JP2021152089A - Powdered coating material, production method for the same, production method for base material having coating film, and coated article - Google Patents

Abstract

To provide a powdered coating material, a production method for the powdered coating material, a production method for a base material having a coating film, and a coated article, with which it is possible to form a coating film having excellent abrasion resistance even if the coating film is formed by heat treatment at a low temperature.SOLUTION: This powdered coating material contains a non-fluorine resin, a curing agent, and a fluorine-containing polymer which contains a unit based on fluoroolefin, a unit based on a monomer represented by formula X-Z, and a unit based on a monomer represented by the formula CHR21=CR22R23COOH.SELECTED DRAWING: None

Description

The present invention relates to a powder coating material, a method for producing a powder coating material, a method for producing a base material with a coating film, and a coated article.

In recent years, in the paint field, it has been required to suppress the emission of volatile organic compounds (VOCs) such as organic solvents into the atmosphere from the viewpoint of environmental load. Therefore, from the viewpoint of VOC removal, powder coating materials containing no organic solvent are attracting attention. Powder coatings do not require exhaust treatment or wastewater treatment during painting, and can be collected and reused, so the environmental load is low.
Patent Document 1 describes a layer containing a fluorine polymer using a powder coating material containing a fluorine-containing polymer having a hydroxy group or a carboxy group, a polyester resin having a hydroxy group or a carboxy group, and a curing agent. , It is described that a coating film having a layer containing a polyester resin can be formed. It is stated that the powder coating material has good weather resistance and can reduce the manufacturing cost.

International Publication No. 2013/186832

On the other hand, in the production of powder coating materials containing a fluorine-containing polymer, further energy saving is required, and in particular, it is required to lower the heat treatment temperature at the time of forming a coating film.
The present inventors have found that when forming a coating film from the powder coating material described in Patent Document 1, the abrasion resistance of the coating film when the heat treatment temperature is low is not sufficient. Specifically, the coating film formed by using the powder coating material described in Patent Document 1 at a heat treatment temperature of 170 ° C. is located at a predetermined height as compared with the coating film formed at a heat treatment temperature of 190 ° C. It was found that the amount of reduction of the coating film when a certain amount of sand was dropped was large.

The present invention has been made in view of the above problems, and is a method for producing a powder coating film or a powder coating film capable of forming a coating film having excellent wear resistance even when a coating film is formed by heat treatment at a low temperature. , A method for producing a base material with a coating film, and an object of providing a coated article.

As a result of diligent studies on the above problems, the inventors have obtained a desired effect by using a powder coating material containing a fluorine-containing polymer containing a unit based on a specific monomer, a non-fluororesin, and a curing agent. It was found that it could be obtained, and the present invention was reached.

That is, the inventors have found that the above problem can be solved by the following configuration.
[1] A fluoropolymer containing a unit based on a fluoroolefin, a unit based on a monomer represented by the formula (1) described later, and a unit based on a monomer represented by the formula (2) described later, and a fluoropolymer. A powder coating material containing a non-fluororesin and a curing agent.
[2] The powder coating material according to [1], wherein the fluorine-containing polymer has an acid value of 5 mgKOH / g or more.
[3] The non-fluororesin is a resin having a reactive group, and is at least one selected from the group consisting of polyester resin, (meth) acrylic resin, urethane resin, and epoxy resin, [1] or The powder coating according to [2].
[4] The content of the unit based on the fluoroolefin is 20 to 60 mol% with respect to all the units contained in the fluoropolymer, and the content of the unit based on the monomer represented by the formula (1) described later is contained. Described in any of [1] to [3], wherein the amount is 5 to 60 mol%, and the content of the unit based on the monomer represented by the formula (2) described later is 5 to 20 mol%. Powder coating.
[5] The fluorine-containing polymer further contains a unit based on the monomer represented by the formula (3) described later, and the content of the unit is 0 mol with respect to all the units contained in the fluorine-containing polymer described later. The powder coating material according to any one of [1] to [4], which is more than% and 40 mol% or less.
[6] If the fluorinated polymer does not contain a unit based on the monomer represented by the formula (4) described later, or contains the unit, and the fluorinated polymer contains the unit, the fluorinated polymer contains the unit. The powder coating material according to any one of [1] to [5], wherein the content of the unit is more than 0 mol% and less than 5 mol% with respect to all the units contained.
[7] When the fluorinated polymer does not contain a unit based on the monomer represented by the formula (5) described later, or contains the unit, and the fluorinated polymer contains the unit, the fluorinated polymer contains the unit. The powder coating material according to any one of [1] to [6], wherein the content of the unit is more than 0 mol% and less than 8 mol% with respect to all the units contained.
[8] The powder according to any one of [1] to [7], wherein the curing agent is a compound having two or more epoxy groups, carbodiimide groups, oxazoline groups or β-hydroxyalkylamide groups in one molecule. paint.
[9] The powder coating material according to any one of [1] to [8], wherein the content of the fluorine-containing polymer with respect to the content of the non-fluororesin is 0.05 to 20 by mass ratio.
[10] The powder coating material according to any one of [1] to [9], further comprising at least one selected from the group consisting of pigments, plasticizers and matting agents.
[11] The fluoropolymer, the non-fluororesin and the curing agent are melt-kneaded, cooled and pulverized, and composed of powder particles containing the fluoropolymer, the non-fluororesin and the curing agent. A method for producing a powder coating material, which obtains the powder coating material according to any one of [1] to [10].
[12] Powder particles containing the fluoropolymer and the curing agent but not the non-fluororesin,
Powder particles containing the non-fluororesin and the curing agent but not the fluorine-containing polymer,
A method for producing a powder coating material, wherein the powder coating material according to any one of [1] to [10] is obtained.
[13] The powder coating material according to any one of [1] to [10] is applied onto a substrate to form a powder coating layer, and the powder coating layer is heat-treated at 120 to 210 ° C. A method for producing a base material with a coating film, which forms a coating film on the base material.
[14] A coated article having a base material and a coating film formed on the base material by the powder coating material according to any one of [1] to [10].

According to the present invention, a powder coating film capable of forming a coating film having excellent wear resistance even when a coating film is formed by heat treatment at a low temperature, a method for producing a powder coating film, a method for producing a substrate with a coating film, And can provide painted articles.

The meanings of the terms in the present invention are as follows.
The numerical range represented by "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.
"(Meta) acrylate" is a general term for "acrylate" and "methacrylic acid", and "(meth) acrylic" is a general term for "acrylic" and "methacrylic acid".
The "unit" is a general term for an atomic group based on one molecule of the monomer, which is directly formed by polymerizing a monomer, and an atomic group obtained by chemically converting a part of the atomic group. .. The "monomer-based unit" is also simply referred to as "unit" below. The content (mol%) of each unit with respect to all the units contained in the polymer is determined by analyzing the polymer by a nuclear magnetic resonance spectrum (NMR) method.
The "acid value" and "hydroxyl value" are values measured according to the method of JIS K 0070-3 (1992), respectively.
The “glass transition temperature” is the midpoint glass transition temperature measured by the differential scanning calorimetry (DSC) method. The "glass transition temperature" is also referred to as "Tg".
The "softening temperature" is a value measured according to the method of JIS K 7196 (1991).
"Melting viscosity" means the value of the viscosity of a sample at 170 ° C. when the temperature is measured from 130 ° C. to 200 ° C. at a temperature rising rate of 10 ° C./min using a rotary rheometer. ..
The "number average molecular weight" and the "weight average molecular weight" are values measured by gel permeation chromatography using polystyrene as a standard substance. The "number average molecular weight" is also referred to as "Mn", and the "weight average molecular weight" is also referred to as "Mw".
The average particle size of the particles constituting the powder (also referred to as "powder particles") is a known particle size distribution measuring device (manufactured by Symbolec, trade name "Hellos-Rodos" or the like, which uses a laser diffraction method as a measuring principle. ) Is a value obtained by calculating the volume average from the particle size distribution measured using.

The powder coating material of the present invention (hereinafter, also referred to as “the coating material”) is a unit based on a fluoroolefin (hereinafter, also referred to as “unit F”), and a monomer represented by the formula (1) described later (1). Hereinafter, a unit based on "monomer 1" (hereinafter, also referred to as "unit 1") and a monomer represented by the formula (2) described later (hereinafter, also referred to as "monomer 2"). Includes a fluoropolymer containing a unit (hereinafter, also referred to as “unit 2”) based on (hereinafter, also referred to as “specific fluoropolymer”), a non-fluororesin, and a curing agent.

The coating film formed by heating the present coating film (hereinafter, also referred to as “the main coating film”) has excellent wear resistance even when the coating film is formed by heat treatment at a low temperature. The reason for this is not always clear, but it is presumed as follows.
Since the specific fluoropolymer containing unit 1 and unit 2 is excellent in fluidity at the time of melting, it is easily arranged on the outermost surface of the coating film even when used in combination with a non-fluororesin. Further, since the specific fluorine-containing polymer contains the unit 2, the main chain of the polymer and the side chain having a carboxy group are less likely to be cleaved, and the cross-linking between the specific fluorine-containing polymers is strong. Become. As a result, it is considered that the wear resistance on the outermost surface of the coating film is excellent. Further, when used in combination with a non-fluororesin, the flexibility of the coating film is improved and the impact applied to the coating film is absorbed, so that the abrasion resistance of the entire coating film is considered to be improved.
In the present specification, the heat treatment at a low temperature specifically means a heat treatment at 180 ° C. or lower.

