JP2001063235A - Radiant ray sensitive lithographic printing original sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiant ray sensitive lithographic printing original sheet which is sufficient in sensitivity (sensitivity of polar conversion) and free from generating a print stain while the radiant ray sensitive lithographic printing original sheet capable of enabling direct plate from a digital data of a computer or the like by an infrared laser is provided. SOLUTION: In a radiant ray sensitive lithographic printing original sheet having sensitive layer comprising a polymer compound and a photo-thermal convertion agent, the polymer compound is a crosslinked polymer compound having a functional group which is converted from a hydrophobic nature to a hydrophillic nature by acid radiant ray or heat, and the photo-thermal convertion agent is a metal oxide particle containing an organic photo-thermal conversion compound. It is especially the radiant ray sensitive lithographic printing original sheet containing the polymer compound wherein the functional group converts a porality by acid, radiation ray or heat being a sulfonate group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-sensitive lithographic printing plate, and more particularly to a printing plate for a positive polarity conversion type unprocessed printing plate.

[0002]

2. Description of the Related Art Generally, a lithographic printing original plate comprises an oleophilic image area for receiving ink during a printing process and a hydrophilic non-image area for receiving fountain solution. As an original plate for producing such a lithographic printing plate, a PS plate provided with a lipophilic photosensitive resin layer on a hydrophilic support has been widely used. The plate making method of the PS plate is a method of exposing through a lith film or the like on which an image is recorded, and then dissolving and removing a non-image portion with a developing solution, and a desired printing plate is obtained by this method.

A disadvantage of the conventional plate making process of a PS plate is that a developing process is required to dissolve and remove a non-image portion. One of the disadvantages is that this additional wet process is not required or is simplified. There are two issues. In particular, in recent years, the disposal of waste liquid discharged from wet processing has become a major concern of the entire industry due to consideration for the global environment, and the demand for improvement in this aspect has been further increased.

[0004] As one of the simple plate making methods responding to this demand, there has been proposed a plate making method in which an image is formed on an original plate without performing development processing using heat energy by photothermal conversion. In particular, since high-power solid-state lasers such as semiconductor lasers and YAG lasers have become available at low cost, photothermal conversion type plate-making methods using these lasers as image recording means have recently been promising. It has become so. In this type of plate making method, high-power laser exposure using a high-power laser is used to irradiate a large amount of light energy onto the exposed area during an instantaneous exposure time, thereby efficiently converting the light energy to heat energy. After conversion, the heat causes a thermal change such as a chemical change, a phase change, a change in form or structure, and the change is used for image recording. In other words, image information is input by light energy,
Image recording is recorded by reaction with thermal energy. Usually, a recording method utilizing heat generated by such high power density exposure is called heat mode recording, and converting light energy into heat energy is called photothermal conversion.

[0005] An example of an infrared laser-sensitive positive planographic printing plate containing an infrared absorber is disclosed in
An example in which an acid-decomposable carboxylic acid ester disclosed in Japanese Patent No. 186562 and an infrared absorbing dye are used in combination, and an example in which an ablation-type polymer disclosed in US Pat. No. 5,605,780 and an infrared absorbing dye are used in combination are known. Have been. An example in which a negative type lithographic printing plate sensitive to infrared laser is used is disclosed in JP-A-56-6919.
No. 3, JP-A-7-20629, JP-A-7-27102
No. 9 discloses an example in which a resole resin, which is a thermally crosslinkable resin, an acid generator, and an infrared absorber are used in combination. However, these planographic printing original plates are not sufficiently sensitive from a practical point of view, and further higher sensitivity has been desired. In addition, many of the infrared absorbers used in these lithographic printing original plates often decompose themselves after photothermal conversion to become hydrophobic, and remain as a residual film in an exposed portion, or become fountain solution during printing. In some cases, a solid phase may be formed in the form of a residue, thereby causing contamination.

The following two typical examples of conventional positive polarity conversion type unprocessed printing plates whose technology has been developed to solve the defect can be given. One is EP65
No. 2483, a positive type non-process printing plate using a polymer having a group that changes from hydrophobic to hydrophilic by heat, such as an alkoxyalkyl ester group. The other one is
It is a positive type unprocessed printing plate containing a silica gel-containing sol-gel cross-linked sulfonate compound. In each case, the above-mentioned defects have been improved. However, since the contamination of the non-image area is an important characteristic of print quality, further improvement is required.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a radiation-sensitive lithographic printing plate which does not require any special processing such as wet development or rubbing after image writing. In particular, it is an object of the present invention to provide a radiation-sensitive lithographic printing plate that can be directly made from digital data by recording using a solid-state laser or semiconductor laser that emits infrared light. Specifically, the object of the present invention is to
An object of the present invention is to provide a positive-working radiation-sensitive lithographic printing plate capable of obtaining a printed matter having high printing durability and having no stain on an image portion.

[0008]

Means for Solving the Problems The present inventor has found that the thermal decomposition of a photothermal conversion compound such as an infrared absorbing agent is a major cause of printing stains, and directly put the photothermal conversion compound into the polarity conversion layer. Instead of adding, for example, it has been found that when a photothermal conversion compound is encapsulated in the structure of a protective material such as silica gel particles and added in the form of metal oxide particles encapsulating the photothermal conversion compound, printing stains can be prevented. That is, the inclusion of the compound reduces the action of the photothermal conversion compound being decomposed and rendered hydrophobic upon irradiation with laser light, increases the hydrophilicity of the light irradiation area, and improves the stainability of the non-image area. I understood. As a result of further studies on a printing plate capable of embodying this finding, the combination of the above-mentioned metal oxide particles encapsulating light-to-heat conversion compound with a specific polymer compound shows the effect of printing durability and printing stain suppression as the object of the invention. Was found to be even more effective.

That is, a first aspect of the present invention is a radiation-sensitive lithographic printing original plate comprising a support and a sensitive layer comprising at least a binder and a light-to-heat conversion agent, wherein the binder is Having a functional group that changes from hydrophobic to hydrophilic by an acid, radiation or heat, and a crosslinked polymer compound, wherein the photothermal conversion agent is a metal oxide particle containing an organic photothermal conversion compound. A radiation-sensitive lithographic printing plate precursor characterized in that:

The photothermal conversion agent contained in the sensitive layer of the radiation-sensitive lithographic printing plate of the present invention is characterized by containing an organic light-to-heat conversion compound, and is particularly suitable for the purpose of the present invention. The organic light-to-heat conversion compound is an infrared absorbing dye (hereinafter, sometimes simply referred to as “infrared absorbing agent”, “infrared absorbing agent in the present invention” or “IR dye”). Since the organic light-to-heat conversion compound is encapsulated and protected, it is not decomposed by a laser beam and does not become hydrophobic, so that the hydrophilicity of the exposed area is enhanced, and at the same time, the printing stain of the non-image area due to the decomposition product can be prevented. Reached. The binder constituting the sensitive layer in combination with the photothermal conversion agent has a functional group that changes from hydrophobic to hydrophilic by an acid, radiation or heat, and is a cross-linked polymer compound. Such polymer compounds include polymer compounds cross-linked by photocrosslinking, photopolymerization, and photodecomposition polymerization. Among them, secondary sulfonic acid ester groups or alkoxycarboxylic acid ester groups are functional groups. In particular, the above-mentioned effects of the present invention are significantly enhanced.

The crosslinking method of the polymer compound having a functional group which changes from hydrophobic to hydrophilic by an acid, radiation or heat and which is used as a binder in the present invention is photocrosslinking, photopolymerization. And a light or thermal hydrolysis polymerization type is used. Among them, a functional group that changes from hydrophobic to hydrophilic by an acid, radiation or heat, and a functional group that reacts with a hydrolyzable polymerizable compound represented by the following general formula (1) are included in the same molecule. Having the following general formula (1)
A compound obtained by reacting the compound with a hydrolysis-polymerizable compound represented by the formula (1) is a preferred binder.

Formula (1) (R ₁ ) _n -X- (OR ₂ ) _{4-n In the} formula, R ₁ and R ₂ may be the same or different, and represent an alkyl group or an aryl group. X is Si,
Represents Al, Ti or Zr, and n represents an integer of 0 to 2.

In a radiation-sensitive lithographic printing plate using the binder, a hydrolysis-polymerizable compound is hydrolyzed and polymerized to form an inorganic oxide matrix (hydrolysis-polymerized product) in a coating film, As a whole, the film strength of the sensitive layer is improved. Therefore, such a radiation-sensitive lithographic printing plate has extremely high printing durability.

Among the above-mentioned hydrolysis-polymerizable binders,
A sulfonic acid ester group and / or an alkoxyalkyl ester group and —OH, —NH ₂ , —COOH,
NH—CO—R ₃ , —Si (OR ₄ ) ₃ [wherein R ₃ and R ₄ represent an alkyl group or an aryl group, and when both R ₃ and R ₄ are present in a compound having these functional groups] May be the same or different], and a compound having, in the same molecule, at least one functional group selected from the group consisting of a compound represented by the following general formula (1): The compound obtained by reacting with the above provides a radiation-sensitive lithographic printing plate particularly suitable for the purpose of the present invention.

