JPS5891452A - Lithographic plate - Google Patents

Abstract

PURPOSE:To obtain a lithographic plate superior in adhesion to a printing base plate made of metal or the like, high in printing resistance, and capable of direct printing, by using an olefinic polymer having carbonyl groups as an elastic polymer material. CONSTITUTION:An image line part made of an olefinic polymer having carbonyl groups is formed on the water-holding surface of a base. As said base, a zinc plate cronak treated, an aluminum plate brunak treated, the surfce of plastic plate vapor deposited or nonelectrolytically plated with aluminum or zinc, or coated with a hydrophilic polymeric compd., etc. are used. As a method for patterning the image lines, a method for converting this resin into a toner, patterning it by electrophotography, and transferring it, a method for patternwise applying pressure, heat, or the like, and transferring it, an ink jet method, etc. are used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has high rigidity and provides excellent printing quality.
Furthermore, the present invention relates to a lithographic printing plate suitable for direct shaving printing.

A currently widely used lithographic printing plate is the Presen V-sized plate (hereinafter referred to as "18th plate"). The P8 plate is formed by coating a photosensitive resin layer on the surface of a substrate.The photosensitive resin layer is cured or solubilized in a pattern by light, and only the soluble portion of the photosensitive resin layer is dissolved and removed by development. A lithographic printing plate is produced by forming a non-image area consisting of the extended surface of the water-retaining substrate and an image area consisting of the remaining resin area. It takes 2
In the 8th edition, the light was allowed to penetrate deep into the photosensitive resin layer.
In order to minimize resolution deterioration due to light scattering inside the photosensitive resin layer and to facilitate penetration of the developer during visual imaging, the film thickness of the photosensitive resin layer of the PS plate should be made as thin as possible. It is necessary to make it thin, and as a result, the resin in the printing area of the current 18th plate is extremely thin.

Furthermore, in order to ensure sufficient solubility during development, Fi
The molecular weight of the photosensitive resin constituting the photosensitive resin layer of the PS plate must be suppressed to a relatively low value.

For the above reasons, the thickness of the resin in the printed area of the 18th plate is extremely thin and contains low molecular weight dispersion, and as a result, the printed area of the P8 plate has the drawback of being easily abraded due to the printing process. be.

In particular, when high printing durability and strength are desired, the resin in the image area is enamelized by heat treatment, but when this treatment is performed, the ink receptivity in the image area decreases and printing Meltdown occurs, resulting in a decrease in quality.

Also, as mentioned in ViMij on the P8 edition, it is necessary to use a hard resin such as novolak in order to obtain a certain level of printing durability with relatively low-molecular-weight materials, and it is necessary to use a hard resin such as novolak to blank the ink on the - line area. In a printing method that transfers images directly onto a piece of paper through a foot (hereinafter referred to as "direct printing"), hard line areas do not blend well with the paper, and strong printing pressure must be applied, resulting in damage to the image area. There is a problem in that the resin wears out quickly.

As described above, the currently widely used 18th plate has problems in terms of printing durability, printing quality, and suitability for direct printing. In order to solve this problem, the present inventor conducted intensive research and found that by using an elastic polymer material as the printing area material, the printing durability can be improved in normal offset printing.
We discovered that it has excellent printing quality and that it is possible to obtain flattened printing quality even in direct printing, and as a result of further research, we developed an olefinic polymer resin with carbonyl groups as the elastic polymer material. By using this method, we have completed a lithographic printing plate that has high printing durability and has variable adhesion to printing substrates such as metals.

That is, the present invention relates to a lithographic printing plate characterized in that the printing surface is a water-retaining substrate and an image area of an olefinic polymer resin containing a carbonyl group is provided on the water-retaining surface of the substrate.

The present invention will not be described in detail below, but will be explained by using a substrate with a water-retentive surface.It is desirable that the substrate has mechanical strength as a printing plate. Examples of specific materials include iron, aluminum, copper, zinc and other metal maples, various alloys, and inorganic materials such as glass; wood, leather, thermal rubber, paper, and cloth; hydrocarbon thread plastics such as polyethylene and polystyrene. Polar vinyl plastics such as AB8 resin, linear structure plastics such as plastics and polyamides, formaldehyde plastics such as phenolic resins, cross-linked plastics such as plastics and unsaturated polyesters, paper towels, 7'-lulose acetate, etc. Polymer materials such as cellulose plastics and materials commonly called rubber can also be used, and composites of one or more materials can also be used, and in history, materials that have water-retentive properties have been used.

When using zinc l/λ as a method for improving water retention, the zinc plate is immersed in a solution (called Kronak solution) consisting of ammonia dichromate,* and sulfuric acid, and then washed with water.

