Thermosetting perfluoropolyether rubber composition

Abstract

This heat-curable perfluoropolyether rubber composition contains specific proportions of (A) a perfluoropolyether polymer having a specific structure which has two or more alkenyl groups in the molecular chain thereof, (B) a fluorine-containing organohydrogen polysiloxane which has two or more hydrogen atoms bonded to a silicon atom in each molecule thereof, (C) a hydrosilylation reaction catalyst and (D) a hydrophobic silica powder which has a BET specific surface area of 50m2 / g or higher. As a result, this heat-curable perfluoropolyether rubber composition is capable of producing a cured article (perfluoropolyether rubber cured article) which has excellent heat resistance, chemical resistance, solvent resistance, low-temperature dependence, rubber properties (mechanical strength, elongation properties, etc.) and the like while also exhibiting excellent injection molding properties and mold release properties.

Description

[Technical Field]

[0001] The present invention relates to a thermosetting perfluoropolyether rubber composition that can give a cured product (perfluoropolyether rubber cured product) that is excellent in heat resistance, chemical resistance, solvent resistance, low-temperature properties, and rubber physical properties (mechanical strength, elongation, etc.), and that also has excellent injection moldability and mold releasability. [Background technology]

[0002] In recent years, in the production of rubber molded products, there has been an increasing trend to use injection molding in order to reduce labor through automation, etc. For this reason, there is a demand for rubber compositions that can give cured products that are excellent in heat resistance, chemical resistance, solvent resistance, low-temperature properties, and rubber physical properties (mechanical strength, elongation, etc.), and that can be easily injection molded.

[0003] Patent Document 1 (JP 2002-167502 A) discloses a curable composition that has excellent heat resistance, chemical resistance, solvent resistance, low-temperature properties, etc. However, when attempting to obtain high-strength rubber properties with this composition, depending on the composition, the viscosity can become high, which can make it difficult to mold the cured product using a liquid injection molding system (LIMS).

[0004] Furthermore, in LIMS, in order to increase productivity, it is required that the cured product be easily released from the mold after molding. However, there is room for improvement in the mold releasability of the cured product obtained from the composition disclosed in Patent Document 1.

[0005] In the examples of Patent Document 2 (International Publication No. 2019 / 088132), CH2=CHCH2OCH2CF2(OC2F4) e -(OCF2) fThe document describes a curable composition comprising a perfluoropolyether compound represented by -CF2CH2OCH2CH=CH2 (wherein e=40, f=58), an organosilicon compound having two or more silicon-bonded hydrogen atoms per molecule, and a catalyst. However, the inventors' investigations have revealed that the rubber properties of the cured product of this composition are insufficient. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-167502 [Patent Document 2] International Publication No. 2019 / 088132 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-24695 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thermosetting perfluoropolyether rubber composition that can give a cured product (perfluoropolyether rubber cured product) excellent in heat resistance, chemical resistance, solvent resistance, low-temperature properties, and rubber physical properties (mechanical strength, elongation, etc.), and that also has excellent liquid injection moldability and mold releasability. [Means for solving the problem]

[0008] As a result of intensive research conducted by the present inventors to achieve the above object, they have discovered a method for producing a fluorine-containing organohydrogenpolysiloxane comprising: (A) a perfluoropolyether polymer having at least two alkenyl groups in the molecular chain, represented by the general formula (1) or (2) described below; (B) a fluorine-containing organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule; (C) a hydrosilylation reaction catalyst; and (D) a fluorine-containing organohydrogenpolysiloxane having a BET specific surface area of ​​50 m 2The present inventors have found that a thermosetting perfluoropolyether rubber composition containing a specific proportion of hydrophobic silica powder having a hydrophobicity of 1 / g or more is excellent in injection moldability and mold releasability, and that the resulting cured product (cured perfluoropolyether rubber product) is excellent in heat resistance, chemical resistance, solvent resistance, low-temperature properties, and rubber physical properties (mechanical strength, elongation, etc.), and have thus completed the present invention.

[0009] Accordingly, the present invention provides the following thermosetting perfluoropolyether rubber composition. [1] (A) a perfluoropolyether polymer having at least two alkenyl groups in the molecular chain, represented by the following general formula (1) or (2): 100 parts by mass, Rf(L-MW a )2(1) Rf(Q-(Y) b -B)2(2) [wherein Rf represents the following general formula (3)] [ka] (In the formula, p, q, r, s, t, and u each independently represent an integer of 0 to 450, and p+q+r+s+t+u represents an integer of 20 to 450. The arrangement of the fluorooxyalkylene units enclosed in parentheses with p, q, r, s, t, and u may be block or random. v is independently an integer of 1 to 3 for each unit.) Each L is independently a single bond, an oxygen atom, a sulfur atom, or a divalent organic group; each M is independently a single bond, a nitrogen atom, a silicon atom, a carbon atom, a phosphorus atom, or a group containing any of these, or a divalent to octavalent organic group; each W is independently an alkenyl group or a monovalent organic group having an alkenyl group at the terminal; and each a is independently an integer of 1 to 7. Each Q is independently a single bond or a divalent organic group; each Y is independently a divalent organic group having an alkenyl group; each b is independently an integer of 1 to 10; and each B is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a halogen atom. (B) a fluorine-containing organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms per molecule: an amount such that the number of silicon-bonded hydrogen atoms (SiH groups) in component (B) is 0.5 to 5 moles per mole of alkenyl groups in component (A); (C) a hydrosilylation reaction catalyst: a catalytic amount, and (D) BET specific surface area is 50m 2 / g or more: 10 to 40 parts by mass A thermosetting perfluoropolyether rubber composition comprising: [2] In the formulas (1) and (2) of the component (A), Rf is represented by the following general formula (3'): [ka] (wherein p, q, r, s and v are the same as defined above, and p+q+r+s is an integer of 20 to 450, and each fluorooxyalkylene unit enclosed in parentheses with p, q, r and s may be in a block or random arrangement.) The thermosetting perfluoropolyether rubber composition according to [1], wherein p, q, r, s and v are the same as defined above, and p+q+r+s is an integer of 20 to 450, and each fluorooxyalkylene unit enclosed in parentheses with p, q, r and s may be in a block or random arrangement. [3] The thermosetting perfluoropolyether rubber composition according to [1] or [2], wherein the hydrophobic silica powder of component (D) has been surface-hydrophobized with at least one organosilicon compound selected from organochlorosilanes, organoalkoxysilanes, organodisilazanes, and cyclic organopolysilazanes. [4] The thermosetting perfluoropolyether rubber composition according to any one of [1] to [3], wherein the surface carbon content of the hydrophobic silica powder of component (D) is 0.1 to 20% by mass of the total amount of the hydrophobic silica powder. [5] The thermosetting perfluoropolyether rubber composition according to any one of [1] to [4], further comprising (E) a hydrosilylation reaction inhibitor. [6] The thermosetting perfluoropolyether rubber composition according to any one of [1] to [5], which is for injection molding. [Effects of the Invention]

[0010] The thermosetting perfluoropolyether rubber composition of the present invention can give a cured product (perfluoropolyether rubber cured product) that is excellent in heat resistance, chemical resistance, solvent resistance, low-temperature properties, and rubber physical properties (mechanical strength, elongation, etc.), and can also provide a thermosetting perfluoropolyether rubber composition that is excellent in liquid injection moldability and mold releasability. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below.

[0012] [Component (A)] Component (A) is a perfluoropolyether polymer having at least two alkenyl groups in the molecular chain, represented by the following general formula (1) or (2), and acts as the main component (base polymer) of the thermosetting perfluoropolyether rubber composition of the present invention. Rf(L-MW a )2(1) Rf(Q-(Y) b -B)2(2) [wherein Rf represents the following general formula (3)] [ka] (In the formula, p, q, r, s, t, and u each independently represent an integer of 0 to 450, and p+q+r+s+t+u represents an integer of 20 to 450. The arrangement of the fluorooxyalkylene units enclosed in parentheses with p, q, r, s, t, and u may be block or random. v is independently an integer of 1 to 3 for each unit.) Each L is independently a single bond, an oxygen atom, a sulfur atom, or a divalent organic group; each M is independently a single bond, a nitrogen atom, a silicon atom, a carbon atom, a phosphorus atom, or a group containing any of these, or a divalent to octavalent organic group; each W is independently an alkenyl group or a monovalent organic group having an alkenyl group at the terminal; and each a is independently an integer of 1 to 7. Each Q is independently a single bond or a divalent organic group; each Y is independently a divalent organic group having an alkenyl group; each b is independently an integer of 1 to 10; and each B is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a halogen atom.

