JP7169557B2 - Composite preform and manufacturing method thereof, composite container and manufacturing method thereof, and heat-shrinkable plastic member - Google Patents

Description

The present invention relates to a composite preform and its manufacturing method, a composite container and its manufacturing method, and a heat-shrinkable plastic member.

2. Description of the Related Art In recent years, plastic bottles have become popular as bottles for containing liquids such as food and drink, and liquids are contained in such plastic bottles.

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

By the way, in the conventional biaxial stretch blow molding method, for example, a preform containing a single-layer material such as PET or PP, a multi-layer material, or a blend material is used to form a container shape. However, in conventional biaxial stretch blow molding processes, it is common to simply mold the preform into a container shape. Therefore, when various functions and properties (barrier properties, heat retention, etc.) are to be imparted to the container, the means for doing so are limited, for example, by changing the material constituting the preform.

WO2014/208746

On the other hand, in order to solve the above-mentioned problems, the present inventors have developed a composite container imparted with various functions and characteristics such as a light shielding property, a composite preform used for producing the composite container, and We have proposed a manufacturing method (see Patent Document 1). On the other hand, in manufacturing such a composite container, a heat-shrinkable plastic member is sometimes used. There is a demand for better light-shielding properties.

The present invention has been made in consideration of such points, and includes a composite preform and a method for manufacturing the same, a composite container and a method for manufacturing the same, which can improve the appearance of the bottom part of the composite container. and to provide a heat-shrinkable plastic member.

The present invention relates to a method of manufacturing a composite preform, comprising the steps of preparing a plastic material preform having a mouth portion, a body portion and a bottom portion, and a cylindrical heat-shrinkable plastic member having one end and the other end. a step of preparing a heat-shrinkable plastic member having a first notch and a second notch formed at positions of said one end facing each other; a step of loosely inserting the heat-shrinkable plastic member from the other end into the preform; A method of manufacturing a composite preform characterized by comprising:

The present invention provides a method for manufacturing a composite preform, comprising the steps of preparing a plastic material preform having a mouth portion, a body portion and a bottom portion, preparing a heat-shrinkable plastic member, a step of loosely inserting a plastic member into the preform; a step of heat-shrinking the heat-shrinkable plastic member to bring the heat-shrinkable plastic member into close contact with the outside of the preform; Forming a first notch and a second notch at positions facing each other on one end of the open side of the heat-shrinkable plastic member. .

In the present invention, a first piece and a second piece separated from each other by the first cut and the second cut are formed at the one end of the heat-shrinkable plastic member, and the heat-shrinkable plastic A method of manufacturing a composite preform, comprising a step of crimping a portion of the first piece and a portion of the second piece to each other after the step of thermally shrinking the manufactured member.

The present invention provides a method for manufacturing a composite container, comprising steps of manufacturing a composite preform by the method for manufacturing a composite preform, and blow molding the preform and the heat-shrinkable plastic member of the composite preform. and expanding the preform and the heat-shrinkable plastic member integrally by applying a heat-shrinkable plastic member.

The present invention provides a composite preform comprising a preform made of a plastic material having a mouth portion, a body portion and a bottom portion, and a tubular heat-shrinkable plastic member provided so as to surround the outside of the preform. The heat-shrinkable plastic member has a cylindrical large-diameter portion covering at least the body portion of the preform, and a reduced-diameter portion extending outward from the bottom portion of the preform, The composite preform is characterized in that a first notch and a second notch are formed at positions facing each other in the reduced-diameter portion.

In the present invention, a first piece and a second piece separated from each other by the first cut portion and the second cut portion are formed in the reduced diameter portion, and a part of the first piece and the second piece are formed. A composite preform characterized in that some of the pieces are crimped together.

The present invention provides a composite container, which is a blow-molded article of the composite preform, comprising a container body having a mouth portion, a body portion and a bottom portion, and a heat-shrinkable plastic material provided in close contact with the outside of the container body. The heat-shrinkable plastic member is crimped at a position covering the bottom of the container body.

The present invention is a heat-shrinkable plastic member that is mounted so as to surround the outside of a preform, comprising a tubular main body portion having one end and the other end, and at positions facing each other at the one end, A heat-shrinkable plastic member characterized by having a first notch and a second notch.

According to the present invention, it is possible to improve the appearance of the bottom part of the composite container.

1 is a partial vertical sectional view showing a composite container according to one embodiment of the present invention; FIG. 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 of the present invention; FIG. 3 is a partial vertical cross-sectional view showing a composite preform according to one embodiment of the invention; FIG. 4 is a perspective view showing the periphery of the bottom portion of the composite preform according to one embodiment of the present invention; FIG. 5 is a perspective view showing a heat-shrinkable plastic member before heat-shrinking; 6A to 6G are schematic diagrams showing a method for manufacturing a composite preform and a method for manufacturing a composite container according to one embodiment of the present invention; FIG. FIG. 7 is a perspective view showing the periphery of the bottom portion of the composite preform according to a modification of the present invention;

An embodiment of the present invention will be described below with reference to the drawings. 1 to 6 are diagrams showing one embodiment of the present invention.

(Structure of composite container)
First, the outline of the composite container according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG.
In this specification, the terms "upper" and "lower" respectively refer to the upper and lower sides when the composite container 10A is erected (FIG. 1).

The composite container 10A shown in FIGS. 1 and 2 is molded into a composite preform 70 (see FIG. 3) including the preform 10a and the heat-shrinkable plastic member 40a using a blow molding die 50, as will be described later. It is obtained by integrally expanding the preform 10a of the composite preform 70 and the heat-shrinkable plastic member 40a by applying biaxial stretch blow molding.

Such a composite container 10A comprises an inner container body 10 made of a plastic material and a heat-shrinkable plastic member 40 provided in close contact with the outside of the 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 portion 20 provided below the shoulder portion 12. and a bottom portion 30 provided below the portion 20 .

On the other hand, the heat-shrinkable plastic member 40 is adhered to the outer surface of the container body 10 in a thinly stretched state, and attached to the container body 10 in such a manner that it cannot be easily moved or rotated.

Next, the container main body 10 will be described in detail. The container body 10 has the mouth portion 11, the neck portion 13, the shoulder portion 12, the body portion 20, and the bottom portion 30 as described above.

Of these, the mouth portion 11 has a threaded portion 14 to be screwed onto a cap (not shown) and a flange portion 17 provided below the threaded portion 14 . In addition, the shape of the mouth portion 11 may be a conventionally known shape.

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

Furthermore, the trunk portion 20 has a cylindrical shape with a substantially uniform diameter as a whole. However, the shape is not limited to this, and the trunk portion 20 may have a polygonal tubular shape such as a quadrangular tubular shape or an octagonal tubular shape. Alternatively, the body 20 may have a cylindrical shape with a non-uniform horizontal cross-section from top to bottom. Moreover, in the present embodiment, the trunk portion 20 has no irregularities and has a substantially flat surface, but the surface is not limited to this. For example, the body portion 20 may be formed with unevenness such as panels or grooves.

On the other hand, the bottom portion 30 has a recess 31 located in the center and a grounding portion 32 provided around the recess 31 . The shape of the bottom portion 30 is also not particularly limited, and may have a conventionally known bottom portion shape (for example, a petaloid bottom shape, a round bottom shape, or the like).

Moreover, the thickness of the container body 10 at the trunk portion 20 is not limited to this, but can be reduced to, for example, approximately 50 μm or more and 250 μm or less. Further, the weight of the container body 10 is not limited to this, but can be 10 g or more and 20 g or less. By reducing the wall 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 blow molding a preform 10a (described later) produced by injection molding a synthetic resin material. As the material of the preform 10a, that is, the container body 10, thermoplastic resins, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), and PC (polycarbonate) can be used. preferable. The container body 10 may be colored in red, blue, yellow, green, brown, black, white, or the like, but is preferably colorless and transparent in consideration of ease of recycling. Moreover, you may blend and use the various resin mentioned above. Further, a deposited 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 improve the barrier properties of the container.

Further, the container body 10 can also be formed as a multi-layer molded bottle having two or more layers. That is, by extrusion molding or injection molding, for example, the intermediate layer is made of MXD6, MXD6 + fatty acid salt, PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer), PEN (polyethylene naphthalate), etc., with gas barrier properties and light shielding properties. A multi-layer bottle having gas barrier properties and light shielding properties may be formed by molding a preform 10a having three or more layers as the resin (intermediate layer), followed by blow molding. As the intermediate layer, a resin obtained by blending the various resins described above may be used.

In addition, by mixing an inert gas (nitrogen gas, argon gas) with a melt of a thermoplastic resin, a foamed preform having a foamed cell diameter of 0.5 μm or more and 100 μm or less is molded, and this foamed preform is blow molded. By doing so, the container body 10 may be produced. Since such a container body 10 incorporates foam cells, the light shielding property of the entire container body 10 can be enhanced.

Such a container main body 10 may be made of a bottle with a full filling volume of 100 ml or more and 2000 ml or less, for example. Alternatively, the container body 10 may be a large bottle with a full filling capacity of, for example, 10 L or more and 60 L or less.

