JPH1067088A - Printing plate and printing using printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regenerate a microprint image by removing a shielding layer corresponding to a print image, and irradiating a sensitive resin layer equivalent to a part from which the shielding layer is removed with an ionizing radiation to develop the sensitive resin layer. SOLUTION: A laminate 41 from which a printing plate is yet to be made is constituted of a sensitive resin layer 2 and a shielding layer 3 formed in that order on a base material 1. Next, only a part equivalent to a print image is written to the laminate 41 using a laser beam and the irradiation/chemical reaction process is performed in compliance with a signal to clean and remove the non-irradiated part. Thus a printing plate intermediate 42 with the exposed sensitive resin layer 2 of a non-image part is manufactured. In addition, the irradiated part of the shielding layer 3 and the entire surface of the sensitive resin layer 2 are irradiated with an ionizing radiation to make soluble only the sensitive resin layer of a part less the shielding layer 3. Further, the exposed sensitive resin layer 2 and the shielding layer 3 of an image part are dissolved with a developing solution to create a printing plate 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a resin plate comprising an ionizing radiation-sensitive resin layer and an ionizing radiation shielding layer, and a printing method using the same, particularly a decorative sheet for building materials.

[0002]

2. Description of the Related Art Heretofore, a photosensitive resin relief plate or a flexographic plate formed by exposing a plate of a photosensitive resin layer through a manuscript provided on a transmissive film and dissolving and removing an unexposed portion of the photosensitive resin layer is conventionally used. Plates (rubber letterpress) are known. However, the sharpness of an image may be inferior due to a gap generated between an original and a plate material at the time of exposure. There is a drawback in performing a complicated process such as performing vacuum contact exposure in order to avoid the contact unevenness between the original and the plate material. In addition, a photosensitive resin relief plate or a flexographic plate, which is formed by directly irradiating a high-power laser beam to a rubber-like elastic layer according to a write signal to partially remove the rubber-like elastic layer into a concave shape, is known. I have. However, when writing with a laser beam, a laser having a high output is required, and it is difficult to reproduce a fine printed image due to thermal diffusion at the time of writing.

[0003]

According to the present invention, in forming a letterpress printing plate, a relatively low-output laser beam or the like is applied to a writing signal without overlapping the original film and the plate material and performing vacuum contact exposure. The present invention provides a printing plate capable of reproducing a fine printed image by directly irradiating the printing plate material in accordance with the above, and provides a printing method suitable for a decorative sheet using the printing plate.

[0004]

Means for Solving the Problems In order to solve the above problems, the present invention provides an ionizing radiation-sensitive resin layer (hereinafter, referred to as a resin layer) on a substrate.
In the resin plate comprising a photosensitive resin layer) and an ionizing radiation shielding layer (hereinafter, referred to as a shielding layer), a step of removing a shielding layer corresponding to a portion that does not become a printed image, and removing the shielding layer A printing plate formed from a step of irradiating the photosensitive resin layer corresponding to the portion with ionizing radiation and a step of developing the photosensitive resin layer. Further, in the above printing plate, a printing plate provided with a low elastic layer which is lower than the elasticity of the sensitive resin layer after development and can be more easily deformed during printing, between the base material and the sensitive resin layer. . The printing plate has a thickness of the sensitive resin layer of 0.05 to 0.5 mm. Then, a printing method in which an ink thinned to a thickness of 1 to 20 μm is supplied to the printing plate to print and form an image on a printing medium. Further, there is provided a printing method in which ink is transferred to the printing plate via an ink supply sheet via an ink supply sheet, and an image is formed on a printing medium.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1A, an unprinted laminate 41 in which a sensitive resin layer 2 and a shielding layer 3 are sequentially provided on a substrate 1 is manufactured according to the present invention. Next, only the portion corresponding to the print image was irradiated and reacted using a laser beam in accordance with the write signal, the unirradiated portion was washed away, and the non-image portion of the photosensitive resin layer 2 was exposed (FIG. 1). The printing plate intermediate 42 shown in B) is manufactured. Then, the irradiated portion of the shielding layer 3 and the entire surface of the sensitive resin layer 2 are irradiated with ionizing radiation to solubilize only the portion of the sensitive resin layer from which the shielding layer has been removed. Then, the exposed photosensitive resin layer 2 and the shielding layer 3 in the image area are dissolved by a developer (for example, trichlorene) to form a printing plate 4 shown in FIG. 1C.

