US3003876A - Photographic process - Google Patents

Description

United States Patent 3,003,876 PHOTOGRAPHIC PROCESS Elkan R. Blout, Belmont, Saul G. Cohen, Lexington, and

Myron S. Simon, Newton Centre, Mass., assignors to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware No Drawing. Filed Aug. 27, 1957, Ser. No. 680,620

4 Claims. (Cl. 96-66) p This invention relates to chemistry and more particularly to novel chemical compounds and novel photographic processes utilizing said compounds as developing agents.

One object of this invention is to provide novel chemical compounds and suitable syntheses for their prepara tion.

Another object of this invention is to provide novel chemical compounds useful as photographic developing agents and intermediates, and methods of developing exposed photosensitive elements using said compounds.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps andlthe relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description. I

The novel compounds of this invention may be represented by the formula:

wherein each R when taken alone may be hydrogen, an alkyl and preferably a lower alkyl containing no more than 5 carbon atoms or an aryl group; the R s when taken together may be an ethylene or propylene group and as such complete a 5 or 6 carbon cycloaliphatic ring; and each Y is an unsubstituted, alkyl-substituted, or halogen-substituted, ortho or para dihydroxyphenyl group; and the acid addition salts thereof. As examples of suitable acid addition salts, mention may be made of the hydrohalides, e.g., hydrochloride or hydrobromide, and of organic acid salts, such as the oxalates.

In a preferred embodiment, Y is a p-dihydroxyphenyl radical and such compounds may be represented by the formula:

wherein R is the same as above.

The preferred compound of this invention is 1,5-bis-(2', -dihydroxyphenyl) -3-pentylamine of the structure:

The novel compounds of this invention may be prepared by condensing a suitable dialkoxybenzaldehydewith a ketone of the structure R1CH2CCH2-R1 I; wherein R has thesame meaning as above, hydrogenating the resulting unsaturated product, condensing the ketone with hydroxylamine to produce the oxime, converting the oxime to an amine by hydrogenation, and removing the alkoxy groups by hydrolysis. In an alternate method, the ketone condensation product may be converted directly to the amine by reductively aminating the keto group with ammonia and hydrogen.

The ketones used in preparing the novel compounds of' this invention should contain methyl or methylene radicals on both sides of the keto group and adjacent to the keto group, in order that the aldehyde condensation may proceed. As examples of ketones useful in preparing the novel compounds of this invention, mention may be made of acetone, methyl-ethyl ketone, diethyl ketone, phenyl acetone, cyclopentanone and cyclohexanone.

As examples of suitable dialkoxybenzaldehydes, mention may be made of 2,5-dimethoxybenzaldehyde and 3,4- dimethoxybenzaldehyde and their alkyl and halogen substituted derivatives.

The following example illustrates the preparation of l,S-bis-(2',5-dihydroxyphenyl)-3-pentylamine and is given for purposes of illustration only.

Example 1 Acetone (6.8 g.) and 2,5-dimethoxybenzaldehyde (39 g.) are added to a vigorously stirred solution of sodium hydroxide (23.5 g.) in a mixture of water (235 cc.) and ethanol (190 cc.). The mixture is stirred at room temperature for about an hour after which a yellow solidified oil'is filtered oif. Extraction with ether yields 1,5-bis- (2,5-dimethoxyphenyl)-penta-1,4-dien-3-one as yellow needles melting at 108 to 108.5 C. This product, dis-- solved in ethyl acetate, is hydrogenated over Raney nickel, at room temperature and a pressure of 30 p.s.i., to give 1,5-bis-(2',5'-dimethoxyphenyl)-3-pentanone as a white crystalline solid melting at C.

The oxime of the above ketone is prepared by refluxing the ketone with hydroxylamine in a 50:50 mixture, by volume, of pyridine and ethanol. After refluxing this mixture for two hours, it is evaporated to an oil, which is thoroughly washed with water. The product which crystallizes from this oil is recrystallized from ether to give a White crystalline product melting at to 87 C. Analysis of the oxime gives a nitrogen value of 3.7% as compared with the calculated 3.75%.

