JP2015089919A - Coating composition for heat resistant rubber and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition for a heat resistant rubber which can easily form a coating film having durability and non-adhesiveness on a rubber substrate composed of a heat resistant rubber without performing firing and suppress heat deterioration of the rubber substrate, and to provide an article obtained by using the coating composition for a heat resistant rubber.SOLUTION: There is provided a coating composition for a heat resistant rubber which comprises either one or both of a normal temperature-curable type fluorine-containing resin (A) and a resin mixture (B) of a fluorine-containing resin (B1) having a constitutional unit based on vinylidene fluoride (provided that a normal temperature-curable type fluorine-containing resin is excluded) and an acrylic resin (B2) having a glass transition temperature of 50°C or less and a solvent (C). In addition, there is provided an article having a rubber substrate composed of a heat resistant rubber and a coating film which is formed on the rubber substrate by the coating composition for a heat resistant rubber.

Description

  The present invention relates to a heat-resistant rubber coating composition and article.

  Rubber substrates made of heat-resistant rubber such as copy rolls are widely used in printers, copiers, and the like. In such a rubber base material such as a copy roll made of heat-resistant rubber, in order to impart durability and non-tackiness, it is fired after applying a coating composition containing a fluorine-containing resin, and then the rubber base material. It is known to coat the surface.

  For example, in Patent Document 1, a coating composition in which a fluorine-containing molten resin powder having an average particle size of 5 to 1000 μm is dispersed in a liquid medium is applied to the surface of a rubber substrate, and then baked at 340 ° C. Forming a film is disclosed.

JP 2001-54761 A

  However, the method as disclosed in Patent Document 1 has a problem that the rubber base material is thermally deteriorated by firing, although it is made of heat-resistant rubber. There is also a problem that the firing process is complicated.

  The present invention is for a heat resistant rubber that can easily form a coating film having durability and non-adhesiveness on a rubber base material made of a heat resistant rubber and can suppress thermal deterioration of the rubber base material without firing. Provided are a coating composition and an article obtained by using the heat-resistant rubber coating composition.

In order to achieve the above object, the present invention adopts the following configuration.
[1] A room temperature curable fluorine-containing resin (A), a fluorine-containing resin (B1) having a structural unit based on vinylidene fluoride (excluding a room temperature curable fluorine-containing resin) and a glass transition temperature of 50 ° C. A heat-resistant rubber coating composition comprising one or both of the following acrylic resin (B2) resin mixture (B) and solvent (C).
[2] The heat-resistant rubber coating composition according to [1], wherein the room temperature curable fluororesin (A) is a photocurable fluoropolymer (A1).
[3] The heat-resistant rubber coating composition according to [1] or [2], wherein the solvent (C) contains water.
[4] An article having a rubber base material made of a heat-resistant rubber and a coating film formed on the rubber base material with the heat-resistant rubber coating composition of any one of [1] to [3]. .
[5] The article according to [4], wherein the rubber base material is a copy roll.

The coating composition for heat-resistant rubber of the present invention can easily form a coating film having durability and non-adhesiveness on a rubber substrate made of heat-resistant rubber without firing, and the heat of the rubber substrate. Deterioration can be suppressed.
Moreover, the article of the present invention has a coating film with good durability and non-adhesiveness, and the thermal deterioration of the rubber substrate is suppressed.

In this specification, the term “repeating unit directly formed by polymerization of monomers” and the term “repeating unit obtained by chemical conversion of a part of the repeating units formed by polymerization of the monomer” are collectively used. This is called “structural unit”.
In the present specification, the monomer represents a compound having a polymerizable double bond.
In this specification, the description of (meth) acrylic acid represents at least one of acrylic acid and methacrylic acid.
In this specification, description with (meth) acryloyl represents at least one of acryloyl and methacryloyl.
In the present specification, the crosslinkable group means a group that forms a crosslinked structure by reacting with each other or with a curing agent.
In this specification, the substituted oxetanyl group is an oxetanyl group in which a substituent (atom or atomic group other than a hydrogen atom) is bonded to any one or more carbon atoms included in the oxetane ring of the oxetanyl group. Means.
In the present specification, the number average molecular weight of a polymer means a value measured by gel permeation chromatography (GPC) using polystyrene having a known molecular weight as a standard substance.
In the present specification, a compound represented by the formula (1) is referred to as a compound (1). The same applies to compounds represented by other formulas.

≪Coating composition for heat resistant rubber≫
The coating composition for heat-resistant rubber of the present invention (hereinafter sometimes simply referred to as a coating composition) is a coating composition for forming a coating film by coating on the surface of a heat-resistant rubber, and is cured at room temperature. Type fluorine-containing resin (A), fluorine-containing resin (B1) having a structural unit based on vinylidene fluoride (excluding room-temperature-setting type fluorine-containing resins) and acrylic resin having a glass transition temperature of 50 ° C. or lower ( B2) One or both of the resin mixture (B) (hereinafter referred to as acrylic resin (B2)) and the solvent (C) are included. The coating composition of the present invention may contain only one of the room temperature curable fluorine-containing resin (A) and the resin mixture (B), and both the room temperature curable fluorine resin (A) and the resin mixture (B). May be included.
The coating composition of the present invention comprises a photoreaction initiator (D), a compound (E), a photosensitizer (F), a curing agent (G), a curing catalyst (H), and other components as necessary. I) may be included.

<Room-temperature curable fluorine-containing resin (A)>
The room temperature curable fluororesin (A) means a fluororesin that undergoes a curing reaction at room temperature to form a crosslinked structure. Here, normal temperature shall mean 5-40 degreeC.
As the room temperature curing type fluorine-containing resin (A), a photocurable fluorine-containing polymer (A1) (hereinafter also simply referred to as a fluorine-containing polymer (A1)) is preferable.
The coating composition of the present invention particularly preferably contains the fluorinated polymer (A1) from the viewpoint that a coating film can be easily and rapidly formed without firing.

[Fluoropolymer (A1)]
The fluoropolymer (A1) has the following structural unit (α1) and the following structural unit (α2). The fluoropolymer (A1) may have the following structural unit (α3) in addition to the following structural unit (α1) and the following structural unit (α2). Moreover, the fluoropolymer (A1) may further have structural units (α4) other than the following structural units (α1) to (α3).
(Α1) A structural unit based on a fluoroolefin.
(Α2) A structural unit based on a monomer having an oxetanyl group or a substituted oxetanyl group (hereinafter also referred to as monomer (a2)).
(Α3) at least one group selected from the group consisting of an alkenyl group, an alkenyloxy group, a vinyloxycarbonyl group, and a (meth) acryloyloxy group, having no fluorine atom, oxetanyl group, or substituted oxetanyl group Is a structural unit based on a monomer having the following (hereinafter also referred to as monomer (a3)).

(Structural unit (α1))
A fluoroolefin is a compound in which one or more hydrogen atoms of an olefin hydrocarbon (general formula C _n H _2n ) are substituted with a fluorine atom. In the fluoroolefin, one or more hydrogen atoms not substituted with fluorine atoms may be substituted with chlorine atoms.
The number of fluorine atoms in the fluoroolefin (hereinafter referred to as “fluorine addition number”) is preferably 2 or more, more preferably 3 to 6, and even more preferably 3 or 4. If the fluorine addition number is 2 or more, it is easy to form a coating film excellent in weather resistance.

Examples of the fluoroolefin include C2-C3 fluoroolefins such as tetrafluoroethylene (hereinafter referred to as TFE), chlorotrifluoroethylene (hereinafter referred to as CTFE), hexafluoropropylene, vinylidene fluoride, and vinyl fluoride. TFE and CTFE are more preferable from the viewpoint of easily forming a coating film excellent in weather resistance and solvent resistance.
The structural unit (α1) possessed by the fluoropolymer (A1) may be only one type, or two or more types.

(Structural unit (α2))
The monomer (a2) has an oxetanyl group or a substituted oxetanyl group.
As the substituted oxetanyl group, a group having a substituent at the 3-position of the oxetane ring in the oxetanyl group is preferable. Moreover, as a substituent, the C1-C6 alkyl group which may have an etheric oxygen atom is preferable.

Examples of the monomer (a2) include a vinyl ether having an oxetanyl group or a substituted oxetanyl group, an allyl ether having an oxetanyl group or a substituted oxetanyl group, an isopropenyl ether having an oxetanyl group or a substituted oxetanyl group, an oxetanyl group or a substituted oxetanyl group. (Meth) acrylic acid ester having
As the monomer (a2), the following compound (1) is preferable.

However, the formula (1), R ¹ is a hydrogen atom or an ethereal alkyl group oxygen atom 1 to 6 carbon atoms that may have a. R ² is a vinyl group, an allyl group, an isopropenyl group, or a (meth) acryloyl group.
R ¹ in the compound (1) is preferably an alkyl group having 1 to 4 carbon atoms which may have an etheric oxygen atom, and more preferably an alkyl group having 1 to 4 carbon atoms.

