DE2020814C2 - Direct positive photographic recording material - Google Patents

Description

^ffl N (= CH-CH) _n = CR ¹

(CH ₂ ) *.

CH = N-NH-R ²
contains, in which mean:
R ¹

Χ ^θ

20th

25th

a hydrogen atom or a short chain

Alkyl, alkylthio, aryl or aralkyl radical
R ^{2 is} an optionally substituted phenyl, tolyl, quinolyl or benzthiazolyl radical or jo

a radical of the formula - CS - NH ₂ ,
Z the necessary to complete a 5- or 6-membered hetero ring atoms with nitrogen, oxygen, sulfur or

Selenium atoms as heteroatoms,
Χ ^{θ is} an acid anion that occurs in the betaine structure as a result of

acidic substitution at R ^{2 is} not applicable,
η 0 or 1 and
m 2 to 6.

2-methyl-3- (3-thiosemicarbazonopropyl) benz-

thiazolium bromide,
2-methyl-3- (3-phenylhydrazonopropyl) benz-

thiazolium iodide,
2-methyl-3- (p-totylhydrazonopropyl) benz-

thiazolium iodide,
2-methyl-2- (p-sulfophenylhydrazonopropyl) -

benzthiazolium bromide,
2-methyl-3- (benzthiazol-2-ylhydrazonopropyl) -

benzthiazolium iodide,
3- [3- (4-carboxyphenylhydrazono) propyl] -

2-ethylbenzthiazolium bromide or
2-benzyl-3- [3- (4-sulfophenylhydrazono) -

propyl] benzthiazolium chloride.

55 The invention relates to a photographic direktpositivts recording material comprising a layer support, at least one coated thereon, the latent image predominantly in the interior of the silver halide-forming silver halide emulsion layer, and optionally the intermediate and / or outer layers containing a hydrazone in at least one of the layers

Recording materials of this type in which hydrazides and hydrazones are used as nucleating agents are known, for example, from US-PS 32 27 552. A typical representative of one in US-PS 32 27 552 described nucleating agent is, for example, l-formyl-2-phenylhydrazide. It has, however has shown that these known nucleating agents are not yet particularly effective.

The object of the invention is to provide a direct positive photographic recording material of the type described Indicate type that contains a particularly effective nucleating agent consisting of a hydrazone and has particularly advantageous sensitometric properties

This object is achieved in that the recording material is a compound as a hydrazone the general formula

35 ®N (= CH-CH) _n = CR ¹
(CH ₂ ) _m
CH = N-NH-R ²

contains, in which mean:

40

2. Recording material according to claim 1, R ^1, characterized in that it contains a dye-forming coupler R ^{2 adjacent to the emulsion layer.}

3. Recording material according to claim 1 and 2, characterized in that the hydrazone in the Z Silver halide emulsion layer at a concentration of 75 to 250 mg per mole of silver halide is present.

4. Recording material according to claim 1 to 3, 50 Χ ^θ, characterized in that it contains one of the following compounds as hydrazone:

η m is a hydrogen atom or a short-chain alkyl, alkylthio, aryl or aralkyl radical,

an optionally substituted phenyl, tolyl, quinolyl or benzthiazolyl radical or a radical of the formula -CS-NH ₂ ,

the atoms required to complete a 5- or 6-membered hetero ring with nitrogen, Oxygen, sulfur or selenium atoms as heteroatoms,

an acid anion that is omitted in the betaine structure due to acid substitution at R ^2,

Oor 1 and

In the formula given, the hetero ring completed by Z thus contains, in addition to that in the indicated manner substituted quaternary nitrogen atom 4 to 5 further atoms, of which 3 to 4 Atoms are carbon atoms and the remaining atoms are carbon, nitrogen, oxygen, sulfur or Are selenium atoms.

In the formula given, Z is thus z. B. for the atoms required to complete of an indole, imidazole, oxazole, thiuzole, selenazole or quinoline ring or a ring of the imidazole series, e.g. B. a benzimidazole ring, for example one 5-chlorobenzimidazole ring, or a naphthimidazole ring, or a ring of the thiazole series, e.g. B. one

Thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole or 4- {2-thienyl) thiazole ring, as well as rings of the Benzthiazole pure, for example a benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-chlorobenzthiazole, 7-chlorobenzothiazole, 4-methylbenzthiazole, 5-methylbenzthiazole, 6-methylbenzthiazoi, 5-bromobenzothiazole -, 4-Phenylbenzthiazole, 5-phenylbenzthiazole, 4-methoxybenzthiazole, 5-methoxybenzthiazo! -, 6-methoxy- ι ο benzthiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzthiazoi, 5-ethoxybenzthiazoi, 5-ethoxybenzthiazoi -, Tetrahydrobenzthiazo! -, 5,6-Dimethoxybenzthiazole, 5-hydroxybenzthiazole or 6-hydroxybenzthiazole ring, also a ring of the naphthothiazole series, e.g. B. an α-naphthothiazoI-, 8-methoxy - «- naphthothiazole, 7-methoxy-a-naphthothiazole or naphtho [2, ld] thiazole ring, also a ring of the thionaphtheno-7 ', 6', 4,5- thiazole series, e.g. B. a 4'-Methoxythionaphtheno-7 ', 6', 4,5-thiazole ring, also a ring of the oxazole series, z. B. a 4-MethyJoxazoJ-, 5-methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole or 5-phenyloxazole, also a ring of the benzoxazole series, z. B. a benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole, 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 5-methoxybenzoxazole, 5-ethoxybenzoxazole, 5-chlorobenzoxazole, 6-methoxybenzoxazole, 5-hydroxybenzoxazole or 6-hydroxybenzoxazole rings, also a ring of the κ, naphthoxazole series, for example a «-naphthoxazole ring, also a ring of the selenazole series, e.g. B. a 4-methylselenazole or 4-phenylselenazole ring, also a ring of the benzoselenazole series, e.g. B. a benzoselenazole 5-chlorobenzoselenazole, 5-methoxy r, benzoselenazole, 5-hydroxybenzoselenazole or tetrahydrobenzoselenazole ring, also a ring of the naphthoselenazole series, z. B. a «-Naphthoselenazolringes or a ring of the quinoline series, z. B. a quinoline or lepidine ring.

In the formula given, X ^e can stand for a wide variety of customary anions, e.g. B. for a halide anion, for example a bromide, chloride or iodide ion, also for a sulfate anion, e.g. B. a sulfate, hydrosulfate or short-chain alkyl sulfate ion, for example a methyl sulfate or ethyl sulfate ion, also for an aromatic sulfate anion, e.g. B. a p-toluenesulfonate and benzenesulfonate ion, also for an acid ion derived from a carboxylic acid, e.g. B. for an acetate, trifluoroacetate or propionate ion, as well as z. B. for a perchlorate, cyanate, thiocyanate, sulfamate or benzoate ion.

Typical alkyl and alkylthio ^{radicals that R 1} can represent are branched or straight-chain radicals having 1 to 4 carbon atoms, e.g. B. methyl, ethyl, propyl, isopropyl, η-butyl or tert-butyl radicals as well as z. B. methylthio, ethylthio and tert-butylthio radicals.

The aralkyl radicals for which R ^{1 can} stand are alkyl radicals with preferably 1 to 6 carbon atoms, which are preferably substituted by a phenyl or naphthyl radical t> o, for example benzyl, phenylethyl, 2-phenylpropyl, naphthylethyl and phenylbutyl radicals.

Typical ones useful for making a photographic material according to the invention Hydrazones are e.g. E.g .: t, -

2-methyl-3- [3- (2-benzthiazolylhydrazono) propyljjenzthiazolium iodide, 3- [3- (p-carboxyphenylhydrazono) propyl] -

2-methylbenzoxazoIiumchlorid, 3- [3- (p-carboxyphenylhydrazono) propyl] -

2-methylbenzthiazolium bromide, 2-methyl-3- [3- (p-toluene sulfonylhydrazono) -

propyl] naphtho [2, l -djthiazolium iodide, 3- [3- (p-chlorophenylhydrazono) propyl] -

2-methylnaphtho [2, l-d] thiazolium bromide, 3- [3- (p-Carboxyphenylhyc! Razono) propyl] -

2-ethylnaphtho [2,1 -d] thiazolium bromide, 2-methyl-3 - [(3-p-nitrophenylhydrazono) pro-

pyl] naphtho [2, l -djthiazolium iodide, l- [3- (p-carboxyphenylhydrazono) propyl] -

4-methylquinolium iodide, 3- [3- (2,4-dinitrophenylhydrazono) butyl] -

benzthiazolium bromide,
2-methyl-3- [3- (N-phenylcarbamoyLhydrazono) -

propyl] naphtho [2,1-djthiazolium iodide, 3- [3- (2,4-dimethylsulfonylphenylhydrazono) propyl] -2-methylnaphtho [2,1 -d] -

thiazolium bromide,
3- [3- (p-carboxyphenylhydrazono) propyl] -

2-benzylbenzoselenazolium-p-toluenesulfonate, Benzyl-3 - [(3-phenylhydrazono) propyl] benz-

