size analyzer "FPAR-1000" manufactured by Otsuka Electronics Co., Ltd.

[0080] (Water-based resin dispersion (II)) The aqueous resin dispersion (II) contains the olefin resin (B) in a dispersed state. The content of the olefin resin (B) in the aqueous resin dispersion (II) is preferably 5 to 80 mass %, more preferably 10 to 60 mass %, and even more preferably 20 to 50 mass %.

[0081] In the aqueous resin dispersion composition, the olefin resin (B) is a resin different from the olefin resin (A). Examples of olefins include ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, cyclopentene, cyclohexene, and norbornene. One type of olefin may be used alone, or two or more types may be used in combination.

[0082] The proportion of the olefin-derived structural units is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more of the total number of moles of structural units constituting the olefin-based resin (B). The higher the proportion of the olefin-derived structural units, the more likely it is that the adhesion to polyolefin substrates will improve.

[0083] The olefin resin (B) may be linear or branched. From the viewpoint of adhesion to polyolefin substrates, the olefin resin (B) preferably contains a propylene polymer having structural units derived from propylene, and more preferably contains an ethylene-propylene copolymer, an ethylene-propylene-butene copolymer, or a propylene-butene copolymer. The proportion of structural units derived from propylene in the propylene polymer is preferably 50 mol % or more, more preferably 60 mol % or more, and even more preferably 70 mol % or more of all structural units derived from olefin in the olefin resin (B).

[0084] The olefin resin (B) may be a chlorinated polyolefin obtained by chlorinating an olefin resin. In this case, the chlorination degree of the chlorinated polyolefin is preferably 40% by mass or less, more preferably 30% by mass or less.

[0085] Examples of the olefin-based resin (B) include an olefin homopolymer (hereinafter referred to as "olefin-based homopolymer (B1)"), a copolymer of an olefin with another monomer copolymerizable with the olefin (hereinafter referred to as "olefin-based copolymer (B2)"), and an olefin-based composite resin (B3).

[0086] The olefin homopolymer (B1), the olefin copolymer (B2), and the olefin composite resin (B3) may have a group reactive with an amino group, such as a carboxy group, an epoxy group, an isocyanato group, a sulfonic acid group, or a hydroxyl group. The reactive group may be an acid anhydride structure of a carboxy group.

[0087] As the olefin resin (B), an olefin resin (B) having a reactive group is more preferred in terms of excellent compatibility with the olefin resin (A) and excellent water-resistant adhesion. Hereinafter, the olefin homopolymer (B1) having a reactive group will be referred to as "polymer (B11)", the olefin copolymer (B2) having a reactive group will be referred to as "polymer (B21)", and the olefin composite resin (B3) having a reactive group will be referred to as "polymer (B31)".

[0088] Examples of the olefin copolymer (B2) include a copolymer of ethylene and propylene; a copolymer of at least one of ethylene and propylene with a monomer copolymerizable with ethylene and propylene (for example, an α-olefin having 4 or more carbon atoms, such as butene-1, pentene-1, hexene-1, heptene-1, octene-1, cyclopentene, cyclohexene, or norbornene); a copolymer of two or more α-olefins selected from the group consisting of the α-olefins having 4 or more carbon atoms; Copolymers of α-olefins having two or more carbon atoms and non-aromatic monomers other than α-olefins, such as vinyl acetate, acrylic esters, and methacrylic esters; Copolymers of α-olefins having two or more carbon atoms and aromatic monomers such as aromatic vinyl monomers, or hydrogenated copolymers thereof; Conjugated diene block copolymers or hydrogenated products thereof are exemplified. Two or more types of comonomers other than olefins may be used.

[0089] Examples of the olefin composite resin (B3) include composite resin (b31) in which at least one resin selected from the group consisting of olefin homopolymer (B1) and olefin copolymer (B2) is integrated with a resin having a structure different from that of the above resin, and composite resin (b32) in which the above composite resin (b31) is further integrated with a resin having a structure different from that of the above composite resin (b31). It is preferable that a plurality of resins having different structures are integrated to form a graft polymer, a core-shell structure, a microphase-separated structure, an interpenetrating polymer network structure, or the like.

[0090] The Tm of the olefin resin (B) is preferably 100° C. or lower, more preferably 90° C. or lower, and even more preferably 80° C. or lower. The Tm of the olefin resin (B) is preferably 20° C. or higher, and more preferably 40° C. or higher. The higher the Tm, the less sticky the resin will be, and the lower the Tm, the lower the drying and baking temperatures will tend to be. The Tm of the olefin resin (B) can be measured using a differential scanning calorimeter DSCEXSTAR6000 manufactured by Hitachi High-Tech Science Corporation.

