JP2018043483A - Composite preform, composite container and method for producing composite preform - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a composite container provided with a plastic member of a collection zone administration capable of covering the bottom of a container body without being damaged even in blow molding, and to be made of plastic at the time of blow molding or the like. Provision of a composite preform that does not generate air bubbles between a member and a container body [Solution] The composite preform of the present invention is connected to a mouth portion, a body portion connected to the mouth portion, and a body portion. A preform having a bottom and a heat-shrinkable plastic member provided so as to surround the outside of the preform, one end of the plastic member on the bottom side of the preform follows the shape of the bottom of the preform. It is characterized in that it is crimped to form a bottom. [Selection diagram] Fig. 1

Description

  The present invention relates to a composite preform, a composite container, and a method for manufacturing a composite preform.

  Recently, plastic bottles for storing content liquids such as foods and drinks have become common, and such plastic bottles store content liquids.

  A plastic bottle containing such a content liquid is manufactured by inserting a preform into a mold and biaxially stretch-blow molding.

  By the way, in the conventional biaxial stretch blow molding method, for example, a preform including a single layer material such as PET or PP, a multilayer material, a blend material, or the like is used to form a container shape. However, in the conventional biaxial stretch blow molding method, the preform is generally simply formed into a container shape. For this reason, when various functions and characteristics (barrier property, heat retaining property, etc.) are given to the container, the means is limited, for example, by changing the material constituting the preform. In particular, it is difficult to have different functions and characteristics depending on the part of the container (for example, the trunk and the bottom).

  In the previous application (Japanese Patent Application Laid-Open No. 2015-128858), the present applicant has proposed a composite container capable of imparting various functions and characteristics to the container.

JP2015-128858A

The composite container disclosed in JP-A-2015-128858 is obtained by blow molding a composite preform including a container body and a plastic member.
The plastic member included in the composite preform is preferably heat-shrinkable from the viewpoint of adhesion to the preform, and thus the container body, but completely covers the bottom of the preform (container body). It was difficult to provide various functions such as improving the light shielding property at the bottom.

  Now, the present inventors can cover the bottom of the preform by thermocompression bonding one end of the plastic member included in the composite preform, and are not damaged by blow molding when manufacturing the composite container. It has been found that a composite preform comprising a heat-shrinkable plastic member can be obtained. Furthermore, by performing this thermocompression bonding along the shape of the bottom of the preform, it is possible to prevent the generation of bubbles, and the adhesion of the plastic member after blow molding to the container body and the appearance thereof are improved. I found out that I can make it. The present invention is based on such knowledge.

  The present invention has been made in view of the above-described background art, and an object of the present invention is to manufacture a composite container including a plastic member that can cover the bottom of a container body without being damaged even in blow molding. It is possible to provide a composite preform that can generate air bubbles between a plastic member and a container body during blow molding.

  The composite preform of the present invention includes a mouth portion, a body portion connected to the mouth portion, a preform having a bottom portion connected to the body portion, and a heat-shrinkable plastic provided so as to surround the outside of the preform. And one end of the plastic member on the bottom side of the preform is pressure-bonded along the shape of the bottom of the preform to form the bottom.

  The composite container of the present invention is a blow-molded product of the above composite preform, and is provided at the mouth, the neck provided below the mouth, the shoulder provided below the neck, and the shoulder below. A heat-shrinkable plastic member provided in close contact with the outside of the container body, and one end of the plastic member on the bottom side of the container body Are crimped to form the bottom.

  The method for producing a composite preform of the present invention includes a step of preparing a preform including a mouth, a body connected to the mouth, and a bottom connected to the body, and a tube-like shape longer than the preform. A step of preparing a heat-shrinkable plastic member, a step of fitting a preform from one end of the plastic member, a step of heating the preform and the plastic member and thermally shrinking the plastic member, And thermocompression bonding the other end of the bottom plastic member along the shape of the bottom of the preform.

