JP2016132753A - Fluoropolymer component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluoropolymer component excellent in amine resistance, oil resistance and low temperature resistance and low in cost.SOLUTION: There is provided a fluoropolymer component which is used for search, boring or production of petroleum or gas and is obtained by crosslinking a crosslinkable composition containing a fluorine-containing polymer having a glass transition temperature of 25°C or less and a crosslinking agent, where the fluorine-containing polymer is a copolymer consisting of vinylidene fluoride and a fluorine-containing monomer (1) represented by the following general formula (1):CH=CFRf (1), where Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms.SELECTED DRAWING: None

Description

The present invention relates to fluoropolymer parts.

Patent Document 1 discloses that a mining part of a rotary type mining apparatus used for oil mining is exposed to high temperature, high pressure, and an acidic atmosphere, and therefore, mining parts are required to have heat resistance, acid resistance, and high strength. Therefore, it is described that a tetrafluoroethylene / propylene copolymer is particularly preferably used as the fluororubber. Further, it is described that a hydrophobic silica is contained in a composition containing a tetrafluoroethylene / propylene copolymer in order to obtain good hardness and good elongation in a rubber article after crosslinking.

According to Patent Document 2, a perfluoroelastomer molded product used in an oil drilling rig may be damaged by sudden decompression when the pressure existing in a deep well is suddenly released. It is described that the sealing characteristics cannot be maintained. And surprisingly, it has been described that cured perfluoroelastomer molded articles containing high levels of carbon black and perfluoropolyether have good rapid pressure resistance while maintaining acceptable sealing properties.

In US Pat. No. 6,099,089, fluoroelastomer parts for use in oil and gas exploration and production are exposed to very high temperatures and pressures during use, and are typically resistant to extrusion and wear under high pressure. It is described that it is required to be sufficiently hard. And as a cured fluoroelastomer part that achieves the well-balanced high temperature and high pressure mechanical properties and hardness of the fluoroelastomer part for exploration and production of oil and gas, fluoroelastomer, and 70-150 m with ² / nitrogen adsorption specific area ^(N 2 SA) of g and 90～180Ml / 100 g dibutyl phthalate (DBP) absorption, cured fluoroelastomer containing carbon black exceeding 20 parts by weight per 100 parts by weight perfluoroelastomer Parts are proposed.

Patent Document 4 describes that, since the mining elongation has become deeper, it is necessary for the heat-resistant sealing member to withstand high-temperature and high-concentration hydrogen sulfide gas generated in the vicinity of the oil field. Then, by blending a predetermined amount of two types of first and second carbon nanofibers with different thicknesses and uniformly dispersing them in a ternary fluorine-containing elastomer, high heat resistance is achieved. It is described that it can have and have excellent hydrogen sulfide resistance.

In Patent Document 5, as materials for constituting the swellable element provided in the packer, ethylene propylene diene rubber, ethylene propylene copolymer rubber, styrene butadiene rubber, natural rubber, ethylene propylene monomer rubber, ethylene vinyl acetate rubber, hydrogenated Examples include acrylonitrile butadiene rubber, acrylonitrile butadiene rubber, isoprene rubber, chloroprene rubber, polynorbornene, nitrile, VITON (registered trademark) fluoroelastomer, AFLAS (registered trademark) fluoropolymer, and KALREZ (registered trademark) perfluoroelastomer.

Patent Documents 6 and 7 include nitrile butadiene rubber, hydrogenation as a suitable material for constructing a packer element included in a repositionable rotating set / unset packer assembly (RPA) or pressure relief assist packer (PRP). Nitrile butadiene rubber, ethylene propylene diene rubber, fluoroelastomer, perfluoroelastomer, fluoropolymer elastomer, polytetrafluoroethylene, copolymer of tetrafluoroethylene and propylene, polyetheretherketone, polyetherketone, polyimideimide, polyimide, polyphenylene Sulfide and combinations thereof are illustrated.

International Publication No. 2014/084082 Special table 2012-519221 gazette Special table 2013-536308 gazette JP 2014-109020 A US Patent Application Publication No. 2014/0182862 US Patent Application Publication No. 2014/0238700 US Patent Application Publication No. 2014/0116699

As described above, tetrafluoroethylene / propylene copolymers, ternary fluorine-containing elastomers containing vinylidene fluoride units as materials constituting fluoroelastomer parts for use in exploration, drilling or production of oil or gas, Alternatively, perfluoroelastomers have been used.

However, a ternary fluorine-containing elastomer containing a tetrafluoroethylene / propylene copolymer or a vinylidene fluoride unit does not have sufficient amine resistance, oil resistance and low temperature resistance. Perfluoroelastomers are excellent in amine resistance, oil resistance and low temperature resistance, but are expensive. Since parts of equipment used in oil and gas fields are often thick and large, it is preferable that the material constituting the part is inexpensive.

An object of the present invention is to provide a fluoropolymer component that is excellent in amine resistance, oil resistance, and low temperature resistance and is inexpensive in view of the above situation.

As a result of intensive studies, the present inventors have found that a fluoropolymer containing a specific monomer is excellent in all properties, and has completed the present invention.

That is, the present invention relates to a fluoropolymer part for use in exploration, drilling or production of oil or gas, and a crosslinkable composition comprising a fluoropolymer having a glass transition temperature of 25 ° C. or less and a crosslinking agent. The fluorine-containing polymer obtained by crosslinking is vinylidene fluoride and the following general formula (1):
CH ₂ = CFRf (1)
(Wherein Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms), and is a copolymer comprising a fluorine-containing monomer (1) It is a part.

The copolymer comprises only vinylidene fluoride and a fluorine-containing monomer (1), and a copolymer having a vinylidene fluoride unit / fluorine monomer (1) molar ratio of 87/13 to 22/78. Containing only polymer (I), vinylidene fluoride, fluorine-containing monomer (1), and other monomers copolymerizable with vinylidene fluoride and fluorine-containing monomer (1), vinylidene fluoride Copolymer (II) in which the molar ratio of unit / fluorinated monomer (1) unit is 85/15 to 20/80 and the other monomer units are 1 to 50 mol% of the total monomer units ), Vinylidene fluoride, fluorine-containing monomer (1), and other monomers copolymerizable with vinylidene fluoride and fluorine-containing monomer (1). Fluorine monomer (1 The molar ratio of the units is 85/15 to 20/80, the other monomer units are 0 to 50 mol% of the total monomer units, and have at least one of iodine atom and bromine atom, It is preferable that it is at least one selected from the group consisting of copolymer (III) whose total amount is 0.001 to 10% by weight.

The copolymer is composed of vinylidene fluoride, fluorine-containing monomer (1), and other monomers copolymerizable with vinylidene fluoride and fluorine-containing monomer (1), and is a vinylidene fluoride unit. The molar ratio of the fluorine-containing monomer (1) unit is 85/15 to 20/80, the other monomer units are 0 to 50 mol% of the total monomer units, and iodine atom and bromine atom It is preferable that it is a copolymer (III) which has at least one of these and whose sum total is 0.001 to 10 weight%.

The present invention is a method for preventing or reducing the hardening or swelling of fluoropolymer parts used in exploration, drilling or production of oil or gas, comprising a fluoropolymer having a glass transition temperature of 25 ° C. or less and a crosslinking agent. Including the step of producing the fluoropolymer part by crosslinking the crosslinkable composition, wherein the fluoropolymer comprises vinylidene fluoride and the following general formula (1):
CH ₂ = CFRf (1)
(In the formula, Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms.) is there.

Since the fluoropolymer component of the present invention has the above-described configuration, it is excellent in amine resistance, oil resistance and low temperature resistance, and is inexpensive.

Since the method of the present invention has the above-described configuration, it is possible to prevent or reduce hardening or swelling of a fluoropolymer component used in oil exploration, drilling or production.

Hereinafter, the present invention will be specifically described.

The fluoropolymer component of the present invention can be suitably used in oil field applications or gas field applications. The fluoropolymer component of the present invention is also preferably used as a fluoropolymer component for use in oil, gas exploration, drilling or production. The gas may be a natural gas such as petroleum gas or shale gas. Natural gas may be embedded as natural gas hydrate.

Examples of the fluoropolymer component of the present invention include various sealing materials used in oil or gas mining, mud pump motor lining, gate valve sealing elements, electric boots, perforation guns, packers, and the like. Examples of electric boots include boots for electric connectors used in oil wells.

More specifically, as a fluoropolymer part of the present invention, a drill bit seal, a pressure adjusting diaphragm, a seal of a horizontal excavation motor (stator), a stator bearing (shaft) seal, a seal material used for a blow-off prevention device (BOP), Sealing materials used for rotary blowout prevention devices (pipe wipers), sealing materials used for MWD (real-time drilling information detection system), gas-liquid connectors, and logging tool seals used for logging devices (logging equipment) (for example, , O-rings, seals, packing, gas-liquid connectors, boots, etc.), expansion packers and completion packers, packer seals used in them, sealers used in cementing devices, packings, and perforators (perforators) Seal, mud pump Used seals, packings, motor linings, underground detector covers, U cups, composition seating cups, rotary seals, laminated elastomeric bearings, flow control seals, sand control seals, safety valve seals, hydraulic fracturing devices (Fracturing equipment) seals, linear packer and linear hanger seals and packing, wellhead seals and packing, choke and valve seals and packing, LWD (logging during logging), oil exploration and oil drilling Diaphragms used in applications (for example, diaphragms for supplying lubricating oil such as oil drilling pits), gate valves, electronic boots, drill gun seal elements, and the like.

The fluorine-containing polymer is vinylidene fluoride and the following general formula (1):
CH ₂ = CFRf (1)
(In the formula, Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms.)
It is a copolymer which consists of a fluorine-containing monomer (1) represented by these.

The said copolymer shows a very low glass transition temperature by having the said specific structure. Moreover, the fluorine-containing polymer containing the fluorine-containing monomer (1) unit represented by the general formula (1) is difficult to dehydrofluoride and has excellent amine resistance, oil resistance, and low temperature resistance. In addition, it has a fast vulcanization speed and good workability. In addition, since it has excellent steam resistance, it is particularly suitable for fluoropolymer parts for use in exploration, drilling or production of oil or gas. The fluorine-containing polymer is preferably a fluorine-containing elastomer, and is preferably an amorphous polymer.

The copolymer has a glass transition temperature of 25 ° C. or lower. Moreover, it can also be 0 degreeC or less. The glass transition temperature is preferably −5 ° C. or lower, and more preferably −10 ° C. or lower. Further, it can be set to -20 ° C or lower. Since the copolymer exhibits a very low glass transition temperature as described above, it is excellent in low temperature characteristics (cold resistance).
The glass transition temperature was obtained by using a differential scanning calorimeter (X-DSC823e, manufactured by Hitachi Technoscience Co., Ltd.) and cooling the sample to −75 ° C., and then heating the sample 10 mg at 20 ° C./min to obtain a DSC curve. The temperature indicating the intersection of the extension of the baseline before and after the second order transition of the DSC curve and the tangent at the inflection point of the DSC curve was defined as the glass transition temperature.

The fluorine-containing monomer (1) represented by the above general formula (1) is a simple compound in which Rf is a linear fluoroalkyl group because it is excellent in amine resistance, oil resistance and low-temperature resistance and is inexpensive. A monomer is preferable, and a monomer in which Rf is a linear perfluoroalkyl group is more preferable. Rf preferably has 1 to 6 carbon atoms.
As the fluorine-containing monomer (1) represented by the general formula (1), CH ₂ = CFCF ₃ , CH ₂ = CFCF ₂ CF ₃ , CH ₂ = CFCF ₂ CF ₂ CF ₃ , CH ₂ = CFCF ₂ Examples thereof include CF ₂ CF ₂ CF ₃ , among which 2,3,3,3-tetrafluoropropene represented by CH ₂ ═CFCF ₃ is preferable.

The copolymer may further comprise a monomer other than vinylidene fluoride and the fluorine-containing monomer (1) represented by the formula (1).
The other monomer is not particularly limited as long as it is a monomer copolymerizable with vinylidene fluoride and the fluorine-containing monomer (1) represented by the formula (1), one type or two or more types Monomers may be used.

The other monomers include tetrafluoroethylene [TFE], hexafluoropropylene, perfluoro (methyl vinyl ether), perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether), chlorotrifluoroethylene, trifluoroethylene, hexa It is preferably at least one selected from the group consisting of fluoroisobutene, vinyl fluoride, ethylene, propylene, alkyl vinyl ether, and a monomer that gives a cross-linking site. TFE, hexafluoropropylene, perfluoro (methyl vinyl ether) ), Perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether), chlorotrifluoroethylene, trifluoroethylene, hexafluoroisobutene, vinyl fluoride, ethylene Alkyl vinyl ether, and, more preferably at least one selected from the group consisting of monomer giving a crosslinking site. More preferred is TFE. It is also a preferable form that only TFE is used.

In the copolymer, examples of the monomer that gives the crosslinking site include, for example, the general formula:
CX ¹ ₂ = CX ¹ -Rf ¹ CHR ¹ X ²
Wherein X ¹ is a hydrogen atom, a fluorine atom or —CH ₃ , Rf ¹ is a fluoroalkylene group, a perfluoroalkylene group, a fluoro (poly) oxyalkylene group or a perfluoro (poly) oxyalkylene group, R ¹ Is a hydrogen atom or —CH ₃ , X ² is an iodine atom or a bromine atom.) An iodine or bromine-containing monomer represented by the general formula:
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 3
(Wherein, m is an integer of 0 to 5, n is an integer of 1 to 3, and X ³ is a cyano group, a carboxyl group, an alkoxycarbonyl group, an iodine atom, or a bromine atom). Body, general formula:
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) m (CF (CF 3)) n -X 4
(Wherein, m is an integer of 0 to 5, n is an integer of 1 to 3, and X ⁴ is a cyano group, a carboxyl group, an alkoxycarbonyl group, an iodine atom, a bromine atom, or —CH ₂ OH). Monomers represented.

Among _{them, CF 2 = CFOCF 2 CF (} CF 3) OCF 2 CF 2 CN, CF 2 = CFOCF 2 CF (CF 3) OCF 2 CF 2 COOH, CF 2 = CFOCF 2 CF 2 CH 2 I, CF 2 = CFOCF _{2 CF (CF 3) OCF 2} CF 2 CH 2 I, CH 2 = CFCF 2 OCF (CF 3) CF 2 OCF (CF 3) CN, CH 2 = CFCF 2 OCF (CF 3) CF 2 OCF (CF 3) It is preferably at least one selected from the group consisting of COOH and CH ₂ ═CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) CH ₂ OH.
As the monomer that gives the crosslinking site, CF ₂ = CFOCF ₂ CF ₂ CH ₂ I can improve the crosslinking density and improve the compression set in the crosslinking using peroxide. Particularly preferred.
In addition, in the copolymer (III) to be described later, monomers exemplified as monomers that give a crosslinking site can also be suitably used.

In the copolymer, the molar ratio of the vinylidene fluoride unit / the fluorine-containing monomer (1) unit represented by the formula (1) is preferably 87/13 to 20/80. The molar ratio of vinylidene fluoride unit / fluorinated monomer (1) unit represented by formula (1) is preferably 22/78 or more, more preferably 50/50 or more, and 60 / More preferably, it is 40 or more.
Moreover, it is preferable that another monomer unit is 0-50 mol% of all the monomer units, and it is more preferable that it is 1-40 mol%.

The copolymer is preferably a copolymer consisting only of vinylidene fluoride, the fluorine-containing monomer (1) represented by the general formula (1), and other monomers.

The copolymer may have at least one of an iodine atom and a bromine atom. In that case, the total content of iodine atoms and bromine atoms is preferably 0.001 to 10% by weight.

Since it is excellent in amine resistance, oil resistance and low temperature resistance and is inexpensive, the above copolymer consists only of vinylidene fluoride and fluorine-containing monomer (1), and vinylidene fluoride units / fluorine-containing single amount. Copolymer (I) having a molar ratio of the unit (1) unit of 87/13 to 22/78, vinylidene fluoride, fluorine-containing monomer (1), vinylidene fluoride and fluorine-containing monomer ( 1) It consists only of other monomers copolymerizable with the vinylidene fluoride unit / fluorine-containing monomer (1) unit molar ratio is 85/15 to 20/80, and other monomer units (II), vinylidene fluoride, fluorine-containing monomer (1), and vinylidene fluoride and fluorine-containing monomer (1) Other copolymerizable with It consists of monomers, the molar ratio of vinylidene fluoride units / fluorinated monomer (1) units is 85/15 to 20/80, and other monomer units are 0 to 50 of all monomer units. It is at least one selected from the group consisting of a copolymer (III) that is at least one of an iodine atom and a bromine atom and has a total content of 0.001 to 10% by weight. Preferably there is.

The copolymer (I) comprises only vinylidene fluoride and a fluorine-containing monomer (1) represented by the formula (1), and includes a vinylidene fluoride unit / a fluorine-containing monomer represented by the formula (1). The molar ratio of the body (1) unit is 87/13 to 22/78.
Since the copolymer (I) is excellent in amine resistance, oil resistance and low temperature resistance and is inexpensive, the copolymer (I) is a vinylidene fluoride unit / a fluorine-containing monomer (1) unit represented by the formula (1) The molar ratio is preferably 82/18 to 60/40.

