JPH01158064A - Fluorine-containing polymer composition - Google Patents

Abstract

PURPOSE:To obtain the title composition providing a crosslinked fluorine- containing polymer having excellent elongation, tensile strength, compression set, etc., by compounding a specific fluorine-containing copolymer with a specific amount of an organic peroxide. CONSTITUTION:The objective composition is produced by compounding (A) a fluorine-containing copolymer produced by copolymerizing (A1) 3- bromoperfluoropropyl perfluorovinyl ether or 2-bromoperfluoropropyl perfluorovinyl ether and (A2) a 2-8C fluorine-containing monomer copolymerizable with the component A1 (e.g., tetrafluoroethylene) at a ratio to get a copolymer containing 0.01-5mol% of perfluoropropyl vinyl ether with (B) 0.1-10wt.% of an organic peroxide [e.g., 2,5-dimethyl-2,5-bis(tert- butylperoxy)-hexane].

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a fluoropolymer composition that is curable with an organic peroxide and contains a fluoropolymer.

Technical background of the invention and its problems Compared to ordinary rubber compositions, fluororubber has excellent heat resistance,
It has excellent solvent resistance or chemical resistance, and this property is used in, for example, hoses, tubes, sealing materials, etc. Such fluororubbers are often obtained by vulcanizing and curing a fluoropolymer with an organic peroxide.

By the way, as a fluorine-containing polymer that can be cured by vulcanization with an organic peroxide, a Br (bromine)-containing polymer is copolymerized with a fluorine-containing monomer in the shell to introduce Br atoms into the main chain. This fluorine-containing polymer is usually formed into a three-dimensional crosslinked structure by radically removing and adding Br atoms introduced into the main chain.

For example, in Japanese Patent Publication No. 54-1585, (1) 3%
A fluorine-containing polymer obtained by copolymerizing the following bromine-containing olefins and (2) a fluorine-containing hexamer having 2 to 7 carbon atoms, and containing at least 0.05% by weight of bromine in the copolymer. is disclosed. In addition, special public service 53-41
No. 15 discloses (1) 3 mol% or less of 4-bromo-3
, 3,4,4-tetrafluorobutene-1 or promotrifluoroethylene, and (2) tetrafluoroethylene and perfluoroalkyl perfluorovinyl ether containing an alkyl group of 01 to 5 are copolymerized, and at least A fluoropolymer containing 0.05% by weight of bromine in the copolymer is disclosed. Furthermore, Japanese Patent Application Laid-Open No. 60-195113, ROCX-CYZ (
A fluorine-containing polymer obtained by copolymerizing monomers represented by X, Y, and Z (one or two of D is bromine or iodine, and the rest are hydrogen, fluorine, or chlorine) is disclosed. .

However, the fluoropolymer disclosed in the above publication is
Since all bromine atoms that are active against organic peroxides are introduced into the main chain or extremely rigid side chain of the fluoropolymer, the crosslinked fluoropolymer has low compression set, elongation, There was a problem in that it was not possible to obtain satisfactory values in terms of physical properties such as tensile strength and 100% modulus.

Also, R
The monomer represented by OCX-CYZ has a problem in that its synthesis requires many steps and is time-consuming.

On the other hand, U.S. Patent No. 3.351.619 discloses a fluorine-containing polymer obtained by polymerizing a vinyl ether containing fluoroalkyl iodide;
No. 06.879 discloses a fluoropolymer obtained by copolymerizing 2-bromoethyl vinyl ether or 2-iodoethyl vinyl ether. However, fluorine-containing polymers containing iodine atoms have poor photostability, and hydrocarbon vinyl ethers such as bromoethyl vinyl ether, which do not contain fluorine atoms, have poor heat resistance and copolymerizability.

The present inventors conducted extensive research to solve the problems associated with the prior art as described above, and found that the bromine atom, which is active against organic peroxides, is not in the main chain or extremely rigid side chain. When a fluoropolymer introduced into a flexible side chain is crosslinked with an organic peroxide, it elongates,
The present invention was completed based on the discovery that a material having extremely excellent physical properties such as tensile strength and compression set can be obtained.

