JPH054465A - Substrate for electrophotography lithographic printing original plate - Google Patents

Abstract

PURPOSE:To provide an electrophotography system lithographic printing original plate with excellent electrophotographic characteristics and wear resistance, by which fog does not generate when plate making is performed under a low humidity condition, blister does not generate at the time of plate making, and ply separation, etc., between metallic foil and a base paper due to entering of damping water does not generate at the time of printing, for an electrophotography system lithographic printing original plate which uses a metallic foil laminated paper, which is obtained by laminating a metallic foil and a base paper by an adhesive, as the substrate. CONSTITUTION:On the surface of a base paper, which is joined to a metallic foil by the dry laminate method, a coated layer with a volume resistance value of 1.0X10<12>cm or less shall be provided by a dry coat weight of 0.5g/m<2> or more, under a condition of 10 deg.C and 15%RH. If a metallic foil laminated paper, for which a base paper which has a coated layer with a low volume resistance value on the surface is laminated with a metallic foil in this manner, is used as the substrate, the reduction of conductivity of the substrate is less even under a low humidity condition, and therefore, an electrophotography lithographic printing original plate with an excellent electrophotographic characteristics, by which fog does not generate at the time of plate making, can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base material for an electrophotographic lithographic printing plate precursor having excellent plate life with little plate elongation during printing.

[0002]

2. Description of the Related Art Generally, an electrophotographic lithographic printing plate precursor is constructed by providing a layer containing an inorganic or organic optical semiconductor on a substrate having properties such as conductivity and water resistance. Is used as a sheet material such as paper, metal foil, film, or a composite material thereof. When using paper, the paper is treated with water resistance, and a conductive material is used to improve the electrophotographic image. Is added.

However, when a lithographic printing plate precursor is prepared by using a paper thus treated as a base material, dampening water is applied during printing, so that plate elongation cannot be avoided even if water resistant treatment is applied. . As a result, problems such as wrinkles on the plate during printing, misregistration of the printed matter, and rounded dimensions of ruled lines occur.

If a paper in which a metal foil such as aluminum, zinc or copper is adhered with an adhesive (hereinafter referred to as a metal foil laminated paper) is used instead of paper, elongation and tensile strength in wet can be improved. It is possible to obtain a printing original plate having good dimensional stability (see, for example, Japanese Examined Patent Publication No. 38).
-17249, 41-2426, 41-124
No. 32 publication).

Usually, the metal foil laminated paper is produced by adhering one side or both sides of the metal foil to the paper with an adhesive, but it is industrially widely used as the adhesive between the metal foil and the paper. For example, vinyl acetate resin, acrylic resin, polyolefin resin, polyurethane resin, etc. are used. These are applied as a water-based paint in the form of an emulsion or as a solvent-based paint by selecting an appropriate solvent between the metal foil and the paper and laminated. In addition, water-soluble resins such as casein, poval, and starch can be used as the adhesive. In addition, as a laminating method, a hot-melt method using a resin that melts by heating, such as a wax resin or a polyolefin resin (polyethylene, polypropylene, ethylene-vinyl acetate copolymer resin, ionomer, etc.), an extrusion coating method, etc. It is used well.

The inventors of the present invention produced an electrophotographic lithographic printing original plate using a metal foil laminated paper as a base material and investigated its practicality. The physical properties were found to be the following three points.

(1) During plate making, blister (interruption between layers also called blistering) does not occur due to insufficient adhesive strength between metal foil and base paper and internal bond strength of base paper during heat fixing of toner.

(2) At the time of printing, immersion water penetrating from the end surface of the printing original plate reduces the adhesive strength between the metal foil and the base paper and the internal bond strength of the base paper, resulting in delamination between the metal foil and the base paper or in the base paper. What does not happen.

(3) During plate making, especially in low humidity conditions,
Fogging (a phenomenon in which toner adheres to non-image areas) does not occur due to the decrease in conductivity due to the decrease in water content.