A fluoroolefin is an olefin in which one or more hydrogen atoms are substituted with fluorine atoms. In the fluoroolefin, one or more hydrogen atoms which are not substituted with fluorine atoms may be substituted with chlorine atoms.
Specific examples of fluoroolefins include CF ₂ = CF ₂ , CF ₂ = CFCl, CF ₂ = CHF, CH ₂ = CF ₂ , CF ₂ = CFCF ₃ , CF ₂ = CHCF ₃ , CF ₃ CH = CHF, CF ₃ CF = CH _{2 is mentioned, and CF 2} = CF ₂ or CF ₂ = CFCl is preferable from the viewpoint that the weather resistance of the present coating film is more excellent, and alternating polymerizable property with other monomers (particularly monomer 2). _{CF 2} = CFCl is particularly preferable from the viewpoint of polymerization rate.
Two or more kinds of fluoroolefins may be used in combination.
The content of the unit F is preferably 20 to 60 mol%, more preferably 30 to 50 mol%, and 35 to 45 mol% from the viewpoint of better weather resistance with respect to all the units contained in the specific fluorine-containing polymer. Is particularly preferable.

Monomer 1 is a monomer represented by the following formula (1), and is a single amount that mainly contributes to the improvement of Tg of the specific fluorine-containing polymer and forms a unit for improving the blocking resistance of the present coating material. The body.
Equation (1) XZ
The symbols in the formula have the following meanings.
X is CH ₂ = CHC (O) O-, CH ₂ = C (CH ₃ ) C (O) O-, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O-, and from the viewpoint of weather resistance of this coating film, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O− is preferable, and CH ₂ = CHOC (O) − is more preferable. Monomer 1 in which X is CH ₂ = CHO- or CH ₂ = CHOC (O)-, in particular, monomer 1 in which X is CH ₂ = CHOC (O)-is another monomer (particularly simple). It is excellent in alternating polymerizable property with the monomer 2) and the polymerization rate, and has a high effect of randomly presenting the unit 2 in the specific fluorine-containing polymer. Therefore, when the present coating film is formed by cross-linking the specific fluorine-containing polymer, the cross-linking tends to be strong. Furthermore, since the blocking resistance of the present coating material is improved, the present coating material can be uniformly applied, and variations in the film thickness of the main coating film can be suppressed.

Z has the formula -C ^(Z _{1) 3} represented by alkyl groups of 4-8 carbon atoms (provided that three of ^{Z 1} are each independently an alkyl group having 1 to 5 carbon atoms and the three Z ^{The total number of carbon atoms contained in 1} is an integer of 3 to 7), a cycloalkyl group having 6 to 10 carbon atoms, a cycloalkylalkyl group having 6 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a carbon number of carbon atoms. It is an aralkyl group of 7 to 12. ^{As Z, an alkyl group having 4 to 8 carbon atoms represented by the formula −C (Z 1} ) ₃ or a cycloalkyl group having 6 to 10 carbon atoms is preferable from the viewpoint of weather resistance of the present coating film.

The group represented by the formula −C (Z ¹ ) ₃ has a structure having a tertiary carbon atom in which three groups represented by ^{the formula Z 1} are bonded to “C (carbon atom)” specified by this formula. It has a structure in which the above group is directly bonded to the group represented by the formula X. Three Z ¹ is either a methyl group into three both one is a methyl group, that the remaining two are each independently an alkyl group having 2 to 5 carbon atoms preferred. The total number of the remaining two carbon atoms of the group is preferably 6.
The cycloalkyl group having 6 to 10 carbon atoms is preferably a cyclohexyl group.
The cycloalkylalkyl group having 6 to 10 carbon atoms is preferably a cyclohexylmethyl group.
The aralkyl group having 7 to 12 carbon atoms is preferably a benzyl group.
The aryl group having 6 to 10 carbon atoms is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group.
The hydrogen atom of the cycloalkyl group, cycloalkylalkyl group, aryl group or aralkyl group may be substituted with an alkyl group. In this case, the carbon number of the alkyl group as the substituent is not included in the carbon number of the cycloalkyl group or the aryl group.
Further, the monomer 1 may be used in combination of two or more.

Specific examples of the monomer 1 include vinyl ester pivalate, vinyl neononanoic acid ester (manufactured by HEXION, trade name "Beova 9"), vinyl benzoate ester, tert-butyl vinyl ether, and tert-butyl (meth) acrylate. , Benzyl (meth) acrylate, and vinyl ester pivalate or vinyl neononanoic acid ester is preferable from the viewpoint of alternability with other monomers (particularly monomer 2) and polymerization rate.
The content of the unit 1 is preferably 5 to 60 mol%, because the Tg of the specific fluorine-containing polymer can be set in a range suitable for the powder coating material with respect to all the units contained in the specific fluorine-containing polymer. ~ 55 mol% is more preferred, and 30-50 mol% is particularly preferred.

The monomer 2 is a monomer represented by the following formula (2), and is a single amount that forms a unit that mainly contributes to the fluidity of the specific fluorine-containing polymer at the time of melting and the wear resistance of the present coating film. The body.
Equation (2) Equation (2) CHR ²¹ = CR ²² R ²³ COOH
The symbols in the formula have the following meanings.
R ²¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a hydrogen atom or a methyl group is preferable.
R ²² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a hydrogen atom is preferable.
R ²³ represents a single bond, a divalent saturated hydrocarbon group having 1 to 12 carbon atoms, or a divalent linking group having an ethereal oxygen atom, and is carbon because the wear resistance of the present coating film is more excellent. A divalent saturated hydrocarbon group having a number of 6 to 12 is preferable.
The divalent saturated hydrocarbon group may be linear or branched. Further, the divalent saturated hydrocarbon group may have a ring structure or may contain a ring structure. The divalent saturated hydrocarbon group is preferably a divalent saturated hydrocarbon group having 6 to 12 carbon atoms, and is linear or branched with 6 to 12 carbon atoms, because the wear resistance of the present coating film is more excellent. Or an alkylene group containing a cycloalkylene group having 6 to 8 carbon atoms is more preferable, and a linear alkylene group having 6 to 12 carbon atoms is particularly preferable.
Examples of the divalent linking group having an ethereal oxygen atom include a saturated hydrocarbon group having an ethereal oxygen atom, a group having an ethereal oxygen atom and an arylene group, and the like. R ²³² -, a group represented by the formula ^{-O-R 233} - and a group represented by the like. In the ^{formulas, R 232} and ^{R 233} is bonded to -COOH of formula (2).
In the formula, ^R232 is a divalent saturated hydrocarbon group having 1 to 12 carbon atoms, and the details of the divalent saturated hydrocarbon group are as described above. ^R233 is an arylene group or an aralkylene group having 1 to 12 carbon atoms which may have a polycyclic structure, and specific examples thereof include a phenylene group.

^{The monomer 2 has R 21} and R ²² of the formula (2) from the viewpoint that the fluidity of the specific fluorine-containing polymer at the time of melting and the content of the unit 2 in the specific fluorine-containing polymer can be suitably adjusted. A monomer represented by the following formula (21), which is a hydrogen atom and R ²³ is a divalent saturated hydrocarbon group having 6 to 12 carbon atoms (hereinafter, also referred to as “monomer 21”), or R. ^{A monomer represented by the following formula (22) in which 21} is an alkyl group having 1 to 3 carbon ^{atoms, R 22} is a hydrogen atom, and R ²³ is a single bond (hereinafter, also referred to as “monomer 22”. ) Is preferable.
Equation (21) CH ₂ = CHR ²³¹ COOH
Equation (22) CHR ²¹¹ = CHCOOH
The symbols in the formula have the following meanings.
R ²³¹ is a divalent saturated hydrocarbon group having 6 to 12 carbon atoms, and is a linear or branched alkylene group having 6 to 12 carbon atoms or an alkylene containing a cycloalkylene group having 6 to 8 carbon atoms. A group is preferable, and a linear alkylene group having 6 to 12 carbon atoms is particularly preferable.
R ²¹¹ is an alkyl group having 1 to 3 carbon atoms, and a methyl group is preferable.

The monomer 21 does not easily form hydrogen bonds between carboxy groups in the molecule, and tends to improve the fluidity of the specific fluorine-containing polymer at the time of melting. In addition, it is easy to improve the surface smoothness of the present coating film.
The monomer 22 has a structure in which a carboxy group is ^{directly bonded to a polymerizable group (group represented by the formula CHR 211} = CH−), and it is easy to improve the Tg of the specific fluorine-containing polymer. In addition, the monomer 22 has a small molecular weight, and it is easy to efficiently introduce a carboxy group into the specific fluorine-containing polymer with respect to the mass used thereof.

Specific examples of the monomer 2 include 3-butenoic acid, 4-pentenoic acid, 2-hexenoic acid, 3-hexenoic acid, 5-hexenoic acid, 3-heptenoic acid, 6-heptenoic acid, 7-octenoic acid, Examples thereof include 8-nonenoic acid, 9-decenoic acid, 10-undecylene acid, (meth) acrylic acid and crotonic acid, and 10-undecylene acid or crotonic acid is preferable.
Two or more types of monomer 2 may be used in combination. From the viewpoint of further improving the fluidity of the specific fluorine-containing polymer at the time of melting, it is preferable to use only the monomer 21 or to use the monomer 21 and the monomer 22 in combination. , It is preferable to use 0.5 to 3 times the molar amount of the monomer 22 in combination with the monomer 21.

Monomer 2 is a monomer having a polymerizable group represented by ^{the formula CHR 21} = CR ^{22 − and one carboxy group.} The monomer 2 has less steric damage than the monoesters of α, β-unsaturated dicarboxylic acids such as maleic acid and fumaric acid, or α, β-unsaturated dicarboxylic acids, and is a fluoroolefin. Not only is the alternating polymerizable property with the monomer 1 high, but also the positional regularity at the time of polymerization is high. As a result, when the unit 2 is contained in the specific fluorine-containing polymer, since the carboxy group is uniformly present, the cross-linking of the specific fluorine-containing polymer is not biased in the present coating film, and it can be said that the specific fluorine-containing polymer has excellent wear resistance. ..
The content of unit 2 is preferably 5 to 20 mol%, more preferably 5 to 15 mol%, with respect to all the units contained in the specific fluorine-containing polymer, from the viewpoint of more excellent wear resistance of the present coating film. 7 to 15 mol% is particularly preferred.

