US2855303A

US2855303A - Photosensitive system

Info

Publication number: US2855303A
Application number: US542479A
Authority: US
Inventors: Chalkley Lyman
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-10-24
Filing date: 1955-10-24
Publication date: 1958-10-07
Anticipated expiration: 1975-10-07

Description

United States Patent PHOTOSENSITIVE SYEiTEM Lyman Cliallrley, Washington, D. C.

No Drawing. Application October 24, 1955 Serial No. 542,479

28 Claims. (CI. 96-90) The present application relates to a photochemical process and product and, more particularly, to a photosensitive system based on a combination of a hydrophilic dye cyanide with a hydrocolloid.

It has long been known that the triphenylmethane dyes, which are triphenylmethane derivatives containing at least one auxochromic group, such as the amino or hydroxyl, para to the central methane carbon atom, form leuco cyanides which in the presence of certain activators become photosensitive to ultraviolet and shorter wave lengths of light to produce colored compounds but which are not sensitive to light in the visible range. Because of this property, the substances may be used in photographic and photoduplication processes to print out images that are fully formed without development, that may be permanent and that may be examined in ordinary interior illumination without fixing. The papers employed retain their ultra-violet sensitivity after the printing of one image so that other portions may be printed on at a later date.

Aside from the photographic and photoduplication applications, the colorless dye cyanides are particularly valuable in the recording and measurement of ultra-violet radiation which has generally involved the use of expensive equipment to isolate this region, such as quartz spectrographs and photoelectric meters. Using the triphenylmethane dye cyanides, there can be prepared photosensitive papers that respond only to the shorter Wave ultraviolet and thus provide materials for recording and measuring this region with the ease of a photographic printing out process. Suitable base papers may be impregnated with solutions of the dye cyanides in an activator to form sensitized papers which print out fully formed permanent images. Such papers may be readily prepared which are sensitive to 3250 A. and shorter and to 3350 A. and shorter wave lengths but which are quite unaffected by sunlight passing through colorless glass which will screen out the lower Wave lengths of light. Thus there can be formed very inexpensive actinometers for such specialized purposes as measuring the short Wave and ultra-violet output of lamps, the erythemal component of sunlight, and dosages of therapeutic ultra-violet.

Another use for the papers is in recording instruments where a beam of ultraviolet light may be employed to trace a line which is fully Visible behind a window of colorless ultra-violet absorbing glass.

However, all of the known activators for the dye cyanides are organic materials that have an appreciable vapor pressure and tend to evaporate on exposure to air, thus materially reducing the shelf life of the photosensitive material. Also, most of the known activators are liquids or oily solids and since they must be present at the time of exposure to ultra-violet light, they tend to cause diffusion of the image as, it is formed causing it to be less sharp and well defined. Also, these activators tend "ice to promote diffusion of foreign substances, which may be gases in the air, and which may be deleterious, into the photosensitive composition or, on the other hand, the activator, itself, may difiuse from the composition into or onto another material with which it comes in intimate contact.

Accordingly, it is a primary object of the present invention to provide a solid composition including a triphenylmethane dye cyanide of long shelf life which is activated by a non-volatile and solid organic material so as to be sensitive to ultra-violet light.

A further object of the invention is to provide an activated triphenylmethane dye cyanide composition capable of printing out a sharp, permanent image when subjected to ultra-violet light.

Another object of the present invention is to provide an activated triphenylmethane dye cyanide composition sen sitive to ultra-violet light from which there will be no diffusion of the activator.

Still anothercbject of the invention is to provide an activated triphenylmethane dye cyanide composition which is readily applicable as a film on a supporting base.

Another and further object of the invention is to provide a photochemical process which utilizes a composition which accomplishes the foregoing objects.

Other and further objects will be apparent from the following detailed description of the invention.

It has been found that the hydrophilic triphenylmethane dye cyanides of the phenolic and amino types form photosensitive combinations with hydrocolloids. As examples of hydrocolloids which may be employed, there may be mentioned various carbohydrate compounds in the form of hydrocolloids such as cellulose itself (cotton textiles, paper and the like), methyl cellulose, fl-hydroxyethyl cellulose, starch and dextrine; polyhydroxy colloids, such as sorbitol and the various polymers of vinyl alcohol and partially acetylated vinyl alcohol; proteinaceous substances belonging to the classes of albumins and collagens such as egg albumin, gelatine and the various animal glues; and plant gums such as agar-agar, gum arabic, gum tragacanth, karaya gum, pectins and algin.

