JP2021045973A - Composite preform, composite container and method for producing composite preform - Google Patents

Abstract

To provide a composite preform which can produce a composite container having a plastic-made member capable of covering the bottom part of a container body without causing damage even in blow molding and generates no bubbles between the plastic-made member and the container body during blow molding or the like.SOLUTION: There is provided a composite preform which comprises a mouth part, a body part connected to the mouth part, a preform having a bottom part connected to the body part and a heat shrinkable plastic-made member which is provided so as to surround the outside of the preform, wherein one end of the plastic-made member at the bottom part side of the preform is crimped along the shape of the bottom part of the preform to form a bottom part.SELECTED DRAWING: Figure 1

Description

The present invention relates to composite preforms, composite containers and methods for producing composite preforms.

Recently, plastic bottles have become common as bottles for containing the contents of foods and drinks, and such plastic bottles contain the contents.

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

By the way, in the conventional biaxial stretching blow molding method, a container shape is formed by using a preform containing, for example, a single layer material such as PET or PP, a multilayer material or a blend material. However, in the conventional biaxial stretching blow molding method, it is general that the preform is simply molded into a container shape. Therefore, when the container is to have various functions and properties (barrier property, heat retention property, etc.), the means thereof is limited, for example, changing the material constituting the preform. In particular, it is difficult to give different functions and characteristics depending on the part of the container (for example, the body and the bottom).

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

Japanese Unexamined Patent Publication No. 2015-128858

The composite container disclosed in Japanese Patent Application Laid-Open No. 2015-128858 is obtained by blow molding a composite preform including a container body and a plastic member.
The plastic member included in this composite preform is preferably heat-shrinkable from the viewpoint of adhesion to the preform and the container body, but completely covers the bottom of the preform (container body). It was difficult to add various functions such as improving the light blocking effect of 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 the composite container is not damaged by blow molding during manufacturing. It has been found that a composite preform having a thermocompression-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 air bubbles, and improve the adhesion of the plastic member after blow molding to the container body and its appearance. I found that I could make it. The present invention is based on such findings.

The present invention has been made in view of the above background art, and an object of the present invention is to manufacture a composite container provided with a plastic member capable of covering the bottom of the container body without being damaged even in blow molding. It is an object of the present invention to provide a composite preform that can be formed and does not generate air bubbles between the plastic member and the container body at the time of blow molding or the like.

The composite preform of the present invention includes a mouth part, a body part connected to the mouth part, a preform having a bottom part connected to the body part, and a heat-shrinkable plastic provided so as to surround the outside of the preform. It is characterized in that one end of the plastic member on the bottom side of the preform is crimped 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 composite preform, and is provided with a mouth portion, a neck portion provided below the mouth portion, a shoulder portion provided below the neck portion, and a shoulder portion below the shoulder portion. It is provided with a body portion and a bottom portion provided below the body portion, and is provided with 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. Is crimped to form a bottom.

The method for producing a composite preform of the present invention includes a step of preparing a preform having a mouth portion, a body portion connected to the mouth portion, and a bottom portion connected to the body portion, and a tubular 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 to heat-shrink the plastic member, and a step of heat-shrinking the preform. It is characterized by including a step of heat-bonding the other end of the plastic member on the bottom side along the shape of the bottom of the preform.

In the above aspect, it is preferable to further include a step of cutting so that the length from the apex of the bottom of the preform to the end of the plastic member is 0.5 mm or more and 5 mm or less.

In the above aspect, it is preferable that the length of the plastic member is 3 mm or more and 25 mm or less longer than the sum of the lengths of the preform body and the bottom.

According to the present invention, it is possible to manufacture a composite container provided with a plastic member capable of covering the bottom of the container body without being damaged even in blow molding, and the plastic member can be manufactured during blow molding or the like. It is possible to provide a composite preform in which no air bubbles are generated between the container body and the container body, and a method for producing the same.
Further, it is possible to provide a composite container that can be manufactured by blow molding this composite preform.

