Solid developing tablet for silver halide photographic light-sensitive materials and its use

Abstract: A solid developing composition for a silver halide photographic light-sensitive material is disclosed, the composition containing an alkali agent and a developing agent and at least a part of the composition being in the form of granules, wherein the composition has a specific volume of 0.6 to 2.0 cm³/g and a moisture content of 0.1 to 15% by weight.

Description: Field of the Invention The invention relates to a solid developing tablet for a silver halide photographic light-sensitive material. The invention refers also to the use of the tablet for developing a silver halide photographic material. Background of the Invention EP-A-0 611 987 considered pursuant to Article 54 (3) EPC discloses a solid developing tablet obtained by compression-molding a solid developing composition comprising a color developing agent and an alkali agent both present in a granulated form. The tablet has a moisture content within the range of 0-3 wt%. JP-A-5 142 707 discloses a solid photographic processing agent having a moisture content of not more than 3 wt% and a specific volume of 0.16-2 cm3/g. A silver halide photographic light-sensitive material is usually processed using a black-and-white developer, a fixer, a color developer, a bleach, a bleach-fixer and a stabilizer to obtain an imagewise image. The components of the processing solutions used herein are packaged in plastic bottles for easy use and are in the form of concentrated solutions and are supplied as a processing solution kit to consumers. The consumers dilute the component solutions of the kit with water to prepare the processing solutions and use them as solutions for use (as starter solutions or replenisher solutions). Recently, in the photographic processing industry small-scaled developing store, so-called mini-labs, which process a photographic material using a small automatic processor, rapidly increased and the amount of the processing kits used also increased. The processing kit in concentrated solution form still requires much storage space. Further, the cost for transport is not low. The discarded plastic bottles increase year by year and should be recovered, however the recovering is difficult and therefore, development of a processing system in which waste plastics are reduced is demanded. Powder photographic processing agents are considered in order to reduce storage space, transport cost and the amount of the plastic waste. However, the powder agents produce loose powder when it is dissolved in water, and operators breathe in loose powder particles, resulting in health hazard. Further, other photographic solutions may be contaminated with the components of the loose powder and there occurs the possibility of other trouble in developing process. In response to these problems Japanese Patent O.P.I Publication Nos. 2-109042/1990 and 2-109043/1990 disclose a technique of using a granular mixture of photographic processing agents. Patent O.P.I Publication Nos. 5-119454/1993, 5-113646/1993 and 5-107698/1993 disclose a photographic processing system using a solid developing processing agent and a solid developing processing agent used therein. The above Japanese Patent O.P.I Publication No. 2-109042/1990 discloses a color developing agent which is a mixture of a granular anti-oxidant, a granular developing agent and a granular alkali-providing agent. The above Japanese Patent O.P.I Publication No. 2-109043/1990 discloses a color developing agent which is a mixture of a granular anti-oxidant, a granular developing agent and a granular alkali-providing agent, each having an average particle size of 150 µm or more and 80% of the granule falling within the deviation range of not more than ±150 µm. It is disclosed that the above photographic developing agent has unlimited durability and excellent solubility. The photographic developing agent described in the above references has a considerable storage stability, although not unlimited durability, and excellent solubility in laboratory experiments. However, when the photographic developing agent is manufactured in a factory during mass production, the agent having excellent storage stability and solubility can be sometimes obtained and sometimes not. Accordingly, there is a problem that the agent having stable properties cannot always be obtained. In order to solve the above problems, the inventors have tried to improve storage stability of a developing composition by granulating a developing agent and an alkali agent separately, however, there is the problem that deformation, oxidation and coloration of the composition occur. There is lowering of hardness or oxidation-coloration also in a developing composition molded in tablets. This gives doubt of deteriorated quality to consumers and this remains a problem in view of commercial value. It has been found that it is difficult to obtain a solid developing composition comprising a developing agent and an alkali agent without occurrence of coloration and losing commercial value for 2-3 years which is an effective period, even if any possible conventional methods are applied. The inventors have made a detailed study and have found that the specific volume and moisture content of the solid processing composition have much influence on the above problems. Summary of the Invention Accordingly, a first object of the invention is to provide a solid developing composition in the form of a tablet for a silver halide photographic light-sensitive material having a long storage stability. A second object of the invention is to provide a solid developing composition in the form of a tablet for a silver halide photographic light-sensitive material low in oxidation-coloration due to its hygroscopic property and high in commercial value. Another object will be apparent from the following description. Detailed Description of the Invention The above object is attained by the following subject of the invention: (1) A solid developing tablet for a silver halide photographic light-sensitive material, the tablet having a compressive breaking strength as measured after 24 hours storage at room temperature of 20 to 80 kg, wherein the tablet is obtained by compression-molding a composition containing a alkali agent giving pH of 8 or more and a color or black-and-white developing agent and at least a part of the composition being in the form of granules, wherein the composition has a specific volume of 0.6 to 2.0 cm 3 /g and a moisture content of 0.1 to 15 % by weight. Further embodiments of the invention are (2) The solid developing tablet of (1) above, wherein the alkali agent and the developing agent is present in a separate component part. (3) The solid developing tablet of (1) or (2) above, wherein a component containing at least one of the alkali agent and the developing agent is in the form of granules. (4) The solid developing tablet of (1), (2) or (3) above, wherein a component containing the alkali agent and a component containing the developing agent are in the form of granules. (5) The solid developing tablet of (1), (2), (3) or (4) above, wherein an average particle diameter of the granules is 150 to 1500 µm. The invention will be detailed below. The inventors have found the following by conducting experiments on a powder solid developing composition for a silver halide photographic light-sensitive material. When, in the solid developing composition for a silver halide photographic light-sensitive material comprising an alkali agent and a developing agent together, the moisture content is more than 15% by weight, the contact reaction between the alkali agent and developing agent occurs due to the moisture and the developing agent is oxidized or unstable. As a result it is difficult to maintain a constant developing agent content. On the other hand, when the moisture content is less less than 0.1% by weight, the difference between atmospheric humidity and humidity in the solid composition (humidity gradient) is large, atmospheric moisture penetrates the surface of the composition. In a similar manner as the above, the developing agent on the surface of the composition is subjected to oxidation, resulting in coloration of the composition and the content reduction of the color developing agent. Further, the strength of the solid composition is weakened. When the specific volume of the solid composition exceeds 2.0 cm 3 /g, the space in the composition is large and the composition absorbs more atmospheric moisture. It has been found, however, that the oxidation of the developing agent is promoted and the developing agent content of the composition is reduced. On the contrary, when the specific volume of the solid composition is less than 0.6 cm 3 /g, the coloration of the composition occurs during its storage although there is no problem as to moisture absorption. The inventors have made an extensive study on the above described experimental results and found that they can provide the solid developing tablet as defined above, having excellent storage stability and stable properties without an influence of atmospheric moisture during production, storage and usage. It has been found that the above solid developing composition for a silver halide photographic light-sensitive material, which is compression-molded into tablets, exhibits greatly improved storage stability as compared with the conventional one. This is because the initial moisture remaining in the tablets on compression-molding is considered to be controlled within the constant amount. The moisture content of the solid composition of the invention is 0.1 to 15% by weight. However, in view of the effects of the invention, the content is preferably 0.3 to 10% by weight, and most preferably 1 to 8% by weight. The specific volume of the fine particle solid developing composition is 0.6 to 2.0 cm 3 /g. However, in view of the effects of the invention, the specific volume is preferably 0.8 to 1.5 cm 3 /g. The moisture content of the solid composition referred to herein is calculated from the weight reduced after the composition is heated at 105°C to the constant weight which is measured with an electronic moisture meter available on the market. The specific volume of the solid composition referred to herein is calculated from the following equation: (Specific Volume) = Content(cm 3 )/Weight(g), wherein 10 g of the composition are placed in a 25 ml measuring cylinder and then the content is measured. In order to display the effects of the invention in the solid developing tablet of the invention, less contact between an alkali agent and a developing agent is preferable. In view of the above, at least one of them is preferably granules, since the effects of the invention are markedly displayed. It is more preferable that both agents are granules. This is because of another effect in which fine loose powder is reduced during storage as well as the above mentioned effects. As for the manufacturing method of the above described granules, it is possible to use any of the well-known methods such as a rolling granulation, an extrusion granulation, a compression granulation, a cracking granulation, a stirring granulation, a fluidized-layer granulation and water spray-drying granulation. The granules of the above described alkali agent and developing agent have an average particle diameter of preferably 150 to 1500 µm, and more preferably 300 to 1000 µm. The average particle diameter in the invention refers to an weight average particle diameter. The weight average particle diameter of the invention refers to a particle diameter at 50% by weight in a cumulative residue distribution plot obtained by screening. The above described solid developing composition is compression-molded into tablets. The tablets exhibit the effect of the invention markedly and the effective prevention of powder occurrence due during their storage. The solid processing tablet is produced by well known compressors. The compressors for producing the tablets include a hydraulic press machine, a single tableting machine, a rotary tableting machine and a bricketing machine can be used. The solid processing tablet may be in any form, but is preferably in the cylindrical form in view of producibility or processability On tableting a solid processing composition, lubricants or other additives may be added for facilitating tableting or for other objects. The solid processing tablet of the invention has a compressive breaking strength of 20 to 80 kg. The compressive breaking strength herein refers to a value measured by means of Speed Checker produced by Okada Seiko Co., Ltd. The developing agent of the invention is either a color developing agent or a black-and-white developing agent. The color developing agent is preferably a p-phenylene diamine type compound having a water-soluble group. In the p-phenylenediamine type compound having a water-soluble group at least one water-soluble group is positioned on the amino group or benzene nucleus of a p-phenylene diamine type compound. The typical water-soluble groups include preferably -(CH 2 ) n -CH 2 OH, -(CH 2 ) m -NHSO 2 -(CH 2 ) n -CH 3 , -(CH 2 ) m -O-(CH 2 ) n -CH 3 , -(CH 2 CH 2 O) n C m H 2m+1 (in which m and n are each an integer of not less than 0), -COOH group and -SO 3 H group. The example of the color developing agent preferably used in the invention includes (C-1) through (C-16) and 4-amino-3-methyl-N-(3-hydroxypropyl)aniline on pages 26 to 31 of Japanese Patent Application No. 2-203169/1990 (Japanese Patent O.P.I. Publication No. 4-86741/1992). The above color developing agents are usually used in the form of hydrochloride, sulfate or p-toluenesulfonic acid salt. Of these 4-amino-3-methyl-N-ethyl-N-(β-methanesulfonamidoethyl) aniline 3/2 sulfate monohydrate (CD-3) and 4-amino-3-methyl-N-(β-hydroxyethyl) aniline sulfate (CD-4) are preferable. The example of the black-and-white developing agent includes phenidone, hydroquinone, metol, 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone, 4,4-dimethyl-1-phenyl-3-pyrazolidone and hydroquinone monosulfonic acid. The alkali agent of the invention is a compound giving pH 8 or more in its aqueous solution. The preferable example includes sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, trisodium phosphate, tripotassium phosphate, disodium phosphate, dipotassium phosphate, sodium borate, potassium borate, sodium tetraborate (borax), potassium tetraborate, sodium hydroxide, potassium hydroxide and lithium hydroxide. Sodium carbonate, sodium bicarbonate, sodium borate and trisodium phosphate are preferable in view of moisture prevention, and sodium carbonate is especially preferable. The solid processing composition is in the form of tablets in attaining the objects of the invention. The solid-processing tablet herein referred to comprises an alkali agent and a developing agent, and may contain other components as powder. In the tablet of the invention the alkali agent and the developing agent both are especially preferably granules. Additives in the composition other than the alkali agent and the developing agent may be powder. The developing tablet of the invention may optionally contain a chelating agent, a development accelerating agent, a development inhibitor (halides), a fluorescent brightening agent or a preservative usually used in the developer. A solid preservative is preferably used in combination in the solid developing tablet of the invention, and granules of a mixture of a preservative and a developing agent are preferable. The preservative includes a sulfite (sodium sulfite or potassium sulfite), a bisulfite (sodium bisulfite or potassium bisulfite), a metabisulfite (sodium metabisulfite or potassium metabisulfite) and a hydroxylamine derivative. The hydroxylamine derivative includes a compound represented by the following Formula (I) wherein R 1 and R 2 independently represent a hydrogen atom, a substituted or unsubstituted alkyl, aryl or heterocyclic group or R 3 CO- wherein R 3 represents an alkyl group, an alkoxy group, an aryl group or an amino group, provided that R 1 and R 2 may combine to form a nitrogen containing heterocyclic ring. In Formula (I) the substituted alkyl group of R 1 and R 2 is preferably a substituted alkyl group having 1 to 3 cabon atoms, and may be the same or different. The substituent of the alkyl group includes a hydroxy group, a sulfo group, a phosphonic acid group, an alkoxy group, a carbamoyl group and a cyano group. The exemplified compound of Formula (I) will be given below. R 1 R 2 A-1 -H -H A-2 -H -CH 3 A-3 -CH 3 -CH 3 A-4 -H -C 2 H 5 A-5 -CH 3 -C 2 H 5 A-6 -C 2 H 5 -C 2 H 5 A-7 -C 3 H 7 (n) -C 3 H 7 (n) A-8 -C 3 H 7 (i) -C 3 H 7 (i) A-9 -C 4 H 9 (n) -C 4 H 9 (n) A-10 -C 4 H 9 (i) -C 4 H 9 (i) A-11 -C 4 H 9 (t) -C 4 H 9 (t) A-12 -CH 3 -CH 2 CH 2 COOH A-13 -CH 3 -CH 2 CH 2 SO 3 H A-14 -CH 3 -CH 2 COOH A-15 -CH 3 -CH 2 CH 2 PO 3 H 2 A-16 -H -CH 2 CH 2 SO 3 H A-17 -CH 2 CH 2 COOH -CH 2 CH 2 COOH A-18 -CH 2 CH 2 SO 3 H -CH 2 CH 2 SO 3 H A-19 -CH 2 COOH -CH 2 COOH A-20 -CH 2 CH 2 PO 3 H 2 -CH 2 CH 2 PO 3 H 2 A-21 -CH 2 CH 2 OH -CH 2 CH 2 OH A-22 -CH 3 -CH 2 CH 2 CONH 2 A-23 -CH 2 CH 2 CONH 2 -CH 2 CH 2 CONH 2 A-24 -CH 3 -CH 2 CH 2 OCH 3 A-25 -CH 2 CH 2 OCH 3 -CH 2 CH 2 OCH 3 A-26 -CH 3 -CH 2 CH 2 OH A-27 -CH 2 CH(CH 3 )COOH -CH 2 CH(CH 3 )COOH A-28 -CH 2 CH 2 CN -CH 2 CH 2 CN In the above compounds A-12 through A-20 and A-27 can be used in the form of an alkali metal salt (sodium, potassium or lithium salt). The compounds represented by Fomula (I) are usually used in free amine or in the form of hydrochloric acid, sulfate, p-toluenesulfonic acid, oxalic acid, phosphoric acid or acetic acid salt. The compounds represented by Fomula (I) are preferably solids in view of the objects of the invention. Of these A-1, A-6, A-17, A-18 and A-25 are especially preferable, and the examples will be given below. Examples The invention will be detailed in the following Examples, and is not limited thereto. Reference Example 1 A color developing composition in the form of granules was prepared according to the following procedures. Procedure (1-1) Through a speed mill available on the market were granulated 6000g of granules of color developing agent 4-amino-3-methyl-N-ethyl-N-(β-hydroxyethyl)aniline sulfate (hereinafter referred to as CD-4). The resulting granules were classified by a sieve, and the granules of an particle diameter less than 149 µm and the granules of an average particle diameter not less than 1410 µm (JIS) were removed to obtain granules (A). Procedure (1-2) In a hammer-mill available on the market 3500 g of hydroxylamine sulfate, 350 g of potassium bromide and 150 g of disodium 2-dihydroxybenzene-3,5-disulfonate monohydrate (hereinafter referred to Tiron) were pulverized to have an average particle size of 50 µm and mixed with 200 g of Pineflow (produced by Matsutani Chemical Co.), and the mixture was granulated for 7 minutes in a stirring granulator available on the market by adding 150 ml of water thereto. Thereafter, the granules were dried at 55°C for 3 hours and were classified in the same manner as in Procedure (1-1) to obtain granules (B). In the same manner as in Procedure (1-2) were pulverized 5800 g of sodium sulfite, 270 g of potassium carbonate and 2500 g of pentasodium diethylenetriaminepentaacetate. The resulting fine particles were mixed with 5500 g of polyethyleneglycol #6000 (produced by Nihon Ushi Co., Ltd.) and 7500 g of mannitol in a stirring granulator available on the market and were granulated by adding 1400 ml of water thereto in the same manner as in Procedure (1-2). Thereafter, the granules were dried at 55°C for 4 hours and were classified in the same manner as in Procedure (1-1) to obtain granules (C). (Preparation of Sample 1-1) The above obtained granules in Procedures (1-1) to (1-3) were mixed for 10 minutes at 25°C and at 50%RH through a cross rotary mixer available on the market to obtain Sample 1-1. Procedure (1-4) In the same manner as in Procedure (1-3) granules (D) were prepared, except that a part of potassium carbonate was changed to potassium carbonate 3/2 hydrate without changing the total mol number and granulation time, the addition of water and drying time were suitably adjusted. The adjustment of the amount of potassium carbonate 3/2 hydrate, the granulation time, the addition of water and the drying time were carried out to obtain a specific volume and moisture content shown in Table 1 in Samples 1-2 through 1-17. (Preparation of Samples 1-2 through 1-17) Samples 1-2 through 1-17 were prepared in the same manner as in Sample 1-1 using granules (A) prepared in Procedure (1-1), granules (B) prepared in Procedure (1-2) and granules (D) prepared in Procedure (1-4). The specific volume and moisture content of Samples 1-2 through 1-17 are shown in Table 1. The specific volume and moisture content were measured through the following method. (Specific Volume) In a 25 ml measuring cylinder were placed 10 g of Samples and the volume was measured. The specific volume was calculated from Equation (Specific Volume) = Content (ml)/Weight(g). (Moisture content) Samples were heated to the constant weight and the reduced weight was measured using an electronic moisture meter available on the market. The reduced weight corresponds to moisture content. In a Petri dish were placed 10 g of each of Samples 1-1 through 1-17 and stored for 4 hours at 25°C and 45%RH. Thereafter, hygroscopic property of the Samples was evaluated according to the following criteria. Evaluation Criteria A : No problem. B : Slight weight increase but no occurrence of wetness. C : Wetness occurs partly but no great problem. D : Wetness occurs in the whole due to moisture absorption. The results are shown in Table 1. In an aluminium package were placed 10 g of each of Samples 1-1 through 1-17, and tightly sealed and stored for 2 months at 50°C. Thereafter, the resulting Samples were evaluated for coloration according to the following criteria. Evaluation Criteria A : No coloration. B : Slight coloration but no problem. C : Partial coloration occurs but of no great problem. D : Coloration occurs in the whole. The results are shown in Table 1. Samples evaluated D in hygroscopic property or coloration are low in commercial value. Sample No. Specific Volume (cm 3 /g) Moisture Content (weight %) Hygroscopic Property Coloration after Storage 1-1 1.02 1.06 B B 1-2 0.54 1.12 B D 1-3 0.98 0.05 D C 1-4 0.61 1.12 B C 1-5 0.82 1.01 B B 1-6 1.23 1.08 B B 1-7 1.53 0.98 B B 1-8 1.98 1.00 C C 1-9 2.21 1.03 D D 1-10 1.01 0.11 C C 1-11 0.98 0.32 B-C B-C 1-12 0.96 2.03 B B 1-13 1.05 5.06 B B 1-14 1.02 8.21 B B 1-15 0.99 10.09 B B-C 1-16 1.01 14.89 B C 1-17 1.06 20.12 B D As is apparent from Table 1, the color developing composition having a specific volume and moisture content within the range of the invention enables to restrain its hygroscopic property on storage in an open system and its coloration on storage in a closed system. Reference Example 2 A color developing composition was prepared according to the following procedures. (Preparation of Sample 2-1) In a hammer-mill available on the market 6000 g of granules of CD-4, 3500 g of hydroxylamine sulfate, 350 g of potassium bromide, 150 g of Tiron and 200 g of Pineflow were pulverized to have an average particle size of not more than 100 µm and mixed with granules (D) of Reference Example 1 to obtain Sample 2-1. Granule (D) were prepared to give the specific volume and moisture content shown in Table 2. (Preparation of Sample 2-2) In a hammer-mill available on the market 3500 g of hydroxylamine sulfate, 150 g of Tiron, 5800 g of sodium sulfite, 35000 g of potassium carbonate and 2500 g of pentasodium diethylenetriaminepentaacetate, 5500 g of polyethyleneglycol #6000 and 7500 g of mannitol were pulverized to have an average particle size of not more than 100 µm and dried. Thereafter, the resulting powder was mixed with 5980 g of granules of CD-4 to obtain Sample 2-2. On Mixing, purverized potassium bromide was added to give the specific volume and moisture content shown in Table 2. (Preparation of Samples 2-3 and 2-4), Granules (A), (B) and (D) prepared in Reference Example 1 were mixed to obtain Samples 2-3 and 2-4. Granules (D) was prepared to give the specific volume and moisture content shown in Table 2. (Preparation of Sample 2-5) Granules (A), (B) and (D) prepared in Reference Example 1 and polyethyleneglycol #6000, which was pulverized in a hammer-mill available on the market to have an average particle size of not more than 100 µm, were mixed to obtain Samples 2-5. Granules (D) was prepared to give the specific volume and moisture content shown in Table 2. (Preparation of Sample 2-6) Procedure (2-1) In a hammer-mill CD-4 was pulverized and screened with a sieve having a 74 µm sieve mesh to obtain powder (A) minus sieve. Procedure (2-2) Potassium carbonate powder was prepared in the same manner as in Procedure (2-1) to obtain powder (E). Potassium carbonate 3/2 hydrate powder was prepared in the same manner as in Procedure (2-1) to obtain powder (F). Procedure (2-3) In the same manner as in Procedure (1-2), 5800 g of sodium sulfite and 2500 g of pentasodium diethylenetriaminepentaacetate were pulverized and the resulting fine powder was mixed with 5500 g of polyethylene glycol #6000 and 7500 g of mannitol in a mixer. The resulting mixture was granulated by spraying 500 ml of water and dried at 55°C for 4 hours and screened in the same manner as in Procedure (1-1) to obtain granules (G). (Preparation of Sample 2-6) Powder (A) of 5980 g, 21200 g of granules (G) and 4180 g of granules (B) prepared in Procedure (1-2) were mixed. The resulting mixture were further mixed with powder (E) and powder (F) to give the specific volume and moisture content shown in Table 2 and have a potassium content of 270 mol. (Preparation of Sample 2-7) Hydroxylamine sulfate of 3500 g, 350 g of potassium bromide, 150 g of Tyron, 200 g of Pineflow, 5800 g of sodium sulfite and 2500 g of pentasodium diethylenetriaminepentaacetate were individually pulverized and individually screened with a sieve having a 74 µm sieve mesh to obtain fine powders minus sieve. The resulting fine powders were mixed with powder (A), powder (E) and powder (F) to give the specific volume and moisture content shown in Table 2 and have a potassium content of 270 mol. Thus, Sample 2-7 was obtained. The specific volume and moisture content of Samples 2-1 through 2-7 are shown in Table 2. In the same manner as in Example 1 the hygroscopic property and coloration after storage were evaluated. The results are shown in Table 2. Sample No. Specific Volume (cm 3 /g) Moisture Content (weight %) Hygroscopic Property Coloration after Storage 2-1 1.01 1.03 B-C B 2-2 1.06 0.98 B-C B 2-3 1.02 1.00 B B 2-4 1.02 0.05 D C 2-5 0.99 0.99 B B 2-6 1.02 0.79 C C 2-7 1.01 1.00 C D As is apparent from Table 2, the color developing composition in which one of the alkali agent and the developing agent is in the form of granules is preferable and the color developing composition in which both alkali agent and developing agent are in the form of granules is more preferable. Reference Example 3 A mixture of Granules (A), (B) and (D) prepared in Reference Example 1 was pulverized in a speed-mill available on the market and sieved with screens having various meshes to obtain Samples 3-1 through 3-11. The weight average particle size of Samples 3-1 through 3-11, which was measured through sieves (according to JIS), were shown in Table 3. Granules (D) was prepared to give the specific volume and moisture content shown in Table 3. The specific volume and moisture content of Samples 3-1 through 3-11 are shown in Table 3. In the same manner as in Reference Example 1 the hygroscopic property and coloration after storage were evaluated. The results are shown in Table 3. The evaluation criteria were the same as in Reference Example 1. Sample No. Specific Volume (cm 3 /g) Moisture Content (weight %) Weight Average Particle Size (µm) Hygroscopic Property Coloration after Storage 3-1 0.98 0.20 100 C C 3-2 0.98 0.24 150 B-C B-C 3-3 1.00 0.21 300 B B 3-4 1.02 0.23 800 B B 3-5 0.97 0.22 1000 B B 3-6 1.01 0.23 1500 B B-C 3-7 0.99 0.19 2000 B C 3-8 0.50 2.01 800 B D 3-9 2.25 1.99 800 D D 3-10 1.02 0.04 800 D C 3-11 1.01 19.52 800 B D As is apparent from Table 3, the color developing composition having a specific volume and moisture content within the range of the invention enables to restrain its hygroscopic property on storage in an open system and its coloration on storage in a closed system. The color developing composition having an average weight particle size of 150 to 1500 µm exhibits markedly the effects of the invention. Example 1 Myristoyl-N-methyl-β-alanine sodium salt was added in an amount of 0.5% by weight to each of Samples 1-1 through 1-17 of Reference Example 1 and mixed for 10 minutes at 25°C and 50%RH using a mixer. The resulting mixture was tableted in an amount of 12 g per tablet making use of a tableting machine in which Clean Press Correct 18K manufactured by Kikusui Mfg. Works was modified to obtain a tablet having a diameter of 30 mm. Thus, tablets for color development, Samples 4-1 through 4-17 were obtained. The specific volume and moisture content in Table 4 are those of Samples 1-1 through 1-17. In the same manner as in Reference Example 1 the hygroscopic property and coloration after storage were evaluated. Further, in a aluminium package were placed Samples 4-1 through 4-17, and tightly sealed and stored for 24 hours at room temperature. Thereafter, the compressive breaking strength (hardness) of the resulting Samples was measured by means of Speed checker produced by Okada Seiko Co., Ltd. The results are shown in Table 4. The evaluation criteria were the same as in Reference Example 1. Sample No. Specific Volume (cm 3 /g) Moisture Content (weight %) Hygroscopic Property Coloration after Storage Hardness after Storage (kg) Remarks 4-1 1.02 1.06 A A 52.8 Invention 4-2 0.54 1.12 B D 30.4 Comparative 4-3 0.98 0.05 D C 20.4 Comparative 4-4 0.61 1.12 A B 46.8 Invention 4-5 0.82 1.01 A A 53.2 Invention 4-6 1.23 1.08 A A 55.3 Invention 4-7 1.53 0.98 A A 52.9 Invention 4-8 1.98 1.00 B B 47.5 Invention 4-9 2.21 1.03 D C 30.9 Comparative 4-10 1.01 0.11 C B 43.6 Invention 4-11 0.98 0.32 B A 47.4 Invention 4-12 0.96 2.03 A A 53.9 Invention 4-13 1.05 5.06 A A 58.2 Invention 4-14 1.02 8.21 A A 54.7 Invention 4-15 0.99 10.09 A B 49.5 Invention 4-16 1.01 14.89 B B 46.8 Invention 4-17 1.06 20.12 A D 9.3 Comparative As is apparent from Table 4, the color developing tablet having a specific volume and moisture content within the range of the invention enables to greatly restrain its hygroscopic property on storage and its coloration on storage. Reference Example 4 A color developing composition was prepared according to the following procedures to obtain granules for color developer. Procedure (5-1) Through a speed mill were further granulated 15000g of granules of color developing agent 4-amino-3-methyl-N-ethyl-N-(β-methanesulfonamidoethyl)aniline 3/2 sulfate monohydrate. The resulting granules were classified by a sieve having a mesh of 149 µm and a sieve having a mesh of 1410 µm (according to JIS Standard) to remove particles of larger and less size and to obtain Granules A'). Procedure (5-2) In a hammer-mill 8000 g of bis(sulfoethyl)hydroxylamine disodium salt, 16000 g of sodium p-toluenesulfonate and 2500 g of Tinopar (produced by Ciba Geigy Corp.) were pulverized to have an average particle size of 10 µm and mixed with 2500 g of Pineflow, and the mixture was granulated for 5 minutes in a stirring granulator available on the market by adding 2000 ml of water thereto. Thereafter, the resulting granules were dried at 60°C and were classified in the same manner as in Procedure (5-1) to remove particles of larger and less size and to obtain granules (B'). Procedure (5-3) In the same manner as in Procedure (5-2) were pulverized 33000 g of potassium carbonate, 370 g of sodium sulfite, 3300g of pentasodium diethylenetriaminepentaacetate, 14000 g of sodium p-toluenesulfonate and 3400g of lithium hydroxide monohydrate. The resulting fine particles were mixed with 6000 g of mannitol and 5000 g of polyethyleneglycol #4000 and were granulated by adding 3500 ml of water thereto in the same manner as in Procedure (5-2). Thereafter, the granules were dried at 60°C and were classified in the same manner as in Procedure (5-1) to remove particles of larger and less size and to obtain granules (C'). (Preparation of Sample 5-1) The granules (A') through (C') obtained in Procedures (5-1) to (5-3) were mixed for 10 minutes at 25°C and at 50%RH through a cross rotary mixer available on the market to obtain Sample 5-1. Procedure (5-4) In the same manner as in Procedure (5-3) granules (D') were prepared, except that a part of potassium carbonate was changed to potassium carbonate 3/2 hydrate without changing the total mol number, and granulation time, the addition of water and drying time were suitably adjusted. The adjustment of the amount of potassium carbonate 3/2 hydrate, the granulation time, the addition of water and the drying time were carried out to obtain a specific volume and moisture content shown in Table 5 in Samples 5-2 through 5-17. (Preparation of Samples 5-2 through 5-17) Samples 5-2 through 5-17 were prepared in the same manner as in Sample 5-1 using granules (A') prepared in Procedure (5-1), granules (B') prepared in Procedure (5-2) and granules (D') prepared in Procedure (5-4). The specific volume and moisture content of of Samples 5-2 through 5-17 were shown in Table 5. In the same manner as in Reference Example 1 the hygroscopic property and coloration after storage were evaluated. The results are shown in Table 5. The evaluation criteria were the same as in Reference Example 1. Sample No. Specific Volume (cm 3 /g) Moisture Content (weight %) Hygroscopic Property Coloration after Storage 5-1 1.02 1.41 B B 5-2 0.54 1.42 B D 5-3 1.01 0.05 D C 5-4 0.61 1.42 B C 5-5 0.80 1.44 B B 5-6 1.22 1.43 B B 5-7 1.50 1.39 B B 5-8 1.98 1.40 C C 5-9 2.21 1.42 D D 5-10 1.06 0.11 C C 5-11 1.05 0.32 B-C B-C 5-12 1.08 2.04 B B 5-13 1.03 5.07 B B 5-14 1.07 8.02 B B 5-15 1.04 10.03 B B-C 5-16 1.02 14.85 B C 5-17 1.06 20.01 B D As is apparent from Table 5, the color developing composition having a specific volume and moisture content within the range of the invention enables to restrain its hygroscopic property on storage in an open system and its coloration on storage in a closed system. Example 2 The tablets for color development, Samples 6-1 through 6-17 were prepared in the same manner as in Example 1 using Samples 5-1 through 5-17 in Reference Example 4. The specific volume and moisture content in Table 6 are those of Samples 5-1 through 5-17 (granules). In the same manner as in Reference Example 1 the hygroscopic property and coloration after storage were evaluated. Further, the compressive breaking strength (hardness) of the resulting Samples was measured in the same manner as in Example 1. The results are shown in Table 6. The evaluation criteria were the same as in Reference Example 1. Sample No. Specific Volume (cm 3 /g) Moisture Content (weight %) Hygroscopic Property Coloration after Storage Hardness after Storage (kg) Remarks 6-1 1.02 1.41 A A 54.9 Invention 6-2 0.54 1.42 B D 29.8 Comparative 6-3 1.01 0.05 D C 21.2 Comparative 6-4 0.61 1.42 B B 47.3 Invention 6-5 0.80 1.44 A A 52.9 Invention 6-6 1.22 1.43 A A 56.4 Invention 6-7 1.50 1.39 A A 54.6 Invention 6-8 1.98 1.40 B B 45.7 Invention 6-9 2.21 1.42 D C 32.6 Comparative 6-10 1.06 0.11 B B 46.1 Invention 6-11 1.05 0.32 B A 46.3 Invention 6-12 1.08 2.04 A A 54.7 Invention 6-13 1.03 5.07 A A 58.8 Invention 6-14 1.07 8.02 A A 53.5 Invention 6-15 1.04 10.03 A B 47.9 Invention 6-16 1.02 14.85 B B 45.4 Invention 6-17 1.06 20.01 A D 12.1 Comparative As is apparent from Table 6, the color developing tablet having a specific volume and moisture content within the range of the invention enables to greatly restrain its hygroscopic property on storage and its coloration on storage. Reference Example 5 Black-and-white developing composition in the form of granules was prepared through the following Procedures. Procedure (7-1) Developing composition Part A Hydroquinone 24.0 kg Methylhydroxymethylphenidone 0.88 kg 5-methylbenzotriazole 0.3 kg Diethylenetriaminepentaacetic acid 1.45 kg 1-phenyl-5-mercaptotetrazole 0.02 kg Boric acid 2.3 kg Potassium bromide 5.0 kg In a hammer-mill the above composition Part A was pulverized to have an average particle size of 50 µm and mixed in a mixer, and the mixture was granulated for 5 minutes in a stirring granulator by adding 1500 ml of water thereto. Thereafter, the granules were dried at 55°C for 3 hours and were classified in the same manner as in Procedure (1-1) to obtain granules (E). Procedure (7-2) Developing composition Part B Sodium sulfite 56.0 kg Potassium carbonate 26.4 kg Potassium hydroxide 8.8 kg In the same manner as in Procedure (7-1) was pulverized the above composition Part B and mixed. The resulting mixture was granulated in the same manner as in Procedure (7-1), except that 4000 ml of water were added thereto. Thereafter, the granules were dried at 55°C for 4 hours and were classified in the same manner as in Procedure (1-1) to obtain granules (F). (Preparation of Sample 7-1) The granules (E) through (F) obtained in Procedures (7-1) and (7-2) were mixed for 10 minutes at 25°C and at 50%RH through a cross rotary mixer available on the market to obtain Sample 7-1. Procedure (7-3) In the same manner as in Procedure (7-2) granules (G) were prepared, except that a part of potassium carbonate was changed to potassium carbonate 3/2 hydrate without changing the total mol number, and granulation time, the addition of water and drying time were suitably adjusted. The adjustment of the amount of potassium carbonate 3/2 hydrate, the granulation time, the addition of water and the drying time were carried out to obtain a specific volume and moisture content shown in Table 7 in Samples 7-2 through 7-16. (Preparation of Samples 7-2 through 7-16) Samples 7-2 through 7-16 were prepared in the same manner as in Sample 7-1 using granules (E) prepared in Procedure (7-1) and granules (F) prepared in Procedure (7-3). The specific volume and moisture content of of Samples 7-2 through 7-16 are shown in Table 7. In the same manner as in Reference Example 1 the hygroscopic property and coloration after storage were evaluated. The results are shown in Table 7. The evaluation criteria were the same as in Reference Example 1. Sample No. Specific Volume (cm 3 /g) Moisture Content (weight %) Hygroscopic Property Coloration after Storage 7-1 1.01 1.09 B B 7-2 0.52 1.14 B D 7-3 0.95 0.04 D C 7-4 0.63 1.15 B C 7-5 0.82 1.10 B B 7-6 1.52 0.98 B B 7-7 1.95 1.00 C C 7-8 2.25 1.05 D D 7-9 1.05 0.13 C C 7-10 0.95 0.35 B-C C 7-11 0.95 2.15 B B 7-12 1.08 5.13 B B 7-13 1.05 8.30 B B 7-14 1.00 10.10 B B-C 7-15 1.03 14.55 B C 7-16 1.08 20.42 B D As is apparent from Table 7, the black-and-white developing composition having a specific volume and moisture content within the range of the invention enables to restrain its hygroscopic property on storage in an open system and its coloration on storage in a closed system.

Claims: A solid developing tablet for a silver halide photographic light-sensitive material, the tablet having a compressive breaking strength as measured after 24 hours storage in a sealed aluminium package at room temperature of 20 to 80 kg, wherein the tablet is obtained by compression-molding a composition containing an alkali agent giving pH of 8 or more and a color or black-and-white developing agent and at least a part of the composition being in the form of granules, wherein the composition has a specific volume of 0.6 to 2.0 cm 3 /g and a moisture content of 0.1 to 15 % by weight. The solid developing tablet of claim 1, wherein at least one of the alkali agent and the developing agent is contained in the granules. The solid developing tablet of claim 2, wherein the alkali agent is contained in first granules and the developing agent is contained in second granules. The solid developing tablet of claim 1, wherein the granules have a weight average particle diameter of 150 to 1500 µm, wherein the weight average particle diameter refers to a particle diameter at 50 % by weight in a cumulative residue distribution plot obtained by screening. Use of the tablet of any of claims 1 to 4 for developing a silver halide photographic light-sensitive material.

Inventors: DEGUCHI TAKASHI, KUWAE KENJI, UEDA YUTAKA, DEGUCHI, TAKASHI, KUWAE, KENJI, UEDA, YUTAKA, DEGUCHI, TAKASHI, C/O KONICA CORPORATION, KUWAE, KENJI, C/O KONICA CORPORATION, UEDA, YUTAKA, C/O KONICA CORPORATION
Applicants: KONISHIROKU PHOTO IND, KONICA CORPORATION
Application year: 1995
Main classification: G03C7
IPC codes: G03C5, G03C7