US3865594A

US3865594A - Light sensitive photographic material

Info

Publication number: US3865594A
Application number: US366288A
Authority: US
Inventors: Walter Gauss; Siegfried Petersen; Erwin Ranz; Wolfgang Himmelmann; Rintelen Harald Von
Original assignee: Agfa Gevaert AG
Current assignee: Agfa Gevaert AG
Priority date: 1972-06-09
Filing date: 1973-06-04
Publication date: 1975-02-11
Anticipated expiration: 1992-02-11
Also published as: DE2228110A1; BE800516A; GB1390471A

Abstract

Colored images or relief images can be produced by exposure of a light-sensitive material having a light-sensitive layer which contains a 2-(1,2,4-triazolyl-(1)-1,4-naphthoquinone which is substituted in the 3-position by a saturated or olefinically unsaturated aliphatic group which is attached to the naphthoquinone ring by an ether oxygen.

Description

United States Patent [1 1 Gauss et al.

[ LIGHT SENSITIVE PHOTOGRAPHIC MATERIAL [75] Inventors: Walter Gauss; Siegfried Petersen,

both of Cologne; Erwin Ranz, Leverkusen; Wolfgang Himmelmann, Opladen; Harald von Rintelen, Leverkusen, all of Germany [73] Assignee: Agfa-Gevaert Aktiengesellschalt,

Leverkusen, Germany 221 Filed: June 4,1973

2] Appl. No.: 366,288

[30] Foreign Application Priority Data June 9, 1972 Germany 2228110 [52] US. Cl 96/84 R, 96/35.], 96/67, 96/85, 96/87 R, 96/90 R, 96/1l5 R, 96/115 P, 204/159.l2, 204/l59.l5, 204/l59.23,

[ Feb. 11, 1975 [51] Int. Cl G03c 1/70, G03c 1/72 [58] Field of Search 96/90, 115 R, H5 P. 84

[56] References Cited UNITED STATES PATENTS l2/l967 Yembrick 96/90 R l/l974 Ranz et al. 96/90 R Primary Examiner-Ronald H. Smith Attorney, Agem, 0r FirmConnolly and Hutz [57] ABSTRACT 11 Claims, N0 Drawings LIGHT SENSITIVE PHOTOGRAPHIC MATERIAL This invention relates to a photographic material which contains a 2-triazolyl-1,4-naphthoquinone as light-sensitive compound for the production of color images or relief images. The invention also relates to 2-thiazolyl-l,4-naphthoquinones and to processes for producing them.

Numerous processes are known in which lightsensitive organic substances are used for producing an image. Some of these processes are based on photo chemical rearrangements or reactions of organic compounds which involve a color change. These photochemical reactions of organic compounds have been described, e.g. in Priiparative organische Photochemie (A. Schonbrg, Springer Verlag 1958) and in Lightsensitive Systems" (J. Kosar, John Wiley and Sons, New York, 1965).

These reactions include. for example, the formation of monomethine dyes by a photolytic reaction in UV light oftrihalomethylene compounds in the presence of aromatic or heterocyclic compounds of such a constitution that their CH ring members are particularly reactive in condensation or diazo coupling reactions.

The previously known systems are only of limited practical use because they are generally not sufficiently sensitive to light.

A certain improvement has been found in the lightsensitive materials described in French Patent Specifi cation No. 1,526,496. These materials contain cyclic imides of arylpolycarboxylic acids in which the imide nitrogen is substituted by olefinically unsaturated linear or cyclic aliphatic groups.

Even the photographic processes using the last mentioned compounds, however, are only of limited importance because the materials are still not sufficiently sensitive to light. Moreover, these cyclic imides of arylpolycarboxlic acids are only soluble in purely organic solvents and are therefore diffieult to use, especially in hydrophilic layers. Moreover, for certain practical purposes it is necessary to use light sensitive materials which on exposure should give rise to a colored image which must have a certain stability but which must be able to be reversibly erased after the information has been gathered so that the material can be used again for recording new images.

The photographic material mentioned above is not suitable for this purpose.

It is among the objects of this invention to provide light-sensitive photographic materials which have a sufficient sensitivity to light and which can be used for producing reversibly erasible colored images or relief images by a rapid and simple process.

A photographic material comprising a light-sensitive layer on a support has now been found which contains a 2-( l,2,4-triazolyl-( l )-l,4-naphthoquinone which is substituted in the 3-position by a saturated or olefinicially unsaturated aliphatic group which is attached to the=naphthoquinone ring by an ether oxygen.

1,4-Naphthoquinone derivatives which have the following formula are preferred:

In the above formula:

R represents a saturated or olefinically unsaturated aliphatic group which contains up to 18 carbon atoms preferably up to 5 carbon atoms;

X represents hydrogen. saturated or olefinically unsaturated aliphatic radical which contains up to l8 carbon atoms and preferably up to 5 carbon atoms. in particular alkyl, halogen, such as chlorine or bromine, carboxyl. esterified carboxyl, sulfonic acid, esterified sulfonic acid, aminosulfonyl, an organic sulfonyl group. in particular alkylsulfonyl. alkoxy, nitro or nitrile, and

n is l or 2. The following compounds have been found to be particularly suitable:

- The invention also relates to 2 (l,Z,4-IflaZOlyI(I) l,4-naphthoquinone derivatives of the above general formula and a process for preparing them.

1,4-naphthoquinone derivatives according to the invention are obtained by reacting 2,3-bis-halogeno-l ,4- naphthoquinones which may if desired be substituted on the benzene ring with 1,2,4-triazole, in the presence of aliphatic alcohols or inert solvents and then treating the resulting 2,3-bis-( l ,2,4-triazolyl-( l )-l ,4- naphthoquinone with the desired aliphatic alcohol.

