JPH07102417B2 - Can for can and method of manufacturing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a can for canning and a manufacturing method thereof,
More specifically, it has excellent resistance to reduced pressure deformation during the cooling process after filling the contents or during the subsequent storage,
Accordingly, the present invention relates to a can for canning a material to be used and a method for producing the can.

(Prior Art) Conventionally, as a can for cans, mainly metal, and in some cases, resin material is used. A can body with side seams is formed by joining by means such as a so-called three-piece can, which is formed by tightening both ends of the can body with the top and bottom lids, or a metal plate is drawn into a can cylinder with a bottom, deep drawing or further ironing. A so-called two-piece can, which is formed by molding and has a lid wound around the upper end of the bottomed can body, is used.

In these cans for canning, many efforts have been made to permanently reduce the thickness of the material for the purpose of reducing the material cost of the can and reducing the weight of the can itself. However, reducing the thickness of the material naturally lowers the mechanical strength of the can body, and in particular, during the cooling process after filling the contents, or during the subsequent storage or transportation, deformation of the can body due to internal decompression (deformation). It will occur remarkably. In addition, in the case of can body products, collision and the like between the cans may be unavoidable during the handling and transportation of the product, but the collision and the like may also cause deformation of the can body.

If such a deformation occurs in the can body of a can for cans, not only the appearance of the product will deteriorate and the commercial value will be impaired, but also coating defects such as pinholes, cracks, peeling, etc. on the inner and outer protective coating layers of the metal plate. It may occur and cause problems such as corrosion, metal elution, or leakage due to pitting corrosion.

Conventionally, as a means for reinforcing the can body member, it is known to form a bead in the circumferential direction and a bead in the can height direction (can axis direction) on the can body member.

(Problems to be Solved by the Invention) Forming a bead on a can body member is quite effective in preventing the above-described pressure reduction deformation, but it is considered that a circumferential bead is provided on the front surface of the can body member. However, the increase in the deformation load due to the external pressure (increase in the external pressure deformation strength) is about twice as high as that of a similar can without a bead, and even when the material is significantly thinned, the decompression deformation is completely completed. However, it is not yet fully satisfactory for the purpose of prevention.

In addition, when a bead is formed on the can body, the printed outer surface becomes uneven, which reduces the aesthetics and commercial value of the can and also causes a coating defect to appear on the inner surface of the can. There is a drawback that the value) becomes high. For this reason, beaded can bodies currently in practical use are provided with circumferential beads only in a very limited portion of the can body.

Therefore, the object of the present invention is to introduce a new reinforcing structure in place of the conventional bead, to significantly improve the deformation strength due to external pressure (or internal decompression), to have good appearance characteristics, and, in the case of a coating-formed can, to prevent the metal on the inner surface of the can An object of the present invention is to provide a can for cans in which exposure and the like are suppressed to a relatively small range, and to provide a manufacturing method thereof.

Another object of the present invention is that the outer surface of the can has a peculiar three-dimensional appearance and aesthetics based on a polyhedron, the can body can be easily gripped when drinking the contents of the can, and also has resistance to dents. The purpose is to provide cans for canning.

(Means for Solving the Problem) According to the present invention, at least a part of the can body, preferably 10% or more of the entire can body is formed with a circumferential polyhedral wall, and the polyhedral wall is a constituent unit surface, Boundary ridge lines where the constituent unit surfaces are in contact with each other and intersecting portions where the boundary ridge lines intersect with each other, the boundary ridge lines and the intersecting portions are relatively convex to the outside of the can as compared with the constituent unit surfaces, and the constituent unit surface is A method of manufacturing a can for cans that are concave inward and have a phase difference in the can axial direction arrangement adjacent to the constituent unit surface, wherein at least one of the inside or outside of the constituent unit surface or the boundary ridge is regulated. A method for producing a can for can having deformation resistance against external pressure is provided, in which the peripheral polyhedron wall is formed by forcibly engaging a forming die and a tubular can body.

According to the present invention, a circumferential polyhedron wall is formed on at least a part of the can body, and the polyhedron wall has constituent unit surfaces, boundary ridges at which the constituent unit surfaces contact each other, and intersections at which the boundary ridge lines intersect. , The boundary ridge line and the crossing portion are relatively convex to the outside of the can as compared with the constitutional unit surface, and the constitutional unit surface is recessed inward, so that the adjacent can axial direction arrangements of the constitutional unit surfaces are The crossing portions are arranged with a phase difference and are formed to have a gentle constant curvature radius (R), and the curvature radius R is expressed by the following equation with respect to the can body plate thickness t and the can body radius D. Provided is a can for can having deformation resistance to external pressure, which is characterized by satisfying t ≦ R ≦ (2/3) D.

In the can for cans of the present invention, it is preferable that the number of constituent unit planes that exist in one cycle of the can and have the same phase with respect to the can axis direction is 3 to 14.

In the canned can of the present invention, the maximum length of the structural unit surface in the axial direction of the can is L, the maximum width of the structural unit surface in the circumferential direction of the can is w, and L and w are 0.2 ≦ L / w. It is preferable to satisfy the relationship of ≦ 4.

In the can for cans of the present invention, further, from the midpoint of the line connecting the intersection points when the maximum width is taken in the can circumferential direction of the constituent unit surface or the line connecting the points on the opposing boundary ridge lines to the can body. If the distance to the center is s, the distance from the intersection or a point on the boundary ridge to the center is r, and the difference between r and s is d ₀ , the straight line in the case where the structural unit surface is not formed a can body amounts central portion of the structural unit face to the outer peripheral surface is recessed d (hereinafter, sometimes referred to the depth of the central portion), the following equation in relation to the d _0, 0.5 ≦ d It is preferably within the range of / d ₀ ≦ 2.

In the can for cans of the present invention, for example, the structural unit surface can be a quadrilateral, each side can be the boundary ridgeline, and can be curved and convex toward the inside of the can. The surface is a quadrangle, each side is the boundary ridge line, the axial cross section is bent into a substantially V shape and convex toward the inside of the can,
The constituent unit surface may further be composed of two isosceles triangles.

Furthermore, in the can for canning of the present invention, for example, the structural unit surface is a hexagon, each side is the boundary ridge line, the boundary ridge line is arranged so as not to continuously run in the axial direction of the can, and inside the can It can be curved and convex towards.

(Operation) The canned can of the present invention is one in which a circumferential polyhedral wall is formed on the can body, and this polyhedral wall has a structural unit surface and a boundary ridge line and a boundary ridge line where the structural unit surfaces contact each other. It has an intersecting portion which intersects, the boundary ridge line and the intersecting portion are convex to the outside of the can relative to the constitutional unit surface, and the constitutional unit surface is inwardly recessed, and adjacent to the constitutional unit surface. One of the features is that the can axis arrangement is arranged with a phase difference, especially with a phase difference of 1/2.

By forming the circumferential polyhedron wall composed of such constituent unit faces on the can body, the can has extremely excellent deformation resistance against external pressure, and this fact is described in the examples described later. It becomes clear by doing.

The circumferential polyhedron wall does not necessarily have to be formed on the entire surface of the can body, and if it is formed on at least 10% of the can body, sufficiently satisfactory pressure deformability is exhibited. In particular, it is preferable that the peripheral polyhedron wall is formed at the center of the can body.

Further, the above-mentioned circumferential polyhedron wall can be easily formed at any position of the can body and at a plurality of positions, but in order to impart excellent deformation resistance to the can, it is required An important factor is the number of constituent unit faces of the existing circumferential polyhedron wall. That is, although it depends on the shape of the constituent unit surface, it is generally desirable that the number n of constituent unit surfaces existing in one circumference and having the same phase with respect to the can axis direction is in the range of 3 to 14. Particularly, it is preferably 4 to 12 in the quadrilateral constitutional unit surface described later and 3 to 10 in the hexagonal constitutional unit surface. For example, an empty can resistance of a can having a can body in which a peripheral polyhedral wall having the isosceles triangular shape as the structural unit surface is formed, and a can having a can body in which such a peripheral polyhedral wall is not formed. FIG. 1 shows a diagram in which the external pressure ratio is plotted against the number n of the constituent unit surfaces. As is apparent from FIG. 1, the outer can pressure resistance ratio of the empty can decreases with increasing n, and when n exceeds 14, there is almost no improvement in the outer pressure resistance of the can. On the other hand, even when n is less than 3, it is not possible to form a sufficient multi-faceted wall surface on the can body, and since the bending on the can body surface becomes severe, the corrosion resistance of the coating film is significantly reduced and the appearance is also poor. Become.

The peripheral cylinder in which the circumferential polyhedron wall composed of the above-mentioned constitutional unit surface is formed is recessed inside the can on each constitutional unit surface,
For example, FIG. 2-B and FIG. 8 showing a side section of a can body.
As is clear from FIG. 6B, each structural unit surface appears in a state of being curved toward the inside of the can or as a V-shaped recess.
In this case, the side section of the conventional can body is a straight line in the can axis direction.

According to the present invention, each constituent unit surface is formed as described above, and the rows of constituent unit surfaces arranged in the can axis direction adjacent to each other are arranged so as to have a phase difference, particularly a phase difference of 1/2. This imparts deformation resistance to the can body. Further, by such an arrangement, since it is possible to form the circumferential polyhedral wall such that the can body surface area before forming the circumferential polyhedral wall and the can body surface area after forming the circumferential polyhedral wall are substantially equal to each other, In the obtained cans, no damage to the coating film occurs, excellent corrosion resistance is maintained, less residual stress after processing, retort sterilization and subsequent coating film adhesion and seam adhesion. Is also effectively resolved.

Further, as shown in FIGS. 12 to 14, the canned can of the present invention does not have a sharp corner portion at the intersection portion (vertex 32) where the boundary ridge portions of the constituent unit surfaces intersect with each other. ≦ R ≦ (2 /
3) D (where t is the plate thickness, R is the radius of curvature of the boundary ridges or the intersections (vertices) where the boundary ridges intersect, and D is the radius of the can barrel). It is preferred to associate to have R. Furthermore, it is preferable that the boundary ridge line portion 30 is not made to be a sharp corner portion, and has a constant curvature R in this range. If a curve is formed at the apex or along the boundary line in this range, the adhesion of the coating film applied to the surface of the processing can will be sufficiently maintained, and the stress at the boundary will be slow during molding, and damage to the film will not occur. I can't. In addition, such a bend near the boundary ridge may be one curve, that is, only one maximum bend R is near the ridge, and a plurality of bends having a plurality of constant bends R are dispersed at a plurality of places. Although there is no problem even if they exist, it is preferable that the R formed near the ridge line is within the above range.
Needless to say, R can be molded even when the structural unit surface is a quadrangle as shown in FIG.

According to the present invention, the circumferential polyhedron wall is attached to the can body by forcibly engaging the forming die that regulates at least one of the inside and the outside of the structural unit surface or the boundary ridge with the tubular can body. Can be easily formed.

(Preferred Aspects of the Invention) In the canned can of the present invention, as long as the circumferential polyhedral wall is formed in the above-described configuration, the shape of the constituent unit surface constituting the circumferential polyhedral wall is arbitrary. For example, the shape may be a quadrangle, a hexagon, or the like, and the corners may be round and almost circular, but the obtained can body has excellent deformation resistance. To give,
A quadrilateral is particularly preferable.

The specific shape of the structural unit surface will be described below.

First, as an example of the embodiment of the can for can of the present invention, the one in which the constitutional unit surface of the polyhedral wall is constituted by a quadrangle is excellent. That is, on the wall surface of the circumferential polyhedron, as shown in FIGS. 3 (a) and 3 (b), the structural unit surfaces are substantially rhombic abcd, and along the surface line connecting ac and bd (apex and apex). Along the axis connecting to and along the surface line extending in the circumferential direction) is smoothly curved, and the curved portion is convex inward.

