JP2013173930A - Member resistant to biodiesel fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member resistant to biodiesel fuel, the member being excellent in resistance to biodiesel fuel and having excellent tensile properties and cracking resistance at high temperatures.SOLUTION: A member resistant to biodiesel fuel can be obtained by crosslinking a fluororubber composition including a fluororubber (A) and a carbon black (B). In the member resistant to the biodiesel fuel, the crosslinked fluororubber has a loss elastic modulus E'' of ≥400 kPa and ≤6,000 kPa, in a dynamic viscoelasticity test carried out in a condition that: measurement temperature is 160°C; tensile strain is 1%; a static tension value when a static load condition at distortion variance is made constant is 157 cN; and frequency is 10 Hz.

Description

The present invention relates to a biodiesel fuel member excellent in tensile properties and crack resistance at high temperatures.

In recent years, biodiesel fuel (BDF) has attracted attention as a measure against global warming. Biodiesel fuel is known to swell or deteriorate rubbers, resins, and the like used for automobile parts. In particular, when biodiesel fuel is oxidized by heat or pressure, peroxide and acid are generated to accelerate the deterioration of rubber, resin and the like.

Examples of the rubber having improved durability against biodiesel fuel include, for example, a component of a fuel management system having a surface including a fluoroelastomer layer in which a hydrotalcite compound is dispersed in the layer (see, for example, Patent Document 1). A fluorine-containing elastomer composition containing a polyol-crosslinkable fluorine-containing elastomer, a polyol-crosslinking agent and an alkali metal silicate (see, for example, Patent Document 2), a polyol-crosslinkable fluorine-containing elastomer, a polyol crosslinking agent, and basic silica A fluorine-containing elastomer composition containing a fluorine-containing elastomer composition (see, for example, Patent Document 3), a polyol-crosslinkable fluorine-containing elastomer, a polyol-based crosslinking agent, and hydrotalcites, and oxidizing a divalent metal Acid acceptor consisting only of substances or hydroxides Fluorine-containing elastomer composition is not more than 2 parts by weight of the fluorine-containing elastomer 100 parts by weight (e.g., see Patent Document 4.) It has been proposed.

JP-T-2006-513304 Special table 2011-522921 gazette JP 2010-24339 A Table 2007-135937

In the case of using biodiesel fuel, members that are in direct contact with the fuel, such as fuel hoses and sealing materials, are required to have biodiesel fuel resistance such as swelling resistance to biodiesel fuel.
Moreover, the member which contacts with biodiesel fuel is used in a high temperature environment compared with the time of gasoline use. For this reason, the member in contact with the biodiesel fuel is required to have excellent mechanical properties, for example, excellent tensile properties and crack resistance even in a higher temperature range.

An object of the present invention is to provide a biodiesel fuel member that is excellent in biodiesel fuel resistance and excellent in tensile properties and crack resistance at high temperatures.

The present invention is a biodiesel fuel-resistant member comprising a crosslinked fluororubber obtained by crosslinking a fluororubber composition containing fluororubber (A) and carbon black (B), the crosslinked fluororubber having dynamic viscoelasticity Loss elastic modulus E ″ in the test (measurement temperature: 160 ° C., tensile strain: 1%, static tension value when the static load condition during strain dispersion is constant force: 157 cN, frequency: 10 Hz) is 400 kPa to 6000 kPa It is a biodiesel-resistant fuel member characterized by being.

ADVANTAGE OF THE INVENTION According to this invention, while being excellent in biodiesel fuel resistance, the biodiesel fuel member excellent also in the tensile characteristic and crack resistance at the time of high temperature can be provided.

It is a figure which shows typically the kneading | mixing method in a process (2-1) and a process (2-2).

The biodiesel-resistant fuel member of the present invention has a dynamic viscoelasticity test (measurement temperature: 160 ° C., tensile strain: 1%, static tension value when the static load condition during strain dispersion is constant force: 157 cN, frequency: By forming the cross-linked fluororubber having a loss elastic modulus E ″ at 10 Hz) of 400 kPa or more and 6000 kPa or less, excellent tensile properties and crack resistance can be exhibited even in a use temperature range higher than that when using gasoline.

In this specification, a biodiesel fuel (BDF) means what contains the fuel for diesel engines obtained by processing and / or refine | purifying biomass as a raw material. Biodiesel fuel includes refined oils and fats, aliphatic alkyl esters obtained by alkylating fats and oils, fuels hydrogenated to fats and oils (BHD), and liquid fuels synthesized from raw materials such as methane generated from biomass (BTL-FT) Fuel), fuels obtained by mixing these fuels with existing fossil fuels (light oil), and the like.

The biodiesel-resistant fuel member of the present invention can be widely used from those obtained by slightly adding biodiesel to light oil to those using 100% biodiesel. Among them, it can be particularly preferably used for those added with 10% or more of biodiesel.

Examples of the aliphatic alkyl esters include aliphatic methyl esters, aliphatic ethyl esters, and the like, and may be those obtained by esterifying animal fats or oils or those obtained by esterifying vegetable fats and oils.

Examples of the oils and fats include vegetable oils such as rapeseed oil, sunflower oil, soybean oil, corn oil, palm oil, olive oil, rice oil, and coconut oil, animal oils such as fish oil and beef fat, and waste cooking oils thereof. It is done.

The fluororubber composition for forming the crosslinked fluororubber constituting the biodiesel resistant fuel member of the present invention contains fluororubber (A) and carbon black (B). Below, each component of the said fluororubber composition is demonstrated.

(A) Fluoro rubber As the fluoro rubber (A) used in the present invention, for example, tetrafluoroethylene (TFE), vinylidene fluoride (VdF), and formula (1):
CF ₂ = CF-R _f ^a (1)
(Wherein R _f ^a is —CF ₃ or OR _f ^b (R _f ^b is a perfluoroalkyl group having 1 to 5 carbon atoms)) (for example, hexafluoropropylene (HFP) ), Perfluoro (alkyl vinyl ether) (PAVE), etc.), it is preferable to include a structural unit derived from at least one monomer selected from the group consisting of.

From another viewpoint, as the fluororubber (A), non-perfluorofluororubber and perfluorofluororubber are preferable.

Non-perfluoro fluororubbers include vinylidene fluoride (VdF) fluororubber, tetrafluoroethylene (TFE) / propylene (Pr) fluororubber, tetrafluoroethylene (TFE) / propylene (Pr) / vinylidene fluoride (VdF). ) -Based fluoro rubber, ethylene (Et) / hexafluoropropylene (HFP) -based fluoro rubber, ethylene (Et) / hexafluoropropylene (HFP) / vinylidene fluoride (VdF) -based fluoro rubber, ethylene (Et) / hexafluoropropylene (HFP) / tetrafluoroethylene (TFE) -based fluororubber, fluorosilicone-based fluororubber, fluorophosphazene-based fluororubber, and the like, and these may be used alone or in any combination as long as the effects of the present invention are not impaired. Use Door can be. Among these, VdF type fluororubber, TFE / Pr type fluororubber, and TFE / Pr / VdF type fluororubber are more preferable from the viewpoint of good heat aging resistance and oil resistance.

In the VdF fluororubber, the content of VdF repeating units is preferably 20 mol% or more, more preferably 40 mol% or more based on the total number of moles of VdF repeating units and repeating units derived from other comonomers. Preferably, it is more preferably 45 mol% or more, still more preferably 50 mol% or more, particularly preferably 55 mol% or more, and most preferably 60 mol% or more. The content of the VdF repeating unit is preferably 90 mol% or less, more preferably 85 mol% or less, and more preferably 80 mol% or less, based on the total number of moles of the VdF repeating unit and the repeating unit derived from another comonomer. Is more preferably 78 mol% or less, particularly preferably 75 mol% or less, and most preferably 70 mol% or less.

In addition, the content of the repeating unit derived from the other comonomer is preferably 10 mol% or more based on the total number of moles of the VdF repeating unit and the repeating unit derived from the other comonomer. % Or more is more preferable, 20 mol% or more is still more preferable, 22 mol% or more is still more preferable, 25 mol% or more is especially preferable, and 30 mol% or more is the most preferable. The content of the repeating unit derived from the other comonomer is preferably 80 mol% or less, preferably 60 mol% or less, based on the total number of moles of the VdF repeating unit and the repeating unit derived from the other comonomer. Is more preferably 55 mol% or less, still more preferably 50 mol% or less, particularly preferably 45 mol% or less, and most preferably 40 mol% or less.

The comonomer in the VdF-based fluororubber is not particularly limited as long as it is copolymerizable with VdF. For example, TFE, HFP, PAVE, chlorotrifluoroethylene (CTFE), trifluoroethylene, trifluoropropylene, tetra Fluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, hexafluoroisobutene, vinyl fluoride, iodine-containing fluorinated vinyl ether, the following general formula (2):
CH ₂ = CFR _f (2)
(Wherein _Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms) fluorine-containing monomers such as fluorine-containing monomers; ethylene (Et), propylene (Pr), alkyl Non-fluorine-containing monomers such as vinyl ether, monomers that give a crosslinkable group (cure site), and reactive emulsifiers, etc., and one or more of these monomers and compounds They can be used in combination.

As the PAVE, perfluoro (methyl vinyl ether) (PMVE) and perfluoro (propyl vinyl ether) (PPVE) are preferable, and PMVE is particularly preferable.

Further, as the above-mentioned comonomer, the following general formula:
CF ₂ = CFOCF ₂ OR _f ^c
(Wherein, R _f ^c is a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, cyclic perfluoroalkyl group of 5-6 carbon atoms, or carbon atoms containing one to three oxygen atoms Perfluorovinyl ether represented by 2 to 6 linear or branched perfluorooxyalkyl groups), for example, CF ₂ = CFOCF ₂ OCF ₃ , CF ₂ = CFOCF ₂ OCF ₂ CF ₃ , _or, it is preferable to use _{CF 2 = CFOCF 2 OCF 2 CF} 2 OCF 3.

The fluorine-containing monomer (2) represented by the general formula (2) is preferably a monomer in which R _f is a linear fluoroalkyl group, and R _f is a linear perfluoroalkyl group. Monomers are more preferred. R _f preferably has 1 to 6 carbon atoms. Examples of the fluorine-containing monomer represented by the general formula (2) include CH ₂ = CFCF ₃ , CH ₂ = CFCF ₂ CF ₃ , CH ₂ = CFCF ₂ CF ₂ CF ₃ , CH ₂ = CFCF ₂ CF ₂ CF. ₂ CF _{3 and the} like, and 2,3,3,3-tetrafluoropropylene represented by CH ₂ ═CFCF ₃ is particularly preferable.