The Cronac process forms a water-retentive film on the surface of zinc by immersing it in a solution (called a pre-etching solution) consisting of gum arabic, water, l-chromium ammonium, and phosphoric acid, and rinsing with water. A liquid consisting of hydrohydric acid, ammonia dichromate, and water (called Brunac's solution)
After immersing the aluminum in water and washing it with water, the Prunaku treatment forms a water-retentive film on the aluminum surface by immersing it in the above-mentioned Plenite solution and washing with water.For zinc and aluminum, well-known dry etching and chlorination are also used. be able to.

Also, for plasti, pure aluminum.

Aluminum alloy containing any one of copper, zinc, iron, magnesium, etc. as a component, zinc, chromium, etc., to a thickness of 0.1 to 20μ by means such as vacuum deposition, sputtering, taring, or electroless plating. A method of applying plasti on the surface of plastic, a method of modifying the surface of plastic to retain water by corona treatment or plasma polymerization, and hydrophilicity.
The molecular compound is made to a thickness of 0.01 to 20 μm by an appropriate method.
In addition to the method of applying water-retaining gold foil to aluminum or the like with a thickness of 3 to 20 μm, other methods can also be used.

In addition, examples of the water-retentive polymer compound include, for example, ``Hydrophilic Polymer 1, supervised by Yoshio Nakamura'' (Kagaku Kogyo Co., Ltd.).

1973, Tokyo) 1% L, Davidsorll
Edited by M, 8ittngIWater-8o1ubl
e Re5ins J (Van No5trand
) Rainhold, 1968, New Year
k) and the polymerized ornaments described in Japanese Patent Publication No. 35-5093 can be used, specific examples of which include cellulose-bound conductors, e-ha/methyl cellulose, ethyl cellulose, carpoquin-methyl cellulose. ,
Carpoquinlethylcellulose, ethylhydroxyethylcellulose, ethylmethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, etc., polyvinyl alcohol,
S public esters, partial ethers and partial acetals of polyvinyl alcohol containing unsubstituted vinyl alcohol units in the proportion necessary for hydrophilicity; polyvinylpyrrolidone, polyvinyl methyl ether, vinyl methyl ether maleic anhydride copolymers Combined, styrene/anhydrous maleic copolymer, vinyl acetate/anhydrous maleic enemy soldier J18
Examples include 88-99-hydrolyzed polyvinyl acetate, polyacrylamide, gelatin, modified gelatin, gum arabic, and mixtures of two or more of the above substances.

The olefin-based polymer resin containing a carbonyl group used in the present invention is described above regarding the olefin-based polymer resin containing a carbonyl group that constitutes the l#1IillA portion provided on the water-retentive surface having a water-retentive surface. Polymer resins include polyolefin resins that have been cured and have carboxyl groups introduced. Examples of product names include 1 Nippon Petrochemical Co., Ltd. N Polymer, Tonen CMP manufactured by Tonen Petrochemical Co., Ltd.
HA series, MODIC manufactured by Sanshin Yuka ■, Seiksen manufactured by Seitetsu Kagaku Kogyo ■, Ronpla manufactured by Mitsui Toatsu Chemical ■4. Adma manufactured by Mitsui Petrochemical Industries, etc.; Copolymer of ethylene and acrylic acid, product names include Dow EA manufactured by Dow Chemical Company
A copolymer: A copolymer of ethylene and acrylic acid or methacrylic acid, or a cross-linked product of ethylene, so-called IO, and ZUMMER 1.Product names include Su-Rin manufactured by Dehyobon Co., Ltd. in the United States, and Himilan manufactured by Mitsui Polychemical Co., Ltd. , Asahi Dow■
Corporene latex, etc. manufactured by Toyo Soda Industries, Ltd., Sumitate manufactured by Sumitomo Chemical, Yucalon Eva manufactured by Mitsubishi Yuka, Evafre manufactured by Mitsui Polychemicals, etc.
Ethylene and #
Partially saponified copolymers with vinyl esters, fpA product names such as Demiran manufactured by Takeda Pharmaceutical Co., Ltd. Copolymers of ethylene and acrylic acid esters, product names such as DPD-6169 manufactured by Nippon Unicar; etc. carbonyl group,
Examples include olefin resins having carboxyl carbonyl groups.

In order to form the taX portion of the carbonyl group-containing olefin polymer resin in a pattern on the water-retaining surface of a substrate having a water-retaining surface, the resin is made into fine particles, formed into a toner, and patterned on an electrophotographic photosensitive plate. A method of transferring and heat-fixing the resin to a printing plate substrate, dissolving the resin in a solvent, placing a sheet of paper or a film of polypropylene, polyester, etc. with a heavy cloth and dry Ml on the printing plate substrate, and applying pressure. , a method of transferring by applying heat etc. in a pattern, or a method of transferring the resin t.
Any method may be used, such as dissolving it in a solvent, spraying it onto a printing plate substrate in a pattern from an inkjet nozzle, drying it, and fixing it by heating. The thickness of the image area formed as described above may be 1 to 20 μm so as to exhibit the elasticity of one image area.