The triphenylmethane dye cyanides in which at least one hydroxy group serves as the auxochromic group in the position para to the central methane carbon atom are hydrophilic in nature because of the hydrophilic character of the hydroxyl group and they may contain other hydrophilic groups, such as the sulfonic acid group. Thus dye cyanides of this type will form photosensitive combinations with a hydrocolloid. Many of the phenolic dyes, however, sufit'er from the disadvantage that they form deeply colored compounds only at relatively high pI-Is. However, by including in the photosensitive composition containing a hydrocolloid, basic compounds such as, for example, an ethanolamine or a quaternary ammonium base, which will assure the required basicity, a photosensitive composition which will print out sharp, clear, deeply colored images can be obtained, although the images may not be permanent because of the tendency of the basic compound to react with acidic gases in the air.

The cyanides of the amino triphenylmethane dyes, however, fall into two general classes, hydrophobic and hydrophilic dye cyanides. The hydrophobic dye cyanides are water repellent and very little soluble in water and they are not activated by water so as to be sensitive to ultra-violet light.

An example of a hydrophobic dye cyanide in which the auxochrornic group is an amino function is 4,4,4"-

3 tris-dimethylaminotriphenylacetonitrile, the hydrophobic dye cyanide of crystal violet, having the formula IIKCHah N(CH:)2 va- 3):

By the further addition of a hydrophilic group, such as the sulfonic acid, quaternary ammonium or hydroxyl group to the molecule, the hydrophobic dye cyanides are converted to those whichare hydrophilic in character without destroying their potential photosensitivity to light in the ultra-violet and they have been found to form photosensitive combinations with hydrocolloids.

In my copending applications, Serial Nos. 494,270, now abandoned, and 494,271, now PatentNumber 2,839,- 542, both filed March 14, 1955, I have disclosed amino triphenylmethane dye cyanides which are hydrophilic in nature. In the instant application, there will be disclosed additional examples of such compounds along with processes for their manufacture. These hydrophilic dye cyanides, without exception, form photosensitive combinations with the hydrocolloids.

As stated earlier, the sulfonic acid group is one of the groups which may be substituted in a hydrophobic amino triphenylmethane dye cyanide to render it hydrophilic. This group may be attached directly to a carbon atom of one of the benzene rings of the triphenylacetonitrile compound and this may readily be accomplished by any of the conventional sulfonation techniques. On the other hand, the sulfonic acid group may be associated with one of the amino nitrogen atoms in the para position and this last mentioned substitution may conveniently be effected by the addition to a para-amino group of a suitable sulfonated aryl group such as a phenyl, benzyl or naphthyl group.

The number .of sulfoni'c acidgroups in the molecule of hydrophilic dye cyanide is .not critical and there may be one or more, andthe sulfonic acid groups may be present as free sulfonic acid groups or as water soluble salts, such as, for example, the salts of the alkali and alkaline earth metals.

When ahydroxyl group is that which imparts a hydrophilic character to an amino triphenyla'cetonitrile, it may conveniently be introduced in the form of an alkanol group attached to an amino nitrogen atom. The alkyl portion of the group may bean ethyl or a propyl radical, the propyl radical being either primary or secondary. The alkanol group may be introduced by reacting the amino triphe nylacetonitrile with a conventional fi-hydroxy-alkylating agent such as an alkylene chlorohydrine or alkylene oxide.

The hydroxyl group which imparts a hydrophilic character to an amino triphenylacetonitrile may also be a substituent on an aryl nucleus, for example, one of the phenyl groups attached to the central methane carbon atom.

With respect to the employment of a quaternary ammonium group :as the hydrophilizing substituent, this group may conveniently be derived from one of the para amino groups of the dye cyanide although it will be obvious that, if desired, other .means may be'employed for its introduction. It may be represented by the formula in which R, R and R are each an alkyl group such as methyl, ethyl, propyl, butyl or benzyl and may be the same or different and X is an anion such as a halide, sulphate, acetate, propionate, oxalate, p-toluene sulfonate, benzene sulfonate, sulfamate and perchlorate. The benzyl group listed is, of course, an aryl substituted alkyl group but it behaves in most respects like an alkyl group and may be classed therewith.

The quaternary ammonium group may conveniently be formed by the action of conventional alkylating agents such as an alkyl halide on an amino triphenylmethane dye cyanide.

It will be understood, of course, that more than one type of hydrophilic group may be present in the same molecule of dye cyanide. An example of such a compound is patent blue V cyanide, the cyanide of the dye having Colour Index No. 712, which contains both sulfonic acid groups and a hydroxyl group. This dye cyanide provides an excellent photosensitive composition when combined with a hydrocolloid.

The method of combining the hydrophilic dye cyanide with the hydrocolloid is not critical. It is only necessary that the dye cyanide, preferably in solution, be brought into intimate contact with the hydrophilic colloid. When the colloid is in a solid state, it may be wet with a solution of the hydrophilic dye cyanide as by immersion therein with the excess of solution being removed in any convenient manner and the remaining solvent volatilized. This method is particularly suitable forthe preparation of a photosensitive product employing an absorptive cellulose sheet, such as paper or a cotton textile. The dried product will be found to be photosensitive to ultraviolet and Roentgen rays. The dried cellulose sheet will, after exposure, print out clear, sharp images.

