JPS61217296A - Planographic plate blank - Google Patents

Abstract

PURPOSE:To enhance application properties in providing a surface layer, provides high-quality printed images and contrive higher sensitivity and higher durability in printing, by a method wherein a photoconductive layer comprising a photoconductive substance and a crosslinked phenoxy resin as main constituents and a surface layer are sequentially laminated on a conductive base. CONSTITUTION:The photoconductive layer 2 comprising a photoconductive substance and a crosslinked phenoxy resin as a main constituents and the surface layer comprising as a main constiuent a reaction product of a crosslinking agent with a resin having an annular acid anhydride structure are sequentially laminated on the conductive base 1. The crosslinking agent used in the layers 2, 3 is preferably a polyisocyanate compound. The reaction product, per se, is hydrophobic and has sufficient resistance for holding an electrostatic latent image, but when it is treated with an alkeline liquid, the surface thereof becomes hydrophilic. In this case, the surface becomes hydrophilic but not water-soluble and has sufficient water resistance, so that high durability in printing can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a lithographic printing original plate that is subjected to JR printing using an electrophotographic method. The present invention relates to a lithographic printing original plate provided with a layer that changes in shape.

Prior art lithographic printing original plates include those provided with various photosensitive resin layers on a substrate (or conductive substrate), those provided with a silver halide photosensitive material, or those provided with a layer of photoconductive material. Those equipped with this are used.

Among these, printing original plates made by electrophotography using photoconductivity are widely used in the field of light printing because they can be easily made directly from originals (direct plate making).

This printing original plate has a photoconductive layer of a zinc oxide-resin dispersion system on a conductive support, and after forming a toner image by electrophotography, it is treated with an aqueous solution containing, for example, ferrocyanate. , the surface of the non-image area was made hydrophilic to make a printing plate, but since the strength of the photoconductive layer was not sufficient,
There was a problem in that the printing durability was only about 0 to 10,000 sheets.

On the other hand, the special public service No. 37-17162, the special public service No. 38-7758
, JP 4.6-39405, JP 52-2437,
JP-A-56-107246, JP-A-55-10525
4, JP-A-55-153948, JP-A-56-161
25, JP-A-57-147656, JP-A-56-14
6145, JP-A-57-161863, etc., for example, a layer consisting of an organic photoconductive compound and an alkali-soluble resin on a water-retaining conductive support such as a grained aluminum plate, or A layer in which a charge-generating pigment such as a phthalocyanine pigment is dispersed in an alkali-soluble resin, or a layer sensitized by adding an electron-attracting substance or an electron-donating substance to this dispersed layer is used for photoengraving. The original printed version is shown. This loincloth original printing plate is made by forming a toner image entirely on the photosensitive layer using an electrophotographic method, and then eluting and removing the photosensitive layer in the non-image area with an alkaline solution.It is a direct plate making printing plate with high printing durability. However, as a photoreceptor for electrophotography, it has low sensitivity and requires a high-output light source, and also has the disadvantage that the elution process takes time and plate making is slow. Was.

In addition, a method for producing a complete printing original plate of the non-image area surface treatment type, which facilitates plate making by providing a fixed resin layer (surface layer) on a magnetic photoreceptor, is disclosed in Japanese Publication No. 45-5606. is shown. This surface layer is composed of a vinyl ether-maleic anhydride copolymer and a hydrophobic resin compatible with this. When treated with an alkali after toner image formation, the acid anhydride ring portion in the non-image area becomes hydrophilic due to hydrolysis and ring opening. A printing plate is obtained. However, the vinyl ether-maleic anhydride copolymer used here becomes water-soluble when the acid anhydride ring opens and becomes hydrophilic, so high printing durability cannot be obtained. Ta.

The present inventor previously discovered a hydrophilizable surface layer (hereinafter referred to as "hydrophilic layer") consisting of a reaction product of a resin having a cyclic acid anhydride structure and a crosslinking agent on an electrophotographic photosensitive layer (photoconductive layer). We have proposed all original printing plates with a This surface layer can be easily made hydrophilic, but unlike the above-mentioned surface layer made of vinyl ether-maleic anhydride copolymer and hydrophobic resin, it remains water resistant even after being made hydrophilic because it is crosslinked.
It also had high mechanical strength and long printing durability.