The copolymer (II) includes a vinylidene fluoride, a fluorine-containing monomer (1) represented by the formula (1), and a vinylidene fluoride and a fluorine-containing monomer represented by the formula (1) ( 1) a copolymer composed only of other monomers copolymerizable with vinylidene fluoride unit / fluorine-containing monomer (1) unit represented by formula (1) in a molar ratio of 85/15 -20/80, and other monomer units are 1-50 mol% of all monomer units.
Since the copolymer (II) is excellent in amine resistance, oil resistance and low temperature resistance and is inexpensive, the copolymer (II) is a fluorine-containing monomer (1) unit represented by the vinylidene fluoride unit / formula (1). Is preferably 85/15 to 50/50. More preferably, it is 85 / 15-60 / 40.

Since the copolymer (II) is excellent in amine resistance, oil resistance and low temperature resistance, and is inexpensive, the other monomer units may be 1 to 40 mol% of the total monomer units. preferable. As other monomers, those described above are suitable.

The copolymer (III) is vinylidene fluoride, the following general formula (1):
CH ₂ = CFRf (1)
(Wherein Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms), vinylidene fluoride, and the above-mentioned fluorine-containing monomer ( 1) a copolymer comprising other monomers copolymerizable with vinylidene fluoride units / fluorine-containing monomer (1) units in a molar ratio of 85/15 to 20/80, The monomer unit is 0 to 50 mol% of the total monomer units, the glass transition temperature is 25 ° C. or lower, has at least one of iodine atom and bromine atom, and the total content thereof is 0.001. -10% by weight.

The copolymer (III) includes vinylidene fluoride and the following general formula (1):
CH ₂ = CFRf (1)
(Wherein Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms), or a copolymer comprising only the fluorine-containing monomer (1), or vinylidene fluoride, General formula (1):
CH ₂ = CFRf (1)
(Wherein Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms), vinylidene fluoride, and the above-mentioned fluorine-containing monomer ( It is preferably a copolymer consisting only of other monomers copolymerizable with 1).
In this case, the copolymer (III) is substantially composed of vinylidene fluoride and a copolymer composed only of the fluorine-containing monomer (1) represented by the formula (1), or substantially vinylidene fluoride. Ride, a copolymer comprising only the fluorine-containing monomer (1) represented by the formula (1), and the above-mentioned other monomers, but with a reactive emulsifier as long as the effects of the present invention are not impaired. It may be manufactured by using. Moreover, the I terminal etc. which originate in a chain transfer agent may be included.

The copolymer (III) includes vinylidene fluoride and the following general formula (1):
CH ₂ = CFRf (1)
(Wherein Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms) and is a copolymer consisting only of the fluorine-containing monomer (1), which is a vinylidene fluoride unit / The molar ratio of the fluorine-containing monomer (1) unit is more preferably 80/20 to 20/80.

The copolymer (III) has a molar ratio of vinylidene fluoride unit / fluorinated monomer (1) unit of 85/15 to 50/50, and other monomer units are all monomers. It is also preferable that it is 1-50 mol% of a unit.

The content of each monomer unit is a value measured by NMR method.

The copolymer (III) has at least one of an iodine atom and a bromine atom, and the total content thereof is 0.001 to 10% by weight. The total content of iodine atoms and bromine atoms is preferably 0.01 to 5% by weight, and more preferably 0.1 to 5% by weight. The iodine content was measured by mixing 12 mg of a sample (fluorinated polymer) with 5 mg of Na ₂ SO ₃ and 20 ml of pure water mixed with Na ₂ CO ₃ and K ₂ CO ₃ in a 1: 1 ratio (weight ratio). It is possible to measure using an Shimadzu 20A ion chromatograph after 30 mg of the absorbing solution dissolved in a quartz combustion flask, burned in oxygen and allowed to stand for 30 minutes. As the calibration curve, a KI standard solution, one containing 0.5 ppm of iodine ions or one containing 1.0 ppm can be used.

The bonding position of the iodine atom and bromine atom may be the terminal of the main chain or the terminal of the side chain of the copolymer (III), and may be both. In such a copolymer, the iodine terminal or bromine terminal serves as a crosslinking point (crosslinking site), and a crosslinked fluorine-containing polymer having a high crosslinking density can be obtained, and peroxide crosslinking can be performed more easily. become.

The copolymer (III) is produced by using an iodine or bromine-containing monomer as a monomer that gives a crosslinking site, using a bromine compound or an iodine compound as a polymerization initiator or a chain transfer agent, and the like. be able to.

In the copolymer (III), the other monomer is not particularly limited as long as it is a monomer copolymerizable with vinylidene fluoride and the fluorine-containing monomer (1) represented by the formula (1). 1 type or 2 or more types of monomers may be used.

In the copolymer (III), the other monomer is preferably 0 to 50 mol% of the total monomer units. More preferably, it is 1-50 mol%.

In the copolymer (III), examples of the monomer that gives a crosslinking site include, for example, the general formula:
CX ¹ ₂ = CX ¹ -Rf ¹ CHR ¹ X ²
Wherein X ¹ is a hydrogen atom, a fluorine atom or —CH ₃ , Rf ¹ is a fluoroalkylene group, a perfluoroalkylene group, a fluoro (poly) oxyalkylene group or a perfluoro (poly) oxyalkylene group, R ¹ Is a hydrogen atom or —CH ₃ , X ² is an iodine atom or a bromine atom.) An iodine or bromine-containing monomer represented by the general formula:
CX ¹ ₂ = CX ¹ -Rf ¹ X ²
(In the formula, X ¹ is a hydrogen atom, a fluorine atom or —CH ₃ , and Rf ¹ is a fluoroalkylene group, a perfluoroalkylene group, a fluoro (poly) oxyalkylene group or a perfluoro (poly) oxyalkylene group, X ² Is an iodine or bromine-containing monomer represented by the general formula: CH ₂ ═CH (CF ₂ ) _n I (n is an integer of 2 to 8). ) Iodine-containing monomer represented by the general formula:
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 3
(Wherein, m is an integer of 0 to 5, n is an integer of 1 to 3, and X ³ is a cyano group, a carboxyl group, an alkoxycarbonyl group, an iodine atom, or a bromine atom). Body, general formula:
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) m (CF (CF 3)) n -X 4
(Wherein, m is an integer of 0 to 5, n is an integer of 1 to 3, and X ⁴ is a cyano group, a carboxyl group, an alkoxycarbonyl group, an iodine atom, a bromine atom, or —CH ₂ OH). Monomer, general formula:
^{CR 2 R 3 = CR 4 -Z} -CR 5 = CR 6 R 7
(Wherein R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different and are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Z is linear or branched. An alkylene group having 1 to 18 carbon atoms, a cycloalkylene group having 3 to 18 carbon atoms, an alkylene or oxyalkylene group having 1 to 10 carbon atoms that is at least partially fluorinated Or
_{- (Q) p -CF 2 O-} (CF 2 CF 2 O) m (CF 2 O) n -CF 2 - (Q) p -
(Wherein Q is an alkylene or oxyalkylene group, p is 0 or 1, m / n is 0.2 to 5), and the molecular weight is 500 to 10,000 (per) fluoro. It is a polyoxyalkylene group. ) And the like.

General formula above:
^{CR 2 R 3 = CR 4 -Z} -CR 5 = CR 6 R 7
In The compound represented by, for _{example, CH 2 = CH- (CF 2} ) 2 -CH = CH 2, CH 2 = CH- (CF 2) 4 -CH = CH 2, CH 2 = CH- (CF 2 ₆ -CH = CH ₂ , the following formula:
^{_{CH 2 = CH-Z 1 -CH}} = CH 2
(In the formula, Z ¹ is a fluoropolyoxyalkylene group represented by —CH ₂ OCH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _m1 (CF ₂ O) _n1 —CF ₂ —CH ₂ OCH ₂ —). And m1 / n1 is 0.5 and the molecular weight is 2000.).

Examples of the monomer giving a crosslinking _{site, CF 2 = CFOCF 2 CF (} CF 3) OCF 2 CF 2 CN, CF 2 = CFOCF 2 CF (CF 3) OCF 2 CF 2 COOH, CF 2 = CFOCF 2 CF (CF _{3) OCF 2 CF 2 CH 2} I, CF 2 = CFOCF 2 CF 2 CH 2 I, CH 2 = CFCF 2 OCF (CF 3) CF 2 OCF (CF 3) CN, CH 2 = CFCF 2 OCF (CF 3) _{CF 2 OCF (CF 3) COOH} , CH 2 = CFCF 2 OCF (CF 3) CF 2 OCF (CF 3) CH 2 OH, _{and, CH 2 = CHCF 2 CF 2} I, CH 2 = CH (CF 2) 2 One of the preferred embodiments is at least one selected from the group consisting of CH═CH ₂ .
As the monomer that gives the crosslinking site, CF ₂ = CFOCF ₂ CF ₂ CH ₂ I can improve the crosslinking density and improve the compression set in the crosslinking using peroxide. Particularly preferred.

Examples of the monomer that gives a crosslinking site include, for example, the general formula:
CX ¹ ₂ = CX ¹ -Rf ¹ CHR ¹ X ²
Wherein X ¹ is a hydrogen atom, a fluorine atom or —CH ₃ , Rf ¹ is a fluoroalkylene group, a perfluoroalkylene group, a fluoropolyoxyalkylene group or a perfluoropolyoxyalkylene group, and R ¹ is a hydrogen atom Or —CH ₃ and X ² are an iodine atom or a bromine atom)
Iodine or bromine-containing monomer represented by the general formula:
CX ¹ ₂ = CX ¹ -Rf ¹ X ²
(Wherein X ¹ is a hydrogen atom, a fluorine atom or —CH ₃ , Rf ¹ is a fluoroalkylene group, a perfluoroalkylene group, a fluoropolyoxyalkylene group or a perfluoropolyoxyalkylene group, and X ² is an iodine atom. Or a bromine atom)
An iodine- or bromine-containing monomer represented by (preferably an iodine-containing monomer represented by CH ₂ ═CH (CF ₂ ) _n I (n is an integer of 2 to 8)), a general formula:
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 5
(In the formula, m is an integer of 0 to 5, n is an integer of 1 to 3, and X ⁵ is an iodine atom or a bromine atom)
And a monomer represented by the general formula:
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) m (CF (CF 3)) n -X 5
(In the formula, m is an integer of 0 to 5, n is an integer of 1 to 3, and X ⁵ is an iodine atom or a bromine atom)
It is also a preferred embodiment that the monomer is at least one monomer selected from the group consisting of: By using such an iodine or bromine-containing monomer as the other monomer, the copolymer (III) can also be produced.

In the copolymer (III), the monomer that gives a cross-linked site is preferably 0.01 to 10 mol%, more preferably 0.01 to 2 mol% of all monomer units.

The copolymer is more preferably copolymer (III) because it is excellent in amine resistance, oil resistance and low-temperature resistance and is inexpensive.

The copolymer preferably has a number average molecular weight (Mn) of 7,000 to 500,000, a weight average molecular weight (Mw) of preferably 10,000 to 1,000,000, and an Mw / Mn of 1 because of excellent sealing properties. .3 to 4.0 is preferable.
The number average molecular weight (Mn), the weight average molecular weight (Mw), and Mw / Mn are values measured by the GPC method.

The copolymer preferably has a Mooney viscosity (ML _{1 + 10} (100 ° C.)) at 100 ° C. of 2 or more, more preferably 5 or more, from the viewpoint of good moldability. Similarly, it is preferably 200 or less, more preferably 150 or less, and even more preferably 100 or less, from the viewpoint of good moldability. Mooney viscosity is a value measured according to ASTM-D1646 and JIS K6300.

The copolymer can be produced by a general radical polymerization method. The polymerization form may be any of bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, but is preferably emulsion polymerization because it is industrially easy to implement.

In the above polymerization, a polymerization initiator, a chain transfer agent, a surfactant, and a solvent can be used, and conventionally known ones can be used.

In the polymerization of the copolymer, an oil-soluble radical polymerization initiator or a water-soluble radical initiator can be used as a polymerization initiator.

The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, for example, dialkyl peroxycarbonates such as diisopropyl peroxydicarbonate and disec-butylperoxydicarbonate, t-butylperoxy Peroxyesters such as isobutyrate and t-butyl peroxypivalate, dialkyl peroxides such as di-t-butyl peroxide, and di (ω-hydro-dodecafluoroheptanoyl) peroxide, di (Ω-hydro-tetradecafluoroheptanoyl) peroxide, di (ω-hydro-hexadecafluorononanoyl) peroxide, di (perfluorobutyryl) peroxide, di (perfluarparyl) peroxide, di (perfluoro) Hexanoyl) Oxide, di (perfluoroheptanoyl) peroxide, di (perfluorooctanoyl) peroxide, di (perfluorononanoyl) peroxide, di (ω-chloro-hexafluorobutyryl) peroxide, di (ω- Chloro-decafluorohexanoyl) peroxide, di (ω-chloro-tetradecafluorooctanoyl) peroxide, ω-hydro-dodecafluoroheptanoyl-ω-hydrohexadecafluorononanoyl-peroxide, ω-chloro- Hexafluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydrododecafluoroheptanoyl-perfluorobutyryl-peroxide, di (dichloropentafluorobutanoyl) peroxide, di (trichlorooctaf Olohexanoyl) peroxide, di (tetrachloroundecafluorooctanoyl) peroxide, di (pentachlorotetradecafluorodecanoyl) peroxide, di (undecachlorodotriacontafluorodocosanoyl) peroxide di [perfluoro ( Or fluorochloro) acyl] peroxides.

The water-soluble radical polymerization initiator may be a known water-soluble peroxide, for example, ammonium salts such as persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, percarbonate, potassium salts, sodium salts. , T-butyl permaleate, t-butyl hydroperoxide and the like. A reducing agent such as sulfites and sulfites may also be included, and the amount used may be 0.1 to 20 times that of the peroxide.

The addition amount of the radical polymerization initiator is not particularly limited, but an amount that does not significantly reduce the polymerization rate (for example, several ppm to water concentration) or more in the initial stage of polymerization, sequentially, or continuously. And then add. The upper limit is a range in which the heat of polymerization reaction can be removed from the surface of the apparatus.

As the surfactant, a nonionic surfactant, an anionic surfactant, a cationic surfactant or the like can be used, and a straight chain having 4 to 20 carbon atoms such as ammonium perfluorooctanoate or ammonium perfluorohexanoate. Or the branched fluorine-containing anionic surfactant is preferable. The addition amount (with respect to polymerization water) is preferably 10 to 5000 ppm. More preferably, it is 50-5000 ppm.
Moreover, a reactive emulsifier can be used as a surfactant. The reactive emulsifier is not particularly limited as long as it is a compound having at least one unsaturated bond and one or more hydrophilic groups. For example, CH ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH ₄ , CH _{2 = CFCF 2 CF (CF 3} ) OCF 2 CF 2 COONH 4, CF 2 = CFOCF 2 CF (CF 3) OCF (CF 3) COONH 4 and the like. The addition amount (with respect to polymerization water) is preferably 10 to 5000 ppm. More preferably, it is 50-5000 ppm.

As the solvent, a solvent having no chain transfer property is preferable. In the case of solution polymerization, dichloropentafluoropropane (R-225) is exemplified. In the case of emulsion polymerization and suspension polymerization, water, a mixture of water and a water-soluble organic solvent, or water and a water-insoluble organic solvent. A mixture.

In the polymerization of the copolymers (I) and (II), examples of the chain transfer agent include esters such as dimethyl malonate, diethyl malonate, methyl acetate, ethyl acetate, butyl acetate, dimethyl succinate, Examples include isopentane, methane, ethane, propane, isopropanol, acetone, various mercaptans, carbon tetrachloride, and cyclohexane.

A bromine compound or iodine compound may be used as the chain transfer agent. Examples of the polymerization method using a bromine compound or iodine compound include a method in which emulsion polymerization is carried out in an aqueous medium under pressure in the presence of a bromine compound or iodine compound in a substantially oxygen-free state. (Iodine transfer polymerization method). Representative examples of bromine compounds or iodine compounds to be used include, for example, the general formula:
R ² I _x Br _y
(Wherein x and y are each an integer of 0 to 2 and satisfy 1 ≦ x + y ≦ 2, and R ² is a saturated or unsaturated fluorohydrocarbon group having 1 to 16 carbon atoms or chlorofluoro A hydrocarbon group or a hydrocarbon group having 1 to 3 carbon atoms which may contain an oxygen atom). By using a bromine compound or an iodine compound, iodine or bromine is introduced into the polymer and functions as a crosslinking point.

Examples of the iodine compound include 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3-diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5- Diiodo-2,4-dichloroperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane , diiodomethane, 1,2-diiodoethane, 1,3-diiodo -n- _{propane, 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 CFBrO F _3, 1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo -4-iodoperfluorobutene-1, 2-bromo-4-iodoperfluorobutene-1, monoiodomonobromo and diiodomonobromo substituents of benzene, and (2-iodoethyl) and (2-bromoethyl) ) Substituents, etc., and these compounds may be used alone or in combination with each other.

Among these, 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, and 2-iodoperfluoropropane are used from the viewpoint of polymerization reactivity, crosslinking reactivity, availability, and the like. Is preferred.

