JP2004299385A - Support for offset-printing form and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support for offset printing form used for an original offset-printing form which is excellent in the sensitivity and print wear as the form, while being superior in the stain resistance as well as the shiny nature (nature of the form surface hardly shining in mounting the offset printing forme on a printing machine) and its manufacturing method, and the support for offset printing form having these characteristics and capable of reducing the manufacturing cost. <P>SOLUTION: The support has a porous layer formed by binding metal oxide particles with the compound, including a metal atom and phosphorous atom, on a substrate.The support has also an intermediate layer, including the composition containing alumina particles, particles with high void-ratio, phosphoric acid and aluminum compound as the principal component, on the substrate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a support for a lithographic printing plate and a method for producing the same, and in particular, can be made by scanning exposure based on a digital signal and has scratch resistance equal to or higher than that of a support for a lithographic printing plate provided with an anodized film. The present invention relates to a lithographic printing plate support having excellent sensitivity, stain resistance, shinyness and printing durability, and a method for producing the same.
Furthermore, in addition to the said characteristic, it is related with the support body for lithographic printing plates which can reduce manufacturing cost, and its manufacturing method.

  In the field of lithographic printing, a metal substrate is widely used as a substrate for a lithographic printing plate support used in a lithographic printing plate precursor for producing a lithographic printing plate. Among them, aluminum is known to generate an oxide film by flowing direct current electricity as an anode in an acidic solution, and can be processed generally known as an alumite treatment, and is also lightweight and inexpensive. Has the advantage of When alumite treatment is applied to the aluminum surface, the alumina oxide film has higher acid resistance and hardness than metal aluminum, and a large number of pores called pores are regularly formed in the film structure. The BET method (gas adsorption method) Since the surface area due to the alumite significantly increases, the alumite treatment can improve the hydrophilicity of the lithographic printing plate support, and can improve the adhesion force when forming the coating film. In addition, it has an advantage that both excellent stain resistance (referred to as “soil resistance” in the present invention) and printing durability when used as a lithographic printing plate can be achieved.

In recent years, images can be formed by exposure in the near-infrared to infrared regions, and in particular, by recording images using heat generated during light irradiation using a laser having a light-emitting region in the region. A so-called heat mode type CTP lithographic printing plate precursor (hereinafter also simply referred to as “heat mode type lithographic printing plate precursor”), which can be directly made from digital data of a computer or the like, has attracted attention.
In this lithographic printing plate precursor, the irradiation laser light for drawing is converted into heat by a photothermal conversion material contained in the photosensitive layer, and the generated heat changes the solubility of the photosensitive layer in the developer, or the photosensitive layer is changed. Explosive expansion removal (ablation) is performed by pyrolysis or rapid heating. When aluminum is used as a support for these heat mode type lithographic printing plate precursors, the heat generated by the aluminum is rapidly dissipated to the support because the heat conductivity of the aluminum is high. This is one of the causes of the loss of sensitivity of the lithographic printing plate precursor. In other words, the sensitivity of the lithographic printing plate precursor can be improved if the heat insulation of the surface of the lithographic printing plate support is improved and the heat dissipation phenomenon generated in the photosensitive layer can be minimized. Expected to be

On the other hand, a method of increasing sensitivity by using an organic material having low thermal conductivity such as PET as a support has also been attempted, but its hydrophilicity is lower than that of a metal material, and moisture is absorbed during printing. Since the accuracy deteriorates, it cannot be used for advanced printing such as color printing and high-definition printing.
Therefore, as a support used in the heat mode type lithographic printing plate precursor, low heat insulation due to the high thermal conductivity of aluminum while taking advantage of the convenience of various surface treatments of aluminum, hydrophilicity, dimensional accuracy stability, etc. There is a need to improve performance.

As a means for improving the low thermal insulation of the aluminum support, the film thickness of the anodized film can be adjusted by utilizing the property that the thermal conductivity of the anodized film itself formed on the lithographic printing plate support is low. A method of increasing the thickness, a method of increasing the porosity of the coating by immersing it in an acid aqueous solution or an alkaline aqueous solution after forming the anodized coating, increasing the pore diameter in the coating, and the like have been proposed.
However, when the thickness of the anodic oxide film is increased, a large amount of electricity is required to form the anodic oxide film, which causes a cost increase. Further, in the method of increasing the porosity of the coating, the strength of the coating is reduced, so that if the coating is scratched, ink enters the scratch and causes stains. That is, in the method of providing an anodized film, although it is excellent in heat insulation and can improve low sensitivity, it cannot obtain sufficient film strength that causes cost increase and dirt, and it is difficult to achieve both film strength and heat insulation. There's a problem.

Further, for example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-318458), by controlling the anodizing treatment conditions of the aluminum plate, increasing the pore diameter of the oxide film micropore after the anodizing step, sealing treatment, etc. A technique is described in which an anodic oxide film having a predetermined porosity and micropores having a predetermined diameter is formed to improve the heat insulation of the surface of the support to increase the sensitivity of the heat mode lithographic printing plate.
Furthermore, in Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-2133), in a heat-sensitive lithographic printing plate, heat insulation is improved by providing a hydrophilic layer containing hollow particles between a support and a heat-sensitive layer. It is described that the sensitivity can be increased.

  However, the technology for improving the heat insulating property of the support of the above-described heat-sensitive lithographic printing plate increases the manufacturing cost because it requires an extra amount of electricity and the process becomes complicated because the oxide film is thick. There was a problem.

On the other hand, as a film that replaces the anodic oxide film formed on the lithographic printing plate support, for example, it has a hydrophilic layer containing alumina particles, and the hydrophilic layer is treated with a liquid containing silicic acid. A hydrophilic layer for lithographic printing plates characterized by this is proposed (see Patent Document 3). A step of applying a slurry containing at least inorganic non-metallic particles and a monobasic phosphate on a substrate having an aluminum surface and sufficiently dehydrating and drying at a temperature of at least 230 ° C. to form a hydrophilic ceramic layer; There has been proposed a method for producing a photosensitive material including a step of forming an organic photosensitive layer on the hydrophilic ceramic layer (see Patent Document 4).
However, the hydrophilic layer for a lithographic printing plate is a layer formed by utilizing the self-forming property of alumina sol, and the film strength is also weak. Therefore, the hydrophilic layer and the lithographic printing plate support provided with the hydrophilic layer are inferior in scratch resistance, and may be inferior in printing durability when used as a lithographic printing plate. On the other hand, the lithographic printing plate provided with the hydrophilic ceramic layer may not be able to obtain sufficiently satisfactory stain resistance. Moreover, the said hydrophilic ceramic layer performs the drying process at the high temperature over 230 degreeC, and the drying installation which enables such high temperature drying is generally expensive. Furthermore, if it is dried at an excessively high temperature (for example, 260 ° C. or higher), the aluminum plate provided with the hydrophilic ceramic layer is softened, and the excellent dimensional accuracy stability of the aluminum plate is impaired. There is a case where the substrate is not aligned with the image due to elongation.

  Further, the lithographic printing plate support provided with the lithographic printing plate hydrophilic layer and the lithographic printing plate support provided with the hydrophilic ceramic layer are used as a lithographic printing plate in mass printing having a large number of copies. In many cases, it is inferior in printing durability and stain resistance, and improvement in printing performance is desired.

In general, in printing using a lithographic printing plate, it is necessary to adjust the amount of dampening water (water amount) during printing. However, if there is too much light reflection on the plate surface, Since adjustment becomes difficult, the case where dirt occurs may occur. Therefore, it is necessary to suppress light reflection to a certain extent on the surface of the lithographic printing plate support, which is a non-image portion of the lithographic printing plate.
However, in the above two lithographic printing plate supports, the amount of reflected light increases, and the plate surface may shine when mounted on a printing machine even with a small amount of water. Such a phenomenon is called “shiny”, and is an undesirable phenomenon in terms of confirming the adjustment of the amount of water (plate inspection), and improvement is also desired.
JP 2001-318458 A JP 2002-2133 A JP 2000-169758 A US Pat. No. 4,542,089

The present invention overcomes the drawbacks of the above-described technology, has a film having scratch resistance equal to or better than that of an anodic oxide film, sensitivity when used as a lithographic printing plate, and stain resistance when used as a lithographic printing plate An object of the present invention is to provide a support for a lithographic printing plate which is excellent in both properties and printing durability, and a lithographic printing plate precursor using the same.
Another purpose is to have excellent sensitivity, printing durability, stain resistance, and shinyness when using a lithographic printing plate (a property that makes the plate surface difficult to shine when the lithographic printing plate is mounted on a printing press). Another object of the present invention is to provide a lithographic printing plate support for use in an excellent lithographic printing plate precursor and a method for producing the same.
Furthermore, it aims at providing the support body for lithographic printing plates which has these characteristics and can reduce manufacturing cost.

As a result of intensive studies, the inventors of the present invention can form a porous layer in which a suitable amount of air is taken in by binding metal oxide particles with a compound containing metal atoms and phosphorus atoms on the substrate. It is found that the porous layer has excellent heat insulation and strong film strength, and the lithographic printing plate support provided with the porous layer is equivalent to the lithographic printing plate support provided with the anodic oxide film. It has been found that it exhibits the above sensitivity, excellent stain resistance and printing durability. Furthermore, by making the surface roughness of the lithographic printing support provided with the porous layer within a predetermined range, the porous layer has high heat insulating properties, excellent scratch resistance, printing durability and stain resistance. It was found that the printing durability and the shiny property can be improved to a higher level without damage.
In addition, the present inventors have found an efficient method for producing a lithographic printing plate support having the surface roughness.
That is, this invention is made | formed based on the said knowledge, and provides the following (1)-(7).

(1) A lithographic printing plate support having a porous layer formed by binding metal oxide particles with a compound containing metal atoms and phosphorus atoms on a substrate.
(2) The lithographic printing plate support according to (1), wherein the metal oxide is an oxide or composite oxide of at least one metal selected from the group consisting of silicon, magnesium, zirconium and titanium. .
(3) The lithographic printing plate support according to (1) or (2), wherein a sealing layer is provided on the porous layer.
(4) The film thickness of the porous layer is 0.5 to 20 μm, the film thickness of the sealing layer is 0.01 to 0.5 μm, and the surface roughness Ra is 0.3 to 2.0 μm. The support for a lithographic printing plate as described in (3).
(5) A lithographic printing plate support comprising an intermediate layer formed of a composition containing alumina particles, high void particles, phosphoric acid, and an aluminum compound as main components on a substrate.
(6) The lithographic plate according to (1), (2) or (5), wherein the substrate is an aluminum plate, aluminum laminated paper, aluminum laminated resin, or aluminum coated metal Support for printing plate.
(7) A substrate is roughened, and a porous layer formed by binding metal oxide particles with a compound containing a metal atom and a phosphorus atom is provided on the roughened substrate, A method for producing a support for a lithographic printing plate, wherein a sealing layer is provided on the porous layer.

  In the present invention, the sensitivity is the sensitivity when a lithographic printing plate precursor is used, and the stain resistance, printing durability and shiny property are stain resistance and printing durability when a lithographic printing plate is used. Sexual and shiny.

  According to the present invention, plate making by scanning exposure based on a digital signal is possible, and scratch resistance, excellent sensitivity, stain resistance, and shininess equivalent to or higher than those of a lithographic printing plate support provided with an anodized film are provided. Further, it is possible to provide a support for a lithographic printing plate and a method for producing the same, which have the properties and the printing durability, and can reduce the production cost in addition to the above properties.

  Hereinafter, the lithographic printing plate support and the lithographic printing plate precursor according to the invention will be described in detail.

The present invention is described in detail below.
[Support for lithographic printing plate]
<Porous layer>
The lithographic printing plate support of the present invention has a porous layer (hereinafter referred to as “the porous layer of the present invention”) in which metal oxide particles are bound by a compound containing a metal atom and a phosphorus atom on a substrate. .).

The porous layer of the present invention provided on a substrate is a layer in which a large number of metal oxide particles are bonded via a compound containing a metal atom and a phosphorus atom. The surface is partially, preferably entirely, covered with the compound containing the metal atom and the phosphorus atom, the compound containing the metal atom and the phosphorus atom is solidified, and a plurality of metal oxide particles covered therewith aggregate. In this state, it is considered that the layer is formed by binding via a compound containing the metal atom and phosphorus atom.
A void portion is formed between the plurality of bound particles, and this void can take in air, and the porosity of the porous layer is increased to improve the heat insulation. In addition, since the binder is bound via a compound containing the metal atom and phosphorus atom, the porous layer has high film strength, excellent scratch resistance, and excellent printing durability.

The bound metal oxide particles that form the porous layer are metal oxide particles that remain after reacting with a phosphoric acid compound (part of the surface) of the metal oxide, which will be described later. It is considered that the particle size remains without being greatly reduced.
That is, one of the features of the present invention is to dissolve the surface of the metal oxide particles (not to dissolve the whole).
Examples of the method for dissolving the surface include conditions (temperature, pH, etc.) in which the reaction between the metal oxide particles and the phosphoric acid compound hardly occurs in the state of a coating liquid (slurry) described later. Examples include a method in which the pH is lowered during application of the coating liquid or during drying, and the conditions are such that the reaction takes place at a high temperature.
Specifically, a method for specifying the drying temperature in the drying step described later (preferably a method for further specifying the drying time), a method for determining the amount of the metal oxide that reacts with the phosphoric acid compound described later, catalyst / reaction Examples thereof include a method of adding an accelerator and the like, a method of appropriately combining these, and the like.
The average particle diameter and the like of the metal oxide particles forming the porous layer are not particularly limited, and differ depending on the particle diameter of the metal oxide used in the coating solution described later.
The metal oxide and its particles are basically the same as those described in the coating liquid described later.

The compound containing a metal atom and a phosphorus atom forming the porous layer is a reaction product of a phosphoric acid compound and a metal oxide described later or a reaction product of the phosphoric acid compound and a reaction accelerator described later. Yes, it functions as a binder that binds the metal oxide particles together.
Since the compound differs depending on the metal oxide, phosphoric acid compound and reaction accelerator used arbitrarily, it cannot be determined unconditionally, but may contain other atoms such as oxygen atoms. Examples of the compound include Mg ₂ P ₂ O ₇ and Mg ₃ (PO) ₄ when MgO is used as the metal oxide. Other examples include “Chemical”, Japan Chemical Association, Vol. 31, No. 11, p. 895-897.

The compound containing a metal atom and a phosphorus atom is not limited to the above compound, and may be a compound having a “bonding group containing a metal atom and a phosphorus atom” that bonds metal oxide particles to each other. The linking group may have a high molecular weight.
The composition of the compound containing a metal atom and a phosphorus atom and the bonding group containing a metal atom and a phosphorus atom are not particularly limited.

For the formation of the porous layer of the present invention, as described later, a reaction accelerator containing a metal atom different from the metal atom of the metal oxide can be used. Therefore, the metal atom in the compound containing the metal atom and the phosphorus atom may be a metal atom derived from the reaction accelerator.
Preferably, the metal atom of the compound containing a metal atom and a phosphorus atom is the same metal atom as the metal atom of the metal oxide, and more preferably a metal atom derived from the metal oxide.

  In the porous layer, the abundance ratio between the metal oxide particles and the compound containing a metal atom and a phosphorus atom is not particularly limited, and the amount of the compound containing the metal atom and the phosphorus atom is at least the metal oxide. More than the amount that can bind these particles and less than the amount that completely fills the voids between the particles, for example, determined by the composition of the coating liquid described later.

The porous layer of the present invention may contain other compounds in addition to the above-described compound containing metal oxide particles, metal atoms, and phosphorus atoms.
Examples of the other compound include a dispersant, a reaction accelerator, and the like, which will be described later, and reaction production of these with the above metal oxide or a compound containing a metal atom and a phosphorus atom.

The porous layer of the present invention preferably has a porosity of 20% or more, more preferably 40% or more, and further preferably 45% or more. When the porosity is 20% or more, since a suitable amount of air can be taken into the porous layer, heat insulation is excellent and sensitivity is increased.
Further, it is preferably 70% or less, more preferably 60% or less, from the viewpoint of excellent printing durability while maintaining the strong film strength of the porous layer.

The method for measuring the porosity of the porous layer is determined from the film thickness of the porous layer described later and the mass of the porous layer after drying.
Specifically, first, the density of the porous layer is calculated by the following formula. For this, the mass after drying of the porous layer is measured to determine the coating mass per unit area, and the film thickness of the porous layer is measured by the method described later.
Density (g / cm ³ ) = (film mass per unit area / film thickness)
Next, the porosity of the porous layer is determined by the following formula based on the density calculated above.
Porosity (%) = {1− (density of porous layer / D)} × 100
Here, D is the density (g / cm ³ ) according to the chemical handbook of the metal oxide used for forming the porous layer.

The porous layer of the present invention preferably has a film thickness of 0.5 to 20 μm, more preferably 1 to 10 μm, and further preferably 3 to 7 μm. When the film thickness is 0.5 μm or more, the film strength of the porous layer is strong and excellent in scratch resistance and printing durability, and the heat insulating property of the porous layer is high and the sensitivity is excellent.
The upper limit of the film thickness is 20 μm for cost reasons because no further effect can be obtained, but is not limited to this and may be 20 μm or more.

The method for measuring the film thickness of the porous layer is as follows. First, a fracture surface prepared by bending a lithographic printing plate support provided with the porous layer was subjected to ultra high resolution scanning electron microscope (for example, S-900, Observe and shoot with Hitachi, Ltd. Note that the observation magnification is appropriately adjusted depending on the film thickness and the like. Specifically, the magnification is preferably 100 to 10,000 times.
Next, the thickness of the porous layer portion of the obtained image data (photograph) can be measured and converted.

The porous layer of the present invention may be a single layer or a plurality of layers in which two or more layers are superimposed.
In the case of a plurality of layers, the same porous layer may be overlapped, or porous layers having different compositions may be overlapped. The thickness of each layer is also not particularly limited, and the thickness of each layer may be constant or may be different.
In order to form a plurality of layers, for example, a coating process for coating a coating liquid described later and a drying process for drying the coating liquid may be repeated alternately.

The porous layer is, for example, a coating step in which a coating solution containing a granular metal oxide and a phosphoric acid compound is coated on a substrate, and drying by heating and drying the coating solution coated on the substrate at 180 to 500 ° C. It can form on a board | substrate by the method including a process.
That is, the lithographic printing plate support of the present invention is obtained by applying a coating liquid containing a particulate metal oxide and a phosphoric acid compound to a substrate and drying the coating liquid at 180 to 500 ° C. A lithographic printing plate support having a quality layer on the substrate.

Although the reaction mechanism by which the porous layer is formed is not known in detail, the present inventors consider as follows. A description will be given by taking magnesia (MgO) as an example.
The reaction between magnesia and phosphoric acid is considered to occur by the following formulas (1) and (2), and the metal oxide particles are bound by the generated Mg ₂ P ₂ O ₇ or the like. In addition, when completely dried the coating solution, MgHPO ₄ generated in Equation (1) is also considered that when functioning as a binder.

That is, when the pH of the coating liquid containing the granular metal oxide and the phosphoric acid compound is within a preferable range described later, the surface of the metal oxide particles is slightly dissolved under the acidic condition, Both the dissolved metal oxide and the eluted metal oxide easily react with the phosphate compound. Under the acidic conditions, the surface of the substrate also reacts with the phosphoric acid compound and is activated.
After application of the coating solution, preferably in a drying step, the water of the coating solution is removed, the concentration of the phosphoric acid compound is increased, and the temperature of the coating solution and the substrate is increased. Then, the substrate, the metal oxide whose surface is dissolved, and the eluted metal oxide react with the phosphoric acid compound, and gradually form a compound containing a metal atom and a phosphorus atom which are hardly soluble in water. This water-insoluble compound functions as a binder that binds the metal oxide particles together, forming a porous layer that incorporates a suitable amount of air, with multiple metal oxide particles bound together. Is done.
The porous layer bound with a compound that is hardly soluble in water is excellent in heat insulation because it takes in a suitable amount of air, and the film strength of the porous layer because it is bound by the compound Becomes stronger.

In such a mechanism, it is considered that when a reaction accelerator is used, the above-described reaction occurs at a lower temperature, and Mg ₂ P ₂ O ₇ or the like that functions as a binder is more easily generated at a lower temperature. This is particularly effective when an aluminum plate, which is disadvantageous for high-temperature drying, is used as a substrate, and the above-described softening of the aluminum plate due to high temperature can be suppressed, and a lithographic printing plate having excellent characteristics can be obtained.

