JPS59211044A - Photosensitive printing plate - Google Patents

Abstract

PURPOSE:To reduce the exhuastion of a developer by using a matting agent having an affinity for printing ink and insoluble in the developer as a matting agent stuck to the surface of the photosensitive layer of a photosensitive printing plate. CONSTITUTION:A matting agent having an affinity for printing ink and insoluble in a developer is used as a matting agent stuck to the surface of a photosensitive layer. The matting agent is ethylcellulose, rosin, rosin ester, polyvinyl acetate, polyvinylidene chloride, polyvinyl acetal, polyacrylate, polymethacrylate, polystyrene, a polystyrene deriv., polyamide, polyethylene, polypropylene or polyethylene terephthalate.

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. A matting agent for roughening the surface of a photosensitive printing original plate is fixed to the photosensitive printing original plate in order to quickly perform printing, and it relates to a mantle agent that has an affinity for printing ink and does not dissolve in a developer.

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. The photosensitive layer is exposed to light to form hardened areas and non-hardened areas on the photosensitive layer depending on the intensity of the light corresponding to the brightness and darkness of the image on the original, and this is treated with a developer to dissolve the hardened areas that do not melt into the image areas and melt them. The non-cured area is made into a non-image area. Since the image area becomes lipophilic and the non-image area becomes hydrophilic, the oleophilic printing ink adheres only to the image area and is transferred to the printing material 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 blurred, so how to do this contact firmly and quickly is a key factor in work efficiency. It is important in this respect. Conventionally, a vacuum adhesion 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 a rubber sheet so that the photosensitive layer overlaps with the film original plate, and these are supported by a vacuum printing frame, and then the glass plate and the rubber sheet are The film original plate and the photosensitive printing original plate are brought into close contact by creating a vacuum between them. By the way, since the conventional photosensitive printing original plate has a smooth surface, according to the above-mentioned vacuum adhesion method, the air between the film original plate and the photosensitive layer is removed from the periphery, and the adhesion between the two is established at this periphery. Since the process is carried out gradually, it is difficult to remove the air from the center between the two, and it takes an extremely long time to remove the air and bring the film original plate into close contact with the entire surface of the photosensitive printing original plate. This reduces work efficiency, so it is not possible to improve it (some attempts have been made).

One of these methods is a method in which a solid powder such as talc is sprinkled on the surface of the photosensitive layer (referred to as powdering) immediately before the process of exposing and baking a film original plate in close contact with the photosensitive layer (printing magazine 53 (10)). 23 (1970) Bengami, Iino, and Printed Information 33 (11), 90 (1973) Kashiyama et al. According to this method, it is possible to roughen the surface of the photosensitive layer (mantle formation) by simply scattering solid powder and form a gap between the film original plate and the photosensitive layer, which can be used as a passage. Since the air in the center can be removed, the vacuum adhesion of the film original plate can be improved. However, the drawback 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. There is the problem of contaminating the surrounding area, and on the other hand, when solid powder is dispersed, it scatters and contaminates the air in the plate-making work room and surrounding equipment, causing various problems in the plate-making process and causing occupational hygiene problems. This also caused various operational problems, such as the fact that it required a lot of time to clean the equipment. As a method that can improve the problem of falling off and scattering of solid powder,
No. 111.102 discloses that a coating layer consisting of a fine pattern including coated portions and non-coated portions is formed on the surface of the photosensitive layer to roughen the surface of the photosensitive layer to improve the vacuum adhesion, A photosensitive printing plate is disclosed in which this coating layer is removed by melting during development. However, with this structure, there is a problem that the coating layer is dissolved in the developer during development, resulting in a decrease in the dissolving power of the developer, so-called fatigue of the developer. In particular, if the developer is tired after being used many times, it will not be completely dissolved and removed, and some of it will remain in the image area, inhibiting the affinity for printing ink when it is later used as a printing plate. However, there is a problem in that it impairs the so-called ink receptivity.

For this reason, there is also a drawback that the tolerance of the developing method is narrow, such as having to adopt a developing method that includes a rubbing step with a brush or the like. Even if a developing method that includes this rubbing step is adopted, if the matting agent remains in the image area, the remaining coating layer must be rubbed off with a brush, making the work complicated. This was reducing work efficiency.

