Crosslinking agent

Abstract

This novel fluorine-including organohydrosilane compound is represented by formula (1), has two or more hydrosilyl groups, has a feature wherein the inter-Si links all comprise silalkylene structures, has good compatibility with base oils, and provides a fluoropolyether-based cured product having good characteristics. (Rf is a monovalent perfluoropolyether group; A is a divalent organic group that may include at least one element selected from O, N, and Si; R is a C1-6 monovalent hydrocarbon group; n is an integer from 1 to 3; each B is a monovalent silicon-including organic group that has two or more diorganohydrosilyl groups when n is 1, independently has one or more diorganohydrosilyl groups when n is 2 or 3, and forms a silalkylene structure with the silicon atom linked thereto; and y is 1 or 2.)

Description

[Technical Field]

[0001] The present invention relates to a fluorine-containing organohydrogensilane compound that does not contain a siloxane bond and has two or more hydrosilyl groups (SiH groups) in one molecule. A crosslinking agent consisting of This compound has excellent compatibility with linear fluoropolyether compounds and is therefore suitable for use as an additive such as a crosslinking agent for fluoropolyether-based curable compositions. [Background technology]

[0002] Fluoropolyether-based curable compositions utilizing the addition reaction between alkenyl groups and hydrosilyl groups are known. For example, proposed curable compositions include a linear fluoropolyether compound (hereinafter referred to as "base oil") having two or more alkenyl groups per molecule and a perfluoropolyether structure in the main chain, a fluorine-containing organohydrogensiloxane having two or more hydrogen atoms directly bonded to silicon atoms per molecule, and a platinum group metal compound (Patent Document 1 and Patent Document 2 (JP-A-8-199070 and JP-A-2011-201940)). Furthermore, proposed compositions include a third component (adhesion improver) that is an organopolysiloxane having hydrosilyl groups and epoxy and / or trialkoxysilyl groups, thereby imparting self-adhesion to the composition (Patent Document 3 and Patent Document 4 (JP-A-9-95615 and JP-A-2011-219692)). The composition can be cured by heating for a short time, and the resulting cured product (fluoropolyether-based cured product) has excellent solvent resistance, chemical resistance, heat resistance, low-temperature properties, low moisture permeability, electrical properties, etc., and is therefore used in various industrial fields where these properties are required.

[0003] Furthermore, fluoropolyether-based curable compositions containing fluorine-containing organohydrogensiloxanes contain siloxane bonds that are unstable to acid, and therefore cannot exhibit sufficient performance in applications requiring high levels of acid resistance. In response to this, it has been proposed to improve the acid resistance of fluoropolyether-based cured products by using a fluorine-containing organohydrogensilane compound that does not contain siloxane bonds and has a short-chain perfluoroalkyl group instead of fluorine-containing organohydrogensiloxanes (Patent Document 5 (JP 2002-012769 A)).

[0004] On the other hand, in fluorine-containing organohydrogensilane compounds having perfluoroalkyl groups, the proportion of non-fluorinated organic structures in the entire molecule tends to be large.This is largely due to the convenience of synthesizing the fluorine-containing organohydrogensilane compounds and the structural constraints of perfluoroalkyl group-containing compounds that can be purchased as raw materials.In addition, the introduction of short-chain perfluoroalkyl groups tends to have little effect on imparting compatibility with base oils to organohydrogensilane compounds.For these reasons, fluorine-containing organohydrogensilane compounds containing short-chain perfluoroalkyl groups often have poor compatibility with base oils. Therefore, when the fluorine-containing organohydrogensilane compound is added to a fluoropolyether-based curable composition, the fluoropolyether-based curable composition may become cloudy and have an increased viscosity, and further, the fluoropolyether-based cured product obtained from the fluoropolyether-based curable composition may have scattered uncured portions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-199070 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-201940 [Patent Document 3] Japanese Patent Application Publication No. 9-95615 [Patent Document 4] Japanese Patent Application Laid-Open No. 2011-219692 [Patent Document 5] Japanese Patent Application Laid-Open No. 2002-012769 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and provides a fluoropolyether-based curable composition having two or more hydrosilyl groups in one molecule, having good compatibility with base oils, and providing a fluoropolyether-based cured product having good properties. to Novel fluorine-containing organohydrogensilane compounds that are preferably used A crosslinking agent consisting of The purpose is to provide the following. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems and have found that when a fluorine-containing group is introduced into an organohydrogensilane compound as a crosslinking agent for a fluoropolyether-based curable composition, the perfluoropolyether group tends to be more compatible with the base oil of the corresponding fluorine-containing organohydrogensilane compound than a perfluoroalkyl group. That is, the present inventors have found that a fluorine-containing organohydrogensilane compound obtained by introducing a compound having a monovalent perfluoropolyether group and an alkenyl group into a (fluorine-containing) organohydrogensilane compound having three or more hydrosilyl groups of a predetermined structure has high compatibility with the base oil when used as a crosslinking agent for a fluoropolyether-based curable composition and can give a fluoropolyether-based cured product with good properties, which led to the completion of the present invention.

