JPH08106183A - Direct drawing type planographic printing plate material - Google Patents

Abstract

PURPOSE: To provide a material for a direct drawing type planographic printing plate so that a plate can be produced by using an electrostatic transfer type copying machine or the like and that good printing can be performed without producing blisters. CONSTITUTION: This plate material consists of a waterproof supporting body, an image receiving layer containing zinc oxide and a resin as the main component which is formed on the one surface of the waterproof supporting body, and a back layer formed on the other surface of the supporting body. The back layer contains aluminum hydroxide and kaolin as a pigment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic transfer system such as a copying machine or a laser printer, or a thermal transfer printer, a typewriter, or a plate material for direct drawing type lithographic printing plates for making a plate by hand drawing. More specifically, the present invention relates to a direct-drawing type planographic printing plate material in which no blister is generated in the electrostatic transfer type plate making process.

[0002]

2. Description of the Related Art With the recent development of office equipment and the progress of office automation, in the light printing field, a direct drawing type planographic printing plate material that can be easily plate-made by a copying machine, a laser printer, a thermal transfer printer, etc. is used. Printing methods are rapidly spreading. A conventional direct-drawing type planographic printing plate material is one in which an image receiving layer made of an inorganic pigment, a water-soluble resin, a water-proofing agent, etc. is provided on a support made of paper, plastic film, etc. which has been subjected to water resistance treatment. Is. In such a direct drawing type lithographic printing plate material, a lipophilic ink is used to form a lipophilic image on the image receiving layer by a typewriter or handwriting, or a toner formed on an electrophotographic photoreceptor. The image can be transferred to the image receiving layer and heat-fixed to form a lipophilic image, or the image can be heat-melt transferred from an ink ribbon with a thermal transfer printer to form a lipophilic image. Such a direct drawing type printing plate material becomes a printing plate by desensitizing the non-image portion of the printing plate material with an etching solution.

In the direct drawing type planographic printing plate material, it is necessary to provide a back layer on the side opposite to the image receiving layer side in order to improve water resistance and prevent curling. If the back layer is not provided, the curl is severe and it is difficult to use, the printing durability is poor, and the plate elongation (dimensional stability) is also significantly poor.
As a direct drawing type planographic printing plate material having a back layer,
For example, JP-A-57-205196 and JP-A-61-16
No. 0294, JP-A-62-48597, JP-A-62-
It is disclosed in publications such as 48597. The conventional direct drawing type planographic printing plate material has a drawback that blisters are generated in an electrostatic transfer type plate making machine. This is because the water in the plate material for direct drawing type planographic printing becomes water vapor due to heating during toner fixing in the plate-making process, but it is sealed in the plate material by the image receiving layer and the back layer. Due to this blister, the plate surface may become uneven, and the plate material may fail to be fed in the plate making machine, or may not be usable as a direct drawing type planographic printing plate material.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a lithographic printing plate material for direct drawing which does not cause blisters in the plate making process of the electrostatic transfer system.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventor found that the above problems can be solved by using aluminum hydroxide in combination as a pigment in the back layer. The present invention has been reached.

That is, the direct drawing type planographic printing plate material of the present invention comprises a water resistant support, and an image receiving layer formed on one surface of the water resistant support and containing zinc oxide and a resin as main components. A back layer formed on the opposite surface of the water resistant support, the back layer containing aluminum hydroxide and kaolin as pigments.

Although the mechanism by which the formation of blisters is prevented by including aluminum hydroxide and kaolin in the back layer is not clear, the plate material for direct drawing type lithographic printing plate is heated by fixing the toner during plate making. It is considered that the water vapor generated inside became easy to move out of the plate material through the back layer.

In the direct drawing type planographic printing plate material of the present invention,
The content of aluminum hydroxide contained in the back layer is preferably 10 to 60% by weight based on the total dry weight of the back layer. It is more preferably 20 to 50% by weight. If the content of aluminum hydroxide is less than 10% by weight, blistering cannot be prevented, and if it exceeds 60% by weight, sufficient water resistance cannot be obtained. The content of kaolin contained in the back layer is 1 with respect to the total dry weight of the back layer.
It is preferably from 0 to 60% by weight. It is more preferably 20 to 50% by weight. If the content of kaolin is less than 10% by weight, sufficient water resistance cannot be obtained, and if it is more than 60% by weight, blister generation cannot be prevented.