[0091] The Mw of the olefin resin (B) is measured by GPC. The GPC measurement is performed after preparing an aqueous dispersion and vacuum drying it at 40°C for 12 hours. The measurement is performed by a conventional method using a commercially available device and a solvent such as orthodichlorobenzene or THF.

[0092] The Mw of the olefin resin (B) is preferably more than 10,000 and not more than 200,000. The lower limit of the Mw of the olefin resin (B) is more preferably more than 20,000, and even more preferably more than 30,000. The upper limit of the Mw of the olefin resin (B) is preferably not more than 100,000. The higher the Mw of the olefin resin (B), the greater the durability of the coating film tends to be. Furthermore, the lower the Mw of the olefin resin (B), the better the film-forming properties of the coating film and the greater the adhesion to the substrate.

[0093] The complex viscosity of the olefin resin (B) at 180°C and 0.1 Hz is 1,500 Pa·s or less. The complex viscosity of the olefin resin (B) at 180°C and 0.1 Hz is preferably 1,500 Pa·s or less, and more preferably 1,000 Pa·s or less. The lower limit of the complex viscosity of the olefin resin (B) at 180°C and 0.1 Hz may be, for example, 0.1 Pa·s. It is preferably 10 Pa·s or more, and more preferably 50 Pa·s or more. The complex viscosity is measured using a rheometer at 180°C and 0.1 Hz after the aqueous dispersion containing the olefin resin (B) is vacuum dried at 40°C for 12 hours.

[0094] The MFR of the olefin resin (B) is preferably 20 g / 10 min or more, more preferably 100 g / 10 min or more, and even more preferably 500 g / 10 min or more at 230° C. and a load of 2.16 kg. The upper limit of the MFR of the olefin resin (B) may be, for example, 10,000 g / 10 min. The MFR of the olefin resin (B) is measured by the method of ASTM D1238.

[0095] The olefin resin (B) can be produced, for example, by polymerizing an olefin by a method such as radical polymerization, cationic polymerization, anionic polymerization, or coordination polymerization. These polymerizations may each be living polymerizations. The details and preferred embodiments of the polymerization method for the olefin resin (B) are the same as those already explained for the olefin resin (A).

[0096] The olefin resin (B) is preferably an olefin composite resin (B3). The olefin composite resin (B3) is preferably a composite resin (b31) in which at least one resin selected from the group consisting of an olefin homopolymer (B1) and an olefin copolymer (B2) is integrated with a hydrophilic polymer such as a polyether resin, or a composite resin (b32) in which a polymer having a structural unit derived from a radically polymerizable monomer having a reactive group is integrated with the composite resin (b31). The details and preferred embodiments of the production methods for these are the same as those already explained for the olefin resin (A).

[0097] (Preparation of Water-Based Resin Dispersion (II)) When producing the aqueous resin dispersion composition, the olefin resin (B) is blended as the aqueous resin dispersion (II). The method for preparing the aqueous resin dispersion (II) containing the olefin resin (B) is the same as that already described for the aqueous resin dispersion (I).

[0098] The aqueous resin dispersion (II) may further contain additives in addition to the olefin resin (B). Examples of additives include various pigments, resin beads, antifoaming agents, pigment dispersants, leveling agents, anti-sagging agents, curing catalysts, matting agents, UV absorbers, light stabilizers, antioxidants, heat resistance improvers, slip agents, preservatives, plasticizers, thickeners, wetting agents, and solvents. One type of additive may be used alone, or two or more types may be used in combination.

[0099] The aqueous resin dispersion (II) may further contain other polymer particles, a water-soluble resin, a viscosity control agent, an amino resin, a polyisocyanate compound, a blocked polyisocyanate compound, a melamine resin, a urea resin, a carboxy group-containing compound, a carboxy group-containing resin, an epoxy group-containing resin, an epoxy group-containing compound, or a curing agent such as a carbodiimide group-containing compound. Examples of other polymer particles include dispersed particles made of other polymers such as polyester resins, polyurethane resins, acrylic resins, acrylic silicone resins, silicone resins, fluorine resins, epoxy resins, polyolefin resins, and alkyd resins.

[0100] The aqueous resin dispersion (II) may further contain a solvent. As the solvent, those commonly used in aqueous paints can be used. The content of water in the aqueous medium is preferably 20 to 95% by mass, more preferably 40 to 90% by mass, and even more preferably 50 to 80% by mass.

