JP2001105562A - Method of making plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plat-making process dispensing with procedural steps such as plating, grind stone polishing, mirror finishing by buffing, coating/ forming of a photosensitive film, developing, etching and resist peeling by performing laser abrasion and chromium plating for the coating film. SOLUTION: A chromium plating is removed from a used printing roll and a coating film consisting of a laser abrasion material is removed by grind stone polishing to obtain a printing roll base material to be used repeatedly as a base material to be used for plate-making. In addition, the coating film for forming a printing plate is formed on the surface of the base material using the laser abrasion material which can be laser-abraded and chromium-plated so that the coating film is of a specified thickness such as not allowing the exposure of the base material to be used for plate-making when the coating film is laser-abraded. After that, a part corresponding to the image line part is irradiated with laser beams and the coating film part of the laser-emitted part is laser-abraded to form an intaglio or a relief-printing plate. Finally the printing plate is chromium-plated so that plate wear is imparted to the plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plating step, a grinding stone polishing step, a mirror polishing step by buffing, a coating and forming step of a photosensitive film, a developing step, by forming a film and performing laser ablation and chromium plating. The present invention relates to a plate making method for obtaining an intaglio or letterpress in which an etching step and a resist stripping step are unnecessary.

[0002]

2. Description of the Related Art A gravure plate making method by a conventional etching method, which is a ballad plating type gravure plate making method, is manufactured by, for example, the following steps 1) to 13). 1) Ballad plating is cut and removed by hand using wrench and pliers. 2) Measure the diameter of three to five points from one end to the other end of the printing roll, and eliminate the roll with low roundness accuracy and the roll with low cylindrical accuracy. 3) After performing the releasable surface treatment, ballad plating is performed so that the film thickness is about 60 to 80 μm. 4) Polish the cylinder to remove the plating surface with a medium finishing whetstone # 800 to # 1200. 5) Polish with # 1500 to # 4000 top finish whetstone to minimize surface roughness. 6) Mirror polishing with buff. 7) Apply a negative transparent photosensitive film. 8) The non-image area is exposed and cured by an argon laser. 9) Remove the unexposed resist by alkali development to form an image area where copper plating is exposed. 10) Etch the exposed copper surface with dilute sulfuric acid to form cells. 11) Strip resist with strong alkaline solution. 12) Plate with chrome. 13) Deburr the chrome plating.

A gravure plate making method using a conventional etching method, which is a direct plate type gravure plate making method, is manufactured by, for example, the following steps 1) to 16). 1) The chromium plating is removed by etching with an aqueous solution of dilute sulfuric acid. 2) Measure the diameter of three to five points from one end to the other end of the printing roll, and eliminate the roll with low roundness accuracy and the roll with low cylindrical accuracy. 3) Perform corrective polishing to achieve precise cylindrical accuracy with a # 350 rough finish whetstone. 4) Using the same coarse finishing whetstone, perform plate drop polishing until the cells with the maximum depth are eliminated. 5) Polish the surface with a coarse finishing whetstone of # 500 and a rough finishing whetstone of # 800 in order to reduce the surface roughness. 6) Nickel plating so that the plating thickness is about 15 μm, and then copper plating so that the plating thickness is about 60 μm to 80 μm. 7) Polish the cylinder with a semi-finishing whetstone # 800 to # 1200 to remove the plating surface. 8) Polish the surface with # 1500 to # 4000 top finish whetstone to minimize surface roughness. 9) Mirror polishing with buff. 10) Apply a negative transparent photosensitive film. 11) The non-image area is exposed and hardened by an argon laser. 12) Remove the unexposed resist by alkali development to form an image area where copper plating is exposed. 13) Etch the exposed copper surface with dilute sulfuric acid to form cells. 14) Strip resist with strong alkaline solution. 15) Chrome plating. 16) Deburr chrome plating.

