JPH0258555A - Production of fluorine-containing copolymer - Google Patents

Abstract

PURPOSE:To obtain a homogeneous fluorine-containing copolymer suitable as a raw material for a fluororesin paint, etc., in high yield by copolymerizing a hydroxyl-containing olefin with vinyl ether monomer and a fluoroolefin in a specific solvent. CONSTITUTION:The objective copolymer can be produced by polymerizing (A) a hydroxyl-containing olefin, (B) a vinyl ether composition composed of a vinyl ether of formula I (R<1> is 2-10C bivalent aliphatic group; R<2> is bivalent organic group; M is alkali metal, etc.; n is 0 or 1) and a vinyl ether of formula II wherein the content of the compound of formula I is >=1mol% based on the compound of formula II or a monomer of formula III (Y<1>-Y<3> are halogen, etc.; a is 0 or 1-6) and (C) a fluoroolefin in the presence of (D) a mixed solvent produced by mixing a 3-20 ketone solvent with an alcohol solvent of formula IV (Y<4> is 1-8C alkyl; Y<5> is H, etc., l is 0 or 1-20) at a specific ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a fluorine-containing copolymer containing a carboxyl group, which is useful as a raw material for fluororesin paints.

[Prior Art and its Problems] A fluororesin having a carboxyl group can be produced by copolymerizing a vinyl ether having a carboxyl group with a fluoroolefin, but a vinyl ether having a carboxyl group is difficult to synthesize. For example, if you attempt to synthesize a vinyl ether with a carboxyl group by reacting a hydroxyalkyl vinyl ether with a tribasic acid anhydride (half esterification), the carboxyl group and vinyl group will react and cyclize within the molecule, resulting in the desired goal. I can't look around for things.

Therefore, a fluorine-containing copolymer containing a carboxyl group can be obtained by, for example, producing a copolymer of a hydroxyl-containing vinyl ether and a fluoroolefin, and then combining the hydroxyl group contained in the copolymer with a tribasic acid anhydride. Method for reacting (half-esterifying) substances (Special Publication 1986)
-49323). but,
In this method, copolymerization is followed by 1-phesterification, so there is a problem in that it is difficult to use inexpensive alcohols that react with tribasic acid anhydrides as a solvent for copolymerization.

As a result of intensive studies on the production method of vinyl ether containing a carboxyl group, the present inventors found that when reacting a hydroxyalkyl vinyl ether with a tribasic acid anhydride,
When a basic compound is present in the system, intramolecular cyclization reaction does not occur, and the carboxyl group of the obtained vinyl ether takes the form of a salt of the basic compound, improving stability. It has been found that the yield is significantly improved when copolymerized. Further, as the carboxyl group-containing olefin, a half ester of allyl alcohol and a tribasic acid anhydride or a monovinyl ester of a tribasic acid anhydride can also be used.

By the way, when such a carboxyl group-containing fluorine-containing copolymer useful as a cross-layer paint or an electrodeposition paint is to be polymerized, it is necessary to use a polymerization solvent that is soluble in water or has excellent dispersibility. There is.

Among these solvents, amide solvents such as dimethylformamide and dimethylacetamide, and ester solvents such as methylcellosolve acetate generate miscellaneous ions in aqueous solutions, which may impair the stability of the copolymer when it is made water-soluble or generate ions. It may cause wrinkles or cracks in the appearance of the paint film. In addition, alcohol solvents such as methanol, ethanol, and isopropanol impair the stability of vinyl ether monomers due to the action of their hydroxyl groups, and also cause a decrease in the polymerization rate, resulting in similar effects to amide and ester monomers. This causes paint film defects. Furthermore, gelation occurs when a ketone solvent such as acetone or methyl ethylene ketone is used alone. Such a decrease in coating film performance becomes more noticeable when a fluorine-containing polymer is used as an electrodeposition coating.

