RU2398796C2 - Fluorinated elastomer latex, method of producing said latex, flourinated elastomer and product moulded from fluororubber - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention discloses fluorinated elastomer latex which contains an aqueous medium, a fluorinated elastomer dispersed in the aqueous medium in amount of 10-60 wt %, and a fluorinated emulsifying agent of formula (1): C₂F₅OCF₂CF₂OCF₂COOA, where A is a hydrogen atom, an alkali metal or NH₄ which has excellent dispersion stability. Disclosed is a fluorinated elastomer obtained through coagulation of fluorinated elastomer latex, which has low content of emulsifying agent, as well as a product moulded from fluororubber obtained by cross-linking the fluorinated elastomer and which has excellent physical properties.

EFFECT: improved environmental and sanitary-technical properties of the elastomer and improved properties of the fluororubber.

8 cl, 2 tbl, 7 ex

Description

The present invention relates to a fluorinated elastomeric latex stabilized by a special fluorinated emulsifier, to a method for its preparation, to a fluorinated elastomer obtained from a fluorinated elastomeric latex, and to a molded product from fluororubber.

Until now, methods of homopolymerizing a fluoromonomer or copolymerizing a fluoromonomer with another monomer in an aqueous medium using various emulsifiers have been widely used and various emulsifiers have been proposed, as described in US patent 3271341, JP-A-2002-317003, etc.

Methods for producing fluoropolymers (resins) using emulsifiers, as described in these documents, are already known, but the method for producing the so-called fluorinated elastomer, in which the polymer has a glass transition temperature as close to room temperature as possible, especially as close as possible to 10 ° C, has not yet been famous.

In addition, a perforated emulsifier widely used for emulsion polymerization for a fluoropolymer is attached to the fluoropolymer obtained in large quantities after coagulation of the fluoropolymer latex, and a method of reducing the amount to be attached would be desirable.

In addition, it is believed that the perfluorooctanoate emulsifier, widely used for emulsion polymerization, affects the environment, and it would also be desirable to use an emulsifier having a different structure.

Under these circumstances, an object of the present invention is to provide a fluorinated elastomeric latex having a very high dispersion stability of a fluorinated elastomer obtained by emulsion polymerization using a special fluorinated elastomer with a structure different from that of a perfluorooctanoate emulsifier widely used for emulsion polymerization of a fluoropolymer so that reduce the content of the emulsifier attached to the fluorinated elastomer, p radiation coagulating the fluorinated elastomer latex, and to propose fluororubber molded product having a very high physical properties and obtained by crosslinking the fluorinated elastomer.

That is, the present invention provides a fluorinated elastomeric latex containing a fluorinated emulsifier depicted by the formula (1):

C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOA,

where A is a hydrogen atom, an alkali metal or NH ₄ and m is an integer from 1 to 3,

wherein the fluorinated polymer is a polymer of at least one fluoromonomer selected from the group consisting of tetrafluoroethylene (hereinafter referred to as TFE), vinylidene fluoride (hereinafter referred to as VDF), hexafluoropropylene (hereinafter referred to as HFP), perfluoro (alkyl or alkyloxyalkyl vinyl) ether) represented by the formula CF ₂ = C (OR ^f ) _n F _2-n (where R ^f is a C _1-9 perfluoroalkyl group or a perfluoro (alkyloxyalkyl) group containing one or more ether bonds, n is 1 or 2 and each carbon I chain may be linear or contain branches or may have a cyclic structure) (hereinafter referred to as PAVE), and from chlorotrifluoroethylene (hereinafter referred to as CTFE) and, if required in a particular case, at least one hydrocarbon monomer selected from the group consisting of a vinyl ether represented by the formula CH ₂ = CHOR (wherein R is a C _1-8 alkyl group or alkyloxyalkyl group containing one or more ether bonds, and each carbon chain may be linear or have branching I or may have a cyclic structure), propylene (hereinafter referred here P) and ethylene (hereinafter referred herein Oe), and, if required in a particular case, from 0.001 to 10 mol.% of the monomer containing a crosslinkable group.

The present invention also provides the above fluorinated elastomeric latex in which the fluorinated elastomer is at least one selected from the group consisting of TFE / P copolymer, TFE / P / VDF copolymer, TFE / HFP copolymer, VDF / HFP copolymer, copolymer TFE / VdF / HFP copolymer, a TFE / CF ₂ = CFOCF ₃ copolymer, a TFE / CF ₂ = CFOC ₃ F ₇ copolymer, a TFE / CF ₂ = CFOCF ₃ / CF ₂ = CFOC ₃ F ₇ copolymer, a TFE / CF ₂ = C (OC ₂ F ₅ ) ₂ , TFE / methyl vinyl ether copolymer (hereinafter referred to as MVE hereinafter), TFE / ethyl vinyl ether copolymer (hereinafter referred to as EVE hereinafter), copolymer TFE / n-butyl vinyl ether (hereinafter referred to as BVE), TFE / EVE / BVE copolymer, VDF / CF ₂ = CFOC ₃ F ₇ copolymer, E / HFP copolymer and the like, which has a crosslinkable monomer (crosslinkable) ) a group and also copolymerizable with said monomers.

The present invention also provides the above fluorinated elastomeric latex in which the fluorinated elastomer is at least one selected from the group consisting of a TFE copolymer (from 40 to 60 mol.%) And P (from 60 to 40 mol.%), copolymer of TFE (from 20 to 79 mol.%), P (from 79 to 20 mol.%) and VDF (from 1 to 50 mol.%), copolymer of TFE (from 20 to 80 mol.%) and HFP (from 80 up to 20 mol.%), VDF copolymer (from 50 to 95 mol.%) and HFP (from 5 to 50 mol.%), TFE copolymer (from 1 to 35 mol.%), VDF (from 45 to 90 mol. %) and HFP (5 to 50 mol.%) copolymer, a TFE (from 40 to 70 mol.%) and CF ₂ = CFOCF ₃ (60 to 30 m l.%) copolymer, a TFE (from 40 to 70 mol.%) and CF ₂ = CFOC ₃ F ₇ (60 to 30 mol.%) copolymer, a TFE (from 40 to 70 mol.%) and CF ₂ = C (OC ₂ F ₅ ) ₂ (from 60 to 30 mol.%), TFE copolymer (from 70 to 30 mol.%) And MBE (from 30 to 70 mol.%), TFE copolymer (from 70 to 30 mol.% ) and EVE (from 30 to 70 mol.%), TFE copolymer (from 70 to 30 mol.%) and BVE (from 30 to 70 mol.%), TFE copolymer (from 60 to 30 mol.%), EVE ( from 1 to 69 mol.%) and BVE (from 1 to 69 mol.%), VDF copolymer (from 40 to 70 mol.%) and CF ₂ = CFOC ₃ F ₇ (from 60 to 30 mol.%), copolymer E (from 40 to 60 mol.%) And HFP (from 60 to 40 mol.%), As well as such a copolymer that has from 0.001 to 10 mol.% Of a monomer containing a stitched group and also copolymerizable with them.

The present invention also provides the aforementioned fluorinated elastomeric latex in which the fluorinated emulsifier is C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOA (where A is a hydrogen atom, an alkali metal or NH ₄ ).

The present invention also provides a method for producing a fluorinated elastomeric latex, which includes emulsion polymerization of a fluoromonomer in an aqueous medium containing from 0.001 to 10 wt.% Of a fluorinated emulsifier represented by the formula (1):

C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOA,

where A is a hydrogen atom, an alkali metal or NH ₄ and m is an integer from 1 to 3, to obtain a fluorinated elastomeric latex.

The present invention also provides the aforementioned method for producing a fluorinated elastomeric latex in which the fluoromonomer is at least one fluoromonomer selected from the group consisting of TFE, VDF, HFP, PAVE represented by the formula CF ₂ = C (OR ^f ) _n F _{2 -n} (where R ^f is a C _1-9 perfluoroalkyl group or a perfluoro (alkyloxyalkyl) group containing one or more ether bonds in its molecule, n is an integer of 1 or 2, and each carbon chain may be linear, or may contain branches, or my have a cyclic structure) and CTFE, and if required in a particular case, at least one hydrocarbon monomer selected from the group consisting of vinyl ether represented by formula CH ₂ = CHOR (wherein R is a C _1-8 alkyl group or an alkyloxyalkyl group containing one or more ether bonds, and each carbon chain may be linear or contain branches, or may have a cyclic structure), P and E, and, as required in this case, from 0.001 to 10 mol.% a monomer containing a crosslinkable group and co imerizuemogo with them.

The present invention also provides the above method for producing a fluorinated elastomeric latex in which the fluorinated emulsifier is C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOA (where A is a hydrogen atom, an alkali metal, or NH ₄ ).

The present invention also provides the above method for producing a fluorinated elastomeric latex, in which the fluoromonomer is subjected to emulsion polymerization in the presence of C _n F _m I _{2n + 2-m} (where n is an integer from 1 to 16 and m is an integer from 1 to (2n + 1)), as a regulator of the degree of polymerization.

The present invention also provides a fluorinated elastomer obtained by coagulation of the above fluorinated elastomeric latex.

The present invention also provides the aforementioned fluorinated elastomer, which has a Mooney viscosity of 5 to 200 in accordance with Japanese Standard JIS K6300, using a large rotor with a diameter of 38.1 mm and a thickness of 5.54 mm at 100 ° C. and a predetermined preheat time within one minute, and the rotor rotation time is 4 minutes.

The present invention also provides a molded product of fluororubber obtained by crosslinking the above fluorinated elastomer.

The fluorinated elastomeric latex in accordance with the present invention has excellent dispersion stability of the fluorinated elastomer. According to the method for producing the fluorinated elastomeric latex of the present invention, a fluorinated elastomer having a glass transition temperature of at most 20 ° C can be obtained, and in addition, the amount of perfluoroemulsifier attached to the fluorinated elastomer after coagulation can be reduced, and the number of washes can be reduced. however, high performance in fluorinated elastomeric latex and fluorinated elastomer can be achieved. The fluorinated elastomer of the present invention has a low content of fluorinated emulsifier represented by the formula (1), and thus excellent environmental and sanitary properties. A fluorinated rubber molded product obtained by crosslinking the fluorinated elastomer of the present invention has excellent physical properties.

