JPH02151610A - Fluorinated copolymer and use thereof - Google Patents

Abstract

PURPOSE:To make it possible to dissolve a fluorinated copolymer in a solvent at low temperatures and to improve the curability at ordinary temperatures, weathering resistance, water resistance, etc., by copolymerizing a chlorinated fluoroolefin with a vinyl ether and a specific organosilicon compound in the presence of a chlorine acceptor. CONSTITUTION:30-70mol% chlorinated fluoroolefin (e.g. CClF=CF2) is copolymerized with 20-60mol% vinyl ether (e.g. ethyl vinyl ether) and 1-25mol% organosilicon compound having an olefinically unsaturated bond and a hydrolyzable group (e.g. vinyloxypropyltrimethoxysilane) in the presence of 0.5-100g of a chlorine acceptor [e.g. Mg6Al12(OH)16CO3.4H2O] per mol of chlorine and a radical polymerization initiator at -30 to 200 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for producing a fluorine-containing copolymer that is free from coloration and can be dissolved in an organic solvent and rapidly cured at room temperature.

Technical background of the invention and its problems Weather resistance,
Paints with excellent durability are required, and high-grade exterior paints based on polyester or acrylic are used. but,
Existing paints have a short outdoor service life, and even the above-mentioned high-quality paints lose their aesthetic appearance and substrate protection effect within a few years.

On the other hand, fluoropolymers are extremely stable both thermally and chemically, and have excellent weather resistance, water resistance, chemical resistance, solvent resistance, mold releasability, low friction, and water repellency. Suitable as a surface treatment agent for various substrates. However, conventionally known fluoropolymers suffer from the above-mentioned properties,
It was difficult to form a coating film because it was soluble in organic solvents, making it extremely difficult to use it as a paint. For example, most of the currently known fluoropolymer paints are powder paints, and a small amount of pVdF (polyvinylidene fluoride) is used as an organic solvent-dispersed paint by taking advantage of its ability to dissolve in specific solvents at high temperatures. It's just being used. Moreover, these fluoropolymer paints require baking at a high temperature when forming a film, so their field of use has been limited to areas where heating equipment is available. Furthermore, the presence of heating equipment and the necessity of performing a baking process are not desirable from the viewpoint of the safety of the workers and the environment of the workplace.

Therefore, in recent years, attempts have been made to develop fluoropolymers that are solvent-soluble or do not require a baking process at high temperatures.

For example, JP-A-57-34107 discloses a quaternary copolymer consisting of fluoroolefins, cyclohexyl vinyl ethers, alkyl vinyl ethers, and hydroxyalkyl vinyl ethers, and this copolymer is soluble in organic solvents. It is also described that it can be cured at room temperature. However, in order to cure this copolymer at room temperature, a melamine-based curing agent or a urea resin-based curing agent is also required, which has the disadvantage that weather resistance is reduced accordingly. Further, the glass transition temperature of this copolymer is relatively high, at or above room temperature, that is, at or above 25°C. Furthermore, although no actual example is described in Japanese Patent Publication No. 4B-89412, an organosilicon compound having an olefinic unsaturated bond and a hydrolyzable group is added to PTFE (polytetrafluoroethylene) using an organic hydroperoxide. It has been suggested that those mechanically treated in the presence of a radical initiator such as the above are crosslinked and cured by water at room temperature. However, the fluoropolymer produced by this method is a polymer in which an organosilicon compound is grafted onto PTFE, and is substantially insoluble in organic solvents.

