JPH05100432A - Dampening waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To obtain the planographic printing plate which is short in the time required for vacuum contact with an original picture film at the time of image exposing, obviates the dislodgment of silica particles in spite of the friction of the surface of a cover film with the rear surface of another plate and rubbing with the surface of another plate at the time of production transportation and handling and is, therefore, not changed in vacuum contact time by plate making conditions. CONSTITUTION:This dampening waterless photosensitive planographic printing plate is constituted by laminating a photosensitive resin layer, an ink repulsion layer and a cover film having raggedness on the surface on a base. The raggedness of the above-mentioned cover film is formed by applying a film formable resin soln. contg. the silica particles and a crosslinking agent on the cover film, then drying the coating to crosslink and cure the coating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fountain solution-free photosensitive lithographic printing plate, and in particular, a fountain solution-free photosensitive lithographic printing plate excellent in vacuum adhesion to an original image (lith film) during exposure. Regarding the edition.

[0002]

2. Description of the Related Art A photosensitive lithographic printing plate having an ink-repellent layer such as silicone rubber or fluororesin as an upper layer, which does not require fountain solution, has a very smooth surface and good adhesion, Since it will be firmly fixed when it comes into close contact with the film, it is very difficult to remove the bubbles left between the original image and the plate surface when the original image film is stacked on this surface at the time of exposure for vacuum adhesion. When exposure is performed with insufficient adhesion, there is a problem that blurring occurs and the original image cannot be faithfully reproduced. In order to solve this problem, Japanese Patent Publication No. 61-614 proposes a method in which a cover film having irregularities on the surface is laminated on the ink repellent layer to improve the vacuum adhesion.

Further, Japanese Patent Application Laid-Open No. 2-63051 discloses that a cover film having particles having an average particle diameter of 4 to 9 μm and a refractive index of 1.4 to 1.7 is provided.

[0004]

The method described in Japanese Patent Laid-Open No. 2-63051 described above can improve the vacuum adhesion, but the conventional photosensitive lithographic printing plate (PS) using fountain solution is used.
Version) is still insufficient compared to. In particular, during the production of a photosensitive lithographic printing plate that does not require fountain solution, when the cover film is continuously laminated and wound on a roll-shaped lithographic printing plate, or continuously cut and stacked, or during transportation. In addition, there is a problem that silica particles on the surface of the cover film fall off during handling of the plate for plate making, resulting in a decrease in vacuum adhesion.

Accordingly, an object of the present invention is to provide a photosensitive lithographic printing plate which does not require a fountain solution and has excellent vacuum adhesion to an original film during exposure, that is, a short time required for vacuum adhesion and excellent productivity. That is.

[0006]

The present inventor has arrived at the present invention described below as a result of extensive studies to solve such a problem. That is, the present invention is a photosensitive lithographic printing plate requiring no fountain solution, which comprises a photosensitive resin layer, an ink repellent layer, and a cover film having unevenness on the surface, and the unevenness of the cover film is silica. A photosensitive lithographic printing plate not requiring fountain solution, which is obtained by applying a film-forming resin solution containing particles and a cross-linking agent onto a cover film, drying and cross-linking curing.

The film-forming resin used in the present invention is a polymer soluble in a suitable solvent, and preferably has two or more crosslinker-reactive groups at the terminal and / or side chains of the molecule. It is a thing. Examples of such resin include polyester resin, polyurethane resin, epoxy resin, acrylic resin, polyamide resin, polyvinyl alcohol resin, butyral resin, cellulose acetate, alkyd resin,
Examples thereof include polyvinyl chloride, polyvinylidene chloride, chlorinated polypropylene and polystyrene. Among these resins, polyester resin having OH group, terminal OH
Particularly preferred are those having a functional group that is directly reactive with the crosslinking agent, such as a polyurethane resin having a group or an amino group, an epoxy resin, an acrylic resin having an OH group, an amino group or a carboxyl group in its side chain, or polyvinyl alcohol.

