Polymeric organometallic photoinitiators and the cationically crosslinkable polyorganosiloxane compostions which comprise them

Polyorganosiloxane compositions which can be crosslinked cationically, photochemically or under an electron beam comprising:

• (a) 100 parts by weight of a polyorganosiloxane containing epoxy functional groups;
• (b) 0.1 to 20 parts by weight of an organometallic photoinitiator compound of formula (I):
• ##STR10## wherein:
• m is an integer or fractional number ranging from 0.5 to 50;
• n is an integer or fractional number ranging from 0 to 500;
• p is an integer or fractional number ranging from 0 to 50;
• the sum m+n is greater than or equal to 2;
• the R.sup.1 symbols are identical or different and each represents a linear or branched alkyl radical having from 1 to 6 carbon atoms or a phenyl radical;
• the A symbol represents an organometallic salt of formula (II):
• (L.sup.1 L.sup.2 M).sup.q+ X.sup.-.sub.q (II)
• in which formula:
• M represents a metal selected from the group consisting of Mn, Cr, Mo, W, Fe, Re and Co;
• L.sup.1 represents one ligand or 2 ligands, which are identical or different, bonded to the metal M by .pi. bonds, which ligand(s) are selected from the group consisting of .eta..sup.3 -allylalkyl, .eta..sup.5 -cyclopentadienyl, .eta..sup.7 -cycloheptatrienyl and .eta..sup.6 -aromatic compounds selected from the group consisting of .eta..sup.6 -benzene ligands and compounds having from 2 to 4 aromatic rings, each ring being capable of contributing 3 to 8 .pi. electrons to the valency layer of the metal M;
• L.sup.2 represents 0 to 3 identical or different ligand(s) bonded to the metal M by .sigma. electrons, and is selected from the group consisting of CO and NO.sub.2 ;
• X.sup.- is a halogenated complex anion selected from the group consisting of BF.sub.4.sup.-, PF.sub.6.sup.-, AsF.sub.6.sup.-, and SbF.sub.6.sup.- and mixtures thereof;
• q is a positive integer equal to 1 or 2;
• the valency bond uniting the monovalent symbol A to Z being carried by a carbon atom of the ligand L.sup.1 or one of the two ligands L.sup.1 ;
• R.sup.2 represents a divalent organic radical selected from the group consisting of:
• (1) linear or branched alkylene radicals having from 2 to 6 carbon atoms;
• (2) radicals of formula:
• --R.sup.3 --O--R.sup.4 -- (III)
• in which the R.sup.3 and R.sup.4 radicals, which are identical or different, represent linear or branched alkylene radicals having from 1 to 6 carbon atoms;
• (3) alkylenecyclohexylene radicals in which the alkylene portion of the radical, which is linear or branched, contains from 2 to 4 carbon atoms and the cyclohexylene portion of the radical, which is connected to the Z group, contains an OH group;
• and
• (4) radicals of formula:
• --R.sup.5 --O--R.sup.6 -- (IV)
• in which the R.sup.5 and R.sup.6 radicals, which are identical or different, represent linear or branched alkylene radicals having from 1 to 6 carbon atoms and the R.sup.6 radical is substituted by one or two OH groups;
• Z is selected from the group consisting of:
• (5)
• --Si(R.sup.7).sub.2 -- (V)
• in which the R.sup.7 radicals are identical or different and each represent a linear or branched alkyl radical having from 1 to 6 carbon atoms when R.sup.2 is represented by (1) or (2);
• and
• (6) the radical --O--CO-- wherein the free bond of the CO is connected to the A residue when R.sup.2 is represented by (3) or (4);
• B is a radical containing an epoxy group;
• with the following provisos:
• (7) when R.sup.2 is represented by (1) or (2) and Z is represented by (5), p is equal to zero;
• (8) when R.sup.2 is represented by (3) or (4) and Z is represented by (6), p is a number equal to zero or a positive number;
• and
• (c) 0 to 50 parts by weight of an additional ingredient selected from the group consisting of adhesion modulators, pigments, photosensitizers, fungicidal agents, bactericidal agents, antimicrobial agents, corrosion inhibitors, inorganic fillers and mixtures thereof.

