JP3989421B2 - Lithographic printing plate support and lithographic printing plate precursor - Google Patents

Description

The present invention relates to a lithographic printing plate support and a lithographic printing plate precursor.
Specifically, the present invention is excellent in stain resistance, and in particular, when the amount of dampening water is reduced, the non-image area is less likely to be stained (background stain), and the image recording layer and the support in the image area A lithographic printing plate support and a lithographic plate capable of forming a lithographic printing plate having strong adhesion, excellent printing durability, and excellent printing properties (cleaner printing durability) that do not deteriorate when wiping with a cleaner. It relates to the printing plate precursor.
In addition to the above-described characteristics, the present invention is unlikely to generate a spot-like residual film (pot-like residual film). In particular, when a laser direct-drawing type image recording layer is provided, The present invention relates to a lithographic printing plate support and a lithographic printing plate precursor which can be used as a lithographic printing plate having an excellent effect of preventing the occurrence of residual film.

  The lithographic printing method is a printing method that utilizes the fact that water and oil are not essentially mixed. The printing plate surface of the lithographic printing plate used for this is a region that accepts water and repels oil-based ink (hereinafter referred to as “removal”). This region is referred to as a “non-image portion”) and a region that repels water and receives oil-based ink (hereinafter, this region is referred to as “image portion”).

An aluminum support for a lithographic printing plate used for a lithographic printing plate (hereinafter simply referred to as a “support for a lithographic printing plate”) is used so that its surface bears a non-image portion, and therefore has hydrophilicity and water retention. Are required to have various performances which are contradictory to each other, for example, excellent adhesion, and excellent adhesion to an image recording layer provided thereon.
If the hydrophilicity of the support is too low, ink will adhere to the non-image area during printing, and the blanket cylinder will be soiled, and so-called background soiling will occur. On the other hand, if the water holding capacity of the support is too low, the shadow portion is clogged unless dampening water is increased during printing. Therefore, the so-called water width is narrowed.

  On the other hand, in the non-image area, in order to maintain the resistance to dirt, it is preferable that the surface unevenness is gentle so that unnecessary ink does not adhere. However, if the surface unevenness is gentle, the image recording layer The adhesiveness between the substrate and the support is lowered, and the printing durability is lowered. That is, the stain resistance and the printing durability are in a trade-off relationship.

In order to obtain a lithographic printing plate support having good performance, it is common to make the surface of an aluminum plate grained (roughening treatment) to give irregularities. As for the unevenness, various shapes have been proposed as shown below.
For example, a triple structure having a large wave, a medium wave and a small wave defining the opening diameters of the medium wave and the small wave (see Patent Document 1), and a structure defining the diameter of the small wave in a large and small double structure (Patent Documents 2 and 3). ), A technique for providing finer protrusions in addition to large and small double recesses (pits) (see Patent Document 4), a double structure that defines an opening diameter (see Patent Document 5), and the surface. Ratio of pit diameters superimposed in a double structure defining factor a30 indicating smoothness (see Patent Document 6) and a plurality of electrochemical roughening treatments (hereinafter also referred to as “electrolytic roughening treatment”) Has been proposed (see Patent Document 7).

  This graining includes mechanical graining methods such as ball graining, brush graining, wire graining, and blast graining, and an electrolytic grained surface for electrolytic etching of an aluminum plate in an electrolyte containing hydrochloric acid and / or nitric acid. And a composite roughening method (see Patent Document 8) in which a mechanical roughening method and an electrolytic roughening method are combined.

JP-A-8-300844 Japanese Patent Laid-Open No. 11-99758 Japanese Patent Laid-Open No. 11-208138 JP 11-167207 A Japanese Patent No. 2023476 JP-A-8-300843 Japanese Patent Laid-Open No. 10-35133 US Pat. No. 4,476,006

In the middle of printing, the plate surface may be cleaned using a chemical called a cleaner.This cleaner removes unnecessary ink adhering to the surface of the non-image area, and simultaneously with the image recording layer. It may permeate between the support and the adhesiveness of the base material, thereby reducing the printing durability. Therefore, the property that the printing durability does not deteriorate even when wiped with a cleaner (cleaner printing durability) is an important characteristic for a lithographic printing plate.
However, the lithographic printing plate support has excellent hydrophilicity and water retention, excellent stain resistance, excellent adhesion to the image recording layer, excellent printing durability, and excellent cleaner printing durability. Was not realized.

  Accordingly, the present invention provides a lithographic printing plate precursor having excellent printing durability and stain resistance and excellent cleaner printing durability when used as a lithographic printing plate, and a lithographic printing plate support used therefor. For the purpose.

  As a result of intensive studies on the surface shape of a lithographic printing plate support to solve the above problems, the present inventor has various factors representing the surface shape required using an atomic force microscope as a specific range. Further, the inventors have found that the printing durability and stain resistance are excellent, and that the cleaner printing durability is also excellent, and the present invention has been completed.

That is, using an atomic force microscope, the surface area ratio and steepness obtained from three-dimensional data obtained by measuring 512 × 512 points each of 50 μm × 50 μm and 5 μm × 5 μm on the surface are the following conditions (i) to ( Provided is a lithographic printing plate support satisfying iii).
(I) Surface area ratio ΔS ⁵⁰ is 60 to 90%
(Ii) Steepness a45 ^{50 (0.2-2)} is 10 to 50%
(Iii) Surface area ratio ΔS ^{5 (0.02-0.2)} is 20 to 80%
Here, the surface area ratio ΔS ⁵⁰ is an actual area S _x ⁵⁰ determined by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points of 50 μm × 50 μm of the surface using an atomic force microscope, From the geometric measurement area S ₀ ⁵⁰ , the surface area ratio determined by the following formula (1):
ΔS ⁵⁰ = (S _x ⁵⁰ −S ₀ ⁵⁰ ) / S ₀ ⁵⁰ × 100 (%) (1)
The steepness a45 ^{50 (0.2-2)} is obtained by extracting components having a wavelength of 0.2 μm or more and 2 μm or less from 3D data obtained by measuring 512 × 512 points of 50 μm × 50 μm on the surface using an atomic force microscope. Is the steepness that is the area ratio of the portion with the slope of 45 ° or more in the data obtained by
The surface area ratio ΔS ^{5 (0.02-0.2)} is determined from three-dimensional data obtained by measuring 512 × 512 points on a surface of 5 μm × 5 μm using an atomic force microscope, and a component having a wavelength of 0.02 μm to 0.2 μm. It is a surface area ratio obtained by the following formula (2) from the actual area S _x ^{5 (0.02-0.2)} obtained by the approximate three-point method from the data obtained by extraction and the geometric measurement area S ₀ ⁵ .
ΔS ^{5 (0.02-0.2)} = (S _x ^{5 (0.02-0.2)} −S ₀ ⁵ ) / S ₀ ⁵ × 100 (%) (2)

  In general, it is effective to increase the surface roughness in order to improve water retention. However, if the surface roughness is increased, locally deep recesses are likely to be generated. A deep recess causes exposure failure and development failure, and a pot-like residual film is likely to occur. That is, improvement in water retention and improvement in pot-like residual film are contradictory.

  The present inventor has found that when the number of local deep portions having a specific depth or more existing on the surface is equal to or less than a specific numerical value, the generation of a pot-like residual film is extremely suppressed.

  That is, the number of local deep portions having a depth of 4 μm or more present on the surface is preferably 6 or less per 400 μm × 400 μm.

  The present invention also provides a lithographic printing plate precursor in which an image recording layer is provided on the lithographic printing plate support.

By using the lithographic printing plate support of the present invention having a surface shape feature, it is possible to maintain a high level of stain resistance and printing durability that could not be removed from the conventional trade-off relationship, and High cleaner printing durability can be satisfied.
Further, when the number of local deep portions existing on the surface of the lithographic printing plate support of the present invention is set within a specific range, generation of a pot-like residual film can be sufficiently suppressed in addition to the above characteristics.

The lithographic printing plate support of the present invention has a surface area ratio ΔS ⁵⁰ and steepness a45 ^{50 (} obtained from three-dimensional data obtained by measuring 512 × 512 points of 50 μm × 50 μm of the surface using an atomic force microscope. ^0.2-2) and a surface area specific surface area ratio ΔS ^{5 (0.02-0.2)} obtained from three-dimensional data obtained by measuring 512 × 512 points on a surface of 5 μm × 5 μm using an atomic force microscope is as follows: Conditions (i) to (iii) are satisfied.
(I) Surface area ratio ΔS ⁵⁰ is 60 to 90%
(Ii) Steepness a45 ^{50 (0.2-2)} is 10 to 50%
(Iii) Surface area ratio ΔS ^{5 (0.02-0.2)} is 20 to 80%

The above (i) surface area ratio ΔS ⁵⁰ is obtained by measuring 512 × 512 points of 50 μm × 50 μm of the surface (hereinafter sometimes referred to as “50 μm □”) using an atomic force microscope. It is a surface area ratio obtained from the following formula (1) from the actual area S _x ⁵⁰ obtained from the data by the approximate three-point method and the geometric measurement area S ₀ ⁵⁰ .
ΔS ⁵⁰ = (S _x ⁵⁰ −S ₀ ⁵⁰ ) / S ₀ ⁵⁰ × 100 (%) (1)

The above (ii) steepness a45 ^{50 (0.2-2)} is a component having a wavelength of 0.2 μm or more and 2 μm or less from three-dimensional data obtained by measuring 512 × 512 points of the surface 50 μm □ using an atomic force microscope. Is the steepness, which is the area ratio of the portion with the slope of 45 ° or more in the data obtained by extracting.

The above (iii) surface area ratio ΔS ^{5 (0.02-0.2)} is obtained by measuring 512 × 512 points of the surface 5 μm × 5 μm (hereinafter sometimes referred to as “5 μm □”) using an atomic force microscope. The actual area S _x ^{5 (0.02-0.2)} obtained by the approximate three-point method from the data obtained by extracting components with wavelengths of 0.02 μm or more and 0.2 μm or less from the three-dimensional data obtained, and the geometric measurement area From S ₀ ⁵ , the surface area ratio is obtained by the following formula (2).
ΔS ^{5 (0.02-0.2)} = (S _x ^{5 (0.02-0.2)} −S ₀ ⁵ ) / S ₀ ⁵ × 100 (%) (2)

ΔS ⁵⁰ is a factor indicating the degree of increase in the actual area S _x ⁵⁰ by the roughening process with respect to the geometric measurement area S ₀ ⁵⁰ . When ΔS ⁵⁰ increases, the contact area with the image recording layer increases, and as a result, printing durability can be improved. Here, the surface area ratio ΔS ⁵⁰ obtained without extracting the wavelength component from the three-dimensional data obtained by measuring 512 × 512 points on the surface of 50 μm □, that is, the surface area ratio including a long wavelength component is increased. As a result, the contact area between the image recording layer and the support is increased, and the printing durability is improved. In order to increase ΔS ⁵⁰ , for example, the total amount of electricity involved in the anodic reaction in an electrolytic surface roughening treatment using an electrolytic solution mainly composed of hydrochloric acid is an electrochemical rough surface with an electric amount of 300 C / dm ² or more. And a method of using three or more brush rolls in a mechanical surface-roughening treatment using a brush roll and an abrasive can be used.

