JP2001083692A - Original plate for heat sensitive planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an original plate for heat sensitive planographic printing plate which suppresses the flying of residue on the ablation of the heat sensitive layer in laser exposure without causing the deterioration of performance as a printing plate such as the lowering of sensitivity and hardly contaminates an exposure device and an optical system. SOLUTION: A three-dimensionally crosslinked hydrophilic layer whose heated part is easily removed with dampening water or ink in printing and a water-soluble overcoat layer are successively disposed on a substrate having an ink receiving surface or coated with an ink receiving layer to obtain the objective original plate for a heat sensitive planographic printing plate. A photothermal converting agent is contained in the crosslinked hydrophilic layer and/or the ink receiving layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a direct heat-sensitive lithographic printing plate precursor for offset printing which does not require development and has excellent printing durability. More specifically, it is possible to record an image by scanning exposure based on a digital signal, and the recorded image can be directly attached to a printing machine and printed without going through a conventional liquid developing process. It relates to a lithographic printing plate precursor.

[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 such a lithographic printing plate, a PS plate in which a lipophilic photosensitive resin layer is provided on a hydrophilic support has been widely used. As a plate making method, usually, after exposing through an original such as a lith film, a non-image portion is dissolved and removed with a developing solution, and a desired printing plate is obtained by this method.

[0003] The plate making process in the conventional PS plate requires an operation of dissolving and removing a non-image portion after exposure, and it is necessary to eliminate or simplify such additional wet processing. This is one problem that has been desired to be improved over the conventional technology. In particular, in recent years, the disposal of waste liquid discharged from wet processing has become a major concern of the entire industry due to consideration for the global environment, and the demand for improvement in this aspect has been further increased.

[0004] As one of the simple plate making methods responding to this demand, an image recording layer is used which enables the non-image portion of a printing plate to be removed in a normal printing process. And a method for obtaining a final printing plate has been proposed. The lithographic printing plate making method by such a method is called an on-press development method. Specific examples of the method include a method of using an image recording layer soluble in a fountain solution or an ink solvent, and a method of mechanically removing the image recording layer by contact with an impression cylinder or a blanket cylinder in a printing press. However, in the conventional on-press developing method of an image recording method using ultraviolet light or visible light, since the image recording layer is not fixed even after exposure, for example, the original plate is completely shielded from light until it is mounted on a printing press. Alternatively, it was necessary to take a time-consuming method such as preservation under constant temperature conditions.

On the other hand, another trend in this field in recent years is that digitization technology for electronically processing, storing, and outputting image information using a computer has become widespread. In response to technology,
Various new image output methods have come into practical use. Along with this, a computer that carries digitized image information in high-convergent radiation such as laser light, scans and exposes the original plate with this light, and directly manufactures a printing plate without passing through a lith film. Attention has been focused on to-plate technology. Accordingly, obtaining an original plate for a printing plate adapted to this purpose has become an important technical problem. Therefore, simplification, drying, and non-processing of plate making operations are more and more desired than ever in view of both the above-mentioned environmental aspects and adaptation to digitization.

Recently, as a method of manufacturing a printing plate by scanning exposure which is easy to incorporate into digital technology, semiconductor lasers,
Since high-power solid-state lasers such as YAG lasers have become available at low cost, plate-making methods using these lasers as image recording means have become particularly promising. In the conventional plate-making method, image recording is performed by applying imagewise exposure of the photosensitive original plate at low to medium illuminance and changing the image-like physical properties of the original plate surface by a photochemical reaction. In the method using density exposure, a large amount of light energy is intensively irradiated onto an exposure area during an instantaneous exposure time, the light energy is efficiently converted into heat energy, and the heat causes chemical change, phase change,
A thermal change such as a change in form or structure is caused, and the change is used for image recording. That is, image information is input by light energy such as laser light, while image recording is recorded by a reaction by heat energy. Usually, a recording method utilizing heat generated by such high power density exposure is called heat mode recording, and converting light energy into heat energy is called photothermal conversion.

The major advantages of the plate making method using the heat mode recording means are that the plate making method is not sensitive to light having a normal illuminance level such as room illumination, and that an image recorded by high illuminance exposure does not require fixing. . In other words, if a heat mode photosensitive material is used for image recording, it is safe against room light before exposure, and it is not essential to fix an image after exposure. Therefore, for example, if an image recording layer that is insolubilized or solubilized by heat mode exposure is used, and a plate-making process of removing the exposed image recording layer imagewise to form a printing plate is performed by an on-press development method, development (non-image Part removal) enables a printing system in which the image is unaffected for some time after image exposure, even if exposed to room ambient light. Therefore, if heat mode recording is used, it is expected that a lithographic printing plate precursor that is desirable for an on-press development system can be obtained.

[0008] As one of the preferred methods for producing a lithographic printing plate based on heat mode recording, a hydrophobic image recording layer is provided on a hydrophilic substrate, and is subjected to heat mode exposure in the form of an image. A method has been proposed in which the dispersibility is changed and, if necessary, the non-image areas are removed by wet development. As an example of such an original plate, for example, Japanese Patent Publication No. 46-279
No. 19 discloses an original plate provided with a recording layer having a so-called positive action in which solubility is improved by heat, specifically a recording layer having a specific composition such as a saccharide or a melamine formaldehyde resin, on a hydrophilic support. A method for obtaining a printing plate by performing heat mode recording is disclosed.

[0009] WO 98/40212 discloses that
There is disclosed a lithographic printing plate precursor in which a hydrophilic layer composed of a transition metal oxide colloid is provided on a substrate coated with an ink-receiving layer containing a photothermal conversion agent, and plate making can be performed without development. This is that the hydrophilic layer made of the transition metal oxide colloid is ablated (scattered) and removed by the heat generated by the photothermal conversion agent in the exposed portion. In addition, JP-A-55-105560 and WO9
No. 4/18005 discloses a lithographic printing plate in which a hydrophilic layer to be ablated in the same manner as described above is provided on a substrate coated with a lipophilic light-to-heat conversion layer.

Further, WO99 / 19143 and WO99 / 19143
JP-A-99 / 19144 discloses a lithographic printing plate precursor in which a photothermal conversion agent is added to a hydrophilic layer composed of an upper colloid for the purpose of increasing the sensitivity of the heat-sensitive lithographic printing plate to be ablated.

[0011]

However, these heat-sensitive lithographic printing plates utilizing conventional ablation are:
The laser exposure apparatus and the optical system are contaminated by scattering of the ablation debris, thereby reducing the resolving power and scattering the debris outside the apparatus.