However, when forming the entire surface layer on the photoconductive layer (electrophotographic photosensitive layer), depending on the type of binder resin used for the photoconductive layer and the aX type of solvent used in the surface layer coating solution (1. Foaming occurs in the coating film. In some cases, such defects may occur.

Purpose The purpose of this development is to improve the coatability of the surface layer in printing plates having a hydrophilic surface layer on the photoconductive layer, thereby achieving even higher quality printed images in the entire thickness. The object of the present invention is to provide a lithographic printing original plate having high sensitivity and high printing durability.

Structure The printing original plate of the present invention has a photoconductive layer mainly composed of a phenoxy resin crosslinked with a photoconductive substance and a crosslinking agent on a conductive support, and a reaction product of a resin having a cyclic acid anhydride structure and a crosslinking agent. It is a lithographic printing original plate in which surface layers are sequentially laminated as main components.

As the crosslinking agent used in the photoconductive layer in this printing original plate, it is preferable to use a polyisocyanate compound, and
The surface layer is preferably one whose main component is a reaction product of a resin having an anhydride structure and a crosslinking agent. Typical examples of the resin having a cyclic anhydride structure used in the surface layer include copolymers containing maleic anhydride as a single copolymerization component, and polyincyanate compounds as the crosslinking agent.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The lithographic printing original plate of the present invention will be described in more detail below with reference to the accompanying drawings. FIG. 1 is a sectional view showing the structure of a basic lithographic printing original plate according to the present invention, in which 1 is a conductive support, 2 is a photoconductive layer, and 3 is a surface layer that can be made hydrophilic (
(R hydratable layer).

In the image forming process in electrophotography, an electrostatic latent image is first formed by positive or negative charging and a subsequent image.

At this time, the surface layer 4 that holds the electrolytic latent iron needs to be highly resistive and hydrophobic to the extent that the charge does not diffuse in the surface direction (if it is water-residual, the resistance will be low due to moisture absorption). , electrostatic #image cannot be retained). The electrostatic latent image is then developed and fixed with toner charged to the opposite polarity to the surface charge to form a toner image on the surface layer 4. The printing is
Since this is done based on the difference between the lipophilicity (inkphilicity) of the toner image and the hydrophilicity of the non-image area, the surface of the front surface 1 trout 3 needs to be hydrophilic during printing.

In this way, the surface layer 4 is hydrophobic during electrostatic image formation.
The ability to change to hydrophilic properties during printing is highly sought after.

The reaction product of the resin having a cyclic acid anhydride structure and the crosslinking agent used for the surface layer 3 (hydrophilizable layer) in the present invention is originally hydrophobic and has a sufficient amount of water to maintain the static M/a image. Although it has resistance, the surface becomes hydrophilic when treated with alkaline liquid. Moreover, although it is hydrophilic, it is not water-soluble and has sufficient water resistance, so that high printing durability can be obtained.

The photo-j4 conductive layer 2 is formed of a photoconductive material and a layered resin. Examples of the light-conducting substance include inorganic photoconductive substances such as high-Z zinc oxide, titanium vanide, selenium, selenium alloys, cadmium oxide, cadmium selenide, and silicon, or, for example, the following (1) to There are organic photoconductive materials as shown in (15).

(1) Triphenylmethane pigments such as malachite green and crystal violet, methylene blue,
Thiazine dyes such as methylene green, anthracene dyes such as Astrazone Orange R1, Astrazone Yellow 3GL, and Anthracene Red 6B, cyanine dyes such as Eisen Astrafuroxin FF, xanthine dyes such as Rhodamine B, 2,6-diphenyl-4 -(N,N
- dimethylaminophenyl) thiapyrylium verchlorate, cationic dyes such as biryllium dyes such as benzopyrylium salts.

(2) Perylene pigments such as perylene anhydride and perylene imide.

(3) Indigo pigment.

(4) Quinacridone pigment.

(5) Polycyclic quinones such as anthraquinones, pyrenequinones, anthoanthros, and flavanthrones.

(6) Bisbenzimidazole pigment.

(7) Square methine pigment.

(8) Indathlon pigment.

(9) Phthalocyanine pigments such as metal phthalocyanines such as copper phthalocyanine and metal-free phthalocyanine.