The present invention will now be described in detail with reference to preferred embodiments.

The fluorinated elastomeric latex of the present invention can be obtained by emulsion polymerization of a fluoromonomer in an aqueous medium containing a fluorinated emulsifier represented by the formula (1), or can be obtained by adding a fluorinated emulsifier represented by the formula (1) to the fluorinated elastomeric latex obtained by the emulsion polymerization of fluoromone an aqueous medium containing another emulsifier, and not a fluorinated emulsifier represented by the formula (1).

The fluoromonomer subjected to emulsion polymerization may be at least one fluoromonomer selected from TFE, VDF, HFP, PAVE and CTFE. Such a fluoromonomer can be used alone or in combination with two or more fluoromonomers.

In addition, one or more copolymerizable hydrocarbon monomers selected from the group consisting of a vinyl ester represented by the formula CH ₂ = CHOR (wherein R is a C _1-8 alkyl group or an alkyloxyalkyl group containing one or more simple ether bonds, and each carbon chain may be linear or contain branches or may have a cyclic structure), P and E.

In addition, another copolymerizable monomer other than the above may be copolymerized. Such another copolymerizable monomer may be a monomer containing a crosslinkable group in an amount of from 0.001 to 10 mol%. Such a crosslinkable group may be, for example, a carbon-carbon double bond group, a halogen atom, an acid anhydride residue, a carboxyl group, an amino group, a cyano group or a hydroxyl group.

Specific examples of a monomer containing a crosslinkable group include 1-bromo-1,1,2,2-tetrafluoroethyl trifluoro-vinyl ether (hereinafter referred to as BRVE), 1-iodo-1,1,2,2-tetrafluoroethyl-trifluoro-vinyl ( ether), vinyl crotonate, vinyl methacrylate, maleic anhydride, itaconic anhydride, maleic acid, itaconic acid and heptafluoro-4-pentenonitrile. Such a monomer containing a crosslinkable group may be used alone or in combination of such two or more monomers. The proportion of such a monomer containing a crosslinkable group in the copolymer is preferably from 0.001 to 5 mol.%, Particularly preferably from 0.01 to 3 mol.%.

Specific examples of a preferred fluorinated elastomer in the resulting fluorinated elastomeric latex include a TFE and P copolymer, TFE, P and VDF copolymer, TFE and HFP copolymer, TFE and HFP copolymer, TFE, VDF and HFP copolymer, TFEF ₃ and CF ₂ copolymer = , TFE and CF ₂ = CFOC ₃ F ₇ copolymer, TFE, CF ₂ = CFOCF ₃ and CF ₂ = CFOC ₃ F ₇ copolymer, TFE and CF ₂ = C (OC ₂ F ₅ ) ₂ copolymer TFE and MVE copolymer, TFE copolymer and EVE copolymer, a TFE and BVE copolymer of TFE and EVE BVE copolymer, a VdF and CF ₂ = CFOC ₃ F ₇ copolymer, HFP and E, as well as such copolymers which have a monomer containing sshi aemuyu group and also copolymerizable with them.

Particularly preferred are a TFE and P copolymer, TFE, P and VDF copolymer, TFE and PAVE copolymer, VDF and HFP copolymer, TFE, VDF and HFP copolymer, as well as similar copolymers that have a monomer containing a crosslinkable group and also copolymerizable with them.

The molar ratio of the polymerizable units of the respective monomers in the copolymer is not specifically limited and can be appropriately selected depending on the required characteristics. For example, the molar ratio of (polymerized TFE units) / (polymerized P units) in the TFE-P copolymer is preferably from 40/60 to 70/30, more preferably from 50/50 to 60/40.

In addition, in the TFE-PAVE copolymer, the PAVE perfluoroalkyl group has from 1 to 9 carbon atoms, and it may be linear, or contain branches, or may have a cyclic structure or a mixture of both. The perfluoroalkyl group is more preferably a CF ₃ group or a C ₃ F ₇ group. In addition, a perfluoro (alkyloxyalkyl) group having one or more PAVE ether bonds has 1 to 9 carbon atoms, preferably it has four or less, more preferably two or less ether bonds, and it may be linear or contain branches, or may have a cyclic structure or a mixture of both. Such a perfluoro (alkyloxyalkyl) group is more preferably a C ₂ F ₅ OC ₂ F ₄ group, a C ₃ F ₇ OC ₃ F ₆ group, or a C ₃ F ₇ OC ₃ F ₆ OC ₃ F ₆ group.

In the TFE-PAVE copolymer, the molar ratio (polymerized TFE units) / (polymerized PAVE units) is preferably from 85/15 to 25/75, more preferably from 75/25 to 40/60.

Specific examples of a particularly preferred fluorinated elastomer include a TFE copolymer (40 to 60 mol%) and P (60 to 40 mol%), a TFE copolymer (20 to 79 mol%), P (79 to 20 mol.%) and VDF (from 1 to 50 mol.%), a TFE copolymer (from 20 to 80 mol.%) and HFP (from 80 to 20 mol.%), a VDF copolymer (from 50 to 95 mol.%) and HFP (from 5 to 50 mol.%), TFE copolymer (from 1 to 35 mol.%), VDP (from 45 to 90 mol.%) and HFP (from 5 to 50 mol.%), TFE copolymer (from 40 to 70 mol.%) And CF ₂ = CFOCF ₃ (60 to 30 mol.%), TFE copolymer (40 to 70 mol.%) And CF ₂ = CFOC ₃ F ₇ (60 to 30 mol.% ), TFE copolymer (from 40 to 70 mol.%) and CF ₂ = С (OC ₂ F ₅ ) ₂ (from 60 up to 30 mol.%), TFE copolymer (from 70 to 30 mol.%) and MVE (from 30 to 70 mol.%), TFE copolymer (from 70 to 30 mol.%) and EVE (from 30 to 70 mol. %), a copolymer of TFE (from 70 to 30 mol.%) and BVE (from 30 to 70 mol.%), a copolymer of TFE (from 60 to 30 mol.%), EVE (from 1 to 69 mol.%) and BVE (from 1 to 69 mol.%), VDF copolymer (from 40 to 70 mol.%) and CF ₂ = CFOC ₃ F ₇ (from 60 to 30 mol.%), copolymer E (from 40 to 60 mol.%) and HFP (from 60 to 40 mol.%), as well as the listed copolymers, which have a monomer containing a crosslinkable group and also copolymerizable with them, in an amount of from 0.001 to 10 mol.%.

The TFE copolymer (from 40 to 60 mol.%) And P (60 to 40 mol.%) Means the copolymer obtained by copolymerization of TFE and P in the ratio of 40-60 mol.%: 60-40 mol.%, And the same applies to other copolymers.

In addition, the copolymer of TFE (from 40 to 60 mol.%) And P (from 60 to 40 mol.%) Having a monomer containing a crosslinkable group and also copolymerizable with them in an amount of from 0.001 to 10 mol.%, Means such a copolymer in which the ratio of the two components TFE and P in the copolymer is 40-60 mol.%; 60-40 mol.%, And the proportion of the monomer containing a crosslinkable group in the copolymer is from 0.001 to 10 mol.% Of the total number of three monomer components. The same applies to other copolymers.

The fluorinated elastomer of the present invention preferably has a glass transition temperature of at most 20 ° C, more preferably at most 10 ° C, particularly preferably at most 5 ° C.

The fluorinated elastomeric latex of the present invention is characterized in that it contains one type or several types of fluorinated emulsifiers represented by the formula (1):

C ₂ F ₅ O (CF ₂ CF ₂ O) _m CF ₂ COOA,

where A is a hydrogen atom, an alkali metal or NH ₄ and m is an integer from 1 to 3.

The alkali metal in A may be, for example, lithium, sodium or potassium. Particularly preferably, A is NH ₄ or sodium, and most preferably NH ₄ .

The following can be considered examples of a fluorinated emulsifier.

In the case where A is a hydrogen atom, specific examples include C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOH, C ₂ F ₅ O (CF ₂ CF ₂ O) ₂ CF ₂ COOH and C ₂ F ₅ O (CF ₂ CF ₂ O) ₃ CF ₂ COOH.

In the case where A is lithium, specific examples include C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOLi, C ₂ F ₅ O (CF ₂ CF ₂ O) ₂ CF ₂ COOLi and C ₂ F ₅ O (CF ₂ CF ₂ O) ₃ CF ₂ COOLi.

In the case where A is sodium, specific examples include C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COONa, C ₂ F ₅ O (CF ₂ CF ₂ O) ₂ COONa and C ₂ F ₅ O (CF ₂ CF ₂ O) ₃ COONa.

In the case where A is potassium, specific examples include C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOK, C ₂ F ₅ O (CF ₂ CF ₂ O) ₂ COOC and C ₂ F ₅ O (CF ₂ CF ₂ O) ₃ COOC.

In the case where A is NH ₄ , specific examples include C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COONH ₄ , C ₂ F ₅ O (CF ₂ CF ₂ O) ₂ COONH ₄ and C ₂ F ₅ O (CF ₂ CF ₂ O) ₃ COONH ₄ .

In the present invention, the fluorinated emulsifier is preferably C ₂ F ₅ O (CF ₂ CF ₂ O) _1-2 CF ₂ COOA (where A is a hydrogen atom, an alkali metal or NH ₄ ), more preferably C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COONH ₄ or C ₂ F ₅ O (CF ₂ CF ₂ O) ₂ CF ₂ COONH ₄ , particularly preferably C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COONH ₄ .

