Color stable chelated titanate compositions

A method of producing a silicone elastomeric composition which is stable under conditions excluding moisture but which will cure upon exposure to moisture comprising mixing under conditions which substantially exclude moisture

• (i) a hydroxyl endblocked polydiorganosiloxane having a viscosity of at least 0.025 Pa.multidot.s at 25.degree. C. having the average formula ##EQU4## in which z has an average value from 1 to 1.01 inclusive,
• y has an average value from 1.99 to 2 inclusive, and the sum of
• y+z is 3,
• R is selected from the group consisting of monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals, and monovalent cyanoalkyl radicals, all of from 1 to 18 inclusive carbon atoms, and n is an integer,
• (ii) at least one silane or silane mixture of the average formula
• R.sub.m Si(OR.sup.1).sub.4-m
• in which
• R is as defined above,
• R.sup.1 is selected from the group consisting of monovalent haloaliphatic hydrocarbon radicals having no halogen alpha to the oxygen and monovalent aliphatic hydrocarbon radicals, both of less than 5 carbon atoms,
• m is from 0 to 3 and has an average value of from 0 to 1.99, and (ii) being present in an amount of at least 1.0 mole of silane per mole of silicon-bonded hydroxyl in (i), and
• (iii) a sufficient amount of a titanium-containing composition, to yield from 0.1 to 10 parts by weight of chelated titanium compound based on 100 parts by weight of (i) and
• placing said silicone elastomerc composition into a moisture impermeable container where said titanium-containing composition comprises the product obtained by mixing, under conditions which substantially exclude moisture,
• (a) a chelated titanium compound having a formula ##STR18## in which R.sup.3 is a monovalent hydrocarbon radical having from 1 to 18 inclusive carbon atoms,
• R.sup.4 is a monovalent radical selected from the group consisting of hydrocarbon radicals having from 1 to 18 carbon atoms, and hydrogen,
• R.sup.5 is a monovalent radical selected from the group consisting of hydrocarbon radicals and aliphatic hydrocarbonoxy radicals each having from 1 to 18 inclusive carbon atoms, and
• Z is a radical selected from the group consisting of monovalent aliphatic hydrocarbonoxy radicals and monovalent acyloxy radicals, each having from 1 to 18 inclusive carbon atoms;
• hydroxyl radical;
• divalent oxygen atoms forming a TiOTi linkage;
• and when taken together form an alkanedioxy radical of the formula ##STR19## in which R.sup.6 is a radical selected from the group consisting of hydrogen atom and monovalent aliphatic hydrocarbon radicals having not more than 8 carbon atoms, the total number of carbon atoms in the alkanedioxy radical is not more than 18, and
• (b) from 1 to 100 parts by weight based on 100 parts by weight of (a), of an additive soluble in the chelated titanium compound and being selected from the group consisting of
• (1) an ester of thioalkanoic acid of the formula ##STR20## wherein R.sup.8 is an alkyl group containing from 1 to 15 inclusive carbon atoms and a is an integer of from 1 to 4 inclusive,
• (2) di-tertiary-butyl phenol containing compounds selected from the group consisting of 2,6-di-tert-butyl-4-methylphenol, tetrakis[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]meth ane, octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, 4,4'-methylenebis(2,6-di-tert-butylphenol), 1,6-hexamethylene-bis-(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), and thiodiethylenebis-(3,5-di-tert-butyl-4-hydroxyhydrocinnamate),
• (3) an organic phosphite selected from the group consisting of the formula
• (R.sup.10 O).sub.b P(OR.sup.11).sub.3-b
• wherein R.sup.10 and R.sup.11 are selected from the group consisting of linear or branched alkyl radicals of from 1 to 18 carbon atoms, and phenyl radical, wherein b is 0 or 1, and the formula ##STR21## wherein R.sup.12 is a linear or branched alkyl radical of from 1 to 18 carbon atoms, and
• (4) a mixture of (2) and (3), the composition having a color of less than 13 as determined by the Gardner Color Scale.