Another convenient method of forming the photosensitive combination-is to admix a solution of the hydrophilic dye cyanide with a hydrocolloid which is also dissolved or-dispersed in a suitable solvent. Water may be used as the solvent if the-dye cyanide is sufficiently water soluble to permit an intimate admixture with a solution of hydrocolloid. Also, various volatile organic solvents, for instance, methyl alcohol, ethyl alcohol, propyl alcohol, i-propyl alcohol and acetonitrile, may be used alone or mixed withwater, as the solventfor the hydrophilic dye cyanide.

The liquid mixture so formed may then be used to coat any suitable base or support and preferably one having a smooth, planar surface. As examples of such supports may be mentioned glass, metal or plastic sheets. The volatile solvent is then driven off leaving the photosensitive dye cyanide-hydrocolloid combination as a tightly adherent film.

This procedure .lends itself excellently to the preparation of coated materials which have a number of important uses, for example, coated glass plates may be used for the'preparation of lantern slides and other transparencies which can be projected or examined by visible light without any fixing process and without destroying the ultra-violet photosensitivity. Likewise, cellulose acetate and similar films may be coated to make transparent photosensitive materials.

Papers may also be coated, and, for example, Baryta coated photographic raw stock, when coated with a photosensitive film, affords an opaque photosensitive sheet that gives ajmaximuni of contrast" and resolution as compared with water leaf paper which is sensitized by a simple combination with agdye cyanide alone. In general, cellulose sheet materials which are heavily coated or sized should be processed by the coating technique rather than impregnated with the dye cyanide alone. For instance, if a hydrophilic dye cyanide, alone, is applied in solution to Bristol board, there 'is imparted only a light and irregular sensitization.

For the coating operations, it is generally desirable to choose ahydrocolloid-such as gelatine, polyvinyl alcohol,

to a smooth, transparent, uniform film, rather than a hydrocolloid which dries to a rough or translucent film,

such as methylcellulose, karaya gum or carboxymethyl cellulose. The hydrocolloid-dye cyanide combination is capable of giving films of extremely high resolution so that images will show microscopic detail. These films have no grain like a silver emulsion, and are transparent and uniform under a microscope. The images formed have the property of being as sharp as the beam of light producing the image. Where the image is projected by a lens or other focusing device, maximum resolution is obtained by making the photosensitive film very thin so that it may be placed at the exact focus at which the image is formed and thus hold to a minimum the sidewise difiusion of the image as the light passes through the film.

The relative proportion of hydrophilic dye cyanide to hydrocolloid in the photosensitive combination is not critical and mustnecessan'ly vary widely in accordance with such factors as the nature of the dye cyanide, itself, the viscosity of the colloidal material employed in pre= paring the combination and thethickness of the dried films. In general, the amount of dye cyanide should be kept as low as possible consonant with the formation of clear, deeply colored images. In most instances, the proportion of hydrophilic dye cyanide will fall within the range of 0.1 to 10.0% based on the weight of the photosensitive combination of the cyanide with solid hydrocolloid. I

Expressing the amount of colorless dye cyanide in terms of the exposable surface area of the photosensitive product, whether it be a coated product or one formed by treating a hydrocolloid in solid form with a hydrophilic dye cyanide, alone, it has been found that there may be from .01 to mgms. of dye cyanide per square inch of surface. A preferred range may be given as .05 to 1.0 mgm.

The following examples in which the Colour Index Number of the parent dye is given wherever possible are set forth as being illustrative, but not as limiting the present invention.

Example 1 0.1 gram of ethyl green cyanide having the formula Color Index No. 685

and prepared as disclosed in my pending U. S. application Serial No. 494,271, filed March 14, 1955, is dissolved in 25 ml. of water and mixed at 50 C. with 25 ml. of a 10% aqueous solution of gelatine. The mixture is cooled to 35 C. and poured onto level glass plates, using.

Example 2 Pure white cotton broadcloth is wet with a 1% solution of ethyl green cyanide, squeezed between rubber rollers (such as a clothes wringer) and dried in the dark. The dry cloth is exposed behind a stencil to ultraviolet of wave length shorter than 3350 A. to print algteeii design on the 'eolo'rless cloth background.

Example 3 7 Equal volumes of a 1% aqueous solution of ethyl green cyanide and a 10% aqueous solution of polyvinyl alcohol (El'vanol 72-51) are heated to C. and mixed. The solution is cooled to 18 C and coated onto white Bristol board, which is dried in the dark. The dry coated Bristol board may be printed on by ultraviolet of wave length shorter than 3350 A. to produce a positive image from a negative.

