JP2001277741A - Original plate for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for a lithographic printing plate exhibiting good on-press developability including aging by forming an image by a heat and capable of obtaining more printed products. SOLUTION: The original plate for the lithographic printing plate comprises a heat sensitive layer containing a fine particle-like polymer used to form an image, not united by a heat and provided on a hydrophilic support. In this case, the polymer contains a functional group existing in another fine particle- like polymer or a functional group for enabling a reaction with a functional group existing in the other component in the heat sensitive layer. After the support is roughed, the support is preferably an anodized aluminum board. Further, the aluminum board is preferably silicate-treated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a negative type lithographic printing plate precursor comprising a support having a hydrophilic surface and a hydrophilic image forming layer. More specifically, the present invention relates to a lithographic printing plate precursor capable of performing plate making by scanning exposure based on a digital signal and providing a printed matter with high sensitivity and high printing durability and no residual color and stain.

[0002]

2. Description of the Related Art In general, a lithographic printing plate comprises an oleophilic image area for receiving ink during a printing process and a hydrophilic non-image area for receiving fountain solution. As a lithographic printing plate precursor for making such a lithographic printing plate, conventionally, a PS plate in which a lipophilic photosensitive resin layer (ink receiving layer) is provided on a hydrophilic support, is widely used, As a method of making a lithographic printing plate from the lithographic printing plate precursor, usually, a mask is exposed through a lithographic film, and then a non-image portion is dissolved and removed with a developing solution to obtain a desired printing plate.

In recent years, digitization techniques for electronically processing, storing, and outputting image information using a computer have become widespread, and various new image output systems corresponding to such digitization techniques have been put into practical use. It has come to be. Along with this, computer-to-plate (CTP) technology that scans actinic radiation having a high directivity such as laser light in accordance with digitized image information and directly manufactures a printing plate without passing through a lithographic film has been desired. Therefore, obtaining an original plate for a printing plate adapted to this has become an important technical problem.

On the other hand, the plate making process in the conventional PS plate is as follows.
The fact that a step of dissolving and removing non-image areas after exposure is indispensable, and such an additional wet treatment is indispensable. is there. Particularly in recent years, consideration for the global environment has become a major concern of the entire industry. The simplification of processing, dry processing, and non-processing are becoming more desirable than ever, both from the viewpoint of such environmental aspects and the rationalization of the process accompanying the aforementioned digitization. .

[0005] From such a viewpoint, the following method has been proposed as one of the methods for eliminating the conventional processing steps.
That is, using a photosensitive layer capable of removing the non-image portion of the printing plate precursor during a normal printing process, without performing a developing process, after exposure, developing on a printing machine to obtain a final printing plate. It is a way to get. A plate making method of a lithographic printing plate by such a method is called an on-press development method. Specific examples of the method include a method of using a photosensitive layer soluble in a fountain solution and an ink solvent, and a method of mechanically removing the photosensitive layer by contact with an impression cylinder or a blanket cylinder in a printing press. However, when a conventional PS plate is applied to an on-press development printing plate, the photosensitive layer is not fixed even after exposure of the original plate. Or there was a big problem that it had to be stored under constant temperature conditions.

In response to the technical problems as described above, as a method of manufacturing a printing plate by scanning exposure, semiconductor lasers and YAs have recently been used.
Since high-power solid-state lasers such as G lasers have become available at low cost, methods using these lasers have been particularly promising. In the high power density exposure system using these high power lasers, various phenomena different from the photoreaction used in conventional light-sensitive material systems for low to medium power density exposure can be utilized. Specifically, structural changes such as phase changes, morphological changes, etc. can be used in addition to chemical changes. Usually, a recording method using such high power density exposure is called heat mode recording. In a high power density exposure system, the light energy absorbed by the photosensitive material is often converted into heat, and it is believed that the generated heat causes a desired phenomenon.

A great advantage of such a heat mode recording method is that fixing of an image after exposure is not essential. That is, the phenomenon used for image recording of the heat mode photosensitive material is as follows.
Fixation of the image after exposure is not essential since exposure to light of normal intensity and under normal ambient temperatures do not occur substantially. Therefore, for example, using a photosensitive layer that is insolubilized or solubilized by heat mode exposure, and after image exposure, an image obtained even if exposed to ambient light and then developed (removed of non-image areas) for an arbitrary period of time, A system that does not change is possible. Therefore, according to the heat mode recording,
It is also possible to obtain a lithographic printing plate precursor that is desirable for the above-described on-press development system.

[0008] As one of the preferred methods for producing a lithographic printing plate based on heat mode recording, a hydrophilic image forming layer is provided on a hydrophilic support, and is exposed to heat in an image-like manner, and the solubility of the hydrophilic layer is reduced. A method has been proposed in which the dispersibility is changed and, if necessary, the unexposed portions are removed by wet development.
Further, the conventional heat mode type original plate has another serious problem that the non-image portion has poor stainability or the image portion has low strength. In other words, it was necessary to improve the solubility change in the vicinity of the support in the image forming layer due to exposure was smaller than that in the vicinity of the surface of the image forming layer. In the heat mode type master, the amount of heat generated at the time of heat mode exposure is based on the light absorption of the light absorbing agent in the recording layer, so that the amount of generated heat is large on the surface of the recording layer and small near the support. Therefore, the degree of change in solubility of the recording layer in the vicinity of the support becomes relatively small. As a result, in the heat mode negative type master, the ink receiving layer is sometimes removed during the developing and / or printing steps in the exposed area where the hydrophobic ink receiving layer is to be provided. Such removal of the image-area ink-receiving layer in the negative-type master causes a problem that printing durability is poor in terms of printing performance. Particularly, in the case of using a metal support having high thermal conductivity such as Al, which is preferable in terms of printability, heat diffusion further hinders a temperature rise near the support,
The problems described above are significant. In order to obtain a sufficient change in solubility near the substrate, extremely large exposure energy was required, or post-treatment such as heating after exposure had to be performed.

For example, as described in Japanese Patent No. 2938397, an image is formed by thermally fusing thermoplastic hydrophobic polymer fine particles by infrared laser exposure.
There is a method of mounting a printing plate on a printing press cylinder and developing the printing press with a dampening solution and / or ink. However, in such a method of simply forming an image by heat fusion, although good on-press developability is exhibited, when a heat-sensitive layer is directly provided on an aluminum substrate, the generated heat is taken away by the aluminum substrate. No reaction occurs on the interface of the heat-sensitive layer, resulting in insufficient printing durability. Similarly, JP-A-9-
Japanese Patent No. 127683 or WO99 / 10186 also describes that thermoplastic fine particles are heat-sealed and an image is formed by on-press development, but the printing durability similarly becomes insufficient.

As described in JP-A-8-48020, there is a method in which a lipophilic heat-sensitive layer is provided on a porous hydrophilic support, exposed to an infrared laser, and fixed to a substrate by heat. However, the lipophilic film has poor on-press developability, and the residue of the lipophilic heat-sensitive layer adheres to the ink roller or printed matter. In addition, Japanese Patent Application Laid-Open
When the lipophilic heat-sensitive layer is provided on the hydrophilic swelling layer as described in Japanese Patent No. 287062, heat absorption by the aluminum substrate is suppressed, but the hydrophilic swelling layer is swollen by dampening water. If the ink is applied in a state where the ink is not supplied, the payment of the ink becomes worse, and the waste paper increases.

[0011]

As described above, a heat-sensitive material having good on-press developability, high sensitivity, and high printing durability has not yet been obtained. Therefore, the present invention, in a lithographic printing plate precursor that can be developed on a printing press to form an image by heat, shows good on-press developability including aging,
And it aims at obtaining more printed matter.

[0012]

According to the present invention, there is provided a heat-sensitive layer containing a fine particle polymer which is not united by heat used for image formation on a hydrophilic support.
By having a functional group capable of reacting with a functional group present in another particulate polymer or a functional group present in another component in the heat-sensitive layer, on-press developability including aging is good. The present invention provides a heat-sensitive lithographic printing plate precursor which can be developed on a printing press and has high printing durability.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [Particulate polymer that is not united by heat used for image formation]
The particulate polymer which is contained in the heat-sensitive layer of the lithographic printing plate precursor according to the present invention and is not united by heat used for image formation (hereinafter, referred to as
The fine particle polymer is also not particularly limited as long as it has a functional group present in another fine particle polymer or a functional group capable of reacting with a functional group present in another component in the thermosensitive layer. And latexes containing these functional groups. The average particle size of these particles is preferably from 0.01 μm to 20 μm, more preferably from 0.05 μm to 2.0 μm, and most preferably from 0.10 μm to 1.0 μm. If the average particle size is too large, the resolution will be poor, and if it is too small, the stability over time will be poor.

These fine-particle polymers may react with each other via a functional group. When the heat-sensitive layer contains a hydrophilic resin or a low-molecular compound as described below as another additive, May react with them. Further, two or more kinds of fine particle polymers may be provided with different functional groups which react thermally with each other to cause the fine particle polymers to react with each other.
These functional groups include a polymerization reaction with an unsaturated group, an addition reaction with an isocyanate group or a block thereof and a compound having an active hydrogen atom (eg, amine, alcohol, carboxylic acid, etc.), an epoxy group and an amino group / carboxyl group.・ Addition reaction with hydroxyl group, condensation reaction between carboxyl group and hydroxyl group or amino group,
A ring-opening addition reaction between an acid anhydride and an amino group or a hydroxyl group may be mentioned, but any reaction may be used as long as a chemical bond is formed.

As described above, the finely divided polymer having a reactive functional group includes an acrylate group, a methacrylate group,
Preferred are those having a vinyl group, an allyl group, an epoxy group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate, an acid anhydride and a group protecting them. These may be introduced at the time of polymerization, or may be introduced after polymerization by utilizing a polymer reaction.

