DE1547785A1 - Fogged direct positive silver halide emulsion - Google Patents

Description

Eastman Kodak Company, 343 State Street, Rochester, New York State, United States of America

Fogged direct positive silver halide emulsion

The invention relates to a fogged direct positive silver halide emulsion containing an electron acceptor,

The use of organic compounds as electron acceptors in direct positive photographic silver halide emulsions is known. For example, the Use of electron acceptors in fogged, direct-positive silver halide emulsions that are responsible for the Making direct positive images are described in British Patent 723 019. It has however, it has been shown that the effectiveness of the

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see patent specification 723 019 described electron acceptors is not particularly large and that the direct-positive photographic emulsions described in British patent specification 723 019 have the disadvantage that undesirable negative images are generated in areas of strong exposure The generation of negative images in exposed areas directly positive emulsion layer is known to be undesirable

The present invention was therefore based on the object of developing new, particularly effective electron acceptors which, when added to direct-positive silver halide emulsions, lead to an improvement in their properties, and in particular to prevent negative images from being formed in the areas of strong exposure when such emulsion layers are exposed .

The invention was based on the knowledge that excellent electron acceptors for direct-positive, photographic Silver halide emulsions are obtained when one known cyanine dyes with at least one Methine group halogenated by means of a halogenating compound, so that at least one hydrogen atom of a methine group is replaced by a halogen atom, namely by a chlorine, bromine or iodine atom.

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The furnace of the invention therefore leaves a veiled direct-positive silver halide emulsion containing an electron acceptor, which is characterized ₉ there is at least one electron acceptor

Compound Haloffenatoa having tyftlltllftxltlifcfttt of the following fereeln contains

X .Z ₉ ^ ^A.

R ₁ -M "(LL)" CC-6CH "CH ^ -C" (LL) = NR ₂

where mean:

Z ₁ and Z _{2 represent} the complete completion of a 5- or

6-membered heterocyclic ring required non-metallic atoms;

L is a methine group; X and X ₁ hydrogen, chlorine, bromine or iodine atoms,

with the proviso that at least one of the radicals X and X _{1 is} one of the specified halogen atoms;

R ₁ and R ₂ each represent an optionally substituted alkyl radical;

ORIGINAL! NSPECTED

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A is an acid anion and y, d, m, η and ρ each = 1 or 2.

In the electron acceptors used according to the invention

Connections are therefore XSiimmmxwwtm, which are at least have a methine group in which at least one hydrogen atom is substituted by a chlorine, bromine or iodine atom · There can be a carbon atom that represents each nucleus of the cyanine dye connects, one or two Have halogen atoms.

In the given formulas I and II, the heteroatoms of the _{5- or 6-membered heterocyclic rings formed by Z 1} and Z ₂ preferably consist of oxygen, sulfur, nitrogen or selenium atoms. Z ₁ and Z ₂ can thus form a wide variety of rings known in cyanine dyes, for example a ring of the benzothiazole series, e.g. B. a benzothiazole; ^ -Chlorobenzothlazol-; 5-chlorobenzothiazole-; 7-chlorobenzothiazole-; 4-methylbenesothiazole-; 5-methylbenzothiazole-j 5-bromobenzothiazole-; '»-Phenylbenzothiazole-; 5-phenylbenzothiazol-j 6-phenylbenzothiazol-j 4-methoxybenzothiazol-} 5-methoxybenzothlazol-; 5-iodobenzothiazole-; Ί-Xthoxybenzothiazole-j 5-ethoxybenzothiazole or 5-hydroxybenzothiazole ring; a ring of the naphthothiazole series, e.g. B. an oL-naphtothiazole; ß-naphthothiazole-; 5-methoxy-ß-naphthothiazole-j

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5-ethyl-ß-naphthothiazole-; 8-methoxy-a-naphthothiajia.- or, 7-methoxy-a-naphthothiazole ring; a ring of Benzoxazolrelhe, e.g. B, a benzoxazole; 5-chlorobenzoxazole-; 5-methylbenzoxazole-; 5-phenylbenzoxazole-; 5-methoxypbenzoxazole-; 5-ethoxybenzoxazole or 5-hydroxybenzoxazole ring; a ring of the naphthoxazole series, e.g. B, an α-naphthoxazole or β-maphthoxazole ring; a ring the benzoselenazole series, z, B, a benzoselenazole-; 5-chlorobenzoselenazoH 5-methylbenzoselenazole or 5-hydroxybenzoselenazole ring; a ring of the naphthoselenazole series, e.g. B, an o-naphthoselenazole or ß-naphthoselenazole ring; a ring of the chlnoline series including 2-ehinoline rings, e.g. B. quinoline-; 3-methylquinoline-; 5-methylquinoline-; 7-methylquinoline-; 8-methylquinoline-; 6-chloroquinoline-; 8-chloroquinoline-; 6-methoxyquinoline-; 6-hydroxyquinoline or 8-hydroxyquinoline ring, and Ί-quinoline rings, e.g., a quinoline; 6-methoxyquinoline-; 7-methoxyquinoline or 8-methoxyquinoline ring, or one Ring of the Isochlnolinrelhe, z. B. a 1-isochinoline or 3-isoquinoline ring.

The methine group represented by L may be optionally substituted; H. For example, L stands for a group of the formulas: sCH-, sCGH, -.

