Aqueous dispersion

Abstract

The present disclosure provides an aqueous dispersion that has good mix stability with organic solvents, excellent adhesion to polyolefin substrates, and good water resistance. Specifically, the present disclosure provides an aqueous dispersion containing an acid-modified polyolefin resin (A), a nonionic surfactant (B), and a basic compound (C). The melting point of the acid-modified polyolefin resin (A) as measured by differential scanning calorimetry (DSC) is 60-110° C. The nonionic surfactant (B) contains at least one selected from the group consisting of polyoxyalkylene alkyl ethers having a specific structure and polyoxyalkylene alkyl amines having a specific structure.

Description

Aqueous dispersion

[0001] The present disclosure relates to an aqueous dispersion.

[0002] Conventionally, polyolefin resins such as polypropylene and polyethylene have been used as base materials for automobile parts, films, molded articles, etc. because they are inexpensive and have excellent properties such as moldability, chemical resistance, water resistance, and electrical properties.

[0003] Since polyolefin base materials are crystalline and nonpolar, it is difficult to apply coating or adhesion. For this reason, for coating, printing, film lamination, and adhesion of polyolefin base materials, paints, inks, adhesives, primers, etc. based on polyolefin resins with the same main skeleton have been used from the viewpoint of adhesion.

[0004] Since polyolefin resins are generally dissolved using organic solvents, in recent years, resin dispersions in which polyolefin resins are stably dispersed in an aqueous medium have been proposed in consideration of environmental and hygienic aspects (for example, Patent Document 1, Patent Document 2, Patent Document 3).

[0005] Patent Document 1 describes an aqueous dispersion in which acid-modified chlorinated polyolefin can be dispersed in water by using an ether-based solvent and a basic compound without using an emulsifier. Patent Document 2 describes an aqueous dispersion in which a hydrophilic polymer is bonded to a polyolefin resin at a predetermined ratio and dispersed in water. Further, Patent Document 3 describes an aqueous dispersion having adhesion and dispersion stability by combining ammonia and a surfactant.

[0006] Japanese Patent Application Laid-Open No. 2004-18659, Japanese Patent Application Laid-Open No. 2007-246871, Japanese Patent Application Laid-Open No. 2008-214414

[0007] However, these aqueous dispersions have a problem of poor storage stability when mixed with an organic solvent. Specifically, it has been very difficult to uniformly and stably disperse the above aqueous dispersion in a fine state in an organic solvent and to maintain the mixing stability over time between the above aqueous resin dispersion and the organic solvent.

[0008] The present disclosure has been made in view of the above, and an object thereof is to provide an aqueous dispersion having good mixing stability with an organic solvent, excellent adhesion to a polyolefin substrate, and good water resistance.

[0009] The present disclosure includes the subject matters described in the following items. An alkyl group. Item 1. An aqueous dispersion containing an acid-modified polyolefin resin (A), a nonionic surfactant (B), and a basic compound (C), wherein the melting point of the acid-modified polyolefin resin (A) measured by a differential scanning calorimeter (DSC) is 60°C or higher and 110°C or lower, and the nonionic surfactant (B) contains at least one selected from the group consisting of a polyoxyalkylene alkyl ether represented by the following formula (1) and a polyoxyalkylene alkylamine represented by the following formula (2). (In formula (1), R １ represents a linear or branched alkyl group having 20 to 30 carbon atoms. PO represents -CH ２ CH(CH ３ ), or -CH ２ CH ２ CH ２ O-. EO represents -CH ２ CH ２ O-. k represents an integer of 0 or more. l represents an integer of 20 or more and 40 or less.) (In formula (2), R ２ represents a linear or branched alkyl group having 20 to 30 carbon atoms. PO represents -CH ２ CH(CH ３ ), or -CH ２ CH ２ CH ２ O-. EO represents -CH ２ CH ２ O-. m represents an integer of 0 or more. n + q represents an integer of 20 or more and 40 or less. p represents an integer of 0 or more.)

[0010] The aqueous dispersion of the present disclosure has good mixing stability with an organic solvent, excellent adhesion to a polyolefin substrate, and good water resistance. Since the aqueous dispersion of the present disclosure has such characteristics, it can be suitably used for various applications.

[0011] Preferred embodiments of this disclosure are described in detail below. The descriptions of constituent elements below may be based on representative embodiments and specific examples, but this disclosure is not limited to such embodiments.

[0012] In this disclosure, the expressions “contains” and “includes” include the concepts of “contains,” “includes,” “substantially consists of,” and “consistes of only.”

[0013] In the numerical ranges described in stages in this disclosure, the upper or lower limit of a numerical range in one stage can be arbitrarily combined with the upper or lower limit of a numerical range in another stage. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with values ​​shown in the examples or values ​​that can be uniquely derived from the examples. In addition, in this disclosure, numbers connected by "~" mean a numerical range that includes the numbers before and after "~" as the lower and upper limits.

[0014] In this disclosure, “A and / or B” means “either A or B” or “both A and B,” and more specifically, “A,” “B,” or “A and B.”

[0015] In this disclosure, "n-" means "normal," "sec-" means "secondary," and "tert-" means "tertiary."

[0016] In this disclosure, "(meth)acrylic" encompasses both acrylic and methacrylic, and "(meth)acrylate" encompasses both acrylate and methacrylate.

[0017] 1. Aqueous Dispersion The aqueous dispersion of this disclosure comprises the following components (I), (II), and (III): (I) an acid-modified polyolefin resin (A), a nonionic surfactant (B), and a basic compound (C). (II) the melting point of the acid-modified polyolefin resin (A), as measured by differential scanning calorimeter (DSC), is 60°C or higher and 110°C or lower. (III) the nonionic surfactant (B) contains at least one selected from the group consisting of polyoxyalkylene alkyl ethers represented by the following formula (1) and polyoxyalkylene alkylamines represented by the following formula (2). (In formula (1), R １ represents a linear or branched alkyl group having 20 to 30 carbon atoms. PO represents -CH ２ CH (CH ３ ) O-, or -CH ２ CH ２ CH ２ It indicates O-. EO is -CH ２ CH ２ (This indicates O-. k represents a non-negative integer. l represents an integer between 20 and 40.) (In formula (2), R ２ represents a linear or branched alkyl group having 20 to 30 carbon atoms. PO represents -CH ２ CH (CH ３ ) O-, or -CH ２ CH ２ CH ２ It indicates O-. EO is -CH ２ CH ２ (O- indicates a negative value. m represents a non-negative integer. n+q represents an integer between 20 and 40 (inclusive). p represents a non-negative integer.)

[0018] The aqueous dispersion of this disclosure, having the above-described configurations (I) to (III), exhibits good mixing stability with organic solvents, excellent adhesion to polyolefin substrates (particularly polypropylene substrates), and good water resistance. Because of these properties, the aqueous dispersion of this disclosure can be suitably used in various applications (e.g., paints, inks, adhesives, primers, etc.).

[0019] <Acid-modified polyolefin resin (A)> This disclosure contains an acid-modified polyolefin resin (A) as an essential component.

[0020] In one embodiment of the present disclosure, the acid-modified polyolefin resin (A) is preferably a polymer obtained by graft polymerization of an α,β-unsaturated carboxylic acid and / or its acid anhydride onto a polyolefin resin. In other words, in one embodiment of the present disclosure, the acid-modified polyolefin resin (A) is preferably a graft polymer having a structure in which an α,β-unsaturated carboxylic acid and / or its acid anhydride is grafted onto a polyolefin resin.

[0021] Examples of polyolefin resins include homopolyethylene (a homopolymer of ethylene), homopolypropylene (a homopolymer of propylene), and propylene-α-olefin copolymers. These polyolefin resins can be used individually or in combination of two or more. In one embodiment of this disclosure, the polyolefin resin is preferably homopolypropylene and / or propylene-α-olefin copolymer.

[0022] In one embodiment of the present disclosure, it is more preferable that the acid-modified polyolefin resin (A) is a graft polymer having a structure in which an α,β-unsaturated carboxylic acid or its acid anhydride is grafted onto a propylene-α-olefin copolymer.

[0023] Propylene-α-olefin copolymers are obtained by copolymerizing propylene with an α-olefin. Examples of α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-hexadecene, 4-methyl-1-pentene, vinyl acetate, and the like. These α-olefins can be used individually or in combination of two or more. In one embodiment of this disclosure, the α-olefin in the propylene-α-olefin copolymer is preferably ethylene and / or 1-butene.

[0024] In one embodiment of the present disclosure, the content of the propylene component in the propylene-α-olefin copolymer is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, still more preferably 80 mol% or more, even more preferably 85 mol% or more, particularly preferably 90 mol% or more, and most preferably 95 mol% or more. When the content of the propylene component in the propylene-α-olefin copolymer is 50 mol% or more, the adhesion of the aqueous dispersion to the polyolefin substrate is further improved.

[0025] Examples of α,β-unsaturated carboxylic acids and / or their acid anhydrides that can be graft-polymerized onto polyolefin resins include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, mesaconic acid, citraconic acid, citraconic anhydride, aconitic acid, and aconitic anhydride. In one embodiment of this disclosure, it is preferable that an α,β-unsaturated carboxylic acid acid anhydride is graft-polymerized onto the polyolefin resin, and it is more preferable that maleic anhydride is graft-polymerized.