[0008] Therefore, the present invention provides a fluoropolyether-based curable composition that has good compatibility with base oils. to Fluorine-containing organohydrogensilane compounds that are preferably used A crosslinking agent consisting of to provide. [1] A fluorine-containing organohydrogensilane compound represented by the following general formula (1), having two or more hydrosilyl groups, and in which all of the silicon atoms are linked together in a silalkylene structure: a crosslinking agent used in a fluoropolyether-based curable composition, the base oil of which contains two or more alkenyl groups in one molecule and which is composed only of a linear fluoropolyether compound having a perfluoropolyether structure in the main chain; . [ka] (wherein Rf is a monovalent perfluoropolyether group, A is a divalent group having 1 to 20 carbon atoms which may contain at least one atom selected from oxygen atoms, nitrogen atoms, and silicon atoms.) hydrocarbons base (However, when a silicon atom is contained, the silicon atom is linked to the silicon atom to which A is linked via an unsubstituted or fluorine-substituted alkylene group having 1 to 12 carbon atoms to form a silalkylene structure.) wherein R is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, n is an integer of 1 to 3, and B is The following general formula (7) [ka] [In the formula, p is an integer of 1 to 6, q is an integer of 0 to 6, r is an integer of 1 to 3, R is the same as above, and E is a hydrogen atom or a group represented by the following formula: [ka] (wherein R is the same as above, p' is an integer of 1 to 6, and q' is an integer of 0 to 6) (provided that when E is a hydrogen atom, r is 1). The repeating units shown in parentheses with p, q or p', q' above may be bonded randomly.) is a group represented by When n is 1 r is 2 or 3 , when n is 2 or 3, r is an integer between 1 and 3 and y is 1 or 2. [2] [1], wherein Rf in the general formula (1) is a group represented by the following general formula (2): Crosslinking agent . [ka] (In the formula, D is a fluorine atom or a perfluorooxyalkyl group having 1 to 6 carbon atoms; a, b, c, and d each independently represent an integer of 0 to 100, 2≦a+b+c+d≦100; and e is an integer of 1 to 3. The repeating units shown in the parentheses may be bonded randomly, and these units may be linear or branched.) [3] [1] or [2], wherein A in the general formula (1) is selected from an alkylene group having 1 to 12 carbon atoms, an alkylene group containing an arylene group having 6 to 8 carbon atoms, a divalent group in which alkylene groups are bonded to each other via a diorganosilylene group, a divalent group in which an alkylene group and an arylene group are bonded to each other via a diorganosilylene group, and a divalent group further having at least one bond selected from an ether-bonded oxygen atom, a secondary amino group, a tertiary amino group, and an amide bond in any of these groups. Crosslinking agent . [4]

[0023] In any one of [1] to [3], A in the general formula (1) is any one of groups represented by the following general formulas (3) to (6): Crosslinking agent . [ka] (In the formula, X 0 is a hydrogen atom, a methyl group, or an ethyl group, and X 1 are independently a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, or a trifluoromethyl group, and X 2 is a hydrogen atom, a methyl group, an ethyl group, or a phenyl group, R' is independently a methyl group or an ethyl group, f is an integer of 1 to 6, and t is 0 or 1. Note that the bond marked with * indicates that it is bonded to the Si atom in the above general formula (1), and the bond without a mark indicates that it is bonded to Rf. [5] [4] Any one of [1] to [4], wherein R in the general formula (1) is any one of a methyl group, an ethyl group, an isopropyl group, a tertiary butyl group, and a phenyl group. Crosslinking agent . [6]

[0023] According to any one of [1] to [5], the number of consecutive silalkylene structures in the molecular chain between Rf and the diorganohydrosilyl group in B in the general formula (1) is 2 or more. Crosslinking agent . [ 7 〕 The fluorine-containing organohydrogensilane compound represented by formula (1) is represented by the following formula [1] to [ 6 ] Crosslinking agent . [ka] [ka] [ka] [ka] [ka] [ka] (In the formula, b' is an integer of 2 to 100, c''' and d'' are each an integer of 1 to 99, c'''+d''=an integer of 2 to 100, Me is a methyl group, Et is an ethyl group, and Ph is a phenyl group. Each repeating unit shown in parentheses followed by c''' and d'' may be bonded randomly.) [8] The crosslinking agent according to [1], wherein Rf in the general formula (1) is a group represented by any one of the following formulae (2a) to (2g). [ka] (In the formula, g is an integer of 1 to 6; in formula (2a), c' is an integer of 2 to 100; in formulas (2b) to (2e), b' is an integer of 2 to 100; in formula (2f), c'' and d' are each an integer of 0 to 100, and c''+d' is an integer of 2 to 100; and in formula (2g), a' is an integer of 2 to 100. In formula (2f), the repeating units shown in parentheses may be bonded randomly.) 〔9〕 [8] The crosslinking agent according to [8], wherein b' is an integer of 2 to 24 in the above formulas (2b) to (2e). 〔10〕 The crosslinking agent according to [8], wherein b' is an integer of 2 to 8 in the formulae (2b) to (2e). 〔11〕 The crosslinking agent according to [1], wherein the fluoropolyether-based curable composition does not contain a reinforcing filler. 〔12〕 A method for improving the compatibility of a base oil with a crosslinking agent in a fluoropolyether-based curable composition, the method comprising: a base oil consisting solely of a linear fluoropolyether compound having two or more alkenyl groups per molecule and a perfluoropolyether structure in the main chain; and a crosslinking agent, the method comprising using, as the crosslinking agent, a fluorine-containing organohydrogensilane compound represented by the following general formula (1), having two or more hydrosilyl groups, and in which all of the links between silicon atoms consist of a silalkylene structure: [ka] (In the formula, Rf is a monovalent perfluoropolyether group, A is a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from oxygen atoms, nitrogen atoms, and silicon atoms (provided that when a silicon atom is contained, the silicon atom is linked to the silicon atom to which A is linked via an unsubstituted or fluorine-substituted alkylene group having 1 to 12 carbon atoms to form a silalkylene structure), R is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, n is an integer of 1 to 3, and B is a group represented by the following general formula (7): [ka] [In the formula, p is an integer of 1 to 6, q is an integer of 0 to 6, r is an integer of 1 to 3, R is the same as above, and E is a hydrogen atom or a group represented by the following formula: [ka] (wherein R is the same as above, p' is an integer of 1 to 6, and q' is an integer of 0 to 6) (provided that when E is a hydrogen atom, r is 1). The repeating units shown in parentheses with p, q or p', q' above may be bonded randomly.) When n is 1, r is 2 or 3, and when n is 2 or 3, r is independently an integer of 1 to 3, and y is 1 or 2. [Effects of the Invention]