FIG. 1 is a partial vertical sectional view of the composite preform of the present invention in one embodiment. FIG. 2 is a partial vertical sectional view showing a composite container manufactured by using the composite preform of the present invention in one embodiment. FIG. 3 is a horizontal sectional view taken along line III-III of the composite container shown in FIG. FIG. 4 is a schematic view showing an embodiment of a method for manufacturing a heat-shrinkable plastic member. FIG. 5 is a vertical cross-sectional view showing a state in which the preform is fitted into a heat-shrinkable plastic member. FIG. 6 is a front view of the heat-shrinkable plastic member. FIG. 7 is a front view of the preform. FIG. 8 is a perspective view showing a crimping tool 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 mouth portion 11a, the body portion 20a connected to the mouth portion 11a, the preform 10a having the bottom portion 30a connected to the body portion 20a, and the outside of the preform 10a. As shown by the diagonal line in FIG. 1, one end of the plastic member 40a on the bottom side of the preform 10a is crimped along the shape of the bottom 11a of the preform 10a. It is characterized by forming a bottom.

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

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 11a corresponds to the mouth portion 11 of the container body 10 described above, and has substantially the same shape as the mouth portion 11.
Further, the body portion 20a corresponds to the neck portion 13, the shoulder portion 12 and the body portion 20 of the container body 10 described above, and has a substantially cylindrical shape.
The bottom portion 30a corresponds to the bottom portion 30 of the container body 10 described above, and has a substantially hemispherical shape.

The preform 10a can contain a resin material such as polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, ionomer resin, or a blend thereof.
Further, the preform 10a may contain colorants such as red, blue, yellow, green, brown, black, and white, but when consideration is given to 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 of the preform 10a without being adhered to the preform 10a, and is in close contact with the preform 10a so as not to move or rotate. Or they are in close contact with each other to the extent that they do not fall under their own weight.
Further, the heat-shrinkable plastic member 40a is provided over the entire circumferential direction so as to surround the preform 10a, and as shown in FIG. 1, the heat-shrinkable plastic member 40a on the bottom 11a side of the preform 10a. One end of the preform 10a is thermocompression bonded along the shape of the bottom portion 11a of the preform 10a to form the bottom portion.
In this way, by thermocompression bonding one end of the heat-shrinkable plastic member 40a along the shape of the bottom portion 11a of the preform 10a, the bottom portion 11 of the container body 10 is covered with the plastic member 40. In addition, bubbles are not generated during blow molding, and the adhesion of the plastic member 40 to the container body 10 can be improved. Further, since there are no air bubbles, the appearance of the composite container 10A can be improved.

The heat-shrinkable plastic member 40a includes polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, poly-4-methylpentene, polystyrene, AS resin, ABS tree, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, and polyvinyl alcohol. , Polyvinyl acetal, Polyvinyl butyral, Ionomer resin, Dialyl phthalate resin, Fluorine resin, Polymethyl methacrylate, Polyacrylic acid, Methyl polyacrylic acid, Polyacrylonitrile, Polyacrylamide, Polybutadiene, Polybutene, Polyisoprene, Polychloroprene, Ethylene Propylene rubber, butyl rubber, nitrile rubber, acrylic rubber, silicone rubber, fluororubber, nylon 6, nylon 6,6, MXD6, aromatic polyamide, polycarbonate, ethylene polyterephthalate, butylene polyterephthalate, 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, phenol resin, urea resin, polyethylene oxide, polypropylene It can contain resin materials such as oxides, polyacetals, epoxy resins, ionomer resins.
Among these, polyethylene, polypropylene and polystyrene are preferable because damage can be further prevented from the thermocompression-bonded portion and the like during blow molding in the production of the composite container 10A.
Further, the resin material may contain a copolymer in which two or more monomer units constituting the above resin are polymerized. Further, the resin material may contain two or more of the above-mentioned resins.

Further, the heat-shrinkable plastic member 40a may contain 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 blended material as the preform 10a, the gas barrier property of the composite container 10A is enhanced, oxygen intrusion into the container is prevented, 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 prevent the content from being reduced.
As such a material, polyethylene, polypropylene, MXD-6, PGA, EVOH, polyethylene naphthalate, or an oxygen absorber such as a fatty acid salt may be mixed with these materials.
When the heat-shrinkable plastic member 40a is composed of multiple layers, it may be provided with a layer made of a material having a gas barrier property.

