JPS59210444A - Photosensitive printing plate - Google Patents

Abstract

PURPOSE:To stably form a photosensitive printing plate having superior adhesive strength to an original film plate by forming a protective layer on the surface of a matting agent bonded to the surface of a photosensitive layer or directly to this surface of the layer. CONSTITUTION:A matting agent is bonded to the photosensitive layer formed on a support, and further a protective layer is formed on the matting agent to prepare a photosensitive printing plate. When an original film plate is applied to this printing plate by the vacuum contact method, since the matting agent and the protective layer roughened on the surface with the matting agent are present between the film and the photosensitive layer, air passing paths are formed between them to facilitate evacuation of the air in the middle part. As a result, the whole air present between the film and the layer can be removed securely and rapidly, and a photosensitive printing plate having superior adhesive strength to the original film plate can be thus formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to photosensitive printing plates, and in particular to improving the adhesion when performing a vacuum adhesion method in which a film base plate is brought into close contact with a photosensitive printing plate during exposure during plate making. In order to quickly perform this process, a protective layer is provided on the entire surface of the fixed matting agent and the photosensitive IJ printing plate in a photosensitive printing plate in which a manting agent that makes the surface 411 planes is fixed to the photosensitive printing original plate. related to things.

BACKGROUND OF THE INVENTION Printing plates, such as lithographic printing plates, are made from photosensitive printing plates. For example, to create a lithographic printing plate, a photosensitive printing original plate having a photosensitive layer on a support such as a surface-treated aluminum plate is created, and a film original plate of the original is applied to the photosensitive layer of the photosensitive printing original plate. A hardened area and a non-hardened area are formed on the photosensitive layer by the intensity of light corresponding to the brightness and darkness of the original image, and the unhardened area is exposed to light using a developer.
The image area and the non-image area are formed by removing the image. The image area is oleophilic and the non-image area is hydrophilic, so oleophilic printing ink adheres only to the image area.
This is transferred to a printing medium such as paper. By the way, when applying the above-mentioned film original plate, if the film original plate is exposed without being brought into close contact with the photosensitive layer, the image formed on the photosensitive layer will be affected, so it is important to ensure that this contact is made as quickly as possible. This is important in terms of work efficiency. Conventionally, a method called an 11-hole contact method has been used to bring the film original plate into close contact with this photosensitive layer. In this method, a film original plate and a photosensitive printing original plate are sandwiched between a glass plate and rubber seals 1 to 1 so that the photosensitive layer is L1″L on the film original plate, and these are supported in a vacuum baking frame. A vacuum is created between the plate and the rubber sheet to bring the film base plate and the photosensitive printing base plate into close contact.By the way, since the surface of the conventional photosensitive printing base plate is flat, the above-mentioned vacuum contact method is not suitable. According to the above, since the air between the film original plate and the photosensitive layer is removed from the periphery and the two are gradually brought into close contact from the periphery, air is removed from the center of the film and the photosensitive layer.
Therefore, it takes an extremely long time to remove this and bring the film base plate into close contact with the entire surface of the photosensitive printing base plate.

Since this reduces work efficiency, several attempts have been made to improve it.

One of the methods is to spread a solid powder such as talc on the surface of the photosensitive layer (referred to as "powdering") just before the process of attaching the original film to the photosensitive layer and exposing it to light. ), 23 (1970) II, Iino,
and Print Information 33 (11), 90 (1973) as disclosed in Ishiyama et al. According to this method, the photosensitive layer is phased (Pine 1~
) to form a gap between the film base plate and the photosensitive layer, which can be used as a passage to remove air from the center, thereby improving the vacuum adhesion of the film base plate. However, the disadvantage is that the solid powder is simply attached to the photosensitive layer, so it may fall off during handling, and the expected vacuum adhesion may not be achieved. On the other hand, when solid powder is dispersed, it scatters and blocks the air in the plate-making work room and surrounding equipment, causing various problems in the plate-making process and causing problems in the work. This caused various operational problems, including hygiene problems and the fact that it took a lot of time to clean the equipment. Also, JP-A-50-125
No. 805 discloses a dispersion in which a matting agent such as silicon dioxide and polymer particles is dispersed in a resin solution and is applied to the photosensitive layer to form Mano 1-Lj as the outermost layer. There is. Although this method can eliminate the drawbacks of the method of scattering solid powder, it has the following drawbacks in production.

In other words, photosensitive printing plates made using this method are manufactured by first preparing a dispersion in which a matting agent is dispersed in a resin solution, and then applying this dispersion onto the surface of a photosensitive printing original plate. Therefore, it is necessary to ensure that the stability of the dispersion is not impaired between the time it is manufactured and the time it is applied, and great care must be taken to ensure that the stability of the dispersion is not impaired. If this dispersion stability is impaired and, for example, the particles of the capping agent aggregate and the particle size becomes excessive, the adhesion between the film base plate and the photosensitive printing plate in the vacuum adhesion method described above will be insufficient, resulting in the resulting image line. This is because the sharpness of the image decreases. Therefore, the type of material used for the matting agent, the type of resin and solvent used in the resin solution in which it is dispersed, the storage conditions (/l, application conditions, In addition, there are significant restrictions, especially in terms of drying conditions, so there is a problem in maintaining the dispersion stability of the dispersion and always stably supplying it during coating, which makes it difficult to maintain stable productivity of photosensitive printing plates. It also means that you won't be able to do it.

OBJECTS OF THE INVENTION The first object of the present invention is to provide a photosensitive printing plate that enables production with stable productivity and has excellent adhesion to a Lylum original plate.

Structure of the Invention In order to achieve the object of the present invention, the present invention has a photosensitive layer on a support, a capping agent fixed to the surface of the photosensitive layer, and a capping agent fixed to the surface of the photosensitive layer. It is characterized in that a protective layer is provided on the surface of the agent and the surface of the photosensitive layer to which the mantle agent is not fixed.

The present invention will be explained in more detail below.

The material for the mantle agent in the present invention may be any material that maintains its solid state at least until it is exposed after the film original plate is brought into close contact with it by the vacuum contact method described above. For example, gelatin, casein, glass, glue, titanium oxide, silica gel, alumina, acid or zinc, zirconium oxide, aluminum hydroxide, aluminum silicate, gum arabic, shell powder (
Illl Eva-modified starch, soluble starch), talc, cellulose (e.g. methylcellulose, ethylcellulose,
Hydroxyethylcellulose, carboxymethylcellulose, viscose, hydroxypropylmethylcellulose, vamisu, rosin, rosin ester (methyl abietate and its hydrogenated product, diethylene glycol abietate, monoabietate, noethylene glycol), polyvinyl alcohol, polyvinylpyrrolidone, poly Vinyl acetate, polyvinylidene chloride, polyethylene oxide, polyvinyl methyl ether, polyvinyl alcohol (e.g. polyvinyl butyral, polyvinyl polymer), polyvinyl pyridine, polyacrylic acid, polyacrylic ester, polyacrylic ester, polyacrylamides, polynucleol Amides, polystyrene and its derivatives, polyamide, polyethylene, polypropylene, polyethylene terephthalate 1-1 PVC resin, urea resin, silicone resin, fluorocarbon resin, epoxy resin, phenol resin (e.g. novolak type phenol resin, 1-1)
/ Sole type phenolic resin, specifically ~phenol-formaldehyde resin, cresol-formaldehyde resin, resorcinol-henzaldehyde resin, pt-butylphenol formaldehyde resin, pt-aminophenol formaldehyde resin, p-octylphenol formaldehyde resin , p-phenylphenol-
Formaldehyde resin) as well as various copolymers (e.g. meccrylic acid-methyl meccrylate, methyl methacrylate-butyl methacrylate-acrylic acid, methyl meccrylate-divinylstyrene, ethylene-propylene, ethylene-vinyl acetate, methyl meccrylate-ethyl Acrylate - methacrylic acid, methyl methacrylate
1.-ethyl acrylate-sodium acrylate, styrene-methyl methacrylate-1.-acrylic acid, styrene-butyl meccrylate-acrylic acid, styrene-maleic anhydride, styrene-ammonium meccrylate salt-ethyl acrylate methyl methacrylate. Cucrylate). Polymers of these monomers can be obtained by various polymerization methods such as solution polymerization, suspension polymerization, and emulsion polymerization. The material for the mantle agent may be soluble or insoluble in the developer of the photosensitive printing plate, and the solid particles of the mantle agent may be mixed with particles of each material in one or two other materials. It may be coated with any of the above materials.

The shape of the solid particles of the matting agent and its distribution density on the surface of the photosensitive layer side are such that the mantle agent is fixed to the surface of the photosensitive layer side, a protective layer to be described later is formed, and the film original is formed by the vacuum adhesion method. A material is selected that allows air to be removed from between the two when stacked on top of each other. For example, in addition to spherical, hemispherical, elliptical, semi-elliptical, cylindrical, elliptical cylindrical, and prismatic shapes, a variety of irregularly shaped tubes such as those obtained by pulverizing materials using a ball mill, shet mill, etc. can be used. In addition, the size of the particles of the matte is preferably 2 to 100 μm in diameter when projected, particularly 3 to 5 μm in diameter.
A diameter of 0μ is preferred.

Further, the height of each solid particle of the mantle agent from the surface of the photosensitive layer to which it is fixed is preferably 1 to 40 μm, particularly 2 to 20 μm.
μ is preferred. Further, the ratio of all particles of the matting agent to the surface of the photosensitive printing plate is preferably 0.3 to 12%, particularly preferably 0.5 to 10%. Particularly from the viewpoint of the clarity of the printed image, it is desirable that the centerline surface roughness Ra is 20 μm or less when a protective layer, which will be described later, is formed on the matting agent.

The protective layer of the present invention is for protecting the surface of the photosensitive printing plate, and prevents the capping agent from peeling off or scratching the photosensitive layer side during handling of the photosensitive printing plate. west,
Alternatively, it protects the 1iVIi line portion of the completed printing plate from being worn out due to repeated printing. For the former purpose, the protective layer may be one that dissolves in the developer, but
In the case of the latter protective layer, one that is insoluble in a developer is used. In the case of a protective layer that is soluble in a developing solution, the above-mentioned capping agent should be one that does not dissolve in the developing solution. When printing ink, it is preferable to use one that has an affinity for printing ink in terms of ink receptivity. Further, when a protective layer that is easily soluble in the developer is used, it is preferable that the material used for the protective layer has an affinity for the printing ink. In addition, since the printing ink is oleophilic and hydrophobic, it is necessary to select the phase of the surface coating layer that also has these properties. From this point of view, the protection material 1 is selected, but since there are many types of developing solutions, for example, the moon phase corresponding to these specific types is selected.

Suitable materials include, for example, seratin casein, glue, gum arabic, starches (e.g. modified starch, soluble R powder), celluloses (e.g. methyl cellulose, ethyl cellulose, hydroxyconityl cellulose), polyhinyl alcohol, Polyvinylpyrrolidone, polyvinyl acetate, polyvinylidene 1 colyte,
polyethylene oxide, borihinyl methyl ether,
Polyvinyl acecool (e.g. polyvinyl butyral, polyvinyl formal), polyvinylpyricine, polyacrylic acid, polyacrylic ester, polyacrylic ester, polyacrylamides, polymethacrylamides, polystyrene and its derivatives, polyamide, polyethylene, polyvinyl I-copylene, polyconylene la-lefthale-1, vinyl chloride resin, urea resin, silicone resin, fluorocarbon resin, epoxy resin, phenolic resin (e.g. Nohorasoku type phenol resin, resin type phenol resin) and various copolymers (e.g. methacrylic acid) -Methyl methacrylate, methyl methacrylate-butyl methacrylate-
1-monoacrylic acid, methyl meccrylate 1-dihinyl styrene, conytylene-bugopyrene, ethylene-hinyl acetate, methyl meccrylate-ethyl acrylate meccrylic acid, methyl methacrylate-ethyl acrylate-sodium acrylate , styrene-methyl methacrylate-acrylic acid, styrene-butyl methacrylate-acrylic acid, sunalene-maleic anhydride, styrene-
ammonium methacrylate salt (ethyl acrylate-1-1-methyl methacrylate). These seven polymers can be synthesized by solution polymerization, '. ``f!./!ii1 Polymerization and emulsion polymerization tubes Those obtained by various polymerization methods can be used.The above-mentioned monthly yields may be used in combination of two or more types.

The coating amount of the above-mentioned protective layer is preferably 0.01 to 5 g/i and particularly preferably 0.05 to 5 g/m in terms of dry coating. The surface of this protective layer needs to be rougher than the surface of the photosensitive printing plate without a matting agent and protective layer from the viewpoint of adhesion to the original film plate by the vacuum adhesion method described above, but it is necessary to make the surface of the printing plate rougher. From the viewpoint of the sharpness of the printed image when printing is performed with these still attached to the part, it is preferable that the center surface roughness R a is 20 μm or more.

In order to fix the mantle agent and form the protective layer, it is preferable to partially fix the mantle agent to the photosensitive layer side surface of the photosensitive printing original plate, which will be described later, and then provide the protective layer. A matting agent can be applied to the photosensitive layer by spreading and fixing a solid powder thereon, or by spraying or coating a solution or dispersion of the above material. As a method of dispersing, for example, J.
J Sokol, R. C Hendry Sokson, Plastinok Engineering Handbunok, P. 426P. 431 (1
976) (J., J. Sokol a
nd RC. Hendrickson P
lasticEng. Handbook (1976)
Fluidized F-bed (Fluidi
-zed bed) In addition to electrostatic spray, electrostatic fluidized head, etc., methods using air spray, brush, puff, etc. are used. The amount of mantle agent to be sprinkled or applied is 1 to 10 solid particles per 1 mm of the surface of the photosensitive layer.
00 pieces is appropriate, and 5 to 500 pieces is preferable. The solid particles fixed to the surface of the photosensitive layer are generally randomly distributed.

The following method is used to fix the scattered or coated solid particles to the surface of the photosensitive layer.

(1+ A method of thermally melting at least a portion of the solid powder particles and thermally fusing them to the surface of the photosensitive layer side. For example, after scattering the powder particles, the photosensitive printing original plate is heated and the powder particles are heated on the photosensitive layer side. The portion that is in contact with III!I!L7 is melted and fixed.Alternatively, during the above-mentioned scattering, the powder particles are passed through a hot atmosphere to thermally melt the powder particle surface and fixed to the photosensitive layer side surface.

F2) A method in which a small amount of powder particles (some of them are dissolved in a solvent and fixed to the surface of the photosensitive layer side. For example, in the process of manufacturing a photosensitive printing original plate, the photosensitive layer described later is coated on a support and dried. At the time of exposure, powder particles are sprinkled on the photosensitive layer (especially preferably during lapse drying) when there is still sufficient solvent remaining in the photosensitive layer, and the residual solvent dissolves a portion of the dispersed powder particles and is exposed to light. Attach it to the sexual layer side.

Although the dry powder was sprinkled in the above method, the following method in which the powder is melted or dispersed and then spread and fixed can also be used.

(3) A method in which a solution or dispersion in which powder particles of a cloak agent are melted or dispersed is sprinkled, and then dried and fixed.

The following methods can be used to apply the solution or dispersion.

(4) A matting agent/81W or a dispersed liquid is stored and held in the recess of a roll having a partially recessed part. This is applied directly to the surface of the photosensitive layer side or via another coach roll. Method.

Details of the method (1) above and other details related thereto are described in, for example, Japanese Patent Application Laid-Open No. 12974/1983. Materials for the pine 1 thickening agent suitable for this method include those listed above, such as polyvinyl acetate, polyvinylidene chloride, polyethylene oxide, polyconytylene glycol, polyacrylic acid, polyacrylamide, polyacrylic ester, polystyrene, Examples include polystyrene derivatives, polyvinyl methyl ether, epoxy resins, phenol resins, polyamides, polyvinyl butyral, and copolymers containing one monomer unit constituting these polymers.

Details of the method (2) above and other details related thereto are described in, for example, Japanese Patent Application Laid-Open No. 12974/1983. The cloak agent 4A-1 suitable for this method includes:
For example, polysaccharides such as gum arabic, cellulose, and starch;
Consisting of polyvinylpyrrolidone, polyhinyl alcohol, polyvinyl acetate, polyacrylic acid, polyacrylamide, polyacrylic ester, polystyrene, polystyrene derivatives, polyvinyl methyl ether, epoxy resin, phenol resin, polyamide, polyvinyl butyral, and polymers thereof Copolymers containing one monomer unit may be mentioned.

Details of the method (3) above and other details related thereto are described in, for example, Japanese Patent Laid-Open No. 57-34.558. Mantle materials suitable for this method include (a) at least one monomer selected from styrene, styrene derivatives, ethyl methacrylate, methyl methacrylate, and acrylonitrile; (b) acrylic acid alkyl ester (alkyl has 2 to 10 carbon atoms); At least one monomer of methacrylic acid alkyl ester (alkyl group has 4 to 10 carbon atoms); Examples include copolymers containing at least one monomer of maleic acid in the form of an ammonium salt, and itaconic acid in which part or all of it is an ammonium salt.

The method (4) above and other details thereof are described in, for example, Japanese Patent Laid-Open No. 51-9.6604.

Since the makeup agent can be fixed in this way, the above-mentioned protective layer is provided thereon. As this method, various conventionally known methods can be used, and preferably a method using a solution or dispersion of the material of the protective layer is preferred. This material has been described above, but various solvents for the solution of this material can be selected depending on the material used, such as water, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethoxyethyl acetate-1, methoxyethyl acetate, etc. can be mentioned. The solution or dispersion is applied to the photosensitive layer and dried to form a protective layer, and examples of the coating method include a doctor blade method, a slide dropper method, and a curtain coating method.

In this manner, the Mann 1 to 1 agent is fixed to the photosensitive layer side of the photosensitive printing original plate having the photosensitive layer described below on the support described below, and the protective layer described above is further formed to complete the photosensitive printing plate. When a photosensitive printing plate of ζ is operated according to the above-mentioned vacuum adhesion method, a matting agent and a protective surface roughened by the matting agent are formed between the film base plate and the photosensitive layer side in the overculm state where air is removed. Because of the intervening layer, a passage for air to escape is formed between the two, making it easier for air to escape from the center. In this way, all the air between the film original plate and the photosensitive layer side can be removed reliably and quickly, and the two can be brought into close contact. After this, it is exposed and printed. Then, the burnt photosensitive printing plate is immersed in a developer and the undissolved portion and /8-dissolved portion generated by irradiation of the photosensitive layer side are dissolved, leaving the undissolved portion and dissolving the dissolved portion. The capping agent and protective layer fixed to the photosensitive layer side of the dissolving part are removed together with the photosensitive layer into the developer, while the capping agent and protective layer fixed to the photosensitive layer side of the non-dissolving part are removed by the developer. If it is insoluble in the liquid, it remains as it is and serves as a protective layer against abrasion of the image area during printing.

In this case, the protective layer should be one that has an affinity for printing ink. In addition, if this retaining eJN is soluble in the developer, the matting agent will remain in the image area, and if it is insoluble, the ink will adhere to it during printing, so the affinity for the ink and the photosensitive layer will increase. Use a matting agent with good adhesion to the sides in advance. If the capping agent is soluble in the developer, such consideration is not necessary. In this way, a printing plate is produced in which the non-dissolved portions are the image areas and the dissolved areas are the non-image areas. When printing is performed using this printing plate, the ink receptivity of the printing ink can be avoided in the case of a protective layer or capping agent having an affinity for the printing ink.

The photosensitive printing plates according to the present invention include those having a resin layer on the photosensitive layer, and further provided with the above-mentioned matting agent and protective layer.

The photosensitive printing plates formed in the above manner include various types of printing plates such as lithographic, letterpress, and intaglio plates.The photosensitive printing plates have a photosensitive layer on a support as described above. The photosensitive layer side surface of the original plate has the above-mentioned capping agent and protective layer in this order, and the protective layer covers the area where the matte layer is present,
It is provided over the entire surface regardless of where it is not present.

