GB687558A - Improvements in antistatic photographic film - Google Patents

Abstract

687,558. Anti-static photographic film. KODAK, Ltd. Sept. 21, 1951 [Sept. 22, 1950], No. 22177/50. Addition to 678,329. Class 98 (ii). Improved anti-static properties are imported into the film of the parent Specification, in one of the layers of which is incorporated an alkali naphthalene formaldehyde condensate; by mixing with this condensation salt, before incorporation into the film, a surface-active spreading agent consisting of a higher fatty acid ester of a polyhydric alcohol, a sodium salt of an alkyl aryl sulphonate, a sodium salt of a fatty alcohol sulphate, a sodium salt of a sulphated higher fatty ester, a mixed fatty acid alkylolamine condensate, an alkylated aryl polyether alcohol or an ester of a polyethylene glycol with a higher fatty acid; the condensation salt forming from about 30 per cent to about 95 per cent of the mixture. An amine salt of the sulphonated naphthalene formaldehyde condensate may be used instead of an alkali metal or ammonium salt. Numerous proprietary products comprising surface-active spreading- agents of the above classes are listed. The mixture of condensation salt and surfaceactive spreading agent may be incorporated in the sensitive emulsion layer, in an overcoating layer or may be used as backing layer. Aqueous solutions are used when dealing with gelatine, otherwise aqueous-organic or organic solvents may be used. In four specific examples specified mixtures dissolved in aqueous methyl alcohol are applied by dip roller as a backing to cellulose triacetate film. Resistivity figures of treated and untreated film are quoted.