JPH06222572A - Image forming method - Google Patents

Abstract

PURPOSE:To provide a method to form an image without using a printing plate according to digital information of the image. CONSTITUTION:The method includes the following processes. First, the image is formed by ink-jet method on the supporting layer or peeling layer of an ink sheet consisting of at least three layers of supporting layer, photosetting ink layer and peeling layer. This image is formed according to digital information and does not transmit UV rays. In the second process, the ink sheet is exposed to UV rays through the side where the image which does not transmit UV rays is formed. The image which does not transmit UV rays is patterned on the photosetting ink layer. The third process, the peeling layer is peeled from the photosetting ink layer so that the photosetting ink not exposed to UV rays is transferred to a printing sheet. Thereby, ink can be transferred according to the digital information of the image with same colors as printing inks and same transfer mechanism as printing with inks. The image almost same quality of printing as proof printing is obtd.

Description

Detailed Description of the Invention

[0001]

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 an image for proofreading for verifying the finished product of a printed matter, that is, an image having a texture that closely resembles the printed matter, prior to mass printing by a printing machine.

[Prior art]

2. Description of the Related Art Conventionally, as a method of predicting the quality of a printed matter in advance or presenting a guarantee of the quality before a large amount of printing, a printing machine called a proofing machine prints several printed matters. However, since this printing is performed using a printing machine, it requires a person skilled in the printing technology and time. In addition, this calibrator requires 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.

As such a method, there is 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. In addition, the method using silver salt is
It is not always easy to handle, as it has a troublesome development process and requires 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 adhering each color toner made of a pigment to the adhesive portion and superimposing the sheets of each color produced thereby is widely used, but it is widely used. Since the thickness is significantly thicker than the printed matter, there is a large difference in texture from the printed matter, and there is a strong demand for a method that can easily obtain a printed matter that is closer to the printed matter. Further, these are for outputting an image through a negative or positive film, and for example, it is impossible to directly output an image created on a computer screen.

On the other hand, 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 sublimation dye transfer film or a heat-melting wax ink film, a liquid toner is used.
Alternatively, an electrophotographic method using a dry toner has been devised. However, it is pointed out that the inkjet method is different from the pigment used in the printing ink because the coloring material of the ink is a dye. It is pointed out that the method using sublimable dyes is also different 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.

In the heat-sensitive transfer method using a heat-melting wax ink, the apparatus 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. The electrophotographic method using a liquid toner or a dry toner can obtain a high-resolution image relatively quickly, but the color reproduction with 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 inventors of the present invention have found that an ink support comprising at least three layers of a support layer, a photocurable ink layer and a release layer is supported. An ultraviolet opaque image is formed on the layer or release layer by an inkjet method based on digital information, and then exposed to ultraviolet light to pattern the ultraviolet opaque image on the photocurable ink layer, and then exposed to ultraviolet light. By transferring the photocurable ink that has not been printed onto the printing paper, it is possible to directly obtain an image for proofreading from digital image data. Moreover, the ink has the same color as the printing ink and the same transfer mechanism as the printing ink. It was found that an image having a quality very similar to that obtained by transferring the image with a proof press can be obtained, and the present invention has been completed.

[0008]

The present invention provides an ink-jet support layer or release layer comprising at least three layers of a support layer, a photocurable ink layer, and a release layer, and an inkjet system based on digital information. To form an image of UV opacity, exposing the UV opaque image from the side where the image is formed, and patterning the UV opaque image on the photocurable ink layer. Provided is a method for forming an image, which comprises a step of separating from a photocurable ink layer and transferring the photocurable ink that has not been exposed to ultraviolet rays onto a printing paper.

The ink is composed of at least three layers of a support layer, a photo-curable ink layer and a release layer. The support layer is preferably a material such that photocurable ink adheres thereto, and a smooth transparent film having sufficient strength to apply the photocurable ink, for example, a polyester film is used. The photo-curable ink layer includes a coloring material, a thermoplastic resin, an ultraviolet-curable monomer or oligomer, a ketone-based or hydrocarbon-based solvent, a photoinitiator, a photosensitizer if necessary, and a dispersion. It is formed by coating an ink containing additives such as a chemical agent and a thermal polymerization inhibitor to a thickness of 0.5 to 5 µ, and drying. As the coloring material, a pigment for a process ink suitable as the three primary colors of subtractive color mixing, a pigment for a special color that cannot be expressed by the process ink, or a dye is used if necessary. The photocurable ink layer is an adhesive layer until it is irradiated with ultraviolet rays, and the irradiated portion is cured by the irradiation of ultraviolet rays. Then, the hardened part is fixed to the support layer and the adhesiveness to the printing paper disappears. In addition, since the non-irradiated part of the ultraviolet ray retains its adhesiveness, it causes cohesive failure and is transferred to the printing paper.

