JPS6038195A - Support for planographic printing plate - Google Patents

Abstract

PURPOSE:To provide the titled support excellent in treating chemicals resistance and printing durability, having a wide tolerant degree in a developing method and capable of performing the printing of a large number of sheets without generating staining, constituted by using an iron material, of which the surface is roughened to specific roughness, as a base material. CONSTITUTION:In a support for a planographic printing plate using an iron material as a base material, the material, wherein the peak count (S1, S2) ratio in the cutting depth of 2.0mum of surface roughness profile R threof is S2/S1=0.05- 5.0, pref., 0.8-1.0 and a vary count (T1, T2) ratio is T2/T1=1.1-5.0, pref., 1.5- 2.7, is used as the above mentioned base material. Furthermore, it is pref. that the relation of S2<=S1 is formed and the values of S2 and S1 are near while the relation of S2/S1 and T2/T1 is pref. S2/S1<T2/T1. In addition, it is most pref. that the center line average roughness Ra of the surface of the base material is 0.4-1.5mum from the aspect of water holdability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a support for a lithographic printing plate based on iron material,
More specifically, the present invention relates to a lithographic printing plate support having improved chemical resistance and printing durability and having an iron material with a roughened surface as a base material.

Prior Art The above support is made of iron because it has high physical strength as a support for planographic printing plates, and is less likely to cause so-called "W plate breakage", which occurs when the cylinder trap of an offset printing machine is attached to a cylinder trap, which is caused by cutting at an acute angle. is known to be used as a base material.

That is, a support for a lithographic printing plate having an electrodeposited PM layer on an iron material with a flat outer surface and substantially no sharp protrusion angles is disclosed in Japanese Patent Application Publication No. R@55-145193, and Japanese Patent Application Publication No. 55-145193 discloses Japanese Patent No. 57-138639 describes a support having an electrodeposited chromium layer on an iron plate, which has diffusion cracks and holes, and in which chromium is exposed in the form of crystals. However, these supports have shallow grains and are made only of fine crystals of chromium, so when applied to lithographic printing plates, their water retention is insufficient and they tend to smudge during printing. (Furthermore, the photosensitive layer on the surface was prone to scratches.) Scratches generated during plate making were likely to be reproduced on printed matter during printing.

On the other hand, as a support for a lithographic printing plate using a roughened iron material as a base material, for example, Japanese Patent Laid-Open No. 56-64597,
-130395, 56-130396 and 56
No. 150592 describes a method using iron material manufactured by electroforming. These supports have improved to some extent the drawbacks of the supports using flat iron as the base material, but lithographic printing plates using these supports have problems with adhesion between the photosensitive layer and the support in the image area. The print area may be soaked in various processing chemicals used for removing dirt or gumming from printing strips, dampening water containing alcohol, or the print may be damaged during long-term printing. There are drawbacks such as some peeling of the line parts and insufficient printing durability, and problems during development.
There is a problem that damage to the image area is likely to occur when developing by so-called 11-hand development 11, in which a sponge is soaked with developer and rubbed against the plate without using an automatic developing machine, in other words, the tolerance of the developing method is low. It has the problem of being narrow.

Purpose of the Invention - C The purpose of the present invention is to have excellent treatment chemical resistance and printing durability,
Another object of the present invention is to provide a support for a lithographic printing plate which has a wide latitude in developing methods and allows printing on a large number of sheets without staining.

Another object of the present invention is to provide a photosensitive lithographic printing plate which has excellent processing chemical resistance and printing durability, is excellent in the latitude of the developing method, and is capable of printing a large number of sheets without staining. .

Still other objects of the present invention will become apparent from the description in part 1.

As a result of extensive research, the present inventors have discovered that the above object can be achieved by a lithographic printing plate support having the following structure.

That is, the lithographic printing plate support of the present invention is a lithographic printing plate support of 1" with an iron material as a base material, and has a surface roughness profile R with a peak color of 71 mm at a cutting depth of 2.0 μm.
The ratio of (St y S2) is 82/s, = 0.0
5 to 5.0, and the ratio of Barry count (T, , T2) is T2/TI=1.1-5.0.

The present invention will be explained in more detail.

In the planographic printing plate support of the present invention, an iron material is used as a base material, and examples of the iron material include pure wheat as well as alloys of iron and other elements. Examples of other elements that form alloys with iron include carbon, manganese, and nickel.

The alloy specifically refers to carbon steel [carbon (0.04~
1.7%) and iron], cast iron with a higher carbon content than carbon steel, and special steels containing other elements (e.g. manganese, nickel, chromium, cobalt, tungsten, molybdenum, etc.) (e.g. manganese steel, (2) KEL steel, chromium steel, nickel-chromium steel, etc.). The carbon steel mentioned above includes extremely mild steel (0.25% carbon or less), mild steel (0.25% carbon or less),
~0.5%), hard steel (carbon 0.5-1.0%), extra hard @
(carbon 1.0% or more) is included.

When classified by structure, examples include fluorite, martensite, austenite, sorbite, troostite, nokurite, and cementite.

As the iron material according to the present invention, a plate-shaped (including foil-shaped) iron material manufactured by a rolling method, an electroforming method, or the like can be used.

In the present invention, the surface roughness profile R of the base material
is defined by the M-system shown in the German standard DIN 4768 when surface roughness is measured using a stylus type surface roughness meter, and the difference between the traced profile and the center line is measured with the center line as the reference. A curve expressed as a line.

Furthermore, the peak count (S, t st
) is the number of peaks per inch that exceed the cutting line set parallel to the center line in the roughness profile R, and SI is the number of peaks per inch that exceed the cutting line set parallel to the center line, as shown in Figure 1. S2 is the number of peaks exceeding 2 (the number of X marks in FIG. 1), and S2 is the number of peaks exceeding the cutting line 3 below the center line (the number of * marks in FIG. 1).

Furthermore, the burry count T in the present invention is such that in the roughness profile R, as shown in FIG. It is the number of exceeding peaks per inch (the number of ten marks in Fig. 2), and the burry count Tz is the number of peaks that exceed the upper cutting line 2 in the roughness profile R, as shown in Fig. 3. The number of peaks per inch (number of O marks in FIG. 3) exceeding the center line is the number of peaks that exceed the center line.

Note that the upper cutting line and the lower cutting line are installed symmetrically with respect to the center line in both the peak count and the burry count, and the distance from each center line is the cutting depth C. ). In the present invention, this cutting depth Q is 2.0 μm.

The st/sl of the iron material related to the present invention is 0.05 to 5.0
and preferably 0.1 to 3. Furthermore, s2≦s
It is preferable that the value of S and 81 be close to each other, particularly preferably in the range of 0.8 to 1.0. or,
'rz/'r of the iron material according to the present invention is 1.1 to 5.
0, preferably 1.1 to 3, particularly preferably 1
．． 5 to 2.7. Furthermore, st/S, and 'rt/
The relationship 'r is preferably S2/81<T2/TI.

When measuring the peak count and burry count, at least 10 different locations on the sample surface are measured, and the average value is taken as the measured value. The measured length is 4.0
The thickness is preferably about μm.

In addition, the center line average roughness Ra) of the base material surface related to the present invention
is preferably 0.1 to 3 μm, more preferably 0.
．． The thickness is 3 to 2 μm, and most preferably 0.4 to 1.5 μm from the viewpoint of water retention.