[0013] In the formulas (1) and (2), Rf is a perfluoropolyoxyalkylene group represented by the following general formula (3). [ka] (In the formula, p, q, r, s, t, and u each independently represent an integer of 0 to 450, and p+q+r+s+t+u represents an integer of 20 to 450. The arrangement of the fluorooxyalkylene units enclosed in parentheses with p, q, r, s, t, and u may be block or random. v is independently an integer of 1 to 3 for each unit.)

[0014] In the above formula (3), p, q, r, s, t, and u are each independently an integer of 0 to 450, and preferably, p is an integer of 1 to 200, q is an integer of 1 to 200, r is an integer of 0 to 200, s is an integer of 0 to 200, t is an integer of 0 to 200, and u is an integer of 0 to 200, and p+q+r+s+t+u is an integer of 20 to 450, preferably an integer of 25 to 300. It is preferred that each fluorooxyalkylene unit enclosed in parentheses with s, t, or u be linear. That is, it is preferred that all fluorooxyalkylene units of the perfluoropolyoxyalkylene group of component (A) be linear, since this results in a composition with excellent injection moldability due to its low viscosity. Furthermore, the arrangement of each fluorooxyalkylene unit enclosed in parentheses p, q, r, s, t, and u may be block or random. Furthermore, v is independently an integer of 1 to 3 for each unit, and preferably 1 or 2, and the alkylene group may be linear or branched.

[0015] The perfluoropolyoxyalkylene group represented by formula (3) is more preferably a perfluoropolyoxyalkylene group represented by the following general formula (3'). [ka]

[0016] In the above formula (3'), p, q, r, s, and v are the same as in the above formula (3), and preferably, p is an integer of 1 to 200, q is an integer of 1 to 200, r is an integer of 0 to 200, and s is an integer of 0 to 200, and p+q+r+s is an integer of 20 to 450, preferably an integer of 25 to 300, and v is preferably 1 or 2 (i.e., in formula (3), t=u=0). Each fluorooxyalkylene unit enclosed in parentheses with p, q, r, and s may be block or random. Furthermore, the fluorooxyalkylene unit enclosed in parentheses with s is preferably linear.

[0017] Examples of Rf include those shown below. [ka] [ka] [ka] [ka] (In the formula, p1 is an integer of 1 to 200, q1 is an integer of 1 to 200, r1 is an integer of 1 to 200, and s1 is an integer of 1 to 200, and the sum of p1, q1, r1, and s1 in each formula is an integer in the range of 20 to 450. Each fluorooxyalkylene unit enclosed in parentheses may be in block or random arrangement.)

[0018] In the above formula (1), L is a single bond, an oxygen atom, a sulfur atom, or a divalent organic group, and is a linking group between the Rf group and the M group (or the W group). The divalent organic group is preferably an amide bond, an ether bond, a carbonyl bond, an ester bond, a diorganosilylene group such as a dimethylsilylene group, or —Si[OH][(CH) c1 Si(Me)3]- (c1 is an integer of 2 to 4, Me is a methyl group), and more preferably an unsubstituted or substituted divalent organic group having 1 to 12 carbon atoms which may contain the structure.

[0019] Examples of the unsubstituted or substituted divalent hydrocarbon group having 1 to 12 carbon atoms include alkylene groups such as methylene, ethylene, propylene (trimethylene, methylethylene), butylene (tetramethylene, methylpropylene), hexamethylene, and octamethylene, arylene groups such as phenylene, and combinations of two or more of these groups (e.g., alkylene-arylene groups). Furthermore, these groups may have some or all of the hydrogen atoms bonded to the carbon atoms substituted with halogen atoms such as fluorine and iodine. Among these, unsubstituted or substituted alkylene or phenylene groups having 1 to 4 carbon atoms are preferred.

[0020] Examples of the divalent organic group for L include groups represented by the following structures: In the following structures, it is preferred that the left bond is bonded to Rf and the right bond is bonded to M or W. [ka] [ka] [ka] [ka] [ka] (In the formula, c1 is independently an integer of 2 to 4, c2 is independently an integer of 1 to 4, c3 is an integer of 2 to 6, preferably an integer of 2 to 4, Me is a methyl group, and Et is an ethyl group.)

[0021] In the above formula (1), M is a single bond, or a nitrogen atom, a silicon atom, a carbon atom, a phosphorus atom, or a group containing any of these, or a divalent to octavalent (a+1) valent) organic group, which is a linking group between the L group (or the Rf group) and the W group. 1 a divalent group represented by 2C-, -R 3 A divalent group represented by 2Si-, -NR 4 A divalent group represented by -, a trivalent group represented by -N=, a trivalent group represented by -CO-N=, a trivalent group represented by -P=, a trivalent group represented by -PO=, -R 1 A trivalent group represented by C=, -R 3 Examples include a trivalent group represented by Si=, a trivalent isocyanuric group, a tetravalent group represented by -C≡, a tetravalent group represented by -OC≡, a tetravalent group represented by -Si≡, and a divalent to octavalent siloxane residue.

[0022] In the above, R 1 are each independently preferably a group having a repeating unit of an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, or an oxyalkylene group having 1 to 3 carbon atoms which may be interrupted by a diorganosiloxane structure having 2 to 51 silicon atoms, or R 2 3SiO-, and R 2 are each independently a hydrogen atom, an alkyl group preferably having 1 to 3 carbon atoms, an aryl group such as a phenyl group, or an alkoxy group having 1 to 3 carbon atoms. 3are each independently preferably an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 or 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a chloro group. 4 is an alkyl group having 1 to 3 carbon atoms, or an aryl group having 6 to 10 carbon atoms such as a phenyl group. When M is a siloxane residue, it preferably has a linear, branched, or cyclic organopolysiloxane structure having 2 to 51 silicon atoms, preferably 2 to 13 silicon atoms, more preferably 2 to 11 silicon atoms, and even more preferably 2 to 5 silicon atoms. The organopolysiloxane preferably has a C1 to C8, more preferably C1 to C4, unsubstituted or fluorine-substituted alkyl group such as methyl, ethyl, propyl, butyl, or C3F7-C3H6-, or a phenyl group. Furthermore, it is preferable to have a silalkylene structure in which two silicon atoms are bonded by an alkylene group, i.e., Si-(CH2) c3 In the above formula, c3 is an integer of 2 to 6, and preferably an integer of 2 to 4.

[0023] Examples of such M include those shown below. In the following structure, it is preferable that the carbon atom of the trivalent group represented by -CO-N= is bonded to L or Rf and the nitrogen atom is bonded to W. [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] (In the formula, c4 is an integer of 1 to 20, c5 is an integer of 1 to 50, and Me is a methyl group.)

[0024] In the above formula (1), W is an alkenyl group or a monovalent organic group having an alkenyl group at the terminal, and is preferably an alkenyl group or a group represented by the following formula: [ka] (In the formula, R 5 is an alkenyl group, and R 6 is an alkyl group having 1 to 4 carbon atoms or a phenyl group, c6 is an integer of 0 to 10, and d is an integer of 1 to 3.

[0025] Here, the alkenyl group of W and R in the above formula 5 The alkenyl group of W is preferably an alkenyl group having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, such as a vinyl group, allyl group, propenyl group, butenyl group, pentenyl group, or hexenyl group. Among these, the alkenyl group of W is preferably a vinyl group, butenyl group, or pentenyl group, and R 5 The alkenyl group is preferably a vinyl group or an allyl group. Also, R 6 is an alkyl group having 1 to 4 carbon atoms such as a methyl group or an ethyl group, or a phenyl group, and a methyl group is preferred. c6 is an integer of 0 to 10, preferably an integer of 0 to 3; d is an integer of 1 to 3, preferably 1;

[0026] Examples of such W include the following: [ka]

[0027] In formula (1), a is an integer of 1 to 7, preferably an integer of 1 to 3.