Purpose of the Invention The present invention aims to solve the problems associated with the prior art as described above, and is aimed at improving physical properties such as elongation, tensile strength, and compression set when crosslinked with an organic peroxide. It is an object of the present invention to provide a fluoropolymer composition crosslinkable with an organic peroxide containing a fluoropolymer, which can provide a crosslinked fluoropolymer with extremely excellent properties.

Summary of the Invention The fluoropolymer composition according to the present invention comprises [A](1)3
- Bromoperfluoropropyl perfluorovinyl ether or 2-bromoperfluoropropyl perfluorovinyl ether, and (2) 2 to 2 carbon atoms copolymerizable with the above perfluoropropyl perfluorovinyl ether.
8 and the above perfluoropropyl perfluorovinyl ether in a copolymer containing 0.01~
A fluorine-containing copolymer obtained by copolymerization so that it is present in an amount of 5 mol%, and [B] 0.1 to 10% by weight with respect to the above copolymer [A]
It is characterized by consisting of an organic peroxide.

From the fluoropolymer composition according to the present invention, a crosslinked fluoropolymer having extremely excellent physical properties such as elongation, tensile strength, and compression set can be obtained. In addition, since the fluoropolymer contained in the fluoropolymer composition according to the present invention uses monomers with good copolymerizability during its manufacture, it is possible to improve the efficiency and simplify the manufacturing process. can.

DETAILED DESCRIPTION OF THE INVENTION A fluoropolymer composition containing a fluoropolymer according to the present invention will be described below.

The fluoropolymer composition according to the present invention includes [A] a fluoropolymer and [B] an organic peroxide, and first, the fluoropolymer [A] will be explained.

The fluoropolymer used in the present invention is copolymerizable with (1) 3-bromoperfluoropropyl perfluorovinyl ether or 2-bromoperfluoropropyl perfluorovinyl ether and (2) this perfluoropropyl perfluorovinyl ether. A fluorine-containing monomer having 2 to 8 carbon atoms is added in an amount of 0.01 to 5 mol % in a copolymer from which a unit derived from 3-bromoperfluoropropyl perfluorovinyl ether or 2-bromoperfluoropropyl perfluorovinyl ether is obtained. It is obtained by copolymerization in such a manner that it is present in a certain amount.

In the present invention, it is preferable to use 8-bromoperfluoropropyl perfluorovinylether as the vinyl ether because the resulting fluoropolymer has various properties such as excellent elongation, tensile strength, and compression set.

Examples of fluorine-containing monomers having 2 to 8 carbon atoms that can be copolymerized with the above-mentioned bromine-containing perfluoropropyl perfluorovinylether include tetrafluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, hexafluoropropene, pentafluoropropene, and perfluoropropene. Fluoroalkyl perfluorovinyl ether (perfluoromethyl perfluorovinyl ether, perfluoroethyl perfluorovinyl ether, perfluoropropyl perfluorovinyl ether, etc.), trifluoroethylene,
Vinyl fluoride, hexafluoroisobutyne, etc. are used. Further, two or more of these fluorine-containing monomers may be used. When two or more types of fluorine-containing monomers are used in this way, the resulting fluorine-containing polymer can be ternary or quaternary.
It becomes a multidimensional system that is more than an elemental system.

Furthermore, as a fluorine-containing monomer having 2 to 8 carbon atoms copolymerizable with perfluoropropyl perfluorovinyl ether, a fluorine-containing diene monomer can also be used together with the above-mentioned 7-mer. A fluorine-containing polymer with excellent properties) can be obtained.

