JP2001225566A - Original plate for direct lithographic type lithographic printing plate and method for manufacturing direct lithographic type waterless lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a direct lithographic type lithographic printing plate having good image reproducibility. SOLUTION: An original plate for the direct lithographic type lithographic printing plate comprises at least a heat sensitive layer on a base plate. In this case, the layer contains a compound having a structure represented by formula I, wherein M is a metal atom or an organic component, (A) is an organic polymer component, (B) is an organic molecular component, n and m are each an integer of 1 or more, and 1 is an integer of 0 or 1 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct drawing type lithographic printing plate precursor that can be directly made by laser light.
In particular, the present invention relates to a direct drawing type waterless planographic printing plate precursor capable of printing without using dampening solution.

[0002]

2. Description of the Related Art A so-called direct drawing type plate making, in which an offset printing plate is produced directly from an original without using a plate making film, is simple, which does not require skill, rapidity in which a printing plate can be obtained in a short time, Taking advantage of features such as rationality that can be selected from various systems according to quality and cost, the company has begun to enter not only the light printing industry but also the fields of general offset printing and flexographic printing. In particular, a new type of various direct-drawing lithographic printing plates has recently been developed with the rapid progress of output systems such as a prepress system, an image setter, and a laser printer. These direct-drawing lithographic printing plates can be classified according to plate-making methods, such as a method of irradiating a laser beam, a method of writing with a thermal head, a method of partially applying a voltage with a pin electrode, an ink repellent layer or an ink-coated layer by inkjet. And the like. Above all, the method using laser light is resolution,
It is superior to other methods in terms of plate making speed and there are many types.

[0003] The printing plate using the laser light further includes:
There are two types: a photon mode by photoreaction and a heat mode in which photothermal conversion is performed to cause a thermal reaction. In particular, the heat mode 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 a semiconductor laser as a light source.

A lithographic printing plate in a heat mode, particularly a waterless lithographic printing plate which does not require dampening water at the time of printing, and a method for producing the same have heretofore been proposed as follows. Had a problem.

For example, JP-A-6-199064 discloses
JP-A-6-186750, JP-A-6-55723, JP-A-6-55869, JP-A-10-85
No. 8, JP-A-10-31317, JP-A-10-31317
JP-A-39496 and JP-A-10-329310
And JP-A-11-11037 are proposals on a method for forming a printing plate based on ablation of a heat-sensitive layer. These have the advantage of simple development, but require a high laser output to ablate the heat-sensitive layer, and have a bad effect on the optical system due to the generation of by-products such as gas due to ablation. There are problems such as the possibility of the influence, the necessity of removing the ablation residue, and the difficulty in reproducing minute halftone dots.

JP-A-9-80747 and JP-A-10-80747
-58635, JP-A-10-62977,
JP-A-10-171105 and the like propose a release development in which an ink-repellent layer in a laser-irradiated portion is released by using an adhesive release sheet formed on an ink-repellent layer before and after laser irradiation. . The advantage is simple development, but there is a problem that it is very difficult to reproduce minute halftone dots.

[0007] Further, as a method for producing a printing plate using a developer, the following proposals have been made.

Japanese Patent Application Laid-Open No. 10-34868 discloses that after laser irradiation, the surface tension is 25 to 50 dyn / cm ² (25
５０50 × 10 ⁻⁶ N / cm ² ) is applied and rubbed, but there is a problem that the ink repellent layer is easily scratched because the ink repellent layer is swollen and rubbed. .

JP-A-10-146945 also proposes that after laser irradiation, the ink repellent layer on the plate surface is swollen with a treatment liquid containing a nonpolar solvent containing at least 70% of an aliphatic hydrocarbon. In addition, there has been a problem that the ink repellent layer is easily damaged in the developing step.

Japanese Patent Application Laid-Open No. Hei 10-100361 proposes rubbing in the absence of a liquid after laser irradiation, and then rubbing in the presence of a liquid. Conversely, rubbing in the absence of a liquid is proposed. In the process, there was a problem that the ink repellent layer was damaged because the frictional force was too large.

JP-A-11-198335, JP-A-11-58667, JP-A-11-207921 and the like disclose a method of irradiating a laser-irradiated portion in the presence of water or water containing a surfactant after laser irradiation. This is a proposal for removing the ink repellent layer. However, these methods can reproduce a certain number of halftone dots, but have a problem that the reproducibility of minute halftone dots is unstable and the ink deposition of halftone dots is poor.

Japanese Patent Application Laid-Open No. 11-221977 and the like have proposed a direct-printing printing plate having a metal chelate compound in a heat-sensitive layer. However, the printing plate is not sufficiently resistant to various solvents used in the plate making process and the printing process. However, there was no problem, and the sensitivity was not sufficient for practical use.

[0013]

SUMMARY OF THE INVENTION The object of the present invention is to improve the drawbacks of the prior art by providing a compound having a specific structure in a heat-sensitive layer to provide a direct-drawing lithographic printing plate having good image reproducibility. Is provided.