[0012] EP0816070 describes ablation suppression. That is, on a hydrophilic support, an image forming layer in which hydrophobic thermoplastic polymer particles and a photothermal conversion agent are dispersed in a hydrophilic binder, and a water-soluble or water-swellable protective layer made of a hydrophilic polymer are further provided thereon. It is described that in a heat-sensitive recording element, the protective layer suppresses ablation. However, this patent discloses that the image forming layer is made water-insoluble by heat-melting the hydrophobic thermoplastic polymer particles by the heat generated by laser irradiation. In this method, secondary ablation that occurs in parallel with the thermal melting of the polymer particles in the irradiation section damages the image area and deteriorates the print quality, so that the protection layer suppresses ablation. Unlike this patent,
In the “ablation method” in which ablation is caused by laser irradiation to remove an irradiated portion, generation of scum is inevitable, and measures against scattering of scum have been performed by providing an ablation scum trapping device in the exposure device for the generated scum.
However, it was difficult to completely remove the contamination even if a capturing device was provided.

Plate making using heat mode image recording
The printing method has the advantages that the printing plate can be made directly from under the plate without the use of a film, so that the plate can be made on-press, and the developing operation can be omitted. It has more or less such disadvantages.

An object of the present invention is to solve the drawbacks of the conventional heat mode plate making method using laser exposure. In other words, it is possible to perform scanning exposure in a short time, and furthermore, it is possible to directly mount and print on a printing press without performing a developing process, and it is excellent in printing durability and heat-sensitive without contamination in printing. To provide a lithographic printing plate precursor. Another object of the present invention is to suppress scattering of ablation scum of a heat-sensitive layer during laser exposure without deteriorating performance as a printing plate such as a decrease in sensitivity while using ablation as a means of image formation, and to provide an exposure device or an optical device. It is an object of the present invention to provide a heat-sensitive lithographic printing plate precursor with less system contamination.

[0015]

In order to solve the above-mentioned problems, the present inventor has solved the above-mentioned problem, in which only the heating section is provided with a water-soluble layer on a three-dimensionally crosslinked hydrophilic layer which is easily removed by fountain solution or ink during printing. By providing an overcoat, sensitivity, printing durability,
The present inventors have discovered that scattering of scum due to ablation of the hydrophilic layer can be suppressed without impairing printability and on-press development processing properties, and completed the present invention.

1. On a substrate having an ink receptive surface or an ink receptive layer coated, a three-dimensionally cross-linked hydrophilic layer and a water-soluble overcoat layer in which only a heating portion is easily removed by a fountain solution or ink during printing are provided. A heat-sensitive lithographic printing plate precursor which is sequentially provided, wherein the heat-sensitive lithographic printing plate precursor contains a photothermal conversion agent in a crosslinked hydrophilic layer and / or ink receiving layer.

2. The crosslinked hydrophilic layer contains a colloid of at least one compound selected from oxides or hydroxides of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. 2. The heat-sensitive lithographic printing plate precursor as described in 1 above, wherein

3. The crosslinked hydrophilic layer is hydrophilic with a colloid of at least one compound selected from oxides or hydroxides of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. 2. The heat-sensitive lithographic printing plate precursor as described in 1 above, further comprising a hydrophilic resin.

4. 4. The heat-sensitive lithographic printing plate precursor as described in 3 above, wherein the hydrophilic resin is a homo- or copolymer of hydroxyalkyl acrylate or hydroxyalkyl methacrylate.

In the present invention, the crosslinked hydrophilic layer is ablated (scattered) by the overcoat layer present thereon due to the heat generated by the photothermal conversion agent in the ink receiving layer and / or the crosslinked hydrophilic layer by laser exposure. Although it does not occur, it is easily removed by the subsequent fountain solution or ink, and the image portion is formed by peeling off from the lower ink receiving layer. Although the details of this mechanism are not clear, in the present invention, the phenomenon described above is referred to as "ablation-like" removal or peeling of the hydrophilic layer. In practice, the hydrophilic layer is suppressed from ablation (scattering) by the upper overcoat layer, and is visually observed to form an image during printing due to a decrease in adhesion to the lower ink receiving layer.

In the present invention, the hydrophilic layer that has been ablated and removed from the ink receiving layer is removed by a fountain solution or ink during printing. Before that, of course, the upper overcoat layer is removed by a dampening solution. At this time, the lower ink receiving layer appears due to the removal of the hydrophilic layer that has been ablated and removed, and the image portion is removed. Become. The unexposed portion receives water while maintaining hydrophilicity and repels the ink. In this manner, printing can be performed simultaneously with development on the printing press. There is no need for wet processing with a developing solution as in conventional lithographic printing plates. That is, after exposure, a lithographic printing plate to be hung on a printing machine without processing is created.

As described above, scattering due to ablation of the hydrophilic layer can be suppressed without adversely affecting sensitivity, printing durability, and printability. By suppressing scattering due to ablation, contamination of the optical system of the laser exposure device and scattering of ablation spill outside the device are eliminated,
It is not necessary to attach a device for collecting a special ablation dust to the device.

Further, the printing plate is often left in the air for a long period of time or is handled by hand with ink on it until it is mounted on a printing press after exposure, and lipophilic substances often adhere to the plate. . In a conventional development processing system, the plate surface is covered and protected with a water-soluble substance in the last gumming step of the processing to prevent the lipophilic substance from adhering and contaminating. On the other hand, in the case of an untreated printing plate, since there is no such a countermeasure against contamination, the hydrophilic surface layer is directly contaminated, and there is a problem that printing stain is easily generated. However, by providing a water-soluble overcoat layer on the uppermost layer as in the present invention, adhesion of the lipophilic substance to the hydrophilic layer serving as a non-image portion is prevented, and stain during printing is prevented. As described above, the provision of the overcoat layer solves the basic problem of the unprocessed direct printing plate at the same time.

[0024]

Embodiments of the present invention will be described below in detail.

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 or inorganic polymer compounds.
As the water-soluble organic or inorganic polymer compound used here, a film formed by coating and drying has a film-forming ability, specifically, polyvinyl acetate (having a hydrolysis rate of 65% or more). , 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-propanesulfone Acid and its alkali metal 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, methyl cellulose, 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.

In addition, a nonionic surfactant can be mainly added to the overcoat layer in the case of aqueous solution application for the purpose of ensuring uniformity of application. Specific examples of such a nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecyl ether, and the like. . The proportion of the nonionic surfactant in the total solid content of the overcoat layer is preferably 0.05 to 5% by weight, and more preferably 1 to 3% by weight.

The thickness of the overcoat layer used in the present invention is preferably from 0.05 μm to 4.0 μm, and more preferably from 0.1 μm to 1.0 μm. If it is too thick,
It takes time to remove the overcoat layer during printing,
In addition, a large amount of dissolved water-soluble resin affects the dampening solution, causing adverse effects such as the occurrence of roller strips during printing and the insufficiency of ink on the image area. If it is too thin, the film properties may be impaired.

