Extrusion blown containers

Abstract

To obtain an extrusion blow container with an original appearance while suppressing a cost increase.SOLUTION: An extrusion blow container 1 has a container body in which a mouth part, a truck part 13, and a bottom part are continuously provided in this order from an upper side toward a lower side along a container axial direction. The container body includes: an outer layer made of synthetic resin having light permeability; and an inner layer 23 made of synthetic resin provided on an inner surface side of the container body rather than the outer layer, and containing a plurality of fine metal pieces 25a and 25b formed in a slender columnar shape or plate like shape, and having light permeability. The fine metal piece includes, from upper to lower sides, inclined pieces 25a extending toward the outer side in a radial direction, and straight pieces 25b extending along a container axis. In the inner layer, at least in an outer part located on the outer side in a radial direction from a central part in the radial direction, the number of inclined pieces is larger than the number of straight pieces.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to extrusion blown containers. [Background technology]

[0002] In recent years, there has been a need to enhance the design of extrusion-blown containers by imparting a metallic finish (a metallic luster). Known methods for imparting a metallic finish include, for example, painting with a metallic pigment or forming a vapor-deposited film mainly made of metal (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-101942 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a metallic finish is imparted by painting, vapor deposition, or the like, the painting and vapor deposition steps are required, which is time-consuming and likely to increase costs. Furthermore, in order to give extrusion-blow molded containers a unique appearance, there is a need to vary the brightness (shade of color) that can be seen when the extrusion-blow molded container is viewed from different angles around a horizontal axis perpendicular to the axis of the container. However, in this case, it is necessary to incorporate pearl essence into the synthetic resin that forms the extrusion-blow molded container, which tends to increase costs. As described above, there is a problem in that extrusion blown containers with original appearances are difficult to meet the demand for cost reduction.

[0005] The present invention has been made in consideration of the above circumstances, and its object is to provide an extrusion blown container that can have an original appearance while suppressing increases in cost. [Means for solving the problem]

[0006] The extrusion blow container of the present invention is an extrusion blow container having a container body in which a mouth portion, a body portion, and a bottom portion are arranged in this order from top to bottom along the container axial direction, and the container body comprises an outer layer made of a light-transmitting synthetic resin, and an inner layer made of a light-transmitting synthetic resin that is located on the inner surface of the container body closer to the outer layer and contains a plurality of tiny metal pieces formed in the shape of elongated columns or plates, and the tiny metal pieces comprise inclined pieces that extend radially outward as their longitudinal direction goes from top to bottom, and straight pieces that extend along the container axis, and in at least the outer portion of the inner layer that is located radially outward from the radial center, the number of inclined pieces is greater than the number of straight pieces.

[0007] In the extrusion-blow container according to the present invention, the inner layer containing minute metal flakes can be seen from the outside of the container body through the light-transmitting outer layer, and thus the metallic luster effect achieved by utilizing the light reflected by the minute metal flakes can be used to impart a metallic appearance. When the outer layer is colored, the colored outer layer can be visually recognized while giving a metallic feel, and therefore an appearance with a metallic luster can be provided.

[0008] Because the inner layer containing minute metal flakes is formed from a synthetic resin together with the outer layer, a sufficient metallic finish can be imparted as described above when the container body including the outer and inner layers is formed by extrusion blow molding, which involves blow molding a laminated parison. Therefore, unlike methods of imparting a metallic finish using painting, vapor deposition, or the like, this method requires less effort and can be achieved at lower costs. This meets the need for lower costs for containers, making the extrusion blown container suitable for a variety of uses, such as cosmetic containers.

[0009] Among the minute metal pieces located in the outer part of the inner layer, the number of inclined pieces extending radially outward as the longitudinal direction goes from top to bottom is greater than the number of straight pieces extending longitudinally along the container axis. Therefore, when the extrusion blown container is tilted around a horizontal axis perpendicular to the container axis, with the bottom moving closer and the mouth moving away from the body viewed from the radial outside, light incident on the body can easily pass through the inclined pieces that are more numerous among the multiple tiny metal pieces located on the outer part of the inner layer, making it less likely for the light incident on the body to be reflected by the tiny metal pieces, causing it to appear darker than when viewed from the front. On the other hand, when the extrusion blown container is tilted around the horizontal axis from a state in which the body is viewed from the front from the outside in the radial direction so that the bottom moves away and the mouth moves closer, the numerous inclined pieces located on the outer part of the inner layer make it easier for incident light to be reflected onto the body, making it appear brighter than when viewed from the front. From the above, it is possible to vary the visible brightness (shade of color) when the viewing direction of the extrusion-blow container is changed around the horizontal axis, without using pearl essence.

[0010] The minute metal pieces may be formed in the shape of a rectangular parallelepiped or a rectangular plate in plan view.

[0011] In this case, the minute metal pieces are formed in the shape of a rectangular parallelepiped or a rectangular plate in a plan view, so that as the longitudinal direction moves from top to bottom, the inclined pieces extending radially outward can be reliably positioned in large numbers on the outer part of the inner layer during extrusion blow molding.

[0012] In a longitudinal cross-sectional view along the container axis, the inclined piece may have an inclination angle of 10° or more and 70° or less with respect to the container axis.

[0013] In this case, when viewed in a vertical cross section along the container axis, the inclination angle of the inclined piece relative to the container axis is between 10° and 70°, so that the visible light and dark can be reliably changed when the viewing direction of the extrusion blow container is changed around the horizontal axis.

[0014] The container body may include an innermost layer provided closer to the inner surface of the container body than the inner layer.

[0015] In this case, since the container body has an innermost layer located closer to the inner surface of the container body than the inner layer, the inner layer is supported from the inner surface of the container body during extrusion blow molding, making it easy to tilt the inclined piece to the desired angle and preventing the contents from coming into contact with the inner layer containing tiny metal pieces, making it less likely to restrict the type of contents that can be filled into the container body. [Effects of the Invention]

[0016] According to the present invention, an extrusion blown container having an original appearance can be obtained while suppressing increases in cost. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an external view (partial cross-sectional view) showing an extrusion blown container according to an embodiment of the present invention and a comparative example. [Figure 2] 2 is an enlarged photograph of part B shown in FIG. 1 according to an embodiment of the present invention. [Figure 3] 3 is an enlarged photograph of part III shown in FIG. 2. [Figure 4] 2 is an enlarged photograph of a portion B shown in FIG. 1 according to a comparative example of the present invention. [Figure 5] 5 is an enlarged photograph of the V portion shown in FIG. 4. [Figure 6] 10 is a photograph showing the state of the body of each extrusion blow container of an embodiment of the present invention and a comparative example, viewed from the radial outside and in front. [Figure 7] This is a photograph showing the state in which each extrusion-blow container is tilted from the state shown in FIG. 6 around a horizontal axis perpendicular to the container axis, so that the bottoms are closer to each other and the mouths are farther apart. [Figure 8] The photographs show the state in which each extrusion blown container is tilted from the state shown in FIG. 6 around the horizontal axis so that the bottoms are moving away from each other and the mouths are moving closer to each other. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an extrusion blown container according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, the extrusion blow container 1 of this embodiment is made of synthetic resin and includes a cylindrical container body 10 with a bottom that is filled with contents. The container body 10 has a cylindrical mouth 11, a shoulder 12 connected to the mouth 11, a body 13 connected to the shoulder 12, and a bottom 14 connected to the body 13.

[0019] Examples of contents include cosmetics, food, detergents, and pharmaceuticals. For example, cosmetics include emulsions, beauty serums, liquid soaps, and skin creams, and foods include beverages and seasonings. However, the contents are not limited to specific items.

[0020] The mouth 11, shoulder 12, body 13, and bottom 14 are connected in this order with their respective central axes aligned on a common axis. Hereinafter, this common axis will be referred to as the container axis O, with the mouth 11 side along the container axis O being referred to as the upper side and the opposite side being referred to as the lower side. Furthermore, when viewed from the container axis O direction, the direction intersecting the container axis O will be referred to as the radial direction, and the direction going around the container axis O will be referred to as the circumferential direction.

[0021] A male thread portion 11a onto which a cap (not shown) is screwed is formed on the outer peripheral surface of the mouth portion 11 over the entire circumferential length. However, the method of attaching the cap is not limited to screwing, and it may be attached to the mouth portion 11 by, for example, undercut fitting. In this case, a fitting protrusion for undercut fitting of the cap may be formed on the outer peripheral surface of the mouth portion 11 instead of the male thread portion 11a. When attaching the cap to the mouth portion 11 by undercut fitting, the cap may be, for example, a hinged cap. A dispenser having an attached cap may be attached to the mouth portion 11.

[0022] The shoulder 12 is continuous with the lower end of the mouth 11 and extends slightly downward as it extends radially outward from the lower end of the mouth 11. The body 13 is continuous with the radially outer end of the shoulder 12 and extends downward from the radially outer end of the shoulder 12. The bottom 14 is continuous with the lower end of the body 13 and closes the lower end opening of the body 13. The shoulder 12, body 13, and bottom 14 have an elliptical shape when viewed in a plan view from the direction of the container axis O.

[0023] However, the shape of the container body 10 is not limited, and may be changed as appropriate depending on, for example, the capacity of the extrusion blow container 1 or the type of contents. For example, the shape of the body 13 in a plan view from the direction of the container axis O may be circular or angular, and the body 13 may increase in diameter from top to bottom.

[0024] The container body 10 has a laminated structure in which multiple layers are stacked in the thickness direction of the container body 10. As shown in Fig. 2, the container body 10 has an outer layer 21, an adhesive layer 22, an inner layer 23, and an innermost layer 24, which are laminated in this order from the outer surface side to the inner surface side of the container body 10 in a tightly adhered state. The outer layer 21, adhesive layer 22, inner layer 23, and innermost layer 24 are made of a synthetic resin. The outer layer 21, adhesive layer 22, inner layer 23, and innermost layer 24 are made of a synthetic resin such as polyolefin.

[0025] The outer layer 21 is formed of a synthetic resin containing, for example, PCTG resin as a main material, but this synthetic resin only needs to contain PCTG resin in the largest amount, and may contain other synthetic resins or additives. The synthetic resin forming the outer layer 21 is optically transparent. The outer layer 21 is colored and transparent. Alternatively, the outer layer 21 may be colorless and transparent. The thickness of the outer layer 21 is thinner than the thicknesses of the adhesive layer 22, the inner layer 23, and the innermost layer 24. The thickness of the outer layer 21 is, for example, 30 μm or more and 200 μm or less, and preferably 50 μm or more and 150 μm or less. However, the thickness of the outer layer 21 is one example and may be changed as appropriate. For example, the thickness of the outer layer 21 may be greater than the thickness of at least one of the adhesive layer 22, the inner layer 23, and the innermost layer 24.

[0026] The adhesive layer 22 is formed of a synthetic resin containing, for example, modified polyolefin as a main material. However, this synthetic resin only needs to contain the modified polyolefin in the largest amount, and may also contain other synthetic resins or additives. The synthetic resin forming the adhesive layer 22 is optically transparent. The adhesive layer 22 is colorless and transparent. The adhesive layer 22 may also be colored and transparent. The thickness of the adhesive layer 22 is thinner than the thickness of the inner layer 23. The thickness of the adhesive layer 22 is, for example, 20 μm or more and 250 μm or less, and preferably 50 μm or more and 200 μm or less. However, the thickness of the adhesive layer 22 is just an example and may be changed as appropriate. For example, the thickness of the adhesive layer 22 may be greater than or equal to the thickness of the inner layer 23.

[0027] The adhesive layer 22 and the outer layer 21 are optically transparent, so that the inner layer 23 can be seen from the outside of the container body 10 through the outer layer 21 and the adhesive layer 22. The optical transparency required for the outer layer 21 and the adhesive layer 22 is not particularly limited as long as they are able to transmit visible light, but for example, a haze value indicating the degree of cloudiness of 30% or less is preferred. The haze value can be measured using a color difference meter (SZ-Σ80-OS manufactured by Nippon Denshoku Industries Co., Ltd.).

[0028] The innermost layer 24 is formed of a synthetic resin primarily composed of, for example, block polypropylene. However, this synthetic resin only needs to contain the majority of block polypropylene, and may contain other synthetic resins or additives. The thickness of the innermost layer 24 is greater than the thicknesses of the outer layer 21, adhesive layer 22, and inner layer 23. The thickness of the innermost layer 24 is, for example, 250 μm to 600 μm, preferably 300 μm to 500 μm. However, the thickness of the innermost layer 24 is merely an example and may be changed as appropriate. For example, the thickness of the innermost layer 24 may be less than the thickness of at least one of the outer layer 21, adhesive layer 22, and inner layer 23. The innermost layer 24 is colored, opaque, and light-blocking.

[0029] The visible light transmittance of the innermost layer 24 is, for example, 10% or less, preferably 3% or less. However, this light transmittance is just an example and may be changed as appropriate. The light transmittance can be measured in accordance with JIS K7375 using an ultraviolet-visible-near-infrared spectrophotometer (Shimadzu UV-3150).

[0030] The inner layer 23 is formed of a synthetic resin containing, for example, block polypropylene as a main material. However, this synthetic resin only needs to contain the block polypropylene or the like in the largest amount, and may also contain other synthetic resins or additives. The synthetic resin forming the inner layer 23 is optically transparent. The inner layer 23 is colored and transparent. Alternatively, the inner layer 23 may be colorless and transparent. The haze value of the synthetic resin forming the inner layer 23 is higher than the haze values ​​of the synthetic resins forming the outer layer 21 and the adhesive layer 22. The thickness of the inner layer 23 is equal to or less than the thickness of the innermost layer 24. This allows the inner layer 23 to be properly supported by the innermost layer 24 from the inside surface of the container body 10 during extrusion blow molding, making it easy to achieve the desired inclination of the inclined piece 25a (described later). The thickness of the inner layer 23 is, for example, 30 μm to 500 μm, preferably 50 μm to 400 μm. The difference between the thickness of the inner layer 23 and the innermost layer 24 is, for example, 100 μm or less. However, the thickness of the inner layer 23 is an example and may be changed as appropriate. For example, the thickness of the inner layer 23 may be thicker than the thickness of the innermost layer 24, or the difference between the thicknesses of the inner layer 23 and the innermost layer 24 may be greater than 100 μm.

[0031] As shown in Fig. 3, the inner layer 23 contains a plurality of minute metal pieces 25a, 25b formed in the shape of elongated columns or plates. The minute metal pieces 25a, 25b are formed in the shape of rectangular parallelepipeds or rectangular plates in a plan view. The minute metal pieces 25a, 25b are made of, for example, an aluminum alloy. The minute metal pieces 25a, 25b may be made of a material other than an aluminum alloy. The planar shape of the minute metal pieces 25a, 25b is not limited to a rectangular shape, and may be, for example, a shape in which the width in the short side direction narrows from the inside to the outside along the longitudinal direction, and both ends in the longitudinal direction are pointed outward in the longitudinal direction.

[0032] The volume of the minute metal pieces 25a and 25b is, for example, 175 μm 3 More than 1000μm 3 Less than or equal to 250 μm, preferably 3 More than 500μm 3 The volume of the minute metal pieces 25a, 25b is, however, an example and may be changed as appropriate. The minute metal pieces 25a, 25b are formed in a columnar or plate shape having at least an elongated front and back surface, and the length of the longest side of the sides defining these front and back surfaces is, for example, 7 μm or more and 40 μm or less, preferably 10 μm or more and 20 μm or less. Note that these values ​​are an example and may be changed as appropriate. The minute metal pieces 25a, 25b are contained in the inner layer 23 in an amount of 0.75 mass % to 2.50 mass %. The inner layer 23 is formed by extrusion blow molding a synthetic resin to which the minute metal pieces 25a, 25b have been added. As a result, the amount of minute metal pieces 25a, 25b contained per unit volume of the inner layer 23 is uniform throughout the entire inner layer 23.

[0033] In this embodiment, the minute metal pieces 25a, 25b have inclined pieces 25a that extend radially outward as the longitudinal direction goes from top to bottom, and straight pieces 25b that extend along the container axis O. In the inner layer 23, at least in the outer portion located radially outward from the radial center portion, the number of inclined pieces 25a is greater than the number of straight pieces 25b.

[0034] In a vertical cross section taken along the container axis O, the inclination angle of the inclined pieces 25a relative to the container axis O is, for example, 10° to 70°, and preferably 20° to 60°. In a vertical cross section taken along the container axis O, the straight pieces 25b include not only those that extend straight along the container axis O, but also those that are inclined at an angle of less than 10° relative to the container axis O. These values ​​are merely examples and may be changed as appropriate.

[0035] A method for forming the extrusion blow molding container 1 by extrusion blow molding will be described below.

[0036] First, a cylindrical laminated parison is formed by extrusion molding, combining a first layer that will become outer layer 21, a second layer that will become adhesive layer 22, a third layer that will become inner layer 23, and a fourth layer that will become innermost layer 24 (parison formation step). At this time, by adjusting the extrusion pressure of the extruder with respect to the thickness of the third layer that will become inner layer 23, for example, it is possible to position more inclined pieces 25a than straight pieces 25b in the outer portion of the third layer that is located radially outward from at least the radial center portion. Next, the laminated parison is sandwiched between molding dies and placed in the cavity (mold clamping process). Next, pressurized air is supplied (blowed) into the laminated parison to inflate it (blowing process). This pressurizes the outer surface of the laminated parison against the inner surface of the cavity of the molding die, molding the laminated parison into a shape corresponding to the inner surface of the cavity, and obtaining an extrusion blown container 1 having a container body 10.

[0037] Next, an example of the extrusion blow container 1 will be described. However, the present invention is not limited to the following example.

[0038] PCTG resin (product name: EB062, Haze: 6.5% (thickness 1 mm), manufactured by Eastman) was used as the synthetic resin forming the outer layer 21. The thickness of the outer layer 21 was set to about 80 μm. Modified polyolefin (trade name: Modic F503, Haze: 6.5% (thickness 1 mm), manufactured by Mitsubishi Chemical) was used as the synthetic resin forming the adhesive layer 22. The thickness of the adhesive layer 22 was set to about 184 μm. Block polypropylene (product name: B511QA, Haze: 30% (thickness 1 mm), manufactured by Prime Polymer) was used as the synthetic resin forming the inner layer 23. This synthetic resin contained approximately 1.72 mass% of rectangular parallelepiped (20 μm × 5 μm × 5 μm) minute metal pieces 25a, 25b. The thickness of the inner layer 23 was approximately 347 μm. Block polypropylene (product name: B511QA, Haze: 30% (thickness 1 mm), manufactured by Prime Polymer) was used as the synthetic resin forming the innermost layer 24. This synthetic resin contained 8 mass% of a light-blocking material (product name: PPM-2KF868S-CRM-B-FD, manufactured by Toyocolor), so that the visible light transmittance of the innermost layer 24 was 3% or less. The thickness of the innermost layer 24 was approximately 392 μm.

[0039] The laminated parison was formed by extrusion molding using each of the above-mentioned materials, and then the laminated parison was blow molded using a molding die as described above to produce the extrusion blow container 1.

[0040] As a result, by simply performing extrusion blow molding, it was possible to actually produce an extrusion blown container 1 having a unique appearance with a sufficient metallic feel, as shown on the left side of Figure 6. Furthermore, as shown in Figure 3, it was confirmed that the number of inclined pieces 25a was greater than the number of straight pieces 25b in at least the outer portion of the inner layer 23, which is located radially outward from the radial center. In Figure 3, it was confirmed that an average of 3.3 inclined pieces 25a were located within a 50 μm × 50 μm square region A adjacent to the outer surface of the inner layer 23, and that almost no straight pieces 25b were located within the region from the outer surface of the inner layer 23 to a depth of 50 μm.

[0041] Then, as shown on the left side of Figure 6, when the body 13 is viewed from the front from the outside in the radial direction, and the extrusion blow container 1 is tilted around a horizontal axis perpendicular to the container axis O in a direction in which the bottom 14 moves closer and the mouth 11 moves away, as shown on the left side of Figure 7, it was confirmed that, as shown in Figure 3, the incident light L1 on the body 13 is more likely to pass through the inclined pieces 25a, which are more numerous among the multiple minute metal pieces 25a, 25b located in the outer part of the inner layer 23, and therefore the incident light L1 on the body 13 is less likely to be reflected by the minute metal pieces 25a, 25b, and the body appears darker than when viewed from the front.

[0042] On the other hand, when the extrusion blown container 1 is tilted around the horizontal axis from the state in which the body 13 is viewed from the radial outside as shown on the left side of Figure 6, so that the bottom 14 moves away and the mouth 11 moves closer, as shown on the left side of Figure 8, it was confirmed that the incident light L2 on the body 13 is more likely to be strongly reflected by the inclined pieces 25a, which are in greater number among the multiple tiny metal pieces 25a, 25b located in the outer part of the inner layer 23, as shown in Figure 3, making it appear brighter than when viewed from the front.

[0043] Next, a comparative example of an extrusion blown container 100 shown in FIGS. 1, 4 and 5 will be described.

[0044] In the extrusion blown container 100 of the comparative example, only the thicknesses of the outer layer 121, adhesive layer 122, inner layer 123, and innermost layer were different from those of the above-described example.

[0045] Even in the extrusion blown container 100 of this comparative example, as shown on the right side of FIG. 6, it was possible to provide a sufficient metallic appearance. However, as shown in Fig. 5, it was confirmed that the number of inclined pieces 25a was smaller than the number of straight pieces 25b in at least the outer portion of the inner layer 123 that was located radially outward from the radial center. In Fig. 5, it was confirmed that an average of 1.3 inclined pieces 25a were located within a 50 μm × 50 μm square region A that was in contact with the outer peripheral surface of the inner layer 123, and that in the region from the outer peripheral surface of the inner layer 123 to a depth of 50 μm, there were more straight pieces 25b than inclined pieces 25a.

[0046] In this extrusion blow container 100, when the body 13 is viewed from the front from the outside in the radial direction as shown on the right side of Figure 6, and the extrusion blow container 100 is tilted about the horizontal axis in a direction in which the bottom moves closer and the mouth moves away, as shown on the right side of Figure 7, and when the extrusion blow container 100 is tilted in a direction in which the bottom moves away and the mouth moves closer, as shown on the right side of Figure 8, it was confirmed that the ease with which incident light hits the body 13 relative to the tiny metal pieces 25a, 25b, i.e., the intensity of the reflected light, does not change, and therefore the brightness does not change much.

[0047] As described above, according to the extrusion-blow container 1 of this embodiment, the inner layer 23 containing the minute metal pieces 25a, 25b can be seen from the outside of the container body 10 through the light-transmitting outer layer 21. Therefore, a metallic appearance can be imparted by the effect of metallic luster that utilizes the light reflected by the minute metal pieces 25a, 25b. Since the outer layer 21 is colored and transparent, the colored outer layer 21 can be seen while giving a metallic feel, and therefore an external appearance with a metallic luster can be provided.

[0048] Because the inner layer 23 containing the minute metal pieces 25a, 25b is formed from a synthetic resin together with the outer layer 21, a sufficient metallic finish can be imparted as described above when the container body 10 including the outer layer 21 and the inner layer 23 is formed by extrusion blow molding, which involves blow molding a laminated parison. Therefore, unlike when a metallic finish is imparted by painting, vapor deposition, or the like, this method does not require much effort and can reduce costs. This meets the need for low cost containers, and the extrusion blown container 1 can be suitably used for a variety of applications, such as cosmetic containers.

[0049] Of the tiny metal pieces 25a, 25b located in the outer portion of the inner layer 23, the number of inclined pieces 25a that extend radially outward as the longitudinal direction goes from top to bottom is greater than the number of straight pieces 25b that extend longitudinally along the container axis O.Therefore, as mentioned above, the visible brightness (shade of color) can be made to differ when the viewing direction of the extrusion blow container 1 is changed around the horizontal axis, without using pearl essence. As a result, it is possible to obtain an extrusion blown container 1 that has an original appearance while suppressing increases in cost.

[0050] Since the minute metal pieces 25a, 25b are formed in the shape of a rectangular parallelepiped or a rectangular plate in a plan view, the inclined pieces 25a, which extend radially outward as the longitudinal direction goes from top to bottom, can be reliably positioned in large numbers in the outer part of the inner layer 23 during extrusion blow molding.

[0051] When viewed in a vertical cross section along the container axis O, the inclination angle of the inclined piece 25a relative to the container axis O is 10° or more and 70° or less, so that the light and dark that can be seen when the viewing direction of the extrusion blow container 1 is changed around the horizontal axis can be reliably made different.

[0052] Since the container body 10 has an innermost layer 24 provided on the inner surface side of the container body 10 relative to the inner layer 23, the inner layer 23 is supported from the inner surface side of the container body 10 during extrusion blow molding, making it easy to tilt the inclined piece 25a to the desired angle and preventing the contents from coming into contact with the inner layer 23 containing the minute metal pieces 25a, 25b, making it less likely to impose restrictions on the type of contents that can be filled into the container body 10.

[0053] The present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the invention.

[0054] For example, another layer may be disposed closer to the inner surface of the container body 10 than the inner layer 23. For example, the other layer may be configured to be peelably laminated on the inner surface of the inner layer 23 and to be capable of shrinking and deforming as the contents decrease. When configured in this way, the container body 10 can be used as a delaminating container (delamination bottle). The container body 10 may not have the adhesive layer 22 and the innermost layer 24 .

[0055] The container body 10 may have another layer disposed between the inner layer 23 and the innermost layer 24. In this case, the thickness of the other layer continuing from the inner surface of the container body 10 to the inner layer 23 may be equal to or greater than the thickness of the inner layer 23. Even in this configuration, the inner layer 23 is appropriately supported by the other layer from the inner surface of the container body 10 during extrusion blow molding, and the inclined piece 25a can easily be inclined to the desired angle.

[0056] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0057] 1...Extrusion blown container 10...Container body 11...Mouth 13...Torso 14...Bottom 21...outer layer 22...adhesive layer 23...Inner layer 24...innermost layer 25a...Minute metal piece, inclined piece 25b…Minute metal piece, straight piece O…Container axis

Claims

1. An extrusion blown container having a container body in which a mouth portion, a body portion, and a bottom portion are arranged in this order from top to bottom along the container axial direction, The container body is an outer layer made of a light-transmitting synthetic resin; an inner layer made of a light-transmitting synthetic resin, the inner layer being disposed closer to the inner surface of the container body than the outer layer and containing a plurality of minute metal pieces formed in the shape of elongated columns or plates; In the body portion, the minute metal pieces have an inclined piece extending radially outward as the longitudinal direction goes from top to bottom, and a straight piece extending along the container axis, In the inner layer, at least in an outer portion located radially outward from a central portion in the radial direction, the number of the inclined pieces is greater than the number of the straight pieces, When viewed in a vertical cross section along the container axis, the inclination angle of the inclined piece with respect to the container axis is 10° or more and 70° or less, When viewed in the vertical cross section, the inclination angle of the straight piece with respect to the container axis is greater than or equal to 0° and less than 10°, When the extrusion blow container is tilted around a horizontal axis perpendicular to the container axis so that the bottom moves closer and the mouth moves farther away from the body when viewed from the front radially outside, the container appears darker than when viewed from the front, and when the extrusion blow container is tilted so that the bottom moves farther away from the mouth and the container appears brighter than when viewed from the front.

2. The extrusion-blow container according to claim 1 , wherein the minute metal pieces are formed in the shape of a rectangular parallelepiped or a rectangular plate in a plan view.

3. 3. The extrusion-blow container according to claim 1, wherein the container body has an innermost layer provided closer to the inner surface of the container body than the inner layer.

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