High impact vinyl chloride resin formulations of improved clarity andmethod of making same

Abstract

Abstract A METHOD OF MAKING HIGH IMPACT VINYL CHLORIDE RESIN FORMULATIONS COMPRISING TWO CONSECUTIVE STAGES OF OVERPOLYMERIZATION, THE FIRST OF WHICH IS AN OVER-POLYMERIZATION IN AQUEOUS DISPERSION WHICH DEPOSITE A TOUGH, RUBBERY, ESSENTIALLY COMPLETELY-GELLED POLYACRYLATE ON SEED RESIN PARTICLES OF INSOLUBLE OR CROSSLINKED STYRENE COPOLYMER AND , IN THE SECOND STAGE, OVER-POLYMERIZATION, THE RUBBER-COATED FIRST-STAGE STYRENE COPOLYMER SEED PARTICLES ARE ENCASED IN A MATRIX OF HARD VINYL CHLORIDE RESIN. THE PARTICLE SIZE OF THE STYRENE COPOLYMER SEED RESIN LATEX PARTICLWS IS CRITICAL, HIGH IMPACT PRODUCTS BEING OBTAINED ONLY WITH SEED PARTICLES AVERAGING ABOUT 200 TO ABOUT 1700 A., MORE PREFERABLY BETWEEN ABOUT 350 A. AND ABOUT 1300 A. THE THICHNESS OF THE RUBBERY COATING ON THE SEED LATEX PARTICLES RESULTING FROM THE FIRST STAGE OVER-POLYMERIZATION LIKEWISE IS CRITICAL, HIGH IMPACT PRODUCTS BEING OBTAINED WHEN SUCH COATING IS FROM ABOUT 25 TO ABOUT 500 A. IN THICKNESS. A MOST PREFERRED MODIFICATION WHICH IS NOT ONLY ESSENTIALLY CLEAR AND ESSENTIALLY FREE OF HAZE BUT ALSO DEVELOPS HIGH IMPACT RESISTANCE IS PRODUCED WHEN SEED PARTICLES OF CROSS-LINKED STYRENE COPOLYMER AVERAGING FROM ABOUT 200 TO ABOUT 800 A. IN DIAMETER ARE GIVEN A GRAFTED COATING OR SHELL OF GELLED ACRYLATE FROM ABOUT 25 A. TO ABOUT 90 A. IN THICKNESS AND THE RESULTING PRODUCT THEN OVER-POLYMERIZED WITH A HARD VINYL CHLORDE RESIN. BOTH GRAFTING AND A CRITICALLY-THIN ACRLATE SHELL ARE NECESSARY TO PRODUCE THE CLEAR VERSION OF THE PRODUCTS OF THIS INVENTION. GRAFTING IS OBTAINED MOST EASILY BY CROSSLINKING THE STYRENE COPOLYMER SEED RESIN PARTICLES WITH A MONOMER SUCH AS ALLYL METHACRYLATE CONTAINING AT LEAST TWO POLYMERIZABLE GROUPINGS OF MARKEDLY FIEEERING POLYMERIZATION REACTIVITY WITH STYRENE MONOMER SUCH AS TO LEAVE AT LEAST A FEW OF POLYMERIZABLE REACTIVE SITES ON THE SURFACE OF THE SEED PARTICLES.

Inventors

• 👤 P Kelley

Bibliographic Details