| 摘要 |
<p>1,252,895. Vibration damping laminated systems. FARBWERKE HOECHST A.G. 3 Dec., 1968 [5 Dec., 1967], No. 57350/68. Heading B5N. [Also in Divisions B2 and C3] A vibration damping laminated system comprises two plates, e.g. of metal such as steel, bonded together with an interlayer comprising a graft polymer of 55-90% by weight of an equimolar mixture of styrene and acrylonitrile on 45-10% by weight of a copolymer of 30-- 50% by weight of vinyl acetate and 50-70% by weight of ethylene. The graft polymer may contain minor amounts of fillers, e.g. heavy spar, silicic acid, graphite, soot or a mixture thereof, and one or more plasticizers. The total thickness of the laminated system may be 1-6 mm., the thickness of the interlayer being 0À1-1 mm. and the ratio of the thicknesses of the plates being from 1 : 1 to 4 : 1. The graft polymer may be applied to the plates by trowelling, brushing or pouring at elevated temperature and the system cooled under pressure between rollers. A gel of the copolymer in the styrene/acrylonitrile mixture to be grafted on which contains a polymerization initiator, e.g. tertiary butyl hydroperoxide, may be applied between the plates and the laminated system subjected to heating at 60-180‹ C. to effect grafting.</p> |
