US2245628A

US2245628A - Reflex copying process

Info

Publication number: US2245628A
Application number: US200162A
Authority: US
Inventors: Poser Gottlieb Von; Scherer Theo; Sus Oskar
Original assignee: HELGE SVENSON
Current assignee: HELGE SVENSON
Priority date: 1937-04-05
Filing date: 1938-04-05
Publication date: 1941-06-17
Anticipated expiration: 1958-06-17
Also published as: GB503996A

Description

Patented June 17, 1941 REFLEX COPYING PROCESS Gottlieb von Poser. Theo Scherer, and Oskar Siis, Wiesbaden-Biebrich, Germany, assignors, by mesne assignments, to Helge Svenson, Goteborg, Sweden No Drawing. Application April 1938, Serial No.

200,162. In Germany April 5, 1937 14 Claims. (or 95-5) This invention relates to an improved reflex copying process.

It is known to duplicate originals which are hardly transparent or which have been written or printed upon on both sides in such a manner that a so-called reflex copy thereof is first made and the latter then reproduced in any suitable manner. For this purpose transparent papers, which are sensitized with the usual silver compounds, which are generally. employed in photography, are used' as reflex copying materials. To reproduce the reflex copies thus obtained, papers rendered sensitive to light by means of diazo compounds are frequently used. This process has the disadvantage that the development and'fixation of the reflex copies is comparatively complicated, since a number of baths must be used. It is, moreover, a disadvantage that negative reflex copies are obtained, so that it is necessary before reproducing on diazo printing material to reverse them or first to make a positive intermediate copy on photographic material.

It has already been proposed also to sensitize the reflex copying materials with diazo compounds, if desired with the addition of azo com- I ponents, since, by using such materials, the aforesaid disadvantages are avoided. With the use of the normal diazo compounds andazo components usual in diazotype processes, reflex copies are generally obtained which, however, can only be very badly reproduced on papers sensitized with diazo compounds and thus, on the whole, result in quite useless copies with wholly insufficient contrasts. That is one of the reasons that such a process could not hitherto be introduced in practice. v

It has now been found that, contrary to former experience, reflex copies, whichcan be successfully reproduced on the usual diazo-photo-printing papers, can be made by using diazo compounds and azo components, if. the diazo compounds and azo components are chosen in a definite manner.

According to this invention those diazo compounds and azo components are used whichJon developing, give dyes which absorb light chiefly in the region between about 3300A. to 4400 A. Such azo dyes are in general yellow to greenishyellow. The excellent suitability of such reflex copies for reproduction on diazo photo printing material depends upon the fact that theprint dyestuffs absorb light in the same range of the spectrum as the diazo compounds generally used in photo printing processes.

This mode of procedure is contrary to the rules tinguishable. The reflex copies obtained by the new'process however are quite indistinct, and, owing to the light tones of the lines, barely legible. In spite of this, they are eminently suitable for reproduction.

As a support for the light sensitive compound,

in accordance with the invention, cellulose hy drate sheets or foils are preferably used. Advantageously, the cellulose hydrate sheet is sensitized with the diazo compound and the azo component, so that the material may be developed according to the dry method. It is, however, also possible to spread on the diazo compound alone and then to develop the material by the wet method. Instead of a single diazo compound or a single azo component, mixtures of several diazo compounds or mixtures of. several azo components can also be used. Hereby it can be advantageous to add small "quantities of'a diazo compound or an azo component yielding darker tones to the mixture of dyestuii' component. Thus are obtained reflex copies with darker tones which are better legible. Besides these substances, the sheet or foil can also contain bleaching dyes, such as, for example,

pinacyanol, with or without sensitizers, such as,/

for example, thiosinamine.

The reflex-copying process can be still further improved if, during the reflex copying, a further sheet, rendered light sensitive by means of bleaching dyes or diazo compounds, is interposed between the source of light and the reflex copying material, preferably'in contact with the latter.