Further, a primer layer (not shown) is provided on the base material 1 as necessary to provide a low elastic layer 5 having a lower elasticity than that of the photosensitive resin layer 2 after development and which can be easily deformed at the time of printing. After that, the photosensitive resin layer 2 and the shielding layer 3 are further provided in order, writing is performed to insolubilize only the corresponding portion corresponding to the print image, and the unirradiated portion of the shielding layer is washed and removed. The printing plate shown in FIG. 2 is obtained by irradiating the surface with ionizing radiation to solubilize and developing only the sensitive resin layer in the portion where the shielding layer has been removed.

[0007] In the printing plate, after reacting or curing the shielding layer corresponding to the image, washing and removing the non-irradiated portion, the entire surface is treated with ionizing radiation, and the shielding portion and the irradiated portion of the photosensitive resin layer are exposed. Is dissolved and removed to produce a printing plate.
Of course, conversely, after the portion of the shielding layer that does not correspond to the image is directly removed by a laser oscillator or the like using a digital signal, the entire non-removed portion of the shielding layer and the image equivalent portion are irradiated with ionizing radiation, After reacting and curing the portion corresponding to the image of the photosensitive resin layer, the photosensitive resin layer in the non-image portion is developed by washing and removing to form a printing plate. In any of the methods, no special consideration such as vacuum treatment is required for the close contact between the film and the sensitive resin layer so that the resin forming the plate and the film serving as the original do not come into contact with each other.

The base material of the decorative sheet of the present invention may be a metal roll such as aluminum or iron, or a plastic roll such as polyester, polyamide or polyimide, or
Insert a sleeve made of aluminum, plastic, etc. into the roll for use.

The sensitive resin layer in the present invention comprises a prepolymer having a polymerizable unsaturated bond or an epoxy group in a molecule,
A composition that is sensitive to ionizing radiation and that is appropriately mixed with an oligomer and / or a monomer is used. Here, the ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking a molecule, and usually an ultraviolet ray or an electron beam is used.

The above prepolymers and oligomers include unsaturated polyesters such as condensates of unsaturated dicarboxylic acids and polyhydric alcohols, polyester methacrylates, polyether methacrylates, polyester acrylates, polyether acrylates, epoxy acrylates, urethanes and the like. There are acrylates such as acrylate polyol acrylate and melamine acrylate, and cationic polymerization type epoxy compounds.

The photosensitive resin layer which is sensitive to ultraviolet rays is formed of a compound having a compound having a diazo group as a photosensitive group, a compound having a compound having a photosensitive group of an azide group, or a compound having a compound having a photosensitive group of an azide group. There are compounds having a compound having a cinnamoyl group as a composition and compounds having a cinnamoyl group as a photosensitive group. Depending on the type of ionizing radiation-functional resin, the ionizing radiation-irradiated portion is cross-linked or polymerized, causing a reaction or effect. Some of them are dissolved and removed in the developer by disintegration / decomposition, and both can be used.

The elasticity of the sensitive resin layer after plate making is preferably such that the rubber hardness is 50 ° or more and 90 ° or less (however, the rubber hardness is measured by a spring hardness tester specified in JIS K6301). Are preferred. Rubber hardness is 5
When the angle is 0 ° or less, the printing tends to be crushed, and when the angle is 90 ° or more, the transfer of the ink to a printing medium having poor smoothness is inferior and the density is lowered. And the height (thickness) of the plate
Is preferably from 0.05 to 0.5 mm, and if it is 0.05 mm or less, the printing may be omitted (density reduction).
When the thickness is 0.5 mm or more, not only the reaction time is required, but also expensive resources are wasted. When a thickness such as a cushion is required, it is preferable to use it together with the low elasticity layer of the present invention.

The resin composition of the shielding layer 3 used in the present invention has a property of shielding ionizing radiation sensitive to the lower sensitive resin layer 2 and an energy not sensitive to the lower sensitive resin layer 2. Any material can be used as long as it has a physical property that it can form a portion that remains after development and a portion that can be removed during development. The thickness is preferably such that pinholes are not generated, and is preferably 1 to 20 μm which has a shielding effect, and it is needless to say that the minimum limit is preferably infinitely close to zero. For example, a low-melting metal thin film, one in which fine particles of a metal or metal oxide are dispersed in a thermoplastic resin, heat such as a thin film such as a dye or a pigment, a heat-sensitive material removed by infrared rays, and carbon black are dispersed in albumin. Heat-sensitive material whose solubility changes due to chemical change by heat and infrared rays (Nose, Inoue / Preprint of the Lecture by the Institute of Image Electronics Engineers of Japan, Vol. 37, pp. 6-9, 1
978) can be used. Here also, the method for removing the shielding layer includes a case where a portion to which writing energy is applied is removed and a case where the writing energy is added remains depending on the composition of the shielding layer. Both compositions can be used.

The low elasticity layer of the present invention is provided so as to support the sensitive resin layer of the upper high elasticity layer and to allow deformation according to the unevenness or rough surface of the printing paper as a printing medium. Things. It is formed of a material having a rubber hardness of 10 ° to 50 °. Specifically, various rubbers, for example, chloroprene rubber, nitrile rubber, butadiene rubber, urethane rubber,
Styrene / butadiene rubber, SBS rubber, ethylene / propylene rubber, polyvinyl cinnamate (KP rubber) and the like can be used. The height (thickness) of the low elasticity layer is determined in consideration of the hardness of the low elasticity layer itself and the degree of difficulty of deformation, and is usually 0.05 to 10 mm, preferably 0.1 to 10 mm.
1 mm.

The upper sensitive resin layer supported by the low elastic layer has an effect of preventing the image from being thickened and the image sharpness from being reduced due to excessive deformation of the low elastic layer. is there.

According to the method of the present invention for producing an unprinted laminate of a printing plate, a solution of the composition of the sensitive resin layer is applied to the substrate 1, and a solvent is dried and removed to form a coating film. Polishing may be performed to improve the smoothness of the coating film surface. Next, a solution of the shielding layer composition is applied, and the solvent is dried and removed to produce an unmade plate laminate 41 shown in FIG. At this time, for the purpose of strengthening the adhesion of the upper layer to the substrate, for example, isocyanate, or providing an epoxy-based primer layer,
A low elastic layer can also be formed. The base material used here is a metal roll of aluminum, iron, copper, etc.,
Examples thereof include those made of a metal sleeve, a plastic sleeve, or a sheet that can be adhered to a roll, which covers the roll.

Next, a printing method using the printing plate having the above configuration will be described. FIGS. 3 to 8 show a printing unit having "thin film forming means" for forming an ink thickness of 1 to 20 [mu] m (including a non-dried solvent) on the printing plate of the present invention. FIG. 3 shows that the ink supplied to the ink supply roll 8 is sequentially passed through a plurality of ink kneading roll groups 9 to form a thin film of the ink, and is formed on the convex portion of the printing plate 6 (set on the plate cylinder of the printing press). The ink is supplied, and the ink is supplied to the printing medium 20 by the pressure cylinder 7 to perform printing. This method can be applied to the case where an ink having a relatively high viscosity is supplied with an accurate ink thickness.

FIG. 4 shows another example of a printing unit.
And a single ink transfer roll 10 to form a thin film of ink and supply the ink to the printing plate 6. This method is suitable for supplying relatively low-viscosity ink.