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R ₁ and R ₂ preferably represent short-chain alkyl radicals, ie preferably alkyl radicals with 1 to 4 carbon atoms, for example methyl, ethyl, propyl, isopropyl, butyl, sec · butyl or tert. Butyl radical or sulfoalkyl radicals old 1 to 4 carbon atoms in the alkyl group, such as sulforaethyl, sulfoethyl, sulfopropyl, sulfobutyl radicals and the like, or for example carboxyalkyl radicals, the alkyl group preferably having 1 to H carbon atoms, such as, for example, carboxyethyl radicals, carboxyethyl radicals, Carboxypropyl groups, carboxybutyl groups and the like.

A represents, for example, a chloride, bromide, iodide, p-toluenesulfonate, Kiiocyanat-, methylsulfeaate, ethyl · sulfate or perchlorate anion.

According to a particularly advantageous embodiment of the veiled, direct-positive silver halide ^{emulsion according to the invention, it contains as electron acceptor 1.1 1} → 3.3 ^t- tetramethyl-2.2 ^l -cyanine iodide in which at least one hydrogen atom of the methine chain is substituted by a bromine atom ·

According to a further, particularly advantageous embodiment, the direct-positive silver halide emulsion contains

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of the invention ale electron acceptor 3 »3 ^I -Diethylthiaeyaninjodid or 3.3 ^I -Dl * thylthiacarbocyaninjodid or 3.3 ^t -DiethylthiadiearboeyanIn ₍ iodide, whereby in all mil ·« at least one hydrogen atom of the methine chain of 4 dyes is substituted by a Broaatcai ·

In a further, beaondera advantageous embodiment, the direct-positive silver halide emulsion of the invention contains as electron acceptor 9-ethyl-3,3 ^t -diraethyl, 5 _t M *, 5 * <-dibenxothiaoarbocyaninehlorld or ^l -methyl-3- . ithjrlthia-S ^ oyaninjodid, whereby in each case at least one VasteratoffatoB the ü @ * - t $ inchain of the dyes is substituted by a Br οι to «ο

Oeatl another particularly Tortellhaften Aueführung * - containing for "the Tersehlelerten, direct-positive Silberhalogenideswlsion according to the invention, this akieptor as electron a l _e l-diethyl-2,2 '' - cyaninsals, irjdem Aat the two quinoline rings of the dye connecting carbon atom has two bromine atoms.

The silver halide grains of the fogged direct positive silver halide emulsion of the invention can be veiled using one of the known methods,

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dp h. for example by exposure to light or by the action of a wide variety of customary chemical compounds. Ale has particularly advantageous check the concealment of emulsions with a combination of a reduiierenden compound and a compound of a metal such as silver is the elektropositirer _t proven "

In a further, particularly advantageous embodiment, the silver halide mulelon contains at least predominantly grains whose core is made up of water-insoluble Silver salt with centers that promote the precipitation of photolytic silver and an outer shell of one veiled, water-insoluble silver salt that can be developed without exposure *

To conceal the silver halide grains of the direct * positive silver halide emulsion according to the invention the various known former fogging agents can be used chemically, as in for example stannous chloride, formaldehyde, thiourea dioxide and the like. The obfuscation takes place Silver halide grains with a combination of a reducing compound and a metal of a compound that is electropositive than silver have been found to be Combinations of thiourea dioxide and gold alloys, for example potassium chloroaurate, as described in British patent specification 723 * 019, has proven particularly advantageous.

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Al · reducing Schieler connections have been found In addition to stannous oxide and thioureaidoxide and formaldehyde, a wide variety of other stannous salts, Hydra "In, the most diverse other sulfur compounds, phosphoniurasalts, such as tetra (hydroxymethyl) phoaphoniumehlorld, and the like have proven to be advantageous" Typical Compounds of metals that are more electropositive than Silver »are for example gold compounds, rhodium compounds» platinum compounds, palladium compounds, Iridium compounds and the like, which are preferably used in the form of their soluble salts, such as as potassium chloroaurate, Aurichlorld, (NH ^) JPdCl ^ and the * same.

When obscuring the silver halide folder the veiling connections in the most varied of con » xentrations are applied «It has turned out to be two-way proved to be about 0.05 in obscuring the grains up to 40 mg reducing compound per mole of silver halide and 0.5 to 15 »0 mg of the noble metal compound per mole To use silver halide «It has proven to be particularly advantageous when concealing the silver * halide grains low concentrations, both the reducing compound as well as the noble * .etallver binding to apply «

BATH ORIGINAL

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OealA a special * Torteilhaft "** version" for "the

Emilion of the invention in its silver halide crystal 0.0005, preferably

■ it / 0.001 bi »O ₉ 06 ftllliequivalenten Reduktlonssehle« means and 0 _t 001 to 0.01 millimoles of a noble metal «veiled. Preferably The ratio of noble metal compound tu Reduktionsschlelermittel at If3 to 20: 1.

The concentration of halogenated cyanine dyes in of the emulsion is not critical · It has proven to be useful »about 50 to 2000 mg, preferably 400 to 800 mg, dye per mole of silver halide, see below.

