SILVER HALIDE PHOTOGRAPHIC MATERIAL

Abstract: A silver halide photographic material is disclosed which comprises a support and a hydrophilic colloidal layer thereon containing a low molecular weight polymer having acrylic acid and/or methacrylic acid units or a salt thereof.

Description: SILVER HALIDE PHOTOGRAPHIC MATERIAL The present invention relates to an improved silver halide photographic material. As is well known to those skilled in the art, the covering power of silver in photosensitive silver halide emulsion layers of a silver halide photographic material is defined by the ratio of the optical density of the developed photographic material to the amount of silver developed per unit area. If silver covering power is improved, then higher density can be obtained from a coating with the same amount of silver or a smaller amount of silver can be used to obtain the same density. For these reasons, various proposals have been made in order to augment the covering power of silver. For example, a method is known in which certain water soluble polymers are added to a silver halide photosensitive emulsion including polysaccharides such as dextrin, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyvinyl alcohol and derivatives thereof. In augmenting silver covering power by adding said water soluble polymer, however, it is necessary to add a considerable amount, say several tens percent to the weight of a binder such as gelatin. Accordingly, the physical properties of the hydrophilic colloidal layer coat deteriorates because of the addition. As a result, it can be considered that the covering power is augmented because, in effect, the developed silver is more dispersed. In photographic emulsions to which such water soluble polymers has been added, there has been the disadvantage that the viscosity has fluctuated considerably or that the effect of a hardening agent to harden the hydrophilic colloidal layer is reduced. In the case of photographic materials for radiographic use or for the graphic arts, for example, and in the current common situation where a roller type automatic processor is used in the developing process, the inferior physical properties of a hydrophilic colloidal layer coat will give rise to the high frequency of "pressure fogs" caused by the pressure of the conveyer roller of the automatic processor in the development operation and will seriously reduce the commercial value of the photographic material, it is therefore necessary to develop a means of improving the silver covering power without such accompanying disadvantages. As a result of various studies of ways of augmentin#g the silver covering power without accompanying deterioration of the physical properties of the coat, we have discovered, according to the present invention, a silver halide photographic material comprising a support with a hydrophilic colloidal layer thereon containing a low molecular weight polymer having acrylic acid or methacrylic acid as a monomeric unit. In this specification, the term "low molecular weight", preferably means a number average molecular weight (i.e., mn) of not more than 20 000 and especially not more than 10 000 mn. The low molecular weight polymer used in this invention is a homopolymer or a copolymer having acrylic or methacrylic acid as a monomeric unit. A copolymer used in this invention preferably contains not less than 20%, and more preferably not less than 50%, by weight of acrylic or methacrylic acid as units. Such copolymers contain, for example, vinyl monomer units or other kinds of monomeric units, capable of copolymerizing with acrylic or methacrylic acid monomer, such as acrylamide, acrylate ester, styrene or maleic acid. It is not disadvantageous to use a salt of acrylic or methacrylic acid such as an alkaline metal or ammonium salt The amount of polymer added is suitably 1 - 80% by weight, and preferably 3 - 40% by weight of the amount of binder, such as gelatin, contained in a photographic construction layer (i.e., a hydrophilic colloidal layer). Suitable vinyl monomers which can be used to obtain the copolymers which can be used in this invention include styrene and the derivatives thereof, such as styrene itself, o-methyl styrene, m-methyl styrene, pmethyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, p-n- butyl styrene, p-tert-butyl styrene, p-n-hexyl styrene, p-n-octyl styrene, p-n-nonyl styrene, p-n-decyl styrene, p-n-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene and 3,4-dichloro styrene; an ethylenically unsaturated monolefin such as ethylene, propylene, butylene and isobutylene; a vinyl halide such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; a vinyl ester such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate, an a-methylene aliphatic ester such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methyl chloracrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate: an acrylic or methacrylic acid derivative such as acrylonitrile, methacrylonitrile and acrylamide; a vinyl ether such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; a vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; an N-vinyl compound such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, and N-vinyl pyrrolidone; and a vinyl naphthalene. Various polymerization methods can be used to obtain the polymers such as suspension polymerization, solution polymerization, emulsion polymerization and block polymerization; solution polymerization is preferably used. The following are some concrete examples of the polymers which can be used. In the following examples, the amounts quoted are percentages by weight. (Exemplified polymers ] EMI4.1 EMI5.1 EMI6.1 EMI7.1 Some typical synthesis Examples of the polymers are now given. Synthesis Example (1) [ Synthesis Example of Exemplified Polymer (1)g Acrylic acid (30 g) was dissolved in 100 ml of dioxane and 3 g of azobisisobutylonitrile were added thereto: the solution thus obtained was poured into a pressure bottle and was then polymerized for 15 hours at a temperature of 70 C. After cooling said polymer solution, it was added dropwise with agitation into 3 1 of ethylether; decantation was repeated three times with agitation, and the polymer deposited was then vacuum dried up; 27 g of the desired product were thus obtained. When the product was measured for its molecular weight by the vapor pressure equilibrium method, it was found to be 4 500. Synthesis Example (2) synthesis Example of Exemplified Polymer (3 There were put 50 g of methacrylic acid, 300 ml of methyl alcohol and 3 g of lauroyl peroxide into a flask of 500 ml capacity and then heated.and agitated continuously under a nitrogen atmosphere for 10 hours at a temperature of 8000. The polymer solution thus obtained. was poured into 5 1 of n-hexane after the solution was cooled, and the polymer thus deposited was then vacuum dried up: 43 g of the powdered desired product were thus obtained. When the product was measured for its molecular weight using an osmotic pressure method, it was found to be 7 500. Synthesis Example (3) synthesis Example of Exemplified Polymer (71 There were put 20 g of acrylic acid, 30 g of acrylamide, 200 ml of water, 300 ml of ethyl alcohol, 2 g of azobisisobutylonitrile and 0.5 g of dodecyl mercaptan into a flask of one liter capacity, and the solution obtained was heated and agitated continuously, under a nitrogen atmosphere, for seven hours at 700C and was then cooled, and the polymer solution thus obtained was added dropwise to 5 1 of tetrahydrofuran; the deposited polymer was vacuum dried up, at 80 C, and, thus, 40 g of the desired product was obtained. When the molecular weight thereof was measured, it was found to be 18 000. Synthesis Example (4) [ Synthesis Example of Exemplified Polymer (140 This was carried out as in Synthesis Example (3) with the exception that 40 g of methacrylic acid, 10 g of methyl acrylate, 300 ml of ethyl alcohol, 300 ml of water, 5 g of azobisisobutylonitrile and 1 g of dodecyl mercaptan were used in this example. The molecular weight of the product, measured by a vapor pressure equilibrium method, was found to be 13 000. As for the layers which can comprise the polymers used in this invention, a silver halide emulsion layer is preferred but, besides this, the other photographic constituent layers contiguous to said silver halide emulsion layer may also be used; it is also possible to incorporate said polymer in a plurality of layers at the same time. It is well known that polyacrylic acid and the like having high molecular weight are effective for improving covering power, similar to the case with other water-soluble