JPH1161364A - Manufacture of aluminum alloy support for lithographic printing plate and aluminum alloy support for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which a roughened surface without streaks and surface roughness which has excellent property for surface treatment in electrochemical surface roughing treatment as an aluminum alloy support for lithographic printing plates is obtained and by which a printing plate which is excellent in fouling property in ink and high in strength after burning is obtained. SOLUTION: After a DC casting (semicontinuous casting) of an aluminum alloy consisting of 0.20-0.50% Fe, 0.05-0.15% Si and 5-30 ppm Cu and the balance Fe with inevitable impurities, hot rolling is started at 450-550 deg.C and the to rolling is executed so that hot-rolling finished temp. (T deg.C) satisfies the next formula in accordance with the amount (X wt.%) of Fe and amount (Y wt.%) of Si. 290-100Y<=T<=320+33X+100Y. After that, after cold rolling of >=30%, intermediate annealing is executed at 430-580 deg.C and the final cold rolling is executed. The alloy containing 500-300 ppm Mg other than each component is treated by a similar process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy support used for a lithographic printing plate, and more particularly to a lithographic printing plate suitable for electrochemical surface roughening treatment and having excellent post-burning strength and ink stainability. The present invention relates to an aluminum alloy support.

[0002]

2. Description of the Related Art Generally, as a lithographic printing plate (including an offset printing plate), a surface of a support made of an aluminum alloy is subjected to a surface roughening treatment, and then, if necessary, to a surface treatment such as an anodizing treatment. It is also known that a so-called PS plate is formed by applying and drying a photosensitive paint. When this is actually used for printing, a plate making process such as image exposure, development, and gumming is performed on the PS plate. Usually it is applied. In the process of the plate making process, the photosensitive layer which remains undissolved by the development process forms an image area, while the portion where the photosensitive layer is removed and the aluminum surface underneath is exposed is water-receptive due to its hydrophilicity. And a non-image portion.

[0003] As such a support for lithographic printing,
Generally, an aluminum alloy plate that is lightweight and has excellent surface treatment properties, workability, and corrosion resistance is used. Conventionally, as such an aluminum alloy plate, JIS A1
An aluminum alloy rolled plate having a plate thickness of about 0.1 to 0.5 mm, which is made of 050, JIS A1100, JIS A3003, or the like, is used. Further, such an aluminum alloy rolled plate has a surface roughened by one or more of a mechanical method, a chemical method, and an electrochemical method, and then subjected to an anodizing treatment and applied to a printing plate. Is usually the case. Specifically, an aluminum lithographic printing plate which has been sequentially subjected to a mechanical surface roughening treatment, a chemical etching treatment and an anodic oxide film treatment described in JP-A-48-49501, or JP-A-51-146234. An aluminum lithographic printing plate which has been subjected to the electrochemical treatment, post-treatment, and anodizing treatment described in JP-B-48-28123.
Aluminum lithographic printing plate which has been subjected to chemical etching and anodic oxidation treatment in this order, or which has been subjected to a mechanical surface roughening treatment followed by a treatment described in JP-B-48-28123. It has been known.

When the above-mentioned aluminum alloy support is actually used for printing, it is necessary to apply an appropriate photosensitive coating material after the surface roughening treatment and the anodic oxidation treatment as described above, and to dry it. Performing plate making processes such as exposure and development to make a printing plate, wrapped around a cylindrical plate cylinder of the printing press and fixed, and attached ink to the image area in the presence of fountain solution, after transferring to a rubber blanket, Printing on paper is performed. Further, in this case, printing is generally performed on a large number of sheets from one printing plate.

[0005]

The aluminum alloy support for a lithographic printing plate as described above is required to have the following characteristics.

That is, firstly, fine irregularities can be uniformly formed by the surface roughening treatment, and the surface after the surface roughening treatment has irregular roughness or streak-like unevenness along the rolling direction (generally, unevenness). This is called "streaks").

As the roughening treatment, it is conceivable to apply a mechanical roughening treatment, an electrochemical roughening treatment or a chemical roughening treatment as described above. It is considered difficult to satisfy such requirements only by mechanical surface roughening treatment alone or chemical surface roughening treatment alone. It is common to apply a combination of a surface roughening treatment and a mechanical roughening treatment or a chemical roughening treatment.
According to the electrochemical surface roughening treatment, various rough surfaces can be obtained by selecting an electrolytic bath solution and electrolysis conditions, and a uniform and fine rough surface can be obtained. The aluminum alloy support for a printing plate has particularly good surface roughening properties by electrochemical surface roughening treatment, that is, fine irregularities can be uniformly formed by the electrochemical surface roughening treatment. It is desired that surface roughness and streak do not occur.

