JP2001055216A - Plastic multilayer-molded container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded container for contents which should not be oxidized wherein the container is suitable for retort sterilization and cooking in a microwave oven, it has shape retention property, it is inexpensive, light- weighted and excellent in shock resistance and recyclability, and it has a function for trapping oxygen inside a package. SOLUTION: The multilayer-molded container comprises a thermoplastic resin (1) layer; a resin layer which contains an oxygen trapping resin which is a polyester-based with a polyolefin segment having carbon-carbon unsaturated linkage in a molecule coupled, polyamide-based, polyolefin-based or vinyl-based polymer; a thermoplastic resin (2) layer or the thermoplastic resin (1) layer; a resin layer containing the oxygen trapping resin/a gas-barrier resin layer; and the thermoplastic resin (2) layer, which are laminated in this sequence from inner to outer layers. In this case, the container is prepared by vacuum forming, pressure forming, blow molding or injection molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opaque plastic multilayer for accommodating solid or liquid contents which are particularly resistant to oxidation from the viewpoint of quality, and in some cases, contents which need to maintain their shape. Molded containers, especially inexpensive, suitable for food retort sterilization, microwave cooking adaptability, lightweight, excellent in impact resistance and recyclability, can be produced in a wide variety of small quantities, not only gas barrier properties, but also molded The present invention relates to a plastic multilayer molded container having an oxygen trapping function capable of trapping and eliminating oxygen in a container.

[0002]

2. Description of the Related Art Chemicals that are easily oxidized or must not be oxidized, such as medicines, photographic drugs, cosmetic raw materials, and IC manufacturing chemicals, wine, beer, soft drinks, tea,
Beverages or powders that require aroma, such as coffee, or small precision equipment parts that dislike contact with oxygen or the atmosphere,
Conventionally, it is processed as a container made of metal such as glass bottles, iron, copper, or aluminum, or as a plastic molded container as a container for storing objects that do not like to be in contact with air because they are easily oxidized such as easily oxidizable metals and materials. A thermoplastic resin molded container having excellent properties, particularly a multilayer molded container in which a gas barrier resin is laminated on a polyolefin resin or the like and an aluminum foil is laminated depending on the shape, has been used.

[0003] Metal containers made of aluminum, such as aluminum cans, are lightweight and have the advantages of being suitable for sterilizing food retorts, being excellent in recyclability, gas barrier properties, impact resistance, light-shielding properties, and being beautiful. It appears to be a very ideal material for packaging materials that are easily oxidizable or must not be oxidized. On the other hand, raw materials are expensive and require large-scale, high-performance manufacturing facilities, such as facilities for manufacturing airtight aluminum containers and facilities for filling contents, and require extremely large-scale investment. And
It can only deal with small varieties and mass production.
Aluminum containers have poor elasticity, require corrosion-resistant treatment, and are expensive. Also, the containers lack microwave oven adaptability, making it difficult to increase the size. One of the major product concepts is the ability to see the contents as a wrapping material for miscellaneous goods, but this is lacking.Currently, aluminum containers are usually small for liquids and cannot be resealed for beer or soft drinks. Mainly used for containers.

On the other hand, aluminum foil as a container is rarely used alone, and is often laminated with a thermoplastic resin such as a polyolefin resin and used as a laminate film. In addition to having almost all of the advantages, these containers lack the flexibility, but lack the form retention and are difficult to use as multilayer molded containers for contents that require form retention. There is. Further, when oxygen such as air is present in the container after filling, it does not have a function of removing oxygen, and thus there is a problem that it is necessary to dispose an oxygen scavenger in the container. Glass bottles that have long been used as gas barrier containers are excellent in retort sterilization adaptability, microwave oven cooking adaptability, recyclability, gas barrier properties, corrosion resistance, resealability, shape retention, and high-mix low-volume production. It has excellent performance such as being able to produce products at relatively low prices. However, there is no flexibility compared to other packaging materials, so there are restrictions on filling the contents,
Since it has a serious problem that the weight of the packaging material is heavy and the impact resistance is extremely weak, it is mainly used as a container for a conventionally used liquid.

