JPS60215725A - Blank aluminum alloy plate for printing - Google Patents

Abstract

PURPOSE:To provide a blank Al alloy plate for printing having an excellent surface treatability by subjecting the blank Al alloy material which is controlled respectively in the content of Si, Fe, Cu and Ti and is controlled in the content of Si to a specific range according to the content of Cu and Mg to intermediate annealing then to cold rolling. CONSTITUTION:A blank Al alloy material consisting, by weight %, of <=0.25% Si, 0.05-1.0% Fe, <=0.03% Cu, <=0.10% Ti, <=0.03% Mo as an impurity and the balance Al and unavoidable impurities and contg. Si in the range satisfying the formula according to the content of Cu and Mg is prepd. The surface of the casting ingot produced by casting such blank material by an ordinary method, i.e., semicontinuous casting is removed by facing and the ingot is hot rolled at a prescribed temp. The resultant steel plae having an intermediate thickness is subjected to intermediate annealing for <=25hr at 300-500 deg.C followed by final cold rolling at 20-95% reduction ratio in order to obtain necessary mechanical strength. The intended blank Al plate for printing obtd. in the above-mentioned way has uniform ruggedness of the rough surface after the roughening treatment without unevenness and a suitable color tone as well.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum alloy base plate used for an offset printing support or a lithographic printing support (hereinafter referred to as an aluminum alloy base plate for printing).

Conventionally, aluminum alloy base plates for printing have generally been made of JIS standard A1050 with a plate thickness of approximately 0.1 to 0.5 all.
Rolled plates such as P, A1100P, or A3003P were used. These printing plates are usually made by removing the surface of the ingot obtained by half-finning by internal milling.
After homogenization treatment if necessary, the sheet is heated to a predetermined concentration and pre-hot rolled, and then cold rolled at a processing rate of 20 to 95% to obtain an intermediate thickness, or a sheet with a thickness of 12W+m. The following coils are directly cast by continuous binding, cold-rolled to an intermediate thickness without going through the hot rolling process, and then intermediate annealed to the intermediate thickness plate. It is produced by final cold rolling at a working rate of 20-95% to obtain mechanical properties.

When actually using such an aluminum metal-containing base plate for printing, the surface of the base plate is first subjected to a mechanical, chemical, or electrochemical process, or a combination of two or more processes. After the surface is roughened, preferably anodized, a photosensitive agent is applied and exposed, and plate making processing such as development is performed, and then in order to improve the strength of the photosensitive film and improve printing durability. 250-300
Short-time heat treatment at °C (this is called burning treatment)
The ink is then wrapped around the cylindrical plate cylinder of a printing press, the ink is applied to the image area in the presence of dampening water, and after being transferred to a rubber blanket, it is printed on the paper surface.

The printing aluminum alloy base plate used as described above is required to have the following characteristics (A), (B), and (C).

(A) It is possible to uniformly form irregularities through the surface roughening treatment, there is no unevenness after the surface roughening, and an appropriate color tone is exhibited. The ability to roughen the surface uniformly and appropriately in this manner is hereinafter referred to as "surface treatability."

(B) There is little decrease in strength due to burning treatment.

Hereinafter, such performance will be referred to as "burning property".

(C) Ink stains do not occur in non-image areas during printing.

This is hereinafter referred to as "ink stain resistance."

Among these characteristics, if the surface treatment properties of (A) are poor, the color tone after roughening becomes whitish or too black, and in some cases, color unevenness occurs, resulting in a decrease in commercial value. In addition, since the unevenness after roughening has a great effect on printing durability and image clarity, it is fundamentally important for printing plates to have good surface treatment properties and uniform unevenness after roughening. It is a condition. When the surface roughening treatment is carried out by electrolytic etching, it is natural that the condition of the roughened surface changes variously depending on the electrolytic conditions and the type of etching solution, but the phenomenon is caused by the electrochemical interaction between the aluminum surface and the electrolytic solution. Since it is a reaction, it goes without saying that the contribution of the characteristics of the material itself (surface treatment properties) cannot be ignored. However, in conventional printing aluminum alloy base plates, the surface treatment properties for roughening have not been deeply studied, and the reality is that they cannot necessarily be said to have sufficient surface treatment properties.

This invention was made against the background of the above-mentioned circumstances, and out of the above three characteristics, paying particular attention to the surface treatment properties, it is possible to develop an aluminum base plate for printing with excellent surface treatment properties, that is, surface roughening treatment. The object of the present invention is to provide an aluminum alloy base plate for printing which has a uniform rough surface with no unevenness and a suitable color tone.

In order to achieve the above-mentioned objective, the present inventors have conducted extensive experiments and studies on the chemical components of aluminum alloy blanks that affect surface treatment properties. It was discovered that the amount, C1,I! and Mlfl have a strong influence, and this invention was made.

In other words, regarding surface treatment properties, the greater the amount of Si in the material, the more uniformly rough the surface can be obtained through surface roughening treatment, and the range of 3i amount in which this uniformly rough surface can be obtained is based on the amount of CLI in the material.
It is influenced by the difference between the amount and Mg1, that is, (Cu-Ma)I, and the higher the (CIJ-Mg) amount, the lower the 3i.
The present invention was completed based on the discovery that the range in which a good rough surface can be obtained can be expanded even when the amount of the surface is reduced.

