JPH0517535A - Fluorine-containing copolymer having silyl group and coating composition - Google Patents

Abstract

(57) [Abstract] [Purpose] Fluorine-containing copolymer and coating composition which have excellent weather resistance, high water repellency for a long period of time, and provide a coating film having excellent anti-icing property and anti-paper-sticking property. I will provide a. [Structure] A polymerization unit based on a fluoroolefin-based monomer such as tetrafluoroethylene and a silane-based monomer such as vinyloxysilane, allyloxysilane or isopropenoxysilane is an essential unit, and if necessary, a hydrocarbon-based monomer Polymers having units based on the body and monomers having cure reactive sites.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fluorinated copolymer having a silyl group and a coating composition.

[0002]

2. Description of the Related Art The applicant of the present invention has filed Japanese Patent Application Laid-Open Nos.
As shown in JP-A-58-136662, fluoroolefin, cyclohexyl vinyl ether, alkyl vinyl ether, and hydroxyalkyl vinyl ether copolymers can be cured at room temperature and by baking with a curing agent such as melamine and isocyanate, and have high gloss resistance. It has already been found to provide a weather resistant coating film having excellent solvent resistance, chemical resistance and water repellency. However, as a result of promoting the application of the above-mentioned copolymer as a solvent-based coating, for example, in applications such as automobile top-coating, when a higher level of aesthetics is pursued, the above-mentioned fluorine-containing resin copolymer is not necessarily repelled Not enough water.

In order to make up for this point, 0.1 to 30 parts by weight of a perfluoroalkyl group-containing polymer capable of co-crosslinking with the fluorine-containing copolymer is added to 100 parts by weight of the fluorine-containing copolymer. A resin composition for paints has been proposed (see JP-A-61-152771). However, although the coating film obtained from the coating composition exhibits relatively good initial water repellency, it is still inferior in comparison with the waxed state and its durability is not sufficient. Further, since it contains a perfluoroalkyl group, it has a high oil repellency and has a drawback that defects such as cissing of the coating film are likely to occur.

Further, a polymer obtained by homopolymerizing a vinyl monomer having a silyl group represented by the formula b ') described below and a vinyl monomer other than fluoroolefin are copolymerized. The copolymer obtained as described above is easily hydrolyzed and thus has high water repellency, but it is difficult to use it as a resin for paints.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and improves the appearance and performance of the coating film (for example, weather resistance, water repellency, anti-icing property, sticking paper). It is intended to provide a fluorine-containing copolymer having a silyl group and a coating composition which are used in a coating composition which gives a coating film excellent in prevention property).

[0006]

The present invention has been made to solve the above-mentioned problems, and a coating obtained from a coating composition containing the fluorinated copolymer having a silyl group of the present invention. The film exhibits excellent water repellency, particularly a high receding contact angle, and its sustainability for a long period of time, so that it is suitable as a top coat paint for automobiles, a paint for preventing icing, and a paint for preventing sticking. In particular, when it is used as a topcoat paint for automobiles, it has an advantage over other water-repellent paints containing a perfluoroalkyl group that defects such as cissing are less likely to occur during film formation.

In the present invention, a key technique for achieving high water repellency is that a polymerized unit containing a silyl group represented by the following formula b) and a fluoroolefin system represented by the following formula a) are used. And a polymerized unit.

The vinyl monomer containing a silyl group of the formula b ') described below is a polymer obtained by polymerization alone, and a copolymer obtained by copolymerizing with a vinyl monomer other than fluoroolefin. It is known that polymers are easily hydrolyzed (S. Murahashi, S. Nozakura et al., J. Polyme
r Sci. (B), 3,245 (1965)), which could not be used as a resin for paints, but a copolymer of this monomer and fluoroolefin was surprisingly very difficult to hydrolyze, Acid resistance equivalent to fluorine-containing copolymers represented by fluoroolefins, cyclohexyl vinyl ethers, alkyl vinyl ethers and hydroxyalkyl vinyl ether copolymers as shown in JP-A-57-34107 and JP-A-58-136662. It has been found by the experiments shown in the examples that it has resistance, alkali resistance, and other chemical resistance.

A coating film obtained from a coating composition containing the fluorinated copolymer having a silyl group is
I learned that it has weather resistance, high water repellency, solvent resistance, and chemical resistance.

The fluorine-containing copolymer having a silyl group in the present invention is a polymerization containing 40 to 60 mol% of a fluoroolefin-based polymer unit represented by the formula a) and a silyl group represented by the formula b). Containing 0.5 to 60 mol% of units, 0 to 55 mol% of vinyl-based polymerized units represented by the formula c), and 0 to 55 mol% of polymerized units having a curing reactive site represented by the formula d). Is. In the formulas (a), (b), (c) and (d), X represents fluorine, chlorine, a C1-8 perfluoroalkyl group or a C1-8 perfluoroalkoxy group. R ¹ represents hydrogen or a methyl group. R ² represents a monovalent hydrocarbon group. Y represents an organosiloxy group or a fluoroalkyl group. k represents 0 or 1. m represents an integer of 0 to 3. R ³ represents hydrogen or a methyl group. R ⁴ is an alkyl group having 1 to 12 carbon atoms,
C3-C12 cycloalkyl group or C2-1
Represents a fluoroalkyl group of 0. p represents 0 or 1. q represents 0 or 1. R ⁵ represents hydrogen or a methyl group. R ⁶ represents a divalent organic group. r represents 0 or 1. Z represents a curing reactive site. )

[0011]

[Chemical 5]

[0012]

[Chemical 6]

[0013]

[Chemical 7]

[0014]

[Chemical 8]

The fluorine-containing copolymer having a silyl group of the present invention has the following formula a '), formula b'), formula c ') and formula d.
It can be obtained by copolymerizing the monomer represented by '). If necessary, a part of each monomer may be protected and then polymerized, and the protection may be released after the polymerization.

