JPH0843971A - Silver halide emulsion containing platelike crystal and its processing method - Google Patents

Abstract

PURPOSE: To lower pressure sensitivity and to prevent the generation of pressure marks at the time of use in rapid processing by incorporating specific tabular grains contg. colloidal silica as protective film colloid. CONSTITUTION: This silver halide emulsion contains the tabular grains contg. the colloidal silica sol as the protective colloid. The tabular grains have an average grain thickness of <=0.3μm, an average aspect ratio higher than 12:1 and the degree of covering power by the silica sol grains within a range of 50 to 2000%. Further, the photosensitive tabular silver halide grains covered with the silica grains has preferably the degree of the covering power within a range of 75 to 500%. The grains having the silica as the protective colloid preferably have an average grain thickness of <=0.2μm. The total projection area of the tabular grains is preferably at least 70% and the total projection area of at least 90% is mode preferable. The tabular grains covered with the silica grains is preferably a silver halide compsn.

Description

Detailed Description of the Invention

FIELD OF THE INVENTION The present invention relates to a silver halide emulsion containing tabular crystals, a method for producing the same, and a light-sensitive photographic material containing the emulsion.

BACKGROUND OF THE INVENTION In forming silver halide emulsions containing tabular crystals, the effects of various precipitation conditions have long been known and greatly studied by those skilled in the art of tabular grains. . 19
As early as 61 years, Berry et al.
ience and Engineering, Vol 5, No. 6 announced the production and growth of tabular silver bromoiodide grains. Focal Press 1
966, by Duffin, Photographic Emulsion Che
A paper on tabular grains can be found on pages 66-72 of mistry. Previous patent documents include US-P 406395.
1, US-P40677739, US-P415099
4, US-P4184877 and US-P418487.
Including 8. However, the tabular grains described therein cannot be recognized as exhibiting a high diameter to thickness ratio, commonly referred to as the aspect ratio. Many US patent applications published in 1981 and published in 1984, eg US-P 4434226, US-P 4439.
520, US-P4425425, US-P44254.
26 and US-P 4,433,048, tabular grains with high aspect ratios and their advantages in photographic applications have been published. For a survey of high aspect ratio silver halide emulsions, see Ressarch Disclosure, Vol.
225 (January 1983), item 22534.

The aforementioned references to tabular grains are primarily concerned with high speed silver bromide or silver iodobromide emulsions.

Recent patent applications have aimed at emulsions containing tabular crystals rich in silver chloride. Therefore, precipitation conditions involving ammonia, as described in US Pat. No. 4,399,215, resulted in fairly thick tabular grains. A feature of the preparation of emulsions containing tabular grains rich in silver chloride lies in the use of grain growth modifiers as described in US Pat. No. 4,440,633, in which specific peptizers having thioether bonds and Preparation of a novel crystallographic morphology of tabular silver halide grains rich in silver chloride by precipitation in the presence of an aminoazaindene growth modifier (adenine is the preferred one) is described. . Furthermore, US Pat. No. 4,804,621 describes a process for preparing tabular grains rich in silver chloride in the presence of an aminoazapyridine growth modifier represented by the general formula, in which EP application 4811133 is used.
And 532801, except for adenine and its derivatives.

US Pat. No. 4,713,323 describes the important role of protective colloids used during the precipitation of emulsions containing tabular grains enriched in silver chloride: 1 g of oxidized methionine containing less than 30 micromoles of methionine. The presence of gelatin in the reaction vessel is of decisive importance. The same conditions for gelatin in the conditions for use in making emulsions are described for AgBr (I) tabular grains, for example as in US Pat. No. 4,713,320. The degree of oxidation of the protective colloid can be used to control the tabularity of such grains. Alternatively, it is generally known that the use of phthalated gelatin, for example, as a protective colloid has a strong effect on the reduction of the percentage of total projected area represented by said tabular grains.

The protective colloid added further before coating the hydrophilic colloid layer on a suitable support and used as a binder further determines the physical properties of the coated film material formed. Properties such as dimensional stability after processing, scratch resistance, curl, pressure sensitivity and sludge formation are highly dependent on the choice of protective colloid. Phenomena such as pressure sensitivity can appear as pressure marks, pressure sensitizations or desensitizations, where both the protective colloid and the coated matrix are subject to deformation by treatment and by treatment and in the packaging before and after exposure. You must dissipate the energy produced by the pressure you receive. In the dry state, pressure sensitization or desensitization can occur. Crystals with cubic or tabular habit are usually very sensitive to pressure sensitization.

Furthermore, thinly coated layers, for example for rapid processing, by coating with a small amount of binder, suffer from this drawback, especially for materials coated from layers with thin tabular silver halide grains. Try to make it worse.

Since the adsorption of the protective colloid takes place on the crystal surface, the development properties are further influenced by said protective colloid. In the wet state, the pressure sensitization of the film material is
It is related to the susceptibility of the coated layer to scratches and thus to the degree of curing or crosslinking of the binder material. This development is commonly referred to as the "roller mark" or "pressure mark" phenomenon.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide emulsions containing silver halide tabular grains which exhibit improved pressure sensitivity and methods of making the emulsions.

The present invention is also directed to providing a photographic material containing layers coated from emulsions containing tabular grains which exhibit negligible pressure marks for use in rapid processing.

Other objects will become apparent from the description below.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided a photosensitive silver halide emulsion comprising tabular grains containing colloidal silica sol as a protective colloid, said tabular grains having an average grain thickness of 0.3 μm or less. , An average aspect ratio greater than 12: 1, and 5
It has a coverage degree with silica sol particles in the range of 0-2000%.

In accordance with the present invention, there is further provided a method of making an emulsion comprising said tabular grains having colloidal silica as a protective colloid, comprising the following steps:

(A) Except for ammonium compounds, in the presence of onium compounds, but in the absence of gelatin,
Precipitating silver halide by the double-jet or triple-jet method applied to an aqueous solution of silver nitrate and a halide salt in colloidal silica having an average particle size in the range of 0.003 μm to 0.30 μm, wherein said colloid The weight ratio of silica to said onium compound is between 3 and 400,

(B) by varying the flow rate of said aqueous solution of silver nitrate and halide salt and / or at a constant pA during the process.
controlling nucleation process and growth process by g value,

(C) at least one physical aging step,

(D) desalting the reaction medium and redispersing the silver halide,

(E) a step of chemically ripening silver halide crystals, and

(F) adjusting the weight ratio of colloidal silica to the amount of silver halide expressed as equivalent to silver nitrate at any time throughout the precipitation step to a value of at least 0.03.

Further according to the invention, in addition to the above steps,
The ratio of silica to silver halide expressed as silver nitrate is comprised between 0.03 and 0.30 and the ratio of hydrogen bridge forming polymer to silver halide expressed as equivalent of silver nitrate is at most 0.40. A method is provided that includes the steps of redispersing and adding a controlling amount of hydrogen cross-linking polymer and / or colloidal silica to a chemically aged emulsion.