Examples of such fluorine-containing diene monomers include perfluoro-1,3-butadiene and non(-fluoro-1,4-
Pentadiene, 1.1.2-trifluoro-1,3-butadiene, 1,1.24-trifluoro-1,4-pentadiene, 1.1.2.3.3-pentafluoro-1,4-
Pentadiene, perfluoro-1,7-octadiene,
Tsuku-fluorodivinyl ether, perfluorovinyl perfluoroallyl ether, vinyl monofluoroallyl ether, perfluorovinyl allyl ether, and the like are used.

The amount of these fluorine-containing diene monomers used is desirably about 1 mol % or less based on the fluorine-containing monomers.

If the amount is more than this, gelation of the obtained fluorine-containing polymer becomes significant, and processability (flow characteristics) and elongation of the obtained fluorine-containing polymer are reduced, which is not preferable.

In the present invention, (1) vinyl nityl as described above, and (
2) A fluorine-containing polymer is obtained by copolymerizing this vinyl ether with a copolymerizable fluorine-containing monomer, but in some cases, a non-fluorine-containing olefinic monomer that can be copolymerized with each of the above monomers, such as ethylene, is used. , propylene, etc. can also be copolymerized.

In the fluoropolymer used in the present invention, the number of units derived from 3-bromoperfluoropropyl perfluorovinyl ether or 2-bromoperfluoropropyl perfluorovinyl ether is 0.01 to 5.
It is desirable that the amount is mol %, preferably 0.01 to 2.0 mol %.

If this unit is present in an amount exceeding 5 mol%, stability during polymerization and processability will deteriorate, and the final vulcanizate will have poor rubber elasticity (elongation) and heat resistance. This is not desirable because it causes the

The fluoropolymer used in the present invention comprises 3-bromoperfluoropropyl perfluorovinyl ether or 2-bromoperfluoropropyl perfluorovinyl ether and 2-carbon atoms copolymerizable with this vinyl ether in the presence of a radical generating source. It can be obtained by polymerizing the fluorine-containing monomers of 1 to 8 in the form of solution polymerization or emulsion polymerization by a conventionally known method.

The polymerization temperature is not particularly limited as long as the radical reaction proceeds and depolymerization of the resulting polymer does not occur, but usually -
It is in the range of 30-150'C. The polymerization pressure is not particularly limited, and a wide range of pressures may be employed depending on the desired polymerization rate and degree of polymerization, but it is usually in the range of 1 to 100 kg/c.

When the fluoropolymer used in the present invention is to be obtained by solution polymerization, for example, an organic peroxide, a fluorine-containing organic peroxide, an organic azo compound, a fluorine-containing organic azo compound, etc. are used as a polymerization initiator. , perfluoro(l,2
-dimethylcyclobutane), perfluoro(1,2-dichloroethane), perfluoro(1,2,2-trichloroethane), perfluorocyclohexane, perfluorotributylamine, α,ω-cybidroba-fluoropolymethylene, perfluoro(methoxy The polymerization reaction is carried out in a polymerization solvent with low chain transfer properties such as polyethoxyethane), perfluorocyclobutane, and tert-butanol.

In addition, when the fluoropolymer used in the present invention is to be obtained by emulsion polymerization, inorganic peroxides such as persulfates, hydrogen peroxide, perchlorates, tert- Water-soluble polymerization initiators such as organic peroxides such as butyl hydroperoxide and dicumyl peroxide are used. Further, the inorganic peroxide may be used as a redox system in combination with a reducing agent such as sulfite, hyposulfite, or ascorbic acid. In order to adjust the molecular weight of the obtained fluoropolymer, a chain transfer agent such as methanol, ethanol, isopentane, ethyl acetate, diethyl malonate, carbon tetrachloride, etc. can be used as necessary. In addition, emulsifiers such as fluorine-containing carboxylates or fluorine-containing sulfonates are used for the purpose of stably dispersing polymer particles in the polymerization solution, increasing polymer concentration, or preventing polymers from adhering to the polymerization tank. These emulsifiers do not necessarily have to be used if they have a moderate surfactant effect.