polymers. As illustrated below in an example, however, such a conventional polyacrylic acid and the like, similar to the other water-soluble polymers, causes the physical properties of a hydrophilic colloidal layer coat to deteriorate with the occurrence of pressure fogs during development when an automatic processor is used; further, the covering power improvements are less than those of the other water-soluble polymers such as polyvinyl pyrrolidone (i.e., PVP), In contrast, using the polymers in this invention, as illustrated hereafter in an example, not only is no pressure fog observed but also there is an excellent improvement in the covering power. We -have been amazed to discover these results. We believe the effect of the use of the polymers used in this invention must be different from results caused by density variations in the drying state of the developed photographic material. With respect to the phenomenon that the optical density of a silver halide photographic material is decreased by drying after development, there has been a report by BLAKE and MEERKAMPER in Journal of Photographic Science, 1961, Vol 9, pp 14 - 25. The decrease of said density caused in the drying process results in a decrease of covering power of the developed silver: therefore, in order to improve such covering power it is desirable that the decrease in density should be less. Silver halide photographic materials incorporated with the specified polymers causes a very small decrease in the density on drying, as compared to the case of a high molecular weight polyacrylic acid or the other water-soluble polymers. That is to say, it may be that the effects on the covering power improvements when using other water-soluble polymers come from the developed silver spreading which results from the physical property deterioration of the hydrophilic colloidal layer coat, while it may be when using a polymer as, specified for this invention, that such effects do not result from the physical property deterioration of the hydrophilic colloidal layer coat but from a smaller decrease in density during drying as a result of enervating the drying shrinkage force of a binder such as gelatin in the hydrophilic colloidal layer. Various kinds of silver halide may be used in the silver halide emulsion layer to be used in the invention. For example, silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide and silver iodide may be used. There is no limitation on the crystal forms, crystal structures, grain diameters, grain diameter distributions and the like of the silver halide grains. For example, the crystal form may be either cubic, octahedral, twin or regular crystal form and may further be either cubo-octahedral or the so-called potato-like or spherical crystal form. Crystal structure may be either uniform, different between outside and inside, a layer-like structure, or joined to each different silver halide by epitaxial joining. Still further such structure may be the one forming a latent image mainly on the surface thereof or may be one forming such latent image inside. The present invention brings about particularly remarkable effects on a silver halide black-and-white photographic material of which the ultimate image forming element is silver grains or filaments; it is also capable of inhibiting the optical density variations of not only a gelatin-silver halide photographic material but also an image-forming material containing both a hydrophilic binder having a shrinkage power which influences an image forming element held inside said material and an image forming element which is affected by such shrinkage power. There is no limitation on the processes for preparing a silver halide emulsion of the invention, so that any process may be used. For example, either a single-jet process, double-jet process, a controlled double-jet process, an ammonia process, neutral process or acid process may be used. Gelatin is preferable to serve as a binder for the silver halide emulsion layer or other hydrophilic colloidal layer of the invention; in addition other hydrophilic colloids may also be used in accordance with the desired use. For example, it is possible to use a gelatin derivative, casein, a cellulose derivative, or a polysaccharide such as dextrin, polyvinyl alcohol, a vinyl maleic