JP2016150996A - Coating material composition for release film and release film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material composition for a release film containing a fluorine-containing resin which has good releasability of a cured coating film layer and can obtain excellent adhesiveness between a cured coating film layer and a substrate.SOLUTION: There is provided a coating material composition for a release film which comprises: a fluorine-containing non-block copolymer (A) having a structural unit (A1) based on a fluoroolefin and a structural unit (A2) based on a monomer having a crosslinking group (a hydroxyl group, a carboxyl group, an alkoxysilyl group, an amino group and an isocyanate group); a curing agent (B) selected from an isocyanate-based curing agent (B1), a blocked isocyanate-based curing agent (B2), an amino resin (B3) and a metal alkoxide (B4); and a release agent (C) selected from a fluorine-containing block copolymer (C1) having a hydroxyl group and a fluorine-containing ether compound containing a hydrolyzable silyl group (C2).SELECTED DRAWING: None

Description

  The present invention relates to a release film coating composition and a release film using the same.

  The releasable polyester film can be obtained, for example, by applying an addition reaction type or condensation reaction type silicone compound to one or both sides of a polyester film as a substrate and curing it by heat or ultraviolet irradiation. Features of silicone compounds that have excellent performance such as transparency, dimensional stability, mechanical properties, electrical properties, and chemical resistance of biaxially stretched polyester film represented by polyethylene terephthalate (PET) film, and releasability The releasable polyester film provided with is suitably used for applications such as for process paper.

However, when a silicone compound is used as a release agent, the adhesion or retention to the substrate is not always sufficient, and the substrate and the release agent layer may be peeled off.
Moreover, in the process of a factory production line, since a mold release agent layer once peels and uses after adhering to a product, there exists a possibility that the contamination which the silicone compound in a mold release agent layer transfers to a product may arise. When the silicone compound is transferred to the product, there is a problem that troubles are likely to occur when processing such as plating.
Furthermore, the use of silicone macromonomer improves the problem of easy release from the substrate, but there is a problem of contamination in which trace components (such as low molecular weight silicone) contained in the release agent coating liquid migrate to the product. Newly emerged.

In order to avoid such problems, a release film in which the release agent layer does not contain a silicone compound is desired. For example, a product using a urethane-based or hydrocarbon-based release agent has been proposed, but cannot be used in a hot atmosphere of 160 ° C. or higher because of low heat resistance.
Polymethylpentene film (TPX film) is also known as a heat-resistant release film, but it has a low elastic modulus (no so-called “waist”) and is handled when used in the production line process. There is a drawback that it is difficult.

In recent years, the demand for release films that do not contain silicone compounds has increased in the electronic component industry such as IC components, and as the production technology for electronic component products has become more advanced, the release molds used in the production process. Higher performance has also been demanded for films.
A film or sheet (Teflon (registered trademark)) containing fluorine is available to satisfy such a requirement to some extent.
Patent Documents 1 and 2 propose a method of forming a release agent layer by applying a liquid containing a fluorine-containing resin and a solvent to a base film.

JP 2001-129940 A JP 2004-114620 A

However, the fluorine-containing resin has poor solubility in a solvent, and it is difficult to obtain good adhesion to a base film. For this reason, the conventional fluororesin-containing coating agent has insufficient releasability, and it has been difficult to produce a practical releasable film.
The present invention is a coating composition for a release film containing a fluorine-containing resin, wherein the release property of the cured coating layer is good and excellent adhesion between the cured coating layer and the substrate is obtained. It is an object of the present invention to provide a release film coating composition and a release film using the same.

The gist of the present invention is the following [1] to [5].
[1] A structural unit based on a monomer having a structural unit (A1) based on a fluoroolefin and at least one crosslinkable group selected from the group consisting of a hydroxyl group, a carboxy group, an alkoxysilyl group, an amino group, and an isocyanate group A fluorine-containing non-block copolymer (A) having (A2),
At least one curing agent (B) selected from the group consisting of an isocyanate curing agent (B1), a blocked isocyanate curing agent (B2), an amino resin (B3), and a metal alkoxide (B4), and a hydroxyl group. Release film coating composition comprising at least one release agent (C) selected from the group consisting of a fluorine-containing block copolymer (C1) and a hydrolyzable silyl group-containing fluorine-containing ether compound (C2) Composition.

[2] The release film coating composition according to [1], wherein the release agent (C) is a compound represented by the following formula (C2-A).
CF ₃ O [CF ₂ CF ₂ O] _i CF ₂ C (O) OCH ₂ CH (OC (O) CF ₂ [CF ₂ CF ₂ O] _j OCF ₃ ) CH ₂ CH ₂ Si (OCH ₃ ) ₃ .. (C2-A)
(In the formula, i is an integer of 3 to 200, and j is an integer of 3 to 200.)
[3] The release agent according to [1] or [2], containing 0.01 to 10 parts by mass of the release agent (C) with respect to 100 parts by mass of the fluorine-containing non-block copolymer (A). Type film coating composition.

[4] A release film having a cured coating layer formed by curing the coating composition according to any one of [1] to [3] on one side or both sides of a substrate.
[5] The release film according to [4], wherein the cured coating layer has a water contact angle of 95 to 160 °.

The coating composition for a release film of the present invention contains a fluororesin, has a good release property, and can form a cured coating film layer having excellent adhesion to a substrate.
The release film of the present invention is excellent in the releasability of the cured coating film layer and is excellent in the adhesion between the cured coating film layer and the substrate.

The following definitions of terms apply throughout this specification and the claims.
"Fluorine-containing block copolymer" is composed of a plurality of types of segments having different constituent unit types or different constituent unit compositions in the case of the same type, and at least one segment is a fluorine atom. It means a polymer compound having
The “fluorinated non-block copolymer” is a polymer compound having a fluorine atom in the molecule, and means a copolymer other than the above “fluorinated block copolymer”. For example, an alternating copolymer and a random copolymer are mentioned.

[Fluorine-containing non-block copolymer (A)]
The fluorine-containing non-block copolymer (A) (hereinafter also referred to as a fluorine-containing polymer (A)) in the present invention reacts with the curing agent (B) described later to form a crosslinked structure, and the coating film is cured. It is a component that contributes to
The fluoropolymer (A) includes a structural unit (A1) based on a fluoroolefin (hereinafter also referred to as “structural unit (A1)”) and a structural unit (A2) based on a monomer having a crosslinkable group (hereinafter referred to as “structural unit (A1)”). (Also referred to as “structural unit (A2)”).

<Structural unit (A1)>
The structural unit (A1) is a structural unit based on the fluoroolefin (a1).
The fluoroolefin (a1) 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 fluoro olefin (a1), 2-6 are more preferable.
The number of fluorine atoms in the fluoroolefin (a1) is preferably 2 or more, and more preferably 3-4. When the number of fluorine atoms is 2 or more, the weather resistance of the cured coating film layer is sufficiently improved. In the fluoroolefin (a1), one or more hydrogen atoms not substituted with fluorine atoms may be substituted with chlorine atoms.

As the fluoroolefin (a1), tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride and vinyl fluoride are preferable, and tetrafluoroethylene and chlorotrifluoroethylene are more preferable.
A fluoro olefin may be used individually by 1 type, and may use 2 or more types together.
The structural unit (A1) based on fluoroolefin is a structural unit based on one or more fluoroolefins selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride and vinyl fluoride. It is preferable.

<Structural unit (A2)>
The structural unit (A2) is a structural unit based on a monomer having a crosslinkable group.
The crosslinkable group is preferably at least one selected from the group consisting of a hydroxyl group, a carboxy group, an alkoxysilyl group, an amino group and an isocyanate group, and has both excellent durability, weather resistance, scratch resistance and impact resistance. From the viewpoint of easy handling, a hydroxyl group is more preferable.
As a structural unit (A2), the following structural unit (A2-1) and structural unit (A2-2) are mentioned, for example.
Structural unit (A2-1): a structural unit based on the monomer (a2) having a crosslinkable group.
Structural unit (A2-2): a structural unit having a crosslinkable group formed by functional group conversion of a polymer. That is, the reactive functional group of the structural unit having a reactive functional group in the polymer is reacted with a compound having a crosslinkable group and a functional group capable of reacting with and reacting with the reactive functional group, It is a structural unit formed by a method of converting a reactive functional group into a crosslinkable functional group.

Structural unit (A2-1):
The monomer (a2) forming the structural unit (A2-1) is a polymerizable monomer having a crosslinkable group together with a polymerizable reactive group. The polymerizable reactive group is preferably an ethylenically unsaturated group such as a vinyl group, an allyl group, or a (meth) acryloyl group. That is, the monomer (a2) is preferably a monomer having an ethylenically unsaturated group having a crosslinkable group.
2-10 are preferable and, as for carbon number of a monomer (a2), 3-6 are more preferable.
The monomer (a2) may have an ether bond, an ester bond, a urethane bond, or an amide bond between carbon-carbon bonds other than the double bond of the ethylenically unsaturated bond. The monomer (a2) may be linear or branched.

