JPH03122241A - Aluminum alloy material for lithographic printing plate and its manufacture - Google Patents

Abstract

PURPOSE:To improve the electrochemical roughening treatability, plate wear resistance and ink staining resistance of a printing plate made of an Al alloy by adding a specified amt. of Ti to an Al alloy having a specified compsn. and specifying the quantitative relationship between Ti and Ga as impurities. CONSTITUTION:The Al alloy material for lithographic printing is the one contg., by weight, 0.1 to 1.0% Fe, 0.03 to 0.2% Si, 0.005 to 0.05% Cu, <=0.1% Ti, <=0.04% Ga and the balance Al and in which the relationship between Ti and Ga satisfies the inequality. The alloy has excellent plate wear resistance as well as excellent staining resistance because the pits by electrochemical roughening are fine and uniform. Ga is the impurities included inevitably in the Al metal and distorts the shape of the pits to deteriorate the plate wear resistance of a printing plate, so Ti is added in the above-mentioned manner in order to suppress the above effect. However, in the case of >0.04% Ga, the distortion of the pits can not be improved even if Ti is added.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an aluminum alloy for lithographic printing plates having excellent electrochemical surface roughening treatment and ink stain resistance, and a method for producing the same.

[Prior Art] In general, aluminum plates have been used as supports in planographic printing, but their surfaces are roughened in order to improve the adhesion of photosensitive films and water retention in non-image areas. It is necessary.

Conventionally, mechanical surface roughening methods such as the pole grain method, brush grain method, and wire grain method have been used for this surface roughening treatment. A method has been adopted in which the surface of aluminum is electrochemically roughened using nitric acid (hereinafter referred to as electrolyte) and nitric acid or an electrolyte containing nitric acid (hereinafter referred to as nitric acid-based electrolyte). This electrochemical surface roughening method has been rapidly developed in recent years because it has excellent plate-making suitability and printing performance, and is suitable for continuous processing of coil materials.

Conventionally, aluminum alloy plates for lithographic printing plates have been prepared using JIS standard Al100 (aluminum purity of 99.0% by weight or more) and A3003 (aluminum purity of 99.0% by weight or more) for mechanical roughening.
For the electrochemical surface roughening method, A 1050 (aluminum purity 99.5%), which provides a relatively uniform electrolytically roughened surface, is used. (wt% or more) equivalent material is used. When an electrochemically roughened material equivalent to A 1050 is used, relatively good printing durability is obtained. Printing durability refers to the maximum number of prints that can produce clear printed matter.

[Problems to be Solved by the Invention] In recent years, as the information age advances, the number of printed copies has increased dramatically, and as a result, the printing durability of printing plates made of materials equivalent to A1050 has become insufficient. Furthermore, as the number of printed sheets increases, the phenomenon that non-image areas of printed matter become smeared, ie, ink smudges, becomes more noticeable.

The present invention improves the above-mentioned drawbacks, and provides an aluminum alloy for lithographic printing plates that has extremely excellent electrochemical surface roughening properties, good printing durability, and excellent ink stain resistance, and a method for producing the same. The purpose is to provide

[Means for Solving the Invention] The present invention provides Fe: 0.1 to 1.0%, Si
: 0.03~0.2%, Cu: 0.005~0
．． 05%, 7i: 0.1% or less, Ga: 0.04
% or less, remaining Al and unavoidable impurities, T
The relationship between i and Ga is [T i (%)]≧L, 2
[G a (%)] An aluminum alloy material for lithographic printing plates having a value of 0.015 and an ingot of the alloy having the above composition were homogenized at 400 to 800°C, and then homogenized at 350 to 600°C.
A method for producing an aluminum alloy material for lithographic printing plates, which comprises heating to a temperature of 100% and hot rolling, followed by cold rolling, intermediate annealing, and finishing cold rolling with a plate thickness reduction rate of 50% or more. It is.

[Work] The constituent elements of the present invention will be specifically explained.

A 105, which has traditionally been used for planographic printing plates.
When a 0 alloy plate is subjected to electrochemical surface roughening treatment, the pits (hereinafter, pits resulting from electrochemical surface roughening are simply referred to as pits) may become distorted and become half-moon-shaped, or the depth of the pits may become shallow. It is easy to print and has a negative impact on printing durability. Also, A 10
When 50 alloy is used as a lithographic printing plate, the ink stain resistance is insufficient.

The present inventors conducted an analysis that did not include factors that affect the pit shape of Al-Fe alloys, and found that Ga, which is unavoidably included in the aluminum base metal, is the cause of distorting the pit shape, and that Ga has an adverse effect. It is effective to add Ti according to the Ga content to suppress the pits, and that adding an appropriate amount of Cu increases the depth of the pits. It has been found that it is effective to homogenize the mass at an appropriate temperature. Furthermore, it has been found that in order to improve the ink stain resistance, it is effective to make the amount of Si appropriate and to appropriately control the homogenization treatment temperature and the heating temperature during hot rolling.

The alloy composition based on the present invention will be explained below.

(1) Fe: Q, 1 to 1.0% Fe increases the strength of the alloy and makes the pits finer. If it is less than 0.1%, the effect will not be sufficient, and if it exceeds 1.0%, coarse compounds will increase and the pits will become non-uniform.

(2) Si: 0.03 to 0.2% St increases the strength of the alloy, forms an Al-Fe-5i compound, and contributes to the miniaturization of pits. If it is less than 0.03%, the effect will not be sufficient, and if it exceeds 0.2%, the ink stain resistance will deteriorate.

(3) Cu: 0.005 to 0.05% Cu increases the depth of pits and improves printing durability. 0.005
If it is less than 0.05%, the effect will not be sufficient, and if it exceeds 0.05%, the electrolytically roughened pits will turn into coarse independent bits.

(4) Ti: (1.1% or less Ti suppresses the effect of Ga that distorts the shape of pits. The effective amount of Ti added is determined by the following formula % formula % according to the amount of Ga included as an unavoidable impurity. The relational expression was derived through experiments, but it can be interpreted as follows: When the amount of Ga dissolved in aluminum exceeds a certain limit, the effect of distorting the shape of the pit becomes significant; When Ti is added, Ti and Ga
It is thought that the solid solution Ga is reduced to below a critical amount by forming a compound such as Ti2Ga, and as a result, the harmful effects of Ga are suppressed and the pits become minute circular shapes. Therefore,
It is necessary to determine the amount of Ti to be added according to the Ga content as shown in the above formula, and if this is done, the pits will become fine circular shapes and printing durability will be improved.

On the other hand, when the amount of Ti exceeds 0.1%, coarse compounds are formed and coarse pits increase.

(5) Ga: 0.04% or less Ga is an impurity inevitably contained in aluminum metal. - Boat fishing often contains about 0.004 to 0.020%, but when scrap is remelted, it may be contained in an even higher amount. Ga has the effect of distorting the shape of the pits and deteriorating the printing durability of the printing plate.

In order to suppress this effect, Ti is added depending on the Ga content as described above. However, if the Ga amount exceeds 0.04%, even if Ti is added, the pit distortion cannot be improved, so the Ga amount is specified to be 0.04% or less. Although it is difficult to fully explain this phenomenon, it can be interpreted as follows. In other words, if the Ga amount exceeds 0.04%, it is necessary to add a corresponding amount of Ti (0.033% or more), but in this case, Ti may cause segregation during casting of the alloy or cause other problems. It is thought that this causes the formation of compounds such as Al zTl, which prevents uniform distribution and results in insufficient effects.

Next, manufacturing conditions will be explained.

(1) Manufacturing process The aluminum alloy support of the present invention is manufactured by the following steps: casting, homogenization, hot rolling, cold rolling, intermediate annealing, and finishing cold rolling. However, the homogenization treatment and the heating before hot rolling can also be used. That is, after homogenization treatment, hot rolling can be performed as is, or hot rolling can be performed after cooling to a predetermined temperature.

It is desirable that the conditions in each manufacturing process be as follows. In other words, by manufacturing under the following conditions,
The characteristics of the alloy of the present invention as a lithographic printing plate material are more effectively exhibited.

(2) Casting: Performed by conventional methods. Usually, semi-continuous casting is used.

(3) Homogenization Treatment 2 In the homogenization treatment at 400 to 600° C., Fe and Si dissolved in supersaturated solid solution are precipitated, and Ga and Ti dissolved in solid solution are combined.

These make the pits minute and circular, contributing to improved printing durability. At temperatures below 400° C., the precipitation of Fe5Si is insufficient and the bonding between Ga and Ti is also insufficient, so that the shape of the pits tends to be distorted. When the temperature exceeds 600℃, Si
The amount of solid solution increases, and individual SL tends to precipitate in the subsequent process, making it easier to cause ink stains.

(4) Hot rolling Hot rolling is performed by heating to 350 to 600°C.

If it is less than 350°C, the deformation resistance is large, so the degree of working per roll cannot be increased, and the number of rolling passes becomes large, which is not economical. On the other hand, when the temperature exceeds 600° C., the amount of solid solution of St increases, and individual St is likely to precipitate in a subsequent process, making it easy to cause ink stains.

Further, if the temperature exceeds 450°C, coarse recrystallized grains are generated during hot rolling, and streaks due to a striated non-uniform structure are likely to occur, so the preferred temperature is 350 to 450°C.

(5) Cold rolling This is done to make the hot rolled plate thinner. The rolling degree is usually 5
It is carried out from 0 to 95%.

(6) Intermediate annealing Intermediate annealing is performed to recrystallize the material, and is usually
Performed at ~550°C. There is no need to specify the intermediate annealing method, and a method commonly used in industry, ie, a method using a batch furnace or a method using a continuous annealing furnace, is adopted. When annealing is performed in a batch furnace, heating is performed at 300 to 450°C for several hours, but since long-term annealing at high temperatures causes recrystallized grains to become coarse, annealing at 350 to 400°C is appropriate.

Continuous annealing furnace: 400-550℃ for 0 seconds (no holding)
Fine recrystallized grains can be obtained by heating for several tens of seconds. In this case, if held at 400 to 550°C, the recrystallized grains will become coarser, leading to a decrease in strength and easily breaking the grip of the printing plate.
Since the Fe-5t-based precipitates become coarse and the pits formed by the electrochemical surface roughening treatment become coarse, the shorter the holding time, the better, and 0 seconds (no holding) is most desirable.

(7) Increase the strength of the finished cold-rolled material and prevent the grip from breaking when wrapping the support around the plate cylinder. Rolling degree (plate thickness reduction rate) is 50
Perform at % or more. If it is less than 50%, the strength will be insufficient and the effect of preventing grip breakage will be lost.

Next, a method for surface treating an aluminum alloy support for lithographic printing plates according to the present invention will be described in detail.

The graining method in the present invention is an electrolytic surface roughening method in which alternating current is passed in a hydrochloric acid-based or nitric acid-based electrolytic solution to grain the surface.

In the present invention, the wire brush grain method in which the aluminum surface is scratched with a metal wire, the pole grain method in which the aluminum surface is grained with an abrasive ball and an abrasive agent, and the brush grain method in which the surface is grained in a nylon brush and an abrasive agent are used. A mechanical surface roughening method may be used in combination with an electrolytic surface roughening method.

Prior to electrolytic roughening treatment, rolling oil adhering to the aluminum surface or abrasives trapped after mechanical roughening (
Surface treatment is performed to remove mechanical roughening) and clean the surface. - For boat fishing, a method of cleaning the surface using a solvent such as trichlene or a surfactant is used to remove rolling oil. Also, 20 to 8% aluminum alloy plate is added to an aqueous solution of 1 to 30% sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, etc.
Alkaline etching is performed by immersion at a temperature of 0°C for 5 to 250 seconds, and then immersion in a 10 to 30% nitric acid or sulfuric acid aqueous solution for 2
A method of neutralizing and removing smut by soaking at a temperature of 0 to 70° C. for 5 to 250 seconds is generally used for both rolling oil removal and abrasive removal.