If a mixture of an acrylic resin emulsion and a synthetic rubber resin or a synthetic resin aqueous emulsion and casein is mixed at a fixed ratio as the adhesive between the metal foil and the base paper, the adhesive strength between the metal foil and the base paper is improved. It has already been reported that the above points (1) and (2) can be improved to some extent (Japanese Patent Laid-Open Nos. 58-16892 and 58-1).
7449). Also, by adding a chemical such as a wet strength agent to the base paper to improve the internal bond strength of the base paper,
Improvements in points (1) and (2) have also been made. Regarding the point (3), when the plate is made in a low humidity condition, the water content of the base material is lowered and the conductivity is lowered, and the electric charge remains in the non-image area where the electric charge should disappear by exposure. Therefore, it is known that fogging is likely to occur. Using a water-soluble resin for the adhesive between the metal foil and the base paper,
It is possible to suppress fogging to some extent by imparting water retention to the adhesive layer and increasing the conductivity, but it is easy to cause delamination between the metal foil and the base paper due to blister during plate making or dampening water during printing. Become. As described above, the conventional technology cannot completely prevent the occurrence of blisters during plate making, delamination between the metal foil and the base paper due to dampening water during printing, and fogging during plate making under low humidity conditions. there were.

[0011]

DISCLOSURE OF THE INVENTION The present invention provides a blister at the time of plate making, a delamination between the metal foil and the base paper by dampening water at the time of printing, and a plate making at a low humidity condition which could not be realized by such a conventional technique. It is an object of the present invention to provide a base material for an electrophotographic lithographic printing plate precursor that has good printing durability and good electrophotographic characteristics without causing fog or the like.

[0012]

Means for Solving the Problems The present inventors have examined the relationship between the characteristics of the base paper adhered to the metal foil and the fog during plate making. As a result, the conductivity and low humidity of the surface of the base paper adhered to the metal foil are examined. It was revealed that there is a close relationship with the fogging when the plate was made under the conditions. That is, when an electrophotographic lithographic printing original plate is prepared by using a base material having a high surface resistance value laminated with a metal foil as a base material, the conductivity of the base material is remarkably lowered under low humidity conditions, and fogging occurs during plate making. However, when an electrophotographic lithographic printing original plate is prepared by using a base material having a low surface resistance value laminated with a metal foil as a base material, the electroconductivity of the base material is not significantly reduced even in a low humidity condition, and fogging during plate making is prevented. It turns out that it does not occur. Therefore, by providing a coating layer containing a conductive substance on the surface of the base paper to suppress the surface resistance value and laminating it with a metal foil, electrophotographic characteristics and printing durability of fog-free printing can be achieved even when plate making is performed under low humidity conditions. It was found that a good substrate for electrophotographic lithographic printing plate precursor can be obtained, and the present invention has been achieved.

In the present invention, the base paper having a low surface resistance value means that the surface of the base paper adhered to the metal foil is 15 ° C. and 10% R.
The coating layer has a volume resistance value of 1.0 × 10 ¹² Ωcm or less under the condition of H, but the volume resistance value of the coating layer exceeds 1.0 × 10 ¹² Ωcm. If it is high, fog cannot be avoided when the plate is made under low humidity conditions.

In the present invention, the coating layer having a volume resistance value of 1.0 × 10 ¹² Ωcm or less under conditions of 15 ° C. and 10% RH, which is provided on the surface of the base paper adhered to the metal foil, is mainly water-soluble. An adhesive containing a resin or a synthetic resin emulsion and a conductive substance is preferable. Therefore, as the water-soluble resin or synthetic resin emulsion used, starch and its derivatives, cellulose and its derivatives, polyvinyl alcohol, styrene butadiene latex, acrylic resin emulsion, vinyl acetate resin emulsion and the like are preferable.