acid copolymer, poly-N-vinyl pyrrolidoneor an acrylamide copolymer. A silver halide emulsion to be used in the present invention may be sensitized by a usual chemical sensitization, such as a sulphur sensitization using sodium thiosulphate, allyl thiocarbamide, thiourea or allyl thiocyanate; or a noble metal sensitization in which potassium chloroplatinate, ammonium chloropalladium or ammonium chlororuthenium, rhodium, iridium or platinum can be used. It is also possible to sensitize said emulsion using a combination of such noble metal salt with a sulphur sensitizer and again in combination with ammonium thiocyanate serving as an assistant. Further, when using selenium sensitization processes, it is possible to sensitize said emulsion using, for example, selenourea, N,N-dimethyl selenourea or N-dimethyl selenourea as for reduction sensitization processes, it is possible to use a tin salt, a polyamine or a quaternary ammonium salt, for example. Also, it is possible to use a sensitizing process using a polyalkylene oxide compound or a process using a thioether. In a silver halide emulsion to be used in the invention the desired photosensitive wavelength range can be sensitized by making use of sensitizing dye. As for such sensitizing dyes, various kinds may be used and it is possible to combine two or more of them. Dyes advantageously used include methine dyes such as cyanine, hemicyanine, rhodacyanine, merocyanine, oxonol, hemioxonol or styryl dyes. Sensitizing dyes are effective in the invention, examples of which have been described in US Patents Nos 2 213 995, 2 503 776 and 2 945 763; (West) German Patents Nos 929 080 and 2 049 967: Japanese Patent Applications Nos 13821/1968, 32753/1969, 18106/1971, 8741/1972, and 37443/1972; and Japanese Patent Patent Open to Public Inspection No 89722/1973; as for the principal dyes, reference can be made to Japanese Patent Publication Open to Public Inspection No 137134/1978. The silver halide emulsion to be used in the present invention can be applied with a stabilizer and an antifoggant such as those disclosed in US Patents Nos 2 444 607; 2 716 062, 3 512 982 and 3 342 596; (West) German Patents Nos 1 189 380, and 2 058 626; Japanese Patent Publications Nos 4133/1968 and 2825/1964; and Japanese Patent Publication Open to Public Inspection Nos 22626/1975 and 25218/1975; particularly preferred compounds are 4-hydroxy-6-methyl-1 , 3, 3a, 7-tetrazaindene, 4-hydroxy-cyclopentano [ f ] -1,3,3a,7-tetrazaindene or an ester gallate (e.g., isoamyl gallate, dodecyl gallate, propyl gallate or sodium gallate); a mercaptan (e.g., l-phenyl-5-mercapto-tetrazole or 2-mercaptobenzothiazole): a benzotriazole (e.g., 5-bromobenzotriazole or 4-methylbenzotriazole): a benzoimidazole (e.g., 6-nitrobenzoimidazole); or a resolsinole. In a silver halide photographic material of this invention, a photographic hardening agent usually used in the coating solution of said material can be used, for example an aldehyde, an aziridine, an isoxazole, an epoxy compound, a vinyl sul fone, an acryloyl compound, a carbodimide, a maleimide, an acetylene, an ester methanesulfonate, a triazine or a macromolecular type hardening agent. As for the thickening agents, those described in US Patent No 3 767 410 and Belgian Patent No 558 143 and as for gelatin plasticizing agents, a polyol or a latex may be used without difficulty. Further, as for matting agents which can be used, those described in British Patent No 1 221 980 may be mentioned, and for gelatin derivatives which can be used, phenylcarbamyl gelatin, acylated gelatin, phthalated gelatin or those in which a gelatin is graft-polymerized with a polymerizable monomer having an ethylene group such as styrene acrylate, an ester acrylate, methacrylic acid or an ester methacrylate may be mentioned; said hydrophilic colloids may be used either in a layer containing silver halide or in a layer not containing silver halide such as a protective layer, an interlayer, a filter layer or other constitutional layer of a photographic material. In the various layers of the silver halide photographic material to which the invention relates, a coating assistant such as a saponin or sulfosuccinic acid type surface-active agent and an anionic surfaceactive agent, can be used. When the invention is applied to a color photographic