The fluoropolymer described above can be crosslinked and cured with an organic peroxide, and the fluoropolymer composition according to the present invention includes [A] the fluoropolymer described above, and [ B] Contains 0.1 to 10% by weight of an organic peroxide based on the above polymer.

The fluoropolymer used in the present invention can be cured by various conventionally known vulcanization methods, such as peroxy vulcanization using an organic peroxide, de-vulcanization method using a polyamine compound, polyol vulcanization method using a polyhydroxy compound, etc. It can be crosslinked and cured by vulcanization or the like. Among these methods, the peroxide vulcanization method provides excellent heat resistance, chemical resistance, and solvent resistance because the cured fluoropolymer has excellent mechanical strength and the structure of the crosslinking point is a stable carbon-carbon bond. It is particularly preferable because it is excellent in the following properties. It can also be cured by actinic radiation or electron beams.

In this peroxide vulcanization method, the organic peroxide used may be any organic peroxide that generates peroxy radicals under vulcanization conditions, such as 2,5-dimethyl-2,5-
Bis(tert-butylperoxy)hexane, 2,
5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3, benzoyl peroxide, bis(
2,4-dichlorobenzoyl) peroxide, dicumyl peroxide, di-tert-butyl peroxide, t
ert-butylcumyl peroxide, tert-butylperoxybenzene, 1,1-bis(tert-butylperoxy)-3,5,5-)limethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroxy Peroxide, α,α“-bis(tert-butylperoxy)-p-diisopropylbenzene, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane 1
, tert-butylperoxyisopropyl carbonate, etc. are used.

In the peroxide vulcanization method, a polyfunctional unsaturated compound is usually used as a co-crosslinking agent in order to obtain better vulcanization properties, mechanical strength, and compression set. Such co-crosslinking agents include, for example, triallyl isocyanurate, triallyl cyanurate, triallyl trimellitate, N, N'
-m-Funilene bismaleimide, diallyl phthalate, tris(diallylamine)-s-triazine, triallyl phosphite, 1,2-polybutadiene, ethylene diacrylate, diethylene glycol diacrylate, etc. are used.

The amount of organic peroxide and co-crosslinking agent used is usually about 0.1 to 100 parts by weight of the fluoropolymer.
Desirably, the amount is 10 parts by weight, preferably about 0.5 to 5 parts by weight, and the co-crosslinking agent is about 0.1 to 10 parts by weight, preferably about 0.5 to 5 parts by weight.

Further, depending on the purpose, oxides or hydroxides of divalent metals, such as oxides or hydroxides of calcium, magnesium, lead, zinc, etc., can also be used as crosslinking aids. These act as acid acceptors, but may not be used depending on the purpose. When used, it is preferably used in an amount of 15 parts by weight or less per 100 parts by weight of the fluoropolymer.

In addition, each component of the vulcanization system may be blended and kneaded as is, or carbon black, silica, clay, talc,
It may be diluted and dispersed with diatomaceous earth, barium sulfate, etc., or used as a master batch dispersion with a fluoropolymer. Furthermore, in addition to the above-mentioned compounding agents, conventionally known fillers, reinforcing agents, plasticizers, lubricants, processing aids, pigments, etc. can be appropriately compounded. The fluoropolymer of the present invention may also be used with other substances having peroxide crosslinking properties, such as silicone oil, silicone rubber, fluorosilicone rubber, fluorophosphazene rubber, ethylene/vinyl acetate copolymer, ethylene/acrylic acid ester copolymer. ,
It can also be blended and co-crosslinked with ethylene/propylene rubber, acrylonitrile/butadiene rubber, acrylic ester rubber, etc.

Vulcanization is generally carried out by mixing the fluoropolymer with the above-mentioned vulcanization system components and the various additives mentioned above by a commonly used mixing method such as roll mixing, kneader mixing, Banbury mixing, solution mixing, etc., and then heating. It is done by doing. Generally, secondary vulcanization is performed at a temperature of approximately 100 to 250°C for approximately 1 to 120 minutes, and secondary vulcanization is performed at a temperature of approximately 150 to 250°C.
This is done by heating at a temperature of 300°C for about 0 to 30 hours.