thiazolium acetate,
3 - [(3-p-Carboxyphenylhydrazono) propyl] -

2-methylbenzthiazolium bromide, 3 - [(3-p-carboxyphenylhydrazono) propyl] -

5-chloro-2-methylbenzthiazolium bromide, 2-methyl-3- [3- (phenylhydrazono) propyl] benz-

thiazolium benzene sulfonate, 2-ethyl [3-p-sulfophenylhydrazono) propyl] benz-

thiazolium iodide,
2-methyl-3- [3- (p-sulfophenylhydrazono) propyl] -

benzthiazolium iodide,
2-methyl-3- [3-thiosemicarbazono) propyl] -

benzthiazolium bromide,
2-methyl-3- [3- (thiosemicarbazono) propyl] -

benzthiazolium hydrogen sulfate, 2-methyl-3- [3- (phenylhydrazono) propyl] benztl.iazolium bromide,

2-methyl-3- [3- (phenylhydrazono) propyl] benzthiazolium thiocyanate,
2-methyl-3- [3- (p-tolylhydrazono) propyl] benz-

thiazolium bromide,
2-methyl-3- [3- (p-sulfophenylhydrazono) propyl] -

benzthiazolium bromide,
2-methyl-3- [3- (p-toluenesulfonylhydrazono) pen-

tyl] benzthiazolium bromide, 2-methyl-3 - [(3-thiosemicarbazono) propyl] benz-

thiazolium perchlorate,
2-methyl-3 - [(3-phenylhydrazono) propyl] benz-

thiazolium benzene sulfonate, 2-methyl-3- [3- (p-tolylhydrazono) propyl] benz-

thiazolium acetate,
2-methyl-3- [3- (p-sulfophenylhydrazono) propyl] -

benzthiazolium propionate, 2-methyl-3- [3- (2-benzthiazolylhydrazono) -

propyljbenzthiazolium bromide, 5,6-dichloro-1-ethyl-2-methyl-3- [3- (p-sulfophenylhydrazono) propy!] Benzimidazolium

bromide,
5,6-dichloro-3- [3- (2-benzothiazolylhydrazono) propyl] -1 -ethyl-2-methy lbenzimidazolium-

bromide,
5,6-dichloro-2-methyl-3- [3- (3-quinolylhydra-

zono) propyl] -l-ethylbenzimidazolium bromide, 5-chloro-2-methyl-3- [3- (p-tolylhydraizono) -

propyl] benzoselenazolium bromide, 2-methyl-3- [3- (p-toluenesulfonylhydrazono) -

propyl] benzthiazolium bromide,
2-methyl-3- [3- (p-tolylhydrazone} propyl] -

benzthiazolium bromide,
3- [3- (2,4-Dinitrophenylhydrazono) propyl] benzthiazolium bromide.

hydrazono) propyl] benzimidazo! iumbromid, 56-dichloro-1-ethyl-2-methyl-3- [3- (p-nitro- ίο

phenylhydrazono) propyl] benzimidazolium

bromide,
3- [3- (p-carboxyphenylhydrazono) propyl] -

5-methoxy-2-methylbenzthiazolium bromide, 3- [3- (p-carboxyphenylhydrazono) propyl] - 15

5,6-dimethoxy-2-methylbenzthiazolium bromide, 3- [3- (p-carboxyphenylhydrazono) propyl] -

2-methylnaphtho [23-d] thiazolium bromide, l- (p-carboxyphenylhydrazono) f-opyl-2,3,3-tri-

methyl-3H-indo] iumbromide, 20

2-methyl-l- [3- (p-carboxyphenylhydrazono) -

propyl] -1 H-benz [e] indolium bromide, 3- [3- (p-carboxyphenylhydrazono) propyl] -

5,6-dimethoxy-2-methylbenzothiazolium bromide, 3- [3- (p-carboxyphenylhydrazono) propyl] - 2 ",

2-methylnaphtho [2,3-d] thiazolium bromide, 3- [3- (2-benzothiazolylhydrazono) butyl] -

2-methylbenzthiazolium iodide,
3- [3- (p-Carboxyphenylhydrazono) pentyl] -

2-methylbenzoxazolium chloride, jo

3- [3- (p-Carboxyphenylhydrazono) hexyl] -

2-methylbenzthiazolium bromide, 2-methyl-3- [3- (p-toluenesulfonylhydrazono) -

butyl] naphtho [2, t-d] thiazolium iodide, 3- [3- (p-chlorophenylhydrazono) heptyl] - 55

2-methylnaphtho [2, l-d] thiazolium bromide, 3- [3- (p-carboxyphenylhydrazono) butyl] -

