US2901351A

US2901351A - Direct positive photographic material

Info

Publication number: US2901351A
Application number: US551458A
Authority: US
Inventors: Paul Desire Van Pee; Roosens Laurent Pierre
Original assignee: Gevaert Photo Producten NV
Current assignee: Gevaert Photo Producten NV
Priority date: 1954-12-10
Filing date: 1955-12-06
Publication date: 1959-08-25
Anticipated expiration: 1976-08-25
Also published as: FR1136718A; GB796873A; DE1019171B; BE543288A

Description

United States Patent 1 manor POSITIVE PHOTOGRAPHIC lVlATE Paul Dsir Van Pee, Edegem-Antwerp, and Laurent Pierre Roosens, Antwerp, Belgium, assignors to Gavaert Photo-Producten N.V., Mortsel (Antwerp), Belgium, a Belgian company No Drawing. Application December 6, 1955 Serial No. 551,458

Claims priority, application Great Britain December 10, 1954 13 Claims. (Cl. 96-67) g This invention relates to light-sensitive photographic material and particularly to direct positive photographic material.

It is known that, if a photographic silver halide emulsion, which has been exposed to blue light, is subsequently exposed to long-wave radiation before it is developed, the eifect of the original exposure is partly destroyed.

is known under the name' of Herschel-effect and may be used for obtaining a reversed image.

.3 lt is'also known that desensitizing dyes y be added to the emulsion in order to increase the Herschel-effect.

Thus it is known to produce a direct positive emulsion by incorporating in a silver chloride emulsion, which is substantially free from silver bromide or silver iodide, a proportion of compounds having a nitro group attached to a benzene nucleus, such compounds being selected from benzthiazole, quinoline, indolenine, benztriazole and rhodanine compounds and their alkyl quaternary salts, and fogging the emulsion by light or chemical means.

' It is further known that direct positive emulsions may be produced by using a compound according to the genm1 formula "wherein A='a quaternary heterocyclic cinnoline or quin- 1 We have found that direct positive emulsions of high quality may be produced by the general technique described hereinbefore, by using a compound according to one of the tautomeric formulae wherein A=a member selected from the group consisting of a single bond and NH, l

B=a member selected from the ,group consisting of aryl substituted with at least one:nitrogroup, arylene symmetrically substituted by at least one nitro;group', and arylene-SO -arylene substituted symmetrically by at least two nitro groups, the arylene and arylene-SO arylene groups constituting the centre of a symmetrical compound containing two dihydropyrimidine nuclei of one of the above tautomericformulae,"

R =a member selected from the group consisting of hydrogen, hydroxyl, alkyl, aralky'l and aryl,

R =a member selected from the group consisting of hydrogen, alkyl, aralkyl and aryl, V

R =a member selected from the group consisting of hydrogen, alkyl, aralkyl and aryl.

The compounds may be incorporated in silver chloride, silver chloro-iodide or silver chloro-bromide emulsions. The optimum amount is between 25 mg. and 7.5 g. per equivalent of g. silver nitrate.

'. The compounds according to the present invention may also be addedv to alayer which is adjacent to the emulsion. In general, the same, amounts per square metre are used. The emulsionis prefogged by light or chemical means, for example by formaldehyde or.stannous chloride. 7

The following examples are intended to illustrate the present invention without limiting, however, the scope thereof:

E mp 1 200 ml. of a 0.5%'solution methyl alcohol of the compound according to the formula are added to 1 kg. of a silver chloride emulsion containing the equivalent of 30 g. silver nitrate. Then this emulsion is coated on, a paper support and exposed to white light suflicient to'giving a density of at least 1.4 when developed in the following developer:

Metol 1.5 Sodium sulphitelcryst.) 50 Hydroquinone 6 Sodium carbonate (cryst) 100 Potassium bromide -i 1 Water to 1000 ml.

low precipitate is formedi ter cooling, the precipitate is sucked 01f. The product melts at l96-197 C.

Example 2 r no; O

are added.. The emulsion is then coated on a film support. This chemically fogged emulsion is exposed to an image through a Gevalonfilter L 500.

The product of the formulaslast above given is prepared. as follows: 47.42 g. 2-4 dinitrophenylhydrazine are 'dissolved in 600 ml. dioxane, 39 g. 2-methyl-2-thiocyano-4-pentanone are added and the whole is refluxed for '3 hours. After-cooling, the solution is poured in water, the precipitate issucked off and washed with water-and cold ethyl. alcoliol; The precipitate is further washed with 500" ml. hydrochloric acid (2 N) whilst stirring, and, finally with water. The product melts, after recrystallization in acetic acid, at ;2-15 -21 7 C.

Example 3 A gelatin upper layer 1.5% gelatin) whereto previously 100 ml. per litre of a 0.5% solution in diacetone aleohohofthe compound. according to the formula are added, is coated on a silver chloro-iodide emulsion 1% iodide) containing the equivalent of 20 g. silver nitrate per kg. The obtained photographic material is further treated as in Example 1.

'OT tQHr-GOOH V is obtained, which melts at 156-157" c. 3.5 g. of this product are heatedjn 160 ml. hydrochloric acid (2 N) 1 r 4 for 3 hours at the boiling water bath. It does not dissolve but forms small white flocks. After cooling, sucking off and recrystallizing in acetic acid, it melts at 248- 250 c.

Example! 100 ml. of a 0.5 solution in diacetone alcohol of the compound according to the formula are added to 1 kg. silver chloride emulsion containing the equivalent of 20 g. silver nitrate. Next, the emulsion is coated on a paper support and further treated as in Example 1.

The product according to the formula last above given is prepared as follows: to a solution of 3.6 g. p-nitrophenyl-isothiocyanate in 20 ml. benzene, a solution of 1.68 g. beta-amino-butyric acid nitrile in 10 ml. benzene is added. After 30 minutes heating on the boiling water bath, the formed oil solidifies. After cooling, sucking off and recrystallizing in ethyl alcohol, a product according to the formula is obtained which melts at 13 8-139 C. 3.2 g. of product are refluxed for minutes in 30 strong hydrochloric acid. First the whole dissolves and after some time boiling a precipitate is formed. After-cooling, sucking off and recrystallizing in acetic acid, the desired product is obtained under the form offsmall white needles melting at 237--239 C.

V 7 Example 5 .50 ml. of a 0.5% solution in dioxane of the pound according to the formula are added to 1 kg. silver chloride emulsion containing the equivalent of 25 g. silver nitrate. Next, the emulsion is coated on a paper support. The photographic material obtained is further treated as in Example 1.

The product according to the formula last above given is prepared as follows: 1.2 g. picryl hydrazine are dissolved in 60 ml. hydrochloric acid (5 N). Next, 0.78 g. 2-methyl-2-thiocyano-pentanone-(4) are added. The whole is boiled for 1 hour. After cooling, and standing overnight, the obtained product is sucked off, washed with water and recrystallized in acetic acid.

Example 6 4 kg. of a silver chloro-bromide emulsion (10% bromide) containing the equivalent of 20 g. silver nitrate per kg. are heated to 40 C. and-brought at a pH of 8. Next, 8 ml. of an aqueous solution of formaldehyde (40%) are added and the emulsion is kept for 10 minutes at the same temperature. The pH is brought at 6 and 100 ml. of a 0.5% solution in diactone alcohol of the product according to the formula :are added. Then, the emulsion is coated on a film support. This chemically fogged emulsionis exposed to an a image through a Gevalor filter L 500.

The product according to the formula last above given can be prepared as follows: 5.2. g. of the product according to the formula HsN-HNOSOQNH-NH,

NO: N02

are heated for 6 hours with 4,76 g. 2-methyl-2-thiocyanoya .il

were added, is coated on a silver chloro-iodide emulsion (0.1% iodide) containing the equivalent of g. silver nitrate per leg. The photographic material obtained is further treated as in Example 1.

The product of the formula last above given is prepared as follows: 4.56 g. I-S-dinitro-4-6-hydrazino benzene are heated in 150 ml. water for 4 hours on the boiling water bath with 6.28 g. 2-methyl-2-thiocyano-4- pentanone. After, cooling and sucking off, the product obtained is washed with water, hydrochloric acid (2 N), water, ethyl alcohol and ether respectively. After recrystallization in acetic acid, the obtained product melts at 223-224 C.

i We claim:

l. A direct positive silver halide photographic material comprising a silver halide emulsion layer and a gelatin layer adjacent thereto, the gelatin layer containing the product of the formula .6 2. A direct positive photographic material comprising CH (5 NO i NO: (I) 3 a MHGSOGNH a...

Cm L. l l

a silver, halide emulsion containing thegproduct of the 15 formula 3. A direct positive silver halide photographic material comprising a silver halide emulsion layer and a gelatin layer adjacent thereto, the gelatin layer containing the product of the formula 4. A direct positive photographic material comprising a silver halide emulsion containing the product of the 5. A direct, positive silver halide photographic material comprising a silver halide emulsion layer and a gelatin layer adjacent thereto, the gelatin layer containing the product of the-formula 6. A direct positive photographic material comprising a silver halide emulsion containing the product of the formula t it 11.75 7. A positive silver halide photographic mate- .7 rial-comprising .a silverrhalide emulsion layer and a gelatin layer adjacent thereto, the gelatin layer containing the product of the formula v 8, A direct positive photographic material comprisihg a--silver halide emulsion containing the-producbof the formula 1 '9. A direct positive silver halide photographic material comprising a silver halide "emulsion layer and a gelatin layer adjacent thereto, the gelatin layer-containing the product of the formula 10. A direct positive silver halide photographic material comprising an unsensitive gelatin layer adjacent to the silver halide emulsion, said layer containing the product of the formula 11. A direct positive silver halide photographic material comprising arsilver halide emulsion layer and a gelatin layer adjacent thereto, at least one of said layers containing a compound selected from the group consisting of compounds corresponding to one of the tautomeric formulae:

and symmetrical compoundscorresponding to one of the tautomeric formula'ez'l and 1'1 lit in which four formulae A represents a member selected from the group consisting of a single bond and -e-NH-, B represents an aryl radical substituted with at least one nitro group, D represents a member selected from the group consisting of an arylene radical substituted with at least one nitro group, and an arylene-SO -aryle'ne radical, each arylene group of which is substituted with at least one nitro group, R and R each represents a member selected from the group consisting of a hydroxyl radical and an alkyl radical, and R represents a member selected from the group consisting-of ahydrogen atom,--an alkyl radical, and an aryl radical.

12. A direct positive silver halide photographic emulsion characterized by the presence in the emulsion of a compound selected from the group consisting of compounds corresponding to one of the tautomeric formulae:

and symmetrical compounds corresponding to one of the tautomeric formulae:

1 in which four formulae A represents a member: selected from the group consisting of a single bond and''NH-, B represents an aryl radical substituted with at lea stone 'nitro group, D represents a 'memberselcctedfrom the group consisting of an arylene radical s'ubstituted'with at least one nitro group, and an arylene-*SOy'arylene radical, each arylene group of which is substituted with-at least one nitro group, R and R each represents a member selected from the group consisting of a hydroxyl radical and an alkyl radical, and R represents a member selected from the group consisting of a hydrogen atom, an alkyl radical, and an aryl radical.

13. A direct positive silver halide photographic material characterized by the presence in a layer adjacent to the silver halide emulsion of a compound selected from the group consisting of compounds corresponding to one of the tautomeric formulae:

in which four formulae A represents a member selected from the group consisting of a single bond and NH-, B represents an aryl radical substituted with at least one nitro group, D represents a member selected from the group consisting of an arylene radical substituted with at least one nitro group, and an arylene-sO -arylene radical, each arylene group of which is substituted. with at least one nitro group, R and R each represents a member selected from the group consisting of a hydroxyl radical and an alkyl radical, and R represents a member selected from the group consisting of a hydrogen atom, an alkyl radical, and an aryl radical.

References Cited in the file of this patent UNITED STATES PATENTS 2,139,870 Wilmanns et al Dec. 13, 1938 2,173,628 Kendall Sept. 19, 1939 2,231,127 Kendall Feb. 11, 1941 FOREIGN PATENTS 601,824 Great Britain May 13, 1948 707,704 Great Britain Apr. 21, 1954

Claims

11. A DIRECT POSITIVE SILVER HALIDE PHOTOGRAPHIC MATERIAL COMPRISING A SILVER HALIDE EMULSION LAYER AND A GELATIN LAYER ADJACENT THERETO, AT LEAST ONE OF SAID LAYERS CONTAINING A COMPOUND SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS CORRESPONDING TO ONE OF THE TAUTOMERIC FORMULAE: