JPS6223794A - Substrate of aluminum alloy for offset printing - Google Patents

Abstract

PURPOSE:To improve the strength, gripper-cut resistance and burning resistance of a substrate and thereby to enable to increase of usefulness thereof, by making the substrate contain Si, Mg and Zr in prescribed quantities and, in addition, by selecting the contents of these Mg and Si and those of Fe and Mn as impurities on the basis of a prescribed numerical formula. CONSTITUTION:Si 0.05-0.7wt%, Mg 0.3-1.5wt% and Zr 0.01-0.25wt% are made to be contained, with ranges of the Si content of 0.15wt% and less and the Mg content of 0.5wt% and less excluded, and the contents of these Mg and Si and those of Fe and Mn as inevitable impurities are made to satisfy the following relational expression: Mg>=1.73XSi-0.6X(Fe+Mn). The strength and gripper-cut resistance of a substrate are secured by making it contain Si 0.05-0.7wt% and Mg 0.3-1.5wt%, and the burning resistance thereof is improved sharply by making it contain Zr 0.01wt%, while the occurrence of stain in printing due to the lowering of corrosion resistance of a non-image portion can be prevented by meeting the aforesaid relational expression.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to the creation of an aluminum alloy support for offset printing, which provides strength, burning resistance, and grip resistance while maintaining appropriate surface treatment properties and printability. The present invention aims to provide an aluminum alloy support for offset printing that has excellent cutting properties.

Industrial applications: Aluminum alloy support for offset/groove printing with excellent strength, burn resistance, and sharpness.

BACKGROUND OF THE INVENTION Aluminum alloy supports for offset printing are known in the art. In other words, aluminum and aluminum alloys are generally lightweight, have excellent workability, and have good surface treatment properties, so they are suitable for offset printing supports, and are particularly suitable for JIS
1050 (AJ with purity of 99.5% or more), JISI
loo (A/RI with purity of 99.0% or more, JIS30
03 (AN-0.05-0.2% Cu-1,0-1.
Aluminum or aluminum alloys (hereinafter simply referred to as aluminum alloys) such as 5Mn alloy) are widely used.

After these aluminum alloys are made into plates, the surface is roughened by a process of mechanical, chemical, or electrochemical methods, or a combination of two or more, and then anodized. A photosensitive composition (generally a photosensitive resin) is coated on the plate surface and dried to form a so-called PS plate. Next, this PS plate is subjected to plate-making processes such as image exposure, development, water washing, and gumming to produce a printing original plate, but this image exposure creates a gap between the exposed and unexposed areas of the photosensitive resin layer during subsequent development. A difference occurs in solubility in a developer during processing, and either the exposed portion or the unexposed portion is dissolved in the developer or removed by the development treatment,
The other remains on the aluminum plate serving as the support and forms an image. The image area exhibits ink receptivity, and the non-image area where the photosensitive resin is dissolved and removed as described above exhibits water receptivity due to the exposed surface of the hydrophilic aluminum support.

Next, both ends of the printing original plate are bent to form a gripping part for the printing press, and fixed to the cylindrical plate cylinder of the printing press, and dampening water (water or aqueous liquid) is supplied to the plate surface. A process of retaining a film of the dampening solution on the non-image area, supplying and adhering ink to the image area, and transferring the ink adhered to the image area to the blanket cylinder and then to the paper surface etc. Printing is performed by repeating the steps. In general, it is possible to obtain as many as 100,000 good prints by appropriately selecting the photosensitive composition coated on the support, and it is possible to obtain many more prints. In response to the demand for (improvement of rigidity), in the plate-making process, the PS plate is exposed and developed in the usual manner, and then heat-treated at high temperature (referred to as burning treatment, usually at 200-280°C for 3-7 The image area is strengthened by heating (heating for about a minute).

