JPH03253846A - Production of diazo photosensitive material - Google Patents

Abstract

PURPOSE:To prevent the lowering of sensitivity with the lapse of time by using an emulsion of a hydrophobic high molecular compd. emulsified with a water soluble high molecular compd. as a binder in a photosensitive liq. compsn. CONSTITUTION:When a photosensitive liq. compsn. contg. a photosensitive diazo compd., a coupling component and a porous inorg. pigment as essential components is applied to the surface of a base and dried to produce a single- layer diazo photosensitive material, an emulsion of a hydrophobic high molecular compd. emulsified with a water soluble high molecular compd. is used as a binder. This emulsion has superior properties as protective colloid and is stable even in the photosensitive liq. compsn. Any emulsion having superior properties as protective colloid may be used as the binder but modified or unmodified PVA or methylcellulose is preferably used. A diazo photosensitive material hardly lowering the sensitivity with the lapse of time can be obtd. by coating with a single layer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a diazo photosensitive material, and more specifically, a two-fraction type diazo photosensitive material that is prepared from a photosensitive diazo compound and a coupling component. The present invention relates to a manufacturing method for manufacturing by single-layer coating.

[Prior art] A diazo-sensitive material containing both a photosensitive diazo compound and a coupling component is a wet-type diazo-sensitive paper that develops color with an alkaline aqueous solution, and can also be used in a dry process (ammonia development). It has a so-called wet/dry function that allows you to obtain a colored image.

However, during the production of the above-mentioned diazo photosensitive materials, it is necessary to coat a liquid composition with a low solid content concentration and low viscosity on the support due to the solubility of the photosensitive diazo compound. If the photosensitive liquid composition is permeable, deterioration in sensitivity over time, which is thought to be caused by the permeation of the photosensitive liquid composition into the support, has become a problem.

In general, as a manufacturing method for diazo photosensitive materials in order to reduce such a decrease in sensitivity, before the above-mentioned photosensitive liquid composition is provided on a support, especially a base paper, (1) a suitable porous inorganic pigment is precoated on the surface of the base paper together with a binder. A two-coating method in which the photosensitive liquid composition is coated on top of the photosensitive liquid composition to prevent it from penetrating into the support base paper.

(2) For the same purpose, a one-coat method has been implemented in which a photosensitive liquid composition, a porous inorganic pigment, and a binder are provided on a base paper support.

The method of providing a pre-coat (①) is disclosed in U.S. Patent No. 243351.
Many patents, including No. 5, can be found, and the effect, as shown in the same patent, is to "prevent the diazo photosensitive liquid from penetrating into the paper layer and keep the diazo compound on the surface."

However, providing a plurality of layers on a support is not only complicated in terms of process but also disadvantageous in terms of cost, and cannot be said to be an industrially useful method.

In this respect, the single-layer coating method described in (2) is effective, but the problem was how to suppress the penetration of the photosensitive liquid.

[Purpose of the Invention] The present invention has been made in view of these drawbacks, and its purpose is to apply a photosensitive liquid composition containing a photosensitive diazo compound, a coupling component, and a porous inorganic pigment as main components to the surface of a support. In the manufacturing method of diazo photosensitive materials, which are manufactured by coating and drying, the use of an emulsion of a hydrophobic polymer compound emulsified with a water-soluble polymer compound as a binder makes it possible to easily produce diazo photosensitive materials with less loss of sensitivity over time. It could be manufactured by layer coating.

[Structure of the Invention] In order to achieve the above-mentioned object, the present inventor conducted extensive studies on diazo photosensitive materials and arrived at the present invention.

It can be easily assumed that suppressing the penetration of the photosensitive liquid composition into the paper layer is an effective means for preventing sensitivity deterioration over time. In order to manufacture a single layer without providing it in advance, it is necessary to add a binder to the photosensitive liquid composition, but when a water-soluble polymer compound is used as the binder, it absorbs moisture in the atmosphere due to its hydrophilic nature. Therefore, the photosensitive composition gradually penetrates into the paper layer, making it difficult to prevent a decrease in sensitivity over time.

Additionally, photosensitive liquid compositions are generally strongly acidic to prevent pre-coupling, and are complex systems containing metal salts to improve image storage stability, and when an emulsion of a hydrophobic polymer compound is added. Stable industrial production was impossible because the emulsion was easily destroyed.

On the other hand, the emulsion of a hydrophobic polymer compound emulsified with a water-soluble polymer compound as in the present invention has excellent protective colloidal properties and is stable even in a photosensitive liquid composition. By manufacturing a diazo-sensitive material, it was possible to produce a diazo-sensitive material with little decrease in sensitivity over time by single-layer coating.

Any water-soluble polymer compound used for emulsifying the emulsion can be used as long as it has excellent protective colloid properties, but modified or unmodified polyvinyl alcohol, methyl cellulose, etc. are particularly preferred.

As the hydrophobic polymer compound to be made into an emulsion, any known composition can be suitably used, but in particular, acrylic,
Styrene/acrylic, vinyl acetate, vinyl chloride, or copolymers thereof are desirable.

Further, the Tg of the hydrophobic polymer compound is desirably from -20'C to 50°C, and if it is below -20°C, the image will not fade easily and if it is above 50°C, it will cause a decrease in color development.

As the photosensitive diazo compound, any compound commonly used in diazo photosensitive materials can be used, but specific examples include: 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-jethoxy-4-morpholinobenzenediazonium chloride, 2.5-dibutoxy-4-morpholinobenzenediazonium chloride , 4'-methoxy-4-benzoylamide benzenediazonium chloride, 4'-methoxy-4-benzoylamide-2,5-jethoxybenzenediazonium chloride, N,N-bis-γ-hydroxypropyl-4-aminobenzenediazonium chloride , N-methyl-N-hydroxy-4-
Compounds such as aminobenzenediazonium chloride, N-methyl-N-benzyl-4-amino-2,5-dimethoxybenzenediazonium chloride, 2,5-jethoxy-4-(p-tolyl)mercaptobenzenediazonium chloride, and zinc chloride. , double salts such as cadmium chloride and tin chloride, or boron tetrafluoride salts in place of chlorine in the above-mentioned diazonium salts.

Specific examples can be appropriately selected from the diazo compounds listed above.

Examples of coupling components are 2,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, sodium 1-hydroxynaphthalene-4-sulfonate, sodium 2,3-dihydroxynaphthalene-5-sulfonate, 2,3-dihydroxy Sodium naphthalene-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- These include 3-naphthoic acid-γ-morpholinopropylamide, 1-biguanidino-7-naphthol, resorcinol, α-resorcinic acid ethanolamide, ethylenediamine-N, N'-bisacetoacetylamide, and the like.

In the present invention, the appropriate ratio of the diazo compound to the coupling component is about 0.5 to 5 by weight.

In the present invention, in addition to the above-mentioned materials, various auxiliary additive components commonly used in diazo photosensitive materials can be used.

As such, for example, as a development accelerator,
Ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, etc. or their derivatives; as storage improvers, sodium naphthalene monosulfonate, sodium naphthalene disulfonate, sodium naphthalene trisulfonate, sulfosalicylic acid, cadmium sulfate, sulfuric acid; Metal salts such as magnesium, cadmium chloride, and zinc chloride, antioxidants such as urea compounds and thiourea compounds, solubilizing agents such as caffeine, acid stabilizers such as citric acid, tartaric acid, sulfuric acid, oxalic acid, Porous inorganic pigments such as boric acid and phosphoric acid include various types of silica, as well as fine particles of kaolin, talc, clay, aluminum hydroxide, and the like.

Other additives that can be used include waxes, higher fatty acid surfactants, and dispersants.

To produce the diazo photosensitive material of the present invention, a diazo compound, a coupling component, a porous inorganic pigment, a binder,
A coating liquid in which other auxiliary additive components are dissolved or dispersed is coated on a support by a conventional coating method and dried, resulting in a coating amount of 1.
5-15. A photosensitive layer of 0g1rd may be provided.

[Examples] The present invention will now be explained in more detail by way of examples. Parts in the following examples are based on weight.

Example 1 0 Caffeine 15 parts Citric acid 15 parts Triethylene glycol 35 parts Thiourea
40 parts 2.3-dihydroxynaphthalene 6-sulfonic acid sodium 15 parts 4-diazo-N, N-dimethylaniline chloride 1/2 ZnC
1210 parts Zinc chloride 60 parts Thyroid 74 20 parts Styrene/acrylic emulsion with PVA as an emulsifier Add water to make a total of 1 liter of a mixture, apply this onto a support and dry it to give about 2.5 g /rd photosensitive layer was provided.

Example 2.3 Example 23 was carried out in the same manner as in Example 1 except that 10 parts of an acrylic emulsion using methylcellulose as an emulsifier as the binder agent in Example 1 and 10 parts of a styrene/acrylic emulsion using carboxy-modified PVA as an emulsifier were used. Created.

Comparative example↓ Caffeine 15 parts Citric acid 15 parts Triethylene glycol 35 parts Thiourea
40 parts 2.3-dihydroxynaphthalene 6-sulfonic acid sodium 15 parts 4-diazo-N, N-dimethylaniline chloride 1/2znC
A mixture consisting of 1,210 parts, 60 parts of zinc chloride, and 20 parts of Aerosil 300 was mixed with water to make a total volume of 1 liter, and this was coated on a support and dried to form a photosensitive layer of about 2.5 g/rr.

Comparative Example 2.3 Comparative Example 2.3 was prepared by adding 10 parts of polyvinyl alcohol and 10 parts of carboxymethyl cellulose to Comparative Example 1, respectively.

The image density, photosensitivity, and photosensitivity after half a year of each photosensitive material obtained as described above were measured as follows, and the results are shown in Table 1.

Image density: The unexposed area was developed with a commercially available dry diazo copying machine, and the reflection density was measured with a Macbeth densitometer. Photosensitivity at the time of manufacture 2 Printed at a constant speed with the above copying machine (mercury lamp light source), Example 1 Determine the exposure time for the diazo to completely decompose,
The sensitivity at this time was set to 100.

Sensitivity over time: The photosensitivity after being left in nature for six months after manufacture was measured under the same conditions as the photosensitivity at the time of manufacture, and expressed as a ratio to the photosensitivity at each time of manufacture.

(The following is a blank space) Table 1 From the above results, it can be seen that in the case of the present invention, there is almost no decrease in photosensitivity over time.

[Effects of the Invention] The present invention includes adding an emulsion of a hydrophobic polymer compound emulsified with a water-soluble polymer compound to a photosensitive liquid composition containing a diazo compound, a coupling component, and a porous inorganic pigment as main components. By coating and drying the coating on the surface of the support, a diazo-sensitive material with almost no decrease in sensitivity could be obtained by coating in a single layer.

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Claims (1)

[Claims] 1. A diazo photosensitive material produced by coating a photosensitive liquid composition containing a photosensitive diazo compound, a coupling component, and a porous inorganic pigment as main components on the surface of a support in a single layer and drying the composition. A method for producing a diazo photosensitive material, characterized in that an emulsion of a hydrophobic polymer compound emulsified with a water-soluble polymer compound is used as a binder in the photosensitive liquid composition. 2. The method for producing a diazo photosensitive material according to claim 1, wherein the hydrophobic polymer compound has a Tg of -20°C to 50°C.