| 摘要 |
1,177,149. Coated paper. EASTMAN KODAK CO. 9 Nov., 1967 [14 Nov., 1966], No. 51000/67. Heading B2E. [Also in Divisions C3 and G2] Paper coated on both sides with polyethylene is coated on one polyethylene surface with a mixture of colloidal silica and at least one alkali metal salt of an alkyl aryl polyether sulphonate to reduce the accumulation of electrostatic charges thereon. The polyethylene coating may be applied by hot melt extrusion or lamination of a preformed sheet. The paper stock may be tub sized with a mixture of gelatine and a conducting salt, e.g. an alkali metal sulphate such as sodium sulphate, which acts as an internal antistat and provides for improved antistatic properties of the final product. The paper stock may be subjected to electron bombardment prior to the application of the polymer coatings. A primer of a polyalkylene amine such as polyethylene imine can be used to improve adhesion of the polymer to the paper. A polymeric dispersing agent such as sodium or potassium polyacrylate and an alkali metal salt of acrylic acid copolymers may also be present as well as additives such as zinc oxide, hydrochloric acid, citric acid or oxalic acid, the acids being present in amounts of from 10 to 50% based on the weight of the colloidal silica. A thickening agent such as a polysaccharide or a spreading agent such as tridecoxyhexaethoxy sulphonic acid may be included in the coating mixture which may be coated in amount of from 0.1 to 1.0 gm./sq. metre. Binding materials may also be included in the coating composition, for example, hydroxyethyl cellulose, a polystyrene latex, a styrene butadiene copolymer latex or a water soluble polymer such as polyvinyl alcohol. The wire side of the paper may have a coating of a styrene-butadiene copolymer before the polyethylene coating. Deliquescent salts such as calcium chloride, zinc chloride, zinc nitrate and potassium nitrite may be employed to increase the conductivity of the coatings. A silver halide emulsion layer may be coated on the other polyethylene surface. |
