JP2000238450A - Manufacture of original plate of direct lithographic waterless lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a yield and to upgrade productivity by sequentially laminating at least a layer for forming an image by emitting a laser beam, a silicone rubber layer and a synthetic sheet on a base plate, and then cutting it in a sheet-like state. SOLUTION: As a base plate, paper, a metal plate or the like of paper obtained by laminating plastics, aluminum (including an aluminum alloy), zinc, copper, iron or the like can be used. A layer for forming an image by emitting a laser beam needs to contain at least a photothermal conversion substance. As the substance, an additive such as a black pigment or the like of carbon black, titanium black, aniline black, cyanine black or the like is preferably added. As a silicone rubber layer, a material made of a silicone rubber composition used for a waterless lithographic printing plate is used. Synthetic paper is laminated before cutting in a sheet-like state in a manufacturing line, then it is cut together with the base plate, thereby improving yield without damaging the rubber layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a direct drawing type waterless planographic printing plate precursor.

[0002]

2. Description of the Related Art Direct plate making, in which an offset printing plate is produced directly from an original without using a plate making film, is simple, does not require skill, is quick in obtaining a printing plate in a short time, Utilizing features such as rationality that can be selected according to quality and cost from the system,
In addition to the light printing industry, it has begun to enter the general offset printing and gravure printing fields.

In recent years, new types of various lithographic printing materials have been developed recently due to rapid progress in output systems such as prepress systems, imagesetters, and laser printers.

[0004] Among these lithographic printing plates, a plate making method using a laser beam is excellent in terms of resolution and plate making speed, and there are many types thereof.

[0005] In particular, the thermal destruction method has an advantage that it can be handled in a bright room, and its usefulness has recently been reviewed due to the rapid progress of semiconductor lasers as light sources.

For example, JP-A-6-199064,
U.S. Pat. No. 5,339,737 and the like describe a direct drawing type waterless planographic printing plate precursor using a laser beam as a light source, a plate making method thereof, and the like.

The heat-sensitive layer of the printing plate precursor of this thermal destruction method is
Carbon black is mainly used as the laser light absorbing compound, and nitrocellulose is mainly used as the thermal decomposition compound. And this carbon black is converted into heat energy by absorbing laser light,
Further, the heat destroys the heat-sensitive layer. And finally,
By removing this portion by development, the silicone rubber layer on the surface is peeled off at the same time, forming an ink-filled portion.

JP-A-9-146264 discloses a compound for converting laser light into heat, a polymer compound having a film forming ability, a photopolymerization initiator, and a photopolymerizable ethylenically unsaturated compound in a photothermal conversion layer. There has been proposed a negative type laser-sensitive waterless planographic printing plate precursor in which a light-to-heat conversion layer and a silicone rubber layer are reacted by subjecting the entire surface to exposure with energy rays after forming a silicone rubber layer.

In this plate material, the adhesive force between the silicone rubber layer and the photosensitive layer is improved by subjecting the entire surface of the plate material to exposure after coating with the silicone rubber layer. As a result, a plate material excellent in image reproducibility and scratch resistance is obtained. ing.

Japanese Patent Application Laid-Open No. 9-239942 proposes a release development type printing plate containing a substance which generates an acid in a laser sensitive layer and a polymer compound which is decomposed by the action of an acid. Two steps, a light irradiation step and a heating step, are required, and there is a problem inherent in peeling development that reproducibility of fine halftone dots is poor.

When producing these direct-drawing waterless planographic printing plates, if they are cut into sheets in a production line and laminated, the front surface of the waterless planographic printing plate precursor and the back surface of the substrate are in direct contact with each other.
There was a problem that the surface was scratched and the yield was extremely reduced.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a direct-drawing waterless planographic printing plate precursor having improved yield and excellent productivity.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to stack at least a layer for forming an image by irradiating a laser beam on a substrate, a silicone rubber layer and a slip sheet in this order, and then cut the sheet into sheets. This is achieved by a method for producing a direct drawing type waterless lithographic printing plate precursor characterized by the following.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

First, the direct drawing type waterless planographic printing plate precursor of the present invention will be described. The direct-drawing waterless planographic printing plate precursor of the invention preferably has a composition of a heat-sensitive image forming method.

As the substrate, paper, paper laminated with plastic, metal plate of aluminum (including aluminum alloy), zinc, copper, iron, etc., cellulose acetate, polyethylene terephthalate, polyethylene, polyamide, polyimide, polystyrene, polypropylene And a plastic film such as polycarbonate, polyvinyl acetal, and the like, and a paper or plastic film on which a metal is laminated or vapor-deposited as described above.