Examples of the compound (1) include 3-ethyl-3-vinyloxymethyloxetane, 3-ethyl-3- (4-vinyloxycyclohexyloxymethyl) oxetane, 3-ethyl-3-allyloxymethyloxetane, and 3-methacryloxy. Methyl-3-ethyloxetane and 3-acryloyloxymethyl-3-ethyloxetane are preferred, and 3-ethyl-3-vinyloxymethyloxetane is particularly preferred from the viewpoint of availability and alternating copolymerization with a fluoroolefin.
The structural unit (α2) possessed by the fluoropolymer (A1) may be only one type, or two or more types.

(Structural unit (α3))
The alkenyl group in the monomer (a3) is preferably a vinyl group. Moreover, as an alkenyloxy group, a vinyloxy group, an allyloxy group, and an isopropenyloxy group are preferable.

  Monomers having a vinyloxy group include ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl. Chain alkyl vinyl ethers having a C 1-10 alkyl group such as vinyl ether; cyclic alkyl vinyl ethers having a C 4-10 cycloalkyl group such as cyclohexyl vinyl ether, cyclopentyl vinyl ether, cyclooctyl vinyl ether; Vinyl ethers such as α-unsaturated cyclic ethers such as 3-dihydrofuran, 4-methyl-2,3-dihydrofuran and 3,4-dihydro-2H-pyran are preferred.

  As the monomer having an allyloxy group, allyl ethers such as methyl allyl ether, ethyl allyl ether, isopropyl allyl ether, n-butyl allyl ether, and isobutyl allyl ether are preferable.

  As the monomer having an isopropenyloxy group, isobutyl ethers such as methyl isopropenyl ether, ethyl isopropenyl ether, isopropyl isopropenyl ether, n-butyl isopropenyl ether, and isobutyl isopropenyl ether are preferable.

  Examples of the monomer having a vinyloxycarbonyl group include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl isocaproate, vinyl pivalate, vinyl caprate, vinyl stearate, vinyl benzoate, Vinyl esters such as vinyl versatate and vinyl laurate are preferred.

  Monomers having a (meth) acryloyloxy group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, ( (Meth) acrylic acid esters such as hexyl (meth) acrylate, octyl (meth) acrylate, and allyl (meth) acrylate are preferred.

A monomer having an alkyl group having 1 to 10 carbon atoms and not having a crosslinkable group is preferable from the viewpoint of easily forming a cured coating film having good scratch resistance and chipping property. 2-10 are preferable and, as for carbon number of this alkyl group, 2-8 are more preferable. Specifically, the alkyl group is preferably an ethyl group, a cyclohexyl group, or a 2-ethylhexyl group.
As the monomer (a3) having no crosslinkable group, ethyl vinyl ether, cyclohexyl vinyl ether, and 2-ethylhexyl vinyl ether are particularly preferable.

Moreover, it is preferable that the monomer (a3) has a crosslinkable group from the viewpoint of easily forming a cured coating film having good toughness and solvent resistance. As the crosslinkable group, a hydroxyl group, an alkoxysilyl group, an epoxy group, a carboxy group, an isocyanate group, an amino group, and an amide group are preferable.
As the monomer (a3) having a crosslinkable group, the following monomers (a3-1) to (a3-6) are preferable.
(A3-1) A monomer having a hydroxyl group.
(A3-2) A monomer having an alkoxysilyl group.
(A3-3) A monomer having a carboxy group.
(A3-4) A monomer having an amino group.
(A3-5) A monomer having an isocyanate group.
(A3-6) A monomer having an epoxy group.

  As the monomer (a3-1), hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, cyclohexane dimethanol monovinyl ether; diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, tetraethylene glycol monovinyl ether, etc. Ethylene glycol monovinyl ethers; hydroxyalkyl allyl ethers such as hydroxyethyl allyl ether, hydroxybutyl allyl ether, cyclohexane dimethanol monoallyl ether; hydroxyethyl carboxylic acid vinyl ester, hydroxybutyl carboxylic acid vinyl ester, ((hydroxymethyl Hydroxyalkyl vinyl such as cyclohexyl) methoxy) acetic acid vinyl ester Esters; hydroxyethyl carboxylic acid allyl ester, hydroxybutyl carboxylic acid allyl ester, hydroxyalkyl carboxylic acid allyl esters such as ((hydroxymethylcyclohexyl) methoxy) acetic acid allyl ester; (meth) acrylic such as hydroxyethyl (meth) acrylate Acid hydroxyalkyl esters are preferred.

  As the monomer (a3-2), 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, and trimethoxysilylpropyl vinyl ether are preferable.

  As the monomer (a3-3), (meth) acrylic acid, itaconic acid, fumaric acid, maleic acid, maleic anhydride, citraconic acid, and undecylenic acid are preferable.

  As the monomer (a3-4), aminopropyl vinyl ether and diethylaminoethyl vinyl ether are preferable.

  As the monomer (a3-5), 2-isocyanatoethyl (meth) acrylate and 1,1-bis (acryloylmethyl) ethyl isocyanate are preferable.

  As the monomer (a3-6), glycidyl vinyl ether, glycidyl carboxylic acid vinyl ester, glycidyl allyl ether, and glycidyl (meth) acrylate are preferable.

The structural unit (α3) possessed by the fluoropolymer (A1) may be only one type or two or more types.
The structural unit (α3) may be either a structural unit based on a monomer having a crosslinkable group or a structural unit based on a monomer not having a crosslinkable group, or a combination thereof. May be.

(Structural unit (α4))
The structural unit (α4) is a structural unit based on a monomer other than the fluoroolefin, the monomer (a2), and the monomer (a3) (hereinafter also referred to as the monomer (a4)).
Examples of the monomer (a4) include 1-methoxy-2-methylpropene, 1-ethoxy-2-methylpropene, 1-methoxy-2-methylbutene, 2-methoxy-2-butene, and 2-methoxy-3. -Alkenyl ethers such as methyl-2-butene; olefins such as ethylene, propylene, isobutene, butene, styrene; 1-vinylimidazole, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N- Examples include acrylamides such as diethyl (meth) acrylamide, N-hydroxyethylacrylamide, and 1-vinyl-2-pyrrolidone; vinylsilanes such as vinyltrimethoxysilane and vinylmethyldiethoxysilane.

In addition, the structural unit (α4) is preferably a structural unit based on a monomer containing a phosphorus atom such as vinyl phosphoric acid or vinyl phosphoric acid dimethyl ester in that the coating film is difficult to burn.
The structural unit (α4) possessed by the fluoropolymer (A1) may be only one type, or two or more types.

[Percentage of each structural unit]
The proportion of the structural unit (α1) in the fluoropolymer (A1) is preferably from 30 to 70 mol%, preferably from 40 to 60 mol%, based on the total number of moles of the structural unit (α1) and the structural unit (α2). Is more preferable. When the proportion of the structural unit (α1) is at least the lower limit value, it is easy to form a coating film excellent in weather resistance. When the proportion of the structural unit (α1) is not more than the upper limit value, it is easy to obtain a uniform, colorless and transparent coating composition having good compatibility with the photoreaction initiator (D).

  The proportion of the structural unit (α2) in the fluoropolymer (A1) is preferably from 30 to 70 mol%, preferably from 40 to 60 mol%, based on the total number of moles of the structural unit (α1) and the structural unit (α2). Is more preferable. When the proportion of the structural unit (α2) is at least the lower limit value, the curing rate of the coating composition is increased. When the proportion of the structural unit (α2) is not more than the upper limit value, a coating composition having good storage stability can be easily obtained.

  When the fluoropolymer (A1) has a structural unit (α3), the proportion of the structural unit (α3) to the total structural units in the fluoropolymer (A1) is preferably 5 to 45 mol%, Mole% is more preferable. When the proportion of the structural unit (α3) is within this range, it is easy to ensure sufficient weather resistance of the coating film.

As for the ratio of the structural unit ((alpha) 4) with respect to all the polymerization units in a fluoropolymer (A1), 0-5 mol% is preferable. The proportion of the structural unit (α4) being 0 mol% means that the fluoropolymer (A1) does not have the structural unit (α4).
When the fluoropolymer (A1) has a structural unit (α4), the lower limit of the ratio of the structural unit (α4) to the total polymerization units in the fluoropolymer (A1) is preferably 0.01 mol%.

The lower limit of the fluorine content in the fluoropolymer (A1) is preferably 10% by mass, more preferably 20% by mass, and even more preferably 25% by mass. If fluorine content is more than a lower limit, it will be easy to form the coating film excellent in the weather resistance.
The upper limit of the fluorine content in the fluoropolymer (A1) is preferably 35% by mass. If the fluorine content is not more than the upper limit value, the compatibility with the photoreaction initiator (D) is good, and a uniform, colorless and transparent coating composition is easily obtained.

