Patent GB-726755-A (GB)
Title: Improvements in or relating to photographic diazotype materials
IPC: G03C1/54
Filed: 1953-07-30
Abstract: 726,755. Photographic diazotype material. CHEMISCHE FABRIEK L. VAN DER GRINTEN N.V. July 30, 1953 [Aug. 13, 1952], No. 21183/53. Class 98 (2). One component diazotype material contains at least two different types (type I and II) of light-sensitive diazo compounds and has a total content of diazo compound of at least 0.3 millimol. diazo compound per m<SP>2</SP>. The novelty of this material consists in the following: it contains at least one diazo compound of type I of the following structure: wherein R 1  and R 2  represent an alkyl radical, X an anion and Y a substituent, which has, for rays of 4050 Š, an Epsilon value greater than 1.5 Î 10<SP>4</SP> and, for rays of 3650 Š, an Epsilon value lower than that for rays of 4050 Š; it contains at least one diazo compound of type II (described below) having, for rays of 3650 Š, an Epsilon value greater than 1.5 Î 10<SP>4</SP> and, for rays of 4050 ‰, an Epsilon value lower than for rays of 3650 Š, for rays of 4050 Š the Epsilon value of the diazo compound(s) of type I minus the Epsilon value of the diazo compound(s) of type II is at least 1.0 x 10<SP>4</SP>; for rays of 3650 Š the Epsilon value of the diazo compound(s) of type II minus the Epsilon value of the diazo compound(s) of type I is at least 1.0 Î 10<SP>4</SP>; the gamma value of the mixture of the diazo compounds of type I and II is less than that of material with the diazo compound(s) of type I or type II (whichever of these types has the lower gamma value) and the diazo compounds couple more rapidly than p-diazodiethyl-aniline. By " total content " of diazo compounds is to be understood the content of all the diazo compounds present in the diazotype material, i.e. the one or more diazo compounds of type I plus the one or more diazo compounds of type II, plus possibly other diazo compounds present in the diazo layer. The term " Epsilon " indicates the molar extinction coefficient, as measured in a layer of one centimetre thickness of an aqueous molar solution of the diazo compound. A method of determining the Epsilon values is described in the Specification. The diazo compounds of type II are not restricted to specific formulµ; but results of practical value are obtained with type II compounds of structure where R represents a cyclohexyl radical. The material is particularly valuable for copying from artistic tracings as of furniture or architectural subjects drawn in lead pencil and crayon, and may be used for copying from continuous tone dispositives. Semi-wet or thin film development with coupling components in the developer yields good prints. In example 1 the diazo compound of type I, the zinc chloride double salt of 1-diazo-4-diethylamino-3 chlorobenzene; and that of type II, the zinc chloride double salt of 1-diazo-4-monocyclohexylamino- 3-chlorobenzene, are separately dissolved in aqueous methyl cellulose solution containing the sodium salt of naphthalene-1: 3 : 6-trisulphonic acid and the solutions both separately and admixed are coated on to straw pulp paper, exposed under a neutral stopwedge, and developed by surface application of a solution containing potassium tetraborate pentahydrate, potassium hydroxide, thiourea, phloroglucinol, resorcinol, the potassium salt of hydroquinone monosulphonic acid, sorbitol and the sodium salt of isopropylnaphthalene sulphonic acid; to show gamma values of 2.3 and 2.4 respectively for papers treated with type I and type II solutions only, and the desirable gamma value of 1.9 for paper treated with an equal mixture of such solutions. In fourteen further examples the diazo compounds are, type I the zinc chloride double salts of 1-diazo-4-(N-methyl-N- cyclohexyl) amino-3-chlorobenzene, 1-diazo-4- diethylamino - 3 - iodo - benzene, 1 - diazo - 4 - diethylamino - 3 - benzoylamino benzene, 1 - diazo - 4 - diethylamino - 3 - methylbenzene, 1 - diazo - 4 - di - n - butylamino - 3 - chlorobenzene; 1 - diazo - diisobutylamino - 3 - sulphobenzene chloride and the stannic chloride double salt of 1-diazo-4-ethylethanolamino-3- chlorobenzene; and, type II, the zinc chloride double salts of 1-diazo-4-monoethylamino-3- trifluoromethyl benzene, 1-diazo-4-monoethylamino - 3 - chlorobenzene, 1 - diazo - 4 - mono - (4<SP>1</SP> - methylcyclohexyl) amino - 3 - chlorobenzene, 1 - diazo - 4 - monobenzylamino - 3 - chlorobenzene, 1 - diazo - 4 - monocyclohexylamino - 3 - trifluoromethylbenzene, 1 - diazo - 4 - monoethylamino - 3 - methylbenzene, 1 - diazo - 4 - ethyl - benzylaminobenzene, 1 - diazo - 4 - diethyl - amino - 2 - chlorobenzene. All examples provide full quantitative details of the sensitizing and developing solutions and Epsilon values of the diazo compounds used therein. More than one of either of the two types of diazo compounds may be used in the material, and the diazo mixture may include diazo compounds of neither of the two types, such as 1-diazo-2: 5- diethoxy - 4 - benzoylaminobenzene, 1 - diazo - 2 : 5 - dibenzyloxy - 4 - benzoylaminobenzene, 1 - diazo - 2: 5 - dibutoxy - 4 - acetylaminobenzene, 1 - diazo - 2 : 5 - diethoxy - 4 - ethylmercaptobenzene, 1 - diazo - 2 : 5 - diethoxy - 4 - (4<SP>1</SP> - ethoxyphenyl) benzene, 1 - diazo - 2 - diethylaminobenzene, 1 - diazo - 4 - phenylaminobenzene and 1-diazo-4-(4<SP>1</SP>-ethoxyphenylamino)- benzene.