Of these, the aluminum plate is particularly preferable because it is extremely stable in dimension and inexpensive. Further, a polyethylene terephthalate film used as a substrate for light printing is also preferably used.

In order to strengthen the adhesion between the substrate and the heat-sensitive layer, it is preferable to perform a surface treatment such as an etching treatment, a corona treatment and a plasma treatment. In particular, when a plastic film such as polyethylene terephthalate or polyethylene naphthalate is used for the substrate, the substrate itself plays a role of a heat insulating layer from a high heat insulating property. Therefore, it is particularly preferable to increase the adhesiveness by such a surface treatment. .

On the other hand, when the substrate is made of a material having a relatively high thermal conductivity, such as a metal, a heat insulating layer may be provided between the substrate and the heat-sensitive layer for the purpose of improving adhesiveness and heat insulating effect. preferable.

[0020] As preferably used for the heat insulating layer,
Examples include epoxy resin, polyurethane resin, phenol resin, acrylic resin, alkyd resin, polyester resin, polyamide resin, urea resin, polyvinyl butyral resin, casein, gelatin and the like. These resins can be used alone or in combination of two or more.

The thickness of the heat insulating layer is 0.5 to 50 as a coating layer.
g / m ² is preferable from the viewpoint of heat insulation effect, effect of preventing morphological defects on the substrate surface and blocking chemical adverse effects, and economical efficiency, and more preferably 1 to 10 g / m ² .

In order to enhance the heat insulating effect of the heat insulating layer,
It is also preferable to provide independent or continuous voids in the heat insulating layer.

Next, a layer for forming an image by a laser beam will be described.

In the present invention, the layer for forming an image by laser light needs to contain at least a photothermal conversion substance.

Examples of the light-to-heat conversion material include black pigments such as carbon black, titanium black, aniline black and cyanine black, phthalocyanine and naphthalocyanine green pigments, carbon graphite, diamine metal complexes, dithiol metal complexes, and phenol thiol compounds. Metal complexes, mercaptophenol-based metal complexes, water-containing inorganic compounds, copper sulfate, chromium sulfide, silicate compounds,
Titanium oxide, vanadium oxide, manganese oxide, iron oxide,
Metal oxides such as cobalt oxide and tungsten oxide, hydroxides and sulfates of these metals, as well as bismuth, iron,
It is preferable to add additives such as magnesium and aluminum metal powder.

Of these, carbon black is preferred from the viewpoints of light-to-heat conversion, economy and handling.

In addition to the above substances, dyes that absorb infrared or near infrared rays are also preferably used as photothermal conversion substances.

Examples of such dyes include cyanine dyes, azurenium dyes, squarylium dyes, croconium dyes, azo-based disperse dyes, bisazostilbene dyes, naphthoquinone dyes, anthraquinone dyes,
Perylene dyes, phthalocyanine dyes, naphthalocyanine metal complex dyes, polymethine dyes, dithiol nickel complex dyes, indoaniline metal complex dyes, intermolecular CT dyes, benzothiopyran spiropyrans, nigrosine dyes and the like are preferably used.

The content of these light-to-heat converting substances is preferably from 0.1 to 40% by weight, more preferably from 0.5 to 25% by weight, based on the total heat-sensitive layer composition. When the amount is less than 0.1% by weight, the effect of improving the sensitivity to laser light is not seen, and when it is more than 40% by weight, the printing durability of the printing plate tends to decrease.

Other compounds preferably contained in the heat-sensitive layer include nitro group-containing compounds such as nitrocellulose, hydrazine derivatives, azo compounds, azide compounds, and the like.
An easily decomposable compound such as a carbonate compound can be used.

A heat-sensitive layer containing a metal chelate compound can also be preferably used.

As the metal chelate compound, Al, S
i, Ti, Mn, Fe, Co, Ni, Cu, Zn, G
e, In, Sn metal diketenates, metal alkoxides, alkyl metals, metal carboxylate salts, metal oxide chelate compounds, metal complexes, heterometal chelate compounds, among which particularly preferred compounds are aluminum, Iron (III), titanium acetylacetonate (pentanedionate), ethyl acetoacetonate (hexanedionate), propylacetoacetonate (heptanedionate), tetramethylheptanedionate, benzoylacetonates, etc. .

