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. 22, 1987
Filed:
Jun. 16, 1986
Mario Bruzzone, San Donato Milanese, IT;
Silvano Gordini, San Donato Milanese, IT;
Ken Wyllie, Milan, IT;
Enichem Elastomeri S.p.A., , IT;
Abstract
The invention relates to a continuous process for the manufacture of butyl rubber in which the monomers are polymerized using a halogenated polymerization medium in a self-cleaning screw extruder at a constant pressure under boiling plug-flow conditions by means of a modified aluminium halide catalyst which operates at high temperature (relative to prior art very low temperatures of e.g. -100.degree. C.). In contrast to prior art slurry processes, the polymerization mixture forms a sticky, highly viscous mass which is conveyed by screw action to the extruder outlet as polymerization proceeds. The butyl rubber product is separated at a high concentration from vapors of unreacted monomers and polymerization medium which are recycled. Cooling is effected by vaporization of a portion of the mixture of monomers and polymerization medium in a flash tank before supply to the extruder and returning the vaporized fraction and recycle vapors to the flash tank through, in succession, a compressor, heat exchanger and throttle valve. By using the process of the invention, the total energy consumption in butyl rubber manufacture can be cut to about 20% of that of prior art processes.