material, various couplers may be used, for example yellow couplers such as an open-chain ketomethylene type coupler: magenta couplers such as pyrazolone, pyrazolotriazole, pyrazolinobenzimidazole and imidazolone compounds; and cyan couplers such as phenol and naphthol compounds. There may also be used a colored magenta coupler, a colored cyan coupler or a developing inhibitor releasing type coupler, a developing inhibitor releasing substance, a Weiss coupler or a competing coupler for example. Again, an ultra-violet absorbing agent, a fluorescent whitening agent, an image stabilizing agent, an anti-oxidizing agent, a lubricating agent, a metallic ion blocking agent or an emulsification dispersing agent, for example, can be used. The silver halide photographic materials of this invention may have the following layers, in addition to one or more silver halide emulsion layers; a protective layer, an interlayer, a filter layer, an antihalation layer, a subbing layer, an irradiation protective layer or a backing layer; suitable supports which can be used include a baryta paper, a polyethylene coated paper, a polypropylene synthetic paper, a glass plate, cellulose acetate, cellulose nitrate, polyvinyl acetal, polypropylene, a polyester film such as polyethylene terephthalate, a polyamide film, a polycarbonate film or a styrene film. These supports are suitably selected in accordance with the usage of the silver halide photographic material. The developing solutions which can be used for developing the silver halide photographic materials of this invention may be of the type ordinarily used; examples of suitable developers include hydroquinone, N-methyl-p-aminophenol, l-phenyl-3-pyrazolidone or paraphenylenediamine, singly or in combination. Also, in such developing solutions there can be used, as occasion requires, an alkaline agent such as sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide or sodium metaborate or an alkanol; a preservative such as sodium sulfite, potassium sulfite, sodium bisulfite, potassium pyrosulfite, formaldehyde or sodium hydrogensulfite addition products; a development foggant such as an azole, e.g., 5-nitrobenzoimidazole, 5-methylbenzotriazole, 8-nitrobenzotriazole or l-phenyl-5-mercaptotetrazole: and a hardening agent such as the well known aldehyde compounds for hardening gelatin and other macromolecular substances. Preferable aldehydes include a dialdehyde such as glutaric aldehyde or maleic aldehyde or a bisulfite thereof. Again, in such developing solutions there can be used,as occasion demands, an antioxidizing agent such as 3,6-dihydroxypyridazine, a polyamine; a polyalkyleneoxide compound; an alkylene glycol; or an alcohol such as methyl alcohol: an organic solvent such as dimethyl formamide, a cellosolve (ethylene glycol monoether) or benzyl alcohol; or ascorbic acid. Again; a chelating agent, a pH regulating agent or a buffer, for example, can be used. Developing time varies according to the nature of the developing solution, the developing temperature, the nature of the photosensitive material; however, a suitable time is normally about five minutes or longer, or about five seconds but not longer than one minute; development can be made by means of a tray type or a roller conveyor type automatic processor. The silver halide photographic materials of this invention can be processed by various processes depending on the nature of the photosensitive material; for example, in a black-and-white negative type photosensitive material the processing steps are as follows: Developing --? Fixing i Washing Drying, while in a color negative type photosensitive material the steps are as follows: Color-developing# Washing- > Bleaching b Washing ; Fixing # Washing # Stabilizing. Various types of silver halide photographic material can be provided by the present invention, for example, a black-and-white photosensitive material for general use, a radiosensitive material, a color photosensitive material, a photosensitive material for printing use, a photosensitive material for reproduction use, a photosensitive material for diffusion transfer use, a photosensitive material for silver dye bleaching process use or a photosensitive material for special use. The following Examples further illustrate the present invention. EXAMPLE 1 Cubic silver halide-gelatin emulsion (1 kg) which had been chemically sensitized using sodium thiosulfate and sodium chloroaurate (whose silver iodide content was 2 mol % and the average grain diameter was 1.2 #) was added to 10 ml of a 1# aqueous solution of 4-hydroxy-6-methyl-113,3a17-tetrazaindene1 30 ml of 10% aqueous solution of saponin and 3 ml of 3 aqueous solution of formalin (this emulsion contains 80 g of gelatin per mol of silver halide). The emulsion thus prepared was divided into eleven portions, and the polymers and copolymers shown in the following Table 1 were made up as aqueous solutions and added to the portions of said emulsion, the pH values adjusted with 5% aqueous solution of NaOH, and then coated onto a blue coloured polyethylene terephthalate support; thus, each of the samples(No. 1 - 11) was prepared. The samples thus prepared were exposed to white light by means of Sensitometer KS-1 Model (mfd. by Konishiroku Photo Ind. Co., Ltd.) in conformity with the procedure provided under the JIS, and developed in a tray, fixed, washed, taken out and measured for density when they were still wet, and when dried. After they were dried, measurements were made for the fog, sensitivity and maximum density of each sample using ordinary sensitometry. The density of every sample in the dry state is represented by a percentage of that of the same sample in the wet state, in order to obtain an index for the density variation of the samples. The amount of the developed silver of each sample in the maximum density area was measured by fluorescence X-ray analysis and the density value was divided by the value for the amount of silver to obtain a value for the covering power. The results obtained are shown in Table 1 below, wherein the sensitivity of each sample indicates the value relative to the sensitivity of Sample No. 1 of which the value is regarded as 100. The developing solution used was Developer tI ] which was composed as follows, and the processing conditions were: temperature - 200C and time - 4 min. 30 sec. Developing Solution CIJ Sodium sulfite 70 g Hydroquinone 10 g Sodium carbonate, anhydrous 30 g l-phenyl-3-pyrazolidone 0.35 g Potassium bromide 4 g Add water to make 1 litre As can be seen from the following Table 1, the polymers used in this invention reduce the density reduction and also improve the covering power, relative to sodium polyacrylate having a high molecular weight. Table 1 EMI20.1 <tb> Amount <SEP> Sensi- <SEP> Covering <SEP> Density <tb> Sample <SEP> Polymer <SEP> Added <SEP> Fog <SEP> tivity <SEP> C <SEP> power <SEP> variation <tb> <SEP> No. <SEP> molecularwt. <SEP> g/gelatin <SEP> Fog <SEP> state <SEP> ower <SEP> in <tb> <SEP> 10g] <SEP> [dmê/g] <SEP> state <SEP> [%] <SEP> <tb> <SEP> 1 <SEP> Nil <SEP> - <SEP> 0.03 <SEP> 100 <SEP> 40.2 <SEP> - <SEP> 10.8 <tb> <SEP> Exemplified <SEP> <tb> <SEP> 2 <SEP> Example <SEP> (1) <SEP> 1 <SEP> 0.03 <SEP> 100 <SEP> 44.8 <SEP> - <SEP> 0.2 <tb> <SEP> 4500 ] <SEP> <tb> <SEP> 3 <SEP> " <SEP> 2 <SEP> 0.03 <SEP> 99 <SEP> 45.3 <SEP> + <SEP> 1.1 <tb> <SEP> 4 <SEP> I1 <SEP> 4 <SEP> 0.03 <SEP> <SEP> 102 <SEP> --------- <SEP> ---------- <SEP> 46.3 <SEP> + <SEP> 4.1 <tb> <SEP> 5 <SEP> " <SEP> (3) <SEP> 1 <SEP> 0.03 <SEP> 101 <SEP> 40.0 <SEP> - <SEP> 0.3 <tb> <SEP> 5 <SEP> (3) <SEP> 0.03 <SEP> 101 <SEP> 40.0 <SEP> - <SEP> 0.3 <tb> <SEP> [7500] <SEP> 1 <tb> <SEP> 6 <SEP> " <SEP> 2 <SEP> 0.03 <SEP> 102 <SEP> 45.0 <SEP> + <SEP> 0.8 <tb> <SEP> 7 <SEP> [ <SEP> " <SEP> (7) <SEP> 1 <SEP> 0.03 <SEP> 98 <SEP> 44.3 <SEP> - <SEP> 1.3 <tb> <SEP> 18000 ] <tb> <SEP> 8 <SEP> <SEP> " <SEP> (14) <SEP> <SEP> 1 <SEP> 0.03 <SEP> 101 <SEP> 44.5 <SEP> - <SEP> 0.9 <SEP> <tb> <SEP> Sodium <tb> <SEP> 9 <SEP> polyacrylate <SEP> 1 <SEP> 0.03 <SEP> 99 <SEP> 40. <SEP> 7 <SEP> <SEP> - <SEP> 9.9 <tb> <SEP> [30000] <tb> <SEP> 10 <SEP> .. <SEP> 1 <SEP> 4 <SEP> 0.04 <SEP> 100 <SEP> 41.5 <SEP> - <SEP> 10.1 <SEP> <tb> <SEP> 11 <SEP> 170000 ] <SEP> <SEP> 1 <SEP> 0.04 <SEP> 98 <SEP> 41.0 <SEP> - <SEP> 11.2 <SEP> <tb> EXAMPLE 2 An emulsion prepared in the same manner as in Example 1 was divided into six parts and the compounds shown in the following Table 2 were respectively added to each of the parts; each of the mixtures and a protective layer material were coated over a support made of polyethylene terephthalate film; thus the samples (No. 12 - 17) were prepared in the same manner as in Example 1. Each of the samples was developed by Developing Solution CIJ in the same manner as in Example 1 and then the density variations and the covering powers in the dry state were measured. The development of each sample was made using a roller type automatic processor performing a series of processing steps: Developing - Fixing Washing - Drying; the degree of pressure fog produced was examined. The following is the formula of Developing Solution [ 113 that was used in the processing with said automatic processor: Developing Solution CIII Sodium sulfite, anhydrous 70 g Hydroquinone 10 g Boric acid, anhydrous 1 g Sodium carbonate (monohydride) 20 g l-phenyl-1,3-pyrazolidone 0.35 g Sodium hydroxide 5 g 5-methylbenzotriazole 0.05 g Potassium bromide 5 g Glutaric aldehyde hydrogensulfite 15 g Glacial acetic acid 8 g Add water to make 1 litre The results obtained therefrom are shown in the following Table 2. The degree of pressure fogs caused by the automatic processor are represented by the mark EMI21.1 which indicated no fog caused, the mark A which indicate only a little fog caused and the mark X that indicates considerable fog caused. As is apparent from the following Table 2, the polymers used in this invention give excellent results as regards covering power, density variation in the dry state and the degree of pressure fog. Table 2 EMI22.1 <tb> <SEP> Amount <SEP> Covering <SEP> Density <SEP> Degree <SEP> of <tb> Sample <SEP> Polymer <SEP> Added <SEP> Coveringvariation <tb> <SEP> 1: <SEP> 2 <SEP> in <SEP> gelatindry <SEP> Pressure <tb> <SEP> No. <SEP> Molecular <SEP> Wt. <SEP> Ig/gelatinPower <SEP> state <SEP> ### <SEP> Fog <tb> <SEP> 10 <SEP> g ] <SEP> fdm <SEP> stave/gJ <tb> <SEP> 12 <SEP> Nil <SEP> 40.1 <SEP> - <SEP> 10.7 <SEP> O <tb> <SEP> 10.7 <SEP> ¯ <tb> <SEP> Exemplified <tb> <SEP> 13 <SEP> Example <SEP> (1) <SEP> 1 <SEP> 44.8 <SEP> - <SEP> 0.3 <SEP> 0 <tb> <SEP> [ 4500 ] <tb> <SEP> Sodium <tb> <SEP> 14 <SEP> polyacrylate <SEP> 1 <SEP> 40.6 <SEP> - <SEP> 9.7 <SEP> A <tb> <SEP> [ 30000 ] <tb> <SEP> Polyvinyl <tb> <SEP> 15 <SEP> pyrolidone <SEP> 1 <SEP> 42.0 <SEP> - <SEP> 10.4 <SEP> x <tb> <SEP> K <SEP> K30 <tb> <SEP> 16 <SEP> Polyacrylamide <SEP> t <SEP> OS <SEP> 34.2 <SEP> - <SEP> 15.2 <SEP> X <tb> <SEP> [ 700000 ] <tb> <SEP> Polyethylene <tb> <SEP> 17 <SEP> glycol <SEP> 1 <SEP> 38.1 <SEP> - <SEP> 10.5 <SEP> A <tb>

Claims: CLAIMS 1. A silver halide photographic material comprising a support and a hydrophilic colloidal layer thereon containing a low molecular weight polymer having acrylic acid and/or methacrylic acid units or a salt thereof. 2. A silver halide photographic material according to claim 1, wherein the hydrophilic colloidal layer is a light-sensitive silver halide emulsion layer. 3. A silver halide photographic material according to claim 1, wherein the hydrophilic colloidal layer is a layer adjacent a light-sensitive silver halide emulsion layer. 4. A silver halide photographic material according to any one of claims 1 to 3, wherein the low molecular weight polymer has a number average molecular weight not exceeding 20 000. 5. A silver halide photographic material according to claim 4, wherein the low molecular weight polymer has a number average molecular weight not exceeding 10 000. 6. A silver halide photographic material according to any one of claims 1 to 5,wherein the low molecular weight polymer is a homopolymer having acrylic acid or methacrylic acid units. 7. A silver halide photographic material according to any one of claims 1 to 5,wherein the low molecular weight polymer is a copolymer having acrylic acid or methacrylic acid units. 8. A silver halide photographic material according to claim 7, wherein the copolymer contains not less than 20% by weight of acrylic acid or methacrylic acid units. 9. A silver halide photographic material according to claim 7 or 8, wherein the copolymer comprises units of a vinyl monomer. 10. A silver halide photographic material according to any one of claims 1 to 9, wherein the silver halide photographic material is a silver halide black-and-white photographic material.

Inventors: IWATA, MASATOSHI, KINOSHITA, SHUICHI, KOITABASCHI, TAKEO
Applicants: KONISHIROKU PHOTO INDUSTRY CO. LTD.
Application year: 1982
Main classification: G03C1
IPC codes: G03C1