Formula (1) (R ₁ ) _n -X- (OR ₂ ) _{4-n In the} formula, R ₁ and R ₂ may be the same or different, and represent an alkyl group or an aryl group. X is Si,
Represents Al, Ti or Zr, and n represents an integer of 0 to 2.

[0016] The binder includes "sulfonic acid ester and
And / or alkoxyalkyl ester group ”(hereinafter, referred to as“
It may be referred to as “functional group X”. ) And "-O
H, -NH_Two, -COOH, -NH-CO-R_Three, -S
i (OR_Four)_Three[Where R_ThreeAnd R_FourIs an alkyl group or
Represents an aryl group, and among compounds having these functional groups,
R _ThreeAnd R_FourIf both exist, they are the same.
It may be the same or different. ]
At least one functional group "(hereinafter referred to as" functional group Y ")
There is. ) In the same molecule (hereinafter referred to as “
Compound A ". ) And "the above general formula (1)
A hydrolysis-polymerizable compound represented by the formula:
Has become. For example, a binder is applied on a suitable support.
The hydrolysis-polymerizable compound is hydrolyzed and polymerized
When the oxide matrix is formed in the coating film,
Then, it reacts with the functional group Y of the compound A to form an organic-inorganic composite (anti-
Reaction product), the cross-linking structure becomes dense, and the entire sensitive layer
As a result, the film strength is improved. Therefore, such radiation sensitivity
The lithographic printing plate has extremely high printing durability.

In addition, the sensitive layer of the present invention may contain, if necessary, a low-molecular compound having the same polarity conversion action by an acid, radiation or heat, and may contain an acid generator and the like. It is also preferred. Regarding the acid generator,
The infrared absorber itself having a hydrophobic functional group that changes to hydrophilic by heat itself also exhibits the effect of the acid generator, so the acid generator is not necessarily required, but in order to further improve the sensitivity, the acid generator is used. May be effective. Hereinafter, these components will be described.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Structure of Radiation-Sensitive Layer] The present invention can be applied to both negative and positive heat-sensitive lithographic printing original plates. This is a positive printing original plate whose polarity changes to hydrophilic. The radiation-sensitive layer in the present invention comprises (1) a light-to-heat conversion agent in the form of metal oxide particles containing the above-mentioned light-to-heat conversion compound, and (2) a binder which is hydrophobic by acid, radiation or heat. It has a functional group which changes to hydrophilic and is combined with a crosslinked polymer compound. Among the polymer compounds to be combined,
WO92 / 9934 (3M) Polymer compounds containing, as a functional group, an alkoxyalkyl ester group which changes from hydrophobic to hydrophilic, which is used in a positive photosensitive material described in JP-A-10-28267
The polymer compound containing a sulfonic acid ester group, which similarly changes from hydrophobic to hydrophilic, which is used in the positive photosensitive material described in 2, can be particularly preferably used. Hereinafter, each component constituting the radiation-sensitive layer of the lithographic printing plate of the invention will be described.

1. Light-to-heat conversion agent The light-to-heat conversion agent of the present invention is metal oxide particles containing an organic light-to-heat conversion compound as described above. First, a method for encapsulating an organic light-to-heat conversion compound in metal oxide particles will be described.

[Encapsulation Method of Organic Light-to-Heat Conversion Compound] The effect of the present invention is remarkable when the organic light-to-heat conversion compound is an infrared absorbing dye (IR dye). The encapsulation of the organic photothermal conversion compound can also be performed according to the following. The IR dye-containing metal oxide particles can be produced by using an existing method. As the metal oxide particles, a method for producing metal oxide particles from a hydrolyzable alkoxy metal compound is preferable from a synthetic viewpoint. That is, an IR dye and a hydrolyzable polymerizable alkoxy metal compound are used as raw materials for the IR dye-containing metal oxide particles, and both are dissolved or mixed in a solution containing water.
Next, an acid or alkali catalyst is added to the aqueous solution or aqueous dispersion to cause hydrolysis and polymerization (condensation) of the hydrolyzable polymerizable alkoxymetal compound. The IR dye is incorporated into the gel structure of the metal oxide generated in the course of this polymerization reaction, and metal oxide particles having the desired photothermal conversion compound embedded therein can be obtained. As a specific method for producing metal oxide particles in which a light-to-heat conversion compound is embedded, CJ Serna, Journal of Non-Cryst. Sol
ids, vol 147 & 148, page 621 (1992) Spray method, written by Shuichi Shibata, industrial materials, vol 46, no 8, page 37
(1988), and S. Shibata, Journal of Sol-GelScience
and Technology, vol 2, page 755 (1994). D.Avnir,
Journal of Physical Chemistry, vol 88, page 5956
(1984), and SKLam, Chemical Physics Letters vol
As described in 281, page 35 (1997), it is possible to adopt a method in which once metal oxide particles with an organic light-to-heat conversion compound are embedded, fine particles are created by mechanical pulverization. .

[Metal oxide for inclusion of organic light-to-heat conversion compound] The metal oxide for inclusion of a light-to-heat conversion compound used in the present invention will be described. Examples of the metal of the metal oxide include alkaline earth metals, transition metals, rare earth metals, and 3 to 5 of the periodic table.
Group metals. The metal oxide of the present invention is preferably obtained by a polymerization reaction of a hydrolysis-polymerizable organometallic compound of these metals.

Examples of the metal element in the hydrolysis-polymerizable organometallic compound include alkaline earth metals, transition metals, rare earth metals, and metal elements belonging to Groups 3 to 5 of the periodic table. Of these, preferred metals are group 3b of the periodic table,
Group A and Group 4b metal elements such as aluminum, titanium, zircon, silica and the like. Particularly preferred are aluminum and silica, and more preferred is silica. These metal elements may be contained alone or in combination of two or more in the metal oxide. Examples of the hydrolyzable polymerizable group in the hydrolyzable organic metal compound include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a pentyloxy group, and a hexyloxy group. To 10 alkoxy groups. Among these, an alkoxy group having 1 to 4 carbon atoms is preferable, and a methoxy group, an ethoxy group, and a propoxy group are particularly preferable. The organometallic compound may contain only one kind or two or more kinds of these hydrolyzable polymerizable groups, but it is necessary to contain at least two or more kinds in the organometallic compound.

In the above-mentioned hydrolysis-polymerizable organometallic compound,
Examples of those containing aluminum include trimethoxyaluminate, triethoxyaluminate, and tripropoxyaluminate. Examples of the compound containing titanium include, for example, trimethoxytitanate, tetramethoxytitanate, triethoxytitanate, tetraethoxytitanate, tetrapropoxytitanate, chlorotrimethoxytitanate, chlorotriethoxytitanate, ethyltrimethoxytitanate, methyltriethoxytitanate, ethyl Examples thereof include triethoxy titanate, diethyl diethoxy titanate, phenyl trimethoxy titanate, and phenyl triethoxy titanate. As the compound containing zircon, for example, zirconate corresponding to the compound containing titanium can be mentioned.

In the above-mentioned hydrolysis-polymerizable organometallic compound,
Examples of the compound containing silicon include a compound represented by the following formula. In _{^{(R 1) n Si (OR}} 2) 4-n Formula, R ¹ represents an alkyl group or an aryl group having 1 to 4 carbon atoms which may have a substituent, R ¹ is 1 to 4 carbon atoms Represents an alkyl group, and R ¹ and R ² may be the same or different. n represents the integer of 0-2. Specific examples of the organometallic compound containing silicon include trimethoxysilane, triethoxysilane, tripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane. Methoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, γ-chloropropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane , Γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxy Orchid, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like. Of these, preferred are tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane , Diphenyldimethoxysilane, diphenyldiethoxysilane and the like.

The above-mentioned hydrolysis-polymerizable organometallic compound is
One type may be used alone, or two or more types may be used in combination. After partial hydrolysis, dehydration condensation may be performed.

[Organic Light-to-Heat Conversion Compound Included in Metal Oxide] Next, the light-to-heat conversion substance included in the metal oxide and constituting the light-to-heat conversion agent will be described. As the photothermal conversion material used in the present invention, any substance that can convert light into heat by absorbing light such as ultraviolet light, visible light, infrared light, and white light can be used.For example, carbon black, graphite powder, iron oxide Powder, lead oxide, silver oxide, chromium oxide, iron sulfide,
Chromium sulfide, metal powder, and the like. Particularly preferred are organic light-to-heat conversion compounds, among which wavelength 760.
Dyes and pigments that effectively absorb infrared rays from nm to 1200 nm, that is, IR dyes.

As the dye used in the present invention, commercially available dyes and known dyes described in literatures (for example, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, published in 1970) can be used. Specifically, azo dyes, metal complex salt azo dyes,
Dyes such as a pyrazolone azo dye, an anthraquinone dye, a phthalocyanine dye, a carbonium dye, a quinone imine dye, a methine dye, a cyanine dye, and a metal thiolate complex are exemplified. Preferred dyes include, for example, those described in
Cyanine dyes described in JP-A-125246, JP-A-59-84356, JP-A-59-202829 and JP-A-60-78787.
6, JP-A-58-181690, JP-A-58-19
Methine dyes described in JP-A No.
Naphthoquinone described in JP-A-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744 and the like. Dye, JP-A-58-11
For example, squarylium dyes described in No. 2792 and cyanine dyes described in British Patent No. 434,875 can be exemplified.