In view of these two current circumstances, the present inventors have developed a material that: 1) dissolves in an organic solvent at low temperatures, 2) does not require a special curing agent during curing, 2) cures at room temperature, and 2) has weather resistance after curing. As a fluorine-containing copolymer that has excellent water resistance, chemical resistance, solvent resistance, and low friction properties, and can be directly polymerized from monomer components, [A co(a) fluoroolefin, (b) vinyl ether, (c) [B] A copolymer consisting essentially of an organosilicon compound having an olefinic unsaturated bond and a hydrolyzable group, wherein the total mole of (a) to (e) in the copolymer [B] For a number, (a
): 30-70 mol%, (b): 20-60 mol%, (
c) = 1 to 25 mol%, and the number average molecular weight (Mn) measured by [C] '7' le permeation chromatography is 3000 to 2
A solvent-soluble fluorine-containing copolymer defined by 00000 and a paint obtained by dissolving this fluorine-containing copolymer in an organic solvent,
This was proposed in Japanese Patent Application No. 59-283017.

This fluorine-containing copolymer has extremely excellent properties, but (a) when a fluoroolefin containing chlorine is used as the fluoroolefin, the resulting fluorine-containing copolymer is colored yellow or the like. There was a point. Therefore, there is a problem in that a coating film obtained by coating a substrate with a coating material prepared by dissolving this fluorine-containing copolymer in an organic solvent is colored yellow.

Purpose of the Invention The present invention aims to solve the above-mentioned problems, and it is an object of the present invention to provide a fluorine-containing copolymer that is free from coloration, easily dissolves in organic solvents, and can be rapidly cured at room temperature. The purpose is to provide a manufacturing method for coalescence.

Summary of the Invention The method for producing a fluorine-containing copolymer according to the present invention comprises (a) a fluoroolefin containing chlorine, (b) a vinyl ether, and (c) an organosilicon compound having an olefinic unsaturated bond and a hydrolyzable group. When producing a fluorine-containing copolymer by copolymerization, a chlorine scavenger is present in the system during the polymerization reaction and/or during purification of the obtained copolymer.

In the present invention, when producing the above-mentioned fluorine-containing copolymer, a chlorine scavenger is present in the system during the polymerization reaction and/or during the purification of the obtained copolymer.
A colorless fluorine-containing copolymer can be obtained.

DETAILED DESCRIPTION OF THE INVENTION The method for producing a fluorine-containing copolymer according to the present invention will be specifically described below.

First, the fluorine-containing copolymer according to the present invention will be explained. This fluorine-containing copolymer consists of (a) fluoroolefin containing chlorine, (b) vinyl ether, and (c)
It is a copolymer consisting of three types of monomer component units with an organosilicon compound having an olefinic unsaturated bond and a hydrolyzable group. However, small amounts of other copolymerizable monomer components, such as α
-Olefins, cycloolefins, carboxylic acid vinyl esters, carboxylic acid allyl esters, etc. may be copolymerized.

The fluoroolefin (a) used in the present invention has at least one fluorine atom and one chlorine atom in the molecule, and preferably all hydrogen atoms of the olefin are fluorine atoms, chlorine atoms, and other halogen atoms. Substituted perhaloolefins are preferred. Furthermore, from the viewpoint of polymerizability and properties of the resulting polymer, fluoroolefins having 2 or 3 carbon atoms are preferred.

Specifically, the following compounds are used as such fluoroolefins.

C(l F-CF 5CI(cIJ-CF2, CCl
2-CF5C(l F-C(l F, CHF-C
(1, C(1?2-CCJI)F and other fluoroolefins having 2 carbon atoms (fluoroethylene type).

CF CB CF-CF , CF3CCN-CF2
, CF3CF-CFCN.

CF (l C(1-CF, CF21! CF-
CF (l 5CFi 2CF San CF2, CCD CF
-CF 5CF3CF-CHCD, CCgF C
F-CHCΩ, CCΩa CF -CHCl1, CF
]fluoroolefin (fluoropropene type) having 3 carbon atoms, such as N CF-CF2 and CHBr CF-C0g2.

CF C (1-CFCF3, CF -〇FCF2CCgF2, CF -mCFCF20CI3, CH■CFCCg2CC!13, CF (cF) CCf1 ■CF2.C
Fluoroolefins having 4 or more carbon atoms, such as F (cF2)80C1-CF2.

Among these, as mentioned above, fluoroethylene and fluoropropene are preferred, and chlorotrifluoroethylene (cCIF-CF2) is particularly preferred.

