JP2016040360A - Polymer particle, polymer dispersion liquid, aqueous coating material, and coated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer dispersion liquid and an aqueous coating material capable of forming a coated film excellent in adhesiveness to various substrates, especially polyolefin substrate, water resistance, and soft feel property, and a polymer particle contained in the polymer dispersion liquid and the aqueous coating material.SOLUTION: There is provided a polymer particle containing an urethane resin (A) and a polymer (B) containing a monomer unit derived from a radical polymerizable monomer (b) in the same particle, where the radical polymerizable monomer (b) contains one or more kinds selected from a group consisting of an acrylic acid ester monomer (b1) and a methacrylic acid ester monomer (b2) having a solubility parameter calculated by a Fedors method of 20.1 (J/cm)or less of 50 to 100 mass% based on the total amount of the radical polymerizable monomer (b) and glass transition temperature (Tg) calculated by the FOX formula (1) of the polymer (B) is -35 to 57°C.SELECTED DRAWING: None

Description

  The present invention relates to polymer particles, a polymer dispersion, an aqueous coating material, and a coated product.

Conventionally, in the paint field, conversion from organic solvent-based paints to water-based paints has been attempted from the viewpoint of environmental protection and safety and health. However, water-based paints have a problem in that the coating film appearance, adhesion, weather resistance, water resistance, solvent resistance, and stain resistance are lower than those of organic solvent-based paints.
Therefore, in order to solve these problems, a coating material containing an intra-particle mixture of resins having different properties has been proposed.

For example, Patent Document 1 describes that a water-based resin composition having a two-layer structure having a urethane resin component in the outer layer portion and a vinyl polymer structure in the inner layer portion may be used as the paint.
Patent Document 2 describes an aqueous dispersion of a urethane-acrylic composite resin excellent in water resistance, strength, and elongation characteristics.
Further, in recent years, from the viewpoint of energy saving, it is required to lower the drying temperature in the drying process after painting. Accordingly, there is a demand for a coating material having adhesion and water resistance even under low temperature drying conditions. Furthermore, in automobile interior member applications and the like, there is also a demand for a paint that can provide a coating film having a soft touch when touched with a finger (that is, a coating film having soft feel).

JP 2001-354736 A JP 2002-322359 A

However, when the dispersion of the aqueous resin composition described in Patent Document 1 is used in an aqueous coating material, the water resistance and adhesion of the coating film, particularly adhesion to a polyolefin substrate, is insufficient. Furthermore, the coating film obtained from the dispersion described in Patent Document 1 is inferior in soft feel.
Moreover, patent document 2 is literature regarding the film suitable for the support body of the adhesive sheet for surface protection, and is not related with a coating material.

The present invention relates to a polymer dispersion and an aqueous coating material capable of forming a coating film excellent in adhesion, water resistance, and soft feel properties to various substrates, particularly a polyolefin substrate, and the polymer dispersion and the aqueous coating material. It aims at providing the polymer particle contained in.
Furthermore, an object of the present invention is to provide an aqueous coating material capable of forming a coating film excellent in adhesion and water resistance even under low temperature drying conditions, and a coated product coated with the aqueous coating material.

The present invention is a polymer particle comprising [1] a urethane resin (A) having the following constitution and a polymer (B) containing a monomer unit derived from a radical polymerizable monomer (b) in the same particle. And
The radical polymerizable monomer (b) is an acrylate monomer (b1), and methacrylic acid having a solubility parameter calculated by the Fedors method of 20.1 (J / cm ³ ) ^1/2 or less. 1 to 1 or more types selected from the group consisting of ester monomers (b2) is contained in an amount of 50 to 100% by mass based on the total amount of the radical polymerizable monomers (b),
The polymer particle whose glass transition temperature (Tg) computed by the following formula | equation (1) of the said polymer (B) is -35-57 degreeC.
Tg = 1 / (W ₁ / Tg ₁ + W ₂ / Tg ₂ +... + W _n / Tg _n ) (1)
In (Equation (1), Tg represents the glass transition temperature of the polymer _{(B), Tg 1, Tg} 2 ··· Tg n is the glass of the radically polymerizable monomers constituting the polymer (B) Represents transition temperature, W ₁ , W ₂ ... W _n represent mass fractions of each radical polymerizable monomer.)
[2] The polymer according to [1], wherein the solubility parameter calculated by the following formula (2) of the polymer (B) is 19.7 (J / cm ³ ) ^1/2 or less. particle.
_{SP p = 1 / (W 1} / SP m1 + W 2 / SP m2 + ··· + W n / SP mn) ··· (2)
(In Formula (2), SP _p represents the solubility parameter of the polymer (B), and SP _m1 , SP _m2 ... SP _mn represents the respective radical polymerizable monomers constituting the polymer (B). The solubility parameter calculated by the Fedors method is represented, and W ₁ , W ₂ ... W _n represent the mass fraction of each radical polymerizable monomer.)
[3] The polymer particles according to [1] or [2], wherein the glass transition temperature (Tg) calculated by the formula (1) of the polymer (B) is −5 to 45 ° C.
[4] The radical polymerizable monomer (b) contains at least the methacrylic acid ester monomer (b2),
Any of [1] to [3], wherein the methacrylic acid ester monomer (b2) contains at least one methacrylic acid ester selected from the group consisting of t-butyl methacrylate, i-butyl methacrylate and n-butyl methacrylate. Polymer particles according to claim 1.
[5] A polymer dispersion comprising the polymer particles according to any one of [1] to [4] and a dispersion medium.
[6] An aqueous coating material comprising the polymer particles according to any one of [1] to [4] and a dispersion medium.
[7] The aqueous coating material according to [6], further comprising a polyolefin polymer.
[8] A coated product to which the aqueous coating material according to [6] or [7] is applied.

According to the present invention, it is possible to form a coating film excellent in adhesion, water resistance and soft feel to various substrates, particularly polyolefin substrates.
Moreover, according to this invention, the coating film excellent in adhesiveness and water resistance can be formed also under low temperature drying conditions.

Hereinafter, the polymer particles of the present invention, a polymer dispersion containing the polymer particles, an aqueous coating material, and a coated product coated with the aqueous coating material will be sequentially described in detail.
<Polymer particles>
The polymer particles of the present invention may be referred to as a urethane resin (A) and a polymer (B) containing a monomer unit derived from the radical polymerizable monomer (b) (hereinafter simply referred to as “polymer (B)”). The radical polymerizable monomer (b) is an acrylic acid ester monomer (b1) and a solubility parameter (hereinafter referred to as Fedors method) calculated by the Fedors method. , may be described as SP _m) is 20.1 ^{(J /} cm ^{3) 1/2} or less is methacrylic acid ester monomers at least one selected from the group consisting of (b2), the radical polymerization The glass transition temperature (Tg) calculated by the following formula (1) of the polymer (B) is −35 to 57 ° C. with respect to the total amount of the polymerizable monomer (b). is there.
Tg = 1 / (W ₁ / Tg ₁ + W ₂ / Tg ₂ +... + W _n / Tg _n ) (1)
In (Equation (1), Tg represents the glass transition temperature of the polymer _{(B), Tg 1, Tg} 2 ··· Tg n is the glass of the radically polymerizable monomers constituting the polymer (B) Represents transition temperature, W ₁ , W ₂ ... W _n represent mass fractions of each radical polymerizable monomer.)
Such polymer particles are produced, for example, by a method of polymerizing a radical polymerizable monomer mixture in an aqueous dispersion containing the urethane resin (A).

[Urethane resin (A)]
The polymer particle of this invention contains a urethane resin (A) in the same particle.
In the present invention, the urethane resin (A) refers to a resin obtained by reacting a diol with a polyvalent isocyanate compound.

