JPH0366713A - Production of fluorine-containing copolymer - Google Patents

Abstract

PURPOSE:To obtain a fluorine-containing copolymer excellent in weather resistance, etc., is good yield by using an alkyl-substituted benzene as a polymerization solvent in copolymerizing a fluorine-containing vinyl monomer with a monomer copolymerizable therewith. CONSTITUTION:A fluorine-containing vinyl monomer (e.g. vinyl fluoride), a monomer copolymerizable therewith (e.g. methyl vinyl ether) and preferably a hydroxyl group-containing vinyl ether (e.g. 2-hydroxyethyl vinyl ether) are copolymerized in the presence of a radical polymerization initiator (e.g. azobisisobutyronitrile) using one or more of >=8C alkyl-substituted benzenes (preferably o-xylene, etc.) as a polymerization solvent to afford a fluorine- containing vinyl copolymer, having stably regulated molecular weight and suitable as coatings, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel and useful method for producing a fluorine-containing copolymer. More specifically, the present invention relates to a method for producing an improved fluorine-containing copolymer of fluorine-containing vinyl monomers and other copolymerizable monomers using a specific polymerization solvent.

[Conventional technology]

Industrial-based xylene is a mixture of 0-xylene, m-xylene, p-xylene, and ethylbenzene, and the composition of the mixture varies from manufacturing loft to manufacturing loft and is not constant. be. When producing a fluoroolefin copolymer using such xylene as a polymerization solvent, there was a problem in that it was difficult to obtain a copolymer with the desired molecular weight due to variations in the xylene mixture composition. .

[Problem to be solved by the invention]

Therefore, based on the recognition of the current situation, a fundamental solution to the unresolved issues in the prior art, and the earnest needs of the industry, the present inventors have determined the molecular weight of this type of fluorine-containing copolymer. We have begun earnest research on how to reduce the variation in

Therefore, the problem to be solved by the present invention is to provide an extremely useful method for producing this type of fluorine-containing copolymer, which can adjust the molecular weight of the copolymer.

Therefore, the present inventors have conducted intensive research to solve the above-mentioned problems in the conventional technology, and have found that alkyl-substituted benzene consisting of a single component and having 8 or more carbon atoms is used as a polymerization solvent. , by radical polymerizing a monomer mixture containing fluorine-containing vinyl monomers and other monomers copolymerizable with these as essential components,
It has been discovered that a copolymer having the desired molecular weight can be obtained, and depending on the molecular weight of the desired copolymer,
By appropriately using alkyl-substituted benzene consisting of a single component and having a carbon number of 8 or more singly or in combination of two or more types as a polymerization solvent, the molecular weight of the resulting copolymer can be extremely stabilized. It was discovered that the adjustment can be made, and the present invention was completed.

[Means to solve the problem]

That is, the present invention provides a method for producing a fluorine-containing copolymer using fluorine-containing vinyl monomers and other monomers copolymerizable with these as essential components. A new and improved method for producing a useful fluorine-containing copolymer, which comprises radical polymerization using alkyl-substituted benzene having 8 or more carbon atoms alone or in a mixture of two or more types as a polymerization solvent. This is what we are trying to provide.

Hereinafter, the configuration of the present invention will be explained in detail.

The above-mentioned fluorine-containing vinyl monomer components used in the present invention include vinyl fluoride, hynylidene fluoride,
Trifluoroethylene, tetrafluoroethylene, fluorotrifluoroethylene, chlorotrifluoroethylene, pentafluoropropylene, hexafluoropropylene, or (bar)fluoroalkyl group having 1 to 1 carbon atoms
18 (bar)fluoroalkyl trifluorovinyl ether is a typical example.

Next, other monomers copolymerizable with the above-mentioned fluorine-containing vinyl monomers used in the present invention include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, Isobutyl vinyl ether%te
Alkyl vinyl ethers such as rt-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether or 2-ethylhexyl vinyl ether; cycloalkyl vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl vinyl ether or methyl cyclohexyl vinyl ether; benzyl vinyl ether or Aralkyl vinyl ethers such as phenethyl vinyl ether H2,2,3゜3-tetrafluoropropyl vinyl ether, 2゜2.3,3.4,4,5.5-octafluoropentyl vinyl ether, 2,2,3,3,4
, 4, 5, 5. 6. 6, 7, 7, 8, 8, 9.9 hexadecafluorononyl vinyl ether, perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorooctyl vinyl ether or perfluorooctyl vinyl ether. Fluorooctyl vinyl ether (bar) fluoroalkyl vinyl ethers: or vinyl acetate, vinyl propionate,
Vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl persate, vinyl laurate, vinyl stearate, vinyl benzoate, p-te
Typical examples include vinyl carboxylic esters such as vinyl rt-butylbenzoate, vinyl salicylate, and vinyl cyclohexanecarboxylate;
Typical examples include ethylene, vinyl chloride, vinylidene chloride, (meth)acrylonitrile, and various (meth)acrylic acid esters. Among these other copolymerizable monomers, it is desirable to use alkyl vinyl ethers and/or cycloalkyl vinyl ethers from the viewpoint of sufficiently increasing the polymerization rate. When using the copolymer as a base resin component for paint, from the viewpoint of coating hardness, vinyl esters of aliphatic monocarboxylic acids having branched alkyl groups having 4 to 17 carbon atoms, benzoic acid, etc. It is particularly desirable to use at least one monomer selected from the group consisting of vinyl, vinyl p-tert-butylbenzoate and vinyl cyclohexanecarboxylate.