  Such a reaction between a phosphoric acid compound and a metal oxide is described in “Chemical”, Japan Chemical Association, Vol. 31, No. 11, p. 895-897 (1976).

The coating liquid used for the coating process which coat | covers the coating liquid containing the said granular metal oxide and a phosphoric acid type compound to a board | substrate is demonstrated.
The metal oxide contained in the coating solution used for forming the porous layer of the present invention is not particularly limited as long as it reacts with a phosphoric acid compound described later to form a film. For example, “Zhurnal Prikladnoi Kimii”, Vo. 38, no. 7, p. 1466-1472, July 1965, and oxides of the respective metals. Specifically, oxides such as Al, Si, Ti, Zr, Y, Nd, La, Mg, Ca, Sr, Ba, Cr, Co, Fe, Ni, Sn, Pb, Cu, Zn, Cd, and Mn Among these, an oxide or composite oxide of at least one metal selected from the group consisting of Si, Mg, Zr and Ti is preferable.

More specifically, examples of the metal oxide used for forming the porous layer of the present invention include, for example, SiO ₂ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , Y ₂ O ₃ , and Nd ₂ O _3. La ₂ O ₃ , MgO, CaO, SrO, BaO, MnO ₂ , CrO ₂ , Co ₂ O ₃ , Fe ₂ O ₃ , Mn ₂ O ₃ , NiO, FeO, MnO, SnO ₂ , PbO ₂ , CuO, ZnO And metal oxides such as CdO. Examples thereof include mixed oxides of the above metal oxides such as SiO ₂ / Al ₂ O ₃ and MgO / Al ₂ O.
Further, as the composite oxide, for example, such as 2SiO ₂ · 3Al ₂ O ₃ (mullite) and the like.

  Specific examples of the metal oxide particles include the AKP series, the AKP-G series, the HIT series, the AM series (manufactured by Sumitomo Chemical Co., Ltd.), and the Nanotech series (generic names: ultrafine particles, CII Kasei Co., Ltd.). ) And other commercial products of various alumina fine particles can be used.

More specifically, the following are mentioned.
SiO ₂ (Towanalite FTB, average particle size 12 μm, manufactured by Towa Naoshi Co., Ltd .; silica sand SP-8
0, average particle size 5.5 μm, manufactured by Sanei Silica Co., Ltd .; SI-0010, average particle size 10 μm, reagent manufactured by Soekawa Rika Co., Ltd., MgO (Ube Materials 2000A, average particle size 0.2 μm, Ube Industries) MG-0076, average particle size 2 mm, Soekawa Rikagaku Co., Ltd. reagent), ZrO ₂ (Nanotech series (generic name: ultrafine particle) ZrO ₂ , average particle size 0.03 μm, CII Chemical Co., Ltd.) Manufactured by: ZR-0049, average particle size of 8 μm, reagent manufactured by Soekawa Rika Co., Ltd.), TiO ₂ (rutile, TI-0057, average particle size of 1-2 μm, reagent manufactured by Soekawa Rika Co., Ltd.), SiO ₂ / Al ₂ O ₃ (Nanotech series (generic name: ultrafine particles) SiO ₂ / Al ₂ O ₃ , average particle size 0.03 μm, manufactured by CI Kasei Co., Ltd.), MgO / Al ₂ O ₃ (Nanotech series (generic name: ultrafine particles) ) gO / Al ₂ O _3, average particle size 0.05 .mu.m, manufactured by CI Kasei _{(Inc.)), 2SiO 2 · 3Al 2} O 3 ( mixed oxide mullite (powder), an average particle diameter of 0.8 [mu] m, KCM Corporation Manufactured by AL-0111, average particle diameter of 5 mm, reagent manufactured by Soekawa Rika Co., Ltd.) and the like.
In addition to those described above, any commercially available one can be used without particular limitation.
These particles are used after adjusting the average particle diameter by pulverization or the like, if desired.

In addition to the above metal oxide, an oxide of another metal may be contained. Examples of other metal oxides include oxides of metals other than those exemplified above.
The content of the metal oxide used for forming the porous layer of the present invention is not particularly limited, but is 10 to 100% by mass of the total metal oxide including the other metal oxides. Preferably, it is 40-100 mass%.

In the present invention, the metal oxide is in the form of particles in order to take in a suitable amount of air and improve the heat insulating properties. 20-sided, 12-sided, etc.), cubic, tetrahedral, so-called complex tow, plate, needle, etc. Spherical, polyhedral, cubic, tetrahedral, and complex shapes are preferred in that they are likely to be spherical due to the reaction, and are excellent in heat insulation. .
Moreover, the mixture of these shapes may be sufficient and the hollow shape which has these shapes may be sufficient.

The average particle diameter of the particles is not particularly limited, but is preferably 0.01 to 5 μm, more preferably 0.03 to 3 μm, and further preferably 0.1 to 1.5 μm. Within this range, the film strength is high and the adjustment to the above-mentioned preferable porosity is easy.
When the adhesion to the image recording layer is insufficient, two or more kinds of metal oxide particles having different average particles may be mixed in order to increase the surface roughness. In that case, the average particle diameter of the first metal oxide particles is preferably 0.01 to 5 μm, more preferably 0.03 to 3 μm, and more preferably 0.1 to 1.5 μm. Is more preferable. The average particle diameter of the second metal oxide particles is preferably 2 to 50 times, preferably 3 to 20 times, and more preferably 4 to 10 times the average particle diameter of the first metal oxide particles. preferable.
By mixing and using the second metal oxide particles having an average particle size larger than the average particle size of the first metal oxide particles, the surface roughness can be made as desired. Become.

The content of the metal oxide in the coating solution is appropriately adjusted depending on the desired porosity and film thickness of the porous layer, but is generally preferably 5 to 60% by mass.
Further, the content is adjusted by calculating the amount of reaction with a phosphoric acid compound described later (that is, the amount of a compound containing a metal atom and a phosphorus atom) so as to dissolve the surface of the metal oxide. You can also The amount of the compound containing the metal atom and phosphorus atom can be adjusted, for example, by making the surface area of the metal oxide used constant.

That is, when forming a porous layer on another substrate using metal oxides having different average particle diameters, the following method is used to keep the amount of the compound containing metal atoms and phosphorus atoms constant. The surface area of the is constant.
For example, particle A: average particle radius r ₁ , density d ₁ , mass W ₁
Particle B: Average particle radius r ₂ , density d ₂ , mass W ₂
Since the surface area S _{1 of the} particle A is 3W ₁ / (r ₁ × d ₁ ) and the surface area S _{2 of the} particle B is 3W ₂ / (r ₂ × d ₂ ), the surface area S ₁ and Assuming that S ₂ is constant, the usage amount W ₂ of the particles B can be obtained by the following equation.
W ₂ = [(r ₂ × d ₂ ) / (r ₁ × d ₁ )] × W ₁

The phosphoric acid compound contained in the coating solution used for forming the porous layer of the present invention is not particularly limited, and examples thereof include phosphinic acid, phosphorous acid, diphosphorous acid, hypophosphoric acid, phosphorus Oxic acids such as acids (orthophosphoric acid), diphosphoric acid, triphosphoric acid, metaphosphoric acid, peroxophosphoric acid, condensed phosphoric acid, etc., 1 to 3 hydrogen atoms of these acids are metal atoms such as sodium and potassium salts Suitable examples include salts substituted with.
Among these, phosphoric acid (orthophosphoric acid and the like), salts obtained by substituting 1 to 3 hydrogen atoms of these acids with metal atoms such as sodium and potassium salts, and the like are more preferable.

These acid concentrations and the like are not particularly limited, and general ones (for example, commercially available ones) can be used.
Although it does not specifically limit as content of this phosphoric acid type compound in a coating liquid, It is preferable that it is 0.05-12 mass%, It is more preferable that it is 0.1-10 mass%, 0.3- More preferably, it is 8 mass%.
When the content of the phosphoric acid compound is within the above range, the film strength of the porous layer is strong and the porosity is also high.

Preferred combinations of the metal oxide and the phosphoric acid compound include, for example, metal oxides such as SiO ₂ , MgO, ZrO ₂ , and TiO ₂ , and mixed oxidation such as SiO ₂ / Al ₂ O ₃ and MgO / Al ₂ O _3. things, and for 2SiO ₂ · 3Al ₂ O ₃ (mullite) composite oxides, such as, phosphoric acid, sodium dihydrogen phosphate (NaH ₂ PO _4), and the like.

The coating solution preferably contains a dispersant for uniformly dispersing the metal oxide, a reaction accelerator for promoting the reaction between the metal oxide and the compound containing a metal atom and a phosphorus atom, and the like.
Although it does not specifically limit as a dispersing agent, Citric acid, hexametaphosphoric acid sodium, etc. which are generally known as dispersing agents, such as a metal oxide, can be used. Although content in a coating liquid is not specifically limited, It is 0.1-1 mass%, Preferably it is 0.2-0.8 mass%, More preferably, it is the range of 0.2-0.5 mass%.

Although it does not specifically limit as a reaction accelerator, For example, it is preferable to use the following reaction accelerators by the metal oxide to be used. Further, the content (use amount) of the accelerator is not particularly limited, and can be appropriately changed depending on the desired film thickness, porosity, etc. of the porous layer. When the content is described later, a compound containing a metal atom and a phosphorus atom can be generated at a lower temperature, and even when an aluminum plate is used as a substrate, softening of the aluminum plate can be suppressed, and a lithographic printing plate having excellent characteristics is obtained. be able to.
Preferably sodium fluoride in the case of using SiO ₂ as the metal oxide, the content thereof is preferably 1 to 5 mass% with respect to SiO _2.
When MgO is used as the metal oxide, zirconium phosphate is preferable, and the content thereof is preferably 3 to 30% by mass with respect to MgO.
When ZrO ₂ is used as the metal oxide, aluminum phosphate is preferable, and the content thereof is preferably 3 to 30% by mass with respect to ZrO ₂ .
As the metal oxide, oxides or TiO ₂ containing alumina _{SiO 2 / Al 2 O 3,} MgO / Al 2 O 3 mixed oxides such and 2SiO ₂ · 3Al ₂ O ₃ (mullite) composite oxides such as When aluminum is used, aluminum chloride is preferable, and the content thereof is preferably 5 to 100% by mass, more preferably 10 to 80% by mass with respect to Al ₂ O ₃ or TiO ₂ .

  The solvent of the coating solution is preferably water.

The coating solution is prepared by dispersing or dissolving the above-described particulate metal oxide, a phosphoric acid compound, and, if necessary, a dispersant, a reaction accelerator and the like in water.
Preferably, the particulate metal oxide is added and dispersed in an aqueous solution containing a dispersant, and after uniformly dispersing, a phosphorus compound and, if necessary, a reaction accelerator are added to the aqueous solution and stirred.

The coating solution thus prepared is applied to a substrate described later to complete the coating process.
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

Next, the drying process which heat-drys the coating liquid apply | coated to this board | substrate at 180-500 degreeC is performed.
The drying method is not particularly limited, and a commonly used method can be selected. Moreover, it is preferable that drying temperature is 180-500 degreeC. When an aluminum plate is used as the substrate, the drying temperature is preferably 180 to 220 ° C. If it is this temperature range, the softening of an aluminum plate can be suppressed and the lithographic printing plate which has the outstanding characteristic can be obtained. Moreover, when using metal plates other than an aluminum plate for a board | substrate, since there is no problem of softening of this metal plate, a drying temperature is not specifically limited, It is preferable that it is 180-500 degreeC. For example, in the case of an iron-based substrate such as a stainless steel plate, the temperature is more preferably 200 to 400 ° C.
By performing the drying step, the surface of the particulate metal oxide can be reacted with the phosphoric acid compound, and the particulate metal oxide can be left without greatly reducing its diameter.
The drying time is not particularly limited as long as it can remove the water of the coating solution, but in general, it is preferably 10 to 300 seconds, more preferably 30 to 180 seconds.

  By performing the above steps, the porous layer of the present invention can be formed on the substrate, but other steps may be performed in addition to the above steps.

  As described above, the porous layer of the present invention can be formed by applying a coating liquid containing a particulate metal oxide and a phosphoric acid compound to a substrate and drying the coating liquid. Yes, cost can be reduced.

<Sealing layer>
The porous layer of the present invention has a high porosity and has a large number of pores on its surface. Therefore, when an image recording layer is provided directly on the porous layer provided on the substrate to form a lithographic printing plate precursor, the dye as the image recording layer component enters the pores of the porous layer and remains after development. In some cases, this may cause a residual color phenomenon and a residual film phenomenon in which a binder, which is also an image recording layer component, remains after development.
Therefore, before providing the image recording layer, it is preferable to perform a sealing treatment for sealing the pores of the porous layer with high voids. As the sealing treatment, a sealing layer (also referred to as “hydrophilic layer” in the present invention).
It is preferable that the treatment is provided.
That is, the lithographic printing plate support of the present invention is preferably a lithographic printing plate support in which a sealing layer is provided on the porous layer of the present invention.

The sealing layer is not particularly limited, but a sealing layer containing a silicate compound and a hydrophilic resin is preferable.
This sealing layer can be created by forming a hydrophilic film made of a hydrophilic composition on a porous layer having a high void. The film thickness of the sealing layer can be determined as appropriate depending on the desired properties such as hydrophilicity and strength, but is generally preferably in the range of 0.01 to 0.5 μm, More preferably, it is in the range. The required hydrophilicity can be obtained when the film thickness is within the above range, and there is no fear that the hydrophilic film peels off or breaks with a slight curvature during printing or the like.
In the lithographic printing plate support having the porous layer and the sealing layer of the present invention, the thickness of the porous layer is 0.5 to 20 μm, and the thickness of the sealing layer is 0.01 to 0. More preferably, it is 5 μm. A preferable range of these film thicknesses is as described above.

  Measurement of the film thickness of the sealing layer was carried out by using a lithographic printing plate support provided with the sealing layer by bending the fractured surface, using an ultrahigh resolution scanning electron microscope (S-900, manufactured by Hitachi, Ltd.). ) And can be measured by observation. Note that the observation magnification is appropriately adjusted depending on the film thickness and the like. Specifically, the magnification is preferably 100 to 10,000 times.

  In addition, for example, when relatively large-diameter hollow particles such as shirasu balloons are used in the sealing layer, further improvement in performance can be achieved along with the film thickness. By using a mixture of small-diameter powder particles, it is possible to form a film having heat insulation, hydrophilicity, and strength, and for a lithographic printing plate precursor provided with a heat-sensitive image recording layer. This is a particularly preferred embodiment as a lithographic printing plate support.

The optimum coating amount of the sealing layer is the film thickness of the porous layer, the amount and distribution of the photothermal conversion agent contained in the image recording layer, the thickness of the image recording layer, the laser scanning speed of the exposure apparatus used, and the laser output. Depending on the shape of the exposure beam, etc., the optimum coverage can be determined experimentally in the range of 0.01 to 0.5 μm. The coating amount of the sealing layer and whether the porous layer is uniformly sealed can be observed with a high-magnification electron microscope.
Examples of the silicate compound preferably used for the sealing layer include alkali silicate water glasses such as sodium silicate, potassium silicate, and lithium silicate. The content of the silicate compound, depending on the kind of the hydrophilic resin to be used together, in general, the total solid content constituting the sealing layer, 30 to 45% by mass as SiO _2, Na ₂ O is preferably in the range of 30 to 45% by mass.

The silicate compound, particularly water glass preferably used, has a particularly high hydrophilicity, and thus has a function as a hydrophilizing agent. However, only water glass causes dehydration shrinkage and fine cracks are generated in the drying process. Further, there is a concern that the film becomes non-uniform and the film forming property is inferior, so that the printing durability may be deteriorated when used alone. In the present invention, since a hydrophilic resin is used in combination, the curing behavior of water glass and the hydrophilic resin in the drying process is different, so that a uniform film without cracks can be formed by a complementary action.
In addition, an appropriate amount of a curing agent for alkali silicates or the like known by trade names such as Cas and PC-500 (all manufactured by Nissan Chemical Industries, Ltd.) may be added to the silicate compound. .

In the sealing layer of the lithographic printing plate support of the present invention, the hydrophilic resin preferably used is not particularly limited, and is a known synthetic resin excellent in hydrophilicity, such as polyacrylic acid, polyvinyl alcohol, polyvinyl Phosphonic acid and the like, and further, novolak resins known as alkali-soluble resins, phenol-aldehyde resins, m-cresol formaldehyde resins, p
-Various hydrophilic resin compounds such as cresol formaldehyde resin. In addition, when water glass is used as the silicate compound, the acidic hydrophilic resin compound is gelled when the two are mixed because the water glass is generally present in an alkaline sol, and depending on the ordinary coating method Since uniform film formation becomes difficult, it is not preferable. In this case, it is preferable to use a hydrophilic resin that is soluble in a neutral or alkaline aqueous solvent from the viewpoint of production suitability.
However, the gel-like product obtained by mixing water glass and acidic hydrophilic resin is pulverized to about 1 μm or less using a mortar or a high-speed shear mixer, and this is washed thoroughly with water. In addition, it can be used by re-dispersing in an alkaline water solvent or water glass, and when used in this way, a predetermined hydrophilicity and film properties can be obtained, so that the neutral and alkaline hydrophilicity is not necessarily obtained. It is not limited to resin.

The content of the hydrophilic resin depends on characteristics such as desired hydrophilicity and film strength, and the type and amount of the silicate compound used together, but in general, the total solid content constituting the sealing layer Among them, the range of 4 to 40% by mass is preferable.
If a hydrophilic resin is used alone without using water glass, the hydrophilicity is insufficient, and the stain resistance and ink wiping performance may deteriorate.
Content ratio of silicate compound [SiO ₂ + Na ₂ O (mass%)] and hydrophilic resin [mass%] in the sealing layer [(SiO ₂ + Na ₂ O) (mass%) / hydrophilic resin (mass%) )] Is preferably in the range of 10 to 99. When the ratio of the silicate compound is increased too much, the film properties are lowered, and fine cracks are generated in the film, and the stain resistance and the printing durability tend to be lowered. On the contrary, if the ratio of the hydrophilic resin is excessively increased, the hydrophilicity is lowered, and the non-image portion tends to be stained.

The hydrophilic composition constituting the sealing layer should be used in combination with additives such as plasticizers, surfactants, solvents, etc. within the range that does not impair the effects of the present invention for the purpose of improving handling properties and film properties. Can do. In particular, when general-purpose polyvinyl alcohol (PVA) or the like is used as the hydrophilic resin, a heat-reactive crosslinking agent such as Etestron BN-69 (Daiichi Kogyo Seiyaku Co., Ltd.) is used for the purpose of improving the water resistance. It is preferable to add an appropriate amount.
As a method of forming a sealing layer on the porous layer, a hydrophilic composition formed by blending the above-mentioned components and additives that are used together as desired is applied on the porous layer by a spray method, a bar coating method, or the like. A method of forming a liquid film by applying to the substrate, drying with hot air at 100 to 180 ° C., and solidifying can be mentioned.

  The porosity of the sealing layer thus formed is not particularly limited. Preferably, in the lithographic printing plate support having the porous layer and the sealing layer of the present invention, the porosity of the porous layer is 20% or more, and the porosity of the sealing layer is the porous layer. Or less than the porosity. When the porosity of the sealing layer is lower than that of the porous layer, a large number of pores on the surface of the porous layer can be effectively sealed, and the residual color generated by the image recording layer entering the pores. Phenomenon and residual film phenomenon can be suppressed. The preferable range of the porosity of the porous layer is as described above.

The measurement of the porosity of the sealing layer was carried out by using a lithographic printing plate support provided with the sealing layer by bending the fractured surface, using an ultrahigh resolution scanning electron microscope (S-900, manufactured by Hitachi, Ltd.). ) In the range of 3 cm × 3 cm of the obtained image data (photograph), the area ratio of the void portion is measured. This operation is performed at 5 to 10 places, and the arithmetic average of these is defined as the porosity.
The observation magnification is appropriately adjusted according to the film thickness of the sealing layer to be observed.