After surface cleaning of this aluminum alloy plate, electrolytic surface roughening treatment is performed.

The electrolytic solution used in the electrolytic surface roughening treatment in the present invention is
When using a hydrochloric acid solution, the concentration is preferably in the range of 0.01 to 3% by weight, more preferably 0.05 to 2.5% by weight.

Further, when using a nitric acid solution, the concentration is preferably 0.2 to 5% by weight, preferably 0.5 to 3% by weight.

In addition, this electrolyte may contain corrosion inhibitors (or stabilizers) such as nitrates, chlorides, monoamines, diamines, aldehydes, phosphoric acid, chromic acid, boric acid, oxalic acid, etc., as necessary.
A grain leveling agent, etc. can be added.

The temperature of the electrolytic solution is usually 10 to 60°C.

The alternating current used at this time can be any of rectangular waves, trapezoidal waves, and sine waves, as long as the positive and negative polarities are alternately converted. Phase alternating current can be used. Also, the current density is 5~
100 A/dm'' for 10 to 300 seconds.

The surface roughness of the aluminum alloy support in the present invention is
It is adjusted according to the amount of electricity and is set to 0.2 to 0.8 μm. 0
．． If it exceeds 8 μm, the roughened surface becomes extremely covered with macro pits, which is undesirable because it reduces printing durability and causes ink stains. Moreover, if it is less than 0.2 μm, control of the soaking water on the printing plate cannot be achieved, and some halftone dots in the shadow tend to smudge, making it impossible to obtain good printed matter.

Aluminum alloys with grains removed in this way are
Smut attached to the surface is removed using 50% hot sulfuric acid (40 to 60°C) or dilute alkali (sodium hydroxide, etc.). If removed with alkali, it is subsequently neutralized by immersion in acid (nitric acid or sulfuric acid) for cleaning.

After removing the smut from the surface, an anodic oxide film is applied. Although conventionally well-known methods can be used for the anodic oxidation method, sulfuric acid is used as the most useful electrolyte. Subsequently, phosphoric acid is also a useful electrolyte.

Furthermore, the mixed acid method of sulfuric acid and phosphoric acid disclosed in JP-A-55-28400 is also useful.

In the sulfuric acid method, treatment is usually performed using direct current, but alternating current can also be used. Sulfuric acid is used at a concentration of 5 to 30%, and electrolytically treated at a temperature of 20 to 60°C for 5 to 250 seconds to form an oxide film of 1 to 10 gem 2 on the surface. Furthermore, the current density at this time is preferably 1 to 2 OA/do'. In the case of the phosphoric acid method, a concentration of 5 to 50%, 3
At a temperature of 0 to 60°C, for 10 to 300 seconds, 1 to 15 A/
Processing is performed at a current density of d+n'.

In this way, after providing the anodic oxide film, post-treatment can be performed as necessary. For example, British Patent No. 1230
447, a method of immersion treatment in an aqueous solution of polyvinylphosphonic acid, and U.S. Pat. No. 3,181,481.
The method of immersion in an aqueous solution of an alkali metal silicate disclosed in the above publication is used. It is also possible to provide a hydrophilic polymer undercoat layer if necessary, but the choice is made depending on the properties of the photosensitive material to be provided afterwards.

A support produced by the production method of the present invention can be provided with a photosensitive layer exemplified below to form a lithographic printing plate.

[I] When a photosensitive layer containing a polyhydroxy bulky polymer compound O-naphthoquinonediazide sulfonic acid ester and a novolak resin mixed with phenol and cresol is provided.

As the polyhydroxy polymer compound, one having an average molecular weight of 1,000 to 7,000 is used, and has two or more hydroxy groups on a benzene ring, for example. Phenolic compounds (e.g. resorcinol, pyrogallol, etc.) and aldehyde compounds (e.g. formalin, benzaldehyde, etc.)
There are polycondensates with In addition, phenol-formaldehyde resin, cresol-formaldehyde resin, p
Examples include -tert-butylphenol-formaldehyde resin and phenol-modified xylene resin. A more suitable novolak resin is a phenol-m-cresol-formaldehyde novolak resin which contains a relatively high molecular weight phenol and is disclosed in JP-A-55-57841. In addition, in order to form a visible image upon exposure, 0-naphthoquinonediazide-4-sulfonyl chloride, an inorganic anion salt of p-diazophenylamine, a trihalomethyloxadiazole compound, a trihalomethyloxadiazole compound having a benzofuran ring, etc. Compounds that generate Lewis acids when exposed to light are added. On the other hand, as the pigment, triphenylmethane pigments such as Victoria Blue BOH, Crystal Violet, and Oil Blue are used. The photosensitive composition consisting of these components has a solid content of 0.5 to 3.0 g.
/+a2 is provided.

[■] When a photosensitive layer containing a diazo resin and a water-insoluble lipophilic polymer compound having a hydroxyl group is provided.

As mentioned above, after providing the anodic oxide film, U.S. Pat.
81461, in an alkali metal silicate bath. It is preferable to provide a photosensitive layer containing a PF6 salt or BF4 of a diazo resin, an organic salt of a diazo resin, and a water-insoluble lipophilic polymer compound having a hydroxyl group on the surface thus treated. When such a photosensitive layer is coated on the surface of the support according to the present invention, a photosensitive lithographic printing plate can be obtained which has excellent storage stability and visible imageability and is particularly stable under harsh conditions such as high temperature and high humidity.

The diazo resin for this purpose consists of a PF5 salt or a BF4 salt and an organic salt, including triisopropylnaphthalenesulfonic acid,
Aromatic sulfonic acids such as 4,4°-biphenyldisulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, ■-naphthol-5-sulfonic acid, and p-toluenesulfonic acid, 2-Hydroxy-4-methoxybenzophenone-5-
Examples include hydroxyl group-containing aromatic sulfonic acids such as sulfonic acid.

In addition, the weight average molecular weight of the hydroxyl group-containing polymer compound is 50.
For example, (1) N-(
4-hydroxyphenyl)acrylamide, N-(4-
(2) copolymers of o-1m-1 or p-hydroxystyrene and other monomers, (3) Examples include copolymers of o-1m-1 or p-hydroxyphenyl methacrylate and other monomers.

Examples of the above-mentioned monomers include (a) α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and maleic anhydride;

(b) Alkyl acrylates such as methyl acrylate and ethyl acrylate.

(c) Alkyl methacrylates such as methyl methacrylate and ethyl methacrylate.

(d) Acrylamide or methacrylamide such as acrylamide and methacrylamide.

(e) Vinyl esters such as ethyl vinyl ether and hydroxyethyl vinyl ether.

(f) Styrenes such as styrene and α-methylstyrene.

(g) Vinyl ketones such as methyl vinyl ketone.

(h) Olefins such as ethylene, propylene, and isoprene.

(!l) N-vinylpyrrolidone, N-vinylcarbazole, acrylonitrile, methacrylonitrile, etc. may be mentioned, and any other monomer that can be copolymerized with a monomer containing an aromatic hydroxyl group may be used.

The oil-soluble dyes added to the photosensitive layer include Victoria Pure Blue BOH, Crystal Violet, Victoria Blue Methyl Violet, and Oil Blue #60.
3rd grade is preferred. To form a photosensitive layer having these compositions, a fluorine-based surfactant, a nonionic surfactant, a plasticizer (for example, dibutyl phthalate, polyethylene glycol, diethyl phthalate, trioctyl phosphate, etc.) and a known stabilizer ( For example, phosphoric acid, phosphorous acid, organic acid) etc. are added so that the coating weight after drying is 0.5 to 2.5 g/n2.

[m] When providing a photosensitive layer made of a photopolymerizable photosensitive composition containing a polymer having a carboxylic acid residue or a carboxylic anhydride residue, an addition polymerizable unsaturated compound, and a photopolymerization initiator.

In the case of a photopolymerizable photosensitive material, the surface of the support grained in a hydrochloric acid bath is preferably anodized with phosphoric acid or a mixed acid of phosphoric acid and sulfuric acid.

A photopolymerizable photosensitive composition containing a polymer having a carboxylic acid residue or carboxylic anhydride residue, an addition polymerizable unsaturated compound, and a photopolymerization initiator after anodizing in a phosphoric acid bath and silicate treatment. Layer things. Also, JP-A-60-1
It can be used in a lithographic printing plate using an electrophotographic photoreceptor as disclosed in Japanese Patent No. 07042.

The printing plate formed in this way has good storage stability, and the surface of the exposed aluminum plate in the non-image area is resistant to staining with printing ink, and has good hydrophilicity to quickly remove stained ink. It has high adhesive strength with the photosensitive layer.

As a polymer having a carboxylic acid residue or a carboxylic anhydride residue suitable for this purpose, a polymer having a structural unit selected from the following [A1 to CD] is preferable.

(In the formula, R1 and R4 represent a hydrogen atom or an alkyl group, R3 is a phenylene group or an alkylene group that may have a hydroxy group, R5 is a hydrogen atom, an alkyl group that may have a substituent, R6 represents an alkyl group, an allyl group, an aryl group, or a cycloalkyl group that may have a substituent, and n represents 0 or 1) As a more specific structural unit, as formula (A), acrylic Examples of formula (B) include maleic acid, monohydroxyalkyl maleate, monocyclohexyl maleate, and formula (C) include monoalkyl maleate. Examples include amide, maleic acid monohydroxyalkylamide, and formula (D) include maleic anhydride, itaconic anhydride, and the like.

The polymer usually has an average molecular weight of 1,000 to 100,000.
Use the one.

The addition-polymerizable unsaturated compound has an ethylenically unsaturated double bond that mutually undergoes addition polymerization in a three-dimensional direction to cause insolubilization when the photopolymerizable photosensitive resin composition is irradiated with actinic rays. It is a monomer. Examples include unsaturated carboxylic acids, esters of unsaturated carboxylic acids and aliphatic polyhydroxy compounds, and esters of unsaturated carboxylic acids and aromatic polyhydroxy compounds.

As the photopolymerization initiator, benzoin, benzoin alkyl ether, benzophenone, anthraquinone, Michler's ketone, etc. can be used alone or in combination;
The amount of coating after drying is 3 g/+2.

A lithographic printing plate is created as described above.

[Example] The present invention will be explained in detail below with reference to Examples.

Example 1 Alloys No. 1 to No. 13 shown in Table 1 were melted and cast.
00■, a 3500mm long ingot, and heated to 540℃.
After homogenization treatment at 400°C and hot rolling at 400°C, cold rolling at 400°C and continuous annealing furnace.
After intermediate annealing at 50° C. (without holding), finish cold rolling was performed at a plate thickness reduction rate of 80% to obtain an alloy plate with a thickness of 0.301.

Table 1 The mechanical properties of the alloy plate thus obtained were investigated.

Next, the surface of the alloy plate with a thickness of 0.30 mIIl was
After chemical etching with a 10% aqueous sodium hydroxide solution, neutralization cleaning was carried out in 20% nitric acid at a temperature of 20°C.
% nitric acid electrolyte, the current density is 3゜A/da+', 50
AC electrolysis was performed at ℃ for 10 seconds.

After cleaning the surface by immersing it in a 50°C aqueous solution of 15% sulfuric acid for 3 minutes, an oxide film of 3 g/dm 2 was formed at a bath temperature of 30°C in an electrolytic solution containing 20% sulfuric acid as the main component. .

The following photosensitive layer was provided on the thus prepared sample so that the dry coating amount was 2.5 g/m'.

Ester compound of naphthoquinone (1,2)-diazide-(2)-5-sulfonic acid chloride and resorcinol-benzaldehyde resin 1 part by weight Phenol, m-p-mixed cresol and formaldehyde copolycondensation resin 3.5 parts by weight 2 -Trichloromethyl-5-[β (2'-benzofuryl)vinyl] 1.3.4-oxadiazole 0.03 parts by weight Victoria Pure Blue BOH (manufactured by Hodegaya Chemical) 0.1 parts by weight p-butylphenol 0-naphthoquinonediazide sulfonic acid ester of benzaldehyde novolac resin 0.05 parts by weight Methyl cellosolve 27 parts by weight A 3 kW metal halide lamp was used to expose for 50 seconds at a distance of 1 m, and the temperature was heated to 25°C with a 4% sodium metasilicate aqueous solution.
, developed for 45 seconds, washed with water, dried, and gummed to obtain a lithographic printing plate.

These printing plates were attached to an offset printing machine KOR, and stains (ink stains) in non-image areas and printing durability were examined. The pit pattern due to electrochemical roughening was observed using an electron microscope (S
The surface was observed using EM).

The above results are shown in Table 2.

Table 2 O Fine, slightly distorted Δ Fine bit + coarse bit, or with pit distortion ×
In the case of invention examples No. 1 to 4 with coarse pits or significant pit distortion, the tensile strength was 14 kgf'
/sa+2 or more, the pit pattern is fine and circular, and the number of prints is as high as 90,000 to 100,000 sheets, and the printing durability is good, and there is little ink stain.

Comparative Examples No. 5 had low Fe content, so the strength was low, the pit pattern was somewhat poor, and the number of sheets printed was small. N
Samples o and 6 had a poor pit pattern due to a large amount of Fe, and the number of prints was small.

No. 7 had low strength due to low Si content, had a somewhat poor pit pattern, and had a small number of prints.

No. 8 has a lot of Si, so there is a lot of ink stain.

No. 9 has a small amount of Cu, so the number of sheets printed is small.

No. IO has a large amount of Cu, resulting in poor pit patterns and a small number of printed sheets. No. 11 is [Ti (%)]
<1.28 [Ga (%)] -0,015, so the pit pattern is somewhat poor and the number of printed sheets is small.

No. 12 had a somewhat poor pit pattern due to a large amount of Ti, and the number of prints was small.

No. 13 had a poor pit pattern due to the large amount of Ga, and the number of prints was small.

Example 2 Next, in order to clarify the influence of the amounts of Ti and Ga, alloys No. 14 to No. 32 shown in Table 3 were melted and cast.
Thickness 500a+m, width 1000m+n with both sides facing up
.

An ingot with a length of 3,500 mm was homogenized at 580°C, heated to 410°C and hot rolled, then cold rolled and heated to 480°C in a continuous annealing furnace.
After intermediate annealing (without holding time), plate thickness reduction rate %
Finish cold rolling was performed to obtain an alloy plate with a thickness of 0.30+ nm.

Table 3 The alloy plate thus obtained was examined for mechanical properties, pit pattern, number of prints (printing durability), and ink stain in exactly the same manner as in Example 1. The results are shown in Table 4.

Table 4 Invention examples Nos. 14 to 25 had high strength, good pit patterns, a large number of prints, and little ink stain. In the case of Comparative Examples No. 2B to 32, (T i (%)
] <1.2 X [G a (X)] −(1,01
5, the pit pattern is slightly poor to poor, and the number of printed sheets is small.

The pit patterns of No. 2, No. 11 in Example 1 and No. 29 of Example 2 are shown in FIG. 1 (magnification: 1
500 times). In the case of No. 2, the bit is fine and circular. In the case of No. 11, the bit is distorted into a slightly half-moon shape, and in the case of No. 29, the bit is significantly distorted.