  In the said aspect, it is preferable to further include the process cut | disconnected so that the length from the vertex of the bottom part of a preform to the edge part of a plastic member may be 0.5 mm or more and 5 mm or less.

  In the said aspect, it is preferable that the length of a plastic member is 3 mm or more and 25 mm or less longer than the sum of the length of the said preform trunk | drum and bottom part.

According to the present invention, even in blow molding, a composite container including a plastic member that can cover the bottom of the container main body without being damaged can be manufactured. It is possible to provide a composite preform that does not generate bubbles between the container body and this manufacturing method.
Moreover, the composite container which can be manufactured by blow-molding this composite preform can be provided.

FIG. 1 is a partial vertical cross-sectional view of a composite preform of the present invention in one embodiment. FIG. 2 is a partial vertical sectional view showing a composite container manufactured using the composite preform of the present invention in one embodiment. FIG. 3 is a horizontal cross-sectional view of the composite container shown in FIG. 2 taken along line III-III. FIG. 4 is a schematic view showing an embodiment of a method for producing a heat-shrinkable plastic member. FIG. 5 is a vertical sectional view showing a state in which the preform is fitted into a heat-shrinkable plastic member. FIG. 6 is a front view of a heat-shrinkable plastic member. FIG. 7 is a front view of the preform. FIG. 8 is a perspective view showing a crimping instrument according to an embodiment. FIG. 9 is a schematic view showing a method for manufacturing a composite container.

Composite preform 70
The composite preform 70 of the present invention surrounds the outside of the preform 10a, the preform 10a including the mouth portion 11a, the body portion 20a connected to the mouth portion 11a, and the bottom portion 30a connected to the body portion 20a. 1, one end of the plastic member 40a on the bottom side of the preform 10a is crimped along the shape of the bottom portion 11a of the preform 10a, as shown by the oblique lines in FIG. A bottom portion is formed.

  In one embodiment, as shown in FIG. 1, a composite preform 70 includes a preform 10a and a bottomed cylindrical heat-shrinkable plastic member 40a provided outside the preform 10a. The composite container 10A shown in FIG. 2 can be obtained by blow molding.

Preform 10a
As shown in FIG. 1, the preform 10a includes 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 11 a corresponds to the mouth portion 11 of the container body 10 described above, and has substantially the same shape as the mouth portion 11.
Moreover, the trunk | drum 20a respond | corresponds to the neck part 13, the shoulder part 12, and the trunk | drum 20 of the container main body 10 mentioned above, and has a substantially cylindrical shape.
The bottom 30a corresponds to the bottom 30 of the container body 10 described above, and has a substantially hemispherical shape.

The preform 10a can include a resin material such as polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, ionomer resin, or a blend thereof.
In addition, the preform 10a may contain colorants such as red, blue, yellow, green, brown, black, and white. However, in consideration of ease of recycling, the preform 10a does not contain these colorants and is colorless. It is preferably transparent.

Heat-shrinkable plastic member 40a
As shown in FIG. 1, the heat-shrinkable plastic member 40a is provided so as to surround the outside without being bonded to the preform 10a, and is in close contact with the preform 10a so as not to move or rotate. Or it is in close contact so that it does not fall under its own weight.
The heat-shrinkable plastic member 40a is provided over the entire circumferential direction so as to surround the preform 10a. As shown in FIG. 1, the heat-shrinkable plastic member 40a on the bottom 11a side of the preform 10a. One end is thermocompression-bonded along the shape of the bottom portion 11a of the preform 10a to form the bottom portion.
Thus, the composite container 10A in which the bottom 11 of the container body 10 is covered with the plastic member 40 by thermocompression bonding one end of the heat-shrinkable plastic member 40a along the shape of the bottom 11a of the preform 10a. In addition, air bubbles are not generated during blow molding, and the adhesion of the plastic member 40 to the container body 10 can be improved. Moreover, since there are no bubbles, the appearance of the composite container 10A can be improved.

