Release coating compositions comprising a diorganopolysiloxane and an organosiloxane block copolymer

Claim 1

A RELEASE MATERIAL CONSISTING ESSENTIALLY OF (A) A DIORGANOPOLYSILOXANE OF THE UNIT FORMULA RN(OH)MSIO4-N-M/2 WHEREIN R IS A MONOVALENT RADICAL SELECTED FROM THE GROUP CONSISTING OF ALKYL RADICALS, ALKENYL RADICALS AND ARYL RADICALS, N HAS AN AVERAGE VALUE FROM 1.98 TO 2.0024 INCLUSIVE, AT LEAST 90 PERCENT OF THE SILICON ATOMS HAVING TWO METHYL RADICALS PER SILICON ATOM BONDED TO THE SILICON ATOM THROUGH SILICON-CARBON BONDS, M HAS AN AVERAGE VALUE OF NOT MORE THAN 0.02, THE SUM OF M+N DOES NOT EXCEED 2.0024, SAID DIORGANOPOLYSILOXANE HAVING A VISCOSITY OF AT LEAST 50,000 CS. AT 25%C., THERE BEING NO MORE THAN 2 MOL PERCENT OF THE UNITS WITH ALKENYL RADICALS ATTACHED TO THE SILICON ATOM THROUGH SILICONCARBON BONDS, (B) A BLOCK COPOLYMER CONSISTING ESSENTIALLY OF (1) POLYMER BLOCKS OF THE AVERAGE STRUCTURE ((CH3)2SIO)S(R''2SIO)T(R''SIO1.5)U, WHEREIN R'' IS A MONOVALENT RADICAL SELECTED FROM THE GROUP CONSISTING OF METHYL, ETHYL, VINYL AND PHENYL RADICALS, THE SUM OF S+T+U HAS AN AVERAGE VALUE FROM 6 TO 100 INCLUSIVE AND T AND U EACH HAVE A VALUE OF UP TO 10 PERCENT OF THE SUM OF S+T+U, (2) POLYMER BLOCKS OF THE AVERAGE UNIT FORMULA (C6H5)CH3)WSIO4-W-Q/2, WHEREIN Q HAS AN AVERAGE VALUE FROM 1 TO 1.25 INCLUSIVE, W HAS AN AVERAGE VALUE OF UP TO 0.25 INCLUSIVE AND THE SUM OF Q+W DOES NOT EXCEED 1.25, THE SILOXANE UNITS IN (1) BEING FROM 10 TO 75 MOL PERCENT AND THE SILOXANE UNITS (2) BEING FROM 25 TO 90 MOL PERCENT OF THE TOTAL SILOXANE UNITS IN SAID BLOCK COPOLYMER, THE MINIMUM MOL PERCENT OF SILOXANE UNITS (2) WHEN THE SUM OF S+T+U HAS AN AVERAGE VALUE OF FROM 50 TO 100 BEING DETERMINED BY THE EQUATION 50M/S+0.1S=30, WHERE M IS THE MINIMUM MOL PERCENT OF SILOXANE UNITS (2) AND S IS THE SUM OF S+T+U, THERE BEING PRESENT 15 TO 95 INCLUSIVE WEIGHT PERCENT OF (A) AND 5 TO 85 INCLUSIVE WEIGHT PERCENT OF (B), EACH BASED ON THE COMBINED WEIGHT OF (A)+(B).