When introduced during the polymerization, it is preferable to carry out emulsion polymerization or suspension polymerization of the monomer having these functional groups. Specifically, allyl methacrylate, allyl acrylate, vinyl methacrylate, vinyl acrylate, glycidyl methacrylate, glycidyl acrylate, 2-isocyanate ethyl methacrylate or a block isocyanate obtained by blocking the same with an alcohol or the like, 2-isocyanate ethyl acrylate or an alcohol thereof, etc. Block isocyanate, 2-aminoethyl methacrylate, 2-aminoethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylic acid,
Examples include, but are not limited to, homopolymers or copolymers of monomers such as methacrylic acid, maleic anhydride, diacrylate, dimethacrylate, and the like. The copolymerizable monomer is not limited as long as it does not have a functional group related to the reaction, such as styrene, alkyl acrylate, alkyl methacrylate, acrylonitrile, and vinyl acetate. It is preferred to introduce a functional monomer. Specific examples of these polyfunctional monomers include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate,
3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate Acrylate, 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetra Acrylate, Ruby penta acrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

Examples of the methacrylate include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloxy-2-hi Rokishipuropokishi) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
There are 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like.

The crotonates include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like.

Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240 and JP-A-59-5240. 59-524
1, those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.

Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide, and the like.

Examples of other preferred amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

A urethane-based addition-polymerizable compound produced by an addition reaction between an isocyanate and a hydroxyl group is also suitable.
JP-A-8-41708 discloses a polyisocyanate compound having two or more isocyanate groups in one molecule, wherein a hydroxyl-containing vinyl monomer represented by the following formula (A) is added to one molecule. And vinyl urethane compounds containing at least two polymerizable vinyl groups.

General formula (A) CH ₂ ＣC (R ₄₁ ) COOCH ₂ CH (R ₄₂ ) OH (where R ₄₁ and R ₄₂ represent H or CH ₃ )

Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and
No. 49860, No. 56-17654, No. 62
Urethane compounds having an ethylene oxide skeleton described in JP-B-39417 and JP-B-62-39418 are also suitable.

Further, radical polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909, and JP-A-1-105238 can be used. good.

As another example, see JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
No. 490, polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in each publication. Also,
JP-B-46-43946, JP-B-1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
Vinyl phosphonic acid compounds described in JP-A-2-25493 can also be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Japan Adhesion Association Journal vol. 20, No. 7, pages 300-308 (198
(4 years) as photocurable monomers and oligomers can also be used.

These functional groups may be introduced into the polymer by utilizing a polymer reaction. For example, there can be mentioned a polymer reaction as described in WO96-34316. The fine particle polymer containing a functional group chemically bonded to each other by the heat preferably has a hydrophilic surface and is dispersed in water. In order to make the surface of the particulate polymer hydrophilic as described above, a hydrophilic polymer or oligomer such as polyvinyl alcohol or polyethylene glycol, or a hydrophilic low-molecular compound may be adsorbed on the surface of the particulate, but the method is not limited thereto. It is not something to be done. It is preferable to add 50% by weight or more, more preferably 60% or more, of the particulate polymer having a functional group chemically bonded to each other by heat.

[Light-to-heat conversion material] The lithographic printing plate precursor of the present invention can be used for image writing by laser light irradiation or the like by including a light-to-heat conversion material in the heat-sensitive layer or in a layer adjacent thereto. it can. The light-to-heat conversion material is not particularly limited as long as it absorbs the wavelength of the light source, such as carbon black / metal fine particles and dye, but a compound that absorbs infrared rays and converts it into heat is particularly preferable.

The photothermal conversion material is particularly preferably a substance that absorbs light of 700 nm or more, and various pigments and dyes can be used. Examples of pigments 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), "Printing ink technology" C
MC Publishing, 1984) can be used.

Examples of the types of pigments include black pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and polymer-bound dyes. 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 And quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like.

These pigments may be used without being subjected to a surface treatment, or may be used after being subjected to a surface treatment. The method of surface treatment is a method of surface coating a hydrophilic resin or lipophilic resin,
A method of attaching a surfactant, a method of bonding a reactive substance (for example, silica sol, alumina sol, a silane coupling agent, an epoxy compound, an isocyanate compound, and the like) to the surface of the pigment are considered. The above surface treatment method,
It is described in "Properties and Applications of Metallic Soaps" (Koshobo), "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986). Among these pigments, those that absorb infrared light or near-infrared light are particularly preferable because they are suitable for use in lasers that emit infrared light or near-infrared light.

As such a pigment absorbing infrared light or near infrared light, carbon black, carbon black coated with a hydrophilic resin, and carbon black modified with silica sol are preferably used. Among these, carbon black whose surface is coated with a hydrophilic resin or silica sol is useful as a material that is easily dispersed in a water-soluble resin and does not impair hydrophilicity.

The particle size of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. As the disperser, an ultrasonic disperser,
Sand mills, attritors, pearl mills, super mills, ball mills, impellers, dispersers, KD mills, colloid mills, dynatrons, three-roll mills, pressure kneaders and the like can be mentioned. Details are described in "Latest Pigment Application Technology" (CMC Publishing, 1986).

As the dye, 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. Specific examples include azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, and cyanine dyes. Among these dyes, those that absorb infrared light or near-infrared light are particularly preferable because they are suitable for use in lasers that emit infrared light or near-infrared light.

Dyes which absorb infrared light or near infrared light include, for example, JP-A-58-125246 and JP-A-59-125246.
No. 84356, JP-A-60-78787, U.S. Pat. No. 4,973,572, JP-A-10-26851.
2, cyanine dyes described in
Methine dyes described in JP-A-173696, JP-A-58-181690 and JP-A-58-194595; JP-A-58-112793; JP-A-58-224.
No. 793, JP-A-59-48187, JP-A-59-7
3996, JP-A-60-52940, JP-A-60-52
No. 63744, etc., naphthoquinone dyes described in JP-A-58-112792, etc., cyanine dyes described in British Patent 434,875, and U.S. Pat. No. 4,756,993. And cyanine dyes described in U.S. Pat. No. 4,973,572 and dyes described in JP-A-10-268512.

[0039]

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[Wherein, R¹, R^Two, R^Three, R^Four, R^FiveAnd R⁶
Is a substituted or unsubstituted alkyl group; Z ¹And Z^TwoAlso replace
Or unsubstituted phenyl or naphthalene group; L is substituted
Or an unsubstituted methine group, wherein the substituent has 8 or less carbon atoms
An alkyl group, a halogen atom or an amino group,
The tin group is bonded to the substituents on the two methine carbons
Optionally formed cyclohexene formed by
Or a ring containing a cyclopentene ring
And the substituent is an alkyl group having 6 or less carbon atoms or halogen.
X is an anionic group; n is 1 or 2;¹,
R^Two, R^Three, R^Four, R^Five, R⁶, Z¹And Z^TwoAt least one of
One is an acidic group or an alkali metal base or an amine salt of an acidic group
A substituent having a group is shown.

[0041]

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[Wherein R¹¹Is a substituted or unsubstituted al
Killed, substituted or unsubstituted aryl or substituted
Or an unsubstituted heterocyclic group; R¹²And R^FifteenIs a hydrogen atom or
A group which can be substituted in place of a hydrogen atom: R¹³And R¹⁴Is hydrogen field
Atom, halogen atom, substituted or unsubstituted alkoxy group
Or a substituted or unsubstituted alkyl group, provided that R¹³And R
¹⁴Are not simultaneously hydrogen atoms: R¹⁶And R¹⁷Is a replacement
Or unsubstituted alkyl group, substituted or unsubstituted aryl
Group, acyl group or sulfonyl group, or R¹⁶And R ¹⁷In non
The formation of a 5- or 6-membered metal ring is shown. ]

Also, US Pat.
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645 (U.S. Pat. No. 4,327,169), a trimethinethiapyrylium salt described in JP-A-58-1810.
No. 51, No. 58-220143, No. 59-41363
Nos. 59-84248, 59-84249, 59-146063, and 59-146061 and pyrylium compounds described in JP-A-59-2161.
No. 46, a cyanine dye disclosed in U.S. Pat. No. 4,283,4.
No. 75, pentamethine thiopyrylium salt and the like, and pyrilium compounds disclosed in Japanese Patent Publication Nos. 5-135514 and 5-19702, Epolig manufactured by Eporin Co.
ht III-178, Epollight III-130,
Epollight III-125 and the like are particularly preferably used. Particularly preferred among these dyes are the water-soluble cyanine dyes of the above formula (I). Specific compounds are listed below.

[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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Next, the light-heat converting metal fine particles will be described. Many of the metal particles are photothermal and self-heating. Preferred metal fine particles include Si, A
1, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, Y, Zr, Mo, Ag, Au, Pt, Pd, R
Simple particles or alloys of h, In, Sn, W, Te, Pb, Ge, Re, and Sb, or fine particles of oxides and sulfides thereof. Among the metals constituting these fine metal particles, preferred metals are those which have a melting point of about 1000 ° C. or less and easily absorb in the infrared, visible or ultraviolet regions, such as Re, Sb, Te, and Au. , A
g, Cu, Ge, Pb and Sn. Particularly preferred are metal fine particles having a relatively low melting point and a relatively high absorbance to heat rays, such as Ag, Au, Cu, and the like.
Among Sb, Ge and Pb, particularly preferred elements are Ag, A
u and Cu.

Further, for example, Re, Sb, Te, Au, A
g, Cu, Ge, Pb, Sn and other low melting point metal particles and self-heating metal particles such as Ti, Cr, Fe, Co, Ni, W, Ge, etc. It may be composed of a substance. Ag, P
It is preferable to use a combination of a metal-type micro-piece and a metal-type micro-piece, which have a particularly large light absorption when used as a micro-piece such as t or Pd. The effects of the present invention are more exerted by subjecting the surfaces of the above-described metal simple substance and alloy fine particles to hydrophilic treatment. Means of surface hydrophilicity is a compound that is hydrophilic and has an adsorptivity to particles, such as a surface treatment with a surfactant, or a surface treatment with a substance having a hydrophilic group that reacts with the constituent substances of the particles, A method such as providing a protective colloid hydrophilic polymer film can be used. Particularly preferred is a surface silicate treatment. For example, in the case of iron fine particles, sodium silicate (3
%) The surface can be made sufficiently hydrophilic by immersing it in an aqueous solution for 30 seconds. Other metal fine particles can be subjected to surface silicate treatment in the same manner.

