JP2002244279A - Original plate of direct pattern forming planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a direct pattern forming planographic printing plate having good image reproducibility and good plate inspectability. SOLUTION: The original plate of the direct pattern forming planographic printing plate has at least a heat sensitive layer and an ink-repellent layer in this order on a substrate and a dye is contained in the ink-repellent layer.

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 the advantage that it can be handled in a bright room, and due to the rapid progress of the semiconductor laser as a light source, it has recently attracted much attention,
It is said that it will become the mainstream in the future.

As a method for producing a lithographic printing plate in a heat mode, particularly a waterless lithographic printing plate which does not require dampening water for printing, the following proposals have been made so far, but there are various problems. Was.

For example, US Pat. No. 5,339,737, JP-A-6-55723, US Pat.
580, JP-A-6-186750, JP-A-6-199064, JP-A-9-146264, JP-A-9-146265, JP-A-9-23
6927, JP-A-9-244228, JP-A-10-250253, U.S. Pat.
No. 2, U.S. Pat. No. 5,649,486, and U.S. Pat. No. 5,570,636 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 the thermal destruction method mainly uses carbon black as a laser light absorbing compound and nitrocellulose as a thermal decomposition compound. When the laser is irradiated, the laser light is absorbed by the carbon black and converted into heat energy. When the heat-sensitive layer is destroyed by the heat, the silicone rubber layer on the surface is peeled off at the same time, and an ink-coated portion is formed. However, these printing plates have the problem that the image is formed by destroying the heat-sensitive layer, so that the depth of the cells in the image area becomes deep, the ink adhesion at fine halftone dots is poor, and the ink mileage is poor. was there. Furthermore, by-products such as gas may be generated by ablation, which may adversely affect the optical system.Furthermore, it is necessary to remove ablation residues, and it is difficult to reproduce minute halftone dots. Had a problem. In addition, there is a problem that the sensitivity of the printing plate is basically low and a high laser light intensity is required to destroy the heat-sensitive layer.

Japanese Unexamined Patent Publication 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. Since two steps, a light irradiation step and a heating step, are required, the steps are complicated, and there is a problem inherent in peeling development that reproducibility of fine halftone dots is poor.

For the purpose of solving such a problem, there has been developed a printing plate of a type in which a heat-sensitive layer of a laser-irradiated portion remains after laser irradiation and development. For example, JP-A-11-2
No. 21977, JP-A-11-334237,
JP-A-11-227355 and the like. By these inventions, having sufficient sensitivity in practical use, without adversely affecting the optical system, having excellent image reproducibility, high ink repulsion, very good performance such as stable developability,
A direct drawing type waterless lithographic printing plate precursor capable of producing a high quality printed matter which is an original feature of the waterless lithographic printing plate was obtained.
However, since the heat-sensitive layer remains regardless of the laser-irradiated part and non-irradiated part, it is difficult to obtain the contrast between the laser-irradiated part and the non-irradiated part. It was difficult to perform on-press inspection on the way.

As a method for obtaining a contrast between a laser-irradiated portion and a non-laser-irradiated portion, see Japanese Patent Application Laid-Open No. H11-190903.
In Japanese Patent Application Laid-Open Publication No. H10-163, a method of adding a leuco dye or the like to a heat-sensitive layer is proposed. However, the contrast that is a problem in this proposal relates to the print-out inspection property after laser irradiation and before development, and the printing plate also has a heat-sensitive layer on the anodic oxide layer, and the laser irradiation part is developed by development. The printing plate of the type in which the heat-sensitive layer is removed. Therefore, no effect is obtained for a printing plate in which the heat-sensitive layer remains.

Japanese Patent Application Laid-Open No. Hei 10-250253 proposes to increase the contrast between an image area and a non-image area by including a compound which dissolves or swells in water in a heat-sensitive layer. The present invention relates to a printing plate of a type in which the layer is completely removed, and no effect is obtained for a printing plate of a type in which the heat-sensitive layer remains.

US Pat. No. 5,649,486 also proposes a method for improving the contrast between an image area and a non-image area, but basically relates to a printing plate of a type in which a heat-sensitive layer is completely removed by ablation. No mention was made of a printing plate of the type in which the heat-sensitive layer remained, and it was ineffective.

Japanese Patent Application Laid-Open No. H11-227353 proposes that a printing plate in which a heat-sensitive layer remains remains, after development, an image area is dyed. However, this method requires an extra dyeing step, which increases the cost of an automatic developing machine, and has a problem of controlling a dyeing solution. Further, the contrast with the ink on the printing press was not improved, which was a practical problem.

[0013]

SUMMARY OF THE INVENTION The object of the present invention is to improve the drawbacks of the prior art by improving the image reproducibility and the direct drawing type with good plate inspection from the printing plate preparation to before printing. The planographic printing plate precursor is provided.

[0014]

Means for Solving the Problems A method of manufacturing a direct-drawing lithographic printing plate according to the present invention mainly has the following constitution in order to solve the above-mentioned problems. That is, "a direct-drawing lithographic printing plate having at least a heat-sensitive layer and an ink-repellent layer on a substrate in this order, wherein the ink-repellent layer contains a dye, ".

[0015]

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

The direct drawing type lithographic printing plate precursor according to the present invention has a structure in which at least a heat-sensitive layer and an ink repellent layer are provided in this order on a substrate, and the heat-sensitive layer of the laser irradiated portion remains, and the ink repellent layer is not formed. It is a direct-lithographic printing plate precursor to be removed.
A printing plate precursor that has a heat-sensitive layer on an ink repellent layer such as an anodized layer and forms an ink-coated portion and an ink repellent portion by removing a part of the heat-sensitive layer is not in the scope of the present invention.

The most important feature of the present invention is that the ink repellent layer contains a dye.

The dyes include direct dyes, acid dyes, basic dyes, mordant dyes, acid mordant dyes, sulfur dyes, sulfur vat dyes, vat dyes, soluble vat dyes, azoic dyes, and the like. Disperse dyes, reactive dyes, oxidation dyes and the like can be mentioned, and any type of dye can be used.

From the classification by chemical structure, azo dyes such as monoazo dye, polyazo dye, metal complex salt azo dye, pyralozone azo dye, stilbene azo dye and thiazole azo dye, anthraquinone derivatives such as anthraquinone derivatives and anthrone derivatives, and indigo Derivatives, indigoid dyes such as thioindigo derivatives, phthalocyanine dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, carbonium dyes such as acridine dyes, azine dyes, oxazine dyes, quinone imine dyes such as thiazine dyes, cyanine dyes, Polymethine dyes, methine dyes such as azomethine dyes, etc., quinoline dyes, nitro dyes, nitroso dyes,
Examples thereof include benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes, and perinone dyes, but are not particularly limited to the chemical structure, and any type of dye can be used.

In the present invention, the wavelength (λmax) at which the dye exhibits the maximum absorbance is preferably in the range of 400 to 700 nm. The maximum value of absorbance is 400 to 700 nm
The contrast between the image area and the non-image area is obtained from the relationship with the absorbance characteristic of the heat-sensitive layer described below,
Good plate inspection is obtained.

Further, as the dye of the present invention, a dye having good compatibility with the silicone rubber layer component preferably used as the ink repellent layer is preferable, and from that viewpoint, an oil-soluble dye is preferable. Further, since the ink repellent layer is stably present after the development, it preferably has a functional group capable of interacting with the components of the ink repellent layer. Examples of the functional group include a carbon-carbon unsaturated double bond such as a vinyl group, an allyl group, a hexenyl group, an acryl group, and a methacryl group, a hydroxyl group, a carboxyl group, a mercapto group, an amino group, a silyl group, and a carbonyl group. , A vinyl group and a hydroxyl group are preferred.