[0101] Examples of the solvent include water, linear, branched, or cyclic aliphatic alcohols having 5 to 14 carbon atoms; alcohols containing an aromatic group; and alcohols of the general formula HO-(CHCHXO) p -R 1 (R 1 is a linear or branched alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a methyl group, and p is an integer of 5 or less; monoethers such as (poly)ethylene glycol or (poly)propylene glycol represented by the general formula R 2 COO-(CHCHXO) q -R 3 (R 2 , R 3 is a linear or branched alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a methyl group, and q is an integer of 5 or less. Examples of suitable organic solvents include (poly)ethylene glycol ether esters or (poly)propylene glycol ether esters represented by the following formula:

[0102] Of these, linear, branched, or cyclic aliphatic alcohols having 5 to 14 carbon atoms are preferred, alcohol solvents having 7 to 14 carbon atoms are more preferred, and at least one alcohol solvent selected from the group consisting of 1-octanol, 2-octanol, 2-ethyl-1-hexanol, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol mono-n-butyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-methyl ether, and dipropylene glycol mono-n-butyl ether is particularly preferred.

[0103] The aqueous resin dispersion (II) may further contain a surfactant to improve storage stability. Examples of the surfactant include various anionic, cationic, or nonionic surfactants, and polymeric surfactants. Surfactants that have an ethylenically unsaturated bond, so-called reactive surfactants, can also be used. Among these, anionic surfactants are preferred in terms of improving the storage stability of the resulting aqueous dispersion. The anionic surfactant is not particularly limited, but examples include ADEKA REASOAP SR, a reactive surfactant, and Neocoal SW-C, a non-reactive surfactant, manufactured by ADEKA Corporation.

[0104] The proportion of the surfactant is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and may be 0 part by mass, relative to 100 parts by mass of the olefin resin (B). By keeping the proportion at 2 parts by mass or less, stability can be maintained during formulation into a coating material without impairing water resistance.

[0105] The amount of the solvent other than water contained in the aqueous resin dispersion (II) of the olefin resin (B) is preferably 50% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 1% by mass or less. The solvent other than water can be any of the above-mentioned solvents, but among them, a solvent that dissolves in water at 1% by mass or more is preferred, and a solvent that dissolves in water at 5% by mass or more is more preferred. Examples of preferred solvents include methyl ethyl ketone, cyclohexanone, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, cyclohexanol, tetrahydrofuran, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-methoxypropanol, and 2-ethoxypropanol.

[0106] The apparatus for producing the aqueous dispersion by adding water after dissolving in the solvent is not particularly limited. For example, a reaction vessel equipped with a stirrer, a single-screw or twin-screw kneader, etc. can be used. The stirring speed varies slightly depending on the type of apparatus, but is usually in the range of 10 to 1000 rpm. When the stirring speed is equal to or higher than the lower limit of the above range, the particle size of the aqueous dispersion (II) is unlikely to become excessively large.

[0107] The average particle size of the aqueous dispersion (II) containing the olefin resin (B) is preferably 500 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. The smaller the average particle size of the olefin resin (B), the more improved the film-forming property tends to be. The lower limit of the average particle size of the olefin resin (B) is not particularly limited, but may be, for example, about 1 nm. The average particle size of the olefin resin (B) is a cumulant average particle size measured using a concentrated particle size analyzer "FPAR-1000" manufactured by Otsuka Electronics Co., Ltd.

[0108] (Method for producing aqueous resin dispersion composition) In the aqueous resin dispersion composition, an aqueous resin dispersion (I) containing an olefin resin (A) and an aqueous resin dispersion (II) containing an olefin resin (B) are present in a dispersed state. The method for producing the aqueous resin dispersion composition is not particularly limited.

[0109] A preferred method for producing the aqueous resin dispersion composition includes, for example, preparing an aqueous resin dispersion (I) of an olefin resin (A), preparing an aqueous resin dispersion (II) containing a hydroxyl group-containing resin (B), and mixing the aqueous resin dispersion (I) and the aqueous resin dispersion (II).

[0110] The mass ratio of the olefin resin (A) to the olefin resin (B) (hereinafter referred to as "(A) / (B) ratio") is preferably 50 / 50 to 85 / 15, more preferably 55 / 45 to 83 / 17, and even more preferably 60 / 40 to 80 / 20. When the (A) / (B) ratio is equal to or less than the upper limit of the above-mentioned range, the coating strength is improved and peel strength tends to be good. When the (A) / (B) ratio is equal to or greater than the lower limit of the above-mentioned range, film formability is improved and adhesion tends to be good. The (A) / (B) ratio is the mass ratio of the solid content.

