JPS63199211A - Composition for coating compound - Google Patents

Abstract

PURPOSE:To obtain the titled inexpensive composition providing a film of coating having excellent weather resistance, water repellency, oil repellency, stain resistance, surface gloss, etc., consisting of a fluorine-containing polymer having a crosslinkable part, an acrylic copolymer having compatibility with the fluorine- containing polymer and a polyfluorocarbon chain-containing compound. CONSTITUTION:(A) A fluorine-containing polymer having a crosslinkable part is blended with (B) an acrylic copolymer having compatibility with the component A and (C) 0.5-30wt.% based on sum of the components A and B of a polyfluorocarbon chain-containing compound (preferably compound shown by the formula, etc.) to give the aimed composition. Chlorotrifluoroethylene/ethyl vinyl ether/hydroxybutyl vinyl ether copolymer, etc., are preferable as the component A and n-butyl methacrylate/2-hydroxyethyl methacrylate/methacrylic acid copolymer, etc., are preferable as the component B. A curing agent is preferably used in curing of the composition.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a coating composition, and more specifically, to a coating composition that has excellent weather resistance and exhibits excellent water and oil repellency and stain resistance over a long period of time. The present invention relates to a coating composition to provide a paint composition.

[Prior Art] A coating composition containing a solvent-soluble hydroxyl group-containing fluorine-containing copolymer as an essential component is known as a coating composition that provides a coating film with excellent weather resistance. For example, JP-A-57-3
4107, JP-A-58-136662, etc.

A coating composition containing a solvent-soluble fluorine-containing copolymer and a fluorine-containing copolymer which are essential components of the coating composition is described.

In addition, since such copolymers are expensive, in order to reduce costs and improve the gloss and sharpness of the paint film, a coating composition containing an acrylic resin has been published in Japanese Patent Publication No. No. 59-197471, JP-A-61-12
760, etc.

However, when an acrylic resin is mixed, there is a problem in that the properties of the fluororesin paint, such as the slipperiness of the coating surface and the water and oil repellency, are impaired.

[Problems to be Solved by the Invention] The present invention aims to solve the above-mentioned problems that the prior art had. That is, the object of the present invention is to provide a paint composition in which an acrylic resin is mixed with a fluororesin paint, and which does not impair the excellent properties of the fluororesin paint.

[Means for solving the problems] The present invention has been made to solve the above-mentioned problems, and includes (A) a fluorine-containing polymer having a crosslinking site (B) (A)
an acrylic copolymer compatible with (A) and (B)
The present invention provides a coating composition characterized in that (C) a polyfluorinated carbon chain-containing compound is blended in an amount of 0.05 to 30% by weight based on the total amount of.

Examples of the crosslinking site of the fluoropolymer having a crosslinking site (A) in the present invention include hydroxyl group, epoxy group, carboxyl group, and amine group. Fluorine-containing polymers having hydroxyl groups as crosslinking sites are preferred because they have excellent reactivity with system curing agents and melamine-based curing agents. However, it is important to use solvent-soluble fluorine-containing polymers for ease of painting, compatibility with acrylic copolymers, and dispersibility of polyfluorinated carbon chain-containing compounds and curing agents. This is preferable in this respect.

As such a solvent-soluble fluoropolymer, a fluoropolymer containing a fluoroolefin and a vinyl ether as essential components is preferably employed. As the fluoroolefin, perhaloolefins, particularly chlorotrifluoroethylene or tetrafluoroethylene, are preferably employed. In addition, as vinyl ether, carbon number 2
Examples include alkyl vinyl ethers containing about 8 to 8 linear, branched, or alicyclic alkyl groups, and those in which the alkyl group has 2 to 4 carbon atoms are particularly preferably employed. Note that the fluoroolefins and vinyl ethers are not limited to being used alone, but may also be used in the form of a mixture of two or more types.

As a method for introducing the crosslinking site into such a fluoropolymer, a method is usually adopted in which a functional group-containing monomer that provides the crosslinking site is copolymerized with the fluoroolefin or vinyl ether. Examples of the functional group-containing monomer that provides a crosslinking site include functional group-containing vinyl ethers such as hydroxyalkyl vinyl ether and glycidyl vinyl ether.

