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
  • G03C1/62—Metal compounds reducible to metal

Definitions

• This invention relates to a method for obtaining photographic contrasts with the aid of light.
• the decrease in sensitivity of the light-exposed diazosulphonate is substan tially prevented by incorporating into the light-sensitive anti-regression agent which suppresses the tendency of the sensitivity of the exposed diazosulphonate to decrease.
• anti-regression agent as used throughout the specification and in the claims is defined as a substance which prevents the light-decomposition product formed upon exposure to light of the diazosulphonate from reverting to the diazosulphonatc and thereby suppresses the tendency of the sensitivity of the exposed light-sensitive diazosulphonate to decrease.
• the anti-regression agents suitable for the invention are one or more of the following: i
• salts according to b are: paramethoxybenzene diazosulphonic acid lead salt; methyl-1 chloro-3 benzene-diazosulphonic acid-4 zinc salt.
• Suitable acids according to c are: lactic acid and citric acid. Use may be made of mixtures of their alkali salts with the free acid but preferably the salts of the cations falling under a or mixtures thereof are used.
• non-volatile acids and salts of such acids should be used.
• Examples of fast-coupling azo-components according to d are resorcinol; ,B-naphthol; amino-l naphthol8 bisulphonic acid-3.6.
• aromatic monoor polysulphonic acids examples include: naphthalene trisulphonic acid and metasulphobenzoic acid.
• naphthalene-bisulphonic acid lead and a-naphthylarnine sulphonic acid cadmium.
• Example falling'under g is: ammonium tungstenate.
• the pH-value of the solution with which the layer is treated prior to exposure must be less than 7 and accordingly the solution, if necessary, must therefore be admixed with free acid.
• the above cited substances can act as antiregression agents if it is assumed that light reaction converts tthe diazosulphonic acid into an isomeric sulphite compound from which sulphite ions are readily split off and also assuming the reaction to be reversible so that at the end of the exposure the diazosulphonic acid is again formed.
• the antiregression agents are substances which obstruct or prevent the occurence of this reverse re tion. This prevention or obstruction may be effectthcr by combination of the molecule part which con the diazonium group, the sulphite being thus'set free or not being capable of combining again to form diazosulphonic acid, or by combining with the sulphite. it may be as sumed that in the dry layer to which the antiregression agent has been added, the number of the free diazonium ions and free sulphite ions is thus reduced to an extent such that the velocity of their reaction has become substantially nil.
• an antiregression agent may be added which reacts both with the diazo part and with sulphite.
• a particularly intense antiregression effect was obtained by using, as stated under 1'', as the antiregression agent a suitable salt, for example a lead or cadmium salt, of an aromatic sulphonic acid.
• a suitable salt for example a lead or cadmium salt, of an aromatic sulphonic acid.
• lead salts has the advantage that they are generally readily soluble and that both the lead and the sulphonic acid exercise an antiregression effect.
• the sulphite ions which, due to the exposure, are formed from the diazosulphonate abstract mercurous ions from the equilibrium Hgz++ Hg+++Hg
• the typical sulphite binders such as the carbonyl compounds (German specification No.
• layers which, for the purpose of deepening the colour of the azo-dyestulf image, have added to them given metal salts, for example copper or chromium salts.
• the concentration of the antiregression agent not be less than of that of the diazosulphonate employed.
• the extent to which the regression is balanced out also depends on the choice of the diazosulphonate and even the material constituting the support for the photo-sensitive system may be of influence on the choice of the concentration. In favourable cases the regression is substantially rejected and cliazosulphonatcs which due to regression were quite unserviceable are rendered substantially useful by the method according to the invention.
• the photosensitive compound 2-chlorine 4-methyl benzene diazosulphonic acid sodium-1 exhibits an abnormously low sensitivity, even in the case of very quick operation, and that by addition of, for example, ammonium tungstenate, to the sensitising solution the sensitivity and the blackening obtainable becomes substantially equal to those that can be obtained with paramethoxybenzene-diazosulphonate. It is also found that the colour of the silver image thus becomes deep black.
• the azo-component antiregression agent compounds giving a soluble dyestuff with the exposed diazosulphonate may be conveniently used; for the well-known negativepositive dyestuff-image processes, however, such a combination cannot be used since in this case the whole image disappears during washing. However, this is not a disadvantage in the production of images according to the invention. Moreover, due to the use of much lower quantities of light the dyestutf image is very weak and in so far as it is still present it is fully covered by the developed image.
• a suitable test for determining whether or not a substance will be satisfactory antiregression agent is as follows: two solutions of the photosensitive substance are prepared, one with and the other without the substance under examination being provided and soaked therewith are two foils of superficially saponified cellulose-acetate which are exposed in a substantially identical manner behind a sensitometer wedge.
• the exposed foils are treated in a mercurous salt solution and then physically developed. It will be found that a substance which is effectively active as an antiregression agent the decrease in number or blackening, respectively, of the small steps is less.
• the method according to the invention is of prime importance for recording or reproducing various images one after the other on a single piece of material, such, for example, as for microdocumentation.
• layers eontaining a diazosulphonate may be used.
• the method according to the invention is also particularly important for the production of colored images in accordance with Netherlands specification 153,804 because in this case reproducibility is of prime importance, particularly for the production of multi-color images.
• diazosulphonate and diazosulphonic acid they are to be understood to mean one or more organic combinations characterized by the presence of one or more groups N2SO3H or the salts corresponding therewith.
• Example I A superficially saponified cellulose-acetate foil was sensitised with a solution containing 0.2 mol. p-methoxybenzene diazosulphonic acid-sodium and 0.003 mol. citric acid per liter of water and dried. The foil was exposed from a 500 watt mercury lamp. The longest exposure 1 time was 45 seconds and the subsequent exposure times each time were smaller than the preceding one by a value V2. Immediately after the exposure the foil was then treated with a solution of 0.02 N mercurous nitrate and physically developed for minutes in a solution which contained 0.5% rnetol', 2% citric acid and 0.2% silvernitrate.
• the sensitivity of the foil without citric acid was taken to be equal to 100, that of the foil containing citric acid equalled 115. If the foil were treated within hour after the exposure of the mercurous nitrate solution, the sensitivity with the foil without citric'acid had fallen to 10 and with that with citric acid to 100 and after 1 hour to 85.
• Example II A foil of the kind used in Example I was sensitised using a solution containing 0.2 mol. p-ethoxy benzene diazosulphonic acid-sodium and 0.1 mol. zinc acetate per liter, of water and then dried. The following exposure, treatment and development were effected as described in Example I. If a foil without zinc acetate were treated with the mercurous nitrate solution immediately after exposure or within A and 1 hour thereafter, the sensitivity was 100 (arbitrarily taken to be 100), 50 and respectively, Whereas those with zinc acetate were 120, 100 and 100 respectively.
• Example III A foil as used in Example I was sensitised with a solution containing 0.2 mol. p-methoxy benzene diazosulphonic acid sodium and 0.2 mol. resorcinol per liter of water and then dried. The photo-sensitive foil thus obtained was exposed, treated. and developed as described in Example I. When the foil was stored for 0, A and 1 hour after exposure and then treated with the mercurous salt solution, the sensitivity expressed in terms of the scale of Example I was 60, 35 and respectively.
• Example A foil as used in Example I was sensitised with a solution containing 0.2 mol. p-methoxy benzene diazosulphonic acid sodium and 0.1 mol. naphthalene trisulphonic acid per liter of water, then dried and subsequently exposed treated and developed as described in Example I.
• the sensitivity (expressed in terms of the scale of Example I) was when the foil was treated with the mercurous nitrate solution immediately, A and 1 hour respectively after the exposure; 115, 80 and 50 respectively.
• Example Vl Paper was sensitised with a solution containing 0.2 mol. p-methoxy benzene diazosulphonic acid sodium and 0.1 mol. naphthalene bisulphonic acid-Pb per liter of water then dried and subsequently exposed, treated and developed for 5 minutes as described in Example I. If the sensitivity of paper without naphthalene bisulphonic acid'Pb and treated and developed immediately after exposure is arbitrarily taken to be equal to 100, it was after a time interval of A hour between exposure and treatment: and after 1 hour: 10.
• the sensi- 6 tiveness (expressed in the same scale) are 50, 50 and 40 respectively.
• Example VII A foil as used in Example I was sensitised with a solution of 52 g. chloro-Z methyl-4 benzene diazosulphonic acid sodium and 20 g. ammonium tungstenate in ccm. of water.
• the sensitivity of a foil which does not contain ammonium tungstenate and which, immediately after the exposure, is subjected to the action of a mercurous salt solution is arbitrarily taken to be-equal to 100, it will have fallen to 60 after A hour between exposure and aftertreatment and to 20 after 1 hour.
• ammonium tungstenate was provided, the sensitivity with immediate after-treatment was 200, after hour 200 and after 1 hour 150, and the maximum blackening was considerably higher.
• Example IX A foil as used in Example I was sensitized with a solution containing 0.2 mol. dimethoxy-3,4 benzene diazosulphonic acid sodium-l and 0.1 mol. benzene sulphonic acid lead per liter of water and then dried.
• Example II The subsequent exposure, after-treatment and development were efiected as in Example I. If the sensitivity of the foil without the antiregression agent is arbitrarily taken to be 100 in the case of an after-treatment following immediately after-exposure, it was after 4 hour between exposure and after-treatment 35.
• Example X A foil as used in Example I was sensitized with a solution containing 0.2 mol. p-rnethoxy benzene sulphonic acid sodium and 0.1 mol. cadmium lactate per liter of water and then dried.
• the sensitivity of the foil, treated with the mercurous nitrate solution immediately after exposure was, expressed in terms of the scale of Example I, 230; after /4 hour and 1 hour between exposure and after-treatment 170 and respectively.
• a method of producing photographic contrasts which comprises the steps of selectively exposing portions of a light-sensitive system containing a light-sensitive diazosulphonate and an antiregression agent other than said diazosulphonate consisting of a Water-soluble salt of a metal selected from the group consisting of lead, lanthanum, thorium, uranium, cadmium, zinc, copper, cobalt and chromium, to decompose said diazosulphonate and form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physicallyintensifiablecontrast?"
• a method of producing photographic contrasts form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts which comprises the steps of selectively exposing 'portions of a light-sensitive system containing a light-sensitive diazosulphonate and an antiregression agent other than said diazosulphonate consisting of a water-soluble salt of cadmium, to decompose said diazosulphonate and form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts which comprises the steps of selectively exposing portions of a light-sensitive system containing a light-sensitive diazosulphonate and an antiregression agent other than said diazosulphonate consisting of a water soluble salt of zinc, to decompose said diazosulphonate and form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble which comprises the steps of selectively exposing portionsof a light-sensitive system containing a' light-sensitive diazosulphonate and an antiregressionagent consisting of zinc acetate, to decompose said diazosulphonate and form a stable light decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts which comprises the steps of selectively exposing portions of a light-sensitive system containing a light-sensitive mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts which comprises the steps of selectively exposing portions of a light-sensitive system containing a light-sensitive diazosulphonate and an antiregression agent other than said diazosulphonate consisting of a water soluble salt of lead, to decompose said diazosulphonate and form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts which comprises the steps of selectively exposing portions of a light-sensitive system containing a light-sensitive diazosulphonate and an antiregression agent other than said diazosulphonate consisting of a water soluble salt of copper, to decompose said diazosulphonate and form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts which comprises the steps of selectively exposing portions of a light-sensitive system containing a light-sensitive diazosulphonate and an antiregression agent consisting of chromic acetate, to decompose said diazosulphonate and form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts which comprises the steps of selectively exposing portions of a light-sensitive system containing a light-sensitive diazosulphonate and an antiregression agent other than said diazosulphonate consisting of a lead salt of an aromatic sulfonic acid to decompose said diazosulphonate and form a stable light-decomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.
• a method of producing photographic contrasts which comprises the steps of selectively exposing portions of a light-sensitive system containing a light-sensitive diazosulphonate and an antiregression agent consisting of a lead salt of napthalene bisulfonic acid, to decompose said diazosulphonate and form a stable lightdecomposition product and subjecting said light-decomposition product to the action of a soluble mercurous salt in the presence of moisture to form a physically intensifiable contrast.

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• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

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• 0
  • US US2735773D patent/US2735773A/en not_active Expired - Lifetime
  • BE BE510182D patent/BE510182A/xx unknown
  • NL NL7415258.A patent/NL160094B/xx unknown
  • NL NL77917D patent/NL77917C/xx active
• 1952
  • 1952-03-23 DE DEN5254A patent/DE921245C/de not_active Expired
  • 1952-03-24 GB GB7512/52A patent/GB748172A/en not_active Expired
  • 1952-03-25 FR FR1062459D patent/FR1062459A/fr not_active Expired
  • 1952-03-25 CH CH307649D patent/CH307649A/de unknown
  • 1952-03-25 CH CH309212D patent/CH309212A/de unknown

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