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

• Iii practice one-component diazotype materials which have been sensitized with 4-diazo-2-chloro-N,N-diethylvaniline are used on a large scale. They are developed according to the so-called thin-layer method with weakly alkaline developing liquids which contain phloroglucinol, if desired together with resorcinol, and then yield copies with brown azo-dyestufr images that have high absorption for ultraviolet rays and are extremely suitable for use as intermediate originals if the support material is translucent.
• the brown colour of the azo-dyestuff of the copies on these diazotype materials, developed with weakly alkaline phloroglucinol developer, is not appreciated by all users of these materials. Many of them consider it too light.
• the copies sometimes show bleeding of the azo-dyestuff, in consequence of which the images are less sharp. This bleeding may be due to the dissolution of the diazo compound in the developing liquid during development, the azo-dyestutf formed from the dissolved diazo compound being deposited beyond the azo-dyestuif portions of the image on the surface of the copy. It may also be due to the azo-dyestuff formed in the azo-dyestutf portions being washed away with the developing liquid.
• diazotype materials are not suitable for development with weakly acid buffered phloroglucinol developers, because the diazo compound does not couple sufficiently actively.
• weakly acid buffered phloroglucinol developers have better keeping qualities than weakly alkaline phloroglucinol developers.
• the South African Patent No. 3,627/60 describes onecomponent diazotype material which comprises a diazo film layer, sensitized with a diazo compound that couples more actively than 4-diazo-2-chloro-N,N-diethylaniline.
• This diazotype material can be developed with weakly acid liquids containing phloroglucinol and, if desired, resorcinol, which liquids have been buffered with a salt of a strong base and a dicarboxylic acid such as succinic acid, glutaric acid, adipic acid, and fi-methyladipic acid.
• the said South African patent describes, among other things, transparent diazotype material with a diazo film layer in which 4-diazo-2-chloro-N-methyl-N-cyclohexylaniline is present as diazo compound.
• This material is developed with a liquid which contains phloroglucinol and resorcinol as azo components and a mixture of sodium succinate, succinic acid, and sodium benzoate as buffer.
• the pH of this liquid is 6.6.
• After the application of the developing liquid the copy is dried while heating moderately.
• copies are obtained with strong, dark violet-brown azo-dyestuif images on a clear transparent background.
• the azo-dyestuff has very good absorption for ultraviolet light and hardly bleaches upon prolonged or repeated exposure to this light.
• the use of the said special weakly acid buffered phloroglucinol developer is more or less required and the copies have to be heated after the application of the developing liquid in order to ensure proper development. Nevertheless, the developing speed of these materials is often too slow for practical purposes (even when the said special developer is used) if their light-sensitive layer contains the diazo compound in the form of the zinc chloride double salt together with the stabilizer 1,3,6- naphthalene trisulphonic acid or a water-soluble salt thereof.
• the use of the zinc chloride double salt of the diazo compound together with this stabilizer is highly desirable, because these diazotype materials otherwise are not very durable.
• the material is developed much less satisfactorily according to the thin-layer method than when, for instance, the chloride or the two-basic sulphate is used.
• 1,3,6-naphthalene trisulphonic acid retards the coupling activity of 4-diazo-2-chloro-N-methyl-N- cyclohexylaniline in a high degree.
• the degree of re tardation is indeed dependent on the quantity of stabilizer that is added, but it is already considerable upon addition of the usual quantity desirable for good stabilization.
• the retarded developing speed may have all sorts of harmful consequences,
• the visual and the transmission contrast of a copy which has been exposed to daylight for some time, for instance may be considerably lower than that of a freshly developed copy, because the diazo compound that has not been converted into azodyestuff during development bleaches gradually.
• the copies which originally had a clear background are often found to show fogging in the background portions after a few minutes in consequence of the slowness with which the development proceeds in those portions in which after the imagewise exposure only a small amount of diazo compound is left. Consequently, the quality of the copies can only be judged some time after development, a circumstance which is naturally very inconvenient in practice. Moreover the copies often show bleeding.
• one-component diazotype material containing a diazo compound of the general formula methyl XN N cyclohexyl R 2 in which X is an anion, R and R are chlorine or bromine atoms, and the cyclohexyl group may be substituted by one or more methyl radicals, can be stabilized in the usual way with 1,3,6-naphthalene trisulphonic acid or a salt thereof, without the coupling activity of the diazo compound, in this case the developing speed of the diazotype material, decreasing in a degree that is inconvenient for practical purposes.
• the diazotype material according to the invention is very light-sensitive and it can be developed with weakly acid buflered phloroglucinol-containing developing liquids to form dark, almost black azo-dyestuffs which have high absorption for actinic radiation, and with weakly alkaline phloroglucinol-containing developing liquids to form fine dark-brown azo-dyestuffs which also have high absorption for actinic radiation.
• the azo-dyestuff images obtained with weakly acid buffered phloroglucinol developers do not, or in a much less degree, show the above-mentioned phenomena, which point to incomplete development.
• diazotype material according to the invention bleeding of the azo-dyestuff image occurs in a much less degree than when diazotype material sensitized with 4-diaZo-2-chlorodiethylaniline or 4 diazo 2 chloro N-methyl-N-cyclohexylaniline is used.
• the support of the diazotype material according to the invention may be opaque, such as paper, linen, lacquered paper, or translucent, such as tracing paper that may or may not be lacquered, tracing linen, cellulose acetate and polyester film. If the support surface is hydrophobic, the diazo compound is preferably applied in a hydrophilic film layer which covers the hydrophobic surface. If the support is transparent or at least translucent, the copies are very suitable as intermedaite originals, irrespective of whether they are developed with a weakly acid or with a weakly alkaline phloroglucinol developer.
• Very attractive material is one-component diazotype material according to the invention which comprises a transparent support, such as natural tracing paper, tracing linen, or polyester film that has been coated with a film layer formed from a hydrophilic colloid obtained by hydrolysis of an ester of the group formed by cellulose and polyvinyl esters, in which film layer the diazo compound is present along with l,3,6-naphthalene trisulphonic acid or a water-soluble salt thereof.
• a transparent support such as natural tracing paper, tracing linen, or polyester film that has been coated with a film layer formed from a hydrophilic colloid obtained by hydrolysis of an ester of the group formed by cellulose and polyvinyl esters, in which film layer the diazo compound is present along with l,3,6-naphthalene trisulphonic acid or a water-soluble salt thereof.
• This diazotype material has good keeping qualities, is developed practically completely within a short time with a weakly acid bufiered phloroglucinol-containing developing liquid according to the thin-layer method, and yields sharp copies with strong dark azo-dyestutf images, which have high absorption for ultraviolet light.
• the azo-dyestuff images of the copies can be readily erased, for instance by scraping off the film layer with a blade.
• diazotype material according to the invention in which the diazo compound is present in the form of the zinc chloride double salt along with 1,3,6-naphthalene trisulphonic acid or a water-soluble salt thereof in a hydrophilic film layer as described above are particularly good. Notwithstanding the use of the diazo compound in the form of the zinc chloride double salt, such diazotype material is developed sufiiciently rapidly with the weakly acid buffered phloroglucinol-containing developing liquids.
• Diazo compounds which are suitable for application in the diazotype material according to the invention are, for instance:
• the diazotype material according to the invention may contain the auxiliary agents commonly used in one-component diazotype material, for instance acids such as citric acid, boric acid, tartaric acid, stabilizers such as 1,3,6- naphthalene trisulphonic acid and its water-soluble salts, reducing agents such as thiourea, metal salts such as aluminum sulphate, synthetic resin dispersions, silica disperions, etc.
• acids such as citric acid, boric acid, tartaric acid, stabilizers such as 1,3,6- naphthalene trisulphonic acid and its water-soluble salts
• reducing agents such as thiourea
• metal salts such as aluminum sulphate
• synthetic resin dispersions silica disperions, etc.
• Example I Sized natural tracing paper is sensitized with a liquid containing:
• the transparent diazotype paper thus prepared is very light-sensitive and has good keeping qualities.
• a sheet of the diazotype material is imagewise exposed underneath an ink tracing until underneath the blank portions of the tracing all the diazo compound has been bleached out, and then developed according to the socalled thin-layer method with a weakly acid liquid containing:
• the developing liquid has a pH of about 6.2.
• the copy obtained shows a strong violet-black azo-dyestuff image on a clear background and is eminently suitable for use as an intermediate original for making further copies.
• the azo-dyestuff image does not bleed upon development.
• Another sheet of the diazotype material is imagewise exposed as described above and then developed with a weakly alkaline liquid of the following composition:
• the copy obtained shows a strong, sharp, and fine darkbrown azo-dyestuff image, the azo-dyestuff of which has high absorption for ultraviolet radiation.
• Example 11 A cellulose acetate film layer of about g./m., applied on natural tracing paper of about 80 g./m. is superficially hydrolysed to a depth of about 4 microns and, after washing with water to remove the chemicals used for the hydrolysis, is sensitized with a solution of:
• the diazotype material obtained is very light-sensitive and has excellent keeping qualities.
• a sheet of the diazotype material is imagewise exposed as in Example I and developed with the weakly acid developing liquid mentioned in that example.
• the diazotype material has a markedly greater developing speed and yields markedly sharper and even darker-coloured azo-dyestutf images than corresponding diazotype material which contains an equivalent quantity of the zinc chloride double salt of 4'N-methyl-N-cyclohexylamino-3- chlorobenzene diazonium chloride.
• the new diazotype material Upon development with the weakly alkaline developing liquid described in Example I, the new diazotype material yields transparent copies with a strong dark-brown azo-dyestuft image, the azo-dyestuff of which has high absorption for ultraviolet radiation.
• Example III White base-paper of 80 g./m. for the diazotype process is sensitized on one side with a solution of g. of 4-N-methyl-N-(methyl)cyclohexylarnino-3,6-dichlorobenzene diazonium chloride, zinc chloride double salt 5 g. of tartaric acid 30 g. of 1,3,6-naphthalene trisulphonic acid sodium salt 30 ml. of Vinnapas H. 60 in 1000 ml. of water and dried.
• the diazotype paper obtained is very light-sensitive and has excellent keeping qualities.
• a sheet of the diazotype paper is imagewise exposed as in Example I and then developed with a thin layer of the weakly acid developing liquid described in Example I.
• the copy shows a sharp and strong violet-black azo-dyestuif image on a clear white background.
• the new diazotype material is developed with the weakly alkaline developing liquid described in Example I, the azo-dyestuif image has a fine dark-brown shade.
• Example IV White paper of 150 g./m. provided on one side with a cellulose acetate film layer (approximately 50% by weight of combined acetic acid) of a thickness of about 10 microns, which has been fixed to the paper by means of an adhesive and which has been deacylated to a depth of about 4 microns to an average acetyl content, calculated as combined acetic acid, of approximately 20% by weight (which corresponds to an average number of acyl groups on the OH-- groups of 0.7), is impregnated for 2.5 minutes on the deacylated side of the cellulose acetate layer with the following solution:
• the excess of liquid is removed from the cellulose acetate surface and subsequently the material is dried.
• the diazotype material obtained is very light-sensitive and has good keeping qualities.
• a sheet of the diazotype material is imagewise exposed as in Example I and developed with the weakly acid developing liquid described in that example.
• the copy obtained shows a very strong violet-black azo-dyestufif image, which did not bleed upon development. If instead of the weakly acid developer the weakly alkaline phloroglucinol developer described in Example I had been used, a copy with a very strong, fine dark-brown azodyestutf image would have been obtained.
• Example V Tracing linen of the Red Bridge Sub./0/86 type from Red Bridge Book Cloth Company, Red Bridge, Ainsworth, Bolton, England, is coated by immersion with a layer of about 70 g./m. of the following liquid:
• a sensitizing liquid is prepared as follows.
• the hydrophilic light-sensitive layer obtained after drying contains approximately 0.8 millimol of diazo compound per m. of the sensitized surface.
• a sheet of the transparent diazotype linen thus produced is imagewise exposed as in Example I and developed with the weakly acid developing liquid.
• the copy obtained shows a dark violet-brown azo-dyestuff image with good absorption for ultraviolet radiation. It is eminently suitable for use as an intermediate original for making further copies.
• the image on the copy can easily be removed (erased) locally, for instance by scraping off parts of the hydrophilic layer containing the azo-dyestufl image.
• a copy also having good absorption of the azo-dyestuif image is obtained upon development With the Weakly alkaline developing liquid described in Example I.
• the azo-dyestuff image has a brown shade.
• hydrophilic polyvinyl acetate layer is impregnated with a sensitizing liquid prepared in the same way, but starting from 4-N-methyl-N-cyclohexylamino-3-chloroaniline, after the drying process a light-sensitive material is obtained which practically cannot be developed with the weakly acid developing liquid. A reasonable, though very sloW, development is achieved if the quantity of 1,3,6-naphthalene trisulphonic acid sodium salt is reduced to one third of the original quantity.
• One-component diazotype material comprising a support carrying a light-sensitive layer containing a diazo compound of the general formula:
• R and R are selected from the class consisting of chlorine and bromine atoms, and R is selected from the class consisting of a cyclohexyl radical and methyl substituted cyclohexyl radicals.
• One-component diazotype material according to claim 1, said support comprising a transparent sheet material coated with a film layer of a hydrophilic colloid formed by hydrolysis of an ester selected from the group consisting of cellulose and polyvinyl esters, which film layer contains said diazo compound together with a stabiliz/er selected from the group consisting of 1,3,6-naphthalene itrisulfonic acid and water-soluble salts thereof.
• One-component diazotype material according to claim 2 characterized in that the diazo compound is present in the film layer in the form of the zinc chloride double salt of said compound.
• One-component diazotype material comprising a support carrying a light-sensitive layer containing a salt of 4 N methyl-N-cyclohexylamino-3,6-dibromodiazobenzene.
• One-component diazotype material comprising a support carrying a light-sensitive layer containing a salt of 4 N methyl-N-cyclohexylamino-3,6-dichloro-diazobenzene.
• One-component diazotype material comprising a support carrying a light-sensitive layer containing a salt of 4-N-methyl-N-cyclohexylamino-3-chloro-6-brom0-diazobenzene.
• One-component diazotype material comprising a support carrying a light-sensitive layer containing a salt of 4-N-1nethyl-N-(methyl) cyclohexylamino-3,6-dichlorodiazobenzene.

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• 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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  • NL NL275942D patent/NL275942A/xx unknown
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  • NL NL120335D patent/NL120335C/xx active
• 1962
  • 1962-09-17 US US224237A patent/US3238044A/en not_active Expired - Lifetime
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  • 1963-02-07 FI FI0230/63A patent/FI40267B/fi active
  • 1963-02-22 GB GB7297/63A patent/GB972951A/en not_active Expired
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