JPH0740958A - Composite container - Google Patents

Abstract

PURPOSE:To provide a composite container which is equipped with an excellent barrier property and can stably store any substance such as powder or liquid, etc., by a method wherein a decomposable plastic is injected into a die, and integrated with a blank sheet with a barrier property which is previous arranged in the die. CONSTITUTION:A blank sheet 3 is previously arranged between a core and female die of an injection-molding die, and a decomposable plastic is injected. By doing so, a pillar part 4, flange part 5, shoulder part 10 and a threaded mouth part 11 are formed. At this time, the bland sheet whose shape is maintained cylindrically is integrated by fusing with the decomposable plastic constituting the pillar part 4, flange part 5, and the shoulder part 10 respectively, at the end parts, a lower open end 3b and upper open end 3c. For a bottom part 6 also, a blank sheet 8 for the bottom part is previously arranged in the injection-molding die, and then, a flange part 7 can be integrally formed on the periphery of the blank sheet 8 by injecting the decomposable plastic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite container having advantages such as molding precision, strength and processing characteristics as an injection molded product, printing effect as a paper container, and lightness, and is particularly excellent. The present invention relates to a composite container which has a barrier property and can stably store any content such as powder and liquid, and which can be easily disposed of.

[0002]

2. Description of the Related Art Conventionally, a so-called pillar container in which a blank plate and a thermoplastic resin are integrally molded is used.

Generally, in a pillared container, a blank plate made of a laminated sheet material in which paper and a resin are laminated is arranged in a cylindrical shape in an injection molding die, and the end portion of the blank plate is abutted with each other. In addition, the blank container is a composite container integrally molded in a state where the blank plate is held in a container shape by a holding frame made of resin by injecting a thermoplastic resin into the open end and the like. Here, in general, the blank plate has a laminated structure including a barrier layer made of an aluminum foil, an ethylene-vinyl alcohol copolymer or the like, and a thermoplastic resin layer located on the innermost surface. Then, the injected thermoplastic resin and the thermoplastic resin layer on the innermost surface are fused by heat to be integrated into a composite container, and the strength of the molded composite container is high.

Such a pillar container has both advantages as an injection molded product and as a paper container, and also has a barrier property. For example, soft drinks, sake, powder detergent, fragrance, liquid foods, etc. It is widely used as a container for various products.

[0005]

DISCLOSURE OF THE INVENTION Conventionally, the disposal treatment of the above-mentioned composite container after use has been carried out by incineration or landfill. However, in the case of incineration, a high heat resistant furnace capable of withstanding the large combustion energy of the composite container is required, resulting in high treatment cost. Further, in the case of landfill, since the composite container using a barrier material such as aluminum foil or plastic does not decompose and exists in the ground as it is, there is a problem that the ground of the landfill is not stable. Furthermore, since the composite container scattered on the ground is not degradable, it remains semi-permanently as garbage,
There was a problem of damaging the environment.

The present invention has been made in view of the above circumstances, has an excellent barrier property, can stably contain any contents such as powder and liquid, and disassembles the entire container. An object of the present invention is to provide a composite container having properties.

[0007]

To achieve these objects, the present invention comprises a body, a bottom, and an upper closure.
The blank plate and the decomposable plastic injected into the injection molding die in which the blank plate was previously arranged were integrally molded.

[0008]

The thermoplastic resin which is injected into the injection molding die in which the blank plate constituting the container is preliminarily arranged and is integrated with the blank plate is degradable plastic, whereby the composite container as a whole is degradable. Equipped with.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of the composite container of the present invention, and FIG. 2 is a sectional view taken along line II-II of the composite container shown in FIG. In FIGS. 1 and 2, the composite container 1 is a so-called pillar container including a body portion 2, a bottom portion 6, and an upper closing portion 9.

The body portion 2 of the composite container 1 is formed by injecting degradable plastic into a blank plate 3 held in a cylindrical shape and a joint portion where the end portions 3a of the blank plate 3 are butted. It is provided with a pillar portion 4 and a flange portion 5 formed by injecting decomposable plastic into the lower open end 3b of the blank plate 3 held in a cylindrical shape.

