JP2006044659A - Bottle can - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bottle can in which a cap thereof can be comfortably opened/closed by a consumer by keeping an adequate rotational torque without increasing the rotational torque of the cap when opening/closing the cap of the bottle can with the temperature of the bottle can itself being raised when the bottle can is subjected to retort sterilization or sold for a consumer with a size coating or an over-varnish for enhancing the corrosion resistance or being hardly damaged. <P>SOLUTION: A male screw part 17 to be screwed with a female screw part 31 provided on a cap 30 is provided on a mouth part 13, and a bottle can 10 is opened/closed by turning the cap 30. The mean film thickness of a film applied on an outer surface of the male screw part 17 is 5.0-10.1 μm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bottle can, and more particularly, to a bottle can with a cap filled with contents that require retort sterilization.

  In general, a bottle can widely used as a beverage can has a mouth at the top by drawing a metal plate made of aluminum or an aluminum alloy and then performing an ironing process. Manufactured (see Patent Document 1). The mouth portion is provided with a male screw portion that is screwed into a female screw portion provided on the cap on the outside. As a result, after the beverage is filled, the cap is screwed onto the mouth of the bottle can and then closed, and then sold to the consumer. In addition, when opening a bottle can, it rotates in the direction which spaces apart a cap from a bottle can.

  In such a bottle can, various coating processes are performed before or after the processing of the metal plate. Specifically, first, a size coating is applied to the surface of the can base of the bottle can, and after sufficiently baking and drying, information or a pattern that matches the contents is further printed using ink. On top of that, overburnish is painted in a wet-on-wet format. In addition, the coating process which paints the size coating and over burnish which were mentioned above is applied also to the whole bottle can, ie, the opening part of a bottle can. The size coating is generally applied for the purpose of improving the adhesion between the ink applied thereafter and the metal surface. The overburnish is applied for the purpose of protecting the painted surface and improving the slippage of the can surface.

  When the mouth part of the bottle can is thus painted, the cap rotates smoothly when the bottle can is closed and opened using the cap. In addition, the coating film makes it difficult to damage the outer surface of the bottle can, including the mouth portion of the bottle can, and the safety as a beverage product is enhanced. At the same time, the commercial value is maintained. In addition, in the above-mentioned bottle can, what is called a retort sterilization process which heats and sterilizes to about 120 degreeC after drink filling is generally performed. In addition, when placed on the market, it is generally sold after being heated to about 40-70 ° C.

  However, the bottle can described above has a glass transition point of the coating film close to 40-70 ° C, so it can be heated to around 120 ° C during retort sterilization treatment, or it can be warmed up to about 40-70 ° C in market sales. If it is applied, the above-described coating film by size coating or over-burnishing is softened, and the softening makes it difficult for the cap to rotate smoothly. That is, the force (opening torque) required to rotate the cap is increased, and the bottle can hardly be opened by the consumer. Such bottle cans that are difficult to open cause discomfort to consumers, reduce the desire to purchase, and lead to a decrease in sales of bottle cans.

In addition, if the thickness of the coating film such as overburnish is reduced, the opening torque described above can be lowered, but if the thickness is too thin, the bottle can is easily damaged, and the original coating film is formed. The significance will be lost.
Utility Model Registration No. 2545609

  The present invention has been made in view of the above circumstances, and is intended to improve the corrosion resistance and make it difficult to be damaged. When the temperature of the bottle can itself is raised when it is sold to consumers or consumers, the rotational torque of the cap at the time of opening and closing the bottle can is not increased, and the rotational torque is kept at an appropriate level. The object is to provide a bottle can that can be opened and closed comfortably.

In order to achieve the above object, the present invention provides a bottle can having the following means.
That is, the invention according to claim 1 is a bottle can that is provided with a male screw part that is screwed with a female screw part provided in a cap, and is opened and closed by rotating the cap. The average film thickness of the outer surface of the male screw portion is 5.0 to 10.1 μm.

  The bottle can according to the present invention is formed so that the average film thickness of the outer surface of the male screw portion screwed with the female screw portion provided in the cap provided in the mouth portion is 5.0 μm or more. Therefore, the exposure of the metal forming the mouth portion of the bottle can is prevented. Therefore, the metal forming the mouth portion is protected from corrosion due to oxidation or the like and is hardly damaged, which is preferable in terms of hygiene for consumers. Moreover, since the average film thickness of the coating film was formed to be 10.1 μm or less, the outer surface of the male screw portion is not unnecessarily bulky. As a result, when the male screw portion, which is generated due to the bulkiness, is screwed into the female screw portion, the male screw portion is unlikely to sink into the female screw portion. Accordingly, the sliding between the male screw portion and the female screw portion is smooth.

  The invention according to claim 2 is characterized in that, in the bottle can according to claim 1, the can body portion is covered with a shrink film.

  In the bottle can according to the present invention, when the bottle can is transported, the shrink film protects the coating film on the can body portion which has been thinned by coating the entire surface of the bottle can, and the coating film is peeled off. It is difficult to be done. Moreover, since the opening torque for opening the bottle can is appropriate, even if a circumferential force is applied to the film, the amount of twist of the shrink film can be reduced. In addition, a bottle can suitable for retort sterilization can be obtained.

  According to the bottle can according to the present invention, while the size coating or overburnish is applied for the purpose of improving the corrosion resistance and making it difficult to be damaged, for retort sterilization treatment and for consumers When the temperature of the bottle can itself is raised at the time of sale, consumers do not increase the rotational torque of the cap when opening and closing the bottle can, and the consumer can open it comfortably by keeping the rotational torque at an appropriate level. Can be plugged.

Hereinafter, bottle cans according to embodiments of the present invention will be described with reference to the drawings.
A bottle can 10 of this embodiment shown in FIG. 1 is made of aluminum or an aluminum alloy. That is, the can base 11 includes a horizontally formed bottom surface portion 12 formed in a circular shape, a can body portion 14 formed vertically extending from the bottom surface portion 12 through a taper portion 13, and the can The body 14 includes a can shoulder 15 having a reduced diameter, and a can mouth 16 serving as a mouth of a beverage to be filled. A male screw portion 17 is formed on the outer side of the can mouth portion 16, and a female screw portion 31 to be screwed with the male screw portion 17 is formed on the cap 30. A coating film 20 is formed on the can base 11 including the can mouth portion 16 including the male screw portion 17. A liner material 32 is disposed on the back side of the cap 30, and the cap 30 preferably closes the bottle can 10 when the liner material 32 comes into close contact with the opening 18 of the can opening 16. Although not shown, the cap 30 is temporarily fixed to a bridge support provided in the bottle can 10 via the bridge. Then, the consumer rotates the cap 30 to cut the bridge, and opens the bottle can 10.

  The coating film 20 of the male screw portion 17 provided in the can mouth portion 16 described above is formed by being applied in a single or double manner. Further, the coating film 20 is applied in an overlapping manner so that a blanking portion is not formed, so that a coating start portion and a coating finish portion overlap each other. And the average film thickness of the coating film 20 is coated so that it may become 5.0-10.1 micrometers, and the coating film 20 is formed.

Next, the manufacturing method of the bottle can 10 is demonstrated using the manufacturing-process figure of FIG.
A DI can (bottomed tubular body) 43 is formed by first subjecting an aluminum disc 40 formed by punching an aluminum plate into a circular plate of a predetermined size to a DI processing step. The DI processing step includes drawing processing for forming the cup 41 from the aluminum disc 40, redrawing processing and ironing processing for forming the cup 41 on the cylindrical can body 42 having a predetermined height, A trimming process in which the upper end 42a is cut and aligned to form a DI can 43. A cup 41 having a thickness substantially the same as the thickness of the aluminum disk 40 is processed into a cylindrical can body 42 having a predetermined thickness and height by redrawing and ironing. At this time, the cylindrical can body 42 is processed. The upper end 42a is not uniformly deformed, but is deformed in a mountain-and-valley shape. This mountain-and-valley portion is usually called an “ear” and is cut by trimming. Thereby, the upper end 43a of the DI can 43 is formed at a uniform height. After the DI processing step, it is washed with a washer and subjected to chemical conversion treatment with chromium, zirconium or the like in order to improve corrosion resistance.

  The original can base 44 having a coating layer on the surface of the DI can 43 is formed by subjecting the DI can 43 formed by the DI processing process to a coating process having a plurality of painting operations to be described in detail later. Then, the prototype can base 44 becomes a prototype bottle can 45 in which the can shoulder portion 15 is formed by the neck-in process and then the can mouth portion 16 is also formed. Thereafter, the can mouth portion 16 is formed with a male screw portion 17 by a known molding roller or the like, and becomes a molded bottle can 46 (10). Although not shown in the figure, after the bottle can 10 is filled with a beverage, the original cap is covered with the can mouth portion 16 and the female screw portion is fitted to the male screw portion 17 by a known molding roller or the like. 31 is formed and becomes the cap 30.

Below, the coating process performed on the surface of DI can 43 mentioned above is demonstrated.
The coating process is performed by spraying paint, and the coating is performed so as to go around the entire circumference 10 </ b> A of the can base 11. Further, in the above-described coating process, the coating circulation start portion and the coating circulation end portion are painted so as to overlap so that the entire circumference 10A of the bottle can 10 is suitably coated. This overlapping part is formed as an overlapping part of the coating film 20. The can base 11 is coated with 1.3 turns, and an overlap is formed for 0.3 turns.

  A specific coating process will be described. A size coating is applied so as to circulate around the entire circumference 10A of the can base 11, an ink is applied thereon, and an over burnish is applied thereon. In this state, the entire circumference 10A of the can base 11 is heated and dried. Thus, the coating film 20 in this invention is formed, and the average film thickness of the coating film 20 is 5.0 to 10.1 μm.

  As the raw material for the above-mentioned size coating, for example, a resin material (polyester resin, amino resin, etc.) is dissolved in a solvent (cyclohexanone, Solvesso 100, Solvesso 150, propylene glycol monomethyl ether acetate, etc.). An appropriate pigment may be added to the size coating.

  Moreover, as raw materials for overburnishing, resin materials (polyester resin, amino resin, acrylic resin, epoxy resin, etc.) are used as solvents (Solvesso 150, Swazol 1000, xylene, toluene, 1-butanol, isobutanol, diethylene glycol monobutyl ether). Acetate, etc.) is dissolved, and a wax (0.9 lanolin, 0.3 carnauba, 0.6 microclostalin polyethylene, 0.3PTFE, etc.) is added.

  The table shown below is a table in which the coating film 20 is formed by the above-described size coating, overburnishing, or the like, and the opening torque and the scratch characteristics at the average film thickness of the various coating films 20 formed are tested. That is, when the can base 10 is coated with 1.3, 1.5, or 2.1 turns, the average thickness of the coating film 20 is 4.2 μm, 5.0 μm. , 7.4 μm, 8.6 μm, 9.2 μm, 10.1 μm, and 10.8 μm. When the can base 10 is coated 1.3 times and 1.5 times, the coating film 20 to be tested is overlapped by overlapping two times, and the can base In the case where the coating film 20 is painted in 2.1 rounds, the coating film 20 to be tested becomes a part that is overlapped by three coatings.

  In the opening torque test, first torque and second torque are tested. That is, the first torque among the opening torques means a rotational torque required to rotate the cap 30 to cut a bridge that is temporarily fixed to the bridge supporter. Of these, the second torque usually means the rotational torque required to rotate the cap 30. In addition, when the magnitude of the opening torque is 200 N · m or less, it is assumed that the opening is easy for the consumer.

  In the scratch test of the paint film, the cap 30 is opened and closed 50 times, and it is determined whether or not the paint film 20 applied to the mouth portion 13 is peeled off (scratched). . That is, it is indicated as “◯” when there is no peeling of the coating film 20, and “X” when the coating film 20 is damaged.

  As can be seen from Table 1 shown above, when the average film thickness of the coating film 20 is 10.8 μm or more, the first torque of the opening torque exceeds 200 N · m, and consumption Has become a bottle can difficult to open. In addition, when the average film thickness of the coating film 20 is 4.2 μm or less, it becomes a bottle can that can be opened comfortably by the consumer, but the can mouth portion 16 has minute scratches. It became. From such a test result, it can be said that the average film thickness of the coating film 20 is preferably 5.0 to 10.1 μm.

  That is, in the bottle can 10 described above, since the average film thickness of the coating film 20 formed on the outer surface of the male screw portion 14 of the bottle can 10 after manufacture is formed to be 5.0 μm or more, The exposure of the metal forming the bottle can mouth portion 16 is prevented. Accordingly, the metal forming the mouth portion 16 is protected from corrosion due to oxidation or the like, and is hardly damaged, which is preferable in terms of hygiene for consumers. Moreover, since the average film thickness of the coating film 20 was formed to be 10.1 μm or less, the outer surface of the male screw portion 17 is not unnecessarily bulky. As a result, when the male screw portion 17 is screwed into the female screw portion 31, which is caused by the bulk, the male screw portion 17 is unlikely to be caught in the female screw portion 31. Therefore, the sliding of the male screw portion 17 and the female screw portion 31 is smooth.

  Therefore, bottle cans can be used during retort sterilization treatment or when sold to consumers while size coating and overburnishing are applied to improve corrosion resistance and make it difficult to damage. Even if the temperature of the bottle 10 itself is raised, the consumer can comfortably open and close the bottle by keeping the rotation torque at an appropriate level without increasing the rotation torque of the cap 30 when the bottle can 10 is opened and closed. .

  Further, since the bottle can 10 is coated with the overburnish 23 on the entire circumference 10 </ b> A of the can base 11, the entire bottle can 10 can have good corrosion resistance. In addition, since the overburnish 23 is hard and slippery, the effect of improving the wear resistance of the surface and reducing friction can be obtained.

  For example, in the above-described embodiment, the coating for forming the coating film 20 is formed by spraying paint, but is not limited thereto, and is formed by transfer of the gravure roll G. There may be. When the gravure roll G is formed by transfer, the gravure roll is formed such that the depth d1 of the groove M1 provided in the gravure roll G becomes the depth d2 of the half groove M2, as shown in FIG. G is polished. When the depth d2 of the groove M2 is thus set, the coating film 20 can be formed to have a desired thickness. When the coating film 20 is formed by transferring the gravure roll G, the coating film 20 of the bottle can 10 can be applied in a large amount and at a low cost while maintaining a desired film thickness.

  Further, after the bottle can 10 is manufactured as described above, the can body portion 17 of the bottle can 10 may be covered with a shrink film. In the case where the can body portion 17 of the bottle can 10 is covered with a shrink film, the shrink film is thinned by coating the entire surface of the bottle can 10 when the bottle can 10 is transported. It is assumed that the coating film 20 of the can body 17 that has been damaged is protected, and the coating film 20 is unlikely to be peeled off. In addition, since the opening torque for opening the bottle can 10 is appropriate, even when a circumferential force is applied to the film, the amount of twist of the shrink film can be reduced. Furthermore, it can be set as the bottle can 10 suitable for a retort sterilization process.

Note that the present invention is not limited to the above-described embodiment, and appropriate selections can be made without departing from the spirit of the present invention.
Further, in the bottle can, the configuration in which the coating film is formed is such that the coating film is formed by the size coating and overburnishing as described above, but is not limited thereto, and is necessary as appropriate. All the coating films formed by the coating process may be included. In addition, the coating treatment is not limited to being performed in the order of steps as in the above-described embodiment, and may be performed at an appropriate process location.
Further, although the bottle can material is formed of aluminum or aluminum alloy, the present invention is not limited to this, and the bottle can may be formed using other metals.

It is a partial notch whole side view of the bottle can which concerns on this invention. FIG. 2 is a schematic manufacturing process diagram of the bottle can shown in FIG. 1. It is a cross-sectional view of a gravure roll when a coating film is formed by transfer of the gravure roll.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bottle can 13 Mouth part 17 Male thread part 20 Paint film 30 Cap 31 Female thread part

Claims (2)

A bottle can which is opened and closed by rotating a cap by providing a male screw portion screwed with a female screw portion provided on a cap,
The bottle can characterized in that the average film thickness of the outer surface of the painted male screw portion is 5.0 to 10.1 μm. The bottle can according to claim 1,
A bottle can characterized in that a can body is covered with a shrink film.

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