JPH11115339A - Manufacture of support for lithographic printing plate, support for lithographic printing plate, and photo-sensitive lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the surface smooth and easy to slip in despite of having a roughtened surface of a proper degree, and also, prevent sponge residue from arising by a method wherein in the middle of a process, a process wherein a printing plate is pressed from both surfaces by a pair of rollers is inserted at least at one location. SOLUTION: In the middle of a process wherein the surface of an aluminum plate is mechanically ground and/or electrochemically ground, and then, chemically ground, and an anode oxidation treatment is performed, a process wherein both surfaces are pressed by a pair of rollers is inserted at least at one location. That is, for the pair of the rollers, a roll which touches the grinding surface is made a metal roll or a resin roll of which the hardness based on a JISK6301 spring type hardness test is 90 deg. or higher. Also, the rear surface roll is a rubber roll of which the hardness is 50-90 deg., and a pressure pressed by the pair of the rollers from both surfaces is made 0.8 kg/cm or higher per roll width. In addition, the diameter of the pair of the rollers is made 100-300 mm, and the treatment is performed by changing the peripheral velocity of the rollers to be within ±10% based on the carrying speed of the aluminum plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a lithographic printing plate support, a support obtained by the method, and a photosensitive lithographic printing plate using the support. More specifically, the present invention relates to a method for producing a lithographic printing plate support made of an aluminum plate, a support obtained by the method, and a photosensitive lithographic printing plate using the support.

[0002]

2. Description of the Related Art Conventionally, aluminum or aluminum alloy has been widely used as a support for a lithographic printing plate.
In order to improve the adhesiveness with the photosensitive layer provided on the aluminum support, and to improve the water retention of the non-image portion of a lithographic printing plate manufactured from the aluminum support, the aluminum support Has an average roughness R
The surface is roughened to a thickness of about 0.3 to 1.0 μm. Examples of the roughening (graining) method include mechanical polishing (roughening) methods such as ball polishing, brush polishing, buff polishing, and blast polishing, and electrochemical roughening method called electrolytic polishing. Alternatively, there are a chemical polishing (roughening) method, a method combining these polishing methods, and the like.

[0003] Among these polishing (graining) methods, the surface roughening method by brush polishing or the electrochemical surface roughening method is excellent in terms of excellent performance as a lithographic printing plate support and excellent in mass production. And a roughening method combining these two methods is advantageous. However, each of these methods has the following problems.

In the brush polishing, the bristles of a brush such as a nylon brush and an abrasive are used to form a portion where the surface is complicatedly scraped, or a burr-like sharp projection such that aluminum is raised without being cut. Or a locally deep and sharp recess may be formed. As a result, the surface of the aluminum plate is easily damaged when handling the aluminum plate, and when the photosensitive solution is applied, the photosensitive solution repels due to sharp projections, or application unevenness occurs. Furthermore, in a photosensitive printing plate (PS plate) coated with a photosensitive liquid,
When the PS plates rub against each other, there are problems such as scratches on the projections and peeling of the photosensitive film.

On the other hand, also in the electrochemical surface roughening (electropolishing) method, chemical polishing (etching) using a strong alkaline agent or the like is necessary in order to remove smut generated at the time of electrolytic polishing. Partially sharp points are formed on the aluminum surface by etching, so when the aluminum surface is scratched, or when this plate surface is wiped with a sponge, the sponge gets stuck on the sharp point and cannot be moved smoothly. And the sponge residue remains on the printing plate.

[0006] In addition, these problems cannot be solved by a roughening method combining mechanical polishing such as the above-mentioned brush polishing, electrolytic polishing and chemical polishing. The lithographic printing plate support is subjected to anodizing treatment, hydrophilization treatment and the like after the above-mentioned surface roughening treatment, and is manufactured by incorporating a water washing step each time. And
Between each treatment, a pair of upper and lower rollers are usually used, and the rollers used are soft rubber rolls or soft sponge rolls so as not to damage the polished surface. It is hung lightly enough to drain the liquid.