[0014]

The direct drawing type lithographic printing plate precursor of the present invention mainly has the following constitution in order to solve the above-mentioned problems. That is, a direct drawing lithographic printing plate precursor having at least a heat-sensitive layer on a substrate, wherein the heat-sensitive layer contains a compound having a structure represented by the following general formula (I). A planographic printing plate precursor M (A) n (B) m (C) l (I) (M is a metal atom or an organic component, A is an organic polymer component,
B is an organic low-molecular component, C is an organic low-molecular component, n and m are integers of 1 or more, and l is 0 or an integer of 1 or more. ) ".

The method for producing a direct-drawing waterless planographic printing plate of the present invention mainly has the following constitution. That is, a method for producing a direct-drawing waterless lithographic printing plate having, on a substrate, a thermosensitive layer containing at least a compound having a structure represented by the following general formula (I), and an ink repellent layer in this order:
(1) a step of causing the surface layer of the heat-sensitive layer to react by laser irradiation, (2) a step of treating with an organic solvent, and (3) a step of removing the ink repellent layer of the laser irradiated part by brushing in the presence of water. A method for producing a direct-drawing waterless lithographic printing plate, characterized in that: M (A) n (B) m (C) l (I) (M is a metal atom or an organic component, A is an organic polymer component,
B is an organic low-molecular component, C is an organic low-molecular component, n and m are integers of 1 or more, and l is 0 or an integer of 1 or more. ) ".

[0016]

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

A feature of the present invention resides in that a compound having a structure represented by the following general formula (I) is contained in the heat-sensitive layer.

M (A) n (B) m (C) l (I) (M is a metal atom or an organic component, A is an organic polymer component,
B is an organic low-molecular component, C is an organic low-molecular component, n and m are integers of 1 or more, and l is 0 or an integer of 1 or more. )

The compound having the structure represented by the general formula (I) includes, for example, (a) a polymer component having a reactive functional group and two or more functional groups having different reactivity in one molecule. It can also be obtained by reacting a compound or by reacting (b) a polymer component having a reactive functional group with a molar ratio of a compound having a reactive functional group. Ease of reaction, especially when M is a metal atom,
From the viewpoint of structural uniformity of the obtained compound, image reproducibility of the printing plate, etc., it is preferable to obtain the compound by the method (a). When M is an organic component, it is preferably obtained by the method (b) for the same reason. It is preferable to obtain.

The polymer component having a reactive functional group includes a hydroxyl group, an amino group, a mercapto group, an allyl group, a vinyl group, an acrylic group, a methacryl group, a carboxyl group,
A polymer compound having an aldehyde group, an epoxy group, or the like, preferably a hydroxyl group, a carboxyl group, an amino group, or an acetylacetone group is exemplified. Specifically, phenol, cresol, novolak resin and resol resin obtained by the condensation reaction of phenols such as xylenol and formaldehyde, phenol / furfural resin, furan resin, unsaturated polyester resin, polyhydroxystyrene, hydroxystyrene and vinyl monomer Copolymer,
Examples include, but are not limited to, hydroxyl group-containing polyurethane resins and rosin-modified maleic acid resins. Of these, novolak resins, resole resins, and homo- and copolymers of hydroxystyrene are preferred.

When M is an organic component, the functional group of the organic compound having a reactive functional group includes an isocyanate group, a vinyl group, an acryl group, a methacryl group, an allyl group, a carboxyl group, an aldehyde group, a hydroxyl group, Amino group, mercapto group, alkoxy group, aryloxy group, silyl group, alkoxysilyl group, epoxy group, azide group,
And a diazo group.

Specific examples of the organic compound include tolylene diisocyanate, diphenylmethane diisocyanate,
Xylylene diisocyanate, hexamethylene diisocyanate, triphenylmethane triisocyanate, tris (isocyanatophenyl) thiophosphate,
Polyfunctional isocyanates such as 1,3,6-hexamethylene triisocyanate and their polyol adducts and polymers; phthalic acid, adipic acid, azelaic acid, trimellitic acid, methylcyclohexentricarboxylic acid, pyromellitic acid, etc. Polyfunctional amino group-containing compounds such as polyvalent carboxylic acid, melamine, benzoguanamine and urea, epoxy group-containing compounds such as bisphenol A type epoxy resin and epoxy-modified phenol resin, glycerol dimethacrylate, glycerol monomethacrylate, glycerin methacrylate acrylate, pentaerythritol tri Examples include polyfunctional acrylates such as methacrylate, 2-hydroxy-1,3-dimethacryloxypropane, and tetramethylolmethane triacrylate. The present invention is not limited to these.

For example, a compound represented by the general formula (I) in which M is an organic compound is obtained by reacting triphenylmethane triisocyanate with methanol equivalent to twice the molar amount and then reacting with a phenol novolak resin. I can do it. In this example, M is a triphenylmethane triisocyanate skeleton, the organic polymer component of A is a phenol novolak resin, and the organic low molecular component of B is ethanol.