As veiled la scope of the invention apply directly · * positive Silberhalogenidenulsionen »it silver halide grains, when the Eeulsion is applied to a usual support in such fttSrke, dt * on a TrfigerfWehe 0 _t 09» ² Cl sq · ft.) 50 up to 500 ag of silver do not require a "density" of at least 0.5 if they are developed for 5 minutes without exposure in a developer A with the following composition:

t'fO4

Developer & If-lletnyl-p-aainophthalene sulfate 2.5 g KatritsMulf it (anhydrous) 30.0 g Hydroquinone 2.5 g Watriuse etaborate 10.0 g Potassium broil 0.5 g Filled up with Was.er to 1.0 1,

Inthllt the SilbefhalogenideauXslon of the invention silver * helogenide grains whose core consists of a * water-insoluble Silbertal "with centers that promote the precipitation of photolytic" silver and an abundance of a veiled, water-insoluble silver corn, which is light can be developed, this is how the electrons are located akseptore »in the upper ROUe or shell the gymnast. Methods for making such emulsions are described, for example, in the OSA patent application Serial No. M8, * 67 describe · The! Kidney RSlXe or Sehale of the silver halide grains of such eeulsions This is evidenced by the fact that a light-sensitive, water-insoluble silver sausage is deposited on the core, which can then be missed, the veil again through a lead bolt can be removed * The outer cover or sehale should be of such strength that the advance

ßAD ORiGSNAL

909847/08 (H.

When developing emulsions of this kind in the core, the developer is avoided. The surface of the silver halide is veiled so that the silver halide can be developed by conventional surface developers generate about 0.5 when they are applied in the form of an emulsion to a conventional carrier in a layer thickness of 100 μg of silver per 0.09 m (1 sq. ft.) and when they are applied for 6 minutes at 20 ^° C. in one Developer A * with the following composition:

Developer A ^f 2.5 g N-methyl-p-aminophenol sulfate 10.0 g Ascorbic acid 35.0 g Potassium metaborate 1.0 g Potassium bromide 1 1 Topped up with water 9.6 PH value "

The veil can be brought about chemically by chemical sensitization to veil, namely by means of lensibllizing compounds, which are also responsible for the chemical sensitization of the core emulsion or by exposure to high intensity light and the like. The core of the silver

909847/0804 bathroom original

halogenated grain does not need to be ■ enaibilized against obfuscation. In the case of a chemleehen concealment, the use of reducing agents has become more important Sensitizers and precious metal salts, such as gold salts, or the use of sulfur sensitizers, as well as maintaining high pH values and lower pAg values in silver halide precipitation as proven to be advantageous · If necessary, dlt envelope can be used Silver halide grains become obscured after the silver halide emulsion has been applied to a support

Before the shell of water-insoluble silver salt is created on the silver salt cores, chemical * or physical pathways using known processes to generate centers which reduce the precipitation of photolytic Demand silver, d. H. so-called latent image core centers are generated. These centers can for example are generated by chemteh sensitivity processes, as described by Antolne Hautot and Henri Saubenelr in the Science et Industries Photographiques, Volume XXVIII, January 1957, pages 1 to 23, and January 1957 » Rarely 57 to 65, are such chemical

BAD OBiGlNAL

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Visual sensitization can practically be carried out by three main methods, namely by sensitization «1t gold or other precious metal compounds, through a Sulfur sensitization, i.e., for example, a sensitization with compounds that have a labile sulfur atom, and finally by a so-called reductive awareness, d. h, a · treatment of the Silver halides with a »strong reducing agent, which on de * Silbersaltkom or crystal small centers metallic silver produced,

Qemäft a particularly advantageous AusfOhrungsform the fogged, direct-positive silver halide emulsion of the invention are the silver halide grains only to the extent exacerbated Dafi a mold made of the KBfnern and coated on a support, photographlsehe silver halide emulsion when for 6 minutes at a temperature of 20 ⁰ C in a developer A su a maximum density of at least about 1 is developed, a maximum density expands which is at least about 30 % greater than the maximum density of a comparative sample which was developed under the same conditions after el 10! Uriuten at 20 ⁰ C in a bleaching solution of the following gusfunnenstt!

BADORiGlNAL

Kaliuacjranid 50 ag Blies Ig 3 _t * .7 ecm

Hatriua acetate 11.49 g

Kaliuabroaid 11 $ ag Made up to 1 liter with waiter

has been bleached.

Such dents are described in the USA patent application with the serial Ho. 539 * Mft described *

Die! Dimer such emulsions are soait to veiled weak dajleie bind ens about 25% _$ typically at least about * 0 Ji lose her veil if they "are bleached ng · This" 10 minutes at SO ⁰ C in Onea Kaliuacyanidbleichbad the specified Zattaaetuets chlelerrerlust lüt to vermnschauliehen by coating the silver halide grains in Fora a photographic Silberhalogenideeulsion to a customary Trfiger is so because "a iaaxi" ale Fichte of mindestene l} 0 struggling with a 6 Hinuten development bsi 20 ⁰ C in DEA developer a obtained and comparison of the achieved density of the material with an identical sample, which was developed for € minutes at 20 ⁰ C in the same developer A, after the tie for 10 minutes at 20 ⁰ C in a Kalluacyanldleiehbad the specified Zuaamreen-

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As already explained, the maximum density of the unbleached sample should be at least 30 % greater, preferably 60 % greater than the maximum density of the bleached sample.

The silver halide cores of the fogged direct positive silver halide emulsion of the invention can consist of the usual silver halides used for the production of photographic emulsions, d. H. for example from silver bromide, silver iodide, silver chloride, silver chlorobromide, silver bromoiodide, silver chlorobromoiodide and the like.