The particle size of these particles is 10 μm or less, preferably 0.003 to 5 μm, more preferably
0.01 to 3 μm. The finer the particle size, the lower the heat-sealing temperature, that is, the higher the light sensitivity in the heat mode, which is advantageous.

The effects of the present invention can be further exerted by subjecting the surfaces of the above-mentioned fine particles of a metal simple substance and an alloy to hydrophilic treatment. Means for making the surface hydrophilic include a compound that is hydrophilic and has an adsorptivity to particles, for example, a surface treatment with a surfactant, a surface treatment with a substance having a hydrophilic group that reacts with a constituent material of the particles, A method such as providing a protective colloid hydrophilic polymer film can be used.
Particularly preferred is a surface silicate treatment. For example, in the case of iron fine particles, sodium silicate (3%) at 70 ° C.
The surface can be made sufficiently hydrophilic by immersing it in an aqueous solution for 30 seconds. Other metal fine particles can be subjected to surface silicate treatment in the same manner.

In the present invention, when these infrared absorbers are used, the amount of the infrared absorber is determined based on the total solid content of the image recording layer.
It is used in an amount of at least 1% by weight, preferably at least 2% by weight, particularly preferably at least 5% by weight. If the content of the infrared absorbent is less than 1% by weight, the sensitivity is lowered.

[Hydrophilic resin] A hydrophilic resin may be added to the heat-sensitive layer of the lithographic printing plate precursor according to the invention. The addition of the hydrophilic resin not only improves the on-press developability,
The film strength of the heat-sensitive layer itself also increases. As the hydrophilic resin,
For example, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl and carboxymethyl are preferred. Specific hydrophilic resins include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and their Na salts, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids And salts thereof, polymethacrylic acids and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers and copolymers of hydroxypropyl acrylate, hydroxy Butyl methacrylate homopolymers and copolymers, hydroxybutyl acrylate homopolymers and copolymers, polyethylene Glycols, hydroxypropylene polymers, polyvinyl alcohols and homopolymers and copolymers of hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide having a degree of hydrolysis of at least 60% by weight, preferably at least 80% by weight; Examples include homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide, and homopolymers and copolymers of 2-acrylamido-2-methylpropanesulfonic acid and salts thereof.

The amount of the hydrophilic resin added to the heat-sensitive layer was 2%
-40% is preferable, and 3% -30% is more preferable.
If it is less than 2%, the film strength is low, and if it is more than 40%, on-press developability is improved, but printing durability is deteriorated.

[Compound that Initiates or Promotes the Reaction] The fine particle polymer having a reactive group described above is used in the heat-sensitive layer of the lithographic printing plate precursor according to the present invention. A compound which promotes the reaction may be added. Examples thereof include compounds that generate radicals or cations by heat.Onium salts containing lophine dimer, trihalomethyl compound, peroxide, azo compound, diazonium salt or diphenyliodonium salt, acylphosphine, imidosulfo Nart and the like. These compounds can be added in the range of 1% by weight to 20% by weight in the heat-sensitive layer. Preferably it is in the range of 3% by weight to 10% by weight. If it is more than this, the on-press developability will be poor, and if it is less than this, the effect of initiating or accelerating the reaction will be weakened and the printing durability will deteriorate.

[Low-Molecular Compound Reacting with Fine Particle Polymer That Does Not Combine by Heat Used for Image Formation] The heat-sensitive layer of the lithographic printing plate precursor according to the present invention further reacts with the reactive group in the fine particle polymer. And a low molecular weight compound having a functional group and a protecting group thereof.
The addition amount of these compounds is preferably 5% by weight to 40% by weight in the heat-sensitive layer, and particularly preferably 5% by weight to 20% by weight. If the amount is less than this, the cross-linking effect is small and the printing durability becomes insufficient. The compounds that can be used for these are described below.

Examples of the low-molecular compound include compounds having an unsaturated group. The compound having an unsaturated group is a radical polymerizable compound having at least one ethylenically unsaturated double bond, and has a terminal ethylenic compound. The compound is selected from compounds having at least one, preferably two or more unsaturated bonds. Such compounds are widely known in the industrial field, and they can be used in the invention without any particular limitation. These have chemical forms such as, for example, monomers, prepolymers, ie, dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of the monomer and its copolymer include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and esters and amides thereof, and are preferred. As the ester, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used.
Further, an unsaturated carboxylic acid ester having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group, an addition reaction product of an amide with a monofunctional or polyfunctional isocyanate, an epoxy, a monofunctional or A dehydration-condensation reaction product with a functional carboxylic acid is also preferably used. Also,
An addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, further, a halogen group or Substitution products of unsaturated carboxylic esters or amides having a leaving substituent such as a tosyloxy group with monofunctional or polyfunctional alcohols, amines and thiols are also suitable. As another example, it is also possible to use a group of compounds in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene or the like.

Specific examples of the radical polymerizable compound which is an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylates such as ethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3-butane. Diol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, , 4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, penta Risuri toll triacrylate,
Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate,
Examples include sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, and polyester acrylate oligomer.

Examples of the methacrylate include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloxy-2-hi Rokishipuropokishi) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
There are 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like.

The crotonates include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like.

Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include, for example, JP-B-46-27926, JP-B-51-47334,
Aliphatic alcohol esters described in JP-A-57-196231, JP-A-59-5240 and JP-A-59-196231
No. 5,241, those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also suitably used.

Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylenebis-acrylamide, methylenebis-methacrylamide, 1,6-hexamethylenebis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide, and the like.

Examples of other preferred amide-based monomers include those having a cyclohexylene structure described in JP-B-54-21726. Urethane-based addition-polymerizable compounds produced by an addition reaction between an isocyanate and a hydroxyl group are also suitable. Specific examples of such compounds include, for example, one molecule described in JP-B-48-41708. A urethane compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a hydroxyl group-containing vinyl monomer represented by the following formula (A) to a polyisocyanate compound having two or more isocyanate groups: And the like.

Formula (A) CH ₂ ＣC (R ⁴¹ ) COOCH ₂ CH (R ⁴² ) OH (where R ⁴¹ and R ⁴² represent H or CH ₃ )

Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, and
No. 49860, No. 56-17654, No. 62
Urethane compounds having an ethylene oxide skeleton described in JP-A-39417 and JP-B-62-39418 are also suitable. Further, radical polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909, and JP-A-1-105238 may be used.

As another example, see JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
Examples thereof include polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in JP-A-490-490. Also,
JP-B-46-43946, JP-B-1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
Vinyl phosphonic acid compounds described in JP-A-2-25493 can also be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Further, the Journal of the Adhesion Society of Japan vol. 20, no. 7, pages 300 to 308 (1984) as photocurable monomers and oligomers can also be used.

The epoxy compound is preferably glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene diglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, bisphenols or polyphenols or hydrogenated solerano. Glycidyl ethers and the like can be mentioned. As the compound having an isocyanate, preferably, tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, cyclohexane phenylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, cyclohexyl diisocyanate, or alcohol or amines thereof And the compounds blocked with.

The amine compound preferably includes ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, propylenediamine, polyethyleneimine and the like. Preferred examples of the compound having a hydroxyl group include compounds having a terminal methylol, polyhydric alcohols such as pentaerythritol, and bisphenols / polyphenols. Preferred examples of the compound having a carboxyl group include aromatic polycarboxylic acids such as pyromellitic acid, trimellitic acid, and phthalic acid, and aliphatic polycarboxylic acids such as adipic acid. Preferred acid anhydrides include pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and the like.

[Other Additives] In the present invention, if necessary, various compounds other than these may be added. 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 B
OS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5
2015) and the dyes described in JP-A-62-293247. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can be suitably used.

It is preferable to add these coloring agents since the image area and the non-image area can be easily distinguished after image formation. The addition amount is based on the total solid content of the heat-sensitive layer coating solution.
The ratio is 0.01 to 10% by weight.

Further, in the present invention, a small amount of thermal polymerization inhibitor is used to prevent unnecessary thermal polymerization of a compound having a radically polymerizable ethylenically unsaturated double bond during preparation or storage of the heat-sensitive layer coating solution. It is desirable to add an agent. Hydroquinone, as a suitable thermal polymerization inhibitor,
p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4 -Methyl-6-t-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% to about 5% by weight based on the weight of the whole composition. Further, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition by oxygen, and may be unevenly distributed on the surface of the heat-sensitive layer in a drying process after coating. . The amount of the higher fatty acid derivative to be added is about 0.1% of the total composition.
1% to about 10% by weight is preferred.

The coating solution for the heat-sensitive layer in the present invention may contain a nonionic solvent such as described in JP-A-62-251740 and JP-A-3-208514 in order to increase the stability of processing under development conditions. Surfactant, JP-A-59
An amphoteric surfactant as described in JP-A-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, polyoxyethylene nonyl phenyl ether, and the like.

Specific examples of the amphoteric surfactant include alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, and N-tetradecyl-N , N-betaine type (for example,
(Trade name: Amogen K, manufactured by Dai-ichi Kogyo Co., Ltd.). The proportion of the nonionic surfactant and the amphoteric surfactant in the coating solution for the heat-sensitive layer is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

Further, a plasticizer may be added to the heat-sensitive layer coating solution according to the present invention, if necessary, in order to impart flexibility to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, and the like are used.

