JP2015232064A - Fluorine-containing coating composition and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorine-containing coating composition capable of forming a cured coating film excellent in acid resistance and weather resistance even containing a flame retardant and the flame retardant is hardly bleeding out from the cured coating film.SOLUTION: The fluorine-containing coating composition containing (A) a fluorine-containing copolymer having a constitutional unit based on fluoroolefin (A1) and a constitutional unit based on a monomer having a crosslinkable group (A2), (B) one or more kind of flame retardant selected from a group consisting of a bromine-based flame retardant, a phosphorous flame retardant, a nitrogen-based flame retardant, a silicone-based flame retardant, a metal oxide-based retardant and metal hydroxide-based flame retardant, (C) a curing agent with the content of the flame retardant (B) of 10 to 100 pts.mass based on 100 pts.mass of the fluorine-containing copolymer (A).

Description

  The present invention relates to a fluorine-containing coating composition and an article.

Conventionally, metal and tempered glass have been used for vehicle surface materials (casing, interior parts, exterior parts, etc.) in terms of strength, durability, safety, etc. Resins are also widely used.
Specific examples of the resin used for the surface material include polycarbonate, acrylic, styrene resin such as acrylonitrile-butadiene-styrene copolymer (ABS) and polystyrene (PS), polypropylene (PP) resin, and polyethylene terephthalate ( Polyester resins such as PET) and polybutylene terephthalate (PBT) are used.

  For the safety of the vehicle, especially in the event of a fire, in order to prevent the fire from spreading, the surface material is required to be highly flame retardant or non-flammable. In order to increase the flame retardancy of the resin surface material, a cured coating film containing a flame retardant is formed on the surface of the surface material.

Typical flame retardants blended in the cured coating film include halogen-based flame retardants such as decabromodiphenyl ether. From the viewpoint of environmental protection, phosphorus flame retardants such as phosphate esters, ammonium phosphates, and ammonium polyphosphates may be used instead of halogen flame retardants.
However, when these flame retardants are contained in a cured coating film, the flame retardant action decreases with time.

On the other hand, a coating agent composition containing a fluororesin and melamine cyanurate as a flame retardant has been proposed as a coating composition having both weather resistance and flame retardancy.
For example, Patent Document 1 discloses that a coating agent composition containing a fluororesin containing melamine cyanurate as a flame retardant has excellent coating performance, and has a weather resistance, moist heat resistance, flame retardancy on a PET film. It is disclosed that a protective layer having excellent properties can be formed.

JP 2011-162598 A

However, the melamine cyanurate of Patent Document 1 tends to bleed out from the cured coating film. Furthermore, since the acid resistance of the cured coating film of Patent Document 1 tends to decrease with time, it is difficult to use in an area where acid rain due to air pollution occurs.
In view of the above circumstances, the present invention can form a cured coating film excellent in acid resistance and weather resistance even if it contains a flame retardant, and the flame retardant is difficult to bleed out from the cured coating film. An object is to provide a fluorine coating composition.

The present invention provides a fluorine-containing coating composition and an article having the following configurations [1] to [8].
[1] a fluorine-containing copolymer (A) having a structural unit (A1) based on a fluoroolefin and a structural unit (A2) based on a monomer having a crosslinkable group;
One or more flame retardants selected from the group consisting of brominated flame retardants, phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, metal oxide flame retardants, and metal hydroxide flame retardants (B )When,
A curing agent (C),
The fluorine-containing coating composition whose content of the said flame retardant (B) is 10-100 mass parts with respect to 100 mass parts of the said fluorine-containing copolymer (A).
[2] The structural unit (A1) based on the fluoroolefin is a structural unit based on one or more selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, and vinyl fluoride. The fluorine-containing coating composition according to [1].
[3] The structural unit (A2) based on the monomer having a crosslinkable group has at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an alkoxysilyl group, an amino group, an epoxy group, and an isocyanate group. The fluorine-containing coating composition according to [1] or [2], which is a structural unit based on a monomer.
[4] The structural unit (A2) based on the monomer having a crosslinkable group is a structural unit based on a monomer having one or both of a hydroxyl group and an alkoxysilyl group, and the curing agent (C) Is at least one selected from metal alkoxide-based curing agents, isocyanate-based curing agents, blocked isocyanate-based curing agents, and amino resin-based curing agents, and includes in any one of [1] to [3]. Fluorine paint composition.

[5] The inclusion according to any one of [1] to [4], wherein the flame retardant (B) has a reactive functional group that reacts with the curing agent (C) or a group that generates the reactive functional group. Fluorine paint composition.
[6] The fluorine-containing coating composition according to any one of [1] to [5], wherein the flame retardant (B) is a phosphorus-based flame retardant.
[7] The fluorine-containing paint composition according to any one of [1] to [6], further comprising at least one pigment (D) selected from the group consisting of a rust preventive pigment, a color pigment, and an extender pigment. object.
[8] An article in which a cured coating film is formed on the surface of a vehicle surface material with the fluorine-containing coating composition according to any one of [1] to [7].

  ADVANTAGE OF THE INVENTION According to this invention, even if it contains a flame retardant, the fluorine-containing coating composition which can form the cured coating film excellent in acid resistance and a weather resistance, and a flame retardant is hard to bleed out from a cured coating film Things can be provided.

In the present specification, the “fluorinated resin” means a polymer compound having a fluorine atom in the molecule.
“(Meth) acrylate” is a general term for acrylate and methacrylate.
In the present specification, a part of or all of the functional groups of the repeating unit directly formed by polymerization of the monomer and the repeating unit formed by polymerization of the monomer are chemically converted to other functional groups. These units are collectively referred to as “structural units”. Hereinafter, in some cases, a unit derived from an individual monomer is referred to as a name obtained by adding “constituent unit based on” to the monomer name.

<Fluorine-containing paint composition>
The fluorine-containing coating composition of the present invention comprises a structural unit (A1) based on a fluoroolefin (hereinafter simply referred to as “structural unit (A1)”) and a structural unit (A2) based on a monomer having a crosslinkable group ( Hereinafter, it simply contains a fluorine-containing copolymer (A) having “structural unit (A2)”, a flame retardant (B), and a curing agent (C), and contains the flame retardant (B). The amount is 10 to 100 parts by mass with respect to 100 parts by mass of the fluorine-containing copolymer (A).

[Fluorine-containing copolymer (A)]
The fluorine-containing copolymer (A) has a structural unit (A1) and a structural unit (A2).
By using the fluorine-containing copolymer (A), it is possible to improve the acid resistance and weather resistance of the cured coating film, and in addition to the flame retardant (B) described later, the flame resistance of the cured coating film The sex can be further improved. Moreover, if a fluorine-containing copolymer (A) is used, it will become difficult for a flame retardant (B) to bleed out from a cured coating film.
The fluorine-containing copolymer (A) optionally has a structural unit (A3) other than the structural unit (A1) and the structural unit (A2) in addition to the structural unit (A1) and the structural unit (A2). Also good.

(Structural unit (A1))
The structural unit (A1) is a structural unit based on a fluoroolefin (hereinafter referred to as “monomer (α1)”).
The monomer (α1) is a compound in which one or more hydrogen atoms of the olefin hydrocarbon (general formula C _n H _2n ) are substituted with fluorine atoms.
2-8 are preferable and, as for carbon number of a monomer ((alpha) 1), 2-6 are more preferable.
The number of fluorine atoms in the monomer (α1) (hereinafter referred to as “fluorine addition number”) is preferably 2 or more, and more preferably 3-4. When the fluorine addition number is 2 or more, the acid resistance and weather resistance of the cured coating film are further improved. Moreover, in combination with the flame retardant (B), the flame retardancy of the cured coating film can be further improved, and furthermore, the flame retardant (B) is less likely to bleed out from the cured coating film.
In the monomer (α1), one or more hydrogen atoms not substituted with fluorine atoms may be substituted with chlorine atoms.

As the monomer (α1), tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, and vinyl fluoride are preferable, and tetrafluoroethylene and chlorotrifluoroethylene are more preferable.
A monomer ((alpha) 1) may be used individually by 1 type, and may use 2 or more types together.
The structural unit (A1) is preferably a structural unit based on one or more selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, and vinyl fluoride.

(Structural unit (A2))
The structural unit (A2) is a structural unit based on the monomer (α2) having a crosslinkable group.
The structural unit (A2) is not particularly limited as long as it is based on a monomer having a crosslinkable group. For example, the structural unit is based on the following monomer (α2-1) to monomer (α2-6). Units are listed.
Monomer (α2-1): a hydroxyl group-containing monomer.
Monomer (α2-2): a carboxyl group-containing monomer.
Monomer (α2-3): an alkoxysilyl group-containing monomer.
Monomer (α2-4): an amino group-containing monomer.
Monomer (α2-5): Epoxy group-containing monomer.
Monomer (α2-6): an isocyanate group-containing monomer.
In the fluorinated copolymer (A), as the structural unit (A2), one type may be used alone, or two or more types may be used in combination.
Hereinafter, the monomer (α2-1) to the monomer (α2-6) will be described in detail.