Here, the center line average roughness (Ra) is defined by the German standard DI.
As shown in N 4768, it is the arithmetic mean of the absolute value of the distance from the center line of the roughness profile to each point on the profile, and the center axis in the horizontal direction is the X axis, and the vertical & Y axes are the roughness. When a point on the profile is expressed as (z, y), the Ra value calculated by the following formula for the measurement length em is expressed in microns.

The above values of peak count (Sl, 82), burry count ('r+, Tt), and center line average roughness (Ra) are as follows:
For example, it can be measured using a Perthometer 85P manufactured by Perthen.

Next, methods for forming the surface shape according to the present invention include, for example, a mechanical method and an electrolytic etching method. Examples of mechanical methods include ball polishing,
Examples include a brush polishing method and a polishing method using liquid honing. Examples of the electrolytic etching method include etching using a solution containing phosphoric acid, sulfuric acid, perchloric acid, hydrochloric acid, nitric acid, pyrophosphoric acid, hydrofluoric acid, and the like.

In producing the roughened iron material, the various methods described above can be selected and used as appropriate depending on the composition of the iron material. Particularly preferred in the present invention is an electrolytic etching method.

Electrolytic etching is carried out in a bath containing one or more of the above-mentioned inorganic acids. Among these, preferred are sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, or a mixture of two or more of these, and particularly preferred is a bath containing sulfuric acid as a main component. In addition, organic substances such as alcohol and acetic anhydride, inorganic substances such as potassium dichromate, colloids such as gelatin and starch, glycerin, other viscous substances, and surfactants may be added to the bath as additives. I can do it. These additives may be used alone or in combination of two or more. The electrolytic etching bath is prepared by adding the above-mentioned acids and, if necessary, the above-mentioned additives to water.

The bath temperature during electrolytic etching is preferably in the range of 06 DEG to 100 DEG C., and the current density is preferably in the range of 10 to 200 A/dm''.

As pretreatment for electrolytic etching, mechanical polishing, degreasing, pickling, etc. are applied as necessary. Examples of the degreasing treatment include solvent cleaning, alkaline boiling, and electrolytic treatment using an alkaline bath.

Examples of the alkali used in the degreasing treatment include sodium hydroxide, sodium carbonate, sodium silicate, and sodium phosphate, and a surfactant may also be added.

As a post-treatment during electrolytic etching, a method of washing with water, washing with dilute acid, neutralizing with alkali, and washing with water is used as necessary. Moreover, if etching becomes excessive, smut will adhere to the iron surface, so a desmut treatment can be applied as necessary. Examples of the desmut treatment include preliminary cleaning, mechanical treatment such as tampling or steam blasting, anodic cleaning with an alkaline cleaner, descaling with hydrochloric acid, and smut removal treatment.

In the present invention, the term ``n'' based on an iron material means that the iron material may be used as it is as a support for a lithographic printing plate, or the iron material may be subjected to surface treatment, lining, or other treatments.

The above-mentioned roughened iron material has the above-mentioned peak count ratio B
J Bs and parry count ratio T! / TI, more preferably centerline average roughness Ra. Various surface treatments may be applied as long as the surface shape of the plate side of the surface treatment layer provided by surface treatment is within the range described above.

Examples of surface treatments for Tsumugi include zinc, chlorine, copper,
Methods of plating tin, chromium, etc. by electroplating, chemical plating, hot-dip plating, etc., film formation methods using phosphates, succinates, chromates, etc. (methods by electrolysis may also be used)
, a method of vapor depositing aluminum 2m, etc. Further, two or more surface treatments may be performed sequentially.

If the roughened iron material is thin like foil, a metal plate, plasti, Kufilm, etc. may be attached to the back surface directly or via an adhesive layer.

Various shapes can be applied to the layer formed by the above-mentioned surface treatment (surface treatment layer), for example, one in which there are essentially no protrusions on the surface, that is, the thickness of the surface treatment layer is substantially uniform. On the surface, there are pores, cracks, pores, and crystalline protrusions. Things can be mentioned. In the present invention, a preferable surface treatment layer has protrusions on the surface.

A preferable shape of the protrusions is, for example, an agglomerate of curved, slightly agglomerated, agglomerated agglomerated particles with small round protrusions, and the aggregation has corners. Substantially non-existent 5 For example, JP-A-55-14519
Those described in Publication No. 3, as well as angular crystals and/or
or aggregates thereof, such as those described in Japanese Patent Application No. 105724/1983 filed by the present applicant on June 18, 1982 (title of the invention: "Support for lithographic printing plates"). The surface treatment layer 'C is particularly composed of angular crystalline rattan and/or
Or, those having Iil aggregates are preferable because they have better printing durability and developability latitude of lithographic printing plates. The angular crystalline material is preferably plate-shaped or polyhedral, for example cubic.

The plate-like crystalline material is preferably a polygonal, mainly hexagonal plate, and the diameter of the polygonal surface is 0.3 to 5 t.
m(1) is preferable, and the thickness is 0.01-0.8 μm
Preferably. As the polyhedral crystalline rattan, one having a diameter of 0.05 to 5 μm is particularly preferable. The projected area ratio of the above-mentioned protrusions is preferably 20% or more. Here,
The projected area ratio is a projection in a direction perpendicular to the surface of the support of the present invention, that is, an orthogonal projection, and the area ratio can be measured using a photomicrograph or the like.

Further, the protrusions preferably protrude from the surface by 0.05 to 5 μm, particularly preferably by 0.2 to 4 μm.

The thickness of the surface treatment layer is 0. O1-5 rim is preferred, particularly 0.05-3 μm.

This film thickness can be determined as an average value by quantifying it from a calibration curve prepared in advance using a layer of known reference film thickness using fluorescent X-ray analysis or the like.

In the present invention, the surface treatment layer is preferably a chromium-based layer, such as a chromium electrodeposited layer.

The elemental composition of the chromium electrodeposited layer consists essentially of chromium and rR, and elemental analysis in the depth direction shows that it is composed of chromium oxide (this oxide also includes hydrates) and metallic chromium. It is judged that the proportion of metallic chromium increases as the depth increases. Examples of chromium oxides include divalent, trivalent, and hexavalent chromium oxides, but mainly trivalent chromium oxides.

Next, a typical method of providing a chromium electrodeposition layer having protrusions will be described.

The chromium electrodeposited layer, which has rounded protrusions consisting of agglomerated aggregates of slightly agglomerated curved, slightly agglomerated curved cylindrical particles with small round protrusions, is deposited on iron material in a granulation tank containing pyfluoride. After soaking Cra+/B O,! −
It can be produced by electroplating for at least a blade second in a plating bath containing water, chromic anhydride and sulfuric acid in amounts that maintain the ratio of 75 to 180.

Specific conditions are described in detail in JP-A-55-145393.

A preferred method for providing a chromium electrodeposited layer having protrusions that are angular crystals and/or aggregates thereof on a steel material is, for example, by cooling or heating an electrolytic solution to adjust the temperature of the solution.
It performs electrolytic treatment.

This electrolytic solution 1 is an electrodeposited chromium layer forming solution for forming an electrodeposited chromium layer according to the present invention on the surface of an iron material.

Table 1 [Solution Solution l Chromic anhydride (Cr, Os) Zoo ~500,!
i' barium compound i -1of! Fluorides, such as hydrogen fluoride ()IF) O~20F! glass
Acid 0ν10g Acetic Acid 0-1g Add water to make Ig.

Table 2 Electrolysis conditions l DC voltage 5 to 15 (b) Current density 5 to 50 A/dm” Liquid temperature 0 to 60°C 2 Cathode Iron material film Electrode Lead electrode Area ratio of cathode to anode l: l to l: 1 .5 Processing time: 2 to 6 minutes This method was published by the applicant on June 18, 1982.
It is described in detail in Japanese Patent Application No. 57-105723 (title of the invention: ``Method for manufacturing a support for a lithographic printing plate'') filed on 1987-105723.

Another preferred method for providing a chromium electrodeposited layer having protrusions that are angular crystals and/or aggregates thereof on a steel material is [Cr11+] / [BO,2-] (here [
(r6+] represents the ion concentration of Or'10, and [5o--ko represents the ion concentration of so,"-) is 75 to 18
This is a method of electrolytically treating the iron material in a plating solution with a current density of less than 40'C and a temperature of less than 40'C for a period of time or more.In the plating solution, [ Cra
+3 is preferably α2 to 4.5 mol/e, and 0.5 to 3
Especially preferred is mol/e. [3Q,! -ko is 0.01~
0.046 mol/e is preferable, 0.015 to 0.03
Moles are particularly preferred.

Chromic anhydride is preferred as the Cr' source, and SO
/- Sulfuric acid is preferred as the source.

Ratio of hexavalent ROM ion concentration to sulfate ion concentration ([Cr6
+]/[so4''-]) is 75 to 180, preferably in the range of 80 to 130.The plating solution used in the present invention may also contain fluorine compounds, strontium compounds, etc. I can do it.

Examples of the elementary compounds include ammonium fluoride, sodium fluorosilicide, hydrofluorosilicic acid, chromium fluorosilicide, and the like.

Strontium compounds include strontium sulfate,
Examples include strontium chromate. The amount of the fluorine compound added is 0.5 to 10 g/e, and the amount of the strontium compound added is 3 to 20 microliters.

As for the electrolytic conditions, the current density is 100 A/dmt or less, preferably in the range of 10 to 304/dm''.

Furthermore, the plating bath temperature is preferably in the range of 0 to 40°C, particularly preferably in the range of 10 to 30°C. Regarding the relationship between bath temperature and current density, it is preferable that when the bath temperature is high, the current density is high, and when the bath temperature is low, the current density is also low. Preferably, it is a combination of a bath temperature of n±4°C and a current density of 15 to 201 y'dm.The details of this method are described in the specification of Japanese Patent Application No. 114642/1987 filed in June 1982 by the present applicant. (Name of the invention “Method for manufacturing a support for lithographic printing plates”)
is described in detail.

Next, porous chromium plating that can be applied to the chromium electrodeposited layer will be described. Porous chromium plating is obtained by performing reverse electric treatment and electrolytic etching after chromium plating. Usually 1-2%, 30-40 vdm” in a sulfuric acid bath,
After plating by performing reverse electrolysis for 1 to 2 minutes or in a plating bath,
(9) to 60 A/dm with reverse current! , 50~ω℃, 5~1
Perform etching for 0 minutes.

It is also possible to perform an appropriate post-treatment after the step of providing the chromium electrodeposition layer (main treatment).

Preferred methods for the post-treatment step include the following method.

After washing the iron material having the chromium electrodeposition layer with an acid or alkaline aqueous solution as required, the surface is treated with a surface treatment liquid of a permanganate aqueous solution.

Preferred permanganates used in the above surface treatment solution include lithium permanganate, sodium permanganate, potassium permanganate, rubidium permanganate, calcium permanganate, and barium permanganate. There is. The concentration of permanganate in the surface treatment liquid used is preferably 0.05 to 10% by weight, particularly preferably 1.0 to 5.0% by weight. The temperature of the treatment liquid is preferably 0 to 80°C, particularly preferably 50°C to 50'C. This method was described by the applicant in June 1982.
The method is described in more detail in Japanese Patent Application No. 105725/1983 (title of the invention: ``Method for manufacturing a support for a lithographic printing plate'') dated May 18, 1983.

Another preferred method for the post-treatment step is the following method.

After washing the iron material with the chromium electrodeposited layer with an acid or alkaline aqueous solution as necessary, water-soluble polymer compounds, as well as calcium, magnesium, zinc, strontium, cobalt, manganese, nickel, and silicon are added to the iron material. The surface is treated with a surface treatment solution containing at least one of the following salts.

The water-soluble polymer compound preferably has a solubility of 0.01% or more. Preferred water-soluble polymer compounds include, for example, gum arabic, starch, dextrin, sodium alginate, natural polymer compounds such as gelatin, water-soluble cellulose compounds m, examples tjf, water-soluble salts of carboxyalkylcellulose (alkyl is methyl , ethyl, propyl, etc.), alkylcelluloses such as methylcellulose, hydroxymethylcellulose,
Hydroxyethyl cellulose, hydroxyglobil cellulose, etc., polyacrylic acid or its water-soluble salt, polymethacrylic acid or its water-soluble salt, acrylic acid copolymer or its water-soluble salt, methacrylic acid copolymer or its water-soluble salt, styrene - Synthetic polymeric compounds such as maleic anhydride copolymer, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, etc. Water-soluble salts of the polymeric compounds include sodium salts and potassium salts.

The above various water-soluble polymer compounds may be used alone or in combination of two or more. Among water-soluble polymer compounds, natural polymer compounds such as starch and dextrin and water-soluble cellulose compounds are preferred. Also, the molecular weight is 500
~i, ooo, ooo are preferably used.

Water-soluble salts used with water-soluble polymer compounds are preferably those having a solubility of 0.01% or more, particularly inorganic or organic acids such as calcium, magnesium, zinc, barium, strontium, cobalt, manganese, and nickel. and silicon salts. Representative organic acid salts are salts of carboxylic acids such as acetic acid, propionic acid, butyric acid, cono-phosphoric acid, benzoic acid, salicylic acid and acetylacetonate. Typical inorganic acid salts are chloride,
Bromide, chlorate, bromate, iodide, iodate, nitrate, sulfate and phosphate. The water-soluble salts may be used alone or in combination of two or more.

As water-soluble salts, organic acid salts are particularly preferred, and magnesium, magnesium, barium and zinc salts are particularly preferred. The coating weight of the layer containing the water-soluble polymer compound and water-soluble salt formed by this method is 0.001 to
l 19/dm2 is preferred, especially 0.05 to 0.5 m
9/dm" is preferred. This method and the film formed are described in Japanese Patent Application No. 105726/1983 filed by the present applicant on June 18, 1981 (title of the invention "Support for lithographic printing plate and The manufacturing method is described in more detail in "Manufacturing Method".

Due to its unique surface shape, the lithographic printing plate support of the present invention has many polymeric compounds on the lipophilic surface such as the photosensitive layer provided thereon when used as a photosensitive lithographic printing plate. It has excellent adhesion to the layers, has extremely good durability of the printed area against processing chemicals used during printing, and has good printing durability. In addition, since the development method has a wide latitude, image areas are less likely to be lost even in 11-hand development (1), which is an excessively abrasive development process.

Furthermore, it has excellent water retention properties and is resistant to staining during printing.

In addition, the image area on the surface is not susceptible to scratches, and scratches caused during plate making are rarely reproduced in printed matter during printing.

FIG. 4 is an electron micrograph of the surface of the iron material of the present invention which has been electrolytically etched in a sulfuric acid bath. 5 to 7 are electron micrographs of the surface of a support according to the present invention in which a chromium electrodeposition layer having protrusions of various shapes is provided on the iron material of FIG. 4. FIG. 8 shows an electron micrograph of the surface of an iron material whose peak count and burry count are outside the range of the present invention.

A photosensitive lithographic printing plate can be produced by coating the photosensitive composition on the support of the present invention using, for example, an organic solvent.

The photosensitive composition contains a photosensitive substance as an essential component, and the photosensitive substance includes those that cause a difference in the solubility of the photosensitive composition layer in the developer depending on exposure C, and those that cause differences between molecules before and after exposure. It is possible to use a material that causes a difference in the adhesive strength of the photosensitive composition layer, and a material that causes a difference in the affinity of the photosensitive composition layer for water and oil upon exposure.

Typical examples will be explained below. First, quinonediazide-type positive photosensitive substrates such as conventionally known 0-naphthoquinonediazide compounds are mentioned.

0-quinonediazide compounds are compounds having at least one 0-quinonediazide group, preferably an 0-benzoquinonediazide group or an 0-naphthoquinonediazide group;
Known compounds of various structures, e.g. J. Kosar
Written by 'i-Light-8ensistive System
msj (John Wllley & 5ons, In
c, published in 1965), pages 339 to 353. Particularly suitable are esters of various hydroxyl compounds and 0-naphthoquinonediazide sulfonic acid. Preferred hydroxyl compounds include condensation resins of phenols and carbonyl group-containing compounds, particularly resins obtained by condensation in the presence of an acidic catalyst. The phenols include phenol,
Examples include resorcinol, cresol, pyrogallol, etc.
Examples of the carbonyl group-containing compound -C include aldehydes such as formaldehyde and benzaldehyde, and ketones such as acetone.

Particularly preferred are 7-nol formaldehyde resin, creso-1 formaldehyde resin, pyrogallol acetone resin, and resorcinol benzaldehyde resin.

Typical specific examples of 0-quinonediazide compounds include:
Esters of benzoquinone-(1,2)-diazide sulfonyl chloride or naphthoquinone-(1°2)-diazide sulfonyl chloride with phenol formaldehyde resin or Frazi A. formaldehyde resin, U.S. Pat. No. 3,635,709. Naphthoquinone-(1,2)-diazide sulfonyl chloride and pyrogallol-acetone resin sulfuric acid ester described in the specification, naphthoquinone-(1,2)-diazide sulfonyl chloride described in JP-A-56-1044; 2)-Diazide-(2)-
Condensate of 5-sulfonyl chloride and resorcin-benzaldehyde resin, naphthoquinone-(ls2)-diazide-(2)-5-sulfonyl chloride and resorcin-described in JP-A-55-76346
Ester compounds with pyrogallol-acetone copolycondensates and O-quinonediazide compounds that are particularly useful include O-naphthoquinonediazide sulfonyl chloride in polyesters having a hydroxyl group at the terminal described in JP-A-50-117503. esterification reaction, JP-A-5'0-11330! Examples include homopolymers of p-hydroxystyrene or copolymers of this with other copolymerizable monomers, and those obtained by esterification of Ico-naphthoquinonediazide sulfonyl chloride, as described in Publication No. It will be done.

The content of these 0-quinonediazide compounds is preferably 5 to 80% by weight, particularly preferably 10 to 50% by weight, based on the total solid content of the photosensitive composition.

Such a quinone diazide type positive photosensitive material can be used in combination with an alkali-soluble resin as a binder if necessary. As the alkali-soluble resin, those obtained by bonding phenols and ketones or aldehydes in the presence of an acidic catalyst are preferred. As the phenols,
Examples include phenol, cresol and p-substituted phenol. Examples of the aldehydes include acetaldehyde and formaldehyde, with formaldehyde being preferred. Acetone is preferred as the ketone.

Preferred alkali-soluble resins include, for example, 78nol-formaldehyde resin, cresol-formaldehyde resin, phenol φ cresol-formaldehyde copolycondensate resin as described in JP-A-55-57841, and JP-A-55-127553. Copolycondensate resins of p-substituted phenol and phenol or cresol and formaldehyde as described in the above publication, condensates of benzaldehyde and polyhydric phenols such as resorcinol-benzaldehyde resins and pyrogallol-benzaldehyde resins, Pyrogallol - resorcinol -
Examples include copolycondensates of polyhydric phenol and acetone such as acetone resin, and xylenol formaldehyde resins. The content of these alkali-soluble resins is preferably I to % by weight based on the total solid content of the photosensitive composition, particularly 50% by weight.
~85% by weight is preferred.

Another photosensitive material that can be used is a diazo resin typified by a condensate of an aromatic diazonium salt and formaldehyde. Particularly preferred are salts of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde, such as reaction products of hexafluorophosphates, tetrafluoroborates, perchlorates or periodicates with said condensates. and diazo resin organic salts which are the reaction products of the above condensate and sulfone 111M, as described in US Pat. No. 3,300,309. Furthermore, diazo resins are preferably used together with binders. As such a binder, various polymer compounds can be used, but preferably a monomer having an aromatic hydroxyl group, such as N-(4 -Hydroxyphenyl)acrylamide, N-(4-hydroxyethyl)methacrylamide, ``''#-1 or p-hydroxystyrenoso#-9 or p-hydroxy7! Copolymers of nil methacrylate, etc. and other monomers,
Hydroxyethyl acrylate units or polymers containing hydroxyethyl acrylate units as a main repeating unit as described in U.S. Pat. 3,751,
257, linear polyurethane resins as described in U.S. Pat. No. 3,660,097, heptatalated polyvinyl alcohol resin, epoxy condensed from bisphenol A and epichlorohydrin. resin, cellulose acetate, -kkQ
-Includes celluloses such as suacetate phthalate.

Further suitable photosensitive materials include those based on polymeric backbone chains or photosensitive polymers such as polyamides, polycarbonates, and the like. for example,
Photosensitive polyester obtained by condensation of phenylene diethyl acrylate with hydrogenated bis-7, nor-A and triethylene glycol, as described in JP-A-55-40415, U.S. Pat. No. 2,956,8
Cinnamylide/as described in specification No. 78
Examples include photosensitive polyesters derived from (2-globeride/)malonic acid combinations such as malo/acid and difunctional glycols.

As another photosensitive substance, aromatic azide compounds in which the azide group is bonded directly or via a carbonyl group or a sulfonyl group to an aromatic ring are also used. For example, polyazidostyrene as described in U.S. Pat. No. 3,096,311, polyvinyl-p-azidobenzoate, polyvinyl-p-azidobenzal, Azido Aryl Sul 7
Reaction products of anyl chloride and unsaturated hydrocarbon polymers, as well as those described in Japanese Patent Publications Nos. 43-21067, 44-229, 44-22954, and 45-24915. , a polymer having sulfonylacetoyacarbonyl azide, and the like.

