JPH027457B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to an improved method for producing a photosensitive printing plate material, and more specifically, the present invention relates to a method for producing an improved photosensitive printing plate material. The present invention relates to a method for producing a photosensitive printing plate material that has the property of coming into close contact with a mask pattern within a short time when patterns are superimposed.

(Technical Background of the Invention) Photosensitive printing plate materials are produced by coating a photosensitive resin uniformly on a support, exposing it to light through a required mask pattern, and then developing and forming it to provide a printing plate material. ing. Generally, the surface of a photosensitive printing plate material, that is, the surface of a photosensitive resin, is smooth, so in order to expose and print it, the photosensitive printing plate material and the mask pattern are placed in a vacuum printing frame, which is usually made of a glass plate and a rubber sheet. The two are placed one on top of the other, and the vacuum baking frame is sealed and depressurized, which brings them into close contact.
Air tends to remain in the form of closed cells in non-peripheral areas of both, and it takes a long time to remove this air and bring them into close contact. Therefore, if exposure and printing is performed with insufficient adhesion, light will enter from an oblique direction due to the space between the two, making it impossible to reproduce an image faithful to the mask pattern. For these reasons, there has been a strong desire among plate makers to shorten the time required for adhesion.

(Prior Art) Under such circumstances, several methods have been proposed to shorten the time required for close contact.

For example, Printing Magazine, Vol. 53, No. 10, pp. 21-25 (1970) describes powdering talc onto a photosensitive printing plate material to shorten the time required for adhesion. This method is simple and has a great effect in shortening the time required for close contact. On the other hand, since talc is scattered on the surface of the photosensitive printing plate material without being fixed, it may damage or stain the mask pattern while handling the photosensitive printing plate material.
Furthermore, the talc powder falls off from the surface of the printing plate material, resulting in cracks that reduce the effect of shortening the adhesion time, which in turn worsens the working environment.

Another method consists of providing a matte layer on the photopolymer which can be removed during development. Examples of methods for providing the matte layer include:
(1) A method in which a layer made of a matting agent contained in a resin that can be removed during development is applied on a photosensitive resin (Japanese Patent Application Laid-Open No.
50-125805), (2) A method in which a resin layer that is removed during development is provided on the surface of a photosensitive resin and this layer is mechanically matted (JP 50-125805), (3)
A method in which the top layer of a photosensitive printing plate is coated with a roller having unevenness so that the convex portions are columnar with a diameter of approximately 0.05 to 0.5 mm (Japanese Patent Application Laid-Open No. 51-20307); (4) the top layer is removed during development; A method of transfer-coating a coating solution forming a coating layer from a rubber coating roll having a fine uneven pattern onto a support (Japanese Patent Laid-Open No. 51
-96604), (5) Height: 5 to 20 μm, Width: 50 to
A well-known method is to apply a coating liquid to the surface of a photosensitive printing plate to form a convex portion of 5000 μm (Japanese Patent Laid-Open No. 111102/1983). However, according to these methods, since the matte layer occupies a large contact area on the surface of the photosensitive resin, it obstructs the contact of the developer to the photosensitive resin during development, worsening the developability and prolonging the development time. It will be necessary to do so. Furthermore, since the matte layer occupies a large volume, a large amount of the matte layer dissolves into the developer, contaminating the developer and accelerating its fatigue. Furthermore, when a water-soluble resin is used as the pine layer, the resin absorbs moisture in the air, which causes deterioration of the photosensitive resin, especially when the contact area with the photosensitive resin in the pine layer becomes large. There is.

Still another method is to adhere heat-fusible fine powder onto a photosensitive resin and then fix it in a high-temperature atmosphere (Japanese Unexamined Patent Publication No. 12974/1983), or to make it adhere by contacting it with a heating roll. There is a method (Japanese Unexamined Patent Publication No. 101949/1982), but each method is characterized by fixing each fine powder without changing its volume. Since both methods require a high temperature of 140° C. or higher, the heat has an adverse effect on the photosensitive resin, resulting in disadvantages such as decreased sensitivity of the photosensitive resin, changes over time, and decreased developability. Furthermore, thermal deformation occurs not only in the photosensitive resin but also in the support, resulting in a waving phenomenon in the support. Furthermore, according to the invention described in Japanese Unexamined Patent Publication No. 55-12974, the drawback that the heating device becomes large cannot be avoided. According to the invention described in JP-A-55-101949, the heating device is improved, but apart from this point, it has the same drawbacks as the invention described in JP-A-55-12974.

As described above, raising the temperature to a high temperature has an adverse effect on the photosensitive printing plate material, so it is necessary to fix the fine powder at a low temperature. However, in order to achieve this, it is better to make the particle size of the fine powder as small as possible, but the smaller the particle size, the more likely the fine powder will agglomerate together, forming large lumps or sticking to the container wall. , it becomes difficult to handle. Therefore, it is necessary to prepare in advance a fine powder that is effective in vacuum adhesion, and to manufacture it with great care by heating it so as not to adversely affect the photosensitive printing plate material. There was a drawback.

(Object of the Invention) The present inventors have completed the present invention as a result of extensive research in order to overcome the drawbacks of the above-mentioned prior art.

In other words, the present invention (1) prevents the fine powder from forming agglomerates and adhesion to the container wall at room temperature, (2) causes less fatigue to the developer, and (3) prevents the fine powder from being subjected to rough handling. (4) A method for producing photosensitive resin plate materials that does not cause quality deterioration and shortens the vacuum adhesion time, and is aimed at developing a production method that does not adversely affect the photosensitive resin. It is.

(Structure of the Invention) The method for producing a photosensitive printing plate material according to the present invention comprises about
Melting polymer fine powder with a size in the range of 0.5 to 50 μm and particles with a smaller size (for example, if the size of the fine powder is 40 μm, if the fine particle size is smaller than 40 μm) good)
A spherical cap-shaped melt of meltable polymer is fixed and dispersed on the surface of a photosensitive printing plate material by powdering a mixture of the above on a photosensitive resin and melting the fine powder by heating. This is a method for producing a photosensitive printing plate material. The spherical cap shape here means that the part where the melt is fixed to the photosensitive material is a surface, and the part where the melt comes into contact with air is in the shape of a part of a sphere. The shape of the agglomerated melt obtained according to the present invention is shown in FIGS. 1 to 3, which are copies of micrographs. Figures 1 and 2 are reproductions of photographs with a magnification of 1000x, and Figure 3 is a reproduction of photographs with a magnification of 6000x.

The photosensitive printing plate material according to the present invention includes all photosensitive printing plate materials used for planographic, letterpress and intaglio printing.

(Fine meltable polymer powder) In the present invention, the fine meltable polymer powder for forming the melt that is fixed to the photosensitive printing plate material has a size in the range of about 0.5 to 50 μm, and
By powdering the surface of the photosensitive printing plate material and heating it, the fine powder causes a melting phenomenon, solidifies as the temperature falls, and forms a spherical hat-shaped melt, forming a photosensitive printing plate. It sticks to the surface of the material.

Preferred specific examples of the meltable polymer fine powder in the present invention include polyvinyl acetate, polyvinylidene chloride, polyethylene oxide, polyethylene glycol, polyacrylic acid, polyacrylamide,
Examples include polyacrylic acid alkyl ester, polystyrene and polystyrene derivatives, copolymers using monomers of these polymers, polyvinyl methyl ether, epoxy resins, fusible phenolic resins, polyamides, polyvinyl butyral, and the like. It is preferable that the polymers and copolymers exemplified here are soluble in the photosensitive resin developer in order to achieve the object of the present invention, so they are appropriately selected depending on the photosensitive resin developer. This is desirable. For example, when using a strongly alkaline aqueous solution as a developer, examples of polymeric substances include hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylalkyl ester, polystyrene derivatives, and fusible phenolic resins. etc. are preferably applied. When using organic solvents such as alcohols, glycols, and ketones as other developing solutions, cellulose derivatives, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetate,
Polyvinylidene chloride, polyacrylic acid, polyacrylamide, polyacrylic acid alkyl ester, polystyrene, epoxy resin, fusible phenolic resin, and copolymer containing acrylic acid, acrylamide, acrylic acid alkyl ester, and styrene as at least one monomer Combination etc. are preferably applied.

The meltable polymer fine powder used to form a melt on the surface of the photosensitive printing plate material does not have to be spherical because the melt is formed through a melting process, and even if it is amorphous, there is no problem. Does not occur.

Melts suitable for the present invention can be formed when the particle size of the fine powder is in the range of about 5 to 50 μm, particularly in the range of about 5 to 30 μm. When the diameter of the fine powder is smaller than the above range, there is little effect in shortening the vacuum contact time, and when it is larger than the above range, the reproducibility of halftone dots becomes poor.

(Fine Particles) It is necessary to select and use the above-mentioned fine powders that melt at as low a temperature as possible so as not to adversely affect the photosensitive resin layer. However, the finer the powder melts at lower temperatures, the more likely it is that agglomerates of the fine powder will form during long-term storage or melt formation, and the melt will no longer have the desired form. To prevent this phenomenon, the fine powder should have a thickness of about 1 μm or more.
This can be solved by mixing fine particles in the 5 μm range (limited to those smaller than fine powder). Since the fine particles are mixed in order to prevent the fine powder from agglomerating, it is not preferable to use it in a larger amount than the fine powder. The appropriate range is about 0.01 to 50 parts by weight, preferably about 0.1 to 10 parts by weight, based on 100 parts by weight of the fine powder. By adding fine particles, the appearance of the fine powder becomes smooth, and it has the effect of being able to be powdered uniformly.

If the amount of fine particles added is less than the above range, agglomerations of fine powder tend to occur, making it impossible to use fine powder with a low melting temperature. On the other hand, if the amount exceeds the above range, the fine powder will not agglomerate, but
The apparent melting temperature of the fine powder becomes high, making it impossible to achieve the object of the present invention.

Suitable materials for the fine particles that can be used in the present invention include silicon dioxide, diatomaceous earth, zinc oxide, titanium oxide, zirconium oxide, glass, alumina, dextrin, starch, calcium stearate, zinc stearate, polysaccharide fatty acid ester, synthetic Examples include polymers.

(Mixing of Fine Powder and Fine Particles) Approximately 0.01 to 50 parts by weight of fine particles can be mixed with 100 parts by weight of fine powder by a generally known mixing method. For example, mixing can be performed using a horizontal cylindrical mixer, a V-type mixer, a cone-type mixer, a ribbon-type mixer, or the like.

(Method of powdering and melt formation) In the present invention, in order to form a melt on the uppermost layer of a photosensitive printing plate material, a mixture of fine powder and fine particles (hereinafter simply referred to as powder) is A coating method, a fluidized dipping method, an electrostatic powder spraying method, an electrostatic dynamic dipping method, etc., is applied to a photosensitive resin that has been formed on a support in advance in a range of 0.005 to 1 g/ ^m2 , and further Preferably, it is powdered uniformly in the range of 0.01 to 0.07 g/ ^m2 , and then placed in a furnace heated to 50 to 130°C using a heat source such as hot air or an infrared heater, or powdered using heated rolls. melting bodies, especially fine powders. At this time, some of the fine powders may be integrated, and the resulting melt is fixed and dispersed on the photosensitive resin in the form of a spherical cap, thereby achieving the object of the present invention. Although the fine particles that have been in contact with the fine powder are fixed to the surface and inside of the melt, they do not have any adverse effect on the photosensitive printing plate material.