[0005] In addition to the above, there is a paper pack for small articles or as a small packaging container. Since paper alone does not have gas barrier properties, a large number of products coated or laminated with a thermoplastic resin such as aluminum foil and polyolefin resin are on the market. These packaging materials are lightweight, have excellent impact resistance, light-shielding properties, and shape retention, require a small investment in equipment, and can be used for low-volume, high-mix, low-volume production. Lack of adaptability to microwave cooking, lack of adaptability, easy to oxidize contents due to breathability, small shelf life, invisible contents, lack of luxury, etc. ing.

On the other hand, a molded container using a thermoplastic resin, in particular, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyamide, or the like, can easily impart retort sterilization, and is lightweight, impact-resistant, and corrosion-resistant. Excellent processability, adaptability to microwave cooking, low product price, easy adaptation to packaging by automatic packaging line, and low capital investment for these containers. Although it is an excellent packaging material that can handle, these resin molded containers generally have low gas barrier properties, and contents that do not like oxidation in terms of quality, and CO2
Oxygen gas permeability as a container for contents that dislike permeation of ₂ ,
It has a serious drawback of high CO ₂ gas permeability. As a measure for improving the gas barrier property of such a molded container, many plastic multilayer molded containers in which a gas barrier resin is laminated on a structural material resin have been proposed.

[0007] Conventional methods for producing a gas-barrier multilayer molded container include thermoplastic plastics such as polyolefin resin and saponified ethylene-vinyl acetate copolymer (ethylene-vinyl alcohol copolymer; hereinafter referred to as "EVOH").
That. ), A barrier resin such as polyvinylidene chloride or polyacrylonitrile, usually into a laminate sheet by multilayer extrusion using the barrier resin as an intermediate layer, and then subjected to secondary molding to form a multilayer molded container, or Multilayer molded containers have been manufactured by laminating the gas barrier resin alone or by blow molding, injection molding or the like of a structural material resin having the gas barrier resin as an intermediate layer.

The gas-barrier multilayer molded container can greatly improve the gas-barrier property as compared with a single-layer container of a thermoplastic resin such as a polyolefin resin. However, even in a package using such an improved plastic multilayer molded container, the gas barrier resin layer used there has a slight gas permeability, so that it can be stored for a long time and oxygen can be completely eliminated. When oxygen is required, it is inevitable that the oxygen barrier property becomes insufficient as compared with a glass container or a metal can. On the other hand, even in containers such as glass containers and metal cans with excellent gas barrier properties, oxygen in the gas present above the contents after filling the containers cannot be removed, so that oxidation of the contents can be avoided. Without
Contact between the contents and oxygen could not be reliably prevented. Therefore, in order to reliably prevent the contact between the contents and oxygen, not only the gas barrier properties of the multilayer molded container must be perfected, but also the oxygen present inside the molded container must be used in combination with an oxygen scavenger. As this oxygen absorber, an iron compound-based oxygen absorber has been developed, and it has been sealed in a package.

The use of the oxygen absorber requires an atmosphere of high humidity (moisture), and in the presence of carbon dioxide gas, there is a problem that the use is restricted. When used, infants and the like are liable to mistake this for food and eat this oxygen absorber, and this measure is necessary.
Furthermore, since there is no air flow in the molding container, deoxidation with this type of oxygen absorber is localized, and uniform deoxidation in the container cannot be achieved. In order to perform uniform deoxidation, it is necessary to dispose an oxygen absorber throughout the container, and it is necessary to mix the oxygen absorber with the entire container structure resin. In the case of being blended with a resin, there is a problem that a reduction in the tear strength of the resin and a reduction in the resin processability cannot be avoided.

As another means, filling is performed in an atmosphere of nitrogen gas or the like. However, it is difficult to make the entire inside of the molding container zero oxygen, and oxygen from the outside is difficult. Even if the intrusion of oxygen is prevented, it is impossible to remove oxygen (including dissolved oxygen) existing in the container at the time of filling unless a deoxidizer is present. Therefore,
There has been a demand for the development of an inexpensive and easy-to-manufacture plastic multilayer molded container that can safely and reliably remove oxygen in a molded container, completely shut out intrusion from the atmosphere, and be easily manufactured.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a molded container for containing solid or liquid contents which are resistant to oxidation from the viewpoint of quality, which can be sterilized by retort, and is adaptable to microwave cooking and forms. A plastic multilayer of thermoplastic resin that has retention, is inexpensive and lightweight, has excellent impact resistance and recyclability, and can handle even small-scale use, and also has a function of capturing oxygen inside the package. The purpose is to develop molded containers.