Second, it is desired that the ink has a property that ink does not easily adhere to a non-image portion during printing. That is, if ink adheres to the non-image portion, the non-printed portion of the paper surface of the printed matter becomes stained with the ink. Therefore, it is necessary that the ink does not adhere to the non-image portion. It is called.

Third, generally, the aluminum alloy support for a printing plate is subjected to a heat treatment called a burning treatment at 200 to 300 ° C. for about 3 to 10 minutes in order to improve the printing durability. However, it is required that the material be not softened by the burning and have high strength after burning. That is, a printing plate is generally wound around a cylindrical plate cylinder of a printing press and both ends are usually fixed mechanically by a clamp. However, when the strength of the printing plate is insufficient, both ends of the printing plate are generally fixed. Since the fixed portion is deformed or destroyed to cause troubles such as printing misalignment, or the repeated stress applied to the bending portion at both ends of the printing plate causes a lip to be cut and printing becomes impossible, so that the strength after the burning process is high. This is also an important performance as a printing plate support.

However, conventional general aluminum alloy plates for a printing plate support have advantages and disadvantages, respectively.
It has been difficult to simultaneously and sufficiently satisfy all of the various characteristics described above. That is, when a conventional general aluminum alloy support for a printing plate is used, the surface roughened by the electrochemical surface roughening treatment may be roughened, streaks may be generated, or the ink stainability may be reduced. There are problems such as poor adhesion of the ink to the non-image portion and further reduction of the printing plate strength due to burning.

The present invention has been made in view of the above circumstances, and has a good surface roughening property (surface treatment property) by electrochemical surface roughening treatment, so that the roughened surface can be roughened or streaked. Aluminum for lithographic printing plates that can form a uniform and fine rough surface without ink blemishes, has good ink stainability, hardly stains non-image areas during printing, and has high strength after burning. It is an object to provide an alloy support.

[0012]

In order to solve the problems described above, the present inventors have conducted detailed experiments and studies on the component composition and manufacturing process of an aluminum alloy support for a lithographic printing plate. In addition to appropriately setting the chemical composition of the above, the hot rolling conditions, especially the finishing temperature, are appropriately determined according to the composition of the components, and the intermediate annealing conditions, etc. are also appropriately determined, thereby simultaneously satisfying the above-mentioned various properties. The present inventors have found that an obtained aluminum alloy support can be obtained, and have accomplished the present invention.

More specifically, the method for producing an aluminum alloy support for a lithographic printing plate according to the first aspect of the present invention comprises the steps of:
0.50%, Si 0.05-0.15%, and Cu
An alloy containing 5-300 ppm, the balance being Al and unavoidable impurities, was subjected to hot rolling after casting by 45%.
Starting at a temperature within the range of 0 to 550 ° C., and the hot rolling finish temperature (T ° C.) is determined by the Fe content (X wt%) and the Si content.
According to the amount (Ywt%), the hot rolling is completed so that 290−100Y ≦ T ≦ 320 + 33X + 100Y is satisfied and the finished plate thickness is in the range of 2 to 6 mm, and the cold rolling is performed at a rolling reduction of 30% or more. , And then subjected to intermediate annealing at a temperature within the range of 430 to 580 ° C., and then subjected to final cold rolling to obtain Fe
It is characterized in that a final plate having a solid solution amount of 5 ppm or more is obtained.

The method for producing an aluminum alloy support for a lithographic printing plate according to the second aspect of the present invention is characterized in that:
0%, Si 0.05-0.15%, Cu 5-300pp
m, containing 50 to 3000 ppm of Mg and the balance consisting of Al and unavoidable impurities, starting hot rolling after casting at a temperature in the range of 450 to 550 ° C, and finishing hot rolling (T ° C), the amount of Fe (Xwt
%) And the amount of Si (Ywt%), hot rolling is completed so that 290-100Y ≦ T ≦ 320 + 33X + 100Y is satisfied and the finished plate thickness is in the range of 2 to 6 mm, and the rolling reduction is 30% or more. , And then subjected to intermediate annealing at a temperature in the range of 430 to 580 ° C., and then to final cold rolling to obtain Fe.
It is characterized in that a final plate having a solid solution amount of 5 ppm or more is obtained.

