Title:
Photographic developer
United States Patent 2289367


Abstract:
This invention relates to photographic development processes and in particular to the development of latent images formed in silver halide photographic emulsions. It is an object of this invention to provide a new series of compounds capable of acting as photographic developers. It is a further...



Inventors:
David, Kendall John
Application Number:
US39568041A
Publication Date:
07/14/1942
Filing Date:
05/28/1941
Assignee:
LLFORD LTD
Primary Class:
Other Classes:
430/466, 430/481, 430/483, 548/370.7
International Classes:
G03C5/30
View Patent Images:



Description:

This invention relates to photographic development processes and in particular to the development of latent images formed in silver halide photographic emulsions.

It is an object of this invention to provide a new series of compounds capable of acting as photographic developers. It is a further object of this invention to provide new photographic deeloping compositions. A still further object of the invention is to provide a substitute for Metol (1-methyl-amino-4-hydroxy benzene) in photographic developers. Other objects will appear hereinafter, According to this invention the development of latent images formed in photographic materials bearing silver halide emulsions is effected by m~Pain2, ,r __ ious methods. Thus compounds in which Ri in the above general formula is an hydrogen atom may be prepared by condensing hydrazine hydrate with an a-P-oleflne carboxylic acid of the general formula: R2 Rr-CH==-COO00 Compounds in which Ri is a hydrocarbon group may be prepared by condensing the corresponding hydrocarbon-substituted hydrazine with a p-halogen-substituted fatty acid of the general formula: R- -R2 R--CHX-H--COOH .--. s i erials wit a solution containing a 3-pyrazolidone of the general formula: H \- c=o 20 / they form the sole active developing agents or Sthey may be employed in developing composiH , NH 25 agent according to this invention is 1-phenyl-3N pyrazolidone. This compound has developing 1, qualities which somewhat resemble those of where R, hy and R3 a re the same or different and are hydrogen atoms or hydrocarbon groups, orinstance, alkyl groups, e. k. methyl, ethyl, propyl, isopropyl or higher alkyl groups, aryl groups, e. g. phenyl and naphthyl groups or aralkyl groups, e. g. benzyl groups. Such hydrocarbon substituent groups may themselves be substituted; for example, arly groups may be substituted with hydroxy, alkoxy, oxyalkyl, amino, substituted amino, nitro, sulphonic or carboxylic groups or halogen atoms.

Specific 3yrrazdlidones which may be em- 40 ployed according to this invention are 3-pyrazolidone itself, 5-phenyl-3-pyrazolidone, 1-phenyl-3-pyrazolidoine, 1-phenyl-5-methl-3 en-done and 1z - p- chlorphenyl - 3 - Pmyrazy0 -. lidone and 1-p-chlorphenyl -3-pyrazolidone.

Compounds which the group R e Compounds in which the group and the groupsve formula is an aryl group, and the e groups R2 and R3 are hydrogen .atoms are especially valuable developing agents according to this invention.

oThe devlcompounds of er. his invention may also be The "pyazoldons my b prpare byvar 50 X being a halogen atom, e. g. chlorine, bromine or iodine.

The developing agents of this invention may be employed in developing compositions in which tions which also contain other active developing agents. A particularly valuable developing phate). It as..a very low inertia period i. e. 30 development sets in very rapidly, and it yields developed images of soft contrast. It may be satisfactorily used as a substitute for metol in all types of developing compositions in which metol has hitherto been employed. However, 35 it presents the very distinct advantage over metol that, used as a substitute for metol in developing solutions containing other developers in addition to the metol, e. g. hydroquinone or pyrogallic acid, it may be employed in concentrations much smaller than those in which metol is normally employed, whilst retaining similar developing properties.

developing properties.

Thus, for example, replacement of the metol in a metol-hydroquinone developer by about %, 45 n a metol-hydroquinone developer by about 4 to % of its weight of l-phenyl-3-pyrazolidone according to the particular developer composition yields a developer of similar development s er o imilar deelo characteristics to the initial metol-hydroquiThe compounds of this invention may also be 2 2,289, employed as substitutes for part only of the metol in metol-type developers, and in general the compounds may be employed as additions to all types of developer compositions where they serve as agents to decrease the inertia period of such developing compositions.

The following examples illustrate the invention: EXAMPLE I 10 In this example 1-phenyl-3-pyrazolidone is employed as the sole developing agent.

Developer 25 50 0.5 500 For use, one part of this developer is diluted with l" three parts of water. It is a very soft-working ,developer giving results of a similar character to those obtained from a similar developer containing an equal weight of metol as the sole developing agent, but of softer contrast. 25 EXAMPLE II In this example 1-phenyl-3-pyrazolidone is used as a substitute for the metol in a metolhydroquinone developer.

Developer 1-phenyl-3-pyrazolidone ------grams-- 0. Sodium sulphite (crystalline)--~-do--- 75 Hydroquinone------------------do --. 4 Sodium carbonate (crystalline) .-do.--- 50 Potassium bromide-------------do---- 1 Water to make up to----------ccs-- 500 For use, one part of this developer is diluted with 40 two parts of water. It yields results which are very closely similar to those obtained from a similar developer containing 1 gram of metol instead of the 0.15 gram of 1-phenyl-3-pyrazolidone.

Thus it will be noted that by substituting for 45 the metol in this standard type of metol-hydroquinone developer, 'r of its weight of 1-phenyl3-pyrazolidone, a developer'of very similar characteristics is obtained.

EXAMPLE III In this example, 1-phenyl-3-pyrazolidone is used as a substitute for the metol in a metolpyrogallic acid type of developer.

Developer Solution A: 1-phenyl-3-pyrazolidone .--grams-Potassium metabisulphite----- do-- . Pyrogallic acid------------ do---Water to make up to--. .------ccs0.2 6 6 500 Solution B: Sodium carbonate (crystalline) -grams-- 100 Water to make up to -----------ccs- 500 0 For use, equal parts of solutions A and B are mixed together. The developer has properties very closely similar to those obtained from a corresponding developer containing 2 grams of metol instead of the 1-phenyl-3-pyrazolidone. In other words, by substituting for the metol in this standard type of developer, only A of its weight of l-phenyl-3-pyrazolidone, a developer of very similar characteristics is obtained. 7 EXAMPLE IV This illustrates the addition of 1-phenyl-3pyrazolidone to a metol hydroquinone developer.

Developer 1-phenyl-3-pyrazolidone ------ grams-- 1.0 Metol -------------------------do.-- 1.0 Sodium sulphite (crystalline)------do-- 75 Hydroquinone ----------------do--- 4 Sodium carbonate (crystalline) --do.--- 50 Potassium-bromide--------------do-- 1 Water to make up to------------- . cos 500 For use, one part of this developer is diluted with 2 parts of water.

This developer is much more rapid in action than a developer not containing the 1-phenyl-3pyrazolidone but otherwise of the same composition. The increase in the speed of development due to the presence of the 1-phenyl-3pyrazolidone in the above developer compositions is shown by the following figures which were obtained on development of a fast panchromatic emulsion.

Gamma values Development time at 65┬░ F. incDv r Developer nlu not including 1-phenyl-3- -phnyl-3pyrazoli- pyrazolldone Pdone 2 minutes ...---------------------- 113 0.64 4 minutes ..--------- ---------- 1.42 1.06 Thus it will be seen that the developer containing l-phenyl-3-pyrazolidone gives an image of slightly higher contrast in two minutes' development than is obtained in four minutes without the l-phenyl-3-pyrazolidone.

The foregoing examples are intended primarily to shew the variability of application of the developers and they all specify the compound 1phenyl-3-pyrazolidone. It is to be understood however, that any other 3-pyrazolidone included within the scope of this invention may be similarly employed. Thus, equal weight of 1-p-tolyl3-pyrazolidone, 1-p-chlorphenyl-3-pyrazolidone, and 1-phenyl-5-methyl-3-pyrazolidone substituted for the 1-phenyl-3-pyrazolidone of Example II above give developers of very similar characteristics, the developed images obtained in the case i of developers containing 1-p-chlorphenyl-3pyrazolidone and 1-phenyl-5-methyl-3-pyrazolidone being of somewhat softer contrast.

What I claim is: 1. A photographic developing composition con0 taining a 3-pyrazolidone of the general formula: H C -C=O C NH 0 , N where Ri, R2 and R3 are selected from the class consisting of hydrogen atoms and hydrocarbon groups.

5 2. A photographic developing composition containing hydroquinone and a 3-pyrazolidone of the general formula: H C--C=O I NH S10 RE where Ri, R2 and R3 are selected from the class consisting of hydrogen atoms and hydrocarbon groups.

3. A photographic developing composition containing pyrogallic acid and a 3-pyrazolidone of the general formula: \ SC - -C=0 RH where Ri, R2 and R3 are selected from the class consisting of hydrogen atoms and hydrocarbon groups.

4. A photographic deieloping composition containing 1-methylamino-4-hydroxy benzene, hydroquinone and a 3-pyrazolidone of the general formula: 7. A photographic developing composition contaning l-phenyl-3-pyrazolidone and pyrogallic acid.

8. A photographic developing composition containing l-phenyl-3-pyrazolidone, 1-methylamino4-hydroxy benzene and hydroquinone.

9. An alkaline photographic developing composition containing an alkali metal sulflte, an alkali metal carbonate and a 3-pyrazolidone of the general formula: H, C--c=o II NH R( N k, where Rk, R2 and R3 are selected from the class consisting of hydrogen atoms and hydrocarbon groups.

10. An alkaline photographic developing composition containing an alkali metal sulflte, an al25 kali metal carbonate, potassium bromide, and a 3-pyrazolidone of the general formula: Ri R NH Bk, R I H consisting of hydrogen ┬░atoms and hydrocarbon 40 groups, / \N/ 11. A R3 Ncontaining an alkali metal sulflte, an alkali metal a, carbonate, and 1-phenyl-3-pyrazolidone. where R, R nd R A where Ri, R2 and R3 are selected from the class consisting of hydrogen atoms and hydrocarbon 45 groups.

5. A photographic developing composition containing 4-phenyl-3a-prazolidone.

6. A Photographic developing composition contaninge. -phey--y e and hydroquioe.

where Ri, R2 and R3 are selected from the class photographic developing composition photographic developing composition containing an alkali metal sulfite, an alkali metal carbonate, and -phenyl-3-pyrazolidone and yrogalli acid. -pheny-3-pyraolidone and 13. A photographic developing composition containing an alkali metal sulfite, an alkali metal carbonate, and 1-phenyl-3-pyrazolidone, 1-methylamino-4-hydroxy benzene and hydroquinone.

JOHN DAVID KENDAIL.

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