JPS61160749A - Production of photosensitive resin gravure plate material - Google Patents

Abstract

PURPOSE:To obviate the generation of an adverse influence such as stain by ink by winding a plate-shaped photosensitive resin plate material on a cylinder base material and packing a material ink repulsiveness into the clearances generated at both ends of the plate material. CONSTITUTION:A general practice to wind the photosensitive resin plate material on the cylinder base material consists in coating an adhesive agent on the cylinder base material or plate material and pasting the cylinder base material and the photosensitive resin plate material. The clearances generated when the plate-shaped plate material is wound on the base material are preferably made as small as possible but the staining by the ink can be prevented without any particular problem if the clearances are <=5mm. The material having ink repulsiveness to be packed into clearances generated at the juncture is more specifically exemplified by silicone and fluororesin. Crosslinked silicone rubber are more preferably used as the silicone. The crosslinkable silicone rubber is cured by heating or irradiation of active rays after packing when said rubber is packed into the clearances.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the production of substantially seamless printing plates. More specifically, a plate-shaped photosensitive resin plate material is used, and the printed matter has seams.

(Prior technology) Plate materials for gravure printing are made by plating copper on an iron cylinder, applying photosensitive liquid directly or indirectly with carbon terash, etching with iron chloride liquid, etc., and then applying chromium. There is a known method of finishing by plating, such as. There is also a method of engraving directly on the copper surface with a diamond needle, etc. However, both methods are not applicable.

The plate-making process is complicated, productivity is low, and plating is required, so waste liquid treatment from the plating bath is necessary. In the case of the etching method, there are problems such as the need to treat waste liquid from the etching bath.

On the other hand, methods for obtaining gravure printing plates using photosensitive resins are also known. A method has been proposed in which resin is poured in liquid form in a manner similar to casting. However, these methods require special equipment and are very expensive, so they are hardly ever put into practical use.

[Problem that the invention seeks to solve]

One possible method for forming a gravure plate material using a photosensitive resin is to wrap a plate-shaped photosensitive resin plate material around a cylinder, but in this case, processing of seams becomes a problem. In other words, there is the problem that the doctor blade gets caught in the gap that occurs between both ends of a plate-shaped photosensitive resin plate material wound around it.

There is a problem that ink that enters the gaps may be transferred to printed matter and cause stains. Regarding the doctor blade getting caught,
It is effective to make the seam at an angle other than perpendicular to the direction of rotation of the gravure cylinder so that it is not parallel to the doctor blade.

Regarding the problem of ink entering the seams, no effective method has been found other than using offset gravure and cutting out the portions of the blanket that correspond to the seams to prevent ink from being transferred to the printing material. However, this method has problems such as the printing machine being complicated and the blanket also having to be replaced when changing the pattern.

The inventors of the present invention have conducted extensive research into ways to prevent ink stains caused by ink that has entered the seams.

We have arrived at the present invention.

[Means for solving problems]

The present invention provides a gravure plate material that uses a plate-shaped photosensitive resin plate material and does not cause stains due to seams.

That is, substantially seamless printing characterized by wrapping a plate-shaped photosensitive resin plate material around a cylinder base material and filling the gap between both ends of the plate material with an ink-repellent substance. The present invention relates to a method for manufacturing a printing plate.

Below, nine aspects of the present invention will be explained in more detail.

The cylinder base material used in the present invention is as follows.

Metal cylinders such as iron, copper, and aluminum are the most common. However, a plastic cylinder or a metal cylinder whose surface is wrapped with plastic or rubber can also be used. Furthermore, an endless belt made of metal or plastic can also be used as the base material.

As the photosensitive resin plate material to be wrapped around the above-mentioned base material, all known ones can be used.

Celluloses such as vinyl and cellulose acetate.

Plate material whose photosensitive layer is a photosensitive resin made by blending a photopolymerizable unsaturated compound with a polymer selected from the group consisting of saturated polyesters, and whose photosensitive layer is a photosensitive resin whose main component is unsaturated polyester or unsaturated polyurethane. This includes plate materials, etc. These photosensitive resin plates are generally lined with a metal plate such as steel or aluminum, or a plastic film such as polyethylene terephthalate. However, in the present invention, such an unlined photosensitive resin sheet can also be used.

In order to wrap the above-mentioned photosensitive resin plate material around a cylinder base material, it is common to apply an adhesive on the cylinder base material or to the plate material to bond the cylinder base material and the photosensitive resin plate material. . Also, double-sided adhesive tape can be used instead of adhesive.

If the photosensitive resin plate material is lined with a steel plate, it is also possible to wrap it around it using the magnetic force of a magnetized cylinder (magnet cylinder). It is also effective to apply a carping process to the lined plate material to deform the plate material itself into a shape close to the cylinder shape before mounting the plate material in the cylinder.

It is desirable to minimize the gap that occurs when a plate material is wrapped around a base material.

If the method of the present invention is used, stains caused by ink can be prevented without any particular problem as long as the gap is 5 mm or less.

All known ink-repellent substances can be used to fill the gaps that occur in the seams of the present invention, and specific examples include silicone and fluorine-containing resins. As silicone.

Organopolysiloxane, which is a so-called silicone rubber, is common, but in order to obtain resistance to the organic solvents contained in gravure ink, organopolysiloxane is heated or mixed with moisture in the air, organic metals, inorganic salts, amines, etc. More preferably used is a crosslinked silicone rubber that has been crosslinked by coercion or that has been crosslinked by introducing unsaturated bonds into organopolysiloxane and thermally or photopolymerizing it.

As the fluororesin, a polymer of a fluorine-containing vinyl monomer having a perfluoroalkyl group, or a copolymer of an acrylate or methacrylate and a fluorine-containing vinyl monomer is preferably used.

There are no particular limitations on the method of filling the above-mentioned ink-repellent substance into the gap created between the edges by wrapping the plate material around the base material. The easiest method is to dissolve the ink-repellent material in a suitable solvent, fill it into the gap using a microsyringe, and then volatilize and remove the solvent. Of course, filling without solvent is also possible if the viscosity of the filler is low or if it is heated and filled in a molten state.

It is also effective to apply adhesive to the gaps in advance. In the case of silicone, coupling agents such as aminosilane as adhesives.

Epoxy adhesive is preferably used for the fluororesin.

When filled with crosslinkable silicone rubber, it is cured by heating or irradiation with actinic rays after filling. Also,
If it is filled in a molten state, it must be cooled and solidified.

It is also possible to wrap the plate material unexposed around a base material such as a cylinder, fill the seams with an ink-repellent material, and then expose and develop the plate material on the cylinder base material. but,
After exposing and developing the plate-like plate material to obtain a printing plate,
Wrap this around the base material.

It is preferable to fill the joint with an ink-repellent material after that because the work is simpler.

In the present invention, the gap created between both ends of the plate material is filled with an ink-repellent material, so that even if ink adheres to this area, it is repelled. Therefore, despite the presence of seams, the printed matter is characterized in that no adverse effects such as ink stains occur.

〔Example〕

The invention will be explained in further detail in the following examples.

Example 1 As a plate-shaped photosensitive resin plate material, a 30 μm thick photosensitive layer containing alcohol-soluble polyamide, a photopolymerizable unsaturated compound, and a photosensitizer was provided on a 400 μm thick polyethylene terephthalate substrate. I chose the printing material.

A positive film with a predetermined pattern was vacuum-adhered to the photosensitive layer of this plate material, and exposed for 3 minutes with a chemical lamp.Next, a developer solution of ethanol/water - 80/20 (weight ratio) was added for brush washing. Developing was carried out in a machine for 20 seconds to obtain a printing plate having concave portions with a predetermined pattern.

This printing plate was attached to a steel cylinder with a diameter of 254 mm using double-sided adhesive tape. The gap between the plates was about two cabinets wide. Note that this gap is 1
The opening was set at an angle of 5°.

Next, crosslinking was carried out using water from 1, which is a liquid room temperature crosslinkable silicone rubber.

The plate material obtained as described above was set in a gravure printing machine and a printing test was conducted. As a result, smooth printing was possible without the doctor blade getting into the seams. It was also confirmed that the ink repellency of the cross-linked silicone rubber filled in the seams prevented ink from entering the seams, and that no ink stains were caused by the seams on printed matter.