Formula a ') CF ₂ = CFX (where X
Represents fluorine, chlorine, a perfluoroalkyl group having 1 to 8 carbon atoms or a perfluoroalkoxy group having 1 to 8 carbon atoms. )

Formula b ') CH ₂ = CR ¹ (CH ₂ ) _k O
Si (R ² ) _m Y _(3-m) (wherein R ¹ represents hydrogen or a methyl group. R ² represents a monovalent hydrocarbon group. Y represents an organosiloxy group or a fluoroalkyl group.
k represents 0 or 1. m represents an integer of 0 to 3. )

Formula c ') CH ₂ = CR ³ (CH ₂ ) _p O
(C═O) _q R ⁴ (wherein R ³ represents hydrogen or a methyl group. R ⁴ represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a fluoro group having 2 to 10 carbon atoms). Represents an alkyl group, p represents 0 or 1, q represents 0 or 1.)

Formula d ') CH ₂ = CR ⁵ (CH ₂ ) _r O
R ⁶ Z (provided that R ⁵ represents hydrogen or a methyl group.
R ⁶ represents a divalent organic group. r represents 0 or 1. Z
Represents a curing reactive site. )

When the amount of the fluoroolefin polymer unit represented by the formula a) is less than the above range, sufficient weather resistance cannot be obtained when used as a paint base, which is not preferable. On the other hand, if the amount is too large, the solubility in various solvents decreases, making it difficult to use as a paint base or a paint additive.

Here, examples of the fluoroolefin-based monomer represented by the formula a ') include carbons such as tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, hexafluoropropylene and pentafluoropropylene. A fluoroolefin of about 2 to 4 or perfluoropropyl vinyl ether or perfluoro-2-methyl-3-oxahexyl vinyl ether, where X has about 1 to 8 carbon atoms and is linear, branched or cyclic Fluoro vinyl ether is mentioned.

When the number of polymerized units containing a silyl group represented by the formula b) is less than the above range, the coating film does not have sufficient water repellency, and when it is too much, sufficient weather resistance is obtained. Is not obtained, which is not preferable. A particularly preferred range of polymerized units containing a silyl group represented by formula b) is from 5 to 40.
Mol%.

Here, the silyl group-containing vinyl monomer represented by the formula b ') is one in which R ² is one or more kinds of alkyl group, cycloalkyl group, aryl group or aralkyl group. Those are preferable. Particularly, R ² is preferably an alkyl group, a cycloalkyl group or an aryl group having about 1 to 6 carbon atoms.

Suitable compounds as the vinyl monomer containing a silyl group represented by the formula b ') include vinyloxytrimethylsilane, vinyloxyethyldimethylsilane, vinyloxyhexyldimethylsilane, vinyloxycyclohexyldimethylsilane, Vinyloxy group or isopropenoxy group on the silicon atom, such as vinyloxyphenyldimethylsilane, isopropenoxytrimethylsilane, isopropenoxyethyldimethylsilane, isopropenoxyhexyldimethylsilane, isopropenoxycyclohexyldimethylsilane, and isopropenoxyphenyldimethylsilane. Group having a group and an alkyl group or a phenyl group, vinyloxypentamethyldisiloxane, vinyloxyheptamethyltrisiloxane, isopropenoxypentamethyldisiloxy Having a vinyloxy group or an isopropenoxy group and a (poly) organosiloxy group on the silicon atom, such as benzene and isopropenoxyheptamethyltrisiloxane, 1H, 1H, 2H, 2H-perfluorodecyldimethylsilyl vinyl ether, 1H, 1H Examples thereof include silane compounds containing a vinyloxy group or an isopropenoxy group and a polyfluoroalkyl group such as 2,2H, 2H-perfluorodecyldimethylsilylisopropenyl ether, and allylsilyl ethers such as trimethylsilylallyl ether.

In particular, vinyloxytrimethylsilane and isopropenoxytrimethylsilane are inexpensive raw materials and are easy to synthesize (for example, P. Cazeau et al, Tetrahed).
oron Vol.43, No.9, pp.2075 (1987)) and high water repellency.

If the amount of vinyl-based polymer units represented by the formula c) is less than the above range, the properties of the coating film will not be sufficient, and if it is too large, the weather resistance of the coating film will deteriorate. Yes, it is not preferable. A particularly suitable range of the vinyl polymer unit represented by the formula c) is 5 to 35 mol%.