[0009] The fluorine-containing organohydrogensilane compound of the present invention does not contain a siloxane bond and exhibits high compatibility with the base oil in the fluoropolyether-based curable composition, thereby preventing the fluoropolyether-based curable composition from becoming cloudy or thickening. Furthermore, by curing the fluoropolyether-based curable composition using the fluorine-containing organohydrogensilane compound of the present invention, a uniformly cured fluoropolyether-based cured product without scattered uncured portions can be obtained. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a 1H-NMR spectrum of the compound represented by formula (18) obtained in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in further detail below. [Fluorine-containing organohydrogensilane compounds] The fluorine-containing organohydrogensilane compound according to the present invention is represented by the following general formula (1), and is characterized in that it is a compound having two or more hydrosilyl groups, and in which all of the bonds between silicon atoms are formed by a silalkylene structure (note that the alkylene groups in the silalkylene structure may be fluorine-substituted alkylene groups that are partially substituted with fluorine), and does not contain siloxane bonds. [ka] (In the formula, Rf is a monovalent perfluoropolyether group, A is a divalent organic group having 1 to 20 carbon atoms which may contain at least one atom selected from oxygen atoms, nitrogen atoms, and silicon atoms, R is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, n is an integer of 1 to 3, B is a monovalent silicon-containing organic group which, when n is 1, has two or more diorganohydrosilyl groups, or when n is 2 or 3, independently has one or more diorganohydrosilyl groups and forms a silalkylene structure with the silicon atom to which it is linked, and y is 1 or 2.)

[0012] In the general formula (1), Rf is a monovalent perfluoropolyether group. Rf is introduced to impart compatibility with the base oil in a fluoropolyether-based curable composition (especially a thermosetting fluoropolyether-based composition). Compared with a perfluoroalkyl group, the perfluoropolyether group has a greater effect of imparting compatibility with the base oil when introduced into an organohydrogensilane compound, thereby making it possible to obtain a fluorine-containing organohydrogensilane compound that gives a fluoropolyether-based cured product with good properties.

[0013] In particular, Rf in the above general formula (1) is preferably a monovalent perfluoropolyether group represented by the following general formula (2). [ka] (In the formula, D represents a fluorine atom or a perfluorooxyalkyl group having 1 to 6 carbon atoms; a, b, c, and d each independently represent an integer of 0 to 100, and 2≦a+b+c+d≦100; preferably, a represents an integer of 0 to 50, b represents an integer of 0 to 50, c represents an integer of 0 to 50, and d represents an integer of 0 to 50, and 5≦a+b+c+d≦50; more preferably, a represents an integer of 0 to 10, b represents an integer of 0 to 40, c represents an integer of 0 to 30, and d represents an integer of 0 to 30, and 6≦a+b+c+d≦40; still more preferably, 7≦a+b+c+d≦30; and e represents an integer of 1 to 3. The repeating units shown in the parentheses above may be bonded randomly, and these units may be linear or branched.)

[0014] In the above general formula (2), D is a fluorine atom or a perfluorooxyalkyl group having 1 to 6 carbon atoms. The perfluorooxyalkyl group having 1 to 6 carbon atoms includes C g F 2g+1 O- (g is an integer of 1 to 6), and specific examples include groups represented by the following formulas. CF3O- CF3CF2O- CF3CF2CF2O- CF3CF(CF3)O- CF3CF2CF2CF2O- CF3CF2CF2CF2CF2CF2O- D is preferably a fluorine atom.

[0015] In the above general formula (2), if a+b+c+d is less than 2, the compatibility of the fluorine-containing organohydrogensilane compound with the base oil may decrease, which is undesirable. On the other hand, if a+b+c+d is greater than 100, the viscosity of the fluorine-containing organohydrogensilane compound increases, and the viscosity of the thermosetting fluoropolyether composition containing the fluorine-containing organohydrogensilane compound also increases too much, which is undesirable.

[0016] Examples of the monovalent perfluoropolyether group represented by the above general formula (2) include the following. [ka] (In the formula, g is an integer of 1 to 6; in formula (2a), c' is an integer of 2 to 100; in formulas (2b) to (2e), b' is an integer of 2 to 100; in formula (2f), c'' and d' are each an integer of 0 to 100, and c''+d' is an integer of 2 to 100; and in formula (2g), a' is an integer of 2 to 100. In formula (2f), the repeating units shown in parentheses may be bonded randomly.)

[0017] In the above general formula (1), A is a divalent organic group having 1 to 20 carbon atoms which may contain at least one selected from an oxygen atom, a nitrogen atom, and a silicon atom, preferably a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain at least one selected from an oxygen atom, a nitrogen atom, and a silicon atom, and is preferably an alkylene group having 1 to 12 carbon atoms, an alkylene group having 1 to 12 carbon atoms including an arylene group having 6 to 8 carbon atoms (for example, an alkylene-arylene group having 7 to 18 carbon atoms), or an alkylene group having 1 to 10 carbon atoms bonded to each other via a diorganosilylene group. Examples of such groups include a divalent group having an ether-bonded oxygen atom, a divalent group having an alkylene group having 1 to 10 carbon atoms and an arylene group having 6 to 8 carbon atoms bonded via a diorganosilylene group, and a divalent group further having at least one bond selected from an ether-bonded oxygen atom, a secondary amino group (imino group), a tertiary amino group (substituted imino group), and an amide bond. Of these, a divalent group containing at least one bond selected from an ether-bonded oxygen atom, a secondary amino group (imino group), a tertiary amino group (substituted imino group), and an amide bond within the molecular chain is preferred. When A contains a silicon atom (diorganosilylene group), it is preferred that the silicon atom (diorganosilylene group) and the silicon atom to which A is linked form a silalkylene structure in which the silicon atom (diorganosilylene group) is linked via an alkylene group (preferably an unsubstituted or fluorine-substituted alkylene group having 1 to 12 carbon atoms, more preferably an ethylene group).

[0018] Specifically, A is preferably represented by any one of the following general formulas (3) to (6). [ka] (In the formula, X 0 is a hydrogen atom, a methyl group, or an ethyl group, and X 1 are independently a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, or a trifluoromethyl group, and X 2 is a hydrogen atom, a methyl group, an ethyl group, or a phenyl group, R' is independently a methyl group or an ethyl group, f is an integer of 1 to 6, and t is 0 or 1. Note that the bond marked with * indicates that it is bonded to the Si atom in the above general formula (1), and the bond without a mark indicates that it is bonded to Rf.

[0019] Examples of the structure of A represented by the above general formulas (3) to (6) include the following. [ka] [ka] [ka] [ka] (In the formula, Me is a methyl group, and Et is an ethyl group. Note that the bond marked with * indicates that it is bonded to the Si atom in the above general formula (1), and the bond without a mark indicates that it is bonded to Rf.)

[0020] In the general formula (1), R is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, and specifically, is preferably a methyl group, an ethyl group, an isopropyl group, a tertiary butyl group, or a phenyl group, and more preferably a methyl group or an ethyl group.

[0021] In the general formula (1), B has two or more, preferably 2 to 5, diorganohydrosilyl groups when n is 1, and independently has one or more, preferably 1 to 3, diorganohydrosilyl groups when n is 2 or 3. B is a monovalent silicon-containing organic group that forms a silalkylene structure with the silicon atom to which it is linked, and does not contain a siloxane bond. The silalkylene structure is formed by connecting silicon atoms to each other through an unsubstituted and / or fluorine-substituted alkylene group R having 1 to 12 carbon atoms. A Preferably, B has a structure in which B is linked via the following: Furthermore, B preferably has one or more silicon atoms, more preferably 1 to 6, and even more preferably 1 to 4. In formula (1), 1 to 3 such Bs are bonded to silicon atoms (n = an integer of 1 to 3), and preferably 2 or 3 are bonded (preferably, n is 2 or 3).

[0022] In addition, the continuous silalkylene structure in the molecular chain between Rf and the diorganohydrosilyl group in B in the general formula (1) (i.e., -A-Si-, -Si-(CH2) y Consecutive silalkylene bonds (-Si-R A The number of —Si—) is preferably 2 or more, and more preferably 2, 3 or 4.

[0023] B is preferably represented by the following general formula (7). [ka] [In the formula, p is an integer of 1 to 6, preferably an integer of 1 to 4; q is an integer of 0 to 6, preferably 0 or an integer of 4 to 6; r is an integer of 1 to 3; R is the same as above; E is a hydrogen atom or a group represented by the following formula: [ka] (wherein R is the same as above, p' is an integer of 1 to 6, preferably an integer of 1 to 4, and q' is an integer of 0 to 6, preferably an integer of 0 or 4 to 6) (provided that when E is a hydrogen atom, r is 1). The repeating units shown in parentheses with p, q or p', q' above may be bonded randomly.)

[0024] R in the general formula (7) is a monovalent hydrocarbon group having 1 to 6 carbon atoms, similar to R in the general formula (1), and among these, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tertiary butyl group, and a phenyl group are particularly preferred.

[0025] Examples of B in the above general formula (1) include the following. [ka] [ka] [ka] (In the formula, Me is a methyl group, Et is an ethyl group, iPr is an isopropyl group, tBu is a tertiary butyl group, and Ph is a phenyl group.)

[0026] The amount of hydrosilyl groups in the fluorine-containing organohydrogensilane compound of the present invention is preferably 0.05 to 0.35 mol / 100 g, and more preferably 0.06 to 0.30 mol / 100 g.

[0027] Examples of the fluorine-containing organohydrogensilane compound represented by the above general formula (1) include the following. [ka] [ka] [ka] [ka] [ka] [ka] (In the formula, b' is an integer of 2 to 100, c''' and d'' are each an integer of 1 to 99, c'''+d''=an integer of 2 to 100, Me is a methyl group, Et is an ethyl group, and Ph is a phenyl group. Each repeating unit shown in parentheses followed by c''' and d'' may be bonded randomly.)

[0028] [Method for producing fluorine-containing organohydrogensilane compounds] The method of the present invention for producing the fluorine-containing organohydrogensilane compound represented by the above general formula (1) preferably comprises a step of introducing two or more diorganohydrosilyl groups into the fluorine-containing compound through a predetermined linking structure by a hydrosilylation reaction using, for example, an alkenyl group (vinyl group)-containing fluorine-containing compound represented by the following general formula (1A) and an organohydrogensilane compound having at least three diorganohydrosilyl groups represented by the following general formula (1B): [ka] [ka]

[0029] In general formula (1A), A 2 is a divalent organic group having 1 to 18 carbon atoms which may contain at least one atom selected from an oxygen atom, a nitrogen atom, and a silicon atom. The explanations for Rf, R, B, y, and n in the above general formulas (1A) and (1B) are the same as the explanations for Rf, R, B, y, and n in the above general formula (1). That is, in the above general formulas (1A) and (1B), Rf is a monovalent perfluoropolyether group, R is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, n is an integer of 1 to 3, B is a monovalent silicon-containing organic group which has two or more diorganohydrosilyl groups when n is 1, or independently has one or more diorganohydrosilyl groups when n is 2 or 3, and forms a silalkylene structure with the silicon atom to which it is linked, and y is 1 or 2.