[0007] The roll used in such a case is, for example, 1200 to 1500 mm wide, has a hardness of about 70 degrees, and is applied under its own weight or with a weight (50 kg or less) that does not allow the roll to be applied. Therefore, it is not possible to flatten the sharp protrusions on the grain surface formed by the polishing process. Also, during the processing of aluminum, in order to change the angle, using a conversion roll, the total pressure may be pulled with a tension of several hundred kg, but in this case, the contact area between the roll and the aluminum plate is large, It is not possible to fix sharp protrusions on the aluminum surface.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a smooth and slippery surface despite having a moderately roughened surface. An object of the present invention is to provide a method for producing a lithographic printing plate support which does not generate any sponge scum and an aluminum support thus obtained. Still another object is to provide a photosensitive lithographic printing plate which is free from unevenness or cissing of a photosensitive solution and which is excellent in printing durability and resistance to contamination when used as a printing plate.

[0009]

The present inventors have found that when manufacturing a lithographic printing plate support, the present invention has a strong resistance to a transport roll or a partition roll used during the various processing steps after polishing as described above. By applying pressure, further reducing the roll diameter and the like to a certain value or less, and reducing the contact area between the roll and the aluminum plate, it was found that the sharp projections on the aluminum surface could be rounded, and the present invention was reached. Things.

[0010] The present invention provides a method for producing a lithographic printing support in which the surface of an aluminum plate is subjected to mechanical polishing and / or electrochemical polishing, followed by chemical polishing and anodic oxidation treatment, and the support thus obtained. A method for producing a support for a lithographic printing plate, characterized by including a step of pressing from both sides with a pair of rollers, at least one place in the middle of the above steps, and the support thus obtained. In the pair of rollers, the roll coming to the polishing surface is a metal roll or JIS K
A resin roll having a hardness of 90 degrees or more based on a 6301 spring-type hardness test, a back roll being a rubber roll having a hardness of 50 to 90 degrees, and a pressure applied from both sides by the pair of rollers is 0.8 kg / cm per roll width. That is, the diameter of the pair of rollers is 100 to 300 mm, and the peripheral speed of the rollers is ±
A method for producing a lithographic printing plate support which is processed by changing the content to 10% or less, and further provides a photosensitive lithographic printing plate obtained by coating a photosensitive composition on the support thus obtained. is there.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail in order. The aluminum plate used in the present invention is a plate-shaped body such as pure aluminum containing aluminum as a main component or an aluminum alloy containing a trace amount of foreign atoms. Such heteroatoms include silicon, iron, copper, manganese,
There are magnesium, nickel, zinc, titanium and the like. The composition of the aluminum plate applied to the present invention is not specified, and a conventionally known and publicly available material can be used. The thickness of the aluminum plate used in the present invention is preferably about 0.1 to 0.4 mm.

The aluminum plate is subjected to a degreasing treatment with, for example, a surfactant or an aqueous alkali solution in order to remove oil adhering to the surface during rolling. Then, after washing with water,
A roughening treatment is performed, and as a roughening method, there are a method of mechanically roughening the surface, a method of electrochemically roughening the surface, and a method of combining both. As a method for mechanically roughening the surface, a known method called brush polishing, ball polishing, blast polishing, or the like can be used. In particular, the brush polishing is advantageous in mass production. is there. As a method of electrochemically roughening the surface (electropolishing), there is a method of performing alternating or direct current in a hydrochloric acid or nitric acid electrolytic solution.

The aluminum plate thus roughened is washed with water and subjected to chemical polishing (etching) such as alkali etching. Examples of the alkali agent used for alkali etching include sodium hydroxide, potassium hydroxide, sodium tertiary phosphate, potassium tertiary phosphate, sodium aluminate, sodium carbonate, sodium metasilicate, sodium orthosilicate, sodium gluconate and the like. These can be used alone or as a mixture of two or more.

The concentration of the alkaline etching solution is 1 to 60.
% By weight, and at a liquid temperature of 30 to 100 ° C., 2% by weight.
Treated 60 seconds, 0.5~13g / m ² is etched. As a method of performing etching, there is a method of immersing an aluminum plate in an etching solution bath, a method of applying an etching solution with a spray or a nozzle, and the like. After the above alkali etching, washing with water, desmutting with nitric acid, phosphoric acid, sulfuric acid or a mixed acid containing two or more of these acids as needed, or smut removal by simple washing with water or high pressure washing in some cases I do.

When the brush polishing and the electrolytic polishing are used in combination, a step of performing an alkaline etching after the brush polishing, and then performing an electrolytic polishing and an alkali etching is performed. As a matter of course, the treatment is always performed by inserting a water washing step between each treatment.