The present invention also provides a support, and silver halide provided thereon with at least one hydrophilic colloid layer containing at least one light sensitive emulsion containing tabular silver halide grains prepared according to the present invention. Photosensitive photographic materials are also provided.

DETAILED DESCRIPTION OF THE INVENTION The tabular silver halide grains have a diameter between a circle having two parallel faces and having the same area as those faces, and a thickness which is a distance between the two main faces. Ratio of at least equal to 2: 1.

For radiography, the main photographic advantage of tabular grains compared to conventional spherical grains is their high covering power at high precuring levels, especially their high sharpness in double-side coated spectral sensitized materials. High developability.

The tabular grains, especially the light-sensitive silver halide emulsions containing said tabular grains according to the invention, have an average aspect ratio of greater than 12: 1 in the presence of colloidal silica sols as protective colloids which cover their crystal faces. , 0.
It has characteristics of an average particle thickness of 3 μm or less, and a degree of coverage with silica sol particles within a range of 50 to 2000%.

Silica sols for use as protective colloids in the preparation of silver halide emulsions containing tabular grains according to the present invention are commercially available, eg Syton silica sols (trademark product of Monsanto Inorganic Chemical Div.),
Ludex silica sol (du Pont deNemours & Co. Inc.
Products of Nalco and Nalcoag silica sol (NalcoC
hemical Co.), Snowtex silica sol (Nissan Chemical KK) and Kieselsol, Type 100, 20.
There are 0,300,500 and 600 (trademark products of Bayer AG). The size of silica sol particles is 3 nm to 30 nm
Range. Small particles in the range of 3 nm to 0.3 μm are preferable because the achievable degree of covering power per 1 g of silica sol is high and the protective action of colloidal silica is more efficient.

Since thinner tabular grains provide the above-mentioned advantages to a large extent, grains having silica as protective colloid according to the present invention preferably have an average grain thickness of 0.2 μm or less. Since thinner silver halide emulsion grains containing silica exhibit higher aspect ratios, average aspect ratios of at least 8: 1 and up to 12: 1 are readily obtainable, and thus for grains according to the present invention. Average aspect ratios greater than 12: 1 are preferred.

The above-mentioned covering power was measured as follows. From the electron micrographs taken from silver halide tabular grains with silica as protective colloid, the average crystal diameter and the average grain thickness of circles having a plane equal to the crystal plane can be calculated. Further, the amount of silica effectively adsorbed on the crystal planes can be determined from the calculation after measurement of the loss of silica detected in the wash water of the emulsion containing silver bromide or silver bromoiodide tabular grains. The calculated surface of the adsorbed silica sol particles having a well-measured particle size per square unit of tabular grain determines the coverage of the grain. In a preferred embodiment, the photosensitive tabular silver halide grains coated with silica grains according to the present invention have a coating power in the range of 75 to 1500%.

For emulsions containing silver halide tabular grains coated with silica grains suitable for use in photographic materials, a total projected area of at least 70% of said grains is highly preferred and at least 90%. The total projected area of is even more preferred.

Emulsions containing tabular silver halide emulsion grains coated with silica grains according to the present invention include, for example, silver chloride,
It preferably has a silver halide composition such as silver chlorobromide, silver chlorobromoiodide, silver chloroiodide, silver bromide, or silver bromoiodide.

Iodine ions are available, for example, on October 2, 1993.
EP applications 93203040.6 and 1993 filed on 9th
EP applications 93202899.6 and EP-A561415, EP-A563701, EP filed on October 15, 2010
Can be provided by organic compounds and / or inorganic iodide salts which release iodide ions as described in A563708. Iodide ion concentrations up to 10 mol% can be present, but concentrations up to 3 mol% are particularly preferred.

The preparation of the photosensitive tabular silica silver halide emulsion according to the present invention comprises the following steps:

(A) 0.003 in the presence of onium compounds, except for ammonium compounds, but in the absence of polymer compounds capable of forming hydrogen bridges with colloidal silica.
precipitating silver halide by a double-jet or triple-jet method applied to an aqueous solution of silver nitrate and a halide salt in colloidal silica having an average particle size in the range from μm to 0.30 μm, for the onium compound The weight ratio of the colloidal silica is between 3 and 400,

(B) by varying the flow rate of said aqueous solution of silver nitrate and halide salt and / or at a constant pA during the process.
control of nucleation and growth process by g value,

(C) at least one physical aging step,

(D) Desalting the reaction medium and redispersing the silver halide,

(E) a step of chemically ripening silver halide crystals,

(F) adjusting the weight ratio of colloidal silica sol to the amount of silver halide expressed as the equivalent of silver nitrate to a value of at least 0.03 at any time during the precipitation stage.

During precipitation of silver halide crystals in colloidal silica as protective colloid, EP-S 392092
There is a need for onium compounds as co-stabilizers for colloidal silica as described in (which is incorporated herein by reference).

Prior to the onset of precipitation of silver halide tabular crystals in the presence of colloidal silica, it is preferred, but not necessary, for the agglomerates of colloidal silica to be present with the onium co-stabilizing compound. The agglomerates likewise act as protective colloids for silver halide nuclei which are formed like gelatin, for example. According to the present invention, it is necessary to add a colloidal silica sol together with an onium compound immediately after the nucleation step in order to stabilize the formed nuclei of tabular grains containing silica as protective colloid and the subsequent growth step. .

Less than 10% by weight of the total amount of silver nitrate, more preferably 0.5 to 5.0% by weight, is added during the nucleation step, which comprises silver halide and silver nitrate at a pBr of at least 2.0. It preferably comprises addition by the double jet method.

Controlling at least one of the parameters such as temperature, flow rate of the solution containing silver and halide salts, pAg value, and amount of crystal growth modifier, if present, is formed during the nucleation step. It should be recommended to determine the number of nuclei formed and to predict the average grain diameter of silver halide tabular grains having colloidal silica as a protective colloid at the end of the precipitation step.

Under these well-defined conditions, the tabular grains had 0.15 (very monodisperse) and 0.45
It can have a monodisperse or heterogeneous dispersion distribution with a coefficient of variation (ratio of standard deviation to mean crystal diameter) varying between (more heterogeneous dispersions). Furthermore, the addition of silica to the precipitation vessel may be necessary during subsequent precipitation steps, for example after the nucleation step, before growing the nuclei, during physical ripening or even during the growth process. The amount of silica and, if desired, the onium compound added can be added to the reaction vessel continuously or in one or more portions in a triple jet precipitation apparatus.
Particularly preferred is addition, for example during the so-called Ostwald ripening stage, before the flow rate of the silver and / or halide solution is increased in the double jet precipitation apparatus.

