JPH06186789A - Base material for electrophotographic planographic printing original plate - Google Patents

Abstract

PURPOSE:To provide the base material for an electrophotographic planographic printing original plate which does not generate the peeling and plate elongating by blister at the time of plate making and dampening water at the time of printing and has excellent heat resistance and water resistance. CONSTITUTION:This base material for the electrophotographic planographic printing original plate is constituted by laminating an intermediate layer and a photoconductive layer contg. a photoconductive material on one surface of metal foil laminated paper formed by applying adhesives to both surfaces of metallic oil and sticking papers thereto. The metallic foil is hard aluminum foil which is not annealed. The adhesives dissolved in an org. solvent having <30dyne/cm surface tension (20 deg.C) are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a blister for plate making,
The present invention relates to a base material for an electrophotographic lithographic printing plate precursor that has excellent heat resistance and water resistance without causing peeling and plate elongation due to dampening water 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 water resistance and conductivity. As the substrate, a sheet-like substance such as paper, metal foil, film or a composite thereof is used. When using paper, the paper is subjected to a water resistance treatment to improve the electrophotographic image. Therefore, an intermediate layer containing an inorganic electrolyte such as sodium chloride, potassium chloride, calcium chloride or the like, or an organic polymer electrolyte such as a quaternary ammonium salt, which is usually called a conductive agent, is provided.

However, even when an electrophotographic lithographic printing plate precursor is produced using a paper thus treated as a base material, dampening water is applied during printing and plate elongation cannot be avoided. Problems such as wrinkles, misregistration of printed matter, and rounded dimensions of ruled lines occur.

Instead of paper, for example, Japanese Patent Publication No. 38-172
No. 49, No. 41-2426, No. 41-12432, etc., aluminum, zinc,
By using paper (hereinafter referred to as metal foil laminated paper) with a metal foil such as copper bonded with an adhesive, it is possible to improve elongation and tensile strength in the wet state, and to obtain an electrophotographic lithographic printing plate precursor with good dimensional stability. Obtainable.

The metal foil laminated paper is usually produced by adhering one side of the metal foil to the paper, but it may be produced by adhering both sides of the metal foil to the paper, and any metal foil laminated paper is used. Even so, it is possible to obtain an electrophotographic lithographic printing plate precursor having good dimensional stability.

As the adhesive agent for the metal foil and the paper, a vinyl acetate resin, an acrylic resin, a polyolefin resin, a polyurethane resin or the like is usually used in an emulsion state or a solution state. Water-soluble resins such as casein, poval, and starch are also used as adhesives.

In addition, as a laminating method, a hot-melt method using a resin such as wax resin, polyolefin resin (polyethylene, polypropylene, ethylene-vinyl acetate copolymer resin, ionomer, etc.) which is melted by heating, extrusion coating Laws are also used.

Regarding the adhesion between the metal foil and the paper, blisters (interruption between layers also called blisters) do not occur due to softening of the adhesive or insufficient adhesive force during heat fixing of the developer during plate making, and printing. At the same time, it is necessary that dampening water penetrates from the end surface of the electrophotographic lithographic printing original plate to lower the adhesive strength, and the metal foil-paper is peeled off so that the electrophotographic lithographic printing original plate is not destroyed.

Therefore, the metal foil laminated paper produced by the hot melt method or the extrusion coating method is unsuitable in terms of blister generation during plate making. In addition, JP-A-58-
As disclosed in Japanese Patent Nos. 16892 and 58-17449, etc., an acrylic resin emulsion and a synthetic rubber resin or a synthetic resin emulsion and casein are mixed at a constant ratio as an adhesive between metal foil and paper. When the above-mentioned one is used, the adhesive strength between the metal foil and the paper is improved to some extent. However, even using these methods, it was not possible to completely prevent the peeling between the metal foil and the paper due to the blister during plate making or the dampening water during printing.

