JPH08292516A - Heat developable diazo copying material - Google Patents

Abstract

PURPOSE: To obtain a diazo copying material having a high image density and excellent in preservability over a long period of time. CONSTITUTION: 2,6-Dihydroxybenzoic acid, its deriv. or their salts represented by the formula are incorporated as a component coupling with a diazo compd. In the formula each of R1 and R3 is 1-4C alkyl, aralkyl, acetyl, ω-carboxyalkyl or halogen, R2 is H, hydroxyl, 1-4C alkyl, alkoxyl, oxyalkoxyl, carbamoyl, carbamoyloxy, propionyloxy or sulfoxyl and M is H or forms an alkali metallic salt, an ammonium salt, a guanidine salt or an org. amine salt.

Description

Detailed Description of the Invention [Industrial applications]

According to the present invention, a latent image is formed on a transparent or semi-transparent original by superposing and exposing the latent image, and then the latent image is developed by heat.
Regarding heat-developable diazo copying materials, further heat-sensitive recording materials,
In particular, it relates to a heat-sensitive recording material capable of being optically fixed.

[0002]

2. Description of the Related Art Heat-developable diazo copying materials are generally used for paper,
A photosensitive layer containing a diazo compound, a coupling component and a color-forming aid as a main component on a support such as a film,
Urea, sodium trichloroacetate and the like are used as color-forming aids. This type of diazo copying material is 180 ~
It is developed by heating at 200 ° C. The developing mechanism uses an alkali that is decomposed and generated by heating.
Further, as an attempt to develop at low temperature, a heat fusible substance such as higher fatty acid amide is used as a color developing aid, and the developing mechanism uses activation of a diazo compound and a coupling component by heating and melting. .

However, the conventional ones have a drawback that pre-coupling gradually progresses during storage and undesired coloring occurs. Therefore, JP-A-57-42042
JP-A-57-45094, JP-A-57-1250
As disclosed in No. 91, etc., the presence of any one of a diazo compound, a coupling component, and an alkali generator in the form of discontinuous fine particles prevents contact between the components and prevents precoupling. However, in this case, there arises a problem that the raw storage stability of the recording material is not sufficient. Further, JP-A-57-44141,
As disclosed in JP-A-59-190886, it is known that by encapsulating either a diazo compound, a coupling component or an alkali generator, it is isolated from other components. The method also did not fully satisfy the raw storability and the thermochromic property.

As another measure, in order to minimize the contact between the components, in JP-A-57-142391, the diazo compound and the coupling component are formed in separate layers, and heat-fusible is provided between the two layers. It is disclosed that a resin layer containing a volatile substance is interposed to separate the resin layer.
No. 315 discloses the use of a binder which is alkali-soluble and acid-insoluble in a developer layer containing a base. In the former, the diaphragm effect of the intermediate layer is not yet sufficient, and in the latter, Since a base coexists in the solution, insolubilization becomes insufficient, and precoupling during raw storage cannot be prevented.

[0005]

SUMMARY OF THE INVENTION The present invention solves the drawbacks of the conventional heat-developable diazo copying materials, has a high image density,
It is also an object of the present invention to provide a heat developable diazo copying material excellent in long-term storage stability and high reliability.

[0006]

According to the present invention, first, as a component for coupling with a diazo compound, 2,6-dihydroxybenzoic acid represented by the following general formula (I) or a derivative thereof or a derivative thereof is used. A heat-developable diazo copying material characterized by containing a salt is provided.

Embedded image (In the formula (I), R ₁ and R ₃ are alkyl groups having 1 to 4 carbon atoms,
Aralkyl group, acetyl group, omega-carboxyalkyl group or halogen, R ₂ is hydrogen, hydroxyl group, carbon number 1
~ 4 alkyl group, alkoxyl group, oxyalkoxyl group, carbamoyl group, carbamoyloxyl group, propionyloxyl group or sulfoxyl group, M represents hydrogen, alkali metal salt, ammonium salt, guanidine salt or organic amine salt. ) Secondly, in the heat-developable diazo copying material in which a developer layer containing at least an alkali-soluble resin and a heat-fusible substance and a photosensitive layer containing at least a diazo compound are provided on a support, There is provided a heat-developable diazo copying material characterized by containing 2,6-dihydroxybenzoic acid represented by the above general formula (I) or a derivative thereof or a salt thereof as a coupling component. Third,
In a heat-developable diazo copying material in which a developer layer containing at least an alkali-soluble resin and a heat-fusible substance and a photosensitive layer containing at least a diazo compound are provided on a support, the above-mentioned general component as a coupling component in the photosensitive layer There is provided a heat-developable diazo copying material characterized by containing 2,6-dihydroxybenzoic acid represented by the formula (I) or a derivative thereof or a salt thereof. Fourth, in the heat-developable diazo copying material in which a developer layer containing at least an alkali-soluble resin and a heat-fusible substance and a photosensitive layer containing at least a diazo compound are provided on a support, the above general formula (I And a layer containing 2,6-dihydroxybenzoic acid or a derivative thereof or a salt thereof is independently provided. Fifth, there is provided a heat-developable diazo copying material as described in the second, third or fourth, which contains a styrene-acrylic acid copolymer as an alkali-soluble resin. To be done. Sixth, in the heat-developable diazo copying material according to the second, third or fourth, containing a mixture of styrene-acrylic acid copolymer and isobutylene-maleic anhydride copolymer as an alkali-soluble resin. A featured heat developable diazo copying material is provided. Seventh, in the heat-developable diazo copying material described in the second, third, fourth, fifth or sixth, the heat fusible substance having a melting point in the range of 60 to 150 ° C. as the heat fusible substance. A heat developable diazo copying material characterized by containing a substance is provided.

The present invention will be described in detail below. As described above, in the present invention, the coupling component used in the heat developable diazo copying material is represented by the above general formula (I).
-By using dihydroxybenzoic acid or a derivative thereof or a salt thereof, it was found that a heat-developable diazo copying material which can maintain excellent image density and long-term storability can be obtained without containing a basic substance, and thus the present invention was completed. It is a thing.

In the present invention, the layer structure of the heat-developable diazo copying material containing a coupling component contains a developer layer containing at least an alkali-soluble resin and a heat-fusible substance on a support, and at least a diazo compound. In the constitution in which the photosensitive layer is provided, the above-mentioned coupling component can be contained in the developer layer, the photosensitive layer, or both. Further, a layer containing a coupling component may be provided separately from the developer layer and the photosensitive layer, and may be incorporated therein.

The coupling component according to the present invention can be used in a molecular form (dissolved and used), and can retain its long-term storability even if it is present in the same layer as the diazonium salt as described above. It is considered that this is because the coupling component according to the present invention is stable at room temperature and difficult to pre-coupling because the coupling reaction is not activated unless it is heated, and therefore it shows stable storage stability for a long time even if it is water-soluble. To be Further, in the present invention, an alkali-soluble resin (a resin that dissolves in alkalinity and insolubilizes in acidity) is used. Among them, styrene-acrylic acid copolymer, or styrene-acrylic acid copolymer and isobutylene-
A mixture of maleic anhydride copolymers is preferably used.

Further, in the present invention, a heat-fusible substance having a melting point in the range of 60 ° C. to 150 ° C. (a substance having a function of dissolving the coupling component or the alkali-soluble resin at the time of melting) is preferably used.

The materials used in the present invention will be described in detail below. Specific examples of 2,6-dihydroxybenzoic acid represented by the general formula (I) or a derivative thereof or a salt thereof used as the coupling component in the present invention include the following. 2,6-dihydroxybenzoic acid, ammonium 2,6-dihydroxybenzoate, potassium 2,6-dihydroxybenzoate,
Sodium 2,6-dihydroxybenzoate, 2,6-dihydroxy-3-benzylbenzoic acid, 2,6-dihydroxy-3-benzyl-5-bromobenzoic acid, 2,6-dihydroxy-3-bromo-4-methoxy Benzoic acid, 2,
6-dihydro-3,5-dibromo-4-methoxybenzoic acid and the like.

Further, in the present invention, a coupler used in a conventionally known diazo copying material can be used together with the above coupler. Examples of such a coupler include resorcin, phloroglucin, and 2,5-dimethyl-
4-morpholinomethylphenol, 3-hydroxycyanoacetanilide, parasulfoacetanilide, 1-benzoylamino-8-hydroxynaphthalene-3,6-
Disulfonamide, 2,2-dihydroxynaphthalene,
2,7-Dihydroxynaphthalene-3,6-disulfonic acid sodium, 2,3-dihydroxynaphthalene-6-sulfonic acid, 2,5-dihydroxynaphthalene-sulfonic acid sodium, 1-hydroxynaphthalene-4-sulfonic acid sodium, 1 -Amino-3-hydroxynaphthalene-3,6
-Disulfonamide, naphthol AS, naphthol AS
-D, 2-hydroxynaphthalene-3-biguanide,
2-hydroxy-3-naphthoic acid morpholinopropylamide, 2-hydroxy-3-naphthoic acid ethanolamide, 2-hydroxy-3-naphthoic acid-N, N-dimethylaminomorpholinopropylamide, 2,4,2 ',
4'-tetrahydroxydiphenyl, 2,4,2 ',
4'-tetrahydroxydiphenyl sulfoxide and the like can be mentioned.

The alkali-soluble resin is, for example, a styrene-acrylic acid copolymer, an isobutylene-maleic anhydride copolymer, a styrene-maleic anhydride copolymer or the like. When a styrene-acrylic acid copolymer is used, an isobutylene-maleic anhydride copolymer or styrene-
By mixing and using the maleic anhydride copolymer, the background fog can be further reduced. The mixing ratio at this time is 0.01 to 2.0 parts by weight, preferably 0.1 to 1.0 parts by weight, relative to 1 part by weight of the former.

Further, in the present invention, it is preferable to use a heat-fusible substance having a melting point of 60 ° C. to 150 ° C. in combination in order to promote the thermochromic property. The heat-fusible substance is a substance having a function of dissolving the coupling component or the resin when dissolved.
For example, alcohol derivatives such as 2-tribromoethanol, 2,2-dimethyltrimethylene glycol and 1,2-cyclohexanediol, waxes such as paraffin wax, microcrystalline wax, montanic acid wax, carnauba wax, monostearin and tristearin. And other higher fatty acid esters, other higher alcohols such as polyethylene glycol, polyethylene oxide and behenyl alcohol, higher polyhydric alcohols and higher ketones. In particular, the organic acid amide derivative represented by the following general formula (II) has a large dissolving action when dissolved, so that the coupling reaction proceeds efficiently and color development is promoted. R ₄ -CONH-R ₅ (II) (In the formula, R ₄ represents an alkyl group having 8 to 22 carbon atoms or an aryl group, R ₅ represents hydrogen, an alkyl group having 1 to 18 carbon atoms or an aryl group.)

Specific examples include higher fatty acid amide derivatives such as lauric acid amide, stearic acid amide, behenic acid amide, stearic acid methylolamide, and ethylenebisstearic acid amide, benzoic acid stearyl amide, and 2-naphthoic acid lauryl amide. , Myristic acid anilide, stearic acid anilide and the like. When the coupling component of the present invention is mixed with an organic acid amide derivative which is a heat-fusible substance and DSC is measured, eutecticization is observed and it is determined that the components have good compatibility with each other. The coupling component in the present invention is 0.1 to 1 with respect to 1 part by weight of the diazo compound.
0.0 parts by weight, preferably 0.8 to 4.0 parts by weight are used. If the amount is less than 0.1 parts by weight, insufficient coloring will occur, and conversely 1
If the amount is more than 0 parts by weight, undesired fog will occur during storage.

The heat fusible substance is 0.1 to 10.0 parts by weight, preferably 0.5 parts by weight, relative to 1 part by weight of the coupling component.
~ 5.0 parts by weight are used. If the amount is less than 0.1 parts by weight, insufficient color development occurs, and conversely, if the amount is more than 10 parts by weight, the feel is poor.

The diazo compounds used in the present invention have the general formula ArN ²⁺ X ^- is a diazonium salt represented by (wherein,
Ar represents a substituted or unsubstituted aromatic moiety, ArN ²⁺
Represents a diazonium salt, and X ⁻ represents an acid anion. ) Specific examples of the diazo compound include, for example, 4-diazo-
N, N-dimethylaniline, 4-diazophenylmorpholine, 4-diazo-N, N-dibutylaniline, 4-diazo-2,5-dimethoxyphenylmorpholine, 4-diazo-2,5-diethoxyphenylmorpholine, 4 -Diazo-2,5-dipropoxyphenylmorpholine, 4-
Diazo-2,5-dibutoxyphenylmorpholine, 4-
Diazo-2,5-dibutoxy-N-benzyl-N-ethylaniline, 4-diazo-2,5-dibutoxy-N, N
-Dibutylaniline, 4-diazo-2,5-dibutoxy-N-benzyl-N-oxyethylaniline, 4-diazo-2,5-dibutoxyphenylpiperazine, 4-diazo-2,5-diethoxyphenylpyrrolidine, 4-diazo-2,5-dipropoxyphenylpiperidine, 4-diazo-2,5-diethoxy-N, N-dimethylaniline, 4-diazo-1-benzoylamino-2,5-dibutoxybenzene, 4-diazo -1- (4'-methoxybenzoylamino) -2,5-dimethoxybenzene, 4-
Diazo-1- (4'-methoxybenzoylamino)-
2,5-diethoxybenzene, 4-diazo-1- (4 '
-Methylcibenzoylamino) -2,5-dipropoxybenzene, 4-diazo-1- (3'-chlorobenzoylamino) -2,5-diethoxybenzene, 4-diazo-
1- (3'-methoxybenzoylamino) -2,5-dibutoxybenzene, 4-diazo-1- (3'-methylcibenzoylamino))-2,5-dimethoxybenzene,
4-diazo-1-phenylmercapto-2,5-dipropoxybenzene, 4-diazo-1- (4'-toluylmercapto) -2,5-diethoxybenzene, 4-diazo-1- (4'-methoxy Phenylmercapto) -2,5
-Dibutoxybenzene, 4-diazo-1- (4'-chlorophenylmercapto) -2,5-dimethoxybenzene, 4-diazo-1- (3'-toluylmercapto)-
2,5-diethoxybenzene, 4-diazo-1- (3 '
-Methoxyphenylcapto) -2,5-dipropoxybenzene, 4-diazo-1- (2'-toluylmercapto) -2,5-dibutoxybenzene, 4-diazo-1-
Phenoxy-2,5-dibutoxybenzene, 4-diazo-1- (4′-methoxyphenoxy) -2,5-diethoxybenzene, and other chloride chlorides such as zinc chloride, cadmium chloride, and tin chloride double salts, and Examples thereof include salts of inorganic acids such as sulfuric acid, hexafluorophosphoric acid, and tetrafluoroboric acid of the diazo compound.

The diazo copying material of the present invention is preferably provided by laminating a photosensitive layer containing a diazo compound and a coupler layer containing a coupling component on a support such as paper or plastic film. The order of stacking is not particularly limited. Further, when the above-mentioned forming liquid is applied to the support as an aqueous solution or a dispersion, it may contain a binder, and as the binder, polyvinyl alcohol, polyacrylamide, casein, gelatin, starch and derivatives thereof, Water-soluble resins such as polyvinylpyrrolidone, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl acetate,
Various emulsion resins such as polyacrylic acid ester, vinyl chloride-acrylic acid ester copolymer and ethylene-vinyl acetate copolymer can be used.

Further, in the present invention, a precoat layer containing a fine particle powder and a binder as a main component is provided between the support and the light and heat sensitive layer for the purpose of increasing the image density and photosensitivity and improving the writability. It doesn't matter.

The fine particle powder used in the precoat layer is
Inorganic fine particle powder and organic fine particle powder can be used, and specific examples of the inorganic fine particle powder include silica, alumina, kaolin, talc, titanium, calcium carbonate, aluminum hydroxide, magnesium hydroxide and the like. Examples thereof include styrene resin particles, urea-formalin condensate resin particles, and benzoguanamine resin particles. As the binder, polyvinyl alcohol, polyacrylamide, casein, gelatin, starch and its derivatives,
Polyvinylpyrrolidone, carboxymethylcellulose,
Examples thereof include water-soluble resins such as methyl cellulose, ethyl cellulose and hydroxyethyl cellulose, and various emulsion resins such as polyvinyl acetate, polyacrylic acid ester, vinyl chloride-acrylic acid ester copolymer and ethylene-vinyl acetate copolymer.

In the heat-developable diazo copying material of the present invention, in addition to the above-mentioned color-developing component, various additives which are applied to ordinary diazo heat-sensitive recording materials can be used in combination.
For example, as the preservative improving agent, naphthalene-sodium monosulfonate, sodium naphthalene-disulfonate, sodium naphthalene-trisulfonate, sulfosalicylic acid, cadmium sulfate, magnesium sulfate, cadmium chloride, zinc chloride and the like can be used. Antioxidants include thiourea and urea, solubilizers such as caffeine and theophylline, and acid stabilizers such as citric acid, tartaric acid, sulfuric acid, oxalic acid, boric acid, phosphoric acid, and pyrroline. Acid or the like is used, and in addition, a small amount of saponin can be added.

When used as a light-fixing type heat-sensitive recording material, a filler can be added for the purpose of preventing sticking to the thermal head and improving running properties. Examples of such fillers include styrene resin fine particles, urea-formalin condensate resin fine particles, aluminum hydroxide, magnesium hydroxide, calcium carbonate, titanium, talc, kaolin, silica, alumina, and other organic and inorganic powders. Examples include fine particles. Metal soaps can also be used for the same purpose.

The heat-developable diazo copying material of the present invention can be advantageously applied to various other fields of heat-sensitive recording, in particular, as output recording paper for facsimiles, electronic computers and the like which require high-speed recording. In particular, in the case of the present invention, the characters and images recorded on the surface of the recording paper can be fixed by decomposing unreacted diazo compounds by exposure after image formation by heating, and therefore the operation is extremely difficult. It's easy. Further, the heat-sensitive recording material of the present invention can be applied to the recording of necessary items for securities, gift certificates, entrance tickets, certificates, slips, and the like, by utilizing its fixing property.

[0024]

The present invention will be described in more detail with reference to the following examples.

Example 1 A coupler dispersion having the following composition was prepared, coated on a surface of a high-quality paper using a wire bar and dried to give an adhesion amount of 4.5.
A developer layer (coupler layer) of g / m ² was formed. 2,6-Dihydroxybenzoic acid 2 g Styrene-ammonium acrylate copolymer aqueous solution (20%) 30 g (John polymer 679, Johncryl 679) Stearic acid amide dispersion (20%) 30 g Silica powder 1 g Polyvinyl alcohol aqueous solution (10%) ) 10 g water 27 g A photosensitive layer solution having the following composition was applied onto the above-mentioned coupler layer using a wire bar and dried to give an adhesion amount of 0.25 g.
A photosensitive layer of / m ² was formed. 4-diazo-1-morpholino-2,5-dibutoxybenzene chloride / 1/2 zinc chloride 1.5 g tartaric acid 1 g isopropanol 5 g saponin 0.1 g water 92.4 g As described above, the heat developable type of the present invention. A diazo copying material was prepared.

Example 2 A coupler solution having the following composition was prepared, and the surface of fine paper was coated and dried using a wire bar to deposit 4.5 g /
A m ² developer layer (coupler layer) was formed. 2,6-Dihydroxy-3-benzyl-5-bromobenzoic acid 2g Styrene-ammonium maleic anhydride copolymer aqueous solution (20%) (Kuraray SMA3000) 30g Behenamide dispersion (20%) 30g Silica powder 1g Aqueous polyvinyl alcohol solution (10%) 30 g Water 27 g A photosensitive layer solution having the following composition was applied onto the above coupler layer using a wire bar and dried to deposit 0.25 g / m 2.
^Two photosensitive layers were formed. 4-diazo-1-morpholino-2,5-dibutoxy benzene chloride / 1/2 zinc chloride 1.5 g tartaric acid 1 g isopropanol 5 g saponin 0.1 g water 92.4 g Heat developable diazo copy of the present invention as described above The material was made.

Example 3 A photosensitive layer solution having the following composition was prepared, coated on a surface of high-quality paper with a wire bar and dried, and an adhesion amount of 0.30 g / m
^Two photosensitive layers were formed. 4-diazo-1-morpholino-2,5-dibutoxy benzene chloride / 1/2 zinc chloride 1.5 g tartaric acid 1 g isopropanol 5 g saponin 0.1 g water 92.4 g A coupler solution having the following composition on the photosensitive layer. Was applied and dried using a wire bar to form a developer layer (coupler layer) having an adhesion amount of 4.5 g / m ² . 2,6-Dihydroxybenzoic acid ammonium 2 g Styrene-ammonium acrylate copolymer aqueous solution (20%) (John Cryl 679 manufactured by Johnson Polymer Co., Ltd.) 30 g Stearic acid amide dispersion (20%) 30 g Silica powder 1 g Polyvinyl alcohol aqueous solution (10 %) 10 g water 27 g A heat developable diazo copying material of the present invention was prepared as described above.

Example 4 A coupler aqueous solution having the following composition was prepared, coated on a surface of a high-quality paper using a wire bar and dried, and an adhesion amount of 0.30.
A coupler layer of g / m ² was formed. 2,6-Dihydroxybenzoic acid 2 g Water 98 g A developer layer dispersion liquid having the following composition was coated on the above coupler layer using a wire bar and dried to give an amount of adhesion of 4.0 g /
A developer layer of m ² was formed. Styrene-ammonium acrylate copolymer aqueous solution (20%) (John Cryl 679 manufactured by Johnson Polymer Co., Ltd.) 30 g Stearic acid amide dispersion (20%) 30 g Silica powder 1 g Polyvinyl alcohol aqueous solution (10%) 10 g Water 29 g The developer layer A photosensitive layer solution having the following composition was applied on the surface of the coated film using a wire bar and dried to give an adhesion amount of 0.25 g / m ²
To form a photosensitive layer. 4-diazo-1-morpholino-2,5-dibutoxy benzene chloride / 1/2 zinc chloride 1.5 g tartaric acid 1 g isopropanol 5 g saponin 0.1 g water 92.4 g Heat developable diazo copy of the present invention as described above The material was made.

Example 5 A coupler solution having the following composition was prepared and applied on the surface of a high-quality paper using a wire bar and dried to give an adhesion amount of 3.5 g / m 2.
^{The second} developer layer (coupler layer) was formed. 2,6-Dihydroxy-3-benzylbenzoic acid 2 g Styrene-ammonium acrylate copolymer aqueous solution (20%) (John polymer 679, Johncryl 679) 30 g Isobutylene-ammonium maleic anhydride copolymer aqueous solution (20%) ( Kuraray Isoban 104) 10 g Stearic acid amide dispersion (20%) 30 g Silica powder 1 g Polyvinyl alcohol aqueous solution (10%) 10 g Water 17 g A photosensitive layer solution having the following composition was coated on the above coupler layer using a wire bar and dried. And the adhesion amount is 0.25g / m
^Two photosensitive layers were formed. 4-diazo-1-morpholino-2,5-dibutoxy benzene chloride / 1/2 zinc chloride 1.5 g tartaric acid 1 g isopropanol 5 g saponin 0.1 g water 92.4 g Heat developable diazo copy of the present invention as described above The material was made.

Example 6 A developer solution having the following composition was prepared, and coated and dried on the surface of high-quality paper using a wire bar to form a developer layer having an adhesion amount of 4.5 g / m ² . Styrene-ammonium acrylate copolymer aqueous solution (20%) (John Cryl 679 manufactured by Johnson Polymer Co., Ltd.) 30 g Isobutylene-ammonium maleic anhydride copolymer aqueous solution (20%) (Kuraray Isoban 104) 10 g Stearic acid amide dispersion liquid (20%) 30 g Silica powder 1 g Polyvinyl alcohol aqueous solution (10%) 10 g Water 19 g A photosensitive layer solution having the following composition was applied onto the above developer layer using a wire bar and dried to give an adhesion amount of 0.55 g / m ² . A photosensitive layer was formed. 4-diazo-N, N-dimethylaniline chloride-1 / 2 zinc chloride 1.5g 2,6-dihydroxybenzoic acid 2g tartaric acid 1g isopropanol 5g saponin 0.1g water 90.4g heat of the present invention as described above. A developable diazo copying material was prepared.

Comparative Example 1 Thermal development was carried out in the same manner as in Example 1 except that 2,2-dihydroxynaphthalene was used in place of ammonium 2,6-dihydroxybenzoate in the coupler dispersion of the developer layer. A type diazo copying material was prepared.

Comparative Example 2 Instead of ammonium 2,6-dihydroxybenzoate in the coupler layer dispersion of Example 1, naphthol AS (2
A thermal development type diazo copying material was prepared in the same manner except that 0% dispersion liquid) was used.

Comparative Example 3 A heat developable diazo copying material was prepared in the same manner except that the aqueous styrene-ammonium acrylate copolymer solution in the coupler dispersion of Example 1 was omitted.

Comparative Example 4 A heat-developable diazo copying material was prepared in the same manner except that the stearamide dispersion in the coupler dispersion of Example 1 was omitted.

The heat-developing diazo copying material originals prepared as described above are overlapped and exposed with Copier Art 100 manufactured by Fuji Photo Film Co., Ltd.
When developed, a blue image was obtained. The density of the image area was measured with a Macbeth densitometer 914. Further, in order to test the raw storability, each sample was left in an environment of 50 ° C. and 50% RH for 24 hours to be forcibly deteriorated and then taken out, and the whole surface was exposed by the above copying machine to determine the density of the background portion by a Macbeth densitometer 91.
It was measured at 4. This was compared with the density of the background portion which was processed and measured in the same manner without forced deterioration. The results are shown in Table-1.
It was shown to.

[0036]

[Table 1]

[0037]

According to the present invention, by using 2,6-dihydroxybenzoic acid represented by the general formula (I) or its derivative or salt thereof as a coupling component, the image density is high, and A heat-developable diazo copying material having excellent raw storability can be obtained.

Claims (7)

[Claims] 1. A heat-developable diazo which contains 2,6-dihydroxybenzoic acid represented by the following general formula (I) or a derivative thereof or a salt thereof as a component to be coupled with a diazo compound. Copy material. Embedded image (In the formula (I), R ₁ and R ₃ are alkyl groups having 1 to 4 carbon atoms,
Aralkyl group, acetyl group, omega-carboxyalkyl group or halogen, R ₂ is hydrogen, hydroxyl group, carbon number 1
~ 4 alkyl group, alkoxyl group, oxyalkoxyl group, carbamoyl group, carbamoyloxyl group, propionyloxyl group or sulfoxyl group, M represents hydrogen, alkali metal salt, ammonium salt, guanidine salt or organic amine salt. ) 2. A heat-developable diazo copying material comprising a support, on which a developer layer containing at least an alkali-soluble resin and a heat-fusible substance and a photosensitive layer containing at least a diazo compound are provided. 2. A heat-developable diazo copying material containing the 2,6-dihydroxybenzoic acid or its derivative or salt thereof according to claim 1 as a coupling component. 3. A heat-developable diazo copying material comprising a support, on which a developer layer containing at least an alkali-soluble resin and a heat-fusible substance and a photosensitive layer containing at least a diazo compound are provided. A heat-developable diazo copying material containing the 2,6-dihydroxybenzoic acid according to claim 1 or a derivative thereof or a salt thereof as a ring component. 4. A heat-developable diazo copying material comprising a support, on which a developer layer containing at least an alkali-soluble resin and a heat-fusible substance and a photosensitive layer containing at least a diazo compound are provided. 2. A heat-developable diazo copying material characterized in that a layer containing 2,6-dihydroxybenzoic acid or a derivative thereof or a salt thereof is independently provided. 5. The heat-developable diazo copying material according to claim 2, 3 or 4, which contains a styrene-acrylic acid copolymer as an alkali-soluble resin. 6. The heat-developable diazo copying material according to claim 2, 3 or 4, which contains a mixture of a styrene-acrylic acid copolymer and an isobutylene-maleic anhydride copolymer as an alkali-soluble resin. Heat developable diazo copying material. 7. The heat developable diazo copying material according to claim 2, 3, 4, 5 or 6, which contains a heat fusible substance having a melting point in the range of 60 ° C. to 150 ° C. A heat-developable diazo copying material characterized in that