JPS61121060A - Printing plate material for electrophotomechanical process - Google Patents

Abstract

PURPOSE:To form a material high in sensitivity for forming a printing plate high in printing resistance by forming an electrophotographic sensitive layer composed of both of an electrostatic charge generating layer contg. a specified azo pigment and a charge transfer layer on a conductive substrate. CONSTITUTION:The charge generating layer 3 and the charge transfer layer 4 are laminated on the conductive substrate 1 to form the electrophotographic sensitive layers 2. The layer 3 contains the coupler of the azo pigment, such as phenol derivs., preferably, one of formulae 2-7, and it is mainly composed of the azo pigment represented by formula I, preferably, in an amt. of >=30wt%, and the layer 3 is formed, preferably, in a thickness of 0.05-2mum. The layer 4 is composed essentially of a charge transfer material, preferably, in an amt. of 20-60wt%, and an alkali-soluble resin.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a novel printing plate that can be made by electrophotography. More specifically, with a new printing plate containing a specific azo pigment, an electrostatic latent image obtained by charging and subsequent imagewise exposure is developed with toner and fixed to obtain toner vapor. The present invention relates to a printing plate that is made by eluting and removing a photosensitive layer in a non-image area.

BACKGROUND ART Conventionally, as planographic printing original plates, those using photosensitive resins or silver halide photosensitive materials have been known.

However, although lithographic printing plates made of photosensitive resin have high printing durability, they have low sensitivity and cannot be used in so-called direct plate making, requiring the process of first creating negatives or positives from originals using silver halide film. However, there are drawbacks such as the need for large-scale equipment and the time required for plate making.

Dyne 21 printing plates can be produced using diffusion transfer development or curing development of silver halide photosensitive materials, but they have the drawbacks of low printing durability, high cost per sheet, and high cost per sheet. Examples of printing plates for direct plate making using the photographic method include Tokuko Sho 47-47610 and Tokko Sho 4g-40.
002, Special Publication No. 48-18325, Special Publication No. 51-157
No. 66, Japanese Patent Publication No. 51-25761 discloses a zinc oxide-resin dispersion printing plate. After a toner image is formed on this printing plate by electrophotography, it is treated with an acidic aqueous solution containing, for example, a phenic acid salt in order to make the non-image area hydrophilic.

Printing plates made in this way often peel off due to the mechanical pressure applied during printing and the penetration of dampening water into the photosensitive layer and conductive treatment layer, destroying the hydrophilic layer on the surface. The printing durability was about s, ooo to 10,000 sheets.

In addition, zinc oxide/resin dispersion printing plates are dye sensitized in order to have sensitivity in the visible light region, but even so, they do not exhibit sensitivity sufficient for practical use in the long wavelength light region of 600 nm or more. Low output and inexpensive H・-N・
The disadvantage is that exposure cannot be performed using radar or semiconductor radar.

On the other hand, the special public service No. 37-17162, the special public service No. 38-7758
, JP 46-39405, JP 52-2437, JP 56-107246, JP 55-105254,
JP-A-55-153948, JP-A-56-16125
, JP-A-57-147656, JP-A-56-14614
5. JP-A-57-161863 discloses, for example, a layer consisting of an organic photoconductive compound and an alkali-soluble resin on a hydrophilic 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,
Alternatively, a printing original plate for electrophotolithography is disclosed in which a shield or the like is sensitized by adding an electron-withdrawing substance or an electron-donating substance to the dispersion layer. This type of printing plate is made by forming a toner image on a photosensitive layer using an electrophotographic method, and then eluting and removing the photosensitive layer in the non-image area with an alkaline solution. Although it has the advantage that a printing plate can be obtained, it has low sensitivity as a photoreceptor for electrophotography, resulting in a slow plate-making speed and the disadvantage that a high-output light source must be used.

Purpose An object of the present invention is to solve the problems of the conventionally known printing original plates for electrophotographic engraving as described above, and to provide a printing original plate having particularly high sensitivity and high printing durability.