  A diol refers to an organic compound having two hydroxyl groups in one molecule. Specific examples include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, Relatively low molecular weight diols such as neopentyl glycol, diethylene glycol, trimethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, hexanediol, cyclohexanedimethanol; and at least one of these diols Polyester diols obtained by polycondensation with at least one dicarboxylic acid such as adipic acid, sebacic acid, itaconic acid, maleic anhydride, terephthalic acid, isophthalic acid; polyethylene glycol, poly B propylene glycol, polycaprolactone diol, polytetramethylene ether diol, polyether diols and polycarbonate diols; polybutadiene diol, hydrogenated polybutadiene diol, polyacrylate diol. In the production of the urethane resin (A), these diols may be used alone or in combination of two or more.

  The polyvalent isocyanate compound refers to an organic compound having at least two isocyanate groups in one molecule, and examples thereof include aliphatic, alicyclic and aromatic polyvalent isocyanate compounds. Specific examples of the polyvalent isocyanate compound include dicyclohexylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 2,4-tolylene diisocyanate, 2, , 6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, and the like. In the production of the urethane resin (A), these polyvalent isocyanate compounds may be used alone or in combination of two or more. Among these, aliphatic or alicyclic isocyanates are preferable because the resulting urethane resin (A) has little yellowing.

Examples of the method for producing the urethane resin (A) include a method of reacting the above-mentioned diol with isocyanate in a ether such as dioxane using a catalyst such as dibutyltin dilaurate.
The mass average molecular weight of the urethane resin (A) obtained by such a method is preferably 500 or more, more preferably 1000 or more from the viewpoint of improving the reactivity with the radical polymerizable monomer described later. Is more preferable. As an upper limit, it is preferable that it is 500,000 or less, and it is more preferable that it is 400,000 or less. That is, the mass average molecular weight of the urethane resin (A) is preferably 500 to 500,000, and more preferably 1000 to 400,000. Here, “mass average molecular weight” means a value calculated by polystyrene conversion using gel permeation chromatography.

Moreover, it is preferable to use the water dispersion liquid which disperse | distributed urethane resin (A) in water at the time of the polymer particle of this invention. In this case, the urethane resin (A) preferably has at least one acidic group of a carboxyl group or a sulfonic acid group in its structure. Thereby, since the dispersibility to the water of a urethane resin (A) becomes favorable, it is preferable.
Moreover, it is more preferable to have a sulfonic acid group in the structure from the viewpoint that the radical polymerizable monomer mixture described later can be stably polymerized in the aqueous dispersion of the urethane resin (A) during the production of the polymer particles. . As a result, the polymerization stability of the polymer particles, in particular, the emulsion stability during emulsion polymerization is improved, and the coating film obtained from the aqueous coating material containing the obtained polymer dispersion is excellent in water resistance.

The urethane resin (A) having a sulfonic acid group in the structure is prepared by reacting a polyol such as a diol or a polyvalent isocyanate compound with a compound having a sulfonic acid group or a salt thereof; a polyol having a sulfonic acid group; For example, by reacting with a polyvalent isocyanate compound.
Examples of the compound having a sulfonic acid group or a salt thereof include hydroxysulfonic acid such as 1,7-dihydroxynaphthalenesulfonic acid; 2,4-diaminobenzenesulfonic acid, 3,4-diaminobutanesulfonic acid, 3,6- Examples thereof include aminosulfonic acids such as diamino-2-toluenesulfonic acid and N- (2-aminoethyl) -2-aminoethylsulfonic acid. In the production of the urethane resin (A) having a sulfonic acid group, these compounds having a sulfonic acid group or a salt thereof may be used alone or in combination of two or more.
Examples of polyols having sulfonic acid groups include polyols containing sulfonic acid groups such as 1,4-butanediol-2-sulfonic acid; sulfonate-containing polyester polyols, sulfonate-containing polyether polyols, and sulfonate-containing polyols. Examples include sulfonate-containing polyols such as polycarbonate polyols. In the production of the urethane resin (A) having a sulfonic acid group, these polyols having a sulfonic acid group may be used alone or in combination of two or more.

As described above, the urethane resin (A) is preferably in the form of an aqueous dispersion because it can stably polymerize a radical polymerizable monomer mixture described later.
The average particle size of the urethane resin (A) in the aqueous dispersion is preferably 1000 nm or less, more preferably 500 nm or less, as the average particle size according to the cumulant analysis result. With such an average particle size, for example, the storage stability of the aqueous dispersion and the aqueous coating material, and the water resistance and solvent resistance of the coating film are further improved. The average particle diameter is preferably 10 nm or more from the viewpoint of the viscosity property of the paint and the storage stability when used in an aqueous coating material. That is, as the aqueous dispersion of the urethane resin (A), it is preferable to use an aqueous dispersion in which the urethane resin (A) having an average particle diameter of 10 to 1000 nm, preferably 10 to 500 nm is dispersed in water. .

  The content (solid content) of the urethane resin (A) in the aqueous dispersion is preferably 10% by mass or more, and more preferably 25% by mass or more. Moreover, it is preferable that it is 70 mass% or less, and it is more preferable that it is 60 mass% or less. That is, the content of the urethane resin (A) in the aqueous dispersion of the urethane resin (A) is preferably 10 to 60% by mass, and more preferably 25 to 70% by mass. With such a content, the solid content concentration of the polymer dispersion obtained by polymerizing the radical polymerizable monomer mixture in the aqueous dispersion can be adjusted to a range of 10 to 80% by mass. If the solid content concentration of the polymer dispersion is within the above range, the paintability when this is used as an aqueous coating material will be good. In addition, solid content concentration of a polymer dispersion liquid is a ratio of the quantity of the polymer particle which contains a urethane resin (A) and a polymer (B) in the same particle.

  As an aqueous dispersion of such a urethane resin (A), a commercially available urethane aqueous polymer dispersion (urethane dispersion: PUD) can be used as it is. Specifically, Daiichi Kogyo Seiyaku Co., Ltd .: Superflex 110, Superflex 150, Superflex 210, Superflex 300, Superflex 420, Superflex 460, Superflex 470, Superflex 500M, Superflex 620, Superflex 650, Superflex 740, Superflex 820, Superflex 840, F-8082D, F-2951D, manufactured by Sumika Bayer Urethane Co., Ltd .: Bihydrol UH2606, Bihydrol UH650, Bihydrol UHXP2648, Bihydrol UHXP2650, Implanil DLC-F Implanil DLN, Implanil DLP-R, Implanyl DLS, Implanil D U, Implanil XP2611, Implanil LPRSC 1380, Implanil LPRSC1537, Implanil LPRSC1554, Implanil LPRSC3040, Implanil LPDSB1069, Dainippon Ink & Chemicals, Inc .: Hydran HW-301, HW-310, HW-311, HW -312B, HW-333, HW-340, HW-350, HW-375, HW-920, HW-930, HW-940, HW-950, HW-970, AP-10, AP-20, ECOS3000, Sanyo Made by Kasei Kogyo Co., Ltd .: U-coat UWS-145, Permarin UA-150, Permarin UA-200, Permarin UA-300, Permarin UA-310, Ucourt UX-320, Permarin UA-368, Par Phosphorus UA-385, Yukot UX-2510, manufactured by Nikka Chemical Co., Ltd .: Neosticker 100C, Evaphanol HA-107C, Evaphanol HA-50C, Evaphanol HA-170, Evaphanol HA-560, ADEKA Corporation: Adekabon Examples include titer UHX-210 and Adekabon titer UHX-280.

[Polymer (B) including monomer unit derived from radical polymerizable monomer (b)]
The polymer particles of the present invention contain, in the same particle, a polymer (B) containing a monomer unit derived from the radical polymerizable monomer (b) in addition to the aforementioned urethane resin (A). Such a polymer (B) is obtained by polymerizing a monomer mixture containing the radical polymerizable monomer (b) (hereinafter sometimes simply referred to as a radical polymerizable monomer mixture). Preferably there is.
In one aspect of the present invention, the polymer (B) may be composed only of monomer units derived from the radical polymerizable monomer (b).

