JPS62181191A - Production of planographic plate material - Google Patents

Abstract

PURPOSE:To enhance tensile strength and fatigue strength, by using a base obtained by subjecting an aluminum alloy plate having a predetermined alloy composition to a mechanical roughening treatment, an acidic or alkaline solution treatment and a predetermine electrochemical roughening treatment. CONSTITUTION:An aluminum alloy plate containing 0.35-0.9wt% of Mg, 0.05-0.5wt% of Fe, up to 0.2wt% of Si and up to 0.05wt% of Cu, the remainder being Al and unavoidable impurities, is mechanically roughened, is treated with an acidic or alkaline solution, and is electrochemically roughened in an electrolytic solution based on hydrochloric acid or nitric acid to obtain a base. The mechanical roughening may be carried out by a graining method such as a wire brush graining method in which the surface of aluminum is scratched by metallic wires. A photosensitive substance is applied to the base to provide a photosensitive layer, whereby a photosensitive planographic plate can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) Kiwasu 1 relates to a method for producing a lithographic printing original plate formed by coating a photosensitive material on an aluminum alloy support with a roughened surface.

(Prior Art) Conventionally, as a lithographic printing plate, an aluminum plate coated with a photosensitive material is used, which has been subjected to surface treatments such as roughening treatment and anodic oxidation coating treatment. The most widely used of these is the so-called 25 plate, which is coated with a photosensitive material in advance and ready for printing immediately. A printing plate is obtained by subjecting such a lithographic printing plate to plate-making processes such as image exposure, development, water washing, and lacquer application, but the undissolved photosensitive layer due to this development process forms an image area, and the photosensitive layer is removed. It is well known that the exposed aluminum surface underneath is hydrophilic and therefore becomes a water receiving area, forming a non-image area.

As a support for such lithographic printing plates, aluminum plates are generally used, which are lightweight and have excellent surface treatment properties, workability, and corrosion resistance. Conventional materials used for this purpose include JIS
1050 (purity 9g, 5 tons 114% or more pure A1.
JIS 1100 (A-fl, 05-0.211 weight j, % Cu alloy), JIS 3003 (A l-
[ ], 0'li ~ 0.20q'j Soaked %Cu -1,5
It is an aluminum alloy plate with a thickness of 1.1 to 0.81 m, such as 6% Mn alloy), and its surface is processed by mechanical, chemical, or electrochemical methods, or by a combination of tools. The surface is roughened by a process-based surface roughening method, and then subjected to one or more anodic oxidation treatments.

Specifically, an aluminum lithographic printing plate subjected to mechanical roughening treatment, chemical etching treatment, and anodized film treatment described in JP-A-48-4950 f, or JP-A-51-61304. Aluminum lithographic printing plates were sequentially subjected to chemical etching treatment and anodic oxide film treatment as described in the publication, and electrochemical treatment, post-treatment, and anodic oxide film treatment as described in JP-A-54-146234. Aluminum lithographic printing plate, Special Publication Showa 4B
-The electrochemical treatment described in Publication No. 28123,
Aluminum lithographic printing plates are known which have been subjected to a chemical etching treatment and an anodic oxidation coating treatment in that order. By appropriately selecting the photosensitive layer coated on such a support, 1
How about millions of clear prints? ') can be done.

(9, Problem that I am trying to solve) On the other hand, as printing speed has increased with the advancement of printing technology,11 the stress applied to the printing plate mechanically fixed to both ends of the plate cylinder of the printing press has increased. If the increase is unavoidable and the strength is insufficient, this fixed part may become deformed or damaged, causing problems such as printing misalignment, or
Repeated stress applied to the folded portion of a printing plate often causes the plate to break (grip breakage), resulting in poor printing. For this reason, there is a need to develop materials that are superior in strength (specifically, tensile strength and fatigue strength).