However, with advances in printing technology in recent years, printing speeds have increased and the stress applied to the printing plate, which is mechanically fixed to both ends of the printing press cylinder, has increased, resulting in increased strength requirements for the support. If the support strength is insufficient, the fixed part may be deformed or damaged, causing problems such as printing misalignment. It is essential to improve heat resistance. That is, as mentioned above, the bending grip part of the printing plate fixed to the plate cylinder receives repeated stress due to contact with the blanket cylinder, resulting in a fatigue fracture phenomenon (referred to as grip breakage), and in the burning process, the bending grip part is subjected to repeated stress due to contact with the blanket cylinder. It is necessary to withstand high temperatures, and if either of these is insufficient, the durability will inevitably be lacking.

Therefore, considering such a relationship, the present applicant has proposed a technique as disclosed in Japanese Patent Laid-Open No. 59-153861. In other words, this technology uses zirconium at a rate of 0.
This is an aluminum alloy support containing 02 to 0.20 wt%.

Apart from this, in British Patent No. 1421710, magnesium 0.4-1.2 wt%, silicon 0.5-1.5 wt% and manganese 0.0 O5-
An aluminum alloy support containing 0.4 wt% and iron:O,OS to 0.5 wt% has been proposed, and is said to be preferable for improving support strength and grip resistance.

Problems to be Solved by the Invention However, the above-mentioned conventional devices cannot adequately meet the above-mentioned demands. In other words, those based on JIS 1050 achieve uniform roughness and appropriate surface roughness through electrochemical roughening treatment, and stains are less likely to occur in non-image areas during printing, but the support strength is slightly insufficient and the burn resistance is poor. Poor grip and cut resistance. In addition, those based on JIS 3003 have suitable support strength, burning resistance, and gripping resistance, but they cannot obtain uniform roughness or appropriate surface roughness due to electrochemical roughening treatment, and furthermore, during printing, Staining of non-image areas is also likely to occur.

Japanese Patent Application Laid-Open No. 59-153 to address these problems
Although the product according to Publication No. 861 has excellent surface treatment properties and printability, and has improved burning resistance,
The strength level of the support still meets the JIS 1 standard.
It was confirmed that the level was equivalent to 050.

Furthermore, although the material according to British Patent No. 1,421,710 has improved support strength and grip resistance, it is insufficient in terms of printability, specifically, staining of non-image areas during printing. However, this staining of non-image areas is a phenomenon in which ink adheres to the non-image areas of the printing plate that is in contact with dampening water during printing and is transferred to the printed matter, which is a major disadvantage for offset printing purposes. I have no choice but to do so.

In other words, it is important for an aluminum alloy support for offset printing to maintain a high level of balance in all of the above-mentioned properties. Even if it has these characteristics, if it is inferior in some areas, the industrial value of this kind of support that can obtain clear printing and increase its durability will be limited by its inferior characteristics, and the overall In other words, problems still remain.

In particular, it is important to improve the water retention and corrosion resistance of non-image areas in order to prevent them from becoming smeared during printing. It is necessary to obtain a more uniform rough surface and a healthier anodic oxide film than before.

Means for solving the structural problems of the invention Si: 0.05 to 0.7 wt%, Mg: 0.3 to 1
．． 5 wt% Zr: 0.01 to 0.25 wt%, except for the range where the Si content is 0.15 wt% or less and the Mg content is 0.5 wt% or less, and these Mg, St and F as an inevitable impurity
An aluminum alloy support for offset printing, characterized in that the contents of e and Mn satisfy the relationship of the following formula, and the remainder consists of Aβ and inevitable impurities.

Mg≧1.73×Si −0.6X (Fe +Mn
) Action Si: 0.05-0.7wt%, Mg: 0.3-1.5
By including this content in wt%, the strength of the support and the gripping property are ensured, and a uniform grain is obtained in the electrochemical surface roughening treatment. Further, by excluding cases where St is 0.15 wt% or less and Mg is 0.5 wt% or less, the required strength as a printing plate is ensured.

By containing 0.01 wt% of Zr, coarse precipitation due to MgzSi is prevented when the rolled material is heat treated,
It not only ensures uniformity and printability in surface roughening treatment, but also greatly improves burning resistance.
By setting the upper limit to 25 wt%, non-uniformity of the crystal structure during hot rolling is avoided, and crystal grain streaks are not generated.

The Mg% Si and F as unavoidable impurities
Regarding the content of e% Mn, Mg≧1.73×Si −0.6X (Fe +Mn
) By satisfying the relational expression of This substantially prevents the presence of such particles, ensures a predetermined level of surface roughening, and prevents staining during printing due to deterioration of corrosion resistance in non-image areas.

EXAMPLE To explain the details of the present invention in more detail, first, the composition of the components contained in the alloy support of the present invention is as follows.

That is, Si: 0.05-0.7 t%, Mg: 0.3-1
．． 5 wt% is contained in solid solution state or Mg
This is to develop the support strength and grip-cut resistance required for the zSi phase, and if Si is less than 0.05 wt% and Mg is less than 0.3 wt%, it is difficult to obtain the predetermined strength level and grip-cut resistance. This may result in problems with the plate running out when mounting the plate as a printing plate or during printing. Furthermore, if the Si content exceeds 0.7 wt% and Mg content exceeds 5-1%, the strength will be increased, but uniform grains will not be obtained during electrochemical roughening treatment, which is not preferable. Also, both Si and Mg have St of 0.15w.
If the Mg content is less than t% or less than 0.5wt%, the required strength as a printing plate cannot be obtained.

Furthermore, Si and Mg were determined experimentally, Mg i! ≧1
．． 73X (Amount of Si) 0.6 (Amount of Fe + Mn)
This method substantially prevents Si present in an amount exceeding the amount necessary to form the Fe-Mn)Si phase from existing as elemental Si in the matrix or in the anodic oxide film, and ensures a predetermined level of surface roughness. This is to prevent stains during printing due to decreased corrosion resistance in non-image areas.

Zr is used to prevent coarse precipitation of Mg and Si when the rolled material is heat treated, to ensure uniformity and printability in surface roughening treatment, and to significantly improve burning resistance. If it is less than 0.25 wt%, such an improvement effect is insufficient, while if it exceeds 0.25 wt%, the crystal structure becomes non-uniform during hot rolling, resulting in crystal grain streaks, even though it has the above-mentioned improvement effect, so it is preferable. It is more preferably 0.01 to 0.15 ivt%.

Fe and Mn as unavoidable impurities in the alloy support according to the present invention have the effect of refining the crystals of the alloy and preventing recrystallization from coarsening, but if either one exceeds 0.40 wt%, they are formed during casting. Since intermetallic compounds containing Fe and Mn become coarse and deteriorate printing performance, it is desirable that the content of each of them be 0.4 wt% or less, and the total amount of the intermetallic compounds be 0.5 wt% or less. Further, it is preferable that Cu%Zn as an impurity be 0.05tmt% or less, and in particular, when the required quality is high for the stain resistance of non-image areas during printing, the Cu content may be in the range of 0.004 to 0.020wt%. It is necessary to.

Furthermore, Ti and B used as crystal refining agents in the manufacture of slabs include Ti of 0.05 wt% or less and B of 0.0 wt%.
It is desirable that the content be 1 wt% or less.

To explain the plate-making and plate-making process of the aluminum alloy support for offset printing of the present invention having the above composition, after face-cutting a cast slab obtained from a molten alloy having the above composition, it is heated at a normal temperature of 460 to 600°C. Perform homogenization treatment by holding for 2 hours or more. Next, solution treatment is performed to perform hot rolling and cold rolling steps. Specifically, for example, it is heated to a temperature of 400 to 600°C in a continuous annealing furnace, and after reaching this predetermined temperature, it is heated at a temperature of 30°C/min or more.
Air cooling is performed at a cooling rate of 100° C. or less, preferably rapid cooling is performed by water cooling. Subsequently, the plate is cold rolled at a processing rate of 10% or more, preferably 20% or more, to a thickness of 0.1 to 0.5 mm. If desired, before the final cold rolling, it may be subjected to a tempering treatment in which it is heated and held at 140°C or less for 1 hour or less in a batch type or continuous annealing furnace, and then cold rolled at a working degree that provides a predetermined strength. can. Furthermore, if necessary, after the final cold rolling, a batch type or continuous annealing furnace may be used to
~Aji that exists! -Fe system or A I -Fe
It is desired that compounds such as (Mn)-3i-based compounds be finely dispersed, and that Mg and Si in processed Mi fibers be treated in a solid solution state or as a MgzSi phase to be uniformly and finely precipitated. A predetermined support strength and grip resistance can be obtained, the uniformity of the grain in the surface roughening treatment can be further ensured, and staining of non-image areas during printing can be appropriately prevented.

