RU2800383C2 - Fluorine-containing copolymer and method of its manufacture - Google Patents

Abstract

FIELD: copolymers.

SUBSTANCE: present invention relates to a fluorinated copolymer having excellent low temperature properties and cross-linking ability, and a method for producing the same. Described is a fluorinated copolymer that has units based on tetrafluoroethylene, units based on propylene and units based on at least one of CF₂=CFOCF₂CF₂OCF₂OCF₂OCF₃ and CF₂=CFOCF₂CF₂OCF₂CF₂OCF₂CF₃ or which has units based on vinylidene fluoride and units based on at least one of CF₂=CFOCF₂CF₂OCF₂OCF₂OCF₃ and CF₂=CFOCF₂CF₂OCF₂CF₂OCF₂CF₃ and which has either one or both of iodine atoms and bromine atoms. Also described is a method for the production of a fluorinated copolymer, which includes the polymerization of a monomer component containing tetrafluoroethylene, propylene and at least one compound from CF₂=CFOCF₂CF₂OCF₂OCF₂OCF₃ and CF₂=CFOCF₂CF₂OCF₂CF₂OCF₂CF₃, or a monomeric component containing vinylidene fluoride and at least one compound from CF₂=CFOCF₂CF₂OCF₂OCF₂OCF₃ and CF₂=CFOCF₂CF₂OCF₂CF₂OCF₂CF₃, where, at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom, and a chain transfer agent containing either one or both of an iodine atom and a bromine atom must be present in the system polymerization.

EFFECT: obtaining a fluorinated copolymer with improved low-temperature properties and cross-linking ability.

15 cl, 4 tbl, 12 ex

Description

Technical field

[0001]

The present invention relates to a fluorinated copolymer and to a process for its production.

State of the art

[0002]

Fluororubbers, which are excellent in terms of heat resistance, chemical resistance, oil resistance, weather resistance, etc., are suitable for use in harsh environments in which general purpose rubbers cannot be used.

As fluororubbers, for example, a copolymer (FKM) having units based on vinylidene fluoride and units based on hexafluoropropylene and a copolymer (FEPM) having units based on tetrafluoroethylene and units based on propylene are known.

For the use of fluororubbers at low temperature, it is required to improve the physical properties of fluororubbers at low temperature (hereinafter, sometimes referred to as low temperature properties).

[0003]

As FEPM, the low temperature properties of which are improved, the following copolymer is proposed:

Fluorinated copolymer having at least 50 mol%. and less than 60 mol%. units based on tetrafluoroethylene, at least 10 mol%. and less than 40 mol%. links based on propylene, and at least 10 mol%. and less than 40 mol%. units based on CH ₂ =CHO(CH ₂ ) _m (CF ₂ ) _n F (where m is 2 and n is 5 or 6), and having a glass transition temperature of -30 to -7°C (Patent Document 1).

Prior Art Document

Patent Documents

[0004]

Patent Document 1: Japanese Patent No. 5407180

Description of the invention

Technical task

[0005]

The fluororubber is generally used in the form of a crosslinked product obtained by crosslinking a composition containing a crosslinker, a crosslinking auxiliary, etc., mixed with the fluororubber to improve mechanical properties (such as tensile strength and high temperature compression set), etc. However, the fluorinated copolymer disclosed in Patent Document 1, which does not contain crosslinking moieties such as iodine atoms, has problems with crosslinkability .

[0006]

In order to improve the crosslinkability of the fluorinated copolymer, the introduction of iodine atoms into the fluorinated copolymer by using a chain transfer agent containing an iodine atom during polymerization of the monomers constituting the fluorinated copolymer is considered. However, if a chain transfer agent containing an iodine atom is used during the polymerization of the monomers constituting a fluorinated copolymer as described in Patent Document 1, the CH ₂ =CHO(CH ₂ ) _m (CF ₂ ) _n F component is generally difficult to copolymerize, and the resulting fluorinated copolymer generally has insufficient low temperature properties.

[0007]

The present invention provides, as a fluororubber, a fluorinated copolymer having excellent low temperature properties and crosslinkability, and a method for producing the same.

The solution of the problem

[0008]

The present invention provides the following.

<1> A fluorinated copolymer which has tetrafluoroethylene-based units, propylene-based units, and units based on the compound represented by the following formula 1, or which has vinylidene fluoride-based units and units based on the compound represented by the following formula 1, and which has either one or both of iodine atoms and bromine atoms:

CF ₂ =CFO(R ^f1 O) _n R ^f2 Formula 1,

where R ^f1 is a C _1-3 perfluoroalkylene group, R ^f2 is a C _1-6 perfluoroalkyl group, n is an integer from 1 to 4, and when n is from 2 to 4, the plurality of R ^f1 substituents may be the same or different.

<2> The fluorinated copolymer according to <1>, which is a fluorinated copolymer which has tetrafluoroethylene-based units, propylene-based units, and units based on the compound represented by the following formula 1, and which has either one or both of iodine atoms and bromine atoms:

CF ₂ =CFO(R ^f1 O) _n R ^f2 Formula 1,

where R ^f1 is a C _1-3 perfluoroalkylene group, R ^f2 is a C _1-6 perfluoroalkyl group, n is an integer from 1 to 4, and when n is from 2 to 4, the plurality of R ^f1 substituents may be the same or different.

<3> The fluorinated copolymer according to <1> or <2>, wherein, relative to the total number of moles of tetrafluoroethylene-based units, propylene-based units, and units based on the compound represented by formula 1, the content of tetrafluoroethylene-based units is 35 to 65 mol%, the content of propylene-based units is 20 to 50 mol%. and the content of units based on the compound represented by formula 1 is from 2 to 15 mol%, and

relative to the total weight of units based on tetrafluoroethylene, units based on propylene and units based on the compound represented by formula 1, the content of units based on the compound represented by formula 1 is from 10 to 50% of the mass.

<4> The fluorinated copolymer according to any one of <1>-<3>, wherein the content of X1 mol %. units based on the compound represented by formula 1, relative to the total number of moles of units based on tetrafluoroethylene, units based on propylene and units based on the compound represented by formula 1, and the glass transition temperature Y1°C of the fluorinated copolymer, satisfy the ratio Y1/X1≤-0.8.

<5> The fluorinated copolymer according to any one of <1> to <4>, which further has units based on a monomer having at least two polymerizable unsaturations.

<6> The fluorinated copolymer according to <1>, which is a fluorinated copolymer which has units based on vinylidene fluoride and units based on the compound represented by the following formula 1, and which has either one or both of iodine atoms and bromine atoms:

CF ₂ =CFO(R ^f1 O) _n R ^f2 Formula 1,

where R ^f1 is a C _1-3 perfluoroalkylene group, R ^f2 is a C _1-6 perfluoroalkyl group, n is an integer from 1 to 4, and when n is from 2 to 4, the plurality of R ^f1 substituents may be the same or different.

<7> The fluorinated copolymer according to <6>, which further has units based on another monomer.

<8> The fluorinated copolymer according to <6>, wherein, relative to the total number of moles of units based on vinylidene fluoride and units based on the compound represented by Formula 1, the content of units based on vinylidene fluoride is 86 to 96 mol %, and the content of units based on the compound represented by Formula 1 is 4 to 14 mol %, and

relative to the total weight of units based on vinylidene fluoride and units based on the compound represented by formula 1, the content of units based on the compound represented by formula 1 is from 10 to 50% of the mass.

<9> Fluorinated copolymer in accordance with any one of paragraphs <6>-<8>, where the content of X2 mol%. of units based on the compound represented by formula 1, relative to the total number of moles of units based on vinylidene fluoride, units based on the compound represented by formula 1, and units based on another monomer, if present, the glass transition temperature Y2°C of the fluorinated copolymer and the glass transition temperature Y3°C of the fluorinated copolymer having units constituting the fluorinated copolymer, excluding units based on the compound represented by formula 1, satisfy the relationship (Y 2-Y3)/X2≤-0.8.

<10> The fluorinated copolymer according to <7> or <9>, wherein the other monomer is hexafluoropropylene.

<11> The fluorinated copolymer according to <7> or <9>, wherein the other monomer is a monomer having at least two polymerizable unsaturations.

<12> The fluorinated copolymer according to any one of <1> to <11>, which has a shear modulus G' of 10 to 800 kPa.

<13> The fluorinated copolymer according to any one of <1> to <12>, wherein the total content of iodine atoms and bromine atoms relative to the weight of the fluorinated copolymer is 0.01 to 5.00 mass%.

<14> A method for producing a fluorinated copolymer that includes polymerizing a monomer component containing tetrafluoroethylene, propylene and a compound represented by the following formula 1, or a monomer component containing vinylidene fluoride and a compound represented by the following formula 1,

where at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom, and a chain transfer agent containing either one or both of an iodine atom and a bromine atom must be present in the polymerization system:

CF ₂ =CFO(R ^f1 O) _n R ^f2 Formula 1,

where R ^f1 is a C _1-3 perfluoroalkylene group, R ^f2 is a C _1-6 perfluoroalkyl group, n is an integer from 1 to 4, and when n is from 2 to 4, the plurality of R ^f1 substituents may be the same or different.

<15> The method for producing a fluorinated copolymer according to <14>, which includes polymerizing a monomer component containing tetrafluoroethylene, propylene, and a compound represented by the following formula 1,

where at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom, and a chain transfer agent containing either one or both of an iodine atom and a bromine atom must be present in the polymerization system:

CF ₂ =CFO(R ^f1 O) _n R ^f2 Formula 1,

where R ^f1 is a C _1-3 perfluoroalkylene group, R ^f2 is a C _1-6 perfluoroalkyl group, n is an integer from 1 to 4, and when n is from 2 to 4, the plurality of R ^f1 substituents may be the same or different.