(Radically polymerizable monomer (b))
In the present invention, the radical polymerizable monomer is a monomer having a radical polymerizable group, and the radical polymerizable group is a radically polymerizable carbon-carbon unsaturated double bond, capable of radical polymerization. A group containing a carbon-carbon unsaturated triple bond, a ring capable of radical ring-opening polymerization, and the like.
The polymer (B) of the present invention includes a monomer unit derived from the radical polymerizable monomer (b), and the radical polymerizable monomer (b) is an acrylate monomer (b1) (hereinafter, A monomer (b1)), and a methacrylate monomer having a solubility parameter (SP _m ) calculated by the Fedors method of 20.1 (J / cm ³ ) ^1/2 or less One or more selected from the group consisting of (b2) (hereinafter sometimes simply referred to as the monomer (b2)) is 50 to 100 with respect to the total amount of the radical polymerizable monomer (b). Including mass%.

(Acrylic acid ester monomer (b1))
Examples of the acrylate monomer (b1) include methyl acrylate, ethyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, and nonyl. Alkyl acrylates having an alkyl group having 1 to 22 carbon atoms such as acrylate, tridecyl acrylate, lauryl acrylate, stearyl acrylate, and isostearyl acrylate; cycloalkyl acrylates such as cyclohexyl acrylate, methylcyclohexyl acrylate, and t-butylcyclohexyl acrylate Is mentioned. These may be used alone or in combination of two or more. Among these, as an acrylate monomer, methyl acrylate, ethyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, and 2-ethylhexyl acrylate are preferable.

(Methacrylate monomer (b2) having a solubility parameter (SP _m ) calculated by the Fedors method of 20.1 (J / cm ³ ) ^1/2 or less)
Examples of the methacrylic acid ester monomer (b2) having a solubility parameter calculated by the Fedors method of 20.1 (J / cm ³ ) ^1/2 or less include, for example, ethyl methacrylate, n-butyl methacrylate, i-butyl. Has an alkyl group having 2 to 22 carbon atoms such as methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, tridecyl methacrylate, lauryl methacrylate, stearyl methacrylate, isostearyl methacrylate Alkyl methacrylates such as cyclohexyl methacrylate, methyl cyclohexyl methacrylate, t-butyl cyclohexyl methacrylate, etc. Acrylate compounds, and the like. These may be used alone or in combination of two or more.
In one aspect of the present invention, the radical polymerizable monomer (b) contains at least the monomer (b2) from the viewpoint of excellent adhesion to various substrates, particularly polyolefin substrates. Preferably, the monomer (b2) is t-butyl methacrylate (SP _m = 18.32), i-butyl methacrylate (SP _m = 18.82) and n-butyl methacrylate (SP _m = 19.12). It is preferable that 1 or more types of methacrylic acid ester chosen from among are included.
Moreover, it is preferable that the ratio of the total amount of t-butyl methacrylate, i-butyl methacrylate, and n-butyl methacrylate is 10 to 100% by mass with respect to the total amount of the radical polymerizable monomer (b). -100 mass% is more preferable, and 50-100 mass% is the most preferable.
In one aspect of the present invention, the ratio of each monomer to the total amount of the radically polymerizable monomer (b) is determined by the amount of each monomer contained in the radically polymerizable monomer mixture at the time of producing the polymer (B). It may be a value calculated from the ratio of the monomer (that is, the charging ratio).
In the present specification, excellent adhesion means that when the aqueous coating material of the present invention is applied to a polyolefin base material and dried under low temperature drying conditions, an adhesive tape is applied and peeled off. It means that the ratio of the coating film to be peeled is 30% or less with respect to the area of the entire coating film.

(Other monomers)
In one aspect of the present invention, the radical polymerizable monomer (b) may contain other monomers in addition to the monomer (b1) and the monomer (b2).
Other monomers include, for example, methyl methacrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) ) Acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2-hydroxy-1,3-di (meth) acryloxy Propane, 2,2-bis [4- (acryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl ] Bread, 2,2-bis [4- (methacryloxy-polyethoxy) phenyl] propane, 2-hydroxy-1-acryloxy-3-methacryloxypropane, ethylene oxide modified bisphenol A di (meth) acrylate, propylene oxide modified bisphenol A di (Meth) acrylate, ethylene oxide-modified hydrogenated bisphenol A di (meth) acrylate, propylene oxide-modified hydrogenated bisphenol A di (meth) acrylate, diglycidyl ether of bisphenol A and hydroxyalkyl (meth) such as hydroxy (meth) acrylate Diester compound of diol and (meth) acrylic acid such as epoxy (meth) acrylate to which acrylate is added, polyoxyalkylenated bisphenol A di (meth) acrylate; Limethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) A compound having three or more hydroxyl groups per molecule such as acrylate and dipentaerythritol hexa (meth) acrylate and a polyester compound of (meth) acrylic acid; allyl (meth) acrylate, divinylbenzene, triallyl isocyanurate, iso (terephthalate) ) Diallyl phthalate, diallyl isocyanurate, diallyl tris (2-acryloyloxyethylene) isocyanurate, ε-caprolactone modified tris (acrylo) Monomers having two or more radically polymerizable groups such as conjugated diene monomers such as (ciethyl) isocyanurate, 1,3-butadiene, isoprene, acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid Acid group-containing radical polymerizable monomers such as β-carboxyethyl acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl ( Hydroxyl-containing radical polymerizable monomers such as hydroxyl-containing radical polymerizable monomers such as meth) acrylate, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyltrimethoxysilane, and the like Body; Methoxypolyethylene oxide mono (meta) Alkyl group-terminated polyalkylene oxide group-containing radical polymerizable monomers such as acrylate; Oxirane group-containing radical polymerizable monomers such as glycidyl (meth) acrylate; Carbonyl group-containing ethylenically unsaturated monomers such as diacetone acrylamide Body: 1,2,2,6,6-pentamethyl-4-piperidyl (meth) acrylate, 2,2,6,6-pentamethyl-4-piperidyl (meth) acrylate, etc. have light stabilizing action (meth) Acrylate; (meth) acrylate having ultraviolet absorbing component such as 2- [2′-hydroxy-5 ′-(meth) acryloyloxyethylphenyl] -2H-benzotriazole; amino such as 2-aminoethyl (meth) acrylate Alkyl (meth) acrylates; amide group-containing polymers such as (meth) acrylamide Cal-polymerizable monomers; metal-containing radical polymerizable monomers such as zinc di (meth) acrylate; (meth) acrylonitrile, benzyl (meth) acrylate, isobornyl (meth) acrylate, methoxyethyl (meth) acrylate, etc. Other (meth) acrylic monomers; aromatic vinyl monomers such as styrene and methylstyrene; radical polymerizable monomers such as vinyl acetate, vinyl chloride, and ethylene. These monomers may be used alone or in combination of two or more.
The proportion of the other monomer is preferably 0 to 45 mass%, more preferably 0 to 30 mass%, based on the total amount of the radical polymerizable monomer (b) constituting the polymer (B).
In one aspect of the present invention, when methyl methacrylate is used as the other monomer described above, the proportion of monomer units derived from methyl methacrylate in the polymer (B) is from the viewpoint of adhesion to the polyolefin substrate. The total amount of the radically polymerizable monomer (b) is preferably 45% by mass or less, and more preferably 25% by mass or less.

