US2158836A - Production of light-sensitive diazotype layers - Google Patents

Description

Patented May 16, 1939 PATENT OFFICE PRODUCTION or LIGHT-SENSITIVE nmzomn LAYERS Maximilian Paul Schmidt and Georg Werner,

Wiesbaden-Biebrlch, Germany,

assignors to Kalle & Co. Aktiengesellschatt, Wiesbaden- Biebrich, Germany No Drawing. Application March 27, 1937, Serial No. 133,384. ln Germany April 22, 1936 9 Claims.

The present invention relates to the production of light-sensitive diazotype layers.

Of the diam-compounds proposed for the positive diazo-type process only the diazo-compounds of the o-aminonaphthols and p-diamines have been able to attain any considerable practical importance. These diam-compounds are very light-sensitive,possess good lasting properties and are more or less coloured. Moreover they fade 10 during the exposure, so that a good white ground is obtained, and, when suitable azo-components are employed, they give dark colour tones.

The employment of other previously proposed coloured and stable diazo-compounds is open in part to the objection that their light-sensitiveness is low or that they do not fade sufllciently, which gives rise to prints having poor contrast. In particular, with the compounds in question the desired dark and strong colour tones are generally not obtained.

It is an object of the invention to produce new diazotype layers of high technical value. These layers can beapplied in the usual manner on or in a suitable support. 7

It has been found that light-sensitive layers containing a diazo compound of a para-aminodiphenyl which carries in the nucleus carrying the diazo group two alkoxy groups in 2- and 5- ..positions can be employed exceptionally advantageously for the diazotype process. The diazo compound of 4-amino-2,5-diethoxydiphenyl is a compound of this kind. The designations 1- or 1-position, respectively, in this specification indicate the places at which the benzene nuclei of the diphenyl are combined with one another. As alkyl groups in the alkoxy groups, methyl and ethyl are of particular value. The alkyl groups may also be propyl or butyl groups. Alkyl resi-.

dues of higher molecular weight are less suitable. 4 The compounds named are highly coloured, lasting and of good light-sensitiveness and they give,

even when the ordinary azo coupling components--for example, phloroglucine-are employed, dark colour tones which are fast to light.

The. new diam-compounds generally couple rather energetically, so that they are particularly suitable for the wet dia'zotype process. They may, however, also be applied to a base together with azo-jcomponents which couple more slowly,

such as, for example, naphthol sulphonic acids.

Layers are then obtain'edwhich can be developed either by the dry process withammonia, or by the wet process, for example with soda solution. In certain circumstances a paper containing the diazo-compound-if desired, together, with an Good results are in particular obtained with 5 I such compounds as contain in addition also ether groups in the other benzene nucleus preferably in 4-position, such as, for example the diazo-compound of 4-amino-2,5-diethoxy-4'-methoxy-diphenyl; 'As ether groups in the nucleus contain- 10 ing no diazo group methoxy-and-ethoxy groups are particularly suitable. In place of these groups also a methyl group can be employed. Such bodies substituted inboth nuclei give particularly deeply coloured layers, so that when copying the 15 formation of the image can be very readily followed. The layers may be exposed by the aid of the various customary sources of light. If desired, still further substituents, such as alkyl groups or halogens, may be introduced into the 20 molecule of the diam-compound, whereby the colour tones are more or less altered.

Examples of some preferred methods of carrying the invention into practice are set forth below: 25

(1) A 3% aqueous solution of the diazo-compound of,4-a1nino-2,5-diethoxydiphenyl which for the purpose of stabilization also contains a suitable acid, such as tartaric acid or boric 35 acid, and, if desired, a means for preventing yellowing, is painted on to a base of the usual kind and is exposed behind a pattern. By development with a weakly alkaline phloroglucine solu-- tion, for example a solution containing sodium 4 acetate, prints with brownish black lines are ob-'. taine'd.

(2) 31 grammes of the hydrochloride of the diazo-compound oi 4- amino-2,5,4'-trimethoxydigrammes of tri-sodium citrate, 4 grammes of phloroglucine and 15 grammes of acid sodium 55 tartrate in 1000 c. c. of water is employed. Prints with beautiful black lines are thus obtained. If

desired, other developers, which are somewhat more strongly alkaline or which contain other coupling components, may mo be used.