[0012]

According to the present invention, there is provided [1] a thermoplastic resin (1) layer / a resin layer containing an oxygen-capturing resin / a thermoplastic resin (2) layer, or a thermoplastic resin from an inner layer to an outer layer. (1) layer / resin layer containing oxygen-supplementary resin / gas barrier resin layer / thermoplastic resin (2) are laminated in this order, and are manufactured by vacuum molding, air pressure molding, blow molding or injection molding. [2] The thermoplastic multi-layer container, wherein the thermoplastic resin is a resin selected from the group consisting of polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, high density polyethylene, medium density polyethylene and polyamide. Multi-layer plastic container described in [3], [3]
The plastic multilayer molding container according to the above [1], wherein the oxygen-scavenging resin is a polyester-based, polyamide-based, polyolefin-based, or vinyl-based polymer having a polyolefin segment having a carbon-carbon unsaturated bond in a molecule, [4] The oxygen-scavenging resin has 5 as a metal atom.
The plastic multilayer molding container according to the above [1], comprising 1 to 15% by weight of a polyolefin oligomer segment having a carbon-carbon unsaturated bond and 85 to 99% by weight of a main polymer segment, containing 0 to 500 ppm of a transition metal compound.

[5] The plastic multilayer molded container according to the above [3], wherein a photo-oxidation accelerator having a sensitizing effect on ultraviolet rays and / or visible rays is blended into the oxygen-scavenging resin layer, [6] oxygen. Polyolefin oligomer segment in the trapping resin, butadiene, norbornene,
Having a molecular weight of 100 containing one of the polymerized oligomer units of dicyclopentadiene and isoprene.
The flexible package according to any one of the above [3] to [5], which is an oligomer segment of 0 to 10,000.

[7] The above-mentioned [3], wherein the polyolefin oligomer segment having a carbon-carbon unsaturated bond in the oxygen-scavenging resin is an oxygen-scavenging resin bonded as a main chain of a main polymer segment or as a branch pendant. To [6], wherein the gas barrier layer is an aluminum foil, an aluminum vapor-deposited film, an alumina vapor-deposited film or a saponified ethylene-vinyl acetate copolymer (EV
OH), polyvinylidene chloride, polyamide, polyxylylenediamine adipamide and polyacrylonitrile. The above object is achieved by developing a plastic multilayer molded container according to the above [1], which is a resin selected from the group consisting of: Achieved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a multi-layered container refers to a multi-layered container formed by extruding a multi-layer sheet by a secondary forming process such as vacuum forming, air pressure forming, multilayer blow molding or injection molding. A multilayer molded container molded by stretching blow of a multilayer preform molded by molding, a multilayer molded container molded by multilayer injection molding or a multi-stage injection molding, etc. The body may be one used in a general closed container, for example, a cap-type lid body such as screwed or fitted, an easy peel aluminum foil laminate, or a multi-layer molding with a filling port and an outlet separately provided. It also includes containers, etc.
Retort sterilization is possible, the container is adapted for microwave cooking as it is after the lid is removed, it is a multilayer molded container having shape retention, and the container body enters the container from the atmosphere In addition to ensuring that oxygen is captured and the amount of invasion to be zero, the oxygen gas in the head space of the container is sometimes supplemented to ensure zero oxygen in the container. As a result, the package using the multilayer molded container has a long shelf life and, unlike a reduced iron-based oxygen scavenger, has no problem in performance even when the moisture is low, and is filled under a nitrogen atmosphere at the time of filling. It is a multilayer molded container that does not need to be used.

