JPH03217409A - Fluorine-containing polymer and fluorocoating containing the same as main component - Google Patents

Abstract

PURPOSE:To provide the subject polymer having a specific number-average mol.wt., soluble in organic solvents and capable of being cured at ordinary temperature by polymerizing a fluoroolefin, a specific unsaturated group- containing phthalate ester and a hydroxyl group-containing unsaturated ether in a specific ratio. CONSTITUTION:10-50mol% of a fluoroolefin (preferably tetrafluoroethylene), 5-75mol% of an unsaturated group-phthalate ester of formula I (R is H, methyl, etc.; X is fluorine, chlorine, etc.; n is 0-3; m is 0-4) (preferably diallyl phthalate) and 3-40mol% of a hydroxyl group-containing unsaturated ether of formula II (R<1> is 1-6C alkylene; l is 0 or 1) (preferably 4-hydroxyethyl vinyl ether) are polymerized to provide the objective polymer having a number-average mol.wt. of 1000-200000 and giving coating films having excellent lusters and hardness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel fluoropolymer and a fluorine-based paint containing the same as a main component.

More specifically, the present invention provides a fluorine-containing polymer that is soluble in an organic solvent, has good compatibility with a curing agent, and can be cured at room temperature, and a glossy fluorine-containing polymer containing this polymer as a main component. The present invention also relates to a fluorine-based paint that can provide a coating film that is hard and has excellent weather resistance.

[Prior Art] Conventionally, fluoropolymers have been widely used in many fields because of their extremely excellent heat resistance, mechanical properties, chemical resistance, weather resistance, and the like. One of its uses is in the coating field. For example, coating materials using tetrafluoroethylene polymers and vinylidene fluoride polymers are known, and these materials have excellent lubricity, non-stick properties, weather resistance, and chemical resistance, so they are used in the chemical industry. , used in fields such as food, architecture, and machinery.

However, the fluorine-containing polymer is insoluble in solvents or soluble only in a limited number of special solvents, so it is usually used as a powder, which inevitably limits its range of use. In recent years, attempts have been made to develop solvent-based paints using fluorine-containing polymers that are soluble in organic solvents and have reactive groups that can be cured at room temperature.

In order to solubilize a fluoropolymer in an organic solvent, it is necessary to disrupt the crystallinity of the fluoropolymer and internally plasticize it by introducing an appropriate copolymer component.
As such examples, various polymers have been disclosed so far (Japanese Patent Application Laid-open Nos. 61-275311 and 81-5).
No. 7809, No. 132-174213, No. 6
3-11112312).

However, these polymers are insufficient in terms of compatibility with curing agents, and paints based on these polymers do not have acrylic resin as the main component, which is known as conventional weather-resistant paint. The drawback is that the resulting coating film is inferior in gloss and hardness compared to other paints.

[Problems to be Solved by the Invention] The present invention overcomes the drawbacks of conventional fluorine-containing polymers that are soluble in organic solvents, and provides novel room-temperature curable polymers that have good compatibility with curing agents. The purpose of this invention is to provide a fluorine-containing paint containing a fluorine-containing polymer as a main component and capable of providing a glossy, hard coating film with excellent weather resistance.

[Means for Solving the Problems] The present inventors have conducted intensive research to develop a fluorine-containing polymer having the above-mentioned preferable properties and a fluorine-based paint containing this polymer as a main component. This objective can be achieved by a fluoropolymer containing a unit with a specific structure containing two unsaturated groups and a specific hydroxyl group-containing unsaturated ether unit as essential constituent units, each in a predetermined proportion. Based on this finding, we have completed the present invention.

That is, the present invention provides (A) fluoroolefin unit 1
0 to 60 mol%, (B) general formula (X). [In the formula, R is hydrogen or a methyl group; Unit 5 ~
75 mol% and (C) represented by the general formula Cth-CH (CH2) 1-OR'-OH (in the formula, R1 is an alkylene group having 1 to 6 carbon atoms, and l is the number of 0 or 1) The number average molecular weight (M
The present invention provides a fluorine-containing polymer characterized in that n) is 1000 to 200,000, and a fluorine-containing paint containing this fluorine-containing polymer as a main component.

The present invention will be explained in detail below.

In the polymer of the present invention, the fluoroolefin forming the unit (A) is an olefin having at least one fluorine atom in the molecule, and preferably all hydrogen atoms of the olefin are fluorine atoms and other fluorine atoms. Examples include perhaloolefins in which the halogen atom is substituted.

Further, from the viewpoint of polymerizability and properties of the resulting polymer, fluoroolefins having 2 or 3 carbon atoms, particularly barhaloolefins, are preferred.

