GB537081A - Improvements in or relating to light-sensitive photographic materials - Google Patents

Abstract

537,081. Photographic anti-helation layers. DU PONT FILM MANUFACTURING CORPORATION. Dec. 6, 1939, No. 31648. Convention date, Dec. 13, 1938. [Class 98 (ii)] Light-sensitive photographic material comprises a transparent support carrying a lightsensitive layer on one side and an anti-halation layer on the other side comprising an antihalation dye or pigment and a polymeric nitrogen compound which contains one or more amino groups and which is insoluble in water and 5 per cent. ammonium hydroxide solution but which is soluble in 5 per cent. aqueous acetic acid, preferably in 2 to 5 per cent. aqueous acetic acid. The light-sensitive layer may be a panchromatic or orthochromatic emulsion layer. The nitrogen compound may be deacetylated chitin ; an acid-soluble reaction product of a protein with a carboxyl compound such as a lower aliphatic aldehyde or ketone and an amine having less than nine carbon atoms in which the amino-nitrogen is joined to the aliphatic carbon; an amino cellulose soluble in dilute acetic acid and containing an amino-nitrogen atom removed from the cellulose nucleus by at least one carbon atom; cellulose amines soluble in a stoichiometrical amount of 5 per cent. acetic acid and containing directly attached to the cellulose nucleus from 0.5 to 1.5 amino nitrogens per glucose unit; the reaction products of vinyl ketone polymers with amino compounds ; the products obtained by treating resins having ketone groups with excess ammonia or amines and catalytically hydrogenating; polymeric amino alcohol esters of acrylic and substituted acrylic acids ; and polymeric alcohol methacrylates. The compounds may be used singly or in admixture. Resinous reaction products of phenols, aldehydes and ammonia or primary or secondary amines may be used, for example the reaction product of m-cresol, formaldehyde, and dimethylamine. Examples specified are piperidylmethylzein, dimethylaminomethylzein, dimethylaminoethylzein, and dicyclohexyl aminoethyl methacrylate. The dyes may be water-or spirit-soluble and may be blue, green, yellow, magenta, or red, or may be used in combination to give black or deep blue. Black or red antihalation layers are used with blue-sensitive or orthochromatic emulsions, and black, green or deep blue with panchromatic emulsions. Numerous dyes are specified. Naturally occurring pigments, metallo-dye complexes, and inorganic coloured compounds may be used. The layer may be applied by dipping, transfer, spraying, beading, or immersion beading. The antihalation layer may be rendered soluble before fixing by treatment in an acetic or citric acid bath, such as a stop bath. The emulsion layer may contain sensitizers such as cyanines, carbocyanines, pseudocyanines or cyazine bases or salts. The antihalation layer may be permanent, the dye concentration being reduced and alum added to the coating solution. Specifications 475,131 and 475,132, [both in Group IV], are referred to. Reference has been directed by the Comptroller to Specification 517,559.