The fluorine-containing polymer composition according to the present invention has excellent processability, and has significantly improved vulcanization properties in peroxide vulcanization and vulcanization physical properties (mechanical strength, elongation, heat resistance, compression set, etc.). Therefore, it can be effectively used for the various purposes mentioned above.

Effects of the Invention From the fluoropolymer composition according to the present invention, a crosslinked fluoropolymer having extremely excellent physical properties such as elongation, tensile strength, and compression set can be obtained. In addition, since the fluoropolymer contained in the fluoropolymer composition according to the present invention uses monomers with good copolymerizability during its manufacture, it is possible to improve the efficiency and simplify the manufacturing process. can.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Reference Example 1 Production of 3-bromoperfluoropropyl perfluorovinyl ether 3-bromoperfluoropropyl perfluoropropionyl fluoride 272
g (1,2aol) (hereinafter abbreviated as 3-BPF), and 24g of tetramethylurea (0,21iol
) (hereinafter abbreviated as TMU) and 100m1 of digrime
and 166 g of hexafluoropropene oxide (HFPO) at 40°C while stirring.
(1, Omol) was added in portions.

The product was separated into upper and lower layers and the lower layer was separated.

This lower layer was distilled to give 3-promoperfluoroproboxypropionic acid fluoride (B P P P) at 267
．． 2 g (0.68 iol) was obtained.

BPPP(7)F-NMR of a b Cd e : was measured using CF3COOH as an external standard.

F-NMRa knee 121) palb: 55ppmc:
5pp*d: 56ppm knee 97ppm
f: 4ppvh BPPP3 obtained in this way
9.3 g (0.1 lol) of Na 2 CO
a 42, ' 4 g (0.4 mol), diglyme 200 ml (i') Dropped into a slurry at 180-90°C, then heated to 150°C, and the distillate was taken out under reduced pressure. Distillate was separated into two layers, the lower layer was separated and 17.0 g of 3-bromoperfluoropropoxy perfluorovinyl ether (3-BPVE) (0,
05 mol) was obtained.

bc BrCP2CP2CF20 CF” CF2 (3-B
BPVE ), : BPVE F-NMR of BPPF
It was measured in the same manner.

F-N M Ra knee 11.5ppm d:43.
50,64pp11b: 5L5ppa+ c:8ppffl Reference Example 2 Production of 3-bromoperfluoropropyl perfluorovinyl ether In Reference Example 1, 2-bromoperfluoropropionyl was used instead of 3-bromoperfluoropropionyl fluoride (3-BPF). 2-bromoperfluoropropoxy perfluorovinyl ether (2-bromoperfluoropropoxy perfluorovinyl ether
BPVE) was produced.

a be CP3CF CF2OCF-CF2(2-B PV
E) B "F-N M Ra: 6 ppm d: 42.5
1.63.5ppmb: 28ppm c: 8.5ppm Production Example 1 In an autoclave with an internal volume of 3g, 1500 g of deionized water was added.
ml, 5 g of acetone and 7.5 g of ammonium perfluorooctanoate were added, the pH of the system was adjusted to about 10 with sodium hydroxide, and 1 g of ammonium persulfate was dissolved therein. After that, the system was sufficiently replaced with N2, the autoclave was sufficiently cooled, and tetrafluoroethylene 11
0g.

Perfluoromethyl perfluorovinyl ether (FM
VE) 91.5g, vinylidene 7y 247.5g, 3
-BPVE18. After charging Og, polymerization was carried out at 80° C. with stirring. After 24 hours, the autoclave was cooled and residual gas was released to stop the polymerization.

The resulting aqueous emulsion was salted out with saturated brine, and the resulting solid was washed with water, yielding 406 g of a rubbery polymer. The yield was 87%.