(Support for photosensitive printing plate material) The support that can be used for photosensitive printing plate material is a non-stretchable, dimensionally stable plate-like material or a cylindrical material. Those used as supports for printing plates can be used as they are. Examples of such supports include paper or paper laminated with plastic sheets such as polyethylene, polypropylene, and polystyrene, metals such as aluminum, zinc, iron, and steel, cellulose acetate, cellulose propionate,
Cellulose nitrate, polyethylene terephthalate,
polyethylene, polystyrene, polypropylene,
Plastic sheets such as polycarbonate and polyvinyl acetal, or materials obtained by vapor-depositing or laminating metal on these plastic sheets or paper are preferably used.

The supports listed here are selected and used depending on the type of printing plate. For example, most lithographic printing plates are made of aluminum plates, but a composite sheet in which an aluminum sheet is laminated on a polyethylene terephthalate film as described in Japanese Patent Publication No. 18327/1984 may also be used. As the support for the letterpress printing plate, polyethylene terephthalate sheets, aluminum plates, iron plates, etc. are preferably used.

The support may be surface-treated as necessary to improve the printing method or the adhesion to the photosensitive resin. For example, in the case of a lithographic printing plate, the surface of the support may be subjected to graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorinated zirconate, phosphate, etc., anodization treatment, or hydrophilic treatment. These treatments may be performed alone or in combination.

(Photosensitive Resin) The photosensitive resin deposited on the printing plate support includes all conventionally used photosensitive resins. For example, polyvinyl cinnamate described in Japanese Patent Publication No. 38-1492, derivatives thereof described in U.S. Pat. p-azidobenzoate of vinyl acetate, polyazidostyrene, a mixture of a diazo resin and an acrylic copolymer described in JP-A-50-30604, a diazo resin and Sierra Tsuk as described in JP-A-50-24841; as well as U.S. Patent No.
Diethyl p-phenylene diacrylate and 1,4-
In addition to negative photosensitive materials such as condensates with di-β-hydroxyethylcyclohexane, U.S. Pat.
Examples include positive photosensitive resins using o-naphthoquinone diazide compounds described in Specification No. 3046120 and Japanese Patent Publication No. 49-24361.

To coat a photosensitive resin on a support, a coating solution containing the photosensitive resin dissolved in a solvent is applied uniformly using a direct coater, reverse coater, fountain coater, etc., and then air-dried or heated. The solvent can be volatilized and the film can be deposited.

(Examples) Examples of the method for producing a photosensitive printing plate material according to the present invention will be shown and described in detail below, but the present invention is not limited in any way by these Examples.

Example 1 10% of trisodium phosphate kept at 80°C on an aluminum plate with a thickness of 0.3 mm and a size of 1000 x 800 mm.
After degreasing by immersing in an aqueous solution for 3 minutes, washing with water and leaving 70%
After immersing in nitric acid and desmatting and washing with water, 80
The sample was immersed in a 2% aqueous solution of potassium fluorozirconate at ℃ for 3 minutes, washed with water, and dried. A photosensitive liquid having the following composition was applied to this aluminum plate and dried to provide a photosensitive resin layer. The coating amount of the photosensitive resin layer when dry was 1 g/m ² .

Photosensitive liquid m-cresol-formaldehyde novolac resin 5g 1,2-naphthoquinonediazide-5-sulfonic acid ester of m-cresol-formaldehyde novolac resin 1g methanol 80g Meanwhile, phenol-formaldehyde novolac resin with a melting temperature of about 80°C Fine powder with a diameter of 5 to 20 μm, crushed with a jet mill and classified with a classifier.
A uniform mixture of 100g and 0.5g of silicon dioxide with an average diameter of 20nm was applied to the surface of the photosensitive resin using a spray gun, and then left in an infrared oven kept at 85℃ for 15 seconds, and then allowed to cool. A spherical cap-shaped melt was obtained. The amount of adhesion of this melt was 0.05 g/m ² .

When performing vacuum contact exposure, in the case of the photosensitive printing plate material obtained in this way, the time required to overlap the printing plate material and the mask pattern and bring them into vacuum contact is as follows:
It was hot in 18 seconds.

On the other hand, the printing plate material which was not subjected to granule treatment required 60 seconds or more, indicating that the effect of the present invention was remarkable.

Subsequently, both photosensitive printing plates were irradiated with ultraviolet rays from a distance of 1 m for 1 minute using a 2 kW ultra-high pressure mercury lamp through a mask pattern, and then developed with a 5% aqueous solution of trisodium phosphate. There was no difference in the sensitivity, development latitude, or tone reproducibility of each printing plate material, and there was also no difference in developer fatigue when a large number of plates were developed. Furthermore, the printing durability was also equivalent.

That is, by applying the melt according to the present invention on a conventional photosensitive resin plate material, there is no adverse effect on plate making suitability and print suitability.

Example 2 A fine copolymer powder consisting of styrene: methyl methacrylate: acrylic acid in a molar ratio of 2:2:1 was coated on the surface of a photosensitive resin on three aluminum plates obtained in the same manner as in Example 1. (5-20μm diameter) 100g
and 1 g of silicon dioxide with an average diameter of 20 nm were uniformly mixed and powdered using a spray gun. The fine powder was then melted by heating in a room at 90°C for 15 seconds, and upon cooling, a photosensitive printing plate material with a spherical cap-shaped melt fixed on the photosensitive resin was obtained. . The time required for vacuum adhesion of this product was 18 seconds. Further, exposure and development were carried out in the same manner as in Example 1, but the results were comparable to those in Example 1.

Example 3 Ten aluminum plates with a thickness of 0.3 mm and a size of 1000 x 800 mm were immersed for 1 minute in a 10% aqueous solution of tribasic sodium phosphate kept at 80°C, degreased, and washed with water.
The surface of the aluminum plate was grained by rubbing it with a nylon brush while flowing a solution containing permiston suspended in water. Next, the aluminum plate was thoroughly washed with water, and 5% of JIS No. 3 sodium silicate was kept at 75℃.
After being immersed in an aqueous solution for 3 minutes, it was washed with water and dried. Next, a photosensitive solution with the following composition was used to determine the dry weight.
A photosensitive resin layer was formed by coating at a concentration of 1 g/m ² and drying.

Composition of photosensitive liquid Copolymer of methyl methacrylate, acrylonitrile, and methacrylic acid in a weight ratio of 6:3:1
1.5 parts by weight 2-hydroxy-4-methoxybenzophenone-5-sulfonate of formalin condensate of p-diazodiallylamine 0.2 parts by weight Oil Blue - #603 (dye manufactured by Orient Chemical Co., Ltd.)
0.045 parts by weight Methanol 50 parts by weight Pulverized with a jet mill and classified with a classifier
A powder prepared by mixing 100 g of phenol formaldehyde novolac resin with a diameter of 10 to 20 μm with 0.5 g of calcium stearate with an average diameter of 500 nm was sprayed onto the above aluminum plate using a spray gun so that the adhesion amount was 0.03 g/ ^m2 . It was powdered onto a photosensitive resin. This was heat-treated in the same manner as in Example 1 to obtain a melt. This photosensitive printing plate material and a mask pattern were overlapped, and in order to perform a comparative test on the time required for vacuum adhesion, they were classified as follows according to processing conditions.

(a) After being removed from the oven (b) After being taken out of the oven and cooled, the photosensitive resin surface was wiped with a cotton glove (c) After powdering and without heat treatment (b) The same photosensitive resin surface was wiped with a cotton glove (comparative example). As a result, (a) adhered in 15 seconds, (b) in 17 seconds, and (c) in 46 seconds. It took 50 seconds for the one that was just coated with a photosensitive resin without powder treatment.

Next, from a distance of 1 m through the mask pattern for the plate in state (a) and the plate material that has not been powder treated.
Irradiated with ultraviolet light for 1 minute using a 2kW ultra-high pressure mercury lamp,
The results of developing for 15 seconds using the following developer kept at 10°C showed that the images were developed quickly, and images faithful to the mask pattern were obtained during plate making and printing, and the quality was stable.