A process for rendering a surface abherent comprising the steps of:

• (1) applying the following composition to a substrate:
• (a) 100 parts by weight of a polyorganosiloxane containing epoxy functional groups of epoxy;
• (b) 0.1 to 20 parts by weight of an organometallic photoinitiator compound of formula (I):
• ##STR12## wherein:
• m is an integer or fractional number ranging from 0.5 to 50;
• n is an integer or fractional number ranging from 0 to 500;
• p is an integer or fractional number ranging from 0 to 50;
• the sum m+n is greater than or equal to 2;
• the R.sup.1 symbols are identical or different and each represents a linear or branched alkyl radical having from 1 to 6 carbon atoms or a phenyl radical;
• the A symbol represents an organometallic salt of formula (II):
• (L.sup.1 L.sup.2 M).sup.q+ X.sup.-.sub.q (II)
• in which formula:
• M represents a metal selected from the group consisting of Mn, Cr, Mo, W, Fe, Re and Co;
• L.sup.1 represents one ligand or 2 ligands, which are identical or different, bonded to the metal M by .pi. bonds, which ligand(s) are selected from the group consisting of .eta..sup.3 -allylalkyl, .eta..sup.5 -cyclopentadienyl, .eta..sup.7 -cycloheptatrienyl and .eta..sup.6 -aromatic compounds selected from the group consisting of .eta..sup.6 -benzene ligands and compounds having from 2 to 4 aromatic rings, each ring being capable of contributing 3 to 8 .pi. electrons to the valency layer of the metal M;
• L.sup.2 represents 0 to 3 identical or different ligand(s) bonded to the metal M by .sigma. electrons, and is selected from the group consisting of CO and NO.sub.2 ;
• X.sup.- is a halogenated complex anion selected from the group consisting of BF.sub.4.sup.-, PF.sub.6.sup.-, AsF.sub.6.sup.-, and SbF.sub.6.sup.- and mixtures thereof;
• q is a positive integer equal to 1 or 2;
• the valency bond uniting the monovalent symbol A to Z being carried by a carbon atom of the ligand L.sup.1 or one of the two ligands L.sup.1 ;
• R.sup.2 represents a divalent organic radical selected from the group consisting of:
• (1) linear or branched alkylene radicals having from 2 to 6 carbon atoms;
• (2) radicals of formula:
• --R.sup.3 --O--R.sup.4 -- (III)
• in which the R.sup.3 and R.sup.4 radicals, which are identical or different, represent linear or branched alkylene radicals having from 1 to 6 carbon atoms;
• (3) alkylenecyclohexylene radicals in which the alkylene portion of the radical, which is linear or branched, contains from 2 to 4 carbon atoms and the cyclohexylene portion of the radical, which is connected to the Z group, contains an OH group;
• and
• (4) radicals of formula:
• --R.sup.5 --O--R.sup.6 -- (IV)
• in which the R.sup.5 and R.sup.6 radicals, which are identical or different, represent linear or branched alkylene radicals having from 1 to 6 carbon atoms and the R.sup.6 radical is substituted by one or two OH groups;
• Z is selected from the group consisting of:
• (5)
• --Si(R.sup.7).sub.2 -- (V)
• in which the R.sup.7 radicals are identical or different and each represent a linear or branched alkyl radical having from 1 to 6 carbon atoms when R.sup.2 is represented by (1) or (2);
• and
• (6) the radical --O--CO-- wherein the free bond of the CO is connected to the A residue when R.sup.2 is represented by (3) or (4);
• B is a radical containing an epoxy group;
• with the following provisos:
• (7) when R.sup.2 is represented by (1) or (2) and Z is represented by (5), p is equal to zero;
• (8) when R.sup.2 is represented by (3) or (4) and Z is represented by (6), p is a number equal to zero or a positive number;
• and
• (c) 0 to 50 parts by weight of an additional ingredient selected from the group consisting of adhesion modulators, pigments, photosensitizers, fungicidal agents, bactericidal agents, antimicrobial agents, corrosion inhibitors, inorganic fillers and mixtures thereof in an amount of 0.1 to 5 grams of composition per square meter of substrate;
• and
• (2) crosslinking said composition on said substrate photochemically or by using electron beam radiation.

