Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/52—Compositions containing diazo compounds as photosensitive substances
  • G03C1/54—Diazonium salts or diazo anhydrides

Definitions

• This invention relates to light-sensitive layers for diazotype prints, and more particularly to such layers containing light-sensitive diazo compounds which are characterized by having both abenzyloxy and an acylamino substituent in the aromatic ring to which the diazo group is attached.
• Diazotyp printing is an established art and a variety of light-sensitive compounds are used therein.
• the light-sensitive layers are printed by irradiating with light through transparencies having designs blackedout or drawn thereon. In the exposed areas, the diazo compound is destroyed While in the dark or shadow areas, it is not destroyed.
• the print is developed by reaction with a so-called azo coupling component, such as, for instance, phloroglucinol.
• the development step results in the production of an azo dye.
• both the diazo compound and the coupling component are coated on a diazotype paper, and after printing, the coupling reaction is carried out by treatment with moisture or ammonia gas.
• the azo component is applied to the paper as a solution in a solvent.
• the latter type or one-component papers have agreater stability than the former or two-component papers. That is, they have better storage and keeping qualities than the two-component type papers.
• the one-component type papers give dark developed lines and better contrast between the lines and the background.
• the final azo dye should have a dark color and the background should be of a very light or white color and substantially free of discoloration. Discoloration of the background may be due to decomposition products of the diazo compound which was burned out in the printing process or to oxidation of the phenolic materials applied by the developing solution.
• the diazo compounds embodying the invention have a high coupling activity and couple with an azo coupling component, such as phloroglucinol, practically instantaneously even at a pH of 9 or lower.
• azo coupling component such as phloroglucinol
• These diazo compounds have a relatively low solubility in the liquid developer solution which may be reflected in the lack of any tendency for the diazo compound, or intermediate or final reaction products thereof with the coupling component, to bleed when being developed.
• the developed image remains very sharp and accurate reproductions or copies of a desired subject matter can be made very readily.
• Diazotype prints obtained by means of compounds of the invention range in color from black to very dark red.
• the new diazo compounds it is possible to obtain sharp dark lines from transparencies having black pencil or black ink lines, so that the reproduction substantially duplicates the original drawing or subject matter in all particulars.
• the diazo compounds of the present invention are derived from anilines having the following general formula:
• X-- is an acylamino radical selected from the group consisting of Specific compounds which come within the scope of th above general formula are, for instance,
• the diazo derivative may be, for example, the chloride, or salts of any other suitable anion, or the metal salt complexes therewith, such as the zinc chloride complex of the diazo chloride derivative.
• These compounds may be prepared from hydroquinone as a starting material.
• One hydroxyl may be etherified with a benzyl group by treatment with the stoichiometric amount for one ether group of benzyl chloride in the presence of caustic, and then the second hydroxyl group may be etherified with a similar group by a similar procedure.
• Both hydroxyl groups may be etherified simultaneously, for instance, by treatment with an excess of the benzyl chloride required for the two ether groups.
• the resulting di-etherified compound may be mononitrated by treatment with nitric acid in the presence of acetic acid as the solvent.
• the mono-nitro compound obtained may be reduced to the corresponding aniline, for instance, by treatment with finely divided iron and hydrochloric' acid in a boiling alcohol solution, or by catalytic hydrogenation under pressure,
• the resulting substituted aniline may be treated with an acylating agent to form the corresponding amido or imido substituted compound.
• the acylated compound may then be nitrated again by the above procedure.
• This nitro group is believed to enter into the ring at the position para to the acylated amino group in View of the para directing influence of the amido group plus the ortho directing influence of the benzyloxy group which is in a meta position relative to the acylated amino group.
• the resulting nitro compound may be reduc'ed by the above discussed procedures to the corresponding 2,5-di-etherified aniline containing a benzyloxy group in the 5-position and an acylated amino group in the 4-position.
• This aniline may be diazotized by dissolving in a solution such as hydrochloric acid and treating with sodium nitrite, or nitrous acid.
• the resulting diazo compound may be precipitated by forming a metal salt complex thereof, such as a zinc chloride complex of the diazo chloride derivative. Such complexes are relatively insoluble in water.
• the reaction mass was-treated with aqueous zinc chloride solution and a light yellow colored zinc chloride complex of the diazo chloride derivative of the above aniine was obtained as a precipitate.
• the product is believed to be a diazo derivative of 2,5-di-benzyloxy-4-acetamidoaniline.
• the resulting coated paper was printed by light from a standard diazotype printing machine with a transparency having a drawing thereon for seconds.
• the shaded portions retained the yellow color of the light-sensitive coating and the irradiated portions printed out substantially to the white color of the original paper.
• the printed diazotype paper was then developed by treatment in a commercial semi-dry developing machine using a liquid developer or" the following composition:
• Example 2 2,5-benzyloxy aniline was prepared in accordance with the procedures of Example 1. 32 grams thereof was dissolved in benzene with the aid of heat and refluxing. 13 grams of succinic anhydride was dissolved in cc. of hot benzene and added to the aniline solution. The resulting mixture, or mass, was heated with refluxing for two hours. Wool-like crystals precipitated from the hot solution. The solution was cooled, filtered, and Washed with benzene and then with alcohol. The resulting product, 2-succinimido 1,4 dibenzyloxy benzene, was mono-nitrated to give 4-succinylimino 2,5-di-benzyloxy nitrobenzene.
• This nitro compound was then reduced to the corresponding aniline by means of powdered iron and hydrochloric acid in a hot commercial denatured alcohol solution.
• This substituted aniline is a white solid which melts at 168 to 170 C. It was diazotized following the procedure of Example 1 and recovered as the zinc chloride complex, which was a yellow-brown powder. This product is believed to be a diazo derivative of 2,5- di-benzyloxy-4-succinimido aniline.
• diazotype sheets were made up from this diazo compound zinc chloride complex, printed and developed.
• the printed sheets developed with either type of developer showed sharp contrasting substantially black lines on a substantially white background which had a faint bluish tint.
• the image was accurately reproduced and there was no bleeding or blurring of the lines.
• the developed sheets were allowed to stand open to the atmosphere of a room and ordinary daylight for several months. There was no sign of'deterioration of either the background or printed image.
• the acyl group may be introduced into the amine group with a variety of acid derivatives, such as the acid anhydride or chloride, or in some cases even the free acids themselves.
• the benzamido compound can be prepared by treatment with the benzoyl chloride, in an alkaline solution.
• the formamido compound can be prepared by condensing the benzyloxy aniline with formic acid in boiling benzene.
• the diazo compounds of the invention have a relatively low water solubility. It is possible by repeated coating and drying to produce lightsensitive layers containing sufiicient concentration of the diazo compound to give the desired intensity of printed and developed image. By using a warm solution, fewer coating and drying steps are required. It is more advantageous, however, to use a coating solution of the diazo compound in an aqueous solvent containing an alcohol or a ketone, such as ethanol, methanol, or acetone. It is possible to dissolve the diazo compound in commercial grades of ethanol, methanol; and acetone and use these as coatin solutions, preferably by diluting with water. If the solution is applied to the paper base which is somewhat porous, it may be desirous to incorporate, into the solution, various film forming materials such as dextrine, gelatine, gum arabic, gum tragacanth, or the like.
• the new diazo materials develop readily with known developers, even at a pH of about 5 with some. Though the new compounds are especially suitable for the one component diazotype papers, they could be used in two-component papers of the powder type which are developed with moisture.
• a light-sensitive diazotype material comprising a light-sensitive diazo derivative of a compound having the general formula:
• X is an acylamino-radical selected from the group consisting of formamido, acetamido, propionamido, butyramido, benzamido, phenylacetamido, methoxyformamido, ethoxyformamido, propoxyformamido and succinimido.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Cited By (2)

Citations (5)

• 0
  • NL NL61567D patent/NL61567C/xx active
• 1945
  • 1945-09-07 US US615084A patent/US2456514A/en not_active Expired - Lifetime
• 1946
  • 1946-08-15 GB GB24347/46A patent/GB615774A/en not_active Expired
  • 1946-09-06 CH CH253027D patent/CH253027A/de unknown

Patent Citations (5)

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