Examples of the monomer (a2) include the following monomers (a2-1) to (a2-5). A monomer (a2) may be used individually by 1 type, and may use 2 or more types together.
Monomer (a2-1): a hydroxyl group-containing monomer.
Monomer (a2-2): Carboxy group-containing monomer.
Monomer (a2-3): alkoxysilyl group-containing monomer.
Monomer (a2-4): Amino group-containing monomer.
Monomer (a2-5): Isocyanate group-containing monomer.

  Examples of the monomer (a2-1) include hydroxyalkyl vinyl ethers such as 2-hydroxyethyl vinyl ether and 2-hydroxy-2-methylpropyl vinyl ether; ethylene glycol monovinyl ethers such as diethylene glycol monovinyl ether; hydroxyalkyl allyl ethers; Examples include hydroxyalkyl vinyl esters; hydroxyalkyl allyl esters; (meth) acrylic acid hydroxyalkyl esters.

Examples of the monomer (a2-2) include unsaturated carboxylic acids; saturated carboxylic acid vinyl ethers; saturated carboxylic acid allyl ethers; carboxylic acid vinyl ethers; saturated polycarboxylic acid monovinyl esters; Internal acid anhydrides; and unsaturated carboxylic acid monoesters.
Moreover, as a monomer (a2-2), the monomer obtained by making the compound which has an acid anhydride group react with a monomer (a2-1) is mentioned.

As the monomer (a2-3), acrylic acid esters or methacrylic acid esters having an alkoxysilyl group such as CH ₂ ═CHC (O) O (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ; CH ₂ ═CHSi ( Examples include vinyl silanes having an alkoxysilyl group such as OCH ₃ ) ₃ and CH ₂ ═CHSiCH ₃ (OCH ₃ ) ₂ ; vinyl ethers having an alkoxysilyl group such as trimethoxysilylethyl vinyl ether, and the like.

As the monomer (a2-4), amino vinyl ethers represented by CH ₂ ═C—O— (CH ₂ ) _x —NH ₂ (x = 0 to 10); CH ₂ ═CH—O—CO (CH ₂ ) allylamines represented by _{y -NH 2 (y = 1~10)} ; aminomethylstyrene, vinylamine, acrylamide, vinylacetamide, vinylformamide or the like.

  Examples of the monomer (a2-5) include 2-isocyanate ethyl methacrylate, 2-isocyanate ethyl acrylate, 2-isocyanate ethyl ethoxy methacrylate, and 2-isocyanate ethyl vinyl ether.

  As the monomer (a2), the monomer (a2-1) is excellent in the alternating copolymerization property with the fluoroolefin, and the durability, weather resistance, scratch resistance and impact resistance of the formed cured coating layer are improved. ), Monomer (a2-3) is preferable, hydroxyalkyl vinyl ethers and ethylene glycol monovinyl ethers are more preferable, and 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether are more preferable.

Structural unit (A2-2):
A structural unit (A2-2) is a structural unit formed by functional group conversion of a polymer. After a monomer having a reactive functional group is copolymerized with a fluoroolefin or the like to produce a polymer having a reactive functional group, the reactive functional group in the polymer is bonded to the reactive functional group by reacting with the reactive functional group. A polymer having a structural unit (A2-2) is obtained by a method of reacting a compound having a functional group and a crosslinkable group to convert the reactive functional group into a crosslinkable group.

The compound having a functional group capable of reacting with a reactive functional group and being capable of bonding and a crosslinkable group may be a compound that reacts with a reactive functional group of a polymer to newly generate a crosslinkable group. For example, dicarboxylic acid anhydride is a compound that reacts with a hydroxyl group or the like to generate a carboxy group (crosslinkable group).
A polymer having a hydroxyl group can be reacted with a polyvalent carboxylic acid anhydride to convert the hydroxyl group into a carboxy group.

  In the functional group conversion, all of the reactive functional groups in the polymer may be converted, or a part thereof may be converted. For example, a polymer having a hydroxyl group and a carboxy group can be produced by converting a part of the hydroxyl group of the polymer having a hydroxyl group into a carboxy group.

The structural unit (A2) 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 structural unit (A2) contained in the fluoropolymer (A) may be one type or two or more types.

(Structural unit (A3))
In the fluoropolymer (A) in the present invention, in addition to the structural unit (A1) and the structural unit (A2), the structural unit (A3) which is a structural unit other than the structural unit (A1) and the structural unit (A2) It may be optionally contained. The monomer (a3) that can form the structural unit (A3) is a monomer other than the fluoroolefin (a1) and the monomer (a2). As the monomer (a3), a monomer having no crosslinkable group or reactive functional group is preferable.
As the monomer (a3), there can be copolymerized with the fluoroolefin (a1) and the monomer (a2), and a cured coating layer in the release film, and a layer (such as a substrate) on which the cured coating layer is formed. Monomer (a3-1) that exhibits the effect of improving the adhesiveness of is preferable.

As said monomer (a3-1), vinyl ethers, vinyl esters, and allyl ethers are preferable.
Specific examples of the other preferable monomer (a3-1) include vinyl esters such as vinyl acetate, vinyl pivalate and vinyl benzoate; vinyl ethers such as ethyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether and cyclohexyl vinyl ether; Examples include allyl ethers such as allyl ether, butyl allyl ether, and cyclohexyl allyl ether.
As the monomer (a3) other than the monomer (a3-1), olefins such as ethylene and isobutylene are preferable from the viewpoint of improving the solubility in a solvent.
As the monomer (a3), one type may be used alone, or two or more types may be used in combination.

  The fluoropolymer (A) is a polymer containing the structural unit (A1) and the structural unit (A2) as essential structural units, and optionally including the structural unit (A3) as necessary. That is, as the fluoropolymer (A), a polymer comprising the structural unit (A1) and the structural unit (A2), or a polymer comprising the structural unit (A1), the structural unit (A2) and the structural unit (A3). Either or both can be used.

The content of the structural unit (A1) in the fluoropolymer (A) is preferably from 5 to 95 mol% based on the total content of the structural unit (A1) and the structural unit (A2). Mole% is more preferable. If the said content of a structural unit (A1) is 5 mol% or more, the weather resistance of the cured coating film layer formed will improve. If the content of the structural unit (A1) is 95 mol% or less, the compatibility with the curing agent (B) described later is good, and a dense cured coating layer can be formed during curing, The heat resistance, moisture resistance, scratch resistance and impact resistance of the formed cured coating layer are improved.
The content of the structural unit (A2) in the fluoropolymer (A) is preferably from 5 to 95 mol% based on the total content of the structural unit (A1) and the structural unit (A2). Mole% is more preferable. If the content of the structural unit (A2) is 5 mol% or more, the crosslinking density with the curing agent component (B) described later is increased, and a dense cured coating film layer can be formed during curing. The heat resistance, moisture resistance, scratch resistance and impact resistance of the formed cured coating layer are improved. If the said content of a structural unit (A2) is 5 mol% or less, stability of a fluoropolymer (A) will improve and the pot life of a coating composition will improve.
From the viewpoint of weather resistance, the content of the structural unit (A1) in the fluoropolymer (A) is preferably 5 to 95 mol% with respect to the total of all the structural units in the fluoropolymer (A). 10-90 mol% is more preferable, and 15-85 mol% is especially preferable.
The content of the structural unit (A2) in the fluoropolymer (A) improves the heat resistance, moisture resistance, scratch resistance and impact resistance of the cured coating layer by increasing the crosslink density. From a viewpoint, 1-80 mol% is preferable with respect to the sum total of all the structural units in a fluoropolymer (A), 3-70 mol% is more preferable, and 5-60 mol% is especially preferable.

The content of the structural unit (A3) based on the monomer (a3) in the fluoropolymer (A) is preferably 0 to 60 mol% with respect to the total of all the structural units in the fluoropolymer (A). 0 to 50 mol% is more preferable. The structural unit (A3) is an optional component, and the content of the structural unit (A3) being 0 mol% means that the structural unit (A3) is not included. The lower limit of the content when the structural unit (A3-1) based on the monomer (a3-1) is included is more than 0 mol%, and preferably 0.5 mol%. If content of a structural unit (A3) is 60 mol% or less, the adhesiveness with a foundation | substrate will improve, without the weather resistance of a cured coating film layer falling.
The content of each structural unit in the fluoropolymer (A) can be controlled by the amount of each monomer charged and the reaction conditions in the polymerization reaction for obtaining the fluoropolymer (A).

