DE3782351T2 - LIGHT SENSITIVE PHOTOGRAPHIC SILVER HALOGENID MATERIAL USED FOR FAST DEVELOPMENT. - Google Patents

Description

This invention relates to a silver halide photographic light-sensitive material suitable for rapid processing, particularly to a silver halide photographic light-sensitive material having high sensitivity and excellent printing resistance and grain even in ultra-rapid processing.

In recent years, light-sensitive silver halide photographic materials have been consumed in ever-increasing quantities. For this reason, the number of sheets required for processing light-sensitive silver halide photographic materials has also increased, and there has been a desire for faster processing, i.e. an increase in the amount processed within a certain time.

The above development can also be observed in the field of photosensitive X-ray recording materials, such as X-ray films for medical purposes. More precisely, with an ever-increasing frequency of diagnoses due to the encouragement of regular health check-ups, more precise diagnoses are desired, which increases the number of persons to be examined and the number of sheets used for X-ray photography.

On the other hand, it is necessary to obtain the diagnostic result as quickly as possible.

Consequently, there is a great need for faster treatment than before to facilitate diagnosis. In particular, for example, in the case of angiography or In perioperative photography it is necessary to obtain photographs for viewing as quickly as possible.

In order to meet the above requirements in the medical field, it is necessary to promote the automation (e.g. of photography or transport) of diagnosis and also to process X-ray films more quickly.

However, the ultra-rapid processing involves problems such as (a) the density is insufficient (i.e., there is a decrease in sensitivity, contrast and maximum density), (b) the fixing cannot be carried out sufficiently, (c) the washing of the film with water and (d) the drying of the film may be insufficient. Insufficient fixing and washing of the film with water may result in a change in the color of the film during storage and consequently in a reduced image quality.

One way to solve these problems is to reduce the amount of gelatin. However, reducing the amount of gelatin is likely to cause problems such as unevenness and streaking in the coating. In addition, when films with less gelatin rub against each other or are rubbed by other materials, a so-called abrasion blackening can occur after treatment, creating an area with a higher density than other areas.

As mentioned above, there is a desire for ultra-fast processing. In the present specification, ultra-fast processing is a processing for a total duration of 20 to 60 seconds during which the top end of a film is first introduced into an automatic processing device, then passed through a developing tank, over a conveyor line, through a fixing tank, over a conveying path, through a washing tank, over a conveying path and through a drying section and finally discharged from the drying section [in other words, the quotient (s) obtained by dividing the total length (m) of a treatment feed line by the conveying speed (m/s) of the apparatus]. The reason why the time required for the conveying paths is taken into account is that, as is well known in the present industry, a treating solution used in a previous step may also swell on a conveying path and the treating step is considered to take place largely on the conveying path.

In order to promote rapid processing, it is extremely important to control the surface tension and viscosity of coating solutions used to form an outermost layer and a layer adjacent to the outermost layer which constitute a silver halide photographic light-sensitive material. In particular, a bead coating method for improving the viscosity of a coating solution is described in Japanese Unexamined Patent Publication No. 115214/1977, No. 1350/1979 and No. 108566/1981. Many attempts have been made to provide better photographic layers. For example, in the lowermost layer of a light-sensitive material, the amount of the coating solution and the viscosity are 2 to 12 g/m² and 1 to 8 cp, respectively (Japanese Unexamined Patent Publication No. 115214/1977), or the ratio between the viscosity n₀ of a coating solution for a lowermost layer and the viscosity n₁ of a coating solution for a lowermost layer is 0 to 10 g/m². of a coating solution for a layer directly above the bottom layer is such that n₀ = n₁ ± 10 (cp) when the bottom layer is coated at a low shear rate and n₀ < n₁ when the bottom layer is coated at a high shear rate coated (Japanese Unexamined Patent Publication No. 108566/1981).

Japanese Patent Publication No. 47045/1976 describes the importance of the amount of gelatin in rapid processing, but the total processing time including the time for the transport routes is 60 to 120 seconds. However, such a processing time cannot meet the requirements of ultra-rapid processing as it is carried out today.

In addition, in recent years, especially with the increase in medical X-ray examinations, there has been a clear demand from international public opinion to reduce the radiation dose in the field of medicine. To meet such a demand, fluorescent intensifying paper, intensifying screens, fluorescent screens and X-ray image intensifiers have been used. There has been a remarkable improvement in these and an increase in the sensitivity of photosensitive X-ray photographic recording materials. On the other hand, in order to carry out examinations more precisely, there is a need for high-precision X-ray photography. Since the precision increases proportionally with stronger X-rays, an X-ray photography method with a higher radiation dose and a large-volume X-ray generator have been developed. However, the photography techniques requiring such a high radiation dose contradict the above-mentioned demand for reduced radiation doses and cannot be described as preferable. Accordingly, in the field of X-ray photography, lower radiation and higher precision are desired. Consequently, a photographic recording material is sought that can produce precise images, i.e. that has a higher sensitivity with a reduced radiation dose.

There are various techniques available for increasing the sensitivity, i.e., sensitization methods, with the same grain size. Accordingly, it is expected that the sensitivity can be increased while maintaining the same grain size, namely, while maintaining the covering power, if an appropriate sensitization method is used. There are numerous reports of such methods, including, for example, a method in which a development accelerator such as a thioether is added to an emulsion, a method in which a spectrally sensitized silver halide emulsion is subjected to hypersensitization by means of an appropriate combination of dyes, or a method using optical sensitizers. However, these methods do not necessarily have suitable properties for use in high-sensitivity silver halide light-sensitive photographic materials. In other words, the highly sensitive silver halide light-sensitive photographic materials chemically sensitized to the maximum extent tend to fog during storage when the above-mentioned processes are applied.

Furthermore, orthochromatic photosensitive recording materials, which have been made photosensitive by means of orthochromatic sensitization in the wavelength range of 540 to 550 nm, have been used in the field of medical X-ray photography rather than conventional recording materials, which conventionally have a photosensitive range of 450 nm. These recording materials have a wide photosensitive wavelength range and a higher sensitivity. Accordingly, they can reduce the X-ray radiation doses and minimize their influence on the human body. Thus, dye sensitization an extremely useful means of sensitization, but still presents unsolved problems. For example, there remains the problem that sufficient sensitivity cannot be achieved depending on the photographic emulsions used.

Pressure desensitization (i.e., desensitization at the time of development by mechanical pressure applied before exposure) may sometimes occur due to mechanical pressure applied before exposure. For example, in medical X-ray films of a large size, when a film is folded in an area where it is held due to its own weight, film folding such as the so-called crease may sometimes occur, thus causing pressure desensitization. Also, an automatic exposure and development device with mechanical conveyance is now widely used in medical photographic X-ray systems. However, in such a device, mechanical force may be applied to films, whereby the above-mentioned pressure blackening and pressure desensitization are likely to occur, especially in a dry place in winter. Such a phenomenon is likely to cause serious difficulties in medical diagnosis. In particular, it is known that silver halide photographic light-sensitive materials containing silver halide grains having a large grain size and high sensitivity are more likely to suffer from pressure desensitization.

Of the materials intended to improve the response to pressure desensitization, those using thallium or a dye are described in US Patents 2628167, 2759822, 3455235 and 2296204, French Patent 2296204 and Japanese Unexamined Patent Publications Nos. 107129/1976 and 116025/1975. The improvement However, the color staining is insufficient or color stains may occur to a large extent. Other materials cannot necessarily be said to have sufficiently provided a high-sensitivity silver halide photographic light-sensitive material comprising large-grain silver halide emulsions and primarily employing ordinary surface sensitivity.

On the other hand, various attempts have been made to reduce pressure desensitization by changing the binder properties of silver halide photographic light-sensitive materials, as described, for example, in U.S. Patent Nos. 3,536,491, 3,775,128, 3,003,878, 2,759,821 and 3,772,032 and Japanese Unexamined Patent Publication Nos. 3325/1987, 56227/1975, 147324/1975 and 141625/1976. Although an improvement in pressure desensitization has been achieved by these methods, no fundamental improvement has been achieved because sticking of the film surfaces or deterioration of the binder properties, e.g. B. Dryness and scratching, are possible to a serious extent.

The present invention is intended to provide a silver halide photographic light-sensitive material which can eliminate the above-mentioned problems even in rapid processing, e.g., ultra-rapid processing, the total processing time of which is 20 to 60 seconds as mentioned above, and has excellent sensitivity, contrast, maximum density, fixability and dryness.

The present invention also aims to provide a light-sensitive silver halide photographic material which, even with a reduced amount of gelatin, with fewer coating problems, suffers less abrasion blackening and pressure desensitization, and has excellent grain.

The present invention provides a silver halide light-sensitive photographic material comprising photographic layers coated under such conditions that the surface tension of a coating solution for forming an outermost layer is 6 10-3 N/m (6 dyn/cm) or more below the surface tension of a solution for forming the layer adjacent to the outermost layer, the photographic material satisfying at least one of the conditions:

(a) the amount of gelatin in all layers at least on the side of the support with a light-sensitive silver halide emulsion layer and a hydrophilic colloid layer is 2.20 to 3.10 g/m²,

b) the coating solution for forming the outermost layer and the solution for forming the layer adjacent to the outermost each have a viscosity of 20·10⁻³ Pas (20 cp) or less.

According to a preferred embodiment of this invention, the photographic recording material comprises at least one silver halide emulsion layer containing at least one compound of the formulas (I), (II) and (III):

Formula (I)

wherein R₁, R₂ and R₃, which may be the same or different, each represent a substituted or unsubstituted alkyl group, alkenyl group or aryl group, at least one of the groups R₁ and R₃ represents a sulfoalkyl group or carboxyalkyl group; X₁⊃min; represents an anion; Z₁ and Z₂, which may be the same or different, each represent a group of non-metallic atoms which, together with the carbon atoms to which it is attached, forms a substituted or unsubstituted carbon ring; n = 1 or 2, provided that n = 1 when an intramolecular salt is formed;

Formula (II):

wherein R₄ and R₅, which may be the same or different, each represent a substituted or unsubstituted alkyl group, alkenyl group or aryl group, at least one of R₄ and R₅ representing a sulfoalkyl group or a carboxyalkyl group; R₆ represents a hydrogen atom, a lower alkyl group or an aryl group; X₂⊃min; represents an anion; Z₁ and Z₂, which may be the same or different, each represent a group of non-metallic atoms which, together with the carbon atoms to which it is bonded, forms a substituted or unsubstituted carbon ring; n = 1 or 2, provided that n = 1 when an intramolecular salt is formed;

Formula (III):

wherein R₇ and R₉, which may be the same or different, each represent a substituted or unsubstituted lower alkyl group; R₈ and R₁₀, which may be the same or different, each represent a lower alkyl group, a hydroxyalkyl group, a sulfoalkyl group or a carboxyalkyl group; X₃⁻ represents an anion; Z₁ and Z₂, which may be the same or different, each represent a group of non-metallic atoms which, together with the carbon atoms to which it is attached, forms a substituted or unsubstituted carbon ring; n = 1 or 2, provided that n = 1 when an intramolecular salt is formed.