Specific examples of such particularly preferred commercially available dyes include Orient Oil Brown BB
(CI12150), Balifast Red # 3304
(CI12715), Balifast Red # 3305
(CI12716), varifast red # 2303,
Orient Oil Red RR (CI26105), Orient Oil Red 5B (CI26125), Orient Oil Red # 330 (CI60505), Orient Oil Scarlet # 308 (CI21260), Orient Oil Pink OP, Orient Oil Pink #
312, Orient Oil Violet # 730 (CI
60725), Orient Oil Violet # 732
(CI61705), Orient Oil Blue BO (C
I74350), Orient Oil Green BG, Orient Oil Yellow # 101, Orient Oil Yellow # 130, Orient Oil Black BY, Oil Black BS, Oil Black T-550 (all manufactured by Orient Chemical Co., Ltd.), Eizen Spiron Orange GRH, Eisen Spiron Red GEH, Eisen Spiron Red GEH Special, Eisen Spiron Red BEH, Eisen Spiron Red BEH Special, Eisen Spiron Violet RH, Eisen Spiron Violet RH Special, Eisen Spiron Violet ECH, Eisen Spiron Blue GNH, Aizen Spiron Blue E2BH, Aizen Spiron Blue 2B
NH, Eisen Spiron Green 3GNH Special,
Aizen Spiron Fairy Red BH, Aizen Spiron Pink BH, Aizen Metalon Red HGRS (all manufactured by Hodogaya Chemical Co., Ltd.), Oil Orange # 8
16, oil red # 809, oil pink # 427,
Oil Violet # 1076, Oil Violet R
(CI61100), Oil Brown # 1033, Oil Green # 890, Oil Blue # 15 (CI743
50), Oil Blue # 456 (above, Yamamoto Kasei Co., Ltd.)
Kayaset Red AG, Kayaset Orange A
N, Kayaset Red 130, Kayaset Red B, Kayaset Blue FR (all manufactured by Nippon Kayaku Co., Ltd.), Crystal Violet (CI42535), Rhodamine B
(CI45170B), rhodamine 6G, malachite green (CI42000), methylene blue (CI52)
015) and the like, but are not limited thereto.

Such a dye is preferably added to the ink repellent layer as a solid content of 0.1 to 30% by weight, more preferably 1 to 10% by weight. The reason for this is that by adding 0.1% by weight or more, good plate inspection properties can be imparted, and by setting the content to 30% by weight or less, the ink rebound is not reduced.

The ink repellent layer of the direct-drawing lithographic printing plate of the present invention includes a hydrophilic layer made of a hydrophilic polymer, a hydrophilic swelling layer, a fluororesin layer, a silicone rubber layer, and the like. It is preferably a layer. As the silicone rubber layer, any of an addition polymerization type silicone rubber layer and a condensation polymerization type silicone rubber layer can be used, but an addition polymerization type silicone rubber layer is preferable. 1) Addition polymerization type silicone rubber layer The components constituting the addition type silicone rubber layer include vinyl group-containing polydimethylsiloxane and Si as a crosslinking agent.
It contains an H group-containing polysiloxane and a curing catalyst as a main component, and further contains a reaction inhibitor and the like for the purpose of controlling the curing rate.

Examples of the polysiloxane having a SiH group include polysiloxanes having a SiH group in a molecular chain or at a terminal, and include, for example, compounds represented by the following general formula.

[0026]

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[0027]

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[0028]

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[0029]

Embedded image (In the above formulas (I to IV), n represents an integer of 1 or more;
Represents an integer of 1 or more. The amount of SiH groups in the compound having SiH groups is preferably two or more, more preferably three or more in one molecule.

The amount of the compound having a SiH group is 0.1 to 30% by weight based on the solid content of the silicone rubber layer.
And more preferably 1 to 15% by weight. In terms of the quantitative ratio of the compound having the SiH group to the vinyl group-containing polydimethylsiloxane, the molar ratio of SiH group / polydimethylsiloxane carbon-carbon double bond is 1.5 to 40. And more preferably 3 to 20. When the molar ratio is less than 1.5, the curing of the silicone rubber layer may be insufficient. On the other hand, when the molar ratio is more than 40, the physical properties of the rubber become fragile and adversely affect the scratch resistance of the printing plate. It is because it becomes easy to give.

The vinyl group-containing polydimethylsiloxane is
It has a vinyl group at the molecular terminal and / or in the main chain, and has a structure represented by the following general formula (V).

[0032]

Embedded image (Wherein, m represents an integer of 2 or more, and R ¹ and R ^{2 each} have 1 carbon atom.
~ 50 substituted or unsubstituted alkyl groups, having 2 to 2 carbon atoms
50 substituted or unsubstituted alkenyl groups, having 4 to 4 carbon atoms
At least one selected from the group of 50 substituted or unsubstituted aryl groups is shown, and may be the same or different. It is preferred from the viewpoint of the ink repellency of the printing plate that 50% or more, more preferably 80% or more of R ¹ and R ^{2 in} the formula are methyl groups. The molecular weight of the polydimethylsiloxane may be in the range of thousands to hundreds of thousands, but from the viewpoints of handleability, ink repellency of the obtained printing plate, scratch resistance, and the like, the weight average molecular weight is 10,000 to 200,000. , And 30,000-15
It is preferable to use ten thousand. It is also preferable to use a mixture of 30,000 to 150,000 and a high molecular weight gum having a weight average molecular weight of about 500,000.

The curing catalyst is a Group III transition metal compound, preferably a platinum compound. Specifically, platinum alone, platinum chloride, chloroplatinic acid, olefin-coordinated platinum, an alcohol-modified complex of platinum, and methyl methyl of platinum A vinyl polysiloxane complex can be given as an example. The amount of such a curing catalyst is 0.01 to 20% by weight, preferably 0.1 to 10% by weight as a solid content in the silicone rubber layer. When the amount of the catalyst to be added is 0.01% by weight or more, the curing of the silicone rubber layer becomes sufficient, and there is no problem in the adhesion to the heat-sensitive layer. On the other hand, when the content is 20% by weight or less, the pot life of the silicone rubber layer solution is not adversely affected. In terms of the amount of metal such as platinum in the silicone rubber layer composition, 10 to 10
It is preferably 00 ppm, preferably 100 to 500 ppm.

Examples of the reaction inhibitor include a nitrogen-containing compound, a phosphorus compound, and an unsaturated alcohol, and an acetylene group-containing alcohol is preferably used.
The preferable addition amount of the reaction inhibitor is 0.01 to 10% by weight in the silicone rubber composition, more preferably 1 to 10% by weight.
~ 5% by weight.

In addition to these compositions, hydrolyzable functional group-containing silanes or siloxanes, known silane coupling agents, titanate-based coupling agents, aluminum-based coupling agents, etc. for the purpose of improving the adhesiveness may be used. May be contained. As the silane coupling agent, alkoxysilanes, acetoxysilanes, ketoximine silanes and the like are preferable, and those having a vinyl group and ketoximine silanes are particularly preferable.

When ketoximine silanes are used,
It is particularly preferable because it is a nitrogen-containing compound and thus functions as a reaction inhibitor as well as functions as an adhesion-imparting agent.