Developer formulation Sodium metasilicate 1 part by weight Sodium lauryl sulfate 4 parts by weight Ethylene glycol monophenyl ether
6 parts by weight Water 94 parts by weight Example 4 100 g of a copolymer of styrene: methyl methacrylate: acrylic acid (molar ratio 2:2:1) having a diameter of 15 to 25 μm and an average diameter were placed on the photosensitive resin of Example 3. The adhesion amount of powder containing 2g of 1μm alumina
After powdering to a powder density of 0.06 g/m ² and heat treatment in the same manner as in Example 3, a vacuum adhesion test was conducted.

The vacuum adhesion time was 13 seconds for (a), 16 seconds for (b), and 44 seconds for (c).

Example 5 100 g of polymethacrylic acid fine powder with a diameter of 10 to 15 μm, 0.5 g of silicon dioxide with an average diameter of 100 nm, and alumina with an average diameter of 1 μm were placed on the photosensitive resin of Example 3.
A powder consisting of 0.5 g was powdered so that the adhesion amount was 0.03 g/m ² , and after performing the same heat treatment as in Example 3, a vacuum adhesion test was conducted.

The vacuum contact time was (a) 18 seconds, (b) 20 seconds, and (c) 49 seconds.

From Examples 3, 4, and 5, the time required for overlapping and vacuum-adhering the photosensitive printing plate material of the present invention and the mask pattern was shortened to around 15 seconds, and the melt was firmly fixed to the photosensitive resin. It has been found that a printing plate material of stable quality that does not come off easily, develops quickly, and is faithful to the mask pattern can be obtained.

Example 6 After graining in the same manner as in Example 3, a photosensitive solution having the following composition was applied to an aluminum plate provided with an anodized film layer using phosphoric acid as an electrolytic bath, dried, and a photosensitive resin layer was laminated.

Photosensitive liquid diethyl p-phenylene diacrylate 1,
Polyester transesterified with 4-di-β-hydroxyethoxycyclohexane 10g 1-Methyl-2-benzoylmethylene-β-naphthothiazoline 1g Phthalocyanine Blue-S-10 (pigment manufactured by Dainichiseika Chemical Co., Ltd.) 2g Hydroquinone 0.2g Methylene dichloride 350g A powder consisting of fine epoxy resin powder with a diameter of 15 to 30 μm crushed with a jet mill and 0.5 g of silicon dioxide with an average diameter of 20 μm was electrostatically sprayed onto the surface of the photosensitive resin so that the adhesion amount was 0.08 g/m ² It was powdered using a spray gun. Then, heat treatment was performed in the same manner as in Example 1 to melt the powder and obtain a spherical cap-shaped melt.

The time required to stack the thus obtained photosensitive printing plate material on the mask pattern and vacuum-adhere the plate material and the mask pattern using a vacuum contact method was 16 seconds. On the other hand, the plate material made by the conventional method without powder treatment is 60
The vacuum adhesion time was shortened to about 1/4 since it took seconds.

Next, pass the mask pattern onto the photosensitive printing plate material.
Ultraviolet rays are emitted from a distance of 1m using a 2kW ultra-high pressure mercury lamp.
Irradiated for 30 seconds. When a developer having the composition shown below was poured onto the exposed photosensitive printing plate material and the surface was lightly rubbed with absorbent cotton, an image faithful to the mask pattern immediately appeared.

The melt that was supposed to have adhered to the image had been dissolved and removed by the developer. Next, after washing the surface of the photosensitive printing plate with water and squeezing, gum arabic solution was spread over the entire surface of the plate, and it was wiped off with a soft cloth to make it desensitized and then put into a printing machine, but it could be printed without any problems. Ta.