Examples of vinyl monomers represented by the formula c ') include vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether; methyl isopropenyl ether, ethyl isopropenyl ether, propyl. Isopropenyl ethers such as isopropenyl ether, butyl isopropenyl ether, cyclohexyl isopropenyl ether, etc .; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl stearate, isopropenyl acetate, isopropionate Linear vinyl carboxylates or isopenyl carboxylates such as propenyl and isopropenyl butyrate; ethyl allyl ether, propyl allyl ether, butyrate Allyl ethers, allyl ethers, such as isobutyl allyl ether, ethyl allyl ester, propyl allyl ester, butyl allyl ester, isobutyl allyl ester, and the like alkyl allyl esters such as cyclohexyl allyl ester.

Of these, vinyl ethers and isopropenyl ethers are particularly preferable because they have good alternating copolymerizability with fluoroolefins.

When the number of polymerized units having a curing reactive site represented by the formula d) is less than the above range, the solvent resistance of the cured coating film may be deteriorated when used as a paint base. , Not preferable. On the other hand, if the amount is too large, the cured coating film becomes hard and brittle, and the hydroxyl groups remaining in the cured coating film may cause a decrease in water repellency, which is not preferable. A particularly preferable range of the polymerized unit having a curing reactive site represented by the formula d) is 5 to 20 mol%.

The curing reactive site of the vinyl monomer having the curing reactive site represented by the formula d ') includes a hydroxyl group, a carboxyl group, an acid amide group, an amino group, a mercapto group and a β-ketoester group. , Active hydrogen groups such as silanol groups, epoxy groups, carbon-carbon unsaturated groups, bromine,
Examples thereof include active halogen groups such as iodine and hydrolyzable silyl groups such as alkoxysilyl groups.

Of these, the active hydrogen-containing group is preferable in that it is excellent in reactivity with an isocyanate type curing agent, an aminoplast type curing agent and the like which are usually used as a curing agent, and a hydroxyl group is particularly preferable. However, since the active hydrogen group reacts with the vinyl-based monomer containing the silyl group represented by the formula b ′), the monomer represented by the formula d ′) should be protected with a silyl group or the like. It is necessary to copolymerize after that, and deprotect after polymerization.

Further, R ⁶ of the vinyl monomer having a curing reactive site represented by the formula d ') is an alkylene group, a cycloalkylene group, an arylene group, a (poly) oxyalkylene group or (poly). ) Ester chains and (poly) siloxy groups are preferred. Further, if the chain length of R ⁶ is made long, a flexible coating film can be obtained, but if it is too long, weather resistance and coating film hardness may decrease, which is not preferable. Further, if it is too short, the reactivity of the curing-reactive site becomes low, and it may be difficult to obtain a cured coating film, so caution is required. Preferably, a chain of R ⁶ 1 to 20, in particular, it is preferable that the binding of 2 to 12 atoms.

As the vinyl-based monomer having such a curing reactive site, 2-hydroxyethyl vinyl ether,
Hydroxyalkyl vinyl ethers such as 3-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 9-hydroxynonyl vinyl ether, 1-hydroxymethyl-4-vinyloxymethyl cyclohexane and 3-chloro-2-hydroxypropyl vinyl ether; 2-hydroxyethyl Isopropenyl ether, 3-hydroxypropyl isopropenyl ether,
Hydroxyalkyl isopropenyl ethers such as 4-hydroxybutyl isopropenyl ether, 9-hydroxynonyl isopropenyl ether, 1-hydroxymethyl-4-isopropenoxymethylcyclohexane, 3-hydroxy-2-chloropropyl isopropenyl ether; 2 -Hydroxyalkyl allyl ethers such as hydroxyethyl allyl ether;
Polyether macromonomers having a vinyloxy group, an isopropenoxy group, or an allyloxy group at one end and a hydroxyl group at the other end, such as Chemical formula 11 and Chemical formula 12;

[0034]

[Chemical 9]

(R ¹ in the chemical formula 9 is hydrogen or a methyl group, k is 1 to 10, m is 1 to 4, and n is an integer of 2 to 20)

[0036]

[Chemical 10]

(In the chemical formula 10, k is 1 to 10 and m is 1 to 4
, N is an integer from 2 to 20)

[0038]

[Chemical 11]

(R ¹ in the chemical formula 11 is hydrogen or a methyl group, k is 1 to 10, m is 1 to 4, and n is an integer of 0 to 20,
The oxyethylene unit and the oxypropylene unit may be arranged in any type of block and random)

[0040]

[Chemical 12]

(In the formula 12, k is 1 to 10 and m is 1 to 4
, N is an integer of 0 to 20, and the oxyethylene unit and the oxypropylene unit may be arranged in any type of block and random).

Polyester macromonomers having a vinyloxy group or an isopropenoxy group at one end and a hydroxyl group at the other end, such as Chemical formula 13;

[0043]

[Chemical 13]

(R ¹ in Chemical formula 13 is hydrogen or a methyl group, k is 1 to 10, m is 3 to 5, and n is an integer of 1 to 5)

Polysiloxane macromonomers having a vinyloxy group or an isopropenoxy group at one end and a hydroxyl group at the other end, such as Chemical formula 14;

[0046]

[Chemical 14]

(R ¹ in the chemical formula 14 is hydrogen or a methyl group, k is 1 to 10, and m is 1 to 20)

A monomer having a vinyloxy group or an isopropenoxy group at one end and a carboxyl group at the other end, such as Chemical formula 15;

[0049]

[Chemical 15]

(In the formula 15, R ¹ is hydrogen or a methyl group, R ² is an alkyl group having 1 to 10 carbon atoms or 3 to
(10 cycloalkyl groups, k is an integer from 1 to 10)

Monomers having a vinyloxy group or an isopropenoxy group at one end and a .beta.-ketoester group at the other end, such as Chemical formula 16; and the like, include vinyl monomers having active hydrogen.