The process according to the invention is unexpected in that it was previuosly known that 2,3-bis-halogeno- 1,4-naphthoquinones reacted with 1,2,4-triazole in inert solvents such as dimethylsulfoxide to yield the bis-triazolyl-substituted naphthoquinone (see German Offenlegungsschrift No. 21 06 845); it was also known 3 that alkoxy groups in quinones could be substituted by primary or secondary amino groups (see the publication by W. Gauss and S. Petersen, Angewandte Chemie, 70 (1958) 703fAccording to what was known, therefore, it was expected that the reaction of 2,3- dihalogeno-l,4-naphthoquinones with 1,2,4-triazo1e. even in the presence of alcohols, would yield the 2,3- bis-triazolyl compound. Moreover, it could not have been expected that when the last mentioned compound was reacted with alcohols, a triazolyl group would be replaced by an aliphatic ether group.

Fluorine, chlorine, bromine and iodine are all suitable halogen substituents in the bis-halogen-1,4- naphthoquinones used as starting material but chlorine and bromine are preferred.

The following are suitable naphthoquinones:

2,3dichloro-l ,4-naphthoquinone 2,3-dibromo-1,4-naphthoquinone 2,3-dich1oro-6,7-dimethyl-1,4-naphthoquinone 2,3,S-trich1oro-1,4-naphthoquinone 2,3,6-trichloro-1,4-naphthoquinone 2,3 ,5,6-tetrachloro-1 ,4-naphthoquinone 2,3-dichloro-5-nitro-1,4-naphthoquinone and 2,3-dichloro-6-aminosulfonyl-1,4-naphthoquinone.

The following are examples of suitable aliphatic alcohols: methanol, ethanol, propanol, allyl alcohol, isopropanol, butanol, isobutanol, sec.-butanol, tert.-butanol, amyl alcohol, iso-amyl alcohol and hexanol.

Derivatives with the substituent X in the fused benzene ring can be obtained in analogous manner.

Tertiary organic bases such as pyridine, quinoline, triethylamine or diazabicyclooctane are strongly basic catalysts which may in some cases be advantageous for the reaction of the bis-triazolyl-l,4-naphthoquinones.

When both triazole and aliphatic alcohols are used for carrying out the process according to the invention, only 1 mol of 1,2,4-trizole is necessary for 1 mol of the 1,4-naphthoquinone but it is advantageous to use an excess of triazole (preferably 5-10 mol altogether) because the hydrogen halide formed are then removed at the same time. The aliphatic alcohol is also advantageously used in excess so that it can serve as solvent. The reaction temperatures employed may vary within a wide range, namely between -and 180C. The process is preferably carried out at the reflux temperature of the alcohol used, i.e. between 60 and 160C. The reaction time depends on the reactivity of the components and must, be tested in each case by taking samples.

If the process of the present invention is performed in two stages, bis-triazolyl-l,4-naphthoquinone is reacted with an alcohol, if necessary in the presence of a basic catalyst. Here again the alcohol is advantageously used in excess to serve as solvent. The reaction temperatures and reaction times employed are the same as indicated above.

Whichever method is used for carrying out the process, the reaction mixtures are cooled after the reaction so that the products of the process separate, usually in the form of a solid. If they do not separate as a solid, they may be precipitated with water or a suitable organic solvent. They are isolated by suction filtration and purified by redissolving from organic solvents.

The preparation of some of the compounds according to the invention is described in detail below. Other halogenated 1,4-

compounds according to the invention are prepared in analogous manner.

COMPOUND 1 20 g of 2,3-bis-[ l,2,4-triazolyl-( l )]-1,4- naphthoquinone are boiled under reflux in ml of methanol for 7 hours. The resulting solution is cooled to room temperature and 250 ml of water are then added, so that 2-[1,2,4-triazoly1-(l)]-3-methoxy-l.4- naphthoquinone precipitates in the form ofa solid. This is suction flltered, washed with water and left to dry. The crude product (11.7 g) is recrystallized from 30 times its quantity 'of carbon tetrachloride and thereby obtained in a pure form with a melting point of 1 1 15 to 112C. The yield is 9.2 g.

C 1-1 N O (255.23):

Calcd.: Found:

Preparation of the starting material is carried out as described in Example 4 of German Offenlegungsschrift No. 21,06,845.

COMPOUND 2 227 g (1 mol) of 2,3-dich1oro-l,4-naphthoquinone in 2 litres of ethanol and 414 g (6 mol) of 1,2,4-triazole are boiled under reflux for 10 hours. When cold, the solution is poured into 20 litres of water. The reaction product precipitates as a smeary substance which gradually solidifies. It is suction filtered, washed with water and dried over calcium chloride in a vacuum dessicator. The crude compound (181.5 g) is purified by recrystallisation from 8 times its quantity of carbon tetrachloride, giving g of pure 2-[1,2.4-triazolyl-(l )1- 3-ethoxy-1,4-naphthoquinone, m.p. 99.5 to 100C.

C H N O (269.25):

Ca1cd.: C 62.45 H 4.12 N 15.61 0 17.83 Found: 62.5 4.5 15.7 17.3

COMPOUND 3 10 g of 2,3-bis-[ 1,2,4-triazolyl-(l )]-1,4-

Calcd.: Found:

COM POUND 4 Single stage method of preparation:

22.7 g of 2,3-dichloro-l,4-naphthoquinone in m1 of isopropanol and 41.4 g of 1,2,4-triazole are boilded under reflux for hours. The resulting solution is diluted with 1.5 1 of water, stirred until crystallisation is completed, suction filtered and dried in a vacuum dessicator. The crude product (16.9 g) is first recrystallised from 10 times its quantity of isopropanol and then from 12 times its quantity of carbon tetrachloride. The purified 2[1,2,4-triazolyl-(1 )]-3-isopropoxy-1,4- naphthoquinone obtained in this way melts at l00.5 to 101 .5C.

