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
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/04—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with macromolecular additives; with layer-forming substances
  • G03C1/053—Polymers obtained by reactions involving only carbon-to-carbon unsaturated bonds, e.g. vinyl polymers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/136—Coating process making radiation sensitive element

Definitions

• a process for quick drying a "gelatino, silver halide photographic emulsion wherein the halide of said silver halide is predominantly bromide said process comprises combining a liquid gelatino emulsion of said silver halide with a synthetic polymeric binder which is compatible with gelatin and which has a glass transition temperature of less than 20 C., and removing substantially all liquid from said emulsion in less than about six minutes.
• Typical synthetic polymers useful in the invention are copolymers of ethylenically unsaturated monomers such copolymers containing units of alkyl acrylates and the like.
• This invention relates to processes for drying photographic, gelatino, silver halide emulsions.
• this invention relates to a process of decreasing the drying time of a silver halide emulsion' without increasing the fog inherent in many silver halide gelatin emulsions when quickly dried.
• this invention relates to a process for quick drying a gelatino, silver halide emulsion without a substantial increase in fog by combining at least by weight based on the total binder vehicle, of a synthetic polymer with said emulsion and then removing liquid from the emulsion.
• Photographic manufacturers are constantly seeking faster methods for coating and drying photographic emulsions.
• faster coating and drying procedures are accompanied by a serious fog buildup in the coated product.
• This problem is especially prevalent in high-speed silver halide emulsions in which the halide is predominantly bromide.
• silver halide emulsions containing gelatin as the sole silver halide vehicle are rapidly dried after coating, the fast shrinkage of the gelatin apparently causes pressure on the silver halide grains which produces anover-all fog upon chemical development.
• a synthetic polymer is added to a silver halide emulsion.
• the resulting emulsion can be set by a chilling or by chemical setting, such as disclosed in Jones US. Pat. 2,652,345 issued Sept. 15, 1953.
• the emulsion layer is then subjected to conditions such as Warm air blasts of sufficient temperature and velocity to rapidly dry the emulsion layer in less than 6 minutes and preferably in 4 /2 minutes or less.
• the emulsion layer is considered dry when substantially all of the carrier liquid has been removed, i.e. about 15% or less carrier liquid in the emulsion. In essence, the gelatino emulsion!
• the emulsion is dry when it contains less than about 15% moisture by weight, based on the total emulsion; it is then no longer tacky and can be easily handled without damaging the emulsion layer.
• the emulsion is generally not dried to eliminate all moisture as it would prohibit subsequent liquid diffusion in the chemical development steps.
• the process finds particular use in drying silver halide emulsions in which the halide is predominantly bromide
• the emulsions contain silver halides in which the halide is at least bromide; in particular chemically sensitized silver bromoiodide emulsions are preferred in the process.
• the preferred emulsions of the process can be generally characterized as being high-speed emulsions and in the preferred embodiments the process is used for drying high-speed negative films, reversal films, medical X-ray films, and the like.
• these emulsions can be sensitized with selenium, sulfur, tellurium, and the like, either alone or in combination with noble metal sensitizers such as gold salts or gold compounds.
• a wide variety of synthetic polymers can be used in the process.
• the polymers are copolymers of ethylenically unsaturated monomers, said polymers being compatible with gelatin and having a glass transition temperature (Tg) of less than 20 C.
• Tg glass transition temperature
• Particularly good polymers for use with silver bromide emulsions are the latex polymers which are relatively insoluble in Water.
• solution polymers which are more soluble in water do allow fast drying times without the fog buildup associated with an all gelatin vehicle in the emulsion.
• the non-gelatin vehicles or synthetic polymers added to the emulsion according to this invention comprise co polymers having units of alkyl acrylates.
• alkyl acrylates which may be used in making the copolymers are methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylates (e.g., n-butyl or t-butyl acrylate), amyl acrylates, hexyl acrylates and the like.
• Alkyl acrylate copolymers containing units of acrylic acid are especially useful in the process.
• Typical polymers of this type are copoly(butyl acrylate-acrylic acid), copoly(methyl acrylate-acrylic acid), copoly(ethyl acrylate-acrylic acid), and the like.
• the copolymer comprises less than 30 mole percent acrylic acid; especially good results are obtained with latex alkyl acrylate copolymers having less than mole percent acrylic acid.
• Alkyl acrylates having units of sulfoester acrylates are also very useful in this invention.
• Typical polymers of this type are copoly(methyl acrylate-sulfopropylacrylate), copoly(ethyl acrylate-sulfopropyl acrylate) and the like. In this embodiment good results are likewise obtained when the copolymer comprises less than 30 mole percent sulfoester units and preferably less than 20 mole percent sulfoester units.
• the above-mentioned copolymers contain units of a third monomer.
• the synthetic polymers comprise units of (1) alkyl acrylates, (2) acrylic acid or sulfoester acrylates, and (3) an acrylic monomer unit having active methylene groups in side chains such as in malonic ester groups, acetoacetic ester groups, cyanoacetic ester groups or 1,3-diketone groups.
• Typical polymers of this class include copoly(ethyl acrylateacrylic acid 2 acetoacetoxy ethyl methacrylate), copoly(butylacrylate-sodium acryloxy propane sulfonate- 2-acetoacetoxyethyl methacrylate), copoly(methyl acrylate-sodium acryloyloxypropane sulfonate 2-acetoacetoxyethyl methacrylate), copoly(butyl acrylate-acrylic acid 2 cyanoacetoxyethyl methacrylate) and the like.
• copolymers of (1) alkyl acrylates and (2) acrylic acid or the sulfoester can also contain units of (3) sulfobetaines.
• Typical copolymers having sulfobctaine units include copoly(butyl acrylate-acrylic acid-4,4,9-trimethyl-8-oxo 7 oxa 4 azonia-9-decene-l-sulfonate), and the like.
• the synthetic polymer generally comprises at least 10 percent and to about 99 percent of the binder vehicle for the emulsion.
• the binder vehicle for the emulsion comprises from about percent to about 75 percent synthetic polymer and from about 75 percent to about 25 percent gelatin by weight of the total binder.
• the emulsion comprises less than 100 grams of gelatin per mole of silver halide in the emulsion.
• the emulsion comprises less than 75 grams of gelatin per mole of silver halide.
• the light-sensitive compositions described herein can be coated on a wide variety of supports in practicing this invention.
• the photographic silver halide grains can be coated on one or both sides of the support which is preferably transparent and/or flexible.
• Typical continuous supporting sheets include, for example, cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film and other polyester film as well as glass, paper, metal, wood, and the like.
• Supports such as paper can be coated with alpha-olefin polymers, particularly polymers of alphaolefins Containing two or more carbon atoms, as exemplified by polyethylene, polypropylene, ethylenebutene copolymers, and the like.
• silver halide layers and any other hydrophilic colloid containing layers present in the elements of this invention can be hardened with any suitable hardener,
• the silver halide layers can also contain additional additives, particularly those known to be beneficial in photographic emulsions, including, for example, lubricating materials, stabilizers, speed increasing materials, plasticizers, and the like.
• the silver halide layers described herein can also contain spectral sensitizing dyes.
• Suitable spectral sensitizers of this type include the cyanines, merocyanines, complex(trinuclear)cyanines, complex(trinuclear)merocyanines, styryls and hemicyanines.
• the silver halide layers can also be developed using incorporated developers such as polyhydroxybenzenes, aminophenols, 3-pyrazolidones, and the like.
• Suitable agents of this type include non-ionic, ionic and amphoteric types, as exemplified by polyoxyalkylene derivatives, amphoteric amino acid dispersing agents, including sulfobetaines, and the like.
• Such surface active agents are described in US. Pat. 2,600,831 issued June 17, 1952; US. Pat, 2,271,622, issued Feb. 3, 1942; US. Pat. 2,271,623, issued Feb. 3, 1942; US. Pat. 2,275,727, issued Mar. 10, 1942; US. Pat. 2,787,- 604, issued Apr. 2, 1957; US. Pat. 2,816,920, issued Dec. 17, 1957; US. Pat. 2,739,891, issued Mar. 27, 1956 and Belgian Pat. 652,862.
• the emulsion can also contain additional additives, particularly those known to be beneficial in photographic emulsions, including for example, stabilizers or antifoggants, particularly the water-soluble inorganic acid salts of cadmium, cobalt, manganese and zinc as disclosed in US. Pat. 2,829,404, the substituted triazaindolizines as disclosed in US. Pats. 2,444,605 and 2,444,- 607, speed increasing materials, absorbing dyes, plasticizers and the like.
• Sensitizers which give particularly good results in the photographic compositions disclosed herein are the alkylene oxide polymers which can be employed alone or in combination with other materials, such as quaternary ammonium salts, as disclosed in US. Pat. 2,886,437 or with mercury compounds and nitrogen containing compounds as disclosed in US. Pat. 2,751,299.