In the present invention, ΔS ⁵⁰ is 60% or more, preferably 61% or more, more preferably 65% or more, and further preferably 70% or more. ΔS ⁵⁰ is preferably 90% or less, because if it is too large, dirt resistance may decrease.

a45 ^{50 (0.2-2)} is a factor representing the sharpness of the fine shape of the support surface. Specifically, it represents the ratio of the area having an inclination of 45 ° or more to the actual area S _x ^{50 in} the unevenness of the support surface. As a result of various studies, the present inventor has found that the steepness portion in the component having a wavelength of 0.2 μm or more and 2 μm or less tends to become a base point where ink is caught at the time of printing in the non-image portion, thereby causing background staining. . That is, it has been found that, with respect to components having a wavelength of 0.2 μm or more and 2 μm or less, by setting a45 ^{50 (0.2-2)} within a specific range, the stain resistance can be improved.

In the present invention, a45 ^{50 (0.2-2)} is 50% or less, preferably 45% or less, and more preferably 30% or less. If a45 ^{50 (0.2-2)} is too small, the printing durability may be lowered. Therefore, it is preferably 10% or more.

ΔS ^{5 (0.02-0.2)} is a factor indicating the degree of increase in the actual area S _x ^{5 (0.02-0.2)} due to the roughening treatment with respect to the geometric measurement area S ₀ ⁵ . When ΔS ^{5 (0.02-0.2)} increases, the contact area with the image recording layer increases, and as a result, the printing durability can be improved. Here, the surface area ratio ΔS ^{5 (0.02-0.2)} in the data obtained by extracting the component having the wavelength of 0.02 μm or more and 0.2 μm or less from the three-dimensional data obtained by measuring 512 × 512 points on the surface of 5 μm □, That is, by increasing the surface area ratio contributed by the short wavelength component, the contact area between the image recording layer and the support is increased, the printing durability is improved, and the space between the image recording layer and the support is increased. It is possible to greatly suppress the penetration of the cleaner and improve the cleaner printing durability. In order to increase ΔS ^{5 (0.02-0.2)} , for example, a method of performing AC electrolytic surface roughening treatment in a hydrochloric acid electrolyte so that the total amount of electricity involved in the anode reaction is 10 to 100 C / dm ^2. For example, a method of dissolving a minute amount (for example, 0.05 to 0.5 g / m ² ) of aluminum with an alkaline solution after performing an AC electrolytic surface roughening treatment in a nitric acid electrolytic solution can be used.

In the present invention, ΔS ^{5 (0.02-0.2)} is 20% or more, preferably 40% or more, and more preferably 50% or more. ΔS ^{5 (0.02-0.2)} is preferably 80% or less because it may cause development failure if it is too large.

In the present invention, the above-described object of the present invention can be achieved by ^{setting the} above ΔS ⁵⁰ , ΔS ^{5 (0.02-0.2)} and a45 ^{50 (0.2-2)} to the above-described ranges. That is, even if the ΔS ^{50 is set} to a relatively large range of 60 to 90%, by making ΔS ^{5 (0.02-0.2)} and a45 ^{50 (0.2-2)} within the above ranges, stain resistance and printing durability can be improved. The balance can be maintained at a high level, and the cleaner durability can be improved.

Furthermore, in the present invention, the number of local deep portions having a depth of 4 μm or more present on the surface is preferably 6 or less per 400 μm × 400 μm (hereinafter sometimes referred to as “400 μm □”). More preferably, it is 4 or less. As a result, even if ΔS ⁵⁰ is made relatively large and the conditions of exposure and development are strict, no pot-like residual film is generated.

As a result of earnest research on the cause of the formation of a recess having a depth of 4 μm or more by the roughening treatment described later, the present inventor estimated the cause as follows.
First, when a roughening process including a mechanical roughening process is performed, the ridges of the abrasive particles used in the mechanical roughening process penetrate deeply into the surface of the aluminum plate to form a recess. To be done.
Secondly, when a roughening treatment including an electrolytic roughening treatment is performed, the current is concentrated at a specific location during the electrolytic roughening treatment.

The present inventor has estimated the cause in this way, and as a result of earnest research, as a result of the following means, the number of recesses having a depth of 4 μm or more generated by the roughening treatment is 6 or less per 400 μm × 400 μm on the surface. Found that it can be.
That is, the following means (i) to (v) have been found for the piercing of abrasive particles used in the mechanical roughening treatment, which is the first cause.
(I) An abrasive having a small particle size is used.
For example, sedimentation separation is performed to remove large particles, and only small particles are used, or the particles of the abrasive are brought into contact with each other by re-grinding to reduce the particle size of the abrasive. can do.
(Ii) An abrasive with particles having few sharp edges is used.
Pumiston (hereinafter also referred to as “pumice”), which is usually used for mechanical surface roughening, is obtained by crushing volcanic ash, and its particles are shaped like a piece of glass like a broken glass with sharp edges. Yes. On the other hand, silica sand has a shape close to a dodecahedron or a 24-hedron, and has little sharpness.

(Iii) The bristle used for the mechanical surface roughening treatment is softened.
For example, the brush hair can be softened by using a brush with a thin bristle diameter or using a soft brush.
(Iv) The rotational speed of the brush used for the mechanical surface roughening process is lowered.
By appropriately giving “escape” time to the abrasive particles contained in the slurry liquid, sticking is suppressed.
(V) Lowering the pressure (load) of the brush used for the mechanical surface roughening treatment.

Further, the following means (vi) to (viii) have been found with respect to the fact that the current is concentrated at a specific location during the electrolytic surface-roughening treatment as the second cause.
(Vi) When an electrolytic solution mainly composed of nitric acid is used in the electrolytic surface-roughening treatment, the amount of Cu in the alloy component of the aluminum plate is lowered so that electrolysis is likely to occur uniformly.
In the electrolytic surface-roughening treatment, a smut in which the aluminum dissolution reaction (pitting reaction) and the components generated by the dissolution are reattached to the dissolution reaction part by passing an alternating current in an acidic electrolytic solution. Adhesion reactions occur alternately according to an alternating cycle. Here, when the nitric acid electrolyte is used, it is very easily affected by the type and amount of alloy components contained in the aluminum plate, and particularly, the influence of Cu is large. This is presumably because the presence of Cu increases the surface resistance during the electrolytic surface roughening treatment. Therefore, by setting the amount of Cu in the alloy component to 0.040% by mass or less, the surface resistance during the electrolytic surface roughening treatment is reduced, so that current concentration is suppressed and uniform without forming coarse pits. Pits can be formed on the entire surface.

(Vii) When an electrolytic solution mainly composed of nitric acid is used in the electrolytic surface roughening treatment, pre-electrolysis can be performed before the electrolytic surface roughening treatment.
In pre-electrolysis, the starting point of pit formation can be formed uniformly. Thereby, uniform pits can be formed on the entire surface without forming coarse pits in the subsequent electrolytic surface roughening treatment.
(Viii) When an electrolytic solution mainly composed of hydrochloric acid is used in the electrolytic surface roughening treatment, acetic acid or sulfuric acid is contained in the electrolytic solution.
Even in hydrochloric acid electrolysis, coarse pits may be formed due to current concentration, but when hydrochloric acid electrolyte containing acetic acid or sulfuric acid is used, uniform pits can be formed on the entire surface without forming coarse pits. Can do.

The method for determining ΔS ⁵⁰ , a45 ^{50 (0.2-2)} and ΔS ^{5 (0.02-0.2)} in the lithographic printing plate support of the present invention is as follows.

(1) Measurement of surface shape by atomic force microscope In the present invention, in order to obtain ΔS ⁵⁰ , a45 ^{50 (0.2-2)} and ΔS ^{5 (0.02-0.2)} , an atomic force microscope (AFM) is obtained. ) To measure the surface shape and obtain three-dimensional data.
The measurement can be performed, for example, under the following conditions. That is, the lithographic printing plate support is cut to a size of 1 cm square, set on a horizontal sample stage on a piezo scanner, the cantilever is approached to the sample surface, and when the region where the atomic force works is reached, XY Scanning in the direction, the unevenness of the sample is captured by the displacement of the piezo in the Z direction. A piezo scanner that can scan 150 μm in the XY direction and 10 μm in the Z direction is used. The cantilever has a resonance frequency of 120 to 400 kHz and a spring constant of 12 to 90 N / m (for example, SI-DF20 and SI-DF40, both manufactured by Seiko Instruments; NCH, manufactured by NANOSENSORS; or AC-160TS, manufactured by Olympus) ) And measure in DFM mode (Dynamic Force Mode). Further, the reference plane is obtained by correcting the slight inclination of the sample by approximating the obtained three-dimensional data by least squares.
At the time of measurement, for ΔS ⁵⁰ and a45 ^{50 (0.2-2)} , a surface of 50 μm □ is measured at 512 × 512 points. The resolution in the XY direction is 0.1 μm, the resolution in the Z direction is 0.15 nm, and the scan speed is 50 μm / sec.
For ΔS ^{5 (0.02-0.2)} , 512 μm ^square of the surface is measured at 512 × 512 points. The resolution in the XY direction is 0.01 μm, the resolution in the Z direction is 0.15 nm, and the scan speed is 5 μm / sec.

(2) Correction of three-dimensional data For the calculation of ΔS ⁵⁰ , three-dimensional data based on the measurement of 50 μm □ of the surface obtained in (1) above is used as it is.
For the calculation of a45 ^{50 (0.2-2)} , a component obtained by extracting a component having a wavelength of 0.2 μm or more and 2 μm or less from three-dimensional data based on the surface measurement of 50 μm □ obtained in (1) above is used. Extraction of components having a wavelength of 0.2 μm or more and 2 μm or less is performed by performing a fast Fourier transform on the three-dimensional data obtained in (1) above to obtain a frequency distribution, and then a component having a wavelength less than 0.2 μm and a wavelength exceeding 2 μm. After removing the components, the inverse Fourier transform is performed.
In addition, ΔS ^{5 (0.02-0.2)} is calculated by extracting a component having a wavelength of 0.02 μm or more and 0.2 μm or less from three-dimensional data based on the measurement of 5 μm □ of the surface obtained in (1) above. Use. Extraction of components having a wavelength of 0.02 μm or more and 0.2 μm or less is performed by performing a fast Fourier transform on the three-dimensional data obtained in (1) above to obtain a frequency distribution, and then a component having a wavelength of less than 0.02 μm and a wavelength of 0 After removing components exceeding 2 μm, inverse Fourier transform is performed.

(3) Calculation of each factor (i) ΔS ⁵⁰
Using the three-dimensional data (f (x, y)) obtained in (1) above, three adjacent points are extracted, the sum of the areas of the small triangles formed by the three points is obtained, and the actual area S _x ⁵⁰ . The surface area ratio ΔS ⁵⁰ is obtained by the above formula (1) from the obtained real area S _x ⁵⁰ and the geometric measurement area S ₀ ⁵⁰ .

(Ii) a45 ^{50 (0.2-2)}
Using three-dimensional data (f (x, y)) obtained by correcting in (2) above, each reference point is formed by three points in the predetermined direction (for example, right and bottom). The angle formed by the small triangle to be formed and the reference plane is calculated for each reference point. The number of reference points where the inclination of the micro triangle is 45 degrees or more is obtained by subtracting the number of all reference points (the number of all data 512 × 512 points from the number of points that do not have two adjacent points in a predetermined direction). In other words, the area ratio a45 ^{50 (0.2-2)} of the portion with the inclination of 45 degrees or more is calculated by dividing by 511 × 511 points.

(Iii) ΔS ^{5 (0.02-0.2)}
Using the three-dimensional data (f (x, y)) obtained by the correction in (2) above, three adjacent points are extracted, and the total area of the micro triangles formed by the three points is obtained. The area is S _x ^{5 (0.02-0.2)} . The surface area ratio ΔS ^{5 (0.02-0.2)} is obtained by the above formula (2) from the obtained actual area S _x ^{5 (0.02-0.2)} and the geometric measurement area S ₀ ⁵ .