In the present invention, an alkyl vinyl ether having a linear, branched or alicyclic hydroxyl group-containing alkyl group having about 2 to 8 carbon atoms is particularly preferably employed. As such hydroxyl group-containing alkyl vinyl ethers, those in which the hydroxyl group is present at the terminal of the alkyl group, ie, ω-hydroxyalkyl vinyl ethers are preferable. Moreover, the carbon number of the alkyl group containing this hydroxyl group is preferably 2 to 6, particularly 2 to 4. Specific examples of ω-hydroxyalkyl vinyl ether include 2-hydroxyethyl vinyl ether and 4-hydroxybutyl vinyl ether. Alternatively, a crosslinking site may be introduced by modifying the fluoropolymer. For example, a carboxylic acid group can be introduced by reacting a hydroxyl group-containing fluoropolymer with a dibasic acid anhydride.

Such a specific fluoropolymer is a fluoroolefin 4
It is preferable to select from the range of 0 to 80 mol%, alkyl vinyl ether 10 to 80 mol%, and functional It becomes difficult to satisfy the conditions for soluble type, and if the amount is too small, the fluorine content becomes small and the resin becomes insufficient as a weather-resistant paint resin. The content percentage of vinyl ether is
It is selected depending on the fluoroolefin, and if it is too large or too small, it will be disadvantageous in terms of weather resistance and solvent soluble type. Note that if the content of the functional group-containing monomer is too large, the reaction with the curing agent will be too rapid.

Problems such as thickening of the paint during storage and short pot life are likely to occur, and if the amount is too small, sufficient crosslinking density may not be obtained, resulting in poor solvent resistance, surface hardness, etc. It becomes a coating of performance. A suitable content ratio is:
45-55 mol% of fluoroolefins, 20-55 mol% of vinyl ethers, 1-25 mol% of functional group-containing uppers.
Selected from a range of degrees.

In the present invention, it goes without saying that the specific fluoropolymer may be copolymerized with other comonomers in addition to the above-mentioned components. For example, ethylene,
Olefins such as propylene and imbutylene, chlorinated olefins such as vinyl chloride and vinylidene chloride, unsaturated carboxylic acids (esters) such as methacrylic acid and methyl methacrylate, and carboxylic acid vinyl esters such as vinyl acetate and n-vinyl acetate. Examples include the following.

Acrylic copolymer compatible with (A) in the present invention (
B) may be a copolymer containing ticrylate or methacrylate as a main component and compatible with (A), as disclosed in JP-A-59-197471.

Acrylic copolymers described in JP-A-61-12760 and the like are used. In particular, acrylic copolymers containing η-butyl methacrylate, inbutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, etc. as main components are particularly preferred because of their excellent weather resistance.

In addition to the above components, the acrylic copolymer contains acrylate or methacrylate having a hydroxyl group as a copolymerization component, which provides excellent co-crosslinking properties with the fluorine-containing polymer and provides a tough coating film. Therefore, preferable acrylates or methacrylates having such a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxybrobyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
Examples include 4-hydroxybutyl methacrylate, polyethylene glycol monomethacrylate, and polypropylene glycol monomethacrylate. In addition to the above components, the acrylic copolymer also contains methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, benzyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, benzyl methacrylate, methyl acrylate, acrylic acid, methacrylate. Copolymerized with one or more copolymerizable components such as acid, itaconic acid, fumaric acid, maleic anhydride, styrene, acrylonitrile, methoxypolyethylene glycol monomethacrylate, and methoxypolypropylene glycol monomethacrylate. There may be.

Such an acrylic copolymer can be produced by causing a copolymerization reaction to occur in the presence of a polymerization medium such as xylene or toluene with a polymerization initiation source on a bullet polymer composition in a predetermined proportion. can.

In the present invention, in addition to the above-mentioned (A) fluorine-containing polymer having a crosslinking site and (B) an acrylic copolymer compatible with (A), (C) a polyfluorinated carbon chain-containing compound is blended. is important. Examples of polyfluorinated carbons include perfluoroalkyl groups and perfluoroalkylene groups, but usually they can more advantageously improve the water and oil repellency, stain resistance, non-adhesiveness, etc. of the cured coating film. In the present invention, a perfluoroalkyl group is preferable.
A compound having a perfluoroalkyl group having about 1 to 20 carbon atoms is suitably employed, and a compound having a perfluoroalkyl group having about 3 to 15 carbon atoms is particularly desirable. Of course, a perfluoroalkyl group having about 1 to 20 carbon atoms Compounds having alkylene groups may also be employed.

In addition, (C) the polyfluorinated carbon chain-containing compound has a crosslinking site that can be co-crosslinked with the polymer (A) or (B), which provides effects such as slipperiness, water repellency, and oil repellency. Examples of such co-crosslinking sites, which are preferable since they are maintained over a long period of time, include those similar to those exemplified as crosslinking sites for the above-mentioned (A) fluoropolymer having crosslinking sites.

