g of dodecylbenzenesulfonic acid in 300 g of water the second feed stream is 931 g of octamethylcyclotetrasiloxane the resulting reaction mixture is heated and agitated for an additional 7 hours it is then cooled to room temperature there is added batch wise to the above reaction mixture at room temperature 28 3 g of u03b3 mercaptopropyltrimethoxysilane and the resulting mixture is reheated to 86 u00b0 c and maintained at 86 u00b0 c for 12 hours the reaction mixture is allowed to cool to room temperature and characterized there is obtained a silicone rubber latex having 51 5 by weight solids and a volume average particle size of 700 nm a styrene and acrylonitrile mixture is pumped over a two hour period into a 5 liter glass reactor which contains an agitated mixture at 80 u00b0 c of 1751 g of distilled water and 1693 g of the above silicone rubber latex which has been neutralized to a ph of 6 5 with 4 g sodium bicarbonate dissolved in 50 ml water the styrene and acrylonitrile mixture consists of 573 g of styrene 286 g of acrylonitrile 1 3 g of a 75 sodium dioctylsulfosuccinate in 50 50 ethanol water mixture and 2 6 g t amylperoxyoctoate the resulting reaction mixture is heated at 85 u00b0 c for an additional two hours the mixture is then allowed to cool to room temperature there is obtained a silicone rubber graft copolymer latex the silicone rubber graft copolymer latex has 40 4 total solids by weight and the volume average particle size is.