C H, N O (283.28):

Calcd.: C 63.59 H 4.63 N 14.83 0 16.94 Found: 63.1 4.7 14.9 16.5

Two-stage method of preparation 10 g of 2,3-bis[ l ,2,4-triazolyl-( l )]-l ,4-

naphthoquinone and 100 ml of isopropanol are boiled under reflux for 26 hours. Since unchanged starting material is still present in the reaction mixture at the end of this time, 1 ml of pyridine is added and boiling under reflux is continued for a further 32 hours. After cooling of the resulting solution to room temperature, the desired product separates on seeding. 7.2 g of product with a melting point of 975 to 99C is isolated at C. A pure compound with a melting point of 99 to 100C is obtained by crystallisation from carbon tetrachloride. It is identical in all its properties with the product obtained by the single stage method of preparation.

The triazolyl-substituted 1,4-naphthoquinones may be used both for producing photographic color images and for producing photographic relief images by the wash-off relief process. The compounds very rapidly assume a deep color when exposed to light and particularly to UV light so that they can give rise to colored photographic images by a very simple and completely dry process. For this purpose they may, if desired, be used as a dispersion in a layer of binder.

To prepare the photographic material, a light sensitive 1,4-naphthoquinone or a mixture of several such compounds is dissolved or finely divided and applied with or without binder to any support. Positive images are then obtained by exposure to UV light under a negative line or continuous tone original. The substances are applied to the supports in known manner by coating or spraying the solutions or by casting the substances from solutions or suspensions of layer forming natural colloids or synthetic resins such as gelatines, cellulose, cellulose esters, cellulose ethers, polycarbonates, in particular those based on bisphenylolalkanes, polyesters, in particular those based on polyethylene terephthalate, polyamides, polyurethanes and various film-forming polymers or copolymers of olefinically unsaturated monomers such as vinyl chloride, vinylacetate, styrene, olefinically unsaturated carboxylic acids or their esters or other derivatives such as maleic acid anhydride, acrylic acid or methacrylic acid and derivatives thereof.

The concentration of the light sensitive substances in the binder may be varied as desired. The graduation of maximum density can be regulated by varying the concentration or by varying the amount of substance applied. When using binders which swell in water, e.g. gelatin, the pH can be varied within the limits beyond which excessive alteration of the binder, e.g. degradation of gelatin occurs. The substances are preferably used in quantities of 5 to based on the dry layer. Exposure is preferably carried out using light sources which contain UV light and it is therefore also suitable to use direct daylight and sunlight as well as mercury vapour lamps, etc.

The light-sensitive compounds used according to the invention may also be employed as self-supporting layers. The layer binders mentioned above are also suitable for this purpose. The choice of layer binder is in principle not critical and a suitable binder can easily be selected by simple tests from the wide variety of known natural or synthetic hydrophilic or hydrophobic layer forming substances.

The color photographic images obtained by this process are stable at room temperature for up to several months. They can be reversibly bleached by heating to temperatures of between 60 C and 220C. The colored products produced on exposure to light are thus reconverted into the colorless light-sensitive compounds. The optimum temperature of this conversion depends on the nature of the light-sensitive compound and can be easily determined. When heating the image to bleach it, care should be taken not to heat it to a temperature at which irreversible decomposition of the colored compound takes place. This irreversible decomposition may either result in cross-linking or render the binder hydrophobic, depending on the nature of the binder used. This effect is used for the production of relief images as will be described below.

The specific temperature at which reversible bleaching or irreversible decomposition occurs depends on the structure of the Z-triazol-l,4-naphthoquinone and also to some extent on the nature of the binding agent. The optimum temperature for the bleaching or decomposing reaction can he found easily by simple tests customarily in the art.

According to another embodiment of the process, the photographic material of the present invention is used for a photographic process for producing relief images. The preferred photographic material for this purpose comprises a transparent or opaque support to which is applied a layer of dye which will contrast strongly in color with the support. The light-sensitive compound is contained either in this layer or dye or in a separate layer above the dye layer.

For producing relief images, the photographic materials according to the invention are processed as follows:

The material is first exposed imagewise to produce a deep colored image in the exposed areas by photolytic reaction of the 1,4-naphthoquinone. The exposed material is then heated to a temperature of between about and 250C. This heating presumably causes decomposition of the light-sensitive compound, or the groups formed on exposure to light, so that the layer binder is converted into a less soluble form in the exposed parts of the layer. The material is then treated with a solvent for the binder of the layer to wash off the unexposed parts of the layer, which have remained unchanged, to expose the contrasting colored or transparent layer support in these areas. ln the case of a black light-sensitive layer on a support or baryta paper, for example, a deep colored negative image of the original is obtained. Conversely, if a white (cross-linked) layer is used on a dark support, a positive image of the original is obtained by exposure of the colored support in the areas which have not been struck by light.

Many different binders are suitable for the production of relief images. The choice is unexpectedly not restricted to polymers which contain certain reactive groups or groups which can be cross-linked, nor has it yet been explained on what effect the process according to the invention is based, i.e. whether the layer binder is in fact cross-linked by the products produced on heating or whether these products merely affect the hydrophilic character of the layers to such an extent that the unexposed parts of the layer remain soluble while the light struck areas are rendered insoluble in these solvents or incapable of swelling in them.