Structure The printing original plate for electrophotolithography of the present invention comprises a charge generation layer containing an azo pigment represented by the following general formula (I) and a charge transport layer containing a charge transport substance and an alkali-soluble resin on a conductive support. It is characterized by being provided with an electrophotographic photosensitive layer consisting of two layers.

General formula (I) (However, A represents a coupler residue.) The basic structure of the printing original plate for electrophotographic engraving of the present invention is shown in FIG.
Here, 1 is a conductive support and 4 is laminated thereon to form an electrophotographic photosensitive layer 2.

The charge generation layer 3 and the charge transport layer 4 can also be stacked upside down.

The power of the azo pigment used in the charge generation layer 3, f blur, is:
For example, compounds with a phenolic hydroxyl group such as phenols and naphthols, aromatic amino compounds with an amino group, aminonaphthols with an amino group and a phenolic hydroxyl group, or aliphatic or aromatic enolic ketone groups (active methylene group). ) is used,
Preferably, the Gler residue A is selected from the group represented by the following general formula:

[Wherein, R4 is hydrogen, an alkyl group, a phenyl group or a substituent thereof, X is a hydrocarbon ring or a substituent thereof, a heterocycle or a 1m substitution thereof, Yf'i hydrocarbon ring M or a tk substituent thereof A heterocyclic group or a substituent thereof, or a styryl group or a substituent thereof, R3 represents hydrogen, an alkyl group, a phenyl group, or a substituent thereof, or R2 and R5 represent the carbon to which they are bonded. A ring may be formed together with the atoms. )] (Formula (2) and R4 in the equation represent a substituted or unsubstituted hydrocarbon group.) T1 (In the formula, R5 represents an alkyl group, a carbamoyl noodle, a carboxyl group, or an ester thereof, and Ar, represents a hydrocarbon ring it or a substituted product thereof.) R, O (wherein, R6 is a hydrocarbon group or a substituted product thereof, Ar
2 represents a hydrocarbon ring group or a substituent thereof0) The hydrocarbon ring for X in the general formula used in the present invention includes, for example, a benzene ring and a naphthalene ring; and the heterocycle includes, for example, an indolphin ring. Ring, carnonazole ring, benzolane 3! The hydrocarbon mi in Y or R2, such as l, is a phenyl group,
Examples of polycyclic groups such as naphthyl group, anthryl group, and pyrenyl group include pyridyl group, chenyl group, furyl group, inodryl group, be/Schiff:7nyl group, and carba I! J/'
Examples of groups that can be formed by R2 and R3 together with the carbon atoms to which they are bonded include fluorene 7JJl and the like.

Furthermore, examples of the hydrocarbon group for R4 or R6 include alkyl groups such as methyl, ethyl, globyl and butyl groups, aralkyl groups such as benzyl, aryl groups such as phenyl, and substituted products thereof. R4
Or as a substituent on the hydrocarbon group of R6, an alkyl group such as a methyl group, an ethyl group, a glopy group, a butyl group, an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a chlorine atom, a bromine atom, etc. Examples include a norodane atom, a hydroxyl group, and a nitro group. R4
As the phenyl group or the substituent on the ring of X,
- Substituents on the ring that can be formed by 710 gun atoms such as chlorine and bromine atoms, and Y or R20 carbocyclic groups or polycyclic groups, or R2 and R5 include methyl group, ethyl h1 propyl group, butyl group, etc. Alkyl groups, methoxy groups, ethoxy groups, alkoxy groups such as butoxy groups, rhodane atoms such as chlorine atoms and bromine atoms, dialkylamino groups such as dimethylamino groups and diethylamino groups, dibenzylamino groups dialkylamino groups such as, halomethyl groups such as trifluoromethyl groups, metro groups, cyano groups, carboxyl groups or their esters, hydroxyl groups, sulfonic acid groups (-80sN
a) etc. Furthermore, Ar+t or Ar
Examples of the hydrocarbon ring group in 2 include phenyl group and naphthyl group, and substituents on these groups include
Alkyl groups such as methyl group, ethyl group, propyl group, butyl group, alkoxy groups such as methoxy group, ethoxy group, glopoxy group, butoxy group, halogen atoms such as nitro group, chlorine atom, bromine atom, cyano group, dimethylamino group and dialkylamino groups such as diethylamino groups.

Examples of azo pigments used in the present invention are as follows.

(The following is a blank space) -cIJ1'' Width 1 The charge generation layer 3 is a layer mainly composed of an azo pigment represented by the general formula (I), but it can contain a binder if necessary. The proportion of the azo pigment in the generation layer is preferably 30% by weight or more.Since the printing original plate of the present invention elutes the non-image area during the plate-making process, when a binder is used, for example, styrene is used as the binder. - It is preferable to use alkali-soluble resins such as maleic anhydride copolymer, glue-type phenolic resin (described in detail later) - However, if the proportion of binder is small, other resins may be used. The thickness of the charge generation layer 3 is preferably 0.01 to 5 μm, more preferably 0.01 to 5 μm.
．． 05-2 μm. If the thickness is less than 0.01 μm, charge generation will not be sufficient, and if it is more than 5 μm, the residual potential will be too high for practical use.

The charge transport layer 4 is formed of a charge transport substance and an alkali-soluble resin. Charge transport substances include hole transport substances and electron transport substances, and hole transport substances include, for example, 2
,5-bis(4-diethylaminophenyl) -1,3
,4-oxadiazole, 2,5-bis(4-(4-diethylaminostyryl)phenyl)-1,3,4-oxadiazole, 2-(9-ethylcarbazolyl-3-
)-5-(4-diethylaminophenyl) -1,3,
oxadiazole compounds such as 4-oxadiazole;
2-vinyl-4-(2-chlorophenyl)-5-(4-
oxazole compounds such as diethylamino)oxazole, 2-(4-diethylaminophenyl)-4-phenyloxazole, 1-phenyl-3-(4-diethylaminostyryl)-5-(4-diethylaminophenyl)
Pyrazoline, 1-7enyl-3-(4-dimethylaminostyryl)-5-(4-dimethylaminophenyl)-lazolinato pyrazoline compound, 2,2'-dimethyl-
Diphenylmethane compounds such as 4,4'-bis(diethylamino)triphenylmethane, 1,1-bis(4-dibenzylaminophenyl)fronogun, tris(4-diethylaminophenyl)methane, 9-(4-dimethyl Fluorene compounds such as aminobenzylidene)fluorene, 3-(9-fluorene compound)-9-ethylcarbasol, styryl such as 9-(4-diethylaminostyryl)anthracene, 9-bromo-10-(4-diethylaminostyryl)anthracene, etc. anthracene compound, 1
, 2-bis(4-diethylaminostyryl)benzene,
1. Distyrylbenzene compounds such as 2-1's(2,4-dimethoxystyryl)benzene, 9-ethylcarbazole-3-aldehyde 1-methyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde 1-
Benzyl-1-7enylhydrazone, 4-diethylaminobenzaldehyde Ll-diphenylhuman dicine, 2,
Hydrazone compounds such as 4-dimethoxybenzaldehyde 1-benzyl-1-phenylhydrazone, 4-diphenylaminobenzaldehyde 1-methyl-1-phenylhydrazone, 4-dibenzylaminostilpene, 4-dibenzylaminostilpene, 4-diphenylaminobenzaldehyde 1-methyl-1-phenylhydrazone, etc. Stilbene compounds such as 1-fluoraminostilbene, styrylnaphthalene compounds such as 1-(4-diphenylaminostyryl)naphthalene, 1-(4-dibenzylaminostyryl)naphthalene, 4'-diphenylamino-α-ferlstilbene, 4' α-7 enylstilbene compound of -methy/I/phenylamino-α-phenylstilbenato, 3-styryl-9-ethylcarbazole, styryl of 3-(4--/ethylamino)styryl-9-ethylcarbazole'IE Carbazole compounds are used.

