JPS6228456B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a diazo photosensitive material,
More specifically, the present invention relates to a so-called two-component diazo-sensitive material comprising a photosensitive diazo compound and a coupler, which has improved image density and contrast. Diazo-sensitive materials, especially those containing both a diazo compound and a coupler, are wet-type diazo-sensitive paper that develops color with an alkaline aqueous solution, and can also be used dryly (ammonia development) to produce colored images. Acts as both dry and dry. Generally, in the production method of two-component diazo photosensitive materials, before the diazo photosensitive solution is applied to a support, especially base paper, the surface of the base paper is precoated with a suitable powder together with a binder to improve the density and contrast of the resulting image. There is a two-coat method to improve the image quality, and a one-coat method in which a powder and a binder are applied to the base paper along with a diazo photosensitive liquid for the same purpose. The method of having a precoat of
You can see many patents including No. 2433515,
As shown in the same patent, this effect is due to ``preventing the diazo photosensitive liquid from seeping into the paper layer and keeping all the diazo compound on the surface''. If precoating is not performed, the diazo compound that has entered behind the fibers of the base paper remains undecomposed by active light and appears as a background stain during the coloring process. Therefore, if all the diazo compound remains on the surface by precoating, an image can be effectively formed and these disadvantages can be eliminated. Next, in order to omit the pre-coating step, a method of mixing a suitable powder into the diazo photosensitive layer to provide a pre-coating effect has also been shown in US Pat. However, it is still in practical use and is called pseudo-precoat. The powders subjected to these two methods range from inorganic materials such as colloidal or non-colloidal silica, alumina pigments, aluminum silicate, barium sulfate, and titanium dioxide to starch, polystyrene resin powder, and styrene-acrylic acid copolymer powder. So-called adsorbent substances are known that range from organic substances such as . However, it is still not possible to find an effective adsorbent that has the effect of improving the image density and contrast produced by these powders for precoat and pseudo-precoat. There were also problems with its versatility, such as the inconvenience of coagulation and precipitation when coexisting. The purpose of the present invention is to improve the density and contrast of generated images, and to realize a two-component diazo photosensitive material consisting of a specific diazo compound and a coupler, which have conventionally had difficulty coexisting with powders, that is, adsorbed substances. be. The present invention was achieved as a result of extensive research into adsorbed substances to satisfy the copying performance and versatility of diazo photosensitive materials. A photosensitive material comprising a support with or without a precoat underneath, characterized in that the photosensitive layer and/or the precoat layer contains urea-formaldehyde resin powder forming secondary agglomerated particles of fine particles. I will provide a. In preparing the photosensitive material coating solution used to form the photosensitive layer, diazo compounds generally have low solubility in water, and when inorganic fine powder is mixed with the aqueous solution, the diazo compounds precipitate or form tar-like precipitates. This is especially true when Kuppura coexists. Furthermore, if a binder is used in combination to prevent the powder from peeling off after application, this will be further aggravated. Furthermore, if a coating liquid containing powder is subjected to some kind of mechanical agitation to prevent precipitation during storage and during the coating process, the stability of the coating liquid will be hindered and precipitation will further accelerate. This tendency can be seen, for example, in the diazo compounds () and coupler () represented by the following formulas, which have the best photosensitivity. However, R ₁ represents a C _1-4 alkyl group, and X represents an anion. However, R ₂ and R ₃ are C _1-3 alkyl groups, or

[Formula] is shown, and n is an integer of 2 or 3. This is particularly noticeable in combinations of This is because the diazo compound of the general formula () is extremely difficult to dissolve in water, and even when used alone or in combination with the coupler of the general formula (), it is difficult to dissolve and tends to precipitate.
This is evident from the necessity of co-solvents such as trisulfonic acid, caffein and others. If organic polymer powder, especially urea formaldehyde resin powder, which forms secondary agglomerated particles of fine particles is added to the coating liquid, no agglomeration and precipitation will occur, and the amount of binder can be suppressed. By not impairing the stability of the photosensitive coating liquid, the resulting image has good density and contrast, making it possible to put it into practical use. The reason why urea-formaldehyde resin powder, which forms secondary agglomerated particles, shows an effect that other powders do not have is not well understood, but whether its adsorption mechanism is physical or chemical, the adsorption area is This seems to be due to the fact that it has a high affinity for aqueous photosensitive solutions. That is, the powder is a porous amorphous powder in which fine particles of 0.05 to 0.15 μm are secondary agglomerated, with a size of 3 to 10 μm, a porosity of 80 to 95%, and a specific surface area of 20 to 10 μm.
30m ² /g, it adsorbs the diazo compound well and prevents the diazo compound from penetrating into the base paper.It is also insoluble in water, but in the case of urea-formaldehyde resin powder, there are residual methylol groups, so it is difficult to absorb the diazo compound into the base paper. It is thought that this contributes to the fact that the amount of binder can be suppressed. Furthermore, the improvement of image density and contrast produced by the present invention can be achieved not only by immediately including the secondary agglomerated powder only in the photosensitive layer, but also by including it in a precoat layer provided by a two-coating method. be done. The method is not limited in any way as long as it follows the usual method of providing an inorganic or organic adsorbent. Further, the urea-formaldehyde powder of the present invention may be used alone or in combination with other conventional powders. Representative examples of the urea-formaldehyde powder used in the present invention include various urea-formaldehyde resin powders commercially available as paper fillers, such as Pargopak-M (Ciba Geigy), Cab
-O-Lite (Cabot) or SUNPAC (Nissan Chemical Industries, Ltd.) are recommended because they are easily available. Although the amount used cannot be determined uniquely depending on whether it is provided in the photosensitive layer, whether it is provided in the precoat layer, or the binder used in combination, in the case of the photosensitive layer, it is 100 to 500% by weight based on the diazo compound and the so-called coloring component of Coupler. %, preferably 150 to 300% by weight, less than 100% by weight is less effective.
If the amount exceeds % by weight, coating liquid adjustment may be impaired or there may be restrictions due to economic reasons. Similarly, in the case of a precoat layer, it is sufficient to follow the usual method of providing an adsorbent, which is 20 to 300% by weight, preferably 100 to 200% by weight of the binder.
A solid content of 0.1 to 1 g/m ² by weight can be provided. The present invention does not preclude the inclusion of additives such as acid coupling inhibitors, browning inhibitors, and wetting inhibitors. Representative examples of the diazo compound, coupler, acid coupling agent and binder are as follows. Examples of diazonium compounds are N,N-dimethyl-4-aminobenzenediazonium chloride,
N,N-diethyl-4-aminobenzenediazonium chloride, N,N-dipropyl-4-aminobenzenediazonium chloride, N-ethyl-N-β-hydroxyethyl-4-aminobenzenediazonium chloride, N,N-diaryl- 4-aminobenzenediazonium chloride,
N,N-bis-β-hydroxyethyl-4-aminobenzenediazonium chloride, 2,5-diethoxy-4-morpholinobenzenediazonium chloride, 2,5-dibutoxy-4-morpholinobenzenediazonium chloride, 4'-methoxy -4-Benzoylamidobenzenediazonium chloride, 4'-methoxy-4-benzoylamide-2,5-diethoxybenzenediazonium chloride, N,N-bis-γ-hydroxypropyl-4-aminobenzenediazonium chloride, N-methyl -N-hydroxy-4-aminobenzenediazonium chloride, N-methyl-N
-benzyl-4-amino-2,5-dimethoxybenzenediazonium chloride, 2,5-diethoxy-4-(p-tolyl)mercaptobenzenediazonium chloride and other compounds and zinc chloride,
These include double salts such as cadmium chloride and tin chloride, and salts of boron tetrafluoride in place of chlorine in the diazonium salts mentioned above. Examples of couplers are 2,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1-
Sodium hydroxynaphthalene-4-sulfonate, sodium 2,3-dihydroxynaphthalene-5-sulfonate, sodium 2,3-dihydroxynaphthalene-6-sulfonate, sodium 2,5-dihydroxynaphthalene-6-sulfonate, 2-
Hydroxy-3-naphthoic acid-β-aminoethylamide, 2-hydroxy-3-naphthoic acid-β-
Hydroxyethylamide, 2-hydroxy-3-
Naphthoic acid-β-morpholinoethylamide, 2
-Hydroxy-3-naphthoic acid-γ-aminopropylamide, 2-hydroxy-3-naphthoic acid-
γ-Hydroxypropylamide, 2-hydroxy-3-naphthoic acid-γ-morpholinopropylamide, 1-biguanidino-7-naphthol, resorcinol, α-resorcinic acid ethanolamide, ethylenediamine-N,N'-bisacetoacetyl Amide et al. Examples of acid precoupling inhibitors are citric acid, butyric acid, oxalic acid, tartaric acid, sulfuric acid, boric acid, naphthalene trisulfonic acid, benzenesulfonic acid, and the like. Examples of binders include gelatin, starch, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, maleic anhydride copolymers, and aqueous emulsifying resins such as vinyl acetate, acrylic, and styrene-butadiene. EXAMPLES Next, Examples will be shown to further specifically explain the present invention, but the present invention should not be limited thereto. Example 1 (% by weight) Tartaric acid 1 Aluminum sulfate 0.7 2-hydroxy-3-naphthoic acid dimethylpropylamide 1 2,5-dibutoxymorpholinobenzenediazonium chloride 1.2 Zinc chloride 1 Urea-formalin resin powder (manufactured by Ciba Geigy, trade name: Pargopak) -M)
5 Polyvinyl acetate emulsion (solid content 50%) (manufactured by Nippon Carbide Co., Ltd., trade name Nikazole RX)
-472) 20 Saponin 0.1 Add water to make total volume 100. No precipitation was observed at all after 10 hours had elapsed after stirring and adjusting the photosensitive solution having the above composition. Example 2 Tartaric acid 1 Aluminum sulfate 0.7 2-hydroxy-3-naphthoic acid morpholinoethylamide 1.5 2,5-diethoxymorpholinobenzenediazonium chloride 1.2 Zinc chloride 1 Pergopack M 5 Polyacrylic emulsion (solid content 46%) (Roam & Made by Haas, Primal C-72
) 7 Saponin 0.1 Add water to make total volume 100. No precipitation was observed at all after 10 hours had elapsed after stirring and adjusting the photosensitive solution having the above composition. Example 3 The photosensitive liquids of Examples 1 and 2 and Pargopak-M in Example 1 as Comparative Example 1 were mixed with the conventionally known Thyroid 244.
Immediately after adjusting the photosensitive solution (colloidal silica, sold by Fuji Davison), each was 68 g/m ²
Coat 13g/m ² (wet) on photosensitive base paper and dry.
After exposure, development was performed with ammonia vapor to obtain a blue image. Image density is Example 1, 1.42, Example 2, 1.37
and Comparative Example 1, 1.20, and the background stain is Example 1.
Although it was not observed in Comparative Example 1 and 2, the background stain was noticeable, confirming the effect of the present invention. Example 4 (parts by weight) Citric acid 1 Aluminum sulfate 0.5 2,5-diethoxymorpholinobenzenediazonium chloride 2 Urea formalin resin powder (manufactured by Cabot, trade name Cab-O-Lite) 5 Polyvinyl acetate emulsion (solid content) 55%) (manufactured by Nippon Carbide Co., Ltd., trade name: Nikazol)
RX201A) 10 Saponin 0.1 Add water to make total volume 100. After stirring and adjusting the one-component photosensitive liquid consisting of the above composition.
No sedimentation was observed after 10 hours.
Cab-
Immediately replace O-Lite 100 with Cyroid 249 (colloidal silica, Fuji Davison).
A 13 g/m ² (wet) coating was applied to a 68 g/m ² photosensitive base paper and dried, and after image exposure, it was developed with the following developer to obtain a purple-blue image. The image density was 1.20 in Example 4 and 1.10 in Comparative Example 2, with no background staining in Example 4 and background staining in Comparative Example 2. Developer (parts by weight) Borax 5 Sodium carbonate 3 Thiourea 1 Sodium 1-naphthol-4-sulfonate 2 Add water to make the total volume 100. Example 5 (Parts by weight) Pergo Pack M 3 Polyvinyl acetate emulsion (solid content 50%) (manufactured by Nippon Carbide Co., Ltd., trade name Nikazol RX)
-472) 10 Add water to make the total volume 100. A pre-coat solution having the above composition was applied to a photosensitive base paper of 68 g/m ² at a solid content of 0.5 g/m ² , and then the next photosensitive solution was coated at 13 g/m ² and dried. Photosensitive liquid (parts by weight) Citric acid 2 Sodium 2,3-dihydroxynaphthalene-6-sulfonate 4 Paradiazodiethylaniline zinc chloride double salt
2 Thiourea 2 Zinc chloride 3 Saponin 0.1 Add water to make the total volume 100. As Comparative Example 3, a photosensitive base paper without precoating was coated with the above photosensitive liquid, and both images were exposed.
Developed with ammonia vapor. At that time, the blue image density in Example 5 was white and clear, and in Comparative Example 3, background stains were observed. Example 6 2-hydroxy-3-naphthoic acid dimethylpropylamide in Example 1 was added to 2,5-dihydroxynaphthalene-5-sulfonic acid sodium, 2,
Example 3 The photosensitive solution obtained by repeating Example 1 except that 5-dibutoxymorpholinobenzenediazonium chloride was replaced with N,N-dimethyl-4-aminobenzenediazonium chloride.
The photosensitive paper obtained by processing according to the method showed the same effect as in Example 1.

Claims (1)

[Scope of Claims] 1. A photosensitive material comprising a support with or without a precoat on the surface of a diazo photosensitive layer consisting of a photosensitive diazo compound and a coupler and below the layer, in which the photosensitive layer and/or the precoat layer are Forms secondary agglomerated particles of fine particles, 3 to 10μ in size
m, porosity 80-95%, specific surface area 20-30m ² /g
A diazo photosensitive material containing urea-formaldehyde resin powder. 2. The diazo photosensitive material according to claim 1, wherein the photosensitive diazo compound is represented by the general formula () and the coupler is represented by the general formula (): Formula () (However, R ₁ represents a C _1-4 alkyl group and X represents an anion.) Formula () (However, R ₂ and R ₃ represent a C _1-3 alkyl group or [Formula], and n represents an integer of 2 or 3).