JPH06272015A - Production of aluminum sheet for film laminating - Google Patents

Abstract

PURPOSE:To obtain an aluminum sheet for film laminating improved in the adhesion of a film thereto, excellent in formability and suitable for a vessel, capacitor case material, rice cooking jar or the like. CONSTITUTION:The surface of an aluminum sheet is cleaned by mineral acid or organic acid or their mixed acid or an alkali soln. or water of 40 to 100 deg.C and is thereafter annealed in the temp. range of 250 to 650 deg.C for >=2hr in the air to produce the aluminum sheet for film laminating in which the thickness of an oxidized film on the surface is >=20Angstrom .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a container, a condenser case.
TECHNICAL FIELD The present invention relates to an aluminum plate for film lamination suitable for applications involving deep drawing such as stainless steel, rice cooker inner pot and the like. In the present invention, "aluminum" means pure aluminum and an aluminum alloy, and "aluminum plate" means a pure aluminum plate and an aluminum alloy plate.

[0002]

2. Description of the Related Art Conventionally, in the production of film-laminated aluminum sheets used for containers, condenser casing materials, rice cooker inner pots, etc., aluminum sheets produced by casting and rolling are generally improved in deep drawing formability. For this purpose, it is annealed in a furnace to be softened to obtain an O material, and then a resin film is laminated. By annealing in an atmosphere containing oxygen in this way, an oxide film is formed on the surface of the aluminum plate. Since this oxide film exhibits excellent performance of improving the adhesion to the film, the aluminum plate for film lamination As such, the presence or absence of an oxide film and the quality of the condition are important factors.

[0003]

[Problems to be Solved by the Invention] Conventionally, in the above-mentioned softening annealing, since the rolled plate is annealed in the furnace as it is, stains such as rolling oil and metal powder adhered to the surface of the rolled plate are annealed. In many cases, seizure occurred, which resulted in defects such as poor appearance and poor adhesion. In order to remove the baking of the rolling oil, metal powder, etc., cleaning treatment such as acid cleaning, alkali cleaning, and hot water cleaning is performed after annealing.
Even the oxide film formed during annealing is removed, and as a result, there is a problem that the adhesion to the film is reduced. In order to make up for this lost oxide film, mechanical surface roughening treatment, anodizing treatment, hydration oxidation treatment, electrolytic treatment, etc. may be carried out after cleaning, but the number of steps increases and the cost increases. was there. Further, annealing is also performed after providing an oxide film after rolling, and for example, the invention described in JP-A-63-143290 discloses that a cold-rolled sheet is mechanically roughened and then anodized or A hydration oxidization treatment was applied to make the coating amount ≦ 50 mg / dm 2, and then
A synthetic resin film is formed on the heat-conditioned surface. In the invention described in JP-A-63-126728, a hydrated oxide film layer is provided on the surface of an aluminum plate, a thermoplastic fluororesin layer is formed on the surface, and then a tetrafluoroethylene resin film is formed. . After rolling such an aluminum plate, an oxide film or the like is provided on the surface by treatment such as anodic oxidation, then heat treatment is performed to heat the aluminum plate, and then a synthetic resin film is formed. There is a problem in that the process of providing the above is complicated, and the processing time is long, so that the cost is increased.

The present invention does not require a treatment such as providing an oxide film on the surface of the aluminum plate before and after annealing, and an oxide film formed on the surface of the aluminum plate in the annealing step which is an essential step for producing the O material. It is intended to obtain an aluminum plate which has no poor appearance and is excellent in adhesiveness with a film at a low cost by effectively utilizing.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the inventors have made earnest research efforts on the component composition of the material, the mechanical or surface characteristics, and the manufacturing method, and as a result, have accomplished the present invention. That is, the present invention is

For laminating films, the surface of the aluminum plate is washed and then annealed in the temperature range of 250 to 650 ° C. for 2 hours or more, and the thickness of the oxide film on the surface is 20 Å or more. A method of manufacturing an aluminum plate,

The surface of the aluminum plate is washed with a mineral acid, an organic acid or a mixed acid thereof, and then 250 to 65 in air.
A method for producing an aluminum plate for film lamination, which comprises annealing at a temperature range of 0 ° C. for 2 hours or more, and a thickness of an oxide film on the surface is 20 Å or more,

The surface of the aluminum plate is washed with an alkaline solution and then annealed in the temperature range of 250 to 650 ° C. for 2 hours or more, and the thickness of the oxide film on the surface is 20 angstroms or more. A method for manufacturing an aluminum plate for film lamination,

The surface of the aluminum plate is washed with water at 40 to 100 ° C., then annealed in the temperature range of 250 to 650 ° C. for 2 hours or more, and the thickness of the oxide film on the surface is 20 angstroms or more. And a method for producing an aluminum plate for film lamination.

As described above, according to the present invention, prior to annealing, the aluminum plate is washed in advance to remove stains such as rolling oil and metal powder adhering to the surface thereof, and then annealed, so that the entire surface of the aluminum plate is clean and uniform. It is a manufacturing method for forming a transparent oxide film.

The cleaning methods include 1) cleaning with an acidic aqueous solution, 2) cleaning with an alkaline aqueous solution, and 3) cleaning with hot water. Each of them will be described below in sequence.

1) As washing with an acidic aqueous solution, dipping washing or spray washing with an aqueous solution of one of mineral acids such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, etc., or organic acids such as sulfonic acid, or a mixed acid thereof. After that, wash with water. The acid concentration, bath temperature, and time may be appropriately selected from the line speed, the degree of contamination, etc., but the acid concentration is about 1 to 60 wt%, the bath temperature is room temperature to 90 ° C, and the cleaning time is 1 second to A few minutes is good. Considering productivity, lining of the apparatus and the like, it is preferable that the concentration is 2 to 30 wt%, the bath temperature is 30 to 80 ° C., and the time is about 2 to 30 seconds. In addition, in order to further improve the detergency, HLB in the above acidic aqueous solution is about 8-14.
A surfactant such as polyoxyethylene alkylphenyl ether and a chelating agent such as EDTA may be added to a certain extent.

2) For cleaning with an alkaline solution,
Immersion washing in an aqueous solution of one or a mixture of caustic soda, alkali metal hydroxide such as potassium hydroxide, phosphate such as trisodium phosphate, carbonate such as sodium carbonate Alternatively, after spray-washing, it is washed with water.
The alkali concentration, bath temperature, and time may be appropriately selected depending on the line speed, the degree of contamination, etc.
The bath temperature may be about 50 wt%, the room temperature to about 90 ° C., and the cleaning time may be about 1 second to several minutes. Especially considering productivity, lining of equipment, etc., concentration = 2 to 30 wt%,
The bath temperature is preferably 30 to 80 ° C. and the time is preferably 2 to 30 seconds. In order to further improve the detergency, a surfactant such as polyoxyethylene alkyl ether having an HLB of about 8 to 14 and a chelating agent such as sodium gluconate may be added to the alkaline aqueous solution. . After washing with an alkaline aqueous solution, washing with an acidic aqueous solution as described in 1) may be further performed.

3) As the washing with hot water, immersion washing or spray washing with tap water, industrial water, soft water, pure water or the like is performed. The water temperature and the washing time may be appropriately selected from the line speed, the degree of dirt, etc., but the water temperature is about 40 to 90 ° C.
The cleaning time may be about 1 second to several minutes. Considering the productivity, the lining of the apparatus, etc., the bath temperature = 50 to 80 ° C., and the time is preferably 2 to 60 seconds. In order to further improve the detergency, a surfactant such as sodium alkylbenzenesulfonate and a chelating agent such as EDTA · 2Na may be added. However, in this case, it is preferable to wash with hot water or hot water containing no water after washing with hot water.

The annealing after cleaning has an annealing temperature of 250 to 65.
0 ° C., preferably about 350 to 550 ° C. is good, and the annealing time is sufficient if an oxide film is formed to the extent that sufficient adhesion with the film to be laminated is satisfied. Is preferred.

As the film to be laminated, a polyester film such as polyethylene terephthalate, an acrylic resin film such as polyacrylic acid and methacrylic acid, a polyamide / polyamino film such as nylon, a fluorine resin film such as ethylene tetrafluoride, and a bispheno -Examples include epoxy resin films such as type A resin. Also, a urethane-based, acrylate-based, epoxy-based or olefin-based glue may be applied.

The thermocompression bonding conditions of the laminated film cannot be specified because they vary greatly depending on the characteristics of the film even if they are made of the same material, but generally pressure = 1 to 10 kg / cm @ 2, temperature = 50 to 350.degree. C., time = 1. About 20 minutes is good.

[0018]

The oxide film is formed on the aluminum surface by annealing the aluminum plate in an atmosphere containing oxygen. The structure of this oxide film changes depending on the annealing temperature,
When annealed at a high temperature of 250 ° C. or higher, an oxide film having an activity such as γ-alumina is formed, and this film has a high bonding strength with the functional groups of the laminated polymer film, and therefore exhibits high adhesion. However, when rolling oil or the like adheres to the surface of the aluminum plate, not only the binding of the rolling oil to the polymer film is hindered due to seizure of the rolling oil but also the diffusion of oxygen to the aluminum surface-the formation of an oxide film itself. However, because of this, an oxide film that is very thin or has gaps is partially formed, and the adhesion is reduced. Moreover, since some of the rolling oil components on the surface of the aluminum plate remain even if the temperature exceeds 600 ° C., it cannot be removed at the annealing temperature (250 to 550 ° C.) that is usually performed, and the aluminum alloy type Many of them have a melting point of 600 ° C. or lower, and therefore, it is practically impossible to remove them during annealing. On the other hand, as in the present invention, cleaning is performed prior to annealing to remove rolling oil, metal powder, and the like, and then annealing is performed so that oxygen diffusion to the aluminum surface is not hindered, and thus the oxide film The formation is promoted and the entire surface of the plate is covered with a uniform oxide film, so that high adhesion can be obtained.

As a cleaning method prior to annealing, any of the cleaning with an acidic aqueous solution, the cleaning with an alkaline aqueous solution and the cleaning with warm water may be used as described above, but each method has the following characteristics, and which method is used. Whether or not to adopt should be decided in consideration of the degree of contamination of the aluminum plate, equipment cost, and the like.

The cleaning with an acidic aqueous solution has a moderate cleaning power, but unlike the alkaline cleaning, it hardly causes smut. However, the equipment requires an acid-resistant lining or material, and it is necessary to take measures against mist scattering, which makes the installation cost of the treatment equipment expensive. Cleaning with an alkaline aqueous solution is efficient because it has a strong cleaning power and acts to saponify oil. However, smut tends to adhere, which may adversely affect the adhesiveness. Cleaning with warm water can be performed with simple equipment and is low cost. It is also advantageous in terms of environmental pollution, waste liquid treatment, and working environment. However, the cleaning power is the weakest of the three cleaning methods.

When the annealing temperature is less than 250 ° C., the formation of an oxide film on the surface is insufficient. On the other hand, when it exceeds 650 ° C., the temperature is close to the melting point of the aluminum plate, so that the softening of the plate becomes severe or partial melting starts, which causes the manufacturing process It becomes a problem. Therefore, the annealing temperature is set to 250 to 650 ° C. Within this range, the temperature range of 350 to 550 ° C. is particularly preferable, in which the production of oxides progresses uniformly and rapidly and there is no problem such as softening of the plate. The annealing time may be selected as long as an oxide film is formed to the extent that sufficient adhesion with the film to be laminated is satisfied, and may be appropriately selected, but is preferably 2 to 30 hours. If it is less than 2 hours, the formation of oxide is generally insufficient, which is not preferable, and even if the annealing is performed for more than 30 hours, the formation of oxide is saturated and energy is merely consumed, and more oxide is produced. It is useless because it is not done. Therefore 2
-30 hours is preferred. The adhesiveness with the aluminum surface and the adhesiveness with the oxide film differ depending on the material of the film to be laminated, and thus the required oxide film thickness varies. For this reason, it is desirable to select as appropriate within the above temperature range and time range.