[0052]

[Chemical 16]

(Wherein R ¹ is hydrogen or a methyl group, R ² is an alkyl group having 1 to 10 carbon atoms or 3 to
(10 cycloalkyl groups, k is an integer from 1 to 10)

It is necessary that these active hydrogens be substituted with a protecting group such as a trialkylsilyl group and protected during the polymerization from reaction with a vinyl monomer having a silyl group represented by the above formula b). After polymerization, it can be deprotected by addition of a primary alcohol or the like to be made active hydrogen again.

Further, as the vinyl-based monomer having a curing reactive site other than active hydrogen,
A monomer having a chain or alicyclic epoxy or glycidyl group and a vinyloxy group or an isopropenoxy group, such as;

[0056]

[Chemical 17]

(R ¹ in Chemical Formula 17 is hydrogen or a methyl group, R ² is an alkyl group having 1 to 10 carbon atoms, and k is an integer of 1 to 10)

[0058]

[Chemical 18]

(R ¹ in Chemical formula 18 is hydrogen or a methyl group, and k is an integer of 1 to 10)

[0060]

[Chemical 19]

(R ¹ in Chemical formula 19 is hydrogen or a methyl group, and k is an integer of 1 to 10)

Alternatively, vinyl monomers having a hydrolyzable silyl group such as 2-vinyloxyethyltrimethoxysilane may be used.

These monomers represented by the formulas a ') to d') may be used alone or in combination of plural kinds.

When the fluorine-containing copolymer of the present invention is used as a paint base, the intrinsic viscosity at 30 ° C. in tetrahydrofuran in the uncrosslinked state (hereinafter referred to as [η]) is 0.05 to 2.0 dl / g. Are preferred. When [η] is smaller than the above range, it is difficult to obtain strength of the coating film,
Also, the larger one is not preferable because it is poor in paintability and painting workability. Particularly, those having [η] of 0.1 to 1.5 dl / g are preferable.

The above-mentioned copolymer is a copolymerization reaction in which a polymerization initiator such as a polymerization initiator or ionizing radiation is allowed to act on a monomer mixture in a predetermined ratio in the presence or absence of a polymerization catalyst. It can be manufactured by carrying out.

As the polymerization initiator, a water-soluble one or an oil-soluble one can be appropriately used depending on the type of polymerization or the polymerization medium.

Specifically, as the water-soluble initiator, a persulfate such as potassium persulfate, hydrogen peroxide or a redox initiator composed of these and a reducing agent such as sodium bisulfite and sodium thiosulfate, and further these Inorganic initiators such as those in which a small amount of iron, ferrous salt, silver nitrate, etc. coexist, or dibasic acid oxides such as disuccinic acid peroxide, diglutaric acid peroxide, and monosuccinic acid peroxide, azobisisobutylamidine dibasic An organic initiator such as an acid salt, or an oil-soluble initiator is t
Examples include peroxyester type peroxides such as butyl peroxyacetate, dialkyl peroxydicarbonates such as diisopropyl peroxydicarbonate, benzoyl peroxide, and azobisisobutyronitrile.

The amount of the polymerization initiator used can be appropriately changed depending on the type and the conditions of the copolymerization reaction, but usually about 0.05 to 0.5% by weight is adopted with respect to the total amount of the monomers to be copolymerized. To be done.

In the above copolymerization reaction, the reaction mode is not particularly limited, and bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization and the like can be adopted, but the stability of the polymerization operation, the produced copolymer From the standpoint of ease of separation, etc., emulsion polymerization in an aqueous medium or alcohols such as t-butanol,
Solution polymerization using an ester, a saturated halogenated hydrocarbon containing one or more fluorine atoms, an aromatic hydrocarbon such as xylene, etc. as a solvent is preferably adopted. When the copolymerization reaction is carried out in an aqueous medium, it is preferable to add a basic buffering agent so that the pH value of the liquid during polymerization does not fall below 4, preferably 6. The addition of the basic substance is also effective in the case of solution polymerization.

These methods are batch type, semi-continuous type,
Of course, it can be performed by a continuous operation. In the copolymerization reaction, the copolymerization reaction temperature is -30.
The optimum value is appropriately selected within the range of ℃ to +150 ℃ according to the type of polymerization initiator, polymerization medium, etc., but when the copolymerization reaction is performed in an aqueous medium, 0 ℃ to +100 ℃ , Preferably about 10 ° C to 90 ° C. The reaction pressure can be appropriately selected, but is usually 1 to 100 kg / cm.
² , especially 2 to 50 kg / cm ² is preferable.