  The number average molecular weight (Mn) of the fluoropolymer (A1) is preferably 5,000 to 20,000. If Mn of a fluoropolymer (A1) is more than a lower limit, it will be easy to form the coating film excellent in the weather resistance. If Mn of the fluoropolymer (A1) is not more than the upper limit value, it is easy to obtain a coating composition having an appropriate viscosity for application, and a large amount of diluent solvent is not required, so it is easy to reduce the environmental burden. .

(Production method of fluoropolymer (A1))
The production method of the fluoropolymer (A1) is not particularly limited, and a method of polymerizing fluoroolefin, monomer (a2), monomer (a3), monomer (a4), etc. by a known method. Is preferred.

A known radical polymerization method can be adopted as the polymerization method. The polymerization form is not particularly limited, and solution polymerization, suspension polymerization, emulsion polymerization and the like can be employed.
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 polymerization solvent include ion-exchanged water; alcohol solvents such as ethanol, butanol and propanol; saturated hydrocarbon solvents such as n-hexane and n-heptane; aromatic hydrocarbon solvents such as toluene and xylene; Examples thereof 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 the following compounds.
Peroxydicarbonates such as diisopropylperoxydicarbonate and di-n-propylperoxydicarbonate; Peroxyesters such as t-hexylperoxypivalate and t-butylperoxypivalate; cyclohexanone peroxide, methyl ethyl ketone Ketone peroxides such as peroxides; Peroxyketals such as 1,1-bis (t-hexylperoxy) cyclohexane and 1,1-bis (t-butylperoxy) cyclohexane; t-hexyl Peroxy carbonate esters such as peroxy-n-butyl carbonate and t-butyl peroxy-n-propyl carbonate; diacyl peroxides such as isobutyryl peroxide and lauroyl peroxide; dicumyl peroxide, di- - dialkyl peroxides such as butyl peroxide and the like.

When employing emulsion polymerization, the polymerization can be carried out by using an initiator such as a water-soluble peroxide, a persulfate, or a water-soluble azo compound in water and in the presence of an anionic or nonionic emulsifier.
In addition, 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.

[Fluoropolymer (A2)]
The room temperature curable fluororesin (A) may be a fluoropolymer other than the fluoropolymer (A1) as long as it is cured at room temperature. For example, the structural unit (α1) and at least one selected from the group consisting of the monomers (a3-1) to (a3-6) described above (hereinafter also referred to as a structural unit (α5)). ) And a fluoropolymer (A2) not having the structural unit (α2).

In addition to the structural unit (α1) and the structural unit (α5), the fluoropolymer (A2) excludes the structural unit (α1) and the structural unit other than the structural unit (α5) (however, the structural unit (α2) is excluded). (Hereinafter also referred to as a structural unit (α6)).
Examples of the structural unit (α6) include a structural unit based on the monomer (a3) having no crosslinkable group, a structural unit based on the monomer (a4), and the like.

  The ratio of the structural unit (α1) to the total (100 mol%) of the structural unit (α1) and the structural unit (α5) in the fluoropolymer (A2) is preferably 5 to 95 mol%, and 10 to 90 mol%. More preferred. When the proportion of the structural unit (α1) is at least the lower limit value, it is easy to form a coating film excellent in weather resistance. If the proportion of the structural unit (α1) is less than or equal to the upper limit, the compatibility with the curing agent (G) will be good, and it will be dense and excellent in heat resistance, moisture resistance, scratch resistance and impact resistance. Easy to form a coated film.

  The proportion of the structural unit (α5) to the total (100 mol%) of the structural unit (α1) and the structural unit (α5) in the fluoropolymer (A2) is preferably from 5 to 95 mol%, and from 10 to 90 mol%. More preferred. When the proportion of the structural unit (α5) is at least the lower limit value, it is easy to form a coating film having a high crosslink density and being dense and excellent in heat resistance, moisture resistance, scratch resistance and impact resistance. When the proportion of the structural unit (α5) is not more than the upper limit, the stability of the fluoropolymer (A2) is improved, and a coating composition having a long pot life is easily obtained.

  The proportion of the structural unit (α1) relative to the total structural units (100 mol%) of the fluoropolymer (A2) is preferably 20 to 99 mol%, more preferably 30 to 98 mol%, and particularly preferably 40 to 95 mol%. preferable. When the proportion of the structural unit (α1) is at least the lower limit value, it is easy to form a coating film excellent in weather resistance. If the proportion of the structural unit (α1) is less than or equal to the upper limit, the compatibility with the curing agent (G) will be good, and it will be dense and excellent in heat resistance, moisture resistance, scratch resistance and impact resistance. Easy to form a coated film.

  1-80 mol% is preferable, as for the ratio of the structural unit ((alpha) 5) with respect to all the structural units (100 mol%) of a fluoropolymer (A2), 2-70 mol% is more preferable, and 5-60 mol% is especially. preferable. When the proportion of the structural unit (α2) is at least the lower limit value, it is easy to form a coating film having a high crosslink density and a high density and excellent in heat resistance, moisture resistance, scratch resistance and impact resistance. When the proportion of the structural unit (α2) is not more than the upper limit, the stability of the fluoropolymer (A2) is improved, and a coating composition having a long pot life is easily obtained.

0-60 mol% is preferable and, as for the ratio of the structural unit ((alpha) 6) with respect to all the structural units (100 mol%) of a fluoropolymer (A2), 0-50 mol% is more preferable. When the proportion of the structural unit (α6) is not more than the upper limit value, it is easy to form a coating film excellent in weather resistance, and the adhesion between the rubber substrate and the coating film becomes good.
The proportion of the structural unit (α6) being 0 mol% means that the fluoropolymer (A2) does not have the structural unit (α6).
When the fluoropolymer (A2) has a structural unit (α6), the lower limit of the proportion of the structural unit (α6) is preferably 0.5 mol%.

When the fluoropolymer (A2) has a hydroxyl group, the hydroxyl value of the fluoropolymer (A2) is preferably from 1.0 to 250.0 mgKOH / g, more preferably from 5.0 to 200.0 mgKOH / g. If the hydroxyl value of the fluorinated polymer (A2) is less than the lower limit, the crosslinking density when the coating is cured may be low, and the solvent resistance of the coating may be reduced. If the hydroxyl value of a fluoropolymer (A2) is below an upper limit, it will be excellent in the water resistance and acid rain resistance of a coating film.
The hydroxyl value is measured according to JIS K1557-1 (2007 edition).

  The Mn of the fluoropolymer (A2) is preferably from 3,000 to 100,000, more preferably from 4,000 to 50,000. If Mn of a fluoropolymer (A2) is more than a lower limit, it will be easy to form the coating film excellent in the weather resistance. If Mn of the fluoropolymer (A2) is not more than the upper limit value, it is easy to obtain a coating composition having an appropriate viscosity for application, and a large amount of diluting solvent is not required. .

  The manufacturing method of a fluoropolymer (A2) is not specifically limited, For example, the method similar to a fluoropolymer (A1) is mentioned.

<Resin mixture (B)>
The resin mixture (B) is a mixture of a fluorine-containing resin (B1) having a structural unit based on vinylidene fluoride (excluding a room temperature curing type fluorine-containing resin) and an acrylic resin (B2).
With the fluororesin (B1), excellent durability and non-adhesiveness can be obtained. Further, the acrylic resin (B2) provides sufficient film formability without firing.

[Fluororesin (B1)]
The fluororesin (B1) has a structural unit based on vinylidene fluoride (hereinafter also referred to as a structural unit (β1)).
The fluororesin (B1) has a structural unit based on a monomer other than vinylidene fluoride (excluding a monomer having a crosslinkable group; hereinafter also referred to as monomer (b1)). You may not have. That is, the fluororesin (B1) may be a homopolymer of vinylidene fluoride or a copolymer of vinylidene fluoride and the monomer (b1).

The monomer (b1) is preferably a fluorine-containing monomer, more preferably tetrafluoroethylene or hexafluoropropylene, from the viewpoint that excellent durability and non-adhesiveness can be easily obtained.
The monomer (b1) used for the fluororesin (B1) may be one type or two or more types.

The proportion of the structural unit (β1) with respect to all the structural units of the fluororesin (B1) is preferably 50 mol% or more, more preferably 70 mol% or more from the viewpoint of film formability.
The upper limit of the ratio of the structural unit (β1) to the total structural units of the fluororesin (B1) is 100 mol%.

The Mn of the fluororesin (B1) is preferably 50,000 to 300,000, more preferably 100,000 to 250,000. If Mn of a fluororesin (B1) is more than a lower limit, it will be easy to form the coating film excellent in the weather resistance. If Mn of a fluororesin (B1) is below an upper limit, it will be easy to obtain the coating composition which has moderate viscosity for application | coating, and since a large amount of dilution solvents are not required, it is easy to reduce an environmental burden.
The average particle size of the fluororesin (B1) is preferably 0.04 to 2.9 μm.

The method for producing the fluororesin (B1) is not particularly limited, and examples thereof include the same method as that for the fluoropolymer (A1).
A commercially available product may be used as the fluorine-containing resin (B1).

[Acrylic resin (B2)]
The acrylic resin (B2) is not particularly limited as long as the glass transition temperature is 50 ° C. or lower.
As the acrylic resin (B2), for example, a structural unit (hereinafter also referred to as a structural unit (β2)) based on at least one monomer (b2) selected from the group consisting of alkyl acrylates and alkyl methacrylates. ). In addition, the acrylic resin (B2) has a structural unit (hereinafter also referred to as a structural unit (β3)) based on the monomer (b3) copolymerizable with the monomer (b2) as necessary. It may be.

Monomer (b2):
As the acrylic acid alkyl ester, an acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms is preferable. Specifically, for example, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate Etc.

As the methacrylic acid alkyl ester, a methacrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms is preferable. Specifically, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate Etc.
The structural unit (β2) included in the acrylic resin (B2) may be one type or two or more types.

Monomer (b3):
The monomer (b3) is not particularly limited, and examples thereof include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, crotonic acid, and itaconic acid; vinyl compounds such as vinyl acetate; acrylamide, Methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N, N-dialkylacrylamide, N, N-dialkylmethacrylamide Amide compounds such as 2-hydroxyethyl acrylate, N-dialkylaminoethyl acrylate, glycidyl acrylate, fluoroalkyl acrylate, etc .; dialkylaminoethyl methacrylate, fluoroalkyl methacrylate, And methacrylic acid esters such as 2-hydroxyethyl methacrylate, glycidyl methacrylate, and ethylene glycol dimethacrylate; vinyl ether compounds such as allyl glycidyl ether; Also, conjugated dienes such as 1,3-butadiene and isoprene; aromatic vinyl compounds such as styrene, α-methylstyrene and halogenated styrene; divinyl compounds such as divinylbenzene; vinyl cyanide such as acrylonitrile and methacrylonitrile are used. May be.

As the monomer (b3), acrylic acid, methacrylic acid, itaconic acid, fumaric acid, N-methylol acrylamide, N-methylol methacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, allyl glycidyl ether, 1,3-butadiene, styrene, and acrylonitrile are preferred.
The structural unit (β3) contained in the acrylic resin (B2) may be one type or two or more types.

The proportion of the structural unit (β2) relative to the total structural units of the acrylic resin (B2) is preferably 50 mol% or more, more preferably 70 mol% or more, from the viewpoint of the water resistance of the resulting coating film.
The upper limit of the ratio of the structural unit (β2) to the total structural unit of the acrylic resin (B2) is 100 mol%.

The glass transition temperature of an acrylic resin (B2) is 50 degrees C or less, 0-45 degreeC is preferable and 20-40 degreeC is more preferable. If the glass transition temperature of an acrylic resin (B2) is below an upper limit, the coating film excellent in surface smoothness can be formed. When the glass transition temperature of the acrylic resin (B2) is at least the lower limit value, a coating film having sufficient hardness can be obtained.
The glass transition temperature is measured by differential scanning calorimetry.

  The Mn of the acrylic resin (B2) is preferably 1,000 to 5,000,000, and more preferably 5,000 to 1,000,000. If Mn of an acrylic resin (B2) is more than the said lower limit, the solvent resistance of a coating film will be excellent. If Mn of an acrylic resin is below the said upper limit, the coating film excellent in surface smoothness can be formed.

The manufacturing method of an acrylic resin (B2) is not specifically limited, For example, the method similar to a fluoropolymer (A1) is mentioned. The acrylic resin (B2) may be produced by polymerizing the monomer (b2) and the monomer (b3) used as necessary in the presence of the fluororesin (B1).
Commercial products may be used for the acrylic resin (B2).

<Solvent (C)>
The coating composition of this invention can improve coating performance and workability | operativity by mix | blending a solvent (C) and reducing a viscosity.
As the solvent (C), water or a solvent may be used. In terms of reducing environmental burden, the solvent (C) preferably contains water.

  The solvent is not particularly limited. For example, ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, ethyl butyl ketone, diisobutyl ketone, cyclohexanone, isophorone; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n acetate -Esters such as butyl, isobutyl acetate, t-butyl acetate; toluene, xylene, ethylbenzene, aromatic petroleum naphtha, tetralin, turpentine oil, Solvesso # 100 (registered trademark of Exxon Chemical Co., Ltd.), Solvesso # 150 (Exxon Chemical) Aromatic hydrocarbons such as (registered trademark); ethers such as dioxan, tetrahydrofuran and cyclopentyl methyl ether; ether esters such as propylene glycol monomethyl ether acetate and methoxybutyl acetate; Rusuruhokishido, N, aprotic polar solvents such as N- dimethylformamide.

  As the solvent, from the viewpoint of reducing the environmental load, a solvent corresponding to the PRTR method and HAPs regulations, that is, an organic solvent not containing an aromatic compound is preferable. Moreover, the organic solvent classified into the 3rd type organic solvent in the classification | category of the organic solvent by the occupational safety and health law is also preferable. Specifically, ester solvents and ketone solvents that do not fall under the PRTR Law and HAPs regulations; paraffinic solvents and naphthenic solvents classified as third-class organic solvents are preferable.

When using a paraffinic solvent or a naphthenic solvent, it is preferable to use a commercially available weak solvent.
A weak solvent is a type 3 organic solvent in the classification of organic solvents according to the Industrial Safety and Health Act. Specifically, a group consisting of gasoline, coal tar naphtha (including solvent naphtha), petroleum ether, petroleum naphtha, petroleum benzine, turpentine oil, mineral spirit (including mineral thinner, petroleum spirit, white spirit and mineral turpentine) 1 type selected from these, or a mixture of 2 or more types.

Further, the aniline point of the weak solvent is preferably 30 ° C to 70 ° C, more preferably 40 to 60 ° C. The aniline point is measured according to the aniline point test method described in JIS K 2256.
As the weak solvent, mineral spirit is preferable because its flash point is room temperature or higher.

When using a fluorinated polymer (A1) as the room temperature curable fluororesin (A), when using a weak solvent as the solvent (C), the weak solvent is used as a polymerization solvent for the fluorinated polymer (A1). It is preferred to use or superpose a part or all of the polymerization solvent with a weak solvent after polymerization in a polymerization solvent other than the weak solvent.
Further, when the fluoropolymer (A1) is used as the room temperature curable fluororesin (A), the polymerization solvent of the fluoropolymer (A1) and the solvent (C) to be used are different. It is preferable to replace part or all of the polymerization solvent with the solvent (C) after the polymerization of the fluoropolymer (A1).

<Photoinitiator (D)>
When the fluoropolymer (A1) is used as the room temperature curable fluororesin (A), a photoreaction initiator (D) is blended in the coating composition of the present invention.
The photoreaction initiator (D) is preferably a photoreaction initiator that initiates a curing reaction by generating cations with ultraviolet rays. As the photoreaction initiator (D), sulfonium salt-based, iodonium salt-based, phosphonium salt-based, diazonium salt-based, ammonium salt-based and ferrocene-based photoreaction initiators are preferable.

  Examples of the sulfonium salt photoinitiator include bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluoroantimonate, and bis [ 4- (diphenylsulfonio) phenyl] sulfide bistetrafluoroborate, bis [4- (diphenylsulfonio) phenyl] sulfidetetrakis (pentafluorophenyl) borate, diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, diphenyl- 4- (phenylthio) phenylsulfonium hexafluoroantimonate, diphenyl-4- (phenylthio) phenylsulfonium tetrafluoroborate, diphenyl-4- (phenyl) Nylthio) phenylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, bis [4- ( Di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluoroantimony Bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bistetrafluoroborate, [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide tetrakis (pentafluorophenyl) borate, and the like.

  Examples of iodonium salt photoinitiators include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, bis (dodecylphenyl) iodonium hexafluoro. Phosphate, bis (dodecylphenyl) iodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrafluoroborate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4- (1-methylethyl) Phenyl iodonium hexafluorophosphate, 4-methylphenyl-4- 1-methylethyl) phenyliodonium hexafluoroantimonate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrafluoroborate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluoro Phenyl) borate and the like.