When the annealing condition is a condition of holding at high temperature for a short time,
A CAL (continuous annealing furnace) or the like will be used. However, the container, the capacitor case material, which is the application of the present invention,
In the rice cooker inner pot and the like, a thin aluminum plate for film lamination is often used. Especially in a capacitor case, the plate thickness is as thin as 0.3 mm or less. Less 10
There are many 00 series, and the material is often softened to be an O material. In this way, since the alloys are both soft and soft, and the plate thickness is thin, flexing deformation for softening is caused by the method of annealing while applying tension such as CAL (continuous annealing furnace) while passing through the plate. As a result, problems such as scratches on the inner wall of the furnace or plate breakage due to excessive tension occur. In the present invention, the annealing condition is 250 to 650.
CAL (continuous annealing furnace) by keeping the temperature at ℃ for 2 hours or more
It is not necessary to use, and since it is possible to perform annealing in a normal batch furnace, there is no occurrence of bending, abrasion, plate breakage, etc. when annealing the above soft material by CAL,
Therefore, even if a thinner plate is required in the future, it can be manufactured without any problem.

[0023]

EXAMPLES Examples of the present invention will be described below.

[0024]

[Table 1]

(Example 1) A JIS 1100 aluminum plate was cold-rolled into a plate material having a thickness of 0.3 mmt.
After washing with an acid aqueous solution under the conditions listed in (1), it was annealed in the air at 500 ° C. for 8 hours to obtain an O material. Table 1 shows the oxide film thickness of the test material obtained at this time. After that, a fluororesin film having a thickness of 30 μm is applied to this plate under pressure = 7 kg /
A laminate was prepared by thermocompression bonding under the conditions of cm2, temperature = 300 ° C. and time = 10 minutes. This laminated plate was molded at a total squeeze rate of 40% to obtain a cylindrical container having a diameter of 5 mm and a height of 11 mm.
After this cylindrical container was trimmed, it was immersed in perchlorethylene held at 125 ° C. (boiling point) for 15 minutes and the state of film adhesion at the cut edge was observed. In all cases, there was no peeling of the resin film and it was good.

(Example 2) A JIS 1100 aluminum plate was cold-rolled into a plate material having a thickness of 0.3 mmt.
After being washed with an alkaline aqueous solution under the conditions listed in (3), it was annealed in the air at 450 ° C. for 3 hours to obtain an O material. Table 1 shows the oxide film thickness of the test material obtained at this time. After that, press a nylon resin film with a thickness of 30 μm on this plate.
A laminate was prepared by thermocompression bonding under the conditions of 5 kg / cm @ 2, temperature = 230.degree. C. and time = 10 minutes. This laminated plate was molded at a total squeeze rate of 40% to obtain a cylindrical container having a diameter of 5 mm and a height of 11 mm. After this cylindrical container was trimmed, it was immersed in perchlorethylene held at 125 ° C. (boiling point) for 15 minutes and the state of film adhesion at the cut edge was observed. In all cases, there was no peeling of the resin film and it was good.

(Example 3) A JIS 1100 aluminum plate was cold-rolled into a plate material having a thickness of 0.3 mmt, which was washed with hot water under the conditions shown in Table 1 and then subjected to 3 in the atmosphere.
It was annealed at 50 ° C. for 16 hours to obtain an O material. Table 1 shows the oxide film thickness of the test material obtained at this time. Thereafter, a PET resin film having a thickness of 30 μm was thermocompression bonded to this plate to produce a laminated plate. This laminated plate was molded at a total squeeze rate of 40% to obtain a cylindrical container having a diameter of 5 mm and a height of 11 mm. After this cylindrical container was trimmed, it was immersed in perchlorethylene held at 125 ° C. (boiling point) for 15 minutes, and the state of film adhesion at the cut edge was observed. All were good with no peeling of the resin film.

(Comparative Example 1) A JIS 1100 aluminum plate was cold-rolled into a plate material of 0.3 mmt, which was directly washed in the air at 500 ° C. for 8 hours at 450 ° C. without washing.
Annealing was performed for 3 hours at 350 ° C. for 16 hours to obtain an O material. Table 1 shows the oxide film thickness of the test material obtained at this time. Then, a fluorine-based, nylon-based, and PET-based resin film having a thickness of 30 μm was laminated on each of these plates under the same conditions as in the example to produce a laminated plate. This laminated plate was molded at a total squeeze rate of 40% to obtain a cylindrical container having a diameter of 5 mm and a height of 11 mm. After trimming this cylindrical container, it was immersed in perchlorethylene held at 125 ° C (boiling point) for 15 minutes,
When the state of film adhesion on the cut surface was observed, the resin film peeled off in all cases.

(Comparative Example 2) A JIS 1100 aluminum plate was cold-rolled into a plate of 0.3 mmt, which was washed under the conditions shown in Table 1 and then heated at 250 ° C. in the atmosphere at 30 ° C.
Minute annealing was performed to obtain an O material. Table 1 shows the oxide film thickness of the test material obtained at this time. Then, a fluorine-based, nylon-based, and PET-based resin film having a thickness of 30 μm was laminated on each of these plates under the same conditions as in the example to produce a laminated plate. This laminate was molded at a total squeeze rate of 40% and had a diameter of 5
mm and a height of 11 mm. After trimming this cylindrical container, it was immersed in perchlorethylene held at 125 ° C. (boiling point) for 15 minutes and the state of film adhesion at the cut edge was observed.

[0030]

According to the present invention, the surface of an aluminum plate is acid-cleaned, alkali-cleaned or hot-water rinsed prior to annealing, and then subjected to an annealing step at 250 ° C. or higher, which is essential for converting the aluminum material into an O material. Suitable for containers, capacitor case materials, rice cookers, etc. because an oxide film with good adhesion to the film can be uniformly formed on the surface of the aluminum plate without unevenness, thus improving the film adhesion and excellent moldability. An aluminum plate for film lamination can be obtained. Further, since the oxide film formed during annealing can be effectively used, there is no need to perform additional surface treatment such as electrolytic treatment or surface roughening treatment after annealing, so that the process is simplified as a whole and the productivity is improved. Further, since a batch furnace can be used as the annealing condition, no extra tension is applied to the aluminum plate, and therefore, the aluminum plate can be manufactured without any trouble even when it is thin.

Claims (4)

[Claims] 1. A film characterized in that the surface of an aluminum plate is washed and then annealed in the temperature range of 250 to 650 ° C. for 2 hours or more in the atmosphere, and the thickness of the oxide film on the surface is 20 angstroms or more. Manufacturing method of aluminum plate for lamination. 2. The surface of the aluminum plate is washed with a mineral acid, an organic acid or a mixed acid thereof, and then 250 to 6 in the atmosphere.
A method for producing an aluminum plate for laminating a film, which comprises annealing at a temperature range of 50 ° C. for 2 hours or more, and the thickness of an oxide film on the surface is 20 Å or more. 3. The surface of an aluminum plate is washed with an alkaline solution and then annealed in the temperature range of 250 to 650 ° C. for 2 hours or more, and the thickness of the oxide film on the surface is 20 angstroms or more. And a method for producing an aluminum plate for film lamination. 4. The surface of the aluminum plate is 40 to 100 ° C.
Washed with water, and then annealed in the temperature range of 250 to 650 ° C. for 2 hours or more so that the thickness of the oxide film on the surface is 20.
A method for producing an aluminum plate for film lamination, which is not less than angstrom.