Claims:
We claim
1. A photosensitive composition for diazo photography comprising in combination a photolytic aromatic diazonium salt and at least one member selected from the group consisting of dithiocarbamates of the formulas I and II, ##SPC32##
2. A photosensitive material composition for diazo photography according to claim 1 in which the photolytic aromatic diazonium salt is a member selected from the group consisting of p-diazo mono (or di-) alkylaniline derivatives, 2, 5- disubstituted-4-diazo-N-acyl anilides, p-diazo diphenylamine derivatives.
3. A photosensitive material for diazo photography according to claim 1 in which the dithiocarbamate is a member selected from the group consisting of sodium methyldithiocarbamate, ammonium methylenedithiocarbamate, ethylammonium ethyldithiocarbamate, zinc dimethyldithiocarbamate, sodium octyldithiocarbamate, cyclohexylammonium cyclohexydithiocarbamate, cadmium cyclohexyldithiocarbamate, ammonium propenyldithiocarbamate, potassium octenyldithiocarbamate, sodium benzyldithiocarbamate, ammonium methylbenzyldithiocarbamate, ammonium naphthylmethyldithiocarbamate, ammonium phenyldithiocarbamate, diphenyldithiocarbamic acid, sodium diphenyldithiocarbamate, sodium piperidine-N-carbodithionate, sodium morpholine-N-carbodithionate, morpholinoethyldithiocarbamic acid, 1-piperidinylethyldithiocarbamic acid, sodium ethylenebis-dithiocarbamate, sodium octamethylene bis-dithiocarbamate, ammonium propylene bis-dithiocarbamate, sodium p-phenylene bis-dithiocarbamate and hexamethylene ammonium hexamethylene dithiocarbamate.
4. A photosensitive composition for diazo photography which comprises a photolytic aromatic diazonium salt, at least one member selected from the group consisting of dithiocarbamates of the formulas I and II, ##SPC33##
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a photosensitive material for diazo photography, and more particularly to a photosensitive material for diazo photography sensitized with a dithiocarbamate.
2. Description of the Prior Art
Diazo photography is based on the photolysis of aromatic diazo compounds such as diazonium salts, metal complexes thereof and diazosulfonates. If desired, coupling components are used together to produce dye images, print images or bubble images.
Heretofore, various diazo photographic processes have been known. One of them uses a photolytic diazo compound, a coupling component and a coupling controlling agent. This diazo photographic process is further divided into a wet process and a dry process. In the wet process a photosensitive paper is used having a coating of a photolytic diazo compound only and after exposure to a light image the photosensitive paper is developed using a solution containing a coupling component. In contrast, the dry process utilizes a photosensitive paper having a coating containing a photolytic diazo compound, a coupling component and a coupling controlling agent and this is exposed to a light image followed by developing with ammonia gas.
Further, process is known where a photosensitive member having a photolytic diazo compound dispersed in a thermoplastic binder is exposed to a light image and is then heated to produce a light-scattering image composed of air bubbles. Furthermore, other various modified diazo photographic processes are known. However, light energy necessary for the photolysis of photolytic aromatic diazo compounds used in the diazo photographic processes is very large and the photosensitive spectrum ranges only up to visible blue region and therefore, these diazo photographic materials can be practically used only as low sensitive ultraviolet printing materials.
In spite of the fact that diazo photography itself has been known for a long time, the intrinsic sensitization and the spectral sensitization have not been achieved.
The present invention solves the above mentioned problems and increases the intrinsic sensitivity and the spectral sensitivity of the photolysis of photolytic aromatic diazo compounds.