The specific fluorine-containing polymer is a unit based on the monomer represented by the following formula (3) (hereinafter, also referred to as “monomer 3”) (hereinafter, “monomer 3”) from the viewpoint of the flexibility of the present coating film. It may also include "unit 3"). In this case, the content of the unit 3 is preferably more than 0 mol% and 40 mol% or less with respect to all the units contained in the specific fluorine-containing polymer. The upper limit is preferably 35 mol% from the viewpoint of adjusting the Tg of the specific fluorine-containing polymer.
Equation (3) X ^3- Z ³
The symbols in the formula have the following meanings.
X ³ is CH ₂ = CHC (O) O-, CH ₂ = C (CH ₃ ) C (O) O-, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O-, and from the viewpoint of weather resistance of this coating film, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- Alternatively, CH _{2 = CHCH 2} O− is preferable, and CH ₂ = CHOC (O) − is more preferable. ^{Monomer 3 in} which X 3 is CH ₂ = CHO- or CH ₂ = CHCH ₂ O-, in particular, monomer 3 in which X ³ is CH ₂ = CHOC (O)-is another monomer (particularly). It is excellent in alternating polymerizable property with the monomer 2) and the polymerization rate, and has a high effect of randomly presenting the unit 2 in the specific fluorine-containing polymer. As a result, it is easy to prepare a powder coating film that forms a coating film having better wear resistance.

Z ³ is an alkyl group having 1 to 3 carbon atoms, and a methyl group or an ethyl group is preferable.
Further, the monomer 3 may be used in combination of two or more.
Specific examples of the monomer 3 include ethyl vinyl ether, vinyl acetate, and vinyl propionate, and vinyl acetate is used from the viewpoint of alternating polymerizable property with other monomers (particularly monomer 2) and the polymerization rate. preferable.

The specific fluorine-containing polymer is a unit (hereinafter, also referred to as “monomer 4”) based on the monomer represented by the following formula (4) from the viewpoint of further improving the fluidity at the time of melting (hereinafter, also referred to as “monomer 4”). (Also referred to as "unit 4") is not included, or even if it is contained, the content of unit 4 is preferably more than 0 mol% and less than 5 mol% with respect to all the units contained in the specific fluorine-containing polymer.

Equation (4) X ^4- Q ^4- OH
The symbols in the formula have the following meanings.
X ⁴ is CH ₂ = CHC (O) O-, CH ₂ = C (CH ₃ ) C (O) O-, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O-.
Q ⁴ are an alkylene group having 2 to 20 carbon atoms. Alkylene group Q ⁴ represents may include a ring structure.
Specific examples of the monomer 4 include hydroxyalkyl vinyl ether (2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, etc.), hydroxyalkylallyl ether (hydroxyethylallyl ether, etc.), and (meth) acrylate hydroxyalkyl ester ((). Meta) hydroxyethyl acrylate, etc.) can be mentioned.

The specific fluorine-containing polymer retains the Tg of the specific fluorine-containing polymer and retains the blocking resistance of the present coating material. Therefore, the monomer represented by the following formula (5) (hereinafter, “monomer 5”). The unit based on (hereinafter, also referred to as “unit 5”) is not included, or even if it is contained, the content of unit 5 is 0 with respect to all the units contained in the specific fluorine-containing polymer. It is preferably more than mol% and less than 8 mol%.
Equation (5) X ^5- Z ⁵
The symbols in the formula have the following meanings.
X ⁵ is CH ₂ = CHC (O) O-, CH ₂ = C (CH ₃ ) C (O) O-, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O-.
Z ⁵ is an alkyl group having 4 or more carbon atoms, excluding the alkyl group having 4 to 8 carbon atoms represented by the formula −C (Z ¹ ) _3. Three Z ¹ are each independently an alkyl group having 1 to 5 carbon atoms, the total number of carbon atoms included in the three Z ¹ is an integer of 3-7.
Specific examples of the monomer 5 include nonyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, n-butyl vinyl ether, and neodecanoic acid vinyl ester (manufactured by HEXION, trade name "Beova 10", etc.).

As the specific fluorine-containing polymer, the following polymers are particularly preferable.
The content of unit F, the content of unit 1 and the content of unit 2 are 20 to 60 mol% in this order, respectively, with respect to all the units contained in the polymer, including unit F, unit 1 and unit 2. , 5-60 mol% and 5-20 mol% polymers.
-Composed of unit F, unit 1, unit 2, and unit 3, and the content of unit F, the content of unit 1, the content of unit 2, and the content of unit 3 are the contents of unit F, the content of unit 1, and the content of unit 3 with respect to all the units contained in the polymer. , 20-60 mol%, 5-60 mol%, 5-20 mol% and more than 0 mol% and 40 mol% or less, respectively, in this order.
-Composed of unit F, unit 1 and unit 2, the content of unit F, the content of unit 1 and the content of unit 2 are 20 to 60 mol%, respectively, in this order with respect to all the units contained in the polymer. , 5-60 mol% and 5-20 mol% polymers.

The acid value of the specific fluorine-containing polymer is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, further preferably 25 mgKOH / g or more, and particularly preferably 30 mgKOH / g or more. The upper limit of the acid value is preferably 150 mgKOH / g, more preferably 100 mgKOH / g, further preferably 80 mgKOH / g, and particularly preferably 60 mgKOH / g. When the acid value is 5 mgKOH / g or more, the abrasion resistance of the present coating film and the fluidity at the time of melting of the specific fluorine-containing polymer are excellent. When the acid value is 100 mgKOH / g or less, the thermal stability of the specific fluorine-containing polymer is further improved. That is, the acid value of the specific fluorine-containing polymer is preferably 5 to 150 mgKOH / g, more preferably 10 to 100 mgKOH / g, further preferably 25 to 80 mgKOH / g, and particularly preferably 30 to 60 mgKOH / g.
The specific fluorine-containing polymer may have a hydroxyl value, but it is preferable that the specific fluorine-containing polymer does not have a hydroxyl value from the viewpoint of fluidity at the time of melting. When the specific fluorine-containing polymer has a hydroxyl value, it is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less, and particularly preferably less than 1 mgKOH / g.
The Tg of the specific fluorine-containing polymer is preferably 45 to 120 ° C., more preferably 50 to 100 ° C., and particularly preferably 50 to 80 ° C. from the viewpoint of improving the blocking resistance of the present coating material.
The melt viscosity of the specific fluorine-containing polymer at 170 ° C. (hereinafter, also referred to as “melt viscosity”) is 5 to 100 Pa · s because the specific fluorine-containing polymer is easily arranged on the outermost surface of the coating film. Is preferable, 10 to 95 Pa · s is more preferable, and 20 to 90 Pa · s is particularly preferable.

The melt viscosity is preferably set within the above range by controlling the type and content of the unit contained in the specific fluorine-containing polymer, Mw of the specific fluorine-containing polymer, and the like.
The Mw of the specific fluorine-containing polymer is preferably 15,000 to 75,000, more preferably 25,000 to 60,000. When the Mw of the specific fluorine-containing polymer is 15,000 or more, the impact resistance and abrasion resistance of the present coating film are more excellent. When the Mw of the specific fluorine-containing polymer is 75,000 or less, the fluidity of the specific fluorine-containing polymer at the time of melting and the surface smoothness and flexibility of the present coating film can be provided.
The Mn of the specific fluorine-containing polymer is preferably 5,000 to 25,000, more preferably 6,000 to 120,000, and particularly preferably 7,000 to 15,000. When the Mn of the specific fluorine-containing polymer is 5,000 or more, the impact resistance and abrasion resistance of the present coating film are more excellent. When the Mn of the specific fluorine-containing polymer is 25,000 or less, the fluidity of the specific fluorine-containing polymer at the time of melting and the surface smoothness and flexibility of the present coating film can be provided.
Mw and Mn of the specific fluorine-containing polymer can be set within the above range by adopting a solution polymerization method as a method for producing the specific fluorine-containing polymer or appropriately selecting a polymerization solvent.

The content of the specific fluorine-containing polymer is preferably 10 to 90% by mass, particularly preferably 10 to 70% by mass, based on the total mass of the present coating material. Two or more kinds of specific fluorine-containing polymers may be used in combination. When two or more kinds of specific fluorine-containing polymers are used in combination, the total content is preferably within the above range.
Further, in this coating material, a specific fluorine-containing polymer and a fluorine-containing polymer other than the specific fluorine-containing polymer may be used in combination. When the specific fluorine-containing polymer and the fluorine-containing polymer other than the specific fluorine-containing polymer are used in combination, the total of the specific fluorine-containing polymer and the fluorine-containing polymer other than the specific fluorine-containing polymer is the above. It is preferably within the range. When the present coating material contains a specific fluorine-containing polymer and a fluorine-containing polymer other than the specific fluorine-containing polymer, the total mass of the specific fluorine-containing polymer and the fluorine-containing polymer other than the specific fluorine-containing polymer is increased. The content of the specific fluorine-containing polymer is preferably 10 to 90% by mass.

Examples of the method for producing the specific fluorine-containing polymer include a method of copolymerizing a monomer (fluoroolefin, monomer 1 and monomer 2) in the presence of a solvent and a radical polymerization initiator. Further, at least one monomer selected from the group consisting of monomer 3, monomer 4, and monomer 5 may be added, but for the reason described above, monomer 4 and simple are used. It is preferable not to add the monomer 5.
A solution polymerization method is mentioned as a preferable polymerization method in the method for producing a specific fluorine-containing polymer. In the solution polymerization method, the content of Mw and the unit 2 of the specific fluorine-containing polymer can be easily controlled within a predetermined range as compared with the suspension polymerization method and the emulsion polymerization method.
The solvent is preferably alcohol (ethanol, butyl alcohol, propanol, butanol, etc.). Alcohol is superior in solubility of monomer 2 as compared with a non-polar solvent such as xylene. Therefore, if alcohol is used as the polymerization solvent, it is easy to introduce the unit 2 into the specific fluorine-containing polymer in an appropriate amount.

Specific examples of the radical polymerization initiator include peroxydicarbonate, peroxyester, ketone peroxide, peroxyketal, peroxycarbonate ester, diacyl peroxide, dialkyl peroxide and the like.
The reaction temperature in the polymerization is usually 0 to 130 ° C., the reaction pressure is usually 0 to 1.0 MPa, and the reaction time is usually 1 to 50 hours.

This paint contains a curing agent. The curing agent is preferably a compound having two or more groups capable of reacting with a carboxy group in one molecule, and particularly a compound having two or more epoxy groups, carbodiimide groups, oxazoline groups, or β-hydroxyalkylamide groups in one molecule. preferable.
When a fluorine-containing polymer having a hydroxyl group is used, a compound having two or more isocyanate groups or blocked isocyanate groups in one molecule (also referred to as "isocyanate-based curing agent") is usually used as the curing agent. However, since the isocyanate-based curing agent generates ε-caprolactam when it reacts with the hydroxyl group of the fluorine-containing polymer, the heating furnace is contaminated due to the generation of tar, and the generated tar adheres to the coating film surface. The deterioration of the coating film quality due to the above is also a problem. The specific fluorine-containing polymer of the present invention is more environmentally friendly because a coating film can be formed without using an isocyanate-based curing agent.

Examples of the compound having two or more epoxy groups in one molecule include bisphenol type epoxy compounds (A type, F type, S type, etc.), diphenyl ether type epoxy compounds, hydroquinone type epoxy compounds, naphthalene type epoxy compounds, and biphenyl type epoxy compounds. Fluorene type epoxy compound, hydrogenated bisphenol A type epoxy compound, bisphenol A nucleated polyol type epoxy compound, polypropylene glycol type epoxy compound, glycidyl ester type epoxy compound, glycidylamine type epoxy compound, glioxal type epoxy compound, alicyclic epoxy compound , Alicyclic polyfunctional epoxy compound, heterocyclic epoxy compound and the like.
Specific examples of the compound having two or more epoxy groups in one molecule include triglycidyl isocyanurate (hereinafter referred to as "TGIC") and "TM239" (Nissan Chemical Industries, Ltd.) in which a methylene group is introduced into the glycidyl group portion of TGIC. "TEPIC-SP" (manufactured by Nissan Chemical Industries, Ltd.), which is an epoxy compound having a triazine skeleton, and "PT-910" (manufactured by HUNTSMAN), which is a mixture of glycidyl ester of trimellitic acid and glycidyl ester of terephthalate. Can be mentioned.

Examples of the compound having two or more carbodiimide groups in one molecule include alicyclic carbodiimide, aliphatic carbodiimide, aromatic carbodiimide, and multimers and modified products thereof.
Specific examples of compounds having two or more carbodiimide groups in one molecule include dicarbodiimides (N, N'-diisopropylcarbodiimide, N, N'-dicyclohexylcarbodiimide, N, N'-di-2,6-diisopropylphenylcarbodiimide. Etc.), polycarbodiimide (poly (1,6-hexamethylenecarbodiimide), poly (4,4'-methylenebiscyclohexylcarbodiimide), poly (1,3-cyclohexylenecarbodiimide), poly (1,4-cyclohexylenecarbodiimide) ), Poly (4,4'-dicyclohexylmethanecarbodiimide), Poly (4,4'-diphenylmethanecarbodiimide), Poly (3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), Poly (naphthalenecarbodiimide), Poly (P-phenylene carbodiimide), poly (m-phenylene carbodiimide), poly (trilcarbodiimide), poly (diisopropylcarbodiimide), poly (methyl-diisopropylphenylenecarbodiimide), poly (1,3,5-triisopropylbenzene) polycarbodiimide , Poly (1,3,5-triisopropylbenzene) polycarbodiimide, poly (1,5-diisopropylbenzene) polycarbodiimide, poly (triethylphenylene carbodiimide), poly (triisopropylphenylene carbodiimide), etc.).

Examples of the compound having two or more oxazoline groups in one molecule include addition-polymerizable oxazoline having a 2-oxazoline group, a polymer of the addition-polymerizable oxazoline, and the like.
Specific examples of compounds having two or more oxazoline groups in one molecule include 2,2'-bis (2-oxazoline), 2,2'-methylene-bis (2-oxazoline), and 2,2'-ethylene-. Bis (2-oxazoline), 2,2'-trymethylene-bis (2-oxazoline), 2,2'-tetramethylene-bis (2-oxazoline), 2,2'-hexamethylene-bis (2-oxazoline) , 2,2'-octamethylene-bis (2-oxazoline), 2,2'-ethylene-bis (4,5'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis (2- Oxazoline), 2,2'-m-phenylene-bis (2-oxazoline), 2,2'-m-phenylene-bis (4,4'-dimethyl-2-oxazoline), bis (2-oxazolinylcyclohexane) ) Sulfates, bis (2-oxazoline norbornan) sulfides, and oxazoline ring-containing polymers can be mentioned. Commercially available products of compounds having two or more oxazoline groups in one molecule include Epocross WS-500, WS-700, K-2010, K-2020, K-2030 manufactured by Nippon Shokubai Co., Ltd. (all of which are trade names). Can be mentioned.

Specific examples of compounds having two or more β-hydroxyalkylamide groups in one molecule include N, N, N', N'-tetrakis- (2-hydroxyethyl) -adipamide (PrimidXL-552, manufactured by EMS). , N, N, N', N'-tetrakis- (2-hydroxypropyl) -adipamide (Primid QM 1260, manufactured by EMS).

The content of the curing agent is preferably 1 to 50% by mass, more preferably 1 to 20% by mass, based on the specific fluorine-containing polymer in the present coating material. Two or more kinds of curing agents may be used in combination. When two or more types of curing agents are used in combination, the total content is preferably within the above range.

This paint contains a non-fluororesin. The non-fluororesin is a resin that does not contain a fluorine atom.

The non-fluororesin preferably has a reactive group. As a result, the film-forming property of the non-fluororesin is enhanced, the abrasion resistance of the present coating film is improved, the specific fluorine-containing polymer is arranged on the surface side of the coating film, and the non-fluororesin is arranged on the base material side. It becomes easier to obtain a new coating film.
The reactive group is preferably a group capable of reacting with the above-mentioned curing agent, and specific examples thereof include a carboxy group, a hydroxy group, an epoxy group, a glycidyl group, an amino group, a hydrolyzable silyl group and a sulfo group. Be done. As the reactive group, a carboxy group, a hydroxy group, an epoxy group, or a glycidyl group is preferable, and a carboxy group, an epoxy group, or a glycidyl group is particularly preferable, because a non-fluorinated resin is easily arranged on the substrate side.
As the non-fluororesin, at least one selected from polyester resin, (meth) acrylic resin, urethane resin and epoxy resin is preferable.

As the polyester resin, a polymer containing a structure in which a unit based on a polyvalent carboxylic acid and a unit based on a polyhydric alcohol are linked by an ester bond is preferable. The polyester resin may contain a unit based on hydroxycarboxylic acid and the like as a unit other than the unit based on the polyvalent carboxylic acid and the unit based on the polyhydric alcohol.

The polyvalent carboxylic acid is preferably an aromatic carboxylic acid having 8 to 15 carbon atoms. Examples of the polyvalent carboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, trimellitic acid, pyromellitic acid, phthalic acid anhydride and the like.

The polyhydric alcohol is preferably a polyhydric alcohol having 2 to 10 carbon atoms. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol. Examples thereof include neopentyl glycol, spiroglycol, 1,10-decanediol, 1,4-cyclohexanedimethanol, trimethylolethane, trimethylolpropane, glycerin and pentaerythritol.

The polyester resin is preferably a linear polyester resin from the viewpoint of the physical properties of the coating film (particularly, surface smoothness) of the present coating film.
The softening temperature of the polyester resin is preferably 100 to 150 ° C.
The Tg of the polyester resin is preferably 35 to 150 ° C., particularly preferably 50 to 100 ° C., from the viewpoint of blocking resistance of the powder coating material.
The Mn of the polyester resin is preferably 5,000 or less from the viewpoint of surface smoothness of the present coating film. The Mw of the polyester resin is preferably 2,000 to 20,000, particularly preferably 4,000 to 10,000, from the viewpoint of surface smoothness of the present coating film.

Specific examples of the polyester resin include "CRYLCOT (trade name) 4642-3" (hydroxyl value: 3.0 mgKOH / g, acid value: 35 mgKOH / g) and "CRYLCOT (trade name) 4842-" manufactured by Daicel Ornex. 3 ”(hydroxyl value: 3.0 mgKOH / g, acid value: 36 mgKOH / g),“ CRYLCOT (trade name) 4890-0 ”(hydroxyl value: 30 mgKOH / g, acid value: 0.5 mgKOH / g), Japan Yupika "Yupika Coat (trade name) GV-235" (hydroxyl value: 2.0 mgKOH / g, acid value: 39.0 mgKOH / g) manufactured by Japan Yupica Co., Ltd. "Yupica Coat (trade name) GV-260" (hydroxyl value) Value: 2.0 mgKOH / g, acid value: 77.0 mgKOH / g), "Yupikacoat (trade name) GV-740" (hydroxyl value: 50 mgKOH / g, acid value: 3 mgKOH / g), "Yupikacoat (trade name)""GV-150" (hydroxyl value: 34.0 mgKOH / g, acid value: 6.0 mgKOH / g), "Yupikacoat (trade name) GV-110" (hydroxyl value: 49 mgKOH / g, acid value: 3 mgKOH / g), "BIOMUP (trade name)" (hydroxyl value: 32 mgKOH / g, acid value: 3.5 mgKOH / g), DSM "Uralac (trade name) 1680" (hydroxyl value: hydroxyl value: 30 mgKOH / g, acid value) : 3.0 mgKOH / g), DIC's "Findick (trade name) M-8010" (hydroxyl value: 24 mgKOH / g, acid value: 3.0 mgKOH / g), "Findick (trade name) M- "8021" (hydroxyl value: 30 mgKOH / g, acid value: 3.0 mgKOH / g), "Findick (trade name) M-8023" (hydroxyl value: 40 mgKOH / g, acid value: 6.0 mgKOH / g), ""Findick (trade name) M-8842" (hydroxyl value: 3.0 mgKOH / g, acid value: 55 mgKOH / g), "Findick (trade name) M-8860" (hydroxyl value: 3.0 mgKOH / g, acid) Value: 36 mgKOH / g).
Two or more types of polyester resins may be used in combination.

The (meth) acrylic resin is a polymer containing a unit based on the (meth) acrylate.
The (meth) acrylic resin may consist only of units based on (meth) acrylate, or may contain units based on monomers other than (meth) acrylate, such as styrene and (meth) acrylic acid. .. The (meth) acrylate may have a reactive group.

Examples of the (meth) acrylate include alkyl methacrylate (methyl methacrylate, butyl methacrylate, etc.), alkyl acrylate (ethyl acrylate, etc.), hydroxyalkyl (meth) accrilate (hydroxyethyl methacrylate, etc.), glycidyl (meth) acrylate, and the like.

The Tg of the (meth) acrylic resin is preferably 35 to 150 ° C., particularly preferably 30 to 60 ° C., from the viewpoint of blocking resistance of the powder coating material.
The Mn of the (meth) acrylic resin is preferably 6,000 to 250,000, and particularly preferably 40,000 to 150,000, from the viewpoint of surface smoothness of the present coating film.
The Mw of the (meth) acrylic resin is preferably 5,000 to 500,000, preferably 30,000 to 100,000, from the viewpoint of the physical properties of the coating film (particularly, surface smoothness) of the present coating film. Is particularly preferable.
The epoxy equivalent of the (meth) acrylic resin is preferably 200 to 700 g / eq from the viewpoint of the physical properties of the coating film (particularly, the adhesion to the substrate) of the present coating film.

Specific examples of the (meth) acrylic resin include "Findick (trade name) A-254" (epoxy equivalent: 520 g / eq) and "Findick (trade name) A-272" (epoxy equivalent:) manufactured by DIC. 330g / eq), "Findick (brand name) A-701" (epoxy equivalent: 510g / eq), "Findick (brand name) WPR-529" (epoxy equivalent: 530g / eq) "Findick (brand name)" ) A-229-30A ”(Epoxy equivalent: 520 g / eq),“ Findic (trade name) A-261 ”(Epoxy equivalent: 520 g / eq),“ Findick (trade name) A-249 ”(Epoxy equivalent) : 520g / eq), "Findick (brand name) A-266" (epoxy equivalent: 520g / eq), "Findick (brand name) A-251", "Almatex (brand name)" manufactured by Mitsui Chemicals, Inc. Examples include "PD6200", "Almatex (trade name) PD7310", and "Sunpex (trade name) PA-55" manufactured by Sanyo Kasei Kogyo Co., Ltd.
Two or more kinds of (meth) acrylic resins may be used in combination.

The epoxy resin is a compound (prepolymer) having two or more epoxy groups.
Specific examples of the epoxy resin include "Epicoat (trade name) 1001", "Epicoat (trade name) 1002", "Epicoat (trade name) 4004P" manufactured by Mitsubishi Chemical Corporation, and "Epiclon (trade name)" manufactured by DIC. 1050 "," Epicron (trade name) 3050 "," Epototo (trade name) YD-012 "manufactured by Nippon Steel & Sumitomo Metal Corporation," Epototo (trade name) YD-014 "," Denacol (product name) "manufactured by Nagase ChemteX. Name) EX-711 ”,“ EHPE3150 (trade name) ”manufactured by Daicel Ornex, etc. can be mentioned.
Two or more types of epoxy resins may be used in combination.

The urethane resin is a mixture of a polyol (acrylic polyol, polyester polyol, polyether polyol, propylene glycol, etc.) and an isocyanate compound, or a resin obtained by reacting the mixture. As the urethane resin, a resin obtained by reacting a mixture of a powder polyol (acrylic polyol, polyester polyol, polyether polyol) and a powder isocyanate is preferable.

The non-fluororesin may have an acid value or a hydroxyl value, and may have both an acid value and a hydroxyl value. The non-fluororesin preferably has an acid value from the viewpoint of fluidity when the non-fluororesin is melted. When the non-fluororesin has both an acid value and a hydroxyl value, the acid value is preferably larger than the hydroxyl value from the viewpoint of fluidity when the non-fluororesin is melted.
The acid value of the non-fluororesin is preferably 1 to 300 mgKOH / g, more preferably 10 to 150 mgKOH / g, and particularly preferably 20 to 80 mgKOH / g, from the viewpoint of increasing the fluidity when the non-fluororesin is melted.
The hydroxyl value of the non-fluororesin is preferably 1 to 300 mgKOH / g, more preferably 10 to 150 mgKOH / g, and particularly preferably 20 to 80 mgKOH / g from the viewpoint of increasing the film-forming property of the non-fluororesin.

In this paint, the content of the specific fluoropolymer with respect to the content of the non-fluororesin is a mass ratio (specific) because it is superior in abrasion resistance, impact resistance, weather resistance, surface smoothness, etc. of the coating film. Fluorine-containing polymer / non-fluororesin), preferably 0.05 to 20, more preferably 0.10 to 4.0, and particularly preferably 0.20 to 0.80.
The content of the non-fluororesin is preferably 5 to 85% by mass, particularly preferably 10 to 70% by mass, based on the total mass of the present coating material. Two or more types of non-fluororesin may be used in combination. When two or more types of non-fluororesins are used in combination, the total content is preferably within the above range.

In this coating film, the absolute value of the difference between the SP value of the specific fluoropolymer and the SP value of the non-fluororesin is preferably ^{0.4 to 16 (J / cm 3} ) ^1/2.
The absolute value of the difference between the acid value of the specific fluoropolymer and the acid value of the non-fluororesin in this coating material is preferably 0.1 to 50 mgKOH / g, more preferably 1 to 45 mgKOH / g. It is preferably 10 to 40 mgKOH / g, particularly preferably 10 to 40 mgKOH / g.
The absolute value of the Mn difference between the Mn of the specific fluoropolymer and the Mn of the non-fluororesin in the present paint is preferably 1,000 to 200,000, and particularly preferably 10,000 to 150,000.
The absolute value of the Mw difference between the Mn of the specific fluoropolymer and the non-fluororesin in the present paint is preferably 1,000 to 400,000, and particularly preferably 10,000 to 200,000.
As described above, by adjusting the absolute value of the difference in SP value between the specific fluoropolymer and the non-fluororesin, the absolute value of the difference in acid value, the absolute value of the difference in Mn, the absolute value of Mw, etc., it is specified. The fluoropolymer and the non-fluororesin are easily separated, and the specific fluoropolymer is easily arranged on the surface side of the coating film and the non-fluororesin is easily arranged on the base material side of the coating film. Therefore, the wear resistance, impact resistance, etc. of the present coating film are further improved.

The present paint may contain additives if necessary. Specific examples of the additive include curing agents other than the above (curing agents having an isocyanato group, curing agents having a blocked isocyanato group, etc.), curing catalysts, pigments, plasticizers, matting agents, and ultraviolet absorbers (curing agents). Various organic UV absorbers, inorganic UV absorbers, etc.), light stabilizers (hindered amine light stabilizers, etc.), leveling agents, surface conditioners (improve the surface smoothness of the coating film), degassing agents, Examples thereof include fillers, heat stabilizers, thickeners, dispersants, antistatic agents, rust preventives, silane coupling agents, antifouling agents, and decontamination treatment agents.

This coating material preferably contains a curing catalyst as an additive.
The curing catalyst is a compound that promotes a curing reaction when a curing agent is used, and can be selected from known curing catalysts according to the type of curing agent. Two or more types of curing catalysts may be used in combination. When two or more types of curing catalysts are used in combination, the total content is preferably within the above range.

The present paint preferably contains a pigment as an additive. Examples of the pigment include a rust preventive pigment, an extender pigment, a coloring pigment and the like. When the present coating material contains a pigment, the pigment is easily arranged on the substrate side of the coating film together with the non-fluororesin, and contact with the specific fluorine-containing polymer which is easily arranged on the surface side of the coating film is suppressed. Therefore, for example, when a pigment containing titanium oxide is used, the decomposition of the specific fluorine-containing polymer due to the photocatalytic activity of the pigment is suppressed, and the deterioration of the pigment is also suppressed by the specific fluorine-containing polymer. Better in sex.
Specific examples of the rust preventive pigment include zinc cyanamide, zinc oxide, zinc phosphate, calcium magnesium phosphate, zinc molybdate, barium borate, calcium cyanamide and the like.
Specific examples of the extender pigment include talc, barium sulfate, mica, and calcium carbonate.
Specific examples of coloring pigments include quinacridone, diketopyrrolopyrrole, isoindolinone, indanslone, perylene, perinone, anthraquinone, dioxazine, benzoimidazolone, triphenylmethanequinophthalone, anthrapyrimidine, yellow lead, phthalocyanine, and halogenated pigments. Examples thereof include phthalocyanine, azo pigments (azomethine metal complex, condensed azo, etc.), titanium oxide, carbon black, iron oxide, copper phthalocyanine, condensed polycyclic pigments and the like.

Among the coloring pigments, the present coating material preferably contains a bright pigment.
The bright pigment consists of single metal particles or inorganic particles, or metal particles or inorganic particles coated with a coating substance. The metal particles include particles containing metals (metals such as aluminum, zinc, copper, gold, silver, bronze, nickel, titanium, stainless steel and their alloys, etc.) and particles containing oxides of these metals (oxidation). Aluminum particles, iron oxide particles). Examples of the inorganic particles include mica particles (mica powder), pearl particles, graphite particles, glass flakes and the like. Among them, metal particles are preferable, and particles containing aluminum are particularly preferable.
The bright pigment may be in the form of particles, and specific examples thereof include spherical, columnar and flake-like pigments. The flake shape means a flaky shape, and is a concept including a shape such as a scale shape or a flat plate shape.

The coating substance is preferably at least one selected from the group consisting of resins, aliphatic compounds, aromatic compounds, silane compounds and siloxane compounds.
Examples of the resin in the coating substance include a phosphoric acid group-containing resin, a (meth) acrylic resin, and a silicone resin.
Examples of the aliphatic compound include fatty acids and aliphatic amines. The fatty acid is preferably a long-chain fatty acid having 4 to 18 carbon atoms, and specific examples thereof include oleic acid.
Specific examples of the aromatic compound include styrene, α-methylstyrene, vinyltoluene, divinylbenzene, divinylbenzene monooxide, allylbenzene, diallylbenzene and the like.
Examples of the silane compound include a silane coupling agent and the like.
Among these coating substances, (meth) acrylic resin is preferable.
Examples of the coating method with a coating substance include a coating treatment with a resin or the like, a surface coating chemical conversion treatment with a long-chain fatty acid, and the like.
The coating on the surface of the metal particles may be single-layered or multi-layered.

When the present coating material contains a pigment, the content is preferably more than 0% by mass and 40% by mass or less with respect to the total mass of the present coating material. Two or more kinds of pigments may be used in combination. When two or more kinds of pigments are used in combination, the total content is preferably within the above range.

The present paint preferably contains a plasticizer as an additive. The plasticizer improves the film-forming property of the present coating film and improves the surface smoothness.
A known plasticizer can be used as the plasticizer, but a compound having 1 to 4 ester groups (-C (= O) O-) in one molecule from the viewpoint of further improving the flexibility of the present coating film. Is preferable, and a compound having 2 to 4 ester groups is particularly preferable. The plasticizer preferably further has a cyclic hydrocarbon group. The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or a cyclic aromatic hydrocarbon group.

The molecular weight of the plasticizer is preferably 200 to 1,000, more preferably 220 to 980, and particularly preferably 240 to 960, in terms of excellent processability and impact resistance of the present coating film.
The melting point of the plasticizer is preferably 50 to 150 ° C., more preferably 70 to 130 ° C., and particularly preferably 90 to 120 ° C. in terms of excellent processability and impact resistance of the present coating film.
The method for measuring the melting point of the plasticizer is as follows.
The thermal balance of the plasticizer (10 mg) was measured using the Thermal Analysis System (manufactured by PerkinElmer) under the conditions of a temperature range of 25 to 200 ° C. and a heating rate of 5 ° C./min. Let the temperature indicating the melting peak of the chart be the melting point.

Specific examples of the plasticizer include dicyclohexylphthalate (melting point: 68 ° C., molecular weight: 330), tribenzoic acid glyceride (melting point: 68 ° C., molecular weight: 404), pentaerythritol tetrabenzoate (melting point: 108 ° C., molecular weight: 552). ), 1,4-Cyclohexanedimethanol dibenzoate (melting point: 118 ° C., molecular weight: 352), ethylene glycol distearate (melting point: 73.8 ° C., molecular weight 595).

When the present coating material contains a plasticizer, the content is preferably 0.1 to 15% by mass with respect to the total mass of the present coating material. Two or more kinds of plasticizers may be used in combination. When two or more kinds of plasticizers are used in combination, the total content is preferably within the above range.

The present paint preferably contains a matting agent as an additive.
Specific examples of the matting agent include inorganic materials such as silica (for example, ultrafine synthetic silica), calcium carbonate, natural mica, synthetic mica, talc, clay, ceramics, and organic particles (for example, polyethylene particles). Organic materials can be mentioned.
When the present paint contains a matting agent, the content is preferably 0.01 to 10% by mass with respect to the total mass of the present paint. Two or more types of matting agents may be used in combination. When two or more types of matting agents are used in combination, the total content is preferably within the above range.

Examples of the method for producing the present coating material include a method of dry blending powder particles containing a specific fluoropolymer and powder particles containing a non-fluororesin. The dry blend means that each powder particle is mixed without melt-kneading. As described above, the mixture of the powder particles obtained by the dry blend may be used as it is as the present coating material. As a method of adding the curing agent and other components, a method of adding the curing agent and other components in the particles containing the specific fluoropolymer, a method of adding the curing agent and other components in the particles containing the non-fluororesin, and a method of adding the curing agent together with the above powder and drying the particles. There is a method of blending. When the present coating material is obtained by dry blending, it is preferable that the powder particles containing the specific fluoropolymer do not contain the non-fluororesin, and the powder particles containing the non-fluororesin do not contain the specific fluoropolymer.
In addition, as another example of the method for producing the present coating material, raw materials (specific fluoropolymer, non-fluororesin, curing agent, and additive if necessary) are melt-kneaded, and the obtained kneaded product is cooled. , A method of crushing and classifying as necessary to obtain this coating material can be mentioned. Further, the powder particles used in the above-mentioned dry blend (powder particles containing a specific fluoropolymer and powder particles containing a non-fluororesin) may be used as a raw material. The temperature at the time of melt-kneading is preferably 80 to 130 ° C.
The crushing may be performed using a crusher such as a pin mill, a hammer mill, or a jet mill. After the pulverization, it is preferable to classify the pulverized material and make the particle size of the obtained powder coating material uniform.

A first embodiment of the present coating material includes an embodiment containing particles 1A containing a specific fluoropolymer, a non-fluororesin, a curing agent, and if necessary, an additive. That is, it is an embodiment in which these components are contained in one particle constituting the powder. Particle 1A can be obtained by the above-mentioned melt kneading. The particles 1A are preferably particles composed of a specific fluoropolymer, a non-fluororesin, a curing agent, and if necessary, an additive. When the present coating material is the first embodiment, the present coating material preferably consists of powder particles 1A.
In the powder particles 1A, the specific fluoropolymer, the non-fluororesin, and the curing agent were added to the total mass of the powder particles 1A in this order from 10 to 90% by mass, 5 to 85% by mass, and 0. It is preferably contained in an amount of 1 to 45% by mass.

As a modification of the first embodiment, there is an embodiment in which the present coating material further contains powder particles 1B other than powder particles 1A. Examples of the powder particles 1B include powder particles that do not contain a specific fluoropolymer and contain a non-fluororesin other than the non-fluororesin contained in the powder particles 1A and, if necessary, a curing agent. The powder coating material in the modified example of the first embodiment is obtained by dry-blending powder particles 1A and powder particles 1B, and is preferably composed of powder particles 1A and powder particles 1B.
In the modified example of the first embodiment, the content of the powder particles 1A with respect to the content of the powder particles 1B is preferably 0.01 to 99 in terms of mass ratio (powder particles 1A / powder particles 1B), and is 0. .3 to 3 are particularly preferable.
Specific examples of the powder particles 1A include a specific fluoropolymer, a polyester resin having a carboxy group as a non-fluororesin, and a compound having two or more groups capable of reacting with a carboxy group as a curing agent in one molecule. Aspects including. In this embodiment, the acid value of the polyester resin having a carboxy group is preferably 1 to 150 mgKOH / g, particularly preferably 10 to 50 mgKOH / g.
Specific examples of the powder particles 1B include a polyester resin having a hydroxy group as a non-fluororesin and a compound having two or more groups capable of reacting with a hydroxy group as a curing agent in one molecule. In this embodiment, the hydroxyl value of the polyester resin having a hydroxy group is preferably 1 to 150 mgKOH / g, particularly preferably 10 to 50 mgKOH / g.
The content of the non-fluororesin in the powder particles 1B is preferably 5 to 100% by mass with respect to the total mass of the powder particles 1B.

The second embodiment of the present coating material includes powder particles 2A containing a specific fluoropolymer and not containing a non-fluororesin, and powder particles 2B containing a non-fluororesin and not containing a specific fluoropolymer. , At least one of the powder particles 2A and the powder particles 2B contains a curing agent. The powder coating material in the second embodiment is obtained, for example, by dry-blending powder particles 2A and powder particles 2B. When the present coating material is the second embodiment, the present coating material preferably comprises powder particles 2A and powder particles 2B.
The content of the specific fluorine-containing polymer in the powder particles 2A is preferably 10 to 90% by mass with respect to the total mass of the powder particles 2A.
The content of the non-fluororesin in the powder particles 2B is preferably 10 to 90% by mass with respect to the total mass of the powder particles 2B.

The average particle size (50% volume average particle size) of the powder particles in the present coating is preferably 1 to 100 μm. The lower limit is more preferably 25 μm. The upper limit is more preferably 50 μm. When the average particle size is 1 μm or more, the cohesiveness of the specific fluorine-containing polymer is low, and it is easy to uniformly coat the powder during powder coating. Further, when the average particle size is 100 μm or less, the surface smoothness of the coating film becomes better and the appearance of the coating film is good.

The coated article of the present invention has a base material and a coating film formed on the base material by the present paint.
Specific examples of the material of the base material include inorganic substances, organic substances, and organic-inorganic composite materials.
Specific examples of inorganic substances include concrete, natural stone, glass, and metals (iron, stainless steel, aluminum, copper, brass, titanium, etc.).
Specific examples of organic substances include plastics, rubbers, adhesives, and wood.
Specific examples of the organic-inorganic composite material include fiber reinforced plastic, resin reinforced concrete, and fiber reinforced concrete.
Further, as the base material, a material that has undergone a known surface treatment (for example, chemical conversion treatment or the like) may be used. Further, a resin layer (for example, polyester resin, acrylic resin, silicone resin, etc.) formed by applying a primer or the like may be formed on the surface of the base material. When the base material is glass, it is preferable that a resin layer is formed on the base material using a primer such as a silane coupling agent.

Among the above, the base material is preferably metal, more preferably aluminum. The aluminum base material has excellent corrosion resistance, is lightweight, and is suitable for use as a building material such as an exterior member.
The shape, size, etc. of the base material are not particularly limited.
Specific examples of the base material include composite panels, curtain wall panels, curtain wall frames, architectural exterior members such as window frames, automobile members such as tire wheels, construction machinery, and motorcycle frames.

The thickness of the coating film is preferably 20 to 1,000 μm, more preferably 20 to 500 μm. For applications such as members for high-rise buildings such as aluminum curtain walls, 20 to 90 μm is preferable. For applications where weather resistance is high, such as outdoor units of air conditioners installed along the coast, poles of traffic lights, and signs, 100 to 200 μm is preferable.

It is preferable that the coated article is produced by applying the present paint on a base material to form a powder coating layer, and heat-treating the powder coating layer to form a coating film on the base material. The painted article can be rephrased as a base material with a coating film.

The powder coating layer is formed by a coating method such as electrostatic coating method, electrostatic spraying method, electrostatic immersion method, spraying method, flow immersion method, spraying method, spraying method, thermal spraying method, plasma spraying method, etc. Is preferably coated on the substrate. The electrostatic coating method using a powder coating gun is preferable from the viewpoint of being more excellent in surface smoothness and hiding property of the present coating film.
Specific examples of the powder coating gun include a corona charging type coating gun and a triboelectric coating gun. The corona charging type coating gun is a coating gun that sprays powder paint by corona discharge treatment. The triboelectric coating gun is a coating gun in which powder coating is subjected to triboelectric treatment and sprayed.

When the powder coating layer is heat-treated, it is preferable to heat the powder coating layer on the substrate to form a melt film made of a melt of the present coating on the substrate. The molten film may be formed at the same time as the formation of the powder coating layer on the base material, or may be performed separately after the powder coating layer is formed.
In the heat treatment of the powder coating layer, the heating temperature (hereinafter, also referred to as “baking temperature”) and the heating maintenance time (hereinafter, referred to as “baking temperature”) for heating and melting the powder coating layer and maintaining the molten state for a predetermined time. The "baking time") is appropriately set depending on the type and composition of the raw material components of the present paint, the desired thickness of the coating film, and the like, but according to the present paint, the baking temperature can be lowered. That is, according to this paint, a coating film having excellent wear resistance can be formed even by heat treatment at a low temperature.

For example, when the carboxy group of the specific fluorine-containing polymer in the present paint reacts with the above-mentioned curing agent, the present coating film is cured at a lower temperature. The reaction between the carboxy group and the curing agent has an advantage that it does not require a high temperature (about 200 ° C.) as in the case of using a curing agent having an isocyanate group.
The baking temperature is preferably 120 to 210 ° C, more preferably 130 to 190 ° C, more preferably 140 to 180 ° C, and particularly preferably 140 to 170 ° C. The baking time is usually 2 to 60 minutes.
The molten film formed on the substrate is preferably cooled to 20 to 25 ° C. to form a coating film. The cooling may be rapid cooling or slow cooling, and slow cooling is preferable from the viewpoint of substrate adhesion of the present coating film.

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to these examples. The blending amount of each component in the table described later indicates a mass standard. Examples 1 to 5 and 21 are examples, examples 6, 7, 22 and 23 are comparative examples, and example 24 is a reference example.

(Names and abbreviations of ingredients used)
CTFE: Chlorotrifluoroethylene PV: Vinyl ester pivalate UDA: 10-Undecylene acid CHVE: Cyclohexyl vinyl ether HBVE: 4-Hydroxybutyl vinyl ether Non-fluororesin 1: Polyester resin (manufactured by Daicel Ornex, "CRYLCOT (trade name) 4642" -3, hydroxyl value: 3.0 mgKOH / g, acid value: 35 mgKOH / g)
Non-fluororesin 2: Polyester resin (manufactured by Daicel Ornex, "CRYLCOT (trade name) 4890-0", hydroxyl value: 30 mgKOH / g, acid value: 0.5 mgKOH / g)
Non-fluororesin 3: (meth) acrylic resin (manufactured by DIC, "Findick (trade name) A-254", epoxy equivalent: 520 g / eq)
Non-fluororesin 4: Epoxy resin (manufactured by Daicel Ornex, "EHPE3150 (trade name)", epoxy equivalent: 180 g / eq)
Hardener 1: A compound having two or more epoxy groups in one molecule (triglycidyl isocyanurate)
Hardener 2: A compound having two or more blocked isocyanate groups in one molecule (Evonik, Bestagon (trade name) B1530)
Surface conditioner: "BYK-360P (trade name)" manufactured by Big Chemie
Plasticizer: Eastman, "Benzoflex 352 (trade name)"
Degassing agent: Benzoin Pigment: Titanium oxide pigment (DuPont, Ti-Pure R960 (trade name), titanium oxide content: 89% by mass)
Curing catalyst: xylene solution of dibutyltin dilaurate (100-fold diluted product)

[Production of Fluorine-Containing Polymer 1]
In an autoclave (internal volume 2.7 L, made of stainless steel, with stirrer; the same applies hereinafter), tert-butyl alcohol (422 g), xylene (106 g), CTFE (465 g), PV (440 g), and UDA (103 g). Was introduced into an autoclave to raise the temperature, and a 50% by mass xylene solution (47 mL) of tert-butylperoxypivalate was continuously added as a polymerization initiator to carry out the polymerization. After 11 hours, the autoclave was cooled with water to stop the polymerization, and the solution in the autoclave was filtered to obtain a solution containing a fluorine-containing polymer.
The obtained solution was vacuum dried at 65 ° C. for 24 hours to remove the solvent, and further vacuum dried at 130 ° C. for 20 minutes to obtain a block-shaped fluorine-containing polymer 1.
The fluorine-containing polymer 1 was a polymer containing 41 mol%, 50 mol%, and 9 mol% of units based on CTFE, PV, and UDA, respectively, in this order. The fluorine-containing polymer 1 has a Tg of 52 ° C., a Mn of 16,000, an Mw of 59,300, an acid value of 33 mgKOH / g, and a hydroxyl value of 0 mgKOH / g at 170 ° C. The melt viscosity was 81 Pa · s.

[Production of Fluorine-Containing Polymer 2]
Potassium carbonate (12.3 g), xylene (503 g), ethanol (142 g), adsorbent (4.5 g), CTFE (387 g), CHVE (326 g) and HBVE (84.9 g) are charged in an autoclave and evacuated. I was worried.
Next, the polymerization initiator solution (20 mL) was continuously added to carry out the polymerization. During the polymerization, a polymerization initiator solution (19 mL) was continuously added. The polymerization was continued under stirring, and after 11 hours, the autoclave was cooled with water to stop the polymerization, and the solution in the autoclave was filtered to obtain a solution containing a fluorine-containing polymer.
The obtained solution was vacuum dried at 65 ° C. for 24 hours to remove the solvent, and further vacuum dried at 130 ° C. for 20 minutes to obtain a block-shaped fluorine-containing polymer 2.
The fluorine-containing polymer 2 was a polymer containing 50 mol%, 39 mol%, and 11 mol% of units based on CTFE, CHVE, and HBVE in this order, respectively. The fluorine-containing polymer 2 has a Tg of 52 ° C., a Mn of 10,000, a Mw of 45,500, an acid value of 0 mgKOH / g, and a hydroxyl value of 50 mgKOH / g at 170 ° C. The melt viscosity was 161 Pa · s.

[Powder coating production examples 1 to 7]
The components shown in Table 1 are mixed using a high-speed mixer (manufactured by Yuzaki Co., Ltd.) for 10 to 30 minutes, and then at 120 ° C. using a twin-screw extruder (manufactured by Thermoprism, 16 mm extruder). It was melt-kneaded at the barrel set temperature. The obtained kneaded product is cooled, crushed using a crusher (manufactured by FRITSCH, product name: rotor speed mill P14), classified by 150 mesh, and has an average particle size of about 40 μm. 7 powder coating materials were obtained.

[Preparation and evaluation of test pieces 1]
(Examples 1 to 7)
Using each of the powder coatings shown in Table 2, one surface of the chromate-treated aluminum base material was electrostatically coated using an electrostatic coating machine (made by Onoda Cement Co., Ltd., GX3600C) on the aluminum base material. A powder coating layer was formed on the surface. The obtained aluminum substrate with a powder coating layer was held for 20 minutes in an atmosphere of 170 ° C. as a heat treatment. Then, the mixture was cooled to 25 ° C. to obtain an aluminum plate with each coating film having a thickness of 55 to 65 μm. The obtained aluminum plate with a coating film was used as a test piece and evaluated respectively. The results are shown in Table 2.

[Measurement method / evaluation method]
(Content of each unit contained in the fluorine-containing polymer (mol%))
The fluorine-containing polymer was determined by analysis by a molten NMR analysis method.
(Measurement of Mw)
A polystyrene-equivalent Mw was determined using a high-speed GPC device (column TSKgelG 400XL manufactured by Tosoh Corporation).
(Measurement of acid value and hydroxyl value)
According to the method of JIS K 0070-3 (1992), a certain amount of sample is dissolved in a tetrahydrofuran solution and titrated with an ethanol solution of potassium hydroxide using phenolphthalein as an indicator to determine the acid value and hydroxyl value. I asked.
(Measurement of melt viscosity)
Using a rotary rheometer, the value of the viscosity of the sample at 170 ° C. was determined when the temperature was measured from 130 ° C. to 200 ° C. under the condition of a temperature rising rate of 10 ° C./min.

(Abrasion resistance of coating film)
Using a sandfall tester, a sandfall wear test was performed within a diameter of 24 mm on the coating film surface of the test piece in accordance with ASTM D968-93 Volume 06.01. However, the sand falling speed was set to 1 L / min. The amount of reduction of the coating film was calculated from the difference between the film thickness of the coating film before the test and the film thickness of the coating film before the test after the sand had fallen for 18 minutes, and evaluated as follows.
A: The amount of reduction of the coating film is less than 1.5 μm.
B: The amount of reduction of the coating film is 1.5 μm or more and less than 5 μm.
C: The amount of reduction of the coating film is 5 μm or more.