Next, from the results of No. 1 to 4, No. 11 to 13 of Example 1 and No. 14 to 32 of Example 2, the amount of Ti and G
The relationship between the amount of a and the pit pattern is shown in FIG. A region with a good pit pattern is expressed by the following equation.

[Ti (%)] ≦0.1O (Ga (%)) ≦0.04 [T i (%) ] ≧1.2 X [Ga (%)
] -0,015 Example 3 Next, in order to see the influence of manufacturing conditions, No. 1 of Example 1
As shown in Table 5, for alloys No. 4 to 4, the homogenization temperature, hot rolling heating temperature, intermediate annealing method (continuous furnace or batch furnace), and plate thickness reduction rate during final cold rolling were varied to achieve 0. 3
An alloy plate with a thickness of 0 mm was obtained. Then, in the same manner as in Example 1, mechanical properties, pit patterns, number of printed sheets (printing durability), and ink stains were examined. In addition, streaks on the surface of the lithographic printing plate were also observed.

The results are shown in Table 6.

Table 6 Continuous furnace: Temperature 490°C, holding time 0 seconds No, IA, 2A, 3A, 4A, IE
, 2E.

In the case of 3E and 4E, the strength is high, the pit pattern is good, the number of prints is large, the streak is good, and there is little ink stain. In the case of No, IB, 2B, 3B, 4B,
Due to the high homogenization temperature, there is a slight amount of ink staining. N
In the case of I C-2Cs3C, 4C, the pits were slightly distorted due to the low homogenization temperature, and the number of printed sheets was somewhat small. In the case of No., ID, 2D, 3D, and 4D, the heating temperature of hot rolling is high, so that streaks due to a striated non-uniform structure occur. No, IF.

In the case of 2F, 3F, and 4F, the strength is low because the plate thickness reduction rate during finish cold rolling is low.

As mentioned above, it is desirable that the homogenization treatment temperature is 450 to 600°C, the heating temperature of hot rolling is 350 to 600°C, and the plate thickness reduction rate of final cold rolling is 50% or more.

Further, intermediate annealing may be performed in a batch furnace or a continuous furnace. The optimal conditions for each are as described above.

[Effects of the Invention] The present invention is configured as described above, and the aluminum alloy support for flat-veined printing plates has sufficient strength, so that plate cracking does not occur due to electrochemical roughening. Since the pits are fine and uniform, it has excellent printing durability and has the remarkable effect of being excellent in stain resistance.

[Brief explanation of drawings]

Figure 1 (a), (b), and (c) are Example No. 2.11.2
Electron micrograph showing the metal surface structure of No. 9, Figure 2 is Ti
A graph showing the relationship between the amount of Ga, the amount of Ga, and the pit pattern is shown.

Claims (3)

[Claims] (1) Fe: 0.1 to 1.0% (weight%, same below),
Si: 0.03-0.2%, Cu: 0.005-0.0
5%, Ti: 0.1% or less, Ga: 0.04% or less, and the remainder is Al and unavoidable impurities, and the relationship between Ti and Ga is [Ti (%)] ≧ 1.2 × [ Ga (%)] -0.015
An aluminum alloy material for lithographic printing plates, characterized by: (2) Fe: 0.1-1.0%, Si: 0.03-0.
2%, Cu: 0.005-0.05%, Ti: 0.1%
Hereinafter, Ga: 0.04% or less is included, remaining Al and unavoidable impurities, and the relationship between Ti and Ga is [Ti (%
)]≧1.2×[Ga(%)]−0.015 An aluminum alloy ingot was homogenized at 400 to 600°C, heated to 350 to 600°C, and hot rolled. rear,
A method for producing an aluminum alloy plate for lithographic printing plates, which comprises performing cold rolling, intermediate annealing, and final cold rolling with a plate thickness reduction rate of 50% or more. (3) A support for a lithographic printing plate, which is obtained by roughening the surface of the aluminum alloy material obtained according to claim (2) by subjecting it to surface treatment.