  Examples of phosphonium salt photoinitiators include ethyltriphenylphosphonium tetrafluoroborate, ethyltriphenylphosphonium hexafluorophosphate, ethyltriphenylphosphonium hexafluoroantimonate, tetrabutylphosphonium tetrafluoroborate, tetrabutylphosphonium hexafluoro. Examples thereof include phosphate and tetrabutylphosphonium hexafluoroantimonate.

  Examples of the diazonium salt photoinitiator include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, phenyldiazonium tetrakis (pentafluorophenyl) borate, and the like.

  Examples of the ammonium salt photoinitiator include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetrakis (pentafluorophenyl) borate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluorophosphate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluoroantimonate, 1- ( And naphthylmethyl) -2-cyanopyridinium tetrafluoroborate, 1- (naphthylmethyl) -2-cyanopyridinium tetrakis (pentafluorophenyl) borate, and the like.

  Examples of the ferrocene-based photoinitiator include (2,4-cyclopentadiene-1-yl) [(1-methylethyl) benzene] -Fe (II) hexafluorophosphate, (2,4-cyclopentadiene- 1-yl) [(1-methylethyl) benzene] -Fe (II) hexafluoroantimonate, 2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Fe (II) tetrafluoro And borate, 2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Fe (II) tetrakis (pentafluorophenyl) borate, and the like.

  As a commercial item of a photoinitiator (D), Asahi Denka Kogyo Co., Ltd. brand name "SP-150", "SP-152", "SP-170", "SP-172", "CP-" 66 ”,“ CP-77 ”; trade names“ CYRACURE-UVI-6990 ”, [CYRACURE-UVI-6974],“ CYRACURE-UVI-6972 ”manufactured by Union Carbide Corporation; trade names“ CI- ”manufactured by Nippon Soda Co., Ltd. 2855 ”,“ CI-2539 ”,“ CI-2758 ”; trade names“ Sun-Aid SI-60 ”,“ Sun-Aid SI-80 ”,“ Sun-Aid SI-100 ”manufactured by Sanshin Chemical Industry Co., Ltd .; Ciba Specialty Chemicals Product names “Irgacure 261” and “Irgacure 250” manufactured by the company; Product names “RHODROSIL 20” manufactured by Rhodia Japan 4 ”; trade names“ Bis (4-t-butylphenyl) iodonium hexafluorophosphate ”manufactured by Midori Chemical Co., Ltd .; trade names“ CPI-100P ”,“ CPI-101A ”,“ CPI-200K ”manufactured by San Apro; Examples include trade names “ESACURE-1064” and “ESACURE-1187” manufactured by Lamberti; trade names “Kayacure PCI-220” manufactured by Nippon Kayaku Co., Ltd. and the like.

As the photoinitiator (D), a sulfonium salt or iodonium salt-based photoinitiator is more preferable from the viewpoint of curing speed, stability and economy.
As commercial products, trade names “Irgacure 250” manufactured by Ciba Specialty Chemicals; trade names “CPI-100P”, “CPI-101A”, and “CPI-200K” manufactured by Sun Apro are preferable.
A photoinitiator (D) may be used individually by 1 type, and may use 2 or more types together.

<Compound (E)>
When the fluoropolymer (A1) is used as the room temperature curable fluororesin (A), the compound (E) is added to the coating composition of the present invention for the purpose of adjusting the mechanical properties and physical properties of the coating film. Is preferred.
The compound (E) is a compound having one or more reactive functional groups in one molecule that form a chemical bond with the oxetanyl group or substituted oxetanyl group in the fluoropolymer (A1) by a photocation curing reaction.

The reactive functional group possessed by the compound (E) may be any group having a property of reacting with the oxetanyl group or the substituted oxetanyl group in the fluoropolymer (A1). For example, an epoxy group, an oxetanyl group, a vinyl ether group, A vinyl thioether group and a cyclic carbonate group are preferable, and an epoxy group and an oxetane group are more preferable.
The reactive functional group that the compound (E) has may be one type or two or more types.
Moreover, 1 type may be sufficient as the compound (E) contained in the coating composition of this invention, and 2 or more types may be sufficient as it.

[Compound (E-1) having at least one epoxy group in one molecule]
The compound (E-1) having at least one epoxy group in one molecule (hereinafter also referred to as compound (E-1)) is a bisphenol A type epoxy from the viewpoint of resin strength at curing, adhesiveness and the like. Resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol F type epoxy resin, novolac type epoxy resin, hydrogenated novolac type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, alicyclic epoxy Preferred are resins, triphenolmethane type epoxy resins, dicyclopentadiene type epoxy resins, terpene type epoxy resins, bisarylfluorene type epoxy resins, and epoxy group-containing organopolysiloxanes. Commercial products can be used for these.

Moreover, as a compound (E-1), an epoxy-group containing polymer is also preferable. The epoxy group-containing polymer is a polymer having a structural unit based on a monomer containing an ethylenically unsaturated bond and an epoxy group (hereinafter referred to as monomer (e1)).
As the monomer (e1), glycidyl methacrylate, glycidyl acrylate, and 3,4-epoxycyclohexylmethyl methacrylate are preferable.

  In the epoxy group-containing polymer, the monomer (e1) may be a homopolymer, and the monomer (e1) and a monomer other than the monomer (e1) may be a copolymer. May be. The molecular structure of the epoxy group-containing polymer may be linear or may have a branched structure. The epoxy group-containing polymer may be any of a random copolymer, a block copolymer, or a graft copolymer.

The epoxy group-containing polymer can be produced by a known polymerization method. The polymerization method is not particularly limited, and a polymerization method such as radical polymerization or ionic polymerization can be employed. More specifically, polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization using a polymerization initiator can be employed.
Depending on the polymerization method, a large amount of monomer may remain, but in the case where this monomer affects the physical properties of the coating film after curing and application of the coating composition containing the coating composition of the present invention, It is preferable to remove the remaining monomer by a vacuum distillation method, a reprecipitation formation method or the like.

  The Mw of the epoxy group-containing polymer is preferably 3,000 to 100,000, and more preferably 5,000 to 20,000. When the Mw of the epoxy group-containing polymer is not less than the lower limit, a coating film having sufficient hardness is easily obtained. If Mw of an epoxy group containing polymer is below an upper limit, the flatness of a coating film will become favorable.

[Compound (E-2) having one or more oxetanyl groups in one molecule]
The compound (E-2) having at least one oxetanyl group in one molecule (hereinafter referred to as compound (E-2)) has an oxetanyl group or a substituted oxetanyl group and does not have a fluorine atom. A compound is preferable, and a structural unit based on the following compound (2), the following compound (3), the following compound (4), and a monomer having an oxetanyl group or a substituted oxetanyl group (hereinafter referred to as a monomer (e2)). And an oxetanyl group-containing polymer having no fluorine atom is more preferred.

In the formula (2), R ³ is a hydrogen atom or an ethereal alkyl group oxygen atom 1 to 6 carbon atoms that may have a. Z ¹ is a p-valent hydrocarbon group which may have a substituent. p is an integer of 1 to 4.
In formula (3), R ⁴ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have an etheric oxygen atom. Z ² is a q-valent hydrocarbon group which may have a substituent. q is an integer of 1 to 4.
In the formula (4), R ⁵ is a hydrogen atom or an etheric oxygen atom alkyl group of good 1 to 6 carbon atoms have a. R ⁶ is a linear or branched alkyl group having 1 to 6 carbon atoms which may have an etheric oxygen atom. Z ³ is an r-valent hydrocarbon group which may have a substituent. r is an integer of 1-4.

Compound (2):
R ³ in the compound (2) is preferably an alkyl group having 1 to 4 carbon atoms which may have an etheric oxygen atom, and more preferably an alkyl group having 1 to 4 carbon atoms.

Compound (2) can be produced using a known reaction. For example, it can be obtained by an etherification reaction between a hydroxyl compound and 3-alkyl-3-hydroxymethyloxetanes.
Examples of the hydroxyl compound include an aliphatic monoalcohol having an alkyl group having 1 to 6 carbon atoms, an aliphatic glycol having an alkylene group having 2 to 8 carbon atoms, an aromatic alcohol having 2 to 18 carbon atoms, a phenol novolac resin, Examples thereof include polysiloxane having a quaternary structure and a polymerization degree of 2 to 8.
Examples of 3-alkyl-3-hydroxymethyloxetanes include 3-ethyl-3-methoxymethyloxetane.

  Examples of the compound (2) include 1,4-bis (((3-ethyl-3-oxetanyl) methoxy) methyl) benzene and 1,4-bis (((3-ethyl-3-oxetanyl) methoxy) methyl. ) Benzene, 4,4′-bis (((3-ethyl-3-oxetanyl) methoxy) methyl) biphenyl, 3,3 ′, 5,5′-methyl-4,4′-bis (((3-ethyl -3-oxetanyl) methoxy) methyl) biphenyl, 1,4-bis ((3-ethyl-3-oxetanyl) methoxy) benzene, 4,4′-bis ((3-ethyl-3-oxetanyl) methoxy) biphenyl, 3,3 ′, 5,5′-methyl-4,4′-bis ((3-ethyl-3-oxetanyl) methyl) biphenyl and the like.