The wide variety of suitable layer binders also arises from the finding that both water-soluble binders and binders which are soluble in organic solvents such as benzene, acetone, butanol, chloroform, ethylacetate, etc. can be used. Water-soluble binders are, of course, preferred because they simplify the process. Both synthetic and natural film-forming products can be used, e.g. proteins in particular gelatin. Cellulose derivatives such as cellulose ethers or cellulose esters are particularly suitable, e.g. methylor hydroxyethyl cellulose, carboxymethylcellulose or the like. Starch or starch derivatives such as starch ethers, alginic acid or derivatives thereof such as salts, in particular alkali metal salts, esters or amides, carageenates and the like may also be used. Cellulose ethers with short chain alkyl ether groups which are soluble in water are preferred.

The change in physical properties of the layer in areas corresponding to the image can also be achieved with synthetic binders such as polyvinyl alcohol, partly saponified polyvinyl acetate, polyvinyl pyrrolidone or saponified copolymers of polyvinyl acetate, e.g. with ethylene. I

The light-sensitive compounds may either be contained in a separate layer arranged above the layer which contains dye or it may be added to the colored layer. In the first method, the binders used for the colored layer may be the same as or different from those used for the light-sensitive layer. It is, of course, necessary to ensure that the binders for the colored layer are soluble in the same solvents as the binders for the light sensitive layer so that both the light sensitive layer and the colored layer can be washed off in the areas which have not been struck by light to expose the differently colored support.

According to another method, the light sensitive, l,4- naphthoquinones may be applied to the colored layer without the use of a lyer binder.

The supports may be produced from the usual materials, e.g. cellulose esters such as cellulose acetate or cellulose butyrate, polyesters, especially those base on polyethylene glycol, terephthalat'e or polycarbonates, preferably those based on bis-phenylolalkanes, or paper supports may be used, in particular'baryta paper.

The supports may be transparent or colored, preferably with dyes which contrast strongly with the dye layer. If a support with a self colored layer is used, it is,

. of course, necessary to ensure that the binder used for this layer differs sharply in its physical properties and especially in its solubility from the binder used for the dye layer so that the photographic process will not damage this layer of the support. Another important factor is the strength of the bond between the layer of dye or the light-sensitive layer and the support or selfcolored layer of the support. This bond should not be too strong because otherwise the unexposed areas of the light sensitive layer or layer of dye will not be washed off readily. On the other hand, the bond must be sufficiently firm so that the layerswill not separate spontaneously. None of these factors, however, provides any serious difficulties. Suitable combinations of layers and binders for these layers can easily be found with the aid of general methods well known in the art.

There are no restrictions from a chemical point of view as regards the choice of suitable dyes for the support or for the dye layer itself; As already mentioned above, the dye in the dye layer should provide a high contrast with the color of the support. This is necessary in order to obtain a high contrast image. In addition, the dyes should, of course, be insoluble in the various solvents used in order that they will not migrate into adjacent layers or parts of layers. It is, of course, necessary to ensure that the dye in the dye layer will not also color the differently colored support in the course of preparation of the material because otherwise the background will interfere with the image when the parts of the layers which have not been struck by light are washed off to expose the support underneath. The dye in the dye layer in which the relief image is produced may be present either as a solution or as a heterogeneous dispersion. in the latter case, the usual inorganic or organic pigment dyes are suitable. If, on the other hand, the dye is present in a dissolved form in this layer, care must, of course, be taken to ensure that the solvent used for washing off the layer to produce the relief image will not dissolve the dye and thereby impart an unwanted color to the background.

The sensitivity of the materials according to the invention extends from the ultraviolet to the visible part of the spectrum. It is therefore suitable to use light sources such as UV lamps, mercury vapour lamps, halogen lamps, electronic flashes or the like for exposure. The exposure time depends, of course, on such factors as sensitivity of the light sensitive compound, the distance of the source of light from the light sensitive material, etc. Exposure times of between 5 seconds and l2 minutes have generally been found to be sufficient. For-most materials, exposure times of 5 to 20 seconds are sufficent to produce a high contrast image of good quality.

After exposure, the material is heated to a temperature of between and 250C, preferably between and 200C. As already mentioned above in connection with the production of color images, the optimum temperature depends on the light sensitive 1,4- naphthoquinone used. ln the process already described above the production of relief images, the temperature must be sufficiently high to produce irreversible decomposition of the compound in the light struck areas and hence a change in the solubility properties of the layer. Heating may be carried out by various methods, e.g. by keeping the exposed material in a heating cupboard or preferably by passing the exposed material between heated rollers. The time required for the heat treatment depends on the desired effect, the nature of the naphthoquinone and, of course, on the temperature. Longer times are required at lower temperatures and conversely very short times at high temperatures. Heating times of between a few seconds and 1 minute are generally sufficient. At temperatures between and C it isgenerally sufficient to heat for between 5 and l0 seconds. The choice of temperature also enables the sensitivity of the material to be varied within wide limits. The higher the temperature to which the exposed material is heated, the greater will be its sensitivity, ie the lower will be the intensity of light required to achieve sufficient physical differentiation of the layer. Thus, for example, at temperatures of about 200C even parts of the layer which have been only very slightly exposed to light will be changed in their physical properties to such an extent that they can no longer be washed off. Within the temperature range of 80 to 250C, the sensitivity can be varied by a factor of 10 to 50, depending on the nature of the lightsensitive compound.

After the heat treatment, the unexposed parts of the light-sensitive layer or dye layer are washed off. This can be done in the usual manner and with known apparatus by treating the material with a suitable solvent.

As already mentioned above, in the case of watersoluble layer binders, which are the binders preferably used, washing off can be carried out simply with tap water. The treatment time required for the washing off stages also depends on the nature of the layer binder but times of between about seconds and 1 minute are generally sufficient.