When M is a metal atom, examples of the organometallic compound having two or more kinds of functional groups having different reactivity in one molecule include the above-mentioned two or more kinds of functional groups in the organic group bonded to the metal. May have, or may have two or more ligands having different reactivities, but an organometallic compound having two or more ligands having different reactivities is preferable. In such a case, the ligand may be the organic low molecular component in the general formula (I).

The organic metal compounds include Al, Ti, M
n, Fe, Co, Ni, Cu, Zn, Ge, In, S
Organometallic compounds having metal atoms such as n, Zr, and Hf are preferable, but Ti, Zr, Hf are preferable in terms of the number of ligands.
Those having four or more ligands such as f, Sn, and In are preferable. In addition, it is particularly preferable to use two types of ligands, namely, alkoxides and β-diketones such as acetylacetone, benzoylacetone, and ethyl acetoacetate, because the reactivity is greatly different.

Specific examples of the organometallic compound include aluminum bisethylacetoacetate monoacetylacetonate, aluminum diacetylacetonate ethylacetoacetate, aluminum monoacetylacetonate bispropylacetoacetate, aluminum monoacetylacetonate bisbutylacetoacetate, Aluminum monoacetylacetonate bishexyl acetoacetate, aluminum monoethyl acetoacetate bispropyl acetoacetonate, aluminum monoethyl acetoacetate bisbutyl acetoacetonate, aluminum monoethyl acetoacetate bishexyl acetoacetonate, aluminum monoethyl acetoacetate bisnonyl Acetoacetonate, aluminum dibutoxide monoa DOO acetate, aluminum dipropoxide Sid mono acetoacetate, aluminum dibutoxide monoethyl acetoacetate, aluminum -s-
Butoxide bis (ethyl acetoacetate), aluminum di-s-butoxide ethyl acetoacetate, aluminum-9-octadecenyl acetoacetate diisopropoxide, titanium allyl acetoacetate triisopropoxide, titanium di-n-butoxide (bis-
2,4-pentanedionate), titanium diisopropoxide (bis-2,4-pentanedionate), titanium diisopropoxide bis (tetramethylheptanedionate), titanium diisopropoxide bis (ethylacetoacetate) ), Titanium methacryloxyethyl acetoacetate triisopropoxide, titanium oxide bis (pentanedionate), zirconium allyl acetoacetate triisopropoxide, zirconium di-n-butoxide (bis-2,4-pentanedionate), zirconium Diisopropoxide (bis-2,
4-pentanedionate), zirconium diisopropoxide bis (tetramethylheptanedionate), zirconium diisopropoxide bis (ethyl acetoacetate), zirconium methacryloxyethyl acetoacetate triisopropoxide, zirconium butoxide (acetyl Acetate) (bisethylacetoacetate) and the like, but are not limited thereto.

Compounds having the structure represented by the general formula (I) include novolak resins, resol resins, homo- and copolymers of hydroxystyrene, and titanium di-n-
Butoxide (bis-2,4-pentanedionate),
Titanium diisopropoxide (bis-2,4-pentanedionate), titanium diisopropoxide bis (tetramethyl heptandionate), titanium diisopropoxide bis (ethyl acetoacetate), zirconium di-n-butoxide ( Bis-2,4-pentanedionate), zirconium diisopropoxide (bis-
Compounds obtained by a reaction such as 2,4-pentanedionate) and zirconium diisopropoxide bis (ethylacetoacetate) are particularly preferred.

In the compound having the structure represented by the general formula (I), the number n of the polymer component A is preferably 2 or more from the viewpoint of resistance to various solvents used in the plate making step and the printing step of the printing plate. It is preferable that the number m of the low molecular component B is large from the viewpoint of high sensitivity. The number 1 of the low-molecular component C is preferably large from the viewpoint of high sensitivity, but is preferably 0 or 1 in view of the number n of the high-molecular component A and the number m of the low-molecular component B. Further, M is preferably a metal atom from the viewpoint of image reproducibility of the obtained printing plate. A specific preferred structure is represented by the following general formula (I
Compounds having the structures of I) to (VIII) are mentioned, and among them, (III), (IV) and (VI) are particularly preferable.
The structure of (VII) is preferred.

M (A) ₂ (B) ₁ (II) M (A) ₂ (B) ₂ (III) M (A) ₂ (B) ₁ (C) ₁ (IV) M (A) ₃ (B ) ₁ (V) M (A) ₂ (B) ₃ (VI) M (A) ₃ (B) ₂ (VII) M (A) ₄ (B) ₁ (VIII) (M is a metal atom, A is an organic The high molecular components, B and C are organic low molecular components.)

FIG. 1 shows an example of the particularly preferred structure (III).

In this example, M is a titanium atom, the organic polymer component of A is a novolak resin, and the organic low molecular component of B is acetylacetone.

As a method of incorporating the compound having the structure represented by the general formula (I) into the heat-sensitive layer, a compound having the structure represented by the general formula (I) is synthesized in advance and then heat-sensitive. A method for preparing a heat-sensitive layer by adding it as one component constituting the layer, or mixing a compound serving as a raw material of a compound having a structure represented by the general formula (I) with other heat-sensitive layer components A method in which a compound having a structure represented by the general formula (I) is contained in the heat-sensitive layer as a result of reacting them during application and drying of the heat-sensitive layer solution.

The reason why excellent image reproducibility can be obtained by having the compound having the structure represented by the general formula (I) in the heat-sensitive layer is considered as follows. First, the resistance to various solvents used in the plate making process and the printing process of the printing plate is exhibited by the interaction between M and A. Regarding image reproducibility and sensitivity to laser irradiation, B and / or
Alternatively, it is achieved by the presence of C. That is, it is considered that the interaction between B and M is weakened by the action of heat generated at the time of laser irradiation, and that the swelling rate and solubility of the heat-sensitive layer with respect to the processing solution used in the developing step are changed by releasing B and / or C. .

The proportion of the compound having the structure represented by the general formula (I) in the heat-sensitive layer is 20 to 95% by weight, more preferably 40 to 80% by weight of the total solids of the heat-sensitive layer. Preferably, there is. When the content is 20% by weight or more, the solubility or the swelling rate change due to the change in the surface layer of the heat-sensitive layer can be maintained. On the other hand, when the content is 95% by weight or less, laser light is relatively absorbed to generate heat. By maintaining the amount of the compound, the heat generation by laser irradiation does not cause a problem.

The heat-sensitive layer of the direct-drawing lithographic printing plate precursor that can be preferably used in the present invention preferably contains a compound that absorbs laser light and generates heat.

Examples of the compound that absorbs laser light and generates heat include black pigments such as carbon black, titanium black, aniline black, and cyanine black, phthalocyanine, naphthalocyanine-based green pigments, carbon graphite, diamine-based metal complexes, and dithiol. Metal complexes, phenol thiol metal complexes, mercaptophenol metal complexes, inorganic compounds containing water of crystallization, copper sulfate, chromium sulfide, silicate compounds, titanium oxide, vanadium oxide, manganese oxide, iron oxide, cobalt oxide, tungsten oxide And hydroxides and sulfates of these metals.

In addition, dyes that absorb infrared or near infrared rays, particularly dyes, are preferably used. Particularly preferred dyes include cyanine-based, phthalocyanine-based, naphthalocyanine-based, dithiol metal complex-based, piazurenium-based,
Squarylium-based, croconium-based, azo-based disperse dyes,
Bisazo type, bisazostilbene type, naphthoquinone type,
Anthraquinone, perylene, polymethine, indoaniline metal complex dyes, intermolecular CT, benzothiopyran, spiropyran, nigrosine, thioindigo, nitroso, quinoline, fulgide dyes, especially dyes, etc. .

Of these, carbon black is particularly preferable in that it absorbs laser light over a wide wavelength range, and cyanine, polymethine, and naphthalocyanine dyes are particularly preferable in terms of laser light absorption.

The content of these compounds is preferably from 1 to 40% by weight, more preferably from 5 to 25% by weight, based on the total heat-sensitive layer composition. When the content is 1% by weight or more, the laser light can be efficiently absorbed. When the content is 40% by weight or less, the physical properties of the heat-sensitive layer are not adversely affected.

In addition, the heat-sensitive layer may contain a binder polymer, a surfactant and various additives. The content of these binders is 5 to 7 with respect to the total thermosensitive layer composition.
0% by weight is preferable, and 10 to 50% by weight is more preferable. When the content is 5% or more, there is no problem in printing durability and coating properties of the coating solution, and when the content is 70% by weight or less, there is no adverse effect on image reproducibility.

The transmittance of the heat-sensitive layer of the present invention to light having the same wavelength as the irradiation laser light is preferably less than 20%, and more preferably less than 10%. By setting the transmittance of the heat-sensitive layer to less than 20%, light transmitted through the entire heat-sensitive layer can be reduced, and an effective reaction can be performed on the surface layer of the heat-sensitive layer. Further, since light transmitted through the entire heat-sensitive layer can be reduced, unnecessary reaction of the heat-sensitive layer due to reflection of energy from below the heat-sensitive layer can be suppressed.

The thickness of the heat-sensitive layer is 0.1 to 1 as a coating layer.
0 g / m ² is preferable in terms of printing durability of the printing plate and excellent productivity because the diluting solvent is easily evaporated, and 1 to 5 g / m ^2.
Is more preferred.

Further, the direct-printing printing plate precursor of the present invention preferably has a silicone rubber layer as an ink repellent layer on the heat-sensitive layer. As the silicone rubber layer, any of an addition polymerization type and a condensation polymerization type may be used.
An addition polymerization type silicone rubber layer is preferable from the viewpoint of handleability and ink repellency.