As mentioned above, solid powder is sprinkled on the surface of the photosensitive layer,
Conventional photosensitive printing plates in which coating layers with minute patterns are formed have various problems, and improvements have been desired.

OBJECTS OF THE INVENTION A first object of the present invention is to provide an improved photosensitive printing plate using the vacuum contact method which causes less developer fatigue.

A second object of the present invention is to provide an improved photosensitive printing plate using the vacuum adhesion method, which does not adversely affect the adhesion of ink to the image areas.

A third object of the present invention is to provide a photosensitive printing plate that has a wide range of developing method tolerances.

Structure of the Invention In order to achieve the above object, the present invention provides a photosensitive printing plate having a photosensitive layer on a support and a matting agent fixed to the surface of the photosensitive layer. is characterized by its affinity for printing inks and insolubility in developing solutions.

The matting agent used in the present invention is one that has an affinity for printing ink and is insoluble in a developer.

Affinity for printing ink refers to the property that printing ink is a mixture of vehicle and colorant, so when it comes into contact with these, it does not dissipate these.
If this property exists, the ink receptivity will not be impaired. Examples of materials for such a mantle agent include ethyl cellulose, rosin, rosin esters (for example, methyl abietate and its hydrogenated product, diethylene glycol abietate, monoethylene glycol abietate),
Polyvinyl acetate, polyvinylidene chloride, polyvinyl acetal (e.g. polyvinyl butyral, polyvinyl formal), polyacrylic ester, polymethacrylic ester, polystyrene and its derivatives, polyamide, polyethylene, polypropylene, polyethylene terephthalate, polychloroprene, PVC resin, urea resin, epoxy resin, phenolic resin (e.g. novolac type phenolic resin, resol type phenolic resin, specifically phenol-formaldehyde resin, cresol-formaldehyde resin, resorcinol-benzaldehyde resin, pt-butylphenol formaldehyde resin,
p-t-aminophenol formaldehyde resin, p-
octylphenol formaldehyde resin, p-phenylphenol formaldehyde resin) and various copolymers such as butadiene-acrylonitrile, methacrylic acid-methyl methacrylate, methyl methacrylate-
Butyl methacrylate-acrylic acid, methyl methacrylate-divinyl styrene, ethylene-propylene, ethylene-vinyl acetate, methyl methacrylate-ethyl acrylate-methacrylic acid, methyl methacrylate-ethyl acrylate-acrylic acid, styrene-methyl methacrylate, styrene-butyl methacrylate-acrylic acid, styrene-methacrylic acid-ethyl acrylate-methyl methacrylate. Among these, the proportion of one acid monomer unit is preferably 5 mol % or less. This is because the vehicle of printing ink is usually lipophilic. Polymers of these monomers can be produced by solution polymerization, suspension polymerization,
Those obtained by various polymerization methods such as emulsion polymerization can be used.

Moreover, these polymers can of course be used alone, but 2
N or more combinations may be used. Particles of the cloak agent made of these materials may be solid particles of each material coated with one or more other materials. Further, the solid particles of the mantle agent themselves or the material covering the particles may contain an absorbent having absorbency in the active light region used for exposing the photosensitive printing plate. Examples of such absorbents include tartrazine (C,1,A-c
id Yellow-23), pigments such as titanium yellow, diazo compounds such as p-diazodiphenylamine chloride and zinc chloride double salt, and ultraviolet absorbers such as hydroxybenzophenone.

Further, the matting agent used in the present invention is insoluble in the developer. Here, "insoluble in developer" means that it is not dissolved and removed by the developer during development, and in practical terms, it is preferable that it not be removed even after being immersed in the developer for 3 minutes at 25°C.Developer There are various types of capping agents, so the material for the capping agent exemplified above is selected depending on each type.For example, when the developer is isopropyl alcohol-water (volume ratio 2:1), Examples include polyvinyl formal, polyvinyl acecool such as polyvinyl butyral, polyethyl methacrylate, and Buna N rubber (butadiene 75-acrylonitrile 25 copolymer).When the developer is acetone-water (volume ratio 1:1), is an epoxy resin of bisphenol A and epichlorohydrin, and when the developer is methanol, polystyrene, polyvinyl chloride, neorene or Buna N.
(butadiene 75-acrylonitrile 25 copolymer),
The developer is isopropyl alcohol-water (volume ratio 1:2)
In the case of polyvinyl acetate, the developer is isopropyl alcohol-water (volume ratio 1:10), polyamide resin, and the developer is acetonitrile-water (volume ratio 2:10).
In the case of 1), polyvinyl chloride, when the developer is ethanol-water (volume ratio 1:2), cellulose acetate butyrate (48% butyryl), and when the developer is water saturated with methyl ethyl ketone, , a 55:45 mixture of polyvinyl chloride-Buna N, polychloroprene when the developer is water, and pt- when the developer is an alkaline aqueous solution with a 0.5 normal concentration.
Examples include butylphenol formaldehyde resin, pt-aminophenol formaldehyde resin, p-octylphenol formaldehyde resin, and p-phenylphenol formaldehyde +84 fat.