By forming the sealing layer on the porous layer, a more preferable lithographic printing plate support of the present invention is obtained. Even if the support is not provided with an anodic oxide film, it exhibits excellent surface hydrophilicity and heat insulation properties due to the characteristics of the porous layer, preferably the characteristics of the porous layer and the sealing layer. And good adhesion to the image recording layer and the substrate. For this reason, when a lithographic printing plate is produced using the support, the heat generated by exposure is efficiently used for image formation and has excellent sensitivity, and the non-image area having excellent surface hydrophilicity has excellent ink repellency and stains. There is no generation and excellent in printing durability and scratch resistance.

  As a preferable aspect of the lithographic printing plate support of the present invention, the porous layer has a thickness of 0.5 to 20 μm, and the sealing layer has a thickness of 0.01 to 0.5 μm, And surface roughness Ra of a support body exists in the range of 0.3-2.0 micrometers. Hereinafter, the surface roughness Ra will be described in detail.

  The surface roughness Ra is an index representing a concavo-convex shape including large waviness on the surface of the lithographic printing plate support. When the surface roughness Ra is in the above range, the porous layer provided on the lithographic printing plate support does not impair the high heat insulation, excellent scratch resistance, printing durability and stain resistance, and further printing durability. Can improve sexiness and shinyness to a higher level.

The reason why the printing durability and the shiny property can be improved is not clear, but the following reasons are conceivable.
When the surface roughness Ra is increased, the surface becomes rough and the water retention of the non-image portion of the lithographic printing plate increases, so that the light is not regularly reflected, and as a result, the surface of the non-image portion of the lithographic printing plate is dampened during printing. Even if water is supplied, the plate surface is less likely to shine, and it is easy to visually check the amount of dampening water being supplied and adjust the amount (plate inspection property), so that the shiny property is excellent.
Further, when the surface roughness Ra is increased, the surface area in close contact with the image recording layer provided on the support (sealing layer) is increased and the adhesive strength can be strengthened, so that the printing durability is higher. Can be improved.
On the other hand, even if the surface roughness of the porous layer is limited to the above range, the voids in the porous layer are maintained, the porous layer is thick, and the porous layer is hard. The inherent heat-insulating properties, excellent scratch resistance, printing durability and stain resistance are not impaired.

  In the present invention, printing durability and shinyness can be satisfied at a higher level, and the local thickness of the heat-sensitive layer provided on the lithographic printing plate support is not impaired without deteriorating the properties of the porous layer. The surface roughness Ra is 0.3 to 2.0 μm in that unevenness can be suppressed.

In the lithographic printing plate support of the present invention, the method for measuring the average roughness Ra of the surface is as follows.
Two-dimensional roughness measurement is performed with a stylus type roughness meter (for example, sufcom 575, manufactured by Tokyo Seimitsu Co., Ltd.), the average roughness Ra defined in ISO 4287 is measured five times, and the average value is defined as the average roughness.
The conditions for the two-dimensional roughness measurement are shown below.
<Measurement conditions>
Cut-off value 0.8mm, tilt correction FLAT-ML, measurement length 3mm, vertical magnification 10000 times, scanning speed 0.3mm / sec, stylus tip diameter 2μm

  According to the present invention, a lithographic printing plate precursor can be obtained by providing a heat-sensitive image recording layer on a support having the porous layer and the sealing layer. According to this configuration, light energy by exposure, for example, laser light used for writing can be efficiently used as thermal energy necessary for image formation, and high-sensitivity, high-resolution image formation is possible, and printability is improved. An excellent lithographic printing plate precursor can be obtained.

[Middle layer]
As another embodiment of the present invention, a lithographic printing plate support comprises a coating liquid containing alumina particles, high void particles, phosphoric acid, and an aluminum compound as main components on a substrate, preferably a substrate having an aluminum surface. Is applied to form a hard ceramic layer with high voids (hereinafter also referred to as a high void hard ceramic layer or an intermediate layer). With such a configuration, it is possible to provide a lithographic printing plate support that can obtain higher sensitivity, is less susceptible to soiling, has excellent printing durability and scratch resistance, and is advantageous in terms of production cost.
The formation of the high void hard ceramic intermediate layer is performed, for example, by mixing the following A liquid and B liquid and applying and drying (120 to 180 ° C.). The reaction mechanism at that time is shown below.

A liquid: Alumina powder + high void particle + 85 mass% phosphoric acid + citric acid B liquid: AlCl ₃ (reaction accelerator)

  In the above formulas, the formulas (2) and (3) show the effect of promoting the reaction of aluminum chloride, and the right side of the formulas (1) and (3) is the composition component of the film. In the present invention, high void particles are further contained in the intermediate layer film.

  The formation of a high void hard ceramic layer that can be an intermediate layer is described in detail in FR Rep. NF (Univ. Minnesota, MN), AD RepRP AD-A-322561, 1997 p10. Therefore, in order to form the intermediate layer of the present invention, the above documents may be referred to as appropriate.

  Although it does not specifically limit as an alumina particle used in order to form the intermediate | middle layer of the support body for lithographic printing plates of this invention, The thing of an average particle diameter of 0.05-5 micrometers is preferable, More preferably, 0.08- It is 1 μm, more preferably 0.1 to 0.5 μm.

  When the adhesion to the layer provided on the support is insufficient, two or more kinds of different average particles may be contained in order to increase the surface roughness. In that case, the average particle diameter of the first alumina particles is preferably 0.05 to 5 μm, more preferably 0.08 to 1 μm, and still more preferably 0.1 to 0.5 μm. The average particle size of the second alumina particles is preferably 2 to 50 times the average particle size of the first alumina particles, more preferably 3 to 20 times, and even more preferably 4 to 10 times. By mixing the second particles, the surface roughness can be made as desired.

  Specific examples of suitable alumina particles include commercially available products of various alumina fine particles such as AKP series, AKP-G series, HIT series, AM series (manufactured by Sumitomo Chemical Co., Ltd.), nanotech ultra fine particles (CI Chemical Co., Ltd.). Can be mentioned.

The content of alumina particles in the coating solution used for forming the intermediate layer is appropriately adjusted depending on the desired porosity and thickness of the intermediate layer, but is 35 to 55% by mass in the coating solution. Is more preferable, and 40 to 50% by mass is more preferable.

  Although it does not specifically limit as content of the phosphoric acid of the coating liquid used in order to form this intermediate | middle layer, 0.05-12 mass% in a coating liquid is preferable, More preferably, 0.1-10 mass%, More preferably, it is 0.3-8 mass%.

  Examples of suitable high void particles used in the present invention include hollow particles. The following can be used as the hollow particles, which are characteristic constituents for retaining the independent pores of the intermediate layer of the present invention, but of course not limited thereto.

  Examples of inorganic hollow particles include silica-based inorganic fine particles called shirasu balloons. The Shirasu Baru was developed at the Kyushu Industrial Laboratory, and was made by firing and foaming glassy volcanic debris such as Shirasu. However, hollow particles having an average particle size of 10 μm or less can be produced by the research of Sodeyama et al. Such particles are used as lightweight aggregates for cement, fillers for paints, and lightweight fireproof building materials, and are commercially available from Shirakusu, Sanki Chemical Construction Machinery, Showa Mining, and Shin Sangyo.

  Examples of the hollow particles used in the present invention include not only the above silica type but also titanium oxide type hollow particles. Also, very fine hollow particles of 1-10 nm obtained by hydrothermal synthesis after rapid mixing of silicon compound and aluminum compound solutions described in JP-A-10-236818 to remove by-produced salts, A suitable example is a hollow particle of zinc oxide of about 0.05 to 0.1 μm reported in Kaihei 7-328421.

  Examples of the organic hollow particles include the hollow particles described in Material Technology, Volume 11, (No. 3) 22-30 (1993). In the present invention, although the production method is not limited, emulsion polymerization, emulsion polymerization, gas foaming type suspension polymerization and the like are known as general production methods for organic hollow particles. Products can be obtained from Mitsui Chemicals, Inc., Zeon Corporation, JSR Corporation, and the like. It is used for applications such as organic pigments for coated paper, resin lightening agents, and clouding agents.

In addition to the hollow particles, porous particles and anisotropic particles are also suitable as the high void particles used in the present invention. Here, the porous particle is a particle having fine pores inside the particle, and generally has a specific surface area in the gas adsorption method as compared with a normal non-porous particle having the same particle diameter. The feature is that is large. The specific surface area of the porous particles is what is often 50m ² / g~200m ² / g approximately. In addition, anisotropic particles are particles that are not isotropic, such as needles, feathers, and flats, that do not become spherical even if the outer shape of the particles is approximated at multiple points.

Examples of the aluminum compound used for forming the intermediate layer of the present invention include aluminum halide. Of these, aluminum chloride is preferred.
This aluminum compound functions as a reaction accelerator. When aluminum chloride is used as the reaction accelerator, the content in the coating solution used to form the intermediate layer is not particularly limited, but the mass ratio to alumina is AlCl ₃ : Al ₂ O ₃ = 0. .01: 1 to 0.3: 1 are preferable, AlCl ₃ : Al ₂ O ₃ = 0.01: 1 to 0.2: 1, more preferably AlCl ₃ : Al ₂ O ₃ = 0. .01: 1 to 0.1: 1.

Moreover, it is desirable that the coating solution used for forming the intermediate layer contains various dispersants for uniformly dispersing alumina in water. The dispersant is not particularly limited, and citric acid, sodium hexametaphosphate and the like, which are generally known as alumina dispersants, can be used. Although content in a coating liquid is not specifically limited, 0.1 mass%-1 mass%, Desirably 0.2 mass%-0.8 mass%, More desirably, 0.2 mass%-0.5 mass% Range.

  1-50 micrometers is preferable, as for the average thickness of the said intermediate | middle layer of this invention, More preferably, it is 3-40 micrometers, More preferably, it is 5-30 micrometers. Within this range, good heat insulation and strength can be obtained, and sufficient sensitivity can be obtained when a heat-sensitive lithographic printing plate is obtained. The porosity of the intermediate layer is preferably 5 to 70%, more preferably 10 to 60%, and still more preferably 15 to 50%. Within this range, good heat insulation and strength can be obtained, and sufficient sensitivity can be obtained when a heat-sensitive lithographic printing plate is obtained.

The porosity is a value calculated by the following formula from the intermediate layer film weight W (g / m ² ) and the film thickness d (μm).
Porosity V (%) = {1− (W / d / 3.89)} × 100

Here, the intermediate | middle layer membrane | film | coat weight W (g / m < ² >) is the value measured according to the Mason method (JIS H8680-1993 membrane weight method). The film thickness d (μm) was obtained by embedding an aluminum plate having an intermediate layer in a resin, cutting it, and finally buffing the cross section with 0.1 μm alumina to finish the finished surface into an SEM. The value obtained by averaging the observation results at 20 randomly selected locations was used.

[Hydrophilic layer]
Since the high void hard ceramic intermediate layer has high voids, it has a large number of pores on its surface. In order to apply the support of the present invention to a lithographic printing plate material, when a heat-sensitive layer is provided directly on the high void hard ceramic intermediate layer, the dye which is a heat-sensitive layer component enters the pores, and also after development. This may cause a decrease in remaining color and a decrease in remaining film in which the binder, which is also a heat-sensitive layer component, remains after development. Therefore, before providing the heat sensitive layer, it is necessary to seal the high void hard ceramic intermediate layer. In the sealing treatment, it is preferable to provide a sealing hydrophilic layer (hereinafter also simply referred to as a hydrophilic layer).

The hydrophilic layer for sealing is not particularly limited, but a hydrophilic layer containing a silicate compound and a hydrophilic resin is preferable.
This hydrophilic layer can be prepared by forming a hydrophilic film made of a hydrophilic composition on the high void hard ceramic intermediate layer. The thickness of the hydrophilic layer can be appropriately determined depending on desired properties such as hydrophilicity and strength, but is generally preferably in the range of 0.2 μm to 50 μm, and more preferably in the range of 1 μm to 8 μm. When the film thickness is within the above range, the required hydrophilicity can be obtained, and there is no fear that the hydrophilic film will be peeled off or broken by a slight curve during printing or the like.

  Further, for example, when relatively large diameter hollow particles such as Shirasu balloons are used in the hydrophilic layer, it is possible to further improve the performance along with the thickness, and the relatively large diameter powder, By mixing and using small-sized powder particles, it is possible to form a film having both heat insulation, hydrophilicity, and strength, which is a particularly desirable aspect as a support for a lithographic printing plate having a heat-sensitive layer.

As the silicate compound preferably used for the hydrophilic layer of the present invention, alkali silicate water glass such as sodium silicate, potassium silicate, lithium silicate and the like is suitable. The content of the silicate compound depends on the kind of the hydrophilic resin used together, but generally 30 to 45 mass% as SiO ₂ in the total solid content constituting the hydrophilic layer, Na ₂ O is preferably in the range of 30 to 45 mass%.

Silicate compounds, especially water glass, which is preferably used, has a particularly high hydrophilicity, and thus has a function as a hydrophilizing agent. However, water glass alone causes dehydration shrinkage and fine cracks are generated during the drying process In addition, there is a concern that the film becomes non-uniform and the film forming property is inferior, so that the printing durability is deteriorated when used alone. In the present invention, since the hydrophilic resin is used in combination, the curing behavior of the water glass and the hydrophilic resin in the drying process is different, so that a uniform film without cracks can be formed by a complementary action.
In addition, an appropriate amount of a curing agent for alkali silicates or the like known by trade names such as Cas and PC-500 (all manufactured by Nissan Chemical Industries, Ltd.) may be added to the silicate compound. .

In the hydrophilic layer of the support of the present invention, the hydrophilic resin preferably used is not particularly limited, and a known synthetic resin excellent in hydrophilicity, for example, polyacrylic acid, polyvinyl alcohol, polyvinylphosphonic acid, etc. Examples include various hydrophilic resins.
In addition, when water glass is used as the silicate compound, the acidic hydrophilic resin compound is gelled when the two are mixed because the water glass is generally present in an alkaline sol, and depending on the ordinary coating method Since uniform film formation becomes difficult, it is not preferable. In this case, it is preferable to use a hydrophilic resin that is soluble in a neutral or alkaline aqueous solvent from the viewpoint of production suitability.
However, the gel-like material obtained by mixing water glass and acidic hydrophilic resin is pulverized to about 1 μm or less using a mortar or a high-speed shear mixer, and this is washed thoroughly with water. In addition, it can be used by re-dispersing in an alkaline water solvent or water glass, and when used in this way, a predetermined hydrophilicity and film properties can be obtained, so that the neutral and alkaline hydrophilicity is not necessarily obtained. It is not limited to resin.

The content of the hydrophilic resin depends on characteristics such as desired hydrophilicity and film strength, and the type and amount of the silicate compound used together, but generally the total solid content constituting the hydrophilic layer. Among them, the range of 4 to 40% by mass is preferable.
If a hydrophilic resin is used alone without using water glass, the hydrophilicity is insufficient, and the stain and ink wiping performance deteriorates.
Content ratio of silicate compound [SiO ₂ + Na ₂ O (mass%)] and hydrophilic resin [mass%] in the hydrophilic layer [(SiO ₂ + Na ₂ O) (mass%) / hydrophilic resin (mass%) )] Is preferably in the range of 1-9. Within the above range, preferable stain resistance and printing durability can be obtained.

In the hydrophilic layer according to the present invention, in addition to the above-mentioned components, a powder containing an inorganic component as a main component (hereinafter, appropriately referred to as inorganic fine particles) is further mixed to thereby increase the hardness of the hydrophilic layer. Improvement in heat resistance, improvement in optical properties such as whiteness and glossiness, and improvement in adhesion to the substrate and the heat-sensitive layer due to an increase in surface area. Furthermore, by reflecting the characteristics unique to the inorganic fine particles, it is possible to improve the reflection and absorption effects of infrared rays used for exposure and to add various functions such as catalysis.
In the present invention, as the inorganic fine particles preferably used, from the viewpoint of improving dispersibility in the hydrophilic layer, inorganic fine particles mainly composed of hydrophilic inorganic components are used, or hydrophilic surface modification is performed on the surface of the inorganic fine particles. It is desirable to use a processed one.

Examples of inorganic components that can be used include, as metals, metal materials having hydrophilicity such as Al, Fe, Pt, Pd, and Au alloys, and include coal, charcoal, diamond, DLC (diamond-like coating), graphite. Carbons such as glassy carbon, oxides, nitrides, silicides, and carbides are also preferred.
Specific examples of oxides, nitrides, silicides, and carbides are listed below. Examples of oxides include aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, hafnium oxide, vanadium oxide, niobium oxide, tantalum oxide, molybdenum oxide, tungsten oxide, chromium oxide,
Examples thereof include germanium oxide, gallium oxide, tin oxide, and indium oxide. Further, as nitrides, aluminum nitride, silicon nitride, titanium nitride, zirconium nitride, hafnium nitride, vanadium nitride, niobium nitride, tantalum nitride, molybdenum nitride, tungsten nitride, chromium nitride. , Silicon nitride, boron nitride and the like. Examples of the silicide include titanium silicide, zirconium silicide, hafnium silicide, vanadium silicide, niobium silicide, tantalum silicide, molybdenum silicide, tungsten silicide, and chromium silicide. Examples of the boride include titanium boride, zirconium boride, hafnium boride, vanadium boride, niobium boride, tantalum boride, molybdenum boride, tungsten boride, and chromium boride. Examples of the carbide include aluminum carbide, silicon carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide, molybdenum carbide, tungsten carbide, and chromium carbide.

  Among these, aluminum and titanium are preferable for metals, and aluminum oxide, iron oxide, titanium oxide, indium oxide, tin oxide, and silicon oxide are preferable for oxides, and any of these components is the main component. Fine particles are preferred. These inorganic components can be used not only as a simple substance but also as a mixture.

The shape of the inorganic fine particles may be any of spherical, cylindrical, flaky powder, hollow particles, porous particles, and irregular fine particles. From the viewpoint of hydrophilicity, sensitivity improvement effect, etc., the flaky powder, hollow Particles and porous particles are most preferred.
The size of the fine particles depends on the desired properties of the hydrophilic layer, but generally a diameter of about 0.01 to 10 μm is preferable.

The content of the inorganic fine particles is appropriately selected depending on the purpose of blending, but is generally preferably about 4 to 40% by mass.
These inorganic fine particles can be used not only alone but also as a mixture of plural kinds. You may mix and use the powder which consists of a several different kind of inorganic component, and it can also be used combining the some inorganic fine particle from which a magnitude | size (particle diameter) differs as mentioned above.
When blending inorganic fine particles, it is preferable to blend by blending the same amount of hydrophilic resin as the amount of inorganic fine particles out of the components constituting the hydrophilic layer. A preferable blending ratio of the hydrophilic layer containing inorganic fine particles is in a range of 1 <[(SiO ₂ + Na ₂ O) (mass%) / (hydrophilic resin + inorganic fine particles) (mass%)] <9.

In the hydrophilic composition constituting the hydrophilic layer, additives such as a plasticizer, a surfactant, and a solvent may be used in combination so as not to impair the effects of the present invention for the purpose of improving handling properties and film properties. Can do. In particular, when general-purpose polyvinyl alcohol (PVA) or the like is used as the hydrophilic resin, a heat-reactive crosslinking agent such as Etestron BN-69 (Daiichi Kogyo Seiyaku Co., Ltd.) is used for the purpose of improving the water resistance. It is desirable to add an appropriate amount.
As a method of forming a hydrophilic layer on the intermediate layer, a hydrophilic composition formed by blending the above-mentioned components and additives used in combination as desired is applied on the intermediate layer by a spray method, a bar coating method, or the like. Then, a liquid film may be formed, dried by hot air at 100 ° C. to 180 ° C., and solidified.

By forming the hydrophilic layer on the intermediate layer, a more preferable lithographic printing plate support of the present invention is obtained. Even if this support is not provided with an anodic oxide film, it exhibits excellent surface hydrophilicity and heat insulation properties due to the properties of the intermediate layer and the hydrophilic layer, and also has good film properties and is suitable for the heat-sensitive layer and the substrate. Excellent adhesion.
For this reason, the heat-sensitive lithographic printing plate produced using this support is highly sensitive because the heat generated by infrared laser exposure is efficiently used for image formation, and the non-image area having excellent surface hydrophilicity is Since it has excellent ink repellency, it has good resistance to dirt, and has excellent printing durability due to its excellent adhesion.
Further, this lithographic printing plate support is advantageous in terms of production cost because it is not necessary to provide an anodized film.

<Board>
The substrate used for the lithographic printing plate support of the present invention is not particularly limited. For example, a pure aluminum plate, an alloy plate containing aluminum as a main component and a trace amount of different elements, and a metal element other than aluminum as a main component. And various metal plates, those coated with these alloy plates or metal plates, and plastic films on which a metal such as aluminum is laminated or vapor-deposited.
As an alloy plate containing aluminum as a main component and containing a trace amount of different elements, an aluminum alloy plate described later is preferably mentioned. Various metal plates containing a metal element other than aluminum as a main component have flexibility and high strength. Inexpensive and inexpensive stainless steel plate, nickel plate, copper plate, magnesium alloy plate and the like are preferable.
Preferred examples of the alloy plate or metal plate coated are those obtained by coating the above alloy plate and various metal plates with a thin layer of a metal atom or a metal oxide by a method such as sputtering or lamination. More preferably, the metal atom or metal oxide is the same type as the metal oxide or metal atom used for forming the porous layer.

  Among these, as the substrate used in the present invention, the above-described various metal plates that do not have a problem of softening due to heating, the metal oxide used for forming the porous layer, or the same metal atom or metal oxide as the metal atom is used. A thin layer coated by a method such as sputtering or laminating is preferable, and an aluminum plate that is excellent in rust prevention, high in recyclability, small in specific gravity, excellent in handleability, and inexpensive is also preferable.

The substrate coated with the various metal plates may be coated with the above stainless steel plate, nickel plate or the like by sputtering under the usual conditions, or may be coated by laminating or the like.
The film thickness of the coating is not particularly limited, but generally may be about 10 nm or more. Preferably it is 10-100 nm, More preferably, it is 25-50 nm. In general, if the coating thickness is thin, the various metal plates cannot be sufficiently coated, and the adhesion to the porous layer of the present invention may be inferior. On the other hand, if the coating thickness is thick, the coating becomes expensive. Therefore, in the present invention, the film thickness is appropriately selected from these viewpoints.
Commercially available products may be used for the various metal plates used in the present invention and the substrates coated with these.

As the substrate used for the lithographic printing plate support of the present invention, a substrate having an aluminum surface is preferable. Examples of such a substrate include an aluminum substrate, paper and resin laminated with aluminum, and a substrate coated with aluminum.
Among them, aluminum that is excellent in rust prevention, high in recyclability and light in specific gravity is excellent in handleability and inexpensive.

Next, an aluminum plate preferable as a substrate used in the present invention will be described.
The composition of the aluminum plate used in the present invention is not specified. For example, conventionally known materials described in the 4th edition of the Aluminum Handbook (1990, published by Light Metal Association), such as JIS A1050, JIS Al-Mn aluminum plates such as A1100, JIS A1070, JIS A3004 containing Mn, and internationally registered alloy 3103A can be appropriately used. Further, for the purpose of increasing the tensile strength, an Al-Mg-based alloy or an Al-Mn-Mg-based alloy (JIS A3005) in which 0.1 mass% or more of magnesium is added to these aluminum alloys can also be used. Furthermore, Al-Z containing Zr and Si
An r-based alloy or an Al—Si based alloy can also be used. Furthermore, an Al—Mg—Si based alloy can also be used.

  Regarding the JIS 1050 material, the techniques proposed by the applicant of the present application are disclosed in Japanese Patent Application Laid-Open Nos. 59-153861, 61-51395, 62-146694, 60-215725, and 60-215725. JP 60-215726, JP 60-215727, JP 60-216728, JP 61-272367, JP 58-11759, JP 58-42493, JP 58- 221254, JP-A-62-148295, JP-A-4-254545, JP-A-4-165541, JP-B-3-68939, JP-A-3-234594, JP-B-1-47545, and JP-A-62. It is described in each publication of -140894. In addition, techniques described in Japanese Patent Publication No. 1-35910 and Japanese Patent Publication No. 55-28874 are also known.

  Regarding the JIS1070 material, the techniques proposed by the applicant of the present application are disclosed in JP-A-7-81264, JP-A-7-305133, JP-A-8-49034, JP-A-8-73974, JP-A-8-108659 and It is described in JP-A-8-92679.

  Regarding Al-Mg alloys, the techniques proposed by the applicant of the present application are disclosed in Japanese Patent Publication Nos. Sho 62-5080, Sho 63-60823, Shoko 3-61753, JP Sho 60-20396, JP-A-60-203497, JP-B-3-11635, JP-A-61-274993, JP-A-62-23794, JP-A-63-47347, JP-A-63-47348, JP-A-63-47349. JP-A 64-1293, JP-A 63-135294, JP-A 63-87288, JP-B 4-73392, JP-B 7-100844, JP-A 62-149856, JP-B JP-A-4-73394, JP-A-62-181191, JP-B-5-76530, JP-A-63-30294, and JP-B-6-37116. Also described in JP-A-2-215599, JP-A-61-201747, and the like.

  With regard to Al—Mn alloys, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 60-230951, 1-306288, and 2-293189. In addition, JP-B-54-42284, JP-B-4-19290, JP-B-4-19291, JP-B-4-19292, JP-A-61-35995, JP-A-64-51992, JP-A-4-19592, No. 226394, US Pat. No. 5,009,722, US Pat. No. 5,028,276 and the like.

  With regard to the Al—Mn—Mg alloy, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 62-86143 and 3-2222796. JP-B 63-60824, JP-A 60-63346, JP-A 60-63347, JP-A-1-293350, European Patent No. 223,737, US Pat. No. 4,818, No. 300, British Patent No. 1,222,777, etc.

  Regarding the Al—Zr alloy, the technique proposed by the applicant of the present application is described in Japanese Patent Publication No. 63-15978 and Japanese Patent Application Laid-Open No. 61-51395. Also described in JP-A-63-143234 and JP-A-63-143235.

  The Al—Mg—Si alloy is described in British Patent 1,421,710.

In order to use an aluminum alloy as a plate material, for example, the following method can be employed. First, a molten aluminum alloy adjusted to a predetermined alloy component content is subjected to a cleaning process and cast according to a conventional method. In the cleaning process, in order to remove unnecessary gas such as hydrogen in the molten metal, flux treatment, degassing process using argon gas, chlorine gas, etc., so-called rigid media filter such as ceramic tube filter, ceramic foam filter, A filtering process using a filter that uses alumina flakes, alumina balls or the like as a filter medium, a glass cloth filter, or a combination of a degassing process and a filtering process is performed.

  These cleaning treatments are preferably performed in order to prevent defects caused by foreign matters such as non-metallic inclusions and oxides in the molten metal and defects caused by gas dissolved in the molten metal. Regarding filtering of the molten metal, JP-A-6-57432, JP-A-3-162530, JP-A-5-140659, JP-A-4-231425, JP-A-4-276031, JP-A-5-311261, JP-A-5-311261 6-136466 and the like. Further, the degassing of the molten metal is described in JP-A-5-51659, Japanese Utility Model Laid-Open No. 5-49148, and the like. The applicant of the present application has also proposed a technique relating to degassing of molten metal in Japanese Patent Application Laid-Open No. 7-40017.

Next, casting is performed using the molten metal that has been subjected to the cleaning treatment as described above. Regarding the casting method, there are a method using a solid mold typified by a DC casting method and a method using a driving mold typified by a continuous casting method.
In DC casting, solidification occurs at a cooling rate of 0.5 to 30 ° C./second. When the temperature is less than 1 ° C., many coarse intermetallic compounds may be formed. When DC casting is performed, an ingot having a thickness of 300 to 800 mm can be manufactured. The ingot is chamfered as necessary according to a conventional method, and usually 1 to 30 mm, preferably 1 to 10 mm, of the surface layer is cut. Before and after that, soaking treatment is performed as necessary. When performing a soaking treatment, heat treatment is performed at 450 to 620 ° C. for 1 to 48 hours so that the intermetallic compound does not become coarse. If the heat treatment is shorter than 1 hour, the effect of soaking may be insufficient.

  Then, hot rolling and cold rolling are performed to obtain a rolled aluminum plate. An appropriate starting temperature for hot rolling is 350 to 500 ° C. An intermediate annealing treatment may be performed before or after hot rolling or in the middle thereof. The conditions for the intermediate annealing treatment are heating at 280 to 600 ° C. for 2 to 20 hours, preferably 350 to 500 ° C. for 2 to 10 hours using a batch annealing furnace, or 400 to 600 ° C. using a continuous annealing furnace. Heating is performed for 6 minutes or less, preferably 450 to 550 ° C. for 2 minutes or less. The crystal structure can be made finer by heating at a heating rate of 10 to 200 ° C./second using a continuous annealing furnace.

  The flatness of the aluminum plate finished to a predetermined thickness, for example, 0.1 to 0.6 mm by the above steps may be further improved by a correction device such as a roller leveler or a tension leveler. The flatness may be improved after the aluminum plate is cut into a sheet shape, but in order to improve the productivity, it is preferably performed in a continuous coil state. Further, a slitter line may be used for processing into a predetermined plate width. Moreover, in order to prevent generation | occurrence | production of the damage | wound by friction between aluminum plates, you may provide a thin oil film on the surface of an aluminum plate. As the oil film, a volatile or non-volatile film is appropriately used as necessary.

On the other hand, as the continuous casting method, a twin roll method (hunter method), a method using a cooling roll typified by the 3C method, a double belt method (Hazley method), a cooling belt or a cooling block typified by Al-Swiss Caster II type The method using is industrially performed. When the continuous casting method is used, it solidifies at a cooling rate of 100 to 1000 ° C./second. Since the continuous casting method generally has a higher cooling rate than the DC casting method, it has a feature that the solid solubility of the alloy component in the aluminum matrix can be increased. Regarding the continuous casting method, the techniques proposed by the applicant of the present application are disclosed in JP-A-3-79798, JP-A-5-201166, JP-A-5-156414, JP-A-6-262203, and JP-A-6-122949. JP-A-6-210406 and JP-A-6-26308.

  When continuous casting is performed, for example, if a method using a cooling roll such as a Hunter method is used, a cast plate having a thickness of 1 to 10 mm can be directly cast continuously, and the hot rolling step is omitted. The advantage of being able to In addition, when a method using a cooling belt such as the Husley method is used, a cast plate having a thickness of 10 to 50 mm can be cast. Generally, a hot rolling roll is arranged immediately after casting and continuously rolled. Thus, a continuous cast and rolled plate having a thickness of 1 to 10 mm is obtained.

  These continuous cast and rolled plates are subjected to processes such as cold rolling, intermediate annealing, improvement of flatness, slits, and the like in the same manner as described for DC casting. Finished to a plate thickness of 6 mm. Regarding the intermediate annealing condition and the cold rolling condition when using the continuous casting method, the techniques proposed by the applicant of the present application are disclosed in JP-A-6-220593, JP-A-6-210308, JP-A-7-54111, It is described in JP-A-8-92709.

Various characteristics described below are desired for the aluminum plate thus manufactured.
As for the strength of the aluminum plate, it is preferable that the 0.2% proof stress is 140 MPa or more in order to obtain the stiffness required for a lithographic printing plate support. Moreover, in order to obtain a certain level of waist strength even when performing a burning treatment, the 0.2% yield strength after heat treatment at 270 ° C. for 3 to 10 minutes is preferably 80 MPa or more, and 100 MPa or more. It is more preferable that In particular, when the waist strength is required for an aluminum plate, an aluminum material added with Mg or Mn can be used, but if the waist is strengthened, the ease of fitting to the plate cylinder of a printing press becomes inferior. Depending on the application, the material and the amount of trace components added are appropriately selected. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Application Laid-Open Nos. 7-126820 and 62-140894.

  The crystal structure of the aluminum plate may cause poor surface quality when the surface of the aluminum plate is subjected to chemical or electrochemical surface roughening. It is preferably not too coarse. The crystal structure on the surface of the aluminum plate preferably has a width of 200 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, and the length of the crystal structure is 5000 μm or less. Is preferably 1000 μm or less, and more preferably 500 μm or less. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 6-218495, 7-39906, and 7-124609.

  The alloy component distribution of the aluminum plate, when chemical surface roughening treatment or electrochemical surface roughening treatment is performed, poor surface quality occurs due to non-uniform distribution of the alloy component on the surface of the aluminum plate. Therefore, it is preferable that the surface is not very uneven. With regard to these, the techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 6-48058, 5-301478, and 7-132689.

  In the intermetallic compound of the aluminum plate, the size and density of the intermetallic compound may affect the chemical roughening treatment or the electrochemical roughening treatment. With regard to these, techniques proposed by the applicant of the present application are described in Japanese Patent Laid-Open Nos. 7-138687 and 4-254545.

In the present invention, an aluminum plate as shown above can be used with unevenness by lamination rolling, transfer or the like in the final rolling step.

The aluminum plate used in the present invention is a continuous belt-like sheet material or plate material. That is, it may be an aluminum web or a sheet-like sheet cut to a size corresponding to a planographic printing plate precursor shipped as a product.
Since scratches on the surface of the aluminum plate may become defects when processed into a lithographic printing plate support, it is possible to generate scratches at the stage prior to the surface treatment process for making a lithographic printing plate support It is necessary to suppress as much as possible. For that purpose, it is preferable that the package has a stable form and is not easily damaged during transportation.
In the case of an aluminum web, for example, the packing form of aluminum is, for example, laying a hardboard and felt on an iron pallet, applying cardboard donut plates to both ends of the product, wrapping the whole with a polytube, and inserting a wooden donut into the inner diameter of the coil Then, a felt is applied to the outer periphery of the coil, the band is squeezed with a band, and the display is performed on the outer periphery. Moreover, a polyethylene film can be used as the packaging material, and a needle felt or a hard board can be used as the cushioning material. There are various other forms, but the present invention is not limited to this method as long as it is stable and can be transported without being damaged.

  Although the board thickness of the board | substrate used for this invention is not specifically limited, It is preferable that it is about 0.1-0.6 mm, It is more preferable that it is 0.15-0.4 mm, 0.2-0.3 mm More preferably.

<Surface treatment>
In the present invention, by providing a porous layer, a lithographic printing plate having both excellent stain resistance and printing durability when obtained as a lithographic printing plate and having excellent printing performance can be obtained. In general, surface treatment of the substrate (for example, various surface roughening treatments, anodizing treatment, etc.) can also be performed.

The lithographic printing plate support of the present invention can be produced by a simple process of applying and drying a coating solution without performing a surface treatment, and is excellent in sensitivity, stain resistance and printing durability. The manufacturing cost can be greatly reduced with respect to the conventional lithographic printing plate support subjected to the above.
In addition, since the lithographic printing plate support of the present invention does not form the anodic oxide film, it does not require electrolytic treatment (a large amount of electricity) necessary for the film formation, and the cost can be reduced.

<Method for producing support for lithographic printing plate>
Although the manufacturing method of the support for lithographic printing plates of this invention is not specifically limited, For example, it can manufacture with the following manufacturing methods.
That is, (I) the substrate is roughened, and a porous layer formed by binding metal oxide particles with a compound containing metal atoms and phosphorus atoms is provided on the roughened substrate. Furthermore, a method of providing a sealing layer on the porous layer,
(II) On the substrate, a porous layer formed by binding metal oxide particles with a compound containing a metal atom and a phosphorus atom is provided, and the porous layer is subjected to a mechanical surface roughening treatment. A method of providing a sealing layer on the roughened porous layer, and
(III) A porous layer formed by binding two or more kinds of metal oxide particles having different average particle diameters with a compound containing a phosphorus atom is provided on the substrate, and a sealing layer is provided on the porous layer. It is a method of providing.
Hereinafter, the production methods (I) to (III) will be described.

<Roughening treatment>
In the method (I), first, the substrate is roughened.
The roughening treatment is not particularly limited, and may include various roughening treatments generally performed in the production of a lithographic printing plate support. For example, the substrate may be anodized before the surface roughening treatment.
In the present invention, the surface roughening treatment is preferably a mechanical surface roughening treatment or a direct current electrolytic surface roughening treatment in that the surface roughness Ra can be easily adjusted to the above range. The mechanical surface roughening treatment is more preferable in terms of easier adjustment, easier work, and lower cost.
In addition to these roughening treatments, other roughening treatments may be performed.

<Mechanical roughening>
In general, the mechanical surface roughening treatment is cheaper than the electrochemical surface roughening treatment, and the surface roughness Ra is within the above range (surface shape having an average wavelength exceeding several μm). Therefore, it is effective as a roughening treatment means.
Examples of the mechanical surface roughening treatment method include a wire brush grain method in which the substrate surface is scratched with a metal wire, a ball grain method in which the substrate surface is grained with a polishing ball and an abrasive, JP-A-6-135175, and Japanese Patent Publication A brush grain method in which the surface is grained with a nylon brush and an abrasive described in Japanese Patent No. 50-40047 can be used.
A transfer method in which the uneven surface is pressed against the substrate can also be used. That is, in addition to the methods described in JP-A-55-74898, JP-A-60-36195, JP-A-60-20396, and JP-A-7-205565, transfer is performed several times. The method described in JP-A-6-55871 characterized in that it is carried out and JP-A-6-24168 characterized in that the surface is elastic is also applicable. Examples of the method for forming the uneven surface (transfer grain) include, for example, JP-A-7-205565, JP-A-6-183168, JP-A-6-55871, JP-A-6-24168, and JP-A-6-171261. And JP-A-6-171236 and JP-A-60-20396.

In addition, by using electric discharge machining, shot blasting, laser, plasma etching, etc., a method of performing repetitive transfer using a transfer roll in which fine irregularities are etched, or an uneven surface coated with fine particles is contacted with a substrate. It is also possible to use a method in which a concavo-convex pattern corresponding to the average diameter of fine particles is repeatedly transferred to a substrate a plurality of times by applying pressure repeatedly to the surface and applying a plurality of pressures thereon. As a method for imparting fine irregularities to the transfer roll, known methods described in JP-A-3-8635, JP-A-3-66404, JP-A-63-65017, etc. may be used. it can. Further, a fine groove may be cut from two directions using a die, a cutting tool, a laser, or the like on the roll surface, and the surface may be provided with square irregularities. The roll surface may be subjected to a known etching process or the like so that the formed square irregularities are rounded.
Further, in order to increase the surface hardness, quenching, hard chrome plating, or the like may be performed.
In addition, as the mechanical surface roughening treatment, methods described in JP-A Nos. 61-162351 and 63-104889 can be used.
Moreover, the method of spraying the slurry-like aqueous solution containing an abrasive | polishing agent with a high pressure jet like the honing method can also be used.
In the present invention, the above-described methods can be used in combination in consideration of productivity and the like.

Among the above, the mechanical roughening treatment is more preferably a brush grain method or a transfer method, and particularly preferably a brush grain method described later.
Among the above transfer methods, the method described in JP-A-7-205565 is more preferable. Here, the transfer method described in JP-A-7-205565 specifically transfers the surface of the aluminum substrate so that the area ratio of the independent recesses is 5 to 70% using a transfer roller. This is a method of increasing the area ratio of the recesses to 75% or more by performing a post-process by chemical etching after the process. In the present invention, the post-treatment by chemical etching may or may not be performed.

As a method of forming the uneven surface (transfer grain) on the surface of the transfer roller used in the transfer method, among those described above, there is a method of roughening with a laser described in JP-A-6-171261. It is preferable because a transfer roll can be obtained in which the depth, diameter, arrangement, etc. of the recessed portions of the uneven surface to be formed are uniformly controlled.
The transfer roll used in the transfer method is not limited to metal, and may be made of resin, or may be a transfer roll coated with a general silicone resin or the like as a corrosion inhibitor or a release agent. .

Hereinafter, the brush grain method used suitably as a mechanical roughening process is demonstrated.
In the method (I) for producing a lithographic printing plate support of the present invention, the mechanical surface roughening treatment is performed using a rotating brush and a slurry containing an abrasive.
The brush grain method uses a roller-shaped brush in which a large number of brush bristles, such as synthetic resin bristles made of synthetic resin such as nylon (trademark), propylene, and vinyl chloride resin, are rotated on the surface of a cylindrical body. This is performed by rubbing one or both of the surfaces of the substrate while spraying a slurry containing an abrasive on a roller-like brush (hereinafter also referred to as “rotating brush”).

  The rotating brush used in the present invention is not particularly limited, but it is preferable to use a brush having an appropriate bristle strength.