Further, the heat-shrinkable plastic member 40a may contain a material having a light barrier property such as ultraviolet rays.
In this case, it is possible to enhance the light barrier property of the composite container 10A and prevent the content liquid 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-mentioned resins, or a material obtained by adding a light-shielding resin to polyethylene terephthalate, polyethylene, or polypropylene can be considered. Further, a foaming member having a foam cell diameter of 0.5 to 100 μm, which is produced by mixing an inert gas (nitrogen gas, argon gas) with the melt of the thermoplastic resin, may be used.
When the heat-shrinkable plastic member 40a is composed of multiple layers, it may be provided with a layer made of a material having a light ray barrier property.

Further, the heat-shrinkable plastic member 40a may contain a material having a higher heat-retaining property or a cold-retaining property (a material having a lower thermal conductivity) than the plastic material constituting the 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. As a result, the heat retention or cold retention of the composite container 10A is enhanced.
As such a material, foamed polyurethane, polystyrene, polyethylene, polypropylene, phenol resin, polyvinyl chloride, urea resin, silicone, polyimide, melamine resin and the like can be considered.
When 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-retaining property or cold-retaining property (material having low thermal conductivity).
Further, it is preferable to mix hollow particles with the resin material containing these resins. The average particle size of the hollow particles is preferably 1 to 200 μm, more preferably 5 to 80 μm. Further, 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, but are organic because of their excellent dispersibility. Hollow particles are preferred. Examples of the resin constituting the organic hollow particles include a styrene resin such as a crosslinked styrene-acrylic resin, a (meth) acrylic resin such as acrylonitrile-acrylic resin, a phenol resin, a fluorine resin, a polyamide resin, and a polyimide. Examples thereof include based resins, polycarbonate resins, and polyether resins. In addition, Low Pay HP-1055, Low Pay HP-91, Low Pay OP-84J, Low Pay Ultra, Low Pay SE, Low Pay ST (manufactured by Roam and Hearth Co., Ltd.), Nipole MH-5055 (manufactured by Nippon Zeon Co., Ltd.), SX8782 , SX866 (manufactured by JSR Corporation) and other commercially available hollow particles can also be used.
When the heat-shrinkable plastic member 40a is composed of a single layer, the content of the hollow particles is 0.01 to 50 parts by mass with respect to 100 parts by mass of the resin material contained in the heat-shrinkable plastic member 40a. It is preferably 1 to 20 parts by mass, and more preferably 1 to 20 parts by mass. When the heat-shrinkable plastic member 40a is composed of multiple layers, the amount 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 hollow particles. It is preferably 1 to 20 parts by mass, and more preferably 1 to 20 parts by mass.

Further, the heat-shrinkable plastic member 40a may contain a material that is less slippery than the plastic material constituting the preform 10a.
In this case, the user can easily grip the composite container 10A without changing the material of the container body 10. If the heat-shrinkable plastic member 40a is composed of multiple layers, the preform 10a is formed. It may have a layer made of a material that is less slippery than a plastic material. In this case, the layer is preferably the outermost layer of the heat-shrinkable plastic member 40a.

Method for manufacturing composite preform 70 The method for manufacturing composite preform 70 according to the present invention is as follows.
A step of preparing a preform 10a having 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.
The process of preparing a tubular heat-shrinkable plastic member 40a longer than the preform 10a, and
The process of fitting the preform 10a from one end of the plastic member 40a,
A step of heating the preform 10a and the plastic member 40a to heat-shrink the plastic member 40a, and
The step includes a step of thermocompression bonding the other end of the plastic member 40a on the bottom portion 11a side of the preform 10a along the shape of the bottom portion 11a of the preform 10a.

Step of preparing a preform The preform 10a can be produced by injection molding a resin material such as polyethylene described above using a conventionally known device.

Further, by producing the multi-layer preform 10a having two or more layers by injection molding, the container body 10 can be made into a multi-layer molded bottle having two or more layers.
For example, after molding a preform 10a composed of three or more layers, the intermediate layer is a layer containing a resin (intermediate layer) having gas barrier properties and light-shielding properties such as MXD6, MXD6 + fatty acid salt, PGA, EVOH or polyethylene naphthalate. By blow molding, a multi-layer molded bottle having gas barrier properties and light-shielding properties can be obtained. As the intermediate layer, a resin or the like blended with the above-mentioned various resins may be used.

