Patent · US Expired

Process for preparing concentrated acrylonitrile polymer solutions

US4028302A · kind A · utility

5Cited by
2References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 7, 1975
Grant dateJun 7, 1977
Priority date
Expiry dateOct 7, 1995

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08J2333/20
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.