According to a particular embodiment of the process of the invention, removal ofthe unexposed parts of the layer may also be carried out by transferring these parts of the layer to a second support. This is carried out by pressing the exposed and if desired moistened layer and a second support together after the exposed layer has been heated. The two sheets are then separated so that the unexposed parts of the light-sensitive layer remain behind on the second support. If this layer was black or dark in color, an image which is the right way round is directly obtained on the second layer support. When this method is employed, the adhesive properties of the layers must be correctly adjusted to each other so that the unexposed parts of the light sensitive layer adhere less firmly to the original support than to the second support. The reverse applies to the exposed parts of the layer. Since such tear-out processes are well known in principle, it will be possible for the average expert to find suitable combinations of binders with the aid of a few simple tests.

In the process according to the invention, exposure may be carried out either with transmitted light behind transparent originals or with the usual reflected light in the case of opaque originals.

With suitable choice of the components, the whole process takes between about 25 seconds and 1 minute.

The material according to the invention and the process according to the invention have considerable advantages over known image-recording processes, particularly those in which light sensitive substances which are free from silver halides are used.

In the case of the last mentioned materials, there is always the problem of stabilising the image because the light sensitive compounds remain behind in the unex posed parts of the layer. In the case of silver halide emulsion layers, the silver halides can be removed from the unexposed parts of the layer by the usual method of fixing with silver halide solvents. In the case of mate rials which are free from silver halides, on the other hand, removal of the light sensitive compounds or their conversion into products which are insensitive to light always entails serious difficulties.

Another advantage is the exceptionally high light fastness of the colored images. Since the choice of dyes or pigments is subject to practically no restrictions, it is possible to use light fast dyes, for example such as those used for textiles. In addition, images can easily be obtained in a very wide variety of colours on any coloured background. With the wide choice of known dyes available, it is possible to obtain any desired combination.

Another advantage is that both positive and negative copies of the original can be obtained using the same principle, depending on the color of the support and of the pigment layer. lf,'for example, a dark colored pigment layer is used on a white support, a negative. dark image is obtained on a light ground since the dark pigment layer is washed off in the unexposed areas. If, on the other hand, a white pigmented layer is used on a dark colored support, a positive image in the color of the dark support is obtained since the exposed areas remain white.

The images obtained by the process according to the invention have a very steep gradation and are primarily suitable for producing copies of line originals.

According to a preferred embodiment of the photographic material for producing relief images, compounds which contain at least one olefinic double bond, or compounds which are capable of forming olefinic double bonds when exposed to light in the pres ence of lightsensitive 1,4-naphthoquinones and which undergo polymerization and cross-linking at room temperature in the presence of the exposed 1,4- naphthoquinones, are added to the light-sensitive layers in order to increase the sensitivity to light and obviate the stage of heating after exposure. Compounds of this kind have been described in German Offenlegungsschrift 21 12 141 or U.S. application Ser. No. 233,753. The compounds may be present in a monomeric or polymer form. Polymerization and/or crosslinking occurs in the presence of 1,4-naphthoquinones which have been exposed to light.

Monomeric compounds of this kind may, if desired, be added together with the light-sensitive compounds to the casting solution for the layer, which also contains the binding agent. If polymeric compounds which contain double bonds or form double bonds on exposure to light are used, the binding agent may be omitted if these compounds themselves have film forming properties.

A. Low molecular weight compounds I) ca e-c041 N Qco-cnLca 00-011 =ca v v III) ca es -S02-Z-S02GR -ca 11 So -CR =Ci-l se -ca =cu v) CH =CR -CO-Z-CO-CR =CH in which:

R stands for hydroxy, alkoxy with preferably up to 5 carbon atoms, in particular methoxy or ethoxy, in particular phenoxy or an amino group which may be substituted with one or more substituents, e.g. with an alkyl group which has preferably up to 5 carbon atoms, in particular methyl or ethyl, anad the alkyl groups may themselves carry substituents, e.g. acyl groups and in particular acyl groups of unsaturated aliphatic carboxylic acids such as acryloyl or methacryloyl;

R" represents hydrogen or alkyl, in particular short chain alkyl with up to 5 carbon atoms such as methyl or ethyl;

Z is any organic bridging group, in particular an aliphatic bridge with up to 6 carbon atoms which may.

be interrupted by hetero atoms, e.g. by oxygen, sulfur, sulfonyl or imino, and the imino group may be substituted, e.g. with alkyl or it may be in the form ofa cyclic imino group as in the case of piperazinyl or hexahydrotriazinyl groups or it may be in the form of an ammonium group; Z may also be an imino group optionally substituted by alkyl or aryl, in particular phenyl, or an ammonium group which may also be in a cyclic form as in the case of piperazinyl or hexahydrotriacenyl or it may represent the group NH-(CH NH. Specific examples are given in the table under Al-A24.

Compounds of the following formulae are examples of suitable monomeric compounds which are capable of forming olefinic double bonds:

VII)

SO -CH -CH y so -ca -crr Y In) If ii co-cim -cn V CO-GHR -CH 12 x1) -CH -CH -S0 Z-SO -CH -CH -y 0 011 CH2 oso x11) s -cH --cu -0so 9 m1 9 CH2 CH oso N8 in which:

Y'is either (I) an amino or ammonium group which may be substituted e.g. with alkyl which contains up to 5 carbon atoms and it may also be in a cyclic form, e.g. in the form of the following groups:

in each case with an anion, the nature of the anion being immaterial in the case of the ammonium groups, suitable anions being, for example, halide anion's, sulfates etc., (ll) a carbalkoxy group, in particular those carbalkoxy groups which can be derived from short chain aliphatic carboxylic acids such as acetic acid or halogenated acetic acids and in particular from chlorinated acetic acids, (lll) halogen such as fluorine, chlorine, bromine or iodine, or (IV) a sulfato group.

