Patent GB-535341-A (GB)
Title: Improvements in or relating to light-sensitive photographic material
IPC: G03C7/327
Filed: 1939-10-04
Abstract: 535,341. Polyvinyl acetals. DU PONT FILM MAUFACTURING CORPORATION. Oct. 4, 1939, No. 27170. Convention date, Oct. 5, 1938. [Class 2 (iii) [Also in Group XX] Photographic light-sensitive material comprises a support bearing a light-sensitive layer and a polyvinyl acetal which is capable of coupling with an aromatic or heterocyclic diazo compound or with an oxidation product of an aromatic amino photographic developing agent or with a nitroso compound to form a water insoluble dye. The acetal may be soluble in dilute alkaline solution, and may couple with diazonium salts, syn-diazotates, diazoanhydrides, and diazo-inner salts such as diazotizedo-aminophenol and diazotized sulphanilic acid. The acetals may be formed by reacting polyvinyl alcohol or a partially hydrolyzed polyvinyl ester with an aldehyde containing an aromatic nucleus containing a phenolic hydroxy, alkoxy, aryloxy, amino, alkylamino, arylamino or mixed alkylarylamine group and a reactive position ortho or para to such group. The aldehyde may contain in its molecule a reactive methylene group. Alternatively an acetal not of the above structure may be modified to the above structure. In examples, an acetal formed by the reaction of polyvinyl alcohol, salicylaldehyde, glacial acetic acid, and phosphoric acid is, incorporated in an emulsion ; the resin is prepared in a similar manner, but with the addition of isobutyraldehyde after partial reaction, and in a further example with the addition of phthalaldehydic acid; a resin is produced by the reaction of polyvinyl alcohol, m-hydroxybenzaldehyde, glacial acetic acid, phthalaldehydic acid, and phosphoric acid, followed by further heating with phosphoric acid : the resin obtained by reaction of polyvinyl alcohol glacial acetic acid, o-nitrobenzaldehyde, phthalaldehydic acid and phosphoric acid is reduced with sodium hydrosulphate, and reacted with ethyl aceto-acetate in the presence of pyridine. Further examples comprise the reaction products of (a) polyvinyl alcohol, 2-hydroxy-3-methylbenzaldehyde, phthalaldehydic acid. glacial acetic acid, and phosphoric acid ; (b) as (a) with 3-chlor-2- hydroxybenzaldehyde in place of 2-hydroxy-3- methylbenzaldehyde ; (c) as (a) with 5-chlor-2- hydroxybenzaidehyde in place of 2-hydroxy-3- methylbenzaldehyde; (d) polyvinyl alcohol, 3-alkyl-2-hydroxybenzaldehyde, phthalaldehydic acid, glacial acetic acid and phosphoric acid and (e) polyvinyl alcohol, 1-hydroxy-2- naphthaldehyde, phthalaldehydic acid, glacial acetic acid, and phosphoric acid. The polyvinyl alcohol may be replaced by a partially hydrolized polyvinyl ester, and the acetal may be prepared from a polyvinyl ester by simultaneous hydrolysis and acetalization. The acetal may be prepared from a mixture of aldehydes by simultaneous or step-wise reaction or from the products of hydrolysis of inter-polymers of vinyl esters and other unsaturated compounds. In a further example the acetal is prepared by the reaction of polyvinyl alcohol, salicylaldehyde, the diethyl acetal of glyoxylic acid, glacial acetic acid, and phosphoric acid. Other acetals referred to are polyvinyl acetals formed from 1'4- hydroxynaphthaldehyde, 3-methylaminobenzaldehyde, 4 - hydroxy - 3 -, methoxybenzaldehyde, 1 - (2 - formylphenyl - 3 - methyl - 5 - pyrazolone, 1 - (3 - formylphenyl) - 3 - methyl - 5 - pyrazolone, 1 - (4 - formylphenyl) - 3 - methyl - 5 - pyrazolone and o, m and p-acetoacetaminobenzaldehyde, 3 - brom - 2 - hydroxy - benzaldehyde, 2 - hydroxy - 3 - nitrobenzaldehyde, 6 - hydroxy - 2 - methylbenzaldehyde, 2 - hydroxy - 5 - methylbenzaldehyde and p - hydroxyphenyl - acetaldehyde. Acidic saltforming groups such as carboxylic and sulphonic, or phenolic hydroxy and merceptan groups, may be introduced by reaction of the polyvinyl alcohol or partial acetal thereof with aldehydes containing carboxylic or sulphonic groups such as phthalaldehydic, glyoxylic, and propionaldehyde-beta-sulphonic acids. Alternatively half-esterification with dibasic acid anhydrides such as phthalic or maleic anhydride or etherification with halogenated acids such as chloracetic acid, may be effected. These reactions may proceed simultaneously or successively in any order. The acidic group may. be in the colour-forming nucleus as in the case of 3-carboxy-2-hydroxybenzaldehyde, or may be introduced by sulphonation. Reaction with aldehydes such as formaldehyde, acetaldehyde propionaldehyde, n- or iso-butyraldehyde, and cyclic ketones, such as cyclohexanone, 3-methylcyclohexanone, 3, 5-di-methylcyclohexanone, 2-methylcyclohexanone, 1-ethylcyclohexanone, 2-bromocyclohexanone, and oxotetrahydronaphthalenes or both, may be effected for modification. The catalyst may be phosphoric, hydrochloric, perchloric, sulphuric, or p-toluenesulphonic acid, aluminium chloride or boron trifluoride. The colour developing agent may be a p-phenylenediamine derivative,1:4-naphthylenediamine, or 4-diethylamino-1 naphthylamine. The acetals may be incorporated in colloids, such as gelatin, gum arabic, or albumen, sensitized with bichromate. The unexposed colloid may be removed with hot water and dye produced by treatment with p-nitrosoaniline or its derivatives, or colour development may be effected. The acetals may be incorporated in viscose dope, a film produced from the composition, and colour produced by treatment with a diazo compound. Specification 133,034, [Class 98 (ii)], is referred to.