[Means to solve the problem]

The present invention has been made to solve such problems, and includes a captive hydroxy group-containing olefin, (B1 formula (I): CHz=CHOR'0C(=O)R2C('O)O(H
) nM (I) (wherein R1 is a divalent aliphatic group having 2 to 10 carbon atoms, R2 is a divalent organic group, and M is an alkali metal or a compound containing a nitrogen or phosphorus atom. vinyl ether (hereinafter referred to as vinyl ether (II1)) in which the carboxyl group is in the form of a salt, represented by ) and formula (II): a vinyl ether having a free carboxyl group (hereinafter referred to as vinyl ether cap) represented by the formula (in the formula, R1 and R2 are the same as above), and vinyl ether (II) A vinyl ether monomer composition containing 1 mol% or more of vinyl ether (I), or a vinyl ether monomer composition of formula l;
is O or an integer of 1 to 6, R2 is the same as above) and (C) fluoroolefin are copolymerized with a ketone solvent having 3 to 20 carbon atoms; , Y4 is an alkyl group having 1 to B carbon atoms, Y5 is a hydrogen atom or a methyl group, Ω is O or an integer from 1 to 20), and a mixed solvent with an alcoholic solvent is used as the polymerization solvent. The present invention relates to a method for producing a characteristic fluorine-containing copolymer.

[Preferred Embodiment] The hydroxy group-containing olefin holes used in the present invention include 4-hydroxybutyl vinyl ether, 2-hydroxyethyl vinyl ether, 3-hydroxy-n-propyl vinyl ether, 2-hydroxy-1so-propyl vinyl ether, 2-hydroxy -2-Methyl ethyl vinyl ether, 2-hydroxy-1,1 dimethyl vinyl ether, 4-hydroxycyclohexyl vinyl ether, 3-hydroxycyclohexyl vinyl ether, 2
-hydroxycyclohexyl vinyl ether, 4-hydroxybenzooxyvinyl, 2-hydroxyethyl methacrylate, 2-hydroxypropyl α-chloroacrylate, allyl alcohol, and the like.

As mentioned above, among the components (B) used in the present invention, the vinyl ether monomer composition has significantly improved storage stability compared to the case where vinyl ether (II) is used alone. The reason is that the stable vinyl ether (II) can be converted into (I
This is presumed to be due to the coexistence of 1 mol % or more of vinyl ether (II'' which promotes the cyclization of II0) in the system.

In the vinyl ether monomer composition, the vinyl ether m is a hydroxyalkyl vinyl ether represented by the formula: (wherein, R1 is the same as above); dibasic acid anhydride, and ■ monofunctional basic compound which is an alkali metal compound or a compound containing a nitrogen atom or a phosphorus atom and whose pKa (acid dissociation index in water at 25°C) is 6 to 12. (Hereafter, when the two are not distinguished, they are simply referred to as base ■)
It can be obtained by reacting.

Specific examples of hydroxyalkyl vinyl ether, which is a raw material for this production method, include 4-hydroxybutyl vinyl ether, 2-hydroxyethyl vinyl ether, 3-hydroxy-〇-propyl vinyl ether, 2-hydroxy-1so-propyl vinyl ether, and 2-hydroxy-1so-propyl vinyl ether.
2-methylethyl vinyl ether, 2-hydroxy-1
, 1-dimethylethyl vinyl ether, 4-hydroxycyclohexyl vinyl ether, 3-hydroxycyclohexyl vinyl ether, 2-hydroxycyclohexyl vinyl ether, 4-hydroxybenzooxyvinyl and the like.

