Fluorosilicone polydimethylsiloxane equilibration chainstopper and process for manufacture

Claim 2

A fluorosilicone polydimethylsiloxane equilibration chainstopper composition having an empirical formula as follows: ##STR7## wherein R F is CF 3 CH 2 CH 2 --, X is approximately 10 to approximately 30 and Y is approximately 20 to approximately 50, and having a viscosity of, approximately, 30 to 70 centipoise at 25° C. and a density of, approximately, 1.09 to 1.130.

Claim 3

A composition as in claim 1 having an approximate analytical composition of: ______________________________________ Component Weight % Mole % ______________________________________ CH.sub.2 ═ CHSiO(CH.sub.3).sub.2 2.0-5.0 2.1-5.20 (CH.sub.3).sub.2 SiO 30-40 50.0-64.0 CF.sub.3 CH.sub.2 CH.sub.2 SiO(CH.sub.3) 50-60 34.0-41.0 ______________________________________

Claim 4

A fluorosilicone polydimethylsiloxane equilibration chainstopper composition having a viscosity of, approximately, 30 to 70 centipoise at 25° C., comprising the equilibration product of: (a) octamethylcyclotetrasiloxane, and (b) 3,3,3-trifluoropropylmethylsiloxane cyclic trimer.

Claim 5

A fluorosilicone polydimethylsiloxane equilibration chainstopper composition having a viscosity of, approximately, 30 to 70 centipoise at 25° C., comprising the equilibration product of: (a) octamethylcyclotetrasiloxane, and (b) 3,3,3-trifluoropropylmethylsiloxane cyclic trimer.

Claim 6

A process for producing a fluorosilicone polydimethylsiloxane chainstopper having a viscosity of, approximately, 30 to 70 centipoise at 25° C. comprising the steps of: (A) reacting an admixture of ingredients comprising: (i) 30 to 60 weight percent of 3,3,3-trifluoropropylmethylsiloxane cyclic trimer; (ii) 25 to 65 weight percent of octamethylcyclotetrasiloxane; and (iii) 5 to 15 weight percent of tetramethyldivinyldisiloxane, at a temperature of, approximately, 145° to 155° C. and in the presence of 30 to 55 parts per million alkali metal hydroxide catalyst; and (B) neutralizing the catalyst in the reaction mixture with phosphoric acid, after equilibration has been reached.

Claim 7

A process for producing a fluorosilicone polydimethylsiloxane chainstopper having a viscosity of, approximately, 30 to 70 centipoise at 25° C. comprising the steps of: (A) reacting an admixture of ingredients comprising: (i) 30 to 60 weight percent of 3,3,3-trifluoropropylmethylsiloxane cyclic trimer; (ii) 25 to 65 weight percent of octamethylcyclotetrasiloxane; and (iii) 5 to 15 weight percent of tetramethyldivinyldisiloxane, at a temperature of, approximately, 145° to 155° C. and in the presence of 30 to 55 parts per million alkali metal hydroxide catalyst; and (B) neutralizing the catalyst in the reaction mixture with phosphoric acid, after equilibration has been reached.