A gravure plate making method using a conventional electronic engraving machine is manufactured by, for example, the following steps 1) to 12). 1) The chromium plating is removed by etching with an aqueous solution of dilute sulfuric acid. 2) Measure the diameter of three to five points from one end to the other end of the printing roll, and eliminate the roll with low roundness accuracy and the roll with low cylindrical accuracy. 3) Perform corrective polishing to achieve precise cylindrical accuracy with a # 350 rough finish whetstone. 4) Using the same coarse finishing whetstone, perform plate drop polishing until the cells with the maximum depth are eliminated. 5) Polish the surface with a coarse finishing whetstone of # 500 and a rough finishing whetstone of # 800 in order to reduce the surface roughness. 6) Nickel plating so that the plating thickness is about 15 μm, and then copper plating so that the plating thickness is about 80 μm to 100 m. 7) Polish the cylinder with a semi-finishing whetstone # 800 to # 1200 to remove the plating surface. 8) Polish the surface with # 1500 to # 4000 top finish whetstone to minimize surface roughness. 9) Mirror polishing with buff. 10) Form cells with an electronic engraving machine. 11) Chrome plating. 12) Deburr chrome plating.

[0005]

Problems with the conventional gravure plate making method by the etching method are as follows. (1) Removal of copper plating (ballard plating or plate drop polishing) and copper plating for reuse are performed. Was uneconomical. (2) The number of grinding steps was large. (3) The grinding stone could not be satisfactorily polished, and pitch lines were formed. The pitch is defined as a spiral with a high and a low part formed like a screw thread, even though the surface roughness is uniform. This means that the long direction of the stripe appears as the roll surface length direction. (4) Mirror polishing was performed by buffing. (5) Photosensitive film coating-image printing-development-etching steps were performed. However, when the thickness of the photosensitive film was 2 .mu.m and 4 .mu.m, the photosensitive characteristics with respect to laser light differed greatly, leaving development residues or side etch. There was a sensitivity that it occurred greatly. In addition, there are problems with the conventional gravure plate making method using an electronic engraving machine: (1) copper plating for removal (plate drop polishing) and copper plating for re-use were performed, which was uneconomical. (2) The number of grinding steps was large. (3) The grinding stone could not be satisfactorily polished, and pitch lines were formed. (4) Mirror polishing was performed by buffing.

Here, as for the cylindrical polishing, there is a polish master (trade name, manufactured by Detoweiler GmbH, Germany) which is commercially available as an ultra-precision processing machine for the copper plating surface of a gravure cylinder. In this machine, the plate roll is chucked at both ends and rotated at a very low speed (1 to 10 r.p.
m), the diamond tool is rotated at a very high speed (3800 rpm), and the finish cutting of the diamond tool is moved at a very small speed (50-125 mm / min) to perform cylindrical cutting. According to this, the surface roughness is about 0.3 μm and sufficient accuracy can be obtained, but the waviness (pitch) is extremely large at about 1.5 μm. That is, when the plate is ground and corrected and polished by the polish master and then cylindrically processed uniformly from one end to the other end, a pitch is generated. Since the cylinder processed by the polished master has large undulation, pitch printing appears remarkably in printed matter in calendar printing consisting of highlights and halftone images, and it is not a very commercial product. Further, the surface roughness cannot be reduced. In the cylinder where the pitch is generated by the cylindrical processing by the polish master, the pitch remains even after copper plating. Also, even if buffing is performed on a cylinder processed by a polish master, the pitch cannot be eliminated. Therefore, the polish master has not been used for cylindrical machining of a cylinder that can be used for calendar printing consisting of highlight to halftone images.

The present invention has been devised in view of the above points, and forms a coating film and performs laser ablation and chromium plating to form a plating process, a grindstone polishing process, a mirror polishing process by buff polishing, and a coating of a photosensitive film. Forming process,
It is an object of the present invention to provide a plate making method for obtaining an intaglio or letterpress in which a developing step, an etching step, and a resist peeling step are unnecessary.

Further, the present invention provides a printing roll manufacturing company, which removes a chromium plating from a used printing roll, removes a coating made of a laser ablation material, and again forms a coating made of a laser ablation material. Can be shipped to a plate-making company or printing company.In the plate-making company or printing company, intaglio or letterpress printing is performed only by performing laser ablation and chrome plating with a yag laser device and chrome plating device installed. It is intended to provide an extremely simple plate making method that can be manufactured.

Further, according to the present invention, the diameter reduction of the roll diameter due to the roll polishing in one recycling plate making is extremely small, and the accumulated diameter reduction value of the roll diameter by the grinding stone polishing becomes large when the recycle plate making is performed more than ten times. Once, once every ten or more times, if copper plating is performed and the grindstone cylinder is polished and expanded to the initial roll diameter, it is sufficient for recycling.
It is an object of the present invention to provide a plate making method that eliminates the need to perform grinding cylinder grinding and mirror polishing by thick plating each time a plate is recycled as in the related art.

