JP7547744B2 - Composite container and method for manufacturing the same - Google Patents

Description

This disclosure relates to a composite container and a method for manufacturing a composite container.

Recently, plastic bottles have become common for storing liquid contents such as food and beverages, and these plastic bottles store liquid contents.

Plastic bottles that contain such liquid contents are manufactured by inserting a preform into a mold and performing biaxial stretch blow molding.

In conventional biaxial stretch blow molding methods, a preform containing a single-layer material such as PET or PP, a multilayer material, or a blended material is molded into a container shape. However, in conventional biaxial stretch blow molding methods, it is common to simply mold the preform into a container shape. For this reason, when endowing the container with various functions or properties (barrier properties, heat retention, etc.), the means for doing so are limited, for example by changing the material that constitutes the preform. In particular, it is difficult to endow different parts of the container (for example, the body or the bottom) with different functions or properties.

In response to this, the applicant has proposed in Patent Document 1 a composite container that can be given various functions and characteristics.

JP 2015-128858 A

The plastic members of the composite container described above are not welded or bonded to the container body, so they can be separated (peeled) and removed from the container body, allowing the container body to be recycled. However, the plastic members are provided so as to be in close contact with the container body, and there is room for improvement in their separability from the container body.

The present disclosure has been made in consideration of these points, and aims to provide a composite container and a method for manufacturing a composite container that can improve the separability of the plastic member provided on the outside of the container body.

A composite container according to one embodiment comprises a container body having a mouth, a neck, a body, and a bottom, and a plastic member attached in intimate contact with the outside of the container body, wherein a linearly extending protrusion is formed on at least one of the neck, body, and bottom of the container body, and a cut that penetrates the plastic member is formed at a position of the plastic member that corresponds to the protrusion, and the cut has a wave shape.

In one embodiment of the composite container, at least a portion of the cutout may cross the base line of the protrusion.

In one embodiment of the composite container, the protrusion may be formed on the bottom and extend in an annular shape.

In one embodiment of the composite container, the cutout portion may have an overall arc shape.

In one embodiment of the composite container, the protrusion may be formed on at least one of the neck and the body, and may extend linearly.

In one embodiment of the composite container, the cut portion may have a linear shape overall.

A method for manufacturing a composite container according to one embodiment includes the steps of preparing a preform, providing a plastic member on the outside of the preform, blow molding the preform and the plastic member to expand the preform and the plastic member as a unit, and fabricating a container body corresponding to the preform and a plastic member provided in close contact with the outside of the container body, and forming a cut portion that penetrates the plastic member in the plastic member after blow molding. In the step of fabricating the container body corresponding to the preform and the plastic member provided in close contact with the outside of the container body, a linearly extending protrusion is formed on at least one of the neck, body, and bottom of the container body, and in the step of forming the cut portion, the cut portion is formed at a position corresponding to the protrusion, and the cut portion has a wave shape.

In one embodiment of the method for manufacturing a composite container, in the step of forming the cut portion, the cut portion may be formed by a laser.

According to the present disclosure, it is possible to improve the separability of the plastic member provided on the outside of the container body.

FIG. 1 is a partial vertical sectional view showing a composite container according to one embodiment. FIG. 2 is a horizontal cross-sectional view (cross-sectional view taken along line II-II in FIG. 1) showing a composite container according to one embodiment. FIG. 3 is a bottom view showing a composite container according to one embodiment. FIG. 4 is a vertical sectional view (sectional view taken along line IV-IV in FIG. 3) showing a composite container according to one embodiment. FIG. 5 is an enlarged view showing a composite container according to one embodiment (an enlarged view corresponding to part V in FIG. 3). 6(a)-(b) are vertical cross-sectional views showing a composite container according to one embodiment. FIG. 7 is a partial vertical cross-sectional view showing a composite preform for manufacturing a composite container according to one embodiment. FIG. 8 is a horizontal cross-sectional view (cross-sectional view taken along line VIII-VIII in FIG. 7) showing a composite preform for producing a composite container according to one embodiment. 9(a)-(d) are perspective views showing various plastic members. 10(a)-(f) are schematic diagrams showing a method for manufacturing a composite container according to one embodiment. 11(a) and 11(b) are cross-sectional views illustrating a method for removing a plastic member in a composite container according to one embodiment. 12(a) and 12(b) are bottom views for explaining a method for removing a plastic member in a composite container according to one embodiment. FIG. 13 is a bottom view showing a modified example of the composite container according to the embodiment. FIG. 14 is a bottom view showing a modified example of the composite container according to the embodiment. FIG. 15 is a bottom view showing a modified example of the composite container according to the embodiment. FIG. 16 is a bottom view showing a modified example of the composite container according to the embodiment. FIG. 17 is a bottom view showing a modified example of the composite container according to the embodiment. FIG. 18 is a front view showing a modified example of the composite container according to the embodiment. FIG. 19 is a vertical sectional view (sectional view taken along line XIX-XIX in FIG. 18) showing a modified example of the composite container according to the embodiment. FIG. 20 is a front view showing a modified example of the composite container according to the embodiment. FIG. 21 is a vertical sectional view (sectional view taken along line XXI-XXI in FIG. 20) showing a modified example of the composite container according to one embodiment.

An embodiment will be described below with reference to the drawings. Figures 1 to 12 are diagrams showing an embodiment. Each of the figures shown below is a schematic diagram. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, appropriate modifications can be made without departing from the technical concept. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values such as dimensions and material names of each member described in this specification are examples of an embodiment, and are not limited to these, and can be selected and used as appropriate. In this specification, terms that specify shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are intended to include substantially the same state in addition to their strict meanings.

Configuration of Composite Container First, an outline of the composite container according to this embodiment will be described with reference to Figs.
In this specification, "upper" and "lower" refer to the upper and lower sides, respectively, when the composite container 10A is held upright (FIG. 1).

The composite container 10A shown in Figures 1 to 6 is obtained by performing biaxial stretch blow molding on a composite preform 70 (see Figures 7 and 8) including a preform 10a and a plastic member 40a using a blow molding die 50, as described below, to expand the preform 10a and the plastic member 40a of the composite preform 70 as a unit.

Such a composite container 10A comprises a container body 10 made of a plastic material located on the inside, and a plastic member 40 provided in close contact with the outside of the container body 10.

The container body 10 has a mouth 11, a neck 13 provided below the mouth 11, a body 20 provided below the neck 13, and a bottom 30 provided below the body 20.

On the other hand, the plastic member 40 is thinly stretched and adhered to the outer surface of the container body 10, and is attached in a manner that does not allow it to move or rotate easily relative to the container body 10.

Next, the container body 10 will be described in detail. As described above, the container body 10 has a mouth portion 11, a neck portion 13, a body portion 20, and a bottom portion 30.