Furthermore, as another photosensitive material, a photopolymerizable composition comprising an addition polymerizable unsaturated compound is also used.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

However, the embodiments of the present invention are not limited to these.

Example 1 Steel plate with a thickness of 0.17 mm (Toyo Kohan ■ Hyde, P11
A steel plate) was used as an anode in an aqueous solution containing 50 g/e of sodium hydroxide at a bath temperature of 30°C and a current density of 10 A7d.
The above steel plate was electrolytically degreased under the conditions of 1 minute of treatment time. After washing with water, the steel plate was used as an anode and a lead plate was used as a cathode, and the bath temperature was 30' in an aqueous solution containing 50 Ve of sulfuric acid. The electrolytically degreased steel sheet was electrolytically etched under the conditions of a C1 current density of 15 j%)/'dm'' and a treatment time of 1 minute. Thereafter, the film was washed with water, and the smut produced by electrolytic etching was removed by rubbing with a sponge.

Chromic anhydride 25097 was applied to this electrolytically etched steel plate.
e, using an electrolytic solution containing 2.511A of sulfuric acid, the bath temperature (9
)C, a current density of 20 Vdmt, and an electrolytic time of 3 minutes.Chromium plating was performed under the following conditions.

Next, the steel plate that had undergone the main treatment step in this manner was subsequently washed with shower water, and then transferred to the next post-treatment step. In the post-treatment process, first, add 4% to 5% caustic soda aqueous solution.
Immerse for 1 minute at 0°C, then wash with shower water, and then soak in an aqueous solution of carboxymethyl cellulose sodium salt and calcium acetate (0.07% by weight each) at room temperature for about 1 minute.
I soaked it for a minute, then took a shower and rinsed it off. After completing the post-treatment step, drying was performed with cold air.

When observing the surface shape of this support with an electron microscope, it was found that the diameter was 0.
．． Polyhedral chromium crystal particles of 5 to 8 μm and their aggregates were uniformly distributed on the surface. Next, the surface roughness of this support was measured. The surface roughness meter is Perth
Belt meter (PerthomeLe) manufactured by
r) The measurement was carried out using 85P under the following measurement conditions.

Needle cartridge; RT-50C (diamond needle,
Radius of the tip of the needle: 5 μm) Sensitivity adjustment of the needle; Adjustment profile based on Pen-10-1, 9, and 0 pm; Roughness profile R Vertical magnification; 2.5 μm Horizontal magnification; 250 μm Cutting depth C; 2. 0 μm Measurement length: 4.0 μm Force, to-off value, 0.8 m The values of the peak count, burry count, and center line average roughness of the obtained steel plate are as follows.

(After electrolytic etching, before chrome plating) Center line average roughness = 0.6 μm (After chrome plating, before post-treatment) Center line average roughness Ra = 0.62 The above value is the average of the measured values at 10 different locations. It is a value.

Next, a photosensitive coating solution having the following composition was coated onto the post-treated support using a rotary coater and dried at 100° C. for 4 minutes to obtain a lithographic printing plate material.

(Photosensitive coating liquid composition) Condensate of naphthoquinone-(1,2)-diazide-)-5-sulfonic acid chloride and resorcinol-benzaldehyde resin (described in Example 1 of JP-A-56-1044) 2.6 g Copolycondensation resin of phenol, m-e P-mixed cresol and formaldehyde (7, molar ratio of nor to cresol is 3 near, weight average molecular weight 1500) 7.8 g Naphthoquinone-(1,2)-diazide-(2)-4-sulfonic acid chloride 0.15g Victoria Pure Blue BOHO, 15g (manufactured by Odugaya Kagaku ■) p-t-butylphenol and p-octylph.

Novolak resin synthesized from nol and formaldehyde and nandoquinone-(1,2)-diazide-(2)-
5-Sulfonic acid chloride and diester compound (condensation rate mol %) o, +19 methyl cellosolve 1009 The coating weight after drying was about 2.19β.

A step tablet for sensitivity measurement (Kodak 2, manufactured by Eastman Kodak) and a positive original film were closely attached to the obtained lithographic printing plate material, and a 2KW metal halide lamp (Idol Fin 2000, manufactured by Iwasaki Electric Co., Ltd.) was applied. The plate was exposed to light for 70 seconds from a distance of 1 m using as a light source, and developed with a 4% sodium metasilicate aqueous solution at 5° C. for 45 seconds, and the non-surface line portions were completely removed to obtain a lithographic printing plate.

In order to examine the adhesion between the support and the image area and the printing durability of the printing plate, a processing chemical resistance test and a printing test were conducted.

As a processing chemical resistance test, Ultra Plate Cleaner (A, B), which is used as a cleaning liquid to remove background stains that occur in non-image areas during printing, was used.

C, manufactured by Chemical ■) was investigated.

The printing plate with the image with the above grayscale density difference is added to the Ultra Plate Cleaner stock solution for 4 hours at room temperature.
After immersion for 0 minutes, the sample was washed with water and compared with the image area before immersion to determine the degree of corrosion of the image area against the processing chemicals.

As a result, the printing plate had no erosion in the image area, and the halftone dots were preserved up to the halftone dots with an area ratio of 2%, showing good resistance to processing chemicals. Next, place another printing plate in an offset printing machine (Hamadustar 900CDX), soak the surface of the printing plate in the Ultra Plate Cleaner stock solution, rub the entire surface of the printing plate with this sponge, and apply it to the printing plate for 4 minutes. Contact the image area with the Ultra Plate Cleaner. After that, it is washed with water and 500 sheets are printed. This cycle is repeated many times, and the number of cycles until the image area is eroded and cannot be printed is determined by the chemical attack resistance of the printing plate due to the synergistic effect of the chemical attack caused by the processing chemicals and the physical abrasion caused by printing. Gender was also considered at the same time. the result.

The printing plate gave good printing up to n cycles. The printing durability test was conducted by applying another printing plate to the offset printing machine, and was evaluated based on the number of prints obtained until the image area was damaged and printing became impossible. As a result, good quality printed matter was obtained using the printing plate. Further, the printing plate was hardly stained during printing and had good water retention. Furthermore, scratches on the image area also occurred, causing 0 damage. Comparative Example 1 Using the same steel plate as in Example 1,
Iron plating was applied as described in No. 92.

That is, using a carbon plate as an anode on the steel plate, using a sulfur solution containing 400 El/e of ferrous chloride and 2009/e of calcium chloride and having a pH of 0.8, the bath temperature was 100°C and the current density was 30 A/dm20. Iron plating was carried out to a thickness of 5 μm to obtain an iron-plated steel sheet.

This iron-plated steel sheet was chromium-plated in the same manner as in Example 1.

When observing the shape of this support surface with an electron microscope, Example 1
Chromium crystal particles similar to the above were spread all over the area.

Next, the same post-treatment as in Example 1 was performed, including washing with water and drying. Furthermore, the surface roughness of this support was measured in the same manner as in Example 1, and the following results were obtained.

After iron plating, before chrome plating, peak count 52 = 137 S, = 12 Barry count Tt = 12 T, = 12 Center line average roughness island = 0.6 μm After chrome plating, before post-processing peak count S2 2 140 S, = 13 Burry count T2 = 13 Tr = 13 Center line average roughness R, = = S as 0.63 μm or more
, /S, = 11.4, 'rt/'r, = 1 and S, /S, = 10.8, T2/T, = 1, and the roughness profile differs from that of the support of the present invention. It has a shape.

Next, the same formulation as in Example 1 was coated onto the post-treated support to obtain a lithographic printing plate material. The coating weight after drying was approximately 2.1 El/rr:.

The lithographic printing plate material was exposed and developed in the same manner as in Example 1 to obtain a lithographic printing plate.
The same processing chemical resistance test and printing test were conducted. As a result, when this printing plate was immersed in Ultra Plate Cleaner for a period of time, significant erosion of the image area was observed, and even halftone dots with an area ratio of 5% disappeared. Furthermore,
In a simultaneous study of processing chemical resistance and printing durability, the image area was already eroded and printing became impossible after 8 cycles of rubbing with Ultra Plate Cleaner and printing 500 sheets. Also, in the printing durability test, after about 90,000 sheets were printed, damage to the image area occurred (-, the printing durability was poor).

Example 2 A steel plate that had been electrolytically etched and desmutted in the same manner as Example 1 was treated with an electrolytic solution having the following composition: chromic anhydride 43'Og/e barium nitrate 3.8g/e nitric acid ( 64%) 1.2m/! / e Ammonium hydrogen fluoride 5 g/e Acetic acid 0.2 g/ll Barium fluoride o, ig, "g Electrolytic conditions Current density 5 A/dm2 Liquid temperature 5°C Cathode Iron-plated steel plate Anode Lead plate treatment time After 5 minutes, the same post-treatment as in Example 1 was carried out, followed by washing with water and drying.

When the surface shape of this support was observed with an electron microscope, plate-like chromium crystals protruded from the surface, and these plate-like crystals had a diameter of 1 to 5 μm, a thickness of 0.1 to 0.5 μm, and a shape of Polygonal, mainly hexagonal plates. It was observed that the plate-like crystals of chromium covered the surface as shown in FIG.

When the surface roughness of this support was measured in the same manner as in Example 1, it was found that St * Sl s Tz J T+ p R
Almost the same value as the support of Example 1 was obtained for both a.

A photosensitive coating liquid having the same formulation as in Example 1 was similarly coated onto the thus obtained steel plate support having an electrodeposited chromium layer on its surface to obtain a lithographic printing plate material.

(Coating weight: 2.39β) This lithographic printing plate material was exposed and developed in the same manner as in Example 1 to obtain a lithographic printing plate.
The same processing chemical resistance test and printing test were conducted. As a result, this printing plate had similar treatment chemical resistance and
Printed matter with good water retention and printing durability was obtained.

Example 3 A steel plate of the same type as in Example 1 was electrolytically degreased in the same manner as in Example 1, washed with water, and then treated with an aqueous solution containing sulfuric acid loo E/e at a bath temperature of 40° C. and a current density of 80 ty'rkr.
t, electrolytic etching was performed for a treatment time of 15 seconds, and smut was removed in the same manner as in Example 1 while washing with water.

Chromic anhydride 250F on this steel plate! //! , sulfuric acid 2.
Chromium plating was performed using an electrolytic solution containing 5 El/e at a bath temperature of 35° C., a current density of (9)h7a,,t, and a processing time of 2 minutes.

Next, the surface roughness was measured in the same manner as in Example 1, and the following results were obtained.

After electrolytic etching, peak count before chromium plating S, = 76 S+”89 Barry count Tz = 89 T+ = 44 Center heddle average grain size Ra - 0.6 μm Peak count after chrome plating S2 = 78 S, = 92 Barry count T, =92 T+=46 Center helix average roughness Ra = 0.62 μm Furthermore, post-treatment was performed in the same manner as in Example 1 (~, water washing and drying were performed. However, the aqueous solution of carboxymethyl cellulose sodium salt and calcium acetate used was The concentration is 0.35 deuterons each.

When the surface shape of this support was observed using an electron microscope, it was found that ROM crystal particles and their aggregates were distributed on the surface, as in Example 1.

Next, a photosensitive coating solution having the following composition was coated onto this support using a rotary coater and dried at 100° C. for 4 minutes to obtain a lithographic printing plate material.

(Photosensitive coating liquid composition) Condensate of naphthoquinone-(1,2)-diazide-(2)-5-sulfo/acid chloride and resorcinol-benzaldehyde resin←Described in Example 1 of JP-A-56-IQ44 2.9g Copolycondensation resin of phenol, m-s P-mixed cresol and formaldehyde (mole ratio of face shield cresol 1:9, weight average molecular weight 1500) 7.1 F Naphthoquinone-(1,2)-diazide-(2)-4-sulfo/acid chloride 0.1sIi Oil Blue #60
3 (manufactured by Orient Kagaku Kogyo ■) 0.2 1p-t-butylphenol formaldehyde novolac resin o
, isg methyl cellosolve 1 ooy The coating weight after drying was about 2.3 p.

On the lithographic printing plate material obtained in this way, a positive original film, a step for measuring sensitivity, and a button plate (A 2 manufactured by Eastman Koda, Inc., 21 levels with a density difference of 0.15 each) were adhered and 2KW metal halide was applied. Exposure was carried out for 2 seconds from a distance of 1 m using a lamp (IDOLFI Y2000 manufactured by Iwasaki Denki Co., Ltd.) as a light source, and the plate was exposed with a 4% aqueous sodium metasilicate solution at 5° C. for 45 seconds to obtain a lithographic printing plate.

In order to examine the adhesion between the support and the image area and the printing durability of the printing plate, a processing chemical resistance test and a printing test were conducted.

As a treatment chemical resistance test, durability against an aqueous isopropyl alcohol solution used in a Dahlgren dampening device was investigated.

Image i having a density difference on the above gray scale stairs;
After soaking the printed printing plate in 35% isopropyl alcohol aqueous solution for 9 minutes at room temperature, wash it with water and rub the image area with absorbent cotton soaked in water, and compare the image area with the image area before immersion in isopropyl alcohol. The degree of corrosion of the image area against chemicals was determined by this method. As a result, the printing plate showed no erosion of the image area and had good resistance to processing chemicals.
Similar to Example 1, in a simultaneous study of treatment chemical resistance and printing durability, the cycle of rubbing with Ultra Great Cleaner and printing 500 sheets was repeated up to 45 times and good printing was achieved.

Furthermore, in the same printing durability test as in Example 1, good prints were obtained with the printing plate up to 40,000 copies.

Comparative Example 2 A steel plate of the same type as Comparative Example 1 was plated with iron in the same manner as in Comparative Example 1, and then this iron-plated steel plate was plated with chrome under the same conditions as in Example 3.

Next, the same post-treatment as in Example 3 was performed, followed by washing with water and drying.

The surface roughness of this support was measured in the same manner as in Example 1 and was found to be 1! p SI # 'r, y 'rXl
Almost the same value as the support of Comparative Example 1 was obtained for both Ra.

below! After 7 days, the same formulation as in Example 3 was applied in the same manner as in Example 3 to obtain a lithographic printing plate material.

The coating weight after drying was approximately 2.31/pi.

The lithographic printing plate material was exposed and tested in the same manner as in Example 1. As a result, when this printing plate was immersed in a 35% isopropyl alcohol aqueous solution for an additional period of time, significant erosion of the image area was observed. a soo
By the 15th cycle of printing, the image area had already been eroded and the printing process had become impossible. Furthermore, it was 13 in the printing durability test.
After printing about 10,000 sheets, the image area became damaged and printing became impossible.

Example 4 Electrical FIIF was applied to the same type of copper plate as in Example 1 in the same manner as in Example 2.
x 7-F 7 F, smut was removed, followed by chrome plating, washed with water, and dried.

Next, a photosensitive coating liquid having the following composition was applied to this support using a rotary coater, and dried at 85° C. for 3 minutes to obtain a lithographic printing plate material.

(Photosensitive coating liquid composition) Copolymer A 5. OIi Diazo resin B 0.5.9 Julymer AC-log, 0.0511 (Japan Pure)
Victoria Pure Blue BOH0,1N (Odugaya Kagaku ■ Co., Ltd.) Methyl cellosolve 100 is added to the above copolymer at a molar ratio of 11 p-hydroxyphenylmethacrylamide/acrylonitrile/ethyl acrylate/methacrylic acid = 10/ 30 /60
/6 and azobisisobutyronitrile (1/400 molar amount of the total number of monomers) were dissolved in methyl cellosolve, heated at 65°C for 10 hours in a sealed tube purged with nitrogen, and after the completion of the reaction. The reaction solution was poured into water with stirring, and the resulting white color was filtered and dried. Diazo resin B is
5% diazo resin (trade name, E, H, C■an) at room temperature
-ox2) aqueous solution and a 10% ammonium hexafluorophosphate aqueous solution, the resulting precipitate is absorbed and filtered,
It is a hexafluorophosphate obtained by wave pressure drying at 30 to 40°C. The weight average molecular weight of the above copolymer is 80,00
Furthermore, gel permeation chromatography (GPC) of the molecular weight distribution of the above-mentioned diazo tree fertilizer revealed that 93 mol% of the total amount was 93 mole % of the total.

The coating weight after drying was approximately 2.011/vl.

A negative original film was placed in close contact with the lithographic printing plate material obtained in this manner, and exposure was performed for u seconds from a distance of 1 m from the side using a 2KW metal halide lamp (Idol Fin 2000 manufactured by Iwasaki Electric Co., Ltd.) as a light source. A lithographic printing plate was obtained by developing with a developer.

(Developer composition) Phenyl Cellosolve 100I Diethanolamine 5011 Pionin A-44B 30 Jim (manufactured by Takemoto Yushi ■) Water 780 # Development conditions were 5° C. and 6 seconds.

In order to examine the adhesion between the support and the image area, the latitude of developability, and the printing durability of the printing plate, we conducted a one-hand development process test in addition to the process using an automatic developing machine, and also the printing process. I conducted a test.

Manual development was carried out by thoroughly soaking a sponge with the above developer, and lightly rubbing the surface of the exposed lithographic printing plate material placed in a dish with the sponge evenly for 2 minutes, followed by washing with water. As a result, the image area of the above lithographic printing plate material was not damaged at all even by manual development. The printing test was carried out in the same manner as in Example 1. As a result, good prints were obtained from the lithographic printing plate using the support of the present invention up to the n-way.

Comparative Example 3 A steel plate of the same type as Example 1 was plated with iron in the same manner as in Comparative Example 1, and further plated with chrome under the same conditions as in Example 2, washed with water, and dried.

Next, a photosensitive coating solution having the same composition as in Example 4 was applied to this support in the same manner as in Example 4, and dried to obtain a lithographic printing plate material. Next, a lithographic printing plate was prepared in the same manner as in Example 4, and a manual development process and a printing durability test were performed in the same manner. As a result, during manual development processing, the image area was significantly damaged and almost peeled off. Furthermore, in printing, after printing 80,000 sheets, part of the image area peeled off, making it impossible to print.

Example 5 A steel plate of the same type as in Example 1 was subjected to electrolytic etching and smut removal in the same manner as in Example 1, and then zinc plated to a thickness of 0.5 μm, and then chromium plated in the same manner as in Example 1. Then, apply a photosensitive coating liquid in the same manner as in Example 1,
A lithographic printing plate material was obtained. Then, it was developed in the same manner as in Example 1 [i4 original] to obtain a lithographic printing plate.

When this printing plate was printed in the same manner, good quality printed matter was obtained with no scumming.

Example 6 A copper plate of the same type as in Example 1 was electrolytically etched and smut removed in the same manner as in Example 1, then nickel plated to a thickness of 0.2 μm, and then chromium plated in the same manner as in Example 1. Hereinafter, in the same manner as in Example 1, coating of the photosensitive coating liquid (IT
, 7EL original, current 1#! The process was carried out to produce lithographic printing plate materials.

When this printing plate was printed in the same manner, it was possible to obtain printed matter of good quality with no background smearing.

Example 7 A steel plate of the same type as in Example 1 was subjected to electrolytic etching and smut removal in the same manner as in Example 1, and then nickel plated with Pi-1.5 μm.
A lithographic printing plate was obtained by applying a color coating liquid, exposing to light, and developing.

When the same printing was carried out on this printing plate, a good quality printed matter was obtained with no scumming.

Example 8 A steel plate of the same type as in Example 1 was subjected to VC electrolytic etching to remove smut in the same manner as in Example 1, then galvanized to a thickness of 1.5 μm, and thereafter coated with a photosensitive printing plate in the same manner as in Example 1. , n-source development was performed to obtain a lithographic printing plate.

When similarly printed using this printing plate, a good quality printed matter was obtained with no scuffing.

Example 9 A steel plate of the same type as in Example 1 is subjected to electrolytic etching and smut removal in the same manner as in Example 1, and then aluminum is vapor deposited on the surface to form a 1 μm thick layer.

Furthermore, anodic oxidation treatment is performed in a sulfuric acid bath to add aluminum oxide to the surface.
After that, a photosensitive coating solution was applied, exposed, and developed in the same manner as in Example 1 to obtain a lithographic printing plate.

When the above printing plate was printed in the same manner, good printed matter with excellent water retention and no scumming was obtained, and the printing durability was also good.

Example 1O A steel plate of the same type as in Example 1 was treated in a grain chamber by plane honing, then washed with dilute hydrochloric acid, and immediately after washing with water, the steel plate was subjected to chromium plating and post-treatment in the same manner as in Example 3. did. When the surface shape of the support was observed with an electron microscope, polyhedral chromium crystal particles with a diameter of 0.5 to 8 μm were dispersed on the surface.

Furthermore, when the surface roughness of this support was measured in the same manner as in Example 1, the following results were obtained: After honing (before chrome plating) S1 = 92 Center line average roughness Ra = 0.6 μm After chrome plating (Before post-treatment) S, = 92 w T, = 62 Center line average roughness Ra - 0.62 μm Next, the same photosensitive coating liquid as in Example 1 was applied onto the chromium-plated support in the same manner, A lithographic printing plate material was obtained.

The coating weight after drying was approximately 2.41/d.

Furthermore, a lithographic printing plate was obtained by the same operation as in Example 1.

This printing plate was subjected to the same processing chemical resistance test and printability paper @ as in Example 1. As a result, in a simultaneous study of processing chemical resistance and printing durability, good printing was achieved even when the cycle of rubbing with Ultra Plate Cleaner and printing 500 sheets was repeated up to 32 times. Furthermore, in a printing durability test, the printing plate was able to print satisfactorily up to 60,000 sheets.