[Curing agent (B)]
A hardening | curing agent (B) plays the role which hardens the application layer which apply | coated the coating composition by reacting with the crosslinkable group of a fluoropolymer (A), and forming a crosslinked structure. As the curing agent (B), a compound having two or more functional groups having reactivity with the crosslinkable group is appropriately selected according to the kind of the crosslinkable group possessed by the fluoropolymer (A).
As the curing agent, an isocyanate curing agent (B1), a blocked isocyanate curing agent (B2), an amino resin (B3), and a metal alkoxide (B4) are preferable. Besides these, known curing agents such as amine curing agents, epoxy curing agents, and acid anhydride curing agents can be used.
When the fluoropolymer (A) has a hydroxyl group, the curing agent (B) is preferably an isocyanate curing agent (B1), a blocked isocyanate curing agent (B2), or an amino resin (B3).
When the fluoropolymer (A) has a carboxy group, examples of the curing agent (B) include amine curing agents and epoxy curing agents.
When the fluorinated polymer (A) has an alkoxysilyl group, the curing agent (B) is preferably a metal alkoxide. When the fluorine-containing polymer (A) has an alkoxysilyl group, the alkoxysilyl group causes a condensation reaction, and therefore a coating composition not containing the curing agent (B) is also preferable.
When the fluoropolymer (A) has an amino group, examples of the curing agent (B) include a carboxy group-containing curing agent, an epoxy curing agent, and an acid anhydride curing agent.
When the fluoropolymer (A) has an isocyanate group, examples of the curing agent (B) include a hydroxyl group-containing curing agent and a carboxy group-containing curing agent.

<Isocyanate curing agent (B1)>
As said isocyanate type hardening | curing agent, a non-yellowing polyisocyanate and a non-yellowing polyisocyanate modified body are mentioned.
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).

Examples of the non-yellowing polyisocyanate-modified product include the following modified products (b1) to (b4).
(B1) Isocyanurate of aliphatic diisocyanate or alicyclic diisocyanate.
(B2) aliphatic diisocyanate or alicyclic diisocyanate modified with polyols or ^{polyamines, -X 2 -C (= O)} -NH- modified product having a structure represented by.
(B3) A modified product having a structure represented by —X ² —C (═O) —NH—, wherein a part of the isocyanate group of an aliphatic diisocyanate or an isocyanurate of an alicyclic diisocyanate is modified with a polyol.
(B4) A modified body comprising a mixture of the modified body (b1) and the modified body (b2).
^{However, -X 2 -C (= O)} X 2 in the -NH- is an organic group derived from a compound having the compound or an amino group having a hydroxyl group. The number of functional groups contained in the compound having a hydroxyl group or the compound having an amino group is preferably 2 to 3.

<Blocked isocyanate curing agent (B2)>
The blocked isocyanate curing agent is a blocked isocyanate curing agent in which the isocyanate group of the isocyanate curing agent (B1) is blocked.
The isocyanate group can be blocked with epsilon caprolactam (E-CAP), methyl ethyl ketone oxime (MEK-OX), methyl isobutyl ketone oxime (MIBK-OX), pyraridine, triazine (TA) or the like.

<Amino resin (B3)>
Examples of the amino resin include melamine resin, guanamine resin, sulfoamide resin, urea resin, aniline resin, and the like. Among these, a melamine resin is preferable because it has a high 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 can be used more preferably.

<Metal alkoxide (B4)>
Examples of the metal and metalloid of the metal alkoxide include Al, Ti, Si, and the like, and a harder cured coating layer can be formed. Durability such as heat resistance, moisture resistance, and water resistance, weather resistance, and scratch resistance. In view of improving the impact resistance, Si is preferable.
The alkoxy group of the metal alkoxide is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably a methoxy group or an ethoxy group, and particularly preferably a methoxy group.

As the metal alkoxide, 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.)
R ² may have a substituent (for example, a halogen atom).
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.

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), 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 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 [O—CH (CH ₃ ) ₂ ] ₃ ) and the like.
Examples of the titanium alkoxide include titanium butoxide (Ti (O—C 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 fluoropolymer (A) is improved and peeling of the cured coating layer from the base material is difficult to occur.

  The coating composition of the present invention may be a composition that does not contain the curing agent (B), and may be a two-component coating composition in which the curing agent (B) is added immediately before forming the cured coating film layer. It is good also as a 1-component type coating composition containing both united body (A) and hardening | curing agent (B). Furthermore, when the fluoropolymer (A) has an alkoxysilyl group, the alkoxysilyl groups cause a condensation reaction, and therefore the curing agent (B) may not be contained.

The content of the fluoropolymer (A) when using the coating composition of the present invention is 10 to 90% by mass with respect to the total content of the fluoropolymer (A) and the curing agent (B). Is preferable, 20-80 mass% is more preferable, and 30-70 mass% is further more preferable.
If the said content of a fluoropolymer (A) is 10 mass% or more, the weather resistance of a cured coating film layer will improve. If the content of the fluoropolymer (A) is 90% by mass or less, it is easy to suppress the occurrence of cracks in the cured coating layer, and the cured coating layer and the layer that forms the cured coating layer Improved adhesion. Moreover, it becomes easy to form the cured coating film layer excellent in durability, scratch resistance and impact resistance.

[Release agent (C)]
The coating composition of the present invention has, as a release agent (C), a fluorine-containing block copolymer (C1) containing a hydroxyl group (hereinafter sometimes simply referred to as a fluorine-containing block copolymer (C1)), and. It contains at least one selected from the group consisting of hydrolyzable silyl group-containing fluorine-containing ether compounds (C2).
<Fluorine-containing block copolymer (C1) containing a hydroxyl group>
The fluorine-containing block copolymer (C1) is preferably composed of two segments having different fluorine atom content ratios (mass basis). Specifically, the segment (α) has a fluorine atom content of 20% by mass or more with respect to all atoms (100% by mass) constituting the segment (α), and the segment (β) is a fluorine atom. Is preferably less than 20% by mass with respect to all atoms (100% by mass) constituting the segment (β).
In addition, each segment may be comprised by the multiple types of small segment from which the composition of the structural unit to contain differs or the composition of a structural unit differs in the case of the same kind.

At least one of the segment (α) and the segment (β) has a structural unit based on a monomer having a hydroxyl group. In the fluorine-containing block copolymer (C1), the segment (β) having a structural unit based on a monomer having a hydroxyl group makes it easy to orient the segment (α) on the surface layer of the cured coating layer. It is preferable in that water, oil repellency and releasability are easily developed.
In addition, as long as the fluorine-containing block copolymer (C1) has a hydroxyl group, it may have a crosslinkable group other than the hydroxyl group such as a carboxy group and an amino group.

The segment (α) is considered to impart excellent water repellency, oil repellency, and releasability to the cured coating layer because the fluorine atom content is in the above range and is high.
The segment (β) is a segment having a smaller fluorine atom content than the segment (α), and is considered to contribute to affinity with the fluorine-containing non-block copolymer (A) and adhesion to the substrate. It is considered that when the affinity and the adhesion to the substrate are excellent, the water repellency, oil repellency, and release properties of the cured coating layer are sufficiently maintained.
Moreover, it is thought that a fluorine-containing block copolymer (C1) has a hydroxyl group and this hydroxyl group reacts with the crosslinkable group contained in a coating composition. When the hydroxyl group of the fluorine-containing block copolymer (C1) is crosslinked, the coating film is sufficiently cured, and the formed cured coating layer has characteristics (water repellency, oil repellency, mold release, etc.). Can be sufficiently maintained. Therefore, the cured coating layer formed using the coating composition containing the fluorine-containing block copolymer (C1) is excellent even when the surface is rubbed or provided in an environment in contact with water. It is considered that the water and oil repellency can be maintained and has excellent releasability.

The segment (α) does not contain a fluorine atom homopolymer, a copolymer composed of two or more fluorine-containing monomers, or at least one fluorine-containing monomer and a fluorine atom. It is preferably composed of a copolymer with at least one non-fluorine monomer.
The segment (β) is a non-fluorine monomer homopolymer, a copolymer composed of two or more non-fluorine monomers, or at least one non-fluorine monomer and a fluorine-containing monomer. It is preferably composed of at least one copolymer.
Segment (α) is composed of a copolymer of a fluorine-containing monomer and a non-fluorine monomer, and segment (β) is composed of a copolymer of a non-fluorine monomer and a fluorine-containing monomer If so, the composition of segments (α) and (β) is different.