The mouth portion 11 has a threaded portion 14 that is screwed onto a cap (not shown), and a flange portion 17 provided below the threaded portion 14. The shape of the mouth portion 11 may be a conventionally known shape. The container body 10 is filled with contents such as a liquid content, and a cap (not shown) is screwed onto the mouth portion 11 to produce a composite container 10A containing the contents.

The neck portion 13 is located between the flange portion 17 and the body portion 20 and has a generally cylindrical shape with a generally uniform diameter.

The body 20 has a first portion 21 having a shape in which the diameter gradually increases from the neck 13 side toward the bottom 30 side (a shape in which the area gradually increases in horizontal cross section), and a second portion 22 provided below the first portion 21 and having a generally uniform diameter. Of these, the second portion 22 has a cylindrical shape. However, this is not limited thereto, and the second portion 22 of the body 20 may have a polygonal cylindrical shape such as a rectangular cylindrical shape or an octagonal cylindrical shape. Alternatively, the second portion 22 of the body 20 may have a cylindrical shape with a non-uniform horizontal cross section from top to bottom. The outer surface of the body 20 may have irregularities such as vacuum absorption panels or grooves.

The bottom 30 has a recess 31 located in the center and a grounding portion 32 provided around the recess 31. The outer surface 31a of the recess 31 is curved upwardly with a substantially constant radius of curvature, except for the area where the protrusion 33 described below is formed. The shape of the bottom 30 is not particularly limited, and may have a conventionally known bottom shape (for example, a petaloid bottom shape or a rounded bottom shape).

As shown in Figs. 3 and 4, a linearly extending protrusion 33 is formed in the recess 31 of the bottom 30. In this embodiment, the protrusion 33 extends in an annular shape and is formed around the entire circumference of the recess 31 of the bottom 30. Note that the protrusion 33 may be formed only in a portion of the recess 31 of the bottom 30 in the circumferential direction.

As shown in FIG. 4, the protrusion 33 includes a first inclined surface 34, a second inclined surface 35 located radially inward from the first inclined surface 34, and a connecting surface 36 connecting the first inclined surface 34 and the second inclined surface 35. The first inclined surface 34 inclines radially inward as it extends downward, and the second inclined surface 35 inclines radially inward as it extends upward. On the other hand, the connecting surface 36 is approximately parallel to the horizontal plane (a plane perpendicular to the central axis of the container body 10).

Such protrusions 33 are formed during blow molding by providing recesses on the inner surface of the bottom mold 50c of the blow molding die 50. In this case, a depression 37 corresponding to the protrusions 33 is formed on the inner surface of the bottom 30 of the container body 10. Note that in FIG. 4, the recesses 31 of the bottom 30 when the protrusions 33 are not formed are shown by two-dot chain lines (phantom lines).

The thickness of the container body 10 at the trunk 20 can be, for example, thinned to about 50 μm or more and 250 μm or less, but is not limited to this. The thickness of the container body 10 at the bottom 30 can be, for example, thinned to about 0.15 mm or more and 2.0 mm or less, but is not limited to this. Furthermore, the weight of the container body 10 can be, for example, thinned to about 10 g or more and 20 g or less, but is not limited to this. By thinning the thickness of the container body 10 in this way, the weight of the container body 10 can be reduced.

Such a container body 10 can be produced by biaxially stretching and blow molding a preform 10a (described later) produced by injection molding a synthetic resin material. The material of the container body 10 is preferably a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PC (polycarbonate). The container body 10 may be colored in colors such as red, blue, yellow, green, brown, black, and white, but is preferably colorless and transparent in consideration of ease of recycling. The above-mentioned various resins may also be blended. Furthermore, a vapor deposition film such as a diamond-like carbon film or a silicon oxide thin film may be formed on the inner surface of the container body 10 to enhance the barrier properties of the container.

The container body 10 can also be formed as a multi-layered bottle with two or more layers. That is, by injection molding, for example, a preform 10a consisting of three or more layers is injection molded with an intermediate layer of a resin (intermediate layer) having gas barrier properties such as MXD6, MXD6 + fatty acid salt, PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer), or PEN (polyethylene naphthalate), and then blow molded to form a multi-layered bottle with gas barrier properties. Note that the intermediate layer may be a resin that is a blend of the various resins described above.

Alternatively, a foamed preform having a foam cell diameter of 0.5 μm or more and 100 μm or less may be molded by mixing an inert gas (nitrogen gas, argon gas) with a melt of a thermoplastic resin, and then blow molding this foamed preform to produce the container body 10. Since such a container body 10 has built-in foam cells, the light blocking properties of the entire container body 10 can be improved.

Such a container body 10 may be, for example, a bottle with a full capacity of 100 ml to 2000 ml. Alternatively, the container body 10 may be a large bottle with a full capacity of, for example, 10 L to 60 L.

Next, the plastic member 40 will be described. As described below, the plastic member 40 (40a) is provided so as to surround the outside of the preform 10a, and is obtained by being attached to the outside of the preform 10a and then being biaxially stretched and blow molded together with the preform 10a.

The plastic member 40 is attached to the outer surface of the container body 10 without being glued, and is in close contact with the container body 10 so that it does not move or rotate relative to the container body 10. This plastic member 40 is thinly stretched over the outer surface of the container body 10 and covers the container body 10. As shown in FIG. 2, the plastic member 40 is provided over the entire circumferential area so as to surround the container body 10, and has a horizontal cross section that is approximately circular.

In this case, the plastic member 40 is provided to cover the neck 13, body 20, and bottom 30 of the container body 10, excluding the mouth 11. This allows the neck 13, body 20, and bottom 30 of the container body 10 to be given the desired functions and characteristics.

The plastic member 40 may be provided on the entire or partial area of the container body 10 other than the mouth 11. For example, the plastic member 40 may be provided so as to cover the entire body 20 and bottom 30 of the container body 10, excluding the mouth 11 and neck 13. Alternatively, the plastic member 40 may be provided so as to cover the body 20 and bottom 30 of the container body 10, excluding the mouth 11, neck 13, and the center of the bottom 30.

Such a plastic member 40 may be one that does not have a shrinking effect on the preform 10a, or it may be one that has a shrinking effect.

When the plastic member 40 has the ability to shrink relative to the preform 10a, the plastic member 40 is provided on the outside of the preform 10a, heated together with the preform 10a, and biaxially stretched and blow molded to obtain the plastic member 40.

The plastic member 40 is not welded or bonded to the container body 10, and can therefore be peeled off and removed from the container body 10. Meanwhile, as shown in Figures 3 to 5, a cut portion 45 penetrating the plastic member 40 is formed in the plastic member 40. By forming the cut portion 45 in the plastic member 40, the plastic member 40 can be separated from the cut portion 45, and the plastic member 40 can be easily separated and removed from the surface of the container body 10. This makes it easier to recycle the container body 10 in the composite container 10A.