In the polymerization of the copolymer (III), it is preferable to use a bromine compound or an iodine compound as a chain transfer agent. Examples of the polymerization method using a bromine compound or iodine compound include a method in which emulsion polymerization is carried out in an aqueous medium under pressure in the presence of a bromine compound or iodine compound in a substantially oxygen-free state. (Iodine transfer polymerization method). Representative examples of bromine compounds or iodine compounds to be used include, for example, the general formula:
R ² I _x Br _y
(Wherein x and y are each an integer of 0 to 2 and satisfy 1 ≦ x + y ≦ 2, and R ² is a saturated or unsaturated fluorohydrocarbon group having 1 to 16 carbon atoms or chlorofluoro A hydrocarbon group or a hydrocarbon group having 1 to 3 carbon atoms which may contain an oxygen atom). By using a bromine compound or an iodine compound, iodine or bromine is introduced into the polymer and functions as a crosslinking point.

Examples of the iodine compound include 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3-diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5- Diiodo-2,4-dichloroperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane , diiodomethane, 1,2-diiodoethane, 1,3-diiodo -n- _{propane, 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 CFBrO F _3, 1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo -4-iodoperfluorobutene-1, 2-bromo-4-iodoperfluorobutene-1, monoiodomonobromo and diiodomonobromo substituents of benzene, and (2-iodoethyl) and (2-bromoethyl) ) Substituents, etc., and these compounds may be used alone or in combination with each other.
Among these, 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, and 2-iodoperfluoropropane are used from the viewpoint of polymerization reactivity, crosslinking reactivity, availability, and the like. Is preferred.

In the polymerization of the copolymer (III), examples of the chain transfer agent include esters such as dimethyl malonate, diethyl malonate, methyl acetate, ethyl acetate, butyl acetate, dimethyl succinate, isopentane, methane, Ethane, propane, isopropanol, acetone, various mercaptans, carbon tetrachloride, cyclohexane and the like can also be used.

In the polymerization of the copolymer, the polymerization temperature, polymerization pressure and polymerization time vary depending on the type of the solvent and polymerization initiator, but may be -15 to 150 ° C, atmospheric pressure to 6.5 MPa, 1 to 24 hours. . In particular, when an oil-soluble radical polymerization initiator containing a fluorine atom is used as a polymerization initiator in solution polymerization, the polymerization temperature is preferably −15 to 50 ° C., more preferably 10 to 35 ° C. In the case of using an oil-soluble radical polymerization initiator containing a fluorine atom in emulsion polymerization and suspension polymerization, the polymerization temperature is preferably 30 to 95 ° C. When a water-soluble radical polymerization initiator is used as the polymerization initiator, the polymerization temperature is preferably 0 to 100 ° C, and more preferably 10 to 95 ° C.
The polymerization pressure is preferably 1.0 MPa or more, more preferably 2.0 MPa or more, because the value of compression set of the fluoropolymer component becomes good, and the polymerization rate increases and productivity is improved. 0.0 MPa or more is more preferable, and 4.5 MPa or more is most preferable.

The copolymer may be in any form such as an aqueous dispersion or powder.
In the case of emulsion polymerization, the copolymer powder can be obtained by coagulating a dispersion after polymerization, washing with water, dehydrating, and drying. The coagulation can be performed by adding an inorganic salt such as aluminum sulfate or an inorganic acid, applying a mechanical shear force, or freezing the dispersion. In the case of suspension polymerization, it can be obtained by recovering from the dispersion after polymerization and drying. In the case of solution polymerization, it can be obtained by drying a solution containing a fluorine-containing polymer as it is, or can be obtained by purifying by adding a poor solvent dropwise.

As said copolymer, 1 type may be used and 2 or more types may be used. In particular, two types of copolymers having different molecular structures may be used in combination.
As a form using together two kinds of copolymers having different molecular structures, a form using two kinds of copolymers (I) having different molecular structures, a form using two kinds of copolymers (II) having different molecular structures, Form using two kinds of copolymers (III) having different molecular structures, form using one kind of copolymer (I) and one kind of copolymer (II), and one kind of copolymer (I) The form which uses together 1 type of copolymer (III), the form which uses together 1 type of copolymer (II), and 1 type of copolymer (III) are mentioned.

As described above, when two types of fluorine-containing polymers are used in combination as the copolymer, it is preferable that one type is a branched type fluorine-containing polymer and the other type is a linear type fluorine-containing polymer. More preferably, one type described in International Publication No. 2009/119409 has a crosslinking site capable of peroxide crosslinking (A), and the number average molecular weight is in the range of 1,000 to 300,000. A branched fluorine-containing polymer having a Mark-Houwint gradient a of less than 0.6 when the absolute weight molecular weight and the intrinsic viscosity are plotted on a Mark-Houwint plot where the horizontal axis is the absolute weight molecular weight and the vertical axis is the intrinsic viscosity. And the other is (B) a mark having a number average molecular weight in the range of 1,000 to 250,000, an absolute weight molecular weight and an intrinsic viscosity, the horizontal axis representing the absolute weight molecular weight and the vertical axis representing the intrinsic viscosity— A form that is a linear fluorine-containing polymer having a Mark-Hawin gradient a of 0.6 or more when plotted in a Howin plot, or one type is (A) small An ethylenically unsaturated compound containing Kutomo one fluoroolefin represented by the general formula:
CY ¹ ₂ = CY ² Rf ² X ²
(Wherein Y ¹ and Y ² are a fluorine atom, a hydrogen atom or —CH ₃ ; Rf ² may have an ether-bonded oxygen atom, and a hydrogen atom is partially or entirely substituted with a fluorine atom. When a copolymer represented by a chain or branched fluorine-containing alkylene group; X ² is an iodine atom or a bromine atom) is added, the compound represented by the above general formula is added after the polymerization initiator is added. A branched fluorine-containing polymer obtained by a production method characterized by starting at a time when 0 to 10% by mass of the total amount of ethylenically unsaturated compounds added is added. B) The number average molecular weight is in the range of 1,000 to 250,000, and the absolute weight molecular weight and intrinsic viscosity are plotted in a Mark-Houwin plot where the horizontal axis is the absolute weight molecular weight and the vertical axis is the intrinsic viscosity. In this case, the linear fluorine-containing polymer has a Mark-Howin gradient a of 0.6 or more.
Thus, as a fluorine-containing polymer in the present invention, one type is a copolymer (II) or a copolymer (III), has a crosslinking site capable of peroxide crosslinking, and has a number average molecular weight of 1, When the absolute weight molecular weight and the intrinsic viscosity are plotted on a Mark-Houwin plot in which the abscissa is the absolute weight molecular weight and the ordinate is the intrinsic viscosity, the mark-Hawin gradient a is 0.000 to 300,000. An ethylenically unsaturated compound that is a branched fluoropolymer that is less than 6 or that contains at least one fluoroolefin, and a general formula:
CY ¹ ₂ = CY ² Rf ² X ²
(Wherein Y ¹ and Y ² are a fluorine atom, a hydrogen atom or —CH ₃ ; Rf ² may have an ether-bonded oxygen atom, and a hydrogen atom is partially or entirely substituted with a fluorine atom. When a copolymer represented by a chain or branched fluorine-containing alkylene group; X ² is an iodine atom or a bromine atom) is added, the compound represented by the above general formula is added after the polymerization initiator is added. A branched fluorine-containing polymer obtained by a production method starting at a time when 0 to 10% by mass of the total amount of the ethylenically unsaturated compound added is added. A polymer (I), a copolymer (II) or a copolymer (III), wherein the number average molecular weight is in the range of 1,000 to 250,000, and the absolute weight molecular weight and intrinsic viscosity are plotted on the horizontal axis. Absolute weight molecular weight A preferred embodiment is a linear fluoropolymer having a Mark-Houwint gradient a of 0.6 or more when plotted on a Mark-Houwint plot where the vertical axis represents the intrinsic viscosity.

The fluoropolymer component of the present invention is obtained by crosslinking a crosslinkable composition containing the above-mentioned fluoropolymer and a crosslinking agent.
The fluoropolymer part of the present invention is preferably obtained by cross-linking and molding the cross-linkable composition. The fluoropolymer component of the present invention can be produced by molding the crosslinkable composition and crosslinking the resulting molded article, or can be produced by simultaneously performing molding and crosslinking.

The cross-linking may be appropriately determined depending on the type of cross-linking agent to be used, but is usually fired at a temperature of 150 to 300 ° C. for 1 minute to 24 hours. Moreover, it can bridge | crosslink under normal pressure, pressurization, pressure reduction, and also in the air.

The cross-linking method is not particularly limited, and a steam cross-linking method, a pressure forming method, a normal method in which a cross-linking reaction is started by heating can be adopted, and a radiation cross-linking method at normal temperature and normal pressure may be used.