Examples of the VdF-based fluororubber include VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / CTFE copolymer, VdF / CTFE / TFE copolymer, VdF / PAVE copolymer, VdF / TFE. / PAVE copolymer, VdF / HFP / PAVE copolymer, VdF / HFP / TFE / PAVE copolymer, VdF / TFE / propylene (Pr) copolymer, VdF / ethylene (Et) / HFP copolymer and VdF / At least one copolymer selected from the group consisting of copolymers of fluorine-containing monomer (2) represented by formula (2) is preferred, and other comonomers other than VdF More preferably, it has at least one comonomer selected from the group consisting of TFE, HFP and PAVE. Among these, VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / copolymer of fluorine-containing monomer (2) represented by formula (2), VdF / PAVE copolymer, Preferred is at least one copolymer selected from the group consisting of VdF / TFE / PAVE copolymer, VdF / HFP / PAVE copolymer and VdF / HFP / TFE / PAVE copolymer, and VdF / HFP copolymer At least one selected from the group consisting of a polymer, a VdF / HFP / TFE copolymer, a VdF / copolymer of fluorine-containing monomer (2) represented by formula (2), and a VdF / PAVE copolymer Is more preferably selected from the group consisting of VdF / HFP copolymer, VdF / copolymer of fluorine-containing monomer (2) represented by formula (2), and VdF / PAVE copolymer. Less Also one copolymer is particularly preferred.

The VdF / HFP copolymer preferably has a VdF / HFP composition of (45 to 85) / (55 to 15) (mol%), more preferably (50 to 80) / (50 to 20). (Mol%), more preferably (60-80) / (40-20) (mol%).

The VdF / TFE / HFP copolymer preferably has a VdF / TFE / HFP composition of (30-80) / (4-35) / (10-35) (mol%).

As the VdF / PAVE copolymer, a VdF / PAVE composition having a composition of (65 to 90) / (35 to 10) (mol%) is preferable.

As the VdF / TFE / PAVE copolymer, a VdF / TFE / PAVE composition having a composition of (40-80) / (3-40) / (15-35) (mol%) is preferable.

As the VdF / HFP / PAVE copolymer, a VdF / HFP / PAVE composition having a composition of (65 to 90) / (3 to 25) / (3 to 25) (mol%) is preferable.

As a VdF / HFP / TFE / PAVE copolymer, the composition of VdF / HFP / TFE / PAVE is (40-90) / (0-25) / (0-40) / (3-35) (mol%). The thing of (40-80) / (3-25) / (3-40) / (3-25) (mol%) is more preferable.

As the fluorine-containing monomer (2) -based copolymer represented by VdF / formula (2), the molar ratio of VdF / fluorine-containing monomer (2) unit is 85/15 to 20/80. , VdF and other monomer units other than the fluorine-containing monomer (2) are preferably 0 to 50 mol% of all monomer units, and VdF / mol% of the fluorine-containing monomer (2) unit. The ratio is more preferably 80/20 to 20/80. The molar ratio of VdF / fluorinated monomer (2) unit is 85/15 to 50/50, and other monomer units other than VdF and fluorine-containing monomer (2) are all monomer units. Those having a content of 1 to 50 mol% are also preferred. As monomers other than VdF and fluorine-containing monomer (2), TFE, HFP, PMVE, perfluoroethyl vinyl ether (PEVE), PPVE, CTFE, trifluoroethylene, hexafluoroisobutene, vinyl fluoride, Monomers exemplified as the above-mentioned VdF comonomer, such as ethylene (Et), propylene (Pr), alkyl vinyl ether, a monomer that gives a crosslinkable group, and a reactive emulsifier, are preferable, and among them, PMVE, CTFE, HFP, and TFE are more preferable.

The TFE / propylene (Pr) -based fluororubber is a fluorine-containing copolymer composed of TFE 45 to 70 mol% and propylene (Pr) 55 to 30 mol%. In addition to these two components, a specific third component (for example, PAVE) may be contained in an amount of 0 to 40 mol% based on the total of TFE units and propylene units.

As an ethylene (Et) / HFP copolymer, it is preferable that the composition of Et / HFP is (35-80) / (65-20) (mol%), (40-75) / (60-25) ) (Mol%) is more preferable.

In the Et / HFP / TFE copolymer, the composition of Et / HFP / TFE is preferably (35 to 75) / (25 to 50) / (0 to 15) (mol%), and (45 to 75). ) / (25-45) / (0-10) (mol%) is more preferred.

Examples of the perfluoro fluorine rubber include those made of TFE / PAVE. The composition of TFE / PAVE is preferably (50 to 90) / (50 to 10) (mol%), more preferably (50 to 80) / (50 to 20) (mol%), More preferably, it is (55-75) / (45-25) (mol%).

Examples of PAVE in this case include PMVE, PPVE, and the like, and these can be used alone or in any combination.

In addition, as the fluororubber (A), a copolymer obtained by copolymerizing a monomer that gives a crosslinkable group can be suitably used. As the monomer that gives a crosslinkable group, any monomer that can introduce an appropriate crosslinkable group depending on the production method and the crosslinking system may be used. For example, an iodine atom, a bromine atom, a carbon-carbon double bond, a cyano group, Examples include known polymerizable compounds containing a carboxyl group, a hydroxyl group, an amino group, an ester group, a chain transfer agent, and the like.

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（式中、ｎは２〜８の整数）
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で表されるヨウ素含有モノマー、臭素含有モノマー等が挙げられ、これらをそれぞれ単独で、又は任意に組合わせて用いることができる。 As a monomer that gives a preferred crosslinkable group,
The following general formula (3):
CY ¹ ₂ = CY ² R _f ² X ¹ (3)
Wherein Y ¹ and Y ² are the same or different and are a fluorine atom, a hydrogen atom or CH ₃ ; R _f ² may have one or more ether bonds and has an aromatic ring. Or a linear or branched fluorine-containing alkylene group in which part or all of the hydrogen atoms are substituted with fluorine atoms; X ¹ is an iodine atom or a bromine atom)
The compound shown by these is mentioned. Specifically, for example, the following general formula (4):
CY ¹ ₂ = CY ² R _f ³ CHR ¹ -X ¹ (4)
(In the formula, Y ¹ , Y ² , and X ¹ are the same as described above, and R _f ³ may have one or more ether bonds, and a hydrogen atom may be partially or entirely substituted with a fluorine atom. Chain or branched fluorine-containing alkylene group, that is, a linear or branched fluorine-containing alkylene group in which part or all of the hydrogen atoms are substituted with fluorine atoms, or part or all of the hydrogen atoms are substituted with fluorine atoms A linear or branched fluorine-containing oxyalkylene group, or a linear or branched fluorine-containing polyoxyalkylene group in which some or all of the hydrogen atoms are substituted with fluorine atoms; R ¹ is a hydrogen atom or Methyl group)
Iodine-containing monomer, bromine-containing monomer represented by the following general formulas (5) to (22):
CY ⁴ ₂ = CY ⁴ (CF ₂ ) _n -X ¹ (5)
(Wherein Y ⁴ is the same or different and is a hydrogen atom or a fluorine atom, n is an integer of 1 to 8)
^{_{CF 2 = CFCF 2 R f 4}} -X 1 (6)
(Where

And n is an integer from 0 to 5)
CF ₂ = CFCF ₂ (OCF (CF ₃ ) CF ₂ ) _{m
(OCH 2 CF 2 CF 2)} n OCH 2 CF 2 -X 1 (7)
(In the formula, m is an integer of 0 to 5, n is an integer of 0 to 5)
CF ₂ = CFCF ₂ (OCH ₂ CF ₂ CF ₂ ) _{m
(OCF (CF 3) CF 2} ) n OCF (CF 3) -X 1 (8)
(In the formula, m is an integer of 0 to 5, n is an integer of 0 to 5)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m O (CF 2) n -X 1 (9)
(Wherein, m is an integer from 0 to 5, and n is an integer from 1 to 8)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m -X 1 (10)
(Where m is an integer from 1 to 5)
CF ₂ = CFOCF ₂ (CF (CF ₃ ) OCF ₂ ) _n CF (−X ¹ ) CF ₃ (11)
(Where n is an integer from 1 to 4)
_{CF 2 = CFO (CF 2)} n OCF (CF 3) -X 1 (12)
(Where n is an integer from 2 to 5)
_{CF 2 = CFO (CF 2)} n - (C 6 H 4) -X 1 (13)
(Where n is an integer from 1 to 6)
_{CF 2 = CF (OCF 2 CF} (CF 3)) n OCF 2 CF (CF 3) -X 1 (14)
(Where n is an integer from 1 to 2)
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) n CF (CF 3) -X 1 (15)
(Where n is an integer from 0 to 5),
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 1 (16)
(In the formula, m is an integer of 0 to 5, n is an integer of 1 to 3)
_{CH 2 = CFCF 2 OCF (CF} 3) OCF (CF 3) -X 1 (17)
_{CH 2 = CFCF 2 OCH 2 CF} 2 -X 1 (18)
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m CF 2 CF (CF 3) -X 1 (19)
(Where m is an integer of 0 or more)
_{CF 2 = CFOCF (CF 3)} CF 2 O (CF 2) n -X 1 (20)
(Where n is an integer of 1 or more)
_{CF 2 = CFOCF 2 OCF 2 CF} (CF 3) OCF 2 -X 1 (21)
^{_{CH 2 = CH- (CF 2)}} n X 1 (22)
(Where n is an integer from 2 to 8)
(In the above general formulas (5) to (22), X ¹ is the same as above)
The iodine-containing monomer represented by these, the bromine-containing monomer, etc. are mentioned, These can be used individually or in arbitrary combinations, respectively.

（式中、ｍは１〜５の整数であり、ｎは０〜３の整数）
で表されるヨウ素含有フッ素化ビニルエーテルが好ましく挙げられ、より具体的には、

等が挙げられるが、これらの中でも、ＩＣＨ_２ＣＦ_２ＣＦ_２ＯＣＦ＝ＣＦ_２が好ましい。 As the iodine-containing monomer or bromine-containing monomer represented by the general formula (4), the following general formula (23):

(In the formula, m is an integer of 1 to 5, and n is an integer of 0 to 3).
Preferred examples include iodine-containing fluorinated vinyl ethers represented by:

Among them, ICH ₂ CF ₂ CF ₂ OCF═CF ₂ is preferable among these.

More specifically, preferred examples of the iodine-containing monomer or bromine-containing monomer represented by the general formula (5) include ICF ₂ CF ₂ CF═CH ₂ and I (CF ₂ CF ₂ ) ₂ CF═CH ₂ .

More specifically, the iodine-containing monomer or bromine-containing monomer represented by the general formula (9) is preferably I (CF ₂ CF ₂ ) ₂ OCF═CF ₂ .

More specifically, preferred examples of the iodine-containing monomer or bromine-containing monomer represented by the general formula (22) include CH ₂ ═CHCF ₂ CF ₂ I and I (CF ₂ CF ₂ ) ₂ CH═CH ₂ .