Also, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also preferable. Pyrylium salt, JP-A-57-142645
No. (U.S. Pat. No. 4,327,169) described in JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, and JP-A-59-41363.
Nos. -84248, 59-84249, 59-14
Nos. 6063 and 59-146061, pyranyl compounds, cyanine dyes described in JP-A-59-216146, pentamethinethiopyrylium salts described in U.S. Pat. No. 4,283,475, and the like. Fairness 5-13
Pyrylium compounds disclosed in JP-A-514 and JP-A-5-19702 are also preferably used. Another preferred example of the dye is U.S. Pat. No. 4,756,993.
Near-infrared absorbing dyes described in the specification as formulas (I) and (II) can be mentioned. Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes.

Examples of the pigment used in the present invention include commercially available pigments and Color Index (CI) Handbook, "Latest Pigment Handbook" (edited by Japan Pigment Technical Association, 1977),
"Latest Pigment Application Technology" (CMC Publishing, 1986),
Pigments described in "Printing Ink Technology" published by CMC, 1984) can be used. Examples of the type of the pigment include a black pigment, a yellow pigment, an orange pigment, a brown pigment, a red pigment, a violet pigment, a blue pigment, a green pigment, a fluorescent pigment, a metal powder pigment, and a polymer-bound pigment. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelated azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments , Quinophthalone pigments,
Dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like can be used. Preferred among these pigments is carbon black.

These pigments may be used without surface treatment, or may be used after surface treatment. Methods of surface treatment include a method of surface coating a resin or wax, a method of attaching a surfactant, and a reactive substance (for example, a silane coupling agent, an epoxy compound, or a polyisocyanate).
Can be conceived on the surface of the pigment. The above surface treatment methods are described in "Properties and Applications of Metallic Soap" (Koshobo),
"Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986)
It is described in.

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm.
Is preferably within the range. Pigment particle size 0.01μ
If it is less than m, it is not preferable in terms of stability of the dispersion in the coating solution of the sensitive composition, and if it exceeds 10 μm, it is not preferred in terms of uniformity of the sensitive layer after coating. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Dispersers include ultrasonic dispersers, sand mills, attritors, pearl mills,
Examples include a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Application Technology" (CMC Publishing, 1986).

These dyes and pigments are used in an amount of 0.01 to 50% based on the total solid content of the metal oxide composition containing the photothermal conversion compound.
%, Preferably 0.1 to 10% by weight, particularly preferably 0.5 to 10% by weight for dyes, and particularly preferably 1.0 to 10% by weight for pigments. If the amount of the pigment or dye is less than 0.01% by weight, the light-to-heat conversion effect will be poor, and if it exceeds 50% by weight, it will not be included in the metal oxide.

Among the organic light-to-heat conversion compounds included in the metal oxide, particularly preferred dyes are water-soluble dyes or solvents having high solubility in water such as acetone, THF, methanol, ethanol, isopropanol, methyl ethyl ketone and acetonitrile. It is a soluble dye. Specific examples include the following dyes, but the dye used in the present invention is not limited to these.

[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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The size of the metal compound particles enclosing the photothermal conversion material used in the present invention is 0.001 to 20 μm,
Preferably 0.01-5 μm, more preferably 0.05
２2 μm. If the particle size is too small, no effect will be exhibited, and if it is too large, the resolution will be poor.

[Other components that can be added to the metal oxide particles] In order to increase the compatibility between the dye and the metal oxide, a known compatibilizer polymer which can increase the compatibility between the dye and the metal oxide can be used. Known compatibilizer polymers include: Yoshiki Nakajo Chemical and Industry 46, p1567, polyoxazoline polymer, polyvinylpyrrolidone, as described in 1993,
Polyacrylamide derivative polymers can be mentioned. Further, a polar group-containing organic polymer described in JP-A-8-262700 can be used. The amount of the compatibilizer polymer that can be added is in the range of 0.5 to 70% by weight, preferably 1 to 50% by weight, more preferably 5 to 30% by weight, based on the metal oxide.
In the range of 0.5 wt% or less, no effect is exhibited. 7
Above 0 wt%, no metal oxide is formed.

2. Binder In the present invention, the binder is a crosslinked compound having a functional group that changes from hydrophobic to hydrophilic by an acid, radiation or heat. Here, the change from hydrophilic to hydrophobic refers to a change in hydrophilicity to a certain degree that is capable of exhibiting a function as a printing surface of a lithographic printing plate, and reduces the air contact angle of a compound by 15 ° or more. It is preferred that That is, as this compound, the contact angle of a water drop in the air is 15 ° by the action of an acid, radiation or heat.
It is preferable that the above decrease is such that what was initially hydrophobic becomes hydrophilic. Further, as this compound, it is more preferable that the compound has a contact angle of a water drop in the air of 40 ° or more. In addition, as the compound, specifically, the compound having a contact angle of water droplets in the air of 60 ° or more at the beginning is changed to 20 ° by the action of acid, radiation or heat.
It is preferable that the temperature be reduced to the following.

In the present invention, any compound having the above properties can be preferably used as a binder. Such a compound can be used as a crosslinking system by photocrosslinking, photopolymerization and photodecomposition polymerization (condensation). Compounds crosslinked by any of the above are preferably used. The compound crosslinked by the photocrosslinking reaction is crosslinked by photodimerization or photoradical polymerization. That is, a crosslinking reactive group is incorporated into the polymer compound, and the polymer compound is crosslinked by itself or by reaction with a monomer. In the photodimerization reaction, a crosslinking reaction can be caused by light absorption of its own functional group or irradiation with light using a photosensitizer. In addition, photoradical polymerization crosslinking can cause a crosslinking reaction by light irradiation using a well-known photopolymerization initiator.

The polymer crosslinked by the photocrosslinking reaction can be obtained by copolymerizing a monomer having a photocrosslinkable functional group, also called a photocurable functional group, and a monomer having a group whose hydrophilicity changes by heat. I can do it. "Photocurable functional group"
The term “functional group” refers to a functional group that causes a curing reaction of a resin by light.
Specific examples of photocurable functional groups include Hideo Inui, Mototaro Nagamatsu, "Photosensitive Polymers" (Kodansha, 1977), Takahiro Tsunoda, "New Photosensitive Resins" (Printing Society Press, 1981),
GEGreen and BPStrak, J. Macro. Sci. Reas. Macr
o. Chem., C21 (2), 187-273 (1981-82), CGRattey
`` Photopolymerization of Surface Coatings '' (A.Wile
y Inter Science Pub. 1982) and the like, as the photocurable resin, functional groups used in conventionally known photosensitive resins and the like are used.

For example, polymerizable double bond group, photocrosslinkable double bond
Examples include a bonding group. As a polymerizable double bond group
And specifically CH_Two= CH-, CH_Two= CHCH_Two−,
CH_Two= CHCOO-, CH_Two= C (CH_Three) COO-, C
(CH_Three) H = CHCOO-, CH_Two= CHCONH-,
CH_Two= C (CH_Three) CONH-, C (CH_Three) H = CHC
ONH-, CH_Two= CHOCO-, CH_Two= C (CH_Three) O
CO-, CH_Two= CHCH_TwoOCO-, CH_Two= CHNH
CO-, CH_Two= CHCH_TwoNHCO-, CH _Two= CHS
O_Two-, CH_Two= CHCO-, CH_Two= CHO-, CH_Two=
CHS-, and the like. light
As the crosslinkable double bond group, specifically, -CH = CH-,
-C (CH_Three) = C (CH_Three)-. When
1,2-dimethyl-maleimide group, vinylphenyl
Groups are examples of preferred functional groups.

The compound crosslinked by the photopolymerization reaction is
Specifically, Japanese Patent Application Laid-Open No. 10-282672 discloses 4-19.
It is a polymer compound obtained by polymerizing a monomer having a functional group that changes from hydrophobic to hydrophilic by an acid, radiation or heat as described on the page by photoradical polymerization.

As a specific example of the polymer compound polymerized and crosslinked by photopolymerization, preferably, a “sulfonic acid ester group and / or an alkoxyalkyl ester group”, that is, a compound having a functional group X is used.

First, specific examples of the functional group X will be described in detail. The sulfonic acid ester group can be represented by the following general formula (2).

[0049]

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In the formula, L ² represents an organic group comprising a polyvalent nonmetallic atom necessary for connecting the functional group represented by the general formula (2) to the polymer skeleton, and R ₁₁ represents a substituted or unsubstituted group. It represents an aryl group, a substituted or unsubstituted alkyl group or a cyclic imide group.

When R ₁₁ represents an aryl group or a substituted aryl group, the aryl group includes a carbocyclic aryl group and a heterocyclic (hetero) aryl group. As the carbocyclic aryl group, those having 6 to 19 carbon atoms such as a phenyl group, a naphthyl group, an anthracenyl group and a pyrenyl group are used. Examples of the heterocyclic aryl group include a pyridyl group, a furyl group, and other quinolyl groups in which a benzene ring is fused, a benzofuryl group, a thioxanthone group, and a carbazole group. Things are used. When R ₁₁ represents an alkyl group or a substituted alkyl group, a methyl group as the alkyl group, an ethyl group, an isopropyl group, t- butyl group, and cyclohexyl group linear, from 1 carbon atoms branched or cyclic 25
Are used.

