Patent · US Expired

Apparatus and method for producing resin

US6562936B1 · kind B1 · utility

5Cited by
7References
29Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 11, 2001
Grant dateMay 13, 2003
Priority date
Expiry dateJun 11, 2021

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C48/03
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A method of producing a polycarbonate or the like which is excellent in hydrolysis and heat stability such as a reduction in molecular weight at the time of molding and color retention and moldability such as releasability and transferability, rarely experiences residence deterioration such as coloring, crosslinking and gel formation and has an extremely small content of foreign matter by employing a special structure for an opening in the side surface of a horizontal cylindrical vacuum resin treating apparatus, supplying a molten polycarbonate into a unidirectional rotary intermeshing double-screw extruder under specific conditions, adding a specific agent under specific conditions and cleaning the inner surface of a production apparatus by a specific method.

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