Further, the ^{formula: R 2 R 3 C = CR} 4 -Z-CR 5 = CR 6 R 7
(In the formula, R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different, and all are H or an alkyl group having 1 to 5 carbon atoms; Z is linear or branched. A bisolefin compound which may contain an oxygen atom, and preferably is an at least partially fluorinated alkylene or cycloalkylene group having 1 to 18 carbon atoms, or (per) fluoropolyoxyalkylene group). Preferred as a monomer for providing a functional group. In the present specification, “(per) fluoropolyoxyalkylene group” means “fluoropolyoxyalkylene group or perfluoropolyoxyalkylene group”.

Z is preferably a (per) fluoroalkylene group having 4 to 12 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are preferably hydrogen atoms.

When Z is a (per) fluoropolyoxyalkylene group, the formula:
_{- (Q) p -CF 2 O-} (CF 2 CF 2 O) m - (CF 2 O) n -CF 2 - (Q) p -
(In the formula, Q is an alkylene group having 1 to 10 carbon atoms or an oxyalkylene group having 2 to 10 carbon atoms, p is 0 or 1, and m and n have an m / n ratio of 0.2 to 5. And the (per) fluoropolyoxyalkylene group is an integer such that the molecular weight of the (per) fluoropolyoxyalkylene group is in the range of 500 to 10,000, preferably 1000 to 4000. . In this formula, Q is preferably selected from —CH ₂ OCH ₂ — and —CH ₂ O (CH ₂ CH ₂ O) _s CH ₂ — (s = 1 to 3).

Preferred bisolefins are
_{CH 2 = CH- (CF 2)} 4 -CH = CH 2,
_{CH 2 = CH- (CF 2)} 6 -CH = CH 2,
^{_{Formula: CH 2 = CH-Z 1}} -CH = CH 2
(In the formula, Z ¹ represents —CH ₂ OCH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _m — (CF ₂ O) _n —CF ₂ —CH ₂ OCH ₂ — (m / n is 0.5)). )
Etc.

Among _{them, CH 2 = CH- (CF 2} ) 6 represented by -CH = CH ₂ 3,3,4,4,5,5,6,6,7,7,8,8- dodecafluoro -1, 9-decadiene is preferred.

The fluororubber (A) is selected from the group consisting of a vinylidene fluoride copolymer, a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer, and a tetrafluoroethylene / propylene copolymer among the above-mentioned ones. It is preferable that it is at least one kind.

The fluororubber (A) preferably has a number average molecular weight Mn of 5,000 to 500,000, more preferably 10,000 to 500,000, particularly preferably 20,000 to 500,000.

For example, when it is desired to lower the viscosity of the fluororubber composition, other fluororubbers may be blended with the fluororubber (A). Examples of other fluororubber include low molecular weight liquid fluororubber (number average molecular weight of 1000 or more), low molecular weight fluororubber having a number average molecular weight of about 10,000, and fluororubber having a number average molecular weight of about 100,000 to 200,000.

From the viewpoint of processability, the fluororubber (A) preferably has a Mooney viscosity at 100 ° C. in the range of 20 to 200, and more preferably in the range of 30 to 180. The Mooney viscosity is measured according to JIS K6300.

The non-perfluorofluororubber and perfluorofluororubber described above can be produced by conventional methods such as emulsion polymerization, suspension polymerization, and solution polymerization. In particular, according to a polymerization method using an iodine (bromine) compound known as iodine (bromine) transfer polymerization, a fluororubber having a narrow molecular weight distribution can be produced. In the polymerization, each condition such as temperature and pressure, polymerization initiator, emulsifier and other additives can be appropriately set according to the composition and amount of the non-perfluorofluororubber and perfluorofluororubber. The non-perfluorofluororubber and the perfluorofluororubber can be produced by the production methods disclosed in JP 2009-52034 A and WO 2008/001895 pamphlet.

Examples of the polymerization initiator include oil-soluble radical polymerization initiators typified by peroxycarbonates such as diisopropyl peroxydicarbonate (IPP) and di-n-propyl peroxydicarbonate (NPP). Water-soluble radical polymerization initiators such as persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, ammonium percarbonate, potassium salt and sodium salt can be used.

The emulsifier is not particularly limited as long as it does not contain a metal atom. For example, from the viewpoint of suppressing a chain transfer reaction to an emulsifier molecule during polymerization, a carboxylic acid having a fluorocarbon chain or a fluoropolyether chain is used. Salts are preferred.

Specifically, for example, ammonium perfluorooctanoate, CF ₃ (CF ₂ ) _n COONH ₄ (n = 2 to 8), CHF ₂ (CF ₂ ) _n COONH ₄ (n = 6 to 8), C ₃ F ₇ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH ₄ , CH ₂ ═CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH _{4 and the} like.

(B) Carbon black Examples of the carbon black (B) used in the present invention include furnace black, acetylene black, thermal black, channel black, graphite, and the like. Specifically, for example, SAF-HS (N ₂ SA: 142 m ² / g, DBP: 130 ml / 100 g), SAF (N ₂ SA: 142 m ² / g, DBP: 115 ml / 100 g), N234 (N ₂ SA: 126 m ² / g, DBP: 125 ml / 100 g), ISAF (N ₂ SA: 119 m ² / g, DBP: 114 ml / 100 g), ISAF-LS (N ₂ SA: 106 m ² / g, DBP: 75 ml / 100 g), ISAF-HS (N ₂ SA: 99 m ² / g, DBP: 129 ml / 100 g), N339 (N ₂ SA: 93 m ² / g, DBP 119 ml / 100 g), HAF-LS (N ₂ SA: 84 m ² / g, DBP: 75 ml / 100 g), HAS-HS (N ₂ SA: 82 m ² / g, DBP: 126 ml / 100 g), HAF (N ₂ SA: 79 m ² / g, DBP: 101 ml / 100 g), N351 (N ₂ SA: 74 m ² / g, DBP: 127 ml / 100 g), LI-HAF (N ₂ SA: 74 m ² / g, DBP: 101 ml / 100 g) ), MAF-HS (N ₂ SA: 56 m ² / g, DBP: 158 ml / 100 g), MAF (N ₂ SA: 49 m ² / g, DBP: 133 ml / 100 g), FEF-HS (N ₂ SA: 42 m ^{2 _{/ g, DBP: 160ml / 100g}} ), FEF (N 2 SA: 42m 2 / g, DBP: 115ml / 100g), SRF-H ^{_{(N 2 SA: 32m 2 /}} g, DBP: 140ml / 100g), SRF-HS (N 2 SA: 29m 2 / g, DBP: 152ml / 100g), GPF (N 2 SA: 27m 2 / g, DBP: 87 ml / 100 g), SRF (N ₂ SA: 27 m ² / g, DBP: 68 ml / 100 g) and the like. Among these, SAF-HS, SAF, N234, ISAF, ISAF-LS, ISAF-HS, N339, HAF-LS, HAS-HS, HAF, N351, LI-HAF, and MAF-HS are preferable. These carbon blacks may be used alone or in combination of two or more.

Among these, carbon black (B) is preferably carbon having a nitrogen adsorption specific surface area (N ₂ SA) of 25 to 180 m ² / g and a dibutyl phthalate (DBP) oil absorption of 40 to 180 ml / 100 g. Black. When carbon black having a high value of N ₂ SA or DBP is used, the loss elastic modulus E ″ and storage elastic modulus E ′ of the obtained crosslinked fluororubber, which will be described later, increase.

If the nitrogen adsorption specific surface area (N ₂ SA) is smaller than 25 m ² / g, the mechanical properties when blended with rubber tend to decrease. From this viewpoint, the nitrogen adsorption specific surface area (N ₂ SA) is 50 m ^2. / G or more is preferable, 70 m ² / g or more is more preferable, 90 m ² / g or more is more preferable, and 110 m ² / g or more is particularly preferable. The upper limit is preferably 180 m ² / g from the viewpoint of easy availability.

When the dibutyl phthalate (DBP) oil absorption is less than 40 ml / 100 g, the mechanical properties when blended with rubber tend to decrease. From this viewpoint, 50 ml / 100 g or more, further 60 ml / 100 g or more, particularly 80 ml. / 100g or more is preferable. From the viewpoint of easy availability, the upper limit is preferably 175 ml / 100 g, more preferably 170 ml / 100 g.

As for the compounding quantity of carbon black (B), 5-65 mass parts is preferable with respect to 100 mass parts of fluororubbers (A). If the carbon black (B) is too much, the mechanical properties of the cross-linked product tend to decrease, and if it is too small, the mechanical properties of the cross-linked product tend to decrease. Furthermore, from a point with a favorable physical property balance, 6 mass parts or more are more preferable with respect to 100 mass parts of fluororubber (A), 10 mass parts or more are still more preferable, and 55 mass parts or less are more from a point with a favorable physical property balance. Preferably, 50 parts by mass or less is further preferable, 49 parts by mass or less is even more preferable, and 45 parts by mass or less is particularly preferable.

The fluororubber composition in the present invention may further contain the following other components as long as the fluororubber (A) and the carbon black (B) described above are included.

(C) Crosslinking agent and (D) Crosslinking accelerator The fluororubber composition in the present invention preferably contains a crosslinking agent (C) and / or a crosslinking accelerator (D).
The cross-linking agent (C) and the cross-linking accelerator (D) are specific uses of the cross-linking system, the type of fluororubber (A) to be cross-linked (for example, copolymer composition, presence / absence or type of cross-linkable group), and the resulting cross-linked product. It can be appropriately selected depending on the use form and other kneading conditions.

As the crosslinking system, for example, a peroxide crosslinking system, a polyol crosslinking system, a polyamine crosslinking system, an oxazole crosslinking system, a thiazole crosslinking system, an imidazole crosslinking system, a triazine crosslinking system, and the like can be employed.

(Peroxide crosslinking system)
When cross-linking with a peroxide cross-linking system, it has a carbon-carbon bond at the cross-linking point. Compared with it, it is characterized by excellent chemical resistance and steam resistance.

The peroxide crosslinking agent may be a peroxide that can easily generate a peroxy radical in the presence of heat or a redox system. Specifically, 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-butylperoxy) -p-diisopropylbenzene, α, α-bis (t-butylperoxy) -m-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-butyl peroxybenzoate, t- butyl peroxy maleic acid, and organic peroxides such as t-butyl peroxy isopropyl carbonate. Among these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane or 2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne-3 is preferable.

In addition, in the peroxide crosslinking system, it is usually preferable to include a crosslinking accelerator. Examples of crosslinking accelerators for peroxide crosslinking agents, particularly organic peroxide crosslinking agents include triallyl cyanurate, triallyl isocyanurate (TAIC), triacryl formal, triallyl trimellitate, N, N '-M-phenylene bismaleimide, 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, N, N-diallylacrylamide, 1,6-divinyldodecafluorohexane, hexaallyl Phosphoramide, N, N, N ′, N′-tetra Rylphthalamide, N, N, N ′, N′-tetraallylmalonamide, trivinyl isocyanurate, 2,4,6-trivinylmethyltrisiloxane, tri (5-norbornene-2-methylene) cyanurate, triallyl Examples thereof include phosphite. Among these, triallyl isocyanurate (TAIC) is preferable from the viewpoint of crosslinkability and physical properties of the cross-linked product.