On the other hand, with respect to the metal foil, the higher the tensile strength thereof, the smaller the elongation of the electrophotographic lithographic printing original plate at the time of printing. Therefore, it is desirable to use a hard metal foil which is not annealed rather than an annealed soft metal foil. However, JP-A-58-3649
As shown in Japanese Patent Publication No. 4, when the wetting index of the surface of the metal foil is low, the adhesive strength between the metal foil and the paper is lowered, and the blister is generated during plate making and the metal foil is dampened during printing. A hard metal foil that does not anneal and has rolling oil remaining on its surface could not be used because peeling between papers is likely to occur.

[0011]

DISCLOSURE OF THE INVENTION The present invention has excellent heat resistance and water resistance, which does not cause peeling and plate elongation due to blister during plate making or dampening water at the time of printing, which could not be realized by such prior art. It is an object of the present invention to provide a base material for an electrophotographic lithographic printing plate precursor having the above.

[0012]

DISCLOSURE OF THE INVENTION The inventors of the present invention have studied the effect of the types of metal foil and adhesive on the adhesion between metal foil and paper and the plate elongation during printing, and as a result, a hard aluminum foil that is not annealed. It was found that when an adhesive agent dissolved in an organic solvent having a low surface tension is applied and laminated on paper, the tensile elongation when wet is small and the adhesiveness between the metal foil and the paper is remarkably improved. Therefore, the surface tension at 20 ° C. is 30 dyne / c on the hard aluminum foil that is not annealed.
When an adhesive dissolved in an organic solvent of less than m is applied and both sides are laminated with paper, and an intermediate layer and a photoconductive layer are provided thereon, a blister during plate making and a metal foil with dampening water during printing It was found that a base material for an electrophotographic lithographic printing plate precursor having excellent heat resistance and water resistance, which does not cause separation between papers and plate elongation, was obtained, and completed the present invention.

The metal foil used in the present invention is preferably a hard aluminum foil which has high tensile strength and is not annealed in order to suppress plate elongation of the electrophotographic lithographic printing plate precursor. It is also possible to wash the surface of the hard aluminum foil with an organic solvent in order to increase the wetting index and improve the adhesiveness.

The adhesive used in the present invention is preferably dissolved in an organic solvent having a surface tension at 20 ° C. of 30 dyne / cm or less. In the adhesive dissolved or dispersed in a solvent having a surface tension at 20 ° C. of more than 30 dyne / cm, the wetting index of the hard aluminum foil that is not annealed due to the rolling oil remaining on the surface is low,
The adhesive strength between the metal foil and the paper decreases, and blister during plate making and peeling with dampening water during printing are unavoidable.

As the adhesive, a vinyl acetate-based, acrylic-based, polyurethane-based resin or the like can be used. Above all, a polyurethane-based adhesive is preferable because it has high adhesive strength and does not require heating to improve the adhesive strength.

The surface tension at 20 ° C. is 30 dyne /
As the organic solvent having a size of cm or less, acetone, acetonitrile, benzene, chloroform, ethyl acetate, ethyl alcohol, ethyl ether, n-hexane, isopropyl alcohol, methyl alcohol, methyl ethyl ketone,
n-Propyl alcohol, toluene, etc. can be used. Of these, methyl ethyl ketone, acetone, ethyl acetate and the like are preferably used because they have a relatively low boiling point and are less dangerous to the human body.

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 applying the adhesive. Of these, a gravure coater and a reverse roll coater are preferable from the viewpoint of coating liquid viscosity and coating amount.

The surface to which the adhesive is applied may be either a metal foil or a paper. When the metal foil is thin, in order to prevent the metal foil from wrinkling due to the shrinkage of the adhesive during drying. , It is preferable to apply an adhesive to the paper surface, and if the paper surface is not subjected to solvent resistance treatment, it is adhered to the metal foil surface to prevent the adhesive from penetrating into the paper layer together with the solvent. It is preferable to apply the agent.