The above-mentioned developer can be appropriately selected from conventionally known developers depending on the photosensitive material used in the photosensitive printing plate, the binder used if necessary, and the developing method. The insoluble capping agent material is selected as described above from those exemplified above. Specific examples of the materials for these developing solutions include the following.

When using an alkaline developer, the alkaline agents include (A) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium salt or ammonium salt of dibasic or tertiary phosphoric acid, carbonate; Inorganic alkaline agents such as sodium and ammonia, 1 (B) Mono-, di- or trimethylamine, mono-, di- or triethylamine, mono- or di-isopropylamine, n-butylamine, mono-, di- or triethanolamine, mono- , di-, or triisopropanolamine, and organic amine compounds such as ethylenediimine.

Examples of acids when using an acidic developer include hydrochloric acid, phosphoric acid, tartaric acid, citric acid, and acetic acid.

Organic solvents used in developing solutions containing organic solvents include:
For example, ketones such as methyl ethyl ketone and acetone,
Examples include nitriles such as acetonitrile, alcohols such as isopropyl alcohol, benzyl alcohol, diacetone alcohol, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monobutyl ether. Furthermore, a surfactant, a water-soluble sulfite, etc. may be added as necessary. The water-soluble sulfite is preferably an alkaline metal salt, an alkaline earth metal salt, or an ammonium salt of sulfite, such as sodium sulfite, potassium sulfite, lithium sulfite, magnesium sulfite, and the like.

The shape of the solid particles fixed on the surface of the photosensitive layer side and the distribution density of the solid particles on the surface of the photosensitive layer side are such that when the solid particles are fixed on the surface of the photosensitive layer side, a film original plate is attached by the above-mentioned vacuum adhesion method. When the printing plate is used for printing with the matting agent remaining in the image area of the printing plate, it is important to For example, spherical,
Various shapes such as hemispheres, ellipses, semi-ellipses, cylinders, elliptical cylinders, and prismatic shapes, as well as irregular shapes such as those obtained by grinding materials with a ball mill, jet mill, etc., can be used. The size of the solid particles is preferably 2 to 100 μm, particularly preferably 3 to 50 μm in diameter when projected. 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 .mu.m, particularly preferably 2 to 20 .mu.m. In addition, the ratio of all particles of the matting agent to the surface of the photosensitive printing original plate is 0.3 to 12
% is preferred, particularly 0.5 to 10%. Especially from the point of view of the clarity of the printed image, the center line surface roughness Ra is 20μ.
The following is desirable.

Various conventionally known methods can be used for fixing the mantle agent to the surface of the photosensitive layer. This method includes a method of scattering and fixing the solid particles, and a method of scattering or coating a solution or dispersion of the material.

As a method of spraying, for example, J, J Sokol, R, C Hendrinkson, Plastic Engineering Handbook, p, 426P, 4.31 (1976).
(J, J, 5-okol and RoC, Hen
dricks-on Plastic Eng, H
In addition to the fluidized bed electrostatic spray, electrostatic fluidized bed, etc. described in Andbook-K (1976), methods using air 4 spray, brush, puff, etc. can be used as appropriate. The amount of matting agent to be sprayed or applied is 1 on the photosensitive layer side surface.
mn (appropriately 1 to 1000 solid particles per unit,
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. Here, "fixing" refers to the fact that the mantle agent does not easily fall off due to rubbing during normal plate-making operations in the process before the above-mentioned development process, and is particularly preferable on the surface of the photosensitive layer side of the photosensitive printing plate. This means that when foreign matter adheres to the surface, the cloak agent is adhered to such an extent that it will not be removed together with the foreign matter by wiping the surface with a cloth or the like.