In this embodiment, the cut portion 45 is formed at a position corresponding to the bottom 30 of the container body 10. By forming the cut portion 45 at a position of the plastic member 40 corresponding to the bottom 30 of the container body 10, it is possible to prevent the appearance of the composite container 10A from being damaged. In addition, the thickness of the bottom 30 is generally greater than the thickness of the body 20. Therefore, by forming the cut portion 45 at a position corresponding to the bottom 30 of the container body 10, as described below, even if the container body 10 is scratched when forming the cut portion 45 with a laser, it is possible to prevent a defect in which a hole is formed in the container body 10. As a result, it is possible to effectively prevent the defect in which the contents leak from the composite container 10A.

The notch 45 is formed in the plastic member 40 at a position corresponding to the protrusion 33. The notch 45 is formed radially outward from the second inclined surface 35 of the protrusion 33 (see FIG. 5). As shown in FIGS. 3 and 5, the notch 45 has a wavy shape. Since the notch 45 is formed in the plastic member 40 at a position corresponding to the protrusion 33 and has a wavy shape, as described below, the user can hook the toe of his/her finger on the protrusion 33, and the notch 45 can be used as a trigger to easily break the plastic member 40.

However, for example, as shown in FIG. 6(a), if the cutout 45 is too far away from the protrusion 33 (e.g., radially outward), even if the user hooks the toe of the protrusion 33, it is difficult to break the plastic member 40 using the cutout 45 as a trigger. That is, when the user hooks the toe of the protrusion 33, the user's toe gets caught on the first inclined surface 34 or the second inclined surface 35 of the protrusion 33. Therefore, if the cutout 45 is too far away from the protrusion 33, the user's toe gets caught at a position away from the cutout 45, making it difficult to break the plastic member 40 using the cutout 45 as a trigger. This makes it difficult to peel the plastic member 40 from the container body 10.

For example, as shown in FIG. 6(b), even if the notch 45 is formed on the connecting surface 36 of the protrusion 33, when a user hooks the toe of the protrusion 33, the toe of the user will hook at a position away from the notch 45, making it difficult to break the plastic member 40 using the notch 45 as a trigger. For this reason, it is required to form the notch 45 at a desired position on the protrusion 33, and in this case, high processing precision is required when forming the notch 45.

In contrast, in this embodiment, the cut portion 45 has a wavy shape. This allows at least a part of the cut portion 45 to be formed at a desired position relative to the protrusion 33. In other words, since the cut portion 45 has a wavy shape, at least a part of the cut portion 45 can be easily formed near the base line 38a (or the base line 38b) of the protrusion 33 described later without requiring high processing accuracy. Therefore, when a user hooks his or her fingernail on the part of the protrusion 33 that extends in an annular shape where the cut portion 45 is formed near the base line 38a, the plastic member 40 can be easily broken using the cut portion 45 formed near the base line 38a as a trigger. In addition, since the cut portion 45 has a wavy shape, the cut portion 45 can be made noticeable, and the user can easily recognize the cut portion 45.

In this case, as shown in FIG. 5, at least a part of the cut portion 45 straddles the base line 38a of the protrusion 33. This allows at least a part of the cut portion 45 to be reliably formed at a desired position relative to the protrusion 33. However, as a result of various studies conducted by the inventors, it has been found that in order for a user to easily break the plastic member 40 by hooking the toe of the protrusion 33, it is preferable that the cut portion 45 is formed near the base line 38a of the protrusion 33 and that the first inclined surface 34 of the protrusion 33 is covered by the plastic member 40 (see FIG. 4). In contrast, by having at least a part of the cut portion 45 straddle the base line 38a of the protrusion 33, the cut portion 45 is formed near the base line 38a of the protrusion 33 and the part where the first inclined surface 34 of the protrusion 33 is covered by the plastic member 40 can be reliably formed. In this specification, the "base line 38a" refers to a point located radially outward from the protrusion 33 in a vertical cross section, and is a line that circumferentially connects points on the outer surface 31a of the recess 31 of the bottom 30 where the curvature changes (parts that bend in cross section). The "base line 38b" refers to a point located radially inward from the protrusion 33 in a vertical cross section, and is a line that circumferentially connects points on the outer surface 31a of the recess 31 of the bottom 30 where the curvature changes (parts that bend in cross section).

The cutout 45 has a pair of ends 45a, 45b, and has an overall arc shape. As a result, the cutout 45 is formed to follow the protrusion 33 that extends in an annular shape. This allows many parts of the cutout 45 to be positioned at the desired position relative to the protrusion 33. In this specification, "having an overall arc shape" means that in the wave shape of the cutout 45, the curve that smoothly connects the apexes of the peaks and the curve that smoothly connects the apexes of the valleys are each approximately arc shaped, and the centers of each approximately arc shape (hereinafter simply referred to as center O) are aligned with each other.

In addition, in the arc shape formed by the cut portion 45, the central angle θ is preferably 180° or less. This makes it possible to prevent the plastic member 40 from being rolled up from the bottom portion 30 of the container body 10 starting from the cut portion 45 during transportation of the composite container 10A, etc. This central angle θ may be, for example, 45°. The central angle θ may be less than 45°, for example, 30°. Furthermore, multiple cut portions 45 may be formed in the bottom portion 30. In this specification, the "arc" of the arc shape formed by the cut portion 45 means an arc with a radius of two straight lines L1 and L2 (see dashed lines in Figure 5) passing through the center O and the ends 45a and 45b.

Incidentally, a breakage planned line 46 (see the two-dot chain line in FIG. 3 and FIG. 5) extends from the cut portion 45, which is broken when the plastic member 40 is peeled off and removed from the container body 10. In the illustrated example, two breakage planned lines 46 extend from the cut portion 45. The breakage planned lines 46 extend from the pair of ends 45a, 45b, respectively, and extend in a direction perpendicular to the straight line L3 connecting the pair of ends 45a, 45b of the cut portion 45. Specifically, the breakage planned line 46 extends in a direction perpendicular to the straight line L3, from the ends 45a, 45b of the cut portion 45 toward the center O. In this specification, the "breakage planned line" means a line indicating a path along which the breakage of the plastic member 40 is expected to proceed when the plastic member 40 is broken starting from the cut portion 45. The breakage planned line 46 may or may not be distinguishable from other parts of the plastic member 40. When the planned break line 46 can be distinguished from other parts of the plastic member 40, the planned break line 46 may be made distinguishable from the other parts by processing such as half-cutting, or may be made distinguishable from the other parts by a pattern or color. Note that half-cutting refers to thinning the plastic member 40 from the outer surface side, or forming a cut in the plastic member 40 from the outer surface side that does not penetrate the plastic member 40.