<16> The method for producing a fluorinated copolymer according to <14>, which includes polymerizing a monomer component containing vinylidene fluoride and a compound represented by the following formula 1,

where at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom, and a chain transfer agent containing either one or both of an iodine atom and a bromine atom must be present in the polymerization system:

CF ₂ =CFO(R ^f1 O) _n R ^f2 Formula 1,

where R ^f1 is a C _1-3 perfluoroalkylene group, R ^f2 is a C _1-6 perfluoroalkyl group, n is an integer from 1 to 4, and when n is from 2 to 4, the plurality of R ^f1 substituents may be the same or different.

<17> The method for producing a fluorinated copolymer according to <16>, which includes polymerizing a monomer component containing vinylidene fluoride, a compound represented by the following formula 1, and another monomer,

where at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom, and a chain transfer agent containing either one or both of an iodine atom and a bromine atom must be present in the polymerization system:

CF ₂ =CFO(R ^f1 O) _n R ^f2 Formula 1,

where R ^f1 is a C _1-3 perfluoroalkylene group, R ^f2 is a C _1-6 perfluoroalkyl group, n is an integer from 1 to 4, and when n is from 2 to 4, the plurality of R ^f1 substituents may be the same or different.

Useful effects of the invention

[0009]

The fluorinated copolymer of the present invention as a fluoroelastomer has excellent low temperature properties and crosslinkability.

According to the production method of the fluorinated copolymer of the present invention, as a fluororubber, a fluorinated copolymer excellent in terms of low temperature properties and crosslinkability can be produced.

Description of Embodiments

[0010]

In the present description, the following terms have the following meanings.

"Monomer" means a compound having a polymerizable unsaturation. The polymerizable unsaturation, for example, may be a double bond or a triple bond between carbon atoms.

"Monomer-based units" generally means a group of atoms directly formed by the polymerization of one molecule of a monomer, and a group of atoms obtained by chemical transformation of a part of the group of atoms. Monomer-based units may sometimes be referred to as "monomeric units".

"The end of the molecular chain" includes both the end of the main chain and the end of the branches.

An "etheric oxygen atom" is an oxygen atom that sits alone between carbon atoms.

"Shear modulus G'" is a value measured in accordance with ASTM D5289 and ASTM D6204 at 100°C, amplitude 0.5°, and a frequency of 50 per minute.

"Glass Transition Temperature" means the midpoint of the glass transition temperature measured by differential scanning calorimetry (DSC) according to JIS K6240:2011 (corresponding to international standard ISO 22768:2006).

[0011]

Copolymer 1

The fluorinated copolymer of the present invention according to the first embodiment (hereinafter, sometimes referred to as “copolymer 1”) has units based on tetrafluoroethylene (hereinafter, sometimes referred to as “TFE” (TFE)) (hereinafter, sometimes referred to as “TFE units”), propylene-based units (hereinafter, sometimes referred to as “P units”), and units based on the compound 1 represented by formula 1 (hereinafter, sometimes referred to as “compound 1 units”), and has either one or both of iodine atoms and bromine atoms.

[0012]

Due to the presence of units of compound 1 represented by formula 1, copolymer 1 has excellent low temperature properties.

CF ₂ =CFO(R ^f1 O) _n R ^f2 Formula 1,

where R ^f1 is a C _1-3 perfluoroalkylene group, R ^f2 is a C _1-6 perfluoroalkyl group, n is an integer from 1 to 4, and when n is from 2 to 4, the plurality of R ^f1 substituents may be the same or different.

[0013]

The perfluoroalkylene group as substituent R ^f1 may be linear or branched. The perfluoroalkyl group as substituent R ^f2 may be linear or branched.

The number of carbon atoms in the R ^f2 substituent is preferably an integer from 1 to 3. Preferably n is an integer from 1 to 3.

When the number of carbon atoms in the substituent R ^f1 , the number of carbon atoms in the substituent R ^f2 and n are within the above ranges, the production efficiency of the copolymer 1 improves, and the copolymer 1 will have excellent low temperature properties.

[0014]

As Compound 1, for example, the following compounds can be mentioned.

CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ (hereinafter referred to as "C7-PEVE"),

CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ (hereinafter referred to as "EEAVE"),

CF ₂ \u003d CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ ,

CF ₂ =CFOCF ₂ CF(CF ₃ )OCF ₂ CF ₂ CF ₃ (hereinafter referred to as "PHVE"),

CF ₂ \u003d CFOCF ₂ CF ₂ OCF ₃ ,

CF ₂ \u003d CFOCF ₂ CF ₂ CF ₂ OCF ₃ ,

CF ₂ \u003d CFOCF ₂ CF ₂ OCF ₂ CF ₃ ,

CF ₂ \u003d CFOCF ₂ OCF ₃ ,

CF ₂ \u003d CFOCF ₂ OCF ₂ CF ₃ ,

CF ₂ \u003d CFOCF ₂ OCF ₂ CF ₂ OCF ₃ ,

CF ₂ =CFO(CF ₂ CF(CF ₃ )O) ₂ CF ₂ CF ₂ CF ₃ and

CF ₂ = CFOCF ₂ OCF ₂ OCF ₃ .

[0015]

As Compound 1, C7-PEVE, EEAVE or PHVE are preferred from the viewpoint of improving the production efficiency of Copolymer 1 and excellent low temperature properties of Copolymer 1.

Compound 1 may be used alone or in combination of two or more.

Compound 1 can be prepared using the appropriate alcohol as starting material according to the method disclosed in WO 00/56694.

[0016]

Copolymer 1 may have units based on a monomer other than TFE, propylene, and compound 1 (hereinafter sometimes referred to as "other monomer").

The other monomer may be, for example, a monomer having at least two polymerizable unsaturations (hereinafter sometimes referred to as "DV"), perfluoro(alkyl vinyl ether) (hereinafter sometimes referred to as "PAVE"), hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene, vinyl fluoride, pentafluoropropylene, perfluorocyclobutene, 2,3,3,3-tetrafluoropropene, (perfluoroalkyl)ethylene (such like CH₂=CHCF₃, CH₂=CHCF₂CF₃, CH₂=CHCF₂CF₂CF₃, CH₂=CHCF₂CF₂CF₂CF₃ or CH₂=CHCF₂CF₂CF₂CF₂CF₃), an α-olefin (such as ethylene, isobutylene, or pentene), a vinyl ether (such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, or butyl vinyl ether), a vinyl ester (such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, or vinyl caprylate), a monomer having either one or both of a bromine atom and an iodine atom, a monomer having a nitrile group (that coy as CF₂=CFO(CF₂)₅CN or perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene)).

[0017]

As the monomer having either one or both of a bromine atom and an iodine atom, preferably the compound represented by the following formula 2 (hereinafter, sometimes referred to as "compound 2"), or the compound represented by formula 3 (hereinafter, sometimes referred to as "compound 3"):

CR ¹ R ² =CR ³ R ⁴ Formula 2

CR ¹ R ² -R ⁵ -CR ³ R ⁴ Formula 3,

with the proviso that compound 2 and compound 3 have at least one bromine atom or iodine atom.

The substituents R ¹ , R ² and R ³ are each independently a hydrogen atom, a fluorine atom, a bromine atom or an iodine atom.

The R ⁴ substituent is an alkyl group, an alkyl group having one or more ether oxygen atoms, a fluoroalkyl group, or a fluoroalkyl group having one or more ether oxygen atoms. The R ⁴ substituent may contain a bromine atom or an iodine atom. The R ⁴ substituent may be linear or branched.

The R ⁵ substituent is a group having at least one polymerizable unsaturation. The polymerizable unsaturation may be linked to an alkyl group, an alkyl group having one or more ether oxygen atoms, a fluoroalkyl group, or a fluoroalkyl group having one or more ether oxygen atoms. The R ⁵ substituent may have a bromine atom or an iodine atom. The R ⁵ substituent may be linear or branched.

[0018]

As Compound 2 and Compound 3, more specifically, the following compounds may be mentioned:

iodoethylene, 4-iodine-3,3,4,4-tetrafluoro-1-butene, 2-iodine-1,1,2,2-tetrafluoro-1-vinyloxyethane, 2-iodoethylvinyl ether, allyl iodide, 1,1,2,3,3,3-hexafluoro-2-iodine-1-(perfluorovinyloxy)-propane, 3,3,4,5,5,5-hexa fluoro _- 4-iodopentene, iodotrifluoroethylene, 2-iodoperfluoro(ethyl vinyl ether), CF ₂ ═CFOCF(CF ₃ )CF 2 OCF ₂ CF ₂ CH ₂ I, CF ₂ ═CFOCF ₂ CF ₂ CH ₂ I and CH ₂ ═CHCF ₂ CF ₂ I;

bromotrifluoroethylene, 4-bromo-3,3,4,4-tetrafluorobutene-1 (hereinafter sometimes referred to as "BTFB"), vinyl bromide, 1-bromo-2,2-difluoroethylene, perfluoroallyl bromide, 4-bromo-1,1,2-trifluorobutene-1, 4-bromo-1,1,3,3,4,4-hexafluorobutene, 4-bromo-3-chloro -1,1,3,4,4-pentafluoro-butene, 6-bromo-5,5,6,6-tetrafluorohexene, 4-bromoperfluorobutene-1,3,3-difluoroallyl bromide, 2-bromoperfluoroethyl perfluorovinyl ether, CF₂=CFOCF₂CF₂CF₂OCF₂CF₂Br, CF₂BrCF₂O-CF=CF₂, CH₃OCF=CFBr and CF₃CH₂OCF=CFBr;

3-bromo-4-iodoperfluorobutene-1, 2-bromo-4-iodoperfluorobutene-1.