When R ₁₁ is a substituted aryl group, a substituted heteroaryl group or a substituted alkyl group, examples of the substituent include an alkoxy group having 1 to 10 carbon atoms such as a methoxy group and an ethoxy group, a fluorine atom, a chlorine atom and a bromine. A carbon atom 2 such as a halogen atom such as an atom, a halogen-substituted alkyl group such as a trifluoromethyl group or a trichloromethyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a t-butyloxycarbonyl group, a p-chlorophenyloxycarbonyl group; A hydroxyl group; an acyloxy group such as an acetyloxy group, a benzoyloxy group, a p-diphenylaminobenzoyloxy group; a carbonate group such as a t-butyloxycarbonyloxy group; t-butyl Oxycarbonylmethyl Ether groups such as xy group and 2-pyranyloxy group; substituted and unsubstituted amino groups such as amino group, dimethylamino group, diphenylamino group, morpholino group and acetylamino group; thioether groups such as methylthio group and phenylthio group; vinyl An alkenyl group such as a group or styryl group; a nitro group; a cyano group; an acyl group such as a formyl group, an acetyl group or a benzoyl group; an aryl group such as a phenyl group or a naphthyl group; and a heteroaryl group such as a pyridyl group. be able to. When R ₁₁ is a substituted aryl group or a substituted heteroaryl group, an alkyl group such as a methyl group or an ethyl group can be used as the substituent other than the above.

When R ₁₁ represents a cyclic imide group, those having 4 to 20 carbon atoms such as succinimide, phthalic imide, cyclohexanedicarboxylic imide and norbornenedicarboxylic imide can be used as the cyclic imide. .

Of the above, R ₁₁ is particularly preferably an aryl group substituted with an electron-withdrawing group such as halogen, cyano or nitro, an alkyl group substituted with an electron-withdrawing group such as halogen, cyano or nitro. They are a secondary or tertiary branched alkyl group, a cyclic alkyl group and a cyclic imide.

The polyvalent linking group consisting of a nonmetallic atom represented by L ² is a group consisting of 1 to 60 carbon atoms, 0 to 1
0 nitrogen atoms, 0 to 50 oxygen atoms,
It is composed of 1 to 100 hydrogen atoms and 0 to 20 sulfur atoms. More specific linking groups include those constituted by combining the following structural units.

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When the polyvalent linking group has a substituent, examples of the substituent include an alkyl group having 1 to 20 carbon atoms such as a methyl group and an ethyl group, and a carbon atom having 6 carbon atoms such as a phenyl group and a naphthyl group.
To 16 aryl groups, hydroxyl groups, carboxyl groups,
C1-C6 acyloxy groups such as sulfonamide groups, N-sulfonylamido groups, and acetoxy groups; C1-C6 alkoxy groups such as methoxy groups and ethoxy groups; halogens such as chlorine and bromine. An atom, a methoxycarbonyl group, an ethoxycarbonyl group, an alkoxycarbonyl group having 2 to 7 carbon atoms such as a cyclohexyloxycarbonyl group, a cyano group, a carbonate group such as t-butyl carbonate, or the like can be used.

The alkoxyalkyl ester group can be represented by the following general formula (3).

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In the formula, R ₂₁ represents a hydrogen atom, R ₂₂ represents a hydrogen atom or an alkyl group having 18 or less carbon atoms, and R ₂₃ represents an alkyl group having 18 or less carbon atoms. Also, R ₂₁ , R
It may be formed between two members to out of ₂₂ and R _23. In particular, it is preferred that R ₂₂ and R ₂₃ combine to form a 5- or 6-membered ring.

In the present invention, as the functional group X, those represented by the above general formula (2) or (3) can be mentioned. Particularly preferred is a sulfonic acid ester group represented by the general formula (2). is there.

Specific examples of the monomer having a functional group represented by the general formula (2) or (3), which is preferably used for the synthesis of the binder in the present invention, are shown below.

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As the binder, a polymer compound obtained by subjecting at least one of the monomers having a functional group represented by the above general formula (2) or (3) to radical polymerization is preferable. Use As such a polymer compound, a homopolymer using only one kind of a monomer having a functional group represented by the general formula (2) or (3) may be used, but a copolymer using two or more kinds may be used. Copolymers of these monomers and other monomers may be used.

As the other monomer, a monomer having a crosslinking reactivity such as glycidyl methacrylate, N-methylol methacrylamide, 2-isocyanate ethyl acrylate and the like is preferable. Further, as other monomers used in the copolymer, for example, acrylates, methacrylates, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid,
Known monomers such as methacrylic acid, acrylonitrile, maleic anhydride, and maleic imide are also included.

Specific examples of acrylates include:
Methyl acrylate, ethyl acrylate, (n- or i-) propyl acrylate, (n-, i-, sec-
Or t-) butyl acrylate, amyl acrylate,
2-ethylhexyl acrylate, dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
5-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, chlorobenzyl acrylate, hydroxybenzyl acrylate, hydroxyphenethyl acrylate, dihydroxyphenethyl acrylate, furfuryl acrylate, Examples thereof include tetrahydrofurfuryl acrylate, phenyl acrylate, hydroxyphenyl acrylate, chlorophenyl acrylate, sulfamoylphenyl acrylate, and 2- (hydroxyphenylcarbonyloxy) ethyl acrylate.

Specific examples of methacrylates include methyl methacrylate, ethyl methacrylate,
(N- or i-) propyl methacrylate, (n-, i
-, Sec- or t-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate,
Dodecyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate,
Glycidyl methacrylate, benzyl methacrylate,
Methoxybenzyl methacrylate, chlorobenzyl methacrylate, hydroxybenzyl methacrylate, hydroxyphenethyl methacrylate, dihydroxyphenethyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, hydroxyphenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate, 2- (hydroxyphenyl Carbonyloxy) ethyl methacrylate and the like.

Specific examples of acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide,
Hydroxyethylacrylamide, N-phenylacrylamide, N-tolylacrylamide, N- (hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl)
Acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-
N-phenylacrylamide, N-hydroxyethyl-
N-methylacrylamide and the like can be mentioned.

Specific examples of methacrylamides include methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide, N-propyl methacrylamide, N-butyl methacrylamide, N-benzyl methacrylamide, N-hydroxyethyl methacryl Amide,
N-phenylmethacrylamide, N-tolylmethacrylamide, N- (hydroxyphenyl) methacrylamide, N- (sulfamoylphenyl) methacrylamide, N- (phenylsulfonyl) methacrylamide, N
-(Tolylsulfonyl) methacrylamide, N, N-dimethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide and the like.

Specific examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate and the like.

Specific examples of styrenes include styrene,
Methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, propylstyrene, cyclohexylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, acetoxymethylstyrene, methoxystyrene, dimethoxystyrene,
Chlorostyrene, dichlorostyrene, bromostyrene,
Examples thereof include iodostyrene, fluorostyrene, carboxystyrene and the like.

Of these other monomers, particularly preferred are those having 20 or less carbon atoms, such as acrylates, methacrylates, acrylamides, methacrylamides, vinyl esters, styrenes, and acrylic acid. , Methacrylic acid, and acrylonitrile.

The general formula (2) used for the synthesis of the copolymer
Alternatively, the proportion of the monomer having a functional group represented by (3) is preferably from 5 to 99% by weight, more preferably from 10 to 95% by weight, based on the entire monomer.

Next, the binder crosslinked by photolytic polymerization used in the present invention will be described. A particularly preferred example of the binder is the compound A. Compound A refers to “—OH, —NH ₂ , —COO” together with the aforementioned functional group X.
_{H, -NH-CO-R 3} , -Si (OR 4) 3 [ wherein R
₃ and R ₄ represent an alkyl group or an aryl group. When both R ₃ and R ₄ are present in the compound having these functional groups, they may be the same or different. At least one functional group selected from the group consisting of
That is, the compound has the functional group Y in the same molecule.

Next, specific examples of the functional group Y will be described in detail. When the functional group Y is —NH—CO—R ₃ and / or —Si (OR ₄ ) ₃ , R ₃ and R ₄ are preferably an alkyl group having 1 to 10 carbon atoms or 6 to 20 carbon atoms. Which may be substituted with a halogen such as chloro, an alkoxy group such as a methoxy group, or an alkoxycarbonyl group such as a methoxycarbonyl group. Specific examples of -NH-CO-R _3,
-NH-CO-CH _3, can be mentioned -NH-CO-C ₂ H ₅ and the like. Further, -Si Examples of (OR _{4) 3 is, -Si (OCH 3) 3,} -Si (OC
₂ H ₅ ) _{3 and the} like.

The compound A used in the present invention comprises a functional group X, preferably a monomer having a functional group represented by formula (2) or (3), and a functional group Y. A polymer compound obtained by radical polymerization of a monomer having the polymer is used. As such a compound A, a copolymer using only one of the monomers having the functional group represented by the general formula (2) or (3) and only one of the monomers having the functional group Y described above. A combination may be used, but a copolymer using two or more of both monomers, or one of the monomers, or a copolymer of these monomers and another monomer may be used. Other monomers are the same as those described as monomers copolymerizable with the monomer having the functional group X.

The mixing ratio of the monomer having the functional group X and the monomer having the functional group Y used in the synthesis of the copolymer is preferably from 10:90 to 99: 1 by weight, The ratio is more preferably 30:70 to 97: 3. When a copolymer with another monomer is used, the ratio of the other monomer to the total of the monomer having the functional group X and the monomer having the functional group Y used in the synthesis of the copolymer is 5 to 5. It is preferably 99% by weight, more preferably 10 to 95% by weight.

Hereinafter, specific examples of the polymer compound used as a binder in the present invention including the compound A will be shown. In addition,
The numerical value at the lower right of the parenthesis in the chemical formula indicates the copolymerization ratio.

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[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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[Hydrolytic Polymerizable Compound] Next, the hydrolytic polymerizable compound used in the present invention will be described. The hydrolyzable polymerizable compound used in the present invention is a compound represented by the following general formula (1).

Formula (1) (R ₁ ) _n -X- (OR ₂ ) _{4-n In the} formula, R ₁ and R ₂ may be the same or different, and represent an alkyl group or an aryl group. X is Si,
Represents Al, Ti or Zr, and n represents an integer of 0 to 2. When R ₁ or R ₂ represents an alkyl group, it preferably has 1 to 4 carbon atoms. Further, the alkyl group or the aryl group may have a substituent. This compound is a low molecular compound and preferably has a molecular weight of 1,000 or less.

Examples of the compound containing aluminum in the hydrolyzable polymerizable compound include trimethoxyaluminate, triethoxyaluminate, tripropoxyaluminate and tetraethoxyaluminate. Examples of those containing titanium include, for example, trimethoxy titanate, tetramethoxy titanate, triethoxy titanate, tetraethoxy titanate, tetrapropoxy titanate, chlorotrimethoxy titanate,
Chlorotriethoxytitanate, ethyltrimethoxytitanate, methyltriethoxytitanate, ethyltriethoxytitanate, diethyldiethoxytitanate,
Examples include phenyltrimethoxytitanate and phenyltriethoxytitanate. As a material containing zirconium, for example, a zirconate corresponding to the material containing titanium can be given.

Examples of compounds containing silicon in the hydrolyzable polymerizable compound include trimethoxysilane, triethoxysilane, tripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and the like.
Methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, γ-chloropropyltriethoxysilane, γ-mercapto Propyltrimethoxysilane, γ-
Mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like can be given. Of these, particularly preferred are tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, dimethyldiethoxysilane,
Examples thereof include phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like.

The hydrolyzable polymerizable compound may be used alone or in combination of two or more. After partial hydrolysis, dehydration condensation may be performed. In order to adjust the physical properties of the product, a trialkylmonoalkoxysilane can be added as needed. The hydrolyzable polymerizable compound is a compound constituting an inorganic phase in the image forming material of the present invention, but in order to enhance the storage stability in a solution state of the image forming material before being applied to a lithographic printing plate precursor. Further, it is effective to protect the active metal hydroxyl group, for example, a silanol group (Si-OH) of the inorganic polymer obtained by partially hydrolyzing and polymerizing the hydrolyzable polymerizable compound. The silanol group is protected by esterifying the silanol group with a higher alcohol such as t-butanol or i-propyl alcohol (S
i-OR). Specifically, it can be carried out by adding the higher alcohol to the inorganic phase. At this time, depending on the properties of the inorganic phase, the storage stability can be further improved by dehydrating the inorganic phase by, for example, heating the inorganic phase and distilling off the water desorbed. When acids or bases that can serve as a catalyst for the hydrolysis polymerization, such as hydrochloric acid and ammonia, are present in the inorganic phase, it is generally effective to lower their concentration. These can be easily carried out by neutralizing the inorganic phase with an acid or a base.

The hydrolyzable polymerizable compound is preferably used in an amount of 3 to 95% by weight, more preferably 10 to 80% by weight, based on the total solid content of the sensitive layer.

3. Other Components of Radiation-Sensitive Layer (1) Water-Insoluble Solid Particles Next, although not a necessary component of the components of the radiation-sensitive printing original plate of the present invention, adjustment of the physical strength and hydrophilicity of the sensitive layer. The water-insoluble solid particles that may be used for other purposes will be described. Water-insoluble solid particles include inorganic particles,
It is at least one kind of solid particles selected from the group consisting of organic particles and metal particles.

As the water-insoluble solid particles, granules having good affinity and adhesion to the binder and improving the water retention are preferable. Particles surface-treated to improve dispersibility may be used. These inorganic particles, organic particles and metal particles may be used in an appropriate combination.

Examples of the inorganic particles include metal oxides such as iron oxide, zinc oxide, titanium dioxide and zirconia;
Silicon-containing oxides, such as anhydrous silicic acid, hydrous calcium silicate, and hydrous aluminum silicate, which are themselves also called white carbons having no absorption in the visible region; clays,
Clay mineral particles such as talc, kaolin, and fluorite can be used. Further, as the metal particles, for example, iron, aluminum, copper, nickel, silver and the like can be used.

The average particle diameter of the inorganic particles or metal particles is as follows:
About 10 μm or less, preferably 0.01 to 10 μm,
0.1-5 μm is more preferable. When the average particle diameter of the inorganic particles or the metal particles is less than 0.01 μm, the water-retention of the laser-irradiated portion becomes insufficient, and the soil becomes liable to occur.
If it exceeds 10 μm, the resolution of the printed matter will be poor, the adhesion to the support will be poor, and particles near the surface will be easily removed.

When the inorganic particles or metal particles are added to the sensitive layer, the content thereof is 2 parts based on the total solid content of the sensitive layer.
About 90% by volume, preferably 5 to 80% by volume,
10 to 50% by volume is more preferred. Content is 2% by volume
If it is less than, the water-retained portion of the radiation-sensitive lithographic printing plate surface at the laser-irradiated portion becomes insufficient, and soiling is likely to occur. If the content exceeds 90% by volume, the strength of the coating film is reduced and the printing durability is reduced, and the adhesion between the coating film layer and the support is reduced.

The organic particles are not particularly limited as long as they enhance water retention, but resin particles can be used as the organic particles. The following precautions need to be taken during use: When a solvent is used for dispersing the resin particles, it is necessary to select resin particles that do not dissolve in the solvent or conversely, select solvents that do not dissolve the resin particles. Further, when the resin particles are dispersed in the coating solution of the coating film using a thermoplastic polymer, the resin particles are melted by heat at the time of dispersing, or deformed, or a material that does not decompose is selected. There is a need. Crosslinked resin particles can be preferably used to reduce these cautions.

The average particle size of the organic particles is 0.01 to 1
About 0 μm, preferably 0.05 to 10 μm,
0.1-5 μm is more preferable. When the average particle size of the organic particles is less than 0.01 μm, the water retention of the laser-irradiated portion becomes insufficient, and the background fouling easily occurs. On the other hand, 10 μm
When the ratio exceeds the above range, the resolution of the printed matter becomes poor, the adhesiveness between the sensitive layer and the support is easily reduced, and particles near the surface are easily removed.

When the organic particles are added to the sensitive layer,
The content thereof is about 3 to 70% by volume, preferably 5 to 60% by volume, and more preferably 10 to 50% by volume based on the total solid content of the sensitive layer.
% By volume is more preferred. If the content of the particles is less than 3% by volume, sufficient water retention cannot be obtained, and background fouling is likely to occur. If it exceeds 70% by volume, the strength of the sensitive layer is reduced and the printing durability is reduced, and the adhesiveness between the sensitive layer and the support is apt to be reduced.

As the organic particles, polystyrene particles (particle diameter 4 to 10 μm), silicone resin particles (particle diameter 2 to 2)
4 μm). Examples of the crosslinked resin particles include a microgel (particle diameter: 0.01 to 1 μm) composed of two or more ethylenically unsaturated monomers and a crosslinked resin particle composed of styrene and divinylbenzene (particle diameter: 4 to 4 μm).
10 μm), crosslinked resin particles composed of methyl methacrylate and diethylene glycol dimethacrylate (particle size: 4 to
10 μm) etc., that is, microgel of acrylic resin,
Crosslinked polystyrene and crosslinked methyl methacrylate are exemplified. These organic particles are prepared by a general method such as an emulsion polymerization method, a soap-free emulsion polymerization method, a seed emulsion polymerization method, a dispersion polymerization method, and a suspension polymerization method.

It is also possible to prepare inorganic particles from a solution. For example, a metal lower alkoxide is added to a solvent such as ethanol, and inorganic particles containing the metal are obtained in the presence of water and an acid or alkali. The resulting inorganic particle solution can be added to a solvent-soluble thermoplastic polymer solution to prepare an inorganic particle dispersion. Alternatively, the metal lower alkoxide is first added to the thermoplastic polymer solution, and then water and an acid or alkali are added,
It is also possible to obtain inorganic particles containing the metal. When inorganic particles are produced by adding a metal lower alkoxide to a thermoplastic polymer precursor solution, a polymer-inorganic composite is obtained when the thermoplastic polymer precursor is converted into a thermoplastic polymer precursor by heat. . As the metal lower alkoxide, tetraethoxysilane, tetraethoxytitanium and the like can be used.