As the onium compound excluding ammonium compounds such as ammonium bromide, the following compounds represented by the following general formula can be used:

[0044] A ⁺ X ^-

[0045] In the formula X ^- represents an anion,

A ⁺ represents an onium ion selected from any of the following general formulas:

[0047]

Embedded image

Each of R ¹ and R ³ is the same or different,
Hydrogen (except for ammonium), alkyl groups,
Represents a substituted alkyl group, a cycloalkyl group, an aryl group, or a substituted aryl group,

R ² represents any of the above groups represented by R ¹ and R ³ or represents the atom necessary to close the heterocyclic nucleus with either R ¹ or R ³ .

The onium ion is 1) via a polymer chain, or 2) via any other divalent organic linking group of such an onium structure, such as --O--, --S--, --SO _2-, 3). Directly bonded to any of the groups represented by R ¹ .

A preferred example of the onium compound is US-P3.
017270. In the above specification, trialkylsulfonium salts, polysulfonium salts, tetraalkyl quaternary aluminum salts, quaternary ammonium salts (where the quaternary nitrogen atom is part of the ring system), cationic polyalkylene oxide salts such as tetra Those containing quaternary ammonium and phosphonium and bis-quaternary salts are mentioned.

Onium salt polymers whose onium groups can be, for example, ammonium (excluding inorganic ammonium compounds), phosphonium or sulfonium groups are described in US-P4.
525446. Said onium compound acts as an effective stabilizer of the colloidal stability of silica-coated silver halide tabular crystals if added in a suitable amount to the reaction vessel relative to the amount of silica present according to the invention.

According to the present invention, photographic emulsions containing silver halide tabular crystals coated with silica grains can have a homogeneous or heterogeneous silver halide distribution within the crystal volume. A heterogeneous halide distribution can be obtained, for example, by adding halogen ions, which give less soluble silver salts, on the existing tabular core, by a conversion step or by the application of a growth step with a different halide composition. In the case of a heterogeneous distribution of halogen ions, a multilayer grain structure is obtained. To obtain silica tabular emulsion crystals according to the present invention, the tabular shape must be maintained in this case.

What the crystal is a dopant, for example R
It may be further doped with a dopant such as h ³⁺ , Ir ⁴⁺ , Cd ²⁺ , Zn ²⁺ , Pb ²⁺ .

During the precipitation, a particle growth inhibitor or accelerator is added.
It can be added to obtain crystals with a preferred average crystal size of 0.05 to 5 μm. Examples of particle growth promoters are, for example, compounds bearing thioether functional groups.

The growth of nuclei formed during the nucleation step is controlled by controlling the preferred increasing rate of addition of silver nitrate and halide salts in order to produce a predictable distribution of emulsion crystals containing tabular silica silver halide. It is important to avoid re-nucleation during the process.

The silver halide nuclei can be formed in a separate vessel and added to the reaction vessel in which the growth step is carried out. Additional amounts of silica and onium compounds can be present in the reaction vessel.

According to the invention, the silver and halide salt solution is added to a concentrating vessel if the concentration of the onium compound and silica that make up the "protective network" for the silver halide crystals formed is applied. be able to.

Therefore, contrary to the examples given in EP-A 528 476, from 0.5 mol to 4 mol of silver halide
Concentrations of up to mol, more preferably 1 mol to 3 mol, can be obtained in the reaction vessel at the end of precipitation.

Another advantage associated with this is, for example, EP-
Coagulation washing as described for emulsions with silica as protective colloid, as described in A517961, and subsequent redispersion is not necessary. In a preferred example, according to the invention, the desalting of the emulsion is carried out by ultrafiltration, which can be applied without complications to post-processing fog level or pressure sensitivity.

Further steps after precipitation, desalting and redispersion of the silver halide emulsion, followed by chemical ripening, provide an emulsion which can be prepared for coating in the light-sensitive photographic layer of a silver halide photographic material. To do.

The photosensitive emulsion containing tabular silver halide crystals having silica as protective colloid prepared according to the present invention is a so-called basic emulsion after redispersion. However, said emulsions are for example prepared by P. Glafkides Chimie et
Physique Photographique, Photog by GF Duffin
by raphic Emulsion Chemistry, VL Zelikman, etc.
Making and Coating Photographic Emulsion and Akademische Verlagsgesellschaft 1968, edited by H. Frieser Die Grundlagen der Photograp
It can be chemically sensitized as described in hischen Prozesse mit Silberhalogeniden. As described in these documents, chemical sensitization can be carried out by aging in the presence of a compound containing a small amount of sulfur such as thiosulfate, thiocyanate, thiourea, sulfite, mercapto compound and rhodamine. . The emulsions may also be gold-sulfur ripening or reducing agents such as GB-.
It can also be sensitized with tin compounds, amines, hydrazine derivatives, formamidinesulfinic acid and silane compounds as described in A789823. Chemical sensitization can also be performed with a small amount of Ir, Rh, Ru, Pb, Cd, Hg,
It is also possible to use Tl, Pd, Pt or Au.
One of these chemical sensitization methods or a combination thereof can be used. The mixture can also be made up of two or more separately precipitated emulsions that have been chemically sensitized prior to mixing them.

According to the invention, chemical ripening is carried out before, during or after spectral sensitization. In conventional emulsion methods, spectral sensitization has traditionally been followed by completion of chemical sensitization. However, in the context of tabular grains, spectral sensitization can be carried out simultaneously with or completely prior to the chemical sensitization step: chemical sensitization after spectral sensitization is one or more regular tabular grains. It is believed that this occurs at discrete positions. This can also be done with the emulsions of the invention, where chemical sensitization is achieved by one or more phenidones and derivatives, dihydroxybenzenes such as hydroquinone, resorcinol, catechol and / or derivatives thereof, one or more stable. Performed in the presence of an agent or antifoggant, one or more spectral sensitizers or a combination of the above components.

Photosensitive emulsions containing silver halide tabular crystals with silica as protective colloid made according to the present invention are described by John Wiley & Sons, 1964, FM Ha.
by mer The Cyanine Dyes and Related Compounds
It can be spectrally sensitized with methine dyes such as those described in. Dyes that can be used for spectral sensitization include
Cyanine dye, merocyanine dye, complex cyanine dye,
Includes complex merocyanine dyes, hemicyanine dyes, and hemioxonol dyes. Particularly valuable dyes belong to the cyanine dyes, merocyanine dyes and complex merocyanine dyes. A survey of useful chemistries and particularly useful examples of spectral sensitizing dyes in the context of tabular grains is provided in Research Disclosure Item 22534, supra.

In a preferred embodiment, the tabular silver halide emulsion crystals according to the invention are spectrally sensitized with at least one dye having a structure corresponding to general formula (I) below:

[0066]

Embedded image

In the formula, Z represents a nitrogen atom or an oxygen atom, and when Z is a nitrogen atom, it is substituted with R ″.