In order to suppress the [η] of the produced copolymer within the above range, a reaction medium having a relatively large chain transfer constant may be used, or the copolymerization reaction may be appropriately carried out in the presence of a chain transfer agent. Is preferred.

The fluorocopolymer of the present invention is useful as a paint base or a paint additive which gives a coating film having weather resistance, water repellency, antifouling property, chemical resistance and non-adhesiveness.

When the fluorine-containing copolymer of the present invention is used as a coating base, it is preferable to add a curing agent and the like to obtain a coating composition. Here, as the curing agent,
Those having a group capable of reacting with the curing reaction site of the fluorine-containing copolymer of the present invention and giving a good cured product are adopted. Examples of such a curing agent include polyisocyanates, aminoplasts, polybasic acid anhydrides and metal alkoxides.

Examples of the polyisocyanate system include polyisocyanate compounds such as hexamethylene diisocyanate and isophorone diisocyanate, silyl isocyanate compounds such as methylsilyltriisocyanate, partial condensates and multimers thereof, and isocyanate groups blocked with phenol and the like. Examples include blocked polyisocyanate compounds blocked with agents. Particularly, a non-yellowing type is preferably used.

As the aminoplast, melamine resin,
Guanamine resin, urea resin, etc. are adopted. Among them, methylol melamine at least partially etherified with one or more lower alcohols such as methanol, ethanol, propanol and butanol is used.

As the polybasic acid anhydride, phthalic anhydride,
Examples thereof include aromatic polycarboxylic acid anhydrides such as pyromellitic dianhydride, and aliphatic polycarboxylic acid anhydrides such as maleic anhydride and succinic anhydride.

In the present invention, the blending amount of each component can be appropriately selected, but in order not to impair the excellent coating film performance of the fluorocopolymer of the present invention such as weather resistance, the above-mentioned contents are included. The curing agent is 0.5 to 100 parts per 100 parts of the fluorocopolymer.
An amount of about 300 parts by weight is used. In particular, it is preferable that the amount of the curing agent is about 5.0 to 100 parts by weight per 100 parts of the fluorocopolymer.

The coating composition of the present invention may optionally contain various additives in addition to the above two components. Such additives include solvents, synthetic resins, curing catalysts, heat stabilizers, leveling agents, lubricants, pigments, dyes, viscosity modifiers,
Examples include dispersion stabilizers, ultraviolet absorbers, gelation inhibitors, and the like.

Particularly, when an ultraviolet absorber is added,
Even when a transparent coating film is formed, the effect of protecting the substrate is sufficiently exhibited, which is preferable. As such an ultraviolet absorber, it is possible to use all of the ultraviolet absorbers that can usually be blended in the paint,
For example, a phenyl salicylate-based, benzotriazole-based, benzophenone-based ultraviolet absorber or the like can be used. Further, by using a reactive ultraviolet absorber, it is possible to exert its effect for a long period of time. The ultraviolet absorber is preferably used in an amount of about 0.01 to 50 parts by weight, particularly about 0.1 to 30 parts by weight, based on 100 parts of the fluorocopolymer.

When the fluorine-containing copolymer of the present invention is dissolved or dispersed in an organic solvent, such solvents include xylene, aromatic hydrocarbons such as toluene, alcohols such as n-butanol, butyl acetate and the like. In addition to the esters, ketones such as methyl isobutyl ketone, and ethyl cellosolve glycol ethers, various commercially available thinners can be adopted, and these can be mixed and used at various ratios.

When the fluorinated copolymer of the present invention is added to another synthetic resin, the fluorinated copolymer of the present invention tends to be oriented on the surface of the coating film. A coating layer based on the fluorocopolymer will be formed. Therefore, the fluorine-containing copolymer of the present invention has excellent weather resistance, water repellency, antifouling property, chemical resistance, non-adhesiveness and other coating film physical properties even when added in a small amount to a synthetic resin coating. Can be achieved.

When the fluorine-containing copolymer of the present invention is added to a synthetic resin coating and used, 1 to 80 parts by weight of the fluorine-containing copolymer of the present invention is added to 100 parts by weight of the coating film-forming resin component.
In particular, it is preferable to add about 5 to 50 parts by weight to obtain a coating composition. If the blending amount of the fluorinated copolymer of the present invention is too small, various properties cannot be imparted to the coating film, and if it is too large, it may be economically disadvantageous such as cost increase.

Here, as the synthetic resin paint, general synthetic resin paints such as acrylic, urethane, fluorine, phenol, epoxy and silicone are used.

When preparing the coating composition of the present invention,
Various compounding machines such as a ball mill, a sand mill, a jet mill, a kneader, a triple roll, and a paint shaker which are usually used for compounding a resin composition can be used.

Further, the above-mentioned steel sheet coated with the fluorine-containing copolymer of the present invention as a coating base or a top coating with a coating composition in which it is used as a coating additive is very useful as an automobile outer panel.

Usually, such an automobile steel sheet is subjected to intermediate coating with a synthetic resin coating for design and the like. Top coating with the coating composition containing the fluorine-containing copolymer of the present invention may be coating before drying / curing of the intermediate coating, so-called wet-on-wet coating,
The so-called dry-on-wet coating, which is coating after drying and curing the intermediate coating, may be used. Further, a synthetic resin paint may be applied and the used paint may be overcoated.

