JPS61154849A - Manufacture of processed plate material for lithographic printing - Google Patents

Abstract

PURPOSE:To enable plate making directly from a copy on a plate material for lithographic printing and to eliminate processings such as developing, exposing, washing, etc., by laminating an electrothermosensitive transfer plate making material and a plate material for lithographic printing which has a certain surface resistance and by applying electricity from the side of a resin layer which contains a certain amount of metal and has a certain surface resistance. CONSTITUTION:An electrothermosensitive transfer plate making material is prepared by lamination of a resin layer containing metal which consists of metal powder and resin matrix, and which contains 5-60% by volume of metal powder and has an electric surface resistance of 10<5>-10<16>OMEGA, and a breakdown of which would not occur at the time of electric plate making; and thermal transfer layer which consists of a thin metal film with a surface resistance of 0.1-1OMEGA, and has a conductive layer of which a breakdown would not occur at the time of electric plate making, and consists of a thermosetting resin and a hardening agent, and which is not yet thoroughly thermoset. The above plate making material is laminated so that the thermal transfer layer should abut the surface of the plate material for lithographic printing. The thermal transfer layer is transferred to the plate surface by heat generated by the application of electricity from the side of the metal containing resin layer and, at the same time, an image is formed by setting the transferred thermosetting resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a lithographic printing plate material subjected to current IB thermal transfer upplate making.

[Conventional technology]

Lithographic printing is widely used because it allows large-sized printing, and PS plates and electrophotographic plates are commonly used as printing plates.

A PS plate is a plate with a photosensitive resin layer laminated on a polished aluminum plate. A photographic film of the original is prepared in advance, coated on the PS plate, and then printed.
Plate making is done by washing and eluting the non-photosensitive areas (soluble areas), leaving the photosensitive areas (insoluble areas) ("Printing Engineering Handbook" for the Printing Society of Japan, Gihodo Publishing Co., Ltd.) Publication, pp. 490-492).

However, in the above-mentioned plate-making method, steps such as development, exposure, and washing are troublesome, and it is difficult to dispose of washing waste liquid.

Furthermore, an electrophotographic plate is one in which a photosensitive semiconductor layer such as selenium or zinc oxide is laminated on a base material such as paper. Direct plate making is possible (see the above “Printing Engineering Handbook” 192-1)
(page 93).

However, plates made using this plate-making method cannot be used to print a large number of copies, and electrophotographic copying machines, electrophotographic engraving machines, and the like have disadvantages in that they are large and expensive.

[Problem that the invention seeks to solve]

In view of the above-mentioned drawbacks, the present invention enables direct plate-making from an original onto a lithographic printing plate material such as an aluminum plate using a conventionally known discharge recorder or plate-making machine such as a facsimile or computer terminal, and allows for development, exposure, and cleaning. It is an object of the present invention to provide a method for producing a plate material for lithographic printing, which does not require the above steps and can print a large number of copies.

[Means for solving problems]

The metal powder used in the present invention means a metal in powder form, and the powder must have electrical conductivity. It is preferable to use a powder of a highly conductive metal, and specific examples of suitable metal powders include powders of copper, aluminum, iron, pot, lead, nickel, molybdenum, silver, bronze, brass, and the like.

Further, metal powder coated with other metals can also be used, such as copper powder coated with silver. Among the metal powders mentioned above, copper, zinc, and iron are preferably used.

It is best to have uniform particle sizes, with an average particle size of o, 2 to 20.
Micron ones are preferred, more preferably Q5-10
It is micron.

The resin matrix used in the present invention only needs to have film-forming ability and electrical insulation, and thermoplastic resins are preferably used. It is desirable to use a material that is large in size, has high mechanical strength when formed into a sheet or film, is flexible, and is strong, such as polyethylene, polypropylene, polyvinyl chloride, vinyl, ethylene-vinyl acetate copolymer, etc. Polyvinyl chloride-vinyl acetate copolymer, polystyrene, polyacrylonitrile, polyvinyl acetal, polyacrylic acid ester, polymethacrylate ester, polyester, cellulose acetate, polyurethane, polyvinyl alcohol, carboxymethylcellulose, gelatin, etc., polyethylene, Polyvinyl chloride, vinyl chloride-ethylene copolymer, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal, cellulose acetate, and polyurethane are preferably used.