In order to produce the lithographic printing plate precursor according to the invention, the above-mentioned components necessary for the coating solution for the heat-sensitive layer are usually dissolved in a solvent and coated on a suitable support. As the solvent used herein, 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, dimethoxy Ethane, methyl lactate, ethyl lactate,
N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyllactone, toluene, water and the like, but are not limited thereto. Absent. 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 feeling on the support obtained after coating and drying
The coating amount (solid content) of the thermal layer varies depending on the application.
Generally speaking, 0.5 to 5.0 g of the printing plate precursor
/ M ^TwoIs preferred. Various methods for applying
Can be used, for example, a bar coater coating,
Spin coating, spray coating, curtain coating, dip coating
Cloth, air knife coating, blade coating, roll coating etc.
Can be mentioned. As the application amount decreases,
Sensitivity is high, but the function of image recording is high
The film properties of the layer are reduced.

In the heat-sensitive layer coating solution according to the present invention, a surfactant for improving coating properties, for example, JP-A-62-17
No. 0950 can be added. The preferred addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the solid content of the material of the entire thermosensitive layer.

[Overcoat Layer] In the lithographic printing plate precursor according to the invention, a water-soluble overcoat layer can be provided on the heat-sensitive layer in order to prevent the surface of the heat-sensitive layer from being stained by a lipophilic substance. The water-soluble overcoat layer used in the present invention can be easily removed at the time of printing and contains a resin selected from water-soluble organic polymer compounds. As the water-soluble organic polymer compound used herein, a film formed by coating and drying has a film-forming ability, specifically, polyvinyl acetate (having a hydrolysis rate of 65% or more) and polyacrylic. Acid and its alkali metal salt or amine salt, polyacrylic acid copolymer and its alkali metal salt or amine salt, polymethacrylic acid and its alkali metal salt or amine salt, polymethacrylic acid copolymer and its alkali metal salt or amine Salt, polyacrylamide and its copolymer, polyhydroxyethyl acrylate, polyvinylpyrrolidone and its copolymer, polyvinyl methyl ether, polyvinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamide-2-methyl-1-methyl Propanesulfonic acid and its alkali Genus salt or amine salt, poly-2-acrylamido-2-methyl-1-propanesulfonic acid copolymer and its alkali metal salt or amine salt, gum arabic, cellulose derivative (for example, carboxymethyl cellulose, carboxyethyl cellulose, Methylcellulose, etc.) and modified products thereof, white dextrin, pullulan, enzymatically decomposed etherified dextrin and the like. Further, according to the purpose, two or more of these resins can be used in combination.

The above-mentioned water-soluble photothermal conversion agent may be added to the overcoat layer. Furthermore, in the case of aqueous solution application, a nonionic surfactant such as polyoxyethylene nonylphenyl ether and polyoxyethylene dodecyl ether can be added to the overcoat layer in order to ensure uniformity of application. . Dry coating amount of the overcoat layer, 0.1 to 2.0 g / m ² is preferred. If the amount is less than this, fingerprint adhesion stains occur, and if it is more than that, on-press developability deteriorates.

[Support] In the lithographic printing plate precursor of the present invention, the hydrophilic support to which the heat-sensitive layer can be applied is a dimensionally stable plate-like material such as paper or plastic (for example, Paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate)
Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic film on which the above-mentioned metal is laminated or vapor-deposited. Preferred supports include a polyester film or an aluminum plate.

As the support used in the lithographic printing plate precursor according to the invention, it is preferable to use an aluminum plate which is lightweight and has excellent surface treatment properties, workability and corrosion resistance. Aluminum materials used for this purpose include JIS 105
0 material, JIS 1100 material, JIS 1070 material, Al
-Mg-based alloy, Al-Mn-based alloy, Al-Mn-Mg-based alloy, Al-Zr-based alloy, Al-Mg-Si-based alloy and the like.

The known techniques relating to aluminum materials that can be used for the support are listed below. (1) For JIS 1050 material, the following technology is disclosed. JP-A-59-153861, JP-A-61-5139
5, JP-A-62-146694, JP-A-60-2157
25, JP-A-60-215726, JP-A-60-215
727, JP-A-60-215728, JP-A-61-27
2357, JP-A-58-11759, JP-A-58-42
493, JP-A-58-221254, JP-A-62-14
8295, JP-A-4-254545, JP-A-4-165
041, Japanese Patent Publication No. 3-68939, Japanese Patent Application Laid-Open No. 3-23459.
4, JP-B 1-47545, JP-A-62-140894
No. Gazette. In addition, Tokiko 1-35910, Tokiko Showa 55
-28874 is also known.

(2) With respect to JIS 1070 material, the following technology is disclosed. JP-A-7-81264, JP-A-7-305133, JP-A-8-49034, JP-A-8-73974, JP-A-8-
108659 and JP-A-8-92679.

(3) With respect to Al-Mg based alloys, the following techniques are disclosed. JP-B-62-5080, JP-B-63-60823, JP-B-3-61753, JP-A-60-203496, JP-A-60-203497, JP-B-3-11635, JP-A-6-11
1-227493, JP-A-62-2794, JP-A-6-23794
3-47347, JP-A-63-47348, JP-A-63-63
-47349, JP-A-64-61293, JP-A-63-63
135294, JP-A-63-87288, 4-7
3392, JP-B-7-100844, JP-A-62-14
9856, JP-B-4-73394, JP-A-62-181
191, JP-B-5-76530, JP-A-63-3029
4, No. 6-37116. Also, Japanese Patent Application Laid-Open No. 2-2
15599 and JP-A-61-201747 are also known.

(4) With respect to Al-Mn alloys, the following techniques are disclosed. JP-A-60-230951, JP-A-1-306288,
JP-A-2-293189. In addition, Japanese Patent Publication No. 54-4
2284, Japanese Patent Publication 4-19290, Japanese Patent Publication 4-1-929
1, Japanese Patent Publication No. 4-19292, JP-A-61-35995,
JP-A-64-51992, US5009722, US5
No. 028276 and JP-A-4-226394 are also known. (5) With respect to Al-Mn-Mg based alloys, the following technology is disclosed. JP-A-62-86143, JP-A-3-222796, JP-B-63-60824, JP-A-60-63346, JP-A-60-63347, EP223737, JP-A1-2
83350, US4818300, BR1222777
Etc. are known.

(6) The following techniques are known for Al-Zr alloys. JP-B-63-15978, JP-A-61-51395, JP-A-63-143234, JP-A-63-143235 and the like are known. (7) For the Al-Mg-Si alloy, BR142
1710 and the like are known.

The following contents can be used as a method for producing an aluminum plate for a support. The aluminum alloy melt having the above-mentioned content components and alloy component ratios is subjected to a cleaning treatment and cast according to a conventional method. For the cleaning process,
In order to remove unnecessary gases such as hydrogen in the molten metal, flux treatment, degassing treatment using Ar gas, Cl gas, etc., so-called rigid media filters such as ceramic tube filters and ceramic foam filters,
Filtering using a filter material such as alumina flakes or alumina balls, filtering using a glass cloth filter or the like, or processing combining degassing and filtering is performed. These cleaning processes are performed in the molten metal.
It is desirable that the method be implemented in order to prevent defects due to foreign matter such as nonmetallic inclusions and oxides and defects due to gas dissolved in the molten metal.

Regarding the filtering of the molten metal, Japanese Patent Laid-Open Nos. 6-57342, 3-162530, 5-
140659, JP-A-4-231425, JP-A-4-2
76031, JP-A-5-311261, JP-A-6-13
6466 and the like are known. Regarding degassing of molten metal,
JP-A-5-51659, JP-A-5-51660, JP-A-5-49148, and JP-A-7-40017 are known. As described above, casting is performed using the molten metal subjected to the cleaning treatment. Regarding the casting method, there are a method using a fixed mold typified by a DC casting method and a method using a driving mold typified by a continuous casting method. When the DC casting method is used, the solidification is performed at a cooling rate of 1 to 300 ° C./sec. When the temperature is less than 1 ° C./sec, a large number of coarse intermetallic compounds are formed.

The continuous casting method includes a method using a cooling roll, represented by the Hunter method and the 3C method, a Hadley method, a method using a cooling belt represented by the Al Swiss Caster II type, and a method using a cooling block. It is being done. The cooling rate when using the continuous casting method is 100 to 1000 ° C. /
Coagulated in seconds. Generally, since the cooling rate is higher than that of the DC casting method, there is a feature that the solid solubility of the alloy component in the aluminum matrix can be increased. Regarding the continuous casting method, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 3-7 / 1990.
9798, JP-A-5-201166, JP-A-5-156
414, JP-A-6-262203, JP-A-6-1229
49, JP-A-6-210406, JP-A-6-26230
8 etc. are disclosed.

When DC casting is performed, the thickness is 300 to 80.
A 0 mm ingot can be manufactured. The ingot, according to the usual method,
Facing is performed and the surface layer is 1 to 30 mm, preferably 1 to 30 mm.
10 mm is cut. Thereafter, a soaking process is performed as necessary. In the case of performing the soaking treatment, 1 to 450 ° C. to 620 ° C. is used to prevent the intermetallic compound from becoming coarse.
The heat treatment is performed for at least 48 hours. When the time is shorter than 1 hour, the effect of the soaking treatment becomes insufficient. Next, hot rolling and cold rolling are performed to obtain a rolled aluminum plate. The starting temperature of hot rolling is 350 to 500
It is in the range of ° C. Intermediate annealing treatment may be performed before, after, or during the cold rolling. The intermediate annealing conditions in this case are set to 280 ° C. to 6 ° C. using a batch annealing furnace.
00 ° C for 2 to 20 hours, desirably 350 to 500 ° C
Heating for 2 to 10 hours or using a continuous annealing furnace for 4 hours.
360 seconds or less at 00 to 600 ° C., desirably 450 to
Heat treatment at 550 ° C. for 120 seconds or less can be employed. Heating at a rate of 10 ° C./sec or higher using a continuous annealing furnace can also make the crystal structure fine.

