| 摘要 |
<p>947,602. Cylinder blankets. W. R. GRACE & CO. March 14, 1961 [Nov. 18, 1960], No. 9369/61. Heading B6C. [Also in Division B5] A cylinder blanket comprises a highly porous felted fibrous sheet impregnated with a mixture of rubbery and resinous polymers, the impregnated sheet having a firmness such that a pressure of at least 10 pounds per square inch must be exerted on the sheet to effect an initial impression of 2 mils, and a residual porosity at 4 mils of at least 37%. Residual porosity is given as total volume of sheet minus volume of fibres and rubber divided by the total volume of sheet, all measured while the sheet is compressed by 4 mils. In one example, a 115 pound ream weight natural fibre paper containing 100% mercerized cotton linters and having an average density of about 4 was impregnated with nitrile rubber latex modified with melamine resin such that the combined weight of rubber and resin was 80% of the fibre weight. The impregnated sheet was hot calendered, coated with a nitrile rubber ink-transfer surface 0.004 inch thick and press cured to a final thickness of 0.027 inch. This unit was then coated on the back with a 0.002 inch layer of a pressure-sensitive adhesive based on an acrylonitrile rubber. Other examples are enumerated in the Specification. Specification 936,206 is referred to.</p> |