Furthermore, as the above-mentioned hydroxyl group-containing vinyl ethers used for the purpose of imparting curability to the pedestal polymer itself, examples include 2-hydroxyethyl vinyl ether,
3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 2
-Hydroxy-2-methylpropyl vinyl ether, 5
Typical examples include -hydroxypentyl vinyl ether and 6-hydroxyethyl vinyl ether.

When producing a fluoroolefin copolymer from the above-mentioned monomer components by the method of the present invention, the ratio of each monomer component used is determined from the viewpoint of yield and weather resistance of the copolymer. 10 to 70 mol% of vinyl monomer 1, 10 to 90 mol% of other monomers copolymerizable with fluorine-containing vinyl monomers, and 0 to 40 mol% of hydroxyl group-containing vinyl ether, preferably, Within the range of 20 to 60 mol% of fluorine-containing vinyl monomers, 15 to 80 mol% of other monomers copolymerizable with fluorine-containing vinyl monomers, and 0 to 35 mol% of hydroxyl group-containing vinyl ether should be managed accordingly.

On the other hand, in the present invention, specific examples of alkyl-substituted benzenes containing 8 or more carbon atoms and containing 8 or more carbon atoms from the single component described above, which are used as polymerization solvents, include 0-xylene,
m-xylene, p-xylene, ethylbenzene, n-propylbenzene, cumene, pseudocumene, mesitylene, n-butylbenzene, 5eC-butylbenzene, te
Examples include various aromatic hydrocarbon solvents such as rt-butylbenzene, isobutylbenzene, 0-cymene, m-cymene, p-cymene, durene, isodurene, and amylbenzene, and these can be used alone or in combination of two or more types. Of course, it is also possible to use them together. Furthermore, it is also possible to use organic solvents other than the above-mentioned aromatic hydrocarbon solvents in combination with the aromatic hydrocarbon solvents. Typical examples of such organic solvents include aromatic hydrocarbons such as benzene or toluene; n-pentane, n-
aliphatic hydrocarbons such as hexane or n-octane; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane or ethylcyclohexane; methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, te
rt-butanol, n-pentanol, impentanol, n-hexanol, n-octanol, 2-ethylhexanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether or Alcohols such as propylene glycol monoethyl ether; ethers such as dimethoxyethane, tetrahydrofuran, dioxane, diisopropyl ether or di-n-butyl ether; such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone or isophorone. Ketones; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate or ethylene Esters such as glycol monobutyl ether acetate; or chlorinated hydrocarbons such as chloroform, methylene chloride, carbon tetrachloride, trichloroethane or tetrachloroethane; and
N-methylpyrrolidone, dimethylformamide, dimethylacetamide or ethylene carbonate. When such organic solvents are used in combination with the above-mentioned aromatic hydrocarbon solvents, the organic solvents may be used alone or in a mixture of two or more, but the resulting copolymer will not dissolve. It goes without saying that a suitable solvent may be selected and used. The appropriate amount of the solvent used as the polymerization solvent is about 5 to 1000 parts by weight based on 100 parts by weight of the total amount of monomers used. In carrying out the method for producing a fluoroolefin copolymer according to the method of the present invention, a known and commonly used radical polymerization initiator is used as a polymerization initiator.
Particularly representative of these are azo compounds such as azobisisobutyronitrile or abbisisovaleronitrile; -2-Ethylhexanoate, penzole peroxide, lauroyl peroxide, acetyl peroxide, di-tert-butyl peroxide, di-tert-butyl peroxide, tert.
Peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, methyl ethyl ketone peroxide or diisopropyl peroxycarbonate.

The amount of such a radical polymerization initiator to be used is appropriately determined depending on the type of polymerization initiator, polymerization temperature, molecular weight of the copolymer, etc., but is generally 0.00% of the total amount of monomers to be copolymerized.
Approximately 0.01 to 10% by weight is appropriate.

In order to produce a fluorine-containing polymer from each of the monomer components described above by a solution polymerization method, there is a method in which all the monomers, a solvent, and a polymerization initiator are charged at once and the polymerization is carried out;
■There is also a method in which polymerization is carried out by adding other monomers and a polymerization initiator continuously or in portions to a reactor containing a solvent and fluorine-containing vinyl monomers, or, ■There is a method in which polymerization is carried out by adding monomers and a polymerization initiator each continuously or in portions to a reactor containing only a solvent;
Furthermore, there is also a method in which polymerization is carried out by adding a solvent, a polymerization initiator, and other monomers continuously or in portions to a reactor containing fluorine-containing vinyl monomers. As mentioned above, various methods can be mentioned, but it goes without saying that any of these methods can be applied to the present invention.

