JPH0743910A - Image forming method - Google Patents

Abstract

PURPOSE:To provide the method for forming the images well approximate to the images of printed matter without using a plate in accordance with digital information on the images. CONSTITUTION:This image forming method comprises forming at least two colors of the images by executing stages of forming punching holes on an image forming material composed of at least three layers; a base layer, a photosetting ink layer and a release layer, fixing this material by means of register pins, irradiating the material with a laser beam in accordance with the digital information, fixing the image forming material to the register pins and a transfer device having heating and pressurizing mechanisms, removing the release layer, transferring the unexposed parts of the photosetting ink layer to printing paper and irradiating the transferred images with UV rays. As a result, the images of plural colors are formed without generating a positional deviation and the images equiv. to the images of proof printing are easily obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming an image based on digital information of an image without using a plate.
Further, the present invention relates to a method for forming a proof image for verifying the completion of printed matter, that is, an image that closely resembles the printed matter, prior to mass printing by a printing press.

[0002]

2. Description of the Related Art Conventionally, in order to predict the quality of printed matter in advance of mass printing or to present a guarantee of quality,
A printing machine called a proofreading machine prints several printed materials. However, printing with a proof machine
It took a long time and a person skilled in printing technology. Moreover, the calibrator takes up space, is expensive, and requires an easier method. In response to such demands, a method for easily forming an image for proof without using a printing machine has been developed and used.

Examples of such a method include a method in which a negative or positive film is used and a silver salt or a photocurable adhesive layer is chemically changed by visible light or ultraviolet light. However, in the printing paper method using a silver salt, the difference in color and texture caused by the color of the pigment used in the printing ink and the color development of the dye by the silver salt may not be accepted as a proof image. ， The quality is not enough as the image for proofreading. Further, the method using a silver salt is not necessarily easy to handle because it has a troublesome process of developing and requires a waste liquid treatment of the developer. Further, since silver salt is used as a material, there is a problem that running cost is inevitably high.

Further, the photo-curing adhesive layer is chemically changed,
A method of forming an image by adhering each color toner made of a pigment to an adhesive portion and superimposing sheets of each color formed thereby to form an image is widely used. Since the thickness of the colored layer is significantly thicker than that of the printed material, there is a large difference in texture from the printed material, and there is a strong demand for a method of easily obtaining a material closer to the printed material. Further, since these methods form an image through a negative or positive film, it is impossible to directly output the image created on the computer screen.

As a method for directly obtaining an image for proofreading without using a negative or positive film, a method using an ink jet method, a method using a transfer film of a sublimation dye or a heat-melting wax ink film, a liquid toner or a dry toner is used. An electrophotographic method using-is devised. However, it is pointed out that the color difference between ink-jet and pigment used in printing ink is because the colorant of the ink is a dye. It is pointed out that the method using a sublimable dye also has a difference in color from the pigment.

Further, in the method using the sublimable dye, the printing sheet cannot be used as it is because the receiving sheet to be recorded is limited to the polyester material. The thermal transfer method using a heat-melting wax ink is cheap and reasonably priced, but the image quality is inferior to the transfer method using a sublimable dye, and higher image quality is required. Although the electrophotographic method using the liquid toner or the dry toner can obtain a high-resolution image relatively quickly, the color reproduction by the printing ink has not yet been sufficiently achieved.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above problems, the present inventors formed a punching hole in an image forming material, fixed it with a register pin, and then transferred the image to a printing paper. As a result, they have found that an image of a plurality of colors can be formed without causing a positional shift, and have completed the present invention. The image forming method of the present invention obtains an image for proof directly from digital image data, and further, the ink is transferred by a color similar to the printing ink and a transfer mechanism similar to the printing ink to perform proof printing. It aims to obtain an image with a texture that is very close to that printed by a printing machine.

[0008]

According to the present invention, a punching hole is formed in an image forming material composed of at least three layers of a support layer, a photocurable ink layer and a peeling layer, and after fixing with a register pin, Laser light is radiated based on digital information, and then the image forming material is fixed to a transfer device having a register pin and a heating / pressurizing mechanism. Then, the peeling layer is removed, and the photocurable ink layer on the printing paper is removed. Provided is an image forming method of forming an image of at least two colors by performing a step of transferring an unexposed portion and irradiating the transferred image with ultraviolet rays.

The image forming material in the present invention includes a support layer,
It is composed of at least three layers, a photocurable ink layer and a release layer. As the support layer, a material to which a photocurable ink adheres is preferable, and a smooth film having a sufficient strength to apply the photocurable ink is preferable. A polyester film is preferably used as such a film.