Comparative Example 4 A steel plate of the same type as in Example 1 was subjected to a grain pattern treatment by sandblasting, then immersed in rmvc, washed with water, and immediately subjected to chromium plating and post-treatment in the same manner as in Example 1O. On the surface of this support, Example 10
Similar to the support, ROM crystals were present. Next, the surface roughness of this support was measured in the same manner as in Example 1, and the following results were obtained.

After sandblasting (before chrome plating) Peak count S! = 32 S, -6 Burry count T, = 6 'workゝ, = 6 Center line average roughness Ra = 0.50 μm After chrome plating (before post-treatment) Peak count S, = 34 S1 = 6 Burry count T2 = 7 T, = 7 Center average roughness Ra = 0.52 μm Furthermore, the same photosensitive coating liquid as in Example 1 was similarly coated on the chromium-plated support to obtain a lithographic printing plate material.

The coating weight after drying was approximately 2.511/go.

Next, a lithographic printing plate was obtained by the same operation as in Example 10. This printing plate was subjected to a treatment chemical resistance test and a printability test in the same manner as in Example 1O. As a result, in a simultaneous study of processing chemical resistance and printing durability, it was found that the image area was already eroded and printing became impossible after 16 cycles of rubbing with the Ultra Plate Cleaner and printing 500 sheets. Furthermore, in a printing durability test, the image area was damaged after about 150,000 sheets were printed, and the printing durability was poor.

Example 11 A steel plate of the same type as in Example 1 was subjected to the same electrolytic degreasing treatment as in Example 1, and after washing with water, the A plate was used as an anode, the lead plate was used as a cathode, and sulfuric acid 50!1/no. The electrolytically degreased steel sheet was subjected to the electrolytic degreasing process for 1 minute in an aqueous solution containing:
U-etched. Thereafter, it was washed with water and the smut generated by electrolytic etching was removed by rubbing with a sponge.

This electrolytically etched steel plate was chromium plated in the same manner as in Example 1, and further post-treated. When observing the surface shape of this support with an electron microscope, the diameter was 0.5 to 8.
Polyhedral chromium crystal particles of μm size and their aggregates were dispersed on the surface. Next, the surface roughness of this support was measured in the same manner as in Example 1, and the following results were obtained.

After electrolytic etching (before chrome plating) Burry count T, = 93 Bury count T, = 35 T2/T, = 2.7 Center line average roughness Ra = 0.55 μm After chromium plating (before post-treatment) Center line Average roughness Ra=0.57 μm Further, the same photosensitive coating solution as in Example 3 was applied onto the chromium-plated support in the same manner as in Example 3 to obtain a lithographic printing plate material.

The coating type n after drying was approximately 2.41/77L''.

Next, a lithographic printing plate was obtained by the same operation as in Example 3. This printing plate was subjected to a treatment chemical resistance test and a printing test in the same manner as in Example 1.

As a result, in a simultaneous study of processing chemical resistance and printing durability, good printing was achieved even when the cycle of rubbing with Ultra Plate Cleaner and printing 500 sheets was repeated up to 18 times. Furthermore, in a printing durability test, the printing plate was able to perform good printing up to m-way.

Comparative Example 5 A steel plate of the same type as Example 1 was subjected to electrolytic degreasing treatment in the same manner as in Example 1, and after washing with water, the steel plate was used as an anode,
Lead plate t @ electrode, bath temperature 10℃, current density 5A/dm'', treatment time 1 with an aqueous solution containing 22.511/1
The sub-plate subjected to the IZ decomposition process was electrolytically etched under conditions of 1 minute. Thereafter, the smut was removed by washing with water.

This electrolytically etched steel plate was chromium plated in the same manner as in Example 1, and further post-treated. What is the surface shape of this support? When observed with a beam electron microscope, the surface was similar to that of the support of Example 11 and was covered with ROM crystal particles and aggregates thereof. Next, the surface roughness of this support was measured in the same manner as in Example 1, and the following results were obtained.

After electrolytic etching (before chrome plating) Beak count g, = 25 Barry count T, = 2 T, / TI = 1 FT, = 2 Center line average roughness R1 = 0.3 μm After chrome plating (before post-treatment) Peak count 8t = 29 # 5t = 3 Burry count T2 = 3 T1 = 3 Center axis average roughness Ra = 0.35 μm Furthermore, the same photosensitive coating liquid as in Example 11 was applied on the chromium-plated support. Coating was carried out in the same manner to obtain a lithographic printing plate material.

The coating criticality after drying was approximately 2.4 F/m.

Next, a lithographic printing plate was obtained by the same operation as in Example 11.

This printing plate was subjected to a treatment chemical resistance test and a printed form 112 in the same manner as in Example 11. As a result, in a simultaneous study of processing chemical resistance and printing durability, it was found that the existing &C image area was eroded and printing became impossible after five cycles of rubbing with the Ultra Plate Cleaner and printing 500 sheets. Also, in the rigidity test, damage to the image area occurred after about 70,000 copies were printed, and the rigidity was poor.

Effects of the Invention The lithographic printing plate using the iron-based lithographic printing plate support according to the present invention has excellent processing chemical resistance and printing durability, and also has good water retention, so that there are no scratches on the printing plate surface. There is no need to add (and there is also a large degree of latitude in the development method.

[Brief explanation of the drawing]

FIG. 1 is a roughness profile showing peak counts (st, st), ! TrL is the measured length;
The mark K shows the peak of peak count S, the mark φ shows the beak of peak count S, C is the cutting depth, 1 is the center cotton, 2 is the upper cutting line, and 3 is the lower cutting gIf: shown. Fig. 2 shows the roughness profile showing the burry count T1, where the measurement length is 1 mfrl, 1 is the center line, 2 is the upper cutting line, 3 is the lower cutting line, and the 100 marks rs:, s Lee count) Tt shows the peak of 3vli is a roughness profile showing the burry count τ, im is the measurement length, l is the center line, 2 is the upper cutting line, and 0 mark is the beak of the burry count T. The fourth factor (photo) is that the surface is roughened by electrolytic etching and the cutting depth is 2 μm, and Bz /5s = 0.
,8,T,/T,=2,Scanning electron micrograph of the surface of a steel material with a surface roughness of Ra=0.6 μm (magnification: 700
times, angle of inclination 45°). Figures 5 to 7 (all photographs) show scanning electron micrographs (all magnifications: 700x; tilt angle: 456) of the surface of the support of the present invention. Fig. 8 (photo) shows that the surface is roughened by iron plating and the cutting depth is 21 tm, with St/St = 10.8.
Scanning electron micrograph of the surface of a steel material with a surface roughness of Tt/Ts = 1 and Ra = 0.5 μm (magnification 700
times, angle of inclination 45'). Agent KuwaTjX#i Beauty

Claims (1)

[Claims] In a lithographic printing plate support based on iron material, the base material has a surface roughness of Grofile R with a cutting depth of 2.0 μm.
The ratio of peak counts (S,, St) at m is st
/ 8. = o, os ~ 5.0, and the ratio of Barry count ('r + t'rt) is T! / T, = 1.1~
5.0. A support for a lithographic printing plate.