Compounds A 25 to A 34 given as examples in the following Table are particularly suitable:

A 1) CH2=CH-C0-NH-COCH=CH2 A 2) on on-004m I CH2=CH-C0-NH A 3) CH2=CH-C0-OC2H5 A 4) CH2=CH-C0NH2 A 5) OH2=CH-C0NH A 6) ca =c(cn )-co-1m A 7) c11 =cc1i -co-mr-t:o--c(oxy en A a) CH2=C(CH3)CO-NHCH2 ,,co-ca -cr1 7 9 ,co-cn -cH -N ca io-cn -ca ir f 16 QE 01 o I vso .-ca -cn +1; 0 c 6 -CH2-GH2-SO2-CH2-CH2- a ,cocrr Q CH2- These compounds are known. Compounds A26 to B. High Molecular weight compounds The olefinic double bonds, or the groups which are capable of forming olefinic double bonds, may also be chemically attached to the binder molecule, e.g. through oxygen or imido groups in the form of esters, acetals or amides. These compounds are obtained by reacting OH or amino groups with acid derivatives which contain C=C double bonds such as acid halides, anhydrides and isocyanates or by reaction with aldehydes. Compounds which have proved to be particularly suitable for this purpose are reaction products of acrylic and methacrylic acid halides with polysaccha- 'rides and in particular with cellulose or starch derivatives such as hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethyl starch, hydroxypropylstarch, alginic acid, hydroxyethylalginic acid, methyl cellulose, carboxymethylcellulose or starch ether or with synthetic polymers which contain hydroxyl or amino groups, such as polyvinyl alcohol, partly saponified polyvinyl acetates, partly or completely saponified copolymers of vinyl acetate-vinyl pyrrolidone, vinyl acetateethylene, vinyl acetate-acrylic acid or vinyl acetatecrotonic acid. B-halogenpropionic acid esters of cellulose ethers which can be converted into the corresponding unsaturated compounds by removal of HCl or maleic acid esters of the above mentioned compounds may also be used.

The compounds are prepared by reacting the corresponding high molecular weight compounds with the corresponding acid halides in suitable solvents such as dioxane or toluene in the presence of acid receptors such as triethylamine and isolating the reaction products. The reaction is carried out in dark rooms. The

compounds are kept in solution with exclusion of light because inthe solid form they readily undergo crosslinking. The corresponding carbamic acid esters and ace-tals can also be prepared by known processes.

The high molecular weight compounds which contain polymerisable groups may be used alone or together with other binders. They may also be used together with the low molecular weight compounds described under (A). g

reprecipitated by the addition of concentrated sodium chloride solution. The residue is again dissolved in water with the addition of acetone and the mixture dialysed for 3 hours.

Yield: 250 g.

B2. Reaction product of hydroxypropylcellulose with 10% by weight of methacryloyl chloride.

200 g of hydroxycellulose are left to swell in 1 l of anhydrous toluene for one hour at room temperature.

22 g of triethylamine are added to the dispersion with stirring and the mixture is then cooled to 10C.

After dropwise addition of 20 g of methacryloyl chloride dissolved in 100 ml of toluene, the mixture is stirred for 12-14 hours at room temperature. The reaction product is then suction filtered and twice suspended in toluene. It is suction filtered and the residue is washed with ether and dried in air. The compound is dissolved in water at 10C and the highly viscous solution is dialysed against tap water for several hours (3-4% solution).

Yield: 190 g.

B3. Reaction product of hydroxypropylcellulose and maleic anhydride 50 g of hydroxypropylcellulose are dissolved in 160 cc of formamide and 300 cc of acetone at 60C with stirring. The solution is cooled to room temperature and 30 g of anhydrous sodium acetate are added. A solution of 30 g of maleic anhydride in 40 cc of formamide are added dropwise in the course of 2 hours at about 30C with cooling. The reaction mixture is then stirred for 17 hours. The reaction product precipitated with acetone and triturated with acetone. After suction filtration, a 5% solution in water is prepared. The low molecular weight constituents are removed by dialysing the solution for several hours.

Yield: 45 g (The solution is 3.2%).

The following compounds B 4 to B 6 are prepared in a similar manner.

B4. Reaction product of hydroxyethylcellulose (e.g. the product marketed under the Trade designation Natrosol 250 MR) and 5% by weight of methacryloyl chloride.

Yield: approx. 90%.

B5. Reaction product of hydroxypropylcellulose and 20% by weight of B -chloropropionyl chloride. Yield: approx 90%.

B6. Reaction product of hydroxyethylcellulose and 5% by weight of cinnamyl chloride Yield: approx. 90%.

B7. Reaction product of hydroxypropylcellulose with 5 by weight of mucochloric acid 1 g of Mucochloric acid in 10 ml of dioxane and 0.5

g of p-toluenesulphonic acid are added to a mixture of g of hydroxypropylcellulose and 500 ml of dioxane at room temperature. The reaction mixture is diluted with water ater 18 hours stirring and then dialysed against tap water for 48 hours.

Yield: 17 g as a 3% aqueous solution.

B8. Reaction product of hydroxypropylcellulose with B-isocyanato-ethyl ester of methacrylic acid.

25 g of hydroxypropylcellulose are introduced into 300 ml of toluene and left to swell for 2 hours.

25 g of fi-isocyanatoethylmethacrylate are then added dropwise with vigorous stirring and the mixture is heated to 50C for 4 hours. It is then cooled and the reaction product is suction filtered and washed with ether.

Yield:.22 g.