The bottom portion 6 is composed of a flange portion 7 formed of degradable plastic around a blank plate 8 for the bottom portion, and is formed separately from the body portion 2.
The flange portion 7 is integrated with the body portion 2 by being fixed to the inner peripheral surface of the flange portion 5 of the body portion 2. The flange portion 7 and the inner peripheral surface of the flange portion 5 may be fixed to each other by forming a screw portion and screwing them together, or by various methods such as a heat sealing method and an ultrasonic sealing method.

Further, the upper closed portion 9 comprises a shoulder portion 10 and a threaded opening portion 11 projecting from the shoulder portion 10 substantially at the center thereof. The upper closing portion 9 is formed integrally with the body portion 2 and is located above the open end 3c of the blank plate 3 held in a tubular shape.
It is formed by injecting degradable plastic. Then, for example, a cap, a cap with a pump (shown by an imaginary line in FIG. 1), or the like is screwed into the threaded opening 11 to seal the inside of the composite container 1.

The composite container 1 as described above has a blank plate 3
Is previously disposed between the core of the injection molding die and the female die, and then the decomposable plastic is injected, whereby the pillar portion 4, the flange portion 5, the shoulder portion 10 and the threaded opening are formed. The part 11 is molded, and at this time, the blank plate 3 held in a cylindrical shape has the pillar part 4, the flange part 5, and the shoulder part at the ends 3a, 3a, the lower open end 3b, and the upper open end 3c, respectively. It is fused and integrated with the decomposable plastic that constitutes 10. At this time, it is preferable that the blank plate 3 be wound around the core in advance and be folded in a curl. In addition, the bottom 6 is also prepared by previously disposing a blank plate 8 for the bottom in an injection mold and then injecting degradable plastic to integrally form the flange 7 around the blank plate 8. You can

The appearance of the pillar portion 4 formed by injection of the thermoplastic resin is difficult to be confirmed from the outside of the composite container 1 because it is preferable in appearance that the amount of resin in the pillar portion 4 can be adjusted. It may be as small as possible. In addition, as shown in FIG. 2, ribs 4a are formed on the inside of the container of the pillar portion 4.
May be projected. By thus projecting the ribs 4a, stacking between the body parts is prevented when the body parts 2 before the bottom part 6 are integrated are stacked and stored or transported, and the subsequent separation is easy. Becomes

As described above, the blank plate 3 and the blank plate 8
Examples of the degradable plastic which is integrated with the above and constitutes the composite container 1 include degradable polyethylene resin and degradable polypropylene resin. The degradable polyethylene resin and the degradable polypropylene resin are resins containing polyethylene and polypropylene as main components and capable of being decomposed by light or microorganisms.

Among the degradable polyethylene resins, examples of the photodegradable ones include copolymers of ethylene and carbon monoxide. This ethylene / carbon monoxide copolymer is
It is considered that the cleavage occurs due to light between the second and third carbons to which the carbonyl group is bonded, resulting in decomposition. The decomposition rate can be adjusted by the content of carbon monoxide in the copolymer. Usually, the density of the ethylene / carbon monoxide copolymer is about 0.89 to 0.95 g / cm ³ ,
The content of carbon monoxide is about 0.1 to 10 mol%.

The above-mentioned ethylene / carbon monoxide copolymer can be obtained, for example, by adding ethylene and carbon monoxide at a temperature of 230 ° C.
It can be produced by coexisting under a pressure of about 2000 atm.

As the photodegradable degradable polyethylene resin or degradable polypropylene resin, polyethylene (density = 0.87 to 0.95 g / cm ³ , melt index (M
I) = 0.4-40) and polypropylene (density = 0.8
7 to 0.91 g / cm ³ , melting index (MI) = 0.3 to 5
It is also possible to use a mixture of 0) and an organic acid metal salt.
Examples of the organic acid metal salt include iron stearate, cerium stearate, cobalt stearate, and the like, and metal oxides such as iron oxide, acetylacetone, and a complex with dibutyldithiocarbamate, and the like, and the mixed amount of the organic acid metal salt. Is preferably about 1 to 5000 p.pm. Further, a copolymer with vinyl ketone may be added.