[0111] (additives) The aqueous resin dispersion composition preferably further contains additives in addition to the aqueous resin dispersion (I) and the aqueous resin dispersion (II). Examples of additives include various pigments, resin beads, antifoaming agents, pigment dispersants, leveling agents, anti-sagging agents, curing catalysts, matting agents, UV absorbers, light stabilizers, antioxidants, heat resistance improvers, slip agents, preservatives, plasticizers, thickeners, wetting agents, and solvents. One type of additive may be used alone, or two or more types may be used in combination.

[0112] The aqueous resin dispersion composition may further contain other polymer particles, a water-soluble resin, a viscosity control agent, an amino resin, a polyisocyanate compound, a blocked polyisocyanate compound, a melamine resin, a urea resin, a carboxy group-containing compound, a carboxy group-containing resin, an epoxy group-containing resin, an epoxy group-containing compound, or a curing agent such as a carbodiimide group-containing compound. Examples of other polymer particles include dispersed particles made of other polymers such as polyester resins, polyurethane resins, acrylic resins, acrylic silicone resins, silicone resins, fluorine resins, epoxy resins, polyolefin resins, and alkyd resins.

[0113] Examples of pigments include color pigments, extender pigments, and luster pigments. Examples of color pigments include titanium oxide, zinc oxide, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, threne pigments, and perylene pigments. Examples of extender pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica, and alumina white. Examples of luster pigments include aluminum, copper, zinc, brass, nickel, aluminum oxide, mica, aluminum oxide coated with titanium oxide or iron oxide, mica coated with titanium oxide or iron oxide, glass flakes, and hologram pigments. The pigments may be used alone or in combination of two or more.

[0114] (solvent) The aqueous resin dispersion composition may further contain a solvent. Solvents commonly used in aqueous paints can be used. Examples of such solvents include water, linear, branched, or cyclic aliphatic alcohols having 5 to 14 carbon atoms; alcohols containing an aromatic group; and alcohols of the general formula HO-(CHCHXO). p -R 1 (R 1is a linear or branched alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a methyl group, and p is an integer of 5 or less; monoethers such as (poly)ethylene glycol or (poly)propylene glycol represented by the general formula R 2 COO-(CHCHXO) q -R 3 (R 2 , R 3 is a linear or branched alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a methyl group, and q is an integer of 5 or less. Examples of suitable organic solvents include (poly)ethylene glycol ether esters or (poly)propylene glycol ether esters represented by the following formula:

[0115] Of these, linear, branched, or cyclic aliphatic alcohols having 5 to 14 carbon atoms are preferred, alcohol solvents having 7 to 14 carbon atoms are more preferred, and at least one alcohol solvent selected from the group consisting of 1-octanol, 2-octanol, 2-ethyl-1-hexanol, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol mono-n-butyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-methyl ether, and dipropylene glycol mono-n-butyl ether is even more preferred.

[0116] [Aqueous resin dispersion composition] The aqueous coating composition of the present invention is an aqueous resin dispersion composition containing an aqueous resin dispersion (I) containing an olefinic resin (A) and an aqueous resin dispersion (II) containing an olefinic resin (B) in a dispersed state, and may be produced by any method.

[0117] A method for producing the aqueous coating composition of the present invention preferably includes, for example, preparing an aqueous resin dispersion (I) of an olefin resin (A), preparing an aqueous resin dispersion (II) containing a hydroxyl group-containing resin (B), and mixing the aqueous resin dispersion (I) with the aqueous resin dispersion (II).

[0118] The mass ratio of the olefin resin (A) to the olefin resin (B) (hereinafter also referred to as "(A) / (B) ratio") is preferably (A) / (B) = 50 / 50 to 95 / 5 (solid content mass), more preferably (A) / (B) = 55 / 45 to 90 / 10, and particularly preferably (A) / (B) = 60 / 40 to 85 / 15. When the (A) / (B) ratio is equal to or less than the upper limit, film-forming properties tend to be improved and adhesion tends to be good. When the (A) / (B) ratio is equal to or greater than the above lower limit, the coating strength is improved and peel strength tends to be good.

[0119] The aqueous resin dispersion composition of the present invention preferably further contains various additives, such as various pigments, resin beads, antifoaming agents, pigment dispersants, leveling agents, anti-sagging agents, curing catalysts, matting agents, UV absorbers, light stabilizers, antioxidants, heat resistance improvers, slip agents, preservatives, plasticizers, thickeners, wetting agents, and solvents, and one or more of these may be used. The aqueous resin dispersion composition may also be mixed with other polymer particles (for example, dispersed particles made of other polymers such as polyester resins, polyurethane resins, acrylic resins, acrylic silicone resins, silicone resins, fluorine resins, epoxy resins, polyolefin resins, and alkyd resins), water-soluble resins, viscosity control agents, and curing agents such as amino resins, polyisocyanate compounds, blocked polyisocyanate compounds, melamine resins, urea resins, carboxy group-containing compounds, carboxy group-containing resins, epoxy group-containing resins, epoxy group-containing compounds, and carbodiimide group-containing compounds.