In the lithographic printing plate support of the present invention, the method for measuring the number of local deep portions having a depth of 4 μm or more present on the surface is as follows.
Using a laser microscope, 400 μm □ of the surface is scanned in a non-contact manner with a resolution of 0.01 μm to obtain three-dimensional data, and the number of recesses having a depth of 4 μm or more is counted in this three-dimensional data.

<Surface treatment>
The lithographic printing plate support of the present invention is one in which the above-mentioned surface grain shape is formed on the surface of the aluminum plate by subjecting the aluminum plate described later to surface treatment. The lithographic printing plate support of the present invention is obtained by subjecting an aluminum plate to a surface roughening treatment, but the production process of this support is not particularly limited, and includes various steps other than the surface roughening treatment. May be.
In the following, as a representative method for forming the above-described surface grain shape,
A method of sequentially performing mechanical surface roughening treatment, alkali etching treatment, desmutting treatment with an acid and electrochemical surface roughening treatment using an electrolytic solution on an aluminum plate,
A method of performing mechanical surface roughening treatment, alkaline etching treatment, desmutting treatment with acid and electrochemical surface roughening treatment using different electrolytes a plurality of times on an aluminum plate,
A method of sequentially performing an alkali etching treatment, an acid desmutting treatment on an aluminum plate, and an electrochemical surface roughening treatment using an electrolytic solution,
Examples of the method include performing an alkali etching treatment, an acid desmutting treatment on an aluminum plate, and an electrochemical surface roughening treatment using different electrolytic solutions a plurality of times, but the present invention is not limited thereto. In these methods, after the electrochemical roughening treatment, an alkali etching treatment and an acid desmutting treatment may be further performed.

ΔS ⁵⁰ , a45 ^{50 (0.2-2)} , ΔS ^{5 (0.02-0.2 )} , which are factors representing the surface shape, and the number of local deep ^portions having a depth of 4 μm or more present on the surface should satisfy specific conditions. As the roughening treatment suitably used for forming the surface, mechanical roughening treatment, hydrochloric acid electrolysis (electrochemical roughening mainly composed of hydrochloric acid), although depending on the conditions of other treatments (alkali etching treatment, etc.). Surface treatment), nitric acid electrolysis (electrochemical surface roughening treatment mainly composed of nitric acid), and a method of sequentially performing a combination of these. Another example is a method in which only an electrochemical surface roughening treatment in which the total amount of electricity involved in the anodic reaction is increased is performed using an electrochemical surface roughening treatment mainly composed of hydrochloric acid.

The lithographic printing plate support of the present invention obtained by these methods and having the above-mentioned factors representing the surface shape satisfy specific conditions, respectively, is excellent in printing durability and stain resistance when used as a lithographic printing plate. In addition, it has excellent cleaner printing durability. Further, the support for a lithographic printing plate of the present invention preferably does not easily generate a pot-like residual film.
Hereinafter, each step of the surface treatment will be described in detail.

<Mechanical roughening>
The mechanical roughening treatment is effective as a roughening treatment means because it can form an uneven surface with an average wavelength of 5 to 100 μm at a lower cost than the electrochemical roughening treatment. is there.
Examples of the mechanical surface-roughening treatment method include, for example, a wire brush grain method in which the aluminum surface is scratched with a metal wire, a ball grain method in which the aluminum 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 aluminum plate can also be used. That is, JP-A 55-74898, JP-A 60-36195, JP-A 60-36196, JP-A 60-20396, JP-A 61-162351, JP-B-4-30358. In addition to the method described in the publication, JP-A-6-55871 characterized in that the transfer is carried out several times, and Japanese Patent Application No. 4-204235 characterized in that the surface is elastic (Japanese Unexamined Patent Publication No. 4-204235). 6-024168) is also applicable.
As will be described later, in the brush grain method, it is particularly preferable to use a plurality of nylon brushes, and various abrasive materials described later can be used as the abrasive, but it is preferable to use pumiston, silica sand, aluminum hydroxide or the like. preferable. In the transfer method, it is preferable to appropriately adjust the rotational speed, load, and the like of the drive motor that rotates the brush.

In addition, by using electric discharge machining, shot blasting, laser, plasma etching, etc., a method of performing repetitive transfer using a transfer roll etched with fine irregularities, or an uneven surface coated with fine particles on an aluminum plate It is also possible to use a method in which an uneven pattern corresponding to the average diameter of the fine particles is repeatedly transferred to the aluminum plate a plurality of times by contacting the surface and applying a pressure a plurality of times from above. 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.
In the present invention, the above-described methods can be used in combination in consideration of productivity and the like. These mechanical surface roughening treatments are preferably performed before the electrochemical surface roughening treatment.

Hereinafter, the brush grain method used suitably as a mechanical roughening process is demonstrated.
The brush grain method generally uses a roller-shaped brush in which a large number of brush hairs such as synthetic resin hair made of synthetic resin such as nylon (trade name), propylene, and vinyl chloride resin are implanted on the surface of a cylindrical body. This is carried out by rubbing one or both of the surfaces of the aluminum plate while spraying a slurry liquid containing an abrasive on a rotating roller brush. Instead of the roller brush and the slurry liquid, a polishing roller which is a roller having a polishing layer on the surface can be used.
When a roller brush is used, the flexural modulus is preferably 10,000 to 40,000 kg / cm ² , more preferably 15,000 to 35,000 kg / cm ² , and the bristle strength is preferably Brush hair that is 500 g or less, more preferably 400 g or less is used. The diameter of the brush bristles is generally 0.2 to 0.9 mm. The length of the brush bristles can be appropriately determined according to the outer diameter of the roller brush and the diameter of the body, but is generally 10 to 100 mm.
In the present invention, it is preferable to use a plurality of nylon brushes, specifically, 3 or more are more preferable, and 4 or more are particularly preferable. By adjusting the number of brushes, the wavelength component of the recess formed on the aluminum plate surface can be adjusted.
The load of the drive motor that rotates the brush is preferably 1 kW plus or more, more preferably 2 kW plus or more, and particularly preferably 8 kW plus or more with respect to the load before the brush roller is pressed against the aluminum plate. By adjusting the load, the depth of the recess formed on the surface of the aluminum plate can be adjusted. The number of rotations of the brush is preferably 100 or more, and particularly preferably 200 or more.

A well-known thing can be used for an abrasive | polishing agent. For example, abrasives such as pumicestone, 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 and silica sand are preferable. In particular, silica sand is preferable in terms of excellent roughening efficiency because it is harder and less likely to break than Pamiston. Further, aluminum hydroxide is suitable for the case where it is not desired to locally generate deep recesses because particles are damaged when an excessive load is applied.
The average particle diameter of the abrasive is preferably 3 to 50 μm, and more preferably 6 to 45 μm in terms of excellent surface roughening efficiency and a narrow graining pitch. By adjusting the average particle size of the abrasive, the depth of the recesses formed on the aluminum plate surface can be adjusted.
For example, the abrasive is suspended in water and used as a slurry. In addition to the abrasive, the slurry liquid may contain a thickener, a dispersant (for example, a surfactant), a preservative, and the like. The specific gravity of the slurry liquid is preferably 0.5-2.
As an apparatus suitable for the mechanical surface roughening treatment, for example, an apparatus described in JP-B-50-40047 can be exemplified.

Hereinafter, an example of a transfer method used as the mechanical roughening process will be described.
In general, the transfer method transfers the unevenness of the rolling roll through an aluminum plate to a rolling roll (transfer roll) embossed by shot blasting, engraving, laser processing or pattern etching, or polished on paper or plastic sheet. This is a method in which a material, glass beads, or the like applied is superimposed on an aluminum plate, rolled and transferred to roughen the aluminum plate.
In addition to the above-described method, the following method can be used for the transfer method.
Method for avoiding problems of transfer roller life and aluminum sheet stretching by setting the transfer roller rolling rate low (Japanese Patent Laid-Open No. 7-205565); Transfer is repeated a plurality of times, preferably four or more times This method eliminates the need for sticking to the processing accuracy such as the cylindricity of the transfer roll, reduces the elongation of the aluminum plate, and provides a sufficiently uniform rough surface as an aluminum support for a printing plate (JP-A-6-55871). ); Random arrangement and uniform distribution by pressing the aluminum plate 1-6 times on a chemically roughened metal surface that is harder than lithographic printing plate aluminum. A method that can make the unevenness of the metal sheet at a low cost (Japanese Patent Laid-Open No. 6-171258); Method (JP-A-6-171256, JP-A-6-171259): Photoresist or plastic resin coated and dried on a metal surface is exposed and irradiated with infrared light, laser or the like to form a resist pattern, and then A method of transferring a sufficiently uniform unevenness (Japanese Patent Laid-Open No. 6-171262) or the like by carrying out chemical etching or the like to produce and transfer a rough surface on a metal surface can be used.

In the transfer method, the size of the projections (surface roughness of the transfer roll) provided on the transfer roll and the like, and the size of the recesses formed on the aluminum plate transferred by the transfer roll (surface of the aluminum plate by the transfer method) (Roughness) is almost the same.
Therefore, in order to form the desired surface roughness on the aluminum plate, a transfer roll having a surface roughness substantially the same as the surface roughness may be used.
The transfer roller is configured by providing fine convex portions on the surface of a roller metal core made of, for example, SUS304, SUS316, SCM steel, SUJ steel, SS41, or the like by thermal spraying, laser, machining, or the like.
In the thermal spraying method, ceramic particles having a particle size of about 10 to 60 μm and ceramic sintered bodies are coated on the roller surface to a thickness of about 0.1 to 0.6 mm by plasma spraying, thermal spraying with a DJ gun, or thermal spraying with a wire. It is obtained by polishing the surface. As the kind of ceramic, oxide ceramics mainly composed of chromium oxide and nitride ceramics mainly composed of silicon nitride are preferable from the viewpoint of strength. Moreover, since the roller surface formed by thermal spraying is rough, it is polished.
On the other hand, the method of forming the convex portion by laser uses the fact that the laser irradiated portion of the roller surface melts and rises, and the laser forms the vertical groove and the horizontal groove on the roller surface in a lattice shape at right angles or at an angle. By doing so, it is possible to form independent protrusions cut out by both grooves. Examples of the laser used include a CO ₂ laser, a YAG laser, and an excimer laser. Moreover, the groove width formed differs depending on the type of laser. Therefore, it is necessary to select the type of laser according to the desired size of the convex portion, and it is necessary to use a laser having a short wavelength such as an excimer laser in order to obtain a transfer roller having a finer uneven shape. Moreover, it is finished with a diamond grindstone, a ceramic grindstone, or a polishing paper containing these.

Similarly, it is also possible to cut square grooves in two directions using a die or a bit on the roller surface to form a square irregularity.
The aluminum plate or aluminum alloy plate is inserted between the transfer roller and a mirror-finished metal roller (backup roll), and is composed of a convex portion of the transfer roller under a linear pressure reduction of about 3 to 30 kg / mm. The uneven pattern is transferred. Details are described in JP-A-7-205565.
The conditions for the composition surface treatment in the transfer method can be appropriately adjusted according to the desired surface roughness.