Examples of the rotary brush include a bundle planting brush and a channel brush.
The material of the abrasive used in the present invention is not particularly limited, and known materials can be used. For example, abrasives such as pumiston, silica sand, aluminum hydroxide, alumina powder, silicon carbide, silicon nitride, volcanic ash, carborundum, and gold sand; a mixture thereof can be used. Of these, pumiston, silica sand, and alumina powder are preferable.
The shape of the abrasive particles is not particularly limited, and examples thereof include a spherical shape, a plate shape, an indefinite shape, and a shape in which the corners of a geometric solid are rounded.

  For example, the abrasive is suspended in water and used as a slurry. In addition to the abrasive, the slurry can contain a thickener, a dispersant (for example, a surfactant), a preservative, and the like. The specific gravity of the slurry is preferably 0.5-2.

As an apparatus suitable for the mechanical surface roughening treatment, for example, an apparatus described in Japanese Patent Publication No. 50-40047 can be given.
FIG. 1 is a side view showing the concept of the brush graining process. As shown in FIG. 1, rotating brushes 2 and 4 and two supporting rollers 5, 6, 7, and 8 are arranged with a substrate 1 interposed therebetween. The two support rollers 5, 6 and 7, 8 are arranged such that the shortest distance between the outer surfaces of each of the support rollers 5, 6 and 7, 8 is smaller than the outer diameter of the rotating brushes 2 and 4. The substrate 1 is pressurized by the rotating brushes 2 and 4 and is conveyed at a constant speed while being pushed between the two support rollers 5, 6, 7, and 8, and the polishing slurry liquid 3 is transferred to the substrate 1. The surface is polished by the rotation of the rotating brushes 2 and 4 supplied on the surface.

The direct current electrolytic surface roughening treatment suitably used in the manufacturing method (I) is a method of electrochemical surface roughening using a large amount of direct current, whereby large and deep irregularities can be formed. The surface roughness Ra can be easily adjusted to the above range.
Here, in the DC electrolytic graining treatment, the total amount of electricity furnished to anode reaction of the substrate is preferably from 50~1500C / dm ^2, and more preferably 100~600C / dm ^2. The current density at this time is preferably ²⁰ to 200 A / dm ² . The processing time is appropriately selected according to the conditions such as the amount of electricity.
In addition, the electrolyte solution, electrolytic cell, etc. which are used for this direct current | flow electrolytic surface roughening process are not specifically limited, The thing used for the electrochemical roughening process using a normal direct current can be selected.

The surface of the substrate that has been mechanically roughened by the brush grain method or the surface of the substrate that has been subjected to DC electrolytic surface roughening is subjected to an alkali etching treatment to dissolve the edge portions of the generated unevenness and smooth the sharp unevenness. It is preferable to change to a surface having a undulation.
It is also preferable to perform pickling (desmut treatment) in order to remove dirt (smut) remaining on the surface after the alkali etching treatment.
Furthermore, you may perform an anodizing process after the said roughening process.

A lithographic printing plate support having a surface roughness Ra in the above range can be obtained by the mechanical surface roughening treatment and the direct current electrolytic surface roughening treatment.
Here, when a porous layer is provided on the surface of the roughened aluminum substrate to form a lithographic printing plate support, the surface roughness Ra of the lithographic printing plate support tends to be small. Therefore, it is preferable to slightly increase the surface roughness of the roughened aluminum substrate. Specifically, the surface roughness is preferably 0.5 to 5 μm, and 0.8 to 3 μm. More preferably, it is more preferably 1 to 2 μm. When the surface roughness of the roughened aluminum substrate is adjusted to the above range, the surface roughness Ra when a porous layer is provided as a lithographic printing plate support is within the range of the present invention, 0.3 to It can be adjusted to 2 μm.

  Next, the porous layer formed by binding metal oxide particles with a compound containing a metal atom and a phosphorus atom is provided on the substrate thus roughened. The porous layer is as described above.

<Formation of sealing layer>
Further, a sealing layer is provided on the porous layer formed as described above to obtain the lithographic printing plate support of the present invention.
As a method for forming a sealing layer on the porous layer, a hydrophilic composition formed by blending the above-described components for forming the sealing layer and additives that are used together as desired may be sprayed, bar coating, etc. Can be applied to the porous layer to form a liquid film, dried by hot air at 100 to 180 ° C., and solidified.

That is, in the production method (I), specifically, the substrate is subjected to mechanical surface roughening treatment or direct current electrolytic surface roughening treatment,
A coating liquid containing a granular metal oxide and a phosphoric acid compound is applied to the roughened substrate, and the coating liquid applied to the substrate is dried by heating at 180 to 500 ° C. And further providing a sealing layer on the porous layer to obtain the lithographic printing plate support of the present invention.
In the production method (I), a lithographic printing plate support having a surface roughness Ra in the above range on the surface can be obtained by the above method.

In the method (II), a porous layer formed by binding metal oxide particles with a compound containing a metal atom and a phosphorus atom is provided on the substrate, and the porous layer is mechanically roughened. Further, a sealing layer is provided on the roughened porous layer.
In this method, first, a porous layer in which metal oxide particles are bound by a compound containing a metal atom and a phosphorus atom is provided on a substrate in the same manner as described in the production method (I). .

Next, in the production method (II), the provided porous layer is subjected to a mechanical surface roughening treatment.
At this time, the porous layer formed by applying the coating liquid for the porous layer and then drying it is difficult to be mechanically roughened due to its strong film strength. May occur or break. Therefore, when providing the porous layer, it is preferable to interrupt the drying step of the coating solution.
That is, if a mechanical surface roughening treatment is performed before the porous layer is completely solidified, cracking and breakage can be prevented, and the surface roughening treatment of the porous layer can be efficiently and reproducibly performed. Is preferable.

Here, the phrase “before the porous layer is completely solidified” is not particularly limited as long as the surface is solidified in the drying step of the porous layer. For example, when the surface of the coating solution of the porous layer is dried but the inside is not dried, and the transfer method is performed as a mechanical surface roughening treatment, the porous layer is pressed by a transfer roll. Although the pressing mold is transferred to the transfer roll, the coating liquid for the porous layer does not adhere to the transfer roll.
If the surface of the porous layer is solidified to such an extent, the film strength of the porous layer is strong, and therefore the mechanical roughening treatment can be sufficiently performed.
The drying conditions for solidifying the surface at this time cannot be determined unconditionally depending on the type of metal oxide contained in the porous layer, the thickness of the porous layer, the coating amount, the drying temperature, etc. It is experimentally determined at a time of about 15 to 70% of the drying time for completely solidifying (drying) the porous layer. Specifically, for example, when the thickness of the porous layer is 5.5 μm, it is about 30 to 90 seconds, and (after cooling) if the porous layer is not peeled off even when touched with a finger. Good. More specifically, for example, when the thickness of the porous layer made of Al ₂ O ₃ is 5.5 μm, the mechanical surface roughening treatment can be performed in about 30 seconds.

The mechanical surface roughening treatment performed in the present production method (II) is basically the same as the mechanical surface roughening treatment described in the above production method (I), and among the above, the brush grain method or The transfer method described in JP-A-7-205565 is particularly preferable.
In the above transfer method, the transfer roll used for transferring the roll pattern by bringing the porous layer into contact with the transfer roll in a state where the surface of the porous layer is dry is not limited to metal, and is made of resin or the like. Alternatively, a transfer roll coated with a general silicone resin or the like as a corrosion inhibitor or a release agent may be used.

By the mechanical roughening treatment, a lithographic printing plate support having a surface roughness Ra in the above range can be obtained.
Here, since the surface roughness Ra of the lithographic printing plate support is hardly influenced by the sealing layer thinly provided on the porous layer, the surface roughness of the porous layer obtained by the mechanical surface roughening treatment is used. The thickness may be set to the same value as the surface roughness Ra of the lithographic printing plate support.

  Next, in the production method (II), a sealing layer is provided on the porous layer that has been subjected to the mechanical roughening treatment in the same manner as described in the production method (I).

That is, in the production method (II), specifically, a coating liquid containing a granular metal oxide and a phosphoric acid compound is applied to the substrate, and the coating liquid applied to the substrate is 180. By heating and drying at ˜500 ° C., a porous layer is provided, the porous layer is mechanically roughened, and a sealing layer is provided on the roughened porous layer. This is a method for producing a lithographic printing plate support.
Here, it is preferable that the heat drying dries (solidifies) the surface of the coating solution.
In the production method (II), a lithographic printing plate support having a surface roughness Ra in the above range on the surface can be obtained by the above method.

In the method (III), a porous layer formed by binding two or more kinds of metal oxide particles having different average particle diameters with a compound containing a phosphorus atom is provided on a substrate, and the porous layer is formed on the porous layer. This is a method of providing a sealing layer.

In the production method (III), two or more kinds of metal oxide particles having different average particle diameters are used as the metal oxide particles contained in the coating liquid for the porous layer.
As described above, when two or more kinds having different average particle diameters are used as the metal oxide particles, the surface roughness Ra of the formed porous layer can be easily adjusted, and further, a roughening treatment or the like is performed. This is preferable because it is not necessary and the manufacturing cost can be reduced.

The two or more metal oxides having different average particle diameters are not particularly limited as long as they have different average particle diameters, and may be the same kind of metal oxide or different kinds of metal oxides. .
The average particle size of two or more types is not particularly limited as long as the surface roughness Ra of the porous layer can be adjusted within the above range. Depending on the use ratio (existence ratio) of these particles, etc., it cannot be determined unconditionally. For example, the average particle diameter of the first metal oxide particles is preferably 0.01 to 5 μm, and 0 More preferably, it is 0.03 to 3 μm, and further preferably 0.1 to 1.5 μm. The average particle diameter of the second metal oxide particles is preferably 2 to 50 times, preferably 3 to 20 times, and more preferably 4 to 10 times the average particle diameter of the first metal oxide particles. preferable.

  Specific examples of the metal oxide particles include the AKP series, the AKP-G series, the HIT series, the AM series (manufactured by Sumitomo Chemical Co., Ltd.), and the Nanotech series (generic names: ultrafine particles, CII Kasei Co., Ltd.). ) And other commercial products of various alumina fine particles can be used.

More specifically, the following are mentioned.
As particles of the first metal oxide, SiO ₂ (Twanalite FTB, average particle size 12 μm, manufactured by Nao Toyowa Co., Ltd.), silica sand SP-80, average particle size 5.5 μm, manufactured by Sanei Silica Co., Ltd. ), MgO (Ube Materials 2000A, average particle size 0.2 μm, manufactured by Ube Industries, Ltd.), ZrO ₂ (Nanotech series (generic name: ultrafine particles) ZrO ₂ , average particle size 0.03 μm, C-I Kasei Co., Ltd.) ), TiO ₂ (rutile, TI-0057, average particle size of 1 to 2 μm, reagent manufactured by Soekawa Richemical Co., Ltd.), SiO ₂ / Al ₂ O ₃ (Nanotech series (general name: ultrafine particle) SiO ₂ / Al ₂ O ₃ , average particle size 0.03 μm, manufactured by C.I. Kasei Co., Ltd.), MgO / Al ₂ O ₃ (Nanotech series (generic name: ultrafine particle) MgO / Al ₂ O ₃ , average particle size 0.05 μm, C.I. ( ) _{Ltd.), 2SiO 2 · 3Al 2 O} 3 ( mixed oxide mullite (powder), an average particle diameter of 0.8 [mu] m, Kyoritsu manufactured Materials Co.) and the like. These particles, particle by milling or the like, if desired Adjust the diameter for use.

Examples of the second metal oxide particles include SiO ₂ (SI-0010, average particle size 10 μm, reagent manufactured by Soekawa Richemical Co., Ltd.), MgO (MG-0076, average particle size 2 mm, manufactured by Soekawa Richemical Co., Ltd.). _{reagent), ZrO 2 (ZR-0049} , average particle size 8 [mu] m, Tenkawa Rikagaku Co., Ltd. _{reagent), 2SiO 2 · 3Al 2 O} 3 (AL-0111, average particle diameter 5 mm, Tenkawa Rikagaku Co., Ltd. reagent), etc. Is mentioned.
In addition to the above, any commercially available one can be used without particular limitation.
These particles are used after adjusting the average particle diameter by pulverization or the like, if desired.

  The pulverization method is not particularly limited as long as the average particle diameter can be adjusted. For example, using a mill such as HD A-5 pot mill (YTZ-0.2, manufactured by Nikkato Co., Ltd.), about 100 rpm. And a method of adjusting the average particle size by changing the pulverization time to 1 to 100 hours at the number of rotations.

  The production method (III) is basically the same as the method for forming a porous layer in the production method (I) except that two or more kinds of metal oxide particles having different average particle diameters are used.

  Next, in the production method (III), a sealing layer is provided on the porous layer in the same manner as described in the production method (I).

That is, in the production method (III), specifically, a coating liquid containing two or more kinds of granular metal oxides having different average particle diameters and a phosphoric acid compound is coated on the substrate, A lithographic printing plate for obtaining a support for a lithographic printing plate of the present invention by providing a porous layer by heating and drying a coating solution applied to a substrate at 180 to 500 ° C., and providing a sealing layer on the porous layer It is a manufacturing method of the support body.
In the production method (III), a lithographic printing plate support having a surface roughness Ra in the above range on the surface can be obtained by the above method.

  The lithographic printing plate support of the present invention having a surface roughness Ra in the above range thus obtained is excellent in sensitivity and excellent in printing durability, stain resistance and shiny.

  A lithographic printing plate precursor can be obtained by providing a heat-sensitive image recording layer on the lithographic printing plate support of the present invention. According to this configuration, light energy by exposure, for example, laser light used for writing can be efficiently used as thermal energy necessary for image formation, and high-sensitivity, high-resolution image formation is possible, and printability is improved. An excellent lithographic printing plate precursor can be obtained.

[Lithographic printing plate precursor]
The above-described lithographic printing plate support of the present invention can be provided with an image recording layer such as a photosensitive layer and a heat-sensitive layer exemplified below to form the lithographic printing plate precursor of the present invention.
<Image recording layer>
A photosensitive composition is used for the image recording layer used in the present invention.
Examples of the photosensitive composition suitably used in the present invention include a thermal positive photosensitive composition containing an alkali-soluble polymer compound and a photothermal conversion material (hereinafter, this composition and an image recording layer using the same). Is referred to as "thermal positive type"), a thermal negative photosensitive composition containing a curable compound and a photothermal conversion substance (hereinafter also referred to as "thermal negative type"), and a photosensitive that does not require a special development step. Composition (hereinafter also referred to as “untreated type”). Hereinafter, these suitable photosensitive compositions will be described.

[Thermal positive type]
<Photosensitive layer>
The thermal positive photosensitive composition contains a water-insoluble and alkali-soluble polymer compound (referred to as “alkali-soluble polymer compound” in the present invention) and a photothermal conversion substance. In the thermal positive type image recording layer, the photothermal conversion substance converts the energy of light such as infrared lasers into heat, and the heat efficiently cancels the interaction that reduces the alkali solubility of the alkali-soluble polymer compound. To do.

Examples of the alkali-soluble polymer compound include a resin containing an acidic group in the molecule and a mixture of two or more thereof. In particular, a phenolic hydroxy group, sulfonamide group (in -SO ₂ NH-R (wherein, R represents a hydrocarbon group.)), Active imino group _{(-SO 2 NHCOR, -SO 2 NHSO} 2 R, -CONHSO A resin having an acidic group such as ₂ R (wherein R has the same meaning as described above) is preferable in terms of solubility in an alkali developer.
In particular, a resin having a phenolic hydroxy group is preferable in that it has excellent image-forming properties when exposed to light such as an infrared laser. For example, a phenol-formaldehyde resin, m
-Cresol-formaldehyde resin, p-cresol-formaldehyde resin, m- / p-mixed cresol-formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) mixed-formaldehyde resin ( Preferable examples include novolak resins such as phenol-cresol-formaldehyde co-condensation resin.
Furthermore, the polymer compound described in JP-A No. 2001-305722 (particularly [0023] to [0042]), and the repetition represented by the general formula (1) described in JP-A No. 2001-215893 Preferred examples also include polymer compounds containing units, and polymer compounds described in JP-A No. 2002-311570 (particularly [0107]).

  Preferable examples of the photothermal conversion substance include pigments or dyes having a light absorption region in the infrared region having a wavelength of 700 to 1200 nm from the viewpoint of recording sensitivity. Examples of the dye include azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes (for example, , Nickel thiolate complex). Among these, cyanine dyes are preferable, and cyanine dyes represented by the general formula (I) described in JP 2001-305722 A are particularly preferable.

The thermal positive type photosensitive composition may contain a dissolution inhibitor. As the dissolution inhibitor, for example, dissolution inhibitors described in JP-A-2001-305722, [0053] to [0055] are preferably exemplified.
In addition, in the thermal positive type photosensitive composition, as a additive, a sensitivity modifier, a printing agent for obtaining a visible image immediately after heating by exposure, a compound such as a dye as an image colorant, a coating property In addition, it is preferable to include a surfactant for improving the processing stability. For these, compounds described in JP-A-2001-305722, [0056] to [0060] are preferable.
A photosensitive composition described in detail in JP-A No. 2001-305722 is preferably used.

Further, the thermal positive type image recording layer is not limited to a single layer but may have a two-layer structure.
As an image recording layer having a two-layer structure (multilayer image recording layer), a lower layer (hereinafter referred to as “A layer”) having excellent printing durability and solvent resistance is provided on the side close to the support, and a positive layer is provided thereon. A type provided with a layer having excellent image formability (hereinafter referred to as “B layer”) is preferable. This type has high sensitivity and can realize a wide development latitude. The B layer generally contains a photothermal conversion substance. Preferred examples of the photothermal conversion substance include the dyes described above.
As the resin used in the A layer, a polymer having a monomer having a sulfonamide group, an active imino group, a phenolic hydroxy group or the like as a copolymerization component is preferably used because it has excellent printing durability and solvent resistance. . As the resin used for the B layer, an alkaline aqueous solution-soluble resin having a phenolic hydroxy group is preferably exemplified.
In addition to the resin, the composition used for the A layer and the B layer can contain various additives as necessary. Specifically, various additives as described in JP-A-2002-323769, [0062] to [0085] are preferably used. Further, the additives described in [0053] to [0060] of JP-A-2001-305722 described above are also preferably used.
About each component which comprises A layer and B layer, and its content, it is preferable to make it describe in Unexamined-Japanese-Patent No. 11-218914.

<Intermediate layer>
An intermediate layer is preferably provided between the thermal positive type image recording layer and the support. As the component contained in the intermediate layer, various organic compounds described in [0068] of JP-A No. 2001-305722 are preferably exemplified.

<Others>
As a method for producing a thermal positive type image recording layer and a plate making method, methods described in detail in JP-A No. 2001-305722 can be used.

[Thermal negative type]
The thermal negative photosensitive composition contains a curable compound and a photothermal conversion substance. The thermal negative type image recording layer is a negative photosensitive layer in which a portion irradiated with light such as an infrared laser is cured to form an image portion.
<Polymerized layer>
As one of the thermal negative type image recording layers, a polymerization type image recording layer (polymerization layer) is preferably exemplified. The polymerization layer contains a photothermal conversion substance, a radical generator, a radical polymerizable compound that is a curable compound, and a binder polymer. In the polymerization layer, infrared light absorbed by the light-to-heat conversion substance is converted into heat, the radical generator is decomposed by this heat to generate radicals, and the radical polymerizable compound is polymerized in a chain by the generated radicals and cured. .

As a photothermal conversion substance, the photothermal conversion substance used for the thermal positive type mentioned above is mentioned, for example. Specific examples of particularly preferred cyanine dyes include those described in JP-A-2001-133969, [0017] to [0019].
Preferred examples of the radical generator include onium salts. In particular, onium salts described in JP-A-2001-133969, [0030] to [0033] are preferable.
Examples of the radical polymerizable compound include compounds having at least one terminal ethylenically unsaturated bond, preferably two or more.
As the binder polymer, a linear organic polymer is preferably exemplified. Preferred examples include linear organic polymers that are soluble or swellable in water or weak alkaline water. Among them, a (meth) acrylic resin having an unsaturated group such as an allyl group or an acryloyl group or a benzyl group and a carboxy group in the side chain is preferable in that it has an excellent balance of film strength, sensitivity, and developability. .
As the radical polymerizable compound and the binder polymer, those described in detail in [0036] to [0060] of JP-A No. 2001-133969 can be used.

  In the thermal negative photosensitive composition, an additive described in JP-A-2001-133969, [0061] to [0068] (for example, a surfactant for improving coatability) is contained. Is preferred.

