JPH1010709A - Plate making method of photosensitive resin letterpress - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to execute plate making of a photosensitive resin letterpress material without using a photographic negative film by forming images on the surface of a photosensitive resin layer by liquid or powder ink. SOLUTION: This method comprises a stage for printing the surface of the photosensitive resin layer with image data obtd. by integrating handwritten manuscripts, block copies used from heretofore or characters, graphics and photographs and a stage for irradiating the photosensitive resin layer with active rays through the images and photosetting the resin of the irradiated parts. The formation of the images on the photosensitive layer is executed by imparting the images of adequate blackening densities on the layer by using a commercially marketed ink jet device, laser printer or thermal transfer device, etc. The formation of the photoset and rugged images is executed by manufacturing a printing plate by irradiation with active rays by using a commercially marketed exposure device. The plate making of the photosensitive resin letterpress is executed without using the photographic negative film of a silver salt and non-silver salt by combining these stages.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of making a relief plate of a photosensitive resin, and more particularly to a method of making a relief plate without using a photographic negative film.

[0002]

2. Description of the Related Art When making a printing plate, a photographic negative film on which an image obtained by various methods such as a normal printing, a hand drawing, a CAD, or an image integration system is printed is brought into close contact with a photosensitive resin plate. After irradiating an actinic ray such as ultraviolet light or visible light from the upper surface of the photosensitive resin layer, a predetermined eluent is used to elute and remove the photosensitive resin layer corresponding to the non-exposed area, thereby forming a printing uneven image. Such a method of producing a printing plate is called a photoengraving method, or plate making for short. It has been applied to various plate formats such as letterpress, planographic, gravure, and screen printing, and various plate making methods using computers have been developed and put to practical use.

[0003] However, the form of the printing market is changing significantly. That is, the environment surrounding the industry is undergoing drastic changes, such as diversification of the market, small lots / multiple types, on-demand, strengthening of environmental regulations, and pursuit of profits by reducing printing costs. The photographic negative film accounts for a very high proportion of the items under consideration in solving these problems. Methods for preventing and stabilizing the quality deterioration that occurs in the negative film production process, or for making a plate without the interposition of the negative film are being studied. A method of making a plate without interposing a negative film has already been used for plate making of lithographic and gravure printing plates, and is described in Keisuke Iguchi Printing Magazine, Vol.
12 (1994), pp. 33-40, describes a technical trend. In the same book, as a means for making a lithographic printing plate, after irradiating the recording layer with a laser beam in accordance with an image signal, the recording layer at the irradiated portion is removed or developed by an electrophotographic method using toner. It describes an example of imparting hydrophilicity or lipophilicity to a site.

[0004]

If the photographic negative film does not need to be used in the plate making process, the economic effect brought about by the technical development is expected to be extremely large. Problems with conventional negative films often include problems such as generation of pinholes, adhesion of dust, insufficient concentration, and fogging during preparation. These phenomena are difficult to avoid even with careful work, and as a result are one of the factors that significantly reduce the quality of the printing plate. Plate making methods that do not involve a negative film have been put to practical use in planographic and gravure plates, but have not yet come into practical use in plate making of photosensitive resin relief plates.

[0005]

Even if an image using liquid or powder ink is formed on the surface of the photosensitive resin layer, it can be put to practical use for applications that do not require printing of fine images, such as packaging material printing. Thus, the present invention has been completed.

Further, in the case of an image formed by a photographic negative film, the density of the non-image area must be 2.7 or more, and the density of the image area must be 0.05 or less in order to prevent fogging. In the case of an image using a color material such as toner or ink, there is no fear that fogging will occur as long as the density of the non-image area is 2.7 or more. That is, only the density of the non-image area is defined, and the fog density may be ignored as in the case of using a film because the image area is the photosensitive resin itself. The present invention makes it possible to make a photosensitive resin relief plate using an image of a coloring material such as toner or ink provided on the photosensitive resin layer, unless high image quality and high resolution are required. .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In forming an image for use in plate making according to the present invention, a hand-drawn manuscript, a conventionally used printing plate,
Alternatively, there is used an image data obtained by integrating characters, figures, and photographs, and a device that receives the signal and prints a printing object on a thin film. The above-described printing apparatus is an ink-jet apparatus, a laser printer,
Any of the thermal transfer devices can be used. All of these devices are designed to obtain a positive image, but in the present invention, they must be inverted to a negative image. In order to invert an image, it is necessary to change the circuit of each device. However, in an electrophotographic apparatus, an apparatus employing a reversal developing method can be applied.