The photosensitive printing original plate used in the present invention has a photosensitive layer as described below on a support, and a conventionally known plate-like support is used as the support. These are appropriately selected depending on the purpose of use of the photosensitive printing plate, the method of use, the cost of clothing, etc. Examples of materials for the 1 support ball and 5 objects include paper,
Examples include plastics (including paper laminated with plastic) and metals (including paper or plastic with metal vapor-deposited and laminated).

Examples of the above-mentioned plastics include polyethylene, polyethylene terephthalate, polypropylene, polystyrene, polyvinyl acecool, polycarbonate, nitrocellulose, diacetylcellulose, and triacetylcellulose.

In addition, the above metals include aluminum (including alloys),
Examples include zinc, copper, iron, etc. Among these, aluminum is preferable when the material is lithographic, and aluminum, zinc, iron, and polyethylene terephthalate are preferable when it is letterpress. The surface of the support may be treated in advance depending on the cost of printing, etc. If the material is a lithographic plate, it is treated to make it hydrophilic. This hydrophilic treatment method can be appropriately selected depending on the aluminum quality of the surface of the support. When a metal such as aluminum is used as the support surface, roughening treatment, anodizing treatment, immersion in a fluorozirconate aqueous solution, immersion in a silicate aqueous solution, immersion in a phosphate aqueous solution are possible. A method of doing so is preferred. These various hydrophilic treatment methods may be combined, and examples thereof include a method in which surface roughening treatment and immersion in a sodium silicate aqueous solution are sequentially performed (described in detail in U.S. Pat. No. 2,714,066), and anodizing. A method of sequentially performing immersion in a treated silicate aqueous solution (
(described in the specification of US Pat. No. 318,146) and the like. - When the material of the surface of the force support is plastic, a method known as so-called silver salt photography can be used. For example, methods include electric discharge treatment, chemical treatment, laser treatment, and further providing an undercoat.

As the photosensitive composition constituting the photosensitive layer provided on the support described above, conventionally known ones can be used. This photosensitive composition contains a photosensitive substance as an essential component, and this photosensitive substance includes those that cause a difference in the solubility of the photosensitive layer in a developer upon exposure, and those that cause intermolecular adhesion before and after exposure. Those that cause a difference in strength, and those that cause a difference in the affinity of the photosensitive layer for water and oil depending on exposure can be used. Typical examples will be explained below.

First, quinonediazide-type positive photosensitive substances such as the conventionally known 0-naphthoquinone cyasito compound are mentioned.
The 0-quinonediazide compound is a compound having at least one O-quinonediazide group, preferably an 0-benzoquinonediazide group or an 0-naphthoquinonediazide group, and is a compound having various known structures, such as those by J. Koser [1
-i g k+t 3ensitivc Syst
emsJ (J-ohn Wiley&5ons,
Inc., discontinued in 1965), pages 339-353. Particularly suitable are esters of various hydroxyl compounds and O-naphthoquinonediazide sulfonic acid. Preferred hydroxyl compounds include condensation resins of phenols and carbonyl group-containing compounds, particularly resins obtained by condensation in the presence of an acidic catalyst. Examples of the phenols include phenol, resorcinol, cresol, pyrogallol, and the like. Examples of the carbonyl group-containing compound include aldehydes such as formaldehyde and benzaldehyde, and ketones such as acetone.

Especially phenol/formaldehyde resin, cresol/
Bormaldehyde resin, pyrogallol acetone resin,
Resorcinol/penzaldehyl='41 fat is preferred. Typical specific examples of the 0-quinonediazide compound include benzoquinone-(1,2)-diazide sulfonyl chloride 1 or natuquinone-(L,2)-diazide sulfonyl chloride and phenol-formaldehyde resin or cresol-formaldehyde resin. sulfonic acid esters of nathoquinone-(1,2)-diazidosulfonyl chloride and pyrogallol acetone resin as described in U.S. Pat. No. 3,635,709;
Condensate of naphthoquinone-(1,2)-diazide-(2)=5-sulbonyl chloride and resorcinol-benzaldehyde resin described in JP-A-56-1044, JP-A-55-76346 Other useful O-quinonediazide compounds include the ester compound of naphthoquinone-(],2)-diazide-(2)-5sulfonyl chloride and resorcinol-pyrogallol-acetone copolycondensate described in JP-A No. Showa 50-11750
A polyester having a hydroxyl group at the end described in Publication No. 3 is esterified with 0-naphthoquinonediazide sulfonyl chloride, JP-A-1988-
Pomopolymers of p-1 nitroxystyrene as described in Japanese Patent No. 113305 or copolymers of this and other copolymerizable monomers with O-naphthoquinonediazide sulfonyl chloride subjected to an esterification reaction, etc. can be mentioned. The content of these O-quinonediaside compounds is preferably 5 to 80% by weight, particularly preferably 10 to 50% by weight, based on the total solid content of the photosensitive composition.

Such quinone diazide type positive photosensitive materials can be used in combination with alkali-soluble resins (fats) as binders if necessary.As alkali-soluble resins, phenols and ketones or aldehydes can be used in combination with acidic catalysts. Preferably, the phenols are bound in the presence of phenols such as phenol, cresol and
1tji: 1M phenol and the like. Examples of the aldehydes include acetaldehyde and formaldehyde, with formaldehyde being preferred. Acetone is preferred as the ketone.

