Toughened polystyrene

Claim 1

A METHOD FOR THE MASS POLYMERIZATION OF STYRENE COMPRISING A. HEATING AT A TEMPERATURE FROM 80* TO 150*C. A MIXTURE OF 70 TO 99.75 WEIGHT PERCENT STYRENE AND 0.25 TO 30 WEIGHT PERCENT OF A BENZENE SOLUBLE POLYDIORGANISILOXANE GUM, SAID MIXTURE BEING HEATED AND AGITATED UNTIL FROM 10 TO 40 WEIGHT PERCENT OF THE STYRENE HAS POLYMERIZED PRODUCING A PARTIALLY POLYMERIZED STYRENE MIXTURE HAVING PARTICLES DISPERSED THEREIN CONTAINING THE POLYDIORGANOSILOXANE GUNM, SAID AGITATION BEING AT A SUFFICIENT RATE TO PROVIDE AN AVERAGE PARTICLE SIZE OF FROM 0.5 TO 10 MICRONS, B. CONTUNUING TO HEAT THE PARTIALLY POLYMERIZED STYRENE MIXTURE AT A TEMPERATURE HIGHER THAN IN STEP (A) UNTIL THE STYRENE IS SUBSTANTIALLY POLYMERIZED TO POLYSTYRENE, DURING STEP (B) THE AGITATION RATE BEING REDUCED BELOW THE RATE OF STEP (A), THEREAFTER C. HEATING THE PRODUCT OBTAINED FROM STEP 8B) ABOVE 200*C. FOR AT LEAST 10 MINUTES AND UNTIL THE POLYMERIZED MASS IS SUBSTANTIALLY FREE OF VOLATILE INGREDIENTS BUT AT TEMPERATURES AND TIMES INSUFFICIENT TO DEGRADE THE POLYSTYRENE, AND THEREAFTER A TOUGHENED POLYSTYRENE IS OBTAINED WHICH CONSISTS ESSENTIALLY OF A CONTINUOUS POLYSTYRENE MATRIX HAVING DISPERSED THEREIN GELLED PARTICLES CONSISTING ESSENTIALLY OF POLYSTYRENE GRAFTED TO A POLYDIORGANOSILOXANE GUM WITH INCLUSIONS OF FREE POLYSTYRENE, HAVING A RANGE OF DIAMETERS FROM 0.05 TI 100 MICRONS INCLUSIVE WHERE THE GEOMETRIC MEAN DIAMETER IS FROM 0.5 TO 10 MICRONS AND WHICH HAS A VALUES FOR ROOM TEMPERATURE NOTHCED IZOD IMPACT STRENGTHS IN FOOD POUNDS PER INCH OF NOTCH WHEREIN THE NOTCH IS 45 DEGRESS AND 0.1 INCH DEEP, OF AT LEAST 0.40 FOR COMPRESSION MOLDED AND UNORIENTED SAMPLES, SAID POLYDIORGANOSILIZANE GUM HAVING A WILLIAMS PLASTICITY GREATER THAN 0.020 INCH AND CONSISTING ESSENTIALLY OF FROM 50 TP 99.9 MOL PERCENT DIAMETHYLSILOXANE UNITS, FROM 0 TO 50 MOL PERCENT METHYLPHEMYLSILOXANE UNITS, FROM 0 TO 25 MOL PERCENT DIPHENYLSILOXANE UNITS AND FROM 0.1 TO 30 MOL PERCENT METHYLBINYLSILOXANE UNITS, SAID POLYDIORGANOSILOXANE GUM BEING ENDBLOCKED WITH SILICON-BONDED HYDROXYL RADICALS OR TRIORGANOSILOXY UNITS WHEREIN THE ORGANIC RADICALS ARE SELECTED FROM METHYL, PHENYL AND VINYL.

Claim 2

A METHOD FOR THE MASS POLYMERIZATION OF STYRENE COMPRISING A. HEATING AT A TEMPERATURE FROM 80* TO 150*C. A MIXTURE OF 70 TO 99.75 WEIGHT PERCENT STYRENE AND 0.25 TO 30 WEIGHT PERCENT OF A BENZENE SOLUBLE POLYDIORGANISILOXANE GUM, SAID MIXTURE BEING HEATED AND AGITATED UNTIL FROM 10 TO 40 WEIGHT PERCENT OF THE STYRENE HAS POLYMERIZED PRODUCING A PARTIALLY POLYMERIZED STYRENE MIXTURE HAVING PARTICLES DISPERSED THEREIN CONTAINING THE POLYDIORGANOSILOXANE GUNM, SAID AGITATION BEING AT A SUFFICIENT RATE TO PROVIDE AN AVERAGE PARTICLE SIZE OF FROM 0.5 TO 10 MICRONS, B. CONTUNUING TO HEAT THE PARTIALLY POLYMERIZED STYRENE MIXTURE AT A TEMPERATURE HIGHER THAN IN STEP (A) UNTIL THE STYRENE IS SUBSTANTIALLY POLYMERIZED TO POLYSTYRENE, DURING STEP (B) THE AGITATION RATE BEING REDUCED BELOW THE RATE OF STEP (A), THEREAFTER C. HEATING THE PRODUCT OBTAINED FROM STEP 8B) ABOVE 200*C. FOR AT LEAST 10 MINUTES AND UNTIL THE POLYMERIZED MASS IS SUBSTANTIALLY FREE OF VOLATILE INGREDIENTS BUT AT TEMPERATURES AND TIMES INSUFFICIENT TO DEGRADE THE POLYSTYRENE, AND THEREAFTER A TOUGHENED POLYSTYRENE IS OBTAINED WHICH CONSISTS ESSENTIALLY OF A CONTINUOUS POLYSTYRENE MATRIX HAVING DISPERSED THEREIN GELLED PARTICLES CONSISTING ESSENTIALLY OF POLYSTYRENE GRAFTED TO A POLYDIORGANOSILOXANE GUM WITH INCLUSIONS OF FREE POLYSTYRENE, HAVING A RANGE OF DIAMETERS FROM 0.05 TI 100 MICRONS INCLUSIVE WHERE THE GEOMETRIC MEAN DIAMETER IS FROM 0.5 TO 10 MICRONS AND WHICH HAS A VALUES FOR ROOM TEMPERATURE NOTHCED IZOD IMPACT STRENGTHS IN FOOD POUNDS PER INCH OF NOTCH WHEREIN THE NOTCH IS 45 DEGRESS AND 0.1 INCH DEEP, OF AT LEAST 0.40 FOR COMPRESSION MOLDED AND UNORIENTED SAMPLES, SAID POLYDIORGANOSILIZANE GUM HAVING A WILLIAMS PLASTICITY GREATER THAN 0.020 INCH AND CONSISTING ESSENTIALLY OF FROM 50 TP 99.9 MOL PERCENT DIAMETHYLSILOXANE UNITS, FROM 0 TO 50 MOL PERCENT METHYLPHEMYLSILOXANE UNITS, FROM 0 TO 25 MOL PERCENT DIPHENYLSILOXANE UNITS AND FROM 0.1 TO 30 MOL PERCENT METHYLBINYLSILOXANE UNITS, SAID POLYDIORGANOSILOXANE GUM BEING ENDBLOCKED WITH SILICON-BONDED HYDROXYL RADICALS OR TRIORGANOSILOXY UNITS WHEREIN THE ORGANIC RADICALS ARE SELECTED FROM METHYL, PHENYL AND VINYL.