JPS5842493A - Manufacture of aluminum alloy plate for offset printing - Google Patents

Abstract

PURPOSE:To obtain an aluminum alloy plate capable of providing even rough surface for offset printing by a method in which an Al alloy ingot containing specific amounts of Fe and Si is subjected to a soaking treatment followed by hot rolling, etc., and then to a cold rolling process of a specific reducing rate, and the Al plate is annealed at low temperature and roughened so as to give it a high fatigue strength and an even rough surface. CONSTITUTION:An aluminum alloy ingot composed of, besides Al, 0.15-0.1% Fe, 0.05-0.30% Si, and usual impurities is subjected to a soaking treatment at 450-600 deg.C for 3hr or more and then to hot rolling followed by cold rolling as needed, and the Al plate is subjected to an intermediate annealing to obtain a thickness of about 5mm. of Al plate. The Al plate is further subjected to a cold rolling of reducing rate of 70% or more into a thickness of about 0.3mm. and lastly annealed at a low temperature of 150-250 deg.C for 1-3hr in a batch furnace, etc., to obtain an objective Al alloy plate. In this case, the low-temperature annealing may be performed at 250-350 deg.C for 6-60sec.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an aluminum alloy for offset printing, and in particular, an aluminum alloy plate for offset printing that has a uniform rough surface obtained by roughening treatment and has high fatigue strength. The present invention relates to a manufacturing method.

Aluminum and aluminum alloys are widely used in offset printing plates because they are lightweight, have excellent workability, are hydrophilic, and have excellent surface treatment. Conventionally, commercially available JISIQ50 (purity 99.5%) is used for printing plates.
Above At), JISIloo(A, /=-0,05 ~
0.20% Cu alloy), JIS3003 (At-0,0
Using a plate with a thickness of 0.1 to 0.8 am such as 5-0.2% Cu-1,o to 1.5% Mn alloy, the plate surface was
The plate surface is roughened by mechanical methods such as polishing or brushing, or chemical methods such as acid or alkali etching or electrolytic etching, and if necessary, anodized to improve printing durability. After applying a photosensitive agent to the plate, plate making processes such as exposure and development are performed to form a printing plate with image areas, which is then wrapped around a rotating cylindrical plate cylinder of a printing press.
Ink is applied to the printed area in the presence of dampening water, transferred to a rubber blanket, and stamped onto the paper surface. Therefore, aluminum and aluminum alloy plates for printing are required to have the following properties.

(1) A uniformly roughened surface can be obtained by roughening treatment in order to uniformly adhere the photosensitive agent, improve adhesion, and facilitate management of dampening water during printing.

(2) Both ends of the printing plate are bent and wrapped so that they are inserted into the grooves of the cylindrical plate cylinder. After ink is applied, the plate cylinder is rotated and pressed against a rubber blanket to transfer the ink, so the bent portion is always Must have excellent fatigue strength to withstand repeated stress.

However, the aluminum alloy plate JISI100, JI
Although S3003 has the necessary fatigue strength as a printing plate, it has the disadvantage that the roughened surface is uneven due to surface roughening treatment. In other words, rough surface conditions that are undesirable for printing plates, such as fine line-like patterns (so-called streaks) occurring along the rolling direction of the plate, uneven bit shapes on the rough surface, and scattered spots with insufficient etching, etc. arise. -ti aluminum plate J
IS1050 uses a hard plate (t-ilB) that is hot rolled or hot rolled followed by cold rolling and intermediate annealing, and then cold rolled with an area reduction of 70% or more. However, although a uniformly roughened surface can be obtained by surface roughening treatment, it has the drawback of poor strength and fatigue resistance.

In view of this, as a result of various studies, the present invention has developed a method for manufacturing an aluminum alloy plate for offset printing that has sufficient fatigue strength as a printing plate and can obtain a uniformly rough surface through surface roughening treatment. , FeO, 15-1.0 superior, s i
o, 05 to 0.30%, the balance A1 and normal impurities, an aluminum alloy ingot is soaked and hot rolled, or after hot rolling, cold rolling and intermediate annealing, to give an area reduction of 7.
It is characterized by applying cold working of 0% or more and then performing low temperature annealing.