As the crosslinking agent used in the present invention, a polyfunctional isocyanate crosslinking agent, a polyfunctional epoxy crosslinking agent, an amino resin crosslinking agent and the like are used. The crosslinking agent is appropriately selected in consideration of compatibility with the polymer binder used, reactivity, solubility in the solvent used, and the like. The polyfunctional isocyanate cross-linking agent is appropriately selected depending on the compatibility with the coating film forming binder, the solubility in the coating solvent, and the like, but diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), naphthalene diisocyanate, tolidine diisocyanate, hexa Methylene diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, lysine diisocyanate, undecane triisocyanate, hexamethylene diisocyanate, bicycloheptane triisocyanate, urethane prepolymer having an isocyanate group at the end, for example, Coronate (manufactured by Nippon Polyurethane Co., Ltd.) , Takenate (manufactured by Takeda Pharmaceutical Company Limited)
Is used.

As a more preferred embodiment of using an isocyanate cross-linking agent, there is a method in which a film-forming resin contains a group having an active hydrogen such as a hydroxyl group, an amino group or a carboxyl group and is directly reacted and cured with the cross-linking agent. Curing with an epoxy compound is usually carried out with a monomer containing two or more reactive epoxy groups in the molecule, a prepolymer, a compound having active hydrogen such as an amino group reactive with these epoxy groups, and a catalyst compound if necessary. Examples of the epoxy compound include diglycidyl ether of bisphenol A, epoxyphenol novolac, epoxycresol novolac, polyethylene glycol diglycidyl ether, glycerol triglycidyl ether, sorbitol polyglycidyl ether, triglycidyl isocyanurate, adipic acid diglycidyl ester, and the like. There is. Further, the products marketed include Epicoat series compounds (Yukaka Shell Epoxy Co., Ltd.), Adeka Resin series (Asahi Denka Co., Ltd.), and Rikaresin series (Shin Nippon Rika Co., Ltd.). As the compound used as the epoxy curing agent, any compound can be used as long as it has two or more groups having active hydrogen such as amino group, hydroxyl group and carboxyl group, but amine compound is preferably used because of its rapid curability. To be done. Many such amine compounds are commercially available as Epicure (Yukaka Shell Epoxy Co., Ltd.) and ADEKA HARDNER (Asahi Denka Co., Ltd.) in accordance with the above-mentioned product series of epoxy compounds. As a more preferred embodiment, a method in which a polymer binder that forms a resin layer contains a group having active hydrogen and is cured, as in the case of using a polyfunctional isocyanate crosslinking agent, can be mentioned.

Other cross-linking methods include cross-linking using amino resins such as melamine resins, benzoguanamine resins and urea resins. In the cross-linking using amino resin,
As the film-forming resin, alkyd resin, acrylic resin and epoxy resin are preferably used. As the silica particles used in the present invention, those having an average particle diameter of 1 to 30 μm measured by a Coulter counter method are used, and if the particle size is in this range, it may be formed by pulverizing natural silica, It may be synthesized by a wet method or the like. Further, a type in which the surface of silica is modified with an organic substance is preferable from the viewpoint of excellent dispersibility in a coating film forming resin. If the particle size is smaller than 1 μm, the effect of improving the vacuum adhesion becomes insufficient, and if it is larger than 30 μm, sedimentation of silica particles occurs during or after coating after the preparation of the solution and a predetermined amount of silica is produced. The particles are not coated on the cover film and thus the vacuum adhesion is insufficient. From the above points, the preferable particle size of the silica particles is 2 to 20 μm, and more preferably 3 to 15 μm. The amount of the particles added is 0.1 mg / m ^{2 to} 100
It is preferably mg / m ² , more preferably 1.0 mg
/ M ^{2 to} 50 mg / m ² . The ratio of the silica particles to the polymer binder forming the resin layer is 0.1 wt% to
It is 20 wt%, preferably 0.5 wt% to 10 wt%.