The addition amount of such a compound is preferably 0.5 to 20% by weight, more preferably 2 to 5% by weight, based on the total composition of the silicone rubber layer.
When the content is more than 0.5% by weight, the effect of exhibiting the adhesiveness is exerted. On the other hand, when the content is 20% by weight or less, sufficient ink resilience can be exhibited. 2) Condensation polymerization type silicone rubber layer The components constituting the condensation polymerization type silicone rubber layer include a hydroxyl group-containing polydimethylsiloxane, a cross-linking agent (deacetic acid type, deoxime type, dealcohol type, deamine type, deaminating type). Acetone type, deamidation type, deaminoxy type, etc.), and curing catalyst.

Examples of the cross-linking agent include acetoxysilanes, alkoxysilanes, ketoximine silanes, and allyloxysilanes represented by the following general formula (VI). (R ³ ) _4-n SiX _n (VI) (wherein, n represents an integer of 2 to 4, and R ³ represents a substituted or unsubstituted alkyl group, alkenyl group, aryl group having 1 or more carbon atoms, or X represents a combined group of
Represents a functional group selected from a halogen atom, an alkoxy group, an acyloxy group, a ketoximine group, an aminooxy group, an amide group, and an alkenyloxy group. Specific preferred compounds include, but are not limited to, methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane, vinyltri (methylethylketoximine) silane, tetra (methylethylketoximine) silane, and the like. Not something.

The amount of the crosslinking agent represented by the general formula (VI) is preferably from 0.1 to 30% by weight, more preferably from 1 to 15% by weight, based on the total composition of the silicone rubber layer. Speaking of the quantitative ratio with polydimethylsiloxane, the molar ratio of functional group X / hydroxyl group of polydimethylsiloxane is preferably 1.5 to 10.0. When the molar ratio is 1.5 or more, there is no risk of gelation of the silicone rubber layer solution, and when the molar ratio is 10.0 or less, the physical properties of the rubber become brittle and the printing plate has scratch resistance. There is no adverse effect.

The hydroxyl group of the hydroxyl group-containing polydimethylsiloxane can be located at the molecular terminal and / or in the main chain, but those preferably used are those having a hydroxyl group at the molecular weight terminal. A molecular weight of several thousand to several hundred thousand can be used, but from the viewpoints of handleability, ink repellency and scratch resistance of the obtained printing plate, the weight average molecular weight is 1
It is preferable to use a material of 10,000 to 200,000, more preferably 30,000 to 150,000.

Examples of the curing catalyst include acids, alkalis, amines, metal alkoxides, metal diketenates, metal organic acid salts, and the like. Among them, it is preferable to add an organic acid salt of a metal, particularly preferably an organic acid salt of a metal selected from tin, lead, zinc, iron, cobalt, calcium, and manganese. Specific examples of such compounds include dibutyltin diacetate, dibutyltin dioctate, and dibutyltin dilaurate. The amount of such a curing catalyst is from 0.01 to 0.01 as a solid content in the silicone rubber layer.
It is preferably 20% by weight, preferably 0.1 to 10% by weight. When the amount of the catalyst to be added is 0.01% by weight or more, the curing of the silicone rubber layer does not become insufficient, and there is no problem in the adhesiveness to the heat-sensitive layer. On the other hand, if the content is 20% by weight or less, there is no adverse effect on the pot life of the silicone rubber layer solution.

Further, the direct drawing type waterless planographic printing plate precursor of the present invention is also provided.
Silicone rubber layer in plate is addition polymerization type, condensation polymerization type
Regardless of whether it contains silicone resin
You can also. The silicone resin referred to in the present invention is a three-dimensional
Polyorganosiloxane having a dynamic network structure
Vinyl group-containing polydimethylsiloxane as described above, hydroxyl group-containing
Polydimethylsiloxane, containing SiH group as cross-linking agent
It should be distinguished from polysiloxane. Silico
As resin, straight silicone resin,
Silicone-modified organic resin, but ink rebound
Straight silicone resin is preferred from the viewpoint of properties
No. Furthermore, as a straight silicone resin,
From the skeletal structure of D unit (R_TwoSiO_2/2: R is methyl
Group, phenyl group, organic group such as vinyl group), T unit (R
SiO_3/2: R is methyl group, phenyl group, vinyl group, etc.
Resin which contains an organic group of formula (I) as a main structural unit, and an M unit
(R _ThreeSiO_1/2: R is methyl group, phenyl group, vinyl group
Organic unit such as), Q unit (SiO_4/2) As the main constituent unit
Resin containing, polyorgano consisting of only T units
Silsesquioxane, T unit regularly bonded
Examples include a ladder polymer.

The straight silicone resin is roughly classified into a methyl silicone resin whose organic group mainly comprises a methyl group and a methylphenyl silicone resin having both phenyl groups. Straight silicone rain and methylphenyl-based straight silicone resin having many methyl groups are preferable. Further, silicone resins preferably used in the present invention include silicone rubbers such as SiH groups, vinyl groups, and hydroxyl groups (or functional groups that readily generate hydroxyl groups by hydrolysis such as acetoxy groups, alkoxy groups, and iminoxy groups). It is preferable to use a silicone resin having a SiH group or a silicone resin having a vinyl group.

The silicone resin can be used by adding it to the above-mentioned addition type silicone rubber composition. However, a silicone resin containing a vinyl group or a SiH group, particularly preferably a silicone resin containing a SiH group, is used.
It can also be used as an essential component of the addition type silicone rubber composition. That is, S as an addition polymerization type crosslinking agent
Instead of using the iH group-containing polysiloxane, it is also preferable to use a SiH group-containing silicone resin.

The content of these silicone resins is preferably from 0.1 to 30% by weight, more preferably from 1 to 15% by weight, based on the solid content of the silicone rubber layer. If the addition amount is 0.1% by weight or more, the effect of the addition is sufficiently exhibited,
On the other hand, if the addition amount is 30% by weight or less, the curability of the silicone rubber layer is not adversely affected, and the ink repellency is not adversely affected.

As a method for obtaining a silicone rubber layer from the above-mentioned raw materials, a silicone rubber solution is prepared by dissolving a vinyl group- or hydroxyl group-containing polydimethylsiloxane component in a solvent and then adding a crosslinking agent, a reaction inhibitor, a curing catalyst and the like. And then applying and drying it.

As the solvent, it is preferable to use an aliphatic hydrocarbon or aromatic hydrocarbon solvent. In particular,
Aliphatic hydrocarbons include pentane, hexane, heptane, octane and isoparaffins, normal paraffins, and the like, and aromatic hydrocarbons include toluene, xylene, and mixtures obtained by fractionating petroleum. Specific products that are preferably used as petroleum-based solvents include “ISOPER” and “PEGASO”.
L, “EXXOL”, “SOLVESSO”, “IP
Solvent "and the like.

It is preferable that these solvents be dehydrated in advance, and it is also preferable that the solvent has a dehydration step when preparing the silicone rubber solution. Examples of the dehydrating means include bubbling of a dry gas and introduction of a dehydrating agent such as molecular sieve.However, bubbling of a dry gas is preferable because impurities are not easily brought into a solution.Dry nitrogen gas is particularly preferable because of easy handling. Is preferred. The water content of the solution after dehydration can be measured by a Karl Fischer method or the like, but is preferably suppressed to 40 ppm or less, preferably 20 ppm or less. By sufficiently performing dehydration and keeping the water content to 40 ppm or less, problems such as a decrease in the curability of the silicone rubber solution and a poor adhesion to the heat-sensitive layer do not occur. Further, the pot life is not reduced.

The concentration of the silicone rubber solution is preferably from 3 to 40% by weight, and more preferably from 5 to 15% by weight, in terms of solid content, from the viewpoints of coating properties and drying properties. 3% by weight
By doing so, a certain degree of solution viscosity is ensured, coating properties are improved, and drying efficiency is also obtained. Further, by setting the content to 40% by weight or less, the coating property does not deteriorate due to the increase in viscosity.

A silicone rubber layer can be obtained by applying and drying the silicone rubber solution thus obtained by various coating methods. The thickness of the silicone rubber layer is preferably 0.5 to 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 do not decrease, and when the film thickness is 20 g / m ² or less, it is only advantageous from an economic viewpoint. Also, there is no problem that the developability and the ink mileage are deteriorated.

In the present invention, the heat-sensitive layer preferably has an absorbance characteristic satisfying at least one of the following conditions (I) and (II). That is, (I) the UV absorption spectrum measured by the reflection method is (1) 700 to
The main peak of the absorption spectrum exists between 1200 nm, (2) the absorbance (A) at 830 nm, and 650 nm.
The ratio of the absorbance (B) of the spectrum of: (A / B) is 1.5
As described above, (II) the UV absorption spectrum measured by the transmission method is as follows: (1) the main peak of the absorption spectrum exists between 700 to 1200 nm; (2) the absorbance (A) at 830 nm; Absorbance (B) ratio: (A / B) is 3.0 or more.

The printing plate precursor of the present invention relates to a printing plate precursor made by using a near-infrared semiconductor laser. Therefore, in order to be sensitive to the near-infrared semiconductor laser, the heat-sensitive layer has a thickness of 700 mm. It is necessary that there is a main peak of the absorption spectrum at ~ 1200 nm.

Further, in order to achieve both plate inspection and image reproducibility of the printing plate, the absorbance (A) at 830 nm and the absorbance at 650 nm are used.
It is necessary that the ratio of the absorbance (B) of the spectrum: (A / B) is not less than a certain value.

As a method of measuring the UV absorption spectrum,
There are a reflection method and a transmission method. If the substrate of the printing plate precursor is a UV non-transmitting substrate such as aluminum, the reflection method is used, and if the substrate is a U-plate such as polyethylene terephthalate.
When a V-permeable substrate is used, the measurement is preferably performed by a transmission method.

When measured by the reflection method, this absorbance ratio is:
It is necessary to be 1.5 or more, and preferably, it is preferably 3.0 or more when measured by a transmission method.

By setting the value of the absorbance ratio (A / B) to 1.5 or more in the reflection method and 3.0 or more in the transmission method as described above, the sensitivity to near-infrared laser is high and the image is high. A printing plate having good reproducibility, high contrast after development, and good plate inspection properties can be obtained.

Therefore, the UV absorption spectrum of the heat-sensitive layer
More preferably, the maximum absorbance at 00 to 700 nm is 2 or less. By setting this value to 2 or less, a printing plate having good plate inspection properties can be obtained while maintaining the sensitivity to the semiconductor laser.

In order to obtain a direct drawing type lithographic printing plate precursor having such UV absorption spectrum characteristics, it is preferable to include a dye, a pigment and the like having specific absorption spectrum characteristics in the heat-sensitive layer of the printing plate precursor.

Dyes and pigments giving specific UV absorption spectrum characteristics include cyanine dyes, polymethine dyes, phthalocyanine dyes, naphthalocyanine dyes,
Dithiol metal complex, piazurenium, squarylium, croconium, azo dye, bisazo, bisazostilbene, naphthoquinone, anthraquinone, perylene, indoaniline, benzothiopyran, spiropyran, nigrosine, Among the thioindigo, nitroso, quinoline and fulgide dyes and pigments, (1) 70
The main peak of the absorption spectrum exists between 0 and 1200 nm, and (2) the absorbance (A) at 830 nm and 6
Ratio of absorbance (B) of spectrum at 50 nm: (A / B)
Can be selected from dyes and pigments with a certain value or more, but the peak wavelength often shifts due to interaction with other components in the thermosensitive layer, so the spectrum is measured in the actual printing plate precursor Is preferred.

Some specific examples of such preferred dyes include the following.

(Infrared absorbing dye 1)

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(Infrared absorbing dye 2)

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(Infrared absorbing dye 3)

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(Infrared absorbing dye 4)

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(Infrared absorbing dye 5)

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(Infrared absorbing dye 6)

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(Infrared absorbing dye 7)

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(Infrared absorbing dye 8)

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(Infrared absorbing dye 9)

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(Infrared absorbing dye 10)

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(Infrared absorbing dye 11)

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(Infrared absorbing dye 12)

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(Infrared absorbing dye 13)

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(Infrared absorbing dye 14)

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(Infrared absorbing dye 15)

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(Infrared absorbing dye 16)

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(Infrared absorbing dye 17)

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Specific examples of commercially available preferable dyes include the following products CY-10, CY-17, CY-5, CY-4, CY-4 of the "KAYASORB" series.
-2, CY-20B, CY-30B, IRG-002
(Manufactured by Nippon Kayaku Co., Ltd.), YKR-4010, YKR-
3030, YKR-3070, SIR-159, PA-
1005, SIR-128, YKR-2080, YKR
-2900, PA-1006 (Yamamoto Kasei Co., Ltd.),
“PROJET” 825 LDI, “PROJET” 83
0NP, S1749963, S174270 (Aveci
a Limited), NK-2014, NK-29
11, NK-2912, NK-4432, NK-447
4, NK-4489, NK-4680, NK-477
6, NK-5020, NK-5036, NK-504
2, (Hayashibara Institute of Biological Sciences) IR2T, IR
3T (manufactured by Showa Denko KK), "EXCOLOR" 801
K, IR-1, IR-2, "TX-EX-801B",
“TX-EX-805K” (manufactured by Nippon Shokubai Co., Ltd.), CI
R-1080 (manufactured by Nippon Carlit Co., Ltd.), IR980
11, IR980301, IR980401, IR98
0402, IR980405, IR980406, IR
980504, (YAMADA CHEMICAL
"EPOLIGHT" V-149, V-1
29, V-63, III-184, III-192, I
V-62B, IV-67, VI-19, VI-148
(Manufactured by EPOLIN, Inc.), but is not limited thereto.

The content of these dyes 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, image formation can be performed efficiently, and when the content is 40% by weight or less, the physical properties of the heat-sensitive layer are not adversely affected.

The heat-sensitive layer preferably used in the present invention preferably contains a resin having an active hydrogen group as a main component, and a compound interacting with the resin, in addition to the above-mentioned dye.

Examples of resins having an active hydrogen group include novolak resins and resole resins obtained by the condensation reaction of phenols such as phenol, cresol and xylenol with formaldehyde, phenol / furfural resins,
Examples thereof include a furan resin, a hydroxyl group-containing urethane resin, a p-hydroxystyrene copolymer, and a hydroxyethyl methacrylate copolymer, and a novolak resin is particularly preferable.

Compounds which interact with resins include blocked isocyanates, epoxy group-containing compounds, acrylate compounds, metal chelate compounds, aldehyde group-containing compounds, mercapto group-containing compounds, alkoxysilyl compounds, amine compounds, carboxylic acids, vinyl A group-containing compound, an allyl group-containing compound, a diazonium salt, an azide compound, hydrazine, a leuco dye, a coumarin dye and the like can be mentioned, but a metal chelate compound is particularly preferable.