The amount added to the heat-sensitive layer is preferably 3 to 50% by weight, more preferably 10 to 30% by weight of the solid content. When the amount is less than 3% by weight, the effect, that is, the effect of improving the image reproducibility is lowered, while when it is more than 30% by weight, the physical properties of the heat-sensitive layer are liable to be reduced. This is because the problem of printability is likely to occur.

When a metal chelate compound is used, a phenolic hydroxyl group-containing compound, an alcoholic hydroxyl group-containing compound, an amino group-containing compound, a carboxyl group-containing compound, a diketone group-containing compound and the like are added from the viewpoint of interaction with the metal chelate compound. Is preferred.

The addition amount of these compounds is preferably 5 to 60% by weight, more preferably 2 to 60% by weight, based on the total heat-sensitive layer composition.
0 to 50% by weight. If the amount is less than 5% by weight, the effect is small, and if it is more than 60% by weight, the solvent resistance of the printing plate tends to decrease.

In the present invention, it is preferable that the heat-sensitive layer further contains a binder polymer. In this case, as the binder polymer, from the viewpoint of printing durability of the printing plate, a polymer or copolymer having a glass transition temperature (Tg) of the polymer of 20 ° C. or lower, more preferably a polymer or copolymer having a glass transition temperature of 0 ° C. or lower It is preferable to use

Specific examples of the binder polymer include vinyl polymers, unvulcanized rubber, polyoxides (polyethers), polyesters, polyurethanes, polyamides and the like.

The content of these binders is preferably from 5 to 70% by weight, more preferably from 10 to 50% by weight, based on the total heat-sensitive layer composition. When the content is less than 5%, problems are likely to occur in printing durability and coating properties of the coating solution, and when the content is more than 70% by weight, image reproducibility tends to be adversely affected.

The above various binder polymers may be used alone, or may be used by mixing several kinds of polymers.

Next, the silicone rubber layer will be described.
In the present invention, examples of the silicone rubber layer include those made of a silicone rubber composition used in a conventional waterless lithographic printing plate.

Specific examples include those obtained by sparsely cross-linking a linear organopolysiloxane (preferably dimethylpolysiloxane).

The crosslinking method may be a condensation type or an addition type, but an addition type is preferred from the viewpoint of handling.

When performing condensation type crosslinking, tin, zinc,
It is preferable to add a metal carboxylate such as lead, calcium or manganese, or a catalyst such as chloroplatinic acid.

In the addition type, platinum alone, platinum chloride,
It is preferable to add a catalyst such as chloroplatinic acid or olefin-coordinated platinum.

For the purpose of controlling the curing rate of the addition type silicone rubber layer, it is preferable to add a reaction inhibitor such as an unsaturated group-containing compound.

In addition to these compositions, the addition type silicone rubber composition may be added with a hydroxyl group-containing organopolysiloxane or a hydrolyzable functional group-containing silane (or siloxane) which is a composition of the condensation type silicone rubber layer. Good.

Further, a filler such as silica may be added to these silicone rubber layer compositions for the purpose of improving rubber strength.

Further, in the present invention, the silicone rubber layer preferably contains a silane coupling agent in addition to the above composition.

The thickness of these silicone rubber layers is 0.5 to
It is preferably 20 g / m ² , more preferably 0.5 to 5 g / m ^2.
g / m ² . When the film thickness is less than 0.5 g / m ^2, the ink repellency, scratch resistance and printing durability of the printing plate tend to decrease, and when the film thickness is more than 20 g / m ² , it is disadvantageous from an economic viewpoint. In addition, there is a problem that the ink mileage deteriorates.

Next, a method for producing a direct drawing type waterless planographic printing plate precursor and a plate making method in the present invention will be described.

A heat-insulating layer composition is applied, if necessary, on a substrate which has been subjected to various treatments as required, the solvent is volatilized by heating, and the composition is cured by the action of heat or light. The composition is applied, and the solvent is volatilized by heating and, if necessary, cured by the action of heat or light. Thereafter, the silicone rubber composition is applied and heat-treated at a temperature of 50 to 150 ° C. for several minutes to obtain a silicone rubber layer.

The plate thus obtained may be laminated with a protective film or formed with a protective layer for the purpose of protecting the silicone rubber layer.

Therefore, it is preferable that the protective film does not hinder the irradiation of the laser beam. Specific examples thereof include a polyester film, a polypropylene film, a polyvinyl alcohol film, a saponified ethylene-vinyl acetate copolymer film, and a polyvinylidene chloride. Films and the like.

