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. 07, 1977
Filed:
Oct. 07, 1975
Daniel Gregory Tynan, Wilmington, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
Clear, bubble-free acrylonitrile polymer solutions of high polymer concentration are rapidly prepared by feeding powdered acrylonitrile polymer to a cool zone of a twin-screw machine and injecting solvent to form a slurry at a temperature below 40.degree. C., advancing the cool slurry to a heated zone and converting the slurry into a concentrated solution at 110.degree. to 150.degree. C. while intermittently squeezing it in directions transverse to the axes of the screws, and discharging the hot solution continuously from the machine. A zone of reduced pressure is provided to remove gases trapped in the slurry. A twin-screw machine for carrying out the process is disclosed.