The thermoplastic resin (1) or (2) used in the plastic multilayer molded container of the present invention may be transparent or opaque, and may be, for example, a polyolefin resin such as polyethylene or polypropylene. And polyethylene terephthalate (hereinafter referred to as “PET”), polyester resins such as polybutylene terephthalate, polyamide resins such as nylon 6 and nylon 66, polycarbonate, polyacrylonitrile, and the like. When retort treatment at a high temperature is required, it is water-resistant, and depending on the use temperature, it is preferable to use polypropylene, PET, polyethylene naphthalate, polyacrylonitrile or the like having relatively high heat resistance and rigidity.

The oxygen-scavenging resin used in the multilayer molding container of the present invention is a polyester, polyamide, polyolefin or vinyl polymer having a polyolefin oligomer segment having a carbon-carbon unsaturated bond in the molecule. Can be mentioned. These are in principle opaque resins. Here, examples of the polyester-based polymer include polyethylene terephthalate (hereinafter, referred to as “PET”) and polybutylene terephthalate (hereinafter, referred to as “PBT”). As the polyamide polymer, nylon 6, nylon 6
6, aromatic polyamides such as nylon 12 and aromatic polyamides such as polyxylylenediamine adipamide (MXD6). Among them, MXD6 is a suitable resin as a material resin for a barrier package because the resin itself has gas barrier properties.

For example, the polyester or polyamide as the oxygen-scavenging resin in the present invention is prepared by using an olefin oligomer having two functional groups at one end as a part of the raw material compound during the synthesis of the polymer. The polymer may be condensed, or the polymer may be reacted with an olefin oligomer having two functional groups at one end, and an olefin oligomer segment may be introduced by transesterification or transamidation. Further, at the time of polymer synthesis, a free functional group may be provided in the main chain using a raw material having three or more functional groups, and an olefin oligomer segment may be bonded to the free functional group. A transesterification or transamidation reaction may be carried out by reacting a starting material compound having the above functional group to introduce a functional group into the main chain, to which an olefin oligomer segment may be bonded.

In the polyester polymer having such a pendant olefin oligomer segment, a part of the dibasic carboxylic acid is replaced with an olefin oligomer having two carboxyl groups at one end in the polymer synthesis stage, or A part of the glycol is replaced with an olefin oligomer having two hydroxyl groups at one end to carry out a polycondensation reaction to obtain a polyester having the olefin oligomer in a pendant form. A part of the dibasic carboxylic acid is replaced with a trivalent or higher polyhydric carboxylic acid, or a part of the glycol is replaced with a trivalent or higher polyhydric alcohol, and copolycondensed to form a carboxyl group or a hydroxyl group functional group. It is provided in the middle of the main chain, to which an olefin oligomer is bonded.

Alternatively, an olefin oligomer having two carboxyl groups or two hydroxyl groups at one end may be transesterified with a normal polyester polymer to directly introduce an olefin oligomer segment, or a trivalent carboxylic acid, Preferably, an aromatic carboxylic acid is reacted, or a trihydric or higher polyhydric alcohol is reacted, and a free carboxyl group or a free hydroxyl group functional group is introduced into the polyester main chain by transesterification, and the functional group is added. May be combined with an olefin oligomer.

Similarly, in the case of polyamide, a method of copolycondensing an olefin oligomer having two carboxyl groups at one end or an olefin oligomer having two amino groups at one end at the time of polymer synthesis; A method of directly introducing the olefin oligomer by transamide reaction of the olefin oligomer, replacing a part of the dibasic carboxylic acid with a trivalent or higher polycarboxylic acid, or replacing a part of the alkylenediamine with a trivalent or higher carboxylic acid. A method in which a functional group of a carboxyl group or an amine group is provided in the middle of the main chain by replacing with an alkylene polyamine and copolycondensed, and an olefin oligomer segment is introduced. The transhydric alcohol reacts with the Introducing a functional group, to which there is a method of bonding the olefin oligomer segments.

