JP7848829B2 - Laminate, tube container, and tube container with cap - Google Patents

Description

This disclosure relates to laminates, tube containers, and tube containers with caps.

Conventionally, laminated tube containers are known as tube containers (see, for example, Patent Document 1). Patent Document 1 discloses a tube container in which the body forming the content storage space has a laminated structure made of multiple materials, characterized in that the laminated structure comprises a barrier layer having metal foil and a highly reflective layer provided on the outside of the barrier layer and having a metal vapor-deposited film formed on at least one side of the base material.

Japanese Patent Publication No. 2020-19493

Incidentally, in recent years, there has been a demand to reduce the amount of resin used in order to reduce environmental impact. Furthermore, in the case of tube containers, friction between tube containers during transport can cause scratches on the outer surface, leading to deterioration of the tube container's appearance. This reduces the aesthetic appeal of the tube container. Therefore, there is a need to suppress this deterioration in the aesthetic appeal of tube containers.

This disclosure has been made with these points in mind, and aims to provide laminates, tube containers, and tube containers with caps that can reduce the amount of resin used while suppressing a decrease in design quality.

The embodiments of this disclosure relate to the following [1] to [8].

[1]
It comprises a wear-resistant varnish layer, a printed layer, a wear-resistant resin layer, an outer sealant layer, and an inner sealant layer, arranged sequentially from the outer surface to the inner surface.
The inner sealant layer comprises a first inner layer, a second inner layer, and a third inner layer, arranged sequentially from the outer surface toward the inner surface.
The density of the material constituting the second inner layer is different from the density of the material constituting the first inner layer and the density of the material constituting the third inner layer.
The density of the inner sealant layer is 0.92 g/ ^m³ or more and 0.93 g/ ^m³ or less.
The coefficient of static friction of the outer surface against the metal is 0.25 or less.
The coefficient of kinetic friction of the outer surface against the metal is 0.20 or less.
The coefficient of static friction of the inner surface against the metal is 0.40 or less.
A laminate in which the coefficient of kinetic friction of the inner surface against a metal is 0.35 or less.

[2]
The laminate according to [1], wherein the inner sealant layer comprises a biomass-derived resin.

[3]
The laminate according to [1] or [2], further comprising a base material layer provided between the outer sealant layer and the inner sealant layer.

[4]
The laminate according to [3], further comprising a barrier layer provided between the base material layer and the inner sealant layer.

[5]
The abrasion-resistant varnish layer comprises an ultraviolet-curable resin, as described in any one of [1] to [4].

[6]
The abrasion-resistant resin layer comprises linear low-density polyethylene, as described in any one of [1] to [5].

[7]
In a tube container,
A body tube formed by overlapping and joining the opposing edges of a laminate described in any one of [1] to [6],
A tube container comprising a head member joined to one end of the body tube.

[8]
In a tube container with a cap,
[7] The tube container described above,
A capped tube container comprising a cap attached to the head member.

According to this disclosure, it is possible to reduce the amount of resin used in tube containers while suppressing a decline in design aesthetics.

Figure 1 is a partial vertical cross-sectional view showing a capped tube container according to this embodiment. Figure 2 is a cross-sectional view showing an example of the layer structure of the laminate according to this embodiment. Figures 3(a) and 3(b) are schematic diagrams illustrating the method for manufacturing a capped tube container according to this embodiment. Figure 4 is a perspective view showing the method for manufacturing a tube container with a cap according to this embodiment. Figures 5(a) and 5(b) are cross-sectional views showing a method for manufacturing a capped tube container according to this embodiment. Figure 6 is a cross-sectional view showing the method for manufacturing a tube container with a cap according to this embodiment. Figure 7 is a cross-sectional view showing an example of the layer structure of the laminate according to Comparative Example 1. Figures 8(a)-8(c) illustrate a jointability evaluation test in the shoulder area according to an example. Figure 9 is a table showing the density and thickness of the inner sealant layer according to the examples. Figure 10 is a table showing the results of static friction coefficient measurement tests, dynamic friction coefficient measurement tests, and rubbing tests according to the examples. Figure 11 is a table showing the results of the joint performance evaluation at the body seal portion and the joint performance evaluation between the body tube and the head member according to the embodiment. Figure 12 is a table showing the biomass content of the inner sealant layer according to the examples.

The following description will refer to the drawings to explain one embodiment. Figures 1 to 6 illustrate one embodiment. The following figures are schematic representations. Therefore, the size and shape of each part are exaggerated as appropriate for ease of understanding. Furthermore, modifications can be made as appropriate without departing from the technical concept. In the following figures, the same parts are denoted by the same reference numerals, and some detailed explanations may be omitted. Also, the numerical values such as dimensions and material names of each component described in this specification are examples of embodiments and are not limited to those; they can be selected and used as appropriate. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and perpendicular, are interpreted to include not only their strict meaning but also substantially equivalent states.

(Tube container with cap)
As shown in Figure 1, the capped tube container 40A according to this embodiment comprises a tube container 40 and a cap 49 attached to a head member 43 of the tube container 40, which will be described later.

(Tube container)
The tube container 40 comprises a body tube 41 which is a laminated tube, and a head member 43 joined to one end 42 of the body tube 41. The body tube 41 has a substantially cylindrical shape overall. This body tube 41 is made of a laminate 10 which is a packaging material for the tube container. In this case, the body tube 41 may be configured such that the outer surface of the packaging material for the tube container (i.e., the outer surface 101 of the laminate 10 described later) faces away from the contents, and the inner surface (i.e., the inner surface 102 of the laminate 10 described later) faces the contents.

The body tube 41 has a body seal portion 44 formed by joining together two pieces of packaging material for the tube container. This body seal portion 44 is formed along the longitudinal direction of the body tube 41. Such a body tube 41 may be obtained, for example, by rolling the packaging material for the tube container into a cylindrical shape, overlapping the opposing edges of the packaging material, and joining them together, for example, by heat sealing.

Furthermore, the body tube 41 has a bottom seal portion 45 where the packaging materials for the tube container are joined together. This bottom seal portion 45 is formed by joining the packaging materials for the tube container near the opening 41B (see Figures 4 and 6) formed at the other end 46 of the body tube 41 after filling an appropriate amount of the contents C.

Referring again to Figure 1, the head member 43 has shoulder portions 47 and mouth portions 48. A cap 49 is attached to the mouth portion 48. The head member 43 is molded, for example, by compression molding. Furthermore, the head member 43 is made from a resin material such as high-density polyethylene (HDPE).

(Laminate)
Next, the layer structure of the laminate 10 will be described. Figure 2 shows an example of the layer structure of the laminate 10 that constitutes the body tube 41. As shown in Figure 2, the laminate 10 comprises an abrasion-resistant varnish layer 21, a printed layer 15, an abrasion-resistant resin layer 22, an outer sealant layer 11, and an inner sealant layer 12, arranged in order from the outer surface 101 to the inner surface 102. The laminate 10 may also further include a base material layer 13 provided between the outer sealant layer 11 and the inner sealant layer 12. Furthermore, the laminate 10 may further include a barrier layer 16 provided between the base material layer 13 and the inner sealant layer 12.