The aluminum alloy plate produced in this manner is subjected to processing as a PS plate and plate-making processing before being used for actual printing work. That is, first, the surface is roughened by mechanical graining or electrochemical graining, and then chemically etched with acid or alkali and desmutted by pickling. Further, if necessary, an oxide film formation treatment is performed by anodizing treatment or chemical conversion treatment, and an undercoat layer formation treatment of an alkali metal silicate, hydrophilic cellulose, or the like is performed thereon. Subsequently, a suitable photosensitive composition is applied, dried, and then cut into a desired size to obtain a PS plate. This PS plate is exposed to light with a desired image, and plate-making processes such as development, washing, burning, and gumming are performed.

The plate-made printing original plate is further bent at both ends to form gripping portions for the printing press, and then fixed to the cylindrical plate cylinder of the printing press and used for printing operations.

In this printing work, the handling of the plate is good (there is little deformation when the plate is installed, and even if it is subjected to repeated stress at the bending grip part, each plate does not stick, and the cutting ability is stable at a high level. For example, Stably obtains excellent stiffness resistance of 200,000 sheets or more.

A specific manufacturing example of the product according to the present invention will be described below.

Production Example 1 Nine types of aluminum alloys (A
~■) was melted and filtered using a microporous filter, a slab with a thickness of 56 on was obtained by DC casting, and the alloy A
-H was homogenized at 560°C for 4 hours, then hot rolled to a thickness of 6 mm, then cold rolled to 0.
．． The plate was made into a 6 m thick plate, and then magnetic induction heating (Trans
uerse FluxInduction Heati
ng ) at a temperature increase of 150°C/sec to 550°C x 5
In both cases of holding at 180° C. and 500° C./sec, a batch annealing furnace was used to perform tempering treatment at 180° C. x 30 ml to produce the desired aluminum alloy plate for offset printing.

For alloy (■), it was homogenized at 560°C for 4 hours, then hot rolled (6 mm thick) and cold rolled.
．． A plate with a thickness of 5.5 mm was then subjected to intermediate annealing at 400° C. for 1 hour, and then finally cold rolled to a plate with a thickness of 0.31 mm. In addition, commercially available conventional materials JISL050-I (18) and JIS-3003-H2S 0.3 tm thick plates were used as test materials.

The 0.2% yield strength of each aluminum plate obtained as described above was measured by a conventional method, and as an index of heat resistance, the aluminum plate was immersed in a salt bath kept at 270°C for 7 minutes and then subjected to a tensile test. 0,
2% yield strength was measured.

In addition, pre-bending fatigue strength was used as an evaluation index of grip resistance.A test piece with a width of 32 m and a length of 60 m was cut from an aluminum plate, and a 90" After pre-bending to an angle of
One end was fixed with a jig, a constant amplitude was applied to the other end, and the number of times it took for the bent portion to break was measured.

On the other hand, the above-mentioned 11 types of alloy plates were treated as printing supports, and the roughness and the soundness of the anodic oxide film were evaluated. That is, these aluminum alloy plates were grained with a rotating nylon brush in a suspension of pumice stone and water, etched with a 20 wt% aqueous solution of caustic soda, then washed with water, and pickled with a 25-t% aqueous nitric acid solution. After washing with water again, AC electrolysis was carried out at a current density of 20 A/dm or more in an electrolytic bath containing 0.5 to 2.5 wt% nitric acid, and then immersion in a 50°C aqueous solution of 15 wt% sulfuric acid for 3 minutes. After cleaning the surface, it was anodized in an electrolytic solution containing 20-t% sulfuric acid at a bath temperature of 30°C. SEM observation of the surface was carried out to evaluate the uniformity of the grain, and the base aluminum was dissolved in a bromine-methanol solution, only the oxide film was taken out and TEM observation was carried out, and the second layer remaining in the film was Phase particles were evaluated.

