| 摘要 |
510,215. Synthetic resin compositions. WHEATLEY, R., and VICTORIA RUBBER CO., Ltd. April 8, 1938, No. 10753. [Class 2 (iii)] [Also in Groups VIII and XVI] A printers' blanket having a backing of woven wool or cotton or woven cotton and felted wool is provided with a working surface of a resilient oil-resisting composition containing gritty particles. Suitable compositions may comprise (1) rubber, (2) reaction products of dihalogenated aliphatic compounds with metallic polysulphides, (3) chloroprene polymers, (4) inter-polymers of butadiene and acrylic acid-nitrile, or mixtures of (2) and (4). Resins such as colophony and glycerol-phthalic acid condensation products may be added. Suitable gritty materials are crushed emery, glass, flint; quartz and silicon carbide of a few thousandths of an inch in diameter. The example describes the preparation of a mixture of (2) and (4) above, rubber, china clay, zinc oxide, rosin oil, colophony, sulphur, mercaptobenzo-thiazole, triphenylphosphate, carbon black and silicon carbide with benzol,.which is spread or calendered on to the base and vulcanized. Alternatively an aqueous dispersion may be used. The base may be coated with two or more coats of a similar mixture not containing gritty particles. |