In addition, a peeling assist line 47 consisting of a half cut is formed on the plastic member 40. This peeling assist line 47 is a line that breaks when the plastic member 40 is peeled and removed from the container body 10, and serves to change the direction of the breakage of the plastic member 40 that begins with the cut portion 45. By forming such a peeling assist line 47 consisting of a half cut, the direction of the breakage of the plastic member 40 can be easily changed while preventing scratches from being formed on the container body 10.

The peel assist line 47 is formed at a position away from the cut portion 45 and intersects with the planned break line 46 described above. Since the peel assist line 47 intersects with the planned break line 46, the break of the plastic member 40 progresses along the planned break line 46 until it reaches the intersection of the planned break line 46 and the peel assist line 47, and then the break continues along the peel assist line 47.

In this embodiment, two peeling assist lines 47 are formed on the plastic member 40. Each peeling assist line 47 extends outside the cut portion 45. In this specification, "outside the cut portion 45" means the side away from the line L4, which is perpendicular to the line L3 and passes through the midpoint that bisects the pair of ends 45a, 45b, as shown in FIG. 5. Since each peeling assist line 47 extends outside the cut portion 45, when the plastic member 40 breaks along the peeling assist lines 47, the breakage of the plastic member 40 can proceed in a direction in which the width W of the peeled piece P, which will be described later, increases.

Furthermore, at least a portion of each peel assist line 47 is formed to be located radially inward from the cut portion 45, which has an overall arc shape. In this case, at least a portion of the peel assist line 47 is formed at a position where the cut portion 45 overlaps with the sector shape that forms an arc (i.e., an arc with the straight lines L1 and L2 as its radius). This allows the breakage of the plastic member 40 to proceed along the peel assist line 47 even if the breakage of the plastic member 40 deviates from the planned breakage line 46.

Examples of the plastic member 40 include polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, poly-4-methylpentene-1, polystyrene, AS resin, ABS resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, diallyl phthalate resin, fluorine-based resin, polymethyl methacrylate, polyacrylic acid, polymethyl acrylate, polyacrylonitrile, polyacrylamide, polybutadiene, polybutene-1, polyisoprene, polychloroprene, ethylene propylene rubber, butyl rubber, and nitrile. Examples of the resin include rubber, acrylic rubber, silicone rubber, fluororubber, nylon 6, nylon 6,6, aromatic polyamide, polycarbonate, polyethylene terephthalate, butylene polyethylene terephthalate, ethylene polynaphthalate, U polymer, liquid crystal polymer, modified polyphenylene ether, polyether ketone, polyether ether ketone, unsaturated polyester, alkyd resin, polyimide, polysulfone, polyphenylene sulfide, polyether sulfone, silicone resin, polyurethane, phenolic resin, urea resin, polyethylene oxide, polypropylene oxide, polyacetal, epoxy resin, etc. Among these, it is preferable to use thermoplastic non-elastic resins such as polyethylene (PE) such as low density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc. In addition, blend materials, multi-layer structures, and partially multi-layer structures of these may be used. Furthermore, various additives may be added to the material of the plastic member 40 in addition to the main component resin, as long as the characteristics are not impaired. Examples of additives that can be added include plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weather resistance agents, antistatic agents, thread friction reducers, slip agents, mold release agents, antioxidants, ion exchange agents, and color pigments. In addition, by mixing an inert gas (nitrogen gas, argon gas) with the molten thermoplastic resin, a foamed material with a foam cell diameter of 0.5 μm to 100 μm can be used and this foamed preform can be molded to improve light blocking properties.

The plastic member 40 may be made of a material that has light barrier properties that block invisible light such as ultraviolet light. In this case, the light barrier properties of the composite container 10A can be improved and the liquid content can be prevented from deteriorating due to ultraviolet light, etc., without using a multi-layer preform or a preform containing a blended material as the preform 10a. Such materials include blended materials, or materials in which a light-shielding resin is added to PET, PE, or PP. A foamed member with a foam cell diameter of 0.5 μm to 100 μm, which is made by mixing an inert gas (nitrogen gas, argon gas) with a molten thermoplastic resin, may also be used.

The plastic member 40 may be made of a material with higher cold insulation or heat insulation properties (material with lower thermal conductivity) than the plastic material constituting the container body 10 (preform 10a). In this case, it is possible to make it difficult for the temperature of the content liquid to be transmitted to the surface of the composite container 10A without increasing the thickness of the container body 10 itself. This improves the cold insulation or heat insulation properties of the composite container 10A. In addition, when a user grasps the composite container 10A, it is prevented from becoming difficult to hold the composite container 10A due to it being too cold or too hot. Such materials include foamed polyurethane, polystyrene, PE (polyethylene), PP (polypropylene), phenolic resin, polyvinyl chloride, urea resin, silicone, polyimide, melamine resin, etc. It is preferable to mix hollow particles into a resin material containing these resins. The average particle diameter of the hollow particles is preferably 1 μm or more and 200 μm or less, and more preferably 5 μm or more and 80 μm or less. The term "average particle size" means the volume average particle size, and can be measured by a known method using a particle size distribution/particle size distribution measuring device (for example, Nanotrack particle size distribution measuring device, manufactured by Nikkiso Co., Ltd.). The hollow particles may be organic hollow particles made of resin or inorganic hollow particles made of glass, but organic hollow particles are preferred because of their excellent dispersibility. Examples of resins constituting organic hollow particles include styrene resins such as crosslinked styrene-acrylic resins, (meth)acrylic resins such as acrylonitrile-acrylic resins, phenolic resins, fluorine resins, polyamide resins, polyimide resins, polycarbonate resins, and polyether resins. Commercially available hollow particles such as Ropeake HP-1055, Ropeake HP-91, Ropeake OP-84J, Ropeake Ultra, Ropeake SE, and Ropeake ST (manufactured by Rohm and Haas Co., Ltd.), Nipol MH-5055 (manufactured by Zeon Corporation), SX8782, and SX866 (manufactured by JSR Corporation) can also be used. The content of the hollow particles is preferably 0.01 parts by mass or more and 50 parts by mass or less, and more preferably 1 part by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the resin material contained in the plastic member 40.

The plastic member 40 may be made of a material that is less slippery than the plastic material that constitutes the container body 10 (preform 10a). In this case, it is possible to make it easier for the user to grip the composite container 10A without changing the material of the container body 10.

The plastic member 40 may be colored in a color such as red, blue, yellow, green, brown, black, or white, and may be transparent or opaque.

The thickness of the plastic member 40 is not limited to this, but can be, for example, about 5 μm or more and 500 μm or less when attached to the container body 10.

Configuration of the Composite Preform Next, the configuration of the composite preform will be described with reference to Figs.

As shown in Figures 7 and 8, the composite preform 70 comprises a preform 10a made of a plastic material and a bottomed cylindrical plastic member 40a provided on the outside of the preform 10a.

The preform 10a has a mouth portion 11a, a body portion 20a connected to the mouth portion 11a, and a bottom portion 30a connected to the body portion 20a. Of these, the mouth portion 11a corresponds to the mouth portion 11 of the container body 10 described above, and has approximately the same shape as the mouth portion 11. The body portion 20a corresponds to the neck portion 13 and body portion 20 of the container body 10 described above, and has an approximately cylindrical shape. The bottom portion 30a corresponds to the bottom portion 30 of the container body 10 described above, and has an approximately hemispherical shape.

The plastic member 40a is attached to the outer surface of the preform 10a without being glued, and is in close contact with the preform 10a so that it does not move or rotate relative to the preform 10a, or so that it does not fall under its own weight. The plastic member 40a is provided over the entire circumferential area surrounding the preform 10a, and has a circular horizontal cross section.

In this case, the plastic member 40a is provided to cover the entire body portion 20a and the entire bottom portion 30a of the preform 10a.

The plastic member 40a may be provided on the entire area or a part of the area other than the mouth portion 11a. Alternatively, the plastic member 40a may be provided so as to cover the body portion 20a except for the bottom portion 30.

Such a plastic member 40a may be one that does not have a shrinking effect relative to the preform 10a, or it may be one that has a shrinking effect.

When the plastic member 40a has a contracting effect, the plastic member 40a may be one that contracts (e.g., thermally contracts) relative to the preform 10a when an external action (e.g., heat) is applied to it. Alternatively, the plastic member 40a may itself have contractibility or elasticity and be capable of contracting without the application of an external action.

If the plastic member 40a has a thermal contraction effect, after fitting the cylindrical plastic member 40a into the preform 10a, the margin formed at the lower end of the plastic member 40a (the end opposite the mouth portion 11a) may be thermally compressed.

The plastic member 40a may be, for example, a direct blow tube made by direct blow molding, a sheet molded tube made by sheet molding, an extrusion tube made by extrusion molding, an injection molded tube made by injection molding, or an inflation molded tube made by inflation molding, but is not limited to these, and molding methods other than those mentioned above may also be used.

The plastic member 40a may be colored in colors such as red, blue, yellow, green, brown, black, white, etc., and may be transparent or opaque.

Next, we will explain the shape of the plastic member 40a.

As shown in FIG. 9(a), the plastic member 40a may be cylindrical with a bottom as a whole, and may have a cylindrical body 41 and a bottom 42 connected to the body 41. In this case, the bottom 42 of the plastic member 40a covers the bottom 30a of the preform 10a, so that various functions and characteristics such as barrier properties can be imparted to the bottom 30 as well as the body 20 of the composite container 10A. The plastic member 40a may also be cylindrical with no seams around the entire circumference. Examples of such plastic members 40a include the above-mentioned direct blow tube, sheet molding tube, and injection molding tube.

As shown in FIG. 9(b), the plastic member 40a may be generally tubular (bottomless cylindrical) and have a cylindrical body 41. The plastic member 40a may also be cylindrical with no seams along its entire circumference. In this case, the plastic member 40a may be, for example, the above-mentioned blow tube, extrusion tube, inflation molding tube, or sheet molding tube.

Also, as shown in Figures 9(c) and 9(d), the plastic member 40a may be produced by forming a film into a cylindrical shape and bonding the ends together. In this case, as shown in Figure 9(c), the plastic member 40a may be configured in a tubular shape (bottomless cylindrical shape) having a body 41, or as shown in Figure 9(d), it may be configured in a bottomed cylindrical shape by bonding a bottom 42 together.

Manufacturing Method of Composite Container Next, a manufacturing method of the composite container 10A according to this embodiment will be described with reference to FIGS.

First, a preform 10a made of a plastic material is prepared (see FIG. 10(a)). In this case, the preform 10a may be produced by injection molding using, for example, an injection molding machine (not shown). Also, a preform that is generally used in the past may be used as the preform 10a.

Next, a plastic member 40a is provided on the outside of the preform 10a to produce a composite preform 70 having the preform 10a and the plastic member 40a attached to the outside of the preform 10a (see FIG. 10(b)). In this case, the plastic member 40a has a bottomed cylindrical shape as a whole, and has a cylindrical body 41 and a bottom 42 connected to the body 41.

At this time, a plastic member 40a having an inner diameter equal to or slightly smaller than the outer diameter of the preform 10a may be pressed into the preform 10a to adhere to the outer surface of the preform 10a. Alternatively, as described below, a heat-shrinkable plastic member 40a may be provided on the outer surface of the preform 10a, and the plastic member 40a may be heated to 50°C to 100°C to cause heat shrinkage and adhere to the outer surface of the preform 10a.

In this way, by first attaching the plastic member 40a to the outside of the preform 10a and preparing the composite preform 70, it becomes possible to carry out the series of steps for preparing the composite preform 70 (FIG. 10(a)-(b)) and the series of steps for blow molding (FIG. 10(c)-(f)) in separate locations (such as factories).

Next, the composite preform 70 is heated by the heating device 51 (see FIG. 10(c)). At this time, the composite preform 70 is heated evenly in the circumferential direction by the heating device 51 while rotating with the mouth portion 11a facing downward. The heating temperature of the preform 10a and the plastic member 40a in this heating process may be, for example, 90°C to 130°C.

Then, a blow molding die 50 is prepared. Then, the composite preform 70 heated by the heating device 51 is sent to the blow molding die 50 to produce the composite container 10A (see FIG. 10(d)).

The container body 10 and the plastic member 40 provided in close contact with the outside of the container body 10 are produced using this blow molding die 50. In this case, the blow molding die 50 has a die body 52 which is a metal die or a resin die, and the die body 52 is composed of a pair of body dies 50a, 50b and a bottom die 50c which are separated from each other (see FIG. 10(d)). The inner surface of the die body 52 has a shape corresponding to the neck 13, body 20 and bottom 30 of the composite container 10A. In FIG. 10(d), the pair of body dies 50a, 50b are open from each other, and the bottom die 50c is raised upward. In this state, the composite preform 70 is inserted between the pair of body dies 50a, 50b of the die body 52.

Next, as shown in FIG. 10(e), the pair of body dies 50a, 50b are closed after the bottom die 50c is lowered, and a sealed blow molding die 50 is formed by the pair of body dies 50a, 50b and the bottom die 50c of the die body 52. Next, air is forced into the preform 10a, and biaxial stretch blow molding is performed on the composite preform 70.