Compound (3):
R ⁴ in the compound (3) is preferably an alkyl group having 1 to 4 carbon atoms which may have an etheric oxygen atom, and more preferably an alkyl group having 1 to 4 carbon atoms.

Compound (3) can be produced using a known reaction. For example, it can be obtained by an esterification reaction between a carboxyl compound and 3-alkyl-3-hydroxymethyloxetanes.
Examples of the carboxyl compound include adipic acid, terephthalic acid, cyclohexanedicarboxylic acid, trimellitic acid, and pyromellitic acid.

  Examples of the compound (3) include bis ((3-ethyl-3-oxetanyl) methyl) carbonate, bis ((3-ethyl-3-oxetanyl) methyl) adipate, bis ((3-ethyl-3-oxetanyl) And methyl) benzene-1,4-dicarboxylate, bis ((3-ethyl-3-oxetanyl) methyl) cyclohexane-1,4-dicarboxylate, and the like.

Compound (4):
R ⁵ in the compound (4) is preferably an alkyl group having 1 to 4 carbon atoms which may have an etheric oxygen atom, and more preferably an alkyl group having 1 to 4 carbon atoms.
R ⁶ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms which may have an etheric oxygen atom, more preferably a linear or branched alkyl group having 1 to 4 carbon atoms. preferable.

Compound (4) can be produced, for example, using the method described in JP-A-10-25406. Specifically, for example, it can be obtained by a hemiacetal esterification reaction between a carboxyl compound and a 3-alkyl-3-vinyloxymethyloxetane.
Examples of 3-alkyl-3-vinyloxymethyl oxetanes include 3-ethyl-3-vinyloxymethyl oxetane.

Oxetanyl group-containing polymer:
As the monomer (e2), 3-ethyl-3-methacryloylmethyl-oxetane is preferable. Specifically, Ube Industries, Ltd. product name "ETERRNACOLL OXMA" is preferably mentioned.
The oxetanyl group-containing polymer may be a homopolymer of the monomer (e2), or a copolymer of the monomer (e2) and another monomer other than the monomer (e2). May be. Moreover, the molecular structure of the oxetanyl group-containing polymer may be linear or may have a branched structure. The oxetanyl group-containing polymer may be a random copolymer, a block copolymer, or a graft copolymer.

  The oxetanyl group-containing polymer can be produced by a known polymerization method. For example, a method similar to the epoxy group-containing polymer can be adopted except that the monomer (e2) is used instead of the monomer (e1).

  The Mw of the oxetanyl group-containing polymer is preferably 3,000 to 100,000, more preferably 5,000 to 20,000. If Mw of the oxetanyl group-containing polymer is not less than the lower limit value, a coating film having sufficient hardness is easily obtained. If the Mw of the oxetanyl group-containing polymer is not more than the upper limit value, the flatness of the coating film will be good.

  As the compound (E-2), 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] biphenyl is preferable from the viewpoint of compatibility with the fluoropolymer (A1).

[Compound (E-3) having one or more vinyl ether groups in one molecule]
Examples of the compound (E-3) having at least one vinyl ether group in one molecule (hereinafter referred to as compound (E-3)) include divinyl (thio) ethers, trivinyl (thio) ethers, tetravinyl. (Thio) ethers, hexavinyl (thio) ethers and the like can be mentioned.

As a compound (E-3), the following compounds are mentioned, for example.
Trimethylene glycol divinyl ether, 1,4-bisvinyloxymethylcyclohexane, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, polyethylene glycol divinyl ether, 1,4-butanediol divinyl ether Aliphatic divinyl ethers such as 1,5-pentanediol divinyl ether, 1,6-hexanediol divinyl ether, 1,9-nonanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether; Aromatic divinyl ethers such as benzene divinyl ether, bisphenol A divinyl ether, and bisphenol F divinyl ether; trimethylo Aliphatic trivinyl ethers such as ruethane trivinyl ether, trimethylolpropane trivinyl ether, glycerol trivinyl ether; aliphatic tetravinyl ethers such as pentaerythritol tetravinyl ether; aliphatic hexavinyl ethers such as dipentaerythritol hexavinyl ether; Aliphatic divinyl thioethers; aromatic divinyl thioethers; aliphatic trivinyl thioethers; aliphatic tetravinyl thioethers; aliphatic hexavinyl thioethers and the like.
As the compound (E-3), aliphatic divinyl ethers are preferable from the viewpoint of availability and economy.

<Photosensitizer (F)>
The coating composition of the present invention preferably contains a photosensitizer (F) for the purpose of photocuring in a short time under low energy irradiation. The blending of the photosensitizer (F) is capable of maintaining the curing speed even with a small amount of light when the coating composition of the present invention is blended with a pigment or the like so that light is shielded and it is difficult for light to penetrate inside. It is effective.

Examples of the photosensitizer (F) include anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo compounds, diazo compounds, halogen compounds, and photoreductive dyes. .
1 type may be sufficient as the photosensitizer (F) contained in the coating composition of this invention, and 2 or more types may be sufficient as it.

  Specific examples of the photosensitizer (F) include, for example, anthracene compounds; pyrene compounds; benzoin derivatives such as benzoin methyl ether, benzoin isopropyl ether, α, α-dimethoxy-α-phenylacetophenone; benzophenone, 2,4- Benzophenone derivatives such as dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone; thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone Anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone; acridone derivatives such as N-methylacridone and N-butylacridone; α, α-diethoxyacetophenone, benzyl, full Examples include olenone, xanthone, uranyl compound, halogen compound and the like.

In the coating composition of the present invention, when a titanium oxide pigment is blended as a pigment, there is a possibility that ultraviolet light (380 nm or less) is absorbed by the titanium oxide and the coating film becomes poorly cured. Therefore, in this case, it is preferable to use a photosensitizer (F) having a sensitizing ability for light longer than 380 nm in order to avoid poor curing. As the photosensitizer (F) having a sensitizing ability for light longer than 380 nm, an anthracene compound is preferable.
Specific examples include trade names “ANTHRACURE (anthracure) UVS-1331” and “ANTHRACURE (anthracure) UVS-1101” manufactured by Kawasaki Kasei Kogyo Co., Ltd.

<Curing agent (G)>
In particular, when the fluoropolymer (A2) is used as the room temperature curable fluororesin (A), it is preferable to use the curing agent (G).
As a hardening | curing agent (G), the well-known hardening | curing agent which reacts with this crosslinkable group can be used suitably according to the kind of crosslinkable group which a fluoropolymer (A1) and a fluoropolymer (A2) have.

When the crosslinkable group of the room temperature curable fluororesin (A) is a hydroxyl group, an isocyanate curing agent is preferable.
When the crosslinkable group of the room temperature curable fluorine-containing resin (A) is a carboxy group, amine-based curing agents, epoxy-based curing agents, and the like can be given.
When the crosslinkable group of the room temperature curable fluororesin (A) is an amino group, a carboxy group-containing curing agent, an epoxy curing agent, an acid anhydride curing agent, and the like can be given.
When the crosslinkable group of the room temperature curable fluororesin (A) is an epoxy group, a carboxy group-containing curing agent, an acid anhydride curing agent, an amine curing agent, and the like can be given.
When the crosslinkable group of the room temperature curable fluororesin (A) is an alkoxysilyl group, a metal alkoxide is preferable.
When the crosslinkable group of the room temperature curable fluororesin (A) is an isocyanate group, examples thereof include a hydroxyl group-containing curing agent and a carboxy group-containing curing agent.
A hardening | curing agent (G) may be used individually by 1 type, and may use 2 or more types together.

<Curing catalyst (H)>
The coating composition of the present invention may contain a curing catalyst (H) for the purpose of accelerating the curing reaction and imparting good chemical performance and physical performance to the cured coating film. In particular, when curing at a low temperature in a short time, it is preferable to contain a curing catalyst (H).

As the curing catalyst (H), a known curing catalyst can be appropriately used depending on the type of curing reaction, and examples thereof include tin catalysts such as tin octylate, tributyltin dilaurate, and dibutyltin dilaurate.
A hardening catalyst (H) may be used individually by 1 type, and may use 2 or more types together.

<Other components (I)>
The coating composition of the present invention comprises components other than the solvent (C), photoreaction initiator (D), compound (E), photosensitizer (F), curing agent (G) and curing catalyst (H). (I) may be included.
Other components (I) include, for example, silane coupling agents for improving coating film adhesion; 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 cerium oxide; matting agents such as ultrafine synthetic silica; nonionic, cationic or anionic surfactants; leveling agents; pigments A filler, a dispersant, an antifreezing agent, an antifoaming agent, a thickener, and the like.

