Abstract: High solids latex suitable for no-gel foam applications is prepared by polymerizing an aliphatic conjugated diolefin, optionally with at least one copolymerizable monomer e.g. styrene, acrylonitrile or vinylidene chloride, in an aqueous emulsion containing less than 6 parts by weight per 100 parts monomers of a polymerization promoting synthetic emulsifier system e.g. sodium alkyl sulfate or ether sulfate and/or sodium sulfosuccinate and from about 0.001 to less than 0.2 parts by weight of a water dispersible agglomerating agent comprising the reaction product of a polyoxyalkylene glycol having a molecular weight of at least 5,000 with the polyepoxide obtained by reacting epichlorohydrin with a polyhydric phenol.The latex is stable and can be compound with fillers and then frothed in the absence of gelling agents to produce a uniform foam.
Abstract: A process for producing a copolymer of styrene and acrylonitrile substantially free of acrylonitrile which comprises copolymerizing styrene and acrylonitrile, and optionally in the presence of an elastomer, and treating the resulting copolymer with an aqueous solution of a sulphur compound selected from the group consisting of alkaline sulfides and alkaline disulfides.
Type:
Grant
Filed:
January 9, 1976
Date of Patent:
March 22, 1977
Assignee:
Labofina S.A.
Inventors:
William J. I. Bracke, Jacqueline Brandli
Abstract: Free flowing polychloroprene powder can be produced from standard latexes by adding 1 - 10% of a salt of an alkyl sulfate, such as sodium lauryl sulfate to an acidified latex and precipitating the rubber in a coagulating solution, separating the particles and drying them. It was also found that the precipitated polychloroprene particles could be made stable in alcohols and ketone (which affords a simpler drying procedure) by adjusting the pH of the mixture of latex and coagulating solution to about 7.25.