Furthermore, the polymer (B) has a glass transition temperature (Tg) calculated from the following formula (1) (calculation formula of FOX) of −35 to 57 ° C. -30 to 50 ° C is preferable, and -5 to 45 ° C is more preferable from the viewpoint of improving the adhesion to the substrate, particularly the adhesion to the polyolefin substrate and the soft feel.
Tg = 1 / (W ₁ / Tg ₁ + W ₂ / Tg ₂ +... + W _n / Tg _n ) (1)
In (Equation (1), Tg represents the glass transition temperature of the polymer _{(B), Tg 1, Tg} 2 ··· Tg n is the glass of the radically polymerizable monomers constituting the polymer (B) Represents transition temperature, W ₁ , W ₂ ... W _n represent mass fractions of each radical polymerizable monomer.)

Furthermore, the solubility parameter (hereinafter also referred to as SP _p ) calculated by the following formula (2) of the polymer (B) of the present invention is 19.7 (J / cm ³ ) ^1/2 or less. Preferably there is. From the viewpoint of improving adhesion to a substrate, particularly adhesion to a polyolefin substrate, 19.6 (J / cm ³ ) ^1/2 or less is more preferable, and most preferably 19.2 (J / cm ³ ) ^1/2. It is as follows. Moreover, 18.9 (J / cm < ³ >) ^<1/2 > or more is preferable from the point of water resistance improvement.
That is, the solubility parameter (SP _p ) of the polymer (B) is preferably 18.9 to 19.7 (J / cm ³ ) ^1/2 , and 18.9 to 19.6 (J / cm ³ ) ^{1 / 2} is more preferable, and 18.9 to 19.2 (J / cm ³ ) ^1/2 is most preferable.
The solubility parameter (SP _p value) of the polymer (B) is calculated by the following formula (2).
_{SP p = 1 / (W 1} / SP m1 + W 2 / SP m2 + ··· + W n / SP mn) ··· (2)
(In Formula (2), SP _p represents the solubility parameter of the polymer (B), and SP _m1 , SP _m2 ... SP _mn represents the respective radical polymerizable monomers constituting the polymer (B). The solubility parameter calculated by the Fedors method is represented, and W ₁ , W ₂ ... W _n represent the mass fraction of each radical polymerizable monomer.)

  In the polymer particles of the present invention, the mass ratio of the urethane resin (A) and the polymer (B) described above is compatible with the urethane resin (A) and the polymer (B), adhesion to the substrate, From the viewpoint of improving water resistance and solvent resistance, it is preferable that urethane resin (A) / polymer (B) = (10 to 90) / (90 to 10). From the point which the adhesiveness of a coating film improves, More preferably, it is (20-80) / (80-20), Most preferably, it is (30-70) / (70-30).

The average particle size of the polymer particles of the present invention is preferably 10 to 1000 nm from the viewpoints of film formability, adhesion, water resistance, water absorption resistance, hydrolysis resistance, and solvent resistance of the coating film. It is more preferably 20 to 500 nm, and further preferably 30 to 400 nm.
In the present specification, the average particle size of the polymer particles is a value calculated by cumulant analysis after measurement at room temperature using a dense particle size analyzer FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.

<Polymer dispersion>
The polymer dispersion of the present invention contains the aforementioned polymer particles and a dispersion medium.
As the dispersion medium, those similar to those used in the aqueous coating material described later can be used.
The solid content concentration (polymer particle concentration) in the polymer dispersion of the present invention is preferably 10 to 80% by mass, more preferably 20 to 70% by mass. If the solid content concentration in the polymer dispersion is 10 to 80% by mass, it is preferable because it is easy to adjust the viscosity when preparing an aqueous coating material and the final solid content.

<Method for producing polymer dispersion>
The polymer particles containing the urethane resin (A) and the polymer (B) of the present invention are prepared by, for example, converting a radical polymerizable monomer mixture for constituting the polymer (B) to water of the urethane resin (A). By polymerizing in the dispersion, the target weight is obtained in the form of a dispersion (polymer dispersion) in which the polymer particles containing the urethane resin (A) and the polymer (B) are dispersed in an aqueous dispersion medium. Combined particles can be obtained.
In the present specification, the “radical polymerizable monomer mixture” means containing one or more of the above-mentioned radical polymerizable monomers. That is, the radical polymerizable monomer mixture includes those containing only one kind of radical polymerizable monomer.
The polymerization of the radical polymerizable monomer mixture can be performed by a known polymerization method such as a suspension polymerization method or an emulsion polymerization method. In particular, the emulsion polymerization method is preferable from the viewpoint of storage stability of the aqueous coating material, water resistance of the coating film, and various physical properties such as solvent resistance.

For the emulsion polymerization, for example, a known method in which a radical polymerizable monomer mixture is supplied into a polymerization system in the presence of a surfactant and polymerization is performed with a radical polymerization initiator can be employed.
The polymerization of the radical polymerizable monomer mixture may be one-stage polymerization or two-stage or more multi-stage polymerization.
Here, “multi-stage polymerization” refers to polymerization of the radical monomer mixture in the urethane resin (A), and then adding the radical polymerizable monomer mixture to the polymerization system in several steps. Means to do.

The method for supplying the radical polymerizable monomer mixture into the polymerization system is not particularly limited as long as it has the effect of the present invention, and a method for dropping the radical polymerizable monomer mixture into the polymerization system; a surfactant and A method of preparing a pre-emulsion solution in which a radical polymerizable monomer mixture is pre-emulsified and dispersed using water and dropping this pre-emulsion solution into the polymerization system; polymerizing the radical polymerizable monomer mixture all at once And a method of introducing it into the system.
In the case of producing a polymer dispersion containing polymer particles by one-stage polymerization, it is preferable to employ a technique in which radically polymerizable monomer mixture is charged into a polymerization system all at once. In the case of multistage polymerization of two or more stages, two or more of these techniques may be used in combination. Especially, it is preferable to employ | adopt the method of pouring a radically polymerizable monomer mixture in the 1st step | paragraph collectively, and to employ | adopt the method of dripping a pre-emulsion liquid after the 2nd step | paragraph.
The method in which the first-stage radical polymerizable monomer mixture is charged into the polymerization system all at once and the emulsion polymerization is performed is such that a polymer is uniformly formed inside the urethane resin (A) as compared with the drop polymerization. Since this polymer can be made into a high molecular weight body by batch polymerization, the water resistance and solvent resistance of the coating film are improved. In addition, the second and subsequent stages are preferred because the polymerization stability is improved by emulsion polymerization using a technique of dropping a pre-emulsion solution.

(Polymerization initiator)
As the polymerization initiator used for polymerization of the radical polymerizable monomer mixture, those generally used for radical polymerization can be used, for example, persulfuric acid such as potassium persulfate, sodium persulfate, ammonium persulfate and the like. Salts, azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy) -2,4-dimethylvaleronitrile), oil-soluble azo compounds such as 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile; 2,2′-azobis {2-methyl-N- [1,1 -Bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis {2-methyl-N- [2- (1-hydroxyethyl)] propionamide 2,2′-azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide}, 2,2′-azobis [2- (5-methyl-2-imidazoline-2- Yl) propane] and salts thereof, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] and salts thereof, 2,2′-azobis [2- (3,4,5,6- Tetrahydropyrimidin-2-yl) propane] and salts thereof, 2,2′-azobis (1-imino-1-pyrrolidino-2-methylpropane) and salts thereof, 2,2′-azobis {2- [1- ( 2-hydroxyethyl) -2-imidazolin-2-yl] propane} and salts thereof, 2,2′-azobis (2-methylpropionamidine) and salts thereof, 2,2′-azobis [N- (2-carboxy) ethyl) Water-soluble azo compounds such as 2-methylpropionamidine] and salts thereof; benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxy Organic peroxides such as isobutyrate can be mentioned.
These initiators may be used alone or in combination of two or more.

