JPS60215727A - Blank aluminum alloy plate for printing - Google Patents

Abstract

PURPOSE:To provide a blank Al alloy plate for printing having an excellent resistance to ink staining by subjecting a blank Al alloy controlled respectively in the contents of Si, Fe, Cu, Ti and Mg as an impurity to cold rolling at a specific reduction ratio after intermediate annealing. CONSTITUTION:A blank Al alloy material contg., by weight %, <=0.08% Si, 0.05-1.0% Fe, <=0.03% Cu, <=0.10% Ti and 0.3% Mg as an impurity and consisting of the balance Al and unavoidable impurities is prepd. Such blank Al alloy material is subjected to intermediate annealing by an ordinary method and is then heated to a prescribed temp. and hot rolled, by which a material having an intermediate thickness is obtd. The plate is then subjected to intermediate annealing for <=24hr at 300-550 deg.C followed by final cold rolling at 20-95% reduction ratio to obtain necessary mechanical strength. The resultant blank Al alloy plate for printing has excellent resistance to ink staining and is capable of preventing effectively staining of printed matter owing to sticking of ink to the non-image part during printing.

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 A1050P1 with a plate thickness of approximately 0.1 to 0.5 mm.
A rolled plate such as A1100P or A3003P was used. These printing blanks are usually produced by removing the surface of the ingot obtained by semi-continuous casting with a solidifying agent, applying homogenization treatment if necessary, and then heating it to a predetermined temperature to heat it. Rolled and then cold-rolled at a processing rate of 20 to 95% to obtain an intermediate thickness, or directly cast a coil with a thickness of 12mm or less by continuous casting without going through the hot rolling process. After cold rolling to an intermediate thickness, intermediate annealing is performed on the intermediate thickness plate, and final cold rolling is performed at a working rate of 20 to 95% to obtain the required mechanical properties. It is manufactured by

In order to actually use such a printing aluminum alloy base plate for printing, the surface of the base plate is first processed by a mechanical method, a chemical method, an electrochemical method, or a combination of two or more methods. After the surface is roughened, it is preferably subjected to anodization treatment, then coated with a photosensitizer, exposed to light, and subjected to plate-making processes such as development. ~300
℃1 short time heat treatment (this is called burning treatment)
The ink is applied to the 111th part of the image in the presence of dampening water by wrapping it around a cylindrical plate cylinder of a printing press, and printing on the paper after transfer to a rubber blanket.

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

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

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

(B) 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 uniformly and appropriately roughen the surface as described above is hereinafter referred to as "surface treatment property J".

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

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

Among these characteristics, regarding the ink staining property (A), printing plates must basically avoid ink from adhering to non-image areas during printing and staining the printed matter. However, in the past, ink stains had not been sufficiently investigated from the perspective of the material used for printing aluminum alloy base plates, and as a result, fundamental solutions to ink stains had not been found. I scold you.

According to the research conducted by the present inventors, it has been found that the main cause of ink stains during printing is localized corrosion that occurs when the printing plate reacts with dampening water. It is thought that the problem of dirt can be solved.

The present invention has been made against the background of the above-mentioned circumstances, and provides an aluminum alloy base plate for printing, which can prevent as much as possible the occurrence of ink stains due to ink adhesion to non-image areas during printing, that is, ink The object of the present invention is to provide an aluminum alloy base plate for printing with excellent stain resistance.

In order to achieve the above-mentioned purpose, the present inventors conducted extensive experiments and studies on the chemical components of aluminum alloy base plates that affect ink stain resistance, and found that the amount of S1 has a strong effect on ink stain resistance. (I discovered this effect and came up with this invention.

In other words, the smaller the amount of Si in the material, the more difficult it is for ink to adhere to non-image areas during printing, and in particular, if the amount of S1 is 0.08%, the frequency of ink stains can be reduced to a level that does not pose a practical problem. After discovering this, he completed this invention.
Specifically, the aluminum alloy base plate for printing of the present invention is produced by intermediate annealing of an aluminum alloy material at 300 to 550°C for 24 hours or less, followed by cold rolling at a processing rate of 20 to 95%. A plate with an alloy composition of SiO,0
8% or less, Fe0.05-1.0%, CuO, 03%
Hereinafter, 1'-to, io% or less, MgO as an impurity
,03% or less, the remainder unavoidable impurities and 8! This is an aluminum alloy base plate for printing with excellent ink stain resistance.

Further, the printing aluminum alloy base plate of the present invention will be explained in detail.

As for ink staining, as described above, the smaller the amount of Si in the material, the less ink staining in non-image areas. According to detailed experiments conducted by the present inventors, it has been found that in order to obtain good ink stain resistance, the amount of 3i in the material needs to be 0.08% or less. If Si is more than 0.08%,
During printing, ink adheres to non-image areas, making printed matter more likely to become smudged.

Furthermore, the reasons for limiting the components other than S1 among the material components of the printing aluminum alloy base plate of the present invention will be explained.

If Fe is less than 0.05%, 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 to make the crystal grains of the ingot uniform and fine, but if it exceeds 0.10%, its effect will be saturated and it will only unnecessarily increase costs.
．． It was limited to 10% or less. As a Ti addition means for this purpose, rather than using an Al-Ti master alloy, it is preferable to use Al
'-Ti = 88 It is more effective to use gold. In this case, B will be contained, but in order to prevent the generation of linear defects due to NTI B 2 particles, the B content m is set to 0.0.
It is preferable to suppress it to 2% or less.

Qu is surface 51! Cu is added to improve properties, but if added in excess of 0.03%, ink staining properties deteriorate, so the upper limit of Cu was set at 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 MOo exceeds 0.03%, the surface treatment properties deteriorate even if it coexists with Ctl, so Mg 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 ink staining property, so a normal method may be used.

In other words, in the process up to intermediate annealing, the surface of the ingot that has been semi-continuously cast is usually removed by the face side, then subjected to homogenization treatment as necessary, and heated to a predetermined temperature by hot rolling*C. The continuous casting coil is directly cast with a plate thickness of 1211 mm or less and cold rolled as it is without going through the hot rolling process. adopt. After reaching the intermediate thickness in this way, it is subjected to intermediate annealing at 300 to 550°C for 24 hours or less, followed by final cold open rolling at a working rate of 20 to 95% to obtain the necessary mechanical strength. administer. The reasons for limiting the intermediate annealing conditions are as follows. In other words, if the intermediate annealing temperature is less than 300°C, sufficient recrystallization will not occur, making it unsuitable for intermediate annealing. On the other hand, if the intermediate annealing temperature is higher than 550°C, secondary recrystallization will occur, causing the recrystallized grains to become significantly coarser, and furthermore, the surface Due to oxidation, unevenness and cracking occur, making it unsuitable as a base plate for printing. Note that the intermediate annealing temperature is actually regulated also by the relationship with the amount of Si in the material as described above. On the other hand, the intermediate annealing time is set to a maximum of 24 hours because if it exceeds 24 hours, the annealing effect will be saturated and it will only be economically disadvantageous.

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+uax1.
It was cast into a 200+ux 3500nm slab. After preparing the slab by 7mm on each side, 55mm
A homogenization treatment was performed at 0° C. for 12 hours, and then hot rolling was started at 500° C. to produce a hot-rolled sheet with a thickness of 5 mm. Next, after cold rolling to a plate thickness of 1,211,111 mm, this was intermediately annealed in a stationary annealing furnace at various temperatures shown in Table 2. The temperature increase rate during this stationary annealing was approximately 50° C./Hr, and the holding time after reaching the annealing temperature was 2 hours. Next, the coil after intermediate annealing was cold rolled to a plate thickness of 0.3a+Ill to obtain a base plate for offset printing.

After mechanically roughening each blank plate obtained in this example by brushing, it was heated in a 10% NaOH aqueous solution for 5
Preliminary etching was performed at 0° C. for 1 minute, followed by electrochemical surface roughening treatment by performing AC electrolysis at 35° C. using a nitric acid etching solution. then 15% 1-12
An anodized film is formed by anodizing in an SO4 bath, and then a photosensitive agent is applied to form an 8-layer film for offset printing.
Eight editions were produced. After this is subjected to prescribed exposure and development processing,
Burning treatment was performed 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 regarding ink stains of these invention alloys and comparative alloys. Regarding the ink stain resistance, stains in non-image areas after printing 100,000 copies were checked, and the results were classified as O (good) and × (poor).

As shown in Table 2, it is clear that the aluminum alloy base plates for printing within the scope of the present invention (sample numbers 1 to 5°7.8) have excellent ink stain resistance. On the other hand, the comparative example alloy (sample number 6.9.10.11) has a Si content of more than 0.08%, and therefore has poor ink stain resistance.

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 alloy base plate of the present invention has excellent ink stain resistance, and can effectively prevent printed matter from staining due to ink adhering to non-image areas during printing. When printing with a printing 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.

Applicant: Sky Aluminum Co., Ltd. Fuji Photo Film Co., Ltd. Agent Patent Attorney Fyo 1) Hisashi Take (1 idiot)

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, 3i 0.08% or less (weight 51 or less) or less, Fe O, 05 to 1.0%, Cu O, 0
3% or less, Ti 0.10% or less, MQ as an impurity
An aluminum alloy base plate for printing, characterized in that the aluminum alloy base plate contains 0.03% or less, and the remainder is unavoidable impurities and AI.