[0120] Examples of pigments include color pigments, extender pigments, and luster pigments. Examples of color pigments include titanium oxide, zinc oxide, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, threne pigments, and perylene pigments. Examples of extender pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica, and alumina white. Examples of luster pigments include aluminum, copper, zinc, brass, nickel, aluminum oxide, mica, aluminum oxide coated with titanium oxide or iron oxide, mica coated with titanium oxide or iron oxide, glass flakes, hologram pigments, etc. These may be used alone or in combination.

[0121] The aqueous resin dispersion composition of the present invention may further contain a solvent. Solvents commonly used in aqueous paints can be used. Examples of such solvents include water, linear, branched, or cyclic aliphatic alcohols having 5 to 14 carbon atoms; alcohols containing an aromatic group; and alcohols of the general formula HO-(CHCHXO). p -R 4 (R 4 is a linear or branched alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a methyl group, and p is an integer of 5 or less; monoethers such as (poly)ethylene glycol or (poly)propylene glycol represented by the general formula R 5 COO-(CHCHXO) q -R 6 (R 5 , R 6is a linear or branched alkyl group having 1 to 10 carbon atoms, X is a hydrogen atom or a methyl group, and q is an integer of 5 or less. Examples of suitable organic solvents include (poly)ethylene glycol ether esters or (poly)propylene glycol ether esters represented by the following formula:

[0122] Of these, linear, branched, or cyclic aliphatic alcohols having 5 to 14 carbon atoms are preferred, alcohol solvents having 7 to 14 carbon atoms are more preferred, and at least one alcohol solvent selected from the group consisting of 1-octanol, 2-octanol, 2-ethyl-1-hexanol, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol mono-n-butyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-methyl ether, and dipropylene glycol mono-n-butyl ether is particularly preferred.

[0123] [Application] The aqueous resin dispersion composition can be used for primers, paints, adhesives, ink binders, etc. The aqueous resin dispersion composition is particularly useful for paints, inks, and adhesives. Applications of the aqueous resin dispersion composition include, for example, automotive paints for automobile interiors, automotive paints for automobile exteriors, paints for home appliances such as mobile phones and personal computers, paints for building materials, and heat sealants. Use as a primer for polyolefin substrates is particularly preferred. [Example]

[0124] The embodiments will be described in more detail below with reference to examples and comparative examples. In the examples, "parts" means "parts by mass."

[0125] [Measurement and Evaluation] Detailed methods for measurement and evaluation in the examples are as follows.

[0126] (Average particle size of olefin resin) The cumulant average particle size of the olefin resin dispersion was determined using a concentrated particle size analyzer "FPAR-1000" (manufactured by Otsuka Electronics Co., Ltd.).

[0127] (Weight average molecular weight of olefin resin) The olefin resin dispersion was vacuum dried at 40°C for 12 hours and then measured using a GPC system (Tosoh Corporation, HLC-8320). A 0.4% by mass solution of the olefin resin in THF was prepared, and 100 μL of the solution was injected into the system equipped with a Tosoh Corporation column (TSKgel G5000HXL, GMHXL-L, TSKguardcolumnHXL-H). Measurement was performed under conditions of a flow rate of 1 mL / min, eluent: THF (stabilized with BHT and 1 mM citric acid), and column temperature: 40°C, and the weight-average molecular weight (Mw) was calculated in terms of standard polystyrene.

[0128] (Complex viscosity of olefin resin) The olefin resin dispersion was vacuum dried at 40°C for 12 hours, and then the complex viscosity was measured at 200°C, 0.1 Hz, or 180°C, 0.1 Hz using a HAAKE MARS60 (manufactured by Thermo Fisher Scientific) with a cone plate having a diameter of 35 mm and a cone angle of 1°.

[0129] (Calculation of the composition ratio of each olefin component in the olefin resin dispersion) The olefin resin dispersion was vacuum dried at 40°C for 12 hours, then dissolved in dichlorobenzene at 100°C to a concentration of 2% by weight. The dispersion was then analyzed using a JEOL RESONANCE NMR (JNM-ECS400) at 400 MHz, 13C, pulse width 3.47 μs, pulse repetition time 3.04 s, temperature 100°C, and 4096 scans. The results were assigned according to the method described in "Study of Propylene-1-butene-ethylene Terpolymer and Reactor Blend by TREF and 13C-NMR" (authors: Adilson Arli Silva Filho and Griselda Barrera Galland, Journal of Applied Polymer Science), in the Polymer Analysis Handbook (4th edition, edited by the Polymer Analysis Research Forum of the Japan Society for Analytical Chemistry). The proportions of each olefin component in the olefin resin dispersion were calculated from the peak area ratios of each olefin component.