Further, by mixing an inert gas (nitrogen gas, argon gas) with the melt of the thermoplastic resin, a foamed preform having a foamed cell diameter of 0.5 to 100 μm is formed, and this foamed preform is blow-molded. By doing so, the container body 10 may be manufactured. Since such a container body 10 has a foam cell built-in, it is possible to improve the light-shielding property of the entire container body 10.

Steps for Preparing a Tube-shaped Heat-Shrinkable Plastic Member 40a In one embodiment, the tube-shaped heat-shrinkable plastic member 40a can be manufactured by a method including an extrusion molding step.
More specifically, first, the above-mentioned resin material or the like is heated and melted in an extruder, and the melted resin material or the like is continuously extruded from a ring die and cooled to form an unstretched extrusion tube 1. (See FIG. 4 (a)). The multi-layered plastic member 40a can be manufactured by co-extruding two or more resin materials.
One end of the extruded tube is then closed by welding or adhering one end of the unstretched extruded tube.
Further, the extruded tube 1 having one end closed is arranged 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 arranged (mounted) on the other end of the extrusion tube 1 (see FIG. 4C). At this time, it is preferable that the blow device 3 is brought into close contact with the extrusion tube 1 so that air does not leak between them.
Subsequently, the extrusion tube 1, the mold 2, and the blow device 3 are sent into 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 circulation type heating furnace may be used in order to keep the inside thereof at a uniform temperature. Alternatively, the extrusion tube 1, the mold 2, and the blow device 3 may be heated by passing through the heated liquid.
Next, the extrusion tube 1, the mold 2, and the blow device 3 are taken out from the heating furnace 4, and air is blown into the extrusion tube 1 from the blow device 3 to pressure-stretch the inner surface of the extrusion tube 1. As a result, the extrusion tube 1 expands and the diameter is expanded along the inner surface shape of the mold 2 (see FIG. 4 (e)).
Then, the extrusion tube 1 is cooled in cold water while the air is ejected from the blow device 3, and the extrusion tube is taken out from the mold 2 (see FIG. 4 (f)). By cutting this into a desired size, a tube-shaped heat-shrinkable plastic member 40a can be obtained (see FIG. 4 (g)).
A commercially available tubular 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 is preferably 3 mm or more longer than the preform 10a. It is more preferable that the length is 5 mm or more and 20 mm or less. By setting the above numerical range to such a value range, the thermocompression bonding step can be performed more easily, the materials used can be reduced, and the cost can be reduced.
In the present invention, the length of the heat-shrinkable plastic member 40a means the length X before heat-shrinkage, as shown in FIG. The sum of the lengths of the body portion 20a and the bottom portion 30a of the preform 10a means the length Y shown in FIG. 7.

Further, the heat-shrinkable plastic member 40a may be designed or printed. In this case, it is possible to display an image or characters on the composite container 10A without separately attaching a label or the like to the container body 10 after blow molding.
Printing can be performed by, for example, 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 UV curable ink is applied to a heat-shrinkable plastic member 40a (40), UV irradiation is performed on the heat-shrinkable plastic member 40a (40), and the ink is cured to form a print layer.
This printing may be applied to the heat-shrinkable plastic member 40a before being fitted into the preform 10a, or may be applied with the heat-shrinkable plastic member 40a provided on the outside of the preform 10a. good. Further, printing may be applied to the heat-shrinkable plastic member 40 of the composite container 10A after blow molding.

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

Heat-shrinking step The method of the present invention includes a step 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, warm 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, and is not the irradiation temperature of infrared rays, warm air, or the like.