The three-dimensionally crosslinked hydrophilic layer used in the present invention is a layer which is insoluble in fountain solution by lithographic printing using water and / or ink, and preferably comprises the following colloids. Beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony or a transition metal oxide or hydroxide is a colloid comprising a sol-gel conversion system. 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, which is rich in active alkoxy groups and hydroxyl groups, the particle size increases and becomes inactive as the reaction proceeds. 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, the colloid is often stabilized by a stabilizer. 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 only by evaporation of the colloid solvent, and by heating to a temperature at which the stabilizer can be removed, By performing strong tertiary crosslinking, a hydrophilic layer preferable in the present invention is obtained.

Without using the above-mentioned stabilizer, a hydrolysis and condensation reaction is directly carried out from a starting material (for example, di-, tri- and / or tetraalkoxysilane) 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 prepared 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 these solvents are low boiling solvents such as methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and methyl ethyl ketone,
Drying at normal temperature becomes possible. In particular, in the present invention, a 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 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 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-methylol acrylamide and the like. it can.

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 proportion of the hydrophilic resin is determined when the hydrophilic resin is water-soluble.
The total solid content of the hydrophilic layer is preferably 40% by weight or less, and in the case of a non-water-soluble hydrophilic resin, the total solid content is preferably 20% by weight or less.

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. Formaldehyde, crosslinking agent for such a hydrophilic resin,
Examples include initial hydrolysis and condensate of glioxal, polyisocyanate and tetraalkoxysilane, dimethylol urea and hexamethylol melamine.

The hydrophilic layer of the present invention may contain, in addition to the above-mentioned oxide or hydroxide colloid and the hydrophilic resin, a crosslinking agent which promotes the crosslinking of the colloid. As such a crosslinking agent, an initial hydrolysis condensate of tetraalkoxysilane, trialkoxysilylpropyl-N, N, N-trialkylammonium halide or aminopropyltrialkoxysilane is preferable. It is preferable that the addition ratio is 5% by weight or less of the total solid content of the hydrophilic layer.

Further, a light-to-heat converting agent may be added to the hydrophilic layer of the present invention in order to increase the heat sensitivity. The photothermal conversion agent may be any substance that absorbs light of 700 nm or more,
Various pigments and dyes can be used. As a pigment,
Commercial Pigment and Color Index (CI) Handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, 1977)
Annual Publication), “Latest Pigment Application Technology” (CMC Publishing, 1986)
Pigments described in "Printing Ink Technology" (CMC Publishing, 1984).

Examples of the type of pigment include black pigment, brown pigment, red pigment, purple pigment, blue pigment, green pigment, fluorescent pigment, metal powder pigment, and polymer-bound pigment. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelated azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments 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 surface treatment, or may be used after 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 with 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 them, carbon black whose surface is coated with a hydrophilic resin or silica sol is useful as a material which 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, "Senryo Binran" edited by Organic Synthetic Chemistry Association, 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-59-8.
4356, a cyanine dye described in JP-A-60-78787, a methine dye described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, etc. JP-A-58-1127
No. 93, JP-A-58-224793, and JP-A-59-4
No. 8187, JP-A-59-73996, JP-A-60-
No. 52940, JP-A-60-63744 and the like; naphthoquinone dyes described in JP-A-58-112792 and the like; British Patent 43
And cyanine dyes described in U.S. Pat.
The dyes described as formulas (I) and (II) in US Pat. No. 6,993 can be exemplified.

[0045]

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Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are a substituted or unsubstituted alkyl group; and Z ¹ and Z ² are a substituted or unsubstituted benzene ring or naphthalene ring. An atomic group to be formed; L is a substituted or unsubstituted methine group, and the substituent is an alkyl group having 8 or less carbon atoms, a halogen atom or an amino group, or the methine group is substituted on the two methine carbons. X may be a cyclohexene ring or a cyclopentene ring which may have a substituent formed by bonding the groups to each other, and the substituent is an alkyl group having 6 or less carbon atoms or a halogen atom; An anionic group; n is 1 or 2;
At least one of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , Z ¹ and Z ² represents an acidic group or a substituent having an alkali metal base or an amine base of the acidic group.

[0047]

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[Wherein, R ¹¹ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; R ¹² and R ¹⁵ are hydrogen atoms or substituted in place of hydrogen atoms; Possible groups: R ¹³ and R ¹⁴ are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkoxy group or a substituted or unsubstituted alkyl group, provided that R ¹³ and R ^14
14 are not hydrogen atoms at the same time: R ¹⁶ and R ¹⁷ are a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, an acyl group or a sulfonyl group, or R ¹⁶ and nonmetallic 5- or 6 R ¹⁷ 3 illustrates the formation of a member ring. ]

As a dye, US Pat. No. 5,156,
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, E
Pollite 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.

[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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The pigment or the dye accounts for 1% of the total solid content of the hydrophilic layer.
It is a proportion of ４０40% by weight, preferably 2-20% by weight. If the amount of the pigment or dye is less than the above range, the sensitivity is lowered, and if it is more than the above range, the hydrophilicity of the layer is impaired or the durability of the layer is deteriorated.

The coating thickness of the three-dimensionally crosslinked hydrophilic layer of the present invention is preferably from 0.1 μm to 3 μm. More preferably, it is 0.5 μm to 2 μm. If it ’s too thin,
The durability of the hydrophilic layer is poor, and the printing durability during printing is poor. If it is too thick, a large amount of energy is required to separate the hydrophilic layer from the lower ink receiving layer in an ablation manner, and a long drawing time is required when exposing with a laser,
The productivity of printing plates decreases. When writing is performed using a general commercially available semiconductor laser, energy of 300 to 400 mJ / cm ² is applied at a thickness of about 0.5 μm, and energy of 400 to 500 mJ / cm ² is applied at a thickness of about 1.5 μm. It costs.

The substrate having an ink receptive surface or the ink receptive layer to be used in the present invention includes:
A dimensionally stable plate is used. Paper, paper laminated with lipophilic plastics (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, nickel, stainless steel plate, etc.), and ink-receptive organic polymer resin applied Metal plates, plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.) The above-mentioned plastic film coated with an ink-receiving organic polymer resin, paper or a plastic film on which the above-mentioned ink-receiving metal is laminated or vapor-deposited, and the like are included.

A preferred substrate is a polyethylene terephthalate film, a polycarbonate film, an aluminum or steel plate coated with an ink-receptive organic polymer resin, or an aluminum or steel plate laminated with a lipophilic plastic film.

The aluminum plate suitable for use in the present invention is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of a different element. Is applied or an ink-receptive plastic is laminated. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium.
The content of the foreign element in the alloy is at most 10% by weight or less.
However, as the aluminum plate applied to the present invention, an aluminum plate of a conventionally known and used material can be appropriately used.

It is preferable to roughen the surface of the aluminum plate before using it. When applied to the ink receiving layer made of an organic polymer by roughening, adhesion to the substrate can be easily secured. For roughening, first, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution is performed to remove rolling oil on the surface of the aluminum substrate.

The surface roughening treatment of the aluminum plate is performed by various methods, for example, a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of chemically roughening the surface. Is selectively dissolved. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. The chemical method is described in JP-A-54-3118.
No. 7, a method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in JP-A No. 7 is suitable. As an electrochemical surface roughening method, there is a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Also, an electrolytic surface roughening method using a mixed acid as disclosed in JP-A-54-63902 can be used.

The surface roughening by the above-mentioned method is performed when the center line surface roughness (Ha) of the surface of the aluminum plate is 0.3-1.
It is preferable that the coating be performed within a range of 0 μm. The roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide or sodium hydroxide as necessary, and further neutralized, and then, if necessary, anodized to enhance abrasion resistance. Processing is performed.
As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used, and generally, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte. The anodizing treatment conditions vary depending on the electrolyte to be used and cannot be specified unconditionally, but generally the concentration of the electrolyte is 1 to 80% by weight.
Solution, liquid temperature is 5 to 70 ° C, current density is 5 to 60 A / dm ² ,
A voltage of 1 to 100 V and an electrolysis time of 10 seconds to 5 minutes are appropriate. The amount of the formed oxide film is 1.0-5.
0 g / m ^2, it is particularly preferably 1.5 to 4.0 g / m ^2.

The thickness of the substrate used in the present invention is about 0.05 mm to 0.6 mm, preferably about 0.1 mm to 0.6 mm.
mm to 0.4 mm, particularly preferably 0.15 mm to 0.4 mm.
3 mm.

The organic polymer applied as an ink receiving layer on the surface of the substrate according to the present invention is soluble in a solvent and capable of forming a lipophilic film. Furthermore,
It is desirable that it is insoluble in the coating solvent for forming the upper hydrophilic layer, but in some cases, one that swells in the upper layer coating solvent has excellent adhesiveness to the upper layer and may be desirable.
In addition, when an organic polymer that is soluble in the upper layer coating solvent is used, it is desirable to cure it in advance by adding a crosslinking agent or the like.

Examples of useful organic polymers include polyester, polyurethane, polyurea, polyimide, posisiloxane, polycarbonate, phenoxy resin, epoxy resin, phenol / formaldehyde resin, alkylphenol / formaldehyde resin, polyvinyl acetate, acrylic resin and copolymers thereof. Polyvinyl phenol, polyvinyl halogenated phenol, methacrylic resin and its copolymer, acrylamide copolymer, methacrylamide copolymer, polyvinyl formal, polyamide, polyvinyl butyral, polystyrene, cellulose ester resin, polyvinyl chloride and polyvinylidene chloride Can be mentioned. Among these, as a more preferred compound, a resin having a hydroxyl group, a carboxy group, a sulfonamide group or a trialkoxysilyl group in a side chain is excellent in adhesiveness to a substrate or an upper hydrophilic layer, and is easy to use with a crosslinking agent in some cases. It is desirable because it hardens to In addition, an acrylonitrile copolymer, polyurethane, a copolymer having a sulfonamide group in a side chain or a copolymer having a hydroxyl group in a side chain is preferably photocured with a diazo resin.

Other phenol, cresol (m-cresol, p-cresol, m / p mixed cresol), phenol / cresol (m-cresol, p-cresol, m / p mixed cresol), phenol-modified xylene, tert-butylphenol, A novolak resin and a resole resin of condensation with formaldehyde such as octylphenol, resorcinol, pyrogallol, catechol, chlorophenol (m-Cl, p-Cl), bromophenol (m-Br, p-Br), salicylic acid, and phloroglucinol; Further, a condensation resin of the above phenol compound and acetone is useful.

Other suitable high molecular compounds include copolymers having a molecular weight of usually 10,000 to 200,000, having the following structural units as monomers (1) to (12). (1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, for example, N- (4
-Hydroxyphenyl) acrylamide or N- (4
-Hydroxyphenyl) methacrylamide, o-, m-
And p-hydroxystyrene, o-, m- and p-
Hydroxyphenyl acrylate or methacrylate, (2) acrylates and methacrylates having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, (3) methyl acrylate, ethyl acrylate, acryl Propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, 4-hydroxybutyl acrylate, glycidyl acrylate, N- (Substituted) acrylates such as dimethylaminoethyl acrylate,

(4) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate,
Amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, methacrylic acid
(Substituted) methacrylates such as 2-chloroethyl, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate, (5) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N- Ethyl acrylamide, N-ethyl methacrylamide, N-hexyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide, N-hydroxyethyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N- Phenyl methacrylamide, N-benzylacrylamide, N
-Benzyl methacrylamide, N-nitrophenyl acrylamide, N-nitrophenyl methacrylamide, N
Acrylamide or methacrylamide such as -ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide,

(6) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and phenyl vinyl ether; (7) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate; (8) styrenes such as styrene, methyl styrene and chloromethyl styrene; 9)
Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone; (10) olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene; (11) N
-Vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc.

(12) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- [1- (3-aminosulfonyl) Naphthyl] acrylamide, acrylamides such as N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonyl) Methacrylamides such as phenyl) methacrylamide, N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacrylamide, and o-aminosulfonylphenyl acrylate, m-amino Sulfo sulfonyl phenyl acrylate,
p-aminosulfonylphenyl acrylate, 1- (3
-Aminosulfonylphenylnaphthyl) unsaturated sulfonamides such as acrylates such as acrylate, o-aminosulfonylphenylmethacrylate, m
Unsaturated sulfonamides such as methacrylic esters such as -aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate and 1- (3-aminosulfonylphenylnaphthyl) methacrylate;

These organic polymers can be dissolved in an appropriate solvent, applied to a substrate and dried to form an ink receiving layer on the substrate. The organic polymer alone can be used by dissolving it in a solvent, but it is usually used together with a crosslinking agent, an adhesion aid, a coloring agent, inorganic or organic fine particles, a coating surface condition improving agent, or a plasticizer. In addition, a light-to-heat conversion agent for increasing the sensitivity or a heating color-developing system or a decoloring system for forming a printout image after exposure may be added to the ink receiving layer.

Specific crosslinking agents for crosslinking organic polymers include diazo resins, aromatic azide compounds, epoxy resins, isocyanate compounds, blocked isocyanate compounds, initial hydrolyzed condensates of tetraalkoxy silicon, glyoxal, aldehyde compounds and methylol. Compounds can be mentioned.

As the adhesion aid, the above-mentioned diazo resin is excellent in adhesion to a substrate and a hydrophilic layer. In addition, a silane coupling agent, an isocyanate compound, and a titanium coupling agent are also useful.