(3) 15 grammes of the zinc salt of the diazocompound of 4-amino-2,5-diethoxy-4'-methyldiphenyl, 20 grammes of tartaric acid, 50 grammes of sodium naphthalene trisulphonate and 20 grammes of sodium 1-naphthol-4,7-disulphonate are dissolved successively in 1000 cc. of water and coated on paper. Aiter'exposure behind a pattern the prints can be developed with ammonia gas or by the application of a weakly alkaline solution, which, for example, may contain sodium acetate or sodium bicarbonate.

(4) 30 grammes of the hydrochloride of the diazo-compound obtained from 4'-amino-2,5-diethoxy-4'-acetylaminodiphenyl, 20 grammes of citric acid, 5 grammes of boric acid, grammes of ammonium sulphate, 10 grammes of aluminium sulphate, 10 grammes of thiourea are dissolved in 1000 cc. of water. Paper coated with this solution is exposed after drying beneath a pattern. For the development a solution of 20 grammes of phloroglucine, 20 grammes of sodium acetate and 10 grammes of sodium bicarbonate in 1000 c.c. of water is employed. Prints with dark brown lines are obtained.

(5) 20 grammes of the chlorhydrate of the diazo-compound of 4-amino-2,5,4'-triethoxydiphenyl, 2 grammes of sodium bisulphate, 40 grammes of tartaric acid, 40 grammes of aluminium sulphate, 40 grammes of citric acid and 40 g.

of thiourea are dissolved in 1000 cc. of water in the stated succession. With this solutiona suit-' able support as for instance paper or cellulosehydrate foil is coated or impregnated respectively. The dried material is developed after exposing with a solution of 20 grammes of phloroglucine and 40 grammes of sodium bicarbonate in 1000 0.0. of water. Prints with black-brown lines are obtained. Instead of the mentioned diazo-compound also the diazo-cor'npound of 4-amino-2,5,5-

triethoxydiphenyl or the diazo-compound of 4- amino-2,5-diethoxy-4'-methoxydiphenyl may be employed.

(6) 20 grammes of the hydrochloride of the diazo-compound obtained from 4-amino2,5-di-nbutoxyi'-ethoxydiphenyl,- 40 grammes of tartaric acid, 20 grammes of thiourea are dissolved in water in the stated succession. Paper is coated with this solution. The development of the material may be efiected by means of a developer,

which contains 20 grammes of phloroglucine and 40 grammes of sodium acetate in 1000 cc. of water.

The lines of the obtained prints are black-blue.

We claim:

1. Light-sensitive layer comprising the monovdiazo compound or a 4-amino-2,5-dialkoxydiphenyl, which contains in the nucleus containing no diazo group a substituent selected from the group consisting of the methylgroup, the methoxy group and the ethoxy group.

2. Light-sensitive layer comprising the monodiazo compound of a 4-amino-2,5-dialkoxydiphenyl, which contains in the nucleus containing no diazo' group in the 4-position a substituent selected from the group consisting of the methyl group, the methoxy group and the ethoxy group.

3. Light-sensitive layer comprising the monodiazo compound of 4-amino-2,5,4-trimethoxydiphenyl.

4. Light-sensitive layer comprising the monodiazo compound of 4-amino-2,5,4-triethoxydiphenyl.

-5.vLight-sensitive layer comprising the monodiazo compound of 4-amino-2,5-diethoxy-4-- methoxydiphenyl. I

6. Light-sensitive layer comprising the monodiazo compound of a p-aminodiphenyl which carries in the nucleus containing-the 'diazo group two alkoxy groups in 2- and 5-positions.

'7. Light-sensitive layer comprising the monodiazo compound ofa p-aminodiphenyl which carries in the nucleus containing the'diazo group two alkoxy groups in 2- and 5-positions wherein the said alkoxy groups contain one to four carbon atoms.

8. Light-sensitive layer comprising the monodiazo compound of a 4-amino-2,5dialkoxydiphenyl wherein the said alkoxy groups contain one to. four carbon atoms, the diazo compound carrying. in the nucleus containing no diazo group a substituent selected from the group consisting of the methyl group, the methoxy group and the ethoxy group.

9. Light-sensitive layer comprising the monodiazo compound of a 4-amino-2,5dialkcxydiphenyl wherein the said alkoxy groups contain one to four carbon atoms, the diazo compound carrying in the nucleus containing no diazo group, in the 4'-position, a substituent selected from the group consisting of the methyl group, the methoxy group and the ethoxy group.

MAXIMILIAN PAUL SCHMIDT. GEORG WERNER.