Further, the invention of claim 3 defines an aluminum alloy support for a lithographic printing plate having an Fe solid solution amount of 5 ppm or more obtained by the production method of claim 1.

According to a fourth aspect of the present invention, there is provided an aluminum alloy support for a lithographic printing plate having an Fe solid solution amount of 5 ppm or more obtained by the production method of the second aspect.

Here, the reasons for limiting the components of the aluminum alloy support for planographic printing plates according to the present invention will be described.

Si: If Si is less than 0.05%, the surface treatment properties are poor, the uniformity of the rough surface after the electrochemical surface roughening treatment is poor, and a high-purity raw metal material is required. Since high cost is incurred, practicality is impaired in terms of economy. On the other hand, if the content of Si exceeds 0.15%, the color tone after the surface-roughening treatment becomes too blackish to impair the commercial value, and also the uniformity of the rough surface is reduced and the ink stainability is reduced. .
Therefore, the Si content needs to be in the range of 0.05 to 0.15%. The amount of Si is related to the ease of recrystallization after hot rolling. If the amount of Si is small, the temperature for recrystallization at the stage after hot rolling increases.

Fe: If Fe is less than 0.20%, the roughened surface by the electrochemical surface roughening treatment becomes non-uniform, so that the roughened surface is liable to be roughened or streaked, and a high-purity raw metal material is used. Is required, which leads to an increase in cost, which impairs economic efficiency. On the other hand, if the Fe content exceeds 0.50%, the ink smearing property is reduced, and the color tone after the surface roughening treatment is too blackish, which impairs the commercial value. Therefore, Fe is 0.20-0.
It must be within the range of 50%. The amount of Fe also relates to the ease of recrystallization after hot rolling. If the amount of Fe is small, recrystallized grains at the stage after hot rolling tend to be large. Note that Fe needs to have a solid solution amount of 5 ppm or more in the final plate. That is, the solid solution amount of Fe is related to the burning characteristics in the final plate, and the smaller the solid solution amount of Fe, the easier it is to soften. In particular, when the amount of Fe solid solution is less than 5 ppm, the material is softened by the heating for the burning treatment, and the strength after the burning treatment is reduced.

Cu: Cu refines the pits formed by the electrochemical surface roughening treatment and improves the surface treatment property. Cu content is 5
If the amount is less than 0.3 ppm (0.0005 wt%), the effect of miniaturizing the pits is insufficient, while the Cu content is 300 ppm (0.
If it exceeds 0.3% by weight, the uniformity of the rough surface due to the electrochemical surface roughening treatment will be reduced, and the ink smearing property will be reduced. Therefore, the Cu content is set in the range of 5 to 300 ppm.

Mg: Mg is effective for improving the ink smearing property when the ink smearing property is likely to be reduced due to other conditions, and the aluminum alloy for a lithographic printing plate according to the invention of claim 2 or claim 4. Actively added in the support. Mg content is 50ppm (0.005wt%)
If the amount is less than 3, the effect of improving the ink stainability cannot be sufficiently obtained. On the other hand, if the amount of Mg exceeds 3,000 ppm (0.30% by weight), electrochemical surface roughening becomes unstable, and good print quality cannot be obtained. Also, the strength of the material is too high,
Since the bending property decreases and the line passing property decreases, the amount of Mg when adding Mg is 50 to 300.
It was within the range of 0 ppm.

Other than the above elements, Al and unavoidable impurities may be basically used. However, in general aluminum alloys, a small amount of Ti may be added alone or in combination with a small amount of B in order to refine the ingot crystal structure and prevent texture and streaks of the rolled sheet. Also in the aluminum alloy used for the lithographic printing plate support of the present invention, 0.003 to 0.05% of Ti may be added alone or in combination with 1 to 50 ppm of B. If the Ti content is less than 0.003%, the B content is 1 p.
At less than pm, the above effects cannot be obtained. On the other hand, when the Ti content exceeds 0.05%, the effect of adding Ti is saturated and the economy is impaired, and when the B content exceeds 50 ppm, the effect of adding B is reduced. In addition to saturation, linear defects due to coarse TiB ₂ particles are likely to occur.