The addition amount of the radical polymerization initiator used in the first step is 0.001 to 10 parts by mass with respect to 100 parts by mass of the total mass of the radical polymerizable monomer mixture provided in the first step. Is preferred. Taking into consideration the progress of polymerization and control of the reaction, it is more preferably 0.005 to 10 parts by mass. Moreover, it is still more preferable that it is 0.005-1 mass part from a viewpoint of the water resistance, solvent resistance, and a weather resistance improvement by high molecular weight increase of the polymer particle finally obtained. Further, from the viewpoint of reducing the coarse particle ratio of the finally obtained polymer dispersion, it is more preferably 0.005 to 0.5 parts by mass, still more preferably 0.005 to 0.2 parts by mass, particularly preferably. Is 0.005 to 0.09 parts by mass.
Here, the “rough particle ratio” means that the polymer is coalesced during the polymerization and the average particle diameter is in the form of particles exceeding 1 μm. For example, the measurement of the particle diameter or after the polymerization Evaluation can be made by measuring the weight of the particulate polymer remaining on the mesh after filtration through a mesh or the like.
The amount of the radical polymerization initiator used in the first step is the polymerization used in all steps of the polymerization when the polymer dispersion containing the polymer particles of the present invention is produced in one step. It means the amount of initiator, and when it is produced by multistage polymerization of two or more stages, it means the amount of polymerization initiator used in the first stage process.

The addition amount of the radical polymerization initiator used in the steps after the second stage is 0.01 to 10 parts by mass with respect to 100 parts by mass of the total mass of the radical polymerizable monomer mixture provided for each stage. Is preferred. Among these, it is more preferable that the amount is 0.02 to 5 parts by mass in consideration of polymerization progress and reaction control.
In the polymerization, it is preferable to use a reducing agent such as sodium bisulfite, ferrous sulfate, ascorbate or Rongalite in combination with the above radical polymerization initiator.
Of these, organic peroxides such as t-butyl hydroperoxide from the viewpoint of progress of polymerization, wettability with respect to the substrate when coating an aqueous coating material, water resistance, weather resistance, and solvent resistance of the coating film More preferably, a combination of ferrous sulfate and ascorbate is employed.

(emulsifier)
In the present invention, an emulsifier can be used as necessary. When an emulsifier is used, the polymerization stability during emulsion polymerization can be improved, and aggregates can be reduced. In this case, the obtained polymer dispersion contains an emulsifier.
In general, the content of the emulsifier is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 100 parts by mass of the total mass of the radical polymerizable monomer mixture supplied to each stage. -5 parts by mass, more preferably 0.5-2 parts by mass.
As the emulsifier, the following anionic, cationic and nonionic surfactants and reactive surfactants can be used.

  Anionic surfactants include potassium oleate, sodium laurate, sodium dodecylbenzene sulfonate, sodium alkane sulfonate, sodium alkyl naphthalene sulfonate, sodium dialkyl sulfosuccinate, polyoxyethylene alkyl ether sodium sulfate, polyoxyethylene alkyl Non-reactive surfactants such as sodium allyl ether sulfate, polyoxyethylene alkyl phosphate ester, polyoxyethylene alkyl allyl phosphate ester, and alkyl allyl sulfosuccinate (eg, Sanyo Kasei Co., Ltd .: Eleminol (registered trademark) JS-) 2, JS-20, manufactured by Kao Corporation: LATEMUL (registered trademark) S-180A, S-180, etc.), polyoxyethylene alkylpropenyl phenyl ether Ammonium sulfate ammonium salt (for example, Aqualon (registered trademark) HS-10, HS-5, BC-10, BC-5 and the like manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), α-sulfo-ω- (1 -(Nonylphenoxy) methyl-2- (2-propenyloxy) ethoxy) -poly (oxy-1,2-ethanediyl) ammonium salt (for example, manufactured by Asahi Denka Kogyo Co., Ltd .: Adecalia Soap (registered trademark) SE-) 10, SE-1025A, and the like), polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate ammonium salt (for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Aqualon (registered trademark) KH-10) Α-sulfo-ω- (1- (alkoxy) methyl-2- (2-propenyloxy) ethoxy) -poly (oxy-1,2-ethanedi) Yl) ammonium salt (for example, manufactured by Asahi Denka Kogyo Co., Ltd .: Adecalia Soap (registered trademark) SR-10, SR-1025 etc.), polyoxyalkylene alkenyl ether ammonium sulfate salt (for example, manufactured by Kao Corporation) Reactive surfactants such as LATEMUL (registered trademark) PD-104).

  Examples of the cationic surfactant include non-reactive surfactants such as stearylamine hydrochloride, lauryltrimethylammonium chloride, and trimethyloctadecylammonium chloride.

  Nonionic surfactants include non-reactive surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethyleneoxypropyl block polymer, polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, α- Hydro-ω- (1-alkoxymethyl-2- (2-propenyloxy) ethoxy) -poly (oxy-1,2-ethanediyl)) (Asahi Denka Kogyo Co., Ltd .: Adeka Soap ER-10, ER- 20, ER-30, ER-40), polyoxyethylene alkyl propenyl phenyl ether (Daiichi Kogyo Seiyaku Co., Ltd .: Aqualon RN-20, RN-30, RN-50), polyoxyalkyl alkenyl ether (Kao ( Co., Ltd .: Laterum PD-420, PD -430, PD-450) and the like.

Moreover, an amphoteric surfactant can also be used as an amphoteric component.
These emulsifiers can be used alone or in combination of two or more.

(Basic compound)
In the method for producing a polymer dispersion of the present invention, it is preferable to adjust the pH to about 6.0 to 11.0 by adding a basic compound after polymerization. This is preferable because the stability of the polymer dispersion and the storage stability of the aqueous coating material are improved.
Examples of such basic compounds include ammonia, triethylamine, propylamine, dibutylamine, amylamine, 1-aminooctane, 2-dimethylaminoethanol, ethylaminoethanol, 2-diethylaminoethanol, 1-amino-2-propanol. 2-amino-1-propanol, 2-amino-2-methyl-1-propanol, 3-amino-1-propanol, 1-dimethylamino-2-propanol, 3-dimethylamino-1-propanol, 2-propyl Examples include aminoethanol, ethoxypropylamine, aminobenzyl alcohol, morpholine, sodium hydroxide, and potassium hydroxide. Among these, from the viewpoint of the stability of the polymer dispersion, amine-based compounds are preferable, and 2-dimethylaminoethanol is preferably used.

<Water-based coating material>
The aqueous coating material of the present invention preferably contains the aforementioned polymer particles and a dispersion medium. The aqueous coating material preferably further contains a polyolefin polymer.

[Polyolefin polymer]
Since the polymer particles of the present invention are excellent in compatibility with the polyolefin polymer, the coating film obtained from the aqueous coating material containing the polymer particles and the polyolefin polymer is particularly excellent in adhesion to the polyolefin substrate. .
The polyolefin polymer refers to a polymer containing olefin as a main monomer raw material, and refers to an olefin polymer such as an olefin homopolymer or copolymer.
Examples of the olefin polymer include an olefin polymer having no reactive group and a modified olefin polymer having a reactive group.
Preferable embodiments of the polyolefin polymer include, for example, propylene polymers that satisfy the following (1) to (3).
(1) A polyolefin polymer having a propylene content of 50 mol% or more, more preferably 60 mol% or more, and most preferably 70 mol% or more.
(2) A polyolefin polymer having a molecular weight distribution [Mw / Mn] of 4.0 or less, more preferably 3.0 or less.
(3) Melting point [Tm] is 125 ° C. or lower, more preferably 100 ° C. or lower, more preferably 9
A polyolefin polymer having a temperature of 0 ° C. or lower.
As the polyolefin polymer, a commercially available polyolefin polymer can be used as it is. Specifically, Mitsubishi Chemical Corporation: APTPLOK series BW-5550, Toyobo Co., Ltd .: HARDLEN series EH-801, EW-5303, EW-5504, EW-5515, EW-8511, EZ-1000, EZ-2000, Nippon Paper Industries Co., Ltd. product: Super Clone series E-480T, E-415, E-412T, S-6375, S-6377, etc. are mentioned.
The content of the polyolefin polymer in the aqueous coating material is selected from the viewpoints of storage stability of the aqueous coating material, adhesion of the coating film to the substrate, particularly adhesion to the polyolefin substrate, water resistance, and solvent resistance. The blending amount of the polyolefin polymer is preferably 5 to 2000 parts by mass with respect to 100 parts by mass of the particles, more preferably 10 to 200 parts by mass, still more preferably 15 to 100 parts by mass, and 25 to 70 parts by mass. Part is particularly preferred.