As Compound 2, BTFB is preferred.

[0019]

The other monomer may be used alone or in combination of two or more.

As the other monomer, DV or PAVE is preferred, and DV is more preferred.

When copolymer 1 has DV-based units (hereinafter referred to as "DV units"), copolymer 1 will have better crosslinkability, and the crosslinked product of copolymer 1 will have more excellent mechanical properties.

[0020]

The polymerizable unsaturation in DV may be, for example, a double bond or a triple bond between carbon atoms, and is preferably a double bond. The number of polymerizable unsaturations in DV is preferably 2 to 6, more preferably 2 or 3, also preferably 2.

As the DV, at least one selected from the group consisting of a compound represented by formula 4 (hereinafter referred to as "compound 4"), a compound represented by formula 5 (hereinafter referred to as "compound 5"), and a compound represented by formula 6 (hereinafter referred to as "compound 6") is preferable:

CR ⁶ R ⁷ =CR ⁸ -R ⁹ -CR ¹⁰ =CR ¹¹ R ¹² Formula 4

CR ¹³ R ¹⁴ =CR ¹⁵ -OC(O)-R ¹⁶ -C(O)O-CR ¹⁷ =CR ¹⁸ R ¹⁹ Formula 5

CR ²⁰ R ²¹ =CR ²² -C(O)O-CH=CH ₂ Formula 6.

[0021]

The substituents R ⁶ , R ⁷ , R ⁸ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁷ , R ¹⁸ , R ¹⁹ and R ²² each independently represent a hydrogen atom, a fluorine atom or a methyl group.

The R ⁹ and R ¹⁶ substituents are each independently a C _1-10 alkylene group, a C _1-10 alkylene group having one or more ether oxygen atoms, a C _1-10 fluoroalkylene group, or a C _1-10 fluoroalkylene group having one or more ether oxygen atoms.

The R ²⁰ and R ²¹ substituents are each independently a hydrogen atom, a C _1-10 alkyl group, or a C _1-10 alkyl group having one or more ether oxygen atoms.

[0022]

As compound 4, there may be mentioned a compound having a C _1-10 alkylene group or a fluoroalkylene group at both ends, a group independently selected from a vinyl group, an allyl group and a butenyl group, linked through or without one or more ether oxygen atoms. As examples of the compound having one or more etheric oxygen atoms, divinyl ether, allyl vinyl ether, butenyl vinyl ether, fluoro(divinyl ether), fluoro(allyl vinyl ether) and fluoro(butenyl vinyl ether) can be mentioned.

[0023]

In compound 4, from the viewpoint of improving the crosslinkability of copolymer 1 and the heat resistance of the crosslinked product of copolymer 1, the substituents R ⁶ , ^{R 7 ,} R ⁸ , R 10 , R ¹¹ and R ¹² are each independently preferably a fluorine atom or a hydrogen atom, and more preferably all of the substituents R ⁶ , R ⁷ , R ⁸ , R ¹⁰ , R ¹¹ and R ¹² are atoms fluorine.

The alkylene group or the fluoroalkylene group as substituent R ⁹ may be linear or branched, and preferably linear. The number of carbon atoms in the R ⁹ substituent is preferably 2 to 8, more preferably 3 to 7, also preferably 3 to 6, particularly preferably 3 to 5. The number of ether oxygen atoms in R ⁹ is preferably 0 to 3, more preferably 1 or 2. When the R ⁹ substituent is in such a preferred embodiment, the crosslinked product of copolymer 1 will have more excellent mechanical properties.

The substituent R ⁹ is preferably a fluoroalkylene group, more preferably a perfluoroalkylene group, from the point of view of heat resistance of the crosslinked product of the copolymer 1 and from the point of view of suppressing coloring.

[0024]

As compound 4, for example, the following compounds can be mentioned:

CH ₂ \u003d CHO (CH ₂ ) ₄ OCH \u003d CH ₂ ,

CF ₂ =CFO(CF ₂ ) ₃ OCF=CF ₂ (hereinafter sometimes referred to as "DVE-3"),

CF ₂ =CFO(CF ₂ ) ₄ OCF=CF ₂ (hereinafter sometimes referred to as "DVE-4"), and

CH ₂ =CH(CF ₂ ) ₆ CH=CH ₂ .

[0025]

As compound 5, for example, divinyl ester, allyl vinyl ester or butenyl vinyl ester can be mentioned.

In compound 5, the substituents R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁷ , R ¹⁸ and R ¹⁹ are preferably hydrogen atoms.

As the R ¹⁶ substituent, the same groups can be mentioned as the R ⁹ substituent. The preferred range for the number of carbon atoms in R ¹⁶ is also the same as for the substituent R ⁹ . The number of ether oxygen atoms in R ¹⁶ is preferably 0 or 1, more preferably 0.

As compound 5, for example, divinyl adipate can be mentioned.

[0026]

In compound 6, R ²¹ and R ²² are preferably hydrogen atoms.

Compound 6 is preferably, for example, vinyl crotonate or vinyl methacrylate and preferably vinyl crotonate.

As DV, from the point of view of more excellent crosslinkability while maintaining the mechanical properties of the crosslinked product of copolymer 1, DVE-3 or DVE-4 is preferable.

DV can be used alone or in combination of two or more.

[0027]

As PAVE, for example, the compound represented by formula 7 (hereinafter referred to as "compound 7") can be mentioned:

CF ₂ =CFOR ^f3 Formula 7,

where R ^f3 is a C _1-10 perfluoroalkyl group.

The perfluoroalkyl group as R ^f3 substituent may be linear or branched. The number of carbon atoms in R ^f3 is preferably 1 to 8, more preferably 1 to 6, also preferably 1 to 5, particularly preferably 1 to 3.

As compound 7, for example, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether) or perfluoro(propyl vinyl ether) can be mentioned.

PAVE can be used alone or in combination of two or more.

[0028]

The content of TFE units relative to the total number of moles of TFE units, P units and units of compound 1 is preferably 35 to 65 mol%, more preferably 40 to 60 mol%, also preferably 45 to 55 mol%.

The content of P units relative to the total number of moles of TFE units, P units and units of compound 1 is preferably 20 to 50 mol %, more preferably 30 to 47 mol %, also preferably 40 to 45 mol %.

When the contents of TFE units and P units are within the ranges described above, the copolymer 1 will have superior mechanical properties, heat resistance, chemical resistance (alkali resistance or the like), oil resistance, and weather resistance.

[0029]

The content of links of connection 1 relative to the total number of moles of TFE links, P links and links of compound 1 is preferably from 2 to 15 mol%, more preferably from 3 to 13 mol%, also preferably from 5 to 12 mol%.

The content of links of compound 1 relative to the total weight of TFE links, P links and links of compound 1 is preferably from 10 to 50 wt. -%, more preferably from 8 to 45 wt. -%, also preferably from 5 to 40 wt.

When the mole and weight content of compound 1 units is at least equal to the lower limit values of the above ranges, copolymer 1 will have superior low temperature properties. When the content of compounds 1 in molar and mass values is at most the upper limit values of the above ranges, the mechanical properties and production efficiency will be excellent.

[0030]

The total number of moles of TFE units, P units and units of compound 1 relative to all units forming copolymer 1 is preferably from 50 to 100 mol%, more preferably from 60 to 100 mol%, also preferably from 70 to 100 mol%.

In the case where copolymer 1 has DV units, the content of DV units relative to the total number of moles of TFE units, P units and units of compound 1 is preferably 0.1 to 1.0 mole %, more preferably 0.15 to 0.8 mole %, also preferably 0.2 to 0.6 mole %. When the content of DV units is equal to at least the lower limit value of the range described above, copolymer 1 will have excellent crosslinkability, and the crosslinked product of copolymer 1 will have more excellent mechanical properties (such as tensile strength and compression set at high temperature). When the content of DV units is at most the upper limit value of the above-described range, while maintaining excellent physical properties of the crosslinked product of copolymer 1, fracture is suppressed when stress such as bending is applied at a high temperature.

[0031]

Due to the presence of either one or both of iodine atoms and bromine atoms, copolymer 1 will have excellent crosslinkability. The iodine atoms or bromine atoms are preferably attached to the end of the molecular chain of copolymer 1.

The total content of iodine atoms and bromine atoms relative to the weight of the copolymer 1 is preferably from 0.01 to 5.00 wt%, more preferably from 0.03 to 2.00 wt%, also preferably from 0.05 to 1.00 wt%. When the total content of iodine atoms and bromine atoms is within the range described above, the copolymer 1 will have more excellent crosslinkability and mechanical properties.

[0032]

The glass transition temperature (hereinafter sometimes referred to as “T _g ”) of copolymer 1 is a measure of the low temperature properties of copolymer 1. T _{g of} copolymer 1 is preferably at most -3°C, more preferably at most -5°C, also preferably at most -10°C. When the T _{st of} the copolymer 1 is at most the upper limit of the range described above, the copolymer 1 will have more excellent low temperature properties. The T _st of the copolymer 1 is preferably as low as possible, and the lower limit is not particularly limited, and from the viewpoint of processability and mechanical properties, the T _st of the copolymer 1 is preferably at least -50°C.