Monomer (α2-1):
Examples of the monomer (α2-1) include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxy Hydroxyalkyl vinyl ethers such as 2-methylbutyl vinyl ether, 5-hydroxypentyl vinyl ether and 6-hydroxyhexyl vinyl ether; ethylene glycol monovinyl ethers such as diethylene glycol monovinyl ether, triethylene glycol monovinyl ether and tetraethylene glycol monovinyl ether; hydroxyethyl Allyl ether, hydroxybutyl allyl ether, 2-hydroxyethyl allyl ether, 4 Hydroxyalkyl allyl ethers such as hydroxybutyl allyl ether and glycerol monoallyl ether; hydroxyalkyl vinyl esters such as hydroxyethyl vinyl ester and hydroxybutyl vinyl ester; hydroxyalkyl allyl esters such as hydroxyethyl allyl ester and hydroxybutyl allyl ester And (meth) acrylic acid hydroxyalkyl esters such as hydroxyethyl (meth) acrylate.
A monomer ((alpha) 2-1) may be used individually by 1 type, and may use 2 or more types together.

Monomer (α2-2):
Examples of the monomer (α2-2) include 3-butenoic acid, 4-pentenoic acid, 2-hexenoic acid, 3-hexenoic acid, 5-hexenoic acid, 2-heptenoic acid, 3-heptenoic acid, 6- Heptenoic acid, 3-octenoic acid, 7-octenoic acid, 2-nonenoic acid, 3-nonenoic acid, 8-nonenoic acid, 9-decenoic acid or 10-undecenoic acid, acrylic acid, methacrylic acid, vinylacetic acid, crotonic acid, Unsaturated carboxylic acids such as cinnamic acid; saturated carboxylic acids such as vinyloxyvaleric acid, 3-vinyloxypropionic acid 3- (2-vinyloxybutoxycarbonyl) propionic acid, 3- (2-vinyloxyethoxycarbonyl) propionic acid Vinyl ethers; allyloxyvaleric acid, 3-allyloxypropionic acid, 3- (2-allyloxybutoxycarbonyl) propionic acid, 3- (2-ary Saturated carboxylic acid allyl ethers such as xyloxycarbonyl) propionic acid; carboxylic acid vinyl ethers such as 3- (2-vinyloxyethoxycarbonyl) propionic acid and 3- (2-vinyloxybutoxycarbonyl) propionic acid; monovinyl adipate , Saturated polycarboxylic acid monovinyl esters such as monovinyl succinate, vinyl phthalate and vinyl pyromellitic acid; unsaturated dicarboxylic acids such as itaconic acid, maleic acid, fumaric acid, maleic anhydride, itaconic anhydride or the like Intramolecular acid anhydrides; unsaturated carboxylic acid monoesters such as itaconic acid monoester, maleic acid monoester, and fumaric acid monoester.
The monomer (α2-2) can also be obtained by reacting a compound having an acid anhydride group with the monomer (α2-1).
A monomer ((alpha) 2-2) may be used individually by 1 type, and may use 2 or more types together.

Monomer (α2-3):
Examples of the monomer (α2-3) include alkoxysilyl group-containing acrylic acid esters or methacrylic acid esters, vinyl silanes, alkoxysilyl group-containing vinyl ethers, and the like.

The monomer (α2-3) can also be obtained by reacting a compound having a functional group that reacts with and binds to a hydroxyl group and an alkoxysilyl group with the monomer (α2-1). Examples of the “compound having a functional group that reacts with and binds to a hydroxyl group and an alkoxysilyl group” include a compound represented by the following formula (1) (hereinafter referred to as “compound (1)”).
OCN (CH ₂ ) _q SiX _p R ¹ _3-p (1)
(In the formula (1), R ¹ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, X is an alkoxy group having 1 to 5 carbon atoms, p is an integer of 1 to 3, q is Represents an integer of 1 to 5.)

  The reaction between the hydroxyl group of the monomer (α2-1) and the isocyanate group of the compound (1) can be carried out in a yield of almost 100%, but the compound (1) is excessive in order to further increase the reaction rate. Can be reacted. In that case, after removing compound (1) from the reaction product, a polymerization reaction may be carried out to obtain a fluorinated copolymer (A), and the reaction product contains unreacted compound (1). The fluorine-containing copolymer (A) may be obtained by carrying out the polymerization reaction as it is.

  The reaction temperature of the reaction between the monomer (α2-1) and the compound (1) is preferably room temperature to 100 ° C, more preferably 50 to 70 ° C. The reaction is preferably performed in an inert atmosphere such as a nitrogen atmosphere. The reaction time can be appropriately changed according to the progress of the reaction, and is preferably 1 to 24 hours, more preferably 3 to 8 hours. In the reaction solution, an organic metal catalyst such as an organic tin compound, an organic aluminum compound, an organic zirconium compound, or an organic titanate compound is preferably present for the purpose of promoting the reaction.

The monomer (α2-3) can also be obtained by reacting a compound having an alkoxysilyl group with a functional group that reacts with and binds to a carboxyl group with the monomer (α2-2). Examples of the “compound having a functional group that reacts with and binds to a carboxyl group and an alkoxysilyl group” include compounds in which the isocyanate group of the compound (1) is replaced with an epoxy group, a hydroxyl group, or an amino group.
A monomer ((alpha) 2-3) may be used individually by 1 type, and may use 2 or more types together.

Monomer (α2-4):
As the monomer (α2-4), aminovinyl ethers represented by CH ₂ ═CO (CH ₂ ) _x NH ₂ (x = 0 to 10); CH ₂ ═CHOCO (CH ₂ ) _y NH ₂ (y = Allylamines represented by 1 to 10); aminomethylstyrene, vinylamine, acrylamide, vinylacetamide, vinylformamide and the like.
A monomer ((alpha) 2-4) may be used individually by 1 type, and may use 2 or more types together.

Monomer (α2-5):
As the monomer (α2-5), glycidyl vinyl ether, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, 3,4-epoxycyclohexylmethyl vinyl ether, 4-vinyloxymethylcyclohexyl glycidyl ether, etc. Is mentioned.
A monomer ((alpha) 2-5) may be used individually by 1 type, and may use 2 or more types together.

Monomer (α2-6):
Examples of the monomer (α2-6) include 2-isocyanate ethyl methacrylate, 2-isocyanate ethyl acrylate, 2-isocyanate ethyl ethoxy methacrylate, and 2-isocyanate ethyl vinyl ether.
A monomer ((alpha) 2-6) may be used individually by 1 type, and may use 2 or more types together.

  The monomer (α2) having a crosslinkable group may have a fluorine atom. That is, one or more hydrogen atoms bonded to the carbon atoms constituting the structural unit (A2) may be substituted with fluorine atoms.

The monomer (α2) having a crosslinkable group is more excellent in acid resistance and weather resistance of the cured coating film, and combined with the flame retardant, further improves the flame retardancy of the cured coating film, making it difficult to cure from the cured coating film. Monomer (α2-1) from the point that the flame retardant is more difficult to bleed out, the copolymer is excellent in alternating copolymerization with fluoroolefin, and the durability, scratch resistance and impact resistance of the cured coating film are improved. It is preferably at least one selected from the group consisting of monomers (α2-6), and is either one or both of monomer (α2-1) and monomer (α2-3). Is more preferable.
That is, the structural unit (A2) is preferably a structural unit based on a monomer having one or more selected from the group consisting of a hydroxyl group, a carboxyl group, an alkoxysilyl group, an amino group, an epoxy group, and an isocyanate group. More preferably, it is a structural unit based on a monomer having one or both of a hydroxyl group and an alkoxysilyl group.

(Structural unit (A3))
The structural unit (A3) is a structural unit based on the monomer (α3) other than the structural unit (A1) and the structural unit (A2).
The monomer (α3) is preferably a monomer that is copolymerizable with the fluoroolefin and the monomer (α2) having a crosslinkable group and does not have a functional group capable of bonding to the crosslinkable group. .

Specific examples of the monomer (α3) include vinyl ethers, vinyl esters, allyl ethers, and allyl esters.
Examples of vinyl ethers include ethyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, and cyclohexyl vinyl ether. Examples of vinyl esters include vinyl acetate, vinyl pivalate, and vinyl benzoate. Examples thereof include ethyl allyl ether, butyl allyl ether, cyclohexyl allyl ether and the like, and allyl esters include allyl acetate, allyl pivalate, and allyl benzoate.
The monomer (α3) may be an olefin such as ethylene or isobutylene.
A monomer ((alpha) 3) may be used individually by 1 type, and may use 2 or more types together.