The metal-containing resin layer (5) of the current-carrying I8 thermal transfer plate-making material in the present invention is a layer that is not destroyed by electrical discharge during the current-carrying plate-making process, and the metal-containing resin layer (5) is made of IJ Fuchs metal powder. One or more metal powders may be selected and used depending on the
If the amount added is too small, the conductivity will be low, and if the amount added is too large, the conductivity will be too good, and the current applied from the recording needle will diffuse and become difficult to flow directly under the recording needle, and even worse. Metal-containing resin Ji! (The layer is determined to have a surface resistance of 5 to 60% by volume of Al and a surface resistance of 10s to 1016Ω, preferably 107 to 1014Ω.Also, the thickness of the layer is not particularly limited, but Preferably, it is between 5 and 50 microns.

The metal-containing resin layer cA) is made of an electrically conductive thermal transfer plate-making material, and during electrical plate-making, it is brought into contact with a recording needle and subjected to electrical plate-making, so there is no risk that the metal-containing resin layer (4) will cause cracks, etc. plasticizers, fillers, lubricants, stabilizers, antioxidants, and flame retardants to improve storage stability, prevent constituent substances from adhering to the recording needle, and further improve the formability of the layer. etc. may be added.

The method for forming the metal-containing resin layer (5) is not limited in any way, and any known method such as a solution casting method, an emulsion casting method, a calendering method, an extrusion method, etc. may be employed.

The thickness of the metal-containing fat layer is not particularly limited, but it is preferably 5 to 50μ.
This is a layer that will not be destroyed by electrical discharge during electrification plate making, and if the surface resistance is too small, the amount of heat generated will be small, and if it is too large, it will be destroyed when energized. Therefore, it is set to 0.1 to 1Ω.

In addition, if the difference in surface resistance between the metal-containing resin layer (4) and the conductive layer (B) is small, the amount of heat generated during electrical plate making will decrease, so the surface resistance and conductivity of the metal-containing resin layer (4) will decrease. It is preferable that the surface resistance ratio of the layers is 104 to 1015.

The conductive layer (B) is formed of a thin metal film, and as the thickness becomes thinner, the surface resistance number becomes larger than 10, and as it becomes thicker, the surface resistance number becomes smaller than α1Ω, so it should be 400 to 50.
00 angstroms, preferably 500 to 3000 angstroms, more preferably 600 to 2000 angstroms. Examples of the metal include aluminum, silver, gold, copper, zinc, tin, nickel, and molybdenum, with aluminum being preferably used.

Any method may be used to form the conductive layer (B), such as a vacuum evaporation method, an ion blating method, and the like. Note that if there are minute defects or pinholes in the metal thin film, the current will concentrate in those areas when electricity is applied, making it easy to cause discharge damage.

It is preferable to form a conductive layer (ball) by laminating two or more metal thin films by the above method.

Thermal transfer layer (C
) is a layer that is not completely cured and is made of a thermosetting resin and a curing agent, and is transferred to the lithographic printing plate by the heat generated in the conductive layer (B) during electrical plate making. and
Laminated on the conductive layer (B).

The above-mentioned thermosetting resins include (drying oils such as linseed oil and tung oil, which can be molded into sheets or films even if not completely cured and are components of printing ink after thermosetting, and high-boiling petroleum oils) It is preferable to use materials that do not substantially melt or swell in system solvents, such as phenol resins, area resins, epoxy resins, phletane resins, polyester resins, and the like.

The above-mentioned curing agent may be one that is generally used as a curing agent for the thermosetting resin used. For example, hexamethylenetetramine, para-toluene sulfonic acid, etc. are used for phenolic resins, and amines are used for epoxy resins. ,
For example, acid anhydrides, amides, etc., and isocyanates, polyols, amines, organic tin compounds, etc. for phletane resins. The amount of the curing agent to be added may be appropriately determined depending on the type of thermosetting resin and curing agent, and should be determined so that the transferred thermosetting resin is completely cured by the heat during electric plate making. preferable.