[Dispersion medium]
The dispersion medium contained in the aqueous coating material is preferably water or a solvent.
As the solvent, those usually used for water-based paints can be used. Examples of such a solvent include linear, branched or cyclic aliphatic alcohols having 5 to 14 carbon atoms; alcohols containing an aromatic group; general formula HO— (CH ₂ CHXO) _p — Represented by 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). ) ethylene glycol or (poly) monoethers and propylene glycol; general formula ^{_{R 5 COO- (CH 2 CHXO)}} q -R 6 (R 5, R 6 is a straight-chain or branched having 1 to 10 carbon atoms X is a hydrogen atom or a methyl group, and q is an integer of 5 or less.) (Poly) ethylene glycol ether ester or (poly) propylene glycol ether Steal; aromatic organic solvents such as toluene and xylene; mono- or diisobutyrate of 2,2,4-trimethyl-1,3-pentanediol, 3-methoxybutanol, 3-methoxybutanol acetate, 3-methyl- Examples include 3-methoxybutanol and 3-methyl-3-methoxybutanol acetate.
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 1-octanol, 2-octanol, 2- At least selected from the group consisting of 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, dipropylene glycol mono n-butyl ether One alcohol solvent is particularly preferred.

The aqueous coating material of the present invention preferably further contains various additives.
Examples of additives include various pigments, resin beads, antifoaming agents, pigment dispersants, leveling agents, anti-sagging agents, curing catalysts, matting agents, ultraviolet absorbers, light stabilizers, antioxidants, and heat resistance. Various additives such as an improver, a slip agent, a preservative, a plasticizer, a thickener, a wetting agent, and a solvent can be used, and one or more of these can be used.
In addition, other polymer particles (for example, polyester resins, polyurethane resins, acrylic resins, acrylic silicone resins, silicone resins, fluorine resins, epoxy resins, polyolefin resins, alkyd resins) may be used for aqueous coating materials. Dispersed particles composed of other polymers, etc.), water-soluble resin / viscosity control agent, amino resin, polyisocyanate compound, blocked polyisocyanate compound, melamine resin, urea resin, carboxyl group-containing compound, carboxyl group-containing resin, epoxy A curing agent such as a group-containing resin, an epoxy group-containing compound, or a carbodiimide group-containing compound may be mixed.

Examples of the pigment include a color pigment, an extender pigment, and a glitter pigment.
Examples of coloring pigments include titanium oxide, zinc oxide, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, selenium pigments, and perylene pigments. Is mentioned.
Examples of extender pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica, and alumina white.
Examples of bright 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 flake, hologram And pigments.
One or more of these can be used.

The concentration of the polymer particles in the aqueous coating material is preferably 1 to 80% by mass, and more preferably 2 to 70% by mass. If it is this range, it is excellent in a coating-material viscosity characteristic, the water resistance of a coating film, and solvent resistance.
Further, when the aqueous coating material contains other polymer particles other than the polymer particles of the present invention, it is 5000 parts by mass or less with respect to 100 parts by mass of the polymer particles. It is preferable in terms of water resistance and solvent resistance.

[Method for preparing aqueous coating material]
The aqueous coating material of the present invention stirs and mixes a dispersion containing the polymer particles of the present invention (which may be the polymer dispersion described above), preferably an olefin polymer, and the various additives described above. Can be prepared.

<Painted object>
The coated product of the present invention is a coated product having a coating film to which an aqueous coating material containing the polymer particles of the present invention is applied.
There are no particular restrictions on the location where the aqueous coating material is applied to form the coating film, and various articles (hereinafter referred to as “base material” for convenience) can be formed into a coated product.
Examples of the base material include an outer plate part of an automobile body, an automobile interior base material, an outer plate part of a household electrical product, a cement mortar, a slate plate, a gypsum board, an extruded plate, an expandable concrete, a metal, glass, and a porcelain tile. , Asphalt, wood, waterproof rubber material, plastic, calcium silicate base material, PVC sheet, FRP (Fiber Reinforced Plastics), natural leather, synthetic leather, fiber and the like.
Specific examples of the coated material having a coating film obtained by applying the aqueous coating material of the present invention include, for example, interior / exterior of passenger cars / trucks / motorcycles / buses, building materials, interior / exterior of buildings, window frames, window glass, Structural members, plate materials, exteriors of machinery and equipment, bridges, guard rails, tents, greenhouses, blinds, roofing materials, housing equipment, refrigerators, air conditioners, televisions, lighting fixtures, kitchen utensils, functional fibers, and the like.

(Preparation method of coating film)
Examples of methods for applying the aqueous coating material to the surface of various substrates include air spray coating, airless spray coating, rotary atomization coating, curtain coat coating, roller coat coating, bar coat coating, air knife coating, and brush coating. Various coating methods such as dipping coating can be selected as appropriate.
The coating amount of the aqueous coating material is the thickness after drying of the coating film obtained by applying the aqueous coating material, and is usually preferably about 0.1 to 100 μm, more preferably 1 to 50 μm, An amount of 10 to 40 μm is particularly preferable.

  Moreover, it is preferable that the drying temperature after application | coating is normal temperature drying (5-35 degreeC), or the range exceeding 35 degreeC and 200 degrees C or less, ie, 5-200 degreeC. In particular, the aqueous coating material of the present invention provides a coating film having excellent adhesion, water resistance and solvent resistance even under low temperature drying conditions, so that it can be dried at room temperature (5-35 ° C.) or low temperature drying from the viewpoint of energy saving. Adopting (over 35 ° C. and 100 ° C. or less), that is, drying at 5 to 100 ° C. is preferable, drying at 5 to 80 ° C. is more preferable, and drying at 5 to 70 ° C. is more preferable. The drying time is preferably about 30 minutes, for example. According to the aqueous coating material of the present invention, a coating film having excellent adhesion, water resistance and solvent resistance can be obtained even under conditions where water and solvent evaporation and particle fusion are insufficient.

Moreover, you may implement the drying after application | coating in two or more processes. For example, after performing a preliminary process such as preheating or air blowing, this process may be performed using a drying furnace such as a hot air furnace, an electric furnace, or an infrared induction heating furnace at a higher temperature than the preliminary process. When preheating is performed, the time is preferably about 30 seconds to 15 minutes, more preferably 1 to 10 minutes, and further preferably 2 to 5 minutes. The temperature and time of this step can be appropriately selected from the above preferable range and the like.
As described above, according to the present invention, a polymer dispersion excellent in polymerization stability and excellent in coating viscosity characteristics and storage stability when used in an aqueous coating material, and contained in the polymer dispersion Polymer particles can be provided. According to the present invention, there are provided an aqueous coating material capable of obtaining a coating film excellent in adhesion, water resistance, solvent resistance, and soft feel to various substrates, and a coated product coated with the aqueous coating material. it can.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated in detail, this invention is not limited to these Examples.
Unless otherwise specified, “part” in this example means “part by mass”, and “%” means “mass%”. Moreover, the measurement, evaluation, etc. about the polymer dispersion liquid and the aqueous coating material in this example were performed by the methods shown below.
In addition, Tables 1 to 3 show the number of blended parts of each component and the evaluation results when the polymer dispersion was produced in each example.