[0030] A 2is a divalent organic group having 1 to 18 carbon atoms which may contain at least one atom selected from an oxygen atom, a nitrogen atom, and a silicon atom, and is an alkylene group having 1 to 10 carbon atoms, an alkylene group having 1 to 10 carbon atoms containing an arylene group having 6 to 8 carbon atoms (for example, an alkylene-arylene group having 6 to 18 carbon atoms), a divalent group in which a diorganosilylene group is bonded to an alkylene group having 1 to 10 carbon atoms, a divalent group in which a diorganosilylene group is bonded to an arylene group having 6 to 8 carbon atoms, a divalent group in which an alkylene group having 1 to 10 carbon atoms and an alkylene group having 1 to 8 carbon atoms are bonded to a diorganosilylene group, and a divalent group in which an alkylene group having 1 to 8 carbon atoms and an arylene group having 6 to 8 carbon atoms are bonded via a diorganosilylene group; and a divalent group in which these groups further contain at least one bond selected from an ether-bonded oxygen atom, a secondary amino group (imino group), a tertiary amino group (substituted imino group), and an amide bond. Of these, a divalent group containing at least one bond selected from an ether-bonded oxygen atom, a secondary amino group (imino group), a tertiary amino group (substituted imino group), and an amide bond within the molecular chain is preferred.

[0031] A 2 Specifically, those represented by any of the following general formulas (8) to (15) are preferred. [ka] [ka] (In the formula, X 0 is a hydrogen atom, a methyl group, or an ethyl group, and X 1 are independently a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, or a trifluoromethyl group, and X 2 is a hydrogen atom, a methyl group, an ethyl group, or a phenyl group, f' is an integer of 0 to 4, and f'' is an integer of 1 to 6. The bond marked with a wavy line is bonded to the vinyl group in the above general formula (1A), and the unmarked bond is bonded to Rf.

[0032] A represented by the above general formulas (8) to (15) 2Examples of the structure include the following: [ka] [ka] [ka] [ka] (In the formula, Me is a methyl group, and Et is an ethyl group. The bond marked with a wavy line is bonded to the vinyl group in the above general formula (1A), and the unmarked bond is bonded to Rf.)

[0033] The production steps (reaction formula) of a preferred method for producing a fluorine-containing organohydrogensilane compound according to the present invention are shown below. [ka]

[0034] The explanations for Rf, A, R, B, y, and n in the reaction formula shown in the above step are the same as those for Rf, A, R, B, y, and n in the general formula (1) above. 2 The explanation of A in the above general formula (1A) 2 The same as the explanation for M. M is a metal catalyst.

[0035] In the above step, a fluorine-containing compound represented by the above general formula (1A) and having an alkenyl group (preferably a vinyl group or an allyl group) at the terminal of the molecular chain is subjected to a hydrosilylation reaction with an organohydrogensilane compound represented by the above general formula (1B) and having at least three diorganohydrosilyl groups in the molecule in the presence of a metal catalyst (M) to produce a fluorine-containing organohydrogensilane compound represented by the above general formula (1).

[0036] In the above reaction, the following compounds can be used, for example, as the fluorine-containing compound represented by the above general formula (1A) and having an alkenyl group (preferably a vinyl group or an allyl group) at the molecular chain terminal. [ka] (In the formula, b' is an integer of 2 to 100, c''' and d'' are each an integer of 1 to 99, c'''+d''=an integer of 2 to 100, Me is a methyl group, and Et is an ethyl group. Each repeating unit shown in parentheses followed by c''' and d'' may be bonded randomly.)

[0037] As the organohydrogensilane compound represented by the above general formula (1B) and having at least three diorganohydrosilyl groups in the molecule, for example, the following compounds can be used. [ka] [ka] (In the formula, Me is a methyl group, Et is an ethyl group, and Ph is a phenyl group.)

[0038] Furthermore, the hydrosilylation in the above reaction step can be accelerated by adding M (metal catalyst). M is not particularly limited as long as it is a metal catalyst capable of catalyzing hydrosilylation, but compounds containing metal atoms such as platinum, rhodium, ruthenium, and palladium are suitable. For example, chloroplatinic acid or a complex of chloroplatinic acid with an olefin such as ethylene, a complex of chloroplatinic acid with an alcohol or vinylsiloxane, metallic platinum supported on silica, alumina, carbon, or the like, RhCl(PPh3)3, RhCl(CO)(PPh3)2, Ru3(CO) 12 Examples include IrCl(CO)(PPh3)2, Pd(PPh3)4, etc. In the above formula, Ph is a phenyl group. Among them, platinum compounds are particularly preferred.

[0039] When using these catalysts, if they are solid catalysts, they can be used in solid form, but to promote the reaction more rapidly, it is preferable to use the metal catalyst dissolved in an appropriate solvent. It is desirable to add the catalyst dropwise after confirming that the system containing the fluorine-containing compound represented by the above general formula (1A) and having an alkenyl group (preferably a vinyl group or an allyl group) at the molecular chain terminal and the organohydrogensilane compound represented by the above general formula (1B) and having at least three diorganohydrosilyl groups in the molecule is heated to a predetermined temperature. The predetermined temperature is preferably 50°C or higher, more preferably 65°C or higher.

[0040] When the fluorine-containing compound represented by the above general formula (1A) and having an alkenyl group (preferably a vinyl group or an allyl group) at the molecular chain terminal or the organohydrogensilane compound represented by the above general formula (1B) and having at least three diorganohydrosilyl groups in the molecule is solid or when the compounds are insoluble with each other, they may be dissolved in a small amount of organic solvent and then M (metal catalyst) is added. Usable solvents include benzene, toluene, xylene, 1,3-bistrifluoromethylbenzene, etc., and 1,3-bistrifluoromethylbenzene is preferred.

[0041] The amount of the fluorine-containing compound represented by the general formula (1A) and having an alkenyl group (preferably a vinyl group or an allyl group) at the molecular chain terminal is such that the amount of alkenyl groups in the fluorine-containing compound is 0.16 to 0.30 equivalents, preferably 0.20 to 0.25 equivalents, relative to the amount of hydrosilyl groups in the compound represented by the general formula (1B). If the amount of alkenyl groups in the fluorine-containing compound is less than 0.16 equivalents relative to the amount of hydrosilyl groups in the compound represented by the general formula (1B), the resulting fluorine-containing organohydrogensilane compound may become cloudy or thicken when added to a thermosetting fluoropolyether-based curable composition, or the cured product obtained by heat curing may have undesirable features such as scattered uncured areas on the surface. Furthermore, if the amount of alkenyl groups in the fluorine-containing compound is more than 0.30 equivalents relative to the amount of hydrosilyl groups in the compound represented by the general formula (1A), the amount of hydrosilyl groups in the resulting fluorine-containing organohydrogensilane compound will be too small, making it difficult to cure the thermosetting fluoropolyether-based curable composition, which is not preferred.