If the coating amount of the adhesive is extremely small, sufficient adhesion between the metal foil and the paper cannot be obtained.
In particular, one side to be laminated is paper, and the surface has many micro irregularities, and it is unavoidable that part of the adhesive penetrates into the paper layer. Therefore, the coating amount is at least 1 g / m ² or more is required. If the coating amount is less than this, the coating of the coating surface with the adhesive will be insufficient, and the adhesive strength between the metal foil and the paper will be partially reduced. When it is strongly heated during plate making, it cannot withstand the generation of water vapor and the expansion of air from the inside of the paper layer, and blisters occur between the metal foil and the paper. The upper limit of the coating amount is naturally limited by the performance of the laminator, the surface properties of the paper, or the economical efficiency.

In the present invention, the paper laminated with the metal foil is a coating solution containing an adhesive and a conductive substance such as a water-soluble resin or a synthetic emulsion in order to reduce fog during plate making under low humidity conditions. It is preferably surface-treated. As such water-soluble resin or synthetic resin emulsion, starch or its derivative, cellulose or its derivative, polyvinyl alcohol, styrene-butadiene latex, acrylic resin emulsion, vinyl acetate resin emulsion, etc. can be used. In addition, as the conductive substance, an inorganic electrolyte such as sodium chloride, potassium chloride, calcium chloride, or polyvinylbenzyl type 4
Conductive resins such as primary ammonium salt, polyacrylic acid type quaternary ammonium salt, polystyrene sulfonic acid sodium salt, and sodium polyacrylate can be used.

The coating liquid mainly composed of such a water-soluble resin or synthetic emulsion and a conductive substance is applied to the surface of the raw paper by a size press device, a gate roll coater or the like.

In the present invention, the intermediate layer is provided to enhance the water resistance and conductivity of the base material. In the intermediate layer, pigments such as clay, sericite, calcium carbonate, styrene-
Synthetic resin adhesives such as butadiene latex, acrylic resin emulsion, vinyl acetate resin emulsion, water-soluble adhesives such as starch and polyvinyl alcohol, sodium chloride, potassium chloride, calcium chloride, polyvinylbenzyl type quaternary ammonium salt, poly Acrylic acid type quaternary ammonium salt, polystyrene sulfonate sodium salt, conductive agent such as sodium polyacrylate, water resistant agent such as melamine-formalin resin, polyamide resin and epoxy resin are included.

The intermediate layer is applied to the surface of the 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, an air knife coater or the like. The coating amount of the intermediate layer is usually 5 to 3
It is about 0 g / m ² .

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

The photoconductive layer is coated on the intermediate layer by a reverse roll coater, a rod coater, a die coater, a curtain coater or the like. The coating amount of the photoconductive layer is usually about 15 to 30 g / m ² .

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. Such backing layers include pigments such as clay, sericite and calcium carbonate, synthetic resin adhesives such as styrene-butadiene latex, acrylic resin emulsion, vinyl acetate resin emulsion, water-soluble starch and polyvinyl alcohol. Adhesive, sodium chloride, potassium chloride, calcium chloride, polyvinylbenzyl type quaternary ammonium salt, polyacrylic acid type quaternary ammonium salt, polystyrene sulfonate sodium salt, conductive agent such as sodium polyacrylate, melamine-formalin resin, A water resistant agent such as a polyamide resin or an epoxy resin is included.

The backing layer is formed on the surface of the paper opposite to the intermediate layer by a size press machine, a gate roll coater, a reverse roll coater, a gravure coater, a rod coater, a die coater, a curtain coater, an air knife coater or the like. Is applied. The coating amount of the backing layer is usually about 5 to 30 g / m ² .

[0028]

In the present invention, when a metal foil laminated paper obtained by applying an adhesive dissolved in an organic solvent having a low surface tension to a hard aluminum foil that is not annealed and laminating it with paper is used as a base material, the tensile elongation when wet is increased. Since it becomes smaller and the adhesiveness between the metal foil and the paper is significantly improved, excellent heat resistance and water resistance that does not cause peeling between the metal foil and paper and plate elongation due to a blister during plate making or dampening water during printing. A substrate for electrophotographic lithographic printing plate precursor having properties is obtained.