A method of producing a silicone elastomeric composition which is stable under conditions excluding moisture but which will cure upon exposure to moisture comprising mixing under conditions which substantially exclude moisture

• (i) 100 parts by weight of a hydroxyl endblocked polydiorganosiloxane having a viscosity of at least 0.025 Pa.s at 25.degree. C. and having the average formula ##EQU5## in which z has an average value from 1 to 1.01 inclusive,
• y has an average value from 1.99 to 2 inclusive, and the sum of
• y+z is 3,
• R is selected from the group consisting of monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals, and monovalent cyanoalkyl radicals, all of from 1 to 18 inclusive carbon atoms, and n is an integer,
• (ii) at least one silane or silane mixture of the average formula
• R.sub.m Si(OR.sup.1).sub.4-m
• in which
• R is as defined above,
• R.sup.1 is selected from the group consisting of monovalent haloaliphatic hydrocarbon radicals having no halogen alpha to the oxygen and monovalent aliphatic hydrocarbon radicals, both of less than 5 carbon atoms,
• m is from 0 to 3 and has an average value of from 0 to 1.99, and (ii) being present in an amount of at least 1.0 mole of silane per mole of silicon-bonded hydroxyl in (i), and
• (a) at least 0.1 part by weight based on the weight of (i) of a chelated titanium compound having a formula ##STR22## in which R.sup.3 is a monovalent hydrocarbon radical having from 1 to 18 inclusive carbon atoms,
• R.sup.4 is a monovalent radical selected from the group consisting of hydrocarbon radicals having from 1 to 18 carbon atoms, and hydrogen,
• R.sup.5 is a monovalent radical selected from the group consisting of hydrocarbon radicals and aliphatic hydrocarbonoxy radicals each having from 1 to 18 inclusive carbon atoms, and
• Z is a radical selected from the group consisting of monovalent aliphatic hydrocarbonoxy radicals and monovalent acyloxy radicals, each having from 1 to 18 inclusive carbon atoms;
• hydroxyl radical;
• divalent oxygen atoms forming a TiOTi linkage;
• and when taken together form an alkanedioxy radical of the formula ##STR23## in which R.sup.6 is a radical selected from the group consisting of hydrogen atom and monovalent aliphatic hydrocarbn radicals having not more than 8 carbon atoms, the total number of carbon atoms in the alkanedioxy radical is not more than 18, and
• (b) an additive selected from the group consisting of
• (1) at least 0.05 part by weight of an ester of thioalkanoic acid of the formula ##STR24## wherein R.sup.8 is an alkyl group containing from 1 to 15 inclusive carbon atoms and a is an integer of from 1 to 4 inclusive,
• (2) from 0.015 part to 5 parts by weight of di-tertiary-butyl phenol containing compounds selected from the group consisting of 2,6-di-tert-butyl-4-methylphenol, tetrakis[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)-propionate[met hane, octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, 4,4'-methylene-bis(2,6-di-tert-butylphenol), 1,6-hexamethylene-bis-(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), and thiodiethylenebis-(3,5-di-tert-butyl-4-hydroxyhydrocinnamate),
• (3) from 0.001 part to 1 part by weight of an organic phosphite selected from the group consisting of the formula
• (R.sup.10 O).sub.b P(OR.sup.11).sub.3-b
• wherein R.sup.10 and R.sup.11 are selected from the group consisting of linear or branched alkyl radicals of from 1 to 18 carbon atoms, and phenyl radical, wherein b is 0 or 1, and the formula ##STR25## wherein R.sup.12 is a linear or branched alkyl radical of from 1 to 18 carbon atoms;
• and
• (4) a mixture of di-tertiary-butyl phenol of (2) and an organic phosphite of (3), the composition having a color of 5 or less as determined by the Gardner Color Scale.