Specific examples of such fluoroolefins include CFH
=CH2, CF2 -CH2, CF2=CFHSCF
Examples include fluoroolefin compounds having 4 or more carbon atoms such as fluoroethylene compounds such as 2-CF2 and CF2=CFCI, fluoropropene compounds such as CF2-CFCF3, and CF2-CFCF2CF3, among which fluoroethylene compounds and fluoropropene compounds are preferred, especially tetrafluoroethylene (
CF2-CF2), chlorotrifluoroethylene (C
F2-CFC I) and hexafluor open mouth pen (
CF2-CFCF3) is preferred. These fluoroolefins may be used alone or in combination of two or more.

In the polymer of the present invention, the content of units formed from the fluoroolefin needs to be in the range of 10 to 60 mol%, preferably 35 to 55 mol%.

If the content is less than 10 mol %, the properties of the fluoropolymer, such as weather resistance, will be insufficient, and if it exceeds 60 mol %, the solubility in organic solvents and gloss will decrease.

In the polymer of the present invention, the monomer forming the unit (B) is represented by the following general formula.

(X) In the formula (X), R is hydrogen or a methyl group, X is fluorine, chlorine, bromine, or a hydrocarbon group having 1 to 4 carbon atoms, and n is 0 to 4.
3. m is an integer from 0 to 4.

When two or more hydrogen atoms bonded to the benzene nucleus are substituted, the substituents may be the same or different.

Examples of the hydrocarbon group having 1 to 4 carbon atoms include methyl group,
Examples include ethyl group, probyl group, butyl group, isopropyl group, and isobutyl group.

Such monomers are phthalic acid esters containing two unsaturated groups, and there are 〇 monomers, m monomers, and p monomers.

When such a monomer is used as a copolymerization component, it generally undergoes gelation as the polymerization progresses and becomes insoluble in organic solvents, so various considerations must be taken during polymerization. From this point of view, the monomers are preferably monolithic, and n is an integer of O to 3. Preferred specific examples of such monomers include vinyl esters such as divinyl phthalate and divinyl isophthalate, allyl esters such as diallyl phthalate and diallyl isophthalate, and isopropylene esters such as diisobrobenyl phthalate and diisobrobenyl isophthalate. Benyl esters can be mentioned, but among these,
Diallyl phthalate is particularly preferred from the standpoint of polymerization controllability and economy. These monomers may be used alone or in combination of two or more.

In the polymer of the present invention, the content of the (B) units is 5
-75 mol%, preferably 5-55 mol%. If this content is less than 5 mol 96,
Poor compatibility with hardener, gloss and stiffness, 75 mol%
Exceeding this will reduce weather resistance.

In the resin of the present invention, the hydroxyl group-containing unsaturated ether forming the unit (C) is general 2CH2-
It is a compound represented by OH-(CH 2 ), -0-R'-OH. In the formula, 1 is 0 or 1, and R+ is an alkylene group having 1 to 6 carbon atoms.

Examples of such alkylene groups include methylene group, ethylene group, trimethylene group, brobylene group, butylene group, isobutylene group, and t-butylene group. Specific examples of the hydroxyl group-containing unsaturated ether include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, ethylene glycol monoallyl ether, etc. Among these, those having a vinyl group are similar to fluoroolefins. 4-hydroxybutyl vinyl ether is particularly preferred because of its good reactivity. These hydroxyl group-containing unsaturated ethers may be used alone, or
You may use two or more types in combination.

In the polymer of the present invention, the content of (C) units is from 3 to
It is necessary that the amount is 40 mol%, preferably in the range of 5 to 25 mol%. If the content is less than 3 mol%, the crosslinking curing time will be long and the chemical resistance, solvent resistance, stain resistance, etc. of the coating film will be insufficient, and if it exceeds 40 mol%, the solvent solubility of the resin will be reduced. In addition, when mixed with a curing agent, the gelation time becomes shorter, and the coating properties and workability of the paint decrease.

The polymer of the present invention has the above-mentioned specific amounts of (A), (B), and (C) units as essential constituent units, thereby improving its solubility in solvents and being curable at room temperature. Is it possible to form a coating film with particularly high gloss and hardness?In addition to these units, other copolymerizable monomers may be added within a range not exceeding 40 mol% depending on the purpose of use. It can also include body units.