[0033]

Preferably, the content (X1 mol.) of units of compound 1 relative to the total number of moles of TFE units, P units and units of compound 1 and T _st (Y1°C) of copolymer 1 satisfies the ratio Y1/X1≤-0.8, more preferably the ratio Y1/X1≤-1.0, also preferably Y1/X1≤-1.5.

Since the T _st of conventional FEPM (TFE-propylene copolymer, ((TFE units):(propylene units) = 56:44)) is essentially 0°C, the ratio Y1/X1≤-0.8, when it is satisfied, means that due to the introduction of 1% mol. of compounds 1 into conventional FEPM, the T _of the resulting copolymer 1 falls by at least 0.8°C compared to conventional FEPM, that is, compound 1 is a compound effective to reduce the T _of copolymer 1 by at least 0.8°C when it is introduced in an amount of 1 mol %. As such compound 1, C7-PEVE, EEAVE or PHVE can be mentioned.

[0034]

The shear modulus G' of copolymer 1 is preferably 10 to 800 kPa, more preferably 50 to 600 kPa, also preferably 80 to 500 kPa. A higher shear modulus G' means a higher polymer molecular weight and a higher molecular chain weave density. When the shear modulus G' of copolymer 1 is within the range described above, processability and mechanical properties (such as tensile strength) will be much better.

[0035]

Copolymer 2

The fluorinated copolymer of the present invention according to the second embodiment (hereinafter referred to as "copolymer 2") has units based on vinylidene fluoride (hereinafter referred to as "VdF") (hereinafter referred to as "VdF units") and compound 1 units, and has either one or both of iodine atoms and bromine atoms.

[0036]

Due to the presence of units of compound 1, copolymer 2 will have excellent low temperature properties.

As compound 1, the same compound as compound 1 for copolymer 1 may be mentioned, and the same options are also preferred.

[0037]

Copolymer 2 may have units based on a monomer other than VdF and Compound 1 (hereinafter referred to as "other monomer").

As the other monomer, for example, hexafluoropropylene (hereinafter sometimes referred to as "HFP"), DV, chlorotrifluoroethylene, TFE, vinyl fluoride, ethylene, ethylidene norbornene, vinylcrotonate, Compound 2, Compound 3, and a monomer having a nitrile group can be mentioned. The other monomer may be used alone or in combination of two or more.

[0038]

As the other monomer, HFP or DV is preferred.

When copolymer 2 has HFP units, polymer 2 will be superior in heat resistance and chemical resistance.

When copolymer 2 has DV units, copolymer 2 will be more excellent in terms of crosslinkability, and the crosslinked product of copolymer 2 will have more excellent mechanical properties (such as tensile strength and high temperature compression set).

As DV, the same compound can be mentioned as DV in the case of copolymer 1, and the same options are also preferred options.

[0039]

The content of the VdF link relative to the total number of moles of VdF links and links of the compound 1 is preferably from 86 to 96% mol., more preferably from 87 to 95% mol., also preferably from 88 to 94% mol.

In the case where copolymer 2 has units of another monomer, the content of VdF units relative to the total number of moles of VdF units, units of compound 1 and units of another monomer is preferably 52 to 93 mol%, more preferably 55 to 87 mol%, also preferably 58 to 80 mol%.

When the content of VdF units is within the range described above, the copolymer 2 will have superior mechanical properties, heat resistance, chemical resistance (alkali resistance or the like), oil resistance, and weather resistance.

[0040]

The content of the units of compound 1 relative to the total number of moles of VdF units and units of compound 1 is preferably 4 to 14 mol %, more preferably 5 to 13 mol %, also preferably 6 to 12 mol %.

The content of links of connection 1 relative to the total weight of VdF links and links of compound 1 is preferably from 10 to 50 wt. -%, more preferably from 8 to 45 wt. -%, also preferably from 5 to 40 wt.%.

In the case where copolymer 2 has units of another monomer, the content of units of compound 1 relative to the total number of moles of VdF units, units of compound 1 and units of another monomer is preferably 2 to 15 mol%, more preferably 3 to 13 mol%, also preferably 5 to 12 mol%.

In the case where copolymer 2 has units of another monomer, the content of units of compound 1 relative to the total weight of VdF units, units of compound 1 and units of another monomer is preferably from 5 to 50 wt%, more preferably from 8 to 45 wt%, also preferably from 10 to 40 wt%.

When the content of units of compound 1 in molar and mass values corresponds to at least the lower limit values of the above ranges, the copolymer 2 will have more excellent low temperature properties. When the content of compounds 1 in molar and mass values is at most the upper limit values of the above intervals, the mechanical properties and production efficiency will be excellent.

In the case where copolymer 2 has other monomer units, the content of other monomer units relative to the total moles of VdF units, compound 1 units and other monomer units is preferably 0.10 to 40 mol %, more preferably 0.15 to 36 mol %, also preferably 0.20 to 32 mol %.

In the case where the HFP units are units of another monomer as described above, the content of HFP units relative to the total number of moles of VdF units, Compound 1 units and HFP units is preferably 5 to 40 mol %, more preferably 10 to 36 mol %, also preferably 15 to 32 mol %.

When the content of HFP units is within the range described above, the copolymer 2 will have superior mechanical properties, heat resistance, chemical resistance (alkali resistance or the like), oil resistance, and weather resistance.

In the case where the DV units are units of another monomer described above, the content of DV units relative to the total number of moles of VdF units, units of Compound 1 and DV units is preferably 0.10 to 1.0 mol %, more preferably 0.15 to 0.8 mol %, also preferably 0.20 to 0.6 mol %.

When the content of DV units is at least the lower limit value of the range described above, copolymer 2 will have excellent crosslinkability, and the crosslinked product of copolymer 2 will have more excellent mechanical properties (such as tensile strength and compression set at high temperature). When the content of DV units is at most the upper limit value of the above-described range, while maintaining excellent physical properties of the crosslinked copolymer 2 product, fracture is suppressed when stress such as bending is applied at a high temperature.

[0041]

The total number of moles of VdF units and units of compound 1 relative to all units forming copolymer 2 is preferably from 50 to 100 mol%, more preferably from 60 to 100 mol%, also preferably from 70 to 100 mol%.

In the case where copolymer 2 has HFP units or DV units, the total moles of HFP units or DV units, VdF units and units of compound 1 relative to all units forming copolymer 2 is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, also preferably 70 to 100 mol%.

[0042]

Due to the presence of either one or both of iodine atoms and bromine atoms, copolymer 2 will have excellent crosslinkability. The iodine atoms or bromine atoms are preferably linked to the end of the molecular chain of copolymer 2.

The total content of iodine atoms and bromine atoms relative to the weight of the copolymer 2 is preferably from 0.01 to 5.00 wt%, more preferably from 0.03 to 2.00 wt%, also preferably from 0.05 to 1.00 wt%. When the total content of iodine atoms and bromine atoms is within the range described above, copolymer 2 will be more excellent in terms of crosslinkability and mechanical properties.

[0043]

The glass transition temperature (hereinafter, sometimes referred to as " _Tg ") of copolymer 2 is a measure of the low temperature properties of copolymer 2. Preferably, the _Tg of copolymer 2 is at most -11°C, more preferably at most -13°C, also preferably at most -18°C. When the T _{st of} the copolymer 2 is at most the upper limit of the range described above, the copolymer 2 will have more excellent low temperature properties. Preferably, the _Tg of the copolymer 2 is as low as possible, and the lower limit value is not particularly limited, and from the viewpoint of processability and mechanical properties, the _Tg of the copolymer 2 is preferably at least -58°C.

[0044]

In the case where VdF units, units of compound 1, and units of another monomer are present, the content (X2 mol %) of units of compound 1 relative to the total number of moles of units of other monomer, _Tst (Y2°C) of copolymer 2, and the glass transition temperature Y3 of the fluorinated copolymer having units constituting copolymer 2, excluding units based on compound 1 (hereinafter, sometimes referred to as "copolymer 3"), preferably satisfies the relationship (Y2-Y3)/X2≤-0.8, more preferably (Y2-Y3)/X2≤-1.0, also preferably (Y2-Y3)/X2≤-1.5.

The ratio (Y2-Y3)/X2≤-0.8, when it is satisfied, means that with the introduction of 1% mol. links of connection 1 in copolymer 3 T _st of the resulting copolymer 2 is reduced by at least 0.8°C compared with conventional FKM, that is, compound 1 is a compound effective to reduce the T _{st of} copolymer 2 by at least 0.8°C when it is introduced in an amount of 1% mol. As such compound 1, C7-PEVE, EEAVE or PHVE may be mentioned.

[0045]

The shear modulus G' of copolymer 2 is preferably 10 to 800 kPa, more preferably 25 to 550 kPa, also preferably 30 to 450 kPa. A higher shear modulus G' means a higher polymer molecular weight and a higher molecular chain weave density. When the shear modulus G' of the copolymer 2 is within the range described above, the processability and mechanical properties will be much better.

[0046]

Method for the production of a fluorinated copolymer

The fluorinated copolymer of the present invention can be produced, for example, by a method in which at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom and a chain transfer agent containing either one or both of an iodine atom and a bromine atom is provided in the polymerization system when the monomeric component is polymerized.

The monomer component contains, in the case where copolymer 1 is to be produced, TFE, propylene and compound 1, and in the case where copolymer 2 is to be produced, VdF and compound 1.

[0047]

It is possible to introduce either one or both of iodine and bromine atoms into the fluorinated copolymer in accordance with a method that ensures the presence of at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom, and a chain transfer agent containing either one or both of an iodine atom and a bromine atom, in the polymerization system when polymerizing the monomeric component.