The lithographic printing plate obtained by pressing as described above has l! There is no need to cure or solubilize the line area resin with light, and there is no need to consider developer permeability, so there is no need to reduce the thickness of the image area resin, and high printing durability f4 can be achieved. It has the advantage of being possible.

Furthermore, when an olefinic polymer resin containing a carbonyl group is used in the N line part of the lithographic printing plate of the present invention, it has appropriate elasticity, and moreover, the conventional PS plate has a line part made of a hard and brittle material with a low molecular weight can. It has the great advantage of superior printing durability compared to .

Furthermore, the above II! The elasticity in the II line area plays an effective role in lithographic direct printing, where the first plate and paper are brought into direct contact and pressure is applied to transfer the ink on the image area to the paper. That is, when the lithographic printing plate of the present invention is used for direct lithographic printing, the elasticity of the line absorbs minute irregularities formed by white paper and fibers on the paper surface, helping the ink to blend well with the paper surface. be. This can be considered to be a state in which the paperback image holder also serves as a plunket in offset printing. As a result, direct printing using the lithographic printing plate of the present invention has the great advantage of being able to reproduce smooth tones similar to ordinary offset printing. When used for
For the above reasons, the printing area and the paper come into close contact with each other, so it is possible to lower the printing pressure compared to when using a conventional PS plate, and as a result, the printing durability in direct printing is longer than that of a conventional PS plate. This has the advantage that the printing press is greatly improved and the load on the printing machine is also reduced.

Furthermore, in the lithographic printing plate of the present invention, the carbonyl group-containing olefinic polymer resin used as the image resin has excellent adhesion to metals, etc., so there is no need to use a primer, etc., and production is easy. In addition to this advantage, there is no peeling of the image area and excellent printing durability.

The present invention will be further explained below using examples.

Example 1 Partially desiccated EVA (ethylene-vinyl acetate copolymer) in powder form (manufactured by Narita Pharmaceutical Co., Ltd.; Dumilan C-22)
70) as a toner to form an electrostatic latent image on zinc oxide offset master paper (manufactured by Iwasaki Tsushinki ■; MRI)
A toner image was formed thereon by magnetic brush development. The surface of the toner image on the master paper was placed on a 0.3mm thick aluminum plate whose surface was grained by ball polishing.
After irradiating strong light from the back side of the master paper to discharge the electrostatic latent image, the back side was positively charged with corona and the toner image was transferred onto an aluminum plate.

Next, this aluminum plate was heated at 100°C for 30 minutes.

A lithographic printing plate having a partially saponified EVA image area was obtained by fixing the toner.

This lithographic printing plate was attached to an offset printing machine (manufactured by Man Corporation: Ultraman GS) and printed on high-quality paper at a rate of 10,000 sheets per hour, but even after printing 350,000 sheets, the image area did not come off and the print quality began to deteriorate. There was no difference.

Example 2 A lithographic printing plate was prepared in the same manner as in Example 1, except that powdered puiono-4-resin (Niheimiran 1702, manufactured by Mikata Polychemical Co., Ltd.) was used.

This lithographic printing plate was directly printed on an offset rotary press (manufactured by Mitsubishi Heavy Industries, Ltd.: A horizontal offset press) by changing the paper path.
! A printed book with a smooth print quality similar to that of ordinary offset printing was obtained without removing the lIs portion.

Example 3 Partially saponified gVA (manufactured by Narita Pharmaceutical Co., Ltd.: Dumilan C-2270) and carbon bra, resin (manufactured by Mitsubishi Chemical Corporation: Carbon-Dyana 30°) were placed 5 times over partially saponified EVA in toluene at 80°C. part), dissolve and disperse,
The mixture, which had been cooled to room temperature, was coated onto a polyester film having a thickness of 25 μm in a dry coating amount of 10 μl.

The coated surface of this film was grained by ball polishing and overlapped with an aluminum plate with a thickness of 90.3 Ill, and the infrared edge YA
A G laser (wavelength: 1.06 μm, average output: 400 W) was scanned while modulating it in a pattern, and the coating film was thermally transferred to an aluminum plate, thereby creating a lithographic printing plate with the transferred wall film as the graphic area.

Offset printing was performed using this lithographic printing plate in the same manner as in Example 1, and the results were also the same.

Claims (1)

[Claims] 1. A lithographic printing plate comprising a substrate having a water-retaining surface, and an image area of an olefin polymer resin containing a carbonyl group provided on the water-retaining surface of the substrate.