In the method for producing a direct-drawing waterless planographic printing plate precursor according to the present invention, it is necessary to further laminate interleaving paper. In the present invention, the slip sheet is a sheet of paper to be inserted in order to prevent the surface of the printing plate precursor from touching the back surface of the substrate when the printing plate precursor cut into a sheet is overlapped, thereby damaging the silicone rubber layer. That is.

As the interleaf paper, high quality paper, medium quality paper, lower grade paper,
Coated paper, synthetic paper and the like can be used, but lower-grade paper is preferred from the viewpoint of economy. Both continuous paper and sheet-shaped paper can be used, but when continuous paper is laminated and the direct-drawing waterless planographic printing plate precursor is cut into sheets, the paper can also be cut at the same time. More desirable in terms of productivity.

The direct-drawing waterless planographic printing plate precursor thus obtained is exposed imagewise with a laser beam after the protective film is peeled off or, preferably, from above the protective film.

The laser light source used in the plate-making exposure step of the present invention has an emission wavelength range of 300 nm to 1500.
Although those having a wavelength in the range of nm are used, among these, a semiconductor laser having an emission wavelength region near the near infrared region is preferably used.

The original plate after laser irradiation can be developed by friction treatment in the presence or absence of water or an organic solvent. The developed plate can be printed by a known method.

[0059]

The present invention will be described in more detail with reference to the following examples. Example 1 An aluminum coil (manufactured by Sumitomo Metal Co., Ltd.) was set in a coil unwinder 1 of a waterless lithographic apparatus shown in FIG. 1 and pretreated by an ordinary method to obtain a solution having the following composition. The coating is performed using the heat insulating layer coating device 2 and the drying
° C., and dried for 2 minutes, provided a heat insulating layer of 3 g / m ^2. <Heat insulation layer> (a) Epoxy / phenol resin “Cancoat” 90T
-25-3094 (manufactured by Kansai Paint Co., Ltd.): 15 parts by weight (b) "Crystal Violet": 0.1 parts by weight (c) Dimethylformamide: 85 parts by weight Next, the heat insulating layer has the following composition The heat-sensitive layer composition is applied by the heat-sensitive layer coating device 4, and dried at 120 ° C.
For 1 minute to provide a heat-sensitive layer having a thickness of 2 g / m ² . <Thermal Sensitive Layer> (a) “KAYASORB” IR-820B (infrared absorbing dye, manufactured by Nippon Kayaku Co., Ltd.): 10 parts by weight (b) Iron (III) acetylacetonate (manufactured by Hanoi Chemical Co., Ltd.): 30 parts by weight (c) "Sumilite Resin" PR50622 (phenol novolak resin, manufactured by Sumitomo Durez Co., Ltd.): 50 parts by weight (d) "SAMPLEN" T-1331 (polyurethane resin manufactured by Sanyo Chemical Industries, Ltd., glass transition Temperature Tg: -3
7 ° C.): 50 parts by weight (e) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxypropyltrimethoxysilane =
1/3/1 molar ratio addition reactant: 10 parts by weight (f) tetrahydrofuran: 1000 parts by weight (g) dimethylformamide: 350 parts by weight Next, a silicone rubber layer composition having the following composition was applied by a silicone rubber layer coating apparatus 6. Apply and dry in dryer 7
The composition was thermally cured at 20 ° C. for 1 minute, and a silicone rubber layer having a dry film thickness of 2.0 g / m ² was applied. <Silicone rubber layer> (a) α, ω-divinylpolydimethylsiloxane (polymerization degree: 770): 100 parts by weight (b) HMS-501 (manufactured by Chisso Corp., both terminals methyl (methylhydrogensiloxane) (dimethylsiloxane)) Copolymer Number of SiH groups / Molecular weight = 0.69 mol /
g): 4 parts by weight (c) Olefin coordinated platinum: 0.02 parts by weight (d) "BY24-808" (a reaction inhibitor manufactured by Dow Corning Silicone Co., Ltd.): 0.3 parts by weight (e) "Isopar""E (isoparaffinic hydrocarbon,
Exxon Chemical Co., Ltd.): 1000 parts by weight On the laminate obtained as described above, an 8 μm thick polypropylene film “Trefane” BO (Toray Industries, Inc.)
Is laminated using a film laminating device 8, and a lower-grade paper-changed paper (manufactured by Daishowa Paper Co., Ltd.) is cut into a sheet as an interleaf of the present invention before it is cut into sheets.
After that, a direct drawing type waterless lithographic printing plate precursor formed by cutting into a sheet shape with the online cutter 10 was laminated on the piler 11 by 200 plates. Example 2 A direct-drawing waterless planographic printing plate precursor was produced in the same manner as in Example 1 except that the compositions of the heat insulating layer, the heat-sensitive layer, and the silicone rubber layer were changed to those shown below. 200 plates were laminated. <Heat insulation layer> (a) Polyurethane resin “Miractolane” P22S (manufactured by Nippon Miractran Co., Ltd.): 100 parts by weight (b) Blocked isocyanate “Takenate B83”
0 "(manufactured by Takeda Pharmaceutical Co., Ltd.): 20 parts by weight (c) Epoxy / phenol / urea resin" SJ937 "
2 "(manufactured by Kansai Paint Co., Ltd.): 8 parts by weight (d) Dibutyltin diacetate: 0.5 part by weight (e)" FINEX "25 (white pigment, Sakai Chemical Co., Ltd.)
): 10 parts by weight (f) "KET-YELLOW" 402 (yellow pigment, manufactured by Dainippon Ink and Chemicals, Inc.): 10 parts by weight (g) Dimethylformamide: 720 parts by weight <Thermosensitive layer> (a) Nitro Cellulose (viscosity 1/2 second, nitrogen content 1
1.0% "Bergerac NC") (S.N.
15% by weight (b) Carbon black (# 30 manufactured by Mitsubishi Chemical Corporation):
20 parts by weight (c) Resole resin "Sumilac" PC-1 (manufactured by Sumitomo Durez Co., Ltd.): 10 parts by weight (d) Epoxy resin "Denacol" EX-421 (manufactured by Nagase Kasei Kogyo Co., Ltd.): 10 parts by weight (E) Butylated benzoguanamine resin "Tessazine" 3
073-60 (manufactured by Hitachi Chemical Co., Ltd.): 5 parts by weight (f) Fluorosurfactant "Fluorard" FC430
(Manufactured by Sumitomo 3M): 0.1 parts by weight (g) Dimethylformamide: 100 parts by weight (h) Methyl ethyl ketone: 700 parts by weight <Silicone rubber layer> (a) Polydimethylsiloxane (molecular weight of about 35,000)
0, terminal hydroxyl group): 100 parts by weight (b) Vinyl tris (methylethyl ketoxime) silane: 8 parts by weight (c) Dibutyltin diacetate: 0.5 parts by weight (d) "Isopar E" (isoparaffinic hydrocarbon,
Exxon Chemical Co., Ltd.): 1400 parts by weight Comparative Example 1 A direct-drawing waterless planographic printing plate precursor was produced in the same manner as in Example 1 except that the interleaf paper of the present invention was not laminated. No. 11 was stacked on 200 plates. Comparative Example 2 A direct-drawing waterless planographic printing plate precursor was produced in the same manner as in Example 2 except that the interleaf paper of the present invention was not laminated, and 200 plates were laminated on the pillar 11.