Examples of the copolymerizable monomers include olefins such as ethylene, propylene, and isobutylene, normal olefins such as vinyl chloride and vinylidene chloride, and carboxylic acid vinyl esters such as vinyl acetate and vinyl n-butyrate. Carboxylic acid isobrobenyl esters such as isobrobenyl acetate and isopropenyl propionate, ethyl vinyl ether, probyl vinyl ether, isobrobyl vinyl ether, butyl vinyl ether, jerj-butyl vinyl ether, benzyl vinyl ether, hexyl vinyl ether, isohexyl vinyl ether, octyl vinyl ether, 4 - Chain alkyl vinyl ethers such as methyl-1-pentyl vinyl ether, cycloalkyl vinyl ethers such as cyclopentyl vinyl ether and cyclohexyl vinyl ether, aryl vinyl ethers such as phenyl vinyl ether, o-, m-, and p-tolyl vinyl ether, penzyl vinyl ethers , aralkyl vinyl ethers such as phenethyl vinyl ether, styrene, aromatic vinyl compounds such as vinyltoluene, silane compounds having a hydrolyzable silyl group and unsaturated bonds such as vinyltrimethoxysilane and allyltriethoxysilane, fumaric acid, maleic acid di- or monoesters and acid anhydrides of unsaturated bond-containing polybasic acids such as esters of acrylic acid and methacrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, methyl methacrylate, glycidyl methacrylate, acrylamide, N-methylol Examples include acrylamides such as acrylamide, allyl ethers such as allyl glycidyl ether and ethyl allyl ether, carboxylic acid allyl esters such as allyl acetate and allyl propionate, and allyl alcohol. Among these, carboxylic acid vinyl esters and vinyl ethers are particularly preferred because they have good reactivity with fluoroolefins.

One type of these copolymerizable monomers may be used, or two types of these copolymerizable monomers may be used.
You may use combinations of more than one species.

The molecular weight of the fluoropolymer of the present invention is the number average molecular weight ( Mn
) is 101) 0 to 200,000, preferably 200
Must be in the range 0 to 100,000. If the number average molecular weight (M n ) deviates from the above range, the object of the present invention cannot be fully achieved.

The fluoropolymer of the present invention is characterized by the presence of unsaturated groups in the polymer. The unsaturated group is derived from the (B) unit, and it is preferable in the present invention that the residual rate of the unsaturated group in the (B) unit in the fluoropolymer is in the range of 10 to 50%. .

If the unsaturated group residual rate is less than 10%, branched structures and three-dimensional crosslinked structures increase in the polymer, resulting in a decrease in the solubility of the polymer in solvents and a decrease in the number of cured sites during thermosetting. This results in a decrease in physical properties. On the other hand, in the case of a linear polymer that is not crosslinked at all, it is 50%. This means that impurities having unsaturated groups other than the polymer, such as unreacted monomers, are present in an amount exceeding 50%, which causes a decrease in physical properties. The residual rate of unsaturated groups in the polymer is determined by measuring the infrared absorption spectra of the polymer and monomer (B), and determining the peak of the carbon-carbon double bond (1850 country 1) and the peak of the benzene nucleus in each. (1B
00 cm-') can be calculated using the following equation.

Unsaturated group residual rate (%) − f(a/b)/(c/d
)) x 100a: 165 according to IR measurement of the polymer
Absorbance b at 0 cm-': 18 by IR measurement of the polymer
Absorbance at 00 cm-' C: Absorbance at 1650 cm-' by IR measurement of the monomer of the (B) unit of the polymer d: 1 by IR measurement of the monomer of the (B) unit of the polymer
Absorbance at 600 cm-' The fluoropolymer of the present invention having such a composition and molecular weight is soluble in organic solvents and has excellent compatibility with curing agents, and is also effective in curing paints containing the polymer as a main component. The coating film is glossy, hard, and has excellent weather resistance. The fluoropolymer of the present invention can be produced by copolymerizing a monomer mixture at a predetermined ratio in the presence or absence of a solvent using a polymerization initiator, ionizing radiation, etc. as a polymerization initiation source. I can do it.

As the polymerization initiator, a water-soluble one or a water-soluble one can be used as appropriate depending on the type of polymerization and the type of solvent used as desired.

Examples of water-soluble polymerization initiators include persulfates such as potassium persulfate, hydrogen peroxide, or redox initiators consisting of a combination of these and a reducing agent such as sodium bisulfite or sodium thiosulfate. Inorganic initiators with small amounts of iron, ferrous salts, silver nitrate, etc., dibasic acid peroxides such as disuccinic acid peroxide, diglutaric acid peroxide, monosuccinic acid peroxide, azobisisobutyramidine dibasic acid salt, etc. Examples include organic initiators.

Examples of oil-soluble initiators include peroxy ester type peroxides such as t-butyl peroxy isobutyrate and t-butyl peroxy acetate, dialkyl peroxy dicarbonates such as diisopropyl peroxy dicarbonate, and penzoyl peroxy dicarbonates. Examples include oxide, azobisisobutyronitrile, and the like.