<Ratio of each component>
When the room temperature curable fluororesin (A) is used, the ratio of the room temperature curable fluororesin (A) in the coating composition of the present invention is preferably 10 to 70% by mass, more preferably 20 to 50% by mass. . If the ratio of the said room temperature curing type fluorine-containing resin (A) is more than a lower limit, it will be easy to form the coating film excellent in mechanical characteristics. If the ratio of the said room temperature curing type fluorine-containing resin (A) is below an upper limit, the coating composition with favorable film forming property will be easy to be obtained.

  When using a resin mixture (B), 10-70 mass% is preferable and, as for the ratio of the resin mixture (B) in the coating composition of this invention, 20-50 mass% is more preferable. If the ratio of the said resin mixture (B) is more than a lower limit, it will be easy to form the coating film excellent in the mechanical characteristic. If the ratio of the said resin mixture (B) is below an upper limit, the coating composition with favorable film forming property will be easy to be obtained.

  10-90 mass% is preferable and, as for the ratio of the fluororesin (B1) with respect to the total mass of a resin mixture (B), 30-70 mass% is more preferable. If the ratio of the said fluororesin (B1) is more than a lower limit, it will be easy to form the coating film excellent in weather resistance and durability. If the ratio of the said fluororesin (B1) is below an upper limit, a coating composition with favorable film forming property will be easy to be obtained.

  10-90 mass% is preferable and, as for the ratio of the acrylic resin (B2) with respect to the total mass of a resin mixture (B), 30-70 mass% is more preferable. If the ratio of the said acrylic resin (B2) is more than a lower limit, the coating composition with favorable film forming property will be easy to be obtained. If the ratio of the said acrylic resin (B2) is below an upper limit, it will be easy to form the coating film excellent in weather resistance and durability.

  The ratio of the solvent (C) in the coating composition of the present invention is appropriately determined in consideration of an appropriate viscosity at the time of coating, a coating method, and the like.

  When the coating composition of the present invention contains a fluorinated polymer (A1) and a photoinitiator (D), the proportion of the photoreaction initiator (D) in the coating composition of the present invention is as follows. 0.05-25 mass parts is preferable with respect to a total of 100 mass parts of A1) and compound (E), and 1-20 mass parts is more preferable. When the ratio of the photoinitiator (D) is at least the lower limit, the sensitivity of the photoinitiator (D) can be sufficiently secured, and curing proceeds sufficiently in a short time even with a small amount of light irradiation energy. If the ratio of the photoinitiator (D) is not more than the upper limit, it is easy to suppress the photoinitiator (D) from remaining and the physical properties of the coating film from being lowered, and it is economically advantageous. .

  When the coating composition of this invention contains a compound (E), the ratio of the compound (E) in the coating composition of this invention is 0.5-10 with respect to 100 mass parts of fluoropolymer (A1). A mass part is preferable and 1-5 mass parts is more preferable. If the ratio of a compound (E) is more than a lower limit, a crosslinking speed will become slow. If the ratio of a compound (E) is below an upper limit, coating-film hardness will fall.

When the coating composition of this invention contains a photosensitizer (F), 0.01-10 mass% is preferable, and, as for the ratio of the photosensitizer (F) in the coating composition of this invention, 1-5 The mass% is more preferable.
The ratio of the other component (G) can be appropriately selected within a range not impairing the effects of the present invention.

  When the curing agent (G) is used in the coating composition of the present invention, the ratio of the room temperature curable fluororesin (A) to the total mass of the room temperature curable fluororesin (A) and the curing agent (G) is 30 to 30%. 90 mass% is preferable, 40-85 mass% is more preferable, 30-80 mass% is further more preferable. If the ratio of the said room temperature curing type fluorine-containing resin (A) is more than a lower limit, it will be easy to form the coating film excellent in the weather resistance. If the ratio of the room temperature curable fluorine-containing resin (A) is not more than the upper limit value, it is easy to suppress the occurrence of cracks in the coating film, and adhesion to the rubber substrate, durability, scratch resistance, and resistance It is easy to form a coating film with good impact.

  When the curing catalyst (H) is blended in the coating composition of the present invention, the ratio of the curing catalyst (H) is based on the total solid content of the coating composition (including the curing agent (G)) at the time of use. 0.00001-10 mass% is preferable. If the ratio of the curing catalyst (H) is not less than the lower limit value, the catalytic effect can be sufficiently obtained. If the ratio of the curing catalyst (H) is not more than the upper limit value, it is easy to suppress the remaining curing catalyst (H) from adversely affecting the coating film, and it is easy to form a coating film having good heat resistance and water resistance.

<Method for producing coating composition>
In the method for producing a coating composition of the present invention, one or both of a room temperature curable fluororesin (A) and a resin mixture (B), a solvent (C), and a photoreaction initiator used as necessary. The order in which (D), compound (E), photosensitizer (F), curing agent (G), curing catalyst (H) and other component (I) are mixed is not particularly limited.
As a mixing method of each component, a method usually used for production of a coating composition can be used. For example, a method using a ball mill, a paint shaker, a sand mill, a jet mill, a rocking mill, an attritor, a three-roll, a kneader and the like can be mentioned.

<Effect>
The coating composition of the present invention includes one or both of a room temperature curable fluororesin (A) and a resin mixture (B) and a solvent (C), so that it is durable without firing. Since the cured coating film excellent in the property and non-adhesiveness can be formed on the heat resistant rubber, the heat deterioration of the heat resistant rubber can be suppressed. Moreover, since it is not necessary to perform a complicated baking process, the formation of the coating film is easy.

≪Goods≫
The article of the present invention has a rubber substrate made of a heat-resistant rubber and a coating film formed on the rubber substrate by the coating composition of the present invention.

<Rubber base material>
The rubber base material is not particularly limited as long as it is made of heat-resistant rubber, and is used for copy rolls, conveyance belts, O-rings, diaphragms, fuel hoses, valve seal chemical plant gaskets used in copying machines, printers, facsimiles, and the like. And engine gaskets.
Rubber base materials include metals such as iron, stainless steel, copper, aluminum and brass; glass products such as glass plates, woven fabrics and nonwoven fabrics of glass fibers; polypropylene, polyoxymethylene, polyimide, polyamideimide, polysulfone A base material such as a molded body of general-purpose resin and heat-resistant resin such as polyethersulfone and polyetheretherketone may be coated with heat-resistant rubber.
The present invention is particularly effective when a copy roll is used as the rubber substrate.

  The heat resistant rubber is not particularly limited, and examples thereof include fluorine rubber and silicone rubber.

<Production method>
Examples of the method for producing an article include a method of forming a coating film by applying the coating composition of the present invention on a rubber substrate and then drying or curing by irradiating with ultraviolet rays. For example, when the fluoropolymer (A1) is used in the coating composition of the present invention, it is cured by irradiation with ultraviolet rays after coating. Moreover, when using a resin mixture (B), it dries after application | coating.
As a coating method, a known coating method can be adopted, and examples thereof include a method using a brush, a roller, a spray, a flow coater, an applicator and the like. What is necessary is just to select suitably the application quantity of a coating composition according to the target film thickness.

In the case of forming a cured coating film by irradiating with ultraviolet rays, the ultraviolet irradiation source is preferably a mercury lamp, a xenon lamp, a carbon arc, a metal halide lamp, or sunlight.
Irradiation conditions of ultraviolet rays are not particularly limited, but it is preferable to irradiate light containing ultraviolet rays in the range of 150 to 450 nm for several seconds or more in air or in an inert gas atmosphere. In particular, when irradiating in air, it is preferable to use a high-pressure mercury lamp.
There is no restriction | limiting in particular in the apparatus used for hardening, Hardening apparatuses, such as a closed-type hardening furnace and a tunnel furnace which can be continuously hardened, are employable. Specifically, an inverter type conveyor “ECS-401GX” manufactured by Eye Graphics Co., Ltd., an ultraviolet irradiation device “UVC-02516S1AA01” manufactured by Ushio Electric Co., Ltd., and the like can be given.

<Effect>
The article of the present invention forms a coating film without firing with a coating composition containing one or both of a room temperature curable fluororesin (A) and a resin mixture (B) and a solvent (C). Therefore, it is excellent in durability and non-adhesiveness, and thermal deterioration of the rubber base material is suppressed.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description. In the examples, “part” means “part by mass”.
[Measurement of hydroxyl value]
The hydroxyl value was measured according to JIS K1557-1 (2007 edition).

[Polymer composition]
The composition of the polymer was analyzed by H ¹ -NMR.

