公开(公告)号：DE1934232A1

公开(公告)日：1971-02-11

申请号：DE1934232

申请日：1969-07-05

Applicant: TORAY INDUSTRIES

Inventor： OKADA HIROSHI ,  OKSAKADA ATSUSHI ,  MINAMI SATOYUKI ,  AOKI TOSHIKAZU ,  OTSUKA HIROMI ,  KOYANAGI HIRONOBU ,  OTSU SHIGA ,  HISAMORI TETSUO

IPC: B32B27/00 ,  C08J9/06 ,  C08J9/34 ,  B29D27/00

Abstract: 1,210,637. Foam laminates. TORAY INDUSTRIES Inc. 21 June, 1969, No. 31460/69. Heading B5N. [Also in Division C3] Foams are made by laminating thermoplastic resin films to both surfaces of a thermoplastic resin sheet containing a foaming agent, whose decomposition temperature is above the softening temperature of the resin(s), cross-linking the films before, during, or after lamination, and heating to cause foaming. The central sheet may contain 0À1-60 wt. per cent of foaming agent. Foaming agents may be included in the outer films. The resins can be cross-linked before and/or after lamination by including 0À1-5 wt. per cent of cross-linking agent and/or by irradiating to 2-40 Mrad. dosage; crosslinking accelerators may be included. A single heating operation, e.g. by hot air, radiant heat or a molten salt or alloy bath, may serve both for cross-linking and foaming. Lists of foaming, cross-linking and accelerating agents are given; other additives present may be weathering agents, extenders, plasticizers, pigments, flameretardants, antistatic agents and ultraviolet absorbers. Films and sheets may be formed by extrusion, calendering or rolling a mixture of resin and additives; and may be laminated by heat and pressure or by extrusion. The foamable central sheet may be a multi-layer construction including non-foamable sheets. The outer films may be 1-1000 microns thick after the foaming operation and the central layer may be at least 300 microns thick before foaming. Specified thermoplastic resins are polyethylene, polypropylene, polybutene, poly- 4-methylpentene-1 and copolymers of olefins with vinyl acetate, vinyl chloride and alkyl acrylates and methacrylates; and polyvinyl chloride.