The amount of these polymerization initiators to be used is appropriately selected depending on the type thereof, copolymerization reaction conditions, etc., but is 0.005 to 5% by weight, preferably 0.005 to 5% by weight, based on the total amount of monomers normally used.
It is selected in the range of 0.05% to 0.5%.

There are no particular restrictions on the polymerization method; for example, bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization, etc. can be used; In terms of ease, emulsion polymerization in an aqueous medium, solution polymerization using alcohols such as t-butanol, esters, saturated halogenated hydrocarbons having one or more fluorine atoms, etc. A bulk polymerization method that does not require separation is preferably used.

When copolymerizing in an aqueous medium, a suspending agent or emulsifier is usually used as a dispersion stabilizer, and a basic buffer is added to adjust the OpH value of the reaction solution during polymerization to 4, preferably 6 or higher. This is desirable.

Further, addition of a basic substance is also effective in the case of solution polymerization method and bulk polymerization method. Furthermore, there are no particular limitations on the polymerization format, and any of the batch, semi-continuous, and continuous methods can be used.

The reaction temperature in the copolymerization reaction is usually -30 to +15
Within the range of 0°C, it is appropriately selected depending on the polymerization initiation source and the type of polymerization medium. For example, when copolymerization is carried out in an aqueous medium, the temperature is usually 0 to 100°C, preferably 10 to 90°C. To be elected. In addition, there is no particular restriction on the reaction pressure, but it is usually 1 to 100 kg/c, preferably 2 to 50 kg/c.
/cd. Furthermore, the copolymerization reaction can be carried out by adding a suitable chain transfer agent.

The fluoropolymer of the present invention contains a hydroxyl group and an unsaturated group as a curing site, and can be used with curing agents used in ordinary thermosetting acrylic paints, such as melamine curing agents, urea resin curing agents, and polyurethane resin curing agents. It can be cured by heating using a basic acid curing agent or the like.

Examples of the melamine curing agent include butylated melamine, methylated melamine, epoxy-modified melamine, etc., and those with various degrees of modification are used depending on the purpose, and the degree of self-condensation can also be selected as appropriate. Examples of urea resin curing agents include methylated urea resins and butylated urea resins, and examples of polybasic acid curing agents include long-chain aliphatic dicarboxylic acids, aromatic polycarboxylic acids, and acid anhydrides thereof. Examples include. Furthermore, blocked polyvalent isocyanates can also be suitably used as curing agents. Further, when using a melamine curing agent or a urea resin curing agent, curing can be accelerated by adding an acidic catalyst.

Furthermore, the fluoropolymer of the present invention can also be cured at room temperature using polyvalent isocyanates. Preferred examples of the polyvalent isocyanates include non-yellowing diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, adducts thereof, and polyvalent isocyanates having an isocyanurate ring. Among these, fluorine-containing polymers are particularly preferred. A polyvalent isocyanate having an isocyanurate ring with good compatibility with the isocyanurate ring is preferred. When curing at room temperature using these polyvalent isocyanates, a known catalyst such as dibutyltin laurate can be added to accelerate curing. The present invention provides a fluorine-based paint containing the fluorine-containing polymer as a main component, as well as the above-mentioned fluorine-containing polymer, and various solvents can be used to make the fluorine-containing polymer into a solution type paint. be able to.

Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, alcohols such as n-butanol, ketones such as methyl isobutyl ketone, glycol ethers such as ethyl cellosolve, and various commercially available thinners. It will be done. Solutions obtained by dissolving the fluoropolymer in these solvents are colorless and transparent.

The solution-type paint is prepared by mixing the fluoropolymer and a solvent using a ball mill, paint shaker sand mill, etc.
This can be carried out by homogeneous mixing using a mixer commonly used for preparing paints, such as a jet mill, three-roll mill, or kneader. At this time, pigment,
Dispersion stabilizers, viscosity modifiers, leveling agents, antigelation agents, ultraviolet absorbers, etc. can also be added.

In addition, when a paint containing the fluoropolymer as a main component is used as a so-called baking paint that cures under heat, melamine, urea resin, polybasic acids and their anhydrides, and blocked polyvalent isocyanates are usually used during the mixing. It is used as a one-component paint by blending hardening agents such as peroxides and peroxides.

On the other hand, in the case of room-temperature curing paints, unblocked polyvalent isocyanates are usually used as curing agent components.
A curing agent liquid containing this curing agent component is separately prepared and used as a two-component paint.