As the metal chelate compound, Al, T
i, Mn, Fe, Co, Ni, Cu, Zn, Ge, I
n, Sn, Zr, metal diketenates of Hf, metal alkoxides, alkyl metals, metal carboxylate salts, metal oxide chelate compounds, metal complexes, heterometal chelate compounds, among which particularly preferably used compounds include Aluminum, iron (III), titanium acetylacetonate (pentanedionate), ethylacetoacetonate (hexanedionate), propylacetoacetonate (heptanedionate), tetramethylheptanedionate, benzoylacetonates, etc. No. The amount added to the heat-sensitive layer is preferably 3 to 50% by weight, more preferably 5 to 30% by weight of the solid content. When the addition amount is 3% by weight or more,
The effect, that is, the effect of improving image reproducibility is high.
When the content is 0% by weight or less, the physical properties of the heat-sensitive layer hardly deteriorate,
This is because, for example, a problem of printing durability hardly occurs in the printing plate.

The proportion of these resins and compounds interacting with the resin in the heat-sensitive layer is preferably 20 to 95% by weight, more preferably 30 to 70% by weight of the total solids of the heat-sensitive layer. When the content is 20% by weight or more, the solubility or swelling rate change due to a change in the heat-sensitive layer involved in image formation can be maintained. Maintaining the amount does not cause a problem in image formation.

In the present invention, the heat-sensitive layer preferably contains at least one selected from the group consisting of acids, alkalis, amines and organic acid salts of metals.

Specifically, examples of the acid include organic carboxylic acids such as acetic acid, propionic acid, maleic acid and phthalic acid, and acid anhydrides such as acetic anhydride, maleic anhydride and other organic carboxylic acid anhydrides. Are inorganic acids such as toluenesulfonic acid and boric acid, and alkalis such as potassium hydroxide, sodium hydroxide, lithium hydroxide and alkalis such as sodium silicate, diglycolamine, ethylenediamine, ethanolamine, triethylamine,
It has any of amines such as xylylenediamine and organic acid salts of metals. Among these, it is preferable to add an organic acid salt of a metal, particularly tin, lead, zinc,
An organic acid salt of a metal selected from iron, cobalt, calcium and manganese is preferred. Specific examples of such compounds include dibutyltin diacetate, dibutyltin dioctate, and dibutyltin dilaurate.

By adding these compounds to the heat-sensitive layer, a direct-drawing waterless lithographic plate having excellent image reproducibility and stable and excellent adhesion between the silicone rubber layer and the heat-sensitive layer immediately after preparation of the printing plate precursor. A printing plate precursor is obtained. The reason for this is that the compound promotes the reaction between the compound represented by the general formula (I) in the silicone rubber layer and the heat-sensitive layer component, particularly at the interface between the silicone rubber layer and the heat-sensitive layer.

The amount of the compound to be added to the heat-sensitive layer is usually 0.01 to 10% by weight, preferably 0.1 to 5% by weight as a solid content in the heat-sensitive layer. When the amount is 0.01% by weight or more, stable adhesiveness is exhibited. On the other hand, when the amount is 20% by weight or less, there is no adverse effect on the physical properties and image reproducibility of the heat-sensitive layer.

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 known vinyl polymers, unvulcanized rubber, polyoxides (polyethers),
Examples include polyesters, polyurethanes, and polyamides. 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. If the content is 5% by weight or more, problems tend to occur in printing durability and coating properties of the coating solution, and if it is 70% by weight or less, there is no adverse effect on image reproducibility.

The thickness of the heat-sensitive layer is 0.1 to 1
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 transmittance of the heat-sensitive layer in 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. As a result, it is easy to leave the heat-sensitive layer.

Next, a method for producing a direct-drawing waterless planographic printing plate precursor according to the present invention will be described.

Metal substrates such as aluminum and aluminum alloys,
Or use a normal coater such as a reverse roll coater, air knife coater, gravure coater, die coater, or Mayer bar coater, or a rotary coater such as a wheyer on a substrate such as a plastic film such as polyethylene terephthalate, and primer if necessary. After the layer composition is applied and cured by heating at 100 to 300 ° C. for several minutes or by irradiation with actinic rays, the thermosensitive layer composition is applied and dried by heating at 50 to 180 ° C. for several tens seconds to several minutes. After that, the silicone rubber composition is applied and 50
A silicone rubber layer is applied by heat treatment at a temperature of about 200 ° C. for several minutes to obtain a direct-drawing waterless planographic printing plate precursor.

Next, a method for producing a direct-drawing planographic printing plate will be described in detail.

The method for producing a direct-drawing lithographic printing plate of the present invention comprises:
A step of causing the surface layer of the heat-sensitive layer to react by laser irradiation; and a step of removing the ink repellent layer while leaving the heat-sensitive layer of the laser-irradiated portion by rubbing with a brush in the presence of water.

The light source used for laser irradiation includes:
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.

When laser irradiation is performed, the infrared ray absorbing dye in the heat-sensitive layer absorbs the laser beam and generates heat.
At this time, if 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. A preferable laser irradiation energy is 100 to 500 mJ / cm ² .

The printing plate after the laser irradiation is treated with an organic solvent, if necessary, to dissolve or swell the surface layer of the heat-sensitive layer, and then developed by brush rubbing in the presence of water.

As the organic solvent used in the treatment, a glycol compound or a glycol ether compound is preferable. 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 ( M
w: 1200), tetraethylene glycol mono-2-
Ethylhexyl ether, diethylene glycol mono-
2-ethylhexyl ether and the like.

It is preferable that the treatment liquid 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, surfactants and the like 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 is preferable, and more preferably 35 to 45C.

The above-mentioned development step may be performed by a manual method. However, “TWL-1160” or “TW-1” manufactured by Toray Industries, Inc.
L-650 "," TWL-860 "or Patent No. 28
64907, JP-A-6-258842, JP-A-6-258842, JP-A-6-258844
It is preferable to use an automatic developing machine for a waterless lithographic printing plate as disclosed in JP-A-7-92669 and JP-A-7-92692.

A brush generally has a brush material having a diameter of 20 to 500 μm and is implanted in a grooved material such as metal or plastic in a row, and 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.

Instead of the developing system of laser irradiation, organic solvent treatment, and brush rubbing in the presence of water as described above, the printing plate after laser irradiation was treated in the presence of water without any treatment with an organic solvent. A "water developing system" in which development is performed only by rubbing with a brush is also a preferable method.