Particularly advantageous results are obtained with emulsions whose silver halide grains have an average * Lent grain size of 0.01 to 2 microns. Particularly advantageous results are obtained when the average grain size is below 0.5 microns

Preferably, the silver halide grains also have a regular structure, that is, particularly advantageous emulsions are those in which at least 80% by weight or 80 % of the number of silver halide grains have a regular structure; are for example cubic or octahedral. Such emulsions are

909847/080 *

weise-in the USA patent application with the Ser.No, 533 400 described.

It has also proven to be particularly advantageous if the silver halide grains are as uniform as possible in diameter, d. H. when the diameters of the silver halide grains deviate from each other as little as possible. For example, it has proven to be particularly advantageous when the fogged silver halide emulsion contains grains of which at least 95% by weight have a diameter have, which is not more than -40%, preferably around does not deviate by more than - 30% from the mean grain diameter (reference is made to the USA patent application with Ser, No. 533 440),

The fogged silver halide grains of the latter types of direct-positive photographic silver halide emulsions produce advantageously a density of at least 0.5, when they mg of an emulsion on a support in a thickness of 50 to 500 ¹ by applying in the form /

2
0.0929 m (1 sq. Foot) without being exposed, developed for 5 minutes at 20 ⁰ C in a developer A.

The mean grain diameter, i.e. the average Grain size, can be determined by known methods,

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as described, for example, in the article by Trivelli and Smith "Empirical Relations between Sensitometric and Size-Frequency Characteristics in Photographic Emulsion Series" published in "The Photographic Journal", Volume LXXIX, 1949, pages 330-338.

The silver halide grains preferably consist of at least 50 mols of bromide, the particularly preferred

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/ ν

Imften emulsions are those whose silver halide grains consist of silver halide iodide, preferably those which contain less than 1 · about 10 hol * yodel.

Photographic silver halide emulsions lateen • I do better · · apply in layer thicknesses corresponding to about 50 to about 500 mg of silver per 0.09 * ² carriers (1 eq.

Vorg * ctv * i «e« nthilts the veiled, direct-poiltire • Silver halide idea of the invention usually cu de « Electron actuator still in an ipectrally sensitizing Vartetoff, the dl · club ion against radiation fm lower shafts al · 480 «· eetuibilized.

WLe slectron acceptors become the top white of the familiar, finished silver halides uleion lugeeetit and • ollen eelbetTeretlndlich »oe possible indifferently in the ! ■ ulsion are distributed.

The electron acceptors are incorporated in the process according to methods which are known in the fields. So did • For example, it is possible to turn off the electron acceptors Solutions of emulsion luxury. Suitable solvents are, for example, propyl alcohol, methyl alcohol,

BATH ORIGINAL

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Pyridine, water and the like, these solvents optionally being used in mixtures with one another can.

The binder of the silver halide emulsion can consist of any of the usual hydrophilic colloids used for the production of photographic emulsions, for example gelatin, albumin, agar-agar, Gum arabic, alginic acid and the like, or hydrophilic synthetic polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, cellulose ethers, partially hydrolyzed cellulose acetate and the like.

Optionally, the fogged direct positive silver halide emulsion of the invention can also contain color couplers contain.

Suitable support materials for the fogged direct positive silver halide emulsion of the invention are all conventionally known support materials which are used for the production of photographic materials can, suitable. This means that, for example, films made of cellulose acetate, cellulose acetate butyrate, polyesters, such as for example polyethylene terephthalate, paper, baritized paper, coated with a polyolefin layer

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- «β—

IA

Paper, for example paper coated with a polyethylene layer or a polypropylene layer, which may optionally have been irradiated with electrons in order to improve the adhesiveness of the emulsion, and like that.

The electron acceptors used in the present invention can be easily prepared by halogenating a known cyanine dye with chlorine, bromine or iodine. For the halogenation of the cyanine dyes, the usual known halogenating compounds are used, d. H. for example aqueous-alcoholic solutions (for example Methanolic or ethanolic solutions) of halogen or a halogenating compound, such as N-chlorosuccinimide, N-bromosuccinimide, N-iodosuccinimide, or commercial halogen-pyrrolidone complexes, such as bromine-pyrrolidone complexes and the same.

By the action of such halogenating compounds if at least one hydrogen atom in the methine chain of the dyes is replaced by a halogen atom, In the case of carbocyanine or dicarbocyanines, it is also possible that a halogen substitution at the terminal Carbon atom of the methine chain enters.

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The following examples are intended to further illustrate the invention.

example 1

To 40 ml of a äthylalkoholischen solution of 5 x 10 "g of sensitizing dye l, l ^l--Diäthyl 2.2 * -cyanlnchlorid were 20 ml of an aqueous solution of 2 χ 10 g of a commercially available bromo-Pyrrolldon complex (General Aniline and Film Corp., USA). When the bromine-pyrrolidone complex solution was added, a shift occurred in which the previously red solution of the dye (absorption maximum 540 rough) turned into a blue solution (absorption maximum 590 πιμ) The dye was found to be photosensitive and was therefore made in total darkness to prevent spontaneous decay.

At the same time, a direct-positive photographic gelatin-silver chlorobromide emulsion was prepared with a Content of 60 moles of bromide and 40 moles of chloride. the The emulsion was then in a layer thickness of 250 mg of silver and 500 mg of gelatin per 0.09 m of support area (1 sq. Ft.) On a conventional film base.

