JP2001047755A - Lithographic printing original plate, and lithographic printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a plate-making by a scanning exposure of a short period of time, and at the same time, improve the printing resistance and reduce printing blemish by making a layer comprising a hydrophilic medium, which is provided on a supporting body, contain a hydrophobic precursor, of which the surface is hydrophilic, and a light-heat converting agent, which itself, or at least the surface of which is hydrophilic. SOLUTION: In a layer comprising a hydrophilic medium, which is provided on a supporting body, a hydrophobic precursor, of which the surface is hydrophilic, and a light-heat converting agent, which itself, or at least the surface of which is hydrophilic, are contained. In this case, the layer comprising the hydrophilic medium is made to be sol-gel convertible. Also, the hydrophobic precursor, of which the surface is hydrophilic, encloses a hydrophobic substance in the core section, and also, is a particle dispersed substance of a composite constitution, having a surface layer section, of which the surface is hydrophobic. In addition, in the light-heat converting agent, the surface is a solid particle, which is selected from a hydrophilic metal, a metal compound, a pigment and a carbon simple substance, or a hydrophilic dye, which can be dissolved with the hydrophilic medium. In the meantime, a water-soluble protective layer may be provided on the surface of this lithographic printing original plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an original plate for direct thermal lithographic printing for offset printing which does not require development and has excellent printing durability. More specifically, the present invention relates to a lithographic printing plate precursor that can record an image by scanning exposure based on a digital signal and can be water-developed or can be mounted on a printing machine and printed without development.

[0002]

2. Description of the Related Art In general, a lithographic printing plate comprises an oleophilic image area receiving ink during a printing process and a hydrophilic non-image area receiving fountain solution. As such a lithographic printing plate precursor, a PS plate in which a lipophilic photosensitive resin layer is provided on a hydrophilic support has been widely used. The plate making method is usually a method of exposing through an image of a developed lithographic film or the like, and then dissolving and removing a non-image portion with a developing solution, whereby a desired printing plate is obtained.

[0003] The plate making process in the conventional PS plate involves a wet operation for dissolving and removing a non-image portion after exposure, and it is desired to eliminate or simplify this operation. In particular, in recent years, wastewater discharged from wet processing has not only improved economics, requiring wastewater treatment costs, but has also been improved in terms of the global environmental burden of industrial waste, which is a major concern of the entire industry. Requests are getting stronger.

[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, a major problem of the on-press development method is that the image recording layer is not fixed even after the printing original plate is exposed, for example, until the original plate is mounted on a printing machine, the original plate is stored in a completely light-shielded state or at a constant temperature. It was necessary to take such a troublesome method.

On the other hand, another trend in this field in recent years is that digitization techniques for electronically processing, storing, and outputting image information using a computer have become widespread. A variety of new image output methods that are compatible have been put to practical use. In particular, a computer-to-tool for manufacturing a printing plate directly without carrying a lithographic film by carrying digitized image information in high-convergent radiation such as laser light and scanning and exposing the original plate with this light. Plate technology is attracting attention. Accordingly, obtaining an original plate for a printing plate adapted to this purpose has become an important technical problem. Therefore, simplification, dryness, and no-processing of the plate making operation are more strongly desired than ever in view of both the above-mentioned environmental aspects and adaptation to digitalization.

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 applied to an exposure area during an instantaneous exposure time, and the light energy is efficiently converted to heat energy, and the heat causes chemical change, phase change,
A thermal change such as a change or destruction of the 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 in which the exposed image recording layer is imagewise removed to form a printing plate is performed by an on-press development method, development (non-image Part removal) allows a printing system in which the image is unaffected even if it is exposed to room ambient light for some time after image exposure. 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.

The use of microcapsule technology has been considered as one means of the heat mode system which has been advanced as a solution to the simplification of the plate making process.

JP-A-3-108588 and JP-A-5-108588
JP-A-8575 discloses a plate material in which a heat-sensitive recording layer comprising a microencapsulated heat-fusible substance and a binder resin is provided on a support, and a heating portion is changed to lipophilic. However, none of the microencapsulated hot-melt materials had reactivity with the medium, and therefore had high diffusivity and was not satisfactory in discriminability. On the other hand, JP-A Nos. 62-164596 and 62-164.
No. 049 discloses a lithographic printing plate precursor comprising a support having a hydrophilic surface and a recording layer containing a blocked isocyanate together with an active hydrogen-containing binder polymer, and a method therefor. However, this printing plate requires a developing step of removing a non-printed portion after printing.

Further, as one of the direct type lithographic printing materials, there is a direct drawing type lithographic printing material in which an image portion is formed on the surface of a hydrophilic layer by an external means such as ink jet or toner transfer. Attempts have been made to incorporate capsule technology. Japanese Patent Application Laid-Open No. Sho 62-1587 discloses a plate material in which a microencapsulated non-reactive heat-fusible substance is applied, and a toner receiving layer is formed by heating and printing. However, a printing plate is formed only when lipophilic toner or the like is fixed to the formed toner receiving layer, and an image portion is not formed after printing.

Japanese Patent Application Laid-Open No. Hei 7-1849 introduces a mechanism in which a lipophilic component in a capsule and a hydrophilic binder polymer are chemically bonded at the interface between the microcapsule and the binder, thereby suppressing swelling and improving printing durability. Although this is intended to meet the needs of the market, this printing plate uses a method in which the lipophilic substance reacts with the binder to form an ink receiving area after the thermal destruction of the capsule by the thermal head. Therefore, it is expected that the hydrophobic region is expanded due to the diffusion of the lipophilic substance, which is disadvantageous for high definition. As described above, conventional plate materials for heat-sensitive lithographic printing, even when microencapsulated, lack printing durability, discrimination, oleophilicity, etc. Was limited to use.

[0012] 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, exposed to heat in an image form, and the solubility of the hydrophobic layer is determined. A method has been proposed in which the dispersibility is changed and, if necessary, the non-image portion is removed by wet development. As an example of such an original plate, for example, JP-B-46-279
JP-A No. 19 discloses an original plate in which 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, is provided on a hydrophilic support. A method of obtaining a printing plate by recording in a heat mode is disclosed. However, since this recording layer has insufficient heat sensitivity, it has insufficient sensitivity to heat mode scanning exposure, and thus has poor discrimination between an image portion and a non-image portion.

[0013] Attempts have also been made to make the heat mode thermohydrophobic. For example, JP-A-53-64747 and JP-A-1-113290 disclose that a hot-melt resin and a thermoplastic resin dispersed in a heat-sensitive layer provided on a support are melted by thermal printing and heated. Plate material for changing a portion from hydrophilic to lipophilic is also disclosed in U.S. Pat. No. 4,034,183,
JP-A-4,063,949 and the like each disclose a plate material for irradiating a hydrophilic polymer provided on a support with a laser to remove the hydrophilic group and convert the hydrophilic polymer to lipophilic. However, these plate materials have a problem that the discrimination between the image portion and the non-image portion is low, for example, the non-image portion is stained by the hot-melt substance present on the plate surface receiving the ink.

On the other hand, EP 94/18005 discloses that
There is disclosed a lithographic printing plate precursor in which a hydrophilic crosslinked layer and a lipophilic light-to-heat conversion layer are supported on a support, and can be made in a similar manner without development. However, the prepress requires an operation of rubbing the crosslinked hydrophilic layer imagewise, which seems to be problematic in terms of simplicity.

[0015] WO 98/40212 discloses that
There is disclosed a lithographic printing plate precursor in which a hydrophilic layer containing a metal oxide colloid and an lipophilic image recording layer containing a photothermal conversion substance are provided on a substrate and can be made without development. However, at least the present inventor believes that when the light-to-heat conversion layer is lipophilic, there are many points to be solved in order to ensure the distinction between the image part and the non-image part.

WO 99/04974 discloses that a hydrophilic image recording layer containing a light-converting and ink-receptive light-absorbing substance such as a dye or pigment and a colloidal dispersion of metal or metal oxide is provided on a substrate. Discloses a lithographic printing original plate capable of making a plate without development. But,
Only specific examples of two light-absorbing cationic dyes and carbon black are disclosed as specific light-to-heat converting agents.

JP-A-6-199064 and WO98 /
Japanese Patent No. 40212 discloses a two-layered lithographic printing plate precursor using laser light recording in which a layer containing a photothermal conversion agent and a layer having a different hydrophilicity / hydrophobicity are used in combination. Suggests ways to further improve in the future.

Further, another problem of the conventional heat mode positive type original plate is a phenomenon called a residual film in a non-image portion. That is, the change in solubility due to exposure in the vicinity of the support in the recording layer is small compared to the vicinity of the surface of the recording layer, so that a defect that the film material in the vicinity of the support remains without being dissolved tends to occur. Point improvement was needed. In general, in a heat mode positive original plate, 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. Often small. For this reason, the degree of hydrophilization of the recording layer near the support is relatively low. As a result, the hydrophobic film is often not completely removed from the exposed portion where the hydrophilic surface is to be provided. Such a residual film in the non-image portion causes printing stains on printed matter. Conventionally, a multi-layer system in which a photothermal conversion layer and an image recording layer are often used is separated in function.

As shown in the background of the plate making and printing technique using the image recording in the heat mode, the characteristic advantage of this plate making and printing method is that a plate is directly made from under the plate without passing through a film. Therefore, it is possible to make a plate on the machine and to omit the development operation.However, on the other hand, the lack of heat mode sensitivity, the diffusion of the image substance due to heat, the surface and bottom of the image recording layer, It has weaknesses such as differences in sensitivity. These weaknesses are basically defects that cause insufficient discrimination between an image portion and a non-image portion, and are therefore directly related to print quality and printing durability. Therefore, it can be said that the basic measure for improving both the printing quality and the printing durability of the plate making / printing method using the image recording in the heat mode is to improve the discriminability. It can be expected that the above-mentioned defect in various other expressions will be solved by itself.

[0020]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned defects of a heat-mode plate making method using laser exposure or the like so that development processing is not performed after scanning exposure in a short time. It is an object of the present invention to provide a heat-mode type lithographic printing plate precursor that can be made into a plate, has excellent printing durability, and has less printing stains on a printing surface.
Further, from the viewpoint of specific means for improving both the printing durability and the prevention of printing stains, it is an object of the present invention to provide a heat-mode type lithographic printing plate precursor excellent in discrimination between an image portion and a non-image portion. .

[0021]

The key to solving the above problem is to find a new means for maximizing the change from hydrophilic to hydrophobic by image-like light irradiation. We continued our research, thinking that there was, and found a new principle of expressing discrimination ability, and based on that, completed the invention. That is, the present invention is as follows.

1. A layer made of a hydrophilic medium provided on the support, for lithographic printing, wherein the surface contains a hydrophobizing precursor having a hydrophilic property and a light-to-heat conversion agent having a hydrophilic property itself or at least a surface property. Original plate.

2. 2. The lithographic printing original plate as described in 1 above, wherein the layer made of a hydrophilic medium has a sol-gel conversion property.

3. The hydrophobizing precursor having a hydrophilic surface is a composite particle dispersion containing a hydrophobic substance in a core and having a surface layer having a hydrophilic surface, according to claim 1 or 2, The lithographic printing plate as described.

4. The light-to-heat conversion agent is a metal having a hydrophilic surface,
4. The lithographic printing original plate as described in any one of the above items 1 to 3, wherein the lithographic printing plate is a solid fine particle selected from a metal compound, a pigment, and simple carbon or a hydrophilic dye soluble in a hydrophilic medium.

[5] The lithographic printing original plate as described in any one of the above items 1 to 5, wherein a water-soluble protective layer is provided on the surface.

6. After irradiating the lithographic printing plate precursor according to any one of the above 1 to 5 with visible light or infrared light having photothermal conversion in an imagewise manner, the illuminated surface is brought into contact with ink to form a printing plate surface in which the image surface has received the ink. A lithographic printing method characterized by forming and printing.

The basis of the present invention is that in order to maximize the effect of discriminating the image area and the non-image area after plate making, it is essential that the surface of the original plate be sufficiently hydrophilic. This is the discovery of the principle that the difference between the hydrophobicity and the hydrophilicity of the non-irradiated portion increases, and the lack of the degree of hydrophilicity on the surface of the original plate cannot be compensated for by increasing the hydrophobicity of the irradiated region. Based on this principle, in the present invention, all of the components of the image recording layer provided on the support, that is, the medium of the image recording layer, the surface of the hydrophobizing precursor, the photothermal conversion agent itself or the particle form In this case, the basic configuration is such that all of the surfaces are hydrophilic. When imagewise light irradiation is performed on the image recording layer, the photothermal conversion agent generates heat, and the heat causes the hydrophobizing precursor to make its vicinity hydrophobic, and the hydrophobicity of the formed image area is reduced to that of the non-image area. Expresses remarkable distinction between hydrophilicity. This is the key to improving the ink repellency of the non-image area when printing plates are formed, preventing printing stains, and improving printing durability.

In the present invention, to meet this basic,
Each component of the image recording layer is made hydrophilic. First, with regard to the medium, a specific medium having high hydrophilicity is a sol-gel converting medium. A sol-gel converting medium that converts to a gel-like structure of a product,
This is one of preferred embodiments.

In order to further improve the degree of hydrophilicity of the image recording layer, highly hydrophilic silica, silicon hydroxide, aluminum hydroxide,
It is effective to contain a colloidal dispersion selected from aluminum oxide, titanium oxide and titanium hydroxide.

Next, the hydrophobizing precursor having a hydrophilic surface is (1) a composite particle dispersion having a hydrophobic substance in the core and a surface layer having a hydrophilic surface. Crosslinking reaction is started by the action of heat in the precursor, in which the hydrophobic substance contained by the action of irradiation and light-to-heat conversion makes the vicinity hydrophobic, and (2) a heat-crosslinkable particle dispersion having a hydrophilic surface. There is a precursor that develops hydrophobicity by being performed. As the preferred form of the former composite particle dispersion, a so-called hetero-aggregated particle containing a thermoplastic resin that softens or melts at the temperature of image exposure in a heat mode, and has a hydrophilic sol particle layer aggregated and adhered to the surface, Similarly, a hydrophilic polymerized layer having a hydrophilic surface layer such as a sol-gel conversion layer formed on its surface, and a hydrophobic polymer fine particle obtained by dispersion polymerization were used as a core to form a hydrophilic polymer layer around the core. Core-shell composite particles, emulsion particles in which a heat-diffusible or thermoplastic hydrophobic organic compound is emulsified and dispersed in a hydrophilic medium, and microcapsule particles in which a hydrophobic core substance is protected by a surface hydrophilic wall material Is mentioned. The details will be described in the embodiments and examples of the present invention.