Example 4 Example 5 A 5% aqueous solution of agar-agar is substituted for the 10% corn starch solution used in Example 4 to produce a photosensitive agar-agar pigment.

Example 6 A solution of 10 g. of white dextrine and 1 g. of ethyl green cyanide is spray dried to give a colorless photosensitive pigment that becomes green on exposure to ultra-violet of wavelength shorter than 3350 A.

Example 7 One gram of patent blue V cyanide, having the formula Color Index No. 712

and prepared as disclosed in my oopending application Serial No. 494,270, filed March 14, 1955, is dissolved in ml. of water. One volume of this solution is mixed at 50 C. with 1 volume of 10% aqueous solution of gelatine. The combined solution is used to coat glass, paper or other materials, which are dried in the dark to form photosensitive printing materials that give a strong blue image on exposure to ultra-violet.

Example 8 The sodium salt of Helvetia green cyanide having the formula ona some om com Index no. see

is prepared by adding to 35 g. of chlorosulfonic acidslowly with stirring at room temperature g. of powdered 4,4-bis-dimethylamino-triphenylacetonitrile. The resulting clear solution is heated slowly in a 250 ml. flask to 85 C. and heldat that temperature until the vigorous evolution of gas subsides. The solution is then heated to 100 C. for 10 minutes, cooled, poured onto 180 g. of cracked ice, the resulting solution filtered and the filtrate treated with a solution of 40g. of sodium hydroxide in 750 ml. of water. 7 The resulting mixture is allowed to stand at C. for 24 hours and the precipitate collected on a filter and air dried. About 12 g. of crude Helvetia green cyanide sodium salt is thus obtained. The crude product is recrystallized from 1% aqueous sodium chloride solution.

One volume of a warm (50 C.) aqueous solution of the sodium salt of Helvetia green cyanide is mixed with one volume of a cold C.) aqueous solution of egg albumen and the mixture used to coat Bristol board, which is dried in the dark. The coated paper prints a green image on exposure to ultra-violet,

Example 9 4,4',4-tris-di-;8 hydroxy ethylaminotriphenylacetonitrile having the formula 7 (JAN is prepared as follows: Five g. of 4,4',4" triamino-triphenagain refluxed for /2 hour in 100 ml. of ethylene chloro hydrine, which is then distilled off as before. The residue is taken up in water andprecipitated with sodium carbonate as before. dried. It-contains a major proportion of the compound of the'above'formula but also some of the tetraand penta-B-hydroxyethyl-triamino-triphenylacetonitriles.

Two tenths of a gram of 4,4,4"-tris-di-5-hydroxy ethylaminotriphenylacetonitrile dissolved in ml. of 91% ipropyl alcohol is mixed at 25 C. with 1 volume of a 10% aqueous solution of methyl cellulose (Methocel NF, viscosity l5 cps. grade). Glass plates are coated with the resulting solution, using 1 ml. of solution to two square inches of glass surface, and the plates are dried in the dark. The colorless film is clear but reticulated, which gives a diffuse optical eflFect desirable for some purposes. Exposure to ultra-violet of wave lengths shorter than 3250 A. yields a bluish violet image.

Example 10 In a preparation carried out as in Example 9, fi-hydroxy-ethyl-cellulose (Cellosize WP-09) I is substituted for the methyl cellulose. The resulting film is smooth and has a high resolving power when printed upon.

. Example 11 The disodium salt of formyl violet S4B cyanide having the formula The final product is collected and Color Index No. 698

is prepared as follows: A solution of 25 g. of Acid Violet 4BNS Ex. Conc., the Ciba Company brand of Formyl Violet S4B, Colour Index No. 698, in 350 ml. of boiling water is filtered from a slight impurity, cooled to 38 C. and treated with a solution of 2.6 g. of sodium cyanide in 15 ml. of water. The following operations are carried out by yellow light such as the illumination from a Kodak OA safelight. The solution is cooled to 25 C. and allowed to stand in the dark for 24 hours, during which time a colorless precipitate forms. The solution is filtered from the precipitate, which is sucked as dry as possible on the filter and air dried to yield about 7 g. of the disodium salt of the compound.

A solution of 0.5 g. of the disodium salt offormyl violet S4B cyanide in 250 ml. of water at 25 C. is mixed with 250 ml. of an aqueous 10% gelatine solution at 75 C., and glass plates are coated with this solution, using 0.5 ml. of solution per square inch of glass plate. On drying in the dark the films are colorless and transparent. They give permanent, grainless, violet images on exposure to wave lengths shorter than about 3300 A.