  As a method for producing the polymerization layer and a plate making method, methods described in detail in JP-A No. 2001-133969 can be used.

<Acid cross-linked layer>
Further, as one of the thermal negative type image recording layers, an acid cross-linked image recording layer (acid cross-linked layer) is also preferably exemplified. The acid cross-linking layer comprises a photothermal conversion substance, a thermal acid generator, a compound that cross-links with an acid that is a curable compound (cross-linking agent), and an alkali-soluble polymer compound that can react with the cross-linking agent in the presence of an acid. contains. In the acid cross-linking layer, infrared light absorbed by the photothermal conversion substance is converted into heat, the heat acid generator is decomposed by this heat to generate an acid, and the generated acid reacts with the cross-linking agent and the alkali-soluble polymer compound. And harden.

Examples of the photothermal conversion substance include the same substances as those used for the polymerization layer.
Examples of the thermal acid generator include thermal decomposition compounds such as photoinitiators for photopolymerization, photochromic agents for dyes, and acid generators used in microresists.
Examples of the crosslinking agent include an aromatic compound substituted with a hydroxymethyl group or an alkoxymethyl group; a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group; and an epoxy compound.
Examples of the alkali-soluble polymer compound include a novolak resin and a polymer having a hydroxyaryl group in the side chain.

[Non-treatment type]
Examples of the non-processing type photosensitive composition include a thermoplastic fine particle polymer type, a microcapsule type, and a sulfonic acid-generating polymer-containing type. These are all heat-sensitive types containing a photothermal conversion substance. The photothermal conversion substance is preferably the same dye as that used in the above-described thermal positive type.

The thermoplastic fine particle polymer type photosensitive composition is obtained by dispersing a hydrophobic and heat-meltable fine particle polymer in a hydrophilic polymer matrix. In the image recording layer of the thermoplastic fine particle polymer type, the hydrophobic fine particle polymer is melted by heat generated by exposure and is fused to form a hydrophobic region, that is, an image portion.
As the fine particle polymer, those in which fine particles melt and coalesce with heat are preferable, and those having a hydrophilic surface and capable of being dispersed in a hydrophilic component such as dampening water are more preferable. Specifically, Research Disclosure No. 33303 (January 1992), JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, and JP-A-9-171250, and European Patent Application Publication No. 931,647. Preferred examples thereof include thermoplastic fine particle polymers. Of these, polystyrene and polymethyl methacrylate are preferred. Examples of the fine particle polymer having a hydrophilic surface include those in which the polymer itself is hydrophilic; those in which a hydrophilic compound such as polyvinyl alcohol and polyethylene glycol is adsorbed on the surface of the fine particle polymer to make the surface hydrophilic.
The fine particle polymer preferably has a reactive functional group.

  As a microcapsule type photosensitive composition, a compound having a heat-reactive functional group as described in JP-A No. 2000-118160 or JP-A No. 2001-277740 is included. A microcapsule type is preferable.

  Examples of the sulfonic acid generating polymer used in the sulfonic acid generating polymer-containing photosensitive composition include sulfonic acid ester groups, disulfone groups, and sec- or tert-sulfonamides described in JP-A No. 10-282672. Examples thereof include polymers having a group in the side chain.

  By incorporating a hydrophilic resin into the unprocessed photosensitive composition, not only on-press developability is improved, but also the film strength of the photosensitive layer itself is improved. Examples of the hydrophilic resin include those having a hydrophilic group such as hydroxy group, carboxy group, hydroxyethyl group, hydroxypropyl group, amino group, aminoethyl group, aminopropyl group, carboxymethyl group, and hydrophilic sol-gel conversion system. A binder resin is preferred.

  The unprocessed type image recording layer does not require a special development step and can be developed on a printing press. As a method for producing an unprocessed image recording layer and a plate-making printing method, methods described in detail in JP-A No. 2002-178655 can be used.

<Overcoat layer>
In the lithographic printing plate precursor according to the invention, a water-soluble overcoat layer can be provided on the image recording layer in order to prevent contamination of the image recording layer surface with an oleophilic substance. The water-soluble overcoat layer used in the present invention is preferably one that can be easily removed during printing, and contains a resin selected from water-soluble organic polymer compounds.
As the water-soluble organic polymer compound, a film formed by coating and drying has film-forming ability. Specifically, for example, polyvinyl acetate (however, a hydrolysis rate of 65% or more), polyacrylic Acid and its alkali metal salt or amine salt, polyacrylic acid copolymer and its alkali metal salt or amine salt, polymethacrylic acid and its alkali metal salt or amine salt, polymethacrylic acid copolymer and its alkali metal salt or amine Salt, polyacrylamide and copolymer thereof, polyhydroxyethyl acrylate, polyvinylpyrrolidone and copolymer thereof, polyvinyl methyl ether, polyvinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamide-2-methyl-1- Propanesulfonic acid and its al Li metal salt or amine salt, poly-2-acrylamido-2-methyl-1-propanesulfonic acid copolymer and its alkali metal salt or amine salt, gum arabic, fiber derivative (for example, carboxymethyl cellulose, carboxyethyl cellulose) , Methyl cellulose, etc.) and modified products thereof, white dextrin, pullulan, enzymatically-decomposed etherified dextrin, and the like. Further, two or more kinds of these resins can be mixed and used depending on the purpose.

Moreover, you may add a water-soluble thing among the above-mentioned photothermal conversion agents to an overcoat layer. Furthermore, for the purpose of ensuring the uniformity of coating, a nonionic surfactant such as polyoxyethylene nonylphenyl ether or polyoxyethylene dodecyl ether can be added to the overcoat layer in the case of aqueous solution coating. .
The dry coating amount of the overcoat layer is preferably 0.1 to 2.0 g / m ² . Within this range, the on-press developability is not impaired, and the surface of the image recording layer can be satisfactorily prevented from being contaminated with lipophilic substances such as fingerprint adhesion stains.

<Back coat>
In this way, the image recording layer in the case of being overlaid on the back surface of the lithographic printing plate precursor of the present invention obtained by providing various image recording layers on the lithographic printing plate support of the present invention, if necessary. In order to prevent scratching, a coating layer made of an organic polymer compound can be provided.

<Method for producing planographic printing plate precursor>
Each layer such as an image recording layer can usually be produced by applying a coating solution obtained by dissolving the above components in a solvent onto a lithographic printing plate support.
Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, toluene, water and the like. However, the present invention is not limited to these. These solvents are used alone or in combination.
The concentration of the above components (total solid content) in the solvent is preferably 1 to 50% by mass.

  Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

[Plate making method (lithographic printing plate production method)]
The lithographic printing plate precursor using the lithographic printing plate support of the present invention is converted into a lithographic printing plate by various treatment methods according to the image recording layer.
Examples of the actinic ray light source used for image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, and a chemical lamp. Examples of the laser beam include a helium-neon laser (He-Ne laser), an argon laser, a krypton laser, a helium-cadmium laser, a KrF excimer laser, a semiconductor laser, a YAG laser, and a YAG-SHG laser.

When the image recording layer is of the thermal positive type or the thermal negative type after the exposure, it is preferable to obtain a lithographic printing plate by developing with a developer after the exposure.
The developer is preferably an alkaline developer, and more preferably an alkaline aqueous solution substantially free of an organic solvent.
A developer containing substantially no alkali metal silicate and containing a saccharide (a developer containing substantially no alkali metal silicate) is also preferred. As a method of developing using a developer substantially not containing an alkali metal silicate, a method described in detail in JP-A No. 11-109637 can be used.
A developer containing an alkali metal silicate can also be used.

When using the processing method of a lithographic printing plate precursor developed using a developer containing substantially no alkali metal silicate, there is a problem when developing using a developer containing an alkali metal silicate, the solids resulting from the SiO ₂ is likely to precipitate, it is possible to prevent the occurrence of problems such as the gel due to SiO ₂ in the neutralization process when processing waste of the developing solution is produced.

  The lithographic printing plate precursor of the present invention is a lithographic printing plate comprising the above-mentioned image recording layer on a lithographic printing plate support provided with the porous layer of the present invention having high film strength and excellent scratch resistance and heat insulation. Since it is an original plate, it has excellent sensitivity, and has excellent stain resistance and printing durability when used as a lithographic printing plate. Furthermore, the lithographic printing plate support, lithographic printing plate precursor and lithographic printing plate of the present invention can reduce production costs.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

1. Preparation of lithographic printing plate support <Preparation of porous layer coating solution>
Each coating liquid C-1 to C-14 having the composition shown in Table 1 was prepared by the following method.
That is, 0.1 g of citric acid as a dispersant was added to an appropriate amount of water, and after stirring for a while, the metal oxide shown in Table 1 was added according to the usage amount (g) shown in the table, and an ultrasonic dispersion device ( The metal oxide was uniformly dispersed in about 10 minutes using an ultrasonic homogenizer, VC-130, manufactured by SONICS Co., Ltd.) and a homogenizer (Auto Cell Master, CM-200, manufactured by ASONE Co., Ltd.).
Thereafter, the phosphoric acid compound and the reaction accelerator shown in Table 1 were respectively added according to the usage amounts shown in the table, and further water was added to adjust the mass of the entire coating solution to 100 g, and each coating solution C-1 -C-14 was obtained.

As the metal oxides shown in Table 2, commercially available products were used as they were or after pulverization to adjust the average particle diameter.
Specifically, “MgO” used for the coating liquids C-1 and C-2 was Ube Materials 2000A (average particle size 0.2 μm, manufactured by Ube Industries, Ltd.).
“SiO ₂ ” of the coating liquids C-3 to C-6 was prepared by pulverizing Towanalite FTB (average particle size: 12 μm, manufactured by Naoya Howa, Shirasu Balloon) by the following method. The average particle size was adjusted to 0.3 μm.
As the “ZrO ₂ ” of the coating liquids C-7 and C-8, Nanotech series (generic name: ultrafine particle) ZrO ₂ (average particle size: 0.03 μm, manufactured by CI Kasei Co., Ltd.) was used.
“SiO ₂ / Al ₂ O ₃ ” of the coating liquids C-9 and C-10 is a nanotech series (generic name: ultrafine particle) SiO ₂ / Al ₂ O ₃ (mixed oxide having an average particle size of 0.03 μm, C eye Kasei Co., Ltd.) was used.
“MgO / Al ₂ O ₃ ” of the coating liquids C-11 and C-12 is a nanotech series (generic name: ultrafine particles) MgO / Al ₂ O ₃ (mixed oxide having an average particle size of 0.05 μm, CII Chemical ( Product).
“3Al ₂ O ₃ .2SiO ₂ ” used for coating liquids C-13 and C-14 is obtained by pulverizing mullite (powder) (composite oxide, average particle size 0.8 μm, manufactured by Kyoritsu Materials Co., Ltd.) The average particle size of the composite oxide after pulverization was adjusted to 0.3 μm.
Reagents manufactured by Kanto Chemical Co., Inc. were used for phosphoric acid, sodium dihydrogen phosphate (NaH ₂ PO ₄ ), citric acid, sodium fluoride, zirconium phosphate, aluminum phosphate and aluminum chloride.

The pulverization of the SiO ₂ and 3Al ₂ O ₃ .2SiO ₂ uses a mill such as HD A-5 pot mill (YTZ-0.2, manufactured by Nikkato Co., Ltd.) and the like, and the pulverization time is 1 at a rotation speed of about 100 rpm. The average particle size was adjusted by changing to ~ 100 hours.

In addition, the amount of metal oxide used in each coating solution was adjusted by calculating the amount of reaction with a phosphoric acid compound (ie, the amount of a compound containing a metal atom and a phosphorus atom) with a constant amount by the following formula. .
The average particle radius of the MgO particles in the coating liquid C-1 is r ₁ density d ₁ , the mass is W ₁ , the average particle radius of the metal oxide particles in the coating liquids C-3 to C-14 is r ₂ , and the density is The amount of the metal oxide particles used in the coating liquids C-3 to C-14 was calculated from the following formula using d ₂ and a mass of W ₂ .
W ₂ = [(r ₂ × d ₂ ) / (r ₁ × d ₁ )] × W ₁
The amount of the phosphoric acid compound used is adjusted so that the number of moles of acidic protons (number of moles of phosphorus compound used × valence) is constant in the coating liquids C-4 and C-6 to C-14. In the coating liquids C-3 and C-5, the amount used was changed to the amount shown in Table 1.

<Production of substrate>
(Aluminum substrate AL-1)
A 0.24 mm thick aluminum plate (JIS1050 (manufactured by Sumitomo Light Metal Co., Ltd.)) was immersed in a caustic soda aqueous solution (concentration 26%) at a liquid temperature of 70 ° C. for 10 seconds, washed with water, and further sulfuric acid at a liquid temperature of 60 ° C. It was immersed in (concentration 36%) for 60 seconds, washed with water, and subjected to alkali degreasing treatment to obtain an aluminum substrate AL-1.

(Stainless steel substrates SUS1 to SUS3)
A thickness of 0.24 mm stainless steel (SUS304 material (manufactured by Nippon Yakin Kogyo Co., Ltd.)) was sputtered using a sputtering apparatus (model SRV4310, manufactured by Shinko Seiki Co., Ltd.) under the following condition 1 to obtain a film thickness. A 50 nm thin SiO ₂ layer was provided to obtain a stainless steel substrate SUS1.
A stainless steel substrate SUS2 was obtained in the same manner as described above except that sputtering was performed under condition 2 to provide an MgO thin layer having a thickness of 50 nm.
A stainless steel substrate SUS3 was obtained in the same manner as described above except that sputtering was performed under condition 3 to provide a ZrO thin layer having a thickness of 50 nm.

(Condition 1) Ultimate pressure 5 × 10 ⁻⁴ Pa, sputtering pressure 6.7 × 10 ⁻¹ Pa, argon flow rate 20 sccm, substrate unheated, no substrate cooling, no bias, sputtering power supply RF, sputtering power 0.5 kW, pre Sputtering time 5 minutes, sputtering time 5 minutes, no reactive sputtering, no reverse sputtering, target SiO ₂
(Condition 2) Ultimate pressure 5 × 10 ⁻⁴ Pa, sputtering pressure 6.7 × 10 ⁻¹ Pa, argon flow rate 20 sccm, substrate unheated, no substrate cooling, no bias, sputtering power supply RF, sputtering power 1.0 kW, pre Sputtering time 5 minutes, sputtering time 10 minutes, reactive sputter oxygen 1 × 10 ⁻³ Pa, no reverse sputtering, target MgO
(Condition 3) Ultimate pressure 5 × 10 ⁻⁴ Pa, sputtering pressure 6.7 × 10 ⁻¹ Pa, argon flow rate 20 sccm, substrate unheated, no substrate cooling, no bias, sputtering power source RF, sputtering power 2.0 kW, pre Sputtering time 5 minutes, sputtering time 6 minutes, no reactive sputtering, no reverse sputtering, target ZrO

Note that the thickness of the thin layer formed by sputtering is determined by an atomic force microscope (Atomic).
The time was adjusted using the correlation calibration curve of the time and the film thickness obtained by measuring each film thickness with Force Microscope (AFM), and it adjusted to the desired value.

<Preparation of lithographic printing plate support>
With the combination of the substrate and the coating solution shown in Table 2, the coating solution is applied to the substrate with a commercially available wire bar so that the dry film thickness becomes the film thickness shown in Table 2, and dried at the drying temperature shown in Table 2. Thus, a porous layer was formed.
In Invention Examples 1-6 and 1-7, the formation of the porous layer was repeated twice and three times to form two and three porous layers having the thicknesses shown in Table 2. The thickness of each of the superimposed layers was almost the same.

The adjustment of the thickness of the porous layer, changing the wire diameter of the commercially available wire bar to 1.6 hole (coating weight of about 3 cc / m ²⁾ from 28 th (coating weight of about 53cc / m ²⁾ The wire thickness was selected to obtain a desired film thickness.
In addition, although the drying time varies depending on the film thickness (μm) of the porous layer, it is a time calculated by 30 seconds + 20 seconds × (film thickness−1) as a guide. Specifically, when the film thickness was 5.5 μm, it was 30 + 20 × (5.5-1) = 120 seconds.

Subsequently, on the porous layer formed as described above, a sealing layer coating solution having the following composition was applied with a commercially available wire bar so that the dry film thickness was as shown in Table 2, Drying (temperature 120 ° C., 2 minutes) was performed to form a sealing layer, and a lithographic printing plate support of the present invention was obtained.
In addition, in Invention Example 1-1 and Comparative Example 1-1, the sealing layer was not formed.
(Composition of sealing layer coating solution)
・ No. 3 sodium silicate (reagent manufactured by Kanto Chemical Co., Inc.) 10g as silicate
・ Almatex E269 (emulsion resin, hydrophilic resin)
Mitsui Chemicals Co., Ltd.) 0.4g
・ Water 50g

[Comparative Examples 1-1 to 1-3]
<Preparation of lithographic printing plate support>
An anodic oxide film was directly formed on the aluminum substrate AL-1 by the following method without subjecting the aluminum substrate AL-1 subjected to the degreasing treatment similar to the above-described example of the present invention to a roughening treatment.
That is, a sulfuric acid aqueous solution having a sulfuric acid concentration of 15% by mass (containing 0.5% by mass of aluminum ions) and a temperature of 38 ° C. was used as the electrolytic solution. Continuous direct current electrolysis was performed so that the final oxide film amount was the film thickness shown in Table 2.
In addition, since the coating liquid was not used for formation of the anodized film, the columns of “Coating liquid” and “Drying temperature” in Table 2 are indicated by “−”. In Table 2, the thickness of the anodic oxide film is shown in the column “Positive layer thickness”. The film thickness of the anodized film was measured by a generally used method. The porosity of the anodized film was not measured. In Table 2, “-” is shown in the column “Porosity of porous layer”.

2. Evaluation of porous layer and sealing layer <Porosity of porous layer>
The porosity of the porous layer was determined from the thickness of the porous layer shown in Table 2 and the mass of the porous layer after drying.
Specifically, the density was calculated by the following formula from the film thickness of the porous layer and the film mass per unit area.
Density (g / cm ³ ) = (film mass per unit area / film thickness)
Using the calculated density, the porosity was determined according to the following formula.
Porosity (%) = {1− (density of porous layer / D)} × 100
Here, D is the density (g / cm ³ ) according to the chemical handbook of the metal oxide used for forming the porous layer.
The film mass per unit area of the porous layer was measured by the so-called Mason method. The film thickness of the porous layer shown in Table 2 is a value measured by observing the film thickness with an ultrahigh resolution scanning electron microscope at the magnification shown below.
When the film thickness was 1 μm or less, the magnification was 10,000 times, when the film thickness was 1 to 5 μm, the magnification was 3000 times, and when the film thickness was 5 μm or more, the magnification was 100 to 3000 times.

<Porosity of sealing layer>
The measurement of the porosity of the sealing layer was carried out by using the lithographic printing plate support obtained in Examples 1-2 to 1-25 of the present invention to bend the fractured surface prepared by bending the fracture surface, using an ultrahigh resolution scanning electron microscope. (S-900, manufactured by Hitachi, Ltd.) was observed and photographed at a magnification of 50,000 times. In the range of 3 cm × 3 cm of the obtained image data (photograph), no void portion was observed in any of the lithographic printing plate supports, so the porosity was set to “0%” and shown in Table 2.
In addition, the porosity of the sealing layer of Comparative Examples 1-2 and 1-3 was not measured. “-” Is shown in the column “Porosity of Sealing Layer” in Table 2.

<Scratch resistance>
About the porous layer or anodic oxide film of each lithographic printing plate support obtained in Invention Examples 1-1 to 1-25 and Comparative Examples 1-1 to 1-3, the scratch resistance was obtained by the following method. evaluated. The results are shown in Table 2.
That is, the porous layers or anodic oxide films of the present invention examples and comparative examples were evaluated by scratch tests.
The scratch test was performed using a continuous load-type scratch strength tester SB62 TYPE18 (manufactured by Shinto Kagaku Co., Ltd.) under the conditions of a sapphire needle of 0.4 mmφ and a needle moving speed of 10 cm / sec. , 25 g, 30 g, 50 g, 80 g, 100 g, and 150 g. The evaluation was performed with a weight value in which scratches were observed in the porous layer or the anodized film.
“AA” when the weight is 50 g or more, “A” when 30 g, “B” when 25 g, “C” when 20 g, “E” when 10 g. It showed in.