As a crosslinking accelerator used in the peroxide crosslinking system, a low self-polymerizable crosslinking accelerator can also be used. The low self-polymerizable cross-linking accelerator refers to a compound having low self-polymerizability unlike triallyl isocyanurate (TAIC), which is well known as a cross-linking accelerator.

で示されるトリメタリルイソシアヌレート（ＴＭＡＩＣ）、

で示されるｐ−キノンジオキシム（ｐ−ｑｕｉｎｏｎｅｄｉｏｘｉｍｅ）、

で示されるｐ，ｐ’−ジベンゾイルキノンジオキシム（ｐ，ｐ’−ｄｉｂｅｎｚｏｙｌｑｕｉｎｏｎｅｄｉｏｘｉｍｅ）、

で示されるマレイミド、

で示されるＮ−フェニレンマレイミド、

で示されるＮ，Ｎ’−フェニレンビスマレイミド等が挙げられる。 As a low self-polymerization crosslinking accelerator, for example,

Trimethallyl isocyanurate (TMAIC) represented by

P-quinonedioxime represented by the formula:

P, p′-dibenzoylquinone dioxime represented by the formula (p, p′-dibenzoylquinonedioxime),

Maleimide represented by

N-phenylenemaleimide represented by

N, N′-phenylene bismaleimide represented by

A preferred low self-polymerization crosslinking accelerator is trimethallyl isocyanurate (TMAIC).

Bis-olefins can also be used as the crosslinking accelerator used in the peroxide crosslinking system.

Examples of the bisolefin that can be used as a crosslinking accelerator include a formula:
^{R 2 R 3 C = CR 4} -Z-CR 5 = CR 6 R 7
(In the formula, R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different, and all are H or an alkyl group having 1 to 5 carbon atoms; Z is linear (linear ) Or a branched bisolefin which may contain an oxygen atom and which is an at least partially fluorinated alkylene or cycloalkylene group having 1 to 18 carbon atoms or (per) fluoropolyoxyalkylene group) Is mentioned.

Z is preferably a C 4-12 perfluoroalkylene group, and R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are preferably hydrogen atoms.

When Z is a (per) fluoropolyoxyalkylene group,
_{- (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 having 1 to 10 carbon atoms, p is 0 or 1, m and n have an m / n ratio of 0.2 to 5, and the (per) fluoropoly It is preferably a (per) fluoropolyoxyalkylene group represented by the following formula: oxyalkylene group having a molecular weight of 500 to 10,000, preferably 1000 to 4000. In this formula, Q is preferably selected from —CH ₂ OCH ₂ — and —CH ₂ O (CH ₂ CH ₂ O) _s CH ₂ — (s = 1 to 3).

Preferred bisolefins include
_{CH 2 = CH- (CF 2)} 4 -CH = CH 2,
_{CH 2 = CH- (CF 2)} 6 -CH = CH 2,
^{_{Formula: CH 2 = CH-Z 1}} -CH = CH 2
(In the formula, Z ¹ represents —CH ₂ OCH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _m — (CF ₂ O) _n —CF ₂ —CH ₂ OCH ₂ — (m / n is 0.5)). )
Etc.

Among _{them, CH 2 = CH- (CF 2} ) 6 represented by -CH = CH ₂ 3,3,4,4,5,5,6,6,7,7,8,8- dodecafluoro -1, 9-decadiene is preferred.

Further, from the viewpoint of crosslinkability, the fluororubber (A) suitable for the peroxide crosslinking system is preferably a fluororubber containing iodine atoms and / or bromine atoms as crosslinking points. The iodine atom and / or bromine atom content is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, and particularly preferably 0.1 to 3% by mass from the viewpoint of a good balance of physical properties. .

As a compounding quantity of a peroxide crosslinking agent, it is preferable that it is 0.01-10 mass parts with respect to 100 mass parts of fluororubber (A), More preferably, it is 0.1-9 mass parts, Especially preferably, 0.2 to 8 parts by mass. When the peroxide crosslinking agent is less than 0.01 parts by mass, the crosslinking of the fluororubber (A) tends not to proceed sufficiently, and when it exceeds 10 parts by mass, the balance of physical properties tends to decrease.

Moreover, the compounding quantity of a crosslinking accelerator is 0.01-10 mass parts normally with respect to 100 mass parts of fluororubbers (A), Preferably it is 0.1-9 mass parts. If the crosslinking accelerator is less than 0.01 parts by mass, it tends to be undercure, and if it exceeds 10 parts by mass, the physical property balance tends to be lowered.

(Polyol crosslinking system)
Crosslinking by a polyol crosslinking system is preferable in that it has a carbon-oxygen bond at the crosslinking point, has a small compression set, and is excellent in moldability.

As the polyol crosslinking agent, a compound conventionally known as a crosslinking agent for fluororubber can be used. For example, a polyhydroxy compound, particularly 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) Trafluorodichloropropane, 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.

Among these, the polyhydroxy compound is preferable from the viewpoint that the compression set of the obtained crosslinked product is small and the moldability is excellent, the polyhydroxy aromatic compound is more preferable because of excellent heat resistance, and bisphenol AF is further preferable.

Moreover, in a polyol crosslinking system, it is usually preferable to include a crosslinking accelerator. When a crosslinking accelerator is used, the crosslinking reaction can be promoted by promoting the formation of intramolecular double bonds in the dehydrofluorination reaction of the fluororubber main chain and the addition of polyhydroxy compounds to the generated double bonds. it can.

An onium compound is generally used as a crosslinking accelerator for a polyol crosslinking system. The onium compound is not particularly limited, and examples thereof include ammonium compounds such as quaternary ammonium salts, phosphonium compounds such as quaternary phosphonium salts, oxonium compounds, sulfonium compounds, cyclic amines, and monofunctional amine compounds. Of these, quaternary ammonium salts and quaternary phosphonium salts are preferred.

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. .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-phenylpropiyl ) -1,8-diazabicyclo [5.4.0] -7-undecenium chloride and the like. Among these, DBU-B is preferable from the viewpoint of crosslinkability and physical properties of the cross-linked product.

The quaternary phosphonium salt is not particularly limited. For example, tetrabutylphosphonium chloride, benzyltriphenylphosphonium chloride (hereinafter referred to as BTPPC), benzyltrimethylphosphonium chloride, benzyltributylphosphonium chloride, tributylallylphosphonium chloride, tributyl. -2-Methoxypropylphosphonium chloride, benzylphenyl (dimethylamino) phosphonium chloride, and the like can be mentioned. Among these, benzyltriphenylphosphonium chloride (BTPPC) is preferable from the viewpoint of crosslinkability and physical properties of the crosslinked product.

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

As a compounding quantity of a polyol crosslinking agent, it is preferable that it is 0.01-10 mass parts with respect to 100 mass parts of fluororubber (A), More preferably, it is 0.1-7 mass parts. When the polyol crosslinking agent is less than 0.01 part by mass, the crosslinking of the fluororubber (A) tends not to proceed sufficiently, and when it exceeds 10 parts by mass, the balance of physical properties tends to be lowered.

Moreover, it is preferable that the compounding quantity of a crosslinking accelerator is 0.01-8 mass parts with respect to 100 mass parts of fluororubber (A), More preferably, it is 0.02-5 mass parts. When the crosslinking accelerator is less than 0.01 parts by mass, the crosslinking of the fluororubber (A) tends not to proceed sufficiently, and when it exceeds 8 parts by mass, the balance of physical properties tends to decrease.

(Polyamine crosslinking system)
When crosslinked by polyamine crosslinking, it has a carbon-nitrogen double bond at the crosslinking point and is characterized by excellent dynamic mechanical properties. However, the compression set of the crosslinked product tends to increase as compared with the case of crosslinking using a polyol crosslinking system or a peroxide crosslinking system crosslinking agent.

Examples of the polyamine-based crosslinking agent include polyamine compounds such as hexamethylenediamine carbamate, N, N′-dicinnamylidene-1,6-hexamethylenediamine, and 4,4′-bis (aminocyclohexyl) methanecarbamate. Among these, N, N′-dicinnamylidene-1,6-hexamethylenediamine is preferable.

As a compounding quantity of a polyamine type crosslinking agent, it is preferable that it is 0.01-10 mass parts with respect to 100 mass parts of fluororubber (A), More preferably, it is 0.2-7 mass parts. When the polyamine crosslinking agent is less than 0.01 parts by mass, the crosslinking of the fluororubber (A) tends not to proceed sufficiently. When the polyamine crosslinking agent exceeds 10 parts by mass, the balance of physical properties tends to decrease.

In the present invention, a peroxide crosslinking system or a polyol crosslinking system is preferable as the crosslinking system, and it is preferable to use a crosslinking agent (C) suitable for each crosslinking system. Among these, it is more preferable to use a peroxide crosslinking type crosslinking agent.

In the fluororubber composition in the present invention, an ordinary rubber compound, for example, a filler, a processing aid, a plasticizer, a colorant, a tackifier, an adhesion aid, an acid acceptor, a pigment, and a flame retardant is used as necessary. , Lubricants, light stabilizers, weathering stabilizers, antistatic agents, UV absorbers, antioxidants, release agents, foaming agents, fragrances, oils, softeners, polyethylene, polypropylene, polyamide, polyester, polyurethane, etc. You may mix | blend other polymers etc. in the range which does not impair the effect of this invention.
Examples of the fluororubber composition include dicarboxylic acid diesters disclosed in WO 2010/120745, alkali metal silicates disclosed in WO 2010/007699, and WO 2004/067618. Hydrotalcite compounds disclosed in No. Pamphlet and International Publication No. 2007/135937 Pamphlet may be added.

Fillers include metal oxides such as titanium oxide; silicates such as magnesium silicate, calcium silicate, sodium silicate, potassium silicate, lithium silicate, and aluminum silicate; aluminum sulfate, calcium sulfate, and barium sulfate. Sulfates such as: Molybdenum disulfide, iron sulfide, copper sulfide and other metal sulfides; diatomaceous earth, asbestos, lithopone (zinc sulfide / barium sulfide), graphite, carbon fluoride, calcium fluoride, coke, quartz fine powder , Talc, mica powder, wollastonite, carbon fiber, aramid fiber, various whiskers, glass fiber, organic reinforcing agent, organic filler, polytetrafluoroethylene, mica, acidic silica, basic silica, celite, clay, etc. it can. Examples of the acid-accepting agent include calcium oxide, magnesium oxide, lead oxide, zinc oxide, magnesium hydroxide, aluminum hydroxide, hydrotalcite and the like. You may mix | blend a seed | species or more suitably. These are kneading methods to be described later, and it is optional in which step they are added. However, they are added when the fluororubber (A) and carbon black (B) are kneaded in a closed kneader or roll kneader. preferable.

As processing aids, 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; oleic acid Higher fatty acid esters such as ethyl; Petroleum waxes such as carnauba wax and ceresin wax; Polyglycols such as ethylene glycol, glycerin and diethylene glycol; Aliphatic hydrocarbons such as petrolatum and paraffin; Silicone oils, silicone polymers, low molecular weight polyethylene , Phthalates, phosphates, rosin, (halogenated) dialkylamines, surfactants, sulfone compounds, fluorine-based auxiliaries, organic amine compounds, and the like, as long as the effects of the present invention are not impaired, These alone or Two or more may be appropriately blended.

Among them, the organic amine compound and the acid acceptor are preferably blended from the viewpoint that the reinforcing property is improved by coexisting the fluororubber (A) and the carbon black (B) in a closed kneader or a roll kneader. It is an agent.

Preferred examples of the organic amine compound include a primary amine represented by R ¹ NH ₂ , a secondary amine represented by R ¹ R ² NH, and a tertiary amine represented by R ¹ R ² R ³ N. R ¹ , R ² , and R ³ are the same or different, and all are preferably an alkyl group having 1 to 50 carbon atoms, and the alkyl group may contain a benzene ring as a functional group, a double bond, a conjugated double Bonds may be included. The alkyl group may be linear or branched.

Examples of the primary amine include coconut amine, octylamine, laurylamine, stearylamine, oleylamine, beef tallow amine, 17-phenyl-heptadecylamine, octadec-7,11-dienylamine, octadec-7,9-dienylamine, octadec- 9-enylamine, 7-methyl-octadec-7-enylamine, and the like. Examples of the secondary amine include distearylamine, and examples of the tertiary amine include dimethyloctylamine, dimethyldecylamine, dimethyllaurylamine, Examples include dimethyl myristyl amine, dimethyl palmityl amine, dimethyl stearyl amine, and dimethyl behenyl amine. Of these, amines having about 20 carbon atoms, particularly primary amines, are preferred from the standpoint of easy availability and reinforcement.

As for the compounding quantity of an organic amine compound, 0.01-5 mass parts is preferable with respect to 100 mass parts of fluororubber (A). When the amount of the organic amine compound is too large, kneading tends to be difficult, and when the amount is too small, the reinforcing property tends to be lowered. A more preferable blending amount is 0.1 parts by mass or more with respect to 100 parts by mass of the fluororubber (A) from the viewpoint of reinforcement, and 4 parts by mass or less from the viewpoint of reinforcement and ease of kneading. .

Among the acid acceptors, for example, metal oxides such as magnesium oxide and zinc oxide, hydrotalcite and the like are preferable from the viewpoint of reinforcing properties, and zinc oxide is particularly preferable. In particular, in the case of a polyol crosslinking system, magnesium oxide and hydrotalcite are preferable.
When using magnesium oxide as the acid acceptor, it is preferable to further add an alkali metal silicate or basic silica. As a result, the polyol-crosslinked fluororubber in the present invention has excellent biodiesel fuel resistance.

As for the compounding quantity of an acid acceptor, 0.01-10 mass parts is preferable with respect to 100 mass parts of fluororubbers (A). If the acid acceptor is too much, the physical properties tend to be lowered, and if it is too little, the reinforcing property tends to be lowered. A more preferable blending amount is 0.1 parts by mass or more with respect to 100 parts by mass of the fluororubber (A) from the viewpoint of reinforcement, and 6 masses from the viewpoint of physical properties, biodiesel resistance and ease of kneading. Is even more preferable, and 5 parts by mass or less is particularly preferable.
Moreover, it is also preferable that the fluororubber composition in this invention does not contain an acid acceptor from a viewpoint of improving the biodiesel fuel resistance of crosslinked fluororubber.

In order to obtain the crosslinked fluororubber in the present invention, as a fluororubber composition, for example, dynamic in a dynamic viscoelasticity test (measurement temperature: 100 ° C., measurement frequency: 1 Hz) with an uncrosslinked rubber by a rubber process analyzer (RPA). Difference δG ′ (G ′ (1%) − G ′ (100%)) between the shear elastic modulus G ′ (1%) at a strain of 1% and the shear elastic modulus G ′ (100%) at a dynamic strain of 100% However, what is 120 kPa or more and 3000 kPa or less can be used conveniently.

The difference δG ′ is used as an index for evaluating the reinforcing property of the rubber composition, and is measured and calculated by a dynamic viscoelasticity test using a rubber process analyzer (RPA).

A fluororubber composition having a difference δG ′ in the range of 120 kPa to 3000 kPa is advantageous in terms of normal properties, tensile properties at high temperatures, crack resistance, and the like.

The difference δG ′ is preferably 150 kPa or more, more preferably 160 kPa or more, still more preferably 300 kPa or more, and even more preferably 400 kPa or more, from the viewpoint of good normal physical properties, high temperature tensile properties, crack resistance, and the like. Particularly preferably, it is 500 kPa or more, and preferably 2800 kPa or less, more preferably 2500 kPa or less, from the viewpoints of normal properties, hardness, viscosity at the time of extrusion molding, tensile properties at high temperature, crack resistance, and the like.

The fluororubber composition in the present invention can be produced using, for example, a closed kneader or a roll kneader.
Specifically, it is preferably produced by the following production method (1) in that a fluororubber composition giving a cross-linked product excellent in tensile properties and crack resistance at higher temperatures can be obtained.

(1) Step of obtaining an intermediate composition by kneading fluororubber (A) and carbon black (B) with a closed kneader or a roll kneader until the maximum temperature reaches 80 to 220 ° C. (1-1) And the step (1-2) of cooling the intermediate composition until it becomes less than 50 ° C., and the cooled intermediate composition is kneaded until the maximum temperature reaches 10 ° C. or more and less than 80 ° C., and the fluororubber composition (2-1).

Step (1-1) is a step of obtaining an intermediate composition by kneading fluororubber (A) and carbon black (B) until the maximum temperature reaches 80 to 220 ° C.

Step (1-1) is characterized by kneading fluororubber (A) and carbon black (B) at high temperature. By passing through the step (1-1), it is possible to produce a fluororubber composition that gives a crosslinked fluororubber excellent in tensile properties and crack resistance at high temperatures.

The kneading in the step (1-1) is performed with a closed kneader or a roll kneader. The kneading in the step (1-1) is preferably carried out with a closed kneader in that kneading at a high temperature is possible. Examples of the closed kneader include a tangential closed kneader such as a Banbury mixer, a mesh type closed kneader such as an intermix, a pressure kneader, a uniaxial kneader, and a biaxial kneader.

When using a closed kneader, the average shear rate of the rotor is preferably 20 to 1000 (1 / second), more preferably 50 to 1000 (1 / second), and 100 to 1000 (1 / Second), more preferably 200 to 1000 (1 / second), and particularly preferably 300 to 1000 (1 / second).

The average shear rate (1 / second) is calculated by the following formula.
Average shear rate (1 / second) = (π × D × R) / (60 (second) × c)
(Where
D: Rotor diameter or roll diameter (cm)
R: Rotational speed (rpm)
c: Chip clearance (cm. Distance between rotor and casing, or distance between rolls)

In the step (1-1), a crosslinking agent (C) and / or a crosslinking accelerator (D) may be further kneaded. In particular, when the crosslinking system is a polyol crosslinking system, it is preferable to further knead the crosslinking agent (C) and / or the crosslinking accelerator (D) in the step (1-1). The fluororubber (A), the carbon black (B), the cross-linking agent (C) and / or the cross-linking accelerator (D) may be simultaneously put into a closed kneader and kneaded. Carbon black (B) may be kneaded after kneading the crosslinking agent (C) and / or the crosslinking accelerator (D).
In the step (1-1), it is also preferable to knead an organic amine compound and / or an acid acceptor.

The kneading in the step (1-1) is performed until the maximum temperature of the kneaded product during kneading reaches 80 to 220 ° C. The kneading is preferably performed until the maximum temperature reaches 120 ° C. or higher, and is preferably performed until the maximum temperature reaches 200 ° C. or lower. The maximum temperature can be grasped by measuring the temperature of the kneaded material immediately after being discharged from the kneader.

In the said manufacturing method (1), a process (1-2) is a process of cooling the intermediate composition obtained by the process (1-1) until it becomes less than 50 degreeC. Although the temperature of the intermediate composition obtained in the step (1-1) is 80 to 220 ° C., the intermediate composition is sufficiently cooled and then subjected to the step (2-1), whereby the tensile force at high temperature is increased. A fluororubber composition that provides a cross-linked fluororubber having excellent characteristics and crack resistance can be produced. In the step (1-2), it is preferable to cool the entire intermediate composition so that the temperature is in the above-described range. The lower limit of the cooling temperature is not particularly limited, but may be 10 ° C.

In the step (1-2), it is also preferable to cool the intermediate composition while kneading using a roll kneader.

Step (1-1) and step (1-2) may be repeated any number of times. In the step (1-1) and the step (1-2) when repeating, it is preferable to knead the intermediate composition until the maximum temperature reaches 120 to 220 ° C, and the intermediate composition until the maximum temperature reaches 120 to 140 ° C. More preferably, the product is kneaded. When the step (1-1) and the step (1-2) are repeated, the kneading may be performed with a closed kneader or a roll kneader, but is preferably performed with a closed kneader.

When using a roll kneader, the average shear rate of the rotor is preferably 20 (1 / second) or more, more preferably 50 (1 / second) or more, and 100 (1 / second) or more. Is more preferably 200 (1 / second) or more, particularly preferably 300 (1 / second) or more, and is preferably 1000 (1 / second) or less.

The production method (1) preferably includes a step of charging the fluororubber (A) and the carbon black (B) into a closed kneader or a roll kneader, preferably a closed kneader. In the above step, a crosslinking agent (C) and / or a crosslinking accelerator (D) may be added, or an organic amine compound and / or an acid acceptor may be added.

The step (1-1) may include a step of adding an arbitrary additive until the intermediate composition is discharged. As this additive, 1 type (s) or 2 or more types can be used. The number of times of insertion may be one time or multiple times. When adding two or more kinds of additives, they may be added simultaneously or in separate times. One kind of additive may be added a plurality of times. Examples of the “step of adding an arbitrary additive until the intermediate composition is discharged” include, for example, carbon black (B ′) different from the carbon black (B) initially input in step (1-1). Can be included until the intermediate composition is discharged.

Even when the step (1-1) and the step (1-2) are repeated, each step (1-1) includes the above-described “step of adding an arbitrary additive until the intermediate composition is discharged”. May be included. For example, in the second step (1-1), carbon black (B ′) different from the carbon black (B) used in the first step (1-1) may be further added.

In the production method (1), step (2-1) is a step of kneading the cooled intermediate composition obtained in step (1-2) to obtain a fluororubber composition.

The step (2-1) is a step of further kneading the intermediate composition sufficiently cooled in the step (1-2), in order to improve the high temperature tensile properties and crack resistance of the crosslinked fluororubber. This is an important process.

The kneading in the step (2-1) is preferably performed until the maximum temperature of the composition reaches 10 ° C. or more and less than 80 ° C. If the maximum temperature of the composition during kneading is too high, it may not be possible to obtain a fluororubber composition that gives a cross-linked fluororubber having excellent tensile properties and crack resistance at high temperatures.

Step (2-1) may include a step of kneading the cooled intermediate compositions obtained in step (1-2). The kneading in this case may be performed until the maximum temperature of the mixture of different intermediate compositions reaches 10 ° C. or more and less than 80 ° C.

In the production method (1), after the step (2-1) is performed, the step (2-2) is further repeated m-1 times (m is an integer of 2 or more). It is preferable to include. By carrying out the step (2-1) twice or more in total, a fluororubber composition that gives a cross-linked fluororubber excellent in tensile properties and crack resistance at high temperatures can be stably produced. M is preferably an integer of 5 or more, more preferably an integer of 10 or more, still more preferably an integer of 30 or more, and particularly preferably an integer of 50 or more. It is also preferable to include a step of cooling the intermediate composition before each kneading in step (2-2).

The kneading in the step (2-1) and the step (2-2) can be performed with the above-described closed kneader or roll kneader.

The step (2-1) and the step (2-2) are preferably steps for kneading the intermediate composition by putting the intermediate composition into a roll kneader and performing thinning.

FIG. 1 schematically shows a kneading method by thin threading. As shown in FIG. 1A, the intermediate composition 13 is put into an open roll 10 that includes a first roll 11 and a second roll 12. The first roll 11 and the second roll 12 rotate at different speeds in the directions of the arrows. Next, as shown in FIG. 1B, the charged intermediate composition 13 is separated into a sheet by passing between the first roll 11 and the second roll 12 while receiving a shearing force. After taking out, as shown in FIG.1 (c), the composition 14 after taking out is wound up in arbitrary places.

The step (2-1) and the step (2-2) are obtained in the step (2-1) from the viewpoint of obtaining a fluororubber composition that gives a crosslinked fluororubber excellent in tensile properties and crack resistance at high temperatures. The value (P) of G ′ (1%) / G ′ (100%) of the fluororubber composition and the fluororubber composition obtained in the step (2-2) is the intermediate composition obtained in the step (1-2). The value (P / Q) obtained by dividing by the value (Q) of G ′ (1%) / G ′ (100%) of the product is 0.3 to 1.5. It is more preferable to carry out so that it may become 1.3 or less, It is still more preferable to carry out so that it may become 1.0 or less, It is especially preferable to carry out so that it may become less than 1.0, 0 It is even more preferable to carry out so that it becomes 9 or less.

Shear modulus G ′ (1%) at 1% dynamic strain and ratio of shear modulus G ′ (1%) and shear modulus G ′ (100%) at 100% dynamic strain (G ′ ( 1%) / G ′ (100%)) is a dynamic value measured at 100 ° C. and 1 Hz after preheating at 100 ° C. for 1 minute using a rubber process analyzer (model: RPA2000) manufactured by Alpha Technologies. It can be calculated from viscoelasticity.

Although it is possible to improve the tensile properties and crack resistance at high temperatures of the cross-linked product even with a single pass, in order to achieve further excellent tensile properties and crack resistance at high temperatures, It is preferable to perform m times (m is an integer of 2 or more). M is preferably an integer of 5 or more, more preferably an integer of 10 or more, still more preferably an integer of 30 or more, and particularly preferably an integer of 50 or more.

In the production method (1), the fluororubber composition obtained in the step (2-1) or the step (2-2), and the crosslinking agent (C) and / or the crosslinking accelerator (D) are further kneaded. It is also preferable to include the process of carrying out. As described above, the crosslinking agent (C) and / or the crosslinking accelerator (D) may be kneaded in the step (1-1). When the crosslinking system is a peroxide crosslinking system, the step (2-1) or the step (2-2) is carried out without kneading the crosslinking agent (C) and the crosslinking accelerator (D) in the step (1-1). It is preferable to knead the fluororubber composition obtained in (1) with the crosslinking agent (C) and / or the crosslinking accelerator (D).

The crosslinking agent (C) and the crosslinking accelerator (D) may be blended and kneaded simultaneously, or the crosslinking accelerator (D) may be blended and kneaded first, and then the crosslinking agent (C) may be blended and kneaded. When kneading in the step (1-1), the kneading conditions of the crosslinking agent (C) and the crosslinking accelerator (D) are the same as the above-described step (1-1) except that the maximum kneading temperature is 130 ° C. or less. The same conditions may be used. Among them, the average rotor speed is 20 (1 / second) or more, preferably 50 (1 / second) or more, more preferably 100 (1 / second) or more, further preferably 200 (1 / second) or more, particularly preferably. Is preferably kneaded using an open roll, a closed kneader, or the like with 300 (1 / second) or more. When the fluororubber composition obtained in the step (2-1) or the step (2-2) and the crosslinking agent (C) and / or the crosslinking accelerator (D) are kneaded, the maximum temperature is less than 130 ° C. It is preferable to knead so that.

In addition to the production method (1), for example, the following production method (2) can also be employed.

(2) Fluorine rubber (A) and carbon black (B), if necessary, an organic amine compound and / or an acid acceptor are charged in a closed kneader or roll kneader, and the average shear rate of the rotor is 20 ( 1 / second) or more, preferably 50 (1 / second) or more, more preferably 100 (1 / second) or more, still more preferably 200 (1 / second) or more, particularly preferably 300 (1 / second) or more. Kneading under the condition that the maximum temperature Tm is 80 to 220 ° C. (preferably 120 to 200 ° C.). The kneading in the production method (2) is preferably carried out with a closed kneader in that kneading at a high temperature is possible.

The fluororubber composition obtained by the method (2) does not contain a crosslinking agent (C), a crosslinking accelerator (D), or the like. The kneading in the method (2) may be performed a plurality of times. In the case of performing a plurality of times, the second and subsequent kneading conditions may be the same conditions as in the above method (2) except that the maximum kneading temperature Tm is 140 ° C. or lower.

One of the methods for preparing the fluororubber composition in the present invention based on the production method (2) is, for example, obtained by the method (2) or obtained by repeating the method (2) a plurality of times. In the obtained fluororubber composition, a crosslinking agent (C) and / or a crosslinking accelerator (D) is further blended and kneaded.

The crosslinking agent (C) and the crosslinking accelerator (D) may be blended and kneaded simultaneously, or the crosslinking accelerator (D) may be blended and kneaded first, and then the crosslinking agent (C) may be blended and kneaded. The kneading conditions for the cross-linking agent (C) and the cross-linking accelerator (D) may be the same as the above method (2) except that the maximum kneading temperature Tm is 130 ° C. or less.

Another preparation method of the fluororubber composition in the present invention is, for example, a fluorokneader (A) and carbon black (B), a crosslinking agent (C) and / or a crosslinking accelerator (D) in an appropriate order in a roll kneader. A predetermined amount is charged, and the average shear rate of the rotor is 20 (1 / second) or more, preferably 50 (1 / second) or more, more preferably 100 (1 / second) or more, and further preferably 200 (1 / second) or more. Particularly preferred is a method of kneading under conditions of 300 (1 / second) or more and a maximum kneading temperature Tm of 130 ° C. or less.

In the case of a polyol crosslinking system, a uniform dispersion may be used by previously mixing the fluororubber (A), the crosslinking agent (C) and the crosslinking accelerator (D). For example, the fluororubber (A), the polyol-based crosslinking agent, and the crosslinking accelerator are first kneaded, and then carbon black and an organic amine compound described later are blended and kneaded so that the maximum kneading temperature Tm is 80 to 220 ° C. Finally, there is a method in which an acid acceptor is blended and kneaded so that the maximum temperature Tm of kneading is 130 ° C. or less. In kneading, the average shear rate is 20 (1 / second) or more (preferably 50 (1 / second) or more, more preferably 100 (1 / second) or more, further preferably 200 (1 / second) or more, particularly It is more preferable to employ a method of kneading at 300 (1 / second) or more.

The biodiesel-resistant fuel member of the present invention comprises a crosslinked fluororubber obtained by crosslinking the fluororubber composition.

In the present invention, the method for crosslinking and molding the fluororubber composition may be appropriately selected, but a method using a general rubber molding machine can be employed. As the rubber molding machine, a compression press, an injection molding machine, an injection molding machine, etc. can be used, and a rubber composition preformed into a predetermined shape using a roll, a kneading machine, an extruder, a preforming machine, etc. Primary crosslinking is performed by heating. In addition, a crosslinking method using a crosslinking can or the like, or a molding method such as extrusion molding or roll steaming can be employed. When secondary crosslinking is required for the purpose of use, the crosslinked product obtained by the above method may be further crosslinked using an oven or the like.

The cross-linked fluororubber in the present invention has a dynamic viscoelasticity test (measurement mode: tensile, chuck-to-chuck distance: 20 mm, tensile strain: 1%, measurement frequency: 10 Hz, static load condition at the time of strain dispersion is constant force) At a static tension value of 157 cN and a measurement temperature of 160 ° C., the loss elastic modulus E ″ is 400 kPa or more and 6000 kPa or less. This is particularly excellent in normal properties, tensile properties at high temperatures, crack resistance, and the like.

The lower limit is preferably 420 kPa, more preferably 430 kPa, still more preferably 500 kPa, particularly preferably 1000 kPa, particularly preferably 1500 kPa, and the upper limit is preferably 5900 kPa, more preferably 5800 kPa.

Cross-linked fluororubber is a dynamic viscoelasticity test (measurement mode: tensile, chuck-to-chuck distance: 20 mm, measurement temperature: 160 ° C., tensile strain: 1%, static load condition at the time of strain dispersion is constant force) It is more preferable that the storage elastic modulus E ′ is 1500 kPa or more and 20000 kPa or less at a high tensile strength and crack resistance at a static tension value of 157 cN and a frequency of 10 Hz. The lower limit is preferably 1600 kPa, more preferably 1800 kPa, still more preferably 2000 kPa, particularly preferably 3000 kPa, and even more preferably 4000 kPa, and the upper limit is preferably 19000 kPa, more preferably 18000 kPa.

The crosslinked fluororubber has a tensile elongation at break of 100 to 700%, further 110% or more, particularly 120% or more, and 680% or less, particularly 650% or less at 160 ° C. in a high temperature environment. It is preferable because it is suitable for use below.

Further, the crosslinked fluororubber has a tensile strength at 160 ° C. of 1 MPa or more, further 1.5 MPa or more, particularly 2 MPa or more, and 30 MPa or less, particularly 28 MPa or less. It is preferable because it is suitable for the above. The tensile breaking strength and the tensile breaking elongation are measured using a No. 6 dumbbell according to JIS-K6251.

The crosslinked fluororubber has a tear strength of 3 to 30 kN / m, further 4 kN / m or more, particularly 5 kN / m or more, and 29 kN / m or less, particularly 28 kN / m or less at 160 ° C. Is preferable because it is suitable for use in a high-temperature environment.

