Patent ID: 6455641
Filing Date: 2002-09-24
Classification: C08G

Abstract:
A process for the preparation polyorganosiloxanes with ester functions of the formula (I):R1R2R3SiO(R4R5SiO)p(R6QSiO)qSiR3R2R1â€ƒâ€ƒ(I), wherein:the symbols R1, R2 are identical or different and represent: a C1 to C6 alkyl radical or a phenyl radical; or a â€”OR7 radical, wherein R7 represents a linear or branched C1 to C6 alkyl radical; the symbols R4, R5 and R6 are identical or different and represent a C1 to C6 alkyl radical or a phenyl radical; the symbols R3, which may be identical or different, represent: a linear or branched C1 to C6 alkyl radical or a phenyl radical; the symbol Q; or a â€”OR7 group, wherein R7 represents a linear or branched C1 to C6 alkyl radical; the symbols Q, which are identical or different, represent an ester function or an alcohol function, respectively with formulae (1) and (2) below: â€”Râ€²OC(O)Râ€³â€ƒâ€ƒ(1) â€”Râ€²OHâ€ƒâ€ƒ(2) wherein:Râ€² represents a linear or branched C3-C20 alkylene group; and Râ€³ represents a methyl group; at least one of symbols Q representing an ester function with formula (1);p represents an average number of 0 or more; q represents an average number of 0 or more, at least one of symbols R3 representing the ester symbol Q of formula (1) when q equals 0; said process comprising the steps of: a) carrying out a hydrosilylation reaction between a hydrogeno-polyorganosiloxane with formula (II): R1R2R3â€²SiO(R4R5SiO)p(R6HSiO)qSiR3â€²R2R1â€ƒâ€ƒ(II) wherein:the symbols R1, R2, R4, R5, R6, p and q have the definitions given above; the symbols R3â€², which may be identical or different, represent: a linear or branched C1 to C6 alkyl radical or a phenyl radical; H; or a â€”OR7 group, wherein R7 represents a linear or branched C1 to C6 alkyl radical; and an &agr;-olefinic alcohol with formula ROH, wherein R represents an &agr;-olefinic radical from which the divalent radical Râ€² derives by opening of the a double bond and adding hydrogen; and, then, b) carrying out an esterification reaction of the hydroxy-alkylated polyorganosiloxane with formula (II1) obtained in step a): R1R2R3â€³SiO (R4R5SiO)p(R6Qâ€²SiO)qSiR3â€³R2R1â€ƒâ€ƒ(III) wherein:the symbols R1, R2, R4, R5, R6, p and q have the definitions given above; the symbols R3â€³, which may be identical or different, represent: a linear or branched C1 to C6 alkyl radical or a phenyl radical; the symbol Qâ€²; or a â€”OR7 group, wherein R7 has the definition given above; the symbol Qâ€² represents the radical Râ€²OH, wherein Râ€² has the definition given above; with an acyl halide with formula XC(O)Râ€³, wherein X represents a halogen atom and Râ€³ has the definition given above, and in the absence of an esterification catalyst; and c) recovering said polyorganosiloxanes with an ester function by eliminating the &agr; olefinic by-products and the hydrohalic acid formed.