In the present invention, the composition of the aluminum alloy ingot is limited as described above for the following reasons.

Fe and St form an intermetallic compound, and this compound and single F
Although e and Si refine the crystal grains and make the structure uniform to improve fatigue strength, even if the Fe content is less than 0.15%, S
Even if the i content is less than 0.05%, the effect is small, and even if the Fe content exceeds 1.0% or the Si content exceeds 0.30%, the roughening treatment will not produce a uniform rough surface. This is because you will no longer be able to obtain it.

Impurities contained in aluminum alloy ingots include:
The purpose of the present invention will not be adversely affected if the impurities are to the extent that they are contained in normally commercially available At ingots.

The purpose of soaking an aluminum alloy ingot with such a composition using a normal method is to dissolve some of the Fa and St into solid solution and to uniformly disperse some of the intermetallic compounds of Fe and St. It is desirable to treat at a temperature of ~600°C for 3 hours or more. Subsequently, this is hot rolled, or after hot rolling, cold rolling and intermediate annealing are performed to give an area reduction ratio of 70.
% or more of cold rolling was added in order to uniformly disperse the intermetallic compounds of Fe and St, improve fatigue strength, and create a more uniform rough surface than during the surface roughening process. In cold rolling of less than 70 qb, a uniform rough surface cannot be obtained by the surface roughening treatment, and the improvement in fatigue strength is insufficient. Finally, this is low-temperature annealed in a batch furnace at a temperature of 150 to 250°C for 1 to 3 hours, or in a continuous annealing furnace at a temperature of 250 to 350°C.
An aluminum alloy plate for printing is produced by low-temperature annealing at a temperature of 5- for 5 to 60 seconds. The reason why low-temperature annealing is performed on an alloy plate that has been cold-rolled with an area reduction of 70% or more is to give the alloy plate appropriate strength and fatigue resistance.The low-temperature annealing conditions in a batch furnace and continuous annealing furnace are The reason why is defined as above is that the predetermined strength and fatigue strength cannot be obtained even if it is less than the lower limit or exceeds the upper limit, respectively.

The aluminum alloy plate for offset printing produced in this way has a uniformly roughened surface equivalent to that of the conventional JIS 1050 hard aluminum plate by roughening treatment, and has far superior fatigue strength.

Examples of the present invention will be described below.

Example (1) An aluminum alloy ingot having the composition shown in Table 1 was solidified to have a thickness of 350 m, a width of 1000 fins, and a length of 200 W5, which was soaked at a temperature of 550°C for 10 hours, and then heated. It was made into a thickness of 5 fins by inter-rolling. Next, this was cold rolled to a thickness of 0.3 m+, and finally it was low-temperature annealed at a temperature of 200° C. for 2 hours in a batch furnace to produce an aluminum 6-alloy plate (H2S) for printing. About these alloy plates 3
A 0° double bending fatigue test, a tensile test, and a roughening treatment for use as a printing plate were conducted. The results are shown in Table 1.
Cut out a test piece with a length of 100 mm, fix one end with a jig, bend it downward to an angle of 30 degrees from the base, and then return it to the original position.One round trip is considered as one rupture. The number of times until In addition, the surface roughening treatment was performed after degreasing by commercially available washing, and then in a 2% hydrochloric acid solution at 70°C at a current density of 2.
AC electrolytic etching was performed at OA/m'' for 1 minute. The etched surface was observed, and those with a uniform etching surface were marked with a circle, those with non-uniformity were marked with an x, and those in between were marked with a triangle.

For comparison, JI, a conventional aluminum plate for printing,
Regarding S1050, the ingot was soaked for 10 hours at a temperature of 550°C after the face side according to the conventional method, then hot rolled to a plate thickness of 4 mm, and then cold rolled to a plate thickness of 1.2 mm.
After processing to +llIn, intermediate annealing was performed at a temperature of 360° C. for 1 hour, and this was finished by cold rolling to a plate thickness of 0.3 mm (area reduction rate of 75%). This hard aluminum (Hl
8) was subjected to a 30° repeated bending fatigue test, a tensile test, and a surface roughening treatment. The results are included in Table 1.
I did it myself.

Table 1 As is clear from Table 1, the aluminum alloy plates for printing manufactured by the methods Kan 1 to Na 4 of the present invention meet the conventional JIS 1 standards.
It can be seen that it has the same rough surface uniformity as 050, and has far superior 3o0 bending fatigue strength.

On the other hand, it can be seen that in Comparative Methods Nos. 5 to 8, in which the vJ composition differs from that of the method of the present invention, even though the manufacturing process is the same, the uniformity of the rough surface or the 30° bending fatigue strength is lower. In other words, the uniformity of the rough surface is poor in the li'e-containing bond-comparative method +415 and the comparative method N17 with a large Si content, and the comparative method NIIL6 with a small amount of Fe-containing grains and the comparative method NIL 8 with a small Si content have a poor uniformity of the rough surface. ) 0 The bending fatigue strength is decreased. Example (2) Using an aluminum alloy ingot consisting of Fed, 60%, Si 0.25%, balance At and normal impurities, Example (1
) After soaking treatment in the same manner as above, one part was processed to a thickness of 30 mm by hot rolling, and the other part to a thickness of 6.0 mm, and then cold rolled to a thickness of 0.3 mm each. This was then low-temperature annealed at various temperatures in a batch furnace to produce printing aluminum alloy plates (Table 2 Nal 2 to Nal 5, [17
, +1u18).

In addition, ingots of the same composition were processed in the same manner by soaking and hot rolling to a plate thickness of 6.0 wn, followed by cold rolling to plate thicknesses of 1.0■, 1.5+a, and 0.75m. Then, this was intermediately annealed at a temperature of 360°C for 1 hour, and then cooled.
It was processed to a plate thickness of 0.31M by rolling for 9 minutes, and then low-temperature annealing was carried out at a temperature of 200°C for 2 hours in a batch furnace to produce an aluminum alloy plate for printing (a ¥ 2 Table N [Llo, Na
1l, mallet 16).

Examples (1) of these aluminum alloy plates for printing
30° repeated bending fatigue test, tensile test, and surface roughening treatment were conducted in the same manner as in ). I am happy with the results and manufacturing conditions.
Shown in the table.

−10= As is clear from Table 2, the method of the present invention N[110~N
[It can be seen that all of the printing aluminum alloy plates manufactured using Li2 have excellent 30° bending fatigue strength and good uniformity of the rough surface.

On the other hand, the comparative method No. 6, which has a lower area reduction in cold rolling, has poor uniformity of the rough surface (and the comparative method N, which has a low temperature annealing temperature of less than 150°C in a batch furnace)
It can be seen that the 30° bending fatigue strength of both a17 and those manufactured by comparative method section 18 in which the low-temperature annealing temperature exceeds 250°C is reduced.

Example (3) A plate having a thickness of 13 cm cold-rolled by the method 1@12 of the present invention of Example (2) was annealed at a low temperature through a continuous annealing furnace to produce an aluminum alloy plate for printing. This was subjected to a 30° repeated bending fatigue test, a tensile test, and a surface roughening treatment in the same manner as in Example α). The results and annealing conditions are shown in Table 3.

Table 3 As is clear from Table 3, the aluminum alloy plate for printing manufactured by the method of the present invention has excellent 30° bending fatigue strength, whereas the continuous annealing temperature of the comparative method Na22.350°C is lower than 250°C. It can be seen that the fatigue strength is lower in all cases in the higher comparison method (23).
It is possible to produce aluminum alloy plates for printing that have roughening characteristics equivalent to those of 050 hard plates, but have far superior fatigue strength, and can be used in offset printing plates with remarkable effects. It is something to play.

Claims (1)

[Claims] α) Fe0.15-1.0%, S i O, 05-0,
An aluminum alloy ingot consisting of 30% At and the balance At and normal impurities is soaked and hot rolled, or after hot rolling, cold rolling and intermediate annealing, followed by cold rolling with an area reduction of 70% or more. In addition, a method for producing an aluminum alloy plate for offset printing, which is characterized by subsequently performing low-temperature annealing. Method for producing aluminum alloy plate for printing. (3) The method for producing an aluminum alloy plate for offset printing according to claim 1, which comprises low-temperature annealing at a temperature of 250 to 350°C for 5 to 60 seconds.