[0042] The fluorine-containing organohydrogensilane compound of the present invention obtained as described above does not contain a siloxane bond, exhibits high compatibility with the base oil in the fluoropolyether curable composition, and can suppress the opacity and viscosity increase of the fluoropolyether curable composition. Furthermore, by curing the fluoropolyether curable composition using this fluorine-containing organohydrogensilane compound as a crosslinking agent, a uniformly cured fluoropolyether cured product without scattered uncured portions can be obtained. [Example]

[0043] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following examples, Me represents a methyl group, and parts represent parts by mass. The amounts of vinyl groups and hydrosilyl groups are respectively 1 The number average molecular weight of the alkenyl group-containing perfluoropolyether compound (base oil) was measured by H-NMR. 19The viscosity was calculated from F-NMR. The viscosity was measured at 23°C using a rotational viscometer.

[0044] Synthesis of fluorine-containing organohydrogensilane compounds [Example 1] In a 1 L flask, an organohydrogensilane compound (hydrosilyl group amount 0.616 mol / 100 g) represented by the following formula (16) was added. [ka] 150g and a compound represented by the following formula (17) (vinyl group amount 0.0681mol / 100g) [ka] 339g of a distillate and 91g of 1,3-bistrifluoromethylbenzene were charged, and the atmosphere was purged with nitrogen. After heating to 70°C, 0.16 g of (C1) a toluene solution of platinum-divinyltetramethyldisiloxane complex (platinum concentration 0.5% by mass) was added dropwise and stirred at 85°C for 1 hour. The reaction solution was quenched and concentrated under reduced pressure. The resulting residue was dissolved in FC-3283 (524 g) and stirred with 9.10 g of activated carbon (Shirasagi AS, manufactured by Osaka Gas Chemicals) for 1 hour, followed by filtration. Activated carbon (9.10 g) was added to the resulting solution, stirred for 1 hour, and then filtered. The main component was extracted from the obtained solution by preparative liquid chromatography, and then concentrated under reduced pressure to obtain a compound represented by the following formula (18) (hydrosilyl group amount: 0.143 mol / 100 g): [ka] The obtained compound was 376 g. 1 The H-NMR spectrum is shown in Figure 1. As shown in Figure 1, the following signals were observed in the obtained product: δ 7.86-6.55 (m, 4H), 4.38-3.64 (m, 3H), 3.15 (s, 3H), 2.46-1.48 (br, 4H), 1.18--0.91 (m, 52H), confirming the production of the compound represented by formula (18) above.

[0045] [Example 2] Instead of the compound represented by the formula (17), a compound represented by the following formula (19) (vinyl group amount: 0.0228 mol / 100 g) [ka] The same procedure as in Example 1 was repeated except that 1,012 g of the compound represented by the following formula (20) (amount of hydrosilyl group: 0.0682 mol / 100 g) was used. [ka] 741 g of the obtained product 1 The H-NMR spectrum confirmed the following signals: δ 7.68-6.36 (m, 4H), 4.21-3.44 (s, 3H), 3.03 (s, 3H), 2.29-1.41 (br, 4H), 1.13--0.98 (m, 52H), confirming the production of the compound represented by formula (20) above.

[0046] [Example 3] Instead of the compound represented by the formula (16), a compound represented by the following formula (21) (hydrosilyl group amount: 1.09 mol / 100 g) [ka] The same procedure as in Example 1 was repeated except that 85 g of the compound represented by the following formula (22) (amount of hydrosilyl group: 0.247 mol / 100 g) was used. [ka] 323 g of the obtained product 1 The H-NMR spectrum confirmed the following signals: δ 7.85 to 6.55 (m, 4H), 4.29 to 3.51 (m, 5H), 3.15 (s, 3H), and 1.23 to −0.91 (m, 62H), confirming the production of the compound represented by formula (22).

[0047] [Example 4] Instead of the compound represented by the formula (17), a compound represented by the following formula (23) (vinyl group amount: 0.0710 mol / 100 g) [ka] The same procedure as in Example 1 was repeated except that 325 g of the compound represented by the following formula (24) (amount of hydrosilyl group: 0.147 mol / 100 g) was used. [ka] 294 g of the product was obtained. 1 The H-NMR spectrum confirmed the following signals: δ 6.92-6.62 (s, 1H), 4.40-3.67 (m, 3H), 3.42-3.06 (m, 2H), 2.47-1.47 (br, 4H), 1.75-1.39 (m, 2H), and 1.18--0.90 (m, 54H), confirming the production of the compound represented by formula (24).

[0048] [Example 5] Instead of the compound represented by the formula (17), a compound represented by the following formula (25) (vinyl group amount: 0.0873 mol / 100 g) [ka] (average of d1+c1=12, d1:c1=0.98:1) The same procedure as in Example 1 was repeated except that 264 g of the compound represented by the following formula (26) (amount of hydrosilyl group: 0.169 mol / 100 g) was used. [ka] (average of d1+c1=12, d1:c1=0.98:1) The following signals were confirmed in the 1H-NMR spectrum of the obtained product: δ 6.89-6.61 (s, 1H), 4.39-3.66 (m, 3H), 3.41-3.07 (m, 2H), 2.46-1.47 (br, 4H), 1.74-1.39 (m, 2H), 1.18--0.90 (m, 54H), confirming the production of the compound represented by the above formula (26).