An electronic component encapsulating material, textile coating composition or optical fiber sheathing composition comprising:

• (a) 100 parts by weight of a polyorganosiloxane containing epoxy functional groups of epoxy;
• (b) 0.1 to 20 parts by weight of an organometallic photoinitiator compound of formula (I):
• ##STR13## wherein:
• m is an integer or fractional number ranging from 0.5 to 50;
• n is an integer or fractional number ranging from 0 to 500;
• p is an integer or fractional number ranging from 0 to 50;
• the sum m+n is greater than or equal to 2;
• the R.sup.1 symbols are identical or different and each represents a linear or branched alkyl radical having from 1 to 6 carbon atoms or a phenyl radical;
• the A symbol represents an organometallic salt of formula (II):
• (L.sup.1 L.sup.2 M).sup.q+ X.sup.-.sub.q (II)
• in which formula:
• M represents a metal selected from the group consisting of Mn, Cr, Mo, W, Fe, Re and Co;
• L.sup.1 represents one ligand or 2 ligands, which are identical or different, bonded to the metal M by .pi. bonds, which ligand(s) are selected from the group consisting of .eta..sup.3 -allylalkyl, .eta..sup.5 -cyclopentadienyl, .eta..sup.7 -cycloheptatrienyl and .eta..sup.6 -aromatic compounds selected from the group consisting of .eta..sup.6 -benzene ligands and compounds having from 2 to 4 aromatic rings, each ring being capable of contributing 3 to 8 .pi. electrons to the valency layer of the metal M;
• L.sup.2 represents 0 to 3 identical or different ligand(s) bonded to the metal M by .sigma. electrons, and is selected from the group consisting of CO and NO.sub.2.sup.+ ;
• X.sup.- is a halogenated complex anion selected from the group consisting of BF.sub.4.sup.-, PF.sub.6.sup.-, AsF.sub.6.sup.-, and SbF.sub.6.sup.- and mixtures thereof;
• q is a positive integer equal to 1 or 2;
• the valency bond uniting the monovalent symbol A to Z being carried by a carbon atom of the ligand L.sup.1 or one of the two ligands L.sup.1 ;
• R.sup.2 represents a divalent organic radical selected from the group consisting of:
• (1) linear or branched alkylene radicals having from 2 to 6 carbon atoms;
• (2) radicals of formula:
• --R.sup.3 --O--R.sup.4 -- (III)
• in which the R.sup.3 and R.sup.4 radicals, which are identical or different, represent linear or branched alkylene radicals having from 1 to 6 carbon atoms;
• and
• (3) alkylenecyclohexylene radicals in which the alkylene portion of the radical, which is linear or branched, contains from 2 to 4 carbon atoms and the cyclohexylene portion of the radical, which is connected to the Z group, contains an OH group;
• (4) radicals of formula:
• --R.sup.5 --O--R.sup.6 -- (IV)
• which the R.sup.5 and R.sup.6 radicals, which are identical or different, represent linear or branched alkylene radicals having from 1 to 6 carbon atoms and the R.sup.6 radical is substituted by one or two OH groups;
• Z is selected from the group consisting of:
• (5)
• --Si(R.sup.7).sub.2 -- (V)
• in which the R.sup.7 radicals are identical or different and each represent a linear or branched alkyl radical having from 1 to 6 carbon atoms when R.sup.2 is represented by (1) or (2);
• and
• (6) the radical --O--CO-- wherein the free bond of the CO is connected to the A residue when R.sup.2 is represented by (3) or (4);
• B is a radical containing an epoxy group;
• with the following provisos:
• (7) when R.sup.2 is represented by (1) or (2) and Z is represented by (5), p is equal to zero;
• (8) when R.sup.2 is represented by (3) or (4) and Z is represented by (6), p is a number equal to zero or a positive number;
• and
• (c) 0 to 50 parts by weight of an additional ingredient selected from the group consisting of adhesion modulators, pigments, photosensitizers, fungicidal agents, bactericidal agents, antimicrobial agents, corrosion inhibitors, inorganic fillers and mixtures thereof.