[0048]

As the monomer containing either one or both of an iodine atom and a bromine atom, the same monomer as mentioned in the discussion of copolymer 1 may be mentioned.

[0049]

As the chain transfer agent containing either or both of an iodine atom and a bromine atom, there may be mentioned, for example, the compound represented by formula 8 (hereinafter referred to as "compound 8"), the compound represented by formula 9 (hereinafter referred to as "compound 9"), and the compound represented by formula 10 (hereinafter referred to as "compound 10"):

R ^f4 I ₂ Formula 8

R ^f5 IBr Formula 9

R ^f6 Br ₂ Formula 10

where the substituents R ^f4 , R ^f5 and R ^f6 represent a C _1-16 -fluoro-alkylene group or a structure having an aromatic ring.

The fluoroalkylene group as R ^f4 , R ^f5 and R ^f6 substituents may be linear or branched. The R ^f4 , R ^f5 and R ^f6 substituents are preferably a perfluoroalkylene group.

As compound 8, for example, 1,2-diiodoperfluoroethane, 1,3-diiodoperfluoropropane, 1,4-diiodoperfluorobutane (hereinafter referred to as "C4DI"), 1,5-diiodoperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,3-diiodo-2-chloro-perfluoropropane, 1, 5-diiodo-2,4-dichloroperfluoropentane, 1,12-diiodo-perfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2-diiodoethane, 1,3-diiodo-n-propane and (2-iodoethyl) substituted benzene, and C4DI is preferred.

As compound 9, for example, 1-iodo-4-bromoperfluorobutane, 1-iodo-6-bromoperfluorohexane, 1-iodo-8-bromoperfluorooctane, 1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluorobutene-1, 2-bromo-4-iodoperfluorobutene-1, (monioiodine-monobromo)substituted benzene and (diiodo-monobromo)substituted benzene.

As compound 10, for example, CF ₂ Br ₂ , BrCF ₂ CF ₂ Br, CF ₃ CFBrCF ₂ Br, CFClBr ₂ , BrCF ₂ CFClBr, CFBrClCFClBr, BrCF ₂ CF ₂ CF ₂ Br, BrCF ₂ CFBrOCF ₃ and (2-bromoethyl)-substituted benzene can be mentioned.

As the chain transfer agent containing either one or both of an iodine atom and a bromine atom other than compounds 8, 9 and 10, there may be mentioned a compound having only any one of an iodine atom and a bromine atom, such as 2-iodoperfluoropropane.

[0050]

The total amount of monomer containing either one or both of an iodine atom and a bromine atom and a chain transfer agent containing either one or both of an iodine atom and a bromine atom is adjusted accordingly so that the total content of iodine atoms and bromine atoms relative to the weight of copolymer 1 and copolymer 2 is within the range described above.

[0051]

In a process for producing a fluorinated copolymer, it is preferable to start the polymerization in the presence of a radical polymerization initiator. As the radical polymerization initiator, a water-soluble initiator or a redox initiator is preferred.

As the water-soluble initiator, for example, persulfate (such as ammonium persulfate, sodium persulfate or potassium persulfate) and an organic initiator (such as disuccinyl peroxide or azobisisobutylamidine dihydrochloride) can be mentioned.

[0052]

As the redox initiator, for example, a combination of a reducing agent and the above persulfate can be mentioned.

The reducing agent may be, for example, thiosulfate, sulfite, bisulfite, pyrosulfite or hydroxymethanesulfinate.

The redox initiator preferably contains, in addition to the reducing agent and persulfate, as a third component, a small amount of iron, an iron salt such as a ferrous salt, or a silver salt such as silver sulfate. Of the iron salts, a water-soluble iron salt (eg, ferrous sulfate) is preferred.

It is preferable to use a chelating agent in addition to the redox initiator. The chelating agent can be, for example, disodium ethylenediaminetetraacetate dihydrate.

The amount of the radical polymerization initiator is preferably 0.0001 to 3 parts by mass, more preferably 0.001 to 1 mass. per 100 wt.h. monomer component.

[0053]

As the polymerization method, for example, an emulsion polymerization method, a solution polymerization method, a suspension polymerization method, or a bulk polymerization method can be mentioned, and because the molecular weight and composition of the copolymer are easily controlled, and in view of the excellent production efficiency, an emulsion polymerization method in which a monomeric component is polymerized in an aqueous medium in the presence of an emulsifier is preferable.

[0054]

As the aqueous medium, water or water containing a water-soluble organic solvent is preferable, and water containing a water-soluble organic solvent is more preferable.

The water-soluble organic solvent may be, for example, tert-butyl alcohol, propylene glycol, dipropylene glycol, dipropylene glycol monomethyl ether or tripropylene glycol.

[0055]

The pH value of the aqueous medium is preferably in the range of 7 to 14, more preferably 7 to 11, also preferably 7.5 to 11, particularly preferably 8 to 10.5.

To adjust the pH, it is preferable to use a pH buffer. The pH buffer can be, for example, a phosphate (such as disodium hydrogen phosphate or sodium dihydrogen phosphate) or a carbonate (sodium bicarbonate or sodium carbonate).

[0056]

The emulsifier may be, for example, an anionic emulsifier, a nonionic emulsifier or a cationic emulsifier, and in view of the excellent mechanical and chemical stability of the latex, an anionic emulsifier or a cationic emulsifier is more preferable, and an anionic emulsifier is more preferable.

The anionic emulsifier may be, for example, a hydrocarbon emulsifier (such as sodium lauryl sulfate or sodium dodecylbenzenesulfonate), a fluorinated alkanoate (such as ammonium perfluorooctanoate or ammonium perfluorohexanoate), or a carboxylic acid fluorinated ether compound.

The emulsifier is preferably an emulsifier having a fluorine atom, more preferably a fluorinated alkanoate or a carboxylic acid fluorinated ester compound, also preferably a carboxylic acid fluorinated ester compound.

[0057]

The carboxylic acid fluorinated ester compound can be, for example, the compound represented by formula 11 (hereinafter referred to as "compound 11"):

R ^f6 OR ^f7 COOA Formula 11,

where the R ^f6 substituent is a C _1-8 perfluoroalkyl group, the R ^f7 substituent is a fluoroalkylene group or a fluoroalkylene group having one or more etheric oxygen atoms, A is a hydrogen atom, an atom classified among alkali metals, or NH ₄ . The R ^f7 substituent may have a branched C _1-3 perfluoroalkyl group. The number of carbon atoms in R ^f7 is preferably 1 to 12, more preferably 1 to 8.

[0058]

The carboxylic acid fluorinated ester compound preferably means the compound represented by formula 12 (hereinafter referred to as "compound 12"):

F(CF ₂ ) _p O(CF(X ¹ )CF ₂ O) _q CF(X ¹ )COOA Formula 12,

where X ¹ is a fluorine atom or a C _1-3 perfluoroalkyl group, A is a hydrogen atom, an atom classified among alkali metals, or NH ₄ , p is an integer from 1 to 10, and q is an integer from 0 to 3.

[0059]

As compound 11 or compound 12, for example, the following compounds can be mentioned:

C ₃ F ₇ OCF ₂ C(O)ONH ₄ ,

C ₄ F ₉ OCF ₂ C(O)ONH ₄ ,

C ₅ F ₁₁ OCF ₂ C(O)ONH ₄ ,

CF ₃ OCF ₂ CF ₂ OCF ₂ C(O)ONH ₄ ,

C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ C(O)ONH ₄ ,

C ₂ F ₅ OCF(CF ₃ )C(O)ONH ₄ ,

C ₃ F ₇ OCF(CF ₃ )C(O)ONH ₄ ,

C ₄ F ₉ OCF(CF ₃ )C(O)ONH ₄ ,

CF ₃ OCF(CF ₃ )CF ₂ OCF(CF ₃ )C(O)ONH ₄ ,

C ₃ F ₇ OCF(CF ₃ )CF ₂ OCF(CF ₃ )C(O)ONH ₄ ,

CF ₃ O(CF ₂ ) ₃ OCFHCF ₂ C(O)ONH ₄ ,

CF ₃ O(CF ₂ ) ₃ OCF ₂ C(O)ONH ₄ ,

CF ₃ O(CF ₂ ) ₃ O(CF ₂ ) ₂ C(O)ONH ₄ ,

C ₂ F ₅ O(CF ₂ ) ₂ O(CF ₂ ) ₂ C(O)ONH ₄ ,

CF ₃ O(CF ₂ ) ₃ OCF(CF ₃ )C(O)ONH ₄ ,

C ₂ F ₅ O(CF ₂ ) ₂ OCF(CF ₃ )C(O)ONH ₄ and

CF ₃ OCF ₂ OCF ₂ OCF ₂ C(O)ONH ₄ .

The amount of emulsifier relative to 100 mass.h. the aqueous medium is preferably from 0.01 to 15 wt.h., more preferably from 0.1 to 10 wt.h., also preferably from 0.1 to 3 wt.h.

[0060]

The emulsion polymerization method produces a latex containing a fluorinated copolymer. The fluorinated copolymer is aggregated and then separated from the latex.

The aggregating method may be, for example, a salting out method by adding a metal salt, a method of adding an inorganic acid such as hydrochloric acid, a mechanical shearing method, or a freezing or thawing method.

[0061]

The polymerization temperature is preferably 10 to 70°C, more preferably 12 to 60°C, also preferably 15 to 50°C. When the polymerization temperature is at least the lower limit value of the range described above, the polymerization ability will be high and the production efficiency will be excellent in terms of the polymerization speed. When the polymerization temperature is at most the upper limit of the above-described range, iodine atoms or bromine atoms will be sufficiently introduced into the fluorinated copolymer, and the fluorinated copolymer will be much better in terms of crosslinkability. In addition, the molecular weight of the fluorinated copolymer will be sufficiently high, the shear modulus G' will be sufficiently high, and the fluorinated copolymer will have better processability.