[0049] <Preparation of thermosetting fluoropolyether composition and confirmation of compatibility of fluorine-containing organohydrogensilane compound with base oil> [Example 6] A thermosetting fluoropolyether composition was prepared by adding 0.1 parts of a toluene solution of platinum-divinyltetramethyldisiloxane complex (platinum concentration 0.5% by mass), 0.07 parts of a compound represented by formula (28) below, and 9.74 parts of a compound represented by formula (18) above to 100 parts of a base oil represented by formula (27) below (number average molecular weight 15,550, mass loss rate 0.5%, viscosity 10,900 mPa s, vinyl group content 0.012 mol / 100 g), mixing, and degassing under reduced pressure. The thermosetting fluoropolyether composition obtained was a colorless, transparent oil, confirming that the fluorine-containing organohydrogensilane compound represented by formula (18) above has high compatibility with the base oil. [ka] (v and w are each an integer of 1 or greater, and the average value of v+w is 90.) [ka]

[0050] [Example 7] A thermosetting fluoropolyether composition was prepared in the same manner as in Example 6, except that 20.42 parts of the compound represented by formula (20) was used instead of the compound represented by formula (18). The thermosetting fluoropolyether composition was obtained as a colorless, transparent oil, confirming that the fluorine-containing organohydrogensilane compound represented by formula (20) has high compatibility with the base oil.

[0051] [Example 8] A thermosetting fluoropolyether composition was prepared in the same manner as in Example 6, except that 5.73 parts of the compound represented by formula (22) was used instead of the compound represented by formula (18). The thermosetting fluoropolyether composition was obtained as a colorless, transparent oil, confirming that the fluorine-containing organohydrogensilane compound represented by formula (22) has high compatibility with the base oil.

[0052] [Example 9] A thermosetting fluoropolyether composition was prepared in the same manner as in Example 6, except that 9.47 parts of the compound represented by formula (24) was used instead of the compound represented by formula (18). The thermosetting fluoropolyether composition was obtained as a colorless, transparent oil, confirming that the fluorine-containing organohydrogensilane compound represented by formula (24) has high compatibility with the base oil.

[0053] [Example 10] A thermosetting fluoropolyether composition was prepared in the same manner as in Example 6, except that 8.24 parts of the compound represented by formula (26) was used instead of the compound represented by formula (18). The thermosetting fluoropolyether composition was obtained as a colorless, transparent oil, confirming that the fluorine-containing organohydrogensilane compound represented by formula (26) has high compatibility with the base oil.

[0054] [Comparative Example 1] A thermosetting fluoropolyether composition was prepared in the same manner as in Example 6, except that 2.26 parts of the compound represented by formula (16) was used instead of the compound represented by formula (18). The thermosetting fluoropolyether composition was obtained as a cloudy oil, confirming that the fluorine-containing organohydrogensilane compound represented by formula (16) had poor compatibility with the base oil.

[0055] Comparative Example 2 A thermosetting fluoropolyether composition was prepared in the same manner as in Example 6, except that 2.61 parts of a compound represented by the following formula (29) (hydrosilyl group amount: 0.532 mol / 100 g) was used instead of the compound represented by the above formula (18). The thermosetting fluoropolyether composition was obtained as a cloudy oil, confirming that the fluorine-containing organohydrogensilane compound represented by the following formula (29) had poor compatibility with the base oil. [ka]

[0056] Comparative Example 3 A thermosetting fluoropolyether composition was prepared in the same manner as in Example 6, except that 3.52 parts of a compound represented by the following formula (30) (Patent Document 5: the compound described in Example 1 of JP-A No. 2002-012769, hydrosilyl group amount: 0.408 mol / 100 g) was used instead of the compound represented by the above formula (18). The thermosetting fluoropolyether composition obtained was a slightly cloudy, translucent oil, confirming that the fluorine-containing organohydrogensilane compound represented by the following formula (30) had poor compatibility with the base oil. [ka]

[0057] <Presence or absence of oily components on the surface of cured fluoropolyether> The thermosetting fluoropolyether compositions prepared in Examples 6 to 10 and Comparative Examples 1 to 3 were poured into a 2 mm thick stainless steel mold placed on a Teflon (registered trademark, the same applies hereinafter) sheet, sandwiched between other Teflon sheets, and press-cured at 150°C for 10 minutes. After press-curing, the 2 mm thick stainless steel mold was removed, and the remaining oily components on the surface of the resulting cured fluoropolyether were evaluated according to the following criteria. The results are shown in Table 1. [Evaluation criteria] ◯: When the surface of the cured product was peeled off from the Teflon sheet and checked by visual inspection and touch with the fingers, no remaining oily components were found. ×: When the surface of the cured product was peeled off from the Teflon sheet and inspected visually and by touch with the fingers, residual oily components were found.

[0058] [Table 1]

[0059] In Examples 6 to 10, no scattered uncured oily components were found on the surface of the cured fluoropolyether products obtained from each thermosetting fluoropolyether composition. On the other hand, scattered uncured oily components were found on the surface of the cured fluoropolyether products obtained from the thermosetting fluoropolyether compositions of Comparative Examples 1 to 3. This is thought to be because the fluorine-containing organohydrogensilane compounds represented by the above formulas (16), (29), and (30) have poor compatibility with the base oil, and some parts did not react with the base oil during thermal curing, leaving the oily components on the surface of the cured fluoropolyether products.