2. Preparation of lithographic printing plate precursor Photosensitive solution coating having the following composition on each of the lithographic printing plate supports obtained in Examples 1-1 to 1-25 and Comparative Examples 1-1 to 1-3 of the invention. After the liquid was applied so that the coating amount after drying was 1.0 g / m ² , the Wind Control was set to 7 with a TARFAI, PERFECT OVEN PH200, dried at 140 ° C. for 50 seconds, and the planographic printing plate I got the original version.

(Composition of photosensitive solution coating solution)
・ M, p-cresol novolak (m / p ratio = 6/4, weight average molecular weight 3500, containing 0.5% by mass of unreacted cresol) 0.427 g
-Siloxane structure-containing alkali-soluble resin (F-1) obtained by the following synthesis method 0.047 g
・ Specific copolymer 1 2.37 g described in JP-A-11-288093
-Cyanine dye A 0.155 g represented by the following formula
・ 2-Methoxy-4- (N-phenylamino) benzene 0.03 g
・ Diazonium hexafluorophosphate tetrahydrophthalic anhydride 0.19 g
・ The counter ion of ethyl violet was changed to 6-hydroxy-β-
0.05 g of naphthalene sulfonic acid
・ Fluorine surfactant (Megafac F-176PF,
Dainippon Ink & Chemicals, Inc.) 0.035g
・ Fluorine surfactant (Megafac MCF-312,
Dainippon Ink & Chemicals, Inc.) 0.05g
・ 0.008 g of p-toluenesulfonic acid
・ Bis-p-hydroxyphenylsulfone 0.063 g
・ Stearic acid n-dodecyl 0.06g
・ Γ-Butyrolactone 13g
・ Methyl ethyl ketone 24g
・ 11g of 1-methoxy-2-propanol

(Synthesis of siloxane structure-containing alkali-soluble resin (F-1))
120 g of cresol novolak (m / p ratio = 6/4, weight average molecular weight = 5200) was dissolved in 400 mL of methanol, 5.4 g of sodium methoxide was added, and the mixture was stirred for 30 minutes. Methanol was distilled off under reduced pressure, 400 mL of tetrahydrofuran was added, and the solvent was replaced. 17 g of epoxy-type terminal-reactive silicone MCR-E11 (manufactured by Chisso Corporation) was added, and the mixture was heated to reflux for 6 hours. The reaction solution was cooled to room temperature, poured into 8000 mL of water, and the separated product was collected by filtration, washed with water, and dried to obtain 132 g of a siloxane structure-containing alkali-soluble resin (F-1).

3. Evaluation of planographic printing plate precursor and planographic printing plate <Measurement of clear sensitivity>
Each lithographic printing plate precursor obtained as described above was output and exposed under a condition of resolution of 2400 dpi using a Creo Trendsetter 3244VFS equipped with a water-cooled 40 W infrared semiconductor laser. At this time, the plate surface energy was changed by changing the rotational speed of the outer drum.

After the image exposure, Fuji Photo was loaded with Fuji Photo Film Co., Ltd. developer DT-1 (diluted 1: 8) and Fuji Photo Film Co., Ltd. finisher FP2W (diluted 1: 1). Using a PS processor 900H manufactured by Film Co., Ltd., development was performed at a liquid temperature of 30 ° C. and a development time of 12 seconds (the electric conductivity of the developer at this time was 45 mS / cm).
Sensitivity was evaluated based on the minimum exposure amount at which development was satisfactorily performed without contamination and coloring due to the residual film of the poorly developed image recording layer. Table 2 shows the exposure amount at that time.
The smaller the exposure amount, the better the sensitivity of the lithographic printing plate precursor.

<Stain resistance>
The lithographic printing plate precursor obtained above was imaged using a TrendSetter manufactured by Creo at a drum rotation speed of 150 rpm and a beam intensity of 10 W.
Printing using a lithographic printing plate obtained by developing as in the case of the above clear sensitivity evaluation, using a DIC-GEOS (s) red ink on a Mitsubishi Diamond F2 printer (manufactured by Mitsubishi Heavy Industries). After printing 50 sheets, the printing press is temporarily stopped, the blanket portion of the printing press is copied with Nitto Denko's PET tape, and the non-image portion is stained with ink visually according to the following criteria. evaluated. The results are shown in Table 2.

  The evaluation criteria are “AA” when the occurrence of dirt cannot be confirmed at all, “A” when the occurrence of dirt can hardly be confirmed, “B” when the occurrence of dirt can be confirmed a little, and when the occurrence of dirt is significant. “D”, and “E” when the occurrence of smudges covers the entire non-image area.

<Print durability>
Using a planographic printing plate obtained by the same method as in the above evaluation of <stain resistance>, it was measured how many prints without residual color, residual film and stain were obtained under the same printing conditions. That is, when any one of the remaining color, the remaining film, and the stain is below the allowable level of the printed material, the printing is completed, and the number of printed sheets at that time is defined as the number of printed sheets.
As a result, in any of the examples of the present invention, the number of completed sheets is equal to or greater than the number of completed sheets of the comparative example, and the planographic printing plate of the present example of the invention has excellent printing durability equal to or greater than the planographic printing plate of the comparative example. Sex was obtained.

As is apparent from Table 2, the porous layer of the present invention has a film strength equivalent to that of the anodized film. The lithographic printing plate precursor produced from the porous layer, preferably a lithographic printing plate support provided with a sealing layer on the porous layer, is provided with a lithographic printing plate support provided with an anodized film. Excellent sensitivity equal to or better than that of a lithographic printing plate precursor produced from Furthermore, the support for a lithographic printing plate comprising a porous layer, preferably a sealing layer provided on the porous layer, is excellent in stain resistance and printing durability when used as a lithographic printing plate.
In addition, even when an aluminum substrate is used as the substrate, the porous layer can be formed at a relatively low temperature (below the softening temperature of aluminum). I couldn't.
Furthermore, the lithographic printing plate support provided with the porous layer of the present invention is excellent in all of scratch resistance, sensitivity, stain resistance and printing durability, even if it is prepared using various substrates. .

1. Preparation of Porous Layer Coating Solution Each coating solution C-1 to C-8 having the composition shown in Table 3 was prepared by the following method.
That is, 0.1 g of citric acid as a dispersant was added to an appropriate amount of water, and after stirring for a while, the metal oxides shown in Table 3 were added according to the usage amount (g) shown in the table, and an ultrasonic dispersion device ( The metal oxide was uniformly dispersed in about 10 minutes using an ultrasonic homogenizer, VC-130, manufactured by SONICS Co., Ltd.) and a homogenizer (Auto Cell Master, CM-200, manufactured by ASONE Co., Ltd.).
Thereafter, the phosphoric acid compound and the reaction accelerator shown in Table 3 were respectively added according to the usage amounts shown in the table, and further water was added to adjust the mass of the entire coating solution to 100 g, and each coating solution C-1 -C-8 was obtained.

As the metal oxides shown in Table 4, commercially available products were used as they were or after pulverization to adjust the average particle diameter.
Specifically, AKP-50 (average particle size 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.) was used as “Al ₂ O ₃ ” of the coating liquid C-1.
As the “MgO” of the coating liquid C-2, Ube Materials 2000A (average particle size 0.2 μm, manufactured by Ube Industries, Ltd.) was used.
As the “ZrO ₂ ” of the coating liquid C-3, Nanotech series (generic name: ultrafine particle) ZrO ₂ (average particle size: 0.03 μm, manufactured by CI Chemical Co., Ltd.) was used.
“SiO ₂ ” used for the coating liquid C-4 is obtained by crushing Tonalite FTB (average particle size 12 μm, manufactured by Nao Toyawa Co., Ltd., Shirasu Balloon) by the following method, and the average particle size of the metal oxide after the crushing Was adjusted to 0.3 μm.
“SiO ₂ / Al ₂ O ₃ ” of coating solution C-5 is a nanotech series (generic name: ultrafine particles) SiO ₂ / Al ₂ O ₃ (mixed oxide having an average particle size of 0.03 μm, CII Chemical Co., Ltd.) Made).
“MgO / Al ₂ O ₃ ” of the coating liquid C-6 is a nanotech series (general name: ultrafine particles) MgO / Al ₂ O ₃ (mixed oxide having an average particle size of 0.05 μm, manufactured by C-I Kasei Co., Ltd.) Was used.
“3Al ₂ O ₃ .2SiO ₂ ” used for the coating liquid C-7 is obtained by pulverizing mullite (powder) (composite oxide, average particle size 0.8 μm, manufactured by Kyoritsu Material Co., Ltd.) by the following method. The average particle size of the mixed oxide after pulverization was adjusted to 0.3 μm.
The product name anatase TiO ₂ (average particle size 0.05 μm, reagent manufactured by Wako Pure Chemical Industries, Ltd., amorphous) was used as “TiO ₂ ” of the coating liquid C-8.
As for phosphoric acid, citric acid, sodium fluoride (NaF), zirconium phosphate, aluminum phosphate and aluminum chloride, reagents manufactured by Kanto Chemical Co., Inc. were used.

The pulverization of the SiO ₂ and 3Al ₂ O ₃ .2SiO ₂ uses a mill such as HD A-5 pot mill (YTZ-0.2, manufactured by Nikkato Co., Ltd.) and the like, and the pulverization time is 1 at a rotation speed of about 100 rpm. The average particle size was adjusted by changing to ~ 100 hours.

In addition, the amount of metal oxide used in each coating solution was adjusted by calculating the amount of reaction with a phosphoric acid compound (ie, the amount of a compound containing a metal atom and a phosphorus atom) with a constant amount by the following formula. .
The average particle radius of the Al ₂ O ₃ particles in the coating liquid C-1 is r ₁ density d ₁ , the mass is W _1, and the average particle radius of the metal oxide particles in the coating liquids C-2 to C-8 is r _2. The amount of the metal oxide particles used in the coating liquids C- ₂ to C-8 was calculated from the following formula, with the density d ₂ and the mass W ₂ .
W ₂ = [(r ₂ × d ₂ ) / (r ₁ × d ₁ )] × W ₁

2. Fabrication of substrate <Aluminum substrate AL-1>
An aluminum plate having a thickness of 0.24 mm (JIS1050 material (manufactured by Sumitomo Light Metal Co., Ltd.))
The aluminum substrate AL-1 was immersed in a caustic soda aqueous solution (concentration 26 mass%) at a liquid temperature of 70 ° C. for 10 seconds and then washed with water, and further immersed in sulfuric acid (concentration 36%) at a liquid temperature of 60 ° C. for 60 seconds. Was made.

<Aluminum substrate AL-2>
An aluminum substrate AL-2 was produced by the following method using the aluminum substrate AL-1.
Using an apparatus as schematically shown in FIG. 1, an aqueous suspension (specific gravity 1.1 g / cm ³ ) of alumina powder (A-25, manufactured by Sumitomo Chemical Co., Ltd., median particle size 50 μm) is prepared. While supplying the polishing slurry to the surface of the substrate AL-1, a mechanical roughening treatment was performed with a rotating rotary brush. In FIG. 1, 1 is a substrate, 2 and 4 are rotating brushes, 3 is a polishing slurry, and 5, 6, 7 and 8 are support rollers.

The rotating brush was made of 6 · 10 nylon, and a No. 18 nylon brush with a bristle diameter of 0.72 mm and a length of 60 mm was drilled in a stainless steel cylinder having a diameter of 400 mm and planted.
Although only two rotating brushes are shown in FIG. 1, four are actually used (the brushes are first, second, third, fourth in order from the upstream side of the substrate transport direction). . The distance between the surfaces of the two support rollers (φ250 mm) under the brush was 300 mm.
The load of the drive motor that rotates the rotating brush was pressed down to 2.5 kW plus in all the first to fourth lines with respect to the load before the rotating brush was pressed against the substrate. The rotation direction of the rotating brush was the same as the substrate moving direction in the first and fourth lines, and the second and third lines were opposite. The number of rotations of the rotating brush was 300 rpm for the first to fourth ones.
The wrap angle between each brush and the substrate was about 30 °.
The moving speed of the substrate was 75 m / min.

<Aluminum substrate AL-3>
An aluminum substrate AL-3 was produced by the following method using the aluminum substrate AL-1.
The aluminum substrate AL-1 was continuously subjected to electrochemical surface roughening using direct current. The electrolytic solution at this time was a 10.5 g / L aqueous solution of nitric acid (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions) at a liquid temperature of 50 ° C. Electrochemical roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the current peak value, and the electricity at the time of anode was 200 C / dm ² .

<Aluminum substrate AL-4>
An aluminum substrate AL-4 was produced by the following method using the aluminum substrate AL-1.
After polishing the surface of a SUS steel roll and mirror finishing with a maximum roughness of 0.03 μm, a YAG laser processing machine with a rated output of 10 W is used to perform groove processing with a vertical groove width of 5 μm, a horizontal groove width of 5 μm, and a groove interval of 10 μm. A transfer roller was obtained by providing a plurality of independent convex portions of 5 μm square. Using this transfer roller, transfer was performed on the aluminum substrate AL-1 under the conditions of a linear pressure drop force of 10 kg / mm and a transfer count of 1 time. The area ratio of the recesses by the transfer was 28%.

<Aluminum substrate AL-5>
A commercially available mirror-finished aluminum plate (mirror finish, trade name XL (manufactured by Sumitomo Light Metal Co., Ltd.) plate thickness 0.3 μm, purity 99.3%) was used.

<Stainless steel substrates SUS1 and SUS2>
A thickness of 0.24 mm stainless steel (SUS304 material (manufactured by Nippon Yakin Kogyo Co., Ltd.)) was sputtered using a sputtering apparatus (model SRV4310, manufactured by Shinko Seiki Co., Ltd.) under the following condition 1 to obtain a film thickness. A 50 nm thin SiO ₂ layer was provided to obtain a stainless steel substrate SUS2.
A stainless steel substrate SUS1 was obtained in the same manner as described above except that sputtering was performed under condition 2 to provide a ZrO thin layer having a thickness of 50 nm.

(Condition 1) Ultimate pressure 5 × 10 ⁻⁴ Pa, sputtering pressure 6.7 × 10 ⁻¹ Pa, argon flow rate 20 sccm, substrate unheated, no substrate cooling, no bias, sputtering power supply RF, sputtering power 0.5 kW, pre Sputtering time 5 minutes, sputtering time 5 minutes, no reactive sputtering, no reverse sputtering, target SiO ₂
(Condition 2) Ultimate pressure 5 × 10 ⁻⁴ Pa, sputtering pressure 6.7 × 10 ⁻¹ Pa, argon flow rate 20 sccm, substrate unheated, no substrate cooling, no bias, sputtering power supply RF, sputtering power 2.0 kW, pre Sputtering time 5 minutes, sputtering time 6 minutes, no reactive sputtering, no reverse sputtering, target ZrO

Note that the thickness of the thin layer formed by sputtering is determined by an atomic force microscope (Atomic).
The time was adjusted using the correlation calibration curve of the time and the film thickness obtained by measuring each film thickness with Force Microscope (AFM), and it adjusted to the desired value.

3. Preparation of lithographic printing plate support <Invention Examples 2-1 to 2-3 and Invention Examples 2-6 to 2-12>
With the combination of the substrate and the coating solution shown in Table 4, the coating solution was applied to the substrate with a commercially available wire bar so that the dry film thickness of the porous layer was the film thickness shown in Table 4, and shown in Table 4 The porous layer was formed by drying at the drying temperature.

The adjustment of the thickness of the porous layer, changing the wire diameter of the commercially available wire bar to 1.6 hole (coating weight of about 3 cc / m ²⁾ from 28 th (coating weight of about 53cc / m ²⁾ The wire thickness was selected to obtain a desired film thickness.
The drying time was 120 seconds regardless of the thickness of the porous layer.

Subsequently, on the porous layer formed above, a sealing layer coating liquid having the following composition was applied with a commercially available wire bar so that the dry film thickness was as shown in Table 4, Drying (temperature: 120 ° C., 2 minutes) to form a sealing layer, and lithographic printing plate supports of Invention Examples 2-1 to 2-3 and Invention Examples 2-6 to 2-12 were obtained. .
(Composition of sealing layer coating solution)
・ No. 3 sodium silicate (reagent manufactured by Kanto Chemical Co., Inc.) 10g as silicate
・ Almatex E269 (emulsion resin, hydrophilic resin)
Mitsui Chemicals Co., Ltd.) 0.4g
・ Water 50g

<Invention Example 2-4>
A porous layer was formed in the same manner as in Invention Example 2-1. The drying was performed at a drying temperature of 180 ° C. for 30 seconds to solidify the surface of the porous layer.
The porous layer was subjected to a mechanical surface roughening process (brush grain method) under the same method and conditions as the aluminum substrate AL-2 to roughen the surface of the porous layer.
Thereafter, in order to solidify the inside of the porous layer, it was dried at a drying temperature of 180 ° C. for 90 seconds to form a porous layer.
Subsequently, a sealing layer was formed on the porous layer formed as described above in the same manner as in Invention Example 2-1, to obtain a lithographic printing plate support of Invention Example 2-4.

<Invention Example 2-5>
In the same manner as in Example 2-1 of the present invention, a porous layer having a dry film thickness of 5.5 μm was formed. The drying was performed at a drying temperature of 180 ° C. for 60 seconds to solidify the surface of the porous layer.
Thereafter, a transfer roller was prepared in the same manner as the transfer roller used for the production of the aluminum substrate AL-4, and transfer was performed on the surface of the porous layer under the conditions of linear pressure reduction force: 100 g / mm and the number of transfers: one time. went. The area ratio of the recesses formed by the transfer was 40%.
Subsequently, a sealing layer was formed on the porous layer formed as described above in the same manner as in Example 2-1 of the present invention to obtain a lithographic printing plate support of Example 2-5 of the present invention.

<Comparative Example 2-1>
An anodized film was formed on the aluminum substrate AL-2 by the following method to obtain a lithographic printing plate support of Comparative Example 2-1.
That is, a sulfuric acid aqueous solution having a sulfuric acid concentration of 15% by mass (containing 0.5% by mass of aluminum ions) and a temperature of 38 ° C. was used as the electrolytic solution. Continuous direct current electrolysis was performed so that the final oxide film amount was 5.5 μm.

<Comparative Example 2-2>
On the anodic oxide film of the lithographic printing plate support obtained in Comparative Example 2-1, a sealing layer was formed in the same manner as in Invention Example 2-1, and the lithographic printing plate support of Comparative Example 2-2. Got.

<Comparative Example 2-3>
An anodized film was formed on the aluminum substrate AL-2 in the same manner as in Comparative Example 2-1, except that continuous direct current electrolysis was performed so that the film thickness of the anodized film was 0.8 μm. Subsequently, a sealing layer was formed on the anodized film in the same manner as in Example 2-1 of the present invention to obtain a lithographic printing plate support of Comparative Example 2-3.

In Comparative Examples 2-1 to 2-3, no coating solution was used to form the anodic oxide film, so in Table 4, the columns “Coating solution” and “Drying temperature” were indicated by “−”. In Table 4, the thickness of the anodic oxide film is shown in the column “Positive layer thickness”. Since the porosity of the anodized film was not measured, it was indicated by “−” in the column “Porosity of porous layer”.
The film thickness of the anodized film was measured by a generally used method.

<Comparative Example 2-4>
A porous layer is formed on the mirror surface of the aluminum substrate AL-5 in the same manner as in Example 2-1 of the present invention, and subsequently a sealing layer is formed to obtain a lithographic printing plate support of Comparative Example 2-4. It was.

4). Measurement of porosity of porous layer The porosity of the porous layer was determined from the film thickness of the porous layer shown in Table 4 and the mass of the porous layer after drying.
Specifically, the density was calculated by the following formula from the film thickness of the porous layer and the film mass per unit area.
Density (g / cm ³ ) = (film mass per unit area / film thickness)
Using the calculated density, the porosity was determined according to the following formula.
Porosity (%) = {1− (density of porous layer / D)} × 100
Here, D is the density (g / cm ³ ) according to the chemical handbook of the metal oxide used for forming the porous layer.
The film mass per unit area of the porous layer was measured by the so-called Mason method. The film thickness of the porous layer shown in Table 4 is a value measured by observing the film thickness with an ultrahigh resolution scanning electron microscope at the magnification shown below.
When the film thickness was 1 μm or less, the magnification was 10,000 times, when the film thickness was 1 to 5 μm, the magnification was 3000 times, and when the film thickness was 5 μm or more, the magnification was 100 to 3000 times.