<Electrochemical roughening treatment>
In the electrochemical surface roughening treatment, an electrolytic solution used for the electrochemical surface roughening treatment using a normal alternating current can be used. Among them, the use of an electrolytic solution mainly composed of hydrochloric acid or nitric acid is preferable so that each of the above factors representing the surface shape satisfies a specific condition.
As the electrolytic surface roughening treatment in the present invention, it is preferable to perform the first and second electrolytic treatments with an alternating waveform current in an acidic solution before and after the cathodic electrolytic treatment. By cathodic electrolysis, hydrogen gas is generated on the surface of the aluminum plate and smut is generated, so that the surface state is made uniform, and uniform electrolytic surface roughening is possible during subsequent electrolysis with alternating waveform current. .
This electrolytic surface roughening treatment can be performed according to, for example, an electrochemical grain method (electrolytic grain method) described in Japanese Patent Publication No. 48-28123 and British Patent No. 896,563. This electrolytic grain method uses a sinusoidal alternating current, but it may be performed using a special waveform as described in JP-A-52-58602. Further, the waveform described in JP-A-3-79799 can also be used. JP-A-55-158298, JP-A-56-28898, JP-A-52-58602, JP-A-52-152302, JP-A-54-85802, JP-A-60-190392, JP-A-58-120531, JP-A-63-176187, JP-A-1-5889, JP-A-1-280590, JP-A-1-118489, JP-A-1-148592, and JP-A-1-17896. JP-A-1-188315, JP-A-1-1549797, JP-A-2-235794, JP-A-3-260100, JP-A-3-253600, JP-A-4-72079, JP-A-4-72098, The methods described in JP-A-3-267400 and JP-A-1-141094 can also be applied. In addition to the above, it is also possible to perform electrolysis using an alternating current having a special frequency that has been proposed as a method of manufacturing an electrolytic capacitor. For example, it is described in US Pat. Nos. 4,276,129 and 4,676,879.

Various electrolyzers and power sources have been proposed. U.S. Pat. No. 4,023,637, JP-A-56-123400, JP-A-57-59770, JP-A-53-12738, JP-A-53. -32821, JP-A 53-32822, JP-A 53-32823, JP-A 55-122896, JP-A 55-13284, JP-A 62-127500, JP-A-1-52100 JP-A-1-52098, JP-A-60-67700, JP-A-1-230800, JP-A-3-257199 and the like can be used.
Also, JP-A-52-58602, JP-A-52-152302, JP-A-53-12738, JP-A-53-12739, JP-A-53-32821, JP-A-53-32822, JP 53-32833, JP 53-32824, JP 53-32825, JP 54-85802, JP 55-122896, JP 55-13284, JP 48-28123, JP-B-51-7081, JP-A-52-13338, JP-A-52-133840, JP-A-52-133844, JP-A-52-133845, JP-A-53-149135 And those described in JP-A No. 54-146234 and the like can also be used.

  As an acidic solution which is an electrolytic solution, in addition to nitric acid and hydrochloric acid, U.S. Pat. Nos. 4,671,859, 4,661,219, 4,618,405, 4,600, 482, 4,566,960, 4,566,958, 4,566,959, 4,416,972, 4,374,710, The electrolyte solution described in each specification of 4,336,113 and 4,184,932 can also be used.

  The concentration of the acidic solution is preferably 0.5 to 2.5% by mass, but it is particularly preferably 0.7 to 2.0% by mass in consideration of use in the smut removal treatment. Moreover, it is preferable that liquid temperature is 20-80 degreeC, and it is more preferable that it is 30-60 degreeC.

  An aqueous solution mainly composed of hydrochloric acid or nitric acid is an aqueous solution of hydrochloric acid or nitric acid having a concentration of 1 to 100 g / L, such as nitric acid compounds having nitrate ions such as aluminum nitrate, sodium nitrate, ammonium nitrate, or aluminum chloride, sodium chloride, ammonium chloride, etc. At least one of the hydrochloric acid compounds having hydrochloric acid ions can be used by adding in a range from 1 g / L to saturation. Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, a silica, may melt | dissolve in the aqueous solution which has hydrochloric acid or nitric acid as a main component. Preferably, a solution obtained by adding aluminum chloride, aluminum nitrate or the like to an aqueous solution of hydrochloric acid or nitric acid having a concentration of 0.5 to 2% by mass so that aluminum ions are 3 to 50 g / L is preferably used.

Further, by adding and using a compound capable of forming a complex with Cu, uniform graining is possible even for an aluminum plate containing a large amount of Cu. Examples of the compound capable of forming a complex with Cu include ammonia; hydrogen atom of ammonia such as methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, cyclohexylamine, triethanolamine, triisopropanolamine, EDTA (ethylenediaminetetraacetic acid), etc. And amines obtained by substituting with a hydrocarbon group (aliphatic, aromatic, etc.); metal carbonates such as sodium carbonate, potassium carbonate, potassium hydrogen carbonate and the like. In addition, ammonium salts such as ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium phosphate, and ammonium carbonate are also included.
The temperature is preferably 10-60 ° C, more preferably 20-50 ° C.

  The AC power supply wave used for the electrochemical surface roughening treatment is not particularly limited, and a sine wave, a rectangular wave, a trapezoidal wave, a triangular wave or the like is used, but a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal wave is particularly preferable. A trapezoidal wave means what was shown in FIG. In this trapezoidal wave, the time (TP) until the current reaches a peak from zero is preferably 0.3 to 3 msec. If it is less than 0.3 msec, processing irregularities such as chatter marks that occur perpendicular to the traveling direction of the aluminum plate are likely to occur. When TP exceeds 3 msec, especially when a nitric acid electrolyte is used, it is easily affected by trace components in the electrolyte typified by ammonium ions and the like that spontaneously increase by electrolytic treatment, and uniform graining is performed. It becomes hard to be broken. As a result, the stain resistance tends to decrease when a lithographic printing plate is obtained.

A duty ratio of trapezoidal wave alternating current of 1: 2 to 2: 1 can be used. However, as described in Japanese Patent Laid-Open No. 5-195300, in an indirect power feeding method in which no conductor roll is used for aluminum, A duty ratio of 1: 1 is preferable.
A trapezoidal AC frequency of 0.1 to 120 Hz can be used, but 50 to 70 Hz is preferable in terms of equipment. If it is lower than 50 Hz, the carbon electrode of the main electrode is likely to be dissolved, and if it is higher than 70 Hz, it is likely to be affected by the inductance component on the power supply circuit and the power supply cost is increased.

  One or more AC power supplies can be connected to the electrolytic cell. As shown in FIG. 3, the current ratio between the AC anode and cathode applied to the aluminum plate facing the main electrode is controlled to achieve uniform graining and to dissolve the carbon of the main electrode. In addition, it is preferable to install an auxiliary anode and divert part of the alternating current. In FIG. 3, 11 is an aluminum plate, 12 is a radial drum roller, 13a and 13b are main poles, 14 is an electrolytic treatment liquid, 15 is an electrolytic solution supply port, and 16 is a slit. , 17 is an electrolyte passage, 18 is an auxiliary anode, 19a and 19b are thyristors, 20 is an AC power source, 40 is a main electrolytic cell, and 50 is an auxiliary anode cell. An anodic reaction that acts on the aluminum plate facing the main electrode by diverting a part of the current value as a direct current to an auxiliary anode provided in a tank separate from the two main electrodes via a rectifier or switching element It is possible to control the ratio between the current value for the current and the current value for the cathode reaction. On the aluminum plate facing the main electrode, the ratio of the amount of electricity involved in the anodic reaction and the cathodic reaction (the amount of electricity at the time of cathode / the amount of electricity at the time of anode) is preferably 0.3 to 0.95.

  As the electrolytic cell, electrolytic cells used for known surface treatments such as a vertical type, a flat type, and a radial type can be used, but a radial type electrolytic cell as described in JP-A-5-195300 is particularly preferable. . The electrolytic solution passing through the electrolytic cell may be parallel to the traveling direction of the aluminum web or may be a counter.

(Nitric acid electrolysis)
Pits having an average opening diameter of 0.5 to 5 μm can be formed by electrochemical surface roughening using an electrolytic solution mainly composed of nitric acid. However, when the amount of electricity is relatively large, the electrolytic reaction is concentrated, and honeycomb pits exceeding 5 μm are also generated.
To obtain such a grain, the total amount of electricity furnished to anode reaction on the aluminum plate up until the electrolysis reaction is completed is preferably from ^{1~1000C / dm 2, 50~300C / dm} 2 It is more preferable that The current density at this time is preferably ²⁰ to 100 A / dm ² .

(Hydrochloric acid electrolysis)
Since hydrochloric acid itself has a strong ability to dissolve aluminum, it is possible to form fine irregularities on the surface with only slight electrolysis. These fine irregularities have an average opening diameter of 0.01 to 0.2 μm and are uniformly generated on the entire surface of the aluminum plate. Such grained total amount of electricity furnished to anode reaction on the aluminum plate up until the electrolysis reaction is completed in order to obtain the, is preferably from 1~100C / dm ^2, in 20~70C / dm ² More preferably. The highest current density is preferably from 10 to 50 A / dm ^2.

In such an electrochemical surface roughening treatment with an electrolytic solution mainly composed of hydrochloric acid, a large crater-like swell is simultaneously formed by increasing the total amount of electricity involved in the anode reaction to 400 to 2000 C / dm ^2. In this case, fine irregularities having an average opening diameter of 0.01 to 0.4 μm are formed on the entire surface by being superimposed on a crater-like wave having an average opening diameter of 10 to 30 μm.

The aluminum plate is preferably subjected to cathodic electrolysis treatment during the first and second electrolytic surface-roughening treatments performed in the electrolytic solution such as nitric acid and hydrochloric acid. By this cathodic electrolysis treatment, smut is generated on the surface of the aluminum plate, and hydrogen gas is generated to enable more uniform electrolytic surface roughening treatment. This cathodic electrolysis treatment is carried out in an acidic solution at a cathode electric quantity of preferably 3 to 80 C / dm ² , more preferably 5 to 30 C / dm ² . If the amount of cathodic electricity is less than 3 C / dm ² , the amount of smut adhesion may be insufficient, and if it exceeds 80 C / dm ² , the amount of smut adhesion may be excessive. Further, the electrolytic solution may be the same as or different from the solution used in the first and second electrolytic surface roughening processes.

<Alkaline etching treatment>
The alkali etching treatment is a treatment for dissolving the surface layer by bringing the aluminum plate into contact with an alkali solution.

  Alkaline etching performed before the electrolytic surface roughening treatment removes rolling oil, dirt, natural oxide film, etc. on the surface of the aluminum plate (rolled aluminum) if mechanical surface roughening treatment is not performed. If the surface of the unevenness generated by the mechanical surface roughening treatment is dissolved, the surface with sharp undulations is smoothed. It is done for the purpose of changing.

If you do not mechanical surface-roughening treatment before the alkali etching treatment, the etching amount is preferably from 0.1 to 10 g / m ^2, and more preferably 1 to 5 g / m ^2. If the etching amount is less than 0.1 g / m ² , rolling oil, dirt, natural oxide film, etc. may remain on the surface, so uniform pits cannot be generated in the subsequent electrolytic surface roughening treatment, resulting in unevenness. May occur. On the other hand, when the etching amount is 1 to 10 g / m ² , the surface rolling oil, dirt, natural oxide film, and the like are sufficiently removed. An etching amount exceeding the above range is economically disadvantageous.

When performing mechanical surface-roughening treatment before the alkali etching treatment, the etching amount is preferably from 3 to 20 g / m ^2, and more preferably 5 to 15 g / m ^2. If the etching amount is less than 3 g / m ² , the unevenness formed by mechanical surface roughening or the like may not be smoothed, and uniform pit formation may not be possible in subsequent electrolytic treatment. In addition, the stain may deteriorate during printing. On the other hand, when the etching amount exceeds 20 g / m ² , the concavo-convex structure may disappear.

The alkali etching treatment performed immediately after the electrolytic surface roughening treatment is performed for the purpose of dissolving the smut generated in the acidic electrolytic solution and dissolving the edge portion of the pit formed by the electrolytic surface roughening treatment. .
Since the pits formed by the electrolytic surface roughening treatment are different depending on the type of the electrolytic solution, the optimum etching amount is also different. However, the etching amount of the alkali etching treatment performed after the electrolytic surface roughening treatment is 0.01 to 5 g / m. ² is preferred. When a nitric acid electrolyte is used, the etching amount needs to be set larger than when a hydrochloric acid electrolyte is used.
When the electrolytic surface roughening treatment is performed a plurality of times, an alkali etching treatment can be performed as necessary after each treatment.

  Examples of the alkali used in the alkaline solution include caustic alkali and alkali metal salts. Specifically, examples of caustic alkali include caustic soda and caustic potash. Examples of the alkali metal salt include alkali metal silicates such as sodium metasilicate, sodium silicate, potassium metasilicate, and potassium silicate; alkali metal carbonates such as sodium carbonate and potassium carbonate; sodium aluminate and alumina. Alkali metal aluminates such as potassium acid; alkali metal aldones such as sodium gluconate and potassium gluconate; dibasic sodium phosphate, dibasic potassium phosphate, primary sodium phosphate, primary potassium phosphate, etc. An alkali metal hydrogen phosphate is mentioned. Among these, a caustic alkali solution and a solution containing both a caustic alkali and an alkali metal aluminate are preferable from the viewpoint of high etching rate and low cost. In particular, an aqueous solution of caustic soda is preferable.

  Although the density | concentration of an alkaline solution can be determined according to the etching amount, it is preferable that it is 1-50 mass%, and it is more preferable that it is 10-35 mass%. When aluminum ions are dissolved in the alkaline solution, the concentration of aluminum ions is preferably 0.01 to 10% by mass, and more preferably 3 to 8% by mass. The temperature of the alkaline solution is preferably 20 to 90 ° C. The treatment time is preferably 1 to 120 seconds.

  Examples of the method of bringing the aluminum plate into contact with the alkaline solution include, for example, a method in which the aluminum plate is passed through a tank containing the alkaline solution, a method in which the aluminum plate is immersed in a tank containing the alkaline solution, The method of spraying on the surface of a board is mentioned.

<Desmut treatment>
After the electrolytic surface roughening treatment or the alkali etching treatment, pickling (desmut treatment) is performed to remove dirt (smut) remaining on the surface. Examples of the acid used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and borohydrofluoric acid.
The desmut treatment is performed, for example, by bringing the aluminum plate into contact with an acidic solution having a concentration of 0.5 to 30% by mass (containing 0.01 to 5% by mass of aluminum ions) such as hydrochloric acid, nitric acid, and sulfuric acid. . Examples of the method of bringing the aluminum plate into contact with the acidic solution include, for example, a method of passing the aluminum plate through a bath containing the acidic solution, a method of immersing the aluminum plate in a bath containing the acidic solution, and an acidic solution containing aluminum. The method of spraying on the surface of a board is mentioned.
In the desmutting treatment, the acidic solution is mainly composed of an aqueous solution mainly composed of nitric acid or an aqueous solution mainly composed of hydrochloric acid discharged in the above-described electrolytic surface-roughening treatment, or sulfuric acid discharged in an anodic oxidation process described later. It is possible to use a waste solution of an aqueous solution.
The liquid temperature in the desmut treatment is preferably 25 to 90 ° C. The processing time is preferably 1 to 180 seconds. Aluminum and aluminum alloy components may be dissolved in the acidic solution used for the desmut treatment.

<Anodizing treatment>
The aluminum plate treated as described above is preferably further subjected to an anodizing treatment. The anodizing treatment can be performed by a method conventionally used in this field. In this case, for example, in a solution having a sulfuric acid concentration of 50 to 300 g / L and an aluminum concentration of 5% by mass or less, an anodized film can be formed by energizing an aluminum plate as an anode. As a solution used for the anodizing treatment, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, amidosulfonic acid and the like can be used alone or in combination of two or more.

  Under the present circumstances, the component normally contained at least in an aluminum plate, an electrode, tap water, groundwater, etc. may be contained in electrolyte solution. Furthermore, the 2nd, 3rd component may be added. Examples of the second and third components herein include metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; Cation such as ammonium ion; anion such as nitrate ion, carbonate ion, chloride ion, phosphate ion, fluoride ion, sulfite ion, titanate ion, silicate ion, borate ion, etc., 0 to 10,000 ppm It may be contained at a concentration of about.

The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be determined unconditionally. In general, however, the electrolyte concentration is 1 to 80% by mass, the solution temperature is 5 to 70 ° C., and the current density is 0.5. ˜60 A / dm ² , voltage 1 to 100 V, electrolysis time 15 seconds to 50 minutes are appropriate, and the amount of anodic oxide film is adjusted as desired.

  Further, JP-A-54-81133, JP-A-57-47894, JP-A-57-51289, JP-A-57-51290, JP-A-57-54300, JP-A-57-136596, JP-A-58-107498, JP-A-60-200366, JP-A-62-136696, JP-A-63-176494, JP-A-4-17697, JP-A-4-280997, JP-A-6-280997 The methods described in JP-A-207299, JP-A-5-24377, JP-A-5-32083, JP-A-5-125597, JP-A-5-195291 and the like can also be used.

  Of these, as described in JP-A-54-12853 and JP-A-48-45303, it is preferable to use a sulfuric acid solution as the electrolytic solution. The sulfuric acid concentration in the electrolytic solution is preferably 10 to 300 g / L (1 to 30% by mass), and the aluminum ion concentration is 1 to 25 g / L (0.1 to 2.5% by mass). It is preferable that it is 2 to 10 g / L (0.2 to 1% by mass). Such an electrolytic solution can be prepared, for example, by adding aluminum sulfate or the like to dilute sulfuric acid having a sulfuric acid concentration of 50 to 200 g / L.

When anodizing is performed in an electrolytic solution containing sulfuric acid, direct current may be applied between the aluminum plate and the counter electrode, or alternating current may be applied.
When a direct current is applied to the aluminum plate, the current density is preferably from 1 to 60 A / dm ^2, and more preferably 5 to 40 A / dm ^2.
In the case where continuous anodizing treatment is performed, a low current of 5 to 10 A / m ² is initially introduced so that current is concentrated on a part of the aluminum plate and so-called “burning” does not occur. It is preferable to increase the current density to 30 to 50 A / dm ² or more as the current is passed at the density and the anodization process proceeds.
When the anodizing treatment is continuously performed, it is preferable that the anodizing process is performed by a liquid power feeding method in which power is supplied to the aluminum plate through an electrolytic solution.
By performing anodizing treatment under such conditions, a porous film having many pores called micropores can be obtained. Usually, the average pore diameter is about 5 to 50 nm, and the average pore density is 300. it is a 800 pieces / μm ² about.

The coating amount of the anodized film is preferably 1 to 5 g / m ² . If it is less than 1 g / m ² , the plate is likely to be scratched. On the other hand, if it exceeds 5 g / m ² , a large amount of electric power is required for production, which is economically disadvantageous. The amount of the anodized film is more preferably 1.5 to 4 g / m ² . Moreover, it is preferable to carry out so that the difference in the amount of the anodized film between the center portion of the aluminum plate and the vicinity of the edge portion is 1 g / m ² or less.

As the electrolysis apparatus used for the anodizing treatment, those described in JP-A-48-26638, JP-A-47-18739, JP-B-58-24517, and the like can be used.
Among these, the apparatus shown in FIG. 4 is preferably used. FIG. 4 is a schematic view showing an example of an apparatus for anodizing the surface of an aluminum plate. In the anodizing apparatus 410, the aluminum plate 416 is conveyed as shown by the arrows in FIG. In the power supply tank 412 in which the electrolytic solution 418 is stored, the aluminum plate 416 is charged to (+) by the power supply electrode 420. The aluminum plate 416 is conveyed upward by the roller 422 in the power supply tank 412, changed in direction downward by the nip roller 424, and then conveyed toward the electrolytic treatment tank 414 in which the electrolytic solution 426 is stored. The direction is changed horizontally. Next, the aluminum plate 416 is charged to (−) by the electrolytic electrode 430 to form an anodized film on the surface thereof, and the aluminum plate 416 exiting the electrolytic treatment tank 414 is conveyed to a subsequent process. In the anodizing apparatus 410, the roller 422, the nip roller 424, and the roller 428 constitute a direction changing means. By 428, it is conveyed into a mountain shape and an inverted U shape. The feeding electrode 420 and the electrolytic electrode 430 are connected to a DC power source 434.

  A feature of the anodizing apparatus 410 in FIG. 4 is that the feeding tank 412 and the electrolytic treatment tank 414 are partitioned by a single tank wall 432, and the aluminum plate 416 is conveyed in a mountain shape and an inverted U shape between the tanks. It is in. As a result, the length of the aluminum plate 416 in the inter-tank portion can be minimized. Therefore, the overall length of the anodizing apparatus 410 can be shortened, so that the equipment cost can be reduced. In addition, by conveying the aluminum plate 416 in a mountain shape and an inverted U shape, it is not necessary to form an opening for allowing the aluminum plate 416 to pass through the tank walls of the tanks 412 and 414. Therefore, since the liquid feeding amount required to maintain the liquid level height in each tank 412 and 414 at a required level can be suppressed, the operating cost can be reduced.

<Sealing treatment>
In this invention, you may perform the sealing process which seals the micropore which exists in an anodic oxide film as needed. The sealing treatment can be performed according to a known method such as boiling water treatment, hot water treatment, steam treatment, sodium silicate treatment, nitrite treatment, ammonium acetate treatment and the like. For example, Japanese Patent Publication No. 56-12518, Japanese Patent Application Laid-Open No. 4-4194, Japanese Patent Application No. 4-33952 (Japanese Patent Application Laid-Open No. 5-202496), Japanese Patent Application No. 4-33951 (Japanese Patent Application Laid-Open No. No. 179482) etc. may be used for sealing treatment.

<Hydrophilic treatment>
A hydrophilization treatment may be performed after the anodizing treatment or the sealing treatment. Examples of the hydrophilization treatment include treatment with potassium fluorozirconate described in US Pat. No. 2,946,638 and phosphomolybdate described in US Pat. No. 3,201,247. Treatment, alkyl titanate treatment described in British Patent 1,108,559, polyacrylic acid treatment described in German Patent 1,091,433, German Patent 1,134, No. 093 and British Patent No. 1,230,447, polyvinylphosphonic acid treatment, Japanese Patent Publication No. 44-6409, phosphonic acid treatment, US Pat. No. 3,307,951 Phytic acid treatment described in the specification of JP, No. 58-16893 and JP-A No. 58-18291 Treatment with a salt of a molecular compound and a divalent metal, as described in US Pat. No. 3,860,426, hydrophilic cellulose (eg, zinc acetate) containing a water-soluble metal salt (eg, zinc acetate) Carboxymethyl cellulose) is provided with a primer layer, and a water-soluble polymer having a sulfo group described in JP-A-59-101651.

Further, phosphates described in JP-A No. 62-019494, water-soluble epoxy compounds described in JP-A No. 62-033692, and JP-A No. 62-097892 Phosphate-modified starch, diamine compounds described in JP-A-63-056498, amino acid inorganic or organic acids described in JP-A-63-130391, JP-A-63-145092 Organic phosphonic acids containing carboxy group or hydroxy group, compounds having amino group and phosphonic acid group described in JP-A-63-165183, and JP-A-2-316290 Specific carboxylic acid derivatives, phosphate esters described in JP-A-3-215095, JP-A-3-261592 Compounds having one amino group and one oxygen acid group of phosphorus described in the publication, phosphoric esters described in JP-A-3-215095, and JP-A-5-246171 Aliphatic or aromatic phosphonic acids such as phenylphosphonic acid, compounds containing S atoms such as thiosalicylic acid described in JP-A-1-307745, phosphorus described in JP-A-4-282737 Examples of the treatment include undercoating using a compound having a group of oxygen acids.
Further, coloring with an acid dye described in JP-A-60-64352 can also be performed.