Before and after each of the above treatments and washing with water, the liquid is always separated by a pair of rollers or the like for drainage.
The present invention is a method of smoothing the surface by installing a pressure roll at this partition roller or at least at one or more locations thereafter and crushing protrusions formed on the surface.

The pressure applied to the pressure roll of the present invention is 0.8 kg / cm or more per roll width, and the upper limit varies depending on the roll used, but the roll receiving shaft may break or the roll may not roll. However, the pressure at which aluminum is rolled is not preferable. If the pressing pressure is less than 0.8 kg / cm per roll width, it is not preferable because the protrusions formed on the surface cannot be crushed. The pressure is
Added by air cylinder or hydraulic pressure etc.
When the roll's own weight is sufficiently heavy, its own weight pressure may be used.

The upper roll in contact with the aluminum surface is preferably a metal roll or a resin roll having a hardness of 90 degrees or more. The hardness in the specification of the present application refers to a tester A according to a test method described in JIS K 6301 spring hardness test.
It is a numerical value obtained using the shape. As the metal roll, a roll made of chrome plating of iron or an iron alloy can be generally used. Examples of the resin that can be processed into a resin roll having a hardness of 90 degrees or more include polyacetal resin, Teflon resin, phenol resin, polycarbonate resin, high-molecular polyethylene resin, urethane resin, nylon resin, ebonite, and the like. 100 degrees.

As the lower roll in contact with the back surface of aluminum, a rubber roll having a hardness of 90 degrees or less is desirable. More preferably, it is 80 to 50 degrees. When the hardness exceeds 90 degrees, both upper and lower sides become hard, so the liquid drainage becomes worse, and when the hardness is less than 50 degrees, even if pressure is applied from the top, it is sunk into the lower roll to flatten the surface It is not preferable because it becomes impossible. Materials for the rubber roll for the lower roll include styrene rubber, nitrile rubber, neoprene rubber,
Silicone rubber, butyl rubber, natural rubber and the like can be mentioned.

The diameter of the pressure roll is preferably 300 mm or less, more preferably 250 to 100 mm. If the diameter exceeds 300 mm, the contact area with the aluminum plate increases, and even if pressure is applied, small projections on the surface cannot be crushed. Is weakened, and the protrusions cannot be crushed, and the running out of liquid becomes worse.

If the peripheral speed of the pressure roll is changed within ± 10% of the conveying speed of the aluminum plate to be processed, a slight displacement occurs between the pressure roll and the aluminum plate, and The protrusions can be crushed more clearly. If the speed change exceeds ± 10%, on the contrary, the deviation width becomes large and the surface is flawed, which is not preferable. A more preferred range is within ± 5%.

The aluminum plate treated as described above is subjected to anodizing for the purpose of improving the abrasion resistance of the surface, the water retention during printing and the printing durability. As the electrolyte used at this time, sulfuric acid, phosphoric acid, oxalic acid, chromic acid or a mixed acid thereof is generally used.

The anodic oxidation treatment conditions vary depending on the electrolyte used and thus cannot be set. However, in general, the concentration of the electrolyte is 1 to 50% by weight, the liquid temperature is 5 to 45 ° C., and the current density is 1%.
~40A / dm ^2, it is preferable if the voltage 5~50V and processing time of 5 seconds to 5 minutes range. The amount of the anodized film is suitably 0.5 g / m ² or more, but more preferably in the range of 1.0~4.0g / m ^2. When the anodic oxide film is less than 0.5 g / m ² , the surface is apt to be scratched, and at the time of printing, the ink adheres to the scratched portion, and is likely to be stained. Conversely, if the thickness of the anodic oxide film exceeds 4.0 g / m ² , the developing speed becomes slow and sensitivity is lowered, which is not preferable.

The aluminum plate which has been anodized and washed as described above may be subjected to a boiling water treatment, a steam treatment, a silicate treatment, a phosphate treatment or a hydrophilic treatment for hydrophilization or deactivation as required. Dipping treatment in an aqueous solution containing a molecular compound can be performed. The photosensitive plate can be obtained by providing a photosensitive composition on the thus obtained aluminum plate according to a conventional method.

The photosensitive composition applied here is not particularly limited, and generally known photosensitive compositions can be applied.
For example, a positive type having an o-quinonediazide compound as a main component, a negative type having a diazo resin as a main component, a photopolymerizable compound having an unsaturated double bond-containing monomer as a main component, cinnamic acid or dimethylmaleimide A photo-crosslinkable compound containing a group, or a negative or positive type using a heat mode writing type compound as a photosensitive material is used. JP-A-55-161250, JP-A-4-10
No. 0052 and the like, and a photosensitive layer using a silver complex salt diffusion transfer method provided with a physical development nucleus layer and a silver halide emulsion layer can also be used.

The above photosensitive composition is usually applied as a solution of water, an organic solvent or a mixture thereof on the support according to the present invention and dried to prepare a photosensitive lithographic printing plate. When the coating amount of the photosensitive composition applied on the support of the invention is 1 to 5 g / m ² , all the coating solutions are
It is applied uniformly and neatly.

[0027]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition,
The hardness described in the examples is a value obtained by a spring type hardness test method described in JIS K 6301 using an A-type testing machine. Regarding the surface roughness, the average roughness Ra indicates a normal center line average roughness, and the maximum peak height Rp means a distance between the center line of the roughness curve (cross-sectional curve) and the highest peak. Therefore, the maximum peak height Rp is different from _Rmax , which is the distance between the highest peak and the deepest valley of the roughness curve.

Example 1 and Comparative Example 1 An aluminum plate having a thickness of 0.24 mm and a width of 1000 mm was thoroughly degreased and washed with water, and then its surface was polished with a nylon brush and an aqueous suspension of permiston, and the surface thereof was polished and washed with water. did. Next, the substrate was immersed in 15% by weight sodium hydroxide at 80 ° C. for 10 seconds to perform alkali etching.
Acid washing was performed for 10 seconds at 70% by weight of 0% by weight nitric acid, followed by water washing. The width of the top and bottom is 1
Nitrile rubber having a diameter of 200 mm, a roll diameter of 120 mm, its own weight of 45 kg, and a hardness of 65 degrees was used, and the applied pressure was 0.4 kg / cm per width of its own weight. Then, as an upper roll, width 1200mm, roll diameter 180mm,
A chrome-plated metal roll was used for an iron roll having its own weight of 120 kg, and a natural rubber roll having a hardness of 70 degrees and the same width and diameter as the upper roll was used as a lower roll, and a pressure of 250 kg was applied by an air cylinder to a total weight. The pressure at this time was slightly over 2 kg / cm per roll width. Also, the peripheral speed of the upper and lower rolls at this time is more
Rotated 5% slower. The support thus treated is referred to as Example 1 (substrate I).

After passing through the draining roll, the support produced by passing the pressure roll without applying the pressure roll is referred to as Comparative Example 1 (substrate II). Then, (Substrate I), (Substrate I)
II) is anodized in a 15% by weight aqueous sulfuric acid solution,
After washing with water, it was dried. The thickness of the anodic oxide film at this time is 2.0 g
/ M ² . The surface roughness of (substrate I) and (substrate II) at this time was measured, and the values of the average roughness Ra and the maximum peak height Rp are shown in Table 1. Table 1 shows how the surface was observed at a magnification of 3000 with an electron microscope (SEM). From Table 1, the fact that the Rp value of the substrate I is low indicates that there are few sharply protruding portions.

The thus prepared (substrate I) and (substrate II) were coated with the photosensitive solution (1) having the following composition so that the coating weight after drying was 1.8 g / m ² to form a photosensitive layer. Provided. Photosensitive solution (1) Esterified product of naphthoquinone-1,2-diazido-5-sulfonyl chloride and 2,3,4-trihydroxybenzophenone 2.5 g m-cresol-formaldehyde novolak resin 6.0 g naphthoquinone-1,2- Diazido-4-sulfonyl chloride 0.1 g Oil Blue 613 (manufactured by Orient Chemical Industries) 0.2 g Methyl cellosolve 50 g Propylene glycol monomethyl ether 50 g At this time, the coating conditions of (substrate I) and (substrate II) with the photosensitive solution are shown in Table 1. Shown in

[0031]

[Table 1]

A positive original film having halftone dots and fine lines is adhered to the photosensitive lithographic printing plate obtained from (Substrate I) and (Substrate II), and a 3 kW metal halide lamp is used as a light source, and irradiation is performed from a distance of 1 m for 40 seconds. Exposure was performed. The exposed photosensitive lithographic printing plate is 10 times as large as a commercially available developer (Sylvan Positive Developer No. 4, a developer consisting of potassium hydroxide, sodium silicate and water as main components, manufactured by Okamoto Chemical Industry Co., Ltd.). 30 at 25 ° C with diluent
Immersion development was performed for 2 seconds. Using the obtained lithographic printing plate, proof printing and printing with a printing machine were performed, and evaluation was made on sponge suitability, printing durability, and stain resistance by the following evaluation methods. Table 2 shows the results.

[Evaluation of Sponge Suitability] The printing plates obtained from (Substrate I) and (Substrate II) were placed on a proofing machine, and rubbed several times back and forth and right and left with a sponge containing water. ：: The surface has good slipperiness and no sponge residue. Δ: No sponge scum appeared, but the surface slippage was poor. ×: Poor surface slipperiness, sponge scum appears.

[Evaluation of Printing Durability] (Substrate I) and (Substrate I)
The printing plate obtained in II) is set on an offset printing machine, and after printing about 20,000 copies, the image area is evaluated. ：: There is no abnormality in the image area, ink is well applied, and high printing durability is expected. ×: There is a very fine portion in the solid portion of the image portion, but there is a portion where the image is peeled and a grain is visible, and the portion is missing in a pinhole shape in the printed matter.

[Evaluation of Contamination] (Substrate I) and (Substrate I)
The printing plate obtained from II) is set on an offset printing machine,
After printing all copies, the non-image portions are evaluated. ：: There is no abnormality in the non-image portion, and there is no dot-like stain. ×: A part of the non-image portion is shining due to abrasion on the surface, and the portion is stained dotted.

[0036]

[Table 2]

Example 2 and Comparative Example 2 An aluminum plate was brush-polished and alkali-etched in the same manner as in Example 1, and then the same pressure roller as in Example 1 was used.
The same pressure was applied and then electropolished at 200 coulombs / dm ² in a 1N hydrochloric acid bath. After washing with water, alkali etching was performed with the same composition as in Example 1. After washing with water, a resin roll having a hardness of 95 was used as an upper roll also as a draining roll, and a nitrile rubber roll having a hardness of 70 was used as a lower roll.
At a total weight of 100 kg, 0.8 kg was added per 1 cm width. The peripheral speed of the upper and lower rolls was rotated 5% faster than the transport speed of the aluminum plate. The support treated in this manner by applying the pressure roll twice was used in Example 2 (substrate III).
And A support treated by passing the pressure roll without applying the pressure roll twice is referred to as Comparative Example 2 (substrate IV). Thereafter, (Substrate III) and (Substrate IV) were anodized in the same manner as in Example 1, washed with water and dried. At this time (substrate III),
The surface roughness of (Substrate IV) was measured, and the values of average roughness Ra and maximum peak height Rp are shown in Table 1. Table 1 shows how the surface was observed at a magnification of 3000 with an electron microscope (SEM). From Table 1, the low Rp value of the substrate III indicates that there are few sharply protruding portions.

Subsequently, a photosensitive solution (2) having the following composition was applied by a rubber coater so that the applied weight after drying was 1.8 g / m ² to provide a photosensitive layer. Photosensitive solution (2) 2-hydroxy-3-phenoxypropyl methacrylate / 2-hydroxyethyl methacrylate / methacrylic acid / methyl methacrylate / acrylonitrile = copolymer having a weight ratio of 30/20/5/20/25: 30 g 4-diazo 2-Methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid as a condensate of diphenylamine and formaldehyde: 3 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Industries): 0.1 g oxalic acid: 0.3 g ethylene glycol monomethyl ether: 90 g N, N-dimethylformamide 10g

Table 1 shows the application state of the photosensitive liquid on (substrate III) and (substrate IV) at this time. The negative lithographic printing plate obtained from (Substrate III) and (Substrate IV) is brought into close contact with a negative original film having halftone dots and fine lines, and irradiated with light from a distance of 1 m for 40 seconds using a 3 kW metal halide lamp as a light source. Exposure. The exposed photosensitive lithographic printing plate is treated with a commercially available developer (Sylvan Negative Developer, Okamoto Chemical Industries, Ltd., a developer mainly composed of phenyl cellosolve, potassium silicate, anionic surfactant and water). It was immersed and developed with a 2 × dilution at 25 ° C. for 30 seconds. Using the obtained lithographic printing plate, proof printing and printing with a printing machine were performed, and evaluation was performed on sponge suitability, printing durability, and stain resistance in the same manner as in Example 1. Table 2 shows the results. The evaluation criteria are the same as in the first embodiment.

Example 3 and Comparative Example 3 An aluminum plate having a thickness of 0.30 mm and a width of 1000 mm was thoroughly degreased and washed with water, and then placed in a 1.5 wt% nitric acid bath.
Electropolishing was performed at 00 coulomb / dm ² . After washing with water, 5 g / m ² alkali etching was carried out with the same composition as in Example 1. After washing with water, acid washing with 30% by weight of nitric acid was carried out. Nylon (manufactured by Nippon Polypenco Co.) was covered with 15 mm, and nitrile rubber having a hardness of 65 degrees was used for the lower roll, and a pressure of 1.5 kg or more per 1 cm width was applied under a total weight of 200 kg. The peripheral speed of the upper and lower rolls was rotated by 3% lower than the transport speed of the aluminum plate. The support processed by applying the pressure roll is referred to as Example 3 (substrate V). On the other hand, a support that was processed by passing through a pressure roll without applying the pressure roll is referred to as Comparative Example 3 (substrate VI). Thereafter, (Substrate V) and (Substrate VI) were anodized in the same manner as in Example 1, washed with water and dried.

At this time, the surface roughness of (substrate V) and (substrate VI) was measured, and the values of average roughness Ra and maximum peak height Rp are shown in Table 1. In addition, the surface was measured with an electron microscope (SEM).
Table 1 shows the observation at a magnification of 000. From Table 1, the fact that the Rp value of the substrate V is low indicates that there are few sharply projected portions. Subsequently, the photosensitive solution (1) was applied by a rubber coater so that the applied weight after drying was 1.8 g / m ² to form a photosensitive layer. At this time (substrate V),
Table 1 shows the state of application of the photosensitive solution on (Substrate VI).

The photosensitive lithographic printing plates obtained from (Substrate V) and (Substrate VI) were exposed and developed in the same manner as in Example 1. Using the obtained lithographic printing plate, proof printing and printing were performed by a printing machine, and the sponge suitability was the same as in Example 1,
Evaluation was made on printing durability and stain resistance. Table 2 shows the results.
Shown in The evaluation criteria are the same as in the first embodiment.

[0043]

The support for a lithographic printing plate of the present invention has good surface slipperiness, and therefore has less surface scratches and excellent sponge suitability. Further, when the photosensitive composition is applied to the support, Is an excellent plate having no coating unevenness and cissing, and having no printing durability and dot-like stains during printing.

Claims (7)

[Claims] In a method for producing a lithographic printing plate support, wherein the surface of an aluminum plate is mechanically and / or electrochemically polished, then chemically polished, and then subjected to anodizing treatment, the method may be carried out in the course of the various steps. A method for producing a lithographic printing plate support, comprising a step of pressing at least one or more locations from both sides with a pair of rollers. 2. A pair of rollers, wherein a roll in contact with a polishing surface of the aluminum plate is a metal roll or
The lithographic printing plate according to claim 1, wherein the resin roll has a hardness of 90 degrees or more based on a JIS K 6301 spring hardness test, and the roll in contact with the back surface of the aluminum plate is a rubber roll having a hardness of 50 to 90 degrees. A method for producing a printing plate support. 3. The method for producing a lithographic printing plate support according to claim 1, wherein the pressure applied from both sides by the pair of rollers is 0.8 kg / cm or more per roll width. 4. The diameter of the pair of rollers is 100 to 30.
The method for producing a lithographic printing plate support according to claim 1, wherein the thickness is 0 mm. 5. The lithographic printing plate support according to claim 1, wherein the processing is performed by changing the peripheral speed of the pair of rollers within ± 10% of the conveying speed of the aluminum plate. Method. 6. A lithographic printing plate support obtained by using the method for producing a lithographic printing plate support according to claim 1. 7. A photosensitive lithographic printing plate comprising the lithographic printing plate support according to claim 6 coated with a photosensitive composition.