The latter particle dispersion exhibiting hydrophobicity by initiation of thermal crosslinking includes a mixed dispersion of a polymerizable monomer and a crosslinking compound. In addition, any compound or compound group that has a function of making the vicinity of particles hydrophobic by the action of heat can be used as a hydrophobic precursor.

Specific hydrophobic compounds which can be included in the emulsified and dispersed particles or the microcapsule particles are liquid or solid organic compounds having a melting point of 300 ° C. or less and a boiling point of 100 ° C. or more at normal pressure. Low molecular weight compound and solubility in water at 25 ° C in 100g or 25 ° C
Is an organic polymer compound having a water absorption of 2 g or less per 100 g. The low-molecular organic compound has the above melting point and boiling point, and the solubility in 100 g of water at 25 ° C. is 2 g or less, or the organic / inorganic ratio in the organic conceptual diagram is 0.7 or more. Particularly preferred is at least one of the following.

On the other hand, the organic high molecular compound that can be included in these particles is preferably at least one of polyurethanes, polycarbonates, polyesters, polyacrylates, cellulose esters, and cellulose acetal.

Next, the photothermal conversion agent contained in the hydrophilic medium may be a photothermal conversion solid fine particle having a hydrophilic surface, or a photothermal conversion biodegradable hydrophilic particle capable of being dyed or dispersed in the medium. It is a dye. The solid fine particles are solid fine particles selected from a metal, a metal compound, a pigment, and carbon alone.

It is preferable to provide a water-soluble protective layer on the surface of the printing plate of the present invention in order to prevent contamination of the plate during handling of the plate, especially to prevent hydrophobicity. Next, the present invention summarized above will be described in more detail in embodiments.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The image recording layer will be described below in order. (Image recording layer) The image recording layer of the present invention is a hydrophilic layer provided on a support, and a surface-hydrophobizing precursor, a hydrophilic precursor itself or a hydrophilic surface. A light-to-heat conversion agent.

(Light-to-heat conversion agent) The light-to-heat conversion agent in the present invention refers to a substance having an absorbance of at least 0.3 × 10 ³ cm ⁻¹ , preferably 1 × 10 ³ cm ⁻¹ or more, more preferably 1 × 10 ³ cm ⁻¹ or more. Absorbed light refers to a substance that is not less than × 10 ⁴ cm ⁻¹ and that is not substantially converted into fluorescence or phosphorescence. The absorbance is a value obtained by dividing the transmission concentration by the thickness. When the molecule is substantially dispersed in a medium such as a dye, the light absorption coefficient of the medium is the above value. Needless to say, many substances absorb some light, and if they absorb light, the energy level of the excited substance will release heat unless it emits phosphorescence when returning to the ground level. Strictly speaking, it can be said that most substances have a light-to-heat conversion action even if slightly. Therefore, in the case of a light-to-heat conversion substance, it is appropriate to refer to a substance having light absorption characteristics of a size that can bring about a desired heat change, and the light-to-heat conversion agent in the present invention is used for the purpose. It means a substance having at least the above absorbance. The photothermal conversion agent satisfying the above requirements used in the present invention is a metal, a metal oxide, a metal nitride, a metal sulfide, a metal compound such as a metal carbide, a non-metal simple substance and a compound, a carbon simple substance, a pigment and a dye. Either one may be used.

<Solid Fine Particles with Light-to-Heat Conversion> The solid fine particles with light-to-heat conversion may be made of a hydrophobic substance, a hydrophilic substance, or an intermediate substance. Except for substances that are themselves hydrophilic, it is necessary to apply a surface hydrophilic treatment. Details of the surface hydrophilicity treatment include silicate treatment, aluminate treatment, provision of a water chemically adsorbed layer by steam treatment, provision of a protective colloid polymer surface layer, and surfactant treatment described later in specific examples. It is performed alone or in combination.

Preferred metal compounds of this type are oxides of transition metals, sulfides of metal elements of groups 2 to 8 of the periodic table and nitrides of metals of groups 3 to 8 of the periodic table. Transition metal oxides include iron, cobalt, chromium, manganese, nickel,
Oxides such as molybdenum, tellurium, niobium, yttrium, zirconium, bismuth, ruthenium, and vanadium are included. In addition, although there is a classification method that is not necessarily included in the transition metal, oxides of zinc, mercury, cadmium, silver, and copper can also be used in the present invention. Among these, Fe
O, Fe ₂ O ₃ , Fe ₃ O ₄ , CoO, Cr ₂ O ₃ , M
nO ₂ , ZrO ₂ , Bi ₂ O ₃ , CuO, CuO ₂ , A
gO, PbO, PbO ₂ , and VO _x (x = 1 to 5) are examples of particularly preferred metal oxides. VO _x includes black VO, V ₂ O ₃ , VO ₂ , and brown V ₂ O ₅
Is mentioned.

Preferred inorganic metal oxides include TiO.
_x(X = 1.0-2.0), SiO _x(X = 0.6-
2.0), AlO_x(X = 1.0-2.0)
Can be. TiO_x(X = 1.0-2.0)
Color TiO, black purple Ti_TwoO _ThreeDue to crystal form and contaminants
TiO that exhibits various colors from colorless to black_TwoKind
is there. SiO_x(X = 0.6-2.0) is SiO,
Si_ThreeO_TwoPurple, blue, red depending on colorless or coexisting substance
SiO showing colors such as_TwoIs mentioned. Also, AlO_x
(X = 1.5)
Corundum that shows colors such as red, blue, and green
You.

When the metal oxide is a lower oxide of a polyvalent metal, it may be a photothermal conversion agent and a self-heating type air oxidation reactant. In that case, heat energy generated as a result of the self-exothermic reaction can be used in addition to the energy absorbed by light, which is preferable. The lower oxides of these polyvalent metals include lower oxides such as Fe, Co, and Ni. Specifically, ferrous oxide, triiron tetroxide, titanium monoxide, stannous oxide, chromous oxide and the like can be mentioned. Among them, ferrous oxide, ferric oxide and titanium monoxide are preferable.

Whether or not the self-exothermic reaction occurs can be easily confirmed by a differential thermobalance (TG / DTA). When the self-heating substance was inserted into the differential thermobalance and the temperature was increased at a constant rate, an exothermic peak appeared at a certain temperature, and it was observed that an exothermic reaction occurred. When an oxidation reaction of a metal or a lower metal oxide is used as a self-heating reaction, an exothermic peak appears and an increase in weight is also observed on a thermobalance. Again, by using self-heating energy in addition to the light-heat conversion mechanism,
More heat energy can be used in a sustained manner, thereby improving sensitivity.

When the light-to-heat converting fine particles are made of a metal sulfide, a preferred metal sulfide is a heavy metal sulfide such as a transition metal. Among them, preferred sulfides include sulfides of iron, cobalt, chromium, manganese, nickel, molybdenum, tellurium, strontium, tin, copper, silver, lead and cadmium, among which silver sulfide, ferrous sulfide and cobalt sulfide Is preferred.

When the photothermal conversion fine particles are made of a metal nitride, the preferred metal nitride is a metal azide compound. Particularly, azides of copper, silver and tin are preferred. These azide compounds are also self-heating compounds that generate heat by photolysis. Other preferred inorganic metal nitrides include TiN _x (x = 1.0-2.0), SiN _x (x
= 1.0-2.0), AlN _x (x = 1.0-2.0)
And the like. As the TiN _x (x = 1.0 to 2.0), bronze TiN or brown TiN _x (x = 1.
3). Examples of SiN _x (x = 1.0 to 2.0) include Si ₂ N ₃ , SiN, and Si ₃ N ₄ . AlN _x (x = 1.0 to 2.0) has AlN
And the like.

Each of the above metal oxides, sulfides and nitrides can be obtained by a known production method. Also,
Many are commercially available under names such as titanium black, iron black, molybdenum red, emerald green, cadmium red, cobalt blue, navy blue, and ultramarine.

The particle size of these hydrophilic metal compounds varies depending on the refractive index and the extinction coefficient of the substance constituting the particles, but is generally 0.005 to 5 μm, preferably 0.01 to 3 μm. is there. When the particle size is too small, light scattering is caused, and when the particle size is too large, light absorption becomes inefficient due to reflection at the particle interface.

<Light-to-heat converting metal fine particles> Next, light-to-heat converting metal fine particles will be described. Many of the metal particles are
It is photothermal and self-heating. Further, a surface hydrophilic treatment is required as in the case of a metal compound which is not hydrophilic itself.

As the metal fine particles, Mg, Al, Si,
Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Z
n, Ga, Ge, Y, Zr, Nb, Mo, Tc, Ru,
Pd, Ag, Cd, In, Sn, Sb, Hf, Ta,
Fine particles such as W, Re, Os, Ir, Pt, Au, and Pb are included. These metal fine particles are self-heating as well as light-to-heat converting. Among these, those which easily cause an exothermic reaction such as an oxidation reaction by thermal energy obtained by photothermal conversion of absorbed light are preferable.
1, Si, Ti, V, Cr, Mn, Fe, Co, Ni,
Cu, Zn, Y, Zr, Mo, Ag, In, Sn, and W are preferable. Among them, those having high absorbance of radiation and large heat energy of self-heating reaction include Fe and C.
o, Ni, Cr, Ti and Zr are preferred.

These metals may be composed of not only single particles but also alloys of two or more components.
Particles composed of a metal and the above-described metal oxides, nitrides, sulfides, carbides and the like may be used. The metal itself has a higher self-heating reaction heat energy such as oxidation, but its handling in the air is complicated, and there is a danger of spontaneous ignition when exposed to air. Such a metal powder is preferably covered with a metal oxide, nitride, sulfide, carbide, or the like with a thickness of several nm from the surface. The size of these particles is 10μ
m, preferably 0.005 to 5 μm, more preferably 0.01 to 3 μm. If it is less than 0.01 μm, it is difficult to disperse the particles, and if it is more than 10 μm, the resolution of the printed matter deteriorates.

The above-mentioned solid fine particles, such as inorganic metal oxides and inorganic metal nitrides, simple metals and alloys, and light-absorbing simple substances, which are weakly hydrophilic or hydrophobic, are subjected to a hydrophilic treatment on the surface thereof. The effects of the invention are exhibited. As a means for making the surface hydrophilic, a known means for making the surface hydrophilic can be used. For example, a method of adding a surfactant having hydrophilicity and adsorptivity to particles to form a surface-adsorbing layer of hydrophilic groups on the surface of the particles and dispersing the particles, gelatin, casein, polyvinyl alcohol, polyvinylpyrrolidone A method of providing a protective and colloidal hydrophilic and surface-adsorbing polymer film, a dispersion method of interposing a surfactant on the particle surface to make the particle surface more hydrophilic and stable, and a hydrophilicity that reacts with the constituent materials of the particle. For example, surface treatment with a substance having a functional group or the like can be used.

Particularly preferred is a surface silicate treatment. For example, in the case of iron fine particles or iron trioxide fine particles, the surface is sufficiently immersed in a 70 ° C. aqueous solution of sodium silicate (3%) for 30 seconds. It can be made hydrophilic. Among these, metal oxide fine particles having a hydrophilic surface, particularly metal oxide fine particles having a silicate surface, particularly iron oxide or iron fine particles having a silicate surface, are preferred embodiments of the effects of the present invention. is there.

When a surfactant is used for dispersion, an appropriate surfactant is selected according to the type of the particles to be dispersed and the medium of the image recording layer. To disperse the particles in such a hydrophilic medium in a surface hydrophilic state, sorbitan tristearate, sorbitan monopalmitate,
Nonionic surfactants such as sorbitan triolate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether, alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazo Linium betaine or N-tetradecyl-N, N
Amphoteric surfactants such as betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.), dodecylbenzenesulfonic acid and other alkylbenzenesulfonic acids having 8 to 22 carbon atoms, alkylnaphthalenesulfonic acids (alkyl groups) Is 1 or 2 and the sum of carbon numbers is 1 to 6), naphthalenesulfonic acid, or a formalin condensate thereof (condensation number is 2 to 5), or an anionic interface such as alkyl sulfuric acid having 8 to 22 carbon atoms. An activator can be used.

<Non-metallic simple substance having photothermal conversion>
In addition to the above metal compounds and metals, non-metallic simple substances and non-metallic light-heat converting fine particles are also used. These light-heat converting fine particles include simple organic particles such as carbon black, graphite (graphite) and bone charcoal (bone black), as well as various organic and inorganic pigments. Many of these are themselves hydrophobic, and their surfaces need to be subjected to a hydrophilic treatment.

For making the surface hydrophilic, any conventionally known method can be used. For example, the surface of the carbon black particles can be made hydrophilic by performing a hydroxyl group introduction treatment or a silicate treatment by a known method. For example, 10 g of carbon black particles are placed in a reaction vessel under reduced pressure, degassed, and then subjected to plasma irradiation while flowing steam to obtain hydroxyl group-introduced carbon black. Furthermore, when the obtained hydroxyl group-introduced carbon black is dispersed in water, tetraethoxysilane is added dropwise and reacted at room temperature to obtain a surface silicate-treated carbon black.

<Photothermally Convertible Pigment> The present invention relates to fine particles which have a hydrophilic surface or a coating layer of a hydrophilic surface and which are photothermally convertible to irradiation light for image formation. Any dispersible pigment can be used. The pigment is
Any of a metal complex pigment and a non-metallic pigment may be used.