Claims

1. A crosslinking agent used in a fluoropolyether-based curable composition, which is composed of a fluorine-containing organohydrogensilane compound represented by the following general formula (1), which has two or more hydrosilyl groups and in which all of the links between silicon atoms have a silalkylene structure, and in which the base oil contains only a linear fluoropolyether compound having two or more alkenyl groups per molecule and a perfluoropolyether structure in the main chain: 【Chemical 1】 (In the formula, Rf is a monovalent perfluoropolyether group, A is a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from oxygen atoms, nitrogen atoms, and silicon atoms (however, when a silicon atom is contained, the silicon atom is linked to the silicon atom to which A is linked via an unsubstituted or fluorine-substituted alkylene group having 1 to 12 carbon atoms to form a silalkylene structure), R is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, n is an integer of 1 to 3, and B is a group represented by the following general formula (7): 【Chemistry 4】 [In the formula, p is an integer of 1 to 6, q is an integer of 0 to 6, r is an integer of 1 to 3, R is the same as above, and E is a hydrogen atom or a group represented by the following formula: 【Chemistry 5】 (wherein R is the same as above, p' is an integer of 1 to 6, and q' is an integer of 0 to 6) (provided that when E is a hydrogen atom, r is 1). The repeating units shown in parentheses with p, q or p', q' may be bonded randomly.] When n is 1, r is 2 or 3, and when n is 2 or 3, r is independently an integer from 1 to 3, and y is 1 or 2.

2. 2. The crosslinking agent according to claim 1, wherein Rf in the general formula (1) is a group represented by the following general formula (2): 【Chemistry 2】 (In the formula, D is a fluorine atom or a perfluorooxyalkyl group having 1 to 6 carbon atoms; a, b, c, and d each independently represent an integer of 0 to 100, with 2≦a+b+c+d≦100; and e is an integer of 1 to 3. The repeating units shown in the parentheses may be bonded randomly, and these units may be linear or branched.)

3. 3. The crosslinking agent according to claim 1 or 2, wherein A in the general formula (1) is selected from the group consisting of an alkylene group having 1 to 12 carbon atoms, an alkylene group containing an arylene group having 6 to 8 carbon atoms, a divalent group in which alkylene groups are bonded to each other via a diorganosilylene group, a divalent group in which an alkylene group and an arylene group are bonded to each other via a diorganosilylene group, and a divalent group further having at least one bond selected from an ether-bonded oxygen atom, a secondary amino group, a tertiary amino group, and an amide bond in any of these groups.

4. 3. The crosslinking agent according to claim 1, wherein A in the general formula (1) is any one of groups represented by the following general formulas (3) to (6): 【Chemistry 3】 (In the formula, X 0 is a hydrogen atom, a methyl group, or an ethyl group, and X 1 are independently a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, or a trifluoromethyl group, and X 2 is a hydrogen atom, a methyl group, an ethyl group, or a phenyl group, R' is independently a methyl group or an ethyl group, f is an integer of 1 to 6, and t is 0 or 1. Note that the bond marked with * indicates that it is bonded to the Si atom in the above general formula (1), and the bond without a mark indicates that it is bonded to Rf.

5. 3. The crosslinking agent according to claim 1, wherein R in the general formula (1) is any one of a methyl group, an ethyl group, an isopropyl group, a tertiary butyl group, and a phenyl group.

6. 3. The crosslinking agent according to claim 1, wherein the number of consecutive silalkylene structures in the molecular chain between Rf and the diorganohydrosilyl group in B in general formula (1) is two or more.

7. 3. The crosslinking agent according to claim 1, wherein the fluorine-containing organohydrogensilane compound represented by formula (1) is represented by the following formula: 【Chemistry 6】 【Chemistry 7】 【Chemistry 8】 【Chemistry 9】 【Chemistry 10】 【Chemistry 11】 (In the formula, b' is an integer of 2 to 100, c''' and d'' are each an integer of 1 to 99, c'''+d''=an integer of 2 to 100, Me is a methyl group, Et is an ethyl group, and Ph is a phenyl group. Each repeating unit shown in parentheses followed by c''' and d'' may be bonded randomly.)

8. 2. The crosslinking agent according to claim 1, wherein Rf in the general formula (1) is a group represented by any one of the following formulas (2a) to (2g): 【Chemistry 12】 (In the formulas, g is an integer of 1 to 6; in formula (2a), c' is an integer of 2 to 100; in formulas (2b) to (2e), b' is an integer of 2 to 100; in formula (2f), c'' and d' are each an integer of 0 to 100, and c''+d' is an integer of 2 to 100; and in formula (2g), a' is an integer of 2 to 100. In formula (2f), the repeating units shown in parentheses may be bonded randomly.)

9. 9. The crosslinking agent according to claim 8, wherein in the formulas (2b) to (2e), b' is an integer of 2 to 24.

10. 9. The crosslinking agent according to claim 8, wherein b' is an integer of 2 to 8 in the formulas (2b) to (2e).

11. 2. The crosslinking agent according to claim 1, wherein the fluoropolyether-based curable composition does not contain a reinforcing filler.

12. A method for improving the compatibility of a fluoropolyether-based curable composition containing a base oil consisting solely of a linear fluoropolyether compound having two or more alkenyl groups per molecule and a perfluoropolyether structure in the main chain, and a crosslinking agent, the method comprising using, as the crosslinking agent, a fluorine-containing organohydrogensilane compound represented by the following general formula (1), having two or more hydrosilyl groups, and in which all of the links between silicon atoms consist of a silalkylene structure: 【Chemistry 13】 (In the formula, Rf is a monovalent perfluoropolyether group, A is a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain at least one atom selected from oxygen atoms, nitrogen atoms, and silicon atoms (however, when a silicon atom is contained, the silicon atom is linked to the silicon atom to which A is linked via an unsubstituted or fluorine-substituted alkylene group having 1 to 12 carbon atoms to form a silalkylene structure), R is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, n is an integer of 1 to 3, and B is a group represented by the following general formula (7): 【Chemistry 14】 [In the formula, p is an integer of 1 to 6, q is an integer of 0 to 6, r is an integer of 1 to 3, R is the same as above, and E is a hydrogen atom or a group represented by the following formula: 【Chemistry 15】 (wherein R is the same as above, p' is an integer of 1 to 6, and q' is an integer of 0 to 6) (provided that when E is a hydrogen atom, r is 1). The repeating units shown in parentheses with p, q or p', q' may be bonded randomly.] When n is 1, r is 2 or 3, and when n is 2 or 3, r is independently an integer from 1 to 3, and y is 1 or 2.

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