R2 contained in the tribasic acid anhydride and vinyl ether (II1 or (It)) is represented by the formula (II): % formula % () c In the formula, XI is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. , x2 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, p and q are 0 or an integer from 1 to 11 (however, they are never 0 at the same time), a group represented by the formula (i) −+CIh←−÷CX3=CII←−(ii
)S c In the formula, r is 0 or an integer of 1 to 3, S is an integer of 1 to 3, and x3 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms], a group represented by the formula (): [In the formula, R7 is -(CIIX' i group (Tata L, X4
is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, t is an integer of 1 to 4), H3 formula (f): [wherein, R8 is a ←CII atom or alkyl group having 1 to 3 carbon atoms, U is 3
) or +CX6-CX7→- group (where XI and XI are the same or different and are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and ■ is an integer of 2 to 3)] A group represented by the formula (V) nee C(-C1l 2) -C)+2
- A group represented by (v) or a group represented by the formula (0: can be mentioned.

Specific examples of tribasic acid anhydrides include maleic anhydride,
Succinic anhydride, methylconollic anhydride, phthalic anhydride,
Adipic anhydride, glutaric anhydride, glutaconic anhydride,
Itaconic anhydride, 1,8-naphthalic anhydride, citraconic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 4-methyl-1,2-hexanedicarboxylic anhydride, anhydride e
ls-4-cyclohexene-1,2-dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic anhydride, Diels-Alder of cyclopentadiene and maleic anhydride
Examples include adducts resulting from reactions.

Generally, the reaction between a hydroxyl compound and a tribasic acid anhydride proceeds according to the following formula in the presence of a basic catalyst.

In this case, it is sufficient to use at most 0.5 mol % (based on the dibasic acid anhydride) of the base to obtain the desired product with a yield of 90% or more. However, according to research conducted by the present inventors, when hydroxyvinyl ether, which is highly cationically reactive, is used as a hydroxyl compound, the reaction cannot be converted to the desired product in the absence of a base, as will be described later.
Moreover, if it is about 0.5 mol %, the yield of the target product is low and the stability is poor, so it is not suitable as a monomer for polymerization.

However, by making the base (1) present in an amount of 1 mol % or more, the yield exceeds 90%, and the resulting product is also stable, so that a decrease in the yield can be prevented. The reason is,
It is believed that the base (2) prevents the reaction between the carboxyl group and the vinyl group, and also prevents the cyclization of the vinyl ether (II) produced as described above. Note that the base (2) reacts stoichiometrically with the carboxyl group, but as mentioned above, it only needs to be present in the reaction system in an amount of 1 mol% or more based on the acid anhydride (2). The mixture can be changed.

In addition, the monomer composition is vinyl ether (II1) and (I
) to the mixture with vinyl ether (II).
It can also be obtained by reacting with The base (2) added later may be the same as or different from the base present during the reaction. In this case, the carboxyl group of the vinyl ether (II) and the base (2) react stoichiometrically.

As the base (2), as mentioned above, an alkali metal compound and a specific monofunctional basic compound are used.

The alkali metal compound is preferably a compound of Li, K or Na, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, sodium methylate, sodium ethylate, potassium methylate, etc. can be given.

The specific monofunctional basic compound is a compound containing a nitrogen atom or a phosphorus atom as described above, and its p
It is a basic compound having a Ka of 6 to 12, preferably 8 to 11. Those with pea in this range have high salt-forming ability,
Vinyl ether (I) has a large stabilizing effect. That is, those having a pKa higher than the carboxylic acid of the dibasic acid anhydride (1) have a high salt-forming ability, and those having a pKa 3 to 8 higher than the corresponding carboxylic acid are particularly preferred.

Suitable monofunctional basic compounds include ammonia, amines, phosphines, and the like. Specific examples of amines include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, 5ea-butylamine, 1°2-dimethylpropylamine, 2-ethylhexylamine, tridecylamine, Dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, dibutylamine, di-isobutylamine, di-5ee-butylamine, di-2-ethylhexylamine,
Trimethylamine, triethylamine, trilopropylamine, tri-butylamine, N-methylbutylamine, N-ethylbutylamine, N,N-dimethylethylamine, N,N-dimethylisopropylamine,
N,N-dimethyltetradecylamine, N,N-dimethyloctadecylamine, 2-methoxyethylamine, 3
-ethoxyethylamine, cyclohexylamine, N,
N-dimethylcyclohexylamine, dicyclohexylamine, benzylamine, N,N-dimethylbenzylamine, 4-methoxyphenylethylamine, ethanolamine, jetanolamine, triethanolamine,
Isobrobanolamine, dimethylethanolamine,
Pyrrolidine, piperidine, ■-methylpiperidine, 4-
Examples include methylpiperidine and morpholine.