Example 12 Guinea green cyanide free acid having the formula CZH5 H CzHs Color Index No. 666

is prepared as follows: A solution of 25 g. of commercial Acid Green, Ex. Conc., the Ciba Company brand of Guinea Green B, Colour Index No. 666, in 250 ml. of boiling water is cooled to 40 C., filtered, and treated in yellow light, such as the illumination from a Kodak OA safelight, with a solution of 2 g. of 95% sodium cyanide in 15 ml. of water. The following operations are also carried out in yellow light. The solution is allowed to stand in the dark at 25 C. for 24 hours and then treated in a good hood with 9 ml. of concentrated hydrochloric acid to precipitate the free acid of the dye cyanide.

After the mixture has stood for another 30 hours in the dark at 25 C. the dark brown precipitate is collected on a filter, sucked as dry as possible, and air dried at room temperature to an amorphous mass, weighing about 14 g. This is purified by solution in 15 times its Weight of boiling water, filtration of the hot solution, cooling, standing for 1 week and collection of the newly formed precipitate. 3 This precipitate also is dried at room temperature.

One gram of guinea green cyanide free acid, is dissolved at room temperature by stirring in a mixture of 13 ml. of normal sodium carbonate solution and 37 ml. of water. This solution is mixed with ml. of 10% gelatine solution at 50 C. and 50 ml. of i-propyl alcohol at 9 25 C. Twenty-four pound water leaf paper is impregnated by dipping in this solution and dried in the dark. It prints a permanent green image on exposure to ultraviolet.

Example 13' Tri-fi-hydroxyethyl-p-rosaniline cyanide having the formula andfiltered hot again from the newly formed calcium sulfate. The filtrate is further evaporated to '55 ml. filtered hot from calcium sulfate and the filtrate cooled and allowed to stand in the dark at C. for 24 hours. The precipitated calcium salt of acid fuchsine cyanide is collected on a 'filter, pressed between dry filter papers to remove mother liquor, and dried in vacuo over sulfuric is prepared as follows: A solution of 5 g. of 4,4',4"-triamino-triphenylacetonitrile in 100 ml. of ethylenechlorohydrine is boiled under a reflux condenser for /2 hour in yellow light, such as illumination from a Kodak 0A safelight. This illumination is continued through the rest of the preparation. After the refluxing, 80 to 85 ml. of the ethylenechlorohydrine is distilled off. The residue in the still is dissolved in 100 ml. of water and treated with a solution of 10 g. of sodium carbonate monohydrate in 50 ml. of water, whereupon the hydroxyethylated prosaniline cyanide is precipitated as an amorphous mass. This is washed with 50 ml. of water and air dried or dried in vacuo over sulfuric acid. The dry material is little sensitive to radiation. It is primarily tri-p-hydroxyethyl-p-rosaniline cyanide.

Five ml. of a 1% solution of tri-fi-hydroxyethyl-prosaniline cyanide in 9.1% i-propyl alcohol is added to a mixture of 10 ml. of 10% aqueous gelatine and 5 m1. of 91% i-propyl alcohol, all solutions being at 35 C. and the mixture stirred to uniformity. Water leaf paper is impregnated by dipping and dried in the dark. It prints out a reddish violet image on exposure to wave lengths shorter than about 3250 A.

Example 14 of one form some N Color Index No. 692

is prepared as follows: Fifty ml. of fuming sulfuric acid, 60% S0 is put in a flask equipped with a strong stirrer and a thermometer. Ten g. of finely powdered 4,4',4"- triamino-triphenyla-cetonitrile is added very slowly to the stirred acid, the initial temperature of both reagents being 25 C. Heat is evolved by the reaction, and the addition of the nitrile is controlled so that the temperature of the mixture in the flask does not rise above 60 C. When all of the nitrile has been. added stirring is continued for /2 hour, and the mixture is then poured onto 300 g. of powdered ice. The resulting solution is filtered from a little tar, boiled with activated charcoal, filtered, and the filtrate neutralized by addition of excess calcium carbonate suspended in 1 liter of water. From the time of neutralization operations are carried out by yellow light, such as the illumination from a Kodak 0A safelight. The solution is heated to boiling, filtered from the precipitated calcium sulfate and, excess calcium carlaonate, the filtrate evaporated to a volume of 150 ml.

'acid. The yield is about 8 grams.

A solution of 0.4 g. of acid fuchsine cyanide calcium salt in 10 ml. of water is mixed with 20 ml. of 91% i-propyl alcohol and 12 ml. of 10% aqueous gelatine solution, all of the components being at 40 C. Glass plates are coated using 0.5 ml. of solution per square inch of surface, and dried in the dark. The colorless films print out a red, grainless image on exposure to ultra-violet.

