| 摘要 |
<p>666,501. Moisture-proof wrapping paper. DEHN, S. G. (Munising Paper Co.). Dec. 17, 1948, No. 32728/48. Class 140. A moisture-proof sheet of self-sealing wrapping paper comprises a thin flexible paper sheet coated on one side with a flexible wax or wax with rubber film and completely coated on the other side with a cohesive substantially non- adhesive flexible dried wax-free film consisting essentially of unvulcanized synthetic or natural rubber including plasticized polyvinyl acetate. The rubber may be deposited from ammonia stabilized aqueous dispersions containing a minor amount of a water-soluble colloid, e.g. tapioca, starch or casein and hygroscopic substances, e.g. glycerine. The waxes may be beeswax, paraffin, montan, carnauba, or synthetic waxes applied as aqueous emulsions. The latex coating is applied to the surface 18 of the paper and also to the margins 19 on the other surface. The wax film 20 is applied between the margins 19. Articles may be readily wrapped by enclosing the article in the coated paper and bringing the latex films into contact with light pressure. The wax film may cover the whole of one surface of the paper.</p> |