Examples of the electron transport substance include chloranil, bromoanil, tetracyanoethylene, tetra7anoquinone dimeta/2,4.7-) dinitro-9-fluorenone, 2,4,5.7-tetranitro-9-fluoreno/
, 2#4t5,7-tetranitroxanthone, 2.4.
8-trinidrothioxanthone, 2.6.8-) dinitro-4H-indenol: 1.2-b, 1thio7
Examples include en-4-one, 1,3.7-)linitrodipenzothio7ene-5,5-dioxide, and the like.

The alkali-soluble material used in the charge transport layer 4 refers to a resin 111tl that becomes soluble in an aqueous or alcoholic solvent by adding an alkali. For the purpose of the present invention,
In addition to properties such as film-forming properties, electrical properties, and adhesion strength to a support, solubility properties are particularly important for these resins. Examples of resins having such characteristics include styrene-maleic anhydride copolymer, styrene/-methacrylic acid-
Examples include methacrylate copolymers, methacrylic acid-methacrylate copolymers, and phenolic resins.

Examples of phenolic resins include phenol, 0-cresol, m-cresol, p-cresol, ethylphenol, isopropylphenol, t-butylphenol, and t-cresol.
-amylphenol, hexylphenol, t-octylphenol, cyclohexylphenol, 3-methyl-4-chloro-6-t-butylphenol, isoglobilcresol, t-butylcresol, t-amylcresol, hexylcresol, t-octylcresol and a nobilac type resin obtained by condensing at least one substituted phenol such as cyclohexyl cresol with an aldehyde such as formaldehyde, acetaldehyde, acrolein, crotonaldehyde, or furfural under acidic conditions.

The charge transport layer 4 is a layer mainly composed of a charge transport substance and an alkali-soluble resin, and the ratio of the charge transport substance in the layer is 10 to 10.
70% by weight, preferably 20-60% by weight. When the proportion of the charge transport substance is below this range, almost no charge is transported, and when it is above this range, the mechanical strength of the layer is extremely poor and cannot be put to practical use. Further, the thickness of the charge transport layer 4 is 2 to 50 μm, preferably 3 to 20 μm. Below this range, the amount of charge will be insufficient, and above this, the residual potential will be high, and it will take time to dissolve the layer, making it impractical. It can be contained.
Effective plasticizers include, for example, 7-talic acid esters such as nomethyl 7-talate, diethyl 7-talate, and dibutyl phthalate, and glycol esters such as dimethyl glycol 7-talate and ethyl 7-talylethyl glycolate.

These plasticizers can be added within a range that does not deteriorate the electrostatic properties and alkali solubility of the photoconductive layer.

The conductive support 1 used in the present invention is an aluminum plate, a zinc plate, or a bimetallic plate such as a copper-aluminum plate, a steel-stainless steel plate, a chrome-steel plate, or a chrome-steel-aluminum plate, a chromium-lead-iron plate. &, chrome-
A conductive support with a hydrophilic surface t-V, such as a tri-metal plate such as a steel-stainless steel plate, is used, and its thickness is 0.
1 to 1 cod is preferred.

In addition, especially in the case of a support having an aluminum surface, surface treatment such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, 7', zirconium oxide, potassium or phosphate, or anodizing treatment can be applied. It is preferable that this is done. Also, as shown in U.S. Patent No. 2,714,066, after graining treatment, sodium silicate water #
gK immersion treated aluminum plate;
It is also preferable to carry out anodization treatment as shown in Japanese Patent No. 7-5125, followed by immersion treatment in water IvfL containing alkali metal silicate.

The above-mentioned anodizing treatment is carried out using, for example, an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, or bolic acid, or an organic acid such as oxalic acid, sulfuric acid, or an electrolytic solution consisting of a solution of a salt thereof. First, a pigment represented by the above general formula (I) and a binder are added as necessary. for example, in an organic solvent such as tetrahydrofuran, dioxane, dimethylformamide, acetone methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethyl acetate, acetic acid II 7", toluene, halodanized hydrocarbon, etc. A coating solution uniformly dispersed by a dispersing means such as Lumil 1 ultrasonic dispersion machine is applied onto the conductive support and dried to provide a charge generation layer 3.Next, a charge transport substance and an alkali-soluble resin are applied. A solution prepared by dissolving .

