| 摘要 |
1342202 Coating with preformed sheets AMP Inc 3 Feb 1972 [12 Feb 1971] 5059/72 Heading B6G [Also in Divisions C3 and F2] Articles are provided with tightly-fitting coverings (e.g. sheaths or linings) of a photolytically cross-linked ionomer, the coverings having a fusion-welded seam, by forming a loosely fitting covering to the article with one or more pieces of the ionomer in a heat-sensitive dimensionally unstable state, with a seam or seams between the edges of the piece or pieces, and heating the piece(s) of ionomer to fusionweld the seam or seams and return the ionomer to a dimensionally stable state as the tightlyfitting covering. The welded seam may extend axially or helically around the article. The ionomer is a copolymer of a C 2 -C 8 alpha olefin, e.g. ethylene, with an alpha, beta-ethylenically unsaturated monocarboxylic acid, e.g. acrylic, methacrylic or ethacrylic acid, at least 50% of the acid groups being neutralized in metal salt form. The ionomer is converted to the dimensionally unstable state by irradiating with ultraviolet light, shaping (e.g. into a sheet or ribbon), heating and subjecting the shaped ionomer to dimensional change while hot, and then cooling in the dimensionally changed state. (The product has a heat-responsive dimensional memory and will tend to return to its original dimensions when reheated; thus for sheaths a heat-shrinkable product is used and for internal linings a heat-expandable product.) The ionomers may include a filler, e.g. carbon black. Protective coverings can be applied to pipes, pipe-lines, telephone and telegraph cables, high-pressure couplings, high voltage cables and to thermal insulators such as fibreglass, glass foam, polyurethane foam, calcium and magnesium silicates and asbestos. |
