JPH0733172A - Multi-layer plastic container - Google Patents

Abstract

PURPOSE:To provide a container which has less smell despite the use of recycled plastic, in a multi-layer plastic container. CONSTITUTION:In a multi-layer plastic container, a polyolefin resin layer containing adsorbent, a recycled plastic resin layer, and a polyolefin resin layer containing adsorbent are bonded in that order. Alternatively, a polyolefin resin layer, a recycled plastic resin layer, and a polyolefin resin layer containing adsorbent are bonded in that order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layered plastic container, and more particularly to a multi-layered plastic container in which recycled plastic layers are laminated and which has little odor.

[0002]

2. Description of the Related Art Polyolefin resins are inexpensive, have excellent mechanical properties, are easy to process, have low water vapor permeability, and have excellent safety and hygiene properties. Widely used as.

However, when a container made of a polyolefin resin is reused, there is a drawback that a hydrocarbon volatile substance or its oxide is generated due to heat deterioration and the container gives off an offensive odor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to provide a multi-layer molded plastic container,
It is to provide a container that has little odor even when recycled plastic is used.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the present invention is directed to a polyolefin resin layer / adsorbent-containing polyolefin resin layer /
A multilayer plastic container in which a recycled plastic resin layer / a polyolefin resin layer containing an adsorbent is laminated in this order, or a polyolefin resin layer / a recycled plastic resin layer / a polyolefin resin layer containing an adsorbent is laminated in this order. provide. The present invention further provides the following variations regarding the multilayer plastic container formed by stacking as described above. One is a multi-layer plastic container having an adsorbent content of 2000 ppm to 10% by weight. The second is a multilayer plastic container whose adsorbent is natural zeolite. The third is a multi-layer plastic container whose adsorbent is synthetic zeolite. The fourth is a multi-layer plastic container whose adsorbent is silica gel. The fifth is a multi-layer plastic container whose adsorbent is activated carbon. The sixth is a multi-layer plastic container whose adsorbent is activated clay. The seventh is a multi-layer plastic container whose adsorbent is activated aluminum oxide. The eighth is a multi-layer plastic container whose adsorbent is clay. The ninth is a multi-layer plastic container whose adsorbent is diatomaceous earth.

Further details will be described below. The polyolefin used in the present invention is, for example, low density polyethylene,
Polyethylene such as medium-density polyethylene and high-density polyethylene, homopolymer or block copolymer of polypropylene, random copolymer, polybutene, ethylene-α-olefin (having 3 or more carbon atoms) copolymer, etc. are preferably used.

The recycled plastic resin used in the present invention is preferably a polyolefin resin, for example, polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene homo or block polymer or random copolymer, polybutene, Ethylene-α-olefin (having 3 or more carbon atoms) copolymer,
Alternatively, a blended product or the like is preferably used. The history of the material may be unknown, or a mixture of different materials may be used. Further, when the adhesion between the recycled plastic resin layer and the polyolefin-based resin layer is poor, a laminated structure may be formed with an adhesive resin.

The adsorbent used in the present invention mainly has a physical adsorption ability and adsorbs and removes odorous components on the surface of the porous substance. Such adsorbents include natural zeolite, synthetic zeolite, silica gel, activated carbon,
Examples thereof include impregnated activated carbon, activated clay, activated aluminum oxide, clay, diatomaceous earth, kaolin, talc, bentonite, magnesium oxide, iron oxide and aluminum oxide. It is also possible to use a synthetic hydrotalcite-based adsorbent. Further, these adsorbents may be used alone or as a mixture of two or more kinds. From the viewpoint of dispersibility of the adsorbent in the resin, the particle size of the adsorbent is 100
The thickness is preferably not more than μm, and particularly preferably not more than 50 μm. Further, if the adsorbent is added at a high concentration, molding becomes difficult. Therefore, it is desirable that the addition amount be 10% by weight or less based on the resin. Also, due to its function as an adsorbent, 2000 pp
Addition of m or more is desirable. A method in which a masterbatch of the adsorbent is preliminarily molded and then added to the resin is also preferably performed in order to further improve the dispersibility.