As the coloring agent, ordinary dyes and pigments can be used. In particular, rhodamine 6G chloride, rhodamine B chloride, crystal violet, malachite green oxalate, oxazine 4 perchlorate, quinizarin,
2- (α-naphthyl) -5-phenyloxazole and coumarin-4. Specifically, as other dyes,
Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black B
Y, oil black BS, oil black T-505
(The above are manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI4255)
5), methyl violet (CI42535), ethyl violet, methylene blue (CI52015), patent pure blue (manufactured by Sumitomo Sangoku Chemical Co., Ltd.), brilliant blue, methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4
Triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes such as -p-diethylaminophenyliminaphthoquinone and cyano-p-diethylaminophenylacetanilide; -293247, Japanese Patent Application No. 7-335.
No. 145 can be mentioned.
When the above dye is added to the ink receiving layer, it is usually present in an amount of about 0.02 to 10% by weight, more preferably about 0.1 to 5% by weight, based on the total solid content of the receiving layer.

Further, fluorine-based surfactants and silicon-based surfactants, which are well-known compounds as coating surface condition improvers, can also be used. Specifically, a surfactant having a perfluoroalkyl group or a dimethylsiloxane group is useful for preparing the coated surface.

Examples of the fine inorganic or organic powder that can be used in the present invention include colloidal silica and colloidal aluminum having a diameter of 10 nm to 100 nm, and inert particles having a particle size larger than those of colloids such as silica particles and surface hydrophobic particles. Silica particles, alumina particles, titanium dioxide particles, other heavy metal particles, clay and talc. The addition of these inorganic or organic fine powders to the ink receiving layer has the effect of improving the adhesion to the upper three-dimensionally crosslinked hydrophilic layer and increasing the printing durability in printing. The proportion of these fine powders in the ink receiving layer is 80% by weight or less, preferably 40% by weight or less of the total amount.

Further, a plasticizer may be added to the ink receiving layer of 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, oligomers of acrylic acid or methacrylic acid And polymers.

Further, it is preferable to add a coloring or decoloring compound to the ink receiving layer of the present invention in order to sharpen an image area and a non-image area when exposed. For example, together with thermal acid generators such as diazo compounds and diphenyliodonium salts, leuco dyes (leucomalachite green, leuco crystal violet, lactones of crystal violet, etc.) and PH discoloration dyes (eg, ethyl violet, Victoria Poor Blue BOH, etc.) Dye) is used. In addition, a combination of an acid coloring dye and an acidic binder as described in EP 897134 is also effective. In this case, the bond in the associated state forming the dye is broken by heating, and a lactone is formed to change from colored to colorless. The addition ratio of these coloring systems is 10% by weight or less, preferably 5% by weight or less based on the total amount in the receiving layer.

Further, a light-to-heat converting agent may be added to the ink receiving layer of the present invention in order to increase the heat sensitivity. The photothermal conversion agent may be the above-mentioned infrared absorbing dye or pigment, but in this case, a lipophilic dye or pigment is preferable.
Particularly preferred are lipophilic ones of carbon black and the cyanine dyes represented by the above formula (I). Specific compounds of the lipophilic cyanine dye are listed below.

[0081]

Embedded image

The proportion of the photothermal conversion agent to the ink receiving layer is preferably 20% by weight or less of the total amount of the ink receiving layer.
5% by weight or less. If the amount of the pigment or dye added is more than the above range, the durability of the layer decreases.

As the solvent for coating the ink receiving layer, alcohols (methanol, ethanol, propyl alcohol, ethylene glycol, diethylene glycol,
Propylene glycol, dipropylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc.), ethers (tetrahydrofuran, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, tetrahydropyran, etc.), ketones (acetone, methyl ethyl ketone, Acetylacetone, etc.), esters (methyl acetate, ethylene glycol monomethyl monoacetate, etc.), amides (formamide, N-methylformamide, pyrrolidone, N-methylpyrrolidone, etc.), gamma-butyrolactone, methyl lactate, ethyl lactate, etc. it can. These solvents are used alone or in a mixed state. When preparing a coating solution, the concentration of the components of the ink receiving layer (total solids including additives) in the solvent is preferably 1 to 50% by weight. In addition, a film can be formed not only from the above-mentioned application from an organic solvent but also from an aqueous emulsion. In this case, the concentration is preferably 5% by weight to 50% by weight.

The thickness of the ink-receiving layer in the present invention after coating and drying is not particularly limited, but may be 0.1 μm or more. When it is provided on a metal plate, it has a role as a heat insulating layer, so that it is preferably 0.5 μm or more. If the ink receiving layer is too thin, the heat generated will dissipate toward the metal plate, lowering the sensitivity. In addition, in the case of a hydrophilic metal plate, the ink receiving layer is required to have abrasion resistance, so that the printing durability cannot be ensured. When a lipophilic plastic film is used as the substrate, the ink receiving layer only has to function as an adhesive layer with the upper layer, so the coating amount may be smaller than that of the metal plate, and may be 0.05 μm. The above is preferred.

Next, a method of making a heat-sensitive planographic printing plate will be described. The lithographic printing plate precursor may be, for example, directly subjected to image-wise thermal recording by a thermal recording head or the like, or a solid laser or semiconductor laser emitting infrared rays having a wavelength of 700 to 1200 nm, or a high-intensity flash light such as a xenon discharge lamp. Light-to-heat conversion type exposure such as infrared lamp exposure can also be used. Writing of an image may be performed by either a surface exposure method or a scanning method. In the former case,
This is an infrared irradiation method or a method of irradiating the original plate with high-intensity short-time light of a xenon discharge lamp to generate heat by light-heat conversion. When a surface exposure light source such as an infrared lamp is used, the preferable exposure amount varies depending on the illuminance, but usually, the surface exposure intensity before modulation with a print image is 0.1 to 10 J / cm ² . Preferably within the range,
More preferably, it is in the range of 0.1 to 1 J / cm ² .
When the support is transparent, exposure can be performed through the support from the back side of the support. The exposure time is 0.0
1-1 msec, preferably 0.01-0.1 msec
It is preferable to select the exposure illuminance so that the above-mentioned exposure intensity can be obtained by the irradiation. When the irradiation time is long, it is necessary to increase the exposure intensity due to the competition between the heat energy generation rate and the generated heat energy diffusion rate.

In the latter case, a method is used in which a laser light source containing a large amount of infrared components is used to modulate a laser beam with an image and scan the original plate. Examples of the laser light source include a semiconductor laser, a helium neon laser, a helium cadmium laser, and a YAG laser. Irradiation can be performed with a laser having a laser output of 0.1 to 300 W. When a pulse laser is used, it is preferable to irradiate a laser having a peak output of 1000 W, preferably 2000 W. In this case, the exposure amount is preferably such that the surface exposure intensity before modulation with the image for printing is in the range of 0.1 to 10 J / cm ² ,
More preferably, it is in the range of 0.3 to 1 J / cm ² .