A water-soluble resin and / or a water-dispersible hydrophobic resin can be used as the resin used for the back layer in the plate material for direct drawing lithographic printing of the present invention. The resin content is 10 to 80% by weight based on the total dry weight of the back layer.
Is preferable, and more preferably 20 to 70% by weight. However, if a large amount of water-soluble resin is blended, the water resistance will be lowered too much and the dimensional stability will be deteriorated. Therefore, the water-soluble resin content is preferably 5% by weight or less.

Examples of the water-soluble resin include polyvinyl alcohol, oxidized starch, modified starch, gum arabic, gelatin, casein, chitosan, methyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose,
Polyvinylpyrrolidone, polyacrylic acid salt, polyacrylic amide, styrene-maleic anhydride copolymer salt, methyl vinyl ether-maleic anhydride copolymer salt, isopropylene-maleic anhydride copolymer salt and the like can be used. Of course, it is not limited to these. Examples of the hydrophobic resin include styrene-butadiene latex, emulsion of vinyl acetate-acrylic acid ester copolymer, polyurethane emulsion, polyvinyl chloride emulsion, polyvinylidene chloride emulsion, emulsion of methacrylic acid ester copolymer and acrylic acid. There are emulsions of ester copolymers. Of course, it is not limited to these.

If necessary, an auxiliary additive component such as a dispersant, a conductive agent, or a waterproofing agent for strengthening water resistance may be added to the back layer. Examples of the water-proofing agent include glyoxal, glutaraldehyde, expensive aldehyde compounds such as dialdehyde starch, polyamine compounds such as polyethyleneimine,
Epoxy compounds, polyamide resins, diglycidyl compounds such as glycerin diglycidyl ether, dimethylol urea compounds, and inorganic compounds such as ammonium persulfate, ferric chloride, and magnesium chloride, or boric acid, borax may be used. it can. Of course, it is not limited to these.

Examples of the conductive agent include cationic conductive resins such as polyvinylbenzyltrimethylammonium chloride, polydimethyldiallylammonium chloride, and styreneacrylic acid trimethylaminoethyl chloride copolymer, polystyrene sulfonate, polyacrylate, Examples thereof include anionic conductive resins such as polyvinyl sulfonate, carbon black, and conductive whiskers. Of course, it is not limited to these.

To form the back layer in the present invention,
Apply a water-based paint containing the above materials to one surface of the support,
This coating layer is dried and solidified to form a film. At this time, preferably, drying at a temperature of 80 to 150 ° C. can form a water resistant back layer. The dry weight of the back layer is preferably in the range of 3 to 30 g / m ² . More preferably, it is 5 to 20 g / m ² . 3 g / m
^If it is less than ² , sufficient water resistance cannot be obtained and the curl becomes large. Also, if it is more than 30 g / m ² , the curl becomes too large. The back layer coating material may be applied by a method such as a Mayer bar method, an air knife method, a blade method, a reverse roll method, a slit die method, or the like. Of course, it is not limited to these.

The support used in the present invention is, for example, paper,
Examples thereof include a laminated sheet of paper and aluminum foil or a polyethylene film, paper having a vapor-deposited metal layer, synthetic paper and the like. If a paper is used for the support of the present invention, the paper is mainly a chemical pulp, and a wet paper strength agent such as urea melamine resin and epichlorohydrin resin, and a sizing agent such as modified rosin and alkyl ketene dimer are added. preferable.
In addition, size press treatment may be performed for the purpose of adjusting electric conductivity and facilitating coating of various paints. Of course, it is not limited to these.

In order to improve the water resistance of the direct drawing type planographic printing plate material, a water resistant layer may be provided between the support and the image receiving layer. Such a water resistant layer is made of resin, pigment or the like.
In addition, if necessary, an auxiliary additive component, for example, a dispersant, a conductive agent, and a water resistant agent for strengthening water resistance may be added. As the resin, pigment, dispersant, conductive agent, and water resistant agent used in the water resistant layer of the present invention, for example, the same materials as those used in the back layer can be used.

The dry weight of the water resistant layer is 3 to 30 g / m.
It is preferably within the range of ² . More preferably 5
It is 20 g / m ² . If it is less than 3 g / m ² , sufficient water resistance cannot be obtained. If it is more than 30 g / m ² , the curl becomes too large. As the coating method of the water resistant layer coating material, the same method as for the back layer can be used.

