| 摘要 |
1377445 Surface modification of polymer mouldings LION FAT & OIL CO Ltd 18 Feb 1972 [20 Feb 1971] 7757/72 Heading B2E [Also in Division C3] A moulding made from a thermoplastic resin incorporating a water- or acid-soluble filler is provided with a protective surface layer by treating the surface with an acid to remove the superficial filler, then applying a heat treatment to form a continuous layer which is free from the filler. The heat treatment may involve only heating at 120-200‹C., or a flame treatment, or pressure may be applied simultaneously, e.g. by means of a heating roller. Exemplified resins are polyethylene, polypropylene and poly (methyl methacrylate) in the form of moulded boards filled with calcium sulphite, calcium carbonate or calcium carbonate and gypsum. Hydrochloric or acetic acid is used to remove the superficial filler in the examples. |