The photocurable ink layer contains 0.5 to 5 μm of an ink containing a pigment, a thermoplastic resin, an ultraviolet curable monomer, an oligomer, a solvent, a dispersant, a photoinitiator and a photosensitizer.
It is a layer that has been coated and dried to have a thickness of. As the pigment, a pigment for a process ink suitable as the three primary colors of subtractive color mixing or a pigment for a special color that cannot be expressed by the process ink is used, and a dye is also used as necessary. As the solvent, a ketone solvent or a hydrocarbon solvent is used.
In addition, a thermal polymerization inhibitor or the like is added to the photocurable ink as needed. The photocurable ink layer is an adhesive layer until it is irradiated with laser light, and the irradiated portion is cured by the irradiation of laser light. Then, the hardened part is fixed to the support layer and the adhesiveness to the printing paper disappears. On the other hand, since the non-irradiated portion of the laser light retains its adhesiveness, the ink layer is cohesively destroyed and transferred to the printing paper.

The peeling layer is a layer for laminating the ink surface immediately after coating and drying the photocurable ink on the support layer, and prevents stains such as scratches and dust adhesion on the ink surface. −
In the irradiation of light, it also works to prevent the inhibition of oxygen during photocuring. The release layer is a material that is easily released from the photocurable ink surface in a state where the ink sheet is fixed by the register pin to the transfer device having the register pin and the heating and pressing mechanism immediately after the laser light irradiation. Is used. For example, a highly transparent polyethylene film, a polypropylene film, a laminated film of a polyolefin film and a polyester film, a polyester film which has been subjected to a release treatment in advance, or the like is used.

The image forming material of the present invention is cut into a predetermined size and supplied, but it may be continuously supplied in the form of a roll. When irradiating with laser light, punching holes are provided in the image forming material. The punching holes are used as a means for aligning the register marks of the image forming materials of a plurality of colors, and the mountability and register accuracy for the register pins are affected by the material or thickness of the supporting layer or the peeling layer of the image forming material. To be done. Therefore, a material that does not break or deform the punching hole is preferable. As such a material, a polypropylene film, a laminated film of a polyolefin film and a polyester film, a polyester film which has been subjected to a release treatment in advance, etc. are used, and the registration accuracy, the handleability as a sheet (curling, bending, Wearability) is good.

The laser light is preferably one that radiates ultraviolet rays having a main wavelength of 363.6 nm, 351.1 nm, etc., and an argon laser is used. The output can be improved by enlarging the device itself, but the target is a laser with an output up to about 500 mw. Further, the laser beam is narrowed down by an optical system, but irradiation is performed by an optical system with little energy loss. Dots are formed by adjusting the laser on / off with an acoustic optical modulator (AOM) or the like. Also, the laser irradiation is a polygon mirror,
An existing method using an FΘ lens or the like can be used.

The irradiation of the laser beam is carried out by moving the image forming material on a plane and scanning it with laser light so that it is perpendicular to the flow direction of the image forming material. This can be performed by a method such as scanning with light or rotating the image forming material and causing the rotating body to scan with laser light. When the laser irradiation is performed on the negative portion based on digital data in which a normal image or inversion is taken into consideration, a positive image of a normal image can be obtained. After irradiating the laser light, the image forming material is mounted on the transfer device having the register pin in order to transfer the ink. After mounting, peel off the release layer from the ink surface. The peeling speed is
The same level as the transfer of the ink to the printing paper is preferable.

The transfer portion of the transfer device for transferring the ink of the image forming material is constituted by a heat and pressure roll. The preferred temperature between the roll nips is 70-130 ° C. If the temperature is lower than 70 ° C, improper transfer will occur and paper peeling will occur. Also, 130
If the temperature exceeds ℃, the deterioration of the paper will be accelerated and the paper will turn yellow. The pressure is 3 to 18 kgf / cm, and if the pressure is less than 3 kgf / cm, the deterioration of resolution becomes remarkable. If it exceeds 18 kgf / cm, mechanical assembly problems will occur. It is also difficult to maintain the registration accuracy. The support layer and the ink layer of the image forming material may be wound in synchronization with the transfer speed.

The printing paper is used in ordinary offset printing, gravure printing, etc., and is intended for printing paper equivalent to that used in proof printing. In particular, art paper is preferable from the viewpoint of smoothness, but even for matte coated paper with low smoothness, adjustment of the ink layer film thickness, transfer part temperature,
It can be handled by adjusting the speed and nip pressure. As the printing paper, a transparent or opaque film, an aluminum foil, a metal thin film, a surface-treated fiber woven fabric, a cloth, and a flat plate such as metal or glass can be used. The transferred image pattern is irradiated with ultraviolet rays having the energy required for curing the ink to fix the ink on the printing paper.

