JP6896455B2 - Resin-coated bottle-shaped cans, their manufacturing methods, and resin-coated metal plates - Google Patents

Description

The present invention relates to a resin-coated bottle-shaped can, a method for producing the same, and a resin-coated metal plate.

The two-piece can, which consists of a cup-shaped can body and a tabbed lid, does not have the function of re-plugging once opened. Therefore, the beverage in a two-piece can has the inconvenience of having to drink it on the spot. To solve these problems, re-plugging bottle-type cans that can be attached with screw caps are becoming widespread.

As the first manufacturing method of the bottle type can, there are the following methods. First, a disk punched from a thin metal plate is subjected to drawing and ironing to form a bottomed cylindrical can in which the bottom and the body are integrated. Then, the bottom of this bottomed cylindrical can is drawn a plurality of times to form a bottomed cylindrical portion having a small diameter, and the shoulder portion is reformed to have a smooth curved surface to become a drinking spout. After opening the portion, the small-diameter cylindrical portion is screwed, beaded, and curled to obtain the mouth portion of the bottle-shaped can. Further, the lower end opening on the opposite side of the drinking spout is flanged to fit the separately prepared bottom lid, and the bottom lid is wound tightly.

Further, as a second manufacturing method of the bottle-shaped can, there is a method of processing the opening of the bottomed cylindrical can to form the shoulder portion and the neck portion. That is, first, a disk punched from a thin metal plate is subjected to drawing and ironing to form a bottomed cylindrical can in which the bottom and the body are integrated. Then, the bottomed cylindrical can is necked on the open end side of the body portion to form the shoulder portion and the neck portion cylindrical portion to obtain a bottle-shaped intermediate molded product. After that, the cylindrical portion of the neck is screwed and beaded, and the open end is curled to form the neck into the final shape.

By the way, conventionally, a paint has been applied to the inner and outer surfaces of metal cans filled with beverages such as coffee, juice, and beer for the purpose of preventing corrosion.

In Patent Document 1, in the second manufacturing method described above, an inner surface coating material containing an epoxy-acrylic copolymer resin and a phenol resin is applied to the inner surface of a bottomed cylindrical can before the necking process, and then the inner surface coating material is applied. A method for forming a bottle-shaped can by performing necking, screwing, beading, and curling is described.

Japanese Unexamined Patent Publication No. 2005-8166

In recent years, the application of paint to the inner surface of a metal container is concerned about the harmfulness of the eluate from the coating film to the human body and the adverse effect of the solvent on the environment.

On the other hand, in the production of two-piece cans, a technique for molding a two-piece can from a resin-coated metal plate obtained by laminating a polyester-based film on a metal plate made of a metal such as steel, tin, or aluminum has been put into practical use. ing.

Considering the manufacturing efficiency and the problems associated with the application of the paint, it is desirable to manufacture a bottle-shaped can in which the neck, shoulders, body and bottom are integrated from the resin-coated metal plate by the above-mentioned second manufacturing method.

However, when the present inventors try to mold a bottle-shaped can from a resin-coated metal plate, problems such as peeling of the coating resin at the neck of the bottle-shaped can and peeling of the hair-like coating resin at the curl are likely to occur. I found.

An object of the present invention is to make it possible to manufacture a resin-coated bottle-shaped can in which a neck, shoulder, body and bottom are integrally formed from a resin-coated metal plate.

According to the first aspect of the present invention, the aluminum plate ^{, a pair of chemical conversion films located on both sides thereof, each containing chromium in the range of 5 to 50 mg / m 2} , and the pair of chemical conversion films containing polyester. A resin-coated metal plate containing a pair of resin layers coating each film is subjected to drawing processing, one or more re-drawing processing and / or ironing processing, and trimming processing to form a cup shape. A first intermediate is formed, and the opening of the first intermediate is necked to form a second intermediate having a neck, shoulder, body and bottom, and the second intermediate is formed. Provided is a resin-coated bottle-shaped can obtained by screwing, beading, and curling the neck of the body.

According to the second aspect of the present invention, a resin used for producing a resin-coated bottle-shaped can in which a neck portion, a shoulder portion, a body portion and a bottom portion are integrally molded and the neck portion has a screw portion, a bead portion and a curl portion. A coated metal plate, the aluminum plate, a pair of chemical conversion films located on both sides of the aluminum plate, each ^{containing chromium in the range of 5 to 50 mg / m 2} , and the pair of chemical conversion films containing polyester. A resin-coated metal plate including a pair of resin layers each coating a film is provided.

According to the third aspect of the present invention, the aluminum plate ^{, a pair of chemical conversion films located on both sides thereof, each containing chromium in the range of 5 to 50 mg / m 2} , and the pair of chemical conversion films containing polyester. The resin-coated metal plate containing the resin layer covering each film is subjected to drawing processing, one or more re-drawing processing and / or ironing processing, and trimming processing to obtain a cup-shaped first. A step of forming the intermediate body of No. 1, a step of performing a necking process on the opening of the first intermediate body to form a second intermediate body having a neck, a shoulder portion, a body portion and a bottom portion, and a step of forming the first intermediate body. The step of screwing, beading, and curling the neck of the intermediate body of No. 2, and the area to be threaded, the area to be beaded, and the area to be beaded before, after, or in the middle of the necking. Provided is a method for producing a resin-coated bottle-shaped can, which comprises a step of heating one or more regions of a region to be curled one or more times to make the resin layer non-oriented in the region.

According to the present invention, it is possible to manufacture a resin-coated bottle-shaped can in which a neck, shoulder, body and bottom are integrally formed from a resin-coated metal plate.

A cross-sectional view schematically showing a resin-coated bottle-shaped can according to an embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view showing a part of the resin-coated bottle-shaped can of FIG. (A) is a side view schematically showing a resin-coated metal plate, and (B) is a side view schematically showing a state in which the resin-coated metal plate of (A) is drawn in a cup shape. (C) is a side view schematically showing a state in which the structure shown in FIG. 3 (B) is subjected to the first re-drawing process, and (D) is a side view showing the state in which the structure shown in (C) is subjected to the second re-drawing process. A side view schematically showing the state shown in (E), a side view roughly showing the state in which the structure shown in (D) is ironed and bottom-molded, and (F) is a broken line of the structure shown in (E). A side view schematically showing a first intermediate obtained by trimming in a portion. (G) is a side view schematically showing a state in which the opening of the first intermediate of FIG. 4 (F) is necked, and (H) is a structure further subjected to necking to the structure shown in (G). A side view schematically showing a state, (I) is a side view roughly showing a second intermediate obtained by necking, and (J) is a screwing process on the second intermediate of (I). , A side view schematically showing a resin-coated bottle-shaped can obtained by beading and curling.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Elements having the same or similar functions are designated by the same reference numerals, and duplicate description will be omitted.

<Resin-coated bottle-shaped can>
FIG. 1 is a cross-sectional view schematically showing a resin-coated bottle-shaped can 100 according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of the resin-coated bottle-shaped can 100 of FIG.

The resin-coated bottle-shaped can 100 shown in FIG. 1 integrally has a bottom portion 10, a body portion 20, a shoulder portion 30, and a neck portion 40. Further, as shown in FIG. 2, the resin-coated bottle-shaped can 100 shown in FIG. 1 is coated with an aluminum plate 110, a pair of chemical conversion films 120 located on both sides thereof, and a pair of chemical conversion films 120, respectively. It contains a pair of resin layers 130.

The resin-coated bottle-shaped can 100 preferably has a volume of 250 mL to 500 mL. The resin-coated bottle type can 100 is, for example, a 290 mL bottle can, a 300 mL bottle can, or a 400 mL bottle can.

The height H1 of the resin-coated bottle-shaped can 100 is preferably in the range of 120 mm to 200 mm, and more preferably in the range of 129 mm to 197 mm. For example, in the case of a 290 mL bottle can, the height H1 can be 131 mm, in the case of a 300 mL bottle can, the height H1 can be 133 mm, and in the case of a 400 mL bottle can, the height H1 can be 164 mm. Can be.

As shown in FIG. 1, the bottom portion 10 is recessed in a dome shape toward the internal space of the resin-coated bottle-shaped can 100. Since the resin-coated bottle-shaped can 100 has such a structure, the bottom portion 10 is less likely to be deformed even when the internal pressure of the can is increased. The bottom portion 10 may be flat.

The thickness T1 of the aluminum plate 110 at the bottom 10 is preferably in the range of 0.22 mm to 0.40 mm, more preferably in the range of 0.24 mm to 0.32 mm.

The body portion 20 communicates between the bottom portion 10 and the shoulder portion 30 with a constant outer diameter. The outer diameter W1 of the body portion 20 is preferably in the range of 50 mm to 70 mm, and more preferably in the range of 52 mm to 67 mm. The height H4 of the body portion 20 is preferably in the range of 60 mm to 140 mm, and more preferably in the range of 75 mm to 130 mm.

In the body portion 20, the thickness T2 of the aluminum plate 110 at the intermediate position between the bottom portion 10 and the shoulder portion 30 is preferably in the range of 0.08 mm to 0.20 mm, preferably 0.10 mm to 0.18 mm. It is more preferable that it is within the range. Further, the thickness T3 of the aluminum plate 110 at a position adjacent to the shoulder portion 30 of the body portion 20 is preferably in the range of 0.16 mm to 0.24 mm, and is in the range of 0.17 mm to 0.23 mm. It is more preferable to be in.

Typically, in the body portion 20, the plane orientation coefficient ΔP of the resin layer 130 is small. For example, in the production of the resin-coated bottle-shaped can 100, when a heat treatment for reducing the degree of orientation of the resin layer 130 is performed on the entire structure after forming the body 20, the surface orientation of the resin layer 130 on the body 20 is formed. The coefficient ΔP is 0.04 or less. Further, when the above heat treatment is performed only on the portion corresponding to the neck portion 40 or the portion corresponding to the shoulder portion 30 and the neck portion 40, the plane orientation coefficient ΔP of the resin layer 130 in the body portion 20 is, for example, It is in the range of 0.05 to 0.08.

Here, the plane orientation coefficient ΔP measures the maximum refractive index Nx in the plane, the refractive index Ny in the direction orthogonal to the direction showing the maximum refractive index Nx in the plane, and the refractive index Nz in the thickness direction. However, it is a value calculated from the following formula using these measurement results.
ΔP = (Nx + Ny) /2-Nz
The refractive indexes Nx, Ny and Nz can be measured using, for example, an Abbe refractometer. Measurements using an Abbe refractometer are specified in JIS K7142: 2014 (“Plastic-How to determine the refractive index”).
By the way, when a smooth test piece having a size sufficient for measurement with an Abbe refractometer cannot be collected, the plane orientation coefficient cannot be directly obtained. In such a case, it may be measured by an X-ray diffractometer. The degree of orientation of the polyethylene terephthalate film is obtained from the diffraction intensity near the diffraction angle 2θ = 26 °, and it is known that there is a correlation between the X-ray diffraction intensity and the plane orientation coefficient. The plane orientation coefficient can be found by finding the relationship.

When the plane orientation coefficient ΔP is 0.04 or less, it is assumed that the orientation state of the polymer constituting the resin layer is non-orientation.

The shoulder portion 30 is located between the body portion 20 and the neck portion 40, and the diameter is reduced from the body portion 30 to the neck portion 40. The height H3 of the shoulder portion 30 is preferably in the range of 10 mm to 60 mm, more preferably in the range of 15 mm to 45 mm.

In the shoulder portion 30, the thickness T4 of the aluminum plate 110 is preferably in the range of 0.18 mm to 0.36 mm, and more preferably in the range of 0.19 mm to 0.30 mm.

In the production of the resin-coated bottle-shaped can 100, when the heat treatment for reducing the degree of orientation of the resin layer 130 is performed on the portion including the shoulder portion 30 or the entire portion after forming the shoulder portion 30, the resin layer 130 on the shoulder portion 30 The plane orientation coefficient ΔP of is, for example, 0.04 or less. When the above heat treatment is performed only on the neck 40 after the shoulder 30 is formed, the plane orientation coefficient ΔP of the resin layer 130 on the shoulder 30 is, for example, in the range of 0.05 to 0.08. Is inside.

The neck 40 is in contact with the shoulder 30. The neck portion 40 has a curl portion 41, a screw portion 42, and a bead portion 43. The outer diameter W2 of the neck portion 40 is preferably in the range of 26 mm to 48 mm, and more preferably in the range of 27 mm to 47 mm. The height H2 of the neck portion 40 is preferably in the range of 15 mm to 55 mm, more preferably in the range of 25 mm to 36 mm.

The thickness T5 of the aluminum plate 110 at the position adjacent to the shoulder portion 30 in the neck portion 40 is preferably in the range of 0.25 mm to 0.39 mm, and is in the range of 0.26 mm to 0.37 mm. Is more preferable.

Typically, at the neck 40, the plane orientation coefficient ΔP of the resin layer 130 is large. For example, the plane orientation coefficient ΔP of the resin layer 130 at the neck 40 is in the range of 0.06 to 0.09.

The curled portion 41 is an open end at the upper end of the neck portion 40, and is a portion curled to the outside. The curl portion 41 may be an open end at the upper end of the neck portion 40 and may be a portion curled inward. The outer diameter W3 of the curl portion 41 is preferably in the range of 23 mm to 45 mm, and more preferably in the range of 24 mm to 43 mm.

The ratio W1 / W3 of the outer diameter W1 of the body portion 20 to the outer diameter W3 of the curl portion 41 is preferably 1.2 or more, and more preferably 1.7 or more. The larger the ratio W1 / W3, the more useful the technique described here. Although there is no upper limit to the ratio W1 / W3, most bottle-type cans have a ratio W1 / W3 of 2.7 or less.

In the curl portion 41, the thickness T6 of the aluminum plate is preferably in the range of 0.25 mm to 0.39 mm, and more preferably in the range of 0.26 mm to 0.37 mm.

The threaded portion 42 is located below the curled portion 41 and is provided with a thread groove or a thread. The threaded portion 42 is screwed with a cap (not shown). This makes it possible to re-plug the resin-coated bottle-shaped can. Caps not shown are, for example, pilfer-proof caps.

The bead portion 43 is located below the threaded portion 42 and has a reduced diameter, and has a groove extending along the circumferential direction of the neck portion 40. The bead portion 43 is formed so that, for example, after opening the above-mentioned pilfer-proof cap, the lower end portion of the skirt portion of the cap is locked to the side wall of the groove.

<Manufacturing method of resin-coated bottle cans>
The resin-coated bottle-shaped can 100 shown in FIG. 1 is manufactured, for example, by the method shown in FIGS. 3 to 5. FIG. 3A is a side view schematically showing a resin-coated metal plate. FIG. 3B is a side view schematically showing a state in which the resin-coated metal plate 100a of FIG. 3A is drawn in a cup shape. FIG. 4C is a side view schematically showing a state in which the structure 100b shown in FIG. 3B is subjected to the first redrawing process. FIG. 4D is a side view schematically showing a state in which the structure 100c shown in FIG. 4C is subjected to the second redrawing process. FIG. 4 (E) is a side view schematically showing a state in which the structure 100d shown in FIG. 4 (D) is ironed and bottom-molded. FIG. 4F is a side view schematically showing a first intermediate 100f obtained by trimming the structure 100e shown in FIG. 4E with a broken line portion BL. 5 (G) is a side view schematically showing a state in which the opening of the first intermediate 100f of FIG. 4 (F) is necked. FIG. 5 (H) is a side view schematically showing a state in which the structure 100 g shown in FIG. 5 (G) is further subjected to necking processing. FIG. 5 (I) is a side view schematically showing the second intermediate 100i obtained by performing the necking process. 5 (J) is a side view schematically showing a resin-coated bottle-shaped can 100 obtained by subjecting the second intermediate 100i of FIG. 5 (I) to screwing, beading, and curling. The methods shown in FIGS. 3 to 5 will be described below in order of steps.

(Preparation)
Prior to the production of the resin-coated bottle-shaped can 100 shown in FIG. 1, the resin-coated metal plate 100a shown in FIG. 3 is prepared.
As shown in an enlarged cross-sectional view of a part of the resin-coated bottle-shaped can 100 of FIG. 2, the resin-coated metal plate 100a covers an aluminum plate, a pair of chemical conversion films located on both sides thereof, and these chemical conversion films, respectively. It contains a pair of resin layers. The resin-coated metal plate 100a shown in FIG. 3A is in a state before being processed by a press or the like. Therefore, the resin-coated metal plate 100a shown in FIG. 3A is different in thickness and the like of each layer from the plate constituting the resin-coated bottle-shaped can 100 shown in FIG.

As the aluminum plate contained in the resin-coated metal plate 100a, an aluminum plate made of pure aluminum may be used, or an aluminum alloy plate made of aluminum containing a small amount of alloying metals such as copper, magnesium, manganese and iron. May be used. As such an aluminum alloy plate, for example, A3004 material or A3104 material can be used. The thickness of the aluminum plate is determined according to the size of the can and the application. The thickness of the aluminum plate 110 is preferably in the range of, for example, 0.22 mm to 0.40 mm. The aluminum plate 110 having such a thickness is advantageous in achieving high moldability, high resistance to a capping load at the time of filling the contents, and excellent economy.

The chemical conversion film 120 contained in the resin-coated metal plate is a film formed by surface treatment applied to both surfaces of the aluminum plate 110. The surface treatment is preferably a phosphoric acid chromate treatment. Phosphate chromate treatment is a known method, for example, a method of immersing an aluminum plate in a phosphoric acid chromate treatment liquid, or a method of spraying a treatment liquid on an aluminum plate and then washing and drying the aluminum plate. , Phosphate chromate treatment liquid can be applied to an aluminum plate, and then heated and dried. By applying the phosphoric acid chromate treatment, corrosion of the aluminum plate is less likely to occur.

The total amount of chromium contained in the chemical conversion film is in the range of ^{5 mg / m 2 to} 50 mg / m ^2. The total amount of chromium contained in the chemical conversion film is preferably in the range of ^{10 mg / m 2 to} 30 mg / m ² , and more preferably in the range of ^{10 mg / m 2 to} 20 mg / m ^2. The total amount of chromium can be measured by a conventionally known method, for example, a fluorescent X-ray analyzer. If the total amount of chromium is too small, the adhesive force between the aluminum plate and the resin layer may be insufficient for molding the neck portion 40. Further, if the total amount of chromium is too large, the chemical conversion film may be cracked during processing, and the resin layer may be easily peeled off from the aluminum plate. It is considered that this is because the chemical conversion film has a property of being easily cracked, and if the film thickness becomes too large, the chemical conversion film itself cannot withstand advanced processing and coagulation failure is likely to occur.

The total amount of chromium can be adjusted, for example, by changing at least one of the treatment time and the treatment temperature of the phosphoric acid chromate treatment.

The resin layer contained in the resin-coated metal plate 100a contains polyester and covers each pair of chemical conversion films. Each of these resin layers may have a single-layer structure or a multi-layer structure. Among these resin layers, the thickness of the first resin layer constituting the inner surface of the resin-coated bottle-shaped can 100 is preferably in the range of 10 μm to 30 μm, and more preferably in the range of 18 μm to 25 μm. preferable. Further, among these resin layers, the thickness of the second resin layer constituting the outer surface of the resin-coated bottle-shaped can 100 is preferably in the range of 8 μm to 20 μm, and preferably in the range of 10 μm to 15 μm. More preferred.

It is preferable to use an isophthalic acid copolymer polyethylene terephthalate resin for the resin layer.

In this case, the molar fraction of the isophthalic acid component in the dicarboxylic acid contained in the resin layer is preferably in the range of 1.5 to 15%, and more preferably in the range of 3 to 10%. When the molar fraction of the isophthalic acid component is within the above range, it is particularly advantageous for the adhesion between the aluminum plate and the resin layer and the ironing workability. If the mole fraction of the isophthalic acid component in the dicarboxylic acid is too small, the adhesion between the aluminum plate and the resin layer is low, and the resin layer may peel off at the molding stage. Further, if the molar fraction of the isophthalic acid component in the dicarboxylic acid is too large, crater-like rough skin may occur on the surface in the heating step of the molding step. It is considered that this rough skin is caused by an increase in low molecular weight components in the resin layer.

The molar fraction of the terephthalic acid component in the dicarboxylic acid contained in the resin layer is preferably in the range of 75 to 98.5%, more preferably in the range of 84 to 97%. If the mole fraction of the terephthalic acid component in the dicarboxylic acid is too small, crater-like rough skin may occur on the surface in the heating step of the molding step. Further, if the mole fraction of the terephthalic acid component in the dicarboxylic acid is too large, the adhesion between the aluminum plate and the resin layer is low, and the resin layer may be peeled off at the molding stage.

In the isophthalic acid copolymerized polyethylene terephthalate resin, terephthalic acid is a part of dicarboxylic acid other than terephthalic acid and isophthalic acid (hereinafter, "other", as long as it does not impair the laminating property on an aluminum plate and the characteristics at the time of can molding. It may be replaced with "dicarboxylic acid component"). The molar fraction of the other dicarboxylic acid component in the dicarboxylic acid contained in the resin layer is preferably 10% or less, more preferably 6% or less. Other dicarboxylic acid components include, for example, dimer acid, succinic acid, adipic acid, trimellitic acid, azelaic acid, sebacic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,12-. Dodecanoic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like can be used. As the other dicarboxylic acid component, one type may be used alone, or two or more types may be used within the above-mentioned mole fraction range.

A part of ethylene glycol may be replaced with another diol component as long as the laminate property on the aluminum plate and the characteristics at the time of can molding are not impaired. The mole fraction of the other diol component in the diol component is preferably 10% or less, more preferably 6% or less. As other diol components, for example, diethylene glycol, 1,4-butanediol, neopentyl glycol, cyclohexanedimethanol and the like can be used. As the other diol component, one type may be used alone, or two or more types may be used within the above-mentioned mole fraction range.

The resin layer preferably has an ultimate viscosity (IV) of 0.65 dL / g or more, and more preferably 0.7 dL / g or more. If the ultimate viscosity (IV) is too small, crater-like rough skin may occur on the surface in the heating step of the molding step. This is considered to be due to the excessive amount of low molecular weight components in the resin layer. The larger the ultimate viscosity (IV) is, the more preferable it is, but it is technically difficult to make it 0.8 dL / g or more. The ultimate viscosity (IV) can be determined by the method specified in JIS K7367-1: 2002 ("Plastic-How to determine the viscosity of a polymer diluted solution using a capillary viscometer-Part 1: General rules"). it can.

When the resin layer contained in the resin-coated metal plate 100a has a multi-layer structure, it is preferable that each of the layers constituting the resin layer satisfies the above-mentioned conditions regarding the ultimate viscosity of the resin and the resin composition.

The resin layer may contain a modifier as long as it does not impair the laminateability on the aluminum plate and the characteristics during can molding. As the modifier, an antiblocking material, an antioxidant, a heat stabilizer, a coloring pigment, and a slipperiness improving material such as polyethylene wax can be used.

As a means for providing the resin layer on the aluminum plate coated with the chemical conversion film, known means such as a film laminating method and an extrusion laminating method can be used. The film laminating method is, for example, a method in which a resin film is sandwiched between a heated aluminum plate and laminate rolls installed on both sides of the heated aluminum plate, and the film is melt-bonded by the heat of the aluminum plate. The extrusion laminating method is, for example, a method of coating a molten resin extruded from an extruder onto an aluminum plate via a T-die.

The resin-coated bottle-shaped can 100 shown in FIG. 1 does not contain an adhesive between the aluminum plate 110 and the resin layer 130. However, the resin layer may be laminated on the aluminum plate by sandwiching an adhesive layer having a thickness within a range that does not impair the laminateability on the aluminum plate and the characteristics at the time of can molding. When the adhesive layer is included, the thickness of the adhesive layer is preferably in the range of 0.5 μm to 3 μm. If the thickness of the adhesive layer is too large, the processability after curing is inferior to that of the resin layer, and the resin layer may be peeled off at the molding stage of the neck portion 40. As the adhesive, thermosetting adhesives such as epoxy / phenol, epoxy / melamine, polyester / phenol, and polyester / melamine can be used.

(Punching process)
In the punching step, the prepared resin-coated metal plate 100a is punched by a press, for example, in a disk shape.

Prior to punching by pressing, both sides of the prepared resin-coated metal plate 100a may be coated with a molding lubricant. Here, as the molding lubricant, synthetic paraffin, liquid paraffin, natural wax, cooking oil and the like can be used. As the molding lubricant, one of these may be applied alone, or two or more of them may be applied. The molding lubricant may be applied by a known method.

The punching by pressing is preferably performed so that the resin-coated metal plate 100a is punched in a disk shape. By punching in a disk shape, the material is less likely to be wasted in the molding of the can, which is advantageous in achieving excellent economic efficiency. When the resin-coated metal plate 100a is punched into a disk shape, the diameter of the disk is preferably in the range of 120 mm to 180 mm, more preferably in the range of 130 mm to 170 mm.

(Cupping process)
In the cupping step, the resin-coated metal plate 100a shown in FIG. 3A is drawn. As a result, the structure 100b shown in FIG. 3 (B) is obtained. The structure 100b is a bottomed cylindrical can having a bottom portion 10 and a body portion 20.

(Redrawing and / or ironing process)
Next, the structure 100b is subjected to one or more redrawing and / or ironing. As a result, for example, as shown in FIGS. 4 (C) to 4 (E), the structure 100b is expanded and reduced in diameter. That is, first, redrawing is performed to obtain a structure 100c having a higher diameter and a smaller diameter as compared with the structure 100b, as shown in FIG. 4 (C). Next, the second redrawing process is performed to obtain a structure 100d having a higher diameter and a smaller diameter as compared with the structure 100c, as shown in FIG. 4 (D). Subsequently, ironing is performed and bottom molding is performed to obtain a structure 100e having a dome-shaped recess at the bottom 10 which is higher than the structure 100d as shown in FIG. 4 (E).

The redrawing and / or ironing is performed by, for example, an apparatus (body maker) equipped with one or more redrawing dies, one or more ironing dies, and a punch. Redrawing and / or ironing is usually performed 3 to 4 times in total.

(Trimming process)
Subsequently, the structure 100e is trimmed to cut the open end at the position of the broken line portion BL shown in FIG. 4 (E). As a result, the first intermediate 100f is obtained. Here, the broken line portion BL is a line perpendicular to the height direction of the resin-coated bottle type can 100.

(Printing and / or painting process)
When the resin-coated bottle-shaped can 100 is printed and / or painted, it is preferable to print and / or paint the first intermediate 100f. In this case, the molding lubricant adhering to the first intermediate 100f may be removed prior to printing and / or painting on the first intermediate 100f. The molding lubricant can be removed, for example, by blowing hot air at 150 to 200 ° C. onto the first intermediate 100f. Since the first intermediate body 100f has a structure before the shoulder portion 30 and the neck portion 40 are formed, the body portion 20 maintains the linearity, and it is easy to print and / or paint.

When the first intermediate 100f is printed and / or painted, the thermosetting of the printing ink and / or the paint may be accelerated by heating in a heating / drying oven at 200 ° C. to 230 ° C., for example. When the printed shrink film is wound around a can after being filled with the contents, the printing and / or painting steps can be omitted.

(Necking process)
Next, the opening of the first intermediate 100f is subjected to a necking process. As a result, the second intermediate 100i shown in FIG. 5 (I) is obtained. In the necking step, for example, as shown in FIGS. 5 (G) and 5 (H), the diameter of the opening of the first intermediate 100f is reduced. That is, first, as shown in FIG. 5 (G), a structure 100 g having an opening diameter smaller than that of the first intermediate 100 f is obtained. Next, as shown in FIG. 5 (H), a structure 100h having an opening diameter smaller than that of the structure 100g is obtained. Such a diameter reduction is performed in a plurality of stages to obtain a second intermediate 100i having a neck portion 40, a shoulder portion 30, a body portion 20 and a bottom portion 10 integrally as shown in FIG. 5 (I). The necking process is usually performed in 4 to 40 steps depending on the smoothness of the shoulder curve required for appearance.

In this necking process, as shown in FIG. 5 (I), a tapered portion which is a shoulder portion 30 and a straight portion which is a neck portion 40 are formed in the vicinity of the opening. This straight portion has a reduced diameter with respect to the body portion 20, and is a portion where screw processing, bead processing, and curling processing are performed.

The height of the reduced diameter straight portion is preferably 15 mm or more. If the height of the reduced diameter straight portion is low, a sufficient number of threads or threads cannot be formed, and it becomes difficult to secure the sealing property at the time of capping.

As the straight portion, a multi-stage straight portion having a diameter suitable for each machining may be formed, such as a straight portion for bead processing, a straight portion for screw processing, and a straight portion for curling processing.

Further, when curling, it is not preferable that the tip of the opening is distorted in the circumferential direction. Therefore, when such distortion becomes a problem, the opening end portion of the second intermediate 100i may be trimmed to adjust the shape in the vicinity of the opening portion.

Prior to the necking process, it is preferable to recoat the first intermediate 100f with the molding lubricant described above. Further, the coating with the molding lubricant is preferably performed between the heat treatment described later, specifically, the heat treatment for non-alignment of the resin layer, and the subsequent necking process.

Before, after, or in the middle of the necking process, one or more heat treatments are performed on one or more areas of the area to be threaded, the area to be beaded, and the area to be curled. , It is preferable to make the resin layer non-oriented. The details of the heat treatment will be described later.

(Screw processing, bead processing, and curl processing process)
After the necking and heat treatment, the neck 40 of the second intermediate 100i is screwed, beaded and curled. Threading, beading and curling are performed, for example, as follows. First, a screw groove for screwing a cap is provided in the cylindrical portion of the neck portion 40 to form the screw portion 42. The screw processing is performed, for example, by pressing the screw forming rollers from the inner surface side and the outer surface side of the cylindrical portion of the neck portion 40, respectively. A bead portion 43 is formed below the screw portion 42 at the same time as the screw processing or following the screw processing. The bead portion 43 is formed by forming an annular recess extending inward along the circumferential direction of the neck portion 40. Subsequently, the open end portion of the neck portion 40 is processed into an outer winding by a curl molding apparatus to form the curl portion 41. The order of screwing, beading, and curling may be changed. Further, the open end may be trimmed before the curling process is performed.

(Heat treatment)
It is preferable to heat one or more regions of the region to be screwed, the region to be beaded, and the region to be curled one or more times to make the resin layer non-oriented in the region. Heating is performed after printing and / or painting, before necking, after necking, before screwing, beading and curling, or during necking. It is preferable to carry out with. It is more preferable that at least one heat treatment is performed after printing and / or painting and before the necking process. When the heat treatment is performed at such a timing, the ink and the clear coat can be cured in the first half of the process of passing through one oven, and the resin layer can be melted in the second half. This process is advantageous in achieving low equipment costs, low heating energy, and low thermal degradation of the resin layer.

In order to make the resin layer non-oriented in the region to be subjected to screwing, beading and curling, the surface temperature of the above region is set to "melting point of coating resin -10 ° C" to "melting point of coating resin + 50 ° C". It is preferably within the range, and more preferably within the range of "melting point of coating resin −5 ° C." to "melting point of coating resin + 20 ° C.".

Here, the melting point of the coating resin is the reading temperature of the endothermic peak when a 5 mg sample is measured at a heating rate of 10 ° C. per minute with a differential scanning calorimeter (DSC), and indicates melting. The endothermic reaction begins abruptly about 10 ° C. below its peak (melting point). By heating the resin layer in such a temperature range, the orientation of the molecules constituting the resin layer becomes random, and the resin layer is less likely to be peeled off during the subsequent processing.

If the surface temperature is too low, the resin layer will not melt sufficiently and the molecules that make up the resin layer will be oriented, making it impossible to sufficiently prevent the resin layer from peeling off during subsequent processing. There is a risk. Further, if the surface temperature is too high, the melt viscosity of the coating resin is excessively lowered, and there is a possibility that a crater-like appearance defect may occur on the surface of the bottle-shaped can. It is considered that this is because the thermal decomposition of the resin layer starts and the low molecular weight components increase.

It is preferable that the heat treatment is performed so as to heat all the regions to be subjected to the screw processing, the region to be beaded, and the region to be curled. The heat treatment is preferably performed in a bottom-up posture using a heating oven so that only the tip of the opening of the intermediate touches the conveyor. Further, at this time, it is preferable that the plurality of intermediates are arranged so as not to come into contact with each other, and this state is maintained until the intermediates leave the heating oven and the resin layer cools and solidifies.

The method for cooling and solidifying the resin layer is not particularly limited. Examples of the method of cooling and solidifying the resin layer include a method of forcibly cooling by providing a cooling zone to which air below room temperature is supplied at the outlet of the heating oven. According to this method, it is possible to save the installation area of the production line. The heating and cooling may be performed only on the region to be processed, or may be performed on the entire region.

When the resin-coated metal plate 100a is subjected to drawing molding, drawing ironing molding, or the like to form a cup-shaped three-dimensional shape, the polymers constituting the resin layer are oriented in the height direction on the side wall portion thereof. Produces oriented crystals. However, in the heat-treated region, the oriented state of the polymer constituting the resin layer disappears and the resin layer is not oriented. The state of these orientations can be examined by an Abbe refractometer, an X-ray diffractometer, or the like.

This heat treatment may be omitted when the ratio W1 / W3 of the outer diameter W1 of the body portion 20 to the outer diameter W3 of the curl portion 41 is less than 1.2. When the degree of deformation due to processing is small, the decrease in the adhesion of the resin layer to the aluminum plate is not so large. Therefore, in this case, peeling of the resin layer can be prevented during screwing, beading, or curling without the above heat treatment. Further, if the above heat treatment is omitted, the energy consumed in the production of the resin-coated bottle-shaped can 100 can be saved.

When the ratio W1 / W3 of the outer diameter W1 of the body portion 20 to the outer diameter W3 of the curl portion 41 exceeds 2.0, it is preferable to perform the above heat treatment at least once during the necking process performed in multiple stages. .. In this case, the above heat treatment may be further performed before the necking process, or the above heat treatment may not be performed before the necking process.

As described above, when this heat treatment is performed, it is preferable to recoat with the molding lubricant before the subsequent press working.

<Filling process and capping process>
The resin-coated bottle-shaped can 100 described above is usually filled with the contents and capped. According to one example, the content is a liquid such as a beverage. For capping, for example, a pilfer proof cap is used.

The pilfer proof cap includes, for example, a cap body and a flexible resin layer.
The cap body is, for example, a molded product made of a resin-coated metal plate. The cap body includes a circular top plate and a side wall that cylindrically protrudes from the peripheral edge of one of the main surfaces. Perforated slits are provided in the circumferential direction on the side wall portion of the cap body, that is, the skirt portion of the pilfer cap.

The flexible resin layer is provided on the main surface of the top plate portion. When the resin-coated bottle-shaped can 100 is capped, the flexible resin layer comes into close contact with the curl portion 41 to ensure the sealed state of the bottle-shaped can containing the contents.

At the time of capping, this pilfer proof cap is put on the neck 40 of the resin-coated bottle can 100, and a predetermined load is applied to the entire top plate portion to maintain the curl portion 41 biting into the flexible resin while capping the cap. By forming the side wall portion of the cap body so that the thread cutting roll approaches from the side of the cap body and traces the threaded portion 42, the sealed state of the bottle can containing the contents is maintained.

Further, during capping, the lower end of the skirt portion of the pilfer proof cap is reduced in diameter so as to be in close contact with the wall surface of the groove provided in the bead portion 43. This way, when you rotate the pilfer proof cap to open it, the part of the pilfer proof cap that is above the perforated slit will lift up and the rest of the pilfer proof cap will be lifted. Due to the engagement between the lower end of the skirt and the bead 43, it cannot move upward and stays in place. As a result, the bridge between the slits is broken, and the latter portion is separated from the former portion in a ring shape and remains on the bead portion 43 of the resin-coated bottle-shaped can 100. Whether or not the bottle-shaped can containing the contents is unopened can be determined by whether or not the bridge is broken. Therefore, accidents due to mischief can be prevented.

As described above, screwing, beading, and curling are indispensable for the resin-coated metal can, and there must be no peeling defect of the coated resin in the portion.

<Effect>
According to the method of molding a bottle-shaped can having an integral structure from a resin-coated metal plate, a bottle-shaped can with a small amount of eluate from the resin layer can be manufactured without the problem of solvent generated when the resin layer is formed by using paint. It is possible to do. Further, in such a resin-coated bottle-shaped can, since the bottom portion, the body portion, the shoulder portion, and the neck portion are integrally molded, high manufacturing efficiency can be achieved.

However, in such a method, a resin-coated metal plate punched into a disk shape is subjected to various press workings to form a complicated three-dimensional shape. Adhesion to the board is reduced, and peeling is likely to occur. This peeling problem is particularly remarkable when the ratio of the outer diameter of the body portion to the outer diameter of the curl portion is 1.2 or more.

On the other hand, in the above-mentioned method, even if the opening of the bottomed cylindrical can is processed to form a resin-coated bottle-shaped can, the coating resin at the neck is peeled off, the hair-like coating resin at the curl is peeled off, and the like. Problems are unlikely to occur. Therefore, the resin-coated bottle-shaped can 100 obtained by this method has excellent adhesion between the resin layer and the aluminum plate at the threaded portion, the bead portion, and the curled portion, despite the large amount of deformation of the resin-coated metal plate. There is. In addition, in this method, foreign matter is mixed in due to the peeled resin falling inside the can, and the hair-like resin is sandwiched between the sealed parts when the cap is attached after filling the contents, resulting in a decrease in sealing performance. The risk can be reduced. That is, according to the above method, a resin-coated bottle-shaped can in which the neck, shoulders, body, and bottom are integrally formed can be manufactured from the resin-coated metal plate.

Specific examples of the present invention will be described below.

(Example 1)
The resin-coated bottle-shaped can 100 described with reference to FIGS. 1 and 2 was manufactured. First, a resin-coated metal plate 100a was prepared. Specifically, 3014-H19 material having a thickness of 0.34 mm was used as an aluminum plate, and the aluminum plate was subjected to phosphoric acid chromate treatment, and a pair of chemical conversion coatings were provided on both sides thereof. The total amount of chromium contained in each of these chemical conversion films was 10 mg / m ² . Further, among these chemical conversion films, a resin layer having a thickness of 20 μm was provided on the surface located on the inner surface side of the can, and a resin layer having a thickness of 12 μm was provided on the surface located on the outer surface side. An isophthalic acid copolymerized polyethylene terephthalate resin was used for these resin layers. The ultimate viscosity of this isophthalic acid copolymer polyethylene terephthalate resin was 0.72 dL / g. The isophthalic acid copolymerized polyethylene terephthalate resin had a molar fraction of the isophthalic acid component in the dicarboxylic acid contained therein of 5% and a melting point of 241 ° C.

Using this resin-coated metal plate 100a, the resin-coated bottle-shaped can 100 was manufactured by the method described with reference to FIGS. 3 to 5. First, liquid paraffin was applied to both surfaces of the resin-coated metal plate 100a, and a disk having a diameter of 155 mm was punched out by a press. Then, this disk was drawn to obtain a structure 100b. Next, the structure 100b was redrawn twice, ironed and trimmed at the end of the opening to obtain a first intermediate 100f having an outer diameter W1 of 66 mm and a height of 165 mm.

Subsequently, hot air at 180 ° C. was blown onto the first intermediate 100f for about 30 seconds to eliminate the liquid paraffin. Then, the body 20 of the first intermediate 100f was printed by a printing machine and coated with a clear coat, and heat-treated.

The heat treatment was carried out by dividing the heating oven into first to third regions and transporting the first intermediate 100f on a conveyor in a bottom-up posture so as to pass through them in this order.
First, in the first region, heating was performed so that the surface temperature of the first intermediate 100f was 210 ° C. to promote thermosetting of the ink and the clear coat. Subsequently, in the second region, heating was performed so that the surface temperature of at least the region of the first intermediate 100f to be subjected to the necking process was 260 ° C. Finally, in the third region, unheated air was blown onto the first intermediate 100f to cool it.

Next, of the first intermediate 100f, liquid paraffin is applied to the region to be subjected to the necking process, and the opening of the first intermediate 100f is repeatedly reduced in diameter by an average of 1 mm 28 times. A neck portion 40 having an outer diameter W2 of 38 mm and a height of 28 mm was formed.

Finally, the bead portion 43 having a step of the annular recess of 1.3 mm, the screw portion 42 having a thread height of 0.7 mm, and the curl having an outer diameter W3 of 33.5 mm with respect to the neck portion 40. The part 41 was molded.

(Example 2)
A resin-coated bottle-shaped can 100 was produced in the same manner as in Example 1 except that the total amount of chromium in each chemical conversion film was 5 mg / m ^2.

(Example 3)
A resin-coated bottle-shaped can 100 was produced in the same manner as in Example 1 except that the total amount of chromium in each chemical conversion film was 50 mg / m ^2.

(Example 4)
As the isophthalic acid copolymerized polyethylene terephthalate resin, a resin-coated bottle type was used in the same manner as in Example 1 except that a resin having a molar fraction of the isophthalic acid component in the dicarboxylic acid of 2% and a melting point of 250 ° C. was used. Can 100 was manufactured.

(Example 5)
As the isophthalic acid copolymerized polyethylene terephthalate resin, a resin-coated bottle type was used in the same manner as in Example 1 except that a resin having a molar fraction of the isophthalic acid component in the dicarboxylic acid of 12% and a melting point of 223 ° C. was used. Can 100 was manufactured.

(Example 6)
A resin-coated bottle-shaped can 100 was produced in the same manner as in Example 1 except that the ultimate viscosity (IV) of the isophthalic acid copolymer polyethylene terephthalate resin was set to 0.65 dL / g.

(Example 7)
In the heat treatment, the second region of the heating oven was heated so that the surface temperature of the region of the first intermediate 100f to be subjected to the necking process was 231 ° C. A resin-coated bottle-shaped can 100 was manufactured in the same manner.

(Example 8)
In the heat treatment, the second region of the heating oven was heated so that the surface temperature of the region of the first intermediate 100f to be subjected to the necking process was 291 ° C. A resin-coated bottle-shaped can 100 was manufactured in the same manner.

(Example 9)
In the necking process, the opening of the first intermediate 100f is repeatedly reduced in diameter by an average of 1 mm 13 times to form a neck portion 40 having an outer diameter W2 of 53 mm and a height of 28 mm, and the outside of the curl portion 41. A resin-coated bottle-shaped can 100 was manufactured in the same manner as in Example 1 except that the diameter W3 was 49 mm.

(Example 10)
A resin-coated bottle-shaped can 100 was manufactured in the same manner as in Example 1 except for the following points. That is, in the necking process, the diameter reduction of 1 mm was repeated 21 times on average in the opening of the first intermediate 100f, and the outer diameter was reduced to 45 mm. Then, a second heat treatment was performed so that the surface temperature of the region to be subjected to the necking process was 260 ° C. Subsequently, liquid paraffin was applied to the area to be subjected to the necking process of this structure, and the diameter reduction process of 1 mm on average was performed 22 times for the opening having an outer diameter of 45 mm. As a result, the outer diameter W2 of the neck portion 40 is set to 28 mm, and the outer diameter W3 of the curl portion 41 is set to 24 mm.

(Comparative Example 1)
A resin-coated bottle-shaped can 100 was produced in the same manner as in Example 1 except that the total amount of chromium in each chemical conversion film was 3 mg / m ^2.

(Comparative Example 2)
A resin-coated bottle-shaped can 100 was produced in the same manner as in Example 1 except that the total amount of chromium in each chemical conversion film was 60 mg / m ^2.

(Comparative Example 3)
As the isophthalic acid copolymerized polyethylene terephthalate resin, a resin-coated bottle type was used in the same manner as in Example 1 except that a resin having a molar fraction of the isophthalic acid component in the dicarboxylic acid of 1% and a melting point of 253 ° C. was used. An attempt was made to manufacture the can 100. However, the resin layer 130 was peeled off near the opening of the first intermediate 100f. Therefore, no further molding was performed.

(Comparative Example 4)
An attempt was made to manufacture the resin-coated bottle-shaped can 100 by the same method as in Example 1 except for the following points. That is, as the isophthalic acid copolymerized polyethylene terephthalate resin, a resin having a molar fraction of the isophthalic acid component in the dicarboxylic acid of 16% and a melting point of 210 ° C. was used. Then, in the heat treatment, heating was performed in the second region of the heating oven so that the surface temperature of the region of the first intermediate 100f to be subjected to the necking process was 230 ° C. However, when the first intermediate 100f was heat-treated, crater-like rough skin was generated on the surface of the resin layer 130. Therefore, no subsequent molding was performed (Comparative Example 5).
An attempt was made to manufacture the resin-coated bottle-shaped can 100 by the same method as in Example 1 except that the ultimate viscosity (IV) of the isophthalic acid copolymer polyethylene terephthalate resin was set to 0.62 dL / g. However, when the first intermediate 100f was heat-treated, crater-like rough skin was generated on the surface of the resin layer 130. Therefore, no further molding was performed.

(Comparative Example 6)
In the heat treatment, the second region of the heating oven was heated so that the surface temperature of the region of the first intermediate 100f to be subjected to the necking process was 225 ° C. A resin-coated bottle-shaped can 100 was manufactured in the same manner.

(Comparative Example 7)
In the heat treatment, the second region of the heating oven was heated so that the surface temperature of the region of the first intermediate 100f to be subjected to the necking process was 300 ° C. An attempt was made to manufacture a resin-coated bottle-shaped can 100 by the same method. However, when the first intermediate 100f was heat-treated, crater-like rough skin was generated on the surface of the resin layer 130. Therefore, no further molding was performed.

<Evaluation>
The moldability of the opening of the resin-coated bottle-shaped can 100 obtained by the above method was evaluated. Specifically, the state of the resin layer at the opening of the first intermediate, the state of the resin layer at the threaded portion and the bead portion, and the state of the resin layer at the curled portion were visually evaluated. The resin-coated bottle-type cans in which the condition of the resin layer was good for all items were marked with "○", and the resin-coated bottle-type cans or intermediates in which even one abnormality such as peeling of the resin layer or rough skin was observed. It was evaluated as "x". The evaluation results are shown in Tables 1 and 2.

As shown in Table 1, in the resin-coated bottle-shaped can 100 according to Examples 1 to 10, the resin is formed at all the openings of the first intermediate 100f, the screw portion 42, the bead portion 43, and the curl portion 41. No problem was found in the condition of layer 130.

On the other hand, as shown in Table 2, in the resin-coated bottle type can 100 according to Comparative Examples 1 to 7, the opening, the screw portion 42 and the bead portion 43, or the curl of the first intermediate 100f is as follows. Problems were found in at least one of Part 41.
In the resin-coated bottle-shaped can 100 according to Comparative Example 1, hair-like peeling was observed in the curl portion 41, each extending in the circumferential direction and having a width of 0.3 mm and a length of several mm. ..
In the resin-coated bottle-shaped can 100 according to Comparative Example 2, extensive peeling was observed in the screw portion 42, the bead portion 43, and the curl portion 41.
In Comparative Example 3, as described above, the resin layer 130 was peeled off near the opening of the first intermediate 100f.
In Comparative Example 4, as described above, when the first intermediate 100f was heat-treated, crater-like rough skin was generated on the surface of the resin layer 130.
Also in Comparative Example 5, as described above, when the first intermediate 100f was heat-treated, crater-like rough skin was generated on the surface of the resin layer 130.
In the resin-coated bottle-shaped can 100 according to Comparative Example 6, peeling of the resin layer 130 was observed in the screw portion 42, the bead portion 43, and the curl portion 41.
In Comparative Example 7, as described above, when the first intermediate 100f was heat-treated, crater-like rough skin was generated on the surface of the resin layer 130.
As described above, in Comparative Examples 1 to 7, peeling of the resin layer 130 and rough skin were observed. On the other hand, in Examples 1 to 10, the state of the resin layer 130 was good.

Further, with respect to Examples 1 to 10 and Comparative Examples 1 to 7 described above, the plane orientation coefficients of the portions of the resin layer located at the body portion, the shoulder portion and the curl portion were measured. Specifically, in each portion, the plane orientation coefficient of the resin layer 130 constituting the inner surface of the resin-coated bottle-shaped can 100 was examined by an Abbe refractometer. The results are shown in Table 3.

As shown in Tables 1 to 3, when the resin layer was unoriented by heat treatment and then screwed, beaded and curled on the neck 40, compared with the case where the resin layer was not unoriented. The condition of the resin layer at the tip of the opening was good.

The present invention is not limited to the above embodiment, and can be variously modified at the implementation stage without departing from the gist thereof. In addition, each embodiment may be carried out in combination as appropriate, and in that case, the combined effect can be obtained. Further, the above-described embodiment includes various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed constituent requirements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the problem can be solved and the effect is obtained, the configuration in which the constituent requirements are deleted can be extracted as an invention.

10 ... bottom, 20 ... body, 30 ... shoulder, 40 ... neck, 41 ... curl, 42 ... screw, 43 ... bead, 100 ... resin-coated bottle can, 110 ... aluminum plate, 120 ... chemical conversion film , 130 ... Resin layer.

Claims (5)

An aluminum plate, a pair of chemical conversion films located on both sides thereof, each ^{containing chromium in the range of 5 to 50 mg / m 2} , and a pair of resins containing polyester and each coating the pair of chemical conversion films. The resin-coated metal plate containing the layer is subjected to drawing, one or more re-drawing and / or ironing, and trimming to form a cup-shaped first intermediate.
The opening of the first intermediate is necked to form a second intermediate having a neck, shoulders, body and bottom.
A resin-coated bottle-shaped can obtained by subjecting the neck of the second intermediate to screwing, beading, and curling. The resin has an ultimate viscosity (IV) of 0.65 dL / g or more, and the molar proportions of the isophthalic acid component and the terephthalic acid component in the dicarboxylic acid are in the range of 1.5 to 15% and 75 to 75, respectively. The resin-coated bottle-type can according to claim 1, which is an isophthalic acid copolymerized polyethylene terephthalate resin in the range of 98.5%. The resin-coated bottle-shaped can according to claim 1 or 2, wherein the ratio of the outer diameter of the body portion to the outer diameter of the curled portion obtained by performing the curling process is 1.2 or more. A resin-coated metal plate used for manufacturing a resin-coated bottle-shaped can in which the neck, shoulders, body and bottom are integrally molded and the neck has a screw portion, a bead portion and a curl portion.
Aluminum plate and
A pair of chemical conversion films located on both sides of the aluminum plate, each ^{containing chromium in the range of 5 to 50 mg / m 2.}
A resin-coated metal plate containing polyester and containing a pair of resin layers each coating the pair of chemical conversion films. An aluminum plate, a pair of chemical conversion films located on both sides thereof, each ^{containing chromium in the range of 5 to 50 mg / m 2} , and a pair of resins containing polyester and each coating the pair of chemical conversion films. A step of forming a cup-shaped first intermediate by performing drawing, one or more redrawing and / or ironing, and trimming on a resin-coated metal plate containing a layer. When,
A step of forming a second intermediate having a neck, a shoulder, a body and a bottom by performing a necking process on the opening of the first intermediate.
A step of screwing, beading, and curling the neck of the second intermediate, and
Before, after, or in the middle of the necking process, one or more regions of the region to be screwed, the region to be beaded, and the region to be curled are heated one or more times. A method for producing a resin-coated bottle-shaped can, which comprises a step of making the resin layer non-oriented in the region.

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