[0130] (Adhesive) Adhesion to polyolefin substrates was evaluated by peel strength. A 1 cm thick piece of masking tape was attached to one edge of a 3 mm thick, 150 mm long, and 100 mm wide polypropylene substrate to prevent the aqueous resin dispersion composition from being applied. The substrate surface was then wiped clean with isopropyl alcohol. The aqueous resin dispersion composition was then spray-coated to a dry film thickness of 10 μm. The test piece was then dried in a Safebend dryer at 80°C for 5 minutes, after which the masking tape was removed.

[0131] Next, the resulting test specimens were spray-coated with a two-component polyurethane coating to a dry thickness of 100 μm. The coated specimens were then dried in a Safebend dryer at 120°C for 30 minutes. The coated specimens were then left at 25°C for at least 24 hours to cure the two-component polyurethane coating. Kraft tape was then applied over the cured two-component polyurethane coating, and a 1.5 cm wide cut was made in the tape and coating perpendicular to the edge where the masking tape was removed using a cutter. The two-component polyurethane coating and the Kraft tape in the area where the masking tape was removed were then peeled off from the substrate and peeled at a 180° angle to a length that extended beyond the edge of the substrate opposite the area where the masking tape was removed. The edge of the coating that had been peeled from the substrate was attached to a rheometer, and the peel strength in the 180° direction was measured at a pulling rate of 50 mm / min. The peel strength was calculated by measuring the average peel strength when the film was pulled 50 mm over a width of 1.5 cm and converting it into the peel strength per 1 cm width.

[0132] [Production Example 1: Preparation of Water-Based Resin Dispersion (I)] First, a maleic anhydride-modified propylene-butene copolymer (A21) was prepared as follows. A 2 L glass flask equipped with a bottom-drawing valve and an oil-circulating jacket heater was equipped with a nitrogen gas inlet tube, a reflux condenser, a thermometer, and a stirrer. Then, 100 g of "Tafmer XM-5070" (Mitsui Chemicals, Inc., melting point 70°C, propylene content 70 mol%, weight-average molecular weight [Mw] 250,000), a propylene-butene copolymer (A2) polymerized with a metallocene catalyst, and 150 g of toluene were added. The atmosphere inside the vessel was then purged with nitrogen gas, and the temperature was raised to 110°C. After the temperature was raised, 3.8 g of maleic anhydride and 1.5 g of t-butylperoxyisopropyl monocarbonate (NOF Corp., "Perbutyl I") were added, and the reaction was continued with stirring at the same temperature for 7 hours. Then, 0.5 g of the solution was withdrawn, acetone was added, and the precipitated polymer was filtered. Further precipitation with acetone and filtration were repeated, and the final polymer was dried under reduced pressure. The maleic anhydride group content (graft ratio) of the resulting maleic anhydride-modified propylene-butene copolymer (A21) was 1.0 mass % (0.1 mmol / g as maleic anhydride groups).

[0133] After the reaction was completed, the system was cooled to around 70°C, and 107 g of toluene was added. Next, 700 g of 70°C hot water was added and stirred for 30 minutes. After standing, the mixture separated into two phases, and the lower phase (aqueous phase) was removed from the bottom of the flask. 20 g of polyetheramine (trade name "Jeffamine M-2005", number average molecular weight 2000) dissolved in 230 g of 2-propanol was added dropwise to the flask over 1 hour at 70°C, and the mixture was further reacted at 70°C for 1 hour. 10 g of polyetheramine (trade name "Jeffamine M-1000", number average molecular weight 1000) dissolved in 220 g of 2-propanol was then added dropwise over 1 hour at 70°C, and the mixture was further reacted at 70°C for 1 hour.

[0134] Then, 2 g of dimethylethanolamine, 2 g of 2-propanol, and 60 g of water were added to neutralize the system. The temperature of the resulting reaction solution was kept at 50°C, and while heating and stirring, 420 g of water was added dropwise. The reduced pressure in the system was reduced, and toluene and 2-propanol were distilled off under reduced pressure until the polymer concentration reached 30% by mass, yielding a milky white aqueous resin dispersion (I) in which an olefin composite resin (A3-1) with an average particle size of 110 nm was dispersed.