(C) The polyfluorinated carbon chain-containing compound may be a polymer or a non-polymer. Specific examples include the following. That is, as a non-polymer, CF
3 (CF2) n Perfluoroalkyl group-containing alcohol represented by CH2CH20H (n is 0 or an integer from 1 to 19), HOCHz CH20H-(CFz
)*GHzCH20H (m is an integer from 1 to 20), CF
Glycols such as 3-(CF2)nCON(CH2C)I20H)2, CF3-(CF2)□CI2 CH20
S i (OCH3) y or R3-.

R3-x R3-y and y is a silicone compound such as O-3).

Other examples include polyfluorinated carbon chain-containing carboxylic acids and carboxylic acid anhydrides, epoxy compounds, incyanate compounds, amino compounds, melamine compounds, and phenol compounds.

As the polymer, a copolymer of a polyfluorinated carbon chain-containing monomer and a functional group-containing monomer providing a co-crosslinking site is exemplified as a suitable polymer. Naturally, as a polyfluorinated carbon chain-containing monomer, CF3 CCF2 ) 7 CH2CDCl20COC
CH-CH2H CF3 (CF2) s CH2CDCl20COC
It is also possible to employ a monomer that also has a functional group that provides a co-crosslinking site, such as (CH3) =CH2H, and in this case, it is not necessary to copolymerize another functional group-containing monomer.

As the polyfluorinated carbon chain-containing monomer, a monomer having a perfluoroalkyl group having 2 to 18 carbon atoms, preferably 2 to 8 carbon atoms is usually employed, and for example, unsaturated esters such as the following acrylates or methacrylates are used. can be illustrated.

CF3CCF2 )s CH2000G (CH3) Torture C
H20h (CFz )6CCH2)20COC((H
s) MaroCH2CF3 CCF2)6cOO1ll:
H-GHzCF3CCF2)pcH2cIhOcOcH
-CH2CF3 (CF2)7 S02 N (03
R7) CCH2)20GOCI-1GHzCF3 (
CF2)7(CH2)40COCH-CT.

CF3 CCFz)rs02NccH3)CCH2)2
0COCCCH3)-CH2CF3 CCF2)?
S02 N (C2R5) CCH2)20COCH寥CH2CF3(CF2hCONH(CH2)20cOc
H word CH2CF3 CCF2)8 CCH2)200
0G)1-CH2CF3 (CF2)[1(CH2)
20C(Ic(CH3)-CH20h (C:F2)
8 C0NHCCH2)20COC(CH3)-GHz
H(CF2)to(H20COCH=CHzCF2C]
(C:F2)+oC)! 20COC(CHx)-CH2
CF3CCF2)7CH2CHCH20COCH
2H CF3 (CF2 )5 CH2CDCl20COC(
CH3) -CHH In the present invention, a vinyl ether having a perfluoroalkyl group having 2 to 16 carbon atoms, preferably 2 to 8 carbon atoms, can also be employed as the polyfluorinated carbon chain-containing monomer. For example, the following perfluoroalkyl group-containing alkyl vinyl ethers may be exemplified.

CF3(CF2)s CH2CH20CH2CH2
0CH=CH2CF3 (CF2)70H2CH20
GH-CT.

υH CF3 (CF2) s CH20H200H-CH
z As a functional group-containing monomer that can provide a co-crosslinking site to a polyfluorinated carbon chain-containing polymer.

(A) Regarding the fluorine-containing copolymer having a crosslinking site, vinyl ethers having a crosslinking site similar to those described above can be used, and furthermore, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxybutyl methacrylate, Hydroxybutyl acrylate, 2-droxypropyl acrylate, 4-
Hydroxyl group-containing acrylates or methacrylates such as hydroxybutyl acrylate may also be employed.

Of course, this polymer may be copolymerized with other comonomers in addition to the functional group-containing monomer capable of providing the co-crosslinking site with the polyfluorinated carbon chain-containing monomer. 0 For example, benzyl methacrylate, methyl methacrylate, styrene, methyl acrylate, chloroethyl to improve compatibility with (A) fluoropolymer and (B) acrylic copolymer and solubility in paint solvents It is also possible to copolymerize methacrylate, chloroethyl acrylate, etc., or to copolymerize olefins such as fluoroolefins, alkyl vinyl ethers, ethylene and propylene, and chlorinated olefins such as vinyl chloride.

In this polymer, the content ratio of each component is not particularly limited and can be changed in various ways, but usually 1 to 88 mol% of polyfluorinated carbon chain-containing monomer and 0.5 mol% of functional group-containing monomer. ~30 mol%, 0 other comonomers
It can be selected from a range of about 95 mol%. If the amount of the perfluoroalkyl group-containing monomer is too small, not only will the properties such as water and oil repellency, stain resistance, and slip properties of the surface not be improved, but it will also be dispersed uniformly in the coating film.
The effect of surface modification disappears.

In addition, if the amount of functional group-containing additive is too small, reaction with the curing agent will be difficult to occur, increasing the possibility that the polyfluorinated carbon chain-containing compound will exist in a non-co-crosslinked form in the coating film. , it becomes difficult to maintain the effect of modifying the coating film over a long period of time. Furthermore, if the amount is too large, the reaction with the curing agent will occur quickly, and it will be fixed deep in the coating film, reducing the effect of modifying the coating film surface.

In addition, when the polyfluorinated carbon chain-containing compound (C) is a polymer, it is preferable that the molecular weight is smaller than to or ooo.If the molecular weight is too large, the fluidity in the composition will deteriorate and the coating The rate at which it concentrates on the film surface becomes slower, and the effect of modifying the coating film surface becomes smaller.

The blending amounts of each component (A), (El), and (C) are not particularly limited and can be selected as appropriate, but usually, the amount of (A), (El), and (C) is A) is 20 to 80% by weight, (B) is 80 to 10% by weight, and (C) is (A
) and (B) is preferably 0.05 to 30% by weight, if the amount of component (A) is too small,
As a weather-resistant paint composition, sufficient weather resistance cannot be obtained,
This is undesirable, and if the amount of component (B) is too low, sufficient cost reduction cannot be expected, and the flexibility of the coating film is also reduced, which is undesirable, and when the amount of (C) is too small. If the coating film is not sufficiently modified, such as water repellency, oil repellency, or slipperiness, or if it is used in an excessive amount,
Foaming tends to occur, making it difficult to form a coating film with a smooth surface.

The composition of the present invention preferably contains a curing agent or is mixed with a curing agent to be cured. Such curing agents include:
Using a polyfunctional compound that is reactive with the crosslinking site in the (A) fluoropolymer, (B) the hydroxyl group in the acrylic copolymer, and (C) the cocrosslinking site in the polyfluorinated carbon chain-containing compound. It is important to. Examples of such curing agents include heat-curable ones such as melamine curing agents, urea resin curing agents, polybasic acid curing agents, and block polyvalent isocyanates, which are used in ordinary thermosetting acrylic paints. can. Examples of the melamine curing agent include butylated melamine, methylated melamine, epoxy-modified melamine, etc., and various degrees of modification from 0 to B can be used depending on the purpose, and the degree of self-condensation can also be selected as appropriate. .

Examples of the urea resin include methylated urea, butylated urea, and the like. Further, as the polybasic acid curing agent, long-chain aliphatic dicarboxylic acids, aromatic polycarboxylic acids, or their anhydrides are useful. As the block polyvalent isocyanates, block compounds of the polyvalent incyanates described below are suitable. When using melamine or urea hardeners, curing can be accelerated by adding an acidic catalyst.

As the curing agent in the present invention, a room temperature curing type such as polyvalent incyanates can also be used. As polyvalent incyanates, non-yellowing diisocyanates such as hexamethylene diisocyanate and inphorone diisocyanate, and adducts thereof are particularly useful. When curing at room temperature using incyanates,
It is also possible to accelerate curing by adding a curing catalyst such as dibutyltin dilaurate.

The composition of the present invention preferably contains a solvent for reasons such as ease of coating work. Various solvents can be used as such solvents, including aromatic hydrocarbons such as xylene and toluene, alcohols such as n-butanol, esters such as butyl acetate, ketones such as methyl isobutyl ketone, ethyl In addition to glycol ethers such as cellosolve, various thinners for reprinting can also be used, and these can also be used by mixing them in various proportions. It is desirable to select such an organic solvent as appropriate, taking into account the condition of the object to be coated, the evaporation rate, the working environment, etc.

When preparing the coating composition of the present invention, a ball mill,
Various equipment commonly used for making paints can be used, such as a paint shaker, sand mill, jet mill, Miki roll, and kneader. At this time, pigments, dispersion stabilizers, viscosity modifiers, leveling agents, gelling inhibitors, ultraviolet absorbers, etc. can also be added.

When the coating composition of the present invention is used as a heat-curable so-called baking coating, curing agents such as melamine, urea resin, polybasic acids or their anhydrides, and block polyvalent isocyanates are also used in the above formulation. mixed at the same time, −
Used as a liquid paint.