Example 2 As a plate-like photosensitive resin plate material, a 100 μm thick photosensitive resin layer consisting of 9-partly saponified polyvinyl acetate, a photopolymerizable vinyl monomer, and a photosensitizer was provided on a 200 μm thick steel substrate. I chose something.

A positive film with a predetermined pattern was vacuum-adhered to this plate material, and exposed for 1 minute using an ultra-high pressure mercury lamp.

Next, the plate was developed for 1 minute using a spray washing machine containing neutral water to obtain a printing plate having concave portions corresponding to the image.

This printing plate was attached to a magnetic cylinder having a diameter of 581 mm. The gap between the edges of the printing plate is 3 circles.

The gap was set at an angle of 10'' with the doctor blade.As a filling material, 20 parts by weight of photopolymerizable silicone obtained by reacting acryloxypropyltrichlorosilane and dihydroxydimethyl silicone was mixed with 80 parts of toluene. A solution was prepared by dissolving 1 part by weight of benzoin ethyl ether as a photoinitiator and adding 1 part by weight of benzoin ethyl ether as a photoinitiator.This solution was filled into the gap with a microsyringe.
It was dried at 80°C for 10 minutes. Next, this joint portion was exposed to light for 2 minutes using an ultra-high pressure mercury lamp to photocure the filling material.

The cylinder plate material with seams treated in this manner was set in a gravure printing machine and a printing test was conducted. As a result, it was confirmed that the ink repellency of the photocured silicone prevents ink from entering the seams, so problems such as stains do not occur on printed materials.

Example 3 A photosensitive resin plate material was selected in which a 200 .mu. thick aluminum sheet was provided with an 800 .mu. thick photosensitive layer made of polyetheramide, a photopolymerizable vinyl monomer, and a photosensitizer. This plate material was made in the same manner as in Example 1 to obtain a plate-shaped intaglio material.

This printing plate was coated with adhesive and had a diameter of 508 mm.
Mounted on the mini cylinder. The gap between both ends of the plate material is approximately 4rm wide and 1. Ivy. Further, this gap was set at an angle so that it had an angle of 20° with respect to the doctor blade.

A polymer obtained by polymerizing monomers having perfluoroalkyl groups as shown below was selected as a filler.

This polymer was brought into a molten state, filled into the above-mentioned gap using a gear pump and a nozzle, and then cooled and solidified.

When we conducted a printing test on the cylinder plate material obtained in the above manner using a gravure printing machine, we found that the ink repellency of the fluorine-containing resin filled in the seams was sufficient.

No ink entered the seams at all. Therefore, no adverse effects due to the seams were observed in the printed matter.

〔Effect of the invention〕

Wrapping a plate-shaped photosensitive resin plate material around a cylinder to produce a cylindrical plate material and applying this to gravure printing is expected to have a significant effect on streamlining the plate making of gravure plate materials. but,
The biggest problem in this case is that ink enters the seam between both ends of the plate-like plate material, and this ink is transferred to the printed material, causing stains.

In the present invention, it has been discovered that this problem can be solved by filling this joint with an ink-repellent substance such as silicone or fluorine-containing resin.

If such treatment is not carried out, ink will enter the seam in the ink pan, and the ink that has entered the seam will not be scraped off by the doctor blade and will be transferred to the printed matter, causing staining problems.

However, if the ink-repellent material of the present invention is filled in the seam, ink can be prevented from adhering to the seam, and the problem of staining will not occur.

As described above, the present invention proposes a highly streamlined manufacturing method for photosensitive resin gravure plate materials.

Claims (3)

[Claims] (1) Photosensitivity that reduces the effect of seams by wrapping a plate-shaped photosensitive resin plate material around a cylinder base material and filling the gap between both ends of the plate material with an ink-repellent substance. Manufacturing method of gravure plate material. (2) The method for producing a photosensitive gravure plate material according to claim 1, wherein the ink-repellent substance is silicone. (3) The method for producing a photosensitive gravure plate material according to claim 1, wherein the ink-repellent substance is a fluororesin.