(2) Acid Generator In the present invention, it is not necessary to use an acid generator in particular.
It is preferable to use it when it is desired to further increase the sensitivity, that is, the sensitivity of the polarity conversion. An acid generator is a compound that generates an acid by heat or light, and is generally a photopolymerization initiator for photocationic polymerization, a photopolymerization initiator for photoradical polymerization,
Photo-decoloring agents for dyes, photo-discoloring agents, known light-generating compounds used in micro resists and the like, and compounds and mixtures thereof can be used, and these can be appropriately selected and used. it can.

For example, see SISchlesinger, Photogr. Sci.
Eng., 18,387 (1974), TSBal et al., Polymer, 21,4.
Diazonium salts described in U.S. Pat.
Ammonium salts described in 9,055, 4,069,056 and JP-A-3-140,140, DCNecker et al., Macromolecu
les, 17,2468 (1984), CSWen et al., Teh, Proc.Con
f. Rad.Curing ASIA, p478, Tokyo, Oct (1988), U.S. Pat.Nos. 4,069,055, 4,069,056, etc., and phosphonium salts described in JVCrivello et al., Macromolecules, 10
(6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1
988), EP 104,143, U.S. Patent 339,049
No. 410,201, JP-A-2-150,848, JP-A-2-29
No. 6,514, etc., iodonium salts, JVCrivello et
al., Polymer J. 17, 73 (1985), JVCrivello et al.,
J. Org. Chem., 43, 3055 (1978), WRWatt et al., J. Po.
lymer Sci., Polymer Chem. Ed., 22, 1789 (1984), J.
V. Crivello et al., Polymer Bull., 14,279 (1985), J.
V. Crivello et al., Macromolecules, 14 (5), 1141 (198
1), JVCrivello et al., J. Polymer Sci., Polymer C
hem. Ed., 17,2877 (1979), European Patent No. 370,693, U.S. Patent No. 3,902,114, European Patent Nos. 233,567, 297,
443, 297,442; U.S. Patents 4,933,377, 41
0,201, 339,049, 4,760,013, 4,734,44
No. 4, No. 2,833,827, German Patent No. 2,904,626, No. 3,
Sulfonium salts described in Nos. 604,580 and 3,604,581, JVCrivello et al., Macromolecules, 10 (6), 13
07 (1977), JVCrivello et al., J. Polymer Sci., Pol
selenonium salts described in Ymer Chem. Ed., 17, 1047 (1979), etc., CSWen et al., Teh, Proc. Conf. Rad. Curing
Onium salts such as arsonium salts described in ASIA, p478, Tokyo, Oct (1988), etc.

US Pat. No. 3,905,815, JP-B-46-4605
No., JP-A-48-36281, JP-A-55-32070, JP-A-60-2
39736, JP-A-61-169835, JP-A-61-169837,
JP-A-62-58241, JP-A-62-212401, JP-A-63-702
No. 43, organic halogen compounds described in JP-A-63-298339, etc., K. Meier et al., J. Rad.Curing, 13 (4), 26 (198
6), TPGill et al., Inorg. Chem., 19,3007 (1980),
D. Astruc, Acc. Chem. Res., 19 (12), 377 (1896), organometallics / organic halides described in JP-A-2-14145 and the like,
S. Hayase et al., J. Polymer Sci., 25, 753 (1987), E.
Reichman et al., J. Polymer Sci., Poliymer Chem. E
d., 23, 1 (1985), QQZhu et al., J. Photochem., 36,
85, 39, 317 (1987), B. Amit et al., Tetrahedron Le
tt., (24) 2205 (1973), DHR Barton et al., J. Chem.
Soc., 3571 (1965), PMCollins et al., J. Chem. So
c., Perkin I, 1695 (1975), M. Rudinstein et al., Te
trahedron Lett., (17), 1445 (1975), JWWalker et a
l., J. Am. Chem. Soc., 110, 7170 (1988), SCBusman
et al., J. Imaging Technol., 11 (4), (1985), HMH
oulihan et al., Macromolecules, 21, 2001 (1988), P.
M. Collins et al., J. Chem. Soc., Chem. Commun., 532
(1972), S. Hayase et al., Macromolecules, 18,1799 (1
985), E. Reichmanis et al., J. Electrochem. Soc., So
lid State Sci. Technol., 130 (6), FMHoulihan et
al., Macromolecules, 21, 2001 (1988), EP 029.
0,750, 046,083, 156,535, 271,851
No. 0,388,343, U.S. Pat.Nos. 3,901,710, 4,18
No. 1,531, JP-A-60-198538, JP-A-53-133022, etc., a photoacid generator having a 0-nitrobenzyl-type protecting group, TUNOOKA et al., Polymer Preprints Japan, 35
(8), G. Berner et al., J. Rad. Curing, 13 (4), WJM
ijs et al., Coating Technol., 55 (697), 45 (1983), A
kzo, H. Adachi et al., Polymer Preprints, Japan, 37
(3), European Patent Nos. 0199,672, 84515, and 199,672
No. 044,115, No. 0101,122, U.S. Pat.No. 4,618,55
No. 4, No. 4,371,605, No. 4,431,774, JP-A-64-181
No. 43, compounds disclosed in JP-A-2-245756, JP-A-3-140109, etc., which generate sulfonic acid by photolysis, such as iminosulfonates, and disulfones described in JP-A-61-166544. Compounds can be mentioned.

Compounds in which an acid generator is introduced into the main chain or side chain of a polymer, for example, MEWoodhouse et al., J. Am.
Am. Chem. Soc., 104, 5586 (1982), SPPappas et a
l., J. Imaging Sci., 30 (5), 218 (1986), S. Kondo et.
al., Makromol. Chem. RapidCommun., 9,625 (1988),
Y. Yamada et al., Makromol, Chem. 152, 153, 163 (197
2), JVCrivello et al., J. Polymer Sci., Polymer
Chem. Ed., 17,3845 (1979), U.S. Pat.
No., German Patent No. 3914407, JP-A-63-26653, JP-A-55
-164824, JP-A-62-69263, JP-A-63-14603, JP-A-63-163452, JP-A-62-153853, JP-A-63-146
Compounds described in No. 029 and the like can be used. Furthermore, VNRPillai, Synthesis, (1), 1 (1980), A. Abad
et al., Tetrahedron Lett., (47) 4555 (1971), DHR
Compounds that generate an acid by light described in Barton et al., J. Chem. Soc., (C), 329 (1970), U.S. Pat. No. 3,779,778, and EP 126,712 can also be used.

In the present invention, when these acid generators are used, the content thereof is usually about 40% by weight or less, preferably 20% by weight or less, more preferably 5% by weight, based on the total solid content of the sensitive layer. It is used in the following range. If the content of the acid generator exceeds 40% by weight, printing stains are likely to occur, which is not preferable.

(3) Dyes, sensitizing dyes, etc. In the photosensitive layer of the photosensitive lithographic printing plate of the present invention, various compounds other than those described above may be added as necessary in order to obtain various lithographic printing plate characteristics. You may. For example, when the acid generator does not have sensitivity up to the visible range, various sensitizing dyes of the acid generator are used to activate the acid generator with respect to light in the visible light range. Examples of such sensitizing dyes include US5238
No. 782, a cyanine dye described in US Pat. No. 4,997,745, and a squarium dye, US Pat.
262276, the merocyanine dye, JP-B-8-2
No. 0732, pyrylium dye, Michler's ketone, thioxanthone, ketocoumarin dye, 9-phenylacridine and the like can be used as effective ones. In addition, bis-benzylidene ketone dyes described in US Pat. No. 4,987,230, polycyclic aromatic compounds such as 9,10-diphenylanthracene, and the like can be used. As the other component, for example, a dye having a large absorption in the visible light region can be used as a colorant for an image.

Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 60
3. Oil black BY, oil black BS, oil black T-505 (orient Chemical Industry Co., Ltd.)
Manufactured), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42
535), ethyl violet, rhodamine B (CI1
45170B), malachite green (CI4200
0), methylene blue (CI52015), and the dyes described in JP-A-62-293247. These dyes are preferably added because the image area and the non-image area can be easily distinguished after image formation. The addition amount is 0.01 to 10% by weight based on the total solid content of the sensitive layer.

(4) Other Additives Further, the photosensitive layer of the photosensitive lithographic printing plate of the present invention is prepared in Japanese Patent Application Laid-Open No.
Nonionic surfactants described in JP-A-51740 and JP-A-3-208514;
An amphoteric surfactant as described in JP-A No. 121044 and JP-A-4-13149 can be added. Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride,
And polyoxyethylene nonyl phenyl ether. Specific examples of the amphoteric surfactant include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N
-Tetradecyl-N, N-betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo KK) and the like. The proportion of the nonionic surfactant and the amphoteric surfactant in the radiation-sensitive lithographic printing plate precursor in the sensitive layer is 0.05%.
-15% by weight, more preferably 0.1-5% by weight.

Further, a plasticizer may be added to the sensitive layer of the radiation-sensitive lithographic printing plate precursor of the present invention, if necessary, in order to impart flexibility to the coating film. For example, butyl phthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or Oligomers and polymers of methacrylic acid are used.

Other than these, the above-mentioned onium salts and haloalkyl-substituted s-triazines, epoxy compounds, vinyl ethers, phenol compounds having a hydroxymethyl group, phenol compounds having an alkoxymethyl group, phenol novolak resins, A cresol novolak resin or the like may be added.