By carrying out the steps configured as described above, an image of at least two colors is formed. In the present invention, yellow, magenta, cyan, and black image forming materials are used, writing is performed by a laser based on digital information corresponding to each color, and uncured ink is transferred to a printing paper and uncured transfer ink is used. Repeated exposure to cure the
The ink of the image forming material used has almost the same color as the printing ink, and the transfer state of the transferred ink is similar to the transfer state of the printing ink. Is obtained.

[0018]

【Example】

Production of image-forming material An ink composition having the following composition was dispersed by a sand mill to produce. Yellow ink pigment ("Ryo Noruero FG1310" manufactured by Toyo Ink Manufacturing Co., Ltd.) 20 parts Diallyl phthalate ("DAPL" manufactured by Daiso Co., Ltd.) 30 parts Oligoester acrylate ("M-7100" manufactured by Toagosei Co., Ltd.) 14 parts Benzophenone 1 part Ethyl ketone 2.5 parts Methyl ethyl ketone 60 parts Toluene 10 parts

Magenta ink pigment (“Ryo Nour Red 7BFG4412” manufactured by Toyo Ink Mfg. Co., Ltd.) 18 parts Polyester resin (“Byron 300” manufactured by Toyobo Co., Ltd.) 30 parts Tetraethylene glycol diacrylate 10 parts Trimethylol propane triacrylate -To 10 parts benzophenone 1 part 2-hydroxy-2-methylpropiophenone 3 parts methyl ethyl ketone 60 parts toluene 10 parts

Cyan ink pigment (Toyo Ink Mfg. Co., "Rionolble-FG7330") 20 parts Diallyl phthalate (Daiso "DAPL") 30 parts Oligoester acrylate (Toa Gosei Co., Ltd. "M-7100" )) 14 parts Benzophenone 1 part 4,4-bisdiethylaminobenzophenone 2.5 parts Methyl ethyl ketone 55 parts Toluene 15 parts

Black ink pigment (“MA-7” manufactured by Mitsubishi Carbon Co., Ltd.) 10 parts Diallyl phthalate (“Isodap Mn45000” manufactured by Daiso Co.) 22 parts Dipentaerythritol hexaacrylate 15 parts Benzophenone 1 part 4,4-bis Diethylaminobenzophenone 2.5 parts Methyl ethyl ketone 70 parts Toluene 15 parts

A 12 μm polyethylene terephthalate film was coated with the above ink so as to have a dry thickness of 1.8 μm and dried. Then 8μ OPP and 50μ PE
The laminated film of T was laminated to produce each color image forming material (hereinafter referred to as an ink sheet) including a support layer, a photocurable ink layer, and a release layer. Holes were formed in one end of the black ink sheet by a punching machine. This hole
It was mounted on a laser irradiation machine with a register pin, and black information was patterned from the surface of a 12 µm polyethylene terephthalate film. The exposed ink sheet was mounted on a transfer machine having a register pin, and the release layer was removed. The ink surface from which the release layer had been removed was transferred to printing paper, and the transferred pattern was exposed to ultraviolet light.

Next, in the same manner as for the black ink sheet, after the cyan information was patterned, the peeling layer of the cyan ink sheet was removed, the ink surface was transferred to the printing paper on which the black pattern was formed, and then transferred. The pattern was exposed to UV light. Further, after patterning the magenta information in the same manner as the black ink sheet, the peeling layer of the magenta ink sheet is removed, the ink surface is transferred to the printing paper on which the black and cyan patterns are formed, and then the transferred pattern is formed. Exposed to UV light. Finally, in the same manner as the black ink sheet, after patterning the yellow information, the peeling layer of the yellow ink sheet was removed, and the ink surface was transferred to the printing paper on which the patterns of black, cyan and magenta were formed. Then, the transferred pattern was exposed to ultraviolet rays to form an image having a texture similar to that of a multi-colored printed product of four colors.

[0024]

According to the present invention, since the registration can be easily set with the punching hole and the register pin, it is possible to form an image of a plurality of colors without causing a positional deviation, and there is a printing engineer such as proof printing. Even if it is not, an image comparable to proof printing can be easily obtained. Further, according to the present invention, an image is directly formed from digital data without passing through a negative or positive photographic film. The image data created by a computer or the image data from a long distance is used. However, an image comparable to proof printing can be formed. Furthermore, by converting the digital data, it is possible to arbitrarily convert the normal image or the reverse image.

Claims (1)

[Claims] 1. A punching hole is formed in an image forming material composed of at least three layers of a support layer, a photocurable ink layer, and a peeling layer, and the punching hole is fixed with a register pin. After irradiating with light, the image forming material is fixed to a transfer device having a register pin and a heating / pressurizing mechanism, the peeling layer is removed, and the unexposed portion of the photocurable ink layer is transferred to the printing paper to transfer it. A method of forming an image, which comprises forming an image of at least two colors by performing a step of irradiating the formed image with ultraviolet rays.