| 摘要 |
1,143,583. Synthetic resin compositions. KONINKLIJKE NEDERLANDSCHE MACHINEFABRIEK V/H E. H. BEGEMANN. 8 March, 1966 [9 March, 1965], No. 10166/66. Headings C3B, C3P and C3R. [Also in Division B1] A composition comprising a thermosetting resin, e.g. an epoxy resin, a phenolic resin or an unsaturated polyester (100 parts by weight), from 25-35 parts by weight of a reinforcing fibrous material having length of 3-8 mm. and from 50-150 parts by weight of a non- fibrous filler (e.g. quartz of particle size 30Á) is subjected to a repeated kneading operation in which parts of the mixture are removed from the kneading zone and returned later. In this way at least 80% of the fibres which are initially present in bundles become separated into individual fibres. The temperature in the kneader is kept below the polymerization temperature of the resin. Examples of typical compositions are (1) polyester resin (100 parts by weight), glass fibres (30 parts), asbestos powder of max. particle size of 50Á, quartz powder of max. particle size 30Á; (2) 100 parts by weight of epoxy resin, 35 parts by weight of glass fibres and 50 parts by weight of asbestos powder (50Á). The diameter to length ratio of the fibres may be in the range 1: 200 to 1: 500. The fibres should be completely enclosed by polymerized resin, i.e. the length of the fibres should be at least as small as the minimum cross-sectional dimension of the article. |
