US2482546A - Phenoxyalkylamines as accelerators for photographic developers - Google Patents

Description

Patented Sept. 20, 1949 TORS FOR PHOTGG ERS RAF HIG DEVELOP- Frank J. Kaszuba,'Binghamton, N. 'Y.',, assig'nor'to General Aniline & Film- :Corporation, New York, N. Y., a corporation of Delaware No Drawing. a lication-fin 9,1948, Serial No. 37,965

12 Claims. (01. 95-88) Thistinvention relates to photographic develop'ers'and particularly to phenoxyalkylamines as accelerators for photographic developers.

it is well known that various amines, such as primary and secondary alkyl and alkylene amines containing from 3 to '7. carbon atoms, 7 and heterocycli'c amines. such as morpholine' and piperidine as disclo'sed in United States Patent No'. 2,304,025, maybe added to photographic black and white and color developing solutions for the purpose of increasing the rate of development. In other words, these amines accelerate the development so as. to cause thedeveloping agent to form the image .(silverl er cio'ljr im' e). more rapidly than i-s"po'ssible without the'preserlfce of suchfamines;

Although developing 'solutionsc'ontaining such amines. .cut the. developingtim'e to 12 115 minutes, such period: is..still..unsatisfactory where large scale operations-are involved, as incommercial processing where time is of-the essence.

"It isalso knownuthat. there are aralkylamines which, when present "in. developing solutions in an amount ranging.from..8 to cc. per liter, energize. weak. developers tothe extent that second exposure is not necessary for reversal develbp exit. It has alwaysbeenfassumed by the art, however, that all of these amine-5,111- order to be operative as energizersifor developing solutions inust be free from groups, such as nitro; hydroxy, sulfonic. acid, halogenatoms, e; g., chl'orine, bromine, and the like. Moreover, rn ost amines are somewhat toxic and lead to skin eruptions when development of the film is done with bare hands.

I have foun'dthat' phenoxyalkylamines greatly accelerate development rates and energize weak developers to an extent that no second exposure is necessary for reversal development, even if they contain a nitro group or a halogen in the aryl ring. Such phenoxyalkylamines, moreover, are less toxic than the aralkylamines of the prior art which are substituted or unsubstituted in the arylring by a negative group. g

It is, therefore, an object of the present invention to provide a black and white and color developer having an increased rate of development so that the developing time is substantially decreased to about one-half of the normal time, and which developer is less toxic than those heretofore used.

Other objects will appear hereinafter. H H

The phenoxyalkylamines employed in accordancewith the present invention are represented by the following general formulae:

chlorine, bromine and the n is a positive integer of from 2 to 3, andX 'is hydrogen, a nitro group, or a halogen such as The following are examples of such phenoxy- 'fl Phenoxyethylamine .sstationsamateurish fl-ti-nitroph euoxy) -ethylaniine o emeemase,

qi-cmaraphenbzy prtpylenime The foregoing amines are prepared according to the methods described in Ber. 22, 3256 889), Ber. 24, 189 (1891), and Ber. 70B, 985 (1937).

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 sulfate, hydro-.

chloride, or carbonate. The sulfate and hydrochloride salts are readily prepared by the addition of a stoichiometrical quantity of dilute sulfuric acid and hydrochloric acid, respectively, and the carbonate is prepared by bubbling CO2, into an alcohol, ether, or benzene solution of the base.

In developing color images in multi-color photographic layers containing color formers fast to diffusion with a color developer containing a phenoxyalkylamine, the developing time is cut from 20-30 minutes to 2-10 minutes. All of the layers are simultaneously developed, and the dye images formed are of excellent quality.

The developing time with black and white developers, for instance, solutions of hydroquinone and p-monomethylaminephenol sulfate and the like, is also out to about one-half without causing fog when such solutions contain a phenoxyalkylamine. 7

The most useful concentrations in black and White and color developers range from about 1 to 8 grams per liter of developer solution.