• the process of the invention may be used with multilayer coatings such as emulsion layers designed for color processing, for example, emulsions containing color forming couplers or emulsions to be developed by solutions containing couplers or other color-generating materials.
• multilayer coatings such as emulsion layers designed for color processing, for example, emulsions containing color forming couplers or emulsions to be developed by solutions containing couplers or other color-generating materials.
• the photographic elements prepared according to the instant invention can be used in various kinds of photographic systems. In addition to being useful in X-ray and other non-optically sensitized systems, they can also be used in orthochromatic, panchromatic and infrared sensitive systems.
• EXAMPLE I An aqueous emulsion containing 68 grams of the latex copolymer (butyl acrylate-sodium acryloylpropane sulfonate-Z-acetoacetoxyethyl methacrylate) having a Tg between -20 and 30 C. is added to a coarse-grained sulfur-gold sensitized silver 'bromoiodide photographic, X-ray emulsion (98.5 mole percent bromide and 1.5 mole percent iodide), containing 68 grams of gelatin and one mole of silver halide. The resultant emulsion is coated on both sides of a poly(ethyleneterephthalate) support at 525 mg. of silver/ft. A control emulsion containing 139 grams of gelatin per mole of silver as the only vehicle was coated in a similar manner.
• the latex copolymer butyl acrylate-sodium acryloylpropane sulfonate-Z-ace
• control coating is dried slowly (12 minutes) and another part is dried rapidly (4 /2 minutes).
• sample containing the polymer is dried rapidly 4 /2 minutes).
• the dried coating were exposed of a second to a simulated X-ray screen exposure and processed in a K- dak M4 X-Omat Processor with the following results:
• EXAMPLE II A sulfur-gold sensitized silver bromoiodide emulsion (98.5 percent bromide and 1.5 percent iodide) containing 50 grams of gelatin per mole of silver halide is mixed with an emulsion containing 50 grams of copoly(butyl acrylate-2-sodiumacryloyloxy propane sulfonate-Z-acetoacetoxyethyl methacrylate) having a Tg between 20 C. and 30 C. The resultant emulsion and a control sample are coated and tested as in Example I.
• EXAMPLE III Fifty-five grams of a solution polymer of copoly(ethyl acrylate-acrylic aeid-Z-acetoacetoxyethyl methacrylate) having a Tg between 0 C. and l0 C. is added to a silver bromoiodide emulsion containing 55 grams of gelatin per mole of silverhalide. The resultant emulsion and a control emulsion are tested as described in Example I.
• a liquid photographic silver halide emulsion comprising silver halide and a binder vehicle consisting essentially of about 75 to about 25 percent by weight of gelatin with about 25 to about 75 percent by weight, based on total binder vehicle, of a water-insoluble synthetic polymeric latex binder which is compatible with gelatin and which has a glass transition temperature of less than 20 C.
• said latex binder comprising a copolymer containing units of alkyl acrylate and units of at least a second component selected from acrylic acid, sulfoester acrylates, sulfobetaine units and units of a monomer having an active methylene group, the halide of said silver halide being predominantly bromide and (2) removing substantially all liquid to about 15 percent or less, total carrier from said emulsion in less than 6 minutes.
• said synthetic polymer is a copolymer containing units of alkyl acrylate and units of a monomer having an active methylene group.
• said synthetic polymer is a latex copolymer of butyl acrylatesodium acryloyloxypropane sulfonate 2 acetoacetoxyethyl methacrylate.
• the said latex binder comprises a copolymer of at least three components containing units of alkyl acrylate and units of at least second and third components selected from units of acrylic acid, sulfoester acrylates, sulfobetaine units and units of a monomer having an active methylene group.
• said synthetic polymer is a latex of copoly(ethyl acrylate acrylic acid-2-acetoacetoxyethyl methacrylate).

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• General Physics & Mathematics (AREA)
• Paints Or Removers (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)

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Citations (3)

• 1967
  • 1967-03-02 US US619918A patent/US3533793A/en not_active Expired - Lifetime
• 1968
  • 1968-02-22 FR FR1560667D patent/FR1560667A/fr not_active Expired
  • 1968-02-23 BE BE711248D patent/BE711248A/xx not_active Expired
  • 1968-02-29 GB GB9804/68A patent/GB1208961A/en not_active Expired
  • 1968-03-01 DE DE19681622925 patent/DE1622925A1/de active Pending

Patent Citations (3)

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