Abstract: The present fluorosilicone composition is an addition reaction curable composition that uses, as an alkenyl group-containing organopolysiloxane, a fluorine-containing organopolysiloxane represented by the following general formula (1): ##STR1## wherein R represents a vinyl group, R.sup.1 represents an alkyl group or a phenyl group, R.sup.2 represents a group represented by the following formula (2): ##STR2## in which p is an integer of 2 to 8 and q is an integer of 1 to 10, and n and m are each a positive integer. This composition can form a gellike cured product particularly excellent in acid resistance.

Abstract: A method of producing a silicone polymer-filler mixture in powder form has been developed. The method combines an oligomer consisting of a polydiorganosiloxane, sufficient acidic or neutral reinforcing filler to yield a powder, and a catalytic amount of a catalyst consisting of (a) sulfuric acid or a sulfonic acid of the formula XSO.sub.3 H wherein X is selected from the group consisting of halogen, alkyl, aryl, alkoxy and alkaryl radicals, (b) perfluorinated alkane sulfonic acid, and (c) a combination of quaternary ammonium carboxylate and carboxylic acid, to give a powdery mixture. The powdery mixture is polymerized, then the catalyst is inactivated while maintaining a powdery state. The method requires a minimum of energy for mixing.