As the conductive substance, inorganic electrolytes such as sodium chloride, potassium chloride and calcium chloride,
Conductive resin such as polyvinylbenzyl type quaternary ammonium salt, polyacrylic acid type quaternary ammonium salt, polystyrene sulfonic acid sodium salt, polyacrylic acid sodium salt, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene alkyl Nonionic surfactants such as ethers, polyoxyethylene alkylphenyl ethers, glycerin fatty acid esters, sorbitan fatty acid esters, anionic surfactants such as sodium alkyl sulfonates, sodium alkylbenzene sulfonates, sodium alkyl sulfates, sodium alkyl phosphates, etc. Agents, cationic surfactants such as alkyl quaternary ammonium salts, and amphoteric surfactants such as alkyl betaine type, alkyl imidazoline type, and alkyl alanine type. It can be used.

Further, a pigment, a cross-linking agent, a sizing agent or the like may be added to the coating layer, if necessary, in order to improve the barrier property against water or an organic solvent.

In the present invention, when the dry coating amount of the coating layer is too small, it is difficult to uniformly coat the base paper surface, so that the dry coating amount is preferably 0.5 g / m ² or more. The upper limit of the coating amount is naturally limited by the surface properties of the paper or the economical efficiency.

In the present invention, the coating layer is applied to the surface of the raw paper by a size press device, a gate roll coater, a reverse roll coater, a gravure coater, a rod coater, a die coater, a curtain coater, a blade coater, etc. In consideration of the above, a size press device or a gate roll coater suitable for on-machine coating is preferable.

In the present invention, in order to enhance the adhesiveness between the metal foil and the base paper, after the coating layer is provided, the surface of the base paper is smoothed by a machine calender, super calender, gloss calender, soft nip roll calender, Yankee dryer or the like. Is preferable.

The metal foil used in the present invention prevents reduction in elongation and tensile strength when the base paper layer is impregnated with a conductive layer necessary for forming an image by an electrophotographic method and a fountain solution during printing. It has a dual role of a support layer, and if the metal is thinned to meet this purpose,
Any material may be used. For example, it is a single composition of iron, copper, tin, aluminum, lead, zinc or the like, or an alloy thereof. Among them, aluminum is preferred as the material to be laminated on the base paper because of its small specific gravity and light weight, good spreadability, and easy processing into foil, but of course the present invention is not limited to this. It is not something that will be done.

In the present invention, the adhesion between the metal foil and the base paper is
The dry laminating method is preferable to the glue laminating method in that the water resistance and heat resistance are remarkably excellent. Generally, in the dry lamination method, heating aging is performed in order to accelerate the rise of adhesion, but at this time, oxidation of the metal foil surface or adhesion of organic matter occurs, and an intermediate layer between the substrate and the image receiving layer is generated. When a layer is provided, the adhesiveness of the metal foil-intermediate layer is reduced, or when the base paper is laminated on both sides of the metal foil, the metal foil-
Since the adhesiveness between the base papers is reduced, it is preferable to use a room temperature curable adhesive that does not require heating aging.

A gravure coater, a roll coater, a rod coater, a die coater, a curtain coater, a blade coater or the like can be used for the application of the adhesive, but the gravure coater or the reverse roll coater is used in view of the viscosity of the coating liquid and the coating amount. Is preferred.

The surface to which the adhesive is applied may be either a metal foil or a base paper, but when the metal foil is thin, in order to prevent wrinkles from occurring on the metal foil due to shrinkage of the adhesive during drying, It is preferable to apply an adhesive to the raw paper surface.

If the amount of adhesive applied is extremely small, sufficient adhesion between the metal foil and the base paper cannot be obtained. Especially when one side of the paper is laminated, at least 1 g /
A coating amount of m ² or more is required. If the coating amount is less than this, the coating of the coated surface with the adhesive will be insufficient, and the adhesive strength between the metal foil and the base paper will be partially reduced. Then, when it is strongly heated during plate making, it cannot withstand the generation of water vapor from the base paper layer and the expansion of air, and blister occurs between the metal foil and the base paper. The upper limit of the coating amount is naturally limited by the performance of the laminator, the surface properties of the base paper, or the economical efficiency, but in the practical range, it is preferably in the range of 1 to 10 g / m ² .

In the present invention, a synthetic resin emulsion is usually used in the intermediate layer, and if necessary, clay, sericite,
It is applied by mixing with a pigment such as calcium carbonate, a water-soluble resin such as starch or polyvinyl alcohol, a conductive agent, a cross-linking agent, or the like.

In the present invention, the image receiving layer refers to an image formed by an electrophotographic method, and contains an optical semiconductor as its basic component. Usually zinc oxide,
An inorganic optical semiconductor such as titanium dioxide or cadmium sulfide dispersed in an insulating adhesive resin, or an organic optical semiconductor such as polyvinylcarbazole is used.

In the present invention, a backing layer may be provided on the side of the substrate opposite to the image receiving layer in order to enhance water resistance and conductivity of the substrate. The resin emulsion is optionally mixed with a pigment such as clay, sericite or calcium carbonate, a water-soluble resin such as starch or polyvinyl alcohol, a conductive agent, a cross-linking agent and the like, and applied.

[0028]

In the present invention, when a metal foil laminated paper obtained by laminating a base paper having a low surface resistance value with a metal foil is used as a base material, the conductivity of the base material is not deteriorated even under a low humidity condition, and fogging occurs during plate making. An electrophotographic lithographic printing plate precursor having excellent electrophotographic characteristics can be obtained.

[0029]

EXAMPLES Next, the present invention will be described in more detail by way of examples. The parts and% shown below are based on weight.

Example 1 (1) Preparation of low volume resistance coating liquid and measurement of volume resistance value A coating liquid having the following composition was prepared, and a dry coating amount was 5.0 g / m ² on an aluminum foil having a thickness of 50 μm. After coating and air drying, the volume resistance was 7.8 × 10 ⁸ Ωcm when measured with a Hewlett Packard 16008A type resistivity cell under the conditions of 20 ° C. and 65% RH. (Composition 1) Oxidized starch (5% aqueous solution): 99 parts Styrenic resin sizing agent (Polymaron 385, manufactured by Arakawa Chemical Industry, solid content 25%): 0.5 part Sodium chloride: 0.5 part

(2) Preparation of electrophotographic lithographic printing original plate A high-quality paper having a basis weight of 100 g / m ² was coated with a coating solution of composition 1 by a size press device so that the dry coating amount was 2.1 g / m ² . After drying, it was smoothed using a machine calendar. An adhesive for dry lamination having the following composition was coated on this base paper so that the dry coating amount was 3.0 g / m ^2, and an aluminum foil having a thickness of 10 μm was laminated. This aluminum foil laminated paper was left at room temperature for 2 days and aged at room temperature. Polyester polyol resin (BLS-PC21, Toyo Morton, solid content 35%): 15 parts Polyisocyanate (CAT-100, Toyo Morton, solid content 50%): 1 part Ethyl acetate: 3 parts

Next, an intermediate layer having the following composition was applied on the aluminum foil side of the aluminum foil laminated paper at a dry coating amount of 10 g / m ^2.
Was applied and dried. Sericite-containing inorganic pigment (Zyklite TMC, manufactured by Zyklite Chemical Co., 50% aqueous dispersion): 100 parts carboxyl-modified SBR latex (solid content 48%):
100 parts oxidized starch (solid content 25%): 20 parts melamine resin initial condensate (SUMIRETS RESIN-613,
Sumitomo Chemical, solid content 80%): 4 parts organic amine salt catalyst (Sumitex Accelerator A)
CX-P, manufactured by Sumitomo Chemical, solid content 35%): 0.4 part

On the side opposite to the intermediate layer of the aluminum foil laminated paper, a back coating layer having the following composition is applied at a dry coating amount of 15 g / m.
^It was applied and dried so as to be ² . Kaolin (Hydrasperth, manufactured by Huber, 50% aqueous dispersion): 100 parts Inorganic pigment containing sericite (Zyklite TMC, manufactured by Zyklite Chemical, 50% aqueous dispersion): 100 parts Oxidized starch (25% aqueous solution): 60 Part carboxyl modified SBR latex (solid content 48%):
150 parts Ammonium polystyrene sulfonate (solid content 30
%): 6 parts melamine resin initial condensate (SUMIREZ RESIN-613,
Sumitomo Chemical, solid content 80%): 4 parts