This sheet can, for example, be prepared with the same diazo compound as the reflex copying material. An improvement in the reflex copies can furthermore be obtained, namely by using, during the reflex copying, filters which contain stable substances absorbing ultra-violet light. Such substances are, for example, esculine, esculetine, fi-methylumbelliferone-carbonic acid andpyrenedisulphonic acid or the corresponding alkali-salts. The process may, moreover, be so carried out that the ultra-violet light-absorbing substances, which are preferably colorless or only very slightly colored, are spread on one side of a sheet, while the light sensitive preparation is spread on the other side.

Surprisingly, it is even possible to incorporate these ultraviolet light absorbing substances directly in the light sensitive layer.

In carrying out the process, alkylphenols, for example, with one or more alkyl-groups, especially methylor ethyl-groups, in which the alkyl group or one of the alkyl groups carries a substituent known to increase the solubility in water, are suitable as azo components. Such substituents are, for example, basic groups such as amino groups. These may be monoor disubstituted. As examples, the dimethylaminoor the phenylamino-group may be mentioned. Other suitable substituents are the carboxylgroup and the hydroxyl-group. The sulphogroup may also be used, although the other substituents named are in general more advantageous. Compounds of the type in question may, for example, be derived from cresols, such as the ortho-cresol or the meta-cresol. Xylenols, such as 1.4-dimethyl-2-phenol, or trimethylphenols, for example 1.3.4-trimethyl2-phenol are also suitable. A few of the azo components which can be used are, for example, 1-hydroxymethyl-2- phenol, the p-(2-hydroxyphenyl)-propionic acid CHr-CHr-COOH 2- (w-phenylamino) -metl'iyll-hydroxybenzene and 2- (w-dimethylamino) {methyl 1 hydroxy. benzene T",

CH: CHrN The latter compound is prepared by treating o-nitrobenzylchloride with dimethylamine, reducing, diazotizing and boiling-out. In the same way the corresponding substitution products of metacresol can be used. Also suitable for use are, for example, the following compounds: l-oxymethyl- 2-hydroxy-4methyl-benzene, l-(w-phenylamino) methyl-2-hydroxy-4-methylbenzene, p-(i-methyl-2-hydroxyphenyl) -glutaric acid CHr-COOH 1.4-dimethyl-2 hydroxy- 3 hydroxymethylben zene, l-hydroxymethyl-z-hydroxy 3 methoxybenzene, and l-(w-phenylamino)-methyl-2-hydroxy-B-methoxybenzene. The compounds mentioned can also, if desired, contain still further substituents provided that the latter do not appreciably alter the absorption of the dyestufis. Additional unsubstituted hydroxyl-groups are not suitable as substituents for the above reasons.

. Substituents which appreciably decrease the solubility or the coupling power are also unsuitable.

The said azo components give suitably good coating dyes with the proven tertiary or particular secondary para-amino-diazo compounds, for example, those which do not have in the amino group too long alkyl groups but only methylor ethyl-groups. Particularly advantageous are those para-amino-diazo compounds which have a methyl group in juxtaposition to the amino group. For example 4-monoethylamino-3-methyl-l-benzenediazoniumchloride is very suitable. Good results are also obtained with 4-dimethylaminobenzene-l-diazoniumchloride or the 4-diethylaminobenzene-ldiazoniumchloride. When carrying out the present invention it is advantageous to choose the dyestuff components in such a manner that, on developing, the dyestuff is formed as complete and as quick as possible. Thus, when using azo components which couple only with comparative difficulty, one should use diazo compounds with great coupling activity as, for example, para-aminodiazo compounds which have as substituents a dichlorbenzyl residue in the amino group.

The following examples illustrate the invention:

1. Cellulose hydrate sheets are soaked in a solution of 12 grams of the diazonium chloride of 1-amin0-2-hydr0xy-4-ch1orbenzene-6 sulphonic acid, 15 grams phloroglucine, 10 grams thiourea and 10 grams tartaric acid in 1000 ccm. water and dried. During the preparation of a reflex copy with this material, for which an arc lamp with a dull glass globe may, for example, be used as the source of light, a cellulose hydrate-sheet, which is prepared by dipping it for 1-2 minutes in a .3% aqueous solution of 4-methyl-umbelliferone-carbonic acid (in the form of the sodium salt) is laid on the side of the reflex copying material facing the source of light. The said diazo compound is prepared by diazotizing 2.4-dichlorl-aniline-fi-sulphonic acid and treating the diazo compound with soda solution, one chlorine atom being replaced by the hydroxyl group.

2. Sheets of regenerated cellulose are placed for 1-2 minutes in a bath containing a solution of 15 grams of the zinc chloride double salt of 4-dimethyl-aminobenzene -,1- diazoniumchloride, 10 grams phenol, 12 grams tartaric acid and, if desired, softening and wetting agents in 1006 ccm. of-water, and are then squeezed-out. The dried sheet is laid upon the original to be copied and exposed through the sheet for about 1 minutes in sunlight. After the exposure the sheet is developed by means of ammonia gas; a greenish-yellow print results which can be reproduced in the normal way on diazo photo printing papers.

3. The procedure of example 2 is followed, but for the sensitizing of the sheet a solution is used containing in 1000 ccm. water 15 grams of the zinc chloride double salt of 4-monoethylamino-3-methyl benzene-1-diazoniumchloride, 12 grams of 2.5-dimethyl-6-w-dimethylaminomethyl-l-phenol CH2.N

12 grams citric acid and 2 grams esculine. The 2.5 dimethyl 6 w dimethyl aminomethyl-lthe following pages.

phenol is obtained by condensation of 2.5-dimethyl-l-phenol with formaldehyde and dimethylamine after the known method described in Annalen der Chemie, vol. 343, page 280 and 4. 14 grams of the zinc chloride double salt of 4-diethylamino-benzene-l-diazoniumchloride are dissolved in 1000 com. water together with 12 grams phenol, grams tartaric acid and 2 grams methylesculetine. A sheet prepared with this solution is suitable for the preparation of reflex copies which reproduce well.

5. 70 grams of the zinc chloride double salt I of 4-dimethylamino-2emethyl-benzene-1-diazoniumchloride are dissolved in 1000 com. water together with 55 grams of 2.5-dimethyl-6-w-di methylamino-inethyl-l-phenol and grams tartaric acid. This solution is spread on one side of a superficially saponified sheet of acetyl cellulose. When making a reflex copy with the aid of this sheet the prepared side of the sheet is brought into contact with the original. On developing in ammonia, a greenish yellow dye is formed. If a particularly high standard is required for the print to be made therefrom, the

reflex copy can first once again be copied in the normal way on the material used for the reflex copying and the final copy.prepared from this intermediate copy. 1

6. A cellulose hydrate sheet is rendered sensitive to light by placing in a bath containing a solution of 15 grams of 4-(26-dichl0rbenzyl)- amino-l-benzenediazoniumsulphate, 11 grams of 2- (w-phenylamino) -methyl-l-hydroxybenzene, 10 grams thiourea and 10 grams tartaric acid in 1000 com. water. A reflex copy. is then prepared in the usual manner by developing with ammonia gas. The reflex copy can be reproduced well on normal diazo photo printing paper as the resultant greenish-yellow dye has an excellent coating capacity. Similar efi'ects can also be obtained if, instead of 2-(w-phenylamino)- methyl-l-hydroxybenzene, the following components are used: p-(Z-hydroxyphenyhpropionic acid, 2-(w-dimethylamino)-methyl-1- hydroxybenzene, 5- (3-hydroxyphenyl) -propionic acid, 3-(w-dimethylamino)-methyl-1-hydroxybenzene, 3-(w-phenylamino) -methyl-1-hydroxybenzene, 1-hydroxymethyl-2-hydroxy-3-methoxybenzene and .l-(w-phenylamino) -methyl-2- hydroxy-3-methoxybenzene. The 2- w-dimethylamino) -methyl-1-hydroxybenzene is prepared initially from o-nitro-benzylchloride, by substitution of a dimethyl-amino residue for the chlorine, reduction of the nitro group to the amino group, diazotizing and by boiling-out. The preparation of 3-(w-dimethylamino)-methyl-1- hydroxybenzene is similar.

