JPH04106111A - Production of fluorocopolymer - Google Patents

Abstract

PURPOSE:To obtain a fluorocopolymer useful for various uses by radical- copolymerizing a fluorovinyl monomer with a hydroxylated vinyl monomer and other copolymerizable monomers in a polymerization solvent partially consisting of a specified alcohol. CONSTITUTION:A process for producing a fluorocopolymer by copolymerizing a fluorovinyl monomer (e.g. tetrafluoro-ethylene) with a hydroxylated vinyl monomer (e.g. 3-hydroxy-propyl vinyl ether) and other copolymerizable monomers (e.g. ethyl vinyl ether), wherein said monomers are radical- polymerized in a polymerization solvent partially consisting of at least one 8C or lower alcohol. The obtained fluorocopolymer can be used for many uses such as coating materials, sealing materials and films.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a new and useful method for producing a fluorine-containing copolymer. More specifically, the present invention comprises using specific alcohols as part of the polymerization solvent.
Related to an improved method for producing a fluorine-containing copolymer from a fluorine-containing vinyl monomer (a) and another monomer (c) copolymerizable with a hydroxyl group-containing vinyl monomer (b) .

The fluorine-containing copolymer thus obtained by the method of the present invention can be used for various purposes such as, among others, for paints, sealants, and films.

[Conventional technology]

In recent years, fluorine-containing copolymers containing hydroxyl groups have been developed as solvent-soluble crosslinked fluororesins with excellent weather resistance, and are mainly used for paints.

However, in the production of such fluorine-containing copolymers containing hydroxyl groups, especially when acid group-containing monomers are used and the reaction temperature is set to 70°C or higher in order to adjust the molecular weight, this There has been a problem in that the hydroxyl groups are lost due to side reactions, making it impossible to obtain the desired hydroxyl value-containing fluorine-containing copolymer.

[Problem to be solved by the invention]

Therefore, the inventors of the present invention earnestly embarked on research in order to solve the above-mentioned problems.

That is, the problem to be solved by the present invention is that fluorine-containing vinyl monomers (a) and hydroxyl group-containing vinyl monomers (b
) and other copolymerizable monomers (c), preventing loss of hydroxyl groups as much as possible during the copolymerization,
The object of the present invention is to provide an extremely effective method for obtaining a fluorine-containing copolymer having a desired hydroxyl value.

In order to solve this problem, the inventors of the present invention have made intensive studies and found that one or more specific alcohols having 8 or less carbon atoms are used as part of the polymerization solvent. By copolymerizing the monomers using
It was discovered that a desired fluorine-containing copolymer can be obtained without loss of hydroxyl groups during production, and the present invention was completed.

[Means for solving the invention]

That is, the present invention provides fluorine-containing vinyl polymers (a)
In the method for producing a fluorine-containing copolymer obtained by copolymerizing hydroxyl group-containing vinyl monomers (b) and other copolymerizable monomers (c), loss of hydroxyl groups during the reaction is In order to prevent this, the present invention aims to provide a new and useful method for producing fluorine-containing copolymers, which comprises using specific alcohols as part of the polymerization solvent.

The configuration of the present invention will be explained in detail below.

Here, first, as the above-mentioned fluorinated vinyl monomers (a), vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, fluorotrifluoroethylene , pentafluoropropylene, hexafluoropropylene, trifluoromethyl trifluorovinyl ether, pentafluoroethyl trifluorovinyl ether, or perfluoroalkyl/<fluorovinyl ether such as heptafluoropropyl trifluorovinyl ether. It is particularly desirable to use tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene or hexafluoropropylene.

These fluorine-containing vinyl monomers (a) may be used alone or in combination of two or more.

The usage ratio of the fluorine-containing vinyl monomers (a) is 15 to 70% by weight, preferably 30% by weight, based on the total amount of monomers.
The content is controlled to be 60% by weight. The monomers (
If the ratio of a) is less than 15% by weight, it is difficult to obtain sufficient weather resistance, while if it exceeds 70% by weight, the solvent solubility of the resulting fluorine-containing copolymer will decrease. The case is also unfavorable.