The crosslinked fluororubber has a tensile elongation at break of 100 to 700%, further 110% or more, particularly 120% or more, and 680% or less, particularly 650% or less at 200 ° C. It is preferable because it is suitable for use below.

The crosslinked fluororubber has a tensile strength at 200 ° C. of 1 to 25 MPa, more preferably 1.5 MPa or more, particularly 2 MPa or more, and 20 MPa or less, particularly 15 MPa or less in a high temperature environment. This is preferable because it is suitable for use.

The crosslinked fluororubber has a tear strength of 3 to 30 kN / m, further 4 kN / m or more, particularly 5 kN / m or more, and 29 kN / m or less, particularly 28 kN / m or less at 200 ° C. Is preferable because it is suitable for use in a high-temperature environment.

Since the biodiesel fuel member of the present invention is composed of the above-mentioned crosslinked fluororubber, it is particularly excellent in tensile properties and crack resistance at high temperatures in the environment where biodiesel fuel is used. From the viewpoint of making the effects of the present invention more remarkable, in the biodiesel-resistant fuel member of the present invention, it is preferable that the contact portion with the biodiesel fuel is the above-mentioned crosslinked fluororubber.

The use of the above-mentioned crosslinked fluororubber for contacting with biodiesel fuel is also one aspect of the present invention.

The biodiesel-resistant fuel member of the present invention is preferably used in an environment where the maximum temperature is 80 ° C. or higher. Even under such a high temperature environment, the biodiesel fuel member of the present invention exhibits excellent tensile properties and crack resistance. As said maximum temperature, More preferably, it is 90 degreeC or more, More preferably, it is 100 degreeC or more.

The use of the crosslinked fluororubber in an environment where the maximum temperature is 80 ° C. or higher is also one aspect of the present invention.

The biodiesel-resistant fuel member of the present invention can be used for various applications in contact with biodiesel fuel. For example, hoses such as films, seats, automobile fuel hoses, refueling hoses, underground buried tubes for gasoline stations, bottles for fuel tanks for automobiles, containers, tanks, diaphragms, packing, carburetor flange gaskets, fuel pumps, etc. It can be used for various automotive seals such as O-rings and various mechanical seals such as hydraulic equipment seals.
The biodiesel-resistant fuel member of the present invention is preferably a hose or a sealing material, more preferably a hose, among the above-mentioned members.

The hose of the present invention may be a hose having a single layer structure made of only the above-mentioned crosslinked fluororubber, or a multilayer hose having a laminated structure with other layers.

Examples of the single layer hose include an exhaust gas hose, an EGR hose, a turbocharger hose, and a fuel hose.

Examples of the multi-layered hose include an exhaust gas hose, an EGR hose, a turbocharger hose, and a fuel hose.

A turbo system is often installed in a diesel engine. By sending exhaust gas from the engine to the turbine and rotating it, the compressor connected to the turbine is moved to increase the compression ratio of the air supplied to the engine and improve the output. It is. This turbo system, which uses engine exhaust gas and obtains high output, leads to downsizing of the engine, fuel consumption reduction of the automobile, and cleaner exhaust gas.

The turbocharger hose is used in the turbo system as a hose for sending compressed air to the engine. In order to effectively utilize the space in a narrow engine room, a rubber hose with excellent flexibility and flexibility is advantageous, and typically rubber with excellent heat aging resistance and oil resistance (especially fluororubber) ) A hose having a multilayer structure in which the layer is an inner layer and silicone rubber or acrylic rubber is an outer layer is employed. However, the surroundings of the engine such as the engine room are exposed to high temperatures, and particularly when biodiesel fuel is used, the turbocharger hose is pulled even under such high temperature conditions. What is excellent in characteristics and crack resistance is required.

The above hose satisfies these required characteristics at a high level by using the cross-linked fluororubber in the present invention as a single layer and a multilayer rubber layer, and provides a turbocharger hose having excellent characteristics. Can do.

In a hose having a multilayer structure other than the turbocharger hose, examples of the layer made of other materials include a layer made of other rubber, a layer made of a thermoplastic resin, various fiber reinforced layers, a metal foil layer, and the like.

As other rubbers, when chemical resistance and flexibility are particularly required, acrylonitrile-butadiene rubber or its hydrogenated rubber, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, fluorine rubber, epichlorohydrin rubber A rubber comprising at least one selected from the group consisting of EPDM and acrylic rubber is preferable, and acrylonitrile-butadiene rubber or hydrogenated rubber thereof, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, fluorine rubber, epichlorohydrin rubber More preferably, it is made of at least one rubber selected from the group consisting of:

The thermoplastic resin is a heat composed of at least one selected from the group consisting of fluororesins, polyamide resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, polyvinyl chloride resins, and polyphenylene sulfide resins. A plastic resin is preferable, and a thermoplastic resin made of at least one selected from the group consisting of a fluororesin, a polyamide resin, a polyvinyl alcohol resin, and a polyphenylene sulfide resin is more preferable.

Moreover, when producing the hose of a multilayer structure, you may surface-treat as needed. The type of the surface treatment is not particularly limited as long as it is a treatment method that enables adhesion. For example, discharge treatment such as plasma discharge treatment or corona discharge treatment, wet metal sodium / naphthalene liquid treatment Etc. A primer treatment is also suitable as the surface treatment. Primer treatment can be performed according to a conventional method. When the primer treatment is performed, the surface of the fluororubber that has not been subjected to the surface treatment can be treated, but after the plasma treatment, the corona discharge treatment, the metal sodium / naphthalene solution treatment, etc. are applied in advance, the primer treatment is performed. Is more effective.

The hose of the present invention can be suitably used in the following fields.

In the biodiesel fuel automobile field, it can be used as a peripheral device for engines and automatic transmissions, and can be used as an EGR hose, an exhaust gas hose, a fuel hose, etc. in addition to a turbocharger hose.

In addition, it can also be used for hoses in the fields of aircraft, rockets and ships using biodiesel fuel.

The hose may have a corrugated region in the middle thereof. Such a corrugated region is a region in the middle of the hose body that is appropriately formed into a corrugated shape, a corrugated shape, a convoluted shape, or the like.

The hose having the corrugated region has a region where a plurality of corrugated folds are arranged in an annular shape, so that one side of the annular shape can be compressed in the region and the other side can be expanded outward. Therefore, it can be easily bent at any angle without stress fatigue or delamination.

Although the formation method of the corrugated region is not limited, it can be easily formed by using an existing forming method such as first forming a straight tube hose and then molding or the like to obtain a predetermined corrugated shape or the like. it can.

The sealing material of this invention can be used suitably in the field | area shown below.

For example, gaskets in non-contact type and contact type packings (self-seal packing, self-sealing packing, etc.) in engine bodies, main motion systems, valve systems, lubricant / cooling systems, fuel systems, intake / exhaust systems, etc. And sealing materials such as piston rings, split ring type packings, mechanical seals, oil seals, and the like.

The sealing material used for the engine body of the biodiesel fuel automobile engine is not particularly limited. For example, a cylinder head gasket, a cylinder head cover gasket, an oil pan packing, a gasket such as a general gasket, an O-ring, a packing, a timing belt cover Examples thereof include a sealing material such as a gasket.

Although it does not specifically limit as a sealing material used for the main motion system of the engine for biodiesel fuel vehicles, For example, shaft seals, such as a crankshaft seal and a camshaft seal, etc. are mentioned.

The seal material used in the valve system of a biodiesel fuel vehicle engine is not particularly limited, and examples thereof include a valve stem oil seal for an engine valve and a valve seat for a butterfly valve.

Although it does not specifically limit as a sealing material used for the lubricant and cooling system of the engine for biodiesel fuel vehicles, For example, the seal gasket of an engine oil cooler etc. are mentioned.

The seal material used in the engine fuel system for biodiesel fuel automobiles is not particularly limited. For example, an oil seal for a fuel pump, a filler seal for a fuel tank, a tank packing, a connector O-ring for a fuel tube, etc. Injector cushion rings, injector seal rings, injector O-rings, etc. of fuel injection devices, flange gaskets of carburetors, EGR sealing materials, and the like.

The seal material used in the intake / exhaust system of a biodiesel fuel vehicle engine is not particularly limited. For example, an intake manifold packing of a manifold, an exhaust manifold packing, a throttle body packing of a throttle, a turbocharged turbine A shaft seal etc. are mentioned.

The sealing material of the present invention can also be used as a sensor sealing material (bush). For example, it is suitable for a sealing material for an oxygen sensor, a sealing material for a nitrogen oxide sensor, a sealing material for a sulfur oxide sensor, and the like.

The O-ring may be a square ring.

In addition to the biodiesel fuel automobile field, it can be used in various fields where biodiesel fuel is used. For example, it can be widely used in fields such as an aircraft field, a rocket field, and a ship field.

For example, in a transportation system such as a ship or an aircraft that uses biodiesel fuel, packing, an O-ring, and other sealing materials that are used for a portion that comes into contact with the biodiesel resistant fuel can be used.

The sealing material of this invention can be used suitably also as a diaphragm shown below.
For example, the use of biodiesel-fueled automobile engines includes diaphragms such as fuel systems and exhaust systems.
Diaphragms used in the fuel system of biodiesel fuel automobile engines include, for example, fuel pump diaphragms, carburetor diaphragms, pressure regulator diaphragms, pulsation damper diaphragms, ORVR diaphragms, canister diaphragms, auto fuel cock diaphragms, etc. Is mentioned.
Examples of the diaphragm used in the exhaust system of the biodiesel fuel automobile engine include a waste gate diaphragm, an actuator diaphragm, an EGR diaphragm, and the like.

Examples of uses other than biodiesel fuel automobile engines include diaphragms and the like that are used in places that come into contact with biodiesel-resistant fuel in transport engines such as ships and aircraft that use biodiesel fuel.

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

Various physical property measuring methods employed in the present invention are as follows.

(1) Dynamic viscoelasticity test 1 (loss elastic modulus E ″ and storage elastic modulus E ′)
(measuring device)
Dynamic measurement system DVA-220 manufactured by IT Measurement Control Co., Ltd.
(Measurement condition)
Test piece: Cross-linked rubber having a rectangular shape with a width of 3 mm and a thickness of 2 mm Measurement mode: Distance between tensile chucks: 20 mm
Measurement temperature: 160 ° C
Static tension value when the static load condition at the time of strain dispersion is constant force: 157 cN
Frequency: 10Hz
Then, the strain dispersion is measured, and the loss elastic modulus E ″ and the storage elastic modulus E ′ at a tensile strain of 1% are calculated.

(2) Dynamic viscoelasticity test 2 (shear elastic modulus G ′)
(measuring device)
Rubber process analyzer manufactured by Alpha Technologies (model: RPA2000)
(Measurement condition)
The strain dispersion is measured at 100 ° C. and 1 Hz to determine the shear modulus G ′. At this time, G ′ is obtained by setting the dynamic strain to 1% and 100%, respectively, and δG ′ (G ′ (1%) − G ′ (100%)) is calculated.