A preferred pigment is cobalt green (C.I.
I. 77335), emerald green (CI.77)
410), Phthalocyanine Bull- (CI. 7410)
0), copper phthalocyanine (CI. 74160), ultramarine (CI. 77007), navy blue (CI. 7)
7510), cobalt violet (CI. 77360), paliogen red 310 (CI. 71155), permanent red BL (CI. 71137), perylene red (CI. 71140), rhodamine lake B (C. .
I. 45170: 2), Helio Bordeaux BL (CI.
14830), Light Fast Red Toner R
(CI. 12455), First Scarlet V
D, Resol first scarlet G (CI.12)
315), permanent brown FG (CI.124)
80), Indanthrene Brilliant Orange RK
(CI. 59300), red-mouthed graphite (CI. 7760)
1), Hansa Yellow 10G (CI. 11710),
Titanium yellow (C.I.77738), zinc yellow (C.I.
I. 77955), chrome yellow (CI 7760)
0) and various pigments used in electrostatic recording toners can also be preferably used.

Regarding the pigment, it is necessary to perform the same surface hydrophilicity treatment as described above for the case of a metal compound, metal and carbon simple particles that are not themselves hydrophilic, except that the pigment itself is hydrophilic. .

In the image forming layer, the content of the light-heat converting fine particles is 1 to 95% by weight of the solid constituents.
Preferably, it is 3 to 90% by weight, more preferably 5 to 8%.
0% by weight. If the amount is less than 1% by weight, the calorific value is insufficient and 9
When the content is 5% by weight or more, the film strength decreases.

<Heat-Converting Hydrophilic Dye> As the light-to-heat converting agent, a hydrophilic dye having a light absorption region in a spectral wavelength region of irradiation light and being dyeable or dispersible in a hydrophilic medium is used. Can also be used. Preferred dyes are IR absorbers, specifically, dyes having a water-soluble group in the molecule, and include a polymethine dye, a cyanine dye, a squarylium dye, a pyrylium dye, a diimmonium dye, a phthalocyanine compound, a triarylmethane dye, It is a dye selected from metal dithiolenes. Of these, polymethine dyes, cyanine dyes, squarylium dyes, pyrylium dyes, diimmonium dyes, and phthalocyanine compounds are more preferable. Among them, polymethine dyes, cyanine dyes, and phthalocyanine compounds are most preferable from the viewpoint of synthesis suitability. Preferred water-soluble groups are a sulfonic acid group, a carboxyl group and a phosphonic acid group. Specific examples of the IR absorber used in the present invention are shown below, but the present invention is not limited to these.

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In the present invention, the content of these infrared absorbers is at least 6% by weight based on the total solid content of the photosensitive layer.
Preferably at least 10% by weight, particularly preferably 15% by weight
Used above. When the content of the infrared absorbent is less than 6% by weight, the sensitivity is lowered.

In order to exhibit the effect of the present invention, in addition to the photothermal conversion agent having the above-mentioned absorbance, the photothermal conversion effect is effectively exerted in the image recording layer containing the photothermal conversion agent. It must have the required level of light absorption or particle density to occur. The necessary light absorption capability is to have a spectral absorption region having an absorbance of 0.3 or more in a spectral wavelength region of 300 to 1200 nm where photothermal conversion is possible. Absorbance has an absorption maximum of 0.3 or more in a wavelength range (in the case of single wavelength light, a wavelength range of 100 nm width centered on the wavelength), or absorbance does not have an absorption maximum in this wavelength range. Means that there is a continuous spectral wavelength range of 100 nm or more with 0.3 or more. If the condition of the light absorption ability is satisfied, the sensitivity is increased by performing imagewise exposure at a wavelength corresponding to the absorption wavelength range, and the discrimination property is improved.

The transmission density of the image forming layer is determined according to international standards.
0.3 when measured according to ISO5-3 and ISO5-4
It is preferably from 3.0 to 3.0. When the transmission density exceeds 3.0, the radiation intensity is significantly reduced at the bottom of the image layer as a result of radiation attenuation, and the change to hydrophobicity hardly occurs. When the transmission density is 0.3 or less,
The absorption of radiation energy is not sufficient, and the amount of heat energy obtained by light-to-heat conversion tends to be insufficient.

(Hydrophobicizing Precursor) The description of the photothermal converting fine particles is completed above, and then the hydrophobizing precursor having a hydrophilic surface is described. In the present invention, a known substance whose polarity is changed to hydrophobic by various kinds of heat can be surface-hydrophilized and used as a hydrophobizing precursor. Preferred embodiments of the hydrophobizing precursor are shown in the following sections (1) and (2), but the present invention is not limited to these examples. (1) A particle dispersion having a composite structure in which a core contains a hydrophobic substance and has a surface layer having a hydrophilic surface. Precursors that have been hydrophobized by the existing hydrophobic substance. (2) A precursor which is a heat-crosslinkable particle dispersion having a surface hydrophilicity and which exhibits hydrophobicity when a cross-linking reaction is initiated by the action of heat. These will be further described below.

(1) A composite particle dispersion in which a core contains a hydrophobic substance and has a surface layer having a hydrophilic surface. The preferred particle form of the composite particle dispersion of the former (1) includes a thermoplastic resin that softens or melts at a temperature caused by heat mode image exposure, and causes a hydrophilic sol particle layer to coagulate and adhere to the surface. Composite particles of a so-called hetero-aggregated surface layer (hereinafter also referred to as hetero-aggregated surface layer particles), and surface hetero-phase composite particles of a surface treated with a sol-gel conversion material to form a hydrophilic gel surface layer by sol-gel conversion ( Core-shell type composite particles (hereinafter referred to as core-shell type particles) in which hydrophobic fine particles of a thermoplastic polymer obtained by dispersion polymerization are formed as a core and a polymer layer of a hydrophilic polymer is formed around the core. ), Emulsion particles obtained by emulsifying and dispersing a heat-diffusible or thermoplastic hydrophobic organic compound in a hydrophilic medium (hereinafter also referred to as hydrophobic organic substance-containing particles). ), And microcapsule particles in which a hydrophobic core substance is protected by a surface hydrophilic wall material (hereinafter also simply referred to as microcapsule particles). The latter (2) particle dispersion exhibiting hydrophobicity by the initiation of thermal crosslinking includes a mixed dispersion of a polymerizable monomer, a crosslinking compound and a thermal polymerization initiator.

<Hetero-aggregated surface layer particles> The former (1) hetero-aggregated surface layer particles are obtained by heat-softening or heat-melting obtained by emulsifying, dispersing and polymerizing a monomer protected by a surfactant micelle. Emulsion polymer dispersion particles of the conductive resin are included,
The resin particles are softened or melted by the effect of heat due to light irradiation and photothermal conversion, breaking the hydrophilic surface layer and rendering the vicinity existing as particles hydrophobic. The hydrophilic surface layer is a protective layer formed by adding a very hydrophilic sol-like fine particle dispersion such as silica fine particles and alumina fine particles and adsorbing the dispersion around the emulsion polymerization dispersion particles of the resin. The sol-like fine particle dispersion is the same as the sol-like fine particles described below as a component to be added to the medium of the hydrophilic image recording layer.

<Surface Heterophase Particles> The heterosurface phase particles mentioned as the former (1) are the same as those described above and are used as particles of emulsion-polymerized dispersion of heat-softening or heat-meltable resin and core particles, and the surface thereof is These are particles having a hydrophilic surface, which have been treated with a sol-gel converting substance described in the section of the medium of the hydrophilic image recording layer to form a gel phase on the particle surface.

<Core-Shell Type Particles> The core-shell type composite particles are prepared by preparing a particle dispersion of a resin (hereinafter also referred to as a thermoplastic resin) which softens or melts under the action of heat by emulsion polymerization of its monomer. Are core particle (seed), a hydrophilic monomer is added to the dispersion, and the surface of the core particle is polymerized with the hydrophilic monomer to form a surface hydrophilic layer. The monomer constituting the core particles is selected from those for hydrophobic and thermoplastic resins in the group of A to L shown as the monomer components for the polymer compound described in the following section. Similarly, the monomers forming the hydrophilic shell phase can be selected from the hydrophilic monomers from the group A to L.

<Particles Encapsulating Hydrophobic Organic Matter> The particles encapsulating hydrophobic organic matter described above are in the form of particles having a hydrophilic surface in which the encapsulated hydrophobic substance is emulsified and dispersed. The emulsified particles cannot maintain the particle shape due to the action of heat due to heat mode light irradiation, and the vicinity of the precursor is made hydrophobic by leaching, diffusing, dissolving, etc. into the medium. Among hydrophobic organic low molecular weight compounds and organic high molecular weight compounds, there are compounds suitable for this purpose.

Organic Low-Molecular Compound When the hydrophobic precursor contains an organic low-molecular compound, a preferable organic low-molecular compound has a melting point of 300 at normal pressure.
° C or less, the solubility or water absorption of a solid or liquid organic compound having a boiling point of 100 ° C or more or water is 2 per 100 g.
It is also a preferred embodiment to use an organic polymer compound of not more than g and using both of them. Since organic low molecular weight compounds have relatively high diffusion permeability, when mobility is given by heat, they are diffused in the vicinity of the presence of particles to make them hydrophobic directly or indirectly. Also included are compounds that are solid at room temperature and melt by heat to form a hydrophobic region. If the mobility is too large, the hydrophobic region is too wide, and the local concentration of heat energy is reduced, thereby reducing the effect of hydrophobicity. Therefore, a compound satisfying the above conditions of the boiling point and the melting point is preferable. Here, the term "low molecular weight compound" is used to mean a compound having a boiling point or a melting point, and such a compound usually has a molecular weight of 2000 or less, and often 1000 or less.

The conditions for the solubility or water absorption are as follows:
These conditions are empirically found as an index that the organic polymer compound is hydrophobic. Under this condition, hydrophobicity in the vicinity of the particles can be expressed by a change in the state of the organic polymer in the vicinity where the particles were present due to the action of heat.

Suitable low molecular weight organic compounds suitable for the purpose of hydrophobization are, in addition to the viewpoints of the melting point and boiling point related to the mobility of the above-mentioned compounds, to make the vicinity of the precursor sufficiently hydrophobic by itself. It is necessary to have a very low solubility in water or a high degree of organicity. The conditions are concretely shown as described above. As described above, the solubility of the low-molecular organic compound in 100 g of water at 25 ° C. is 2 g or less, or the organic / inorganic ratio in the organic conceptual diagram is 0%. .7 or more.

The organic conceptual diagram is a practical and simple practical scale for indicating the degree of organicity and inorganicity of a compound. For details, see “Organic conceptual diagram” by Yoshio Tanaka (Sankyo Shuppansha, 1983). The first edition of this year) is described in detail on pages 1-31. The reason why the organic compounds in the above range on the organic conceptual diagram have an action of promoting hydrophobicity is unknown, but the compounds in this range are compounds having relatively large organicity, and the vicinity of the composite particles is hydrophobic. To 1 in the organic conceptual diagram
The upper limit is not particularly limited to 00 or more, but is usually 100 to 1200, preferably 100 to 800, and the organic / inorganic ratio is 0.7 to infinity (that is, the inorganic property is 0), preferably Is an organic compound falling within the range of 0.9 to 10.

The organic low molecular weight compounds having a boiling point in this temperature range are, for example, aliphatic and aromatic hydrocarbons, aliphatic and aromatic carboxylic acids, aliphatic and aromatic alcohols, aliphatic and aromatic esters, Aliphatic and aromatic ethers,
It is found in organic amines, organic silicon compounds, and various solvents and plasticizers which are not so effective but can be added to printing inks.

Preferred aliphatic hydrocarbons are those having 8 to 3 carbon atoms.
0, more preferably an aliphatic hydrocarbon having 8 to 20 carbon atoms, and a preferred aromatic hydrocarbon is 6 to 40 carbon atoms.
And more preferably an aromatic hydrocarbon having 6 to 20 carbon atoms. Preferred aliphatic alcohols have 2 to 30 carbon atoms.
Are more preferably aliphatic alcohols having 2 to 18 carbon atoms, and preferred aromatic alcohols are those having 6 to 30 carbon atoms.
And more preferably an aromatic alcohol having 6 to 18 carbon atoms. Preferred aliphatic carboxylic acids have 2 to 24 carbon atoms.
Aliphatic carboxylic acid, more preferably having 2 to 2 carbon atoms
Preferred are aliphatic monocarboxylic acids having 20 and aliphatic polycarboxylic acids having 4 to 12 carbon atoms, and preferred aromatic carboxylic acids are those having 6 to 30 carbon atoms, and more preferably having 6 to 30 carbon atoms.
18 aromatic carboxylic acids. Preferred aliphatic esters have 2 to 30 carbon atoms, more preferably 2 to 1 carbon atoms.
And preferred aromatic esters are those having 8 to 30 carbon atoms, more preferably 8 to 18 carbon atoms.
Is an aromatic carboxylate. Preferred aliphatic ethers are those having 8 to 36 carbon atoms, more preferably 8 carbon atoms.
To 18 aromatic ethers, and preferred aromatic ethers are those having 7 to 30 carbon atoms, more preferably 7 to 1 carbon atoms.
8 aromatic ethers. In addition, carbon number 7-30
And more preferably an aliphatic or aromatic amide having 7 to 18 carbon atoms.

As specific examples, 2,2,4-trimethylpentane (isooctane), n-nonane, n-decane,
Aliphatic hydrocarbons such as n-hexadecane, octadecane, eicosane, methylheptane, 2,2-dimethylhexane and 2-methyloctane; aromatic hydrocarbons such as benzene, toluene, xylene, cumene, naphthalene, anthracene and styrene; dodecyl Monohydric alcohols such as alcohol, octyl alcohol, n-octadecyl alcohol, 2-octanol and lauryl alcohol; polyhydric alcohols such as propylene glycol, triethylene glycol, tetraethylene glycol, glycerin, hexylene glycol, dipropylene glycol; benzyl alcohol , 4-hydroxytoluene, phenethyl alcohol, 1-naphthol, 2-naphthol, catechol, aromatic alcohols such as phenol; acetic acid, propionic acid, butyric acid, Prong acid, acrylic acid, crotonic acid, capric acid, stearic acid, aliphatic monocarboxylic acids such as oleic acid; oxalic acid, succinic acid, adipic acid, maleic acid, polyvalent aliphatic carboxylic acids such as glutaric acid;
Aromatic carboxylic acids such as benzoic acid, 2-methylbenzoic acid and 4-methylbenzoic acid; ethyl acetate, isobutyl acetate,
Aliphatic esters such as n-butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl acrylate, dimethyl oxalate, dimethyl succinate and methyl crotonate; and methyl benzoate and methyl 2-methylbenzoate Aromatic carboxylic esters; organic amines such as imidazole, triethanolamine, diethanolamine, cyclohexylamine, hexamethylenetetramine, triethylenetetramine, aniline, octylamine, aniline, and phenethylamine; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and benzophenone , Methoxybenzene, ethoxybenzene,
Examples include ethers such as methoxytoluene, lauryl methyl ether, and stearyl methyl ether, and amides such as stearyl amide, benzoyl amide, and acetamide. In addition, organic solvents such as ethylene glycol monoethyl ether, cyclohexanone, butyl cellosolve, and cellosolve acetate having a boiling point within the above preferred range can also be used.