As a result, the composite preform 70 is shaped into a shape corresponding to the inner surface of the blow molding die 50, and the container body 10 is obtained from the preform 10a in the blow molding die 50. During this time, the body dies 50a and 50b are heated to 30°C to 80°C, and the bottom die 50c is cooled to 5°C to 25°C. At this time, the preform 10a and the plastic member 40a of the composite preform 70 are expanded as a unit in the blow molding die 50. As a result, the preform 10a and the plastic member 40a are shaped into a shape corresponding to the inner surface of the blow molding die 50. Then, a linearly extending protrusion 33 (see FIG. 4) is formed on the bottom 30 of the container body 10.

In this way, the container body 10 and the plastic member 40 that is in close contact with the outside of the container body 10 are obtained.

Then, as shown in FIG. 10(f), the pair of body dies 50a, 50b and the bottom die 50c of the die body 52 are separated from each other, and the container body 10 and the plastic member 40 attached in close contact with the outside of the container body 10 are removed from inside the blow molding die 50.

Next, a cut portion 45 penetrating the plastic member 40 is formed in the plastic member 40 after blow molding. In this case, the cut portion 45 may be formed, for example, by a laser. In this way, by forming the cut portion 45 by a laser in the plastic member 40 in a state in which it is in close contact with the container body 10, it is possible to easily focus the laser light on the plastic member 40. Therefore, the cut portion 45 can be easily formed at a desired position of the composite container 10A, and the productivity of the composite container 10A can be improved. In addition, since the cut portion 45 can be formed to match the shape of the container body 10, the cut portion 45 of a desired shape can be formed without considering, for example, the elongation rate of the plastic member 40a of the composite preform 70.

The laser to be used is not particularly limited. Examples of lasers that can be used include carbon dioxide lasers, He-Ne lasers, Ar lasers, excimer lasers, metal vapor lasers, fiber lasers, YAG lasers including Nd:YAG lasers, and harmonic lasers thereof. Of these, carbon dioxide lasers are preferred because the devices are relatively small and inexpensive. The wavelength of the laser to be used varies depending on the type of laser to be used; for example, for carbon dioxide lasers, it is 9.4 μm and 10.6 μm, and for Nd:YAG lasers, it is 1064 nm. The wavelength is not limited to these values, and it is preferable to change it appropriately depending on the type of resin material contained in the plastic member 40.

At this time, first, an irradiation device (not shown) for irradiating the laser (for example, ML-Z9500 manufactured by Keyence Corporation) is prepared. Next, the plastic member 40 is irradiated with a laser from the irradiation device. As a result, a cut portion 45 is formed in the plastic member 40 at a position corresponding to the protrusion 33 formed on the bottom 30 of the container body 10. In this way, by forming the cut portion 45 at a position corresponding to the bottom 30 of the container body 10, it is possible to prevent the appearance of the composite container 10A from being damaged.

The notch 45 is formed to have a wave shape (see FIG. 5). Furthermore, the notch 45 has a pair of ends 45a, 45b, and is formed to have an arc shape overall. As a result, the notch 45 is formed to follow the protrusion 33 that extends in an annular shape.

At this time, a peeling assist line 47 consisting of a half cut is formed on the plastic member 40 after blow molding. In this case, the peeling assist line 47 may be formed by, for example, a laser. Even in this case, by forming the peeling assist line 47 by a laser on the plastic member 40 in a state of being in close contact with the container body 10, it is possible to easily focus the laser light on the plastic member 40. Therefore, the peeling assist line 47 can be easily formed, and the productivity of the composite container 10A can be improved. In addition, since the peeling assist line 47 can be formed according to the shape of the container body 10, it is possible to form the peeling assist line 47 of a desired shape without considering, for example, the elongation rate of the plastic member 40a of the composite preform 70. The laser to be used is not particularly limited, and the same laser as that for forming the above-mentioned cut portion 45 can be used.

The peeling assist line 47 is formed so as to intersect with the planned breaking line 46 (see FIG. 5). In this case, it is preferable that at least a portion of the peeling assist line 47 is formed at a position where the cut portion 45 overlaps with the fan shape that forms an arc.

In this way, composite container 10A is obtained.

Then, the contents are filled into the composite container 10A through the mouth 11 of the composite container 10A.

When recycling the container body 10, it is necessary to separate and remove the plastic member 40 of the composite container 10A from the container body 10. As described above, the cut portion 45 is formed at a position corresponding to the protrusion 33. In addition, the cut portion 45 has a wave shape. This allows at least a part of the cut portion 45 to be easily formed, for example, near the base line 38a of the protrusion 33. Therefore, as shown in FIG. 11(a), when a user hooks his or her fingernail on the part of the protrusion 33 extending in an annular shape where the cut portion 45 is formed near the base line 38a, the cut portion 45 formed near the base line 38a can be used as a trigger to easily break the plastic member 40. Therefore, the plastic member 40 can be easily peeled off from the bottom 30 of the container body 10.

In this case, as shown in FIG. 11(b), a peeled piece P is formed by the portion of the plastic member 40 that peels off from the bottom 30 of the container body 10. A gap G is also formed between the peeled piece P and the bottom 30. This makes it easier for the user to pick up the peeled piece P. As a result, the plastic member 40 can be easily separated and removed from the container body 10.

When the plastic member 40 is to be separated and removed from the container body 10, the user first pulls the peeling piece P, which causes the plastic member 40 to break at the cut portion 45. At this time, the plastic member 40 breaks along the planned break line 46 (see FIG. 5). As the breakage of the plastic member 40 progresses, the breakage reaches the peeling assist line 47 that intersects with the planned break line 46. Here, the peeling assist line 47 extends outside the cut portion 45, and the breakage of the plastic member 40 progresses in the direction in which the width W of the peeling piece P increases, as shown in FIG. 12(a). This makes it possible to prevent the peeling piece P from tearing off while separating the plastic member 40 from the container body 10. In FIG. 12(a), the peeling assist line 47 before it breaks is shown by a dashed line.

Then, as shown in FIG. 12(b), by further pulling the peeled piece P, the plastic member 40 can be easily separated and removed from the container body 10.

As described above, according to this embodiment, the plastic member 40 has a cut portion 45 penetrating the plastic member 40 at a position corresponding to the protrusion 33, and the cut portion 45 has a wave shape. This allows at least a part of the cut portion 45 to be easily formed near the base line 38a of the protrusion 33 without requiring high processing accuracy. Therefore, when a user hooks his or her fingernail on the part of the protrusion 33 extending in an annular shape where the cut portion 45 is formed near the base line 38a, the cut portion 45 formed near the base line 38a can be used as a trigger to easily break the plastic member 40. As a result, the plastic member 40 can be easily peeled off from the bottom 30 of the container body 10, and the plastic member 40 can be easily separated and removed from the container body 10.

In addition, according to this embodiment, the plastic member 40 can be separated and removed from the container body 10, so the colorless and transparent container body 10 can be recycled in the same way as in the conventional case.

In addition, according to this embodiment, at least a portion of the cut portion 45 straddles the base end line 38a of the protrusion portion 33. This allows at least a portion of the cut portion 45 to be reliably formed at a desired position relative to the protrusion portion 33.

In addition, according to this embodiment, the protrusion 33 is formed on the bottom 30 and extends in a ring shape. In this case, the cut portion 45 is formed at a position corresponding to the bottom 30 of the container body 10. In this way, the cut portion 45 is formed at a position of the plastic member 40 corresponding to the bottom 30 of the container body 10, so that the appearance of the composite container 10A is prevented from being damaged. In addition, the thickness of the bottom 30 is generally greater than the thickness of the body 20. Therefore, by forming the cut portion 45 at a position corresponding to the bottom 30 of the container body 10, as described below, even if the container body 10 is scratched when forming the cut portion 45 by a laser, the defect of the container body 10 being opened can be prevented. As a result, the defect of the contents leaking from the composite container 10A can be effectively prevented.

Furthermore, according to this embodiment, the cutout portion 45 has an overall arc shape. In this case, the cutout portion 45 is formed so as to follow the protrusion portion 33 that extends in an annular shape. Therefore, it is possible to form many portions of the cutout portion 45 that can be positioned at the desired position relative to the protrusion portion 33.

In the above embodiment, after the incision 45 is formed, the plastic member 40 around the incision 45 may be heated to shrink the plastic member 40 around the incision 45. In this case, the plastic member 40 around the incision 45 may be heated using hot air from a heat gun or the like. In addition to hot air from a heat gun or a hair dryer, the heating method may also use steam, a heated tool, or a laser. In the case of steam, it is also possible to use a shrink tunnel when attaching a shrink label. In addition, when heating the plastic member 40 around the incision 45, the surrounding area may be heated to a degree that does not deform the container. In this case, the plastic member 40 around the incision 45 shrinks, so that the plastic member 40 around the incision 45 can be raised relative to the container body 10. This makes it easier to pick up the plastic member 40 around the incision 45, and the plastic member 40 can be easily separated and removed from the container body 10. In addition, when the plastic member 40 around the cut portion 45 is heated to shrink the plastic member 40 around the cut portion 45, a plastic member 40 that has a shrinking effect is used.

In the above embodiment, an example was described in which the incision 45 and the peeling assist line 47 are each formed by a laser. However, this is not limited to this, and the incision 45 and the peeling assist line 47 may each be formed by a Thompson blade or a Vic blade used in cutters and punching dies, a Pinnacle blade made by etching or a blade sharpened by these, or another blade made by cutting (engraving blade).

In the above embodiment, an example has been described in which two peel assist lines 47 are formed on the plastic member 40. However, this is not limited thereto, and as shown in FIG. 13, the number of peel assist lines 47 formed on the plastic member 40 may be one. Also, as shown in FIG. 14, the plastic member 40 may not have any peel assist lines 47 formed thereon. Furthermore, although not shown, the number of peel assist lines 47 formed on the plastic member 40 may be three or more.

In the above embodiment, an example has been described in which the peeling assist line 47 is formed at a position away from the cut portion 45. However, this is not limited to this, and as shown in FIG. 15, the peeling assist line 47 may be directly connected to the cut portion 45. In this case, as shown in FIG. 16, the peeling assist line 47 may extend along the base end line 38a of the protrusion portion 33.

In the above embodiment, an example was described in which the cut portion 45 is formed radially outward from the second inclined surface 35 of the protrusion 33. However, this is not limited to this, and as shown in FIG. 17, the cut portion 45 may be formed so as to overlap the second inclined surface 35, or may be formed radially inward from the first inclined surface 34. In this case, the cut portion 45 may straddle the base line 38b. Even in this case, the plastic member 40 can be easily broken by the cut portion 45 formed near the base line 38b, which is formed by the user's fingernail on the part of the protrusion 33 extending in an annular shape where the cut portion 45 is formed near the base line 38b. Therefore, the plastic member 40 can be easily peeled off from the bottom 30 of the container body 10, and the plastic member 40 can be easily separated and removed from the container body 10. In the illustrated example, the peeling assistance line 47 is formed radially inward from the cut portion 45, but this is not limited to this. For example, although not shown, the peel assist line 47 may be formed radially outward from the cut portion 45. In this case, the planned break line 46 may extend radially outward from each of the pair of ends 45a, 45b of the cut portion 45.

In the above embodiment, an example has been described in which the protrusion 33 is formed on the bottom 30 of the container body 10. However, this is not limited to this, and as shown in Figs. 18 and 19, a linear protrusion 33A may be formed on the neck 13 of the container body 10. This protrusion 33A may extend linearly. Furthermore, the protrusion 33A may be formed around the entire circumference of the neck 13, or may be formed on only a portion of the neck 13 in the circumferential direction.

The protrusion 33A includes a first inclined surface 34A, a second inclined surface 35A located below the first inclined surface 34A, and a connecting surface 36A connecting the first inclined surface 34A and the second inclined surface 35A. The first inclined surface 34A is inclined radially outward as it extends downward, and the second inclined surface 35A is inclined radially inward as it extends downward. On the other hand, the connecting surface 36A is approximately parallel to the central axis of the container body 10 in a vertical cross section.

Such protrusions 33A are formed during blow molding by providing recesses on the inner surfaces of the body dies 50a, 50b of the blow molding die 50. In this case, a recess 37A corresponding to the protrusions 33A is formed on the inner surface of the neck 13 of the container body 10. Note that in Figure 19, the neck 13 when the protrusions 33A are not formed is shown by a two-dot chain line (phantom line).

In this modified example, as shown in Figures 18 and 19, the cutout 45 is formed at a position corresponding to the neck 13 and at a position corresponding to the protrusion 33A. The cutout 45 has a linear shape as a whole. In this specification, "having a linear shape as a whole" means that in the wave shape of the cutout 45, the apexes of the peaks are positioned on approximately the same line, the apexes of the valleys are positioned on approximately the same line, and the lines are approximately parallel to each other.

In the illustrated example, the cutout 45 is formed above the second inclined surface 35A and crosses the base line 38c. In this modified example, the peeling assist line 47 is formed below the cutout 45. Although not shown, the cutout 45 may be formed below the position corresponding to the first inclined surface 34A of the protrusion 33A and cross the base line 38d. In this case, the peeling assist line 47 may be formed above the cutout 45. In this specification, the "base line 38c" refers to a point located above the protrusion 33A in a vertical cross section, and is a line that circumferentially connects points on the outer surface 13a of the neck 13 where the curvature changes (parts that bend in cross section). Additionally, the "base line 38d" refers to a point located below the protrusion 33A in a vertical cross section, and is a line that circumferentially connects points on the outer surface 13a of the neck 13 where the curvature changes (parts that bend in cross section).

According to this modified example, a protrusion 33A that protrudes radially outward is formed on the neck 13, and a cutout 45 is formed at a position corresponding to the protrusion 33A. The cutout 45 also has a wave shape. This allows at least a portion of the cutout 45 to be easily formed near the base line 38c of the protrusion 33A without requiring high processing accuracy. Therefore, the plastic member 40 can be easily peeled off from the bottom 30 of the container body 10, and the plastic member 40 can be easily separated and removed from the container body 10.

In the composite container 10A, the neck 13 of the container body 10 has a smaller diameter than the body 20 of the container body. That is, when the preform 10a and the plastic member 40a are expanded as a unit by blow molding, the neck 13 of the container body 10 is the part that has a smaller circumferential stretch ratio than the body 20 of the container body. As a result, the part of the plastic member 40 that corresponds to the neck 13 of the container body 10 is thicker than the part that corresponds to the body 20 of the container body 10. Therefore, by forming the cut portion 45 at a position of the plastic member 40 that corresponds to the neck 13 of the container body 10, the thick plastic member 40 can be easily broken using the cut portion 45 as a trigger, and the plastic member 40 can be easily separated and removed from the container body 10.

In addition, according to this modified example, the protrusion 33A extends linearly, and the cutout 45 has a linear shape overall. In this case, the cutout 45 is formed so as to follow the protrusion 33A that extends linearly. Therefore, it is possible to form a large portion of the cutout 45 that can be positioned at a desired position relative to the protrusion 33A.

Also, as shown in Figures 20 and 21, a linearly extending protrusion 33B may be formed on the body 20 of the container body 10. In this modification, the protrusion 33B is formed on the second portion 22 of the body 20. This protrusion 33B may extend linearly. Furthermore, the protrusion 33B may be formed around the entire circumference of the body 20, or may be formed on only a portion of the body 20 in the circumferential direction. The protrusion 33B may be formed on the first portion 21 of the body 20.

The protrusion 33B includes a first inclined surface 34B, a second inclined surface 35B located below the first inclined surface 34B, and a connecting surface 36B connecting the first inclined surface 34B and the second inclined surface 35B. The first inclined surface 34B is inclined radially outward as it extends downward, and the second inclined surface 35B is inclined radially inward as it extends downward. On the other hand, the connecting surface 36B is approximately parallel to the central axis of the container body 10 in a vertical cross section.

Such protrusions 33B are formed during blow molding by providing recesses on the inner surfaces of the body dies 50a, 50b of the blow molding die 50. In this case, a recess 37B corresponding to the protrusions 33B is formed on the inner surface of the body 20 of the container body 10. Note that in Figure 21, the body 20 without the protrusions 33B is shown by a two-dot chain line (phantom line).

In this modified example, as shown in Figures 20 and 21, the notch 45 is formed at a position corresponding to the body 20, and is formed at a position corresponding to the protrusion 33B. In this modified example, the notch 45 is formed in the second portion 22 of the body 20. Note that the notch 45 may also be formed in the first portion 21 of the body 20.

In the illustrated example, the cutout 45 is formed above the second inclined surface 35B and crosses the base line 38e. In this modified example, the peeling assist line 47 is formed below the cutout 45. Although not shown, the cutout 45 may be formed below the position corresponding to the first inclined surface 34B of the protrusion 33B and cross the base line 38f. In this case, the peeling assist line 47 may be formed above the cutout 45. In this specification, the "base line 38e" refers to a point located above the protrusion 33B in a vertical cross section, and is a line that circumferentially connects points (parts that bend in cross section) on the outer surface 20b of the body 20 where the curvature changes near the protrusion 33B. Additionally, the "base line 38f" refers to a point located below the protrusion 33B in a vertical cross section, and is a line that circumferentially connects points on the outer surface 20b of the body 20 where the curvature changes near the protrusion 33B (parts that bend in cross section).

According to this modified example, a protrusion 33B that protrudes radially outward is formed on the body 20, and a cutout 45 is formed at a position corresponding to the protrusion 33B. The cutout 45 also has a wave shape. This allows at least a portion of the cutout 45 to be easily formed near the base line 38e of the protrusion 33B without requiring high processing accuracy. Therefore, the plastic member 40 can be easily peeled off from the bottom 30 of the container body 10, and the plastic member 40 can be easily separated and removed from the container body 10.

The multiple components disclosed in the above embodiment and each modified example may be combined as needed. Alternatively, some components may be deleted from all the components shown in the above embodiment and each modified example.

REFERENCE SIGNS LIST 10 Container body 10A Composite container 10a Preform 11 Mouth portion 13 Neck portion 20 Body portion 30 Bottom portion 33, 33A, 33B Projection portion 38a to 38f Base line 40, 40a Plastic member 45 Cut portion

Claims (7)

In composite containers,
a container body having a mouth, a neck, a body and a bottom;
A plastic member provided in close contact with the outer surface of the container body,
a protrusion extending linearly and protruding outward from the container body is formed on at least one of the neck, the body, and the bottom of the container body;
a cut portion penetrating the plastic member is formed at a position of the plastic member corresponding to the protrusion;
The cut portion has a wave shape,
A composite container, wherein the cut portion crosses the base line of the protrusion portion a plurality of times. The composite container according to claim 1, wherein the protrusion is formed on the bottom and extends in an annular shape. The composite container according to claim 2, wherein in the wavy shape of the cuts, the curves smoothly connecting the apexes of the peaks and the curves smoothly connecting the apexes of the valleys are each arc-shaped, and the centers of the respective arc shapes are aligned with each other. The composite container according to claim 1, wherein the protrusion is formed on at least one of the neck and the body, and extends linearly in a front view. 5. The composite container according to claim 4, wherein in the wave shape of the cut portions, apexes of the peaks are aligned on the same line in a front view , and apexes of the valleys are aligned on the same line in a front view , and the respective lines are parallel to each other in a front view . In a method for manufacturing a composite container,
Preparing a preform;
providing a plastic member on the exterior of the preform;
a step of blow molding the preform and the plastic member to expand the preform and the plastic member as a unit, thereby producing a container body corresponding to the preform and a plastic member provided in close contact with the outside of the container body;
and forming a cut portion penetrating the plastic member after the blow molding,
In a process of producing a container body corresponding to the preform and a plastic member provided in close contact with the outside of the container body, a protrusion is formed on at least one of a neck portion, a body portion, and a bottom portion of the container body, the protrusion extending linearly and protruding toward the outside of the container body;
In the step of forming the notch, the notch is formed at a position corresponding to the protrusion,
The cut portion has a wave shape,
A method for manufacturing a composite container, wherein the cut portion crosses the base line of the protrusion portion a plurality of times. The method for manufacturing a composite container according to claim 6, wherein in the step of forming the cut portion, the cut portion is formed by a laser.