JPH0647880A - Multilayered plastic structure - Google Patents

Abstract

PURPOSE:To provide a molded product having excellent capacity and falling impact resistance as a plastic structure having gloss, esp., excellent falling impact resistance and appearance when the ground matter of a container is used. CONSTITUTION:A multilayered plastic structure is constituted of at least three layers of a polyester resin layer, an adhesive resin layer and a polyolefinic resin layer and characterized by that at least one or more layer of the polyolefinic resin layer contains an ethylene/alpha-olefin copolymer or is composed of this copolymer alone or contains an propylene/alpha-olefin copolymer or is composed of this copolymer alone and has the polyester resin layer as the outermost layer. Or, further, a scrap layer is provided in addn. to those layers and an ethylene/alpha-olefin copolymer or a propylene/alpha-olefin copolymer is added to the scrap layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic structure having a multi-layer structure, and more specifically to a multi-layer blow molding container, multi-layer sheet or multi-layer film formed of a polyester resin and a polyolefin resin. It can be used for containers such as bottles and cups, and packaging materials.

[0002]

2. Description of the Related Art Plastic containers having a multi-layered structure have been known in the past, but when such a container has a resin layer other than polyolefin, especially when a pulverized product of this container is added to one layer. The physical properties such as drop impact at a low temperature were remarkably deteriorated, which was not satisfactory in practical use.

[0003]

The present invention has been made to solve the problems of the prior art as described above, and has excellent performance as a glossy plastic structure,
It is intended to provide a molded article having a drop impact resistance, particularly a drop impact resistance when a pulverized product of the present container is used, and an appearance.

[0004]

SUMMARY OF THE INVENTION The inventors of the present invention have conducted various researches and experiments in view of the above-mentioned drawbacks, for example, Japanese Patent Application No. 4-2090.
Inventing an adhesive resin of a polyester resin and a polyolefin resin as seen in No. 2, and further adding a pulverized product composed of this container, that is, a recycled product, to one layer,
In order to prevent the physical properties of the container from being remarkably deteriorated when it is reduced, it has been found that one or more layers can be added with a component improving the impact resistance to solve various drawbacks. It came to completion. The present invention comprises a resin composition of at least three layers of a polyester resin layer, an adhesive resin layer, and a polyolefin resin layer, and one or more of the polyolefin resin layers is an ethylene / α-olefin copolymer. It is a multi-layer plastic structure having a polyester resin layer, which is contained or is a simple substance of ethylene / α-olefin copolymer, as the outermost layer. The multi-layered plastic structure also includes a structure in which a layer formed by crushing the above-mentioned multi-layered plastic structure is added. The crushed layer of the multi-layered plastic structure contains an ethylene / α-olefin copolymer.

Further, the resin composition has at least three layers of a polyester resin layer, an adhesive resin layer, and a polyolefin resin layer, and one or more of the polyolefin resin layers are propylene / α-olefin copolymers. Or a polyester resin layer which is a simple substance of a propylene / α-olefin copolymer as the outermost layer. The multi-layered plastic structure also includes a structure in which a layer formed by crushing the above-mentioned multi-layered plastic structure is added. The crushed layer of the multi-layered plastic structure contains a propylene / α-olefin copolymer.

Further, the present invention is the above-mentioned multilayer plastic structure, which is a multilayer blow-molded article in which the outer surface layer is a polyester resin and the inner layer is a polyolefin resin.

[0007]

DETAILED DESCRIPTION The multilayer plastic structure in the present invention may be a sheet-like material or a molded product thereof. Alternatively, the parison having these layer configurations may be laminated and extruded, and the container may be hollow blow-molded by using compressed air.

The polyester resin used for the outer layer comprises a copolymer of polybasic acid and polyhydric alcohol. As such a polybasic acid, one containing terephthalic acid as a main component is preferable, and as a polyhydric alcohol, one containing ethylene glycol as a main component is preferable. The polybasic acid and the polyhydric alcohol may each include another polybasic acid and another polyhydric alcohol as a comonomer component.

Other polybasic acids that can be contained in the polybasic acid as a comonomer component include polybasic acids such as isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid and diphenyletherdicarboxylic acid.

Other polyhydric alcohols that can be contained as a comonomer component in the polyhydric alcohol include trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentylene glycol, diethylene glycol, 1,4.
-Polyhydric alcohol components such as cyclohexane dimethylol can be used.

Examples of the adhesive resin include glycidyl group-containing resins such as glycidyl methacrylate resin and ethylene / glycidyl methacrylate copolymer resin, ethylene / α-olefin copolymer, ethylene / α-olefin phthalic anhydride copolymer and the like. Resins and mixtures of these resins can be used.

As the innermost layer, a general polyolefin resin, that is, a polyethylene resin, a polypropylene resin, a polymethylpentene resin, an ethylene vinyl acetate copolymer or the like is added to an ethylene / α-olefin copolymer or a propylene / α-olefin copolymer. Addition of polymer, or ethylene / α-olefin copolymer or propylene / α-
A simple substance of an olefin copolymer can be used.

