JPH1053847A - Production of resin-coated aluminum alloy sheet for can made by deep drawing and ironing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the fracture of a can wall at the time of executing dry type working by deciding the compsn. of an alloy, the kinds of resin and surface treatment or the like. SOLUTION: An Al alloy ingot contg., by weight, 0.01 to 1.0% Mn, 2.0 to 6.0% Mg, 0.05 to 0.4% Si, <=0.7% Fe and <=0.9% Si+Fe is subjected to prescribed homogenizing treatment, hot rolling, continuous annealing and cold rolling, and after that, surface treatment is executed. The surface treatment is executed preferably by etching and/or electrolytic chromating treatment. The surface-treated alloy sheet is heated to regulate the sheet temp. to 220 to 300 deg.C, and both sides thereof are coated with thermoplastic resin. As the resin, polyester resin is suitably used. Finally, it is rapidly cooled to the recrystallization temp. of the resin or below. As for the alloy sheet produced by the above process, at the time of executing dry type composite working including bending-rebending working and ironing in the die shoulder round part of a small shoulder round, fracture in a can wall is hard to occur, and it has required strength as a can.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a material used for a two-piece can produced by a process including drawing and ironing. More specifically, a two-piece can with a thin can wall is manufactured by processing including drawing and ironing, which does not require cooling or lubrication of water or a water-based lubricant, and does not require cleaning of the can after making. Suitable for
The present invention relates to a method for producing a resin-coated aluminum alloy plate for a drawn ironing can coated with a thermoplastic resin.

[0002]

2. Description of the Related Art As a two-piece can in which a can body and a can bottom are formed integrally, a DI can (Draw) obtained by drawing or ironing a tinplate or an aluminum alloy plate is used.
n andIroned Can) have been manufactured. DI can is tinplate or after drawing aluminum alloy plate,
Using several ironing dies and punches arranged continuously, cooling and lubricating with a large amount of water or water-based lubricant to reduce the wall thickness of the can to about 1/3 of the original plate thickness, followed by degreasing , Dried and painted. In recent years,
Japanese Patent No. 310223 discloses a method of manufacturing a two-piece can from a resin-coated metal plate by a combined processing method including drawing and ironing. This method differs from the conventional method for manufacturing DI cans in that after drawing a resin-coated metal plate coated with a high-temperature volatile lubricant, dry drawing and ironing are performed without using water or an aqueous lubricant. A two-piece can having a thin can wall is manufactured by a combined processing method in which the processing is performed simultaneously. According to this composite processing method, the steps of degreasing, washing, drying, and painting the can after forming it into a two-piece can become unnecessary, and a two-piece can can be manufactured without polluting the environment. The present invention has been studied for the purpose of providing a resin-coated aluminum alloy sheet suitable for this composite processing method. Regarding materials suitable for the composite processing method, Japanese Unexamined Patent Publication No. Hei 7-266496 discloses a yield strength,
Materials having limited tensile strength, plate thickness, center line roughness, etc. are disclosed, and JIS 5052 H38 and JIS
The use of 3004 H19 aluminum alloy is shown.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a method disclosed in
It is an object of the present invention to provide a resin-coated aluminum alloy plate suitable for a composite machining method as disclosed in JP-A-313223. The composite machining method targeted by the present invention is a machining method in which redrawing and ironing are performed simultaneously using a die in which a redrawing portion and an ironing portion are paired. One of the features of the combined machining method is to reduce the size of the shoulder radius of the die where redrawing is performed, and to bend and bend back the material at this die shoulder radius to reduce the thickness of the can wall. is there. In this combined machining, the thickness of the machined
Since severe bending and bending back processing is performed with a small die shoulder radius of about several times, the surface of the material is likely to be rough and cracked, and depending on the processing conditions, the can wall is broken at the die shoulder radius. Further, even in the case where no break occurs at the die shoulder radius portion, the rough surface and the surface crack cause a decrease in the adhesion between the coated resin film and the aluminum alloy plate, and the can wall break is extremely likely to occur in the subsequent ironing.
According to the present invention, when performing a bending / rebending process at a die shoulder radius portion of a small shoulder radius and a subsequent complex process including an ironing process in a dry manner, the can wall is hardly broken and has a necessary strength as a can. An object of the present invention is to provide a method for manufacturing a resin-coated aluminum alloy plate used as a can body. Further, the resin-coated aluminum alloy plate manufactured by using the manufacturing method of the present invention is a commercially available aluminum DI plate.
One of the issues is that can body materials used for cans can be easily reused. The JIS 3004H19 alloy disclosed in the examples of JP-A-7-266496 has the required strength, but the workability is insufficient for the purpose of the present invention. On the other hand, JIS5052H38 alloy is suitable for the complex working method aimed at by the present invention because of its workability, but has a small allowable Mn amount and greatly limits the amount of scrap of 3004 alloy that can be put into production of this alloy. That is, the reuse of scrap is restricted.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method for preparing M
n: 0.01 to 1.0%, Mg: 2.0 to 6.0%, Si:
0.05 to 0.4%, Fe: ≦ 0.4 as an inevitable impurity.
An aluminum alloy ingot containing 7% and having a relationship of (Si + Fe): ≦ 0.9% is subjected to a homogenizing heat treatment, and then hot-rolled by a conventional method to form a hot-rolled sheet, followed by continuous annealing. Performing a cold rolling process at a rolling rate of 60 to 95%, then performing a surface treatment process, heating the surface-treated aluminum alloy plate to 240 to 350 ° C. within 1 minute, and then forming an aluminum alloy plate plate 220 ~
This is a method for producing a resin-coated aluminum alloy plate for a drawn and ironed can, comprising a step of coating both surfaces with a thermoplastic resin at a temperature of 300 ° C. and a step of quenching after coating. Further, in the present invention, Mn: 0.01 to 1.0% by weight, Mg: 2.0% by weight%.
0-6.0%, Si: 0.05-0.4%, Fe: ≦ 0.7% as an unavoidable impurity, and (Si + F
e): After homogenizing and heat-treating an aluminum alloy ingot having a relationship of ≦ 0.9%, a step of hot rolling by a conventional method to form a hot-rolled sheet, a step of subsequently performing box-shaped annealing, and then a rolling reduction of 6%
A step of cold rolling at 0 to 95%, a step of surface treatment, and a step of subjecting the surface treated aluminum alloy sheet to 240 to 3%.
Resin coating for drawing and ironing can consisting of a step of heating to 50 ° C within 1 minute, a step of setting the temperature of the aluminum alloy sheet to a temperature of 220 to 300 ° C, and coating both sides with a thermoplastic resin, and a step of quenching after coating. This is a method for manufacturing an aluminum alloy plate. Furthermore, the present invention is characterized in that the thermoplastic resin to be coated is a thermoplastic polyester resin,
The surface treatment applied to the aluminum alloy plate is etching and / or electrolytic chromic acid treatment, or furthermore, phosphoric acid chromate treatment.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has been extensively studied in order to provide a method for producing a resin-coated aluminum alloy sheet which is excellent in strength, workability, adhesion, and excellent in dry drawing and ironing workability. The present invention has developed a manufacturing method capable of obtaining a target resin-coated aluminum alloy plate by determining the alloy composition, the type of thermoplastic resin, and the type of surface treatment. Hereinafter, the present invention will be described in detail with reference to examples.

First, the reason for limiting the alloy components and the like of the aluminum alloy plate serving as the coated substrate of the resin-coated aluminum alloy plate in the present invention will be described below. In addition,% of each alloy component is shown by weight%. In the present invention, in order to make it easy to mix, melt and reuse the scrap generated during the production of the aluminum alloy plate and the scrap of the used aluminum can, it is necessary to use the can body material of the aluminum DI can 3004. The alloy and the alloy components of the 5052 alloy as the cover material, particularly the amounts of Mn and Mg were considered. According to the JIS standard, 3004 material has Mn: 1.0 to 1.5%, M
g: 0.8-1.3%, 5052 material is defined as Mn: 0.1% or less, Mg: 2.2-2.8%. It is assumed that the Mn content of the aluminum alloy plate serving as the coated substrate of the resin-coated aluminum alloy plate of the present invention can include the Mn content of the lower limit of 3004 alloy. This makes it possible to significantly increase the mixing ratio of the abundant scrap of the 3004 alloy when producing the aluminum alloy used in the present invention.

[Mn] Mn is inexpensive and is added to obtain strength, but if it is less than 0.01%, the effect is insufficient. On the other hand, regarding the upper limit of the addition amount, it is assumed that the scrap of the can body material is mixed and reused, and the addition amount is assumed to be in the range of 1.0% or less of the lower limit of the 3004 alloy. Al-Fe-Mn crystallized substances are formed by the addition of Mn.
The hard α phase, which is a transformation product, is not preferable for the bending / unbending workability which is the subject of the present invention. In commercially available aluminum DI processing, an Al—Fe—Mn crystallized substance has a lubricating action during ironing, and is indispensable for improving ironing workability. However, in the present invention, since an aluminum alloy plate whose surface is coated with a resin is processed, the lubricating action of the Al-Fe-Mn-based crystallized substance is not necessary, but rather the workability is impaired. That is, the crystallized product is not suitable for the composite working method for applying the resin-coated aluminum alloy sheet of the present invention. The compound processing method is
Redrawing and ironing are performed simultaneously using a pair of dies with a redrawing part and an ironing part, and the shoulder radius of the redrawing die is set to a small shoulder radius several times less than the plate thickness. However, the crystallized material significantly impairs the bendability / returnability at the die shoulder radius portion. That is, the surface of the aluminum alloy is easily roughened and cracked at the time of bending / unbending, and the adhesion of the coating resin film based on the roughness is lowered. In addition, the amount, size,
Depending on the processing conditions, the can wall is broken. Therefore, the upper limit of the amount of Mn is set to 1.0% in consideration of the amount of Mg described below.

[Mg] Mg is an element that is more effective than Mn in improving the strength, and is added to obtain the necessary strength as a can. However, when the added amount increases, the workability decreases. In the present invention, the upper limit of the Mn content is set to 1.0% for the above-mentioned reason.
However, it is not in the range where the workability is sufficient. Therefore, the range of the Mg content is set to 2.0 to 6.0% in order to reduce the deterioration of the workability and the fluctuation of the workability. When the Mn content is near the upper limit of 1.0% of the present invention, Mg
If it exceeds 6.0%, the workability becomes poor, and it becomes difficult to apply it to severe processing applications. On the other hand, if the Mg content is less than 2.0%, the strength becomes insufficient, and the economic efficiency is improved. The two-piece can formed by molding the resin-coated aluminum alloy plate according to the present invention by using the above-described composite processing is applied to contents in which the internal pressure of the can is positive, such as beers, carbonated beverages, and beverages filled with nitrogen gas. However, the internal pressure of the can differs depending on the contents. For this reason, a material having a large amount of Mn and Mg is applied to a material for a can filled with a content having a high internal pressure of the can. If the pressure resistance of the can bottom is insufficient, the can bottom will buckle and become unusable as a product. The yield strength and thickness of the sheet mainly affect the pressure resistance of the can bottom. When the yield strength is low, it is necessary to increase the thickness of the sheet, but the economic efficiency is impaired. For this reason, from the viewpoint of economic efficiency, it is conceivable to use a high-strength material with a large thickness of Mn or Mg added. descend. The aluminum alloy of the present invention has a higher Mg content than that of a general aluminum alloy for cans and can provide high strength, but the workability is somewhat insufficient. Therefore, it is desirable to reduce the thickness of the sheet during the manufacture of the sheet and to reduce the degree of processing in the combined processing.

Si causes a phase transformation in the Al—Fe—Mn crystallized product to form a so-called hard α phase. This α phase needs to be added in an amount of 0.1% or more in order to improve ironing workability in the production of DI cans, but for the present invention, the bendability / return workability is higher than that of the crystallized material before the phase transformation. Is not preferred. Therefore, the lower limit is set to 0.05% from the viewpoint of strength increase, and the upper limit is set to 0.4% from the viewpoint of workability.

[Fe] Fe is related to Mn, and Al—Fe
-Form Mn-based crystals. As described above, the Al-Fe-Mn system is not preferable for the present invention from the viewpoint of bending and bending-back workability, and the upper limit of Fe, which is an element forming the Al-Fe-Mn system, is set to 0.1.
7%. Preferably, it is 0.4% or less.

The amount of [Si + Fe] (Si + Fe) is also
An upper limit is set to reduce the amount of the Fe-Mn-based crystallized product, particularly the amount of the hard α phase, to a low level. The upper limits of the amounts of Fe and Si are determined as described above.
l-Fe-Mn crystallized substances impair workability. Therefore, the upper limit is set to 0.9%, preferably 0.5% or less.

[Cu] Cu is Al-Cu-M together with Mg.
It shows precipitation hardening due to g-based precipitates, is effective from the viewpoint of increasing strength, and requires addition of 0.05% or more. However, when the addition amount is large, the workability is reduced. It is preferably at most 0.4%, more preferably at most 0.2%. There is no particular limitation on Zn, but the addition of Zn has an effect of appropriately dispersing the crystallized substance, and is preferably contained in an amount of 0.01 to 0.5% in order to reduce the adverse effect of the crystallized substance.

Next, the manufacturing method of the present invention will be described. An aluminum alloy having the above chemical components is melted and cast by a conventional method, and the obtained ingot is subjected to a homogenizing heat treatment before hot rolling. This homogenization heat treatment aims at homogenization of micro-segregation, precipitation of supersaturated elements, and the like, homogenization of the material, and improvement of hot rollability thereafter. If the temperature is lower than 500 ° C., the effect is insufficient. If the temperature exceeds 600 ° C., the performance of the plate surface is deteriorated due to burning or the like. The holding time in the above temperature range is preferably 1 hour or more.

Subsequent to the homogenizing heat treatment, hot rolling is performed by a conventional method. The temperature at the time of hot rolling is not particularly limited, but the hot start temperature is preferably in the range of 400 to 520 ° C, and the finish rolling temperature is preferably in the range of 230 to 350 ° C.

After the above hot rolling, continuous annealing or box annealing is performed. The heating rate and the cooling rate when performing continuous annealing are preferably 100 ° C./min or more. If the temperature is lower than 100 ° C./min, the crystal grains become coarse and the strength and workability become insufficient. The heating temperature is 400 to 580 ° C.
If the temperature is lower than 400 ° C., recrystallization is insufficient and workability is not improved. On the other hand, if the temperature exceeds 580 ° C., the surface of the plate burns, and the surface properties deteriorate. Further, if the heating is performed for more than 5 minutes, the material softens, and the required strength cannot be obtained.

If the annealing is performed by box-shaped annealing, 300 to 4
After keeping the temperature uniform at a temperature of 00 ° C. for 30 minutes to 5 hours, it is gradually cooled. If the heating temperature is lower than 300 ° C., recrystallization becomes insufficient. On the other hand, if the temperature exceeds 400 ° C., the crystal grains become abnormally coarse, which is not preferable. If the soaking time is less than 30 minutes, the inside of the coil is insufficiently heated. If the soaking time is more than 5 hours, it becomes not only economical but also extremely soft, which is not preferable.

After performing any of the above annealing treatments, cold rolling is performed. The rolling ratio is preferably in the range of 60 to 95%. After cold rolling under these conditions, 1
Heat treatment for up to a minute. As the rolling ratio increases, the crystallized material is stretched in the rolling direction, voids are formed around the crystallized material, and processing strain is accumulated, and the bending / unbending workability is reduced. Therefore, the upper limit of the rolling ratio is set to 95% from the viewpoint of workability. In order to obtain the required strength, the lower limit of the rolling reduction is 60.
%. Before coating the resin after surface treatment,
In order to recover the decrease in workability due to the rolling process, 2
Heat at 40 to 350 ° C. for 1 minute or less. The lower limit of the heating temperature is 240 ° C. for recovery, and the upper limit is 350 ° C. to prevent recrystallization. The heating time at the above-mentioned temperature is set to 1 minute or less because the heating equipment for which the heating time is long becomes long and the required strength cannot be obtained due to the progress of softening. Heating is performed immediately before the resin coating step, and after heating to the above-mentioned temperature, it is economical to coat the resin at a predetermined temperature in the cooling process.

After being subjected to the above cold rolling, the aluminum alloy plate is subjected to a known method such as anodizing treatment, immersion chromic acid treatment, phosphoric acid chromate treatment, etching treatment with an alkali solution or an acid solution, electrolytic chromic acid treatment and the like. Although a surface treatment is performed, an etching treatment and / or an electrolytic chromic acid treatment or a phosphoric acid chromate treatment is more preferable in the present invention. In particular, when forming a two-layer film composed of metallic chromium and chromium hydrated oxide on an aluminum alloy plate by electrolytic chromic acid treatment, the amount of chromium hydrated oxide is determined from the viewpoint of processing adhesion of the laminated resin film. may be a 3~50mg / m ² as chromium, 7~40mg / m ²
Is more preferable. The metallic chromium amount need not be particularly limited, the corrosion resistance after processing, preferably in the range of 1 to 100 mg / m ² from the viewpoint of processability adhesion between the resin film to be laminated, in the range of 5 to 30 mg / m ² More preferred. When phosphoric acid chromate treatment is performed, the amount of the formed chromate film is 3 to 30 mg / m ² as chromium.
And the range of 5 to 20 mg / m ² is more preferable.

Next, in the present invention, the thermoplastic resin laminated on at least one side of the aluminum alloy plate includes:
It is possible to use a single-layer or multi-layer resin film containing polyester resin, polyolefin resin, polyamide resin, polycarbonate resin, etc. as a main component, a resin film obtained by blending two or more of these resins, or a resin film obtained by copolymerization. it can. Particularly for drawn ironing cans subjected to severe molding processing of the present invention, polyethylene terephthalate, copolymerized polyester resin mainly composed of ethylene terephthalate repeating units, polybutylene terephthalate, polyester resin mainly composed of butylene terephthalate repeating units, or Either a polyester resin obtained by blending at least two kinds of these polyester resins, or a multilayer polyester resin obtained by laminating at least two kinds of the above polyester resins, and further, a polycarbonate resin, or at least one polyester resin and the above polyester resin It consists of a multi-layer resin obtained by laminating at least two types of polycarbonate resin and the above-mentioned polyester resin. Stretched in two directions, biaxial orientation resin film produced by heat is preferable.

The thickness of the laminated resin film is 5 to 50.
The range of μm is preferable, and the range of 10 to 30 μm is more preferable. When the thickness is 5 μm or less, it is difficult to continuously laminate a metal plate at a high speed. On the other hand, if the thickness of the laminated resin film is 50 μm or more, it is not preferable from the viewpoint of economic efficiency as compared with an epoxy resin paint widely used as a material for cans.

The resin film may be laminated directly on the aluminum alloy plate, or may be laminated between the resin film and the aluminum alloy plate with a thermosetting adhesive such as an epoxy-phenol resin interposed therebetween. Laminating the resin film on the aluminum alloy plate with the thermosetting adhesive interposed by applying the thermosetting adhesive in advance on one side of the resin film or the aluminum alloy plate that adheres to each other Can be.

The temperature of the aluminum alloy plate when coating the resin film differs depending on the type of resin to be coated.
220-300 ° C. When the obtained resin-coated aluminum alloy plate is drawn and ironed at 220 ° C or lower,
The resin film coated with poor processing adhesion easily peels off. On the other hand, at 300 ° C. or higher, the resin film to be coated melts and adheres to a laminating roll or the like, making the coating operation impossible. For the above reasons, the upper and lower limits of the temperature of the aluminum alloy plate when coating the resin film are determined.

Next, the above-mentioned thermoplastic resin film is brought into contact with both sides of the aluminum alloy plate heated to the above-mentioned temperature, superposed between a pair of laminating rolls, sandwiched and pressed, and then immediately heated. Cool rapidly below the recrystallization temperature of the plastic tree. From the above steps, a resin-coated aluminum alloy plate for a drawn and ironed can is obtained.

As described above, a high-temperature volatile lubricant is applied to the upper surface of a thermoplastic resin film-coated aluminum alloy plate manufactured by using the manufacturing method of the present invention, and then drawn and ironed to obtain water or It is possible to manufacture a two-piece can having a thin can wall without requiring cooling or lubrication with a water-based lubricant or the like and without requiring cleaning of the can after can-making. As a high-temperature volatile lubricant, when drawing and ironing and heating at a temperature of about 200 ° C. for several minutes,
It is desirable that the particles be scattered by 0% or more. Specifically, the material is selected from liquid paraffin, synthetic paraffin, natural wax, or other simple substance, or a mixture thereof according to processing conditions and heating conditions after processing. As the characteristics of the lubricant to be applied, those having a melting point in the range of 25 to 80 ° C and a boiling point in the range of 180 to 400 ° C are desirable for achieving the object of the present invention. In addition, the application amount should be determined in consideration of the surface to be the outer surface of the can, the surface to be the inner surface of the can, processing conditions, heating conditions after processing, and the like.
A range of 100 mg / m ² , preferably 30-60 mg / m ² is suitable.

[0025]

EXAMPLE An aluminum alloy having the composition shown in Tables 1 to 3 was melted, cast, and beveled by a conventional method, and was subjected to a homogenizing heat treatment at 550 ° C. for 1 hour. Continuous annealing is performed, and thereafter, the sheet is subjected to secondary cold rolling at a rolling rate shown in Tables 1 to 3 to a sheet thickness of 0.25 mm, and the following (A) to
(D) Any surface treatment was applied. (A) [Etching treatment] An aqueous solution of sodium hydroxide (60 g / l)
After immersion for 2 seconds, washing with water, sulfuric acid at 15 ° C (15 g / l)
Immersed in water for 15 seconds, washed with water, and dried. (B) [Electrolytic chromic acid treatment] In a 40 ° C. aqueous solution comprising chromic anhydride: 100 g / l as a main component and 5 g / l of sodium fluoride as an auxiliary,
Cathodic electrolysis at a current density of 00 A / dm ² , metal chromium of 32 to 41 mg / m ² , chromium hydrated oxide of 12 to 15
A two-layer coating of mg / m ² is formed. (C) [Electrochromic treatment after etching treatment] 15% aqueous sodium hydroxide solution (50 g / l) at 60 ° C.
After immersion for 2 seconds, washing with water, sulfuric acid at 15 ° C (15 g / l)
And then rinsed with water, followed by chromic anhydride: 1
Cathodic electrolysis at a current density of 100 A / dm ^{2 in} a 40 ° C. aqueous solution containing 00 g / l as a main agent and 5 g / l of sodium fluoride as an auxiliary,
m ² , the chromium hydrated oxide comprising 7 to 11 mg / m ² 2
A layer film is formed. (D) [Phosphoric acid chromate treatment] A 60 ° C aqueous solution consisting of phosphoric acid: 70 g / l, chromic anhydride: 12 g / l, and sodium fluoride 5 g / l is sprayed, and the amount of chromium is 13 to 20 mg / m2. Form a chromate film of ² . Then, after performing a surface treatment by any of the above methods, the aluminum alloy plate was heated under the conditions shown in Tables 1 to 3, and polyethylene isophthalate was 12 mol% on both surfaces.
And a 20 μm-thick copolymerized polyester resin biaxially oriented film composed of 88 mol% of polyethylene terephthalate, and immediately immersed in water and cooled. After drying, about 50 mg of glamor wax (boiling point 115 ° C.)
/ M ^{2 was} applied to obtain a test plate. The test plate was evaluated for the strength after bending / unbending, the workability by composite processing, the pressure resistance, and the adhesion between the coated resin film after processing and the surface of the aluminum alloy plate. The strength after bending / unbending is evaluated as good when the tensile strength of the test plate subjected to bending / unbending at a bending radius of 0.5 mm is 30% or more of the strength of the test plate before processing. , Less than 30% was evaluated as x (defective). With respect to the pressure resistance, a 65 mm can can is formed by ordinary drawing, and after doming the bottom of the can, an internal pressure is applied, and the pressure at which the bottom of the can buckles is evaluated. The buckling pressure is 6.3 kg / cm. ^Two
The above cases were evaluated as ○ (good), and the cases with less than 6.3 cg / mm ² were evaluated as × (bad). The evaluation of combined workability is based on the drawing ratio 1.
100mm diameter draw can molded in 6
Processed into a primary redrawn can with a can wall thickness of 80% of the original plate thickness,
The subsequent secondary redrawability was evaluated. In the secondary redrawing process, the redrawing ratio is set to 1.15, and the redrawing die shoulder radius is 0.4 m.
m, the clearance of the ironing die was changed, and the workability at the die shoulder and the ironing part was evaluated based on the occurrence of can wall breakage during processing.If there was no can wall break, ○ (good), can The case where wall breakage occurred was evaluated as x (defective). Adhesion is evaluated by the presence or absence of peeling of the coating resin on the inner surface of the can wall after performing the secondary redrawing process under the same conditions as above, ○ without peeling (good), × with peeling (poor) And The evaluation results are shown in Tables 4 to 6.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

[0030]

[Table 5]

[0031]

[Table 6]

[0032]

According to the present invention, Mn: 0.01 to 1.
0%, Mg: 2.0-6.0%, Si: 0.05-0.4
%, Fe: ≦ 0.7% as an unavoidable impurity,
And (Si + Fe): an aluminum alloy ingot having a relationship of 0.9% is subjected to a homogenizing heat treatment, followed by hot rolling by a conventional method to form a hot-rolled sheet, and then continuous annealing or box-shaped annealing. Process, then cold-rolling at a rolling ratio of 60 to 95%, then surface-treating, heating the surface-treated aluminum alloy plate at a temperature of 240 to 350 ° C. within 1 minute, and then heating the aluminum alloy plate. A method for producing a resin-coated aluminum alloy sheet for a drawn and ironed can, comprising a step of coating a thermoplastic resin on both sides thereof at a sheet temperature of 220 to 300 ° C. and a step of quenching after coating, and (A) etching, (B) electrolytic chromic acid treatment, (C) etching, electrolytic chromic acid treatment, (D) phosphoric acid chromate treatment, (A) to (D) When performing dry and dry combined processing including bending / returning at the die shoulder radius portion of the small shoulder radius and subsequent ironing, the can wall is less likely to break. In addition, it becomes possible to manufacture a resin-coated aluminum alloy plate having the necessary strength as a can. Further, since the Mn content of the aluminum alloy plate serving as the coating substrate of the resin-coated aluminum alloy plate of the present invention can include the Mn content of the lower limit of 3004 alloy, a large amount of Can greatly increase the mixing ratio of the scrap of the 3004 alloy present in the steel, and the recyclability is excellent.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication // C22F 1/00 613 8719-4K C22F 1/00 613 630 8719-4K 630K 673 8719-4K 673 685 8719-4K 685Z 691 8719-4K 691B 8719-4K 691C

Claims (5)

[Claims] 1. Mn: 0.01 to 1.0% by weight%, M
g: 2.0-6.0%, Si: 0.05-0.4%, Fe: ≦ 0.7% as an inevitable impurity, and (Si)
+ Fe): After homogenizing and heat treating an aluminum alloy ingot having a relationship of ≦ 0.9%, a process of hot rolling by a conventional method to form a hot rolled sheet, a process of continuous annealing, and a rolling reduction of 60 to A step of performing cold rolling at 95%, a step of surface treatment, and a step of subjecting the surface-treated aluminum alloy sheet to 240%.
A step of heating the aluminum alloy sheet to a temperature of 220 to 300 ° C. and a step of coating both sides thereof with a thermoplastic resin, and a step of rapidly cooling after the coating, and a step of rapidly cooling after coating. Manufacturing method of coated aluminum alloy plate. 2. Mn: 0.01 to 1.0% by weight, M
g: 2.0-6.0%, Si: 0.05-0.4%, Fe: ≦ 0.7% as an inevitable impurity, and (Si)
+ Fe): After homogenizing and heat-treating an aluminum alloy ingot having a relationship of ≦ 0.9%, a step of performing hot rolling by a conventional method to form a hot-rolled sheet, a step of subsequently performing box-shaped annealing, and then a rolling reduction of 60% A step of performing cold rolling at ~ 95%, a step of surface treatment, and a step of subjecting the surface-treated aluminum alloy sheet to 240%.
A step of heating the aluminum alloy sheet to a temperature of 220 to 300 ° C. and a step of coating both sides thereof with a thermoplastic resin, and a step of rapidly cooling after the coating, and a step of rapidly cooling after coating. Manufacturing method of coated aluminum alloy plate. 3. The thermoplastic resin to be coated is a thermoplastic polyester resin.
The method for producing a resin-coated aluminum alloy sheet for a drawn and ironed can according to claim 1. 4. The resin-coated aluminum alloy for a drawn and ironed can according to claim 1, wherein the surface treatment applied to the aluminum alloy plate is etching and / or electrolytic chromic acid treatment. Plate manufacturing method. 5. The method for producing a resin-coated aluminum alloy sheet for a drawn and ironed can according to claim 1, wherein the surface treatment applied to the aluminum alloy sheet is a phosphoric acid chromate treatment. .