As impurities, the amount of impurities corresponding to JIS 1050 (Mn 0.05% or less, Zn 0.05% or less,
If the total is about 0.05% or less), the properties of the aluminum alloy for a lithographic printing plate support will not be impaired. In the first and third aspects of the invention,
Although Mg is not added as an active alloying element, it is a matter of course that it is allowed to contain less than 50 ppm of Mg as an impurity.

Next, the manufacturing process in the method for manufacturing an aluminum alloy support for a lithographic printing plate according to the present invention will be described.

First, an aluminum alloy having the above-described composition is cast by a DC casting method or the like according to a conventional method. The obtained ingot was heated prior to hot rolling, subjected to hot rolling, and subsequently subjected to cold rolling, then subjected to intermediate annealing, and further subjected to final cold rolling. To a rolled plate having a plate thickness of about 0.10 to 0.50 mm.

Here, the hot rolling start temperature is 450-55.
The temperature must be within the range of 0 ° C. Hot rolling start temperature is 4
If the temperature is lower than 50 ° C., it becomes difficult to secure a temperature required for hot rolling required for recrystallization as described later, and segregation of the ingot structure remains, so that ink stains are likely to occur. On the other hand, if the hot rolling start temperature exceeds 550 ° C., the recrystallized grains are coarsened during hot rolling, and the surface is likely to be roughened during electrochemical graining treatment.

The temperature at which hot rolling is performed is extremely important in the present invention. That is, in the case of the method of the present invention, recrystallization is performed even during the intermediate annealing, but the roughened surface after the electrochemical surface roughening treatment in the final plate is uniform, free of streak generation and has no surface roughness. In order to obtain a surface, it is necessary that the surface of the rolled sheet is once recrystallized even in the stage of hot rolling before intermediate annealing, and that the recrystallized structure is uniform and fine. In addition, it is necessary to set the hot rolling completion temperature in an appropriate temperature range according to the Fe content and the Si content of the alloy. In particular,
Proceeding with recrystallization by the retained heat of the hot-rolled sheet itself after hot rolling is effective in preventing streaks from being generated during the electrochemical surface roughening treatment of the final sheet. If the recrystallized grains after rolling become coarse, surface roughness is likely to occur during electrochemical surface roughening treatment. Therefore, in order to obtain a surface having no streak and no roughness as a roughened surface after the electrochemical surface roughening treatment, it is necessary to recrystallize uniformly and finely after hot rolling. . Since the chemical composition of the material alloy, particularly the Fe content and the Si content, strongly influences the recrystallization of the rolled sheet after hot rolling, the appropriate recrystallization state as described above in the state after hot rolling. In order to obtain an appropriate roughened surface by electrochemical surface roughening treatment, the hot rolling completion temperature T (° C.) is set by changing the Fe amount (X wt%) and the Si amount (Y wt%) of the material alloy. ), It is necessary to set the temperature range so as to satisfy the following equation (1). 290−100Y ≦ T ≦ 320 + 33X + 100Y (1)

Here, the hot rolling completion temperature T is expressed by the following equation (1).
If it is less than the left side (290-100Y), the surface layer is not sufficiently recrystallized by hot rolling, and streaks are likely to be generated by the final electrochemical surface roughening treatment. On the other hand, the hot rolling completion temperature T is equal to (320 + 33X
If it exceeds (+ 100Y), recrystallized grains become coarse due to hot rolling, and the surface is likely to be roughened by electrochemical surface roughening treatment on the final sheet. In the case of the method of the present invention, cold rolling is performed after hot rolling, intermediate annealing is performed, and recrystallization is performed again. During this intermediate annealing, crystal grains are made more uniform, but this alone is not sufficient. If the hot-rolling temperature is out of the range of the above-described formula (1), the streaks can be obtained by electrochemical graining of the final sheet even if the uniformization of crystal grains is advanced by intermediate annealing. The problem of heat and roughness occurs.

The thickness of the hot-rolled sheet is 2-6.
mm. If the thickness of the hot-rolled sheet is less than 2 mm, it is difficult to keep the hot-rolling finishing temperature within the range of the formula (1). No longer.