The 1,5-bis-(2',5'-dimethoxyphenyl)-pentanone-3-oxime (40 g.) is hydrogenated in ethanol over Raney nickel at 120 C. and a hydrogen pressure of 1200-1300 psi. for one to one-and-one-half hours. The hydrogenation product is filtered, the ethanol evaporated off and the residue taken up in ether. Precipitation with hydrochloric acid gives a 90% yield of the 1,5-bis-(2,5'-dimethoxyphenol)- 3-pentylamine hydrochloride as a white solid melting at 101 to 103 C.

The dimethoxy amine hydrochloride is refluxed under nitrogen for five hours in concentrated hydrobromic acid, after which the reflux mixture is evaporated to dryness at C. in vacuo. This product is washed several Patented Oct. 10, 1961 invention are useful as photographic developing agents. As an example of a suitable developing compositionutilizing one of the novel compounds of this invention, mention may be made of the following composition:

Water cc 100 Potassium bromide gram 0.2 Sodium hydroxide grams 3.0 1,S-bis-(2,5'-dihydroxyphenyl)-3-pentylamine gram 1.0

It will be understood that it is within the scope of this invention to vary the above composition to suit particular needs. The percentage of materials may be varied and additional materials useful in photographic processes may be added. If the composition is to be spread on a silver halide emulsion, a film-forming thickening agent such, for example, as sodium carboxymethyl cellulose, may be added.

The novel compounds of this invention are useful as developing agents in difiusion transfer processes, both dye and silver transfer, and are especially useful in such photographic processes wherein it is desired to eliminate or minimize the need for washing or stabilizing operations in liquid baths subsequent to the formation of the silver print. Examples of such processes are disclosed in US. Patent No. 2,647,056 to Edwin H. Land. The utility of the developers of this invention is by no means limited. to difiusion transfer reversal processes for they may be satisfactorily employed in conventional multistage multibath photographic processes in black-and-white or color photography. Where the herein disclosed compounds are employed in diffusion transfer processes of the type disclosed in the aforementioned patent, the novel developer composition may have incorporated therein as a further ingredient a silver halide solvent such as sodium thiosulfate. Thus, by adding sodium thiosulfate to the composition illustrated above and using an image-receiving element in conjunction with the photosensitive element, a silver transfer image may be obtained.

The novel compounds of this invention are again useful as intermediates. As an example of such use, mention may be made of the preparation of the dye developers claimed and disclosed in the copending application of Elkan R. Blout and Myron S. Simon, Serial No. 680,619,,

filed concurrently herewith, wherein the compounds of this invention are used in the syntheses of said dye developers.

The novel compounds of thisinvention are further useful as antioxidants in petroleum products, etc.

Since certain changes may be made in the above product and process without departing from the scope of the invention herein involved, it is intended that, all matter contained in the above description shall be, interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A process for developing a photosensitive silver halide emulsion which comprises treating an exposedsilver halide emulsion with an aqueous alkaline solution of acompound represented by the formula:

References Cited in the file of this patent UNITED STATES PATENTS 2,301,381 Dickey et a1. Nov. 10, 1942 2,541,889 Runyan Feb. 13, 1951 2,681,934 Hodge June 22, 1954 2,688,625 Bell et a1. Sept. 7, 1954 2,704,713 Bent et a1. Mar. 22, 1955 2,705,245 Norton Mar. 29, 1955 2,757,091 Oretzky July 31, 1956

Claims (1)

1. A PROCESS FOR DEVELOPING A PHOTOSENSITIVE SILVER HALIDE EMULSION WHICH COMPRISES TREATING AN EXPOSED SILVER HALIDE EMULSION WITH AN AQUEOUS ALKALINE SOLUTION OF A COMPOUND REPRESENTED BY THE FORMULA: