Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D263/00—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings
  • C07D263/52—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings condensed with carbocyclic rings or ring systems
  • C07D263/54—Benzoxazoles; Hydrogenated benzoxazoles
  • C07D263/58—Benzoxazoles; Hydrogenated benzoxazoles with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached in position 2
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C391/00—Compounds containing selenium
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D277/00—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings
  • C07D277/02—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings not condensed with other rings
  • C07D277/20—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D277/32—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D277/00—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings
  • C07D277/60—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings condensed with carbocyclic rings or ring systems
  • C07D277/62—Benzothiazoles
  • C07D277/68—Benzothiazoles with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached in position 2
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D293/00—Heterocyclic compounds containing rings having nitrogen and selenium or nitrogen and tellurium, with or without oxygen or sulfur atoms, as the ring hetero atoms
  • C07D293/10—Heterocyclic compounds containing rings having nitrogen and selenium or nitrogen and tellurium, with or without oxygen or sulfur atoms, as the ring hetero atoms condensed with carbocyclic rings or ring systems
  • C07D293/12—Selenazoles; Hydrogenated selenazoles
• • 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
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/492—Photosoluble emulsions

Definitions

• the unreduced silver remaining after development has been removed by silver halide solvents or rendered insensitive or transparent by treatment with complexing agents.
• Optional after-treatments include intensification and reduction, toning and tinting.
• the primary or first step in image formation always has been based on the selective reduction step.
• the objects of this invention are realized by new silver halide compositions in which an image may be formed, after exposure to actinic radiation, by imagewise solution of the silver halide.
• the residual silver halide image may then be converted to silver, dyed or toned images.
• novel photographic compositions and silver halide layers of this invention comprise silver halide crystals which have been treated, in substantially greater than fog inhibiting amounts, with a selected N-acylamino thiophenol having at least one form which can be represented by the formula wherein R is a hydrocarbon radical and whose silver salt is less soluble in water than silver chloride.
• These compounds are characterized in that when admixed with an aqueous silver halide dispersion it protects the silver halide crystals to such an extent that when a silver halide dispersion protected by said compound is treated with 10%, by weight, aqueous sodium thiosulfate, at least three times the amount of silver halide remains undissolved as in a similar dispersion successively treated with aqueous sodium hypochlorite and aqueous sodium thiosulfate, after vigorous agitation of the dispersions for 30 seconds at 25 C. The dispersion so successively treated clears, whereas the other dispersion remains turbid.
• thesilver halide crystals are dispersed in a Water-permeable organic colloid to form a light-sensitive photographic emulsion.
• the selected thiophenol can be added to the silver halide emulsion while the latter is in the liquid state or the emulsion may be coated on a suitable support and the resulting element bathed or impregnated with a solution, e.g., an alcoholic solution Still further objects will be ap- Patented Nov. 3, 1964 of the thiophenol.
• the amount of thiophenol in the silver halide emulsion is from about 0.4 to 25 g.
• the gelatimsilver halide ratio is quite flexible varying from 3:1 to 1:30 depending on the particular organic compound and application.
• the silver halide is present in much higher concentration than in conventional emulsions and emulsion layers.
• direct positive images are formed by a process which comprises (a) Exposing imagewise to actinic radiation a photo sensitive layer comprising silver halide crystals treated with the organic compound as described above,
• the silver halide image may be viewed directly, e.g., by projection (if on a transparent support) or it may be intensified by i v (d)
• a fogging developer e.g., a high pH, 1- phenyl-4-methyl-3-pyrazolidone/hydroquinone developer containing iodide ion or by fogging the emulsion by exposure to light and then treating with a silver halide reducing agent, e.g,, a conventional silver halide developer, and
• the imagewise solution of the exposed silver halide/ thiophenol stratum may be elfected by the silver halide solvents commonly used as photographic fixing agents, e.g., sodium thiosulfate, sodium thiocyanate, concentrated solutions of potassium bromide, etc.
• Reduction of the treated, residual silver halide may be accomplished by use of any chemical reducing agent capable of reducing silver ion to silver metal, e.g., hydroquinone, metol, sodium hydrosulfite and stannous chloride.
