Title:
METHOD FOR EXTRUSION FOAMING OF POLYOLEFINIC RESIN
Document Type and Number:
Japanese Patent JPH0517612
Kind Code:
A
Abstract:
PURPOSE:To obtain a molded foam which is less apt to cause ozone layer destruction and suffers little dimensional change with time by using a mixture of three specific compounds as volatile foaming agent in the extrusion foaming of a polyolefinic resin. CONSTITUTION:A volatile foaming agent is added in an adequate amount to a polyolefinic resin (e.g. polyethylene) which has been heat-melted in an extruder and is moving therethrough. The foaming agent is a three-component mixture consisting of 5-65wt.% 1-chloro-1,1-difluoroethane, 5-90wt.% monochlorodifluoromethane, and 5-35wt.% 1,1,1,2-tetrafluoroethane. The resulting melt is extruded and foamed into a predetermined shape at ordinary pressure to obtain a polyolefinic resin foam. The foam thus obtained is extremely less apt to cause ozone layer destruction, has a high expansion ratio, and suffers little shrinkage after foam molding.
Inventors:
SHIMOYAMA KOJI
NAKADA AKINORI
NAKADA AKINORI
Application Number:
JP17234091A
Publication Date:
January 26, 1993
Filing Date:
July 12, 1991
Export Citation:
Assignee:
HITACHI CHEMICAL CO LTD
International Classes:
B29C47/00; C08J9/14; C08L23/00; B29K105/04; (IPC1-7): B29C47/00; B29K105/04; C08J9/14; C08L23/00
Domestic Patent References:
| JPH0364335A | 1991-03-19 | |||
| JPH02279739A | 1990-11-15 |
Attorney, Agent or Firm:
Kunihiko Wakabayashi