In the direct drawing type planographic printing plate material of the present invention,
The content of total zinc oxide contained in the image receiving layer is preferably 70% by weight or more, and more preferably 75 to 90% by weight, based on the total dry weight of the image receiving layer.
When the content of total zinc oxide is less than 70% by weight, the desensitizing ability is poor, and printing stains are likely to occur.

The resin used in the image receiving layer is
Water-soluble resins such as starch, starch derivatives, cellulose derivatives such as carboxymethyl cellulose and hydroxymethyl cellulose, polyvinyl alcohol, modified polyvinyl alcohol, casein, and ammonium acrylate,
It is also possible to use water-insoluble and water-dispersible emulsion type resins such as acrylic resins, SBR, NBR, and vinyl acetate-ethylene copolymers. These resins may be used alone or in combination of two or more. Can be used together. When only the above water-soluble resin is used as the resin, it is preferable to use an appropriate amount of a water-proofing agent in combination with it in order to improve the printing durability of the direct drawing type printing plate material obtained. Further, as other resins used in the image receiving layer, polyester resin, acrylic resin, epoxy resin,
Examples thereof include solvent-soluble (water-insoluble) resins such as polycarbonate resin and butyral resin. In this case, the coating material for the image receiving layer can be prepared using a solvent such as toluene.

The content of the resin in the image receiving layer is preferably 30% by weight or less, and more preferably 10 to 25% by weight, based on the total dry weight of the image receiving layer.
When the resin content exceeds 30% by weight, desensitization of the non-image area of the obtained direct drawing type planographic printing plate material is insufficient and stains are likely to occur during printing. The dry weight of the image receiving layer of the direct drawing type planographic printing plate material of the present invention is 4 to 20.
It is preferably g / m ² . Below 4 g / m ² ,
The desensitizing ability of the obtained direct drawing type planographic printing plate material becomes insufficient, and printing stains easily occur. Also, 20 g / m
^When it exceeds ² , the cost becomes high, the surface electric resistance becomes large, and the toner fog is deteriorated in the electrostatic transfer type plate making. The method for applying the image receiving layer coating material is
The same method as for the back layer can be used.

[0020]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited by these. In addition, "parts" and "%" in Examples are "parts by weight" and "% by weight", respectively, unless otherwise specified.
Represents

Example 1 A coating material having the following composition was applied on one surface of a substrate made of wet-strengthened and internally-added paper to give a dry weight of 15 g / m ^2.
Was coated and dried to form a back layer. Back layer-forming composition Ingredient Weight aluminum hydroxide dispersion paints (50% solids, trademark: HIGILITE H-42, manufactured by Showa Denko) 45 parts Kaolinite clay dispersion (50% solids, trademark: Hydro Gloss 90, manufactured by Huber) 45 parts Emulsion type acrylic resin (solid content 45%, trademark: Bonron S-482, manufactured by Mitsui Toatsu Kagaku) 45 parts Water 50 parts

Next, on the surface of the paper substrate opposite to the back layer surface,
A paint having the following composition was applied so that the dry weight was 10 g / m ² and dried to form a water resistant layer on the image receiving layer side. Composition Ingredient Weight of water-resistant layer forming coating kaolinitic clay dispersion (50% solids, trademark: Hydro Gloss 90, made by Huber) 30 parts of emulsion type acrylic resin (40% solids, trademark: ARON A-104 , Manufactured by Toagosei Kagaku Kogyo Co., Ltd.) 50 parts SBR (solid content 50%, trademark: Nipol LX-415, manufactured by Zeon Corporation) 40 parts water 50 parts

Next, the following composition was prepared and dispersed by a sand grinder, and the coating composition was applied onto the water resistant layer so that the dry weight was 7 g / m ² , and the image receiving Layers were formed. Composition Ingredient Weight zinc oxide of the image receiving layer forming coating material (TM: SAZEX # 2000, manufactured by Sakai Chemical Industry Co.) 86 parts of acrylic resin (50% solids, trademark: ACRYDIC A-405, manufactured by Dainippon Ink & Chemicals ) 28 parts Toluene 86 parts The plate material for direct drawing type lithographic printing plate thus prepared was subjected to 10 plate making using a laser printer (trademark: LBP-B406E, made by Canon), and blisters did not occur. The case was evaluated as ○, and the case of occurrence even in the 1st version was evaluated as ×. Further, when the blister did not occur, printing was performed using a printing machine (trademark: 3200CD, manufactured by Ryobi). The results are shown in Table 1.

