Silicone membranes formed without the use of 1-1-1 trichloroethane

A solvent mixture to disperse or dissolve a copolymer comprising a first moiety of methyl-trifluoropropyl siloxane and a second moiety of dimethylsiloxane in the ratio of about 10 mole % to 40 mole % of said first moiety to about 60 mole % to about 90% of said second moiety, said solvent mixture comprising perchlorethylene and an additive of one or more of the members of one or more of the following:

• an acid ester selected from the group consisting of ethylacetate, propylacetate, and butylacetate, and a ketone selected from the group consisting of acetone, methyl ethyl ketone, methyl propyl ketone, methylisobutylketone, methylbutylketone;
• said solvent mixture comprising between about 70% to about 97% by weight of perchlorethylene and about 30% to about 3% of said additive.