JP2009067401A - Tubular metal container and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tubular metal container in which printing on the outer peripheral face of its barrel portion can be beautifully finished without deviating from the conventional processing and a coating film with a uniform thickness can be applied to its internal face stably. <P>SOLUTION: A metal tube is formed so that at least the tubular barrel portion, a shoulder portion formed narrower than the barrel portion, and a discharging portion for contents are integrated. In this metal tube, the circumferential external face of a joint portion (a changing portion) between the barrel portion and the shoulder portion is bent at a specific angle. The circumferential internal face of the changing portion has R, which is preferably in the range of 0.5 to 2.0. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a metal tube container capable of obtaining a stable inner surface coating film and a method for producing the metal tube container.

Conventionally, a metal tube made of aluminum or the like is generally integrally formed by an impact press method using 99.7% pure aluminum. Patent document 1 is mentioned as an example of an impact press machine.
The material itself such as aluminum, which is a material of such a metal tube, is easy to work and low in cost, but reacts with both acid and alkali, so that the range of application as a container is narrow by itself. Therefore, it is essential to apply a baking coating (coating) such as an epoxy resin on the inner surface of the tube to prevent reaction with the contents.

On the other hand, in recent years, metal tubes are hard and difficult to use, have a large bulk remaining, can be torn during use and the contents can leak, and it has been pointed out that it is difficult to print highly beautiful products on the outer surface of the body Has been.
In addition, the development of resin grades and UV inks, the advancement of resin molding technology, etc., have led to the development of resin for tube containers in many fields. Currently, the fields where aluminum tubes are used are pharmaceuticals, industrial products, hair dyes, etc., and resin tubes are limited to special fields where the quality of the contents cannot be maintained. That is, the metal tube is used in a special field where the quality of the resin tube cannot be maintained in view of functions such as a high barrier property, high air permeability and no virgin property.

  Therefore, due to the particularity of the contents, the importance of inner surface coating technology is increasing more than ever for metal tubes. In particular, a hair dye containing a strongly alkaline dye in the composition has a strong degree of erosion of the metal tube and has higher characteristics required for the inner surface coating technology. Specifically, in order to completely prevent contact with the aluminum fabric, it is required to coat the coating film highly resistant to the contents with high accuracy and uniformity. Examples of general inner surface coating methods include Patent Documents 2 and 3.

Here, the difficulty in coating the inner surface of the metal tube is due to the internal structure of the metal tube. FIG. 7 is a partial cross-sectional view showing a coating state of a conventional metal tube. As shown in FIG. 7, the metal tube 70 includes a cylindrical body 71, a shoulder 72 narrowed more narrowly than the body 71, a discharge part 74 for contents, and an opening at the tip thereof. 75 or the like. It is very difficult to uniformly form and burn the coating film 76 on the inner wall surface having such a complicated shape.
In particular, a portion where uniform inner surface coating 76 is difficult is a joint portion (hereinafter referred to as a “switching portion”) 77 between the body portion 71 and the shoulder portion 72. Since such a joint is bent at an angle, when a paint is to be applied thickly to the part, the corner is accumulated by the paint, or the paint flows out due to surface tension or wind pressure during spraying. The phenomenon occurred and the coating thickness was uneven. And it was difficult to adjust the inner surface coating method for obtaining an inner surface coating film having a uniform thickness with a stable coating thickness.
Further, in the metal tube 70, the outer circumferential surface 79 of the joint portion between the body portion and the shoulder portion needs to be bent at an angle in order to finish the outer printing (ground coating) 78 beautifully. Therefore, there is also a problem that a metal tube that satisfies the requirements cannot be obtained simply by forming the joint portion between the body portion and the shoulder portion with a rounded shape.

JP 2001-150196 A JP-A-8-300078 JP 2006-96381 A

  The present invention solves the above-mentioned problems of conventional metal tubes, and beautifully finishes printing on the outer peripheral surface of the body without departing from the conventional process, and has a stable and uniform thickness. It aims at providing the metal tube container from which an inner surface coating film is obtained.

  As a result of intensive research, the inventor has formed a circular inner surface of the contact portion (switching portion) between the body portion and the shoulder portion of the metal tube, and the circumferential outer surface of the switching portion is bent at an angle. As a result, it was found that the outer base coating was also finished beautifully together with the stable inner coating film, and the present invention was achieved.

That is, this invention has the following structures in order to solve the said subject.
(1) The present invention relates to a metal tube in which at least a cylindrical body part, a shoulder part narrowed from the body part and a discharge part for contents are integrally formed, and a joint part (switching part) between the body part and the shoulder part The outer circumferential surface of the metal tube container is bent with an angle, and the circumferential inner surface of the switching portion is formed with a rounded shape.
(2) The metal tube container according to (1), wherein the metal tube is formed of a material mainly composed of aluminum.
(3) The opening of the discharge part is sealed with a metal member and is integrally formed with the discharge part, and a groove for screwing the cap onto the outer peripheral surface of the discharge part is rolled. The metal tube container according to the above (1) or (2).
(4) The metal tube container according to any one of (1) to (3) above, wherein a radius of a circumferential inner surface of the switching portion is R0.5 to 2.0.
(5) The metal tube container according to any one of the above (1) to (4), wherein a concave groove is formed on a peripheral surface in the vicinity of the joint portion of the body portion.
(6) A metal tube container for hair dye, wherein a hair dye is enclosed in the metal tube container described in any one of (1) to (5) above.

(7) In a method of manufacturing a metal tube in which at least a cylindrical body, a shoulder narrowed narrower than the body, and a discharge part of contents are integrally formed, the shape of the shoulder and discharge part of the metal tube is transferred Prepare a female mold in which a die ring is fitted on the outer periphery of the formed die bottom, prepare a male mold with a punch head with a round head formed on the outer peripheral surface of the punch shaft, and prepare a metal material in the female mold After placing the slag, an impact press process is performed in which a male mold is driven and an impact is applied, whereby the circumferential outer surface of the switching portion is bent at an angle, and the circumferential inner surface of the switching portion is formed with a radius. It is the manufacturing method of the metal tube container characterized.
(8) The method for producing a metal tube container according to (7), wherein the slag is a material mainly composed of aluminum.
(9) The method for producing a metal tube container according to (7) or (8), wherein a concave groove is formed by embossing on a peripheral surface in the vicinity of the joint portion of the body portion.
(10) The metal as described in any one of (7) to (9) above, wherein after the impact pressing step, the discharge portion is turned and annealed, and then the inner surface of the metal tube is spray-coated. It is a manufacturing method of a tube container.
(11) The manufacturing method of the metal tube container described in any one of (7) to (10) above, wherein the outer periphery of the tip end of the punch head is R0.5 to 2.0. . (12) Production of a metal tube container for a hair dye as described in (10) or (11) above, comprising a step of filling and sealing the hair dye from the opening after the spray coating process. Is the method.

  The present invention has an effect of providing a metal tube capable of beautifully finishing printing on the outer peripheral surface of the body portion and obtaining a stable inner surface coating without departing from the conventional process.

Hereinafter, an example of a metal tube container according to the present invention will be described with reference to the drawings.
FIG. 1 is a partial sectional view of a metal tube container 10 according to the present invention. The metal tube container which concerns on this Embodiment 1 is preventing the accumulation | storage and repelling of an inner surface coating by attaching a round to the circumferential inner surface 7 of the switching part 3 of the trunk | drum 1 and the shoulder part 2 of a tube container. Further, the circumferential outer surface side 9 of the switching portion 3 between the body portion 1 and the shoulder portion 2 of the tube container is bent at an angle so that the edge of the ground coating can be printed sharply.
Moreover, the metal tube container 10 which concerns on this embodiment changes the structure of the spray gun for the conventional inner surface coating by attaching a radius to the inner peripheral inner surface 7 of the switching part 3 of the trunk | drum 1 and the shoulder part 2 of a tube container. The paint can be thickly applied to the inner surface of the container (particularly the circumferential inner surface 7 of the switching portion) with high accuracy and uniformity. When the circumferential inner surface 7 is bent at an angle, paint such as epoxy resin sprayed from the spray gun for inner surface coating accumulates at the corner of the switching portion, or due to surface tension, wind pressure, etc. from the corner-shaped portion This is because repelling occurs.

