JP2024009521A - Metal cup with stackability and decorativeness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal cup with stackability and decorativeness.

SOLUTION: A stackable metal cup 1 has: a body part 3 which is in a hollow shape having its upper part opened and inclined from the top to bottom so that an upper-end inner diameter D is larger than a lower-end outer diameter d; and a bottom part 7 which comprises a ground part 5 connecting with the lower end of the body part via a curvature part. A resin-coating layer 22 is provided over the entire outer surface or inner surface with a colored polyester coating 21 interposed.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a metal cup that has stackability so that it can be stacked and stored, and further relates to a metal cup that also has decorative properties.

Conventionally, cup-shaped containers used for drinking and the like have been widely made of paper or plastic. This is because vessels molded from these materials are lightweight and easy to mold, making them inexpensive and suitable for disposable use. However, in recent years, metal cups have attracted attention from environmental viewpoints such as resource depletion and garbage problems. This is because metal cups have higher strength and durability than paper or plastic cups, are suitable for repeated use, and can significantly reduce resource depletion and waste generation.

By the way, such metal cups are often used for drinking alcoholic beverages such as beer, and have a size of about the size of a so-called small mug to a large mug, and at the same time, they do not have stackability. In order to achieve this, the inner diameter of the opening at the top end is set larger than the outer diameter at the bottom. A metal cup having such a configuration has two to three steps formed in the middle of the body, as shown in Patent Document 1, for example. Further, as described in Patent Document 2, in order to make the inner diameter of the opening at the upper end larger than the outer diameter at the bottom, the body can be formed into a tapered inclined wall, but even in this case, for example, Approximately two steps are formed on the body wall (slanted wall). In any type of metal cup, when a plurality of cups are stacked, the body walls are prevented from coming into close contact with each other, so that the stacked metal cups can be taken in and out smoothly.

That is, in the metal cups of Patent Documents 1 and 2, a step is formed on the body wall, so that the outer surface of the body wall of the stacked upper cup and the body of the lower cup holding this are separated. A gap is formed between the cup and the inner surface of the wall, and the area where the two come into close contact is greatly reduced, making it easier not only to stack the cups but also to pull out the stacked cups.

Special table 2015-506842 publication JP 2021-155121 Publication

However, metal cups having stackability as described above have a drawback of poor decorativeness. That is, in order to ensure stackability, a protrusion such as a step or a bead is formed horizontally on the outer surface of the body of the cup, which greatly limits the printing range. Furthermore, when a cylindrical metal cylinder is formed, the outer surface is printed, and the cylinder is re-drawn from the bottom end to form a cup shape with a large top diameter and a small bottom diameter, metal Since the sloped part of the side wall of the cylinder (the sloped part with a shape narrowed toward the bottom end) becomes a non-decorated surface that is not printed, the printing surface is still limited and the decorativeness is low. ing.

In addition, with the development of metal processing technology in recent years, the drawing and ironing process has made it possible to make metal cans, such as aluminum cans, extremely thin, and metal cups have also become thinner, making the cups lighter and lighter. Resource saving has been achieved. However, although such thinning of the body wall brings about the above-mentioned advantages, it also brings about a decrease in strength, which causes the problem that the metal cup becomes easily deformed and stackability is impaired. In order to prevent such a decrease in strength, it is preferable to form irregularities on the outer surface of the body of the cup, but such irregularities also limit the printing range and reduce decorative properties.

Therefore, an object of the present invention is to provide a metal cup with stackability and decorativeness.

According to the present invention, the body has a hollow shape with an open top, the inner diameter of the upper end is larger than the outer diameter of the lower end, and the body is inclined from the top to the bottom; A stackable metal cup having a bottom portion having a grounding portion connected to the lower end via a curvature portion,
A stackable metal cup is provided, characterized in that a resin coating layer is provided over the entire outer and/or inner surface via a colored polyester coating.

In the stackable metal cup of the present invention, the following aspects are preferably adopted.
(1) When viewed from the side, on the outer surface of the body, there are inflection points formed by changes in the inclination angle with respect to the vertical plane, in each of the upper region A1 including the upper end and the lower region A2 including the ground contact portion. Contains at least one part α.
(2) The height of the upper region A1 is in the range of 70% to 100%, and the height of the lower region A2 is 40% or less, assuming that the height H from the ground contact part to the upper end is 100%. Must be within the range.
(3) The inclination angle difference Δθ defining the inflection point portion α is 25 degrees or less.
(4) A plurality of inflection point portions α where the inclination angle of the body portion changes are formed in an intermediate region A3 between the upper region A1 and the lower region A2, and are formed in the intermediate region A3. The inclination angle differences Δθ that define the inflection point portion α are all smaller than the inclination angle differences Δθ that define the inflection point portion α existing in the upper region A1 and the lower region A2.
(5) The thickness of the polyester coating film is 10 μm or less.
(6) The polyester coating film contains any one of a phenol resin, an amino resin, and an isocyanate resin as a curing agent resin component.

In the metal cup of the present invention, the inner diameter of the upper end of the body is set larger than the outer diameter of the lower end, which ensures stackability, but a particularly important feature is that the entire outer surface , a resin coating layer is provided through a colored polyester coating. In other words, since the base of the resin coating layer is colored, the metallic color is hidden on the entire outer and/or inner surface, making it possible to visually recognize the color of the base polyester coating, greatly improving the decorative properties. . For example, the torso is colored from top to bottom, and the bottom is also colored. Furthermore, a major feature of the metal cup of the present invention is that when the entire inner surface is colored, even the curled portion is colored.

Therefore, in the present invention, decorative properties are ensured no matter what form of protrusion (bead) or step is formed on the outer and/or inner surface of the body.

In the metal cup of the present invention, by forming an inflection point portion α caused by a change in the inclination angle of the body wall (that is, a difference in inclination angle), the body wall is made more resistant to pressure from the circumferential direction and shaped. It is preferable to suppress the change.

By forming at least one such inflection point portion α in the upper region A1 (region with a height of 70% to 100%), the upper end of the metal cup becomes difficult to deform. Even when deformed, the shape of the upper end of the opening does not deform, so there is an advantage that stackability is not impaired.

In addition, by forming at least one inflection point portion α as described above in the lower region A2 (region with a height of 40% or less), the lower region A2 is also less likely to deform, and the upper end portion of the opening In addition, deformation of the lower end portion is also less likely to occur. In short, the upper and lower shapes, which are most important for ensuring stackability, are difficult to deform, so stackability is ensured more stably. This is achieved without sacrificing sexuality.

Furthermore, in the present invention, the most preferred form is that a plurality of inflection point portions α as described above are also formed in the intermediate region A3 between the upper region A1 and the lower region A2; Optimally, the angular difference Δθ defining the inflection point portion α is smaller than the angular difference Δθ between the upper region A1 and the lower region A2, and is, for example, a level difference that can be slightly felt by touch. That is, this intermediate region A3 is a part where the metal cup is frequently held by hand. Since this region is the part where deformation occurs most frequently, it is better to provide many inflection point parts α, but it is better to provide many inflection point parts α. The inflection points are large enough to be clearly recognized as steps, and if the number of inflection points that are recognized as steps increases, the smoothness of the body wall will be impaired, for example, making it difficult to print or attach labels. Sexuality etc. will be lost. Furthermore, when the cups are stacked, the stacked cups may become loose and the stability during stacking may be impaired. Therefore, in this intermediate region A3, it is optimal to form an inflection point portion α with a slight angular difference that is difficult to recognize as a step, and to improve the strength while preventing the above-mentioned disadvantages.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side sectional view and a partial sectional view of a body of a metal cup according to the present invention. FIG. 2 is an enlarged view showing a side cross section of a metal wall forming the metal cup of the present invention.