(Combination of structural units)
The fluorine-containing copolymer (A) is a point that further improves the acid resistance and weather resistance of the cured coating film, and in combination with the flame retardant (B), further improves the flame retardancy of the cured coating film. From the point that the flame retardant (B) is difficult to bleed out from the cured coating film, the structural unit based on chlorotrifluoroethylene as the structural unit (A1) and 2-hydroxyethyl vinyl ether or 4-hydroxybutyl vinyl ether as the structural unit (A2) It is particularly preferable to have a combination of a structural unit based on at least one of the above and a structural unit based on at least one selected from the group consisting of ethyl vinyl ether, 2-ethylhexyl vinyl ether and cyclohexyl vinyl ether as the structural unit (A3).

(Content of each structural unit)
The content of the structural unit (A1) with respect to the total amount of all the structural units in the fluorinated copolymer (A) is combined with the flame retardant (B) in that it further improves the acid resistance and weather resistance of the cured coating film. In view of further improving the flame retardancy of the cured coating film and the point that the flame retardant (B) makes it difficult to bleed out from the cured coating film, 20.0 to 80.0 mol% is preferable, and 25.0 to 75 is preferable. 0.0 mol% is more preferable, and 30.0 to 70.0 mol% is particularly preferable.
Further, the content of the structural unit (A1) with respect to the total content of the structural unit (A1) and the structural unit (A2) is preferably 50.0 to 99.5 mol%, and 55.0 to 99.0 mol%. More preferred. If the said content of a structural unit (A1) is more than the said lower limit, the acid resistance and weather resistance of a cured coating film will improve more. On the other hand, if the content of the structural unit (A1) is less than or equal to the upper limit, when cured with the curing agent (C) described later, the compatibility with the curing agent (C) becomes good, and during curing. A dense cured coating film can be formed, and the acid resistance and weather resistance of the cured coating film are further improved. Moreover, in combination with the flame retardant (B), the flame retardancy of the cured coating film can be further improved, and furthermore, the flame retardant (B) is less likely to bleed out from the cured coating film.

The content of the structural unit (A2) with respect to the total amount of all the structural units in the fluorinated copolymer (A) improves the acid resistance and weather resistance of the cured coating film by increasing the crosslinking density, and the flame retardant Combined with (B), the flame retardancy of the cured coating is further improved, the flame retardant (B) is less likely to bleed out from the cured coating, and the heat resistance, moisture resistance, From the viewpoint of improving scratch resistance and impact resistance, 20.0 to 80.0 mol% is preferable, 25.0 to 75.0 mol% is more preferable, and 30.0 to 70.0 mol% is particularly preferable.
Moreover, 0.5-50.0 mol% is preferable and, as for content of the structural unit (A2) with respect to the total content of a structural unit (A1) and a structural unit (A2), 1.0-45.0 mol% is preferable. More preferred. If the content of the structural unit (A2) with respect to the total content of the structural unit (A1) and the structural unit (A2) is equal to or higher than the lower limit, the curing agent (C ) And the crosslink density can be increased, a dense cured coating film can be formed upon curing, and the acid resistance and weather resistance of the cured coating film are further improved. Moreover, in combination with the flame retardant (B), the flame retardancy of the cured coating film can be further improved, and furthermore, the flame retardant (B) is less likely to bleed out from the cured coating film. On the other hand, if it is below the said upper limit, stability of a fluorine-containing copolymer (A) will improve, and when using the hardening | curing agent (C) mentioned later, a pot life will improve in the case of formation of a cured coating film.

0-50.0 mol% is preferable and, as for content of the structural unit (A3) with respect to the sum total of all the structural units in a fluorine-containing copolymer (A), 0-45.0 mol% is more preferable. If the content of the structural unit (A3) with respect to the total of all the structural units in the fluorinated copolymer (A) is less than or equal to the above upper limit value, the properties such as acid resistance and weather resistance of the cured coating film are not deteriorated. The characteristics of the structural unit (A3) can be sufficiently exhibited.
The content of each structural unit in the fluorinated copolymer (A) can be controlled by the amount of each monomer charged and the reaction conditions in the polymerization reaction for obtaining the fluorinated copolymer (A).
Further, the content ratio ((A1) :( A2) :( A3)) of the structural unit (A1), the structural unit (A2), and the structural unit (A3) in the fluorine-containing copolymer (A) is 30 to 30 70: 1 to 45: 1 to 45 (however, (A1) + (A2) + (A3) = 100) is preferable, and 40 to 60: 3 to 35: 5 to 40 is more preferable.

(Production method of fluorine-containing copolymer (A))
The method for producing the fluorinated copolymer (A) is not particularly limited as long as it is a method usually used for copolymerizing a monomer having a functional group. For example, the following method (β1) and method (Β2).
Method (β1): A method of copolymerizing a fluoroolefin, a monomer (α2) having a crosslinkable group, and, if necessary, the monomer (α3).
Method (β2): After copolymerizing a fluoroolefin, a monomer (α2) having a crosslinkable group, and a monomer (α3) as necessary, the resulting copolymer is subjected to the crosslinking. A method of reacting a compound having a functional group capable of reacting with a functional group and capable of bonding with a crosslinkable group different from the crosslinkable group (hereinafter referred to as “crosslinkable group converting compound”).
Hereinafter, the method (β1) and the method (β2) will be described in detail.

Method (β1):
For the copolymerization in the method (β1), a known radical polymerization method can be employed, and examples of the polymerization form include solution polymerization, suspension polymerization, emulsion polymerization and the like.
Although the reaction temperature at the time of superposition | polymerization changes also with the radical polymerization initiator to be used, 0-130 degreeC is preferable. The reaction time is preferably 1 to 50 hours.
Examples of the solvent for the polymerization reaction include ion-exchanged water; alcohol solvents such as ethanol, butanol and propanol; saturated hydrocarbon solvents such as n-hexane and n-heptane; aromatic hydrocarbons such as toluene and xylene. Examples of the solvent include ketone solvents such as methyl ethyl ketone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate.

  Examples of the radical polymerization initiator include peroxydicarbonates, peroxyesters, ketone peroxides, peroxyketals, peroxycarbonate esters, diacyl peroxides, dialkyl peroxides, and the like.

In the case of emulsion polymerization, the polymerization can be carried out in water and in the presence of an anionic or nonionic emulsifier using an initiator such as a water-soluble peroxide, a persulfate, or a water-soluble azo compound.
Since a trace amount of hydrochloric acid or hydrofluoric acid may be generated during the polymerization reaction, it is preferable to add a buffer in advance during the polymerization.

Method (β2):
The method (β2) includes the following step (β2-1) and step (β2-2).
Step (β2-1): A step of copolymerizing the fluoroolefin, the monomer (α2) having a crosslinkable group, and, if necessary, the monomer (α3).
Step (β2-2): A step of reacting the copolymer having a crosslinkable group obtained in the step (β2-1) with a crosslinkable group conversion compound.

As a monomer ((alpha) 2) which has a crosslinkable group used at a process ((beta) 2-1), a monomer ((alpha) 2-1) or a monomer ((alpha) 2-2) is preferable.
Moreover, as a crosslinkable group conversion compound in case the monomer ((alpha) 2) which has a crosslinkable group is a monomer ((alpha) 2-1), it reacts and couple | bonds with the compound and acid group which have an acid anhydride group, for example. Examples thereof include compounds having a functional group and an alkoxysilyl group. As the crosslinkable group converting compound when the monomer (α2) having a crosslinkable group is the monomer (α2-2), for example, it has a functional group that reacts with and binds to a carboxyl group and an alkoxysilyl group. Compounds. The crosslinkable group converting compound is preferably compound (1).
Hereinafter, as an example of the method (β2), as a monomer (α2-1), a fluoroolefin, a monomer (α2-1), a monomer (α3) as necessary, a compound (crosslinkable group conversion compound) The case of using 1) will be described.

  The copolymerization of the fluoroolefin, the monomer (α2-1), and the optional monomer (α3) may be performed in the same manner as the copolymerization in the method (β1) (step (β2-1)).

  The reaction between the copolymer obtained in the step (β2-1) and the compound (1) is carried out by using the above compound (1) except that the copolymer is used instead of the monomer (α2-1). What is necessary is just to carry out similarly to the conversion method (process ((beta) 2-2)).

  In the case of producing the fluorine-containing copolymer (A) having an alkoxysilyl group using the compound (1), there is no problem of gelation during the polymerization, and the method (β2) is easy to produce. It is preferable to manufacture by.

  In addition, the manufacturing method of a fluorine-containing copolymer (A) is not limited to the method (β1) and the method (β2) described above. For example, trade name “Lumiflon” (Asahi Glass Co., Ltd.), trade name “Fluonate” (Dainippon Ink Chemical Co., Ltd.), trade name “Cefal Coat” (Central Glass Co., Ltd.), trade name “Zaflon” (Toa Gosei Co., Ltd.) ), A commercially available fluororesin such as “Zeffle” (manufactured by Daikin Industries) may be reacted with a crosslinkable group converting compound to obtain a fluorinated copolymer (A).