• the function of the reducing agent may be enhanced by modifying the surface properties of the treated, residual silver halide crystals by means of alcohol, thiourea, potassium iodide, etc.
• the silver halide image may be.
• color images may be obtained by developing the treated, residual silver halide with a primary aromatic amine color developing agent in the presence of a color coupling compound either in the developing bath or previously incorporated in the emulsion.
• test A the candidate thiophenol must render a dispersion of silver halide crystals insoluble in a silver halide solvent, i.e., an aqueous solution of sodium thiosulfate, at some pH between 1 and 13.
• the candidate compound elfects the insolubility required of Test A, it must also, to meet the requirements of Test B by forming with said dispersion of silver halide crystals a reaction product which, upon treatment with an aqueous solution of sodium hypochlorite, becomes soluble when subsequently treated with aqueous sodium thiosulfate.
• the following practical tests are provided in further exemplification of the invention and include specific concentrations of solutions, times, etc., so that suitable organic compounds may be readily and positively identified.
• a solution nearly saturated at 25 C. with a candidate organic compound is prepared using ethanol, acetone, dimethyl formamide, water or other suitable solvents. Depending on the solubility, a solution concentration from 0.01 to percent by weight is obtained. Twentyfive m1. of a silver chlorobromide dispersion containing mg. of silver halide (calculated as silver bromide), prepared as described below, is treated with small increments (i.e., about 0.1 to 0.2 m1. at a time) of the said candidate solution under safelight conditions (Wratten 1A red filter or equivalent) until the silver halide dispersion either is rendered insoluble in 10% aqueous sodium thiosulfate or the candidate is found not to cause insolubilization.
• safelight conditions Wratten 1A red filter or equivalent
• insolubilization will occur upon the addition of 0.05 g. or less of said candidate compound, calculated as the pure compound. Compounds which must be used in substantially greater quantities than this, e.g., 1-2 g. to effect insolubilization are considered less preferred compounds.
• the silver halide dispersion insolubility is determined by taking a 0.5 ml. portion of the silver halide dispersion (after each incremental addition of the candidate organic compound), adding about 0.1 to 0.2 ml. of 10% aqueous sodium thiosulfate solution and observing the turbidity after seconds.
• This test may be repeated for various pH increments from 1 to 13. Although there is some optimum pH value at which the test is most sensitive, this is not a sharp maximum which must be precisely attained. Rather, it has been found that there is a fairly broad range of pH values (e.g. 2.0 to 3.0 pH units) over which the test has a satisfactory sensitivity.
• the silver halide dispersion might be tested without adjustment (e.g. at pH 5.0 to 7.0) and if insolubilization occurs here, Test A is completed. If there is no insolubilization, the test is repeated at a higher pH (e.g., about pH 1l-13).
• TEST B An organic compound capable of insolubilizing a silver halide dispersion according to Test A is now ready for the next test, which again will be conducted under safelight conditions.
• To the above silver halide dispersion there is added the minimum amount of a solution of the candidate organic compound found necessary for insolubilization.
• Half-milliliter samples of the dispersion containing 0.5 mg. AgBr or 0.29. mg. Ag are placed in two test tubes. To one sample is added 0.5 ml. of water; to the other is added 0.5 ml. of a 5% by weight aqueous solution of sodium hypochlorite (containing 25 mg. sodium hypochlorite). Next, there is added to both samples, 1.0 ml.
• the silver halide dispersion disclosed in Tests A and B is prepared according to the following specifications. In red light, 30 g. of photographic grade gelatin is soaked in 1100 ml. of distilled water for 10 minutes. The temperature is then raised to 120 F. and g. of solid ammonium chloride added. The mixture is stirred at F. and after the ammonium chloride is completely dissolved, a solution made by diluting 500 ml.
• N-acylaminothiophenols of the wherein R is a hydrocarbon radical are those which form silver salts of the formula:
• useful silver salts of the above formula are those which are insoluble in aqueous ammonium hydroxide at pH 12.
• Dispersed crystals of silver halide, treated with an appropriate amount of a suitable N-acylaminothiophenol are affected by exposure of a portion of said crystals to actinic radiation, e.g., ultraviolet, visible, infrared, X- radiation, etc., to such an extent that at least 20% of the less soluble crystals remain when 90% of the more soluble crystals dissolve when treated in 10% by weight aqueous sodium thiosulfate solution.
• actinic radiation e.g., ultraviolet, visible, infrared, X- radiation, etc.
• solubilizing groups in the R portion of the above formula should be avoided in order that reaction products with silver halide will be formed which will significantly reduce the solubility of silver halide grains in silver halide solvents.
• the silver halide need not be a combination of silver chloride and silver bromide, but may be silver chloride, silver bromide and other mixed halide systems conventional in photographic practice, e.g., silver bromoiodide. While, for rapid processing, a high silver halide to hinder ratio is preferred, more conventional ratios can also be used.
• water-permeable organic colloid binding agents can be used and in some cases such binders can be used alone.
• Such agents include water-permeable or water-soluble polyvinyl alcohol and its derivatives, e.g., partially hydrolyzed polyvinyl acetates, ethers and acetals containing a large number of intralinear CH CHOH groups, hydrolyzed interpolymers of vinyl acetate and unsaturated addition polymerizable compounds such as maleic anhydride, acrylic and methacrylic acid esters and styrene.
• Suitable such colloids of the last-mentioned type are disclosed in US.
• Patents 2,276,322; 2,276,323 and 2,397,- 866 The useful polyvinyl acetals include polyvinyl acetaldehyde acetal, polyvinyl butyraldehyde acetal and polyvinyl sodium o-sulfobenzaldehyde acetal.
• Other useful colloid binding agents which can be used include the poly-N-vinyllactams of Bolton US.
• Patent 2,495,918 various polysaccharides, e.g., dextran, dextrin, etc., the hydrophilic copolymers in Shacklett US.
• Patent 2,833,- 650 hydrophilic cellulose ethers and esters, and polymers of acrylic and methacrylic esters and amides. Also, it hasbeen found practical to treat silver halide layers on a base material in the essential absence of a binder, e.g., by chemical or vacuum deposition.
• the emulsions may optionally contain any of the usual adjuvants customarily employed in silver halide systems so long as they do not interfere with the adsorption and complexing action of the essential ingredient of the essential ingredient of the invention.
• the emulsion can be coated on any suitable support, e.g., cellulose esters, cellulose mixed esters; superpolymers, e.g., polyvinyl chloride (co) vinyl acetate, polyvinyl acetals, butyrals; polystyrene; polyamides, e.g., polyhexarnethylene adipamide, polyesters, e.g., polycarbonates, polyethylene terephthalate, polyethylene terephthalate/isophthalate, esters formed by condensing terephthalic acid and its derivatives, e.g., dimethyl terephthalate with propylene glycol, diethylene glycol, tetramethylene glycol, cyclohexane-l,4-dimethanol (hexahydro-p-xyiene dialcohol); paper, metal, glass, etc.
• suitable support e.g., cellulose esters, cellulose mixed esters; superpolymers, e.g.
• the desirable concentration of the selected organic compound depends on many factors such as the size and solubility of the organic compound, the nature of its reaction with silver halide, the size and nature of the silver halide crystals, thee presence of other materials which may react with or be adsorbed to the surface of the silver halide, etc.
• Example 1 a number of organic compounds are disclosed which were tested in a dispersion of silver halide crystals wherein the average grain size was 035 (micron) in diameter, therefore about 0.043 t in volume, assuming cubic grains.
• the silver halide comprised 70 mole percent silver chloride and 30 mole percent silver bromide, with a specific density of about 5.7 g./cc.
• a particularly preferred thiophenol is 4-i-butyrylaminothiophenol. Assuming that a single molecule of this compound could occupy an area of square angstrorns, it would require 1.5 l0 molecules to occupy a molar surface area of silver halide. With a molecular weight of 195, this would require 1.5 10 l9o O.50 g.
• Example II it required 210x10 g. of 4-ibutyrylaminothiophenol to insolubilize 2.5 10- g. of silver halide of average molecular Weight 157. Therefore according to experimental data (test tube results) it would require of this thiophenol to insolubilize one mole of the silver halide. More significantly, as disclosed in Example II in a photographic emulsion coated on a film base support, it was found that 0.4 g. of the same thiopheno-l per mole of silver halide gave optimum results. This compares more closely with the theoretically determined amount of 4-i-butyrylaminothiophenol required to cover the silver halide surface.
• Elements suitable for this novel process can also be prepared by bathing a photographic film in a solution of an appropriate acylaminothiophenol.
• the silver halide crystals near the surface of the coated emulsion stratum are in contact with a higher concentration of the thiophenol. Crystals farther from the surface, are treated with less of this organic compound and, if the rate of diffusion is sufliciently slow, there may be considerably less of the compound (even approaching zero) reacting with the lower silver halide crystals than with the surface silver halide crystals.
• satisfactory results might be obtained with only a fraction, e.g., one-half, of the amount of the organic compound theoretically calculated as required to just cover the surface of a mole of the silver halide crystals.
• the N-acylaminothiophenols used in accordance with this invention can be made by reacting the corresponding acid chloride with the aminothiophenol, e.g., p-aminothiophenol dissolved in pyridine by slowly adding the acid chloride at a temperature between 5 C. and 10 C. with stirring and allowing the mixture to stand about 24 hours. The mixture is then poured into 1 liter of crushed ice containing 250 m1. concentrated HCl and 250 ml. water, the mixture is stirred vigorously, allowed to stand for about 5-10 minutes to ripen the crystals, which are washed with water until free of acid, dried and recrystallized from methanol. Typical crystals have the melting points given in the following tables.
• Tests A and B have been described earlier as procedures whereby one can determine whether or not a given N-acylaminothiophenol is suitable for use according to the process of this invention. Some of the compounds which were indicated as suitable according to the screening procedures of both tests, have been incorporated into actual photographic coatings and good results have been obtained. Below there are listed a number of thiophenols which were tested in this manner in cluding one of the compounds which has been found to be inoperable. The inoperable compound shown failed to produce the insolubility required of Test A and was therefore not subjected to further testing.
• Test C a simulated photographic test has been devised and is designated as Test C.
• the test is believed to be completely adequate in that any compound which is found suitable according to the photoexposed to the lamp for up to minutes.
• TEST C A 0.5 ml. portion of the insolubilized dispersion prepared in Test A under safelight conditions is placed in a 12 x 75 mm. Pyrex test tube three inches from a No. 2 reflectoflood lamp.
• This insolubilized dispersion is A control consisting of another 0.5-ml. portion of the insolubilized silver halide dispersion from Test A is taken under safelight conditions. Two-tenths of a milliliter of 10% aqueous sodium thiosulfate is added to each of the dispersion samples taken and compared under safelight conditions. Any reduction in turbidity of the dispersion exposed to the reflectoflood lamp compared to the unexposed control after treatment with aqueous sodium thiosulfate solution shows that photosolubilization occurs.
• Tests A, B and C were all conducted using Silver Halide Dispersion I, the preparation of which was given immediately following the description of the procedure for Test B.
• the qualitative procedure of Test A was repeated in a more quantitative manner, using a ripened, washed and redispersed (but not chemically sensitized) gelatino-silver chlorobromide emulsion as described in Example I of assignees copending application, Nottorf, U.S. Serial No. 94,989, filed March 13, 1961.
• Dispersion II This emulsion is designated in the table below as Dispersion II and was made as follows: A lithographic emulsion having a silver halide composition of 30 mole percent AgBr and 70 mole percent AgCl and having grams of gelatin present per mole of silver halide for the steps of precipitation and ripening was freed of unwanted, soluble, by-product salts by a coagulation and wash procedure as taught in Waller et al. US Patent 2,489,341, wherein the silver halide and most of the gelatin were coagulated by an anionic wetting agent, sodium lauryl sulfate, using an acid coagulation environment. Following the washing step, the emulsion coagulate was redispersed in water together with 47 grams of additional bulking gelatin.
• N-Acylaminothiophenols of silver halide was applied at a coating Weight of 46 mg. of silver per square decimeter on 0.004 inch thick polyester photographic film base (with a sublayer to provide proper adhesion) as described in Example IV of Alles, U.S. Patent 2,779,684.