[0026] In one embodiment of the present disclosure, the acid-modified polyolefin resin (A) is preferably at least one selected from the group consisting of maleic anhydride-modified homopolypropylene, maleic anhydride-modified propylene-ethylene copolymer, maleic anhydride-modified propylene-1-butene copolymer, and maleic anhydride-modified propylene-ethylene-1-butene copolymer. In one embodiment of the present disclosure, the acid-modified polyolefin resin (A) is more preferably at least one selected from the group consisting of maleic anhydride-modified propylene-ethylene copolymer, maleic anhydride-modified propylene-1-butene copolymer, and maleic anhydride-modified propylene-ethylene-1-butene copolymer.

[0027] In one embodiment of the present disclosure, the acid-modified polyolefin resin (A) preferably further has a structure in which radical polymerizable monomers are grafted. In other words, in one embodiment of the present disclosure, the acid-modified polyolefin resin (A) preferably is a graft polymer having a structure in which α,β-unsaturated carboxylic acids and / or their acid anhydrides are grafted onto a polyolefin resin, and a structure in which radical polymerizable monomers are grafted onto it.

[0028] Examples of radically polymerizable monomers include (meth)acrylic compounds and vinyl compounds. A (meth)acrylic compound is a compound that contains at least one (meth)acryloyl group in its molecule. Examples of radically polymerizable monomers include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, cyclohexyl (meth)acrylate, hydroxyethyl (meth)acrylate, isobornyl (meth)acrylate, glycidyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and N,N-dimethylaminoethyl (meth) Examples include acrylates, acetoacetoxyethyl (meth)acrylate, N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-propyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, N-isobutyl (meth)acrylamide, N-tert-butyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N-methylene-bis(meth)acrylamide, N-methylol (meth)acrylamide, hydroxyethyl (meth)acrylamide, (meth)acryloylmorpholine, n-butyl vinyl ether, 4-hydroxybutyl vinyl ether, dodecyl vinyl ether, etc. Preferred radical polymerizable monomers are methyl (meth)acrylate, ethyl (meth)acrylate, cyclohexyl (meth)acrylate, and lauryl (meth)acrylate, with methacrylate being more preferred. These radical polymerizable monomers can be used individually or in combination of two or more, and their mixing ratio can be freely determined.

[0029] In one embodiment of this disclosure, the polyolefin resin is typically a petroleum-derived polyolefin resin. A petroleum-derived polyolefin resin is a polyolefin resin synthesized from petroleum-derived olefins. Petroleum-derived olefins are, for example, olefins produced by thermal decomposition of petrochemical raw materials such as naphtha, ethane, LPG (Liquid Petroleum Gas), NGL (Natural Gas Liquid), and gas oil.

[0030] In one embodiment of this disclosure, a bio-derived polyolefin resin may be used instead of a petroleum-derived polyolefin resin. A bio-derived polyolefin resin means a polyolefin resin produced from biological resources (biomass). Biomass means that which is formed from renewable, bio-derived organic resources, excluding fossil resources.

[0031] When using bio-derived polyolefin resins, it is preferable that the polyolefin resin contains propylene structural units. When using bio-derived polyolefin resins, the biomass content of the polyolefin resin is usually 25% or more, preferably 27% or more, and more preferably 30% or more. The upper limit of the biomass content is not particularly limited, as long as it is 100% or less. The biomass content of the polyolefin resin can be calculated, for example, from the carbon isotope content with mass number 14, measured in accordance with ASTM D6866.

[0032] A wide range of known methods can be used for graft polymerization of α,β-unsaturated carboxylic acids and / or their acid anhydrides onto polyolefin resins. Examples of such methods include a method in which the polyolefin resin is heated above its melting point in the presence of a radical generator and reacted with α,β-unsaturated carboxylic acids and / or their acid anhydrides (melt method), and a method in which the polyolefin resin is dissolved in an organic solvent and then heated and stirred in the presence of a radical generator to react with α,β-unsaturated carboxylic acids and / or their acid anhydrides (solution method).

[0033] As a radical generator, it is preferable to use an organic peroxide or an azonitrile compound. Examples of organic peroxides include di-tert-butyl peroxyphthalate, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, methyl ethyl ketone peroxide, di-tert-butyl peroxide, lauroyl peroxide, and other peroxides; and azonitrile compounds such as azobisisobutyronitrile and azobisisopropionitrile.

[0034] In one embodiment of the present disclosure, the content of α,β-unsaturated carboxylic acid and / or its acid anhydride in the acid-modified polyolefin resin (A) (amount of acid modification) is preferably 0.5% by mass or more, more preferably 0.6% by mass or more, and even more preferably 0.7% by mass or more, based on 100% by mass of the acid-modified polyolefin resin (A). Also in one embodiment of the present disclosure, the amount of acid modification is preferably 2.0% by mass or less, more preferably 1.8% by mass or less, and even more preferably 1.5% by mass or less, based on 100% by mass of the acid-modified polyolefin resin (A). When the amount of acid modification is 0.5% by mass or more, based on 100% by mass of the acid-modified polyolefin resin (A), the dispersion stability of the acid-modified polyolefin resin (A) in an aqueous medium is further improved, and when the amount of acid modification is 2.0% by mass or less, based on 100% by mass of the acid-modified polyolefin resin (A), the adhesion of the aqueous dispersion to the polyolefin substrate and the water resistance are further improved.

[0035] In one embodiment of the present disclosure, the acid-modified polyolefin resin (A) may be further chlorinated. When the acid-modified polyolefin resin (A) is chlorinated, the lower limit of the chlorine content in the acid-modified chlorinated polyolefin resin is preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more, based on 100% by mass of the acid-modified chlorinated polyolefin resin, from the viewpoint of improving emulsification and adhesion to the polyolefin substrate. When the lower limit of the chlorine content is 5% by mass or more, based on 100% by mass of the acid-modified chlorinated polyolefin resin, the dispersibility of the acid-modified chlorinated polyolefin resin in an aqueous medium becomes better and it becomes easier to emulsify. The upper limit of the chlorine content is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, and particularly preferably 25% by mass or less, based on 100% by mass of the acid-modified chlorinated polyolefin resin. When the upper limit of the chlorine content is 40% by mass or less, with the acid-modified chlorinated polyolefin resin being 100% by mass, the crystallinity of the acid-modified chlorinated polyolefin resin increases, which strengthens the cohesive force and tends to further improve the adhesion of the aqueous dispersion.

[0036] One method for chlorinating acid-modified polyolefin resins is to introduce chlorine atoms by blowing chlorine gas into the acid-modified polyolefin resin. More specifically, the acid-modified polyolefin resin can be dispersed or dissolved in a solvent as needed, and then chlorine can be carried out by blowing chlorine gas into it at a temperature of 50 to 150°C under pressurized or atmospheric pressure in the presence of a catalyst or under ultraviolet irradiation, and allowing the reaction to proceed.

[0037] Examples of solvents used for chlorinating acid-modified polyolefin resins include water and chlorine-based solvents (e.g., chloroform, methylene chloride, carbon tetrachloride, etc.), with chlorine-based solvents being preferred. The chlorine-based solvent may be removed by distillation under reduced pressure at the end of chlorination, or replaced with another organic solvent. Examples of catalysts include radical initiators.

[0038] Examples of catalysts used in the chlorination of acid-modified polyolefin resins include radical initiators. Examples of radical initiators include tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyoctoate, di-tert-butylperoxide, and dicumylperoxide.

[0039] The chlorine content of acid-modified chlorinated polyolefin resin can be measured in accordance with JIS K-7229-1995.

[0040] In one embodiment of this disclosure, the weight-average molecular weight (Mw) of the acid-modified polyolefin resin (A) is preferably 50,000 or more, more preferably 70,000 or more, and particularly preferably 80,000 or more. When the weight-average molecular weight (Mw) of the acid-modified polyolefin resin (A) is 50,000 or more, the cohesive force of the acid-modified polyolefin resin (A) becomes stronger, and the adhesion of the aqueous dispersion becomes good. Furthermore, the upper limit is preferably 200,000 or less, more preferably 180,000 or less, and even more preferably 160,000 or less. When the weight-average molecular weight (Mw) of the acid-modified polyolefin resin (A) is 200,000 or less, the solubility of the acid-modified polyolefin resin (A) in the medium becomes good, and the preparation of the aqueous dispersion tends to be easier.

[0041] The weight-average molecular weight (Mw) of acid-modified polyolefin resin (A) can be measured by gel permeation chromatography (GPC). For example, the measurement can be performed using a Waters Japan Gel Permeation Chromatography Alliance e2695 (standard substance: polystyrene resin, mobile phase: tetrahydrofuran, column: Shodex KF-806 + KF-803, column temperature: 40°C, flow rate: 1.0 ml / min, detector: photodiode array detector (wavelength 254 nm = ultraviolet)).

[0042] In one embodiment of this disclosure, the acid-modified polyolefin resin (A) is preferably crystalline. When the acid-modified polyolefin resin (A) is crystalline, the mixing stability between the aqueous dispersion and the organic solvent tends to be even better compared to when it is amorphous. Furthermore, when the acid-modified polyolefin resin (A) is crystalline, the cohesive force of the acid-modified polyolefin resin (A) is further improved, resulting in improved adhesion of the aqueous dispersion to the polyolefin substrate and improved water resistance.

[0043] In this disclosure, crystallinity refers to a material that shows a clear melting peak when heated from -50°C to 200°C at a rate of 10°C / min using a differential scanning calorimeter (hereinafter also referred to as DSC; DSC2500, manufactured by T.A. Instruments Japan). The melting point is measured using a DSC, where the material is heated and melted at a rate of 10°C / min, cooled and converted back into resin, and then heated and melted again. The value is obtained from the top temperature and area of ​​the melting peak.