Also, oils and fats such as linseed oil, soybean oil, poppy oil, and safflower oil, which are components of the printing ink, tributyl phosphate, tricresyl phosphate, dibutyl phthalate,
Plasticizers such as butyl laurate, dioctyl phthalate, and paraffin wax are also included.

Further, an ester of a long-chain fatty acid and a long-chain monohydric alcohol, ie, a wax, is also hydrophobic, has a suitably low melting point, and is melted by heat generated by light irradiation in the vicinity of light-heat converting fine particles. It is a preferred low molecular weight organic compound that renders the region hydrophobic. Wax is 50-20
It is preferable to melt at 0 ° C., and examples thereof include carnauba wax, caster wax,
Microcrystalline wax, paraffin wax,
Any of so-called shell wax, palm wax, beeswax and the like can be used. In addition to waxes, low molecular weight polyethylene; solid acids such as oleic acid, stearic acid, and palmitic acid; and fine particle dispersions of metal salts of long chain fatty acids such as silver behenate, calcium stearate, and magnesium palmitate can also be used. it can.

Organic Polymer Compound A preferable organic polymer compound satisfying the above-mentioned conditions of solubility or water absorption is a hydrophobic polymer compound which is soluble in coexisting low molecular organic compounds or is thermoplastic itself,
For example, polyvinyl chloride, polyvinyl acetate, polyvinyl phenol, polyvinyl halogenated phenol,
Polyvinyl formal, Polyvinyl acetal, Polyvinyl butyral, Polyamide, Polyurethane, Polyurea, Polyimide, Polycarbonate, Epoxy resin, Phenol, Volak, or Condensation resin of resole phenols with aldehyde or ketone, Polyvinylidene chloride,
Examples include polystyrene and acrylic copolymer resins.

One of the preferred compounds is a phenol novolak resin or a resole resin which is not necessarily thermoplastic but which passes through organic low molecular weight compounds, such as 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, octylphenol, resorcinol, pyrogallol, catechol, chlorophenol (m-Cl, p-Cl), bromophenol (M-Br, p-Br), salicylic acid,
Novolak resins and resole resins for condensation with formaldehyde such as phloroglucinol, and condensation resins of the above-mentioned phenolic compounds and acetone are also included.

As other suitable high molecular compounds, copolymers having a molecular weight of usually 10,000 to 200,000, which includes the following monomers (A) to (L) as structural units, can be mentioned. (A) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, such as N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide ,
o-, m- and p-hydroxystyrene, o-, m-
And p-hydroxyphenyl acrylate or methacrylate, (B) acrylates and methacrylates having an aliphatic hydroxyl group, for example, 2-
Hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, (C) methyl acrylate, ethyl acrylate, 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-dimethylaminoethyl acrylate, etc. Substitution) acrylic ester, (D) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, benzyl methacrylate 2-chloroethyl acid, methacrylic acid 4
-Hydroxybutyl, glycidyl methacrylate, N-
(Substituted) methacrylates such as dimethylaminoethyl methacrylate,

(E) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N-hexylacrylamide, N
-Hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide, N
-Hydroxyethylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N
Acrylamides such as -phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenylmethacrylamide, N-ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide Or methacrylamide,

(F) 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; (G) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate; (H) styrenes such as styrene, methyl styrene and chloromethyl styrene; I)
Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone; (J) olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene;

(K) (L) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) such as N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile and methacrylonitrile ) 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-aminosulfonylphenyl) methacrylamide , N- [1- (3-
Aminosulfonyl) naphthyl] methacrylamide, N-
Methacrylamides such as (2-aminosulfonylethyl) methacrylamide, o-aminosulfonylphenyl acrylate, m-aminosulfonylphenyl acrylate, p-aminosulfonylphenyl acrylate, 1- (3-aminosulfonylphenylnaphthyl) acrylate and the like Unsaturated sulfonamides such as acrylates, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate, 1
Unsaturated sulfonamides such as methacrylic esters such as-(3-aminosulfonylphenylnaphthyl) methacrylate;

These organic polymer compounds have a weight average molecular weight of 500 to 20,000 and a number average molecular weight of 200 to 60.
000 is preferred.

The hydrophobizing precursor may be composed of only an organic low-molecular compound or a high-molecular organic compound, but may contain both an organic low-molecular compound and a high-molecular organic compound. It may contain a third component for the purpose of enhancing the affinity between the two.

In order to make the surface of the hydrophobizing precursor hydrophilic, the method described above for the photothermal conversion agent may be used as the surface hydrophilicity. For example, a method of adding a surfactant which is hydrophilic and has an adsorptivity to a hydrophobizing precursor to form a surface adsorption layer of a hydrophilic group on the particle surface to disperse the particles, in which case, gelatin, polyvinyl alcohol A method of providing a protective and colloidal hydrophilic and surface-adsorbing polymer film such as polyvinylpyrrolidone, a dispersion method of further stabilizing the particle surface by interposing a surfactant therein, For example, surface treatment with a substance having a hydrophilic group that reacts can be used. As the surfactant used for hydrophilizing the surface of the hydrophobizing precursor, the surfactant described for the surface hydrophilization of the photothermal conversion agent can be used.

The total amount of the hydrophobic constituents (core substances) in the surface hydrophilic hydrophobizing precursors described above is 10 to 95% by weight based on the total amount of the hydrophobizing precursors. It is suitable, and preferably 20 to 80% by weight. In the case where a low-molecular organic compound and a high-molecular organic compound are used together, the ratio is arbitrary. On the other hand, the components forming the hydrophilic surface layer are different from surfactants, protective colloids, hydrophilic polymer resins, hydrophilic sols, sol-gel conversion components, etc. depending on the form of, but are also distributed in the medium of the image recording layer. In some cases, the amount constituting the surface layer of the hydrophobic precursor is 5 to 80 with respect to the total amount of the hydrophobic precursor.
% By weight, and preferably from 10 to 50% by weight. In addition, the size of the dispersion particles varies in the range of the optimal size depending on the form of, but is approximately 5 μm in volume average.
Hereinafter, it is preferably 0.01 μm or more, more preferably 0.05 to 2 μm, and particularly preferably 0.2 to 0.5 μm.
It is preferable to adjust to the range of m.

<Microcapsule Particles> Next, as a term of the composite particle dispersion having a hydrophobic substance in the core and having a surface layer having a hydrophilic surface, the heat of the capsules is determined using the constituent material of the microcapsules described above. The hydrophobizing precursor that makes the vicinity hydrophobic by breaking will be described. The microcapsules used in the present invention can be prepared by various known methods, and the core substance (the substance contained in the capsule) is the above-mentioned organic low-molecular compound and high-molecular organic compound, and an organic solvent that mixes them. Can be used. That is, it can be prepared by mixing the core substance with an organic solvent or directly emulsifying and dispersing it in an aqueous medium to form a wall film composed of a polymer substance around oily droplets. As another category of core material, there may be mentioned a polymerizable monomer and / or a crosslinkable compound which forms a hydrophobic polymer, particularly a crosslinked structure in the vicinity of particles by heat, and this core material was used. Since the hydrophobic precursor particles can also be classified into the following hydrophobic precursor particles of the item (2), the details of the core material composed of the polymerizable monomer and / or the crosslinkable compound will be described in the next section. Specific examples of the polymer substance serving as the wall film of the microcapsules include, for example, polyurethane resin, polyurea resin, polyamide resin, polyester resin, polycarbonate resin, aminoaldehyde resin, melamine resin, polystyrene resin, styrene-acrylate copolymer resin, Styrene-methacrylate copolymer resin, gelatin, polyvinyl alcohol, and the like. Among these, a particularly preferred wall film is a microcapsule having a wall film made of a polyurethane / polyurea resin.

Microcapsules having a polyurethane / polyurea resin wall film are prepared by mixing a wall material such as polyvalent isocyanate into a core material to be encapsulated, and dissolving a protective colloid material such as polyvinyl alcohol in an aqueous medium. It is manufactured by emulsifying and dispersing, raising the liquid temperature and causing a polymer forming reaction at the oil droplet interface.

Here, specific examples of the polyvalent isocyanate compound are shown below. For example, m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4 -Diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-
Diphenylmethane-4,4'-diisocyanate, xylene-1,4-diisocyanate, 4,4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, Diisocyanates such as cyclohexylene-1,2-diisocyanate and cyclohexylene-1,4-diisocyanate; 4,4 ', 4 "-triphenylmethane triisocyanate; toluene-2,4,6-
Triisocyanates such as triisocyanate, 4,
4'-dimethyldiphenylmethane-2,2 ', 5,5'
-Tetraisocyanates such as tetraisocyanate,
Adduct of hexamethylene diisocyanate with methylethylolpropane, adduct of 2,4-tolylenediisocyanate with tremethylolpropane, adduct of xylylenediisocyanate with trimethylolpropane, adduct of tolylenediisocyanate with hexanetriol But is not limited to the above compounds. Also, two or more kinds can be used in combination as needed. Of these, particularly preferred are those having three or more isocyanate groups in the molecule.

As the capsule wall material, the above-mentioned gelatin, polyurea, polyurethane, polyimide, polyester, polycarbonate, melamine and the like can be used, but polyurea and polyurethane walls are preferable for obtaining thermoresponsive microcapsules. Further, in order to impart thermal responsiveness to the capsule wall, the glass transition point of the capsule wall may be from room temperature to 200 ° C., and particularly from 70 ° C. to 1 ° C.
A range of 50 ° C. is preferred.

The glass transition temperature of the capsule wall can be controlled by selecting a polymer type of the capsule wall or adding an appropriate plasticizer. Such auxiliaries include:
Phenolic compounds, alcohol compounds, amide compounds,
There are sulfonamide compounds and the like, which may be contained in the core substance of the capsule or may be added outside the microcapsule as a dispersion.

For general techniques of microencapsulation and materials to be used, see US Pat. No. 3,726,804,
No. 3,796,696, and can be applied to the present invention.

The size of the microcapsules is preferably not more than 5 μm and not less than 0.02 μm, more preferably not less than 0.02 μm in terms of volume average, particularly from the viewpoint of improving the resolution of images and handling.
It is preferable to adjust the thickness within a range of from 0.5 to 0.7 μm.

(2) A hydrophobizing precursor containing a polymerizable monomer / crosslinkable compound and forming a hydrophobic polymer / crosslinked structure in the vicinity of particles with thermal destruction. The hydrophobizing precursor described as the above item (2) does not react at room temperature, has a heat-reactive functional group where polymerization or crosslinking reaction starts by the action of heat, and hydrophobizes the vicinity of the precursor particles. It is a dispersion containing a polymerizable monomer and a crosslinkable compound. Examples of such a system include a polymerizable monomer which undergoes a polymerization reaction, particularly a crosslinking reaction, at a high temperature, a system containing a heat-crosslinkable polymer or oligomer having a crosslinking group, and a thermal polymerization initiator. In order to make the surface of the dispersion hydrophilic, the dispersion can be dispersed by using the surface hydrophilizing means described above in the section of the hydrophobizing precursor.

As the above-mentioned heat-reactive functional group, an ethylenically unsaturated group which undergoes a polymerization reaction (for example, an acryloyl group,
A methacryloyl group, a vinyl group, an allyl group, etc.), an isocyanate group for performing an addition reaction or a block thereof and a functional group having an active hydrogen atom as a reaction partner thereof (for example, an amino group, a hydroxyl group, a carboxyl group, etc.), Epoxy group and addition partner amino group, carboxyl group or hydroxyl group for addition reaction, carboxyl group and hydroxyl group or amino group for condensation reaction, acid anhydride and amino group or hydroxyl group for ring opening addition reaction, etc. Can be mentioned. However, a functional group that performs any reaction may be used as long as a chemical bond is formed.

As the fine particle polymer having a thermoreactive functional group used in the hydrophilic layer of the present invention, acryloyl group, methacryloyl group, vinyl group, allyl group, epoxy group,
Examples thereof include an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, an acid anhydride and those having a group protecting them. The introduction of these functional groups into the polymer particles may be performed at the time of polymerization, or may be performed using a polymer reaction after polymerization.

When introduced at the time of polymerization, it is preferable to carry out emulsion polymerization or suspension polymerization of monomers having these functional groups. Specific examples of the monomer having such a functional group include allyl methacrylate, allyl acrylate, vinyl methacrylate, vinyl acrylate, glycidyl methacrylate, glycidyl acrylate,
Block isocyanate with isocyanate ethyl methacrylate or its alcohol, block isocyanate with 2-isocyanate ethyl acrylate or its alcohol, 2-aminoethyl methacrylate, 2-aminoethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, Examples include, but are not limited to, acrylic acid, methacrylic acid, maleic anhydride, bifunctional acrylate, bifunctional methacrylate, and the like. Examples of the monomer having no heat-reactive functional group copolymerizable with these monomers include, for example, styrene, alkyl acrylate, alkyl methacrylate, acrylonitrile, and vinyl acetate. The monomer is not limited to these as long as it has no monomer. As the polymer reaction used when the heat-reactive functional group is introduced after the polymerization, for example, WO96-34316
The polymer reaction described in Japanese Patent Application Laid-Open No. H10-260, can be mentioned.