After the completion of hot rolling and before intermediate annealing, cold rolling (primary cold rolling) is performed. The rolling reduction of this primary cold rolling is at least 30% or more, preferably 50% or more. If the cold rolling reduction before the intermediate annealing is less than 30%, the recrystallized grains during the intermediate annealing become coarse or no recrystallization occurs during the intermediate annealing, so that the final sheet is subjected to electrochemical graining treatment. Roughness occurs on the roughened surface.

After the first cold rolling, intermediate annealing is performed.
This intermediate annealing needs to be performed in a temperature range of 430 to 580 ° C. If the intermediate annealing temperature is lower than 430 ° C., the plate tends to soften during the burning process, and the strength of the printing plate may be reduced. On the other hand, when the intermediate annealing temperature is 580
If the temperature exceeds ℃, the crystal grains become coarse and the electrochemically roughened surface of the final sheet becomes rough. As the intermediate annealing, either batch annealing with a slow heating rate or continuous annealing with rapid heating may be applied. The holding time of the intermediate annealing is generally 30 minutes or more in the case of batch annealing, while no holding or 5 minutes or less is sufficient in the case of continuous annealing.

The final cold rolling reduction after the intermediate annealing is not particularly limited, but may be generally about 10% to 80%.

Next, a processing method for converting the aluminum alloy support for a lithographic printing plate obtained as described above into a lithographic printing plate will be described in detail. Note that the methods described below are representative examples to the fullest, and are of course not limited to these methods.

First, in order to remove oils, fats, rust, dust and the like adhering to the surface of the aluminum alloy base plate, it is desirable to carry out a cleaning treatment with trichlene, caustic soda or the like.
When alkali etching is performed using caustic soda or the like, a desmutting process (for example, a process of immersing in 10 to 30 wt% sulfuric acid or nitric acid) for removing generated smut is performed. The surface subjected to the cleaning treatment is subjected to a roughening treatment. As the surface roughening method, there are a mechanical surface roughening method, an electrochemical surface roughening method, and a chemical surface roughening method. As a mechanical surface roughening method, a brush grain method using a rotating nylon brush and an abrasive (alumina, silica sand, or the like) is generally used. As the electrochemical surface roughening method, 2 to 40 g / l
In general, an electrolytic treatment is performed at a temperature of 20 to 70 ° C. in an aqueous solution containing hydrochloric acid or an aqueous solution containing 2 to 40 g / l of nitric acid. An acid, an amine, a carboxylic acid and the like may be contained. In the electrochemical surface roughening method, when the electrolyte concentration is 2 g / l or less, roughening becomes difficult, and the surface concentration becomes 40 g / l.
In such a case, the surface becomes uneven and the surface becomes unsuitable as a printing plate. As the current waveform used for the electrochemical surface roughening, commercial alternating current, sine wave alternating current, rectangular wave, trapezoidal wave, or the like is used, and the current density is preferably in the range of 10 to 100 A / mm ² . The rough surface shape by electrochemical surface roughening treatment can be adjusted by controlling various conditions such as electrolyte composition, temperature, current density, electrolysis waveform, electricity quantity, and electrolyte flow rate. By controlling, desired printing characteristics can be easily obtained. On the other hand, as the chemical surface roughening method, a method of etching the surface with caustic soda, sodium fluoride, or the like can be applied. The residue adhering to the surface thus roughened can be removed by the method described in US Pat. No. 3,834,998. Although any of the above methods may be basically used as the surface roughening method, the electrochemical surface roughening treatment is particularly optimum for the alloy having the component composition used in the present invention.

The surface roughened as described above is subjected to anodic oxidation by a known method. Specifically, direct current in an electrolyte solution containing an aluminum salt in sulfuric acid, phosphoric acid, oxalic acid, chromic acid, amide sulfonic acid, etc.
Anodizing treatment may be performed using AC, AC / DC superposition, DC pulse, or the like. The electrolyte concentration at this time is 1 to 80 wt%,
The temperature ranges from 5 to 70 ° C., and the current density ranges from 0.5 to 60 A /
dm ² , and the weight of the oxide film is 0.5 to 5 g / m 2.
The range of ² is preferred.

For anodized aluminum plate, US Pat. No. 2,714,066, British Patent 1,203,447 or US Pat.
The hydrophilic treatment may be performed by the method described in the specification. If necessary, organic sulfonic acids described in JP-A-63-145092 and JP-A-63-145092 may be used.
No. 92, a compound containing a carboxylic acid and a phosphonic acid group, a compound described in JP-A-3-261592, a compound having one amino group and one oxyacid group of phosphorus, and a compound described in JP-A-3-215.
No. 095 as a subbing layer
30 mg / m ² can be provided.