[0044] In this disclosure, the melting point of the acid-modified polyolefin resin (A), as measured by DSC, is 60°C or higher and 110°C or lower. Preferably, the melting point of the acid-modified polyolefin resin (A) is 65°C or higher and 105°C or lower, and more preferably 70°C or higher and 100°C or lower. In this disclosure, because the melting point of the acid-modified polyolefin resin (A) is 60°C or higher and 110°C or lower, the acid-modified polyolefin resin (A) has excellent emulsification properties, and the film-forming properties of the aqueous dispersion and the cohesive force due to crystallization during film formation are favorable. Therefore, the aqueous dispersion has excellent adhesion to the polyolefin substrate and good water resistance.

[0045] In one embodiment of the present disclosure, the acid-modified polyolefin resin (A) is preferably an acid-modified non-chlorinated polyolefin resin or an acid-modified chlorinated polyolefin resin.

[0046] <Nonionic surfactant (B)> The aqueous dispersion of the present disclosure contains, as an essential component, at least one nonionic surfactant (B) selected from the group consisting of polyoxyalkylene alkyl ethers represented by the following formula (1) and polyoxyalkylene alkylamines represented by the following formula (2).

[0047] In formula (1), R １ R represents a linear or branched alkyl group having 20 to 30 carbon atoms (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30). In formula (1), R １ R is preferably a linear or branched alkyl group having 20 to 25 carbon atoms (20, 21, 22, 23, 24, or 25), and more preferably a branched alkyl group having 20 to 25 carbon atoms (20, 21, 22, 23, 24, or 25). In formula (1), R １ However, by using linear or branched alkyl groups with 20 to 30 carbon atoms, the dispersion stability of the polyolefin resin particles is further improved, and the stability when the aqueous dispersion is mixed with an organic solvent is further improved.

[0048] In equation (1), PO is -CH ２ CH (CH ３ ) O-, or -CH ２ CH ２ CH ２ O- indicates, and EO is -CH ２ CH ２ In formula (1), l is an integer between 0 and 40 (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40). Preferably, l is an integer between 20 and 30 (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30), and more preferably, l is an integer between 20 and 25 (20, 21, 22, 23, 24, or 25). In formula (1), if l is an integer between 20 and 40, the stability when the aqueous dispersion is mixed with the organic solvent is further improved. In formula (1), the upper limit of k is not limited, but for example, it is 40 or less.

[0049] In one embodiment of the present disclosure, in formula (1), k is preferably an integer between 0 and 40, more preferably an integer between 0 and 30, even more preferably an integer between 0 and 20, even more preferably an integer between 0 and 10, and particularly preferably 0.

[0050] In formula (2), R ２R represents a linear or branched alkyl group having 20 to 30 carbon atoms (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30). In formula (2), R ２ The alkyl group is preferably a linear or branched alkyl group of 20 to 25 (20, 21, 22, 23, 24, or 25), and more preferably a branched alkyl group of 20 to 25 (20, 21, 22, 23, 24, or 25). In formula (2), R ２ However, by using linear or branched alkyl groups with 20 to 30 carbon atoms, the dispersion stability of the polyolefin resin particles is further improved, and the stability when the aqueous dispersion is mixed with an organic solvent is further improved.

[0051] In equation (2), PO is -CH ２ CH (CH ３ ) O-, or -CH ２ CH ２ CH ２ O- indicates, and EO is -CH ２ CH ２ In formula (2), n+q is an integer between 20 and 30 (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40), and p is an integer between 0 and 40. In formula (2), n+q is preferably an integer between 20 and 30 (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30), and more preferably an integer between 20 and 25 (20, 21, 22, 23, 24, or 25). In formula (2), when n+q is an integer between 20 and 40, the stability when the aqueous dispersion is mixed with the organic solvent is further improved. In equation (2), there are no upper limits for both m and p, but for example, both are 40 or less.

[0052] In one embodiment of the present disclosure, in formula (2), both m and p are preferably integers between 0 and 40, more preferably integers between 0 and 30, even more preferably integers between 0 and 20, even more preferably integers between 0 and 10, and particularly preferably 0.

[0053] In one embodiment of the present disclosure, the nonionic surfactant (B) preferably contains a polyoxyalkylene alkyl ether represented by formula (1) from the viewpoint of further improving the dispersion stability and handling of the aqueous dispersion. In this case, the effect on the pH of the aqueous dispersion is reduced, and the mixing stability of the aqueous dispersion with the organic solvent is further improved, so that the aqueous dispersion can be used more suitably in various applications (e.g., paints, inks, adhesives, primers, etc.).

[0054] In one embodiment of the present disclosure, the nonionic surfactant (B) may also include nonionic surfactants other than the polyoxyalkylene alkyl ether represented by formula (1) and the polyoxyalkylene alkylamine represented by formula (2), provided that the effects of the present disclosure are not impaired. Furthermore, the nonionic surfactant (B) may also include at least one surfactant selected from the group consisting of anionic surfactants, cationic surfactants, and amphoteric surfactants, provided that the effects of the present disclosure are not impaired.

[0055] R in equation (1) １ and R in equation (2) ２ Examples of such groups include arachidyl group, octyldodecyl group, behenyl group, lignoceryl group, decyltetradecyl group, and oleylcetyl group.

[0056] In the nonionic surfactant (B) of this disclosure, examples of the polyoxyalkylene alkyl ether represented by formula (1) include polyoxyethylene arachidyl ether, polyoxyethylene octyldodecyl ether, polyoxyethylene behenyl ether, polyoxyethylene decyltetradecyl ether, and polyoxyethylene polyoxypropylene decyltetradecyl ether, which can be used individually or in combination of two or more.

[0057] In the nonionic surfactant (B) of this disclosure, examples of the polyoxyalkylene alkylamine represented by formula (2) include polyoxyethylene arachidylamine, polyoxyethylene octyldodecylamine, polyoxyethylene behenylamine, polyoxyethylene decyltetradecylamine, and polyoxyethylene polyoxypropylene decyltetradecylamine, which can be used individually or in combination of two or more.

[0058] In one embodiment of the present disclosure, the hydrophilic-lipophilic balance (HLB) value of the nonionic surfactant (B) is preferably 11.0 or more and 17.0 or less, more preferably 12.0 or more and 16.0 or less, and even more preferably 13.0 or more and 15.0 or less. When the HLB value of the nonionic surfactant (B) is 11.0 or more and 17.0 or less, the emulsifying properties of the nonionic surfactant (B) are improved, and the stability when the aqueous dispersion is mixed with the organic solvent is further improved.

[0059] In one embodiment of the present disclosure, the HLB value of at least one nonionic surfactant (B) selected from the group consisting of polyoxyalkylene alkyl ethers represented by formula (1) and polyoxyalkylene alkylamines represented by formula (2) is preferably 11.0 to 17.0, more preferably 12.0 to 16.0, and even more preferably 13.0 to 15.0. When the hydrophilic-lipophilic balance (HLB) value of at least one nonionic surfactant (B) selected from the group consisting of polyoxyalkylene alkyl ethers represented by formula (1) and polyoxyalkylene alkylamines represented by formula (2) is 11.0 to 17.0, the dispersion stability of the polyolefin resin particles is further improved, and the stability when the aqueous dispersion is mixed with an organic solvent is further improved.

[0060] In one embodiment of the present disclosure, the content of the nonionic surfactant (B) is preferably 10 parts by mass or more, more preferably 11 parts by mass or more, even more preferably 12 parts by mass or more, even more preferably 13 parts by mass or more, and particularly preferably 14 parts by mass or more, per 100 parts by mass of the acid-modified polyolefin resin (A). Furthermore, the content of the nonionic surfactant (B) is preferably 27.5 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 22.5 parts by mass or less, even more preferably 21 parts by mass or less, and particularly preferably 20 parts by mass or less, per 100 parts by mass of the acid-modified polyolefin resin (A). When the content of the nonionic surfactant (B) is 10 parts by mass or more per 100 parts by mass of the acid-modified polyolefin resin (A), the emulsifying properties and dispersion stability of the nonionic surfactant (B) are further improved, and the stability when the aqueous dispersion is mixed with an organic solvent is further improved. Furthermore, when the content of the nonionic surfactant (B) is 27.5 parts by mass or less per 100 parts by mass of the acid-modified polyolefin resin (A), the water resistance of the aqueous dispersion is further improved.

[0061] In one embodiment of the present disclosure, the content of at least one nonionic surfactant (B) selected from the group consisting of polyoxyalkylene alkyl ethers represented by formula (1) and polyoxyalkylene alkylamines represented by formula (2) is preferably 10 parts by mass or more, more preferably 11 parts by mass or more, even more preferably 12 parts by mass or more, and particularly preferably 13 parts by mass or more, per 100 parts by mass of the acid-modified polyolefin resin (A). Furthermore, the content of at least one nonionic surfactant (B) selected from the group consisting of polyoxyalkylene alkyl ethers represented by formula (1) and polyoxyalkylene alkylamines represented by formula (2) is preferably 27.5 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 22.5 parts by mass or less, even more preferably 21 parts by mass or less, and particularly preferably 20 parts by mass or less. When the content of at least one nonionic surfactant (B) selected from the group consisting of polyoxyalkylene alkyl ethers represented by formula (1) and polyoxyalkylene alkylamines represented by formula (2) is 10 parts by mass or more per 100 parts by mass of acid-modified polyolefin resin (A), the emulsifying properties and dispersion stability of the nonionic surfactant (B) are further improved, and the stability when the aqueous dispersion is mixed with an organic solvent is further improved. Furthermore, when the content of at least one nonionic surfactant (B) selected from the group consisting of polyoxyalkylene alkyl ethers represented by formula (1) and polyoxyalkylene alkylamines represented by formula (2) is 27.5 parts by mass or less per 100 parts by mass of acid-modified polyolefin resin (A), the water resistance of the aqueous dispersion is further improved.