The heat-shrinkable plastic member 40a is made of polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, poly-4-methylpentene, polystyrene, AS resin, ABS tree, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol. , Polyvinyl acetal, polyvinyl butyral, ionomer resin, diallyl phthalate resin, fluororesin, polymethyl methacrylate, polyacrylic acid, polymethyl acrylate, polyacrylonitrile, polyacrylamide, polybutadiene, polybutene, polyisoprene, polychloroprene, ethylene Propylene rubber, butyl rubber, nitrile rubber, acrylic rubber, silicone rubber, fluoro rubber, nylon 6, nylon 6,6, MXD6, aromatic polyamide Polycarbonate, poly (ethylene terephthalate), poly (butyl terephthalate), poly (ethylene naphthalate), U polymer, liquid crystal polymer, modified polyphenylene ether, polyether ketone, polyether ether ketone, unsaturated polyester, alkyd resin, polyimide, polysulfone, polyphenylene sulfide, Resin materials such as polyethersulfone, silicone resin, polyurethane, phenol resin, urea resin, polyethylene oxide, polypropylene oxide, polyacetal, epoxy resin, and ionomer resin can be included.
Among these, polyethylene, polypropylene, and polystyrene are preferable because breakage can be further prevented from a thermocompression-bonded portion or the like during blow molding in manufacturing the composite container 10A.
The resin material may include a copolymer obtained by polymerizing two or more monomer units constituting the above-described resin. Furthermore, the resin material may comprise two or more of the above-described resins.

The heat-shrinkable plastic member 40a may include a material having a gas barrier property such as an oxygen barrier property or a water vapor barrier property.
In this case, without using a multi-layer preform or a preform containing a blend material as the preform 10a, the gas barrier property of the composite container 10A is improved, oxygen is prevented from entering the container, and the content liquid is prevented from deteriorating. In addition, it is possible to prevent the evaporation of water vapor from the inside of the container to the outside and to prevent the internal volume from decreasing.
As such a material, polyethylene, polypropylene, MXD-6, PGA, EVOH, polyethylene naphthalate or an oxygen absorbing material such as a fatty acid salt may be mixed with these materials.
When the heat-shrinkable plastic member 40a is composed of multiple layers, a layer made of a material having gas barrier properties may be provided.

The heat-shrinkable plastic member 40a may contain a material having a light barrier property such as ultraviolet rays.
In this case, the light barrier property of the composite container 10A can be improved and the content liquid can be prevented from being deteriorated by ultraviolet rays or the like without using a multilayer preform or a preform containing a blend material as the preform 10a.
As such a material, a resin material containing two or more kinds of the above-described resins, or a material obtained by adding a light-shielding resin to polyethylene terephthalate, polyethylene, or polypropylene can be considered. Moreover, you may use the foaming member with the foam cell diameter of 0.5-100 micrometers produced by mixing inert gas (nitrogen gas, argon gas) with the melt of a thermoplastic resin.
When the heat-shrinkable plastic member 40a is composed of multiple layers, a layer made of a material having a light barrier property may be provided.