By the above steps, a predetermined thickness of 0.1 to 0.1
The flatness of the Al plate finished to 0.5 mm may be improved by a straightening device such as a roller leveler or a tension leveler in order to improve the flatness. The flatness may be improved after the plate is cut into a sheet, but it is desirable to improve the flatness in a continuous coil state in order to improve productivity. Further, in order to process the board width to a predetermined width, a slitter line is usually passed. The end face of the plate cut by the slitter has one or both of a shear surface and a fracture surface when cut by a slitter blade.

The accuracy of the thickness of the plate is preferably within ± 10 μm, preferably within ± 6 μm over the entire length of the coil.
The thickness difference in the width direction is within 6 μm, preferably 3 μm.
Within is good. Also, the accuracy of the board width is within ± 1.0mm,
Preferably, it is within ± 0.5 mm. The surface roughness of the Al plate is easily affected by the surface roughness of the rolling roll,
Finally, the center line surface roughness (Ra) is Ra = 0.1 to
It is preferable to finish to about 1.0 μm. If Ra is too large, the original roughness of Al, that is, the rough rolling streaks transferred by the rolling rolls can be seen from above the heat-sensitive layer when the surface-roughening treatment for a lithographic printing plate and the heat-sensitive layer are applied. Is not preferable in appearance. Roughness of Ra = 0.1 μm or less is industrially undesirable because the surface of the rolling roll needs to be finished to an excessively low roughness.

Further, a thin oil film may be formed on the surface of the Al plate in order to prevent scratches due to friction between the Al plates. Oil slicks may be volatile,
A non-volatile one is appropriately used. If there is too much oil,
A slip failure occurs in the production line, but if there is no oil amount, a defect occurs during transportation of the coil. Therefore, the oil amount is 3 mg / m ² or more and 100 mg / m ² or less, and a desirable upper limit is 50 mg / m ^2. m ² or less, more preferably 10
mg / m ² or less is good. Regarding cold rolling,
No. -210308 is disclosed.

When continuous casting is performed, for example, using a cooling roll such as a Hunter method, a cast plate having a thickness of 1 to 10 mm can be directly continuously cast and rolled, and there is an advantage that the step of hot rolling can be omitted. In addition, when a cooling roll such as the Hasley method is used, a cast plate having a plate thickness of 10 to 50 mm can be cast,
In general, a hot-rolled roll is arranged immediately after casting and continuously rolled to obtain a continuously cast rolled plate having a thickness of 1 to 10 mm. These continuous cast rolled sheets are finished to a thickness of 0.1 to 0.5 mm through the steps of cold rolling, intermediate annealing, improvement of flatness, slits, etc., as described in the case of DC casting. Can be Regarding the intermediate annealing condition and the cold rolling condition when the continuous casting method is used, refer to JP-A-6-2205.
93, JP-A-6-210308, JP-A-7-5541
1, JP-A-8-92709 and the like are disclosed.

The surface of the Al plate produced by the above method is subjected to a surface treatment such as a surface roughening treatment, and a heat-sensitive layer is applied thereon to obtain a lithographic printing plate precursor. In the surface roughening treatment, mechanical surface roughening, chemical surface roughening, and electrochemical surface roughening are performed alone or in combination. Further, it is also preferable to perform an anodic oxidation treatment for securing the surface with difficulty in scratching or a treatment for increasing the hydrophilicity.

Hereinafter, the surface treatment of the support will be described. Prior to roughening the aluminum plate, if necessary, for example, a surfactant to remove rolling oil on the surface,
A degreasing treatment with an organic solvent or an alkaline aqueous solution may be performed. In the case of alkali, treatment such as neutralization and removal of smut may be performed with an acidic solution.

Next, in order to improve the adhesion between the support and the heat-sensitive layer and to impart water retention to the non-image area, the surface of the support is roughened, so-called graining treatment. Specific means of the graining method include sand blast, ball grain, wire grain, brush grain using a nylon brush and an abrasive / water slurry,
There is a mechanical graining method using a honing grain or the like in which an abrasive / water slurry is sprayed onto the surface at a high pressure, and a chemical graining method in which the surface is roughened with an etching agent composed of an alkali, an acid, or a mixture thereof. . In addition, British Patent No. 896,563,
JP-A-3-67507, JP-A-54-146234 and JP-B-48-28123 describe the method of electrochemical graining, or JP-A-53-1232.
No. 04, JP-A-54-63902 and a combination of the mechanical graining method and the electrochemical graining method described in JP-A-56-55261. A method is also known in which a graining method is combined with a chemical graining method using a saturated aqueous solution of an aluminum salt of a mineral acid. Also, a method of bonding the granular material to the support material with an adhesive or a method having the effect thereof to roughen the surface, or a continuous band or roll having fine unevenness is pressed against the support material to remove the unevenness. A rough surface may be formed by transferring.

A plurality of such surface roughening methods may be performed in combination, and the order, number of repetitions, and the like can be arbitrarily selected. When a plurality of surface roughening treatments are combined, a chemical treatment with an acid or alkali aqueous solution can be performed during that time to make the subsequent surface roughening treatment uniform. Specific examples of the above-mentioned acid or alkali aqueous solution include, for example, acids such as hydrofluoric acid, fluorinated zirconic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and nitric acid, and alkali aqueous solutions such as sodium hydroxide, sodium silicate, and sodium carbonate. . These acid or alkali aqueous solutions can be used alone or in combination of two or more. The chemical treatment uses a 0.05 to 40% by weight aqueous solution of these acids or alkalis,
In general, the treatment is performed at a liquid temperature of 00 ° C. for 5 to 300 seconds.

Since smut is formed on the surface of the support obtained by the above-mentioned surface roughening treatment, ie, graining treatment, a treatment such as washing with water or alkali etching is appropriately performed to remove the smut. Is generally preferred. Examples of such processing include, for example,
Examples thereof include a treatment method such as an alkali etching method described in JP-A-8-28123 and a desmutting sulfate method described in JP-A-53-12739. In the case of the aluminum support used in the present invention, after performing the pretreatment as described above, usually, in order to improve abrasion resistance, chemical resistance, and water retention, an oxide film is formed on the support by anodic oxidation. Is formed.

As the electrolyte used for the anodic oxidation treatment of the aluminum plate, any electrolyte can be used as long as it forms a porous oxide film.
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. Since the treatment conditions of anodization vary depending on the electrolyte used, it cannot be specified unconditionally, but generally, the concentration of the electrolyte is a 1 to 80% solution, the liquid temperature is 5 to 70 ° C.,
It is appropriate that the current density is 5 to 60 A / dm ² , the voltage is 1 to 100 V, and the electrolysis time is 10 seconds to 5 minutes. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image area of the lithographic printing plate is easily damaged, and the ink adheres to the damaged area during printing. "Scratch dirt" is likely to occur.

The anodic oxidation treatment is performed on the surface of the lithographic printing plate support used for printing, and the back surface of the electric flux lines may cause the anode to have a thickness of 0.01 to 3 g / m ² . Generally, an oxide film is formed. Further, an anodic oxidation treatment in an alkaline aqueous solution (for example, a caustic soda aqueous solution of several%) or a molten salt, or an anodic oxidation treatment for forming a non-porous anodic oxide film using, for example, an ammonium borate aqueous solution can be performed. . Before performing anodizing treatment,
A hydrated oxide film described in JP-A-148991 or JP-A-4-97896 may be formed. An acid salt solution, a hydrated oxide film forming treatment, a chemical conversion film forming treatment described in JP-A-56-144195, and the like can also be performed.

The aluminum support used in the lithographic printing plate precursor according to the present invention can be treated with an organic acid or a salt thereof after anodizing treatment, or the organic acid or a salt thereof can be used as an undercoat layer applied to a heat-sensitive layer. . Examples of the organic acid or a salt thereof include an organic carboxylic acid, an organic phosphonic acid, an organic sulfonic acid or a salt thereof, and preferably an organic carboxylic acid or a salt thereof. Examples of the organic carboxylic acids include aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, lauric acid, palmitic acid and stearic acid; unsaturated aliphatic monocarboxylic acids such as oleic acid and linoleic acid; oxalic acid, succinic acid Aliphatic dicarboxylic acids such as acid, adipic acid, and maleic acid; oxycarboxylic acids such as lactic acid, gluconic acid, malic acid, tartaric acid, and citric acid; aromatic carboxylic acids such as benzoic acid, mandelic acid, salicylic acid, and phthalic acid; , IIb, IIIb, IVa, VI
Group b and VIII metal salts and ammonium salts. Preferred among the organic carboxylate salts are formic acid,
Acetic acid, butyric acid, propionic acid, lauric acid, oleic acid,
The above-mentioned metal salts and ammonium salts of succinic acid and benzoic acid. These compounds may be used alone or in combination of two or more.

These compounds are used in water and alcohol in 0.0
It is preferably dissolved in a concentration of from 0.01 to 10% by weight, particularly from 0.01 to 1.0% by weight. The processing conditions include a temperature range of 25 to 95 ° C, preferably 50 to 95 ° C.
H is 1 to 13, preferably 2 to 10, 10 seconds to 20 minutes,
Preferably, the support is immersed for 10 seconds to 3 minutes, or the treatment liquid is applied to the support.

Further, after the anodic oxidation treatment, treatment with the following compound solution or these compounds can be used as an undercoat layer applied to the heat-sensitive layer. Suitable compounds include, for example, optionally substituted phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, organic phosphonic acids such as methylenediphosphonic acid and ethylenediphosphonic acid, substituted Phenyl phosphate, naphthyl phosphate, which may have a group,
Organic phosphoric acids such as alkyl phosphoric acid and glycerophosphoric acid, organic phosphinic acids such as optionally substituted phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid, glycine, β
-Amino acids such as alanine, valine, serine, threonine, aspartic acid, glutamic acid, arginine, lysine, tryptophan, parahydroxyphenylglycine, dihydroxyethylglycine, and anthranilic acid; aminosulfonic acids such as sulfamic acid and cyclohexylsulfamic acid; 1-amino acid Methylphosphonic acid, 1-dimethylaminoethylphosphonic acid, 2-aminoethylphosphonic acid, 2-aminopropylphosphonic acid, 4-aminophenylphosphonic acid, 1-aminoethane-1,1-diphosphonic acid, 1-amino-1-phenyl Aminophosphonic acids such as methane-1,1-diphosphonic acid, 1-dimethylaminoethane-1,1-diphosphonic acid, 1-dimethylaminobutane-1,1-diphosphonic acid, and ethylenediaminetetramethylenephosphonic acid; Compounds, and the like.