The metal tube container 10 according to the present embodiment is formed using aluminum, lead, tin or the like as a material. In particular, it is preferably formed of a material mainly composed of aluminum from the viewpoint of environmental hygiene, cost, and ease of processing.
Further, in the metal tube container according to the present embodiment, the tip 5 of the discharge portion 4 is integrally formed with the discharge portion by metal, and a groove 6 for screwing a cap onto the outer peripheral surface of the discharge portion 4 as shown in FIG. Is preferably rolled. The groove 6 is for screwing a cap (not shown) that protects the contents after opening the tip 5.
The radius of the circumferential inner surface 7 of the switching unit 3 is preferably R0.5 to 2.0. R1.5 is more preferable. If it is less than R0.5, there is a risk of dripping or the like, and if it exceeds R2.0, the contents will deteriorate in terms of the extrudability.

  Moreover, you may form the concave groove | channel 11 as shown in FIG. This concave groove 11 is deformed so that the groove 11 is folded against the contraction stress generated in the vicinity of the joint when the contents are pushed out, and is deformed so that the groove 11 extends against the tensile stress. And it has the effect | action which absorbs these stresses.

The inner diameter of the tube at the bottom of the concave groove 11 may be smaller than the outer diameter of the joint. Therefore, the axial cross-sectional shape of the concave groove 11 may be not only U-shaped but also V-shaped, bellows-shaped W-shaped, or the like.
Further, the shape of the concave groove 11 may be continuous or discontinuous along the peripheral surface as long as it is a structure that is folded on the inner surface of the shoulder. It suffices to be provided at least at a site for absorbing deformation caused by shrinkage stress and tensile stress.

Next, the manufacturing method of the metal tube container which concerns on this embodiment is explained in full detail.
In the metal tube container according to the present embodiment, it is necessary to bend the circumferential outer surface of the switching portion between the trunk portion and the shoulder portion at an angle, to form a round shape on the circumferential inner surface, and to form a cylindrical trunk portion.
Therefore, the shape of the circumferential outer surface of the switching portion is formed by the female die bottom 20 and the die ring 21 shown in FIG. 3, and the shape of the circumferential inner surface is formed by the tip of the male punch head 22. The male punch head 22 is configured by being attached to a punch shaft 26. A rounded portion is formed at the switching portion forming portion 27 of the punch head 22. In the female die, a die bottom 20 and a die ring 21 form a bent portion 29 having an angle at a portion corresponding to the circumferential outer surface of the switching portion. Reference numeral 30 denotes an extrusion pin.

After the slag 24 is disposed in the female mold, the punch head 22 is driven into the die bottom 20 and the die ring 21, and the slag 24 is pushed out through the gap between the punch head 22 and the die ring 21 by the impact. Forming part. Note that the dimensions and shapes of the female mold and male mold in FIG. 3 are not necessarily accurate.
Here, the punch head 22 is fixed to the punch shaft via a joint screw (not shown). A radius is formed at the switching portion forming portion 27 of the punch head.
In the female mold, a die ring 21 is fitted on the upper surface of the die bottom 20, and an ejector pin 30 is inserted in the central axis direction.

FIG. 4 is an enlarged front view of the punch head 22 used in FIG. As shown in FIG. 4, a radius is formed at the switching portion forming portion 27 of the punch head 22. The radius is preferably R0.5 to 2.0. More preferably, it is R1.5.
By such an impact press process, the outer circumferential surface of the switching portion is bent at an angle, and the metal tube container according to the present embodiment in which the round is formed on the circumferential inner surface of the switching portion is manufactured.

Next, the discharge part of the metal tube container manufactured by the above process is turned and annealed, and the inner surface of the metal tube container is spray-coated. Spray coating is efficiently performed by the method shown in FIG.
The spray gun is a long-axis nozzle type. As a basic operation, the spray gun is applied by inserting the spray gun from the rear end opening of the metal tube container toward the tip of the tube and retreating it while spraying the paint. After the impact press process, the created metal tube container is subjected to a lathe machining process and an annealing process, and then conveyed to the inner surface coating table by the roving star 48 shown in FIG.

As shown in FIG. 5D, the inner surface of the metal tube container on the table A is applied by inserting a spray gun 53 and spraying the paint onto the inner surface of the shoulder portion and the inner surface of the trunk portion. At this time, the metal tube container is preferably rotated. Here, since the round is formed on the circumferential inner surface of the switching portion between the body portion and the shoulder portion of the tube container, the paint can be applied to the circumferential inner surface of the switching portion with high accuracy and uniformity.
Here, as the coating material, for example, a thermosetting resin, a thermoplastic resin, a dispersion type coating material, a low temperature curing type coating material, or the like can be used. Specifically, epoxy phenol of an epoxy paint can be used.

The inner surface coating on the table B is performed by inserting the spray gun 53 of FIG. 5D and spraying the coating material on the inner surface of the shoulder portion and the inner surface of the trunk portion. At this time, the metal tube is rotating.
The inner surface coating on the table C is performed by inserting the spray gun 51 of FIG. 5B and spraying the coating material on the inner surface of the discharge portion and the inner surface of the shoulder portion. At this time, the metal tube is rotating.
The inner surface coating on the table D is applied by inserting the spray gun 52 shown in FIG. At this time, the metal tube is rotating.
The inner surface coating on the table E is performed by inserting the spray gun 52 shown in FIG. At this time, the metal tube is rotating.
The inner surface coating on the table F is performed by inserting the spray gun 51 of FIG. 5B and spraying the coating material on the inner surface of the discharge portion and the inner surface of the shoulder portion. At this time, the metal tube is rotating.
By such a process, a highly resistant coating film with high resistance to the contents of the metal tube can be uniformly and accurately applied. It is preferable that an intermediate drying step is interposed between step C and step D. Further, the combination of spray guns is not limited to the above steps.

After the inner surface coating process as described above, the outer surface of the metal tube container may be ground-coated, and the metal tube container may be manufactured through a drying process, a printing process, a drying process, a capping process, a sealing process, and the like.
If the manufacturing method of the metal tube container which concerns on this embodiment is used, the metal tube container of outer diameter (PHI) 11.1 mm-57.0 mm can be manufactured widely. Further, the shape of the discharge portion of the metal tube container is not limited, and various metal tube containers such as an open type, a closed type, and a pointed open type can be manufactured.

Next, based on an Example, the metal tube container based on this invention is demonstrated concretely.
Example 1
A metal tube container having an outer diameter of Φ27 mm and a length of 160 mm was produced using the impact press method shown in FIG. As punch heads to be attached to the punch shaft, five types were prepared in which the switching portion forming portion was a conventional product without R (normal type), R0.5, R1.0, R1.5 and R2.0. A total of 50 metal tube containers were manufactured in the press process using such a punch head.

The inside of the metal tube container is painted with a spray gun for internal coating (manufactured by Sprimag). A spray gun can uniformly coat the joint between the body and shoulder of the tube container. Here, epoxyphenol was used as the paint for the inner surface coating. And the coating material used two types, the titanium containing epoxy phenol type solution (A liquid) for hair dyes, and an epoxy phenol type solution (B liquid).
In the present Example, the state of the inner surface coating of this metal tube container was evaluated. The results are shown in Table 1.
The evaluation of the inner surface coating was performed by visual evaluation of the finish, an energization value test, and a copper sulfate aqueous solution reaction test. In the energization value test, an energization measuring device 62 (manufactured by Shinko Electric Instrumentation Co., Ltd.) shown in FIG. 6 was used, and a 5% copper sulfate aqueous solution was used as the test solution 63. Specifically, it is a test solution obtained by diluting 50 g of CuSO ₄ .5H ₂ O, 5 ml of a surfactant (Rheodor), and 5 ml of glacial acetic acid with water to a total of 1000 ml.
In the copper sulfate aqueous solution reaction test, a 20% copper sulfate aqueous solution was used. Specifically, it is a test solution obtained by diluting 100 ml of concentrated hydrochloric acid and 200 g of CuSO ₄ .5H ₂ O with water to a total volume of 1000 ml.
In the energization value test procedure, the metal tube 61 is filled with a 5% copper sulfate aqueous solution 63, and the cathode electrons 64 are connected to the lower surface of the metal tube 61. As one anode, a Φ2 mm copper rod 65 was used to immerse in the test solution 63. A DC voltage of 7 V was applied and the maximum current value was measured for 30 seconds.
The procedure of the copper sulfate aqueous solution reaction test was carried out by drawing a 20% copper sulfate aqueous solution into a metal tube container and evaluating the inner surface of each tube container after 20 minutes, 2 hours, and 24 hours.
The test results are shown in Table 1.

In the test results above reporting, the punch life is obtained by displaying the result of exchange was observed period required for the punch head (see FIG. 4) in the metal tube during manufacture according to the present invention.
As shown in Table 1, it was found that the metal tube in which the circumferential inner surface of the switching portion was bent to R2.5 had a short punch life. Here, “short punch life” means that the punch head needs to be replaced before 100,000 metal tube containers can be manufactured. A punch life of “slightly short” means that the punch head needs to be replaced when 100,000 metal tube containers are manufactured. Furthermore, “good” indicates a state in which the punch head does not need to be replaced even after the production of 100,000 metal tube containers is completed.
In addition, “extrusion” refers to pressing the barrel of a metal container filled with contents (in this example, “hair dye” was used) and pressing the barrel with the contents almost squeezed out. It shows the result of visual evaluation of the remaining bulk remaining on the back side of the switching part of the metal container, in particular. As shown in Table 1, the metal tube bent to R2.5 had a large bulk remaining amount.
Furthermore, as shown in Table 1, it was found that the energized value was generally lower in the case where the rounded inner surface of the switching portion was formed compared to the conventional product without the rounded portion. Here, when there is metal exposure on the inner surface coating film, the energization value increases. Therefore, it was found that the inner surface coating film of the metal tube according to the present invention was uniformly applied as compared with the conventional product.

It is a fragmentary sectional view showing an example of the metal tube container concerning this embodiment. It is a top view which shows an example of the other metal tube container which concerns on this embodiment. It is a conceptual diagram for demonstrating the impact press process used for the manufacturing method of the metal tube container which concerns on this embodiment. It is a front view of the punch head used for the manufacturing method of the metal tube concerning this embodiment. It is a conceptual diagram for demonstrating the inner surface coating process in the manufacturing method of the metal tube which concerns on this embodiment. It is a figure which shows the apparatus structure used for the energization value test. It is a fragmentary sectional view showing the conventional metal tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body part 2 Shoulder part 4 Discharge part 7 Circumferential inner surface (R formation part) of a switching part
9 Circumferential outer surface of switching part 10,50 Metal tube container

Claims (12)

In a metal tube in which at least a cylindrical body, a shoulder narrowed narrower than the body, and a discharge part for contents are integrally formed, the circumferential outer surface of the joint (switching part) between the body and the shoulder is an angle. A metal tube container, wherein the circumferential inner surface of the switching portion is formed with a rounded shape. The metal tube container according to claim 1, wherein the metal tube container is made of a material mainly composed of aluminum. The opening of the discharge part is sealed with a metal member and is integrally formed with the discharge part, and a groove for screwing a cap is rolled on the outer peripheral surface of the discharge part. The metal tube container according to claim 1 or 2. The metal tube container according to any one of claims 1 to 3, wherein a radius of a circumferential inner surface of the switching portion is R0.5 to 2.0. The metal tube container according to any one of claims 1 to 4, wherein a concave groove is formed on a peripheral surface in the vicinity of the joint portion of the trunk portion. A hair dye metal tube container, wherein a hair dye is enclosed in the metal tube container according to any one of claims 1 to 5. In the method of manufacturing a metal tube in which at least a cylindrical body part, a shoulder part narrower than the body part and a discharge part of contents are integrally formed, the shape of the shoulder part and the discharge part of the metal tube is transferred and formed Prepare a female mold with a die ring fitted on the outer periphery of the die bottom surface, prepare a male mold with a punch head attached to the punch shaft that has a rounded outer periphery on the tip, and place a metal slag in the female mold. After the placement, the male die is driven and subjected to an impact press step for applying an impact, whereby the circumferential outer surface of the switching portion is bent at an angle, and the circumferential inner surface of the switching portion is formed with a radius. A method for manufacturing a metal tube container. The method for producing a metal tube container according to claim 7, wherein the slag is a material mainly composed of aluminum. The method for manufacturing a metal tube container according to claim 7 or 8, wherein a concave groove is formed by embossing on a peripheral surface in the vicinity of the joint portion of the body portion. The method for producing a metal tube container according to any one of claims 7 to 9, wherein after the impact press step, the discharge portion is turned and annealed, and then the inner surface of the metal tube is spray-coated. The method of manufacturing a metal tube container according to any one of claims 7 to 10, wherein the radius of the outer periphery of the tip of the punch head is R0.5 to 2.0. The method for producing a metal tube container for a hair dye according to claim 10 or 11, further comprising a step of filling and sealing the hair dye from the opening after the spray coating process.

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