• the coating after imagewise exposure, showed a gerater rate of fixing in an 0.5 molar aqueous solution of sodium thiosulfate in exposed areas than in the unexposed areas so as to form a positive silver halide image.
• Solublem- EXAMPLE II An emulsion as described in Dispersion 11, Example I was redispersed in a 5% gelatin solution which contained 47 g. gelatin per mole of the silver halide. A pH 6.0:.1 was maintained while dispersing 10 min. at F. The emulsion was brought to 2320 g. by addition of water and the temperature adjusted to F. Four-tenths of a gram of 4-i-butyrylaminothiophenol was added per mole of silver halide from a 1% by weight ethanol solution.
• Chrome alum hardener was added and the emulsion was diluted with water to a total weight of 2334 g. per mole latter amounts constitute the maximum quantity that provides low fog without serious loss in speed and photographic quality. For this reason it is not practical to use photosoluble elements in place of ordinary silver halide photographic materials. When photosoluhle elements are exposed and processed normally, development proseeds slowly and incompletely to give a negative silver image having much less speed and lower density. In addition, fixing is slower and may be incomplete for practical fixing times. Thus, photosoluble elements require longer conventional processing times and give slower speed, in-
• novel photographic compositions of this invention have numerous advantages.
• a primary advantage is the simplicity of their preparation. They can be exposed and processed to images under ordinary room light conditions.
• the photographic processes applicable to the compositions and elements of the invention likewise have advantages over previously known systems based on selective reduction of exposed silver halide for forming either direct positive or negative images without resorting to the special efiiects and sensitizing procedures previously used for preparing such images.
• this present process is not limited to the use of certain photographic developing agents but may be accomplished by using a wide range of reducing agents. Many such compounds are of very low cost and can be used to form images of much higher covering power than customary, thus effecting important economies in processing, as well as greatly increasing the efliciency of the silver image with a resultant increase in sensitivity.
• compositions and elements of this invention may be processed to form silver halide or silver images without the requirement of special equipment but instead conventional equipment and apparatus can be used.
• a further advantage is that the processes can be carried out successfully by photographic technicians and photographers of ordinary skill.
• a still further advantage is that the processes utilize conventional reducing agents, e.g., developers and fixing agents. Still additional advantages will be apparent from the above description of the invention.
• a photographic silver halide emulsion before exposure to actinic radiation comprising silver halide crystals having associated therewith in substantially greater than fog-inhibiting amount a 4-N-acylaminothiophenol, the silver salt of said thiophenol being of lower solubility in water than silver chloride and less soluble in 10% aqueous sodium thiosulfate than untreated silver halide crystals at a predetermined pH, said 4-N-acylaminothiophenol being present in such an amount, in terms of the ratio of its weight to the surface area of the silver halide crystals, that when admixed in such ratio with an aqueous silver chlorobromide dispersion, 70/30 mole percent, gelatin dispersion containing 0.29 mg.
• acyl radical in said thiophenol is a saturated aliphatic acyl radical of 3 to 13 carbon atoms.
• a photographic element comprising a support bearing a layer of a silver halide emulsion before exposure to actinic radiation comprising silver halide crystals having associated therewith in substantially greater than foginhibiting amounts a 4-N-acylaminothiophenol, the silver salt of said thiophenol being of lower solubility in water than silver chloride and less soluble in 10% aqueous sodium thiosulfate than untreated silver halide crystals at a predetermined pH, said 4-N-acylaminothiophenol being present in such an amount, in terms of the ratio of its weight to the surface area of the silver halide crystals, that when admixed in such ratio with an aqueous silver chlorobromide dispersion, /30 mole percent, gelatin dispersion containing 0.29 mg.
• An element according to claim 6 wherein the emulsion is gelatin emulsion and the silver halide is silver chlorobromide and the gelatin/silver halide ratio is 3:1 to 1:30, by weight.

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• Physics & Mathematics (AREA)
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• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Thiazole And Isothizaole Compounds (AREA)

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  • FR FR89467D patent/FR89467E/fr active Active
• 1962
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