[Coating adhesion evaluation]
(Preparation of test specimen for evaluation)
The aqueous coating material obtained in each example was applied to a polyolefin substrate (TSOP-5) in a 20 ° C. atmosphere using a bar coater so that the dry film thickness was 20 μm, and the drying conditions (70 ° C., The test piece for evaluation of adhesion was dried for 30 minutes).
(Evaluation of adhesion)
Make 11 cuts at 1mm vertical and horizontal intervals to reach the base material on the coating surface of the test piece, make 100 grids, and apply cellophane adhesive tape on it, and then apply this adhesive tape rapidly. And the state of the coating film was observed. The same peeling operation with an adhesive tape was performed from four different directions with respect to the coating film surface, the number of peeling masses of the subsequent grids was observed, and the substrate adhesion was determined according to the following criteria.
◎: The number of peeled squares is 0: ○: The number of peeled squares is 0 to 10 △: The number of peeled squares is 11 to 30 ×: The number of peeled squares is 31 or more

[Water resistance evaluation of coating film]
(Preparation of test plate for evaluation)
Using a bar coater with the aqueous coating material obtained in each example on a black acrylic plate (TP Giken, plate thickness 2 mm, length 150 mm × width 70 mm) at 20 ° C., the dry film thickness becomes 20 μm. A test plate for evaluation of water resistance was prepared by coating the film and drying it under drying conditions (70 ° C., 30 minutes).
(Evaluation of water resistance)
The test plate for evaluation was taken out after being immersed in warm water at 50 ° C. for 24 hours, and the retention rate (gloss retention rate) and ΔL immediately after 60 ° gloss were used as an index of water resistance.
The 60% gloss retention rate (%) means that the 60 ° gloss of the pre-test coating film is “G1”, taken out after being immersed in 50 ° C. warm water for 1 day, and the 60 ° gloss of the coating film immediately after is taken as “ “G2” is a value represented by “(G2 / G1) × 100”. The 60 ° gloss was measured with PG-1M manufactured by Nippon Denshoku Industries Co., Ltd.
ΔL is a value obtained by subtracting “L value of coating film before test” from “L value of coating film immediately after being immersed in warm water at 50 ° C. for 1 day”. The L value is an index of “brightness (whiteness)” and was measured with a CR-300 manufactured by MINOLTA.

[Tactile (soft feel) test]
The tactile sensation was judged by finger touch on the coating film surface of the test piece for adhesion evaluation.
○: A soft feeling is felt on the surface of the coating film.
Δ: Somewhat soft feeling.
X: Soft feeling is not felt.

[Example 1] (One-stage polymerization)
(Preparation of polymer dispersion)
In a flask equipped with a stirrer, a reflux condenser, a temperature control device, and a dripping pump, a polyester urethane resin (trade name: Implanil DLP-R, manufactured by Sumika Bayer Urethane Co., Ltd., solid) as a urethane resin (A) 50%): 60 parts (30 parts as solid content), deionized water: 154 parts, Neocor SWC (anionic surfactant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 70%): 0.13 parts (Solid content: 0.09 part) As a radical polymerizable monomer, 46.5 parts of i-butyl methacrylate and 23.5 parts of n-butyl acrylate were charged, and the flask was heated to 50 ° C. Thereafter, as a polymerization initiator, a 70% aqueous solution of t-butyl hydroperoxide (trade name; Kayabutyl H70, manufactured by Kayaku Akzo Co., Ltd.): 0.014 parts (0.0098 parts as a pure component) and a reducing agent As follows: Ferrous sulfate: 0.00014 parts, ethylenediaminetetraacetic acid (EDTA): 0.00019 parts, sodium ascorbate: 0.014 parts, deionized water: 0.7 parts. Further, after confirming the peak top temperature due to the polymerization exotherm, the internal temperature of the flask was raised to 60 ° C. and held for 1.5 hours. Then, the reaction liquid was cooled to room temperature, and the dispersion liquid (polymer dispersion liquid) containing the polymer particles of the present invention was obtained.

(Preparation of aqueous coating material)
Polyolefin polymer dispersion (trade name: Supercron E-480T, Nippon Paper Industries Co., Ltd., solid content 30%): 100 parts (solid content) to 200 parts (70 parts as solid content) of the obtained polymer dispersion 30 parts), and stirring with a disper, 20 parts of a solvent (diethylene glycol mono n-butyl ether), 7 parts of a wetting agent (trade name: KL-245), and 20 parts of deionized water are added, An aqueous coating was prepared.
The obtained aqueous coating material was applied to a test plate for evaluation as described above to produce a coating film, and evaluated for adhesion, water resistance, and soft feel. The evaluation results are shown in Table 1.

[Examples 2 and 3]
As shown in Table 1, each component was changed, and a reaction solution was prepared in the same manner as in Example 1. After cooling the reaction solution to room temperature, 25% ammonia water in Example 2 was used as a neutralizing agent: 0.79 parts and deionized water: 1.4 parts, and in Example 3, 25% ammonia water: 2.42 parts and deionized water: 1.4 parts were added, and the polymer dispersion was added. An aqueous coating was prepared. The obtained aqueous coating material was evaluated in the same manner as in Example 1, and the evaluation results are shown in Table 1.

[Examples 5 to 8]
As shown in Table 1, the surfactant, the polymerization initiator, and the reducing agent used in Example 1 were changed in each component of the urethane resin (A), the monomer (b1), and the monomer (b2). A polymer dispersion and an aqueous coating material were prepared in the same manner as in Example 1 except that the amount of deionized water was changed as follows. The obtained aqueous coating material was evaluated in the same manner as in Example 1, and the evaluation results are shown in Table 1.
[Example 5]
DLP-R: 40 parts (20 parts as solid content)
Deionized water: 164 parts Neocor SWC: 0.15 parts (solid content 0.105 parts)
Kayabutyl H70: 0.016 part (0.0112 as a pure component)
Ferrous sulfate: 0.00016 parts EDTA: 0.00022 parts Sodium ascorbate: 0.016 parts Deionized water: 0.8 parts

[Example 6]
DLP-R: 92 parts (46 parts as solid content)
Deionized water: 138 parts Neocoal SWC: 0.1 parts (solid content 0.07 parts)
Kayabutyl H70: 0.0108 parts (0.00756 parts as a pure component)
Ferrous sulfate: 0.000108 parts EDTA: 0.00015 parts Sodium ascorbate: 0.0108 parts Deionized water: 0.54 parts

[Example 7]
DLP-R: 140 parts (70 parts as solid content)
Deionized water: 114 parts Neocor SWC: 0.06 parts (solid content 0.042 parts)
Kayabutyl H70: 0.006 part (0.00042 part as pure part)
Ferrous sulfate: 0.00006 part EDTA: 0.00008 part Sodium ascorbate: 0.006 part Deionized water: 0.3 part

[Example 8]
DLP-R: 160 parts (80 parts as solid content)
Deionized water: 104 parts Neocol SWC: 0.04 parts (solid content 0.028 parts)
Kayabutyl H70: 0.004 part (0.0028 part as pure part)
Ferrous sulfate: 0.00004 parts EDTA: 0.00005 parts Sodium ascorbate: 0.004 parts Deionized water: 0.2 parts

[Examples 4 and 9 to 14]
A polymer dispersion and an aqueous coating material were prepared in the same manner as in Example 1, except that each component was changed as shown in Tables 1 and 2. In Example 4, as the urethane resin (A), UH650: polyester urethane resin having a sulfonic acid group (trade name: Implanil UH650, manufactured by Sumika Bayer Urethane Co., Ltd., solid content 50%) was used.
The obtained aqueous coating material was evaluated in the same manner as in Example 1, and the evaluation results are shown in Tables 1 and 2.

