JPH0687279A - Manufacture of substrate for lithographic printing plate - Google Patents

Abstract

PURPOSE:To constitute a method so that simultaneously with correction of a longitudinal warp, a widthwise warp is corrected and moreover, an influence on a substrate can be minimized without imparting great plastic strain to a material. CONSTITUTION:In a manufacture of a substrate for a lithographic printing plate wherein roughening of the surface of an aluminum plate, oxidation of the anode and treatment making into hydrophilicity are performed, correction of the substrate is performed at a temperature of 110-150 deg.C and under tensile stress of 1-4kg/mm<2> in the middle of the various treatment or after the treatment.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a lithographic printing plate support, and more particularly to a method for producing a photosensitive lithographic printing plate having good flatness.

[0002]

2. Description of the Related Art Generally, an aluminum plate is used as a support for a printing plate, and in recent years, due to automation of offset printing, a planographic printing plate having good flatness has been demanded. Therefore, the aluminum plate is straightened by a roller leveling device after rolling. On the other hand, in order to use such an aluminum plate as a support for a lithographic printing plate, it is necessary to have appropriate adhesiveness to a photosensitive material and water retention. Therefore, the surface of the aluminum plate is roughened so as to have uniform and fine grain. Since this roughening treatment significantly affects the stain performance of the plate material and the printing durability when printing is actually performed after plate making,
After anodic oxidation, hydrophilic treatment is carried out if necessary, and its quality is an important factor in plate material production. A roller leveling device is generally used as a method for correcting the flatness of a lithographic printing plate, and this device is repeatedly bent by repeatedly transporting an aluminum strip by sandwiching it between a number of small-diameter rolls from above and below. This is equipment for plastically deforming the skin of the strip material, reducing and subdividing the internal stress of the entire strip, and flattening and straightening the strip, and various improvements have been made. Kaisho 63-19902
JP-A-63-199023 discloses a roller leveling device for preventing failure of a strip plate surface due to foreign matter, and JP-A-63-199023 discloses that the surface of a work roll is made of urethane rubber or a rubber-like material similar to urethane rubber. A roller leveling device characterized by using a coated one is disclosed. However, these roller bearing devices have conventionally been used to repeatedly bend the support body without applying any tension to repeatedly plastically deform the skin material of the strip material, and it is possible to correct the warp in the longitudinal direction of the support body. It was

[0003]

However, the device proposed in Japanese Patent Laid-Open No. 63-199023 is a very preferable device as a device for correcting the warp in the longitudinal direction, but especially for mechanical roughening. It was difficult to correct the generated warp in the width direction. As a method of compensating for this, a straightening method of grasping both ends of the material and giving 1 to 3% elongation is also generally used mainly in the steel field, but in order to give a large plastic strain to the material, the strain is a There are drawbacks that the surface is roughened and the support coated with the photosensitive layer is adversely affected, and continuous processing is difficult and productivity is poor.

The object of the present invention is to solve the above-mentioned problems, correct the warp in the width direction, and, without giving a large plastic strain to the material, minimize the influence on the support. An object of the present invention is to provide a method for manufacturing a support for use.

[0005]

Means and Actions for Solving the Problems The present inventors have
In order to achieve the above-mentioned object, the present invention has been completed by paying attention to the straightening method and paying attention to the tension of the support before and after the conventional straightening device to obtain a support having good flatness. That is, in the method for producing a support for a lithographic printing plate in which anodization of the surface of an aluminum plate, hydrophilic treatment, etc., a tensile tension is applied immediately before coating the photosensitive layer on the support after the above-mentioned various treatments. A method for producing a support for a lithographic printing plate, which comprises straightening with a roller leveling device.
Alternatively, in the method for producing a support for a lithographic printing plate which roughens the surface of an aluminum plate and performs anodic oxidation, hydrophilic treatment, etc., it is corrected by a roller leveling device by applying tensile tension after mechanical roughening. A method for producing a lithographic printing plate support, which comprises performing chemical etching, electrochemical surface roughening, anodic oxidation and, if necessary, hydrophilic treatment. Alternatively, in the method for producing a support for a lithographic printing plate, which comprises roughening the surface of an aluminum plate and subjecting it to anodization, hydrophilic treatment, etc., at a temperature of 110 ° C. during the various treatments or after the treatments.
~ 250 ° C, tensile stress 1 kg / mm ² ~ 4 kg / mm ²
A method for producing a support for a lithographic printing plate, which comprises straightening with. Can be achieved by

In the present invention, "immediately before the photosensitive layer is coated on the support after the above-mentioned various treatments" means that the support after the various treatments such as surface roughening, anodic oxidation and hydrophilization is exposed. Immediately before applying a layer. In the present invention, the term “after mechanical roughening” means that a warp occurs particularly in the width direction of the support due to the mechanical roughening, so that the correction is necessary. In the present invention, to apply a tensile tension to correct by a roller leveling device,
This means that it is possible to correct the width direction by applying a tensile tension before and after the roller leveling device, and the tensile tension is preferably 100 kg to 2,000 kg although it varies depending on the plate width and the plate thickness. 100
If it is less than Kg, the warp in the width direction is insufficiently corrected, and 2,000
If it is 0 kg or more, the roughening state changes, which is not preferable.
As the roller leveling device, the diameter of the straightening roll is suitably φ10 to φ40 mm, and generally 3 to 10 rolls are used as the straightening roll (JP-A-63-19902).
No. 2, JP-A-63-199023). In the present invention, the straightening by the roller leveling device to which the tensile tension is applied needs to be performed at least after the mechanical surface roughening, and if it is performed immediately before coating, it is possible to secure sufficiently secure flatness. The aluminum support for a lithographic printing plate used in the present invention has a purity of 99.5% or more.
Aluminum materials that can be used for the lithographic printing plate support such as 50 materials and Mn-containing 3003 and 3005 materials can all be targeted.

For use as a lithographic printing plate, the surface of an aluminum plate is usually roughened in order to improve the adhesion to the photosensitive film and to improve the water retention property. Surface roughening, chemical etching, electrochemical surface roughening, etc. are performed, and mechanical surface roughening is often used. In particular, mechanical graining includes a ball grain method, a method of graining with high pressure water, and a method of brush graining. Japanese Patent Laid-Open No. 59-214967 discloses a method for roughening using high-pressure water, and Japanese Patent Publication No. 50-40047 discloses a brush clay method. Further, in the case of ball graining, it is often necessary to have skill such as the material of the ball and the kind of the abrasive. Generally, this mechanical roughening often causes a warp in the width direction. Further, for the mechanical surface roughening, a method of transferring by a rolling roll to perform the surface roughening, for example, JP-A-55-07489,
It goes without saying that the methods disclosed in JP-A-60-203495 are also included. After mechanical surface roughening, it is washed with water and then straightened by a roller leveling device which applies tensile tension to the support. Before and after the roller leveling device, a free loop may be provided to prevent chatter marks and the like due to tension fluctuations. Further, the straightening by the roller leveling device applying the tensile tension of the present invention is provided before the step of applying the photosensitive layer, and as described above, there are many cases where it is provided immediately after the mechanical surface roughening. It may be performed immediately after coating the photosensitive layer after finishing the roughening and anodizing steps.

After mechanical roughening, the aluminum support is subsequently first alkali-etched. Preferred alkaline agents are caustic soda, caustic potash, sodium metasilicate,
Examples thereof include sodium carbonate, sodium aluminate, sodium gluconate, and the like. The concentration is preferably 0.01 to 20%, the temperature is 20 to 90 ° C., and the time is appropriately selected from the range of 5 sec to 5 min, and etching of 1 μm or more is necessary. Subsequently, a substance (smut) that is insoluble in alkali remains on the surface of the alkali-etched aluminum plate, and desmut treatment may be performed if necessary.
The pretreatment is as described above, but subsequently, according to the present invention, AC electrolytic etching is performed in an electrolytic solution containing hydrochloric acid or nitric acid as a main component. The frequency of the alternating electrolysis current is 0.1
-100 Hz, more preferably 0.1-1.0 or 10
-60 Hz. The liquid concentration is 3 to 150 g /
1, more preferably 5 to 50 g / l, and the amount of aluminum dissolved in the bath is preferably 50 g / l or less, and more preferably 2 to 20 g / l. If necessary, additives may be added, but in the case of mass production, it becomes difficult to control the liquid concentration. The current density is 5 to 100 A /
dm ² is suitable, but 10 to 80 A / dm ² is more preferable. The power source waveform is properly selected according to the desired quality and the components of the aluminum support used, but the Japanese Patent Publication Nos. 56-19280 and 55-1919.
It is more preferable to use the special alternating waveform described in each publication of No. 1. Such waveforms and liquid conditions are appropriately selected depending on the quality required along with the quantity of electricity, the components of the aluminum support used, and the like. The electrolytically grained aluminum is then immersed in an alkaline solution as part of the smut treatment to dissolve the smut. As the alkaline agent, there are various kinds such as caustic soda, but it is preferable that the pH is 10 or more and the temperature is 25 to 60 ° C. and the immersion time is 1 to 10 seconds, which is an extremely short time.
Next, it is dipped in a liquid containing mainly sulfuric acid. As the liquid condition of sulfuric acid,
50-400g / l, temperature 25
~ 65 ° C is preferred. Sulfuric acid concentration of 400g / l or more,
Alternatively, when the temperature is set to 65 ° C. or higher, corrosion of the treated layer and the like becomes large, and in the case of an aluminum alloy containing 0.3% or more of manganese, electrochemically roughened grain is broken. In addition, the amount of aluminum base material dissolved is 0.5 g
If the etching amount is equal to or more than / m ² , the printing durability is reduced, so that the amount is preferably 0.5 g / m ² or less.

