US3928042A - Preservatives for photographic developers - Google Patents

Preservatives for photographic developers Download PDF

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Publication number
US3928042A
US3928042A US490361A US49036174A US3928042A US 3928042 A US3928042 A US 3928042A US 490361 A US490361 A US 490361A US 49036174 A US49036174 A US 49036174A US 3928042 A US3928042 A US 3928042A
Authority
US
United States
Prior art keywords
solution
plicatic acid
plicatic
plicatate
developer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US490361A
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English (en)
Inventor
Arthur Karchmar
Jr Leo Lawrence Nejelski
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TDK Micronas GmbH
ITT Inc
Original Assignee
Deutsche ITT Industries GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deutsche ITT Industries GmbH filed Critical Deutsche ITT Industries GmbH
Priority to US490361A priority Critical patent/US3928042A/en
Priority to CA231,546A priority patent/CA1069746A/fr
Application granted granted Critical
Publication of US3928042A publication Critical patent/US3928042A/en
Assigned to ITT CORPORATION reassignment ITT CORPORATION CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: INTERNATIONAL TELEPHONE AND TELEGRAPH CORPORATION
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03CPHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C5/00Photographic processes or agents therefor; Regeneration of such processing agents
    • G03C5/26Processes using silver-salt-containing photosensitive materials or agents therefor
    • G03C5/29Development processes or agents therefor
    • G03C5/305Additives other than developers

Definitions

  • ABSTRACT The storage life of silver halide developer solutions is extended by the addition to the solutions of salts, esters and amides of plicatic acid.
  • salts, esters and amides of plicatic acid act as preservatives when added to solutions for developing silver halide photographic material.
  • the plicatic acid compounds produce no loss in film speed when addedto'such solutions and have no significant effect on the fog level of the developed film.
  • Plicatic acid is a polyphenolic compound obtained from aqueous extracts of western red cedar wood. Processes for its separation and recovery are described in US. Pat. No. 3,716,574, assigned to the present assignee.
  • the salts and esters of plicatic acid are disclosed in US. Pat. Nos. 3,754,937 and 3,644,481, both assigned to the present assignee.
  • the amides of plicatic acid are disclosed in copending US. application Ser. No. 316,056, filed 12-18-72, now US. Pat. No. 3,810,941 also assigned to the present assignee.
  • plicatic acid esters and salts which are useful in the invention are sodium and potassium plicatate and lower alkly plicatates such as methyl, ethyl, n-propyl, iso-propyl and Z-butyl plicatate.
  • useful amides are ethyl and n-propyl plicatamide.
  • Plicatic acid itself has been found to be too highly'acidic to be useful it tends to neutralize and thus impair the effectiveness of the normally alkaline developer solution.
  • the amount of plicatic acid derivative used may, at the lower end, be any amount which is effective to extend the life of the developer. As little as 0.01% (0.1 grams/liter) has been found to be effective to extend the storage life of the solutions.
  • the maximum amount of plicatic acid derivative is that which is soluble in the developer solution, normally about 0.5% (5 grams/liter).
  • a preferred amount of the preservative is from 0.02 to 0.3% (.2 to 3 grams/liter). (Percentages of preservative, as used herein, are weight by volume, being 1000 grams/liter).
  • the normally somewhat acidic plicatic acid derivative be neutralized or made slightly alkaline prior to addition to the alkaline developer solution. This may conveniently be done, for example, by adding sodium carbonate or other mild alkali to a water solution of the plicatic acid derivative to raise its pH to 7 or above, preferably about 7.5. Neutralization avoids alteration of the alkalinity of the developer and hence prevents degradation of the quality of the developed film. Developers (such as Eastman Kodak D-76) are commercially available as. premixed powders which the user dissolves in water to obtain the final developer solution. It is possible to obtain at least some of the plicatic acid derivatives in either neutral or slightly alkaline crystalline form which can be incorporated directly into such preparations.
  • Photographic developer solutions with which the preservatives of the invention are useful are well known in the art. They are chemical solutions widely used in developing exposed silver halide photographic materials and are described in detail, for example, in Photo- Lab-lndex, Henry M. Lester, published by Morgan and Morgan, Dobbs Ferry, N.Y., 1973 (published annually with quarterly supplements).
  • a typical composition consists of aqueous solutions of a reducer which is the developing agent, an accelerator (an alkali), a stabilizer to inhibit aerial oxidation and a retardant to limit development of unexposed silver grain.
  • Commonly used developing agents are hydroquinone, p-aminophenol or p-methylaminophenol sulfate.
  • Useful accelerators are alkalis such as borax or sodium carbonate.
  • a commonly used stabilizer is sodium ,sulflte.
  • Potassium bromide is a frequencly used retardant. It should be understood that the foregoing compositions are merely illustrative.
  • Catechol 274 126 calibrated to give equal flow in the lines to the tank Samoqui 403 185 distribution tUbCS. Aeration was carried out at ambient Number of hours of aeration to reduce the maximum negative density to 70% of room temperatures. The color and height of the developers in the tank were checked daily, the latter being maintained at 9.0 inches above the gas distribution The results show that all of the plicatic acid derivatives tubes by the addition of distilled water to insure a conextended the aging life of the developer. It also shows stant hydrostatic pressure. that, at the 0.10% level, the other commercial antioxi- Negative film optical densities were measured with a dants also extended developer life.
  • Catechol will afthe density of the unexposed portion of each film to feet the kinetics of the developer solution because of its obtain their fog densities.
  • Fog, or negative density produced by factors other The following six commercially available antioxithan image exposure, is also an important factor in dants were also investigated for their comparative evaluating developers. High fog levels are undesirable value in extending the life of photographic developer because they reduce negative contrast and increase solutions. The last three of the antioxidants were found printing exposure time.
  • Butylated hydroxy toluene (BHT) solubility in Groups 1 and 2 containing 0.1% additive were aerated water (0.0575 gm./1.) was too low for comparative at a rate of 2.5 liters per minute.
  • the tests of Group 3 tests. were aerated at 3.5 liters per minute in an attempt to S.
  • Butylated hydroxy anisole (BHA) dissolved but reduce the time required to inactivate the solutions.
  • the invention thus offers a relatively simple and economical method of increasing the working life of developer solutions.
  • the invention is particularly significant where batches of films are processed at intervals and stored for prolonged periods between batches. It is accordingly applicable, not only to amateur photographic practice, but also to experimental laboratories, photographic studios and other processors using manual batch development as opposed to continuous machine processing.
  • An aqueous solution for developing photographic material comprising a silver halide developing agent and as a preservative therefor a compound selected from the group consisting of salts, esters and amides of plicatic acid in an amount effective to extend the storage life of said solution, said amount being at least 0.01% on a weight/volume basis.
  • a process for extending the storage life of aqueous solutions for developing photographic materials comprising adding to said solution containing a silver halide developing agent a preservative compound selected from the group consisting of salts, esters and amides of plicatic acid in an amount effective to extend the storage life of said solution, said amount being at least 0.01% on a weight/volume basis.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)
US490361A 1974-07-22 1974-07-22 Preservatives for photographic developers Expired - Lifetime US3928042A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US490361A US3928042A (en) 1974-07-22 1974-07-22 Preservatives for photographic developers
CA231,546A CA1069746A (fr) 1974-07-22 1975-07-15 Derive d'acide plicatique pour la conservation du revelateur agx

