GB2053498A

GB2053498A - Diazotype Materials

Info

Publication number: GB2053498A
Application number: GB8017679A
Authority: GB
Original assignee: Filmfabrik Wolfen VEB
Current assignee: Filmfabrik Wolfen VEB
Priority date: 1979-05-31
Filing date: 1980-05-30
Publication date: 1981-02-04
Also published as: CH644700A5; FR2458096B1; GB2053498B; DD148910A3; FR2458096A1; CS235915B1; PL224628A2; JPS5629229A; DE3010056A1; PL120437B2

Abstract

One- or two-component diazotype materials which are sensitive to visible light of wavelength 500 to 600 nm, enabling the copying of red originals and exposure with green light, contain diazonium salts of the formula <IMAGE> in which each R1 and R2 is a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkoxy group having from 1 to 6 carbon atoms, a halogen atom, a fluorinated alkoxy group having from 1 to 4 carbon atoms, a cyanoalkoxy group having from 1 to 4 carbon atoms or a trifluoromethyl group; each R3 is a hydrogen atom or a halogen atom; each of R4 and R5 is an alkyl group having from 1 to 5 carbon atoms or an aralkyl group in which the alkyl moiety has from 1 to 5 carbon atoms, or R4 and R5 together with the nitrogen atom to which they are attached form a 5- or 6-membered saturated heterocycle; Y is a carbonyl group, a group -COOR6 in which R6 is an alkyl group having from 1 to 4 carbon atoms, a group CONR4R5 in which R4 and R5 have the meanings specified above, or a nitrile group; and X is an anion.

Description

SPECIFICATION Diazotype Materials This invention relates to diazotype materials.

Diazotype copying is based on the ability of certain aromatic diazonium compounds both to produce azo dyestuffs with colour couplers and to be deprived of their coupling capacity by the action of light. After exposure of the diazotype material containing the diazonium compound, the latent image obtained is developed by means of ammonia gas, an alkaline bath or thermally using additives that split off bases. The most widely used diazonium compounds in this respect are benzenediazonium salts having a 4-tertiary amino group and further substituents perferably in the 2 and 5-positions.

The properties required of diazonium compounds for their use in diazotype copying, for example a high light-sensitivity, and an adequate thermal stability and coupling capacity, are determined mainly by these substituents.

Such benzenediazonium salts having a 4-tertiary amino substituent absorb light mainly in the 350 to 450 nm range and their maximum absorption lies within this range: exposure must therefore be effected with light having a wavelength within this range. The presence of 2-tertiary amino substituents in the diazonium salts extend the maximum absorption up to 450 nm (H. Böttcher et a/.; J.

prakt. Chem. 315,725(1973)). The absorption maxima of diazonium salts of fused polycyclic aromatic compounds, for example pyrene, or of linked aromatic compounds, for example fluorene extend to 480 nm (T. Tsunoda et at Nippon shashin Gakkai Kaishi 29,27 (1966)). In US-PS 2,660,526, monodiazotised-4,4'-diamines of biphenyl and of stilbene are described for reflex processes; these diamines absorb light of even longer wavelengths.

Thus, the diazonium salts described hitherto for use in diazotype copying absorb light having a maximum wavelength of 500 nm only. Diazotype materials containing them are therefore sensitive only to exposure to UV and blue light.

The present invention seeks to provide diazotype materials which are sensitive to visible light, preferably of wavelengths of from 500 to 600 nm, and thereby permit the reproduction of originals that absorb in the range of visible light, preferably from 500 to 600 nm, as a result of their containing diazonium compounds that can be decomposed by light having wavelengths of from 500 to 600 nm and that can form coloured dyestuff images in the unexposed areas by basic development with one or more couplers.

According to the present invention, there is provided a one- or two-component diazotype material which contains a diazonium salt of the general formula

in which each R1 and R2 is a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkoxy group having from 1 to 6 carbon atoms, a halogen atom, preferably a fluorine or chlorine atom, a fluorinated alkoxy group having from 1 to 4 carbon atoms, a cyanoalkoxy group having from 1 to 4 carbon atoms or a trifluoromethyl group; each R3 is a hydrogen atom or a halogen atom, preferably a fluorine or chlorine atom; each of R4 and R5 is an alkyl group having from 1 to 5 carbon atoms or an aralkyl group in which the alkyl moiety has from 1 to 5 carbon atoms, or R4 and R5 together with the nitrogen atom to which they are attached form a 5- or 6-membered saturated heterocycle;; Y is a carboxyl group, a group -COOR6 in which R8 is an alkyl group having from 1 to 4 carbon atoms, a group -CONR4R6 in which R4 and R5 have the meanings given above, or a nitrile group; and X is an anion, for example TZnC142~, +CdCl42-, +SnCl82#, SbCl4- or BF4-.

The diazotype materials according to the present invention may contain stabilising acids, for example sulphosalicylic acid and oxalic acid. They may also contain couplers, for example naphthols, phenols and compounds with acidic carbon atoms.

Known binders for the production of diazotype materials, for example cellulose esters and polyvinyl alcohol, may be used as the film-forming polymer into which either the diazonium salt, the stabilising acid and the coupler (two-component systems) or the diazonium salt and the stabilising acid (one-component systems) are incorporated.

The diazotype materials may also include conventional support materials, for example plastics films, paper, transparent paper, transparentised paper and glass.

The diazonium compounds used according to the present invention have their maximum extinctions in the range of from 550 to 590 nm. Thus, using the diazotype materials of the present invention, it is possible to effect exposure with green light and to duplicate red originals.

The following Examples illustrate the invention.

Example 1 1000 cm of a 7.5% cellulose acetate solution in methylene chloride/methanol is poured onto a support having a surface area of 10 to 1 5 m2 and forms a transparent film. Into this film, there is incorporated the following diazo system: 10 g of di-(a-cyano-4'-dimethylamino-4-stibenediazonium) tetrachlorozincate; 10 g of 2,3-dihydroxynaphthalene; and 2 g of sulphosalicylic acid.

The diazotype material produced is exposed to an illuminated black or red original. The latent image formed is developed with ammonia and a red-brown image is obtained from the violet diazotype material. The UV-visible spectrum of this diazo system has an absorption mixture at 556 nm (see the accompanying drawing).

Example 2 1000 cm3 of a 7.5% cellulose acetate solution in methylene chloride/methanol is poured onto a support having a surface area of 10 to 1 5 m2 and forms a transparent film. Into this film there is incorporated the following diazo system: 10 g of di-(cg-carboxy-4t-morpholino-4-stibenediazoniurn) tetrachlorozincate; 7 g of p-naphthol; and 2 g of p-toluenesulphonic acid.

The diazotype material produced is exposed to a black or red original. The latent image formed is developed with ammonia and a red image is obtained from the violet diazotype material.

Example 3 1000 cm3 of a 7.5% cellulose propionate solution in methylene chloride/methanol is poured onto a support having a surface area of 10 to 1 5 m2 and forms a transparent film. Into this film there is incorporated the following diazo system: 10 g of di- [ a-methoxycarbonyl-3 '-methyl-4'-( 1 -pyrrolidinyl)-4-stilbenediazonium ] tetrachiorozincate; 7 g of acetoacetanilide; and 2 g of oxalic acid.

The diazotype material produced is exposed to a black or red original. The latent image formed is developed with ammonia and a yellow image is obtained from the violet diazo material.

Example 4 1000 cm3 of a 7.5% cellulose acetate solution in methylene chloride/methanol is poured onto a support having a surface area of 10 to 1 5 m2 and forms a transparent film. Into this film there is incorporated the following diazo system: 10 g of di(#-dimethylaminocarbonyl-4'-piperidino-4-stilbenediazonium) tetrachlorozincate; 4 g of naphthol AS-OL; 2 g of frnaphthol; 2 g of acetoacetanilide; and 2 g of oxalic acid.

The diazotype material produced is exposed to a black or red original. The latent image formed is developed with ammonia, a brown image being obtained from the violet diazo material.

Example 5 1000 cm3 of a 6% polyvinyl alcohol solution in water is poured onto a support having a surface area of 10 to 15 m2 and forms a transparent film. Into this film there is incorporated the following diazo system: 10 g of di-(#-cyano-4'-dimethylamino-4-stilbenediazoniu m) tetrachlorozincate; 8 g of R-salt; and 2 g of sulphosalicylic acid.

The diazotype material produced is exposed to a black or red original. The latent image formed is developed with ammonia, a red-brown image being obtained from the diazo material.

Example 6 1000 cm3 of a 7.656 Cellulose acetate solution in methylene chloride/methanol is poured onto a support having a surface area of 10 to 1 5 m2 and forms a transparent film. Into this film there is incorporated the following diazo system: 10 9 of di-((g-cyano-4t-dimethylamino-4-stilbenediazonium) tetrachlorozincate; and 2 g of sulphosalicylic acid.

The one-component diazotype material produced is exposed to a black or red original. The latent image formed is developed according to the collodion process at a constant pH of 28 with phloroglucinol and 2-hydroxy-3-naphthoic acid ethanolamide to produce a brown image.

Claims

1. A one- or two-component diazotype material which contains a diazonium salt of the formula

in which each R1 and R2 is a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkoxy group having from 1 to 6 carbon atoms, a halogen atom, a fluorinated alkoxy group having from 1 to 4 carbon atoms, a cyanoalkyl group having from 1 to 4 carbon atoms or a trifluoromethyl group; each R3 is a hydrogen atom or a halogen atom; each of R4 and R5 is an alkyl group having from 1 to 5 carbon atoms or an aralkyl group in which the alkyl moiety has from 1 to 5 carbon atoms, or R4 and R5 together with the nitrogen atom to which they are attached from a 5- or 6membered saturated heterocycle; ; Y is a carbonyl group, a group --COOR, in which R6 is an alkyl group having from 1 to 4 carbon atoms, a group CONR4R5 in which R4 and R5 have the meanings specified above, or a nitrile group; and X is an anion.

2. A one- or two component diazotype material according to claim 1 substantially as described in any one of Examples 1 to 6 herein.