FIG. 5 shows another example of a printing unit, in which low-viscosity ink is picked up by a fountain roll 12, a thin film of the ink is formed by an ink transfer roll 13, and the ink is supplied to the printing plate 6. Things. This is a method suitable for supplying ink having a relatively low viscosity.

FIG. 6 shows another example of a printing unit. The ink transfer roll 14 acts as a fountain roll, and the amount of ink is regulated by a doctor roll 15. This method is suitable for supplying a relatively low-viscosity ink in a wide range of ink amounts.

FIG. 7 shows a process in which the ink is picked up by an anilox roll 17 formed as an intaglio by engraving or etching, excess ink is scraped off by a doctor 16, and ink on the anilox surface is supplied to the printing plate 6 for printing. . This is an excellent method that can accurately control the amount of ink transfer by the number and depth of anilox lines. This method can also uniformly supply the ink to the anilox roll via the inking roll.

FIG. 8 shows a state in which ink is supplied in a squeezed state by an ink supply roll 19 to an endless ink supply sheet 18 made of fiber or non-woven fabric, and the ink is transferred from the sheet 18 to the printing plate 6 by a sheet pressure roll 21. And a method of printing on the printing medium 20. This method is suitable for printing using a small amount of low-viscosity ink.

In general, in flexographic printing, printing of a fine portion such as a conduit is poor in reproducibility, and particularly, crushing occurs, and ink transfer cannot be obtained uniformly in a solid portion requiring density. There was a problem of uneven density. These problems are not to use the above-mentioned original film, to form a plate on an unmade plate laminate, by appropriately using the above-mentioned various ink amount control methods, flexo printing, wood grain pattern,
Printing of decorative sheets with abstract patterns can be performed.

Hereinafter, embodiments of the present invention will be described in more detail.

(Example 1) A photosensitive resin composition of polyvinyl cinnamic acid (manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied to the surface of a substrate 1 shown in FIG. 1 which is in the form of an aluminum sleeve by a roll screen method and dried. Thus, a photosensitive resin layer 2 having a thickness of 0.2 mm was obtained. Next, the following “shielding layer composition” was applied to the surface and dried to form a shielding layer 3 having a thickness of 5 μm. "Shielding layer composition" ・ Egg albumin 20 parts by weight ・ Glycerin 10 parts by weight ・ Carbon black 10 parts by weight ・ Water 60 parts by weight On the other hand, a color negative film obtained by photographing a natural tree at the actual size with a camera is used with a color scanner. Three-color halftone separation was performed, and the relationship between the document density and the halftone dot density was adjusted for the characteristic of natural wood tone to obtain document data. The signal from the data is 4W,
The surface of the shielding layer 3 is irradiated with a laser beam intensity of 100 mV having a focal point of 3.0 m / sec by linking a laser beam focused at a wavelength of 488 nm of an argon laser with the printing information, and then washed with water to shield an unirradiated portion. The printing plate intermediate 42 from which the layer was removed was obtained. Next, the entire surface of the printing plate intermediate was irradiated with ultraviolet light for 1 minute using a 3 KW ultra-high pressure mercury lamp to react only the exposed sensitive resin layer from which the shielding layer was removed. Then, the reacted responsive resin layer was dissolved with a developer, trichlorene, and removed together with the shielding layer thereover to prepare a printing plate 4 of Example 1 having a rubber hardness of 80 °.

(Example 2) Nitrile rubber having a hardness of 50 ° was added to the surface of the aluminum sleeve-like base material 1 of Example 1 through an isocyanate-based primer layer in an amount of 0.1 mm.
It was formed with a thickness of 3 mm. Then, as in the first embodiment,
A polyvinyl cinnamic acid photosensitive resin composition (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied by a roll screen method and dried to obtain a photosensitive resin layer 2 having a thickness of 0.05 mm and a hardness of 80 °. Next, a shielding layer 3 having a thickness of 5 μm was formed on this surface, and a printing plate 4 as shown in FIG.