Preferred alkali-soluble resins include, for example, phenol-bormaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate resin described in JP-A-55-57841, and JP-A-55-127553. A copolycondensate resin of p-substituted phenol and phenol or cresol and formaldehyde as described in the publication,
Resorcinol-henzaldehyde resin, condensate of polyhydric phenols such as pyrogallol-henzaldehyde resin and benzaldehyde, pyrogallol-resorcin-ace I
Examples include copolycondensates of polyhydric phenols and acetin resins, such as xylenol formaldehyde resins. The content of these alkali-soluble resins is preferably 30 to 90% by weight based on the total solid content of the photosensitive composition, particularly 5% by weight.
0 to 85% by weight is preferred.

Another photosensitive material that can be used is a diazo resin typified by a condensate of an aromatic diazonium salt and formaldehyde. Particularly preferred are salts of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde, such as reaction products of hexafluorophosphates, tetrafluoroborates, perchlorates or periodates with the above condensates. Diazo resin inorganic salt, U.S. Patent Nos. 3 and 3
Examples include diazo resin organic salts which are reaction products of the above condensates and sulfonic acids, as described in No. 00°309. Additionally, diazo resins are used with preferred binders. As such a binder, various polymeric compounds can be used, but preferably, JP-A No. 5
Heavy substances having an aromatic hydroxyl group as described in Publication No. 4-98613, such as N-(4-hydroxyethyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, o-, m-, or p-Hitro21
- Copolymers of cystyrene, o-, m-, or p-hydroxyphenylnotacrylate, etc., with other monomers, hydroxyethyl as described in U.S. Pat. No. 4,123,276. Polymers containing acrylate units or hydroxyethyl methacrylate-1 units as the main repeating unit, natural resins such as sheraclodin, polyvinyl alcohol, polyamide resins described in U.S. Pat. No. 3,751,257, U.S. Patent No. 3.
These include linear polyurethane resins described in No. 660.097, tuclated polyvinyl alcohol resins, epoxy resins condensed from bisphenol 8 and epichlorohydrin, celluloses such as cellulose acetate and cellulose acetate tuclate.

Still other photosensitive materials include photosensitive polymers containing -CH=CH-C- as a photosensitive group in the polymer main chain or side chain, such as 1 polyesters, boria%rF, and polycarbonates. Those containing it as the main ingredient are also suitable. For example, the photosensitive polyester obtained by the condensation of phenylene diethyl acrylate with hydrogenated bisphenol A and triethylene glycol as described in JP-A-55-40415'H;
Examples include photosensitive polyesters derived from (2-properidene)malonic acid compounds such as cinnamylidenemalonic acid and difunctional glycols, as described in No. 956,878.

Aromatic azide compounds in which the azide group is bonded directly or via a carbonyl group or a sulfonyl group to an aromatic ring are also used as other photosensitive substances. For example, polyazidostyrene as described in U.S. Pat. Reaction products of sulfanyl chloride and unsaturated hydrocarbon polymers, as well as Japanese Patent Publications No. 43-21067 and 4. '4-
No. 229, No. 44-22954, No. 45-24915
Polymers containing sulbonyl azide or carbonyl azide, as described in each publication of the above-mentioned publication, may be mentioned.

Furthermore, as another photosensitive substance, a photopolymerizable composition comprising a photopolymerizable unsaturated compound is used.

Advantages of the Invention As explained above, according to the present invention, the capping agent and the protective layer are provided separately, and there is no need to use a resin dispersion of a matting agent as in the past, so that the photosensitive printing plate is Stable production is possible. In addition, since the protective layer only needs to be coated with a resin solution, the amount of coating may be as small as it can maintain skin crotch-forming ability. It is necessary to increase the amount of resin in the dispersion medium to some extent due to the physical properties of the material of the matting agent, etc. Therefore, compared to photosensitive printing, it is not possible to increase the amount of resin applied. It is possible to reduce the deterioration in the developability of the plate. In addition, since the photosensitive printing plate of the present invention has a protective layer on the pine agent, there is no need for the pine agent to fall off unnecessarily when the photosensitive printing plate is handled. . Furthermore, the occurrence of scratches that often occur during handling of photosensitive printing plates can be reduced. Furthermore, if the Man 1 agent or the protective layer, or both, remain in the image area of the printing plate after development, using a material that has good affinity with the printing ink will improve the ink adhesion of the ink. Sex can also be improved.

EXAMPLES Examples of the present invention are shown below, but the present invention is not limited thereto.

Example 1 An aluminum plate was degreased by immersing it in a 20% aqueous solution of sodium phosphate, and the surface was roughened by electrolytic etching.Then, the aluminum plate was immersed in a sulfuric acid solution with anodic acid ('Ij L), and then immersed in a sodium silicate solution. A photosensitive solution having the following composition was applied onto this aluminum plate using a rotary coating machine, and
It was dried at °C for 3 minutes to obtain a photosensitive lithographic original plate. The coating amount after drying was 2.7/l.

