WO1998049358A1 - Resin-coated aluminum alloy sheet for drawn and ironed cans - Google Patents

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 sheet for drawn and ironed cans Technical field

 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 that has been subjected to surface treatment suitable for aluminum alloy sheets that require coating adhesion, especially processing adhesion, which is suitable for manufacturing and for applications where severe processing such as parentheses is performed. The present invention relates to a resin-coated aluminum alloy plate for a drawn and ironed can, which is obtained by coating a thermoplastic resin on a aluminum alloy plate. Background art

DI cans (Drawn and Ironed Can), which are obtained by drawing and ironing a tinplate or aluminum alloy plate, have been conventionally manufactured as two-piece cans in which the can body and the bottom of the can are integrally formed. I have. The DI can is tinned or drawn from an aluminum alloy plate, then cooled and lubricated with a large amount of water or water-based lubricant using several successively arranged ironing dies and punches, and the wall thickness of the can is reduced. Is reduced to the original thickness of about 1 Z3, 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 method for manufacturing DI cans 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. 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. Hei 7-2666496 discloses materials with limited yield strength, tensile strength, plate thickness, center line roughness, and the like. Although the use of an aluminum alloy of 0.4 H 19 is indicated, the workability is insufficient for the purpose of the present invention, although it has the required strength.

 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. For this reason, aluminum alloy sheets that have been subjected to the following surface treatments for the purpose of improving the adhesion between the aluminum alloy sheet and the film are 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, apply a thermosetting primer 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 on the surface of the aluminum alloy plate with pores occupying 5 to 60% of pores with a diameter of 200 angstroms or more and a depth of 5 microns or less. (See Japanese Patent Application Laid-Open No. 3-44469).

 (4) After cleaning the aluminum alloy plate, heat it in air at a temperature range of 250-650 ° C for 2 hours or more to form an oxide film with a thickness of 20 Å or more. Kaihei 6—2 7 210 5).

 (5) After washing the aluminum alloy plate, it is subjected to electrolytic treatment with an alternating waveform in an alkaline solution to form an oxide film having a thickness of 500 to 500 Å and having branched micropores ( Japanese Patent Application Laid-Open No. 6-2667338).

The aluminum alloy plate subjected to the surface treatment of (1) to (5) above is processed 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 severe processing is applied, such as canned steel, drawn steel, stretched and then ironed, the adhesion of the film is not sufficient. In the area where processing is performed, the coating peels off during processing or the adhesion after processing is extremely reduced, and flange processing is performed to provide an overhanging edge for winding the can lid on the can in the next process Also, when performing neck-in processing to reduce the diameter of the can at the upper end of the can, the coating peels off and cannot withstand severe processing.

An object of the present invention is to provide a resin-coated aluminum alloy sheet 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 performed, and to bend and re-bend the material at the die shoulder area to reduce the thickness of the can wall In this complex machining, severe bending and unbending are performed with a small die shoulder that is about two to several times the thickness of the plate to be machined, so that the surface of the material is likely to be rough and cracked. Depending on the processing conditions, the can wall breaks at the die shoulder radius. Even in the case where no fracture occurs at the die shoulder radius, the roughened surface and surface cracks cause a decrease in adhesion between the coated resin film and the aluminum alloy plate, and can wall fracture is extremely likely to occur in subsequent ironing. The present invention relates to a resin which is capable of hardly breaking a can wall and performing a required strength as a can when performing a bending / bending 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. Introduces coated aluminum alloy sheet, and even after severe processing as described above, the film after processing is made by coating a surface-treated aluminum alloy sheet with sufficient adhesion strength with a thermoplastic resin To provide an aluminum alloy sheet coated with a thermoplastic resin I quit. Disclosure of the invention

The resin-coated aluminum alloy sheet for drawn and ironed cans of the present invention is, in terms of% by weight, Mn: 0.5 to 1.6%, Mg: 0.2 to 2.0%, Si: ≤0.4% ヽ Fe: ≤ unavoidable impurity Containing 0.6% and having a relationship of (S i + Fe): ≤ 0.8% Sheet thickness: 0.18 to 0.4 mm, Yield strength: 180 to 400 NZm m ² Aluminum alloy At least one side of the plate, silane coupling It is characterized in that both surfaces are coated with a thermoplastic resin after forming a coating with a coating agent.

In addition, the resin-coated aluminum alloy sheet for drawn and ironed cans of the present invention is expressed in terms of% by weight: Mn: 0.5 to 1.6%, Mg: 0.2 to 2.0%, Si: ≤0.4%, and Fe: unavoidable impurities. ≤ containing 0.6%, and (S i + F e): sheet thickness to have a ≤ 0.8% relationships: 0.18～0.4Mm, yield strength: at least one side of 180~400N // mm ² aluminum Niumu alloy plate In addition, after forming a phosphoric acid chromate treated film and a silane-based printing agent treated film on the upper layer, a thermoplastic resin is coated on both surfaces thereof.

The resin-coated aluminum alloy sheet for drawn and ironed cans of the present invention is, by weight%, Mn: 0.5 to 1.6%, Mg: 0.2 to 2.0%, Si: 0.05 to 0.4%, Cu: 0.05 to 0.4%, unavoidable impurities as F e: ≤ containing 0.6% and (S i + F e): sheet thickness having ≤ 0.8% relationships: 0.18～0.4Mm, yield strength: 180~40 ONZmm ² aluminum It is characterized in that a silane-based printing agent-treated film is formed on at least one surface of an alloy plate, 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, in terms of% by weight, Mn: 0.5 to 1.6%, Mg: 0.2 to 2.0%, Si: 0.05 to 0.4%, Cu: 0.05 to 0.4%. , Includes Fe: ≤ 0.6% as inevitable impurities, and has a relationship of (Si + Fe): ≤ 0.8%. Thickness: 0.18-0.4 mm, Yield strength: 180-4 On at least one surface of the 0 0 N / mm ² of the aluminum alloy plate, and characterized in that after forming the Shirankatsupuri ing agent treated film in phosphate chromate treatment coating and the upper layer covers the thermoplastic resin on both surfaces I do.

 In the resin-coated aluminum alloy plate for a drawn and ironed can of the present invention, it is preferable that the thermoplastic resin is a thermoplastic polyester resin, and an adhesive layer is interposed between the thermoplastic resin and the aluminum alloy plate. It is desirable to make it. After the thermoplastic resin is coated on both surfaces of the aluminum alloy plate, it is preferable that a high-temperature volatile lubricant is applied to both surfaces. 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 with reference to examples.

 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. Each alloy component is shown by weight%.

[M n]

Mn is added because strength can be obtained at low cost. If it is less than 0.5%, the effect is insufficient. On the other hand, if it exceeds 1.6%, the amount of A1-Fe-Mn-based crystallized substances increases, and the bending / unbending workability, which is the subject of the present invention, is significantly impaired. In DI processing, which is widely industrially produced, 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 an aluminum alloy plate whose surface is coated with a resin is processed, A 1 — F The lubrication of e-Mn-based crystals is not required, but rather impairs workability. That is, the crystallized product is not suitable for the combined working 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 with a pair of redrawing and ironing parts, and the shoulder radius of the redrawing die is a small shoulder radius that is several times the sheet thickness or less. However, the crystallized material significantly impairs the bending and unbending workability at the rounded portion of the die shoulder. In other words, during bending and unbending, the surface of the aluminum alloy is easily roughened and cracked, which lowers the adhesion of the coated resin film. Furthermore, depending on the amount, size, and processing conditions of the crystallization, the can wall may be broken. As described above, unlike the case of DI processing, the A 1 —F e —M n system crystallized substance is not preferable for the present invention, and it is desirable to minimize the amount.

[M g]

 Mg is an element that is more effective than Mn in improving strength. Add 0.2% or more to obtain the strength required for the can, mainly the pressure resistance at the bottom of the can. Mg is an expensive element, and as the amount of addition increases, the formability deteriorates. Therefore, the upper limit is 2% from the viewpoints of formability and economy. The two-piece can formed by molding the resin-coated aluminum alloy plate according to the present invention by using the above-described composite heating is applied to contents such as beer, carbonated drinks, and nitrogen-filled drinks, where the internal pressure of the can is positive. If the bottom strength is insufficient, the can bottom will buckle and become unusable as a product. The bottom strength 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, which impairs economic efficiency.

 [S i]

Si causes a phase transformation in the A1-Fe-Mn system crystallized material to form a so-called hard 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, it is bent and bent back more than the crystallized material before the phase transformation. It is not preferable because it lowers the properties. Therefore, the upper limit in terms of workability To 0.4%. However, if it is necessary to limit the lower limit in terms of increasing strength, the lower limit is 0.05%.

CF e]

 F e is related to Mn, and forms an A 1 — F e — M n crystallized product. The A 1 —F e —Mn system is not preferable for the present invention from the viewpoint of bendability and unbendability, as described above, and the upper limit of Fe, which is an element forming 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 A 1-Fe-Mn-based crystallization, especially the amount of hard phase, at a low level. Although the upper limits of the amounts of Fe and Si are determined as described above, if each is near the upper limit, the A 1 —Fe—Mn crystallized material impairs the workability. Therefore, the upper limit is set to 0.8%, preferably 0.4% or less.

[C u]

 Cu shows precipitation hardening due to A1-Cu-Mg based precipitates together with Mg, and is effective from the viewpoint of increasing the strength.Addition of 0.05% or more is required. Is preferably 0.4% or less, and more preferably 0.2% or less. Addition of Zn has an effect of appropriately dispersing crystallized substances, and is preferably contained in an amount of 0.01 to 0.5% in order to reduce adverse effects of the crystallized substances.

 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 pressure resistance of the bottom of the can, 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 can be enhanced by aluminum alloy composition and work hardening by rolling, etc., but when it exceeds 40 ON / mm ² , workability becomes insufficient. However, even when the yield strength is 400 N / mm ² , the thickness must be 0.18 mm or more. On the other hand, when the yield strength is lowered, it is necessary to increase the thickness of the aluminum alloy sheet, Not a target. Therefore, the lower limit of the yield strength is set to 18 ON / mm ² . In this case, if the sheet thickness is 0.4 mm, sufficient pressure resistance of the can bottom 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 treatment, oil adhering to the surface of the aluminum alloy plate is removed using a commercially available degreasing agent. 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, the aluminum alloy plate is immersed in the treatment solution, or the treatment solution is sprayed on the aluminum alloy plate. A processing time of 1 to 30 seconds is sufficient, and a range of 3 to 15 seconds is more preferable.

 Then, it is washed with water and treated with alkali. Alkali treatment is an aqueous solution containing one or more compounds of hydroxides, carbonates, bicarbonates, phosphates, silicates and borates of alkali metals or ammonium. Is used. In the heat 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. The concentration of the aqueous alkali solution used 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 immersing the aluminum alloy plate in the treatment liquid, or spraying the treatment liquid 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.

Then, it is washed with water and pickled. For pickling, an aqueous solution mainly containing one or more of sulfuric acid, nitric acid, hydrochloric acid and phosphoric acid is used. The pickling is performed to remove the smear formed on the surface of the aluminum alloy plate by the hot-rolling process, 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%. 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, an aluminum alloy plate is Immerse in the solution or spray an aqueous solution of acid 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.

After performing the above pre-processing, this processing is performed. In the present invention, either a silane treatment using a silane coupling agent (indicated by symbol S) or a further silane treatment after the phosphoric acid chromate treatment (indicated by 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. 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 the ethanol is expensive and is not cost-effective. On the other hand, when the mixing ratio is less than 4: 1, the silane coupling agent does not disperse sufficiently uniformly in the mixed solution, and it takes a long time to dry 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 in the range of 1 to 10%, based on the mixed solution. If it is less than 0.5%, the coating state after drying tends to be uneven, and sufficient adhesion cannot be obtained. If it exceeds 20%, the effect of improving the adhesion will be saturated and the cost will not be advantageous. The temperature of the processing liquid is preferably in the range of room temperature to 6 (TC, more preferably in the range of room temperature to 40 ° C. As a processing method, after immersing the aluminum alloy plate in the processing liquid, the excess liquid is squeezed with a roll. , then dried. immersion time is sufficient 1 to 1 5 seconds, 3 to 1 0 0 seconds range is more preferable. amount of processing silicon. 3 to 3 0 mg Z range of m ² is good Mashiku , more preferably in the range of 1~1 O mg Z m ^2.

Next, a description will be given of a treatment in which a silane treatment is performed after the phosphoric acid chromate treatment. For phosphoric acid chromate treatment, use a commercially available phosphoric acid chromate treatment solution. Perform immersion or spray treatment. 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 SS Omg gZm ² . If the coating weight is less than 3 m gZm ² as chromium almost no effect in improving the adhesion, as 50m gZm ² many be locally coating adhesion amount exceeds decreases the adhesion becomes uneven The appearance is dark brown, which is not desirable. After the phosphoric acid chromate treatment, the above-mentioned silane treatment is performed.

 Next, in the present invention, as the thermoplastic resin laminated on at least one side of the aluminum alloy plate, a single-layer or multi-layer resin mainly composed of polyester resin, polyolefin resin, polyamide resin, polycarbonate resin and the like is used. A film, a resin film obtained by blending two or more of these resins, or a resin film obtained by copolymerization can be used. In particular, for drawn ironing cans subjected to the severe forming process of the present invention, polyethylene terephthalate, copolymerized polyester resin mainly composed of ethylene terephthalate repeating units, polybutylene terephthalate, butylene terephthalate repeating units Or a polyester resin blended with 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 further a polycarbonate resin or a polycarbonate resin It consists of a resin obtained by blending at least one kind of resin and the above-mentioned polyester resin, and a multilayer resin obtained by laminating at least two kinds of polycarbonate resin and the above-mentioned polyester resin. After molding, the aspect either direction, or extend in vertical and horizontal two directions, and then after the orientation resin film produced by heat, it is preferable to laminate the 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 / wm, The range of m is more preferred. If the thickness is 5 m or less, it is difficult to continuously laminate the metal plate at a high speed. On the other hand, if the thickness of the laminated resin film is 50 m or more, it is not preferable in terms of economic efficiency as compared with epoxy resin paints widely used as materials for cans.

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

 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, superposed between a pair of laminating rolls, 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 It is selected from simple substances such as natural wax, or a mixture thereof, depending on the processing conditions and the heating conditions after processing. As the properties of the lubricant to be applied, those having a melting point of 25 to 8 CTC and a boiling point of 180 to 400 ° C. are desirable for achieving the object of the present invention. 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, etc., but 5 to 100 mg / m, preferably 30 to 100 mg / m. A range of ~ 6 O mg Z m 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 55 CTC, and then hot-rolled and then cold-rolled to various thicknesses. Next, continuous annealing by heating at 520 ° C for 10 seconds was performed, and then cold rolling was performed again, followed by a stabilization treatment, to obtain 0.16 mm, 0.18 mm, 0.25 mm, 0.40 mm, and 0.45 mm. The plate was made thick, and both surfaces were subjected to pretreatments such as degreasing, alkali treatment and pickling under the following conditions. Thereafter, surface treatment was performed under the conditions shown in Table 3.

[Preprocessing conditions]

 -Degreasing

 After immersing the aluminum alloy plate for 15 seconds in a 3% by weight aqueous solution of a commercially available degreasing agent (Safe Cleaner 1322N-8 (manufactured by Nippon Paint Co., Ltd.)) heated to 80 ° C, Washed with water and dried.

 -Al power 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 in 1% sulfuric acid at room temperature was immersed for 3 seconds, washed with water and dried.

The surface-treated aluminum alloy plate shown in Table 3 was heated to 24 CTC, and a biaxially stretched copolyester consisting of 88 mol% of polyethylene terephthalate and 12 mol% of polyethylene isophthalate was heat-fixed on both sides. (The surface that becomes the inner surface of the can after molding into a can described later: thickness 25; «m, the surface that becomes the outer surface of the can: The thickness was 15〃m) simultaneously, the film and the aluminum alloy plate were sandwiched and laminated by a pair of rolls, immediately immersed in water, quenched, and dried. Then, grammar wax (boiling point: 115 ° C) was applied to both sides thereof at about 5 O mg / m ² 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 when the tensile strength of the test plate subjected to bending and unbending at a bending radius of 0.5 mm is 30% or more of the yield strength of the test plate before processing.

(Good) and less than 30% were rated as X (Poor). The evaluation of composite workability was performed on test pieces of aluminum alloy sheets having a thickness of 0.25 mm, 0.40 mm, and 0.5 mm as shown below. A drawn can with a diameter of 10 O mm 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 secondary redrawability was evaluated. . In the secondary redrawing process, the redrawing ratio is 1.15, the redrawing die shoulder is 0.4 mm, and the clearance of the ironing die is changed to improve the workability at the die shoulder and ironing part. Evaluation was made based on the presence or absence of can wall rupture during processing. A case where there was no can wall rupture was evaluated as 〇 (good), and a case where can wall rupture occurred was evaluated as X (poor). Withstand pressure strength was evaluated by forming a resin-coated aluminum alloy plate into a can with a diameter of 65 mm by ordinary drawing, doming the bottom of the can, applying internal pressure, and buckling the can bottom. where seat屈圧force of 6.3 kgf Z cm ² or more 〇 (good), the case of less than 6.3 kgf Z cm ² was X (poor).

 The processing adhesion of the thermoplastic resin film was evaluated as follows. From the drawn and ironed can covered with polyester film obtained as described above, the circumferential width of the can is 1

A 5 mm long, 50 mm long can-shaped strip was cut out. The entire aluminum alloy is cut from the inner surface of the can and the outer surface of the can at the can height of 110 mm (Tf: upper end of the can) of this strip-shaped specimen, but reaches the film on the opposite side. A cut was made, and a sample was prepared in which only one side of the film was left uncut. These samples were bent at 180 degrees at the cuts, and one of the bent parts In, the film was forcibly peeled off at a portion about 5 to 7 mm from the cut. 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, and the forcible peeling was not performed. At the same time, 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 defined as the peel strength. A case where the peel strength was 0.30 kgf or more was defined as (good), and a case where the peel strength was less than 0.3 kgf was defined as X (bad).

Tables 4 and 5 summarize the above evaluation results.

Table 1 Alloy composition and mechanical properties of test plate (1) Gold composition (% by weight) Surface adhesive Plate thickness Yield strength treatment

Mn Mg Si Cu Fe Al Presence (mm) (N / mm ² )

1.41 2.20 0.19 0.23 0.21 Remaining S Ant. 0.16 350

1.37 1.68 0.20 0.25 0.22 Remaining S 0.18 335

1.73 1.67 0.19 0.24 0.18 Remaining S Ant. 0.25 345

1.34 1.90 0.18 0.26 0.19 Remaining S m 0.25 340

1.35 1.89 0.20 0.36 0.20 Remaining S 0.25 340

1.36 1.88 0.16 0.47 0.18 Remaining S 0.25 340

1.36 1.69 0.45 0.25 0.27 S 0.25 335

1.35 1.68 0.19 0.23 0.64 S Απΐ. 0.25 335

1.39 1.75 0.20 0.27 0.30 Remaining S 0.25 340 Table 2 Alloy composition and mechanical properties of the test plate (2

(Note) ^# : Epoxy adhesive is used Table 3 Surface treatment of aluminum alloy sheet

Nippon Paint Co., Ltd.

Table 4 Results of property evaluation of test plate (1) Material Bending / bending Composite workability Compressive strength Working adhesion Category N0 Return strength

1 X ― 1 ― Comparative example

2 〇 ― ― Example of implementation

3 X X ― ― Comparative example

4 〇 〇 〇 〇 Example

5 〇 〇 〇 〇 Example

6 X X ― Comparative example

7 X X ― ― Comparative example

8 XX Comparative example

9 〇 〇 〇 〇 Example

(Note) I: Not evaluated Table 5 Characteristic evaluation results of test plates (2

(Note) I: Not evaluated Industrial applicability

The resin-coated aluminum alloy sheet for drawn and ironed cans according to the present invention is characterized in that the can wall breaks when dry bending is performed in the composite processing including bending, bending back, and subsequent ironing at the die shoulder radius portion of the target small shoulder radius. It is hard to occur, and it is possible to obtain a drawn and ironed can having the required strength as a can and has excellent processing adhesion of the resin film. The resin film does not peel off even under severe processing such as drawing and ironing.

Claims

The scope of the claims 1. In% by weight, Mn: 0.5 to 1.6%, Mg: 0.2 to 2.0%, Si: ≤ 0.4%, Fe: ≤0.6% as unavoidable impurities, and (Si + Fe) ): sheet thickness having a ≤ ς · 0.8% relationship: .18-.4 mm, yield strength: at least one side of 180 to 400 N / mm ² of the aluminum alloy plate, after forming the Shirankappuri ring agent treatment film, A resin-coated aluminum alloy plate for drawing and ironing cans with both surfaces coated with a thermoplastic resin. 2. In weight%, Mn: 0.5 to 1.6%, Mg: 0.2 to 2.0%, Si: ≤ 0.04%, Fe: ≤ 0.6% as an unavoidable impurity, and (Si + F e): ≤ 0.8%, thickness: 0.18 to 0.4 mm, yield strength: 180 to 400 N / mm ^{2 At} least one side of the aluminum alloy plate, the phosphoric acid chromate treated film and the upper layer A resin-coated aluminum alloy plate for squeezing and ironing cans with a thermoplastic resin coating on both surfaces after forming a coating with a coating agent. 5 3. By weight%, Mn: 0.5-1.6%, Mg: 0.2-2.0%, Si: 0.05-0.4%, Cu: 0.05-0.4%, Fe: ≤0.6% as inevitable impurities And (S i + F e): ≤ 0.8%, thickness: 0.18 to 0.4 mm, yield strength: 180 to 400 N / mm ^{2 At} least one surface of an aluminum alloy plate, a silane coupling agent-treated film After forming, a resin-coated aluminum alloy plate for drawing and ironing cans coated on both sides with thermoplastic resin Z0. 4. By weight%, Mn: 0.5-1.6%, Mg: 0.2-2.0%, Si: 0.05-0.4%, Cu: 0.05-0.4%, Fe: ≤0.6% as inevitable impurities And (S i + Fe): ≤ 0.8%, thickness: 0.18 to 0.4 mm, yield strength: 180 to 40 ON / mm ^{2 At} least 5 sides of aluminum alloy plate, phosphoric acid chromate After forming a silane coupling agent-treated film on the treated film and its upper layer, a resin for squeezing and ironing cans with both surfaces coated with a thermoplastic resin Coated 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 method according to any one of claims 1 to 6, wherein the thermoplastic resin is coated on both surfaces of the aluminum alloy plate, and a high-temperature volatile lubricant is applied to both surfaces. The resin-coated aluminum alloy plate for the drawn ironing can described.