The polycondensation polymer containing the olefin oligomer in the form of a block has a functional group capable of polycondensation at both terminals as a part of a raw material such as diamine, dicarboxylic acid or glycol during synthesis. By using an olefin oligomer having a carbon-carbon unsaturated bond and a molecular weight of 1,000 to 10,000, an olefin oligomer having a polyamide-based polycondensation-based polymer segment constituting the majority and a carbon-carbon unsaturated bond constituting a small portion A polycondensation polymer such as polyamide having segments bonded to the main chain in a block shape can be used. That is, in the synthesis of the above polyamide, carboxyl group at both ends, amino group, in some cases has a hydroxyl group,
Molecular weight of 1000 to 100 having carbon-carbon unsaturated bond
The olefin oligomer segment of No. 00 can be produced by mixing and reacting a dicarboxylic acid, which is a raw material of polyamide, with a diamine (a nylon salt is also acceptable) or a lactam.

Further, the polyamide has a small molecular weight of 10 or more, which has an amino group, a hydroxyl group or a carboxyl group at both ends and has a carbon-carbon unsaturated bond.
By mixing olefin oligomers of 00 to 10000,
By performing a transamidation or transesterification reaction while melting, a polycondensation polymer having a polyolefin oligomer segment in the main chain of polyester or polyamide can be produced.

The olefin oligomer derivative used in the polycondensation reaction needs to have a carbon-carbon unsaturated bond in the olefin oligomer segment chain. Such oligomers include butadiene derivatives having a conjugated double bond such as butadiene and isoprene, and homo-oligomers and copolymers of non-conjugated dienes such as norbornene and dicyclopentadiene, and copolymers of these diene compounds with olefins such as ethylene and propylene. Polymerized oligomers can be mentioned. For these oligomers, it is necessary to introduce a functional group having a reactivity with a functional group bonded to the polycondensation polymer main chain. For this purpose, an oligomer containing a diene compound is formed by metathesis polymerization or anion living polymerization. Can be synthesized by introducing a functional group into the compound.

Further, in the present invention, the addition polymer segment of the oxygen-permeable addition-polymerized linear polymer having a reactive functional group (hereinafter referred to as the reactive functional group (1)) is a polyolefin-based or vinyl-based polymer. If there is no particular limitation, ethylene, propylene, butene
Polyolefin resins such as 1,4-methylpentene-1 or other olefin homopolymers, copolymers or copolymers with vinyl monomers, styrene resins such as polystyrene homopolymers or copolymers, (meth) acrylic acid, The backbone is an acrylic copolymer containing (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate, and addition polymers of various polymers such as acrylonitrile and vinyl chloride. Polymer segments may be mentioned. Among them, a polymer segment which has a high oxygen permeability, is thermally stable and has excellent resin processability, or a material whose physical properties are close to required, is selected according to the purpose of use, and is preferably a polymer segment to which an oligomer can be easily bonded. Oxygen permeability is low in barrier properties of a polymer having a low oxygen scavenging property, and has a high degree of oxygen barrier properties like the oxygen scavenging polymer of the present invention, but as an oxygen scavenging polymer, its ability is low and insufficient. Become.

As a polymer for providing these segments, for example, a polymer having no reactive functional group (1), such as polyethylene, polypropylene, and polystyrene, may be used. A graft polymer obtained by graft polymerization of maleic acid or (meth) acrylic acid, or an ethylene- (meth) acrylic acid copolymer, an ethylene-glycidyl methacrylate copolymer, an ethylene-ethyl acrylate-maleic anhydride copolymer, Reactive functional groups such as styrene-glycidyl methacrylate copolymer, ethylene- or styrene-2-hydroxyethyl methacrylate copolymer (1)
And a polymer obtained by copolymerizing a monomer having the following formula: Further, a method of imparting a reactive functional group (1) to the addition polymer by modifying the addition polymer by hydrolysis or the like after copolymerizing vinyl acetate, acrylic acid ester or the like may be employed.

The reactive functional group (1) need not be limited in relation to the functional group of the olefin oligomer to be reacted therewith (hereinafter referred to as the reactive functional group (2)). Taking into account ease, stability, reactivity and the like, a carboxyl group, a hydroxyl group, an epoxy group, a carboxylic anhydride group or an amino group is preferred. When the reactive functional group (1) is a carboxyl group, the reactive functional group (2) of the olefin oligomer is selected from a hydroxyl group, an amino group, an epoxy group, an isocyanate group, and the like having reactivity with the functional group. The same applies to other cases.

When the olefin oligomer segment is introduced into the addition polymer, it is most effective to have an addition polymer having a reactive functional group (1) and a carbon-carbon unsaturated bond having a reactive functional group (2). The olefin oligomer is melt-kneaded using an apparatus capable of melt-kneading such as an extruder and a blender. Alternatively, the two may be reacted in the form of a solution. However, not only an organic solvent or the like is required, but also the solvent must be recovered later, which is troublesome and costly. Furthermore, EVO
Even in a vinyl-based polymer having a functional group itself, such as a vinyl-based copolymer containing H and (meth) acrylic acid as one component, an olefin oligomer segment can be introduced in the same manner as the polyolefin-based polymer. . In addition, the polymer itself may have an olefin oligomer segment, such as a butadiene-styrene copolymer and an acrylonitrile-butadiene-styrene copolymer.

As the oxygen-scavenging resin, oxygen is trapped in an olefin oligomer segment having a carbon-carbon unsaturated bond active for oxygen. At this time, α-activated by the carbon-carbon unsaturated bond The reaction is initiated by abstraction of the hydrogen bonded to the carbon at the position, and eventually the carbon chain is cleaved from this part. Therefore, a polymer having an olefin oligomer segment in the main chain undergoes main chain cleavage. On the other hand, in a polymer in which olefin oligomer segments are bonded in a pendant form, the problem is only the cleavage of the pendant olefin oligomer segments, and the main chain having a large effect on physical properties is not affected at all even if oxygen is trapped. become. In consideration of physical properties, a pendant-bound oxygen-scavenging resin is more preferable.

In a polyolefin or vinyl polymer, the molecular weight of the olefin oligomer segment is determined by the transparency of the oxygen-scavenging resin, the type of the main constituent compound of the oxygen-scavenging resin, the introduction of the oligomer segment into the main chain, or It depends on the form of introduction, such as whether it is introduced in a pendant form, the type of compound constituting the oligomer, the average number of oligomer segments introduced into one molecule of the oxygen-scavenging resin, the number of carbon-carbon unsaturated bonds in the oligomer, etc. Although an appropriate value cannot be obtained, the molecular weight may be small when the number of the introduced oligomer segments is large, and the molecular weight tends to be large when the number of the introduced oligomer segments is small. Less than about 5 and if transparency is required, butadiene oligomer As oligomer molecular weight 1,000 to
About 0000 can be used. In the case of a butadiene-styrene resin, an acrylonitrile-butadiene-styrene resin or the like, it is sufficient that the amount of butadiene required for the properties of the resin is copolymerized.

Since such an oxygen-scavenging resin alone has low reactivity with oxygen as it is, it is necessary to add a catalytic amount of a transition metal compound to the resin in order to increase the reactivity. Suitable transition metal compounds include manganese, cobalt, nickel, copper, rhodium, ruthenium, and the like, most preferably cobalt. Preferred counter ions of these metals include chloride ion, acetate ion, sterate ion, palmitate ion, 2-ethylhexanoate ion, neodecanoate ion, naphthenate ion and the like, but are not limited thereto. Absent. Particularly preferred are cobalt 2-ethylhexanoate and cobalt neodecanoate. Alternatively, the transition metal compound may be an ionomer, which are well known in the art. The amount of the transition metal compound is in the range of 0.001 to 1%, preferably 0.01 to 03% of the weight of the oxygen-scavenging resin as a metal. Below this lower limit, the effect of accelerating the reaction is not recognized, and 1%
The effect is saturated and the reaction rate with oxygen is not increased even if it is added in excess of the above, but merely causes a decrease in physical properties and an increase in cost.

It is preferable to add a photo-oxidation accelerator (sensitizer) to the oxygen-scavenging resin layer in addition to the transition metal compound. Benzophenone, o-
Methoxybenzophenone, acetophenone, o-methoxyacetophenone, acenaphthenequinone, methyl ethyl ketone, valerophenone, hexanophenone, α-phenylbutyrophenone, p-morpholinopropiophenone, dibenzosuberone, 4-morpholinobenzophenone, benzoin, benzoin methyl ether, etc. It can be used but is not limited to this.