The components constituting the addition polymerization type silicone rubber layer include vinyl group-containing polydimethylsiloxane,
Examples include SiH group-containing polysiloxanes, and those containing a reaction inhibitor and a curing catalyst for the purpose of controlling the curing rate.

The components constituting the silicone rubber layer of the condensation polymerization type include a hydroxyl group-containing polydimethylsiloxane, a crosslinking agent (deacetic acid type, deoxime type, dealcohol type, deamine type, deacetone type, deamide type, Deaminoxy type, etc.), and those containing a curing catalyst.

The thickness of these silicone rubber layers is 0.5 to
Preferably 20 g / m ^2, more preferably 1 to 4 g / m ^2. When the film thickness is 0.5 g / m ² or more, the ink repellency, scratch resistance, and printing durability of the printing plate can be stably exhibited, and when the film thickness is 20 g / m ² or less, the developing property,
Good ink mileage can be maintained.

Further, a protective film may be laminated or a protective layer may be formed on the direct drawing type lithographic printing plate precursor used in the present invention for the purpose of protecting the ink repellent layer. Examples of the protective film include a polyester film and a polypropylene film.

Next, a method for producing a direct drawing type waterless planographic printing plate will be described.

The method for producing a direct-drawing waterless lithographic printing plate of the present invention comprises: (1) a step of causing the surface layer of the heat-sensitive layer to react by laser irradiation, (2) a step of treating with an organic solvent, and (3) the presence of water. Removing the ink-repellent layer in the laser-irradiated part by brush rubbing.

Light sources used for laser irradiation include:
A laser having an emission wavelength region in the range of 300 nm to 1500 nm is used, and a semiconductor laser or a YAG laser having an emission wavelength region near the near infrared region is preferably used from the viewpoint of handleability of the plate material in a bright room. Can be Specifically, laser light having a wavelength of 830 nm or 1064 nm is preferably used for plate making.

The laser irradiation is carried out after peeling off the protective film from the direct drawing type waterless planographic printing plate precursor or from above the protective film.

When laser irradiation is performed, the compound that absorbs light in the thermosensitive layer and generates heat absorbs the laser light and generates heat. At this time, since the transmittance of the heat-sensitive layer is low, the laser light is more absorbed near the surface layer of the heat-sensitive layer, and therefore, the temperature tends to be higher near the surface layer of the heat-sensitive layer. Therefore, by adjusting the amount of laser light irradiation, it is possible to cause a reaction only in the vicinity of the surface layer of the heat-sensitive layer. As a result, only the surface layer of the heat-sensitive layer in the laser irradiation part dissolves or swells.

The compound having the structure represented by the general formula (I) reacts by the action of heat as described above, and changes the solubility and swelling ratio of the heat-sensitive layer. As a result, the treatment with the organic solvent dissolves or swells the above-mentioned compound in the surface layer of the heat-sensitive layer, thereby weakening the adhesive force with the silicone rubber layer.

As the organic solvent used in the treatment, a glycol compound or a glycol ether compound represented by the following general formula (IX) is preferable.

R ² O— (CHR ¹ —CH ₂ —O—) _n R ³ (IX) (wherein, R ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ² and R ³ are hydrogen atoms Or 1 to 15 carbon atoms
Wherein n is an integer of 1 to 12. Examples of particularly preferred specific compounds include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polyoxypropylene glycol (Mw: 200), and polyoxypropylene glycol monobutyl ether. (Mw: 120
0), tetraethylene glycol mono-2-ethylhexyl ether, diethylene glycol mono-2-ethylhexyl ether, and the like.

The treatment liquid preferably contains an alkali or an amine compound. Examples of particularly preferred specific compounds include diethylene glycol amine, N- (β-aminoethyl) aminoethanol, diethanolamine, N-methyldiethanolamine, morpholine, N-methylmorpholine, and N- (3-aminopropyl) morpholine. No. These amine compounds are preferably contained in the treatment liquid in an amount of 0.1 to 30% by weight, more preferably 0.5 to 20% by weight.

Further, water, alcohols, carboxylic acids, and a surfactant may be added to the above-mentioned treatment liquid, if necessary.

Although the surface layer of the heat-sensitive layer in the laser-irradiated portion is dissolved or swelled by such a treatment liquid, the temperature of the treatment liquid is preferably kept constant in order to stably dissolve or swell. The appropriate temperature of the processing solution depends on the processing time, but is preferably 10 to 50 from the viewpoint of easy retention.
C, more preferably 35-45C.

The direct-drawing waterless lithographic printing plate precursor obtained by dissolving or swelling the surface of the heat-sensitive layer of the laser-irradiated portion treated with an organic solvent as described above is rubbed with a brush in the presence of water to thereby form a laser-irradiated portion. Remove the ink repellent layer.