[0108]

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

Example 1 << Preparation of Direct-Drawing Lithographic Printing Plate Precursor >> Thickness 0.24 mm
A solution having the following composition was applied on a degreased aluminum plate (manufactured by Kobe Steel Ltd.) using a slit die coater, dried at 150 ° C. for 80 seconds, and provided with a heat-sensitive layer of 1.5 g / m ² . . <Thermal Sensitive Layer> (A) “PROJET” 825 LDI (Avec Co., Ltd.)
ia): 11 parts by weight (B) "Nersem Titanium" (manufactured by Nippon Chemical Industry Co., Ltd., acetylacetone solution of titanium di-n-butoxide (bis-2,4-pentanedionate)): 9 parts by weight (solids concentration) (C) "Sumilite Resin" PR50622 (phenol novolak resin, manufactured by Sumitomo Durez Co.): 60 parts by weight (D) "SAMPLEN" T1331D (Polyurethane, Sanyo Chemical) Industrial Co., Ltd.): 10 parts by weight (solid content: 10 parts by weight)
(E) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxypropyltrimethoxysilane =
1/3/1 molar ratio adduct: 10 parts by weight (F) dibutyltin diacetate: 0.5 parts by weight (G) tetrahydrofuran: 700 parts by weight (H) dimethylformamide: 100 parts by weight (I) ethanol: 100 parts by weight Department

Next, a silicone rubber layer described below was applied by a slit die coater at a dry film thickness of 2.0 μm and drying conditions of 125 ° C. for 2 minutes to obtain a direct drawing type lithographic printing plate precursor. <Silicone rubber layer> (a) "Orient oil scarlet"# 308 (C
I21260) (manufactured by Orient Chemical Industry Co., Ltd., λma
x: 500 nm): 2 parts by weight (b) DMS-V52 (manufactured by Gelest Inc.,
α, ω-divinylpolydimethylsiloxane, weight-average molecular weight about 110,000): 100 parts by weight (c) HMS-151 (manufactured by Gelest Inc., a methyl (methyl hydrogen siloxane) (dimethylsiloxane) copolymer at both ends; SiH group-containing polysiloxane, mol% of MeHSiO: 15 to 18%, crosslinking agent):
4 parts by weight (d) Vinyl tri (methylethylketoximine) silane: 3 parts by weight (e) "SRX-212" (manufactured by Toray Dow Corning Silicone Co., Ltd., platinum catalyst): 5 parts by weight (f) "Isopar" E ( Esso Chemical Co., Ltd.): 10
35 parts by weight

<< Manufacture of Direct-Drawing Lithographic Printing Plate >> The direct-drawing lithographic printing plate precursor 1 obtained as described above is referred to as "GX-
3600 "(plate making machine, manufactured by Toray Industries, Inc.), and laser irradiation was performed using a semiconductor laser (wavelength: 830 nm) (irradiation energy: 175 mJ / cm ² , 2400 d).
pi (dots per inch), 175 lpi (lines per inc
h)).

Then, using a waterless lithographic printing plate automatic developing machine “TWL-860KII” (manufactured by Toray Industries, Inc.), the following processing solution 1 was placed in the first tank of the automatic developing machine, Water was charged into the three tanks, and a direct-drawing lithographic printing plate was developed. The temperature of the processing liquid 1 was 40 ° C., and the processing time was 30 seconds. The temperature of the water in the second tank and the third layer was 25 ° C., and the processing time was 15 seconds.

In the first tank, the processing liquid is applied onto the printing plate surface, whereby the surface layer of the heat-sensitive layer dissolves or swells. <Treatment liquid 1> (a) Diethylene glycol: 80 parts by weight (b) Diethylene glycol amine: 15 parts by weight (c) 40% aqueous solution of sodium 2-ethylhexyl sulfate (anionic surfactant): 1 part by weight (d) Water: 4 parts by weight

In the process in which the printing plate is automatically conveyed from the first tank to the second tank, the processing liquid on the printing plate surface is removed by a roll. In the second tank, the printing plate is a brush rotating in the same rotation direction as the printing plate transport direction in a state where water is applied to the plate surface, and in the third tank, a brush rotating in the opposite direction. Rubbed with. As a result, the heat-sensitive layer at the portion irradiated with the laser beam remained, and a direct-drawing lithographic printing plate from which the silicone rubber layer had been removed was obtained.

<< Evaluation of Plate Inspection Property >>
The plate inspection property was evaluated by observing with a magnifier of 5 times. As a result, it was possible to easily confirm the halftone dots of 1%, and it was found that the plate inspection property after plate making was good.

<< Evaluation of Image Reproducibility >> The obtained printing plate was attached to a sheet-fed offset printing machine “Sprint 25” (manufactured by Komori Corporation), and a waterless lithographic ink “Dryocolor NSI” was used. Printing on high quality paper (62.5 kg / chrysanthemum) using indigo (manufactured by Dainippon Ink and Chemicals, Inc.) and evaluating the image reproducibility as a printed material,
It was found that the image reproducibility was as good as 99%.

<< Measurement of UV Spectrum of Printing Plate >>
"Spectrophotometer U-3210" (manufactured by Hitachi, Ltd.)
The UV absorption spectrum of the heat-sensitive layer in the image area of the obtained direct drawing type lithographic printing plate precursor was measured by a reflection method using an integrating sphere.

As a result, the main peak was at 750 nm, and the absorbance (A) at 830 nm was 1.34, 6
The absorbance (B) at 50 nm is 0.72, the ratio value (A / B) is 1.86, 1.5 or more, and the maximum absorbance at 400 to 700 nm is 1.9.
9 was obtained, which was 2 or less.

Comparative Example 1 << Preparation of Direct-Drawing Lithographic Printing Plate Precursor >> A printing plate precursor was prepared in the same manner as in Example 1 except that the silicone rubber layer was changed to a composition containing no dye as described below. The lithographic printing plate precursor was directly produced and obtained. <Silicone Rubber Layer> (a) DMS-V52 (manufactured by Gelest Inc.
α, ω-divinylpolydimethylsiloxane, weight average molecular weight about 110,000): 100 parts by weight (b) HMS-151 (manufactured by Gelest Inc., both ends methyl (methylhydrogensiloxane) (dimethylsiloxane) copolymer) SiH group-containing polysiloxane, mol% of MeHSiO: 15 to 18%, crosslinking agent):
4 parts by weight (c) Vinyl tri (methyl ethyl ketoximine) silane: 3 parts by weight (d) "SRX-212" (manufactured by Toray Dow Corning Silicone Co., Ltd., platinum catalyst): 5 parts by weight (e) "ISOPAR" E ( Esso Chemical Co., Ltd.): 10
35 parts by weight When evaluated in the same manner as in Example 1, the printed matter was 1 to 99 parts by weight.
%, And good image reproducibility was confirmed, but only up to 4% halftone dots could be confirmed by observing the printing plate itself.

Example 2 << Preparation of Direct-Drawing Lithographic Printing Plate Precursor >> A printing plate precursor was prepared in exactly the same manner as in Example 1 except that the composition of the silicone rubber layer was changed to the following composition. Were evaluated in exactly the same way. <Silicone Rubber Layer> (a) “Eizen Spiron Red” GEH Special (Hodogaya Chemical Industry Co., Ltd., λmax: 498 nm):
2 parts by weight (b) α, ω-divinylpolydimethylsiloxane (weight average molecular weight: about 90,000): 100 parts by weight (c) HMS-151 (manufactured by Gelest Inc., both ends methyl (methylhydrogensiloxane) (dimethyl) Siloxane) copolymer, SiH group-containing polysiloxane, mol% of MeHSiO: 15 to 18%, crosslinking agent):
7 parts by weight (d) Vinyl tri (methylethylketoximine) silane: 3 parts by weight (e) "SRX-212" (manufactured by Toray Dow Corning Silicone Co., Ltd., platinum catalyst, curing catalyst): 7 parts by weight (f) "ISOPAR""E (Esso Chemical Co., Ltd., solvent): 1035 parts by weight

Evaluation was made in the same manner as in Example 1. As a result, it was possible to easily confirm a halftone dot of 1% even in the printing plate after development, the plate inspection property after plate making was good, and the printed matter was 1 to 30%. Good image reproducibility of 99% was confirmed. [Example 3]

<< Preparation of Direct-Drawing Lithographic Printing Plate Precursor >> A printing plate precursor was prepared in exactly the same manner as in Example 1 except that the composition of the silicone rubber layer was changed to the following composition, and evaluation was conducted in exactly the same manner. did. <Silicone rubber layer> (a) "Orient oil scarlet"# 308 (C
I21260) (manufactured by Orient Chemical Industry Co., Ltd., λma
x: 500 nm): 2 parts by weight (b) α, ω-divinylpolydimethylsiloxane (weight average molecular weight: about 90,000): 100 parts by weight (c) HQM-105 (manufactured by Gelest Inc., S
iH group-containing silicone resin): 5 parts by weight (d) Vinyl tri (methylethylketoximine) silane: 3 parts by weight (e) “SRX-212” (Toray Dow Corning Silicone Co., Ltd., platinum catalyst, curing catalyst): 5 Parts by weight (f) "Isopar" E (manufactured by Esso Chemical Co., Ltd., solvent): 735 parts by weight (g) Toluene: 300 parts by weight When evaluated in the same manner as in Example 1, the printing plate after development was also 1%. Can be easily confirmed up to halftone dots, and the plate inspection property after plate making is good, and even printed matter is 1 to 99 dots.
% And good image reproducibility were confirmed.

Example 4 A solution having the following composition was applied on a degreased aluminum plate having a thickness of 0.24 mm.
After drying at 0 ° C. for 80 seconds, a heat-sensitive layer having a dry film thickness of 1.5 g / m ² was provided. <Thermal Sensitive Layer> (A) “YKR-2900” (infrared absorbing dye, manufactured by Yamamoto Kasei Co., Ltd.): 11 parts by weight (B) “Nersem Titanium” (titanium di-n-butoxide bis (2,4-pentanedionate)) Nippon Chemical Industry Co., Ltd., metal chelate compound): 9 parts by weight (C) "Sumilite Resin" PR54652 (phenol novolak resin, manufactured by Sumitomo Durez Co., Ltd.): 60 parts by weight (D) "SAMPLEN" T-1331D (Polyurethane resin, manufactured by Sanyo Chemical Industries, Ltd.): 10 parts by weight (E) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxypropyltrimethoxysilane =
1/3/1 molar ratio addition reactant: 15 parts by weight (F) tetrahydrofuran: 800 parts by weight (G) dimethylformamide: 100 parts by weight

Next, the following silicone rubber layer was applied by a slit die coater at a dry film thickness of 2.0 μm and a drying condition of 125 ° C. × 2 minutes to obtain a direct drawing type lithographic printing plate precursor. <Silicone rubber layer> (a) "Orient oil scarlet"# 308 (C
I21260) (manufactured by Orient Chemical Industry Co., Ltd., λma
x: 500 nm): 2 parts by weight (b) DMS-V52 (manufactured by Gelest Inc.,
α, ω-divinylpolydimethylsiloxane, weight-average molecular weight about 110,000): 100 parts by weight (c) HMS-151 (manufactured by Gelest Inc., a methyl (methyl hydrogen siloxane) (dimethylsiloxane) copolymer at both ends; SiH group-containing polysiloxane, mol% of MeHSiO: 15 to 18%, crosslinking agent):
4 parts by weight (d) Vinyl tri (methylethylketoximine) silane: 3 parts by weight (e) "SRX-212" (manufactured by Toray Dow Corning Silicone Co., Ltd., platinum catalyst): 5 parts by weight (f) "Isopar" E ( Esso Chemical Co., Ltd.): 10
35 parts by weight

Evaluation was made in the same manner as in Example 1. As a result, it was possible to easily confirm a halftone dot of 1% even in the printing plate after development, and the plate inspection property after plate making was good. Good image reproducibility of 99% was confirmed.

When the UV absorption spectrum of the heat-sensitive layer in the image area of the direct-drawing lithographic printing plate precursor was measured by the reflection method in the same manner as in Example 1, the main peak was at 810 nm.
The value (A / B) of the ratio of the absorbance (A) at 830 nm to the absorbance (B) at 650 nm is 4.11 and 1.5 or more, and the maximum absorbance at 400 to 700 nm is 1.01 and 2 Was

Example 5 << Preparation of Direct-Drawing Lithographic Printing Plate Precursor >> A printing plate precursor was prepared in exactly the same manner as in Example 4 except that the composition of the silicone rubber layer was changed to the following composition. Were evaluated in exactly the same manner. <Silicone Rubber Layer> (a) "Eizen Spiron Violet" RH (manufactured by Hodogaya Chemical Industry Co., Ltd., λmax: 560 nm): 2 parts by weight (b) Polydimethylsiloxane having hydroxyl groups at both terminals (weight average molecular weight of about 90,000) ): 100 parts by weight (c) Vinyl tri (methylethylketoximine) silane: 5 parts by weight (d) Dibutyltin diacetate (catalyst): 0.5 parts by weight (e) "ISOPAR" E (manufactured by Esso Chemical Co., Ltd.) Solvent): 1035 parts by weight

Evaluation was made in the same manner as in Example 4. As a result, it was possible to easily confirm the halftone dots of 1% in the printing plate after development, and the plate inspection property after plate making was good. Good image reproducibility of 99% was confirmed.

Comparative Example 2 << Preparation of Direct-Drawing Lithographic Printing Plate Precursor >> A printing plate precursor was prepared in the same manner as in Example 4 except that the silicone rubber layer was changed to the following composition. A lithographic printing plate precursor was obtained. <Silicone Rubber Layer> (a) “YKR-2900” (infrared absorbing dye, manufactured by Yamamoto Kasei Co., Ltd., λmax: 810 nm): 3 parts by weight (b) DMS-V52 (manufactured by Gelest Inc.)
α, ω-divinylpolydimethylsiloxane, weight-average molecular weight about 110,000): 100 parts by weight (c) HMS-151 (manufactured by Gelest Inc., a methyl (methyl hydrogen siloxane) (dimethylsiloxane) copolymer at both ends; SiH group-containing polysiloxane, mol% of MeHSiO: 15 to 18%, crosslinking agent):
4 parts by weight (d) Vinyl tri (methylethylketoximine) silane: 3 parts by weight (e) "SRX-212" (manufactured by Toray Dow Corning Silicone Co., Ltd., platinum catalyst): 5 parts by weight (f) "Isopar" E ( Esso Chemical Co., Ltd.): 10
35 parts by weight

Evaluation was performed in the same manner as in Example 1. As a result, good image reproducibility of 1 to 99% was confirmed in the printed matter, but it was difficult to distinguish the silicone rubber layer from the heat-sensitive layer by observing the printing plate itself. Only 3% of the dots could be confirmed.