The fluorine-containing monomer used for the constitution of the fluorine-containing block copolymer (C1) is, for example, a monomer having a structure represented by the following formula (I) or (II).
R ^F R ⁴ OCOC (R ⁵ ) = CH ₂ (I)
_{^{R F OArCH 2 OCOC (R 5}} ) = CH 2 ... (II)
A fluorine-containing monomer may be used individually by 1 type, or may use 2 or more types together.

In the above formulas (I) and (II), R ^F is a fluoroalkyl group or fluoroalkenyl group having 3 to 21 carbon atoms, preferably a fluoroalkyl group or fluoroalkenyl group having 6 to 10 carbon atoms. When the carbon number is not less than the lower limit of the above range, the performance based on fluorine tends to be exhibited, and when the carbon number is not more than the upper limit of the above range, the chain does not become too long and the polymerization conversion rate is not easily lowered.

R ⁴ is an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 4 carbon atoms. When the carbon number is not more than the upper limit of the above range, the chain does not become too long and the polymerization conversion rate is difficult to decrease.
R ⁵ is hydrogen or a methyl group.
Ar represents a substituent (for example, an alkyl group having 1 to 10 carbon atoms, ester group, ketone group, amino group, amide group, imide group, nitro group, hydroxyl group, carboxylic acid group, thiol group, ether group, etc.). It is an aryl group that may have.

Specific examples of the monomer represented by the above formula (I) include monomers from the following formulas (c-1) to (c-7), and acrylate structure in these monomers is methacrylic. Examples include monomers having an acid ester structure.
F (CF ₂ ) ₆ (CH ₂ ) ₂ OCOCH═CH ₂ (c-1)
F (CF ₂ ) ₈ (CH ₂ ) ₂ OCOCH═CH ₂ (c-2)
F (CF ₂ ) ₁₀ (CH ₂ ) ₂ OCOCH═CH ₂ (c-3)
F (CF ₂ ) ₁₂ (CH ₂ ) ₂ OCOCH═CH ₂ (c-4)
_{H (CF 2) 8 CH 2} OCOCH = CH 2 ... (c-5)
(CF ₃ ) ₂ CF (CF ₂ ) ₆ (CH ₂ ) ₂ OCOCH═CH ₂ (c-6)
(CF ₃ ) ₂ CF (CF ₂ ) ₈ (CH ₂ ) ₂ OCOCH═CH ₂ (c-7)

  Specific examples of the monomer represented by the above formula (II) include monomers of the following formulas (f-1) and (f-2), and an acrylate structure in these monomers is methacrylic acid. Examples include monomers having an ester structure.

As fluorine-containing monomers other than the above, for example, F (CF ₂ ) ₆ CH ₂ OCH═CH ₂ , F (CF ₂ ) ₈ CH ₂ OCH═CH ₂ , F (CF ₂ ) ₁₀ CH ₂ OCH═CH _{2 , F (CF 2) 6 CH} 2 OCF = CF 2, F (CF 2) 8 CH 2 OCF = CF 2, F (CF 2) 10 CH 2 OCF = CF 2, F (CF 2) 6 CH = CH 2 F (CF ₂ ) ₈ CH═CH ₂ , F (CF ₂ ) ₁₀ CH═CH ₂ , F (CF ₂ ) ₆ CF═CF ₂ , F (CF ₂ ) ₈ CF═CF ₂ , F (CF ₂ ) ₁₀ CF = CF ₂ , CH ₂ = CF ₂ , and CF ₂ = CF ₂ monomers.

From the viewpoint of imparting excellent water repellency, oil repellency, and releasability to the cured coating film layer, the monomer used in the structural unit constituting the segment (α) is represented by the above formula (I). It is preferable to use at least one monomer.
Among them, the above formulas (c-1), (c-2), (c-3), (c-4), (c-6), and (c-7) and acrylics in these monomers At least one monomer having an acid ester structure having a methacrylic acid ester structure is preferred.
In addition, when the segment (α) has a structural unit based on a monomer having a hydroxyl group, a monomer having a hydroxyl group is selected from the above-mentioned fluorine-containing monomers or non-fluorine monomers described later. Can be used.

  For segment (α), adjustment of softening temperature of segment (α), introduction of crosslinkable group into segment (α), improvement of affinity for fluorine-containing non-block copolymer (A) and adhesion to substrate For the purpose, etc., it may have a structural unit based on a non-fluorine monomer.

When the segment (α) has a structural unit based on a non-fluorine monomer, the non-fluorine monomer assures affinity with the fluorine-containing non-block copolymer (A) and adhesion to the substrate. On the other hand, from the viewpoint of maintaining excellent water repellency, oil repellency, and releasability, the alkyl (meth) acrylate having an alkyl group having 12 to 20 carbon atoms (hereinafter, also referred to as “long chain (meth) acrylate”). ) Is preferred. These non-fluorine monomers may be used alone or in combination of two or more.
Examples of long chain (meth) acrylates include dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, and (meth) acrylic. Examples include octadecyl acid and behenyl (meth) acrylate, and hexadecyl (meth) acrylate, octadecyl (meth) acrylate and behenyl (meth) acrylate are particularly preferable.

The segment (α) is based on the above formula (c-2) because it can impart excellent water repellency, oil repellency, and releasability to the cured coating film layer, and these characteristics are sustained. A segment consisting of only a unit or a segment consisting of a structural unit based on the above formula (c-2) and a structural unit based on octadecyl (meth) acrylate is preferred.
When the segment (α) is a segment composed of a structural unit based on the above formula (c-2) and a structural unit based on octadecyl (meth) acrylate, the above formula is used for a total of 100% by mass of these structural units. The structural unit based on (c-2) is preferably 99.9 to 20% by mass, and the structural unit based on octadecyl (meth) acrylate is preferably 80 to 0.1% by mass. The structural unit based on 99.5 to 30% by mass and the structural unit based on octadecyl (meth) acrylate are more preferably 70 to 0.5% by mass.

The segment (α) has a fluorine atom content of 20% by mass or more, preferably 25% by mass or more, particularly preferably 30% by mass or more, based on all atoms constituting the segment. Most preferably, it is at least mass%. When it is at least the lower limit of the above range, excellent water repellency, oil repellency and mold release properties are easily imparted to the cured coating film layer.
The content of the structural unit based on the fluorine-containing monomer in the total structural unit (100% by mass) in the segment (α) is preferably 20% by mass or more, more preferably 30% by mass or more, and 35% by mass. % Or more is particularly preferable, and may be 100% by mass.

Non-fluorine monomers include all known monomers capable of radical polymerization that do not have fluorine atoms.
Among them, as the non-fluorine monomer constituting the segment (β), a sufficient polymerization conversion rate can be obtained, and the affinity with the fluorine-containing non-block copolymer (A) and the adhesion to the substrate can be obtained. In view of ensuring that the water-repellent / oil-repellent / releasing properties expressed by the fluorine-containing block copolymer (C1) are not impaired, the compounds of the following formula (III) and other non-fluorine monomers exemplified below: The body is mentioned. A non-fluorine monomer may be used individually by 1 type, or may use 2 or more types together.

R ⁶ OCOCR ⁷ = CH ₂ (III)
In Formula (III), R ⁶ represents an alkyl group having 1 to 22 carbon atoms or an alkyl group having the above substituent, a cycloalkyl group having 3 to 15 carbon atoms, a cycloalkyl group having the above substituent, a phenyl group, or the above substituent. Represents a phenyl group having a group, and R ⁷ represents a hydrogen atom or a methyl group.

Specific examples of the formula (III) include, for example, alkyl (meth) acrylate; hydroxyl group-containing (meth) acrylic acid ester; nitrogen-containing (meth) acrylic acid ester; quaternary ammonium derived from (meth) acrylic acid. And monomers such as salts.
Other non-fluorine monomers include, for example, nitrogen-containing monomers; sulfonic acid group-containing monomers; carboxylic acid group-containing monomers; aromatic vinyl monomers; vinyl ester monomers; Monomer; Itaconic acid ester monomer; Maleimide monomer (monomer having a monovalent group excluding the hydrogen atom bonded to the nitrogen atom of maleimide); Vinylnaphthalene, vinylpyrrolidone, N- Examples thereof include vinyl caprolactam, butadiene, vinyl chloride, vinylidene chloride, vinylidene cyanide, allyl alcohol, (meth) allyl glycidyl ether and the like.

In the fluorinated block copolymer (C1), the segment (β) preferably has a hydroxyl group as described above.
Accordingly, the segment (β) is preferably a hydroxyl group-containing (meth) acrylic acid ester among the non-fluorine monomers, specifically, hydroxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, mono ( (Meth) acrylic acid triethylene glycol, mono (meth) acrylic acid tetraethylene glycol, (meth) acrylic acid polyethylene glycol, (meth) acrylic acid hydroxypropyl, (meth) acrylic acid hydroxypropyl, mono (meth) acrylic acid dipropylene It is preferable to have at least one structural unit based on a hydroxyl group-containing vinyl monomer such as glycol, tripropylene glycol mono (meth) acrylate, tetrapropylene glycol mono (meth) acrylate, or polypropylene glycol (meth) acrylate. .
Among these, at least one selected from hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate is preferable.

  Among the non-fluorine monomers other than the hydroxyl group-containing vinyl monomer, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, N-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, hexadecyl (meth) acrylate, (meth) acrylic Octadecyl acid, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (Meth) acrylamide, (meth) acrylic acid, itaconic acid, (meth) Krill nitrile, vinyl acetate, vinyl benzoate, and styrene.

  Further, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, dodecyl (meth) acrylate, hexadecyl (meth) acrylate, (meth ) Octadecyl acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N- (meth) acryloylmorpholine, (meth) acrylic acid, (meth) acrylonitrile, vinyl acetate, styrene, methoxystyrene, N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide , Diisopropyl fumarate, fu Rusanji tert- butyl, dicyclohexyl fumarate, dibenzyl fumarate, dimethyl itaconate and the like are most preferred.

  As the segment (β), a sufficient polymerization conversion rate is obtained, and the fluorine-containing block copolymer is secured while ensuring the affinity with the fluorine-containing non-block copolymer (A) and the adhesion to the substrate. From the point of not impairing the water repellency, oil repellency and releasability expressed by (C1), a structural unit based on methyl (meth) acrylate, a structural unit based on butyl (meth) acrylate, and (meth) acrylic acid A segment composed of a structural unit based on hydroxyethyl or a segment composed of a structural unit based on hydroxyethyl (meth) acrylate and a structural unit based on octadecyl (meth) acrylate is preferred.

When the segment (β) is a segment composed of a structural unit based on methyl (meth) acrylate, a structural unit based on butyl (meth) acrylate, and a structural unit based on hydroxyethyl (meth) acrylate, these For a total of 100% by mass of the structural units, the structural unit based on methyl (meth) acrylate is 40 to 60% by mass, the structural unit based on butyl (meth) acrylate is 20 to 40% by mass, and (meth) acrylic acid. The structural unit based on hydroxyethyl is preferably 5 to 25% by mass, the structural unit based on methyl (meth) acrylate is 45 to 55% by mass, and the structural unit based on butyl (meth) acrylate is 25 to 35% by mass. %, The structural unit based on hydroxyethyl (meth) acrylate is more preferably 10 to 20% by mass.
When the segment (β) is a segment composed of a structural unit based on hydroxyethyl (meth) acrylate and a structural unit based on octadecyl (meth) acrylate, the total amount of these structural units is 100% by mass ( The structural unit based on hydroxyethyl methacrylate is preferably 0.1 to 50% by mass, the structural unit based on octadecyl (meth) acrylate is preferably 50 to 99.9% by mass, and hydroxyethyl (meth) acrylate. It is more preferable that the structural unit based on is 0.5 to 40% by mass and the structural unit based on octadecyl (meth) acrylate is 60 to 99.5% by mass.

In the segment (β), the fluorine atom content is preferably 10% by mass or less, more preferably 5% by mass or less, and more preferably 0% by mass with respect to all atoms (100% by mass) constituting the segment. %. When the amount is not more than the upper limit of the above range, the affinity for the fluorine-containing non-block copolymer (A) and the adhesion to the substrate are excellent. In addition, water repellency, oil repellency, and releasability are not easily lowered.
The difference between the proportion of fluorine atoms in the total atoms (100% by mass) in the segment (α) and the proportion of fluorine atoms in the total atoms (100% by mass) in the segment (β) is 10% by mass or more. Preferably, it is more preferably 30% by mass or more, and particularly preferably 50% by mass or more. In the segment (α) and the segment (β), the function of the fluorine-containing block copolymer (C1) can be adjusted by changing the type of the structural unit and the proportion of the structural unit.
The proportion of the structural unit based on the non-fluorine monomer in the total structural unit (100% by mass) in the segment (β) is preferably 50% by mass or more, more preferably 65% by mass or more, It is especially preferable that it is 80 mass% or more, and 100 mass% may be sufficient.

The proportion of the structural unit based on the hydroxyl group-containing vinyl monomer in the total structural unit (100% by mass) in the fluorine-containing block copolymer (C1) is preferably 2 to 35% by mass, and 5 to 30% by mass. Is more preferable, and 5 to 10% by mass is particularly preferable. If it is more than the lower limit of the said range, while the coating film fully hardens | cures, the formed cured coating film layer can fully maintain the characteristic. The proportion of the structural unit may exceed the upper limit of the above range, but if it exceeds, the effect of sufficiently curing the coating film and the effect of sufficiently maintaining the characteristics of the cured coating film layer will not be further improved. .
For the same reason, the hydroxyl value of the fluorine-containing block copolymer (C1) is preferably 10 to 100 mgKOH / g, more preferably 15 to 90 mgKOH / g, and particularly preferably 45 to 65 mgKOH / g.

  The proportion of the segment (α) in the fluorine-containing block copolymer (C1) is preferably 20 to 95% by mass, more preferably 30 to 95% by mass, particularly preferably 35 to 90% by mass, and 40 to 60% by mass. Is most preferred. When the segment (α) is at least the lower limit of the above range, sufficient water repellency, oil repellency and mold release properties can be imparted to the cured coating film layer. When the content is below the upper limit of the above range, the affinity to the fluorine-containing non-block copolymer (A) and the adhesion to the substrate are excellent, thereby making the cured coating layer water-repellent, oil-repellent and releasable. Will last long enough.

  The number average molecular weight (Mn) of the fluorine-containing block copolymer (C1) is preferably from 5,000 to 1,000,000, more preferably from 10,000 to 300,000, and particularly preferably from 10,000 to 100,000. preferable. When it is at least the lower limit of the above range, the formed cured coating layer exhibits sufficient performance based on fluorine. A fluorine-containing block copolymer (C1) can be manufactured without a problem as it is below the upper limit of the said range.

  The fluorine-containing block copolymer (C1) can be produced by using polymeric peroxide as a polymerization initiator. The polymer peroxide is a compound having two or more peroxy bonds in one molecule, and one or more of various polymer peroxides described in Japanese Patent Publication No. 05-59942 can be used.

The fluorine-containing block copolymer (C1) can be produced by using a polymer peroxide by an ordinary bulk polymerization method, suspension polymerization method, solution polymerization method, emulsion polymerization method or the like.
In the case of the solution polymerization method, for example, as a first step, polymer peroxide is used as a polymerization initiator, and a non-fluorine monomer including a hydroxyl group-containing vinyl monomer is polymerized in a solution to introduce a peroxy bond into the chain. A peroxy bond-containing non-fluorinated polymer (segment (β)) is obtained. Next, in the second step, when polymerization is carried out by adding a fluorine-containing monomer to the solution obtained in the first step, the peroxy bond in the peroxy bond-containing non-fluorinated polymer is cleaved, and the segment (α ) Is formed. Thereby, a fluorine-containing block copolymer (C1) can be obtained efficiently.

  In the two-stage polymerization as described above, the non-fluorine monomer in the first step is used in the second step, and the fluorine-containing monomer in the second step is used in the first step. (C1) may be obtained.

<Hydrolyzable silyl group-containing fluorine-containing ether compound (C2)>
Hereinafter, the compound represented by the formula (11) is also referred to as a compound (11). Moreover, group represented by Formula (12) is also described as group (12).
The hydrolyzable silyl group-containing fluorine-containing ether compound (C2) is a compound having a structure in which at least one hydrolyzable silyl group is contained in one molecule, and an etheric oxygen atom is inserted between carbon-carbon atoms. is there. The hydrolyzable silyl group is a group that enhances the adhesion between the substrate and the hydrolyzable silyl group-containing fluorine-containing ether compound (C2) by bonding to the substrate, and is a group represented by the formula (13) described later. Is preferred.
The hydrolyzable silyl group-containing fluorine-containing ether compound (C2) is preferably the following compound (11).
X- (Y (Z)) _a -X (11)
In formula (11), X represents an etheric oxygen atom between carbon-carbon atoms in the perfluoro saturated hydrocarbon group represented by the following formula (12) or the perfluoro saturated hydrocarbon group represented by the following formula (12). An inserted perfluoro saturated hydrocarbon group. However, there is no —OCF ₂ O— structure in the group. Two Xs in the formula (11) may be the same or different.

RFO (CF ₂ CF ₂ O) _b (CF ₂ ) _p (CH ₂ ) _o − (12)
However, RF is a group in which an etheric oxygen atom is inserted between carbon-carbon atoms of a C 1-20 perfluoroalkyl group or a C 1-20 perfluoroalkyl group. b is an integer of 3 to 200, p is an integer of 1 or more, and o is an integer of 0 or more.

Examples of the structure of RF in the formula (12) include a linear structure, a branched structure, a ring structure, or a structure having a partial ring structure, a linear structure or a branched structure is preferable, and a linear structure is more preferable. . 1-20 are preferable and, as for carbon number of RF, 1-16 are more preferable.
When RF is a group in which an etheric oxygen atom is inserted between carbon-carbon atoms of a C 1-20 perfluoroalkyl group, the number of inserted oxygen atoms is preferably 1-7, and 1-4 Is more preferable. The position where the oxygen atom is inserted is in a ring or in a straight chain, and there are at least two carbon atoms contained between oxygen atoms.

Specific examples of RF include the following groups.
CF ₃ (CF ₂ ) _l − (l represents an integer of 0 to 15)
For example, a trifluoromethyl group, a pentafluoroethyl group and the like can be mentioned. From the viewpoint of water and oil repellency, a trifluoromethyl group is preferable, and from the viewpoint of the yield in liquid phase direct fluorination, which is one of the production steps. Is preferably a pentafluoroethyl group.
Accordingly, examples of the group (12) include the following.
_{CF 3 -O- (CF 2 CF 2} O) b - ··· (X-1)
_{CF 3 CF 2 -O- (CF 2} CF 2 O) b - ··· (X-2)
CF ₃ (CF ₂ ) ₂ —O— (CF ₂ CF ₂ O) _b — (X-3)
CF ₃ (CF ₂ ) ₅ —O— (CF ₂ CF ₂ O) _b — (X-4)

The group (12) is preferably X-1 or X-2 from the viewpoint of water / oil repellency, and more preferably X-2 from the viewpoint of ease of synthesis.
Moreover, the following is mentioned as a preferable example of RF which has a ring structure.
_{CyF- (CF 2) m -,} (CyF represents a perfluorocyclohexyl group, m is an integer of 0 to 15.)
AdF— (CF ₂ ) _n — (AdF represents a group in which one of the fluorine atoms of perfluoroadamantane is a bond, and n represents an integer of 0 to 15).

In the formula (12), b represents the number of — (CF ₂ CF ₂ O) — units and is an integer of 3 to 200, preferably an integer of 3 to 100, more preferably an integer of 3 to 70, An integer of 50 is particularly preferred.
p is - (CF ₂₎ - the number of units is an integer of 1 to 10, preferably an integer of 1 to 5, more preferably 1 to 2 integer. The number of units is determined by the synthesis method used.
o represents the number of — (CH ₂ ) — units, and is an integer of 0 to 10, preferably an integer of 0 to 5, and more preferably an integer of 0 to 2. The number of units is also determined by the synthesis method used.

In formula (11), Y is a connecting part of X and Z, and is an organic group having two or more carbon atoms, preferably an organic group having 2 to 20 carbon atoms, more preferably an organic group having 2 to 10 carbon atoms. Represents.
The portion represented by Y has a structure having sufficient strength in use, and not only connects X and Z, but also when a compound (11) is diluted in an actual coating process and used in particular, a hydrocarbon solvent. It has a great influence on solubility.
The organic group having two or more carbon atoms as Y is an organic group composed of two or more carbon atoms and other atoms such as a hydrogen atom, an oxygen atom, a nitrogen atom, and a fluorine atom. It is a saturated hydrocarbon group.
Moreover, the organic group as Y may contain an ether bond, an ester bond, and a urethane bond.
Y can be freely selected based on the use and availability of raw materials.

When Y is a skeleton having only a carbon bond and X and Z are linked, it is preferable that there is no carbon atom having a fluorine atom within the β-position of the Si element, that is, within 2 from the Si. This is because a decomposition reaction proceeds at a relatively low temperature when a fluorine atom is present in the β-position, and it has been reported in past literatures.
Specific examples of the structure of Y include those corresponding to the site connecting two X and Z in the example of the following compound (11).

In the formula (11), Z is a hydrolyzable silyl group that bonds the substrate and the compound (11), and is represented by the following formula (13).
-Si- (Z ₁ ) _c (Z ₂ ) _(3-c) (13)
Here, Z ₁ represents a group capable of condensation by elimination, Z ₂ represents a hydrogen atom or an inert monovalent organic group, and c represents an integer of 1 to 3.

Z ₁ is an isocyanate group, a halogen atom, an alkoxy group or the like, and examples thereof include an isocyanate group, a chlorine atom, a methoxy group, and an ethoxy group. In general, alkoxy groups are preferred because of outgassing problems during storage and storage stability, ethoxy groups when long-term stability is required, and methoxy groups when a short aging time is required during coating. Is particularly preferred.

Z ₂ is a hydrogen atom or an inert monovalent organic group. Here, the “inert monovalent organic group” as Z ₂ is a monovalent organic group that does not cause condensation, whereas Z ₁ is a group that can be condensed by elimination. means. Specific examples of Z ₂ include a hydrogen atom and a methyl group. Z ₂ can be appropriately selected according to the application and the article to be coated, like Z ₁ .

In Formula (11), a represents the number of — (Y (Z)) — units, an integer of 1 to 10, an integer of 1 to 5 is more preferable, and an integer of 1 to 3 is particularly preferable. Industrially, a mixture of different a is easily available.
a is an integer greater than or equal to 1, the integer of 1-100 is preferable, the integer of 1-10 is more preferable from the point of function expression, and the integer of 1-5 is especially preferable.

There is no structural unit represented by — (OCF ₂ O) — in compound (11). - _(OCF 2 O) - and the unit is not present compounds, in the structure of the compound of formula (11) - a unit does not actually exist compounds - _(OCF 2 O). Further, even if the unit is present, it means that the unit is present in an amount below the detection limit of a normal analysis method (such as ¹⁹ F-NMR).

  Compound (11) can be synthesized by a known method using, for example, a moiety represented by X, that is, compound (12) containing group (12) as a starting material. Specifically, it can be produced by the method described in Japanese Patent No. 4857528.

As the compound (11), a compound represented by the following formula (C2-A) is particularly preferable from the viewpoint of crosslinkability.
CF ₃ O [CF ₂ CF ₂ O] _i CF ₂ C (O) OCH ₂ CH (OC (O) CF ₂ [CF ₂ CF ₂ O] _j OCF ₃ ) CH ₂ CH ₂ Si (OCH ₃ ) ₃ ..・ (C2-A)
(In the formula, i is an integer of 3 to 200, and j is an integer of 3 to 200.)

In the coating composition of the present invention, the content of the release agent (C) is preferably 0.01 to 10 parts by mass, and 2 to 9 parts by mass with respect to 100 parts by mass of the fluoropolymer (A). More preferred is 4-8 parts by mass. The effect by containing a mold release agent (C) is fully acquired as it is 0.01 mass part or more, and it is based on the hydroxyl group or hydrolyzable silyl group of a mold release agent (C) as it is 10 mass parts or less. An appropriate crosslinking reaction is easily obtained (the self-crosslinking of the hydrolyzable silyl group is easily suppressed), and the desired effect is sufficiently obtained.
The coating composition of the present invention is selected from a fluorine-containing block copolymer (C1) and a hydrolyzable silyl group-containing fluorine-containing ether compound (C2) as a release agent (C) to be combined with the fluorine-containing polymer (A). By using at least one selected from the above, a cured coating layer having higher hardness and superior durability such as heat resistance and water resistance, weather resistance, scratch resistance and impact resistance can be obtained.

[Curing catalyst (D)]
Further, the coating composition of the present invention may contain a curing catalyst (D) for the purpose of accelerating the curing reaction and imparting good chemical performance and physical performance to the cured coating film layer that is a cured product. In particular, when curing at a low temperature in a short time, it is preferable to contain a curing catalyst (D). Examples of the curing catalyst (D) include the following curing catalysts (D-1), (D-2), and (D-3).
Curing catalyst (D-1): A curing catalyst used for a crosslinking reaction between a fluorine-containing polymer containing a hydroxyl group and an isocyanate curing agent or a blocked isocyanate curing agent.
Curing catalyst (D-2): a curing catalyst used for a crosslinking reaction between a fluoropolymer containing at least one of an alkoxysilyl group and a hydroxyl group and a metal alkoxide.
Curing catalyst (D-3): a curing catalyst used for a crosslinking reaction between a fluoropolymer containing a hydroxyl group and an amino resin.

As the curing catalyst (D-1), tin catalysts such as tin octylate, tributyltin dilaurate, and dibutyltin dilaurate are preferable.
As the curing catalyst (D-2), 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; acidic phosphoric acid ester and amine Amine adducts such as addition reaction products, addition reaction products of carboxylic acid compounds and amines; metal esters such as tin octylate and dibutyltin dilaurate; tris (acetylacetonate) aluminum, tetrakis (acetylacetonate) zirconium, etc. And metal alkoxides such as aluminum isopropoxide and titanium butoxide. Among these, acidic phosphates are preferable from the viewpoint of curability and the smoothness of the formed cured coating layer, and carbon is preferable from the viewpoints of curability, smoothness of the formed cured coating layer, water resistance, and the like. 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 (D-3), 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 (D) may be used individually by 1 type, and may use 2 or more types together.

  The content of the curing catalyst (D) is preferably 0.00001 to 10% by mass with respect to the total solid content of the coating composition (including the curing agent (B) and the release agent (C)) at the time of use. . If the content of the curing catalyst (D) is 0.00001% by mass or more, the catalytic effect can be sufficiently obtained. If content of a curing catalyst (D) is 10 mass% or less, the remaining curing catalyst (D) will not affect a cured coating film layer, and heat resistance and water resistance will improve.

[Resin (E)]
The coating composition of the present invention may contain another resin (E) that does not correspond to either the fluoropolymer (A) or the release agent (C).
Examples of the resin (E) 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 resins and other non-fluorine resins, fluorine-containing resins Examples thereof include a fluorine-containing resin other than the polymer (A). The resin (E) may be a resin having a crosslinkable group and being cured by being crosslinked by the curing agent (B).
When resin (E) is mix | blended with the coating composition of this invention, 1-200 mass parts is preferable with respect to 100 mass parts of fluoropolymer (A).

[Component (F)]
The coating composition of the present invention includes a fluoropolymer (A), a curing agent (B), a release agent (C), a curing catalyst (D), a resin (E), a solvent (G) and a pigment (described later). A component (F) other than H) may be contained.
Component (F) includes hydrolyzable silyl agent for improving adhesion of cured coating layer; light stabilizer such as hindered amine light stabilizer; benzophenone compound, benzotriazole compound, triazine compound, cyanoacrylate UV absorbers such as organic compounds; inorganic UV absorbers such as titanium oxide, zinc oxide, and cerium oxide; matting agents such as ultrafine synthetic silica; nonionic, cationic, or anionic surfactants A leveling agent and the like.
Content of a component (F) can be suitably selected in the range which does not impair the effect of this invention.

[Solvent (G)]
The coating composition of this invention is a composition containing each said component which forms a cured coating film layer. Furthermore, in order to apply the coating composition of this invention, the component which is not a component which forms a cured coating film layer can also be used with the coating composition of this invention. In particular, in order to apply the coating composition, it is preferable to use the solvent (G) mixed in the coating composition. By applying a composition containing the solvent (G) to form a coating film of the coating composition containing the solvent, and then removing the solvent (G), a cured coating film layer of the coating composition is formed.
As the solvent (G) for applying the coating composition of the present invention, conventionally used solvents such as toluene, xylene, methyl ethyl ketone, butyl acetate and the like can be used. Therefore, a weak solvent is preferable.
The weak solvent is preferably a weak solvent species that can be used in the polymerization of the fluorinated polymer (A) or solvent substitution, and more preferably mineral spirits and mineral terpenes.
The content of the solvent (G) in the coating composition containing the solvent (G) is appropriately determined in consideration of the solubility of the fluoropolymer (A), the appropriate viscosity when applied as a coating, the coating method, and the like. Is done.

[Pigment (H)]
The coating composition of the present invention may contain a pigment component (C) for the purpose of rust prevention, coloring, reinforcement and the like of the cured coating film layer.
The pigment component (H) is preferably at least one pigment 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 layer. 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 layer and increasing the thickness of the cured coating film layer. Examples of extender pigments include talc, barium sulfate, mica, and calcium carbonate.

  The content of the pigment (H) in the coating composition of the present invention is from 50 to the total solid content of the coating composition (including the curing agent (B) and the release agent (C)) at the time of use. 500 mass% is preferable and 100-400 mass% is more preferable. When the content of the pigment (H) is 50% by mass or more, the function of the pigment (H) is easily obtained. If content of a pigment (H) is 500 mass% or less, it will become difficult for a cured coating film layer to be cracked or damaged by impacts, such as sand, and the weather resistance of a cured coating film layer will improve.

If the coating composition of this invention demonstrated above is used, the cured coating film layer which contains a fluorine atom and has a crosslinked structure can be formed as a cured coating film layer in a film for mold release. Since the cured coating layer has a cross-linked structure and is a hard coating layer, it has excellent scratch resistance and impact resistance. In addition to improving the weather resistance by containing fluorine atoms, the cured coating film layer is a hard coating film having a crosslinked structure, so that the degree of expansion and contraction due to heat is reduced, moisture absorption, water absorption The heat resistance, water resistance, and moisture resistance are further enhanced.
In particular, by using a fluorine-containing block copolymer (C1) containing a hydroxyl group and / or a hydrolyzable silyl group-containing fluorine-containing ether compound (C2) as the release agent (C), the substrate and the cured coating can be obtained. Good adhesion of the film layer is obtained. The reason is that the release agent (C) has a hydroxyl group or a hydrolyzable silyl group, so that a crosslinked structure is generated in the coating film, and the functional group present on the substrate surface and the hydroxyl group or hydrolyzable group are present. It is considered that the adhesion is improved by the bond with the silyl group.

<Release film>
The release film of the present invention is obtained by laminating a cured coating layer of the coating composition of the present invention on one side or both sides of a substrate.
Such a mold release film is obtained by applying the coating composition of the present invention to one or both sides of a substrate by a known method, and drying and curing.
The substrate is preferably a polyester film in terms of transparency, dimensional stability, mechanical properties, electrical properties, and chemical resistance. Examples of the polyester film include a polyethylene terephthalate (PET) film. Although the thickness of a base material is not specifically limited, For example, in the case of process paper, about 12-342 micrometers is preferable at the point of handleability.
Although the thickness of a cured coating film layer is not specifically limited, 20-60 micrometers is preferable at a weather-resistant point, and 40-50 micrometers is more preferable.

In the release film of the present invention, a fluorine-containing resin is used as a film forming component of the cured coating layer, and the release property of the cured coating layer is good, and the adhesion between the cured coating layer and the substrate is good. Excellent in properties.
According to the present invention, a group of films and sheets having a cured coating film layer having excellent durability such as heat resistance and water resistance and excellent weather resistance, scratch resistance and impact resistance, and containing fluorine ( A releasable film having performance equivalent to that of Teflon (registered trademark) and having excellent properties such as transparency, antifouling property, water repellency and oil repellency can be realized.
Specifically, a release film having a water contact angle of the cured coating layer of 95 to 160 ° is obtained.

Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples. The following evaluation methods were used.
[Evaluation method]
(1) Peelability test On the release agent layer of the release film, an adhesive tape having a width of 50 mm (manufactured by Sekisui Chemical Co., Ltd., trade name “adhesive tape 252”) was pressure-bonded with a rubber roll. In a constant temperature room at 23 ° C., the peeling resistance when peeling the adhesive tape with a tensile tester (peeling angle 180 °, peeling speed 300 mm / min) was measured, and the value was taken as the peeling force (unit) : N / 50 mm).
Separately, an adhesive tape having the same width of 50 mm as described above was pressure-bonded onto the release film with a rubber roll. Next, with a load of 20 g / cm ² applied, it was allowed to stand in an atmosphere at 70 ° C. for 20 hours and then returned to room temperature, and the peel force (unit: N / 50 mm) was determined by the same method as described above. The value was determined as the peel strength after heating (unit: N / 50 mm). The smaller the peel strength, the easier it is to peel and the better the releasability.

(2) Residual Adhesion Rate Test After the pressure-sensitive adhesive tape is attached to a stainless steel plate (SUS304, the same applies hereinafter), the force when peeling it is defined as fo.
In the peeling test (before or after heating), the adhesive tape peeled off from the release film is attached to a stainless steel plate, and a tensile tester (peeling angle 180 °, peeling rate 200 mm / min constant speed) in a constant temperature room at 23 ° C. Then, the peel resistance when the adhesive tape is peeled is measured, and the value is defined as the residual adhesive force f. The residual adhesion rate is a value obtained by the following equation. The larger this value is, the better the release property of the release film.
Residual adhesion rate (unit:%) = (f / fo) × 100

(3) Accelerated weather resistance test Using an accelerated weathering tester (Q-PANEL LAB PRODUCTS, model: QUV / SE), the cured coating layer was peeled off from the substrate after 5000 hours exposure and compared with the initial stage. The presence or absence of was observed. The weather resistance was evaluated according to the following criteria.
“◯”: No peeling of the cured coating film layer was observed.
"X": Peeling of the cured coating film layer was observed.

(4) Actual exposure test The presence or absence of peeling of the cured coating film layer from the base material was observed by comparing between just before installation and one year after outdoor in Naha, Okinawa Prefecture. The weather resistance was evaluated according to the following criteria.
“◯”: No peeling of the cured coating film layer was observed.
"X": Peeling of the cured coating film layer was observed.

<Production of fluoropolymer (A)>
[Example 1 (Production Example)]
In a pressure resistant reactor with a stainless steel stirrer having an internal volume of 2500 mL, 590 g of xylene as a solvent and 170 g of ethanol, 129 g of 4-hydroxybutyl vinyl ether (HBVE) as a monomer (a2-1), monomer (a3- 1) 206 g of ethyl vinyl ether (EVE) and 208 g of cyclohexyl vinyl ether (CHVE), 11 g of calcium carbonate as a pigment, and 3.5 g of t-butyl peroxypivalate (PBPV) as a radical polymerization initiator The dissolved oxygen in the liquid was removed by degassing with nitrogen.
Next, 660 g of chlorotrifluoroethylene (CTFE) as the fluoroolefin (a1) was introduced, the temperature was gradually raised, and the reaction was continued while maintaining the temperature at 65 ° C. After reacting for 10 hours, the reaction was stopped by cooling the reactor with water. After cooling the reaction solution to room temperature, unreacted monomers were purged, and the resulting reaction solution was filtered through diatomaceous earth to remove solids. Next, a part of xylene and ethanol were removed by distillation under reduced pressure to obtain a xylene solution (non-volatile content 60%) of the fluorine-containing non-blocking polymer (A) containing a hydroxyl group.
In the obtained fluorine-containing non-block polymer (A), the molar ratio of CTFE / HBVE / EVE / CHVE is 50/10/25/15.

<Preparation of coating composition>
[Example 2 (Example)]
To 83 g of the xylene solution (non-volatile content 60%) of the fluorine-containing non-block polymer (A) obtained in Example 1, 200 g of titanium oxide (trade name “D-918” manufactured by Sakai Chemical Co., Ltd.) as a pigment, 43 g of xylene as a solvent and 43 g of butyl acetate were added, and 369 g of glass beads having a diameter of 1 mm were further added, followed by stirring for 2 hours in a paint shaker. After stirring, filtration was performed to remove the glass beads to obtain a pigment composition.
Next, to 100 g of the pigment composition, 150 g of the xylene solution (nonvolatile content 60%) of the fluorine-containing non-blocking polymer (A) obtained in Example 1 and the HDI nurate type of the curing agent (B1) are used. 18.5 g of polyisocyanate resin (trade name “Coronate HX” manufactured by Nippon Polyurethane Co., Ltd.) and dibutyltin dilaurate as a curing catalyst (D-1) (diluted 4 to 10 times with xylene to 3 g) Further, 2.62 g of the compound represented by the following formula (C2-A), which is a hydrolyzable silyl group-containing fluorine-containing ether compound (C2), was added and mixed to obtain a coating composition I.
CF ₃ O [CF ₂ CF ₂ O] _i CF ₂ C (O) OCH ₂ CH (OC (O) CF ₂ [CF ₂ CF ₂ O] _j OCF ₃ ) CH ₂ CH ₂ Si (OCH ₃ ) ₃ ..・ (C2-A)
(In the formula, i is an integer of 5 to 50, and j is an integer of 5 to 50.)

[Example 3 (Example)]
To 16.7 g of the xylene solution of the fluorine-containing non-block polymer (A) obtained in Example 1, 40.0 g of titanium oxide, 20.0 g of xylene, and 23.2 g of butyl acetate were added. Furthermore, 100.0 g of glass beads having a diameter of 1 mm were added and stirred for 2 hours with a paint shaker. After stirring, filtration was performed to remove the glass beads to obtain a pigment composition.
Next, 31.4 g of the pigment composition was mixed with 44.0 g of the xylene solution of the fluorine-containing nonblocking polymer (A) obtained in Example 1 and a blocked isocyanate resin (Sumitomo) as a curing agent (B2). 10.2 g of Bayer Urethane Co., Ltd., trade name “Sumijour BL3175”), 12.6 g of butyl acetate, and dibutyltin dilaurate as a curing catalyst (D-1) (diluted 4 to 10 times with xylene) 1.8 g.) And a fluorine-containing release agent (AGC Seimi Chemical Co., Ltd., trade name “MR EF-6521-AL”, isopropanol) which is a fluorine-containing block copolymer (C1) containing a hydroxyl group. 2.84 g of the fluorine-containing release agent contained) was further added and mixed to obtain a coating composition II.

<Manufacture and evaluation of release film>
[Example 4 (Example)]
The coating composition I obtained in Example 2 was coated on a polyethylene terephthalate film having a thickness of 20 μm as a substrate using a bar coater. After heat-treating at 80 ° C. for 30 minutes, after cooling, the cured coating layer having a thickness of about 10 μm was formed by curing in a thermostatic chamber at 25 ° C. for 1 week to obtain a release film.
The obtained release film was evaluated by performing the tests (1) to (4) above. The results are shown in Tables 1 and 2 (hereinafter the same).

[Example 5 (Example)]
The coating composition I obtained in Example 2 was coated on a polyethylene terephthalate film having a thickness of 30 μm as a substrate using a bar coater. A heat treatment was performed at 100 ° C. for 45 minutes to form a cured coating film layer having a thickness of about 15 μm to obtain a release film.
[Example 6 (Example)]
In Example 5, instead of the coating composition I, the coating composition II obtained in Example 3 was used. Otherwise, a release film was produced in the same manner as in Example 5.

[Example 7 (comparative example)]
A coating composition containing a fluorine-containing random copolymer not containing a release agent (C) was coated on a polyethylene terephthalate film having a thickness of 30 μm as a substrate using a bar coater. A heat treatment was performed at 100 ° C. for 45 minutes to form a cured coating film layer having a thickness of about 15 μm to obtain a release film.
The coating composition containing a fluorine-containing random copolymer (manufactured by Daikin, product number “TC-7609M1”) containing no release agent, used in this example, is represented by (C2-A) in Example 2. It was prepared in the same manner as in Example 2 except that the compound was not blended.

As shown in the results of Tables 1 and 2, the cured coating film layers of Examples 4 to 6 formed using the release film coating composition of the present invention are excellent in releasability and adhesiveness to the substrate. And it can be used stably for a long period of time. In addition, the release film produced using the coating composition of the present invention has excellent weather resistance, and as shown in Table 2, peeling of the cured coating film layer also occurs in severe weather resistance tests and actual exposure tests. It was not confirmed.
On the other hand, Example 7 is a comparative example, and although the cured coating layer is formed of a resin containing fluorine atoms, the release agent (C) is not included. As shown in Table 1, the release film of Example 7 was inferior in the release property of the cured coating film layer as compared with Examples 4 to 6, and as shown in Table 2, after the accelerated weather resistance test and the actual exposure test Then, peeling of the cured coating film layer was observed.

Claims (5)

Structural unit (A2) based on a monomer having a structural unit (A1) based on a fluoroolefin and at least one crosslinkable group selected from the group consisting of a hydroxyl group, a carboxy group, an alkoxysilyl group, an amino group, and an isocyanate group A fluorine-containing non-block copolymer (A) having
At least one curing agent (B) selected from the group consisting of an isocyanate curing agent (B1), a blocked isocyanate curing agent (B2), an amino resin (B3), and a metal alkoxide (B4), and a hydroxyl group. Release film coating composition comprising at least one release agent (C) selected from the group consisting of a fluorine-containing block copolymer (C1) and a hydrolyzable silyl group-containing fluorine-containing ether compound (C2) Composition. The coating composition for a release film according to claim 1, wherein the release agent (C) is a compound represented by the following formula (C2-A).
CF ₃ O [CF ₂ CF ₂ O] _i CF ₂ C (O) OCH ₂ CH (OC (O) CF ₂ [CF ₂ CF ₂ O] _j OCF ₃ ) CH ₂ CH ₂ Si (OCH ₃ ) ₃ ..・ (C2-A)
(In the formula, i is an integer of 3 to 200, and j is an integer of 3 to 200.)   The coating composition for a release film according to claim 1 or 2, comprising 0.01 to 10 parts by mass of the release agent (C) with respect to 100 parts by mass of the fluorine-containing non-block copolymer (A). object.   The release film which has the cured coating film layer which hardens the coating composition as described in any one of Claims 1-3 on the single side | surface or both surfaces of a base material.   The release film of Claim 4 whose water contact angle of the said cured coating film layer is 95-160 degrees.