The outer panel for automobiles, which has been overcoated with the coating composition containing the fluorine-containing copolymer of the present invention, is excellent in weather resistance, water repellency, antifouling property, chemical resistance, non-adhesiveness and the like. Since the coating film performance continues for a long period of time, it is possible to reduce the work such as cleaning and waxing.

Further, the coating composition containing the fluorine-containing copolymer of the present invention is useful as an anti-icing coating composition because the coating film of the composition retains the antifreezing performance for a long period of time. Is. When used for this purpose, a coating composition is used in which 5 to 50 parts by weight of polyisocyanate or blocked polyisocyanate is used with respect to 100 parts by weight of the fluorocopolymer of the present invention. If polyisocyanate is used as the curing agent, it can be used as a two-pack type paint, and if blocked polyisocyanate is used, it can be made into one-pack type.

Further, if necessary, the composition for anti-icing paint of the present invention may contain pigments, dyes, etc., which are usually used in paints, in the range of about 120 parts by weight or less based on 100 parts by weight of the resin solid content. It can be added. In addition, a paraffin substance such as liquid paraffin may be blended in order to improve the sustainability of preventing ice accretion and reduce the shear fracture strength at the ice-coating interface. Other surfactants and additives can also be added as appropriate.

Further, the coating composition containing the fluorine-containing copolymer of the present invention has non-adhesiveness and is therefore useful as a paper-sticking coating. When used for this purpose, a coating composition can be prepared by blending 5 to 60 parts by weight of the fluorocopolymer of the present invention with 100 parts by weight of commercially available acrylic, urethane, epoxy and fluororesin. If necessary, 5 to 30 parts by weight may be added per 100 parts by weight of the resin component for forming a coating film.
The curing agent is used in an amount of about parts by weight, and various additives such as a plasticizer can be appropriately added.

[0091]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

Example 1 (Synthesis of Fluorine-Containing Copolymer Containing Silyl Group (SF-1)) 50.7 g of xylene, 50.7 g of t-butyl alcohol, and Table 1 were placed in an autoclave with a stirrer made of stainless steel and having an internal volume of 200 cc. The ratios of isopropenoxytrimethylsilane (hereinafter referred to as IPSE), cyclohexyl vinyl ether (hereinafter referred to as CHVE), ethyl vinyl ether (hereinafter referred to as EVE), 4-trimethylsiloxybutyl vinyl ether (hereinafter referred to as S-HBVE), and , T-Butylperoxypiperate 0.1 g and potassium carbonate 0.8 g were charged, and dissolved oxygen was removed by solidification and deaeration with liquid nitrogen.

After that, chlorotrifluoroethylene (hereinafter referred to as CTFE) in the ratio shown in Table 1 was introduced into the autoclave, and the temperature was gradually raised. After the temperature in the autoclave reached 65 ° C., the reaction was continued under stirring for 24 hours, 10 g of ethanol was further introduced, the stirring was continued for 2 hours, and then the autoclave was cooled with ice to stop the reaction. After reaching room temperature, unreacted monomers were purged and the autoclave was opened.

The polymer obtained was treated with water / methanol (1:
1), and after removing the supernatant liquid, heat to 60 ° C and dry under a reduced pressure of 1 mmHg for 24 hours.
It was crushed with an impact hammer to obtain a silyl group-containing fluorocopolymer (SF-1). [Η] of the obtained copolymer
The value of was 0.10 dl / g. Further, it was confirmed from the IR spectrum that all the polymerized units based on S-HBVE were converted into polymerized units based on hydroxybutyl vinyl ether (hereinafter referred to as HBVE). The IR spectrum is shown in FIG. 1, and the copolymer composition measurement results by ¹³ C-NMR spectrum are shown in Table 2.

Examples 2 to 4 (Synthesis of Fluorine-Containing Copolymer Having Silyl Group (SF-2 to 4)) The same as Example 1 except that the ratios of the monomers are shown in Table 1. went. Table 2 shows the copolymer composition and [η] measurement results by ¹³ C-NMR spectrum.

Comparative Examples 1 and 2 (Synthesis of Conventional Fluororesin Copolymer (F-1 and F-2)) The same procedure as in Example 1 was carried out except that the ratio of the monomers was as shown in Table 1. . Table 2 shows the copolymer composition and [η] measurement results by ¹³ C-NMR spectrum.

[0097]

[Table 1]

TFE: tetrafluoroethylene PPVE: Perfluoro (propyl vinyl ether) VEOVA: vinyl versatate

[0099]

[Table 2]

Comparative Example 3 0.1 g of azobisisobutyronitrile and 50 g of ethyl acetate were placed in a three-necked flask and heated to 80 ° C. for 1H, 1H, 2H, 2.
H-perfluorooctyl methacrylate 10.3 g, n-butyl methacrylate 12.0 g, 2-hydroxyethyl methacrylate 2.7 g, methacrylic acid 0.6 g, dodecyl mercaptan 0.5 g, azobisisobutyronitrile
A solution consisting of 0.1 g and 20 g of ethyl acetate was added dropwise over 3 hours. After that, the mixture was stirred at the same temperature for 2 hours to obtain a resin solid content of 49%,
A solution of an acrylic resin having a number average molecular weight of 7,000 (hereinafter referred to as PFMA) was prepared. To 100 parts by weight of the copolymer (F-1) obtained in Comparative Example 1, 5 parts by weight of the above PFMA was added to obtain a coating resin (F-3).