(3) Mooney viscosity (ML _{1 + 10} (100 ° C.))
The Mooney viscosity is measured according to JIS K6300. The measurement temperature is 100 ° C.

(4) Tensile strength RTG-1310 manufactured by A & D Co., Ltd., and “Strograph” TH-200D manufactured by Toyo Seiki Seisakusho Co., Ltd. are used as the tensile rupture strength and tensile rupture elongation tester. In accordance with JIS-K6251, the tensile strength at break and tensile elongation at break are measured using a dumbbell set at 50 mm between the chucks and a tensile speed of 500 mm / min. Measurement temperature shall be 25 degreeC and 160 degreeC.

(5) Crack resistance test According to JIS-K6262, crack resistance is measured using a large test piece for compression set test. The test apparatus was a compression apparatus used in the JIS-K6262 5-compression set test, and a spacer having a test piece compression ratio of 55% was used. The thing without a crack is set as (circle) and the thing with a crack is set as *.

(6) Biodiesel fuel immersion test (Biodiesel fuel resistance test)
An immersion test is conducted at 125 ° C. for 504 hours on a degraded biodiesel fuel (fuel obtained by adding 2% by volume of water to SME (soybean oil methyl ester) fuel (NEXSOL BD-100 BIODISEL manufactured by PETER CREMER)). The volume of the crosslinked rubber sheet before and after immersion is measured, and the volume change rate (%) is measured.

In Examples and Comparative Examples, various compounding agents such as the following fluororubber, carbon black, crosslinking agent, and crosslinking accelerator were used.

(Fluoro rubber A1)
In an 82 L stainless steel autoclave, pure water 44 L, CH ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH ₄ 50% aqueous solution 8.8 g, F (CF ₂ ) ₅ COONH ₄ 50 A 176 g% aqueous solution was charged, and the inside of the system was sufficiently replaced with nitrogen gas. The temperature was raised to 80 ° C. while stirring at 230 rpm, and then the monomer was injected so that the monomer composition in the initial tank was VdF / HFP = 50/50 (molar ratio) and 1.52 MPa. Then, a polymerization initiator solution in which 1.0 g of ammonium persulfate (APS) was dissolved in 220 ml of pure water was injected with nitrogen gas to initiate the reaction. When the internal pressure dropped to 1.42 MPa as the polymerization progressed, an additional mixed monomer of VdF / HFP = 78/22 (molar ratio) as an additional mixed monomer was injected until the internal pressure became 1.52 MPa. At this time, 70 g of diiodine compound I (CF ₂ ) ₄ I was injected. While repeatedly increasing and decreasing the pressure, an aqueous solution of 1.0 g of APS / 220 ml of pure water was injected with nitrogen gas every 3 hours to continue the polymerization reaction. When 14000 g of mixed monomer was added, unreacted monomers were released, and the autoclave was cooled to obtain a fluororubber dispersion having a solid content concentration of 23.1% by mass. When the copolymer composition of this fluororubber was examined by NMR analysis, it was VdF / HFP = 78/22 (molar ratio), and the Mooney viscosity (ML _{1 + 10} (100 ° C.)) was 65. This fluororubber is referred to as fluororubber A1.

(Fluoro rubber A2)
3L stainless steel autoclave of pure water _{1.7L, CH 2 = CFCF 2 OCF} (CF 3) CF 2 OCF (CF 3) 50% aqueous solution of 0.17g of _{COONH 4, F (CF 2)} 5 COONH 4 6.8 g of a 50% aqueous solution was charged, and the inside of the system was sufficiently replaced with nitrogen gas. The temperature was raised to 80 ° C. while stirring at 600 rpm, and then the monomer was injected so that the initial monomer composition was VdF / HFP = 34/66 (molar ratio) and 1.52 MPa. Then, a polymerization initiator solution in which 60 mg of APS was dissolved in 5 ml of pure water was injected with nitrogen gas to initiate the reaction. When the internal pressure dropped to 1.42 MPa as the polymerization progressed, an additional mixed monomer of VdF / HFP = 68/32 (molar ratio) as an additional mixed monomer was injected until the internal pressure became 1.52 MPa. At this time, 1.96 g of diiodine compound I (CF ₂ ) ₄ I was injected. While repeatedly increasing and decreasing the pressure, an aqueous solution of 60 mg of APS / 5 ml of pure water was injected with nitrogen gas every 3 hours to continue the polymerization reaction. When 600 g of the mixed monomer was added, unreacted monomers were released, and the autoclave was cooled to obtain 2346 g of a fluororubber dispersion having a solid content concentration of 26.3 mass%. The polymerization time was 7.9 hours. When the copolymer composition of this fluororubber was examined by NMR analysis, it was VdF / HFP = 68/32 (molar ratio), and the Mooney viscosity (ML _{1 + 10} (100 ° C.)) was 69. This fluororubber is designated as fluororubber A2.

(Carbon black)
ISAF (N ₂ SA = 119 m ² / g, DBP oil absorption = 114 ml / 100 g). "Seast 6" (trade name) manufactured by Tokai Carbon Co., Ltd.
HAF (N ₂ SA = 79 m ² / g, DBP oil absorption = 101 ml / 100 g). "Seast 3" (trade name) manufactured by Tokai Carbon Co., Ltd.
MT (N ₂ SA = 8 m ² / g, DBP oil absorption = 43 ml / 100 g). “Thermax N990” (trade name) manufactured by Cancarb

(Crosslinking agent)
2,5-Dimethyl-2,5-di (t-butylperoxy) hexane. "Perhexa 25B" (trade name) manufactured by NOF Corporation

(Crosslinking accelerator)
Triallyl isocyanurate (TAIC). “Tyke” (trade name) manufactured by Nippon Kasei Co., Ltd.

(Processing aid)
Stearylamine (Farmin 86T) (manufactured by Kao Corporation)

Example 1
Using a kneading machine (MixLabo 0.5L manufactured by Moriyama Co., Ltd., rotor diameter: 6.6 cm, tip clearance: 0.05 cm), the front rotor rotation speed: 60 rpm, the back rotor rotation speed: 50 rpm, and fluorine 20 parts by mass of ISAF carbon black and 0.5 parts by mass of stearylamine were kneaded with 100 parts by mass of rubber (A1). The temperature of the kneaded product discharged from the kneader was 170 ° C. The kneaded product was cooled and kneaded to a temperature of 100 ° C. or lower with an 8-inch open roll mixer adjusted to 25 ° C., and then discharged. Subsequently, the kneaded product obtained by cooling and kneading was aged at 25 ° C. for 24 hours to obtain a fluororubber pre-compound B1. The difference δG ′ (G ′ (1%) − G ′ (100%)) between the shear elastic modulus G ′ (1%) and the shear elastic modulus G ′ (100%) of the fluororubber pre-compound B1 was 591 kPa. .

Next, using an 8-inch open roll (manufactured by Kansai Roll Co., Ltd.), a fluororubber pre-compound is prepared under a kneading condition of a roll temperature of 25 ° C., a front roll rotation speed of 21 rpm, a back roll rotation speed of 19 rpm, and a roll gap of 0.1 cm. (B1) 120.5 parts by mass, 1.0 part by mass of a crosslinking agent, and 0.5 parts by mass of a crosslinking accelerator were kneaded for 15 minutes to prepare a fluororubber full compound (C1). The temperature of the discharged kneaded material was 71 ° C.

This fluororubber full compound (C1) was pressed at 160 ° C. for 30 minutes for crosslinking to produce a sheet-like test piece having a thickness of 2 mm. Using the obtained crosslinked sheet, the tensile strength at break and the tensile elongation at break were measured. The results are shown in Table 1.

Further, the obtained crosslinked fluororubber was subjected to a dynamic viscoelastic test 1 to determine a loss elastic modulus E ″ and a storage elastic modulus E ′. The results are shown in Table 1.

Table 1 shows the results of a biodiesel fuel immersion test and a crack resistance test performed on the obtained crosslinked fluororubber.

Example 2
A crosslinked fluororubber was prepared in the same manner as in Example 1 except that the amount of TAIC was changed from 0.5 parts by mass to 4.0 parts by mass, and various physical properties were evaluated. The results are shown in Table 1.

Example 3
A crosslinked fluororubber was produced in the same manner as in Example 1 except that the carbon black was changed to HAF carbon black, and various physical properties were evaluated. The results are shown in Table 1.

Example 4
A crosslinked fluororubber was prepared in the same manner as in Example 1 except that the fluororubber was changed to fluororubber A2, and various physical properties were evaluated. The results are shown in Table 1.

Comparative Example 1
A crosslinked fluororubber was prepared in the same manner as in Example 1 except that carbon black was changed to MT carbon black and the amount of TAIC was changed from 0.5 parts by mass to 4.0 parts by mass, and various physical properties were evaluated. The results are shown in Table 1.

10: Open roll 11: First roll 12: Second roll 13: Intermediate composition 14: Composition after dispensing

Claims (9)

A biodiesel fuel-resistant member comprising a crosslinked fluororubber obtained by crosslinking a fluororubber composition containing fluororubber (A) and carbon black (B),
Cross-linked fluororubber has loss elasticity in a dynamic viscoelasticity test (measuring temperature: 160 ° C., tensile strain: 1%, static tension value when the static load condition during strain dispersion is constant force: 157 cN, frequency: 10 Hz). The biodiesel-resistant fuel member having a rate E ″ of 400 kPa or more and 6000 kPa or less. The cross-linked fluororubber has storage elasticity in a dynamic viscoelasticity test (measurement temperature: 160 ° C., tensile strain: 1%, static tension value when the static load condition during strain dispersion is constant force: 157 cN, frequency: 10 Hz). The biodiesel-resistant fuel member according to claim 1, wherein the rate E 'is 1500 kPa or more and 20000 kPa or less. The biodiesel fuel-resistant member according to claim 1 or 2, wherein the fluororubber composition contains 5 to 65 parts by mass of carbon black (B) with respect to 100 parts by mass of the fluororubber (A). The carbon black (B) has a nitrogen adsorption specific surface area (N ₂ SA) of 25 to 180 m ² / g and a dibutyl phthalate (DBP) oil absorption of 40 to 180 ml / 100 g. Anti-biodiesel fuel member. The fluororubber (A) is at least one selected from the group consisting of a vinylidene fluoride copolymer, a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer, and a tetrafluoroethylene / propylene copolymer. The biodiesel-resistant fuel member according to claim 1, 2, 3, or 4. The biodiesel-resistant fuel member according to claim 1, 2, 3, 4, or 5, wherein the fluororubber composition contains a crosslinking agent (C) and / or a crosslinking aid (D). The biodiesel-resistant fuel member according to claim 1, wherein the contact portion with biodiesel fuel is the crosslinked fluororubber. 8. The biodiesel-resistant fuel member according to claim 1, which is used in an environment where the maximum temperature is 80 ° C. or higher. The biodiesel-resistant fuel member according to claim 1, which is a hose or a sealing material.

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