(Content of fluorine-containing resin (A))
The content of the fluorine-containing resin (A) in the fluorine-containing coating composition is preferably 40.0 to 95.0 mass%, more preferably 45.0 to 90.0 mass%, and 50.0 to 80.0. More preferred is mass%. If the content of the fluororesin (A) is not less than the lower limit, the acid resistance and weather resistance of the cured coating film can be further improved, and the durability, scratch resistance and impact resistance of the cured coating film can be further improved. Improves. On the other hand, if it is below the said upper limit, peeling and a crack from the surface material of a cured coating film can be suppressed.

[Flame Retardant (B)]
The fluorine-containing coating composition includes a brominated flame retardant (B1), a phosphorus flame retardant (B2), a nitrogen flame retardant (B3), a silicone flame retardant (B4), a metal oxide flame retardant (B5), and The flame retardant (B) which is 1 or more types chosen from the group which consists of a metal hydroxide type flame retardant (B6) is contained. By containing the flame retardant (B), the flame retardancy of the cured coating film is improved, and the burning rate of the surface material for vehicles is suppressed.

A brominated flame retardant (B1) is not specifically limited, A well-known thing can be used. For example, decabromodiphenyl oxide, octabromodiphenyl oxide, tetrabromodiphenyl oxide, tetrabromophthalic anhydride, tetrabromophthalate ester, hexabromocyclododecane, bis (2,4,6-tribromophenoxy) ethane, ethylenebistetrabromo Phthalimide, hexabromobenzene, 1,1-sulfonyl [3,5-dibromo-4- (2,3-dibromopropoxy)] benzene, polydibromophenylene oxide, tetrabromobisphenol-S, tris (2,3-dibromopropyl -1) Isocyanurate, tribromophenol, tribromophenyl allyl ether, octabromodiphenyl ether, tribromoneopentyl alcohol, brominated polystyrene, brominated polyethylene , Tetrabromobisphenol A, tetrabromobisphenol A or a derivative thereof, tetrabromobisphenol A epoxy oligomer or polymer, brominated epoxy oligomer or polymer such as brominated phenol novolac epoxy, tetrabromobisphenol A carbonate oligomer or polymer, tetrabromobisphenol A -Bis (2-hydroxydiethyl ether), tetrabromobisphenol A-bis (2,3-dibromopropyl ether), tetrabromobisphenol A-bis (allyl ether), tetrabromocyclooctane, ethylenebispentabromodiphenyl, tris ( Tribromoneopentyl) phosphate, poly (pentabromobenzyl) acrylate, octabromotrimethylphenylindane, Bromo neopentyl glycol, pentabromobenzyl polyacrylate or its reactant, dibromocresyl glycidyl ether, N, N′-ethylene-bis-tetrabromoterephthalimide, brominated triazine, tribromostyrene or its reactant, tribromophenyl Maleimide or a reactant thereof may be used.
One type of brominated flame retardant (B1) may be used alone, or two or more types may be used in combination.

  A phosphorus flame retardant (B2) is not specifically limited, A well-known thing can be used. Examples thereof include organic phosphorus compounds such as phosphate esters, aromatic condensed phosphate esters, polyphosphates, halogen-containing phosphate esters, halogen-containing condensed phosphate esters, phosphaphenanthrenes, and phosphazenes. .

  Phosphate esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, Tris (phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropylphenyl) phenyl phosphate, monoisodecyl phosphate, 2-acryloyloxyethyl acid phosphate 2-methacryloyloxyethyl acid phosphate, diphenyl-2- Acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, triphenylphosphine oxide, tricresylphosphine oxide, diphenyl methanephosphonate, diethyl phenylphosphonate, phosphate ester Examples include amides.

  Examples of the aromatic phosphoric acid condensed esters include resorcinol polyphenyl phosphate, resorcinol poly (di-2,6-xylyl) phosphate, bisphenol A polycresyl phosphate, hydroquinone poly (2,6-xylyl) phosphate, and these And the like.

Examples of polyphosphates include metal salts of Group 1 to Group 14 of the periodic table, aliphatic amine salts, and aromatic amine salts.
Examples of the metal salt include lithium salt, sodium salt, calcium salt, barium salt, iron (II) salt, iron (III) salt, aluminum salt and the like. Examples of the aliphatic amine salt include methylamine salt, ethylamine salt, diethylamine salt, triethylamine salt, ethylenediamine salt, piperazine salt and the like. Examples of the aromatic amine salt include pyridine salt and triazine.
Examples of halogen-containing phosphate esters include tris (dichloropropyl) phosphate, tris (β-chloropropyl phosphate), tris (chloroethyl phosphate), trischloroethyl phosphate, trisdichloropropyl phosphate, tris (β-chloropropyl) phosphate ) And the like.

Examples of halogen-containing condensed phosphates include 2,2-bis (chloromethyl) trimethylene bis (bis (2-chloroethyl) phosphate), polyoxyalkylene bisdichloroalkyl phosphate, and the like.
The phosphaphenanthrenes include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phospha Phenanthrene-10-oxide, poly (1,3-phenylenemethylphosphonate) and the like can be mentioned.
Examples of phosphazenes include phosphonyl chloride, phosphonitrile chloride / n-propyl alcohol condensate, and phosphazene compounds having a structure in which a phosphorus atom and a nitrogen atom are linked by a double bond.

The phosphorus-based flame retardant (B2) may be produced by a known method, or a commercially available product may be used. Commercially available products include polyoxyalkylene bis dichloroalkyl phosphate (manufactured by Daihachi Chemical Industry, product name: CR-504L), 1,3-phenylenebis (dixylenyl phosphate) (manufactured by Daihachi Chemical Industry, product name) : PX-200), triphenyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd., product name: TPP), 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (manufactured by Sanko Co., Ltd., product) Name: HCA), phosphonyl chloride (manufactured by Otsuka Chemical Co., Ltd., product names: SR-130, SR-140), phosphonitrile chloride / n-propyl alcohol condensate (manufactured by Otsuka Chemical Co., Ltd., product name: SPR-100), etc. Is mentioned.
The phosphorus-based flame retardant (B2) may be used alone or in combination of two or more.

A nitrogen-type flame retardant (B3) is not specifically limited, A well-known thing can be used. For example, nitrogen-containing sulfate, sulfamate, melamine cyanurate, etc. can be mentioned.
Examples of the nitrogen-containing sulfate include ammonium sulfate, dimethylamine sulfate, trimethylamine sulfate, diethylamine sulfate, triethylamine sulfate, diphenylamine sulfate, triphenylamine sulfate, guanidine sulfate, guanylurea sulfate, melamine sulfate and combinations thereof. Among these, triethylamine sulfate, guanidine sulfate, guanylurea sulfate, melamine sulfate or a combination thereof is preferable, guanidine sulfate and melamine sulfate are more preferable, and melamine sulfate is more preferable.
Examples of the sulfamate include those having 2 or more nitrogen atoms in the molecule. Specific examples include ammonium sulfamate, guanidine sulfamate, guanylurea sulfamate, melamine sulfamate, dimethylamine sulfamate, trimethylamine sulfamate, diethylamine sulfamate, triethylamine sulfamate, triphenylamine sulfamate or a combination thereof. . Among them, guanidine sulfamate, guanylurea sulfamate, melamine sulfamate, diethylamine sulfamate, triethylamine sulfamate, or a combination thereof is preferable, and guanidine sulfamate and guanylurea sulfamate are more preferable.
The nitrogen-based flame retardant (B3) may be used alone or in combination of two or more.

A silicone type flame retardant (B4) is not specifically limited, A well-known thing can be used. For example, an organosilicon compound having a two-dimensional or three-dimensional structure, polydimethylsiloxane, or a methyl group in the side chain or terminal of polydimethylsiloxane is a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, or an aromatic hydrocarbon group. And so-called silicone oil or modified silicone oil.
Examples of the substituted or unsubstituted aliphatic hydrocarbon group and aromatic hydrocarbon group include an alkyl group, a cycloalkyl group, a phenyl group, a benzyl group, an amino group, an epoxy group, a polyether group, a carboxyl group, a mercapto group, Examples include a chloroalkyl group, an alkyl higher alcohol ester group, an alcohol group, an aralkyl group, a vinyl group, or a trifluoromethyl group.
One type of silicone flame retardant (B4) may be used alone, or two or more types may be used in combination.

A metal oxide type flame retardant (B5) is not specifically limited, A well-known thing can be used. For example, antimony trioxide, antimony pentoxide, sodium antimonate, zinc hydroxystannate, zinc stannate, metastannic acid, tin oxide, tin oxide salt, zinc sulfate, zinc oxide, ferrous oxide, ferric oxide, Stannous oxide, stannic oxide, zinc borate, ammonium borate, ammonium octamolybdate, metal salt of tungstic acid, complex oxide of tungsten and metalloid, ammonium sulfamate, ammonium bromide, zirconium compounds, Examples include guanidine compounds, fluorine compounds, graphite, and swellable graphite.
A metal hydroxide type flame retardant (B6) is not specifically limited, A well-known thing can be used. Examples thereof include magnesium hydroxide and aluminum hydroxide.
The metal oxide flame retardant (B5) and the metal hydroxide flame retardant (B6) may be used alone or in combination of two or more.

  Among the flame retardants (B) described above, phosphorus-based flame retardants from the point that lowering of flexural modulus and impact resistance is further suppressed, high compatibility with fluororesin, and uniform dispersion in the cured coating film. (B2) is preferred. When the phosphorus flame retardant (B2) is classified into an organic phosphorus compound and an inorganic phosphorus compound, the phosphorus flame retardant (B2) is preferably an organic phosphorus compound. Furthermore, among the organic phosphorus compounds, organic phosphorus compounds having a molecular weight of 100 to 10,000 are preferable.

The flame retardant (B) preferably has a reactive functional group that reacts with the curing agent (C) or a group that generates the reactive functional group.
The “group that generates the reactive functional group” refers to a group that generates a reactive functional group that reacts with the curing agent (C) during production of the fluorine-containing coating composition or formation of a cured coating film. .
The reactive functional group is preferably capable of binding to the functional group in the fluorinated copolymer (A), and specifically includes at least one selected from a hydroxyl group and a carboxyl group.
The reactive functional group in the “group generating the reactive functional group” is preferably one capable of binding to the functional group in the fluorine-containing copolymer (A), and specifically, selected from a hydroxyl group and a carboxyl group. There is at least one kind. Examples of the flame retardant having “the group that generates the reactive functional group” include 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide. The chemical structure “—P (═O) H—O—” in the 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide reacts with water to form a hydroxyl group, It reacts with oxygen below to generate hydroxyl groups.
In the flame retardant (B), the reactive functional group reacting with the curing agent (C) or the reactive functional group generated from the group that generates the reactive functional group is a functional group in the fluorinated copolymer (A). , It becomes difficult to bleed out from the cured coating film.

  In the fluorine-containing coating composition, the content ((B) / (A)) of the flame retardant (B) with respect to 100 parts by mass of the fluorine-containing copolymer (A) is 10 to 100 parts by mass. If the (B) / (A) is 10 parts by mass or more with respect to 100 parts by mass of the fluorinated copolymer (A), the cured coating film is excellent in flame retardancy and suppresses a decrease in the leveling property of the paint. Excellent smoothness of cured coating film. On the other hand, if the (B) / (A) is 100 parts by mass or less with respect to 100 parts by mass of the fluorinated copolymer (A), the cured coating film has excellent acid resistance and weather resistance, and the surface material Less impact on workability.

[Curing agent (C)]
A hardening | curing agent (C) is a compound which has 2 or more of functional groups which have reactivity with respect to the crosslinkable group which fluororesin (A) has. The curing agent (C) plays a role of curing the coating film by reacting with the crosslinkable group of the fluororesin (A) to form a crosslinked structure.
Examples of the curing agent (C) include an isocyanate curing agent (C1), a blocked isocyanate curing agent (C2), an amino resin curing agent (C3), a metal alkoxide curing agent (C4), and the like. It selects according to the kind of crosslinkable group which fluororesin (A) has.
Specifically, for example, when the fluorine-containing resin (A) has a hydroxyl group as a crosslinkable group, an isocyanate curing agent (C1), a blocked isocyanate curing agent (C2), an amino resin curing agent (C3), etc. Is mentioned.
Moreover, when a fluororesin (A) has a carboxyl group as a crosslinkable group, an amine-type hardener, an epoxy-type hardener, etc. are mentioned.
Moreover, when a fluorine-containing resin (A) has an alkoxy silyl group as a crosslinkable group, a metal alkoxide type hardening | curing agent (C4) etc. are mentioned.
Moreover, when a fluororesin (A) has an amino group as a crosslinkable group, a carboxyl group-containing hardening | curing agent, an epoxy-type hardening | curing agent, an acid anhydride type hardening | curing agent, etc. are mentioned.
Moreover, when a fluorine-containing resin (A) has an epoxy group as a crosslinkable group, a carboxyl group-containing hardening | curing agent, an acid anhydride type hardening | curing agent, an amine type hardening | curing agent, etc. are mentioned.
Moreover, when a fluororesin (A) has an isocyanate group as a crosslinkable group, a hydroxyl group containing hardening | curing agent, a carboxyl group containing hardening | curing agent, etc. are mentioned.
Hereinafter, the isocyanate curing agent (C1), the blocked isocyanate curing agent (C2), the amino resin curing agent (C3), and the metal alkoxide curing agent (C4) will be described in detail.

(Isocyanate curing agent (C1))
As an isocyanate type hardening | curing agent (C1), a non-yellowing polyisocyanate and a non-yellowing polyisocyanate modified body are mentioned, for example.
Specific examples of the non-yellowing polyisocyanate include alicyclic polyisocyanates such as isophorone diisocyanate (IPDI) and dicyclohexylmethane diisocyanate (HMDI); and aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI).

Specific examples of the non-yellowing polyisocyanate-modified product include the following modified product (C1-1) to modified product (C1-4).
Modified body (C1-1): Isocyanurate body of aliphatic diisocyanate or alicyclic diisocyanate.
Modified body (C1-2): A modified body having a structure represented by -YC (= O) NH-, which is obtained by modifying an aliphatic diisocyanate or an alicyclic diisocyanate with a polyol or a polyamine.
Modified body (C1-3): A modified body having a structure represented by -YC (= O) NH-, in which a part of the isocyanate group of an isocyanurate of an aliphatic diisocyanate or an alicyclic diisocyanate is modified with a polyol.
Modified body (C1-4): A modified body comprising a mixture of the modified body (C1-1) and the modified body (C1-2).
However, Y in -YC (= O) NH- is an organic group derived from a polyol or polyamine. The number of functional groups possessed by the polyol or polyamine is preferably 2 to 3.

(Blocked isocyanate curing agent (C2))
The blocked isocyanate curing agent (C2) is a blocked isocyanate curing agent in which the isocyanate group of the isocyanate curing agent (C1) is blocked.
The isocyanate group can be blocked with epsilon caprolactam (ECAP), methyl ethyl ketone oxime (MEK-OX), methyl isobutyl ketone oxime (MIBK-OX), pyralidine, triazine (TA) and the like.

(Amino resin curing agent (C3))
Examples of the amino resin curing agent (C3) include melamine resin, guanamine resin, sulfoamide resin, urea resin, aniline resin, and the like. Of these, melamine resins are preferred when it is desired to increase the curing rate.
Specific examples of the melamine resin include alkyl etherified melamine resins that are alkyl etherified. Among these, a melamine resin substituted with a methoxy group and / or a butoxy group is preferable.

(Metal alkoxide curing agent (C4))
Al, Ti, Si, etc. are mentioned as a metal of a metal alkoxide type hardening | curing agent (C4), and a semimetal. Among these, Si is preferable for further improving the weather resistance of the coating film.
As an alkoxy group of a metal alkoxide type hardening | curing agent (C4), a C1-C10 alkoxy group is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is especially preferable.

As the metal alkoxide curing agent (C4), a compound represented by the following formula (2) (hereinafter referred to as “compound (2)”) is preferable.
(R ² ) _4-k Si (OR ³ ) _k (2)
(In the formula (2), R ² and R ³ each independently represent a monovalent hydrocarbon group having 1 to 10 carbon atoms, and k represents an integer of 2 to 4.)

The monovalent hydrocarbon group for R ² may have a substituent. That is, part or all of the hydrogen atoms of the monovalent hydrocarbon group of R ² may be substituted with a substituent. The substituent is preferably a halogen atom, more preferably a fluorine atom.
R ² is preferably a methyl group, an ethyl group, a hexyl group, a decyl group, a phenyl group, or a trifluoropropyl group. When ^two or more R < ² > exists in a compound (2), it is preferable that several R < ² > is mutually the same from the point of the supply property of a raw material. However, several R < ² > may mutually differ.
The monovalent hydrocarbon group for R ³ is an alkyl group having 1 to 10 carbon atoms, preferably a methyl group or an ethyl group, and particularly preferably a methyl group. When two or more R < ³ > exists in a compound (2), it is preferable that several R < ³ > is mutually the same from the point that the reactivity of an alkoxy group becomes the same and it is easy to form a coating film uniformly. However, several R < ³ > may mutually differ.
K in a compound (2) is an integer of 2-4, and 3-4 are preferable.

Specific examples of the compound (2) include tetrafunctional alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane; methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, Trifunctional alkoxysilanes such as hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, and trifluoropropyltrimethoxysilane; bifunctional such as dimethyldimethoxysilane, diphenyldimethoxysilane, dimethyldiethoxysilane, and diphenyldiethoxysilane And functional alkoxysilanes. Among these, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and phenyltrimethoxysilane are preferable from the viewpoint of further improving the curing speed and the properties such as acid resistance and weather resistance of the cured coating film.
A compound (2) may be used individually by 1 type, and may use 2 or more types together.

Compound (2) may be used as a partially hydrolyzed condensate obtained by partial hydrolysis and condensation. The partial hydrolysis-condensation product is a compound obtained by condensing the compound (2) by partial hydrolysis so that two or more hydrolyzable groups (—OR ³ groups) remain in the molecule. It is. Although the overall structure of the partially hydrolyzed condensate is not clear, it is a polysilicate ester composed of a skeleton composed of —Si—O— bonds and an alkoxy group, and the skeleton may be linear or branched. It may be a chain or a cyclic structure.
The partially hydrolyzed condensate of compound (2) is more preferable as the degree of condensation is lower. The lower the degree of condensation of the partially hydrolyzed condensate, the better the compatibility with the fluororesin (A). In addition, the thermal expansion coefficients of the vehicle surface material and the cured coating film are closer, and peeling and cracking from the surface material of the cured coating film due to expansion and contraction due to heat are less likely to occur.

  The method for producing the partially hydrolyzed condensate of compound (2) is not particularly limited, and known methods for producing partially hydrolyzed condensates can be employed. For example, the method of adding at least 1 sort (s) of water, an acid, and a solvent to a compound (2), and making it partially hydrolyze-condensate is mentioned.

As the partially hydrolyzed condensate of compound (2), those having different condensation degrees, structures and types of alkoxy groups are commercially available. For example, trade names “KR-500”, “KR-510”, “KR-” “213” (manufactured by Shin-Etsu Chemical Co., Ltd.), trade names “MKC silicate MS51”, “MKC silicate MS56” (manufactured by Mitsubishi Chemical Corporation), trade names “M silicate 51”, “ethyl silicate 40”, “ethyl” Condensate having an effective silica content of about 28 to 70% by mass such as silicate 45 "(manufactured by Tama Chemical Industry Co., Ltd.), or trade names" HAS-1 "," condensate dissolved in ethanol or isopropanol " HAS-6 "," HAS-10 "(manufactured by Colcoat Co., Ltd.) and the like. The “effective silica content” is a value indicating the content of silica in terms of SiO ₂ when the polyalkyl silicate contained in the product is 100% by mass.
The partial hydrolysis-condensation product of compound (2) may be used individually by 1 type, and may use 2 or more types together.

Examples of the aluminum alkoxide include aluminum isopropoxide (Al [OCH (CH ₃ ) ₂ ] ₃ ) and the like.
Examples of the titanium alkoxide include titanium butoxide (Ti (OC ₄ H ₉ ) ₄ ).
Moreover, you may use the partial hydrolysis-condensation product which partially hydrolyzed and condensed the said aluminum alkoxide and titanium alkoxide so that two or more hydrolysable groups might remain in a molecule | numerator. These partial hydrolysis-condensation products are more preferable as the degree of condensation is lower from the viewpoint that compatibility with the fluorine-containing resin (A) is improved and peeling or cracking of the cured coating film from the surface material is difficult to occur.

Among the above-mentioned curing agents (C), the acid resistance and weather resistance of the cured coating film are further improved, and in combination with the flame retardant (B), the flame resistance of the cured coating film is further improved and difficult. The metal alkoxide type curing agent (C4) and the isocyanate type curing agent (C1) from the point that the flame retardant (B) is less likely to bleed out from the cured coating film, and further difficult to cause peeling or cracking of the coating film from the surface material. It is preferably at least one selected from the group consisting of blocked isocyanate curing agent (C2) and amino resin curing agent (C3). Isocyanate curing agent (C1) and blocked isocyanate curing agent (C2) More preferably, either one or both of the above.
The fluorine-containing resin (A) to be included in combination with these preferable curing agents (C) is preferably a fluorine-containing resin having a crosslinkable group capable of forming a urethane bond with an isocyanate group, and either one of a hydroxyl group and a carboxyl group. Or the fluorine-containing resin which has both is more preferable.

(Content of curing agent (C))
The content of the curing agent (C) is preferably 5.0 to 95.0 parts by mass, more preferably 10.0 to 90.0 parts by mass, with respect to 100 parts by mass of the fluororesin (A). 0-80.0 mass parts is more preferable. If content of a hardening | curing agent (C) is more than the said lower limit, it can prevent that a cured coating film peels from a surface material or a crack generate | occur | produces in a cured coating film. On the other hand, if it is below the said upper limit, the acid resistance and weather resistance of a cured coating film will improve more.

[Other ingredients]
In addition to the fluorine-containing copolymer (A), the flame retardant (B), and the curing agent (C), the fluorine-containing coating composition includes a pigment (D), a curing catalyst (E), another resin (F), a component ( Other components such as G) and solvent (H) may be contained.

(Pigment (D))
The fluorine-containing coating composition preferably contains a pigment (D) for the purpose of rust prevention, coloring, reinforcement and the like of the cured coating film.
The pigment (D) is preferably one or more pigments selected from the group consisting of rust preventive pigments, colored pigments, and extender pigments.
The rust preventive pigment is a pigment for preventing corrosion and alteration of the reflective metal layer. Lead-free rust-proof pigments with low environmental impact are preferred. Examples of lead-free rust preventive pigments include cyanamide zinc, zinc oxide, zinc phosphate, calcium magnesium phosphate, zinc molybdate, barium borate, and calcium cyanamide zinc.
The color pigment is a pigment for coloring the cured coating film. Examples of the color pigment include titanium oxide, carbon black, and iron oxide.
The extender pigment is a pigment for improving the hardness of the cured coating film and increasing the thickness of the cured coating film. Examples of extender pigments include talc, barium sulfate, mica, and calcium carbonate.

  The content of the pigment (D) in the fluorine-containing coating composition is preferably from 50 to 500% by mass, preferably from 100 to 400%, based on the total solid content of the fluorine-containing coating composition (including the curing agent (B)). The mass% is more preferable. If content of a pigment (D) is 50 mass% or more, the function of a pigment (D) will be easy to be obtained. If the content of the pigment (D) is 500% by mass or less, the cured coating film is difficult to be cracked or damaged by the impact of sand or the like, and the properties such as acid resistance and weather resistance of the cured coating film are deteriorated. I won't let you.

(Curing catalyst (E))
The fluorine-containing coating composition preferably contains a curing catalyst (E) for the purpose of accelerating the curing reaction and imparting good chemical performance and physical performance to the cured coating film to be formed. In particular, when curing at a low temperature in a short time, it is more preferable to contain the curing catalyst (E). When the curing catalyst (E) is used, the curing catalyst (E) may remain in the cured coating film.
Examples of the curing catalyst (E) include the following curing catalysts (E1) to (E3).
Curing catalyst (E1): A curing catalyst used for a crosslinking reaction between a fluorine-containing copolymer containing a hydroxyl group and an isocyanate curing agent or a blocked isocyanate curing agent.
Curing catalyst (E2): A curing catalyst used for a crosslinking reaction between a fluorine-containing copolymer containing at least one of an alkoxysilyl group and a hydroxyl group and a metal alkoxide curing agent.
Curing catalyst (E3): A curing catalyst used for a crosslinking reaction between a fluorine-containing copolymer containing a hydroxyl group and an amino resin curing agent.

As the curing catalyst (E1), tin catalysts such as tin octylate, tributyltin dilaurate, and dibutyltin dilaurate are preferable.
As the curing catalyst (E2), acidic phosphoric acid esters such as phosphoric acid monoester and phosphoric acid diester; acidic boric acid esters such as boric acid monoester and boric acid diester; addition reaction between acidic phosphoric acid ester and amine Products, amine adducts such as addition reaction products of carboxylic acid compounds and amines; metal esters such as tin octylate and dibutyltin dilaurate; metals such as tris (acetylacetonate) aluminum and tetrakis (acetylacetonate) zirconium Chelates; metal alkoxide-based curing agents such as aluminum isopropoxide and titanium butoxide. Among these, from the viewpoint of curability and smoothness of the cured coating film, acidic phosphates are preferable. From the viewpoint of curability, smoothness, water resistance, and the like of the cured coating film, a monoalkyl phosphate having 1 to 8 carbon atoms, A dialkyl phosphate having 1 to 8 carbon atoms or a mixture thereof is more preferable.
As the curing catalyst (E3), a blocked acid catalyst is preferable. Examples of the blocked acid catalyst include various amine salts such as carboxylic acid, sulfonic acid, and phosphoric acid. Particularly preferred are higher alkyl-substituted sulfonic acid amine salts such as p-toluenesulfonic acid and diethanolamine salt of dodecylbenzenesulfonic acid and triethylamine salt.
A curing catalyst (E) may be used individually by 1 type, and may use 2 or more types together.

  The content of the curing catalyst (E) is preferably 0.00001 to 10 parts by mass with respect to 100 parts by mass of the solid content in the fluorine-containing coating composition (including the curing agent (C)). When the content of the curing catalyst (E) is 0.00001 part by mass or more, the catalytic effect is sufficiently obtained. When the content of the curing catalyst (E) is 10 parts by mass or less, the remaining curing catalyst (E) does not deteriorate properties such as acid resistance and weather resistance of the cured coating film.

(Other resin (F))
The fluorine-containing coating composition may contain a resin (F) other than the fluorine-containing copolymer (A).
Other resins (F) include acrylic resins, polyester resins, acrylic polyol resins, polyester polyol resins, urethane resins, acrylic silicone resins, silicone resins, alkyd resins, epoxy resins, oxetane resins, amino resin-based curing agents, and the like. Examples thereof include fluorine resins other than fluorine resins and fluorine-containing copolymers (A). The other resin (F) may be a resin that has a crosslinkable group that reacts with the curing agent (B) and is cured by being crosslinked by the curing agent (B). In this case, the combination of the type of the crosslinkable group possessed by the other resin (F) and the type of the curing agent (B) is the combination of the type of crosslinkable group possessed by the fluorine-containing copolymer (A) and the curing agent (B). It is preferable to be the same as the combination of types.
When other resin (F) is blended in the fluorine-containing coating composition, the content of the other resin (F) is preferably 1 to 200 parts by mass with respect to 100 parts by mass of the fluorine-containing copolymer (A). .

(Other optional components (G))
The fluorine-containing coating composition is composed of a fluorine-containing copolymer (A), a flame retardant (B), a curing agent (C), a pigment (D), a curing catalyst (E), and other resins (F). An optional component (G) may be contained.
Other optional components (G) include silane coupling agents for improving the adhesion of cured coatings; light stabilizers such as hindered amine light stabilizers; benzophenone compounds, benzotriazole compounds, triazine compounds, cyano Organic UV absorbers such as acrylate compounds; inorganic UV absorbers such as titanium oxide, zinc oxide and cerium oxide; matting agents such as ultra fine powder synthetic silica; nonionic, cationic or anionic surface activity Agents; leveling agents and the like.
Content of another arbitrary component (G) can be suitably set in the range which does not impair the effect of this invention.

(Solvent (H))
The fluorine-containing coating composition is a composition containing the respective components that form a cured coating film. Furthermore, in order to apply a fluorine-containing coating composition, a component that is not a component that forms a cured coating film can be used together with the fluorine-containing coating composition. In particular, in order to apply the fluorine-containing coating composition, it is preferable to use the solvent (H) mixed with the fluorine-containing coating composition. The composition containing the solvent (H) is applied to form a cured coating film of the fluorine-containing coating composition containing the solvent, and then the solvent (H) is removed to form the coating film of the fluorine-containing coating composition. Is done.
As the solvent (H) for applying the fluorine-containing coating composition, conventionally used solvents such as toluene, xylene, methyl ethyl ketone, butyl acetate and the like can be used. A weak solvent is preferred.
The weak solvent is preferably a weak solvent species that can be used in the polymerization of the fluorinated copolymer (A) or solvent substitution, and more preferably mineral spirits and mineral terpenes.
The content of the solvent (H) in the fluorine-containing coating composition is appropriately determined in consideration of the solubility of the fluorine-containing copolymer (A), an appropriate viscosity when applied as a coating, a coating method, and the like.

[Method for producing fluorine-containing coating composition]
Methods known to those skilled in the art can be used as the method for producing the fluorine-containing coating composition.
For example, when the form of the fluorine-containing paint composition is a solvent-based or solution-type fluorine-containing paint composition such as an emulsion, a method for producing by mixing and dispersing necessary components in a stirrer such as a disper preferable. In the case of a powder system, the raw material in a powder state in which the respective components are mixed in advance is kneaded with a heated extruder, and the extruded kneaded product is cooled, pulverized and classified to obtain a powder having a target particle size. It is preferable to obtain a powder coating material comprising a body and further to form a powder-based fluorine-containing coating composition containing the powder coating material and an additive.
Moreover, the addition time of a hardening | curing agent (C) can be changed with the coating form of a fluorine-containing coating composition. For example, in the case of a one-pack type paint such as a baking paint, it is preferable to add the curing agent (C) immediately after the production of the copolymer. In the case of a two-component fluorine-containing paint composition in which the curing agent (C) and other components are separated, it is preferable to mix the curing agent (C) and other components immediately before coating.

<Article>
The article of the present invention is obtained by forming a cured coating film on the surface of a vehicle surface material with the above-mentioned fluorine-containing coating composition.
The surface material for a vehicle is a member that forms an interior or exterior of a vehicle in which a resin is used, and may be a member that may or may not be visible from the outside in a form in which the vehicle is normally used. Examples of the surface material for vehicles include members used for seats, dashboards, steering, floor mats, bumpers, bonnets, doors, roofs, under covers, floors, windows, light covers, tires, foil covers, wipers, and the like. Can be mentioned.
The method for forming a cured coating film on the surface of a vehicle surface material may be a method for forming a cured coating film that is usually used when using a coating composition. For example, a coating film is formed by applying a fluorine-containing coating composition. And then drying and curing.

(Application method)
Examples of the coating method include sponge coating method, spray coating method, curtain coating (flow coating), roll coating method, casting method, dip coating method, spin coating method, water casting method, die coating method, Langmuir-projet method, A vacuum evaporation method etc. are mentioned.

The coating temperature is preferably 5 to 40 ° C. If it is in the said range, it will be easy to apply and it will be hard to produce uneven coating.
The coating thickness is preferably 5 to 150 μm, more preferably 10 to 100 μm, and even more preferably 20 to 70 μm as the thickness after drying. When the coating thickness is equal to or greater than the lower limit value, the cured coating has sufficient properties such as acid resistance and weather resistance. On the other hand, when the coating thickness is equal to or less than the upper limit value, the cost is reduced and the weight is reduced.

(Dry)
Examples of the drying method include natural drying, vacuum drying, centrifugal drying, and heat drying. Among these, heat drying is preferable because it can be performed as a curing treatment described later.
15-200 degreeC is preferable and the heating temperature in the case of performing heat drying has more preferable 20-150 degreeC. If it is more than the said lower limit, a fluorine-containing coating material composition can fully be hardened, On the other hand, if it is below the said upper limit, it will be hard to generate | occur | produce a bubble etc. in a cured coating film.
When drying by heating, the drying time is preferably 1 minute to 2 weeks, more preferably 3 minutes to 10 days. If it is at least the lower limit value, an uncured portion is unlikely to be generated, while if it is not more than the upper limit value, it is difficult for the coating film to be exposed to bubbles or the like.

(Curing treatment)
Examples of the curing method include thermal curing and photocuring. Among these, a thermosetting treatment is preferable from the viewpoint that the treatment can be performed simultaneously or continuously with the above drying, but a photocuring treatment may be adopted from the viewpoint of improving productivity.
For example, the thermosetting treatment is performed by applying a paint on the surface of a vehicle surface material, drying, and then heating.
The heating temperature is preferably 15 to 200 ° C, particularly preferably 20 to 150 ° C. If it is at least the lower limit value, an uncured portion is unlikely to be generated, while if it is not more than the upper limit value, it is difficult for the coating film to be exposed to bubbles or the like.
The heating time is preferably 1 minute to 2 weeks, more preferably 3 minutes to 10 days.
The thermosetting treatment may also serve as the heat drying.

  As described above, in the present invention, by using the fluorine-containing copolymer (A), the acid resistance and weather resistance of the cured coating film can be improved, and further, it is compatible with the flame retardant (B) described later. Thus, the flame retardancy of the cured coating film can be further improved. Moreover, if a fluorine-containing copolymer (A) is used, it will become difficult for a flame retardant (B) to bleed out from a cured coating film. These effects are complemented by the coating film being cured by the curing agent (C).

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

<Production Example 1>
[Production of fluorinated copolymer solution]
A stainless steel pressure resistant reactor with an internal volume of 2500 mL equipped with a stirrer was charged with bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl). ) -4-Hydroxyphenyl] methyl] butyl malonate (BASF, product name “TINUVIN 144”), 12.43 g of xylene (solvent (H)), ethyl vinyl ether (EVE) (monomer (α2- 1)), 212 g, 4-hydroxybutyl vinyl ether (HBVE) (monomer (α2-1)) 132 g, and cyclohexyl vinyl ether (CHVE) (monomer (α3)) 214 g were charged and degassed with nitrogen. Dissolved oxygen in the liquid was removed. Into this reaction vessel, 677 g of chlorotrifluoroethylene (CTFE) (monomer (α1)) was introduced, and the temperature was gradually raised. When the temperature reached 65 ° C., t-butyl perfluoropolymer as a radical polymerization initiator was obtained. Polymerization was advanced by intermittently adding 12.14 g of oxypivalate (PBPV).
After 10 hours, the reaction was stopped by cooling the reactor with water. After cooling the reaction solution to room temperature, the unreacted monomer is purged, the concentration of the obtained reaction solution is adjusted, and the fluorine-containing copolymer (fluorine-containing copolymer) having a solid content concentration of 60.0% by mass is adjusted. A fluorine-containing copolymer solution containing the polymer (A)) was obtained.