Specifically, the aluminum alloy base plate for printing of the present invention is obtained by subjecting an aluminum alloy material to intermediate annealing at 300 to 550°C for 24 hours or less and cold rolling at a processing rate of 20 to 95%. The plate has an alloy composition of Si 0.
25% or less, Fe0005~1.0%, CuO, 03%
Below, 7i 0.10% or less, MOo as an impurity
, 03% or less, the remainder being unavoidable impurities and AI,
and 5it(Si%) is Cutx (Cu 96)
, Mill m (Mg%), following (7) (1)
This is an aluminum alloy base plate for printing with excellent surface treatment properties, which is within a range that satisfies the formula.

(Si%) ≧0.08-4 ((Cu%)-(Ml
1%))...(1) Further, the printing aluminum alloy base plate of the present invention will be explained in detail.

Regarding surface treatment properties, as mentioned above, the more 816 in the material, the more uniform the surface roughness after roughening treatment, and the Sil for that purpose is the difference between the amount of CU-1l and the amount of M9, that is, (CLI- to)I, (Cu-Ma
) The larger the amount of Si, the more even the unevenness can be obtained even if the amount of Si is lower. As a result of detailed experiments including the present invention, it was found that in order to obtain excellent surface treatment properties, Sil in the material (Cu
-Mo) It has been found that it is necessary to satisfy the above formula (1) depending on m. If we show the range of Siq in equation (1) in relation to (Cu-Mg)m, we can see that in the area to the upper right of line AB in Figure 1, and to the lower left of line flAB, the surface is roughened. The unevenness of the roughened surface after treatment becomes irregular, making it impossible to form a uniform roughened surface.

Note that the CtI amount and Mo amount are each 0 as explained later.
Since it is within the range of ~0.03%, (Cu-MIJ
) amount is in the range of -0.03% to 0.03%.

Furthermore, if the Si amount exceeds 2.5%, the color tone after roughening becomes too dark, making it difficult to see the image area when inspecting the image rim after development, so the upper limit of Si is 2.5%. 5%. Therefore, if these conditions are shown together in FIG. 1, the range of the amount of 3 and the amount of (Cu-Mg) will be within the shaded area in FIG.

Furthermore, the reasons for limiting the components other than 3i among the material components of the printing aluminum alloy base plate of the present invention will be explained.

When 0.05% Fe is not swirled, surface treatment properties are poor and mechanical properties are also insufficient. On the other hand, if Fe exceeds 1.0%, the ink stain resistance deteriorates, and the color tone after surface roughening treatment becomes too dark.
Undesirable. Therefore, Fe was set within the range of 0.05 to 1.0%.

Ti is added for the purpose of making the crystal grains of the ingot uniform and fine, but if it exceeds 0.10%, the effect will be saturated and it will only unnecessarily increase costs.
．． It was limited to 10% or less. As a means of adding TI for this purpose, rather than using an Al-T1 master alloy,
The effect is greater when the '-Ti-8 master alloy is used. In this case, B is contained, but it is preferable to suppress the B content to 0.02% or less in order to prevent generation of linear defects due to Ti 82 particles.

Qu is added to improve surface treatment properties, but 0.
If Cu is added in an amount exceeding 0.03%, the ink staining properties will deteriorate, so the upper limit of Cu is set to 0.03%.

Mg, which is an impurity, deteriorates surface treatment properties, but Mg
If it is within 0.03%, it coexists with an appropriate amount of Cu and does not deteriorate surface treatment properties. ＆# If it exceeds 90.03%, surface treatment properties will deteriorate even if it coexists with Cu.1
MO needs to be regulated to 0.03% or less.

Other impurities that are unavoidably contained in trace amounts do not particularly adversely affect surface treatment properties, ink staining properties, and burning properties.

Next, the manufacturing process conditions for the printing aluminum alloy base plate of the present invention will be explained. The process conditions up to the intermediate annealing process do not particularly affect the surface treatability, so a normal method may be adopted.

In other words, in the process up to intermediate annealing, the surface of the semi-continuously cast ingot is removed by internal grinding, then homogenized if necessary, and heated to a predetermined temperature before hot rolling. The process of hot rolling and then cold rolling at a processing rate of 20 to 95%, or directly casting a continuous cast coil with a plate thickness of 12 mm or less and cold rolling it as it is without going through the hot rolling process. Adopt. The bales thus made to have an intermediate thickness are subjected to an intermediate annealing under 24-hour opening at 300 to 550°C, followed by two
Final cold open rolling is performed with a reduction rate of 0 to 95%. In this m
The reason for limiting the annealing conditions is as follows. In other words, if the intermediate annealing rIA degree is less than 300°C, sufficient recrystallization does not occur, so it is unsuitable for intermediate annealing;
In this case, secondary recrystallization occurs and the recrystallized grains become extremely coarse, and further, unevenness and blisters occur due to surface oxidation, making the plate unsuitable for printing. On the other hand, the intermediate annealing time is
If the annealing time exceeds 24 hours, the annealing effect will be saturated and it will only be economically disadvantageous, so the maximum annealing time is set at 24 hours.