In the method for producing the fluorinated elastomeric latex of the present invention, the fluoromonomer is subjected to emulsion polymerization in an aqueous medium containing a fluorinated emulsifier represented by the formula (1) in an amount of from 0.001 to 10 wt.%. The content of the fluorinated emulsifier represented by the formula (1) in the aqueous medium is preferably from 0.001 to 5 wt.%, Particularly preferably from 0.01 to 3 wt.%.

The aqueous medium may be, for example, water, such as deionized water, pure water or ultrapure water. The aqueous medium may contain an organic solvent soluble in water. Such an organic solvent may be, for example, preferably alcohol, ketone, ether, ethylene glycol or propylene glycol. The proportion of organic solvent is preferably from 1 to 50 wt. parts, more preferably from 3 to 20 wt. parts per 100 wt. parts of water. The amount of water, as the basis for the proportion of fluorinated emulsifier, does not include the content of other additives, for example, such as a polymerization initiator.

The fluorinated emulsifier used in the present invention, in comparison with the known emulsifiers, which does not have ethereal oxygen, such as ammonium perfluorooctanoate, and emulsifiers in which the perfluralkyl group has a branched structure, has such characteristics that its aqueous solution can have a high dynamic surface tension , compared with solutions having the same concentration, and, accordingly, it is believed that the latex containing it has low stability during polymerization. However, it turned out that the fluorinated emulsifier used in the present invention provides very high latex stability during polymerization, and the amount of fluorinated emulsifier attached to the fluorinated elastomer after coagulation of the latex tends to become negligible.

As the polymerization initiator used for emulsion polymerization, a conventional radical polymerization initiator can be used, and a water soluble polymerization initiator is particularly preferred. Specific examples of a water-soluble polymerization initiator include a persulfate such as ammonium persulfate, hydrogen peroxide, a redox polymerization initiator containing a combination of said persulfate or hydrogen peroxide with a reducing agent such as sodium sulfite or sodium thiosulfate, an inorganic polymerization initiator with a system in which a small amount of iron, a ferrous salt (such as iron (II) sulfate), silver sulfate and the like. coexist with such a redox polymerization initiator, and an organic polymerization initiator, such as disuccinyl peroxide or azobisisobutylamidine dichlorohydrate.

The polymerization initiator may be added at the beginning of the emulsion polymerization, or may be added during the emulsion polymerization. The amount of polymerization initiator added is preferably from 0.0001 to 3 wt.%, Particularly preferably from 0.001 to 1 wt.% Of the amount of monomer used for polymerization.

In the case where a redox polymerization initiator is used, it is preferable to use a pH buffer to adjust the pH of the polymerization medium within a range that does not impair the reactivity of the redox reactions. The pH buffer may be, for example, sodium hydrogen phosphate, sodium dihydrogen phosphate or sodium carbonate, and it is preferably sodium hydrogen phosphate dihydrate or sodium hydrogen phosphate dodecahydrate.

In addition, in the case where a redox polymerization initiator is used, various metals having many valencies of their ions can be used as metal ions that undergo a redox reaction. Particularly preferred is a transition metal such as iron, copper, manganese or chromium, and iron is particularly preferred.

In addition, so that the metal subjected to the redox reaction is stably present in the polymerization medium, it is preferable to use a metal chelating agent. Such a metal chelating agent is preferably ethylenediaminetetraacetic acid, more preferably disodium ethylenediaminetetraacetate dihydrate due to its solubility in water.

As a redox reaction reagent in the case where a redox polymerization initiator is used, it is preferable to use a reducing agent. As a reducing agent, a sulfur-containing compound such as sulfuric acid can be used, and rongalite is particularly preferred (chemical formula: CH ₂ (OH) SO ₂ Na · 2H ₂ O). It is desirable to continuously add the reducing agent appropriately during the polymerization and it is desirable to adjust its pH so that it is the same as the pH of the polymerization medium so that the pH of the polymerization medium does not change during the addition.

For the polymerization of the fluoromonomer, a degree of polymerization control can be used to control molecular weight.

The degree of polymerization can be controlled, for example, by alcohol, such as methanol, ethanol or propanol, chlorofluorocarbons, such as 1,3-dichloro-1,1,2,2,3-pentafluoropropane or 1,1-dichloro-1-fluoroethane, a hydrocarbon such as methane, ethane, propane, butane, pentane, hexane or cyclohexane, C _n F _m I _{2n + 2-m} (where n is an integer from 1 to 16 and m is an integer from 1 to 2p) or R ^f3 IBr (where R ^f3 is a saturated C _1-16 polyfluoroalkylene group).

C _n F _m I _{2n + 2-m} is preferably R ^f2 I ₂ (where R ^f2 is a saturated C _1-16 polyfluoroalkylene group), more preferably 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane or 1,2,4 triiodoperfluorobutane. In addition, R ^f3 IBr is preferably 1-bromo-4-iodoperfluorobutane. Such a degree of polymerization regulator can be used alone or as a combination of two or more of such regulators.

The amount of polymerization degree adjuster added is preferably from 0.001 to 10 wt.%, More preferably from 0.01 to 10 wt.% Of the amount of monomer to be polymerized.

The conditions for conducting emulsion polymerization to obtain the fluorinated elastomeric latex of the present invention are selected depending on the type of the specified fluorinated elastomer, the proportion of fluoromonomer in the copolymer, the decomposition temperature of the polymerization initiator, etc. The gauge (excess) pressure during polymerization is preferably at least 0 MPa and a maximum of 20 MPa, particularly preferably at least 0.3 MPa and a maximum of 10 MPa and extremely preferably at least 0.3 MPa and a maximum 5 MPa. The polymerization temperature is preferably at least 0 ° C and a maximum of 100 ° C, particularly preferably at least 10 ° C and a maximum of 80 ° C.

The fluorinated elastomeric latex of the present invention can be obtained, as mentioned above, by emulsion polymerization in the presence of a fluorinated emulsifier represented by the formula (1).

In addition, the fluorinated elastomeric latex of the present invention is also preferably obtained by emulsion polymerization of a fluoromonomer in an aqueous medium containing a different emulsifier, rather than a fluorinated emulsifier represented by the formula (1), for example, a fluorinated emulsifier such as ammonium perfluorooctanoate, perfluorooctanoic acid, perfluorooctanoate, perfluorooctanoate, sodium perfluorooctanoate, potassium perfluorooctanoate, C _p F _{2p + 1} O (CF ₂ CF ₂ O) _q CF ₂ COOA (where A is a hydrogen atom, an alkali metal or NH ₄ , p is an integer from 3 to 10 and q is 0 or an integer from 1 to 3), or R ^f4 - (OCH ₂ CF ₂ CF ₂ ) _r -O-CH _S F _s-2 CF ₂ -R ^f5 -СООА (where R ^f4 is linear or branched С _{1 A -20} fluoroalkyl group or a fluoroalkyloxyalkyl group, r is 0 or an integer from 2 to 3, s is 0, 1 or 2, R ^f5 is a C _1-25 fluoroalkylene group and A is a hydrogen atom, an alkali metal or NH ₄ ) or a hydrocarbon emulsifier, such as sodium dodecylbenzenesulfonate or sodium laurinsulfate, to produce a fluorinated elastomeric latex to which a fluorinated emulsifier is added, representing ny formula (1) to replace the above emulsifier. In the above production method, the content of an emulsifier different from the fluorinated emulsifier represented by formula (1) in an aqueous medium is preferably from 0.03 to 10 wt.%, More preferably from 0.05 to 5 wt.% Of the amount of fluoropolymer.

Among the above preparation methods, an emulsion polymerization method in the presence of a fluorinated emulsifier represented by the formula (1) is particularly preferred.

In the fluorinated elastomeric latex of the present invention, the particle size of the fluorinated elastomer dispersed in an aqueous medium is preferably from 0.01 to 10 μm, more preferably from 0.01 to 5 μm, most preferably from 0.05 to 3 μm. The dispersion stability of the fluorinated elastomer in this range will be excellent.

In the fluorinated elastomeric latex, the content of the fluorinated elastomer is preferably from 10 to 60 wt.%, More preferably from 15 to 60 wt.%, Particularly preferably from 15 to 50 wt.%.

In addition, in the fluorinated polymer latex, the content of the fluorinated emulsifier represented by the formula (1) is preferably from 0.03 to 10 wt.%, More preferably from 0.05 to 5 wt.% By weight of the fluoropolymer. In addition, the content of such a fluorinated emulsifier based on the weight of the aqueous medium is preferably from 0.001 to 5 wt.%, More preferably from 0.01 to 3 wt.%.

That is, the fluorinated polymer latex of the present invention preferably contains an aqueous medium, a fluorinated elastomer dispersed in an aqueous medium in an amount of from 10 to 60 wt.% And a fluorinated emulsifier represented by the formula (1) in an amount of from 0.03 to 10 wt. % of the amount of fluoropolymer. In addition, it more preferably contains an aqueous medium, a fluorinated elastomer dispersed in an aqueous medium in an amount of from 15 to 60 wt.% And a fluorinated emulsifier represented by the formula (1) in an amount of from 0.05 to 5 wt.% Of the amount fluoropolymer. In addition, it most preferably contains an aqueous medium, a fluorinated elastomer dispersed in an aqueous medium in an amount of from 15 to 50 wt.%, And a fluorinated emulsifier represented by the formula (1), in an amount of from 0.05 to 5 wt.% From the amount of fluoropolymer.

A coagulant may be added to the fluorinated elastomeric latex obtained by the emulsion polymerization method to coagulate the fluorinated elastomer.

Any coagulant that is commonly used to coagulate fluoropolymer latex can be used as a coagulant, and it can be, for example, a water-soluble salt such as calcium chloride, magnesium chloride, aluminum chloride or aluminum nitrate, an acid such as nitric acid, hydrochloric acid or sulfuric acid, or a water-soluble organic liquid, such as alcohol or acetone. The amount of added coagulant is preferably from 0.001 to 20 wt. parts, particularly preferably from 0.01 to 10 wt. parts per 100 wt. parts by weight of fluorinated elastomeric latex. In addition, fluorinated elastomeric latex can be frozen for coagulation.