Next, the heat-shrinkable plastic member 40 will be described. The heat-shrinkable plastic member 40 (40a) is provided so as to surround the outside of the preform 10a, as will be described later, and is closely attached to the outside of the preform 10a and then biaxially stretch blow molded together with the preform 10a. It is obtained by As will be described later, the heat-shrinkable plastic member 40 is produced by stretching a tubular heat-shrinkable plastic member 40a together with the preform 10a.

The heat-shrinkable plastic member 40 is attached to the outer surface of the container body 10 without being adhered, and is in close contact with the container body 10 so as not to move or rotate. The heat-shrinkable plastic member 40 is thinly stretched on the outer surface of the container body 10 to cover the container body 10 . Further, as shown in FIG. 2, the heat-shrinkable plastic member 40 is provided over the entire circumference of the container body 10 so as to surround it, and has a substantially circular horizontal cross section.

In this case, the heat-shrinkable plastic member 40 is provided so as to cover the neck portion 13 , the shoulder portion 12 , the body portion 20 and the bottom portion 30 of the container body 10 excluding the mouth portion 11 . Thereby, desired functions and characteristics can be imparted to the neck portion 13 , the shoulder portion 12 , the body portion 20 and the bottom portion 30 of the container body 10 . In FIG. 1, the heat-shrinkable plastic member 40 is crimped at a position covering the bottom portion 30 of the container body 10 . Specifically, the first piece 47a and the second piece 47b (FIG. 4) of the heat-shrinkable plastic member 40a of the composite preform 70, which will be described later, are thermally compressed so as to overlap each other. As a result, the opening 48d (FIGS. 3 and 4) of the heat-shrinkable plastic member 40a is closed after blow molding, and the bottom portion 30 is completely covered by the heat-shrinkable plastic member 40. FIG.

Since the heat-shrinkable plastic member 40 is not welded or adhered to the container body 10, it can be peeled off from the container body 10 and removed. Specifically, for example, the heat-shrinkable plastic member 40 is cut using a knife or the like, or a cutting line or notch (not shown) is provided in the heat-shrinkable plastic member 40 in advance, and the cutting line or notch is used. The heat-shrinkable plastic member 40 can be peeled off. Thereby, the heat-shrinkable plastic member 40 can be separated and removed from 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 or more and 500 μm or less when attached to the container body 10 .

In this embodiment, the heat-shrinkable plastic member 40 may be colored with visible light colors such as red, blue, yellow, green, brown, black, and white. Further, the heat-shrinkable plastic member 40 may be (semi-)transparent or opaque. In this case, for example, the heat-shrinkable plastic member 40 may be colored in visible light, and the container body 10 may be colorless and transparent. Alternatively, both the container body 10 and the heat-shrinkable plastic member 40 may be colored in visible light. When manufacturing the heat-shrinkable plastic member 40 colored in visible light, a pigment of visible light is added to the molding material in the process of manufacturing the heat-shrinkable plastic member 40a before blow molding by extrusion molding or the like. may be added.

(Structure of composite preform)
Next, the configuration of the composite preform according to this embodiment will be described with reference to FIG.

As shown in FIG. 3, the composite preform 70 includes a plastic material preform 10a and a substantially cylindrical heat-shrinkable plastic member 40a surrounding the preform 10a. .

Among them, the preform 10a includes a mouth portion 11a, a trunk portion 20a connected to the mouth portion 11a, and a bottom portion 30a connected to the trunk portion 20a. 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 . The trunk portion 20a corresponds to the neck portion 13, the shoulder portion 12 and the trunk 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 heat-shrinkable plastic member 40a is attached to the outer surface of the preform 10a without being glued, and is in such close contact with the preform 10a that it does not move or rotate, or is in close contact with the preform 10a such that it does not fall under its own weight. It is The heat-shrinkable plastic member 40a is provided over the entire circumference of the preform 10a so as to surround it, and has a circular horizontal cross section.

In this case, the heat-shrinkable plastic member 40a is provided so as to cover the mouth portion 11a and the entire area except for the lower surface 30b of the bottom portion 30a. Moreover, the heat-shrinkable plastic member 40a may be colored with visible light colors such as red, blue, yellow, green, brown, black, and white.

The heat-shrinkable plastic member 40a has a large diameter portion 48a and a reduced diameter portion 48b having a smaller diameter than the large diameter portion 48a. A transition portion 48c is interposed between the large diameter portion 48a and the reduced diameter portion 48b.

The large-diameter portion 48a has a substantially cylindrical shape and covers the entire region of the body portion 20a of the preform 10a. However, the large-diameter portion 48a is not limited to this, and may cover a portion of the trunk portion 20a, for example, a region other than the region 13a corresponding to the neck portion 13. As shown in FIG.

The reduced-diameter portion 48b has a generally cylindrical shape as a whole and extends outward (opposite to the mouth portion 11a) from the bottom portion 30a of the preform 10a. An opening 48d is formed in a region surrounded by the reduced diameter portion 48b. The lower surface 30b of the bottom portion 30a is exposed outward from the opening 48d. The diameter-reduced portion 48b is formed by shrinking the heat-shrinkable plastic member 40a so as to have a diameter smaller than that of the large-diameter portion 48a.
The length L1 of the reduced diameter portion 48b may be, for example, 30% or more and 100% or less of the diameter D1 of the large diameter portion 48a. Also, the diameter D2 of the reduced diameter portion 48b may be, for example, 30% or more and 90% or less of the diameter D1 of the large diameter portion 48a.

The transition portion 48c is connected to the large diameter portion 48a and the reduced diameter portion 48b. This transition portion 48c is formed along the bottom portion 30a of the preform 10a. That is, the transition portion 48c corresponds to the shape of the bottom portion 30a, and in this case constitutes part of a spherical surface. The horizontal cross section of the transition portion 48c is substantially circular, and its diameter gradually narrows from the large diameter portion 48a to the reduced diameter portion 48b.

FIG. 4 is a perspective view showing a portion of the heat-shrinkable plastic member 40a around the bottom portion 30a. As shown in FIG. 4, a first notch 49a and a second notch 49b are formed in the reduced diameter portion 48b. The first cut portion 49a and the second cut portion 49b are provided at positions facing each other in the radial direction of the reduced diameter portion 48b. The first cut portion 49a and the second cut portion 49b are formed linearly in the longitudinal direction of the preform 10a along the wall surface of the reduced diameter portion 48b. The length L2 of the first cut portion 49a and the second cut portion 49b (the length along the longitudinal direction of the preform 10a) is, for example, 3 mm or more and 20 mm or less, and does not reach the bottom portion 30a of the preform 10a. It's becoming

A first piece 47a and a second piece 47b separated from each other by a first notch 49a and a second notch 49b are formed in the reduced diameter portion 48b. The first piece 47a and the second piece 47b each have a substantially semicircular arc shape when viewed from the bottom surface direction, and are opposed to each other with an opening 48d interposed therebetween.

As described above, the first cut portion 49a and the second cut portion 49b are formed at positions facing each other in the diameter-reduced portion 48b. The pieces 47b fall in a direction approaching each other. As a result, no gap is generated between the heat-shrinkable plastic member 40a and the bottom portion 30a of the preform 10a, so that the bottom portion 30 of the container body 10 and the heat-shrinkable plastic member 40 are substantially evenly covered after blow molding. will be For this reason, there is no fear that the appearance, light shielding properties, and gas barrier properties of the heat-shrinkable plastic member 40 in the bottom portion 30 will be deteriorated. In addition, it is possible to prevent a gap between the bottom 30 of the container body 10 and the heat-shrinkable plastic member 40 due to residual air between the bottom 30 and the heat-shrinkable plastic member 40. , it is possible to prevent deterioration of the appearance.

(Configuration of heat-shrinkable plastic member)
FIG. 5 is a perspective view showing the heat-shrinkable plastic member 40a before being heat-shrunk (before being attached to the preform 10a).

As shown in FIG. 5, the heat-shrinkable plastic member 40a has a substantially cylindrical shape as a whole, and has a body portion 41 and one end 41a and the other end 41b formed at both longitudinal ends of the body portion 41, respectively. is doing. One end 41a of the body 41 is the end facing the opening 11a when the heat-shrinkable plastic member 40a is attached to the preform 10a, and the other end 41b of the body 41 is the end facing the bottom 30a. is.

In this case, a first notch 49a and a second notch 49b are formed at positions facing each other on one end 41a of the heat-shrinkable plastic member 40a. The first cut portion 49a and the second cut portion 49b are each formed linearly in the longitudinal direction of the body portion 41, and each terminates midway in the longitudinal direction of the body portion 41 from one end 41a of the body portion 41. . Also, at one end 41a of the heat-shrinkable plastic member 40a, a first piece 47a and a second piece 47b (before heat shrinkage) separated from each other by a first notch 49a and a second notch 49b are formed. ing. Note that the length L3 of the first cut portion 49a and the second cut portion 49b before heat shrinkage is, for example, 5 mm or more and 20 mm or less.

As such a heat-shrinkable plastic member 40a, a member having a heat-shrinking effect on the preform 10a is used. That is, the heat-shrinkable plastic member (outer shrinkable member) 40a is, for example, one that shrinks with respect to the preform 10a when heat is applied.

Examples of the heat-shrinkable plastic member 40a include polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, poly-4-methylpentene-1, polystyrene, AS resin, ABS resin, polyvinyl chloride, polyvinylidene chloride, poly Vinyl acetate, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, diallyl phthalate resin, fluorine resin, polymethyl methacrylate, polyacrylic acid, polymethyl acrylate, polyacrylonitrile, polyacrylamide, polybutadiene, polybutene-1, polyisoprene, Polychloroprene, ethylene propylene rubber, butyl rubber, nitrile rubber, acrylic rubber, silicone rubber, fluororubber, nylon 6, nylon 6,6, nylon MXD6, aromatic polyamide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polynaphthalene Acid ethylene, 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, and the like. Of these, it is preferable to use thermoplastic non-elastic resins such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). A blend material, a multilayer structure, or a partially multilayer structure may also be used. Furthermore, various additives other than the main component resin may be added to the material of the heat-shrinkable plastic member 40a as long as the characteristics are not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, release agents, anti- Oxidizing agents, ion exchange agents, color pigments, and the like can be added. In addition, by mixing an inert gas (nitrogen gas, argon gas) with a melt of a thermoplastic resin, a foamed member having a foamed cell diameter of 0.5 μm or more and 100 μm or less can be used to mold this foamed preform. can enhance the light shielding property.

Also, the heat-shrinkable plastic member 40a may be made of the same material as the container body 10 (preform 10a). In this case, the heat-shrinkable plastic member 40 can be placed intensively on, for example, a portion of the composite container 10A whose strength is desired to be increased, thereby selectively increasing the strength of that portion. Examples of such materials include thermoplastic resins, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), and PC (polycarbonate).

The heat-shrinkable plastic member 40a may be made of a material having gas barrier properties such as oxygen barrier properties or water vapor barrier properties. In this case, the gas barrier properties of the composite container 10A are improved, oxygen is prevented from entering the container, and deterioration of the liquid content is prevented without using a multi-layered preform or a preform containing a blend material as the preform 10a. In addition, evaporation of water vapor from the inside of the container to the outside can be prevented, and reduction of the content can be prevented. Such materials include PE (polyethylene), PP (polypropylene), MXD-6 (nylon), PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer), or oxygen It is also conceivable to mix absorbent materials.

Also, the heat-shrinkable plastic member 40a may be made of a material having light barrier properties such as ultraviolet rays. In this case, the light barrier property of the composite container 10A can be improved without using a multi-layered preform or a preform containing a blend material as the preform 10a, and deterioration of the content liquid due to ultraviolet rays or the like can be prevented. Such a material may be a blend material or a material obtained by adding a light-shielding resin to PET, PE, or PP. Also, a foam member having a foam cell diameter of 0.5 μm or more and 100 μm or less, which is produced by mixing an inert gas (nitrogen gas, argon gas) into a melt of a thermoplastic resin, may be used.

Also, the heat-shrinkable plastic member 40a may be made of a material having a higher cold-retaining property (a material having a lower thermal conductivity) than the plastic material forming 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. Thereby, the cold insulating property of the composite container 10A is enhanced. Moreover, when the user grips the composite container 10A, it is possible to prevent the composite container 10A from being difficult to hold due to being too cold. Such materials include foamed polyurethane, polystyrene, PE (polyethylene), PP (polypropylene), phenol resin, polyvinyl chloride, urea resin, silicone, polyimide, melamine resin, and the like. It is preferable to mix hollow particles with the resin material containing these resins. The average particle diameter of the hollow particles is preferably 1 μm or more and 200 μm or less, more preferably 5 μm or more and 80 μm or less. The "average particle size" means the volume average particle size, and is measured by a known method using a particle size distribution/particle size distribution analyzer (e.g., Nanotrac particle size distribution analyzer manufactured by Nikkiso Co., Ltd.). can do. The hollow particles may be organic hollow particles made of resin or the like, or inorganic hollow particles made of glass or the like. Hollow particles are preferred. 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, and polyimides. resins, polycarbonate resins, polyether resins, and the like. In addition, Low Pake HP-1055, Low Pake HP-91, Low Pake OP-84J, Low Pake Ultra, Low Pake SE, Low Pake ST (manufactured by Rohm and Haas Co., Ltd.), Nipol MH-5055 (manufactured by Nippon Zeon Co., Ltd.), SX8782 , SX866 (manufactured by JSR Corporation) and other commercially available hollow particles 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 1 part by mass or more and 20 parts by mass with respect to 100 parts by mass of the resin material contained in the heat-shrinkable plastic member 40a. Part or less is more preferable.

Also, the heat-shrinkable plastic member 40a 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, the composite container 10A can be easily gripped by the user without changing the material of the container body 10 .

The heat-shrinkable plastic member 40a may be previously printed with a design or print. In this case, printing may be performed by applying a design or print to the plain heat-shrinkable plastic member 40a by a printing method such as an inkjet method or a gravure printing method. This printing may be applied to the heat-shrinkable plastic member 40a before being attached to the preform 10a, or may be applied while the heat-shrinkable plastic member 40a is provided outside the preform 10a. good. The heat-shrinkable plastic member 40a may be colored in red, blue, yellow, green, brown, black, white, or the like, and may be transparent or opaque.

(Manufacturing method of composite preform)
Next, a method of manufacturing the composite preform 70 according to this embodiment will be described with reference to FIGS. 6(a) to 6(c).

First, a preform 10a made of plastic material is prepared (see FIG. 6(a)). In this case, for example, the preform 10a is produced by an injection molding method using an injection molding machine (not shown). This preform 10a has a mouth portion 11a, a cylindrical body portion 20a, and a substantially hemispherical bottom portion 30a.

Next, a substantially cylindrical heat-shrinkable plastic member 40a having one end 41a and the other end 41b is prepared (FIG. 5). A first notch 49a and a second notch 49b are formed at positions facing each other on one end 41a of the heat-shrinkable plastic member 40a.

Subsequently, a heat-shrinkable plastic member (outer shrinkable member) 40a is provided (loosely inserted) on the outside of the preform 10a (see FIG. 6B). In this case, the heat-shrinkable plastic member 40a is loosely inserted into the preform 10a from the other end 41b side. After being loosely inserted into the preform 10a, the heat-shrinkable plastic member 40a is attached so as to cover the entire body portion 20a and the bottom portion 30a of the preform 10a when viewed from the side. One end 41a of the heat-shrinkable plastic member 40a protrudes outside the bottom portion 30a of the preform 10a (opposite side of the mouth portion 11a).

Next, the preform 10a and the heat-shrinkable plastic member 40a are heated by the heating device 55 (see FIG. 6(c)). At this time, the preform 10a and the heat-shrinkable plastic member 40a are evenly heated in the circumferential direction by the heating device 55 while rotating with the opening 11a facing downward. The heating temperature of the preform 10a and the heat-shrinkable plastic member 40a in this heating step may be, for example, 90.degree. C. to 130.degree.

By heating the heat-shrinkable plastic member 40a in this manner, the heat-shrinkable plastic member 40a is heat-shrunk and adheres to the outside of the preform 10a (see FIG. 6(c)). At this time, the heat-shrinkable plastic member 40a adheres to the preform 10a along the body portion 20a and the bottom portion 30a to form a large diameter portion 48a and a transition portion 48c.
On the other hand, the portion of the heat-shrinkable plastic member 40a protruding outside the bottom portion 30a of the preform 10a shrinks radially inward to form a diameter-reduced portion 48b. At this time, a first piece 47a and a second piece 47b separated from each other by a first notch 49a and a second notch 49b are formed in the reduced diameter portion 48b (see FIG. 4).

By providing the heat-shrinkable plastic member 40a on the outside of the preform 10a in this way, a composite preform having the preform 10a and the heat-shrinkable plastic member 40a in close contact with the outside of the preform 10a can be obtained. 70 is obtained (see FIG. 6(c)).

In this way, the heat-shrinkable plastic member 40a is brought into close contact with the outside of the preform 10a in advance to produce the composite preform 70, thereby producing a series of steps for producing the composite preform 70 (Fig. 6(a)). (c)) and a series of steps (FIGS. 6(d) to (g)) for manufacturing a composite container 10A by blow molding, which will be described later, can be performed at separate locations (factories, etc.).

In the above description, the case where the heat-shrinkable plastic member 40a, in which the first cut portion 49a and the second cut portion 49b are formed in advance, is attached to the preform 10a has been described as an example. However, not limited to this, the first cut 49a and the second cut 49b may be formed after the heat-shrinkable plastic member 40a is attached to the preform 10a.

In this case, first, the preform 10a is prepared as in the above case. Next, the heat-shrinkable plastic member 40a without the first cut 49a and the second cut 49b is prepared. Next, the heat-shrinkable plastic member 40a is loosely inserted into the preform 10a, and then the heat-shrinkable plastic member 40a is heat-shrunk to extend the heat-shrinkable plastic member 40a to the outside of the preform 10a. make close contact. After that, a first notch 49a and a second notch 49b are formed at positions facing each other on one end 41a on the open side of the heat-shrinkable plastic member 40a. A composite preform 70 is thus obtained (see FIG. 3).

(Manufacturing method of composite container)
Next, a manufacturing method (blow molding method) of the composite container 10A according to the present embodiment will be described with reference to FIGS. 6(d) to 6(g).

For example, the composite preform 70 is produced by the above-described steps (see FIGS. 6(a) to 6(c)). Next, the composite preform 70 is heated by the heating device 51 (see FIG. 6(d)). At this time, the composite preform 70 is evenly heated in the circumferential direction by the heating device 51 while rotating with the opening 11a facing downward. The heating temperature of the preform 10a and the heat-shrinkable plastic member 40a in this heating step may be, for example, 90.degree. C. to 130.degree.

Subsequently, the composite preform 70 heated by the heating device 51 is sent to the blow molding die 50 (see FIG. 6(e)).

The composite container 10A is molded using this blow molding die 50. As shown in FIG. In this case, the blow-molding mold 50 is composed of a pair of split body molds 50a and 50b and a bottom mold 50c (see FIG. 6(e)). In FIG. 6(e), the pair of body molds 50a and 50b are open from 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. 6(f), the pair of trunk molds 50a and 50b are closed after the bottom mold 50c is lowered, and the pair of trunk molds 50a and 50b and the bottom mold 50c are closed. A blow molding mold 50 is constructed. Next, air is forced into the preform 10a and the composite preform 70 is subjected to biaxial stretch blow molding.

As a result, the container body 10 is obtained from the preform 10a in the blow molding die 50. As shown in FIG. During this time, the body molds 50a, 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 heat-shrinkable plastic member 40a are expanded together. As a result, the preform 10 a and the heat-shrinkable plastic member 40 a are integrally formed into a shape corresponding to the inner surface of the blow molding die 50 .

Thus, a composite container 10A comprising the container body 10 and the heat-shrinkable plastic member 40 provided on the outer surface of the container body 10 is obtained. At this time, the first piece 47a and the second piece 47b (FIG. 4) formed on the diameter-reduced portion 48b of the heat-shrinkable plastic member 40a collapse toward each other. As a result, the heat-shrinkable plastic member 40 a is crimped at a position covering the bottom portion 30 of the container body 10 . At this time, since no gap is generated between the heat-shrinkable plastic member 40a and the bottom portion 30a of the preform 10a, the bottom portion 30 of the container body 10 is substantially evenly covered with the heat-shrinkable plastic member 40, and the bottom portion 30 is covered with the heat-shrinkable plastic member 40. There is no possibility that the external appearance of the heat-shrinkable plastic member 40 will be deteriorated. In addition, since air is less likely to accumulate between the bottom portion 30 of the container body 10 and the heat-shrinkable plastic member 40, it is possible to prevent the formation of a gap between the heat-shrinkable plastic member 40 and the bottom portion 30. .

Next, as shown in FIG. 6(g), the pair of body molds 50a and 50b and the bottom mold 50c are separated from each other, and the composite container 10A is removed from the blow molding mold 50. Next, as shown in FIG.

As described above, according to the present embodiment, the first notch 49a and the second notch 49b are formed at positions facing each other in the reduced diameter portion 48b of the heat-shrinkable plastic member 40a. As a result, when the composite preform 70 is blow-molded, the reduced-diameter portion 48b is deformed so that the first piece 47a and the second piece 47b are narrowed, so that the bottom portion 30 of the container body 10 and the heat-shrinkable plastic after blow-molding. The material 40 can be uniformly adhered to the bottom 30, and the appearance, light shielding property, and gas barrier property of the bottom portion 30 can be improved. In addition, it is possible to prevent air from remaining between the bottom portion 30 of the container body 10 and the heat-shrinkable plastic member 40, thereby preventing the appearance from deteriorating. As a result, the composite container 10A provided with various functions and characteristics such as light shielding properties and gas barrier properties can be manufactured with high quality.

Furthermore, according to the present embodiment, when manufacturing the composite container 10A, a general blow molding apparatus can be used as it is, so there is a need to prepare new molding equipment for manufacturing the composite container 10A. do not have. Moreover, since the heat-shrinkable plastic member 40a is provided outside the preform 10a, there is no need to prepare new molding equipment for molding the preform 10a.

(Modification)
Next, a modified example of the composite preform 70 according to this embodiment will be described with reference to FIG. The modification shown in FIG. 7 is different in that a portion of the first piece 47a and a portion of the second piece 47b are crimped to each other. It is substantially the same as the embodiment shown. In FIG. 7, the same parts as in FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 7, in the composite preform 70, a first piece 47a and a second piece 47b separated from each other by a first cut portion 49a and a second cut portion 49b are formed in the reduced diameter portion 48b. there is

In this case, a portion of the first piece 47a and a portion of the second piece 47b are crimped to each other. Specifically, a first crimping portion 47c positioned substantially midway between the first cut portion 49a and the second cut portion 49b of the first piece 47a, and the first cut portion 49a and the second cut portion 49b of the second piece 47b. A second pressure-bonding portion 47d positioned substantially midway between the notch portion 49b and the second pressure-bonding portion 47d are thermally pressure-bonded to each other. As a result, the first crimping portion 47c and the second crimping portion 47d are connected to each other, and the first piece 47a and the second piece 47b are integrated. Also, the first piece 47a and the second piece 47b are formed in a w shape or an omega shape, respectively, when viewed from the bottom direction.