[0135] [Production Example 2: Preparation of Water-Based Resin Dispersion (I)] An aqueous resin dispersion (I) was obtained in the same manner as in Production Example 1, except that the amount of Tafmer XM-5070 and the amount of Elmodu S400 (a propylene polymer manufactured by Idemitsu Kosan Co., Ltd., having a melting point of 80°C and a weight-average molecular weight of 45,000) were changed to 80 g and 20 g, respectively. The maleic anhydride group content (graft ratio) of the obtained maleic anhydride-modified propylene-butene copolymer (A21) was 1.0 mass% (0.1 mmol / g as maleic anhydride groups), and the average particle size of the aqueous resin dispersion (I) in which the olefin composite resin (A3-2) was dispersed was 120 nm.

[0136] [Production Example 3: Preparation of olefin resin (B21) having reactive groups] 200 kg of "Tafmer XM-5070" (manufactured by Mitsui Chemicals, Inc., melting point 70°C, propylene content 70 mol%, weight average molecular weight [Mw] 250,000), a propylene-butene copolymer (B2) polymerized using a metallocene catalyst, and 5 kg of maleic anhydride were dry-blended in a super mixer. The mixture was then kneaded in a twin-screw extruder (manufactured by The Japan Steel Works, Ltd., "TEX54αII") under conditions of a cylinder temperature of 200°C, a screw rotation speed of 125 rpm, and a discharge rate of 80 kg / hour, while feeding t-butylperoxyisopropyl monocarbonate (manufactured by NOF Corporation, "Perbutyl I") with a liquid addition pump in an amount of 1 part by mass per 100 parts by mass of the propylene-butene copolymer (A2). A pellet-shaped maleic anhydride-modified propylene-butene copolymer (B21) was obtained. The maleic anhydride-modified propylene-butene copolymer (B21) thus obtained had a maleic anhydride group content (graft ratio) of 1.0 mass% (0.1 mmol / g as maleic anhydride groups, 0.2 mmol / g as carboxylic acid groups), a weight-average molecular weight (polystyrene equivalent) [Mw] of 156,000, and a number-average molecular weight [Mn] of 84,000.

[0137] [Production Example 4: Preparation of aqueous resin dispersion (II)] An olefin-based composite resin (B31) having a reactive group was prepared as follows. A 2L glass flask was equipped with a nitrogen gas inlet tube, reflux condenser, thermometer, and stirrer, and then 50g of maleic anhydride-modified propylene-butene copolymer (B21), 50g of Elmodu S600 (a propylene polymer with a melting point of 80°C, MFR of 350, and a molecular weight of 75,000, manufactured by Idemitsu Kosan Co., Ltd.), and 67g of toluene were added, the atmosphere inside the vessel was replaced with nitrogen gas, and the temperature was raised to 110°C. After the temperature was raised, 2.0g of maleic anhydride and 1.0g of t-butylperoxyisopropyl monocarbonate ("Perbutyl I" manufactured by NOF Corporation) were added, and the reaction was carried out with continued stirring at the same temperature for 7 hours.

[0138] After the above reaction was completed, the system was cooled to around 70°C, 53 g of toluene was added, and 15 g of polyetheramine (trade name "Jeffamine M-1000") dissolved in 180 g of 2-propanol (number average molecular weight 1000, equivalent to 15 parts by mass per 100 parts by mass of maleic anhydride-modified propylene-butene copolymer (B21)) was added dropwise at 70°C over 1 hour, followed by further reaction at 70°C for 1 hour.

[0139] Subsequently, 2 g of dimethylethanolamine and 50 g of water were added to neutralize the system. The temperature of the resulting reaction solution was maintained at 50°C, and while heating and stirring, 350 g of water was added dropwise. The vacuum level in the system was reduced, and toluene and 2-propanol were distilled off under reduced pressure until the polymer concentration reached 30% by mass, yielding a milky-white aqueous resin dispersion (II) containing an olefin composite resin (B31). The olefin component ratio, complex viscosity, and average particle size of the resulting aqueous resin dispersion (II) are shown in Table 1.

[0140] [Production Example 5: Preparation of aqueous resin dispersion (II)] An aqueous resin dispersion (II) was obtained under the same conditions as in Production Example 4, except that Elmodu S400 (a propylene polymer having a melting point of 80°C, MFR of 2000, and a molecular weight of 45000, manufactured by Idemitsu Kosan Co., Ltd.) was used instead of Elmodu S600. The olefin component ratio, complex viscosity, and average particle size of the obtained aqueous resin dispersion (II) are shown in Table 1.