The coagulated fluorinated elastomer is preferably collected by filtration and washed with wash water. The wash water may be, for example, deionized water, pure water or ultrapure water. The amount of washing water can be from 1 to 5 times more by mass than the fluorinated elastomer, the amount of emulsifier attached to the fluorinated elastomer can be significantly reduced by one washing. The number of washes is preferably as small as possible for the effectiveness of the operation, and more preferably it is 1 to 3 times.

The fluorinated elastomer of the present invention obtained by coagulation is characterized in that the content of the fluorinated emulsifier represented by the formula (1) in it can be reduced. In the fluorinated elastomer of the present invention, the content of the fluorinated emulsifier represented by the formula (1) is preferably a maximum of 1000 parts by weight per million, more preferably a maximum of 500 parts per million, most preferably a maximum of 300 parts per million. Within these limits, the fluorinated emulsifier is unlikely to dissipate due to evaporation at the stage of crosslinking, and this is an excellent property from the point of view of ecology and sanitation. In addition, the evaporated fluorinated emulsifier will not need to be regenerated.

The fluorinated emulsifier contained in the waste and obtained by coagulation of the fluorinated elastomeric latex of the present invention can be regenerated and recycled in a known manner. The regeneration method may be, for example, a method for adsorbing a fluorinated emulsifier with a strongly basic anion exchange resin or a weakly basic anion exchange resin, a method for adsorbing it with a synthetic adsorbent, a method for adsorbing it with activated carbon, a method for incorporating it into a layered double hydroxide, or a method for concentrating liquid waste. The fluorinated emulsifier used in the present invention and regenerated by the above method can be recycled in a known manner.

The fluorinated elastomer of the present invention has a Mooney viscosity of preferably 5 to 200, more preferably 10 to 200, measured in accordance with Japanese standard JIS K6300 by means of a large rotor with a diameter of 38.1 mm and a thickness of 5.54 mm at a temperature of 100 ° C. when setting the preheating time to one minute, and when the rotor rotates for 4 minutes. Mooney viscosity is an indicator of the molecular weight of a fluorinated elastomer, and high Mooney viscosity means a large molecular weight of a fluorinated elastomer. When the Mooney viscosity is within the specified range, excellent plasticization operation efficiency and excellent physical characteristics of the elastomer after crosslinking will be achieved.

The fluorinated elastomer of the present invention may undergo a crosslinking reaction in a known manner. Specific examples of the crosslinking reaction include peroxide crosslinking, polyol crosslinking, amine crosslinking and triazine crosslinking. Peroxide crosslinking is preferably used due to the higher productivity of the composition, heat resistance and chemical resistance.

Organic peroxide in cross-linking is a cross-linking agent, and preferably one that forms peroxide radicals, for example, when heated. Specifically, it can be, for example, dialkyl peroxide, such as di-tert-butyl peroxide, tert-butyl cumyl peroxide, dicumyl peroxide, α, α-bis (tert-butyl peroxy) p-diisopropylbenzene, 1,3-bis (tert-butylperoxyisopropyl) benzene 2,5-dimethyl-2,5-di-tert-butylperoxy) hexane or 2,5-dimethyl-2,5-di-tert-butylperoxy) hexane-3, 1,1-bis (tert-butylperoxy) - 3,3,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroxy peroxide, benzoyl peroxide, tert-butyl peroxybenzene, 2, 5-dimethyl-2,5-di (benzoyl peroxy) hexane, tert-butyl peroxymaleic acid or tert carbonate butylpe roxyisopropyl. Dialkyl peroxide is particularly preferred. In general, the type of organic peroxide used and its content in the fluorinated elastomer composition are selected depending on the activity of the organic peroxide, decomposition temperature, etc.

The content of organic peroxide is from 0.3 to 10 wt. parts per 100 wt. parts of fluorinated elastomer. Within this range, a vulcanizate with well-balanced physical properties such as strength and elongation will be obtained. Its content is preferably from 0.3 to 5 wt. parts, particularly preferably from 0.5 to 3 wt. parts. The fluorinated elastomer of the present invention preferably contains a crosslinking coagent. When it contains a crosslinking coagent, the resulting radicals will effectively react with a crosslinking coagent, thereby increasing the crosslinking efficiency. A crosslinking coagent may be a compound having a reactive activity with respect to peroxide radicals and radicals formed on the molecular chain of a fluorinated elastomer.

In particular, the crosslinking coagent can be, for example, triallyl cyanurate, triallyl isocyanurate, triallyl isocyanurate oligomer, trimetallyl isocyanurate, triacryl formal, triallyl trimellitate, N, N'-m-phenylenediophenyl dimethyldione dimethyldione N ', N ", N'" is a tetraallyl terephthalamide or a siloxane oligomer containing a vinyl group such as polymethyl vinyl siloxane or polymethyl phenyl vinyl siloxane. Triallyl cyanurate, triallyl isocyanurate or trimetallyl isocyanurate is particularly preferred, and triallyl isocyanurate is highly preferred.

The content of the crosslinking coagent is preferably from 0.1 to 10 wt. parts, more preferably from 0.5 to 5 wt. parts per 100 wt. parts of fluorinated elastomer. Within this range, a vulcanizate with well-balanced physical properties such as strength and elongation will be obtained.

In addition, during the crosslinking of the fluorinated elastomer of the present invention, a pigment for coloring, a filler, a reinforcing agent, or the like can be mixed with it. As the filler or reinforcing agent, there can be mentioned, for example, carbon black, titanium oxide, silicon dioxide, clay, talc or fluororubber such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polychlorotrifluoroethylene, tetrafluoroethylene and ethylene copolymer or tetrafluoroethylene copolymer.

The fluororesin molded product of the present invention can be obtained by molding together with crosslinking.

Molding can be carried out simultaneously with stitching or can be carried out before or after stitching. Molding is not specifically limited, and various molding methods may be mentioned, such as injection molding, direct compression, extrusion, and injection molding.

The crosslinking reaction is preferably carried out at 150-300 ° C. When crosslinking is carried out at a temperature in this range, a molded fluororubber product with excellent physical properties of the vulcanizate will be obtained. The crosslinking reaction is usually carried out by combining a primary crosslinking reaction (vulcanization under pressure) at a relatively low temperature and secondary crosslinking (post vulcanization) at a relatively high temperature. The temperature for conducting the primary crosslinking reaction is usually preferably from 150 to 190 ° C. The temperature for the secondary crosslinking reaction is usually preferably from 170 to 300 ° C.

Now the present invention will be explained in more detail with reference to examples. However, it should be understood that the present invention is not limited to such specific examples.

NUMBER OF PERFLUOR REMULATOR REMAINING IN THE POLYMER

10 g of dry fluorinated elastomer is exposed to a Soxhlet extractor at 100 ° C. for 8 hours using ethanol as a solvent to extract the ethanol soluble component. The concentration of the perfluoroemulsifier in the obtained extract was quantitatively analyzed using liquid chromatography-mass spectroscopy to determine the amount of perfluoroemulsifier remaining in the polymer after washing.

MOON VISCOSITY

It is measured in accordance with the Japanese standard JIS K6300 using a large rotor with a diameter of 38.1 mm and a thickness of 5.54 mm at 100 ° C, with a pre-heating time of one minute and a rotor rotation time of 4 minutes.

MEASURING THE PHYSICAL PROPERTIES OF A VOLCANIZER

The tensile strength and elongation of crosslinked fluororubber was measured in accordance with JIS K6300 using a sample cut from a 2 mm thick vulcanizate film using a No. 3 dumbbell stamp. In addition, hardness was measured in accordance with JIS K6300.

EXAMPLE 1

1500 g of deionized water, 40 g of sodium hydrogen phosphate dodecahydrate, 0.5 g of sodium hydroxide, 198 g of tert-butanol, 8 g of C ₂ F ₅ are loaded into an autoclave made of stainless steel having an internal volume of 3200 cc, equipped with a stirrer. OCF ₂ CF ₂ OCF ₂ COONH ₄ (hereinafter referred to as EEA) and 2.5 g of ammonium persulfate. In addition, an aqueous solution containing 0.4 g of EDTA (disodium ethylenediaminetetraacetate dihydrate; also referred to below) and 0.3 g of iron heptahydrate sulfate, previously dissolved in 200 g of deionized water, are also loaded into the autoclave. TFE and P were introduced so that the TFE / P molar ratio was 85/15 and the internal pressure in the reactor at 25 ° C was 2.5 MPa (excess). The stirrer was rotated at a speed of 300 rpm, and 2.5 wt.% Aqueous rongalite solution was added to initiate the polymerization reaction.

Together with the initiation of the polymerization reaction, the internal pressure in the reactor was reduced by 0.01 MPa (excess), after which a pre-prepared gaseous TFE / P mixture with a molar ratio of 56/44 was introduced to increase the internal pressure in the reactor to 2.51 MPa (excess). This operation was repeated with the sequential addition of a gaseous TFE / P mixture so that the internal pressure in the reactor was from 2.49 to 2.51 MPa (excess) to continue the polymerization reaction. When the total amount of the added gaseous mixture reached 800 g, the addition of an aqueous solution of rongalite was stopped, the internal temperature of the reactor was reduced to 10 ° C to complete the polymerization reaction. The polymerization spent 30 g of an aqueous solution of rongalite. In this way, latex was prepared from a TFE / P copolymer containing EDTA. The latex mass was 2650 g.

Latex was added to 4000 g of a 1.5 wt.% Aqueous solution of calcium chloride for salt coagulation of the latex and thereby obtaining a TFE / P copolymer. This copolymer was collected by filtration, washed with 3,500 g of deionized water and filtered, so that the copolymer was washed a total of three times. The copolymer collected by filtration was dried at 120 ° C for 12 hours to obtain 795 g of a white TFE / P copolymer. The amount of EEA remaining in it was 100 parts by weight per million. In addition, the glass transition temperature of the copolymer was -0.5 ° C. The Mooney viscosity was 180. The fluorine content of the obtained fluorinated elastomer was 58.2 wt.%, And the TFE-P copolymer had such a composition that (polymerized units based on TFE) / (polymerized units based on P) = 56.3 / 43.7 (molar ratio) as calculated based on the fluorine content.

