US2563785A

US2563785A - Direct positive photographs from hydrazine-containing developers

Info

Publication number: US2563785A
Application number: US159150A
Authority: US
Inventors: Charles E Ives
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1950-04-29
Filing date: 1950-04-29
Publication date: 1951-08-07
Anticipated expiration: 1968-08-07
Also published as: FR1087759A; GB702162A; BE502879A; DE877548C

Description

Patented Aug. 7, T951 DIRECT POSITIVE PHOTOGRAPHS FROM HYDR-AZINE-CONTAINING DEVELOPERS Charles E. Ives, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New J ersey No Drawing. Application Aprii 29, 1950, Serial No. 159,150

7 Claims.

Thisinvention relates to photography and particularly to a method of making direct positive photographs.

In Fallesen U. S. Patent 2,497,875, a method is described for making direct positive photographs with an internal latent image type emulsion by developing the exposed emulsion in an aerial fogging developer with access of oxygen.

I have now found a method for developing direct positive images in an exposed internal latent image emulsion which does not require formaldehyde and which, therefore, has better keeping properties than developers hitherto used for this purpose. In addition, the developers which I propose to use do not require the addition of oxidizin agents or any special areation technique for production of the positive image.

According to my invention the internal latent image emulsion is exposed and placed directly in a silver halide developing solution containing a hydrazine compound of the general formula in which at least two Rs are hydrogen atoms and when less than four Rs are hydrogen atoms, the remaining Rs are aryl, aralkyl, acyl, or carboxylic acid amide groups. Preferably, the hydrazine compound does not contain more than one aralkyl, acyl, or carboxylic acid amide group, although it may contain either one or two aryl groups.

The photographic emulsion used in the process of my invention is a gelatino-silver halide emulsion such as a silver bromide emulsion, a silver bromoiodide emulsion or a silver chloroiodide emulsion. It need not contain optical sensitizing dyes although certain sensitizing dyes may be added to it for the purpose of optical sensitizing or for promoting reversal. The emulsion should be undigested or if digested, the digestion should be carried out without the use of sulfur sensitizers. as Burtons emulsion, described in Wall, Photographic Emulsions, 1929, pages 52 and. 53. Burtons emulsion is made as follows:

Silver nitrate g 100 Water cc 500 Ammonia-to form clear solution.

B Potassium broinid'e g 80 Potassium iodide g 50 Soft gelatin g 20 Water cc 1000 C Dry gelatine g 250 An emulsion of this type is that known 2 B is heated to 70 C. and A, cold, added to B with constant shaking, digested for 20 minutes .at 50 C., and allowed to cool slowly. C is added after being allowed to swell for 20 minutes in water, drained and melted. The emulsion is then set and washed.

An internal latent image emulsion, that is, one which forms the latent image mostly inside the silver halide grains, as described on pages 296 and 297 of Mees The Theory of the Photographic Process, 19%2, is especially useful for the process of my invention.

Most of the internal latent image emulsions are silver promo-iodide emulsions of high iodide content, preferably containing at least l0%20% of iodide. Burtons emulsion is an emulsion of this type, having a silver iodide content of approximately of the content of silver halide. It is not absolutely essential, however, for the emulsion to contain silver iodide.

An internal latent image emulsion made as described in Davey and Knott U. S. application Serial No. 82,914, filed March 22, 1949, may also be used according to my invention. This emulsion is prepared by first forming in the absence of ammonia and in one or more stages silver salt grains consisting at least partly of a silver salt which is more soluble in water than silver bromide, subsequently convertin the grains to silver bromide or silver bromoiodide and if the silver iodide content of the emulsion is less than 6% calculated on the total silver halide, treating such grains with an iodine compound to bring the silver iodide up to at least 6%, ripening preferably in the absence of ammonia and then either washing out some of the soluble salts or washing out the Whole of the soluble salts, followed by the addition of soluble salts such as soluble chloride or bromide. An example of an emulsion made in this way is as follows:

Solution No. 1:

Inert gelatine grams 2 0 KCl dour- 20] at 40 C. Water lcc 560 Solution No. 2:

KCl gi'ams 100 a Water "cc." 52ml Solution No. 3: I

AgNOs "grams; 195 0 Water cc 520)} Solution No. 4:

KBr "grams; 160 KI do 40] at 45 0. Water cc 500 Run solutions Nos. 2 and 3 simultaneously into solution No. 1 in a vessel, taking seconds to do this. Then ripen for 1 minute at 45 C. Next add solution No. 4, then ripen for 20 minutes at 45 C. Next add 235 grams of inert gelatine (dry). Then ripen at 45 C. for 15 minutes during which time the gelatine dissolves. Set and shred the emulsion and then wash until free from all soluble bromide and then add about 150 cc. of 10% solution of KCl (by weight), and then add water to make 3 /2-1itres.