The peeling layer is a layer for laminating on the ink surface immediately after coating and drying the photocurable ink on the support layer, and is used for preventing stains such as scratches and adhesion of dust on the ink surface. It protects and also prevents the inhibition of oxygen during photocuring during UV irradiation. The release layer is a material that is easily released from the photo-curable ink surface immediately after irradiation with ultraviolet rays, and has a good transparency such as polyethylene film, polypropylene film, polyester film with release treatment in advance, or polyolefin film and polyester. A laminated film of films or the like is used. This ink
May be supplied after cutting into a certain size.
It can also be supplied in the form of a roll and continuously.

To form an image, first, an ultraviolet ray opaque image is formed on the supporting layer or the peeling layer of the ink sheet by an ink jet method based on digital information. Drawing by the inkjet method is preferably performed while the ink is in contact with a mirror-like rotary drum in order to eliminate the blurring of the drawing position caused by the vibration accompanying the flow of the ink. Alternatively, drawing may be performed by a serial type printer. Further, it is more advantageous to perform drawing on the support layer from the viewpoint of resolution because the support layer is thin and light scattering is small. However, when the release layer is transparent, there is no problem in forming the pattern even if drawing is performed from the release layer side. However, when the drawing is performed on the peeling layer, the image is inverted by the transfer, so that the drawing data needs to be converted at the time of the drawing.

As an ink jet system for forming an ultraviolet ray opaque image based on digital information, a charge amount control system, an ink on demand system, a spray system, a bubble jet system, a sweet system, an electrolytic control system, an ion mist system, etc. Can be used. However, since the support layer and the release layer are plastic sheets, the charge amount control method, the ink-on-demand method and the like are preferable in consideration of the adhesion of the ink to the sheet and the drying property. The ink is made by dissolving a coloring material that blocks the transmission of ultraviolet rays, a solvent and, if necessary, a binder,
Alternatively, the product is well dispersed by a disperser such as a sand mill, a ball mill, or an attritor, and is manufactured through a filtration process.

As the coloring agent, carbon black, azo lake type, insoluble azo type, condensed azo type, phthalocyanine type, dioxazine type, isoindolinone type, anthraquinone type, perylene type, thioindigo type, perinone type, miloli blue, iron oxide, Organic or inorganic pigments and dyes such as cobalt blue, ultramarine blue, dark blue, and titanium oxide can be used alone or in combination. These colorants may be used properly according to the color of the ink sheet, but for patterning, it is sufficient to draw in a single color, and it is not necessary to change the color.

As the solvent, ketone type, alcohol type,
It is possible to use organic solvents such as cellosolve-based, chlorine-based, aromatic-based, aliphatic-based, and water. Due to the adhesion and drying properties of the ink, a pigment dispersion type ink in which a binder component is dissolved using an organic solvent is recommended. preferable. As the binder, an acrylic resin, a polyurethane resin, a vinyl resin, a cellulose rubber resin, a phenol resin, a polyamide resin, an epoxy resin, or the like is used. Further, in order to stably disperse the pigment, a surfactant, a dispersion stabilizer or the like can be used. Further, an additive for adjusting resistance may be added if necessary.

Next, UV exposure is performed from the side on which the UV opaque image is formed, and the UV opaque image is patterned on the photocurable ink layer. After that, the release layer is released from the photocurable ink layer, and the photocurable ink that has not been exposed to ultraviolet rays is transferred to the printing paper. Transfer of the photo-curable ink that has not been exposed to UV light is performed with a heat and pressure roll. The preferred temperature between the roll nip is 70-130 ℃,
The pressure is 3 to 8 kgf / cm. The printing paper on which the photo-curable ink that has not been exposed to ultraviolet rays is transferred is irradiated with ultraviolet rays of the energy required for curing the ink to fix the ink. The printing paper is a paper equivalent to that used in normal offset printing, gravure printing and proof printing, and the paper may be supplied in a roll shape or a sheet shape.

In the image forming method of the present invention, ultraviolet-impermeable images are formed by an ink jet system based on digital information corresponding to each color by using yellow, magenta, cyan, and black inks. A process of exposing the opaque image side to ultraviolet light to pattern the photocurable ink layer, then peeling off the release layer, and transferring and fixing the uncured part of the photocurable ink layer to printing paper. When the ink is used, the ink 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. An image very close to is obtained.