Further, in the present invention, the fluoroolefins may be used alone or in combination of two or more.

The vinyl ether (b) used in the present invention is a compound in which a hinyl group and an alkyl group, cycloalkyl group, aryl group, aralkyl group, etc. are ether bonded.

Specifically, such vinyl ethers include ethyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, butyl vinyl ether, and tert vinyl ether.
-butyl vinyl ether, pentyl vinyl ether, hexyl vinyl ether, isohexyl vinyl ether,
Chain alkyl vinyl ethers such as octyl vinyl ether, 4-methyl-]-pentyl vinyl ether, cycloalkyl vinyl ethers such as cyclopentyl vinyl ether and cyclohexyl vinyl ether, aryl vinyl ethers such as phenyl vinyl ether, and aralkyl vinyl ethers such as benzyl vinyl ether and phenethyl vinyl ether. can be used.

Among these, the number of carbon atoms is preferably 8 or less, preferably 2 to 4.
and a chain alkyl vinyl ether having 5 to 5 carbon atoms.
6 is preferred, and ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether are more preferred.

Further, in the present invention, the above-mentioned vinyl ethers may be used alone or in combination.

The organosilicon compound (e) used in the present invention is a compound having an olefinic unsaturated bond and a hydrolyzable group in the molecule, and specifically has the following formulas (1) to (3).
) can be exemplified.

R' R2Si Y1Y2 (1) R' XSI
Y' Y2 (2) R1SIY1Y2Y3
(3) (wherein, RR2 has an olefinically unsaturated bond and is composed of carbon, hydrogen, and optionally oxygen, and is the same or different group; X is an organic group having no olefinically unsaturated bond) (Y2, Y3 are the same or different hydrolyzable groups, respectively.) R1 or R2 is specifically, vinyl, allyl (al
lyl), butenyl, cyclohexenyl, cyclopentagenyl, etc., and terminal olefinically unsaturated groups are particularly preferred. Moreover, R or R2 has an ester bond of a terminal unsaturated acid, CH-〇H-0(cH2) 3 CH-C(cH)Coo (cH2) 3CH2-C(
It can also be a group such as cH3)Coo(cH2')2-0(cH2)3CB-C(cH)COOCH2CH2H. Among these, it is preferable that R and R do not contain oxygen and are composed of carbon and hydrogen, and a vinyl group is particularly suitable.

Specifically, X is a monovalent hydrocarbon group such as methyl, ethyl, propyl, tetradecyl, octadecyl, phenyl, benzyl, tolyl, etc., and these groups are
It may also be a halogen-substituted hydrocarbon group.

Specifically, YI Y and Y3 are alkoxy groups such as methoxy, ethoxy, butoxy, and methoxyethoxy, alkoxyalkoxy groups, acyloxy groups such as formyloxy, acetoxy, and propionoxy, and oximes, such as 0N-C(cHa)2, 10 These include CHCH2C2H5 and 10N-C(cOR5)2, and any other hydrolyzable organic group.

In the present invention, the organosilicon compound has the general formula (3
) is preferable, and organosilicon compounds in which the groups YI, Y2, and Y3 are the same are particularly preferable. Among these, R1 is a vinyl group, Y1 to Y3
Particularly preferred are organosilicon compounds in which is an alkoxy group or an alkoxyalkoxy group, such as vinyloxypropyltrimethoxysilane, vinyltrimethoxysilane,
Vinyltriethoxysilane, vinyltris(methoxyethoxy)silane, etc. are preferred. Furthermore, vinylmethyljethoxysilane, vinylphenyldimethoxysilane, etc. can be used similarly.

In the fluorine-containing copolymer according to the present invention, the content ratio of the heptamer components (a) to (e) is 30 to 70 moles based on the total number of moles of (a) to (e). % preferably in an amount of 40 to 60 mol %, (b) in an amount of 20 to 60 mol %, preferably 20 to 50 mol %, and (c) in an amount of 1
Desirably, the amount is from 3 to 25 mol%, preferably from 3 to 20 mol%.

Such a fluorine-containing copolymer according to the present invention can be used, at room temperature, for example, aromatic hydrocarbons such as benzene, toluene, and xylene, ketones such as acetone and methyl ethyl ketone, diethyl ether, dipropyl ether, methyl cellosolve, and ethyl ether. Ethers such as cellosolve,
It dissolves in esters such as ethyl acetate and butyl acetate, alcohols such as ethanol, and halogenated hydrocarbons such as trichloromethane, dichloroethane, and chlorobenzene.

Therefore, a coating composition can be prepared by dissolving the above-mentioned fluorine-containing copolymer in the above-mentioned organic solvent.

When preparing a coating composition from the above-mentioned fluorine-containing copolymer, it is preferable to use toluene, xylene, butyl acetate, isobutyl methyl ketone, methyl cellosolve, ethyl cellosolve, or a mixture thereof as the organic solvent. .

Such a fluorine-containing copolymer is an organosilicon compound (c)
Since it has a hydrolyzable organic group derived from , a cross-linking reaction occurs between the molecular chains of the polymer when it comes into contact with moisture, resulting in curing. Therefore, as a matter of course, moisture in the atmosphere can also cause crosslinking. It is clear that crosslinking of this fluorine-containing copolymer progresses even when used alone;
When used as a paint, a silanol condensation catalyst can be added in advance to the paint composition so that the fluorine-containing copolymer film applied to the base material is rapidly cured.
It can also be added before painting. in this case,
When an organic solvent solution containing a fluorine-containing copolymer and a silanol condensation catalyst is applied to a substrate, a curing reaction occurs as the organic solvent evaporates and comes into contact with moisture in the air, resulting in film hardening.

As the silanol catalyst, known ones can be used, and specifically, dibutyltin dilaurate, dioctyltin dilaurate, stannous acetate, stannous octoate, lead naphthenate, iron 2-ethylhexanoate, and naphthene. Carboxylic acid metal salts such as cobalt acid 1, organic bases such as ethylamine, hexylamine, dibutylamine, piperidine,
Acids such as inorganic acids and organic fatty acids are used. Among these, alkyltin carbon salts such as dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctoate, and dibutyltin diacetate are preferred.

The crosslinking reaction of the fluorine-containing copolymer according to the present invention proceeds sufficiently at room temperature, that is, around room temperature (0 to 40'C), but the reaction may be carried out under heating if necessary.

When using the fluorine-containing copolymer according to the present invention as a paint, it can be applied with a brush or spray in the same way as ordinary liquid paints.
It can be applied to the surface of base materials such as metal, wood, plastic, ceramic, paper, and glass using a roller coater or the like.

The cured film has excellent weather resistance, chemical resistance, solvent resistance, water resistance, heat resistance, and low friction, as well as excellent transparency, gloss, and elongation.

In the present invention, when producing the above-mentioned fluorine-containing copolymer, a chlorine scavenger is present in the system during the polymerization reaction, during purification of the obtained copolymer, or both.

Specifically, when copolymerizing (a) a fluoroolefin containing salt X, (b) vinyl ether, and (c) an organosilicon compound as described above, a chlorine scavenger is present in the reaction system, and When the fluorine-containing copolymer is purified using an organic solvent such as alcohol, it is preferable to have a chlorine scavenger present in the system.

As the chlorine scavenger, the following compounds can be used.

(KiM AN (OH) 2x+3y-2z (A)
ax y
zH20 (where M is Mg, C
a or Zn, A is CO3 or HPO4, X%)' SZ is a positive number, and a is 0 or a positive number. ) complex compound.

Specifically, the following compounds are used as the composite compound represented by (a).

M g A II (OH) C0・4 H2
0Mg AN (OH) C0・5H2082
20B Mg Aj) (OB) Co ・4H2
0Mg A, 11 (OH) C0・4H2
0M g A D (OH) HP 0
・4 H20Ca Al (OH) CO-
4H20Z n A g(OH) C0・4
H20 The complex compound represented by (a) may be a compound that is not exactly represented by the above formula, for example, a compound in which part of the OH of Mg l (OH) 3H20 is replaced with CO3. There may be. Further, water of crystallization may be removed from these compounds.

In such a complex compound, M is Mg and A
Compounds in which is CO3 are preferred.

(b) Basic compound of alkaline earth metal As the basic compound of alkaline earth metal, specifically, Mg 01C
a Alkaline earth metal oxides such as O, Mg(OH)
, heptalkaline earth metal hydroxides such as Ca(OH) 2 , alkaline earth metal carbonates such as MgCO 3 and CaCO 3 , and the like are used.

Basic compounds of alkaline earth metals such as those mentioned above are
(MgCO) Mg(OH) Fist 5 H20 or other double salts may be used, and these compounds may have water of crystallization removed.

Among these basic compounds of alkaline earth metals,
Mg-containing compounds are preferred.

(c) Epoxy group-containing compounds Examples of epoxy group-containing compounds include silicon-containing epoxy compounds such as γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and trimethylolpropane polyglycidyl. Aliphatic epoxy compounds such as ether and neopentyl glycol diglycidyl ether are used.

Among these, silicon-containing epoxy compounds such as γ-glycidoxypropyltrimethoxysilane are preferred.

Among the chlorine scavengers mentioned above, chlorine scavengers that are inorganic compounds react faster with chlorine (hydrochloric acid) than chlorine scavengers that are organic compounds, and they do not dissolve in polymerization or purification systems. It is preferably used because it is easy to remove from the system. Particularly preferred are the composite compounds shown in (a).

Coloring of the obtained fluorine-containing copolymer can be effectively prevented by making the above-mentioned chlorine scavenger present during the polymerization reaction, during the purification of the obtained copolymer, or both. . In particular, by allowing a chlorine scavenger to be present in the system during the polymerization reaction, coloring of the resulting fluorine-containing copolymer can be effectively prevented.

In addition, when the obtained fluorine-containing copolymer is purified with alcohol or the like, a chlorine scavenger is present in the system, and this fluorine-containing copolymer is dissolved in an organic solvent such as toluene to form a paint. When this paint is applied to a base material such as metal to form a coating film, it is possible to effectively prevent rust from forming on the base material.

When such a chlorine scavenger is used during the polymerization reaction, it is preferably used in an amount of 065 to 100 g, preferably 1 to 70 g, per mole of chlorine atoms contained in (a) fluoroolefin.

When a chlorine scavenger is used during purification, it is preferably used in an amount of 0.5 to 100 g, preferably 1 to 70 g, per 100 g of the obtained fluorine-containing copolymer.

Note that when the obtained fluorine-containing copolymer is purified with an organic solvent, it is preferable to use alcohols as the organic solvent. -butanol, 1so-butanol, tert-butanol, etc. are used.

In the present invention, the fluorine-containing copolymer can be produced according to a conventionally known method, except that the above-mentioned chlorine scavenger is present in the polymerization reaction system and/or purification system. That is, the fluorine-containing copolymer according to the present invention can be produced by copolymerizing each of the above monomers (a) to (c) in the presence of a known radical initiator. Here, each component (a) to (c) must be present; for example, copolymerization will not occur with only components (a) and (c), but adding component (b) Components (a), (b), and (c) are copolymerized by this.

When producing such a fluorine-containing copolymer, various known radical initiators can be used. Specifically, organic peroxides, organic bersesters such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoate) hexyne-3, 4-bis(tert-
butylperoxyisopropyl)benzene, lauroylperoxide, tert-butylberacetate, 2.
5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-di(t
tert-butylperoxy)hexane, tert-butylberbenzoate, tert-butylberphenylacetate), tert-butylberisobutyrate, te
rt-butylberu 5C1e-octoate, tert
-Butylbelpivalate, cumylbelpivalate, 1e
Other azo compounds such as azobis-isobutylnitrile, dimethylazoisobutyrate, etc. are used, such as rt-butylbergiethyl acetate. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-
Di(tert-butylperoxy)hexane, 1.4-
Dialkyl peroxides such as bis(tert-butylperoxyisopropyl)benzene are preferred.

The copolymerization reaction as described above is preferably carried out in a reaction medium consisting of an organic solvent. Examples of such organic solvents include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as n-hexane, cyclohexane, and n-heptane, and chlorobenzene, bromobenzene, iodobenzene, and 0-bromotoluene. Halogenated aromatic hydrocarbon, tetrachloromethane, t, t, t-
Halogenated aliphatic hydrocarbons such as trichloroethane, tetrachloroethylene, and -chlorobutane can be used.

The copolymerization reaction as described above is carried out in a solvent as described above using a radical initiator in a molar ratio of 1 to the total number of moles of monomers.
It is preferable to add in a range of 0 to 2×10 −3 . The polymerization temperature is -30 to 200°C, preferably 20 to 200°C.
The temperature is 100°C.

In order to further improve the affinity between the fluorine-containing copolymer according to the present invention and organic pigments, a carboxyl group can also be introduced into the molecular chain of the fluorine-containing copolymer. Specifically, an unsaturated carboxylic acid or a derivative thereof may be graft-polymerized onto a fluorine-containing copolymer. Unsaturated carboxylic acids used for this purpose include acrylic acid, methacrylic acid, α-ethyl acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocys-bicyclo [2,2,11hept-5-ene-2,3-dicarboxylic acid (nadic acid), methyl-endocys-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid (methyl Unsaturated carboxylic acids such as nadic acid (■), halides, amides, imides, acid anhydrides, and esters of unsaturated carboxylic acids, including maleyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, etc. There is.

The fluorine-containing copolymer thus obtained is purified by treatment with an organic solvent such as alcohol in which a chlorine scavenger coexists as described above, and then the solvent and residual monomer are removed. A copolymer is obtained. Thereafter, the obtained fluorine-containing copolymer is dissolved in an organic solvent such as xylene, solid matter is filtered, and the concentration of the organic solvent is adjusted to obtain a fluorine-containing copolymer paint.

As described above, the fluorine-containing copolymer according to the present invention is most suitable for use as a coating composition in the form of a solution in various organic solvents.

In this case, pigments or dyes may be added to the paint composition to form a colored paint, and if necessary, various additives commonly added to synthetic resins may also be added. Further, the above-described fluorine-containing copolymer may be used as a modifier for resins having alkoxysilyl groups or silanol groups, such as silylated acrylic resins, silicone paints, and silylated polyolefins.

Effects of the Invention In the present invention, when producing the above-mentioned fluorine-containing copolymer, a chlorine scavenger is present in the system during the polymerization reaction and/or during the purification of the obtained copolymer.
A colorless fluorine-containing copolymer can be obtained.

〔Example〕

The content of the present invention will be explained below using preferred examples, but unless otherwise specified, the present invention is not limited to these examples, and any embodiments are possible without impairing the purpose of the present invention. .

Example 1 The interior of a stainless steel autoclave with an internal volume of 1.5 g and equipped with a stirrer was purged with nitrogen, and 180 ml of benzene was added under a nitrogen stream.
Ethyl vinyl ether (EVE) 106g, n-butyl vinyl ether (BYE) 21.0g, )rimethoxyvinylsilane (TMVS) 62.2g, synthetic hydrotalcite (Mg4.5A[2(OH)13Co3.3.
5H20) Powder fired products (!IHT) 13. I prepared Og. Then, chlorotrifluoroethylene (cTPE)
) 257 g was introduced into an autoclave, and the temperature was raised to 65°C.

An initiator solution prepared by dissolving 7.6 g of dilauroyl peroxide in 120 cc of benzene was fed to the mixture obtained as described above over 4 hours.

After further reacting at 65° C. for 6 hours, the autoclave was cooled with water to stop the reaction.