In order to further form a lithographic printing plate, it is necessary to provide a photosensitive layer on the surface. As this photosensitive layer, any of the following (1) to (4) may be applied. .

(1) Photosensitive layer containing novolak resin mixed with O-naphthoquinonediazidesulfonic acid ester and phenol / cresol For example, US Pat. Nos. 2,766,118 and 27670
No. 92, No. 3636709, No. 3759711
And the compounds described in U.S. Pat. No. 4,028,111 or British Patent 1,940,043 are useful.

(2) Photosensitive layer having diazo resin and water-insoluble and lipophilic polymer compound For example, a diazo resin of a condensate of P-diazodiphenylamine with formaldehyde or acetaldehyde and hexafluorophosphate is preferable. is there. Other,
U.S. Pat. No. 3,300,309, Japanese Patent Publication No. 54-19773
The diazo compounds described in the above item are also useful.

(3) Photosensitive Layer Containing Photodimerizable Photosensitive Layer Composition and Photopolymerized Photosensitive Composition The photodimerizable photosensitive layer composition is disclosed in US Pat.
No. 41 and the polymer having a maleimide group in the side chain or main chain described in German Patent No. 2626769 are preferable. As the photopolymerizable photosensitive layer composition, a polymer having a cinnamyl group, a cinnamoyl group, a chalcone group or the like in a side chain or a main chain is preferable. For example, there are photosensitive polyesters described in U.S. Pat. No. 3,030,208 and U.S. Application No. 828,455. Also,
JP-A-60-1 obtained by solubilizing these polymers with alkali
The polymers described in 91244 are also useful.

(4) Photosensitive layer for electrophotography For example, US Pat.
No. 61550, JP-A-60-186847, JP-A-60-186847
The ZnO photosensitive layer used for the electrophotographic photosensitive layer described in the specification of Japanese Patent No. 1-238063 may be used.

In these photosensitive layers, if necessary, binders described in US Pat. Nos. 4,028,111 and 3,751,257, dyes described in JP-A-62-293247, JP-A-2-96756, and JP-A-2-96756 can be used. Representative examples include a sensitizing agent described in JP-A-55-527, a nonionic surfactant described in JP-A-62-251740, and O-naphthoquinonediazide-4-sulfonyl chloride and trihalomethyloxathiazole. JP 5
A photoacid generator disclosed in JP-A-3-36223 and JP-A-63-58440 may appropriately add an image visualizing agent after exposure. Here, the photosensitive layer provided on the aluminum plate has a weight of 0.8 to 6 g after drying.
/ M ² .

JP-A-55-12974 and JP-A-58-18263, which are formed on the photosensitive layer coated and formed as described above, by projections provided independently of each other.
A mat layer described in No. 6 may be provided. Further, in order to prevent the photosensitive layer from being scratched when the photosensitive layer is superimposed on the back surface with respect to the surface on which the photosensitive layer is applied, a polymer having a glass transition point of 20 ° C. or more or an organic metal described in JP-A-6-35174 is disclosed. A method of coating a salt or the like with an inorganic oxide by hydrolysis or the like may be applied.

The photosensitive lithographic printing plate (PS plate) prepared as described above is exposed to an image and then exposed to light according to US Pat.
No. 4, No. 4,186,006, JP-A-59-84241.
No. JP-A-57-192952 or JP-A-62-192.
It is developed and gummed by the method described in the specification of Japanese Patent No. 24263 and fixed to a plate cylinder for printing.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION

[0046]

EXAMPLES Aluminum alloys having the chemical composition indicated by alloy symbols A to E in Table 1 were melted and subjected to DC casting (semi-continuous casting) to 450 mm × 1200 mm × 3500 m.
m was cast. The ingot was subjected to face milling of 10 mm on each side, then hot-rolled under the conditions shown in production numbers 1 to 11 in Table 2, further subjected to primary cold rolling, and then subjected to intermediate annealing (note : Production No. 4 was subjected to intermediate annealing without primary cold rolling), and was finally cold-rolled to finish a lithographic printing plate support blank having a thickness of 0.3 mm. Table 2 shows the result of examining the amount of Fe solid solution after the final cold rolling.

[0047]

[Table 1]

[0048]

[Table 2]

For each of the blanks obtained under the process conditions shown in the production numbers 1 to 11 in Table 2, 25 wt.
% Of the suspension was subjected to a brush grain treatment using a rotating nylon brush so that the surface roughness became 0.6 μm. The surface was pre-etched in a 10% aqueous sodium hydroxide solution at 50 ° C. for 1 minute, followed by 30 A / mm ² in a 1% aqueous nitric acid solution.
The electrolytic surface roughening treatment (electrochemical surface roughening treatment) was performed at a current density of 10 seconds. Continuously, 3% in 5% caustic soda
After washing at 5 ° C. × 10 seconds, 50 ° C. × 2 in 30% sulfuric acid.
Neutralization treatment was performed for 0 seconds. This surface is treated with about 0.
An anodized film of 7 μm was formed. The following photosensitive layer was provided on this aluminum plate so that the dry weight after coating was 2 g / m ² .

Components of photosensitive layer Ester compound of naphthoquinone (1,2) -diazide- (2) -5-sulfonic acid chloride and resorcin-benzaldehyde resin: 1 part by weight Phenol, m-, p-mixed cresol and formaldehyde Copolycondensate 3.5 parts by weight 2-trichloromethyl-5- [β- (2-benzofuryl) vinyl] -1,3,4 "-oxadiazole
0.03 parts by weight Victoria Viewable-BOH (Hodogaya Chemical)
... 0.1 parts by weight O- of p-butylphenolaldehyde novolak resin
Naphthoquinone azidosulfonic acid ester 0.05 parts by weight Methylcellosolve 27 parts by weight

The photosensitive lithographic printing plate obtained as described above was exposed for 50 seconds at a distance of 1 m using a 3 kw metal halide lamp, developed with a 3% aqueous sodium metasilicate solution at 25 ° C. for 45 seconds, After washing, drying and gumming, a lithographic printing plate was obtained. The original plate thus obtained was attached to a printing press and a printing test was performed.

The lithographic printing plate support according to the present invention and the lithographic printing plate support according to the comparative example were subjected to surface treatment when mechanical roughening, pre-etching, and electrochemical roughening were performed as described above. As a property, streaks and surface roughness were investigated, and as a softening resistance to the burning treatment, a heat treatment at 300 ° C. for 7 minutes corresponding to the burning treatment was performed, and the strength after that was examined. Further, with respect to each of the finally obtained printing plates, ink stains in the non-image areas were examined. Table 3 shows the results. In Table 3,
Streaks and surface roughness with respect to surface treatment properties were evaluated by visual observation as "Good", "Good", "Medium", "Poor". Regarding the ink stainability, the presence or absence of ink stains in the non-image area was visually determined.

[0053]

[Table 3]

As shown in Table 3, examples of the present invention in which the composition of the alloy satisfies the conditions defined in the first or second aspect of the present invention and the manufacturing process also satisfies the conditions defined in the present invention (production number 1, In the case of (6, 9), no streaks and surface roughness occur after the electrochemical surface roughening treatment, the surface treatment in the electrochemical surface roughening treatment is excellent, and the strength after the burning treatment is high. Further, it is clear that the ink stainability is excellent.

On the other hand, in the comparative example of Production No. 2, although the composition of the alloy satisfies the conditions defined in the first aspect of the present invention, the hot rolling start temperature is low and the hot rolling rise temperature is expressed by the formula ( Since it is lower than the lower limit of 1), streak is generated, and ink smearing property is poor. In addition, since the intermediate annealing temperature is too low and the amount of Fe solid solution in the final plate is less than 5 ppm, the burning treatment is remarkable. It has softened.

In the comparative example of Production No. 3, although the component composition of the alloy satisfies the condition defined in the first aspect of the present invention, the hot rolling starting temperature is too high and the hot rolling rising temperature is determined by the formula (1). ), The surface roughness was caused by the electrochemical surface roughening treatment.

The comparative example of Production No. 4 is an example in which the composition of the alloy satisfies the conditions defined in the first aspect of the present invention, but the cold rolling was not performed before the intermediate annealing. Streak and surface roughening were caused by the electrochemical surface roughening treatment.

In the comparative example of Production No. 5, although the composition of the material alloy satisfies the condition defined in the first aspect of the present invention, the intermediate annealing temperature is low and the amount of Fe in the final sheet is less than 5 ppm. As a result, the strength after the burning treatment was reduced.