An internal latent image type of silver halide emulsion may be defined as one which, when a test portion is exposed to a light intensity scale for a fixed time between A and 1 second, and developed for 4 minutes at 20 C. in the ordinary, surface developer (Example I), exhibits a maximum density not greater than /5 the maximum density obtained when the same emulsion is equally exposed and developed for 3 minutes at C. in an internal type developer (Example II). Preferably the maximum density obtained with the surface developer is not greater than lie the maximum density obtained when the same emulsion is developed in the internal type developer. Stated conversely, an internal latent image emulsion, when developed in an internal type developer (Example II) exhibits a maximum density at least 5, and preferably at least 10, times the maximum density obtained when the same emulsion is exposed in the same way and developed in a surface developer (Example I).

My process is carried out by exposing the internal latent image emulsion layer to an object or image and then placin the exposed emulsion layer directly in a silver halide developing solution containing one or more of the hydrazine compounds. Developing agents suitable for use in the process of my invention include the usual phenolic or aminophenol type developing agents, such as N methyl p aminophenol sulfate, p benzohydroquinone, catechol, Z-methyl hydroquinone, 2-chlorohydroquinone, p-aminophenol, and. pyrogallol. The developing solution should have a pH of from 10 to 13, depending upon the degree of activity of the particular hydrazine compound which it contains, although the preferred range with most hydrazine compounds is from pH 11 to pH 12.

The following hydrazine compounds are suitable for use according to my invention:

NHzNHz-2H C1 Hydrazine dihydrochloride Phenylhydrazine hydrochloride p-Bromphenylhydrazine hydrochloride p-Chlorphenylhydrazine hydrochloride 2,5-dichlorophenyl hydrazine p-Tolyl hydrazine hydrochloride p-Toluene sulfonyl hydrazine a-Naphthylhydrazine p-Acetylphenylhydrazine a-Benzyl-a-phenylhydrazine hydrochloride C H11CH-C O NHNHi CH2C ONHNHz n-Arnyl succinyl dihydrazide NaSO3CH-C ONHNH:

CH2-O ON HNHz Sodium sulfosuccinyl dlhydrazide NHC ONHNH; I THC ONHNHz Hydrazine dicarbonic dihydrazide Hydrazobenzene HOOC NHNH2 p-Hydrazinobenzoic acid p-Hydrazinobenzene sulfonic acid (sodium salt) SOaNa Phenylhydrazine-m-sulfonic acid (sodium salt) omsomnomcmQ-zvnnm p- B- Methylsulfonamido) ethyl] phenyl hydrazine B-Phenyl acethydrazido pyrldiniurn chloride N=COH ddition product of phenyl hydrazine and 1-phenyl-3- ,hydroxy-5-pyrazolone of probable structure shown N,N diphenyl hydrazine p-Diphenyl hydrazine cummnnOOnnnmnm p,p-Dihydrazino-dipheny1-dihydrochloride NH O O NHNB:

NH C O NE NH:

4-p-phenylene disemicarbazide An ordinary, surface-type developer, that is, one which develops an image only on the surface of the grains of an internal latent imageemulsion, is the following:

Example I p-Hydroxyphenylglycine g Sodium carbonate (crystals) g 100 Water .to liter 1 Development time, 4 min. at C.

An internal type developer, that is, one which develops an image inside the grains of an internal latent image emulsion, is the following:

Example II Hydroquinone g 15 Monomethyl-p-aminophenol su1fate -g 15 Sodium sulfite (anhydrous) r g 50 Potassium bromide -g 10 Sodiumhydroxide g Sodium thiosulfate (crystals) g 20 Water to liter 1 Development time, 3 min. at 20 C.

My invention will be further described by ref erence to the following specific example:

Example In An emulsion made as described in the Davey and Knott application Serial No. 82,914. was coated on a support, dried and exposed on an intensity scale sensitometer to 3000 Kelvin tungsten illumination and developed for 3 minutes at 70 F. in a solution of the following compositions:

N-methyl-p-aminophenol sulfate g 5 Hydroquinone g 10 Sodium sulfite g 75 Sodium metaborate g Sodium hydroxide g 10 Phenyl hydrazine hydrochloride w g 0.5 Water to liter 1 sulfonyl hydrazine, no reversal was obtained when the 5-methyl benzotriazole was added to the developer. In some cases the reversal was weakened by adding the benzotriazole. In other cases the maximum density was increased by adding 5- methyl benzotriazole to the developer, for example, with phenyl hydrazine or p- [5- (methylsulfonamido) ethyl] phenyl hydrazine.

Although the reversal effect obtained in my process does not require agitation of the developer or the presence of oxidizing agents, I believe that the fogging action obtained is related to aerial oxidation. The active agent, which is derived from the hydrazine compound appears to have a long life in the developing solutions and only brief exposures to atmospheric oxygen appear sufiicient to produce fogging even in the absence of continued aeration. My process, therefore, has distinct advantages for deep tank photographic processing.

It will be understood that the examples and modifications included herein are illustrative only and that my invention is to be taken as limited only by the scope of the appended claims.

I claim:

1. The method of obtaining a direct positive image in a silver halide emulsion layer which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between M and 1 second and development for 3 minutes at 20 C. in the following internal type developer Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate l5 Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20 Water to 1 liter gives a maximum density at least 5 times the maximum density obtained when the equally exposed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I) Grams p-Hydroxyphenylglycine 10 Sodium carbonate Water to 1 liter and developing only the unexposed portion of said emulsion layer in a developer containing a hydrazine compound of the general formula in which at least 2 Rs are hydrogen atoms and when less than 4 Rs are hydrogen atoms, the remaining Rs are selected from the class consisting of aryl, aralkyl, acyl and carboxylic acid amide groups, but not more than one B is any one of said aralkyl, acyl and carboxylic acid amide 7 V utes at. 20 C. in the following internal type developer (II) Grams Hydroquinone 15 Monomethyl p-aminophenol sulfate 15 Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20. Water to 1 liter gives a maximum density at least 5 times the maximum density obtained when the equallyjexposed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I):

Grams pl-Hydroxyphenylglycine Sodium carbonate 100 Water to 1 liter and developing only the unexposed portion of said emulsion layer in a developer containing a hydrazine compound of the general formula Where R. is a mononuclear aryl radical.

3. The method of obtaining a direct positive image in a silver halide emulsion layer, which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion 5 layer a test portion of which upon exposure to a light intensity scale for a fixed time between /1o0 and 1 second and development. for 3 minutes at C. in the following internal type developer (II):

Grams Hydroquinone 15 Monoethyl-p-amoniphenol sulfate 15 Anhydrous sodium sulfite 50 Potassium bromide 10' Sodium hydroxide Sodium thiosulfate 20 Water to 1 liter gives a maximum density at least 5 times the maximum density obtained when the equally exposed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I):

Grams p-Hydroxyphenylglycine 10 Sodium carbonate 100 Water to 1 liter and developing only the unexposed portion of said emulsion layer in a developer containing phenylhydrazine hydrochloride.

4. The method of obtaining a direct positive image in a silver halide emulsion layer, which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between /100 and 1 second and development for 3 minutes at 20 C. in the following internal type developer (II):

posed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I):

Grams p-Hydroxyphenylglycine 10 Sodium carbonate 100 Water to 1 liter Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate 15 Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20 Water to 1 liter gives a maximum density at least 5 times the maximum density obtained when the equally exposed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I):

,. Grams p-Hydroxyphenylglycine 10 Sodium carbonate 100 Water to 1 liter and developing only the unexposed portion of said emulsion layer in a developer containing p- [5 (methylsulfonamido) ethyllphenyl hydrazine.

6. The method of obtaining a direct positive image in a silver halide emulsion layer. which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between /100 and 1 second and development for 3 minutes at 20 C. in the following internal type developer (II):

Grams Hydroquinone 15 I Monomethyl-p-aminophenol sulfate 15 Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20 Grams Hydroquinone 1'5! Monomethyl-p-aminophenol sulfate 15 V Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20 Water to 1 liter gives a maximum density at least 5 times the 'maximum density obtained when the equally ex- Water to 1 liter gives a maximum density at least 5 times the maximum density obtained when the equally'exposed silver halide emulsion is developed for 4 minutesat 20 C. in the following surface developer (I) v Grams p-I-Iydroxyphenylglycine 10 Sodium carbonate Water to 1 liter and developing only the unexposed portion of said emulsion layer in a developer containing pphenylene disemicarbazide. I

'7. The method of obtaining a direct positive image in a silver halide emulsion layer, which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between /100 and 1 second and develoment for 3 minutes at 20 C. in the following internal type developer (II) Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate l5 Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20 Water to 1 liter gives a maximum density at least 5 times the maximum density obtained when the equally exl0 posed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I):

Grams p-Hydroxyphenylglycine 10 Sodium carbonate 100 Water to 1 liter and developing only the unexposed portion of said emulsion layer in a developer containing sodium sulfosuccinyl dihydrazide.

CHARLES E. IVES.

No references cited.

Certificate of Correction Patent No. 2,563,785 August 7 1951 CHARLES E. IVES It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 7, line 38, for Monoethyl-p-amonipheno1 sulfate read MonomethyLp-aminophenol sulfate;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of October, A. D. 1951.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Claims

1. THE METHOD OF OBTAINING A DIRECT POSITIVE IMAGE IN A SILVER HALIDE EMULSION LAYER WHICH COMPRISES EXPOSING TO LIGHT RAYS TO WHICH THE EMULSION IS SENSITIVE, A SILVER HALIDE EMULSION LAYER A TEST PORTION OF WHICH UPON EXPOSURE TO A LIGHT INTENSITY SCALE FOR A FIXED TIME BETWEEN 1/100 AND 1 SECOND AND DEVELOPMENT FOR 3 MINUTES AT 20* C. IN THE FOLLOWING INTERNAL TYPE DEVELOPER (II)