Specific examples of phosphines include trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, trilaurylphosphine, tristearylphosphine, dimethylphosphine, diethylphosphine, and dibutylphosphine. Di- or trialkylphosphines such as phosphine, dioctylphosphine, dilaurylphosphine; tris(3-hydroxypropyl)phosphine, tris(2-cyanoethyl)
Phosphine, tris(2-methoxyethyl)phosphine, tris(2-chloroethyl)phosphine, tris(2-methoxycarbonyl)phosphine, tris(
2-(2-dimethylaminoethoxy)carbonyl)phosphine, tris(2-ethoxycarbonyl)phosphine, bis(3-hydroxypropyl)phosphine,
Di- or tri-g1-substituted alkylphosphines such as bis(2-cyanoethyl)phosphine; alicyclic phosphines such as dicyclopentylphosphine, dicyclohexylphosphine, tricyclopentylphosphine, and tricyclohexylphosphine; nitriphenyl Phosphine, tris(4-methylphenyl)
Di- or triarylphosphines such as phosphine, diphenylphosphine, bis(4-methylphenyl)phosphine; tribenzylphosphine;
Di- or tri-aralkylphosphines such as triphenethylphosphine, dibenzylphosphine, and diethylphosphine; Phosphines containing a phosphorus atom in the ring such as tetramethylenephosphine and tetramethylene-methylphosphine; diphenylmethylphosphine , diphenylethylphosphine, and phenyldiethylphosphine, in which two or three different organic groups are bonded to a phosphorus atom. Tertiary amines are particularly preferred.

The reaction temperature is usually -80 to 100°C, preferably 0 to 5°C.
It is 0°C. A solvent is usually used, but the process can be carried out without using it. Solvents can be used except for alcohols that react with tribasic acid anhydrides, but ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone may cause a decrease in the reactivity of the raw materials and coloration of the reaction mixture. It is preferable because there is no. The amount of base ■ to be used is as described above.
tribasic acid anhydride, usually 0.01 to 1.2,
Preferably it is 0.05 to 1.0 (however, molar ratio).

Other carboxyl group-containing olefins as component (B) include monomers represented by formula (IN). Specific examples include dicarboxylic acid monoallyl ester and dicarboxylic acid monomethallyl ester synthesized from allyl alcohol or methalyl alcohol and the tribasic acid anhydride.

The production method of the present invention uses a ketone solvent and an alcohol solvent represented by the formula N as polymerization solvents when copolymerizing a hydroxy group-containing olefin prisoner, a carboxyl group-containing olefin (B), and a fluoroolefin (C). It is characterized by the use of a mixed solvent of

Examples of ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone,
Examples include acetylacetone, cyclohexanone, etc.
Acetone or methyl ethyl ketone, especially acetone, is preferred.

Examples of the alcoholic solvent represented by the formula N include one or more of methanol, ethanol, isopropanol, n-butanol, t-butanol, methyl cellosolve, butyl cellosolve, butyl calpitol, and methyl calpitol. methanol, ethanol, impropatol or n-butanol are preferred.

As mentioned above, if a ketone solvent is used alone for polymerization, gelation occurs, but if a ketone solvent and the alcohol solvent are used in combination, gelation does not occur. The reason for this is presumed to be that gelation caused by crosslinking between the hydroxy group-containing olefin holes and the ketone solvent is prevented by adding the alcohol solvent. However, alcohol-based solvents have the disadvantages mentioned above, so in order to suppress gelation and avoid the disadvantages of alcohol-based solvents,
Alcohol solvent/hydroxy group-containing olefin (molar ratio) is 1/10 to 10/10, preferably 1.73 to 5/
Use within the range of l.