[0017]

EXAMPLES The present invention will be described below with reference to examples. In the examples, “part” means “part by weight” and “%” means “% by weight”. [Example 1] An ink composition having the following composition was produced by dispersion with a sand mill. Yellow Ink Lionol Ero FG-1310 (Toyo Ink Mfg. Co., Ltd. Pigment) 20 parts Diallyl phthalate DAPL (Daiso Thermoplastic Resin) 30 parts M-7100 (Toagosei Co., Ltd. Oligoester Acrylate) 14 Part benzophenone 1 part ethyl ketone 2.5 parts methyl ethyl ketone 60 parts toluene 10 parts magenta ink lionol red 7BFG4412 (Toyo Ink Mfg. Co., Ltd. pigment) 18 parts Byron 300 (Toyobo Co., Ltd. thermoplastic resin) 30 parts tetraethylene glycol diacryle To 10 parts Trimethyl propane triacrylate 10 parts Benzophenone 1 part 2-Hydroxy-2-methylpropiophenone 3 parts Methyl ethyl ketone 60 parts Toluene 10 parts

Cyan ink Lionolble FG-7330 (Pigment manufactured by Toyo Ink Mfg. Co., Ltd.) 20 parts Diallyl phthalate DAPL (thermoplastic resin manufactured by Daiso) 30 parts M-7100 (Oligester ester acrylate manufactured by Toagosei Co., Ltd.) ) 14 parts Benzophenone 1 part 4,4-bisdiethylaminobenzophenone 2.5 parts Methyl ethyl ketone 55 parts Toluene 15 parts Black ink Mitsubishi Carbon MA-7 (pigment manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) 10 parts Diallylphthalate Isodap Mn45000 22 parts ( Daiso thermoplastic resin) Dipentaerythritol hexaacrylate 15 parts Benzophenone 1 part 4,4-bisdiethylaminobenzophenone 2.5 parts Methyl ethyl ketone 70 parts Toluene 15 parts

A 12 μm polyethylene terephthalate film was coated with each of the above color inks to a dry thickness of 1.8 μm and dried. Then, an 80 μm polyethylene film was laminated to produce each color ink consisting of a support layer, a photocurable ink layer, and a release layer. Based on the digital information of the black ink plate, the inks below were used to draw on the ink ink sheet support layer with a charge amount control type ink jet printer to form a UV impermeable image.

Inkjet Ink Lionol Blue KL (Toyo Ink Mfg. Co., Ltd. Pigment) 8 parts AT-100 (Toyo Ink Mfg. Co., acrylic resin solution, NV50%) 25 parts Cyclohexanone 50 parts SanEris 911 (Sanyo Chemical Co., Ltd. acrylic type) Dispersant) 2 parts Algomer S (Cheating agent manufactured by Kawaken Fine Chemicals Co., Ltd.) 0.5 part Methyl ethyl ketone 33 parts Toluene 6 parts Sodium thiocyanate 1.3 parts Add 10 parts of methyl ethyl ketone to the pigment, resin solution, dispersant and chelating agent. Dispersed well with a sand mill. After dispersion, the mixture was diluted with the remaining solvent, sodium thiocyanate was added, and the mixture was filtered with a filter to prepare an ink.

Next, the ink sheet having a UV-opaque image formed on the support layer was exposed to UV light from the support layer side. Next, the release layer was released, and the photocurable ink layer was transferred to printing paper (art paper). Transfer was performed at 95 ° C and 7 kg / cm. Then, the transferred ink surface was exposed to ultraviolet rays to fix the transferred ink. Similarly, in the same manner, the cyan ink sheet is printed with the cyan plate information, the magenta ink sheet is printed with the magenta plate information, and the yellow ink sheet is printed with the yellow plate information. I drew each of them, aligned these sheets, and transferred them to printing paper. The order of transfer was black, cyan, magenta, and yellow. However, since the finish of the image is affected, the transfer order can be appropriately changed according to the color arrangement of the image.

[0022]

INDUSTRIAL APPLICABILITY According to the present invention, an image comparable to proof printing can be directly formed from digital data without using a negative or positive photographic film, which is easy even if there is no printing engineer such as proof printing. An image for proof can be formed on. Also,
An image comparable to proof printing can be formed even with image data created by a computer or image data from a long distance. This has the effect of promoting filmlessness from this conventional work place, and changing the work place and environment. Further, according to the present invention, it is possible to arbitrarily convert a normal image or a reverse image by converting digital data. Furthermore, according to the present invention, it is possible to provide a quick and stable high-quality image.

Claims (2)

[Claims] 1. An ultraviolet impermeable image is formed by an inkjet method on the basis of digital information on an ink support layer or a release layer composed of at least three layers of a support layer, a photocurable ink layer and a release layer. Step of forming, UV exposure from the side on which the UV opaque image is formed, patterning the UV opaque image on the photocurable ink layer, and then peeling off the release layer from the photocurable ink layer. , An image forming method including a step of transferring a photocurable ink which has not been exposed to ultraviolet rays onto a printing paper. 2. An ink portion not exposed to ultraviolet rays,
The image forming method according to claim 1, wherein the image is transferred onto a printing paper under transfer conditions of 70 to 130 ° C. and 3 to 8 kgf / cm.