[Example 1]
In an autoclave with a stainless steel stirrer with an internal volume of 2500 mL, 590 g of xylene, 170 g of ethanol, 206 g of ethyl vinyl ether (EVE), 129 g of 4-hydroxybutyl vinyl ether (HBVE), 208 g of cyclohexyl vinyl ether (CHVE), 11 g of calcium carbonate And 3.5 g of t-butyl peroxypivalate (PBPV) were charged, and dissolved oxygen in the liquid was removed by degassing with nitrogen. Next, 660 g of chlorotrifluoroethylene (CTFE) was introduced, the temperature was gradually raised, and the reaction was continued while maintaining the temperature at 65 ° C.
Ten hours later, the reaction was stopped by cooling the autoclave with water. After cooling this reaction liquid to room temperature, the unreacted monomer was purged, and the resulting reaction liquid was filtered through diatomaceous earth to remove solids. Next, part of xylene and ethanol were removed by distillation under reduced pressure to obtain a resin solution (i) containing a fluoropolymer (A2-1).
The composition of the fluoropolymer (A2-1) is: units based on CTFE / units based on EVE / units based on CHVE / constituent units based on HBVE = 50/25/15/10 (mol%). Was 50 mg KOH / g. Moreover, solid content concentration of the resin solution (i) was 60 mass%.

150 g of resin solution (i), dibutyltin dilaurate (diluted ^10-4 times with xylene to give 3 g), hexamethylene diisocyanate (HDI) nurate type polyisocyanate resin (manufactured by Nippon Polyurethane Co., Ltd., trade name: Coronate HX) was added and mixed to obtain a coating composition (X1). The coating composition (X1) was applied to one side of a 1 mm thick silicone rubber sheet so as to have a dry film thickness of 20 μm, and dried at 80 ° C. for 1 hour to obtain a two-layer sheet. The coating composition (X1) can be formed at room temperature, but was dried at 80 ° C. to shorten the drying time.
The results of evaluating the adhesion of the obtained two-layer sheet are shown in Table 1.

[Example 2]
Into an autoclave equipped with a stainless steel stirrer with an internal volume of 300 mL, 55.8 g of 3-ethyl-3-vinyloxymethyloxetane, 95.0 g of xylene, 17.7 g of ethanol, and 1.0 g of potassium carbonate are charged all at once. Then, dissolved oxygen was removed with nitrogen.
Next, 45.8 g of CTFE was introduced and the temperature was gradually raised. After reaching 55 ° C., 0.6 g of a 50% xylene solution of PBPV was introduced into the autoclave over 2 hours, and then for another 15 hours. The reaction was stopped after stirring. After the reaction, potassium carbonate was removed by filtration, and ethanol was distilled off under reduced pressure to obtain a resin solution (ii).
The solid content concentration of the resin solution (ii) was 50% by mass. Moreover, when the infrared absorption spectrum of the resin solution (ii) was measured, since the absorption peak of the oxetanyl group was observed, the production | generation of the fluoropolymer (A2-1) was confirmed. The composition of the fluoropolymer (A2-1) was units based on CTFE / 3 structural units based on 3-ethyl-3-vinyloxymethyloxetane = 50/50 (mol%).

100 g of the fluoropolymer (A2-1) obtained by evaporating and drying the resin solution (ii), 3 g of the trade name “Irgacure 250” (manufactured by Ciba Specialty Chemicals Co., Ltd.) which is a photoreaction initiator (D), 25 g of a trade name “Aron Oxetane OXT-221” (manufactured by Toa Gosei Co., Ltd.) which is a diluent as a solvent (C), and 25 g of activator Celoxide 2021P (manufactured by Daicel Chemical Industries, Ltd.) A coating composition (X2) was obtained.
A coating composition (X2) was applied on one side of a 1 mm thick silicone rubber sheet so as to have a dry film thickness of 20 μm, and then irradiated with UV to obtain a two-layer sheet. For UV irradiation, an inverter-type conveyor “ECS-401GX” manufactured by Eye Graphics Co., Ltd. is used, and a metal halide lamp and a high-pressure mercury lamp are used in combination. Irradiation conditions: 1 kW, conveyor speed: 162 cm / min, number of irradiations: once Carried out.
The results of evaluating the adhesion of the obtained two-layer sheet are shown in Table 1.

[Example 3]
A stainless steel autoclave equipped with a stirrer, a thermometer, and a monomer addition pump was equipped with a heater and a nitrogen gas introducing device, to which 100 parts of water and a vinylidene fluoride copolymer (B1) (a fluororesin (B1)) 100 parts of an aqueous dispersion (latex before coagulation) of vinylidene fluoride / tetrafluoroethylene / hexafluoropropylene copolymer, average particle size of 0.25 μm, trade name: KYNAR 9301, manufactured by Penwort Co., Ltd. Solid content), 0.3 part of sodium persulfate was charged, the gas phase part was replaced with nitrogen gas for 15 minutes, and the temperature was raised to 75 ° C.
Next, 15 parts of n-butyl acrylate, 23 parts of methyl methacrylate, 2 parts of methacrylic acid, 50 parts of water and 0.2 part of sodium alkylbenzene sulfonate as an emulsifier were mixed in a separate container into the autoclave. Added continuously over time. After completion of the addition, the mixture was further aged at 85 to 95 ° C. for 2 hours and then cooled. After adjusting the pH to 8 with aqueous ammonia, it was filtered through a 200 mesh wire mesh to obtain an aqueous dispersion of the resin mixture (B-1).
On the other hand, 100 parts of water was used instead of 100 parts of the aqueous dispersion of Kyner 9301, and similarly, an emulsion of 15 parts of n-butyl acrylate, 23 parts of methyl methacrylate, 2 parts of methacrylic acid, and 50 parts of water was polymerized. The glass transition temperature of the obtained acrylic resin was 36 ° C.

To 100 parts (solid content) of the aqueous dispersion of the resin mixture (B-1), 50 parts of titanium oxide (trade name: Taipei R930, manufactured by Ishihara Sangyo Co., Ltd.) as a filler and polycarboxylic acid sodium salt (as a dispersant) Product name: SN-DISPERSANT5044, manufactured by San Nopco) 2 parts, 1 part of ethylene glycol as anti-freezing agent, preservative (trade name: SN-215, manufactured by San Nopco) 0.05 part, antifoaming agent (trade name: FOAMMASTER) -AP (manufactured by San Nopco) 0.5 parts and 2-amino-2-methyl-1-propanol 2 parts were added and adjusted with water so that the solid content was 60% by mass. Thereafter, hydroxyethyl cellulose (trade name: A-5000, manufactured by Fuji Chemical Co., Ltd.) was used as a thickener and the coating viscosity was adjusted to 4000 cps to obtain a coating composition (X3). For mixing, a disper stirrer was used, and after sufficient mixing, the mixture was transferred to a vacuum deaerator and defoamed.
On the silicone rubber sheet, the coating composition (X3) was applied with an airless spray gun so that the dry film thickness was 200 μm, and dried at 80 ° C. for 1 hour to obtain a two-layer sheet. The coating composition (X3) can be formed at room temperature, but was dried at 80 ° C. to shorten the drying time.
The results of evaluating the adhesion of the obtained two-layer sheet are shown in Table 1.

[Evaluation of adhesion]
After the coating surface was cross-cut (2 mm, 10 × 10 pieces), a peel test with an adhesive tape (manufactured by Nichiban Co., Ltd.) was performed. The adhesion was evaluated according to the following criteria.
○: The number of remaining coating films on the cut surface is 80 or more.
(Triangle | delta): The remaining number of the coating films of a cut surface is 40-79.
X: The number of remaining coating films on the cut surface is 39 or less.

  As shown in Table 1, the coating compositions of Examples 1 and 2 containing a room temperature curable fluorine-containing resin (A) and a solvent (C) are rubber bases made of heat-resistant rubber without firing. A sufficient adhesion film was formed on the silicone rubber. Similarly, the coating composition of Example 3 containing the resin mixture (B) and the solvent (C) also has sufficient adhesion on the silicone rubber, which is a rubber substrate made of heat-resistant rubber, without firing. A coating film was formed.

Claims (5)

  Room-temperature curable fluorine-containing resin (A), fluorine-containing resin (B1) having a structural unit based on vinylidene fluoride (excluding room-temperature-curable fluorine-containing resins) and acrylic having a glass transition temperature of 50 ° C. or lower A heat-resistant rubber coating composition comprising one or both of the resin mixture (B) of the resin (B2) and the solvent (C).   The heat-resistant rubber coating composition according to claim 1, wherein the room temperature curable fluororesin (A) is a photocurable fluoropolymer (A1).   The heat-resistant rubber coating composition according to claim 1 or 2, wherein the solvent (C) contains water.   An article having a rubber base material made of a heat-resistant rubber and a coating film formed on the rubber base material with the heat-resistant rubber coating composition according to any one of claims 1 to 3.   The article of claim 4, wherein the rubber substrate is a copy roll.