R, R'and R "each independently represent a substituted or unsubstituted alkyl group,

R ″ ″ represents hydrogen, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group,

T and T'each independently represent a conventional substituent known to those skilled in the art,

(X ⁻ ) _p represents a negatively charged atom or a group of atoms for compensating for the positive charge present on the dye,
(M ⁺ ) _q represents a positively charged atom or a group of atoms for compensating for the negative charge present on the dye, and p and q each represent an integer for obtaining an electronically neutral compound.

[0072] Preferred spectral sensitizers suitable for use with emulsion crystals according to the present invention, R '''is -C ₂
H ₅ and Z is an oxygen atom, and at least one of R and R ′ is (1) preferably of the formula — (CH ₂ ) _n SO ₃ ^— (n equals 2, 3 or 4) — (CH _{2 ) 2 -CH (CH 3) -SO} 3 - and _{-CH 2 -CHY-CH 2 -SO 3} - (Y is -OH or C
(representing 1)); (2) preferably a sulfatoalkyl group corresponding to formula — (CH ₂ ) _n OSO ₃ ^— (n is equal to 2, 3 or 4); (3) preferably the formula _{- (CH 2) n -C (} O) -N (R '''') - SO 2
_{- (CH 2) m H (} n equals 1, 2 or 3, m is equal to 1, 2, 3, _{etc.), - (CH 2) r} -SO 2 -N (R '''') - SO _2-
(CH ₂ ) _s H (r is equal to 2, 3 or 4 and s is 1,
Equals like _{2,3), - (CH 2)} v -SO 2 -N (R '''') - C (O)
_{- (CH 2) w H (} v equals 2, 3 or 4, w is equal to 1, 2, 3, etc.), (R '''' represents H or an alkyl group), corresponding acylsulfonamide Group; T and T ′ are each independently 5-phenyl, 5-Cl, 5-OCH ₃ or 5
It is a type that represents --CH ₃ .

Another group of preferred spectral sensitizers suitable for use with the emulsion crystals according to the invention is:
R '''is hydrogen, Z is a nitrogen atom, and T is 5-
Phenyl, 5-Cl, 5-OCH ₃ or 5-CH ₃ , T ′ is 5,6- (Cl) ₂ , 5-CN-6-C
_{l, 5-CF 3 -6-} Cl, 5-Cl; 5-CN, 5-
_{CF 3, 5-CHF 2,} 5-SO 2 CH 3, 5-SO 2
R ″ ″ ″ ″ (R ″ ″ ″ represents a fluorine-substituted or non-fluorine-substituted alkyl group); 5-COOR ″ ″ ″ ″ ″
And ^{_{5-SO 2 -N (R x}} ) (R y) or 5-CO-N
(R ^x ) (R ^y ), R ^x and R ^y each independently represent a substituted or unsubstituted alkyl group, or each independently or together with the N atom to which they are bonded, may form a ring. There are different types.

Particularly preferred structures of the type in which Z represents oxygen are T and T'each representing Cl, or T is C.
It represents l, T 'is or vice versa represents phenyl, R and R' in each independently of formula - (equal to n is 2, 3 or ^{_{4), - - (CH 2}} ) n SO 3 ( CH ₂ ) ₂ —CH (CH ₃ ) —SO ₃ ^— and —CH ₂ —CHY—CH ₂ —SO ₃ ^— (Y is —OH or —
It represents one combination of represent Cl); R represents one of the formulas, R 'is _{- (CH 2) p H (} p equals 1, 2, 3 or 4), -CH ₂ - _{^{Phen-SO 3 - -CH 2 -Phen}} -COOH - (CH 2) q -Phen-COOH (q equals 1, 2 or 3) is equivalent to one.

Examples of useful spectral sensitizers according to the general formula above are anhydro-5,5'-dichloro-3,3 '.
-Bis (n-sulfobutyl) -9-ethyloxacarbo-cyanine hydroxide or anhydro-5
There is 5'-dichloro-3,3'-bis (n-sulfopropyl) -9-ethyloxacarbo-cyanine hydroxide.

Suitable mixtures of spectral sensitizers that can be used include anhydro-5,5'-dichloro-3,3'-bis (n-sulfobutyl) -9-ethyloxacarbo-cyanine hydroxide or anhydro-5. , 5'-
Dichloro-3,3'-bis (n-sulfopropyl) -9
There are -ethyloxacarbo-cyanine hydroxide and anhydro-5,5'-dicyano-1,1'-diethyl-3,3'-di (2-acetoxyethyl) ethyl-imidacarbocyanine bromide.

Other dyes, which themselves do not have any spectral sensitizing activity, or certain other compounds which do not substantially absorb visible radiation, are supersensitized when incorporated together with said spectral sensitizers in the emulsion. Can have an effect. Suitable supersensitizers include heterocyclic mercapto compounds containing at least one electron-negative substituent such as those described in US-P 3457078, eg US-P 2933.
390 and nitrogen-containing heterocyclic ring-substituted aminostilbene compounds as described in US Pat. No. 3,635,721, US-
There are aromatic organic acid / formaldenide condensation products, cadmium salts, and azeindene compounds as described in P3743510.

The silica to silver halide ratio is determined at the stage of precipitation and / or by further addition of silica at or after the redispersion stage. Hydrogen cross-linking polymers such as gelatin can be added. When added, the ratio of hydrogen cross-linking polymer to silver halide, expressed as silver nitrate, is comprised between 0.05 and 0.40, more preferably between 0.15 and 0.30, It is preferred to add hydrogen cross-linking polymers to the emulsion to make an emulsion containing silver halide tabular grains having silica as a protective colloid for coating. The preferred ratio of silica to silver halide, otherwise designated as silver nitrate, is 0.
It is contained in the range of 03-0.3, and more preferably 0.05-0.
Included between 15.

A compound for preventing fog formation or a compound for stabilizing photographic characteristics is added to an emulsion containing silver halide tabular grains prepared according to the present invention, before, during or after its chemical ripening, or photographed. It can be added during manufacture or storage of the material or during processing of the photographic material. Mixtures of two or more of these compounds can be used.

Many known compounds can be added to the silver halide emulsion as antifoggants or stabilizers. Suitable examples include, for example, heterocyclic nitrogen-containing compounds such as benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles, mercaptothiadiazoles, aminos. Triazole, benzotriazole (preferably 5-methyl-benzotriazole), nitrobenzotriazole, mercaptotetrazole, especially 1-phenyl-5-mercaptotetrazole, mercaptopyrimidine, mercaptotriazine, tetrazaindene and pentazaindene, especially Z. Wiss. .
Photo. 47 (1952), published by Birr on pages 2-58, GB-A1203757, GB-.
A1209146, JP-Appl. 75-39537 and triazolopyrimidines such as those described in GB-A1500278, and 7-hydroxy-s-triazolo- [1,5- as described in US-P 4727017.
a] -pyrimidine, and other compounds such as benzenethiosulfonic acid, benzenethiosulfinic acid, benzenethiosulfonic acid amide. Other compounds that can be used as antifoggants include Research Disclosure No. 1
7643 (1978) There are compounds described in Chapter VI.