[0029]

EXAMPLES Next, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. The parts and% shown below are based on weight.

Example 1 On one side of a hard aluminum foil which was not annealed and which was shown in JIS-H4160 temper (H-18) having a thickness of 10 μm, an adhesive having the following composition was applied at a dry coating amount of 3.0 g / m ^2. And coated with a commercially available high-quality paper having a basis weight of 50 g / m ² . After this aluminum foil laminated paper was left at room temperature for 2 days to be aged at room temperature, an adhesive having the following composition was applied to the other aluminum foil surface so that the dry coating amount was 3.0 g / m ^2. Laminated with fine paper. This aluminum foil laminated paper was left at room temperature for 2 days to be aged at room temperature. [Composition 1] Polyester polyol resin (BLS-PC21, Toyo Morton, solid content 35%) 15 parts Polyisocyanate (CAT-100, Toyo Morton, solid content 50%) 1 part Methyl ethyl ketone 3 parts

Next, on one side of this aluminum foil laminated paper, an intermediate layer having the following composition was applied in a dry coating amount of 10 g / m ^2.
Was applied and dried. Inorganic pigment containing sericite (Jakelite TMC, made by Jakelite Kagaku, 50% water dispersion) 100 parts Calvoxyl modified SBR latex (48% solid content) 50 parts Melamine resin initial condensate (Sumires Resin-613, Sumitomo Chemical, solid Min 80%) 4 parts Organic amine salt catalyst (Sumitex Accelerator ACX-P, Sumitomo Chemical, solid content 35%) 0.4 parts Polystyrene sulfonate ammonium (solid content 30%) 4 parts

Further, a backing layer having the following composition was coated on the side opposite to the intermediate layer of this aluminum foil laminated paper so that the dry coating amount was 15 g / m ² and dried. Kaolin (Hydrapers, manufactured by Huber, 50% aqueous dispersion) 100 parts Inorganic pigment containing sericite (Sikelite TMC, manufactured by Sikelite Chemical, 50% water dispersion) 100 parts Oxidized starch (10% aqueous solution) 60 parts Carboxyl modified SBR latex (solid content 48%) 150 parts Polystyrene sulfonic acid ammonium salt (solid content 30%) 6 parts Melamine resin initial condensate (SUMIRETSU RESIN-613, Sumitomo Chemical, solid content 80%) 4 parts

Next, the dry coating amount on the surface of the intermediate layer was 20 g /
A photoconductive layer having the following composition was formed so as to have m ² to prepare an electrophotographic lithographic printing plate precursor. Zinc oxide for electrophotography 200 parts Acrylic resin (50% liquid) 80 parts Rose Bengal (2% methanol solution) 15 parts Xylene 250 parts

Example 2 A base material for an electrophotographic lithographic printing plate precursor was produced in exactly the same manner as in Example 1 except that the adhesive was changed to the following. [Composition 2] Polyester polyol resin (Takelac A606, manufactured by Takeda Pharmaceutical) 9 parts Aromatic isocyanate (Takenate A12, manufactured by Takeda Pharmaceutical) 1 part Ethyl acetate 2 parts

Example 3 A base material for an electrophotographic lithographic printing plate precursor was prepared in exactly the same manner except that the adhesive used in Example 1 was changed to the one described below. [Composition 3] Polyester polyol resin (Takelac A606, Takeda Pharmaceutical Co., Ltd.) 9 parts Aromatic isocyanate (Takenate A12, Takeda Chemical Co., Ltd.) 1 part Acetone 2 parts

Comparative Example 1 A base material for an electrophotographic lithographic printing plate precursor was produced in exactly the same manner except that the adhesive used in Example 1 was changed to the following. [Composition 4] Acrylic ester resin aqueous emulsion (Mobinyl 987, Hoechst Synthetic)

Comparative Example 2 Electrophotographic lithographic printing was carried out in the same manner as in Example 1 except that a soft aluminum foil represented by JIS-H4160 temper (H-0) having a thickness of 10 μm was used instead of the hard aluminum foil in Example 1. A base material for an original plate was produced.