The production of a printing plate including the above steps is as follows.
A manual method may be used, but “TWL-11” manufactured by Toray Industries, Inc.
60, "TWL-650", "TWL-860", Japanese Patent No. 2864907, and
It is preferable to use an automatic developing machine for a waterless lithographic printing plate as disclosed in JP-A-8842, JP-A-6-258842, JP-A-6-258844, JP-A-7-92692 and the like. .

As a brush, a brush roller is generally used in which a brush material having a diameter of 20 to 500 μm is implanted in a groove shape such as metal or plastic in a row, and the brush material is attached to a core. The brush material may be radially implanted in the core, or the brush material implanted in a base material such as a plastic sheet or cloth may be wound around the core.

The brush material is at least one selected from the group consisting of polyvinyl chloride, polyamide, polyethylene terephthalate, polybutylene terephthalate and polypropylene, so that the ink repellent layer of the printing plate is not damaged by the brush, and the brush is not damaged. Insufficient removal of the ink repellent layer at the laser irradiation part due to insufficient power can be prevented.

Further, the number of rotations of the brush roller is 10 to 10
00 rpm, preferably 200 to 600 rpm.
In addition, by rotating the brush roller and reciprocating in the axial direction, the effect of removing the ink repellent layer at the laser irradiation portion is improved. As the rotation direction of the brush roller,
It is important from the viewpoint of removing the ink repellent layer of the laser irradiation part to have both the one in the same direction as the transport direction of the printing plate and the one in the opposite direction.

The direct-drawing waterless planographic printing plate thus obtained was dyed with a heat-sensitive layer in the laser-irradiated portion serving as an image portion to give a contrast between the image portion and the non-image portion.
Enhancing image visibility is also preferably performed. As the dye used for dyeing, a water-soluble basic dye and an acid dye are particularly preferably used. Specifically, crystal violet, ethyl violet, Victoria Pure Blue, Victoria Blue, methyl violet, Brilli
ant Basic Cyanine 6GH and the like, but are not limited thereto.

The direct-drawing waterless planographic printing plate thus dyed may be further washed with water.

Further, by providing a heat-sensitive layer containing a compound having a structure represented by the general formula (I) on an aluminum substrate which has been subjected to a hydrophilic treatment such as anodizing treatment, a direct drawing type lithographic printing with water is provided. You can get the original plate.

The heat-sensitive layer is reacted by laser irradiation,
By using an alkali developer or the like, the heat-sensitive layer at the laser irradiation part is removed. In this case, it is necessary to react the entire heat-sensitive layer. Therefore, it is preferable to design the heat-sensitive layer so that the transmittance of the heat-sensitive layer is high and the laser light is transmitted as much as possible through the entire heat-sensitive layer.

As the alkali developer used for the development, those containing an alkali such as sodium hydroxide, potassium hydroxide and sodium metasilicate, a surfactant and the like can be used.

[0069]

The present invention will be described in more detail with reference to the following examples.

Example 1 << Synthesis of Compound 1 Having a Structure Represented by General Formula (I) >> In a 100 ml eggplant-shaped flask, "Sumilite Resin" PR50622 (phenol novolak resin, Sumitomo Durez Co., Ltd.) )), Weigh out 5.5 g, and further dry tetrahydrofuran 6 with molecular sieve 4A.
5 g were poured. This was stirred at 30 ° C. using a stirrer to prepare a phenol novolak resin in tetrahydrofuran solution (pale yellow). To this solution was added "Orgatics" TC-125 (manufactured by Matsumoto Pharmaceutical Co., Ltd., titanium di-n-butoxide (bis-2,4)).
2 g of an acetylacetone solution of (pentanedionate): yellow) was added dropwise using a dropping funnel, and the solution turned brown. The solution was further stirred for 1 hour at 30 ° C. to obtain a solution of compound 1 having a structure represented by the general formula (I).

When the UV spectrum of the obtained solution of the compound (I) was measured, it was found that the absorption was not observed in the phenol novolak resin solution or the titanium di-n-butoxide (bis-2,4-pentanedionate) solution. Is 36
It was observed near 0 nm.

Further, a solution of the compound (I) was applied on an aluminum substrate and dried at 130 ° C. for 60 seconds. Observation of the obtained coating film by an infrared absorption spectrum revealed that absorption derived from bis-2,4-pentanedionate was observed at 1025 cm-1 in addition to absorption derived from the novolak resin.
When a part of this coating film was subjected to TG-MAS,
At around 150 ° C., the generation of 2,4-pentanedionate was measured. From these results, it was confirmed that Compound 1 was expected to have the structural formula as shown in FIG.

