JP3046217B2 - Resin-coated aluminum plate for dry drawing and ironing can - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for a two-piece can manufactured by processing including ironing. Specifically, a two-piece can with a thin can wall is manufactured by processing including ironing without cooling or lubricating with water or a water-based lubricant or the like, and without requiring cleaning of the can after can-making. The present invention relates to a thermoplastic resin-coated aluminum plate and a thermoplastic resin-coated aluminum alloy plate that are suitable for use.

[0002]

2. Description of the Related Art Conventionally, a cane body and a can bottom have been integrated into one piece.
DRD made of tinplate, aluminum plate, aluminum alloy plate, electrolytic chromic acid treated steel plate, etc.
Cans (Drawn and Reddraw Can),
DI can (Drawn and Ironed can)
However, in recent years, DTR cans (Draw-Thin
/ Redraw Can) has also been put to practical use. DRD
Since the can is manufactured by drawing and redrawing, the thickness of the can wall increases in proportion to the height of the can. Therefore, from the viewpoint of economy, it is generally applied to cans having a low can height, and as a base metal plate, an electrolytic chromic acid-treated steel plate, tinplate, and an aluminum alloy plate are used. On the other hand, DI cans that are manufactured by drawing and ironing after drawing can be economically applied to cans with a high can height because the wall thickness of the can can be reduced to about 1/3 of the original plate thickness. In this case, an aluminum alloy plate is used. Further, the DRD can and the DI can are different in that the metal plate previously coated with the organic film is drawn in the case of the DRD can, whereas the DI can is painted after ironing. This is because the degree of processing and the stress state during processing are greatly different between DRD processing and DI processing. When the metal sheet coated with an organic film is applied to DI processing, which is a processing with extremely high processing degree and surface pressure on the can wall, it is practically used due to seizure of the organic film on the mold and damage to the organic film on the inner and outer surfaces. It has not been converted. On the other hand, DTR cans are manufactured by making the shoulder radius of the dies at the time of redrawing small, performing bending and unbending at the shoulders while applying a large tensile force, and thinning the can wall. . DTR
In the case of a can, it is a process very similar to drawing, but since the can wall is stretched, the can wall is slightly thinner than the original plate thickness. Also, like ironing,
Since a large surface pressure is not applied to the can wall between the die and the punch, the load on the organic film is not so large, and the organic film is hardly damaged. A chromic acid-treated steel sheet coated with a thermoplastic resin is industrially used. However, in the case of DTR cans, since the process is mainly performed by tensile force, the can wall is easily broken during processing, and the can wall thickness is about 80% of the original plate thickness, which is larger than the DI can. ing. Here, the reason that an aluminum alloy plate has not been put to practical use as a base metal plate is that it is not as suitable as a method of electrolytic chromic acid-treated steel plate for a method of thinning by bending and bending back.

As described above, DRD cans, DI cans and DTR cans, and their methods of making can each have advantages and disadvantages. Here, the present invention is intended to obtain a can having a can height as high as about twice the can diameter and a can wall thickness of about 70 to 30% of the original plate thickness like a DI can. It is an object of the present invention to provide a suitable double-sided organic resin-coated metal plate, and in particular, it is important to provide a process for producing such a can, which is currently used for cooling and lubrication in the production of DI cans. It is an object of the present invention to provide an organic resin-coated metal plate which can omit the use of an emulsion system, a water-soluble lubricant or the like. The use of a metal plate pre-coated with an organic resin eliminates the need to bake the paint during the can-making process and prevents the scattering of solvents, and eliminates the use of coolants and lubricants, allowing subsequent washing, drying and waste liquid treatment. Etc. can be omitted. That is, an object of the present invention is to provide a material which is excellent in economy and suitable for environmental protection. Here, an organic film-coated metal plate capable of providing a can having a high can height and a thin can wall thickness without using such water-based cooling, using a lubricant, and not requiring cleaning of the can after can manufacturing is disclosed. And, of course, no disclosure of such cans and their manufacture. Although not having the same purpose as the present invention, the following are related. JP-A-62-2751
No. 72 relates to an organic resin-coated metal plate for a two-piece can, and it is intended to improve the retention of a coolant (water-based cooling, lubricant) on the outer surface side where ironing is difficult. This is one of the issues. This presupposes the use of water-based cooling and the use of a lubricant, which is greatly different from the object of the present invention. Special publication 2-5
No. 01638 also processes a sheet obtained by laminating a polyester film on one or both sides of a metal sheet into a DI can. In the DI molding of this metal sheet, the washing step of the can after the can-making is carried out. Although simplified, the use of a lubricant that requires cleaning of the can after the can is required in the squeezing step, and it is considered that cleaning of the can after the can is not completely excluded. Also, JP-A-4-91825 discloses that
Water-based cooling of the thermoplastic resin coated metal plate, without using a lubricant, that is, a high-temperature volatile lubricating substance as a lubricant,
Although the thickness is reduced by bending and unbending, as shown in the examples, the degree of thinning is about 20%, which is smaller than the target value of the present invention.

[0004]

According to the present invention, the height of the can is as high as about twice the diameter of the can and the thickness of the can wall is 70 to 70 times the original plate thickness.
An object of the present invention is to provide an organic film-coated metal sheet that can be formed into a 30-inch thick two-piece can without using water-based cooling or a lubricant (hereinafter referred to as a dry method).
By reducing the thickness of the can wall to 70-30%,
The can height increases in proportion to the degree of thinning. This point
Although satisfying the object of the present invention, as the degree of thinning increases, adhesion of the mold to the outer surface of the can wall, damage to the surface film, and breakage of the can wall are more likely to occur. In particular, in the present invention, which is characterized by using water-based cooling and not using a lubricant, damage to the organic film on the outer surface of the can and rupture due to the damage are liable to occur. Also,
As the degree of processing increases, the adhesion between the base metal plate and the coating resin decreases, but it is also an object of the present invention to ensure sufficient adhesion.

[0005]

SUMMARY OF THE INVENTION According to the present invention, dry can be easily processed into a two-piece can having a thin can wall, and the processed can has sufficient pressure resistance and corrosion resistance. Another object of the present invention is to provide an organic resin-coated metal plate having sufficient adhesion between the metal plate and the coating resin even after being processed. Examples of the type of container metal plate include a steel plate (electrolytic chromic acid-treated steel plate, tinplate, etc.), an aluminum plate, and an aluminum alloy plate (hereinafter, the aluminum plate and the aluminum alloy plate are collectively referred to as an aluminum plate). Considering that an aluminum plate having a low deformation strength is superior in terms of dry workability, the present invention was limited to the aluminum plate and studied. In order to enhance the dry processability and make the strength of the can suitable for the purpose of the present invention, the yield strength of the aluminum plate is set to 15 to 50 kg / mm ² ,
Tensile strength 15-55kg / mm ² , thickness 0.15-0.50m
m, the yield ratio is 0.7 or more and less than 1. Further, in order to make the adhesion between the aluminum plate and the coating resin after processing no problem, the aluminum plate is subjected to a surface treatment, and in order to further improve the adhesion, the crystal grain size of the aluminum plate is reduced. 10 to 50 μm, center line average roughness 0.0
5 to 0.7 μm. In addition, the resin to be coated is preferably a thermoplastic resin, in particular, a crystalline polyester resin,
The thickness is preferably in the range of 5 to 50 μm and the melting point is in the range of 180 to 260 ° C., but by these, the dry processability and the corrosion resistance after the process are excellent. Suitable types of the resin include polyethylene terephthalate resin and copolymer resin mainly composed of ethylene terephthalate unit. The reason for applying a high-temperature volatile lubricant to the surface of the thermoplastic resin is to enhance dry processability. The high-temperature volatile lubricant can be removed by heating after molding, and is degreased, washed with water, and dried. And other steps can be omitted. Determine the properties of the aluminum plate and coating resin as described above,
By applying a high-temperature volatile lubricant or the like, a dry drawn ironing resin-coated aluminum plate excellent in dry workability, can strength, adhesion after working, and corrosion resistance can be obtained. Here, in order to carry out the dry processing at a higher working ratio without any problem, it is desirable that the working method is also suitable for the purpose of the present invention. An object of the present invention is to provide a resin-coated aluminum plate having excellent dry workability, can strength, adhesion after processing, and corrosion resistance. Machining method in which machining and ironing are performed under specific conditions, that is, damage to inner and outer coatings,
By processing by a thickness reducing method that hardly causes can wall breakage, the characteristics of the resin-coated aluminum plate of the present invention are more effectively exhibited.

[0006]

The reason for the limitation and the operation of the present invention will be described in detail below. In the present invention, the can wall thickness is 70-
Aiming to obtain a resin-coated metal plate that can be reduced in thickness to 30% and that has excellent can strength, corrosion resistance, and adhesion. is there. The object of the present invention is to dry-process a metal plate coated with an organic film on both sides thereof in advance, and to reduce the thickness with a large degree of processing. Heat generation, softening and melting of the outer coating due to the heat, resulting in direct contact between the base metal and the mold, and furthermore, can wall breakage. The heat generated by the processing is affected by the deformation and friction of the metal plate, and the heat generated by the deformation is smaller as the deformation resistance is smaller. Also, in the ironing process in the composite processing shown in FIG. The pressure is low, and the frictional heat generated in proportion to the surface pressure × the coefficient of friction is also reduced. Further, even if the temperature of the organic film is the same, the film damage is reduced as the surface pressure is reduced. Therefore, with respect to this film damage, the material having the smallest possible deformation resistance suitable for ironing is more suitable. In addition, since the material is subjected to drawing and redrawing before the ironing in FIG. 3, it is more suitable for the purpose of the present invention that the material hardened by the processing is smaller. For the above reasons, the base metal plate of the resin-coated metal plate of the present invention is limited to an aluminum plate.

[0007] On the other hand, the processed can is used in a state where the pressure inside the can is positive or negative, and in order to withstand such pressure, both the can bottom and the can wall must have a certain strength. In particular, when the pressure inside the can is positive, the pressure strength of the bottom of the can becomes a problem, but the pressure strength is roughly (plate thickness) ² × Yield strength. Influences. The lower limit of the yield strength, tensile strength and thickness of the aluminum plate is determined in consideration of the pressure resistance. Further, the upper limit of the yield strength and the tensile strength is determined from the viewpoint of film damage during ironing. If it is more than the upper limit, the film is likely to be damaged and the can wall is broken. Furthermore, the reason that the yield ratio expressed by yield strength / tensile strength is 0.7 or more and less than 1 is that the yield strength affecting the bottom strength of the can is high, while the yield strength after ironing affects the coating damage during ironing. The smaller the deformation resistance, the more suitable for the purpose. From that point, the upper and lower limits of the yield ratio are determined.
With respect to the upper limit of the plate thickness, there are few cases where the thickness is required to be 0.5 mm or more in terms of pressure resistance, and the upper limit is set to 0.5 m in terms of economy.
m. The lower limit of the plate thickness is limited to 0.15mm,
This is because an aluminum plate having a uniform thickness is continuously and stably produced at a high speed, and the lower limit is not intentionally limited.

Next, the organic film to be coated on the aluminum plate is made of a thermoplastic resin, preferably a crystalline polyester resin, having a thickness of 5 to 50 μm and a melting point of 1 μm.
The reason for setting the temperature to 80 to 260 ° C. will be described. The present invention is premised on dry processing, but by using a thermoplastic resin as the coating resin, the lubricating effect at the time of ironing becomes more effective. During ironing, the outer surface of the can generates heat due to friction with the ironing die, but is presumed to be softened by the heat and provide a lubricating effect. If the temperature of the ironing die is increased, the lubricating effect becomes remarkable, but if the temperature is further increased, the resin in the ironing die further softens,
It cannot withstand the surface pressure proportional to the deformation resistance of the aluminum plate, and the ironing die and the ironing die come into direct contact with each other, causing the can wall to break. Therefore, it is not preferable that the thermoplastic resin is excessively softened, and it is desirable that the temperature of the ironing die be in an appropriate temperature range, preferably 25 ° C to the glass transition temperature of the coated thermoplastic resin. On the other hand, the softening of the thermoplastic resin to be coated at a low temperature is not preferable, and the melting point is used as an index of the softness.
By setting the temperature to not less than ° C., the moldability in dry processing targeted by the present invention is improved. That is, in industrial production, drawing and ironing are performed continuously. In that case, depending on the processing conditions, the can wall temperature may be 100 ° C. or higher, and if the melting point of the resin is low, the can is softened or melted. However, the appearance is impaired and an aluminum exposed portion is formed on the inner surface of the can. Furthermore, the resin adheres to the tool, making continuous production difficult. Therefore, the melting point is desirably 180 ° C. or higher. If the melting point is 260 ° C. or higher, a sufficient lubricating effect based on softening during processing cannot be obtained. For the above reasons, the upper and lower limits of the melting point of the thermoplastic resin are determined. Further, the thickness of the thermoplastic resin is 5 to 50 μm.
However, when the thickness is 5 μm or less, the ironing die and the underlying metal are likely to come into direct contact with each other on the outer surface side of the can, increasing the risk of breakage, and having insufficient corrosion resistance on the inner surface side. On the other hand, when the thickness is 5 μm or less, stable coating work becomes difficult. On the other hand, the upper limit is that when thickened,
50 from the viewpoint of easy wrinkling and economy.
μm is the upper limit.

Examples of the polyester resin having a melting point of 180 to 260 ° C. include polyethylene terephthalate, polybutylene terephthalate, copolymerized polyester resin mainly composed of ethylene terephthalate unit, and butylene terephthalate unit. Or a polyester resin composed of a mixture thereof. Specifically, a copolymerized polyester resin comprising 75 to 95 mol% of polyethylene terephthalate and 5 to 25 mol% of polyethylene isophthalate, polyethylene sebacate or polyethylene adipate, polyethylene terephthalate Tartrate or polyester resin obtained by blending polybutylene terephthalate with the above-mentioned copolymerized polyester resin can be used.

Further, the above polyester resin is heated and melted and directly extruded and laminated on an aluminum plate from an extruder, or unstretched non-oriented or stretch-oriented film formed by a conventional film forming method. Is coated on the aluminum plate by a method such as laminating a film having the above formula on the aluminum plate by heat fusion. Impact resistance of the film after forming into a can, from the viewpoint of permeation resistance to highly corrosive contents, it is more preferable to laminate a polyester resin film having biaxial orientation orientation by heat fusion. . In that case, the plane orientation coefficient of the polyester resin film after coating by thermal fusion is 0.01 to 0.
10, 0.00-0.0 on the surface that contacts the aluminum plate
It is preferable that the coating be performed so as to be in the range of 5. That is, when the plane orientation coefficient of the surface of the coated polyester resin film in contact with the aluminum plate is 0.05 or more, the coated polyester resin film is easily peeled, which is not practical.

On the other hand, when the plane orientation coefficient of the free side of the coated polyester resin film is 0.01 or less, the biaxial orientation of the coated polyester resin film has almost disappeared. When such an aluminum plate coated with a polyester resin film is squeezed and formed into an iron can, the film is liable to crack, and the corrosion resistance and impact resistance are reduced. If the plane orientation coefficient on the free surface exceeds 0.1, the extensibility of the film becomes poor, and if the processing conditions become severe, cracks occur in the film during processing. Therefore, in the present invention, the plane orientation coefficient of the free surface of the coated polyester resin film is preferably in the range of 0.01 to 0.10, and the plane orientation coefficient of the surface in contact with the aluminum plate is 0.00 to 0.10. It is preferably in the range of 0.05. In addition, it is preferable to coat the above-mentioned polyester resin on an aluminum plate via an adhesive layer for the inner surface of a can filled with highly corrosive contents. In this case, the plane orientation coefficient of the coated polyester resin layer is preferable. Does not particularly need to be controlled as described above. Known adhesives can be used as the adhesive to be used, but a thermosetting polymer composition having an epoxy group in the molecule is more preferable, and is applied to the surface of the thermoplastic resin in contact with the aluminum plate, or dried, or It may be applied to the surface of an aluminum plate and dried.

The plane orientation coefficient of the surface of the polyester resin film in contact with the aluminum plate and the free surface are as follows:
It is determined by the following method. First, an aluminum plate coated with a polyester resin film is immersed in dilute hydrochloric acid to dissolve the aluminum plate and collect only the polyester resin. Next, the collected polyester resin film is washed with water, dried, and measured in a length direction, a width direction, and a thickness direction on each surface (the surface in contact with the aluminum plate and the free surface) using a refractometer. Measure each refractive index. Then, the plane orientation coefficient on each side of the film is determined by the following equation. A = (B + C) / 2-D where A is the plane orientation coefficient of the film, B is the refractive index in the length direction of the film, C is the refractive index in the width direction of the film,
D indicates the refractive index in the thickness direction of the film. Since the refractive index measured by the above method indicates an average value at a thickness within 5 μm from the surface of each surface of the film, the refractive index of each surface of the film (the surface in contact with the aluminum plate and the free surface) It is possible to distinguish plane orientation coefficients.

Further, in the present invention, after being coated by heat fusion, the plane orientation coefficient of the surface of the polyester resin film which is not in contact with the aluminum plate (free surface) and the surface which is in contact with the aluminum plate are controlled within a preferred range. In order to facilitate this, it is also possible to apply a polyester resin film composed of two layers, an upper resin and a lower resin, each having a different melting point.

The IV value (intrinsic viscosity, intrinsic viscosity) of the above polyester film is also one of the important factors of the present invention. The IV value is positively correlated with the molecular weight and is a factor that has a great influence on the rigidity of the film and the moldability of the resin film. That is, when the IV value is 0.5 or less,
Even if the plane orientation coefficient after coating is controlled within a suitable range, the impact resistance of the film formed into a drawn and ironed can is poor, and fine cracks are formed in the film on the inner surface side of the impacted portion. It occurs innumerably and metal parts become exposed. When the IV value is 0.70 or more, the viscous resistance during ironing is high, which may cause a practical problem.

In the present invention, it is possible to use an aluminum plate in which the outer surface of the aluminum plate can is coated with a polyester resin film colored with a pigment.
It is one of the important factors from an aesthetic point of view. That is, in order to improve the sharpness of the design printed on the outer surface of the can, a titanium oxide-based white pigment or the like can be contained in the film. As the pigments, pigments of colors other than inorganic, organic, and white are also applicable, and are selected according to the application. Good printability is obtained when the addition amount is 1 to 20%.

Further, in the present invention, bispheno-
Polyamide resins such as Poly-A polycarbonate, 6-nylon, 6,6-nylon, 6-6,6-co-polymer nylon, 6,10-nylon, 7-nylon, 12-nylon, and polyethylene It is also possible to use an aluminum plate coated with a thermoplastic resin such as naphthalate. It is also possible to apply these thermoplastic resins alone, as a two-layer composite with the polyester resin, or as an upper layer of a three-layer structure film, or as an intermediate layer, and to these thermoplastic resins, It is also possible to apply as a film made of a resin blended with the above polyester resin. Further, as the upper layer of the blended resin, it is also possible to apply a thermoplastic resin film composed of a two-layered film provided with the above polyester resin layer. In addition, for all of the above thermoplastic resins, if necessary, stabilizers as long as other properties are not impaired,
Additives such as antioxidants, antistatic agents, lubricants, corrosion inhibitors and the like can be added to the resin.

The crystal grain size and the center line average roughness of the aluminum plate affect the adhesion to the thermoplastic resin and the corrosion resistance. In the present invention, the crystal grain size of the aluminum plate is defined as follows. That is, a cross section parallel to the rolling direction of the aluminum plate was set as an observation surface, and 3 cm in a visual field at a magnification of 200 times.
The average value of the crystal grain diameters of three larger crystal grains observed in a range of × 3 cm (actual size: 150 μm × 150 μm) is defined as the crystal grain diameter of aluminum. Here, the crystal grain size of each crystal grain is an average value of the long dimension and the short dimension of the cross section of each crystal grain. Here, the long dimension is the length of the longest line segment among the line segments passing through the center of the crystal grain.
The length of a line passing through the center of the crystal grain and orthogonal to the long dimension line is defined as a short dimension. As described above, the crystal grain size is defined based on the larger crystal grain size observed on the observation surface of the aluminum cross section for the following reason. That is, assuming that all the aluminum crystal grains are spheres having the same diameter, the cross section of each crystal grain is observed as a circle having various diameters in the cross section. Of these circles of various diameters, the largest is the diameter of the sphere, that is, the true grain size. From this,
The crystal grain of the aluminum plate is defined as the larger crystal grain size observed on the observation surface of the aluminum cross section.
In the present invention, when the crystal grain size is 50 μm or more, roughening is caused in the drawing process, the adhesion is reduced, and a defect of the resin film is liable to occur, thereby deteriorating the corrosion resistance. In addition, when the crystal grain size becomes 10 μm or less, it becomes hard, and in manufacturing, rapid heating is required.
There are restrictions on facilities.

Further, regarding the center line average roughness, 0.7
If it is not less than μm, adhesion may become a problem depending on the processing conditions, and the upper limit is set to 0.7 μm. In addition, the lower limit is not from the performance point of view, but it is difficult to economically produce the one having a thickness of 0.05 μm or less.
μm is desirable.

The aluminum plate is subjected to a surface treatment in order to obtain sufficient adhesiveness with the resin film to be coated. The surface treatment is selected from chemical treatment, electrolytic chromic acid treatment, and anodizing treatment. The type of chemical conversion treatment is selected from chromate-based, phosphoric acid-chromate-based, non-chromate-based, etc. in consideration of processing conditions and processing equipment. The coating amount depends on the type of chemical conversion treatment, but is preferably in the range of 5 to 100 mg / m ² . Further, when further adhesiveness is required, electrolytic chromic acid treatment, anodizing treatment and the like are suitable.

The high-temperature volatile lubricant to be applied to the surface of the thermoplastic resin has a high degree of workability in dry processing which is an object of the present invention,
It plays an important role in running at high speed. In addition, it is desirable that the high-temperature volatile lubricant is scattered by 50% or more by heating at about 200 ° C. for several minutes after processing, and specifically, a simple substance such as liquid paraffin, synthetic paraffin, and natural wax. Alternatively, it is selected from these mixtures according to the processing conditions and the heating conditions after the processing. The lubricant has a melting point of 25 to 80 ° C and a boiling point of 180 to 40.
Those in the range of 0 ° C. are desirable to achieve the purpose of the present invention. As the coating amount, 5~100mg / m ^2, preferably 30-60 mg / m ² is applied. In selecting the coating amount, the surface to be the outer surface of the can and the surface to be the inner surface of the can are also taken into consideration.

As described above, by limiting the properties of the aluminum plate and the properties of the thermoplastic resin and applying a high-temperature volatile lubricant to the surface of the thermoplastic resin, the can height is about twice the can diameter. Thus, a thin can with a can wall thickness of about 70 to 30% of the original plate thickness can be formed into a resin-coated aluminum plate suitable for molding by dry drawing and ironing. Here, with respect to the drawing and ironing, the composite processing of simultaneously performing the redrawing and the ironing described below is applied, and by reducing the thickness of the can wall, the object of the resin-coated aluminum plate of the present invention is achieved. However, it is achieved very effectively.

An embodiment of a process for producing the resin-coated aluminum plate of the present invention into a can having a high can height and a thin wall by the processing including the above-described composite processing will be described below. First, as shown in FIG. 2, a blank 5 is punched from the resin-coated aluminum plate shown in FIG.
A step of turning the drawn can 6 into a redrawn can 7 having a smaller can diameter than the drawn can 6, and simultaneously ironing while redrawing the redrawn can 7 into a small diameter can as shown in FIG. The process of drawing and ironing can 8 by combined processing,
The upper end of the can is trimmed to be a trim can 12, and then the upper end of the can is neck-in (processing to reduce the diameter of the can) and flanged to finish the final can shown in FIG. In relation to obtaining a can having a high can height and a thin wall thickness, which is a subject of the resin-coated aluminum plate of the present invention, the role of the composite processing in the above steps is not small, and the outline of the composite processing is shown in FIG. However, in the composite machining, an ironing part 16 is arranged following the redrawing die 14, and ironing is performed while performing redrawing. By performing the ironing while effectively applying the rearward tension to the ironed portion in this way, the coating resin on the outer surface is less likely to be damaged. Further, the length L of the can wall 10 between the redrawing portion and the ironing portion is determined in consideration of a dimension to be thickened for neck-in processing thereafter. Further, if the temperature of the redrawing die 14 and the ironing die 15 is in the range of 25 ° C. to the glass transition temperature of the coating resin film, it is more effective to solve the problem of the present invention. Here, an aluminum plate having an original plate thickness of 0.25 mm is shown in FIG.
FIG. 5 shows an example of the distribution of the can wall thickness (the thickness of the aluminum plate from which the coated resin layer is peeled off) in the can height direction of the can 12 processed and trimmed according to the processing step of FIG. In FIG. 5, the thickness of the can body is 0.14 mm (40% of the original plate thickness).
The upper end of the can is as thick as about 0.20 mm (20% smaller than the original plate thickness), which is suitable for neck-in processing thereafter. Further, as can be easily understood from the processing method of FIG. 3, when the outer diameter of the punch 13 is the same as the portion corresponding to the can body and the portion corresponding to the can upper end, the can body and the upper end of the can are provided. Is formed on the outer surface of the can, and DI
This is in a state opposite to the case where the can has a thickness step on the inner surface side of the can. FIGS. 2, 3, 4 and 5 show embodiments in which a thickness step is formed on the outer surface of the can. On the other hand, as in the case of the DI can, if the outer diameter of the punch corresponding to the upper end of the can is reduced, it is needless to say that a thickness step is formed on the inner surface side of the can. Even if there is a step on the outer surface of the can, it hardly affects the appearance, and even if there is a step on the inner surface of the can, it hardly affects the removability of the punch of the can after molding. That is, even if the step is formed on either the inner surface side or the outer surface side, there is no problem in quality and manufacturing.

[0023]

【Example】

Example 1 Metal plates A, B, C, D, E, and F having the characteristics shown in Table 1
Was heated to 240 ° C., and a thermoplastic resin was coated on the inner surface or both surfaces of the can in the following manner. A biaxially stretched film of a copolyester resin composed of 88 mol% of polyethylene terephthalate and 12 mol% of polyethylene isophthalate (thickness: 25 μm, plane orientation coefficient: 0.126, Melting point: 229 ° C.), and the surface to be the outer surface of the can was coated with a biaxially stretched film (thickness: 15 μm) of a copolyester resin having the same composition as described above, which was colored white by adding a titanium oxide pigment. It was immersed in water and cooled. After coating, the coating was dried, and a paraffin-based wax was applied on both sides at about 50 mg / m ^2, and the subsequent processing was performed. First, after punching into a blank of 160 mm in diameter,
mm drawn cans. Then, by redrawing, can diameter 8
It was a 0 mm redrawable can. The redrawing can is subjected to ironing at the same time as redrawing by composite processing, and the can diameter is 66 m.
m drawn and ironed cans. In this combined processing, the interval between the redrawing processing part which is the upper end part of the can and the ironing processing part is 2
0 mm, the shoulder radius of the redrawing die is 1.5 times the plate thickness, the clearance between the redrawing die and the punch is 1.0 times the plate thickness,
The clearance of the ironed portion was tested under the condition of 50% of the original plate thickness. In each of the processes, water-based cooling and a lubricant were not used, and a dry process was performed. The presence or absence of can wall breakage, the state of the outer surface of the can, the metal exposure on the inner surface of the can, and the adhesion between the base metal and the coating resin were evaluated. In this composite processing, the molding is finished in a state where a flange is left at an upper end portion of the can, the punch is retracted, and the can after composite molding is taken out in a direction opposite to the arrow. Next, by trimming the upper end of the can, neck-in processing, and flange processing, the resin-coated aluminum plate of the present invention is intended to have a high can, a thin can wall, and a can in a state in which the lid can be further wound. Become. The rupture rate of the can wall, the state of the outer surface of the can, the metal exposure on the inner surface of the can, and the adhesion between the base aluminum plate and the coating resin were evaluated according to the following criteria. 1) Break rate of can wall ：: 0%, ○: less than 10%, Δ: 10% or more, less than 30%, ×: 30% or more 2) State of can outer surface (evaluated by the rate of occurrence of flaws) ：: 0 %, ○: less than 10%, Δ: 10% or more, less than 30%, ×: 30% or more 3) Metal exposure on the inner surface of the can (enamellator value (ERV:
）: 0 or more, less than 0.05 mA, ：: 0.05 mA or more, less than 0.5 mA, Δ: 0.5 mA or more, less than 5 mA, ×: 5 mA or more 4) Processing of coated resin layer Adhesion (evaluated by the degree of peeling after neck-in processing) ：: No peeling at all, ○: Slight peeling, but no problem in practical use, Δ: Pretty peeling, ×: The entire upper part of the can was peeled. In addition, in any of the evaluations, when there is no evaluation target, it is indicated by a symbol <<->>.

Example 2 Metal plates A and E having the characteristics shown in Table 1 were heated to 240 ° C., and both surfaces were coated with a thermoplastic resin in the following manner.
Polyethylene terephthalate 8 is placed on the inner side of the can.
Biaxially stretched film of a copolymerized polyester resin consisting of 8 mol% and polyethylene isophthalate 12 mol% (thickness: 6 μm, plane orientation coefficient: 0.126, melting point: 229)
℃), titanium oxide pigment is added to the outer surface of the can,
A biaxially stretched film (thickness: 8 μm) of a copolyester resin having the same composition as the above and colored white was coated and immediately immersed in water and cooled. After coating, the coating was dried, and about 50 mg / m ² of paraffin-based wax was applied to both surfaces, and the subsequent processing was performed under the same conditions as in Example 1.

Example 3 Metal plates A and C having the characteristics shown in Table 1 were heated to 235 ° C., and both surfaces were coated with a thermoplastic resin in the following manner. On the inner side of the can, a copolyester resin (thickness: 15 μm, upper layer comprising 88 mol% of polyethylene terephthalate and 12 mol% of polyethylene isophthalate)
(Melting point: 229 DEG C.), the lower layer of which is composed of a resin obtained by mixing 45% by weight of a copolyester resin composed of 94 mol% of polyethylene terephthalate and 6 mol% of polyethylene isophthalate, and 55% of polybutylene terephthalate. A biaxially stretched film (plane orientation coefficient: 0.123 (upper layer) composed of a film (thickness: 5 μm, melting point: 226 ° C.),
0.083 (lower layer), and the other outer surface is a white-colored biaxially stretched film (thickness: 15) as in Example 1.
μm) and immediately immersed in water and cooled. After coating,
Dry, about 50mg of paraffin wax on both sides
/ M ² and the subsequent processing was performed under the same conditions as in Example 1 and evaluated.

Example 4 Metal plates A and E having the characteristics shown in Table 1 were heated to 240 ° C., and both surfaces were coated with a thermoplastic resin in the following manner. A biaxially stretched film of a copolyester resin composed of 88 mol% of polyethylene terephthalate and 12 mol% of polyethylene isophthalate (thickness: 25 μm, plane orientation coefficient: 0.126, Melting point: 229
℃) on the side of the metal plate, an epoxy phenol resin was applied (dry weight: 0.5 g / m ² ), and a titanium oxide pigment was added to the outer surface of the can to be colored white. A biaxially stretched film (thickness: 10 μm) of a copolyester resin having the same composition as above was coated, immediately immersed in water and cooled, coated and dried, and coated with paraffin wax at about 50 mg / m ^{2 on} both sides. The processed and uncoated ones were prepared, and the subsequent processing was performed and evaluated in the same manner as in Example 1. The above results are shown in Tables 2, 3, and 4. From the results, the resin-coated aluminum plate of the present invention is suitable for obtaining a can having a high can height and a thin can wall thickness by dry processing. It turns out to be something.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

[Table 4]

[0031]

The dry drawn ironing resin-coated aluminum plate of the present invention is dry, suitable for forming a drawn ironed can having a high can height and a thin can wall.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a cross section of a resin-coated aluminum plate for a dry draw ironing can of the present invention.

FIG. 2 is a schematic view relating to one embodiment of a step of forming a dry, high-height, thin-walled can from a resin-coated aluminum plate for a dry-drawing and ironing can of the present invention.

FIG. 3 is a composite process of simultaneously performing redrawing and ironing from a resin-coated aluminum plate for a dry drawing ironing can according to the present invention, which is suitable for forming a dry, high can, and thin wall can. 3 is a schematic view schematically showing a partial cross section of FIG.

FIG. 4 is a cross-sectional view of a can formed from a resin-coated aluminum plate for a dry draw-ironing can according to the present invention.

FIG. 5 is a view showing an example of a can wall thickness profile of a can formed from a resin-coated aluminum plate for a dry draw ironing can of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 aluminum plate 2 thermoplastic resin 3 surface treatment film 4 high-temperature volatile lubricant 5 blank 6 drawn can 7 redrawn draw 8 redrawn drawn iron can 9 thin can wall 10 can upper end 11 remaining flange 12 trim can 13 punch 14 redrawn Die 15 Ironing die 16 Ironing part 17 Wrinkle holder 18 Arrow 19 Can bottom 20 Neck L Distance between redrawing part and ironing part

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ identification code FI B65D 25/14 B65D 25/14 A C22C 21/00 C22C 21/00 E (58) Fields investigated (Int. Cl. ⁷ , DB Name) B32B 15/08 B21B 1/22 B21D 22/20 B65D 25/14

Claims (4)

(57) [Claims] 1. Yield strength: 15 to 50 kg / mm ² , tensile strength: 15 to 55 kg / mm ² , center line average roughness: 0.05 to 0.7
After coating both sides of a surface-treated aluminum plate or an aluminum alloy plate having a thickness of 0.15 to 0.50 mm with a thermoplastic resin having a thickness of 5 to 50 μm, the surface is coated with a high-temperature volatile lubricant. A resin-coated aluminum plate for dry drawing and ironing cans coated with a. 2. A resin-coated aluminum plate for a dry drawing and ironing can, wherein the aluminum plate or the aluminum alloy plate according to claim 1 has a crystal grain size of 10 to 50 μm and a yield ratio of 0.7 or more and less than 1. 3. A resin-coated aluminum plate for a dry drawing and ironing can, wherein the thermoplastic resin of claim 1 is a crystalline polyester resin. 4. The resin-coated aluminum plate for a dry drawing and ironing can according to claim 1, wherein an adhesive layer is interposed between the aluminum plate or the aluminum alloy plate and the thermoplastic resin.