The aforementioned hydroxyl group-containing vinyl monomers (b) used for the purpose of imparting curability to the fluorine copolymer itself
If we limit ourselves to illustrating only the most representative examples,
2-Hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3
-Hydroxybutyl vinyl ether, 2-hydroxy-
Hydroxyl group-containing vinyl ethers such as 2-methylpropyl vinyl ether, 5-hydroxypentyl vinyl ether or 6-hydroxyethyl vinyl ether; addition reaction products of these doffed vinyl ethers and ε-caprolactone; 2-hydroxyethyl (meth)allyl ether , 3-hydroxyfurovir (meth)allyl ether, 2-hydroxypropyl (meth)allyl ether,
4-Hydroxybutyl (meth)allyl ether, 3-hydroxybutyl (meth)allyl ether, 2-hydroxy-2-methylpropyl (meth)allyl ether, 5-
Hydroxypentyl (meth)allyl ether or 6
- Hydroxyl group-containing allyl ethers such as hydroxyhexyl (meth)allyl ether; addition reaction products of these doffed various allyl ethers and ε-cafrolactone; 2-
Hydroxyethyl (meth)acrylate, 2-hydroquinfurovir (meth)acrylate, 3-hydroquinfurovir (meth)acrylate, 2-hydroquinfurovir (meth)acrylate! - Hydroxyl group-containing (meth)acrylates such as 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate or polypropylene glycol mono(meth)acrylate: or doffing thereof Examples include addition reaction main components of various (meth)acrylates and ε-caprolactone.

Examples of the other copolymerizable monomers (c) include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, and isofthyl. vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n
- alkyl vinyl ethers or substituted alkyl vinyl ethers such as hensyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl vinyl ether, chloromethyl vinyl ether, chloroethyl vinyl ether, hensyl vinyl ether or phenylethyl vinyl ether; /clopentyl vinyl ether, cyclohexyl vinyl ether, Cycroalkyl vinyl ether B such as methylcyclohexyl vinyl ether; vinyl acetate, vinyl propionate, vinyl isobutyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, C1 branched aliphatic vinyl carboxylate, CIO branched aliphatic vinyl carboxylates, branched aliphatic vinyl carboxylates such as C1l or vinyl stearate; vinyl cyclohexane carboxylates, vinyl cyclohexane carboxylates, vinyl benzoates or p-tert-butylbenzoic acid; Carboxylic acid vinyl esters with a cyclic structure such as vinyl; α-olefins such as ethylene, propylene or butene-1; Vinyl chloride or vinylidene chloride, excluding fluoroolefins; Various halogenated olefins: styrene, α- methylstyrene, p-te
Aromatic vinyl compounds such as rt-butylstyrene or vinyltoluene; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate-1, butyl methacrylate or cyclohequinyl methacrylate; or methyl acrylate, ethyl acrylate, These include acrylic esters such as butyl acrylate or cyclohexyl acrylate.

In addition to the above-mentioned copolymerizable monomer necks, monomers containing silyl groups, monomers containing amine groups, or monomers containing acid groups may be used as necessary. etc. are available.

Particularly representative examples of such monomers include vinyltrimethoxinelan, vinyltripropoxysilane, vinylmethylsheddysilane, vinyltrimethoxy(β-methoxy/ethoxy)silane, allyltrimethoxinelan, +-Rimethoxysilylethyl vinyl ether, triethoxyethylsilyl vinyl ether, methyldimethoxysilylethyl vinyl ether, trimethoxysilylbrobyl vinyl ether, 1-IJ ethoxylylpropylbyl vinyl ether, methylethoxy/silylpropyl vinyl ether, γ-(meth)acryloyloxy Propyltrimethoxysilane, γ-(meth)acryloyloxypropyltrimethoxysilane or γ
- Monomers containing a hydrolyzable silyl group such as (meth)acryloyloxyfuroylmethyldimethquinone; N-dimethylaminoethyl (meth)acrylamide,
N-diethylaminoethyl (meth)acrylamide, N-
Amino group-containing amide unsaturated monomers such as dimethylaminopropyl (meth)acrylamide or N-diethylaminepropyl (meth)acrylamide; dialkylaminoalkyl such as dimethylaminoethyl (meth)acrylate or ethylaminoethyl (meth)acrylate (Meth)acrylates; tert-butylaminoethyl (meth)acrylate, tert-butylaminopropyl (meth)acrylate, aziridinylethyl (meth)acrylate, bio-nodinylethyl (meth)acrylate or piperidinyl Ethyl (meth)
Amino group-containing monomers such as acrylates; or carboxyl group-containing monomers such as (meth)acrylic acid, crotonic acid, itafonic acid, monomethyl itaconate, monobutyl itaconate, maleic acid, monomethyl maleate, monobutyl maleate, or fumaric acid. There are monomers, etc.

Among such copolymerizable monomers, it is particularly desirable to use (substituted) alkyl vinyl ethers and/or cycloalkyl vinyl ethers from the viewpoint of increasing the polymerization yield.