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The film obtained was then exposed through a step wedge, whereupon part of the film was converted into the described Immersed the blue dye solution for 2 minutes · After drying the film in the dark, the film was exposed a second time. The film was then 1 minute long immersed in a developer B of the following composition:

Developer B

Water, 50 ° C

500 cm 3.0 G »» 5.0 ε 12.0 G 80.0 G 2.0 G 1.0 liter

N-methyl-p-aminophenol sulfate Sodium sulfite, dehydrated hydroquinone

Sodium carbonate, monohydrate potassium bromide

Topped up with water

The developer temperature was 20 ° C. The film was then fixed in the usual way.

In the areas of the emulsion layer which were exposed for the second time, there was the effect of the first exposure disappeared. When the emulsion layer was fogged uniformly before the dye treatment, it became a direct-positive image obtained by the second exposure. The emulsion layer was found to be delicate compared to radiation of M80 to 600 my with a maximum sensitivity at 590 mu.

ORIGINAL INSPSCTED 9 0 9 8 4 7/0804

Vf

No reversal images were obtained when the experiment was repeated, but the material with the ethyl alcoholic one Solution of the unbrominated dye was treated or if further the Mterial with an ethanolic Solution of the bromine pyrrolidone complex was treated

Example 2

First, a film was produced as described in Example 1, which was further exposed and developed as described in Example 1. However, this time the film material was treated with an ethanolic solution of l'-3-diethylthia-2 ^f -cyanine iodide, the halogenation of the cyanine dye taking place in the same manner as described in Example 1. The results obtained were the same as those described in Example 1.

A number of other halogenated dyes were prepared by adding dropwise a solution of 8 mg of N-bromosuccinimide (hereinafter referred to as NBS for short) per ml of methanol to a methanolic solution of a cyanine dye (8 mg of dye in 15 cm ^{3 of} methanol), until no further change in color occurred. At least one hydrogen atom in the methine chain

9Q9847 / 08CU

the paraffin was replaced by a bromine atom. The dyes produced are given in the following table, with the number of equivalents of NBS is specified.

A.!, L '^^' - tetramethyl-S ^ -cyanine iodide, 2 NBS;

B. 3,3 ^I -diethylthiacyaninjodid, 2 NBSj

C. 3,3 ^I- diethylthiacarbocyanin iodide, excess NBS;

D. 3 _> 3'-diethylthiadicarbocyanine iodide, excess NBS;

E. 3.3 ^t -diethylthiatricarbocyanine iodide, excess NBS;

P. 3,3 ^t -diethyl-9-methylthiacarbocyanine bromide, excess NBS;

G. 9-ethyl-3,3-dimethyl-4,5 ^{t, 1} i ^l, 5 ^f -dibenzothiacarbocyaninchlorid, excess NBS;

H. _l l ^t -diethyl-2,2 ».cyaninchlorid, 2 NBS;

K. 3.3 ^f -Dimethylthiacyaninbromid, INBS;

M. 3-Bromo-l, l ^t -diäthyl-2,2 -cyaninjodid ^t, 3 NBS;

N. 1,1'-Dimethyl ^, 2 • -cyanlnjodid, 3 NBS (The two The carbon atoms connecting quinoline rings of the dye have two bromine atoms.);

0. l-ethyl-l ^l -methyl-2.2 ^t -cyanine iodide, 3 NBS;

P. l ^t, 3-Dimethylthia-2 "-cyaninjodid, 2 NBS;

Q. l ^t -Xthyl-2-methylthia-2 ^l -cyanine iodide _t 2 NBS;

R. l »-Methyl-3-ethylthia-2 ^f -cyanine iodide, 2 NBS;

S. l », 3-diethylthia-2 ^f -cyanine iodide, 2 NBS;

T, 3-ethyl-3 ^t -methylthiacyanine iodide, 2 NBS.

847/0804

For comparison purposes, the following additional dyes were produced:

II 3,3 ⁱ -diethylthiacyanine iodide;

III 3,3'-diethylthiacarbocyanine iodide;

IV 3,3 * -DiethylthiadicarbocyaninJodid;

V 3,3 ^f -diethylthiatricarbocyanine iodide;

VI 3 »3 U) iäthyl-9-methylthiacar ^j boeyaiiiRbromid;

VII 9-ethyl-3,3 ^f -dimethyl- ^, 5, 4 ^f , 5 ^f -dibenzothiacarbocyanine chloride;

VIII 1,1 »diethy1-2,2 ^f -cyaninechlofrid;

IX anhydro-9-ethyl-3.3 ^l -di (3-sulfopropyl) -l », 5, ¹ » ^l , 5 ^t dibenzothiacarbocyanine hydroxide, sodium salt;

X 3,3 ^f -dimethyl-8,10-di (m-toloxy) thiacarbocyanine bromide;

XI l ', 3-diethylthia-2 ^l -cyanine iodide;

XII i | - [(1-Xthyl-2 (1H) -ß-naphthothiazolylidene) isopropylidene3-3-methyl-1- (p-sulfophenyl) -5-pyrazolone;

XIII Anhydro-9-ethyl-5,5 ^f -dipheny1-3,3 ^f -di (3-sulfobutyD-oxacarbocyanine hydroxide, monosodium salt;

XIV anhydro-5,5 ', 6,6'-tetrachloro-ljl ^ diethyl ^, 3 ^f di (3-sulfobutyl / benzimidazolocarbocyanine hydroxide;

J 5-m-nitrobenzylidene rhodanine; L phenosafranine.