The results of these measurements and observations are shown in Table 2 below. Note that all measurements of mechanical properties were performed in a direction parallel to the rolling direction (L direction).

That is, alloy A-E, which is the material of the present invention, has a support strength (0.2%
It is equivalent to or better than comparative materials and conventional materials with high levels of yield strength), burning resistance (0.2% yield strength after heating), and gripping resistance (pre-bending fatigue strength). The level is improving. Furthermore, the surface roughening properties and anodic oxidation film properties were as good as JIS 1050-H18.

Although comparative materials F, G, and H have good mechanical properties, many insoluble second phase particles of 0.1μ or more were observed in the anodic oxide film of F and G, and EDX analysis revealed that these particles did not contain Si. element detected. Comparative material H is Zr.
is below the specified value, so the 0.2% yield strength after heating at 270°C x 7 min is inferior, and comparative material I meets JIS105.
Even though it has the same roughening properties and the soundness of the anodic oxide film as 0-HI3, the support strength is significantly inferior. Conventional materials JIS1050-H2O and JIS3003
'-H16 has support strength, burning resistance, roughening property,
The health of the anodic oxide film remains at a low level.

Production Example 2 The invention material B obtained in Production Example 1 and comparative tanks G and H were continuously subjected to solution treatment under the same conditions as Production Example 1 using 0.6 mm thick cold rolled plates before solution treatment. After quenching and water quenching, and then left at room temperature for about one day, only the final cold rolling as shown in Table 3 below was performed, either before or after this final cold rolling. By combining both tempering conditions, an alloy plate with a thickness of 0.3 m was obtained.

The obtained seven types of alloy plates and conventional materials JIS1050
-H2O (0.3m thick) and JIS3003H16 (0.3m thick)
3m thick) is further processed as a printing plate,
It was evaluated as a printing board.

That is, the following photosensitive layer was applied to a support prepared in the same manner as described in Production Example 1 in a dry coating amount of 2.5 g/
It was formed into a CD.

0.758 compound of naphthoquinone-1,2-diazido-5-sulfonyl chloride and pyrogallol acetone resin (
(Described in the Examples of US Pat. No. 365,709) Talesol Novolank resin 2.00g Oil Blue #603 (manufactured by Orient Chemical Co., Ltd.) 0.04g Ethylene dichloride 16g 2-methoxyethyl acetate 12g Obtained photosensitivity Place the lithographic printing plate in close contact with the transparent positive image and use the PS light (Toshiba metal halide lamp MU2000-2-OL type, 3) from a distance of 1 m.
After exposure for 30 seconds using a 5 int % sodium silicate aqueous solution (having a KW light source), the plate was developed by being immersed in a 5 int% sodium silicate aqueous solution for about 1 minute, washed with water and dried to obtain a printing original plate.

These printing original plates were subjected to the same test as in Production Example 1, and were also installed in an offset printing machine KOH to observe stains in non-image areas. The results are shown in Table 3 below.

In other words, as is clear from Table 3, the material of the present invention has a higher support strength than the conventional material by being cold rolled after solution treatment, or by being tempered before and after the final cold rolling. can be freely changed, and excellent performance comparable to JIS 1050-HI3 can be obtained in terms of surface roughening properties and printability.

"Effects of the Invention" As explained above, when using the 7-element miniram alloy support for offset printing of the present invention, it has the same or better surface roughening properties and printing characteristics than conventional materials, and also has support strength and Due to its excellent resistance to gripping and cutting, problems caused by deformation when the plate is installed and the plate not cutting during printing can be appropriately resolved, and burn resistance has been sufficiently improved to provide highly durable products. This is an invention that has great industrial effects.

Claims (1)

[Claims] Si: 0.05 to 0.7 wt%, Mg: 0.3 to 1.5
wt% Zr: 0.01 to 0.25 wt%, except for the range where the Si content is 0.15 wt% or less and the Mg content is 0.5 wt% or less, and these Mg
An aluminum alloy support for offset printing, characterized in that the contents of , Si, and Fe and Mn as unavoidable impurities satisfy the relationship expressed by the following formula, and the remainder consists of Al and unavoidable impurities. Mg≧1.73×Si−0.6×(Fe+Mn)