It is essential that the cover film of the present invention is transparent to light for exposing the photosensitive lithographic printing plate not requiring fountain solution. Examples of such a film include known transparent plastic films such as polyethylene terephthalate, polypropylene, polyvinylidene chloride, polyvinyl chloride, polyamide, polyurethane and polystyrene. In order to improve the adhesion between these films and the resin layer containing silica provided thereon, it is preferable to activate the surface of the cover film in advance by corona discharge treatment or flame treatment. The thickness of the film is 2 to 20 μm, preferably 4 to 15 μm
Is appropriate.

Further, if necessary, a dye may be added to the resin layer for the purpose of facilitating detection of complete removal of the cover film during development processing and reducing fogging due to safety light. good. Further, an antistatic agent such as an ionic surfactant may be added in order to prevent electrification when the cover film is peeled off. The fountain solution-free lithographic printing plate of the present invention is described below.

The lithographic printing plate requiring no fountain solution of the present invention must have flexibility so that it can be set in an ordinary printing machine and at the same time withstand the load applied during printing. Therefore, as a typical substrate, a coated paper, a metal plate such as aluminum, a plastic film such as polyethylene terephthalate, rubber or a combination thereof can be mentioned. The surface of these substrates may be further coated with a primer layer or the like for the purpose of preventing halation and other purposes.

As the primer layer, various types can be used for the purpose of improving the adhesion between the substrate and the photosensitive resin layer, preventing halation, dyeing an image and improving printing characteristics. For example, various photosensitive polymers as disclosed in JP-A-60-229031 are exposed and cured before laminating a photosensitive resin layer, and disclosed in JP-A-62-50760. Heat-cured epoxy resin,
The gelatin film disclosed in JP-A-63-133151, which is hardened, and further disclosed in JP-A-3-200965 and Japanese Patent Application No. 2-200965.
Examples thereof include those using the urethane resin disclosed in the specification of 79572. In addition, a casein-hardened casein is also effective. Further, for the purpose of softening the primer layer, polyurethane, polyamide, styrene / butadiene rubber, carboxy-modified styrene / butadiene rubber, acrylonitrile / butadiene rubber, carboxy-modified acrylonitrile having a glass transition temperature of room temperature or lower is contained in the primer layer. Polymers such as / butadiene rubber, polyisoprene, acrylate rubber, polyethylene, chlorinated polyethylene and chlorinated polypropylene may be added. The addition ratio is arbitrary, and the primer layer may be formed only with the additive as long as it is within the range in which the film layer can be formed. In addition, in accordance with the above-mentioned purpose, these primer layers have a dye, a pH indicator, a printout agent, a photopolymerization initiator, an adhesive (for example, a polymerizable monomer, a diazo resin, a silane coupling agent, a titanate coupling agent). And aluminum coupling agent), pigments, and additives such as silica powder can be included. Generally, the coating amount of the primer layer is appropriately in the range of 0.1 to 20 g / m ² as dry weight, preferably 1 to 10 g / m ² .

The photosensitive layer used in the present invention is generally any as long as it causes a difference in solubility in a developing solution upon exposure or a change in adhesiveness at the interface with the upper ink repellent layer. Even one can be used. The image formation may be negative or positive. The compound or composition constituting such a photosensitive layer includes the following.

(A) Photopolymerizable photosensitive resin layer (i) Monomer or oligomer having olefinically unsaturated double bond group, (ii) High molecular compound having film-forming ability, which is used as necessary (iii) A photopolymerizable composition comprising a photopolymerization initiator.

In the photosensitive resin composition containing the above-mentioned components (i) to (iii), the polymer compound in which the components (i) and (ii) are bonded, that is, the side chain is photopolymerizable or photocrosslinkable. A photosensitive resin composition containing a polymer compound having an olefinically unsaturated double bond group and having a film-forming ability is also suitable for use in the present invention. Further, a photosensitive resin composition in which the monomer or oligomer of the component (i) is further added to the compound in which the components (i) and (ii) are bound is more preferable.