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The dyes described were used in experiments in chemically fogged emulsions. The concentrations of halogenated dye given in the following examples relate to the weight of the dye before the reaction with the NBS.

From the following Example 3 it can again be seen that direct-positive images are obtained when fogged emulsions are used if they contain one of the specified halogenated cyanine dyes, but that no corresponding images are obtained when the corresponding non-halogenated cyanine dye is used.

Example 3

A gelatin-silver bromide emulsion was fogged by adding 0.2 g of thiourea dioxide per mole of silver halide to closing 60 minutes heating at 60 ° C, addition of O, ¹ »mg of potassium chloroaurate per mol of silver halide, and 60 minutes heating at 65 ° C . The emulsion was melted at ¹ IO ⁰ C and in a plurality of parts divided at, which the following electron acceptors, dissolved in a solvent, were added. The emulsions were applied to the usual cellulose acetate

90 98 Ul I 0 80 U

film support was coated such that on a support surface of O _t O9 m (sq. 1 ft.) 257 mg of silver and 392 mg gelatin accounted · The emulsion / were on the carriers allowed to solidify and dried up ·

Subsequently, samples were the resultant films in a Sensitoneter Tom type Eastman IB by means of light from a tungsten lamp that has been modulated by a continuous wedge, exposed, whereupon the Pilmproben developed for 5 minutes in a developer A at 20 ⁰ C, were fixed, washed and dried . The following results were obtained:

Brominated dye density of the unbelich- D_ _ ₄ in exposed areas

A. (0.2) B. H C. ff D. ff E. ff F. N G ff H ff

0.92 0.1

0.82 0.06

0.79 0.12

0.5 0.26

0.7 0.09

0.3 0.12

0.36 0.14

1.26 0.06

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dye
(Conc. G / mol silver halide)

Results

I. (0.2) No reverse negative image Unsensitized comparison sample II η dd III η Il IV η It V η It VI It It VII ti It VIII It It

The inactivity of N-bromosuccinimld in disguised Gelatin silver halide emulsions exposed and developed as described in Example 3 give result from the following results:

Emulsion type

bromide

Chlorobromide

additions

(Conc. In g / mol silver halide)

no

N-bromosuccinimide

(0.098) N-bromosuccinimide

(0.196)

no

Results

No reverse negative, just a picture

909847/0804

The following example 4 describes the spectral sensitization a fogged direct positive silver halide emulsion according to the invention with a spedctral sensitizing dye.

Example 4

The procedure described in Example 3 would be repeated with the exception, however, that sensitizing dyes were additionally added to the emulsion. For determination A Wratten No. 16 filter was used for spectral sensitization. A comparison of the results obtained shows the superiority of brominated dyes as electron acceptors.

Electro * en accept »r (conc. G / mol silver halide)

no

Sensitizing density of Wratten dye
(Conc. G / Mol
Silver halide)

no

IX (0.2)

X (0.2)

VIII (0.0875) ♦

XI (0.0875) +

XII (0.025)

unexposed
Districts

1.16 0.88 0.70 0.83

Filter # 16; the districts did not reverse the picture

9098A7 / 0804

K (0.2)

J (0.2)

K (0.2)

No XIII (0,1) ♦
XIV (0.1) 1.07 no reverse J (0.1) no 0.89 η K (0.2) no 0.9 η J (0.2) IX (0.2) 0.71 η K (0.2) IX (0.2) 0.82 0.16 J (0.2) X (0.2) 0.19 0.21 K (0.2) X (0.2) 0.70 0.19 J (0.2) VIII (0.0875) ♦
XI (0.0875) f
XII (0.025) 0.66 0.29

VIII (0.0175) ♦ 0.96

XI (0.0875) ♦

XII (0.025)

XIII (0.1) ♦ 0.69

XIV (0.1)

XIII (0.1) ♦ 0.73

XIV (0.1)

0.21

no reverse image

0.37

Example 5 below illustrates the use of various electron acceptors in a veiled Silver chlorobronide emulsion

Example 5

The procedure described in Example 3 was repeated? However, a gelatin-silver chlorobromide emulsion of the type described in Example 1 was used,

909847/0804

τα

In addition, the obtained films were for 6 minutes / one Developer C of the following composition developed at 20 ^° C.:

Developer C

Water, 50 ^° C

N-methyl-p-aminophenol sulfate Sodium sulfite, dehydrated Hydroquinone Sodium carbonate, monohydrate Potassium bromide Topped up with cold water

The test specimens were then fixed in a known manner.

From a comparison of the results obtained for electron acceptors J and L with the results for the brominated sensitizing dyes M - T, K, C and H clearly demonstrates the superiority of the brominated dyes.

500 cm ³ G 2.0 G 90.0 G 8.0 ε 52.5 G 5.0 liter 1.0

909847 / 08CU

Electron density of the Dmin ^playback in

acceptor exposed- exposed areas star-

(Konzi g / Mol th districts ker exposure

Silver halide) districts (no filter)

no
(Comparison sample) please refer below 0.62 Negative picture J (0.2) 0.85 0.51 η J (0.1) 1.07 0.78 η L (0.2) 1.65 0.07 Minimum density H (0.2) 1.03 0.08 n M (0.2) 1.11 0.08 η N (0.2) 0.88 0.08 η 0 (0.2) 0.89 0.12 η P (0.2) 0.77 0.21 π Q (0.2) 0.70 0.11 η R (0.2) 0.63 0.14 η S (0.2) 0.75 0.16 π K (0.2) 1.49 0.08 η T (0.2) 1.00 0.52 11 C (0.2) 1.38

The comparison sample shows an increase in density on exposure (negative image), which increases through a maximum runs and then abnirant (solarization). In contrast, the emulsions of the invention initially show a drop the density during exposure. The reverse effect, the at high exposure with the electron acceptors J and L of the prior art, occurs when using of the brominated dyes.

909847/080 *

Example 6

The procedure described in Example 3 was repeated, but this time developer C was used to develop. The superiority results from the experiments of the brominated dyes in a coarse-grained gelatin-silver bromide emulsion which has been sensitized by means of a reducing compound and a gold compound.

Electron Acceptance D.
(Conc. G / Mol
Silver halide) Relatively sensitive
speed (1.0 over min, -
Density) 2, γ Minimum-
density L (0.2) 100 2, 16 0.12 H (0.1) 276 2. 5 0.04 K (0.1) 162 76 0.06

The following Example 7 illustrates the use of a direct positive silver halide emulsion having silver halide grains having a core of a water-insoluble silver salt and an outer shell or Shell made from a veiled, water-insoluble silver salt that develops into silver without exposure, the emulsion containing a halogenated dye according to the invention. Example 7 also shows the production such an emulsion described.

909847 / Q8CU

Example 7

First, a gelatin-silver chloride emulsion was prepared by simultaneously adding a silver nitrate solution and a sodium chloride solution within 20 minutes 70 ° C. were added to a gelatin solution. The emulsion obtained was then cooled, whereupon 0.2 g of potassium chloroiridite per mole of silver was added. The emulsion was then heated again to 70 ° C., whereupon an acid nitrate solution and a sodium chloride solution were added again within 20 minutes. The emulsion then became cooled to 40 ° C and by adding 4.0 mg of thiourea dioxide and 4.0 ml of 2.5 normal sodium hydroxide solution veiled per mole of silver. The emulsion was then acidified and further gelatin was added so that the total amount of gelatin is 160 ° gelatin per mole of silver fraud. The emulsion was then spectrally sensitized by adding 200 mg of the dye Z per mole of silver. The dye Z consisted of 3-carboxymethyl-5- [(3-methyl-2-thiazolidinylidene) -1-methylethylidene rhodanine.

100 mg of compound H were added to part of the emulsion added per mole of silver. The emulsions were then coated on cellulose acetate film backing in such a manner that on a support area of 0.09 m (1 sq. ft.) 120 mg They were omitted. Subsequently, the obtained Films exposed in an Eastman IB sensitometer

9098 4 7/0804

15A7785

and then in a developer for 1 1/2 minutes the following composition:

N-methyl-p-aminophenol sulfate 3.0 g Sodium sulfite (anhydrous) ^ 5.0 g Hydroquinone 12.0 g Sodium carbonate, monohydrate 80.0 g Potassium bromide 2.0 g Made up to 2 liters with water The following results were obtained: Relative D D. Additions Sensitivity ^raa * ^min

200 mg Z / mole silver 100 1.20 0.04

200 mg Z / mole silver +

100 mg H / mole silver 289 1.22 0.05

Example 8

The procedure described in Example 7 was repeated, With the exception, however, that no potassium chloroiride was added during the preparation of the emulsion. The results obtained are compiled in the following table

909847 / QSCU

Max ^D min 0.66 0.04 0.64 0.04

Relative
Accessories sensitivity

200 mg Z / mole silver 100

200 mg Z / mole silver +

100 mg H / mol silver 63IO

Other methods of making an emulsion of the type described in Examples 7 and 8 are, for example in U.S. patent application serial no. 448 467.

The fogged, direct-positive silver halide emulsion of the invention can be incorporated with the usual additives, such as hardeners, plasticizers and the like. As described in columns 12 and 13 of FIG U.S. Patent 3,039,873. In addition, when preparing the emulsion, the in this patent described hydrophilic colloids can be used as binders.

909847 / 08Oi

Claims (1)