Furthermore, as described in detail in JP-A No. 60-215727, when printing a large number of copies, the aluminum support of the printing plate reacts with the damp wood, causing local corrosion.
Ink adheres to this and causes dot-like stains on non-image areas,
There is a problem that it becomes impossible to obtain good printed matter. In order to improve the stain resistance of the non-image area, it is necessary to improve the corrosion resistance of the aluminum support itself and the water retention of the roughened surface.

Therefore, it is an object of the present invention to overcome the two problems mentioned above, and has a tensile strength and fatigue strength of 100%, and does not cause stains in non-image areas even when printing a large number of copies. The purpose is to obtain a lithographic printing plate that gives a lithographic printing plate.

(Means for solving the problem) As a result of intensive research, Nagisa et al. created macro-shaped sand [1] by mechanical roughening treatment on an aluminum alloy plate with a predetermined alloy composition. 3L shows that the above object can be achieved by subjecting the material to acid or alkali solution treatment and predetermined electrochemical roughening treatment, and using this as a support for a lithographic printing original plate and coating a photosensitive substance. Based on this knowledge, we have completed the present invention.

That is, the present invention provides Mg0. :Is~0.9% by weight, Fe
d, mouth s ~ o, s mW:%, 5i11.2 times %
After mechanically roughening an aluminum alloy plate containing 0.05% by weight or less of Cu and unavoidable impurities with the remainder being A, it is treated with an acid or alkaline solution, and then treated with a chloride-based or nitric acid-based solution. The present invention provides a method for producing a lithographic printing original plate, which uses a support that has been electrochemically roughened in an electrolytic solution.

The reason why the composition of the aluminum alloy plate serving as the support in the present invention is limited as described above is as follows. (Hereinafter, 1% means ball amount%.) Mg is 0.35 to 0.9
% range. Mg is mostly dissolved in An and improves tensile strength and fatigue strength without impairing the uniformity of the roughened surface due to electrochemical roughening treatment. If it is less than 0.35%, the tensile strength will be low, and if it exceeds 0.9%, the uniformity of the rough surface will be impaired.

Fe is in the range of 0.05 to 0.5%. Fe has the effect of making the electrolytically roughened surface uniform. Fe combines with other elements in the aluminum alloy, forming A1-Fe system or /IJ
It is an element that forms I-Fe-Si-based eutectic compounds, and these eutectic compounds are effective in making recrystallized grains finer and forming uniformly fine electrolytically rough surfaces. F
If the content of e is less than 0.05%, the effect of refining crystal grains and uniformly refining the electrolytically roughened surface will be small;
If the content exceeds 5%, the electrolytically roughened surface will become non-uniform due to the formation of coarse compounds.

The content of Si is 0.2% or less. Si is included as a normal impurity, and if it exceeds 0.2%, it will impair the uniformity of the rough surface.
Staining in non-image areas is also likely to occur.

Cu is 0.05% or less. Cu is included as a normal impurity, and if it exceeds 0.05%, the uniformity of the rough surface will be impaired and stains will easily occur in non-image areas.

The alloy used in the present invention contains impurities such as Mn, Cr, and Zn, and their content is 0.05%.
+ if below! 'l'XU no.

Furthermore, it is preferable to add Ti and B to the undeveloped IjI for the purpose of refining the ingot structure. The amount added is Ti0.0
5% or less, 80101% or less is appropriate.

The aluminum alloy plate having the above composition is manufactured as a plate through processes such as casting, hot rolling, cold rolling, intermediate annealing, and temper annealing. There is no particular problem in thermal refining with HIX, H2X, or H3X. This aluminum alloy plate is subjected to surface roughening (graining) treatment by the method described below.

The first mechanical roughening treatment method (sand 11☆ trowel) is to sand the aluminum surface with a metal wire (Wire Brush Grain υ), and sand the aluminum surface with a polishing ball and polishing agent. Sand such as the ball-grain method, the brush-grain method in which the surface is sanded with a nylon brush and ωE abrasive, the honing-grain method in which an abrasive is sprayed at high pressure on the surface, and the fusist-dalein method. Any of the above methods may be used alone or in combination.

Conventionally, prior to mechanical graining, the aluminum surface is generally pretreated to remove rolling oil from the aluminum surface and to expose a clean aluminum surface. For the former, solvents such as trichlene, surfactants, etc. are used. Also,
For the latter, a method using an alkaline etching agent such as sodium hydroxide or potassium hydroxide is widely used.

However, according to the present invention, pretreatment prior to mechanical graining can be omitted, except in cases where a particularly large amount of rolling oil is attached.

The surface of an aluminum plate that has been mechanically grained in this way still contains abrasives, aluminum chips, etc. that have bitten into it during graining, and if electrochemical roughening is subsequently performed, the surface will become rough. The process becomes uneven, and a large amount of undissolved residue is generated on the surface of the aluminum plate.

Therefore, it is necessary to chemically treat the surface of the aluminum plate with an acid or alkali aqueous solution for the purpose of smoothing, equalizing, etc. the electrochemically grained aluminum plate.

Specific examples of the acid or alkaline aqueous solution include acids such as hydrofluoric acid, fluorozirconic acid, phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, and sodium hydroxide, potassium hydroxide, sodium triphosphate, sodium aluminate, and silicic acid. An alkaline aqueous solution such as sodium or sodium carbonate is used. These acid or alkali aqueous solutions can be used alone or in combination of two or more.

Chemical treatments include these acids or alkalis, 05-4
It is common to use a 0% by weight aqueous solution and conduct the treatment for 5 to 300 seconds at a liquid temperature of 40°C to 100°C.

However, when the aluminum surface is chemically treated with an aqueous acid or alkali solution, an insoluble residue, ie, smut, is generated on the surface.

This smut can be removed with phosphoric acid, nitric acid, chromic acid or mixtures thereof.

Is it desirable for the aluminum surface to be electrochemically treated to be a clean surface without smut in Undeveloped II?1 For example, if the municipal solution is acidic and has a desmutting effect, this can be omitted. .

The aluminum plate treated in this way is subsequently subjected to electrochemical roughening. The electrochemical Kleinink method is described in Japanese Patent Publication No. 48-28123 and British Patent No. 896,563.

The electrolytic graining described above is performed using a conventional alternating current with a sinusoidal waveform, but special waveforms (iE sinusoidal wave, rectangular wave, trapezoidal wave) as described in Japanese Patent Application Laid-Open No. 58602 are also used. It may also be done using

Further, as the electrolyte, hydrochloric acid or its salt, nitric acid or its fi!
One type of shade or a mixture of two or more types of shade can be used.

Furthermore, if necessary, compounds such as amines shown in JP-A-47-38301 or JP-A-49-57902 may be used.
Sulfuric acid shown in Japanese Patent Publication No. 51-41653, boric acid shown in Japanese Patent Publication No. 51-41653, West German Published Patent No. 22502
Phosphoric acid, etc. shown in Specification No. 75 II may be added.

It is preferable to form an anodic oxide film on the surface of the aluminum support obtained in this way.As the electrolytic solution, in addition to sulfuric acid, for example, phosphoric acid, chromic acid, formic acid, sulfamic acid, benzenesulfonic acid, etc., or two types thereof can be used. When an electric current is passed in an aqueous or non-aqueous solution combining the above with aluminum as an anode, an anodic oxide film can be formed on the surface of the aluminum support. This anodic oxidation forms a porous oxide film on the aluminum surface, which improves water retention and
The adhesion and abrasion resistance of the photosensitive layer can be improved.

The treatment conditions for anodic oxidation depend on the electrolyte used.
Generally speaking, the C degree of the electrolytic solution is 1 to 80% by weight, the liquid temperature is 5 to 70 degrees Celsius, the current density is 0.5 to 60 amperes/d, and the voltage is 1 to 1 OOv. , an appropriate electrolysis time range of 30 seconds to 50 minutes. More specifically, the anodizing treatment conditions as shown in the table below are preferable.

As described above, the method of the present invention involves sequentially subjecting an aluminum alloy plate containing Mg, Fe, Si, Cu, etc. in a predetermined amount to mechanical roughening, acid or alkali treatment, electrochemical roughening treatment, and anodizing treatment. The Mohan printing original plate produced by the company has sufficient tensile strength and fatigue strength, has an appropriate surface roughness, and has excellent water retention properties.The material's corrosion resistance and water retention properties combine to make it extremely resistant to staining in non-image areas. It is excellent.

Note that the anodized aluminum plate may be further treated by a method such as immersion in an aqueous solution of an alkali metal silicate, such as sodium silicate, as described in the specifications of U.S. Pat. , U.S. Pat. No. 3,860,426, water-soluble metal 11! An undercoat layer of lignophilic cellulose (eg, carboxymethyl cellulose, etc.) containing (eg, zinc acetate, etc.) can also be provided.

A photosensitive layer conventionally known as a photosensitive layer of a PS plate is provided on the support for a lithographic printing plate according to the present invention to obtain a photosensitive printing plate.

The 1i-plate printing plate obtained by plate-making processing has excellent performance.

- The composition of the heat-sensitive layer includes the following.

■Photosensitive layer consisting of a diazo resin and a binder A combination of a diazonium salt and an organic condensing agent containing a reactive carbonyl group such as an aldol or an acetal as disclosed in each of the 11 specifications of U.S. Patent Nos. 2,063,631 and 1,667,415. A synthesis product of the reaction product diphenylamine-p-diazonium salt and formaldehyde (so-called photosensitive diazo resin) is preferably used. Other useful condensed diazo compounds are disclosed in Japanese Patent Publication No. 49-48001 and Japanese Patent Publication No. 49-49.
-45322.

It is disclosed in various publications such as No. 49-45323.

These types of photosensitive diazotized compounds are usually in water bath form.
l! It is obtained in the form of , and can therefore be applied from an aqueous solution. Or these water-soluble diazo compounds
A substantially water-insoluble photosensitive reaction product obtained by reacting with an aromatic or aliphatic compound having one or more phenolic hydroxyl groups, sulfonic acid groups, or both by the method disclosed in Japanese Patent No. 1167 Polymeric diazo resins can also be used. It can also be used as a reaction product with hexafluorophosphate or tetrafluorophosphate as described in JP-A-56-121031. In addition, diazo resins described in British Patent No. 1312925 Specification M are also preferred.

(2) Photosensitive layer consisting of an 0-quinonediazide compound Particularly preferred 0-quinonediazide compounds are O-naphthoquinone cyasito compounds, such as U.S. Pat.
No. 59112, No. 2907665, No. 30461
No. 10, No. 3046111, No. 3046115, No. 3046118, No. 3046119, No. 3046120, No. 3046121, No. 304
No. 6122, No. 3046123, No. 3o6143
ot3, No. 3102809, No. 3106465, No. 3635709, No. 3647443 I
It is written in many F1 line materials including JI specifications, and these can be suitably used.

■Azide compound and binder (photosensitive layer consisting of a polymer compound) For example, British Patent No. 1235281, British Patent No. 149586
In addition to the compositions comprising an acid compound and a water-soluble or alkali-soluble polymer compound described in the specifications of No. 1 and JP-A-51-32331 and JP-A-51-36128, JP-A-Sho 50- No. 5102, No. 50-8430
No. 2, No. 50-84303 ts, No. 53-12984
The present invention includes compositions comprising a polymer containing an agitator and a polymer-compound as a binder as described in each publication of the above-mentioned publication.

(4) Other photosensitive resin layers, for example, polyester compounds disclosed in JP-A-52-966965; British Patent Publication No. 4-112277-
't, Publication No. 1313309, Publication No. 1341004
Publication No. 1,377,747, etc.
Polyvinyl cinnamate resin described in U.S. Patent No. 4
The photopolymerizable photopolymer compositions described in the specifications of No. 07252.8 and No. 4072527 are included. The amount of photosensitive layer provided on the support is approximately 0.1
~7g/rrl, preferably 0.5-4g/rrr'
is within the range of After image exposure on the 23rd plate, a resin image is formed by conventional processing including development. For example, in the case of the 28 plate having the photosensitive layer (1) consisting of a diazo resin and a binder, after image exposure, the photosensitive layer in the unexposed areas is removed by development to obtain a lithographic printing plate. In addition, in the case of the 23 plate having the photosensitive layer (1), after image exposure, the exposed area is removed by developing with an alkaline aqueous solution.
11 tons of plate-printed clothes were sold.

(Example) Hereinafter, a more detailed explanation will be given based on examples.

Example 1 MI aluminum alloy No. 1 to No. 1 shown in Table 2
．． 12 was melted and cast, and both sides were face-milled to a thickness of 350mm.
An ingot with a length of 2000 mm was prepared and soaked at 550°C for 1 hour. This is 450
After hot rolling at a temperature of ~250°C to a thickness of 4.5 mm, the plate was further cold rolled to a thickness of 0.3 mm (area reduction rate of 93.
3%). These are continuously passed through an annealing furnace at 300°
An aluminum alloy plate for lithographic printing was manufactured by subjecting the aluminum alloy plate to thermal annealing for 30 seconds at C.

Next, aluminum alloy rolled plates No. 1 to No. 12 and No. 13 (plate thickness o, 30 mm J I 510
50-H1B aluminum alloy plate), No. 14 (plate thickness 0.30mm JIS l l 00-Hl6 aluminum alloy plate), No. 15 (plate thickness 0.30mm
JIS 3003-H14 aluminum alloy plate) was grained using a rotating nylon brush in a suspension of pumice stone and wood, and then the aluminum was dissolved using a 20% aqueous solution of sodium chloride at a rate of 5 g/m'. I etched it to make it look like this. 25% after washing on ice for 1 minute
A substrate was prepared by pickling with a nitric acid aqueous solution and washing with water. The substrate thus prepared was subjected to alternating current electrolysis at a density of 20 A/drn' in an electrolytic bath containing 111% nitric acid and 20% S, as described in JP-A-54-146234. Subsequently, the surface was cleaned by immersing it in an aqueous solution of 15% sulfuric acid at 50°C for 3 minutes, and then an oxide film of 3 g/m' was removed in an electrolytic solution containing 20% sulfuric acid as a main component at a bath temperature of 30°C. has been established.

The following photosensitive layer was provided on the sample prepared in this manner so that the dry coating amount /Ii was 2.5 g/rn'.

Nisdel compound of oak 1-quinone-1,2-diadiF-5-sulfonyl chloride, pyrogallol, and acetone resin (described in US Pat. No. 3,635,709, l111.!J Examples) 0.751<Cr Solnopolac Resin 2.00g Oil Blue 11601 (Orient Chemical) [1,[
14g ethylene dichloride 16g2
- Methoxyethyl acetate 12g The photosensitive lithographic printing plate thus obtained was brought into close contact with a transparent positive image from a distance of 1 m using PS light [Toshiba Metal Halide Lamp MU2].
After exposure for 30 seconds with a 000-2-OL type 3KV light source, sold by Fuji Photo Film Co., Ltd., the film was immersed in a 5-15% sodium silicate aqueous solution for about 1 minute and developed. Then, wash with water, dry, and prepare samples No. 1 to No. L5.
It was created.

Tests were conducted on the uniformity of the electrolytically etched rough surfaces, stains in non-image areas, fatigue strength, and tensile strength of samples Nos. 1 to 15 prepared in this way, and the results are shown in Table 2.

(Test method) (1) Uniformity of rough etched surface surface condition y,! was observed with a scanning electron microscope, and the uniformity to Pi 1 was rated 1;f, and excellent was marked with O, good was marked with △, and poor was marked with X.

(2) II Image Area Stain Offset Printing Base KOR 1O) After printing the i area, evaluate the stain on the non-image area. Excellent ones are marked O, good ones are marked △, poor ones are marked x expressed.

(3) Fatigue strength Cut a test piece with a width of 20 mm and a length of 100 mm from each sample, fix one end to a jig, and place the other end in the L direction.
The sample was bent at an angle of 0.06 degrees, returned to its original position, and counted as one time to measure the number of times it took to break.

(4) Tensile Strength A JIS No. 5 test piece was taken from each sample and subjected to a tensile test, and the tensile strength, 0.2% proof stress, and elongation rate were kept constant at a.

As is clear from Table 2, the printing aluminum alloy plates No. 1 to No. 7 obtained by the uninvented method V have uniformity of the electrolytically etched rough surface, stain resistance of non-image areas during printing, and fatigue strength. , satisfies all properties in terms of tensile strength,
It can be seen that it is superior to the conventional JIS 1050.1100 and 3003.

On the other hand, aluminum alloy plates No. 8 to No. 12 with comparative alloy compositions outside the composition range of the aluminum alloy plate in the Unhappened 151 method have rough surface uniformity, stains in non-image areas during printing, fatigue strength, It can be seen that one of the properties of tensile strength is inferior. In other words, N, o, with less Mg content,
In No. 8, the uniformity of the rough surface and the staining of the non-image area during printing are good, but the fatigue strength and tensile strength are poor, and No. 9 to No. 11 have a high content of Mg, Si, and Fe. Although the bow 1 tensile strength is good, either the uniformity of the rough surface or the staining of the non-image area during printing is poor. Also, No. 12 with a lot of Cu
is inferior in the uniformity of the rough surface and in the stain resistance of non-image areas during printing.

Example 2 Aluminum alloy plate (H38
Regarding surface refining), after performing 13 kinds of roughening treatments A, B, and C in Table 3, surface cleaning M, chemical treatment, and anodizing treatment were performed in the same manner as in Example 1, followed by photosensitive layer installation, exposure, and development. and KO
A printing test of 150,000 copies was conducted using an RI"II printing press. The results are shown in Table 3. The evaluation criteria for each test result was the same as in Example 1.

As is clear from Table 3, mechanical roughening, chemical treatment,
Treatment A according to the present invention in which electrochemical surface roughening treatment was carried out sequentially
Because a uniformly rough surface with appropriate surface roughness is obtained by electrolytic etching, it has good water retention and no staining occurs in non-image areas even after printing 150,000 copies. On the other hand, in case B, in which no mechanical surface roughening was performed, the uniformity of the electrolytically etched rough surface was somewhat poor and the water retention was insufficient, resulting in staining of non-image areas. C, which was subjected to electrolytic etching without chemical treatment after mechanical roughening, had poor uniformity of the roughened surface and a large amount of undissolved residue remained, making it unsuitable as a printing plate and causing many stains.

(5e, effect of light) As described above, the lithographic printing original plate obtained by the method of the present invention has excellent uniformity of the rough surface, is resistant to staining in non-image areas, and has excellent fatigue strength and tensile strength. This method has the remarkable effect of being able to provide a lithographic printing plate that also has the following characteristics.

Claims (2)

[Claims] (1) Mg0.35-0.9% by weight, Fe0.05-0
．． After mechanically roughening an aluminum alloy material containing 5 wt. 1. A method for producing a lithographic printing original plate, which comprises using a support subjected to electrochemical roughening treatment in a nitric acid-based or nitric acid-based electrolytic solution. (2) The method for producing a lithographic printing original plate according to claim 1, further comprising performing an anodic oxidation treatment after the electrochemical surface roughening treatment.