The printing original plate of the present invention can be mounted on a printing press without further processing the image-exposed printing original plate. When printing is started using ink and water, the overcoat layer is removed by the dampening solution, and at the same time the hydrophilic layer in the exposed area is removed. The ink is deposited on the ink receiving layer below the ink receiving layer, and printing is started.

[0088]

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

Example 1 (Preparation of aluminum substrate) 0.01% by weight of copper, 0.03% by weight of titanium,
JI containing 0.3% by weight of iron and 0.1% by weight of silicon
A roll of a 0.24 mm-thick sheet of SA1050 aluminum material was converted to a 400 mesh pumice stone (Kyoritsu Ceramics) 20
Weight percent aqueous suspension and a rotating nylon brush (6,10-
(Nylon) and the surface was grained, and then washed well with water. This was immersed in a 15% by weight aqueous sodium hydroxide solution (containing 4.5% by weight of aluminum), etched so that the amount of aluminum dissolved was 5 g / m ² , and washed with running water. Further, the mixture is neutralized with 1% by weight nitric acid, and then a 0.7% by weight aqueous nitric acid solution (0.5% by weight of aluminum)
), The voltage at the time of anode was 10.5 volts, and the voltage at the time of cathodes was 9.3 volts.
0, a current waveform described in Examples of JP-B-58-5796), and an electrolytic surface roughening treatment was carried out at an anode electricity amount of 160 clones / dm ² . After washing with water,
After being immersed in an aqueous solution of sodium hydroxide by weight and etched so that the amount of aluminum dissolved becomes 1 g / m ² ,
Washed with water. Next, it was immersed in a 30% by weight aqueous sulfuric acid solution at 50 ° C., desmutted, and washed with water. In addition, 35 ° C
A porous anodic oxide film was formed in a 20% by weight aqueous sulfuric acid solution (containing 0.8% by weight of aluminum) using a direct current. That is, electrolysis was performed at a current density of 13 A / dm ² , and the anodic oxide film weight was adjusted to 2.7 g / m ² by adjusting the electrolysis time. The support was washed with water, immersed in a 0.2% by weight aqueous solution of sodium silicate at 70 ° C. for 30 seconds, washed with water and dried. The aluminum substrate obtained as described above has a reflection density of 0,0 measured with a Macbeth RD920 reflection densitometer.
At 30, the center line average roughness was 0.58 μm.

(Synthesis of Organic Polymer for Ink-Receiving Layer) In a 200 ml three-necked flask equipped with a stirrer, a condenser, and a dropping funnel, 4.61 g (0.0192 mol) of N- (p-aminosulfonylphenyl) methacrylamide was placed. , 2.94 g (0.0258 mol) of ethyl methacrylate, 0.80 g (0.015 mol) of acrylonitrile, and 20 g of N, N-dimethylacetamide, and the mixture was stirred while being heated to 65 ° C. in a hot water bath. 0.15 g of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the mixture, and the mixture was stirred for 2 hours under a nitrogen stream while maintaining the temperature at 65 ° C. The reaction mixture was further charged with N- (p
-Aminosulfonylphenyl) methacrylamide 4.6
A mixture of 1 g, 2.94 g of ethyl methacrylate, 0.80 g of acrylonitrile, 0.15 g of N, N-dimethylacetamide and polymerization initiator V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) was dropped by a dropping funnel over 2 hours. did. After completion of the dropwise addition, the mixture was further stirred at 65 ° C. for 2 hours. After completion of the reaction, 40 g of methanol was added, and the mixture was cooled, poured into 2 L of water with stirring, stirred for 30 minutes, and filtered and dried to obtain 15 g of a white solid. The weight average molecular weight (polystyrene standard) of this N- (p-aminosulfonylphenyl) methacrylamide copolymer was measured by gel permeation chromatography and found to be 53,000.

(Preparation of Ink-Receiving Substrate)
After dissolving 3 g of (p-aminosulfonylphenyl) methacrylamide copolymer in a mixed solution consisting of 9.5 g of gamma-butyrolactone / 3 g of methyl lactate / 22.5 g of methyl ethyl ketone / 22 g of propylene glycol monomethyl ether, Coating was performed with a bar coater so that the coating liquid amount was 24 ml / m ² . After that, it is dried by heating at 100 ° C. for 1 minute, and the dry coating amount is about 1
An aluminum substrate having a g / m ² ink receiving layer was prepared.

(Preparation of a heat-sensitive lithographic printing plate)
1 g of a 10% solution of 2-hydroxyethyl methacrylate homopolymer (weight average molecular weight 250,000) in ethylene glycol monomethyl ether, methanol silica (manufactured by Nissan Chemical Co., Ltd .: 30 to 10 nm to 20 nm silica particles)
Colloid consisting of methanol solution containing 3% by weight) 3
g, the cyanine dye (I-31) 0.0 described in the specification.
A solution consisting of 8 g and 16 g of methanol was applied on the substrate coated with the ink receiving layer, and dried at 100 ° C. for 1 minute to form a three-dimensionally crosslinked hydrophilic layer having a dry coating weight of about 1 g / m ^2. It was provided above. An aqueous solution consisting of 20 g of a 5% aqueous solution of polyacrylic acid (weight average molecular weight: 25,000) and 0.025 g of polyoxyethylene nonylphenyl ether was applied thereon,
After drying for 2 minutes, a heat-sensitive planographic printing plate having an overcoat layer having a dry coating weight of about 0.6 g / m ² provided on the hydrophilic layer was prepared.

(Preparation of lithographic printing plate) The above lithographic printing plate was used as a 40 W trend setter (40
A 830 nm W semiconductor laser was mounted on a mounting plate setter) and irradiated with an energy of 300 mJ / cm ² . As a result of observing the plate surface after irradiation, there was almost no trace of the energy irradiation part scattered by ablation. The irradiated original plate was attached to a Harris printing machine, and printed with a dampening solution and ink containing a 10% by volume aqueous solution of isopropyl alcohol containing an etchant.
Good printed matter without stains on the prints was obtained.

Comparative Example 1 A heat-sensitive printing plate precursor for comparison was prepared by applying the hydrophilic layer of Example 1 and before applying the overcoat layer. This original plate was irradiated with a laser in the same manner as in Example 1, and then attached to the same printing machine to perform printing in the same manner. Observation of the plate surface after laser irradiation revealed that the hydrophilic layer of the irradiated portion was scattered clearly by ablation. In printing, 10,000 copies could be printed, but fingerprint marks, which were thought to have been touched by fingertips stained with ink when the plate was attached to the printing press, were generated.

Example 2 In place of 3 g of the methanol silica of Example 1, Glasca 40 was used.
1 (manufactured by Nissita Laboratories: a 20% by weight methanol colloid solution composed of ZrO ₂ · SiO ₂ ) was prepared in the same manner as in Example 1 except that 4.5 g of a heat-sensitive lithographic printing plate was obtained. This original plate was exposed in the same manner as in Example 1. Observation of the plate surface after exposure showed almost no trace of scattering by ablation. Then, when mounted and printed on a Harris printing machine, 10,000 copies of good printed matter without stains were obtained.