Example 15 Patent blue V cyanide calcium salt having the formula VN-( r t)n s\ (C2Hb)2 Color Index No. 712

it is treated with 40 ml. of a 49% aqueous solution of sodium acetate trihydrate, allowed to stand for 3 days and the disodium salt collected on a filter and washed with 91% isopropyl alcohol (25 ml.) and air dried.

The free acid form is prepared by treatment of a solution of 11 g. of the disodium salt in ml. of water with 12.2 ml. of concentrated hydrochloric acid. After the mixture has stood at room temperature for Zdays, the colorless precipitated free acid is collected on a filter, washed with water, and air dried.

The calcium salt is prepared by neutralization of a hot V2 of 1% aqueous solution of the free acid to pH 8.4 with saturated calcium hydroxide solution. The neutralized solution is cooled to room temperature, allowed to stand for 3 days, and filtered from the colorless, crystalline calcium salt. 7

A solution of 0.6 g. of patent blue V cyanide calcium salt in 60 ml. of wateris mixed with 60 ml. of 10%v aqueous gelatine solution, both solutions being at 50 C. Glass plates are coated at 35 C., using 0.75 ml. of solution per square inch of glass surface, and dried in the dark. The colorless film prints out a permanent blue image on exposure to wave lengths shorter than 3650 A.

Example 16 Malachite green cyanide iodoethylate having the formula mom motion When the solution has been saturated Il. trile) in 50 ml. of benzeneand 1.64 g. of ethyl iodide is placed in a tightly closedflask and allowed to stand in the dark at' room temperature for two years. T he' colorless crystals that formed during this time are collected, washed with benzene, and air dried.

Twenty-four pound water leaf paper is impregnated by dipping in a 1% aqueous solution of malachite green cyanide iodoethylate and dried in the dark. On exposure to wave lengths shorter than about 3200 A. the paper prints out a yellow image, which fades after a few hours storage in the dark, i. e., the paper is phototropic.

Example 17 III-H NSOaS SOaNa Colour Index No. 707, is prepared as follows: A solution of g. of National Aniline Aniline Blue Certified Biological Stain brand of Soluble Blue, Colour Index No. 707, in 75 ml. of boiling water is placed in a pressure bottle with l g. of 95% sodium cyanide, the bottle sealed and heated to 100 for 1 hour in the dark or yellow light, such as the illumination from a Kodak OA safelight. The following operations are also carried out by yellow light. After heating, the bottle is cooled, opened and the solution filtered from a trace of tar. The filtrate is made just acid in a good hood with 64% sulfuric acid and evaporated to dryness in vacuo at 30 C. The residue is dissolved in 50 ml. of water and shaken with 100 ml. of i propyl alcohol, whereupon two layers are formed and separate on standing. The upper alcoholic layer is decanted, the lower aqueous layer extracted with two 20 ml. portions of i-propyl alcohol which are added to thc first alcoholic layer. The alcoholic extract is then evaporated to dryness, leaving the salt of the dye cyanideas an amorphous glassy material. 7

Pure filter paper, 20 pound weight, is impregnated by dipping in a /2 of 1% aqueous solution of soluble blue cyanide sodium salt, and dried in the dark. On exposure to wavelengths shorter than about 3400 A. the paper prints out a permanent blue image.

7 Example 18 The free acid of fast acid violet 10B cyanide having the Color Index No. 696, is prepared as follows: A solution of 25 g. of commercial Fast Acid Violet 10B, Colour lndex No. 696, in the form of Kiton Fast Violet 10B, manufactured by the Ciba Company, in 150 ml. of water heated to C. is placed in a glass pressure bottle. -To- 7.5

20 ml. of boiling 99% i-propyl alcohol.

12 the bottle is added a solution 'of 2 g. of sodium cyanide in 10 ml. of water. The bottle is sealed and heated at C. for 3 hours. T It is transferred to a dark place, allowed to cool and to stand at 25 C. for 24 hours. In light from a yellow safelight, such as Kodak safelight 0A, the bottle is opened, the precipitate collected on a filter and dried without Washing. This precipitate'is the disodium salt.

The free acid is obtained by treating a solution of 5 g. of the disodium salt in 70 ml. of water at 50 C. with 6.5 ml. of 2 N hydrochloric acid. This work is carried out by yellow light. The resulting solution is allowed to stand in the dark at room temperature for 4 days, the precipitate collected on a filter, washed with 20 ml. of cold water, and dried in the dark.

One-half gram of fast acid violet 10B cyanide free acid is dissolved by warming to 60 C. in a mixture of 8.35 ml. of N/ 10 sodium carbonate solution made up to 25 ml. with water. This solution is cooled to 50 C. and mixed with 50 ml. of 10% aqueous gelatin solution at the same temperature. Twenty-five ml. of 91% i-propyl alcohol at 50 C. is immediately added with mixing, whereupon the precipitate initially formed immediately redissolves. This mixture is cooled to 30 C. and coated onto glass plates using 0.75 ml. per square inch of surface. On drying a clear colorless film is formed that prints out a strong, grainless, blue-violet image on exposure to ultra-violet.

Example 19 One-half gram of 4,4,4"-trihydroxy-triphenylacetonitrile, prepared by Caro and Graebe, Berichte der deutschen Chemischen Gesellschaft 11, 1116, is dissolved in One g. of triethanolarnine is added to this solution, which is cooled to 40 C. and stirred into 200 ml. of a 5% aqueous suspension of low viscosity carboxymethylcellulose sodium salt (e. g. Hercules Cellulose Gum Type 70 Low). When the mixture is homogeneous it is coated onto glass plates, using approximately 0.5 ml. per square inch of surface. The plates are dried in the dark to yield uniform translucent films that print out a strong red image on exposure to ultra-violet.

Example 20 Xylene blue VS cyanide disodium salt having the formula PI-(02115): SOaNa N-( 2 5)z QSOaNB. C

C JN

Color Index No. 672

' 13 using about 0.75 ml. per square inch of surface. The plates dry to give clear colorless films that, print out grainless cyan images on exposure to-ultra-violet. of wave lengths longer than about 3500 A.

Example 21 Xylene blue AS cyanide disodium salt having the formula Color' Index No. 673 is prepared as described. in my copending application, Serial No. 494,270, filed March 14, 1955.

One-half gram of xylene blue AS cyanide disodium salt is dissolved at 50 C. in 10 ml. of water and the solution well stirred into 400 ml. of a 3% suspension of powdered karaya gum in water at 50 C. The mixture is spread on glass plates, using about 1 ml. per square inch, and dries to a rather rough translucent film which prints out a cyan image on exposure to ultra-violet of wave length shorter than 3500 A. This preparation prints more slowly and requires greater exposure than the previous examples. Thus it is useful for actinometry where larger quantities of radiation are to be measured.

Example 22 Eriogaucine cyanide tripotassium salt having the formula r a l r Q- $03K $62K -SO3K i ON Color Index No. 671

is prepared as follows: Twenty-five g. of Kiton pure Blue L, the Ciba Company brand of Erioglaucine, Color Index No. 671, is put in a pressure bottle with 150 ml. of boiling water. The dye dissolves immediately. The solution is cooled to 80 C. and a solution of 3.4 g. of 95% sodium cyanide in' 'ml. of water is added, the bottle sealed immediately and heated for 1 hour at 100 C. The following operations are carried out by yellow light, such as the illumination from a Kodak 0A safelight.

After heating the bottle is cooled to room temperature, opened, and the solution filtered from a trace of impurity, treated in a good 'hood with 6.5 ml. of concentrated hydrochloric acid and, evaporated in vacuo at about 50 C. to a volume of 60 ml. The acidity of the somewhat viscous solution is adjusted with sodium hydroxide to pH 6.8. A solution of 22 g. of potassium chloride in 75 ml. of boiling water is then added and the resulting solution allowed to stand in the dark for a week with occasional stirring and scraping of the vessel walls to accelerate the very slow crystallization of the potassium salt. The precipitate is collected on a filter, washed with 25 ml. of aqueous 10% potassium chloride solution, sucked as dry as possible on the filter and dried in vacuo over sulfuric acid. The yield is about g. of nearly 14 colorless material. A second crop, though containing more dye, may be obtained by the addition of 22 g. more of potassium chloride to the mother liquor.

One-half gram of erioglaucine cyanide potassium salt, is dissolved in 20 ml. of boiling Water and the solution stirred into 360 g. of a 3% aqueous sodium alginate solution at room temperature. The homogeneous SOlll tion is coated by spreading onto glass plates, using about 1 g. per square inch of surface, and dried in the dark. The resulting clear, colorless film prints out a grainless cyan image on exposure to ultra-violet of wave length shorter than about 330.0 A.

In the foregoing examples, it will be understood that where not expressly stated, the preparation of the dye cyanides and photosensitive systems should be carried out in light from which ultra-violet has been screened.

I claim:

1. A solid composition comprising a combination photosensitive only to ultraviolet and shorter Wave lengths consisting of a hydrocolloid and a. hydrophilic triphenylacetonitrile compound having at least one radical selected from the group consisting of hydroxy and amino radicals at a position para to the central methane carbon atom.

2. A solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom.

3. A solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom, said compound having in the molecule at least one radical selected from the group consisting of a sulfonic acid radical and its Water soluble salts.

4. The photosensitive composition of claim 3 in which said radical is attached to an aryl nucleus.

5. The photosensitive composition of claim 4 in which said aryl nucleus is attached to said central methane carbon atom.

6. The photosensitive composition of claim 4 in which said aryl nucleus is a constituent of an aralkyl radical attached to a para amino nitrogen atom.

