Process to prepare 2-phenylpropyl containing polydiorganosiloxanes

Claim 1

A method of preparing hydroxyl endblocked copolymers with methyl(2-phenylpropyl)disiloxanediol and dialkylcyclosiloxane consisting essentially of (A) adding to a reaction vessel containing distilled water and water miscible solvent in a ratio of from about 1:2 to 2:1, methyl(2-phenylpropyl)dichlorosilane, at a slow rate with stirring so that the temperature is maintained between 20° C. and 45° C., and the maxiumum HCl concentration is 5 Normal, then (B) cooling to below 35° C. and separating the reaction product from the acidified water, then (C) dissolving the reaction product in solvent, then (D) washing with saturated sodium bicarbonate solution, followed by distilled water to give a pH of about 7, then (E) removing solvent to give a product of primarily methyl(2-phenylpropyl)disiloxanediol, then (F) mixing with sufficient dialkylcyclosiloxane to give the desired mol ratio of radicals and heating, then (G) adding powdered potassium hydroxide and heating to equilibrate, then (H) removing the water from the composition by use of a water trap and heating to reflux, then (I) cooling rapidly to about 65° C. and neutralizing with CO 2 , then (J) filtering and stripping under vacuum to yield a copolymer having the formula ##STR2## where Ph is phenyl, R is methyl, ethyl, propyl, trifluoropropyl, a is from 3 to 500 and b is from 2 to 500 with a being at least equal to b.

Claim 2

A method of preparing hydroxyl endblocked copolymers with methyl(2-phenylpropyl)disiloxanediol and dialkylcyclosiloxane consisting essentially of (A) adding to a reaction vessel containing distilled water and water miscible solvent in a ratio of from about 1:2 to 2:1, methyl(2-phenylpropyl)dichlorosilane, at a slow rate with stirring so that the temperature is maintained between 20° C. and 45° C., and the maxiumum HCl concentration is 5 Normal, then (B) cooling to below 35° C. and separating the reaction product from the acidified water, then (C) dissolving the reaction product in solvent, then (D) washing with saturated sodium bicarbonate solution, followed by distilled water to give a pH of about 7, then (E) removing solvent to give a product of primarily methyl(2-phenylpropyl)disiloxanediol, then (F) mixing with sufficient dialkylcyclosiloxane to give the desired mol ratio of radicals and heating, then (G) adding powdered potassium hydroxide and heating to equilibrate, then (H) removing the water from the composition by use of a water trap and heating to reflux, then (I) cooling rapidly to about 65° C. and neutralizing with CO 2 , then (J) filtering and stripping under vacuum to yield a copolymer having the formula ##STR2## where Ph is phenyl, R is methyl, ethyl, propyl, trifluoropropyl, a is from 3 to 500 and b is from 2 to 500 with a being at least equal to b.