The radiation-sensitive lithographic printing plate of the present invention comprises:
Usually, it can be produced by dissolving each of the above components in a solvent and applying it as a sensitive layer on a suitable support.
As the solvent used here, ethylene dichloride,
Cyclohexanone, methyl ethyl ketone, methanol,
Ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-
Methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, Examples include, but are not limited to, γ-butyl lactone, toluene, water, and the like. These solvents are used alone or as a mixture. The concentration of the above components (total solids including additives) in the solvent is preferably 1 to 50% by weight. The amount of coating (solid content) on the support obtained after coating and drying varies depending on the use, but generally, 0.5 to 5.0 g / m ² is preferable for a lithographic printing plate. Various methods can be used as the method of coating, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the image recording film deteriorate.

In the photosensitive layer of the photosensitive lithographic printing plate according to the present invention, a surfactant for improving coating properties, for example, a fluorine-based surfactant described in JP-A-62-170950 is used. Agents can be added. A preferable addition amount is 0.01 to 1% by weight based on the total solid content of the sensitive layer.
More preferably, it is 0.05 to 0.5% by weight.

[Support] The support used in the present invention is a dimensionally stable plate-like material such as paper or plastic (eg, polyethylene, polypropylene, polystyrene, etc.) laminated paper. , Metal plates (eg, aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, Polycarbonate, polyvinyl acetal, etc.), paper or plastic film on which a metal as described above is laminated or vapor-deposited, and the like.

As the support of the present invention, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate which has good dimensional stability and is relatively inexpensive is particularly preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and containing a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in aluminum alloys include silicon, iron, manganese,
Copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. Particularly preferred aluminum in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, particularly preferably 0.2 mm to 0.8 mm.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution is performed to remove rolling oil on the surface. The surface roughening treatment of the surface of the aluminum plate is performed by various methods, for example, a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. It is performed by the method of causing. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. Further, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used. The aluminum plate thus roughened is subjected to an alkali etching treatment and a neutralization treatment, if necessary, and then subjected to an anodic oxidation treatment, if desired, in order to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. Generally, sulfuric acid,
Phosphoric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte.

The conditions of the anodizing treatment vary depending on the electrolyte to be used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C., and the current density is 5 to 60 A. / Dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are appropriate. When the amount of the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image portion of the lithographic printing plate is easily scratched,
So-called "scratch stains" in which ink adheres to scratches during printing are likely to occur. After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment as necessary. U.S. Pat. Nos. 2,7,7
No. 14,066, No. 3,181,461, No. 3,2
There is an alkali metal silicate (e.g., sodium silicate aqueous solution) method as disclosed in U.S. Pat. Nos. 80,734 and 3,902,734. In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated. In addition, potassium fluoride zirconate disclosed in JP-B-36-22063 and U.S. Pat. Nos. 3,276,868 and 4,158,461.
And the method of treating with polyvinyl phosphonic acid as disclosed in JP-A No. 4,689,272.

The radiation-sensitive lithographic printing plate of the present invention comprises:
If necessary, an undercoat layer can be provided on the support.
As the undercoat layer component, various organic compounds are used, for example, carboxymethyl cellulose, dextrin, gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, and phenylphosphonic acid optionally having a substituent Organic phosphonic acids such as naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, phenylphosphoric acid which may have a substituent, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid Organic phosphinic acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, organic phosphinic acid such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and hydrochloric acid of triethanolamine Hydroxy such as salt -Alanine, and hydrochlorides of amines having a group may be used in combination of two or more. The coating amount of the organic undercoat layer is suitably from ² to 200 mg / m ² .

As described above, the lithographic printing original plate of the present invention can be manufactured. The lithographic printing original plate is image-exposed using a light source such as a solid-state laser or a semiconductor laser that emits infrared light having a wavelength of 760 nm to 1200 nm. In the lithographic printing plate of the present invention, a large number of sheets can be printed by mounting the plate on an offset printing machine or the like immediately after laser irradiation.

[Plate making method] Next, a plate making method of the lithographic printing plate precursor will be described. The imagewise exposure of the lithographic printing plate precursor can be used as long as the light source emits active light. A preferred light source emits light in a red light region to an infrared region, and a semiconductor laser and a YAG laser that emit light in this region are particularly preferable. Excimer laser (XeF), He-Cd laser, N ₂ laser, LD pumped Nd; YAG laser internal cavity type SHG
The second harmonic obtained by using a BBO crystal as an external resonator type Fourth-HG, a Q-switched LD-pumped solid-state laser, and a light source for active light other than laser light include:
Xenon discharge lamp, mercury lamp, tungsten lamp, tungsten halogen lamp, xenon arc lamp, fluorescent lamp,
Other ultraviolet light sources can be used.

The writing of an image may be performed by either a surface exposure method or a scanning method. When a surface exposure light source is used, the preferable exposure amount changes depending on the illuminance, but usually, the surface exposure intensity before modulation with a print image is 0.1 to 1.
0 J / cm ² , preferably 0.1 to 1 J / cm 2
More preferably, it is in the range of ² . When the support is transparent, exposure can be performed through the support from the back side of the support. The exposure time can be selected in a wide range as long as a necessary exposure amount is provided. Usually 0.01mse
It is preferable to select the exposure illuminance so that the above-mentioned exposure intensity can be obtained by irradiation for c to 10 minutes, preferably 0.01 msec to 1 minute.

When making a lithographic printing plate, if necessary, a step called "gum-pulling" of applying a surface-regulating solution containing a plate surface protective agent (so-called gum solution) to protect non-image areas is performed. It is. Gum-pulling is a period until printing after plate making to prevent the hydrophilic surface of the lithographic printing plate from being reduced in hydrophilicity by the influence of trace components in the air, and to increase the hydrophilicity of the non-image area. In order to prevent the lithographic printing plate from deteriorating between the time when printing is interrupted and the time when printing is restarted, oil or ink on the fingers may adhere when handling the lithographic printing plate, such as when attaching it to a printing press. In order to prevent non-images from becoming ink-receptive and becoming dirty,
It is performed for various purposes such as to prevent scratches from occurring in the non-image area and the image area when handling a lithographic printing plate.

Preferred examples of the water-soluble resin having a film-forming property used for this purpose include, for example, gum arabic, cellulose derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof. , Polyvinyl alcohol and its derivatives, polyvinylpyrrolidone, polyacrylamide and its copolymer, acrylic acid copolymer, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, styrene / maleic anhydride Copolymer,
Roasted dextrin, oxygen-decomposed dextrin, enzymatically decomposed etherified dextrin and the like can be mentioned.

The content of the water-soluble resin in the protective agent in the surface conditioning solution is suitably from 3 to 25% by weight, and the preferable range is from 10 to 25% by weight. In the present invention, two or more of the above water-soluble resins may be used in combination.

Various surface active agents may be added to the surface protective agent for lithographic printing plates. Surfactants that can be used include anionic or nonionic surfactants. As anionic surfactants, aliphatic alcohol sulfates, tartaric acid, malic acid, lactic acid,
Lepulinic acid, organic sulfonic acid and the like are available, and nitric acid, sulfuric acid, phosphoric acid and the like are useful as mineral acids. At least one kind of a mineral acid, an organic acid or an inorganic salt may be used in combination.

In addition to the above components, if necessary, lower polyhydric alcohols such as glycerin, ethylene glycol and triethylene glycol can be used as wetting agents. The amount of these wetting agents used is 0.1 to 5.0 in the protective agent.
% Is suitable, and a preferred range is 0.5 to 3.0% by weight. In addition to the above, a preservative or the like can be added to the plate surface protective agent for a lithographic printing plate of the present invention. For example, benzoic acid and its derivatives, phenol, formalin, sodium dehydroacetate and the like can be added in the range of 0.005 to 2.0% by weight.

An antifoaming agent may be added to the plate surface protective agent. Preferred antifoaming agents include an organic silicone compound, and the amount added is preferably in the range of 0.0001 to 0.1% by weight.

The plate surface protective agent may contain an organic solvent in order to prevent a decrease in the oil sensitivity of the image area. Preferred organic solvents are hardly water-soluble and have a boiling point of about 120 ° C. to about 250 ° C., such as dibutyl phthalate and dioctyl adipate.
A plasticizer at a temperature of 00 ° C. or higher is used. Such an organic solvent is added in the range of 0.05 to 5% by weight.

The plate surface protective agent can be in any of a uniform solution type, a suspension type and an emulsion type. In particular, the emulsion type containing an organic solvent as described above exhibits excellent performance. In this case, JP-A-55-1
It is preferable to incorporate a surfactant in combination as described in JP-A-05581.

The printing plate which has been image-exposed and, if necessary, subjected to gumming can be mounted on a printing machine for printing. Immediately after exposure (without passing through the developing step), printing can be performed by mounting the plate on a printing press. Or,
It is also possible to form a lithographic printing plate on a printing press by mounting an original printing plate on a printing press and performing image-wise scanning exposure with a laser. That is, in the plate making method using the lithographic printing plate of the present invention, a lithographic printing plate can be made without any particular development processing.

[0132]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples.