PATENT CLAIMS ssssssrsssssss Γ "IJ Fogged direct positive silver halide emulsion containing an electron acceptor, thereby characterized that they.as an electron acceptor a min Compound at least one halogen atom containing e $ ** X * £ ** K ** fif £ der contains the following formulas: II R ₁ -N = (LL) = CC ^ CH = CH) -C = (1, -L) = NR, 1 I y ² where mean: Z, and Z- which complete a 5- or 6-member rigen heterocyclic ring required non-metallic atoms; L is a methine group; 909847/0804 X and X ₁ hydrogen, chlorine, bromine or iodine atoms, with the proviso that at least one of the radicals X and X _{1 is} one of the specified halogen atoms; R ₁ and R ₂ each represent an optionally substituted alkyl radical; A is an acid anion and y »d, m, η and ρ each * 1 or 2. 2 · Versehleierte, direct-positive silver halide emulsion according to claim 1, characterized in that it contains as electron 1,1 ', 3,3 * ^f -Tetramethy1-2,2 -cyanin iodide, in which at least one hydrogen atom of the methine chain by a bromine atom is substituted, contains. 3. Fogged, direct-positive silver halide emulsion according to claim 1, characterized in that it contains, as electron acceptor, 3,3 ^I -diethylthiacyaninjodld in which at least one hydrogen atom of the methine chain is substituted by a bromine atom. Ί. Fogged direct positive silver halide emulsion according to claim 1, characterized in that it has 3 · 3 * -Diethylthiacarbocyaninjodid, in which at least one hydrogen atom of the methine chain is substituted by a bromine atom. 909847 / Q8Q4 5. Fogged, direct-positive silver halide emulsion according to claim 1, characterized in that it contains as electron acceptor 3,3 ^i- diethylthiadicarbocyanine iodide in which at least one hydrogen atom of the methine chain is substituted by a bromine atom. 6. Fogged, direct-positive silver halide emulsion according to claim 1, characterized in that it is the electron acceptor 9-Äthy1-3,3 ^f -dimethyl-i, 5, ¹ J ^f , 5 ^f -dibenzothiacarbocyaninchlorid, in which at least one hydrogen atom of Methine chain is substituted by a bromine atom, contains. 7. Fogged, direct-positive silver halide emulsion according to claim 1, characterized in that it is the electron acceptor ^l -methyl-3-ethylthia-2 ^f -cyanine iodide, in which at least one hydrogen atom of the methine chain is substituted by a bromine atom. 8. Fogged, direct-positive silver halide emulsion according to claim 1, characterized in that it contains, as electron acceptor, a l, l-diethyl-2.2 ^l -cyanine salt in which the carbon atom connecting the two quinoline lengths of the dye has two bromine atoms. 909847 / Q8Q4 9. ¥ produced, direct-poeitive silver halide emulsion according to claims 1 to 8, characterized in that it contains superhalide grains whose core consists of a UJBj water-soluble silver salt with centers that support the precipitation of photolytic silver, and an outer shell consist of a veiled water-insoluble silver salt that can be developed without exposure. 10. Fogged direct positive silver halide emulsion according to claims 1 to 9, characterized in that the silver halide grains of the emulsion are protected by a reducing fogging agent and a compound of a metal more electropositive than silver are veiled. 11. Fogged, direct-positive silver halide emulsion according to claims 1 to 10, characterized in that the Silver halide grains are obscured by a reducton fogging agent and a gold compound. 12. Fogged, direct-positive silver halide emulsion according to Claims 1 to 11, characterized in that the silver halide grains of the emulsion with} öi $ Ü & up to 0.06 Milliequivalents of reductant fogging agent and 0.001 to 0.01 millimoles of a compound of a metal that is more electropositive than silver. 909847/080 * 13 · Fogged, direct-positive silver halide emulsion according to Claims 1 to 12, characterized in that the silver halide grains of the emulsion with a compound of a metal that is more electropositive than silver, and a reducing fogging agent in a ratio of 1: 3 to 20: 1. 14. Fogged direct positive silver halide emulsion according to claims 1 to 13, characterized in that the silver halide consists of at least 50 mol of bromide consists. 15. Fogged, direct-positive silver halide ^{emulsion according to claims 1 to I 1} I, characterized in that it contains, in addition to the electron-accepting compound, a spectrally sensitizing dye which senslbllert the emulsion to radiation of waves longer than 480 my. 16. Fogged, direct-positive silver halide emulsion according to Claims 1 to 15, characterized in that the silver halide grains with thiourea oxide and Potassium chloroaurate are veiled. 909847/0804 17 · Mislaid, direct-positive silver halide emulsion according to claims 1 to 16, characterized in that the silver halide are only fogged to the extent that a silver halide photographic emulsion prepared from the grains and coated on a support, if for 6 minutes at a temperature of 20 ° C in a developer of the following composition: Water, 52 ° C 500 cnr N-methyl-p-aminophenol sulfate 2.5 g Sodium sulfite (dehydrated) 30.0 g Hydroquinone 2.5 g Sodium metaborate 10.0 g Potassium bromide 0.5 g Topped up with water 1.0 liter is developed to a maximum density of at least about 1, has a maximum density that is at least about 30 % greater than the maximum density of an equivalent sample developed under the same conditions after being in a bleach bath for 10 minutes at 20 ° C following composition: Potassium cyanide 50 rag Glacial acetic acid 3.47 cm ⁵ Sodium acetate 11.49 g Potassium bromide 119 mg Made up to 1.0 liter with water has been bleached. 9098 A.7 / 0804 18. Fogged, direct-positive silver halide emulsion according to claims 1 to 17 «characterized in that at least 80% by weight or 80 % of the number of silver halide grains have a regular cubic structure · 19 · Fogged, direct-positive silver halide multlon according to Claims 1 to 18, characterized in that it contains fogged silver halide grains, of which at least 95% by weight have a diameter which does not deviate by more than -40% from the mean grain diameter. 20. Fogged, direct-positive silver halide _{emulsion according to Claims 1 to 19 (} characterized in that at least 80% by weight or 80 % of the number of the silver halide grains have a regular structure. 21. Fogged direct positive silver halide emulsion according to claims 1 to 20, characterized in that the mean particle diameter of the silver halide grains 0.01 to 2 microns. 9847/0804