Further, the heat-shrinkable plastic member 40a may include a material having a higher heat retaining property or a higher heat retaining property than the plastic material forming the preform 10a (a material having a low heat conductivity).
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. Thereby, the heat retaining property or cold retaining property of the composite container 10A is enhanced.
Examples of such materials include foamed polyurethane, polystyrene, polyethylene, polypropylene, phenol resin, polyvinyl chloride, urea resin, silicone, polyimide, melamine resin, and the like.
In the case where the heat-shrinkable plastic member 40a is composed of multiple layers, it may be provided with a layer made of a material having high heat retention or cold retention (material having low thermal conductivity).
Moreover, it is preferable to mix a hollow particle with the resin material containing these resins. The average particle diameter of the hollow particles is preferably 1 to 200 μm, and more preferably 5 to 80 μm. The hollow particles may be organic hollow particles composed of a resin or the like, or may be inorganic hollow particles composed of glass or the like. Hollow particles are preferred. Examples of the resin constituting the organic hollow particles include styrene resins such as cross-linked styrene-acrylic resins, (meth) acrylic resins such as acrylonitrile-acrylic resins, phenolic resins, fluorine resins, polyamide resins, and polyimides. Resin, polycarbonate resin, polyether resin and the like. Also, Ropeke HP-1055, Ropeke HP-91, Ropeke OP-84J, Ropeke Ultra, Ropeke SE, Ropeke ST (manufactured by Rohm and Haas), Nipol MH-5055 (manufactured by Nippon Zeon), SX8782 Commercially available hollow particles such as SX866 (manufactured by JSR Corporation) can also be used.
As content of a hollow particle, when the heat-shrinkable plastic member 40a consists of a single layer, it is 0.01-50 mass parts with respect to 100 mass parts of resin materials contained in the heat-shrinkable plastic member 40a. It is preferable that it is 1 to 20 parts by mass. When the heat-shrinkable plastic member 40a is composed of multiple layers, the heat-shrinkable plastic member 40a is 0.01 to 50 parts by mass with respect to 100 parts by mass of the resin material contained in the layer of the heat-shrinkable plastic member 40a containing the hollow particles. It is preferable that it is 1 to 20 parts by mass.

The heat-shrinkable plastic member 40a may include a material that is less slippery than the plastic material that forms the preform 10a.
In this case, the user can easily hold the composite container 10A without changing the material of the container body 10. Note that when the heat-shrinkable plastic member 40a is composed of multiple layers, the preform 10a is configured. You may provide the layer which consists of material which is harder to slip than a plastic material. In this case, the layer is preferably the outermost layer of the heat-shrinkable plastic member 40a.

Manufacturing method of composite preform 70 The manufacturing method of the composite preform 70 according to the present invention includes:
Preparing a preform 10a including a mouth portion 11a, a trunk portion 20a coupled to the mouth portion 11a, and a bottom portion 30a coupled to the trunk portion 20a;
Preparing a tube-shaped heat-shrinkable plastic member 40a longer than the preform 10a;
A step of fitting the preform 10a from one end of the plastic member 40a;
Heating the preform 10a and the plastic member 40a to thermally shrink the plastic member 40a;
And thermocompression bonding the other end of the plastic member 40a on the bottom 11a side of the preform 10a along the shape of the bottom 11a of the preform 10a.

Process for Preparing Preform The preform 10a can be manufactured by injection-molding the above-described resin material such as polyethylene using a conventionally known apparatus.

Moreover, the container main body 10 can be made into the multilayer molding bottle of 2 layers or more by producing the multilayer preform 10a of 2 layers or more by injection molding.
For example, after forming a preform 10a consisting of three or more layers, the intermediate layer is a layer containing a gas barrier property and light shielding resin (intermediate layer) such as MXD6, MXD6 + fatty acid salt, PGA, EVOH or polyethylene naphthalate A multilayer molded bottle having gas barrier properties and light shielding properties can be obtained by blow molding. As the intermediate layer, a resin blended with the various resins described above may be used.

  Further, by mixing an inert gas (nitrogen gas, argon gas) with the thermoplastic resin melt, a foam preform having a foam cell diameter of 0.5 to 100 μm is formed, and this foam preform is blow-molded. Thus, the container body 10 may be manufactured. Since such a container main body 10 contains the foam cell, the light shielding property of the container main body 10 whole can be improved.

Process for Preparing Tube-shaped Heat-Shrinkable Plastic Member 40a In one embodiment, the tube-shaped heat-shrinkable plastic member 40a can be produced by a method including an extrusion process.
More specifically, first, the above-described resin material or the like is heated and melted in an extrusion apparatus, and the molten resin material or the like is continuously extruded from a ring die and cooled to be formed into an unstretched extruded tube 1. (See FIG. 4 (a)). The multilayer plastic member 40a can be manufactured by co-extruding two or more resin materials.
Next, one end of the extruded tube is closed by welding or bonding one end of the unstretched extruded tube.
Further, the extruded tube 1 whose one end is closed is disposed in a mold 2 having an inner diameter larger than the outer diameter of the extruded tube 1 (see FIG. 4B).
Next, the blow device 3 is disposed (attached) to the other end of the extruded tube 1 (see FIG. 4C). At this time, it is preferable that the blower 3 is in close contact with the extruded tube 1 so that air does not leak between them.
Subsequently, the extruded tube 1, the mold 2 and the blow device 3 are sent to the heating furnace 4 in this arrangement, and heated to 70 to 150 ° C. inside the heating furnace 4 (see FIG. 4D). As the heating furnace 4, a hot-air circulating heating furnace may be used in order to make the inside uniform. Or you may heat these by passing the extrusion tube 1, the metal mold | die 2, and the blow apparatus 3 in the heated liquid.
Next, the extruded tube 1, the mold 2 and the blow device 3 are taken out from the heating furnace 4, and air is blown into the extruded tube 1 from the blow device 3, whereby the inner surface of the extruded tube 1 is stretched under pressure. As a result, the extruded tube 1 expands and expands along the inner shape of the mold 2 (see FIG. 4E).
Thereafter, the extruded tube 1 is cooled in cold water while air is blown out from the blower 3, and the extruded tube is taken out from the mold 2 (see FIG. 4 (f)). By cutting this into a desired size, a tubular heat-shrinkable plastic member 40a is obtained (see FIG. 4G).
A commercially available tube-shaped heat-shrinkable plastic member 40a may be used.

As shown in FIG. 5, the length of the heat-shrinkable plastic member 40a is longer than the sum of the lengths of the body portion 20a and the bottom portion 30aA of the preform 10a, and preferably 3 mm or longer than the preform 10a. More preferably, the length is 5 mm or more and 20 mm or less. By setting it as such a numerical value range, while being able to perform a thermocompression bonding process more easily, the material to be used can be reduced and cost reduction can be aimed at.
In the present invention, the length of the heat-shrinkable plastic member 40a refers to the length X before heat shrinkage, as shown in FIG. Further, the sum of the lengths of the body portion 20a and the bottom portion 30a of the preform 10a refers to the length Y shown in FIG.

Further, the heat shrinkable plastic member 40a may be designed or printed. In this case, it is possible to display images and characters on the composite container 10A without separately providing a label or the like to the container body 10 after blow molding.
Printing can be performed by a printing method such as an inkjet method, a gravure printing method, an offset printing method, or a flexographic printing method. For example, when the inkjet method is used, a print layer can be formed by applying UV curable ink to the heat-shrinkable plastic member 40a (40), irradiating it with UV, and curing it.
This printing may be performed on the heat-shrinkable plastic member 40a before being fitted into the preform 10a, or may be performed in a state where the heat-shrinkable plastic member 40a is provided outside the preform 10a. good. Further, the heat-shrinkable plastic member 40 of the composite container 10A after blow molding may be printed.

Inserting Step As shown in FIG. 5, the method of the present invention includes a step of inserting the preform 10a from one end of the heat-shrinkable plastic member 40a.

Heat Shrink Process The method of the present invention includes a process of heating the preform 10a and the heat shrinkable plastic member 40a to heat shrink the heat shrinkable plastic member 40a.

  The heating method of the preform 10a and the heat-shrinkable plastic member 40a is not particularly limited, and can be appropriately performed using infrared rays, hot air, or the like. The heating temperature is preferably 60 ° C. or higher and 250 ° C. or lower, and more preferably 80 ° C. or higher and 150 ° C. or lower. The heating temperature is the surface temperature of the heat-shrinkable plastic member 40a at the time of heating, not the irradiation temperature of infrared rays or warm air.

Thermocompression bonding process The thermocompression bonding of the plastic member 40a opposite to the end where the preform 10a is fitted (the other end) is shown in FIG. 8 after the crimping part is heated by infrared rays or warm air. This can be done by sandwiching between a pair of crimping instruments 90A and 90B. The material of this crimping | compression-bonding instrument is not specifically limited, The thing made from a metal or a heat resistant resin can be used.
According to the crimping tool as shown in FIG. 8, the end of the plastic member 40a can be thermocompression bonded along the bottom 30a of the preform 10a.
The shape of the crimping device is not particularly limited as long as the plastic member 40a can be thermocompression bonded along the bottom 30a of the preform 10a.
The surface of the crimping device may be flat or partially or entirely uneven.
Moreover, the crimping | compression-bonding instrument may have a heating mechanism in the surface. Thereby, the crimping strength can be further increased. The heating temperature of the surface of the crimping device is preferably, for example, 100 ° C. or more and 250 ° C. or less.

The pressure during pressure bonding is preferably 50 N / cm ² or more and 1000 N / cm ² or less, more preferably 100 N / cm ² or more and 500 N / cm ² or less.

  The temperature of the heat-shrinkable plastic member 40a at the time of pressure bonding is preferably 80 ° C. or higher and 200 ° C. or lower, although it depends on the material.

Further, the end of the plastic member 40a after thermocompression bonding may be cut to an appropriate length if desired. Thereby, the external appearance of the bottom part at the time of setting it as a composite container becomes favorable.
Specifically, it is preferable to cut the length Z from the apex of the bottom 30a of the preform 10a to the end of the pressure-bonded plastic member 40a to be 0.5 mm or more and 5 mm or less.
As shown in FIG. 1, the crimping portion may be cut in a straight line or in a shape along the shape of the bottom of the preform 10a (not shown).

The heat-shrinkable plastic member 40a after heat shrinkage is not adhered to the outer surface of the preform 10a and is in close contact with the preform 10a so that it does not move or rotate, or does not fall by its own weight. It is in close contact.
As shown in FIG. 1, the plastic member 40 a has a bottomed cylindrical shape, and includes a cylindrical body 41 and a bottom 42 connected to the body 41. In this case, since the bottom 42 of the plastic member 40a covers the bottom 30a of the preform 10a, various functions and characteristics can be imparted to the bottom 30 in addition to the trunk 20 of the composite container 10A.

Composite container 10A
A composite container 10A is a blow-molded product of the composite preform 70, and as shown in FIG. 2, a container main body 10 located on the inner side, and a plastic member 40 provided in close contact with the outer side of the container main body 10 It has.

Container body 10
Among these, the container body 10 includes a mouth portion 11, a neck portion 13 provided below the mouth portion 11, a shoulder portion 12 provided below the neck portion 13, a trunk portion 20 provided below the shoulder portion 12, And a bottom portion 30 provided below the portion 20. In the present specification, “upper” and “lower” refer to the upper side and the lower side in a state where the composite container 10A is erected (FIG. 2), respectively.

  The mouth portion 11 has a screw portion 14 screwed to a cap (not shown) and a flange portion 17 provided below the screw portion 14. The shape of the mouth portion 11 may be a conventionally known shape, or may be a mouthpiece type mouth portion.

  The neck portion 13 is located between the flange portion 17 and the shoulder portion 12 and has a substantially cylindrical shape having a substantially uniform diameter. The shoulder 12 is located between the neck 13 and the trunk 20 and has a shape whose diameter gradually increases from the neck 13 toward the trunk 20.

  Furthermore, the trunk | drum 20 has a cylindrical shape with a substantially uniform diameter as a whole. However, the present invention is not limited to this, and the body portion 20 may have a polygonal cylindrical shape such as a rectangular cylindrical shape or an octagonal cylindrical shape. Or the trunk | drum 20 may have a cylinder shape with a horizontal cross section which is not uniform toward upper direction from the downward direction. Moreover, in this Embodiment, although the unevenness | corrugation is not formed in the trunk | drum 20, and has a substantially flat surface, it is not restricted to this. For example, unevenness such as a panel or a groove may be formed on the body portion 20.

  The bottom portion 30 has a concave portion 31 located in the center and a grounding portion 32 provided around the concave portion 31. 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 round bottom shape).