Furthermore, the dry coating amount on the surface of the intermediate layer is 20 g.
A photoconductive layer having the following composition was applied so as to be / m ² and dried. Zinc oxide for electrophotography: 200 parts Acrylic resin (50% liquid): 80 parts Rose Bengal (2% methanol solution): 15 parts Xylene: 250 parts

This electrophotographic lithographic printing plate precursor was kept at 15 ° C. for 1
Seasoning was carried out under a low humidity condition of 0% RH, and plate making was carried out by an electrophotographic plate making machine Diafax EP-31V (made by Mitsubishi Paper Mills, a plate making machine for liquid development).

Next, desensitization treatment was carried out with an etch solution for electrophotographic offset master, Diafax LOM-OHII (manufactured by Mitsubishi Paper Mills), and the offset printing machine Toko Model was used.
It was printed with 810 (manufactured by Tokyo Airlines Keiki).

No fogging or blistering occurred even when the plate was made under low humidity conditions of 15 ° C. and 10% RH, and a clear image with high sensitivity was obtained. No curling occurs even after the etchant treatment, and it can be mounted on the printing machine by a smooth operation. Even when printing more than 10000 sheets when dampening water is applied, the plate stretches and the aluminum foil- It was confirmed that the printing plate obtained according to the present invention was extremely excellent without any delamination between the base papers or peeling of the photosensitive layer.

Example 2 (1) Preparation of low volume resistance coating liquid and measurement of volume resistance value A coating liquid having the following composition was prepared, and a dry coating amount was 5.0 g / m ² on an aluminum foil having a thickness of 50 μm. Thus, the volume resistance was measured by a Hewlett Packard 16008A type resistivity cell under the conditions of 20 ° C. and 65% RH after air-drying, and it was 6.9 × 10 ¹¹ Ωcm. (Composition 2) Oxidized starch (5% aqueous solution): 99 parts Styrene resin sizing agent (Polymaron 385, manufactured by Arakawa Chemical Industry, solid content 25%): 0.5 part Sodium polystyrene sulfonate (solid content 30%):
0.5 copy

(2) Preparation of electrophotographic lithographic printing original plate A high-quality paper having a basis weight of 50 g / m ² was coated with a coating solution of composition 2 by a size press device so that the dry coating amount was 1.8 g / m ² . After drying, it was smoothed using a machine calendar. Example 1 was applied to one side of an aluminum foil having a thickness of 10 μm.
Of dry laminating adhesive is 3.0g /
It was coated so as to be m ² and laminated with this base paper.
After this aluminum foil laminated paper was left at room temperature for 2 days to be aged at room temperature, the dry laminating adhesive of Example 1 was applied to the other aluminum foil surface at a dry coating amount of 3.0 g.
It was coated so as to be / m ² and laminated again with this base paper. This aluminum foil laminated paper was left at room temperature for 2 days and aged at room temperature.

Next, an intermediate layer having the following composition was coated on one side of this aluminum foil laminated paper so that the dry coating amount was 15 g / m ² , and dried. Sericite-containing inorganic pigment (Zyklite TMC, manufactured by Zyklite Chemical Co., 50% aqueous dispersion): 100 parts carboxyl-modified SBR latex (solid content 48%):
50 parts melamine resin initial condensate (Smirates resin-613,
Sumitomo Chemical, solid content 80%): 4 parts organic amine salt catalyst (Sumitex Accelerator A)
CX-P, manufactured by Sumitomo Chemical, solid content 35%): 0.4 parts Ammonium polystyrene sulfonate (solid content 30)
%): 4 copies

On the side opposite to the intermediate layer of this aluminum foil laminated paper, the back coating layer of Example 1 was applied at a dry coating amount of 15 g /
It was applied and dried so as to be m ² .