The coloring material is desirably a lipophilic composition in all of the ink jet system, electrophotographic system and thermal transfer system in consideration of the adhesiveness to the polymer thin film. Toner is liquid,
Any of powder toners can be used. In the present invention, if the photosensitive resin relief printing plate is a solid-state printing plate, it can be used for both relief printing and flexographic printing.

The components and composition of the image-imparting material are determined by the image forming apparatus. In the present invention, a thermoplastic polymer material such as a polymer oil, an acrylic resin, an alkyd resin, an epoxy acrylic resin, or a urethane acrylic resin is suitable as the vehicle. The selection of the material of the thermoplastic compound is easy, and the blackening density value of the image-imparting material is preferably at least 2.7 as described above. The black pigment carbon black is suitable for obtaining the above blackening density values.

[0010]

The operation of the present invention and the results of plate making tests will be described.

The present invention relates to a step of printing on a photosensitive resin layer image data obtained by integrating a hand-drawn manuscript, a conventionally used composition, or characters, figures, and photographs; And irradiates the photosensitive resin layer through the substrate to photo-cure the resin at the irradiated portion. To form an image on the photosensitive layer, a commercially available inkjet device,
Using a laser printer, a thermal transfer device, or the like, an image having an appropriate blackening density is provided on the layer. In order to form photo-curing and a concavo-convex image, the photosensitive resin layer is photo-cured by irradiating an actinic ray with a commercially available exposure device, and then a non-image portion is eluted and removed to produce a printing plate. By combining these steps, plate-making of a photosensitive resin relief plate can be performed without using a silver salt or non-silver salt type photographic negative film.

EXAMPLE 1 A photosensitive resin flexographic plate (Nippon Denshi Seiki Co., Ltd.) was prepared by using a laser printer (Personal Printer MQ-2000S / J, manufactured by Alps Electric Co., Ltd.) under a milk carton prepared for the production of a photographic negative film. (Gem plate H28: photosensitive resin layer thickness: 2.84 mm).
Flexo plate making exposure machine (JE-A0- manufactured by JEOL Ltd.)
Exposure is performed using HSH) until the exposure amount reaches 3200 mj / cm ² . After the exposure, elution is performed with a predetermined eluent (Gemsolve, manufactured by JEOL Ltd.) in an elution apparatus (JW-A0-SDR, manufactured by JEOL Ltd.) to obtain an uneven image. Thereafter, the mixture is heated at 80 ° C. for 60 minutes to remove the remaining eluate, and front-side exposed for 10 minutes with a flexo plate-making exposure machine to obtain a printing plate for flexographic printing.

Example 2 A toner image on a photosensitive drum is sensitized using a laser printer designed so that a photosensitive flexographic printing plate having a thickness of 1 to 10 mm can be inserted into a transfer portion of a laser printer having a resolving power of 400 dip. Transfer to resin flexographic plate material. After the transfer, the same processing as in Example 1 is performed to obtain a printing plate for flexographic printing.

Example 3 An image is formed by applying a liquid ink onto a photosensitive flexographic printing plate material using an ink jet apparatus previously adjusted so as to output a negative image. A printing plate is obtained.

[0015]

The present invention is useful for plate making of a photosensitive resin relief plate material which does not require a photographic negative film.
In the lithographic plate making industry, what has been already put into practical use, but not in letterpress plate making, so-called filmless plate making is also applicable to letterpress plate making,
It brings effects such as labor saving in the letterpress plate making process, cleaner plate making environment, and the ability to cope with small lots and diversification.

Claims (3)

[Claims] 1. A photosensitive resin relief printing plate material having a photosensitive resin layer capable of forming a concavo-convex image for printing, wherein an image is directly provided on a surface of the photosensitive resin layer, and an image is formed from the upper surface of the image. A method of making a plate for letterpress printing by irradiating a light beam to elute and remove a non-image portion. 2. The relief printing plate according to claim 1, wherein the image-imparting material contains at least one selected from liquid inks and powder inks having a lipophilic substance and a blackening concentration of 2.7 or more. How to make a plate. 3. A letterpress printing method comprising the step of transferring letterpress printing ink adhered to the surface of the photosensitive resin layer of the letterpress printing plate according to claim 1 to a printing medium.