Specific examples of such a photosensitive composition include JP-B No. 54-26923, JP-A No. 1-214839, and JP-A No. 1-237663.
No. 2, JP-A-2-236550, JP-A 3-155553, JP-A 3-16
1753 and Japanese Patent Application No. 3-19768 can be cited. (B) Photodimerization-type photosensitive composition In the main chain or side chain of a polymer, cinnamic acid and its ester,
A photosensitive composition comprising an amide, a polymer having a substituted maleimide group and a chalcone group in a side chain, and the like. Specific examples of such a photosensitive composition include JP-A-49-7005,
JP-A 1-235955, JP-A 1-235956 and JP-A 1-2376
The items shown in Japanese Patent No. 64 can be cited.

(C) A composition comprising a photocurable diazo resin or azide resin, a photosensitizer if necessary, and some filler additives. Examples of the photocurable diazo resin include zinc chloride double salt of a condensation product of a diazo amine such as paradiazodiphenylamine, paradiazomonoethylaniline, and paradiazobenzylethylaniline with formaldehyde, and hexafluorophosphate. ..

This photosensitive resin composition is essentially different from the photosensitive resin composition mentioned in (A) in that it does not contain a compound having a photopolymerizable unsaturated double bond group. Examples of the photo-curable azide resin include azidophthalic acid ester of polyvinyl alcohol, azidobenzoic acid ester, styrene-maleic anhydride copolymer and aromatic azide alcohol such as β- (4-azidophenol) ethanol ester. Is mentioned.

(D) Composition consisting of o-quinonediazide compound Particularly preferred o-quinonediazide compound is o-naphthoquinonediazide compound, for example, US Pat. No. 2,766,1
No. 18, No. 2,767,092, No. 2,772,972, No. 2,8
59,112, 2,907,665, 3,046,110, and
3,046,111, 3,046,115, 3,046,118,
No. 3,046,119, No. 3,046,120, No. 3,046,121
No. 3,046,122, No. 3,046,123, No. 3,06
No. 1,430, No. 3,102,809, No. 3,106,465, No. 3
Starting with the specifications of 3,635,709 and 3,647,443,
It is described in many publications and can be used preferably. Among these, particularly esters of aromatic hydroxy compounds ο-naphthoquinonediazide sulfonic acid, polyethylene glycol and naphthoquinone-1,2-diazide-4-sulfonic acid or naphthoquinone-1,2-diazide-5-sulfonic acid ester , Polymeric amines and amides of naphthoquinone-1,2-diazide-4-sulfonic acid or naphthoquinone-1,2-diazide-5-sulfonic acid, polymethacrylic acid p-hydroxyanilide and naphthoquinone-
1,2-diazide-4-sulfonic acid or naphthoquinone-
1,2-diazido-5-sulfonic acid ester, amine-modified natural resin rosin, and naphthoquinone-1,2
An amide of diazide-5-sulfonic acid, an epoxy resin from bisphenol A and propylene oxide and an ester of naphthoquinone-1,2-diazide-5-sulfonic acid,
Polymers of (meth) acrylic acid and dihydroxyphenyl monoester and naphthoquinone-1,2-diazide-4
-Sulfonic acid or naphthoquinone-1,2-diazide-5
-Sulfonic acid ester, polymer of condensation product of aminoisophthalic acid diallyl ester and naphthoquinone diazide sulfonic acid, polycarbonate of quinone diazide sulfonic acid ester of carbonate or quinone diazide crosslinked with isocyanate, etc., bisphenol A and naphthoquinone-1 , 2diazide-4-sulfonic acid or naphthoquinone-
1,2-diazide-5-sulfonic acid ester, naphthoquinone-1,2-diazido-5-sulfonic acid with phenol, phenols such as p-cresol, alcohols such as ethyl, propyl, butyl and amyl alcohol Examples thereof include esters and amides of naphthoquinone-1,2-diazide-5-sulfonic acid with amines such as aniline and p-hydroxyaniline.

The photosensitive composition as described above can be further prepared by, if necessary, US Pat. Nos. 3,787,351, 4,487,823, and US Pat.
In addition to containing a surfactant as described in 4,822,713, etc., for example, 2-methoxyethanol, 2-methoxyethyl acetate, methyl lactate, ethyl lactate, propylene glycol monomethyl ether, methanol,
A suitable solvent such as ethanol, methyl ethyl ketone, or water is dissolved alone or in a mixed solvent in which these are appropriately combined, and the solution is applied onto the support. The coating amount is suitably in the range of about 0.1 to 20 g / m ² by dry weight, and preferably 0.5 to 10 g / m ² .

As the ink repellent layer used in the present invention, a silicone rubber layer is mainly used, but a fluorine-containing resin layer can also be used as shown in JP-A-2-32355. As the preferred silicone rubber of the present invention, linear or crosslinked polyorganosiloxane is preferred.

The polyorganosiloxane has a molecular weight of usually 1,000 to several hundreds of thousands, and is appropriately crosslinked in the form of a liquid, a wax or a dough at room temperature. The polyorganosiloxane is classified into a condensation type and an addition type depending on the method of crosslinking. In the condensation type, crosslinking is performed by a condensation reaction, and water, alcohol, organic acid, etc. are released by the reaction. As a particularly useful condensation type silicone rubber, a mixture of a linear polyorganosiloxane having a hydroxyl group, an acetoxy group or the like at both ends or a part of the main chain and a silicone crosslinking agent, or a compound obtained by reacting the hydroxyl group with a silicone crosslinking agent And the addition of a condensation catalyst is advantageous in terms of crosslinking speed.

The main chain of the polyorganosiloxane has the following repeating units. —Si (R ¹ ) (R ² ) —O— In the formula, R ¹ and R ² are each an alkyl group which may have a substituent, an aryl group, an alkenyl group or a combination thereof, a methyl group, a phenyl group. A group, a vinyl group and a trifluoropropyl group are preferable, and a methyl group is particularly preferable.

As the above silicone crosslinking agent, --OCO
^{_{CH 3, -O-NR 3 R}} 4, -O-N = CR 3 R 4, -
OR, -NR ³ R ⁴ or -OH (wherein, R ³ and R ^4,
Is a condensing type silicone cross-linking agent having a functional group represented by () is a so-called deacetic acid type, deoxime type, dealcohol type, deamino type, dehydration type and the like. Examples of such a cross-linking agent include tetraacetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, phenyltriacetoxysilane, dimethyldiacetoxysilane, diethyldiacetoxysilane,
Vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, methyltris (acetoneoxime) silane, methyltri (N-methyl, N-acetylamino) silane, vinyltri (methylethylketoxime) silane, methyltri (methylethylketoxime) ) Silane or its oligomer can be mentioned.

The amount of each of these crosslinking agents is preferably 0.5 to 30 parts by weight based on 100 parts by weight of polyorganosiloxane. Examples of the condensation catalyst include organic carboxylic acids, titanic acid esters, acetylacetone metal complexes, chloroplatinic acid, naphthenic acid and the like. The addition type means an unsaturated group in the main body, for example, a vinyl group (-CH = CH
₂ ) refers to the one in which the hydrogen group in the cross-linking agent is added to cross-link.

Specific examples include vinyl group-containing organopolysiloxane, hydrogenated organopolysiloxane and the like mixed with a platinum catalyst (eg chloroplatinic acid). The polyorganosiloxane has a repeating unit similar to the condensation type in the main chain. In the silicone rubber layer of the present invention, it is possible to use either or both of condensation type and addition type silicone rubbers.

It is also possible to use a condensation and addition type one having a hydroxyl group and an unsaturated group in one polyorganosiloxane.

