Patent ID: 8153724

Claim:
A moisture curable composition capable of cure to an elastomeric body comprising (a) an extended polymer comprising (i) an organosiloxane containing polymer of the formula X 2 -A-X 1 where X 2 and X 1 are independently selected from silyl groups containing hydroxyl or hydrolysable groups selected from —Si(OH) 3 , —(R a )Si(OH) 2 , —(R a ) 2 SiOH, —R a Si(OR b ) 2 , —Si(OR b ) 3 , —R a 2 SiOR b and —R a 2 Si—R c —SiR d p (OR b ) 3−p where each R a independently represents a monovalent hydrocarbyl group, each R b and R d group is independently an alkyl or alkoxy group in which the alkyl groups suitably have up to 6 carbon atoms; R c is a divalent hydrocarbon group which may be interrupted by one or more siloxane spacers having up to 6 silicon atoms; and p has the value 0, 1 or 2; and A is an organopolysiloxane containing molecular chain; and (ii) an organic extender selected from linear or branched mono unsaturated hydrocarbons, (b) a suitable cross-linking agent which has at least two hydroxyl and/or hydrolysable groups reactive with the organopolysiloxane polymer, (c) a suitable condensation catalyst, (d) an organic plasticiser selected from one or more of the group of natural drying oils, fatty acid(s), fatty acid esters, polyols, and organic phosphates, and optionally (e) one or more fillers wherein the organopolysiloxane polymer comprises from 5 to 20% by weight of the composition.