In this case, by appropriately selecting the type and amount of polyvalent isocyanates and catalysts, the concentration of the fluorine-containing copolymer, the content of unsaturated ethyl units containing hydroquine groups in the copolymer, etc. It has a pot life of about 1 hour,
Moreover, it can be made into a paint that cures at room temperature in several hours to several days and provides a coating film with good physical properties.

Furthermore, the fluorine-based paint of the present invention containing the fluoropolymer as a main component can provide a glossy, hard, and weather-resistant coating film under mild conditions, and can be applied to, for example, colored aluminum plates, aluminum sashes, etc. As a baking paint for
Alternatively, it is useful as an air-drying paint that can be applied on-site.

Furthermore, regarding the material of the base material, including metal materials, inorganic materials such as glass and concrete, FRP, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, nylon, acrylic resin, polyester, ethylene-polyvinyl alcohol copolymer, It is suitably used for coating plastics such as polyvinyl chloride and polyvinylidene chloride, and organic materials such as wood. The fluorine-based paint is also useful in specific applications such as aluminum boules, exterior colored glass, and cement roofs.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these examples.

Example 1 After deaeration, 13 g of diallyl phthalate (hereinafter abbreviated as DAP), 13 g of 4-hydroxybutyl vinyl ether (hereinafter abbreviated as HBVE), and 1 chlorotrifluoroethylene (hereinafter abbreviated as HBVE) were placed in a stainless steel autoclave with an internal volume of 1 liter and equipped with a stirrer. 268 g of methyl isobutyl ketone (hereinafter abbreviated as MIBK) and t-butyl baroxypiparate (NOF ■ product)
5g of Herb Chill PVJ) was added, and the internal temperature was raised to 60°C while stirring. Thereafter, the reaction was continued while stirring, and after 8 hours, the stirring was stopped and unreacted monomers were purged to terminate the reaction.

The autoclave was opened and the reaction solution was taken out. After concentration, it was reprecipitated with methanol and washed to obtain a polymer. The yield of the obtained polymer was 84 g. The compositional analysis of this polymer was performed using elemental analysis, IR analysis, and OH value measurement. CTFE/DAP/HBVE-42/44/1
4 (molar ratio). Further, the number average molecular weight of this polymer was 11,000, and the residual rate of unsaturated groups was 33%. This polymer log was dissolved in 11.5 g of MI B K, and 1.5 g of Duranate TPAJ (manufactured by Asahi Kasei Corporation) was added as a hardening agent and mixed. This solution was applied to a white tile board and After coating on the glass plate, dry at room temperature for 30 minutes, then 1
Heated at 20°C for 1 hour. After heating, place it on the cooled board.
A robust and transparent coating film was obtained that was not corroded even when wiped with MIBK having a thickness of approximately 100 μl. JISK54 of this coating film
The surface gloss according to 00 is 94% at 60° specular reflection, and the konig hardness according to ISO-1522 is 140.
Met.

Examples 2 to 7 Polymers were produced in the same manner as in Example 1 using the types and amounts of monomers shown in Table 1.

The yield, molecular weight, composition ratio, unsaturated group residual rate of the obtained polymer, and surface gloss formed in the same manner as in Example 1, ko
The njg hardness is shown in Table 1.

Table 1 Comparative Examples 1 to 4 Polymers were produced in the same manner as in Example 1 using the types and amounts of monomers shown in Table 2.

The yield, molecular weight and composition ratio of the obtained polymer, and the surface gloss of the coating film formed in the same manner as in Example 1, k6nig
The hardness is shown in Table 2.

Table 2: Carboxylic acid vinyl ester having an alkyl group having 8 carbon atoms (trade name: VEOVA-9, manufactured by Shell Chemical Co., Ltd.) [Effects of the invention] As explained above, the fluorine-containing polymer of the present invention has good solubility in organic solvents, good compatibility with curing agents, can be cured at room temperature, and can form coating films with excellent gloss and hardness.

[Brief explanation of drawings]

The attached drawing is an IR absorption spectrum diagram of the polymer obtained in Example 1.

Claims (2)

[Claims] (1) (A) Fluoroolefin units 10 to 60 mol%
, (B) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [R in the formula is hydrogen or methyl group, X is fluorine, chlorine,
bromine or a hydrocarbon group having 1 to 4 carbon atoms, n is an integer of 0 to 3, m is an integer of 0 to 4) units 5 to 7
5 mol% and (C) general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 is an alkylene group with 1 to 6 carbon atoms, l is 0
or 1) as an essential constituent unit, and has a number average molecular weight (@M@n) of 1000 to 2 as an essential constituent unit.
00,000. (2) A fluorine-based paint containing the fluorine-containing polymer according to claim (1) as a main component.