[0062] <Basic Compound (C)> The modified polyolefin resin aqueous dispersion of this disclosure contains a basic compound (C) as an essential component. The basic compound (C) is used to neutralize the carboxyl groups of the acid-modified polyolefin resin (A), and the acid-modified polyolefin resin (A) is dispersed in an aqueous medium using a nonionic surfactant (B). By including the basic compound (C) when emulsifying the acid-modified polyolefin resin (A), the dispersibility of the acid-modified polyolefin resin (A) in the aqueous medium is improved, making it possible to obtain a stable aqueous dispersion.

[0063] In one embodiment of the present disclosure, the basic compound (C) is preferably at least one selected from the group consisting of inorganic basic compounds, organic amine compounds, and ammonia.

[0064] As one embodiment of the present disclosure, examples of basic compounds (C) include inorganic basic compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and ammonium carbonate; organic amine compounds such as triethylamine, N,N-dimethylethanolamine, aminoethanolamine, N-methyl-N,N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, allylamine, diallylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, 2-amino-2-methyl-1-propanol, and 2-dimethylamino-2-methyl-1-propanol; and ammonia. These basic compounds (C) can be used individually or in combination of two or more.

[0065] In one embodiment of the present disclosure, the basic compound (C) is preferably added in an amount of 1.0 to 4.0 times the chemical equivalent of the carboxyl groups of the acid-modified polyolefin (A), and more preferably in an amount of 1.5 to 3.5 times the chemical equivalent. When the amount of basic compound (C) added to the carboxyl groups of the acid-modified polyolefin (A) is 1.0 to 4.0 times the chemical equivalent, the dispersion stability of the aqueous dispersion is further improved.

[0066] In one embodiment of the present disclosure, the content of the basic compound (C) is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of the acid-modified polyolefin resin (A). Furthermore, the content of the basic compound (C) is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, even more preferably 7 parts by mass or less, even more preferably 6 parts by mass or less, and particularly preferably 5 parts by mass or less, per 100 parts by mass of the acid-modified polyolefin resin (A). When the content of the basic compound (C) is 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the acid-modified polyolefin resin (A), the dispersibility of the acid-modified polyolefin resin (A) can be further improved, and the dispersion stability of the aqueous dispersion is further improved without the particle size of the polyolefin resin particles becoming too large.

[0067] In one embodiment of the present disclosure, the content of the basic compound (C) is preferably 5 to 50 parts by mass, more preferably 10 to 45 parts by mass, even more preferably 15 to 40 parts by mass, and particularly preferably 20 to 37.5 parts by mass, per 100 parts by mass of the nonionic surfactant (B), in order to further improve the dispersion stability of the aqueous dispersion.

[0068] <Optional Additives> The aqueous dispersions of this disclosure may contain various additives, to the extent that they do not affect the effects of this disclosure. Examples of additives include wetting agents, thickeners, tackifiers, plasticizers, stress relievers, curing agents, curing accelerators, flame retardants, pigments, and anti-blocking agents, which can be used individually or in combination of two or more.

[0069] 2. Method for Producing Aqueous Dispersions The aqueous dispersions of this disclosure can be produced by known methods commonly used in the art. For example, an acid-modified polyolefin resin (A), a nonionic surfactant (B), an organic solvent as a melting aid, and an aqueous medium are mixed. The mixture is then melted at a temperature of 80°C to 120°C. Next, a basic compound (C) is added and the mixture is stirred at a temperature of 80°C to 120°C. Subsequently, the mixture is gradually cooled to a temperature of 30°C to 60°C, and then the aqueous dispersion can be obtained by a phase inversion emulsification method in which the organic solvent is removed by inversion to an O / W type dispersion.

[0070] In one embodiment of the present disclosure, an acid-modified polyolefin resin (A), a nonionic surfactant (B), an organic solvent as a melting aid, and an aqueous medium are added to a twin-screw extruder and melt-kneaded, and then a basic compound (C) is added and mixed. Subsequently, the mixture is cooled and the mixture is inverted into an O / W type dispersion, and an aqueous dispersion can be obtained by a phase inversion emulsification method to remove the organic solvent.

[0071] The nonionic surfactant (B) may be added, for example, before or during the emulsification of the acid-modified polyolefin resin (A), or added to the aqueous dispersion after emulsification. From the viewpoint of making the aqueous dispersion more stable, it is preferable to add the nonionic surfactant (B) before emulsification. It may also be added without dilution with water, or it may be added in the form of an aqueous solution diluted to 1 to 50% by mass. When adding and mixing after emulsification, it is preferable to add the nonionic surfactant (B) in the form of an aqueous solution diluted to 1 to 50% by mass in order to quickly mix it with the aqueous dispersion, as this allows the nonionic surfactant (B) to be quickly adsorbed onto the acid-modified polyolefin resin particles.

[0072] In one embodiment of the present disclosure, the solid content concentration of the aqueous dispersion is preferably 10 to 60% by mass, more preferably 20 to 50% by mass, and even more preferably 30 to 40% by mass, based on 100% by mass of the total mass of the aqueous dispersion, from the viewpoint of handling the aqueous dispersion. When the solid content concentration of the aqueous dispersion is 10 to 60% by mass, based on 100% by mass of the total mass of the aqueous dispersion, the dispersion stability of the aqueous dispersion is further improved, and the adhesion to the polyolefin substrate is further improved.

[0073] In one embodiment of this disclosure, the aqueous medium is preferably water. Examples of water include natural water, purified water, distilled water, deionized water, and pure water. In one embodiment of this disclosure, deionized water is particularly preferred as the aqueous medium.

[0074] In one embodiment of the present disclosure, the content of the aqueous medium is preferably 100 parts by mass or more and 1000 parts by mass or less, more preferably 150 parts by mass or more and 750 parts by mass or less, and even more preferably 200 parts by mass or more and 500 parts by mass or less, per 100 parts by mass of the acid-modified polyolefin resin (A).

[0075] Examples of organic solvents used as melting aids include alcohol compounds such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol; ketone compounds such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, and cyclohexanone; ether compounds such as tetrahydrofuran and dioxane; ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, and ethyl propionate. Examples include ester compounds such as ethyl acetate, diethyl carbonate, and dimethyl carbonate; glycol compounds such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monopropyl ether, and ethylene glycol ethyl ether acetate; aromatic hydrocarbon compounds such as benzene, toluene, and xylene; 1-methoxy-2-propanol; 1-ethoxy-2-propanol; 3-methoxy-3-methyl-1-butanol; methoxybutanol; acetonitrile; dimethylformamide; dimethylacetamide; diacetone alcohol; ethyl acetoethyl acetate; 1,2-dimethylglycerin; 1,3-dimethylglycerin; trimethylglycerin; and N-methylpyrrolidone. These organic solvents can be used individually or in combination of two or more.

[0076] In one embodiment of this disclosure, the Z-average particle size of the aqueous dispersion measured by dynamic light scattering is preferably 200 nm or less, more preferably 180 nm or less, even more preferably 150 nm or less, and still more preferably 120 nm or less. Furthermore, the Z-average particle size of the aqueous dispersion measured by dynamic light scattering is preferably 10 nm or more, more preferably 30 nm or more, even more preferably 40 nm or more, and still more preferably 50 nm or more. When the Z-average particle size of the aqueous dispersion measured by dynamic light scattering is 200 nm or less, when the aqueous dispersion is mixed with an organic solvent, the aqueous dispersion can be dispersed more finely, uniformly and stably. A specific method for measuring the Z-average particle size of the aqueous dispersion will be described in the examples below.

[0077] In one embodiment of this disclosure, the pH of the aqueous dispersion is preferably 7.0 or higher, and more preferably 8.0 or higher. Furthermore, the pH of the aqueous dispersion is preferably 10.0 or lower, and even more preferably 9.5 or lower. When the pH of the aqueous dispersion is 7.0 or higher or 10.0 or lower, the Z-average particle size and viscosity of the aqueous dispersion are favorable, and a stable aqueous dispersion can be obtained. A specific method for measuring pH will be described in the examples described later.

[0078] In one embodiment of this disclosure, the viscosity of the aqueous dispersion is preferably 1 to 100 mPa·s, and more preferably 5 to 60 mPa·s, from the viewpoint of further improving the dispersion stability and handling of the aqueous dispersion. A specific method for measuring viscosity will be described in the examples described later.

[0079] 3. Applications The aqueous dispersion of this disclosure exhibits excellent adhesion to polyolefin substrates, good water resistance, and good mixing stability with organic solvents. The aqueous dispersion of this disclosure can be used as a clear varnish as is, but it may also be used mixed with pigments or blended with other resins.

[0080] The aqueous dispersion of this disclosure exhibits good mixing stability with organic solvents, excellent adhesion to polyolefin substrates (particularly polypropylene substrates), and good water resistance. Because of these properties, the aqueous dispersion of this disclosure can be suitably used in various applications (e.g., paints, inks, adhesives, primers, etc.).

[0081] As one embodiment of the present disclosure, the aqueous dispersion can be blended with various paint additives to the extent that it does not impede adhesion to the polyolefin substrate, for the purpose of further modifying the coating performance, such as film-forming ability, coating hardness, weather resistance, and flexibility. For example, alcohol compounds such as isopropanol and 2-ethylhexanol; glycol ether compounds such as propylene glycol monomethyl ether and ethylene glycol monobutyl ether; film-forming aids, defoamers, anti-sagging agents, wetting agents, UV absorbers, etc., such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and glycol ether acetate compounds can be used.