[0062]

The polymerization pressure is preferably at most 3.0 MPa(g), more preferably 0.3 to 2.8 MPa(g), also preferably 0.5 to 2.5 MPa(g). When the polymerization pressure is at least the lower limit of the range described above, the molecular weight of the fluorinated copolymer will be sufficiently high, the shear modulus G' will be sufficiently high, and the fluorinated copolymer will have better processability. When the polymerization pressure is at the most the upper limit value of the above-described range, the compound 1 will be sufficiently introduced into the fluorinated copolymer, and the fluorinated copolymer will have more excellent low temperature properties.

[0063]

The polymerization rate is preferably 1 to 500 g/l*h, more preferably 2 to 300 g/l*h, also preferably 3 to 200 g/l*h. When the polymerization rate is at least the lower limit value of the range described above, the production efficiency is particularly high. When the polymerization rate is at most the upper limit of the range described above, the fluorinated copolymer is generally unlikely to have a low molecular weight and will be more excellent in terms of crosslinkability.

The polymerization time is preferably 0.5 to 50 hours, more preferably 1 to 30 hours, also preferably 2 to 20 hours.

[0064]

Mechanism of action

The above-described fluorinated copolymer of the present invention has excellent low temperature properties since it contains Compound 1 units, and has excellent crosslinkability since it contains either one or both of iodine atoms and bromine atoms.

When a chain transfer agent having an iodine atom is used during the polymerization of the monomers constituting the fluorinated copolymer described in Patent Document 1, the compound CH ₂ =CHO(CH ₂ ) _m (CF ₂ ) _n F is hardly copolymerized, resulting in the resulting fluorinated copolymer generally having insufficient low temperature properties. On the other hand, in the process for producing a fluorinated copolymer of the present invention, compound 1 is used instead of compound CH ₂ =CHO(CH ₂ ) _m (CF ₂ ) _n F. Accordingly, even when using, for example, a chain transfer agent having an iodine atom, compound 1 is easily copolymerized during polymerization of the monomer component, and the resulting fluorinated copolymer will have excellent low temperature properties.

[0065]

Application

The fluorinated copolymer of the present invention is used for the purpose of improving mechanical properties, etc., usually as a crosslinked product obtained by mixing a crosslinking agent, an auxiliary crosslinker, etc. with a fluorinated copolymer and crosslinking the resulting composition.

The composition is obtained by mixing a crosslinking agent, an auxiliary crosslinker, other additives, etc., followed by kneading. For kneading, kneading equipment such as rollers, a kneader, a Banbury mixer or an extruder may be used.

[0066]

As the crosslinking agent, for example, organic peroxide can be mentioned.

The organic peroxide may be, for example, a dialkyl peroxide (such as di-tert-butyl peroxide, tert-butyl-cumyl peroxide, dicumyl peroxide, α,α-bis(tert-butylperoxy)-p-diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane or 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane- 3), 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroxyperoxide, benzoyl peroxide, t-butylperoxybenzene, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxy-maleic acid or t-butylperoxyisopropyl carbonate. Preferably the organic peroxide is a dialkyl peroxide.

The content of organic peroxide relative to 100 mass.h. fluorinated copolymer is preferably from 0.3 to 10 mass, more preferably from 0.3 to 5 mass, also preferably from 0.5 to 3 mass. When the organic peroxide content is within the range described above, the crosslinking rate will be appropriate and the resulting crosslinked product will have an excellent ratio between tensile strength and elongation.

[0067]

The auxiliary crosslinker may be, for example, triallyl cyanurate, triallyl isocyanurate, trimethacryl isocyanurate, 1,3,5-triacryloylhexahydro-1,3,5-triazine, triallyl trimellitate, m-phenylenediamine bismaleimide, p-quinone dioxime, p, p'-dibenzoylquinone dioxime, dipropargyl tereft alate, diallyl phthalate, N, N’,N”,N”’-tetraallyl terephthalamide, vinyl group-containing siloxane oligomer (polymethylvinylsiloxane or polymethylphenylvinylsiloxane). The auxiliary crosslinker is preferably triallyl cyanurate, triallyl isocyanurate or trimethacryl isocyanurate, more preferably triallyl isocyanurate.

The content of the auxiliary cross-linking additive relative to 100 wt.h. fluorinated copolymer is preferably from 0.1 to 20 wt.h., more preferably from 1 to 10 wt.h. When the amount of the auxiliary crosslinker is within the range described above, the crosslinking rate will be appropriate and the resulting crosslinked product will have an excellent ratio between tensile strength and elongation.

[0068]

A metal oxide may be mixed with the composition. The metal oxide is preferably a divalent metal oxide. The divalent metal oxide is preferably magnesium oxide, calcium oxide, zinc oxide or lead oxide.

The content of metal oxide relative to 100 mass.h. fluorinated copolymer is preferably from 0.1 to 10 wt.h., more preferably from 0.5 to 5 wt.h. By blending the metal oxide with the composition, the fluorinated copolymer will have a further improved crosslinkability.

[0069]

As other additives, for example, a filler, an acid scavenger, a stabilizer, a coloring agent, an antioxidant, a processing aid, a lubricant, a lubricant, a fire retardant, an antistatic agent, a pigment, a reinforcing agent, or a vulcanization accelerator can be mentioned.

Such other additives may be used alone or in combination of two or more.

[0070]

A polymeric material other than the fluorinated copolymer may be mixed with the composition, depending on the purpose. The other polymeric material may be, for example, a fluororubber (such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polychlorotrifluoroethylene, a bipolymer containing TFE units and ethylene units (hereinafter referred to as "E units"), a tetrafluoroethylene/(perfluoroalkyl vinyl ether) copolymer, or a tetrafluoroethylene/hexafluoropropylene copolymer, a fluorinated elastomer (such as a copolymer having VdF units and not having Compound 1 units; a copolymer having TFE units and P units and not having Compound 1 units; a copolymer having TFE units and VdF units and not having Compound 1 units; or a copolymer having TFE units and PAVE units and not having Compound 1 units), or a hydrocarbon elastomer (such as a copolymer having E units, P units, and non-conjugated diene units.) By mixing the fluororubber with the composition, the moldability and mechanical properties will be further improved. By mixing the hydrocarbon elastomer with the composition, the crosslinkability will be further improved.

[0071]

The composition may be crosslinked simultaneously with molding by, for example, hot pressing, or it may be preformed and then crosslinked.

The forming method may be, for example, direct compression, injection molding, extrusion, calendering, dip coating or coating.

Various conditions such as hot press stitching, steam stitching, hot air stitching, and lead stitching can be used as the stitching conditions in consideration of the molding method and shape of the crosslinked product. The crosslinking temperature may be, for example, from 100 to 400°C. The crosslinking time can be, for example, from a few seconds to 24 hours.

In order to improve the mechanical properties and compression set of the crosslinked product and to stabilize other properties, secondary crosslinking can be carried out. The temperature of the secondary crosslinking may be, for example, from 100 to 300°C. The secondary crosslinking time may be, for example, from 30 minutes to 48 hours.

[0072]

The resulting composition can be crosslinked by irradiation with radioactive rays. The radioactive rays may be, for example, electron beams or ultraviolet rays. The amount of radiation in the electron beam is preferably 0.1 to 30 Mrad, more preferably 1 to 20 Mrad.

Examples

[0073]

Hereinafter, the present invention is described in more detail with reference to examples. However, it should be understood that the present invention is not limited to these specific examples.

Examples 1-8 are examples of the present invention, and examples 9-12 are comparative examples.

[0074]

Copolymer composition

The content of units constituting the fluorinated copolymer is determined by ¹⁹ F-NMR analysis and ¹³ C-NMR analysis.

[0075]

Content of iodine atoms

A 5 cm square sheet having a thickness of 0.45 mm is prepared from the fluorinated copolymer by pressing at 100°C. The resulting sheet is measured by X-ray fluorescence analysis (XRF) with a measuring surface diameter of 30 mm. In addition, the KI reference solution is subjected to a thin film polarization fluorescence (FP) quantitative analysis, the iodine concentration is calibrated from the resulting analytical curve, and the content (wt %) of iodine atoms in the fluorinated polymer is determined. The detection limit is 0.1.

[0076]

Glass transition temperature (T _st )

The _{Tg of} the fluorinated copolymer was determined by raising the temperature at a temperature rise rate of 10° C./min using a thermal analyzer (manufactured by Seiko Instruments Inc., DSC).

[0077]

Shear modulus G'

In accordance with ASTM D6204, using a rubber process analyzer (Rubber Process Analyzer, manufactured by ALPHA TECHNOLOGIES, RPA2000), the torque is measured by changing the frequency from 1 per minute to 2000 per minute under the condition of a sample amount of 8 g, a temperature of 100°C and an amplitude of 0.5°, and the torque at a frequency of 50 per minute is taken as the shear modulus G' of the fluorinated copolymer .

[0078]

Abbreviations

C4DI: 1,4-diiodoperfluorobutane

DVE-3: CF ₂ =CFO(CF ₂ ) ₃ OCF=CF ₂

EEA: CF ₃ CF ₂ OCF ₂ CF ₂ OCF ₂ COONH ₄

Rongalite (Rongalite): 2.5% (wt.) aqueous solution of sodium hydroxymethanesulfinate dihydrate, adjusted to pH 10.0 with sodium hydroxide.

