JP2001335998A - Aluminum supporting body and roughening method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a supporting body in which honeycomb pits are formed over the whole face and relatively low in glossiness without depending on the kinds of aluminum to be used. SOLUTION: In this aluminum supporting body for a planographic printing plate, the ratio of the number of pits with a diameter of 0.5 to <1.5 μm to be occupied to the total number of pits with a diameter of 0.1 to 10 μm formed on the surface of an aluminum plate subjected to roughening is 90 to 100%, the ratio of the number of pits with a diameter of 0.5 to <1.0 μm to be occupied is 50 to 80%, also, 85 degree glosiness is 10 to 35, and the average surface roughness is 0.2 to 0.5 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aluminum support and a method for roughening the same.

[0002]

2. Description of the Related Art An aluminum support used in a lithographic printing plate needs to be uniformly roughened in order to improve the adhesion between the support and the photosensitive layer. Examples of the method of roughening the aluminum support for a lithographic printing plate include those disclosed in JP-A-3-104694, JP-A-3-79799, and JP-A-58-207400. The characteristic values of the roughened aluminum support are disclosed in U.S. Pat. No. 5,834,129.

[0003]

However, the dissolution rate varies depending on the crystal orientation of aluminum, and differences (pit number and size) occur in the pitting reaction. Depending on the type of the support, uniform honeycomb pits could not be obtained. In addition, in a portion where the copper component is concentrated, electrochemical surface roughening was not performed, and a portion where no honeycomb pit was formed sometimes remained. Further, when a printing plate is manufactured using the support obtained by these methods, the surface of the support shines during printing, and the operator can accurately apply ink and water to the image and non-image portions of the printing plate. It was difficult to supply to.

[0004] The present invention provides a support having relatively low glossiness because honeycomb pits are formed on the entire surface regardless of the type of aluminum used, and a rough surface of an aluminum support capable of providing such a support. The purpose of the present invention is to provide a conversion method.

[0005]

SUMMARY OF THE INVENTION The present invention is as follows. <1> Diameter 0.5 with respect to the total number of pits having a diameter of 0.1 to 10 μm generated on the surface of the roughened aluminum plate
The ratio of the number of pits of not less than 1.5 μm to less than 1.5 μm is 90%
Pits having a diameter of 0.5 μm or more and less than 1.0 μm account for 50-80%, and 8%.
5 degree glossiness is 10 to 35, average surface roughness is 0.2
An aluminum support for a lithographic printing plate, characterized by having a thickness of from 0.5 to 0.5 μm. <2> The aluminum plate is sequentially subjected to (1) electrochemical surface-roughening treatment in an aqueous hydrochloric acid solution using an alternating current with an electric quantity of 1 to 300 C / dm ² , and (2) the aluminum plate in an aqueous alkali solution. Etching so as to dissolve 0.05 to 1.5 g / m ² , (3) desmutting in an acidic aqueous solution, and (4) 50 to 500 C using an alternating current in a nitric acid aqueous solution.
(5) electrochemical surface-roughening treatment with an electric quantity of / dm ²
Sulfuric acid 2 containing aluminum ions at 60-90 ° C
Dipping in an aqueous solution of 5 to 50% by weight for 1 to 60 seconds,
(6) A method for roughening the surface of an aluminum support, wherein anodizing treatment is performed so as to obtain a coating of 0.8 to 5 g / m ² . <3> (4) 50 to 50 using an alternating current in an aqueous nitric acid solution
After electrochemical surface-roughening treatment with an amount of electricity of 0 C / dm ² , (5) immersion treatment is carried out at 60 to 90 ° C. in an aqueous solution of 25 to 50% by weight of sulfuric acid containing aluminum ions for 1 to 60 seconds. <2> The method for roughening an aluminum support according to <2>, wherein the aluminum support is subjected to an etching treatment in an aqueous alkali solution. <4> (1) 1 to 30 using an alternating current in an aqueous hydrochloric acid solution.
<2> or <3>, wherein the aluminum plate is etched in an alkaline aqueous solution and desmutted in an acidic aqueous solution before the electrochemical surface-roughening treatment with an electric quantity of 0 C / dm ^2. 3. The method for roughening an aluminum support according to 1.). <5> The method for roughening an aluminum support according to any one of <2> to <4>, wherein a hydrophilic treatment is performed after the anodizing treatment. <6> (1) Using an alternating current in an aqueous hydrochloric acid solution, 1 to 30
Performing at least one of buffing and mechanical surface roughening before etching of an aluminum plate in an aqueous alkali solution before electrochemical surface roughening with an amount of electricity of 0 C / dm ^2. <4> The method for roughening an aluminum support according to <4>. <7> (4) 50 to 50 using alternating current in an aqueous nitric acid solution
After electrochemical surface-roughening treatment with an electric quantity of 0 C / dm ² , (5) before etching in an alkaline aqueous solution before desmutting in an acidic aqueous solution, 200 μm in air.
<3> The method for roughening an aluminum support according to <3>, wherein the aluminum plate is heated at a temperature of 300 to 300 ° C. <8> The method for roughening an aluminum support according to <6>, wherein the mechanical surface roughening treatment is performed by transferring the surface shape of the roll having irregularities onto an aluminum plate. <9> (1) Using an alternating current in an aqueous hydrochloric acid solution, 1 to 30
<2> to <2>, wherein pits having a diameter of more than 2 μm and a diameter of less than 10 μm are produced at 5000 to 20000 pits / mm ² by performing an electrochemical surface-roughening treatment with an electric quantity of 0 C / dm ^2. 8> The method for roughening an aluminum support according to any one of the above items.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The aluminum plate used in the present invention is selected from a pure aluminum plate, an alloy plate containing aluminum as a main component and a trace amount of a different element, and a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, nickel, manganese, copper, magnesium, chromium, zinc, bismuth, titanium, vanadium and the like. Conventionally known materials such as those described in the Aluminum Handbook 4th Edition (1990, Light Metal Association), for example, JISA 105
0 material, JIS A 3103 material, JIS A 3005
Wood, JISA 1100 wood, JIS A 3004 wood,
In addition, alloys to which 5% by weight or less of magnesium is added for the purpose of increasing the tensile strength can be used. As a method for manufacturing the aluminum plate, a continuous casting and rolling method can be used in addition to a normal DC casting method. As the continuous casting and rolling method, a twin roll method, a belt caster method, a block caster method, or the like can be used. Note that D
At least one of the intermediate annealing process and the soaking process may be omitted from the C casting method, or the intermediate annealing process may be omitted from the continuous casting method. The thickness of the aluminum plate used in the present invention is about 0.1 to 0.6 mm.

The aluminum plate is roughened by the following procedure. (1) If necessary, at least one of a buffing treatment and a mechanical roughening treatment is performed. (2) An etching treatment is performed in an alkaline aqueous solution as necessary. (3) A desmutting is performed in an acidic aqueous solution as necessary. (4) Electrochemical surface-roughening treatment in an aqueous hydrochloric acid solution using an alternating current with an electric quantity of 1 to 300 C / dm ^2. Etching so as to dissolve 0.5 g / m ² , (6) desmutting in an acidic aqueous solution, and (7) 50-500 C using an alternating current in a nitric acid aqueous solution.
(8) electrochemical surface-roughening treatment with an electric quantity of / dm ²
Heat treatment if necessary, (9) etching treatment in an alkaline aqueous solution as necessary, (10) 60 to 90 ° C.
Immersion treatment in an aqueous solution of 25 to 50% by weight of sulfuric acid containing aluminum ions for 1 to 60 seconds, (11)
Anodizing treatment is performed so as to obtain a coating of 0.8 to 5 g / m ² .

Hereinafter, each step will be described. Buffing Processing A polishing apparatus 10 as shown in FIG. 1 can be used for the buffing processing. The polishing apparatus 10 mainly includes a nonwoven fabric roller 14 disposed on one side of a thin plate-shaped metal plate 12 for a printing plate such as an aluminum plate or an aluminum zinc plate;
A pair of support rollers 16, 16 arranged on the other side to support the printing plate metal plate 12, and a slurry 1 containing an abrasive;
8 or a water supply nozzle 20 for jetting water onto the surface of the printing plate metal plate 12.

The nonwoven fabric roller 14 includes a cylindrical core member 24 fitted and fixed to a rotating shaft 22 connected to a motor (not shown), and a cylindrical nonwoven fabric 26 fitted and fixed to a peripheral surface of the core member 24. Prepare. The nonwoven fabric roller 14 can move forward and backward about 100 mm in the direction of the arrow AB, and can be pushed between the pair of support rollers 16. Various non-woven fabrics can be used as the non-woven fabric. For example, a non-woven fabric made of nylon and having a surface hardness of 40 degrees or more when formed into the non-woven fabric roller 14 is preferable.

A pair of support rollers 16 for supporting the printing plate metal plate 12 are configured by fitting a cylindrical hard rubber or a metal cylinder to the rotating shaft 28. The separation distance (L) between the pair of support rollers 16 is the same as that of the nonwoven fabric roller 1.
4 is arranged to be shorter than the diameter (D), for example, a nonwoven fabric roller 14 having a diameter of 300 mm and a diameter of 200 m.
m, the distance (L) between the pair of support rollers 16 is 25 mm at 100 mm or more.
It is preferably 0 mm or less. The pair of support rollers 16 rotate at the same speed as the traveling speed of the printing plate metal plate 12.

