JP7101050B2 - A raw fabric for a light-shielding laminated tube, a body portion using the raw fabric, a container, and a method for manufacturing the body portion. - Google Patents

Description

The present invention relates to a technique for improving the light-shielding property in a laminated tube container, which has been a problem in conventional products. In particular, the present invention relates to a technique for blocking light leakage from a laminated portion of a metal layer by a laminated structure using a special material in addition to the metal layer and an end structure of a side seam portion.

Currently, laminated tube containers in which polyethylene, polyamide films, polyester films, metal foils, etc. are laminated are excellent in strength, moldability, flexibility, extrudability, etc., and are therefore used in a wide range of applications as tube containers. .. In such a tube container, a tubular body portion is manufactured from a raw fabric obtained by laminating polyethylene, a polyamide film, a polyester film, a metal foil, etc. by an adhesive or extruding, and then the body portion and the shoulder portion are joined or formed. Manufactured. The body portion is produced by cutting the raw fabric to a desired length, rolling it into a tubular shape, and welding the ends of the raw fabric with heat (hereinafter, also referred to as side seams). Alternatively, it is produced by side-seaming while forming a long tubular shape.

The contents of the laminated tube container are used for various purposes such as cosmetics, pharmaceuticals, toothpaste, and foods. In such a laminated tube, from the viewpoint of barrier property such as oxygen, it is a well-known technique to laminate a metal layer (generally, aluminum foil is often used) on an intermediate layer of a laminated raw material. It has become. Here, for pharmaceuticals, quasi-drugs, UV-cut products, seasonings, cosmetics, chemical materials, etc. that control the deterioration of the contents at a high level, in addition to preventing oxidation of the contents, light Transparency is known as a concern.
For example, Patent Documents 1 to 6 are known as techniques related to light-shielding properties. Patent Documents 1 to 3 disclose a light-shielding technique using a film in which aluminum is vapor-deposited on a polyolefin film or the like. Further, Patent Document 4 discloses a light-shielding technique in which a silicon oxide vapor-deposited layer and colored polyethylene are laminated. Further, Patent Document 5 discloses a technique using carbon black or the like as a light-shielding material. Further, Patent Document 6 also discloses a technique using carbon black.

All of the above techniques are techniques for preventing light transmission and the like by using a light-shielding film in the composition of the laminated material. Of course, it is possible to apply these techniques to light-shielding laminated tubes.
The raw fabric for a light-shielding laminated tube as described above uses a light-shielding material instead of a metal layer such as aluminum foil. Here, the raw fabric for the light-shielding laminated tube is special, and if a dark color such as carbon black is used, a concealing layer must be provided from the viewpoint of design, so aluminum foil or the like is used. It is known in principle that the cost is higher than that of raw fabric for laminated tubes. Therefore, it is common to laminate a metal layer (generally, aluminum foil is often used) as an intermediate layer.

However, on the cylindrical body portion for a laminated tube using a metal layer, a side seam portion is formed by superimposing the raw fabric and the raw fabric and performing heat welding. It is known as a fact that external light leaks into the inside of the container from the layer between the metal layer and the metal layer in the side seam portion, although the amount is small. Such intrusion of light can be a factor in altering the contents. For example, vitamin A and vitamin B2 contained in pharmaceuticals, cosmetics, etc. are sensitive to light, and there is a concern that even a minute leakage of light from the side seam portion causes deterioration.

For example, FIG. 2 shows a side seam portion 30 of a body portion for a laminated tube according to the prior art. As shown in FIG. 2, the raw fabric for a laminated tube according to the prior art is configured by superimposing the raw fabric having the outermost layer 31, the base material 32, the metal layer 33, and the innermost layer 34. In such a portion 30, the metal layer 33 prevents the intrusion of light from the outside (see the refracting arrow in FIG. 2), but overlaps the metal layer 33 of the original fabric which is overlapped upward and downward. It was known that external light penetrated into the inside through the gap between the metal layer 33 and the metal layer 33 of the original fabric (the arrow in FIG. 2 indicates the path of light). The problems of the prior art will be described in detail in the first embodiment described later.
The present inventor is continuing research with the aim of developing a laminated tube container that can be used in pharmaceuticals, cosmetics, etc., for which deterioration of the contents must be controlled at a high level. Then, although a laminated tube container using some light-shielding materials was actually manufactured, it was difficult to manufacture a laminated container that completely prevented the intrusion of light.

Japanese Unexamined Patent Publication No. 2013-22918 Japanese Unexamined Patent Publication No. 2016-104564 Japanese Unexamined Patent Publication No. 2017-52282 Japanese Unexamined Patent Publication No. 7-187205 Japanese Unexamined Patent Publication No. 6-298265 Japanese Unexamined Patent Publication No. 2014-141303

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and an object of the present invention is to prevent light from entering from a side seam portion in a laminated tube container.
In particular, by covering the end of the original fabric at the side seam with a light-shielding material, it is possible to prevent light from entering the inside of the laminated tube container from the gap between the metal layers of the side seam with higher accuracy. With the goal.

The present invention has adopted the following configuration in order to solve the above problems.
(1) A raw fabric used for a tubular body having a side seam in a laminated tube, wherein the raw fabric is formed by laminating three or more different materials, and among the three layers. The intermediate layer has a layer made of a metal material, and at least one layer on the inner layer side of the metal layer when molded into a cylindrical body is formed of a polyolefin layer containing carbon black. It is a characteristic raw fabric for light-shielding laminated tubes.

(2) The light-shielding laminate according to (1) above, wherein the outermost layer of the plurality of layers constituting the raw fabric when formed into a tubular body is formed of polyolefin. Raw fabric for tubes.
Here, the outermost layer in the present invention is a layer constituting the surface when the original fabric is formed. In commercially available tubes, an overcoat layer may be applied to the outermost layer for convenience of printing and the like.
(3) Using the raw fabric for light-shielding laminated tube according to (1) or (2), both ends are welded by side seams to form a tubular shape, which corresponds to the outermost layer of the raw fabric of the tubular shape. The layer is formed of a polyolefin layer, and the side seam portion is melt-sealed with a polyolefin layer in which the outermost polyolefin layer and carbon black arranged in at least one layer inside the metal layer are blended at the end of the raw fabric. It is a body portion for a light-shielding laminated tube, characterized in that a stop portion is formed.

(4) A light-shielding laminated tube container having a shoulder bonded to the body of the light-shielding laminated tube according to (3) above.
(5) A raw fabric used for a tubular body having a side seam in a laminated tube, wherein the raw fabric is formed by laminating three or more different materials, and among the three layers. The intermediate layer is made of a metal material, the outermost layer when molded into a tubular body is formed of a polyolefin layer, and at least one layer inside the metal layer when molded into a tubular body. After rolling the raw fabric for a long laminated tube formed of a polyolefin layer containing carbon black into a roll shape, the roll-shaped raw fabric is sequentially unwound, wound around a mold, and then both ends are overlapped. When the raw fabric is bonded by a side seam and processed into a cylindrical shape, a light-shielding property is characterized in that a concave groove is formed at the contact portion of the mold in which the heat source is pressed against the raw fabric from the outside. This is a method for manufacturing a body for a laminated tube.

According to the present invention, by providing a concave groove on the surface of the mold, a resin pool can be formed near the end portion of the aluminum foil, and a melt-sealed portion can be efficiently formed.
(6) The outermost layer when molded into the tubular body of the original fabric is a polyolefin layer, and at least one layer inside the metal layer when molded into the tubular body is made of a polyolefin layer containing carbon black. It is formed, and when the outermost layer and the polyolefin layer containing carbon black are melt-stretched during processing by the side seam, the outermost layer of the polyolefin layer and the polyolefin layer containing carbon black are formed on both inner and outer ends of the side seam portion. The method for manufacturing a body portion for a light-shielding laminated tube according to (5) above, which comprises a step of forming a melt-sealed portion.

Here, in order to form the melt-sealed portion, it is important to compress the stacked raw fabrics while applying heat. By compressing, the molten resin is poured to form a melt-sealed portion. For compression ratio,
Compressibility: 100 x side seam thickness / (original fabric thickness x 2) = 65-85%
Is desirable.
If the compression ratio is less than 65%, too much heat is applied and there is a concern of overwelding. On the other hand, when the compressibility exceeds 85%, there is a concern that the heat is insufficient and the resin is insufficiently melted out.

By adopting the body portion using the raw fabric for the light-shielding laminated tube of the present invention for the body portion of the laminated tube container, the end portion of the raw fabric in the side seam portion is covered with the light-shielding material. It has an excellent effect of preventing light from entering the inside of the laminated tube container through the gap between the metal layers of the above with higher accuracy.

It is a partial perspective view which shows the tube container which concerns on this invention. It is a conceptual diagram which shows the side seam part of the laminated tube container body part which is a prior art. It is a conceptual diagram explaining the method of obtaining a tubular body by a side seam. It is a partial cross-sectional view which shows the side seam part of the light-shielding laminated tube container body part which concerns on Embodiment 1 of this invention. It is a partial sectional view for demonstrating the side seam part of the light-shielding laminated tube container body part which concerns on Embodiment 2 of this invention.

Hereinafter, an example of a method for manufacturing a light-shielding laminated tube original fabric, a light-shielding laminated tube body, a light-shielding laminated tube container, and a light-shielding laminated tube body according to the present invention will be described. Since the embodiments and examples shown below are examples of the present invention, even embodiments not described below may belong to the scope of the present invention.
Embodiment 1
FIG. 1 is a partial perspective view for explaining the concept of a tube container in which the original fabric for a light-shielding laminated tube according to the present invention is used. As shown in FIG. 1, the light-shielding laminated tube raw fabric according to the present invention is used as the body 7 of the tube container 10. The tube container 10 is formed by a mouth portion 1, a shoulder portion 2, a tube container body portion 7, and the like. Generally, after the body portion 7 for a tube container is formed into a tubular shape, the mouth portion 1 and the shoulder portion 2 are integrally molded at the same time by a compression method using a head molding machine (not shown). After that, a cap (not shown) is screwed onto the mouth portion 1. Generally, the body 7 for the tube container is externally inserted into the mandrel, and the mandrel is press-fitted into the cavity in which the molten resin made of high-density polyethylene is arranged, thereby corresponding to the mouth 1 and the shoulder 2 of the tube container. To form. Other head molding methods include a method in which the body is inserted into a mold in advance and then molten resin is poured into the mold to integrally mold the head and body, or a pre-molded head and cylinder. There are various methods such as a method in which the body is heat-welded at a high frequency and integrally molded.

As a method of obtaining a tubular body by a side seam, a blank raw fabric for one tube is cut out from a roll-shaped raw fabric for a light-shielding laminated tube, and then the end of the blank is arranged in a mold in a concave shape. A method of obtaining a tubular body by welding the metal layer inside the raw fabric with a high-frequency hammer and welding the innermost layer and the outermost layer of the polyolefin layer (stealing method), and a roll-shaped one. The raw fabric for the light-shielding laminated tube is sequentially unwound, and while it is wound around so that it overlaps with the concave groove provided in the mold, side seams are continuously formed with a high-frequency hammer, and then cut to the length of one. However, there is a method of obtaining a tubular body (vertical method). The vertical method has good production efficiency because the side seams are continuously performed with a high-frequency hammer.

FIG. 4 is a cross-sectional view showing an example of a side seam portion of the body portion for a light-shielding laminated tube according to the first embodiment.
The raw fabric for a light-shielding laminated tube according to the first embodiment is formed by laminating four layers of different materials. Explaining in order from the top of FIG. 4 , the outermost layer 41 is formed of a polyethylene film. Next, the base material 42 is laminated. Such a substrate is formed of a polyethylene terephthalate film. Other such base materials 42 include polybutylene terephthalate film (PBT), polyethylene isophthalate, polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), and 6-nylon (Ny). , 66-Nylon, 11 nylon, MXD6 nylon and the like may be used.

Next, a metal layer 43 is laminated as an intermediate layer. The metal layer 43 is formed of aluminum foil. Next, a polyethylene film containing carbon black is laminated on the layer corresponding to the innermost layer 44.
Therefore, by adopting the raw fabric for the light-shielding laminated tube according to the first embodiment, the end portion of the raw fabric of the side seam portion is covered with the polyethylene resin containing the molten carbon black, so that the laminated tube container is used. It is possible to prevent the intrusion of light from the side seam portion.

Here, for comparison, the configuration of the conventional raw fabric for laminated tubes will be described. FIG. 2 is a conceptual diagram showing a side seam portion of a conventional body portion for a laminated tube container. For comparison, the raw fabric for laminated tubes shown in FIG. 2 also has a laminated structure substantially the same as the original fabric for light-shielding laminated tubes according to the first embodiment. However, the difference is that the innermost layer 34 is formed of a polyethylene film that does not contain carbon black. That is, the conventional raw fabric for laminated tubes shown in FIG. 2 is formed by laminating four layers of different materials. In FIG. 2, when described in order from the top, the outermost layer 31 is formed of a polyethylene film. Next, the base material 32 is laminated. The base material 32 is formed of a polyethylene terephthalate film. Next, a metal layer 33 is laminated as an intermediate layer. The metal layer 33 is formed of aluminum foil. Next, a polyethylene film containing no carbon black is laminated on the layer corresponding to the innermost layer 34.
Here, since the conventional laminated tube raw fabric is shielded from light only by the metal layer 33, it is external from the gap between the metal layer 33 and the metal layer 33 in the side seam portion 30 of the conventional laminated tube body. Light invades the inside.

On the other hand, in the side seam portion 40 of the body portion for the light-shielding laminated tube according to the first embodiment, as shown in FIG. 4 , the end portion of the metal layer 43 on the outside of the container is the outermost layer 41 and the innermost layer 44 in which carbon black is blended. The melt-sealed portion 47 is formed, and the end portion of the metal layer 43 inside the container is also covered with the outermost layer 41 and the inner layer 44 containing carbon black to form the melt-sealed portion 48. There is. Further, the gap between the metal layer 43 and the metal layer 43 is also formed by the outermost layer 41 and the innermost layer 44 in which carbon black is blended.
Therefore, by adopting the tubular body portion molded by using the original fabric for the light-shielding laminated tube of the first embodiment, it penetrates through the gap between the metal layer and the metal layer in the side seam portion of the conventional laminated tube body portion. It is possible to block the light that has been used and prevent the light from entering the inside of the laminated tube container with higher accuracy.

Embodiment 2
FIG. 5 is a cross-sectional view showing an example of a side-seamed state of the raw fabric for a light-shielding laminated tube according to the second embodiment.
The body of the light-shielding laminated tube according to the second embodiment has a configuration in which the body of the light-shielding laminated tube of the first embodiment is coated with an overcoat layer 59. The light-shielding laminated tube raw fabric used has the same configuration as that of the first embodiment. The overcoat layer 59 is made of polyethylene resin. In the overcoat layer 59, after the original fabric is made into a cylinder, the molten polyethylene resin is removed from the mold while passing through the center of a circular mold arranged so as to cover the outer circumference of the cylinder through a certain gap. Formed by extruding. By performing such a process, the step of the side seam becomes smooth, the appearance is improved, and printing can be performed on the side seam portion.

Therefore, in the body portion for the light-shielding laminated tube according to the second embodiment, the gap between the metal layer of the side seam portion 50 and the metal layer is formed of the light-shielding material, and the end portion of the original fabric is formed of the light-shielding material. Since it is completely covered with the melt-sealed portions 57 and 58, the light that has entered through the gap between the metal layers in the side seam portion of the conventional laminated tube body is blocked, and the inside of the laminated tube container is blocked. It is possible to prevent light from entering the area with higher accuracy, and the steps on the side seams become smoother, improving the appearance of the product.

Example 1
The material used for the tube container body 7 is the original fabric for a light-shielding laminated tube according to the present invention. As shown in FIG. 4 , the composition of the raw fabric for the light-shielding laminated tube according to the first embodiment is as follows: from the top, the outermost layer 41 is a polyethylene film, the base material 42 is polyethylene terephthalate (PET), and the metal layer 43 is aluminum foil. The inner layer 44 is laminated with a polyethylene film containing 5% by weight or less of carbon black.
After rolling the raw fabric for the light-shielding laminated tube into a roll shape, the raw fabric was sequentially fed out, and a blank for one tube body (80 mm × 120 mm) was cut out. Next, the blank is wound around the mold so that the longitudinal ends of the cut blank overlap with each other in the groove provided in the mold, and a high-frequency hammer is pressed against the mold to heat-weld the blank to form a cylinder. A body portion (φ25 × 120 mm) was obtained.

Here, a cross - sectional view of the formed side seam portion is shown in FIG. In the present invention, in order to prevent the intrusion of light through the gaps between the overlapping metal layers of the raw fabric, the melt-sealed portions 47 and 48 in which the ends of the side seam portions are wrapped with a polyethylene resin containing carbon black are provided. It is important to form. Here, by providing the groove portion in the mold, it is possible to make it easier to wrap the end portion on the inner layer side (the side that comes into direct contact with the contents), and it becomes easier to form the melt sealing portion 48. Further, by compressing while applying heat, the melted resin flows out, and it becomes easy to form the melt-sealed portion 48. For compression, a compression rate of 65% to 85% is desirable. As described above, by wrapping the end portion of the side seam portion with a polyethylene resin containing carbon black, it is possible to prevent light from entering from the side seam portion with high accuracy.

Example 2
Example 2 is preferably used for cosmetics and the like. The configuration of the tube container body is as shown in FIG.
Similar to the first embodiment, the raw fabric for light-shielding laminating is rolled into a roll shape, then sequentially fed, wound around the lateral side of the raw fabric so as to overlap with the groove of the mold, and continuously welded by a high-frequency hammer. As a result, it was formed into a tubular shape. After making the original fabric into a cylinder, the outermost layer is extruded from the mold while passing through the center of a circular mold arranged so as to cover the outer circumference of the cylinder through a certain gap. It was coated with polyethylene resin. By performing such a process, the step of the side seam becomes smooth, the appearance is improved, and printing can be performed on the side seam portion.
As in Example 1, the intrusion of light into the side seam portion can be prevented with high accuracy by wrapping the end portion of the side seam portion with a polyethylene resin containing carbon black.

Comparative Example 1
A laminated tube was manufactured by the same method as in Example 2 except that the polyethylene film having the original fabric structure shown in FIG. 2 and containing no carbon black in the innermost layer was used. That is, the molten polyethylene resin is removed from the mold while passing through the center of the circular mold arranged so as to cover the side-seamed tubular body portion shown in FIG. 2 from the outer circumference of the cylinder through a certain gap. By extruding, the outermost layer was coated with polyethylene resin.

-Confirmation of light-shielding property of side seam-
The intrusion of light from the side seams of Example 1 (the product of the present invention), Example 2 (the product of the present invention) and Comparative Example 1 (the conventional product) was compared. The method was to shine light on the inside of each tube, then darken the room and visually observe the leakage of light from the side seams. The results are shown in Table 1.
As can be seen from Table 1, in Examples 1 and 2 in which carbon black was blended in the innermost layer, no light leakage from the side seam portion was confirmed. On the other hand, in Comparative Example 1 in which carbon black was not blended in the innermost layer, light leakage from the side seam portion was confirmed.
From the above results, in the container using the original fabric for the light-shielding laminated tube, which is the product of the present invention, the end of the side seam portion is wrapped with the polyolefin layer containing carbon black, so that the light from the side seam portion is emitted. Intrusion can be prevented with high accuracy.

1 mouth
2 Shoulder 7 Body 8 Side seam 10 Laminated tube container 31, 41, 51 Outer layer 32, 42, 52 Base material 33, 43, 53 Metal layer 34 Inner layer without carbon black 44, 54 Carbon black Innermost layer 59 overcoat layer containing

Claims (4)

Using a light- shielding laminated tube raw fabric, both ends are welded by side seams to form a tubular shape, and the light-shielding laminated tube raw fabric is formed by laminating three or more different materials. The polyolefin has a layer formed of a metal material in the intermediate layer among the above three layers, and at least one layer on the inner layer side of the metal layer when formed into a tubular body is blended with carbon black. It is formed by layers, and the layer corresponding to the outermost layer in the tubular original fabric is formed of a polyolefin layer, and at the end of the original fabric in the side seam portion, the outermost layer is inside the polyolefin layer and the metal layer. A body portion for a light-shielding laminated tube, characterized in that a melt-sealed portion is formed by a polyolefin layer containing carbon black arranged in at least one layer of the above. A light-shielding laminated tube container in which a shoulder portion is joined to the body portion of the light-shielding laminated tube according to claim 1. It is a raw fabric used for a tubular body having a side seam in a laminated tube, and the raw fabric is formed by laminating three or more different materials, and the intermediate layer among the three layers is It is made of a metal material, the outermost layer when molded into a tubular body is formed of a polyolefin layer, and at least one layer inside the metal layer when molded into a tubular body is carbon black. After rolling the raw fabric for a long laminated tube formed of the blended polyolefin layer into a roll shape, the roll-shaped raw fabric is sequentially fed out, wrapped around a mold, and both ends are overlapped and bonded by a side seam. When the raw fabric is processed into a cylindrical shape, the body portion for a light-shielding laminated tube is characterized in that a concave groove is formed at the contact portion of the mold in which the heat source body is pressed against the raw fabric from the outside. Manufacturing method. The outermost layer when molded into the tubular body of the original fabric is formed of a polyolefin layer and at least one layer inside the metal layer when molded into the tubular body is formed of a polyolefin layer containing carbon black. By melt-stretching the outermost layer and the polyolefin layer containing carbon black during processing by the side seam, the outermost layer of the polyolefin layer and the polyolefin layer containing carbon black are melt-sealed at both inner and outer ends of the side seam portion. The method for manufacturing a body portion for a light-shielding laminated tube according to claim 3 , further comprising a step of forming the portion.

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