| 摘要 |
Metals are coated or laminated with random ethylene terephthalate-2, 2-bis [4(beta-hydroxy-ethoxy) phenyl] propane terephthalate copolyesters in which the ethylene terephthalate units comprise from 80 to 20% of the sum of the units of the stated monomers, and the 2, 2-bis[4(betahydroxyethoxy) phenyl] propane terephthalate units from 20 to 80% thereof. In an example, bis-beta-hydroxyethyl terephthalate is prepared by heating dimethyl terephthalate and ethylene glycol, with zinc and manganese acetates as catalysts, in a stream of nitrogen, and is then reacted with 2, 2-bis (4-(beta-hydroxyethoxy) phenyl] propane by heating the reactants in the presence of ethylene glycol titanate as catalyst, in an atmosphere of nitrogen. The mixture is stirred, the rate of stirring and the pressure being reduced as the temperature is raised. Specification 766,290 is referred to.ALSO:A metal base is coated with specified copolyester resins by contacting the base, while maintained at a temperature of from 100 DEG C. to 300 DEG C. with the molten resin maintained at a temperature of from 150 DEG C. to 300 DEG C., the composite article then being cooled. The resins used are either (a) random ethylene terephthalate - ethylene isophthalate copolyesters in which the ethylene terephthalate units comprise from 80 to 30% of the sum of the ethylene terephthalate and ethylene isophthalate units, and the ethylene isophthalate units from 20 to 70% of said sum, or (b) random ethylene terephthalate-2,2-bis[4(beta hydroxyethoxy) phenyl] propane terephthalate copolyesters in which the ethylene terephthalate units comprise from 80 to 20% of the sum of the units of the stated monomers, and the 2,2-bis[4(beta hydroxyethoxy) phenyl] propane terephthalate units from 20 to 80% thereof. The preparation of the latter type of polyester is described (see Group IV(a)). Specified metals are aluminium, magnesium, copper, iron, chromium, silver and steel. The polyester may be applied to both sides of a metal sheet, or two or more metal sheets may be laminated by placing the molten polyester between the sheets and pressing them together. Wire or other continuous lengths of metal may be coated by continuously running the hot metal through molten polyester. The degree of adhesion obtained increases with the temperature of the metal, and if the metal is slightly roughened. Specification 766,290 is referred to. |
