Patent FR-2825709-A1 (FR)
Title: Silicone composition crosslinkable by hydrosilylation of an ethylenically or acetylenically unsaturated polyorganosiloxane with a polyorganohydrogenosiloxane in the presence of a carbene complex catalyst
Inventor: GEORGE CATHERINE
IPC: C08L83/04
Filed: 2001-06-07
Abstract: Silicone composition crosslinkable by hydrosilylation of an ethylenically or acetylenically unsaturated polyorganosiloxane with a polyorganohydrogenosiloxane in the presence of a catalyst comprises a Group VIII metal carbene complex (I) as the catalyst.  Silicone composition crosslinkable by hydrosilylation of an ethylenically or acetylenically unsaturated polyorganosiloxane with a polyorganohydrogenosiloxane in the presence of a catalyst and optionally a silylation inhibitor comprises a compound of formula (I) as the catalyst:  M  = a Group VIII metal;  L3  = a carbene of formula (II):  A, B  = C or N;  T3, T4  = H; alkyl; cycloalkyl optionally substituted by alkyl or alkoxy; aryl optionally substituted by alkyl or alkoxy; alkenyl; alkynyl; or aralkyl optionally ring-substituted by alkyl or alkoxy; or T3+T4 forms an aryl ring;  T1, T2  = alkyl; perfluoroalkyl; perfluoroalkyl-substituted alkyl; cycloalkyl optionally substituted by alkyl or alkoxy; aryl optionally substituted by alkyl or alkoxy; alkenyl; alkynyl; aralkyl optionally ring-substituted by alkyl or alkoxy; -V1-V2; or -W1-W-W2;  V1  = a divalent hydrocarbon group;  V2 = OH, alkoxy, aryloxy or amine;  W1  = a divalent hydrocarbon group; W  = CR1=CR1 or ethynylene;  R1  = H or alkyl;  W2  = H, alkyl, alkylsilyl, alkoxysilyl or an alcohol, ketone, carboxylate ester, amide or acyloxy group;  L1, L2  = ligands of formula (III.1) or (III.2) or together form a ligand of formula (IV):  Z1-Z6  = H, halogen, CN or electron-withdrawing hydrocarbon groups, or two vicinal Z1-Z6 groups can form an electron-withdrawing ring; or Z1+Z2 can form an alkenyl group with at least one electron-withdrawing substituent; or pairs of Z3-Z6 can form an alkenyl group with at least one electron-withdrawing substituent;  Y1, Y2  = CRaRb or SiRcRd;  X  = O, NRe or CRfRg;  R10, R11, R13, R14  = H, alkyl, aryl or alkaryl;  R9, R12, Ra, Rb, Rc, Rd  = H, alkyl, acyl, aryl,alkaryl, cycloalkyl, alkylcycloalkyl, aralkyl or alkaralkyl; or two Rc groups attached to different Si atoms can form a -X-(SiRR'-X)n- chain; or two Rc groups attached to different Si atoms can form a saturated hydrocarbon group forming a 6- to 10-membered ring; or two Ra groups attached to different C atoms can form a saturated hydrocarbon group forming a 6- to 10-membered ring;  n  = 1-3;  R, R'  = groups as defined for Re (not defined);  Rf, Rg  = H, alkyl, acyl, aryl, alkaryl, cycloalkyl, alkylcycloalkyl, aralkyl, alkaralkyl, halogen, alkenyl, alkynyl or SiG1G2G3;  G1-G3  = alkyl; alkoxy; aryl optionally substituted by alkyl or alkoxy; or aralkyl optionally ring-substituted by alkyl or alkoxy;  alternatively, adjacent pairs of T1-T4 can form a hydrocarbon chain; provided that T4 is absent when A is N and T3 is absent when B is N. Independent claims are also included for the following: (1) metal complexes of formula (I) in which T3+T4 can form an aryl ring and/or T1 and T2 -V1-V2 or -W1-W-W2 groups or adjacent pairs of T1-T4 groups can form a hydrocarbon chain; (2) metal complexes of formula (I) in which L1 and L2 are ligands of formula (II), (III.1) or (III.2); (3) a catalytic composition comprising one or more metal complexes as defined in (1) or (2); (4) a process for hydrosilylating olefins or acetylenic derivatives, comprising using the above silicone composition and/or the catalytic composition of (3).