(Impact resistance of coating film)
Judgment was made by the DuPont impact test (JIS K 5600-5-3). Using a DuPont impact tester, a weight was dropped onto the coating film with the coating film surface of the test piece facing up, and the presence or absence of cracks or cracks in the coating film at the drop point of the weight was observed.
A: No cracks, cracks, dents, etc. occur even when dropped from a height of 20 cm or more.
B: Even if dropped from a height of less than 20 cm, cracks, cracks, dents, etc. will occur.

(60 degree mirror gloss of the coating film)
The 60-degree mirror glossiness of the coating film surface on the test piece was measured by JIS K 5600-4-7 and evaluated according to the following criteria. The 60-degree mirror glossiness was measured with a variable-angle gloss meter (trade name "UGV-6P", incoming reflection angle 60 degrees, manufactured by Suga Test Instruments Co., Ltd.).
A: The 60-degree mirror glossiness is 80 degrees or more.
B: 60 degree mirror surface gloss is less than 80 degrees.

(State of coating film cross section)
The test piece was cut perpendicular to the surface of the coating film, and the cross section of the coating film was observed with a scanning electron microscope under the following measurement conditions and judged according to the following criteria.

<Measurement conditions>
Testing machine: JSM-5900LV, manufactured by JEOL Ltd.
Acceleration voltage: 20kV,
Magnification: 10,000 times,
Measurement pretreatment: 20mA, 45 seconds platinum coating by JFC-1300, an auto fine coater manufactured by JEOL Ltd.
<Evaluation criteria>
A: A fluoropolymer layer is present on the surface side of the coating film, and a non-fluororesin layer is present on the base material side of the coating film, and the thickness of the fluoropolymer layer is uniform. Further, the titanium oxide pigment is not exposed on the surface side of the coating film.
B: A fluoropolymer layer is present on the surface side of the coating film, and a non-fluororesin layer is present on the base material side of the coating film, but a part of the fluoropolymer is mixed in the non-fluororesin layer. In addition, there are variations in the thickness of the fluoropolymer layer. In addition, a part of the titanium oxide pigment is exposed on the surface of the coating film.
It was confirmed that the test piece 7 did not have a multi-layer structure in the coating film because it did not contain a non-fluororesin, and the titanium oxide pigment was partially exposed on the surface of the coating film.

As shown in the evaluation results in Table 2, the coating film formed by low-temperature heat treatment using a powder coating material containing a specific fluoropolymer and a non-fluororesin (Examples 1 to 5: powder coating materials 1 to 5) is Abrasion resistance compared to coatings formed by low-temperature heat treatment using powder coatings (Examples 6 to 7: powder coatings 6 to 7) that do not contain a specific fluoropolymer or non-fluororesin. It was shown to be excellent.

[Preparation and evaluation of test pieces 2]
(Examples 21 to 24)
Using each of the powder coatings shown in Table 3, electrostatic coating was performed on one surface of the glass substrate using an electrostatic coating machine (GX3600C, manufactured by Onoda Cement Co., Ltd.), and a powder coating layer was applied on the glass substrate. Was formed. The obtained glass substrate with a powder coating layer was held for 20 minutes in an atmosphere of 170 ° C. as a heat treatment. Then, the glass plate was cooled to 25 ° C. to obtain a glass plate with each coating film having a thickness of 55 to 65 μm. The obtained glass plate with a coating film was used as a test piece and evaluated respectively. The results are shown in Table 3. In Example 24, a silane coupling agent was applied as a primer on a glass substrate to form a primer layer, and then a powder coating was applied.

[Adhesion to glass substrate]
Judgment was made by the cross-cut method (JIS K 5600-5-6). When the coating film of the test piece was cut into a grid pattern of 100 squares at 1 mm intervals, an adhesive tape was attached on it, and then the adhesive tape was peeled off, the adhesive tape did not peel off the 100 squares. Adhesion was evaluated based on the following criteria from the number of squares (number of squares / 100).
A: The number of squares is over 90.
B: The number of squares is less than 90.

As shown in the evaluation results in Table 3, if a powder coating material 5 containing a specific fluoropolymer and a non-fluororesin and the non-fluororesin is an epoxy resin is used, the glass of the coating film obtained without forming a primer layer. It was shown to have excellent adhesion to the substrate. It is considered that this is because the epoxy resin is present on the substrate side of the coating film, so that the epoxy group of the epoxy resin reacts with or interacts with the hydroxyl group on the glass surface.

Claims (14)

A fluoropolymer containing a unit based on a fluoroolefin, a unit based on a monomer represented by the following formula (1), and a unit based on a monomer represented by the following formula (2), a non-fluororesin, and a non-fluororesin. A powder coating characterized by containing a curing agent.
Equation (1) XZ
Equation (2) CHR ²¹ = CR ²² R ²³ COOH
The symbols in the formula have the following meanings.
X is CH ₂ = CHC (O) O-, CH ₂ = C (CH ₃ ) C (O) O-, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O-.
Z is an alkyl group having 4 to 8 carbon atoms represented by the formula −C (Z ¹ ) ₃ , a cycloalkyl group having 6 to 10 carbon atoms, a cycloalkylalkyl group having 6 to 10 carbon atoms, and 6 to 10 carbon atoms. Aryl group or an aralkyl group having 7 to 12 carbon atoms. However, three of Z ¹ are each independently an alkyl group having 1 to 5 carbon atoms, the total number of carbon atoms included in the three Z ¹ is an integer of 3-7.
R ²¹ and R ²² are independently hydrogen atoms or alkyl groups having 1 to 3 carbon atoms.
R ²³ represents a single bond, a divalent saturated hydrocarbon group having 1 to 12 carbon atoms, or a divalent linking group having an ethereal oxygen atom. The powder coating material according to claim 1, wherein the fluorine-containing polymer has an acid value of 5 mgKOH / g or more. The non-fluororesin according to claim 1 or 2, wherein the non-fluororesin is a resin having a reactive group and is at least one selected from the group consisting of a polyester resin, a (meth) acrylic resin, a urethane resin, and an epoxy resin. Powder paint. The content of the unit based on the fluoroolefin is 20 to 60 mol% with respect to all the units contained in the fluoropolymer, and the content of the unit based on the monomer represented by the formula (1) is 5 to 5. The powder coating according to any one of claims 1 to 3, wherein the content is 60 mol% and the content of the unit based on the monomer represented by the formula (2) is 5 to 20 mol%. The fluorine-containing polymer further contains a unit based on the monomer represented by the following formula (3), and the content of the unit is more than 0 mol% and 40 mol% with respect to all the units contained in the fluorine-containing polymer. The powder coating according to any one of claims 1 to 4, which is as follows.
Equation (3) X ^3- Z ³
The symbols in the formula have the following meanings.
X ³ is CH ₂ = CHC (O) O-, CH ₂ = C (CH ₃ ) C (O) O-, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O-.
Z ³ is an alkyl group having 1 to 3 carbon atoms. The fluorine-containing polymer does not contain a unit based on the monomer represented by the following formula (4), or contains the unit, and when the unit is contained, the unit with respect to all the units contained in the fluorine-containing polymer. The powder coating material according to any one of claims 1 to 5, wherein the content of the unit is more than 0 mol% and less than 5 mol%.
Equation (4) X ^4- Q ^4- OH
The symbols in the formula have the following meanings.
X ⁴ is CH ₂ = CHC (O) O-, CH ₂ = C (CH ₃ ) C (O) O-, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O-.
Q ⁴ are an alkylene group having 2 to 20 carbon atoms. The alkylene group may contain a ring structure. The fluorine-containing polymer does not contain a unit based on the monomer represented by the following formula (5), or contains the unit, and when the unit is contained, the unit with respect to all the units contained in the fluorine-containing polymer. The powder coating material according to any one of claims 1 to 6, wherein the content of the unit is more than 0 mol% and less than 8 mol%.
Equation (5) X ^5- Z ⁵
The symbols in the formula have the following meanings.
X ⁵ is CH ₂ = CHC (O) O-, CH ₂ = C (CH ₃ ) C (O) O-, CH ₂ = CHOC (O)-, CH ₂ = CHCH ₂ OC (O)-, CH ₂ = CHO- or CH ₂ = CHCH ₂ O-.
Z ⁵ is an alkyl group having 4 or more carbon atoms, excluding the alkyl group having 4 to 8 carbon atoms represented by the formula −C (Z ¹ ) _3.
Three Z ¹ are each independently an alkyl group having 1 to 5 carbon atoms, the total number of carbon atoms included in the three Z ¹ is an integer of 3-7. The powder coating material according to any one of claims 1 to 7, wherein the curing agent is a compound having two or more epoxy groups, carbodiimide groups, oxazoline groups or β-hydroxyalkylamide groups in one molecule. The powder coating material according to any one of claims 1 to 8, wherein the content of the fluoropolymer with respect to the content of the non-fluororesin is 0.05 to 20 by mass ratio. The powder coating according to any one of claims 1 to 9, further comprising at least one selected from the group consisting of pigments, plasticizers and matting agents. Claim 1 comprising the fluoropolymer, the non-fluororesin, and powder particles containing the non-fluororesin and the curing agent after melt-kneading, cooling, and pulverizing the fluoropolymer, the non-fluororesin, and the curing agent. A method for producing a powder coating material, wherein the powder coating material according to any one of 10 to 10 is obtained. Powder particles containing the fluoropolymer and the curing agent but not the non-fluororesin,
Powder particles containing the non-fluororesin and the curing agent but not containing the fluorine-containing polymer,
A method for producing a powder coating material, wherein the powder coating material according to any one of claims 1 to 10 is obtained. The powder coating material according to any one of claims 1 to 10 is applied onto a base material to form a powder coating layer, and the powder coating layer is heat-treated at 120 to 210 ° C. on the base material. A method for producing a base material with a coating film, which forms a coating film on the surface. A coated article having a base material and a coating film formed on the base material by the powder coating material according to any one of claims 1 to 10.