Table 1 shows the results of examinations of the silicone rubber layers in Examples 1 and 2 and Comparative Examples 1 and 2 for the presence or absence of flaws.

[0061]

[Table 1]

As can be seen from Table 1, by laminating the interleaf paper of the present invention, a direct-drawing waterless planographic printing plate precursor having no damage to the silicone rubber layer is obtained, and the yield is improved.

[0063]

According to the present invention, in a manufacturing process of a direct-drawing waterless planographic printing plate precursor, interleaf paper is laminated before being cut into sheets in a production line, and then the interleaf paper is cut simultaneously with the substrate. Thus, a direct-drawing waterless planographic printing plate precursor having no scratch on the silicone rubber layer can be obtained, and the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic drawing of the manufacturing process of a direct drawing type waterless lithographic plate.

[Description of Signs] 1: Unwinder 2: Primer layer coating device 3: Dryer 4: Photosensitive layer coating device 5: Dryer 6: Silicone rubber layer coating device 7: Dryer 8: Protective film laminating device 9: Combination Paper laminating machine 10: Online cutter 11: Piler

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 2H096 AA13 BA01 BA20 CA20 EA04 EA23 LA30 2H114 AA05 AA15 AA21 AA23 AA28 AA30 BA01 BA10 DA05 DA08 EA08 GA01 GA31

Claims (1)

[Claims] 1. A direct drawing type waterless lithographic printing method comprising laminating at least a layer for forming an image by irradiating a laser beam, a silicone rubber layer and an interleaf sheet on a substrate in this order, and cutting the sheet into sheets. The method of manufacturing the master plate.