US2496903A

US2496903A - Photographic developer containing a negatively substituted aralkylamine and process of development

Info

Publication number: US2496903A
Application number: US786816A
Authority: US
Inventors: William L Wasley
Original assignee: General Aniline and Film Corp
Current assignee: GAF Chemicals Corp
Priority date: 1947-11-18
Filing date: 1947-11-18
Publication date: 1950-02-07
Anticipated expiration: 1967-02-07
Also published as: GB641405A; BE485786A; DE848911C; FR973438A

Description

Patentecl Feb. 7, 1950 UNITED STATES ATENT OFFICE PHOTOGBAPHIC DEVELOPER CONTAINING A NEGATIVELY SUBSTITUTED ARALKYL- AMINE AND PROCESS OF DEVELOPMENT William L. Wasley, Binghamton, N. Y. assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application November 18, 1947, Serial No. 786,816

12 Claims. (Cl. 9588) V 1 This invention relates to photographic deing color images in multi-color photographic velopers and particularly to accelerators for layers containing color-formers fast to diffusion, photographic developers. as disclosed in United States Patents 2,178,612;

It is well-knownthat various amines, such 2,179,228; 2,179,234; 2,179,238-9; 2,179,244; as primary and secondary alkyl and alkylene 2,186,719; 2,186,851-2; 2,186,732-3-4; 2,186,849; amines containing from 3 to 7 carbon atoms, and 2,200,306; 2,280,722; 2,292,575; 2,303,928 and heterocyclic amines such as morpholine and 7,399, with a color developer containing a piperidine as disclosed in United States Patent eg y substituted aralky a 2,304,025, may be added to photographic black vol-oping time is cut from 20-30 minutes to 2- 10 and white and color developing solutions for 10 minutes All f the l y r a Simultaneously the purpose of increasing the rate of developdeveloped, and e dy images e ed are of ment. In other words, these amines accelerate ellent quality- 7 the development so as to cause the developing The developing e w th black and white agent to form the image (silver or color image) developers, for instance, solutions of hydromore rapidly than is possible without the presquinone and monomethylam ne- -p S111- ence of such amines. fate and the like, is also cut to about one-hall Although developing solutions containing such W hout cau fee when such solutions contain amines cut the developing time from about a negatively Substituted a y to minutes to 12 to 15 minutes, such a de- The negatively substituted aralkylamines tocrease is still unsatisfactory where large scale 0 be p y in accordance with present operati-ons are involved, as in commercial proc- Vent/i011 ar represented by e foll win e essing where time is of the essence. eral u a It is also known that there are 'aralkylamines which, when present in developing solutions in (0Hz)nNHa an amount ranging from 8 to 30 cc. per liter, 25 energize weak developers to the eiztent that second exposure is not necessary for reversal x development. and

It has always been assumed by the art, howso ever, that these aralkyl amines, in order to be operative as energizers for developing solutions, must be free from negative groups such as nitro, hydroxy, sulfonic acid, halogen atoms, e. g., Cl, Br, and the like. It has now been found that X certain aralkyl amines in which negative groups wherein R is methyl or ethyl n is a positive such as nitro, and halogen atoms are attached teger of from 1 t 2, and X i negative group to carbon atom in the and ring greatly such as nitro chlorine bromine and the like celerate development rates and energize weak The followihg are examples of Such negativly developers to an extent that no second exposure 40 substituted arauwl amines. is necessary for reversal development. This discovery is wholly surprising and unexpected OHZNHZ in view of the contrary teachings and assumption by those skilled in the art.

It is, therefore, an object of the present invention to provide a black and white and color p-chlorobenzylamine developer having an increased rate of development so that the developing time is substantially GENE decreased to about one-half of the normal time.

Other objects will appear hereinafter.

Theseobjects are accomplished by adding an aralkylamine containing a negative nitro or halogen group attached to a carbon in the aryl mibmmmefizflflmine ring to the usual black and white developer, and to a color-forming developer in which a 5 primary aromatic amine is used as the developing agent. It has been found that in developp-nitrobenzylamine a- [pchlorophenyl]-ethylamine u- [p-chlorophenyl] -propylamine CH CHzNH [m-bromopbenyl -ethy1an1ine These amines possess limited solubility in Water and in alkaline developers. Their solubility in water and in alkaline developers, however, is made appreciable by converting the base into a salt such as, for example, the hydrochloride or carbonate. The hydrochloride salt is readily prepared by the addition of a stoichiometrical quantity of hydrochloric acid, and the carbonate is prepared by bubbling CO2 into an alcohol, ether or benzene solution of the base. The most useful concentrations in black and white and color developers range from about 1 to 7 grams per liter of developer solution.

As illustrative developing solutions containing such aralkylamines, the following are given:

Example I Grams p-Monomethylamine-m-phenol sulfate 0.8 Sodium sulfite (anhydrous) 45 Hydroquinone 1.2 Sodium carbonate (monohydrate) 8 Potassium metabisulfite 4 Potassium bromide 1.5 p-Chlorobenzylamine 4 Water to make liter 1 This tank developer gives, on development at 20 C. of the usual roll film, a soft negative in about 6-10 minutes after fixing and washing. The time required to develop a similar roll in the same developer and at the same temperature, but containing no p-chlorobenzylamine, ranges from 15 to 20 minutes. Increasing the concentration of the p-chlorobenzylamine to '7 grams per liter effects a further decrease in time.