Among the fine particle polymers having a heat-reactive functional group, those in which the fine particle polymers are united by heat are preferable, and those whose surfaces are hydrophilic and which are dispersed in water are particularly preferable. The contact angle (water droplets in the air) of a film produced by applying only the fine particle polymer and drying at a temperature lower than the coagulation temperature is lower than the contact angle of the film produced by drying at a temperature higher than the coagulation temperature ( (Water droplets in the air). In order to make the surface of the fine particle 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 fine particle polymer. However, the present invention is not limited to this.

The solidification temperature of these fine particles of a polymer having a thermoreactive functional group is preferably 70 ° C. or higher, and more preferably 100 ° C. or higher in view of stability over time. The average particle size of the fine particle polymer is preferably 0.01 to 20 μm, more preferably 0.05 to 2.0 μm, and most preferably 0.1 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.

The addition amount of the fine particle polymer having a reactive functional group is preferably 50% by weight or more, more preferably 60% by weight or more of the solid content of the heat-sensitive layer.

The microcapsules used in the present invention are:
A compound having a thermoreactive functional group may be included. Compounds having this heat-reactive functional group include polymerizable unsaturated groups, hydroxyl groups, carboxyl groups or carboxylate groups or acid anhydrides, amino groups, epoxy groups,
And a compound having at least one functional group selected from an isocyanate group or a block thereof.

The compound having a polymerizable unsaturated group includes
At least one ethylenically unsaturated bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group;
And preferably two or more compounds. Such a compound group is widely known in the industrial field, and in the present invention, these can be used without particular limitation. These are, in chemical form, monomers, prepolymers, ie, dimers, trimers and oligomers, or mixtures thereof, or copolymers thereof.

Examples include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids and fatty acids. Esters with aliphatic polyhydric alcohols and amides of unsaturated carboxylic acids with aliphatic polyhydric amines. Also,
An addition reaction product of an unsaturated carboxylic acid ester or unsaturated carboxylic acid amide having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group with a monofunctional or polyfunctional isocyanate or an epoxide; A dehydration-condensation reaction product with a functional carboxylic acid is also preferably used. Further, an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group, and a monofunctional or polyfunctional alcohol,
Addition reactants with amines and thiols, and also substituted reactants with unsaturated carboxylic esters or amides having a leaving group such as a halogen group or tosyloxy group, and monofunctional or polyfunctional alcohols, amines and thiols. It is suitable. Another preferred example is a compound in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid or chloromethylstyrene.

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

Examples of methacrylic acid esters 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- Methacryloyloxy-2 Hydroxypropoxy) phenyl]
Examples thereof include dimethylmethane and bis- [p- (methacryloyloxyethoxy) phenyl] dimethylmethane.

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

The crotonates include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like can be mentioned. Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Maleic esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate,
Sorbitol tetramalate and the like can be mentioned.

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
Examples thereof include those having an aromatic skeleton described in JP-A-5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613.

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 thereof include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, and xylylenebismethacrylamide. 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 and an unsaturated monomer having a hydroxyl group represented by the following formula (I) added to one molecule. Urethane compounds containing at least two polymerizable unsaturated groups are exemplified. General formula (I) CH2 = C (R1) COOCH2CH (R2) OH (where R1 and R2 represent H or CH3)

Further, urethane acrylates described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and JP-B-58-4
9860, JP-B-56-17654, JP-B-62-
Urethane compounds having an ethylene oxide skeleton described in 39417 and JP-B-62-39418 are also preferable.

Further, radically 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 are preferable. It can be mentioned as.

Examples of other suitable compounds include polyester acrylates and epoxy resins described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490. Examples thereof include polyfunctional acrylates and methacrylates such as epoxy acrylates obtained by reacting a resin with (meth) acrylic acid. In addition, JP-B-46-43946,
Specific unsaturated compounds described in JP-B-1-40337 and JP-A-1-40336 and vinylphosphonic acid-based compounds described in JP-A-2-25493 can also be mentioned as preferable ones. In some cases, compounds containing a perfluoroalkyl group described in JP-A-61-22048 are also preferably used. Furthermore, The Journal of the Adhesion Society of Japan, Vol. 20, No. 7, pp. 300-308 (198
Those introduced as photocurable monomers and oligomers in (4 years) can also be suitably used.

Suitable epoxy compounds include glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene diglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, bisphenols and polyphenols, and hydrogenated products thereof. And polyglycidyl ether.

Preferred isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, cyclohexane phenylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, cyclohexyl diisocyanate, and alcohols such as alcohols. Alternatively, a compound blocked with an amine can be mentioned.

Suitable amine compounds include ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, propylenediamine, polyethyleneimine and the like.

Suitable compounds having a hydroxyl group include compounds having a terminal methylol group, polyhydric alcohols such as pentaerythritol, and bisphenols and polyphenols. Preferred compounds having a carboxyl group include pyromellitic acid, trimellitic acid, aromatic polycarboxylic acids such as phthalic acid,
Examples include aliphatic polycarboxylic acids such as adipic acid. Suitable acid anhydrides include pyromellitic anhydride, benzophenonetetracarboxylic anhydride and the like.

Preferred copolymers of the ethylenically unsaturated compound include allyl methacrylate copolymers. For example, an allyl methacrylate / methacrylic acid copolymer, an allyl methacrylate / ethyl methacrylate copolymer, an allyl methacrylate / butyl methacrylate copolymer, and the like can be given.

Since the fine particle polymer or the microcapsule having a heat-reactive group is used in the image recording layer of the present invention, a compound for initiating or promoting these reactions may be added as necessary. Examples of the compound that initiates or promotes the reaction include compounds that generate radicals or cations by heat, and include, for example, lophine dimers, trihalomethyl compounds, peroxides, azo compounds, diazonium salts, and diphenyliodonium salts. Onium salts, acylphosphines, imidosulfonates and the like.
These compounds can be added in the range of 1 to 20% by weight of the solid content of the heat-sensitive layer. Preferably 3 to 10% by weight
Range. Within this range, the on-press developability is not impaired,
Good reaction initiation or promotion effect can be obtained.

These polymerizable and crosslinkable organic compounds are added in an amount of 5 to 95% by weight based on the total amount of the hydrophobic precursor.
Is suitable, preferably 20 to 90% by weight, and most preferably substantially 300 to 80% by weight.

(Hydrophilic Medium) The hydrophobizing precursor having a hydrophilic surface and the photothermal conversion agent having a hydrophilic surface or a hydrophilic surface are described in the hydrophilic image recording layer of the present invention. Was. Next, the configuration of the hydrophilic medium of the image recording layer will be described.

The hydrophilic medium includes a hydrophilic polymer, a sol-gel conversion material composed of a system of a metal hydroxide and a metal oxide,
The purpose of controlling the degree of hydrophilicity such as hydrophilic sol particles and other secondary components such as dyes and surfactants, improving the physical strength of the recording layer, improving the dispersibility of the constituents of the layer, and coating The composition is selected from a variety of compounds for various purposes such as improvement of printing properties, improvement of printing suitability, and convenience of plate making work. The hydrophilic image recording layer is particularly preferably a sol-gel conversion system in the present invention. Among them, a sol-gel conversion system having a property of forming a gel structure of polysiloxane is preferable.

<Sol-Gel Conversion System Medium> A particularly preferable medium for the image recording layer of the present invention is a sol-gel conversion system described below. That is, the coating liquid is in a sol state, but is dried after being applied and becomes a gel state with the passage of time, and can be applied to a printing plate. The sol-gel conversion system preferably applicable to the present invention is a system in which a bonding group derived from a polyvalent element forms a network structure via an oxygen atom, and at the same time, the polyvalent metal has an unbonded hydroxyl group or an alkoxy group. It is a polymer that has a resin-like structure in which these are mixed, and is in a sol state at the stage where there are many alkoxy groups and hydroxyl groups before application, and as the ester bonding progresses after application, The network-like resinous structure becomes strong and becomes a gel state. Also,
In addition to the property of changing the degree of hydrophilicity of the resin tissue, the resin has a function of modifying the surface of the solid fine particles by binding a part of hydroxyl groups to the solid fine particles, thereby changing the degree of hydrophilicity. The polyvalent bonding element of the compound having a hydroxyl group or an alkoxy group that undergoes sol-gel conversion is aluminum, silicon, titanium, zirconium, or the like, and any of these can be used in the present invention, but the following are most preferably used. A sol-gel conversion system using a siloxane bond will be described. The sol-gel conversion using aluminum, titanium and zirconium can be performed by substituting silicon for each element described below.

Hereinafter, a system utilizing the sol-gel conversion will be further described. It is preferably a resin having a siloxane bond and a silanol group formed by sol-gel conversion, the image recording layer of the lithographic printing plate precursor of the present invention,
This is a sol system containing a silane compound having at least one silanol group. During the elapse of time after application, hydrolysis and condensation of the silanol group proceeds, a siloxane skeleton structure is formed, and gelation proceeds. The layer formed by the sol-gel conversion has a high degree of hydrophilicity, and thus has a high degree of discrimination from the hydrophobized region, which is an advantage of the present invention. A compound recording layer formed by adding a material for the purpose of improving physical properties such as an organic polymer to be described later, improving coatability, or the like in the medium having the gel structure is preferably used. The siloxane resin forming a gel structure is represented by the following general formula (I), and the silane compound having at least one silanol group is represented by the following general formula (II)
Indicated by Further, the substance system that changes from hydrophilic to hydrophobic contained in the image recording layer does not necessarily need to be a silane compound of the general formula (II) alone, and generally comprises an oligomer obtained by partially hydrolyzing the silane compound. Or a mixed composition of a silane compound and its oligomer.

[0133]

Embedded image

The siloxane resin represented by the general formula (I) is
It is formed by sol-gel conversion from a dispersion containing at least one silane compound represented by the following general formula (II), and at least one of R ^{01 to} R ^{03 in} the general formula (I) represents a hydroxyl group; Others represent organic residues selected from the symbols R ⁰ and Y in the following general formula (II).

Formula (II) (R ⁰ ) _n Si (Y) _{4-n In} formula (II), at least one of R ⁰ represents a hydroxyl group, and the other represents a hydrocarbon group or a heterocyclic group. Express. Y
Represents a hydrogen atom, a halogen atom, —OR ¹ , —OCOR ² , or —N (R ³ ) (R ⁴ ) (R ¹ and R ² each represent a hydrocarbon group, and R ³ and R ⁴ represent They may be the same or different and represent a hydrogen atom or a hydrocarbon group). n represents 1, 2 or 3.

Preferably, R ⁰ in the general formula (II) is a hydroxyl group, but other than the hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms which may be substituted (for example, methyl Group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, etc .; As a group substituted by these groups, a halogen atom (chlorine atom, Fluorine atom,
Bromine atom, hydroxy group, thiol group, carboxy group, sulfo group, cyano group, epoxy group, -OR 'group (R' is methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, octyl Group, decyl group,
Propenyl group, butenyl group, hexenyl group, octenyl group, 2-hydroxyethyl group, 3-chloropropyl group,
2-cyanoethyl group, N, N-dimethylaminoethyl group, 2-bromoethyl group, 2- (2-methoxyethyl)
Oxyethyl group, 2-methoxycarbonylethyl group, 3
-Carboxypropyl group, benzyl group, etc.),

A -OCOR "group (R" represents the same content as the above R '), a -COOR "group, a -COR" group,-
N (R ′ ″) (R ″ ′) (R ″ ″ represents the same content as a hydrogen atom or R ′ and may be the same or different), —NHCONHR ″ group, —NHCOOR ″ Group,-
Si (R ″) ₃ group, —CONHR ″ ′ group, —NHCO
R "group and the like. These substituents may be substituted plurally in the alkyl group, and a linear or branched alkenyl group having 2 to 12 carbon atoms which may be substituted (for example,
Vinyl group, propenyl group, butenyl group, pentenyl group,
The group substituted by these groups, such as hexenyl group, octenyl group, decenyl group, dodecenyl group, and the like, include those having the same contents as the group substituted by the alkyl group.) Aralkyl groups which may be substituted (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, etc .; the group substituted by these groups is the above-mentioned alkyl group Groups having the same contents as the group, and may be substituted plurally),

An optionally substituted alicyclic group having 5 to 10 carbon atoms (for example, cyclopentyl, cyclohexyl, 2
-Cyclohexylethyl group, 2-cyclopentylethyl group, norbornyl group, adamantyl group and the like, the group substituted with these groups include those having the same contents as the substituents of the alkyl group, and those substituted with a plurality of And a substituted or unsubstituted aryl group having 6 to 12 carbon atoms (e.g., a phenyl group or a naphthyl group, examples of the substituent include those having the same contents as the group substituted with the alkyl group.
Two or more may be substituted), or a nitrogen atom, an oxygen atom,
A condensable heterocyclic group containing at least one atom selected from sulfur atoms (for example, the heterocyclic ring includes a pyran ring, a furan ring, a thiophene ring, a morpholine ring, a pyrrole ring, a thiazole ring, an oxazole ring , A pyridine ring, a piperidine ring, a pyrrolidone ring, a benzothiazole ring, a benzoxazole ring, a quinoline ring, a tetrahydrofuran ring, etc., which may contain a substituent. The contents of which may be mentioned, and a plurality may be substituted).

Preferably Y is a halogen atom (representing a fluorine, chlorine, bromine or iodine atom),-
Represents an OR ¹ group, a —OCOR ² group, or a —N (R ³ ) (R ⁴ ) group. In the —OR ¹ group, R ¹ represents an optionally substituted aliphatic group having 1 to 10 carbon atoms (eg, a methyl group, an ethyl group,
Propyl, butoxy, heptyl, hexyl, pentyl, octyl, nonyl, decyl, propenyl, butenyl, heptenyl, hexenyl, octenyl, decenyl, 2-hydroxyethyl, 2-hydroxyethyl
Hydroxypropyl group, 2-methoxyethyl group, 2-
(Methoxyethyloxo) ethyl group, 2- (N, N-diethylamino) ethyl group, 2-methoxypropyl group,
-Cyanoethyl group, 3-methyloxapropyl group, 2-
Chloroethyl, cyclohexyl, cyclopentyl, cyclooctyl, chlorocyclohexyl, methoxycyclohexyl, benzyl, phenethyl, dimethoxybenzyl, methylbenzyl, bromobenzyl, etc.).

In the —OCOR ² group, R ² is an aliphatic group having the same content as R ¹ or an aromatic group having 6 to 12 carbon atoms which may be substituted (the aromatic group is an aryl group in the aforementioned R). And the same as those exemplified for the group). In the —N (R ³ ) (R ⁴ ) group, R ³ and R ⁴ may be the same or different from each other.
10 optionally substituted aliphatic groups (for example, -O
R ¹ has the same contents as R ¹ ). More preferably, the total number of carbon atoms of R ¹ and R ² is up to 16. Specific examples of the silane compound represented by the general formula (II) include the following, but are not limited thereto.

Methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-t-butoxysilane, ethyltrichlorosilane, ethyltribromosilane, ethyltrimethoxysilane, ethyltrimethoxysilane Ethoxysilane, ethyltriisopropoxysilane, ethyltri-t-butoxysilane, n-propyltrichlorosilane, n-propyltribromosilane, n-
Propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltriisopropoxysilane, n
-Propyltri-t-butoxysilane, n-hexyltrichlorosilane, n-hexyltribromosilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-hexyltriisopropoxysilane, n-
Hexyltri-t-butoxysilane, n-decyltrichlorosilane, n-decyltribromosilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, n
-Decyltriisopropoxysilane, n-decyltri-t
-Butoxysilane, n-octadecyltrichlorosilane, n-octadecyltribromosilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane, n-octadecyltriisopropoxysilane, n-octadecyltri-t-butoxysilane,

Phenyltrichlorosilane, phenyltribromosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriisopropoxysilane, phenyltri-t-butoxysilane, tetrachlorosilane, tetrabromosilane, tetramethoxysilane, tetraethoxysilane , Tetraisopropoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane, dimethyldichlorosilane, dimethyldibromosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldichlorosilane, diphenyldibromosilane,
Diphenyldimethoxysilane, diphenyldiethoxysilane, phenylmethyldichlorosilane, phenylmethyldibromosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, triethoxyhydrosilane, tribromohydrosilane, trimethoxyhydrosilane, isopropoxyhydrosilane, tri-t -Butoxyhydrosilane, vinyltrichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltri-t-butoxysilane, trifluoropropyltrichlorosilane, trifluoropropyltribromosilane, trifluoro Propyltrimethoxysilane, trifluoropropyltriethoxysilane,

Trifluoropropyltriisopropoxysilane, trifluoropropyltri-t-butoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane , Γ
-Glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriisopropoxysilane, γ-glycidoxypropyltri-t-butoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldi Ethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriisopropoxysilane, γ-
Methacryloxypropyltri-t-butoxysilane, γ
-Aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltrit-butoxysilane , Γ-
Mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri-t-
Butoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane and the like.

Along with the silane compound represented by the general formula (II) used for forming the image recording layer of the present invention, Ti, Zn,
Metal compounds capable of forming a film by binding to a resin during sol-gel conversion, such as Sn, Zr, and Al, can be used in combination. As the metal compound used, for example, Ti (OR ″) ₄
(R ″ represents a methyl group, an ethyl group, a propyl group, a butyl group,
Pentyl group, hexyl group, etc.), TiCl ₄ , Zn (O
R ″) ₂ , Zn (CH ₃ COCHCOCH ₃ ) ₂ , Sn (O
R ″) ₄ , Sn (CH ₃ COCHCOCH ₃ ) ₄ , Sn (O
COR ″) ₄ , SnCl ₄ , Zr (OR ″) ₄ , Zr (C
H ₃ COCHCOCH ₃ ) ₄ , Al (OR ″) _{3 and the} like.

Further, in order to promote the hydrolysis and polycondensation reaction of the silane compound represented by the general formula (II) and the metal compound used in combination, it is preferable to use an acidic catalyst or a basic catalyst in combination. As the catalyst, an acid or basic compound used as it is or in a state of being dissolved in a solvent such as water or alcohol (hereinafter referred to as an acidic catalyst or a basic catalyst, respectively) is used. The concentration at that time is not particularly limited, but when the concentration is high, hydrolysis,
The polycondensation rate tends to increase. However, when a highly concentrated basic catalyst is used, a precipitate may be formed in the sol solution. Therefore, the concentration of the basic catalyst is preferably 1 N (concentration conversion in an aqueous solution) or less.

The type of the acidic catalyst or the basic catalyst is not particularly limited, but when it is necessary to use a catalyst having a high concentration, a catalyst composed of an element which hardly remains in the catalyst crystal grains after sintering is used. Good. Specifically, examples of the acidic catalyst include hydrogen halides such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid,
Examples of basic catalysts include carboxylic acids such as formic acid and acetic acid, substituted carboxylic acids in which R of the structural formula represented by RCOOH is substituted with another element or a substituent, sulfonic acids such as benzenesulfonic acid, and the like. Examples include ammoniacal bases and amines such as ethylamine and aniline.

As described above, the image recording layer formed by the sol-gel method is particularly preferable for the lithographic printing plate precursor according to the invention. Further details of the above sol-gel method,
Saio Sakuhana, "Science of Sol-Gel Method", Agne Shofusha Co., Ltd. (published) (1988), Hirashima Tsuyoshi, "Functional Thin Film Fabrication Technology by Latest Sol-Gel Method," Integrated Technology Center (published) (19)
1992) and the like.

<Hydrophilic high molecular compound> The high molecular compound contained in the image recording layer of the lithographic printing plate precursor according to the present invention is intended for imparting appropriate strength as an image recording layer and surface hydrophilicity. And an organic polymer compound having a hydroxyl group. Specifically, polyvinyl alcohol (PVA), modified PVA such as carboxy-modified PVA, starch and derivatives thereof, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose,
Water-soluble acrylic monomers such as casein, gelatin, polyvinylpyrrolidone, vinyl acetate-crotonic acid copolymer, styrene-maleic acid copolymer, polyacrylic acid and its salts, polyacrylamide, and acrylic acid and acrylamide are mainly used. A water-soluble resin such as a water-soluble acrylic copolymer contained as a constituent component is exemplified.

Examples of the waterproofing agent for crosslinking and curing the above-mentioned organic polymer compound having a hydroxyl group include an initial condensate of aminoplasts such as glyoxal, melamine formaldehyde resin and urea formaldehyde resin, a methylolated polyamide resin, a polyamide. Examples thereof include a polyamine / epichlorohydrin adduct, a polyamide epichlorohydrin resin, and a modified polyamide polyimide resin. In addition, a crosslinking catalyst of ammonium chloride, a silane coupling agent, or the like can be used in combination.

<Other components to be added to the image recording layer>-Hydrophilic sol particles The image recording layer of the lithographic printing plate precursor according to the invention is composed of the photothermal conversion agent system, the hydrophobizing precursor, the hydrophilicity improving agent, and the like. In addition to the organic polymer compound having a hydroxyl group for improving film properties, hydrophilic sol-like particles may be further contained.

The hydrophilic sol particles are not particularly limited, but are preferably silica sol, alumina sol, alumina / silica composite sol, titanium oxide, magnesium oxide,
Magnesium carbonate and calcium alginate, which are not light-to-heat conversion, can promote hydrophilicity and can be used for strengthening sol-gel films. More preferably, it is a silica sol, an alumina sol, an alumina / silica composite sol, or a mixture thereof.

The silica sol has many hydroxyl groups on the surface, and the inside of the silica sol forms a siloxane bond (—Si—O—Si). Ultrafine silica particles having a particle diameter of 1 to 100 nm,
It is dispersed in water or a polar solvent, and is also called colloidal silica. Specifically, Toshiro Kaga and Ei Hayashi supervised “Applied Technology of High Purity Silica” Volume 3,
Co., Ltd. (1991).

The alumina sol is an alumina hydrate (boehmite) having a colloidal size of 5 to 200 nm.
And an anion (for example, a halogen ion such as a fluorine ion or a chloride ion, or a carboxylate anion such as an acetate ion) in water is dispersed as a stabilizer.

The hydrophilic sol particles have an average particle diameter of 10
The average particle size is preferably from 10 to 40 nm, more preferably from 10 to 40 nm. All of these hydrophilic sol-like particles can be easily obtained as commercial products.

When the particle diameter of the hydrophilic sol particles (collectively referred to simply as silica particles) used in the present invention is within the above range, the film strength of the image recording layer is sufficiently maintained. When a plate is made by exposing to light with a laser beam or the like and printed as a printing plate, an effect of extremely excellent hydrophilicity that does not cause adhesion of printing ink to a non-image portion is exhibited. When the hydrophilic sol particles are added to the image recording layer, the amount of the hydrophilic sol particles is 5 to 80% by weight, preferably 20 to 6% by weight of the fixed component of the image recording layer.
0% by weight.

Surfactant In the image forming layer of the lithographic printing plate precursor according to the invention, JP-A-62-2517 is used in order to enhance stability under printing conditions.
Non-ionic surfactants described in JP-A-59-121 and JP-A-3-208514.
Further, an amphoteric surfactant as described in JP-A-0444 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 alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-N, N- Betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.) and the like. The proportion of the nonionic surfactant and amphoteric surfactant in the total solids of the image forming layer is preferably 0.05 to 15% by weight,
More preferably, it is 0.1 to 5% by weight.

In the image recording layer, if necessary, a fluorine-based surfactant may be used within the range of the above-mentioned surfactant. Specifically, a surfactant having a perfluoroalkyl group is preferable, and a carboxylic acid, a sulfonic acid, an anionic surfactant having any of a sulfate ester and a phosphate ester, or an aliphatic amine,
Cationic surfactants such as quaternary ammonium salts, or betaine-type amphoteric surfactants, or nonionic surfactants such as aliphatic esters of polyoxy compounds, polyalkylene oxide condensate, and polyethyleneimine condensate Agents and the like.

Solvent The coating solution for the image recording layer is a water solvent, and a water-soluble solvent is used in combination for the purpose of uniform liquefaction by suppressing precipitation during preparation of the coating solution. As the water-soluble solvent, 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.) And amides (formamide, N-methylformamide, pyrrolidone, N-methylpyrrolidone, etc.) and the like, and one type or two or more types may be used in combination. These solvents are used alone or as a mixture. When preparing a coating solution, the concentration of the above-mentioned components of the image forming layer (total solid content including additives) in the solvent is preferably 1 to 50% by weight.

[Coating] The components selected from the above-mentioned components are mixed, and the prepared coating solution is coated and dried on the support by any of the conventionally known coating methods.
Form a film. As a method of applying, various known methods can be used. For example, bar coater coating, spin coating, spray coating, curtain coating, dip coating,
Examples include air knife application, blade application, roll application, and the like. In the image forming layer of the lithographic printing plate precursor according to the invention, a surfactant for improving coating properties, for example, a fluorine-based surfactant described in JP-A-62-170950 is used. Can be added. The preferred addition amount is 0.01 to 0.01% based on the total solid content of the image forming layer.
1% by weight, and more preferably 0.05 to 0.5% by weight.

The coating amount (solid content) of the image forming layer obtained after coating and drying varies depending on the application, but is generally 0.5 to 5.0 g / m ² for a general lithographic printing plate precursor. 0.5-2.0 g / m < ² > is more preferable.

Since the surface of the lithographic printing plate precursor of the present invention is hydrophilic, it becomes hydrophobic under the influence of the environment atmosphere during handling before use, is affected by temperature and humidity, or has mechanical scratches. Susceptible to contamination or dirt. Normally, surface smoothing solution (also called gum solution) is applied to the plate surface during the plate making process
Protective effect is obtained by applying a protective liquid during the production of an original plate, and this protective effect can be obtained immediately after the production, and the time required to apply a new surface conditioning liquid in the plate making process. However, there is an advantage that workability is improved by omitting the above, and this effect is particularly large in the present invention having a hydrophilic surface. Therefore, as a preferred embodiment of the present invention, as described above, a water-soluble protective layer is provided on the image recording layer. The content of the surface protective layer is the same as that of the surface-conditioning solution (gum solution), and the details will be described later in the application section as “surface-conditioning solution”.

[Support] Next, the substrate on which the image recording layer is coated will be described. A dimensionally stable plate is used for the substrate. Examples of the substrate that can be used in the present invention include paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, nickel, stainless steel, etc.), plastic film (For example, 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 substrates are polyester films,
Aluminum or a SUS steel plate that is hardly corroded on a printing plate, and among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and containing a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include:
Silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. Particularly preferred aluminum in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element.
As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the substrate used in the present invention is approximately 0.05 mm to 0.1 mm.
It is about 6 mm, preferably 0.1 mm to 0.4 mm, particularly preferably 0.15 mm to 0.3 mm.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like is performed to remove rolling oil on the surface. The surface roughening treatment of the aluminum plate may or may not be performed. There are various methods for performing the method. For example, the method is performed by a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of chemically selectively dissolving the surface. 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. As a chemical method, a method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in JP-A-54-31187 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, Japanese Patent Application Laid-Open
An electrolytic surface roughening method using a mixed acid as disclosed in US Pat. Among such surface-roughening methods, a surface-roughening method combining mechanical surface-roughening and electrochemical surface-roughening as described in JP-A-55-137993 is particularly preferred. Is preferred because of its strong adhesion to the support.

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 subjected to a neutralization treatment. Anodizing is applied to increase the height.

As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes for forming a porous oxide film can be used. Generally, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. Can be The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte. Anodizing treatment conditions vary depending on the electrolyte to be used, and thus cannot be specified unconditionally.
~ 80 wt% solution, liquid temperature 5 ~ 70 ° C, current density 5 ~ 6
0 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 oxide film formed is
1.0 to 5.0 g / m ² , particularly 1.5 to 4.0 g / m ²
It is preferable that The amount of anodized film is 1.0 g / m ²
If the amount is smaller, the printing durability becomes insufficient.

Among these anodic oxidation treatments, in particular, a method of anodizing at a high current density in sulfuric acid described in British Patent No. 1,412,768 and US Pat. No. 3,511,661. The method of anodizing using phosphoric acid as an electrolytic bath described in above is preferable.