After cooling, unreacted monomers are expelled, the autoclave is opened, and 1. The reaction solution was taken out into a 1" eggplant-shaped flask.

In this reaction solution, 210 g of xylene, 120 g of methanol,
5H713,Og was added and further heated at 50°C for 1.5 hours.
Heat treatment was performed at 0° C. for 1.5 hours with stirring.

After the treatment, residual monomers and solvent were distilled off under reduced pressure using an evaporator, and then 550 g of xylene was added and stirred to form a homogeneous solution.

This solution was filtered to remove SHT and concentrated under reduced pressure to obtain 366 g of a colorless and transparent polymer.

The number average molecular weight of the obtained polymer by GPC was 10.
It was 000.

In addition, the composition analysis of this copolymer was carried out by elemental analysis and NMR.
CTFE/EVE/BVE/
TMVS-50/37/6/7 (molar ratio).

The degree of coloring of the fluorine-containing copolymer thus obtained was 6.4 when the absorbance of light at a wavelength of 420 nm, which is a complementary color to yellow, was measured as follows.

Absorption measurement method for light with a wavelength of 420 nm> 100 parts by weight of a fluorine-containing copolymer is dissolved in 100 parts by weight of xylene to prepare a resin solution.

On the other hand, Multlpurpose Recordlng
5pectrophotos+eter MPS-20
00 (manufactured by Shimabara Seisakusho),
20 Measure the absorbance of RV light.

Next, the absorption of the resin solution was examined, and the value obtained by subtracting the absorption of xylene from this was taken as the absorbance of the resin.

In addition, in this measurement, the absorbance and visual coloring degree judgment (
The approximate relationship with Gardner No.) is shown below.

Gardner No. 1 Absorbance 50X10-3 Gardner N092 Absorbance 100X10-3 Example 2 A copolymer was obtained in the same manner as in Example 1 by changing the amount of the hydrochloric acid scavenger. The amount of hydrochloric acid scavenger and the degree of coloration of the polymer are shown in Table 1.

Example 3 After the polymerization reaction in Example 1, the following operations were performed after opening the autoclave: 210 g of xylene was added, the residual monomer and solvent were distilled off under reduced pressure using an evaporator, and then 550 g of xylene was added. A homogeneous solution was obtained by stirring. This solution was filtered to remove SHT and concentrated under reduced pressure to obtain a copolymer.

Table 1 shows the degree of coloration of the obtained polymer.

Examples 4 to 8 Copolymers were obtained by changing the type and amount of the hydrochloric acid scavenger and the amount of alcohol added during purification in Example 1. Table 1 shows the type and amount of the hydrochloric acid scavenger, the amount of alcohol added, and the degree of coloration of the obtained copolymer.

Example 9 Using the same polymerization apparatus as in Example 1, the inside of the apparatus was replaced with nitrogen, and 180 ml of benzene, 106 g of ethyl vinyl ether (EVE), and n-butyl vinyl ether were added under a nitrogen stream.
BYE 21.0g,) ethoxyvinylsilane (TEVS) 79. 9 g, synthetic hydrotalcite (Mg AIJ (OH) 13CO34,5
2 3,5H20) Powder fired products (SIIT) 13.
I prepared Og. Thereafter, 257 g of chlorotrifluoroethylene (cTFE) was introduced into the autoclave, and the temperature was raised to 65°C.

An initiator solution prepared by dissolving 7.6 g of dilauroyl peroxide in 120 cc of benzene was fed to the mixture obtained as described above over 4 hours.

After further reacting at 65° C. for 6 hours, the autoclave was cooled with water to stop the reaction.

After cooling, unreacted monomers were expelled, the autoclave was opened, and the reaction solution was taken out into a 1.5N eggplant flask.

To this reaction solution, 210 g of xylene and 1.73 g of ethanol were added.
g, 5HTi3. After adding Og, the mixture was heated at 50°C for 1.5 hours and then at 60°C for 1.5 hours with stirring.

