PVC- and plasticiser-free foamed sealing and insulating materials - mfd. by spreading dry blend contg. thermoplastic, filler, blowing agent etc. on support melting, smoothing and foaming at elevated temp.

摘要

A process for the prodn. of latex-, PUR-, PVC- and plasticiser-free sealing materials (I) contg. among other things, a foamed layer, comprises spreading the amt. of powder mixt. (II) corresp. to the required foam thickness onto a supporting layer (A) consisting of release paper, cover film or reinforcing web, melting at 70-140 (pref. 70-120) deg.C, smoothing between flat rollers and foaming at 120-200 deg.C. Mixt. (II) contains 100 pts. thermoplastic polymer (III), 0-100 pts. filler, 0.5-7 pts. blowing agent and 0-30 pts. auxiliary substances. Also claimed is mixt. (II) as above, in which (III) has MFI 190/2.16 = 2.5=80, pref. 5-40, and crystallite m.pt. 70-140 (pref. 70-120) deg.C. Also claimed is a mixt. for use as a primer or lining for the foam layer, with the same compsn. as (II) but without blowing agent and activator. Also claimed are sealing and insulating materials (I) obtd. by this process. USE/ADVANTAGE - Used esp. for interior linings in cars. The process enables the prodn. of environmentally more acceptable materials contg. no latex, polyurethane, PVC or plasticiser. With the above powder mixt., it is possible to produce homogeneously distributed layers 2m or even 4-5m wide on commercial powder spreading machines (contrast prior-art mixts.); after passing through the drying oven, this gives homogeneous foam of uniform thickness, without sepn. of components.