[0082] In one embodiment of this disclosure, an aqueous dispersion of a tackifier may be added to the aqueous dispersion as needed, thereby improving the drying properties of the coating film and its adhesion to the polyolefin substrate. Examples of tackifiers include rosin, dammar, polymerized rosin, hydrogenated rosin, ester rosin, rosin-modified maleic acid resin, polyterpene resin, petroleum resin, cyclopentadiene resin, phenolic resin, xylene resin, and coumarone indene resin. By adding a tackifier, the drying properties of the coating film and the adhesion of the aqueous dispersion to the polyolefin substrate can be further improved. The amount of tackifier to add is preferably 5 to 100 parts by mass, and more preferably 10 to 50 parts by mass, of solid content per 100 parts by mass of solid content of the aqueous dispersion.

[0083] As one embodiment of this disclosure, the aqueous dispersion can be suitably used in coatings, inks, adhesives, sealants, primers, etc. for polyolefin substrates such as polypropylene, but is not limited to polyolefin substrates and can also be used to coat plastics, wood, metals, etc. Examples of polyolefin substrates include films, sheets, molded articles, etc. There are no special restrictions on the coating method.

[0084] This disclosure provides subject matter in the following embodiments: Item 1. An aqueous dispersion comprising an acid-modified polyolefin resin (A), a nonionic surfactant (B), and a basic compound (C), wherein the melting point of the acid-modified polyolefin resin (A), as measured by differential scanning calorimeter (DSC), is 60°C or higher and 110°C or lower, and the nonionic surfactant (B) contains at least one selected from the group consisting of polyoxyalkylene alkyl ethers represented by the following formula (1) and polyoxyalkylene alkylamines represented by the following formula (2). (In formula (1), R １ represents a linear or branched alkyl group having 20 to 30 carbon atoms. PO represents -CH ２ CH (CH ３ ) O-, or -CH ２ CH ２ CH ２ It indicates O-. EO is -CH ２ CH ２ (This indicates O-. k represents a non-negative integer. l represents an integer between 20 and 40.) (In formula (2), R ２ represents a linear or branched alkyl group having 20 to 30 carbon atoms. PO represents -CH ２ CH (CH ３ ) O-, or -CH ２ CH ２ CH ２ It indicates O-. EO is -CH ２ CH ２1. The nonionic surfactant (B) contains a polyoxyalkylene alkyl ether represented by formula (1). The nonionic surfactant (B) is contained in an amount of 10 to 25 parts by mass per 100 parts by mass of the acid-modified polyolefin resin (A). The nonionic surfactant (B) is contained in an amount of 10 to 25 parts by mass per 100 parts by mass of the acid-modified polyolefin resin (A). The nonionic surfactant (B) is contained in an amount of 0.5 to 2.0 of the acid-modified polyolefin resin An aqueous dispersion according to any one of claims 1 to 5, wherein the weight-average molecular weight (Mw) of the acid-modified polyolefin resin (A), as measured by GPC, is 50,000 or more and 200,000 or less. Claim 7. An aqueous dispersion according to any one of claims 1 to 6, wherein the HLB value of the nonionic surfactant (B) is 11.0 or more and 17.0 or less. Claim 8. An aqueous dispersion according to any one of claims 1 to 7, wherein the acid-modified polyolefin resin (A) is an acid-modified non-chlorinated polyolefin resin or an acid-modified chlorinated polyolefin resin. Claim 9. The aqueous dispersion according to any one of claims 1 to 8, wherein the polyolefin resin constituting the acid-modified polyolefin resin (A) is preferably at least one selected from the group consisting of homopolyethylene, homopolypropylene and propylene-α-olefin copolymer, more preferably homopolypropylene and / or propylene-α-olefin copolymer, even more preferably propylene-α-olefin copolymer, and particularly preferably at least one selected from the group consisting of propylene-ethylene copolymer, propylene-1-butene copolymer and propylene-ethylene-1-butene copolymer.Item 10. The aqueous dispersion according to Item 9, wherein the content of the propylene component in the propylene-α-olefin copolymer is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, still more preferably 80 mol% or more, even more preferably 85 mol% or more, particularly preferably 90 mol% or more, and most preferably 95 mol% or more. Item 11. The aqueous dispersion according to Item 9 or 10, wherein the α-olefin is ethylene and / or 1-butene. Item 12. The aqueous dispersion according to any one of Items 1 to 11, wherein the amount of acid modification is preferably 0.5% by mass or more and 2.0% by mass or less, more preferably 0.6% by mass or more and 1.8% by mass or less, and even more preferably 0.7% by mass or more and 1.5% by mass or less, with the acid-modified polyolefin resin (A) being 100% by mass. Item 13. The aqueous dispersion according to item 8, wherein the chlorine content is preferably 5% to 40% by mass, more preferably 7% to 35% by mass, even more preferably 8% to 30% by mass, and still more preferably 10% to 25% by mass, with the acid-modified chlorinated polyolefin resin being 100% by mass. Item 14. The aqueous dispersion according to any one of items 1 to 13, wherein the weight-average molecular weight (Mw) of the acid-modified polyolefin resin (A) is preferably 50,000 to 200,000, more preferably 70,000 to 180,000, and particularly preferably 80,000 to 160,000. Item 15. The aqueous dispersion according to any one of items 1 to 14, wherein the melting point of the acid-modified polyolefin resin (A) is preferably 65°C to 105°C, more preferably 70°C to 100°C.Item 16. The polyolefin resin constituting the acid-modified polyolefin resin (A) is preferably at least one selected from the group consisting of maleic anhydride-modified non-chlorinated homopolypropylene, maleic anhydride-modified chlorinated homopolypropylene, maleic anhydride-modified non-chlorinated propylene-ethylene copolymer, maleic anhydride-modified chlorinated propylene-ethylene copolymer, maleic anhydride-modified non-chlorinated propylene-1-butene copolymer, maleic anhydride-modified chlorinated propylene-1-butene copolymer, maleic anhydride-modified non-chlorinated propylene-ethylene-1-butene copolymer, and maleic anhydride-modified chlorinated propylene-ethylene-1-butene copolymer. More preferably, the aqueous dispersion according to any one of claims 1 to 15, which is at least one selected from the group consisting of maleic anhydride-modified non-chlorinated propylene-ethylene copolymer, maleic anhydride-modified chlorinated propylene-ethylene copolymer, maleic anhydride-modified non-chlorinated propylene-1-butene copolymer, maleic anhydride-modified chlorinated propylene-1-butene copolymer, maleic anhydride-modified non-chlorinated propylene-ethylene-1-butene copolymer, and maleic anhydride-modified chlorinated propylene-ethylene-1-butene copolymer. Claim 17. In formula (1), R. １The aqueous dispersion according to any one of claims 1 to 16, wherein, preferably, it represents a linear or branched alkyl group having 20 to 25 carbon atoms (20, 21, 22, 23, 24, or 25), and more preferably, it represents a branched alkyl group having 20 to 25 carbon atoms (20, 21, 22, 23, 24, or 25). Claim 18. The aqueous dispersion according to any one of claims 1 to 17, wherein, in formula (1), l is preferably an integer between 20 and 30 (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30), and more preferably an integer between 20 and 25 (20, 21, 22, 23, 24, or 25). Claim 19. An aqueous dispersion according to any one of claims 1 to 18, wherein k is preferably an integer between 0 and 40, more preferably an integer between 0 and 30, even more preferably an integer between 0 and 20, even more preferably an integer between 0 and 10, and particularly preferably 0. Claim 20. An aqueous dispersion according to any one of claims 1 to 19, wherein the polyoxyalkylene alkyl ether represented by formula (1) is at least one compound selected from the group consisting of polyoxyethylene arachidyl ether, polyoxyethylene octyldodecyl ether, polyoxyethylene behenyl ether, polyoxyethylene decyltetradecyl ether, and polyoxyethylene polyoxypropylene decyltetradecyl ether. Claim 21. The aqueous dispersion according to any one of claims 1 to 20, wherein the polyoxyalkylene alkylamine represented by formula (2) is at least one compound selected from the group consisting of polyoxyethylene arachidylamine, polyoxyethylene octyldodecylamine, polyoxyethylene behenylamine, polyoxyethylene decyltetradecylamine, and polyoxyethylene polyoxypropylene decyltetradecylamine. Claim 22. The aqueous dispersion according to any one of claims 1 to 21, wherein the content of the nonionic surfactant (B) is preferably 10 parts by mass or more and 27.5 parts by mass or less, more preferably 11 parts by mass or more and 25 parts by mass or less, even more preferably 12 parts by mass or more and 22.5 parts by mass or less, even more preferably 13 parts by mass or more and 21 parts by mass or less, and particularly preferably 14 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the acid-modified polyolefin resin (A).Item 23. The aqueous dispersion according to any one of items 1 to 22, wherein the basic compound (C) is at least one selected from the group consisting of inorganic basic compounds, organic amine compounds, and ammonia. Item 24. The aqueous dispersion according to any one of claims 1 to 23, wherein the basic compound (C) is an organic amine compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, triethylamine, N,N-dimethylethanolamine, aminoethanolamine, N-methyl-N,N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, allylamine, diallylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, 2-amino-2-methyl-1-propanol, 2-dimethylamino-2-methyl-1-propanol, or ammonia. Claim 25. An aqueous dispersion according to any one of claims 1 to 24, wherein the content of the basic compound (C) is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.3 parts by mass or more and 8 parts by mass or less, even more preferably 0.5 parts by mass or more and 7 parts by mass or less, even more preferably 1 part by mass or more and 6 parts by mass or less, and particularly preferably 2 parts by mass or more and 5 parts by mass or less, based on 100 parts by mass of the acid-modified polyolefin resin (A). Claim 26. An aqueous dispersion according to any one of claims 1 to 25, wherein the content of the basic compound (C) is preferably 5 parts by mass or more and 50 parts by mass or less, more preferably 10 parts by mass or more and 45 parts by mass, even more preferably 15 parts by mass or more and 40 parts by mass or less, and particularly preferably 20 parts by mass or more and 37.5 parts by mass or less, based on 100 parts by mass of the nonionic surfactant (B). Claim 27. An adhesive containing the aqueous dispersion according to any one of claims 1 to 26. Claim 28. An ink containing the aqueous dispersion according to any one of claims 1 to 26. Item 29. A paint containing an aqueous dispersion as described in any one of items 1 to 26. Item 30. A primer containing an aqueous dispersion as described in any one of items 1 to 26.