As the recycled material layer of the multi-layered plastic structure, top flash and bottom flash generated during molding are crushed, and ethylene / α-
An olefin copolymer or a propylene / α-olefin copolymer may be added alone or in a mixture with a virgin resin to form a recycled material layer. The recycled material layer is provided between the adhesive resin and the innermost layer.

[0014]

The multi-layered plastic structure of the present invention contains an α-olefin in one or more layers of the multi-layered structure, that is, the innermost layer and / or the layer containing the recycled material of the molded article. By adding a polymer, the drop impact resistance at low temperature can be improved, and the polyester resin layer provided as the outermost layer can provide a glossy multilayer plastic structure.

[0015]

【Example】

<Example 1> Using a multi-layer blow molding machine having four screw extruders, a screw A was made of an amorphous polyester resin, and a screw B was made of ethylene / α-olefin / maleic anhydride as an adhesive resin layer. Polymer resin, screw C, ethylene-α-olefin copolymer,
A resin prepared by mixing high-density polyethylene and recycled scrap material of the multilayer plastic according to the present example in a weight ratio of 10:30:60 is supplied, a high-density polyethylene resin is supplied to the screw D, and plasticized and extruded under the following conditions. , An amorphous polyester resin, an adhesive resin, a resin containing recycled material, and a high-density polyethylene resin are sequentially laminated from the outer layer surface through a blow head to form a laminated parison, and the parison has a cylindrical bottle-shaped cavity. After sandwiching in the blow mold and cutting the upper part of the parison, blow molding was performed using compressed air. The obtained bottle had good gloss and appearance, and had no problems with physical properties such as drop impact at low temperature. The average thickness of the bottle body is 0.18 mm for the polyester resin layer and 0.11 m for the adhesive resin layer.
m, recycle agent layer 0.57 mm, innermost layer 0.12 mm
Met.

Screw diameter Barrel temperature Screw A 30 mmφ 220 ° C. Screw B 25 mmφ 180 ° C. Screw C 50 mmφ 220 ° C. Screw D 30 mmφ 180 ° C. Head --210 ° C.

Example 2 Using a multi-layer blow molding machine having four screw extruders, screw A was made of non-crystalline polyester resin, and clew B was made of ethylene / α-olefin / anhydrous as an adhesive resin layer. A maleic acid copolymer resin, a screw C, a high-density polyethylene resin, and a resin obtained by mixing a recycled scrap material of the multilayer plastic according to the present embodiment in a weight ratio of 40:60 are supplied, and a screw D is supplied with ethylene / α-. A resin obtained by mixing an olefin copolymer and a high-density polyethylene resin in a weight ratio of 20:80 was supplied, and the mixture was plasticized and extruded under the following conditions, and a non-crystalline polyester resin, an adhesive resin, from the outer layer surface through a blow head, A resin containing recycled material and a resin containing high-density polyethylene resin are sequentially laminated to form a laminated parison,
The parison was inserted into a blow mold having a cylindrical bottle-shaped cavity, the upper part of the parison was cut, and then blow molding was performed using compressed air.

Screw diameter Barrel temperature Screw A 30 mmφ 220 ° C. Screw B 25 mmφ 180 ° C. Screw C 50 mmφ 220 ° C. Screw D 30 mmφ 180 ° C. Head --210 ° C.

The obtained bottle has a polyester resin layer /
Adhesive resin layer / recycle layer / innermost layer = 2: 1: 6: 1
The average total thickness was 1.05 mm, the glossiness and appearance were good, and there were no problems with physical properties such as drop impact at low temperature.

Example 3 Using a multi-layer blow molding machine having four screw extruders, screw A was made of non-crystalline polyester resin, and clew B was made of ethylene / α-olefin / anhydrous as an adhesive resin layer. Maleic acid copolymer resin, screw C, propylene / α-olefin copolymer, polypropylene (block copolymer)
A resin, a recycled scrap material of the multilayer plastic according to the present embodiment, was mixed at a weight ratio of 20:30:50, and a screw D was supplied with a propylene / α-olefin copolymer resin and a polypropylene (block copolymer) resin. A resin mixed in a weight ratio of 50:50 is supplied, plasticized and extruded under the following conditions, and an amorphous polyester resin, an adhesive resin, a resin containing a recycled material, a polypropylene (block copolymer) from the outer layer surface through a blow head.
Resins containing resin are sequentially laminated to form a laminated parison,
The parison was inserted into a blow mold having a cylindrical bottle-shaped cavity, the upper part of the parison was cut, and then blow molding was performed using compressed air.

Screw diameter Barrel temperature Screw A 30 mmφ 220 ° C. Screw B 25 mmφ 180 ° C. Screw C 50 mmφ 220 ° C. Screw D 30 mmφ 200 ° C. Head --210 ° C.

The obtained bottle has a polyester resin layer /
Adhesive resin layer / recycle layer / innermost layer = 3: 1: 4: 2
The average total thickness was 0.9 mm, the glossiness and appearance were both good, and there were no problems with various physical properties such as drop impact at low temperatures.