5). Measurement of surface roughness Ra of lithographic printing plate support For each of the lithographic printing plate supports obtained in Inventive Examples 2-1 to 2-12 and Comparative Examples 2-1 to 2-4, Two-dimensional roughness measurement was performed with a thickness meter (SUFCOM 575, manufactured by Tokyo Seimitsu Co., Ltd.), the average roughness Ra specified in ISO 4287 was measured five times, and the average value was defined as the average roughness. The results are shown in Table 4.
The conditions for the two-dimensional roughness measurement are shown below.

<Measurement conditions>
Cut-off value 0.8mm, tilt correction FLAT-ML, measurement length 3mm, vertical magnification 10000 times, scanning speed 0.3mm / sec, stylus tip diameter 2μm

6). Preparation of lithographic printing plate precursor A photosensitive solution having the following composition was applied on each lithographic printing plate support obtained in Examples 2-1 to 2-12 and Comparative Examples 2-1 to 2-4 of the invention. After the liquid was applied so that the coating amount after drying was 1.0 g / m ² , it was dried at 140 ° C. for 50 seconds by setting Wind Control to 7 with TABIAI, PERFECT OVEN PH200, and lithographic printing plate I got the original version.

(Composition of photosensitive solution coating solution)
M, p-cresol novolak (m / p ratio = 6/4,
(Weight average molecular weight 3500, unreacted cresol containing 0.5% by mass) 0.427 g
-Siloxane structure-containing alkali-soluble resin (F-1) obtained by the following synthesis method 0.047 g
・ Specific copolymer 1 2.37 g described in JP-A-11-288093
・ 0.155 g of the above cyanine dye A
・ 2-Methoxy-4- (N-phenylamino) benzene 0.03 g
・ Diazonium hexafluorophosphate tetrahydrophthalic anhydride 0.19 g
・ The counter ion of ethyl violet was changed to 6-hydroxy-β-
0.05 g of naphthalene sulfonic acid
・ Fluorine surfactant (Megafac F-176PF,
Dainippon Ink & Chemicals, Inc.) 0.035g
・ Fluorine surfactant (Megafac MCF-312,
Dainippon Ink & Chemicals, Inc.) 0.05g
・ 0.008 g of p-toluenesulfonic acid
・ Bis-p-hydroxyphenylsulfone 0.063 g
・ Stearic acid n-dodecyl 0.06g
・ Γ-Butyrolactone 13g
・ Methyl ethyl ketone 24g
・ 11g of 1-methoxy-2-propanol

(Synthesis of siloxane structure-containing alkali-soluble resin (F-1))
120 g of cresol novolak (m / p ratio = 6/4, weight average molecular weight = 5200) was dissolved in 400 mL of methanol, 5.4 g of sodium methoxide was added, and the mixture was stirred for 30 minutes. Methanol was distilled off under reduced pressure, 400 mL of tetrahydrofuran was added, and the solvent was replaced. 17 g of epoxy-type terminal-reactive silicone MCR-E11 (manufactured by Chisso Corporation) was added, and the mixture was heated to reflux for 6 hours. The reaction solution was cooled to room temperature, poured into 8000 mL of water, and the separated product was collected by filtration, washed with water, and dried to obtain 132 g of a siloxane structure-containing alkali-soluble resin (F-1).

7). Evaluation of planographic printing plate precursor and planographic printing plate <Measurement of clear sensitivity>
Each lithographic printing plate precursor obtained as described above was output and exposed under a condition of resolution of 2400 dpi using a Creo Trendsetter 3244VFS equipped with a water-cooled 40 W infrared semiconductor laser. At this time, the plate surface energy was changed by changing the rotational speed of the outer drum.

After the image exposure, Fuji Photo was loaded with Fuji Photo Film Co., Ltd. developer DT-1 (diluted 1: 8) and Fuji Photo Film Co., Ltd. finisher FP2W (diluted 1: 1). Using a PS processor 900H manufactured by Film Co., Ltd., development was performed at a liquid temperature of 30 ° C. and a development time of 12 seconds (the electric conductivity of the developer at this time was 45 mS / cm).
Sensitivity was evaluated based on the minimum exposure amount at which development was satisfactorily possible without developing stains or coloring due to the residual film of the poorly developed image recording layer. Table 4 shows the exposure amount at that time.
The smaller the exposure amount, the better the sensitivity of the lithographic printing plate precursor.

<Stain resistance>
The lithographic printing plate precursor obtained above was imaged using a TrendSetter manufactured by Creo at a drum rotation speed of 150 rpm and a beam intensity of 10 W.
Printing using a lithographic printing plate obtained by developing as in the case of the above clear sensitivity evaluation, using a DIC-GEOS (s) red ink on a Mitsubishi Diamond F2 printer (manufactured by Mitsubishi Heavy Industries). After printing 50 sheets, the printing press is temporarily stopped, the blanket portion of the printing press is copied with Nitto Denko's PET tape, and the non-image portion is stained with ink visually according to the following criteria. evaluated. The results are shown in Table 4.
The evaluation criteria were evaluated in five stages of A, B, C, D, and E in order from the one in which the occurrence of contamination could not be confirmed at all.

<Print durability>
Using a planographic printing plate obtained by the same method as in the above evaluation of <stain resistance>, it was measured how many prints without residual color, residual film and stain were obtained under the same printing conditions. That is, when any one of the remaining color, the remaining film, and the stain is below the allowable level of the printed material, the printing is completed, and the number of printed sheets at that time is defined as the number of printed sheets. The results are shown in Table 4.
Evaluation criteria were evaluated in five stages of A, B, C, D, and E in descending order of the number of completed sheets.

<Shiny nature>
The lithographic printing plate obtained by the same method as the evaluation of <stain resistance> is attached to a Lithlon printing machine manufactured by Komori Corporation, and the light condition of the non-image area of the printing plate is increased while increasing the supply amount of dampening water. Was visually observed, and the shiny property (plate inspection property: ease of seeing water rising) was evaluated based on the supply amount of dampening water when it began to shine. The results are shown in Table 4.
The evaluation was made in the order of AA, A, B, C, D, and E in order from the amount of dampening water when it began to shine to the smallest amount.

As is apparent from Table 4, the surface roughness of a lithographic printing plate support provided with a porous layer in which metal oxide particles are bound by a compound containing metal atoms and phosphorus atoms is within the scope of the present invention. Then, the high heat insulating property (sensitivity), excellent printing durability and stain resistance of the porous layer were not impaired, and the printing durability and shiny property could be improved to a higher level.
In addition, even when an aluminum substrate is used as the substrate, the porous layer can be formed at a relatively low temperature (below the softening temperature of aluminum). I couldn't.
Furthermore, even if the lithographic printing plate support provided with the porous layer of the present invention is produced using various substrates, high thermal insulation (sensitivity), excellent printing durability and stain resistance are impaired. Furthermore, the printing durability and the shiny property could be improved to a higher level.
On the other hand, Comparative Examples 2-1 to 2-3 are particularly inferior in sensitivity, Comparative Example 2-4 is particularly inferior in shiny property, and the lithographic printing plate supports of Comparative Examples 2-1 to 2-4 are sensitive. , Printing durability, stain resistance or shiny.

<Invention Examples 3-1 to 3-15 (support for lithographic printing plate)>
On the substrate having the aluminum surface of the following (1) to (4), an intermediate layer coating solution having the composition shown in Table 5 below is a commercially available wire bar (wire thickness 0.25 mm), and the dry film thickness is Table 5. The lithographic printing plate support was prepared by coating and drying to form the dry film thickness shown in FIG. The porosity and thickness of the formed intermediate layer are also shown in Table 5 below.

(Substrate having an aluminum surface)
(1) 0.24 mm thick alkali degreased aluminum plate (shown as aluminum in Table 5),
(2) Aluminum-laminated paper (Oji Paper Co., Ltd. fine paper (180 μm thickness), Konishi Co., Ltd. multi-purpose bond (adhesion layer 50 μm), Sumitomo Light Metal Co., Ltd. aluminum foil (10 μm thickness), Produced using a TOLAMI laminator DX-700 (shown as Al / paper in Table 5)
(3) Polyethylene terephthalate (PET) film laminated with aluminum (PET manufactured by Toray Industries, Inc. (220 μm thickness), 3000DXF manufactured by Cemedine Co., Ltd. (adhesion layer 10 μm), aluminum foil manufactured by Sumitomo Light Metal Co., Ltd. (10 μm thickness)) , Produced using a TOLAMI laminator DX-700 (shown as Al / PET in Table 5)
(4) A steel plate (Kobe Steel Co., Ltd. steel plate (240 μm thickness) on which aluminum is vapor-deposited has a thickness of 0. 99.9% of aluminum on the outermost layer under conditions of a degree of vacuum of 10 ⁻⁶ Torr and a substrate temperature of 250 ° C. Prepared by vapor deposition of 1 μm (indicated as Al / steel plate in Table 5)

<Comparative Example 3-1>
A support for a planographic printing plate of Comparative Example 3-1 was prepared by providing an intermediate layer prepared by a coating liquid formulation not containing high void particles shown in Table 5 on the same substrate as Example 3-1 of the present invention. .

<Comparative Example 3-2>
After anodizing the same substrate as Example 3-1 and providing an anodic oxide film having a thickness of 1.0 μm, the micropores of the anodic oxide film were enlarged by immersion in an aqueous sodium hydroxide solution having a pH of 13; What improved the rate was used as the lithographic printing plate support of Comparative Example 3-2.

<Comparative Example 3-3>
A lithographic printing plate support of Comparative Example 3-3 was prepared by anodizing the same substrate as Example 3-1 and providing an anodic oxide film having a thickness of 1.0 μm.

<Comparative Example 3-4>
A polyethylene terephthalate (PET) film (PET (220 μm thickness) manufactured by Toray Industries, Inc.) was used as a lithographic printing plate support of Comparative Example 3-4.

In addition, the heat insulation and scratch resistance in Table 5 were evaluated as follows.
(Measurement method of heat insulation)
A. Titanium vapor deposition A metal titanium wire 0.5 mmφ × 20 mm (manufactured by Niraco Co., Ltd.) is heated for about 20 seconds at a vacuum degree of 4.5 × 10 ⁻⁶ Torr and a current of 40 A using a vacuum vapor deposition device (JEOL JEE-4X). After evaporation, it was attached to the sample.
B. Exposure Thereafter, exposure was carried out with a self-made YAG laser exposure apparatus (disk rotating type) at 0.724 W (plate surface energy 4.8 J / cm ² , sensitive material sensitivity 1000 mJ / cm ² equivalent), and the exposure line width was measured with an optical microscope. .
Laser specifications (device name: DPY321II manufactured by ADLAS)
Gaussian beam-shaped laser Beam diameter (1 / e ² ): 35 μm, scanning speed: 1.2 m / s
A commercially available PET base deposited with Ti had a line width of 50 μm. Based on this, a five-step relative evaluation was performed as follows. The results are shown in Table 5.
Thermal insulation evaluation A: Line width 55-45 μm
B: Line width 44-35 μm
C: Line width 34-25 μm
D: Line width 24-15 μm
E: Line width less than 15 μm

(Scratch resistance measurement method)
A scratch test was conducted under the following conditions using a continuous load type scratch strength tester TYPE18 manufactured by Shinto Kagaku Co., Ltd.
Needle: Sapphire 0.4mmφ
Scratching speed: 10 cm / s
Weight: 30g
The scratch portion was observed with an SEM, and four-step evaluation was performed according to the following scratch state. The results are shown in Table 5.
Scratch resistance evaluation A: There is no scratch at all.
B: Scratch marks are slightly seen on the surface.
C: A clear scratch mark is seen.
E: Scratches have reached the substrate surface.

<Invention Examples 3-16 to 3-30 and Comparative Examples 3-5 to 3-8 (heat-sensitive lithographic printing plate)>
(1) Formation of hydrophilic layer The following is shown on the intermediate layer of the lithographic printing plate support prepared in Invention Examples 3-1 to 3-15 and the support of Comparative Examples 3-1 to 3-4. The hydrophilic layer coating solution having the composition was applied and dried with a commercially available wire bar (wire thickness: 0.25 mm) so that the dry film thickness was 0.10 μm to form a hydrophilic layer.

(Hydrophilic layer coating solution)
・ Metal oxide fine particles (Nanotech Alumina manufactured by CI Kasei Co., Ltd.)
Product name: Ultrafine particles, average particle size 33 nm) 18.5 g
・ No.3 sodium silicate 19.8g
・ Acrylic emulsion, Almatex E269 (Mitsui Chemicals) 0.8g
・ Water 1400g

(2) Formation of thermosensitive layer (2-1) Preparation of microcapsules 40 g of xylene diisocyanate, 10 g of trimethylolpropane diacrylate, 10 g of a copolymer of allyl methacrylate and butyl methacrylate (molar ratio 7/3) and a surfactant (pionein) 0.1 g of A41C (manufactured by Takemoto Yushi Co., Ltd.) was dissolved in 60 g of ethyl acetate to obtain an oil phase component. On the other hand, 120 g of a 4% aqueous solution of polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.) was prepared and used as an aqueous phase component. The oil phase component and the aqueous phase component were charged into a homogenizer and emulsified using 10,000 rpm. Thereafter, 40 g of water was added, stirred at room temperature for 30 minutes, and further stirred at 40 ° C. for 3 hours to obtain a microcapsule solution. The obtained microcapsule liquid had a solid content concentration of 20% by mass, and the average particle size of the microcapsules was 0.2 μm.

(2-2. Application of heat-sensitive layer)
On the hydrophilic layer of the support obtained above, a heat-sensitive layer coating solution having the following composition was applied and dried in an oven at 60 ° C. for 150 seconds to obtain a heat-sensitive lithographic printing plate. The dry coating amount of the heat sensitive layer was 0.7 g / m ² .

<Thermosensitive layer coating solution composition>
・ Microcapsule liquid synthesized above (in terms of polymer solids) 5g
・ Trimethylolpropane triacrylate 3g
・ Photothermal conversion agent (cyanine dye B below) 0.3g
・ Water 60g
・ 1-methoxy-2-propanol 40g

The following characteristic evaluation was performed on the heat-sensitive lithographic printing plate thus obtained.
(Evaluation of sensitivity)
The above heat-sensitive lithographic printing plate was output and exposed under the condition of a resolution of 2400 dpi using a Creo Trendsetter 3244VFS equipped with a water-cooled 40 W infrared semiconductor laser. At this time, the plate surface energy was changed by changing the rotational speed of the outer drum. The exposed plate was mounted on a printing machine as it was and developed with on-press development by supplying dampening water and ink. Thus, the sensitivity was evaluated by obtaining the minimum exposure amount that can form an image. The results are shown in Table 6 below.

(Stain resistance evaluation)
The printing machine was temporarily stopped, the ink in the blanket part of the printing machine was copied with a PET tape manufactured by Nitto Denko Corporation, and the degree of smearing with the ink in the non-image part was visually evaluated according to the following criteria. The results are shown in Table 6 below.

Dirtiness A: The occurrence of dirt is not observed at all visually.
B: The occurrence of dirt is hardly observed visually.
C: Occurrence of dirt is visually observed.
D: Contamination is remarkable.
E: Dirt is generated over the entire non-image area.

(Print life)
Under the same conditions, the number of prints without residual color, residual film, and stain was measured. In other words, when any of the remaining color, remaining film, and dirt falls below the acceptable level of printed matter, the printing is finished, and the printing durability is as follows according to the number of printed sheets (number of printed sheets) at that time. evaluated. The results are shown in Table 6 below.

Printing durability A: 10,000 sheets or more
B: 9999-3000 sheets
C: 3000 sheets or less

<Invention Examples 3-31 to 3-45 and Comparative Examples 3-9 to 3-12>
Similar to Inventive Examples 3-16 to 3-30 and Comparative Examples 3-5 to 3-8 on the supports obtained in Inventive Examples 3-1 to 3-15 and Comparative Examples 3-1 to 3-4 Was provided with a hydrophilic layer. On the hydrophilic layer, apply the following coating solution 1 for positive thermosensitive layer so that the dry coating amount is 1.0 g / m ² , and set WIND CONTROL to 7 on PERFECT OVEN PH200 manufactured by TABAI. And dried at 140 ° C. for 50 seconds to obtain a heat-sensitive lithographic printing plate.

(Coating liquid 1)
m, p-cresol novolak (m / p ratio = 6/4, 0.427 g
(Weight average molecular weight 3500, containing 0.5% by mass of unreacted cresol)
Siloxane structure-containing alkali-soluble resin (F-1) 0.047 g
2.37 g of specific copolymer 1 described in JP-A-11-288093
Photothermal conversion agent (cyanine dye C below) 0.155g
2-Methoxy-4- (N-phenylamino) benzene 0.03 g
Diazonium hexafluorophosphate tetrahydrophthalic anhydride 0.19g
0.05 g of 6-hydroxy-β- counterion of ethyl violet
Naphthalenesulfonate Fluorosurfactant (Megafac F-176PF, 0.035g
Dainippon Ink & Chemicals, Inc.)
Fluorosurfactant (Megafac MCF-312, 0.05g
Dainippon Ink & Chemicals, Inc.)
p-Toluenesulfonic acid 0.008g
Bis-p-hydroxyphenylsulfone 0.063 g
N-dodecyl stearate 0.06g
γ-Butyllactone 13g
24g of methyl ethyl ketone
11 g of 1-methoxy-2-propanol

(Synthesis of siloxane structure-containing alkali-soluble resin (F-1))
120 g of cresol novolak (m / p = 60/40, Mw = 5.2 × 10 ³ ) was dissolved in 400 ml of methanol, 5.4 g of sodium methoxide was added, and the mixture was stirred for 30 minutes. Methanol was distilled off under reduced pressure, 400 ml of tetrahydrofuran was added, and the solvent was replaced. 17 g of epoxy-type terminal-reactive silicone MCR-E11 (manufactured by Chisso Corporation) was added, and the mixture was heated to reflux for 6 hours. The reaction solution was cooled to room temperature, poured into 8000 ml of water, and the separated product was collected by filtration, washed with water, and dried to obtain 132 g of a siloxane structure-containing alkali-soluble resin (F-1).

The heat-sensitive positive lithographic printing plate produced as described above was evaluated for sensitivity, stain resistance, and printing durability in the same manner as in Inventive Example 3-16. The heat-sensitive positive lithographic printing plate was diluted with a developer DT-1 (1: 8, manufactured by Fuji Photo Film Co., Ltd.) after image exposure instead of on-press development in the case of Invention Example 3-16. And a Fuji Photo Film Co., Ltd. finisher FP2W (diluted 1: 1) and a Fuji Photo Film Co., Ltd. PS processor 900H, developed at a liquid temperature of 30 ° C. and a development time of 12 seconds. (The conductivity of the developer at this time was 45 mS / cm).
The evaluation results are shown in Table 7 below.

It is a side view which shows the concept of the process of the brush graining used for the mechanical roughening process in preparation of the support body for lithographic printing plates of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2, 4 Rotating brush 3 Polishing slurry liquid 5, 6, 7, 8 Support roller

Claims (7)

  A lithographic printing plate support comprising a porous layer formed by binding metal oxide particles with a compound containing a metal atom and a phosphorus atom on a substrate.   The lithographic printing plate support according to claim 1, wherein the metal oxide is an oxide or composite oxide of at least one metal selected from the group consisting of silicon, magnesium, zirconium and titanium.   The lithographic printing plate support according to claim 1 or 2, wherein a sealing layer is provided on the porous layer.   The film thickness of the porous layer is 0.5 to 20 µm, the film thickness of the sealing layer is 0.01 to 0.5 µm, and the surface roughness Ra is 0.3 to 2.0 µm. 4. The lithographic printing plate support according to 3.   A support for a lithographic printing plate comprising an intermediate layer formed from a composition containing alumina particles, high void particles, phosphoric acid, and an aluminum compound as main components on a substrate.   6. The lithographic printing plate support according to claim 1, wherein the substrate is an aluminum plate, aluminum laminated paper, aluminum laminated resin, or aluminum coated metal.   The substrate is roughened, and a porous layer formed by binding metal oxide particles with a compound containing metal atoms and phosphorus atoms is provided on the roughened substrate, and the porous layer A method for producing a support for a lithographic printing plate, comprising providing a sealing layer thereon.

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