After the treatment, residual monomers and solvents were distilled off under reduced pressure using an evaporator, and then 550 g of xylene was added and stirred to form a homogeneous solution.

This solution was filtered to remove SHT and concentrated under reduced pressure to obtain 406 g of a polymer.

Table 1 shows the degree of coloration of the copolymer.

Example 10 Using the same polymerization apparatus as in Example 1, the inside of the apparatus was replaced with nitrogen, and 180 ml of benzene was added under a nitrogen stream. Ethyl vinyl ether (EVE) 106 g, n-butyl vinyl ether (BVE) 21. 0 g, 3-hi=o-t-
Dipropyltrimethoxysilane (VoPTMS) 86
．． 6g1 synthetic hydrotalcite (Mg AlF2
．． 52 (OH) C0・3.5H20) Powder fired product (SI
IT) 13. 0 g was charged. Thereafter, 257 g of chlorotrifluoroethylene (cTFE) was introduced into the autoclave, and the temperature was raised to 65°C.

An initiator solution prepared by dissolving 7.6 g of dilauroyl peroxide in 120 cc of benzene was fed to the mixture thus obtained over 4 hours.

After further 9 reactions at 65° C. for 6 hours, the autoclave was cooled with water to stop the reaction.

After cooling, remove the unreacted upper part, open the autoclave, and proceed as follows: 1. The reaction solution was taken out into a 1.5-liter eggplant-shaped flask.

To this reaction solution, add 210 g of xylene and 120 g of methanol.
, 5HT13. The mixture was heated at 50° C. for 1.5 hours and then at 60° C. for 1.5 hours with stirring.

After the treatment, residual monomers and solvent were distilled off under reduced pressure using an evaporator, and then 550 g of xylene was added and stirred to form a homogeneous solution.

This solution was filtered to remove 5I(T) and concentrated under reduced pressure to obtain 448 g of a polymer.

Table 1 shows the degree of coloration of the copolymer.

Comparative Example 1 Using the same polymerization apparatus as in Example 1, the inside of the apparatus was replaced with nitrogen, and 180 ml of benzene was added under a nitrogen stream. Ethyl vinyl ether (EVE) 106 g, n-butyl vinyl ether (BYE) 21° Ogl Trimethoxyvinyl silane (TMVS) 62. 2 g was added. after that,
257 g of chlorotrifluoroethylene (cTPE) was introduced into the autoclave, and the temperature was raised to 65°C.

Add 7 o peroxide to the mixture thus obtained.
An initiator solution prepared by dissolving 7.6 g of chlorine in 120 cc of benzene was fed over 4 hours.

After further reacting at 65° C. for 6 hours, the autoclave was cooled with water to stop the reaction.

After cooling, unreacted monomers were expelled, the autoclave was opened, and the reaction solution was taken out into a 1.5N eggplant-shaped flask, and the residual monomers and solvent were distilled off under reduced pressure using an evaporator to obtain 380 g of a copolymer.

Table 1 shows the degree of coloration of the obtained copolymer.

Claims (1)

[Claims] 1. A fluorine-containing copolymer by copolymerizing (a) a fluoroolefin containing chlorine, (b) a vinyl ether, and (c) an organosilicon compound having an olefinic unsaturated bond and a hydrolyzable group. 1. A method for producing a fluorine-containing copolymer, characterized in that a chlorine scavenger is present in the system during the polymerization reaction and/or during purification of the obtained copolymer. 2. The chlorine scavenger is M_xAl_y(OH)_2_x_
+_3_y_-_2_z(A)_z・aH_2O (where M is Mg, Ca or Zn, A is CO_3 or HPO_4, x, y, z are positive numbers, a is 0
or a positive number) Claim 1
A method for producing a fluorine-containing copolymer as described in 2. 3. The method for producing a fluorine-containing copolymer according to claim 1, wherein the chlorine scavenger is a basic compound of an alkaline earth metal. 4. Claim 1, wherein the chlorine scavenger is an epoxy-containing compound.
A method for producing a fluorine-containing copolymer as described in 2.