Further, the dry coating amount on the surface of the intermediate layer is 20 g.
The photoconductive layer of Example 1 was applied so as to be / m ² and dried to prepare a printing plate.

Example 3 (1) Preparation of low volume resistance coating liquid and measurement of volume resistance value A coating liquid having the following composition was prepared, and a dry coating amount of aluminum foil having a thickness of 50 μm was 5.0 g / m ² . Thus, the volume resistance was measured by a Hewlett Packard 16008A type Resistivity Cell under the conditions of 20 ° C. and 65% RH after air-drying, and it was 2.6 × 10 ⁹ Ωcm. (Composition 3) Kaolin (hydrapers, manufactured by Huber, 50% aqueous dispersion): 100 parts carboxyl-modified SBR latex (solid content 48%):
50 parts oxidized starch (25% aqueous solution): 50 parts melamine resin initial condensate (SUMIREZ RESIN-613,
Sumitomo Chemical, solid content 80%): 3 parts Ammonium polystyrene sulfonate (solid content 30)
%): 4 copies

(2) Preparation of electrophotographic lithographic printing plate precursor: A high-quality paper having a basis weight of 50 g / m ² was coated with a coating liquid of composition 3 by a gate roll coater so that the dry coating amount was 6.5 g / m ² . After drying, it was smoothed using a super calendar. The dry coating amount of the adhesive for dry laminating of Example 1 was applied to one side of an aluminum foil having a thickness of 10 μm.
It was coated at 0 g / m ² and laminated with this base paper. This aluminum foil laminated paper is left at room temperature for 2 days to be aged at room temperature, and then the dry laminating adhesive of Example 1 is applied to the other aluminum foil surface in a dry coating amount of 3.0 g / m ² . And then laminated again with this base paper. This aluminum foil laminated paper at room temperature 2
It was left to stand for a day for aging at room temperature.

Next, on one side of this aluminum foil laminated paper, the intermediate layer of Example 2 was applied and dried so that the dry coating amount was 15 g / m ² .

On the side opposite to the intermediate layer of this aluminum foil laminated paper, the backing layer of Example 1 was applied at a dry coating amount of 15 g /
It was applied and dried so as to be m ² .

Furthermore, the dry coating amount on the surface of the intermediate layer is 20 g.
The photoconductive layer of Example 1 was applied so as to be / m ² and dried to prepare a printing plate.

Comparative Example 1 (1) Preparation of high volume resistance coating liquid and measurement of volume resistance value Acrylic ester resin aqueous emulsion (Movinyl 987, Hoechst Synthetic, solid content 45%) with a thickness of 50 μm
^{2. The} volume resistance was measured by a Hewlett Packard 16008A type resistivity cell under the conditions of 20 ° C. and 65% RH after air-drying so that the dry coating amount was 5.0 g / m ² . It was 4 × 10 ¹³ Ωcm.

(2) Preparation of electrophotographic lithographic printing original plate A fine paper having a basis weight of 100 g / m ² was dried with a size press machine so that the dry coating amount of the acrylic ester resin aqueous emulsion was 2.3 g / m ^2. After coating and drying, the product was smoothed using a machine calendar. The base paper was coated with the dry laminating adhesive of Example 1 so that the dry coating amount was 3.0 g / m ^2, and an aluminum foil having a thickness of 10 μm was laminated. This aluminum foil laminated paper was left at room temperature for 2 days and aged at room temperature.

Next, the intermediate layer of Example 1 was applied to the aluminum foil side of this aluminum foil laminated paper at a dry coating amount of 15 g / m ^2.
Was applied and dried.

On the side opposite to the intermediate layer of this aluminum foil laminated paper, the back coating layer of Example 1 was applied at a dry coating amount of 15 g /
It was applied and dried so as to be m ² .

Furthermore, the dry coating amount on the surface of the intermediate layer is 20 g.
The photoconductive layer of Example 1 was applied so as to be / m ² and dried to prepare a printing plate.

Comparative Example 2 A high-quality paper having a basis weight of 50 g / m ² was coated with a coating solution of the composition (2) by a gate roll coater so that the dry coating amount was 0.3 g / m ² , and dried. It was smoothed using a calendar. On one side of aluminum foil with a thickness of 10 μm,
The dry laminating adhesive of Example 1 was applied so as to have a dry coating amount of 3.0 g / m ² and laminated on this base paper. This aluminum foil laminated paper is left at room temperature for 2 days to be aged at room temperature, and then the dry laminating adhesive of Example 1 is applied to the other aluminum foil surface in a dry coating amount of 3.0 g / m ² . And then laminated again with this base paper. This aluminum foil laminated paper was left at room temperature for 2 days and aged at room temperature.

Next, on one side of this aluminum foil laminated paper, the intermediate layer of Example 2 was applied and dried so that the dry coating amount was 15 g / m ² .

On the side opposite to the intermediate layer of this aluminum foil laminated paper, the back coating layer of Example 1 was applied at a dry coating amount of 15 g /
It was applied and dried so as to be m ² .

Furthermore, the dry coating amount on the surface of the intermediate layer is 20 g.
The photoconductive layer of Example 1 was applied so as to be / m ² and dried to prepare a printing plate.

Comparative Example 3 The adhesive for dry lamination in Example 1 was changed to the following adhesive for glue lamination, and the dry coating amount was 3.0.
A printing plate was prepared in the same manner as in Example 1 with g / m ² . Acrylic ester resin aqueous emulsion (Movinyl 987, Hoechst synthesis, solid content 45%): 100 parts

The evaluation results are collectively shown in Table 1. The fog in the table is determined by visually observing the plate-making product under the low humidity condition, and the blister during plate-making changes depending on the preheating state of the plate-making machine heater part or the heater temperature control scale, so the heater part is the same as room temperature. The plate was judged by performing plate making in a state where the plate was cooled to 0 ° C. and the heater temperature control scale was in a state just between the upper limit and the lower limit.

[0059]

[Table 1]

From the results shown in Table 1, it is clear that in Examples 1 to 3, fogging during plate making under low humidity conditions, blisters during plate making, and delamination during printing did not occur. However, in the case of Comparative Example 1, since a coating layer having a high volume resistance value was applied, fogging occurred during plate making under low humidity conditions. Further, in the case of Comparative Example 2, since the coating amount of the coating layer having a low volume resistance value was small and the entire surface of the paper could not be covered, partial fogging occurred during plate making under low humidity conditions. . Further, in the case of Comparative Example 3, since the adhesive for the metal foil and the paper was changed from the adhesive for dry lamination to the adhesive for glue lamination, blister during plate making and delamination during printing occurred.

[0061]

As is apparent from the above description, according to the present invention, the fog in the case of plate making under a low humidity condition,
Electrophotographic planographic printing using a metal foil laminated paper as a base material, which has excellent electrophotographic characteristics and printing durability such that blisters during plate making and delamination between metal foil and base paper due to penetration of dampening water during printing do not occur. A substrate for a printing original plate is obtained.

Claims (3)

[Claims] 1. A photoconductive material, which is made of a metal foil laminated paper prepared by adhering one or both sides of a metal foil to a base paper with an adhesive, directly on the metal foil laminated paper or through an intermediate layer. In a base material for an electrophotographic lithographic printing original plate provided with an image receiving layer containing a substance, the volume of 1.0 × 10 ¹² Ωcm or less on the surface of the raw paper adhered to the metal foil under the conditions of 15 ° C. and 10% RH. A base material for an electrophotographic lithographic printing plate precursor, which is provided with a coating layer having a resistance value. 2. The dry coating amount of the coating layer is 0.5 g / m.
^The base material for an electrophotographic lithographic printing plate precursor according to claim 1, which is ² or more. 3. The base material for an electrophotographic lithographic printing plate precursor according to claim 1, wherein the metal foil and the base paper are bonded by a dry lamination method.