Specifically, as shown in Figure 2, the laminate 10 comprises, in this order, an abrasion-resistant varnish layer 21, a first printed layer (printed layer) 15a, an abrasion-resistant resin layer 22, an outer sealant layer 11, a first adhesive layer 14a, a base layer 13, a second printed layer 15b, a second adhesive layer 14b, a barrier layer 16, an intermediate layer 17, a third adhesive layer 14c, and an inner sealant layer 12. Of these, the inner sealant layer 12 has multiple layers. In the illustrated example, the inner sealant layer 12 has a first inner layer 12a, a second inner layer 12b, and a third inner layer 12c, arranged in order from the outer surface 101 toward the inner surface 102. In this case, the wear-resistant varnish layer 21 constitutes the outer surface 101 of the laminate 10 (the outer surface of the body tube 41), and the third inner layer 12c of the inner sealant layer 12 constitutes the inner surface 102 of the laminate 10 (the inner surface of the body tube 41). Although not shown in the figures, the inner sealant layer 12 may consist of four or more layers.

The following describes each layer of the laminate 10.

<Abrasion-resistant varnish layer>
The abrasion-resistant varnish layer 21 is a layer that protects the first printed layer 15a while improving the abrasion resistance of the laminate 10. The abrasion-resistant varnish layer 21 may contain an ultraviolet-curable resin. This makes it easy to adjust the glossiness (glossy or matte). In addition to an ultraviolet-curable resin, the material constituting the abrasion-resistant varnish layer 21 may also be, for example, OP varnish. The abrasion-resistant varnish layer 21 may be formed by, for example, digital printing such as inkjet, gravure printing, flexographic printing, letterpress printing, or coating with a coater.

As described above, the wear-resistant varnish layer 21 constitutes the outer surface 101 of the laminate 10. In this embodiment, the static friction coefficient of the outer surface 101 against metal is 0.25 or less. Furthermore, the dynamic friction coefficient of the outer surface 101 against metal is 0.20 or less. This prevents scratches on the outer surface of the body tubes 41 even when they rub against each other during filling with contents or when multiple tube containers 40 are packed in cardboard boxes for shipping and storage.

Furthermore, the static and dynamic friction coefficients of the outer surface 101 against the metal may be adjusted by selecting the material used for the wear-resistant varnish layer 21, as described later. The static and dynamic friction coefficients of the outer surface 101 against the metal can also be measured by the following static and dynamic friction coefficient measurement tests.

<<<<Static friction coefficient measurement test / Dynamic friction coefficient measurement test>>>>
The static and dynamic friction coefficients shall be measured according to the method conforming to JIS K 7125:1999. Specifically, the static and dynamic friction coefficients shall be measured in accordance with JIS K 7125:1999, 8.2 "Measurement of films when in contact with metals or other materials". The measuring device may be a TR-2 manufactured by Toyo Seiki Seisakusho Co., Ltd. In this case, first, the measuring device and the laminate shall be stabilized in an environment of 26°C. The laminate shall be cut into a test piece of 80 mm x 200 mm using a specified mold. A mating material to contact the cut test piece shall also be prepared. In this case, the mating material shall be made of metal, for example, stainless steel. Next, the test piece shall be placed on the mating material so that the wear-resistant varnish layer 21 faces the mating material, and a sliding piece shall be placed on top of it. The weight of the sliding piece shall be 200 g. Then, the test piece and the sliding piece shall be brought into close contact to prevent slippage. Next, the sliding piece is pulled at a speed of 100 mm/min, and the static friction force (N) and kinetic friction force (N) between the test piece and the mating material are measured. The static friction force and kinetic friction force are divided by the normal force of the sliding piece (1.96 N) to calculate the static friction coefficient and kinetic friction coefficient. The kinetic friction coefficient is determined from the average value up to the first 30 mm after the start of the relative shearing motion between the test piece and the mating material, ignoring the peak of the static friction force. The load cell is directly connected to the sliding piece. Three test pieces are prepared, and the static friction coefficient and kinetic friction coefficient are measured for each test piece. The average value of the values from the three test pieces for the static friction coefficient and kinetic friction coefficient is then taken as the static friction coefficient or kinetic friction coefficient of the laminate 10.

<Printing layer>
The first printing layer 15a and the second printing layer 15b are layers on which patterns or designs are printed, and are layers for improving the design of the laminate 10. As the first printing layer 15a and the second printing layer 15b, an ink composition can be used which is prepared by mainly using one or more types of ordinary ink vehicles, and optionally adding one or more types of plasticizers, stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, curing agents, crosslinking agents, lubricants, antistatic agents, fillers, and other additives, and further adding colorants such as dyes and pigments, and thoroughly mixing with a solvent, diluent, etc. Examples of such ink vehicles include linseed oil, tung oil, soybean oil, hydrocarbon oil, rosin, rosin ester, rosin-modified resin, shellac, alkyd resin, phenolic resin, maleic acid resin, natural resin, hydrocarbon resin, polyvinyl chloride resin, polyacetic acid resin, polystyrene resin, polyvinyl butyral resin, acrylic or methacrylic resin, polyamide resin, polyester resin, polyurethane resin, epoxy resin, urea resin, melamine resin, aminoalkyd resin, nitrocellulose, ethylcellulose, chlorinated rubber, cyclic rubber, and others. The printing method may be gravure printing, letterpress printing, screen printing, transfer printing, flexographic printing, or other printing methods.

<Abrasion-resistant resin layer>
The wear-resistant resin layer 22 is a layer that improves the wear resistance of the laminate 10 while also improving its adhesion to the inner sealant layer 12. The wear-resistant resin layer 22 may contain linear low-density polyethylene. This allows for a more effective improvement in adhesion to the inner sealant layer 12 containing linear low-density polyethylene. In addition to linear low-density polyethylene, other materials such as low-density polyethylene may also be used as the material constituting the wear-resistant resin layer 22.

Furthermore, a first printing layer 15a is formed on the abrasion-resistant resin layer 22. Therefore, it is preferable that the abrasion-resistant resin layer 22 be an extruded resin layer. Extruded resin layers have good compatibility with the ink composition. Therefore, having an extruded resin layer 22 makes it easier to form the first printing layer 15a on the abrasion-resistant resin layer 22.

Furthermore, in this embodiment, the thickness of the wear-resistant resin layer 22 is preferably 10 μm or more and 60 μm or less.

<Outer sealant layer>
The outer sealant layer 11 is a layer for bonding the laminates 10 together, and the material constituting the outer sealant layer 11 can be any material that melts and fuses when heated.

In this case, the outer sealant layer 11 can be, for example, a film made of one or more of the following resins: low-density polyethylene (LDPE) film, medium-density polyethylene (MDPE) film, high-density polyethylene (HDPE) film, linear low-density polyethylene (LLDPE) film, polypropylene film, acid-modified polyolefin resin film obtained by modifying polyethylene or polypropylene with acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, or other unsaturated carboxylic acids, polyvinyl acetate resin film, polyester resin film, polystyrene resin film, polyacrylonitrile, saturated polyester, polyvinyl alcohol, or other resins.

Here, low-density polyethylene is polyethylene with a density of 910 kg/ ^m³ to 930 kg/ ^m³ . Medium-density polyethylene is polyethylene with a density of 930 kg/ ^m³ to 942 kg/ ^m³ . High-density polyethylene is polyethylene with a density of 942 kg/ ^m³ or more. Low-density polyethylene can be obtained, for example, by polymerizing ethylene at a high pressure of 1000 atmospheres to less than 2000 atmospheres. Medium-density polyethylene and high-density polyethylene can be obtained, for example, by polymerizing ethylene at a medium or low pressure of 1 atmosphere to less than 1000 atmospheres.

Medium-density polyethylene and high-density polyethylene may partially contain copolymers of ethylene and α-olefins. Furthermore, even when polymerizing ethylene at medium or low pressure, medium-density or low-density polyethylene can be produced if it contains copolymers of ethylene and α-olefins. The linear low-density polyethylene described above is such a polyethylene. Linear low-density polyethylene is obtained by copolymerizing a linear polymer obtained by polymerizing ethylene at medium or low pressure with α-olefins to introduce short-chain branching. Examples of α-olefins include 1-butene ( _C4 ), 1-hexene ( _C6 ), 4-methylpentene ( _C6 ), and 1-octene ( _C8 ). The density of linear low-density polyethylene is, for example, 915 kg/ ^m³ to 945 kg/ ^m³ .

The outer sealant layer 11 may also contain a biomass-derived resin. For example, if the outer sealant layer 11 contains polyethylene or polypropylene, the polyethylene may be biomass polyethylene, and the polypropylene may be biomass polypropylene. By including a biomass-derived resin in the outer sealant layer 11, the amount of fossil fuels used can be reduced, thereby reducing the environmental impact of the laminate 10. Biomass polyethylene is a monomer polymer containing biomass-derived ethylene. Because biomass-derived ethylene is used as the raw material monomer, the resulting polyolefin is biomass-derived. The content of biomass-derived ethylene in the raw material monomer does not need to be 100% by mass; for example, it is preferably 50% or more, more preferably 80% or more. The raw material monomer may contain fossil fuel-derived ethylene, or it may contain α-olefin monomers such as butylene, hexene, and octene.

For example, biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, biomass-derived fermented ethanol obtained from plant materials is preferred. The plant materials are not particularly limited, and conventionally known plants can be used. Examples of conventionally known plants include corn, sugarcane, beets, and manioc.

In this embodiment, the heat-sealable film can be prepared by, for example, using one or more of the above-mentioned resins as the main components, and optionally adding desired additives to prepare a resin composition. Then, using the resin composition prepared above, a film or sheet can be formed using, for example, a T-die method, an inflation method, or other molding methods.

Furthermore, the outer sealant layer 11 may be made by adding, for example, an antiblocking agent, a lubricant (such as a fatty acid amide), a flame retardant, or an inorganic or organic filler.

Furthermore, in this embodiment, the thickness of the outer sealant layer 11 is preferably 50 μm or more and 250 μm or less.

<Base layer and intermediate layer>
The base layer 13 and the intermediate layer 17 (hereinafter also simply referred to as the base layer 13, etc.) are layers that support, for example, the outer sealant layer 11 and the inner sealant layer 12, and increase the overall strength of the laminate 10. As materials constituting the base layer 13, etc., for example, polyester resins, polyamide resins, polyaramid resins, polyolefin resins, polycarbonate resins, polyacetal resins, fluororesins, and other tough resin films or sheets can be used. As polyolefin resins, for example, films of extruded low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene can be used.

Furthermore, the resin film or sheet described above can be an unstretched film or a stretched film stretched uniaxially or biaxially. Among these, in this embodiment, a biaxially oriented polyester resin film is preferred because it offers superior printability.

In this embodiment, the thickness of the base layer 13, etc., is preferably 10 μm or more and 25 μm or less.

<Inner sealant layer>
The inner sealant layer 12 is a layer for bonding the laminates 10 together, and the material constituting the inner sealant layer 12 can be any material that melts and fuses when heated.

As shown in Figure 2, the inner sealant layer 12 has multiple layers. In the example shown in Figure 2, as described above, the inner sealant layer 12 has a first inner layer 12a, a second inner layer 12b, and a third inner layer 12c.

In the inner sealant layer 12, the materials constituting the first inner layer 12a, the second inner layer 12b, and the third inner layer 12c can be the same materials as those used for the outer sealant layer 11. For example, the inner sealant layer 12 (first inner layer 12a, second inner layer 12b, and third inner layer 12c) may contain biomass-derived resin. In this case, for example, if the inner sealant layer 12 contains polyethylene or polypropylene, the polyethylene may be biomass polyethylene, and the polypropylene may be biomass polypropylene.

When the inner sealant layer 12 contains biomass-derived resin, it is possible to reduce the environmental impact of the tube container 40 while suppressing cosmetic defects. Specifically, the surface of the layer containing biomass-derived resin may develop a fish-eye-like appearance defect, known as a "fish eye," compared to the surface of a layer without biomass-derived resin. This fish eye defect can occur, for example, when a portion of the resin does not completely melt and remains as a lump. In contrast, the inner sealant layer 12 of the tube container 40 is not visible from the outside. Therefore, even if a fish eye defect occurs on the surface of the inner sealant layer 12, it does not adversely affect the appearance of the tube container 40. As a result, when the inner sealant layer 12 contains biomass-derived resin, it is possible to reduce the environmental impact of the tube container 40 while suppressing cosmetic defects.

In this embodiment, the density of the material constituting the second inner layer 12b may differ from the density of the material constituting the first inner layer 12a and the density of the material constituting the third inner layer 12c. For example, the density of the material constituting the second inner layer 12b may be higher than the density of the material constituting the first inner layer 12a and the density of the material constituting the third inner layer 12c. In this case, by increasing the density of the material constituting the second inner layer 12b, the overall density of the inner sealant layer 12 can be increased while maintaining the meltable properties of the third inner layer 12c. This increases the overall rigidity of the laminate 10. Alternatively, the density of the material constituting the second inner layer 12b may be lower than the density of the material constituting the first inner layer 12a and the density of the material constituting the third inner layer 12c. In this case, for example, if the second inner layer 12b contains a biomass-derived resin, the biomass-derived resin can be sandwiched between the high-density first inner layer 12a and the third inner layer 12c. This suppresses the elution of the biomass-derived resin.

The density of the inner sealant layer 12 may be between 0.92 g/ ^m³ and 0.93 g/ ^m³ . A density of 0.92 g/ ^m³ or higher for the inner sealant layer 12 increases the adhesive strength between the outer sealant layer 11 and the inner sealant layer 12 when forming the body seal portion 44. This prevents the outer sealant layer 11 and the inner sealant layer 12 from peeling off at the body seal portion 44. Furthermore, a density of 0.93 g/ ^m³ or lower for the inner sealant layer 12 improves the productivity of the tube container 40. Specifically, a higher density of the inner sealant layer 12 tends to increase the melting point of the inner sealant layer 12. Therefore, a higher density of the inner sealant layer 12 may result in a higher sealing temperature when forming the body seal portion 44. In contrast, by having an inner sealant layer 12 with a density of 0.93 g/ ^m³ or less, it is possible to suppress the temperature from rising when forming the body seal portion 44. This improves the productivity of the tube container 40.

As described above, the inner sealant layer 12 constitutes the inner surface 102 of the laminate 10. In this embodiment, the static friction coefficient of the inner surface 102 against the metal is 0.40 or less. This prevents scratches from occurring on the inner sealant layer 12 even if the transport of the laminate 10 stops during the manufacturing of the body tube 41.

Furthermore, the coefficient of dynamic friction of the inner surface 102 against the metal is 0.35 or less. This prevents scratches from occurring on the inner sealant layer 12 when the laminate 10 is wrapped around the inner sealing member 80 (described later). Also, because scratches on the inner sealant layer 12 are suppressed, the bonding between the inner sealant layer 12 and the outer sealant layer 11 (wear-resistant resin layer 22) can be improved. Moreover, because scratches on the inner sealant layer 12 are suppressed, foreign matter (e.g., precipitated pigment, etc.) resulting from scratches on the inner sealant layer 12 can be prevented from adhering to the inner sealing member 80 (described later).

Furthermore, the static and dynamic friction coefficients of the inner surface 102 against the metal may be adjusted by selecting the resin material used for the inner sealant layer 12, as described later, or by applying varnish or the like to the inner sealant layer 12. The static and dynamic friction coefficients of the inner surface 102 against the metal can be measured by the static and dynamic friction coefficient measurement tests described above. During measurement, the test piece is placed on the mating material with the inner sealant layer 12 facing the mating material, and the sliding piece is placed on top of it.

In this embodiment, the thickness of the inner sealant layer 12 is preferably 50 μm or more and 250 μm or less.

<Adhesive layer>
The adhesive layers, such as the first adhesive layer 14a, the second adhesive layer 14b, and the third adhesive layer 14c, are layers for bonding the outer sealant layer 11, the base material layer 13, the inner sealant layer 12, etc. to each other. The material used for these adhesive layers can be appropriately selected depending on the resin that makes up the layers to be bonded.

As the adhesive layer, for example, anchor coating agents such as isocyanate-based (urethane-based), polyethyleneimine-based, polybutadiene-based, and organotitanium-based materials, or polyurethane-based, polyacrylic-based, polyester-based, epoxy-based, polyvinyl acetate-based, cellulose-based, and other laminating adhesives can be used as desired.

Furthermore, suitable adhesive layers include, for example, polyethylene, polypropylene, linear low-density polyethylene, ethylene-vinyl alcohol, ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid copolymer, ionomer, maleic anhydride-modified polyolefin resin, and the like.

In this embodiment, the thickness of the adhesive layer is preferably 3 μm or more and 60 μm or less.

Furthermore, the outer sealant layer 11, the base layer 13, the inner sealant layer 12, etc., can be laminated together using methods such as wet lamination, dry lamination, solvent-free dry lamination, extrusion lamination, T-die co-extrusion molding, co-extrusion lamination, inflation lamination, or any other method. Additionally, if necessary, pre-treatments such as corona treatment or ozone treatment can be applied to the film during the lamination process described above.

<Barrier layer>
The barrier layer 16 is a layer for suppressing the permeation of oxygen gas and water vapor. For example, the barrier layer 16 can be made of a gas barrier material against oxygen gas and water vapor, a light-shielding material against sunlight, or a material that has fragrance-retaining properties for the contents.

As the barrier layer 16, for example, aluminum foil, tin, lead, copper, iron, nickel, or alloys thereof, or a thin metal vapor-deposited layer such as aluminum can be used. When using aluminum foil as the barrier layer 16, the thickness of the barrier layer 16 may be approximately 5 μm to 20 μm. By using aluminum foil as the barrier layer 16, the laminate 10 can be easily fabricated.

Furthermore, when using a metal vapor-deposited layer such as aluminum as the barrier layer 16, a thin film of metal such as aluminum can be formed on the intermediate layer 17 using physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, ion plating, or cluster ion beam deposition.

When an aluminum metal vapor-deposited layer is used as the barrier layer 16, the thickness of the barrier layer 16 is usually preferably between 50 Å and 3000 Å, and particularly preferably between 100 Å and 2000 Å. Furthermore, the surface of the intermediate layer 17 supporting the above-mentioned aluminum vapor-deposited thin film may be pre-coated with, for example, a vapor deposition primer, to improve the adhesion of the vapor-deposited film, and other necessary pre-treatments may be applied as desired.

Furthermore, the barrier layer 16 may be a transparent vapor-deposited layer that can be formed by conventionally known methods. The barrier layer 16 being a transparent vapor-deposited layer makes the laminate 10 transparent. In this case, the barrier layer 16 may be a transparent vapor-deposited layer made of an inorganic oxide vapor-deposited layer.

As the transparent vapor-deposited layer, for example, oxide layers of silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), and yttrium (Y) can be used. In particular, for tube containers, a vapor-deposited layer of aluminum oxide or silicon oxide is preferred.

Inorganic oxides are expressed as MO _X , such as SiO _X , AlO _X, etc. (where M represents an inorganic element, and the value of X varies depending on the inorganic element). The range of X values is as follows: silicon (Si) 0 to 2, aluminum (Al) 0 to 1.5, magnesium (Mg) 0 to 1, calcium (Ca) 0 to 1, potassium (K) 0 to 0.5, tin (Sn) 0 to 2, sodium (Na) 0 to 0.5, boron (B) 0 to 1.5, titanium (Ti) 0 to 2, lead (Pb) 0 to 2, zirconium (Zr) 0 to 2, and yttrium (Y) 0 to 1.5. In the above, when X = 0, it is a complete inorganic element (pure substance), which is not transparent, and the upper limit of the range of X is the value when it is completely oxidized. For packaging materials, silicon (Si) and aluminum (Al) are preferably used, with silicon (Si) having a value in the range of 1.0 to 2.0 and aluminum (Al) having a value in the range of 0.5 to 1.5.

The thickness of the transparent vapor-deposited layer varies depending on the type of inorganic oxide used, but it is desirable to arbitrarily select and form it within the range of 50 Å to 2000 Å, preferably 100 Å to 1000 Å. For example, in the case of an aluminum oxide or silicon oxide vapor-deposited layer, a thickness of 50 Å to 500 Å, and more preferably 100 Å to 300 Å, is desirable.

The transparent vapor-deposited layer can be formed on the intermediate layer 17 using the following formation method. Examples of formation methods for the vapor-deposited layer include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, or chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermochemical vapor deposition, and photochemical vapor deposition. Specifically, the vapor-deposited layer can be formed on a molding roller using a roller-type vapor deposition layer formation apparatus.

<Other layers>
Other layers may be provided, for example, an opacity layer. The opacity layer is a layer that prevents color changes or variations in each layer from affecting the color of the pattern on the first printed layer 15a. Olefin resin can be used for the opacity layer. More specifically, it is preferable to use a polyethylene film such as low-density polyethylene, linear low-density polyethylene, or medium-density polyethylene as the opacity layer. These polyethylene films may be colored, for example, an opaque polyethylene film. The thickness of the opacity layer is preferably, for example, 50 μm to 200 μm.

In the tube container 40 according to this embodiment, the joining of the body tube 41 and the head member 43 can be performed by heat welding when the head member 43 is formed by compression molding, as described later. However, it is not limited to this, and the joining of the body tube 41 and the head member 43 may also be performed by injection molding.

(Method of manufacturing a tube container with a cap)
Next, a method for manufacturing the capped tube container 40A will be described with reference to Figures 3 to 6.

First, prepare the laminate 10 shown in Figure 2.

Next, a tube container 40 is manufactured from the resulting laminate 10.

First, the laminate 10 is rolled up, and the opposing edges are joined together, for example, by heat sealing, to form a cylindrical tube and create the body tube 41. At this time, as shown in Figures 3(a)-(b), the laminate 10 is first wrapped around the outer surface of the cylindrical inner sealing member 80, overlapping the opposing edges of the laminate 10. At this time, the laminate 10 is wrapped around the inner sealing member 80 so that the inner sealant layer 12 of the laminate 10 faces the outer surface of the inner sealing member 80. The inner sealing member 80 can be made of metal, for example, stainless steel. Furthermore, when overlapping the opposing edges of the laminate 10, the laminate 10 is conveyed downstream (to the left in Figures 3(a)-(b)) by a conveyor belt and guide rolls (not shown).

Next, as shown in Figure 3(b), the outer sealing member 81 is pressed against the overlapping portion of the opposing edges of the laminate 10, sandwiching the overlapping portion between the inner sealing member 80 and the outer sealing member 81. Then, the overlapping portion of the opposing edges of the laminate 10 is joined by heat sealing. In this case, the outer sealant layer 11 (see Figure 2, etc.) provided on the outer surface 101 side of the laminate 10 and the inner sealant layer 12 (see Figure 2, etc.) provided on the inner surface 102 side melt and join together, forming the body seal portion 44.

Subsequently, the joined laminate 10 is cut into individual body tubes 41. In this way, the body tubes 41 are manufactured as shown in Figure 4. The manufacturing speed of the body tubes 41 can be as low as approximately 300 tubes/min.

Next, the tube container 40 described above is manufactured by compression molding.

In this process, as shown in Figure 5(a), the cylindrical laminate 10 (body tube 41) is wrapped around the mandrel 72, and a mold 71 for compression molding the head member 43 is attached to one end of the mandrel 72. That is, the pre-formed cylindrical laminate 10 (body tube 41) is inserted into the mandrel 72, whose tip serves as the core for compression molding the head member 43, and then advanced to a predetermined position within the cavity of the mold 71 for molding the head member 43.

Next, the head member 43 is compression molded by supplying molten resin from a resin supply device (not shown) into the mold 71. In this case, by inserting one end 42 of the body tube 41 into the mold 71, the head member 43 is molded, and at the same time, the body tube 41 is integrally fused to the head member 43. Afterward, by removing the integrated head member 43 and body tube 41 from the mold 71 and mandrel 72, a tube container 40 is obtained, comprising the body tube 41 and the head member 43 joined to one end 42 of the body tube 41 (see Figure 5(b)).

Furthermore, when manufacturing the capped tube container 40A, the cap 49 is prepared in parallel with the manufacturing of the tube container 40. In this case, the cap 49 is manufactured by injection molding using, for example, an injection molding machine (not shown). Then, by screwing the cap 49 onto the opening of the head member 43 of the tube container 40, the capped tube container 40A is obtained, as shown in Figure 6.

Subsequently, an appropriate amount of the contents C is filled through the opening 41B (see Figures 4 and 6) of the body tube 41. Then, the bottom seal portion 45 (see Figure 1) is formed by welding the opening 41B. In this way, a capped tube container 40A filled and packaged with contents C is obtained.

As described above, according to this embodiment, the laminate 10 comprises a wear-resistant varnish layer 21 arranged sequentially from the outer surface 101 to the inner surface 102, a first printed layer 15a, a wear-resistant resin layer 22, an outer sealant layer 11, and an inner sealant layer 12. The inner sealant layer 12 has a first inner layer 12a, a second inner layer 12b, and a third inner layer 12c, arranged sequentially from the outer surface 101 to the inner surface 102. Furthermore, the density of the material constituting the second inner layer 12b differs from the density of the material constituting the first inner layer 12a and the material constituting the third inner layer 12c. This allows for an increase in the overall density of the inner sealant layer 12 while maintaining the meltable properties of the third inner layer 12c. Therefore, the overall rigidity of the laminate 10 can be increased. As a result, the desired performance can be maintained even when the thickness of the inner sealant layer 12 is reduced. Therefore, the amount of resin used in the tube container 40 can be reduced.

Furthermore, the density of the inner sealant layer 12 is 0.92 g/ ^m³ or more and 0.93 g/ ^m³ or less. This prevents the outer sealant layer 11 and the inner sealant layer 12 from peeling off at the body seal portion 44. In addition, since the sealing temperature is suppressed when forming the body seal portion 44, the productivity of the tube container 40 can be improved. For this reason, even if the thickness of the inner sealant layer 12 is reduced, the desired performance can be maintained and the amount of resin used in the tube container 40 can be reduced. The fact that such effects can be obtained will be explained in the examples described later.

Furthermore, the static friction coefficient of the outer surface 101 against metal is 0.25 or less, and the dynamic friction coefficient of the outer surface 101 against metal is 0.20 or less. This prevents scratches on the outer surface of the body tubes 41 even when they rub against each other during filling with contents or when multiple tube containers 40 are packed in cardboard boxes for shipping and storage.

Furthermore, the static friction coefficient of the inner surface 102 against the metal is 0.40 or less, and the dynamic friction coefficient of the inner surface 102 against the metal is 0.35 or less. This suppresses the occurrence of scratches on the inner sealant layer 12. Also, because the occurrence of scratches on the inner sealant layer 12 is suppressed, the bonding between the inner sealant layer 12 and the outer sealant layer 11 (wear-resistant resin layer 22) can be improved. Therefore, even if the thickness of the inner sealant layer 12 is reduced, the desired performance can be maintained, and the amount of resin used in the tube container 40 can be reduced. Furthermore, because the occurrence of scratches on the inner sealant layer 12 is suppressed, it is possible to prevent foreign matter (e.g., precipitated pigment, etc.) caused by scratches on the inner sealant layer 12 from adhering to the inner sealing member 80, etc., as described later.

Next, specific examples of the above embodiment will be described.

(Example 1)
A laminate 10, as shown in Figure 2, was fabricated. First, a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: EB522, thickness 12 μm) was prepared as the base layer 13. Subsequently, a second printed layer 15b was formed on the polyethylene terephthalate film.

Furthermore, as the intermediate layer 17, a polyethylene terephthalate film (manufactured by Oike Kogyo Co., Ltd., product name: Tetrite EXC-B, thickness 12 μm) with an aluminum vapor-deposited layer (barrier layer 16) was prepared.

Furthermore, a polyethylene film (manufactured by DNP Technopack Co., Ltd., product name: BCO LZ27N, average density: 0.927 g/ ^cm³ , thickness 150 μm) was prepared as the inner sealant layer 12. Both of these polyethylene films were three-layer films.

When producing the polyethylene film, first, a resin was prepared by melting 100 parts by mass of linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: UZ3520L, density: 0.931 g/ ^cm³ , MFR: 2.1 g/10 min, biomass content: 0%) as the resin constituting the first inner layer 12a.

Furthermore, as resins constituting the second inner layer 12b, 42 parts by mass of linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolu SP4020, density: 0.937 g/ ^cm³ , MFR: 2.1 g/10 min, biomass content: 0%) and 58 parts by mass of linear low-density polyethylene derived from biomass (manufactured by Braschem, product name: SLL-118, density: 0.916 g/ ^cm³ , MFR: 1.0 g/10 min, biomass content: 87%) were prepared. The average density of the resins constituting the second inner layer 12b was 0.925 g/ ^cm³ .

Furthermore, as the resin constituting the third inner layer 12c, a resin was prepared by separately melting 100 parts by mass of linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: UZ3520L, density: 0.931 g/ ^cm³ , MFR: 2.1 g/10 min, biomass content: 0%).

Next, these molten materials were co-extruded by inflation molding to produce a polyethylene film with a thickness ratio of 1:3:1 (first inner layer 12a: second inner layer 12b: third inner layer 12c). The thickness of the resin film was 150 μm. The average density of the polyethylene film was 0.927 g/ ^cm³ . The biomass content of the polyethylene film was 25%.

Next, the films for the base layer 13, the intermediate layer 17, and the inner sealant layer 12 were bonded together by a dry lamination method to produce an intermediate for the laminate 10. The layer structure of the obtained intermediate is as follows.
PET/Mark/DL/ALM/PET/DL/PEF(PE/PE/PE)
In the above, "PET" means polyethylene terephthalate film (the same applies below). Also, "印" means the printed layer (the same applies below). Also, "DL" means the adhesive layer using a two-component curing adhesive via the dry lamination method (the same applies below). Also, "ALM" means the aluminum vapor-deposited layer (the same applies below). Also, "PEF" means polyethylene film (the same applies below). Furthermore, "PE" means polyethylene (the same applies below).

Next, a polyethylene film (manufactured by DNP Technopack Co., Ltd., product name: SR-WN2, thickness 160 μm) was prepared as the outer sealant layer 11.

Next, low-density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., product name: LC600A) was extruded onto a polyethylene terephthalate film, which served as the intermediate base layer 13, to form an extruded polyethylene layer (first adhesive layer 14a) with a thickness of 25 μm. At this time, a polyethylene film, serving as the outer sealant layer 11, was laminated via the extruded polyethylene layer (first adhesive layer 14a). Furthermore, low-density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., product name: LC600A) was extruded onto the polyethylene film serving as the outer sealant layer 11 to form an abrasion-resistant resin layer 22 with a thickness of 25 μm.

Subsequently, a first printed layer 15a was formed on the abrasion-resistant resin layer 22 using lightfast ink (manufactured by Toyo Ink Co., Ltd., product name: FDFL MP). Furthermore, an abrasion-resistant varnish layer 21 was formed on the first printed layer 15a using varnish (manufactured by Toyo Ink Co., Ltd., product name: FDFL AQF4). In this way, the laminate 10 was fabricated. The layer structure of the obtained laminate 10 is as follows.
Varnish/Seal/PE/PEF/PE/PET/Seal/DL/ALM/PET/DL/PEF(PE/PE/PE)

Furthermore, the tube container 40 shown in Figure 1 was fabricated using the obtained laminate 10. In this case, first, the laminate 10 was formed into a cylindrical shape to create the body tube 41. At this time, the laminate 10 was joined using high-frequency and heat sealing with an inner sealing member 80 and an outer sealing member 81, and then each individual body tube 41 was cut. The fabrication speed of the body tubes 41 was set to 300 pieces/min, and 250 pieces were produced for each sample, for a total of 750 body tubes 41.

Subsequently, these body tubes 41 were each wound around a mandrel 82, and the head members 43 were integrally molded to the body tubes 41 by compression molding to obtain the tube container 40. High-density polyethylene (HDPE) was used as the material for the head members 43.

In this way, a total of 750 tube containers 40 were manufactured.

(Example 2)
A laminate and a tube container were prepared in the same manner as in Example 1, except that a polyethylene film (manufactured by DNP Technopack Co., Ltd., product name: SR-WN2, thickness 130 μm) was used as the outer sealant layer 11.

(Example 3)
Laminates and tube containers were prepared in the same manner as in Example 1, except that linear low-density polyethylene (manufactured by Prime Polymer Co., Ltd., product name: SP1070C) was used as the abrasion-resistant resin layer 22.

(Example 4)
A laminate and a tube container were prepared in the same manner as in Example 3, except that a polyethylene film (manufactured by DNP Technopack Co., Ltd., product name: SR-WN2, thickness 130 μm) was used as the outer sealant layer 11.

(Example 5)
Laminates and tube containers were prepared in the same manner as in Example 1, except that linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolue SP2020, density: 0.916 g/ ^cm³ , MFR: 2.3 g/10 min, biomass content: 0%) was used as the resin constituting the first inner layer 12a and the third inner layer 12c, and linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolue SP2520, density: 0.925 g/ ^cm³ , MFR: 1.9 g/10 min, biomass content: 0%) was used as the resin constituting the second inner layer 12b. The average density of the polyethylene film was 0.922 g/ ^cm³ . The biomass content of the polyethylene film was 0%.

(Example 6)
Laminates and tube containers were prepared in the same manner as in Example 2, except that linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolu SP2020, density: 0.916 g/ ^cm³ , MFR: 2.3 g/10 min, biomass content: 0%) was used as the resin constituting the first inner layer 12a and the third inner layer 12c, and linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolu SP2520, density: 0.925 g/ ^cm³ , MFR: 1.9 g/10 min, biomass content: 0%) was used as the resin constituting the second inner layer 12b. The average density of the polyethylene film was 0.922 g/ ^cm³ . The biomass content of the polyethylene film was 0%.

(Example 7)
Laminates and tube containers were manufactured in the same manner as in Example 1, except that linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolue SP4020, density: 0.937 g/ ^cm³ , MFR: 1.8 g/10 min, biomass content: 0%) was used as the resin constituting the first inner layer 12a; linear low-density polyethylene derived from biomass (manufactured by Braschem, product name: SLL-118, density: 0.916 g/ ^cm³ , MFR: 1.0 g/10 min, biomass content: 87%) was used as the resin constituting the second inner layer 12b; and linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolue SP2320, density: 0.920 g/ ^cm³ , MFR: 1.9 g/10 min, biomass content: 0%) was used as the resin constituting the third inner layer 12c. The average density of the polyethylene film was 0.921 g/ ^cm³ . The biomass content of the polyethylene film was 50%.

(Example 8)
Laminates and tube containers were manufactured in the same manner as in Example 2, except that linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolue SP4020, density: 0.937 g/ ^cm³ , MFR: 1.8 g/10 min, biomass content: 0%) was used as the resin constituting the first inner layer 12a; linear low-density polyethylene derived from biomass (manufactured by Braschem, product name: SLL-118, density: 0.916 g/ ^cm³ , MFR: 1.0 g/10 min, biomass content: 87%) was used as the resin constituting the second inner layer 12b; and linear low-density polyethylene derived from fossil fuels (manufactured by Prime Polymer Co., Ltd., product name: Evolue SP2320, density: 0.920 g/ ^cm³ , MFR: 1.9 g/10 min, biomass content: 0%) was used as the resin constituting the third inner layer 12c. The average density of the polyethylene film was 0.921 g/ ^cm³ . The biomass content of the polyethylene film was 50%.

(Comparative Example 1)
A laminate 100, as shown in Figure 7, was fabricated. This laminate comprises an outer sealant layer 110 arranged sequentially from the outer surface 111 to the inner surface 112, a first adhesive layer 140a, a base material layer 130, a printing layer 150, a second adhesive layer 140b, a barrier layer 160, an intermediate layer 170, a third adhesive layer 140c, and an inner sealant layer 120. Although not shown in the figures, the outer sealant layer 110 and the inner sealant layer 120 each had multiple layers (3 layers).

The outer sealant layer 110, first adhesive layer 140a, base material layer 130, printing layer 150, second adhesive layer 140b, barrier layer 160, intermediate layer 170, third adhesive layer 140c, and inner sealant layer 120 of the laminate 100 correspond to the outer sealant layer 11, first adhesive layer 14a, base material layer 13, second printing layer 15b, second adhesive layer 14b, barrier layer 16, intermediate layer 17, third adhesive layer 14c, and inner sealant layer 12 of the laminate 10, respectively.

When preparing the laminate 100 according to Comparative Example 1, first, a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: EB522, thickness 12 μm) was prepared as the base layer 130. Next, a printed layer 150 was formed on the polyethylene terephthalate film.

Furthermore, a polyethylene terephthalate film (manufactured by Oike Kogyo Co., Ltd., product name: Tetrilite EXC-B, thickness 12 μm) with an aluminum vapor-deposited layer (barrier layer 160) was prepared as the intermediate layer 170.

Furthermore, an antistatic polyethylene film (manufactured by DNP Technopack Co., Ltd., product name: BCO LZ27N AS, average density: 0.927 g/ ^cm³ , thickness 110 μm) was prepared as the outer sealant layer 11. In addition, a polyethylene film (manufactured by DNP Technopack Co., Ltd., average density: 0.918 g/ ^cm³ , thickness 180 μm) was prepared as the inner sealant layer 12. Both of these polyethylene films were three-layer films. Of these, the polyethylene film used as the inner sealant layer 12 had a density of 0.916 g/ ^cm³ for the second inner layer, and densities of 0.920 g/ ^cm³ for the first and third inner layers, respectively. As mentioned above, in Figure 7, the illustration of each layer (3 layers) of the outer sealant layer 110 and each layer (3 layers) of the inner sealant layer 120 is omitted.

Next, the films for the outer sealant layer 11, the base layer 13, the intermediate layer 17, and the inner sealant layer 12 were bonded together by a dry lamination method to produce a laminate 10. The biomass content of the bonded layer by the dry lamination method was 10%. The layer structure of the obtained laminate 10 is as follows.
ASPEF(PE/PE/PE)/DL/PET/Mark/DL/ALM/PET/DL/PEF(PE/PE/PE)
In the above, "ASPEF" refers to polyethylene film containing an antistatic agent (the same applies hereafter).

Furthermore, a tube container was fabricated using the obtained laminate 100 in the same manner as in Example 1.

(Comparative Example 2)
A laminate and a tube container were prepared in the same manner as in Comparative Example 1, except that a polyethylene film (manufactured by DNP Technopack Co., Ltd., product name: SR-WN2, thickness 180 μm) was used as the inner sealant layer 12.

<Static friction coefficient measurement test / Dynamic friction coefficient measurement test>
The static and dynamic friction coefficients of the inner and outer surfaces of the laminates from Examples 1 to Comparative Example 2 were measured, respectively. The static and dynamic friction coefficients were measured in accordance with JIS K 7125:1999, 8.2 "Measurement of films when in contact with metals or other materials". First, the measuring device and the laminate 10 were stabilized in an environment of 26°C from each laminate. The laminate was then cut into 80 mm x 200 mm test pieces using a specified mold. A mating material was prepared to contact the cut test piece. The mating material was made of SUS304. Next, the test piece was placed on the mating material with the outer sealant layer side (i.e., the outer surface) facing the mating material, and a sliding piece was placed on top of it. In another test piece, the test piece was placed on the mating material with the inner sealant layer side (i.e., the inner surface) facing the mating material, and a sliding piece was placed on top of it. The total weight of the sliding pieces was 200 g. The test specimen and the sliding piece were then brought into close contact to prevent slippage, and the sliding piece was pulled at a speed of 100 mm/min. The static friction force (N) and kinetic friction force (N) between the test specimen and the mating material were measured, and the static and kinetic friction forces were divided by the normal force of the sliding piece (1.96 N) to calculate the static and kinetic friction coefficients. The kinetic friction coefficient was determined from the average value up to the first 30 mm after the start of the relative shearing motion between the test specimen and the mating material, neglecting the peak of the static friction force. The load cell was directly connected to the sliding piece. Three test specimens were prepared, and the static and kinetic friction coefficients were measured for each specimen. The average value of the values from the three test specimens was then used as the static or kinetic friction coefficient of the laminate.

<Rubbing Examination (JSPS Examination)>
A rubbing test was conducted on the laminates according to Example 1 to Comparative Example 2, simulating transport conditions. The measuring device used was the FR-2 from Suga Test Instruments Co., Ltd., and the measurement was performed in accordance with JIS-L-0849. First, a strip-shaped (30 mm wide) laminate was fixed to the lower test piece holder, and a strip-shaped (30 mm wide) laminate of the same material was attached to the upper friction element. The weight of the weight was 200 g. The rubbing test was repeated 100 times, and the number of scratches that occurred on the surface of the laminate was counted visually. If the number of scratches on the surface of the laminate was less than 10, the test result was A (good). If the number of scratches on the surface of the laminate was 10 or more but less than 20, the test result was B (acceptable). If the number of scratches on the surface of the laminate was 20 or more, the test result was C (poor).

<Evaluation of joint strength in the body seal area>
The bonding performance at the body seal portion was evaluated for the laminates according to Example 1 to Comparative Example 2. For each laminate, the meltability at the body seal portion was confirmed using an optical microscope manufactured by Keyence Corporation. If the interface between the laminates was not visible at the body seal portion and complete melting was achieved, the test result was rated as A (Good). If the interface between the laminates was slightly visible at the body seal portion, the test result was rated as B (Acceptable).

<Evaluation of the joint between the body tube and the head component>
Furthermore, as shown in Figure 8(a), the test piece S1 was made by cutting out the portion of the body tube 41 including the body seal portion 44, along with the head member 43, into a rectangular shape with a width of 15 mm and a length of 100 mm. When cutting out the body tube 41, the body tube 41 and head member 43 were cut out so that the longitudinal direction of the test piece S1 was the vertical direction of the body tube 41, and the body seal portion 44 was located approximately in the center of the longitudinal direction of the test piece S1. Three test pieces S1 were prepared in this way.

Furthermore, as test specimen S2, three rectangular pieces were prepared, each 15 mm wide and 100 mm long, cut from the portion of the tube container 40 that was 180° rotationally symmetrical with respect to the central axis of the portion from which test specimen S1 was cut, including the head member 43. When cutting the body tube 41, the body tube 41 and head member 43 were cut so that the longitudinal direction of test specimen S2 was aligned with the vertical direction of the body tube 41. In this way, three test specimens S2 were prepared.

Next, the adhesive strength between the body tube 41 and the head member 43 was measured for these test specimens S1 and S2 using a tensile testing machine (STA-1150, manufactured by Orientec Co., Ltd.).

During the measurement, first, as shown in Figure 8(b), the body tube 41 and head member 43 of test specimens S1 and S2 were partially separated. Next, as shown in Figure 8(c), the separated body tube 41 and head member 43 were gripped by the grips 80 of the tensile testing machine, and test specimens S1 and S2 were pulled by moving the grips 80 in opposite directions. The tensile speed for pulling test specimens S1 and S2 was set to 300 mm/min. The maximum load was defined as the joint strength (N) between the body tube and the head member.

<Exterior Evaluation>
The tube containers according to Example 1 to Comparative Example 2 were evaluated for their appearance. Each tube container was filled with its contents, and a bottom seal was formed by ultrasonic sealing. After the bottom seal was formed, the occurrence of peeling and tearing of the surface was checked. If no peeling or tearing occurred, the test result was rated A (Good). If peeling or tearing occurred but did not affect the quality, the test result was rated B (Acceptable). If peeling or tearing occurred and there was a quality problem, the test result was rated C (Unacceptable).

The results are shown in Figures 9 to 12. Figure 9 is a table showing the density and inner sealant layer thickness for Examples 1 to Comparative Example 2. Figure 10 is a table showing the results of the static friction coefficient measurement test, dynamic friction coefficient measurement test, and rubbing test. Figure 11 is a table showing the results of the joint performance evaluation at the body seal portion and the joint performance evaluation between the body tube and the head member. Figure 12 is a table showing the biomass content of the inner sealant layer for Examples 1 to Comparative Example 2.

As a result, as shown in Figures 9 to 12, the tube containers according to Examples 1 to 8 maintained the desired performance even when the thickness of the inner sealant layer was reduced compared to the tube containers according to Comparative Examples 1 and 2. Therefore, it was found that the amount of resin used in the tube container 40 can be reduced according to this embodiment.

The multiple components disclosed in the above embodiment can be combined as needed. Alternatively, some components may be removed from all the components shown in the above embodiment.

10 Laminate 11 Outer sealant layer 12 Inner sealant layer 12a First inner layer 12b Second inner layer 12c Third inner layer 13 Base material layer 15a Printed layer 16 Barrier layer 21 Abrasion-resistant varnish layer 22 Abrasion-resistant resin layer 40 Tube container 40A Tube container with cap 41 Body tube 42 One end 43 Head member 49 Cap 101 Outer surface 102 Inner surface

Claims (8)

It comprises a wear-resistant varnish layer, a printed layer, a wear-resistant resin layer, an outer sealant layer, and an inner sealant layer, arranged sequentially from the outer surface to the inner surface.
The entire outer surface is composed of the abrasion-resistant varnish layer.
The inner sealant layer comprises a first inner layer, a second inner layer, and a third inner layer, arranged sequentially from the outer surface toward the inner surface.
The density of the material constituting the second inner layer is different from the density of the material constituting the first inner layer and the density of the material constituting the third inner layer.
The density of the inner sealant layer is 0.92 g/ ^cm³ or more and 0.93 g/ ^cm³ or less.
The density of the material constituting the first inner layer is 0.916 g/ ^cm³ or more and 0.937 g/ ^cm³ or less.
The density of the material constituting the second inner layer is 0.916 g/ ^cm³ or more and 0.925 g/ ^cm³ or less.
The density of the material constituting the third inner layer is 0.916 g/ ^cm³ or more and 0.931 g/ ^cm³ or less.
The static friction coefficient of the outer surface against SUS304 is 0.25 or less.
The coefficient of dynamic friction of the outer surface against SUS304 is 0.20 or less.
The static friction coefficient of the inner surface relative to SUS304 is 0.40 or less.
A laminate in which the coefficient of dynamic friction of the inner surface relative to SUS304 is 0.35 or less. The laminate according to claim 1, wherein the inner sealant layer contains a biomass-derived resin. The laminate according to claim 1, further comprising a substrate layer provided between the outer sealant layer and the inner sealant layer. The laminate according to claim 3, further comprising a barrier layer provided between the substrate layer and the inner sealant layer. The laminate according to claim 1, wherein the wear-resistant varnish layer contains an ultraviolet-curable resin. The laminate according to claim 1, wherein the wear-resistant resin layer contains linear low-density polyethylene. In a tube container,
A body tube formed by overlapping and joining opposing edges of a laminate according to any one of claims 1 to 6,
It comprises a head member joined to one end of the body tube ,
A tube container in which the abrasion-resistant varnish layer and the inner sealant layer are joined to each other at a joint formed by overlapping and joining the edges of the aforementioned edges . In a tube container with a cap,
The tube container according to claim 7,
A capped tube container comprising a cap attached to the head member.