One of the important features of the multilayer plastic container according to the present invention is that the polyolefin resin layer containing the adsorbent / the recycled plastic resin layer / the polyolefin resin layer containing the adsorbent are laminated in this order. With the above-mentioned laminated structure, the adsorbent adsorbs the odorous components volatilized from the recycled plastic resin layer, and the container has less odor. When it is desired to prevent the odorous component from migrating on only one side of the container, a polyolefin resin layer / recycled plastic resin layer / a polyolefin resin layer containing an adsorbent are laminated in this order.

The multi-layer structure used in the present invention may include any other resin layer within the above range. It is also possible to stack a barrier resin or a high-gloss resin on the outermost layer to form a high-quality container.

The multi-layer construction of the present invention can be manufactured on a conventional multi-layer plastic molding machine.

[0012]

According to the present invention, an adsorbent-containing polyolefin resin layer / recycled plastic resin layer / adsorbent-containing polyolefin resin layer is laminated in this order, or a polyolefin resin layer / recycled plastic resin layer / By stacking the polyolefin-based resin layers containing the adsorbent in this order, a multilayer plastic container with less odor can be obtained even though recycled plastic is used.

[0013]

【Example】

<Example 1> The laminated structure of the container wall has a high-density polyethylene layer containing 2000 ppm of natural zeolite and having a melt flow rate of 0.60 in order from the outer layer to the inner layer.
A high-density polyethylene layer with a melt flow rate of 0.60 containing a resin layer / 2000 ppm of natural zeolite, which is made from the material obtained by collecting, washing, crushing, melting, and pelletizing the high-density polyethylene container that was used as a solvent can. Blow molding a three-layer parison to a capacity of 1000
I got a bottle of ml. The average wall thickness of this bottle was 0.2 mm / 0.8 mm / 0.2 mm from the outer layer.

<Example 2> The laminated structure of the container wall is such that the synthetic zeolite is 2000 pp in order from the outer layer to the inner layer.
Containing 2000ppm of resin layer / synthetic zeolite made from raw material obtained by collecting, crushing, melting, and pelletizing the high-density polyethylene scraps generated during the production of high-density polyethylene layer / nonwoven fabric with a melt flow rate of 0.60 Blow molding a three-layer parison with a high-density polyethylene layer with a melt flow rate of 0.60
A bottle of 00 ml was obtained. The average wall thickness of this bottle was 0.2 mm / 0.8 mm / 0.2 mm from the outer layer.

<Example 3> A laminated structure of container walls was produced in order from an outer layer to an inner layer in order to produce a high density polyethylene layer / extruded film containing 2000 ppm of silica gel and having a melt flow rate of 0.60. A high-density polyethylene scrap is collected, melted, and pelletized, and a resin layer / silica gel containing 2000 ppm of silica gel and a high-density polyethylene layer with a melt flow rate of 0.60 and a high-density polyethylene layer of three-layer structure are blow molded to obtain a volume of 1000 ml. Got a bottle The average wall thickness of this bottle is 0.2 from the outer layer
It was mm / 0.8 mm / 0.2 mm.

<Embodiment 4> In the laminated structure of the container wall, in order from the outer layer to the inner layer, a high-density polyethylene layer / polyolefin-based plastic bottle containing 2000 ppm of activated carbon and having a melt flow rate of 0.60 was collected.
A parison having a three-layer structure of a resin layer / a high-density polyethylene layer having a melt flow rate of 0.60 and containing 2000 ppm of a resin layer / 2000 ppm of activated carbon, which has been washed, crushed, melted, and pelletized, is blow-molded to obtain a bottle having a capacity of 1000 ml. It was The average wall thickness of this bottle is 0.2 mm / 0.
It was 8 mm / 0.2 mm.

<Embodiment 5> The laminated structure of the container wall is a high density polyethylene layer / solvent can having a melt flow rate of 0.60 containing 2000 ppm of activated clay in order from the outer layer to the inner layer. Blow molding of a three-layer parison composed of a resin layer / a high density polyethylene layer with a melt flow rate of 0.60 containing 2000 ppm of activated clay, which is a raw material obtained by collecting, washing, crushing, melting and pelletizing a container made of high density polyethylene. Capacity 1000ml
Got a bottle of. The average wall thickness of this bottle is 0.
It was 2 mm / 0.8 mm / 0.2 mm.