(10) A charge transfer complex consisting of an electron-donating substance such as poly-N-vinylcarbazole and an electron-accepting substance such as 2,4,7-trinitrofluorenone.

(11) A eutectic complex formed from a biryllium base dye and a polycarbonate resin.

(12) Barbyric acid derivative or thiobarbital acid derivative.

(13) Azo pigments such as monoazo pigments, disazo pigments and trisazo pigments. Examples of monoazo pigments include monoazo pigments with central skeletons such as anthraquinone and N-phenylcarbazole; examples of disazo pigments include:
For example, benzidine pigments such as Diane Blue and Chlor Diane Blue, or N-ethylcarbazole, stilbene, distilbenzene, naphthalene, fluorenone, fluorene, anthraquinone, 2,5-diphenyl-1,3°4-oxadiazole, Disazo pigments having a central skeleton such as dibenzothiophene, dibenzothiophene dioxite, acridone, or phenanthrenequinone are used; examples of trisazo pigments include trisazo pigments having a central skeleton such as triphenylamine or N-phenylcarbazole. .

(14) Poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene,
Polymeric photoconductive compounds such as polyvinylanthracene.

(15) 2,5-bis(4-diethylaminophenyl)
-1,3,4-oxadiazole, 2,5-bis[4-
(4-diethylaminophenylpphenyl)-1,3,
4-Oxadiazole, 2-(9-ethylcarbazolyl-3-)-5-(4-diethylaminophenyl)-1
, oxadiazole compounds such as 3゜4-oxadiazole, 2-vinyl-4-(2-chlorophenyl)-5
Oxazole compounds such as -(4-diethylamino)oxazole, 2-(4-diethylaminophenyl)-4-phenyloxazole, 1-phenyl-3-(4-diethylaminostyryl)-5-(4-diethylaminophenyl)pyrazoline, l - Pyrazoline compounds such as -phenyl-3-(4-dimethylaminostyryl)-5-(4-dimethylaminophenyl)pyrazoline, 2,2'
-dimethyl-4,4'-bis(diethylamino)triphenylmethane, 1. Diphenylmethane compounds such as l-bis(4-dibenzylaminophenyl)propane, tris(4-diethylaminophenyl)methane, 9-(4-
dimethylaminobenzylidene) fluorene, 3-(9-
Fluorene compounds such as fluorenonedene)-9-ethylcarbazole, styryl anthracene compounds such as 9-(,i-diethylaminostyryl) anthracene, 9-bromo-10-(4-diethylaminostyryl) anthracene, 1,2-bis(4 - to distyrylbenzene compounds such as diethylaminostyryl)benzene, 1,2-bis(2,4-dimethoxysteryl)benzene, 9-ethylcarbazole-3-aldehyde 1-methyl-1-phenylhydrazone, 9-ethylcarbazole- 3-Aldehyde 1-benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde, 1,1-diphenylhydrazone, 2,4-dimethoxybenzaldehyde 1-benzyl-1-phenylhydrazone, 4-diphenylaminobenzaldehyde l-methyl-1- Hydrazone compounds such as phenylhydrazone, stilbene compounds such as 4-diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolyl aminostilbene, 1-(4
-diphenylaminostyryl)naphthalene, 1-(4-
Styrylnaphthalene compounds such as dibenzylaminostyryl) naphthalene, 4'-diphenylamino-α-phenylstilbene, 4'-methylphenylamino-α-phenylstilbene and other alpha-phenylstilbene compounds, 3-styryl-9-ethylcarpa sol, 3-(4-
styrylcarbazole compounds such as (diethylamino)styryl-9-ethylcarbazole, chloranil, bromoanil, tetracyanoethylene, tetracyanoquinone dimethane, 2,4°7-dolinitro-9-fluorenone% 2,4*5.7-tetranitro- 9-fluoreno/, 2, 4. , 5, 7-ketranitroxanthone, 2.4.8-trinidrothioxanthone, 2°6.8
-) Compounds such as dinitro-4H-inteno[1°2-b]thiophen-4-one, 1.3.7-trinitrodibenzothiophene-5.5-dioxide.

A phenoxy resin crosslinked with a crosslinking agent is used as the binding resin of the photoconductive layer (electrophotographic photosensitive layer).