In this invention, the photographic layers were coated under conditions such that the surface tension of a solution for forming an outermost layer (usually the top layer) is 6 dynes/cm or more below the surface tension of a solution for forming the layer adjacent to the outermost layer (usually the layer immediately below the top layer). In order for the difference to be 6 dynes/cm or more, an embodiment must employ at least one surfactant in the outermost layer. The surfactant may or may not be employed in the layer immediately below the outermost layer. The surfactants employed in the outermost layer and the layer immediately below it may be the same or different.

The difference in surface tension between the solutions used for the outermost layer and the layer immediately below it is suitably not less than 8·10⁻³ N/m (8 dynes/cm), preferably not less than 10·10⁻³ N/m (10 dynes/cm) and ideally not less than 12·10⁻³ N/m (12 dynes/cm).

Usually, the "outermost layer" referred to in this invention actually means the outermost layer and generally represents the topmost layer referred to above. A coating prepared by spraying or coating, e.g. a supercoat, is sometimes provided on the outermost layer.

The surfactants suitable for this invention are e.g. B. non-ionic surfactants such as saponin (steroid type), alkylene oxide derivatives (e.g. polyethylene glycol, a polyethylene glycol/polypropylene glycol condensate, polyethylene glycol alkyl ethers or polyethylene glycol alkylaryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycol alkylamines or amides and addition products of silicones with polyethylene oxides), glycidol derivatives (e.g. alkenyl succinic acid polyglycerides and alkylphenol polyglycerides), aliphatic acid esters of polyhydric alcohols and alkyl esters of sugars and anionic surfactants having an acid group such as a carboxyl group, a sulfo group, a phospho group, a sulfuric acid ester group and a phosphoric acid ester group, including alkyl carboxylates, alkyl sulfonates, alkylbenzenesulfonates, Alkyl naphthalene sulfonates, alkyl sulfuric acid esters, alkyl phosphoric acid esters, N-acyl-N- alkyl taurines, sulfosuccinic acid esters, sulfoalkyl polyoxyethylene alkyl phenyl ethers and polyoxyethylene alkyl phosphoric acid esters as well as amphoteric surfactants such as amino acids, aminoalkyl sulfonic acids, aminoalkyl sulfuric acid or phosphoric acid esters, alkyl betaines and amine oxides as well as cationic surfactants such as alkylamine salts, aliphatic or aromatic quaternary ammonium salts, heterocyclic quaternary ammonium salts such as pyridinium and imidazolium, phosphonium or sulfonium salts with an aliphatic or a heterocyclic ring. In addition, fluorine-containing surfactants with or without a polyoxyethylene group can be used.

The alkylene oxide type surfactants are described, for example, in Japanese Patent Publication No. 9610/1976, DT-26 48 746 and Japanese Unexamined Patent Publication Nos. 129623/1978, 89624/1979, 98235/1979, 203435/1983, 208743/1983, 80848/1985 and 94126/1985. Examples of the combined use of the alkylene oxide type surfactants and other compounds are described, for example, in Japanese Patent Publication No. 9610/1976, DT-26 48 746 and Japanese Unexamined Patent Publication Nos. 129623/1978, 89624/1979, 98235/1979, 203435/1983, 208743/1983, 80848/1985 and 94126/1985. For example, Japanese Unexamined Patent Publications Nos. 89626/1979, 70837/1980, 11341/1982, 109947/1982, 74554/1984, 76741/1985, 76742/1985, 76743/1985, 80839/1985, 80846/1985, 80847/1985, 131293/1975 and 29715/1978.

The anionic surfactants may also include those described in Japanese Unexamined Patent Publication No. 21922/1978, GB-1503218 and Japanese Patent Publication No. 1617/1981, as well as higher alcohol sulfates, higher alkyl sulfonates, alkylbenzenesulfonates, dialkyl sulfosuccinates, acylmethyltauride, N-acyl sarcocinate, aliphatic monoglyceride sulfate and α-sulfonic acid.

The fluorine-containing surfactants may be those described in Japanese Patent Publication Nos. 9303/1972, 43130/1973, 25087/1977 and 1230/1982 and Japanese Unexamined Patent Publication Nos. 46733/1974, 16525/1975, 34233/1975, 32322/1976, 14224/1979, 111330/1979, 557762/1980, 19042/1981, 41093/1981, 34856/1981, 11341/1982, 29691/1982, 64228/1982, 146248/1982, 114944/1981, 114945/1981, 196544/1983, 200235/1983, 109548/1985 and 136534/1982, U.S. Patents 3,589,906, 3,775,126 and 4,292,402, RD-16630 and Japanese Unexamined Patent Publication No. 164738/1985.

The surface tension of the coating solutions controlled by the surfactant can be determined by measuring it according to the conventional Wilhelm's method at a given liquid temperature.

Preferred anionic surfactants without polyalkylene oxide group are:

Preferred fluorine-containing surfactants are:

Commercially available fluorine-containing surfactants are UNIDAIN (trademark) of Daikin Industries, Ltd. and FLOLARD (trademark) of 3M (Sumitomo 3M Limited).

Specific examples of polyoxyethylene type surfactants preferably used here are:

Preferred quaternary ammonium salts may include the compounds shown below as 4-1 through 4-20.

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The coating solutions used in the embodiment (b) of the invention for the outermost layer and the layer adjacent thereto, which constitute the photographic layer components of the light-sensitive material of this invention, are described below. The coating solutions preferably have a viscosity of 20·10⁻³ Pas (20 cp) or less, more preferably 15·10⁻³ (15 cp) or less. Further, the difference in viscosity between the two solutions is preferably ± 2·10⁻³ Pas (2 cp). Any thickener can be used in the solutions as long as it has a thickening effect and at the same time does not particularly affect the silver halide photographic light-sensitive material.

Commonly used thickeners include aqueous polymers having a sulfuric acid ester group (Japanese Patent Publication No. 21574/1961), dextran and sulfuric acid esters thereof (Japanese Patent Publication Nos. 11989/1960 and 12872/1970), polysaccharides (US Patent No. 3,767,410), polymers having a sulfonic acid group, a carboxylic acid group or a phosphoric acid group (Japanese Unexamined Patent Publication No. 18687/1983) and colloidal silica (Japanese Unexamined Patent Publication No. 36768/1983). Thickeners particularly preferred in this invention are described in Japanese Unexamined Patent Publication No. 109947/1982.

One or more thickeners other than colloidal silica may be used as the thickener. In such a case, the amount of the thickener is appropriately selected depending on the layer(s) to which it is added or the type of the agent. In short, a viscosity brought to 20·10⁻³ Pas (20 cp) or less by the thickener is satisfactory.

After being controlled by the thickener, the viscosity can be determined by measuring with a viscometer, e.g. B-type, at a liquid temperature of 35ºC.

In embodiment (a) of this invention, the amount of gelatin contained in the photographic layer components formed on the support is 2.20 to 3.10 g/m². When the amount of gelatin is in this range, the sensitivity of the light-sensitive material and the resistance to abrasion blackening can be improved to a greater extent than is possible with an amount of gelatin exceeding 3.10 g/m². When the amount is less than 2.20 g/m², the gelatin can only be coated on a support with difficulty.

Sensitizing dyes usable in this invention will now be described. The sensitizing dyes may be any substances having a desired absorption band in the visible light region; the compounds of formulas (I), (II) and (III) defined above are preferably used.

In formulas (I), (II) and (III), the carbon ring containing Z₁ and Z₂ is preferably an aromatic ring, e.g. a substituted or unsubstituted benzene ring or naphthalene ring.

In formula (I), X₁⊃min; may be, for example, a chloride ion, a bromide ion, an iodide ion, a thiocyanate ion, a sulfate ion, a perchlorate ion, a p-toluenesulfonate ion or an ethylsulfate ion.

Examples of the compound of formula (I) are:

In formula (II), the lower alkyl group represented by R6 is, for example, a methyl, ethyl, propyl or butyl group. The aryl group represented by R6 is, for example, a phenyl group. The groups represented by R4 and R5 are, for example, the groups exemplified for R1 and R3 in formula (I). X2- may also be an anion exemplified for X1- in formula (I).

Examples of compounds of formula (II) are:

In formula (III), the lower alkyl group represented by R₇ and R₉ is, for example, a methyl, ethyl, propyl and butyl group. The substituted alkyl group includes the groups exemplified for R₁ to R₃ in formula (I). The lower alkyl groups represented by R₈ and R₁₀ are exemplified by the same groups as for R₇ and R₉. The hydroxyalkyl group, sulfoalkyl group and carboxyalkyl group represented by R₈ and R₁₀ include the groups exemplified for R₁ to R₃ in formula (I).

X₃⁻ may further be an anion exemplified for X₁⁻ in formula (I).

Examples of the compound of formula (III) are:

The compounds of formulas (I), (II) and (III) can be used, for example, in a total amount of 10 mg to 900 mg per mole of silver halide. The amount is preferably between 60 mg and 600 mg.

The compounds of formulae (I), (II) and (III) can be added at any point during the course of the preparation of the light-sensitive recording material. For example, they can be added at any stage before chemical ripening, during chemical ripening, after completion of chemical ripening or before coating.

The light-sensitive material of this invention is suitable for rapid processing, whereby excellent photographs can be obtained without the above-mentioned problems even in the ultra-rapid processing mentioned above, for example.

The light-sensitive material of this invention is preferably processed in an automatic processor with a processing time of 20 to 60 seconds.

A preferred embodiment consists in using a silver halide photographic emulsion comprising silver halide grains composed essentially of silver iodobromide and having a multilayer structure, wherein the difference in average iodide content between any two layers adjacent to each other in the plurality of layers of silver halide grains having uniform iodine distribution (between coatings or between an inner core and a coating) is 10 mol% or less.

Furthermore, the outermost layer preferably has an average iodide content of 10 mol% or less, and the silver halide grains are preferably chemically sensitized.

The grains with a multilayer structure have an inner core with a coating which can have any halide composition. This coating can comprise only one layer or can be a composite of two or more layers, e.g. three or four layers, but preferably not more than five layers.

As silver halides used in the inner core and the coatings, silver bromide, silver iodobromide and silver iodide are used; they may be in a mixture with a small amount of silver chloride. More precisely, the mixture may contain 10 mol% or less, preferably 5 mol% or less, of silver chloride.

The outermost layer preferably comprises mainly silver bromide or silver iodobromide (iodide content: 10% or less) and may contain less than a few percent chloride.

The average total amount of iodide in the silver halide grains is preferably 10 mol% or less, more preferably 6 mol% or less.

For example, in X-ray photosensitive materials, iodide can sometimes aggravate problems such as development inhibition or defective development. Therefore, it is preferable to use an iodide content not exceeding a certain level. This invention can effectively reduce fogging caused by pressure. Therefore, the total iodide content in all the grains is preferably 10 mol% or less, more preferably 7 mol% or less, and most preferably 5 mol% or less.

When the inner core comprises silver iodobromide, it is preferably a homogeneous solid solution phase.

The term "homogeneous" is now explained more precisely as follows:

When an X-ray diffraction analysis is performed on the silver halide grain powder, the half-width at an area index peak [200] of silver iodide with Cu-Kβ X-rays is Δ2R = 0.30 (deg) or less. The conditions under which a diffractometer is used are such that ωτ/r ≤ 10, provided that the scanning speed of a goniometer is ω(deg/min), the time constant is τ(s), and the receiving slit width is r(mm).

The halide composition of the inner core is such that the average iodide content is preferably 40 mol% or less, more preferably 0 to 20 mol%.