<< Preparation of Direct-Drawing Lithographic Printing Plate Precursor 1 >> A solution having the following composition was applied on a degreased aluminum plate having a thickness of 0.24 mm using a bar coater, and then heated to 130 ° C. × 60.
After drying for ² seconds, a heat-sensitive layer of 1.0 g / m ² was provided. <Thermal layer 1> (a) "KAYASORB" IR-820B (manufactured by Nippon Kayaku Co., Ltd.): 11 parts by weight (b) Solution of compound 1 having a structure represented by the general formula (I): 780 parts by weight (C) "SAMPLEN" T1331D (polyurethane, manufactured by Sanyo Chemical Industries, Ltd.): 10 parts by weight (solid content of 10%)
(D) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxypropyltrimethoxysilane:
1/3/1 molar ratio adduct: 10 parts by weight Then, the following silicone rubber layer was dried to a thickness of 2.0 μm,
The drying condition was 125 ° C. × 1 minute, and the coating was performed with a bar coater.

<Silicone Rubber Layer 1> (a) α, ω-divinylpolydimethylsiloxane (molecular weight: about 60,000): 100 parts by weight (b) “HMS-501” (manufactured by Chisso Corp. (Hydrogensiloxane) (dimethylsiloxane) copolymer Number of SiH groups / molecular weight = 0.69 mol
l / g): 7 parts by weight (c) Vinyl tri (methylethyl ketoxime) silane: 3 parts by weight (d) "SRX-212" (Toray Dow Corning Silicone Co., Ltd., platinum catalyst): 5 parts by weight (e) " Isopar E (manufactured by Esso Chemical Co., Ltd.): 10
00 parts by weight On the laminate obtained as described above, an 8 μm thick polypropylene film “Trefane” BO (Toray Industries, Inc.)
Was laminated using a calendar roller to obtain a direct-lithographic printing plate precursor 1.

<< Manufacture of Lithographic Printing Plate >> The direct-drawing lithographic printing plate precursor 1 obtained as described above was peeled off from the cover film and then subjected to “GX-3600” (plate making machine, Toray Industries, Ltd.).
And irradiated with a laser using a semiconductor laser (wavelength: 830 nm) (irradiation energy: 175 mJ / c).
m ^2, 2400dpi, 175lpi).

Thereafter, using an automatic developing machine “TWL-860KII” (manufactured by Toray Industries, Inc.) for a waterless lithographic printing plate, the following processing solution was placed in a first tank of the automatic developing machine, and a second tank and a third tank were prepared. The tank was filled with water to produce a direct-drawing lithographic printing plate.

The treatment liquid was composed of 80 parts by weight of diethylene glycol, 15 parts by weight of diethylene glycol amine,
A 40% aqueous solution of sodium ethylhexyl sulfate (anionic surfactant): 1 part by weight, water: 4 parts by weight, the temperature was 40 ° C., and the treatment time was 30 seconds. Water was used as the liquid in the brush rubbing step (the step of rotating in the same direction as the transport direction of the printing plate, and the step of rotating in the reverse direction). The water temperature was 25 ° C.

As a result, a direct drawing type lithographic printing plate was obtained in which the silicone rubber layer in the portion irradiated with the laser beam was removed.

<< Evaluation of Image Reproducibility >> The resulting printing plate was observed with a 25-power loupe to evaluate the image reproducibility of the printing plate. The reproducibility was 1 to 99%. .

Further, the printing plate was converted to a sheet-fed offset printing press “Sprint 25” (manufactured by Komori Corporation).
Lithographic ink "Dryocolor NS"
I ", printed on high-quality paper (62.5 kg / chrysanthemum) using indigo (manufactured by Dainippon Ink and Chemicals, Inc.), and evaluated for image reproducibility as a printed material. there were.

Comparative Example 1 Instead of using Compound 1 in Example 1, the same amount of phenol novolak resin “Sumilite Resin” PR50622 (Sumitomo Durez Co., Ltd.)
Printing Plate Precursor 2 was produced using the same method as described in Example 1. As a result, the silicone rubber layer was peeled off over the entire surface.

The results show that the solvent-resistant layer of the heat-sensitive layer did not exhibit solvent resistance because it did not contain the compound of the present invention, so that the upper silicone rubber layer was peeled off.

[Comparative Example 2] A printing plate precursor 3 was prepared in the same manner as in Example 1 except that the composition of the heat-sensitive layer was changed as follows, and evaluated in the same manner.

<Thermal Sensitive Layer 2> (a) “KAYASORB” IR-820B (manufactured by Nippon Kayaku Co., Ltd.): 11 parts by weight (b) “Orgatics” TC-125 (manufactured by Matsumoto Pharmaceutical Co., Ltd., -N-butoxide (bis-2,4
-Pentandionate solution in acetylacetone): 9
Parts by weight (calculated as solid content concentration of 40% by weight; solids content of 9 parts by weight) (c) "SAMPLEN" T1331D (polyurethane, manufactured by Sanyo Chemical Industries, Ltd.): 70 parts by weight (solid content of 10 parts)
(D) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxypropyltrimethoxysilane:
1/3/1 molar ratio adduct: 10 parts by weight (e) Tetrahydrofuran: 800 parts by weight (f) Dimethylformamide: 100 parts by weight As a result, the silicone rubber layer was peeled over the entire surface.

