| 摘要 |
A mixture of unexpanded thermoplastic microspheres and filler is made. It is stirred while heating and the microspheres expand. Pref. some of the heat is provided by friction. - Pref. the weight ratio of spheres to filler is between 1:100 and 50:100. The spheres are a copolymer of 65-90 weight % vinyldene chloride and 35-10% acrylontrile. The filler is pref. an inorganic e.g. talc. (Provisional Basic previously advised in week 8923) |
