| 摘要 |
A film of regenerated cellulose is coated with a high molecular weight coating containing a synthetic montanic acid wax comprising technical montanic acids, defined as products having the character of that obtained by reacting deresinified crude montan wax with chromic acid, and may in fact be that product, and/or esters of such technical montanic acids. The high molecular weight coating may be of a copolymer of vinylidene chloride or vinyl chloride with each other or with one or more monomers e.g. acrylonitrile, vinyl acetate, acrylic or methacrylic acid esters, maleic, itaconic or aconitic acid. The wax may be present in the coating in an amount of from 0.5 to 8.0% by wt. The high molecular weight coating may be of a cellulose derivative such as nitrocellulose, and the wax may be incorporated in amount from 0.1 to 3.0% by wt. The synthetic montanic acid wax may be esterified with a glycol e.g. ethylene, propylene or butylene glycol. The glycol ester may be partially saponified with calciumhydroxide. The coating may contain an inorganic slip agent e.g. colloidal silica, chalk, aluminium oxide or talc. The film may be coated on one or both surfaces and the dry coating may be from 1 to 6 grams per square metre. |