Example 3 To 4.5 g of the methanol silica of Example 1 was added 1.5 g of a 10% ethylene glycol monomethyl ether solution of 2-hydroxyethyl methacrylate homopolymer.
g, a heat-sensitive lithographic printing plate was obtained in the same manner as in Example 1, except that the cyanine dye (I-31) as a light-to-heat conversion agent was replaced with the cyanine dye (I-32) described in the present specification.
This printing plate had a dry coating weight of the crosslinked hydrophilic layer of about 1.5 g / m ² . The original plate was attached to a 40W trend setter of Canada CREO (a plate setter equipped with a 40W 830nm semiconductor laser) and 450m in length.
Irradiation with energy of J / cm ² was performed. Observation of the plate surface after irradiation showed almost no trace of scattering by ablation. The irradiated original plate was mounted on a Harris printing machine, and printed using a dampening solution and ink composed of a 10% by volume aqueous solution of isopropyl alcohol containing an etchant.
000 parts of good printed matter without stains were obtained.

Example 4 A copolymer consisting of 2-hydroxyethyl methacrylate / methyl methacrylate = 70/30% by weight instead of 1 g of a 10% ethylene glycol monomethyl ether solution of 2-hydroxyethyl methacrylate homopolymer of Example 1 ( A heat-sensitive lithographic printing plate was obtained in the same manner as in Example 1, except that 1 g of a 10% ethylene glycol monomethyl ether solution having a weight average molecular weight of 200,000) was used. This original plate was exposed in the same manner as in Example 1. Observation of the plate surface after exposure showed almost no trace of scattering by ablation. Then, when mounted and printed on a Harris printing machine, 15,000 copies of good prints without stains were obtained.

Example 5 Instead of 1 g of a 10% ethylene glycol monomethyl ether solution of 2-hydroxyethyl methacrylate homopolymer of Example 1, a copolymer consisting of 90% by weight of 2-hydroxyethyl methacrylate / 10% by weight of acrylic acid ( A heat-sensitive lithographic printing plate was obtained in the same manner as in Example 1, except that 2 g of a 10% ethylene glycol monomethyl ether solution having a weight average molecular weight of 300,000) was used. This original plate was exposed in the same manner as in Example 3. Observation of the plate surface after exposure showed almost no trace of scattering by ablation. Then, when mounted and printed on a Harris press, 20,000 copies of good printed matter without stains were obtained.

Examples 6 to 10 Instead of polyacrylic acid in the overcoat layer in Example 1, in Example 6, polysodium methacrylate (weight average molecular weight: 15,000), and in Example 7, polyvinyl alcohol (saponification degree) 88 mol%, degree of polymerization 1000), and in Example 8, poly-2-acrylamido-2-methyl-1-
Propanesulfonic acid (weight average molecular weight 15,000),
In Example 9, polyacrylamide (weight average molecular weight 1
000), and in Example 10, instead of 20 g of a 5% aqueous solution of polyacrylic acid, 4.5% of polyvinyl alcohol (98.8 mol% of saponification degree, polymerization degree of 500) and polyacrylic acid (weight average molecular weight of 25) were used. , 000) 0.5%
20 g of a mixed aqueous solution was used. In all other respects, a heat-sensitive planographic printing plate was obtained in the same manner as in Example 1. Then, the original plate was irradiated with laser in the same manner as in Example 1. Observation of the plate surface showed almost no trace of any plate scattered due to ablation from the irradiated portion. Then, it was attached to a Harris printing machine and printing was performed in the same manner as in Example 1. As a result, 10,000 copies of good printed matter without stain were obtained.

Examples 11 to 15 Instead of the N- (p-aminosulfonylphenyl) methacrylamide copolymer of Example 1, a phenoxy resin (trade name: Phenotote YP-50: Toto Kasei Co., Ltd.) was used in Example 11. Example 12), polyvinyl formal resin (trade name: Denka formal # 200: manufactured by Denki Kagaku Kogyo KK) in Example 12, polyurethane resin (trade name: Estan # 5715, manufactured by Monsanto Co.) in Example 13, and saturation in Example 14 Copolyester resin (trade name Chemit K-1)
294: manufactured by Toray Industries, Inc.), and in Example 15, methyl methacrylate / methacryloxypropyltriethoxysilane = 60/40% by weight copolymer (average weight molecular weight 8
5,000) was dissolved in a mixed solvent consisting of 37 parts by weight of methyl ethyl ketone and 20 parts by weight of propylene glycol monomethyl ether, and then Megafac F-177 (Dai Nippon Ink Chemical Industry Co., Ltd.) 0.04 parts by weight of a fluorinated surfactant manufactured by Co., Ltd.) were added to these coating solutions. The aluminum substrate of Example 1 was bar-coated so that the amount of the coating solution was 24 ml / m ² . Then 1
The resultant was dried by heating at 00 ° C. for 1 minute to prepare an aluminum substrate having an ink receiving layer having a dry coating amount of about 1 g / m ² . Then, a heat-sensitive lithographic printing original plate was obtained in the same manner as in Example 1 except that these substrates were used instead of the substrates of Example 1. The original plate was exposed in the same manner as in Example 1, and then mounted on a Harris press and printed.
0 parts of a good printed matter without stain was obtained. Observation of the plate surface after exposure showed almost no trace of scattering by ablation on any plate.

Examples 16 to 18 Ink-receiving substrates were prepared by replacing the coating solution of the ink-receiving layer of Example 1 with a cyanine dye as a light-to-heat converting agent as described below. Formulation of coating liquid for ink-receiving layer N- (p-aminosulfonylphenyl) methacrylamide copolymer 3 g cyanine dye 0.3 g gamma-butyrolactone 9.5 g methyl lactate 3 g methyl ethyl ketone 22.5 g propylene glycol monomethyl ether 22 g In Example 16, (I-
33), Example 17 describes (I-34) described in the present specification,
In Example 18, (I-37) described in this specification was used.

The same hydrophilic layer and overcoat layer as in Example 3 were applied on this substrate to prepare a heat-sensitive printing original plate. The original plate was exposed at an energy of 400 mJ / cm ^{2 using} the same plate setter as in Example 1 and then mounted on a Harris printer to print.
0 parts of a good printed matter without stain was obtained. Evidence of scattering due to ablation was scarcely observed in any of the plates by plate observation after exposure.

Example 19 Instead of the aluminum substrate of Example 1, a 0.2 mm polyethylene terephthalate film was used. In all other respects, a heat-sensitive planographic printing plate was obtained in the same manner as in Example 1. The original plate was exposed in the same manner as in Example 1, and then mounted on a Harris press and printed.
0 parts of a good printed matter without stain was obtained. Evidence of scattering due to ablation was scarcely observed in the plate surface after exposure.

Example 20 The following coating solution was applied to the aluminum substrate of Example 1 with a bar coater so as to be 24 ml / m ^2.
By heating and drying at 0 ° C for 1 minute, the dry coating amount is about 1g /
An aluminum substrate having an m ² ink receiving layer was obtained.

Coating solution for ink receiving layer: N- (4-hydroxyphenyl) methacrylamide / acrylonitrile / benzyl acrylate / methacrylic acid = 26/13/49/12 parts by weight of a copolymer (weight average molecular weight 75, 000) 3 g PF ₆ salt of condensate of 4-diazodiphenylamine and formaldehyde 0.3 g Leuco crystal violet 0.15 g Methanol 10 g Ethylene glycol monomethyl ether 17 g

Next, the entire surface of the substrate was exposed with a 3 KW UV lamp to effect three-dimensional crosslinking. This substrate was used in place of the aluminum substrate coated with the ink receiving layer of Example 1. In all other respects, a heat-sensitive planographic printing plate was obtained in the same manner as in Example 1. After exposing this printing plate in the same manner as in Example 1, the plate was attached to a Harris press and printed.
10,000 parts of a good printed matter free of stains were obtained.
Evidence of scattering due to ablation was scarcely observed in the plate surface after exposure.

Example 21 A coating solution having the following composition was applied on the substrate coated with the ink receiving layer of Example 1 so that the coating solution amount was 24 ml / m ² . After that, it was dried at 100 ° C. for 1 minute, and about 1 g /
A three-dimensionally crosslinked hydrophilic layer having a dry coating weight of m ² was obtained. Further, the overcoat layer of Example 1 was provided thereon to obtain a heat-sensitive lithographic printing original plate. The original plate was exposed in the same manner as in Example 1 and then mounted on a Harris press to print. As a result, 20,000 copies of a good printed matter free of stains were obtained. Evidence of scattering due to ablation was scarcely observed in the plate surface after exposure.

Composition of coating liquid for hydrophilic layer: 1 g of a 10% solution of 2-hydroxyethyl methacrylate homopolymer (weight average molecular weight: 250,000) in ethylene glycol monomethyl ether 1 g methanol silica (manufactured by Nissan Chemical: silica particles of 10 to 20 nm: 30) (A colloid consisting of a methanol solution containing 0.1% by weight) 3 g Aminopropyltriethoxysilane 0.05 g Cyanine dye (I-32) 0.13 g Methanol 16 g

Example 22 N- (p-aminosulfonylphenyl) methacrylamide / methyl methacrylate / acrylonitrile / 2-hydroxyethyl methacrylate = 40/10/30/20
3 g of the weight-% copolymer was dissolved in a mixed solvent consisting of 50 g of ethylene glycol monomethyl ether and 47 g of methyl ethyl ketone, and applied to the aluminum substrate used in Example 1 so as to have a concentration of 20 ml / m ² . After application, 100
° C., dried for 1 minute, and an aluminum substrate having an ink-receiving layer having a dry coating weight of about 0.6 g / m ^2.

Next, 18 g of tetraethoxysilane, 32 g of ethanol, 32 g of pure water and 0.02 g of nitric acid were placed in a beaker and stirred at room temperature for 1 hour to prepare a sol solution. 3 g of this sol solution, polyvinyl alcohol (trade name PVA11)
7: 4 g of a 10% aqueous solution of Kuraray Co., Ltd., 8 g of a 20% aqueous solution of colloidal silica (trade name: Snowtex C: manufactured by Nissan Chemical Co., Ltd.), and cyanine dye (I-31) 0.10
g, 8 g of pure water and 0.04 g of polyoxyethylene nonylphenyl ether, using a bar on an aluminum substrate coated with the above ink receiving layer, using a bar.
It was applied so as to be ml / m ² . After the coating, a hydrophilic layer having a dry coating weight of about 2 g / m ² was dried at 100 ° C. for 5 minutes. Next, the overcoat layer used in Example 3 was provided on the hydrophilic layer in the same manner as in Example 3 to obtain a heat-sensitive lithographic printing original plate. The original plate was mounted on a 40 W trend setter (a plate setter equipped with a 830 nm semiconductor laser of 40 W, manufactured by Creo Canada), and irradiated with energy of 600 mJ / cm ² . When the exposed printing plate was mounted on a Harris printing machine and printed, 40,000 copies of good printed matter without stain were obtained. Evidence of scattering due to ablation was hardly observed in the plate surface observation after exposure.

[0111]

According to the present invention, the disadvantages of the conventional heat mode plate making method using laser exposure can be solved. That is, by using the lithographic printing original plate of the present invention, scanning exposure can be performed in a short time, and further, it is possible to mount the lithographic printing plate directly on a printing machine and perform printing without performing development processing. Further, the obtained printing plate is excellent in printing durability and less stained in printing. Further, at the time of laser exposure, ablation (scattering) of the heat-sensitive layer is suppressed, and contamination of an exposure apparatus such as an optical system can be effectively avoided.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G03F 7/11 G03F 7/11 (72) Inventor Hidekazu Ohashi 4000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Fujifilm Shin Film Corporation F term (reference) 2H025 AA00 AA12 AB03 AC08 AD01 AD03 BH01 CB14 CB45 CC20 DA01 DA36 DA37 FA10 2H096 AA07 AA08 BA16 CA20 EA04 GA45 2H114 AA04 AA24 AA27 AA28 AA30 BA01 BA10 DA03 DA53 DA57 DA53 DA53 DA53 DA53 DA53 DA53 DA53 DA53 DA57 DA61 DA79 EA01 EA02 EA03 EA06

Claims (4)

[Claims] 1. A three-dimensionally cross-linked hydrophilic layer whose heating part is easily removed by a fountain solution or ink during printing, and a water-soluble material on a substrate having an ink-receiving surface or coated with an ink-receiving layer. A heat-sensitive lithographic printing plate precursor provided with an overcoat layer sequentially, wherein the heat-sensitive lithographic printing plate precursor contains a photothermal conversion agent in a crosslinked hydrophilic layer and / or ink-receiving layer. 2. The crosslinked hydrophilic layer is at least one selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metal oxides or hydroxides. 2. The heat-sensitive lithographic printing plate precursor according to claim 1, comprising a colloid of one compound. 3. The crosslinked hydrophilic layer is at least one selected from oxides or hydroxides of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. The heat-sensitive lithographic printing plate precursor according to claim 1, comprising a colloid of two compounds and a hydrophilic resin. 4. The heat-sensitive lithographic printing plate precursor according to claim 3, wherein the hydrophilic resin is a homo- or copolymer of hydroxyalkyl acrylate or hydroxyalkyl methacrylate.