[0085] Next, the present disclosure will be specifically described by examples, but the present disclosure is not limited to these examples.

[0086] (1) Measurement of weight-average molecular weight (Mw) by GPC The weight-average molecular weight (Mw) of the acid-modified polyolefin resin was measured using a gel permeation chromatograph Alliance e2695 manufactured by Waters Japan. The measurement conditions for gel permeation chromatography (GPC) were as follows. Calibration curves were obtained by dissolving each of the following standard polystyrenes from GL Sciences Co., Ltd.—"Molecular Weight Standard (Lipophilic Polymer) MW500: Model 2012-2," "Molecular Weight Standard (Lipophilic Polymer) MW2000: Model 2012-5," "Molecular Weight Standard (Lipophilic Polymer) MW10000: Model 2012-9," "Molecular Weight Standard (Lipophilic Polymer) MW20000: Model 2013-1," "Molecular Weight Standard (Lipophilic Polymer) MW50000: Model 2013-3," and "Molecular Weight Standard (Lipophilic Polymer) MW200000: Model 2013-7"—at a concentration of 0.5% to prepare tetrahydrofuran solutions, filtering them, placing them in vials, and then measuring them. <GPC Measurement Conditions> • Standard material: Polystyrene resin (weight-average molecular weight 500, 2000, 50000, 200000) • Acid-modified polyolefin resin concentration: 0.5% by mass • Mobile phase: Tetrahydrofuran (THF) • Column: Shodex KF-806 + KF-803 • Column temperature: 40°C • Flow rate: 1.0 ml / min • Detector: Photodiode array detector (wavelength 254 nm = ultraviolet)

[0087] (2) Measurement of melting point by differential scanning calorimeter (DSC) The melting point (°C) of the acid-modified polyolefin resin was measured as follows. Specifically, in accordance with JIS K7121-2012, a DSC measuring device (TA Instrument Japan, "DSC2500") was used to heat 5 mg of the acid-modified polyolefin resin sample from -50°C to 200°C at a rate of 20°C / min, hold the molten state at 200°C for 2 minutes, then cool it down at a rate of 10°C / min and hold it at -50°C for 2 minutes, and then heat it again from -50°C to 200°C at a rate of 10°C / min until the peak of the melting appeared, which was defined as the melting point.

[0088] (3) Method for calculating the amount of maleic anhydride modification (maleic anhydride content) of acid-modified polyolefin resin The amount of maleic anhydride modification (maleic anhydride content) of acid-modified polyolefin resin was calculated based on the acid value (mgKOH / g-resin) of maleic anhydride in the acid-modified polyolefin resin. First, the acid value (mgKOH / g-resin) of maleic anhydride in the acid-modified polyolefin resin was determined using a Fourier transform infrared spectrophotometer (FT-IR) (Shimadzu Corporation, "FT-IR8200PC").

[0089] Specifically, the coefficient (f) obtained from calibration curves prepared using chloroform solutions with maleic anhydride concentrations of 0.1 mass / volume percent, 0.05 mass / volume percent, and 0.0125 mass / volume percent, and the expansion peak of the carbonyl (C=O) bond of maleic anhydride in maleic anhydride-modified polyolefin solution (a mixed solution consisting of maleic anhydride-modified polyolefin resin and chloroform) (1780 cm⁻¹) －１ Using the absorbance (I) of potassium hydroxide, the acid value (mgKOH / g-resin) of maleic anhydride in the acid-modified polyolefin resin was calculated using the following formula (i): Acid value (mgKOH / g-resin) = [Absorbance (I) × Coefficient (f) × 2 × Molecular weight of potassium hydroxide × 1000 (mg) / Molecular weight of maleic anhydride] ... Formula (i) [In formula (i), the molecular weight of maleic anhydride is 98.06, and the molecular weight of potassium hydroxide is 56.11.]

[0090] Based on the acid value calculated using the above formula (i), the amount of maleic anhydride modification (maleic anhydride content) (mass%) of the acid-modified polyolefin resin was calculated.

[0091] (4) Chlorine content of acid-modified chlorinated polyolefin resin The chlorine content (mass%) of the acid-modified chlorinated polyolefin resin was measured using the "oxygen flask combustion method" in accordance with JIS K-7229-1995, in which the acid-modified chlorinated polyolefin resin was burned in an oxygen atmosphere, the generated gaseous chlorine was absorbed with water, and the chlorine content was quantified by titration. Specifically, 5 mg of the obtained acid-modified chlorinated polyolefin resin was weighed, wrapped in filter paper, and burned inside a flask filled with oxygen containing 0.5 mL of hydrogen peroxide solution (JIS K8230) and 20 mL of deionized water. After shaking the flask for 10 minutes, the total volume of the absorption solution and the water used to wash the inside of the flask was made 80 mL and placed in a beaker. The chlorine content (mass%) of the acid-modified chlorinated polyolefin resin was measured using a potentiometric titrator with silver nitrate solution (JIS K8550).

[0092] (5) Measurement of Solid Content Concentration of Aqueous Dispersion The solid content concentration (mass%) of the aqueous dispersion was measured as follows. First, 1 g of the aqueous dispersion obtained in each example or comparative example was taken into a 50 ml glass weighing bottle and weighed accurately. Next, the weighing bottle containing the aqueous dispersion was dried in a hot air dryer at 120°C for 1 hour, and the removed weighing bottle was placed in a desiccator and left at room temperature for 30 minutes to cool. The weighing bottle was removed from the desiccator, its mass was weighed accurately, and the solid content concentration (mass%) of the aqueous dispersion was calculated from the change in mass before and after hot air drying (see formula below). Solid content concentration (mass%) of aqueous dispersion = [(Sample mass before hot air drying) - (Sample mass after hot air drying)] / (Sample mass before hot air drying) × 100

[0093] (6) Measurement of the viscosity of aqueous dispersions The viscosity (mPa·s) of the aqueous dispersions obtained in each example or comparative example was measured using a B-type viscometer (Viscometer TVB-10M manufactured by Toki Sangyo Co., Ltd.) with 100 g of aqueous dispersion under the conditions of rotor No. 21, rotation speed 60 rpm, and 25°C.

[0094] (7) Measurement of pH of aqueous dispersion The pH value of the aqueous dispersion at 25°C was measured using a "pH meter F-52" manufactured by Horiba, Ltd. The instrument was calibrated using three-point measurements with phthalate pH standard solution (pH: 4.01), neutral phosphate pH standard solution (pH: 6.86), and borate pH standard solution (pH: 9.18) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0095] (8) Measurement of Z-mean particle size of aqueous dispersion Using a Malvern "Zetasizer Nano-ZS Model ZEN3600", the Z-mean particle size (nm) of the aqueous dispersion was measured by dynamic light scattering based on the intensity distribution. Specifically, samples of the aqueous dispersion obtained in each example or comparative example, prepared to a concentration of 0.05 g / L, were measured three times at 25°C, and the average value was taken as the Z-mean particle size of the aqueous dispersion.

[0096] [Production Example 1: Production of Acid-Modified Polyolefin Resin (A-1)] 280 g of propylene-1-butene copolymer (propylene content = 70 mol%, 1-butene content = 30 mol%), 60 g of maleic anhydride, 12 g of di-tert-butyl peroxide, and 450 g of toluene were added to an autoclave equipped with a stirrer. After purging with nitrogen for 5 minutes, the temperature was raised to 140°C while heating and stirring, and the reaction was carried out at 140°C for 5 hours. After the reaction was completed, the obtained reaction solution was added to a large amount of methyl ethyl ketone to precipitate the resin. This resin was further washed several times with methyl ethyl ketone to remove unreacted maleic anhydride. The obtained resin was dried under reduced pressure to obtain acid-modified polyolefin resin (A-1). In the acid-modified polyolefin resin (A-1), the chlorine content was 0.0% by mass, the amount of maleic anhydride modification (maleic anhydride content) was 2.0% by mass, the weight-average molecular weight (Mw) was 60,000, and the melting point was 70°C.