Coating Composition Production Example 1 Using the xylene solution (65%) of the silyl group-containing fluorocopolymer (SF-1) obtained in Example 1 above,
A clear coat paint was produced with the composition shown below. The blending amount is shown in parts by weight. In addition, SF-2 to 4, Comparative Example 1
The F-1 to 3 obtained in 3 to 3 were also manufactured by the same method. Then, it was diluted with Solvesso 150 (trade name: manufactured by Exxon) to a viscosity of 25 seconds (Ford cup 4/20 ° C.), and applied with a spray gun.

[0102] SF-1 (65% xylene solution) 154 parts Yuban 20SE Note 1) 50 copies n-Butyl alcohol 10 parts Tinuvin 900 (10% xylene) Note 2) 24 parts Tinuvin 144 (10% xylene) Note 3) 8 parts BYK300 Note 4) 0.5 part

Note 1) Butylated melamine-based curing agent: manufactured by Mitsui Toatsu Co., Ltd. Note 2) UV absorber: manufactured by Ciba Geigy. Note 3) Light stabilizer: manufactured by Ciba Geigy. Note 4) Surface modifier: manufactured by BYK Chemie.

Preparation of test plate and coating film performance test 1 On a dull steel plate having a thickness of 0.8 mm, which was subjected to chemical conversion treatment with zinc phosphate,
A cationic electrodeposition coating for automobiles was applied to a film thickness of 25 μm and heat-cured at 170 ° C. for 30 minutes. Next, an intermediate coating for automobiles was applied, baked at 140 ° C for 30 minutes, sanded with No. 600 sandpaper, dried, and degreased with white gasoline to prepare a test material.

The viscosity of the base coat paint is applied to this material.
After adjusting to 13.5 seconds, it was coated with an air spray gun W-61 (made by Iwata Cup Co., Ltd.) so that the dry film thickness would be 18μ, and allowed to stand at room temperature for 3 minutes, followed by clearing with SF-1. Coat paint, air spray gun W-61
Wet-on-wet coating with a dry film thickness of 30μ using, and leave it at room temperature for 10 minutes and then 140 ° C in a hot air drying oven.
A test plate was prepared by baking for 30 minutes.

Table 3 shows the results of evaluation of various coating film properties of the test plates thus obtained.

[0107]

[Table 3]

1) Measured with Suga Test Instruments Co., Ltd. digital variable angle gloss meter UGV-4D 2) Measured hardness with Mitsubishi Pencil Co., Ltd. Uni 3) 10% sulfuric acid 0.3cc was applied Spot the surface, leave it at 20 ° C for 24 hours, then wash it with water and observe the coated surface 4) Spot 10% NaOH 0.3cc on the coated surface, leave it at 20 ° C for 24 hours, then wash it with water and observe the coated surface 5) Regular After 24 hours of immersion in gasoline (Nippon Oil Co., Ltd.) at room temperature, the appearance is visually evaluated. 6) FACE contact angle meter (CA-D type) manufactured by Kyowa Interface Science Co., Ltd.
The contact angle of water is measured using a 7) Dew panel light control weather meter (manufactured by Suga Test Instruments Co., Ltd.) After 4000 hours of exposure test, 60 ° gloss retention, color difference ΔE and water repellency are measured.

Coating Composition Production Example 2 A xylene solution (65%) of the silyl group-containing fluorocopolymer (SF-1) obtained in Example 1 above and hexamethylene diisocyanate (Coronate 2906: Nippon Polyurethane ( Co., Ltd.), a two-component coating material in solid content ratio
It was mixed in a ratio of 82/18 to produce an anti-icing paint. The blending amount is shown in parts by weight.

Further, SF-2 to 4 and F-1 to 3 obtained in Comparative Examples 1 to 3 were manufactured by the same method.

Preparation of test plate and coating film performance test 2 The above-mentioned anti-icing coating material using SF-1 was applied to a chromium phosphate-treated aluminum plate with an applicator so that the dry film thickness was about 25 μm. It was dried at 120 ° C. for 30 minutes to prepare a test plate for the ice accretion test. Also, SF-2 to 4
A test plate was prepared by the same method.

In Comparative Example 4, a polytetrafluoroethylene film (manufactured by Nippon Bulker Co., Ltd.) was laminated (CH-1), and in Comparative Example 5, a polyvinyl fluoride film (Tedlar: manufactured by DuPont) was laminated. What was done (CH-2) was used as the test plate.

Table 4 shows the results of the measurement of the frosting shear fracture strength at initial stage, after 3 months of outdoor exposure and after immersion in running water, and the results of the physical property tests.

[0114]

[Table 4]

1) Ice Shearing Fracture Strength Test Method: On an aluminum plate coated with the above-mentioned paint for preventing ice accretion,
Place a stainless steel ring (internal area 5 cm ² ) and put it in a -10 ° C freezer test thermostat and precool for 90 minutes. Then, 2 ml of distilled deionized water kept at 5 ° C is poured into the ring to be frozen, whereby ice adhered to the surface of the specimen is obtained. After leaving this state at −10 ° C. for 2 hours, it was connected to a load cell, and the shear fracture strength at which ice was peeled off by impacting the ring with a metal operating rod was measured.