Thermocompression bonding process The thermocompression bonding of the end (the other end) of the plastic member 40a opposite to the end where the preform 10a is fitted is shown in FIG. 8 after heating the pressure bonding portion with infrared rays, warm air, or the like. This can be done by sandwiching the pair of crimping tools 90A and B. The material of this crimping tool is not particularly limited, and a metal or heat-resistant resin can be used.
According to the crimping device as shown in FIG. 8, the end of the plastic member 40a can be thermocompression-bonded along the bottom portion 30a of the preform 10a.
The shape of the crimping tool is not particularly limited, and any crimping tool may be used as long as the plastic member 40a can be thermocompression-bonded along the bottom 30a of the preform 10a.
The surface of the crimping tool may be flat, or may have an uneven shape in part or in whole.
Further, the crimping device may have a heating mechanism on its surface. Thereby, the crimping strength can be further increased. The heating temperature of the surface of the crimping tool is preferably 100 ° C. or higher and 250 ° C. or lower, for example.

The pressure at the time of crimping ^{is preferably 50 N / cm 2} or more and 1000 N / cm ² or less, and 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 crimping 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. As a result, the appearance of the bottom portion when made into a composite container is improved.
Specifically, it is preferable to cut the preform 10a so that the length Z from the apex of the bottom portion 30a to the end of the crimped plastic member 40a is 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 that follows the shape of the bottom portion 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, is in close contact with the preform 10a so as not to move or rotate, or is not dropped by its own weight. It is in close contact.
Further, as shown in FIG. 1, the plastic member 40a has a bottomed cylindrical shape, and has a cylindrical body portion 41 and a bottom portion 42 connected to the body portion 41. In this case, since the bottom portion 42 of the plastic member 40a covers the bottom portion 30a of the preform 10a, various functions and characteristics can be imparted to the bottom portion 30 in addition to the body portion 20 of the composite container 10A.

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

Container body 10
Of 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 body portion 20 provided below the shoulder portion 12, and a body. It is provided with a bottom portion 30 provided below the portion 20. In addition, in this specification, "upper" and "lower" mean the upper part and the lower part in the state (FIG. 2) in which the composite container 10A is upright, 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 plug-type mouth portion or the like.

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. Further, the shoulder portion 12 is located between the neck portion 13 and the body portion 20, and has a shape in which the diameter gradually increases from the neck portion 13 side to the body portion 20 side.

Further, the body portion 20 has a cylindrical shape having 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 tubular shape such as a quadrangular tubular shape or an octagonal tubular shape. Alternatively, the body portion 20 may have a tubular shape having a non-uniform horizontal cross section from the upper side to the lower side. Further, in the present embodiment, the body portion 20 is not formed with irregularities and has a substantially flat surface, but the present invention is not limited to this. For example, the body portion 20 may have irregularities such as a panel or a groove.

The bottom portion 30 has a recess 31 located at the center and a ground contact portion 32 provided around the recess 31. The shape of the bottom portion 30 is not particularly limited, and may have a conventionally known bottom shape (for example, a petaloid bottom shape, a round bottom shape, or the like).

Further, the thickness of the container body 10 in the body portion 20 is not limited to this, but can be reduced to, for example, about 50 μm to 250 μm. Further, the weight of the container body 10 is not limited to this, but can be, for example, 10 g to 20 g when the content of the container body 10 is 500 ml. By reducing the wall thickness of the container body 10 in this way, the weight of the container body 10 can be reduced.

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

A thin-film 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 in order to enhance the barrier property of the container.

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

Heat shrinkable plastic member 40
The heat-shrinkable plastic member 40 is in close contact with the outer surface of the container body 10 in a thinly stretched state, and is attached to the container body 10 in a state where it does not easily move or rotate.
Further, 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, has a substantially circular horizontal cross section, and has a substantially circular horizontal cross section. One end on the bottom 30 side is crimped to form the bottom.

The plastic member 40 can be obtained by bringing the plastic member 40a provided so as to surround the outside of the preform 10a into close contact with the outside of the preform 10a and then biaxially stretching blow molding.

As shown in FIG. 2, the plastic member 40 can be provided so as to cover the shoulder portion 12, the body portion 20, and the bottom portion 30 of the container main body 10, excluding 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 body portion 20, and the bottom portion 30 of the container body 10.

The thickness of the heat-shrinkable plastic member 40 is not limited to this, but can be, for example, about 5 μm to 50 μm when attached to the container body 10.

Further, since the heat-shrinkable plastic member 40 is not welded or adhered to the container body 10, it can be separated (peeled) 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 off using a knife or the like, or the heat-shrinkable plastic member 40 is cut in advance into the heat-shrinkable plastic member 40. A wire can be provided and the heat-shrinkable plastic member 40 can be peeled off along the cutting wire. 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.