The silver halide emulsions made in accordance with the present invention form one or more silver halide emulsion layers coated on a support to form photographic silver halide materials by well known methods. Can be used for

Two or more emulsions containing separately prepared silver halide tabular grains according to this invention can be mixed in at least one emulsion layer to form a photographic emulsion for use according to this invention. it can.

The photographic materials of this invention can contain various surfactants in the photographic emulsion layer or in at least one other hydrophilic colloid layer. Suitable surfactants include saponins, alkylene oxides such as polyethylene glycol, polyethylene glycol / polypropylene glycol condensation products, polyethylene glycol alkyl ethers or polyethylene glycol alkylaryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycol alkylamines. Or nonionic surfactants such as alkylamides, silicone-polyethylene oxide adducts, glycidol derivatives, fatty acid esters of polyhydric alcohols and alkyl esters of saccharides; containing acid groups such as carboxy, sulfo, phospho, sulfuric acid or phosphoric acid ester groups Anionic surface active agents; amino acids, aminoalkyl sulfonic acids, amino acids Amphoteric surfactants such as kylsulfates or phosphates, alkylbetaines and amine-N-oxides; and alkylamine salts, aliphatic, aromatic or heterocyclic quaternary ammonium salts, aliphatic or heterocyclic containing phosphoniums or sulfoniums. Contains cationic surfactants such as salts. Such surfactants are used for various purposes, for example, as coating aids, antistatic compounds, compounds that improve lubricity, compounds that facilitate dispersion emulsification, compounds that prevent or reduce adhesion, and It can be used as a compound to improve photographic properties such as high contrast, sensitization and development acceleration.

Development acceleration is promoted by various compounds such as US-
P3038805, US-P4038075, US-P
4292400 and EP application filed 12 July 1993, application 9320202059 and E filed 11 March 1994.
This can be achieved with the aid of polyalkylene derivatives having a molecular weight of at least 400, such as those described in P-application 94260039.

The photographic material of the present invention may further contain various other additives such as a compound which improves the dimensional stability of the photographic material, a UV absorber, a spacing agent, a hardening agent and a plasticizer as shown below.

According to the invention, the support and, above it,
A silver halide tabular crystal having silica as a protective colloid having at least one hydrophilic colloid layer containing at least one photosensitive silver halide emulsion layer characterized in that the photosensitive layer contains at least one of the above emulsions. A light-sensitive photographic material coated from an emulsion containing is provided.

Layers of photographic material, especially when the binder used therein is gelatin, which can be hardened with a suitable hardener, for example those of the epoxide type, those of the ethyleneimine type, those of the vinyl sulfone type. For example 1,3-vinyl-sulfonyl-2-propanol, bis- (vinyl-sulfonyl) -methane, chromium salts such as chromium acetate and chromium alum, aldenides such as formaldehyde,
Glyoxal and glutaraldehyde, N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin, dioxane derivatives such as 2,3-dihydroxy-dioxane, active vinyl compounds such as 1,
3,5-triacryloyl-hexahydro-s-triazine, active halogen compounds such as 2,4-dichloro-6
It can be cured with -hydroxy-s-triazine and mucohalogen acids such as mucochloric acid and mucobromic acid. These curing agents can be used alone or in combination. The binders can also be hardened with fast-reacting hardeners such as carbamoylpyridinium salts as described in US Pat. No. 4,063,952 and with onium compounds as described in EP-A408143.

The emulsions are preferably coated on any suitable substrate such as a thermoplastic, eg polyethylene terephthalate or polyethylene coated paper support.

Additives suitable for improving the dimensional stability of the photographic material, such as water-soluble or poorly soluble synthetic polymers, such as alkyl (meth) acrylates, alkoxy (meth) acrylates, glycidyl (meth) acrylates, (meth ) Polymers of acrylamide, vinyl ester, acrylonitrile, olefins and styrene, or those mentioned above with acrylic acid, methacrylic acid, α, β-unsaturated dicarboxylic acids, hydroxyalkyl (meth) acrylates, sulfoalkyl (meth) acrylates, and A dispersion of a copolymer of styrene sulfonic acid can be added.

Suitable plasticizers for incorporation in the emulsions according to the invention include, for example, glycol, glycerin, or polyvinyl acetate, lower alkanol acrylates and methacrylates, such as polyethyl acrylate and polybutyl methacrylate. There is a polymer latex.

Suitable UV absorbers include, for example, US-P3
Aryl substituted benzotriazoles as described in 533794, US-P3314794 and US-P33.
4-thiazolidone compounds as described in 52681,
Benzophenone compounds as described in JP-A 2784/71, US-P 3705805 and US-P 370.
Cinnamic acid ester compounds as described in 7375, U
There are butadiene compounds such as those described in S-P 4045229 and benzoxazole compounds such as those described in US Pat.

Generally, the spacing agent has an average particle size of 0.2.
It is included between μm and 10 μm. Spacing agents can be soluble or insoluble in alkali. The alkali-insoluble spacing agent usually remains permanently in the photographic material, while the alkali-soluble spacing agent is usually removed therefrom in the alkaline processing bath. Suitable spacing agents can be made, for example, from polymethylmethacrylate and hydroxypropylmethylcellulose hexahydrophthalate. Other suitable spacing agents are US-
P4614708.

The silver halide tabular crystals prepared according to the invention when embedded in a photographic material are surrounded by colloidal silica which acts as a very useful protective colloid. A particularly advantageous cure resulting therefrom is the good resistance of the coated material to the phenomenon of pressure. Emulsion layers according to the present invention, especially thin emulsion layers, show significant improvements in both resistance to stress and rapid processability compared to conventional emulsions made in gelatin-containing media. A stronger pressure mark can be expected when the weight ratio of gelatin to silver halide is reduced. Nevertheless, as a result of the protective action of the silica adsorbed on the silver halide crystal surface,
For example, JP-A 05053230 and 05088285.
There is a very small pressure sensitivity that cannot be expected to the same degree as when silica is added as a coating additive as described in (1).

Photographic silica tabular silver halide emulsions are various photographic materials such as graphic arts, diffusion transfer reversal photographic materials, low speed and high speed photographic materials, X-ray materials and micrograph materials for so-called amateur and professional photography. Can be used in photographic materials for etc.

In a preferred example, photographic silver halide emulsions are used in X-ray materials. In radiographs, the material having a single or double emulsion layer coated on one or both sides of the support can contain a silver halide emulsion according to the invention.
By using double emulsions that differ in photographic speed by at least 0.15 log E, advantages can be gained in crossover exposure in double-sided coated materials.