A method of thermally melting at least a portion of the particles of the solid powder described in fllJ2 and thermally fusing them to the surface of the photosensitive layer. For example, after scattering powder particles, the photosensitive printing original plate is heated to melt and fix the portions of the powder particles that are in contact with the photosensitive layer. Alternatively, during the above-mentioned dispersion, the powder particles are passed through a hot atmosphere to heat-melt the surfaces of the powder particles, and the melt is fixed to the surface of the photosensitive layer.

(2) A method in which at least a portion of the powder particles are dissolved in a solvent and fixed to the surface of the photosensitive layer. For example, in the process of manufacturing a photosensitive printing original plate, when a photosensitive resin liquid, which will be described later, is applied onto a support and dried, there is still sufficient solvent remaining in this photosensitive layer (especially preferred during lapse rate drying). The remaining solvent dissolves some of the powder particles and fixes them on the photosensitive layer. Details of the methods (1) and (2) above and other details related thereto are described in, for example, Japanese Patent Application Laid-Open No. 12974/1983.

Although the above example was in the form of a powder, it can also be used in a melted or dispersed state as follows.

(3) A method in which an aqueous solution in which powder particles of a cape agent are dissolved or dispersed is sprinkled, and then dried and fixed.

There are the following methods for applying the i'8 solution or the dispersed liquid.

(4) A method in which a solution in which a matting agent material is dissolved or dispersed is contained and held in the recess of a roll having a partially recessed part, and the solution is applied to the surface of the photosensitive layer directly or via another coach roll. . Details of this method and other related details are described in, for example, Japanese Patent Laid-Open No. 51-96604.

In this way, the mantle agent is fixed to the photosensitive layer side of the photosensitive printing original plate having the photosensitive layer described below on the support described later, and the surface on the photosensitive layer side is formed into a mantle. When the photosensitive printing plate made in this way is operated according to the vacuum adhesion method described above, during the process of removing air, the mantle agent is interposed between the film original plate and the photosensitive layer side, and the central portion is formed between the two. A passage for air to escape is secured, and the entire air between the film original plate and the photosensitive layer side can be removed. In this way, the film original plate can be brought into close contact with the photosensitive layer side reliably and quickly. Then, exposure baking is performed, and the baked photosensitive printing plate is immersed in a developer solution, leaving the hardened and undissolved portions of the hardened portions and unhardened portions generated by the irradiation of light on the photosensitive layer, and the unhardened melted portions. When it is removed by melting, the mantle agent fixed to the photosensitive layer side of the melted portion is removed into the developer along with this photosensitive layer side while remaining undissolved.
On the other hand, the mantle agent fixed to the photosensitive layer side of the undissolved portion remains undissolved in the developer. As described above, since the mantle agent does not dissolve in the developer, the dissolving power of the dissolved portion of the developer on the photosensitive layer side is not reduced, and fatigue of the developer can be reduced. In this way, a printing plate is produced in which the unmelted portions are the image areas and the dissolved areas are the non-image areas. When printing is carried out using this printing plate, the matting agent has an affinity for the printing ink, so it blends in with the ink and does not impair the ink receptivity.

The photosensitive printing plate of the present invention further has a resin layer on the photosensitive layer of the photosensitive printing original plate, and includes those in which a capping agent is fixed to this resin layer in the same manner as described above.

The photosensitive printing plate formed as described above can be used as described above in various types of plate making such as lithographic printing, letterpress printing, and intaglio printing.