The difference in silver iodide content between two adjacent layers (any two layers, or a coating and an inner core) is preferably not less than 10 mol%, preferably not less than 20 mol%, and ideally not less than 25 mol%.

The silver iodide content in a coating other than the outermost coating is preferably 10 to 100 mol%.

When the silver halide grains comprise 3 or more layers and the coatings comprise silver iodobromide, they are not necessarily all homogeneous, but all layers preferably comprise homogeneous silver iodobromide.

Such coatings (or inner core) with a high iodide content are preferably present under the outermost layer in the case of a negative type silver halide solution. In the case of a positive type silver halide solution they can be present either inside or on the surface.

The silver iodide content in the outermost coating is practically not more than 10 mol%, more preferably 0 to 5 mol%.

The iodide content in the inner core and coatings of the silver halide grains can also be determined by the method described in J.I.Goldstein and D.B. Williams, "X-ray Analysis in TEM/ATEM", Scanning Electron Microscopy (1977), Volume 1, (I.I.T. Research Institute), p. 651 (March 1977).

For example, if the silver halide grains comprise two layers, the inner core preferably has a higher iodide content than the outermost layer, and when comprising three layers, the coatings other than the outermost layer or the inner core preferably have a higher iodide content than the outermost layer.

This invention is preferably applied to silver halide grains which have already been chemically sensitized. The reason for this is that unsensitized grains can have extremely poor sensitivity, and above all neither abrasion blackening nor pressure desensitization should occur.

The silver halide grains can be of the positive or negative type.

In the case of the negative type, chemical sensitization is preferably carried out to such a degree that 60% or more of the optimum sensitization degree is achieved when a sensitivity point of "fogging + 0.1" in optical density is set.

In the case of the positive type, chemical sensitization is preferably carried out inside the grains to such a degree that 60% or more of the optimum sensitization degree is achieved when a sensitivity point of "fogging - 0.1" in optical density is set.

Other usable silver halide grains are a combination of inner fog type silver halide grains with surface latent image type silver halide grains as described in Japanese Patent Publication No. 2068/1966.

The average grain size of silver halide grains is defined as the edge length of a grain with a Volume expressed as the average volume of the granules.

In a preferred embodiment of this invention, the silver halide emulsion grains used in the silver halide emulsion layers have an average grain size of from 0.30 to 1.50 µm, preferably from 0.40 to 1.30 µm, and ideally from 0.40 to 1.10 µm.

The grain size distribution can be either narrow or wide.

The silver halide grains contained in the photographic emulsion can have any grain size distribution, but in particular they can be monodisperse. The term "monodisperse" means a system in which 95% of the grains are present at ± 60%, preferably ± 40%, of the number average grain size. The number average grain size refers to the number average diameter of the projection area of the silver halide grains.

The silver halide grains in the photographic emulsion may have a regular crystal form such as a cube, an octahedron, a tetradecahedron or a dodecahedron, an irregular crystal form such as a sphere or a disk, or a composite form of these crystal forms. The grains may comprise grains of various crystal forms.

Also available are, for example, transition type silver halide crystals formed by combining oxide crystals such as PbO with silver halide crystals such as silver chloride, silver halide crystals formed by epitaxial growth (e.g. silver chloride, silver iodobromide or silver iodide epitaxially grown on silver bromide), hexagonal crystals and crystals formed by epitaxy of regular hexahedral silver chloride on regular octahedral silver iodide.

A silver halide grain emulsion comprising an ultra-flat plate having a diameter of 5 times or more of its thickness, which accounts for 50% or more of the total projection area, can also be used. Details are described in, for example, Japanese Unexamined Patent Publications No. 127921/1983 and No. 113927/1983.

The above-mentioned regular grains refer to a silver halide emulsion in which at least 80% by weight or number of the grains have a regular shape. Silver halide grains having a regular structure or shape further include grains which have been grown isotropically without any anisotropic growth, e.g. of twin crystal faces, and have the shape of, e.g., a cube, a tetradecahedron, a regular octahedron, a dodecahedron or a sphere. A production process for such regular silver halide grains is described, for example, in Journal of Photographic Science, 5, 332 (1961), Berchte der Bunsenges Physik Chemie, 67, 949 (1963) and International Congress of Photographic Science of Tokyo (1967). Such regular silver halide grains can be obtained by controlling the reaction conditions when silver halide grains are grown using a simultaneous mixing process. In such a simultaneous mixing process, silver halide grains can be obtained by adding a silver nitrate solution and a halide solution in substantially equimolar amounts to an aqueous solution of a protective colloid with vigorous stirring.

In carrying out this invention, it is important to incorporate, for example, the above-mentioned regular silver halide grains It is also possible to incorporate irregular silver halide grains. However, if such grains are present, they should generally not be present in an amount of 50 or more weight or number percent. In a preferred embodiment, an emulsion comprises at least 60 to 70 weight percent of the regular silver halide grains.

In preparing the monodisperse emulsion and/or the emulsion containing the regular silver halide grains, the silver ions and the halide ions are preferably supplied by gradually increasing the growth rate in a continuous or stepwise manner at a critical growth rate or within an appropriate tolerance thereof to supply the silver halide in a manner necessary and appropriate for growth of only existing grains without dissolving the existing crystal grains or forming new grains to ensure the growth of the crystal grains. This method is described in Japanese Patent Publication Nos. 36890/1973 and 16364/1977 and Japanese Unexamined Patent Publication No. 142329/1980.

In other words, silver ions and halide ions are effectively supplied at such a rate that the growth rate of the silver halide grains is 30 to 100% of the critical growth rate.

This critical growth rate varies depending on, for example, temperature, pH, pAg, degree of stirring, composition of silver halide grains, solubility, grain size, distance between grains, crystal form and the type and density of the protective colloid. It can be easily determined by an experiment, e.g. microscopic observation of in a liquid phase suspended emulsion grains, or by measuring the turbidity.

The silver halide grains used in the silver halide emulsion can be prepared, for example, by a neutral process, an acid process, an ammonia process, a normal mixing process, a reverse mixing process, a double jet process, a controlled double jet process, a conversion process or a core/shell process as described in T.H. James, The Theory of the Photographic Process, 4th ed., published by Macmillan Publishing Co., Inc. (1977); P. Glafkides, Chemie et Physique Photographigue, published by Paul Montel Co., 1967; G.F. Duffin, Photographic Emulsion Chemistry, published by The Focal Press, 1966 and V.L. Zelikman et al, Making and Coating Photographic Emulsion, published by The Focal Press, 1964.

As an alternative to the double jet method, a triple jet method can be used, in which soluble halogen salts of different compositions (e.g. a soluble silver salt, a soluble bromine salt and a soluble iodine salt) are added individually.

It is also possible to use a process in which grains are formed in the presence of excess silver ions (the so-called reverse mixing process). As an embodiment of the simultaneous mixing process, it is possible to keep the pAg value constant in the liquid phase in which the silver halide is formed. This is the so-called controlled double jet process.

According to this process, it is possible to obtain a silver halide emulsion having a regular crystal shape and predominantly uniform grain size.

In the formation of silver halide grains, a silver halide solvent such as ammonia, potassium thiocyanate, ammonium thiocyanate, thioether compounds (see, for example, U.S. Patent Nos. 3,271,157, 3,574,628, 3,704,130, 4,297,439 and 4,276,374), thione compounds (see, for example, Japanese Unexamined Patent Publication No. 144319/1978, No. 82408/1978 and No. 77737/1980) and amine compounds (see, for example, Japanese Unexamined Patent Publication No. 100717/1979) can be used to control grain growth. Of these, ammonia is preferred.

Two or more kinds of separately prepared silver halide emulsions can also be used by mixing them together.

These silver halide grains or the silver halide emulsion preferably contain at least one soluble salt of iridium, thallium, palladium, rhodium, zinc, nickel, cobalt, uranium, thorium, strontium, tungsten or platinum. The salt is preferably contained in an amount of 10-6 to 10-1 mol per mol of silver. At least one salt of thallium, palladium or iridium is preferred. These may be used alone or in combination, and any point (or timing) of addition may be selected. Effects such as improvement of, for example, flash exposure, prevention of pressure desensitization and fading of the latent image, and sensitization are expected.

A mother liquor containing protective colloids is preferably maintained so that the pAg is at least 10.5 or more during the course of grain growth effected prior to the above-mentioned chemical sensitization. It is particularly preferred that the grains be passed at least once through an environment containing a large excess of bromide ions having a pAg of 11.5 or more.

In this way, the (111) area is increased and the grains are rounded, whereby the effect of this invention can be improved. Such a (111) area preferably accounts for 5% or more of the total surface area of the grains.

In such a case, the rate of increase of the (111) area (the rate of increase with respect to the grains not yet passed through the vicinity of a pAg value of 10.5 or more) is preferably not less than 10%, preferably 10 to 20%.

Regarding the question of whether the (111) area or the (100) area covers the outer surface of a silver halide grain or how to measure the ratio between them, there is a publication by Akira Hirata in the "Bulletin of the Society of Scientific Photography of Japan", No. 13, pp. 5-15 (1963).

During the course of grain growth prior to chemical sensitization, grains can be passed once through an environment in which a mother liquor containing protective colloids is maintained at a pAg of at least 10.5, and it can be easily confirmed by Hirata's method of measurement whether the (111) area has been increased to 5% or more.

In this case, the mother liquor can be prepared so that it has the above-mentioned pAg value preferably at the time after the addition of 2/3 of the total amount of silver and before a desalting step usually carried out before chemical sensitization. This is because a monodisperse emulsion with a wide grain size distribution can thus be easily obtained.

Maturation in the vicinity of pAg = 10.5 or more occurs preferably for 2 minutes or longer.

By controlling the pAg value in this way, the (111) area can be increased to 5% or more and the grains can take on a rounded shape. Thus, preferable grains with 5% or more of the (111) area with respect to the total surface area of the grain can be obtained.

In order to remove soluble salts from an emulsion after the formation of precipitates or after physical ripening, a noodle washing process carried out by gelation of gelatin may be used. A sedimentation process (or a flocculation process) using inorganic salts, anionic surfactants, anionic polymers (e.g. polystyrene sulfonic acid) or gelatin derivatives (e.g. acylated or carbamoylated gelatin) may also be used. The step of removing soluble salts may also be omitted.

The silver halide emulsion can be chemically sensitized or not, but preferably chemically sensitized. The process described in H. Frieser, The Basics of Photographic Processes with Silver Halides, Akademische Verlagsgesellschaft, 1968, pp. 675-734, can be used, for example.

More specifically, a sulfur sensitization method using active gelatin or a sulfur-containing compound capable of reacting with silver (e.g. thiosulfate, thioureas, mercapto compounds or rhodanines), a reduction sensitization method using a reducible substance (e.g. a silver tin salt, amines, hydrazine derivatives, formamidine sulfinic acid or silane compounds) and a noble metal sensitization method using a precious metal compound (e.g. gold complex salts and complex salts of metals of group VIII in the periodic table such as Pt, Ir or Pd) alone or in combination.

Specific examples are described in U.S. Patents 1,574,944, 3,410,689, 2,278,947, 2,728,668 and 3,656,955 with respect to the sulfur sensitization method, in U.S. Patents 2,983,609, 2,419,974 and 4,054,458 with respect to the reduction sensitization method, and in U.S. Patents 2,599,083 and 2,448,060 and British Patent 6,18,061 with respect to the noble metal sensitization method.