[0028] In formula (1), -MW aExamples of the structure represented by the formula include the following structures. [ka] [ka] [ka] [ka] [ka] (In the formula, R 5 , R 6 , c5, c6, and d are as defined above, c7 is an integer of 0 to 8, preferably an integer of 0 to 3, and Me is a methyl group.

[0029] In the above formula (2), Q is a single bond or a divalent organic group, and is a linking group between the Rf group and the Y group. The divalent organic group of Q is preferably an amide bond, an ether bond, an ester bond, a diorganosilylene group such as a dimethylsilylene group, or —Si[OH][(CH) c1 Si(Me)3]- (c1 is an integer of 2 to 4, Me is a methyl group), and more preferably an unsubstituted or substituted divalent organic group having 1 to 12 carbon atoms which may contain the structure.

[0030] Examples of the unsubstituted or substituted divalent hydrocarbon group having 1 to 12 carbon atoms include the same unsubstituted or substituted divalent hydrocarbon groups having 1 to 12 carbon atoms as exemplified for L above.

[0031] Examples of the divalent organic group for Q include groups represented by the following structure: In the following structure, it is preferred that the left bond is bonded to Rf and the right bond is bonded to Y. [ka] [ka] [ka] [ka] (In the formula, c1, c2, and c3 are the same as above, and Me is a methyl group.)

[0032] In the above formula (2), Y is a divalent organic group having an alkenyl group, and preferably has a structure represented by the following formula: [ka] (In the formula, R 5 , R 6 , c6, c7, and d are as defined above. e is an integer of 1 to 6, preferably 1 or 2, and M' is an unsubstituted or substituted trivalent to octavalent, preferably trivalent or tetravalent, hydrocarbon group, in which some or all of the carbon atoms in the hydrocarbon group may be replaced with silicon atoms, and some or all of the hydrogen atoms bonded to the carbon atoms may be replaced with halogen atoms such as fluorine atoms.

[0033] M' is preferably a group represented by the following structure. [ka] (In the above, M 1 is a single bond, an unsubstituted or substituted divalent hydrocarbon group having 1 to 6 carbon atoms, or a diorganosilylene group such as a dimethylsilylene group, and M 2 Ha-R 1 A trivalent group represented by C= or -R 3 Si= is a trivalent group represented by R 1 , R 3 is the same as above. R 7 is a hydrogen atom or a monovalent hydrocarbon group such as an alkyl group having 1 to 6 carbon atoms, e.g., a methyl group, an ethyl group, or a propyl group.

[0034] M1 Examples of the group include a single bond, a phenylene group, a dimethylsilylene group, and a tetrafluoroethylene group. 2 Examples of such a substance include the following: [ka] (In the formula, Me is a methyl group.)

[0035] Examples of such Y include the following groups: It is preferable that the left side is oriented to bond with Q or Rf, and the right side is oriented to bond with B. [ka] [ka] [ka] (In the formula, R 5 , R 6 , c6, c7, and d are the same as above, c6' is an integer of 2 to 10, preferably 2 or 3, and Me is a methyl group.

[0036] In the above formula (2), b is independently an integer of 1 to 10, preferably an integer of 1 to 4. Furthermore, B is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, or a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0037] Examples of the alkenyl group-containing perfluoropolyether polymer represented by the above formula (1) or (2) include the following structures: In the following formula, Me represents a methyl group. [ka] [ka] [ka]

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[0038]

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[0039]

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[0040]

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[0041] [ka] [ka] [ka] (In the formula, p1, q1, r1, s1, and the sum of p1, q1, r1, and s1 in each formula are the same as above. qs1 is an integer of 0 to 222, qs2 is an integer of 0 to 222, and the sum of qs1 and qs2 is an integer of 8 to 222. Each fluorooxyalkylene unit enclosed in parentheses may be block or random.)

[0042] Component (A) has at least two, preferably 2 to 6, alkenyl groups in the molecular chain, and the content of the alkenyl groups is preferably 0.005 to 0.3 mol / 100 g, and more preferably 0.007 to 0.2 mol / 100 g. In the present invention, the alkenyl group content is 1 The values ​​were measured by H-NMR.

[0043] The perfluoropolyether polymer of the component (A) may be used alone or in combination of two or more types.

[0044] [(B) Component] Component (B) is a fluorine-containing organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule, and is preferably a fluorine-containing organohydrogenpolysiloxane (fluorine-containing organohydrogenpolysiloxane) that has a perfluoroalkyl group or a perfluorooxyalkyl group, or a perfluoroalkylene group or a perfluorooxyalkylene group in one molecule, and further has two or more hydrogen atoms directly bonded to silicon atoms (SiH groups), and does not have epoxy groups or alkoxy groups directly bonded to silicon atoms in the molecule, and functions as a crosslinking agent for component (A).

[0045] The perfluoroalkyl group, perfluorooxyalkyl group, perfluoroalkylene group and perfluorooxyalkylene group are groups that are introduced from the viewpoints of compatibility with component (A), dispersibility, uniformity after curing, and the like.

[0046] Examples of the perfluoroalkyl group or perfluorooxyalkyl group include groups represented by the following general formula (4), (5) or (6). C f F 2f+1 - (4) (In formula (4), f is an integer of 1 to 10, preferably an integer of 3 to 7.) CF3O-(CF2CF2O) k (CF2O) l -CF2- (5) (In formula (5), k and l each represent an integer of 1 to 50, preferably an integer of 1 to 30, and the average value of k+l is 2 to 100, preferably 2 to 60. The repeating units may be bonded to each other randomly.) [ka] (In formula (6), g is an integer of 1 to 50, preferably an integer of 2 to 30.)

[0047] Furthermore, the perfluoroalkylene group or perfluorooxyalkylene group includes groups represented by the following general formulas (7) to (9). -C h F 2h - (7) (In formula (7), h is an integer of 1 to 20, preferably an integer of 2 to 10.) [ka] (In formula (8), i and j each represent an integer of 1 or more, preferably an integer of 1 to 100, and the average value of i+j is 2 to 200, preferably 2 to 100.) -CF2O-(CF2CF2O) k (CF2O) l -CF2- (9) (In formula (9), k and l each represent an integer of 1 to 50, preferably an integer of 1 to 30, and the average value of k+l is 2 to 100, preferably 2 to 60. The repeating units may be bonded to each other randomly.)

[0048] Furthermore, these perfluoroalkyl groups, perfluorooxyalkyl groups, perfluoroalkylene groups, or perfluorooxyalkylene groups are preferably linked to the silicon atoms constituting the polysiloxane via a divalent linking group. The divalent linking group is preferably an unsubstituted or substituted divalent hydrocarbon group having 2 to 13 carbon atoms, particularly 2 to 8 carbon atoms, which may contain an oxygen atom, a nitrogen atom, or a silicon atom. Specific examples include alkylene groups, arylene groups, and combinations thereof, as well as those in which one or more structures selected from the group consisting of an ether-bonded oxygen atom, an amide bond, a carbonyl bond, an ester bond, and a diorganosilylene group such as a dimethylsilylene group are interposed between these groups. For example, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2OCH2-, -CH2CH2CH2-NH-CO-, -CH2CH2CH2-N(Ph)-CO-, -CH2CH2CH2-N(Me)-CO-, -CH2CH2CH2-N(Et)-CO-, -CH2CH2CH2-N(iPr)-CO-, -CH2CH2CH2-O-CO-, -CH2CH2-Si(Me)2-Ph'-N(Me)-CO-, -CH2CH2CH2-Si(Me)2-Ph'-N(Me)-CO- (wherein Me is a methyl group, Et is an ethyl group, iPr is an isopropyl group, Ph is a phenyl group, and Ph' is a phenylene group.) In the above exemplary structures, it is preferred that the left bond is bonded to a silicon atom constituting the polysiloxane, and the right bond is bonded to a perfluoroalkyl group, a perfluorooxyalkyl group, a perfluoroalkylene group, or a perfluorooxyalkylene group.

[0049] In the fluorine-containing organohydrogenpolysiloxane of component (B), the monovalent or divalent fluorine-containing organic group and the monovalent substituent bonded to the silicon atom other than the hydrogen atom directly bonded to the silicon atom are unsubstituted or substituted alkyl groups having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, or aryl groups having 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms. Examples include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, octyl, and decyl; aryl groups such as phenyl, tolyl, and naphthyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as chlorine atoms, cyano groups, or the like, such as chloromethyl, chloropropyl, and cyanoethyl. Among these, methyl groups are preferred. The fluorine-containing organopolysiloxane does not contain epoxy or alkoxy groups.