To carry out copolymerization using each of the monomer components described above, bulk polymerization, solution (pressure), etc. are carried out in the presence of a radical polymerization initiator.
Known polymerization methods such as polymerization, suspension polymerization, or emulsion polymerization can be applied, or solution polymerization is most convenient.

The radical polymerization initiators used in this case include acetyl peroxide, henzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxidide, cyclohexanone peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, di-tert-butyl Peroxide, dicumyl peroxide, tert-butyl peroxybenzoate, 1ert-butyl peroxyoctoate, t
ert-butyl peroxyacetate or tert
- peroxides such as butyl peroxybivalate; or azo compounds such as azobisisobutyronitrile, dimethyl-2゜2゛-azobis(2-methylpropionate) or azobisisovaleronitrile, etc. It is listed as a typical example.

In addition, solvents used during such polymerization include aromatic hydrocarbons such as benzene, toluene, and xylene; n-
Aliphatic hydrocarbons such as pentane, n-hexanes, and n-octane; alicyclic hydrocarbons such as cyclobenkune, cyclohexanes, and ethylcyclohexane; mixed hydrocarbons such as mineral spirits; dimethoxyethane, tetrahydrofuran. , dioxane, diisopropyl ether,
Ethers such as di-n-butyl ether; methyl acetate, ethyl acetate, n-propyl acetate, 1sO-propyl acetate, n-butyl acetate, 1so-butyl acetate, amyl acetate, ethylene glycol monoethyl ether acetate,
Esters such as ethylene glycol monobutyl ether acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone, isophorone; chlorine such as chloroform, methylene chloride, carbon tetrachloride, tosochloroethane, tetrachloroethane and dimethylformamide, dimethylacetamide, N-methylpyrrolidone, ethylene carbonate, etc. are particularly representative.

Such polymerization solvents may be used alone or in combination of two or more.

On the other hand, in the present invention, examples of alcohols having 8 or less carbon atoms that can be used in combination with doffed polymerization solvents include methanol, ethanol, n-propatol, 1so-propatol, n-butanol, 1so-butanol, 5ec-butanol, tert-butanol, n-pentatol, n-hexanol, n-hepta7-
Alkyl alcohols such as alcohol, n-octatool, and 2-ethylhexanol; cycloalcohols such as cyclopentyl alcohol, cyclohexyl alcohol, and cyclooctyl alcohol; aromatic alcohols such as benzyl alcohol; ethylene glycol, ethylene glycol monomethyl Ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether,
Particularly representative examples include glycols such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether. These alcohols can be used alone or in combination of two or more.
Of course.

As mentioned above, these alcohols are used in combination with a polymerization solvent such as doffed, but the ratio of alcohol in the solvent is determined according to the proportion of the hydroxyl group-containing vinyl monomers (b) to be copolymerized. Depending on the amount, it is controlled to be within the range of 0.1 to 50% by weight, preferably within the range of 1 to 40% by weight.

If the amount of alcohol used is too small, a sufficient effect in preventing the loss of hydroxyl groups cannot be obtained, while if it is too large, a fluorine-containing copolymer with the target molecular weight distribution cannot be obtained. I can't.

If necessary, alcohol can be removed from the obtained fluorine-containing copolymer by a method such as vacuum distillation, or there is no problem in using it as it is.

The thus obtained fluorine-containing copolymer can be prepared by a known method.
Of course, the coating can be formed using a curing agent.

As such a curing agent, any known curing agent can be used, and specific examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, bovine silylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, and inholon. Diisocyanate, methylene bis-2,4-(or 2,6-
) diisocyanates, such as 4,4'-methylenebis(cyclohexyl isocyanate) or 1,3-di(incyanatomethyl)cyclohexane; triisocyanates such as 4-isocyanatomethyloctamethylene diisocyanate; ; polyisocyanate resins obtained by reacting the above diisocyanates with a polyhydroxy compound such as ethylene glyfur, phlopylene gellicol, neopentyl glyfur, trimethylolpropane or a hydroxyl group-containing polyester;
Polyisocyanate resins having billet bonds obtained by reacting the diisocyanates with water or polyisocyanate resins having incyanurate rings obtained by cyclopolymerizing the diisocyanates; methyl etherified methylolmelamine, n - Amino resins such as butyl etherified methylolmelamine and n-butyl etherified benzoguanamine; obtained by blocking the above polyisocyanates or polyisocyanate resins with a compound having active hydrogen such as alcohol, phenol, methyl ethyl ketoxime or ε-caprolactam. Blocked isocyanates; polyvalent metal alkoxides such as tetrabutoxyethane, tributoxyaluminum or tetrabutoxyzirconium; polyvalent metal cowrates obtained by reacting the polyvalent metal alkoxides with chelating agents such as acetylacetone or ethyl acetoacetate. compounds; or polycarphonic acid anhydrides such as trimellitic anhydride or biromelotic anhydride.