The photosensitive printing original plate used in the present invention has a photosensitive layer on a support, and the support 8 is a plate-shaped support that is conventionally known. It is selected as appropriate depending on the purpose of use, method of use, abdominal method, etc. of the plate. Examples of the material for this support include paper, plastic (including paper laminated with plastic), and metal (including paper or plastic with metal vapor-deposited and laminated). Examples of the above plastics include polyethylene,
Examples include polyethylene terephthalate, polypropylene, polystyrene, polyvinyl acetal, polycarbonate, nitrocellulose, diacetylcellulose, triacetylcellulose, and the like. Further, examples of the metal include aluminum (including alloys), zinc, copper, iron, and the like. Among these, aluminum is preferable for lithographic printing, and aluminum, zinc, iron,
Polyethylene terephthalate is preferred. The surface of the support may be treated in advance depending on the surface type, and if the surface type is a lithographic type, it is subjected to a hydrophilic treatment. This hydrophilic treatment method can be selected as appropriate depending on the material of the surface of the support. When a metal such as aluminum is used as the support surface, roughening treatment, anodizing treatment,
Preferred methods include immersion in a fluorozirconate aqueous solution, immersion in a silicate aqueous solution, and immersion in a phosphate aqueous solution. These various hydrophilic treatment methods may be combined; an example is a method in which roughening treatment and immersion in a sodium silicate aqueous solution are sequentially performed (US Pat. No. 27M0
No. 66 Akira ♀ ■ Yoi Otsuko), a method of sequentially performing anodizing treatment, and immersion in silicate water fB solution (described in detail in US Pat. No. 3,181,461). - If the material of the force support surface is plastic,
A method known as so-called silver halide photography can be used. Examples include discharge treatment, chemical treatment, laser treatment, and further providing a subbing layer.

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 developing solution upon exposure, and those that cause a difference between molecules before and after exposure. It is possible to use a material that causes a difference in the adhesive strength of the photosensitive layer, or a material that causes a difference in the affinity of the photosensitive layer for water and oil depending on exposure. Typical examples will be explained below.

First, a quinonediazide type positive photosensitive material such as a conventionally known 0-naphthoquinonediazide compound may be mentioned.

The 0-quinonediazide compound is a compound having at least one 0-quinonediazide group, preferably an 0-benzoquinonediazide group or an O-naphthoquinonediazide group, and is a compound having various known structures, such as 1. Written by Koser
L i g h-t-3ensistive Syst
emsJ (J-ohn Wi Iey&5ons
, Tnc, 1965) pages 339-353. Particularly suitable are esters of various hydroxyl compounds and 0-naphthoquinonediazide sulfonic acid. Preferred hydroxyl compounds include resins obtained by condensation of phenols and compounds containing one carbonyl group, particularly resins obtained by condensation in the presence of an acidic catalyst. Examples of the above-mentioned phenols include phenol, resorcinol, cresol, pyrogallol, etc., and examples of the above-mentioned carbonyl group-containing compounds include aldehydes such as formaldehyde and benzaldehyde, and ketones such as acetone.

Especially phenol/formaldehyde resin, cresol/
Formaldehyde resin, pyrogallol acetone resin,
Resorcinol benzaldehyde resin is preferred. Typical specific examples of the 0-quinonediazide compound include benzoquinone-(1,2)-diazide sulfonyl chloride or naphthoquinone-(1,2)-diazide sulfonyl chloride and phenol formaldehyde resin or cresol formaldehyde resin. ester, U.S. Patent No. 3,
Sulfonic acid ester of naphthoquinone-(L2)-diazide sulfonyl chloride and pyrogallol acetone resin described in JP-A No. 635,709, JP-A-5
Naphthoquinone ~(1,2)-diazide-(2)-5 described in Publication No. 6-1044
- Condensate of sulfonyl chloride and resorcinol-benzaldehyde resin, naphthoquinone-(1,2)-diazide-(
2] -5 Ester compound of sulfonyl chloride and resorcinol-pyrogallol-acetone copolycondensate, and other useful compounds. - As a quinonediazide compound, JP-A No. 5
(A product obtained by esterifying a polyester having a hydroxyl group at the end as described in Japanese Patent Publication No. 117503, and a p- Examples include homopolymers of hydroxystyrene or copolymers of hydroxystyrene with other copolymerizable monomers, which are esterified with 0-naphthoquinonediazide sulfonyl chloride.The content of these 0-quinonediazide compounds is determined by exposure to light. 5 to 5 to the total solid content of the sexual composition
It is preferably 80% by weight, particularly preferably 10 to 50% by weight.

3 Such a quinone diazide type positive photosensitive substance can be used in combination with an alkali-soluble resin as a binder, if necessary. As the alkali-soluble resin, those obtained by condensing phenols and ketones or aldehydes in the presence of an acidic catalyst are preferred. Examples of the phenols include phenol, cresol, and p-? ! Examples include converted phenol and the like. Examples of the aldehydes include acetaldehyde and formaldehyde, with formaldehyde being preferred. As a ketone, acetone resin is preferable.