[0010]

According to a first aspect of the present invention, a surface of a plate-making base material is exposed when laser ablation is performed on a surface of a conductive plate-making base material with a laser ablation material capable of chrome plating. Form a coating for plate formation so as not to have the required film thickness, then irradiate the laser light to the portion corresponding to the image portion, ablate the coating portion there to form an intaglio or letterpress, It is an object of the present invention to provide a plate making method characterized by forming chromium plating for imparting printing durability.

[0011] The second invention of the present application is to provide a printing substrate roll to be reused by removing chromium plating of a used printing roll and then removing a film made of a laser ablation material. By using a laser ablation material capable of performing laser ablation, a plate-forming film is formed so as to have a required film thickness so that the surface of the plate-making base material is not exposed when laser ablation is performed. Providing a plate-making method characterized by irradiating a portion corresponding to a portion to ablate a coating portion thereof to form an intaglio or letterpress, and then forming chrome plating for imparting printing durability. It is.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The method of manufacturing a gravure plate of the present invention is manufactured by the following first to eighth steps. This step is a recycling step. For the first plate making, the first to third steps are omitted. Disposable versions are also omitted. First step: removal of chrome plating. Second step: Removal of a plate-forming coating by a solvent / a printing substrate roll which is a plate-making substrate to be repeatedly used. Third step: Diameter measurement and elimination of inaccurate rolls. Fourth step: a wettability surface treatment is performed. Fifth step: formation of a laser ablation film. Sixth step: formation of intaglio or letterpress by laser ablation. Seventh step: chrome plating Eighth step: sandpapering / deburring of chrome plating Each step will be described in detail below.

In the first step of removing the chromium plating, the used printing roll is etched with dilute sulfuric acid to remove the chromium plating. Laser ablation material cannot be removed. Take the used print roll from the printing company,
If the used printing roll is chucked at both ends, rotated and immersed in dilute sulfuric acid in a tank for several minutes, chromium plating can be removed. In addition, it applies to not only the roll plate but also the plan plate.

The step of removing the plate-forming film in the second step is as follows:
The laser ablation material is removed by grinding.
Laser ablation materials cannot be removed with solvents. #
With a PVA grindstone for finishing or precision finishing of 4000 to # 6000, it is enough to polish the laser ablation material and to completely expose the copper plating surface. Polishing of the copper plating surface is suppressed to less than 5 μm. Polishing method is, for example, # 60
The PVA grinding wheel of 00 prevents the extension of the rotation axis of the grinding wheel from intersecting with the rotation axis of the plate-making roll, and the rotation of the grinding wheel when viewing the extension of the rotation axis of the grinding wheel and the rotation axis of the plate-making roll from a plane direction. Since the extension line of the shaft is in a crossed state inclined at an angle smaller than a right angle with respect to the rotation axis of the plate making roll, about half of the chord line parallel to the diameter line which is off the center hole of the end face of the grinding wheel is used for the plate making roll. Make the plate making contact with the bus bar, increase the rotation speed of the plate making roll from the time of precision finishing polishing, press the grindstone against the plate making roll at the polishing pressure at the time of precision finishing polishing, and follow the grinding wheel with the rotation of the plate making roll. It is preferable that the grinding wheel is moved in the direction of the surface length of the plate making roll, or is performed by using a # 4000 PVA grinding wheel so that the extension of the rotation axis of the grinding wheel does not cross the rotation axis of the plate making roll and Whetstone When the extension line of the rotation axis and the rotation axis of the plate-making roll are viewed from the plane, the extension line of the rotation axis of the grinding wheel is perpendicular to the rotation axis of the plate-making roll. It is preferable to perform polishing to reduce the surface roughness, which is performed in a state in which a chord line parallel to the diameter line is brought into contact with the generatrix of the plate-making roll.

In the third step of measuring the roll diameter and eliminating the roll having an inaccurate accuracy, the printing substrate roll is mounted on a roll diameter measuring device, and from one end to the other end of the printing substrate roll at a constant pitch, for example, 10 mm. For each pitch, the diameter is measured with an accuracy of, for example, 5 μm (not shown). As a result of this measurement, a roll having a low roundness accuracy and a roll having a low cylindrical accuracy are not suitable for recycling and are therefore excluded.

In the step of performing the fourth wettability surface treatment, for example, a 0.15% aqueous solution of a silane coupling agent or a mixed solution of a small amount of ammonia and distilled water is sprayed and dried.

The fifth step of forming a plateable laser ablation film is a dipping method or a scan coating method using a laser-ablationable, conductive, chromium-plateable material using a yag laser or an excimer laser. 30μ by law (Japanese Patent Application No. 1-246049)
It is applied uniformly to a thickness of m to 40 μm and dried. (1) As a laser ablation material capable of chromium plating, for example, a binder polymer (5%), a photoinitiator (10%), a photopolymerizable or photocrosslinkable monomer (5%), and a particle size in a volume ratio. Is about 1-2 μm zinc powder (70-60
%) And carbon black (10 to 20%) are dispersed in a solvent so as to have the same viscosity as that of the paint paint. (2) As a laser ablation material capable of chromium plating, for example, a binder polymer (5%), a photoinitiator (10%), a photopolymerizable or photocrosslinkable monomer (5%), and a particle size by volume ratio. Is about 1-2μm zinc powder (80%)
When a viscous liquid dispersed in a solvent so as to have the same viscosity as that of a paint paint is used, it can be quickly dried by irradiating UV light after application. (3) As a laser ablation material capable of chromium plating, for example, a binder polymer (5%), a photoinitiator (10%), a photopolymerizable or photocrosslinkable monomer (5%), and carbon black by volume ratio When using a viscous liquid in which (80%) is dispersed in a solvent so as to have the same viscosity as that of a paint, it can be dried quickly by irradiating with UV light after application. (4) As a laser ablation material capable of chromium plating, for example, a binder polymer (5 to 8
%), A drying accelerator (2%), zinc powder (83-70%) having a particle size of about 1-2 μm, and carbon black (10-20%) in a solvent so as to have the same viscosity as that of the paint. When using a viscous liquid dispersed in water, it can be dried quickly by applying hot air after coating. (5) As a laser ablation material capable of chromium plating, for example, a binder polymer (5 to 8
%), A drying accelerator (2%) and zinc powder (93-90%) having a particle size of about 1-2 μm dispersed in a solvent so as to have the same viscosity as paint paint. Can be quickly dried by applying hot air after application. (6) As a laser ablation material capable of chromium plating, for example, a binder polymer (5 to 8
%) And a drying accelerator (2%) and carbon black (93 to 90%)
%), A viscous liquid dispersed in a solvent so as to have the same viscosity as that of the paint paint is used. Although quick-drying is not a constituent requirement of the present invention, since a plate-forming coating is formed so as to have a thickness of, for example, 30 to 40 μm in which the surface of the plate-making base material is not exposed when laser ablation is performed, the drying time is reduced. For shortening, a photoinitiator and a monomer or a drying accelerator are added. Photoinitiators and monomers are not compounded to create a latent image. The reason why the amounts of zinc dust and carbon black are extremely large is to secure conductivity and perform good electrochromic plating. The surface of the plate making substrate is not exposed when laser ablation is performed.
The reason why the film for forming a plate is formed so as to have a thickness of 30 to 40 μm is that, for example, when the film thickness is as thin as 10 μm, the bottom of the cell of the bra via plate is subjected to laser ablation and the surface of the plate for forming a plate (copper plating) In the shadow portion, the bonding strength of the coating to the plate forming substrate surface does not have sufficient resistance to the ink scraping force of the doctor, and the plating is applied to the copper plating surface at the bottom of the cell. This is because there is a problem that many cells are filled. Since the present invention does not perform etching, problems such as poor etching due to development residues do not occur. Rather, in the present invention, it is important that the plate-forming substrate surface is not exposed at the bottom of the cell of the bravia plate when the laser ablation is performed by increasing the film thickness. The binder polymer may be a combustible substance (any one of nitrocellulose, ethylene-vinyl acetate copolymer, unsaturated polyester resin, epoxy resin, allyl resin, polyurethane resin, polyethylene, polypropylene, polystyrene, polyacetal, natural rubber, etc.) Or a plurality of types: 75% by weight, and an oxidizing agent (ammonium nitrate or chloric acid compound:
10% by weight). Instead of zinc powder, zinc oxide powder may be used.