The above preferably roughened and further anodized aluminum plate may be subjected to a hydrophilizing treatment, if necessary. A preferred example is US Pat.
Alkali metal silicates such as those disclosed in U.S. Pat. Nos. 4,066 and 3,181,461, such as aqueous sodium silicate or potassium fluorzirconate disclosed in JP-B-36-22063 and U.S. Pat. There is a method of treating with polyvinyl phosphonic acid as disclosed in Japanese Patent No. 4,153,461. Background dirt can often be prevented by the hydrophilic treatment.

The aluminum plate and the SUS plate may be provided with an organic undercoat layer if necessary before coating the photosensitive layer. Examples of the organic compound used in the organic undercoat layer include carboxymethyl cellulose, dextrin, gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, phenylphosphonic acid which may have a substituent, and naphthyl. Organic phosphonic acids such as phosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, and organic acids such as phenylphosphoric acid, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid which may have a substituent. Phosphoric acid esters, organic phosphinic acids such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent, amino acids such as glycine and β-alanine, and hydrochloride of triethanolamine Such as hi Although selected from such as hydrochloric acid salt of an amine having a Rokishiru group, it may be used as a mixture of two or more thereof.

The organic undercoat layer can be provided by the following method. That is, a method in which a solution obtained by dissolving the above organic compound in water or an organic solvent such as methanol, ethanol, or methyl ethyl ketone or a mixed solvent thereof is coated on an aluminum plate and dried, and a method in which water or methanol, ethanol, methyl ethyl ketone, or the like is used. An aluminum plate is immersed in a solution in which the above organic compound is dissolved in an organic solvent or a mixed solvent thereof to adsorb the organic compound, and thereafter, washed with water or the like and dried to form an organic undercoat layer. Is the way. In the former method, a solution of the above organic compound having a concentration of 0.005 to 10% by weight can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, and curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 20% by weight.
-5% by weight, the immersion temperature is 20-90 ° C., preferably 25-50 ° C., and the immersion time is 0.1 second-20 minutes,
Preferably it is 2 seconds to 1 minute. The pH of the solution used for this can be adjusted with a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, or an acidic substance such as hydrochloric acid or phosphoric acid.
Further, a yellow dye can be added for improving the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the organic undercoat layer after drying is suitably from ² to 200 mg / m ² , and preferably from 5 to 100 mg / m ² . The above coating amount is 2mg
/ M ² , sufficient printing durability cannot be obtained. The same is true even if it is larger than 200 mg / m ² .

[Other Layers] A back coat is provided on the back surface of the support, if necessary. Such a back coat comprises an organic polymer compound described in JP-A-5-45885 and a metal oxide obtained by hydrolyzing and polycondensing an organic or inorganic metal compound described in JP-A-6-35174. A coating layer is preferably used. Among these coating layers, Si (OCH ₃ ) ₄ and Si (OC ₂ H ₅ )
₄ , Si (OC ₃ H ₇ ) ₄ , silicon alkoxy compounds such as Si (OC ₄ H ₉ ) ₄ are easily available at a low cost, and the metal oxide coating layer obtained therefrom is particularly preferable because of its excellent hydrophilicity. .

[Plate making method] Next, a plate making method of the lithographic printing plate precursor will be described. The lithographic printing plate precursor is, for example, subjected to direct thermal image recording by a thermal recording head or the like, or a solid laser or semiconductor laser that emits infrared light having a wavelength of 760 to 1200 nm, a high-intensity flash light such as a xenon discharge lamp, or the like. Light-to-heat conversion type exposure such as infrared lamp exposure can also be used.

The writing of the image may be performed by either a surface exposure method or a scanning method. In the former case, an infrared irradiation method,
This is a method of irradiating a short time light of high illuminance of a xenon discharge lamp onto an original plate 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 being modulated with a print image is 0.1 to 10 J / cm ² . It is preferably in the range, more preferably 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 preferably selected such that the above-mentioned exposure intensity is obtained by irradiation of 0.01 to 1 msec, preferably 0.01 to 0.1 msec. 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 printing image is in the range of 0.1 to 10 J / cm ² .
More preferably, it is in the range of ^{3 to 1} J / cm ² . When the support is transparent, exposure can be performed through the support from the back side of the support.

When making a lithographic printing plate, after image exposure, if necessary, a surface conditioning agent containing a plate surface protective agent (so-called gum solution) is applied to protect the non-image area. Is performed. Gum-pulling is a period of time before printing after plate making to prevent the hydrophilic surface of the lithographic printing plate from being reduced in hydrophilicity by the influence of trace components in the air and to increase the hydrophilicity of non-image areas. In order to prevent the lithographic printing plate from deteriorating between the time when printing is interrupted and the time when printing is restarted, oil or ink on the finger may adhere when handling the lithographic printing plate, such as when attaching it to a printing press. In order to prevent the non-image from becoming ink-receptive and to be stained, and to prevent the non-image portion and the image portion from being damaged when handling the lithographic printing plate,
It is performed for various purposes such as.

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

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

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

In addition to the above components, if necessary, lower polyhydric alcohols such as glycerin, ethylene glycol and triethylene glycol can be used as wetting agents. The use amount of these wetting agents is suitably 0.1 to 5.0% by weight in the protective agent, and the preferred range is 0.5 to 3.0% by weight. In addition to the above, the surface protective agent for a lithographic printing plate of the present invention includes:
Preservatives and the like can be added. For example, benzoic acid and its derivatives, phenol, formalin, sodium dehydroacetate and the like can be added in the range of 0.005 to 2.0% by weight. An antifoaming agent may be added to the plate surface protective agent. Preferred antifoaming agents include an organic silicone compound, and the amount added is preferably in the range of 0.0001 to 0.1% by weight.

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

The plate surface protective agent can take any form of a uniform solution type, a suspension type, and an emulsion type. Particularly, the emulsion type containing an organic solvent as described above exhibits excellent performance. In this case, it is preferable to incorporate a surfactant in combination as described in JP-A-55-105581.

[0182]

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

(1) Preparation of Substrate 0.01% by weight of copper to 99.5% by weight of aluminum
A 0.24 mm-thick rolled plate of JIS A1050 aluminum material containing 0.03% by weight of titanium, 0.3% by weight of iron, and 0.1% by weight of silicon was converted to 20% by weight of 400 mesh pumice stone (manufactured by Kyoritsu Ceramics). The surface was grained using an aqueous suspension and a rotating nylon brush (6,10-nylon), and then thoroughly washed with water. This was added to a 15% by weight aqueous sodium hydroxide solution (4.5% by weight of aluminum).
) And etched so that the amount of aluminum dissolved was 5 g / m ² , followed by washing with running water. Further, the mixture was neutralized with 1% by weight of nitric acid, and then charged in an aqueous solution of 0.7% by weight of nitric acid (containing 0.5% by weight of aluminum) with an anode voltage of 10.5%.
Volts and a cathodic voltage of 9.3 volts, using a rectangular wave alternating waveform voltage (current ratio r = 0.90, current waveform described in Examples of Japanese Patent Publication No. 58-5796) of 160 clones / dm ² . The electrolytic surface roughening treatment was performed with the quantity of electricity at the anode. After washing with water, it was immersed in a 10% by weight aqueous solution of sodium hydroxide at 35 ° C., etched so that the amount of aluminum dissolved was 1 g / m ² , and then washed with water. Next, at 50 ° C., 30% by weight
Immersed in an aqueous sulfuric acid solution, desmutted, and washed with water.

Further, a porous anodic oxide film forming treatment was carried out in a 20% by weight aqueous sulfuric acid solution (containing 0.8% by weight of aluminum) at 35 ° C. 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. After washing this support with water,
It was immersed in a 3% by weight aqueous solution of sodium silicate at 70 ° C. for 30 seconds, washed with water and dried. The aluminum support obtained as described above had a reflection density measured by a Macbeth RD920 reflection densitometer of 0.30 and a center line average roughness of 0.58 μm.

(2) Preparation of Hydrophobizing Precursor The following seven kinds of hydrophobizing precursors of the present invention and three kinds of non-present hydrophobizing precursors were prepared. <Precursor A: Composite particle 1 of hetero-aggregated surface layer> 70 g of styrene, trimethoxysilylpropyl methacrylate 3
0 g, 200 g of water, and 10 g of a surfactant XL-102F (manufactured by Lion Corporation) (4.7% aqueous solution) were placed in a three-necked flask, and heated to 80 ° C. while introducing nitrogen. Thereafter, after stirring for about 30 minutes, 1 g of K ₂ S ₂ O ₈ was added, and 80 ° C.
For 6 hours to obtain resin particles having a particle size of about 0.1 μm. Further, 30 g of Snowtex C (manufactured by Nissan Chemical Industries, Ltd.) was added to the resin particle dispersion to hetero-aggregate silica sol fine particles on the surface of the resin particles. The core was a resin, and the shell was 0.15 μm in diameter of a silica layer. A composite particle 1 having a hetero-aggregated hydrophilic surface layer was prepared.

<Precursor B: Composite particles 2 of hetero-aggregated surface layer> 60 g of styrene, 10 g of divinylbenzene, 30 g of trimethoxysilylpropyl methacrylate, 200 g of water
g, surfactant XL-102F (manufactured by Lion Corporation)
10 g of a (4.7% aqueous solution) is placed in a three-necked flask, and the temperature is raised to 80 ° C. while introducing nitrogen. Thereafter, after stirring for about 30 minutes, 1 g of K ₂ S ₂ O ₈ was added, and emulsion polymerization was carried out at 80 ° C. for 6 hours to obtain resin particles having a particle size of about 0.2 μm.
Further, 30 g of Snowtex C (manufactured by Nissan Chemical Industries, Ltd.) was added to the resin particle dispersion to hetero-aggregate silica sol fine particles on the surface of the resin particles. The core was a resin, and the shell was 0.25 μm in diameter of a silica layer. The composite particle 2 of the hetero-aggregated hydrophilic surface layer was prepared.

<Precursor C: Composite Particle 3 of Hetero-aggregated Surface Layer> 70 g of styrene, 30 g of trimethoxysilylpropyl methacrylate, 200 g of water, surfactant XL-10
10 g of 2F (manufactured by Lion Corporation) (4.7% aqueous solution) was placed in a three-necked flask, and heated to 80 ° C. while introducing nitrogen. After stirring for about 30 minutes, 1 g of K ₂ S ₂ O ₈ was added.
Add emulsion polymerization at 80 ° C. for 6 hours.
1 μm resin particles were obtained. Further, 30 g of alumina sol (manufactured by Nissan Chemical Industries, Ltd.) was added to the resin particle dispersion,
Hetero-aggregation of alumina sol fine particles on the resin particle surface,
A composite particle 3 having a hetero-aggregated hydrophilic surface layer having a core of resin and a shell of alumina having a particle size of 0.15 μm was prepared.

<Precursor D: Composite Particle 1 of Surface Heterophase>
70 g of styrene, 30 g of trimethoxysilylpropyl methacrylate, 200 g of water, surfactant XL-102F
10 g of a 4.7% aqueous solution (manufactured by Lion Corporation) was placed in a three-necked flask, and heated to 80 ° C. while introducing nitrogen. Thereafter, after stirring for about 30 minutes, 1 g of K ₂ S ₂ O ₈ was added and emulsion polymerization was carried out at 80 ° C. for 6 hours to obtain resin particles having a particle size of about 0.1 μm. Further, 30 g of tetraethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the resin particle dispersion,
A sol-gel reaction was carried out at room temperature to prepare a composite particle 1 of a hydrophilic gel surface layer having a resin layer having a core and a silica layer having a particle diameter of 0.15 μm, wherein the resin particle surface was coated with silica.

<Precursor E: Composite Particle 2 of Surface Heterophase>
60 g of styrene, 10 g of divinylbenze, 30 g of hydroxyethyl methacrylate, 200 g of water, surfactant X
L-102F (manufactured by Lion Corporation) (4.7% aqueous solution)
Put 10 g in a three-necked flask and introduce nitrogen,
The temperature was raised to 80 ° C. Then, after stirring for about 30 minutes, K ₂ S ₂ O
₈ was subjected to the addition by emulsion polymerization 1g, particle size of about 0.2μm
Resin particles were obtained. Further, 30 g of tetraethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the resin particle dispersion, and a sol-gel reaction was carried out at room temperature to coat the resin particle surface with silica. Composite particles 2 having a hydrophilic gel surface layer of 0.25 μm were prepared.

<Precursor F: core-shell particles 1> 80 g of styrene, 10 g of divinylbenzene, macromonomer AA
-6 (dispersing agent, manufactured by Toagosei Co., Ltd.) 10 g, MEK40
0 g is placed in a three-necked flask, and nitrogen is introduced.
The temperature was raised to 5 ° C. Thereafter, after stirring for about 30 minutes, 2 g of azoisobutyronitrile was added, and dispersion polymerization was performed at 75 ° C. for 6 hours to obtain resin particles having a particle size of 0.2 μm. Further, the resin particle dispersion was heated to 75 ° C. while introducing nitrogen, stirred for about 30 minutes, and then 35 g of acrylamide, 4 g of methylenebisacrylamide, and 1 g of azoisobutyronitrile were added in 10 g.
0 g of MEK, added dropwise over about 2 hours, and then subjected to seed dispersion polymerization for 3 hours.
Was crosslinked with styrene to form core-shell particles 6 having an acrylamide shell.

<Precursor G: core-shell particles 2> 80 g of styrene, 10 g of divinylbenzene, macromonomer AA
-6 (dispersing agent, manufactured by Toagosei Co., Ltd.) 10 g, MEK40
0 g is placed in a three-necked flask, and nitrogen is introduced.
The temperature was raised to 5 ° C. Thereafter, after stirring for about 30 minutes, 2 g of azoisobutyronitrile was added, and dispersion polymerization was performed at 75 ° C. for 6 hours to obtain resin particles having a particle size of 0.2 μm. Further, the resin particle dispersion was heated to 75 ° C. while introducing nitrogen, stirred for about 30 minutes, and then 35 g of acrylic acid, 4 g of ethylene glycol diacrylate, and 1 g of azoisobutyronitrile were added to 1 g of the resin particle dispersion.
Dissolved in 00 g of MEK, added dropwise over about 2 hours, and then subjected to seed dispersion polymerization for 3 hours to obtain a particle size of 0.3 μm.
m was crosslinked with styrene to form core-shell particles 7 having an acrylamide shell. By adjusting the pH to 10 or more using sodium hydroxide, core-shell particles in which the carboxyl group of acrylic acid was converted to a sodium salt were prepared.

