The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 28, 1993
Filed:
Nov. 25, 1991
Joseph M Kelley, Westfield, NJ (US);
Other;
Abstract
An improved process for the polymerization of styrene is provided. The process comprises feeding styrene monomer and a mixture of peroxides, which decompose at progressively higher temperatures, into a prepolymerization vessel maintained at 200.degree.-270.degree. F. About 20-40% of the styrene in this vessel is converted to polymer (depending on temperature and residence time) and then fed to an extruder where the polymer is raised in temperature by passage through a heat exchanger or through the heated throat of the extruder. During this heating, the polymerization is completed in seconds to minutes in an extruder as the peroxides decompose in sequence as the temperature rises. A final devolatilization zone is provided to remove the final traces of monomer. The molten polymer is then passed through a die and stranded or hot die face cut. In like manner, this process can be used to produce styrene-acrylonitrile copolymers by the addition, prior to prepolymerization, of acrylonitrile to the prepolymerization vessel, impact polystyrene by the addition of rubber to the styrene in a dissolver and ABS by the addition of rubber and acrylonitrile to the styrene in a dissolver prior to prepolymerization.