After performing the first crosslinking treatment (referred to as primary crosslinking), a post-treatment step called secondary crosslinking may be performed.

The molding is not particularly limited, and examples thereof include compression molding, extrusion molding, transfer molding, and injection molding.

The crosslinkable composition contains the fluoropolymer and a crosslinking agent.
In the crosslinkable composition, the blending amount of the crosslinking agent is 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the fluoropolymer. If the crosslinking agent is less than 0.01 parts by mass, the degree of crosslinking is insufficient, so the performance of the fluoropolymer component tends to be impaired. If the amount exceeds 10 parts by mass, the crosslinking density becomes too high and the crosslinking time is long. In addition, it is economically undesirable.

The crosslinking agent is not particularly limited as long as it is a crosslinking agent usually used in polyamine crosslinking, polyol crosslinking, and peroxide crosslinking, but at least one selected from the group consisting of polyamine compounds, polyhydroxy compounds, and organic peroxides. Preferably it is a seed.

Examples of the polyamine compound include hexamethylenediamine carbamate, N, N′-dicinnamylidene-1,6-hexamethylenediamine, 4,4′-bis (aminocyclohexyl) methanecarbamate, and the like. Among these, N, N′-dicinnamylidene-1,6-hexamethylenediamine is preferable.

As the polyhydroxy compound, a polyhydroxy aromatic compound is preferably used from the viewpoint of excellent heat resistance.

The polyhydroxy aromatic compound is not particularly limited. For example, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A), 2,2-bis (4-hydroxyphenyl) perfluoropropane. (Hereinafter referred to as bisphenol AF), resorcin, 1,3-dihydroxybenzene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 4,4′-dihydroxydiphenyl, 4,4 ′ -Dihydroxystilbene, 2,6-dihydroxyanthracene, hydroquinone, catechol, 2,2-bis (4-hydroxyphenyl) butane (hereinafter referred to as bisphenol B), 4,4-bis (4-hydroxyphenyl) valeric acid, 2 , 2-Bis (4-hydroxyphenyl) Tetrafluorodichloropropane, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl ketone, tri (4-hydroxyphenyl) methane, 3,3 ′, 5,5′-tetrachlorobisphenol A, 3,3 Examples include ', 5,5'-tetrabromobisphenol A. These polyhydroxy aromatic compounds may be an alkali metal salt, an alkaline earth metal salt or the like, but when the copolymer is coagulated using an acid, it is preferable not to use the metal salt.

When the crosslinking agent is a polyhydroxy compound, the crosslinkable composition preferably contains a crosslinking accelerator. A crosslinking accelerator accelerates | stimulates the production | generation of the intramolecular double bond in the dehydrofluorination reaction of a fluorine-containing polymer principal chain, and the addition of the polyhydroxy compound to the produced | generated double bond.

Examples of the crosslinking accelerator include onium compounds. Among onium compounds, ammonium compounds such as quaternary ammonium salts, phosphonium compounds such as quaternary phosphonium salts, oxonium compounds, sulfonium compounds, cyclic amines, and 1 It is preferably at least one selected from the group consisting of functional amine compounds, and more preferably at least one selected from the group consisting of quaternary ammonium salts and quaternary phosphonium salts.

The quaternary ammonium salt is not particularly limited. For example, 8-methyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride, 8-methyl-1,8-diazabicyclo [5. 4.0] -7-undecenium iodide, 8-methyl-1,8-diazabicyclo [5.4.0] -7-undecenium hydroxide, 8-methyl-1,8-diazabicyclo [5]. 4.0] -7-undecenium methyl sulfate, 8-ethyl-1,8-diazabicyclo [5.4.0] -7-undecenium bromide, 8-propyl-1,8-diazabicyclo [5 4.0] -7-undecenium bromide, 8-dodecyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride, 8-dodecyl-1,8-diazabicyclo 5,4,0] -7-undecenium hydroxide, 8-eicosyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride, 8-tetracosyl-1,8-diazabicyclo [ 5.4.0] -7-undecenium chloride, 8-benzyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride (hereinafter referred to as DBU-B), 8-benzyl -1,8-diazabicyclo [5.4.0] -7-undecenium hydroxide, 8-phenethyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride, 8- ( 3-phenylpropyl) -1,8-diazabicyclo [5.4.0] -7-undecenium chloride and the like. Among these, DBU-B is preferable from the viewpoint of excellent crosslinkability and physical properties of the fluoropolymer part.

The quaternary phosphonium salt is not particularly limited. For example, tetrabutylphosphonium chloride, benzyltriphenylphosphonium chloride (hereinafter referred to as BTPPC), benzyltributylphosphonium chloride, benzyltributylphosphonium chloride, tributylallylphosphonium chloride, tributyl. -2-methoxypropylphosphonium chloride, benzylphenyl (dimethylamino) phosphonium chloride, and the like. Among these, benzyltriphenylphosphonium chloride (BTPPC) is preferred because of its excellent crosslinkability and physical properties of the fluoropolymer component. .

Further, as a crosslinking accelerator, a quaternary ammonium salt, a solid solution of a quaternary phosphonium salt and bisphenol AF, or a chlorine-free crosslinking accelerator disclosed in JP-A-11-147891 can also be used.

It is preferable that the compounding quantity of a crosslinking accelerator is 0.01-8 mass parts with respect to 100 mass parts of fluoropolymers, More preferably, it is 0.02-5 mass parts. When the crosslinking accelerator is less than 0.01 part by mass, the crosslinking of the fluoropolymer does not proceed sufficiently, and the heat resistance and oil resistance of the resulting fluoropolymer component tend to be reduced, exceeding 8 parts by mass. And there exists a tendency for the moldability of a crosslinkable composition to fall.

The organic peroxide may be an organic peroxide that can easily generate radicals in the presence of heat or a redox system. For example, 1,1-bis (t-butylperoxy) -3,5, 5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α-bis (t-butylperoxide Oxy) -p-diisopropylbenzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne-3 Benzoyl peroxide, t-butylperoxybenzene, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, t-butylperoxide -Oxybenzoate can be listed. Among these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and 2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne-3 are preferable.

When the crosslinking agent is an organic peroxide, the crosslinking composition preferably contains a crosslinking aid. Examples of the crosslinking aid include triallyl cyanurate, trimethallyl isocyanurate, triallyl isocyanurate (TAIC), triacryl formal, triallyl trimellitate, N, N′-m-phenylenebismaleimide, dipropargyl. Terephthalate, diallyl phthalate, tetraallyl terephthalate amide, triallyl phosphate, bismaleimide, fluorinated triallyl isocyanurate (1,3,5-tris (2,3,3-trifluoro-2-propenyl) -1,3, 5-triazine-2,4,6-trione), tris (diallylamine) -S-triazine, triallyl phosphite, N, N-diallylacrylamide, 1,6-divinyldodecafluorohexane, hexaallylphosphoramide, N , N, N ', N'-teto Allylphthalamide, N, N, N ′, N′-tetraallylmalonamide, trivinylisocyanurate, 2,4,6-trivinylmethyltrisiloxane, tri (5-norbornene-2-methylene) cyanurate, triallyl Examples include phosphite. Among these, triallyl isocyanurate (TAIC) is preferable from the viewpoint of excellent crosslinkability and physical properties of the fluoropolymer part.

The compounding quantity of a crosslinking adjuvant is 0.01-10 mass parts with respect to 100 mass parts of fluoropolymers, Preferably it is 0.1-5.0 mass parts. If the crosslinking aid is less than 0.01 parts by mass, the crosslinking time tends to be unpractical, and if it exceeds 10 parts by mass, the crosslinking time becomes too fast, and the fluoropolymer component is compressed. Permanent strain also tends to decrease.

Polyamine crosslinking using a polyamine compound as a crosslinking agent can be carried out in the same manner as before. For example, a method in which the above-mentioned fluorine-containing polymer and a crosslinking agent, if necessary, a crosslinking accelerator, and other additives that can be mixed as appropriate, are roll-kneaded, pressed into a mold and pressurized for primary crosslinking, followed by secondary crosslinking. Can be given. In general, the conditions for the primary crosslinking are adopted from the range of a temperature of 100 to 200 ° C., a time of 5 to 120 minutes, and a pressure of about 2 to 10 MPa, and the conditions of the secondary crosslinking are a temperature of 150 to 300 ° C. It is adopted from the time range.

Polyol crosslinking using a polyhydroxy compound as a crosslinking agent can be carried out in the same manner as before. For example, a method in which the above-mentioned fluorine-containing polymer and a crosslinking agent, if necessary, a crosslinking accelerator, and other additives that can be mixed as appropriate, are roll-kneaded, pressed into a mold and pressurized for primary crosslinking, followed by secondary crosslinking. Can be given. For the kneading, an internal mixer, a Banbury mixer or the like can be preferably used. In general, primary crosslinking can be performed at 2 to 10 MPa at 100 to 200 ° C. for 5 to 60 minutes, and secondary crosslinking can be performed at 150 to 300 ° C. for 30 minutes to 30 hours.

Peroxide crosslinking using an organic peroxide as a crosslinking agent can be carried out in the same manner as before. For example, a method in which the above-mentioned fluorine-containing polymer and a crosslinking agent, if necessary, a crosslinking accelerator, and other additives that can be mixed as appropriate, are roll-kneaded, pressed into a mold and pressurized for primary crosslinking, followed by secondary crosslinking. Can be given. In general, primary crosslinking can be performed at 2 to 10 MPa at 100 to 200 ° C. for 5 to 60 minutes, and secondary crosslinking can be performed at 150 to 300 ° C. for 30 minutes to 30 hours.

When the fluorine-containing polymer is copolymer (III), it has at least one of iodine atom and bromine atom, and the total content thereof is 0.001 to 10% by weight. It becomes a point (crosslinking site), and the crosslinking density can be further increased.

When the fluoropolymer is a copolymer (III), the crosslinkable composition more preferably contains an organic peroxide as a crosslinker.
The copolymer (III) has at least one of an iodine atom and a bromine atom, and the total content thereof is 0.001 to 10% by weight. Can be performed more easily. Examples of the organic peroxide include those described above, among which 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and 2,5-dimethyl-2,5-di (t- Preferably, it is at least one compound of (butylperoxy) -hexyne-3. The crosslinkable composition preferably contains a crosslinking aid, and examples of the crosslinking aid include those described above. Among them, triallyl isocyanurate (TAIC) is preferred because of its excellent crosslinkability and physical properties of the molded product. Is preferred.

When the fluoropolymer is a copolymer (III), the amount of the crosslinking aid in the crosslinkable composition is 0.01 to 10 parts by mass with respect to 100 parts by mass of the fluoropolymer, preferably 0.8. 1 to 5.0 parts by mass. If the crosslinking aid is less than 0.01 parts by mass, the crosslinking time tends to be unpractical, and if it exceeds 10 parts by mass, the crosslinking time becomes too fast, and the fluoropolymer component is compressed. Permanent strain also tends to decrease.

When the fluorine-containing polymer is the copolymer (III), the crosslinking conditions of the crosslinkable composition may be appropriately determined depending on the type of the crosslinking agent used, etc., but usually at a temperature of 150 to 300 ° C. for 1 minute to Bake for 24 hours. Moreover, it can bridge | crosslink under normal pressure, pressurization, pressure reduction, and also in the air.

When the fluoropolymer is a copolymer (III), the crosslinkable composition preferably contains an organic peroxide as a crosslinker and crosslinks by peroxide crosslinking. Peroxide crosslinking using an organic peroxide as a crosslinking agent can be carried out in the same manner as before. For example, copolymer (III) and a crosslinking agent, if necessary, a crosslinking accelerator, and other additives that can be mixed as appropriate are roll-kneaded and then put into a mold for pressurization and primary crosslinking, followed by secondary crosslinking. How to do. In general, primary crosslinking can be performed at 2 to 10 MPa at 100 to 200 ° C. for 5 to 60 minutes, and secondary crosslinking can be performed at 150 to 300 ° C. for 30 minutes to 30 hours.

The crosslinkable composition preferably also contains a filler. Fillers include metal oxides such as calcium oxide, titanium oxide, and aluminum oxide; metal hydroxides such as magnesium hydroxide, aluminum hydroxide, and calcium hydroxide; magnesium carbonate, aluminum carbonate, calcium carbonate, barium carbonate, etc. Carbonates; silicates such as magnesium silicate, calcium silicate, sodium silicate, and aluminum silicate; sulfates such as aluminum sulfate, calcium sulfate, and barium sulfate; synthetic hydrotalcite, molybdenum disulfide, iron sulfide, sulfide Metal sulfides such as copper; diatomaceous earth, asbestos, lithopone (zinc sulfide / barium sulfide), graphite, carbon black, carbon fluoride, calcium fluoride, coke, quartz fine powder, zinc white, talc, mica powder, wax Lastite, carbon fiber, aramid fiber Various whiskers, glass fiber, organic reinforcing agents, organic fillers, polytetrafluoroethylene, mica, silica, Celite, clay and the like.

The crosslinkable composition preferably contains a plasticizer. Examples of the plasticizer include dioctyl phthalic acid and pentaerythritol.

The crosslinkable composition also preferably contains a processing aid. Examples of the processing aid include higher fatty acids such as stearic acid, oleic acid, palmitic acid, and lauric acid; higher fatty acid salts such as sodium stearate and zinc stearate; Higher fatty acid amides such as stearic acid amide and oleic acid amide; Higher fatty acid esters such as ethyl oleate; Higher aliphatic amines such as stearylamine and oleylamine; Petroleum waxes such as carnauba wax and ceresin wax; Ethylene glycol, glycerin and diethylene glycol Polyglycols such as: aliphatic hydrocarbons such as petrolatum, paraffin; silicone oils, silicone polymers, low molecular weight polyethylene, phthalates, phosphates, rosin, (halogenated) dialkylamines, Surface active agents, sulfone compounds, fluorine-based aids, and the like.

The crosslinkable composition is an acid acceptor, release agent, pigment, flame retardant, lubricant, light stabilizer, weathering stabilizer, antistatic agent, ultraviolet absorber, antioxidant, foaming agent, perfume, oil, softening An agent or the like may be included within a range that does not affect the effects of the present invention.

The crosslinkable composition may contain a solvent. When the fluorine-containing polymer is dissolved in a solvent, it can be used as a paint. Examples of the solvent include ketone solvents and ester solvents.

The crosslinkable composition may contain another polymer different from the fluorine-containing polymer. Examples of the other polymer include nitrile rubber, acrylic rubber, epichlorohydrin rubber, fluorosilicone rubber, silicone rubber, fluorine-containing thermoplastic elastomer, and polyvinylidene fluoride.

The crosslinkable composition is preferably obtained by kneading at least the fluorine-containing polymer, the crosslinking agent, and the above-described crosslinking accelerator, if desired.

For the kneading, an open roll, a Banbury mixer, a pressure kneader, an extruder or the like can be used, but an extruder such as a pressure kneader or a twin screw extruder can be used in that a high shear force can be applied. preferable.

The fluoropolymer component of the present invention is excellent in low temperature resistance and hard to cure even at low temperatures. Moreover, the fluoropolymer component of the present invention is excellent in oil resistance and amine resistance, and hardly swells.

That is, the present invention is a method for preventing or reducing the hardening or swelling of a fluoropolymer part used in exploration, drilling or production of oil or gas, and a fluoropolymer having a glass transition temperature of 25 ° C. or less and a crosslinking agent. And the step of producing the fluoropolymer part by crosslinking a crosslinkable composition comprising: a vinylidene fluoride and the following general formula (1):
CH ₂ = CFRf (1)
(In the formula, Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms.) is there.

Next, the present invention will be described with reference to examples, but the present invention is not limited to such examples.

Each numerical value of the examples was measured by the following method.

[Copolymer composition]
Measured by NMR method.
Measuring device: VNMRS400 manufactured by Varian
Resonance frequency: 376.04 (Sfrq)
Pulse wave: 30 ° (pw = 6.8)

[Glass transition temperature (Tg)]
Using a differential scanning calorimeter (manufactured by Hitachi Technoscience, X-DSC823e), after cooling to −75 ° C., a 10 mg sample was heated at 20 ° C./min to obtain a DSC curve. The glass transition temperature was defined as the temperature indicating the intersection of the base line extension before and after the transition and the tangent at the inflection point of the DSC curve.

[Iodine content measurement]
Samples (resulting polymer) 12 mg to mix 5mg of _Na 2 SO _3, the absorbing liquid obtained by dissolving 30mg of a mixture of pure water 20ml to _Na 2 CO ₃ and _K 2 CO ₃ and 1: 1 (by weight) Used, burned in oxygen in a quartz flask, allowed to stand for 30 minutes, and then measured using a Shimadzu 20A ion chromatograph. The calibration curve was measured using a KI standard solution, one containing 0.5 ppm iodine ion and one containing 1.0 ppm.

Crosslinking characteristics Measure the minimum torque (ML), maximum torque (MH), induction time (T10) and optimum vulcanization time (T90) with a curast meter type II (manufactured by JSR Corporation) according to JIS K6300-2. did.

100% Modulus (M100)
It measured according to JIS K6251.

Tensile strength at break (Tb)
It measured according to JIS K6251.