<Precursor H: Microcapsule Particles 1> 19.0 parts (all parts by weight) of ethyl acetate, 5.9 parts of isopropyl biphenyl, 5 parts of glycerol laurate and 2.5 parts of tricresyl phosphate were heated. And evenly mixed. 7.6 parts of a xylylene diisocyanate / trimethylolpropane adduct (75% ethyl acetate solution Takenate D110N: trade name of Takeda Pharmaceutical Co.) as a capsule wall material (also a precursor of hydrophobization) is added to this solution. Further, it was added and stirred uniformly. Separately, 2.0 parts of a 10% by weight aqueous solution of sodium dodecyl sulfonate was added.
64 parts by weight of an aqueous solution of gelatin (MGP-9066: trade name of Nippi Gelatin Industries Co., Ltd.) was prepared and emulsified and dispersed by a homogenizer.

After 20 parts of water was added to the obtained emulsion to homogenize it, the temperature was raised to 40 ° C. with stirring, and an encapsulation reaction was carried out for 3 hours. Thereafter, the temperature of the solution was lowered to 35 ° C., and the ion-exchange resin Amberlite IRA68 (manufactured by Organo) was used.
5 parts, Amberlite IRC50 (Organo) 13
And stirred for an additional hour. Thereafter, the ion exchange resin was filtered to obtain a desired capsule liquid. The average particle size of the capsule was 0.64 μm. Microcapsule particles 1 were obtained.

<Precursor I: Reactive composite particles 1 of hetero-aggregated surface layer> 2.0 g of glycidyl methacrylate, 13.0 g of methyl methacrylate, aqueous solution of polyoxyethylene phenol (concentration: 9.8 × 10 ⁻³ mol / l) 2
After adding 00 ml and stirring at 250 rpm, the inside of the system is replaced with nitrogen gas. After the temperature of the solution was raised to 25 ° C., an aqueous cerium (IV) ammonium salt solution (concentration: 0.984 × 1
0 ^-3 mol / l). At this time, an aqueous solution of ammonium nitrate (concentration: 58.8 × 10 ⁻³ mol / l) is added to adjust the pH to 1.3 to 1.4. It was then stirred for 8 hours. The solid content of the liquid thus obtained was 9.5%, and the average particle size was 0.4 μm. Further, 30 g of Snowtex C (manufactured by Nissan Chemical Industries, Ltd.) was added to the resin particle dispersion to hetero-aggregate silica sol fine particles on the surface of the resin particles. The core was a resin, and the shell was 0.5 μm in particle diameter of a silica layer. The hydrophobized precursor I (reactive composite particle 1) having the hetero-aggregated hydrophilic surface layer was prepared.

<Precursor J: Reactive Composite Particles 2 of Hetero-aggregated Surface Layer> 7.5 g of allyl methacrylate and 7.5 g of styrene were polymerized in the same manner. The solid content of the liquid thus obtained was 9.5%, and the average particle size was 0.1%.
It was 4 μm. Further, 30 g of Snowtex C (manufactured by Nissan Chemical Industries, Ltd.) was added to the resin particle dispersion to hetero-aggregate silica sol fine particles on the surface of the resin particles. The core was a resin, and the shell was 0.45 μm in particle diameter of a silica layer. To prepare a hydrophobized precursor J (reactive composite particles 2) having a hetero-aggregated hydrophilic surface layer.

<Precursor K: Reactive Microcapsule Particle 1> Xylene diisocyanate 40 was used as an oil phase component.
g, 10 g of trimethylolpropane diacrylate, 10 g of a copolymer of allyl methacrylate and butyl methacrylate (7/3 molar ratio), and 0.1 g of Pionin A41C (manufactured by Takemoto Yushi) were dissolved in 60 g of ethyl acetate. As an aqueous phase component, 1% of a 4% aqueous solution of PVA205 (manufactured by Kuraray) was used.
20 g were produced. The oil phase component and the aqueous phase component were emulsified at 10,000 rpm using a homogenizer. Then add 4 water
0 g was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The microcapsule solution thus obtained had a solid content of 20% and an average particle size of 0.5 μm. Further, Snowtex C is contained in the resin particle dispersion.
Addition of 30 g (manufactured by Nissan Chemical Co., Ltd.) to hetero-aggregate silica sol fine particles on the surface of resin particles. Hydrophobization with a hetero-aggregated hydrophilic surface layer having a core of resin and a shell of silica layer having a particle diameter of 0.6 μm. Precursor K (reactive microcapsule particles 1) was prepared.

<Hydrophobic resin dispersion 1 for Comparative Example 1> 80 g of styrene, 10 g of divinylbenzene, macromonomer A
A-6 (dispersant, manufactured by Toagosei Co., Ltd.) 10 g, MEK4
00g in a three-necked flask, while introducing nitrogen,
The temperature was raised to 75 ° C. After stirring for about 30 minutes, 2 g of azoisobutyronitrile was added, and dispersion polymerization was performed at 75 ° C. for 6 hours to obtain resin particles having an average particle diameter of 0.2 μm.

<Hydrophilic Resin Dispersion 1 for Comparative Example 2> A dispersion of dispersed polymer particles of polyvinylpyrrolidone (average particle size 0.2
μm) was used.

(3) Preparation of photothermal conversion agent Iron oxide, copper oxide,
Manganese oxide, metallic iron, titanium black and carbon black fine particles were used as photothermal conversion solid particles.
The method for making the surface hydrophilic was in accordance with the method described above for the photothermal conversion agent. After adding hydroxyl groups to the surface of the carbon black by steam treatment as described above, a surface silica film was formed with tetraethoxysilane. Also,
In titanium black, the particles themselves are hydrophilic. further,
The exemplary compound (1) was used as a hydrophilic IR dye.

<Preparation of Photothermal Conversion Agents for Comparative Examples 3 and 4 and Comparative Example 5> For Comparative Example 3, the above-mentioned carbon black fine particles which were not subjected to a surface hydrophilic treatment were used. For Comparative Example 4, a pigment having a bisindolenine structure represented by the following chemical formula, which is a hydrophobic infrared absorbing dye, was dispersed and used. In Comparative Example 5, a coating solution was prepared without adding a photothermal conversion agent.

[0201]

Embedded image

(4) Coating of Image Recording Layer <Preparation of Tetramethoxysilane Dispersion> A dispersion of the following formulation (A) containing tetramethoxysilane as a sol-gel converting component (referred to as sol-gel liquid (A)) ) Was prepared. As a preparation method, silicon tetramethoxide, ethanol, pure water, and nitric acid were mixed in this order, and stirred at room temperature for 1 hour to prepare a sol-gel liquid (A). Sol-gel liquid (A) formulation Silicon tetramethoxide 18.37 g Ethanol (95%) 32.56 g Pure water 32.56 g Nitric acid 0.02 g

<Preparation of Coating Solution for Image Recording Layer> Coating Solution for Examples 1 to 17 and Comparative Examples 1 to 5 The above sol-gel solution (A) was used as a coating solution for the image recording layer, as shown in Table 1. A total of 22 types of dispersion liquids of Examples 1 to 17 and Comparative Examples 1 to 5 were prepared by changing the types of the photothermal conversion agent and the hydrophobizing precursor. For the preparation, 10 g of glass beads were added to a mixture containing each component as shown below, and the mixture was stirred with a paint shaker for 10 minutes to obtain a dispersion. Formulation of coating solution for image recording layer Photothermal conversion agent (see Table 1) 2.17 g Hydrophobizing precursor (see Table 1) 2.17 g Sol-gel solution (A) 3.34 g PVA117 (10% aqueous solution) 3.50 g Colloidal silica R503 (20% aqueous solution) 6.0 g Pure water 7.49 g

<Coating> The coating solution for the image recording layer was applied to bar # 14.
The resultant was coated on the aluminum substrate by a bar coater so as to have a dry thickness of 2.0 μm, and then dried in an air oven at 100 ° C. for 10 minutes to form an image recording layer.

(5) Preparation of printing plate <Preparation and printing of printing plate> Each of the obtained lithographic printing original plates was irradiated with a semiconductor laser beam having a wavelength of 830 nm. Specific laser irradiation conditions are shown below. Laser output: 350 mW Beam radius: 12.5 μm Scanning speed: 1.7 m / sec Output: 700 mJ / cm ²

The original plate exposed to laser was printed on a printing machine without any post-processing. 100 printed sheets
At the time of 00 sheets and 20000 sheets, the degree of print smear was inspected silently. The printing press used was Heidelberg SOR-
M was used as the dampening solution, and an aqueous solution obtained by adding 1 vol% of EU-3 (manufactured by Fuji Photo Film Co., Ltd.) and 10 vol% of IPA to the water was used, and GEOS (N) black was used as the ink. .

(6) Evaluation of printing original plate and evaluation method The finished printing original plate was evaluated as follows. <Evaluation method of print stain> The print stain on the printed paper surface after printing 10,000 sheets was inspected by visual inspection. In the case where there was no print stain, 10,000 sheets were further printed, and the case where the print stain on the printing paper surface was not continuously generated was indicated by ◎. The results are shown in Table 1.

[0208]

[Table 1]

(Note) Notes on Table 1 below. 1. TiO _x (x = 1.0 to 1.1) is commercially available titanium black. Hydrophilic. 2. The print quality was evaluated as “x” even when there was no print smear and no print was made. 3. The precursors A to H are as described below (as described in the text). Precursor A: Composite particle 1 of hetero-aggregated surface layer Precursor B: Composite particle 2 of hetero-aggregated surface layer Precursor C: Composite particle 3 of hetero-aggregated surface layer Precursor D: Composite particle 1 of surface hetero-phase Precursor E : Composite particle 2 of surface hetero phase Precursor F: Core-shell particle 1 Precursor G: Core-shell particle 2 Precursor H: Microcapsule particle 1 Precursor I: Reactive composite particle 1 of hetero-aggregated surface layer Precursor J: Hetero-aggregation Surface layer reactive composite particles 2 Precursor K: reactive microcapsule particles 1

(7) Results As shown in Table 1, the composite compositions of Examples 1 to 11 of the present invention in which the hetero-aggregation, heterogel phase formation, and hydrophilic shell resin layer or microcapsule wall material were used as the hydrophilic surface layer The samples to which the hydrophobized precursor particles were added did not have print stains even after printing 10,000 sheets or more, and especially core-shell type resin particles having a hydrophilic phase on the surface and a hydrophobic core on the core. Examples 4 and 5 showed no printing stains even after printing 20,000 sheets, indicating that they had excellent printing durability. On the other hand, in Comparative Example 1 in which the polystyrene particles were used without performing the surface hydrophilicity treatment, printing stains occurred in the non-image area. In Comparative Example 2 using polyvinylpyrrolidone particles, which are hydrophilic particles, no ink was attached to the image area, and no printing was performed (X in the evaluation column of Table 1 is X for no printing). Various light-to-heat conversions in which the material of the light-to-heat conversion agent is different from that of iron oxide, metallic iron, carbon black, titanium black, manganese oxide, copper oxide, hydrophilic dye, etc. Each of the samples of Examples 12 to 17 of the present invention using each of the agents showed no printing stains even after printing 10,000 sheets or more, and exhibited excellent printing durability. On the other hand, in Comparative Examples 3 and 4 in which the carbon black fine particles or the hydrophobic infrared-absorbing dye was used without performing the surface hydrophilicity treatment, printing stains occurred in the non-image area. In Comparative Example 5 in which no light-to-heat conversion agent was used, no ink was attached to the image area, and no printing was performed (x in the evaluation column of Table 1 is x for not printing).

[0211]

According to the present invention, a printing plate having an image recording layer in which a photothermal conversion agent having a hydrophilic property or a hydrophilic surface and a hydrophobizing precursor having a hydrophilic surface are dispersed in a hydrophilic medium has an image area. The non-image area has high discrimination ability, has excellent printing durability, and has excellent printing performance in which printing smear is hardly generated. According to the present invention, in particular, by recording using a solid-state laser or semiconductor laser that emits infrared rays,
It is possible to provide a lithographic printing plate precursor that can be directly made from digital data.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shunsaku Higashi 200 Nakanakazato, Fujinomiya City, Shizuoka Prefecture Inside Fuji Photo Film Co., Ltd. F term (reference) 2H025 AA12 AB03 AC08 AD01 AD03 BH03 CB33 CC20 DA02 FA10 2H096 AA07 AA08 BA16 BA20 CA20 EA02 EA04 2H114 AA04 AA23 AA24 AA27 BA01 BA10 DA05 DA15 DA22 DA25 DA28 DA74 EA01 EA03 FA04

Claims (6)

[Claims] 1. A layer comprising a hydrophilic medium provided on a support, characterized in that the layer comprises a hydrophobizing precursor having a hydrophilic surface and a photothermal conversion agent itself or at least a surface having a hydrophilic property. Lithographic printing plate. 2. The lithographic printing plate according to claim 1, wherein the layer made of a hydrophilic medium has a sol-gel conversion property. 3. The hydrophobizing precursor having a hydrophilic surface is a composite particle dispersion having a hydrophobic substance in the core and a surface layer having a hydrophilic surface. Item 3. An original plate for lithographic printing according to item 1 or 2. 4. The method according to claim 1, wherein the photothermal conversion agent is a solid fine particle selected from a metal, a metal compound, a pigment and a simple carbon having a hydrophilic surface, or a hydrophilic dye soluble in a hydrophilic medium. Item 4. The lithographic printing plate according to any one of items 1 to 3. 5. The lithographic printing plate according to claim 1, wherein a water-soluble protective layer is provided on the surface. 6. After irradiating the lithographic printing plate according to any one of claims 1 to 5 imagewise with visible light or infrared light having photothermal conversion property, the irradiated surface is brought into contact with ink to form an image. A lithographic printing method characterized in that printing is performed by forming a printing plate surface that has accepted the above.