[0050] The structure of the fluorine-containing organohydrogenpolysiloxane of component (B) may be cyclic, linear, three-dimensional network, or a combination thereof. The number of silicon atoms in this fluorine-containing organohydrogenpolysiloxane is not particularly limited, but is usually about 2 to 60, preferably 3 to 30, and more preferably 4 to 30. Furthermore, component (B) has two or more, preferably three or more, SiH groups per molecule, and the content of the SiH groups is preferably 0.0001 to 0.02 mol / g, and more preferably 0.0002 to 0.01 mol / g. In the present invention, the content of the SiH groups is 1 The values ​​were measured by H-NMR.

[0051] Examples of the component (B) include those represented by the following general formulas (10) to (16). [ka] In formula (10), each A is independently a perfluoroalkyl group or perfluorooxyalkyl group bonded to a silicon atom constituting the siloxane via a divalent hydrocarbon group which may have an oxygen atom, a nitrogen atom, or a silicon atom. Examples of the perfluoroalkyl group or perfluorooxyalkyl group include groups represented by the general formulas (4) to (6) above. R 8 are each independently the above-mentioned unsubstituted or substituted alkyl group having 1 to 20 carbon atoms, preferably 1 to 12, or an aryl group having 6 to 20 carbon atoms, preferably 6 to 12. α is an integer of 2 to 6, preferably an integer of 3 to 6, β is an integer of 1 to 4, preferably an integer of 1 to 3, and α+β is an integer of 4 to 10, preferably an integer of 4 to 9. However, -(Si(H)(R 8 )O)- and -(Si(A)(R 8 The bonding order of )O)- is not limited.

[0052] [ka] (In formula (11), A's are each independently the same as A's above, and R 8 are independent of each other, and the above R 8 In addition, γ is an integer of 2 to 50, preferably an integer of 3 to 30.

[0053] [ka] (In formula (12), A's are each independently the same as A's above, and R 8 are independent of each other, and the above R 8 where γ is an integer of 2 to 50, preferably an integer of 3 to 30, δ is an integer of 1 to 40, preferably an integer of 1 to 20, and γ+δ is an integer of 4 to 60, preferably an integer of 4 to 50. However, -(Si(H)(R 8 )O)- and -(Si(A)(R 8 The bonding order of )O)- is not limited.

[0054] [ka] (In formula (13), A's are each independently the same as A's above, and R 8 are independent of each other, and the above R 8 is the same as above. γ is an integer of 2 to 50, preferably an integer of 3 to 30, ε is an integer of 1 to 40, preferably an integer of 1 to 20, and γ+ε is an integer of 4 to 60, preferably an integer of 4 to 50. However, -(Si(H)(R 8 )O)- and -(Si(R 8 The order of bonding of )2O)- is not limited.

[0055] [ka] (In formula (14), A's are each independently the same as A's above, and R 8 are independent of each other, and the above R 8 where γ is an integer of 2 to 50, preferably an integer of 3 to 30, δ is an integer of 1 to 40, preferably an integer of 1 to 20, ε is an integer of 1 to 40, preferably an integer of 1 to 20, and γ+δ+ε is an integer of 5 to 60, preferably an integer of 5 to 50. However, -(Si(H)(R 8 )O)-, -(Si(A)(R 8 )O)- and -(Si(R 8 The order of bonding of )2O)- is not limited.

[0056] [ka] In formula (15), D is an oxygen atom, an alkylene group, or a perfluoroalkylene group or perfluorooxyalkylene group bonded to adjacent silicon atoms via a divalent hydrocarbon group which may have an oxygen atom or a nitrogen atom. Examples of the perfluoroalkylene group or perfluorooxyalkylene group include any of the groups represented by the general formulae (7) to (9). Each A is independently the same as the above A, and R 8 are independent of each other, and the above R 8is the same as above. Furthermore, ζ is an integer of 0 to 3, η is an integer of 0 to 3, and ζ + η is an integer of 2 to 6, preferably an integer of 3 to 5. However, in formula (15), there is at least one group selected from a perfluoroalkyl group, a perfluorooxyalkyl group, a perfluoroalkylene group, and a perfluorooxyalkylene group.

[0057] [ka] (In formula (16), A is the same as A above, and R 8 are independent of each other, and the above R 8 is the same as

[0058] Specific examples of component (B) include the following compounds. These compounds may be used alone or in combination of two or more. In the following formula, Me represents a methyl group and Ph represents a phenyl group. The arrangement of each siloxane unit is random.

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] [ka]

[0063] [ka]

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] [ka] (In the formula, f' is an integer of 1 to 10, g' is an integer of 1 to 50, and h' is an integer of 1 to 20. i' and j' are each an integer of 1 to 100, and i'+j' is an integer of 2 to 200. k' and l' are each an integer of 1 to 50, and k'+l' is an integer of 2 to 100. Furthermore, each repeating unit enclosed in parentheses with k' and l' may be bonded randomly.)

[0072] The amount of component (B) blended is an amount (molar ratio) such that the number of silicon-bonded hydrogen atoms (SiH groups) in component (B) is 0.5 to 5 moles per mole of alkenyl groups in component (A), and preferably 0.6 to 3 moles per mole. If the number of SiH groups is less than 0.5 moles, the degree of crosslinking will be insufficient, while if it is more than 5 moles, the storage stability will be impaired and the heat resistance of the cured product obtained after curing will be reduced. When a polyfluoromonoalkenyl compound (plasticizer, viscosity modifier, and / or flexibility-imparting agent) or an adhesion improver described below is blended as an optional component, the amount is preferably such that the silicon-bonded hydrogen atoms (SiH groups) contained in the composition (particularly the total of silicon-bonded hydrogen atoms (SiH groups) contained in the above-mentioned component (B) and the adhesion improver) are 0.5 to 5 moles per mole of alkenyl groups contained in the composition of the present invention (particularly the total of alkenyl groups in the above-mentioned component (A) and the below-mentioned polyfluoromonoalkenyl compound (plasticizer, viscosity modifier, and / or flexibility-imparting agent)).

[0073] The fluorine-containing organohydrogenpolysiloxane of component (B) may use either a single type alone or a combination of two or more types.

[0074] [(C) component] The hydrosilylation catalyst, component (C), promotes the addition reaction between components (A) and (B). This hydrosilylation catalyst is generally a noble metal (particularly a platinum group metal) or a compound thereof, and is expensive, so platinum or a platinum compound is often used, which is relatively easy to obtain.

[0075] Examples of platinum compounds include chloroplatinic acid or a complex of chloroplatinic acid with an olefin such as ethylene, a complex of chloroplatinic acid with an alcohol or vinylsiloxane, and metallic platinum supported on silica, alumina, carbon, or the like. Other than platinum or platinum compounds, rhodium, ruthenium, iridium, and palladium compounds are also known as hydrosilylation catalysts, such as RhCl(PPh3)3, RhCl(CO)(PPh3)2, and Ru3(CO).12 Examples include IrCl(CO)(PPh3)2, Pd(PPh3)4, etc. In the above formula, Ph is a phenyl group.

[0076] When using these catalysts, if they are solid catalysts, they can be used in a solid state. However, in order to obtain a more uniform cured product, it is preferable to use chloroplatinic acid or a complex in the form of a solution dissolved in an appropriate solvent such as toluene or ethanol in the composition.

[0077] The component (C) may be used alone or in combination of two or more types. The amount of these catalysts used is not particularly limited, and the desired curing rate can be obtained with any amount of catalyst. From an economical standpoint or to obtain a good cured product, the amount is usually 0.1 to 2,000 ppm, preferably 0.1 to 500 ppm, and particularly preferably 0.5 to 200 ppm (calculated as the mass of platinum group metal atoms) relative to the mass of component (A), but this amount can be increased or decreased as appropriate depending on the desired curing rate.

[0078] The conditions for the above addition reaction (hydrosilylation reaction) can be selected appropriately, and the reaction may be carried out at room temperature (25°C ± 10°C, the same applies hereinafter), but can be carried out by heating to 50 to 200°C to speed up the reaction.

[0079] [(D) component] The hydrophobic silica powder of component (D) acts as a reinforcing filler and improves the rubber properties such as mechanical strength (rubber hardness, tensile strength, tear strength, elongation at break) of the cured product (perfluoropolyether rubber cured product), which is a rubber-like elastic body (elastomer) obtained by curing the thermosetting perfluoropolyether rubber composition of the present invention, and at the same time, it also acts to exhibit good injection moldability and mold releasability when the thermosetting perfluoropolyether rubber composition of the present invention is cured by injection molding.

[0080] The hydrophobic silica powder of component (D) may be silica powder such as fumed silica (fumed silica or dry silica), precipitated silica (wet silica), spherical silica (fused silica), sol-gel silica, or silica aerogel, and the surface of such silica powder may be treated with a silane compound having a hydrolyzable group, such as an organochlorosilane, such as dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, vinyldimethylchlorosilane, divinylmethylchlorosilane, or trivinylchlorosilane; an organoalkoxysilane, such as dimethyldimethoxysilane, trimethylmethoxysilane, methyltrimethoxysilane, vinyldimethylmethoxysilane, divinylmethylmethoxysilane, trivinylmethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, methyltriethoxysilane, vinyldimethylethoxysilane, divinylmethylethoxysilane, or trivinylethoxysilane; hexamethyldisilazane, 1, At least one selected from organodisilazanes such as 3-divinyl-1,1,3,3-tetramethyldisilazane, 1,3-diphenyl-1,1,3,3-tetramethyldisilazane, heptamethyldisilazane, and 1,3-bis(chloromethyl)-1,1,3,3-tetramethyldisilazane; and cyclic organopolysilazanes such as 1,3,5-trimethyl-1,3,5-trivinylcyclotrisilazane and 1,1,3,3,5,5-hexamethylcyclotrisilazane. Examples of suitable hydrophobic silica powders include hydrophobic silica powders (surface-hydrophobized silica powders) obtained by hydrophobizing the surface of the surface-hydrophobized silica powder with at least one organosilicon compound, hydrophobic silica powders obtained by further treating the surface of the surface-hydrophobized silica powder with a fluorine-containing organosilane or fluorine-containing organosiloxane having a perfluoroalkyl or perfluorooxyalkyl group in order to improve dispersibility, and quartz powders (crystalline silica), fused quartz powders, diatomaceous earth, etc., which have been surface-hydrophobized in the same manner as above. Among these, fumed silica is particularly preferred from the viewpoints of improving mechanical strength, liquid injection moldability (LIMS moldability) and mold releasability, and improving the dispersion stability of each composition.

[0081] In this hydrophobic treatment, the silica powder whose surface is treated with a surface treatment agent is preferably one that has been treated directly in a powder state in advance, and the treatment method can usually be a well-known technique, for example, by placing the untreated silica powder and one or more treatment agents in a mechanical kneading device sealed at atmospheric pressure or in a fluidized bed, mixing them at room temperature or by heat treatment in the presence of an inert gas as needed, optionally using a catalyst and water to promote hydrolysis, and then drying to prepare the resulting mixture. The amount of surface treatment agent to be added should be equal to or greater than the amount calculated from the area that the surface treatment agent can cover on the surface of the silica powder.

[0082] The degree of hydrophobic treatment of the hydrophobic silica powder of component (D) is preferably in the range of 0.1 to 20 mass% and more preferably 0.5 to 10 mass% in terms of the amount of surface carbon (carbon content: mass%) in the entire hydrophobic silica powder after treatment. If the surface carbon content is less than 0.1 mass%, uniform kneading with component (A) may be difficult, while if the surface carbon content exceeds 20 mass%, the cured product of the composition may not have sufficient mechanical strength. In the present invention, the surface carbon content is a value measured by a known elemental analysis method.

[0083] In addition, when the hydrophobic silica powder of component (D) has alkenyl groups in the surface carbon after treatment, the amount of the surface alkenyl groups is 1.0 × 10 -3 ~2.0×10 -2 mol / 100g, and preferably in the range of 1.5 x 10 -3 ~1.5×10 -2 It is more preferable that the amount of surface alkenyl groups is in the range of 2.0×10 -2 If the amount exceeds mol / 100 g, it may be difficult to uniformly knead the component (A). In the present invention, the amount of surface alkenyl groups is a value measured by FT-IR.

[0084] It should be noted that unless the above-mentioned various silica powders are hydrophobic silica powders whose surfaces have been hydrophobized (i.e., untreated hydrophilic silica powders whose surfaces have not been hydrophobized), they will not be able to sufficiently improve the rubber properties of the cured product, nor will they be able to exhibit excellent liquid injection moldability (LIMS moldability) or mold releasability.

[0085] The specific surface area of ​​the hydrophobic silica powder of component (D) measured by the BET method is 50m2 in order to improve the mechanical strength of the cured product (rubber hardness, tensile strength, tear strength, elongation at break) and other rubber properties. 2 / g or more, but 100m 2 / g or more is preferable, but when the silica powder is mixed into the composition, the viscosity increases significantly, which may make the mixing difficult. 2 / g or less is preferable.

[0086] Furthermore, the hydrophobic silica powder of component (D) preferably has a bulk density of 30 to 180 g / L, particularly 40 to 150 g / L. If the bulk density of the hydrophobic silica powder is less than 30 g / L, the viscosity of the composition increases, making it difficult to blend, while if it exceeds 180 g / L, it may not provide a sufficient reinforcing effect. In the present invention, the bulk density is a value measured by a tapping method or the like.

[0087] The hydrophobic silica powder of component (D) may be used alone or in combination of two or more types.

[0088] The amount of hydrophobic silica powder (Component (D)) blended per 100 parts by mass of Component (A) is 10 to 40 parts by mass, and more preferably 15 to 30 parts by mass. If it is less than 10 parts by mass, no improvement in mechanical strength is observed, and if it is more than 40 parts by mass, the viscosity increases significantly, making blending difficult.

[0089] [(E) component] Component (E) is a hydrosilylation reaction inhibitor, an optional component that can be incorporated as needed. Examples of hydrosilylation addition reaction inhibitors include acetylenic alcohols such as 1-ethynyl-1-cyclohexanol (also known as 1-ethynyl-1-hydroxycyclohexane), 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentyn-3-ol, and phenylbutynol; reaction products of chlorosilanes having perfluoroalkyl groups represented by the general formula (4) above or perfluorooxyalkyl groups represented by the general formulas (5) and (6) above with acetylenic alcohols; 3-methyl-3-penten-1-yne, 3,5-dimethyl-3-hexen-1-yne, triallyl isocyanurate; polyvinyl siloxanes; and organophosphorus compounds. The addition of these inhibitors can maintain appropriate curing reactivity and storage stability. Component (E) can be used alone or in combination.

[0090] The amount of component (E) blended is arbitrary as long as it does not impair the object of the present invention, but when component (E) is blended, the blending amount is preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 2 parts by mass, per 100 parts by mass of component (A). If the blending amount is too small, workability may be poor (sufficient shelf life and pot life may not be obtained), and if the blending amount is too large, the curability of the composition may be reduced.

[0091] [Other ingredients] To enhance its practical utility, the thermosetting perfluoropolyether rubber composition of the present invention may optionally contain, in addition to the above components (A) to (E), fillers other than component (D), adhesion aids (adhesion improvers) capable of imparting self-adhesion to the cured product of the composition, plasticizers, viscosity modifiers, flexibility-imparting agents, inorganic pigments such as titanium oxide, iron oxide, carbon black, and cobalt aluminate, heat resistance improvers such as titanium oxide, iron oxide, carbon black, cerium oxide, cerium hydroxide, zinc carbonate, magnesium carbonate, and manganese carbonate, thermal conductivity imparting agents such as alumina, boron nitride, silicon carbide, and metal powder, and conductivity imparting agents such as carbon black, silver powder, and conductive zinc oxide. The amounts of these additives may be arbitrarily determined as long as they do not impair the object of the present invention.

[0092] [Adhesion aid (adhesion improver)] The adhesion promoter is an organopolysiloxane having, in one molecule, a hydrogen atom directly bonded to a silicon atom, a perfluoroalkyl group or a perfluorooxyalkyl group, and an epoxy group or a trialkoxysilyl group, or both, bonded to a silicon atom via a divalent hydrocarbon group which may contain an oxygen atom, and functions as an adhesion promoter that imparts self-adhesion to the cured product obtained by curing the composition of the present invention.

[0093] The perfluoroalkyl group or perfluorooxyalkyl group is a group that is introduced from the viewpoints of compatibility with the component (A), dispersibility, uniformity after curing, and the like. Examples of the perfluoroalkyl group or perfluorooxyalkyl group include groups represented by the above general formulas (4) to (6).

[0094] The perfluoroalkyl group or perfluorooxyalkyl group is preferably linked to a silicon atom constituting the polysiloxane via a divalent hydrocarbon group (linking group) which may contain at least one atom selected from silicon atoms, oxygen atoms, and nitrogen atoms. The divalent hydrocarbon group may be an alkylene group, an arylene group, or a combination thereof, or may be one in which one or more structures selected from the group consisting of an ether-bonded oxygen atom, an amide bond, a carbonyl bond, an ester bond, and a diorganosilylene group such as a dimethylsilylene group are interposed between these groups, such as, for example: -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2OCH2-, -CH2CH2CH2-NH-CO-, -CH2CH2CH2-N(Ph)-CO-, -CH2CH2CH2-N(Me)-CO-, -CH2CH2CH2-N(Et)-CO-, -CH2CH2CH2-N(iPr)-CO-, -CH2CH2CH2-O-CO-, -CH2CH2CH2-Si(Me)2-O-Si(Me)2-CH2CH2CH2-, -CH2CH2-Si(Me)2-O-Si(Me)2-CH2CH2CH2OCH2-, -CH2CH2-Si(Me)2-Ph'-N(Me)-CO-, -CH2CH2-Si(Me)2-O-Si(Me)2-CH2CH2-Si(Me)2-Ph'-N(Me)-CO-, -CH2-[CH2CH2-Si(Me)2]3-Ph'-NH-CO-, -[CH2CH2-Si(Me)2]3-Ph'-N(Me)-CO- (wherein Me is a methyl group, Et is an ethyl group, iPr is an isopropyl group, Ph is a phenyl group, and Ph' is a phenylene group.) In the above exemplary structures, it is preferred that the left bond is bonded to a silicon atom constituting the polysiloxane, and the right bond is bonded to a perfluoroalkyl group or a perfluorooxyalkyl group.

[0095] The organopolysiloxane is preferably a cyclic organopolysiloxane represented by the following general formula (17). [ka] (In the formula, θ is an integer of 1 to 6, preferably an integer of 1 to 5, ι is an integer of 1 to 4, preferably an integer of 1 to 3, κ is an integer of 1 to 4, preferably an integer of 1 to 3, and θ + ι + κ is an integer of 4 to 10, preferably an integer of 4 to 8. In addition, R 9 are each independently an unsubstituted or substituted monovalent hydrocarbon group, each T is independently a perfluoroalkyl group or a perfluorooxyalkyl group bonded to a silicon atom via a divalent hydrocarbon group which may contain at least one atom selected from a silicon atom, an oxygen atom, and a nitrogen atom, and each G is independently an epoxy group or a trialkoxysilyl group bonded to a silicon atom via a divalent hydrocarbon group which may contain an oxygen atom, provided that -(SiO)(H)R 9 -, -(SiO)(T)R 9 - and -(SiO)(G)R 9 The order of bonding is not limited.)

[0096] In the above general formula (17), R 9 are each independently an unsubstituted or substituted monovalent hydrocarbon group, and 8 The same groups as those listed above can be mentioned, and a methyl group and an ethyl group are preferred.

[0097] Each T is independently a perfluoroalkyl group or a perfluorooxyalkyl group bonded to a silicon atom via a divalent hydrocarbon group which may contain at least one selected from a silicon atom, an oxygen atom, and a nitrogen atom, and examples of this perfluoroalkyl group or perfluorooxyalkyl group include the groups represented by the above-mentioned general formulas (4) to (6). Examples of the divalent hydrocarbon group which may contain at least one selected from a silicon atom, an oxygen atom, and a nitrogen atom include the above-mentioned alkylene groups, arylene groups, and combinations thereof, as well as those in which one or more structures selected from the group consisting of an ether-bonded oxygen atom, an amide bond, a carbonyl bond, an ester bond, and a diorganosilylene group such as a dimethylsilylene group are interposed between these groups.

[0098] Furthermore, each G is independently an epoxy group or a trialkoxysilyl group bonded to a silicon atom via a divalent hydrocarbon group which may contain an oxygen atom. Examples of such epoxy groups include those represented by the following general formula (18) and alicyclic epoxy groups represented by the later-described general formula (19). [ka]

[0099] In the above general formula (18), R 10 is a divalent hydrocarbon group having preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, which may contain an oxygen atom, particularly an ether bond oxygen atom, a carbonyl bond or an ester bond, and specifically includes alkylene groups such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, and an octylene group, cycloalkylene groups such as a cyclohexylene group, oxyalkylene groups such as an oxyethylene group, an oxypropylene group, and an oxybutylene group, and the structure shown below: -CH2CH2CH2OCH2-, -CH2CH2CH2OCO- Examples include:

[0100] Specific examples of such epoxy groups include those shown below. [ka]

[0101] The alicyclic epoxy group may be a group represented by the following formula (19): [ka] (In the formula, R 10 is the same as above.) An epoxycyclohexyl group represented by the following formula is preferred.

[0102] Specific examples of such epoxycyclohexyl groups include those shown below. [ka]

[0103] On the other hand, examples of the trialkoxysilyl group include those represented by the following general formula (20). -R 11 -Si(OR 12 )3(20)

[0104] In the above general formula (20), R 11 is preferably a divalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and specific examples thereof include alkylene groups such as methylene, ethylene, propylene, butylene, hexylene, cyclohexylene, and octylene. 12 is preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and specific examples thereof include alkyl groups such as a methyl group, an ethyl group, and an n-propyl group.

[0105] Specific examples of such trialkoxysilyl groups include those shown below. -(CH2)2-Si(OMe)3 -(CH2)3-Si(OMe)3 -(CH2)2-Si(OEt)3 -(CH2)3-Si(OEt)3 (where Me is a methyl group and Et is an ethyl group.)

[0106] Examples of such adhesion promoters include the following compounds: (Me represents a methyl group, and Et represents an ethyl group.) The arrangement of the siloxane units is random. [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] [ka]

[0112] [ka]

[0113] [ka] (In the formula, f″ is an integer of 1 to 10, and g″ is an integer of 1 to 50.)

[0114] This adhesive aid may be used alone or in combination of two or more. When an adhesive aid is used, the amount used is preferably in the range of 0.01 to 20 parts by mass, more preferably 0.01 to 10 parts by mass, and even more preferably 0.01 to 8 parts by mass, per 100 parts by mass of component (A). If the amount is less than 0.01 part by mass, sufficient adhesion may not be obtained, while if it exceeds 20 parts by mass, the physical strength of the cured product obtained by curing the composition of the present invention may decrease.

[0115] As the plasticizer, viscosity modifier, and flexibility-imparting agent, a non-reactive (non-functional) linear polyfluoro compound represented by the following general formulas (21) and (22), which does not have functional groups (alkenyl groups and hydrosilyl groups) involved in the hydrosilylation addition reaction in the molecule, and / or a polyfluoromonoalkenyl compound represented by the following general formula (23) can be used.

[0116] F-(CF2CF2CF2O) w -J (21) (In equation (21), J is C o F 2o+1 - (o is an integer of 1 to 3), and w is an integer of 1 to 500, preferably an integer of 2 to 300.

[0117] J-{(OCF(CF3)CF2) x -(OCF2CF2) y -(OCF2) z}-OJ (twenty two) (In formula (22), J is the same as above, and x and y each represent an integer of 0 to 300, preferably an integer of 0 to 150, except when both x and y are 0. In addition, z represents an integer of 1 to 300, preferably an integer of 1 to 150. The repeating units may be bonded to each other randomly.)

[0118] F-[CF(CF3)CF2O] m -C n F 2n -U-CH=CH2(23) In formula (23), m is an integer of 1 to 200, preferably an integer of 1 to 150; n is an integer of 1 to 3; U is a single bond, or —CH—, —OCH—, —CHOCH—, or —CO—NR 13 -V- Ri,ko Each of these groups has a C n F 2n The right end of the group is bonded to a C—H group. In addition , R 13 is a hydrogen atom, a methyl group, a phenyl group, or an allyl group, and V is -CH2-, a group represented by the following structural formula (24) or a group represented by the following structural formula (25). [ka] (o-th, m-th or p-th Contains a dimethylsilylene group It is a dimethylphenylsilylene group, with the left end bonded to a nitrogen atom and the right end bonded to a carbon atom. Me represents a methyl group. [ka] (The left end is bonded to a nitrogen atom, and the right end is bonded to a carbon atom. Me represents a methyl group. )]

[0119] Specific examples of the linear polyfluoro compound represented by the above general formula (21) or (22) include the following. F-(CF2CF2CF2O) w’ -CF2CF3 (W' is an integer between 1 and 200.) CF3-{(OCF(CF3)CF2) x’ -(OCF2) z’}-O-CF3 (x' is an integer of 1 to 200, and z' is an integer of 1 to 200. The repeating units may be bonded to each other randomly.) CF3-{(OCF2CF2) y’ -(OCF2) z’}-O-CF3 (y' is an integer of 1 to 200, and z' is an integer of 1 to 200. The repeating units may be bonded to each other randomly.)

[0120] The linear polyfluoro compounds represented by the above general formula (21) or (22) may be used singly or in combination of two or more kinds.

[0121] Specific examples of the polyfluoromonoalkenyl compound represented by the above general formula (23) include the following. [ka] (Here, m' is an integer of 1 to 200, and Me represents a methyl group.)

[0122] The polyfluoromonoalkenyl compounds represented by the general formula (23) may be used singly or in combination of two or more kinds.

[0123] The amounts of these additives to be added may be arbitrary within the range that does not impair the object of the present invention.

[0124] The thermosetting perfluoropolyether rubber composition of the present invention can be prepared by uniformly mixing the predetermined amounts of the above-mentioned components (A) to (D), optionally component (E), and other components by a known method, but is particularly preferably prepared by the following method. First, the predetermined amounts of components (A) and (D) are kneaded using equipment such as a planetary mixer or kneader. When mixing these components, room temperature is acceptable, but heating may be performed within a temperature range that does not decompose the polymer for purposes such as stabilizing shear heat, preferably at 100 to 300°C for approximately 10 minutes to 8 hours. The kneaded mixture is then cooled to room temperature and further processed (kneaded) at room temperature (25°C ± 10°C) using equipment such as a three-roll mill. Next, a predetermined amount of component (C) is added to the obtained kneaded mixture using equipment such as a planetary mixer, and the mixture is kneaded at room temperature for 1 to 120 minutes. If necessary, predetermined amounts of component (E) and other optional components are added, and the mixture is kneaded at room temperature for 1 to 120 minutes. Thereafter, a predetermined amount of component (B) is added, and the mixture is kneaded at room temperature for 1 to 120 minutes, thereby preparing a thermosetting perfluoropolyether rubber composition.

[0125] Conventional methods can be used to mold the thermosetting perfluoropolyether rubber composition of the present invention, but the most suitable means for the purpose can be selected from injection molding, transfer molding, casting, compression molding, extrusion molding, coating, etc. In particular, the thermosetting perfluoropolyether rubber composition of the present invention is preferably molded by injection molding, since it is in a low-viscosity liquid state before curing and has excellent injection moldability and mold releasability. In this case, the thermosetting perfluoropolyether rubber composition can be cured by heating for 0.1 to 30 minutes, particularly 1 to 30 minutes, particularly 5 to 20 minutes at a temperature of 100 to 200°C, particularly 110 to 190°C, and especially 120 to 170°C. If necessary, a secondary vulcanization (postcure) may be carried out at 100 to 230°C for about 1 to 24 hours.

[0126] The cured product of the thermosetting perfluoropolyether rubber composition of the present invention thus obtained is excellent in heat resistance, chemical resistance, solvent resistance, low-temperature characteristics, and rubber physical properties (mechanical strength, elongation, etc.), and is therefore suitable for use in a wide range of applications, including diaphragms such as fuel regulator diaphragms, pulsation damper diaphragms, oil pressure switch diaphragms, and EGR diaphragms, valves such as canister valves and power control valves, O-rings such as quick connector O-rings and injector O-rings, and sealing materials such as oil seals and cylinder head gaskets, as well as rubber parts for chemical plants, specifically pump diaphragms, valves, O-rings, hoses, etc. The rubber can be suitably used for applications such as seals such as valves, valves, O-rings, packings, oil seals, gaskets, and other seals for equipment that comes into contact with chemicals, valves that require low friction and abrasion resistance, rubber parts for analytical and physical / chemical equipment such as pump diaphragms, valves, and sealing parts (O-rings, packings, etc.), rubber parts for medical equipment such as pumps, valves, and joints, as well as tent membrane materials, sealants, molded parts, extruded parts, coating materials, copier roll materials, moisture-proof coating materials for electrical equipment, potting materials for sensors, sealing materials for fuel cells, and laminated rubber cloth. [Example]

[0127] below ,fruit The present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples. In the following exemplary formulas, Me is a methyl group. In the following examples, the alkenyl group content and the SiH group content are 1 Measurement was performed by H-NMR. Room temperature indicates 25°C.

[0128] Components (A) to (E) used in the following examples and comparative examples are shown below.

[0129] Component (A) (A-1): Perfluoropolyether polymer represented by the following formula (p1+q1=120, p1:q1=48:52, alkenyl group content 0.017 mol / 100 g) [ka]

[0130] (A-2): Perfluoropolyether polymer represented by the following formula (p1+q1=90, p1:q1=48:52, alkenyl group content 0.023 mol / 100 g) [ka]

[0131] (A-3): Perfluoropolyether polymer represented by the following formula (p1+q1=35, p1:q1=48:52, alkenyl group content 0.053 mol / 100 g) [ka]

[0132] (A-4): Perfluoropolyether polymer represented by the following formula (r1=120, alkenyl group content 0.0098 mol / 100 g) [ka]

[0133] (A-5): Perfluoropolyether polymer represented by the following formula (qs1+qs2=58, alkenyl group content 0.0097 mol / 100 g) [ka]

[0134] (A-6): Perfluoropolyether polymer represented by the following formula (p1+q1=120, p1:q1=48:52, alkenyl group content 0.018 mol / 100 g) [ka]

[0135] (A-7): Perfluoropolyether polymer represented by the following formula (p1+q1=120, p1:q1=48:52, alkenyl group content 0.017 mol / 100 g) [ka]

[0136] (A-8): Perfluoropolyether polymer represented by the following formula (p1+q1=120, p1:q1=48:52, alkenyl group content 0.036 mol / 100 g) [ka]

[0137] (A-9): Perfluoropolyether polymer represented by the following formula (p1+q1=120, p1:q1=48:52, alkenyl group content 0.034 mol / 100 g) [ka]

[0138] (A-10): Alkenyl group-containing polymer represented by the following formula (a1+b1=120, a1:b1=1:1, alkenyl group content 0.0092 mol / 100 g) [ka]

[0139] (A-11): Alkenyl group-containing polymer represented by the following formula (a1+b1=100, a1:b1=1:1, alkenyl group content 0.012 mol / 100 g) [ka]

[0140] (A-12): Alkenyl group-containing polymer represented by the following formula (a1+b1=35, a1:b1=1:1, alkenyl group content 0.030 mol / 100 g) [ka]

[0141] (B) Component (B-1): Compound represented by the following formula (SiH group content: 0.0050 mol / g) [ka]

[0142] (C) Component (C-1): Toluene solution of platinum-divinyltetramethyldisiloxane complex (platinum concentration 0.5% by mass)

[0143] (D) Component (D-1): A-130 (a hydrophilic fumed silica manufactured by Nippon Aerosil Co., Ltd.) is hydrophobically treated with a mixture of hexamethyldisilazane and 1,3-divinyl-1,1,3,3-tetramethyldisilazane. (BET specific surface area: approximately 200 m 2 / g, surface carbon content (carbon content): approximately 5.0 mass%, surface vinyl group content: 3.00 × 10 -3 mol / 100g, bulk density: approx. 50g / L) (D-2): R-972 (manufactured by Nippon Aerosil Co., Ltd.) Hydrophobic fumed silica whose surface has been hydrophobized with dimethyldichlorosilane. BET specific surface area: approximately 110 m 2 / g, surface carbon content (carbon content): 0.6 to 1.2 mass%, bulk density: approximately 50 g / L) (D-3): R-974 (manufactured by Nippon Aerosil Co., Ltd.) Hydrophobic fumed silica whose surface has been hydrophobized with dimethyldichlorosilane. BET specific surface area: approximately 170 m 2 / g, surface carbon content (carbon content): 0.9 to 1.5 mass%, bulk density: approximately 50 g / L) (D-4): R-976 (manufactured by Nippon Aerosil Co., Ltd.) Hydrophobic fumed silica whose surface has been hydrophobized with dimethyldichlorosilane. BET specific surface area: approximately 250 m 2 / g, surface carbon content (carbon content): approx. 1.5 mass%, bulk density: approx. 50 g / L) (D-5): R-8200 (manufactured by Nippon Aerosil Co., Ltd.) Hydrophobic fumed silica whose surface has been hydrophobized with hexamethyldisilazane. BET specific surface area: approximately 160 m 2 / g, surface carbon content (carbon content): approximately 2.0 to 4.0 mass%, bulk density: approximately 140 g / L) (D-6): A-130 (manufactured by Nippon Aerosil Co., Ltd.) Hydrophilic fumed silica. BET specific surface area: approximately 130 m 2 / g, bulk density: approx. 50g / L) (D-7): A-200 (manufactured by Nippon Aerosil Co., Ltd.) Hydrophilic fumed silica. BET specific surface area: approximately 200 m 2 / g, bulk density: approx. 50g / L) (D-8): A-300 (manufactured by Nippon Aerosil Co., Ltd.) Hydrophilic fumed silica. BET specific surface area: approximately 300 m 2 / g, bulk density: approx. 50g / L)

[0144] (E) Component (E-1): 50% by mass toluene solution of 1-ethynyl-1-hydroxycyclohexane

[0145] [Examples 1 to 17, Comparative Examples 1 to 13] In Examples 1 to 17 and Comparative Examples 1 to 13, compositions were prepared as follows using the specified amounts of each component shown in Tables 3 to 6. The compositions were molded and cured according to the methods described below to produce cured products, which were then evaluated for tensile strength, elongation at break, LIMS moldability, and mold releasability.

[0146] Preparation of Compositions of Examples 1 to 17 and Comparative Examples 1 to 13 First, components (A) and (D) were mixed in the amounts shown in Tables 3 to 6 using a planetary mixer at 120°C for 1 hour. The mixture was cooled to room temperature and then subjected to two rounds of processing using a three-roll mill at room temperature. To 130 parts by mass of the resulting mixture, component (C) was added in the amount shown in Tables 3 to 6, and the mixture was mixed at room temperature for 10 minutes using a planetary mixer. Then, component (E) was added in the amount shown in Tables 3 to 6, and the mixture was mixed at room temperature for 10 minutes using a planetary mixer. Then, component (B) was added in the amount shown in Tables 3 to 6, and the mixture was mixed at room temperature for 10 minutes using a planetary mixer to obtain a composition. Component (B) was added so that the molar ratio of SiH groups in component (B) to alkenyl groups in component (A) was 1.2.

[0147] <Preparation of Cured Products of Examples 1 to 17 and Comparative Examples 1 to 13> The compositions of Examples 1 to 17 and Comparative Examples 1 to 13 were subjected to press crosslinking (primary crosslinking) at 150°C for 10 minutes to form rubber sheets with a thickness of 2.0 mm, and then subjected to oven crosslinking (secondary crosslinking) at 200°C for 4 hours to produce cured products.

[0148] <Tensile strength of cured product> The tensile strength of the cured products of Examples 1 to 17 and Comparative Examples 1 to 13 was measured in accordance with JIS K6249 and evaluated according to the following criteria. The results are shown in Tables 3 to 6. [Evaluation criteria] ◎: 10.0 MPa or more ○: 7.0 MPa or more and less than 10.0 MPa △: 4.0 MPa or more and less than 7.0 MPa ×: Less than 4.0 MPa

[0149] <Elongation at break of cured product> The elongation at break of the cured products of Examples 1 to 17 and Comparative Examples 1 to 13 was measured in accordance with JIS K6249 and evaluated based on the following criteria. The results are shown in Tables 3 to 6. [Evaluation criteria] ◎: 300% or more ○: 200% or more but less than 300% △: 100% or more but less than 200% ×: Less than 100%

[0150] <LIMS moldability / mold releasability> Using an injection molding machine (10-ton LIMS molding machine NS-10 LIMS specification, manufactured by Nissei Plastics Co., Ltd.) and a nine-cavity mold for O-rings (size 214), O-rings (size 214) were molded under the injection molding conditions shown in Table 1, with reference to JP 2005-24695 A (Patent Document 3). The moldability of each composition was evaluated using the following four-point scale. LIMS moldability consists of two evaluation items: "injection moldability" during molding processing and "appearance of the molded product" of the finished molded product, and the evaluation criteria for each were set as shown in Table 2 below. Furthermore, the ease of removing the O-rings from the mold was evaluated as mold releasability, using the criteria shown below. The results are shown in Tables 3 to 6. <Evaluation criteria for mold releasability> ◎: Very good ○: Good △: Fairly good ×: Difficult

[0151] [Table 1]

[0152] [Table 2]

[0153] [Table 3]

[0154] [Table 4]

[0155] [Table 5]

[0156] [Table 6]

Claims

1. (A) 100 parts by mass of a perfluoropolyether polymer having at least two alkenyl groups in the molecular chain, represented by the following general formula (1) or (2): Rf(L-MW a ) 2 (1) Rf(Q-(Y) b -B) 2 (2) [wherein Rf represents the following general formula (3)] 【Chemistry 1】 (In the formula, p, q, r, s, t, and u each independently represent an integer of 0 to 450, and p+q+r+s+t+u represents an integer of 20 to 450. The arrangement of the fluorooxyalkylene units enclosed in parentheses with p, q, r, s, t, and u may be block or random. v is independently an integer of 1 to 3 for each unit.) Each L is independently a single bond, an oxygen atom, a sulfur atom, or a divalent organic group; each M is independently a single bond, a nitrogen atom, a silicon atom, a carbon atom, a phosphorus atom, or a group containing any of these, or a divalent to octavalent organic group; each W is independently an alkenyl group or a monovalent organic group having an alkenyl group at the terminal; and each a is independently an integer of 1 to 7. Each Q is independently a single bond or a divalent organic group; each Y is independently a divalent organic group having an alkenyl group; each b is independently an integer of 1 to 10; and each B is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a halogen atom. (B) a fluorine-containing organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms per molecule: an amount such that the number of silicon-bonded hydrogen atoms (SiH groups) in component (B) is 0.5 to 5 moles per mole of alkenyl groups in component (A); (C) a hydrosilylation reaction catalyst: a catalytic amount, and (D) BET specific surface area is 50 m 2 / g or more: 10 to 40 parts by mass A thermosetting perfluoropolyether rubber composition comprising:

2. In the formulas (1) and (2) of the component (A), Rf is represented by the following general formula (3′): 【Chemistry 2】 (In the formula, p, q, r, s, and v are the same as defined above, and p+q+r+s is an integer of 20 to 450, and each fluorooxyalkylene unit enclosed in parentheses with p, q, r, and s may be block or random.) 2. The thermosetting perfluoropolyether rubber composition according to claim 1, wherein the perfluoropolyoxyalkylene group is represented by the formula:

3. 2. The thermosetting perfluoropolyether rubber composition according to claim 1, wherein the hydrophobic silica powder of component (D) is surface-hydrophobized with at least one organosilicon compound selected from organochlorosilanes, organoalkoxysilanes, organodisilazanes, and cyclic organopolysilazanes.

4. 2. The thermosetting perfluoropolyether rubber composition according to claim 1, wherein the surface carbon content of the hydrophobic silica powder of component (D) is 0.1 to 20% by mass of the total amount of the hydrophobic silica powder.

5. 2. The thermosetting perfluoropolyether rubber composition according to claim 1, further comprising (E) a hydrosilylation reaction inhibitor.

6. The thermosetting perfluoropolyether rubber composition according to any one of claims 1 to 5, which is for injection molding.

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