The photographic emulsion can be spectrally sensitized, for example, by a methine dye. Suitable dyes are cyanine dyes, merocyanine dyes, compound cyanine dyes, compound merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes. Particularly suitable dyes are cyanine dyes, merocyanine dyes and compound merocyanine dyes. In these dyes, any nucleus normally used in cyanine dyes as a basic heterocyclic ring nucleus can be used. For example, a pyrroline nucleus, an oxazoline nucleus, a thiazoline nucleus, a pyrole nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus, an imidazole nucleus, a tetrazole nucleus or a pyridine nucleus; a nucleus in which an aliphatic hydrocarbon nucleus is fused to any of the above nuclei, and a nucleus in which an aromatic hydrocarbon nucleus is fused to any of the above nuclei, e.g. an indolenine nucleus, a benzindolenine nucleus, an indole nucleus, a benzoxazole nucleus, a naphtoxazole nucleus, a benzothiazole nucleus, a naphtothiazole nucleus, a benzoselenazole nucleus, a benzimidazole nucleus or a quinoline nucleus. These nuclei may be substituted at a carbon atom.

In the merocyanine dyes or the compound merocyanine dyes, 5- to 6-membered heterocyclic ring cores such as a pyrazolin-5-one core, a thiohydantoin core, a 2-thiooxazolidine-2,4-dione core, a thiazolidine-2,4-dione core, a rhodanine core or a thiobarbituric acid core can be used as cores having a ketomethylene structure.

Specific examples of spectral sensitizing dyes are described in P. Glafkides, "Chemie Photographigue," 2nd ed., 1957; Paul Montel, Paris, Articles 35-41; F.M. Hamer, "The Cyanine and Related Compounds," Interscience, and in U.S. Patents 2,503,776, 3,459,553, and 3,117,210 and in Research Disclosure, Vol. 176, 17643, published December 1978, paragraph 23-IV-J.

Sensitizing dyes can be used alone or in combination. Often a combination of sensitizing dyes is used, especially for supersensitization.

Typical examples are described in U.S. Patent Nos. 2,688,543, 2,977,229, 3397,060, 3322,052, 3327,601, 3617,293, 3636,960, 3666,450, 3272,898, 3679,428, 3703,377, 3769,301, 3814,609, 3537,562 and 4026,707, British Patent Nos. 1,344,281 and 1,207,503, Japanese Patent Publication Nos. 4536/1970 and 12373/1978 and Japanese Unexamined Patent Publication Nos. 110615/1978 and 109923/1978.

The sensitizing dye can be used in the same concentration as that in ordinary negative-type silver halide emulsions. It is particularly advantageous to use it in a concentration that does not significantly reduce the sensitivity inherent in a silver halide emulsion. The sensitizing dye is preferably in a concentration of 1.0·10⁻⁵ to 5.0·10⁻⁴ mol per mole of silver halide, in particular from 4.0·10⁻⁵ to 2.0·10⁻⁴ mol per mole of silver halide.

Together with the sensitizing dye, the emulsion may contain a dye which itself has no spectral sensitizing effect or a substance which essentially does not absorb visible light and which has supersensitization.

It can contain, for example, an aminostilbene compound (e.g. the compounds described in US Pat. Nos. 3,533,590 and 3,638,721), an aromatic organic acid/formaldehyde condensate (e.g. the compound described in US Pat. No. 3,743,510), a cadmium salt or an azaindene compound. The combinations described in US Pat. Nos. 3,615,615, 3,615,641, 3,617,295 and 3,635,921 are particularly effective.

The photographic emulsion may contain various compounds to prevent fogging during production, storage or photographic processing of the light-sensitive materials or to stabilize the photographic performance. That is, it may contain a variety of compounds known as antifoggants or stabilizers, including thiazoles, e.g. benzothiazolium salts, nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoles, mercaptobenzimidazoles, mercaptothiadiazoles, aminotriazoles, benzotriazoles, nitrobenzotriazoles and mercaptotetrazoles (especially 1-phenyl-5-mercaptotetrazole), mercaptopyrimidines, mercaptotriazines, thioketo compounds such as oxazolinethione, azaindenes, e.g. B. triazaindenes, tetrazaindenes (in particular 4-hydroxy-substituted (1,3,3a,7)tetrazaindenes) or pentazaindenes, benzenethiosulfonic acid, benzenesulfinic acid or benzenesulfonic acid amide.

Details can be found, for example, in E.J. Birr, "Stabilization of Photographic Silver Halide Emulsions", Focal Press, 1974.

Suitable compounds are, for example, the thiazolium salts described in US Patents 2131038 and 2694716; the azaindenes described in US Patents 2886437 and 2444605; the urazoles described in US Patent 3287135; the sulfocatechols described in US Patent 3236632; the oxymes described in British Patent 623448; the mercaptotetrazoles described in US Patents 2403927, 3266897 and 3397987; nitrone; nitroindazoles; the polyvalent metal salts described in US Patent 2839403; the thiuronium salts described in US Patent 3,220,839 and the salts of palladium, platinum or gold described in US Patents 2,566,263 and 2,597,715.

The light-sensitive material of this invention may contain a water-soluble dye as a filter dye or for preventing radiation and halation or for any other purposes. Such a dye includes oxonol dyes, hemioxonol dyes, styryl dyes, merocyanine dyes, cyanine dyes and azo dyes. Of these, oxonol dyes, hemioxonol dyes and merocyanine dyes are particularly suitable.

In the light-sensitive material of this invention, a dye or a UV absorber, when contained in a hydrophilic colloid layer, can be mordanted by, for example, a cationic polymer.

Such a dye includes the compounds described in "Absorbing and Filter Dyes" in Research Disclosure Vol. 176, pp. 23-26.

To increase the sensitivity and contrast or to accelerate the development, the photographic emulsion layers of the light-sensitive photographic recording material of this invention may contain, for example, polyalkylene oxides, derivatives thereof, e.g. an ether, ester or amine thereof, thioether compounds, thiomorpholines, quaternary ammonium chloride compounds, urethane derivatives, urea derivatives, imidazole derivatives or 3-pyrazolidones.

It is advantageous to use gelatin as a binder or a protective colloid in the emulsion layers or interlayers of the light-sensitive material of this invention. However, the use of another hydrophilic colloid alone or in combination with gelatin is also possible.

When gelatin is used in the practice of the invention, the gelatin may, for example, be either lime or acid treated. Details of a process for the preparation of gelatin are described in Arthur Davis, The Macromolecular Chemistry of Gelatin, Academic Press (published in 1964).

The hydrophilic colloid includes, for example, proteins such as gelatin derivatives, graft polymers of gelatin with other macromolecules, albumin and casein; cellulose derivatives such as hydroxyethylcellulose, carboxymethylcellulose and cellulose sulfuric acid esters; sugar derivatives such as sodium alginate and starch derivatives; and various synthetic hydrophilic macromolecular substances such as homopolymers or copolymers of polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole or polyvinylpyrazole.

In the light-sensitive photographic recording material of this invention, the photographic emulsion layers and other hydrophilic colloid layers contain an organic or inorganic hardening agent. For example, chromium salts (such as chrome alum and chromium acetate), aldehydes (such as formaldehyde, glyoxal and glutalaldehyde), N-methylol compounds (such as dimethylol urea and methyloldimethylhydantoin), dioxane derivatives (such as 2,3-dihydroxydioxane), active vinyl compounds (such as 1,3,5-triacryloyl-hexahydro-2-triazine and 1,3-vinylsulfonyl-2-propanol), active halogen compounds (such as 2,4-dichloro-6-hydroxy-3-triazine) or mucohalogenic acids (such as mucochloric acid and mucophenoxychloric acid) can be used alone or in combination.

In the photographic light-sensitive material of this invention, the photographic emulsion layers and other hydrophilic colloid layers may contain a dispersed product of a water-soluble or slightly soluble synthetic polymer to improve dimensional stability. For example, there may be used alone or in combination alkyl acrylates or methacrylates, alkoxyalkyl acrylates or methacrylates, glycidyl acrylates or methacrylates, acryl- or methacrylamide, vinyl esters (e.g., vinyl acetate), acrylonitriles, olefins, styrenes, or polymers having monomeric components comprising a combination of these with, for example, acrylic acid, methacrylic acid, α,β-unsaturated dicarboxylic acid, hydroxyalkyl acrylates or methacrylates, sulfoalkyl acrylates or methacrylates, or styrenesulfonic acid.

Preferably, in the silver halide photographic light-sensitive material of the present invention, a protective layer is used. The protective layer is a layer comprising a hydrophilic colloid. The hydrophilic colloid may be any of those mentioned above. The protective layer may comprise either a single layer or superimposed layers.

A roughening agent and/or a smoothing agent may be added, for example, to the emulsion layers or (preferably) the protective layer of the silver halide photographic light-sensitive material of this invention. Examples of preferably used roughening agents are organic compounds such as water-dispersible vinyl polymers including polymethyl methacrylate having an appropriate grain size (preferably a grain size of 0.3 to 5 µm, or twice or more, preferably four times or more the thickness of the protective layer) or inorganic compounds such as silver halide and strontium or barium sulfate. The smoothing agent is useful, similarly to the roughening agent, for preventing adhesion difficulties and further improving frictional properties with respect to applicability in cameras for taking photographs of motion pictures or for projecting motion pictures. Specific examples preferably used are waxes such as liquid paraffin and higher aliphatic acid esters, polyfluorinated hydrocarbons and derivatives thereof and silicones such as polyalkylpolysiloxane, polyarylpolysiloxane, polyalkylarylpolysiloxane or alkylene oxide addition derivatives thereof.

If necessary, other additives may be used in the photographic light-sensitive material of this invention. They may include, for example, a dye, a development accelerator, a brightening agent, a color fogging preventing agent or an ultraviolet absorbent. Specifically, the additives described in Research Disclosure No. 176, pp. 22-31 (RD-17643, 1978) may be used.

In addition, if necessary, the silver halide photographic light-sensitive material of this invention may be provided with, for example, an anti-halation layer, an interlayer or a filter layer.

In the light-sensitive photographic material of this invention, the photographic emulsion layers or other layers are coated on one or both sides of a flexible support commonly used in light-sensitive materials. Suitable flexible supports include films comprising semi-synthetic or synthetic macromolecules such as cellulose nitrate, cellulose acetate, cellulose acetate butylate, polystyrene, polyvinyl chloride, polyethylene terephthalate or polycarbonate, and paper coated or laminated with a baryta layer or an α-olefin polymer (e.g. polyethylene, polypropylene or an ethylene/butene copolymer). The support may be colored with a dye or a pigment. It may be blackened to intercept light. The surfaces of these supports are generally adhesion-treated to improve the adhesion of a photographic emulsion. The surface of the support may be coated with, for example, a paint before or after the adhesion treatment. B. corona discharge, UV irradiation or flame treatment. The supports described in the "Supports" section in Research Disclosure, Vol. 176, p. 25, can be used.

In the photographic light-sensitive material of this invention, the photographic emulsion layers or other hydrophilic colloid layers can be coated on a support or other layers by various coating methods. Examples of coating methods include a dip coating method, a roll coating method, a curtain coating method and an extrusion coating method. The method described in the paragraph "Coating Procedures" in Research Disclosure, Vol. 176, pp. 27-28 can be used.

The silver halide photographic light-sensitive material of this invention can be specifically used, for example, as an X-ray light-sensitive material, a lithographic light-sensitive material, a black-and-white photographic light-sensitive material, a color negative light-sensitive material, a color reversal light-sensitive material, a color photographic paper, a colloid transfer processing material, a silver salt diffusion transfer processing material, a dye transfer processing material, a silver dye bleaching process material, a sensitive copying material or a sensitive heat developing material.

The exposure to produce a photographic image can be carried out using conventional methods. That is, any light source containing UV light can be used, including natural light (sunlight), a tungsten lamp, a fluorescent lamp, a mercury lamp, a xenon arc lamp, a carbon arc lamp, a xenon flash lamp, a traveling cathode ray tube light spot, a light-emitting diode or laser beams (e.g. from a gas laser, a YAG laser, a dye laser or a semiconductor laser). The exposure can also be carried out using light emitted by phosphor excited by, for example, electron beams, X-rays, gamma rays or alpha rays. The exposure can last from 1/1000 to 1 second, as in conventional cameras, but also less than 1/1000 of a second, e.g. B. 1/10⁴ to 1/10⁴ seconds using a xenon flash lamp or a cathode ray tube, or longer than 1 second. If necessary, the spectral composition of light used in the exposure can be controlled by means of a color filter.

All of the procedures and treatment solutions described in Research Disclosure No. 176, pp. 25-30 (RD-17643) can be used for the photographic processing of the light-sensitive material of this invention. This photographic processing may be either a photographic processing for forming silver images (ie, black-and-white photographic processing) or a photographic processing for forming color images (ie, color photographic processing). The processing temperature is usually 18°C to 50°C, but may be lower than 18°C or higher than 50°C.

Other development processes (e.g. heat development) can be used as required.

A developing solution used, for example, in black and white processing can contain common developing agents. Dihydroxybenzenes (e.g. hydroquinone), 3-pyrazolidones (e.g. 1-phenyl-3-pyrazolidone) or aminophenols (e.g. N-methyl-n-aminophenol) can be used as developing agents, for example, alone or in combination. In general, the developing solution can contain, in addition to these, a preservative, an alkaline substance, a pH buffering agent or an antifogging agent, as well as, if necessary, a dissolving agent, a color toner agent, a development accelerator, a surfactant, an antifoaming agent, a water softening agent, a hardening agent or a viscosity-imparting agent.

As a specific development processing system, a method of incorporating a developing agent into a light-sensitive material, e.g. emulsion layers, and developing the light-sensitive material in an aqueous alkali solution can be used. As a developing agent, a hydrophobic developing agent can be incorporated into the emulsion layers according to the methods described in Research Disclosure No. 169 (RD-16928), US-PS 2739890, GB-PS 813253 and DE-PS 1547763. Such a development treatment can be combined with a silver salt stabilization treatment carried out by means of a thiocyanate.

The fixing solution can be one with a commonly used recipe. Thiosulfate and thiocyanate can be used as the fixing agent, as well as organic sulfur compounds known to be effective fixing agents. The fixing solution can contain a water-soluble aluminum salt as a hardening agent.

The photographic emulsion layer of the photographic light-sensitive material of the present invention may contain a color image-forming coupler, e.g., a compound capable of forming a dye by reacting with an oxidized product of an aromatic primary amine (e.g., a phenylenediamine derivative or an aminophenol derivative) developing agent in color development processing. As magenta couplers, e.g., 5-pyrazolone couplers, pyrazolebenzimidazole couplers, cyanoacetylcoumarone couplers, and open-chain acylacetonitrile couplers may be used; yellow couplers may be acylacetamide couplers (e.g., benzoylacetanilides and pivaloylacetanirides), and cyan couplers may be a naphthol and a phenol coupler.

These couplers are preferably non-diffusible couplers with a hydrophobic group called a ballast group in the molecules. These couplers can be either of the four- or two-equivalence type with regard to the silver ions. In addition, colored couplers with a color-correcting effect or couplers capable of releasing a development retarder during development (so-called DIR couplers) can be used.

In addition to the DIR couplers, colorless DIR coupling compounds, which form a colorless product through the coupling reaction form and release a development retarder.

The silver halide photographic light-sensitive material of this invention may contain a color fogging preventing agent such as hydroquinone derivatives, gallic acid derivatives, aminophenol derivatives or ascorbic acid derivatives.

The silver halide photographic light-sensitive material of this invention may contain a UV absorber in the hydrophilic colloid layer. For example, For example, benzotriazole compounds substituted with an aryl group (e.g., the compounds described in U.S. Patent No. 3,533,794), 4-thiazolidone compounds (e.g., the compounds described in U.S. Patent Nos. 3,314,794 and 3,352,651), benzophenone compounds (e.g., the compounds described in Japanese Unexamined Patent Publication No. 2784/1971), cinnamic acid ester compounds (e.g., the compounds described in U.S. Patent Nos. 3,705,805 and 3,705,375), butadiene compounds (e.g., the compounds described in U.S. Patent No. 4,045,229), or benzoxydol compounds (e.g., the compounds described in U.S. Patent No. 3,700,455) can be used. The compounds described in U.S. Patent No. 3,499,762 and Japanese Unexamined Patent Publication No. 48534/1979, as well as couplers having UV absorbing properties (e.g., cyan dye-forming α-naphthol type couplers) or polymers having UV absorbing properties can also be used. The UV absorbers can be mordanted in a certain layer.

A variety of anti-color fading agents shown below may be used in combination, while color image stabilizers used in this invention may be used alone or in combination of two or more The anti-color fading agents are, for example, hyroquinone derivatives, gallic acid derivatives, p-alkoxyphenols, p-oxyphenol derivatives and bisphenols.

Generally, a color developing solution may comprise an alkaline aqueous solution containing a color developing agent. The usable color developing agent includes various primary aromatic amine developers such as phenylenediamines (e.g., 4-amino-N,N-diethylamine, 3-methyl-4-amino-N,N-diethylaniline, 4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methanesulfoamideethylaniline, or 4-amino-3-methyl-N-ethyl-N-β-methoxyethylaniline).

In addition to these agents, the agents described, for example, in L.F.A. Mason, Photographic Processing Chemistry, Focal Press (1966), pp. 226-229, in US Patents 2193015 and 2592364 and in Japanese Unexamined Patent Publication 64933/1973 can also be used.

The color developing solution may further contain, for example, a pH buffering agent such as an alkali metal sulfite, carbonate, borate or phosphate, or a development retarder or an antifoggant such as a bromide, iodide or an organic antifoggant. If necessary, it may additionally contain, for example, a water softener, a preservative such as hydroxylamine, an organic solvent such as benzyl alcohol and diethylene glycol, a development accelerator such as polyethylene glycol, quaternary ammonium salts and amines, a dye-forming color coupler, a competitive coupler, a fogging agent such as sodium borohydride, an auxiliary developing agent such as 1-phenyl-3-pyrazolidone, a viscosity-imparting agent, a polycarboxylic acid type chelating agent or an antioxidant.

After color development, the photographic emulsion layers are usually subjected to a bleaching treatment. The bleaching treatment can be carried out simultaneously with a fixing treatment or separately. Polyvalent metal compounds such as iron (III), cobalt (III), chromium (VI) and copper (II), peracids, quinones or nitroso compounds can be used as bleaching agents.

For example, iron(III) cyanide, dichromate, organic complex salts of iron(III) or cobalt(III), e.g. complex salts of aminopolycarboxylic acids such as ethylenediaminetetraacetic acid, nitrilotriacetic acid and 1,3-diamino-2-propanoltetraacetic acid, or of organic acids such as citric acid, tartaric acid and malic acid; persulfate; permanganate or nitrosophenol can be used. Of these, potassium iron(III) cyanide, sodium ethylenediaminetetraacetic acid iron(III) and ammonium ethylenediaminetetraacetic acid iron(III) are particularly suitable. Ethylenediaminetetraacetic acid iron(III) complex salts are suitable both in a separate bleaching solution and in a combined bleach-fixing solution.

This invention will now be further described in the following examples.

example 1

A silver iodobromide emulsion E-1 containing 2.0 mol% silver iodide was first prepared by regular mixing using a full ammonia process. This emulsion comprised grains with an average grain size of 1.10 µm. This silver iodobromide solution E-1 was subjected to optimum gold/sulfur sensitization by adding chloroauric acid, sodium thiosulfate and ammonium thiocyanate, followed by stabilization with 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene.

Both sides of a polyester film support subjected to an adhesion treatment were coated with the above-stabilized emulsion and a protective layer provided with a hardener to provide layers in the order of the silver halide emulsion layer and the protective layer according to a slide hopper method at a coating speed of 100 m/min so as to overlap two layers at the same time, to obtain Samples Nos. 1-28 shown in Table 1 (Table 1-a, -b, -c). The weight of the coated silver was 55 mg/dm².

The amount of hardener in each of the above samples was controlled so that the melting time was about 25 minutes. The melting time is the time at which an emulsion layer starts to melt after a sample (a silver halide photographic light-sensitive material) cut into 1 cm x 2 cm pieces was immersed in an aqueous solution of 1.5% sodium hydroxide at 50°C.

The number and extent of coating defects (such as coating streaks and unevenness) on the test pieces were then measured and rated using a 5-level system from 1 (poor) to 5 (excellent). A rating of 3 to 5 indicates no problems at all, while a rating of 1 to 2 means unsuitable for practical use.

The sensitivity was also measured as follows. A test specimen was placed between two step wedges, with the density inclination set to be mirror-symmetrical, and then irradiated from both sides in equal amounts for 1/12.5 second with a light source with a color temperature of 5400ºK.

The treatment was carried out according to the following steps using a roller feed type automatic treatment device. The total treatment time was 45 seconds. Treatment temperature Treatment time Introduction Developing & Transferring Fixing & Transferring Washing & Transferring Rubber squeezing Drying Total

The developing and fixing solutions used were XD-90 and XF (both trade names; manufactured by Konishiroku Photo Industry Co., Ltd.), respectively.

Based on the characteristic curve representing the relationship between log E (the logarithm of the exposure amount) and D (optical density), the exposure amount at a base density + density density + 1.0 was obtained to determine the relative sensitivity.

The drying properties were further evaluated as follows. After performing the above automatic treatment, a touch on the samples passed through the drying area and the degree of adhesion to other samples were evaluated overall using the 5-level system from 1 (poor) to 5 (excellent). A rating of 3 to 5 indicates no difficulty, while a rating of 1 to 2 means unsuitability for practical use. The results obtained are summarized in Table 1 (Table 1-c) is shown. In the rightmost column of the table, a test specimen according to the invention is marked "Yes" and a test specimen not according to the invention is marked "No".

A portion of the samples were treated to obtain the sensitivity in a conventional 90-second treatment by reducing the conveying path speed of the above-mentioned 45-second automatic treatment device to half. The results obtained are shown in Table 2.

As is clear from Table 1 (Table 1-a, -b, -c) and Table 2, the samples (silver halide photographic light-sensitive materials) of this invention have good coating properties, excellent drying properties and excellent sensitivity, making them suitable for ultra-high-speed processing. Furthermore, a comparison with the conventional 90-second processing shows that the processing time can be shortened to 1/2, thus producing twice the processing capability while maintaining the sensitivity achieved in the conventional system. Table 1: (Table 1-a) Test specimen No. Silver halide emulsion layer Gelatin amount per side Surfactant type Amount per side Surface tension (Table 1-b): Sample No. Protective layer Gelatin quantity on 1 side Surfactant type Quantity on 1 side Surface tension (Table 1-c): Sample No. Total gelatine quantity on 1 side Diff.* in surface tension Coating defects Sensitivity Drying properties Remarks *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention Table 2 Sample No. Total gelatine quantity on 1 side Difference in surface tension Sensitivity 45-second treatment 90-second treatment

Example 2

The preparation of silver halide grains having a multilayer structure-containing emulsions E-2 to E-6 is described here. First, a 3.0 N ammoniacal silver nitrate solution and a solution containing 2.0 mol% potassium iodide and 98.0 mol% potassium bromide were added according to a double jet method at 45°C while maintaining a pAg of 11.0 and a pH of 9.0. The addition rate was gradually increased with the growth of the grains.

The obtained emulsion was found to be an octahedral monodisperse emulsion containing grains having an average grain size of 1.05 µm. In addition, to form shells containing silver bromide alone, an ammoniacal silver nitrate solution and a potassium bromide solution were mixed according to a double jet method at a pAg of 11.0 and a pH of 9.0. The thus obtained emulsion was found to be an octahedral monodisperse emulsion containing grains having an average grain size of 1.10 µm. monodisperse emulsion. This emulsion was called E-2.

Subsequently, octahedral silver iodobromide emulsions containing 5 mol%, 10 mol%, 20 mol% and 30 mol% silver iodide were prepared by using substantially the same preparation procedure as for E-2 except that the ratio of potassium iodide to potassium bromide was changed and the core size was varied so as to uniform the average silver content after shell formation, while controlling the addition rate at an initial stage of mixing so as to obtain the same grain size. Then, the same procedures as for E-2 were carried out to prepare corresponding octahedral monodisperse emulsions having grains having an average grain size of 1.10 µm, called E-3, E-4, E-5 and E-6.

Chemical sensitization and coating were carried out on the emulsions E-1 to E-6 in the same manner as in Example 1 to obtain Sample Nos. 29 to 38 as shown in Table 3 (Table 3-a, -b, -c).

These specimens were subjected to the 45 second treatment of Example 1 to determine sensitivity. Abrasion blackening was further measured in the following manner: The specimens were humidity conditioned at 23ºC and 55% relative humidity for 4 hours and then scratched with a 0.3 mil (7.6 µm) radius sapphire needle while continuously changing the load, followed by developing the load (g) at which blackening began to indicate abrasion blackening. The smaller the value, the weaker the abrasion blackening.

The results obtained are shown in Table 3 (Table 3-c). As is clear from Table 3, in the grains having a difference of 10 mol% or more in iodine content between core and shell, the abrasion blackening occurs to a lesser extent and the sensitivity is excellent at a lower gelatin content, compared with the grains having a difference of less than 10 mol%. Table 3 (Table 3-a) Sample No. Emulsion Silver halide emulsion layer Gelatin amount per side Surfactant type Amount per side Surface tension (Table 3-b) Sample No. Protective layer Gelatin quantity on 1 side Surfactant type Quantity on 1 side Surface tension (Table 3-c) Sample No. Total gelatine quantity on 1 side Diff. in surface tension between Emulsion layer and protective layer Sensitivity Abrasion blackening

Example 3

Core grain-containing emulsions were prepared by the same procedure as for E-3 to E-6. Octahedral silver iodobromide emulsions containing 5 mol%, 10 mol%, 20 mol% and 30 mol% silver iodide were obtained. Following the same procedure as for E-2, except that 2.0 mol% of shell potassium iodide was included in each of these emulsions, corresponding octahedral monodisperse core/shell emulsions comprising grains having an average grain size of 1.10 µm were prepared, called E-7, E-8, E-9 and E-10, respectively.

On these monodisperse emulsions, chemical sensitization and coating were carried out in the same manner as in Example 1 to obtain Sample Nos. 39-46 shown in Table 4 (Table 4-a, -b, -c). On these samples, abrasion blackening and sensitivity were determined in the same manner as in Example 2 to obtain the results shown in Table 4 (Table 4-c).

As shown in Table 4, in the grains having a difference of 10 mol% or more in iodine content between core and shell, abrasion blackening occurs to a lesser extent and the sensitivity is excellent with a lower gelatin content, compared with the grains having a difference of less than 10 mol%. Table 4 (Table 4-a) Sample No. Emulsion Silver halide emulsion layer Gelatin amount per side Surfactant type Amount per side Surface tension (Table 4-b) Sample No. Protective layer Gelatin quantity on 1 side Surfactant type Quantity on 1 side Surface tension (Table 4-c) Sample No. Total gelatine quantity on 1 side Diff. in surface tension (between emulsion layer and protective layer) Sensitivity Abrasion blackening

Example 4

A cubic monodisperse emulsion comprising silver iodobromide grains having an average grain size of 0.28 µm and containing 2.5 mol% of silver iodide was prepared according to a double jet method at 60°C, pAg = 8.0 and pH = 2.0. A part of this emulsion was used as cores and grown in the following manner. To the solutions containing the core grains and gelatin were mixed an ammoniacal silver nitrate solution and a solution containing potassium iodide and potassium bromide at 40°C, pAg = 8.0 and pH = 9.5 according to a double jet method to form a first layer containing 5 mol%, 10 mol%, 20 mol% or 30 mol% of silver iodide, respectively.

Each of the emulsions was treated to form a second layer comprising silver bromide alone by the same procedure as for E-2, except that the pAg was 9.0, to prepare core/shell emulsions containing cubic monodisperse silver iodobromide grains having an average grain size of 1.0 µm, designated E-11, E-12, E-13, and E-14, respectively. All of these emulsions had an average silver iodide content of 3.0 mol%.

These monodisperse emulsions were subjected to chemical sensitization and coating in the same manner as in Example 1 to obtain Sample Nos. 47-54 shown in Table 5 (Table 5-a, -b, -c). These samples were tested for abrasion blackening and sensitivity in the same manner as in Example 2 to obtain the results shown in Table 5 (5-c).

As can be seen from Table 5 (Table 5-a, -b, -c), in the grains with a difference of 10 mol% or more in the iodine content between the core and the shell, the abrasion blackening occurs to a lesser extent and the sensitivity is lower gelatin content compared to the granules with a difference of less than 10 mol%. Table 5 (Table 5-a) Sample No. Emulsion Silver halide emulsion layer Gelatin amount per side Surfactant type Amount per side Surface tension (Table 5-b) Sample No. Protective layer Gelatin quantity on 1 side Surfactant type Quantity on 1 side Surface tension (Table 5-c) Sample No. Total gelatine quantity on 1 side Diff. in surface tension (between emulsion layer and protective layer) Sensitivity Abrasion blackening

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Example 5

Example 1 was repeated to prepare Emulsion E-15 except that the thickeners and surfactants mentioned below were used. Using this Emulsion E-15, chemical sensitization and coating were carried out by the same method as in Example 1 to obtain Sample Nos. 55-110. Then, experiments were carried out in the same manner as in Example 1. The results are shown in Tables 6 and 7.

Thickener:

(A)

(B) Colloidal silica (Ludox AM, manufactured by DuPont)

The surfactants used were the previously defined surfactants 1-10, 2-26, 2-80 and 3-3 and the following compounds (1) to (3).

As is clear from Table 6 (Table 6-a, -b, -c) and Table 7, the samples (silver halide photographic light-sensitive materials) of this invention have good coating properties and also excellent sensitivity and drying properties, making them suitable for ultra-fast processing. Comparison with the conventional 90-second processing also shows that the processing time can be shortened to 1/2 and double the processing ability can be achieved while maintaining the sensitivity achieved in the conventional system.

Example 5 was repeated except that dextran was used as a thickener in the emulsion layer instead of compound (A). The same result as in Example 5 was observed.

Example 5 was repeated again except that the melting time was changed to 20 minutes. The same result was observed. Table 6: (Table 6-a) Sample No. Amount of gelatin on 1 side Type of surfactant By surface tension Type of thickener Viscosity (Table 6-b) Sample No. Amount of gelatin on 1 side Type of surfactant surface tension type of thickener viscosity (Table 6-c) Sample No. Total gelatin amount on 1 side Diff.* in surface tension Diff.* in viscosity Coating defect Sensitivity Drying property Remarks *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention Table 6 (continued) (Table 6-a, continued) Sample No. Silver halide emulsion layer Amount of gelatin per side Type of surfactant By surface tension Type of thickener Viscosity (Table 6-b, continued) Sample No. Protective layer Gelatin quantity on 1 side Type of surfactant surface tension type of thickener viscosity (Table 6-c, continued) Sample No. Total gelatine amount on 1 side Diff.* in surface tension Diff.* in viscosity Coating defects Sensitivity Drying properties Remarks *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention Table 7 Sample No. Total gelatine quantity on 1 side Diff. in surface tension Diff. in viscosity Sensitivity 45-second treatment 90-second treatment

Example 6

Example 2 was repeated to prepare emulsions E-16 to E-20 except that the thickeners and surfactants of Example 5 were used. Chemical sensitization and coating were carried out by the same procedures as in Example 2 to obtain Samples Nos. 111-120 shown below. Experiments were carried out in the same manner as in Example 2 on these samples. The results obtained are shown in Table 8 (Table 8-a, -b, -c).

As shown in Table 8, in the grains having a difference of 10 mol% or more in iodine content between the core and the shell, the abrasion blackening occurs to a lesser extent and the sensitivity is excellent with a smaller amount of gelatin, compared with the grains having a difference of less than 10 mol%. Table 8: (Table 8-a) Sample No. Emulsion Silver halide emulsion layer Gelatine quantity per page Type of surface-active By surface tension Type of thickener Viscosity (Table 8-b) Sample No. Protective layer Gelatin quantity on 1 side Type of surface active By surface tension Type of thickener Viscosity (Table 8-c) Test item no. Total gelatine quantity on 1 side Diff.* in surface tension Diff.* in viscosity Sensitivity Abrasion blackening *Difference (between emulsion layer and protective layer)

Example 7

Core grain-containing emulsions were prepared by the same procedures as for E-17 to E-20 to obtain octahedral silver iodobromide emulsions containing 5 mol%, 10 mol%, 20 mol%, and 30 mol% silver iodide, respectively. By the same procedure as for E-16, except that 2.0 mol% shell potassium iodide was included in each of these emulsions, corresponding tetrahedral monodisperse core/shell emulsions comprising grains having an average grain size of 1.10 µm were prepared, designated E-21, E-22, E-23, and E-2, respectively.

On these monodisperse emulsions, chemical sensitization and coating were carried out in the same manner as in Example 5 to obtain Sample Nos. 121 to 128 shown in Table 9 (Table 9-a, -b, -c) below. On these samples, abrasion blackening and sensitivity were determined in the same manner as in Example 6 to obtain the results shown in Table 9 (Table 9-c).

As shown in Table 9, in the grains having a difference of 10 mol% or more in iodine content between core and shell, abrasion blackening occurs to a lesser extent and the sensitivity at a lower gelatin content is excellent, compared with the grains having a difference of less than 10 mol%. Table 9 (Table 9-a) Sample No. Emulsion Silver halide emulsion layer Amount of gelatin per side Type of surfactant Surface tension Type of thickener Viscosity (Table 9-b) Sample No. Protective layer Amount of gelatin on 1 side Type of surfactant Surface tension Type of thickener Viscosity (Table 9-c) Sample No. Total gelatine quantity on 1 side Diff.* in surface tension Diff.* in viscosity Sensitivity Abrasion blackening *Difference (between emulsion layer and protective layer)

Example 8

Example 4 was repeated to prepare emulsions E-25 to E-28, except that the thickeners and surfactants of Example 5 were used. Chemical sensitization and coating were carried out on these samples by the same procedures as in Example 4, to obtain Sample Nos. 129 to 136 shown in Table 10 (Table 10-a, -b, -c). Experiments were carried out in the same manner as in Example 4, to obtain the results shown in Table 10 (Table 10-c).

As shown in Table 10 (Table 10-a, -b, -c), in the grains having a difference of 10 mol% or more in iodine content between core and shell, abrasion blackening occurs to a lesser extent and the sensitivity is excellent at a lower gelatin content. Table 10: (Table 10-a) Sample No. Emulsion Silver halide emulsion layer Amount of gelatin per side Type of surfactant Surface tension Type of thickener Viscosity (Table 10-b) Sample No. Protective layer Amount of gelatin on 1 side Type of surfactant Surface tension Type of thickener Viscosity (Table 10-c) Sample No. Total gelatine quantity on 1 side Diff.* in surface tension Diff.* in viscosity Sensitivity Abrasion blackening *Difference (between emulsion layer and protective layer)

Example 9

In this example, using the emulsion of Example 5, the sensitizing dyes shown as the examples of the compounds of formulas (I) to (III) or the comparative dyes (a) to (c) shown below were blended. Then, hydrochloric acid of gold, sodium thiosulfate and ammonium thiocyanate were blended to perform optimum gold and sulfur sensitization, followed by stabilization with 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene. The weight of the silver coating was 45 mg/dm2, using conditions otherwise the same as those in the procedures of Example 5 to obtain Samples Nos. 137-197 shown in Table 11 below (Table 11-a, -b, -c). For these samples, coating defects, sensitivity and drying properties were evaluated in the same manner as in Example 5, and the results shown in Table 12 below were obtained.

Comparison dye (a)

Comparison dye (b)

Comparison dye (c)

R.M.S. grain size was measured in the following manner.

Each sample was inserted into an orthochromatic sensitizing screen KS (manufactured by Konishiroku Photo Industry Co., Ltd.), irradiated with X-rays for 0.10 seconds at a tube voltage of 90 KVP and a tube current of 100 mA using an aluminum wedge, followed by the above-mentioned 45-second treatment. Then, an emulsion layer of the sample was removed at a location with a density of 1.0, and the other emulsion surface was measured under an aperture size of 50 x 200 µm at the front side opposite an X-ray generator using a Sakura RMS single-touch type detector (manufactured by Konishiroku Photo Industry Co., Ltd.). The smaller the measured value, the better the grain.

Similarly to Example 5, a portion of the samples were treated to determine the sensitivity after the conventional 90-second treatment by reducing the conveying line speed of the above-mentioned 45-second automatic treatment device to 1/2. The results obtained are shown in Table 13.

As can be seen from Tables 12 and 13, the samples of the invention have good coating properties and also excellent sensitivity and drying properties, making them suitable for ultra-fast treatment. The comparison with the conventional 90-second Treatment also shows that the treatment time can be reduced to 1/2, achieving twice the treatment capacity while maintaining the sensitivity achieved with the conventional system. Table 11: (Table 11-a) Sample No. Emulsion Silver halide emulsion layer Gelatin amount on one side Type of surfactant Surface tension Type of thickener Viscosity (Table 11-b) Sample No. Protective layer Gelatin quantity on 1 side Type of surfactant Surface tension Type of thickener Viscosity (Table 11-c) Sample No. Total gelatin amount on 1 side Diff.* in surface tension Diff.* in viscosity Sensitizing dye Type Quantity Remarks *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention Table 11 (continued) (Table 11-a, continued) Sample No. Emulsion Silver halide emulsion layer Amount of gelatin per side Type of surfactant Surface tension Type of thickener Viscosity (Table 11-b, continued) Sample No. Protective layer Amount of gelatin on 1 side Type of surfactant Surface tension Type of thickener Viscosity (Table 11-c, continued) Sample No. Total gelatin amount on 1 side Diff.* in surface tension Diff.* in viscosity Sensitizing dye Type Quantity Remarks *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention Table 11 (continued): (Table 11-a, continued) Sample No. Emulsion Silver halide emulsion layer Amount of gelatin per side Type of surfactant Surface tension Type of thickener viscosity (Table 11-b, continued) Sample No. Protective layer Amount of gelatin on 1 side Type of surfactant Surface tension Type of thickener Viscosity (Table 11-c, continued) Sample No. Total gelatin amount on 1 side Diff.* in surface tension Diff.* in viscosity Sensitizing dye Type Quantity Remarks *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention Table 12 Test specimen No. Coating defect Sensitivity Drying properties Grain size Remarks Yes: according to the invention No: not according to the invention Table 12 (continued) Test item No. Coating defect Sensitivity Drying properties Grain size Remarks Yes: according to the invention No: not according to the invention Table 13 Sample No. Total gelatine quantity on 1 side Diff. in surface tension Diff. in viscosity Sensitizing dye Sensitivity 45-sec. treatment 90-sec. treatment

Example 10

Using the emulsion of Example 6, sensitizing dyes (2) were added, followed by adding gold hydrochloric acid, sodium thiosulfate and ammonium thiocyanate to perform optimum gold and sulfur sensitization, followed by stabilization with 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene. The weight of the silver coating was 45 mg/dm2, and the other conditions were the same as in the procedures of Example 5. Samples shown in Table 14 below (Table 14-a, -b, -c) were obtained.

Experiments were conducted on these samples in the same manner as in Example 6, and the results shown in Table 15 below were obtained.

As can be seen from Table 15, in the grains with a difference of 10 mol% or more in the iodine content between the core and the shell, abrasion blackening occurs to a lesser extent and the sensitivity is excellent at lower gelatin content compared to the grains with a difference of less than 10 mol%.

Similar experiments were performed using sensitizing dyes (44) and (74), giving similar results. Table 14: (Table 14-a) Sample No. Emulsion Silver halide emulsion layer Amount of gelatin per side Type of surfactant Surface tension Type of thickener Viscosity (Table 14-b) Sample No. Protective layer Amount of gelatin on 1 side Type of surfactant Surface tension Type of thickener Viscosity (Table 14-c) Sample No. Total gelatine quantity on 1 side Diff.* in surface tension Diff.* in viscosity Sensitizing dye Type Quantity *Difference (between emulsion layer and protective layer) Table 15 Test item No. Sensitivity Abrasion blackening

Example 11

Two kinds of silver iodobromide emulsions containing 3.0 mol% silver iodide were prepared by regular mixing in the full ammonia method. They comprised grains of an average grain size of 1.10 µm and 0.80 µm and are designated as emulsions E-29 and E-30, respectively. To these emulsions E-29 and E-30, the sensitizing dyes shown in Table 16 (Table 16-c) were added. Then, hydroauric acid, sodium thiosulfate and ammonium thiocyanate were added to carry out optimum gold and sulfur sensitization, followed by stabilization with 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene.

Both sides of a polyester film support previously subjected to an adhesion treatment were coated with a protective layer added with a hardener together with the above-mentioned emulsions to form layers in the order of the silver halide emulsion layer and the protective layer according to a sliding funnel method at a Coating speed of 100 m/min so that two layers overlap at the same time, thereby obtaining Samples Nos. 208-230. The amount of gelatin, the difference in surface tension, amount and kind of surfactants and sensitizing dyes are shown in Table 16 (Table 16-a, -c, -b) with reference to the exemplary compound number shown above (and comparative dye number shown below).

The silver weight was 45 mg/dm².

The amount of hardener in each of the above-listed test specimens was chosen so that the melting time was approximately 30 minutes.

When measuring the R.M.S. grain, the sample containing no sensitizing dye was inserted into a regular sensitizing screen NS (manufactured by Konishiroku Photo Industry Co., Ltd.) and the sample containing a sensitizing dye was inserted into an orthochromatic sensitizing screen KS (manufactured by Konishiroku Photo Industry Co., Ltd.).

The measurement of pressure desensitization was carried out in the following manner. Each sample was humidity conditioned at 23ºC and 35% RH for 5 hours and folded under the same conditions at about 28º with a radius of curvature of 2 cm. Three (3) minutes after folding, the sample was exposed to light for development by means of a step wedge with a tungsten lamp as a light source for 1/10 second. The difference in density between the part with a density of 1.0 in which desensitization due to folding had occurred and the density of 1.0 in the part in which the sample had not been folded was indicated by ΔD. Consequently, the lower the value, the less pressure desensitization will occur.

The results obtained are shown in Table 17.

A portion of the samples were also treated to achieve sensitivity in a conventional 90-second treatment by lowering the conveying line speed of the above-mentioned automatic 45-second treatment device to 1/2 the sensitivity in a conventional 90-second treatment. The results are shown in Table 18.

As is clear from Tables 17 and 18, the samples of the present invention have good coating properties and also excellent sensitivity, graininess and drying properties as well as excellent pressure desensitization and abrasion blackening properties, making them suitable for ultra-fast processing. Comparison with the conventional 90-second processing also shows that the sensitivity is higher than that of the conventional system, but the processing time can be reduced to 1/2, thereby achieving twice the processing ability. Table 16: (Table 16-a) Sample No. Silver halide emulsion layer Emulsion Gelatin amount on 1 side Surfactant Type Quantity on 1 side Surface tension (Table 16-b) Sample No. Protective layer Gelatin quantity on 1 side Surfactant type Quantity on 1 side Surface tension (Table 16-c) Sample No. Total gelatin amount on 1 side Diff.* in surface tension Sensitizing dye Type Amount Remarks Compound *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention Table 17 Test item No. Coating defect Sensitivity Grain size Pressure desensitization Abrasion blackening (g) Drying properties (Table 18) Sample No. Total gelatin on 1 side Diff. in surface tension Amount of sensitizing dye Sensitivity 45-sec. treatment 90-sec. treatment

Example 12

The preparation of silver halide grains having a multilayer structure-containing emulsions E-31 to E-35 is described here. A 3.0 N ammoniacal silver nitrate solution and a solution containing 2.0 mol% potassium iodide and 98.0 mol% potassium bromide were added into a gelatin solution according to a double jet method at 45°C while maintaining a pAg of 11.0 and a pH of 9.0. The addition rate was gradually increased with the growth of the grains.

The obtained emulsion was found to be an octahedral monodisperse emulsion comprising grains having an average grain size of 0.70 µm. While maintaining a pAg value at 11.0 and a pH value at 9.0, an ammoniacal silver nitrate solution and a potassium bromide solution were further added according to a double jet method to form shells comprising silver bromide alone. An octahedral monodisperse emulsion comprising grains having an average grain size of 0.75 µm was obtained. This emulsion was named E-31.

According to substantially the same procedures as for E-31, but varying the ratio of potassium iodide to potassium bromide, varying the core size to uniformize the average silver iodide content after the formation of shells, and controlling the addition rate at an initial stage of mixing, octahedral silver iodobromide solutions containing 5 mol%, 10 mol%, 25 mol% and 40 mol% silver iodide were prepared. Subsequent steps were the same as those for E-31, so that octahedral monodisperse emulsions containing grains of an average grain size of 0.75 µm, called E-32, E-33, E-34 and E-35, respectively, were prepared. For E-29 and E-31 to E-35, chemical sensitization and coating were carried out in the same manner as in Example 1 to obtain Samples Nos. 231-239. Profiles of the samples are shown in Table 19 (19-a, -b, -c).

These samples were evaluated in the same manner as in Example 10, and the results shown in Table 20 were obtained.

As is clear from Table 20, the samples of the present invention have excellent properties in sensitivity, graininess, pressure desensitization and abrasion blackening on the whole. The comparison with the conventional 90-second treatment also shows that the sensitivity is higher than that of the conventional system (Samples Nos. 231 and 235), and the treatment time can be reduced to 1/2, so that the treatment ability is doubled. Table 19 (Table 19-a) Sample No. Silver halide emulsion layer Emulsion Gelatin amount per side Surfactant Type Amount per side Surface tension (Table 19-b) Test specimen No. Protective layer Gelatin quantity on 1 side Surfactant type Quantity on 1 side Surface tension (Table 19-c) Sample No. Total gelatin amount on 1 side Diff.* in surface tension Sensitizing dye Type Quantity Remarks Compound Comparison *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention Table 20 Sample No. Sensitivity 45-s treatment 90-s treatment Grain size Pressure desensitization Abrasion blackening

Example 13

Formation of core grains was carried out by the same procedures as for E-32 to E-35 to prepare octahedral silver iodobromide emulsions containing 5 mol%, 10 mol%, 25 mol% and 40 mol% silver iodide. By the same procedure as for E-31, except that shells containing 1.0 mol% potassium iodide were formed, octahedral monodisperse emulsions containing grains having an average grain size of 0.75 µm were prepared, named E-36, E-37, E-38 and E-39, respectively.

Chemical sensitization and coating were carried out on these emulsions in the same manner as in Example 10 to obtain Sample Nos. 240-247. Profiles of the samples are shown in Table 21 (Table 21-a, -b, -c).

These samples were evaluated in the same manner as in Example 10 to obtain the results shown in Table 22. Table 21: (Table 21-a) Sample No. Silver halide emulsion layer Emulsion Gelatin amount per side Surfactant Type Amount per side Surface tension (Table 21-b) Sample No. Protective layer Gelatin quantity on 1 side Surfactant type Quantity on 1 side Surface tension (Table 21-c) Sample No. Total gelatin amount on 1 side Diff.* in surface tension Sensitizing dye Type Amount Remarks Compound Comparison *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention

Blank page Table 22 Sample No. Sensitivity 45-s treatment 90-s treatment Grain size Pressure desensitization Abrasion blackening

As shown in Table 22, the samples of the invention have excellent properties in terms of sensitivity, graininess, pressure desensitization and abrasion blackening on the whole. Furthermore, the comparison with the conventional 90-second treatment shows that the sensitivity is higher than that of the conventional system (samples Nos. 240 and 243), and in addition the treatment time can be reduced to 1/2, resulting in twice the treatment ability.

Example 14

A cubic monodisperse emulsion comprising silver iodobromide grains of an average grain size of 0.28 µm and containing 2.0 mol% of silver iodide was prepared by a double jet method with temperature control at 60°C, pAg = 8.0 and pH = 2.0. A part of this emulsion was used as cores and grown in the following manner. To the solutions containing core grains and gelatin were added an ammoniacal silver nitrate solution and a solution containing potassium iodide and potassium bromide at 40°C, pAg = 8.0 and pH = 9.5 according to a double jet method. to form a first coating containing 5 mol%, 10 mol%, 25 mol% or 40 mol% silver iodide.

Each of these emulsions was treated in the same manner as for E-2, except that the pAg was 9.0, to form a second coating containing silver bromide alone, thereby preparing core/shell emulsions comprising cubic monodisperse silver iodobromide grains with an average grain size of 0.65 µm, designated E-40, E-41, E-42, and E-43, respectively. All of these emulsions were prepared with an average silver iodide content of 3.0 mol%.

These monodisperse emulsions were subjected to chemical sensitization and coating in the same manner as in Example 10 to obtain Sample Nos. 248-255. Profiles of the Samples are shown in Table 23 (Table 23-a, -b, -c).

These samples were evaluated in the same manner as in Example 10 to obtain the results shown in Table 24. Table 23: (Table 23-a) Sample No. Silver halide emulsion layer Emulsion Gelatin amount per side Surfactant Type Amount per side Surface tension (Table 23-b) Sample No. Protective layer Gelatin quantity on 1 side Surfactant type Quantity on 1 side Surface tension (Table 23-c) Sample No. Total gelatin amount on 1 side Diff.* in surface tension Sensitizing dye Type Quantity Remarks Compound Comparison *Difference (between emulsion layer and protective layer) Yes: according to the invention No: not according to the invention (Table 24) Sample No. Sensitivity 45-s treatment 90-s treatment Grain size Pressure desensitization Abrasion blackening

As shown in Table 24, the samples of the invention have excellent properties in terms of sensitivity, graininess, pressure desensitization and abrasion blackening on the whole. Furthermore, the comparison with the conventional 90-second treatment shows that the sensitivity is higher than that of the conventional system (Samples Nos. 248 and 251) and the treatment time can be reduced to 1/2, so that the treatment ability is doubled.

As described above, this invention provides a silver halide photographic light-sensitive material having excellent sensitivity, contrast, maximum density, fixability and drying properties even in an ultra-fast processing with a total processing time of 20 seconds to 60 seconds.

This invention also provides a silver halide photographic light-sensitive material which, even with a small amount of gelatin, has less disturbance during the coating step, less abrasion blackening or pressure desensitization and also has excellent grain.

Claims (12)

1. Light-sensitive silver halide photographic material having photographic layers coated under conditions such that the surface tension of a coating solution for forming an outermost layer is 6·10⁻³ N/m (6 dyne/cm) or more below the surface tension of a solution for forming the layer adjacent to the outermost layer, the photographic material satisfying at least one of the conditions: (a) the amount of gelatin in all layers at least on the side of the support with a light-sensitive silver halide emulsion layer and a hydrophilic colloid layer is 2.20 to 3.10 g/m², (b) the coating solution for forming the outermost layer and the solution for forming the layer adjacent to the outermost each have a viscosity of 20·10⁻³ Pas (20 cp) or less. 2. Photographic recording material according to claim 1, comprising at least one silver halide emulsion layer containing at least one compound of the formulas (I), (II) and (III): wherein R₁, R₂ and R₃, which may be the same or different, each represent a substituted or unsubstituted alkyl group, alkenyl group or aryl group, at least one of the groups R₁ and R₃ represents a sulfoalkyl group or a carboxyalkyl group; X₁⊃min; represents an anion; Z₁ and Z₂, which may be the same or different, each represent a group of non-metallic atoms which, together with the carbon atoms to which it is bonded, forms a substituted or unsubstituted carbon ring; n = 1 or 2, provided that n = 1 when an intramolecular salt is formed; Formula (II): wherein R₄ and R₅, which may be the same or different, each represent a substituted or unsubstituted alkyl group, alkenyl group or aryl group, at least one of the groups R₄ and R₅ representing a sulfoalkyl group or a carboxyalkyl group; R₆ represents a hydrogen atom, a lower alkyl group or an aryl group; X₂⊃min; represents an anion; Z₁ and Z₂, which may be the same or different, each represent a group of non-metallic atoms which together with the carbon atoms to which it is bonded form a substituted or unsubstituted carbon ring; n = 1 or 2, provided that n = 1 when an intramolecular salt is formed; Formula (III): wherein R₇ and R₉, which may be the same or different, each represent a substituted or unsubstituted lower alkyl group; R₈ and R₁₀, which may be the same or different, each represent a lower alkyl group, a hydroxyalkyl group, a sulfoalkyl group or a carboxyalkyl group; X₃⁻ represents an anion; Z₁ and Z₂, which may be the same or different, each represent a group of non-metallic atoms which, together with the carbon atoms to which it is bonded, forms a substituted or unsubstituted carbon ring; n = 1 or 2, provided that n = 1 when an intramolecular salt is formed. 3. A photographic recording material according to claim 2, wherein X₁⁻ represents a chloride ion, a bromide ion, an iodide ion, a thiocyanate ion, a sulfate ion, a perchlorate ion, a p-toluenesulfonate ion or an ethylsulfate ion; and wherein the substituted or unsubstituted carbon ring containing Z₁ and Z₂ in formula (I) is a substituted or unsubstituted benzene or naphthalene ring. 4. A photographic recording material according to claim 2, wherein R₆ represents a methyl group, an ethyl group, a propyl group, a butyl group or a phenyl group; X₂⊃min; a chloride ion, a bromide ion, an iodide ion, a thiocyanate ion, a sulfate ion, a perchlorate ion, a p-toluenesulfonate ion or an ethylsulfate ion; and wherein the substituted or unsubstituted carbon ring contained in Z₁ or Z₂ in formula (II) is a substituted or unsubstituted benzene or naphthalene ring. 5. A photographic recording material according to claim 2, wherein at least one of the groups R₇ and R₉ represents a methyl group, an ethyl group, a propyl group or a butyl group; wherein at least one of the groups R₈ and R₁₀ represents a methyl group, an ethyl group, a propyl group or a butyl group; X₃⁻ is a chloride ion, a bromide ion, an iodide ion, a thiocyanate ion, a sulfate ion, a perchlorate ion, a p-toluenesulfonate ion or an ethylsulfate ion; and wherein the substituted or unsubstituted carbon ring containing Z₁ or Z₂ in formula (III) is a substituted or unsubstituted benzene or naphthalene ring. 6. Photographic recording material according to one of claims 2 to 5, wherein the total amount of the compounds of formulae (I), (II) and (III) contained in the silver halide emulsion layer is 10 mg to 900 mg per 1 mol of silver halide in the silver halide emulsion layer. 7. A photographic recording material according to any one of claims 2 to 6, wherein the silver halide emulsion layer contains silver halide grains mainly containing silver iodobromide and having a multilayer structure, the difference in the average iodine content of the silver halide grains between two layers adjacent to each other in the plurality of layers having a uniform iodine distribution being 10 mol% or less. 8. Photographic recording material according to claim 7, wherein the inner core and the layers of the multilayer Silver halide grains contain silver bromide, silver iodobromide or silver iodide. 9. A photographic recording material according to claim 7 or 8, wherein the outermost layer of the multilayered silver halide grains mainly contains silver bromide or silver iodobromide. 10. Photographic recording material according to one of claims 1 to 9, wherein the outermost layer contains at least one surfactant. 11. A photographic recording material according to any one of claims 1 to 10, wherein the difference in viscosity between the coating solution for forming the outermost layer and the solution for forming the layer adjacent to the outermost layer is in the range of ± 2·10⁻³ Pas (2 cp). 12. A photographic material according to any one of claims 1 to 11, wherein the average grain size of the silver halide emulsion grains contained in the silver halide color photographic light-sensitive material is 0.30 to 1.50 µm.