Example 15 (two-stage polymerization)
(Preparation of polymer dispersion)
(1) First stage polymerization process (radical polymerizable monomer mixture is charged all at once)
In a flask equipped with a stirrer, a reflux condenser, a temperature control device, and a dripping pump, a polyester urethane resin (trade name: Implanil DLP-R, manufactured by Sumika Bayer Urethane Co., Ltd., solid) as a urethane resin (A) 50%): 60 parts (30 parts as solid content), deionized water: 113.4 parts, Neocor SWC (anionic surfactant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 70%): 0. 13 parts (solid content: 0.091 part), as radical polymerizable monomers, 23.5 parts of i-butyl methacrylate and 11.5 parts of n-butyl acrylate were charged, and the flask was heated to 50 ° C. Thereafter, as a polymerization initiator, a 70% aqueous solution of t-butyl hydroperoxide (trade name; Kayabutyl H70, manufactured by Kayaku Akzo Co., Ltd.): 0.014 parts (0.0098 parts as a pure component) and a reducing agent As follows: Ferrous sulfate: 0.00014 parts, ethylenediaminetetraacetic acid (EDTA): 0.00019 parts, sodium ascorbate: 0.014 parts, deionized water: 0.7 parts. Further, after confirming the peak top temperature due to the polymerization exotherm, the internal temperature of the flask was raised to 75 ° C. and held for 20 minutes.
(2) Second stage polymerization step (pre-emulsion solution added dropwise)
Next, as a reducing agent, sodium ascorbate: 0.07 part, deionized water: 3.5 parts were added to the dispersion obtained in (1) above, and the mixture was kept at 75 ° C. for 10 minutes. -Butyl methacrylate: 23.5 parts, n-butyl acrylate: 11.5 parts, Neocor SW-C: 0.56 parts (solid content 0.392 parts), Adekaria soap ER-10 (nonionic surfactant, (Made by ADEKA Co., Ltd.): 0.56 parts, deionized water: pre-emulsified dispersion containing 21 parts in advance, and a 70% aqueous solution of t-butyl hydroperoxide (trade name; Kayabutyl H70, Kayaku Akzo ( Co., Ltd.): A polymerization initiator aqueous solution containing 0.021 parts (0.0147 parts as a pure component) and deionized water: 17.5 parts was added dropwise over 1 hour. During the dropwise addition, the internal temperature of the flask was maintained at 75 ° C., and was maintained at 75 ° C. for 1.5 hours after the completion of the dropwise addition. Then, the reaction liquid was cooled to room temperature, and the dispersion liquid (polymer dispersion liquid) containing the polymer particles of the present invention was obtained.
The aqueous coating material was prepared in the same manner as in Example 1. And evaluation similar to Example 1 was performed. The evaluation results are shown in Table 2.

[Examples 16 to 19]
A polymer dispersion and an aqueous coating material were prepared in the same manner as in Example 15 except that each component was changed as shown in Table 2. And evaluation similar to Example 1 was performed. The evaluation results are shown in Table 2.

[Comparative Examples 1-3]
A polymer dispersion and an aqueous coating material were prepared in the same manner as in Example 1 except that each component was changed as shown in Table 3. And evaluation similar to Example 1 was performed. The evaluation results are shown in Table 3.

However, the symbol in a table | surface shows the following compounds.
[Urethane resin (A)]
DLP-R: Polyester urethane resin having a sulfonic acid group (trade name: Implanil DLP-R, manufactured by Sumika Bayer Urethane Co., Ltd., solid content 50%)
UH650: Polyester urethane resin having a sulfonic acid group (trade name: Implanil UH650, manufactured by Sumika Bayer Urethane Co., Ltd., solid content 50%)
[Radically polymerizable monomer]
TBMA: t-butyl methacrylate (SP value: 18.32)
MMA: Methyl methacrylate (SP value: 20.15)
IBMA: i-butyl methacrylate (SP value: 18.82)
NBMA: n-butyl methacrylate (SP value: 19.12)
IBA: i-butyl acrylate (SP value: 19.40)
NBA: n-butyl acrylate (SP value: 19.73)
AA: acrylic acid (SP value: 25.70)

As shown in Tables 1 and 2, the coating film obtained from the aqueous coating material containing the dispersion containing the polymer particles of Examples 1 to 19 was excellent in adhesion, water resistance, and soft feel.
On the other hand, as shown in Table 3, a methacrylic acid ester monomer (b2) having a solubility parameter (SP _m ) of 20.1 (J / cm ³ ) ^1/2 or less was converted into a radical polymerizable monomer. The comparative example 1 which does not contain 50 wt% with respect to the total amount of a body (b) was inferior in adhesiveness. Further, Comparative Example 2 and Comparative Example 3 where the glass transition temperature (Tg) of the polymer (B) was not in the range of −5 to 45 ° C. were poor in adhesion.

  The polymer dispersion containing the polymer particles of the present invention and the aqueous coating material can form a coating film excellent in adhesion, water resistance, and soft feel to various substrates, particularly polyolefin substrates. Moreover, the obtained coating film is excellent in adhesiveness and water resistance even under low temperature drying conditions. Therefore, the water-based coating material according to the present invention is used for various purposes including protection of the body of automobile car bodies such as passenger cars, trucks, motorcycles, buses, etc., automobile parts, buildings, civil engineering structures, etc. Can be used for various coating applications, and is extremely useful industrially.

Claims (8)

Polymer particles containing urethane resin (A) and polymer (B) containing a monomer unit derived from radical polymerizable monomer (b) in the same particle,
The radical polymerizable monomer (b) is an acrylate monomer (b1), and methacrylic acid having a solubility parameter calculated by the Fedors method of 20.1 (J / cm ³ ) ^1/2 or less. 1 to 1 or more types selected from the group consisting of ester monomers (b2) is contained in an amount of 50 to 100% by mass based on the total amount of the radical polymerizable monomers (b),
The polymer particle whose glass transition temperature (Tg) computed by the following formula | equation (1) of the said polymer (B) is -35-57 degreeC.
Tg = 1 / (W ₁ / Tg ₁ + W ₂ / Tg ₂ +... + W _n / Tg _n ) (1)
In (Equation (1), Tg represents the glass transition temperature of the polymer _{(B), Tg 1, Tg} 2 ··· Tg n is the glass of the radically polymerizable monomers constituting the polymer (B) Represents transition temperature, W ₁ , W ₂ ... W _n represent mass fractions of each radical polymerizable monomer.) The polymer particle of Claim 1 whose solubility parameter computed by the following formula | equation (2) of the said polymer (B) is 19.7 (J / cm < ³ >) < ^1/2 > or less.
_{SP p = 1 / (W 1} / SP m1 + W 2 / SP m2 + ··· + W n / SP mn) ··· (2)
(In Formula (2), SP _p represents the solubility parameter of the polymer (B), and SP _m1 , SP _m2 ... SP _mn represents the respective radical polymerizable monomers constituting the polymer (B). The solubility parameter calculated by the Fedors method is represented, and W ₁ , W ₂ ... W _n represent the mass fraction of each radical polymerizable monomer.)   The polymer particle of Claim 1 or 2 whose glass transition temperature (Tg) computed by the said Formula (1) of the said polymer (B) is -5-45 degreeC. The radical polymerizable monomer (b) contains at least the methacrylic acid ester monomer (b2),
The methacrylic acid ester monomer (b2) contains at least one methacrylic acid ester selected from the group consisting of t-butyl methacrylate, i-butyl methacrylate and n-butyl methacrylate. The polymer particles according to Item.   The polymer dispersion liquid containing the polymer particle as described in any one of Claims 1-4.   The aqueous coating material containing the polymer particle and dispersion medium as described in any one of Claims 1-4.   The aqueous coating material according to claim 6, further comprising a polyolefin polymer.   A coated product to which the aqueous coating material according to claim 6 is applied.