[0097] [Production Example 2: Production of Acid-Modified Chlorinated Polyolefin Resin (A-2)] 280 g of propylene-ethylene-1-butene copolymer (propylene content = 94 mol%, ethylene content = 4 mol%, 1-butene content = 2 mol%), 20 g of maleic anhydride, 12 g of di-tert-butyl peroxide, and 450 g of toluene were added to an autoclave equipped with a stirrer. After purging with nitrogen for 5 minutes, the temperature was raised to 140°C while heating and stirring, and the reaction was carried out at 140°C for 5 hours. After the reaction was completed, the obtained reaction solution was added to a large amount of methyl ethyl ketone to precipitate the resin. This resin was further washed several times with methyl ethyl ketone to remove unreacted maleic anhydride. The obtained resin was dried under reduced pressure to obtain a solid maleic anhydride-modified polyolefin resin. Furthermore, 280 g of the obtained maleic anhydride-modified polyolefin resin and 2520 g of chloroform were placed in an autoclave equipped with a stirrer, nitrogen purging was performed for 5 minutes, and then the mixture was heated to 110°C to completely dissolve the resin. Next, 1.4 g of tert-butylperoxy-2-ethylhexanoate was added, and a predetermined amount of chlorine gas was blown in. The chloroform, which was the reaction solvent, was removed by distillation under reduced pressure and the mixture was dried to obtain acid-modified chlorinated polyolefin resin (A-2). In acid-modified chlorinated polyolefin resin (A-2), the chlorine content was 15.0% by mass, the amount of maleic anhydride modification (maleic anhydride content) was 0.7% by mass, the weight-average molecular weight (Mw) was 110,000, and the melting point was 80°C.

[0098] [Production Example 3: Production of Acid-Modified Chlorinated Polyolefin Resin (A-3)] 280 g of propylene-ethylene copolymer (propylene content = 98 mol%, ethylene content = 2 mol%), 33 g of maleic anhydride, 12 g of di-tert-butyl peroxide, and 450 g of toluene were added to an autoclave equipped with a stirrer, nitrogen purging was performed for 5 minutes, and the temperature was raised to 140°C while heating and stirring, and the reaction was carried out at 140°C for 5 hours. After the reaction was completed, the obtained reaction solution was added to a large amount of methyl ethyl ketone to precipitate the resin. This resin was further washed several times with methyl ethyl ketone to remove unreacted maleic anhydride. The obtained resin was dried under reduced pressure to obtain a solid maleic anhydride-modified polyolefin resin. 280 g of the obtained maleic anhydride-modified polyolefin resin and 2520 g of chloroform were placed in an autoclave equipped with a stirrer, nitrogen purging was performed for 5 minutes, and then the mixture was heated to 110°C to completely dissolve the resin. Next, 1.4 g of tert-butylperoxy-2-ethylhexanoate was added, and a predetermined amount of chlorine gas was blown in. The reaction solvent, chloroform, was removed by distillation under reduced pressure and the mixture was dried to obtain an acid-modified chlorinated polyolefin resin (A-3). In the acid-modified chlorinated polyolefin resin (A-3), the chlorine content was 11.0% by mass, the amount of maleic anhydride modification (maleic anhydride content) was 1.0% by mass, the weight-average molecular weight (Mw) was 90,000, and the melting point was 100°C.

[0099] [Production Example 4: Production of Acid-Modified Polyolefin Resin (A'-1)] 280 g of propylene-ethylene copolymer (propylene content = 96 mol%, ethylene content = 4 mol%), 30 g of maleic anhydride, 12 g of di-tert-butyl peroxide, and 450 g of toluene were added to an autoclave equipped with a stirrer, and after purging with nitrogen for 5 minutes, the temperature was raised to 140°C while heating and stirring, and the reaction was carried out at 140°C for 5 hours. After the reaction was completed, the obtained reaction solution was added to a large amount of methyl ethyl ketone to precipitate the resin. This resin was further washed several times with methyl ethyl ketone to remove unreacted maleic anhydride. The obtained resin was dried under reduced pressure to obtain acid-modified polyolefin resin (A'-1). In the acid-modified polyolefin resin (A'-1), the chlorine content was 0.0% by mass, the amount of maleic anhydride modification (maleic anhydride content) was 1.0% by mass, the weight-average molecular weight (Mw) was 90,000, and the melting point was 120°C.

[0100] [Production Example 5: Production of Acid-Modified Chlorinated Polyolefin Resin (A'-2)] 280 g of the acid-modified polyolefin resin (A-1) obtained in Production Example 1 and 2520 g of chloroform were placed in an autoclave equipped with a stirrer, nitrogen purging was performed for 5 minutes, and then the mixture was heated to 110°C to completely dissolve the resin. Next, 1.4 g of tert-butylperoxy-2-ethylhexanoate was added, and a predetermined amount of chlorine gas was blown in. The chloroform, which was the reaction solvent, was removed by distillation under reduced pressure and the mixture was dried to obtain the acid-modified chlorinated polyolefin resin (A'-2). In the acid-modified chlorinated polyolefin resin (A'-2), the chlorine content was 15.0% by mass, the amount of maleic anhydride modification (maleic anhydride content) was 2.0% by mass, and the weight-average molecular weight (Mw) was 60,000. On the other hand, no melting peak was observed in the DSC for the acid-modified chlorinated polyolefin resin (A'-2).

[0101] The nonionic surfactants and basic compounds used in each example and comparative example are as follows: <Nonionic surfactant (B)> ・(B-1) Polyoxyethylene behenyl ether [In formula (1), R １R represents a linear alkyl group with 22 carbon atoms, k represents 0, and l represents 20. HLB value 14.6] ・(B-2) polyoxyethylene octyldodecyl ether [In formula (1), R １ R represents a branched alkyl group with 20 carbon atoms, k represents 0, and l represents 25. (HLB value 15.7) ・(B-3) Polyoxyethylene polyoxypropylene decyltetradecyl ether [In formula (1), R １ This represents a branched alkyl group with 24 carbon atoms, and PO is -CH ２ CH (CH ３ ) Indicates O-, k indicates 6, l indicates 30. HLB value 11.1) <Nonionic surfactants (B')> ・(B'-1) Polyoxyethylene oleyl ether (linear alkyl group with 18 carbon atoms, EO moles 10, PO moles 0, HLB value 15.4) ・(B'-2) Polyoxyethylene behenyl ether (linear alkyl group with 22 carbon atoms, EO moles 10, PO moles 0, HLB value 11.5) ・(B'-3) Polyoxyethylene branched decyl ether (branched alkyl group with 10 carbon atoms, EO moles 14, PO moles 2, HLB value 15.9) <Basic compounds (C)> ・(C-1) N,N-dimethylethanolamine

[0102] [Example 1: Preparation of aqueous dispersion (a)] 100 g of the acid-modified polyolefin resin (A-1) obtained in Production Example 1, 20 g of polyoxyethylene behenyl ether as a nonionic surfactant, 40 g of toluene, 60 g of isopropanol, and 400 g of deionized water were charged into an autoclave equipped with a stirrer. The temperature was raised to 90°C and then heated and dissolved at 90°C for 1 hour. Next, 5.0 g of N,N-dimethylethanolamine was added as a basic compound and stirred at 90°C for 1 hour. After that, the mixture was gradually cooled to 40°C over 1 hour, and the organic solvent was removed by distillation under reduced pressure of 91 kPa to obtain an aqueous dispersion (a) with a solid content of 30% by mass.

[0103] [Examples 2-8: Preparation of aqueous dispersions (b)-(h)] Aqueous dispersions (b)-(h) were obtained using raw materials with the compositions shown in Table 1 in the same manner as in Example 1.

[0104] [Comparative Example 1: Preparation of Aqueous Dispersion (i)] 100 g of the acid-modified polyolefin resin (A'-1) obtained in Production Example 4, 20 g of polyoxyethylene behenyl ether as a nonionic surfactant, 40 g of toluene, 60 g of isopropanol, 40 g of tetrahydrofuran, and 400 g of deionized water were charged into an autoclave equipped with a stirrer. The temperature was raised to 110°C, and the mixture was heated and dissolved at 110°C for 1 hour. Next, 5.0 g of N,N-dimethylethanolamine was added as a basic compound, and the mixture was stirred at 110°C for 1 hour. After that, the mixture was gradually cooled to 40°C over 1 hour, and the organic solvent was removed by distillation under reduced pressure of 91 kPa to obtain an aqueous dispersion (i) with a solid content of 30% by mass.

[0105] [Comparative Example 2: Preparation of Aqueous Dispersion (j)] 100 g of the acid-modified chlorinated polyolefin resin (A'-2) obtained in Production Example 5, 30 g of polyoxyethylene behenyl ether as a nonionic surfactant, 40 g of toluene, 60 g of isopropanol, and 400 g of deionized water were charged into an autoclave equipped with a stirrer. The temperature was raised to 80°C and then heated and dissolved at 80°C for 1 hour. Next, 5.0 g of N,N-dimethylethanolamine was added and stirred at 80°C for 1 hour. After that, the temperature was gradually cooled to 40°C over 1 hour, and the organic solvent was removed by distillation under reduced pressure of 91 kPa to obtain an aqueous dispersion (j) with a solid content of 30% by mass.

[0106] [Comparative Example 3: Preparation of Aqueous Dispersion (k)] 100 g of the acid-modified chlorinated polyolefin resin (A-2) obtained in Production Example 2, 10 g of polyoxyethylene oleyl ether with 20 EO moles as a nonionic surfactant, 40 g of toluene, 60 g of isopropanol, 40 g of tetrahydrofuran, and 400 g of deionized water were charged into an autoclave equipped with a stirrer. The temperature was raised to 90°C and then heated and dissolved at 90°C for 1 hour. Next, 5.0 g of N,N-dimethylethanolamine was added and stirred at 90°C for 1 hour. After that, the temperature was gradually cooled to 40°C over 1 hour, and the organic solvent was removed by distillation under reduced pressure of 91 kPa to obtain an aqueous dispersion (k) with a solid content of 30% by mass.