Example 2 A coating material having the following composition was applied to a back surface of a substrate made of paper which was wet-strengthened and internally added in a size of 15 g / m ^{2 in} dry weight.
Was coated and dried to form a back layer. Back layer-forming composition Ingredient Weight aluminum hydroxide dispersion paints (50% solids, trademark: HIGILITE H-42, manufactured by Showa Denko KK) 60 parts Kaolinite clay dispersion (50% solids, trademark: Hydro Gloss 90, manufactured by Huber) 30 parts Emulsion type acrylic resin (solid content 45%, trademark: Bonron S-482, manufactured by Mitsui Toatsu Kagaku) 20 parts Water 50 parts

Next, the same water-proof layer and image receiving layer as in Example 1 were provided, and the direct drawing type planographic printing plate material prepared was subjected to plate making in the same manner as in Example 1 to evaluate the blister. . The results are shown in Table 1. Comparative Example 1 A coating material having the following composition was applied on a back surface of a substrate made of paper which was wet-strengthened and internally sized to have a dry weight of 15 g / m ^2.
Was coated and dried to form a back layer. Back layer forming composition Ingredient paint Weight kaolinitic clay dispersion (50% solids, trademark: Hydro Gloss 90, made by Huber) 90 parts emulsion type acrylic resin (solid content 45%, trademark: Bonron S-482, Mitsui Toatsu Chemicals Co., Ltd.) 45 parts Water 50 parts Next, the same water-resistant layer and image receiving layer as in Example 1 were provided, and the direct drawing type planographic printing plate prepared was prepared by the same method as in Example 1. Plate making was performed and the blister was evaluated. The results are shown in Table 1.

Comparative Example 2 A coating material having the following composition was applied on a back surface of a substrate made of paper which was wet-strengthened and internally-added size, and had a dry weight of 15 g / m ^2.
Was coated and dried to form a back layer. Back layer-forming composition Ingredient Weight aluminum hydroxide dispersion paints (50% solids, trademark: HIGILITE H-42, manufactured by Showa Denko KK) 90 parts emulsion type acrylic resin (solid content 45%, trademark: Bonron S -482, manufactured by Mitsui Toatsu Kagaku Co., Ltd.) 45 parts Water 50 parts Next, a direct drawing type planographic printing plate material prepared by providing the same water resistant layer and image receiving layer as in Example 1 was used. Plate making was carried out by the method of 1 above and the blister was evaluated. The results are shown in Table 1.

Comparative Example 3 A coating material having the following composition was applied to a back surface of a substrate made of paper which was wet-strengthened and internally added in a dry weight of 15 g / m ^2.
Was coated and dried to form a back layer. Composition Ingredient Weight mica dispersion of the back layer-forming coating material (50% solids) 45 parts emulsion type acrylic resin (solid content 45%, trademark: Bonron S-482, manufactured by Mitsui Toatsu Chemicals) 45 parts Water 50 parts Next, the same water resistant layer and image receiving layer as in Example 1 were provided, and the direct drawing type planographic printing plate material prepared was subjected to plate making in the same manner as in Example 1 to evaluate the blister. The results are shown in Table 1.

Comparative Example 4 A coating material having the following composition was applied to a back surface of a substrate made of paper which was wet-strengthened and internally sized to have a dry weight of 15 g / m ^2.
Was coated and dried to form a back layer. Back layer-forming coating composition Ingredient Weight talc dispersion (50% solids) 45 parts emulsion type acrylic resin (solid content 45%, trademark: Bonron S-482, manufactured by Mitsui Toatsu Chemicals) 45 parts Water 50 parts Next, the same water resistant layer and image receiving layer as in Example 1 were provided, and the direct drawing type planographic printing plate material prepared was subjected to plate making in the same manner as in Example 1 to evaluate the blister. The results are shown in Table 1.

[0029]

[Table 1]

[0030]

According to the present invention, a direct-drawing type planographic printing plate material in which blisters do not occur in the plate making process by the electrostatic transfer system was obtained. This printing material largely contributes to the rationalization of office printing and light printing fields.

Claims (1)

[Claims] 1. A water resistant support, an image receiving layer formed on one surface of the water resistant support and containing zinc oxide and a resin as main components, and formed on the opposite surface of the water resistant support. And a back layer, the back layer containing aluminum hydroxide and kaolin as pigments, a direct-drawing type lithographic printing plate material.