The thickness of the layer is preferably 5 to 20 μm, and preferably 1 second, since the thicker the layer is, the more thermal transfer will occur.
~10μ.

The above heat-sensitive transfer layer (Q is brought into contact with the lithographic printing plate material during electrical plate making, and is conductive by electricity applied from the metal-containing resin layer diagram example! (B) is melted by the heat generated in lithographic printing. The transferred thermosetting resin is thermally transferred to the printing plate material, and the transferred thermosetting resin is thermosetted to produce the plate material for lithographic printing. Therefore, the K1 thermal transfer r is used so that the plate material can be visually observed.
A coloring agent may be added to im (C). The coloring agent is preferably one that will not be eluted by the cleaning solvent used to wash the printing ink or plate material. In this case, the g, s+ transfer layer (C1 may be colored on the surface of the plate when it comes into contact with the lithographic printing plate material, or the i8 thermal transfer layer (for the thermosetting resin plate material transferred to the plate material of Q) may be colored. I8 to prevent the adhesive strength from decreasing.
Thermal transfer 11 (C3) is preferably formed into two layers and a coloring agent is added to the conductive layer (Bl side).

As mentioned above, the electrically conductive thermal transfer plate-making material consists of a metal-containing resin layer side, a conductive layer (4), and a thermal transfer layer (C), which are laminated in this order. The materials are laminated so that the thermal transfer 1! (C) is in contact with the plate surface of the lithographic printing plate material, and electricity is applied from the metal-containing resin sheet to generate heat in the conductive layer (B), and the heat transfers the sensitivity. The thermal transfer layer (C) is thermally transferred to the plate surface of a planographic printing plate material, and the transferred thermosetting resin is cured to form an image, thereby obtaining a plate-made planographic printing plate material.

The voltage for the above-mentioned energization is generally 5 to 300V, but since a high voltage lowers the accuracy of the image, it is preferably 100V or less, and more preferably 10 to 50V. Further, for electrical plate making, conventionally known discharge recording machines, plate making machines, etc. can be used.

Further, any lithographic printing plate material can be used, such as a polished aluminum plate, an electrophotographic mask, and the like. The lithographic printing plate material must be wood-philic except for the part where the #-i image will be formed during lithographic printing, but the lithographic printing plate material must be treated to be hydrophilic before plate making, and then Electric plate making may be performed, or after electric plate making, the image portion may be removed and subjected to hydrophilic treatment.

In addition, the thermosetting resin transferred to the lithographic printing plate material is cured by the heat generated during discharge breakdown, but in order to achieve more complete curing, the lithographic printing plate material that has been made into a plate may be further heated. good.

〔Effect of the invention〕

The structure of the present invention is as described above, and when a lithographic printing plate material containing an electrically conductive thermal transfer plate-making material is laminated and electricity is applied from the metal-containing resin layer side, heat is generated in the conductive layer, and the heat transfer layer is transferred to the thermal transfer layer. At the same time, the thermally transferred thermosetting resin is completely cured, and an image is formed on the plate surface of the lithographic printing plate material. At this time, since it can be performed at a voltage lower than 100 V for energized plate making, the number of recording needles can be increased, the plate making speed can be increased, and safety is improved.

In addition, the metal-containing #I grease layer will not be destroyed or change in any way even during electrical plate making, and since electrical plate making is performed at a low voltage, less soot and carbon black will be generated during electrical plate making, and scattering will be suppressed. This prevents soot and carbon black from adhering to the recording stylus, reducing the troublesome maintenance of the recording stylus. Therefore, since soot and carbon black do not adhere to the recording needle, it is possible to obtain a highly reliable and clear plate-making image.

Therefore, there is no need for a photographic process, exposure process, or cleaning process, and plate making can be performed directly using a facsimile machine, a convenience store terminal, or the like.

〔Example〕

An embodiment of the present invention will be described. Hereinafter referred to as single K “part”
"parts by weight" means "parts by weight".

Example 1 Thermoplastic polyurethane resin (manufactured by Nippon Polyurethane Co., Ltd., trade name Niraporan 5109, 30% urethane, 70% dimethylformamide) 100 parts Electrolytic copper powder (average particle size L 5μ) 70 parts Methyl ethyl ketone 100 parts A blend consisting of the above composition Dissolve and disperse, cast onto a glass plate, dry,
A metal-containing resin sheet with a thickness of 15 μm was obtained. The electrolytic copper powder was 23.8% by volume in the sheet. Further, the surface resistance of the sheet was αextollΩ.

A composite sheet was obtained by vacuum-depositing aluminum twice under the conditions of K 3 × 1 G4 Torr to form a conductive layer having a thickness of 900 angstroms. The surface resistance of the conductive layer was Q, 2Ω.

Thermosetting polyurethane resin (manufactured by Nippon Polyurethane Co., Ltd., trade name Nilaboran 2304, 35% urethane, 65% methyl ethyl ketone) 100 parts Curing agent (manufactured by Nippon Polyurethane Co., Ltd., trade name Coronate L)
5 parts methyl ethyl ketone 100 parts Next, a mixture having the above composition was allowed to dissolve, and was coated on the above conductive layer and dried to a thickness of 3
A heat-sensitive transfer layer having a thickness of 18 μm and not completely cured was formed to obtain an electrically conductive heat-sensitive transfer plate-making material having a thickness of 18 μm.

The obtained plate-making material was brought into contact with a mimeograph paper-making machine (manufactured by Gestelatner, trade name: Guest Fax l mesh graining), a recording needle was brought into contact with the metal-containing resin sheet, and a direct current of 3
Apply 0V electricity, scan line density 12//am, recording speed 12m/s! When electrical plate making was carried out under the conditions of le, there was no scattering of soot or copper powder, there was almost no bad odor, and a lithographic printing plate material could be made without producing any through holes in the metal-containing resin sheet. Note that the transferred thermosetting resin was completely cured.

The obtained plate material was supplied to an offset printing machine (manufactured by Su'pi Co., Ltd., trade name: Offset Printing Machine 480) and printed on high-quality paper using printing ink (manufactured by Dainippon Ink Chemical Co., Ltd., trade name: New Apex GI). After printing 3000 sheets, clear printed matter was obtained.

Example 2 100 parts of thermosetting polyflex resin (manufactured by Nippon Polyurethane Co., Ltd., trade name Nilaboran N-2304, 35% Frethane, 65% methyl ethyl ketone) Curing agent (manufactured by Nippon Polyurethane Co., Ltd., trade name Coronate L)
5-part metal dye (manufactured by Hodogaya Chemical Co., Ltd., trade name Spiron Black BNH)
5 parts methyl ethyl ketone Z
The oo part is then dissolved and dispersed with a formulation having the above composition,
It was coated on the conductive layer of the composite sheet obtained in Example 1 using a gravure coater and dried to form a heat-sensitive transfer layer with a thickness of 4 μm, thereby obtaining an electrically conductive heat-sensitive transfer plate-making material with a thickness of 19 μm.

When plate making was carried out using the obtained plate making material in the same manner as in Example 1, there was no scattering of soot or copper powder, almost no bad odor, and no through holes were formed in the metal-containing resin sheet. I was able to print the material. Note that the transferred thermosetting resin was completely cured.

3 in the same manner as in Example 1 using the obtained plate material.
After printing 000 sheets, clear printed matter was obtained.

Claims (1)

[Claims] 1. (A) Consisting of a metal powder and a resin matrix, the metal powder accounts for 5 to 60% by volume and the surface resistance is 10^
(B) A metal-containing resin layer that is made of a metal thin film and has a surface resistance of 0.1 to 1 Ω and is not destroyed by electrical discharge during electrical plate making. A conductive layer and (C) an electrically conductive thermal transfer plate-making material consisting of a thermosetting resin and a curing agent, a thermal transfer layer that is not completely cured, and laminated in the above order, are combined with the thermal transfer layer (C). The heat-sensitive transfer layer (C) is laminated so that C) is in contact with the plate surface of the planographic printing plate material, and the heat generated by applying electricity from the metal-containing resin layer (A) side is used to transfer the heat-sensitive transfer layer (C).
1. A method for producing a plate material for lithographic printing, which comprises transferring the image onto a plate surface and curing the transferred thermosetting resin to form an image.