Patent ID: 7311945
Filing Date: 2007-12-25
Classification: C08J,C08K,C09D,Y10S,Y10T

Abstract:
1. A varnish support having antifriction properties, said support comprising a substrate coated on at least one of its surfaces with at least one layer of silicone elastomer which is crosslinked or which is at least partially crosslinked, said layer of silicone elastomer coated with an antifriction varnish obtained from a silicone composition comprising at least one polyorganosiloxane (POS) which is crosslinked by means of crosslinking functional groups (CFG) by the cationic and/or free-radical route and an effective quantity of a cationic initiator system comprising, as thermal initiator and/or photoinitiator, a product chosen from the onium salts of an element of groups 15 to 17 of the Periodic Table or the salts of an organometallic complex of an element of groups 4 to 10 of the Periodic Table, whose cationic entity is selected from: 1) the onium salts of formula (I): in which formula: A represents an element of groups 15 to 17 of the Periodic Table; R R n is an integer ranging from 1 to v+1, v being the valency of the element A; m is an integer ranging from 0 to v 1 with n+m =v+1; 2) oxoisothiochromanium salts; 3) sulfonium salts in which the cationic entity comprises: 3-1) at least one polysulfonium species of formula (III.1): in which: the symbols Ar the symbols Ar the symbols Ar t is an integer equal to 0 or 1, with the additional conditions according to which: a) when t=0, the symbol Y is then a monovalent radical Y where the symbols Ar 1 and Ar 2 have the meanings given above, b) when t=1: b2) on the other hand, only in the case where the symbol Y represents Y 3 or Y 4 , the radicals Ar 1 and Ar 2 (terminal) possess, in addition to the meanings given above, the possibility of being linked to each other by the residue Y′ consisting of Y′ 1 a single valency bond or of Y′ 2 a divalent residue chosen from the residues cited in the definition of Y 4 , which is seated between the carbon atoms, facing one another, situated on each aromatic ring at the ortho position with respect to the carbon atom directly linked to the cation S + ; 3-2) and/or at least one mono-sulfonium species possessing a single cationic center S + per mol of cation and consisting of species of formula (III.2): in which Ar 1 and Ar 2 have the meanings given above in formula (III.1), including the possibility of directly linking to one another only one of the radicals Ar 1 to Ar 2 in the manner indicated above in the definition of the additional condition which applies when t=1 in formula (III.1), involving the residue Y′; 4) the organometallic salts of formula (IV): in which formula: M represents a metal of group 4 to 10 of the Periodic Table; L L L the anionic entity having the formula: [X a and b are integers ranging, for a, from 0 to 6 and, for b, from 0 to 6 with a+b≧2; the symbols X the symbols X a halogen atom with a=0 to 3, an OH functional group with a=0 to 2; the symbols R are identical or different and represent: a phenyl radical substituted with at least one electron-attracting group, and/or with at least 2 halogen atoms, and this being when the cationic entity is an onium of an element of groups 15 to 17 of the Periodic Table, a phenyl radical substituted with at least one electron-attracting atom or one electron-attracting group, and this being when the cationic entity is an organo-metallic complex of an element of groups 4 to 10 of the Periodic Table, an aryl radical containing at least two aromatic nuclei, optionally substituted with at least one element or one electron-attracting group, regardless of the cationic entity; wherein said POS carrying CFG are epoxysilicones and/or vinyl ether silicones which are: 1) either linear and consist of units of formula (II-1), ending with units of formula (II-2), 2) or cyclic and consisting of units of formula (II-1): in which formulae: the symbols R the symbols Z are similar or different and represent either the radical R at least one of the symbols Z corresponding to a CFG group, said composition comprising, in addition, a silane substituted with CFG and hydrolyzable secondary functional groups (SFG) and having the formula