JPS6039643A - Image forming method - Google Patents

Abstract

PURPOSE:To form a stable blue image prevented from coloring on the background by coupling a hydrazone coupler with a diazonium salt and chelating it with a transition metal compd. CONSTITUTION:A dye image is formed by reacting a diazonium salt in the presence of alkali with a hydrazone coupler represented by general formula I in which R is beta-pyridyl or gamma-pyridyl, and chelating the reaction product with a transition metal compd.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an image forming method for forming bright blue images, and more particularly, to a method for forming a bright blue image, and more particularly, for obtaining a diazo copying material using an aqueous photosensitive layer forming liquid and forming a stable chelate dye thereon. The present invention relates to an image forming method for obtaining an image.

BACKGROUND OF THE INVENTION In conventional image forming methods, diazo copying materials have been used in which images are formed by a coupling reaction between a diazo compound and a coupler for the compound. Diazo copying materials include
There are two-component copying materials: one-component copying materials in which a diazo compound is supported on the surface of a support, such as paper, and two-component copying materials in which a diazo compound and a coupler are supported on the support. After irradiation with light, i.e., imagewise exposure 1, the image is developed using an alkaline developer containing a coupler. The diazo compound and the coupler, which remain undecomposed, are coupled under alkaline conditions without being exposed to light (and therefore without being decomposed) during image exposure. Obtaining copies with dye images in this manner is well known to those skilled in the art.

Many compounds have been proposed as couplers for use in diazo copying materials and which produce azo dyes by coupling with diazo compounds, and have been put into practical use.

For example, there is a hydrazone compound represented by the following general formula (1). This coupler can produce a stable black image with a gray or blue tinge even if the developing conditions vary slightly, but on the other hand, it is pale yellow or deep yellow, which makes it difficult to see the background. It has the disadvantage of coloring and impairing image clarity.

Also, Japanese Patent Application Laid-open No. 54-35723 and No. 54 filed by the present applicant.
-35724 and No. 54-30023, the coupler not only has low water solubility and is impractical, but also is colored yellow, so like the couplers mentioned above, the background is colored and image clarity is impaired. It has the disadvantage of causing damage.

Purpose The purpose of the present invention is to solve the above-mentioned conventional drawbacks, and more specifically, to prepare a copying material using an aqueous diazo photosensitive layer forming liquid, and to provide a stable copying material with no background coloration in the copying material. An object of the present invention is to provide an image forming method capable of forming a blue image.

Structure As a result of various studies in view of the purpose of the present invention, it was found that a compound represented by the following general formula I was used as a coupler in a diazo copying material, and after coupling the coupler with a diazonium salt in the presence of an alkali, a transition metal compound and Kirei-1~
It has been found that upon reaction a stable blue dye image is formed and the objects of the invention are achieved.

N (In the formula, R represents β-pyridyl or γ-pyridyl.

) Since the coupler represented by the general formula I of the present invention is itself white and water-based, the images obtained are clear without background coloration, and the photosensitive layer liquid can also be water-soluble. can. In addition, the above-mentioned coupling quickly couples with the diazonium salt, and after the coupling, it is easily converted to a transition metal, so that image formation can be carried out in a short time, which is practically preferable. The reason why the compounds of the above general formula were used as 7J tupler in the present invention is that they were experimentally found to be more water-soluble than pyridylhydrazone type compounds having various other water-soluble groups. , the reason why only compounds in which R is an α- or β-pyridyl group was used is that when R is a γ-pyridyl group, the tridentate coordination in this compound is The atoms (i.e., N in the pyridine rings at both ends and N in NH in the hydrazone part) themselves may chelate with the transition metal before coupling with the diazonium salt, or the coupler remaining after coupling may chelate with the transition metal compound. This is because the skin tends to turn yellow due to the oxidation.

As the diazonium salt used with the coupler of the present invention, any salt used in ordinary diazo copying materials can be used, and specific examples include the following salts of diazo compounds.

4-Diazo-2,5-dimethoxyphenylmorpholine, 4-diazo-2,5-jethoxyphenylmorboline, 4-diazo-2,5-dipropoxyphenylmorboline, 4-diazo-2,5-dibu1 ~xif'nil 1 ruforin, 4-diazo-2,5-dibu 1 ~xy-N-benzyl-N
-ethylaniline, 4-diazo-2,5-dibutoxy-N, N-dibutylaniline, 4-diazo-2,5-dibutoxy-〇-benzyl-N-
Hydroxyethylaniline, 4-diazo-2,5-dibutoxyphenylbiberidine, 4-diazo-3-methyl-xyphenylpiperidine, 4-diazo-2,5-die-1-xyphenylpyrrolidine, 4-diazo -2,5-dipropoxyphenylpiperazine, 4-diazo-N,N-dimethylaniline, 4-diazo-
N,N-diethylaniline, 4-diazo-N-ethyl-
N-hydroxyethylaniline, 4-diazo-N,N-dipropylaniline, 4-diazo-phenylmorpholine, 4-diazo-phenylpyrrolidine, 4-diazo-2-methylphenylpyrrolidine.

When a compound having the above general formula is used as a coupler in a two-component copying material, additives such as sodium naphthalene mono-, di-, or mono-sulfonate, sulfosalicylic acid, urea, thiourea, sulfuric acid, tartaric acid, etc. , citric acid, malic acid, malonic acid, caffeine, diophylline, saponin, etc. are used.

Examples are presented below to explain the invention in more detail.

Example 1 A photosensitive layer forming solution was prepared by mixing the following components. 19-phenylmorpholine chloride Nickel benzenesulfonate: 1g Saponin: o, ig Water: 100nl The above photosensitive layer forming liquid was applied to white base paper for diazo copying material and dried to obtain a two-component diazo copying material. child .

The copying material thus obtained was transferred to a diazo copying machine (SD-
450 (manufactured by Ricoh) to form a blue complex image, the resulting image was a clear image with no background coloring, and the image quality did not deteriorate over time.

Example '2 A diazo copying charge was prepared in the same manner as in Example 1 except that A3 and C1 were used as the couplers, and an image was formed. As in Example 1, a stable blue image with no background coloration was obtained. Obtained.

Further, the photosensitive layer forming liquids of Examples 1 and 2 were stable enough to withstand storage.

Comparative Example When a diazo copy was prepared in the same manner as in Example 1 except that μ was used as a coupler, and an image was formed, an unclear blue image with a yellow background was obtained. The coloring of the background area depends on whether the tridentate coordination 1-Kyoko N of the coupler used is chelated with a transition metal compound before coupling the coupler with the diazonium salt, or whether the remaining coupler after image formation is chelated with a transition metal compound. This is because a chelate was formed in the presence of an alkali.

Effects As explained above, according to the image forming method of the present invention, the obtained image is a clear blue image without background coloration, and is a stable image whose image quality does not deteriorate over time. Furthermore, since the coupler used in the present invention has high water solubility, a stable photosensitive layer forming solution can be obtained.

Patent applicant Rico Co., Ltd. Agent Patent Attorney Hidetake Komatsu 1 person

Claims (1)

[Claims] A hydrazone coupler represented by the following general formula (2) is combined with a diazonium salt in the presence of an alkali,
An image forming method characterized by forming a dye image by then reacting with a transition metal compound. (In the formula, 1 represents β-pyridyl or γ-pyridyl.)