[Examples] The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples in any way.

Examples 1-6. Comparative Examples 1 to 3 Compositions having the composition ratios (parts by weight) shown in Table 1 below were prepared.

In Table 1, the fluorine-containing polymers are as follows.

A-1: Chlorotrifluoroethylene/ethyl vinyl ether/hydroxybutyl vinyl ether/cyclohexyl vinyl ether copolymer, hydroxyl value 58.5 mgK
O) 1/g, A-2: chlorotrifluoroethylene/ethyl vinyl ether/hydro-dipyl vinyl ether copolymer, hydroxyl value 28.5 mgKOH/g acrylic copolymer B-1 and B-2 are as follows, respectively. It's as expected.

B-1: n-butyl methacrylate/2-hydroxyethyl methacrylate/methacrylic acid 85/12/3 (weight ratio) Number average molecular weight approximately 5,000 B-2: n-butyl methacrylate/styrene/2-hydroxyethyl methacrylate/ Methacrylic acid 65/20/12/3 (weight ratio) Number average molecular weight approximately 5,000 Also, polyfluorinated carbon chain-containing compound C-! .

C-2 is as follows.

C-1:CHz-GCIh (n34-10(
7) Mixture) Layer C-02In(CFz)nF n-butyl methacrylate/2-hydroxyethyl methacrylate/methacrylic acid, 10/60/24/3 (
Weight ratio) Number average molecular weight approximately s, oo.

C-2: CH2=CH (mixture of n1m4-10)/
Benzimesho 02 Ha 4CF2)n F Tafrylate/2-hydroxypropyl methacrylate/methacrylic acid, 10/75/1015 (weight ratio) Number average molecular weight approximately 5,000 Furthermore, in Table 1 below, the curing agent is UVAN20SE
80 (product name: Mitsui Toatsu Co., Ltd., methylated melamine curing agent), the solvent is a mixed solvent of xylene and methyl isobutyl ketone (volume ratio 1/1), and the ultraviolet absorber is Piosolve 130 (product name: Kyodo Yakuhin type). be.

Table 1 Each of the compositions shown in Table 1 above was applied to a 0.8 m thick aluminum plate (Mitsubishi Aluminum Co., Ltd. "5052-
On the chromate-treated surface of Ha4''), a dry film thickness of 20 to 30 IL was coated using a film applicator, and 14G'' was cured by heating for 30 minutes. Here are the results of testing the obtained coating film! It is shown in the s2 table.

Table 2: Weather resistance: Sunshine Weather Ohmeter 3000
Examples 7 to 1'3 in which gloss retention after time was measured Compositions having the composition ratios (weight ratios) shown in Table 3 above were prepared. In Table 3, polyfluorinated carbon chain-containing compound C
-3, C-4, and C-5 are as follows, respectively.

C-3: CF3(CF2)ncH2cHzOH(n-
(Mixture of n-7 to 11) Satoshi (Mixture of n-7 to 11) (Mixture of n-7 to 11) Table 3 Each of the compositions shown in Table 3 above was prepared on a 0.8 mm thick aluminum plate ( Manufactured by Mitsubishi Aluminum “5052-”
It was applied to the chromate-treated surface of H34'') using a film applicator to a dry film thickness of 20 to 30 l, and was heated and cured in 30 volumes at 140°C.The results of testing the resulting coating film. are shown in Table 4.

Table 4 [Effects of the Invention] The present invention has the effect of providing a coating composition that is excellent in weather resistance and is inexpensive, and furthermore, a coating film using the coating composition of the present invention has water repellency. It has the effect of having excellent surface properties such as oil repellency and slipperiness.

It also has the effect of producing a coating film with a high gloss close to that of acrylic resin while retaining the surface characteristics typical of fluororesin. Furthermore, by using a polyfluorinated carbon chain-containing compound capable of co-crosslinking, the above-mentioned excellent surface properties can be maintained for a long period of time. Furthermore, by controlling the amount of the polyfluorinated carbon chain-containing compound added, a coating film with superior surface smoothness can be obtained than when no compound is added.

Claims (1)

[Claims] 1. (A) a fluorine-containing polymer having a crosslinking site (B) (A
) and an acrylic copolymer compatible with (A) and (B
1. A coating composition characterized in that (C) a polyfluorinated carbon chain-containing compound is blended in an amount of 0.05 to 30% by weight based on the total amount of (C). 2. The composition according to claim 1, wherein (C) the polyfluorinated carbon chain-containing compound is a compound capable of co-crosslinking with (A) and/or (B).