The effects of this invention will be clarified with examples below.

Examples Various inventive alloys and comparative alloys shown in sample numbers 1 to 11 in Table 1 were melted and semi-continuously cast to 450+++mx.
1200+++mx35001 Cast on an ugly slab.

After performing internal milling of 7-mm on each side of the slab,
Homogenization treatment at 550°C for 12 hours followed by 500°C
Hot rolling was started at ℃, and the plate thickness was 5-I! It was finished into a hot-rolled sheet of l. Next, after cold rolling to a plate thickness of 1.2IIIll, this was intermediately annealed in a stationary annealing furnace at each moisture level shown in Table 2. The temperature increase rate during this constant annealing is approximately 50℃/
The holding time after reaching the annealing temperature was 2 hours.

Next, a blank plate for offset printing was obtained by cold-gate pressing the coil after intermediate annealing with a plate W0.3 mmt.
It is plotted and shown as an x mark in the figure.

After roughening each blank plate obtained in this example by brushing, it was pre-etched at 50°C for 1 minute in a 10% NaOH aqueous solution, and then at 35°C using a nitric acid-based etching solution. The surface was electrochemically roughened by performing AC electrolysis. Then 15%H2
After the FHtFI treatment in the 804 bath, a m-polar oxide film was formed as a next step, and then a photosensitizer was applied to produce psFi for offset printing. This was subjected to predetermined exposure and development treatment, and then subjected to burning treatment at 280° C. for 7 minutes. Using the original plate thus obtained, a printing test of 100,000 copies was conducted in the presence of dampening water.

Table 2 also shows the investigation results of the surface treatability of these invention alloys and comparative alloys. In addition, the evaluation of surface treatment property is as follows:
It was checked whether the uniformity of the unevenness of the roughened surface after the electrochemical surface roughening treatment was obtained, and the results were classified as 0: good, and ×: poor.

As shown in Table 2, in the case of aluminum alloy base plate for printing within the scope of this invention (sample number 1.23.6.7.9
) clearly has excellent surface treatment properties.

On the other hand, alloy sample numbers 4.5.8 and 10.11 as comparative examples both have poor surface treatment properties because the S1 amount does not satisfy the above formula (1) in relation to the (伽−M(J) amount). There is.

In the above embodiment, intermediate annealing was performed by stationary batch annealing, but a so-called continuous annealing method in which annealing is performed by passing the coil through a heating furnace maintained at a high temperature while unwinding the coil is also possible. Of course, intermediate annealing may also be applied.

As is clear from the above description, the printing aluminum base plate of the present invention has excellent surface treatment properties for roughening treatment, and the surface roughening treatment makes it possible to form irregularities uniformly and evenly. At the same time, it was possible to obtain an appropriate color tone through surface roughening treatment, and when printing with a stamp @ plate using this blank plate, good printed matter could be obtained. Therefore, the aluminum alloy base plate for printing of the present invention is extremely useful as a support for offset printing or a support for lithographic printing.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the condition range of Sil (wt%) in the aluminum alloy material of the present invention in correspondence with the amount of (Cu-M(1)), and Figure 2 is a diagram for each alloy of the examples. 1 is a diagram showing the amount of Si and intermediate annealing temperature plotted on a diagram similar to FIG. 1. Applicant Sky Aluminum Co., Ltd. Fuji Photo Film Co., Ltd. Agent Patent attorney Yutaka 1) Hisashi Take (and one other person) No. Figure 1 Sit (wt%) (Cu-Mg > Amount (wt%) Figure 2 (C-Mg) ((wt%) Procedural amendment spontaneously written) 7. Indication of the incident 1982 Patent Application No. 69821 No. 2. Aluminum alloy blank plate for printing the name of the invention 3. Relationship with the amended case Patent applicant address 4-1 Nihonbashi Muromachi, Chuo-ku, Tokyo Name
Sky Aluminum stock lawsuit (one idiot) 4. Agent address: 3-4-18-6, Mita, Minato-ku, Tokyo Contents of amendment (1) 12. stated on page 7, line 14 of the specification. 5
Correct %1 to ['0.25%]. (2) "2.5%" written from line 15 to line 16 on page 7 of the specification is corrected to "lr O, 25%." (3) Figure 2 in the drawings will be corrected as shown in the attached sheet. Figure 2 (Cu-Mg) amount (wt%)

Claims (1)

[Scope of Claims] In an aluminum alloy base plate for printing obtained by subjecting an aluminum alloy material to intermediate annealing at 300 to 550°C for 24 hours or less and then cold rolling at a processing rate of 20 to 95%, the alloy composition of the material However, StO, 25% or less (weight%, same below), FeO, 05 to 1.0%, CuO, 03
% or less, TiO, 10% or less, M17 as impurity
0.03% or less, the remainder being unavoidable impurities and AI, and the 3i content (Si%) is (Si%) ≧0.08-4 (according to the CuI (Co5) and MQ content' (Mg%)). (Co5)-(M!1
%)) is within a range that satisfies the above.