| 摘要 |
1296095 Thermosetting moulding compositions containing carboxyl-containing rubber BRITISH INDUSTRIAL PLASTICS Ltd 24 Feb 1970 [25 Feb 1969] 8817/70 Headings C3P and C3R A moulding composition comprises a thermosetting resin, particles of diameter not exceeding 50 Á of a rubber containing free carboxyl groups, and a cross-linking agent for the rubber, the weight of rubber being 5-35% of the weight of the resin. Suitable rubbers include acrylic or methacrylic acid-modified styrene-butadiene copolymers. Suitable resins include aminoplast and phenoplast resins. Suitable cross-linking agents include ZnO, MgO, NaAlO 2 and ethylenediamine. Suitable fillers which may be present include alpha-cellulose, wood flour and kaolin. In examples urea-formaldehyde, melamineformaldehyde or phenol-formaldehyde syrup is mixed with a 50% latex of rubber particles containing rubber molecules having carboxyl groups and then with alpha-cellulose or wood flour, zinc stearate or stearic acid and, in the former cases, zinc oxide and sulphur. |