[0030]

The time required for vacuum contact with the original film during image exposure is short, and the surface of the cover film rubs against the back surface of another plate or rubs against the surface of the plate making table during manufacturing, transportation and plate handling. Even if this is done, the silica particles do not fall off, and therefore the vacuum contact time does not change depending on the plate making conditions. (Examples) Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0031]

Example-1 (Primer layer) 0.3 mm thick JI degreased by a conventional method
The S A 1050 aluminum plate was dipped in a 1% aqueous solution of KBM603 (manufactured by Shin-Etsu Chemical Co., Ltd.), which is an aminosilane coupling agent, and then dried at room temperature. The following primer layer was applied onto the aluminum plate so that the dry weight was 4 g / m ^2, and the film was dried and hardened by heating at 140 ° C. for 2 minutes.

Sampren IB1700D (manufactured by Sanyo Kasei Co., Ltd.) 10 parts by weight Takenate D110N (manufactured by Takeda Chemical Industries, Ltd.) 0.5 parts by weight TiO ₂ 0.1 parts by weight Defender MCF323 (Dainippon Ink and Chemicals Co., Ltd. 0.1. 03 parts by weight Propylene glycol methyl ether acetate 50 parts by weight Methyl lactate 20 parts by weight (photosensitive layer) On an aluminum plate coated with the primer layer,
A photopolymerizable photosensitive solution having the following composition was applied so as to have a dry weight of 5 g / m ^2, and dried at 100 ° C. for 1 minute.

Samprene IB1700D (manufactured by Sanyo Kasei Co., Ltd.) 5.0 parts by weight A-1000 (manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.5 parts by weight Addition product of 1 mol of xylylenediamine / 1 mol of glycidyl methacrylate 1. 0 parts by weight Ethyl Michler's ketone 0.35 parts by weight 2,4-diethylthioxanthone 0.10 parts by weight Victoria Plublue BOH naphthalene sulfonate 0.01 parts by weight Defender MCF323 (Dainippon Ink and Chemicals Co., Ltd. 0.03 parts by weight) Part manufactured by Methyl ethyl ketone 10 parts by weight propylene glycol methyl ether 25 parts by weight (ink repellent layer) The following silicone rubber composition liquid was applied on the photopolymerizable dry layer to a dry weight of 2 g / m ² . It was dried at 140 ° C. for 2 minutes.

Α, ω-divinylpolydimethylsiloxane (polymerization degree: about 700) 9 parts by weight (CH ₃ ) ₃ -Si-O- (Si (CH ₃ ) _2- O) _30- (SiH (CH ₃ ) -O ) _10- Si (CH ₃ ) ₃ 1.2 parts by weight Polydimethylsiloxane (polymerization degree of about 8,000) 0.5 parts by weight Olefin-chloroplatinic acid 0.2 parts by weight Inhibitor 0.3 parts by weight Isopar G ( 140 parts by weight of Esso Chemical Co., Ltd. A dampening water-free photosensitive lithographic printing plate precursor was prepared as described above.

2 with a thickness of 9 μm that has been subjected to corona discharge treatment
A resin solution having the following composition was applied onto an axially oriented polypropylene film (OPP film) with a gravure coater at a coating speed of 50 m / min, passed through a drying zone of 70 ° C. for 10 seconds to dry, and after winding, 40 2 in ℃ storage
Store for 4 hours, fully cure the crosslinking agent, 1.0g
A cover film provided with a substantially uniform resin layer of / m ² was prepared.

Byron 200 (polyester resin manufactured by Toyobo Co., Ltd.) 30 parts by weight Mizukasil P-78F (silica particles manufactured by Mizusawa Chemical Industry Co., Ltd.) 2.0 parts by weight Coronate HL (Nippon Polyurethane Industry Co., Ltd. non-yellowing) 2.0 parts by weight Isocyanate-based cross-linking agent) Toluene 33 parts by weight Methyl ethyl ketone 33 parts by weight The surface of the cover film on which the resin layer is not applied is the silicone rubber layer of the photosensitive lithographic printing plate precursor which does not require the fountain solution. The layers were laminated so as to be in contact with each other to obtain a photosensitive lithographic printing plate of Example 1 which did not require fountain solution.

This plate was cut into 670 mm × 560 mm, and 6
A film original having a positive image of 00 mm × 500 mm was brought into close contact, and a contact exposure of 70 counts was performed using a horizontal vacuum printing machine TYPE P-802G manufactured by Dainippon Screen Mfg. Co., Ltd. At this time, the time required for vacuum adhesion is 16
It was for a second. Next, after the entire surface of the cover film of this plate was wiped with a cloth, vacuum adhesion was performed again by the same method as above. As a result, the time required for vacuum adhesion is 16
There was no change in seconds.

After peeling off the cover film of the plate after exposure, the plate was immersed in a 20% aqueous solution of diethylene glycol at 40 ° C. for 1 minute and then rubbed with a developing pad in water to remove the silicone rubber layer in the unexposed area. did. Subsequently, when dyeing with a dyeing solution having the following composition and evaluating the image quality, a good image without blur was reproduced. (Staining solution) Crystal violet 0.1 part by weight Diethylene glycol 15 parts by weight Pure water 85 parts by weight

[0039]

[Comparative Example-1] A resin solution having the following composition was applied onto the OPP film used in Example-1 in the same manner as in Example-1 using a gravure coater and dried to obtain a cover film of Comparative Example-1. Created. Byron 200 (Toyobo Co., Ltd. polyester resin) 30 parts by weight Mizukasil P-78F (Mizusawa Chemical Co., Ltd. silica particles) 2.0 parts by weight Toluene 34 parts by weight Methyl ethyl ketone 34 parts by weight The cover film of Comparative Example-1 was prepared. By laminating on the surface of the silicone rubber layer of the dampening water unnecessary photosensitive lithographic printing plate prepared in Example-1, a dampening water unnecessary photosensitive lithographic printing plate of Comparative Example-1 was obtained.

The sample of Comparative Example-1 was cut into the same size as the sample of Example-1, and contact exposure was carried out in the same manner as in Example-1. At this time, the time required for vacuum adhesion was 19 seconds. Next, after the entire surface of the cover film of this plate was wiped with a cloth, vacuum adhesion was performed again by the same method as above. As a result, the time required for vacuum adhesion was 25 seconds, which was significantly longer than that before the cloth was wiped with a cloth. When the surface of the cover film after being wiped with a cloth was magnified 100 times and observed with a microscope, many crater-like holes in which silica particles had fallen were formed.

[0041]

Example-2 A polyethylene terephthalate film (PET film) having a thickness of 6 μm and subjected to corona discharge treatment was coated with a resin solution having the following composition at a coating speed of 30 m / min using a gravure coater, and then at 70 ° C. After passing through the drying zone for 16 seconds to dry and wind,
The cover film of Example-2 provided with a substantially uniform resin layer of 0.7 g / m ² was prepared by storing in a storage cabinet at 24 ° C for 24 hours and sufficiently curing the crosslinking agent.

Crisbon 4010 (HV) (Dainippon Ink and Chemicals, Inc., thermosetting 60 parts by weight Polyurethane resin: 50% solution) Mizukasil P-78E (silica particles, manufactured by Mizusawa Chemical Co., Ltd.) 2.0 parts by weight Crisbon NX (Dainippon Ink and Chemicals, Inc., 6.0 parts by weight polyisocyanate nate cross-linking agent) toluene 19.2 parts by weight methyl ethyl ketone 12.8 parts by weight The cover film of Example-2 was dampened as prepared in Example-1. A waterless photosensitive lithographic printing plate was laminated on the surface of the silicone rubber layer of the waterless photosensitive lithographic printing plate to obtain a dampening water-free photosensitive lithographic printing plate of Example-2.

