Cationic cross-linkable polyorganosiloxane compositions, their use as anti-adherents for paper and for protecting optical fibers and integrated circuits.

摘要

Compositions based on a silicone crosslinkable by a cationic route and on a catalytic quantity of an organometallic complex borate, a borate in which the cationic entity is an organometallic salt of formula (L<1>L<2>L<3>M)<+q> where - M denotes a metal of group 4 to 10 of the Periodic Classification (Chem.&Eng.News, vol 63, No.5, 26 of 4 February 1985) - L<1> denotes 1 ligand bonded to the metal M by pi electrons, a ligand chosen from eta <3>-alkyl, eta <5>-cyclopentadienyl and eta <7>-cycloheptatrienyl ligands and eta <6>-aromatic compounds; - L<2> denotes 1 ligand bonded to the metal M by pi electrons, a ligand chosen from eta <7>-cycloheptatrienyl ligands and eta <6>-aromatic compounds; - L<3> denotes from 0 to 3 identical or different ligands bonded to the metal M by sigma electrons, ligand(s) chosen from CO and NO2<+>; the total electron charge q of the complex being equal to +1 or +2; and in which the borate anionic entity has the formula [BXaRb]<-> where a and b are integers ranging from 0 to 4 with a + b = 4 the symbols X denote: - 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 denote a radical which is - phenyl substituted by at least one element or an electron-withdrawing group - aryl containing at least two aromatic nuclei and optionally substituted by at least one element or an electron-withdrawing group. These compositions can be employed as a thin layer for the production of release coatings or as a thick layer for sheathing optical fibres or protecting printed circuits in electronics.