Patent GB-525810-A (GB)
Title: Process of making natural colour photographs
IPC: G03C7/26
Filed: 1938-12-23
Abstract: 525,810. Colour photography. SCHINZEL, K., and SCHINZEL, L. Dec. 23, 1938, No. 9089/40. Convention date, Dec. 23, 1937. Divided out of 37402/38. Addition to 521,746. [Class 98 (ii)] [Also in Group IV] In the method claimed in claim 1 or 2 of Specification 521,746, the azo-vat dye derivative is (a) one having a high molecular residue attached thereto through the azo linkage and in which after silver images have been produced in the layers the azo linkage is split image-wise by reduction in the silver areas only, the resulting simple vat due washed out and the remaining azo vat dye utilized for the image dye, (b) a leuco ester having a high molecular residue attached thereto through the azo linkage and in which after silver images have been produced in the layers the azo linkage is split image-wise by reduction in the silver areas only, the resulting simple leuco ester washed out, and the resulting azo vat leuco ester reduced to split the azo linkage and before or after splitting oxidized to remove the ester group, including a leuco ester having a residue of high molecular weight attached by the azo linkage to the radical of the acid used for esterification and in which the resulting simple leuco ester may be strongly basic so that it may be washed out by means of acid, or (c) a high molecular derivative of a meso derivative of the anthrone form of an anthraquinone dye having in the portion of the meso substituent between the anthraquinone and the azo bond a sulphonic or carboxylic acid group and in which after silver images are produced in the layers the azo linkage is split image-wise by reduction in the silver areas only, the resulting vat dye derivative washed out, and the meso substituent split off by oxidation to give a simple anthraquinone dye image. In the method claimed in claim 1 or 2 of Specification 521,746, the azo vat dye derivative is an azo vat dye having a high molecular residue connected thereto through the azo linkage. In the method claimed in claim 15 of Specification 521,746, the derivative is one obtained by coupling (a) an anthrone with a diazotized amino derivative of a basic compound such as a quaternary ammonium salt or (b) a diazotized aminoanthraquinone with a quaternary ammonium derivative of a phenol or naphthol. In the method claimed in claim 16 of Specification 521,746, the leuco ester is oxidized image-wise, the azo vat dye and redidual azo vat leuco ester reduced to split the azo linkages, the resulting simple vat dye reduced and washed out, and the simple leuco vat dye ester oxidized to the image dye. In the method claimed in claim 19 of Specification 521,746, the triphenylmethene dye is a derivative of an amino Malachite Green, or is replaced by the product obtained by coupling a diazotized amino derivative of a stable leuco dye or C-anilide with a phenol- or naphthol-sulphonic acid. Numerous azo vat dyes, azo vat dye derivatives and modified processes are described. The material may carry a sound track and also a layer in which a black image is recorded. Specifications 500,826, 503,752, 512,559, and 523,296 also are referred to. Azo vat dyes of high molecular weight are prepared by reacting isatoic acid anhydride or a nitrobenzoylchloride with an amino anthraquinone, an aminoindanthrene, an aminothioindigo, or another vat dye having amino, hydroxyl, or thiol groups, or on the amino group of an indole ring of an indigoid dye. After reducing the nitro group the external amino group is diazotized and coupled with components of high molecular weight such as oleylphenol or stearoylamino-#-naphthol or their sulphonic or carboxylic acids or with a polymer such as polyvinyl phenol. A diazo anthraquinone may be coupled with a component of high molecular weight. Salicoyl chloride or a hydroxynaphthoyl chloride may be reacted with the amino, hydroxyl or thiol group of a vat dye and the product coupled with a diazo compound of high molecular weight such as diazooleylbenzene or diazotized stearylaminonaphthalene. Azo vat dyes may be also formed using as azo-coupling components compounds formed by condensing the anthrone form of anthraquinone dyes having a hydroxyl, dimethylamino, acylamino, acetmethylamino, or methymercapto group with an amino or hydroxy-aldehyde. Azo-coupling components are also obtained by reacting salicylic acid chloride or one of its sulphonic acids on the carbonic esters or aminobenzylcarbonic acid esters of leuco vat dyes. Esterification may be effected with dimethylaniline-p-sulphonic chloride or quaternary ammonium bases. Anthrarilic acid chloride, isatoic acid anhydride or m-aminobenzoyl chloride may be reacted with an amino, methylamino, thiol, or hydroxyl group in a vat dye, and the amino group so introduced is diazotized and coupled with polyvinyl phenol or with the reaction product of maminophenol, or an amino-#-naphthol, or an aminophenylmethylpyrazolone with polyacrylic acid-chloride or stearic-acid chloride. Thioindoxylcarboxylic acid chloride or thioindigo carboxylic acid chloride may be reacted with m- or p-nitraniline and after reduction the amino group diazotized and coupled with the preceding components. An anthrone may be coupled with diazotized bases such as diazotized m-aminophenyltrimethylammonium chloride. A diazotized aminoanthraquinone may be coupled with a quaternary ammonium derivative of a phenol or a naphthol or a sulphonic or carboxylic acid thereof. Diazotized basic dyes such as diazotized amino Malachite Green or diazotized Safranine or oxidation-stable leuco derivatives or C-anilides may be coupled with phenolsulphonic acid or naphtholdisulphonic acid. Specifications 256,775, [Class 2 (iii)], and 521,835, also are referred to.