The sample of Example-2 was cut into the same size as the sample of Example-1, and contact exposure was carried out by the same method as in Example-1. At this time, the time required for vacuum adhesion was 17 seconds. This printing plate was subjected to a developing treatment in the same manner as in Example-1, and the image quality was evaluated. As a result, a good image without blur was reproduced.

Next, after the entire surface of the cover film of this plate was wiped with a cloth, vacuum adhesion was performed again by the same method as above. As a result, the time required for vacuum adhesion was 17 seconds, and there was no change.

[0045]

Example-3 A biaxially stretched polypropylene film (OPP film) having a thickness of 9 μm and subjected to corona discharge treatment was coated with a resin solution having the following composition by a gravure coater at a coating speed of 50 m / min, and then at 70 ° C. After passing through the drying zone for 10 seconds to dry, and after winding, store in a storage at 40 ° C for 48 hours to sufficiently cure the cross-linking agent to 1.0.
A cover film provided with a substantially uniform resin layer of g / m ² was prepared.

Byron 200 (polyester resin manufactured by Toyobo Co., Ltd.) 30 parts by weight Mizukasil P-78F (silica particles manufactured by Mizusawa Chemical Industry Co., Ltd.) 2.0 parts by weight Epicoat 807 (epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.) 2.0 parts by weight Crosslinking agent Epoxy equivalent 170) Toluene 33 parts by weight Methylethylketone 33 parts by weight The cover film of Example-3 was applied to the surface of the silicone rubber layer of the fountain solution-free photosensitive lithographic printing plate prepared in Example-1. Lamination was carried out to obtain a photosensitive lithographic printing plate of Example-3 which did not require fountain solution.

The sample of Example-3 was cut into the same size as the sample of Example-1, and contact exposure was carried out by the same method as in Example-1. At this time, the time required for vacuum adhesion was 16 seconds. This printing plate was subjected to a developing treatment in the same manner as in Example-1, and the image quality was evaluated. As a result, a good image without blur was reproduced.

Next, after the entire surface of the cover film of this plate was wiped with a cloth, vacuum adhesion was performed again by the same method as above. As a result, the time required for vacuum adhesion was 16 seconds, and there was no change.

[Procedure amendment]

[Submission date] October 30, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

Samprene IB1700D (manufactured by Sanyo Kasei Co., Ltd.) 5.0 parts by weight A-1000 (manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.5 parts by weight Adduct of 1 mol of xylylenediamine / 1 mol of glycidyl methacrylate 1 0.0 parts by weight Ethyl Michler's ketone 0.35 parts by weight 2,4-diethylthioxanthone 0.10 parts by weight Victoria Puble-BOH naphthalene sulfonate 0.01 parts by weight Defender MCF323 (Dainippon Ink and Chemicals Inc. 0 0.0 3 parts by weight Methyl ethyl ketone 10 parts by weight Propylene glycol methyl ether 25 parts by weight (ink repellent layer) The following silicone rubber composition liquid is dried on the photopolymerizable photosensitive layer to a dry weight of 2 g / m ² . And then dried at 140 ° C. for 2 minutes.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

After peeling off the cover film of the exposed plate, diethylene glycol monoethyl ether 20
After immersing the plate in a 40% aqueous solution of 40% for 1 minute,
The unexposed portion of the silicone rubber layer was removed by rubbing with a developing pad in water. Subsequently, when dyeing with a dyeing solution having the following composition and evaluating the image quality, a good image without blur was reproduced. (Staining solution) Chris violet 0.1 part by weight Diethylene glycol monoethyl ether 15 parts by weight Pure water 85 parts by weight

Claims (1)

[Claims] 1. A photosensitive lithographic printing plate that does not require fountain solution, which comprises a photosensitive resin layer, an ink repellent layer, and a cover film having irregularities on the surface of a support, and the irregularities on the surface of the cover film are silica. A photosensitive lithographic printing plate not requiring a fountain solution, which is obtained by applying a film-forming resin solution containing particles and a cross-linking agent onto a cover film, drying, and cross-linking and curing.