SUMMARY OF THE INVENTION
According to the present invention, the photosensitive material for diazo photography comprises, in combination, a photolytic aromatic diazo compound and at least one member selected from the group consisting of dithiocarbamates of the formulas I and II, ##SPC1##
where R 1 and R 2 may be, similar or dissimilar, selected from the group consisting of hydrogen, a substituted or an unsubstituted alkyl, a substituted or an unsubstituted alkenyl, a substituted or an unsubstituted cycloalkyl, substituted or an unsubstituted aralkyl, a substituted or an unsubstituted aryl, a substituted or an unsubstituted 5-membered heterocyclic ring radical, and a substituted or an unsubstituted 6-membered heterocyclic ring radical, and R 1 and R 2 , taken together, may form a ring; R 3 is a divalent organic radical, for example, a divalent hydrocarbon radical such as alkylene, phenylene and the like; and M is, similar or dissimilar, selected from the group consisting of a hydrogen ion, a metal ion, an ammonium ion, and an organic cation. When M is a polyvalent metal ion, it should be understood that the number of the M attached is that divided by the valency value. For example, when M is divalent, M is substituted therefor in the Formulas I and II. If desired, the photosensitive material may contain additionally a sensitizing dye.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Representative dithiocarbamates as shown by Formulas I and II above are used in the present invention for sensitizing a photolytic aromatic diazo compound as shown below:
1. Sodium methyldithiocarbamate ##SPC2##
2. Ammonium methylenedithiocarbamate ##SPC3##
3. Ethylammonium ethyldithiocarbamate ##SPC4##
4. Zinc dimethyldithiocarbamate ##SPC5##
5. Sodium octyldithiocarbamate ##SPC6##
6. Cyclohexylammonium cyclohexyldithiocarbamate ##SPC7##
7. Cadmium cyclohexyldithiocarbamate ##SPC8##
8. Ammonium propenyldithiocarbamate ##SPC9##
9. Potasium octenyldithiocarbamate ##SPC10##
10. Sodium benzyldithiocarbamate ##SPC11##
11. Ammonium methylbenzyldithiocarbamate ##SPC12##
12. Ammonium naphthylmethyldithiocarbamate ##SPC13##
13. Ammonium phenyldithiocarbamate ##SPC14##
14. Diphenyldithiocarbamic acid ##SPC15##
15. Sodium diphenyldithiocarbamate ##SPC16##
16. Sodium piperidine - N - carbodithionate ##SPC17##
17. Sodium morpholine-N-carbodithionate ##SPC18##
18. Morpholinoethyldithiocarbamic acid ##SPC19##
19. 1-piperidinylethyldithiocarbamic acid ##SPC20##
20. Sodium ethylene bis-dithiocarbamate ##SPC21##
21. Sodium octamethylene bis-dithiocarbamate ##SPC22##
22. Ammonium propylene bis-dithiocarbamate ##SPC23##
23. Sodium p-phenylene bis-dithiocarbamate ##SPC24##
24. Hexamethylene ammonium hexamethylene dithiocarbamate ##SPC25##
These compounds may be prepared from the corresponding amine and carbon disulfide. Some detailed methods for preparation thereof are described in "RECUEIL", 70 917-939 (1951) and "Journal Praktische Chemie", 67 286-287 (1903).
Conventional sensitizing dyes, such as those used for sensitizing silver halides and zinc oxide may be used in this invention. Representative examples thereof are: triphenylmethane dyes such as Brilliant Green, Crystal Violet and Acid-Violet 6B; rhodamines such as Rhodamine B, Rhodamine 6G, Rhodamine G Extra, Sulforhodamine B and First-Acid-Eosine G; xanthene dyes such as Eosine S, Eosine A, Erythrosine, Phloxine, Rosebengale and fluorescein; thiazine dyes such as methylene blue, methylene green, methylene violet, methylene azine, thionine blue, toluidine blue, and Thiocarmine R; acridine dyes such as acridine yellow, acridine orange and Trypaflavin; quinoline dyes such as pinacyanol and cryptocyanine; quinone dyes such as alizarine, alizarine red S, quinizarine; cyanine dyes; aryl methane dyes such as Erythrosine 2Na, Rhodamine B 500, Fanal Pink B, Rhodamine 6GDN, and auramine; polymethine dyes such as 3, 3'-diethylthiacarbocyanine iodide; azo dyes such as Eriochrome blue black R, azo methine dyes such as bis(p-dimethylamino benzal) azine; carbonyl dyes such as Solway Ultrablue B, arizaline cyanine green GWA; and phtholocyanine dyes such as Segnale light turquoise NB.
Among the above-mentioned sensitizing dyes, thiazine dye, xanthene dye, and acridine dye are preferably used to increase spectral sensitivity. As photolytic aromatic diazo compounds are used in this invention and sensitized by the addition of a dithiocarbamate (I) or (II) and a sensitizing dye, conventional photolytic aromatic diazo compounds usable in diazo photography may also be used.
Representative examples thereof are:
1. P-diazo mono (or di-) alkylaniline derivatives such as: p-diazo methylaniline hydrochloride, p-diazo dimethylaniline hydrochloride, p-diazo ethylhydroxylethylaniline hydrochloride, p-diazo m-chloro diethylaniline hydrochloride, and p-diazo o-methoxy diethylaniline sulphate;
2. 2,5-Disubstituted-4-diazo-N-acyl anilids such as 4-diazo-2, 5-diethoxy-N-benzoyl anilid;
3. P-diazo diphenylamine derivatives such as p-diazo diphenylamine sulphate;
4. Sulphur containing diazo compounds such as: ##SPC26##
5. Diazo oxides such as: ##SPC27##
6. Diazo polymer such as the condensation product of p-diazo diphenylamine and formaldehyde in sulfuric acid.
These photolytic diazo compounds are described in detail in Kosar: "Light-Sensitive Systems-Chemistry and Application of Nonsilver Halide Photographic Processes," chapters 6 and 7, published by John Wiley & Sons, Inc.
The dithiocarbamate and the sensitizing dye may be incorporated in a photosensitive layer of a photosensitive member of diazo photography. The amount of dithiocarbamate to be added to a photolytic aromatic diazo compound is not critical. However, it is preferable to use from 0.5 to 10 moles of dithiocarbamate per one mole of diazo compound.
A diazonium salt or diazo sulfonate, a coupler, a stabilizer and other additives are made into an aqueous solution or an aqueous alcoholic solution, and a dithiocarbamate and, if desired, a sensitizing dye are added thereto, and the resulting mixture is coated on a support such as paper and film and dried. This diazo photosensitive material is then exposed to a light image and developed with ammonia gas to produce an azo dye image at a non-exposed portion. When a photosensitive material excluding a coupler is used, the diazo photosensitive member exposed to a light image is developed by an aqueous alkaline solution of a coupler to produce an azo dye image. The preparation of the photosensitive member is carried out in a dark room.
Formulation of conventional diazo photosensitive material may be employed except than a dithiocarbamate and, if desired, a sensitizing dye are added. The details are described in "Kagaku Shashin Binran" (Handbook of Scientific Photography), edited by Shinichi Kikuchi, 2nd Volume, pages 335 - 337.
A diazo photosensitive material for bubble photography may be prepared by adding a dithiocarbamate and, if desired, a sensitizing dye to a photosensiteve material formulation of conventional bubble photography. For example, a diazonium salt, a dithiocarbamate and a sensitizing dye are added to a solution of a hydrophobic binder resin, coated on a film and dried. In this case, the diazonium salt and the dithiocarbamate are preferably soluble in organic solvents.
In the following, it is explained by using examples that the addition of a dithiocarbamate of Formula I or II described above and a sensitizing dye to a photolytic aromatic diazo compound results in remarkable increase in velocity of photolysis of the photolytic aromatic diazo compound and renders the photolytic aromatic diazo compound decomposable by a visible light.
p-Phenylaminobenzene diazonium sulfate (100 mg.) is dissolved in 50 ml. of a phosphoric acid buffer solution at pH 6.0 to give "Sample 1." A solution of hexamethylene ammonium hexamethylene dithiocarbamate (300 mg.) in 50 ml. of the above mentioned buffer solution at 6.0 is added to "Sample 1" to form "Sample 2." 10 mg. of Methylene Blue is added to Sample 2 to obtain "Sample 3."
Sample 1, Sample 2 and Sample 3 are placed in test tubes, and exposed to a 1 KW tungsten lamp at a distance of 20cm. through an infrared ray absorbing filter HR-1-69 (trade name, supplied by Dow Corning) and a Toshiba Glass Filter VR-62 (trade name, supplied by Toshiba). As a result, the release of a nitrogen bubble is recognized only in the test tube containing Sample 3. A light with a wave length of 360 μ is then projected from a monochrometer having a 500 W xenon lamp as a light source. The released nitrogen from Sample 2 and Sample 3 is markedly larger than that from Sample 1.
Samples 1, 2 and 3 are impregnated in filter paper, dried by air-blowing at a temperature below 50°C and irradiated by a 1 KW tungsten lamp through the above mentioned filter, and then sprayed with an alkaline solution of β-naphthol. As a result, Sample 1 and Sample 2 become reddish purple while no color is observed in Sample 3.
An aqueous solution containing 4-diazodiphenylamine sulfate (5 × 10 -5 mole/1.), hexamethylene ammonium hexamethylene dithiocarbamate (1 × 10 -4 mole/1.) and Methylene Blue (2 × 10 -5 mole/1.) is adjusted to pH 6.0 by using a phosphoric acid buffer solution.
The absorption spectra of the resulting solution is measured at sample thickness of 10 μ and absorption peaks at 680, 650, 380, 300 and 25 μ are found.
When only 4-diazodiphenylamine sulfate is measured in a way similar to above, the absorption peaks at 680 and 650 μ are not observed and the absorption peaks at 380, 300 and 250 μ are less than those in the above mentioned case.
The above mentioned phenomena are commonly observed with respect to photolytic aromatic diazo compounds used for diazo photography. When the above mentioned phenomena are utilized in photosensitive material for diazo photography, the application field of diazo photography can be broadened. In other words, an inexpensive ultraviolet fluorescent lamp can be used for rapid exposure rather than a high pressure mercury lamp normally used in diazo photography. Furthermore, a tungsten lamp can be used in diazo photography. Additionally, reproduction of the colored original is also possible.
The following examples are given to illustrate the present invention, but should not be construed as limitations thereof.
EXAMPLE 1
There was prepared 1000 ml. of an aqueous solution containing 10 g. of 4-benzoylamino-3,5-diethoxybenzene diazonium chloride and 10 g. of thiourea. 30 g. of hexamethylene ammonium hexamethylene dithiocarbamate was added to one half of the resulting solution, it was coated on a paper and dried. The other half of the original aqueous solution was also coated on a paper and dried as well. These two sample papers thus prepared were exposed to a blue fluorescent lamp of a printing device for positive photosensitive paper.
The former paper containing the dithiocarbamate gave images free from fog at a rapid speed about twice that of the paper not containing dithiocarbamate.
EXAMPLE 2
Photosensitive papers were prepared by using the formulations as shown in Table 1 below in a way similar to Example 1:, irradiated by a 20 W blue fluorescent lamp at a distance of 20 cm. and developed with ammonia a reciprocal of exposure time (seconds) required for obtaining 0.05 of density of background was obtained.
The Table 1 below shows the relative sensitivity referring to the control sample.
TABLE 1
Number of Relative dithiocarbamate Diazo compound sensitivity compound as mentioned above ____________________________________________________________
______________ ##SPC28## None 150 (1) 320 (5) 300 (6) 300 (7) 280 (9) 310 (10) 290 (13) 300 (15) 320 (16) 310 (19) 310 (20) 290 (23) 280 ____________________________________________________________
______________ ##SPC29## None 200 (3) 400 (4) 400 (6) 370 (8) 410 (10) 380 (11) 390 (14) 370 (17) 360 (18) 390 (20) 400 (21) 390 (22) 400 ____________________________________________________________
______________ ##SPC30## None 100 (1) 220 (2) 200 (4) 200 (6) 190 (8) 210 (9) 200 (10) 180 (12) 190 (15) 210 (18) 180 (20) 180 (21) 190 (23) 180 ____________________________________________________________
______________ ##SPC31## None 60 (1) 120 (3) 120 (5) 120 (7) 100 (9) 100 (11) 130 (12) 110 (13) 120 (14) 100 (16) 110 (17) 110 (19) 110 (22) 130 (23) 120 ____________________________________________________________
______________
EXAMPLE 3
1000 ml. of an aqueous solution containing p-dimethylaminobenzene diazonium chloride 10.0 g., sodium 2,3-dihydroxynaphthalene-6-sulfonate 20.0 g., thiourea 10g. was prepared and diethyleneglycol 10g. In the resulting aqueous solution 30 g. of hexamethylene ammonium hexamethylene dithiocarbamate and 1.0g. of Methylene Blue were dissolved. To this solution 0.1g. of saponin was coated on a paper and dried. The resulting photosensitive paper was closely contacted with an original image on one side of a paper and exposed by using a contact printer for photographic paper (two 500 W flood lamps used as a light source). Then, the exposed photosensitive paper was placed in a desiccator saturated with ammonia gas for three minutes to form a clear blue image.
This photosensitive paper excluding hexamethylene ammonium hexamethylene dithiocarbamate and Methylene Blue failed to produce an image.
EXAMPLE 4
The procedure of Example 3 was followed except p-N-ethyl-N-ethoxyaminobenzene diazonium chloride, 4-benzoylamino-2,5-diethoxybenzene diazonium chloride, p-phenylaminobenzene diazonium sulfate, 4-ethylthio-2,5-diethoxybenzene diazonium chloride, 4-diazo-2,5-diethoxyphenylethylmercaptan and 2,5-dimethyl-p-diazo-N-phenylanilide were used in place of p-dimethylaminobenzene diazonium chloride. Clear images were also obtained.
EXAMPLE 5
1000 ml. of an aqueous solution containing 10g. of 4-benzoylamino-3,5-diethoxybenzene diazonium chloride and 10g. of thiourea was prepared. To this aqueous solution 30g. of hexamethylene ammonium hexamethylene dithiocarbamate and 1.0g. of Rose Bengal were added and it was coated on a paper and dried. In a way similar to Example 3, the resulting photosensitive paper was contacted with an original and exposed, and then soaked in an aqueous solution (1000 ml.) containing 10g. of sodium 1-naphthol-4-sulfonate, 20g. of sodium carbonate and 25g. of borax, squeezed by a rubber roller and dried. A clear bluish purple image was obtained.
EXAMPLE 6
A solution composed of 10.0g. of polyvinylidene chloride, 2.0g. of polymethylmethacrylate and 50 ml. of methyl ethyl ketone was prepared, and to the resulting solution was added a solution (12 ml.) of 1.5g. of p-dimethylaminobenzene diazonium chloride - zinc chloride complex in methanol.
Further, a methanol solution (10 ml.) containing 0.5g. of sodium N, N-diphenyldithiocarbamate and 0.1g. of Rose Bengal was added thereto and the resulting mixture solution was immediately coated on a polyester film of 75μ in an amount to form a coating of about 10μ thick when dried, and dried at a temperature below 70°C.
The resulting photosensitive film was closely contacted with a negative microfilm and exposed in a way similar to that of Example 3, followed by its being pressed with a roller at 120°C for about one second to produce a light-scattering image composed of nitrogen bubble at the exposed portion.
EXAMPLE 7
Diazo resin (3.0g.), obtained by condensing p-phenyl-aminobenzene diazonium sulfate and paraformaldehyde in a dark and cool place was dissolved in a 50 percent aqueous solution of methanol. To the resulting solution were successively added 1.0g. of morphorinoethyl dithiocarbamic acid and 100 mg. of Rose Bengal and then the resulting solution was coated on a sand blasted aluminum plate and dried. The resulting photosensitive plate was closely contacted with a negative original and exposed by using a 500W flood lamp at a distance of 50 cm. for 3 minutes, followed by developing it with an aqueous methanol to harden the diazo resin at the exposed portion to produce an offset printing plate.