Comparative Example 3 An electrophotographic lithographic printing plate precursor was prepared in exactly the same manner except that the adhesive used in Comparative Example 2 was changed to the composition 1 used in Comparative Example 1.

This electrophotographic lithographic printing plate precursor is
Seasoned under the conditions of ℃ -60% RH and 20 ℃ -20% RH, electrophotographic plate making machine Diafax EP
Plate-making was performed with -31V (Mitsubishi Paper Milling, plate making machine for liquid development).

Next, it was desensitized with an etch liquid Diafax LOM-OHII (manufactured by Mitsubishi Paper Mills) for electrophotographic offset masters, and printed with an offset printer Toko Model 810 (manufactured by Tokyo Aviation Keiki).

20 ° C.-60% RH and 20 ° C.-20% R
There is no fog under any of the conditions of H,
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. When printing with dampening water applied, 10
It was confirmed that the plate for electrophotography lithographic printing plate precursor obtained by the present invention was extremely excellent without causing plate elongation and peeling of the photosensitive layer even after printing 000 sheets or more.

The electrophotographic lithographic printing plate precursors produced in Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated by the following evaluation methods, and the evaluation results are shown in Table 1. The numbers in the section of the surface tension of the solvent of the adhesive in Table 1 are dyne / cm.
The unit of is shown. The evaluation method is as follows. [Blisters at the time of plate making] Regarding the blisters at the time of plate making, the presence or absence of blisters at the time of plate making with an electrophotographic plate making machine Diafax EP-31V (made by Mitsubishi Paper Mills, a plate making machine for liquid development) was visually evaluated. [Plate Elongation] Regarding plate elongation, the difference in size between the electrophotographic lithographic printing plate precursor after printing 4000 sheets was evaluated using the produced electrophotographic lithographic printing plate precursor and Toko Model810 offset printing machine (manufactured by Tokyo Aviation Keiki Co., Ltd.). , Indicated by the elongation rate. [Aluminum foil-base paper peeling during printing] The aluminum-base paper peeling during printing in Table 1 indicates aluminum foil-base paper peeling. For this item, the presence or absence of peeling during printing using the printing machine Was visually evaluated.

[0043]

[Table 1]

In Examples 1 to 3, an electrophotographic lithographic plate having excellent heat resistance and water resistance, in which blister during plate making and delamination between aluminum foil and base paper due to dampening water during printing and plate elongation did not occur. A base material for a printing original plate was obtained.
In Comparative Example 1, since a hard aluminum foil having a low surface wettability is used, compatibility with an adhesive containing a solvent having a high surface tension is poor, the adhesiveness is extremely lowered, and blister during printing, printing At that time, delamination between the aluminum foil and the base paper occurred. Further, in Comparative Example 2, since a soft aluminum foil having a low tensile strength was used, plate elongation occurred during printing. In Comparative Example 3, since a soft aluminum foil having a low tensile strength and an adhesive containing a solvent having a high surface tension were used, blister during plate making or delamination between the aluminum foil and the base paper during printing and plate elongation occurred. .

[0045]

As is clear from the above description, according to the present invention, since blisters do not occur during plate making, and the water resistance to dampening water is also improved, the printing durability is greatly improved. A substrate for an electrophotographic lithographic printing original plate is obtained.

Claims (1)

[Claims] 1. An electrophotographic lithographic printing plate precursor comprising a metal foil laminated paper obtained by applying an adhesive to both sides of a metal foil, and laminating an intermediate layer and a photoconductive layer containing a photoconductive substance on one side of the paper. Material, the metal foil is a hard aluminum foil that is not annealed, and the adhesive is dissolved in an organic solvent having a surface tension (20 ° C.) of less than 30 dyne / cm. Base material for lithographic printing plate.