JP7652233B2 - Tube container - Google Patents

Description

The present invention relates to a tube container, and more specifically to a tube container whose outer surface is scratch-resistant when in contact with an external object.

Conventional tube containers, particularly laminated tube containers, are made of polyolefins such as polyethylene for their outer surfaces, and the outer surfaces of such laminated tube containers are rarely printed. Printing is often done on the inner surface of a polyethylene terephthalate film or the like that serves as an intermediate layer. See Patent Documents 1 and 2.
The surface of the unprinted outer polyethylene layer is soft and is easily scratched when rubbed against an external hard object.

In manufacturing lines for packaging products in which tube containers are filled and sealed, the tube containers must be transported at all times, including when transporting empty tube containers, during the filling and packaging process, and after the filling and packaging process is complete, and they come into contact with guides and other objects on the transport conveyor, resulting in friction. Furthermore, within the filling and packaging equipment, the tube containers may come into contact with fixtures that hold them in place at each process within the equipment, or come into contact with various handling devices during transport between processes, which can damage the outer surface of the tube containers.

JP 2005-144812 A JP 2005-178851 A

The present invention was made in consideration of these circumstances, and aims to provide a tube container that improves the scratch resistance of the outer surface of the tube container, and that maintains its aesthetic appearance without being scratched during the filling and packaging process of the tube container as described above.

The tube container of the present invention is a tube container consisting of a body having a pair of bonded ends and a shoulder portion, and is characterized in that the laminate of the body is made up of at least a first base material layer, a second base material layer, and a second sealant layer laminated in this order from the outer surface to the inner surface, and further a protective layer is provided on the entire surface or at least a part of the outer surface of the first base material layer.

By providing a protective layer on the outer surface of the cylindrical body of the tube container, scratch resistance is improved. In addition, the coefficient of friction of the outer surface of the cylindrical body of the tube container is reduced.

According to the present invention, it is possible to provide a tube container that improves the scratch resistance of the outer surface of the tube container, and prevents the outer surface of the tube container from being scratched during the filling and packaging process of the tube container, thereby maintaining its aesthetic appeal. In addition, according to the present invention, the friction coefficient of the surface of the cylindrical body of the tube container is low, and it is possible to prevent the tube container from getting caught or falling over on the filling and packaging line for packaged products of the tube container, and the filling and packaging line for packaged products of the tube container can operate stably, which contributes to reducing production costs.

1 is a cross-sectional view of a laminate of a cylindrical body portion of a tube container according to a first embodiment of the present invention. FIG. 4 is a cross-sectional view of a laminate of a cylindrical body portion of a tube container according to a second embodiment of the present invention. FIG. 11 is a cross-sectional view of a laminate of a cylindrical body portion of a tube container according to a third embodiment of the present invention. FIG. 2 is an explanatory diagram of a member of a cylindrical body of a tube container. FIG. FIG. 2 is a front view of a packaged product of a tube container containing a content. This is the original roll for the cylindrical body of a tube container.

The present invention will be described below with reference to the drawings, however, the present invention is not limited to the specifically exemplified embodiments or the various specifically described structures.
In each drawing, the size and ratio of the components may be changed or exaggerated for ease of understanding, and parts that are unnecessary for the explanation or repeated reference numerals may be omitted for ease of viewing.

First embodiment of the present invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tube container according to a first embodiment of the present invention will be described in detail below with reference to the drawings and the like.

First, referring to Figures 4 to 6, we will describe a tube container 30 made using the laminate 10 of the cylindrical body of a tube container according to the present invention.

The tube container 30 has a cylindrical body 31 including a laminate 10 of the cylindrical body of the tube container, and a shoulder 35 and a mouth 36 that are made by providing a synthetic resin to the cylindrical body 31 by a method such as compression molding or injection molding. A cap 37 is attached to the mouth 36 of the tube container 30.

The tube container 30 having such a configuration is obtained through the following manufacturing process.

First, as shown in FIG. 4, a pair of bonded ends (hereinafter, sometimes referred to as both ends) 33A, 33B of the laminate 10 of the cylindrical body of the tube container according to the present invention are overlapped, and the outer and inner surfaces of the overlapped parts are heat-sealed and bonded to form a body bonding part 32, thereby manufacturing a cylindrical body 31. Next, as shown in FIG. 5, the cylindrical body 31 is placed in a mold (not shown), and a shoulder part 35 and a mouth part 36 are formed at one opening (upper side) 34A of the cylindrical body 31 by a method such as compression molding or injection molding. In this way, the shoulder part 35 and the mouth part 36 are integrally molded at one opening (upper side) 34A of the cylindrical body 31, and the tube container 30 is manufactured. Then, a cap 37 is attached to the mouth part 36 of the tube container 30.

Next, an appropriate amount of contents 38, such as mustard paste, wasabi paste, or other contents, is filled into the other opening (lower side) 34B of the cylindrical body 31 of the tube container 30. After that, the opening (lower side) 34B is welded to form a bottom seal 39, and a packaged product 30A is obtained that includes the tube container 30 filled and packaged with the contents 38.

Next, a laminate 10 for the cylindrical body of a tube container from which a tube container 30 is produced will be described with reference to Fig. 1. The laminate 10 for the cylindrical body of a tube container is a laminate having a first base material layer 11 and a first sealant layer 12, both of which have heat sealability, a second base material layer 13, and a second sealant layer 15, which are arranged in this order from the outer surface to the inner surface, as shown in Fig. 1.
A protective layer 16 is provided on the surface of the first base layer 13 .

A protective layer 16 is formed on the outer surface of the first base layer 11 using a coat layer applied by a coater or ink such as OP varnish, and an inner surface printed portion 13A including a desired pattern is formed on the inner surface of the second base layer 13 using printing ink. Note that the inner surface printed portion 13A may be provided on the outer surface of the second base layer 13 using printing ink.

If a picture print is present on the inner surface of the protective layer 16, it is desirable that the protective layer 16 be constructed of a see-through layer so that the picture print can be seen from the outside.

The surface of the first base material layer 11 that forms the protective layer 16 needs to have appropriate irregularities to ensure adhesion of the ink, etc. The first sealant layer 12 is often prepared in advance as a film, and the surface may be too smooth, resulting in poor adhesion of the ink, etc. when the ink, etc. is applied to the surface. In particular, when the film used for the first sealant layer 12 is produced by the inflation method, the surface tends to be easily smoothed.

In the case where the adhesion between the first sealant layer 12 and the protective layer 16 is poor as described above, a first base material layer 11 can be bonded onto the first sealant layer 12 to provide the surface of the first base material layer 11 with appropriate irregularities. The arithmetic mean height (Sa) of the surface of the first base material layer 11 is preferably 0.1 to 1.0 μm. If it is less than 0.1 μm, there is a risk that the ink adhesion will be poor, and if it exceeds 1.0 μm, there is a risk that the ink will become mottled and the effect of protecting the surface will be poor. In addition, the material of the first base material layer 11 is preferably low-density polyethylene in terms of cost and processability.
When flexographic printing was performed on an LLDPE film with an arithmetic mean height (Sa) of 0.08 μm, the ink adhesion was poor and the print peeled off in part of the pattern.

In addition, the first sealant layer 12 and the second base layer 13 are joined by dry lamination, and the first base layer 11 is formed on the surface of the first sealant layer 12 by extrusion lamination. Furthermore, the second base layer 13 and the second sealant layer 15 are joined by dry lamination.

In this specification, the terms "outer surface" and "inner surface" refer to the "outer surface" and "inner surface" when the tube container 30 is produced using the laminate 10 of the cylindrical body of the tube container. Additionally, the terms "upper side" and "lower side" refer to the side of the mouth of the tube container 30 when the mouth 36 and cap 37 are facing upward, and the "upper side" refers to the side opposite the mouth.

Next, we will explain the materials used for each part that makes up the laminate 10 of the cylindrical body of the tube container.

The first base layer 11, the first sealant layer 12, and the second sealant layer 15 may contain, for example, polyethylene (PE). Specifically, the first base layer 11, the first sealant layer 12, and the second sealant layer 15 may be made of the following materials:

The first base layer 11, the first sealant layer 12, and the second sealant layer 15 may be made of any material that can be melted and fused together by heat. For example, low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), polypropylene (PP), ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, acid-modified polyolefin resins obtained by modifying polyolefin resins such as polyethylene or polypropylene with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, and the like, polyvinyl acetate resins, polyester resins, polystyrene resins, and the like, may be used.

The second base layer 13 may be a polyethylene terephthalate (hereinafter, abbreviated as PET), and the PET layer 13 may be printed to provide an inner surface printed portion 13A made of printing ink. The second base layer 13 also maintains the rigidity of the tube container.

Instead of using a PET layer as the second base layer 13, a nylon layer may be used, or a PET layer having a metal vapor deposition film on at least one side and gas barrier properties may be used, or a nylon layer having a metal vapor deposition film on at least one side and gas barrier properties may be used.

A PET layer having a silica vapor deposition film on at least one side and gas barrier properties may also be used, or a nylon layer having a silica vapor deposition film on at least one side and gas barrier properties may also be used.

A PET layer having an aluminum oxide vapor deposition film on at least one side and gas barrier properties may also be used, or a nylon layer having an aluminum oxide vapor deposition film on at least one side and gas barrier properties may also be used.

When a nylon layer is used, it often has superior mechanical strength to a PET layer.
Moreover, films provided with various vapor-deposited films have better gas barrier properties than substrate films.

Next, we will explain the protective layer 16 provided on the outer surface of the first base layer 11, which has heat sealability, and the inner surface printed portion 13A provided on the inner surface of the second base layer 13.

As shown in FIG. 7, the protective layer 16 is provided in the laminate 10 of the cylindrical body of the tube container in an area other than the pair of bonded ends 33A, 33B. The reason for providing the protective layer 16 in an area other than the pair of bonded ends 33A, 33B is that the pair of bonded ends 33A, 33B are the parts where the outer and inner surfaces of the pair of bonded ends 33A, 33B overlap and join with each other when the tube container 30 is manufactured.

Therefore, the protective layer 16 is not provided on the pair of bonded ends 33A, 33B of the laminate 10 of the cylindrical body of the tube container.
However, if the protective layer 16 has properties such as not interfering with the formation of the body attachment and not being destroyed during heat sealing, the protective layer 16 may be provided on either one or both of the pair of bonding ends 33A, 33B.
The protective layer 16 may be partially removed or formed in areas other than the pair of bonding ends 33A and 33B as required.

On the other hand, the inner surface printing portion 13A provided on the inner surface of the second base layer 13 is printed on the second base layer 13, which is smooth and has excellent transparency, making it possible to produce printing with excellent cosmetic properties.

In addition, FIG. 7 shows the original roll 10A of the laminate of the cylindrical body portions of multiple continuous tube containers before being cut along the cutting line L.

Next, the manufacturing method for the laminate 10 of the cylindrical body of the tube container will be explained with reference to Figure 1.

First, printing is applied to the inner surface of the second base layer 13, and thus an inner surface printed portion 13A made of printing ink is provided on the inner surface of the second base layer 13.

Next, the second sealant layer 15 is bonded to the inner surface of the second base layer 13 by dry lamination (DL).

Next, the first sealant layer 12 is bonded to the outer surface of the second base layer 13 by dry lamination.

Next, the first base material layer 11 is formed on the outer surface of the first sealant layer 12 by extrusion lamination.

Next, the protective layer 16 is applied to the outer surface of the first base material layer 11 by printing, and thus the protective layer 16 made of printing is provided on the outer surface of the first base material layer 11 .
In this manner, a laminate 10 for the cylindrical body of a tube container is obtained.

The laminate 10 of the cylindrical body of the tube container obtained in this manner is wound into a cylindrical shape, and as described above, both end portions 33A, 33B are overlapped, and the outer and inner surfaces of the laminate 10 of the cylindrical body of the tube container are heat-sealed at both end portions 33A, 33B to form the body attachment portion 32 and produce the cylindrical body portion 31.
In this case, the first base material layer 11 and the first sealant layer 12 provided on the outer surface side of the laminate 10 of the cylindrical body of the tube container and the second sealant layer 15 provided on the inner surface side are melted and joined to obtain the cylindrical body 31.

In the above, the body attachment portion 32 is formed by overlapping, but the end faces of both ends 33A, 33B may be butted together and joined. Furthermore, the joining line formed by butting together as described above may be protected by applying a film to the inner or outer surface of the cylindrical body portion 31.
The inner end 33B may be protected by a process such as taping or folding the end 33B toward the outside of the container (hemming).

Next, the open portion (upper side) 34A of the cylindrical body 31 is inserted into a mold (not shown), and a shoulder portion 35 and a mouth portion 36 are formed in the open portion (upper side) 34A of the cylindrical body 31 using a method such as compression molding or injection molding, thereby obtaining a tube container 30 (see Figures 4 and 5).

Next, a cap 37 is attached to the mouth 36 of the tube container 30 manufactured as described above, and a plurality of tube containers 30 with the caps 37 attached are stored together in a cardboard box. After that, the plurality of tube containers 30 with the caps 37 attached are transported together in the cardboard box.

As described above, according to the first embodiment of the present invention, the protective layer 16 is provided in an area other than the pair of bonded ends 33A, 33B, and the protective layer 16 has excellent scratch resistance, so that a tube container 30 with excellent scratch resistance can be manufactured.

Second embodiment of the present invention
Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment shown in FIG. 2 , a gas barrier layer 14 is attached to the second base layer 13 of the laminate 10 in the cylindrical body portion of a tube container by dry lamination, and a second sealant layer 15 is joined to this gas barrier layer 14 by dry lamination.
In the second embodiment shown in FIG. 2, the configuration other than that described above is similar to that of the first embodiment shown in FIGS. 1 and 4 to 6. The same parts as those in the first embodiment are denoted by the same reference numerals and detailed descriptions thereof are omitted.

In the second embodiment, the laminate 10 of the cylindrical body of the tube container further has a gas barrier layer 14 disposed between the second base material layer 13 and the second sealant layer 15. As the gas barrier layer 14, a metal foil, or a film having a base material film and a vapor deposition film vapor-deposited on the base material film, or a film having gas barrier properties in the material itself can be used.

Specifically, an example of the metal foil used as the gas barrier layer 14 is aluminum foil. Aluminum foil is a material that has excellent gas barrier properties, light blocking properties, and excellent cost performance.

As the substrate film on which the vapor deposition film is provided, films or sheets of various resins such as polyethylene resins, polypropylene resins, cyclic polyolefin resins, fluorine resins, polystyrene resins, acrylonitrile-styrene copolymers (AS resins), acrylonitrile-butadiene-styrene copolymers (ABS resins), polyvinyl chloride resins, fluorine resins, poly(meth)acrylic resins, polycarbonate resins, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyamide resins such as various nylons, polyimide resins, polyamideimide resins, polyarylphthalate resins, silicone resins, polysulfone resins, polyphenylene sulfide resins, polyethersulfone resins, polyurethane resins, acetal resins, cellulose resins, and others can be used.

In the present invention, it is particularly preferable to use PET as the base film on which the vapor-deposited film is provided, as this has a good balance between performance and cost.
In the present invention, it is preferable to use nylon as the base film on which the vapor-deposited film is provided, particularly in situations where mechanical strength is required.

In addition, a silica vapor deposition film can be used as the vapor deposition film vapor-deposited on the base film, and a silica vapor deposition PET containing a base film and a silica vapor deposition film can be used as the gas barrier layer 14.

In addition, an aluminum vapor deposition film can be used as the vapor deposition film deposited on the base film, and aluminum vapor deposition PET containing the base film and the aluminum vapor deposition film can be used as the gas barrier layer 14.

In addition, an aluminum oxide (alumina) vapor deposition film can be used as the vapor deposition film vapor-deposited on the base film, and an alumina PET containing a base film and an aluminum oxide (alumina) vapor deposition film can be used as the gas barrier layer 14.

Films whose material itself has gas barrier properties include ethylene-vinyl alcohol copolymer resin (EVOH), nylon MXD6, polyacrylonitrile (PAN), polyvinylidene chloride (PVDC), etc., and these films can be used as the gas barrier layer 14.

In the above first and second embodiments, an example is shown in which the first sealant layer 12 is provided between the first base material layer 11 and the second base material layer 13. However, if the first base material layer 11 has sufficient heat sealing function, the first sealant layer 12 does not necessarily have to be provided.
Other components not described are similar to those in the first embodiment.

In the second embodiment, the printed second base layer 13 and the gas barrier layer 14 are separate bodies, but if the gas barrier layer 14 is suitable for printing, the gas barrier layer 14 may be printed and the second base layer 13 may be omitted. In such a case, it is possible to reduce costs by omitting the second base layer 13.

The printability described above will now be explained. When reverse printing is performed on the inner surface of the gas barrier layer 14, the gas barrier layer 14 must be transparent. In addition, since tension is applied to the gas barrier layer 14 during the printing process, it is required that the gas barrier layer 14 has a certain strength and is low in elongation.

Conversely, the advantages of making the printed second base layer 13 and the gas barrier layer 14 separate will now be explained. In applications that require particularly high gas barrier properties, it is desirable not to print on the gas barrier layer 14, as there is a risk that the deposition layer will be damaged during the printing process. For this reason, it is desirable to make the second base layer 13 and the gas barrier layer 14 separate.

<Third embodiment of the present invention>
Next, a third embodiment of the present invention will be described with reference to FIG.
In order to improve the design, a design improving layer 17 made of milky white polyethylene is provided on the inner surface side of the printed second base layer 13. The design improving layer 17 may be in direct contact with and bonded to the second base layer 13, or may be bonded to the second base layer 13 via a light-transmitting layer (not shown).

In addition, in order to improve the bonding strength between the gas barrier layer 14 and each layer that contacts the front and back surfaces of the gas barrier layer 14, adhesive layers 18A and 18B are provided on the front and back surfaces of the gas barrier layer 14. In particular, when aluminum foil is used for the gas barrier layer 14, it is desirable to provide an adhesive layer in order to improve the bonding strength of the bonding interface of the aluminum foil.

The layer that ensures the gas barrier property is appropriately selected from the various films described above, depending on the performance required for the tube container, cost, and the like.
Other components not described are similar to those in the first and second embodiments.

Next, we will explain specific examples of the present invention.

Example 1
Example 1 corresponds to the above-mentioned first embodiment.
As the laminate 10 for the cylindrical body of the tube container, a laminate 10 having the following layer structure was prepared.

Varnished layer 16 / LDPE layer 11 (20 μm) / LLDPE layer 12 (100 μm) / PET layer 13 (12 μm) / Inner printed area 13A / LLDPE layer 15 (210 μm)

Here, the varnish coating layer 16 is applied to the surface of the LDPE layer 11 by flexographic printing. The LDPE layer 11 is made of low density polyethylene and constitutes the first base material layer 11. The LLDPE layer 12 is made of linear low density polyethylene and constitutes the first sealant layer 12. The PET layer 13 is made of polyethylene terephthalate (PET) and constitutes the second base material layer 13. The LLDPE layer 15 is made of linear low density polyethylene and constitutes the second sealant layer 15.
The varnish coating layer 16 can also be applied by gravure printing or with a coater.

The manufacturing method of the laminate 10 of Example 1 is explained.

When manufacturing the laminate 10, first, the inner surface of the PET film (12 μm) that would become the PET layer 13 was printed with a gravure printer as reverse printing so that the correct pattern would be printed when viewed from the outer surface of the PET film.

Next, an LLDPE film 12 (100 μm) that would become the first sealant layer 12 was dry laminated to the outer surface of the PET film that would become the PET layer 13 printed in the above procedure, and an LLDPE film 15 (210 μm) that would become the second sealant layer 15 was dry laminated to the inner surface using a dry laminator.

Next, molten LDPE was extruded into a film using an extruder onto the outer surface of the LLDPE layer 12 on the outer side of the laminate formed by the above procedure, forming an LDPE layer 11 (20 μm) that would become the first base layer 11. The surface of the cooling roll that cools and solidifies the molten film-like LDPE layer 11 has an appropriate uneven shape, so that the surface of the LDPE layer 11 has an uneven shape suitable for printing.

Next, ink was applied to the outer surface of the LDPE layer 11 on the outer side of the laminate laminated in the above-mentioned procedure using a flexographic printer to form a varnished layer 16. The ink used was an ultraviolet radiation curable varnish (OP varnish, composition: 75-85% by weight of photosensitive monomer, 15-25% by weight of photopolymerization initiator, 1-10% by weight of auxiliary agent, less than 1% by weight of 2,6-di-t-butyl-4-methylphenol), and when the laminate with the protective layer 16 made of ultraviolet radiation curable varnish passed through the ultraviolet radiation unit provided on the discharge side of the flexographic printer, the varnish hardened, increasing the hardness of the surface of the protective layer 16, improving scratch resistance, and further reducing the coefficient of friction.

To improve printability and ink adhesion in each of the above printing processes, and to improve laminate strength in each lamination process, the surface of each layer may be subjected to a surface treatment such as corona treatment or coated with an anchor coating agent as appropriate.

For the tube container 30 in Example 1, the bonding strength between the inside of the pair of bonded ends 33A and the outside of 33B, and the bonding strength between the laminate 10 of the cylindrical body of the tube and the shoulder portion 35 were measured. Both of the above bonding strengths were sufficient and at a level that would not cause any problems for the tube container.

Example 2
Example 2 corresponds to the above-mentioned second embodiment.
As the laminate 10 for the cylindrical body of the tube container, a laminate having the following layer structure was prepared.

Varnished layer 16 / LDPE layer 11 (20 μm) / LLDPE layer 12 (100 μm) / PET layer 13 (12 μm) / inner surface printed part 13A / (vapor deposition surface) VM-PET layer 14 (12 μm) / LLDPE layer 15 (210 μm).

Here, the varnish coating layer 16 is applied to the surface of the LDPE layer 11 by flexographic printing. The LDPE layer 11 is made of low-density polyethylene and constitutes the first base layer 11. The LLDPE layer 12 is made of linear low-density polyethylene and constitutes the first sealant layer 12. The PET layer 13 is made of polyethylene terephthalate (PET) and constitutes the second base layer 13. An inner printed portion 13A is formed on the inner side of the second base layer 13 by gravure printing. The VM-PET layer 14 is made of an aluminum-deposited polyethylene terephthalate layer and constitutes the gas barrier layer 14. The vapor deposition surface of the VM-PET layer 14 is on the outside. By placing the vapor deposition surface on the outside, attacks by the contents on the vapor deposition surface are mitigated compared to when the vapor deposition surface is on the inside, and deterioration of the vapor deposition film may be reduced. Furthermore, the LLDPE layer 15 is made of linear low-density polyethylene and constitutes the second sealant layer 15.

A method for manufacturing the laminate 10 of the second embodiment will be described.
In producing the laminate 10, first, a pattern was printed on the inner surface of a PET film (12 μm) that would become the PET layer 13 using a gravure printer as reverse printing so that the pattern would be a regular pattern when viewed from the outer surface side of the PET film.

Next, a VM-PET layer 14 (12 μm) that will become the gas barrier layer 14 is applied to the inner surface of the PET film printed in the above procedure, and then an LLDPE film 15 (210 μm) that will become the second sealant layer 15 is dry laminated (DL) to the inner surface of the gas barrier layer 14 using a dry laminator. The vapor deposition surface of the VM-PET layer 14 is on the outside.

Next, the LLDPE film 12 (100 μm) that will become the first sealant layer 12 is dry laminated using a dry laminator onto the outer surface of the PET film that will become the PET layer 13 of the laminate formed using the above procedure.

Next, molten LDPE is extruded into a film using an extruder onto the outer surface of the LLDPE film 12 on the outer side of the laminate formed by the above procedure, to form the LDPE layer 11 (20 μm) that will become the first base layer 11. The surface of the cooling roll that cools and solidifies the molten film-like LDPE layer 11 has an appropriate uneven shape, so that the surface of the LDPE layer 11 has an uneven shape suitable for printing.

Next, ink is applied to the outer surface of the LDPE film 11 on the outer side of the laminate formed by the above procedure using a flexographic printer to form a varnished layer 16. The ink used is an ultraviolet-curable varnish (the same as in Example 1), and when the laminate with the protective layer 16 made of ultraviolet-curable varnish passes through an ultraviolet irradiation section provided on the discharge side of the flexographic printer, the varnish hardens, increasing the hardness of the surface of the protective layer 16, improving scratch resistance, and further reducing the coefficient of friction.

For the tube container 30 in Example 2, the bonding strength between the pair of bonded ends, the inside of 33A and the outside of 33B, and the bonding strength between the laminate 10 of the cylindrical body of the tube and the shoulder 35 were measured. Both of the bonding strengths were sufficient and at a level that would not be problematic for a tube container.

Example 3
Example 3 corresponds to the above-mentioned third embodiment.
As the laminate 10 for the cylindrical body of the tube container, a laminate having the following layer structure was prepared.

Varnished layer 16 / LDPE layer 11 (30 μm) / LLDPE 12A (60 μm) / LDPE layer 12B (20 μm) / PET layer 13 (12 μm) / inner surface printed part 13A (anchor coat) / milky white LLDPE layer 17 (100 μm) / EMAA layer 18A (20 μm) / aluminum foil 14 (10 μm) / EMAA layer 18B (30 μm) / LLDPE 15 (100 μm).

Here, the varnish coating layer 16 is applied to the surface of the LDPE layer 11 by flexographic printing. The LDPE layer 11 is made of low-density polyethylene and constitutes the first base layer 11. The LLDPE layer 12 is made of linear low-density polyethylene and constitutes the first sealant layer 12. The PET layer 13 is made of polyethylene terephthalate (PET) and constitutes the second base layer 13. An inner surface printed portion 13A is formed on the inside of the second base layer 13 by gravure printing. The milky white LLDPE layer 17 is made of linear low-density polyethylene colored milky white and constitutes the design improving layer 17. The EMAA layer 18A is made of ethylene-methacrylic acid copolymer and constitutes the adhesive layer 18A. The aluminum foil 14 constitutes the gas barrier layer 14. The EMAA layer 18B is made of ethylene-methacrylic acid copolymer and constitutes the adhesive layer 18B. Furthermore, LLDPE15 is made of linear low-density polyethylene and constitutes the second sealant layer 15.

The manufacturing method of the laminate 10 of Example 3 is explained.

When manufacturing the laminate 10, first, the inner surface of the PET film (12 μm) that would become the PET layer 13 was printed with a gravure printer as reverse printing so that the correct pattern would be printed when viewed from the outer surface of the PET film.

Next, a previously prepared film that will become the milky white LLDPE layer 17 is dry laminated using a dry laminator onto the inner surface of the PET film that will become the PET layer 13 printed in the above procedure.

Next, the molten EMAA layer 18A is extruded into a film shape using an extruder onto the inner surface of the LLDPE layer 17 of the laminate formed by the above procedure, and while the EMAA layer 18A that will become the adhesive layer 18A is in a molten state, the aluminum foil 14 that will become the gas barrier layer 14 is bonded to the EMAA layer 18A. The EMAA layer 18A is then cooled and solidifies and adheres to the aluminum foil 14.

Following the above process, molten EMAA layer 18B is extruded into a film on the inner surface of the aluminum foil 14, and while the EMAA layer 18B, which becomes adhesive layer 18B, is in a molten state, a previously prepared LLDPE film, which becomes the LLDPE layer 15, is bonded to it. The EMAA layer 18B is then cooled and solidifies and adheres to the LLDPE layer 15. EMAA has stronger adhesion to metals than LDPE, and is effective in improving the laminate strength of the aluminum foil.

Next, the outer surface of the PET film of the laminate formed by the above procedure is coated with an anchor coat using a polyurethane-based anchor coating agent, and then the molten LDPE layer 12B is extruded into a film using an extruder, and while the LDPE layer 12B that will become the adhesive layer 12B is in a molten state, a previously prepared film that will become the LLDPE layer 12A is bonded to the outer surface side of the LDPE layer 12B. The LDPE layer 12B is then cooled, solidifying and adhering to the LLDPE layer 12A.

Following the above process, the molten LDPE layer 11 is extruded into a film on the outer surface of the LLDPE layer 12A, and then cooled to form the LDPE layer 11 (20 μm) that becomes the first base layer 11. The surface of the cooling roll that cools and solidifies the molten LDPE layer 11 in a film form has an appropriate uneven shape, so that the surface of the LDPE layer 11 has an uneven shape suitable for printing.

Next, ink is applied to the outer surface of the LDPE layer 11 on the outer side of the laminate formed by the above procedure using a flexographic printer to form a varnished layer 16. The ink used is an ultraviolet-curable varnish (the same as in Example 1), and when the laminate with the protective layer 16 made of ultraviolet-curable varnish passes through an ultraviolet irradiation section provided on the discharge side of the flexographic printer, the varnish hardens, increasing the hardness of the surface of the protective layer 16, improving scratch resistance, and further reducing the coefficient of friction.

For the tube container 30 in Example 3, the bonding strength between the pair of bonded ends, the inside of 33A and the outside of 33B, and the bonding strength between the laminate 10 of the cylindrical body of the tube and the shoulder 35 were measured. Both of the bonding strengths were sufficient and at a level that would not be problematic for a tube container.

Comparative Example
The comparative example is a tube container manufactured by the same method and with the same configuration as in Example 3, except that it does not have the protective layer 16 made of the varnish coating layer 16 .

(Comparison and evaluation of various examples and comparative examples)
For the samples of the various examples and the samples of the comparative examples, a friction coefficient measurement test, a friction test (scratch resistance test), and a transportation test were carried out.

(Measurement of surface friction coefficient)
The coefficient of friction of the surfaces of the various examples and comparative examples was measured, and the results are shown in Table 1.
The static friction coefficient and the dynamic friction coefficient were measured in accordance with JIS K-7125 using a measuring instrument TR-2 manufactured by Toyo Seiki Seisakusho Co., Ltd. The number of tests was n=3, and the test speed was 100 mm/min.

The measurement results are shown in Table 1.
The surface of the laminate of the cylindrical body of the tube container, which is described in the item of friction target surface in Table 1, was subjected to friction coefficient measurement using the same combination of materials, and friction between tubes during transportation of the tube container was assumed.
The metal surface described in the section on friction target surface is assumed to come into contact with metal parts during the transport process of filling and packaging tube containers. The metal surface used in the friction measurement this time is stainless steel, and has a flat, smooth surface like a mirror.

From Table 1, the following can be seen:
In the case where the friction target surface is the surface of the laminate of the cylindrical body of the tube container, the static friction coefficient and the dynamic friction coefficient are smaller in the various examples than in the comparative example, and the frictional force generated on the tube container surface is smaller in the various examples, so the surface is less damaged. As a result, the surface of the various examples is less likely to be scratched during transportation of the tube container.

When the friction target surface is a metal surface, the static and dynamic friction coefficients are smaller in the various Examples than in the Comparative Example, and the frictional force generated on the tube container surface is smaller in the various Examples, resulting in less damage to the surface. As a result, the surfaces of the various Examples are less likely to be scratched when they come into contact with metal parts during the transport process when filling and packaging the tube containers.

In addition, in a type of conveyor chain with a plate on top, the tops of the caps of tube containers are placed face down on the plate and transported only by the frictional force between the tops of the caps and the conveyor plate, with the cylindrical bodies of the tube containers being regulated by metal guides attached to the transport conveyor. For tube containers with a small coefficient of friction in the cylindrical bodies, the frictional force exerted by the guide on the cylindrical bodies of the tube containers is reduced, so tube containers are less likely to get caught or fall over on the line, resulting in less disruption to production.

(Evaluation of surface scratch resistance)
The scratch resistance of the surface was evaluated by a Gakushin friction test (JIS L-0849). The measuring device was FR-2 manufactured by Suga Test Instruments Co., Ltd.

When conducting a friction test between the laminates, a strip-shaped (30 mm wide) laminate of the cylindrical body part of a tube container was fixed to the lower test piece stand, and a strip-shaped (30 mm wide) laminate of the cylindrical body part of a tube container made of the same material was attached to the upper friction element.
When conducting a friction test between the laminate and a metal plate, a metal plate was attached to the upper friction element and the friction element was slid. The metal plate used in the Gakushin friction test this time was stainless steel, and had a smooth mirror-like surface.
The weight used was 200 g.

The above Gakushin friction test was repeated 100 and 300 times, and the number of scratches that occurred on the surface of the laminate as a result was visually counted. Samples with 20 or more scratches were rated as × (bad), samples with 10 to less than 20 scratches were rated as △ (slightly bad), and samples with less than 10 scratches were rated as ○ (good).

As with the measurement of the coefficient of friction, the coefficient of friction was measured using the same combination of materials as the surface of the laminate of the cylindrical body of the tube container described in the section on friction target surfaces, simulating the friction between tubes when the tube container is transported.
The metal surface in the friction target surface is assumed to come into contact with metal parts such as guide parts during the conveying process when filling and packaging tube containers.

From Table 2, the following can be seen:
In a friction test of the surfaces of the laminated bodies of the cylindrical body of the tube container against each other, the comparative example was △ (slightly poor) after 100 frictions and × (poor) after 300 frictions. In addition, the various examples were ○ (good) after 100 frictions and ○ (good) after 300 frictions.
From this, it can be seen that the various Examples are less susceptible to scratches when the tube containers are rubbed against each other, and have improved scratch resistance compared to the Comparative Example.

In a friction test between the surface of the laminate of the cylindrical body of the tube container and a metal surface, the comparative example was ◯ (good) after 100 friction cycles and Δ (slightly poor) after 300 friction cycles. In Example 3, the comparative example was ◯ (good) after 100 friction cycles and ◯ (good) after 300 friction cycles.
This shows that the various Examples are less susceptible to scratches when the surface of the tube container rubs against a metal part, and have improved scratch resistance compared to the Comparative Example.

(Evaluation of scratch resistance through actual transportation testing)
An actual transportation test was carried out on the samples of Example 3 and Comparative Example. The prepared samples were filled with water to prepare packaged products, and 10 of each were packed in a cardboard box and transported round trip between Shinjuku-ku, Tokyo and Kyotanabe-shi, Kyoto Prefecture by home delivery (land route). The one-way distance was about 475 km, and the total distance was about 950 km.

After arrival, the cardboard box was opened and the tube container was visually inspected. The number of scratches on the surface of the cylindrical body of the tube container was counted. Tube containers with 20 or more scratches were rated as × (bad), tube containers with 10 to less than 20 scratches were rated as △ (slightly bad), and tube containers with less than 10 scratches were rated as ○ (good).

The results are shown in Table 3.
The damage to each of the 10 tube containers was similar and there was no difference.

The following can be seen from Table 3.
The sample of the comparative example had many scratches and was poor in appearance, whereas the sample of the example 3 had less than 10 scratches and was good.
From this, it was found that in the actual transportation test, the tube container of Example 3 had excellent scratch resistance and was able to maintain its aesthetic appeal.

According to the present invention, a tube container can be provided in which the surface of the laminate of the cylindrical body of the tube container has a low coefficient of friction, which prevents the tube container from getting caught or falling over on the filling and packaging line for packaged products of the tube container, allowing the filling and packaging line for packaged products of the tube container to operate stably, contributing to improved quality and reduced production costs. In addition, because the outer surface of the tube container is not easily scratched, it is possible to display aesthetically pleasing products in stores, stimulating purchasing desire.

10 Laminated body of a cylindrical body part of a tube container 10A Raw roll of laminated body of a cylindrical body part of a tube container 11 First base layer 12 First sealant layer 12A Part of the first sealant layer 12B Part of the first sealant layer (also serves as an adhesive layer)
13 Second base layer 13A Inner surface printed portion 14 Gas barrier layer 15 Second sealant layer 16 Protective layer 17 Design improving layer 18A Adhesive layer 18B Adhesive layer 30 Tube container 30A Packaged product of tube container 31 Cylindrical body portion 32 Body attachment portion 33A Bonded end portion 33B that becomes the outer side when the body is attached Bonded end portion 34A that becomes the inner side when the body is attached Opening (upper side)
34B opening (lower side)
35 Shoulder 36 Mouth 37 Cap 38 Contents 39 Bottom seal

L cutting line

Claims (1)

A tube container comprising a body portion having a pair of joined ends and a shoulder portion,
The laminate of the body portion includes at least a first base material layer, a first sealant layer, a second base material layer, and a second sealant layer laminated in this order from the outer surface to the inner surface,
the first substrate layer is low density polyethylene, the first sealant layer is linear low density polyethylene,
the first substrate layer and the first sealant layer are adjacent to each other;
The thickness of the first base layer is smaller than the thickness of the first sealant layer,
A protective layer is provided on the entire surface or at least a part of the outer surface of the first base material layer,
The protective layer is a printing ink containing an ultraviolet radiation curable varnish,
The arithmetic mean height (Sa) of the surface of the first base layer is 0.1 to 1.0 μm.

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