<Form of metal cup>
First, a preferred form of the metal cup of the present invention will be explained.
The metal cup of the invention, generally designated 1 in FIG. 1, comprises a body 3 and a bottom 7 with a ground contact 5 . A curled portion 9 is usually formed at the upper end of the body portion 3 to prevent sharp edges from being exposed to the outside. Further, the lower end of the body portion 3 is connected to the ground contact portion 5 via the curvature portion R.
The bottom portion 7 usually has a flat shape located above the ground contact portion 5, that is, a so-called raised bottom shape, but the bottom portion 7 may have a dome-shaped concave shape in the center.
The body part 3 forms a hollow part 10 which is open at the upper end, and this hollow part 10 is closed by the bottom part 7, and is adapted to contain a liquid such as a drink depending on the purpose.

In the metal cup 1 described above, in order to ensure stackability, the opening diameter D at the upper end of the hollow space (or hollow opening) 10 (i.e., the inner diameter at the upper end of the body 3) is larger than the outer diameter d at the lower end. It slopes downward.

The metal that is the constituent material of the metal cup 1 may be various metals or alloys, such as aluminum, copper, iron, alloys containing these metals, and tin-plated steel sheets such as tinplate. It may be a surface-treated steel plate such as an aluminum plate subjected to chemical conversion treatment. Generally, steel, stainless steel, aluminum, or an aluminum alloy is suitable, and aluminum or an alloy thereof is particularly suitable from the viewpoint of light weight and workability. That is, the metal cup 1 is molded using the thin metal blank plate described above, and the form of the blank plate, molding means, etc. will be explained in detail in the section on decoration, which will be described later.

In the metal cup 1 as described above, the thickness of the center portion of the bottom 7 corresponds to the thickness of the blank plate used for molding the cup 1, and although it varies depending on the use of the cup 1, it is generally 0.10 to 0. It has a thickness of 50 mm, and the thickness of the body 3 and the height H of the cup 1 (height from the grounding part 5 to the top of the body 3) vary depending on the degree of squeezing, and the squeezing rate can be gradually increased. As the ironing process is performed in multiple stages, the body 3 becomes thinner and the height H becomes higher. Particularly in recent years, this thinning has become remarkable, and in order to cope with such thinning, the metal cup 1 of the present invention has the following form.

As shown in Fig. 1, this body part 3 has many places where the inclination angle (angle with respect to the vertical plane) changes, and the inflection point is caused by the angular difference Δθ of the inclination angle. α occurs. When this angular difference Δθ is large, this inflection point portion α is clearly visible as a step. Such an inflection point portion α exhibits resistance to stress from the circumferential outer surface of the body portion 3 of the metal cup 1, and effectively suppresses deformation of the body portion 3.
In addition, in the following description, when it is described as an inclination angle, it means an angle with respect to a vertical plane unless otherwise specified.

For example, in the example shown in Figure 1, the reference hanging wall has an inclination angle of less than 2 degrees, in particular less than 1 degree, preferably less than 0.5 degrees (i.e. the inclination angle is approximately zero) with respect to the vertical plane. 3a and inclined walls 3b having an angular difference Δθ from the reference hanging wall 3a are arranged in a row alternately to form a plurality of inflection point portions α. In this case, the inclination angle of the reference hanging wall 3a is smaller than the angular difference Δθ. Note that the angular difference Δθ (that is, the angular difference with the reference hanging wall 3a) is within a range of 25 degrees or less, and the angular differences Δθ forming the plurality of inflection point portions α may be uniformly the same, They may have different values, provided that the angle of inclination is 25 degrees or less.

In the present invention, the above-mentioned inclination angle with respect to the vertical plane of the body 3 and the angle difference Δθ with the vertical wall 3a are determined under the condition that the opening diameter D at the upper end of the hollow part 10 is larger than the outer diameter d at the lower end. However, if it is set larger than necessary, the outer diameter d of the lower end becomes smaller than necessary, or the number of inflection point parts α (steps) is limited. Further, the flatness of the outer surface of the body portion 3 is impaired, and printability and label application properties are impaired. From this point of view, the inclination angle (angle with respect to the vertical plane) of the body 3 is set to be 7 degrees or less, and the angular difference Δθ is set to 5 degrees or less, particularly 1 degree or less, and most preferably 0.5 degrees or less. It is preferable to do so. Thereby, the number of inflection point portions α can be appropriately increased. For example, it is not desirable to form the inflection point portion by a horizontally recessed portion.

The metal cup 1 including the body 3 having the inflection point portion α as described above has an upper region A1 whose height is above 70% to 100% when the height H of the body 3 is 100%. , a lower region A2 whose height is 40% or less of H, and an intermediate region A3 between these regions A1 and A2. In the present invention, inflection point portions α due to the angle difference Δθ as described above are distributed in each of these regions.

First, in the upper region A1, at least one, preferably two to four inflection point portions α caused by the angular difference Δθ in the inclination angle of the body portion 3 are formed. Thereby, the strength of the upper region A1 can be increased, deformation of the upper end portion of the hollow opening 10 can be effectively suppressed, and stackability can be ensured.

Further, in the lower region A2, it is desirable to form at least one, preferably 3 to 5 inflection point portions α caused by the angular difference Δθ in the inclination angle of the body portion 3. Thereby, the strength of the lower region A2 as well as the upper region A1 can be increased, and deformation of the upper end portion and the lower end portion of the hollow opening 10 can be effectively suppressed, and stackability can be more reliably ensured. . That is, when stacking, not only can the metal cup 1 be accepted, but also the metal cup 1 can be inserted smoothly.

Incidentally, the angular difference Δθ between the inclination angles between the upper region A1 and the lower region A2 is set to 25 degrees or less, as described above.

In addition, in FIG. 1, reference hanging walls 3a having a very small inclination angle with respect to a vertical plane (or having an inclination angle of zero) and inclined walls 3b having an angular difference Δθ with respect to the reference hanging wall 3a are arranged in an alternating sequence. However, as long as the angle difference Δθ is 25 degrees or less, a wall with a different inclination angle (for example, a tapered wall with a larger inclination angle than the inclined wall 3b) is formed between the reference hanging wall 3a and the inclined wall 3b. may have been done. In this case, an inflection point portion α is also formed between the tapered wall and the inclined wall 3b and between the tapered wall and the reference hanging wall 3a.

Furthermore, in the present invention, it is optimal to form at least 4, preferably 6 to 10 inflection point portions α caused by the angular difference Δθ in the inclination angles also in the intermediate region A3. That is, the metal cup 1 is most often used for drinking alcoholic beverages such as beer. Therefore, the intermediate region A3 is gripped most strongly and easily deformed. Therefore, in order to strengthen this portion, it is preferable to form the above number of inflection point portions α. In addition, since the intermediate region A3 has a large area, if this part is flat, when the metal cups 1 are stacked, the area where the upper and lower cups 1 that are overlapped will be in close contact will be large, which will reduce the stackability. may decrease. In order to avoid such deterioration in stackability, it is preferable to form a large number of inflection point portions α.

By the way, referring also to FIG. 2 showing the intermediate region A3, the intermediate region A3 has a large area and is located at the center of the metal cup 1. For this reason, this portion is very frequently printed or affixed with labels. Therefore, high smoothness is required in this region. From this point of view, it is preferable that the angular difference Δθ of the inclination angle in the intermediate region A3 is formed smaller than that in the upper region A1 and the lower region A2, and the plurality of angular differences Δθ are all 5 degrees. It is particularly desirable that the angle is below 1 degree, most preferably below 0.5 degree. As can be understood from FIG. 2, the inflection point part α due to such a small angular difference shows a slight level difference that can be recognized by touch, and in terms of high strength, it is difficult to It is inferior to the inflection point portion α in area A2. However, even the inflection point portion α due to such a small angular difference is sufficient to ensure stackability. This is the most preferable embodiment because it is possible to increase the strength to some extent by reducing the interval between the portions α).

As mentioned above, the metal cup 1 of the present invention has a height H in the range of 90 to 150 mm, and the upper end of the opening Most preferably, the inner diameter is in the range of 70 to 90 mm.
Further, in the above example, the curled portion 7 is formed at the upper end, but instead of the curled portion 7, a horizontal flange or the like is formed, and after storing food, etc., a lid material is provided by heat sealing etc. and used. You can also do that. In this case, it is advantageous to store the used cup when it is to be used repeatedly.

<About decoration>
The metal cup 1 of the present invention having the above-mentioned configuration has the entire outer surface and/or inner surface colored, and exhibits excellent decorative properties. That is, not only is the body portion 3 colored from the upper end to the lower end, but the entire metal cup 1 including the bottom portion 7 and the curled portion 9 is colored in the same color as the body portion 3.

Specifically, with reference to FIG. 2 showing an enlarged side cross section of the metal wall forming the metal cup 1 formed in the above-described form, the outer surface of the metal wall 20 is colored. A polyester coating film 21 is formed over the entire surface, and a resin coating layer 22 is provided via this polyester coating film 21. On the other hand, although the inner surface of the metal wall 20 is not particularly limited, it is usually made to have corrosion resistance, to suppress surface roughness during severe forming processing, and to prevent metal corrosion. , a thermoplastic or curable resin coating layer is provided via the primer coating film 23.

In the present invention, a colored polyester coating film 21 and a resin layer 22 are formed on one surface of a metal base plate used for molding the metal cup 1 (i.e., the surface that becomes the outer surface of the cup 1), and the other surface is coated with a colored polyester coating 21 and a resin layer 22. A primer coating film 23 and a resin coating layer 24 are formed on the surface to obtain a laminate plate, and this laminate plate is used as a molding material and subjected to predetermined plastic processing to have the form shown in FIG. 1, and A metal cup 1 whose entire outer surface is colored can be obtained. Specifically, the above laminate board is punched and drawn, the bottom is processed almost simultaneously, and then the trimming part is heat treated (to prevent film peeling), and the trimming and curling processes are performed to create an almost straight body shape. A cylindrical inner tool having a diameter smaller than the inner diameter of the bottomed can is placed inside the can, and a ring having an inclined molded surface is placed on the bottom side of the bottomed can. Place the shaped outer tool. The inclined forming surface of the outer tool is applied from the bottom side to form the inclined wall 3b that forms the side wall of the bottomed can in an inclined shape, and this process is repeated to form a structure having the form shown in FIG. 1 and the outer surface and/or inner surface. It is possible to obtain a metal cup 1 which is entirely colored.
Other processing methods include punching and drawing the laminate plate to form a bottomed can body with an almost straight body shape, a trimming process, and curling the tip of the bottomed can body. After that, the metal cup 1 can be obtained by expanding the diameter of the side wall using a diameter expanding die.

In the present invention, as the coating composition for forming the colored polyester coating film 21, for example, the polyester coating composition disclosed in WO2020/184200 is preferably used.
This coating composition contains a known polyester as a base resin component, and further contains a curing agent resin component and a colorant, and these components are dispersed in an organic solvent. Details of the polyester and each component used in combination with the polyester are as described in WO2020/184200 above.

For example, the curing agent resin has a functional group that reacts with the OH group or COOH group of the polyester used as the base resin, and examples thereof include curing agents made of phenol resin, isocyanate resin, amino resin, etc. can. These resins may be used alone or in combination of two or more, and are usually used in an amount of 5 to 43 parts by weight, particularly 8 to 18 parts by weight, per 100 parts by weight of polyester.
Among the above curing agents, resol-type phenolic resins and amino resins can be suitably used, but when phenolic resins are used, the coating film formed becomes yellow, so the original color of the colorant is For this purpose, it is most suitable to use an amino resin.

Colorants include organic pigments such as azo pigments, phthalocyanine pigments, condensed polycyclic pigments, and dyeing lake pigments, inorganic pigments such as oxides, silicates, and ferrocyan compounds, and polarized pearl pigments. Depending on the desired external design of the metal cup 1, one or more suitable pigments can be used, such as bright pigments such as aluminum bright pigments, mica bright pigments, and glass bright pigments. . In order to adjust the color and physical properties, white pigments such as titanium oxide and zinc oxide, and extender pigments such as calcium carbonate can also be blended.

The above coloring agent is used in an amount of 20 parts by mass or less based on 100 parts by mass of the total resin solid content (total of polyester resin and curing agent) of the coating composition, and in an amount sufficient to hide the color of the underlying metal. , especially in an amount of 1 part by weight or more, particularly preferably in an amount of 1 to 10 parts by weight. If the amount of colorant is larger than the above range, the processing adhesion between the metal plate and the resin coating will decrease, and the color difference between the body and the bottom, which has a lower degree of processing than the body, will decrease. may become clear. Furthermore, the stability of the coating composition may decrease, and during long-term storage, precipitation, separation, and viscosity changes may occur, resulting in a decrease in coating properties.

The organic solvent is preferably one that has a plasticizing effect on the polyester resin and has amphiphilic properties, such as ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, and isoamyl alcohol. , sec-amyl alcohol, tert-amyl alcohol, n-hexanol, cyclohexanol, and other alcohols; methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, and other ketones; tetrahydrofuran, dioxane, 1,3-dioxolane, and other cyclic alcohols; Ethers, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene Glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, glycol derivatives such as propylene glycol methyl ether acetate, 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, acetoacetic acid Ethyl, etc. can be used.

Further, the above polyester coating composition contains an acid catalyst as a curing catalyst in an amount of 0.01 to 3 parts by mass based on 100 parts by mass of the total resin solid content (total of polyester resin and curing agent). It is preferable. Examples of acid catalysts include sulfuric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalene disulfonic acid, camphorsulfonic acid, phosphoric acid, and amine block (amine block) acid catalysts. Examples include those partially or completely neutralized with a compound, and one or two or more of these can be used in combination. Among these acid catalysts, dodecylbenzenesulfonic acid and amine-blocked dodecylbenzenesulfonic acid are particularly preferred from the viewpoint of compatibility with the resin and hygiene.

Such a polyester coating composition is coated on one surface (sometimes as a cup) of a metal blank to be subjected to plastic working by a conventionally known method such as a roll coating method, a spray method, a dipping method, or a brush coating method. It is applied to the outer surface (the side that will become the outer surface) and baked at a temperature of 100 to 300°C, particularly 150 to 270°C. The baking time is usually 5 seconds to 30 minutes, preferably 15 seconds to 15 minutes.

Further, the thickness of the coating film is preferably 7 μm or less, particularly in the range of 0.4 to 3.0 μm, in terms of dry film thickness (corresponding to the film thickness when formed into the metal cup 1). By being within the above range, a polyester coating film with good color development can be formed on the outer surface of the metal cup 1 with good adhesion.

A transparent resin coating layer 22 is formed on the polyester coating film 21 formed on the metal base plate as described above. The resin coating layer 22 is firmly bonded to the metal base plate using the colored polyester coating 21 as a primer, and the color of the underlying polyester coating can be visually recognized.

The resin used to form the resin coating layer 22 is not particularly limited, and includes, for example, crystalline polypropylene, crystalline propylene-ethylene copolymer, crystalline polybutene-1, crystalline poly4-methylpentene-1, Polyolefins such as low-, medium-, or high-density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ionically crosslinked olefin copolymer (ionomer); polystyrene; Aromatic vinyl copolymers such as styrene-butadiene copolymers; halogenated vinyl polymers such as polyvinyl chloride and vinylidene chloride resins; nitrile polymers such as acrylonitrile-styrene copolymers and acrylonitrile-styrene-butadiene copolymers ; Polyamides such as nylon 6, nylon 66, para- or metaxylylene adipamide; Polyesters such as polyethylene terephthalate (PET) and polytetramethylene terephthalate; Various polycarbonates; Thermoplastic resins such as polyacetals such as polyoxymethylene Plastic film composed of phenolic resin, melamine resin, alkyd resin, unsaturated polyester resin, epoxy resin, epoxy acrylic resin, epoxy phenol resin, epoxy urea resin, bismaleimide resin, triallyl cyanurate resin, thermosetting resin Resin paints using type acrylic resins, silicone resins, oil-based resins, etc., or thermoplastic resin paints, such as vinyl organosol, vinyl chloride-vinyl acetate copolymer, partially saponified vinyl chloride-vinyl acetate copolymer, vinyl chloride Examples include resin paints using -maleic acid copolymers, vinyl chloride-maleic acid-vinyl acetate copolymers, acrylic polymers, saturated polyester resins, and the like.

In the present invention, among the above-mentioned resins, polyester resins, such as polyester Terephthalate (PET) can be suitably used.

In addition, the above-mentioned thermoplastic resin only needs to have a molecular weight within the film-forming range, and from the viewpoint of barrier properties against corrosive components and mechanical properties, especially polyester, it is necessary to use a mixed solvent of phenol/tetrachloroethane. It is preferable that the measured intrinsic viscosity [η] is 0.5 or more, especially in the range of 0.52 to 0.70, and the glass transition point is preferably 50°C or more, especially in the range of 60°C to 80°C. preferable.

The above-mentioned resin can be blended with known film compounding agents, lubricants, anti-blocking agents, pigments, various antistatic agents, antioxidants, etc., as long as transparency is not impaired. .

The resin coating layer 22 can be formed by forming a film using the thermoplastic resin and then coating it on the polyester coating using a thermal bonding method. Alternatively, an extrusion lamination method may be used in which the polyester film is extruded into a film and directly coated on a polyester coating film formed on a metal base plate.
Further, when a thermoplastic resin film is used to form the covering layer 22, the film may be stretched, but an unstretched film is preferable from the viewpoint of moldability and dent resistance.
The thickness of the polyester film is generally preferably in the range of 5 to 40 μm.

As described above, it is possible to obtain a laminate plate in which the polyester coating film 21 and the resin coating layer 22 are formed on the outer surface of the metal cup 1.

In addition, examples of the primer 23 formed on the inner surface include coatings derived from paints such as polyester paints, acrylic paints, urethane paints, silicone paints, and fluorine paints. The resin coating layer 23 is formed on the resin coating layer 23 by thermal bonding or extrusion lamination using the same resin as the resin coating layer 22 described above.

The metal cup 1 of the present invention obtained by plastically working the above-mentioned laminate plate into the form shown in FIG. , to be commercially available.
Since the entire outer surface of such a metal cup 1 is colored, including the bottom, it exhibits high decorative properties, and when the body is printed, the printed image can maximize the appearance improvement. Furthermore, it exhibits stable stackability and improved strength.

1: Metal cup 3: Body part R: Curved part 5: Grounding part 7: Bottom part 9: Curled part 10: Hollow space (or hollow opening)
20: Metal wall 21: Polyester coating film 22: Resin coating layer 23: Primer 24: Resin coating layer α: Inflection point portion

Claims (7)

It has a hollow shape with an open top, the inside diameter of the top end is larger than the outside diameter of the bottom end, and the body has a shape that slopes from the top to the bottom. a stackable metal cup having a bottom portion with a grounding portion connected to the bottom portion;
A stackable metal cup characterized in that a resin coating layer is provided over the entire inner and/or outer surface of a metal wall forming the cup via a colored polyester coating. When viewed from the side, an inflection point portion α formed by a change in the inclination angle with respect to the vertical plane is provided on the outer surface of the body in an upper region A1 including the upper end and a lower region A2 including the ground contact portion, respectively. The stackable metal cup according to claim 1, comprising at least one stackable metal cup. The height of the upper region A1 is in the range of 70% to 100%, and the height of the lower region A2 is in the range of 40% or less, assuming that the height H from the grounding part to the upper end is 100%. Stackable metal cup according to claim 2. 4. The stackable metal cup according to claim 3, wherein an inclination angle difference Δθ defining the inflection point portion α is 25 degrees or less. A plurality of inflection point portions α where the inclination angle of the body portion changes are formed in an intermediate region A3 between the upper region A1 and the lower region A2, and the inflection point formed in the intermediate region A3 The stackable metal according to claim 4, wherein the inclination angle differences Δθ defining the portion α are all smaller than the inclination angle differences Δθ defining the inflection point portion α existing in the upper region A1 and the lower region A2. cup. The stackable metal cup according to claim 1, wherein the polyester coating has a thickness of 10 μm or less. 7. The stackable metal cup according to claim 1, wherein the polyester coating film contains any one of a phenol resin, an amino resin, and an isocyanate resin as a curing resin component.

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