Analysis of this rubbery polymer revealed that vinylidene fluoride/tetrafluoroethylene (VDF)
(TFE)/FMVE-68/2 1
/1 1 (molar ratio) The bromine content of this rubbery polymer was 0.62% by weight.

Production example 2 1500 m of deionized water was added to an autoclave with an internal capacity of 1
1, 5 g of acetone, and 7.5 g of ammonium perfluorooctanoate were added, the pH of the system was adjusted to about 10 with sodium hydroxide, and 1 g of ammonium persulfate was dissolved therein. After that, the system was sufficiently replaced with N2, the autoclave was sufficiently cooled, and tetrafluoroethylene 110
g.

Perfluoromethyl perfluorovinyl ether (FM
VE) 146.3g, vinylidene fluoride 247.5g,
2-BPVE18. After charging Og, polymerization was carried out at 80° C. with stirring. After 24 hours, the autoclave was cooled and residual gas was released to stop the polymerization.

The resulting aqueous emulsion was salted out with saturated brine, and the resulting solid was washed with water, yielding 393 g of a rubbery polymer. The yield was 82%.

Analysis of this rubbery polymer revealed that vinylidene fluoride/tetrafluoroethylene (VDF)
' (TFE)/FMVE-70/19
/11 (molar ratio) The bromine content of this rubbery polymer was 0.53% by weight.

Production Example 3 In an autoclave with an internal volume of 3 fI, 150 ml of deionized water was added.
Add 0ml of acetone, 5g of acetone, 7.5g of ammonium perfluorooctanoate, and adjust the pH of the system with sodium hydroxide.
was prepared to a concentration of about 10, and 1 g of ammonium persulfate was dissolved therein. After that, the inside of the system was sufficiently replaced with N2, and the autoclave was sufficiently cooled.
10g.

, perfluoropropyl perfluorovinyl ether (
FPVE) 146.3g, vinylidene fluoride 247.5
g, 3-BPVElg, and Og were charged, and polymerization was carried out at 80° C. with stirring. After 24 hours, the autoclave was cooled and residual gas was released to stop the polymerization.

The resulting aqueous emulsion was salted out with saturated brine, and the resulting solid was washed with water, yielding 402 g of a rubbery polymer. The yield was 77%.

Analysis of this rubbery polymer revealed that vinylidene fluoride/tetrafluoroethylene (VDF)
(TFE)/FPVE-72/19/
9 (molar ratio) The bromine content of this rubbery polymer was 0.34% by weight.

Production Example 4 In an autoclave with an internal volume of 31, deionized water 1500
ml, 5 g of acetone and 765 g of ammonium perfluorooctanoate were added, the pH of the system was adjusted to about 10 with sodium hydroxide, and 1 g of ammonium persulfate was dissolved therein. After that, the system was sufficiently replaced with N2, and the autoclave was sufficiently cooled.
g1 Perfluoromethyl perfluorovinyl ether (
FMVE) 183 g, 7 Vinylidene fluoride 247.5 g, 3-BPVE lg, Og were prepared,
Polymerization was carried out at 80° C. with stirring. After 24 hours, the autoclave was cooled and residual gas was released to stop the polymerization.

The resulting aqueous emulsion was salted out with saturated brine, and the resulting solid was washed with water, yielding 428 g of a rubbery polymer. The yield was 85%.

Analysis of this rubbery polymer revealed that vinylidene fluoride/tetrafluoroethylene (VDF)
(TFE)/FMVE-67/12/
21 (molar ratio) The bromine content of this rubbery polymer was 0.47% by weight.

Comparative production example 1 In an autoclave with contents 8t31, deionized water 150
Add 0ml of acetone, 5g of acetone, 7.5g of ammonium perfluorooctanoate, and adjust the pH of the system with sodium hydroxide.
was prepared to a concentration of about 10, and 1 g of ammonium persulfate was dissolved therein. After that, the inside of the system was sufficiently replaced with N2, and the autoclave was sufficiently cooled.
:tog.