100 wt. parts of the TFE and P copolymer subjected to heat treatment at 300 ° C, 30 wt. parts of medium-structured soot, 5 wt. parts of triallyl isocyanurate, 1 wt. part of 1,3-bis (tert-butylperoxyisopropyl) benzene (Perkadox 14 manufactured by Kayaku Akzo Corporation) and 1 wt. part of the sodium stearate was plasticized by a double roller to obtain a fluorinated elastomeric compound. The compound was subjected to primary crosslinking by a press at 170 ° C. for 20 minutes and then secondary crosslinking in an oven at 200 ° C. for 4 hours to obtain a 2 mm thick fluorinated rubber vulcanizate film. The physical properties of the fluorinated rubber vulcanizate are shown in table 1.

EXAMPLE 2

An autoclave made of stainless steel having an internal volume of 2100 cc, equipped with a stirrer, was charged with 1500 g of deionized water, 17 g of EEA and 300 g of perfluoropropyl vinyl ether (hereinafter referred to as PPVE). When stirring with an anchor stirrer at a speed of 300 rpm, the internal temperature increased to 60 ° C. After the internal temperature reached 60 ° C, TFE was introduced so that the internal pressure was 1 MPa (excess). Then 5 ml of a 2.5 wt.% Aqueous solution of ammonium persulfate was added to initiate the polymerization reaction. Simultaneously with the development of polymerization, the internal pressure in the reactor decreased by 0.01 MPa (excess), after which TFE was introduced to increase the internal pressure in the reactor to 1.01 MPa (excess). This operation was repeated with the sequential addition of gaseous TFE so that the internal pressure in the reactor was from 0.99 to 1.01 MPa (excess) to continue the polymerization reaction.

15 ml of a previously prepared liquid mixture of PPVE and BRVE with a molar ratio of 98/2 was loaded into the reactor, respectively, with each addition of 15 g of TFE gas. The addition of the liquid mixture was continued until 105 g of TFE was consumed. A total of 105 ml of the liquid mixture was added seven times. When the total amount of added gaseous TFE reached 120 g, the addition of TFE was stopped and the internal temperature of the reactor was reduced to 10 ° C. to terminate the polymerization reaction. The polymerization time was about 4.5 hours. In this way, a latex of a TFE-PPVE copolymer containing EEA was obtained. The latex mass was 2130.

Latex was added to 3000 g of 3.6 N. aqueous hydrochloric acid and latex were coagulated by adjusting the pH to obtain a TFE, PPVE and BRVE copolymer. The copolymer was filtered and washed with ultrapure water. The washing was carried out three times, and the amount of ultrapure water used for one washing was 1500 g. The copolymer was dried at 120 ° C for 12 hours to obtain 380 g of a white and transparent copolymer of TFE, PPVE and BRVE.

The obtained TFE, PPVE and BRVE copolymer had such a composition in which (polymerized units based on TFE) / (polymerized units based on PPVE) / (polymerized units based on BRVE) = 54/44/2 (molar ratio). The amount of EEA remaining was 80 parts by weight per million. The glass transition temperature of the copolymer was 0.5 ° C. Mooney viscosity was 95.

100 wt. parts of a copolymer of TFE, PPVE and BRVE, 20 wt. parts of medium-structured (MT) carbon black, 5 wt. parts of triallyl isocyanurate, 1 wt. part of 1,3-bis (tert-butylperoxyisopropyl) benzene (Perkadox 14 manufactured by Kayaku Akzo Corporation) and 3 wt. parts of magnesium oxide were plasticized by a double roller to obtain a fluorinated elastomeric compound. The compound was first crosslinked by extrusion at 170 ° C. for 20 minutes and then secondarily crosslinked in an oven at 200 ° C. for 4 hours to obtain a 2 mm thick fluorinated rubber vulcanizate film. The physical properties of the fluorinated rubber vulcanizate are shown in table 1.

EXAMPLE 3

In an autoclave made of stainless steel having an internal volume of 2100 cc, equipped with a stirrer, 708 g of deionized water, 7.08 g of EEA, 0.6 g of sodium hydrogen phosphate dodecahydrate, 1.62 g of 1,4-diiodoperfluorobutane and 50 were charged g perfluoromethylvinyl ether (hereinafter referred to as PMVE). When stirring with an anchor stirrer at a speed of 600 rpm, the internal temperature was raised to 80 ° C. After the internal temperature reached 80 ° C, TFE was introduced with its own pressure so that the internal pressure in the reactor was 0.6 MPa (excess). Then, 10 ml of a 0.5 wt.% Aqueous solution of ammonium persulfate was added to initiate the polymerization reaction. Simultaneously with the development of polymerization, the internal pressure in the reactor decreased by 0.01 MPa (excess), after which TFE was introduced to increase the internal pressure in the reactor to 0.61 MPa (excess). This operation was repeated by sequentially adding TFE gas, so that the internal pressure in the reactor was from 0.59 to 0.61 MPa (excess) to continue the polymerization reaction.

Then, 8 g of TFE gas was added, 10 ml of PMVE was loaded into the reactor under nitrogen pressure in accordance with each addition of 16 g of TFE gas. The addition of PMVE was continued until 136 g of TFE was consumed. PMVE was added only nine times in a total amount of 90 ml. At times when the added amount of TFE gas was 50 g and 100 g, 10 ml of a 0.5 wt.% Aqueous solution of ammonium persulfate was added. When the total amount of TFE gas added reached 140 g, the addition of TFE was stopped and the internal temperature of the reactor was reduced to 10 ° C. to terminate the polymerization reaction. The polymerization time was about 17 hours. In this way, the latex of the TFE-PMVE copolymer containing EEA was obtained. The latex mass was 1012 g.

Latex was added to 1500 g of a 3 wt.% Aqueous solution of potassium sulfate and aluminum, and the latex was coagulated by salt coagulation to obtain a TFE-PMVE copolymer. The copolymer was subjected to filtration and washing with ultrapure water. The washing was carried out three times and the amount of pure water used for one washing was 1200 g. The copolymer was dried in vacuum at 50 ° C for 24 hours to obtain 250 g of a white transparent copolymer of TFE and PMVE containing iodine.

The obtained TFE-PMVE copolymer had such a composition in which (polymerized units based on TFE) / (polymerized units based on PMVE) = 68/32 (molar ratio). The amount of EEA remaining was 50 parts by weight per million. In addition, the glass transition temperature of the copolymer was -4.7 ° C. Mooney viscosity was 25.

100 wt. parts of a copolymer of TFE and PMVE containing iodine, 20 mass. parts of triallyl isocyanurate, 1 wt. part of 2,5-dimethyl-2,5-di (tert-butyl peroxy) hexane (Perhexa 25 V, manufactured by NOF CORPORATION) and 0.5 wt. parts of o-phenylphenol were plasticized by a double roller to obtain a fluorinated elastomeric compound. The compound was subjected to primary crosslinking by means of a press at 170 ° C for 20 minutes and then subjected to secondary crosslinking in an oven at 250 ° C for 4 hours to obtain a 2 mm thick fluorinated rubber vulcanizate film. The physical properties of the fluorinated rubber vulcanizate are shown in table 1.

EXAMPLE 4

In an autoclave made of stainless steel having an internal volume of 2100 cc, equipped with a stirrer, 840 g of deionized water and 1.68 g of EEA were charged, and the system in the reactor was replaced with nitrogen, and then the internal temperature was raised to 80 ° C while stirring the anchor agitator at a speed of 600 rpm After the internal temperature reached 80 ° C, a pre-prepared gas mixture VDF / HFP = 65/35 (molar ratio) was introduced so that the internal pressure in the reactor was 0.75 MPa (excess). Then, 10 ml of a 2.0 wt.% Aqueous solution of ammonium persulfate was added to initiate the polymerization reaction. Along with the development of polymerization, the internal pressure in the reactor was reduced by 0.01 MPa (excess), after which a pre-prepared gaseous mixture VDF / HFP = 78/22 (molar ratio) was introduced at its own pressure to increase the internal pressure in the reactor so that it (pressure) was 0.76 MPa (excess). This operation was repeated with the sequential addition of a gaseous mixture of VDF / HFP = 78/22 (molar ratio) so that the internal pressure in the reactor was from 0.74 to 0.76 MPa (excess) to continue the polymerization reaction.

When the total amount of the gaseous mixture of VDF / HFP = 78/22 (molar ratio) reached 50 g, the supply of the gaseous mixture of VDF / HFP was stopped and the internal temperature of the reactor was reduced to 10 ° C to terminate the polymerization reaction. The polymerization time was about 3 hours. In this way, the latex of the VDF / HFP copolymer containing EEA was obtained. The latex mass was 895 g.

Latex was added to 1500 g of a 3 wt.% Aqueous solution of potassium sulfate and aluminum, and latex was coagulated by salt coagulation to obtain a VDF-HFP copolymer. The copolymer was filtered and washed with ultrapure water. The washing was carried out three times, and the amount of ultrapure water used for one washing was 1200 g. The copolymer was dried at 120 ° C for 12 hours to obtain 49 g of a white copolymer of VDF and HFP.

The obtained VDF-HFP copolymer had such a composition in which (polymerized units based on VDF) / (polymerized units based on HFP) = 78/22 (molar ratio). The amount of EEA remaining in the VDF-HFP copolymer was 300 parts by weight per million. In addition, the glass transition temperature of the copolymer was -20.5 ° C. Mooney viscosity was 30.

100 wt. parts of a copolymer of VDF and HFP, 20 wt. parts of medium-structured soot, 4 wt. parts of triallyl isocyanurate and 1.5 wt. parts of 2,5-dimethyl-2,5-di (tert-butyl peroxy) hexane (Perhexa 25 V, manufactured by NOF CORPORATION) were double-plastified to produce a fluorinated elastomeric compound. The compound was subjected to primary crosslinking by means of a press at 160 ° C. for 10 minutes and then subjected to secondary crosslinking in an oven at 180 ° C. for 4 hours to obtain a 2 mm thick fluorinated rubber vulcanizate film. The physical properties of the fluorinated rubber vulcanizate are shown in table 1.

EXAMPLE 5

After the air was removed from an autoclave made of stainless steel with an internal volume of 3200 ml and equipped with an anchor stirrer, 1600 g of deionized water, 40 g of sodium hydrogen phosphate dodecahydrate, 0.5 g of sodium peroxide were loaded into it g of tert-butanol, 9 g of EEA and 2.5 g of ammonium persulfate. In addition, an aqueous solution was loaded into it containing 0.4 g of disodium ethylene diamine tetraacetate dihydrate (hereinafter referred to as EDTA) and 0.3 g of iron heptahydrate sulfate, previously dissolved in 200 g of deionized water. Then, a gaseous mixture of TFE / P = 85/15 monomers (molar ratio) was introduced at a temperature of 40 ° C so that the internal pressure in the reactor was 2.5 MPa (excess). The anchor stirrer was rotated at a speed of 300 rpm, and a 2.5 wt.% Aqueous solution of hydroxymethanesulfinate dihydrate (hereinafter sometimes referred to as rongalite) was added, having a pH adjusted to 10.0 with sodium peroxide (hereinafter, this aqueous solution would be called 2.5 wt. % aqueous solution of rongalite), to initiate the polymerization reaction. Then A 2.5 wt.% Aqueous rongalite solution was continuously added via a high pressure pump.

Due to the fact that the pressure decreased with the development of polymerization, with a decrease in the internal pressure in the reactor to 2.49 MPa (excess), a gaseous mixture TFE / P = 56/44 (molar ratio) was introduced at its own pressure to increase the internal pressure in the reactor up to 2.51 MPa (excess). This operation was repeated to maintain the internal pressure in the reactor from 2.49 to 2.51 MPa (excess) to continue the polymerization reaction. When the amount of the added gaseous TFE / P mixture reached 10 g, 2 ml of a pre-prepared solution of cretone vinyl (hereinafter referred to as KPV) / (tert-butanol) = 5/95 (molar ratio) was loaded into the reactor under a reverse nitrogen pressure. In addition, until the amount of the added gaseous TFE / P mixture reached 790 g, 2 ml of a solution of FOC in tert-butanol was added in accordance with each addition of 10 g of a gaseous mixture of TFE / P and 158 ml of the solution was completely loaded. When the total amount of the added TFE / P gaseous mixture reached 800 g, the addition of 2.5 wt.% Aqueous rongalite solution was stopped and the internal temperature of the reactor was lowered to 10 ° C to complete the polymerization reaction and thereby to obtain the latex of the TFE, P and KPV copolymer. The amount of 2.5 wt.% Aqueous rongalite solution used was 45 g.

Latex was added to a 5 wt.% Aqueous solution of calcium chloride, and the latex was coagulated by salt coagulation to precipitate a TFE, P, and Raman copolymer. The copolymer was collected by filtration, washed with deionized water and dried in an oven at 120 ° C for 12 hours to obtain 798 g of a white copolymer of TFE, P and KRV. The copolymer had a composition determined by IR absorption spectroscopy and ¹³ C-NMR, in which (polymerized units based on TFE) / (polymerized units based on P) / (polymerized units based on Raman scattering) = 55.8 / 44.2 / 0 , 2 (molar ratio). In addition, the Mooney viscosity was 120, the glass transition temperature was −0.5 ° C., and the amount of EEA remaining was 90 parts by weight per million.

100 wt. parts of a copolymer TFE, P and KRV, 30 wt. parts of medium-structured soot, 5 wt. parts of triallyl isocyanurate, 1 wt. part of 1,3-bis (tert-butylperoxyisopropyl) benzene (Percadoxy 14 manufactured by Kayaku Akuso Corporation) and 1 wt. part of the magnesium oxide was plasticized by a double roller to obtain a fluorinated elastomeric compound. The compound was subjected to primary crosslinking by a press at 170 ° C. for 20 minutes and then secondary crosslinking in an oven at 200 ° C. for 4 hours to obtain a 2 mm thick fluorinated rubber vulcanizate film. The physical properties of the fluorinated rubber vulcanizate are shown in table 1.

COMPARATIVE EXAMPLE 1

The latex of the TFE-P copolymer was obtained as in Example 1, except that ammonium perfluorooctanoate (hereinafter referred to as PFOA) was used as an emulsifier. The latex was subjected to coagulation, washing and drying, as in example 1, to obtain 786 g of a TFE-P copolymer. The copolymer had a fluorine content of 57.9 wt.% And had a composition in which (polymerized units based on TFE) / ( polymerized units based on P) = 55.8 / 44.2 (molar ratio), as calculated based on the fluorine content. The amount of remaining PFOA was 2300 parts by weight per million. In addition, the glass transition temperature of the copolymer was -0.3 ° C. The Mooney viscosity was equal to 178. A film of fluoropolymer vulcanizate was obtained as in example 1, and its physical properties are shown in table 1.

COMPARATIVE EXAMPLE 2

369 g of a copolymer of TFE, PPVE and BRVE were obtained as in Example 2, except that PFOA was used as an emulsifier instead of EEA. The polymerization time was about 5.5 hours. Analysis by ¹⁹ F-NMR showed that the copolymer had such a composition in which (polymerized units based on TFE) / (polymerized units based on PPVE) / (polymerized units based on BRVE) = 59/39/2 (molar ratio). The amount of remaining PFOA was 1300 ppm. In addition, the glass transition temperature was -0.1 ° C. The Mooney viscosity was 90. A fluorinated rubber vulcanizate film was prepared as in Example 2, and its physical properties are shown in Table 1.

COMPARATIVE EXAMPLE 3

220 g of a copolymer of TFE and PMVE containing iodine were obtained as in Example 3, except that PFOA was used as an emulsifier instead of EEA. Analysis by ¹⁹ F-NMR showed that the copolymer had a composition such that (polymerized units based on TFE) / (polymerized units based on PMVE) = 67/33 (molar ratio). The amount of PFOA remaining was 1,200 ppm. In addition, the glass transition temperature of the copolymer was -4.8 ° C. The Mooney viscosity was 23. A fluorinated rubber vulcanizate film was prepared as in Example 3, and its physical properties are shown in Table 1.

COMPARATIVE EXAMPLE 4

48 g of a VDF-HFP copolymer were obtained as in Example 4, except that PFOA was used as an emulsifier instead of EEA. Analysis by ¹⁹ F-NMR showed that the copolymer had a composition such that (polymerized units based on VDF) / (polymerized units based on HFP) = 77/23 (molar ratio). The amount of remaining PFOA was 3,000 ppm. In addition, the glass transition temperature of the copolymer was -20.0 ° C. The Mooney viscosity was 32. A fluorinated rubber vulcanizate film was prepared as in Example 4, and its physical properties are shown in Table 1.

TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 The composition of the copolymer TFE and P TFE, PPVE and BRVE TFE and PMVE (contains iodine) VDF and HFP TFE, P and KRV TFE and P TFE, PPVE and BRVE TFE and PMVE (contains iodine) VDF and HFP The amount of remaining emulsifier (parts by weight / million) one hundred 80 fifty 300 90 2300 1300 1200 3000 Glass transition temperature, ° С -0.5 0.5 -4.7 -20.5 -0.5 -0.3 0.1 -4.8 -20.0 Mooney Viscosity 180 95 25 thirty 120 178 90 23 32 Tensile Strength, MPa 16,2 18.0 20.8 20.5 18.0 16.1 17.0 20,0 20,0 Elongation,% 300 230 188 400 185 290 220 190 410 Modulus at 100% elongation, MPa 3,7 8.0 10.3 2.0 6.7 3,7 8.0 10.0 2.0 Hardness (Shore A) 70 75 86 66 71 70 75 85 66

COMPARATIVE EXAMPLE 5

A TFE / P copolymer latex was prepared in the same manner as in Example 1, except that instead of EEA, an emulsifier used CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH ₄ (hereinafter abbreviated like EPRA; can be obtained as shown in Reference Example 1 below). The latex was subjected to coagulation, washing and drying in the same manner as in example 1, to obtain 680 g of a TFE / P copolymer. The copolymer had a fluorine content of 58.0 wt.% And had such a composition that the molar ratio (polymerized units based on TFE) / (polymerized units based on P) = 55.9 / 44.1, as was calculated based on the fluorine content. The glass transition temperature for the resulting copolymer was -0.5 ° C.

For the latex according to this Comparative Example 5, as well as for the latex according to Example 1 and Comparative Example 1, the residual amount of the perfluorinated emulsifier in the polymer was determined as described above, but using acetone instead of ethanol as a solvent in the Soxhlet extractor.

Moreover, the results obtained for Example 1 and Comparative example 1 were the same as when using ethanol as a solvent. In Comparative Example 5, the residual amount of the EPPA perfluorinated emulsifier was 3000 parts by weight per million (see table 2 below).

BIOACCUMULATION TEST: Measurement of the distribution coefficient between 1-octanol and water (LogPOW).

In order to judge whether or not some chemical substance is capable of bioaccumulation, i.e. accumulation in a living organism, there is a test procedure for measuring the distribution coefficient between 1-octanol and water (LogPOW) according to the OECD Test Guideline and the Japanese Industrial Standards. A compound having a high value of said distribution coefficient (LogPOW) has a high tendency to bioaccumulate, and a compound having a small value of said distribution coefficient has a low tendency to bioaccumulate. In cases where the LogPOW value is less than 3.5, it is considered reasonable that the concentration of the substance is low, and its bioaccumulation is considered low.

The distribution coefficient between 1-octanol and water (LogPOW) in these Examples was measured in accordance with the OECD Test Guideline (OECD Test Guideline 117) using high performance liquid chromatography (HPLC).

