| 摘要 |
1,248,296. Photographic vesicular materials. INTERNATIONAL BUSINESS MACHINES CORP. March 5, 1969 [March 14, 1968], No. 11662/69. Heading G2C. A vesicular material comprises two or more layers, each layer containing a binder and a radiation-sensitive material capable of decomposing on exposure to form a gas and wherein the binders of the different layers have different gas permeabilities. Generally there are two layers each layer containing the same two polymeric binders, a vinylidene chloride/acrylonitrile copolymer and an acrylic ester polymer, in different ratios i.e. 2-3:1 in one layer and 1:1 in the other layer. In the example, a polyester support is coated with a layer containing a diazonium salt and the copolymer and polymer in a 3:1 ratio and the layer is heated before applying a second layer containing the diazonium salt and the same copolymer and polymer in a 1:1 ratio. The material is then heated to increase the speed of the second layer by applying hot water thereto. The vesicular material obtained is stated to have a greater density range than prior art materials. |