[Production of fluorine-containing coating composition]
To 83 g of the fluorine-containing copolymer solution, 200 g of titanium oxide (trade name “D-918” manufactured by Sakai Chemical Co., Ltd.) (pigment (D)), 43 g of xylene (solvent (H)), butyl acetate (solvent) 43 g of (H)) was added, and 369 g of glass beads having a volume average diameter of 1 mm were further added, followed by stirring with a paint shaker for 2 hours. After stirring, filtration was performed to remove the glass beads to obtain a pigment composition.
Next, 100 g of the pigment composition, 150 g of the fluorine-containing copolymer solution, and a phosphorus-based flame retardant (product name: HCA, 9,10-dihydro-9-oxa-10-phosphor manufactured by Sanko Co., Ltd.) 18.4 g of phenanthrene 10-oxide) (a flame retardant (B)) and an HDI nurate type polyisocyanate resin (trade name “Coronate HX” manufactured by Nippon Polyurethane Co., Ltd.) (curing agent (C)). 5 g and dibutyltin dilaurate as a curing catalyst (curing catalyst (E)) (diluted 4 to 10 times with xylene to 3 g) were further added and mixed to obtain a fluorine-containing coating composition.

<Example 1>
[Evaluation of cured coating film formed with fluorine-containing coating composition]
The fluorine-containing coating composition obtained in Production Example 1 is applied to the surface of the glass substrate by a spray coating method so that the film thickness becomes 40 to 50 μm, and is cured in a temperature-controlled room at 25 ° C. for 1 week. Thus, a cured coating film was formed. Subsequently, the cured coating film was peeled off from the glass substrate to obtain a test piece.
About this test piece, the flame retardance of the cured coating film was evaluated according to the following procedures.

On the surface of the chromate-treated aluminum plate, the fluorine-containing coating composition is applied so as to have a film thickness of 50 μm, and cured for one week in a constant temperature room at 25 ° C. to form a cured coating film. A test plate was obtained.
About this test plate with a cured coating film, as demonstrated below, the acid resistance and weather resistance of the cured coating film, and the bleed-out property of the flame retardant from the cured coating film were evaluated.

(Flame retardance of cured coating)
Evaluation of the flame retardancy of the cured coating film was performed by a vertical combustion test based on UL94. The test was performed 5 times.
The evaluation criteria are “V-0” when the resin composition does not drip during combustion and self-extinguishes within a predetermined time (combustion time within 10 seconds), and there is no resin composition drip during combustion within a predetermined time (combustion time) "V-1" for self-extinguishing within 30 seconds) and "V-2" for self-extinguishing with a resin composition drip during the combustion test and within a predetermined time (within 30 seconds combustion time) Those without fire extinguishing properties were designated as “Do not self-extinguish”.

(Acid resistance of cured coating)
The acid resistance of the cured coating film was evaluated according to the following procedure. First, 10 drops of 1% by mass sulfuric acid aqueous solution was placed on the cured coating film side of the test plate, covered with a watch glass, and allowed to stand for 1 week. Then, it was washed with ion-exchanged water and dried.
The state of the cured coating film was visually evaluated according to the following criteria.
“◯”: No swelling or disappearance of the cured film was confirmed. That is, the base material was not corroded.
“X”: swelling and disappearance of the cured film were confirmed, and the substrate was corroded.

(Weather resistance of cured coating)
The weather resistance of the cured coating film was measured by installing a test plate with a cured coating film outdoors in Naha City, Okinawa Prefecture.
The glossiness of the cured coating film surface immediately before installation and 2 years after installation was measured using PG-1M (gloss meter: manufactured by Nippon Denshoku Industries Co., Ltd.). When the glossiness immediately before installation was 100%, the glossiness ratio after 2 years was calculated as the gloss retention (unit:%).
The weather resistance was evaluated according to the following criteria.
“◯”: The gloss retention was 80% or more.
“Δ”: The gloss retention was 60% or more and less than 80%.
"X": The gloss retention was less than 60%.

(Bleed-out property of flame retardant from cured coating)
The test plate with a cured coating film was allowed to stand for 6 hours at 65 ° C. and 90% RH. Then, by visually observing the surface of the test plate with a cured coating film, whether or not changes caused by bleed-out such as a feeling of stickiness on the surface of the test plate, powder wiping, and precipitation of crystals are observed is as follows. Evaluated by criteria.
“O”: No change is seen.
“Δ”: Some change is observed.
“×”: A significant change is observed.

<Example 2>
A cured coating film was formed and evaluated in the same manner as in Example 1 except that the amount of the flame retardant used in the production of the fluorine-containing coating composition in Production Example 1 was changed to 51.8 g.

<Example 3>
A cured coating film was formed and evaluated in the same manner as in Example 1 except that the amount of the flame retardant used in the production of the fluorine-containing coating composition of Production Example 1 was changed to 103.5 g.

<Example 4>
A cured coating film as in Example 1 except that the flame retardant used in the production of the fluorine-containing coating composition in Production Example 1 and the amount thereof were changed to 51.8 g of decabromodiphenyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.). Was formed and evaluated.

<Comparative Example 1>
A cured coating film was formed and evaluated in the same manner as in Example 1 except that the amount of the flame retardant used in the production of the fluorine-containing coating composition of Production Example 1 was changed to 5.2 g.

  Content ((B) / (A)) (parts by mass) of the flame retardant (B) with respect to 100 parts by mass of the fluorine-containing copolymer (A) in Examples 1 to 4 and Comparative Example 1 described above, curing The evaluation results of the flame retardancy, acid resistance and weather resistance of the coating film, and the bleed-out property of the flame retardant are shown in Table 1 below.

As shown in Table 1, the cured coatings of Examples 1 to 4 and Comparative Example 1 in which the flame retardant (B) was included in the cured coating film containing the fluorine-containing copolymer (A) and the curing agent (C). All the membranes were excellent in acid resistance and weather resistance.
Moreover, the cured coating films of Examples 1 to 4 and Comparative Example 1 had good bleed-out properties of the flame retardant from the cured coating film. In particular, the cured coating films of Examples 1 to 3 and Comparative Example 1 were excellent in the bleed-out property of the flame retardant from the cured coating film.
Moreover, the cured coating film of Examples 1-4 did not drip the resin composition at the time of combustion, and self-extinguished within 30 seconds. In particular, the cured coating films of Examples 1 to 3 self-extinguished within 10 seconds.
However, the cured coating film of Comparative Example 1 did not self-extinguish.

Claims (8)

A fluorine-containing copolymer (A) having a structural unit (A1) based on a fluoroolefin and a structural unit (A2) based on a monomer having a crosslinkable group;
One or more flame retardants selected from the group consisting of brominated flame retardants, phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, metal oxide flame retardants, and metal hydroxide flame retardants (B )When,
A curing agent (C),
The fluorine-containing coating composition whose content of the said flame retardant (B) is 10-100 mass parts with respect to 100 mass parts of the said fluorine-containing copolymer (A).   The structural unit (A1) based on the fluoroolefin is a structural unit based on one or more selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, and vinyl fluoride. Item 2. The fluorine-containing coating composition according to Item 1.   The structural unit (A2) based on the monomer having a crosslinkable group is a monomer having at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an alkoxysilyl group, an amino group, an epoxy group, and an isocyanate group. The fluorine-containing coating composition according to claim 1, wherein the fluorine-containing coating composition is a structural unit based on the above.   The structural unit (A2) based on the monomer having a crosslinkable group is a structural unit based on a monomer having one or both of a hydroxyl group and an alkoxysilyl group, and the curing agent (C) is a metal The fluorine-containing paint composition according to any one of claims 1 to 3, which is at least one selected from an alkoxide-based curing agent, an isocyanate-based curing agent, a blocked isocyanate-based curing agent, and an amino resin-based curing agent. object.   The fluorine-containing paint composition according to any one of claims 1 to 4, wherein the flame retardant (B) has a reactive functional group that reacts with the curing agent (C) or a group that generates the reactive functional group. object.   The fluorine-containing paint composition according to any one of claims 1 to 5, wherein the flame retardant (B) is a phosphorus-based flame retardant.   Furthermore, the fluorine-containing coating composition as described in any one of Claims 1-6 containing 1 or more types of pigments (D) chosen from the group which consists of an antirust pigment, a coloring pigment, and an extender.   An article in which a cured coating film is formed on the surface of a vehicle surface material with the fluorine-containing coating composition according to any one of claims 1 to 7.