The plate making of the original printing plate for electrophotographic platemaking of the present invention is carried out by first uniformly charging it in a dark place using a corona charger, etc., using a tungsten lamp, halo cyto/plate, etc., according to the usual electrophotographic method.
Reflective image exposure using a light source such as xeno/lan f or a fluorescent lamp, contact image exposure through a transparent 11i film, or by radar light such as H@-Ne radar, argon laser or semiconductor radar. Scanning exposure is performed to form an electrostatic latent image, and this electrostatic latent image is developed with toner and fixed by heating to obtain a toner image on the electrophotographic photosensitive layer (FIG. 2).

Next, the printing plate on which the toner image has been formed in this way is immersed in an alkaline eluent, and the non-image areas that are not covered by the toner image are immersed in the photosensitive layer (charge generation layer and charge transport layer). ) is dissolved and removed, the hydrophilic surface of the conductive support is exposed, and only the toner image portion remains, making it possible to obtain a good printing plate (Figure 3).

The eluent used here is, for example, an alkaline aqueous solution of an inorganic salt such as sodium silicate, sodium phosphate, sodium hydroxide, or sodium carbonate, an alkaline aqueous solution containing organic amines such as triethanolamine or ethylenediamine, or an alkaline aqueous solution containing organic amines such as triethanolamine or benzyl alcohol. , a solution containing an organic solvent such as ethylene glycol or glycerin or a surfactant is used.

In the printing plate of the present invention, after the toner image is formed, the non-image area is dissolved and removed in the eluent, so the toner components include:
It is preferable that this eluate contains a resin component having resist properties.

This resin component may be anything that is insoluble in the eluate; for example, acrylic resin using methacrylic acid, methacrylic acid ester, vinyl acetate resin, copolymer of vinyl acetate and ethylene or vinyl chloride, etc. , vinyl chloride resin, vinylidene chloride resin, vinyl acetal resin such as polypiertstyral, polystyrene, copolymers of styrene and butadiene, methacrylic acid ester, polyethylene, polyglozelene and its chloride, polycargonate, Polyester resin, polyamide resin, phenolic resin, xylene resin, alkyd resin,
These include wax, polyolefin, and wax.

The printing original plate of the present invention may also contain a quinone diacid compound such as O-naphthoquinone diazide or a diazo compound for the purpose of increasing the solubility of the electrophotographic photosensitive layer by full-surface exposure after toner image formation.

In the printing original plate of the present invention, after the manufacturing process is completed, the conductive substrate with a hydrophilic surface is exposed in the non-image area, and the image area covered with oleophilic toner remains. The ink adheres only to the image area, resulting in good printed matter without scumming.

In addition, the printing original plate of the present invention has the following characteristics compared to conventional printing original plates:
Especially sensitive, H@-N@! /-day, direct a version is possible with various light sources such as semiconductor laser,
The printing plate thus obtained has high printing durability.

Next, the present invention will be explained in more detail with reference to Examples.

In addition, all "parts" in the examples represent parts by weight.

Example 1 One part of Azo Pigment Grave 5 was mixed with m-cresol-7-Nol copolymerization. 0.0 of lac resin (MP-707 manufactured by Guneikai).
74wt titet 2 hydrofuran solution ffL 66.7 parts?
- Grind and mix the resulting dispersion in a Lumir to a thickness of about 0.2
5■ Apply on grained aluminum plate 8
A charge generation layer with a thickness of about 1 μm was formed by drying at 0°C for 10 minutes. 2,5-bis(2,5-bis(
4-diethylaminophenyl) -1,3,4-oxadiazole 0.9 parts, 1.8 parts of styrene-maleic anhydride copolymer (copolymerization molar ratio 1:1 manufactured by Aldritto Chemical Kanno Yanie) and tetrahydrofuran13.
A solution obtained by mixing and dissolving two parts was applied and dried at 80° C. for 20 minutes to form a charge transport layer having a thickness of about 10 μm, thereby producing a printing original plate for electrophotographic engraving of the present invention.

Regarding this original printing plate, electrostatic copy zero paper testing equipment (Co., Ltd.)
-6 using Kawaguchi Electric's new product: 5P-428 type).
After performing a kV corona discharge for 20 seconds to charge it negatively, it was discharged for 10 seconds in a dark place, and the surface potential vo
(−root) was measured, and then the illuminance of the surface by a tungsten lamp was calculated to be 4.5 lux (lux·sec). The results are shown in Table 1.Next, this printing original plate was applied to an electronic copy plate making machine (Ricoh S-1).
A clear toner image was formed on the charge transport layer by charging, imagewise exposure, development and fixing.

This original plate was mixed with 70 g of sodium metasilicate and 14 g of glycerin.
0 Tug, ethylene glycol 550d, and ethanol 1501j for 1 minute, and was further washed with a water jet while lightly brushing to remove the electrophotographic photosensitive layer in the non-image area where no toner was attached.

The printing plate made in this way is then printed on an offset printing machine (
When printing was carried out in a conventional manner using Ricoh's Ap-t3io, more than 50,000 clear prints could be printed.

Examples 2 and 3 Printing for electrophotographic printing of the present invention was carried out in the same manner as in Example 1, except that the compounds shown in Table IK were used as the azo pigment used in the charge generation layer and the charge transport substance used in the charge transport layer, respectively. An original plate was prepared, and vo and E strength were measured.

The above results are shown in Table-1.

(The following is a blank space) Example 4 1 part of azo pigment 4 was mixed with 0.0 parts of m-cresol-7-ethanol copolymerized lac resin (MP-707 manufactured by Gunei Chemical Co., Ltd.).
74wt% nato5hyT: 179yffffL66
．． 7 parts were pulverized and mixed in a ♂-Lumill, the resulting dispersion was applied onto a grained aluminum plate with a thickness of about 0.25 mm, and dried at 80°C for 10 minutes to form a powder with a thickness of about 1 μm.
An Oml charge generation layer was formed.

3-styryl- as a charge transport substance on this charge generation layer.
9-ethylcarhasonyl 1.5 parts, m-/resol-7
Enol copolymerized nodelac resin (manufactured by Gunei Chemical: MP-
707) A solution prepared by mixing and dissolving parts a and o and 12.0 parts of tetrahydrofuran is applied, and dried at 80°C for 2 minutes and then at 100°C for 10 minutes to form a charge transport layer with a thickness of about 10 μm. The printing original plate for electrophotographic engraving of the present invention was prepared quickly. Regarding this printing original plate, as in Example 1, vo
and EH measurement results are shown in Table 2.

Next, a toner image was formed on the electrophotographic photosensitive layer of this printing original plate in the same manner as in Example 1, and then immersed in a solution of 2.5 parts of sodium metasilicate and 100 parts of water for about 45 seconds.
Furthermore, the electrophotographic photosensitive layer in the non-image area was removed by washing while lightly brushing with water.

When the printing plate made in this way was printed on an offset printing machine, it was possible to print more than so, ooo pages of clear printed matter. A printing original plate for electrophotographic engraving of the present invention was prepared in the same manner as in Example 4, except that the compounds shown in Table 2 were used as charge transport substances, and vo and Eμ were measured.

The above results are shown in Table-2.

(Margin below)

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic structure of the printing original plate for electrophotographic engraving of the present invention. FIGS. 2 and 3 are diagrams explaining the plate-making process of the printing original plate of the invention. The figure shows a state in which a toner image has been formed, and FIG. 3 shows a state in which a non-image area has been eluted and removed. 1. Conductive support, 2. Electrophotographic photosensitive layer, 3.
... Charge generation layer, 4... Charge transport layer, 5... Toner image. Patent applicant Rico Co., Ltd. - Figure 1 To Figure 2 Figure 3

Claims (1)

[Claims] An electronic device consisting of two layers, a charge generation layer containing an azo pigment represented by the following general formula (I) and a charge transport layer containing a charge transport substance and an alkali-soluble resin, on a conductive support. A printing original plate for electrophotographic engraving, characterized by being provided with a photosensitive layer. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, A in the formula represents a coupler residue.)