Preferred alkali-soluble resins include, for example, phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate resin described in JP-A-55-57841, and JP-A-55-127553. Copolymerized condensate resins of p-substituted phenol and phenol or cresol and formaldehyde as described in , condensates of benzaldehyde and polyhydric phenols such as resorcinol-benzaldehyde resins and pyrogallol loupe 4 nzaldehyde resins. , a copolycondensate of a polyhydric phenol such as pyrogallol-resorcinol-acetone resin and acetin, and xylenol-formaldehyde resin. 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% market 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. Particular preference is given to salts of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde, such as reaction products of hexafluorophosphates, tetrafluoroborates, perchlorates or periodates with the above condensates. Certain diazo resin inorganic salts and U.S. Patent No. 3.3
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. Various polymer compounds can be used as such a binder, but monomers having an aromatic hydroxyl group such as those described in JP-A-5.4-98613 are preferable, such as N-
(4-hydroxyphenyl)acrylamide, N-(4
-hydroxyphenyl) methacrylamide, o-, m=
or copolymers of p-hydroxystyrene, o −+ m −+ or p-hydroxyphenyl meccrylate, etc. with other monomers, as described in U.S. Pat. No. 4,123,276. Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as a main repeating unit, natural resins such as shellac and rosin, polyvinyl alcohol, and US Pat.
751.257, linear polyurethane resins as described in U.S. Pat. No. 3,660,097, phthalated resins of polyvinyl alcohol, condensed from bisphenol A and epichlorohydrin. Celluloses such as epoxy resins, cellulose acetate, and cellulose acetate phthalate are included.6 Further photosensitive substances include polyesters containing -CH=CH-C- as a photosensitive group in the main chain or side chain of the polymer; Polyamides and polycarbonates containing photosensitive polymers as a main component are also restricted. For example, a photosensitive polyester obtained by condensing phenylene diethyl acrylate with hydrogenated bisphenol A and triethylene glycol, as described in JP-A-55-40415, U.S. Pat. No. 2,956,878. Examples include photosensitive polyesters derived from (2-properidene)malonic acid compounds such as cinnamylidenemalonic acid and difunctional glycols as described in the specification of the present invention.

Furthermore, aromatic azide compounds in which an azide group is bonded to an aromatic ring directly or via a carbonyl group or a sulfonyl group are also used as other photosensitive substances. For example, polyazidostyrene as described in U.S. Pat. No. 3,096,311, polyvinyl-p-azidobenzoate, polyvinyl-p-
-Azidobenzal, a reaction product of azidoarylsulfanyl chloride and an unsaturated hydrocarbon polymer described in Japanese Patent Publication No. 45-9613, and Japanese Patent Publication No. 43-2
No. 1067, No. 44-229, No. 44-22
Examples include polymers having sulfonyl azide or carbonyl azide, as described in Japanese Patent No. 954 and Japanese Patent No. 4.5-24915.

Furthermore, as another photosensitive substance, a photopolymerizable composition comprising an addition polymerizable unsaturated compound is also used.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, since the matting agent is made insoluble in the developer, the matting agent does not dissolve in the developer and reduce its dissolving power, thereby reducing the fatigue of the developer. You can do less. Furthermore, since the mantle agent has an affinity for printing ink, the mantle agent remains fixed to the image area of the printing plate for two days after development so that there is no adverse effect on the ink receptivity. Therefore, the developing method is not limited to a method including a rubbing step, and various methods can be applied. In addition, compared to conventional matting agents that sometimes remain in the image area of the printing plate after development, this developing method does not require extra work such as scrubbing off this residual material with a brush, making it a highly efficient developing method. can be provided.

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

Example 1 An aluminum plate was immersed in a 20% aqueous solution of sodium phosphate to degrease it, roughened by electrolytic etching, anodized in sulfuric acid solution, and then immersed in a sodium silicate solution for sealing. processed.

A water-soluble p-diazophenylamine-formaldehyde resin photosensitive layer was formed on this aluminum support, and a polyvinyl formal resin layer was further formed thereon to obtain a photosensitive lithographic printing original plate.

A methyl ethyl ketone solution of polyethyl methacrylate resin was applied as a capping agent onto the polyvinyl formal resin layer of this photosensitive printing original plate, and dried to obtain a photosensitive lithographic printing plate.

A negative original film was placed on the photosensitive layer side of this photosensitive lithographic printing plate, and the film was adhered to the photosensitive layer using a vacuum adhesion method, and then exposed to light from a distance of 60 cm using a 35 ampere carbon arc lamp as a light source for 2 minutes.

After exposure, isopropyl alcohol-water (volume ratio 2:
1) A lithographic printing plate was obtained by developing using a developer and lightly rubbing with a sponge. In this lithographic printing plate, the polyethyl methacrylate resin layer and the polyvinyl formal resin layer of the capping agent remain in their original state in the exposed area, and in the non-exposed area, as the photosensitive layer dissolves, the layers above the photosensitive layer Both resin layers had been removed. When offset printing was performed using this lithographic printing plate, many prints with clear printed images were obtained.

Example 2 An aluminum plate was degreased by immersing it in a 20% aqueous sodium phosphate solution, roughened to zero by electrolytic etching, anodized in a sulfuric acid solution, and then sealed with hot water. A photosensitive solution having the following composition was applied onto this aluminum plate and dried at 85° C. for 3 minutes to obtain a photosensitive lithographic printing original plate. The coating amount after drying was 2.7 g/bo.

(Photosensitive liquid composition) Esterified product of naphthoquinone-(1,2)-diazide-5-sulfonic acid chloride and m-cresol formaldehyde resin (condensation rate 25 mol%) 3
．． 5 gm-cresol formaldehyde resin 8.
0 g naphthoquinone-(1,2)-diazide-4-sulfonic acid chloride 0.15 gp-octylphenol formaldehyde resin and naphthoquinone-(
Esterified product with 1,2)-diazido-5-sulfonic acid chloride (condensation rate 50 mol%) 0.1
2 g Oil Blue #603 (Orient Chemical Industry Co., Ltd.) 0.2 g Ethylene glycol monoethyl ether 100 g 1 A mantle agent was ground on the surface of the photosensitive layer of the photosensitive lithographic printing original plate obtained in this way using a ball mill. Powder particles of polystyrene (average molecular weight: 150,000, particle size: 2 to 10μ), which were classified using a classifier (Zigzag classifier manufactured by Alpime), were dispersed using a spray gun, and then exposed to an air bath at 150°C for 5 seconds to solidify. A photosensitive lithographic printing plate was obtained. A positive original was adhered to the photosensitive layer side of the photosensitive lithographic printing plate thus obtained using a vacuum adhesion method, and a 2Kw metal halide lamp (idle fin 200 manufactured by Iwasaki Electric Co., Ltd.) was used.
0) as a light source, the plate was exposed for 80 seconds from a distance of 1 m, then immersed in a 4% by weight aqueous sodium silicate solution and developed at 25°C for 50 seconds to obtain a lithographic printing plate. The mantle agent was also adhered to the image area of this printing plate as it was. When this printing plate was then printed on an offset printing machine, many printed matter with clear images were obtained. Similar good results were also obtained when development was performed using a so-called fatigue developer in which 10 photosensitive lithographic printing plates were developed in advance.

On the other hand, a photosensitive lithographic printing plate was obtained in the same manner as above except that hydroxypropyl methylcellulose (degree of hydroxypropylation: 9 mol%, degree of methoxylation: 30%) was used in place of the above polystyrene as a capping agent. Exposure and development were performed in the same manner. As a result, especially when a fatigued developer was used, hydroxypropyl methylcellulose remained in the image area, and the ink receptivity of the printing ink deteriorated, making it impossible to obtain good printed matter.

Example 3 In place of p-diazodiphenylamine-formaldehyde resin of the material of the photosensitive layer of Example 1, l1l-)luenesulfonate of p-diazodiphenylamine-formaldehyde resin was used, and polyvinyl chloride was used in place of polyvinyl formal resin. A photosensitive lithographic printing plate was also obtained in the same manner as in Example 1, except that a toluene solution of polystyrene was used instead of the methyl ethyl ketone solution of polyethyl methacrylate resin as the capping agent.

After exposing a negative original in close contact in the same manner as in Example 1,
When developed using methanol, the matting agent was fixed to the image area of the printing plate in its original state as in Example 3 Zetsuta 1, but good lithographic printing yielded the same printing results as Example 1. A version was obtained.