In the sixth step of forming an intaglio or relief printing plate by laser ablation, the coating is irradiated to a portion corresponding to the image portion by using a yag laser or an excimer laser to irradiate the coating with a laser. Ration. That is, the laser beam is absorbed by the film, converted into heat, and heated and evaporated instantaneously, thereby forming an intaglio or letterpress. When the undercoating surface of the coating, that is, a conductive surface such as a copper plating surface is exposed, the electrical conductivity between the conductive surface and the laser ablation material is different and plating is not performed well, so that the depth of engraving by laser ablation is performed. Is less than the thickness dimension. If the laser ablation material does not contain zinc dust, a semiconductor laser that emits laser light having a wavelength of about 800 nm can be used.

In the seventh chromium plating step, since there is no printing durability on the copper-plated printing plate, 5
Chrome plating of ~ 7 μm.

In the eighth step of sanding and chrome plating deburring, the chromium plating causes burrs on the edges of the cells. Therefore, the burrs are removed and the non-image areas are not properly mirrored but are not mirror-finished. This is performed in order to prevent the occurrence of plate fogging as a surface having a self-lubricating property with respect to the doctor blade by forming a sandpaper mark.

[0021]

As described above, the present invention has the following effects. Intaglio or letterpress can be manufactured by forming a coating for plate formation, laser ablation and chrome plating,
Rapid plate making can be performed in an extremely short process, and plate making costs can be halved. In the wet process, only a film is formed by coating, and waste liquid treatment is eliminated. Since development and etching are eliminated, skill and data management such as the type of water used, temperature management and time management are released. Since the intaglio or letterpress is engraved by laser ablation, the depth can be controlled according to the size of the cell, so that a fine gradation can be realized. A copper plating step, a cylindrical polishing step using a grindstone, a mirror finishing step using buff polishing, a step of coating and forming a photosensitive film, a laser exposure step, a development step, an etching step, and a resist peeling step are unnecessary. Since these facilities are not required, plate making can be performed in less than half the space as before, and plate making equipment costs are reduced by half. The diameter reduction value of the roll diameter due to the roll polishing in one recycling plate making is extremely small, and quick polishing is possible. When the plate is recycled more than ten times, the cumulative diameter of the roll diameter due to the grinding stone increases, and once every ten or more times, copper plating is performed and the grinding wheel cylinder is polished to expand to the first roll diameter. That way, it's enough for every recycling. It is not necessary to perform thick grinding and cylindrical grinding / mirror polishing each time recycling plate making is performed as in the related art.

[Procedure amendment]

[Submission date] October 15, 1999 (1999.10.
15)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

A gravure plate making method using a conventional electronic engraving machine is manufactured by, for example, the following steps 1) to 12). 1) The chromium plating is removed by etching with an aqueous solution of dilute sulfuric acid. 2) Measure the diameter of three to five points from one end to the other end of the printing roll, and eliminate the roll with low roundness accuracy and the roll with low cylindrical accuracy. 3) Perform corrective polishing to achieve precise cylindrical accuracy with a # 350 rough finish whetstone. 4) Using the same coarse finishing whetstone, perform plate drop polishing until the cells with the maximum depth are eliminated. 5) Polish the surface with a coarse finishing whetstone of # 500 and a rough finishing whetstone of # 800 in order to reduce the surface roughness. 6) Nickel plating so that the plating thickness is about 15 μm, and then copper plating so that the plating thickness is about 80 μm to 100 μm. 7) Polish the cylinder with a semi-finishing whetstone # 800 to # 1200 to remove the plating surface. 8) Polish the surface with # 1500 to # 4000 top finish whetstone to minimize surface roughness. 9) Mirror polishing with buff. 10) Form cells with an electronic engraving machine. 11) Chrome plating. 12) Deburr chrome plating.

Claims (2)

[Claims] 1. A plate is formed on a surface of a conductive plate-making base material with a laser ablation material capable of being chromium-plated so as to have a required film thickness such that the surface of the plate-making base material is not exposed when laser ablation is performed. To form a coating for
A plate making characterized by irradiating a portion corresponding to an image portion with a laser beam to ablate the coating portion thereof to form an intaglio or letterpress, and then forming chrome plating for imparting printing durability. Method. 2. A chromium plating on a used printing roll is removed, and then a coating made of a laser ablation material is removed to form a printing substrate roll to be reused. A laser ablation material is used to form a plate-forming film so as to have a required thickness so that the surface of the plate-making substrate is not exposed when laser ablation is performed. A plate making method characterized by forming a stencil plate or a relief plate by irradiating the film portion to form an intaglio or letterpress plate, and then forming chrome plating for imparting printing durability.