Further, Production No. 7 is a comparative example in which the composition of the alloy satisfies the conditions defined in the second aspect of the invention, but the hot rolling finish temperature is lower than the lower limit defined by the formula (1). In this case, streaks occurred due to the electrochemical surface roughening treatment.

Production No. 8 is a comparative example in which the composition of the alloy satisfies the conditions defined in the second aspect of the invention, but the hot-rolling temperature exceeds the upper limit defined by the formula (1). In this case, the surface was roughened by the electrochemical surface roughening treatment.

On the other hand, the production number 10 indicates that the amount of Fe, the amount of Si,
This is a comparative example using a comparative alloy in which the amount of u and the amount of Mg exceed the respective upper limits of contents specified in the present invention. In this case, the manufacturing process conditions satisfied the process conditions specified in the present invention. The surface roughening treatment resulted in surface roughness, resulting in poor ink stainability.

The production number 11 indicates the amount of Fe, the amount of Si,
This is a comparative example using a comparative alloy in which the Cu content was lower than each content lower limit specified in the present invention. In this case, the manufacturing process conditions satisfied the conditions specified in the present invention, but the electrochemical surface roughening was performed. The treatment resulted in streaks and surface roughness.

[0063]

According to the present invention, not only the component composition is properly determined, but also the manufacturing process, in particular, the hot rolling completion temperature is appropriately determined according to the Fe content and the Si content of the alloy. Excellent surface treatment property in the surface roughening process, it is possible to obtain a lithographic printing plate having a uniform and fine roughened surface without streaks and surface roughness, and also less softening due to burning process. As a result, a lithographic printing plate having high strength after the burning treatment, excellent ink smearing properties, and less ink smear in non-image areas can be obtained.

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ Identification code FI C22F 1/00 683 C22F 1/00 683 385 685Z 686 686A 691 691B 694 694B 694A (72) Inventor Hirokazu Sakaki Yoshida, Haruhara-gun, Shizuoka Prefecture 4000 Machikawajiri, Fujisha Shin Film Co., Ltd. (72) The inventor Hirokazu Sawada 4000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture, Fuji Shashin Film Co., Ltd.

Claims (4)

[Claims] 1. 0.20 to 0.50% of Fe (% by weight, the same applies hereinafter), 0.05 to 0.15% of Si, and
An alloy containing 300 ppm, the balance being Al and unavoidable impurities is used as a material, and hot rolling after casting is performed at 450 to
Starting at a temperature in the range of 550 ° C., and the hot rolling finish temperature (T ° C.) satisfies 290−100Y ≦ T ≦ 320 + 33X + 100Y, depending on the amount of Fe (X wt%) and the amount of Si (Y wt%); The hot rolling is finished so that the finished plate thickness is in the range of 2 to 6 mm, and after cold rolling at a rolling reduction of 30% or more, intermediate annealing is performed at a temperature in the range of 430 to 580 ° C. , And then subjected to final cold rolling to obtain Fe
A method for producing an aluminum alloy support for a lithographic printing plate, wherein a final plate having a solid solution amount of 5 ppm or more is obtained. 2. 0.20 to 0.50% Fe, 0.0% Si
5 to 0.15%, Cu 5 to 300 ppm, Mg 50 to 3
000 ppm, the balance being made of an alloy consisting of Al and unavoidable impurities, and hot rolling after casting from 450 to
Starting at a temperature in the range of 550 ° C., and the hot rolling finish temperature (T ° C.) satisfies 290−100Y ≦ T ≦ 320 + 33X + 100Y, depending on the amount of Fe (X wt%) and the amount of Si (Y wt%); The hot rolling is finished so that the finished plate thickness is in the range of 2 to 6 mm, and after cold rolling at a rolling reduction of 30% or more, intermediate annealing is performed at a temperature in the range of 430 to 580 ° C. , And then subjected to final cold rolling to obtain Fe
A method for producing an aluminum alloy support for a lithographic printing plate, wherein a final plate having a solid solution amount of 5 ppm or more is obtained. 3. An aluminum alloy support for a lithographic printing plate having an Fe solid solution amount of 5 ppm or more, produced by the production method according to claim 1. 4. An aluminum alloy support for a lithographic printing plate produced by the production method according to claim 2 and having an Fe solid solution amount of 5 ppm or more.