B9. Reaction product of hydroxypropylcellulose and ,B-isocyanatoethylmethacrylate in ethylene glycol dimethylether 25 g of hydroxypropylcellulose are dissolved in 300 ml of ethylene glycol dimethyl ether, and 2.5 g of B-isocyanato ethyl methacrylate are then added dropwise to the resulting relatively very viscous solution with constant stirring. The mixture is then heated to 40C for 4 hours. The product is ready for use immediately after cooling.

B10. Reaction product of hydroxpropylcellulose and chloroacetyl chloride in the presence of triethylamme 20 g of hydroxypropylcellulose are left to swell in ml of toluene for 2 ours, 5 ml of triethylamine are added, the reaction mixture is cooled to 10C and 2.66 ml of monochloroacetyl chloride are added dropwise. The reaction mixture is then stirred overnight and the product obtained is suction filtered, washed with ether, dissolved in water and dialysed for 36 hours. The particles formed by swelling are removed and the solution is concentrated to 500 ml. Solids content: 7.55 g (con centration 1.76% by weight).

B1 1. Reaction product of hydroxypropylcellulose and acryloyl chloride 20 g of hydroxypropylcellulose are left to swell in 100 ml of toluene for 2 hours. 2.5 ml of triethylamine are added, the reaction mixture is cooled to 10C and 2 g of acryloyl chloride dissolved in 20 ml of toluene are added dropwise at 10C. The reaction mixture is then stirred for 6 hours, filtered, washed with ether, taken up with 1.2 l of water and dialysed for 36 hours. The particles formed by swelling are removed and the solution is concentrated to a volume of 500 ml by evaporation under vacuum at temperatures below 40C. Solids content: 16.3 g (4.5% solution).

B12. Reaction product of hydroxypropylcellulose and acrolein 20 g of hydroxypropylcellulose are dissolved in 500 ml of dioxane. 2 g of acrolein and a solution of 0.5 g of p-toluenesulphonic acid in 10 ml of dioxane are then added. The mixture is stirred at room temperature for 24 hours and then diluted with water and dialysed against tap water for 48 hours. The dialysate is concentrated to a 4% solution at a temperature of up to 40C.

B13. Reaction product of hydroxypropylcellulose and acrolein Method of preparation the same as for compound (B ll) but using 4% of acrolein.

The effectiveness of the combination of lightsensitive l,4-naphthoquinone, compounds with olefinic double bonds or which are capable of forming double bonds (hereinafter called accelerators) and binder depends, of course, to a certain extent on the choice of suitable components for this combination. The optimum combination for the requirements of any given reproduction process can easily be found by a few simple laboratory tests.

The concentration of components in the layer may vary within wide limits and depends on the requirements of the particular reproduction process. Quantities of 200 to 1,000 mg of light sensitive naphthoquinone per m of material have generally been found to be sufficient. The thickness of the light sensitive layers is approximately between 0.2 and pm. The accelerator compounds are added in proportions by weight of 0.5 to 30%, preferably 5 to based on 1 part by weight of layer binder.

A visible image which can instantly be assessed is immediately formed in the exposed areas on exposure to light.

EXAMPLE 1 'to 180C for 30 seconds. The material can then be used again.

EXAMPLE 2 35 g of a fine paste of carbon black pigment with a pigment content of 35% by weight, e.g. Helioechtschwarz V paster of BAYER AG, are stirred into 250 g of a 3% by weight solution of the high molecular weight compound B in a 1:1 mixture of ethyl alcohol/ethylene glycol monomethyl ether, using a high speed stirrer. 500 ml of a 1:1 solvent mixture ofethyl alcohol and ethylene glycol monomethyl ether are then added and the mixture is cast on a layer support of polyethylene terephthalate. The thickness of the dried layer is 1 1.. A layer of lightsensitive compound 2 which is free from binder and contains about 1 g of substance per m is then applied to the dried pigment layer from a 1.5% solution is chloroform.

The layer is then exposed through a transparent original for 30 seconds as indicated in Example 1. It is then passed through sponge rollers which are moist with water (e.g.'wash-off apparatus TRANSPAREX W 20 of Agfa-Gevaert AG). The unexposed parts of the layer are thereby washed off and a transparent, black positive image of the original is obtained.

EXAMPLE 3 Part A Part B 13 g of the light sensitive compound 4 are dissolved I in 250 ml of ethylene glycol monomethylether, and 250 ml of ethyl alcohol are then added. Part B is then stirred into Part A with vigorous stirring and the mixered with substrate. The thickness of the layer when dry is l/L. 1

The layer is exposed through a transparent negative original for seconds in the manner indicated in Example It is then passed between a pair of rollers together with a moistened baryta paper. The usual apparatus used for producing copies by the silver salt diffusion process,.for example, are suitable for this purpose. When the exposed material and the moist receptor sheet are pressed together, the unexposed parts of the blue pigmented light-sensitive layer adhere to the receptor sheet more firmly than the exposed parts of the layer. On separation of the two sheets, these unexposed parts of the layer are torn out of the light sensitive layer so that a positive relief image of the original is obtained in ablue colour.

EXAMPLE 4 25 g of light sensitive compound 1 are dissolved in 750 ml of ethyl alcohol. 500 g of a 3% by weight solution of hydroxypropylcellulose (e.g. the product marketed by Hercules Powder under the trade designation KLUCEL G) in ethyl alcohol and 500 ml of ethylene glycol monomethyl ether are then added. The solution is cast on a hydrophilic paper support. The thickness of the dry layer is 1.5a.

The layer is exposed through a transparent original for 60 seconds in the manner indicated in Example i. It is then heated to C in a heating cupboard for 1 minute. The layer is then washed off as described in Example 2. lf this layer is used as matrix in an offset printing apparatus, the oil dye is taken up only by the relatively hydrophobic image areas, i.e. the areas which have not been washed off. Satisfactory offset prints are obtained.

