| 摘要 |
<p>1,134,967. Recovering polyester from scrap photographic film. EASTMAN KODAK CO. July 27, 1967 [July 27, 1966], No.34548/67. Heading G2C. In the recovery of polyester scrap from waste photographic film, subbing layers comprising a copolymer of a vinylidene halide are removed from subbed polyester base material, e.g. polyethylene terphthalate material, by heating said material with alkaline glycol until the subbing layers have flaked off. The cleaned polyester scrap may then be removed by screening and the subbing layer flakes may be removed from the alkaline glycol by filtration or centrifugation. The subbing layers comprise copolymers of 30-98% of vinylidene halides with 0À5-40% of acrylonitrile or an alkyl ester of acrylic, methacrylic or itaconic acid and 1-25% of acrylic, methacrylic or itaconic acid. Various polyester base materials are specified. The alkaline glycol may be ethylene glycol and is preferably the glycol corresponding to the polyester base material used. The glycol may contain as alkali NaOH, KOH, alkali-metal oxides, hydroxides and carbonates in general, alkaline earth metal oxides and hydroxides, quaternary ammonium hydroxides, tri-alkali metal orthophosphates and pyridine.</p> |
