Title:
POLYPROPYLENE-BASED EXPANDED SHEET SUITABLE FOR THERMOFORMING
Document Type and Number:
Japanese Patent JP2668812
Kind Code:
B2
Abstract:
PURPOSE: To provide polypropylene-based expanded sheet suitable for thermoforming, out of which expanded article excellent in strength, exterior appearance and heat insulating properties is obtained by the full postexpansion at the thermoforming.
CONSTITUTION: The sheet concerned is suitable for thermoforming and characterized by three-layered structure consisting of intermediate layer made of polypropylene-based resin expanded layer and non-expanded film layers, which have the thickness of at least 15μm or more and are laminated on both the sides of the intermediate layer. The expanded layer has the density of 0.1-0.5g/cm and the void content of 40% or less. At the same time, when the sheet is left for three minutes in the atmosphere having the temperature of 190°C, the sheet postexpands at the expansion ratio of 150% or more.
Inventors:
Toshiro Kobayashi
Kajimoto Yoshinori
Kajimoto Yoshinori
Application Number:
JP1631792A
Publication Date:
October 27, 1997
Filing Date:
January 31, 1992
Export Citation:
Assignee:
Sekisui Plastics Co., Ltd.
International Classes:
B29C51/14; B29C44/00; B32B5/18; B32B27/32; B29K23/00; B29K105/04; B29L7/00; B29L9/00; B29L22/00; (IPC1-7): B29C51/14; B32B5/18; B32B27/32
Attorney, Agent or Firm:
Hiroshi Tanaka (1 outside)