[0079]

As monomers for improving the low temperature properties of the fluorinated copolymer (hereinafter referred to as "LT monomer (LT monomer")), the following compounds are used:

C7-PEVE: CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃

EEAVE: CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃

PHVE: CF ₂ =CFOCF ₂ CF(CF ₃ )OCF ₂ CF ₂ CF ₃

FAVE-6: CH ₂ = CHOCH ₂ CH ₂ (CF ₂ ) ₆ F.

[0080]

Example 1

A high-pressure stainless steel reactor having an internal capacity of 3200 ml, equipped with a stirring anchor blade, was evacuated of air and 1450 g of deionized water, 60 g of disodium hydrogen phosphate dodecahydrate, 0.9 g of sodium hydroxide, 198 g of tert-butyl alcohol, 81 g of a 30% (wt.) aqueous solution of EEA and 7.5 g of am persulfate were added to the reactor. Monia. In addition, an aqueous solution containing 0.4 g of disodium ethylenediaminetetraacetate dihydrate and 0.3 g of ferrous sulfate heptahydrate dissolved in 200 g of deionized water and 387 g of C7-PEVE was added to the reactor. At this point, the pH of the aqueous medium in the reactor is 9.0.

Then, at 25°C, a gas mixture of monomers with a molar ratio of TFE:P=88:12 is injected so that the pressure in the reactor is 2.17 MPa(g). The anchor blade is rotated at 300 rpm and 4.0 g C4DI is added. Rongalite is then added to the reactor to initiate the polymerization reaction. After initiating the polymerization reaction, Rongalite is also added to the reactor using a high pressure pump.

After initiating the polymerization reaction, a gas mixture of monomers with a TFE:P molar ratio of 56:44 is injected, and at the moment when the injected amount reaches 420 g, the addition of rongalite is completed. When the total amount of injected gas mixture of TFE:P monomers reaches 450 g, the internal temperature of the reactor is lowered to 10° C. to complete the polymerization reaction, a latex is obtained. From the initiation of polymerization to the end of polymerization, the amount of rongalite added is 133 g. The polymerization time is 4.5 hours.

A 5% (w/w) calcium chloride aqueous solution was added to the resulting latex to aggregate the latex and precipitate the fluorinated copolymer of Example 1. The fluorinated copolymer of Example 1 was filtered off, washed with deionized water, and dried in an oven at 100°C for 15 hours to obtain 702 g of a white fluorinated copolymer of Example 1. The results are shown in Table 1.

[0081]

Example 2

A high-pressure stainless steel reactor having an internal capacity of 3200 ml, equipped with a stirring anchor blade, was evacuated of air, and 1330 g of deionized water, 60 g of disodium hydrogen phosphate dodecahydrate, 0.9 g of sodium hydroxide, 198 g of tert-butyl alcohol, 242 g of a 30% (wt.) aqueous solution of EEA and 7.5 g of persulfate were added to the reactor. ammonium. In addition, an aqueous solution containing 0.4 g of disodium ethylenediaminetetraacetate dihydrate and 0.3 g of ferrous sulfate heptahydrate dissolved in 200 g of deionized water and 152 g of C7-PEVE was added to the reactor.

Then, at 25°C, a gas mixture of monomers with a molar ratio of TFE:P=88:12 is injected so that the pressure in the reactor is 1.00 MPa(g). The anchor blade is rotated at 300 rpm and 2.6 g C4DI and 6.75 g DVE-3 are added. Rongalite is then added to the reactor to initiate the polymerization reaction. After initiating the polymerization reaction, Rongalite is also continuously added to the reactor using a high pressure pump.

After initiation of the polymerization reaction, a gas mixture of monomers with a molar ratio of TFE:P=56:44 is injected, and at the moment when the injected amount reaches 200 g, the addition of rongalite is completed. When the total amount of monomer gas mixture injected reaches 230 g, the internal temperature of the reactor is lowered to 10° C. to stop the polymerization reaction, and a latex is obtained. From the initiation of polymerization to the end of polymerization, the amount of rongalite added is 151 g. The polymerization time is 4 hours.

A 5% (w/w) calcium chloride aqueous solution was added to the resulting latex to aggregate the latex and precipitate the fluorinated copolymer of Example 2. The fluorinated copolymer of Example 2 was filtered off, washed with deionized water, and dried in an oven at 100°C for 15 hours to obtain 339 g of a white fluorinated copolymer of Example 2. The results are shown in Table 1.

[0082]

Examples 3, 4, 6, 7

The fluorinated copolymer is prepared in the same manner as in Example 1, except that the type of HT monomer, the loaded amount of materials, and the polymerization conditions are changed as defined in Table 1 or 2. The results are shown in Table 1 or 2.

[0083]

Examples 5, 8

The fluorinated copolymer was prepared in the same manner as in Example 2, except that the type of HT monomer, the loaded amount of materials, and the polymerization conditions were changed as defined in Table 2. The results are shown in Table 2.

[0084]

Example 9

The fluorinated copolymer is prepared in the same manner as in Example 1, except that no HT monomer is added and that the materials loaded and the polymerization conditions are changed as defined in Table 3. The results are shown in Table 3.

[0085]

Example 10

The fluorinated copolymer is produced by the method disclosed in Example 1 of Patent Document 1. The results are shown in Table 3.

[0086]

Example 11

The fluorinated copolymer was prepared in the same manner as in Example 1, except that no C4DI was added and that the HT monomer type, materials loaded, and polymerization conditions were changed as defined in Table 3. The results are shown in Table 3.

[0087]

Example 12

The fluorinated copolymer was prepared in the same manner as in Example 1, except that the type of HT monomer, the loaded amount of materials, and the polymerization conditions were changed as defined in Table 3. The results are shown in Table 3.

[0088]

Table 1

Example 1 Example 2 Example 3 Example 4 Type of HT monomer C7-PEVE C7-PEVE EEAVE EEAVE Quantity of supplied gas mixture of monomers (g) 450 230 450 230 Amount of added HT monomer (g) 387 152 258 132 Amount of added C4DI (g) 4.0 2.6 3.2 2.1 Amount of DVE-3 added (g) 0 6.75 0 0 The amount of added 30% (wt.) aqueous solution of EEA (g) 81 242 81 81 Curing pressure (MPa [g]) 2.17 1.00 2.17 2.17 Curing temperature (°C) 25 25 25 40 Yield (g) 702 339 588 317 Addition of a chain transfer agent having iodine atoms Added Added Added Added Copolymer Composition (mol %) * ¹ TFE links 54 51 54 53 P links 43 41 44 43 Units of HT-monomer 2 8 2 4 HT monomer units (wt %) * ² 15 33 eleven 20 DVE-3 Units (mol %) * ¹ 0 0.6 0 0 Iodine atoms (% mass) * ³ 0.3 0.4 0.3 0.4 T _st (°C) -10 -20 -5 -eleven Y1/X1 -5 -2.5 -2.5 -2.8 Shear modulus G’ (kPa) 420 136 288 32

* ¹ : Content relative to total moles of TFE units, P units and HT monomer units.

* ² : Content relative to total weight of TFE units, P units and HT monomer units.

* ³ : Content relative to the weight of the fluorinated copolymer.

[0089]

table 2

Example 5 Example 6 Example 7 Example 8 Type of HT monomer EEAVE PHVE PHVE PHVE Quantity of supplied gas mixture of monomers (g) 230 360 230 230 Amount of added HT monomer (g) 164 249 159 159 Amount of added C4DI (g) 2.6 1.6 1.0 2.6 Amount of DVE-3 added (g) 6.75 0 0 6.75 The amount of added 30% (wt.) aqueous solution of EEA (g) 242 81 161 242 Curing pressure (MPa [g]) 1.00 1.5 1.00 1.00 Curing temperature (°C) 25 25 25 25 Yield (g) 342 519 361 325 Addition of a chain transfer agent having iodine atoms Added Added Added Added Copolymer Composition (mol %) * ¹ TFE links 56 50 51 50 P links 37 44 41 42 Units of HT-monomer 7 6 8 8 HT monomer units (wt. %) * ² 31 28 34 34 DVE-3 units (mol %) * ¹ 0.6 0 0 0.6 Iodine atoms (% mass) * ³ 0.4 0.2 0.1 0.3 T _st (°C) -14 -6 -8 -7 Y1/X1 -2 -1 -1 -0.9 Shear modulus G’ (kPa) 147 108 45 129

* ¹ : Content relative to total moles of TFE units, P units and HT monomer units.

* ² : Content relative to total weight of TFE units, P units and HT monomer units.

* ³ : Content relative to the weight of the fluorinated copolymer.

[0090]

Example 3

Example 9 Example 10 Example 11 Example 12 Type of HT monomer No FAVE-6 FAVE-6 FAVE-6 Quantity of supplied gas mixture of monomers (g) 450 0 360 230 Amount of added HT monomer (g) 0 As in Example 1 of Patent Document 1 72 225 Amount of added C4DI (g) 4.0 0 3.2 Amount of DVE-3 added (g) 0 0 0 The amount of added 30% (wt.) aqueous solution of EEA (g) 40 81 81 Curing pressure (MPa [g]) 2.47 2.17 2.17 Curing temperature (°C) 25 25 25 25 Yield (g) 412 20.6 211 442 Addition of a chain transfer agent having iodine atoms Added No No Added Copolymer Composition (mol %) * ¹ TFE links 56 53 54 52 P links 44 thirty 38 43 Units of HT-monomer 0 17 8 5 HT monomer units (wt %) * ² 0 50 31 22 DVE-3 units (mol %) * ¹ 0 0 0 0 Iodine atoms (% mass) * ³ 0.4 - - Undefined T _st (°C) 0 -10.8 0, -8 0 Y1/X1 - -0.6 0, -1 0 Shear modulus G’ (kPa) 163 182 329 339

* ¹ : Content relative to total moles of TFE units, P units and HT monomer units.

