GB1007320A - Process and apparatus for producing polylactam films - Google Patents

Abstract

1,007,320. Making polylactam films. POLYMER PROCESSES Inc. March 4, 1964 [March 15, 1963], No. 9132/64. Drawings to Specification. Heading B5B. Polylactam (Nylon) films are made by effecting polymerization of a lactam monomer in a mixture of the monomer, a polymerization catalyst and a polymerization promoter and, at the point when the viscosity of the mixture has increased but the mixture is still flowable, applying the mixture to a filmforming or casting surface and flowing the mixture into the form of a sheet in the filmforming or casting surface and completing the polymerization of the mixture by heating it while it is in contact with the casting surface. The lactam monomer preferably contains 6 to 20, more preferably 6 to 12 carbon atoms in the molecule, the catalyst is anionic and is preferably a Grignard compound, or an alkali metal or an alkali metal hydride. Preferable promoters are isocyanates and N-substituted imides. The film-forming surface may comprise a moving smooth metal surface, such as the peripheral surface of a rotating metal drum or the surface of an endless metal belt, and the formed nylon film may be continuously stripped from the surface. The shaping of the film is preferably completed prior to the formation of spherulites in sufficient quantity to cause volume fixation of the polymerizing mass. The lactam may be epsilon-caprolactam. The temperature of the mixture initially deposited on the film-forming surface may range from about 110‹ to 200‹. The film is preferably formed under anhydrous conditions and in the presence of an inert gas. The film may be passed through a quenching bath after being stripped from the drum or endless belt. Lists of lactam, anionic polymerization catalysts and promoters are given in the Specification. Specification 914,022 is referred to.