7. The procedure according to Example 6 is followed, but for sensitizing the sheet a solution of 15 grams of the zinc chloride double salt of 4-monoethylamino-3-methylbenzene-1-diazoniumchloride, 12 grams of l-(w-phenylaminmmethyl-2-hydroxy-4-methylbenzene, 10 grams thiourea and 10 grams citric acid in 1000 ccm. water is used. With similar results, instead of 1-(w-phenylamino)-methyl 2 hydroxy 4 methylbenzene, 1-hydroxymethyl-2-hydroxy-4- methylbenzene, 1,4-dimethyl 2 hydroxy-S-hydroxymethylbenzene and c-(4-methyl-2-hydroxyphenyD-glutaric acid may be used. The latter is prepared by condensation of m-cresol and acetone-dicarbonic acid to the corresponding cumarine-acetic acid, alkaline cracking of this product and catalytic hydrogenation.

We claim:

1. In a process for producing a reflex copy, the steps which comprise placing a lightsensitive material sensitized by means of a diazo compound and an azo component which, on development, yield a. yellow to greenish-yellow dye, the chief absorption of which extends over the region of'about 3300 A. to about 4400 A. upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive material developing the image thereon and reproducing the developed image on a diazo-photo printing material by direct contact methods.

2. In a process for producing a reflex copy, the steps which comprise placing a light-sensitive transparent material sensitized by means of a diazo compound and an azo component which, on development, yield a yellow to greenish-yellow dye, the chief absorption of which extends over the region of about 3300 A. to about 4400 A. upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive transparent material developing the image thereon and reproducing the developed image on a diazo-photo printing material by direct contact methods.

3. In a process for producing a reflex copy, the steps which comprise placing a light-sensitive transparent material sensitized by means of a para-amino diazo compound and an alkyl phenol which contains only one phenolic hydroxyl group upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive transparent material developing the image thereon and reproducing the developed image on a diazophoto printing material by direct contact methods.

4. In a process for producing a reflex copy, the steps which comprise placing a light-sensitive transparent material sensitized by means of a para-amino-diazo compound and an alkyl phenol which contains only one phenolic hydroxyl group and carries in the alkyl group a substituent selected from the group consisting of the hydroxyl-, carboxyl-, sulfo and amino groups upon the original which is tobe copied, causing light to fall upon the original through the said lightsensitive transparent material developing the image thereon" and reproducing the developed image on a diazo-photo printing material by direct contact methods.

5. In a process for producing ajreflex copy,

the steps which comprise placing a light-sensitive transparent material sensitized by means of a para-amino diazo compound and a 1.4-dimethyl- 2-hydroxybenzene compound which contains only one phenolic hydroxyl group and a methyl group carrying a substituent selected from the group consisting of the hydroxyl-, carboxyl-, sulfoand amino groups upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive transparent material developing the image thereon and reproducing the developed image on a diazophoto printing material by direct contact methods.

6. In a process for producing a. reflex copy, the steps which comprise placing a light-sensitive transparent material sensitized by means of a secondary para-amino diazo compound and an alkyl phenol which contains only one phenolic hydroxyl group and carries in the alkyl group a substituent selected from the group consisting of the hydroxyl-, carboxyle, sulfoand amino groups upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive transparent material developing the image thereon and reproducing the developed image on a diazo-photo printing material by direct contact methods.

