JPH10138652A - Support for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support for a lithographic printing plate with remarkably improved properties such as being hardly soiled, for printing, and plate wear. SOLUTION: The support for a lithographic printing plate has the roughed surface of an aluminum plate or an aluminum alloy plate. When pits generated by chemical etching process after electrochemical roughing process is electromicroscopically examined, the ratio of pits, those of which come into contact directly with the peripheries of some pits without being through a plain part and total 4-8 on the average and those of which come into contact directly with the peripheries and total 3 or less, is 20% or less. Further, the ratio of pits of at least 10 pieces in direct contact with the peripheries is 20% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support for a lithographic printing plate, and more particularly to a support for a lithographic printing plate which has an optimum surface shape as a support, and is excellent in stain resistance and printing durability.

[0002]

2. Description of the Related Art As a support for a lithographic printing plate, an aluminum plate or an aluminum alloy plate (hereinafter abbreviated as "aluminum plate") has been widely used. In order to use this aluminum plate as a lithographic printing plate support, it is necessary to improve the adhesion to a photosensitive layer provided on the lithographic printing plate support, and to form a lithographic printing plate using the same. The surface is usually roughened for the purpose of improving the water retention of the non-image area of the plate (the area that receives the fountain solution used during printing and repels the oil-based ink).

As a method for roughening an aluminum plate, there are a mechanical roughening treatment, a chemical etching treatment, an electrochemical roughening treatment, and the like. It describes a method for specifying various conditions in the surface treatment, the chemical etching treatment, and the electrochemical surface roughening treatment. According to the above publication, after the mechanical surface roughening treatment, a chemical etching treatment is performed so as to have an etching amount of 0.5 to 30 g / m ^2, and then the electrochemically roughening treatment is performed at an appropriate current density and an electric quantity. After that, the surface is chemically etched in an etching amount of 0.1 to 10 g / m ² , and the corners of the irregularities generated by the electrochemical roughening in the preceding stage are smoothly finished, and anodizing treatment is performed. It has been proposed to do so. These supports had insufficient blanket stain performance, and had a trade-off relationship with the deterioration of flaw stain performance when trying to improve blanket stain.

[0004]

The pits formed by the roughening have a remarkable effect on the printing performance of the printing plate, such as stain resistance, printing durability, and the like. It has become. Here, a pit is a hemispherical concave portion formed by electrolytic surface roughening. The present invention has been made in view of such a situation, and an object of the present invention is to provide a lithographic printing plate support excellent in characteristics such as stain resistance and printing durability.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that the pits between the pits after the chemical roughening treatment and the chemical etching treatment have been performed. Observing the contact state is an effective means of evaluating the surface roughening treatment, and also improves the lithographic printing plate's resistance to contamination and printing durability when using an aluminum plate with pits that meet specific conditions as a support. To complete the present invention. That is, the lithographic printing plate support according to the present invention has a structure in which a pit formed by performing a chemical etching treatment following an electrochemical surface roughening treatment and surrounding a certain pit is observed by an electron microscope (SEM). The average number of pits that are in direct contact with each other without passing through a flat part is 4
The ratio of the pits where the number of directly contacting pits is 3 or less is 20% or less, and the ratio of the pits where the number of directly contacting pits is 10 or more is 20 or less.
% Or less.

In the above description, although the pits are hemispherical, they may be slightly deformed or overlap depending on electrolysis conditions, aluminum material, etc., and may not always be hemispherical. Measure as one pit as long as it can be recognized. The state of direct contact includes both a state in which pits are in contact at one point (point contact) and a state in which pits are in contact with a certain line segment (line contact). The number of pits in direct contact depends on the pit generation density and the diameter of each pit.
In other words, when the average value of the number of directly contacting pits exceeds 8, the state where many small-diameter pits are in contact with an extremely large-diameter pit is allowed, and the pit size is reduced. It is not preferable from the point of uniformity. On the other hand, when the average value is less than 4, even if the pit diameters are uniform, the pits are scattered or exist linearly, which is not preferable because the distribution density is low. For similar reasons,
If the proportion of pits with 3 or less directly contacting pits exceeds 20%, the density of pits generated is too low, and the proportion of pits with 10 or more directly contacting pits is low. If it exceeds 20%, the existence of a large number of large-diameter pits and small-diameter pits is allowed. The average value of the number of directly contacting pits is more preferably 5 to 7, and the ratio of pits having 3 or less directly contacting pits is more preferably 1%.
0% or less, and the proportion of pits in which the number of directly contacting pits is 10 or more is more preferably 10% or less. The above pit contact conditions can be realized by appropriately setting the conditions of the electrochemical surface roughening process and the subsequent chemical etching process in a series of surface roughening process steps described later. it can.

[0007] The magnification of the SEM for observation is not particularly limited as long as it is a magnification capable of visually discriminating the contact state of the pits, but it is determined by electrochemical roughening and subsequent chemical etching. The size of the pit to be generated is usually about 0.1 to 20 μm, and in order to identify a pit of this size, it is generally 1000 to 50 μm.
It is appropriate to make the magnification of 00 times. Also, this SE
Observation by M may be performed at any time after the surface roughening treatment, after the electrochemical surface roughening treatment and the subsequent chemical etching treatment are performed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The lithographic printing plate support of the present invention will be described in detail below with reference to preferred production methods. The aluminum plate used as the support in the present invention includes pure aluminum and aluminum alloy. Various aluminum alloys can be used,
For example, silicon, copper, manganese, magnesium, chromium,
An alloy of aluminum, such as an alloy such as zinc, lead, nickel, and bismuth, is used. There are various types of aluminum alloys.
In US Pat. No. 6,635, the Fe and Si components are limited, and an intermetallic compound is specified. In addition, Japanese Patent Publication No. 55-28874
In the publication, the cold rolling ratio and the intermediate blunting are performed, and the voltage application method for electrolytic surface roughening is limited. Tokiko Sho 62-4130
4, Tokiko 1-46577, Tokiko 1-446578, Tokiko 1-47545, Tokiko 1-35910, Tokiko Sho 6
3-60823, JP-B 63-60824, JP-B 4-
13417, Tokuhei 4-19290, Tokuhei 4-192
91, Tokuhei 4-19293, Tokiko 62-5054
0, JP-A-61-272357, JP-A-62-7406
0, JP-A-61-201747, JP-A-63-14432
34, JP-A-63-143235, JP-A-63-255
338, JP-A-1-283350, EP272
528, U.S. Patent Nos. 4,902,353 and 4,818,300;
EP394816, U.S. Pat. No. 5,019,188, West German Patent 3,232,810, U.S. Pat.
9995, U.S. Pat. No. 4,822,715, West German Patent 35
07402, U.S. Pat. No. 4,715,903, West German Patent 3
507402, EP289844, US Patent 50097
22, 495,004, West German Patent 371405
9, U.S. Pat. Nos. 4,686,083 and 4,861,396, EP
It includes not only the aluminum alloys described in the specifications of the 158941 specification, but also all general ones. As a method for manufacturing a sheet material, a method using continuous casting as well as a method using hot rolling has been recently applied for. For example, in the specification of East German Patent 252799, a plate material performed by a twin roll method is introduced. EP 223737,
In each of U.S. Pat. Nos. 4,802,935 and 4,800,950, an application is made with a limited amount of a minor alloy component. E
P415238 proposes continuous casting, continuous casting + hot rolling. In the present invention, an excellent photosensitive lithographic printing plate is obtained by performing various surface treatments, transfer, and the like on such an aluminum plate to form a printing original plate having uniform unevenness, and providing a photosensitive layer such as a diazo compound thereon. Becomes In any case, it is necessary to select an appropriate material.

[0009] Before the surface roughening treatment, a pretreatment may be performed as necessary. This pretreatment is typically performed by removing the rolling oil on the aluminum plate surface using a solvent such as trichlene or a surfactant, or cleaning the aluminum plate surface using an alkali etching agent such as sodium hydroxide or potassium hydroxide. This is the exposure of the aluminum plate surface. Specifically, as a solvent degreasing method, a method using petroleum solvents such as gasoline, kerosene, benzene, solvent naphtha, normal hexane, trichloroethylene, methylene chloride, perchlorethylene, 1,1,1-trichloroethane, etc. Using a chlorine-based solvent. Examples of the alkali degreasing method include a method using an aqueous solution of a soda salt such as sodium hydroxide, sodium carbonate, sodium bicarbonate, and sodium sulfate; sodium orthosilicate, sodium metasilicate, sodium disilicate, sodium silicate, and the like. A method using an aqueous solution of a silicate, a method using an aqueous solution of a phosphate such as sodium phosphate monobasic, sodium phosphate tribasic, sodium phosphate dibasic, sodium tripolyphosphate, sodium pyrophosphate, sodium hexametaphosphate, and the like can be given. When the alkali degreasing method is used, the aluminum surface may be dissolved depending on the treatment time and the treatment temperature. Therefore, it is necessary to avoid the dissolution phenomenon in the degreasing treatment. As the degreasing treatment with a surfactant, an aqueous solution of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant is used, and various commercially available products can be used. As the degreasing method, the dipping method,
A spraying method, a method in which a liquid is immersed in a cloth or the like, and rubbed can be used. Ultrasonic waves may be used for the dipping or spraying method. Regarding the above degreasing treatment, for example,
No. 6,793, can be referred to.

Next, it is preferable to perform a mechanical roughening treatment. There are methods such as transfer, brush, and liquid honing for the mechanical surface roughening, and they can be used together in consideration of productivity and the like. Various methods can be used as a transfer method for pressing the uneven surface against the aluminum plate. That is,
The above-mentioned JP-A-55-74898 and JP-A-60-361.
No. 95, Japanese Unexamined Patent Publication No. 60-203496, and Japanese Patent Application No. 4-175945, in which transfer is performed several times, and Japanese Patent Application No. 4-175945, in which the surface is elastic.
No. 204235 is also applicable. In addition, by using electrical discharge machining, shot blasting, laser etching, plasma etching, etc., transfer can be performed repeatedly using a roll with fine irregularities etched, or the surface with irregularities coated with fine particles can be brought into contact with an aluminum plate. The concave and convex pattern corresponding to the average diameter of the fine particles may be repeatedly transferred to the aluminum plate a plurality of times by applying pressure repeatedly thereon. Japanese Patent Application Laid-Open Nos. 3-8635 and 3-66404 disclose methods for imparting fine irregularities to the transfer roll.
And JP-A-63-65017 are known. Further, fine grooves may be cut on the roll surface from two directions using a dice, a cutting tool, a laser, or the like, so that the surface has square irregularities. The roll surface may be subjected to a known etching process or the like, so that the formed square irregularities are rounded. Of course, quenching, hard chrome plating or the like may be performed to increase the surface hardness.

When a brush is used, the flexural modulus is 10,
000-40,000 kg / cm ² , preferably 15,
Using brush bristles of 000 to 35,000 kg / cm ² and bristle strength of 500 g or less, preferably 400 g or less, the particle size is further 20 to 80 μm, preferably 30 to
It is preferable to use an abrasive of up to 60 μm. The material of the brush is not particularly limited as long as it has the above-mentioned mechanical strength, and can be appropriately selected from, for example, synthetic resin and metal.
Examples of the synthetic resin include polyamide such as nylon, polyolefin such as polypropylene, polyester such as polyvinyl chloride and polybutylene terephthalate, and polycarbonate. As metal,
Examples include stainless steel and brass. In addition, the material of the abrasive is not limited as long as the material is in the above-mentioned particle size range, and alumina, silica, silicon carbide, silicon nitride, and the like conventionally used for mechanical surface roughening treatment are used. Selected. The mechanical surface-roughening treatment is performed by pressing the roll brush having the bristles on the aluminum plate surface while rotating at high speed, and supplying the abrasive to the roll brush. At this time, the rotation speed of the roll brush, the pressing force, the supply amount of the abrasive, and the like are not particularly limited. As an apparatus suitable for the mechanical surface roughening, for example, an apparatus described in Japanese Patent Publication No. 50-40047 can be mentioned.

After the mechanical surface roughening treatment, the aluminum surface is chemically etched with an alkaline solution having a pH of 11 or more, preferably pH 13 or more, for the purpose of smoothing and equalizing the aluminum plate. I do. The etching amount is 5 g / m ² or more and 25 g / m ² or less, preferably 6 g / m ² or more and 15 g / m ² or less. If the etching amount is less than 5 g / m ² , the unevenness formed by the mechanical surface roughening treatment cannot be smoothed, and uniform pits cannot be generated in the subsequent electrolytic treatment. On the other hand, if the etching amount exceeds 25 g / m ² , the irregularities disappear.
Examples of usable alkaline solutions include aqueous sodium salt solutions such as sodium hydroxide, sodium carbonate, sodium bicarbonate, and sodium sulfate; and silicic acids such as sodium orthosilicate, sodium metasilicate, sodium disilicate, and sodium silicate. Aqueous salt solution, sodium phosphate monobasic,
Aqueous phosphate solutions such as sodium diphosphate, tertiary sodium phosphate, sodium tripolyphosphate, sodium pyrophosphate, sodium hexametaphosphate and the like can be mentioned. The treatment conditions are as follows: the concentration of the alkaline solution is 0.01%.
５０50% by weight, liquid temperature 20 ° C.-90 ° C., time 5 seconds-5 minutes, and are appropriately selected so as to achieve the above-mentioned etching amount.

When the surface of the aluminum plate is chemically etched with the above alkaline solution, an insoluble residue, ie, a smut, is formed on the surface. Therefore, the smut is removed using an acidic solution having the same composition as the acidic solution used for the electrolytic surface roughening treatment described later. Preferred processing conditions are a liquid temperature of 30 to 80 ° C. and a time of 3 seconds to 3 minutes.

Next, an electrolytic surface roughening treatment which is a necessary step of the present invention is performed. In the electrolytic surface roughening treatment in the present invention, it is preferable to perform first and second electrolytic treatments using an alternating waveform current in an acidic solution before and after the cathodic electrolytic treatment. By the cathodic electrolysis, smut is generated on the surface of the aluminum plate, and hydrogen gas is generated, so that more uniform electrolytic surface roughening is possible. First, the first and second electrolytic surface roughening treatments using an alternating waveform current in an acidic solution will be described.
In this electrolytic surface roughening treatment, the first treatment and the second treatment may be performed under the same conditions, or may be different in the range of preferable processing conditions. This electrolytic surface roughening treatment can be performed, for example, according to the electrochemical graining method described in JP-B-48-28123 and British Patent 896563. This electrolytic graining uses an alternating current having a sine waveform.
The measurement may be performed using a special waveform as described in Japanese Patent No. 58602. Further, a waveform described in JP-A-3-79799 can also be used. In addition, Japanese Unexamined Patent Publication No.
5-158298, JP-A-56-28898, JP-A-Showa 5
2-58602, JP-A-52-152302, JP-A-5-152302
4-85802, JP-A-60-190392, JP-A-5-1985
8-120531, JP-A-63-176187, JP-A-1-58889, JP-A-1-280590, JP-A-1-118489, JP-A-1-148592, JP-A-1-178496, JP-A-1-188315, JP-A-1-154797, JP-A-2-235794, JP-A-3
-260100, JP-A-3-253600, JP-A-4-
72079, JP-A-4-72098, JP-A-3-267
400, and the methods described in JP-A Nos. 1-141094 can also be applied. As the frequency, in addition to the above, those proposed for an electrolytic capacitor can be used. For example, U.S. Patent Nos. 4,276,129 and 4,676,879.

Examples of the acidic solution as an electrolytic solution include nitric acid, hydrochloric acid, and the like, as well as US Pat.
4661219, 4618405, 46262
8, 4600482, 4566960, 4566
958, 4566959, 4416972, 43
Electrolyte solutions described in each of 74710, 4336113, and 4184932 can also be used. The concentration of the acidic solution is 0.
The content is preferably 5 to 2.5% by weight, and particularly preferably 0.5 to 1.5% by weight in consideration of the use in the above-mentioned smut removal treatment. Further, the liquid temperature is 30 to 60 ° C, particularly 35 to 50 ° C.
C is preferred.

Various electrolytic cells and power supplies have been proposed, but are disclosed in US Pat.
123400, JP-A-57-59770, JP-A-53-570
12738, JP-A-53-32821, JP-A-53-3283
2822, JP-A-53-32823, JP-A-55-12
2896, JP-A-55-132883, JP-A-62-1
27500, JP-A-1-52100, JP-A-1-520
98, JP-A-60-67700, JP-A-1-23080
And JP-A-3-257199. In addition to the above-mentioned patents, various proposals have been made. For example, JP-A-52-58602, JP-A-52-1
52302, JP-A-53-12738, JP-A-53-1
2739, JP-A-53-32821, JP-A-53-32
822, JP-A-53-32833, JP-A-53-328
24, JP-A-53-32825, JP-A-54-8580
2, JP-A-55-122896, JP-A-55-1328
84, JP-B-48-28123, JP-B-51-708
1, JP-A-52-133838, JP-A-52-1338
40, JP-A-52-133844, JP-A-52-133
845, JP-A-53-149135, JP-A-54-14
Of course, those described in JP-A-6234 can be applied.

In this electrolytic treatment, the anode electricity is 50 to 400
C / dm ^2, preferably at 120~300C / dm ^2. If the anode charge is less than 50 C / dm ² , the pit density will not reach a sufficient level, while if it exceeds 400 C / dm ² , large diameter pits and small diameter pits will be mixed.

During the first and second electrolytic surface roughening treatments, the aluminum plate is subjected to a cathodic electrolytic treatment. By this cathodic electrolysis, a smut is generated on the surface of the aluminum plate, and a hydrogen gas is generated so that a more uniform electrolytic surface roughening can be achieved. This cathodic electrolysis is carried out in an acidic solution at a cathodic electricity of 3 to 80 C / dm ² , preferably 5 to 30 C / dm ² .
/ Dm ² . Cathode in the amount of electricity is less than 3C / dm ^2, insufficient smut adhesion amount, whereas if it exceeds 80C / dm ^2, not desirable smut adhering amount is excessive. Further, the electrolytic solution may be the same as or different from the solution used in the first and second electrolytic surface roughening treatments.

After the second electrolytic surface roughening treatment, the aluminum plate is subjected to a second chemical etching treatment using an alkaline solution having a pH of 11 or more. The alkaline solution having a pH of 11 or more used in the second chemical etching treatment may be the same as the alkaline solution used in the first chemical etching treatment, or may be a different alkaline solution. However, unlike the first chemical etching treatment, the etching amount is 0.1 to 8 g / m ² , preferably 0.2 to 8 g / m ² .
3.0 g / m ² . Etching amount is 0.1 g / m ²
If it is less than 10%, the pit ends obtained by the electrolytic treatment cannot be smoothed, while if it exceeds 8 g / m ² , the pits disappear.

Since a smut is generated by the above-mentioned chemical etching, the smut is removed from the aluminum plate using a solution mainly composed of sulfuric acid. Here, the solution mainly composed of sulfuric acid means not only a sulfuric acid alone solution but also phosphoric acid, nitric acid,
It is a mixed solution obtained by appropriately mixing chromic acid, hydrochloric acid and the like.
For the removal of the smut using a solution mainly containing sulfuric acid, for example, JP-A-53-12739 can be referred to. Further, alkali treatment may be combined, and for example, JP-A-56-51388 can be referred to. Further, JP-A-60-8091, JP-A-63-176
188, JP-A-1-38291, JP-A-1-12738
9, JP-A-1-188699, JP-A-3-17760
0, JP-A-3-126891, JP-A-3-191100
The methods described in each publication can be used in combination.

Next, an anodic oxide film is formed on the surface of the aluminum plate. For example, a sulfuric acid concentration of 50 to 300 g /
In step (1), an anodized film can be formed in a solution having an aluminum concentration of 5% by weight or less by using an aluminum plate as an anode. Phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid and the like may be added to the solution. The amount of the oxide film formed is 1.0 to 5.0 g /
m ² , particularly preferably 1.5 to 4.0 g / m ² . The anodizing treatment conditions vary depending on the electrolytic solution to be used, and thus cannot be determined unconditionally. The range is 5 to 60 A / cm ² , the voltage is 1 to 100 V, and the electrolysis time is 15 seconds to 50 minutes. As an electrolysis apparatus, Japanese Patent Application Laid-Open No. 48-266
38, JP-A-47-18739, JP-B-58-2451.
It is introduced in 7 publications. Also, Japanese Patent Application Laid-Open No. 54-8 / 1979
1133, JP-A-57-47894, JP-A-57-51
289, JP-A-57-51290, JP-A-57-543
00, JP-A-57-136596, JP-A-58-107
498, JP-A-60-200256, JP-A-62-13
6596, JP-A-63-176494, JP-A-4-17
6897, JP-A-4-280997, JP-A-6-207
299, JP-A-5-24377, JP-A-5-3208
3, JP-A-5-125597, JP-A-5-195291
The methods described in each publication can also be used.

After forming the anodic oxide film as described above,
In order to optimize the adhesion between each support and the photosensitive composition, after etching the anodic oxide film, steam and
There is an apparatus for sealing a support which gives a photosensitive printing plate which is sealed with hot water, has good stability over time, has good developability, and has no stain on the non-image area. The post-treatment of film formation may be performed by such an apparatus. Also, JP-A-4-4194, Japanese Patent Application No. 4-33
952, Japanese Patent Application No. 4-33951, Japanese Patent Application No. 3-31524
5 The sealing treatment may be performed by an apparatus or a method described in the specification of each item.

Other examples include the treatment with potassium fluorozirconate described in US Pat. No. 2,946,638 and the treatment of phosphomolybdate described in US Pat. No. 3,012,247 with British Patent No. 1108559. Alkyl titanate treatment, German Patent No. 109
No. 1433, polyacrylic acid treatment, German Patent No. 1134093 and British Patent No. 1
No. 2304747, polyvinylphosphonic acid treatment, JP-B-44-6409, phosphonic acid treatment, U.S. Pat. No. 3,307,951, phytic acid treatment, JP-A-58. -16
No. 893 or JP-A-58-18291, and treatment with a salt of a lipophilic organic polymer compound with a divalent metal, as described in US Pat. No. 3,860,426. An undercoat layer of hydrophilic cellulose (for example, carboxymethylcellulose, etc.) containing a water-soluble metal salt (for example, zinc acetate, etc.);
No. 101651, a water-soluble polymer having a sulfonic acid group which has been subjected to a hydrophilizing treatment by undercoating, a phosphate described in JP-A-62-19494, and a phosphate described in JP-A-62-19494. Water-soluble epoxy compound described in JP-A-03-03692, JP-A-62-097
No. 892, phosphoric acid-modified starch,
No. 056498, a diamine compound described in JP-A-63-130391, an inorganic or organic acid of an amino acid described in JP-A-63-130391, an organic phosphonic acid containing a carboxyl group or a hydroxyl group described in JP-A-63-145092, Compounds having an amino group and a phosphonic acid group described in JP-A-63-165183, specific carboxylic acid derivatives described in JP-A-2-316290, JP-A-3-21509
Patent No. 5, JP-A-3-2615
No. 92, one amino group and oxygen acid group 1 of phosphorus
Compounds having a single bond, phosphates described in JP-A-3-215095, aliphatic or aromatic phosphonic acids such as phenylphosphonic acid described in JP-A-5-246171, and JP-A-1-307745. Compounds containing an S atom, such as thiosalicylic acid described in JP-A-4-28.
Undercoating, such as a compound having an oxygen acid group of phosphorus, described in JP-A-2637, and coloring with an acid dye described in JP-A-60-64352 can also be performed.

The support for a lithographic printing plate according to the present invention can be obtained by the above-described roughening treatment. By observing the state of pit formation by SEM, it is confirmed that the pit contact state satisfies the above conditions. After confirmation, a photosensitive lithographic printing plate can be prepared by providing a photosensitive layer as exemplified below.

[I] A case where a photosensitive layer containing a novolak resin of a mixture of o-naphthoquinonediazidesulfonic acid ester and phenol / cresol is provided. The o-quinonediazide compound is an o-naphthoquinonediazide compound, for example, U.S. Pat. No. 2,766,118.
No. 2,767,092, No. 2,772,97
No. 2, No. 2,859,112, No. 3,102,8
09, 3,106,465 and 3,635
No. 709, No. 3,647,443, and many other publications, and these can be suitably used. Among these, o-naphthoquinonediazidesulfonic acid ester or o-naphthoquinonediazidocarboxylic acid ester of an aromatic hydroxy compound, and o-naphthoquinonediazidosulfonic acid amide or o-naphthoquinonediazidecarboxylic acid amide of an aromatic amino compound are particularly preferable. In particular, US Pat.
U.S. Pat. No. 4,028,1 which is obtained by subjecting a condensate of pyrogallol and acetone to an ester reaction with o-naphthoquinonediazidosulfonic acid described in US Pat.
No. 11, a polyester having a hydroxy group at a terminal, obtained by subjecting an o-naphthoquinonediazidesulfonic acid or an o-naphthoquinonediazidecarboxylic acid to an ester reaction, described in British Patent No. 1,494,043. A homopolymer of p-hydroxystyrene or a copolymer thereof with another copolymerizable monomer as described, which is subjected to an ester reaction with o-naphthoquinonediazidosulfonic acid or o-naphthoquinonediazidocarboxylic acid; Copolymers of p-aminostyrene and other copolymerizable monomers, as described in U.S. Pat. No. 3,759,711, may be treated with o-naphthoquinonediazidesulfonic acid or o-naphthoquinonediazidecarboxylic acid. Is very excellent.

These o-quinonediazide compounds can be used alone, but are preferably used in combination with an alkali-soluble resin. Suitable alkali-soluble resins include novolak-type phenol resins, and specifically include phenol formaldehyde resin, o-cresol formaldehyde resin, m-cresol formaldehyde resin, and the like. No. 4,028, U.S. Pat.
As described in JP-A-111, a condensate of formaldehyde with phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms, such as a t-butylphenol formaldehyde resin, is used in combination with the phenol resin described above. Then, it is even more preferable. Further, to form a visible image by exposure, o-naphthoquinonediazide-4-sulfonyl chloride, inorganic anion salt of p-diazodiphenylamine, trihalomethyloxadiazole compound, trihalomethyloxadiazole compound having a benzofuran ring, etc. Compounds and the like are added. On the other hand, a triphenylmethane dye such as Victoria Bull-BOH, crystal violet, oil blue, or the like is used as a colorant for an image. Also, Japanese Patent Application Laid-Open No. 62-2932
The dye described in JP-B-47 is particularly preferred. Further, a phenol substituted with an alkyl group having 3 to 15 carbon atoms such as t-butyl phenol, N-type as described in JP-B-57-23253 is used as a sensitizer.
Octylphenol, a novolak resin obtained by condensing t-butylphenol with formaldehyde, or o-naphthoquinonediazide-4 of such a novolak resin
-Or -5-sulfonic acid ester (for example, see
1-2242446). Further, in order to improve the developability, a nonionic surfactant as described in JP-A-62-251740 can be further contained. The above composition is dissolved in a solvent that dissolves each of the above components, and coated on a support. As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, lactic acid Methyl, ethyl lactate, dimethyl sulfoxide, dimethylacetamide,
Examples include dimethylformamide, water, N-methylpyrrolidone, tetrahydrofurfuryl alcohol, acetone, diacetone alcohol, methanol, ethanol, isopropanol, and diethylene glycol dimethyl ether. These solvents are used alone or in combination. The photosensitive composition comprising these components has a solid content of 0.1%.
5 to 3.0 g / m ^{2 is} provided.

[II] When a photosensitive layer containing a diazo resin and a water-insoluble and lipophilic photomolecular compound is provided. As the diazo resin, for example, a diazo resin inorganic salt which is a reaction product of a condensate of p-diazodiphenylamine and formaldehyde or acetaldehyde with hexafluorophosphate, tetrafluoroborate, and an organic solvent, and US Pat. No. 3,300,309, the condensate and a sulfonic acid such as p
-Toluenesulfonic acid or a salt thereof, phosphinic acids such as benzenephosphinic acid or a salt thereof, and a hydroxyl group-containing compound such as 2,4-dihydroxybenzophenone or 2-hydroxy-4-methoxybenzophenone-
Organic solvent-soluble diazo resin organic acid salts, which are reaction products such as 5-sulfonic acid or salts thereof, and the like. In the present invention, other diazo resins that can be suitably used include a carboxyl group, a sulfonic acid group, a sulfinic acid group,
It is a cocondensate containing, as a structural unit, an aromatic compound having at least one organic group of an oxygen acid group and a hydroxyl group of phosphorus and a diazonium compound, preferably an aromatic diazonium compound. The aromatic ring preferably includes a phenyl group and a naphthyl group. As the aromatic compound containing at least one of the above-mentioned carboxyl group, sulfonic acid group, sulfinic acid group, oxygen acid group of phosphorus, and hydroxyl group, various compounds can be mentioned, but 4-methoxy is preferable. Benzoic acid, 3-chlorobenzoic acid, 2,4-dimethoxybenzoic acid, p-phenoxybenzoic acid, 4-anilinobenzoic acid, phenoxyacetic acid, phenylacetic acid, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, benzene Sulfonic acid, p-toluenesulfinic acid, 1-naphthalenesulfonic acid, phenylphosphoric acid, and phenylphosphonic acid. Examples of the aromatic diazonium compound constituting the constitutional unit of the aforementioned co-condensed diazo resin include, for example, JP-B-49-48001.
Although diazonium salts such as those described in JP-A No. 2-2,086 can be used, diphenylamine-4-diazonium salts are particularly preferred. Diphenylamine-4-diazonium salts are derived from 4-amino-diphenylamines, and such 4-amine-diphenylamines include 4-aminodiphenylamine, 4-amino-3-methoxydiphenylamine, 4-amino- 2-methoxydiphenylamine, 4'-amino-2-methoxydiphenylamine, 4'-amino-4-methoxydiphenylamine, 4-amino-3-methyldiphenylamine, 4-amino-3-ethoxydiphenylamine, 4-
Amino-3-β-hydroxyethoxydiphenylamine, 4-amino-diphenylamine-2-sulfonic acid,
4-amino-diphenylamine-2-carboxylic acid, 4-
Examples thereof include amino-diphenylamine-2′-carboxylic acid, and particularly preferably, 3-methoxy-4-amino-4.
-Diphenylamine and 4-aminodiphenylamine. Further, as a diazo resin other than a co-condensation diazo resin with an aromatic compound having an acid group, JP-A-4-18559.
, JP-A-3-163551 and JP-A-3-253
The diazo resin condensed with an aldehyde containing an acid group or an acetal compound thereof described in each of the publications of 857 can also be preferably used. The counter anion of the diazo resin includes an anion that forms a salt with the diazo resin stably and makes the resin soluble in an organic solvent. These include organic carboxylic acids such as decanoic acid and benzoic acid, organic phosphoric acids and sulfonic acids such as phenylphosphoric acid, and typical examples are fluoroalkanesulfonic acids such as methanesulfonic acid and trifluoromethanesulfonic acid. , Laurylsulfonic acid, dioctylsulfosuccinic acid, dicyclohexylsulfosuccinic acid, camphorsulfonic acid, tolyloxy-3-propanesulfonic acid, nonylphenoxy-3-propanesulfonic acid, nonylphenoxy-4-butanesulfonic acid, dibutylphenoxy-3-propanesulfonic acid Acid, diamylphenoxy-3-propanesulfonic acid, dinonylphenoxy-3-propanesulfonic acid, dibutylphenoxy-4-butanesulfonic acid, dinonylphenoxy-4-butanesulfonic acid, benzenesulfonic acid, toluenes Fonic acid, mesitylenesulfonic acid, p-chlorobenzenesulfonic acid, 2,5-dichlorobenzenesulfonic acid, sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, p-acetylbenzenesulfonic acid, 5-nitro-o-toluenesulfonic acid 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-chloro-5-nitrobenzenesulfonic acid, butylbenzenesulfonic acid, octylbenzenesulfonic acid, decylbenzenesulfonic acid, dodecylbenzenesulfonic acid, Butoxybenzenesulfonic acid, dodecyloxybenzenesulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, isopropylnaphthalensulfonic acid, butylnaphthalenesulfonic acid, hexylnaphthalene Fonic acid, octylnaphthalenesulfonic acid, butoxynaphthalenesulfonic acid, dodecyloxynaphthalenesulfonic acid, dibutylnaphthalenesulfonic acid, dioctylnaphthalenesulfonic acid, triisopropylnaphthalenesulfonic acid, tributylnaphthalenesulfonic acid, 1-naphthol-5-sulfonic acid, naphthalene -1-sulfonic acid, naphthalene-2-sulfonic acid,
Aliphatic and aromatic sulfonic acids such as 1,8-dinitro-naphthalene-3,6-disulfonic acid, dimethyl-5-sulfoisophthalate, 2,2 ′, 4,4′-tetrahydroxybenzophenone, Hydroxyl-containing aromatic compounds such as 2,3-trihydrooxybenzophenone and 2,2'4-trihydroxybenzophenone, halogenated Lewis acids such as hexafluorophosphoric acid and tetrafluoroboric acid,
HClO _4, HIO ₄ perhalogen acids such as including but not limited to this. Of these, particularly preferred are butyl naphthalene sulfonic acid, dibutyl naphthalene sulfonic acid, hexafluorophosphoric acid,
Hydroxy-4-methoxybenzophenone-5-sulfonic acid, dodecylbenzenesulfonic acid.

The molecular weight of the diazo resin used in the present invention can be arbitrarily determined by variously changing the molar ratio of each monomer and the condensation conditions, but is effective for the intended use of the present invention. To provide a molecular weight of about 400
~ 100,000, preferably about 800-8,
000 is suitable. Examples of the water-insoluble and lipophilic high molecular compound include copolymers having a molecular weight of usually from 100,000 to 200,000, having monomers shown in the following (1) to (15) as structural units. (1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, for example, N- (4-
Hydroxyphenyl) acrylamide or N- (4-
(Hydroxyphenyl) methacrylamide, o-, m-,
p-hydroxystyrene, o-, m-, p-hydroxyphenyl-acrylate or methacrylate; (2) acrylates and methacrylates having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl Methacrylate, 4-hydroxybutyl methacrylate (3) Unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, (4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, acrylic acid Amyl, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, benzyl acrylate, acrylic acid-2-
(Substituted) alkyl acrylates such as chloroethyl, glycidyl acrylate, N-dimethylaminoethyl acrylate,

(5) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, glycidyl methacrylate, (substituted) alkyl methacrylate such as N-dimethylaminoethyl methacrylate, (6) acrylamide, methacryl Amide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl- Acrylamide or methacrylamides such as N-phenylacrylamide, (7) Vinyl ethers such as tyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether; (8) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, and vinyl benzoate (9) Styrenes such as styrene, α-methylstyrene and chloromethylstyrene; (10) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone;

(11) olefins such as ethylene, propylene, isobutylene, butadiene, isoprene, (12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc. (13) maleimide, N Unsaturated imides such as -acryloylacrylamide, N-aceketylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide, (14) N (o-aminosulfonylphenyl) methacrylamide, N- (M-aminosulfonylphenyl) methacrylamide, N- (p-amino) sulfonylphenylmethacrylamide, N- (1- (3-aminosulfonyl) naphthyl) methacrylamide, N- (2-aminosulfonylethyl) methacrylamid Methacrylic acid amides and the like, and acrylamides having the same substituents as above, also, o- aminosulfonylphenyl off methacrylate, m- aminosulfonylphenyl methacrylate, p- aminosulfonylphenyl methacrylate, 1
Unsaturated sulfonamides such as methacrylates such as-(3-aminosulfonylnaphthyl) methacrylate and acrylates having the same substituents as described above (15) N- (2- (methacryloyloxy) -ethyl) Unsaturated monomers having a crosslinkable group in the side chain, such as -2,3-dimethylmaleimide and vinyl cinnamate; Further, a monomer copolymerizable with the above monomer may be copolymerized. (16) Phenol resins described in U.S. Pat. No. 3,751,257 and polyvinyl acetal resins such as polyvinyl formal resins and polyvinyl butyral resins. (17) Tokiko Sho 54 made of alkali-soluble polyurethane
-19773, JP-A-57-904747 and JP-A-57-904747.
-182437, 62-58242, 62-1
No. 23452, No. 62-123453, No. 63-11
Polymer compounds described in JP-A No. 3450 and JP-A-2-14642. If necessary, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, an epoxy resin, a novolak resin, a natural resin, or the like may be added to the copolymer.

The photosensitive composition used for the support of the present invention may further contain a dye for the purpose of obtaining a visible image by exposure and a visible image after development. Examples of the pigment include Victoria Pureable-BOH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue # 603 (manufactured by Orient Chemical Industries), Patent Pure Blue (manufactured by Sumitomo Sangoku Chemical Co., Ltd.), crystal violet, brilliant green, ethyl violet, Trimethyl represented by methyl violet, methyl green, erythrosin B, basic fuchsin, malachite green, oil red, m-cresol purple, rhodamine B, auramine, 4-p-diethylaminophenyliminaphthoquinone, cyano-p-diethylaminophenylacetanilide and the like Color tone of phenylmethane, diphenylmethane, oxazine, xanthene, iminonaphthoquinone, azomethine or anthraquinone dyes from colored to colorless or different It mentioned as examples of discoloring agents changing. 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, 1,2,3-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-
Primary or secondary spherical arylamine dyes represented by anilinonaphthylmethane and p, p ', p "-triaminotriphenylmethane. Triphenylmethane dyes and diphenylmethane dyes are particularly preferred. It is effectively used, and is more preferably a triphenylmethane dye, particularly Victoria Pure Blue BOH.

Various additives can be further added to the photosensitive composition used in the present invention. For example, alkyl ethers (eg, ethyl cellulose, methyl cellulose) for improving coatability, fluorinated surfactants, nonionic surfactants (especially fluorinated surfactants are preferable), flexibility of the coating film, and resistance to Plasticizers for imparting abrasion properties (for example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate,
Tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers and polymers of acrylic acid or methacrylic acid, of which tricresyl phosphate is particularly preferred), and a feeling for improving the oil sensitivity of the image area. Fatty agent (for example, JP-A-55-
No. 527, a half-esterified product of a styrene-maleic anhydride copolymer with an alcohol, a novolak resin such as pt-butylphenol-formaldehyde resin, a 50% fatty acid ester of p-hydroxystyrene, etc.), a stabilizer {for example, Phosphoric acid, phosphorous acid, organic acids (citric acid, oxalic acid, dipicolinic acid, benzenesulfonic acid, naphthalenesulfonic acid, sulfosalicylic acid, 4-methoxy-2-hydroxybenzophenone-5-sulfonic acid, tartaric acid, etc.)｝, development Accelerators (eg, higher alcohols, acid anhydrides, etc.) are preferably used.

In order to provide the above-mentioned photosensitive composition on a support, a predetermined amount of a photosensitive diazo resin, a lipophilic polymer compound and, if necessary, various additives are added to a suitable solvent (methyl cellosolve, ethyl Cellosolve, dimethoxyethane, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, 1-methoxy-2-propanol, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethylformamide, dimethylacetamide, cyclohexanone, dioxane,
Tetrahydrofuran, methyl lactate, ethyl lactate, ethylene dichloride, dimethyl sulfoxide, water, or a mixture thereof) to prepare a coating solution of the photosensitive composition, and then apply the solution on a support and dry it. The solvent used may be a single solvent, but is more preferably a mixture of a high boiling solvent such as methyl cellosolve, 1-methoxy-2-propanol and methyl lactate and a low boiling solvent such as methanol and methyl ethyl ketone. The solid concentration of the photosensitive composition at the time of application is desirably in the range of 1 to 50% by weight. In this case, the coating amount of the photosensitive composition may be about 0.2 to 10 g / m ² (dry weight), more preferably 0.5 to 3 g / m ² .

[III] When a photosensitive layer containing a photodimerizable photosensitive composition and a photopolymerizable photosensitive composition is provided: As the photodimerizable photosensitive composition, a maleimide group, a cinnamyl group, a cinnamoyl group, a cinnamylidene group, Polymers having a cinnamylidene acetyl group or chalcone group in the side chain or main chain are mentioned. As a polymer having a maleimide group in the side chain, JP-A-52-988 (corresponding to US Pat. No. 4,079,041) ) Gazette and German Patent No. 2,6
26,769, EP 21,019
And EP 3,552, and Die Angewandte Makromolekulare Chemie 115 (1).
983), pages 163 to 181 and JP-A-49-128991 and JP-A-49-12891.
No. 992, No. 49-128993, No. 50-5376
No. 50-5377, No. 50-5379, No. 50
No.-5378, No.50-5380, No.53-5298
Nos. 53-5299, 53-5300, 50
No. -50107, No. 51-47940, No. 52-13
No. 907, No. 50-45076, No. 52-12170
Nos. 0, 50-10884 and 50-45087, German Patent Nos. 2,349,948 and 2,61.
No. 6,276, and the like. In order to make these polymers soluble or swellable in alkaline water, carboxylic acid / sulfonic acid, phosphoric acid, phosphonic acid, their alkali metal salts and ammonium salts, and pKa that dissociates in alkaline water are 6%. It is useful to use the polymer containing from 12 to 12 acid groups in the polymer. If necessary, the above 13 kinds of monomers having an acid group and a monomer having a maleimide group can be copolymerized.

The acid value of the maleimide polymer having an acid group is preferably in the range of 30 to 300. Among the polymers having such an acid value, Die Angewandte Makromolekum
lare Chemie) 128 (1984), pp. 71-91, a copolymer of N- [2- (methacryloyloxy) ethyl] -2,3-dimethylmaleimide and methacrylic acid or acrylic acid. Useful.
Furthermore, by synthesizing the vinyl monomer of the third component at the time of synthesizing the copolymer, a multi-component copolymer suitable for the purpose can be easily synthesized. For example, by using an alkyl methacrylate or an alkyl acrylate whose homopolymer has a glass transition point of room temperature or lower as the vinyl monomer of the third component, flexibility can be given to the copolymer.

US Pat. No. 3,030,208 and US Pat. No. 3,030,208 are examples of optically overseas polymers having a cinnamyl group, a cinnamoyl group, a cinnamylidene group, a cinnamylidene acetyl group or a chalcone group in a side chain or a main chain. Application 7
There are photosensitive polyesters described in JP-A-09-496 and JP-A-828-455. The followings are examples of those obtained by solubilizing these photocrosslinkable polymers with alkaline water. That is, JP-A-60-191
Photopolymers such as those described in JP-A-244-244 can be mentioned. Further, Japanese Patent Application Laid-Open No. 62-17572
9, JP-A-62-175730, JP-A-63-25
No. 443, JP-A-63-218944 and JP-A-63-218944.
And the photosensitive polymer described in each publication of JP-A-218945. A sensitizer can be used in the photosensitive layer containing these compounds. Examples of such a sensitizer include benzophenone derivatives, benzanthrone derivatives, quinones, aromatic nitro compounds, naphthothiazoline derivatives, and benzothiazoline derivatives. Thioxanthones, naphthothiazole derivatives, ketocoumarin compounds, benzothiazole derivatives, naphthofuranone compounds, beryllium salts, thiavirylium salts, and the like.
In such a photosensitive layer, if necessary, chlorinated polyethylene, chlorinated polypropylene, polyacrylate alkyl ester, acrylate alkyl ester, acrylonitrile, vinyl chloride, styrene, a copolymer with at least one of monomers such as butadiene, Binders such as polyamide, methyl cellulose, polyvinyl formal, polyvinyl butyral, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, dibutyl phthalate,
Plasticizers such as dialkyl phthalate such as dihexyl phthalate, oligoethylene glycol alkyl ester, and phosphate ester can be used.
Further, for the purpose of coloring the photosensitive layer, a dye or a pigment, or a substance to which a pH supporting agent or the like is added as a printing-out agent is also preferable.

Examples of the photopolymerizable photosensitive composition include unsaturated carboxylic acids and salts thereof, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds, and amides of unsaturated carboxylic acids and aliphatic polyhydric amine compounds. And the like. Examples of photopolymerization initiators include vicinal polytaketaldonyl compounds, α-carbonyl compounds, acyloin ethers, α-
Acyloin compound substituted at the hydrocarbon position, polynuclear quinone compound, triallylimidazole dimer / p
A combination of -aminophenyl ketone, a benzothiazole compound, a trihalomethyl-s-triazine compound,
Acridine and phenazine compounds, oxadiazole compounds and the like are included. Together with these, the polymer capable of forming a film in an alkali water-soluble or swellable form is benzyl (meth) acrylate / (meth) acrylic acid / necessary. Other addition polymerizable vinyl monomer copolymers, methacrylic acid / methyl methacrylate (or methacrylic acid ester) copolymers, and maleic anhydride copolymers added with pentaerythritol triacrylate by half esterification according to And acidic vinyl copolymers.

[IV] Electrophotographic Photosensitive Layer For example, a ZnO photosensitive layer disclosed in US Pat. No. 3,001,872 can be used. Also, JP-A-56-161550 and JP-A-60-186847
And a photosensitive layer using an electrophotographic photoreceptor described in JP-A-61-238063 or the like.
The amount of the photosensitive layer provided on the support is about 0.1 to about 7 g / m ² , preferably 0.5 to 4 g, by dry weight after coating.
/ M ² .

In the method for producing a lithographic printing plate support according to the method of the present invention, in order to enhance the adhesion between the support and the photosensitive layer, to prevent the photosensitive layer from remaining after development, or to prevent halation. For the purpose of the above, an intermediate layer may be provided as necessary. In order to improve the adhesion, the intermediate layer is generally made of a diazo resin or a phosphoric acid compound, an amino compound, a carboxylic acid compound or the like which adsorbs to aluminum, for example. The intermediate layer made of a substance having high solubility so that the photosensitive layer does not remain after development is generally made of a polymer having good solubility or a water-soluble polymer. In order to further prevent halation, the intermediate layer generally contains a dye or a UV absorber. The thickness of the intermediate layer is arbitrary, and must be a thickness capable of performing a uniform bond-forming reaction with the upper photosensitive layer upon exposure. Usually, about 1-100 mg / m ^{2 as} a dry solid
Is good, and 5 to 40 mg / m ² is particularly good.

On the coated photosensitive layer, a mat layer composed of protrusions provided independently of each other can be provided. The purpose of the mat layer is to improve the vacuum adhesion between the negative image film and the photosensitive lithographic printing plate in contact exposure, thereby shortening the vacuuming time and preventing the collapse of minute dots during exposure due to poor adhesion. That is.
Japanese Patent Application Laid-Open No. 55-12974 discloses a method of applying a mat layer.
JP-A-58-182636, a method of spraying and drying polymer-containing water described in JP-A-58-182636, and the like. It is desirable that the mat layer itself be dissolved in an aqueous alkaline developer containing substantially no organic solvent, or be removable by this.

After the photosensitive lithographic printing plate prepared as described above is exposed to an image, a resin image is formed by a process including development by a conventional method. For example, in the case of a photosensitive lithographic printing plate having the photosensitive layer of the above [I], after exposing the image, it is exposed to light by developing with an aqueous alkali solution as described in US Pat. No. 4,259,434. A part of the lithographic printing plate is obtained by removing the portion, and in the case of a photosensitive lithographic printing plate having the photosensitive layer of [II], after image exposure, the lithographic printing plate is described in US Pat. No. 4,186,006. With a developing solution as described above, the photosensitive layer in the unexposed area is removed by development to obtain a lithographic printing plate. Also, Japanese Unexamined Patent Publication No.
No. 84241, JP-A-57-192952, and JP-A-62-24263, which use an aqueous alkaline developer composition used for developing a positive-working lithographic printing plate. You can also.

[0042]

The lithographic printing plate support of the present invention will be described in more detail with reference to the following Examples and Comparative Examples. However, the present invention is not limited by the examples. Examples (1-4) and Comparative Examples (1-4) JIS1050 material was mechanically grained at a rotation speed of 250 rpm with an apparatus described in Japanese Patent Publication No. 500047/1985, and the strength of the hairs and polishing were measured. The desired physical property values were obtained by changing the material particle size. Thereafter, the substrate was washed with water and subjected to a first chemical etching. This first etching is performed at a caustic soda concentration of 2%.
It was kept constant at 5%, the liquid temperature was 55 ° C., and the processing time was adjusted so that the etching amount was 10 g / m ² . Thereafter, washing with water and removal of smut were performed, and according to the power supply waveform described in JP-A-3-79799, the nitric acid concentration was 10 g / liter,
Electrochemical surface roughening was performed under the conditions shown in Table 1 with an aluminum concentration of 5 g / liter and a solution temperature of the nitric acid solution and an amount of anodic electricity. After washing with water, a second chemical etching was performed. The concentration of caustic soda was set to the same conditions as in the first chemical etching, the liquid temperature was 40 ° C., and the processing time was 1 etching.
g / m ² . Thereafter, washing with water and desmutting were performed to form an anodic oxide film at a sulfuric acid concentration of 120 g / liter and a liquid temperature of 45 ° C. so that the amount of the film became 3.0 g / m ² .

[0043]

[Table 1]

Thereafter, observation was performed by SEM (magnification × 5000). Table 2 shows the state of pit formation observed.

[0045]

[Table 2]

On the aluminum plate thus prepared, the following composition was applied so that the coating weight after drying was 2.0 g / m ² , and a photosensitive layer was provided. And (Composition of photosensitive layer) Ester compound of naphthoquinone-1,2-diazido-5-sulfonyl chloride with pyrogallol, acetone resin (as described in Example 1 of U.S. Pat. No. 3,635,709) 0.075 g-Cresol novolak resin 2.00 g ・ Oil Blue 603 (Orient Chemical) 0.04 g ・ Ethylene dichloride 16 g ・ 2-methoxyethyl acetate 12 g

The results of confirming the printing performance of each photosensitive lithographic printing plate are also shown in Table 2.

As described above, the support for a lithographic printing plate according to the present invention is characterized in that the contact state of the formed pits after the chemical roughening treatment and the chemical etching treatment is defined. It is possible to provide a lithographic printing plate in which various characteristics such as stain resistance, printing performance, printing durability, and the like are remarkably improved.

Claims (1)

[Claims] 1. A lithographic printing plate support obtained by subjecting a surface of an aluminum plate or an aluminum alloy plate to a surface roughening treatment, which is formed by performing a chemical etching treatment subsequent to an electrochemical surface roughening treatment. When the pits observed are observed with an electron microscope, the number of pits directly in contact with the periphery of a certain pit without a flat portion is 4 to 8 on average, and the number of pits directly in contact is 3 A lithographic printing plate support, characterized in that the proportion of pits of not more than 20% is 20% or less, and the proportion of pits of 10 or more directly contacting pits is 20% or less.