The amount of mixed solvent is usually 4/1-1 for all seven solvents.
/4 is preferred.

When such a mixed solvent is used as a polymerization solvent, it does not have an adverse effect on each monomer, has an excellent polymerization yield, contains low molecular weight substances in the resulting polymer solution, and has excellent paintability and physical properties of the coating film.

The copolymerization system basically consists of olefin holes containing hydroxy groups,
It consists of a carboxyl group-containing olefin (B), a fluoroolefin (C), a polymerization solvent, and a polymerization initiator. As the polymerization method, emulsion polymerization, suspension polymerization, solution polymerization, etc. can be adopted.

The polymerization temperature can be changed as appropriate depending on the type of initiator and solvent, but is usually -20 to 150°C, preferably 5°C.
~95°C. The reaction pressure can also be selected as appropriate, but is usually 0 to 50 kg/cj G.

Examples of the fluoroolefins (C) include tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, vinylidene fluoride, and vinyl fluoride.

In the present invention, the reaction molar ratio between the hydroxy group-containing olefin hole, the carboxyl group-containing olefin (B), and the fluoroolefin (C) is usually (A)/[8)/(C).
-t~50/1~H/20~80.

When a fluorine-containing copolymer is used as a water-soluble paint, it contains 5 to 50 mol% of hydroxy group-containing olefin holes,
Furthermore, in order to improve the water solubility of this copolymer, it is preferable to contain 5 to 60 mol% of carboxyl group-containing olefin [8], in which the carboxyl group is 3 (
It is more preferable that it is neutralized by II% or more (in the case of electrodeposition coating). Compounds used for neutralization include those exemplified in the above-mentioned base ①.

When a fluorine-containing copolymer is dissolved in an organic solvent and used as a so-called solvent-based paint, the hydroxyl group-containing olefin pores are 2 to 40 mol%, and the carboxyl group-containing olefin (Bl content is the same as that of the base material). It is preferably 1 to 15 mol% from the viewpoint of adhesion, and preferably 2 to 10 mol% from the viewpoint of pigment dispersibility.

The fluorine-containing copolymer may contain, in addition to the components (C), other ethylenically unsaturated compounds in an amount of 80 mol % or less relative to the fluorine-containing copolymer. Other types of ethylenically unsaturated compounds include, for example, the formula: %Formula %) (wherein R3 is an aliphatic group having 1 to 17 carbon atoms, an alicyclic group having 3 to 17 carbon atoms, or an alicyclic group having 3 to 17 carbon atoms. Examples include alkyl vinyl ethers or vinyl esters represented by 1 to 20 fluoroalkyl groups (k represents 0 or 1), and specific examples include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n- Butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, lopentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, lauryl vinyl ether, stearyl vinyl ether, 2,2.2-trifluoroethyl vinyl ether, 2
, 2,3.3-tetrafluoropropyl vinyl ether, 2,2,3,3.3-pentafluoropropyl vinyl ether, 2,2,3,3°4.4,5.5-octafluoropentyl vinyl ether, 2, 2, 3, 3, 4,
4.4-Heptafluorobutyl vinyl ether, vinyl acetate, vinyl brobionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl laurate, vinyl versatate, vinyl cyclohexanecarboxylate, etc. It will be done.

Furthermore, the formula: %Formula% (wherein, Number 3
~17 alicyclic groups or fluoroalkyl groups having 1 to 20 carbon atoms, the bias is 0 or 1), and specific examples include ethylene, propylene, ■-butene, isobutyne, Styrene, vinyl chloride, vinylidene chloride, isobutyl acrylate, methyl acrylate, ethyl methacrylate, 2゜2.3,3.3-
Pentafluoropropyl α-fluoroacrylate, 2
, 2,3,3,4,4,5,5,6,8.7.7-dozocafluoropentyl α-trifluoromethyl acrylate, cyclohexyl acrylate, 2゜2.3,3,
4, 4, 5.5, 6, 8, 7.7, 8.8, 9, 9, 1
0,10.11,11°+2.12.13.13,14
．． Examples include 14,15,15.15-nonacosafluoropentadecyl acrylate, octyl α-chloroacrylate, and octadecyl acrylate.

Compounds represented by the formula: % (in the formula % represents a chlorine atom or an aliphatic oxy group having 1 to 8 carbon atoms) can also be used, and specific examples include allyl chloride, allyl methyl ether, Examples include allyl isopropyl ether and allyl octyl ether.

Also, if necessary, a small amount of polyvalent metal (for example, M
g, Ca5Zn, AN, etc.) or polyfunctional nitrogen or phosphorus atom-containing compounds (e.g. polyamines such as alkyldiamines and alkyltriamines, polyphosphines such as alkylsiphosphines and alkyltriphosphines) and vinyl ethers. Divinyl ether, trivinyl ether, etc. consisting of a salt with (II) can also be present as a copolymerization component, and in this case, it can be used for purposes such as matting due to partial gelation.

Examples of polymerization initiators include persulfates (ammonium persulfate, potassium persulfate, etc.), persulfates and sulfites (
Redox initiators consisting of potassium sulfite, sodium sulfite, etc.) or acidic sulfites (acidic potassium sulfite, acidic sodium sulfite, etc.), organic peroxides (diisopropyl peroxydicarbonate, tert-butyl peroxybutyrate, benzoyl sulfite, etc.) oxide, isobutyryl peroxide, etc.), and azo compounds (azobisisobutyronitrile, etc.). The amount of the initiator used is usually 0.05 to 5% by weight, preferably 0.05 to 2.0% by weight, based on the total monomers used.

There are no particular limitations on the operating method of the production method of the present invention, and methods such as batch, semi-continuous, and continuous methods can be employed.

Next, the present invention will be explained based on Examples, but the present invention is not limited to these Examples.

Reference Example 1 A solution consisting of 405 g (2.83 mol) of 1,2-cyclohexanedicarboxylic anhydride (acid anhydride) and 40 g of acetone was placed in a 10-mouth Om+ flask, and triethylamine (base: pKa=lO, 72) 2 .63g
(0.26 mol) was added and stirred for 5 minutes with a magnetic stirrer.

While cooling this mixture with ice water to a temperature of 0 to 10°C, 305 g (2
, 83 mol) was added dropwise at a rate of 2 g/min.

The reaction mixture was subjected to Fourier transform nuclear magnetic resonance analysis (FT
-NMR% + 3C% tetramethylsilane standard $) was carried out, and the following vinyl ether fl) of the present invention (hereinafter referred to as cH
HEM salt) and the corresponding free vinyl ether (N
) (hereinafter referred to as c II II E M) is approximately I
It was confirmed that the product was produced at a yield of O/115 (molar ratio). The chemical shift of each carbon atom (signed from 8 to m) is shown.

vinegar.

Furthermore, the decomposition rate (%) of the obtained reaction product when stored at 20°C and -20°C was determined as 13C-7JMl? Investigated by. The results are also listed in Table 1.

[Margin below]

δ(ppl)-115,6<a+, 151.5<
In, 67.2(C), 25, 3-25, 6 (
d+, 62.1! (el, 173.3<r+, 42
．． 9((l+, 27 , 4<+11.24.4<i+,
43.5rj), 17G, 2ck+, 44.9 width, 9
, l (ffl) Reference Example 2 c tl II E in the same manner as in Reference Example 1 except that the amount of triethylamine in Reference Example 1 was changed to the amount shown in Table 1.
A monomer composition consisting of M salt and c I (If E M) was produced. The yield analyzed by FT-NMI? is shown in Table 1. Reference Example 3 Obtained under the conditions of Experiment No. 4 of Reference Example 2. Reaction product (c
H) IBM salt/dllEM-0,1/84.9:
molar ratio) and the base shown in Table 2 to make cllHEM.
11 tl EM salt, and the decomposition rate was examined in the same manner as in Reference Example 2. The results are shown in Table 2.

[Margin below]

The temperature was maintained at 65°C. After the preparation was completed, the reaction was continued at 65° C. for 16 hours to obtain a carboxyl group-containing tooth rigging device. The yield was 455 g, and the copolymer concentration was 64%.

Examples 2 to 5 and Comparative Examples 1 to 4 J polymerization was carried out in the same manner as in Example 1 using the compositions shown in Table 3 to obtain fluorine-containing copolymers. Their yields and copolymer concentrations are shown in No. 35.

[Margin below]

As is clear from Table 2, basic compounds with pKa less than 6 have weak basicity, so cH! It can be seen that the contribution of IEH to stabilization is small.

Example 1 140.2 g of acetone and 19.8 g of ethanol in a glass autoclave with a volume of 800 ml equipped with a stirrer
was charged, solidified with liquid nitrogen, and then degassed.

After that, chlorotrifluoroethylene (hereinafter referred to as CTFE)
), and the system was heated to 65°C. Next, a vinyl ether monomer composition separately obtained in Reference Example 1 (cHtlEM salt/cllHEM-10/8
5. molar ratio) 72.83g, hydroxybutyl vinyl ether (hereinafter referred to as II B V B) 49.9 g
, a vinyl ester of a carboxylic acid having an alkyl group having IO carbon atoms [Beoba 10 manufactured by Shell Chemical Co., Ltd. (hereinafter referred to as
(hereinafter referred to as VA) and 1.64 g of azobisisobutyronitrile (hereinafter referred to as AIBN) were mixed, and the monomer mixture was degassed after solidifying with liquid nitrogen.
I spent a lot of time preparing it continuously. As for the system temperature, the symbols in Table 3 represent the following compounds in parts by weight of water.

EVE: Ethyl vinyl ether AIBN: Azobisisobutyronitrile Example 6 The fluorine-containing polymer obtained in Example 1 was diluted with isopropyl alcohol (IPA) to a polymer concentration of 25% by weight. 100 g of the obtained varnish was placed in a flask equipped with a stirrer, MgOIO and Og were added thereto, and the mixture was stirred at 60° C. for 24 hours, and then filtered through a glass filter for dehalogenation treatment.

The 25% by weight varnish that had been dehalogenated was concentrated under reduced pressure to obtain a 65% concentration varnish. 3.9 parts by weight of dimethylethanolamine (0.9 equivalent to the acid value of the polymer) was added to 100 parts by weight of this varnish for neutralization.

Using the obtained partially neutralized varnish, an electrodeposition coating composition was prepared according to the following formulation.

Varnish 100 Butyl cellosolve 1080% methyl methylolated melamine resin (Melan 620° manufactured by Hitachi Chemical ■, solid content 70% by weight) 20 Deionized water 990 60B3S aluminum alloy plate anodized using this electrodeposition coating composition (Thickness of alumite film 9J7111)
was used as the object to be painted (anode), and the coating composition part was energized for 3 minutes at 20°C and a voltage of 140V, and the composition was deposited on the aluminum alloy plate, washed with water, and then kept at 180°C for 30 minutes and baked. It was cured to give an electrodeposited coating.

The properties shown in Table 4 of the resulting coating film were investigated. The results are shown in Table 4.

(Film thickness) It was measured using a film thickness meter (■Permascope EV model manufactured by Kerato Science Institute) (unit 2I).

(Gloss) Using a gloss meter (VC-2PD manufactured by Nippon Heavy Industries, Ltd.)
The 0° mirror reflectance (unit: %) was measured.

(Weather resistance) Weather meter (manufactured by Suga Test Instruments, Ducycle,
60 minutes of irradiation/60 minutes of darkness, black panel temperature 63℃)
A 360-hour accelerated weathering test was conducted to determine the gloss retention rate (
(Unit: 2%) was measured.

(Adhesion) 100 1-square folds were made in the coating film using a cutter knife, and a peel test was performed 10 times using cellophane adhesive tape to determine the number of remaining folds.

(iJ boiling water) Became a monk at JI8118802.

(Alkali resistance after water conduction resistance test) After the boiling water resistance test, the sample was immersed in a 1% by weight sodium hydroxide aqueous solution for 72 hours, and the appearance of the coating film was visually observed to check for any blistering. .

(Acid resistance) After immersion in a 5% hydrochloric acid solution for 7 days, changes in the coating film were visually determined.

(exterior) The appearance of the coating film was visually judged.

(Liquid Stability) The sample was left standing in an atmosphere at 30° C. for one month, and the change was visually judged.

Examples 7 to IO and Comparative Examples 5 to 8 Electrodeposition coating compositions were prepared in the same manner as in Example 6, except that the fluorine-containing polymers produced in Examples 2 to 5 and Comparative Examples 1 to 4, respectively, were used. It was prepared and electrodeposited.

The results are shown in Table 4.

Margin below C] [Effects of the Invention] According to the present invention, by using a specific polymerization solvent, it is possible to increase the yield and provide a more homogeneous fluorine-containing copolymer. When such a fluorine-containing copolymer is used as a coating material, a coating film that is free from flaking and repelling and has excellent weather resistance can be obtained.

Claims (1)

[Scope of Claims] 1 (A) a hydroxy group-containing olefin; (B) formula (I): CH_2=CHOR^1OC(=O)R^2C(=O)
O(H)nM(I) (in the formula, R^1 is a divalent aliphatic group having 2 to 10 carbon atoms, R^2 is a divalent organic group, M is an alkali metal, a nitrogen atom, or a phosphorus atom) A monofunctional basic compound which is a compound containing atoms and whose pKa is 6 to 12, n is 0 only in the case of an alkali metal, and 1 in other cases); and a vinyl ether represented by the formula (II). :CH_2=
CHOR^1OC(=O)R^2C(=O)OH(II)
(wherein R^1 and R^2 are the same as above), and the vinyl ether represented by formula (I) contains 1 mol% or more of the vinyl ether represented by formula (II). Vinyl ether monomer composition, or formula (III): ▲Mathematical formula, chemical formula, table, etc.▼(III) (In the formula, Y^1, Y^2 and Y^3 are the same or different, and the number of halogen atoms or carbon atoms 1 to 6 alkyl groups,
When copolymerizing the monomer represented by (a is 0 or an integer of 1 to 6, and R^2 is the same as above) and (C) fluoroolefin, a ketone solvent having 3 to 20 carbon atoms and the formula (IV ): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(IV) (In the formula, Y^4 is an alkyl group having 1 to 8 carbon atoms, Y^
5 is a hydrogen atom or a methyl group, l is an integer of 0 or 1 to 20) is mixed with a hydroxy group-containing olefin in a molar ratio of 1/10 to 10/1. A method for producing a fluorine-containing copolymer, characterized in that it is used as a solvent. 2. The production method according to claim 1, wherein the ketone solvent is acetone or methyl ethyl ketone. 3. The production method according to claim 1, wherein the alcohol solvent is methanol, ethanol, isopropanol or n-butanol. 4 Vinyl ether represented by formula (I) is converted to formula (II)
The method according to claim 1, wherein the method contains 5 mol% or more of vinyl ether represented by: 5. The method according to claim 1, wherein the fluoroolefin is selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, vinylidene fluoride, and vinyl fluoride.