| 摘要 |
1479630 Coated pipes YOUNGSTOWN SHEET & TUBE CO 11 Dec 1974 [26 Dec 1973] 53617/74 Heading B2E [Also in Divisions B5, C3 and F2] A centrifugally-cast pipe has a fibre-reinforced body of a thermosetting resin (P), and on the inside has an unreinforced lining of a flexible thermosetting resin composition (Q) comprising an ethylenically-unsaturated monomer (D), e.g. styrene, and a thermosettable resin (R) which is the reaction product of (A) an epoxy resin, (B) a carboxyl-terminated elastomer, and (C) a monocarboxylic acid having terminal double-bond. (B) may be a butadiene polymer or a butadiene/acrylonitrile copolymer. (C) may be (meth)acrylic acid. There may be equal weights of (R) and (D). The pipe may be formed by inserting a sock of fibrous reinforcing material into a centrifugal-casting mould, inserting enough resin (P) to encapsulate all the material, rotating the mould so as to distribute resin (P), injecting composition (Q), and curing. The two resins may be cured simultaneously, or (P) may be cured first.
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