<Embodiment 6> The laminated structure of the container wall is such that 200 layers of active aluminum oxide are sequentially provided from the outer layer to the inner layer.
High-density polyethylene layer with a melt flow rate of 0.60 containing 0 ppm / high-density polyethylene container that was supposed to be a solvent can, collected, washed, crushed, melted and pelletized resin layer made from raw material / activated aluminum oxide Melt flow rate containing 2000 ppm of 0.6
A three-layer parison of 0 high-density polyethylene layer was blow-molded to obtain a bottle having a capacity of 1000 ml. The average thickness of this bottle is 0.2mm / 0.8mm / 0.2 from the outer layer.
It was mm.

<Embodiment 7> The high-density polyethylene layer / solvent can having a laminated structure of a container wall is a high density polyethylene layer / solvent can having a melt flow rate of 0.60 containing 2000 ppm of clay in order from the outer layer to the inner layer. A resin layer made from a polyethylene container that has been collected, washed, crushed, melted, and pelletized / a high-density polyethylene layer containing 2000 ppm of clay and having a melt flow rate of 0.60
The layered parison was blow molded to give a bottle with a capacity of 1000 ml. The average wall thickness of this bottle is 0.2m from the outer layer
It was m / 0.8 mm / 0.2 mm.

<Embodiment 8> The laminated structure of the container wall is a high density polyethylene layer / solvent can having a melt flow rate of 0.60 containing 2000 ppm of diatomaceous earth in order from the outer layer to the inner layer. Blow molding of a three-layer parison consisting of a resin layer / 2000 ppm of diatomaceous earth with a melt flow rate of 0.60 and a high-density polyethylene layer containing 2000 ppm of diatomaceous earth as a raw material obtained by collecting, washing, crushing, melting, and pelletizing a container made of high-density polyethylene Capacity 100
A 0 ml bottle was obtained. The average wall thickness of this bottle was 0.2 mm / 0.8 mm / 0.2 mm from the outer layer.

<Embodiment 9> The laminated structure of the container wall is used as a high density polyethylene layer / solvent can having a melt flow rate of 0.60 containing 10% by weight of natural zeolite in order from the outer layer to the inner layer. 2000 pp of resin layer / natural zeolite made from recovered, washed, crushed, melted and pelletized high-density polyethylene container
A parison having a three-layer structure of a high density polyethylene layer having a melt flow rate of 0.60 and containing m was blow-molded to obtain a bottle having a capacity of 1000 ml. The average wall thickness of this bottle was 0.2 mm / 0.8 mm / 0.2 mm from the outer layer.

<Embodiment 10> The laminated structure of the container wall has a melt flow rate of 0.60 in order from the outer layer to the inner layer.
High-density polyethylene layer / High-density polyethylene container that was used as a solvent can is collected, washed, crushed, melted,
Resin layer made of pelletized material / melt flow rate containing 2000 ppm of natural zeolite is 0.
A three-layer parison of 60 high-density polyethylene layers was blow-molded to obtain a bottle having a capacity of 1000 ml. The average wall thickness of this bottle is 0.2 mm / 0.8 mm / 0.
It was 2 mm.

<Comparative Example 1> The laminated structure of the container wall has a melt flow rate of 0.60 in order from the outer layer to the inner layer.
High-density polyethylene layer / High-density polyethylene container that was used as a solvent can is collected, washed, crushed, melted,
A parison having a three-layer structure of a resin layer / a high-density polyethylene layer having a melt flow rate of 0.60, which was made from the pelletized material, was blow-molded to obtain a bottle having a capacity of 1000 ml. The average wall thickness of this bottle is 0.2 mm / 0.
It was 8 mm / 0.2 mm.