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US490361A US3928042A (en) 1974-07-22 1974-07-22 Preservatives for photographic developers

Publications (1)

Publication Number Publication Date
US3928042A true US3928042A (en) 1975-12-23

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Family Applications (1)

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US490361A Expired - Lifetime US3928042A (en) 1974-07-22 1974-07-22 Preservatives for photographic developers

Country Status (2)

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US (1) US3928042A (fr)
CA (1) CA1069746A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4014699A (en) * 1973-05-17 1977-03-29 Ciba-Geigy Ag Preparation for the processing of photographic materials
US5863713A (en) * 1997-04-07 1999-01-26 Aviles; John Jay Process repeatedly regenerates developers

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3515556A (en) * 1967-08-01 1970-06-02 Eastman Kodak Co Photographic developing process utilizing hemlock tannin polymer
US3644481A (en) * 1968-03-06 1972-02-22 Itt Rayonier Inc Plicatic acid esters
US3716574A (en) * 1967-12-01 1973-02-13 Rayonier Inc Pure crystalline plicatic acid tetrahydrate and the methyl ester thereof
US3754937A (en) * 1972-08-13 1973-08-28 Rayonier Inc Plicatic acid esters
US3810941A (en) * 1972-12-18 1974-05-14 Itt Plicatamides

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3515556A (en) * 1967-08-01 1970-06-02 Eastman Kodak Co Photographic developing process utilizing hemlock tannin polymer
US3716574A (en) * 1967-12-01 1973-02-13 Rayonier Inc Pure crystalline plicatic acid tetrahydrate and the methyl ester thereof
US3644481A (en) * 1968-03-06 1972-02-22 Itt Rayonier Inc Plicatic acid esters
US3754937A (en) * 1972-08-13 1973-08-28 Rayonier Inc Plicatic acid esters
US3810941A (en) * 1972-12-18 1974-05-14 Itt Plicatamides

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4014699A (en) * 1973-05-17 1977-03-29 Ciba-Geigy Ag Preparation for the processing of photographic materials
US5863713A (en) * 1997-04-07 1999-01-26 Aviles; John Jay Process repeatedly regenerates developers

Also Published As

Publication number Publication date
CA1069746A (fr) 1980-01-15

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Legal Events

Date Code Title Description
AS Assignment

Owner name: ITT CORPORATION

Free format text: CHANGE OF NAME;ASSIGNOR:INTERNATIONAL TELEPHONE AND TELEGRAPH CORPORATION;REEL/FRAME:004389/0606

Effective date: 19831122