Example 6 A solution having the following composition was applied on a 50 μm-thick polyethylene terephthalate film “Lumilar” T150 (manufactured by Toray Industries, Inc.) using a bar coater, and dried at 150 ° C. for 80 seconds. 1.5g
/ M ² . <Thermal Sensitive Layer> (A) “YKR-2900” (infrared absorbing dye, manufactured by Yamamoto Kasei Co., Ltd.): 11 parts by weight (B) “Nasem Titanium” (manufactured by Nippon Chemical Industry Co., Ltd., titanium di-n-butoxide (bis) Acetylacetone solution of -2,4-pentanedionate): 9 parts by weight (calculated based on a solid content of 40% by weight; solids content of 9 parts by weight) (C) "Sumilite Resin" PR50622 (phenol novolak resin, Sumitomo Durez) (D) "Samprene" T1331D (polyurethane, manufactured by Sanyo Chemical Industries, Ltd.): 10 parts by weight (solid content: 10 parts by weight)
(E) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxypropyltrimethoxysilane =
1/3/1 molar ratio adduct: 10 parts by weight (F) dibutyltin diacetate: 0.5 parts by weight (G) tetrahydrofuran: 800 parts by weight (H) dimethylformamide: 100 parts by weight

Next, the following silicone rubber layer was applied by a bar coater at a dry film thickness of 2.0 μm and drying conditions of 125 ° C. for 2 minutes to obtain a direct drawing type lithographic printing plate precursor. <Silicone Rubber Layer> (a) “Oil Red” # 809 (Yamamoto Kasei Co., Ltd.
λmax: 504 nm): 2 parts by weight (b) α, ω-divinylpolydimethylsiloxane (weight average molecular weight: about 90,000): 100 parts by weight (c) HMS-151 (manufactured by Gelest Inc.) (Gensiloxane) (dimethylsiloxane) copolymer, SiH group-containing polysiloxane, mol% of MeHSiO: 15 to 18%, crosslinking agent):
7 parts by weight (d) Vinyl tri (methylethylketoximine) silane: 3 parts by weight (e) "SRX-212" (manufactured by Toray Dow Corning Silicone Co., Ltd., platinum catalyst, curing catalyst): 7 parts by weight (f) "ISOPAR""E (Esso Chemical Co., Ltd., solvent): 1035 parts by weight

The direct-drawing lithographic printing plate precursor obtained as described above was irradiated with laser in the same manner as in Example 1 to obtain a plate having a thickness of 0.1 mm.
After pasting on a 15 mm aluminum plate, development was performed in the same manner as in Example 1 to obtain a direct-drawing type lithographic printing plate.

Evaluation was made in the same manner as in Example 1. As a result, the image reproducibility of the printed matter was 1 to 99%, and the plate inspection of the printing plate was 1% or more.

<< Measurement of UV Spectrum of Printing Plate >>
"Spectrophotometer U-3210" (manufactured by Hitachi, Ltd.)
The UV absorption spectrum of the heat-sensitive layer in the image area of the obtained direct-drawing lithographic printing plate was measured by a transmission method.

As a result, the main peak was present at 815 nm, and the ratio (A / B) of the absorbance (A) at 830 nm to the absorbance (B) at 650 nm was 11.6. The maximum absorbance at 400-700 nm is 0.
12, which was 2 or less.

Example 7 A solution having the following composition was applied on a 50 μm-thick polyethylene terephthalate film “Lumilar” T150 (manufactured by Toray Industries, Inc.) using a bar coater, and dried at 150 ° C. for 80 seconds. 1.5g
/ M ² . <Thermal Sensitive Layer> (A) “PROJET” 825 LDI (Avec Co., Ltd.)
ia): 11 parts by weight (B) "Nersem Titanium" (manufactured by Nippon Chemical Industry Co., Ltd., acetylacetone solution of titanium di-n-butoxide (bis-2,4-pentanedionate)): 9 parts by weight (solids concentration) (C) "Sumilite Resin" PR50622 (phenol novolak resin, manufactured by Sumitomo Durez Co.): 60 parts by weight (D) "SAMPLEN" T1331D (Polyurethane, Sanyo Chemical) Industrial Co., Ltd.): 10 parts by weight (solid content: 10 parts by weight)
(E) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxypropyltrimethoxysilane =
1/3/1 molar ratio adduct: 10 parts by weight (F) dibutyltin diacetate: 0.5 parts by weight (G) tetrahydrofuran: 700 parts by weight (H) dimethylformamide: 100 parts by weight (I) ethanol: 100 parts by weight Department

Next, the following silicone rubber layer was applied by a bar coater at a dry film thickness of 2.0 μm under a drying condition of 125 ° C. for 2 minutes to obtain a direct drawing type lithographic printing plate precursor. <Silicone Rubber Layer> (a) “Oil Red” # 809 (Yamamoto Kasei Co., Ltd.
λmax: 504 nm): 2 parts by weight (b) α, ω-divinylpolydimethylsiloxane (weight average molecular weight: about 90,000): 100 parts by weight (c) HMS-151 (manufactured by Gelest Inc.) (Gensiloxane) (dimethylsiloxane) copolymer, SiH group-containing polysiloxane, mol% of MeHSiO: 15 to 18%, crosslinking agent):
7 parts by weight (d) Vinyl tri (methylethylketoximine) silane: 3 parts by weight (e) "SRX-212" (manufactured by Toray Dow Corning Silicone Co., Ltd., platinum catalyst, curing catalyst): 7 parts by weight (f) "ISOPAR""E (Esso Chemical Co., Ltd., solvent): 1035 parts by weight

The direct-drawing lithographic printing plate precursor obtained as described above was irradiated with laser in the same manner as in Example 1 to obtain a plate having a thickness of 0.1 mm.
After pasting on a 15 mm aluminum plate, development was performed in the same manner as in Example 1 to obtain a direct-drawing type lithographic printing plate.

Evaluation was performed in the same manner as in Example 6. As a result, the image reproducibility of the printed matter was 1 to 99%, and the plate inspection of the printing plate was 1% or more, which was a good result.

When the UV absorption spectrum of the heat-sensitive layer in the image area of the direct drawing type lithographic printing plate precursor was measured by the transmission method in the same manner as in Example 6, the main peak was at 798 nm.
The value (A / B) of the ratio of the absorbance (A) at 830 nm to the absorbance (B) at 650 nm is 8.4 and 1.5 or more, and the maximum absorbance at 400 to 700 nm is 1.17. Was below

[0142]

[Table 1]

[0143]

[Table 2]

[0144]

According to the present invention, image reproducibility is good,
A direct-drawing lithographic printing plate with good plate inspection properties can be obtained.

Continued on front page F-term (reference) 2H025 AA00 AA04 AB04 AC08 AD01 AD03 CC20 DA37 FA03 FA17 2H096 AA00 AA13 BA16 EA04 GA08 LA16 2H114 AA05 AA22 AA24 BA01 DA04 DA32 DA38 DA59 DA60 DA62 DA73 DA78 EA02 FA16 GA34 GA38

Claims (3)

[Claims] 1. A direct-drawing lithographic printing plate precursor having at least a heat-sensitive layer and an ink repellent layer on a substrate in this order, characterized in that the ink-repellent layer contains a dye. Printing plate original. 2. A wavelength (λma) showing the maximum value of the absorbance of the dye.
2. The direct-lithographic printing plate precursor according to claim 1, wherein x) is in the range of 400 to 700 nm. 3. The direct drawing type lithographic printing plate precursor according to claim 1, wherein the heat-sensitive layer has an absorbance characteristic of at least one of the following (I) or (II). (I) UV absorption spectrum measured by reflection method: (1) Main peak of absorption spectrum exists between 700 and 1200 nm; (2) Absorbance at 830 nm (A) and Absorbance at 650 nm spectrum (B) Ratio: (A / B) is 1.5 or more. (II) The UV absorption spectrum measured by the transmission method is as follows: (1) the main peak of the absorption spectrum exists between 700 and 1200 nm; (2) the absorbance at 830 nm (A) and the absorbance at 650 nm (B) Ratio: (A / B) is 3.0 or more.