When such a curing agent is blended, the blending amount is 100% of the solid content of the fluorine-containing copolymer solution.
A suitable range is 1 to 100 parts by weight of the curing agent component to parts by weight.

The fluorine-containing copolymer thus obtained can be used as is, but if necessary, it may be added with colorants, various resins, solvents, fluidity regulators, color separation inhibitors, antioxidants, etc. Various known and commonly used additives such as UV absorbers, light stabilizers or silane coupling agents can be added without charge.

Examples of such colorants include dyes, organic pigments, inorganic pigments, and metal pigments, and examples of resins include acrylic resins and fluorine-containing vinyl resins obtained using monomers other than fluorine-containing vinyl monomers. , cellulose resins such as nitrocellulose or cellulose acetate butyrate, vinyl chloride/vinyl acetate copolymer resins, petroleum resins, ketone resins, oil-free alkyd resins, alkyd resins, and epoxy resins.

〔Example〕

Next, the present invention will be explained in detail with reference to Examples and Comparative Examples. In the following, all references to % mean % by weight unless otherwise specified.

Examples 1 to 4 In a 1 liter stainless steel autoclave that was sufficiently purged with nitrogen, monomers other than fluorine-containing vinyl monomers as shown in Table 1 were added as a solvent and a polymerization initiator. 2% of tert-butylperoquine piperaate and 0.5% of tert-butylperoquine-2-ethylhexanoate were charged based on the total amount of polymer.

Next, as a gelation inhibitor during polymerization, 1% of bis(1,2,2,6°6-bentamethyl-4-piperidinyl) separate was charged based on the total amount of monomers.

Thereafter, the liquefied and collected fluorine-containing vinyl monomer was injected and held at 75°C for 15 hours while stirring to carry out a polymerization reaction, and then the temperature was raised to 80°C and kept at the same temperature. The reaction was continued for 4 hours to obtain a solution of the desired fluorine-containing copolymer.

Thereafter, the alcohol used as a solvent was removed by vacuum distillation.

The table shows the hydroxyl value per non-volatile content and solid content of each copolymer solution after removing the solvent.

Comparative Examples 1 to 4 Reactions were carried out in the same manner as in Examples 1 to 4, except that the solvents shown in Table 1 were used, and control fluorine-containing copolymer solutions were obtained.

The hydroxyl value per non-volatile content and solid content for each of these copolymer solutions is shown in the same table.

/ As is clear from the comparative examples, when alcohols are not used in combination with the polymerization solvent, the hydroxyl value of the resulting F-7-wire polymer is significantly lower than the theoretical value, especially when the acid group-containing It can be seen that when vinyl monomers are copolymerized, there is a strong tendency to form a negative layer.

On the other hand, the examples show that even when an acid group-containing vinyl monomer is copolymerized, a fluorine-containing copolymer having a hydroxyl value almost exactly as the theoretical value can be obtained by using alcohols as a polymerization solvent. It is clear that this can be achieved.

〔Effect of the invention〕

Thus, a monomer mixture containing the fluorine-containing vinyl monomers (a), the hydroxyl group-containing vinyl monomers (b), and other copolymerizable monomers (c) as essential components is polymerized. According to the method of the present invention, in which the desired fluorine-containing copolymer is produced by radical polymerization using a specific alcohol as a part of the solvent, the fluorine-containing copolymer having the desired hydroxyl value can be stably produced. You can get a combination.

Therefore, according to the method of the present invention, a thin fluorine-containing copolymer that can be used in various applications such as paints, sealants, and films is provided.

Claims (1)

[Claims] 1. Fluorine-containing vinyl monomers (a), hydroxyl group-containing vinyl monomers (b), and other copolymerizable monomers (c)
In a method for producing a fluorine-containing copolymer by copolymerizing the monomers with the monomers, one or more alcohols having 8 or less carbon atoms are used as a part of the polymerization solvent, and the monomers are copolymerized with radical copolymer. A method for producing a fluorine-containing copolymer, comprising polymerization. 2. Production of the fluorine-containing copolymer according to claim 1, wherein the other copolymerizable monomers (c) use at least one acid group-containing vinyl monomer as an essential component. Method.