The photographic material comprises several non-photosensitive layers, such as a protective antistress layer, one or more backing layers, and eventually a filter or antihalation which absorbs scattered light and thus promotes image sharpness. It may contain one or more intermediate layers containing dyes. Suitable light-absorbing dyes for use in these interlayers are, for example, US-P4092168, US-P43.
11787, DE2453217 and GB790744
0 is described. Placing such an interlayer between the emulsion layer and the support results in only negligible loss in sensitivity, but under rapid processing conditions decolorization of the filter dye layer can cause problems. It is therefore advisable to reduce the overall coating layer packet thickness in the treatment cycle so as to give a short drying time after washing. Alternatively, the use of an intermediate layer placed between the emulsion layer and the support may provide the solution of reflecting the fluorescence emitted by the screen.

In color photography the material contains blue, green and red light sensitive layers, each of which can be single coated, but generally consist of double or even triple layers. In addition to the light-sensitive emulsion layer, the photographic material has several non-light-sensitive layers such as a protective anti-stress layer, one or more backing layers, one or more subbing layers,
It may contain one or more intermediate layers such as a filter layer and an after layer containing for example a curing agent, an antistatic agent, a filter dye for safe light purposes.

One or more backing layers can be provided on only one side of the support, on the non-photosensitive side of the support of at least one emulsion coated material. These layers, which can act as anti-curl layers, can contain matting agents such as silica particles, lubricants, antistatic agents, light-absorbing dyes, opacifying agents such as titanium dioxide and the usual ingredients such as hardeners and wetting agents.

The support of the photographic material can be opaque or transparent and can be, for example, a paper support or a resin support. When a paper support is used, it is preferably coated on one or both sides with an α-olefin polymer, eg a polyethylene layer, optionally containing antihalation dyes or pigments. Also, organic resin supports such as cellulose nitrate film, cellulose acetate film, poly (vinyl acetal) film, polystyrene film, poly (ethylene terephthalate) film, polycarbonate film, polyvinyl chloride film, or poly-α-olefin film such as polyethylene or Polypropylene film can also be used. The thickness of the organic resin film is preferably 0.07 to 0.35 mm. These organic resin supports are preferably coated with a subbing layer which can contain water-insoluble particles such as silica or titanium dioxide.

The photographic materials containing tabular grains prepared according to this invention can be image-wise exposed with any convenient radiation source in accordance with its particular application.

Of course processing conditions and processing solutions will depend on the particular type of photographic material in which the tabular grains prepared according to this invention are applied. For example, in a preferred example of a material for X-ray diagnostic purposes, the material is applicable to rapid processing conditions including developing, fixing, washing and drying steps. Preferably an automatically operated processor equipped with a device for automatic regeneration of the processing solution is used. Depending on the processing application that determines the degree of cure required in the processing cycle, pre-cured materials can be processed using partially packaged or three part packaged chemicals. Within the scope of the invention, a total processing time of less than 30 seconds is possible, whereas in the usual practice it is known to use up to 90 seconds. From an environmental point of view it is possible to use sodium thiosulfate instead of ammonium thiosulfate and even reduce the regeneration of developer and fixer.

The reduced pressure sensitivity to coated materials from silver halide emulsions according to the present invention should be observed as an exceptional advantage obtained by the various processing conditions and provided by said tabular silver halide emulsion crystals. .

The following examples illustrate the invention but are not limited thereto. Percentages are weight percentages unless otherwise stated.

[0104]

【Example】

Example 1 Emulsion A (silver bromoiodide tabular grains)

The following solutions were made: (1) 3 l of dispersion medium (C) containing 0.3 mol of potassium bromide was made at 70 ° C. and the pH was adjusted to 4.5; (2) 2. 94 mol of silver nitrate solution (A); (3) solution containing 1.47 mol of potassium bromide (B1); (4) 1.43 mol of potassium bromide and 0.04 mo
A solution containing 1 liter of potassium iodide (B2).

Prior to the start of precipitation, the initial UAg measured against the silver / silver chloride reference electrode was adjusted to -34 mV.

The nucleation step was carried out by introducing the solution A and the solution B1 into the dispersion medium C at the same time for 30 seconds at a flow rate of 20 ml / min. After a physical aging time of 15 minutes, 15% silica sol "Kieselsol 500" (trademark product of Bayer AG) 5
00 ml and costabilized phosphonium compound (Phen) ₃ −
P ⁺ -CH ₂ -CH ₂ OH. 51.6 ml of a 5% solution of Cl ⁻ (Phen represents a phenyl group) was added. pH
The value was adjusted to a value of 3.0 and the solution was stirred for a further 5 minutes.

The growth step started with solution A at a flow rate of 2.5 ml / min and increased linearly to a final value of 12.4 ml / min and solution B1 was added to a saturated calomel electrode (S.
C. E. FIG. ) Was measured with a silver electrode and introduced with a double jet for 65 minutes and 36 seconds at an increasing flow rate to maintain a constant mV value of -50 mV.

After cooling the vessel to about 40 ° C., dialysis was performed to obtain a desalted solution having a conductivity of 10 mS or less. The resulting solution was designated as A1. Other emulsions A2-A5
To produce Kieselsol 500 (ml in SILI
(Expressed as CA), mol% of silver present in the nucleation step (AGNUC), KSCN in reaction solution C and solution B2 (ml of 2% solution) and pAg value in the growth step. In addition, these corresponding data are shown in Table 1.

The thus-obtained silver bromoiodide tabular emulsion having 2 mol% iodide ion exhibited the following characteristics.

[0111]

The average diameter d _EM , the average thickness d and the average aspect ratio AR were obtained from the electron micrographs: the diameter of the grains was of a circle with an area equal to the projected area of the grains as seen in the photograph. Defined as diameter. Further, the average equivalent spherical diameter d _M was calculated from the values of d _EM and d by the following formula.

D _M = (3/2 × d _EM ² × d) ^1/3

The average diameter d _V is 100 using the macro electrode.
It was calculated stochastically after measurement of the individual currents generated by the reduction of zero separated silver bromoiodide crystals. Since the current is a representative value of the volume of crystals, it was calculated from the volume of a globe having the same volume as the tabular grains. The standard deviation was calculated stochastically from these data, and the value of the coefficient of variation VAR which defines the quotient of the standard deviation and the average diameter is shown in the table.

Further counted tabular grain percentage quantities are shown in Table 2 along with other data.

[0116]

In Table 1, the high percentage by number of tabular grains having aspect ratios greater than 5 (at least 9
It can be concluded for the emulsion that 0%) was calculated from the corresponding electron micrographs. It was possible to detect that very thin crystals with even higher aspect ratios were obtained.

During redispersion of the emulsion, an amount of inert gelatin was added such that the weight ratio of gelatin to silver halide (expressed as silver nitrate) was 0.25. The emulsion had an odor equivalent to 190 g of silver nitrate per Kg. It contained an amount of silver iodide.