[0141] [Production Example 6: Preparation of aqueous resin dispersion (II)] An aqueous resin dispersion (II) was obtained under the same conditions as in Production Example 4, except that Elmodu S600 was replaced with Licosene PP1602 (a propylene-ethylene copolymer with a melting point of 70°C and a molecular weight of 25,000, manufactured by Clariant). The olefin component ratio, complex viscosity, and average particle size of the obtained aqueous resin dispersion (II-4) are shown in Table 1.

[0142] [Production Example 7: Preparation of aqueous resin dispersion (II)] An aqueous resin dispersion (II) was obtained under the same conditions as in Production Example 4, except that 50 g of the maleic anhydride-modified propylene-butene copolymer (B22) and 50 g of Elmodu S600 were replaced with 100 g of Licosene PP1602 (a propylene-ethylene copolymer having a melting point of 70°C and a molecular weight of 25,000, manufactured by Clariant). The olefin component ratio, complex viscosity, and average particle size of the obtained aqueous resin dispersion (II) are shown in Table 1.

[0143] [Example 1] Eighty parts of the aqueous resin dispersion (I) obtained above was mixed to form the olefin resin (A) dispersion, and 20 parts of Aurouren AE-301 (an aqueous resin dispersion consisting of a propylene-ethylene copolymer, with an average particle size of 70 nm and a molecular weight of 34,000, manufactured by Nippon Paper Industries Co., Ltd.) was mixed to form the aqueous resin dispersion (II). Furthermore, 3.5 parts of TEGO WET KL-245 (manufactured by EVONIK) were added as a substrate wetting agent, and 30.75 parts of WT-9004 (manufactured by Nippon Pigment Co., Ltd.) were added as a pigment. The mixture was then stirred for 10 minutes at 500 rpm using a Homodisper stirrer, yielding the aqueous resin dispersion composition of Example 1. The measurement and evaluation results are shown in Table 1.

[0144] [Examples 2 to 5] An aqueous resin dispersion composition was obtained in the same manner as in Example 1, except that the aqueous resin dispersion (I) and the aqueous resin dispersion (II) in Example 1 were changed to those shown in Table 1. The measurement results and evaluation results are shown in Table 1.

[0145] [Comparative Example 1] An aqueous resin dispersion composition was obtained in the same manner as in Example 1, except that the aqueous resin dispersion (II-1) of Example 1 was not used. The measurement results and evaluation results are shown in Table 1.

[0146] Comparative Example 2 An aqueous resin dispersion composition was obtained in the same manner as in Example 1, except that the aqueous resin dispersion (I-1) in Example 1 was replaced with (I-2) and the aqueous resin dispersion (II-1) was not used. The measurement results and evaluation results are shown in Table 1.

[0147] [Table 1]

[0148] Examples 1 to 5, which used the aqueous resin dispersion composition of the present invention, had high peel strength and excellent adhesion. On the other hand, Comparative Example 1, which did not contain the aqueous resin dispersion (II-1), and Comparative Example 2, in which the resin was mixed and then emulsified, had low peel strength and poor adhesion. [Industrial Applicability]

[0149] According to the present invention, it is possible to provide an aqueous resin dispersion composition that can form a coating film having excellent adhesion to a polyolefin substrate and also has excellent film-forming properties.

Claims

1. an aqueous resin dispersion (I) containing an olefin resin (A) having a complex viscosity of more than 1,500 Pa s at 200°C and 0.1 Hz; an aqueous resin dispersion (II) containing an olefin resin (B) having a complex viscosity of 1,500 Pa s or less at 180°C and 0.1 Hz; An aqueous resin dispersion composition comprising:

2. 2. The aqueous resin dispersion composition according to claim 1, wherein a mass ratio of the olefin-based resin (A) to the olefin-based resin (B) is 50 / 50 to 85 / 15.

3. 3. The aqueous resin dispersion composition according to claim 1, wherein the proportion of propylene-derived structural units among the olefin-derived structural units of the olefin-based resin (A) and the olefin-based resin (B) is 50 mol % or more.

4. 3. The aqueous resin dispersion composition according to claim 1, wherein the average particle size of the aqueous resin dispersion (I) is 500 nm or less.

5. 3. The aqueous resin dispersion composition according to claim 1, wherein the average particle size of the aqueous resin dispersion (II) is 500 nm or less.

6. A coating composition comprising the aqueous resin dispersion composition according to claim 1 or 2.

7. An adhesive composition comprising the aqueous resin dispersion composition according to claim 1 or 2.

8. An ink composition comprising the aqueous resin dispersion composition according to claim 1 or 2.

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