| 摘要 |
1,257,235. Coated packaging materials. KRAFTCO CORP. 2 Oct., 1969 [5 Nov., 1968], No. 48478/69. Heading B2E. A method of making a wax coated packaging sheet material having improved separating characteristics comprises applying a layer of a homogeneous mixture of an amide of a higher fatty acid and a starch to the wax coating of a packaging sheet material comprising a base sheet and a wax coating, said amide having a molecular weight of at least 200 and being present in the mixture of a level of from 50 to 90% by weight, said starch being present in said mixture at a level of 10 to 50% by weight, said mixture being applied to said packaging material at a level of from 0.1 to 1.5 pounds per 3,000 square feet of said packaging material. The mixture, which may be in the form of an aqueous dispersion may be applied by dipping, spraying or rolling. The base may be of regenerated cellulose, which may be polymer coated, or other plastics material, paper or metal-foil. The wax coating is preferably of microcrystalline wax admixed with polyisobutylene or comminuted butyl rubber. The starch may be corn starch, potato starch or rice starch. Specified amides are amides of saturated and unsaturated waterinsoluble monocarboxylic acids, e.g. of oleic, arachidic, behemic or enuic acid and the reaction products of diamines, e.g. ethylene diamine with polymerised fatty acids which have been formed by polymerisation of unsaturated higher fatty acids at the double bond. |