<Comparative Example 1> Using the multilayer blow molding machine and mold used in Example 1, the screw A is made of an amorphous polyester resin, and the clew B is made of ethylene / α-olefin / anhydrous as an adhesive resin layer. Maleic acid copolymer resin, high-density polyethylene for screw C, recycled scrap material of multi-layer plastic according to this embodiment: 50:
The resin mixed at a 50 weight ratio was supplied, the high-density polyethylene resin was supplied to the screw D, and plasticized and extruded under the following conditions, and the amorphous polyester resin, the adhesive resin, and the A resin containing recycled material and a high-density polyethylene resin were sequentially laminated to form a laminated parison, the parison was sandwiched in a blow mold, the upper part of the parison was cut, and blow molding was performed using compressed air. The obtained bottle had good gloss and appearance. The average thickness of the bottle body is 0.2 polyester resin layer
The thickness was 0 mm, the adhesive resin layer was 0.13 mm, the recycle agent layer was 0.60 mm, and the innermost layer was 0.14 mm.

Screw diameter Barrel temperature Screw A 30 mmφ 220 ° C. Screw B 25 mmφ 180 ° C. Screw C 50 mmφ 220 ° C. Screw D 30 mmφ 180 ° C. Head --210 ° C.

Comparative Example 2 Using a multi-layer blow molding machine having four screw extruders, the screw A was made of an amorphous polyester resin, and the clew B was made of ethylene / α-olefin / anhydrous as an adhesive resin layer. A maleic acid copolymer resin, a screw C, a polypropylene (block copolymer) resin, and a resin in which a recycled scrap material of the multilayer plastic according to the present embodiment is mixed at a 50:50 weight ratio are supplied, and a screw D is polypropylene ( Block copolymer) resin is supplied, plasticized and extruded under the following conditions, and an amorphous polyester resin, an adhesive resin, a resin containing recycled material, and a polypropylene (block copolymer) resin are sequentially laminated from the outer layer surface through a blow head. To form a laminated parison, which is then shaped into a cylindrical bottle-shaped cavity. Scissors blow molds having, after cutting the parison top were blown using compressed air.

Screw diameter Barrel temperature Screw A 30 mmφ 220 ° C. Screw B 25 mmφ 180 ° C. Screw C 50 mmφ 220 ° C. Screw D 30 mmφ 200 ° C. Head --210 ° C.

The obtained bottle has a polyester resin layer /
Adhesive resin layer / recycle layer / innermost layer = 3: 1: 4: 2
The average total thickness was 0.93 mm, and both the glossiness and the appearance were good. The physical properties of the obtained bottle are shown below.

[0028] Note) Gloss is based on JIS Z8741 60 degree specular gloss. Drop strength n = 10, each sample 10 times, 1.2m
Drop 5 ° C.

[0029]

According to the present invention, a multi-layered plastic structure having excellent physical properties such as appearance, surface gloss, and drop impact at low temperature can be obtained. Further, with the constitution of the present invention, a multilayer plastic structure having sufficient drop impact resistance can be obtained even if the recycled material of the multilayer plastic structure is used.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location B29L 22:00 4F (72) Inventor Shunichi Kato 1-5-1, Taito, Taito-ku, Tokyo Toppan stamp Imprint Co., Ltd. (72) Inventor Yusuke Terauchi 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (5)

[Claims] 1. A resin composition comprising at least three layers of a polyester resin layer, an adhesive resin layer, and a polyolefin resin layer, and one or more of the polyolefin resin layers are ethylene / α-olefin copolymers. A multi-layered plastic structure having a polyester resin layer as an outermost layer, the polyester resin layer containing, or a simple substance of an ethylene / α-olefin copolymer. 2. A polyester resin layer, an adhesive resin layer, a layer made of a pulverized product of the above-mentioned multilayer plastic structure, and a polyolefin resin layer having at least four resin constitutions, and a layer made of the pulverized product. 2. The multilayer plastic structure according to claim 1, which has a polyester resin layer as an outermost layer, which comprises an ethylene / α-olefin copolymer. 3. A resin composition comprising at least three layers of a polyester resin layer, an adhesive resin layer, and a polyolefin resin layer, one or more of the polyolefin resin layers being a propylene / α-olefin copolymer. A multi-layered plastic structure having a polyester resin layer as an outermost layer, which is a simple substance of propylene / α-olefin copolymer. 4. A polyester resin layer, an adhesive resin layer, a layer formed from a pulverized product of the multilayer plastic structure, and
4. A polyester resin layer having at least four resin layers of a polyolefin resin layer, wherein the layer formed of the pulverized material contains a propylene / α-olefin copolymer as an outermost layer. Multi-layer plastic structure. 5. The multi-layer plastic structure according to claim 1, wherein the multi-layer plastic structure is a multi-layer blow-molded product having an outer surface layer made of a polyester resin and an inner layer made of a polyolefin resin. object.