| 摘要 |
<p>A hard synthetic material with fireproof and non-smoking properties is prepd. by mixing a chemically or heat-hardening synthetic, in the unhardened or partially hardened state, with a filler which is mainly borax and boric acid (or salts). The filler is easily compatible with hard synthetics. Relatively large amts. of the filler can be incorporated, without affecting the mechanical properties, esp. of polyesters. The filler is cheaper than the synthetic. The ratio by wt. of synthetic:filler is 100:50-150 (1:1) and the ratio by wt. of borax: boric acid is pref. 1:1. A small amt. of other fillers, e.g. sand or cement, may be included. The claimed synthetics are polyesters, polyurethanes and epoxy, urea or phenol resins.</p> |
