Process for the preparation of pure-white polystyrene compositions
Abstract
Abstract PURE-WHITE POLYSTYRENE COMPOSITIONS HAVING HIGH IMPACT RESISTANCE ANC GOOD HEAT RESISTANCE ARE PREPARED BY A TWO STEP GRAFT POLYMERIZATION, THAT IS, BY CONDUCTING A BULK POLYMERIZATION OF A MIXTURE OF A STYRENE MONOMER AND POLYBUTADIENE AT 80-120*C., WITH THE CONVERSION RATIO OF 20-40% OF THE STYRENE MONOMER WITH THE ADDITION OF, IF NECESSARY, LESS THAN 0.2% BY WEIGHT OF DICUMYL PEROXIDE, CONDUCTING A SUSPENSION POLYMERIZATION OF THE PRODUCT, AFTER MIXING THE PRODUCT WITH AN AQUEOUS SOLUTION OF A DISPERSING AGENT, AT 105-125*C., WITH THE ADDITION OF DICUMYL PEROXIDE, IN AN AMOUNT SUCH THAT THE TOTAL AMOUNT OF THE CATALYST IS 0.05-0.5% BY WEIGHT UNTIL THE CONVERSION RATIO REACHES MORE THAN 70%, AND THEN CONDUCTING FURTHER POLYMERIZATION AT 125-140*C. THE UNIFORMITY OF THE PRODUCT BEADS CAN BE FURTHER IMPROVED BY USING AS THE DISPERSING AGENT A PARTIALLY SAPONIFIED VINYL ACETATE-DODECYLVINYL ETHER COPOLYMER.
Inventors
- 👤 Eichi Moriguchi
- 👤 Takeshi Goto
- 👤 Michikazu Hiraoka
- 👤 Teruhisa Mitsumori
- 👤 Shonosuke Rokudo
Bibliographic Details
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