| 摘要 |
675,452. High gloss coated paper. CLAYTON, T. A. Sept. 29, 1950, No. 23845/50. Classes 96 and 140. High gloss paper is made by coating a paper web on one side with an aqueous dispersion of a thermoplastic resinous polymer having a second order transition temperature (T 2 ) between 55‹ and 125‹ C., e.g. polystyrene, polyethylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, or polymerized methyl methacrylate, optionally with synthetic rubber copolymers, e.g. butadiene-1,3 and acrylic nitriles having the formula where R is hydrogen or an alkyl group, e.g. 3 to 35 per cent thereof with 97 to 35 per cent of styrene, the web being dried and heated to 20‹ to 60‹ C. higher than the said temperature (T 2 ) and fed between the nip of a hard mirrorfinished glossing roll coacting with a resilient roll, the coated surface of the paper being in contact with the glossing roll for, e.g., 180 degrees angular distance, to heat the coating to a temperature T 2 + 40‹ to 80‹ C. - (P x 0.4 C.), where P is the percentage of plasticizer in the coating, and stripping the web tangentially from the glossing roll so that it travels in a straight line while the coating cools and sets. The heat and pressure, e.g. 200 to 1500 pounds per square inch, in the glossing press rolls cause the coating to flow to form a tenacious film, e.g. 0.00003 to 0.0002 inch thick. Dyes, fillers, pigments, and plasticizers may be included in the coating composition. As illustrated, paper 1 is coated as it passes between rolls 4, 5, is dried, and the coating set at a temperature T 2 + 20 ‹ to 60‹ C., glossed at a press 11, 12, and wound up at 14. Reference has been directed by the Comptroller to Specification 673,872. |