Also, hydrochloric acid, sulfuric acid, nitric acid, sulfonic acid (such as methanesulfonic acid) or oxalic acid, and an alkali metal,
Salts with ammonia, lower alkanolamines (such as triethanolamine), lower alkylamines (such as triethylamine) and the like can also be suitably used.

Polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polyethyleneimine and its mineral salts, poly (meth) acrylic acid and its metal salts, polystyrenesulfonic acid and its metal salts, alkyl (meth) acrylate and 2-acrylamide Water-soluble polymers such as 2-methyl-1-propanesulfonic acid and its metal salts, polymers of trialkylammonium methylstyrene and its copolymers with (meth) acrylic acid, and polyvinylphosphonic acid can also be used preferably. it can. Further, soluble starch, carboxymethylcellulose, dextrin, hydroxyethylcellulose, gum arabic, guar gum, sodium alginate, gelatin, glucose, sorbitol and the like can also be suitably used. These compounds may be used alone or in combination of two or more.

In the case of treatment, these compounds are preferably dissolved in water and / or methyl alcohol to a concentration of 0.001 to 10% by weight, particularly 0.01 to 1.0% by weight. The temperature is in the range of 25 to 95 ° C., preferably 50 to 95 ° C., and the pH is 1 to 13, preferably 2 to 10, 10 seconds to 20 minutes, and preferably 10 seconds to 3 minutes.

When used as an undercoat layer applied to a heat-sensitive layer, similarly, water and / or methyl alcohol may be used in an undercoat layer.
It is dissolved so as to have a concentration of 1 to 10% by weight, particularly 0.01 to 1.0% by weight, and if necessary, a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, hydrochloric acid, phosphoric acid or the like. Adjust the pH with an acidic substance,
It can also be used in the range of ~ 12. Further, a yellow dye can be added for improving the tone reproducibility of the lithographic printing plate precursor. The coating amount of the organic undercoat layer after drying is 2 to
200 mg / m ² is suitable, preferably 5 to 100 mg / m ^2.
mg / m ² . If the above-mentioned coating amount is less than 2 mg / m ² , a sufficient effect for the original purpose such as prevention of stain cannot be obtained. On the other hand, if it exceeds 200 mg / m ² , the printing durability will decrease.

An intermediate layer for improving the adhesion between the support and the heat-sensitive layer may be provided. To improve adhesion,
Generally, the intermediate layer is made of a diazo resin or a phosphoric acid compound adsorbed on aluminum, for example. The thickness of the intermediate layer is arbitrary and must be such a thickness that a uniform bond-forming reaction with the upper thermosensitive layer can be performed when exposed. Normal,
The dry solid has a good coating ratio of about 1 to 100 mg / m ² ,
5-40 mg / m ² are particularly good. The usage ratio of the diazo resin in the intermediate layer is 30 to 100%, preferably 60 to 100%.

Before the above treatment and the application of the undercoat layer, the anodized support is washed with water, and then the dissolution of the anodized film in a developing solution or dampening solution is suppressed, and the components of the heat-sensitive layer are removed. The following treatments can be performed for the purpose of suppressing residual film, improving the strength of the anodic oxide film, improving the hydrophilicity of the anodic oxide film, improving the adhesion to the heat-sensitive layer, and the like. One of them is a silicate treatment in which an anodized film is brought into contact with an aqueous solution of an alkali metal silicate for treatment. In this case, the concentration of the alkali metal silicate is 0.1 to 30% by weight, preferably 0.5 to 15% by weight, and the pH at 25 ° C is 10 to 13.5. , Preferably 10 to 70 ° C, more preferably 15 to 50 ° C for 0.5 to 120 seconds. The contacting method may be any method such as dipping or spraying. The alkali metal silicate aqueous solution is p
When H is lower than 10, the liquid gels, and when H is higher than 13.5, the anodic oxide film is dissolved.

As the alkali metal silicate used in the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used. P of aqueous alkali metal silicate solution
Hydroxides used for H adjustment include sodium hydroxide, potassium hydroxide, lithium hydroxide and the like. The above-mentioned processing solution contains an alkaline earth metal salt or IVb.
A group metal salt may be blended. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate and borate. Is mentioned. Examples of Group IVb metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, and the like. The alkaline earth metal or Group IVb metal salt can be used alone or in combination of two or more. The preferred range of these metal salts is 0.01 to 10% by weight, and more preferably 0.05 to 5.0% by weight.

In addition, various types of sealing treatments can be mentioned. Steam sealing, boiling water (hot water) sealing, and metal salt sealing (generally known as methods for sealing an anodic oxide film) are also available. Chromate / dichromate seal, nickel acetate seal, etc.), oil impregnated seal, synthetic resin seal, low temperature seal (by red blood salt or alkaline earth salt, etc.) can be used. , Performance as a support for a printing plate (adhesion with a heat-sensitive layer and hydrophilicity),
From the viewpoints of high-speed processing, low cost, and low pollution, steam sealing is relatively preferred. As the method, for example,
No. 176690 discloses a method for continuously or discontinuously applying pressurized or normal pressure steam to a anodic oxide film at a relative humidity of 70% or more and a steam temperature of 95 ° C. or more for about 2 to 180 seconds. And the like. As another sealing treatment method, a method of immersing or spraying the support in hot water or an aqueous alkali solution at about 80 to 100 ° C.,
Alternatively or subsequently, it can be dipped or sprayed with a nitrous acid solution. Examples of nitrites include Ia, IIa, IIb, IIIb, IVb, IVa, VIa of the periodic table.
a, VIIa, and VIII metal nitrites or ammonium salts, ie, ammonium nitrite, such as LiO ₂ , NaNO ₂ , KNO ₂ , M
g (NO ₂ ) ₂ , Ca (NO ₂ ) ₂ , Zn (NO ₃ ) ₂ , Al
(NO ₂ ) ₃ , Zr (NO ₂ ) ₄ , Sn (NO ₂ ) ₃ , Cr
(NO ₂ ) ₃ , Co (NO ₂ ) ₂ , Mn (NO ₂ ) ₂ , Ni
(NO ₂ ) _{2 and the} like are preferable, and alkali metal nitrite is particularly preferable. Two or more nitrites can be used in combination.

The processing conditions vary depending on the state of the support and the type of alkali metal, and cannot be uniquely determined.
For example, when sodium nitrite is used, the concentration is generally 0.001 to 10% by weight, more preferably 0.01 to 10% by weight.
1-2% by weight, bath temperature generally from room temperature to about 100 ° C
Before and after, more preferably at 60 to 90 ° C., and the treatment time may be generally selected from the respective ranges of 15 to 300 seconds, more preferably 10 to 180 seconds. Nitrous acid aqueous solution
H is preferably adjusted to 8.0 to 11.0, and particularly preferably adjusted to 8.5 to 9.5. To adjust the pH of the nitrous acid aqueous solution to the above range,
For example, it can be suitably prepared using an alkaline buffer or the like. Examples of the alkaline buffer include, but are not limited to, a mixed aqueous solution of sodium hydrogen carbonate and sodium hydroxide, a mixed aqueous solution of sodium carbonate and sodium hydroxide, a mixed aqueous solution of sodium carbonate and sodium hydrogen carbonate, and a mixed aqueous solution of sodium chloride and sodium hydroxide. Mixed aqueous solution,
A mixed aqueous solution of hydrochloric acid and sodium carbonate, a mixed aqueous solution of sodium tetraborate and sodium hydroxide, and the like can be suitably used. Further, as the alkaline buffer, an alkali metal salt other than sodium, for example, a potassium salt can be used.

After the silicate treatment or the sealing treatment as described above, the acidic aqueous solution treatment and the hydrophilic undercoat disclosed in JP-A-5-278362 are applied to improve the adhesion to the heat-sensitive layer. And Japanese Patent Application Laid-Open
An organic layer disclosed in Japanese Patent No. 282637 or JP-A-7-314937 may be provided.

After the above-mentioned treatment or undercoating is applied to the surface of the support, a back coat is provided on the back surface of the support, if necessary. As such a back coat, a coating layer comprising a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 is used. It is preferably used. Among these coating layers, Si (OCH ₃ ) ₄ , Si (OC
_{2 H 5) 4, Si (} OC 3 H 7) 4, Si (OC 4 H 9) is easily available and inexpensive alkoxy compounds of silicon such as _4, the coating layer of the obtained therefrom metal oxide in developing solution Excellent and particularly preferred.

The preferred characteristics of the lithographic printing plate support are center line average roughness of 0.10 to 1.2 μm. When the thickness is less than 0.10 μm, the adhesion to the heat-sensitive layer decreases,
Significant reduction in printing durability occurs. If it is larger than 1.2 μm, the stain on printing will be deteriorated. Further, the color density of the support is 0.15 to 0.5 as a reflection density value.
65, and when it is whiter than 0.15, the halation at the time of image exposure is too strong and hinders image formation.
If it is less than 0.65, the image is difficult to see in the plate inspection work after development, and the plate inspection is extremely poor.

The lithographic printing plate precursor of the present invention can obtain better on-press developability by using, as a support, an aluminum substrate which has been subjected to a surface roughening treatment and then subjected to an anodic oxidation treatment. be able to. In that case, it is more preferable to use an aluminum substrate further subjected to a silicate treatment.

The present printing plate is made of a hydrophilic layer insoluble in water on an aluminum substrate, a hydrophilic layer which generates heat by laser exposure and is insoluble in water, or an organic polymer for imparting heat insulation to the aluminum substrate. In addition to the above heat-insulating layer, a hydrophilic layer insoluble in water or a hydrophilic layer that generates heat by laser exposure and is insoluble in water may be provided. For example, a hydrophilic layer of silica fine particles and a hydrophilic resin may be provided on an aluminum substrate. Further, the above-mentioned photothermal conversion material may be introduced into the hydrophilic layer to form a heat-generating hydrophilic layer. This makes it difficult for heat to escape to the aluminum substrate, or it can be used as a hydrophilic substrate that generates heat by laser exposure. Further, when an intermediate layer made of an organic polymer is provided between the hydrophilic layer and the aluminum substrate, the escape of heat to the aluminum substrate can be further suppressed. The support is preferably non-porous from the viewpoint of on-press developability, and a support which swells with water containing 40% or more of a hydrophilic organic polymer material is difficult to be dispensed with ink. turn into.

The hydrophilic layer used in the present invention is three-dimensionally cross-linked, is a layer which is insoluble in soaking water in lithographic printing using water and / or ink, and preferably comprises the following colloids. It is a colloid comprising a sol-gel conversion system of an oxide or hydroxide of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony or a transition metal. In some cases, a colloid composed of a complex of these elements may be used. These colloids have a structure in which the above elements form a network structure via an oxygen atom and have an unbonded hydroxyl group or alkoxy group at the same time, and these are mixed. From the initial hydrolysis-condensation stage where there are many active alkoxy groups and hydroxyl groups, as the reaction proceeds, the particle size increases and becomes inactive. Colloidal particles are generally between 2 nm and 500 nm, 5% for silica.
Spherical ones of nm to 100 nm are preferred in the present invention. 100 × 10nm like aluminum colloid
Such a feather-like material is also effective. Furthermore, 10 nm
A pearl neck-shaped colloid in which spherical particles having a length of 50 to 400 nm are connected in a length of 50 to 400 nm can also be used.

The colloid may be used alone,
Furthermore, it is also possible to mix and use with a hydrophilic resin. Further, a colloidal crosslinking agent may be added to promote crosslinking. Usually, colloids are often stabilized by stabilizers. In a colloid charged with a cation, a compound having an anionic group is added as a stabilizer, and in a colloid charged with an anion, a compound having a cationic group is added as a stabilizer. For example, a silicon colloid is charged with an anion, so an amine compound is added as a stabilizer, and an aluminum colloid is charged with a cation, so a strong acid such as hydrochloric acid or acetic acid is added. When such a colloid is applied on a substrate, it often forms a transparent film at room temperature, but gelation is incomplete by evaporating the solvent of the colloid, and by heating to a temperature at which the stabilizer can be removed by heating By performing strong tertiary cross-linking, it becomes a hydrophilic layer preferable in the present invention.

Without using a stabilizer as described above, a hydrolysis / condensation reaction is directly carried out from a starting material (for example, di, tri and / or tetraalkoxy silane) to form an appropriate sol state and directly onto a substrate. The reaction may be completed by coating and drying. In this case, three-dimensional crosslinking can be performed at a lower temperature than when a stabilizer is included.

In addition, a colloid obtained by dispersing and stabilizing an appropriate hydrolysis-condensation reaction product in an organic solvent is also suitable for the present invention. Only by evaporation of the solvent, a three-dimensionally crosslinked film is obtained. If a low-boiling solvent such as methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether or methyl ethyl ketone is selected as these solvents, drying at normal temperature becomes possible. In particular, in the present invention, the colloid of a methanol or ethanol solvent is easily cured at a low temperature and is useful.

As the hydrophilic resin used together with the above colloid, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl and carboxymethyl are preferable. Specific hydrophilic resins include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and their Na salts, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids And salts thereof, polymethacrylic acids and salts thereof, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate,
Hydroxypropyl acrylate homopolymers and copolymers, hydroxybutyl methacrylate homopolymers and copolymers, hydroxybutyl acrylate homopolymers and copolymers, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, and a degree of hydrolysis of at least 60% by weight; Preferably at least 80% by weight of hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, homopolymers and copolymers of acrylamide, homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide, 2-acrylamide- 2
And homopolymers and copolymers of methylpropanesulfonic acid or a salt thereof.

Particularly preferred hydrophilic resins are non-water soluble hydroxyl group-containing polymers, specifically, hydroxyethyl methacrylate homopolymers and copolymers and hydroxyethyl acrylate copolymers. These hydrophilic resins are used together with a colloid, and the addition ratio thereof is 40% of the total solid content of the hydrophilic layer when the hydrophilic resin is water-soluble.
% By weight or less, and in the case of a hydrophilic resin that is not water-soluble, preferably 20% by weight or less of the total solid content.

These hydrophilic resins can be used as they are, but a crosslinking agent of a hydrophilic resin other than colloid may be added for the purpose of increasing the printing durability during printing. Examples of such a crosslinking agent for a hydrophilic resin include initial hydrolysis and condensate of formaldehyde, glyoxal, polyisocyanate and tetraalkoxysilane, dimethylol urea and hexamethylol melamine. In addition to the above-mentioned colloid of the oxide or hydroxide and the hydrophilic resin, a crosslinking agent which promotes the crosslinking of the colloid may be added to the hydrophilic layer of the present invention. As such a crosslinking agent, an initial hydrolysis condensate of tetraalkoxysilane, trialkoxysilylpropyl-N, N, N-trialkylammonium halide or aminopropyltrialkoxysilane is preferable. The addition ratio is 5% by weight of the total solids in the hydrophilic layer.
The following is preferred.

Further, a hydrophilic photothermal conversion material may be added to the hydrophilic layer of the present invention in order to enhance the heat sensitivity. A particularly preferred photothermal conversion material is a water-soluble infrared absorbing dye, and is a cyanine dye having a sulfonic acid group or an alkali metal base of sulfonic acid or an amine base of the formula (I). The addition ratio of these dyes is 1 to the total amount of the hydrophilic layer.
% To 20% by weight, more preferably 5% to 15% by weight.
% By weight.

The coating thickness of the three-dimensionally crosslinked hydrophilic layer of the present invention is preferably from 0.1 μm to 10 μm. More preferably, it is 0.5 μm to 5 μm. If it ’s too thin,
The durability of the hydrophilic layer is poor, and the printing durability during printing is poor. On the other hand, if the thickness is too large, the resolution is reduced. Hereinafter, the intermediate layer made of an organic polymer will be described. The organic polymer that can be used for the intermediate layer can be used without any problem as long as it is a commonly used organic polymer such as a polyurethane resin, a polyester resin, an acrylic resin, a cresol resin, a resole resin, a polyvinyl acetal resin, and a vinyl resin. It is preferred that these are the coating weight of ^{0.1g / m 2 ~5.0g / m 2} . If it is 0.1 g / m ² or less, the heat insulating effect is small, and if it is more than 5.0 g / m ² , the printing durability of the non-image portion is deteriorated.

The lithographic printing plate precursor of the present invention can form an image by high-power laser exposure, but a writer such as a thermal head may be used. In particular, in the present invention, it is preferable to use a laser that emits light in the infrared or near-infrared region. In particular, a laser diode that emits light in the near infrared region is particularly preferable. Further, recording with an ultraviolet lamp is also possible, but in the present invention, the wavelength is 760 nm.
It is preferable to perform image exposure using a solid-state laser and a semiconductor laser that emit infrared rays of from 1200 to 1200 nm. The output of the laser is preferably 100 mW or more, and in order to shorten the exposure time, it is preferable to use a multi-beam laser device. Further, the exposure time per pixel is preferably within 20 μsec. The energy applied to the recording material is preferably from 10 to 300 mJ / cm ² .

The plate thus exposed is mounted without processing on a cylinder of a printing press.
The plate thus attached can be printed by the following procedure. (1) A method of supplying a dampening solution to the printing plate and developing it on the machine, and then supplying ink to start printing. (2) Supplying a dampening solution and the ink to the printing plate and developing on the machine. And (3) a method in which ink is supplied to the plate and dampening water is supplied, and at the same time, paper is supplied and printing is started. These plates are disclosed in Japanese Patent No. 2938398.
As described in the above item, after being mounted on the printing press cylinder, it is also possible to expose by a laser mounted on the printing press and then apply on-press development with dampening water and / or ink. Preferably, it can be developed with water or an aqueous solution, or can be directly mounted on a printing machine without being developed for printing.

[0138]

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these examples. Examples 1 to 6 Comparative Examples 1 to 3 Preparation of Support (1) (Preparation of Aluminum Substrate) 99.5% or more of aluminum, 0.30% of Fe,
i. A JIS A1050 alloy melt containing 0.10%, Ti 0.02%, and Cu 0.013% is subjected to a cleaning treatment,
Cast. In the cleaning treatment, a degassing treatment was performed to remove unnecessary gases such as hydrogen in the molten metal, and a ceramic tube filter treatment was performed. The casting was performed by DC casting. 10mm from the surface of a solidified ingot with a thickness of 500 mm
The surface was m-polished and homogenized at 550 ° C. for 10 hours so that the intermetallic compound was not coarsened. Then 40
After hot rolling at 0 ° C. and intermediate annealing in a continuous annealing furnace at 500 ° C. for 60 seconds, cold rolling was performed to obtain a rolled aluminum sheet having a sheet pressure of 0.30 mm. The center line average surface roughness Ra after cold rolling was controlled to 0.2 μm by controlling the roughness of the rolling roll. Then, it was subjected to a tension leveler to improve the flatness.

Next, a surface treatment was performed to obtain a lithographic printing plate support. First, in order to remove the rolling oil on the aluminum plate surface, a 10% aqueous solution of sodium aluminate was used at 50 ° C. for 30 minutes.
A degreasing treatment was performed for 2 seconds, a neutralization was performed with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds, and a smut removal treatment was performed.

Next, in order to improve the adhesion between the support and the heat-sensitive layer and to impart water retention to the non-image area, a so-called graining treatment was performed to roughen the surface of the support. 1%
Aqueous solution containing 0.5% nitric acid and 0.5% aluminum nitrate
° C while flowing an aluminum web in an aqueous solution, the anode-side electricity quantity 240 C / dm ² with an alternating waveform having a current density of 20 A / dm ² and a duty ratio of 1: 1 by an indirect feeding cell.
Electrolytic graining was performed by giving ² . Then 10%
Etching was performed with a sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization and smut removal were performed with a 30% aqueous sulfuric acid solution at 50 ° C. for 30 seconds. (Aluminum substrate A)

[0141] Further improved abrasion resistance, chemical resistance and water retention
To form an oxide film on the support by anodic oxidation.
Was completed. 20% aqueous sulfuric acid solution at 35 ° C as electrolyte
Indirect power supply while passing aluminum web through electrolyte
14 A / dm depending on the cell^TwoElectrolytic treatment with direct current
2.5g / m^TwoWas prepared. (Aluminum
After that, in order to ensure hydrophilicity as a non-image portion of the printing plate,
A silicate treatment was performed. The treatment was No. 3 sodium silicate.
A 5% aqueous solution was maintained at 70 ° C, and the contact time of the aluminum web was 1
It was transported for 5 seconds and further washed with water. Si adhesion amount
Is 10 mg / m ^TwoMet. Support created by the above
Had a Ra (center line surface roughness) of 0.25 μm.
(Aluminum substrate C)

Preparation of Support (2) (Preparation of Support Having an Exothermic Hydrophilic Layer on an Aluminum Substrate) Methanol silica sol (manufactured by Nissan Chemical Co., Ltd .: 30 weight% silica particles of 10 nm to 20 nm) in 240 g of methanol % Colloid consisting of a methanol solution containing 45.2%)
g, poly 2-hydroxyethyl methacrylate 1.52
g, 3.2 g of the infrared absorbing dye (I-32) was dissolved, and a bar was applied onto the previously obtained aluminum substrate C. It was dried in an oven at 100 degrees for 30 seconds. The coating amount was 1.0 g / m ² .

Preparation of Support (3) (Preparation of Support Having Heat Insulating Layer Provided on Aluminum Substrate and Heat-Producing Hydrophilic Layer) Application of Heat Insulating Layer 100 g of methyl ethyl ketone Dissolve 10 g of polyvinyl butyral resin in 90 g of methyl lactate Then, bar coating was performed on the previously obtained aluminum substrate C. It was dried in an oven at 100 degrees for 1 minute. 0.5g /
It was m ^2. Coating of exothermic hydrophilic layer Methanol silica sol 45.2 in 240 g of methanol
g, poly 2-hydroxyethyl methacrylate 1.52
g and 3.2 g of the infrared absorbing dye (I-32) were dissolved, and a bar was applied on the previously obtained heat insulating layer. It was dried in an oven at 100 degrees for 30 seconds. The coating amount is 1.
It was 0 g / m ² .

Synthesis of Particulate Polymer Not Combined by Heat Synthesis of Particulate Polymer Not Combined by Heat (1) 7.5 g of glycidyl methacrylate, trimethylol
3.5 g of lopan triacrylate, methyl methacrylate
4.0 g of polyoxyethylene phenol aqueous solution (concentration
9.84 × 10^-3mol·l^-1) Add 200 ml and add 2
Replace the inside of the system with nitrogen gas while stirring at 50 rpm.
You. After the temperature of the solution was raised to 25 ° C, cerium (IV) ammonium
Um salt aqueous solution (concentration 0.984 × 10^-3mol·l^-1)
Add 10 ml. At this time, aqueous ammonium nitrate solution
(Concentration 58.8 × 10^-3mol·l ^-1) And add PH
Adjust to 1.3-1.4. Then stir it for 8 hours
Was. The liquid thus obtained has a solid content of 9.5%.
And the average particle size was 0.4 μm. Synthesis of heat-unionable particulate polymer (2) 7.5 g of allyl methacrylate, 5.5 g of styrene,
2.0 g of vinylbenzene was polymerized in the same manner. this
The solid content of the liquid thus obtained is 9.5%.
As a result, the average particle size was 0.4 μm. Synthesis of particulate polymer that unites by heat (3) (Comparison
Example) (having no reactive group) 15 g of styrene was polymerized in the same manner. Like this
The solid content of the solution obtained was 9.0%, and the average particle size was
Was 0.3 μm.

Coating of heat-sensitive layer On the supports (1), (2) and (3) prepared as described above, the following compositions containing the fine-particle polymers of Synthesis Examples (1) to (3) were prepared. A coating solution was prepared, and a heat-sensitive layer was applied.

Composition of coating solution for heat-sensitive layer 100 g of water 5 g of synthesized particulate polymer (1), (2), (3) 5 g (in terms of solid content) 0.5 g of polyhydroxyethyl acrylate (weight average molecular weight 25000) Infrared absorbing dye ( I-32) 0.3 g

After the above solution was applied to a bar, 1
It was dried under the conditions of 00 degrees and 60 seconds. The coating amount is 0.5 g / m
^{Was 2} . The lithographic printing plate thus obtained, which can be developed on-press, was used as a Trendsetter 3244VF (Creo) equipped with a water-cooled 40 W infrared semiconductor laser.
At S, the output is 9 W, the rotation speed of the outer drum is 210 rpm, the plate surface energy is 100 mJ / cm ² , and the resolution is 2400 dp.
After the exposure under the condition i, the plate was mounted on a cylinder of a printing machine Heidel SOR-M without developing treatment, a dampening solution was supplied, ink was supplied, and paper was further supplied to perform printing. All the plates could be developed on the machine without any problems and printing was possible. After aged at 60 ° C. for 3 days, the level of dirt on on-press development was examined. Table 1 shows the number of prints obtained on each plate.

[0148]

[Table 1]

From the above results, it was found that the fine particles of the polymer which did not unite due to heat used for image formation had better printing durability. Also, a support having an exothermic hydrophilic layer provided on an aluminum substrate, or a support having an adiabatic layer provided on an aluminum substrate and further having an exothermic hydrophilic layer provided thereon may have better printing durability. Do you get it.

Example 7 A coating solution for a heat-sensitive layer consisting of the following was coated on a support (3). Water 100 g Synthesized particulate polymer (2) 5 g (in terms of solid content) Polyacrylic acid 0.5 g (weight average molecular weight 25000) Sorbitol triacrylate 1.0 g Infrared absorbing dye (I-31) 0.3 g

When the plate thus obtained was exposed and printed in the same manner as in Examples 1 to 6, 20,000 sheets could be printed normally.

Example 8 A heat-sensitive layer coating solution having the following composition was applied onto a support (3).

Water 100 g Synthesized particulate polymer (1) 5 g (in terms of solid content) Polyacrylic acid 0.5 g (weight average molecular weight 25000) Diethylenetriamine 1.0 g Infrared absorbing dye (I-31) 0.3 g

The plate obtained in this manner was applied to a Luxel T-9000CTP manufactured by Fuji Photo Film Co., Ltd. equipped with a multi-channel laser head, with an output of 250 mW per beam and an external drum rotation speed of 800.
Exposure was performed under the conditions of rpm and resolution of 2400 dpi. When printing was performed in the same manner as in Examples 1 to 6, 30,000 sheets of normal printing could be performed.

Examples 9 to 11 Preparation of a lithographic printing plate precursor, image exposure, and printing were performed in the same manner as in Example 1 except that the aluminum substrates A to C obtained by the step of forming the support (1) were used. And the on-press developability was evaluated. The on-press developability was determined by observing up to what percentage a shadow portion of a halftone dot of 150 lines / inch in the 100th printed matter from the start of printing could be reproduced, and the higher the value, the better. The results are shown in Table 2 below.

[0156]

[Table 2]

From Table 2 above, it was found that the use of an anodized aluminum substrate and a silicate-treated aluminum substrate as the support was more excellent in on-press developability.

[0158]

The lithographic printing plate precursor according to the present invention is characterized in that the heat-sensitive layer provided on the hydrophilic support does not combine with the heat used for image formation and has a functional group or a functional group present in another fine particle polymer. By containing a particulate polymer having a functional group capable of reacting with a functional group present in other components in the heat-sensitive layer, it is possible to provide a printed matter having high sensitivity, high printing durability, no residual color and no stain. In addition, good on-press developability including aging was exhibited, and more printed matter could be obtained. Further, by making the heat-sensitive layer further contain a light-to-heat conversion material or providing a layer containing the light-to-heat conversion material between the support and the heat-sensitive layer, plate making by scanning exposure based on digital signals becomes possible. Further, by using an aluminum substrate which has been subjected to anodizing treatment and further to silicate treatment as the support, better on-press developability could be exhibited.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/09 501 G03F 7/09 501 F term (Reference) 2H025 AA00 AA01 AA12 AB03 AC08 AD01 CB54 CC20 DA18 EA01 FA03 2H096 AA07 AA08 BA16 BA20 CA01 CA03 CA20 EA04 2H114 AA04 AA14 AA22 AA24 BA01 DA04 DA15 DA25 DA26 DA51 DA52 EA03 FA16 GA09 GA22 GA34 GA38

Claims (3)

[Claims] 1. A lithographic printing plate precursor comprising a hydrophilic support and a heat-sensitive layer containing a fine particle polymer that is not united by heat used for image formation, wherein the heat-sensitive layer contains another polymer in the fine particle polymer. A lithographic printing plate precursor characterized in that the lithographic printing plate precursor has a functional group present in the fine particle polymer or a functional group capable of reacting with a functional group present in another component in the thermosensitive layer. 2. The lithographic printing plate precursor according to claim 1, wherein the hydrophilic support is an aluminum substrate which has been subjected to a surface roughening treatment and then subjected to an anodic oxidation treatment. 3. The aluminum substrate further subjected to a silicate treatment.
The lithographic printing plate precursor described.