The emulsion was chemically ripened with sulfur and gold for 4 hours at 47 ° C. to obtain the best relationship between fog and speed,
It was stabilized with 4-hydroxy-6-methyl-1,3,3a-tetrazaindene before coating on one side of a 175 μm thick polyester support. Therefore, silver bromoiodide 1m
For ol, the optimum amount of toluenethiosulphonic acid was used as a weak oxidative pre-ripener before chemical ripening, followed by 362.5 mg of anhydro-5,5'-dichloro-.
Addition of 3,3'-bis (n-sulfobutyl) -9-ethyloxacarbo-cyanine hydroxide.
Another 200 mg of 1-p-carboxyphenyl-5-mercaptotetrazole was added.

The emulsion layer was overcoated with a protective layer. The amount of emulsion solution was in all cases the same not only in the emulsion layer but also in the protective layer. The following components were added per mol of silver halide before coating:

4-hydroxy-6-methyl-1,3,3a, 7-tetraazaindene 785 mg as an antifoggant and stabilizer, phloroglucin 39 mg as a curing accelerator, resorcin 2.68 g as a curing agent, coating Deionized water was added to reach a concentration corresponding to about 200 g of silver nitrate per liter of solution.

A protective coating composition was made containing the following components in 1 l of deionized water:

(1) 35.4 g of inactive gelatin, (2)
37 g silica sol of silica particles having an average diameter of 7-10 nm, (3) 20 g of an aqueous dispersion of a matting agent containing 10% gelatin and 3.2% polymethylmethacrylate and having an average particle diameter of 2 μm, (4) 225 mg of chromium acetate as a curing agent, (5) N-polyoxyethylene-N-ethyl-perfluoro- as a surfactant
Octane-sulfonamide (FC170C, 3M brand name product) 750 mg and ammonium perfluoro-octanoate (FC143, 3M brand name product) 300
mg, (6) 1500 mg of phenol as a preservative,
(7) Mobilcer Q10 from MOBIL OIL as a lubricant
00 mg, (8) formaldehyde was added as a curing agent.

As a comparative emulsion, a tabular silver bromoiodide emulsion was prepared in a gelatin-containing medium according to the process described in Emulsion 2 of Example 1 of EP569075.

As a result, the difference between the silver halide crystal coverage expressed as silver nitrate equivalent and the gelatin coverage in the emulsion layer was 3.6 g of silver nitrate relative to the comparative example.
/ M ² and gelatin for silica emulsion 1.8 respectively
0 and 0.90 g / m was ^2, thus about 0.4, respectively the ratio of gelatin to silver nitrate for both emulsions (the comparative Example) and 0.3 (relative to the embodiment corresponding to the invention) Met. After coating the protective antistress layer, the total amount of gelatin coated is 3.10 and 2.20 g / m ^2, respectively.
Met.

Due to the high amount of hardener, said hardener should be added to the coating composition of the protective topcoat layer immediately before coating so that it has a comparative water absorption.

The opposite side was coated with a conventional antihalation backing layer.

After coating and drying, the coated material was exposed to 540 nm green light for 0.1 seconds using a continuous optical wedge,
Processor CUR with the following time (seconds) and temperature (° C) characteristics
Treated in IXHT530 (trademark of Agfa-Gavaert) between 38 second treatment cycles:

Insertion: 0.2 seconds Development: 9.3 seconds (at 35 ° C. in the developing solution shown below) Crossover: 1.4 seconds Washing: 0.9 seconds Crossover: 15 seconds Fixing: 6.6 seconds (35 ° C in the fixer shown below) Crossover: 2.0 seconds Washing: 4.4 seconds (20 ° C) Crossover: 4.6 seconds Drying: 6.7 seconds Total: 37.6 seconds

Composition of developer: concentrated part: water 200 ml potassium bromide 12 g potassium sulfite (65% solution) 249 g ethylenediaminetetraacetic acid sodium salt trihydrate 9.6 g hydroquinone 106 g 5-methylbenzotriazole 0.076 g 1-phenyl -5-Mercaptotetrazole 0.040 g Sodium tetraborate (10 hydrate) 70 g Potassium carbonate 38 g Potassium hydroxide 49 g Diethylene glycol 111 g Potassium iodide 0.022 g 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidinone 3 g Water To 1 liter.

The pH was 11.1 at 25 ° C. with potassium hydroxide.
Adjusted to 5. To start the process, 1 part of the concentrated developer was mixed with 3 parts of water. No initiator was added. The pH of this mixture was 10.30 at 25 ° C.

Composition of fixer: Concentrated part: Ammonium thiosulfate (78% solution) 661 g Sodium sulfite 54 g Boric acid 25 g Sodium acetate trihydrate 70 g Acetic acid 40 g Make up to 1 liter with water.

The pH was adjusted to 5.30 with acetic acid at 25 ° C.

To make this fixer ready for use, 1 part of this concentrated portion was mixed with 4 parts of water. 5.25 at 25 ° C
PH was measured.

Table 3 shows the sensitometric data after processing and the numerical value (A for the developed amount of silver for 1 m ^2).
GDEV), percentage developed silver (% DEV), covering power (CP) and qualitative evaluation (PM) of pressure marks.

The sensitivity (S) was measured at the density of the support and the density of 1 on the fog, and the gradation (G) was measured between the density of the support and the density on the fog of 2.4 and 1.8. .

When the amount of light required to reach a support density and a density of 1.00 above fogging is lower for the more photosensitive material, the sensitivity is greater for lower values. 100 times l
Shown in Table 2 as ogE, this is a measure of the material having a sensitivity that doubles in height for every drop in value of 30.

F (fog), S (sensitivity) and G (gradation)
The value of is shown by multiplying F by 1000 and S and G by 100 respectively.

The pressure marks PM are produced before processing and therefore in the dry state, for example during production, especially during the production process. The sensitivity of materials to this type of pressure is determined by pressure testing (EP
-See also A528476), in which the pressure applies different small gears on the exposed material, each of them having a different weight and obtained after processing in a hand processor. Leave the separately marked rails on the wedge (to avoid pressure sensitive marks caused by roller contact as described above).

The numbers 6 to 1 are indicators for materials evaluated as very bad to very good for this type of pressure mark.

From Table 3 it can be seen that emulsions containing tabular grains of silver bromoiodide precipitated in silica sol in the presence of onium compounds have the same crystal size but silver bromoiodide precipitated in gelatin. It can be concluded that it is excellent for emulsions (see Emulsion COMP, which is free of silica in the coating). In particular, the coverage of emulsions A1, A3 and A5 is remarkable in terms of fog-sensitivity relationship and pressure marks.

[0142]

Example 2 Emulsion B (Silver Bromoiodide Tabular Grain) Emulsion B was a co-stabilized phosphonium compound (Phen) ₃ -P.
⁺ -CH ₂ -CH ₂ OH. Cl ^- 5% solution 51.6m
with 15% silica sol Kies instead of 500 ml
250 ml of elsol 500 (trademark product of Bayer AG)
Was prepared in the same manner as Emulsion A except that was added after 15 minutes of physical ripening time.