For example, a second showing a plan sectional view of the can shown in FIG. 2-A.
In FIG. 7C, the vertices a to d of the rhombus-shaped constituent unit surface substantially project most in the radial direction, and are substantially located on the circumference of the radius o of the center o of the can body. Further, the diamond-shaped central portion (midpoint of b-d) of the curved portion of the constituent unit surface is located most inward in the radial direction. In this way, when a multifaceted wall surface is formed on the can body, which is a ridgeline that connects the vertices with each side, and the center portion of the rhombus is curved to form a valley portion,
The surface area of the can body before the polyhedron wall is formed and the surface area of the can body after the polyhedron wall is formed are kept substantially equal to each other to prevent damage to the coating film and the surface treatment layer of the can body. The above-described advantages such as effective prevention of cracks are achieved. In addition, the valley formed in the center of the structural unit surface is a smooth curved portion, which improves the reproducibility when adding a design to the external appearance, improves the appearance, and leaves the contents inside the container in the conventional cylinder. Almost no more than a can.

2-A and FIG. 4 are side views of a can in which the circumferential polyhedron wall having the rhombus-shaped constituent unit surface is provided on the can body.
As is clear from these figures, the constituent unit surfaces are formed in rows in the circumferential direction and the can axis direction,
The can axis direction arrays that are adjacent to each other are 1/1 in the can axis direction.
The can side surface is formed with a phase difference of 2. In the present invention, when such a quadrangular structural unit surface is arranged on the can body, the boundary ridge line of each structural unit surface is not arranged along the axial direction (vertical direction in the drawing) of the can. Is preferred. Particularly, in the quadrangular unit surface, such an arrangement is effective in preventing the compressive deformation in the can axis direction. The mechanism for improving the compression deformation resistance in the can axis direction is not clear, but it is thought that this is because the diamond-shaped structural unit surfaces are alternately and firmly incorporated into the side wall of the can.

Returning to FIGS. 3A and 3B again, if the length of bd in this rhombus is w and the height of ac is L, then w and L
Is the maximum width of the structural unit surface and the maximum length in the axial direction of the can.
In the present invention, the relationship between w and L affects not only the strength of the can of the present invention but also the appearance of the can. That is, the relationship between w and L is preferably 0.2 ≦ L / w ≦ 4 in order to further improve the strength of the can. As is clear from FIG. 5 showing the relationship between the L / w value and the can outer pressure resistance ratio, when L / w exceeds the above range, the appearance of the can is not so problematic, but the object of the present invention is to That is, the effect of improving the external pressure resistance of the empty can tends to decrease. On the other hand, when L / w is smaller than the above range, the outer can pressure resistance of the empty can is good, but the can body itself is easily deformed due to compression in the can axial direction, and the appearance is also deteriorated. There is a possibility that the appearance of the item may be deteriorated. Such a relationship between w and L is not limited to a quadrangular structural unit surface, and is the same for a hexagonal structural unit surface.

Further, in the can for cans of the present invention, the depth amount d of the central portion of the constitutional unit surface (that is, the center of the constitutional unit surface with respect to the straight outer surface of the can body in which such a constitutional unit surface is not formed) It is an important factor because it affects the external pressure resistance of the amount of recessed part). For example, assuming that the radius of the can body is r, the intersection points a to d of the constituent unit surfaces are located almost on the radius of the can body, although there is a slight error in molding. On the other hand, from the midpoint on the line connecting the intersection points bd in the circumferential direction (the maximum width w of the constituent unit surface in the quadrangle) to the center o of the can body.
Let s be the distance to. In this case, if the difference between the radii r and s of the can body is d ₀ = r−s as an index representing the depth of the structural unit surface, the depth d of the central portion of the structural unit surface is 0.5 ≦ d / d _0. ≤2
It is preferable to satisfy the relationship of. In the canned container shown in FIG. 2-C, the ratio of d to d ₀ (hereinafter, the depth amount ratio d / d ₀
As is clear from FIG. 6 in which the relationship between the outer pressure resistance of the can and the can outer pressure resistance is plotted, if the depth amount ratio d / d ₀ is smaller than the above range, sufficient outer pressure resistance tends not to be obtained. is there. On the other hand, if d / d ₀ is larger than the above range, buckling in the axial direction of the can easily occurs, and the difference in surface area between before and after formation of the circumferential polyhedron wall becomes large, and thus the coating force of the can of the can is increased. The adhesive strength at seams tends to decrease. Further, the appearance on printing is also deteriorated.

Also, d ₀ is closely related to the maximum width w of the structural unit surface,
w is related to the maximum axial length L described above. Therefore, the depth amount d has a close relationship with these w and L, and the permissible range also changes depending on their length. For example, in a quadrilateral structural unit plane, d ₀ = r−
s and s = rcos (π / n) and w = 2rsin (π / n), d ₀ = 1/2 ・ w (sin (π / n)) ^-1・ (1-cos (π / n ))
Therefore, it is understood that d ₀ is determined by the maximum width w and the number n of constituent unit surfaces existing in the circumferential direction. Therefore, considering the preferable range of the depth amount ratio d / d ₀ , the depth amount d is w
The larger the value of, the larger the preferable value that can be taken, and the larger the value of n, the smaller the preferable value.

Further, in the present invention, in the rhombus-shaped quadrilateral constitutional unit surface, a complete fold is formed in the central portion thereof to form a minimum constitutional unit surface as shown in FIGS. 7-A and 8-A. It can be an equilateral triangle. In this case, the structural unit surface has a V-shaped cross section, and as shown in FIG. 8-A, the isosceles triangle ABC is the minimum surface structural unit (basic surface structural unit). Each side AB at,
BC and CA are shared by two isosceles triangles. The shape and dimensions of this isosceles triangle are shown below with the length of the base BC as w and the height of the triangle as h. In the arrangement of such minimum surface structural units, the apex 2 is at the most projecting position in the radially outer direction of the can body, and the bottom side 3 is at the recessed position in the radially inner direction of the can body.
Opposite sides 4 and 4 are located at an intermediate position between them, and the polyhedron constituted by these has the opposite sides 4 and 4 as ridge lines and the bottom side 3 as valleys.

Even in such a case, the 2h / w (h = 1 / 2L) value corresponding to the L / W value in the above-mentioned rhombus-shaped structural unit surface is also preferably in the range of 0.2 to 4, and It is preferable that the number n of constituent unit planes of the same phase existing in the direction also falls within the range described above.

Further, in such a constitutional unit surface, the depth amount d of the central portion of the constitutional unit surface is substantially equal to d ₀ when a slight error in molding is ignored. And the surface area of the can body after forming the polyhedron can be made substantially equal.

Further, in order to strengthen the constituent unit surface of FIG. 8, the constituent unit surface which is a recess may be partially bent along the axial direction (FIG. 9). In such a constitutional unit surface, the depth amount d of the central portion of the constitutional unit surface can be set up to about 2d ₀ , ignoring a slight molding error, and the outer can pressure resistance Greatly improved, mechanical strength is sufficiently achieved, stress remaining in the can body after processing is remarkably small, and deterioration of coating film adhesion force and seam adhesion force with time after retort sterilization and subsequent time is effectively eliminated. It is something. Moreover, the geometrical appearance and corrosion resistance are sufficiently maintained, and the advantage that the can is easily held is achieved.

In the present invention, a mode in which the structural unit surface is hexagonal is shown in FIGS. 10 and 11. FIG. 10 shows an example when n is 8, and FIG. 11 is an example when n is 4. Also in these cases, the adjacent can axis direction arrays of the respective constituent unit surfaces are arranged with a phase difference of approximately 1/2 with respect to the can axis direction. The number n is preferably 3 to 14, and the L / w value is preferably 0.2 to 4. Further, the maximum width w of the constituent unit surface in this case is not necessarily the intersection point portion of the constituent unit surface as shown in FIG. 11, but may be the length connecting the points on the boundary ridge, and the maximum width in the axial direction. Length L
Is not necessarily the intersection of the constituent unit surfaces as shown in FIG. 10, but is the length connecting the points on the boundary ridge. Furthermore,
It is desirable that the depth amount d of the central portion of such a unit surface also satisfies the above range in relation to d ₀ as in the case of the quadrangle. Note that the relationship of w in d ₀ is as described above.
In Fig. 11, it is the maximum width that connects the points on the ridge.

According to the present invention, a metal plate or the like is formed into a tubular shape, and opposite end line portions are joined by means such as welding, adhesion, or soldering to form a side seamed can barrel, and both ends of the can barrel are used as top and bottom lids. Applicable to so-called three-piece cans that are formed by winding, and so-called two-piece cans that are formed by drawing a metal plate into a can body with a bottom and deep-drawing or further ironing, and then winding a lid around the upper end of the body with a bottom. it can.

The can for cans of the present invention is obtained by the above-mentioned manufacturing method. Specifically, for example, a can body before the lid is tightened,
It is manufactured by pressing with an inner mold and an outer mold to form the polyhedron. The inner mold used has projections corresponding to the vertices and edges of the polyhedron on the surface, while the outer mold used has projections corresponding to the valleys of the polyhedron on the surface. The polyhedron is formed by engaging the mold and the outer mold with each other through the can body.

15 to 19 are explanatory views showing a method of engraving a peripheral polyhedron whose constituent unit surface is a quadrangle or whose minimum constituent unit surface is an isosceles triangle on a can body. The can body 10 is rotated by being sandwiched between an inner mold 11 and an outer mold 12. On the surface of the inner mold 11, protrusions 13 corresponding to the vertices of the polyhedron and a diamond-shaped surface 14 inclined with respect to the peripheral surface of the can are formed.
(Fig. 15 shows only half surface) and
In FIG. 15, a curved portion (valley or bottom in the case of an isosceles triangle) 15 is shown as a line of the central cut surface. A concave portion 16 corresponding to the protrusion 13 is formed on the surface of the outer mold 12.
Further, as is apparent from FIGS. 17 and 18 showing a partially enlarged cross-sectional view of the outer die 12, a curved portion or a corner portion is provided around the recess 16.
17 are formed. For example, by using the outer mold 12 as shown in FIG. 17, it is possible to form a constitutional unit surface consisting of a recess having a curve along the line 16-17-16 on the can body. Further, by using the outer mold 12 as shown in FIG. 18, it is possible to form a structural unit surface having an isosceles triangle as a minimum unit. Further, in the use of the outer mold of FIG. 18, if the material of the outer mold 12 is an elastic body, for example, a rubber-like material, it can be used for forming a diamond-shaped constituent unit surface.

The inner mold 11 and the outer mold 12 are meshed with each other via the can body 10, and they are rotated at a synchronized speed, thereby engraving the polyhedron on the can body. Incidentally, in the case where the meshing is partly misaligned during the rotation, the inner or outer rotating shaft may be slightly moved up and down.

In this specific example, the inner mold 11 and the outer mold 12 have a smaller diameter than the can body 10, but the number of arrangements of the basic surface constituent units on the surfaces of the inner mold 11 and the outer mold 12 in the circumferential direction is Compared to that around the can body, one or more are used, but
Practically, there is no problem in forming a polyhedron. By separating the inner mold 11 and the outer mold 12, the polyhedron carved can barrel can be easily taken out. Alternatively, as shown in FIG. 19, using an outer mold 12a having an inner peripheral surface similar to the inner mold 11a having a partial outer peripheral surface having a peripheral length shorter than one half of the can body, The polyhedron can also be engraved by performing the inner mold 11a and the outer mold 12a a plurality of times with respect to the entire circumference of the can body in the positioned state. Also in this case, either one or both can be used as the elastic material.

These engraving treatments can be performed on the entire surface of the body canister, the upper end portion, the lower end portion or the central portion, and further at a plurality of locations. When neck-in processing is performed on the upper and lower ends of the can body, it is advisable to engrave the polyhedron on the portion excluding the neck-in processing portion.

Further, when the constitutional unit surface is a hexagon as shown in FIGS. 10 to 13, it is possible to use a mold corresponding to each,
Further, by making the troughs and tops of the respective molds have a predetermined radius R, FIG. 12 and FIG.
As shown in Fig. 14, the boundary can be a gently curved part.

Further, in the present invention, it is desirable to attach the constituent unit surface to the can body by a bulge method. The bulge method is a method of increasing the diameter of a can barrel by inserting a member having an expansion / contraction structure, for example, a synthetic rubber having a slit-like structure, into the can barrel and expanding it. In such a system, the outer die of the structural unit surface is arranged around the can body, the can body is inflated by the expansion / contraction member, and the can body is pressure-bonded to the outer die so that the diameter of the can body is increased and processed. The thickness of the can body can be reduced, and at the same time, the above-described structural unit surface can be formed on the can body. In forming such a structural unit surface, the neck-in processing of both end portions of the can body can be performed in advance, and the reduction in thickness for the purpose of the present invention can be facilitated. Further, the constituent unit surfaces can be formed on the can body in an accurate arrangement.

In the present invention, various surface-treated steel plates and light metal plates such as aluminum are used as the metal plate as the can body material. As the surface-treated steel sheet, one or more surface treatments such as cold-rolled steel sheet or secondary cold-rolled after annealing, zinc plating, tin plating, nickel plating, electrolytic chromic acid treatment, chromic acid treatment, etc. What is done can be used. An example of a suitable surface-treated steel sheet is an electrolytic chromic acid-treated steel sheet, which is particularly provided with a metal chromium layer of 10 to 200 mg / m ² and a chromium oxide layer of 1 to 50 mg / m ² (metal chromium conversion). This is an excellent combination of coating film adhesion and corrosion resistance. Another example of surface treated steel sheet is 0.5 to 11.2g / m
A hard tin plate having a tin plating amount of ² . This tin plate is preferably treated with chromic acid or chromic acid / phosphoric acid at 0.5 to 100 mg / m ^{2 in} terms of metal chromium.

As the light metal plate, an aluminum alloy plate is used in addition to a so-called pure aluminum plate. Aluminum alloy sheets with excellent corrosion resistance and workability are Mn: 0.2 to 1.5% by weight, M
The composition is such that g: 0.8 to 5% by weight, Zn: 0.25 to 0.3% by weight, Cu: 0.15 to 0.25% by weight, and the balance is Al. These light metal plates are also treated with chromic acid or chromic acid / chromic acid so that the chromium amount becomes 3 to 300 mg / m ^{2 in} terms of metal chromium.
It is desirable that the phosphoric acid treatment be performed.

The thickness of the metal in the body of the can varies depending on the type of metal, but in the case of surface-treated steel plate, it is 0.08 to 0.24 mm, especially
0.12 to 0.17 mm for thin steel plates and aluminum plates, 0.1
It is a feature of the present invention that the present invention can be applied to a thin aluminum plate having a thickness of 0.4 mm to 0.4 mm, particularly 0.14 mm to 0.3 mm to obtain a can having high external pressure strength.

INDUSTRIAL APPLICABILITY The present invention has a remarkable advantage that a protective coating of a resin is applied to a metal plate at any stage prior to engraving a polyhedron, and the protective coating layer is not damaged even when this is subjected to a polyhedral engraving operation. . The formation of the protective coating, by providing a protective coating,
Alternatively, it is performed by laminating a thermoplastic resin film.

As the protective coating, any protective coating composed of thermosetting and thermoplastic resins: modified epoxy coating such as phenol-epoxy coating, amino-epoxy coating, etc .: vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate Copolymer partially saponified product, vinyl chloride-vinyl acetate-maleic anhydride copolymer, epoxy-modified, epoxyamino-modified or epoxyphenol-modified vinyl or modified vinyl paint such as vinyl paint: acrylic resin paint: styrene- Synthetic rubber-based paints such as budadiene-based copolymers may be used alone or in combination of two or more.

These paints are applied in the form of an organic solvent solution such as enamel or lacquer, or in the form of an aqueous dispersion or aqueous solution, in the form of roller coating, spray coating, dip coating, electrostatic coating, electrophoretic coating, etc. Apply to the material. Of course, when the resin paint is thermosetting, the paint is baked if necessary. The protective coating is generally 2 to 30μ from the viewpoint of corrosion resistance and workability.
It is desirable to have a thickness (dry state) of m, especially 3 to 20 μm. Further, in order to improve the processability, various lubricants can be contained in the coating film.

As the thermoplastic resin film used for laminating, olefin resin film such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic ester copolymer, ionomer: polyethylene terephthalate, polybutylene Examples of the terephthalate, ethylene terephthalate / isophthalate copolymer and the like include polyester films: polyamide films such as nylon 6, nylon 6,6, nylon 11 and nylon 12: polyvinyl chloride film: polyvinylidene chloride film. These films may be unstretched or biaxially stretched.
The thickness is preferably in the range of 3 to 50 μm, particularly 5 to 40 μm. The film is laminated on the metal plate by a heat fusion method, a dry lamination method, an extrusion coating method, or the like. When the adhesion method (heat fusion property) between the film and the metal plate is poor, for example, a urethane type is used. An adhesive, an epoxy adhesive, an acid-modified olefin resin adhesive, a copolyamide adhesive, or a copolyester adhesive can be interposed.

In the case of a three-piece can, the above resin-coated plate is used, which is formed into a tubular shape, and the end line portion not covered with the resin is welded by a known electric resistance welding method, and the welding seam is coated with the resin. , The can body. Further, the end line portion can be heat-bonded with a nylon adhesive to form a can body, and when a metal tin layer is present on the end line portion, they can be joined by soldering.

Furthermore, in the case of a two-piece can, the coated metal plate is subjected to drawing or deep drawing, and the total drawing ratio is 1.1 to 4.0, particularly 1.
A bottomed can barrel in the range of 5 to 3.0 is manufactured, and a polyhedron is engraved on the bottomed can barrel. Of course, during deep drawing or subsequent to this, thinning processing by bending and stretching or Ironing can also be performed. When performing ironing, a resin coating may be provided in advance, or a resin coating may be provided on the can body after the ironing.

In the present invention, plastic can be adopted as the can body plate.

Further, in the can for canning of the present invention, by setting the L / w ratio, the number of constitutional unit surfaces n, and the depth amount d of the central portion of the constitutional unit surfaces in the appropriate ranges described above, the optimum can external pressure strength can be obtained. And metal exposure protection are provided. Furthermore, the can for cans of the present invention has a peculiar three-dimensional effect and aesthetics due to the peculiar polyhedron structure and shape, and the formation of the protrusions makes it easy to grip the can without fear of slipping, and It has many advantages such as being less likely to cause a dent even when the cans collide with each other or a foreign substance.

Example 1 An epoxy-based coating material having a thickness of 5 μm and having a thickness of 0.15 mm is applied.
The minimum constitutional unit surface shown in Fig. 3 is placed in the center of the can height on the can body of an adhesive can with an outer diameter of about 50 mm and a can height of 120 mm, which is made by stacking and joining TFS materials through a polyamide adhesive. Including 9 pieces in the circumferential direction, and 90mm with 1/2 phase difference in the can axis direction
The outer surface body was formed with a pressing tool so that the width ratio was set to 0.20 and the depth ratio d / d ₀ was set to 0.20. External pressure was applied to an empty can with both ends of the can body being wrapped with a top and bottom lid, and the outer pressure resistance of the can body was measured. As a result, a value of about 2.0 kg / cm ² was shown.

Furthermore, the ERV was measured to investigate the damage due to the processing of the inner coating film, but it was 0.01 mA, which was a sufficiently low value.

After heating and filling the can with coffee drink at 95 ℃, 30 at 120 ℃
After heat sterilization for a minute, after cooling under pressure, observe the deformed state of the can,
Then, it was stored at 37 ° C for 6 months. The degree of vacuum inside the can at 25 ° C. was 40 cmHg. After storage, the can was opened and the corrosion state of the inner surface of the can was observed and the amount of iron eluted into the contents was measured.
The results are shown in Table 1.

Examples 2, 3, 4, 5, 6, 7 Examples 2, 3, 4, 5, 6, 7 are the minimum constitutional unit planes shown in FIG. 3 whose L / w ratios are shown in Table 1. A can body having a peripheral polyhedron wall was molded in the same manner as in Example 1 except that the values shown were used. Using this can body, the outer pressure resistance ERV was measured and the pack test was conducted in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Examples 1, 2, and 3 Comparative Examples 1, 2, and 3 have the minimum constitutional unit surface shown in FIG.
A can body having a peripheral polyhedron wall was formed in the same manner as in Example 1 except that the L / w ratios were set to the values shown in Table 1. Using this can body, the outer pressure resistance and ERV were measured and the pack test was conducted in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Example 4 Comparative Example 4 does not have a peripheral polyhedron wall formed on a can body similar to that of Example 1. Using this can body, in the same manner as in Example 1, measurement of external pressure and ERV and packing.・ Tested.

The results are shown in Table 1.

Examples 8, 9, 10, 11, 12, 13 Examples 8, 9, 10, 11, 12, 13 have a TFS plate thickness of 0.12 mm.
Then, the minimum constitutional unit surfaces shown in FIG. 3 are made continuous in the circumferential direction, and the L / w ratio is 0.96 and the depth ratio d / d ₀ is the first, respectively.
A can body having a peripheral polyhedral wall was formed in the same manner as in Example 1 except that the values shown in the table were used. Using this can body, the outer pressure resistance and ERV were measured in the same manner as in Example 1. The results are shown in Table 1.

The cans were heated and filled with apple juice at 95 ° C., cooled and the deformed state of the cans was observed, and then stored at 37 ° C. for 6 months. The degree of vacuum of this can was 40 cmHg at 25 ° C. After storage
The can was opened, the corrosion state of the inner surface of the can was observed, and the amount of heat eluted into the contents was measured. The results are shown in Table 1.

Comparative Examples 5, 6, and 7 Comparative Examples 5, 6, and 7 have the minimum constitutional unit surface shown in FIG.
Nine in succession in the circumferential direction, L / w ratio 0.96, depth d / d ₀
Was formed into a can body having a circumferential polyhedron wall in the same manner as in Example 1 except that the values shown in Table 1 were used. pressure,
ERV measurements and puck tests were performed.

The results are shown in Table 1.

Examples 14, 15, 16, 17, and 18 Examples 14, 15, 16, 17, and 18 use a tin-made welded can body having a plate thickness of 0.17 mm, and L of the minimum constitutional unit surface shown in FIG. Example 1 except that the ratio of / w was 1.00, the depth ratio d / d ₀ was 0.95, and the number of the minimum surface constitutional units in the circumferential direction was set to the values shown in Table 1, respectively. A can body having a peripheral polyhedron wall was formed in the same manner as in. Using this can body, the outer pressure resistance and ERV were measured and the pack test was conducted in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Examples 8 and 9 Comparative Examples 8 and 9 are the same as Example 14 except that the number of consecutive minimum constituent unit surfaces shown in FIG. 3 in the circumferential direction is set to the value shown in Table 1, respectively. Then, a can body having a circumferential polyhedron wall was formed. The outer pressure resistance and ERV measurements and the pack test were conducted in the same manner as in Example 1 using this can body.

The results are shown in Table 1.

Example 19 An outer diameter of about 50, which is obtained by superposing and joining a TFS material having a plate thickness of 0.15 mm coated with an epoxy-based paint via a polyamide-based adhesive.
As shown in Fig. 11, a can body of an adhesive can with a height of 120 mm and a can height of 120 mm includes a hexagonal unit surface including the center of the can height. The outer surface body was formed with a pressing tool so that the L / w ratio was 1.00 and the depth ratio d / d ₀ was 0.90 with a / 2 phase difference of 60 mm width.

In the same manner as in Example 1 using this can body, the outer pressure resistance, RE
V measurements and puck tests were performed.

The results are shown in Table 1.

Example 20 An outer diameter of about 50 formed by superposing and joining a TFS material having a plate thickness of 0.15 mm coated with an epoxy-based paint via a polyamide-based adhesive agent
mm, 120 mm can height, the can body of the can, as shown in Fig. 13, includes the unit surface, including the center of the can height, 4 in the circumferential direction, and 1/2 in the can axial direction. Phase difference 60mm width, L / w
The outer surface body was formed by using a pressing tool so that the ratio of 1.0 and the depth ratio d / d ₀ were 0.90.

Using this can body, in the same manner as in Example 1, the outer pressure resistance, ERV
Was measured and a pack test was performed.

The results are shown in Table 1.

Comparative Example 10 Comparative Example 10 is a can body having a circumferential polyhedral wall in the same manner as in Example 1 except that two minimum constituent unit surfaces shown in FIG. 11 are continuously formed in the circumferential direction (n = 2). Was molded. Using this can body, the outer pressure resistance ERV was measured and the pack test was conducted in the same manner as in Example 1.

The results are shown in Table 1.

From Examples 1 to 7 and Comparative Examples 1 to 4, L / w is 0.2 or more,
If it is 4.0 or less, it is superior in external pressure resistance, buckling resistance of the can during heat sterilization, and corrosion resistance after long-term storage to those having other values or those not having the peripheral polyhedral wall formed. I understand.

From Examples 8 to 9 and Comparative Examples 5 to 7, when d / d ₀ or more and 2 or less, the external pressure resistance, the buckling resistance of the can during heat sterilization, and the corrosion resistance after long-term storage are excellent. I understand.

From Example 1, Examples 14 to 18 and Comparative Examples 8 to 10, the number n of the smallest constitutional unit surfaces in the circumferential direction is 3 or more, 14
It can be seen that when it is below, the external pressure resistance, the buckling resistance of the can during heat sterilization, and the corrosion resistance after long-term storage are excellent.

From Examples 1 to 18, Examples 19 and 20, and Comparative Example 10, the shape of the minimum constitutional unit surface may be a quadrangle, a hexagon, or an ellipse, and the adjacent can axis direction arrangement of the constitutional unit surfaces is It can be seen that the arrangement with a phase difference is effective for the external pressure resistance.

Examples 21, 22, 23, 24, 25 Examples 21, 22, 23, 24, 25 are adhesive cans having an outer diameter of 53 mm, and the radii of curvature R of the vertices where the boundary ridgelines of the respective constituent unit surfaces intersect are 1.5, respectively. A can body having a peripheral polyhedron was formed in the same manner as in Example 4 except that the peripheral polyhedron was formed using a pressing tool so that the thickness was 5.5, 9.5, 14.5, and 17.0 mm. ERV for each can to check for damage due to processing of the inner coating
Was measured. The results are shown in Table 2.

Also, each can was heated and filled with a lactic acid beverage at 95 ° C., cooled to room temperature, and then the deformed state of the can was observed. Then, after storing at 37 ° C. for 1 month, the can was opened and the corrosion state of the inner surface of the can was observed. The results are shown in Table 2.

Comparative Examples 11, 12, and 13 Comparative Examples 11, 12, and 13 are adhesive cans having an outer diameter of 53 mm, and the radii of curvature R of the vertices at which the boundary ridgelines of the constituent unit surfaces intersect are 1 respectively.
A can body having a peripheral polyhedron was formed in the same manner as in Example 4 except that the peripheral polyhedron was formed to have a size of 9.0, 25.5, and 0.13 mm using a pressing tool. The ERV of each can was measured to examine the damage due to the processing of the inner coating film. The results are shown in Table 2.

Also, each can was heated and filled with a lactic acid beverage at 95 ° C., cooled to room temperature, and then the deformed state of the can was observed. Then, after storing at 37 ° C. for 1 month, the can was opened and the corrosion state of the inner surface of the can was observed. The results are shown in Table 2.

From Examples 21 to 25 in Table 2, when the radius of curvature R of the apex where the boundary ridges intersect each other satisfies the condition of t ≦ R ≦ (2/3) D, the excellent deformation resistance of the can of the present invention is obtained. In addition to sex
Furthermore, it can be seen that in the can, the corrosion resistance near the apex where the boundary ridgelines of the circumferential polyhedron intersect each other is improved.

From Comparative Examples 11 and 12 in Table 2, when the radius of curvature R of the apex where the boundary ridges intersect with each other exceeds (2/3) D, the corrosion resistance near the apex decreases, resulting in the deformation resistance of the can as well. It can be seen that it will decrease. Further, it can be seen from Comparative Example 13 in Table 2 that even when the radius of curvature R of the apex where the boundary ridges intersect is less than t, the corrosion resistance near the apex is reduced.

(Effect of the Invention) According to the method for producing a can for cans of the present invention, a circumferential polyhedral wall is formed on the can body, and the polyhedral wall is a constituent unit surface, and boundary ridge lines and boundary ridge lines between the constituent unit surfaces are in contact with each other. And the boundary ridge line and the intersecting portion are convex toward the outside of the can relative to the constituent unit surface, and the constituent unit surface is inwardly concave, and the constituent unit surface Of the can barrel, in which the adjacent can axial direction arrays are arranged with a phase difference,
The can body can be easily manufactured by forcibly engaging the forming die that regulates at least one of the inside or the outside of the structural unit surface or the boundary ridge with the tubular can body, and the obtained can body has an external pressure deformation strength. It is remarkably superior to the conventional bead reinforced structure, and the resulting can body has excellent coating film adhesion and corrosion resistance.

Further, the intersecting portion where the boundary ridge lines intersect is formed to have a gentle constant curvature radius (R), and the curvature radius R is specified within a certain range with respect to the can body plate thickness t and the can body radius D. By doing so, the optimum combination of corrosion resistance and deformation resistance can be obtained.

This can for cans is particularly excellent in coating film adhesion and seam adhesion, does not damage the coating film, maintains corrosion resistance, and has relatively little residual stress in the can body after processing. Moreover, the retort sterilization and the subsequent deterioration of the coating film adhesion force and the seam adhesion force with the passage of time can be effectively eliminated, and the cost can be significantly reduced by reducing the thickness of the can. In addition, the can for cans has good reproducibility in terms of appearance when applied with a design, and has excellent appearance characteristics.

[Brief description of drawings]

FIG. 1 is a characteristic diagram when the can outer canning pressure resistance ratio (ratio of the canning outer pressure with and without the structural unit surface) and the n value are changed, 2-A, 2-B, and 2-C are side views, vertical cross-sections, and horizontal cross-sections for explaining the quadrilateral of the can of the present invention as a unit surface. Figures (a) and (b) are a plan view and a sectional view of a structural unit surface formed on the side surface of a can for can according to the present invention, and Fig. 4 shows the structural unit surface of Fig. 2 only in the central portion. Side view of a can for canning, Fig. 5 is a characteristic diagram of the outer pressure resistance ratio of an empty can when the L / w value of the can for canning is changed, and Fig. 6 is the depth of the constituent unit surface of the can for canning. A characteristic diagram of the ratio d / d ₀ and the resistance against external pressure of the empty can, FIG. 7 is an explanatory view of an isosceles triangular unit surface of another aspect formed on the can body of the can for can according to the present invention, -A and FIG. 8-B are the seventh Fig. 9 is a side view and a longitudinal sectional view for explaining another mode of Fig. 9, Fig. 9 is a side view of a can for can of another mode in which the structural unit surface of Fig. 8 is further changed, Fig. 10 and Fig. 11 respectively. Is a partial side view of a can for can according to the present invention having a hexagonal structural unit surface, and FIGS. 12 and 13 are partial side views of a can for can according to the present invention having a hexagonal structural unit surface having R, FIG. 14 is a partial side view of a can for canning according to the present invention having a quadrilateral structural unit surface having R, and FIGS. 15 and 16 are sectional views for explaining a method of engraving a polyhedron on a can body. FIG. 17 is a perspective view, FIG. 17 and FIG. 18 are cross-sectional views of the abutting portion of the constituent unit surface of the outer die in FIG. 14, and FIG. It is a figure. 1: structural unit surface, 2: apex, 3: bottom side, 4: boundary ridge line, 10: can barrel, 11: inner mold, 12: outer mold, 20: structural unit surface, 30: boundary ridge line,
32: Vertex.

Claims (10)

[Claims] 1. A circumferential polyhedron wall is formed on at least a part of a can body, and the polyhedron wall has structural unit surfaces, a boundary ridge line where the structural unit surfaces are in contact with each other, and an intersection portion where the boundary ridge lines intersect each other. The boundary ridgeline and the intersecting portion are relatively convex to the outside of the can as compared with the constitutional unit surface, the constitutional unit surface is concave inward, and the adjacent can axial direction arrangement of the constitutional unit surface has a phase difference. A method for manufacturing a can for a can, which comprises the above-mentioned circumferential shape by forcibly engaging a forming die that regulates at least one of the inside or outside of the unit surface or boundary ridge with a cylindrical can body. A method for producing a can for cans having deformation resistance against external pressure, characterized by forming a polyhedral wall. 2. A circumferential polyhedron wall is formed on at least a part of a can body, and the polyhedron wall has structural unit surfaces, a boundary ridge line where the structural unit surfaces are in contact with each other, and an intersection portion where the boundary ridge lines intersect each other. The boundary ridgeline and the intersecting portion are relatively convex to the outside of the can as compared with the constitutional unit surface, and the constitutional unit surface is inwardly concave, and the adjacent can axial direction arrangement of the constitutional unit surface has a phase difference. And the intersecting portion is formed to have a gentle and constant radius of curvature (R), and the radius of curvature R is expressed by the following equation t ≦ T can radius D with respect to the can body plate thickness t and the can body radius D. A can for cans having deformation resistance to external pressure, characterized in that R ≦ (2/3) D is satisfied. 3. A can for canning according to claim 2, wherein at least 10% or more of said peripheral polyhedron wall is formed on the entire surface of said can body. 4. The number of constituent unit surfaces which are in the same phase with respect to the direction of the can axis existing around one circumference of the can body is 3 to 14, and the number of constituent unit surfaces is 3 to 14. Can for. 5. The maximum length of the constituent unit surface in the can axis direction is L
The maximum width of the structural unit surface in the circumferential direction of the can is defined as w, and the L and w satisfy the relation of 0.2 ≦ L / w ≦ 4. Canned cans as described. 6. The distance from the midpoint of the line connecting the intersections when the maximum width is taken in the can circumferential direction of the constituent unit surface or the line connecting the points on the opposing boundary ridges to the center of the can body. s, the distance from the intersection or a point on the boundary ridge to the center is r, and the difference between r and s is d ₀ , the straight outer surface of the can body in the case where the constituent unit surface is not formed In contrast, the amount d of depression of the central portion of the structural unit surface is
The can for canning according to any one of claims 2 to 5, wherein the relationship with d ₀ satisfies the following formula. 0.5 ≦ d / d ₀ ≦ 2 7. The constitutional unit surface is a quadrilateral, each side is the boundary ridgeline, and the constitutional unit surface is arranged so that the boundary ridgeline does not extend in the axial direction of the can, and is curved toward the inside of the can. 7. The second to sixth aspects are characterized in that they are convex.
A can for canning according to any one of items. 8. The structural unit surface is a quadrangle, each side is the boundary ridge, and the axial cross section is bent into a substantially V shape to be convex toward the inside of the can. The second aspect of the present invention is characterized by being composed of an equilateral triangle.
Item 8. A can for canning according to any one of Items 6 to 6. 9. The constitutional unit surface is hexagonal, each side is the boundary ridge line, and is curved and convex toward the inside of the can. The can for canning according to any of the above. 10. A boundary ridge portion where the constituent unit surfaces are in contact with each other is formed to have a gentle constant curvature radius (R), and the curvature radius R is relative to the can body plate thickness t and the can body radius D. The can for canning according to claim 7, wherein t ≦ R ≦ (2/3) D is satisfied.