Example II The following developer requires 30 minutes at 20 C. to give a satisfactory degree of color development with color paper:

Grams Sodium hexametaphosphate 1.0 Sodium bisulfite 2.0

N N bis (fi-hydroxyethyl) -p'-phenylenediamine sulfate 6.3 Sodium carbonate 100 Hydroxylamine hydrochloride 1.0 Potassium bromide 1.0 Water to make liter 1 By the addition of 5 grams of a-(p-chlorophenyD-ethylamine to the foregoing developing solution, a color paper of excellent color rendition is developed in 10 minutes. Increasing the concentration of the amine further reduces the time of development.

The color paper (photographic multi-layer element) utilized in the foregoing example, consists of an integral tripack emulsion coated on either the usual paper base, or a clear cellulose acetate or nitrate film base, or in some cases an opaque white film base. Each of the emulsion layers is sensitized to one of the primary colors of light; namely, blue, green and red. The top layer is blue sensitive. A filter layer, yellow in color and blue absorbing, lies under the top layer. Below this filter layer, lies a green sensitive emulsion layer, and below this a red sensitive emulsion layer. Each of the three silver-halide emulsion layers contains dye-forming compounds which unite during the development of a silver image in an aromatic amine developing agent to form a dye with the oxidation product of the developing agent. As silver is also formed during development, it must be removed after color development by treatment in a bleach, followed by a bath of sodium thiosulfate, as is well-known to the art. A yellow dye is formed in the blue sensitive emulsion; a magenta dye is formed in the green sensitive emulsion; and a cyan dye is formed in the red sensitive emulsion. The combination of the dye images from these three printing primaries yields the color picture. Suitable methods for the preparation of multicolor emulsion layers have been described in the literature relating to color photography, and

v are, therefore, not described here.

Example III The following developer requires 19 minutes at 20 C. to give a satisfactory degree of color development with color paper:

Grams Sodium hexametaphosphate 1.0 Sodium bisulfite 2.0

N ethyl N-hydroxyethyl-p-phenylenediamine sulfate 6.7 Sodium carbonate Hydroxylamine hydrochloride 1.0 Potassium bromide 1.0 Water to make liter 1 By the addition of 3.5 grams of p-nitrobenzylamine to the foregoing developing solution, a color paper of excellent color rendition is developed in 10 minutes. Increasing the concentration of the amine to 6 grams reduces the time of development to 6 minutes with the same results.

Example IV ed from the class consisting-of those corresponding to the following formulae:

wherein R is a group selected from the class consisting of methyl and ethyl groups, n is a positive integer of from 1 to 2, and X is a negative group selected from the class consisting of nitro and halogen atoms, and the salts of said amines.

2. An alkaline photographic developer for silver-halide comprising a silver-halide developer and a negatively substituted aralkylamine characterized by the following formula:

3. An alkaline photographic developer for silver-halide comprising a silver-halide developer and a negatively substituted aralkylamine characterized by the following formula:

4. An alkaline photographic developer for silver-halide comprising a silver-halide developer and a negatively substituted aralkylamine characterized by the following formula:

CHZNHZ 5. In the development of a photographic negative the step comprising the development of an exposed silver-halide emulsion in an alkaline developer containing a developing agent for said emulsion and a developing accelerator selected from the class consisting of negatively substituted aralkyl amines corresponding to the following formulae:

wherein R, is a group selected from the class consisting of methyl and ethyl groups, n is a positive integer of from 1 to 2, and X is a negative group selected from the class consisting of nitro and halogen atoms, and the salts of said amines.

6. In the development of a photographic negative the step comprising the development of an exposed silver-halide emulsion in an alkaline .developer containing a developing agent for said emulsion and .a developing accelerator characterized by the formula:

7. In the developmentof a photographic negative the step comprising the development of an exposed silver-halide emulsion in an alkaline developer containing a developing agent for said emulsion and a developing accelerator characterized by the formula:

8. In the development of a photographic negative the step comprising the development of an exposed silver-halide emulsion in an alkaline developer containing a developing agent for said emulsion and a developing accelerator characterized by the formula:

9. A color-forming photographic developer comprising a primary aromatic amino developing agent and a negatively substituted aralkylamine selected from the class consisting of those corresponding to the following formulae:

anon-N112 and | OIL-NH:

10. A color-forming photographic developer comprising a primary aromatic amino developing agent and a negatively substituted aralkylamine characterized by the following formula:

0 HzNH:

11. A color-forming photographic developer comprising a primary aromatic amino developing agent and a negatively substituted aralkylamine characterized by the following formula:

CH3 (BE-NH:

8 12. A color forming photographic developer REFERENCES CITED 'comprising a, primary aromatic amino develop- I ing agent and a negatively substituted aralkylg z Z ES i Rq i of record m the amine characterized by the following formula: p

5 UNITED STATES PATENTS Number Name Date 2,410,644 Fierke et a1. Nov. 5, 1946 mm L. WASLEY.

Claims

1. AN ALKALINE PHOTOGRAPHIC DEVELOPER FOR SILVER-HALIDE COMPRISING A SILVER-HALDIE DEVELOPER AND A NEGATIVELY SUBSTITUATED ARALKYLAMINE SELECTED FROM THE CLASS CONSISTING OF THOSE CORRESPONDING TO THE FOLLOWING FORMULAE: