WO1998049360A1

WO1998049360A1 - Resin-coated aluminum alloy sheet for drawn and ironed cans

Info

Publication number: WO1998049360A1
Application number: PCT/JP1998/001875
Authority: WO
Inventors: Keiichi Shimizu; Fumio Kunishige
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1997-04-25
Filing date: 1998-04-23
Publication date: 1998-11-05
Also published as: AU7080598A

Abstract

A resin-coated aluminum alloy sheet which makes it possible to form drawn and ironed cans having strengths necessary for suppressing the breakage of the walls when complicated machining inclusive of bending and unbending at a die shoulder radius portion having a small shoulder radius and subsequent ironing are carried out as a dry process, and which can provide an aluminum alloy film having a sufficient adhesive strength after the machining. The sheet is manufactured by applying a silane treatment using a silane coupling agent alone or a composite treatment using both chromium phosphate and a silane coupling agent to an aluminum alloy sheet whose contents of Mn, Mg, Si, Cu, Fe and (Si+Fe), thickness and yield strength are controlled to be in predetermined ranges and then coating the sheet with a thermoplastic resin.

Description

Description Resin-coated aluminum alloy plate for drawing and ironing cans

5 Technical fields

The present invention relates to a material used for a two-piece can manufactured by processing including drawing and ironing. More specifically, a two-piece can with a thin can wall can be formed by processing including squeezing and ironing, which does not require cooling or lubrication with water or a water-based lubricant, and does not require cleaning of the can after making. Aluminum alloy plate with a surface treatment suitable for aluminum alloy plates that require coating adhesion, especially processing adhesion, which is suitable for manufacturing and for applications where strict processing such as parenthesis is performed The present invention relates to a resin-coated aluminum alloy plate for drawn and ironed cans, which is coated with a thermoplastic resin. Background art

1-DI cans (Drawn and Ironed Can) manufactured by tinning or ironing of an aluminum alloy plate are manufactured as conventional two-piece cans in which the can body and the bottom of the can are integrally formed. Have been. The DI can is tinned or drawn from an aluminum alloy plate, then cooled and lubricated with a large amount of water or a water-based lubricant using several successively arranged ironing dies and punches, and the wall thickness of the can is reduced. The original thickness

It is thinned to about 20 1 Z 3 and then degreased, washed, dried and painted. In recent years, Japanese Patent Application Laid-Open No. Hei 6-311223 discloses a method of manufacturing a two-piece can from a resin-coated metal plate by a combined working method including drawing and ironing. This method differs from the conventional DI can manufacturing method in that a resin-coated metal plate coated with a high-temperature volatile lubricant is drawn and then re-drawn in a dry manner without using water or an aqueous lubricant. I

Z5 A two-piece can with a thin can wall is manufactured by a combined machining method that involves simultaneous grinding. According to this combined processing method, the can is degreased and washed after being formed into a two-piece can, Drying and painting processes are not required, and 2-piece cans can be manufactured with almost no pollution of the environment. The present invention has been studied for the purpose of providing a resin-coated aluminum alloy sheet suitable for this combined working method. Regarding materials suitable for the composite machining method, Japanese Patent Application Laid-Open No. 7-266496 discloses materials with limited yield strength, tensile strength, plate thickness, 5 center line roughness, and the like. Examples include aluminum alloys of JIS 3004 H19. Although the use of a steel is indicated, it has the required strength, but the workability is insufficient for the purpose of the present invention.

In addition, the adhesion of the resin film coated on these aluminum alloy sheets, particularly the processing adhesion, is greatly affected by the surface condition of the aluminum alloy sheet as a base. Therefore, an aluminum alloy plate subjected to the following surface treatment for the purpose of improving the adhesion between the aluminum alloy plate and the film is used for the above-mentioned processing applications. That is,

(1) The aluminum alloy plate is subjected to a phosphoric acid or chromic acid chemical conversion treatment.

(2) When coating the aluminum alloy plate with the thermoplastic resin film, a thermosetting 5 primer is applied to one surface of the thermoplastic resin film or the aluminum alloy plate in advance.

(3) Using a solution containing chromic acid, form an anodic oxide film with a pore occupation area of 5 to 60% of micropores with a diameter of 200 Å or more and a depth of 5 m or less on the surface of the aluminum alloy plate ( JP-A-3-44496).

2.0 (4) After cleaning the aluminum alloy plate, heat it in air at a temperature of 250-650 ° C for 2 hours or more to form an oxide film with a thickness of 20 Å or more (Japanese Patent Laid-Open No. 6-272015) .

(5) After washing the aluminum alloy plate, it is subjected to an electrolytic treatment in an alkaline solution with alternating waveforms to form an acid V5 film having a thickness of 500 to 5000 angstroms and having branched micropores (JP-A-6-267638). ).

The aluminum alloy plate that has been subjected to the surface treatments (1) to (5) above is The adhesiveness of the coating on a flat plate that does not have a good surface, and the adhesiveness of the coating in applications where relatively light processing such as can lids and drawn cans are performed, are sufficiently excellent. In applications where harsh processing is performed, such as canned, drawn, stretched and then ironed, the adhesion of the coating is poor.

^ Not enough, especially in the most severely processed parts of the upper part of these cans, where the film peels off during processing or the adhesion after processing is extremely reduced. The film peels off when performing flange processing to provide a protruding edge for winding the lid or neck-in processing to reduce the diameter of the can at the top of the can, and cannot withstand severe processing.

An object of the present invention is to provide a resin-coated aluminum alloy plate suitable for a combined machining method as disclosed in Japanese Patent Application Laid-Open No. 6-31223. The composite processing method to which the present invention is directed is a processing method in which redrawing and ironing are performed simultaneously using a die having a pair of a redrawing part and an ironing part. One of the features of the combined machining method is to reduce the dimension of the shoulder radius of the die where redrawing is to be performed, and bend and bend back the material at the die shoulder corner to reduce the thickness of the can wall. Is to do. In this complex machining, severe bending and unbending are performed with a small die shoulder that is about 2 to several times the thickness of the plate to be machined, so that the surface of the material tends to be rough and cracked, and depending on the machining conditions The die wall breaks at the die shoulder radius. Also, even in the case where no break occurs at the die shoulder radius, surface roughness and surface cracking cause a decrease in adhesion between the coating resin film 0 and the aluminum alloy plate, and can wall breakage is extremely likely to occur in subsequent ironing. . The present invention relates to a resin which is resistant to can wall breakage and has a strength required for a can when performing dry / combined processing including bending / unbending and subsequent ironing at a die shoulder radius portion of a small shoulder radius. Deriving a coated aluminum alloy sheet, and even after performing the severe forming process as described above, the film after 5 "processing is coated with a thermoplastic resin on a surface-treated aluminum alloy plate with sufficient adhesion strength. To provide a thermoplastic resin-coated aluminum alloy plate And there. Disclosure of the invention

The resin-coated aluminum alloy sheet for drawn and ironed cans of the present invention is, by weight%, Mn: 0.5%, Mg: 2.2 to 4.0%, Si: ≤ 0.4%, and Fe: ≤ 0. containing 6%, and (S i + F e): . ≤0 thickness with 8% of the relationship: 0. 1 8~0.4mm, yield strength: 180~400N / mm ² of an aluminum alloy A silane coupling agent-treated film is formed on at least one surface of the plate, and both surfaces are coated with a thermoplastic resin.

(0 The resin-coated aluminum alloy sheet for drawn and ironed cans of the present invention is, in terms of% by weight, Mn: ≤ 0.5%, Mg: 2.2 to 4.0%, S i: ≤ 0.4%, as inevitable impurities. F e: containing ≤ 0. 6%, and (S i + F e): sheet thickness having a ≤ 0. 8% relationships: 0. 1 8~0.4mm, yield strength: the 180～400NZmm ² aluminum The alloy plate is characterized in that a phosphoric acid chromate-treated film is formed on at least one surface and a silane coupling agent-treated film is formed on an upper layer thereof, and then both surfaces are coated with a thermoplastic resin.

The resin-coated aluminum alloy sheet for drawn and ironed cans of the present invention is, by weight, Mn: ≤ 0.5%, Mg: 2.2 to 4.0%, Si: ≤ 0.4%, Cu: 0.05 to 0.4%, inevitable Thickness: 0.18 to 0.4 mm, yield strength: 180 to 400 NZm, containing Fe: ≤ 0.6% as a target impurity and (S i + Fe): ≤ 0.8% on at least one surface of the aluminum alloy plate of m ^2, after forming a silane coupling agent treatment film, wherein the coating the thermoplastic resin on both sides thereof.

The resin-coated aluminum alloy plate for drawn and ironed cans of the present invention is, by weight%, Mn: ≤ 0.5%, Mg: 2.2 to 4.0%, Si: ≤ 0.4%, Cu: 0.05 to 0.4%, 5 Includes Fe: ≤ 0.6% as an unavoidable impurity and (S i + Fe): ≤ 0.8% Sheet thickness: 0.18 to 0. mm, Yield strength: 180-40 ON / m on at least one surface of the aluminum alloy plate of m ^2, after forming a phosphate chromate conversion coating and silane cutlet coupling agent treated film thereon, and wherein the covering the thermoplastic resin on both sides thereof.

In the resin-coated aluminum alloy plate for a drawn and ironed can of the present invention, it is desirable that the thermoplastic resin is a thermoplastic polyester resin.

Further, in the resin-coated aluminum alloy plate for drawn and ironed cans of the present invention, it is desirable that an adhesive layer is interposed between the thermoplastic resin and the aluminum alloy plate, and that both surfaces of the aluminum alloy plate are provided. After coating the thermoplastic resin, it is preferable that a high-temperature volatile lubricant is applied to both surfaces thereof. BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is a resin which has excellent strength and workability, particularly excellent drawability and ironing workability in a dry process, and does not peel off a coated resin film even after being subjected to severe processing such as parentheses, and has excellent workability. After conducting a wide range of studies to provide coated aluminum alloy sheets, the target resin-coated aluminum alloy sheets were determined by determining the alloy composition, thickness, yield strength, type of surface treatment, and type of thermoplastic resin. Was developed. Hereinafter, the present invention will be described in detail.

First, the reasons 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, a can body material of an aluminum DI can is used in order to mix and dissolve scrap generated during the production of an aluminum alloy plate and scrap of an aluminum can after use to facilitate reuse. The alloy components of the 3004 alloy and the 5052 alloy as the cover material, especially the amounts of Mn and Mg, were considered. According to JIS standards, 3004 material has Mn: 1.0 to 1.5%, Mg: 0.8 to 1.3%, 5052 material has Mn: 0.1% or less, Mg: 2.2 to 2.2. It is specified as 8%. Resin coating of the present invention It is assumed that the Mn content of the aluminum alloy plate to be the coated substrate of the aluminum alloy plate may include the lower limit of the 3004 alloy. By doing so, it becomes possible to significantly increase the mixing ratio of the scrap of the 3004 alloy present in a large amount when the aluminum alloy used in the present invention is manufactured.

[Mn]

Mn is inexpensive and is added to provide strength.However, the upper limit of the addition amount is 1.0% of the lower limit of 3004 alloy, considering mixing and reuse of scrap from can body. The following ranges were assumed. The addition of Mn forms an A 1 _Fe—Mn-based crystallized product, but the hard α-phase, which is a transformation product thereof, is not preferred for the bending / unbending workability which is the subject of the present invention. In commercially available aluminum DI processing, A1-Fe-Mn-based crystallized substances have a lubricating effect during ironing, and are indispensable for improving ironing workability. However, in the present invention, since the aluminum alloy plate whose surface is coated with resin is processed, the lubricating action of the A1-Fe-Mn-based crystallized substance is not required, and rather the workability is impaired. That is, the crystallized product is not suitable for the composite processing method for applying the resin-coated aluminum alloy sheet of the present invention. In the combined machining method, redrawing and ironing are performed simultaneously using a die in which the redrawing part and the ironing part are integrated. However, the crystallized material significantly impairs the bending and unbending workability at the rounded portion of the die shoulder. In other words, the surface of the aluminum alloy tends to be roughened and cracked during bending and unbending, which lowers the adhesion of the coated resin film. Furthermore, depending on the amount, size, and processing conditions of the crystallized material, can wall fracture may occur. Therefore, the upper limit of the amount of Mn is set to 0.5% in consideration of the amount of Mg described later. From the viewpoint of reusing the 3004 alloy, a higher value within the above range is preferable.

[Mg]

Mg is an element that is more effective in improving the strength than Mn, and has the necessary strength as a can. It is added in order to obtain, but when the amount added is large, the processability is reduced. In the present invention, the upper limit of the amount of Mn is set to 0.5% for the above-mentioned reason, but this is not a range where the workability is sufficiently large. Therefore, the range of the Mg content is set to 2.2 to 4.0% 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 0.5% of the present invention, if Mg exceeds 4.0%, the workability becomes poor. On the other hand, if the Mg content is less than 2.2%, the strength becomes insufficient. The preferred range of the amount of Mg in the present invention is made to coincide with the specified range of the 5052 alloy in consideration of productivity of smelting and forging. The two-piece can formed by molding the resin-coated aluminum alloy plate according to the present invention using the above-described composite processing is applied to contents such as beer, carbonated beverages, and nitrogen-filled beverages, where the internal pressure of the can is positive. However, the internal pressure of the can varies depending on the contents. For this reason, a material with a large amount of Mn and Mg is used for the material for cans filled with contents with high internal pressure of the can. If the pressure strength of the can bottom is insufficient, the can bottom will buckle and become unusable as a product. The pressure resistance of the bottom of the can is mainly affected by the yield strength and thickness of the sheet. If the yield strength is low, it is necessary to increase the sheet thickness, but this will impair economic efficiency. For this reason, from the economical point of view, a high-strength material with a large amount of Mn or Mg added is suitable, but if the strength is increased by increasing the amount of Mn or Mg added, the workability of the material decreases. I do. For applications with relatively severe processing conditions, set the Mn content low and the Mg content high.

[S i]

Si causes a phase transformation in the A1-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. Is not preferred. Therefore, the upper limit is set to 0.4%.

[F e]

F e is related to Mn and forms an A 1 — F e — Mn crystallized substance. A l _F e — Mn system is preferable for the present invention from the viewpoint of bending and unbending workability as described above. Therefore, the upper limit of Fe, which is the element that forms it, is set to 0.6%. Preferably, it is 0.3% or less.

[S i + F e]

The upper limit of the amount of (S i + Fe) is also set in order to keep the amount of the A1-Fe-Mn crystallized substance, particularly the amount of the hard phase, at a low level. The upper limits of the amounts of Fe and Si are determined as described above, but if each is near the upper limit, the A1-Fe_Mn-based crystallization impairs the workability. Therefore, the upper limit is set to 0.8%, preferably 0.4% or less.

[Cu]

Cu, together with Mg, exhibits precipitation hardening due to A1-Cu_Mg-based precipitates, which is effective from the viewpoint of increasing the strength.Addition of 0.05% or more is required, but the workability decreases as the addition amount increases. Therefore, the content is preferably 0.4% or less, more preferably 0.2% or less. Addition of Zn has the effect of making the dispersion of the crystallized matter appropriate and reduces the adverse effects of the crystallized matter, so that it is preferably contained in an amount of 0.01 to 0.5%.

Next, the reasons for limiting the plate thickness and the yield strength will be described.

Both the sheet thickness and the lower limit of the yield strength are limited from the viewpoint of the can bottom pressure. Regarding the withstand pressure strength of the can bottom, the yield strength may be low when the plate thickness is large, and the plate thickness may be small when the yield strength is high. Yield strength alloy composition § Rumi, and rolling can be increased by work hardening due, processability is insufficient to exceed 400NZmm ^2. However, even when the yield strength and 4 0 ONZmm ^2, the plate thickness or more is required 0. 1 8 mm. On the other hand, when the yield strength is reduced, it is necessary to increase the thickness of the aluminum alloy sheet, which is not economical. Therefore, the lower limit of the yield strength is set to 18 ONZmm ² . In this case, if the plate thickness is 0.4 mm, sufficient pressure resistance at the bottom of the can can be obtained.

Next, the surface treatment method for an aluminum alloy sheet of the present invention will be described. First, the aluminum alloy plate is subjected to the following pretreatment including degreasing treatment, alkali treatment, and pickling. In the degreasing process, a commercially available degreasing agent is used to The oil adhering to the surface of is removed. The temperature of the treatment liquid is preferably in the range of 30 to 90 ° C, more preferably in the range of 40 to 80 ° C. As a treatment method, an aluminum alloy plate is immersed in a treatment solution, or the treatment solution is sprayed on an aluminum alloy plate. A processing time of 1 to 30 seconds is sufficient, and a range of 3 to 15 seconds is more preferable.

洗 Then wash with water and apply alkali treatment. For the alkali treatment, an aqueous solution containing one or more compounds of alkali metal or ammonium hydroxide, carbonate, bicarbonate, phosphate, silicate, and borate as main components is used. . In the alkali treatment, the oxide film formed on the surface of the aluminum alloy plate is removed. In some cases, the surface of the aluminum alloy plate may be etched. Use

10 The concentration of the aqueous alkali solution is preferably in the range of 1 to 20%, more preferably in the range of 2 to 10%. The temperature of the processing solution is preferably in the range of 30 to 80 ° C, more preferably in the range of 40 to 60 ° C. As a treatment method, a force for dipping the aluminum alloy plate in the treatment liquid or a treatment liquid is sprayed on the aluminum alloy plate. A processing time of 1 to 20 seconds is sufficient, and a range of 3 to 10 seconds is more preferable.

! 5 Then wash with water and pickle. For pickling, an aqueous solution containing one or more inorganic acids of sulfuric acid, nitric acid, hydrochloric acid, and phosphoric acid as a main component is used. The pickling is performed to remove the sumat formed on the surface of the aluminum alloy plate by the alkali treatment, but in some cases, fine holes may be formed on the surface of the aluminum alloy plate at the same time. The concentration of the aqueous solution of the acid used is preferably in the range of 1 to 10%, more preferably in the range of 1 to 5%.

10 is more preferred. The temperature of the treatment liquid is preferably in the range of room temperature to 60 ° C, more preferably in the range of room temperature to 40 ° C. As a treatment method, the aluminum alloy plate is immersed in an aqueous solution of an acid, or an aqueous solution of an acid is sprayed on the aluminum alloy plate. A processing time of 1 to 10 seconds is sufficient, and a range of 1 to 5 seconds is more preferable. This completes the preprocessing.

25 After the above pre-processing, this processing is performed. In the present invention, silane treatment using a silane coupling agent (indicated by the symbol S) is performed after phosphoric acid chromate treatment. This silane treatment (indicated by the symbol PS) is performed. First, the silane processing will be described. In the silane treatment of the present invention, a commercially available silane coupling agent is diluted with a solvent, applied to an aluminum alloy plate, and dried. Although water alone can be used as the solvent, it is preferable to use a mixed solvent of ethanol and water.

S For example, good results can be obtained by using a mixed solvent in which the mixing ratio of water and ethanol is water: ethanol = 1: 4 to 4: 1, preferably 1: 2 to 2: 1. When the mixing ratio of ethanol to water is more than 1: 4, the silane coupling agent is sufficiently uniformly dispersed in the mixed solution, but ethanol is expensive and is not advantageous in cost. On the other hand, when the mixing ratio is less than 4: 1, the silane coupling agent is not sufficiently uniformly dispersed in the mixed solution 0, and it takes a long time for drying after being applied to the aluminum alloy surface. The concentration of the silane coupling agent is preferably in the range of 0.5 to 20%, more preferably 1 to 10%, based on the mixed solution. If it is less than 0.5%, the applied state after drying tends to be uneven, and sufficient adhesion cannot be obtained. If it exceeds 20%, the effect of improving the adhesion saturates, and the cost is no longer advantageous. The temperature of the treatment liquid is preferably in the range of room temperature to 60 ° C, more preferably in the range of room temperature to 40 ° C. As a treatment method, after immersing an aluminum alloy plate in a treatment liquid, excess liquid is squeezed with a roll and then dried. An immersion time of 1 to 15 seconds is sufficient, and a range of 3 to 10 seconds is more preferable. Processing amount in the range of 0. 3~3 OmgZm ² is good Mashiku as silicon, 1: range of L OmgZm ² is more preferable.

2.0 Next, the process of performing a silane treatment after the phosphoric acid chromate treatment will be described. The phosphoric acid chromate treatment is performed using a commercially available phosphoric acid chromate treatment solution, followed by dipping or spraying. The temperature of the treatment liquid is preferably in the range of room temperature to 80 ° C, more preferably in the range of room temperature to 60 ° C. A processing time of 1 to 10 seconds is sufficient, and a range of 1 to 5 seconds is more preferable. The coating amount is preferably in the range of 3 to 5 Omg / m ² as chromium, and more preferably in the range of 5 to 3 OmgZm ² . If the coating amount is less than 3 mg / m ² as chromium, there is almost no effect on the improvement of adhesion, and 5 Omg / m ² If it exceeds, the amount of adhesion becomes large, the film becomes locally non-uniform, the adhesion decreases, and the appearance is dark brown, which is not preferable. After the phosphoric acid chromate treatment, the above silane treatment is performed.

Next, as the thermoplastic resin laminated on at least one surface of the aluminum alloy plate in the present invention, a single-layer or multi-layer resin film mainly composed of polyester resin, polyolefin resin, polyamide resin, polycarbonate resin, etc. A resin film obtained by blending two or more of these resins or a resin film obtained by copolymerization can be used. Particularly for drawn ironing cans subjected to the severe molding process of the present invention, polyethylene terephthalate, ethylene terephthalate repeating copolymer resin mainly composed of units, polybutylene terephthalate, butyl terephthalate repeating Either a polyester resin mainly composed of units, a polyester resin obtained by blending at least two types of these polyester resins, or a multilayer polyester resin obtained by laminating at least two types of the above polyester resins, and a polycarbonate resin, or It consists of a resin in which a polycarbonate resin and at least one of the above polyester resins are blended, and a multilayer resin in which a polycarbonate resin and at least two types of the above polyester resins are laminated. After forming, it is preferable to stretch in one of the vertical and horizontal directions, or in two vertical and horizontal directions, and then heat-fix to form an oriented resin film, which is then laminated on a metal plate. Alternatively, the above resin may be heated and melted, extruded directly onto a metal plate, and laminated.

The thickness of the laminated resin film is preferably in the range of 5 to 50 / im, more preferably in the range of 10 to 30m. When the thickness is 5 zm or less, it is difficult to continuously laminate the metal plate at high speed. On the other hand, if the thickness of the resin film to be laminated is 50 or more, it is not preferable in terms of economic efficiency as compared with epoxy resin paints and the like which are widely used as materials for cans.

Also, the thermoplastic resin film may be directly laminated on an aluminum alloy plate. Alternatively, they may be laminated by interposing a thermosetting adhesive such as an epoxy-phenol resin between a resin film and an aluminum alloy plate. The resin film is laminated 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. be able to.

The resin-coated aluminum alloy plate of the present invention is obtained by laminating the above-mentioned thermoplastic resin film on the aluminum alloy plate subjected to the above-mentioned surface treatment. Stacking is performed as follows. That is, the surface-treated aluminum alloy sheet continuously fed from the aluminum alloy sheet supply means is heated to a temperature equal to or higher than the melting point of the thermoplastic resin film by using a heating means, and is sent from the film supply means to both surfaces thereof. The discharged thermoplastic resin film is brought into contact, superimposed between a pair of laminating ports, sandwiched and pressed, and immediately cooled immediately.

Finally, a high-temperature volatile lubricant is applied to the upper surface of the thermoplastic resin film laminated as described above. It is desirable that the high-temperature volatile lubricant be scattered by 50% or more when heated for several minutes at a temperature of about 200 ° C after drawing and ironing. Specifically, liquid paraffin, synthetic paraffin, natural It is selected according to the processing conditions and the heating conditions after processing from a simple substance such as wax or a mixture of these. As the properties 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. The amount of application should be determined in consideration of the outer surface of the can, the inner surface of the can, processing conditions, heating conditions after processing, etc., but it is 5 to 100 mg Zm ² , preferably 3 to 100 mg Zm ² . A range of 0-6 O mg Zm ² is suitable. As described above, the alloy composition, plate thickness, yield strength, type of surface treatment, and characteristics of thermoplastic resin, etc. of the aluminum alloy plate are limited, and a high-temperature volatile lubricant is applied on the laminated thermoplastic resin. By doing so, a thermoplastic resin-coated aluminum alloy sheet suitable for forming a can having a thin can wall by drawing and ironing can be obtained. (Example) Alloys having the compositions shown in Tables 1 and 2 were melted, fabricated, and surface-polished by a conventional method, subjected to a homogenizing heat treatment at 550 ° C, and then hot-rolled and then cold-rolled to various thicknesses. Next, continuous annealing was performed by heating at 520 ° C for 10 seconds, and then cold-rolled again to obtain sheet thicknesses of 0.16 mm, 0.18 mm, 0.25 mm, 0.40 mm, and 0.45 mm. Pretreatments of degreasing, alkali treatment and pickling were performed under the conditions shown. After that, surface treatment was performed under the conditions shown in Table 3.

[Preprocessing conditions]

• Degreasing treatment

The aluminum alloy plate is immersed in a 3% by weight aqueous solution of a commercially available degreasing agent (Safe Cleaner 322N-8 (manufactured by Nippon Paint Co., Ltd.)) heated to 80 ° C for 15 seconds, and then washed with water. Then it was dried.

• Alkali treatment

The degreased aluminum alloy plate was immersed in a 5% aqueous sodium hydroxide solution heated to 50 ° C. for 10 seconds, washed with water, and dried.

· Pickling

The aluminum alloy plate subjected to the alkali treatment was immersed in 1% sulfuric acid at room temperature for 3 seconds, washed with water and dried.

A surface-treated aluminum alloy sheet shown in Table 3 was heated to 240 ° C, and a 20 / im copolyester resin consisting of 12% by mole of polyethylene isophthalate and 88% by mole of polyethylene terephthalate on both sides. The biaxially oriented film was abutted, the film and an aluminum alloy plate were sandwiched and laminated by a pair of rolls, immediately immersed in water and quenched. After drying, about S OmgZm ^{2 was} applied to both sides of the grammar wax (boiling point: 115 ° C) to obtain a test plate. The test plate was evaluated for the strength after bending and unbending, the workability by composite processing, the pressure resistance, and the adhesion between the coated resin film and the surface of the aluminum alloy plate after processing. The strength after bending and unbending is determined by adding the tensile strength of the test plate subjected to bending and unbending at a bending radius of 0.5 mm. When the yield strength of the test plate before the test was 30% or more, it was evaluated as 〇 (good), and when it was less than 30%, as X (defective). The evaluation of the composite workability was performed on aluminum alloy sheets having a plate pressure of 0.25 mm, 0.30 mm, 0.40 mm, 0.45 mm as shown below. A 100 mm-diameter drawn can formed at a drawing ratio of 1.6 was processed into a primary redrawn can with a diameter of 75 mm and a can wall thickness of 80% of the original plate thickness, and the subsequent redrawability was evaluated. For secondary redrawing, the redrawing ratio is 1.15, the redrawing die radius is 0.4 mm, and the workability at the die shoulder and ironing part is changed by changing the clearance of the ironing die. The evaluation was made based on the presence or absence of can wall rupture. The case where there was no can wall rupture was evaluated as 〇 (good), and the case where can wall rupture occurred was evaluated as X (bad). The pressure resistance strength was evaluated by forming a resin-coated aluminum alloy sheet into a can with a diameter of 65 mm by ordinary drawing, doming the bottom of the can, applying internal pressure, and then buckling the can bottom. where seat屈圧force of 3 kgf Roh cm ² or more 6. 〇 (good), 6. less than 3 kgf / cm ² was x (bad).

The processing adhesion of the thermoplastic resin film was evaluated as follows. A strip-shaped specimen having a width in the circumferential direction of the can of 15 mm and a length in the height direction of the can of 50 mm was cut out from the drawn and ironed can covered with the polyester film obtained as described above. The entire aluminum alloy is cut from the inner side of the can and the outer side of the can at the can height of 110 mm (Tf: upper end of the can) of this strip-shaped specimen, but the film on the opposite side is cut. A cut was made that did not reach, and a sample was prepared in which only one side of the film was left uncut. These samples were bent at 180 ° at the cuts, and the film was forcibly peeled at about 5-7 mm from the cuts at one of the bent parts. One end of the sample obtained in this way and the other end where the film was forcibly peeled off were clamped between the upper and lower chucks of Tensilon, and the tensile measurement was performed with Tensilon. Then, the tensile strength at which the film coated on the aluminum alloy plate and the remaining film began to peel from the aluminum alloy plate was measured, and the result was defined as the peel strength. The case where the peel strength was 0.30 kgf or more was evaluated as (good), and the case where the peel strength was less than 0.30 kgf was evaluated as X (defective). Tables 4 and 5 summarize the above evaluation results. Alloy composition and mechanical properties of test plate (1)

□ Gold composition (% by weight) Adhesive Thickness Yield strength Degree of use

(Mn Mg Si Cu Fe Al treatment right image)

Natural (N / band ² )

0.49 4.07 0.22 0.23 0.23 Remaining S 0.16 350

0.43 2.51 0.25 0.24 0.22 Remaining S 0.18 320

0.79 2.55 0.27 0.27 0.29 Remaining S 0.25 330

0.45 2.49 0.23 0.25 0.24 Remaining S 0.25 310

0.46 2.50 0.21 0.36 0.25 Remaining S 0.25 310

0.44 2.51 0.22 0.47 0.23 Remaining S 0.25 310

0.44 2.48 0.46 0.25 0.22 S 0.25 310

0.46 2.53 0.25 0.23 0.61 Remaining S 0.25 310

0.49 2.51 0.27 0.25 0.33 Remaining S 0.25 310 Table 2 Alloy composition and mechanical properties of the test plate (2)

(Note) ^# : Epoxy adhesive 3 Surface treatment of aluminum alloy plate

(Note) *: Made by Shin-Etsu Chemical Co., Ltd. +: Solvent Water / Ethanol = 2 $ $: Made by Nippon Paint Co., Ltd.

4 Result of characteristic evaluation of test plate (1)

(Note) I: Not evaluated 5 Result of characteristic evaluation of test plate (2)

(Note) I: Not evaluated

Industrial applicability

The resin-coated aluminum alloy plate for drawn and ironed cans according to the present invention is characterized in that the can wall breakage occurs when performing the combined processing including the bending / returning process at the die shoulder radius portion of the target small shoulder radius and the subsequent ironing process in a dry manner. It is difficult to produce, and it is possible to obtain a drawn and ironed can having the required strength as a can, and it has excellent processing adhesion of the resin film, and the resin film peels off even when subjected to severe processing such as drawing and ironing There is nothing. Further, by containing the Mn content of the aluminum alloy plate serving as the coated substrate of the resin-coated aluminum alloy plate of the present invention up to the lower limit of Mn amount of the 304 alloy, the aluminum alloy used in the present invention can be obtained. In manufacturing, the mixing ratio of scrap of a large amount of 304 alloy can be remarkably increased, so that it is excellent in recyclability.

Claims

The scope of the claims

1. In weight%, Mn: ≤0.5%, Mg: 2.2 ~ 4.0%, S i: ≤0.4%, Fe: ≤0.6% as inevitable impurities, and ( S i + F e): ≤0.8%

Thickness having 5 relationship: 0. 18～0.4Mm, yield strength: 180 to 400 on at least one surface of NZmm ² of the aluminum alloy plate, after form form the silane cutlet coupling agent treated film, thermoplastic resin on both surfaces Resin-coated aluminum alloy plate for drawing and ironing cans coated with

2. In% by weight, Mn: ≤0.5%, Mg: 2.2 ~ 4.0%, S i: ≤ 0.4%, | 0 Contains Fe: ≤ 0.6% as inevitable impurities, And (S i + F e): ≤0.8%, thickness: 0.18 ~ 0.4mm, yield strength: 180 ~ 40 ON / mm ^{2 At} least one side of aluminum alloy plate, phosphoric acid chromate A resin-coated aluminum alloy plate for drawing and ironing cans, which is formed by forming a treated film and a silane coupling agent-treated film on the upper layer, and coating both surfaces with a thermoplastic resin.

I 3. By weight%, Mn: ≤ 0.5%, Mg: 2.2 ~ 4.0%, S i: ≤ 0.4%, Cu: 0.05 ~ 0.4%, Fe: ≤ as inevitable impurities 0. containing 6%, and (S i + F e): . ≤0 thickness with 8% of the relationship: 0. 18 to .4 mm, the yield strength of: 180~400N // mm ² of an aluminum alloy After forming a silane coupling agent-treated film on at least one surface of the plate, do not coat both surfaces with a thermoplastic resin.

2 Resin-coated aluminum alloy plate for drawing and ironing cans.

4. By weight%, Mn: ≤0.5%, Mg: 2.2 ~ 4.0%, S i: ≤0.4%, Cu: 0.05 ~ 0.4%, F e: ≤0 as inevitable impurities . containing 6%, and (S i + F e): sheet thickness having a ≤ 0. 8% relationships: 0. 18～0.4Mm, yield strength index: 180~400N / mm ² of the aluminum alloy plate Phosphorus on at least one side

After forming a 2S acid chromate-treated film and a silane coupling agent-treated film on its upper layer, a resin-coated aluminum Aluminum alloy plate.

5. The resin-coated aluminum alloy plate for a drawn and ironed can according to any one of claims 1 to 4, wherein the thermoplastic resin is a thermoplastic polyester resin.

6. The resin-coated aluminum alloy plate for a drawn and ironed can according to any one of claims 1 to 5, wherein an adhesive layer is interposed between the thermoplastic resin and the aluminum alloy plate.

7. The aluminum alloy plate is coated with the thermoplastic resin on both surfaces thereof, and then a high-temperature volatile lubricant is applied to both surfaces thereof. The resin-coated aluminum alloy plate for the drawn ironing can described.