  Moreover, although the thickness of the container main body 10 in the trunk | drum 20 is not limited to this, For example, it can be made thin to about 50 micrometers-250 micrometers. Further, the weight of the container body 10 is not limited to this, but for example, when the internal volume of the container body 10 is 500 ml, the weight can be 10 g to 20 g. Thus, by reducing the thickness of the container main body 10, the weight of the container main body 10 can be reduced.

  The container main body 10 can be manufactured by biaxially stretch blow molding a preform 10a manufactured by injection molding of a resin material.

  In order to enhance the barrier property of the container, 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.

  The container main body 10 may consist of a bottle with a full capacity of 100 mL to 2000 mL, for example. Alternatively, the container main body 10 may be a large bottle having a full capacity of, for example, 10L to 60L.

Heat-shrinkable plastic member 40
The heat-shrinkable plastic member 40 is in close contact with the outer surface of the container main body 10 in a thinly extended state, and is attached to the container main body 10 without being easily moved or rotated.
As shown in FIG. 3, the heat-shrinkable plastic member 40 is provided over the entire circumferential direction so as to surround the container body 10 and has a substantially circular horizontal cross section. One end on the bottom 30 side is pressure-bonded to form the bottom.

  The plastic member 40 can be obtained by biaxial stretch blow molding after a plastic member 40a provided so as to surround the outside of the preform 10a is brought into close contact with the outside of the preform 10a.

  As shown in FIG. 2, the plastic member 40 can be provided so as to cover the shoulder portion 12, the trunk portion 20, and the bottom portion 30 of the container body 10 except for the mouth portion 11 and the neck portion 13. With such a configuration, desired functions and characteristics can be imparted to the shoulder portion 12, the trunk portion 20, and the bottom portion 30 of the container body 10.

  Further, the thickness of the heat-shrinkable plastic member 40 is not limited to this, but can be set to, for example, about 5 μm to 50 μm in a state of being attached to the container body 10.

Further, since the heat-shrinkable plastic member 40 is not welded or bonded to the container body 10, it can be separated (separated) from the container body 10 and removed.
As a method of separating (peeling) the heat-shrinkable plastic member 40 from the container body 10, for example, the heat-shrinkable plastic member 40 is cut using a blade or the like, or cut into the heat-shrinkable plastic member 40 in advance. A line may be provided, and the heat-shrinkable plastic member 40 may be peeled along the cutting line. Since the heat-shrinkable plastic member 40 can be separated and removed from the container body 10 by the method as described above, the colorless and transparent container body 10 can be recycled as in the conventional case.

Manufacturing method of composite container The manufacturing method of the composite container according to the present invention is:
Heating and inserting the composite preform 70 of the present invention into a blow mold;
And a step of expanding the preform 10a and the heat-shrinkable plastic member 40a integrally by performing blow molding on the composite preform 70 after heating.

  9A to 9D, the method for manufacturing the composite container 10A of the present invention will be described in more detail.

  First, the composite preform 70 is heated by the heating device 51 (see FIG. 9A). At this time, the composite preform 70 is evenly heated 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 step may be, for example, 90 ° C. to 130 ° C.

  Subsequently, the composite preform 70 heated by the heating device 51 is sent to the blow molding die 50 (see FIG. 9B).

  The composite container 10 </ b> A is molded using this blow molding die 50. In this case, the blow mold 50 includes a pair of body molds 50a and 50b and a bottom mold 50c that are divided from each other (see FIG. 9B). In FIG. 9B, the pair of body molds 50a and 50b are open to each other, and the bottom mold 50c is raised upward. In this state, the composite preform 70 is inserted between the pair of body molds 50a and 50b.

  Next, as shown in FIG. 9C, after the bottom mold 50c is lowered, the pair of body molds 50a and 50b are closed, and the pair of body molds 50a and 50b and the bottom mold 50c are used. A sealed blow molding die 50 is configured. Next, air is press-fitted into the preform 10 a and biaxial stretch blow molding is performed on the composite preform 70.