The preparation and coating procedure for coating on Emulsion B1 is exactly the same as in Example 1, together with a comparative emulsion made in a gelatin-containing medium according to the preparation method described in Emulsion 2 of Example 1 of EP 569075. Went to.
Exposure, processing and sensitometric evaluation of the coated sample were the same as in Example 1. The results are shown in Table 4.

From Table 4, it can be concluded that even with a small amount of silica sol, the pressure sensitivity is remarkably reduced for an emulsion containing silver bromoiodide tabular grains precipitated in a silica sol in the presence of an onium compound. Effective protection of crystals by colloidal silica used as protective colloid is a crucial factor.

[0146]

Example 3 Emulsion C (Silver Bromoiodide Tabular Grain) Emulsion C is a co-stabilized phosphonium compound (Phen) ₃ -P.
⁺ -CH ₂ -CH ₂ OH. Cl ^- 5% solution 51.6m
with 15% silica sol Kies instead of 500 ml
150 ml of elsol 500 (trademark product of Bayer AG)
Was prepared in the same manner as Emulsion A except that was added during the nucleation step. The UAg value during growth was kept at -12 mV.

The preparation and coating procedure for coating on Emulsion C together with a comparative emulsion made in a gelatin-containing medium according to the preparation method described in Emulsion 2 of Example 1 of EP 569075 is exactly the same as in Example 1. Went to.

Exposure, processing and sensitometric evaluation of the coated sample were the same as in Example 1. The results are shown in Table 5.

[0150]

From Table 5, it can be seen that for emulsions containing silver bromoiodide tabular grains precipitated in a silica sol in the presence of an onium compound during the nucleation step, even if the amount of silica sol was small (silica to silver weight ratio). 0.1), it can be concluded that the desired sensitometry can be reached.

It is clear that higher sensitivity produces worse pressure marks. However, for the higher light sensitive emulsions, it is clear that the grains precipitated in silica have better pressure marks than for the less sensitive comparative emulsions made in gelatin containing media. Further, the gradation of silica emulsion is high although the fog level is high.

Example 4 Emulsion D (Silver Bromoiodide Tabular Grains) Emulsion D during nucleation was prepared by changing the amount of co-stabilized phosphonium compound (Phen) ₃ -P ⁺ -CH ₂ -CH ₂ O to 51.6 ml.
H. Cl ^- with 5% solution 103.2ml of, 500 meters
15% silica sol instead of 1 Kieselsol 500 (Ba
250 ml (trademark product of yer AG) was made in the same manner as Emulsion A except that it was added after 15 minutes of physical life. The UAg value during growth was kept at a value of +8 mV.

The preparation and coating procedure for coating for Emulsion D, together with a comparative emulsion made in a gelatin-containing medium according to the procedure described in Emulsion 2 of Example 1 of EP569075, is exactly the same as in Example 1. Went to the same.

Exposure, processing and sensitometric evaluation of the coated sample were the same as in Example 1. The results are shown in Table 6.

[0150]

From Table 6 it is seen that for emulsions containing silver bromoiodide tabular grains precipitated in a silica sol in the presence of an onium compound, even though the amount of silica sol was low (silica to silver weight ratio 0.15). It can be concluded that the desired sensitometry can be reached if the amount of onium compound added to the reaction vessel is increased to ensure sufficient protection of the colloidal stability of the silver halide crystals. The pressure mark is remarkable although the fogging level is high.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G03C 5/26

Claims (16)

[Claims] 1. A tabular grain containing a colloidal silica sol as a protective colloid, wherein the tabular grain has a particle size of 0.1.
A light-sensitive silver halide emulsion having an average grain thickness of 3 µm or less, an average aspect ratio of more than 12: 1, and a coverage of 50 to 2000% by silica sol grains. 2. The photosensitive silver halide emulsion according to claim 1, wherein the coverage of the tabular grains with silica sol grains is in the range of 75 to 500%. 3. A tabular grain having a coverage strength of 0.2 μm.
2. The photosensitive silver halide emulsion according to claim 1, which is less than or equal to m. 4. The total projected area of tabular grains is at least 7.
4. The photosensitive silver halide emulsion according to claim 1, wherein the content is 0%. 5. The total projected area of tabular grains is at least 9.
The photosensitive silver halide emulsion according to any one of claims 1 to 4, which is 0%. 6. A light-sensitive silver halide photographic material having at least one hydrophilic colloid layer containing at least one light-sensitive layer on at least one side of a support, said light-sensitive layer comprising: 5. A light-sensitive silver halide photographic material coated with at least one silver halide emulsion according to any one of items 1 to 5 above. 7. The following steps: (a) 0.003 μm in the presence of an onium compound except for the ammonium compound, but in the absence of gelatin.
By the double-jet or triple-jet method applied to an aqueous solution of silver nitrate and a halide salt in colloidal silica having an average particle size in the range of m to 0.3 μm, the weight ratio of the colloidal silica to the onium compound is 3 to. Precipitating the silver halide between 400 (b) controlling the nucleation and growth steps by varying the flow rate of the aqueous solution of silver nitrate and halide salt and / or by a constant pAg value during the step in the vessel Process, (c)
The equivalent of silver nitrate is always at least 0.03 throughout the steps of desalting from the reaction medium and redispersing the silver halide, (d) chemically ripening the silver halide, and (e) precipitating. 7. The method for producing a photosensitive silver halide emulsion according to claim 1, further comprising the step of adjusting the weight ratio of the colloidal silica sol to the amount of silver halide indicated as. 8. The method of claim 7, wherein the weight ratio of said colloidal silica and said onium compound is between 30 and 100. 9. The method according to claim 7, wherein a denaturant is present in the reaction vessel in the nucleation and / or growth step. 10. The method according to claim 7, wherein the emulsion is desalted by ultrafiltration. 11. The chemical ripening is carried out before, during or after spectral sensitization, according to any one of claims 7 to 10.
Method of terms. 12. A ratio of hydrogen bridge forming polymer to silver halide expressed as silver nitrate is comprised between 0.05 and 0.40 and a ratio of silica to silver halide expressed as silver nitrate is 0.03 to. A hydrogen cross-linking polymer and silica are added to the emulsion in an amount such that it is comprised between 0.30 to make the emulsion for coating.
11. The method according to any one of 11 above. 13. The method of claim 12 wherein said ratio of silica to silver halide, expressed as silver nitrate, is comprised between 0.05 and 0.15. 14. The method of claim 12 wherein said ratio of silica to silver halide expressed as equivalent of silver nitrate has a value of 0.02 to 1.0. 15. Coating by adding a polymer which forms hydrogen bridges in an amount such that the weight ratio of polymer to coated silver, expressed as the equivalent of silver nitrate, has a value between 0.15 and 0.30. 15. A method according to any one of claims 12-14, characterized in that an emulsion for is prepared. 16. The steps of developing, fixing, washing and drying are performed in 5 steps.
The method of processing a photographic material according to claim 7, wherein the processing time is within the total processing time of less than 0 seconds.