2) The evaluation criteria in the physical property tests were carried out by the following 5-point method. 5 points: No peeling of coating film at test site 4 points: Peeling area of coating film at test site is 1/20 or less 3 points: Peeling area of coating film at test site is 1/20 to 1 / 5 or less 2 points: The peeled area of the coating film at the test site is 1/5 to 1/2 or less 1 point: The peeled area of the coating film at the test site is 1/2 or more

3) 1 mm using a cutter knife for the coating film
Make 100 goggles at intervals and peel them off with cellophane adhesive tape (manufactured by Nichiban Co., Ltd.).

4) With a DuPont impact tester, the impact diameter 1 /
After applying an impact from the unpainted direction of the test plate under the conditions of 2 inches, weight weight 500g, and drop weight height 50cm, peel off the impact part with cellophane adhesive tape.

[0119]

As described above, the fluorine-containing copolymer having a silyl group and the coating composition of the present invention can be applied to the coating film appearance and coating film performance (weather resistance, water repellency, anti-icing property, paper coating). It has an effect of giving a coating film excellent in prevention property). Due to such effects, the fluorinated copolymer having a silyl group and the coating composition of the present invention are suitable for automobile coatings, anti-icing coatings and anti-sticking coatings.

[Brief description of drawings]

FIG. 1 is a diagram of IR spectrum of the polymer of Example 1.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazunori Chiba             1150 Hazawa-machi, Kanagawa-ku, Yokohama-shi, Kanagawa             Asahi Glass Co., Ltd. Central Research Laboratory

Claims (13)

[Claims] 1. A fluoroolefin polymer unit represented by formula a) is represented by 40 to 60 mol%, a silyl group-containing polymer unit represented by formula b) is represented by 0.5 to 60 mol%, and represented by formula c). Containing 0 to 55 mol% of the vinyl-based polymer unit, and 0 to 55 mol% of the polymer unit having a curing reactive site represented by the formula d).
A fluorinated copolymer having a silyl group. In the formulas (a), (b), (c) and (d), X represents fluorine, chlorine, a C1-8 perfluoroalkyl group or a C1-8 perfluoroalkoxy group. R
¹ represents hydrogen or a methyl group. R ² represents a monovalent hydrocarbon group. Y represents an organosiloxy group or a fluoroalkyl group. k represents 0 or 1. m represents an integer of 0 to 3. R ³ represents hydrogen or a methyl group. R ⁴ represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a fluoroalkyl group having 2 to 10 carbon atoms. p represents 0 or 1. q represents 0 or 1.
R ⁵ represents hydrogen or a methyl group. R ⁶ represents a divalent organic group. r represents 0 or 1. Z represents a curing reactive site. ) [Chemical 1] [Chemical 2] [Chemical 3] [Chemical 4] 2. The fluorine-containing copolymer according to claim 1, wherein the polymer unit containing a silyl group represented by the formula b) is a polymer unit based on isopropenoxytrialkylsilane. 3. The fluorine-containing copolymer according to claim 1, wherein the polymer unit containing a silyl group represented by the formula b) is a polymer unit based on vinyloxytrialkylsilane. 4. It is soluble in an organic solvent in an uncrosslinked state and has an intrinsic viscosity of 0.05 to 2.0 dl at 30 ° C. in tetrahydrofuran.
The fluorine-containing copolymer according to claim 1, which is / g. 5. A coating composition containing the fluorine-containing copolymer according to claim 1 and a curing agent. 6. A coating composition containing a curing agent in an amount of 0.5 to 300 parts by weight per 100 parts by weight of the fluorocopolymer of claim 1. 7. A coating composition containing the fluorine-containing copolymer according to claim 1, a curing agent and an ultraviolet absorber. 8. An ultraviolet absorber in an amount of 0.01 to 50 parts by weight and a curing agent in an amount of 0.5 to 30 per 100 parts by weight of the fluorine-containing copolymer of claim 1.
A coating composition contained in an amount of 0 part by weight. 9. A coating composition containing 1 to 80 parts by weight of the fluorine-containing copolymer according to claim 1 per 100 parts by weight of a film-forming resin component. 10. An ultraviolet absorber in an amount of 0.01 to 50 parts by weight and a curing agent in an amount of 0.5 to 300 parts by weight, based on 100 parts by weight of the fluorine-containing copolymer of claim 1, on an intermediate coating film formed of a synthetic resin paint. The outer panel of an automobile that has been top-coated with the coating composition contained in the ratio of. 11. A coating composition comprising 1 to 80 parts by weight of the fluorine-containing copolymer according to claim 1 per 100 parts by weight of a coating film-forming resin component on an intermediate coating film formed of a synthetic resin coating material. A car exterior panel with a top coat. 12. A composition for anti-icing paint, which comprises the fluorine-containing copolymer according to claim 1 as an essential component. 13. A composition for anti-paper-sticking paint, which comprises the fluorine-containing copolymer according to claim 1 as an essential component.