Perfluoropropyl perfluorovinyl ether (F
PVE) 146.3g, vinylidene fluoride 247.5g
, 8.9 g of bromotetrafluoroethylene were charged, and polymerization was carried out at 80° C. with stirring. After 24 hours, the autoclave was cooled and residual gas was released to stop the polymerization.

The resulting aqueous emulsion was salted out with saturated brine, and the resulting solid was washed with water, yielding 364 g of a rubbery polymer. The yield was 87%.

Analysis of this rubbery polymer revealed that vinylidene fluoride/tetrafluoroethylene (VDF)
(TFE)/FPVE-68/23/
9 (molar ratio) The bromine content of this rubbery polymer was 0.26% by weight.

Comparative Production Example 2 In an autoclave with an internal volume of 3 g, 1500 g of deionized water was added.
ml, 5 g of acetone and 7.5 g of ammonium perfluorooctanoate were added, the pH of the system was adjusted to about 10 with sodium hydroxide, and 1 g of ammonium persulfate was dissolved therein. After that, the system was sufficiently replaced with N2, the autoclave was sufficiently cooled, and tetrafluoroethylene 11
0g.

perfluoropropyl perfluorovinylethe/I,
(FPVE) 146.3g, vinylidene fluoride 247.
5g of bromotetrafluorobutylene and 11.3g of bromotetrafluorobutylene were charged, and polymerization was carried out at 80°C with stirring. After 24 hours, the autoclave was cooled and residual gas was released to stop the polymerization.

The resulting aqueous emulsion was salted out with saturated brine, and the resulting solid was washed with water, yielding 319 g of a rubbery polymer. The yield was 62%.

Analysis of this rubbery polymer revealed that vinylidene fluoride/tetrafluoroethylene (VDF)
(TFE)/FPVE-65/24/
1 1 (molar ratio) The bromine content of this rubbery polymer was 0.31% by weight.

Comparative Production Example 3 In an autoclave with an internal volume of 3 g, 1500 g of deionized water was added.
ml, 5 g of acetone and 7.5 g of ammonium perfluorooctanoate were added, the pH of the system was adjusted to about 10 with sodium hydroxide, and 1 g of ammonium persulfate was dissolved therein. After that, the system was sufficiently replaced with N2, the autoclave was sufficiently cooled, and tetrafluoroethylene 11
0g.

Perfluoropropyl perfluorovinyl ether (F
PVE) 91.5g, hiniritene heptadide 247.5g,
Iodoperfluoroethyl perfluorovinyl ether (IEVE, chemical formula % Formula %) was charged and polymerization was carried out at 80°C with stirring. After 24 hours,
Polymerization was stopped by cooling the autoclave and releasing residual gas.

The resulting aqueous emulsion was salted out with saturated brine, and the resulting solid was washed with water, yielding 203 g of a rubbery polymer. The yield was 39%.

Analysis of this rubbery polymer revealed that vinylidene fluoride/tetrafluoroethylene (VDF)
(TFE)/FPVE-67/21/
12 (molar ratio) The bromine content of this rubbery polymer was 0.75% by weight.

Comparative Production Example 4 In an autoclave with an internal volume of 3 g, 1500 g of deionized water was added.
ml, acetone 5 g, and ammonium perfluorooctanoate 7.5 g, and remove the p in the system with sodium hydroxide.
H was adjusted to about 10, and 1 g of ammonium persulfate was dissolved therein. After that, the system was sufficiently replaced with N2, and the autoclave was sufficiently cooled, and then 1 iog of tetrafluoroethylene was added.

Perfluoropropyl perfluorovinyl ether (F
PVE) 146.3g, vinylidene fluoride 247.5g
, Bromoperfluoroethyl perfluorovinyl ether (BEVE, chemical formula % Formula %) was charged and polymerization was carried out at 80°C with stirring. After 24 hours,
Polymerization was stopped by cooling the autoclave and releasing residual gas.