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

Example I p-Monomethylaminophenol sulfate grams 0.08 Sodium sulfite (anhydrous) do 45 Hydroquinone do 1.2 Sodium carbonate (monohydrate) do 8 Potassium metabisulfite do 4 Potassium bromide do 1.5 fi-Phenoxyethylamine do 4 Water to make liter 1 This tank developer gives, on development at 20 C. of the usual roll film, a negative in about 6 to 8 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 B-phenoxyethylamine, ranges from 15 to 20 minutes. Increasing the concentration of the ,8-phenoxyethy1amine to 6 grams per liter eifects 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:

By the addition of grams of ,6-(4-bromophenoxy) -ethylamine to the foregoing developing solution, a color paper of excellent color rendition is developed in about 8 minutes. Increasing the concentration of the amine further reduces the time of development.

The color photographic multi-layer element utilized in the foregoing example, consists of an integral tri-pack 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 multi-color emulsion layers have been described in the literature relating to color photography, and are, therefore, not described here.

Example III The following developer requires 19 minutes at 20 C. to give a satisfactory degree of color de- By the addition of 4 grams of 'y-(4-chlorophenoxy) -propylamine to the foregoing developing solution, a color paper of excellent color rendition is developed in about 8 minutes. Increasing the concentration of the amine to 6 grams reduces the time of development to 6 minutes with the same results.

Example IV The color developer of the preceding example with the addition of 5 grams of [3-phenoxyethy1- amine developed a multi-layer color film sheet, of the reversal type, and containing color formers fast to diffusion, in about 8 minutes at 20 C whereas without the 18-phenoxyethylamine, the,

time required to color develop the said film sheet is over 30 minutes.

The above examples are to be regarded as merely illustrative of the invention and not in any sense restrictive. It will be obvious to those skilled in the art that many modifications, such as substituting equivalent materials and varying the proportions of the materials used are within the spirit and scope of the invention. The scope, therefore, of the invention is to be limited solely by the following claims.

I claim:

1.'An alkaline photographic developer for silver-halide emulsions comprising an aromatic silver-halide developing agent and a phenoxyg i a alkylamine selected from the class-consisting of those corresponding to the following formulae:

' O-(OH2)1|" NH2 and ems-came,

wherein R and R1 represent a group selected from the class consisting of hydrogen and methyl, R being hydrogen when R1 is methyl and R1 being hydrogen when R is methyl, 'n is a positive integer of from 2 to 3, and X is a group selected from the class consisting of hydrogen, nitro and halogen, and the salts of said amines.

2. An alkaline photographic developer for silver-halide emulsions comprising an aromatic silver-halide develop-ing agent and a phenoxyalkylamine characterized by the following formula:

3. An alkaline photographic developer for silver-halide emulsions comprising an aromatic silver-halide developing agent and a phenoxyalkylamine characterized by the following formula:

4. An alkaline photographic developer for silver-halide emulsions comprising an aromatic silver-halide developing agent and a phenoxyalkylamine characterized by the following formula:

5. In the development of a photographic negative, the step comprising the development of an exposed silver-halide emulsion in an alkaline developer containing an aromatic silver-halide developing agent for said emulsion and a developing accelerator selected from the class consisting of phenoxyalkylamines corresponding to thefollowing formulae:

wherein R and R1 represent a group selected from the class consisting of hydrogen and methyl, R being hydrogen when R1 is methyl and R1 being hydrogen when R is methyl, n is a positive integer of from 2 to 3, and X is a group selected from the class consisting of hydrogen, nitro and halogen, 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 an; alkaline developer: containing" 18.1! aromatic siliverehalide developing agent for said" emulsionand a deyelrfi oping accelerator characterized by the formula:

' Oo-omorimm 7 In"ohe dev elopmen tf a photographic negative, the step comprising the development of an exposed silver-halide emulsion in an alkaline developer containing an aromatic silver-halide developingagent 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 an aromatic silver-halide 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 phenoxyalkylamine selected from the class consisting of those corresponding to the following formulae:

CH2. CH2- CHLNH:

and

O-GHa CHaNH:

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

12. A color-forming photographic developer 7 8 cqmprismg a primary aromatiearnino develoging REFERENCES CITED agent and a phenoxyalkylamlne characterlzed by the following formula: v V The following references are of record in the file of this patent:

OOHz.OHz.OH .NHa UNITED STATES PATENTS Number Name Date 2,181,941 Goldacker et a1. Dec. 5, 1939 2,327,813 Nadeau et a1 Aug. 24, 1943 FRANK J. KASZUBA. 10 2,371,740 Dearing et a Mar. 20, 1945