Among the degradable polyethylene resin and the degradable polypropylene resin, examples of the microbial degradable resin include a mixture of polyolefin and polycaprolactone, starch, polyester polymerized by microorganisms and the like.

The polyethylene used for the microbial degradable polyethylene resin has a density of 0.87 to 0.95 g /
cm ³ , ethylene homopolymer having a melting index (MI) of 0.4 to 40, or a random or block copolymer with other olefins such as propylene, butene, hexene, octene, and 4-methylpentene-1, and Examples thereof include copolymers with monomers having an ethylenically unsaturated group such as vinyl acetate, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate and maleic anhydride. The polypropylene used for the microbial degradable polypropylene resin has a density of 0.87 to
Examples thereof include a homopolymer of propylene having 0.91 g / cm ³ and a melting index (MI) of 0.3 to 50, or a random or block copolymer with other olefins such as ethylene and butene.

Polycaprolactone used for microbial degradable plastics is obtained by ring-opening polymerization of ε-caprolactone, and its weight average molecular weight (Mw) is usually 4
It is about 0000 to 100,000. Starch is a polymer of D-glucose and is industrially produced from stems and roots of potato, sweet potato, corn, wheat and the like, and its weight average molecular weight (Mw) depends on the raw material and the production method. It greatly changes from ten thousand to tens of millions. The average particle size of such starch is preferably 10 μm or less.

As the polyester polymerized by the microorganism used for the microbial degradable plastic, a random copolyester of 3-hydroxybutyrate and 3-hydroxyvalerate (for example, hydrogen bacteria produced by ICI, UK) is used. Obtained by supplying propionic acid) or by supplying valeric acid to hydrogen bacteria 3
-Hydroxybutyrate-based polyester and the like can be mentioned.

The amount of polycaprolactone, starch and polyester polymerized by microorganisms in the above-mentioned microbial-degradable polyethylene resin or polypropylene resin is 100% by weight based on the total amount of polyethylene or polypropylene and each of the above-mentioned mixed components. 5 to 80% by weight is preferable. If the mixing amount of each of the above components is less than 5% by weight, sufficient microbial degradability cannot be obtained, and if it exceeds 80% by weight, the strength is weakened, which is not preferable.

Two or more kinds of each component of polycaprolactone, starch and polyester polymerized by microorganisms may be used, but in that case, the total mixing amount is 5-8.
It may be in the range of 0% by weight.

By using the above-mentioned photodegradable polyethylene resin as a raw material of the microbial degradable polyethylene resin, a degradable polyethylene resin having both photodegradability and microbial degradability can be obtained.

Further, the above degradable plastics include
In order to increase the strength, various known additives such as inorganic fillers, antioxidants, decomposition accelerators, stabilizers, antistatic agents and surfactants may be added.

The blank plate 3 is not particularly limited as long as it is a laminate having at least a paper layer, a barrier layer, and an innermost surface layer made of a thermoplastic resin in order from the outside of the composite container 1.
For example, the outermost surface layer made of a thermoplastic resin may be provided outside the paper layer.

As a concrete example of the blank plate 3, for example, FIG.
A blank plate as shown in can be mentioned. In FIG. 3, the blank plate 3 is a barrier adhered to the paper 22 via the thermoplastic resin layer (outermost surface layer) 21, the paper 22, and the adhesive resin layer 23 in this order from the side forming the outer wall surface of the composite container 1. Layer 24 and thermoplastic resin layer (innermost layer) 25
It has a laminated structure of.

Thermoplastic resin layer 2 constituting the blank plate 3
As the reference numerals 1 and 25, the same decomposable plastics as the degradable plastics that are integrated with the blank plate 3 and the blank plate 8 to form the composite container 1 as described above can be used. Since the degradable plastics as described above have heat sealing properties, the thermoplastic resin layers 21 and 2 of the blank plate are
Even if it is used as No. 5, there is no hindrance to the melt integration of the injected degradable plastic and the blank plate. The thickness of such a thermoplastic resin layer 21 is 10 to 40.
μm, the thickness of the thermoplastic resin layer 25 is 20 to 80 μm
A degree is preferable.

The thermoplastic resin layers 21 and 25 may be made of the same thermoplastic resin, or may be made of different thermoplastic resins. Paper 2 that constitutes the blank plate 3
2 preferably has a basis weight of about 200 to 400 g / m ² .

The barrier layer 24 is made of silicon oxide (SiO 2).
It can be formed of an inorganic vapor deposition film such as _x ), an ethylene-vinyl alcohol copolymer, nylon or a polyamide resin represented by the following chemical formula.

[0032]

[Chemical 1] Further, the barrier layer 24 may be formed by forming an inorganic vapor deposition film on a film made of degradable plastic.

The thickness of the barrier layer 24 is 10 to 10.
About 50 μm is preferable. Also, the paper 22 and the barrier layer 2
The adhesive resin layer 23 for adhering 4 and 4 can be formed using, for example, a carboxyl group-containing polyethylene resin. Specific examples of the carboxyl group-containing polyethylene resin include ethylene-acrylic acid copolymer (EA
A), ethylene-methacrylic acid copolymer (EMAA),
Examples thereof include ionomer resins, ethylene-maleic anhydride copolymers, ethylene-ethyl acrylate-maleic anhydride copolymers, and the like. The thickness of such adhesive resin layer 23 is preferably about 15 to 30 μm.

The blank plate 3 may have a structure in which a heat resistant layer is provided between the barrier layer 24 and the thermoplastic resin layer 25. This heat-resistant layer can be formed of a biaxially stretched polyester resin film such as a polyethylene terephthalate film, a polyamide resin film such as a nylon film, a stretched polyolefin resin film such as a polypropylene film, or the like. The thickness of such a heat-resistant layer is preferably about 10 to 30 μm.

The thickness of the blank plate 3 as described above is preferably about 300 to 600 μm. In the composite container of the present invention as described above, since the degradable plastic and the blank plate having the barrier property are integrated to form the composite container, the composite container has an excellent barrier property,
The container as a whole will have degradability.

Further, the shape of the composite container of the present invention is not limited to the above-mentioned example, but may be various shapes. For example, as shown in FIG. 4, the body forming portion 33
A blank container 32 composed of a and 33b and the upper blocking portion forming portion 34 may be used to form the composite container 31 having the shape shown in FIG. In this composite container 31, a pillar portion 36 made of a thermoplastic resin is formed at the joint portion of the blank plates 32. In addition, an upper closing portion edge portion 38 is formed in an upper closing portion 37 formed by the upper closing portion forming portion 34 of the blank plate 32, and a lower flange portion 39 is formed below the blank plate 32. There is. Then, a threaded opening 40 is fixed to a mouth portion 35 formed in the upper closed portion forming portion 34 of the blank plate 32. The threaded opening 40 may be integrally formed with the pillar portion 36 and the upper closing portion edge portion 38. In addition, a bottom material formed separately from the container is bonded to the lower flange portion 39.

As a means for integrating the body portion 2 and the bottom portion 6, the ultrasonic sealing method can be used as described above. In this case, as shown in FIG. 6, the flange portion 5 of the body portion 2 is used. A convex portion 5a can be provided on the lower end surface of the. Since such a convex portion 5a is selectively melted by ultrasonic waves, quick and reliable heat sealing can be performed. Also, to prevent the molten resin from flowing out between the flange portion 5 and the bottom portion 6,
An L-shaped edge portion 5b may be provided on the outer edge portion of the flange portion 5 as in the illustrated example. The shape of the convex portion 5a may be any shape such as a ring shape and a protrusion shape such as a cone, and the height of the convex portion 5a is 0.1 to 0.5 mm.
The angle of the top of a is preferably in the range of 60 to 120 °.
Further, the convex portion (5a) may be provided on the bottom portion 6.

Next, the present invention will be described in more detail with reference to experimental examples. (Experimental example) First, acid-resistant paper having a basis weight of 230 g / m ² was used as a support, and a low-density polyethylene resin was extrusion-laminated on one side of the acid-resistant paper to form a thermoplastic resin layer having a thickness of 15 μm, and two layers were laminated. Created the body.

On the other hand, polyvinylidene chloride-coated biaxially stretched polyester film (thickness: 12 μm) as a barrier layer.
m) and a low density polyethylene resin film (thickness = 45 μm) as a thermoplastic resin layer were formed.

Next, an ethylene / methacrylic acid copolymer (E
MAA) was extruded to a thickness of 15 μm, and the polyvinylidene chloride-coated biaxially stretched polyester film side of the other two-layer laminate was adhered to form a laminate.

Next, this laminated body was punched into a predetermined shape to obtain a body blank plate and a bottom blank plate. Then, after each blank plate was loaded into a predetermined injection mold, injection molding was performed using an ethylene / carbon monoxide copolymer which is a degradable plastic, and a body part and an upper closed part that compose the composite container were formed. A composite container (Sample 1) as shown in FIG. 1 was prepared by forming a part consisting of and a bottom part and ultrasonically sealing both parts.

For comparison, a composite container (comparative sample 1) was prepared in the same manner as the composite container (sample 1) except that injection molding was performed using polyethylene resin. For each composite container (Sample 1, Comparative Sample 1) created in this way,
Using Oxytran manufactured by Modern Control, at room temperature,
The amount of oxygen permeated under normal pressure was measured. In addition, each composite container was subjected to a photodegradation acceleration test using an ultraviolet / xenon lamp weather meter manufactured by Suga Test Instruments Co., Ltd. The measurement results are shown in Table 1 below.

[0043]

[Table 1] As shown in Table 1, it was confirmed that the composite container of the present invention has a high barrier property as well as degradability as a whole container.

[0044]

As described in detail above, according to the present invention, the decomposable plastic and the blank plate having a barrier property are integrated to form a composite container, so that the composite container has an excellent barrier property. In addition, since the container as a whole has degradability, any contents such as powder and liquid can be stably stored, and there is an effect that disposal after use is easy.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a composite container of the present invention.

2 is a sectional view taken along line II-II of the composite container shown in FIG.

FIG. 3 is a schematic cross-sectional view showing an example of a blank plate used in the composite container shown in FIG.

FIG. 4 is a plan view of a blank plate used in another example of the composite container of the present invention.

FIG. 5 is a perspective view showing another example of the composite container of the present invention.

FIG. 6 is a cross-sectional view showing an example of integration of a body portion and a bottom portion of the composite container of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Composite container 2 ... Body part 3 ... Blank plate 4 ... Pillar part 6 ... Bottom part 9 ... Upper block part 21 ... Thermoplastic resin layer 22 ... Paper 23 ... Adhesive resin layer 24 ... Barrier layer 25 ... Thermoplastic resin layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuko Yamase 1-1-1, Ichigayaka-cho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. (72) Inventor Tetsuya Oshiro Takemasawa, Miyoshi-cho, Iruma-gun, Saitama Prefecture No.402 Shinkai Nakayama Industry Co., Ltd.

Claims (3)

[Claims] 1. A blank plate, which comprises a body, a bottom, and an upper closing part, and a degradable plastic which is injected into an injection molding die in which the blank is preliminarily disposed and is molded integrally. A composite container characterized by being a container. 2. The composite container according to claim 1, wherein the blank plate has a barrier property and has a laminated structure, and at least the innermost surface layer is a degradable plastic. 3. The composite container according to claim 1, wherein the blank plate has a barrier layer formed by depositing an inorganic vapor deposition film on a film made of degradable plastic.