Phenoxy resins are generally obtained by condensation polymerization of bisphenol A and epichlorohydrin, and are represented by the following structural formula. For example, phenoxy resins manufactured by Union Carbide (PKHC, PKHH, PK
HJ) and other resins that are easily available.

Phenoxy resin can be crosslinked using hydroxyl groups in the resin. As the crosslinking agent, it is preferable to use a polyisocyanate compound.Specific examples include toluene-2.4-diisocyanate, toluene-2.
2,6-diisocyanate, diphenylmethane-4,4
'-diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethylpiphenyl-4,4'-
Diisocyanate, triphenylmethane-4,4',
Aromatic polyisocyanates such as 4'-triisocyanate, l-lis(p-isocyanate phenyl) thiophosphite, polymethylene polyphenyl isocyanate, xylylene diisocyanate, or hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, inholon These include fatty polyisocyanates such as diisocyanates, or two- and three-body types thereof.

Phenoxy resin improves solvent resistance by crosslinking with a polyisocyanate compound.

Therefore, by using this as a binding agent for the entire photoconductive layer, a photoconductor layer having high bath agent resistance can be obtained.

Is there a cyclic acid anhydride structure on the photoconductive layer? 1- Apply a bath liquid in which the resin is dissolved in an organic solvent to form a surface layer. At this time, if the solvent resistance of the photoconductive layer is insufficient for the organic solvent used, foaming may occur. This may cause paint film defects such as However, when a phenoxy resin crosslinked with a polyisocyanate compound is used, since it has high solvent resistance, foaming does not occur and a good coating film can be obtained.

The photoconductive layer 2 may be formed of a single layer as shown in FIG. 1, or may be formed of a multilayer of two or more layers as shown in FIG. In the case of a single layer, (b) a layer in which an inorganic photoconductive substance such as al-zinc oxide or cadmium sulfide or an organic pigment such as a phthalocyanine pigment or an azo pigment is completely dispersed; A layer containing all the compounds as shown or a polymer compound as shown in (14),
(c1 A compound as shown in (15) above, or (
Possible examples include a layer formed by dissolving a polymer compound as shown in 14) and a dye as shown in (1), and (d) a layer formed using a charge transfer complex as shown in (lO) above.

In the case of a multilayer structure, for example, a charge generation layer containing the above-mentioned inorganic photoconductor negative or organic pigment such as phthalocyanine pigment or azo pigment, and a polymer compound as shown in above (14) or (15) may be used. ) may have a structure in which a charge transport layer containing a compound (charge transport substance) gold is laminated as shown in (a).

In this case, the configuration of the printing original plate is as shown in FIG. 2, in which 2' represents a light guide layer, 4 a charge generation layer, and 5 a charge transport layer.

When the photoconductive layer is formed of multiple layers as described above, at least the layer in contact with the surface 1-, for example, in the structure shown in FIG. Uses crosslinked phenoxy resin.

The ratio of photoconductive substance contained in the photoconductive layer is 10 to 95
It is t% by weight, preferably 30 to 90% by weight. If the proportion of the phototetraelectric substance is less than 10i+i%, the J resistance as an electrophotographic photoreceptor decreases, and if it is more than 95% by weight, the mechanical strength of the film is so poor that it cannot be put to practical use.

As mentioned above, the resin having a cyclic acid anhydride structure used in the surface layer 3 (hydrophilizable layer) is a copolymer (hereinafter referred to as maleic anhydride copolymer and maleic anhydride copolymer) containing one maleic anhydride copolymer. ) are preferred, but more specifically, for example, methyl vinyl ether, ethyl vinyl ether, 2-P chlorovinylethyl ether, zologyl vinyl ether, inbutyl vinyl ether, 2-P chlorovinylethyl ether,
These include copolymers of lower alkyl vinyl ethers such as methoxyethyl vinyl ether and maleic anhydride, copolymers of styrene and maleic anhydride, copolymers of ethylene and maleic anhydride, and copolymers of vinyl acetate and maleic anhydride. . In addition, these maleic anhydride copolymers in which a part of the ring-opened anhydride has been opened can also be used.

Further, the surface layer 3 (hydrophilicizable layer) is preferably crosslinked using a crosslinking agent in order to improve the water resistance and strength after hydrophilization. As the crosslinking agent, it is preferable to use a polyisocyanate compound similar to the crosslinking agent for the phenoxy resin in the photoconductive layer.