The results show that the solvent-resistant layer of the heat-sensitive layer did not exhibit solvent resistance because it did not contain the compound of the present invention, so that the upper silicone rubber layer was peeled off.

[Comparative Example 3] A printing plate precursor 4 was prepared in the same manner as in Example 1 except that the composition of the heat-sensitive layer was changed as follows, and evaluated in the same manner.

<Thermal Sensitive Layer 3> (a) "KAYASORB" IR-820B (manufactured by Nippon Kayaku Co., Ltd.): 11 parts by weight (b) Iron (III) acetylacetonate: 15 parts by weight (c) "Sumilite" Resin "PR50622 (phenol novolak resin, manufactured by Sumitomo Durez Co., Ltd.): 60 parts by weight (d)" SAMPLEN "T1331D (polyurethane, manufactured by Sanyo Chemical Industries, Ltd.): 10 parts by weight (solid content: 10 parts)
(Parts by weight) (e) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxypropyltrimethoxysilane:
1/3/1 molar ratio adduct: 10 parts by weight (f) Tetrahydrofuran: 800 parts by weight (g) Dimethylformamide: 100 parts by weight As a result, only the printing plate with poor image reproducibility in which the silicone rubber layer at minute points was peeled off was obtained. Could not be obtained.

The results show that the heat-sensitive layer contains the phenol novolak resin and the organometallic compound iron (III) acetylacetonate, but does not contain the compound having the structure represented by the general formula (I). Therefore, the solvent resistance of the heat-sensitive layer is not sufficient, and the image reproducibility is also poor.

[0089]

[Table 1]

[0090]

According to the present invention, a direct drawing type lithographic printing plate having good image reproducibility can be obtained.

[Brief description of the drawings]

FIG. 1 shows an example of a compound represented by formula (III), which is a particularly preferred structure in the present invention.

Continued on front page F-term (reference) 2H025 AA04 AB04 AC08 BC64 CA41 CB10 CB17 CB22 CB28 CB29 CB41 CB43 CB45 CC12 CC13 CC20 DA37 FA17 2H096 AA13 BA09 EA23 GA08 GA27 2H114 AA05 AA22 AA24 AA30 DA03 DA03 DA03 DA56 DA59 DA60 DA62 EA01 EA02 EA08

Claims (6)

[Claims] 1. A direct-drawing lithographic printing plate precursor having at least a heat-sensitive layer on a substrate, wherein the heat-sensitive layer contains a compound having a structure represented by the following general formula (I). Direct drawing type lithographic printing plate precursor. M (A) n (B) m (C) l (I) (M is a metal atom or an organic component, A is an organic polymer component,
B is an organic low-molecular component, C is an organic low-molecular component, n and m are integers of 1 or more, and l is 0 or an integer of 1 or more. ) 2. The compound having a structure represented by the general formula (I) is selected from compounds having a structure represented by the following general formulas (II) to (VIII). The lithographic printing plate precursor according to claim 1. M (A) ₂ (B) ₁ (II) M (A) ₂ (B) ₂ (III) M (A) ₂ (B) ₁ (C) ₁ (IV) M (A) ₃ (B) ₁ ( V) M (A) ₂ (B) ₃ (VI) M (A) ₃ (B) ₂ (VII) M (A) ₄ (B) ₁ (VIII) (M is a metal atom, A is an organic polymer component) , B and C are organic low molecular components.) 3. A compound having a structure represented by the above general formula (I), wherein M is Al, Ti, Mn, Fe, Co,
4. A material selected from the group consisting of Ni, Cu, Zn, Ge, In, Sn, Zr, and Hf.
2. The direct-lithographic printing plate precursor according to any one of 2. 4. A compound having a structure represented by the general formula (I), wherein the organic polymer component A is a novolak resin, a resole resin, a homo- or copolymer of hydroxystyrene, a phenol-furfural resin, a furan resin. ,
The lithographic printing plate precursor according to any one of claims 1 to 3, wherein the lithographic printing plate precursor is a member selected from the group consisting of an unsaturated polyester resin, a hydroxyl group-containing polyurethane resin, and a rosin-modified maleic acid resin. 5. The compound according to claim 1, wherein in the compound having the structure represented by the general formula (I), the low-molecular organic component B is β-diketone. A lithographic printing plate precursor. 6. A method for producing a direct drawing type waterless lithographic printing plate having a thermosensitive layer containing at least a compound having a structure represented by the following general formula (I) and an ink repellent layer on a substrate in this order. (1) a step of reacting the surface layer of the heat-sensitive layer by laser irradiation, (2) a step of treating with an organic solvent, (3)
Removing the ink-repellent layer of the laser-irradiated portion by brush rubbing in the presence of water. M (A) n (B) m (C) l (I) (M is a metal atom or an organic component, A is an organic polymer component,
B is an organic low-molecular component, C is an organic low-molecular component, n and m are integers of 1 or more, and l is 0 or an integer of 1 or more. )