  Hydrophilicity can also be achieved by soaking in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or by applying a hydrophilic vinyl polymer or hydrophilic compound to form a hydrophilic primer layer. It is preferable to carry out the treatment.

Hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. It can be performed according to methods and procedures.
Examples of the alkali metal silicate include sodium silicate, potassium silicate, and lithium silicate. The aqueous solution of alkali metal silicate may contain an appropriate amount of sodium hydroxide, potassium hydroxide, lithium hydroxide or the like.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVA) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Examples of the Group 4 (Group IVA) metal salt include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVA) metal salts are used alone or in combination of two or more.

The amount of Si adsorbed by the alkali metal silicate treatment can be measured with a fluorescent X-ray analyzer, and the amount of adsorption is preferably about 1.0 to 15.0 mg / m ² .
By this alkali metal silicate treatment, the effect of improving the dissolution resistance to the alkaline developer on the surface of the lithographic printing plate support is obtained, and the dissolution of the aluminum component into the developer is suppressed, and the developer fatigue It is possible to reduce the occurrence of development residue due to the above.

The hydrophilic treatment by forming a hydrophilic undercoat layer can also be performed according to the conditions and procedures described in JP-A Nos. 59-101651 and 60-149491.
Examples of the hydrophilic vinyl polymer used in this method include polyvinyl sulfonic acid, sulfo group-containing vinyl polymerizable compounds such as p-styrene sulfonic acid having a sulfo group, and ordinary vinyl polymerization such as (meth) acrylic acid alkyl ester. And a copolymer with a functional compound. Examples of hydrophilic compounds that may be used in this method include, -NH ₂ group, compounds having at least one selected from the group consisting of -COOH group and sulfo group.

<Washing treatment>
It is preferable to perform water washing after the completion of the above-described processes. For washing, pure water, well water, tap water, or the like can be used. A nip device may be used to prevent the processing liquid from being brought into the next process.

<Aluminum plate (rolled aluminum)>
In order to obtain the lithographic printing plate support of the present invention, a known aluminum plate can be used. The aluminum plate used in the present invention is a metal whose main component is dimensionally stable aluminum, and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements can also be used.

  In the present specification, various substrates made of the above-described aluminum or aluminum alloy are generically used as an aluminum plate. The foreign elements that may be contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium, and the content of the foreign elements in the alloy is 10% by mass or less. It is.

  Thus, the composition of the aluminum plate used in the present invention is not specified. For example, a conventionally known material described in the fourth edition of the Aluminum Handbook (1990, published by the Light Metal Association), for example, JIS Al-Mn aluminum plates such as A1050, JIS A1100, JIS A1070, JIS A3004 containing Mn, and internationally registered alloy 3103A can be appropriately used. For the purpose of increasing the tensile strength, an Al—Mg alloy or an Al—Mn—Mg alloy (JIS A3005) in which 0.1% by mass or more of magnesium is added to these aluminum alloys can also be used. Furthermore, an Al—Zr alloy or an Al—Si alloy containing Zr or Si 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 in the range 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 produced. 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 the soaking process, 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 0.5 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 productivity, it is preferably performed in a continuous coil state. Further, a slitter line may be used for processing to 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 thickness of 5 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.
The strength of the aluminum plate is preferably such 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 strength of the aluminum plate is required, aluminum material added with Mg or Mn can be used. 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.

  The thickness of the aluminum plate used in the present invention is about 0.1 to 0.6 mm, preferably 0.15 to 0.4 mm, and more preferably 0.2 to 0.3 mm. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, the user's desires, and the like.

[Lithographic printing plate precursor]
The lithographic printing plate support obtained by the present invention can be provided with an image recording layer to form the lithographic printing plate precursor of the present invention. A photosensitive composition is used for the image recording layer.
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 substance (hereinafter, this composition and an image recording layer using the same). ), A thermal negative photosensitive composition containing a curable compound and a photothermal conversion substance (hereinafter also referred to as “thermal negative type”), a photopolymerizable photosensitive composition (hereinafter referred to as “thermal positive type”). , Also referred to as “photopolymer type”), negative photosensitive composition containing diazo resin or photocrosslinking resin (hereinafter also referred to as “conventional negative type”), and positive photosensitive composition containing quinonediazide compound. Product (hereinafter also referred to as "conventional positive type"), photosensitive composition that does not require a special development step (hereinafter referred to as As the referred to as "non-treatment type".), And the like. Hereinafter, these suitable photosensitive compositions will be described.

<Thermal positive type>
<Photosensitive layer>
The thermal positive type photosensitive composition contains an alkali-soluble polymer compound 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, which effectively eliminates the interaction that reduces the alkali solubility of alkali-soluble polymer compounds. 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, and examples thereof include phenol-formaldehyde resins, m-cresol-formaldehyde resins, p-cresol-formaldehyde resins, m- / p-mixed cresol-formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) mixed-formaldehyde resin (phenol-cresol-formaldehyde co-condensation resin) and other novolak resins Are preferable.
Furthermore, a polymer compound described in JP-A No. 2001-305722 (particularly [0023] to [0042]), and a 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-A No. 2001-305722 are particularly preferable.

The thermal positive type photosensitive composition can contain a dissolution inhibitor. As the dissolution inhibitor, for example, a dissolution inhibitor as described in JP-A-2001-305722, [0053] to [0055] is 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 as described in [0056] to [0060] of JP-A No. 2001-305722 are preferable.
The photosensitive composition described in detail by Unexamined-Japanese-Patent No. 2001-305722 is preferably used also in respects other than the above.

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 for 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 [0062] to [0085] of JP-A-2002-3233769 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>
It is preferable to provide an intermediate layer 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 radically 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.

  The additive described in [0061] to [0068] of JP-A No. 2001-133969 is contained in the thermal negative photosensitive composition (for example, a surfactant for improving coatability). 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 crosslinking layer comprises a photothermal conversion substance, a thermal acid generator, a compound that crosslinks with an acid that is a curable compound (crosslinking agent), and an alkali-soluble polymer compound that can react with the crosslinking 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 novolak resins and polymers having a hydroxyaryl group in the side chain.

<Photopolymer type>
The photopolymerization type photosensitive composition contains an addition polymerizable compound, a photopolymerization initiator, and a polymer binder.
As the addition polymerizable compound, an ethylenically unsaturated bond-containing compound capable of addition polymerization is preferably exemplified. The ethylenically unsaturated bond-containing compound is a compound having a terminal ethylenically unsaturated bond. Specifically, for example, it has a chemical form such as a monomer, a prepolymer, and a mixture thereof. Examples of monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, maleic acid) and aliphatic polyhydric alcohol compounds, amides of unsaturated carboxylic acids and aliphatic polyvalent amine compounds. Is mentioned.
Moreover, as an addition polymerizable compound, a urethane type addition polymerizable compound is also preferably exemplified.

As the photopolymerization initiator, various photopolymerization initiators or a combination system (photoinitiation system) of two or more photopolymerization initiators can be appropriately selected depending on the wavelength of the light source to be used. For example, the initiation system described in JP-A-2001-22079, [0021] to [0023] is preferable.
The polymer binder not only functions as a film forming agent for the photopolymerization type photosensitive composition, but is soluble or swellable in alkaline water because the image recording layer needs to be dissolved in an alkaline developer. An organic high molecular polymer is used. As such an organic polymer, those described in JP-A-2001-22079, [0036] to [0063] are preferably exemplified.

  In the photopolymer type photopolymerization type photosensitive composition, additives described in JP-A-2001-22079, [0079] to [0088] (for example, a surfactant for improving coatability) , Colorants, plasticizers, thermal polymerization inhibitors).

Further, it is preferable to provide an oxygen-blocking protective layer on the photopolymer type image recording layer in order to prevent the oxygen polymerization inhibiting action. Examples of the polymer contained in the oxygen barrier protective layer include polyvinyl alcohol and copolymers thereof.
Furthermore, it is also preferable to provide an intermediate layer or an adhesive layer as described in [0124] to [0165] of JP-A-2001-228608.

<Conventional negative type>
The conventional negative-type photosensitive composition contains a diazo resin or a photocrosslinking resin. Among these, a photosensitive composition containing a diazo resin and an alkali-soluble or swellable polymer compound (binder) is preferable.
Examples of the diazo resin include a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound such as formaldehyde; a condensate of p-diazophenylamines and formaldehyde with a hexafluorophosphate or a tetrafluoroborate. Organic solvent-soluble diazo resin inorganic salts which are reaction products of In particular, a high molecular weight diazo compound containing 20 mol% or more of a hexamer described in JP-A-59-78340 is preferable.
Examples of the binder include a copolymer containing acrylic acid, methacrylic acid, crotonic acid, or maleic acid as an essential component. Specifically, multi-component copolymers of monomers such as 2-hydroxyethyl (meth) acrylate, (meth) acrylonitrile, and (meth) acrylic acid as described in JP-A-50-118802, Examples thereof include multi-component copolymers composed of alkyl acrylate, (meth) acrylonitrile and unsaturated carboxylic acid as described in JP-A-56-4144.

  The conventional negative type photosensitive composition has, as additives, the bake-out agent, dye, and flexibility and abrasion resistance described in JP-A-7-281425, [0014] to [0015]. It is preferable to contain a plasticizer for imparting, a compound such as a development accelerator, and a surfactant for improving coatability.

  Under the conventional negative type photosensitive layer, an intermediate layer containing a polymer compound having a component having an acid group and a component having an onium group as described in JP-A-2000-105462 is provided. Is preferred.

<Conventional positive type>
The conventional positive-type photosensitive composition contains a quinonediazide compound. Among these, a photosensitive composition containing an o-quinonediazide compound and an alkali-soluble polymer compound is preferable.
Examples of the o-quinonediazide compound include esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and phenol-formaldehyde resin or cresol-formaldehyde resin, described in US Pat. No. 3,635,709. And esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and pyrogallol-acetone resin.
Examples of the alkali-soluble polymer compound include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde co-condensation resin, polyhydroxystyrene, N- (4-hydroxyphenyl) methacrylamide copolymer, A carboxy group-containing polymer described in JP-A-7-36184, an acrylic resin containing a phenolic hydroxy group as described in JP-A-51-34711, and described in JP-A-2-866 Examples thereof include acrylic resins having a sulfonamide group and urethane resins.

  Conventional positive type photosensitive compositions include compounds such as sensitivity modifiers, printing agents, dyes and the like described in JP-A-7-92660, [0024] to [0027] as additives. It is preferable to contain a surfactant for improving the coating property as described in [0031] of Kaihei 7-92660.

  Under the conventional positive type photosensitive layer, it is preferable to provide an intermediate layer similar to the intermediate layer suitably used for the above-described conventional negative type.

<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.

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

[Plate making method (lithographic printing plate production method)]
The lithographic printing plate precursor using the lithographic printing plate support obtained by the present invention is made into a lithographic printing plate by various treatment methods according to the image recording layer.
Examples of the active 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.

After the above exposure, if the image recording layer is any of thermal positive type, thermal negative type, conventional negative type, conventional positive type, and photopolymer type, after exposure, it is developed using a developer to produce a lithographic printing plate. It is preferable to obtain.
The developer is preferably an alkaline developer, and more preferably an alkaline aqueous solution that does not substantially contain an organic solvent.
Moreover, the developing solution which does not contain alkali metal silicate substantially is also preferable. As a method for developing using a developer substantially not containing an alkali metal silicate, a method described in detail in JP-A-11-109637 can be used.
A developer containing an alkali metal silicate can also be used.