The conductive support 1 may be, for example, a conductive surface such as an aluminum evaporated film (f-M plastic film, water-resistant and storm-treated paper, an aluminum plate, a copper plate, a temporary zinc plate, a stainless steel plate, etc.). metal plates are used.

To produce the lithographic printing original plate of the present invention, first, a coating solution containing a photosensitive eIJ material, a phenoxy resin, and a crosslinking agent is coated on a 4* support by a conventional method, and a photoconductive layer ( electrophotographic photosensitive layer) is formed. Examples of common agents used in this case include bath agents that do not react with the crosslinking agent, such as tetrahydrofuran, dioxane, N,N-dimethylformamide, acetone, and methyl ethergtone. After applying this coating liquid, drying and heat treatment for crosslinking the phenoxy resin and the crosslinking agent are performed. The temperature and time of this heat treatment will vary depending on the quality of the crosslinking agent, the degree of addition, etc., but can be selected from approximately 80 to 150° C. to several hours. In order to promote this crosslinking reaction, metal compounds such as dibutyltin dilaurate, dibutyltin diacetate, 2-ethylhexane, or amines such as triethylamine may be added as appropriate.

Next, a solution of a resin having a cyclic acid anhydride structure and a crosslinking agent dissolved in a suitable organic solvent such as tetrahydrofuran or dioxane is applied onto the photoconductive layer and dried.
Heat treatment causes a crosslinking reaction to form a surface layer. The temperature and time of the heat treatment here vary depending on the resin and crosslinking agent used, but can be selected within the range of approximately 80 to 200°C and several minutes to several hours. Further, in order to fully promote this crosslinking reaction, the same catalyst as in the photoconductive layer may be added in its entirety.

The surface layer 3 is mainly composed of a reaction product of a resin having a cyclic acid anhydride structure and a crosslinking agent, but in order to improve the strength of the layer, other resins such as polyester resin, polyamide resin, polycarbonate resin, aphrylic resin, etc. T fat, polystyrene resin, vinyl acecool resin, vinyl acetate resin, etc. can be added. However, in this case, the proportion of these resins contained in the entire layer is preferably 50% or less. If it exceeds this range, the rate of hydrophilization in the hydrophilic treatment of the surface of the non-image area performed after image formation will be slow and the hydrophilicity will be insufficient, resulting in background stains on printed matter.

Moreover, the thickness of the surface layer 3 is 0.05 to 5 μm, preferably 0.1 to 2 μm. Above this range, sensitivity decreases in the electrophotographic process, residual positions increase,
If it is below this range, it will cause background staining and the printing durability will decrease.

The plate making of the original printing plate for electrophotographic platemaking of the present invention is performed by first uniformly charging it in a dark place using a corona charger or the like, using a tungsten lamp, halogen lamp, etc., according to the usual electrophotographic method.
Reflection using a light source such as a xenon lamp or fluorescent lamp
An electrostatic latent image is formed by single-image exposure, contact image exposure through a transparent positive film, or scanning exposure with laser light such as a Ha-No laser, argon laser, or semiconductor laser, and this =21- electrostatic latent image is It is developed with toner and heated to form a toner image on the electrophotographic photosensitive layer (FIG. 3).

Next, when the printing plate on which the toner image has been formed is immersed in a totally alkaline hydrophilic treatment liquid, the surface of the non-image area not masked by the toner image is made hydrophilic, and a good printing plate is obtained. (Figure 4) The hydrophilic treatment liquid used here is, for example, an alkaline aqueous solution of inorganic salts such as sodium silicate, sodium phosphate, sodium hydroxide, and sodium carbonate, or an alkaline water bath solution containing organic amines such as triethanolamine and ethylenediamine. Alternatively, a solution prepared by adding an organic solvent such as ethanol, benzyl alcohol, ethylene glycol, or glycerin or a surfactant to these may be used.

The time required for hydrophilization varies depending on the formulation of the surface layer (hydrophilizable layer) 3 and the concentration of the hydrophilic treatment liquid, but it can be carried out in about 0.5 to 2 minutes by selecting appropriate conditions. After the hydrophilic treatment, the lithographic printing plate is changed as necessary, including water resistance and drying.