<Comparative Example 2> The laminated structure of the container wall was such that the natural zeolite was 1000 pp in order from the outer layer to the inner layer.
A high density polyethylene layer with a melt flow rate of 0.60 / a high density polyethylene container used as a solvent can, which was recovered, washed, crushed, melted and pelletized, and the resin layer / natural zeolite was used as a raw material. 2000
A parison having a three-layer structure of a high-density polyethylene layer having a melt flow rate of 0.60 containing ppm was blow-molded to obtain a bottle having a capacity of 1000 ml. The average wall thickness of this bottle was 0.2 mm / 0.8 mm / 0.2 mm from the outer layer.

<Comparative Example 3> The laminated structure of the container wall is used as a high density polyethylene layer / solvent can having a melt flow rate of 0.60 containing 15% by weight of natural zeolite in order from the outer layer to the inner layer. A high-density polyethylene container with a melt flow rate of 0.60 containing 15% by weight of a resin layer / natural zeolite of which high-density polyethylene container is collected, washed, crushed, melted and pelletized Blow molding a parison to a capacity of 10
A bottle of 00 ml was obtained. The average wall thickness of this bottle was 0.2 mm / 0.8 mm / 0.2 mm from the outer layer.

<Comparative Example 3> The laminated structure of the container wall has a melt flow rate of 0.60 in order from the outer layer to the inner layer.
High-density polyethylene layer / High-density polyethylene container that was used as a solvent can is collected, washed, crushed, melted,
Resin layer made from pelletized material / melt flow rate containing 1000 ppm of natural zeolite is 0.
A three-layer parison of 60 high-density polyethylene layers was blow-molded to obtain a bottle having a capacity of 1000 ml. The average wall thickness of this bottle is 0.2 mm / 0.8 mm / 0.
It was 2 mm.

Comparative Example 4 The laminated structure of the container wall has a melt flow rate of 0.60 in order from the outer layer to the inner layer.
High-density polyethylene layer / High-density polyethylene container that was used as a solvent can is collected, washed, crushed, melted,
Resin layer made of pelletized material / melt flow rate of 0.60 containing 15% by weight of natural zeolite
The three-layer parison of the high-density polyethylene layer was subjected to blow molding to obtain a bottle having a capacity of 1000 ml. The average wall thickness of this bottle is 0.2mm / 0.8mm / 0.2m from the outer layer
It was m.

Each sample container was molded and stored at 25 ° C., and the odor inside the container was measured with a gas chromatograph GC-14A (manufactured by Shimadzu Corporation) over time. Table 1 shows the gas odor component removal rates. As for the gas odor component removal rate, the total amount of the detected gas odor component is X, the total amount of the gas odor component of Comparative Example 1 is Y, and the gas odor component removal rate = (Y
It is calculated by −X) / Y × 100.

[0029]

[Table 1]

As is clear from Table 2, the container of the example is a plastic container having less odor than the container of the comparative example.

[0031]

According to the present invention, it is possible to obtain a multi-layer plastic container having little odor, even though recycled plastic is used.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B65D 1/09

Claims (11)

[Claims] 1. A multi-layer plastic container characterized by being laminated in the order of adsorbent-containing polyolefin resin layer / recycled plastic resin layer / adsorbent-containing polyolefin resin layer. 2. A multi-layer plastic container, wherein a polyolefin resin layer / recycled plastic resin layer / a polyolefin resin layer containing an adsorbent are laminated in this order. 3. A multi-layer plastic container according to claim 1, wherein the adsorbent content is 2000 ppm to 10% by weight. 4. A multi-layer plastic container according to claim 1, wherein the adsorbent is natural zeolite. 5. A multi-layer plastic container according to claim 1, wherein the adsorbent is synthetic zeolite. 6. A multi-layer plastic container according to claim 1, wherein the adsorbent is silica gel. 7. A multi-layer plastic container according to claim 1, wherein the adsorbent is activated carbon. 8. A multilayer plastic container according to claim 1, wherein the adsorbent is activated clay. 9. A multi-layer plastic container according to claim 1, wherein the adsorbent is activated aluminum oxide. 10. A multilayer plastic container according to claim 1 or 2, wherein the adsorbent is clay. 11. A multi-layer plastic container according to claim 1, wherein the adsorbent is diatomaceous earth.