2-ethylnaphtho [2, l-d] thiazolium bromide, 2-methyl-3- [3- (p-nitrophenylhydrazono) -

propyl] naphtho [2, l-d] thiazolium iodide, 40

2-methyl-3- [3- (N-phenylcarbamoylhydrazono) -

pentyl] naphtho [2, l-d] thiazolium iodide, 3- [3- [2,4-bis (methylsulfonyl) phenyl-

hydrazono] hexyl] -2-methylnaphtho [2, l-d] -

thiazolium bromide, 45

3- [3- (p-carboxyphenylhydrazono) heptyl] -

2-benzylbenzoselenazolium-p-toluenesulfonate, 2-methyl-3 - [(3-phenylhydrazono) butyl] benz-

thiazolium acetate,
3- [3- (p-Carboxyphenylhydrazono) pentyl] - 50

2-methylbenzthiazolium bromide, 3- [3- (p-Carboxyphenylhydräzono) butyl] -

S-chloro ^ -methylbenzthiazolium bromide, 3- [3- (phenylhydrazono) hexyl] benzthiazolium

benzenesulfonate, 55

2-ethyl- [3- (p-sulfophenylhydrazono) butyl] -

benzthiazolium iodide,
2-methyl-3- [3-p-5ulfophenylhydrazono) pentyl] -

benzthiazolium iodide,
2-methyl-3- [3- (thiosemicarbazono) heptyl] - «1

benzthiazolium bromide,
2-methyl-3- [3- (thiosemicarbazono) hexyl] -

benzthiazolium hydrosulfate,
2-methyl-3- [3- (phenylhydrazono) butyl] benz-

thiazolium iodide, h5

2-methyl-3- [3- (phenylhydrazono) pentyl] benz-

thiazolium thiocyanate,
2-methyl-3- [3- (p-tolylhydrazono) heptyl] benzthiazolium iodide,
2-methyl-3- [3- (p-sulfophenylhydrazono) butyl] -

benzthiazolium chloride,
2-methyl-3- [3- (thiosemicarbazono) pentyl] -

benzthiazolium perchlorate, 2-methyl-3- [3- (phenylhydrazono) butyl] benz-

thiazolium benzene sulfonate,
2-methyl-3- [3- (p-tolyIhydrazono) pentyl>

benzthiazolium acetate,
2-methyl-3- [3- (p-sulfophenylhydrazono) butyl] -benzthiazolium propionate,

butyl] benzthiazoliumcyanal,

phenylhydrazono) pentyl] benzimidazolium bromide,

5,6-dichloro-3- [3- (2-benzothiazoylhydrazono) butyl] -1-ethyl-2-methylbenzimidazolium bromide.

zono) propyl] -1 -ethylbenzimidazolium bromide, 5-chloro-2-methyl-3- [3- (p-tolylhydrazono) -

hexyljbenzselenazolium bromide, 2-methyl-3- [3- (p-toluenesulfonylhydrazono) -

butyl] benzthiazolium bromide, 2-methyl-3- [3- (p-tolylhydrazono) pentyl] -

benzthiazolium bromide,
3 [3- (2,4-Dinitrophenylhydrazono) hexyl] -benzthiazolium bromide,

hydrazono) butyl] benzimidazolium bromide, hhtii

yti

phenylhydrazono) pentyl] benzimidazolium bromide,
3- [3- (p-Carboxyphenylhydrazono) butyl] -

5-methoxy-2-methylbenzthiazoliumbΓOInid, 3-f3- (p-carboxyphenylhydrazono) pentyl] -

5,6-dimethoxy-2-methylbenzthiazolium bromide, 3- [3- (p-carboxyphenylhydrazono) hexyI] -

2-methylnaphtho [2,3-d] thiazolium bromide and 1 - [3- (p-Carboxyphenylhydrazono) propyl] -2-methylquinolinium iodide.

The hydrazones used according to the invention can be prepared in a two-stage reaction, wherein the hydrogen salt of a cycloammonium base is reacted with a one in the first stage activated double bond-containing compound, which preferably corresponds to the following structural formula:

CH ₂ = CH- (CH ₂ ) _m _, - R3,

where m = 1 to 5 and R ^{3 is} a formyl, acetyl or propionyl radical, whereupon in a second process step the intermediate product obtained is reacted with hydrazine to give the desired hydrazone.

The reaction is expediently carried out in an inert organic solvent of moderate polarity which dissolves both reactants but is not a solvent for the reaction product formed, which consists of the quaternary salt. Organic solvents with moderate polarity, e.g. B. acetonitrile and dimethylacetamide proved. The use of reaction catalysts is generally not necessary for the reaction. The reaction is advantageously carried out at reaction temperatures of 20 to 3O ⁰ C, but higher or lower temperatures may be employed as long as the reaction components

remain in solution and not heated to temperatures above their decomposition temperature will. The reaction products formed fall out of the reaction solution and can after Isolation in the usual known manner> be cleaned, z. B. by washing with solvents or one or more recrystallization.