  As a result, the container body 10 is obtained from the preform 10 a in the blow molding die 50. During this time, the body molds 50a and 50b are heated to 30 ° C. to 80 ° C., and the bottom mold 50c is cooled to 5 ° C. to 25 ° C. At this time, in the blow mold 50, the preform 10a of the composite preform 70 and the plastic member 40a are expanded as a unit. Thereby, the preform 10a and the plastic member 40a are integrally formed into a shape corresponding to the inner surface of the blow mold 50.

  In this manner, a composite container 10A including the container body 10 and the plastic member 40 provided on the outer surface of the container body 10 is obtained.

  Next, as shown in FIG. 9 (d), the pair of body molds 50 a and 50 b and the bottom mold 50 c are separated from each other, and the composite container 10 </ b> A is taken out from the blow molding mold 50.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

(Step of preparing the preform 10a)
A PET preform 10a shown in FIG. 7 was produced using an injection molding machine. The weight of the preform 10a was 23.8 g, and the sum Y of the lengths of the body portion 20a and the bottom portion 30a was 90 mm.

(Process for preparing the heat-shrinkable plastic member 40a)
The polyolefin resin was melted and extruded from a ring die. Next, the extruded tube inner surface was pressurized, or the tube outer surface was subjected to negative pressure from the inner surface to expand the diameter, thereby producing a heat-shrinkable plastic member 40a.
The length X of the produced heat-shrinkable plastic member 40a was 100 mm.

(Fitting process)
Next, the preform 10a was fitted from one end of the heat-shrinkable plastic member 40a by manual work.

(Heat shrinkage and thermocompression process)
After the fitting, the preform 10a and the heat-shrinkable plastic member 40a were heated to 100 ° C. by using an infrared heater to heat-shrink the heat-shrinkable plastic member 40a.
Next, by using a pair of crimping tools 90A and 90B shown in FIG. 8 heated to 100 ° C., one end of the plastic member 40a is sandwiched at a pressure of 300 N / cm ² , thereby following the shape of the bottom portion 11a of the preform 10a. The composite preform 70 was obtained by thermocompression bonding.

(Manufacture of composite container 10A)
The composite preform 70 obtained as described above was heated to 100 ° C. using an infrared heater and conveyed to a blow molding die shown in FIG. 9B. In this blow molding die, the composite preform 70 was blow-molded to obtain a composite container 10A having a full injection capacity of 500 mL. The plastic member 40 included in the composite container 10A covers the bottom of the container body 10, and the crimping part is not peeled off or damaged, and the presence of air bubbles cannot be confirmed.

Claims (5)

A preform comprising a mouth, a body connected to the mouth, and a bottom connected to the body;
A heat shrinkable plastic member provided so as to surround the outside of the preform,
One end of the plastic member on the bottom side of the preform is pressure-bonded along the shape of the bottom of the preform to form a bottom. A composite container which is a blow molded product of the composite preform according to claim 1,
A mouth part, a neck part provided below the mouth part, a shoulder part provided below the neck part, a trunk part provided below the shoulder part, and a bottom part provided below the trunk part, A container body comprising:
A heat-shrinkable plastic member provided in close contact with the outside of the container body,
One end of the plastic member on the bottom side of the container body is crimped to form a bottom part. Preparing a preform comprising a mouth, a body connected to the mouth, and a bottom connected to the body;
Preparing a tubular heat-shrinkable plastic member longer than the preform;
Inserting the preform from one end of the plastic member;
Heating the preform and the plastic member and thermally shrinking the plastic member;
And a step of thermocompression bonding the other end of the plastic member on the bottom side of the preform along the shape of the bottom of the preform.   The method according to claim 3, further comprising a step of cutting so that a length from an apex of the bottom of the preform to an end of the plastic member is 0.5 mm or more and 5 mm or less.   The method according to claim 3 or 4, wherein the length of the plastic member is 3 mm or more and 25 mm or less longer than the sum of the length of the body and the bottom of the preform.