When manufacturing such a composite preform 70, after the step of heat-shrinking the heat-shrinkable plastic member 40a (FIG. 6(c)), the step of heating the composite preform 70 with a heating device 51 (FIG. 6 ( d)) is preceded by the step of crimping a portion of the first piece 47a and a portion of the second piece 47b together. Specifically, while the heat-shrinkable plastic member 40a is at a high temperature immediately after the heat-shrinking step (FIG. 6(c)), a tool for heat-pressing (not shown) or the like is used to compress the first piece. By sandwiching the first crimped portion 47c of 47a and the second crimped portion 47d of the second piece 47b toward the inside, the first crimped portion 47c and the second crimped portion 47d are crimped (see the arrow in FIG. 7). . Alternatively, after the heat-shrinkable plastic member 40a has cooled, it may be melt-pressed using a heated tool (not shown) or the like. Further, after the heat-shrinkable plastic member 40a has cooled, a tool (not shown) or the like may be ultrasonically vibrated to utilize the heat generated by the vibration to melt and pressure-bond.

As described above, when the composite preform 70 shown in FIG. 7 is used, when the composite preform 70 is blow-molded, the diameter-reduced portion 48b is deformed so that the first piece 47a and the second piece 47b are narrowed. After blow molding, the bottom portion 30 of the container body 10 and the heat-shrinkable plastic member 40 are evenly adhered to each other, and the appearance of the bottom portion 30 can be improved. At the same time, since air is discharged from the opening 48d in the blow molding process, air remaining between the bottom portion 30 of the container body 10 and the heat-shrinkable plastic member 40 is more effectively prevented. be able to. Furthermore, since a part of the first piece 47a and a part of the second piece 47b are crimped to each other, the bottom 30 of the container body 10 and the heat-shrinkable plastic member 40 are more securely attached. , the composite container 10A having a good appearance and excellent light-shielding properties can be manufactured with high quality.

Reference Signs List 10 container body 10A composite container 10a preform 11, 11a mouth 12 shoulder 13 neck 14 screw 17 flange 20, 20a body 30, 30a bottom 40a heat-shrinkable plastic member 47a first piece 47b second piece 48a Large-diameter portion 48b Reduced-diameter portion 48c Transition portion 48d Opening 49a First cut portion 49b Second cut portion 70 Composite preform

Claims (8)

In the method for manufacturing a composite preform,
providing a plastics material preform having a mouth, a body and a bottom;
A tubular plastic member having one end and the other end, wherein a first notch and a second notch are formed at positions facing each other in the radial direction of the one end, respectively. the process of preparing,
and a step of closely contacting the plastic member to the outside of the preform. In the method for manufacturing a composite preform,
providing a plastics material preform having a mouth, a body and a bottom;
providing a plastic member;
a step of adhering the plastic member to the outside of the preform;
forming a first notch and a second notch at positions facing each other in the radial direction of one end of the open side of the plastic member, respectively. A first piece and a second piece separated from each other by the first cut and the second cut are formed at the one end of the plastic member,
3. A step of crimping a portion of said first piece and a portion of said second piece to each other is provided after the step of closely contacting said plastic member to the outside of said preform. 3. A method for manufacturing a composite preform according to 1 or 2. In the method for manufacturing a composite container,
A step of producing a composite preform by the method for producing a composite preform according to any one of claims 1 to 3;
Blow molding the preform and the plastic member of the composite preform to integrally expand the preform and the plastic member. Method. In composite preforms,
a plastics material preform having a mouth, a body and a bottom;
a cylindrical plastic member provided to surround the outside of the preform,
The plastic member has a cylindrical large-diameter portion covering at least the body portion of the preform and a reduced-diameter portion extending outward from the bottom portion of the preform,
A composite preform, wherein a first notch and a second notch are formed at positions facing each other in a radial direction of the diameter-reduced portion. A first piece and a second piece separated from each other by the first cut portion and the second cut portion are formed in the reduced diameter portion, and a portion of the first piece and a portion of the second piece are formed. 6. The composite preform according to claim 5, wherein the and are crimped together. A composite container that is a blow-molded product of the composite preform according to claim 5 or 6,
a container body having a mouth portion, a trunk portion, and a bottom portion;
A plastic member provided in close contact with the outside of the container body,
A composite container, wherein the plastic member is crimped at a position covering the bottom of the container body. A plastic member mounted so as to surround the outside of the preform,
A cylindrical body having one end and the other end,
A plastic member, wherein a first notch and a second notch are formed at positions facing each other in the radial direction of the one end.

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