[0107] [Comparative Examples 4, 5, and 6: Preparation of aqueous dispersions (l), (m), and (n)] Aqueous dispersions (l), (m), and (n) were obtained using raw materials with the compositions shown in Table 1 in the same manner as in Comparative Example 3.

[0108]

[0109] The aqueous dispersions (a) to (h) obtained in Examples 1 to 8 and the aqueous dispersions (i) to (n) obtained in Comparative Examples 1 to 6 were evaluated for the following properties. The results are shown in Table 2. In Table 2, "-" means "viscosity measurement not possible".

[0110] (Preparation of Test Panels) 100 g of the aqueous dispersion obtained in each example or comparative example was mixed with 5 g of propylene glycol-n-methyl ether as a film-forming aid and 2 g of "Dynol 604" (manufactured by Air Products Japan Co., Ltd.) as a wetting agent. The mixture was stirred with a magnetic stirrer for 30 minutes to prepare a primer coating composition. This primer coating composition was spray-coated onto a polypropylene substrate (manufactured by Nippon Test Panel Co., Ltd.) washed with isopropanol to a dry film thickness of 10 μm and dried at 80°C for 5 minutes. A 2K urethane coating (Retan PG White III, manufactured by Kansai Paint Co., Ltd.) was spray-coated on the primer coating layer of the test panel to a thickness of 40 μm to 50 μm as a protective layer. After drying at 120°C for 30 minutes, the panel was left for 24 hours in an atmosphere of 25°C and 60% relative humidity to prepare a test panel with a laminated coating film. The prepared test panel was used to evaluate the adhesion and water resistance as a coating film performance test. (1) Evaluation of adhesion 100 squares reaching the substrate were made on a test board at 1 mm intervals. Cellophane tape was pressed onto the coated surface and quickly peeled off at a 90-degree angle to the coated surface. Immediately after, new cellophane tape was pressed onto the surface and peeled off at a 90-degree angle to the coated surface. This process was repeated three times and evaluated according to the following evaluation criteria. <Evaluation Criteria> A: No peeling occurred even after repeating the process three times. B: Peeling occurred on the third attempt. C: Peeling occurred on the first or second attempt.

[0111] (2) Evaluation of water resistance The prepared test boards were immersed in 40°C hot water for 240 hours. After visually checking the appearance of the coating on the test boards for the occurrence of blisters (lifting or swelling of the coating), the adhesion was evaluated in the same manner as in (1) above. Evaluation criteria A: No blisters were observed on the surface, and no peeling occurred even after repeating the process three times. B: Blisters were observed on the surface, but no peeling occurred even after repeating the process three times. C: Blisters were observed on the surface, and peeling occurred on the first, second, or third attempt.

[0112] (3) Evaluation of Mixing Stability with Organic Solvents Mixing stability with organic solvents refers to the stability of the aqueous dispersion over time when it is mixed with an organic solvent. If the mixing stability with organic solvents is excellent or good, the aqueous dispersion remains in a fine state, the viscosity changes little, and it can be stored for a long period of time. If the mixing stability with organic solvents is poor, the viscosity of the aqueous dispersion changes significantly, gelation occurs, making long-term storage impossible, and it also becomes difficult to apply the aqueous dispersion to a substrate. The mixing stability of the aqueous dispersions obtained in each example or comparative example with organic solvents was evaluated by the viscosity change rate (%) and the Z-average particle size value shown below. Specifically, 30 g of organic solvent was added to 70 g of the aqueous dispersion obtained in each example or comparative example, and the mixture was stirred with a magnetic stirrer for 10 minutes. After stirring, the appearance of the aqueous dispersion was observed visually after standing at 25°C for 10 days to check for the occurrence of solidification or gelation. Furthermore, the viscosity of the aqueous dispersion immediately after stirring and the viscosity of the aqueous dispersion after standing at 25°C for 10 days after stirring were measured using a B-type viscometer, and the viscosity change rate (%) was calculated using the following formula (3). In addition, the Z-average particle size of the aqueous dispersion after standing at 25°C for 10 days after stirring was measured. Four types of organic solvents were used to mix with the aqueous dispersion: isopropanol, 2-ethylhexanol, propylene glycol methyl ether, and ethylene glycol-n-butyl ether. The visual observation results, the calculated viscosity change rate (%), and the Z-average particle size of the aqueous dispersion after standing at 25°C for 10 days after stirring were evaluated according to the following evaluation criteria, and this was used as an evaluation of the mixing stability with the organic solvent. Viscosity change rate (%) = {(Viscosity of aqueous dispersion after standing at 25°C for 10 days after stirring - Viscosity of aqueous dispersion immediately after stirring) / Viscosity of aqueous dispersion immediately after stirring} × 100 ... Equation (3) However, if the viscosity change rate calculated by Equation (3) is a negative number, the absolute value is taken. <Evaluation Criteria> A: No solidification or gelation occurred, the Z average particle size was 200 nm or less for all, and the viscosity change rate was less than 50% for all. B: No solidification or gelation occurred, the Z average particle size was 200 nm or less for all, there were two or more organic solvents with a viscosity change rate of less than 50%, and there was one or more organic solvents with a viscosity change rate of 50% or more and less than 100%.C: One or more organic solvents were found to have solidified or gelled, or whose viscosity could not be measured, or whose viscosity change rate was 100% or more.

[0113]

[0114] [Discussion of the results in Tables 1 and 2] The aqueous dispersions (a) to (d) and (g) obtained in Examples 1 to 4 and 7 all showed excellent adhesion and water resistance, and excellent mixing stability with organic solvents. The aqueous dispersions (e) and (f) obtained in Examples 5 and 6 both showed excellent adhesion and water resistance, and good mixing stability with organic solvents. The aqueous dispersion (h) obtained in Example 8 showed excellent adhesion and good water resistance, and excellent mixing stability with organic solvents. In contrast, the aqueous dispersion (i) obtained in Comparative Example 1 had poor adhesion and water resistance because the melting point of the acid-modified polyolefin resin was high at 120°C. The aqueous dispersion (j) obtained in Comparative Example 2 had poor water resistance and poor mixing stability with organic solvents because the acid-modified polyolefin resin was amorphous. In Comparative Example 3, the aqueous dispersion (k) showed poor mixing stability with the organic solvent because the number of alkyl carbon atoms in the nonionic surfactant used was less than 20, and the content of the nonionic surfactant was also low. In Comparative Example 4, the aqueous dispersion (l) showed poor mixing stability with the organic solvent because the number of alkyl carbon atoms in the nonionic surfactant used was less than 20. In Comparative Example 5, the aqueous dispersion (m) showed poor mixing stability with the organic solvent because the number of moles of ethylene oxide in the nonionic surfactant used was less than 20. In Comparative Example 6, the aqueous dispersion (n) showed poor mixing stability with the organic solvent because the number of alkyl carbon atoms in the nonionic surfactant used was less than 20, and the number of moles of ethylene oxide was also less than 20.

Claims

1. An aqueous dispersion comprising an acid-modified polyolefin resin (A), a nonionic surfactant (B), and a basic compound (C), wherein the melting point of the acid-modified polyolefin resin (A) measured by a differential scanning calorimeter (DSC) is 60°C or higher and 110°C or lower, and the nonionic surfactant (B) contains at least one selected from the group consisting of a polyoxyalkylene alkyl ether represented by the following formula (1) and a polyoxyalkylene alkylamine represented by the following formula (2). (In formula (1), R １ represents a linear or branched alkyl group having 20 to 30 carbon atoms. PO represents -CH ２ CH(CH ３ )O-, or -CH ２ CH ２ CH ２ O-. EO represents -CH ２ CH ２ O-. k represents an integer of 0 or more. l represents an integer of 20 or more and 40 or less.) (In formula (2), R ２ represents a linear or branched alkyl group having 20 to 30 carbon atoms. PO represents -CH ２ CH(CH ３ )O-, or -CH ２ CH ２ CH ２ O-. EO represents -CH ２ CH ２ O-. m represents an integer of 0 or more. n + q represents an integer of 20 or more and 40 or less. p represents an integer of 0 or more.) 2. The aqueous dispersion according to claim 1, wherein the nonionic surfactant (B) contains a polyoxyalkylene alkyl ether represented by formula (1).

3. The aqueous dispersion according to claim 1, wherein the content of the nonionic surfactant (B) is 10 parts by mass or more and 25 parts by mass or less per 100 parts by mass of the acid-modified polyolefin resin (A).

4. The aqueous dispersion according to claim 1, wherein the amount of acid modification is 0.5% by mass or more and 2.0% by mass or less, with the acid-modified polyolefin resin (A) being 100% by mass.

5. The aqueous dispersion according to claim 1, wherein the Z-average particle diameter measured by dynamic light scattering is 200 nm or less.

6. The aqueous dispersion according to claim 1, wherein the weight-average molecular weight (Mw) of the acid-modified polyolefin resin (A), as measured by GPC, is 50,000 or more and 200,000 or less.

7. The aqueous dispersion according to claim 1, wherein the HLB value of the nonionic surfactant (B) is 11.0 or more and 17.0 or less.

8. An adhesive containing the aqueous dispersion described in any one of claims 1 to 7.

9. An ink containing the aqueous dispersion described in any one of claims 1 to 7.

10. A paint containing the aqueous dispersion described in any one of claims 1 to 7.

11. A primer containing the aqueous dispersion described in any one of claims 1 to 7.

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