Example 4 Exposure was carried out in the same manner as in Example 1, except that a Buna-N rubber layer was used instead of the polyvinyl formal resin layer of Example 1, and a methanol solution of polyvinyl butyral resin was used instead of the methyl ethyl ketone solution of polyethyl methacrylate resin. A lithographic printing plate was obtained and exposed in the same manner as in Example 1,
When a development process was performed, good results similar to those in Example 1 were obtained.

Example 5 A toluene solution of ethyl cellulose (ethoxyl group content: 49%) was applied as a capping agent to the surface of the photosensitive layer of a photosensitive lithographic printing original plate obtained in the same manner as in Example 2 using a roll having partially concave portions. The coating was coated and dried to obtain a photosensitive planographic printing plate. When exposed and developed in the same manner as in Example 2, the matting agent did not dissolve in the developer. In addition, the printed images of a large number of printed materials printed using the 4th lithographic printing plate were clear.

Example 6 The same procedure as in Example 2 was carried out except that a chloroform solution of polyvinyl butyral was used instead of the toluene solution of ethyl cellulose in Example 5, and the same good results as in Example 2 were obtained.

Example 7 A photosensitive solution having the following composition was applied to the same support as used in Example 1, and dried at 85° C. for 3 minutes to obtain a photosensitive lithographic printing original plate. The coating amount after drying was 2.0 g/n.

(Photosensitive liquid composition) Copolymer A 5.0 g Diazo resin B O.5 g Jurimer AC-10L 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 monomethyl Ether 100 m15 (coating solvent) However, the above copolymer A is obtained by dissolving the composition of p-hydroxyphenylmethacrylamide/acrylonitrile/ethyl acrylate/methacrylic M-10/30/60/6 in molar ratio in methyl cellosolve, 6 in a nitrogen-substituted sealed tube
The mixture was heated at 5° 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 is a 5% by weight diazo resin at room temperature, trade name, E, H, C Co., Ltd.! li! ID-012)
The aqueous solution and 10% by weight ammonium hexafluorophosphate aqueous solution were mixed, and the resulting precipitate was absorbed and filtered.
It is a hexafluorophosphate obtained by drying under reduced pressure at °C.

The TIJM average molecular weight of the copolymer was 80,000, and when the molecular weight distribution of the diazo resin was measured by gel permeation chromatography (GPC), trimers and below accounted for 95 mol% of the total.

Styrene-butyl methacrylate (5:3:2 molar ratio) (particles), which was crushed with a ball mill and classified with the above classifier, was applied as a capping agent to the surface of the photosensitive layer of the photosensitive lithographic printing original plate thus obtained. Diameter 10-15
, cr) particles were dispersed with a spray gun and fixed by exposing them to an air bath at 130° C. for 5 seconds.

A negative original film was closely attached to the photosensitive surface of the photosensitive lithographic printing plate obtained in this manner, and exposure was performed for 42 seconds from a distance of 1 m using the 2Kw metal halide lamp as a light source, and a developer having the following composition was used for 25 seconds. C. for 45 seconds to obtain a lithographic printing plate.

(Developer composition) Ethyl glycol phenyl ether 160 g Jetanolamine 70 g Pionin A-44B 50 g (Takemoto Yushi Co., Ltd.) Water 78
When this printing plate was then printed on an offset printing machine, many prints with clear images were obtained. Similarly good results were also obtained when a tired developer was used.

Example Day 7 A photosensitive lithographic printing plate was obtained in exactly the same manner as in Example 7 except that the polystyrene particles used in Example 2 were used as the solid particles for scattering, and then developed and printed. Similar results were obtained.

Example 9 Photosensitization was carried out in the same manner as in Example 7, except that N-p-hydroxyphenyl methacrylamide/N-p-benzoyloxyphenyl methacrylamide (6:4 molar ratio) particles were used as the powder particles of the mantle agent to be sprayed. A lithographic printing plate was obtained, and when it was developed and printed, the same good results as in Example 7 were obtained.

Example 10 The particles used in Example 7 were used as powder particles for scattering.

Other than that, a photosensitive lithographic printing plate was obtained in the same manner as in Example 2, and the same results as in Example 2 were obtained by performing development and printing.

8

Claims (1)

[Claims] (1) In a photosensitive printing plate that has a photosensitive layer on a support and a matting agent fixed to the surface of this photosensitive layer, the matting agent has an affinity for printing ink and can be developed. A photosensitive printing plate characterized by being insoluble in liquid.