The hydrophilicity of the non-IiIII surface blood can be determined by the use of water. That is, the contact angle of the surface of the surface layer (!31 hydratable layer) 4 before the hydrophilic treatment is 60 to 80°.

After hydrophilic treatment, the angle decreases to approximately 10-15°, resulting in a surface that is easily soaked in water.

Since the printing original plate of the present invention is intended to make only the non-image area hydrophilic, it is preferable that the toner component used for development contains a resin component having resistivity to the water treatment sediment.

This resin component may be anything that is insoluble in the eluent, for example, acrylic resin using methacrylic acid, methacrylic ester, vinegar, vinyl resin, vinyl acetate and ethylene or chloride. Copolymers such as vinyl, vinyl acetal such as vinyl resin, vinylidene chloride resin, polyvinyl butyral, copolymers such as styrene and butadiene/methacrylic ester, polyethylene, polypropylene and its chloride, polycarbonate, polyester resin, polyamide These include resins, phenolic resins, xylene resins, alkyd resins, waxes, polyolefins, and waxes.

According to the present invention, a printing original plate having a good surface layer (hydrophilicizable layer) without coating film defects can be obtained, and after the plate-making process is completed, the image area coated with the acid-oil toner is highly hydrophilic. In normal planographic printing, oil-based ink adheres only to the image area, resulting in a high-quality printed matter with no background stains. In addition, the surface layer (hydrophilizable layer) after hydrophilic treatment is a coating that is both hydrophilic and highly water resistant, and has good adhesion to the Hikari 4 layer, so the number of printing plates obtained is tens of thousands or more. High printing durability.

Furthermore, since the printing original plate of the present invention can maintain the entire sensitivity of the photoconductive layer (electrophotographic photosensitive layer) itself, it can obtain higher sensitivity than conventional printing original plates. In addition, since the properties of photoconductivity and changing from hydrophobic to hydrophilic are divided into separate layers, the selection range for the photoconductive layer is expanded, and therefore, for example, materials that are sensitive to long wavelength light can be used. If selected, it becomes possible to write with a He-Ne' laser or a semiconductor laser, which has been difficult in the past.

□ Next, the plain clothes printing original plate of the present invention will be explained in more detail with reference to Examples and Comparative Examples. In addition, in the following Examples and Comparative Examples, "Miyako" all represents M okibe f:.

Example 1 1 part of a disazo pigment having a central fluorenone skeleton represented by the above structural formula (1), 19 parts of tetrahydrofuran, and polyvinyl butyral (Detsuka Butyral #400 (+-1-: manufactured by Tanki Kagaku Kogyo Co., Ltd.) A mixture consisting of 6 parts of a 5% by weight tetrahydrofuran solution was optically ground in a ball mill.Next, this mixture was taken out and slowly stirred to form a tetrahydrofuran.
The parts were processed and diluted. This solution was applied onto a 100 μm thick polyester film (conductive support) on which aluminum had been vapor-deposited, and dried at 80° C. for 5 minutes to give a thickness of about 0.0 μm.
A charge generation layer of 5 μm was formed.

Toluene-2,4-
Diisocyanate) 1. 2. Apply a coating solution containing 6 parts and heat at 80°C for 2 minutes followed by 1'l at 105°C for 5 minutes.
After drying, heat treatment was performed at 150°C for 30 minutes to cause a cross-linking reaction, resulting in a charge transport I! with a thickness of about 15 μm! # Fully formed.

On this photoconductive layer (electrophotographic photosensitive layer) consisting of two layers, a charge generation layer and a charge transport layer, a methyl vinyl ether-maleic anhydride compound (manufactured by Aldrich Chemical Co., Ltd., M total molar ratio 1: 1) 1 part, toluene-2,
A solution consisting of 0.1.1 part of 4-diisocyanate) and 32 parts of tetrahydrofuran was applied, dried at 100°C for 5 minutes, and then treated at 150°C for 30 minutes to cause a crosslinking reaction, resulting in a coating of about 0.3 μm. A surface layer (hydrophilic layer) was formed.

No coating film defects such as foaming were observed in the printing original plate formed as described above.

Further, as a result of a peel test using Cellophane Teiso, no peeling was observed at all, and the contact between Hikari 4yaj- and the surface layer was also good.