HPLC was performed under the following conditions and equipment specifications:

Column: TOSOH ODS-120T (diameter 4.6 mm, length 250 mm)

Solvent: acetonitrile / 0.6 wt.% Aqueous solution of HClO ₄ = 1/1 (vol./vol.%)

Flow rate: 1.0 ml / min

Sample amount: 300 μl

Column temperature: 40 ° C

Detecting radiation: UV 210 nm

HPLC was performed on standard substances (heptanoic acid, octanoic acid, nonanoic acid and decanoic acid) for which the partition coefficient between 1-octanol and water is known, and a calibration curve was constructed based on the elution time and partition coefficient between 1-octanol and water for each of the standard substances. Based on the calibration curve, the LogPOW value (partition coefficient between 1-octanol and water) for the fluorinated emulsifiers tested was calculated from their elution time in HPLC.

The results of determining LogPOW are presented in table 2.

COMPARATIVE EXAMPLE 6

For the compound CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ COO ^- (NH ₄ ) ⁺ (hereinafter abbreviated as REA; can be obtained as shown in Reference example 2 below), a bioaccumulation test was carried out in the same manner as described above for the EEA compound. The results of determining LogPOW are presented in table 2.

table 2 Fluoride emulsifier The residual amount in fluororubber (parts by weight / million) Accumulation in living organisms (LogPOW value), Example 1 (EEA) C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COONH ₄ one hundred 3.13 Comparative Example 1 (APFO) CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ COONH ₄ 2300 3.67 Comparative Example 5 (EPPA) CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH ₄ 3000 4.03 Comparative Example 6 (REA) CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ COONH ₄ 3.74

The EPPA compound known in the art can be considered as a fluorinated emulsifier having a structure similar to the fluorinated emulsifier of the present invention. In this regard, the authors of the present invention conducted a comparative test for the amount of residual emulsifier in fluororubber between APFO (the emulsifier commonly used in the preparation of fluoropolymers, as mentioned above), EPPA and the fluorinated emulsifier of the present invention. As can be seen from table 2, in the case of the fluorinated emulsifier of the present invention (example 1, EEA), its residual amount is significantly lower than that in comparative example 1 and comparative example 5.

In addition, a comparative test was conducted between the same emulsifiers for bioaccumulation (which is a problem in the case of APFO).

As can be seen from table 2, the value of LogPOW for EEA is low compared with ammonium perfluorooctanoate (APFO, comparative example 1), and therefore, it was found that its (EEA) bioaccumulation is reduced. On the other hand, in the case of EPRA in comparative example 5, the structure of the latter is similar to EEA, however, the LogPOW value is higher even in comparison with APFO as a characteristic substance for which there is a bioaccumulation problem.

So, the EEA fluorinated emulsifier of the present invention provides a remarkable technical result, consisting in the fact that its residual amount in the fluororubber is very low, and the accumulation in living organisms is small compared to the EPRA emulsifier.

In addition, the authors of the present invention additionally measured bioaccumulation (LogPOW value) also for the compound CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ COONH ₄ (PEA) as the structure closest to the emulsifier of the present invention.

As can be seen from the results for comparative example 6 in table 2, the bioaccumulation of REA is great compared to the EEA (fluorinated emulsifier according to the present invention), as well as compared to the APFO emulsifier generally accepted in the art. That is, the present invention achieves a remarkable bioaccumulation effect that is small for EEA compared to REA.

Thus, even for a minimally different compound REA (end perfluoropropyl group instead of perfluoroethyl), bioaccumulation is noticeably higher than for EEA according to the present invention.

BACKGROUND EXAMPLE 1: Preparation of fluorinated emulsifier CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH ₄ (EPPA)

In an autoclave made of Hastelloy C alloy having an internal volume of 200 ml, 2.58 g of CsF and 13.06 g of tetraglim were charged, deaerated, and then 20.83 g of CF ₃ OF was introduced. Then the autoclave was cooled to −20 ° C. and 57.5 g of hexafluoropropenoxide was introduced with stirring in a closed volume for about 1 hour. The initial pressure was 0.6 MPa. Stirring was continued for about 1 hour until the pressure drop stopped, after which the pressure was returned to atmospheric pressure and 78.57 g of crude reaction liquid was obtained. The crude reaction liquid was analyzed by gas chromatography (GC), and it was confirmed that the crude product contained 49.7% of the target material CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COF, 19.1% CF ₃ CF ₂ OCF (CF ₃ ) COF and 12.8% CF ₃ CF ₂ O (CF (CF ₃ ) CF ₂ O) ₂ CF (CF ₃ ) COF.

The reaction was carried out in the same manner, except that 32.26 g of CF ₃ COF were used.

Two portions of the crude reaction liquid containing the target substance were combined together and purified by distillation. 52.47 g of the target product having a boiling point of 71 ° C / 400 mmHg was obtained using a 30 cm tall distillation column filled with a Helipack NO.1 nozzle and equipped with a reflux condenser. The target product was discharged into a reactor made of PTFE, and 2.32 g of water was added dropwise with stirring to carry out hydrolysis. Then, hydrogen fluoride was removed by passing nitrogen bubbles to obtain 50.45 g of CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOH as a crude (crude) liquid. The crude liquid was subjected to simple distillation using a conventional glass distillation apparatus to obtain 40 g CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOH. Then, 40 g of CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COOH were neutralized with NH ₄ . 40 g of said carboxylic acid was dissolved in 150 g of CClF ₂ CF ₂ CHClF in a glass reactor, and 10.89 g of a 28% aqueous ammonia solution was added dropwise to this solution at room temperature to give an ammonium salt. The solvent (CClF ₂ CF ₂ CHClF) was distilled off, followed by drying under reduced pressure to obtain 39.4 g of CF ₃ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH ₄ as a white substance.

BACKGROUND EXAMPLE 2: Preparation of Fluorinated Emulsifier CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ COONH ₄ (REA)

Stage 1-1

Preparation of CH ₃ CH ₂ CH ₂ O (CH ₂ ) ₂ O (CH ₂ ) ₂ OCOCF (CF ₃ ) OCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₃

An autoclave made of Hastelloy C alloy having an internal volume of 2 L was charged with 500 g of CH ₃ CH ₂ CH ₂ O (CH ₂ ) ₂ O (CH ₂ ) ₂ OH. The autoclave was cooled and 1764 g of CF ₃ CF ₂ CF ₂ CF ₂ OCF (CF ₃ ) OCF (CF ₃ ) COF was gradually added while stirring in a closed volume and maintaining the internal temperature in the reactor at 30 ° C or less. After the entire amount was introduced, stirring was carried out at 30 ° C for another 3 hours, and then the HF formed during the reaction was removed from the system by passing nitrogen bubbles to obtain the product. As a result of GC analysis of the product, it was found that the target substance CH ₃ CH ₂ CH ₂ O (CH ₂ ) ₂ O (CH ₂ ) ₂ OCOCF (CF ₃ ) OCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF _{3 was} formed in 98.8%, and unreacted CH ₃ CH ₂ CH ₂ O (CH ₂ ) ₂ O (CH ₃ ) ₂ OH was not detected. This product was used in the next step without purification.

Stage 1-2: Getting

CF ₃ CF ₂ CF ₂ O (CF ₂ ) ₂ O (CF ₂ ) ₂ OCOCF (CF ₃ ) OCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF _{3 by} fluorination

In an autoclave made of nickel and having an internal volume of 500 ml, 312 g of R-113 was added and then stirring was carried out in a closed volume while maintaining the internal temperature in the reactor at 25 ° C. At the outlet of the autoclave, a refrigerator (condenser) maintained at a temperature of 20 ° C, a column filled with NaF granules, and a refrigerator (condenser) maintained at a temperature of -10 ° C were sequentially located. In addition, a liquid return line was equipped to return the condensed liquid from the refrigerator with a temperature of -10 ° C to the autoclave. After nitrogen gas was introduced into the autoclave at room temperature for 1 hour, then fluorine gas diluted with 20% nitrogen gas (hereinafter referred to as 20% fluorine gas diluted) was introduced into it at a flow rate of 17, 04 l / hr. Then, while fluorine gas diluted by 20% was introduced at the same volumetric flow rate, 10 g of the product obtained in stage 1-1, which was dissolved in 150 g of R-113, were injected into the autoclave for more than 4, 1 hour

After that, when fluorine gas was supplied at the same volumetric flow rate, the pressure in the autoclave was increased to 0.15 MPa (excess). 9 ml of the solution was injected into R-113 with a benzene concentration of 0.01 g / ml, while the internal temperature was raised from 25 to 40 ° C, and then the inlet of the autoclave for injecting the solution into R-113 was closed and stirring was continued for 0.3 hours.

Then, while maintaining the pressure inside the autoclave at 0.15 MPA (excessive), and the temperature inside the autoclave at 40 ° C, 6 ml of the solution was injected into R-113, and then the inlet of the autoclave for injecting the solution into R-113 was blocked and mixing continued for 0.3 hours. Then the same operation was repeated once more. The total amount of injected benzene was 0.22 g, and the total amount of injected R-113 was 21 ml.

Then, stirring was continued for 1 hour with the introduction of diluted by 20% gaseous fluorine with the same volumetric flow rate. Then, the pressure in the autoclave was returned to atmospheric pressure and nitrogen gas was introduced for 1 hour. As a result of analysis of the product by ¹⁹ F-NMR, it was found that the target substance is contained in the product in an amount corresponding to a yield of 93%.