7. In a process for producing a reflex copy, the steps which comprise placing a light-sensitive transparent material sensitized by means of 4-mono-ethyl-amino-3-methyl-1-benzene-diazomum-chloride and an alkyl phenol which contains only one phenolic hydroxyl group upon the original which is to be copied, causing light to fall upon the original through the said lightsensitive transparent material developing the image thereon and reproducing the developed image on a diazo-photo printing material by direct contact methods.

8. In a process for producing a reflex coplh.

the steps which comprise placing a lightsensitive transparent material sensitized by means of 4-mono-ethyl-amino-3-methyl-1-benzene-diazonium-chloride and an alkyl' phenol which contains only one phenolic hydroxyl group and carries in the alkyl group a substituent selected from the group consisting of the hydroxyl-, carboxyl-, sulfoand amino groups upon the said original, causing light to fall upon the original through the said light-sensitive transparent material developing the image thereon and reproducing the developed image on a diazophoto printing material by direct contact methods.

9. In a process for producing a reflex copy, the steps which comprise placing a lights'en'sltive transparent material sensitized by means of 4-mono-ethyl-amino-3-methyl-l-benzene-diazonium-chloride and a 1.4-dimethyl-2- hydroxybenzene compound which contains only one phenolic hydroxyl group and a methyl group carrying a substituent selected from the group consisting of the hydroxyl-, carboxyl-, sulfoand amino groups upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive transparent material developing the image thereon and reprodue-ing the developed image on a diazo-photo printing material by direct contact methods.

10. In a process for producing a reflex copy, the steps which comprise placing a lightsensitive transparent material zene-diamonium-chloride and 2.5-dimethyl-6-wdimethyl-amino-methyl-l-phenol upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive transparent material developing the image thereon and reproducing the developed image on a diazo-photo printing material by direct contact methods.

sensitized by means of 4-mono-ethyl-amino-3-methyl-1-bene diazo compound and an azo component which, on development, yield a yellow to greenish-yellow dye, the chief absorption of which extends over the region of about 3300 A. to about 4400 A. upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive transparent material and a light filtering material developing the image on the light-sensitive transparent material and reproducing the developed image on a diazo photo printing material by direct methods.

12. In a process for producing a reflex copy, the

steps which comprise placing a light-sensitive transparent material sensitized by means of a diazo compound and an azo component which, on development, yield a yellow to greenish-yellow dye, the chief absorption of which extends over the region of about 3300 A. to about 4400 A. upon the original which is to be copied, causing light to fall upon the original through the said light-sensitive transparent material, while interposing between the source of light and said transparent material a sheet treated with an ultra-violet light-absorbing substance, developing the image on the light-sensitive transparent material and reproducing the developed image on a diazo photo printing material by direct methods.

13. In a process for producing a reflex copy, the steps which comprise placing a; light-sensitive transparent material sensitized on one side by means of a diazo compound and an azo com- 11. In a process for producing a reflex copy, the

steps which comprise placing a light-sensitive transparent material sensitized by means of a ponent which, on development, yield a yellow to greenish-yellow dye, the chief absorption of which extends over the region of about 3300 A. to about 4400 A. and treated on'the other side with an ultra-violet light-absorbing substance upon the original which is to be copied the diazo sensitized side contacting the said original, causing light to fall upon the original through the said light-sensitive transparent material, developing the image on the light-sensitive transparent material and reproducing the developed image on a diazo photo printing material by direct methods.

14. In a process for producing a reflex copy, the steps which comprise placing a light-sensitive transparent material sensitized by means of a diazo compound and. an azo component which,

on development, yield a yellow to greenish-yellow dye, the chief absorption of which extends" over the region of about 3300 A. to about 4400 A. and having incorporated in the sensitive layer an ultra-violet light-absorbing substance upon the original which isto be copied, causing light to Za se sitive transparent material, developing the image on the light-sensitive transparent material and reproducing the developed image on a diazo photo, printing material by direct methods.

/ Go'r'rmEB VON POSER.

THEO SCHERER. OSKAR siis.

11 upon the original through the said light--