* ² : Content relative to total weight of TFE units, P units and HT monomer units.

* ³ : Content relative to the weight of the fluorinated copolymer.

[0091]

The fluorinated copolymers of Examples 1-8, which include TFE units, P units, and Compound 1 units, have excellent low temperature properties. In addition, they contain iodine atoms and therefore exhibit excellent crosslinking ability.

The fluorinated copolymer of Example 9 is a conventional FEPM bipolymer and has poor low temperature properties.

The fluorinated copolymer of Example 10 is the fluorinated copolymer disclosed in Patent Document 1 and has excellent low temperature properties, however, it does not contain an iodine atom and exhibits poor crosslinkability.

Example 11 is an example in which the polymerization method of Example 10 is changed. Observe two T _article and the product is a mixture of two types of fluorinated copolymers. After the end of polymerization, the product was not obtained in the form of a latex, the product was completely aggregated, and the latex was unstable.

Example 12 is an example in which iodine atoms were introduced into the fluorinated copolymer disclosed in Patent Document 1. The content of iodine atoms is at or below the detection limit. In addition, the degree of FAVE-6 introduced does not increase and no improvement in low temperature properties is observed.

[0092]

To 100 g of the fluorinated copolymer obtained in Example 1, 20 g of MT carbon (manufactured by CANCARB LIMITED, trade name Thermax N990), 1.2 g of a crosslinking agent (manufactured by Nouryon, trade name Perkadox 14), 5 g of an auxiliary crosslinker (manufactured by Mitsubishi Chemical Corporation, trade name TAIC) and 1 g of calcium stearate (manufactured by FU JIFILM Wako Pure Chemical Corporation) and kneaded with a two-roll mill to obtain a composition. The composition is hot pressed at 170° C. for 20 minutes to form a 100 x 100 x 1 mm sheet (primary crosslinking). In addition, the sheet is heated in an oven at 200° C. for 4 hours for secondary crosslinking, and a crosslinked product (crosslinked rubber sheet) is obtained. From the resulting crosslinked rubber sheet, three No. 4 dumbbell-shaped specimens were punched out, and the tensile strength and tensile elongation were measured. Tensile strength and tensile elongation are measured in accordance with JIS K6251 (2010) at 23°C. The results are presented in table 4.

From the fluorinated copolymers obtained in examples 3 and 5, also prepare a crosslinked product in the same manner as for the copolymer of example 1, and measure the tensile strength and tensile elongation. The results are presented in table 4.

[0093]

Table 4

Example 1 Example 3 Example 5 Tensile strength (MPa) 13 13 eleven Tensile elongation (%) 290 370 150

Industrial Applicability

[0094]

The fluorinated copolymer of the present invention can be used as a material for a composite sealing material, sealing ring, sheet, gasket, oil seal, diaphragm, V-ring or packing. In addition, as an application of the fluorinated copolymer of the present invention, for example, an oil well drilling sealing member, a heat-resistant chemical-resistant sealing material, a heat-resistant oil-resistant sealing material, a low temperature-resistant sealing material, an electrical wire topcoat material, a hose/tube material, a sealing material for a semiconductor device, a corrosion-resistant rubber coating material, and a sealing material for a urea-resistant lubricant can be mentioned.

The complete description of Japanese Patent Application No. 2018-184229, filed on September 28, 2018, including the specification, claims, and abstract, is incorporated herein by reference in its entirety.

Claims (19)

1. A fluorinated copolymer which has tetrafluoroethylene-based units, propylene-based units, and units based on at least one of CF ₂ =CFOCF 2 CF 2 OCF ₂ OCF ₂ OCF _{3 and} CF 2 =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , or which has units based on vinylidene fluoride and units based on at least one of CF ₂ =CFOCF _{2 CF 2 OCF 2 OCF 2} OCF ₃ and _{CF 2 =} CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , and which has either one or both of iodine atoms and bromine atoms. 2. The fluorinated copolymer according to claim 1, which is a fluorinated copolymer that has tetrafluoroethylene-based units, propylene-based units, and units based on at least one of CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ and CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , and which has either one or both of the atom ov iodine and bromine atoms. 3. Fluorinated copolymer according to claim 1 or 2, in which, relative to the total number of moles of units based on tetrafluoroethylene, units based on propylene and units based on at least one of CF 2 =CFOCF 2 CF ₂ OCF ₂ OCF ₂ OCF ₃ and CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , the content of units based on tetrafluoroethylene is 35 to 65 mol %, the content of _propylene -based units is 20 to 50 mol %, and the content of units based on at least one _of CF ₂ =CFOCF ₂ CF 2 OCF ₂ OCF _{2 OCF 3} and CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ is 2 to 15 mol %, and relative to the total weight of units based on tetrafluoroethylene, units based on propylene and units based on at least one of CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ and CF2=CFOCF ₂ CF ₂ OCF _{2 CF 2 OCF 2 CF 3 , content of units based on at least one of CF 2 =CFOCF 2 CF 2 OCF 2 OCF 2 OCF 3 and CF 2 = CFOCF 2 CF 2 OCF 2} CF ₂ OCF ₂ CF ₃ is from 10 to 50% of the mass. 4. Fluorinated copolymer according to any one of paragraphs. 1-3, in which the content of X1 mol%. units based on at least one of CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ and CF ₂ =CFOCF _{2 CF 2 OCF 2 CF 2 OCF 2 CF 3 relative to the total number of moles of units based on tetrafluoroethylene, units based on propylene and units based on at least one of CF 2 =CFOCF 2 CF 2 OCF 2 O CF 2 OCF 3 and} CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , and the glass transition temperature Y1°C of the fluorinated copolymer satisfies the ratio Y1 _/ X1≤ -0.8. 5. Fluorinated copolymer according to any one of paragraphs. 1-4 which further has units based on a monomer having at least two polymerizable unsaturations. 6. The fluorinated copolymer according to claim 1, which is a fluorinated copolymer that has units based on vinylidene fluoride and units based on at least one of CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ and CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , and which has either one or both of iodine atoms and atoms bromine. 7. The fluorinated copolymer according to claim 6, which additionally has units based on another monomer. 8. The fluorinated copolymer according to claim 6, in which, relative to the total number of moles of units based on vinylidene fluoride and units based on at least one of CF ₂ =CFOCF ₂ CF ₂ OCF 2 OCF _{2 OCF 3} and CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , the content of units based on vinylidene fluoride is from 86 to 96% mol., and the content of units based on at least one of CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ and CF ₂ =CFOCF ₂ CF 2 OCF ₂ CF _{2 OCF 2} CF ₃ is from 4 to 14% mol., and relative to the total mass of units based on vinylidene fluoride and units based on at least one of CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF 3 and CF _{2 =CFOCF 2 CF 2 OCF 2 CF 2 OCF 2 CF 3 , the content of units based on at least one of CF 2 =CFOCF 2 CF 2 OCF 2 OCF 2 OCF 3 and CF 2 = CFOCF 2 CF 2 OCF 2 CF 2 OCF 2 CF 3 is from 10 to 50 % of} the mass. 9. Fluorinated copolymer according to any one of paragraphs. 6-8, in which the content of X2 mol%. звеньев на основе по меньшей мере одного из CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ и CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , относительно общего числа молей звеньев на основе винилиденфторида, звеньев на основе по меньшей мере одного из CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ и CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ и звеньев на основе другого мономера, если он присутствует, температура стеклования Y2°C фторированного сополимера и температура стеклования Y3°C фторированного сополимера, имеющего звенья, составляющие фторированный сополимер, за исключением звеньев на основе по меньшей мере одного из CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ и CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , удовлетворяет соотношению (Y2-Y3)/X2≤ -0,8. 10. The fluorinated copolymer according to claim 7 or 9, wherein the other monomer is hexafluoropropylene. 11. The fluorinated copolymer according to claim 7 or 9, wherein the other monomer is a monomer having at least two polymerizable unsaturations. 12. Fluorinated copolymer according to any one of paragraphs. 1-11, which has a shear modulus G' from 10 to 800 kPa. 13. Fluorinated copolymer according to any one of paragraphs. 1-12, in which the total content of iodine atoms and bromine atoms relative to the weight of the fluorinated copolymer is from 0.01 to 5.00% of the mass. 14. A method for producing a fluorinated copolymer, which includes polymerizing a monomer component containing tetrafluoroethylene, propylene and at least one compound from CF ₂ =CFOCF ₂ CF 2 OCF 2 OCF ₂ OCF ₃ and CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ or a monomer component containing vinylidene fluoride and at least _one compound from CF ₂ = CFOCF ₂ CF _{2 OCF 2} OCF ₂ OCF ₃ and CF ₂ = CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , where at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom, and a chain transfer agent containing either one or both of an iodine atom and a bromine atom must be present in the polymerization system. 15. The method for producing a fluorinated copolymer according to claim 14, which includes polymerizing a monomeric component containing vinylidene fluoride, at least one compound from CF ₂ =CFOCF ₂ CF ₂ OCF ₂ OCF ₂ OCF ₃ and CF ₂ =CFOCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ , and another monomer, where at least one component selected from the group consisting of a monomer containing either one or both of an iodine atom and a bromine atom, and a chain transfer agent containing either one or both of an iodine atom and a bromine atom must be present in the polymerization system.