The water supply nozzle 20 is connected to the printing plate metal plate 12.
In the traveling direction of the nonwoven fabric roller 14, it is disposed upstream of the nonwoven fabric roller 14, and is formed in a long shape along the axial direction of the nonwoven fabric roller 14. A slurry or water containing an abrasive is supplied to the water supply nozzle 20 from a slurry supply device (not shown). The polishing apparatus 10 rotates the nonwoven fabric roller 14 while supplying slurry or water from the water supply nozzle 20 to the surface of the printing plate metal plate 12, and thereby the printing plate metal plate 1 is rotated.
2 is polished.

Known abrasives can be used,
Silica sand, quartz, aluminum hydroxide or mixtures thereof are preferred. Mechanical surface roughening treatment In the mechanical surface roughening referred to in the present invention, a rotating nylon brush roll (for example, having a bristle diameter of 0.2 to 1.61 mm) and a slurry containing an abrasive are used. It is advantageous. The slurry described above can be used as the slurry containing the abrasive. Other methods include a method of spraying a slurry liquid on the surface of a support, a method of using a wire brush, a method of transferring the surface shape of a roll having irregularities onto an aluminum plate, and JP-A-55-74898 and JP-A-61-162351. Or the method described in JP-A-63-104889 or the like can be used.

It is particularly preferable to use a method in which the surface shape of the rolling roll is transferred to an aluminum plate, since energy consumption is small and uniform unevenness can be obtained efficiently.
At this time, the average surface roughness of the aluminum plate (JIS B
0601 (measured by the 1994 version)) is from 0.3 to
0.5 μm is preferred. Chemical etching treatment in alkaline aqueous solution The concentration of the alkaline aqueous solution is preferably 1 to 30% by weight, and the aluminum alloy may contain 0 to 10% by weight of the alloy component contained in the aluminum alloy. As the alkaline aqueous solution, an aqueous solution mainly containing caustic soda is particularly preferable. The liquid temperature is preferably from room temperature to 95 ° C.,
The processing time is preferably from 1 to 120 seconds.

After the formation of fine irregularities by electrochemical surface roughening in an aqueous hydrochloric acid solution, an oxide film or the like is formed. Therefore, in order to uniformly perform the next electrochemical surface roughening, an alkali film is required. 0.01 to 3 g / m ² of an aluminum plate in an aqueous solution
It is preferable to perform a mild etching process to dissolve,
Particularly preferred is 0.05 to 1.5 g / m ² . The usable alkaline aqueous solution and the processing conditions are as described above.

After electrochemical surface roughening in an aqueous nitric acid solution, etching in an aqueous alkaline solution can be performed if necessary. In this case, the etching amount is set to 0.1.
01-5 g / m ² is preferable, and 0.05-1.5 g / m ²
Is more preferred.

After the completion of the etching process, it is preferable to carry out draining with a nip roller and washing with water to prevent the treatment liquid from being carried to the next step. Desmut treatment Generally, when chemical etching is performed using an aqueous alkali solution, smut is generated on the surface of aluminum, and in this case, phosphoric acid, nitric acid, sulfuric acid, chromic acid,
Desmutting is performed with hydrochloric acid or a mixed acid containing two or more of these acids. The concentration of the acidic aqueous solution is preferably 0.5 to 60% by weight. Further, the acidic aqueous solution contains not only aluminum but also alloy components contained in the aluminum alloy in an amount of 0 to 5 wt.
% May be dissolved. The liquid temperature is preferably from room temperature to 95 ° C., and the processing time is preferably from 1 to 120 seconds. After the end of the desmutting treatment, it is preferable to perform draining with a nip roller and washing with water by spraying so as not to bring the treatment liquid into the next step. 1 to 300 C / dm ² using an alternating current in a hydrochloric acid aqueous solution.
Electrochemical surface roughening with air volume The hydrochloric acid aqueous solution referred to in the present invention can be used for the electrochemical surface roughening treatment using ordinary direct current or alternating current, and specifically 1 to 100 g / Liter hydrochloric acid aqueous solution (solution in which 1-100 g of hydrogen chloride is dissolved in 1 liter of water) contains at least one of a nitric acid compound such as aluminum nitrate, sodium nitrate and ammonium nitrate, and a chloride such as aluminum chloride, sodium chloride and ammonium chloride.
Seeds added from 1 g / liter to saturation can be used. In particular, an aqueous solution containing 5 to 15 g / l of hydrochloric acid and an aluminum salt added so that aluminum ions are 3 to 50 g / l is preferable. In the aqueous hydrochloric acid solution, metals contained in aluminum alloys such as iron, copper, manganese, nickel, titanium, magnesium and silica may be dissolved. Further, hypochlorous acid may be added. As additives, devices, power sources, current densities, flow rates, and temperatures other than those described above, those known in the art for electrochemical surface roughening and conditions may be used. Further, as the apparatus, those described later can be used. The amount of electricity that the aluminum plate participates in the anodic reaction by electrochemical roughening in an aqueous hydrochloric acid solution (total amount of electricity when the aluminum plate is used as the anode) is 1 to 3.
It can be selected from the range of 00 C / dm ² , and is 5 to 150 C / d
m ² is preferred, and 10 to 100 C / dm ² is particularly preferred.

A sine wave, a rectangular wave, a trapezoidal wave, a triangular wave, or the like can be used as an AC power supply waveform used for electrochemical surface roughening. preferable. The rising time tp of the trapezoidal waveform is preferably 0.1 to 2 msec, and 0.3 to 1.msec.
0 msec is particularly preferred.

The current density is 10 to 2 as the peak value of the current waveform.
00 A / dm ² is preferred, and 25 to 100 A / dm ² is particularly preferred. The duty ratio of the power supply waveform (anode reaction time ta / 1 time T of one cycle) is preferably from 0.25 to 0.75, particularly preferably from 0.45 to 0.55. The frequency is 0.
1 to 250 Hz is preferred, and 50 to 120 Hz is particularly preferred.

It is preferable that pits are uniformly formed on the entire surface of the aluminum support after the surface roughening treatment in an aqueous hydrochloric acid solution, that is, there is no unetched portion. Specifically, the diameter is larger than 2 μm and 10 μm.
5000 pits smaller than m / mm ² or more 200
00 / mm ² or less, and 0.1 to 0.8 in diameter
It is particularly preferable that pits of μm are densely formed in order to accurately supply water and ink during printing. When an unetched portion exists, it is preferable that the unetched etched portion is uniformly dispersed. Electrochemical surface roughening in nitric acid aqueous solution As the nitric acid aqueous solution referred to in the present invention, those used for electrochemical surface roughening treatment using ordinary direct current or alternating current can be used. A solution obtained by adding at least one kind of a nitric acid compound such as aluminum nitrate, sodium nitrate, and ammonium nitrate and a chloride such as aluminum chloride, sodium chloride, and ammonium chloride to a 400 g / liter nitric acid aqueous solution from 1 g / liter to saturation is used. be able to. Particularly preferred is an aqueous solution in which aluminum chloride and aluminum nitrate are added so that aluminum ions become 3 to 50 g / liter in an aqueous solution of 5 to 20 g / liter of nitric acid. In the nitric acid aqueous solution, metals contained in aluminum alloys such as iron, copper, manganese, nickel, titanium, magnesium, and silica may be dissolved. The temperature is preferably from 10 to 95 ° C, more preferably from 40 to 80 ° C.

A sine wave, a rectangular wave, a trapezoidal wave, a triangular wave, or the like can be used as the AC power supply waveform used for the electrochemical surface roughening. preferable. The rising time tp of the trapezoidal waveform is preferably 0.1 to 2 msec, and 0.3 to 2 msec.
1.0 msec is particularly preferred.

The current density is 10 to 2 as the peak value of the current waveform.
00 A / dm ² is preferred, and 25 to 100 A / dm ² is particularly preferred.

The amount of electricity to be added to the aluminum plate (total amount of electricity when the aluminum plate is used as an anode) is 50 to 500
Preferably C / dm ^2, in particular, 60~300C / dm ² is preferred. The duty ratio of the power supply waveform is 0.25 to 0.75
Is preferable, and 0.45 to 0.55 is particularly preferable. The frequency is preferably from 0.1 to 250 Hz, particularly preferably from 50 to 60 Hz. Electrochemical surface roughening apparatus using alternating current As the electrolytic cell used for electrochemical surface roughening using alternating current in the present invention, a known electrolytic cell such as a vertical type, a flat type, or a radial type can be used. However, a radial electrolytic cell (FIG. 3) as described in JP-A-5-195300 is particularly preferred. In this electrolytic cell, an aluminum plate W is wound around a radial drum roller 12 arranged in a main electrolytic cell 10 and connected to an AC power supply 11 in a conveying process.
3b is subjected to electrolytic treatment. The electrolytic solution 15 is supplied from the electrolytic solution supply port 14 through the slit 16 to the radial drum roller 1.
It is supplied to the electrolyte passage 17 between the main electrode 2 and the main electrodes 13a and 13b. The aluminum plate W treated in the main electrolytic cell 10 is then subjected to electrolytic treatment in the auxiliary anode cell 20. An auxiliary anode 21 is disposed in the auxiliary anode tank 20 so as to face the aluminum plate W, and the electrolytic solution 15 is supplied so as to flow in a space between the auxiliary anode 21 and the aluminum plate W. The auxiliary anode is ferrite, iridium oxide, platinum, platinum is titanium,
It can be selected from known oxygen generating electrodes such as clad or plated valve metals such as niobium and zirconium. The cathode is carbon, platinum, titanium, niobium,
The electrode can be selected from zirconium, stainless steel, and an electrode used for a cathode for a fuel cell.

The supply direction of the electrolytic solution passing through the electrolytic cell may be parallel or counter to the progress of the aluminum web. The relative flow rate between the aluminum plate and the electrolyte is 10 to 10
00 cm / sec is preferable. One or more AC power supplies can be connected to one electrolytic cell. Two or more electrolytic cells can be used, and the electrolytic conditions in each cell may be the same or different.

After the completion of the electrolytic treatment, it is preferable to carry out draining with a nip roller and washing with water to prevent the treatment liquid from being carried to the next step. It is preferable to heat the aluminum plate in air in order to boehmite components mainly composed of aluminum hydroxide after electrochemical surface roughening in a heat-treated nitric acid aqueous solution.
The heating temperature is preferably from 200 to 300 ° C, and from 230 to 27 ° C.
0 ° C. is more preferred. Heating time is from 0.01 second to 120
Minutes are preferred. Sulfuric acid 2 containing aluminum ions at 60-90 ° C
Immersion treatment in an aqueous solution of 5 to 50% by weight for 1 to 60 seconds This step is a desmut treatment when the step (9) is performed. In this step, an aqueous solution of 25 to 50% by weight of sulfuric acid containing aluminum ions is used, and the liquid temperature is 60 to
The temperature is 90 ° C., and the processing time is 1 to 60 seconds. Liquid temperature is 7
The temperature is preferably 0 to 90 ° C., and the processing time is preferably 1 to 10 seconds. In addition, 0.1 to 5 g / liter of aluminum ions may be dissolved as aluminum sulfate in the aqueous sulfuric acid solution. By performing this treatment, the aluminum substrate surface is sufficiently washed, and an aluminum support for a lithographic printing plate, which has less defects and is less likely to be stained in a film formed by an anodic oxidation treatment performed later, can be obtained.

The roughened aluminum support is anodized to increase water retention, adhesion to the photosensitive layer, and mechanical strength of the surface of the non-image area. Anodizing treatment Anodizing treatment can be performed according to a known method. Any electrolyte can be used as long as it forms a porous oxide film.
Generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, amide sulfonic acid, or a mixture of two or more of these, or an aqueous solution or non-aqueous solution containing Al ³⁺ ions therein is used as the electrolytic solution. The concentration of the electrolyte is appropriately determined depending on the type of the electrolyte. Since the processing conditions of anodization vary depending on the electrolyte used, they cannot be specified unconditionally,
Generally, the concentration of the electrolyte is 1 to 80 wt%, and the liquid temperature is 5 to
70 ° C., current density 0.5 to 60 A / dm ² , voltage 1
~ 100V, electrolysis time is 10 ~ 300 seconds. The sulfuric acid method usually uses a direct current, but it is also possible to use an alternating current. The amount of the anodized film is preferably in the range of 1 to 10 g / m ² , more preferably 0.3 to 6 g / m ² , and 0.8 to 10 g / m ^2.
5 g / m ² is more preferred. If the amount is less than 1 g / m ² , the printing durability is insufficient, and the non-image portion of the lithographic printing plate is easily scratched, so that ink is attached to the scratched, so-called scratch stain is liable to occur. If it is more than 10 g / m ² , it is uneconomical. The anodic oxidation treatment may be performed not only on the front surface but also on the back surface, and in that case, scratches on the back surface can be suppressed. When the front and back surfaces are anodized, it is preferable to process the front and back surfaces at the same time because the process can be simplified. The amount of the anodic oxide film on the back surface is desirably 0.1 to ² g / m ² .

By the above roughening treatment, an aluminum support having honeycomb pits uniformly formed on the entire surface is obtained. Specifically, the diameter formed on the surface is 0.1 to 10 μm
The ratio of the number of pits having a diameter of 0.5 μm or more and less than 1.5 μm to the total number of pits is 90 to 100% (preferably 95%).
100%), and the ratio of the number of pits having a diameter of 0.5 μm or more and less than 1 μm is 50-80% (preferably 60-80%).
%). Diameter 0.1
If the ratio of the number of pits having a diameter of 0.5 μm or more and less than 1.5 μm with respect to the total number of pits of 10 μm to 10 μm is less than 90%, the stain prevention property during printing deteriorates. If the ratio of the number of pits having a diameter of 0.5 μm or more and less than 1 μm is less than 50%, the stain resistance at the time of printing becomes poor, and if it exceeds 80%, the printing durability tends to decrease. The 85-degree glossiness of the aluminum support is 10 to 35, preferably 15 to 25, and the average surface roughness is 0.2 to 0.5 μm (preferably 0.3 to 0.45 μm). When the glossiness at 85 degrees is less than 10, the color of the support becomes black, and the plate testability deteriorates.
If it exceeds 300, fountain solution during printing becomes difficult to see. When the average surface roughness is less than 0.2 μm, the printing durability is poor, and
If it exceeds μm, the scumming prevention performance deteriorates. The SEM photograph of the aluminum support was taken, the area of each pit was determined, and the square root of the value obtained by dividing the determined area by the pi was defined as the pit diameter. 85 degree glossiness is JIS Z87
41 (1983 version), and the average surface roughness is measured according to JIS B0601 (1994 version).

The method for roughening the aluminum support may be applied not only to one side but also to both sides of the support. This surface roughening method can be applied not only to an aluminum support for a lithographic printing plate but also to any aluminum plate.

The anodized aluminum support can be further subjected to a sealing treatment or a hydrophilic treatment as required. Sealing treatment Sealing treatment is performed by immersing an aluminum plate in a hot water or a hot aqueous solution containing an inorganic salt or an organic salt, a steam bath, or the like. The hydrophilic treatment hydrophilization treatment, U.S. Patent 2,714,066
No. 3,181,461, 3,280,734 and 3,902,734, a method using an alkali metal silicate (for example, an aqueous solution of sodium silicate). is there. In this method,
The support is immersed in an aqueous solution of sodium silicate or subjected to electrolytic treatment. Also, a method using potassium fluorozirconate disclosed in JP-B-36-22063, and U.S. Patent Nos. 3,276,868 and 4,1.
The method using polyvinyl phosphonic acid as disclosed in the specifications of JP-A-53,461 and JP-A-4,689,272 can also be used as the hydrophilization treatment. After the above-described lithographic printing plate treatment, a lithographic printing plate having excellent printing performance can be obtained by forming a photosensitive layer on a support according to a conventional method.
In addition, an intermediate layer can be provided on the support as needed. In addition, on the photosensitive layer, a mat is used to improve the adhesion to the squirrel film at the time of vacuum printing, shorten the time of evacuation at the time of close contact exposure using a vacuum printing frame, and prevent burning blur. A layer may be provided. Furthermore, when a photosensitive layer is formed only on one side of the support, a back coat layer is provided on the back surface to prevent the dissolution of aluminum during development or to prevent the photosensitive layer from being damaged when printing plates are stacked. You may. Either the back coat layer or the photosensitive layer may be coated on the support first, or both may be coated simultaneously.
Further, an undercoat layer may be provided on the support in order to improve the adhesion between the support and the photosensitive layer. Undercoat Layer An organic compound can be used for the undercoat layer. Examples of organic compounds include, for example, U.S. Pat. No. 3,860,4.
No. 26, a water-soluble metal salt (for example,
Hydrophilic cellulose (eg, carboxymethylcellulose) containing zinc acetate and the like; dextrin; gum arabic; phosphonic acids having an amino group such as 2-aminoethylphosphonic acid; phenylphosphonic acid optionally having a substituent; naphthyl Organic phosphonic acids such as phosphonic acid, alkyl phosphonic acid, glycerophosphonic acid, methylene diphosphonic acid and ethylene diphosphonic acid, and polyvinyl phosphonic acid described in U.S. Pat. No. 4,135,461; Organic phosphoric acids such as phenylphosphoric acid, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid; organic phosphines such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent Acids: glycine, β-alanine, JP-A-60 Amino acids such as amino acids and their salts (eg, alkali metal salts such as sodium salts and potassium salts, ammonium salts, hydrochlorides, oxalates, acetates, phosphates, etc.) disclosed in Japanese Patent No. 149491; hydrochloric acid of triethanolamine Examples thereof include a hydrochloride of an amine having a hydroxyl group such as a salt; and amines having a hydroxyl group and salts thereof (hydrochloride, oxalate, phosphate, etc.) disclosed in JP-A-60-232998. These may be used alone or in combination of two or more.

Also, a compound having an amino group and a phosphonic acid group or a salt thereof disclosed in JP-A-63-165183, a compound having a phosphonic acid group disclosed in JP-A-4-282637, JP 59
A polymer compound containing a monomer unit having a sulfonic acid group described in JP-A-10-16551;
No. 149491, NH ₄ group, CO
A compound having an OΗ group or an SO ₃ H group can be used as the undercoat layer. Further, a polymer compound containing an acid group and an onium group disclosed in EP09040954A2 or a sol-gel solution disclosed in JP-A-9-236911 can be applied as an undercoat layer. Further, when the support is treated with an alkali metal silicic acid, a polymer containing an acid group and an onium group can be used as an undercoat layer after the treatment.

A yellow dye can be added to the undercoat layer to improve the tone reproducibility of the photosensitive lithographic printing plate.

The undercoat layer can be formed by applying an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixture thereof in water or a solution obtained by dissolving the above organic compound on an aluminum plate, followed by drying. An aluminum plate is immersed in a solution in which the above organic compound is dissolved in water, or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof, and the above organic compound is adsorbed. There is a method of drying. In the former method, a solution of the above organic compound having a concentration of 0.005 to 10% by weight can be applied by various methods. For example, bar coater application,
Any method such as spin coating, spray coating, and curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight.
The immersion temperature is 20 to 90 ° C., preferably 25 to 5 ° C.
0 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The pH of the solution can be adjusted with a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, or an acidic substance such as hydrochloric acid or phosphoric acid.

The coating amount of the organic undercoat layer after drying is 2 to 20.
0 mg / m ² is suitable, preferably 5 to 100 mg.
/ M ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. In addition, 200 mg / m ²
The same is true for larger values. Backcoat layer An organic polymer compound is used as a main component in the backcoat layer. Examples of the organic polymer compound include a saturated copolymerized polyester resin having a glass transition point of 20 ° C. or higher, a phenoxy resin, a polyvinyl acetal resin, and a vinylidene chloride copolymerized resin. The saturated copolymerized polyester resin is composed of a dicarboxylic acid unit and a diol unit. Examples of the dicarboxylic acid unit include aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, tetrabromophthalic acid, and tetrachlorophthalic acid; adipic acid, azelaic acid, succinic acid, oxalic acid, suberic acid, sebacic acid, and malonic acid And saturated aliphatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid. Examples of the diol unit include ethylene glycol, propylene glycol, triethylene glycol, butanediol, pentanediol, heptanediol, octanediol, nonanediol, and decanediol.

The back coat layer further comprises a dye or pigment for coloring, a silane coupling agent for improving adhesion to an aluminum support, a diazo resin composed of a diazonium salt, an organic phosphonic acid, an organic phosphoric acid and a cation. A wax, a higher fatty acid, a higher fatty acid amide, a silicone compound composed of dimethylsiloxane, a modified dimethylsiloxane, a polyethylene powder, etc., which are usually used as a slipping agent, such as a hydrophilic polymer, are appropriately added.

The thickness of the back coat layer is basically sufficient if it does not damage the photosensitive layer even if there is no slip sheet.
The range of 01 to 8 μm is preferred. When the thickness is less than 0.01 μm, it is not possible to prevent the photosensitive layer from being scratched when the lithographic printing plates are handled in an overlapping manner. When the thickness exceeds 8 μm, the back coat layer swells due to chemicals used around the printing plate during printing, the thickness fluctuates, the printing pressure changes, and the printing characteristics may deteriorate.

Various methods can be applied to coat the back coat layer on the back surface of the aluminum support. For example, a solution or dispersion obtained by dissolving or emulsifying and dispersing the organic polymer compound in an appropriate solvent is applied and dried, and a back coat layer previously formed into a film is aluminum-supported with an adhesive or heat. And a method in which a molten film is formed with a melt extruder and then bonded to a support. In these, form a solution,
The method of coating and drying is most preferable for securing the above-mentioned coating amount. The solvent used here is described in
Organic solvents as described in JP-A-251739 are used alone or in combination. Photosensitive layer The photosensitive layer contains an infrared absorbing agent, a compound capable of generating an acid by heat, and a compound capable of being crosslinked by an acid; A compound containing a compound having a radical; a compound that generates radicals by irradiation with laser light; a binder containing an alkali-soluble binder; a layer containing a polyfunctional monomer or prepolymer; and an oxygen barrier layer; A layer composed of two layers: a development nucleus layer and a silver halide emulsion layer; a layer composed of a polyfunctional monomer and a polyfunctional binder, a layer composed of silver halide and a reducing agent, and an oxygen barrier layer; One having two layers of a layer containing novolak resin and naphthoquinonediazide and a layer containing silver halide; one containing an organic photoconductor; And the laser beam absorbing layer, those having at least one of the oleophilic layer and a hydrophilic, compound which generates an acid by irradiating an energy, a polymer compound having a functional group which generates sulfonic acid or carboxylic acid by acid,
Some include a compound that gives energy to an acid generator by absorbing visible light. Of these, o-
Positive type containing quinonediazide compound as main component, photosensitive diazo compound, photopolymerizable composition containing unsaturated double bond-containing monomer as main component, photocrosslinkable composition containing cinnamic acid and dimethylmaleimide group, etc. Is preferably used. In addition, Japanese Patent Publication No. 37-17
Nos. 172 and 38-6961, JP-A-56-1072
No. 46, No. 60-254142, JP-B-59-362
No. 59, 59-25217, and JP-A-56-1461.
No. 45, No. 62-194257, No. 57-14765
No. 6, No. 58-100862, No. 57-161863
And the electrophotographic photosensitive layers described in JP-A Nos. 60-107042 can also be suitably used.

Among these, the o-quinonediazide compound used as a positive photosensitive composition is disclosed in
An ester of 1,2-diazonaphthoquinonesulfonic acid and a pyrogallol-acetone resin described in -28403 is preferred. Other suitable o-quinonediazide compounds include, for example, U.S. Pat. No. 3,046,
No. 120 and 3,188,210, esters of 1,2-diazonaphthoquinone-5-sulfonic acid with a phenol-formaldehyde resin,
Esters of 1,2-diazonaphthoquinone-1-sulfonic acid and phenol-formaldehyde resin described in JP-A-2-96163, JP-A-2-96165 and JP-A-2-96661; Showa 4
Nos. 7-5303, 43-63802, 48-63
No. 803, No. 48-96575, No. 49-38701
No. 48-13854, JP-B-37-18015
Nos. 41-11222, 45-9610, and 4
9-17481, U.S. Pat. No. 2,797,213
No. 3,453,400, No. 3,544,32
No. 3, No. 3,573,917, No. 3,674, 4
No. 95, 3,785, 825 and British Patent Nos. 1, 2
No. 27,602, No. 1,251,345, No. 1,
267,005, 1,329,888, 1st
Examples thereof include o-naphthoquinonediazide compounds described in each specification such as No. 330,932 and German Patent No. 854,890.

Particularly preferred o-quinonediazide compounds are o-naphthoquinonediazide compounds obtained by reacting a polyhydroxy compound having a molecular weight of 1,000 or less with 1,2-diazonaphthoquinonesulfonic acid. Specific examples of such compounds are described in JP-A-51-139402.
No. 58-150948, No. 58-203434
No., 59-165053, 60-12445
No. 60-134235, No. 60-16343
No. 61-118744, No. 62-10645,
No. 62-10646, No. 62-153950, No. 6
2-178562, 64-76047, U.S. Pat. Nos. 3,102,809 and 3,126,281,
No. 3,130,047, No. 3,148,983
No. 3,184,310, No. 3,188,21
No. 0, No. 4,639,406 and the like, and those described in each gazette or specification. When synthesizing these o-naphthoquinonediazide compounds,
1,2 relative to the hydroxyl group of the polyhydroxy compound
-Diazonaphthoquinone sulfonic acid chloride 0.2 to
Preferably, 1.2 equivalents are reacted, and 0.3 to 1.0
More preferably, the reaction is carried out in an equivalent amount. Examples of the 1,2-diazonaphthoquinonesulfonic acid chloride include 1,2-diazonaphthoquinone-5-sulfonic acid chloride, and 1,1-diazonaphthoquinone-5-sulfonic acid chloride.
2-diazonaphthoquinone-4-sulfonic acid chloride can be used. Further, the obtained o-naphthoquinonediazide compound is a mixture of various compounds having different positions and introduced amounts of 1,2-diazonaphthoquinonesulfonic acid ester groups. The proportion of the resulting compound in the mixture (the content of the completely esterified compound) is preferably at least 5 mol%, more preferably 20 to 99 mol%.

The proportion of the o-quinonediazide compound in the positive photosensitive composition is suitably from 10 to 50% by weight, and more preferably from 15 to 40% by weight.

As the photosensitive diazo compound used in the negative photosensitive layer, an aromatic diazonium salt and an organic condensing agent having a reactive carbonyl group, particularly an aldehyde such as formaldehyde and acetaldehyde or an acetal are used in an acidic medium. Condensed diazo resins are preferably used.
The most typical one is a condensate of p-diazodiphenylamine and formaldehyde. The synthesis of these diazo resins is described, for example, in US Pat. No. 2,678,49.
No. 8, No. 3,050,502, No. 3,311,6
No. 05 and 3,277,074. As the photosensitive diazo compound, a co-condensed diazo compound of an aromatic diazonium salt described in JP-B-49-48001 and a substituted aromatic compound not containing a diazonium group is preferably used, and among them, a carboxyl group or a hydroxyl group is preferred. A co-condensed diazo compound with an aromatic compound substituted with such an alkali-soluble group is preferred. Further, photosensitive diazo compounds obtained by condensing an aromatic diazonium salt with a reactive carbonyl compound having an alkali-soluble group described in JP-A-4-18559, JP-A-4-190361 and JP-A-4-172353 are also preferably used. . As a counter anion of these diazonium salts, there is a diazo resin using an inorganic anion such as a mineral acid such as hydrochloric acid, hydrobromic acid, sulfuric acid and phosphoric acid or a double salt with zinc chloride. Solvent-soluble diazo resins are particularly preferred. Such a preferred diazo resin is disclosed in
No. 1167 and U.S. Pat. No. 3,300,309.

Further, JP-A-54-98613 and JP-A-56-98613 describe the same.
A diazo resin having a counter anion of a halogenated Lewis acid such as tetrafluoroboric acid or hexafluorophosphoric acid and a perhalic acid such as perchloric acid or periodic acid as described in JP-A-121031 is preferably used. Can be
JP-A-58-209733 and JP-A-62-1775.
A diazo resin having a long chain alkyl group-containing sulfonic acid as a counter anion described in JP-A Nos. 31 and 63-262643 is also preferably used.

The photosensitive diazo compound is contained in the photosensitive layer in an amount of 5 to 50.
%, Preferably in the range of 8 to 20% by weight.

Examples of the photopolymerizable composition containing a monomer having an unsaturated double bond as a main component used in a negative photosensitive layer include, for example, US Pat. Nos. 2,760,863 and 3,060, No. 023 and JP-A-59-538.
No. 36, a composition comprising an addition polymerizable unsaturated compound having two or more terminal ethylene groups and a photopolymerization initiator can be used. Examples of the photocrosslinkable composition containing a dimethylmaleimide group include the compositions described in JP-A-52-988, EP0410654, JP-A-3-2888853 and JP-A-4-25845. be able to.

For the positive and negative photosensitive layers, a resin soluble in alkaline water is preferably used as a binder. Novolak resins include, for example, phenol-formaldehyde resins, o-, m-, and p-cresol-formaldehyde resins, m / p-mixed cresol-formaldehyde resins, and phenols. -Cresol (o-,
m-, p-, m / p- and o / m-mixtures) -formaldehyde resin. Also, phenol-modified xylene resin, polyhydroxystyrene, polyhalogenated hydroxystyrene,
An acrylic resin containing a phenolic hydroxyl group as disclosed in JP-A-34711 can also be used. As other suitable binders, the following (1) to
Copolymers having a molecular weight of usually 10,000 to 200,000 using the monomer shown in (13) as a constituent unit can be exemplified. (1) Acrylamides, methacrylamides, acrylates, methacrylates, and hydroxystyrenes having an aromatic hydroxyl group, for example, N-
(4-hydroxyphenyl) acrylamide, N- (4
-Hydroxyphenyl) methacrylamide, o-, m-
And p-hydroxystyrene, o-, m- and p-
Hydroxyphenyl acrylate or methacrylate (2) Acrylic esters and methacrylic esters having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate (3) acrylic acid, methacrylic acid, maleic anhydride, methacrylate Unsaturated carboxylic acids such as acids (4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate (Substituted) acrylates such as 2-chloroethyl acrylate, 4-hydroxybutyl acrylate, glycidyl acrylate, and N-dimethylaminoethyl acrylate; (5) methyl methacrylate; Ethyl acrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, 4-hydroxybutyl methacrylate (Substituted) methacrylates such as glycidyl methacrylate and N-dimethylaminoethyl methacrylate (6) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N- Hexylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide,
N-cyclohexylmethacrylamide, N-hydroxyethylacrylamide, N-hydroxyethylmethacrylamide, N-phenylacrylamide, N-phenylmethacrylamide, N-benzylacrylamide, N-
Benzyl methacrylamide, N-nitrophenyl acrylamide, N-nitrophenyl methacrylamide, N-
Acrylamide or methacrylamide such as ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide (7) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, etc. (8) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, and vinyl benzoate (9) Styrenes such as styrene, methyl styrene, and chloromethyl styrene (10) Methyl vinyl ketone and ethyl vinyl ketone , Vinyl ketones such as propyl vinyl ketone and phenyl vinyl ketone (11) ethylene, propylene, isobutylene, butadiene Olefins such as isoprene (12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc. (13) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonyl) Acrylamides such as phenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- [1- (3-aminosulfonyl) naphthyl] acrylamide, and N- (2-aminosulfonylethyl) acrylamide;
(O-aminosulfonylphenyl) methacrylamide,
N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) methacrylamide, N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacryl Methacrylamides such as amides, o-
Aminosulfonylphenyl acrylate, m-aminosulfonylphenyl acrylate, p-aminosulfonylphenyl acrylate, 1- (3-aminosulfonylphenylnaphthyl) acrylate, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl Unsaturated sulfonamides such as methacrylates such as methacrylate and 1- (3-aminosulfonylphenylnaphthyl) methacrylate Further, in addition to the above-mentioned photosensitive diazo compounds, monomers shown in the following (14) and (15) A polymer compound obtained by copolymerizing as a structural unit can also be used as a binder. (14) maleimide, N-acryloylacrylamide, N-acetylacrylamide, N-propionylacrylamide, N- (p-chlorobenzoyl) acrylamide, N-acetylacrylamide, N-acryloylmethacrylamide, N-acetylmethacrylamide,
Unsaturated imides such as N-propionyl methacrylamide and N- (p-chlorobenzoyl) methacrylamide (15) N- [2- (acryloyloxy) -ethyl]
Unsaturated monomers having a crosslinkable group in the side chain such as -2,3-dimethylmaleimide, N- [6- (methacryloyloxy) -hexyl] -2,3-dimethylmaleimide, and vinyl cinnamate (1) to ( Another monomer may be copolymerized with the monomer of 13). Further, a copolymer obtained by copolymerization of the above monomers, for example, modified with glycidyl acrylate, glycidyl methacrylate, or the like can also be used as the binder. As the monomer of the copolymer, it is preferable to use the unsaturated carboxylic acids listed in (3), and the acid value of the copolymer is preferably from 0 to 10 meq / g, more preferably from 0.2 to 5.0 meq. / G. The preferred molecular weight of the copolymer is 10,000 to 100,000. Further, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, and an epoxy resin may be added to the copolymer as needed. Further, in the case of a positive photosensitive layer, as described in U.S. Pat. No. 4,123,279, there are 3 to 8 carbon atoms such as t-butylphenol-formaldehyde resin and octylphenol-formaldehyde resin. It is preferable to use a condensate of phenol and formaldehyde having an alkyl group as a substituent in view of improving the oil sensitivity of an image. Such alkali-soluble resins can be used alone or in combination of two or more.

The alkali-soluble resin is used in an amount of 80% by weight or less of the positive photosensitive layer (solid content of the entire photosensitive composition), and is used in the negative photosensitive layer (solid content of the entire photosensitive composition). ) Is usually added in the range of 40 to 95% by weight.

It is preferable to add a cyclic acid anhydride, a phenol, an organic acid or a higher alcohol to the positive or negative photosensitive layer in order to enhance the sensitivity and developability.

As the cyclic acid anhydride, US Pat.
Phthalic anhydride described in US Pat. No. 15,128;
Tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy- △ 4-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride,
Chloromaleic anhydride, α-phenylmaleic anhydride,
Succinic anhydride, pyromellitic anhydride and the like can be used.

As phenols, bisphenol A, p-nitrophenol, p-ethoxyphenol,
2,4,4'-trihydroxybenzophenone, 2,
3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ', 4 "-trihydroxytriphenylmethane, 4,4', 3", 4 "-tetrahydroxy-3,5,3 ', 5' -Tetramethyltriphenylmethane and the like.

As the organic acids, JP-A-60-8894
2, sulfonic acids, sulfinic acids, alkyl sulfates described in JP-A-2-96755 and the like;
Examples include phosphonic acids, phosphoric esters, and carboxylic acids. Specific examples include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, and phenyl phosphate. , Diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 1,4-
Cyclohexene-2,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid and the like.

The proportion of the above-mentioned cyclic acid anhydrides, phenols and organic acids in the photosensitive composition is from 0.05 to 0.05.
It is preferably 15% by weight, more preferably 0.1 to 5% by weight.

To the photosensitive composition, cyclic acid anhydrides, phenols, organic acids and higher alcohols can be added in order to enhance developability.

A positive-working or negative-working photosensitive composition used in the present invention contains a printing-out agent for obtaining a visible image immediately after exposure, and a dye such as a dye or pigment as an image coloring agent. be able to. Representative examples of the printing-out agent include a combination of a compound that releases an acid upon exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, o-naphthoquinonediazide described in JP-A-50-36209 and JP-A-53-8128 is disclosed.
Combinations of 4-sulfonic acid halides and salt-forming organic dyes and JP-A-53-36223 and JP-A-54-74728.
No. 60-3626, No. 61-143748, No. 61-151644 and No. 63-58440 in combination with the trihalomethyl compounds and salt-forming organic dyes. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear print-out images.

As the colorant for the image, other dyes can be used in addition to the salt-forming organic dyes described above. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. Those that change color by reacting with free radicals or acids are preferably used. For example, Victoria Pure Blue BOH (Hodogaya Chemical), Oil Yellow # 101, Oil Yellow # 1
03, Oil Pink # 312, Oil Red, Oil Green BG, Oil Blue BOS, Oil Blue # 60
3. Oil black BY, oil black BS, oil black T-505 (or more, Orient Chemical Co., Ltd.)
), Patent pure blue (manufactured by Sumitomo Sangoku Chemical Co., Ltd.), crystal violet (CI42555), methyl violet (CI42535), ethyl violet, rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5201)
5) triphenylmethanes represented by brilliant blue, methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4-p-diethylaminophenyliminaphthoquinone, cyano-p-diethylaminophenylacetanilide,
Examples of diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based and anthraquinone-based dyes changing from colored to colorless or different colored tones.

On the other hand, examples of the color changing agent that changes from colorless to colored include leuco dyes and, for example, triphenylamine, diphenylamine, o-chloroaniline, 1,2,2,
3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p'-bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p,
p ', p "-tris-dimethylaminotriphenylmethane, p, p'-bis-dimethylaminodiphenylmethylimine, p, p', p" -triamino-o-methyltriphenylmethane, p, p'-bis -Dimethylaminodiphenyl-4-anilinonaphthylmethane, p, p ', p "
Primary or secondary arylamine dyes represented by -triaminotriphenylmethane. Particularly preferred are triphenylmethane-based and diphenylmethane-based dyes, more preferred are triphenylmethane-based dyes, and particularly Victoria Pure Blue BOH. Dyes described in JP-A-62-293247 are also particularly preferred.

The above dye is usually used in the photosensitive composition in an amount of about 0.
The content is 5 to 10% by weight, more preferably about 1 to 5% by weight.

In the positive-type and negative-type photosensitive compositions, a surfactant for improving the coated surface quality, for example, Japanese Patent Application Laid-Open No. Sho 62
A fluorine-based surfactant as described in JP-A-170950 can be added. A preferable addition amount is 0.001 to 10% by weight of the whole photosensitive composition,
More preferably, it is 0.005 to 0.5% by weight.

In addition, in the positive photosensitive composition, the stability of processing under development conditions (so-called development latitude)
The nonionic surfactants described in JP-A-62-251740 and JP-A-59-251740 are used to improve the
An amphoteric surfactant as described in JP-A No. 121044 and JP-A-4-13149 can be added. Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride,
Examples thereof include polyoxyethylene sorbitan monooleate and polyoxyethylene nonylphenyl ether.
Specific examples of the amphoteric surfactant include alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl-N, N- Betaine (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.) and alkyl imidazoline (for example, Levon 15, trade name, manufactured by Sanyo Chemical Co., Ltd.) and the like can be mentioned. The ratio of the nonionic surfactant and the amphoteric surfactant in the photosensitive composition is 0.05 to 15%.
% By weight, more preferably 0.1 to 5% by weight.

In the negative photosensitive composition, a sensitizing agent (for example, Japanese Patent Application Laid-Open No.
No. 527, a half-esterified product of a styrene-maleic anhydride copolymer with an alcohol, a novolak resin, a 50% fatty acid ester of p-hydroxystyrene, etc.). Further, a plasticizer for imparting flexibility and abrasion resistance of the coating film is added. Examples of the plasticizer include, for example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate,
Examples include tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers and polymers of acrylic acid or methacrylic acid, among which tricresyl phosphate is particularly preferred.
In the negative photosensitive composition, in order to improve the stability over time, for example, phosphoric acid, phosphorous acid, citric acid, oxalic acid, dipicolinic acid, benzenesulfonic acid, naphthalenesulfonic acid, sulfosalicylic acid, 4-Methoxy-2-hydroxybenzophenone-5-sulfonic acid, tartaric acid and the like are added.

The photosensitive composition is formed by applying a solution or dispersion obtained by dissolving or dispersing the above components in a solvent onto an aluminum plate as a support. Examples of the solvent used here include organic solvents as described in JP-A-62-251739. This solvent may be used alone or as a mixture. The solid content concentration of the photosensitive composition in the solvent is 2 to 50% by weight. The amount of the photosensitive composition layer (photosensitive layer) applied on the support varies depending on the application, but is generally preferably 0.3 to 4.0 g / m ^{2 in} terms of the weight after drying. . As the coating amount decreases, the exposure amount for obtaining an image may be small,
The film strength decreases. As the amount of application increases, the amount of exposure is required but the photosensitive film becomes stronger. For example, when used as a printing plate, a printing plate with a high printable number (high printing durability) can be obtained. Matt layer The method for forming the mat layer is described in JP-A-50-12580.
No. 5, JP-B-57-6582 and JP-A-61-28986. A method of providing a mat layer as described in JP-B-57-65886 and JP-B-62-62337. And the like. The average diameter of the matting agent contained in the mat layer used in the present invention is preferably 100 μm or less, and when the lithographic printing plates are stored in an overlapping manner when the average diameter is larger than this, the contact area between the photosensitive layer and the back coat layer is reduced. Increased, slipperiness decreased,
The surface of both the photosensitive layer and the back coat layer is easily scratched. The average thickness of the mat layer is preferably 1 to 10 μm,
More preferably, it is 2 to 8 μm. Average thickness is 10μm
If it is thicker, it is difficult to form a fine line, the highlight dots are reduced, and it is not preferable in tone reproduction. If the average thickness is less than 1 μm, the vacuum adhesion will be insufficient and burning will occur. The coating amount of the mat layer is preferably from 5 to 200 mg / m ^2, more preferably from 20~150mg / m ^2. 200m coating amount
If it is larger than g / m ² , the contact area between the photosensitive layer and the back coat layer increases, causing abrasion, and if it is smaller than 5 mg / m ² , the vacuum adhesion becomes insufficient. The lithographic printing plate thus obtained is exposed through a transparent original image with actinic rays using a carbon arc lamp, a mercury lamp, a metal halide lamp, a xenon lamp, a tungsten lamp or the like as a light source, and then developed. As a developer and a replenisher for the lithographic printing plate, conventionally known alkaline aqueous solutions can be used. For example, sodium silicate, potassium, tribasic sodium, potassium, ammonium, dibasic sodium, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, potassium Ammonium, sodium borate, potassium, ammonium,
And inorganic alkali agents such as sodium hydroxide, ammonium hydroxide, potassium hydroxide and lithium hydroxide. Also,
Monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine And organic alkali agents such as ethylenediamine, pyridine and the like.

Various developing and replenishing solutions for positive and negative type lithographic printing plates may be used as necessary for the purpose of accelerating or suppressing the developing property, dispersing developing scum, and enhancing the ink affinity of the printing plate image area. Surfactants (anionic, cationic, nonionic and amphoteric surfactants) and organic solvents can be added.

Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and glycerin fatty acid partial esters. , Sorbitan fatty acid partial esters,
Ventaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters , Polyoxyethylenated castor oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides,
Nonionic surfactants such as N, N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, and trialkylamine oxides, fatty acid salts, abietic acid salts,
Hydroxyalkyl sulfonates, alkyl sulfonates, dialkyl sulfosuccinates, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy polyoxyethylene propyl sulfonates, polyoxy Ethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfate esters of fatty acid alkyl esters, alkyl sulfates Salts, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates, Oxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, partially saponified styrene / maleic anhydride copolymers, Partially saponified olefin / maleic anhydride copolymers, anionic surfactants such as naphthalenestyrene formate condensates, alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, polyethylenepolyamine derivatives, etc. And amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. Among the surfactants mentioned above, the term "polyoxyethylene" can be replaced with polyoxyalkylene such as polyoxymethylene, polyoxypropylene and polyoxybutylene, and those surfactants are also suitably used.

Further preferred surfactants are fluorine-based surfactants containing a perfluoroalkyl group in the molecule. Examples of such fluorine-based surfactants include anionic surfactants such as perfluoroalkyl carboxylate, perfluoroalkyl sulfonate, and perfluoroalkyl phosphate, amphoteric surfactants such as perfluoroalkyl betaine, and perfluoroalkyl Cationic surfactants such as trimethylammonium salts, perfluoroalkylamine oxides, perfluoroalkylethylene oxide adducts, oligomers containing perfluoroalkyl and hydrophilic groups, oligomers containing perfluoroalkyl and lipophilic groups, perfluoroalkyl groups, Nonionic surfactants such as oligomers containing hydrophilic groups and lipophilic groups, and urethanes containing perfluoroalkyl groups and lipophilic groups are included. The above-mentioned surfactants can be used alone or in combination of two or more, and 0.001 to 10% by weight, more preferably 0.01 to 10% by weight in the developer.
It is added in the range of 5% by weight.

As an organic solvent, the solubility in water is about 1
0% by weight or less is preferable, and the solubility in water is 5%.
More preferably, the content is not more than weight%. For example, 1-phenylethanol, 2-phenylethanol, 3-phenyl-1-propanol, 4-phenyl-1-butanol,
4-phenyl-2-butanol, 2-phenyl-1-butanol, 2-phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m
-Methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 4-methylcyclohexanol, N-phenylethanolamine, N-phenyldiethanolamine and the like. it can. The content of the organic solvent is 0.1 to 5% by weight based on the total weight of the developer or replenisher. The amount used is closely related to the amount used of the surfactant, and it is preferable to increase the amount of the surfactant as the amount of the organic solvent increases. This is because if the amount of the surfactant is small and the amount of the organic solvent is large, the organic solvent is not completely dissolved in the developer or the replenisher, and good developability cannot be secured.

A reducing agent can be further added to the developer and replenisher for the lithographic printing plate. This is to prevent the printing plate from being stained, and is particularly effective for developing a negative type lithographic printing plate containing a photosensitive diazonium salt compound. Preferred organic reducing agents include thiosalicylic acid, hydroquinone, methol, methoxyquinone, resorcinol,
Examples include phenol compounds such as methylresorcin, and amine compounds such as phenylenediamine and phenylhydrazine. Preferred inorganic reducing agents include sodium, potassium and ammonium salts of inorganic acids such as sulfurous acid, bisulfite, phosphorous acid, bisulfite, diphosphite, thiosulfate and dithionite. And the like. Among these reducing agents, sulfites are particularly excellent in the stain prevention effect. These reducing agents are preferably used in an amount of 0.05 to 5% by weight based on the developer or the replenisher.
It is contained in the amount of.

An organic carboxylic acid can be further added to the developer and the replenisher. Preferred organic carboxylic acids are aliphatic carboxylic acids having 6 to 20 carbon atoms and aromatic carboxylic acids. Specific examples of the aliphatic carboxylic acid include caproic acid, enantiic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred are saturated fatty acids having 8 to 12 carbon atoms. . Unsaturated fatty acids having a double bond in the carbon chain and those having a branched carbon chain can also be used. Aromatic carboxylic acid is a compound in which a carboxyl group is substituted on a benzene ring, a naphthalene ring, an anthracene ring, or the like,
Specifically, o-chlorobenzoic acid, p-chlorobenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, o-aminobenzoic acid, p-aminobenzoic acid, 2,4
-Dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, 1-hydroxy-2-naphthoic acid, 3 -Hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid,
There are 1-naphthoic acid and 2-naphthoic acid, and hydroxynaphthoic acid is particularly effective. The aliphatic and aromatic carboxylic acids are sodium salts to enhance water solubility,
It is preferably used as a potassium or ammonium salt. The content of the organic carboxylic acid is not particularly limited,
If the amount is less than 0.1% by weight with respect to the developer or replenisher, the effect is not sufficient. If the amount is more than 10% by weight, the effect cannot be further improved. May interfere. Therefore, the preferred addition amount is 0.1 to 10% by weight, more preferably 0.5 to 4% by weight, based on the developer or replenisher.

If necessary, conventionally known compounds such as an antifoaming agent, a water softener and an organic boron compound described in Japanese Patent Publication No. 1-57895 can be added to the developing solution and the replenishing solution. Examples of the water softener include polyphosphoric acid, its sodium salt, potassium salt and ammonium salt, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitriletriacetic acid, and 1,2-diaminocyclohexanetetraacetic acid. Aminopolycarboxylic acids such as acetic acid and 1,3-diamino-2-propanoltetraacetic acid, their sodium, potassium and ammonium salts, aminotri (methylenephosphonate), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepentane (Methylene phosphonic acid), triethylenetetramine hexa (methylene phosphonic acid), hydroxyethylethylenediamine tri (methylene phosphonic acid), 1-hydro Shietan -
Mention may be made of 1,1-diphosphonic acids, their sodium, potassium and ammonium salts.

The amount of the water softener varies depending on the chelating power, the hardness of the hard water used and the amount of the hard water. -5% by weight, more preferably 0.1-4% by weight. If the amount is less than 0.01% by weight, the intended purpose is not sufficiently achieved.

The remaining component of the developer and replenisher is water, but may further contain various additives known in the art, if necessary. For the developer and the replenisher, it is advantageous from the viewpoint of transportation to prepare a concentrated solution having a smaller water content than at the time of use, and to dilute it with water before use. In this case, the degree of concentration is suitably such that each component does not cause separation or precipitation.

The lithographic printing plate thus developed is post-treated with washing water, a rinsing solution containing a surfactant and / or a desensitizing solution containing gum arabic and a starch derivative.

This post-processing can be carried out by an automatic developing machine in the same manner as the development processing. The automatic developing machine consists of transport means for transporting the lithographic printing plate, a developing tank, a post-processing tank and a spray device. For spraying the lithographic printing plate from a spray nozzle onto the lithographic printing plate, and a device for guiding and immersing the lithographic printing plate in a processing liquid tank filled with a processing liquid by a guide roll or the like. When a lithographic printing plate is processed by an automatic developing machine, a replenisher is replenished to each processing liquid according to a processing amount, an operating time, and the like.

[0071]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. (Examples 1 to 16, Comparative Examples 1 to 3) JIS A 1050 rolled aluminum plate (aluminum A, thickness 0.24 mm) manufactured by DC casting method, manufactured by DC casting method without soaking heat treatment and intermediate annealing treatment JIS A 105
0 aluminum rolled plate (aluminum B, thickness 0.24m
m), JIS A 1050 manufactured by continuous casting method
Rolled aluminum plate (aluminum C, thickness 0.24mm),
Alternatively, in the final cold rolling step in the DC casting method, irregularities are formed by a rolling roll having irregularities to obtain an average surface roughness of 0.1.
Polishing, mechanical surface roughening, etching in an alkaline aqueous solution (1), desmutting (1), hydrochloric acid on a JIS A 1050 rolled aluminum plate (aluminum D, thickness 0.3 mm) having a thickness of 4 μm Surface roughening treatment in aqueous solution, etching treatment in alkaline aqueous solution (2),
Table of desmutting treatment (2), electrochemical surface roughening treatment in nitric acid aqueous solution, etching treatment in alkaline aqueous solution (3), immersion treatment in sulfuric acid aqueous solution, anodic oxidation treatment, and hydrophilic treatment 1 was performed. After each treatment, the aluminum plate was washed with water by spraying and drained with a nip roller. Each treatment was performed as follows. Using a 400 mm diameter roll containing an alumina abrasive having an average particle size of 10 μm in a non-woven fabric made of buffing-treated nylon,
Circumferential speed 900m / min, Oscillate 200 times / min
Then, the aluminum plate was polished. While supplying a suspension of quartz sand and water of a mechanical surface roughening specific gravity 1.12 on the surface of the aluminum plate as an abrasive slurry, it was on an aluminum plate by rotating a roller-like nylon brush roughening. The material of the nylon brush was 6.10 nylon, the bristle length was 50 mm, and the bristle diameter was 0.48 mm. The nylon brush was planted so as to be dense by making holes in a stainless steel cylinder having a diameter of 300 mm. Three rotating brushes were used. Two support rollers at the bottom of the brush (diameter 2
00 mm) was 300 mm. Etching treatment in alkaline aqueous solution (1) NaOH 27% by weight, and aluminum ion 6.5
The aluminum plate was immersed in an aqueous solution containing 70% by weight and containing 70% by weight and etched. Table 1 shows the dissolution amount of the aluminum plate. Desmut treatment (1) Hydrochloric acid 1% by weight and aluminum ion 0.5% by weight
The aluminum plate was immersed in an aqueous solution containing 35 ° C. at 35 ° C. for desmutting. The immersion time is shown in Table 1. Electrochemical surface roughening treatment in hydrochloric acid aqueous solution AC voltage in FIG. 2 (ta is an anode reaction time, tc is a cathode reaction time, tp is a time from when the current value reaches 0 to a peak, a is an anode cycle The aluminum plate was continuously subjected to electrochemical surface roughening treatment using the current at the peak on the cathode side, Ic is the current at the peak on the cathode cycle side) and one of the tanks in FIG. The electrolytic solution at this time was a 1% by weight aqueous solution of hydrochloric acid (containing 0.5% by weight of aluminum ions), and the temperature of the solution was 35 ° C. In the AC power supply waveform, the time tp until the current value reaches a peak from zero is 0.3 ms.
c, a trapezoid having a duty ratio of 0.5 and a frequency of 60 Hz, a carbon electrode as a counter electrode, and a ferrite as an auxiliary anode. The current density is 5 at the peak value of the current.
Table 1 shows 0 A / dm ² and the amount of electricity (total amount of electricity when the aluminum plate was the anode). 5% of the current flowing from the power supply was diverted to the auxiliary anode. The surface of each of the aluminum plates of Examples 1 to 3 after roughening in an aqueous hydrochloric acid solution was observed by taking an SEM photograph at a magnification of 750 times.
The number of pits larger than μm and smaller than 10 μm is 17000 / mm ² , 10000 / mm ² , 800
It was 0 / mm ² . Etching Treatment in Alkaline Aqueous Solution (2) The aluminum plate was immersed in a 45 ° C. aqueous solution containing 26% by weight of NaOH and 6.5% by weight of aluminum ions to perform etching treatment. Table 1 shows the dissolution amount of the aluminum plate. Desmut treatment (2) 1% by weight of nitric acid at 35 ° C (including 0.5% by weight of aluminum ion and 0.007% by weight of ammonium ion)
An aluminum plate was immersed in the aqueous solution for 3 seconds to perform a desmutting treatment. Electrochemical surface roughening treatment in an aqueous nitric acid solution An aluminum plate was continuously subjected to electrochemical surface roughening treatment using the AC voltage shown in FIG. 2 and the two tanks shown in FIG. The electrolytic solution at this time was a 1% by weight aqueous nitric acid solution (containing 0.5% by weight of aluminum ions and 0.007% by weight of ammonium ions). In the AC power supply waveform, the time tp until the current value reaches a peak from zero is 0.8 msec, du
The ty was a trapezoid having a ratio of 0.5 and a frequency of 60 Hz. A carbon electrode was used for the counter electrode, and ferrite was used for the auxiliary anode. The current density is 50 A /
dm ² . 5 of the current flowing from the power supply is
%. Table 1 shows the temperature of the electrolytic solution and the amount of electricity (total amount of electricity when the aluminum plate is an anode). Etching Treatment in Alkaline Aqueous Solution (3) The aluminum plate was immersed in a 45 ° C. aqueous solution containing 26% by weight of NaOH and 6.5% by weight of aluminum ions to perform etching treatment. Table 1 shows the dissolution amount of the aluminum plate. Immersion treatment in sulfuric acid aqueous solution The aluminum plate was immersed in a sulfuric acid aqueous solution. Table 1 shows the sulfuric acid concentration, liquid temperature, and immersion time. Anodizing treatment Anodizing treatment was performed on an aluminum plate at a current density of 2 A / dm ² using a DC voltage in an aqueous solution containing 10% by weight of sulfuric acid (containing 0.5% by weight of aluminum ions) at a temperature of 50 ° C. Was. Table 1 shows the amount of the anodic oxide film. The hydrophilized aluminum plate was immersed in a 2.5% by weight aqueous solution of No. 3 sodium silicate at 70 ° C. for 5 seconds. Then, it was washed with water and dried.

Among the aluminum supports subjected to the above-described treatment, the aluminum support of Example 5 had a surface of 37%.
A 50-fold SEM photograph was taken to examine the diameter of the generated honeycomb pits and the ratio thereof.
0.5 μm or more for all honeycomb pits
60% of honeycomb pits less than μm, diameter 0.5μ
90% of the pits are not less than m and less than 1.5 μm;
It was confirmed that honeycomb pits were uniformly formed on the entire surface of the support. Similarly, when the diameter and the ratio of the honeycomb pits formed on the aluminum plate of Comparative Example 1 were determined, 40% of the pits had a diameter of 0.5 μm or more and less than 1 μm, and 70% had a diameter of 0.5 μm or more and less than 1.5 μm. %Met. The average surface roughness (JIS B 0601 “1994 edition”) of the aluminum support of Example 2 was 0.3.
The average surface roughness of the aluminum support of Comparative Example 1 was 0.33 μm. Further, 85 degree glossiness (JIS) of the aluminum supports of Example 2 and Comparative Example 1
Z8741 (1983 edition))
It was 0.

The average surface roughness of the support of Example 13 after mechanical roughening was 0.45 μm.

Further, 85 of the supports of Examples 15 and 16 were used.
The glossiness at 25 ° C. was 25, and it was easy to supply the dampening solution accurately during printing.

Examples 1 to 12, 14, 16 and Comparative Examples 1 to
Example 3 of JP-A-6-135175 on the support of No. 3
A lithographic printing plate precursor was prepared by applying an undercoating solution and a photosensitive solution. In addition, the supports of Examples 13 and 15 were disclosed in
A lithographic printing plate precursor was prepared by applying the photosensitive solution of Example 1 of JP-A-4694. <Evaluation> The lithographic printing plate precursor formed as described above was exposed and developed to obtain a printing plate. The surface quality (streak) of this printing plate and the ease of supplying dampening water on a printing press were evaluated as follows. Surface quality A: No streak (streak) is observed.

B: A slight streak is observed.

C: Streak is clearly observed,
Practical level. Ease of supplying dampening water on printing press A: The area where the support is exposed does not shine, and the dampening water can be supplied accurately and easily to this area.

B: The area where the support was exposed glows slightly, but there is no problem in accurately supplying dampening water to this area.

C: The area where the support was exposed glows considerably,
Considerable care is required to supply the dampening solution accurately to this area.

Table 1 shows the results.

[0081]

[Table 1]

Example 17 Using aluminum B, air heated to 250 ° C. after electrochemical surface-roughening treatment in an aqueous nitric acid solution and before etching treatment (3) in an aqueous alkaline solution The aluminum plate was subjected to a surface roughening treatment in the same manner as in Example 13 except that the aluminum plate was subjected to a heat treatment for 90 minutes. When the surface quality of this aluminum plate was evaluated in the same manner as described above, it was A. (Example 18) An aluminum plate was roughened in the same manner as in Example 17 except that the heat treatment was not performed. When the surface quality of this aluminum plate was evaluated in the same manner as described above, it was B. (Example 19) An aluminum plate was roughened in the same manner as in Example 5 except that aluminum D was used. When the ease of supplying dampening water to the aluminum plate on a printing machine was evaluated in the same manner as described above, it was A, which was superior to Example 5.

[0083]

According to the present invention, regardless of the type of aluminum used, honeycomb pits can be formed on the entire surface and a support having relatively low gloss can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an apparatus used for a buff polishing process.

FIG. 2 is a waveform chart showing an example of a trapezoidal alternating current power supply waveform preferably used for electrochemical graining of the present invention.

FIG. 3 is a schematic diagram showing an example of an electrolysis device used for electrochemical graining of the present invention.

[Explanation of symbols]

 Reference Signs List 10 Main electrolytic cell 11 AC power supply 12 Radial drum roller 13a, 13b Main electrode 14 Electrolyte supply port 15 Electrolyte 20 Auxiliary anode tank 21 Auxiliary anode W Aluminum plate

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C25D 11/16 301 C25D 11/16 301 11/18 11/18 A C25F 7/00 C25F 7/00 L (72) Invention Person Akio Uesugi 4000F, Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term (reference) 2F114 AA04 AA11 AA14 AA27 DA04 DA10 EA02 EA09 FA14 GA03 GA04 GA07 GA09 4K057 WA05 WB05 WC03 WC10 WE22 WK01

Claims (9)

[Claims] 1. The proportion of the number of pits having a diameter of 0.5 μm to less than 1.5 μm with respect to the total number of pits having a diameter of 0.1 to 10 μm formed on the surface of a roughened aluminum plate is 90 to 100%. , 0.5μm or more and 1.0μ in diameter
The proportion of the number of pits less than m is 50 to 80%,
An aluminum support for a lithographic printing plate, characterized by having an 85 degree glossiness of 10 to 35 and an average surface roughness of 0.2 to 0.5 µm. 2. An aluminum plate is sequentially subjected to (1) electrochemical surface-roughening treatment in an aqueous hydrochloric acid solution using an alternating current with an electric quantity of 1 to 300 C / dm ² , and (2) an aluminum plate in an aqueous alkaline solution. The plate is etched to dissolve 0.05 to 1.5 g / m ² , (3) desmutted in an acidic aqueous solution, and (4) 50 to 5 g in a nitric acid aqueous solution using alternating current.
Electrochemical surface roughening treatment with an amount of electricity of 00 C / dm ² ,
(5) Dipping in an aqueous solution of 25 to 50% by weight of sulfuric acid containing aluminum ions at 60 to 90 ° C. for 1 to 60 seconds so that (6) a film of 0.8 to 5 g / m ² is obtained. A method for roughening an aluminum support, which comprises performing an anodizing treatment. (4) In an aqueous nitric acid solution, an alternating current is applied.
After electrochemical surface-roughening treatment with an amount of electricity of up to 500 C / dm ² , (5) immersion treatment in an aqueous solution of aluminum sulfate-containing sulfuric acid 25 to 50% by weight for 1 to 60 seconds at 60 to 90 ° C. 3. The method according to claim 2, wherein the etching is performed in an aqueous alkali solution before the etching. 4. Use of an alternating current in an aqueous hydrochloric acid solution to
Before processing the electrochemical surface roughening in an electrical quantity of ~300C / dm ^2, the aluminum plate was etched in an aqueous alkali solution, to claim 2 or 3, characterized in that desmutting treatment in an acidic aqueous solution The method for roughening an aluminum support according to the above. 5. The method for roughening an aluminum support according to claim 2, wherein a hydrophilic treatment is performed after the anodic oxidation treatment. 6. The method according to claim 1, wherein:
At least one of buffing and mechanical surface roughening is performed before etching the aluminum plate in an alkaline aqueous solution before electrochemical surface roughening with an amount of electricity of up to 300 C / dm ^2. The method for roughening an aluminum support according to claim 4, wherein: (4) 50% by using an alternating current in an aqueous nitric acid solution.
After electrochemical surface-roughening treatment with an amount of electricity of about 500 C / dm ² , (5) before etching in an alkaline aqueous solution before desmutting in an acidic aqueous solution, ² minutes in air.
The method for roughening an aluminum support according to claim 3, wherein the aluminum plate is heated at 00 to 300 ° C. 8. The surface roughening of an aluminum support according to claim 6, wherein the mechanical surface roughening treatment is performed by transferring the surface shape of the roll having irregularities to an aluminum plate. Method. 9. The method according to claim 1, wherein:
By performing an electrochemical surface-roughening treatment with an electric quantity of up to 300 C / dm ² , the diameter is larger than 2 μm and the diameter is 10 μm.
Roughening method of an aluminum support according to any one of claims 2 to 8, characterized in that 5,000 to 20,000 pieces / mm ² to produce a smaller pits.