7. A solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a compound selected from the group consisting of fast acid violet 10B cyanide and its water soluble salts.

8 A solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a compound selected from the group consisting of Helvetia green cyanide and its water soluble salts.

9. A. solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a compound selected from the group consisting of acid fuchsine cyanide and its water soluble salts.

10. A solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom, said compound having at least one hydroxyl group in the molecule.

ll. The photosensitive composition of claim 10 in which said hydroxyl group is part of an alkanol group attached to an amino nitrogen atom.

12. The photosensitive composition of claim 11 in which said alkanol group is the ethanol group.

13. The photosensitive composition of claim 11 in which said alkanol group is a propanol group.

14. The photosensitive composition of claim 10 in 15 which said hydroxyl groupis attached to an aryl nucleus.

15. A solid composition photosensitive only to ultraviolet and shorter wave lengths, comprising a combination of a hydrocolloid and a hydroxyethylated p-rosaniline cyanide. i

16. A solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom, said compound having at least one quaternary ammonium group represented by the formula in which R, R and R are each an alkyl group and X isananion. a

17. A solid composition comprising a combination photosensitive only to ultraviolet and shorter Wave lengths consisting of a hydrocolloid and ethyl green cyanide.

18. A product of manufacture comprising a base sheet coated with a solid composition, said composition comprising a combination photosensitive only to ultraviolet and shorter Wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one radical selected from the group consisting of hydroxy and amino radicals at a position para to the central methane carbon atom.

19. A product of manufacture comprising a base sheet coated with a solid composition, said composition comprising a combination photosensitive only to ultraviolet and shorter Wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom, said compound having in the molecule at least one radical selected fromthe group consisting of a sulfonic acid radical and its water soluble salts.

20. A product of manufacture comprising a base sheet coated with a solid composition, said composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrilecompound having at least one amino group at a position para to the central methane carbon atom, said compound having at least one hydroxyl group in the molecule.

21. A product of manufacture comprising a base sheet coated with a solid composition, saidcomposition comprising a combination photosensitive only to ultraviolet and shorter Wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom, said compound having at least one quaternary ammonium group represented by the formula -1 IR 1I1 R1 in which R, R and R are each an alkyl group and X is an anion.

22. A photochemical process comprising exposing to ultra-violet light to produce a colored compound, a solid composition including a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile com- 16 pound having at least one radical selected from the group consisting of hydroxy and amino radicals at a position para to the central methane carbon atom.

23. A photochemical process comprising exposing to ultra-violet light to produce a colored compound, a solid composition including a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom, said compound having in the molecule at least one radical selected from the group consisting of a sulfonic acid radical and its water soluble salts.

24. A photochemical process comprising exposing to ultraviolet light to produce a colored compound, a solid composition including a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom, said compound having at least one hydroxy group in the molecule.

25. A photochemical process comprising exposing to ultra-violet light to produce a colored compound, a solid composition including a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one amino group at a position para to the central methane carbon atom, said compound having at least one quaternary ammonium group represented by the formula R2 Rl in which R, R and R are each an alkyl group and X is an anion.

26. A solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a hydrophilic triphenylacetonitrile compound having at least one hydroxy group at a position para to the central methane carbon atom.

27. A solid composition comprising a combination photosensitive only to ultraviolet and shorter wave lengths consisting of a hydrocolloid and a compound selected from the group consisting of soluble blue cyanide and its Water-soluble salts.

28. A solid composition comprising a combination photosensitive only to ultraviolet and shorter Wave lengths consisting of a hydrocolloid and a compound selected from the group consisting of patent blue V cyanide and its water-soluble salts.

References Cited in the file of this patent UNITED STATES PATENTS 412,614 Hermann October 1889 2,150,695 Muehler Mar. 14, 1939 2,366,179 Chalkley Jan. 2, 1945 2,441,561 Chalkley May 18, 1949 2,528,496 Chalkley Nov. 7, 1950 OTHER REFERENCES Color Index, 1st ed., January 1924, pub. Society of Dyers and Colourists, Bradford, Yorkshire, Numbers 0 660, 692 and 696.

Claims

1. A SOLID COMPOSITION COMPRISING A COMBINATION PHOTOSENSITIVE ONLY TO ULTRAVIOLET AND SHORTER WAVE LENGTHS CONSISTING OF A HYDROCOLLOID AND A HYDROPHILIC TRIPHENYLACETONITRILE COMPOUND HAVING AT LEAST ONE RADICAL SELECTED FROM THE GROUP CONSISTING OF HYDROXY AND AMINO RADICALS AT A POSITION PARA TO THE CENTRAL METHANE CARBON ATOM.