We claim:

1. A light-sensitive photographic material containing a supported of self-supported light-sensitive layer which contains a light-sensitive 2-( l ,2,4-triazoly1-( l l,4-naphthoquinone being substituted with a saturated or olefinically unsaturated aliphatic group attached to an ether oxygen atom in the 3-position of the naphthoquinone system.

2. The light-sensitive photographic material of claim 1, wherein the triazolyl-l ,4-naphthoquinone has the following formula:

0 16 l oo =N in which: I I

R stands for a saturated or olefinically unsaturated aliphatic radical which contains up to 18 carbon atoms;

X represents hydrogen, a saturated or olefinically unsaturated aliphatic radical which contains up to 18 carbon atoms, halogen, carboxyl, esterified carboxyl, sulfonic acid, esterified sulfonic acid, aminosulfonyl, an organic sulfonyl group, alkoxy, nitro or nitrile and n is l or 2.

3. The photographic material of claim 2,wherein X 21 represents hydrogen and R represents an alkyl group which contains up to carbon atoms.

4. The photographic material of claim 1, wherein the material contains on a transparent or opaque support a dye layer with a dye whose color contrasts strongly with the support, the light-sensitive l,4- naphthoquinone being contained either in this dye layer or in a separate layer arranged above the dye layer.

5. The light-sensitive photographic material of claim 1, wherein the light-sensitive layer contains compounds which have at least one olefinic double bond or compounds which form olefinic double bonds and which are capable of polymerizing or cross'linking when exposed to light in the presence of l,4-naphthoquinone.

6. The material of claim 5, wherein the compound capable of forming olefinic double bonds is a compound of one of the following formulae Y-ca -cii -so -z-so -ca -ca y ca CH OSO Na in which:

Y (l) an amino or ammonium group (ll) carbalkoxy (Ill) halogen or (IV) sultato.

7. The material of claim 5, wherein the compound having at least one olefinic double bond is a polysaccharide in which the hydroxyl groups are completely or partly substituted with vinyl carbonyl or vinyl sulfonyl groups.

8. The material of claim 5, wherein the compound having at least one olefinic double bond is a vinyl alcohol polymer wherein the units of vinyl alcohol are completely or partly substituted with vinyl carbonyl or vinyl sulfonyl groups.

9. The material of claim 7, wherein the compound containing at least one olefinic double bond is a hydroxyalkylcellulose substituted with acryloyl or methacryloyl groups.

10. A light-sensitive photographic material containing a supported or self-supported light-sensitive layer between 0.2 and 5/m,u in thickness which contains a light-sensitive 2-( l ,2,4triazolyl-( l )-l ,4- naphthoquinone being substituted with a saturated or olefinically unsaturated aliphatic group attached to an ether oxygen atom in the 3-position of the naphthoquinone system, in the amount of between 200 to 1,000 mg per in of the light-sensitive layer.

11. A light-sensitive photographic material containing a supported or self-supported light-sensitive layer which contains a light-sensitive 2-( l ,2,4triazolyl-( l l,4-naphthoquinone being substituted with a saturated or olefinically unsaturated aliphatic group attached to an other oxygen atom in the 3-position of the naphthoquinone system, said naphthoquinone being from 5 to by weight of the light-sensitive layer in dry state.

Claims

1. A LIGHT-SENSITIVE PHOTOGRAPHIC MATERIAL CONTAINING A SUPPORTED OF SELF-SUPPORTED LIGHT-SENSITIVE LAYER WITH CONTAINS A LIGHT-SENSITIVE 2-(1,2,4-TRIAZOLYL-(1)-1,4NAPHTHOQUINONE BEING SUBSTITUTED WITH A SATURATED OR OLEFINICALLY UNSATURATED ALIPHATIC GROUP ATTACHED TO AN ETHER OXYGEN ATOM IN THE 3-POSITION OF THE NAPHTHOQUINONE SYSTEM.

2. The light-sensitive photographic material of claim 1, wherein the triazolyl-1,4-naphthoquinone has the following formula:

3. The photographic material of claim 2,wherein X represents hydrogen and R represents an alkyl group which contains up to 5 carbon atoms.

4. The photographic material of claim 1, wherein the material contains on a transparent or opaque support a dye layer with a dye whose color contrasts strongly with the support, the light-sensitive 1,4-naphthoquinone being contained either in this dye layer or in a separate layer arranged above the dye layer.

5. The light-sensitive photographic material of claim 1, wherein the light-sensitive layer contains compounds which have at least one olefinic double bond or compounds which form olefinic double bonds and which are capable of polymerizing or cross-linking when exposed to light in the presence of 1,4-naphthoquinone.

6. The material of claim 5, wherein the compound capable of forming olefinic double bonds is a compound of one of the following formulae

10. A light-sensitive photographic material containing a supported or self-supported light-sensitive layer between 0.2 and 5/m Mu in thickness which contains a light-sensitive 2-(1,2,4-triazolyl-(1)-1,4-naphthoquinone being substituted with a saturated or olefinically unsaturated aliphatic group attached to an ether oxygen atom in the 3-position of the naphthoquinone system, in the amount of between 200 to 1,000 mg per m2 of the light-sensitive layer.

11. A light-sensitive photographic material containing a supported or self-supported light-sensitive layer which contains a light-sensitive 2-(1,2,4-triazolyl-(1))-1,4-naphthoquinone being substituted with a saturated or olefinically unsaturated aliphatic group attached to an ether oxygen atom in the 3-position of the naphthoquinone system, said naphthoquinone being from 5 to 80% by weight of the light-sensitive layer in dry state.