The anodic oxide coating is 0.1 to 10 g / m ² ,
More preferably, 0.3 to 5 g / m ² is formed on the surface. The treatment conditions for anodization are not generally determined because they vary depending on the electrolytic solution used, but generally the concentration of the electrolytic solution is 1 to 80% by weight, and the liquid temperature is 5 to 70%.
C, current density 0.5 to 60 A / cm ² , voltage 1 to 100
V and an electrolysis time of 1 second to 5 minutes are suitable. The thus-obtained aluminum plate having an anodized film is itself stable and excellent in hydrophilicity, so that a photosensitive coating film can be immediately provided on the aluminum plate, but if necessary, the surface can be further improved. Can be processed. For example, a silicate layer made of the alkali metal silicate described above or an undercoat layer made of a hydrophilic polymer compound can be provided.
The coating amount of the undercoat layer is preferably 5 to 150 mg / m ² . The correction of the present invention is performed after or during such surface treatment. The warp in the width direction, which is the purpose of the correction of the present invention, is
It often occurs from mechanical roughening, and it is desirable to carry out after mechanical roughening. The straightening temperature is 110 ℃
~ 250 ° C, tensile stress 1 kg / mm ² ~ 4 kg / mm ²
Correct with. If the temperature is 100 ° C. or lower, no corrective effect can be expected, and if the temperature is 260 ° C. or higher, the physical properties of the aluminum support itself change due to heat, making it difficult to use as a support for a lithographic printing plate. Also, the tensile stress is 1k
If it is less than g / mm ² , the effect of straightening cannot be expected, and 4 kg /
If it is more than mm ² , the anodic oxide film or the like will be damaged.

Next, a photosensitive coating film is provided on the thus treated aluminum support, imagewise exposed and developed to prepare a plate, which is then set in a printing machine to start printing.

[0011]

【Example】

(Example-1) 0.24 mm thick aluminum plate (JI
S1050) using nylon brush and 400 mesh pumicetone-water suspension, grained the surface, washed well with water, and added to 10% sodium hydroxide aqueous solution at 60 ° C. for 2 times.
It was immersed for 2 seconds and etched. Next, using a 1.2% aqueous nitric acid solution, a sine wave alternating current having a voltage of 12 V was used at 40 ° C., and electrolytic graining was performed under the conditions of an electric quantity of 190 coulomb / dm ² and then 20% sulfuric acid at 60 ° C. Desmut for 2 seconds, wash with water, and then apply 25% sulfuric acid solution to a voltage of 2
Anodization was performed with a direct current of ² V and an electric quantity of 1500 coulomb / dm ² . After that, tensile stress 2 kg / mm ² ,
It is straightened at a temperature of 150 ° C. and used as a sample [A].

(Embodiment 2) A 0.24 mm thick aluminum plate (JIS1050) was used as a nylon brush and 400
Using a mesh pumicetone-water suspension, the surface of which was grained, washed well with water, and immersed in 10% aqueous sodium hydroxide solution at 60 ° C. for 22 seconds for etching. Next, using a 1.2% aqueous nitric acid solution, the voltage was 12 at 40 ° C.
Electricity 190 coulomb / dm using V sine wave AC
After electrolytic graining under conditions of ² , 60% with 25% nitric acid
Desmutted at ℃ for 20 seconds, washed with water, 25% sulfuric acid solution, voltage 22V, electricity 1500 coulomb / dm
^The support anodized with a direct current of ² was applied with a tensile tension of 400 kg and straightened by a roller leveling device. This is designated as sample [B].

(Comparative Example-1) A 0.24 mm thick aluminum plate (JIS1050) was used as a nylon brush and 400
Using a mesh pumicetone-water suspension, the surface of which was grained, washed well with water, and immersed in 10% aqueous sodium hydroxide at 60 ° C. for 22 seconds for etching. Then 1.
After using 2% nitric acid aqueous solution and a sinusoidal alternating current with a voltage of 12 V at 40 ° C., electrolytic graining was performed under the condition of an electric quantity of 190 coulomb / dm ² , and then desmutted with 25% sulfuric acid at 60 ° C. for 20 seconds, After washing with water, anodic oxidation was performed with a 20% sulfuric acid aqueous solution at a voltage of 22 V and a direct current of 1500 coulomb / dm ² of electricity. Then tensile stress 2kg
/ Mm ² , straightened at room temperature and used as sample [C].

[Comparative Example-2] A 0.24 mm thick aluminum plate (JIS1050) was used as a nylon brush and 400
Using a mesh pumicetone-water suspension, the surface of which was grained, washed well with water, and immersed in 10% aqueous sodium hydroxide at 60 ° C. for 22 seconds for etching. Then 1.
After electrolysis graining was performed using a 2% nitric acid aqueous solution and a sine wave alternating current with a voltage of 12 V at 40 ° C. under the conditions of an electric quantity of 190 coulomb / dm ² and then desmutting with 25% sulfuric acid at 60 ° C. for 20 seconds and washing with water. After that, anodization was performed with a 20% sulfuric acid aqueous solution at a voltage of 22 V and a direct current of an electric quantity of 1500 coulomb / dm ² . Then, straightening was performed by a roller leveling device without applying tensile tension to the support. This is designated as sample [D].

(Comparative Example-3) A 0.24 mm thick aluminum plate (JIS1050) was used as a nylon brush and 400
Using a mesh pumicetone-water suspension, the surface of which was grained, washed well with water, and immersed in 10% aqueous sodium hydroxide at 60 ° C. for 22 seconds for etching. Then 1.
After using 2% nitric acid aqueous solution and a sinusoidal alternating current with a voltage of 12 V at 40 ° C., electrolytic graining was performed under the condition of an electric quantity of 190 coulomb / dm ² , and then desmutted with 25% sulfuric acid at 60 ° C. for 20 seconds, After washing with water, anodic oxidation was performed with a 20% sulfuric acid aqueous solution at a voltage of 22 V and a direct current of 1500 coulomb / dm ² of electricity. Tensile stress on the support 8k
It was corrected by applying g / mm ² . This is designated as sample [E].

Substrates [A] and [B] prepared in this way
The following composition was applied to [C], [D] and [E] so that the coating weight after drying was 2.5 g / m ² to form a photosensitive layer. Photosensitive solution composition Ester compound of naphthiquinone-1,2-diazide-5-sulfonyl chloride, pyrogallol, and acetone resin (described in US Pat. No. 3,635,709, Example-1) 0.75 g Cresol novolac resin 2.00 g Oil Bull- # 603 (manufactured by Orient Chemical Co., Ltd.) 0.04 g Ethylene dichloride 16.00 g 2-Methoxyethyl acetate 12.00 g The photosensitive lithographic printing plate thus prepared was placed in a vacuum baking frame to prepare a transparent positive film. From a distance of 1m through 3
After exposing with a metal halide lamp of kW for 50 seconds, it was developed with a 5.26% aqueous solution of sodium silicate (PH = 12.7) having a SiO ₂ / Na ₂ O molar ratio of 1.74, followed by the usual method. Printed according to the procedure. As the printing machine, Sprint 25 (manufactured by Komori Printing Co., Ltd.) was used. Table 1 shows the print evaluation results, the warp (planarity) results in the width direction, and the stain resistance evaluation.

[0017]

[Table 1]

From Table 1, it can be seen that flatness is improved by applying a tensile tension to the support and straightening it by the roller bearing device, but if the tensile tension is too high, the roughening state changes and the stain resistance changes. Has been shown to do.

[0019]

EFFECTS OF THE INVENTION According to the method for producing a lithographic printing plate support of the present invention, the warpage in the width direction generated at the time of roughening, anodizing, and hydrophilizing treatment is corrected, and a roughened state is maintained well,
It has become possible to obtain a lithographic printing plate having excellent flatness.

Claims (3)

[Claims] 1. A method for producing a support for a lithographic printing plate, comprising roughening the surface of an aluminum plate and subjecting it to anodization, hydrophilic treatment, etc., to apply a photosensitive layer to the support after the above-mentioned various treatments. Immediately before the step, a method for producing a support for a lithographic printing plate is characterized in that a tensile tension is applied to correct it by a roller leveling device. 2. A roller leveling device in which a tensile tension is applied after mechanical roughening in a method for producing a support for a lithographic printing plate, which comprises roughening the surface of an aluminum plate and subjecting it to anodization, hydrophilization and the like. Straightening, chemical etching,
A method for producing a support for a lithographic printing plate, which comprises performing electrochemical surface roughening, anodic oxidation and, if necessary, hydrophilic treatment. 3. A method for producing a support for a lithographic printing plate, which comprises roughening the surface of an aluminum plate and subjecting it to anodization, hydrophilic treatment, etc., at a temperature of 110 ° C. to 250 ° C. during or after the various treatments. , Tensile stress 1kg / mm ² ~ 4k
A method for producing a lithographic printing plate support, which comprises straightening at g / mm ² .