Developer γ-butyrolactone 87g Glycerin 5g Phosphoric acid 3g Water 5g Comparative Example 1 Powdering was carried out in exactly the same manner as in Example 2, except that the amount of silicon dioxide was changed to 100g. Although it was heated after powdering, the large amount of silicon dioxide particles showed resistance to thermal conductivity, and the powder was heated at 90℃15.
The fine powder did not melt in seconds, and the temperature had to be raised to 160°C to melt it.
Although the fine powder was melted in this way, since a large amount of fine particles were used, a large amount of fine particles that were not integrated with the fine powder were directly attached to the photosensitive resin, which is not preferable because it causes mist. The time required for vacuum adhesion of the thus obtained photosensitive printing plate material was 18 seconds, but when exposed and developed in the same manner as in Example 1, development was impossible due to thermal fog development of the photosensitive resin. .

Comparative Example 2 In the case of processing in the same manner as in Example 2 except that silicon dioxide is not used, the copolymer can be powdered with a spray gun immediately after being pulverized, but as time passes, fine powder This causes a lump to form, clogging the nozzle and making powdering impossible, so it can be used when powdering is performed immediately after pulverization, but it is difficult to store it in a powdered state for a long time, making it less practical.

Comparative Example 3 In the same manner as in Example 3, a photosensitive resin layer was provided on the surface of the photosensitive resin, and 100 g of water was added to the surface of the photosensitive resin.
A solution consisting of 0.2 g of 2 g of silica gel with an average particle size of 2 μm was applied and dried to form a matte layer of 0.2 g/m ² (28 to 30 mol %).

It takes 15 seconds to vacuum-adhere the photosensitive printing plate material and the mask pattern, and the effect of shortening the vacuum-adhesion time is significant. However, even after exposure through a mask pattern and development under the same conditions as in Example 3, the developer penetrates into the photosensitive resin layer, probably because the matte layer covers the entire photosensitive resin layer. It was so slow that it was impossible to complete development in 15 seconds. The presence of this matte layer in the developer increases the fatigue of the developer. For example, it is difficult to develop 5 m ² of photosensitive printing plate material using 1 developer.

Photosensitive printing plate material according to Example 3 of the present invention (state:
In (a)), it was possible to develop 5 m ² or more with 1 of the same developer.

Furthermore, since the entire surface of the photosensitive printing plate material is covered with a water-soluble resin, the water-soluble resin absorbs moisture in the air, thereby impairing the storage stability of the photosensitive resin. For example, the storage stability is less than half that of the photosensitive printing plate material shown in Example 3.

(Effect of the invention) The advantage of the present invention is that a mixture of fine polymer powder and smaller fine particles is heated to form small protrusions made by melting the fine polymer powder on a photosensitive resin plate. The goal is to establish a method for producing excellent resin printing plate materials with good printing effects.

[Brief explanation of drawings]

The attached FIGS. 1 to 3 are reproductions of micrographs of photosensitive printing plates according to embodiments of the present invention.
In each figure, 1 indicates a spherical cap-shaped projection, and 2 indicates a photosensitive resin.

Claims (1)

[Claims] 1. Powdering a mixture of meltable polymer fine powder having a size in the range of about 0.5 to 50 μm and fine particles having a smaller size on the surface of a photosensitive resin coating. A method for producing a photosensitive printing plate material, characterized in that a spherical cap-shaped melt of a meltable polymer is fixed and dispersed on the surface of a photosensitive resin coating by heating and melting the fine powder. . 2. A patent claim in which the fine particles are selected from silicon dioxide, diatomaceous earth, zinc oxide, titanium oxide, zirconium oxide, glass, alumina, dextrin, starch, calcium stearate, zinc stearate, polysaccharide fatty acid ester, and synthetic polymer. A method for producing a photosensitive printing plate material according to item 1. 3 Approximately per 100 parts by weight of meltable polymer fine powder
The method for producing a photosensitive printing plate material according to claim 1, wherein 0.01 to 50 parts by weight of fine particles are mixed.