Step 1-3: Preparation of CF ₃ CF ₂ CF ₂ O (CF ₂ ) ₂ OCF ₂ COF by Dissociation of CF ₃ CF ₂ CF ₂ O (CF ₂ ) ₂ O (CF ₂ ) ₂ OCOCF (CF ₃ ) OCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₃

2000 g of CF ₃ CF ₂ CF ₂ O (CF ₂ ) ₂ O (CF ₂ ) ₂ OCOCF (CF ₃ ) OCF ₂ CF was charged into a 2 L autoclave with a distillation column equipped with a reflux condenser at a temperature of 10 ° C. (CF ₃ ) OCF ₂ CF ₂ CF ₃ obtained in the previous step 1-2, and then 15.9 g of potassium fluoride was added, followed by stirring under heating (heat carrier temperature: from 100 to 130 ° C), and then fractions were collected using a reaction / distillation system. 894 g of a fraction with a purity of at least 99% were obtained as the main fraction. The boiling point was 67 ° C (400 mmHg), and the yield was 82.0%.

Stage 1-4: Obtaining CF ₃ CF ₂ CF ₂ O (CF ₂ ) ₂ OCF ₂ COOH by hydrolysis

In an autoclave made of Hastelloy alloy having an internal volume of 200 ml, 100 g of compound CF ₃ CF ₂ CF ₂ O (CF ₂ ) ₂ OCF ₂ COF obtained in the previous step 1-3 was charged. Then, under ice cooling, hydrolysis was carried out by gradually adding dropwise 5 ml of water with vigorous stirring. After completion of the addition of water, the internal temperature was gradually raised to room temperature, and then stirring was continued for 5 hours. Then, the HF formed in the reaction was removed by passing nitrogen bubbles and then a single distillation was carried out, as a result of which a fraction was obtained with a boiling point of 70 ° C (200 mmHg). The purity was 99.0%, and the yield was 75%.

Stage 1-5: Obtaining CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ COO ^- (NH ₄ ) ⁺ neutralization with ammonia

A 50 g CF ₃ CF ₂ CF ₂ O (CF ₂ ) ₂ OCF ₂ COOH obtained in the previous step 1-4 was charged into a glass autoclave equipped with a stirrer and a partial condenser of hot irrigation, and gradually added while cooling with ice. dropwise 28% ammonia water with vigorous stirring. After completion of the dropwise addition, the internal temperature was gradually raised to 40 ° C., and this temperature was maintained for 5 hours. Then, the solvent and water were distilled off under reduced pressure, avoiding boiling of the liquid, and 52.0 g of the target compound CF ₃ CF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ COO ^- (NH ₄ ) ⁺ were obtained.

The fluorinated elastomeric latex of the present invention is suitable for the production of a fluorinated elastomer. In addition, it can be used as an aqueous coating when mixed with various additives. The fluorinated elastomer of the present invention is characterized by heat resistance, oil resistance, chemical resistance, resistance to solvents, incohesion, high electrical characteristics, sanitary specifications, etc .; and therefore it is widely used in areas such as the semiconductor industry, the chemical industry, the food industry, the petrochemical industry, the electrical industry, the automotive industry, and in the technology as a sealing material, such as material for the manufacture of O-rings, pipes, hoses, diaphragms, belts insulation for wires, gaskets, etc.

All descriptions of Japanese patent application No. 2005-61233, registered on March 4, 2005, and Japanese patent application No. 2005-291572, registered on October 4, 2005, including descriptions, claims and abstracts, are mentioned here for information in full.

Claims (8)

1. Fluorinated elastomeric latex containing a fluorinated emulsifier represented by the formula (1)
C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOA,
where A is a hydrogen atom, an alkali metal or NH _4, and the fluorinated elastomer is a polymer of at least one fluoromonomer selected from the group consisting of tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, perfluoro (alkyl or alkyloxyalkyl vinyl ether) represented by the formula CF ₂ = C (OR ^f ) _n F _2-n , where R ^f is a C _1-9 perfluoroalkyl group or a perfluoro (alkyloxyalkyl) group containing one or more ether bonds, n is an integer of 1 or 2, and each carbon chain maybe l linear or contain branches, or may have a cyclic structure, and chlorotrifluoroethylene, and, if necessary according to circumstances, at least one hydrocarbon monomer selected from the group consisting of vinyl ether represented by CH ₂ = CHOR, wherein R is a C _{1- 8} alkyl group or alkyloxyalkyl group containing one or more ether bonds, and each carbon chain may be linear or may contain branches, or may have a cyclic structure, ethylene and propylene, and if required It floats on the circumstances, from 0.001 to 10 mol.% of the monomer having a crosslinkable group. 2. The fluorinated elastomeric latex according to claim 1, wherein the fluorinated elastomer is at least one copolymer selected from the group consisting of a tetrafluoroethylene and propylene copolymer, a tetrafluoroethylene copolymer, propylene and vinylidene fluoride, a tetrafluoroethylene copolymer and hexafluoropropylene copolymer and vinylidene fluoride fluoride fluoride propylene copolymer a copolymer of tetrafluoroethylene, vinylidene fluoride and hexafluoropropylene, a copolymer of tetrafluoroethylene and CF ₂ = CFOCF ₃ , a copolymer of tetrafluoroethylene and CF ₂ = CFOC ₃ F ₇ , a copolymer of tetrafluoroethylene, CF ₂ = CFOCF ₃ and CF ₂ = CFOC ₃ F ₇ , a copolymer of tetrafluoroethylene and CF ₂ = C (OC ₂ F ₅ ) ₂ , a copolymer of tetrafluoroethylene and methyl vinyl ether, a copolymer of tetrafluoroethylene and ethyl vinyl ether, a copolymer of tetrafluoroethylene and n-butyl vinyl ether copolymer of tetrafluoroethylene, ethyl vinyl ether and n-butyl vinyl ether, copolymer of vinylidene fluoride and CF ₂ = CFOC ₃ F ₇ copolymer of ethylene and hexafluoropropylene, and the like listed copolymer which comprises a monomer having a crosslinkable group and being con limerizuemym with them. 3. The fluorinated elastomeric latex according to claim 1, wherein the fluorinated elastomer is at least one copolymer selected from the group consisting of a tetrafluoroethylene copolymer (from 40 to 60 mol%) and propylene (from 60 to 40 mol% ), a copolymer of tetrafluoroethylene (20 to 79 mol%), propylene (79 to 20 mol%) and vinylidene fluoride (1 to 50 mol%), a copolymer of tetrafluoroethylene (20 to 80 mol%) and hexafluoropropylene ( from 80 to 20 mol.%), a copolymer of vinylidene fluoride (from 50 to 95 mol.%) and hexafluoropropylene (from 5 to 50 mol.%), a copolymer of tetrafluoroethylene (1 to 35 mol.%), vinylide enfluoride (from 45 to 90 mol.%) and hexafluoropropylene (from 5 to 50 mol.%), a tetrafluoroethylene copolymer (from 40 to 70 mol.%) and CF ₂ = CFOCF ₃ (from 60 to 30 mol.%), a copolymer tetrafluoroethylene (40 to 70 mol%) and CF ₂ = CFOC ₃ F ₇ (60 to 30 mol%), a copolymer of tetrafluoroethylene (40 to 70 mol%) and CF ₂ = C (OC ₂ F ₅ ) ₂ (from 60 to 30 mol.%), A copolymer of tetrafluoroethylene (from 70 to 30 mol.%) And methyl vinyl ether (from 30 to 70 mol.%), A copolymer of tetrafluoroethylene (from 70 to 30 mol.%) And ethyl vinyl ether ( from 30 to 70 mol.%), a tetrafluoroethylene copolymer (from 70 to 30 mol.%) and n-butyl vinyl ether (from 30 to 70 mol.%), a tetraf copolymer orthylene (60 to 30 mol%), ethyl vinyl ether (1 to 69 mol%) and n-butyl vinyl ether (1 to 69 mol%), vinylidene fluoride copolymer (40 to 70 mol%) and CF ₂ = CFOC ₃ F ₇ (from 60 to 30 mol.%), A copolymer of ethylene (from 40 to 60 mol.%) And hexafluoropropylene (from 60 to 40 mol.%) And a similar copolymer of the above, which contains from 0.001 to 10 mol. .% monomer containing a crosslinkable group and being copolymerizable with them. 4. A method of obtaining a fluorinated elastomeric latex, which includes emulsion polymerization of fluoromonomer in an aqueous medium containing from 0.001 to 10 wt.% Fluorinated emulsifier represented by the formula (1): C ₂ F ₅ OCF ₂ CF ₂ OCF ₂ COOA, where A is a hydrogen atom, an alkali metal, or NH ₄ to produce a fluorinated elastomeric latex in which the fluoromonomer is at least one fluoromonomer selected from the group consisting of tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, perfluoro (alkyl or alkyloxyalkyl vinyl ether) represented by the formula CF ₂ = C (OR ^f ) _n F _2-n , where R ^f is a C _1-9 perfluoroalkyl group or a perfluoro (alkyloxyalkyl) group containing one or more ether bonds in its molecule, n is an integer of 1 or 2, and each carbon chain may be linear or contain branches, or may have a cyclic structure, and chlorotrifluoroethylene, and, if necessary, at least one hydrocarbon monomer selected from the group consisting of vinyl ether represented by formulas oh CH ₂ = CHOR, where R is a C _1-8 alkyl group or an alkyloxyalkyl group containing one or more ether bonds, and each carbon chain may be linear or contain branches, or may have a cyclic structure of propylene and ethylene, and, if necessary, from 0.001 to 10 mol.% of a monomer containing a crosslinkable group and copolymerizable with them. 5. The method according to claim 4, in which the fluoromonomer is subjected to emulsion polymerization in the presence of C _n F _m I _{2n + 2-m} , where n is an integer from 1 to 16, and m is an integer from 1 to (2n + 1) ), as a regulator of the degree of polymerization. 6. Fluorinated elastomer obtained by coagulation of a fluorinated elastomeric latex according to any one of claims 1 to 3. 7. The fluorinated elastomer according to claim 6, which has a Mooney viscosity of 5 to 200, measured in accordance with Japanese standard JIS K6300, which uses a large rotor with a diameter of 38.1 mm and a thickness of 5.54 mm at 100 ° C with installation preheating time for 1 min; and rotor rotation time for 4 min. 8. A molded product of fluororubber obtained by crosslinking a fluorinated elastomer according to claim 6 or 7.