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 (Examples 1-11 and Comparative Examples 1-6)
Si: 0.08% by mass, Fe: 0.3% by mass, Cu: 0.015% by mass, Ti: 0.020% by mass, and the balance is prepared using an aluminum alloy of Al and inevitable impurities. Then, after performing the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm was produced by a DC casting method. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, it was kept soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing at 500 degreeC using a continuous annealing machine, it finished in thickness 0.24mm by cold rolling, and obtained the aluminum plate. After making this aluminum plate width 1030mm, it used for the surface treatment shown below.

<Surface treatment>
The following various surface treatments (a) to (k) were continuously performed on the aluminum plate to obtain lithographic printing plate supports of Examples 1 to 11 and Comparative Examples 1 to 6. After each treatment and water washing, the liquid was drained with a nip roller.
In Table 1, when the following various surface treatments are performed, “treatment” or the conditions thereof are indicated, and when not performed, “untreated” is indicated, and the same surface treatment is performed in all examples and comparative examples. When performed under the same conditions, it is not shown in Table 1.

Hereinafter, each of the surface treatments (a) to (k) will be described.
(A) Mechanical roughening treatment (brush grain method)
Using an apparatus as schematically shown in FIG. 1, an aqueous suspension (specific gravity 1.1 g / cm ³ ) of an abrasive (pamis, median diameter 25 μm) is supplied as a polishing slurry to the surface of the aluminum plate. However, a mechanical surface roughening treatment was performed with a rotating roller-like nylon brush. In FIG. 1, 1 is an aluminum plate, 2 and 4 are roller-like brushes (bundling brushes in this embodiment), 3 is an abrasive slurry, and 5, 6, 7 and 8 are support rollers.
The material of the nylon brush was 6 · 10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 400 mm. Although only two rotating brushes are shown in FIG. 1, three rotating brushes were actually used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 10 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The number of rotations of the brush was 250 rpm (first brush), 200 rpm (second brush), and 200 rpm (third brush) in order from the upstream side in the conveyance direction of the aluminum plate.

(B) Alkaline etching treatment The alkali etching treatment was performed by spraying an aqueous solution of caustic soda having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 5% by mass with an aluminum dissolution amount shown in Table 1. Then, water washing by spraying was performed. The temperature for the alkali etching treatment was 70 ° C.

(C) Desmut treatment In the desmut treatment, a desmut treatment was performed by spraying with an aqueous nitric acid solution having a concentration of 1% by mass (liquid temperature 30 ° C.), and then washing with water by spraying was performed. In addition, as a nitric acid aqueous solution, the waste liquid of the process (nitric acid electrolysis process) which performs an electrochemical roughening process using alternating current in the nitric acid aqueous solution mentioned later is used.

(D) Electrochemical roughening treatment (nitric acid electrolysis)
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power supply waveform is the waveform shown in FIG. 2, the time TP until the current value reaches the peak from zero is 0.8 msec, the duty ratio is 1: 1, a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 3 was used.
The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. The amount of electricity in the nitric acid electrolysis was set to the value shown in Table 1 as the total amount of electricity when the aluminum plate was the anode.
Then, water washing by spraying was performed.

(E) Alkaline etching treatment The alkali etching treatment was carried out by spraying a caustic soda aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 5 mass% with an aluminum dissolution amount shown in Table 1. Then, water washing by spraying was performed.

(F) Desmut treatment Desmut treatment was performed at a temperature of 60 ° C. for 10 seconds using a solution obtained by dissolving 5 g / L of aluminum ions in a 300 g / L sulfuric acid aqueous solution. Then, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

(G) Electrochemical roughening treatment (hydrochloric acid electrolysis)
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The liquid temperature was 50 ° C. The AC power supply waveform is the waveform shown in FIG. 2, the time TP until the current value reaches the peak from zero is 0.8 msec, the duty ratio is 1: 1, a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 3 was used.
The current density was 25 A / dm ² at the peak current value.
The electrolyte used for hydrochloric acid electrolysis is a 0.5% by mass aqueous solution of hydrochloric acid (containing 0.5% by mass of aluminum ions). The values shown in the table were used.
Then, water washing by spraying was performed.

(H) Alkaline etching treatment The alkali etching treatment was performed by spraying a caustic soda aqueous solution having a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass with an aluminum dissolution amount shown in Table 1. Then, water washing by spraying was performed.
When the aluminum dissolution amount was 1.0 g / m ² (Comparative Example 6), a caustic soda aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 5 mass% was used instead of the caustic soda aqueous solution.

(I) Desmutting treatment Desmutting treatment was performed at a temperature of 60 ° C. for 10 seconds using a solution obtained by dissolving 5 g / L of aluminum ions in a 300 g / L aqueous solution of sulfuric acid. Then, the liquid was drained with a nip roller, washed with water, and further drained with a nip roller.

(J) Anodizing treatment Anodizing treatment was performed under the following conditions.
Anodization was performed using a direct current electrolysis anodizing apparatus having the structure shown in FIG. 4 to obtain a lithographic printing plate support. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 15% by mass (containing 0.5% by mass of aluminum ions) and a temperature of 38 ° C. Then, water washing by spraying was performed. The final oxide film amount was 2.5 g / m ² .

(K) Silicate treatment The silicate treatment was performed under the following conditions.
No. 3 sodium silicate aqueous solution (Na ₂ O: SiO ₂ = 1: 3, SiO ₂ content 30 mass%, manufactured by Nippon Chemical Industry Co., Ltd., concentration 1 mass%) at 35 ° C. was immersed for 10 seconds. Then, the water washing by the spray using well water was performed.

2. Calculation of surface shape factor of lithographic printing plate support About the surface of the lithographic printing plate support obtained above, ΔS ⁵⁰ , a45 ^{50 (0.2-2)} and ΔS ^{5 (0.02-0.2 )} were obtained as follows. ⁾
The results are shown in Table 2.

(1) Measurement of surface shape by atomic force microscope In order to obtain ΔS ⁵⁰ , a45 ^{50 (0.2-2)} and ΔS ^{5 (0.02-0.2)} , an atomic force microscope (SPA300 / SPI3800N, manufactured by Seiko Instruments Inc.) was used. The surface shape was measured to obtain three-dimensional data.
The planographic printing plate support is cut to a size of 1 cm square, set on a horizontal sample stage on a piezo scanner, and the cantilever is approached to the sample surface. Scanning was performed, and the unevenness of the sample was captured by the displacement of the piezo in the Z direction. A piezo scanner that can scan 150 μm in the XY direction and 10 μm in the Z direction was used. A cantilever having a resonance frequency of 120 to 400 kHz and a spring constant of 12 to 90 N / m (SI-DF20, manufactured by Seiko Instruments Inc.) was used and measured in a DFM mode (Dynamic Force Mode). Further, the reference plane was obtained by correcting the slight inclination of the sample by least-square approximation of the obtained three-dimensional data.
At the time of measurement, ΔS ⁵⁰ and a45 ^{50 (0.2-2)} were measured at 512 × 512 points of 50 μm square on the surface. The resolution in the XY direction was 0.1 μm, the resolution in the Z direction was 0.15 nm, and the scan speed was 50 μm / sec.
For ΔS ^{5 (0.02-0.2)} , 512 × 512 points were measured for 5 μm ^square on the surface. The resolution in the XY direction was 0.01 μm, the resolution in the Z direction was 0.15 nm, and the scan speed was 5 μm / sec.

(2) Correction of three-dimensional data For calculation of ΔS ⁵⁰ , three-dimensional data based on the measurement of 50 μm □ of the surface obtained in (1) above was used as it was.
For the calculation of a45 ^{50 (0.2-2)} , a component having a wavelength of 0.2 μm or more and 2 μm or less extracted from three-dimensional data based on the surface measurement of 50 μm □ obtained in (1) above was used. Extraction of components having a wavelength of 0.2 μm or more and 2 μm or less is performed by performing a fast Fourier transform on the three-dimensional data obtained in (1) above to obtain a frequency distribution, and then a component having a wavelength less than 0.2 μm and a wavelength exceeding 2 μm. After removing the components, the inverse Fourier transform was performed.
In addition, ΔS ^{5 (0.02-0.2)} is calculated by extracting a component having a wavelength of 0.02 μm or more and 0.2 μm or less from three-dimensional data based on the surface measurement of 5 μm □ obtained in (1) above. Using. Extraction of components having a wavelength of 0.02 μm or more and 0.2 μm or less is performed by performing a fast Fourier transform on the three-dimensional data obtained in (1) above to obtain a frequency distribution, and then a component having a wavelength of less than 0.02 μm and a wavelength of 0 After removing components exceeding 2 μm, the inverse Fourier transform was performed.

(3) Calculation of each factor (i) ΔS ⁵⁰
Using the three-dimensional data (f (x, y)) obtained in (1) above, three adjacent points are extracted, the sum of the areas of the minute triangles formed by the three points is obtained, and the actual area S _x ⁵⁰ . The surface area ratio ΔS ⁵⁰ was determined by the above formula (1) from the obtained real area S _x ⁵⁰ and the geometric measurement area S ₀ ⁵⁰ .

(Ii) a45 ^{50 (0.2-2)}
Using three-dimensional data (f (x, y)) obtained by correcting in (2) above, each reference point is formed by three points in the predetermined direction (for example, right and bottom). The angle formed between the small triangle formed and the reference plane was calculated for each reference point. The number of reference points whose inclination of the micro triangle is 45 degrees or more is obtained by subtracting the number of all reference points (the number of all data 512 × 512 points and the number of points that do not have two adjacent points in a predetermined direction). In other words, the area ratio a45 ^{50 (0.2-2)} of the portion having the inclination of 45 degrees or more was calculated by dividing by 511 × 511 points).

(Iii) ΔS ^{5 (0.02-0.2)}
Using the three-dimensional data (f (x, y)) obtained by correcting in (2) above, three adjacent points are extracted, and the total area of the micro triangles formed by the three points is obtained. The area was S _x ^{5 (0.02-0.2)} . The surface area ratio ΔS ^{5 (0.02-0.2)} was obtained from the obtained actual area S _x ^{5 (0.02-0.2)} and the geometric measurement area S ₀ ⁵ by the above formula (2).

In addition, the number of local deep portions having a depth of 4 μm or more present on the surface is scanned with a resolution of 0.01 μm on a surface of 400 μm × 400 μm in a non-contact manner using a laser microscope (Micromap 520, manufactured by Ryoka System Co., Ltd.). Thus, three-dimensional data was obtained, and the number of recesses having a depth of 4 μm or more was counted in the three-dimensional data. The measurement was performed at five points per sample, and the average value was obtained.
As the laser microscope, in addition to the one used above, for example, an ultra-deep shape measuring microscope VK5800 manufactured by KEYENCE can be used in the same manner.

3. Preparation of a lithographic printing plate precursor A lithographic printing plate precursor was obtained by providing each of the lithographic printing plate supports obtained above with thermal positive type image recording layers A and B as follows. Before providing the image recording layers A and B, an undercoat layer was provided as described later.

<Formation of undercoat layer>
On the lithographic printing plate support after the silicate treatment, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form a coating film of the undercoat layer. The coating amount of the coating film after drying was 10 mg / m ² .

<Undercoat liquid composition>
・ The following polymer compound 0.2g
・ Methanol 100g
・ Water 1g

<Formation of image recording layer A>
The image recording layer A is a single-layer thermal positive type image recording layer, and was formed as follows.
The heat-sensitive layer coating solution having the following composition was prepared, the lithographic printing plate support provided with a subbing layer, the heat-sensitive layer coating solution coating amount after drying (the heat-sensitive layer coating weight) in 1.7 g / m ² This was coated and dried to form a heat-sensitive layer (single-layer type thermal positive type image recording layer) to obtain a lithographic printing plate precursor.