[Examples 1 to 4] (Preparation of photothermal conversion agent particles)
The mixture was stirred in a beaker of 1 l for 6 hours at room temperature to prepare a reaction solution containing the organic light-to-heat conversion compound and the metal compound. <Reaction liquid formulation for light-to-heat conversion agent particles 1> IR dye [Exemplified compound (1)] 0.5 g 5 wt% ammonia water 50 g Ethanol 50 g Tetraethoxysilane 5.4 g Next, the reaction liquid was cooled to 40 degrees. Warmed and stirred for 10 hours.
The reaction solution was sealed in a 500 ml cellophane bag and dialyzed against tap water overnight. The resulting dispersion of the gel-structured particles was dried at room temperature using an evaporator to obtain 5.0 g of silica gel particles (light-to-heat conversion agent particles 1) in which a dye was encapsulated. When the particle size was measured using a particle size measuring device (manufactured by Horiba, Ltd., laser diffraction / scattering type particle size distribution measuring device LA-920), the average particle size was 0.4 μm.

The IR dye of the above formulation was changed as described below, and the other methods were the same as above to prepare light-to-heat converter particles 2 to 4 having the following structures. Light-to-heat conversion agent particles Light-to-heat conversion dye Average particle size μm Particle 1 Exemplary compound (1) 0.4 Particle 2 Exemplary compound (2) 1.0 Particle 3 Exemplary compound (3) 2.2 Particle 4 Exemplary compound (4) 8 Next, glass beads were added to each of the photothermal conversion agent particles as a 10% by weight dispersion of methyl ethyl ketone, and dispersed by shaking for 20 minutes using a paint shaker.

(Preparation of Unprocessed Photosensitive Lithographic Printing Plate) <Coating of Sensitive Layer> As a binder, 0.4 g of the exemplified compound 1-11 of the compound A, and Using ethoxysilane: 0.4 g, 40 mg of a 50% phosphoric acid aqueous solution was added to a liquid consisting of 0.6 g of a dispersion of each photothermal conversion agent particle shown in Table 1 above and 1.1 g of methyl ethyl ketone, and added for 10 minutes. Stirred. In addition,
The dispersion of light-to-heat conversion agent particles is a 10% MEK dispersion in which the light-to-heat conversion agent particles are dispersed in methyl ethyl ketone (hereinafter abbreviated as MEK) with a glass shaker using a paint shaker. Each coating solution prepared in this manner is applied to a rod bar #
20 was applied to a PET substrate whose surface had been corona-charged. Table 1 shows the composition of the sensitive layers of the obtained printing original plates A to D.
Shown in

<Sensitive layer composition> (Table 1) Printing original plate Light-to-heat conversion particles Particle addition amount Coating amount after drying (10% methyl ethyl dispersion) A particle 14 g 3.5 g / m ² B particle 24 4 g 3.4 g / M ² C particles 34 g 3.0 g / m ² D particles 44 g 2.8 g / m ²

(Plate making and printing) Obtained printing original plates A to D
Was exposed to an IR laser (beam diameter 30 μm) that emits infrared light having a wavelength of 838 nm. After the exposure, printing was performed as usual on a Lithrone printer without any processing. On this occasion,
It was observed whether or not the image portion of the printed matter was well formed and whether or not the non-image portion was not stained. Table 2 shows the results. At this time, 10,000 good prints were obtained. Also, observe the laser scanning part of the obtained printing plate with a microscope,
The sensitivity was estimated by measuring the obtained line width.
The results are also shown in Table 2. The closer the line width is to the irradiated beam diameter of 30 μm, the higher the sensitivity (sensitivity of polarity conversion) is. However, any line width in the embodiment of the present invention is close to the irradiated beam diameter and is sufficiently high in sensitivity. It is shown that.

(Table 2) Example Printing base plate Image area blurring Non-image area contamination Sensitivity (μm) (after printing 10,000 sheets) (after printing 10,000 sheets) 1 A None None 28 2 B None None 293 C None None 254 D None None 28

[Examples 5 to 9] (Synthesis of crosslinked polymer) <Synthesis of polymer KP-3> Styrenesulfonic acid-1-
Methyl-2-methoxyethyl ester (0.4 mol),
N-[(3-methacryloyloxy) propyl] -2,3
-Dimethylmaleimide (0.1 mol) and 203 g of methyl ethyl ketone were placed in a three-necked flask, and 2.44 g of azobisdimethylvaleronitrile was added under a nitrogen stream at 65 ° C. After stirring at the same temperature for 5 hours, methyl ethyl ketone was distilled off under reduced pressure to obtain a solid. The polymer was found to have an average molecular weight of 25,000 by GPC (polystyrene standard).

<Synthesis of Polymers KP-4 and 5>
Except that N-[(6-methacryloyloxy) hexyl] -2,3-dimethylmaleimide or allyl methacrylic acid was used instead of [(3-methacryloyloxy) propyl] -2,3-dimethylmaleimide It was synthesized in the same manner as in the synthesis of polymer KP-3. In addition, polymer KP
-4, as styrene sulfonic acid ester,
Cyclohexyl styrenesulfonate was used. Polymer KP-4 has an average molecular weight of 56,000 and polymer KP
The average molecular weight of -5 was 19,000.

<Synthesis of Polymer KP-1> N-[(3-
Polymerization was carried out in the same manner as in the synthesis of polymer KP-3, except that 2-methacryloyloxyethyl isocyanate was used instead of [methacryloyloxy) propyl] -2,3-dimethylmaleimide. Next, acrylic acid (0.1 mol) was added to the reaction solution, and the mixture was further heated and stirred for 8 hours. After the reaction, methyl ethyl ketone was distilled off under reduced pressure to obtain a solid. Average molecular weight 2 by GPC (polystyrene standard)
It turned out to be 3,000 polymers.

(Preparation of Support) An aluminum plate (material 1050) having a thickness of 0.30 mm was washed with trichloroethylene and degreased, and then its surface was grained with a nylon brush and a 400 mesh pumicestone-water suspension. Washed well with water. After washing with water The plate was etched by dipping for 9 seconds in a 25% aqueous solution of sodium hydroxide 45 ° C., washed with water and further immersed in a 2% HNO ₃ 20 seconds. At this time, the etching amount of the grained surface was about 3 g / m ² .
Next, this plate was subjected to current density of 1 using 7% H ₂ SO ₄ as an electrolyte.
After 2 to provide a DC anodic oxide film of 4g / m ² at 5A / dm ^2, washed with water and dried.

(Preparation of Printing Base Plate) Solutions of the components shown in Table 3 below were prepared as coating solutions for the image forming layer. This solution was coated on the support prepared as described above,
Dried for 1 minute. Next, a lithographic printing original plate having an image-forming layer photocrosslinked by UV exposure (using a metahalide, 1000 counts) was obtained on the coated product.

(Table 3) [Printing master plate] Used Addition Sensitizer Photothermal conversion particles Coating solvent Polymer Monomer (polymerization initiator) (10% MEK solution) E KP-3 0.4 g None 0.04 g of the following formula (I) Particle 1 0.04g MEK 1.6g F KP-5 0.4g ATMMT 0.2g DMAB 0.04g Particle 1 0.04g MEK 1.6g G KP-1 0.4g ATMMT 0.2g DMAB 0.04g Particle 1 0.04g MEK 1.6g H KP-4 0.4g None The following formula (I) 0.04 g Particle 1 0.04 g MEK 1.6 g I KP-3 0.4 g None The following formula (I) 0.04 g Particle 2 0.04 g MEK 1.6 g , 4'dimethylaminobenzophenone

[0145]

Embedded image

(Plate making and printing) The lithographic printing original plates E to I thus obtained were imagewise exposed to a YAG laser emitting infrared light having a wavelength of 1064 nm in the same manner as in Example 1. A printing test of 20,000 sheets was performed with a printing machine. At this time, it was observed whether the image portion of the printed matter was well formed and whether the non-image portion was not stained. As shown in Table 4, all of the 20,000 sheets of printed matter had no stain on the printed surface, the image was not blurred, and good print quality was maintained.

(Table 4) Example Printed base plate Image part faint Non-image part stain (after printing 20,000 sheets) (after printing 20,000 sheets) 5 E None None 6 F None None 7 G None None 8 H None None 9 I None None

[0148]

The radiation-sensitive lithographic printing plate of the present invention is characterized in that the organic light-to-heat conversion compound in the sensitive layer is encapsulated in the metal oxide and protected, and the binder of the crosslinked polymer compound is used. Due to the combination, the light-to-heat conversion compound is effectively decomposed without decomposing the light-to-heat conversion compound, the sensitivity of the polarity conversion is improved, and printing with no print smear and excellent print quality can be performed. By using this lithographic printing original plate, it is also possible to make a plate directly from digital data of a computer or the like using an infrared laser, which is highly practical.

Claims (1)

[Claims] 1. A radiation-sensitive lithographic printing plate comprising a support having thereon a sensitive layer comprising at least a binder and a light-to-heat conversion agent, wherein the binder is exposed to acid, radiation or heat. Radiation-sensitive, comprising a crosslinked polymer compound having a functional group that changes from hydrophobic to hydrophilic, and wherein the photothermal conversion agent is metal oxide particles containing an organic photothermal conversion compound. Original plate for lithographic printing.