Using the printing plate 6 set on the plate cylinder of Example 1 and Example 2, the printing method shown in FIG.
Using an anilox roll set to μm, the amount of ink transferred to the plate was 2 μm, and the amount of ink transferred to the plate was 15 μm by the printing method shown in FIG. Table 1 shows the evaluation of the results obtained on thin paper of m ² . (Below)

[0028]

[Table 1] The evaluation of the print density is based on the condition that the ink is uniformly and sufficiently adhered to the paper of the printing medium, and the detail collapse is caused by the bleeding of the edge of the printing plate (the condition where the ink is pushed out to the periphery). (Marginal zone printed by) was visually evaluated. Evaluation criteria: E Very good G Excellent F No problem in practical use P As printed matter, there are many defects and it cannot be put to practical use.

[0029]

As described in detail above, the printing plate of the present invention has good printing density suitable for a decorative sheet for a building material and good printed matter with little crushing of details (marginal zone) inevitable in conventional flexographic printing. The effect is obtained.

[Brief description of the drawings]

FIG. 1 (A) is a cross-sectional view showing an unmade plate laminate of the present invention. (B) It is sectional drawing which shows the printing plate intermediate of the printing plate manufacturing process of this invention. (C) It is sectional drawing which shows the completed printing plate of this invention.

FIG. 2 is a sectional view showing a printing plate provided with a low elasticity layer.

FIG. 3 is a schematic sectional view of a roll arrangement in a printing unit provided with a plurality of ink mixing roll groups.

FIG. 4 is a schematic sectional view of a printing unit provided with a single ink transfer roll.

FIG. 5 is a schematic sectional view of a printing unit provided with a fountain roll.

FIG. 6 is a schematic cross-sectional view of a printing unit in which a fountain roll also serves as an ink transfer roll.

FIG. 7 is a schematic cross-sectional view of a printing unit that controls the amount of ink transferred by an anilox roll.

FIG. 8 is a schematic cross-sectional view of a printing unit that supplies ink to a plate by using an ink supply sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material 2 Sensitive resin layer 3 Shielding layer 4 Printing plate 41 Unprinted laminated body 42 Printing plate intermediate 5 Low elastic layer 6 Printing plate (set on the printing plate cylinder) 7 Impression cylinder 8, 19 Ink supply Roll 9 Plural ink kneading roll group 10, 13, 14 Ink transfer roll 11 Ink pan 12 Fanten roll (pickup roll) 15 Doctor roll 16 Doctor 17 Anilox roll 18 Ink supply sheet 20 Printed object 21 Sheet pressure roll

Claims (5)

[Claims] 1. A resin plate comprising a substrate and an ionizing radiation-sensitive resin layer and an ionizing radiation shielding layer, wherein a step of removing the ionizing radiation shielding layer corresponding to a printed image, a portion from which the ionizing radiation shielding layer is removed A step of irradiating the ionizing radiation-sensitive resin layer with ionizing radiation, and a step of developing the ionizing radiation-sensitive resin layer. 2. The printing plate according to claim 1, wherein the elasticity between the substrate and the ionizing radiation-sensitive resin layer is lower than the elasticity of the ionizing radiation-sensitive resin layer after development, so that the printing plate can be more easily deformed during printing. A printing plate comprising a low elasticity layer. 3. The printing plate according to claim 2, wherein the thickness of the ionizing radiation-sensitive resin layer according to claim 1 is 0.05 to 0.5 mm. 4. A printing method, characterized in that an ink thinned to a thickness of 1 to 20 μm is supplied to the plate surface of the printing plate according to claim 1, and an image is printed on a printing medium. . 5. A printing method, characterized in that an ink is supplied to the printing plate of claim 1, 2 or 3 via an ink supply sheet, and an image is printed on a printing medium.