Example 2 Instead of the phenoxy resin (PKE If() manufactured by Union Carbide Co., Ltd.) used to form the charge transport layer in Example 1, the same phenoxy resin (PKE (J) f (manufactured by Union Carbide)) was used.
The photoconductive layer (
When a lithographic printing original plate consisting of a charge generating layer, a charge transporting layer) and a surface layer was prepared, no coating film defects such as foaming were observed, and the surface Iij appearance was also good.

Example 3 In place of the phenoxy resin (PKE (EL) manufactured by Union Carbide Co., Ltd.) used to form the charge transport layer in Example IV, the same phenoxy resin (PKHC, manufactured by Union Carbide Co., Ltd.) was used.
The photoconductive layer (charge generation layer When a lithographic printing original plate consisting of a charge transport I-) and a surface layer was prepared, no coating defects such as foaming were observed, and the surface layer had good adhesion.

Example 4 Same as Example 1 except that 1.8 parts of diphenylmethane-4,4'-diisocyanate was used instead of the toluene-2,4-diisocyanate crosslinking agent used in Example 1 to form the charge transport layer. When a lithographic printing original plate was prepared using photoconductive rfjI (charge generation layer, charge transport layer) and surface IJ, no film damage due to foaming was observed, and no surface layer contact was observed. was also good.

Comparative Examples 1 to 4 Formed in the same manner as in Example 1, with charge generation j-upper VC at 7'.
, 74 Hydrazone ratio compound 12 represented by formula (i)
A solution consisting of 12 parts of corn fat and 76 parts of tetrahydrofuran as shown in Table 14c below was applied to the entire surface, and then dried at 80°C for 2 minutes and then at 105°C for 5 minutes + i4 to a thickness of about 12 to 16 μm.
The entire charge transport layer was formed.

A surface layer (41
A hydratable layer) was formed, and the entire lithographic printing original plate was prepared. The condition of the coating on the lithographic printing plate obtained in this way is shown below.
IK - Show.

Table 1 From the results in Table 1, it is clear that coating defects such as foaming occur when the resin in the photoconductive layer (charge transport layer in this case) in contact with the surface layer is a non-crosslinked phenoxy resin or other resin. I understand.

Example 5 The original printing plate prepared in Example 1 was negatively charged by performing a corona discharge of 16 KV for 2 zo seconds using an electrostatic copying paper testing device (manufactured by Kawaguchi Shikki Seisakusho: 5P-428). Leave it in the dark for a second, and then the surface potential Vpo
(Volt) was measured, and then the surface was irradiated with light using a tungsten lamp at an illuminance of 4.5 lux, the time required for the surface potential to reach % of Vpo was determined, and the total half-exposure tE% was calculated. The result is Vp.

=-1260 (volts), E%=1. It was a (looks/second).

This printing original plate was electrically heated to approximately -800 volts, and then image exposure was carried out through a lens system using a halogen lamp to form a clear IS image. After that, it was developed with copier toner and heated. The toner image was completely formed under constant conditions.

Next, in order to completely hydrate the surface of the non-image area, it was immersed for 1 minute in an alkaline aqueous solution consisting of 1 part of PS plate development image source P-4 (manufactured by Fuji Photo Film Co., Ltd.) and 8 parts of water.

When the printing plate thus obtained was printed using a Ricoh offset printing machine Model AP-1310 according to a conventional method, more than 20,000 copies with clear print sound and no background stains were printed.

Example 6 A charge generating layer of a disazo pigment having the structural formula (1) was formed in the same manner as in Example 1 on a polyester film having a thickness of 100 μm on which aluminum had been vapor-deposited, and on top of that a charge generating layer containing the following structural formula (
Coating solution in which 8 m'r of diphenylmethane-4,4'-diisocyanate was added to a solution consisting of 12 parts of the compound represented by D, 12 parts of phenoxy resin (manufactured by Union Carbide: PKt(H), and 76 parts of tetrahydrofuran) was applied, dried at 80° C. for 2 minutes, then dried at 105° C. for 5 minutes, and then heat-treated at 150° C. for 30 minutes to cause a crosslinking reaction, thereby forming a charge transport layer with a thickness of about 15 μm.

This photoconductive layer consists of two layers: a charge generation layer and a charge transport layer (
Electrophotographic photosensitive layer) is coated with a layer having a thickness of about 0 in the same manner as in Example 1.
．． A surface layer (hydrophilicizable layer) of 3 μm was formed. The obtained printing original plate had a good coating film with no defects.

Vp was applied to this printing original plate in the same manner as in Example 5.

and E 3A k was measured, Vpo = −1
22' 0 (volts)%E%-1,3 (lux seconds)
Met.

Further, a toner image was entirely formed on this printing original plate in the same manner as in Example 5, and then it was immersed in the same hydrophilic treatment liquid vC for 1 minute to make the surface of the non-image area hydrophilic, and the obtained printing plate was shade-printed on a printing machine. However, I was able to print over 550,000 yen of clear prints with no background stains.

Example 7 A mixture consisting of 1 part of a disazo pigment having the entire central skeleton of distyrylbenzene represented by the above structural formula α■, 0.33 parts of polyester resin (manufactured by Toyobo Co., Ltd.: Vylon 200), and 60 parts of tetrahydrofuran is sufficient in a T-ball mill. Shattered. This dispersion was applied onto a gold-aluminum vaporized polyester film and dried at 80° C. for 5 minutes to form a charge-generating layer with a thickness of about 0.5 μm. On this charge generation layer, a charge transport layer with a thickness of about 15 μm (f) and a surface layer (hydrophilicizable layer) with a thickness of about 0.3 μm were formed in the same manner as in Example 1.
was formed and used as a printing original plate. About this original printing plate Vpo
and E 3'i It measurement, Vpo = -
1150 (volts), E34=1.9 (lux seconds)
Met.

Next, a toner image was formed on this printing original plate in the same manner as in Example 5, and the printing plate obtained by immersing it in the same hydrophilic treatment liquid for 1 minute to make the surface of the non-image area hydrophilic was placed in a printing machine. When printed, more than 20,000 clear prints with no background stains were obtained.

Example 8 Trisazo pigment 1 '65 containing triphenylamine as the center/capital group coated with the above structural formula (■), polyvinyl butyral resin (manufactured by Tunkei Kagaku Co., Ltd.: Nankabutyral $)
4000-1) A mixture consisting of 0.33 parts of cyclohexanone and 12 parts of cyclohexanone was pulverized to the original size using a ball mill, and then 31 parts of cyclohexanone was added to this liquid while stirring, and spread on a cloth. This solution was coated on an aluminum vaporized polyester film and dried at IZO° C. for 5 minutes to form a charge generation layer with a thickness of about 0.5 μm.

On this charge generation 1-, a thickness of about 1
A 5 μm charge transport layer and a 0.3 μm thick surface layer (hydrophilizable layer) were formed to prepare a printing original plate. Regarding this original printing plate, Vpo = -890 (pol)), E% = O, S (
It was Lux Sho).

Next, a toner image was formed on this printing original plate in the same manner as in Example 5, and then it was immersed in the same hydrophilic treatment liquid for 1 minute to make the surface of the non-image area hydrophilic.The obtained printing plate was then printed on a printing machine. As a result, more than 20,000 clear prints with no background stains were obtained.

Effects As described above, according to the present invention, it is possible to obtain a lithographic printing original plate in which no coating film defects such as foaming are observed, which has high sensitivity and high printing durability, and which does not cause background stains.

[Brief explanation of drawings]

FIGS. 1 and 2 are enlarged cross-sectional views of typical planographic printing plates according to the present invention. 3 and 4 are diagrams illustrating the plate-making process fc of the lithographic printing original plate of the present invention, in which FIG. 3 shows the plate after toner image formation, and FIG. 4 shows the plate after hydrophilic treatment. 1... Conductive support 2.2'... Photoconductive layer (electrophotographic photosensitive layer) 3... Surface layer (hydrophilicizable layer) 4... Charge generation layer 5... Charge transport layer 6... Tonneau image 7... Hydrophilic part of surface layer - 37 = 1 rectangle, 2 complete figures

Claims (1)

[Claims] 1. A photoconductive layer mainly composed of a phenoxy resin crosslinked with a photoconductive substance and a crosslinking agent on a conductive support, and a surface layer mainly composed of a reaction product of a resin having a cyclic acid anhydride structure and a crosslinking agent. An original plate for lithographic printing characterized by sequentially laminating layers.