Tensile elongation at break (Eb)
It measured according to JIS K6251.

Hardness (Hs [Shore A, peak])
It was measured with a durometer type A according to JIS K6253 (peak value and after 1 s).

Specific density was determined by measuring the density according to JIS K6268.

Oil Resistance Test An immersion test was performed at 150 ° C. for 168 hours using ASTM SF-105G oil. 100% modulus after immersion test (M100), tensile strength at break (Tb), tensile elongation at break (Eb), hardness (Hs [Shore A, peak]), volume swell ratio (ΔV), values before immersion The rate of change with respect to was calculated. ΔV is the rate of change of volume after the sample piece is immersed under a predetermined condition (representing the degree of swelling). When the original volume of the sample piece is Vo and the volume after the test is V, ΔV = It is represented by (V−Vo) / Vo × 100. The volume is calculated from the weight in air and the weight in water.

Fuel oil test (oil resistance test)
60 ° C. in Fuel C (isooctane / toluene = 50/50 vol%), CE10 (isooctane / toluene / ethanol = 45/45/10 vol%) or CE20 (isooctane / toluene / ethanol = 40/40/20 vol%) X The volume change rate when immersed for 70 hours was measured.

Amine resistance test An immersion test was conducted at 125 ° C for 168 hours using diethanolamine / water = 50/50 wt%. 100% modulus after immersion test (M100), tensile strength at break (Tb), tensile elongation at break (Eb), hardness (Hs [Shore A, peak]), volume swell ratio (ΔV), values before immersion The rate of change with respect to was calculated. ΔV is the rate of change of volume after the sample piece is immersed under a predetermined condition (representing the degree of swelling). When the original volume of the sample piece is Vo and the volume after the test is V, ΔV = It is represented by (V−Vo) / Vo × 100. The volume is calculated from the weight in air and the weight in water.

Steam resistance test A 500ml sealed autoclave is charged with ion-exchanged water that exceeds saturated steam pressure at 200 ° C, and the sample is hung and sealed so that the sample does not touch the ion-exchanged water on the bottom. And heated in an electric furnace for 168 hours. 100% modulus after immersion test (M100), tensile strength at break (Tb), tensile elongation at break (Eb), hardness (Hs [Shore A, peak]), volume swell ratio (ΔV), values before immersion The rate of change with respect to was calculated. ΔV is the rate of change of volume after the sample piece is immersed under a predetermined condition (representing the degree of swelling). When the original volume of the sample piece is Vo and the volume after the test is V, ΔV = It is represented by (V−Vo) / Vo × 100. The volume is calculated from the weight in air and the weight in water.

Each material described in Table 1 used in Examples and Comparative Examples is shown below.
Fluoro rubber 1: VdF / 2,3,3,3-tetrafluoropropene = 71/29 mol%, glass transition temperature −6 ° C., iodine content 0.16% by weight
Fluoro rubber 2: VdF / 2,3,3,3-tetrafluoropropene = 77/23 mol%, glass transition temperature −13 ° C., iodine content 0.12% by weight
Fluoro rubber 3: VdF / 2,3,3,3-tetrafluoropropene = 80/20 mol%, glass transition temperature −15 ° C., iodine content 0.14% by weight
Fluoro rubber 4: VdF / HFP = 78/22 mol%, glass transition temperature −20 ° C., iodine content 0.18% by weight
Fluoro rubber 5: TFE / Pr = 55/45 mol%, glass transition temperature 3 ° C.
Fluoro rubber 6: VdF / TFE / Pr = 35/40/25 mol%, glass transition temperature −9 ° C.
Carbon black triallyl isocyanurate 2,5-dimethyl-2,5-di (t-butylperoxy) hexane 1,3-bis (t-butylperoxy) -diisopropylbenzene sodium stearate MgO: magnesium oxide

Production Examples 1-6
Crosslinkable compositions 1 to 3 having the compositions shown in Table 1 were produced. Moreover, the crosslinkable compositions 4-6 were manufactured by the composition shown in following Table 1 for a comparison.
The crosslinkable compositions 1 to 6 were prepared by blending the fluororubbers 1 to 6 (raw rubber) and various additives in the amounts shown in Table 1 using an 8-inch oven roll and mixing them in a usual manner.

Vulcanization characteristics were examined using the crosslinkable compositions 1 to 6 produced in Production Examples 1 to 6. Vulcanization characteristics are determined according to JIS K6300-2 with RUBBER PROCESSSANARY ANALYZER RPA2000 (manufactured by ALPHA TECHNOLOGIES), minimum torque (ML), maximum torque (MH), induction time (T10) and optimum vulcanization time (T90). Was measured. The results are shown in Table 2 below.

Examples 1-3 and Comparative Examples 1-3
Mechanical properties, compression set, low temperature properties, and fuel oil resistance were examined for molded products (fluoropolymer parts) crosslinked with the crosslinkable compositions 1-6. Mechanical properties were measured in accordance with JIS K 6251, 6253, 6268 by measuring 100% modulus (M100), tensile breaking strength (Tb), tensile breaking elongation (Eb), and hardness (Hs [Shore A, peak]). The compression set was measured at 200 ° C. for 70 hours in accordance with JIS K 6262. The low temperature property was subjected to a TR test in accordance with JIS K 6261, and the shape restoration property was measured. In addition, an oil immersion test was conducted as a fuel resistance test. The results are shown in Table 2 below.

Crosslinkable compositions 1-3 have a fast vulcanization rate, and fluoropolymer parts made from crosslinkable compositions 1-3 have good processability, compression set (sealability), and Has fuel oil resistance. In addition, fluoropolymer parts made from the crosslinkable compositions 2-3 have good low temperature properties.

Next, an oil resistance test, an amine resistance test, and a steam resistance test were performed on the molded products obtained by crosslinking the respective crosslinkable compositions. The results are shown in Table 3 below.

In Examples 1 to 3, deterioration was slight even when immersed in oil and amine, and excellent resistance to oil and amine was exhibited. In Comparative Examples 1 and 3, the physical property deterioration is significant when immersed in oil and amine. In addition, regarding the steam properties, Examples 1 to 3 showed slight deterioration and excellent resistance.

Claims (4)

A fluoropolymer part for use in oil, gas exploration, drilling or production,
It is obtained by crosslinking a crosslinkable composition containing a fluoropolymer having a glass transition temperature of 25 ° C. or less and a crosslinking agent,
The fluoropolymer includes vinylidene fluoride and the following general formula (1):
CH ₂ = CFRf (1)
(In the formula, Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms.)
A fluoropolymer component comprising a copolymer comprising a fluorine-containing monomer (1) represented by the formula: The copolymer is
A copolymer (I) comprising only vinylidene fluoride and a fluorine-containing monomer (1), and having a vinylidene fluoride unit / fluorine monomer (1) unit molar ratio of 87/13 to 22/78,
Containing only vinylidene fluoride, fluorine-containing monomer (1), and other monomers copolymerizable with vinylidene fluoride and fluorine-containing monomer (1), vinylidene fluoride unit / fluorine-containing monomer Copolymer (II) in which the molar ratio of the body (1) units is 85/15 to 20/80, and the other monomer units are 1 to 50 mol% of the total monomer units, and
Containing vinylidene fluoride, fluorine-containing monomer (1), and other monomers copolymerizable with vinylidene fluoride and fluorine-containing monomer (1), vinylidene fluoride unit / fluorine-containing monomer (1) The molar ratio of the units is 85/15 to 20/80, the other monomer units are 0 to 50 mol% of the total monomer units, and have at least one of iodine atom and bromine atom , A copolymer (III) having a total content of 0.001 to 10% by weight,
The fluoropolymer component according to claim 1, wherein the fluoropolymer component is at least one selected from the group consisting of: The copolymer is
Containing vinylidene fluoride, fluorine-containing monomer (1), and other monomers copolymerizable with vinylidene fluoride and fluorine-containing monomer (1), vinylidene fluoride unit / fluorine-containing monomer (1) The molar ratio of the units is 85/15 to 20/80, the other monomer units are 0 to 50 mol% of the total monomer units, and have at least one of iodine atom and bromine atom And a copolymer (III) having a total content of 0.001 to 10% by weight
The fluoropolymer component according to claim 1 or 2. A method for preventing or reducing the hardening or swelling of fluoropolymer parts used in exploration, drilling or production of oil or gas comprising:
Including the step of producing a fluoropolymer component by crosslinking a crosslinkable composition comprising a fluoropolymer having a glass transition temperature of 25 ° C. or less and a crosslinking agent,
The fluoropolymer includes vinylidene fluoride and the following general formula (1):
CH ₂ = CFRf (1)
(In the formula, Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms.)
A method comprising a copolymer comprising a fluorine-containing monomer (1) represented by the formula: