JPS587983B2 - Insatsuyoushashingenbannogenzouzai - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an infectious developer containing hydroquinone as a main component, and more specifically to a developer for printing photographic plates containing a compound represented by the following general formula. The aim is to improve photographic properties with respect to processing, especially with respect to halftone quality.

General formula (wherein R1 is hydrogen, alkyl group, allyl group, aralkyl group, cycloalkyl group, ami7 group, acylamino group, carbamoyl group, halogen, carboxy group, carboalkoxy group, heterocyclic residue, R2 is hydrogen, Indicates an alkyl group, an allyl group, an aralkyl group, a cycloalkyl group, and a heterocyclic residue.

) Printing photographs M, which generally consist of line drawings or halftone images, use high-contrast squirrel-shaped silver halide photosensitive materials.
It is obtained by developing with a high-contrast developer called an infectious developer, which uses hydroquinone as a developing agent and has a low concentration of free sulfite ions.

Unlike ordinary developing solutions with a high concentration of sulfite ions, the developing solution with a low sulfite ion concentration and hydroquinone as a developing agent loses its developing properties due to the oxidation of hydroquinone over time after the developer is prepared. However, it has the disadvantage that photographic properties, particularly halftone dot performance, deteriorate.

Conventionally known contagious developing solutions have these drawbacks and are not fully satisfactory from a practical point of view, and the most important properties of contagious developing solutions, which are improvement of halftone dot quality and definiteness regarding the photographic properties of the solution itself, are lacking. It has been coveted.

According to the present invention, it has been found that as a result of incorporating the compound represented by the above general formula into a conventional infectious developer, the deterioration of the infectious developability over time is reduced and, in other words, the deterioration of halftone dot performance over time is prevented.

The infectious developer according to the present invention is mainly composed of a dihydroxybenzene-based developing agent such as hydroquinone, halogen-substituted hydroquinone, or alkyl-substituted hydroquinone, alone or in combination.

This developer is further added with a compound having a carbonyl (>C=O) and a soluble alkali bisulfite salt, such as an adduct of an aldehyde sulfite alkali salt, an adduct of a soluble sulfite with cyclohexane or acetone. A preservative for a developing agent consisting of a compound or a condensation product thereof with an aliphatic primary or secondary amine; or an alkaline agent such as an alkali carbonate, an alkali borate, or an organic aliphatic amine; Furthermore, ascorbic acids, kojic acids,
Air antioxidants such as phenols, resorcinols, pyritazines, cysteines, cystidines, ureas, primary, secondary or tertiary amines, hydrazines, hydroxylamines, etc.: 6-nitropenzimitazole, 5 - or development control agents such as 6-nitroindazole, 5-mercaptotetrazole, imidazoles, and tetrazaindenes; glycols such as triethylene glycol; organic solvents such as amines and alcohols; and polyalkylene oxides, etc. A halftone dot improver and the like can also be included as necessary.

In particular, the compounds of the present invention are described in U.S. Pat. No. 3,573,914;
It is also effective against infectious developers described in Japanese Patent Publication No. 45-6628, No. 48-76601, No. 48-50732, No. 48-41802, and No. 48-41803.

Although the compound of the present invention varies depending on the type of infectious developer and the type of lithium-type silver halide photosensitive material to be processed, it is generally effective in a range of about 0.1 to 50 g per 1 liter of infectious developer. It is also possible to use a combination of two or more selected from the general formula.

Next, typical examples of the compound represented by the above general formula will be shown.

These compounds represented by the above general formula have been described in various documents, and the present invention relates to novel uses of these compounds.

Examples of the lithium-type silver halide emulsions used in lithium-type photosensitive materials suitable for processing with the developer of the present invention include silver chloride emulsions, silver bromide emulsions, silver chlorobromide emulsions, silver chlorobromoiodide emulsions, Various emulsions such as silver chloroiodide emulsions can be mentioned, but especially 5
Silver halide emulsions containing 0 mol % or more of silver chloride are preferred.

These emulsions can be subjected to chemical sensitization such as gold sensitization or sulfur sensitization, or optical sensitization using sensitizing dyes such as cyanine dyes and merocyanine dyes.

Furthermore, various photographic additives such as contrast enhancers such as palladium, platinum, rhodium, and cobalt, stabilizers such as nitroimidazole, triazole, tetrazole, and tetrazaindene compounds, or accelerators such as anti-capri agents, imidazole, and mercaptobenzimidazole. , formaldehyde, halogen-substituted acids such as mucochromic acid, hardening agents such as ethyleneimine compounds, saponins, spreading agents such as polyethylene glycol, glycerin, esters of ethylene glycolic acid, polyvinylpyrrolidone, aqueous dispersions of synthetic resins (so-called latex). Physical property improvers such as these may also be included.

As the support for the squirrel-shaped photosensitive material barb, a suitable support such as synthetic resin such as polyethylene terephthalate, polycarbonate, cellulose triacetate, or glass may be used.

When the exposed lithium-type silver halide photosensitive material according to the present invention is processed with the developer having the above composition, excellent photographic properties can be obtained due to the stability of the photographic performance of the solution.

Next, the present invention will be explained in more detail with reference to Examples, but the embodiments of the present invention are not limited thereto.

Example 1 A lithium-type silver chlorobromide gelatin emulsion containing 70 moles of silver chloride was chemically sensitized using a combination of gold sensitization using chloroauric acid and sulfur sensitization using sodium thiosulfate, and then optically sensitized using a merocyanine dye. Then, general photographic additives such as a stabilizer, a hardening agent, and a spreading agent were added, and the mixture was coated and dried by a conventional method on a subbed polyethylene terephthalate film to produce a lithium-type photosensitive material.

The test piece was passed through a clay contact screen, brought into close contact with a step wedge, exposed to light using a tungsten lamp as a light source, and then exposed to an infectious developer containing the compound according to the present invention (7) (a) immediately after preparation and (b) exposed to the atmosphere. te3
After leaving it for a while, in both cases, it was heated to 27°C for 1 minute and 30 seconds, and then
Step development was carried out for 2 minutes and 30 seconds, followed by fixing, washing with water, and drying in a conventional manner.

The degree of comparison was measured for each test piece obtained, and the quality of the halftone dots was evaluated.

The results are shown in Table 1. The formulation of the infectious developer used was as follows.

Infectious developer solution hot water 750ml
Sodium sulfite (anhydrous) 3g Formaldehyde sodium bisulfite adduct 60g Hydroquinone 22g
Acid 6g sodium carbonate (monohydrate) 65g potassium carbonate (anhydrous) 20g triethylene glycol 30g 5-nitroindazole 5mg potassium bromide
1.5 g of the compound of the present invention (used as shown in Table 1) Add water to 1,000 ml For comparison test strips in the table, use a developer obtained by removing the compound of the present invention from the above-mentioned infectious developer, and use the same method as above. It is obtained by processing.

Ratings were made on a five-point scale, with those with sharp edges being grade 5 and those with very many fringes being grade 1.

As is clear from the above table, the infectious developer to which the compound of the present invention has been added has less decrease in sensitivity due to standing than the infectious developer to which the compound of the present invention is not added, and has better characteristics with less deterioration in halftone dot quality. It can be seen that it shows.

Example 2 The same procedure as in Example 1 was carried out except that the following infectious developer containing the compound according to the present invention was used.

The results are shown in Table 2.

Infectious developer solution Temperature: 750 ml Sodium sulfite (anhydrous) 2.5 g Infectious developer formaldehyde sodium bisulfite adduct 60 g Hydroquinone 18 g Boron
Acid 3g Potassium bromide 1.5g Sodium carbonate 75g Diethanolamine 2.5g Triethanolamine 30g Ethylene urea 1g 5-Nitroindazole 3mg Diethylene glycol 20g Add water
1000 ml As is clear from the above table, the test sticks obtained using the infectious developer containing the compound of the present invention exhibit better characteristics than the comparative sample.

This becomes even clearer when comparing the optimum development time.

Claims (1)

[Scope of Claims] 1. A developer for a photographic original plate for printing, characterized in that an infectious developer containing hydroquinone as a main component contains a compound represented by the following general formula (in the above formula, R1 is hydrogen, Arcanyl group, allyl group, aralkyl group, cycloalkyl group, amine group, acylamino group,
Carboamoyl group, halogen, carboxy group, carbalkoxy group, heterocyclic residue, R2 is hydrogen, alkyl group,
Indicates an allyl group, an aralkyl group, a cycloalkyl group, and a heterocyclic residue. )