When preparing the desired copolymer according to the method of the present invention,
The reaction temperature and reaction pressure may be selected as appropriate depending on the type of initiator used, the type of solvent used, the molecular weight of the desired copolymer, etc., but usually the reaction temperature is 0 to 140'. C1 preferably 40-100°C
The reaction pressure is usually within the range of LOO
kg/(jl! or less, preferably 40 kg/cd or less is appropriate.

In this way, the fluoroolefin copolymer obtained by the method of the present invention can be cured as is or with pigments, fillers, etc., which can react with the hydroxyl groups, if the fluorine-containing polymer has hydroxyl groups. It can be used in a variety of applications, including paints, sealants, and films, in combination with agents and curing catalysts.

〔Effect of the invention〕

Thus, a monomer mixture containing fluorine-containing vinyl monomers and other monomers copolymerizable with these as essential components can be used as a polymerization solvent, which is more powerful than a single component and has a carbon number of 8. By following the method of the present invention, in which the above-mentioned alkyl-substituted benzenes are used alone or in a mixture of two or more, and the desired fluorine-containing polymer is produced by radical polymerization, the molecular weight can be stably adjusted. The desired copolymer can be obtained.

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

〔Example〕

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

Examples 1 to 14 Monomers other than fluorine-containing vinyl monomers as shown in Tables 1 and 2 were placed in 12 stainless steel autoclaves that were sufficiently purged with nitrogen, and polymerization was initiated. and an organic solvent.

Next, among Examples 5 to 8 and Examples 11 to 14, 1% of bis( 1,2,2,6,6-pentamethyl-4-pyridinyl) sebacate was also charged.

After that, the liquefied and collected fluorine-containing vinyl monomers were injected and kept at 60°C for 15 hours while stirring to continue the polymerization reaction, and then the temperature was raised to 80°C and the same temperature was maintained. The reaction was continued for 4 hours to obtain a solution of the desired fluorine-containing polymer.

The nonvolatile content, number average molecular weight, and weight average molecular weight of each copolymer solution are summarized in the same table.

Examples 15 to 2 In addition, the same reactions as in Examples 1 to 14 were carried out twice to obtain a solution of the desired copolymer. The number average molecular weights and weight average molecular weights of the various fluorine-containing polymers obtained are listed in Tables 1 and 2.

Examples 29-42 Furthermore, the same reactions as in Examples 1-14 were carried out three times,
A solution of the desired copolymer was obtained. The number average and weight average molecular weight of each fluorine-containing rope polymer are shown in Table 1 and Table 2.
It is also listed in the table.

Comparative Examples 1 to 6 Comparative Examples 4 to 6
Bis(1,2,2,6,
The reaction was also carried out using 6-pentamethyl-4-piperidinyl) sebacate to obtain a control solution of fluorine-containing polymer. The various property values for the solutions of these copolymers are summarized in the same table.

/ / / / 84- From Table 3, industrial xylene with three composition ratios (
It is known that the molecular weight values of the control table hook polymer obtained by polymerization reaction in a system using industrial base xylene as the polymerization solvent vary widely depending on the type of xylene, and on the other hand, First, from Table 1, the molecular weight of the fluorine-containing polymer when each of 0-xylene, m-xylene, p-xylene, or ethylbenzene, which are components of industrial base xylene, is used alone as a polymerization solvent, In other words, it can be seen that the "dispersion" in the molecular weight values of the products obtained by a total of three polymerization reactions is significantly reduced, and from Table 2, alkyl-substituted benzenes having 8 or more carbon atoms The molecular weight values of the fluorine-containing polymers obtained by a total of three polymerization reactions in a system using a mixed solvent with a fixed ratio of ” has become significantly smaller.

Procedural amendment flat bottom 1 year

Claims (1)

[Scope of Claims] 1. A fluorine-containing copolymer is obtained by copolymerizing a monomer mixture containing a fluorine-containing vinyl monomer and other monomers copolymerizable therewith as essential components. In the manufacturing method, one or two alkyl-substituted benzenes having 8 or more carbon atoms
A method for producing a fluorine-containing copolymer, characterized in that the monomers are radically copolymerized using at least one of the above monomers as an essential polymerization solvent. 2. In a method for producing a fluorine-containing copolymer by copolymerizing a fluorine-containing vinyl monomer, a hydroxyl group-containing vinyl ether, and another monomer copolymerizable with the fluorine-containing vinyl monomer. A method for producing a fluorine-containing copolymer, which comprises radical copolymerizing the monomers using one or more alkyl-substituted benzenes having 8 or more carbon atoms as a polymerization solvent. 3. The alkyl-substituted benzene having 8 or more carbon atoms is at least one compound selected from the group consisting of o-xylene, m-xylene, p-xylene and ethylbenzene, according to claim 1 or 2. Production method.