Typical hydrazines suitable for carrying out the specified process are, for. B. phenylhydrazine, p-tolylhydrazine, p-sulfophenylhydrazine, thiosemicarb- mi azide, benzihiazol-2-ylhydrazine, p-carboxyphenylhydrazine, p-Tolylsulfohydrazine, p-Chlorophenylhydrazine, p-Nitrophenylhydrazine, N-phenylcarbamoylhydrazine,

2,4-di (methylsulfo) phenylhydrazine, p-carboxyphenylhydrazine and p-suifophenyl hydrazine. ι,

The hydrazones used in the photographic recording materials according to the invention are advantageously photographic silver halide emulsion layers, particularly incorporated into gelatin silver halide emulsion layers. : n

The photographic recording materials according to the invention contain in the silver halide emulsion layers in addition to the hydrazones described, other customary known chemical additives, e.g. B. Spectral sensitization color _ ■■> substances, coating aids, brightening agents, hardening agents and developing agents.

A wide variety of known customary hydrophilic, water-permeable substances can be used to produce the emulsions Binders, for example gelatin, colloidal albumin, polyvinyl compounds, cellulose derivatives and Acrylamide polymers, alone or in combination with one another, can be used. The ones in the Emulsion layers of the photographic recording materials according to the invention present u Binders can optionally also be polymerized vinyl compounds in the form of dispersions contain. Typical suitable vinyl polymers of this type, as they are, for. B. from US-PS 31 42 568, 31 93 386, 30 62 672 and 32 20 844 are known, for. Am water-insoluble polymers and latex mixed polymers made from alkyl acrylates and methacrylates, acrylic acid, Sulfoalkyl acrylates or methacrylates.

Typical for use in the silver halide emulsion layers of the photographic recording materials which can be used according to the invention spectral sensitizing dyes. the z. B. from US-PS 25 26 632 and 25 03 776 are known, for. B. Cyanines, merocyanines, complex trinuclear cyanines, complex trinuclear merocyanines, styryls and hemi- in

In the case of the photographic emulsions which are expediently used for the production of photographic recording materials according to the invention, are gelatin silver halide emulsions, z. B. silver bromide, silver bromide iodide or silver chlorobromide emulsions. These emulsions can be spectrally unsensitized, but they can also contain sensitizing dyes. In advantageous Way usable such sensitizing dyes are z. B. in US-PS 24 97 876, in particular in Column 2, line 15 and column 4, line 20, described. the the latent image predominantly inside the silver halide grain-forming emulsions tend to be not digested or, if they are digested, digestion takes place without the use of chemicals Surface sensitizers. An emulsion of the specified type, known as so-called "Burton's", is z. B. in the book by Wall "Photographic Emulsions", 1927, pages 52 and 53, described. A Another advantageous type of internal image emulsions is e.g. B. from US-PS 25 92 250 known.

The production of such an internal image emulsion, in which the latent image is predominantly in the interior of the Silver halide grains are formed, e.g. B. be done in such a way that initially in one or more Process stages Silver salt grains at least partially made up of silver salts with greater water solubility than that of silver bromide are formed, then at least a portion of those obtained Silver salt grains converted into silver bromide or silver bromide iodide and then, preferably in Absence of ammonia, a process of regeneration is carried out, whereupon the soluble salts either partially or completely washed out and finally soluble salts, e.g. B. soluble chloride, bromide or iodide, can be added in order to produce a ready-to-use silver chloride bromide, silver bromide iodide or silver chloride bromide iodide emulsion. Suitable silver chlorobromide emulsions in which the latent image is predominantly inside the silver halide grains can also be prepared in such a way that an aqueous gelatin solution while stirring simultaneously with an aqueous solution of silver nitrate and a potassium chloride and potassium bromide containing aqueous solution is added, as z. B. from Example 4 of US-PS 29 96 382 known is.

An "emulsion which forms the latent image predominantly in the interior of the silver halide grains" can be defined as an emulsion which is produced on exposure of up to 1 second to light of graduated intensity and subsequent development at 20 ^° C. for 4 minutes in a conventionally known "surface developer as defined below provides an image with a maximum density no more than 1 / sec of the maximum density obtained when the same emulsion sample is subjected to the same exposure conditions for 3 minutes at 20 ° C in a so-called "inner grain" developer is developed according to the definition given below.

“Surface developer” is the term used to describe developers who work in a “the latent image predominantly in the Inside the silver halide grain-forming emulsion «Images only on the surface of the silver halide grains to develop. A typical developer of the type indicated includes e.g. B. the followu; Composition on:

10g
lwfg
1 liter

Sodium carbonate (Krista. E)
topped up with water

"Inner grain developers" are developers who in an "emulsion which forms the latent image predominantly in the interior of the silver halide grains" Develop images inside the silver halide grains. A typical developer of the specified type has z. B. the following composition:

Hydroquinone 15 g
Monomethyl p-aminophenoisulphate 15 g

Sodium sulfite (anhydrous) 50 g

Potassium bromide 10 g

Sodium hydroxide 25 g

Sodium thiosulfate (crystals) 20 g

filled with water to 1 liter

The maximum density obtained with the aid of the specified surface developer is preferably no more than 1/10 of the maximum density obtained with the help of the specified "inner grain" developer will. To put it the other way round, “provides the latent image predominantly in the interior of the silver halide grains forming emulsion «when developing in an» internal developer «images with a maximum Density that is at least 5 times, preferably at least 10 times, greater than the maximum density that is obtained when the same emulsion sample is exposed in exactly the same way and then in one "Surface" developer is developed.

The hydrazones described are silver halide emulsions, z. B. those of the US-PS 25 66 180 and 5 92 250 type known in such Quantities incorporated that a well-dosed veil in the form of tiny surface development centers, 'Which favor the generation of direct positive images during development is generated. As a nucleating agent acting hydrazones are obviously firmer from the silver halide grain surface adsorbed as common known fogging agents, e.g. B. the hydrazine compounds known from US-PS 25 58 982, because to achieve an equally advantageous effect of those which can be used according to the invention Smaller quantities of fogging agents are sufficient. This means a significant advantage over the State of the art, since when using comparatively small amounts of fogging agents with comparatively high effectiveness in an advantageous manner correspondingly lower amounts of fogging agent in the Developer solutions are dispensed without the advantageous sensitometric properties to be achieved be affected.

The photographic recording materials according to the invention contain them as fogging agents active hydrazones expediently in concentrations of 75 to 1500 mg, preferably from 90 to 1200 mg, per mole of silver halide of the silver halide emulsion layers. Depending on the type of emulsion after which chemical activity of the fogging agent used, as well as depending on the development conditions used, However, the hydrazones which can be used according to the invention and act as fogging agents are also can be used advantageously outside the specified concentration range.

For the production of the direct positive photographic recording materials according to the invention known supports commonly used for photographic purposes can be used.

The photographic applications of the present invention can be either those having color reversal emulsion layers or black-and-white silver halide emulsion layers . For the production of color reversal photographic materials e.g. B. cyan, magenta and yellow dye-forming couplers adjacent to the silver halide emulsion layers, which are capable of recording light, the color of which corresponds practically to the complementary color of the dyes formed during color development with the aid of the corresponding color couplers, are used, as described e.g. B. from US-PS 32 27 550 and 32 27 552 is known. Furthermore, spectral Sensibüisienmgsfarbstoffe can be used to sensitize the silver halide present in a conventional manner.

So z. B. a multi-layer, for the color photo

graphic specific recording material in the red-recording emulsion layer z. B. 5- (p-Ainyl phenoxybenzoisulfonamino)! - naphthol, in the green recording Emulsion layer e.g. B. 2-Cyanoaceiyi-5- (p-sec.-aniylbenzoylamino) coumaron, as well as in the blue recording emulsion layer z. B. N-amyl-p-benzoylacetaminobenzenesulfonate contain. Further suitable couplers are known to the person skilled in the art. If appropriate, the color couplers can also be added to the developer solutions be incorporated, as z. B. from US-PS 22 52 718 and 25 07 154 is known, but one such a procedure requires multiple exposure and color development stages.

After imagewise exposure the direct positives containing the indicated nucleating agents become photographic recording materials in a conventionally known surface developing solution based on the existing silver halide only has a comparatively low dissolving effect, immersed under Creation of a positive photographic image. Surface developer of the specified type included Advantageously, additives that increase the maximum density of the images produced and the minimum Decrease density of the same, e.g. B. from US-PS 24 97 917 known benzotriazoles.

To produce color images, developer solutions are generally used which contain a p-phenylenediamine color developer compound, z. B. a 4-amino-N-dialkylaniline in the book by Mees "The Theory of the Photographic Process", 3rd edition (1966), pages 294 to 295 of the type described. With the help of a color developer, depending on the structure of the used photographic recording material one or more color images can be produced. When using more polychromatic. Color films are in the rain! Blue-green images in the red-sensitive, purple images in generated the green-sensitive and yellow images in the blue-sensitive layers. That after the development Any silver that is still present is first converted into a soluble silver salt and then into a more common one removed from the photographic recording material in a known manner, e.g. B. by treatment with: a fixative such as sodium thiosulfate.