Method for manufacturing a composite container The method for manufacturing a composite container according to the present invention is as follows.
A step of heating the composite preform 70 of the present invention and inserting it into a blow molding die, and
This includes a step of integrally expanding the preform 10a and the heat-shrinkable plastic member 40a by performing blow molding on the composite preform 70 after heating.

The method for producing the composite container 10A of the present invention will be described in more detail with reference to FIGS. 9 (a) to 9 (d).

First, the composite preform 70 is heated by the heating device 51 (see FIG. 9A). At this time, the composite preform 70 is uniformly 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 10A is molded using the blow molding die 50. In this case, the blow molding die 50 includes a pair of body molds 50a and 50b that are separated from each other and a bottom mold 50c (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 10a, and biaxial stretch blow molding is performed on the composite preform 70.

As a result, the container body 10 can be obtained from the preform 10a 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 molding die 50, the preform 10a of the composite preform 70 and the plastic member 40a are integrally expanded. As a result, the preform 10a and the plastic member 40a are integrally shaped into a shape corresponding to the inner surface of the blow molding die 50.

In this way, the 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. 9D, the pair of body molds 50a and 50b and the bottom mold 50c are separated from each other, and the composite container 10A is taken out from the blow molding mold 50.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Step of preparing preform 10a)
Using an injection molding machine, a PET preform 10a shown in FIG. 7 was produced. 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.

(Step of preparing the heat-shrinkable plastic member 40a)
The polyolefin resin was melted and extruded from a ring-shaped die. Next, the inner surface of the extruded tube was pressurized, or the outer surface of the tube was negatively pressured from the inner surface to increase the diameter, thereby producing a heat-shrinkable plastic member 40a.
The length X of the produced heat-shrinkable plastic member 40a was 100 mm.

(Matching process)
Then, the preform 10a was manually fitted from one end of the heat-shrinkable plastic member 40a.

(Heat shrinkage and thermocompression bonding process)
After fitting, the preform 10a and the heat-shrinkable plastic member 40a were heated to 100 ° C. using an infrared heater, and the heat-shrinkable plastic member 40a was heat-shrinked.
Next, using a pair of crimping tools 90A and B 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} , so that the shape of the bottom portion 11a of the preform 10a is followed. The composite preform 70 was obtained by thermocompression bonding.

(Manufacturing of composite container 10A)
The composite preform 70 obtained as described above was heated to 100 ° C. using an infrared heater and conveyed to the 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 covered up to the bottom of the container body 10, no peeling or breakage of the crimping portion was observed, and the presence of air bubbles could not be confirmed.

Claims (5)

A mouth portion, a body portion connected to the mouth portion, and a preform having a bottom portion connected to the body portion.
It is provided with a plastic member provided so as to surround the outside of the preform.
The plastic member is configured as a separate body from the preform, and is provided by fitting the plastic member into the preform.
One end of the plastic member on the bottom side of the preform forms the bottom in a state of being crimped along the shape of the bottom of the preform.
A composite preform, wherein the plastic member is not welded or adhered to the preform. A composite container which is a blow-molded product of the composite preform according to claim 1.
A mouth portion, a neck portion provided below the mouth portion, a shoulder portion provided below the neck portion, a body portion provided below the shoulder portion, and a bottom portion provided below the body portion. With the container body and
A plastic member provided in close contact with the outside of the container body is provided.
One end of the plastic member on the bottom side of the container body forms the bottom in a crimped state.
A composite container, wherein the plastic member is not welded or adhered to the container body. A step of preparing a preform having a mouth portion, a body portion connected to the mouth portion, and a bottom portion connected to the body portion.
The process of preparing a tubular plastic member longer than the preform, and
The process of fitting the preform from one end of the plastic member,
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 is included.
A method for producing a composite preform, wherein the plastic member is not welded or adhered to the preform. The composite preform according to claim 3, further comprising a step of cutting so that the length from the apex of the bottom of the preform to the end of the plastic member is 0.5 mm or more and 5 mm or less. Production method. The method for producing a composite preform 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 lengths of the body and the bottom of the preform.

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