<Thermosensitive layer coating solution composition>
・ Novolak resin (m-cresol / p-cresol = 60/40, weight average molecular weight 7,000, containing 0.5% by mass of unreacted cresol) 1.0 g
-Cyanine dye A 0.1 g represented by the following structural formula
・ Tetrahydrophthalic anhydride 0.05g
・ 0.002 g of p-toluenesulfonic acid
-Ethyl violet counter ion with 6-hydroxy-β-naphthalenesulfonic acid 0.02 g
-Fluorosurfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.) 0.05g
・ Methyl ethyl ketone 12g

<Formation of image recording layer B>
The image recording layer B is a multilayer-type thermal positive type image recording layer, and was formed as follows.
A coating solution for the first layer having the following composition was prepared, and the coating amount after drying the coating solution for the first layer was 0.85 g / m ² on the lithographic printing plate support on which the undercoat layer was formed. The first layer was formed by setting Wind Control to 7 using PERFECT OVEN PH200 manufactured by Tabai Co., Ltd. and drying at 140 ° C. for 50 seconds. Next, a coating solution for the second layer having the following composition was prepared, and the coating amount after drying the coating solution for the second layer was 0.15 g / m ^{2 on} the lithographic printing plate support on which the first layer was formed. And a second layer was formed by drying at 120 ° C. for 60 seconds to obtain a lithographic printing plate precursor having a multilayer thermal positive type image recording layer.

<Coating solution composition for first layer>
N- (4-aminosulfonylphenyl) methacrylamide / acrylonitrile / methyl methacrylate (molar ratio 36/34/30, weight average molecular weight 50,000, acid value 2.65) 2.133 g
-Cyanine dye A represented by the above formula 0.109 g
・ 4,4'-bishydroxyphenylsulfone 0.126g
・ Tetrahydrophthalic anhydride 0.190g
・ 0.008 g of p-toluenesulfonic acid
・ 3-methoxy-4-diazodiphenylamine hexafluorophosphate 0.030 g
・ The counter ion of ethyl violet is changed to 6-hydroxynaphthalene sulfone 0.10 g
-Fluorosurfactant (Megafac F-176, manufactured by Dainippon Ink & Chemicals, 20% by weight solution, for improving coated surface) 0.035 g (as a solution)
・ Methyl ethyl ketone 25.38g
・ 13.0 g of 1-methoxy-2-propanol
・ Γ-butyrolactone 13.2 g

<Coating solution composition for second layer>
-M, p-cresol-novolak resin (m / p ratio = 6/4, weight average molecular weight 4,500, containing 0.8% by mass of unreacted cresol) 0.2846 g
-Cyanine dye A represented by the above formula 0.075 g
・ Behenamide 0.060g
-Fluorosurfactant (Megafac F-176, manufactured by Dainippon Ink & Chemicals, Inc., 20% by mass solution, for improving coating surface condition) 0.022 g (as a solution)
-Fluorosurfactant (Megafac MCF-312, manufactured by Dainippon Ink and Chemicals, 30% by weight solution, for image formation improvement) 0.120 g (as a solution)
・ Methyl ethyl ketone 15.1g
-1-methoxy-2-propanol 7.7g

4). Exposure and Development Treatment Each lithographic printing plate precursor obtained above was subjected to image exposure and development treatment by the following method to obtain a lithographic printing plate.

Imagewise exposure of a lithographic printing plate precursor using a TrendSetter 3244 manufactured by CREO equipped with a semiconductor laser with an output of 500 mW and a wavelength of 830 nm and a beam diameter of 17 μm (1 / e ² ) at a main scanning speed of 5 m / sec and a plate surface energy amount of 140 mJ / cm ² did. Incidentally, for the evaluation of pepper-like residual film to be described later, we were prepared samples was exposed by changing the plate surface energy amount to 20~140mJ / cm ² to 20 mJ / cm ² intervals.
Thereafter, an aqueous solution containing 5.0% by mass of a potassium salt composed of D-sorbite / potassium oxide K ₂ O, which is a combination of a non-reducing sugar and a base, and 0.015% by mass of Orphine AK-02 (manufactured by Nissin Chemical). Development processing was performed using an alkaline developer (Developer 1) in which 1.0 g of C ₁₂ H ₂₅ N (CH ₂ CH ₂ COONa) ₂ was added to 1 L. The development processing was performed using an automatic processor PS900NP (Fuji Photo Film Co., Ltd.) filled with the developer 1 at a development temperature of 25 ° C. for 12 seconds. After completion of the development treatment, a lithographic printing plate in which plate making was completed was obtained through a water washing step and treatment with a gum (GU-7 (1: 1)).

5). Evaluation of lithographic printing plate The lithographic printing plate obtained above was evaluated for printing durability, cleaner printing durability, stain resistance and the presence or absence of the occurrence of a pot-like residual film by the following methods.
(1) Printing durability With a SPRINT printer manufactured by Komori Corporation, printing was performed using DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals. The printing durability was evaluated based on the number of printed sheets at the recognized time.
The results of the planographic printing plate precursor provided with the image recording layer B are shown in Table 2.

(2) Cleaner printing durability Printing was performed under the same conditions as in the evaluation of printing durability, and the solid image portion was sponged using a plate cleaner solution (multi cleaner, manufactured by Fuji Photo Film Co., Ltd.) 5000 sheets Each time printing was performed, washing was performed, and evaluation was performed based on the number of printed sheets until the solid image portion started to be faintly thinned.
The results of the planographic printing plate precursor provided with the image recording layer B are shown in Table 2.

(3) Dirt resistance (ground dirt)
Using a Mitsubishi diamond type F2 printing machine (manufactured by Mitsubishi Heavy Industries, Ltd.), printing was performed using Leo echo purple ink, and the blanket stain (ground stain) after printing 10,000 sheets was visually evaluated.
The results of the planographic printing plate precursor provided with the image recording layer B are shown in Table 2. In Table 2, the stain resistance was evaluated in three stages of “◯”, “Δ”, and “×” in order from the one with the superior stain resistance according to the degree of stain on the blanket. If the evaluation is “Δ” or more, it is at a practical level as a lithographic printing plate having excellent stain resistance.

(4) Presence or absence of pot-like residual film Non-image areas after development of samples exposed with each plate surface energy amount were observed with an optical microscope at a magnification of 100 times, and the presence or absence of a pot-like residual film in an area of 1 mm square was examined. It was. The pot-like residual film was evaluated based on the minimum value of the plate surface energy amount of the sample in which the pot-like residual film was not observed.
The results of the planographic printing plate precursor provided with the image recording layer B are shown in Table 2. In Table 2, “O”, “Δ”, and “X” were assigned in order from the smallest to the largest plate energy amount.

As is apparent from Table 2, the surface area ratio ΔS ⁵⁰ and the steepness a45 ^{50 (0.2-2 (0.2-2)} obtained from three-dimensional data obtained by measuring 512 × 512 points of 50 μm □ of the surface using an atomic force microscope. ⁾ , And the surface area ratio ΔS ^{5 (0.02-0.2)} obtained from the three-dimensional data obtained by measuring 512 × 512 points on the surface of 5 μm □ using an atomic force microscope satisfies the specific conditions. The lithographic printing plate precursor of the present invention using the lithographic printing plate support (Examples 1 to 11) is excellent in printing durability and stain resistance when used as a lithographic printing plate, and in cleaner printing durability. Also excellent.
Further, the planographic printing plate of the present invention using the support for a planographic printing plate of the present invention (Examples 1 to 10) wherein the number of local deep portions having a depth of 4 μm or more present on the surface is 6 or less per 400 μm × 400 μm. In addition to the above-described properties, the printing plate precursor is unlikely to generate a pot-like residual film.

  In the lithographic printing plate precursor provided with the image recording layer A, as in the case of the lithographic printing plate precursor provided with the image recording layer B, the printing durability, the cleaner printing resistance, the stain resistance, and the occurrence of a pot-like residual film are generated. The presence or absence of was evaluated. As a result, almost the same result as that of the planographic printing plate precursor provided with the image recording layer B was obtained.

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. It is a graph which shows an example of the alternating waveform current waveform figure used for the electrochemical roughening process in preparation of the support body for lithographic printing plates of this invention. It is a side view which shows an example of the radial type cell in the electrochemical roughening process using alternating current in preparation of the support body for lithographic printing plates of this invention. It is the schematic of the anodizing apparatus used for the anodizing process in preparation of the support body for lithographic printing plates of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum plate 2, 4 Roller-shaped brush 3 Polishing slurry liquid 5, 6, 7, 8 Support roller 11 Aluminum plate 12 Radial drum roller 13a, 13b Main electrode 14 Electrolytic process liquid 15 Electrolyte supply port 16 Slit 17 Electrolyte path 18 Auxiliary anodes 19a, 19b Thyristors 20 AC power supply 40 Main electrolytic tank 50 Auxiliary anode tank 410 Anodizing device 412 Power supply tank 414 Electrolytic treatment tank 416 Aluminum plate 418, 426 Electrolytic solution 420 Power supply electrode 422, 428 Roller 424 Nip roller 430 Electrolytic electrode 432 Tank wall 434 DC power supply

Claims (3)

Using an atomic force microscope, the surface area ratio and steepness obtained from three-dimensional data obtained by measuring 512 × 512 points on each of 50 μm × 50 μm and 5 μm × 5 μm of the surface are as follows: (iii) A support for a lithographic printing plate used for a lithographic printing plate precursor provided with a thermal positive type image recording layer satisfying the above.
(I) Surface area ratio ΔS ⁵⁰ is 61 to 90%
(Ii) Steepness a45 ^{50 (0.2-2)} is 10 to 50%
(Iii) Surface area ratio ΔS ^{5 (0.02-0.2)} is 20 to 80%
Here, the surface area ratio ΔS ⁵⁰ is an actual area S _x ⁵⁰ determined by an approximate three-point method from three-dimensional data obtained by measuring 512 × 512 points of 50 μm × 50 μm of the surface using an atomic force microscope, From the geometric measurement area S ₀ ⁵⁰ , the surface area ratio determined by the following formula (1):
ΔS ⁵⁰ = (S _x ⁵⁰ −S ₀ ⁵⁰ ) / S ₀ ⁵⁰ × 100 (%) (1)
The steepness a45 ^{50 (0.2-2)} is obtained by extracting components having a wavelength of 0.2 μm or more and 2 μm or less from 3D data obtained by measuring 512 × 512 points of 50 μm × 50 μm on the surface using an atomic force microscope. Is the steepness that is the area ratio of the portion with a slope of 45 ° or more in the data obtained by
The surface area ratio ΔS ^{5 (0.02-0.2)} is determined from three-dimensional data obtained by measuring 512 × 512 points on a surface of 5 μm × 5 μm using an atomic force microscope, and a component having a wavelength of 0.02 μm to 0.2 μm. It is a surface area ratio obtained by the following formula (2) from the actual area S _x ^{5 (0.02-0.2)} obtained by the approximate three-point method from the data obtained by extraction and the geometric measurement area S ₀ ⁵ .
ΔS ^{5 (0.02-0.2)} = (S _x ^{5 (0.02-0.2)} −S ₀ ⁵ ) / S ₀ ⁵ × 100 (%) (2)   The lithographic printing plate support according to claim 1, wherein the number of local deep portions having a depth of 4 µm or more present on the surface is 6 or less per 400 µm x 400 µm. A lithographic printing plate precursor comprising a thermal positive type image recording layer provided on the lithographic printing plate support according to claim 1 or 2.

Images