The following examples are intended to explain the invention in more detail.

example 1

To produce a photographic recording material serving as a comparative sample, a gelatin-silver bromide iodide emulsion, the production of which was carried out by the process known from US Pat. No. 25 92 250, was applied to a cellulose acetate support ° C developed in a developer solution of the following composition:

p-methylaminophenol 3 g

Sodium sulfite (anhydrous) 45 g Hydroquinone 12 g

Sodium carbonate, monohydrate 80 g

Potassium bromide 2 g

made up to 2 liters with water

The positive image obtained by the development was then stabilized in such a manner that it approximately

Il

Was fixed for 3 minutes at 20 ⁰ C in a fixer of the following composition:

Sodium thiosulfate 240 g Sodium sulfite (anhydrous) 15g Acetic acid (28%) 48 ml Boric acid crystals 7.5 g Potassium alum 15g topped up with water 1 liter

A photographic recording material hereinafter referred to as "Sample 2" was also used produced, exposed, developed and fixed in the manner indicated, with the exception that the emulsion used the quaternary ammonium salt 2-methyl-3 - [(3-phenylhydrazono) propy!] benzthiazo iümbromid, which acts as a fogging agent was incorporated at a concentration of 200 mg per mol of silver halide. With the help of the obtained photographic Recording material produced a favorable direct positive image with the values in the table below listed sensitometric properties obtained.

Relative
sensitivity

D _mü

gamma

Comparative sample

Test item 2

100 0.10
3720 1.44

0.04
0.15

0.05

The results show that of the direct positive emulsion added hydrazone is a beneficial nucleating agent.

Example 2

Three direct positive photographic records, hereinafter referred to as A, B and C, were made tion materials produced by light-sensitive loading on polyethylene-coated paper backing Layering compounds of the following composition were applied in the following concentrations:

Concentration mg / m ^: support area

Test item A

Ge'ätine-SübercbJoridbromidjodid- 323, obtained emulsion of the in de r US-PS 25 92 250 on silver

described type

Gelatin 2150

Dye-forming coupler: 323

2- {a- {4 '-tert-amylphenoxy) -n-butyrylamino] -5-methyl-1-phenol
Formyl-4-phenylhydrazine 209

Test item B

As for sample A, but 0.29

_t place of formyl-4-phenylhydrazine
2-methyl-3- [3- (phenylhydrazono) -propyfj-benzthiazolium bromide
used

concentration
nig / nr carrying bag

Test item C

Like Prütling Λ, but was 0.29

Place of lOrmyM-phetiylhydruzine

2-methyl-3 - [(p-lolylhydrazono) -

propyl benzothiuzolium bromide

used

The obtained samples A, B and C were dried, whereupon they passed through a sensitometer a step wedge with neutral density were exposed. The exposed specimens were then 2 minutes long at a temperature of 20 ° C in a developer solution of the following composition developed:

distilled water 1 liter Benzyl alcohol 12 ml Sodium sulfite 1.5 g Potassium bromide 1.0 g Potassium carbonate 55 g 5-nitrobenzimidazole 0.005 g 4-Amino-3-methyl-N-ethyl-0 ■ (methanesulfonamide) ethylaniline sesquisulfathydrst 7g

pH adjusted to 11.3 with sodium hydroxide

To remove the developed silver and the remaining silver salts, the developed test specimens were finally ^{treated for about 3 minutes at a temperature of 20 °} C. with a combined bleaching and fixing solution of the following composition, known as a “blix” solution:

Potassium ferricyanide 35 g

Sodium acetate 20 g

1,8-dihydroxy-3,6-dithiaoctane 25 g

Glacial acetic acid 3 ml

made up to 1 liter with water

pH adjusted to 5.0 with acetic acid.

The test specimens treated with the specified "Blix" solution were then washed and dried, and it was found that positive color images were formed in them.

In a second and third series of tests, specimens A and C were used in the manner indicated produced, exposed, developed and worked up, but with the exception that the pH value of the developer solution used in the second series of experiments to 11.15 and in the third series of experiments 10.0 was set.

The photographic densities of all the images obtained were determined Results are shown in the table below

PH value the developer solution 10.0 11.3 11.15 Omar D _m , "D _max

Test item A 2J6 0.18 Test item B 2.32 0.25 Test item C 2.28 0.24

2.29

2J0

0.44
2.02

The results show that the addition of the hydrazonomethyl-substituted quaternary ammonium salts to the silver halide emulsions leads to photographic recording materials (see samples B and C), with the aid of which positive color images are advantageously also used with the use of developer solutions with a comparatively low pH value, without impairing the color density of the images obtained can be produced. If, on the other hand, conventional nucleating agents are added to the emulsions (cf. Test item A), when using developer solutions with a comparatively low pH value, the Color density of the images obtained from very strong.

Further tests showed that the advantages to be achieved according to the invention also when using internal biidemuisionen, couplers as well as developer and Treatment solutions of other types can be obtained, provided that the silver halide emulsions Hydrazone des specified type are incorporated.

Example 3

A direct positive photographic material was prepared according to the procedure described in Example 2 for the preparation of Sample A, with the exception that (a) no dye-forming coupler was used, (b) 2-methyl-3-methyl-3 in place of formyl-4-phenylhydrazine [3- (p-sulfophenylhydrazono) propyl] benzthiazolium bromide and then used in such an amount that ^{0.29 mg per m 2 of support area were} accounted for, and (c) the spectral sensitizing dye anhydro-5,5'-dichloro-9-ethyl- 3,3'-di (3-sulfopropyljoxacarbocyanine hydroxide sodium salt and then added in such an amount that ^{323 mg per m 2 of support} surface were accounted for.

After drying, the photographic material obtained was made according to the procedure in Example 1 described method exposed and developed, whereby a direct positive silver image was obtained, the qualitatively corresponded to the image obtained with the aid of test specimen 2 of Example 1. - ">

Example 4

Following the procedure described in Example 3, a direct positive photographic material was obtained produced, with the exception that as * "> Nucleating agent instead of 2-methyl-3- [3- (p-sulfophenylhydrazono) propyl] benzthiazolium bromide 1 - (p-carboxy-

phenylhydrazono) propyl-2,3,3-trimethyl-3H-indolium bromide was used in the same concentration. During exposure, development and work-up of the photographic recording material obtained a direct positive comparison was obtained, qualitatively similar to that described in Example 3 The image obtained corresponded to the recording material.

55

Example 5

Two further direct positive recording materials were prepared by the method described in Example 3, with the exception, however, that instead of 2-methyl-3- [3- (p-sulfophenylhydrazono) propyl] benzthiazolium bromide equal amounts of 2-methyl-3- [3- (p-toluenesulfonylhydrazono) pentyl] naphtho [2,1-d] thiazolium iodide and 2-methyl-3- [3H (p-sulfophenylhydrazono) pentyl] benzthiazolium iodide were used. After exposure and development, as in As described in Example 3, direct positive silver images of excellent quality were obtained.

Example 6

For the purpose of substantiating the technical progress of the recording material according to the invention compared to US Pat. No. 3,227,552, two Hydrazones of the type known from US Pat. No. 3,227,552 with two hydrazones used according to the invention compared. The compounds tested were:

l. | Benzaldehyde phenylhydrazone (U.S. Patent 3,227,552): H = N-NH

2.) Acrolein ^ -nitrophenylhydrazone (US-PS 32 27 552): CHj = CH-CH = N

3.) 2-Methyl-3- [3- (4-sulfophenylhydrazono) propyl] benzihiazolium bromide (according to the invention):

SO ₃ H

4.) 5-Methoxy-2-methyl-3- [2- (4-carboxyphenylhydrazono) propyl] benzthiazolium bromide (according to the invention):

-CH

H ₃ CO

The compounds were added to the US Patent conventional silver halide emulsions from the image type according to Example 1 25 92 259, which were so coated on a support, that a support surface of 1 m ² accounted for:

an amount of silver halide equal to 5.8 g of silver; and 43 g of gelatin.

There were also 5 mg of the compound to be tested for 1 mol of silver halide.

The test specimens were exposed to a 25 watt tungsten lamp at a distance of 030 m for 3 seconds long exposure through a step wedge. Subsequently, the test specimens were in a developer of the following composition:

15 16

Water, about 50 ° C 500 m! Developed for 3 minutes at 20 ^° C., i

p-MethylaminophenolsuliUt 2.0 g dried.

Sodium sulfite, dehydrated 90.0 g In the case of the test specimens with c

Hydroquinone 8.0 g used hydrazones (3) and

Sodium carbonate, moiiohydrate, 52.5 g were obtained. In case d (

Potassium bromide 5.0 g hydrazones (1) and (2) were k

Filled up with cold water to 1 liter of the egg, but only negative images

Claims (1)

Patent claims: 1. Photographic direct positive recording material, consisting of a layer support, at least one coated thereon, the latent image predominantly inside the silver halide grains forming silver halide emulsion layer, and optionally intermediate and / or top layers, which contains a hydrazone in at least one of the layers, characterized in that that as hydrazone it is a compound of the general formula