The resulting aqueous emulsion was salted out with saturated brine, and the resulting solid was washed with water, yielding 422 g of a rubbery polymer. The yield was 81%.

Analysis of this rubbery polymer revealed that vinylidene fluoride/tetrafluoroethylene (VDF)
(TFE)/FPVE-71/21/
8 (molar ratio) The bromine content of this rubbery polymer was 0.60% by weight.

The above is summarized in Table 1.

In addition, the viscosity ηsp/c of the rubbery polymers obtained in Production Examples 1 to 4 and Comparative Production Examples 1 to 4 above was determined by dissolving the polymer in methyl ethyl ketone at 30°C in an amount of 0.25 g/25 ml. It was measured using an Ubbelohde viscometer.

Furthermore, the solubility of each polymer in methyl ethyl ketone was investigated.

The results are shown in Table 2.

Table 2 0: Completely dissolved x D Some insoluble matter is present Example 1 20 parts by weight of MT-carbon, 2.5-dimethyl- 2,5-di(t-butylperoxy)hexane 1
5 parts by weight of triallylisocyanurate and 4 parts by weight of triallyl isocyanurate were blended and kneaded with a roll to prepare a curable fluoropolymer composition.

Next, this composition was press-vulcanized at 160° C. for 10 minutes, and then heated and vulcanized in an oven at 180° C. for 4 hours to obtain sheet-like and O-ring-like vulcanized products.

The physical properties of each vulcanizate were measured according to JIS K-6310. The compression set was measured by compressing a wire diameter of 3.5+amP-240-ring by 25% (at 200° C. for 70 hours).

Processability was evaluated by visually determining the cross-contact state of the filler and the like on the two rolls.

The rate of change in tensile strength is a value obtained by aging the vulcanized rubber in a high-temperature oven at 230°C for 70 hours, measuring the tensile strength according to JISK-6301, and determining the rate of change in breaking strength before and after aging.

The results are shown in Table 3.

Example 2 The physical properties of the vulcanizate were measured in the same manner as in Example 1, except that the rubbery fluoropolymer obtained in Production Example 2 was used.

The results are shown in Table 3.

Example 3 The physical properties of the vulcanizate were determined at 11FJ in the same manner as in Example 1, except that the rubbery fluoropolymer obtained in Production Example 3 was used.

The results are shown in Table 3.

Example 4 The physical properties of the vulcanizate were measured in the same manner as in Example 1, except that the rubbery fluoropolymer obtained in Production Example 4 was used.

The results are shown in Table 3.

Comparative Example 1 The physical properties of the vulcanizate were measured in the same manner as in Example 1, except that the rubbery fluoropolymer obtained in Comparative Production Example 1 was used.

The results are shown in Table 3.

Comparative Example 2 The physical properties of the vulcanizate were measured in the same manner as in Example 1, except that the rubbery fluoropolymer obtained in Comparative Production Example 2 was used.

The results are shown in Table 3.

Comparative Example 3 The physical properties of the vulcanizate were measured in the same manner as in Example 1, except that the rubbery fluoropolymer obtained in Comparative Production Example 3 was used.

The results are shown in Table 3.

Comparative Example 4 The physical properties of the vulcanizate were measured in the same manner as in Example 1, except that the rubbery fluoropolymer obtained in Comparative Production Example 4 was used.

The results are shown in Table 3.

Claims (1)

[Scope of Claims] 1) [A] (1) 3-bromoperfluoropropyl perfluorovinyl ether or 2-bromoperfluoropropyl perfluorovinyl ether; (2) copolymerizable with the above perfluoropropyl perfluorovinyl ether; A fluorine-containing copolymer obtained by copolymerizing a fluorine-containing monomer having 2 to 8 carbon atoms such that the perfluoropropyl vinyl ether is present in the copolymer in an amount of 0.01 to 5 mol%, and [B] 0.1 to 10% by weight based on the above copolymer [A]
A curable fluoropolymer composition comprising an organic peroxide.