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
  • G03C1/494—Silver salt compositions other than silver halide emulsions; Photothermographic systems ; Thermographic systems using noble metal compounds
  • G03C1/498—Photothermographic systems, e.g. dry silver
  • G03C1/49836—Additives
  • G03C1/49845—Active additives, e.g. toners, stabilisers, sensitisers

Definitions

• This invention relates to photosensitive heatdevelopable dry silver sheet materials and has particular reference to improved means for obtaining images of desirable density and color.
• Photosensitive heat-developable dry silver sheet materials contain a photosensitive silver halide catalyst-forming means in catalytic proximity with a heatsensitive combination of organic silver salt and reducing agent.
• the reducing agent is a hindered phenol, it is found. desirable to include an image intensifier or toner material, of which phthalazinone has been an outstanding example.
• Phthalazinone and various other materials have previously been employed as toners in light-stable heatsensitive copy-sheets based on organic silver salts and reducing agents.
• Phthalazinone is a preferred material in compositions shown in U.S. Pat. No. 3,080,254; other materials therein disclosed, such for example as imidazole, must be employed in much larger amounts and are generally less effective.
• Both phthalic acid and phthalazinone areshown in U.S. Pat. No. 3,218,166 to be effective toners for heat-sensitive compositions'containing organic silver salts and hindered phenolic reducing agents.
• Phthalic acid may effectively be replaced in whole or in part by corresponding molar amounts of naphthalene-2,3-dicarboxylic acid or of o-phthalamic acid. Each of these compounds will be seen to be capable of condensation to form a five-membered heterocyclic ring structure.
• substituted imidazoles having the S-membered heterocyclic imidazole ring strucparts by weight of phthalic acid and about 15 parts by.
• the coating made with the half soap, containing 14.5 percent silver may be shown by calculation to contain 0.44 mole of phthalic acid and 0.73 mole of imidazole per mole of silver.
• the transparent coating containing the full soap may be shown to contain 0.18 mole of phthalic acid and 0.057 mole. of benzimidazole per mole of silver. More broadly, it has been foundipossible to obtain distinct improvement in imageappearance with dry silver coatings based onv organic. silver. salts and hindered phenolic reducingagents by incorporating as toner materials animidazoleand;phthalic acid orequivalent in amounts within the.
• silver half-soaps For use on paper or other non-transparent backings it is found convenient to use silver half-soaps, of which an equimolar. blend of silver behenate and behenic acid, prepared by precipitation from aqueous solution of the sodium salt of commercial behenic acid andanalyzing about 14.5 percent silver, represents a preferred example.
• Other components suchfor example as colorings, opacifiers, extenders, spectral sensitizing-dyesetc. may be incorporated as required for various specific purposes.
• a second composition is prepared by first mixing together acetone 339.9 grams methanol 1 18.5 cellulose acetate 25.0 colloidal silica 3.5
• the mixture is applied over the previous layer and dried.
• the dry coating weight is 2.7 grams/sq.m.
• the spectral sensitizer is l-methyl-3-allyl-5[ (3-ethyl-2- benzoxazolinylidene) ethylidine]-2-thiohydantoin.
• the molar ratios of phthalic acid and imidazole to total silver are 0.37 and 0.71 respectively.
• EXAMPLE 2 A homogenate is prepared of silver behenate full soap gm. methyl isobutyl ketone 54 I toluene methyl ethyl ketone To 72 grams of the homogenate is added acetone acetone mercuric bromide (as .5% soln. in methanol) .0045
• the vinyl resin is a copolymer, of vinyl acetate and vinyl chloride, containing hydroxyl radicals.
• the Sudan yellow dye is optional
• the mixture is prepared under darkroom conditions.
• a second composition is prepared using toluene 34 gm. methyl ethyl ketone 32 methanol 22 vinyl chloride-vinyl acetate copolymer 6 tetrachlorophthalic anhydride .43 phthalic acid 2.2 benzimidazole .43 phenolic reducing agent of Example 1 3.42 antistatic agent (optional) ("Catanac SN") .43
• the molar ratios of phthalic acid and benzimidazole to total silver are 0.167 and 0.046 respectively.
• the film is exposed through a 0-4 continuous wedge to illumination from a carbon arc and developed by holding for 30 seconds in a bath of inert fluorocarbon liquid maintained at 260F.
• the sensitometric values attained are:.
• a photosensitive heat-developable sheet material having an image-forming stratum comprising (1) photo-sensitive silver halide catalyst-forming means and (2) heat-sensitive reactant image-forming means including an organic silver salt oxidizing agent and a hindered phenolic reducing agent for silver ion, the oxidation-reduction reaction of which to produce a visible change is accelerated by said catalyst, and (3) as sifier material consists of phthalic acid and imidazole.
• Sheet material of claim 3 wherein said image intensifier material consists of phthalic acid and benzimidazole.

Landscapes

• 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)
• Heat Sensitive Colour Forming Recording (AREA)

Priority Applications (15)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23283871

Family Applications (1)

Country Status (15)

Cited By (31)

Families Citing this family (6)

Citations (3)

• 1973
  • 1973-02-02 US US00329107A patent/US3847612A/en not_active Expired - Lifetime
• 1974
  • 1974-01-01 AR AR252176A patent/AR207001A1/es active
  • 1974-01-16 CA CA190,312A patent/CA1009888A/en not_active Expired
  • 1974-01-23 ES ES422553A patent/ES422553A1/es not_active Expired
  • 1974-01-23 NL NLAANVRAGE7400911,A patent/NL175857C/xx not_active IP Right Cessation
  • 1974-01-23 SE SE7400848A patent/SE385741B/xx not_active IP Right Cessation
  • 1974-01-31 BR BR716/74A patent/BR7400716D0/pt unknown
  • 1974-02-01 IT IT48105/74A patent/IT1008189B/it active
  • 1974-02-01 GB GB488774A patent/GB1441477A/en not_active Expired
  • 1974-02-01 DE DE2405431A patent/DE2405431C3/de not_active Expired
  • 1974-02-01 FR FR7403389A patent/FR2216602B1/fr not_active Expired
  • 1974-02-01 JP JP49013571A patent/JPS525845B2/ja not_active Expired
  • 1974-02-01 CH CH143274A patent/CH607094A5/xx not_active IP Right Cessation
  • 1974-02-01 PH PH15469A patent/PH10823A/en unknown
  • 1974-02-01 BE BE140479A patent/BE810522A/xx not_active IP Right Cessation

Patent Citations (3)

Also Published As

Similar Documents