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:
Jun. 13, 1978
Filed:
Jan. 19, 1976
Setsuo Nakai, Niihama, JA;
Hiroshi Ochi, Niihama, JA;
Sumitomo Chemical Company, Limited, Osaka, JA;
The Japan Steel Works, Ltd., Tokyo, JA;
Abstract
A method for removing unreacted monomer (or monomers) from an ethylene homopolymer or a copolymer of ethylene and at least one monomer copolymerizable with ethylene during the course of pelletization by use of an extruder, said polymer having been formed by high-pressure polymerization by use of a radiation or a radical initiator, discharged from the reactor by way of a separator, and fed to said extruder to be pelletized, which method comprises injecting into said extruder 0.1 to 10% by weight (based on said polymer) of water or steam intermixing the polymer and the water or steam in the mixing section of the extruder screw, and subjecting the resulting mix to a subatmospheric pressure of 500 mmHg (absolute) or less in the venting zone provided in the extruder. This method permits efficient removal of the unreacted ethylene or the unreacted ethylene and comonomer contained in a homopolymer or copolymer of ethylene.