Esterified product of naphthoquinone-(L2)-diazido-5-sulfonic acid chloride and m-cresol formaldehyde resin (condensation rate 25 mol%)
3.5 gm-cresol formaldehyde resin 8
．． 0g naphthoquinone-(1,2)-diazide'-4-sulfonic acid chloride F' O, 15gp~
Esterified product of octylphenol formaldehyde resin and naphthoquinone-(1,2)-diazide-5-sulfonic acid chloride (condensation rate 50 mol%) 0.1
2g oil blue #603. (manufactured by Orient Chemical Industry Co., Ltd.) 0.2 g ethylene glycol monconityl ether 100 g
As a matting agent, styrene-methyl methacrylate-acrylic acid (40:40:20 ratio) was ground with a ball mill and classified with a classifier (zigzag classifier manufactured by Albime).
Copolymer Particles' 1 - 7μ) Powder particles were spread with a spray gun and fixed by exposure to an air bath at 150'C for 5 seconds. Then, a resin solution having the following composition was uniformly applied to the surface of the photosensitive layer and dried to form a photosensitive lithographic printing plate having a protective layer. The amount of the protective layer was 0.37 g/m.

Methyl methacrylate-ethyl acrylate-methacrylic acid copolymer 2.0g (2
5: 50: 25 molar ratio) 100 g of 2% ammonia water A positive original was placed on the photosensitive layer side of the photosensitive lithographic printing plate prepared in this manner using the air contact method, and then heated using a 2KW metal halide lamp (Iwasaki). Idle fin 20 manufactured by Denki Co., Ltd.
00) as a light source for 80 seconds from a distance of 1 m, the plate was immersed in an aqueous solution of 4% sodium silicate and developed at 25° C. for 45 seconds to obtain a lithographic printing plate.

Then, when this printing plate was printed on a Manfusesoto printing press, many printed matter with clear images were obtained.

Example 2 Photosensitivity was carried out in the same manner as in Example 1, except that styrene-butyl meccrylate-acrylic fi (40:40:20 molar ratio) copolymer (particle size 6-15μ) was used as the powder particles for scattering. The lithographic printing plate was IM'd. Development and printing were carried out in the same manner as in Example 1, and the same results as in Example 1 were obtained.

Example 3 Resin for protective layer? A photosensitive lithographic printing plate was obtained in the same manner as in Example 1, except that a resin solution having the following composition was used as g liquid, and development and printing were carried out in the same manner as in Example 1 to obtain the same results as in Example 1. Ta.

(Resin solution) Borynyl butyral 1 g Chloroborum 100 g Example 4 Polystyrene (average molecular weight 15
A photosensitive lithographic printing plate was obtained in the same manner as in Example 2 except that 0,000> (particle size 2 to 10 μ) was used, and then development and printing were performed. As a result, the same results as in Example 2 were obtained. .

Example 5 A photosensitive lithographic printing resin was obtained in the same manner as in Example 3, except that alumina (average particle size: 7 μm) was used as the powder particles for scattering, and then development and printing were performed. As a result, the same results as in Example 3 were obtained. Got the results.

Example 6 An aluminum plate was degreased by immersing it in a 20% aqueous solution of sodium phosphate, roughened by an electrolytic 7-ching method, anodized in a sulfuric acid solution, and then immersed in a sodium silicate solution. l
? A sealing treatment was performed using a pore sealing process. A photosensitive solution with the following composition was applied onto this aluminum plate using a rotary coating machine,
It was dried at 85°C for 3 minutes to obtain a photosensitive lithographic printing original plate.

The coating amount after drying was 2.0 g/m (Photosensitive liquid composition) Copolymer Δ 5. Og diazo resin B O, 5g Jurimer AC-1OL 0.1 g (manufactured by Nippon Pure Chemical Industries, Ltd.) Victoria Pure Blue BOH 0.1 g (manufactured by Hodogaya Chemical Co., Ltd.) Ethylene glycol phenyl ether 100 ml (coating solvent) However, the above copolymer For coalescence A, a molar ratio of p-hydroxyphenylmethacrylamide/acrylonylyl/ethyl acrylate/methacrylic m=10/30/60/6 was dissolved in methyl cellosolve, and 65% of the mixture was dissolved in a sealed tube purged with nitrogen.
The mixture was heated at °C for 10 hours, and after the reaction was completed, the reaction solution was poured into water with stirring, and the resulting white precipitate was filtered and dried. Diazo resin B was produced by mixing a 5% by weight aqueous solution of diazo resin (product name E, H, C Co., Ltd. D-012) and an aqueous solution of ammonium fluorophosphate of 10% by weight at room temperature. Absorb and filter the precipitate, 30-40
It is a hexafluorophosphate obtained by drying under reduced pressure at °C.

The weight average molecular weight of the copolymer was 80,000, and when the molecular weight distribution of the diazo resin was measured by gel vermicone chromatography (GPC), it was found that 3m or less was 93 mol% of the total. .
A styrene-maleic anhydride co-polymer (50:50 molar ratio) (particle size: 1 ~7μ) Particles were dispersed with a spray gun and fixed by exposing them to an air bath at 150°C for 5 seconds. Then, a resin solution having the following composition was uniformly coated on the surface of the photosensitive layer and dried to obtain a 1M photosensitive lithographic printing plate having a protective layer. The amount of resin film was 0.20 g/rt.

(Resin/8 liquids) Polyacrylic acid 1.0g water
10
A negative original film was closely adhered to the photosensitive layer of the It3 photosensitive lithographic printing plate obtained in the manner described above, and the 2 kW metal halide lamp was used as the light source.
Exposure to light for seconds, then heat at 25°C at 14°C using a developer with the following composition.
Developing was carried out for 5 seconds to obtain a lithographic printing plate.

(Developer composition) Ethylene glycol phenyl ether 160g Jetanolamine 70g Bionin Δ-44B 50g (1 Umoto Yushi Co., Ltd. Ding) Water
When this printing plate was then printed on an Offsen 1 to Inniri I1 machine, many prints with clear images were obtained.

Example 7 Silica gel (average particle i10) was used as powder particles for dispersion.
A photosensitive lithographic stamp 51; 1 plate was obtained in the same manner as in Example 6, except that the same method as in Example 6 was used, followed by development and printing, and the same results as in Example 6 were obtained (U.

Example 8 A photosensitive lithographic printing plate was prepared in the same manner as in Example 5, except that titanium oxide (average particle size 2 to 10 μm) was used as the particles for dispersion, and the following was used as the resin/8 liquid for the protective layer. obtained,
The results of development and printing were the same as in Example 5.

(Resin solution) Ethylcellulose ig
-xyl group content 49%) Toluene 100g Comparative Example 1 A dispersion prepared as below was applied on the photosensitive layer of a photosensitive lithographic printing original plate prepared in the same manner as in Example 8,
After drying, a photosensitive lithographic printing plate having protection 1- containing a dispersed matting agent was obtained. The film amount of the protective layer is o, 4o
g/rrr.

(Minute Wi, Preparation of Liquid) Titanium oxide (particles Z 2 to 10μ) was added to the resin solution used in Example 8, stirred for 30 minutes with a homogenizer, and then left to stand for 2 hours.

The photosensitive planographic printing plate thus obtained was exposed and developed in the same manner as in Example 8 to obtain a planographic printing plate. When this printing plate was then subjected to shadow printing on an offset printing machine, the area of the halftone dots became uneven and the shape of the halftone dots became rough. This is considered to be because the dispersion stability of the dispersion liquid was poor, and larger particles were produced due to agglomeration.

From an electron micrograph of the surface of the photosensitive lithographic printing plate prepared to 1M as described above, titanium oxide particles having a particle size distribution of 2 to 500 μm were observed on the surface of the photosensitive layer.

Comparative Example 2 A dispersion prepared as described below was coated on the photosensitive layer of a photosensitive lithographic printing original plate prepared in the same manner as in Example 5, and dried to form a photosensitive layer having a protective layer containing a mantle agent dispersed therein. A lithographic printing plate was obtained.The amount of protective I-biased film was 0.2 g/n.

(Preparation of dispersion liquid) 0.2 g of alumina (
(average particle size: 7 μm) was added thereto, stirred for 30 minutes using a homogenizer Q trowel, and then allowed to stand for 2 hours.

The photosensitive planographic printing plate thus obtained was exposed and developed in the same manner as in Example 5 to obtain an iM planographic printing plate.

When this printing plate was then printed on an offset printing machine, the area of the fine dots became non-uniform and the shape of the halftone dots became rough. This is considered to be because the dispersion liquid prepared above had poor dispersion stability and large particles were produced.

Electron 1 on the surface of the photosensitive lithographic printing plate subjected to iM as described above
7! i From the microphotograph, it has a particle size distribution of 1 to 200μ7
Alumina particles were observed on the surface of the photosensitive layer.

Comparative Example 3 A dispersion prepared as below was applied to the second photosensitive layer of a photosensitive lithographic printing original plate prepared in the same manner as in Example 6.
This was dried to obtain a photosensitive lithographic printing plate having a protective layer containing a dispersed matting agent. The amount of protective layer is 0.25 g
/ m.

(Preparation of dispersion liquid) 0.2 g of silica gel (
After stirring with a homogenizer for 30 minutes, the mixture was allowed to stand for 6 hours.

The thus exposed photosensitive lithographic printing plate was exposed and developed in the same manner as in Example 6 to obtain a lithographic printing plate. Then, when this printing plate was printed on an offset printing machine, the area of the halftone dots became non-uniform, and the shape of one point t, rI' was rough. This is considered to be because the dispersion stability of the dispersion liquid was poor and large particles were generated.

From the microscopic photograph of the surface of the photosensitive lithographic printing plate obtained in the above, silica gel particles having a particle size of 2 to 500 μm were observed on the surface of the photosensitive layer.

Invitation 1 Kiki Graduation Compensation Akii Ei Condolences Patent applicant Konishiroku Photo Industry Co., Ltd. Agent Yoshimi Kuwahara

Claims (1)

[Claims] (1,) A photosensitive layer that has a photosensitive layer on a support and has a capping agent fixed to the surface of the photosensitive layer, and the surface of the fixed capping agent and the photosensitive layer to which the capping agent is not fixed. A photosensitive printing plate characterized in that a protective layer is provided on the surface of the sexual layer side.