This photo-oxidation accelerator enhances the oxygen-scavenging rate of the oxygen-scavenging resin by exposure to light.
It varies depending on the type of oxygen-scavenging resin, wavelength and intensity of light, and the like. If the transparency of the resin is low, it is necessary to increase the amount of the photo-oxidation accelerator used. Usually, it is about 0.01 to 10% by weight, preferably about 0.1 to 1% by weight, based on the whole resin composition. The transition metal compound and the photo-oxidation accelerator are described in detail in JP-A-5-194949.

Such an oxygen-scavenging resin may be used alone, or may be diluted with another resin for cost reduction. The type of resin to be diluted is preferably a polyester resin such as PET if it is a polyester-based oxygen-scavenging resin, and the same type of resin such as polypropylene is highly compatible if it is a polyolefin-based oxygen-scavenging resin. This is preferable because it has a high possibility of becoming transparent. In this case, the blending amount of the oxygen-scavenging resin is also related to the thickness of the oxygen-scavenging resin layer, but it is possible to use an oxygen-scavenging resin having a concentration of at least 5%, preferably 20% or more. Other methods for activating the oxygen scavenging property of the oxygen scavenging resin include electron beam, γ
Irradiation such as X-rays and X-rays, and external energy such as ultrasonic waves for applying α-hydrogen extraction energy, high frequency, and heat (high temperature) are also effective. Oxygen supplementation rate,
The amount of oxygen supplement can be increased. In the case of a resin having a small oxygen permeability of the polycondensation-based linear polymer itself serving as the base material, the amount of oxygen permeating through the polycondensation-type oxygen-scavenging polymer layer is extremely small, so that the amount dissolved in the polymer is also small. Because the dissolved oxygen is completely trapped in the polymer layer, the performance as a gas barrier resin is stronger than the apparent oxygen trapping polymer. Among them, it was found that, for example, in MXD6 having a low oxygen permeability, the gas barrier property was remarkably improved so that the oxygen permeability could not be detected (although the oxygen scavenging property was slightly recognized).

Although the gas barrier layer of the present multilayer molded container is not an essential requirement, the provision of the gas barrier layer makes it easier to maintain the oxygen-resistant barrier properties of the multilayer molded container for a long period of time. The gas barrier layer is a multilayer formed by laminating outside or aluminum foil aluminum deposited film providing a gas barrier resin layer of oxygen supplemental resin layer, and SiO _X evaporation film or alumina-deposited film on the outside of the oxygen supplemental resin layer It has the effect of extending the oxygen supplement life of the container. As the gas barrier resin, a thermoplastic resin having a low oxygen permeability coefficient and being thermoformable is used. For example, EVOH, polyvinylidene chloride, MXD6, polyacrylonitrile, PETI (copolymer of ethylene glycol and terephthalic acid, isophthalic acid), PEN and the like can be mentioned. Among them, EVOH is most suitable in terms of the balance between oxygen barrier properties and cost. For example, an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%, is saponified so that the degree of saponification becomes 96 mol% or more, particularly 99 mol% or more. The resulting saponified copolymer is preferred. The EVOH should have a molecular weight sufficient to form a film and is generally at least 0.01 dl / g, especially at least 0.05 dl / g as measured at 30 ° C. in a mixed solvent of phenol: water at a weight ratio of 85:15. / G or more.

Another example of a gas barrier resin having the above-mentioned properties is MXD6. Although this resin does not have a high oxygen barrier property, it has a property that an adhesive is not necessary in laminating with PET or the like because it is a polyamide resin, and this polyamide should also have a molecular weight enough to form a film, 1.0 dl in concentrated sulfuric acid
/ G and a relative viscosity (η) measured at a temperature of 30 ° C.
_rel ) is preferably 1.1 or more, especially 1.5 or more. In the present invention, the gas barrier resin used as the intermediate layer is not particularly limited as long as it has a high gas barrier property against oxygen and carbon dioxide and can be thermoformed. As such a gas barrier resin,
The most suitable resin in view of the balance between performance and cost is EVOH.

Other examples of the gas barrier resin having the above-mentioned properties include polyvinylidene chloride, polyacrylonitrile, and the number of amide groups per 100 carbon atoms of 5 to 5
Polyamides and polyester copolymers in the range of 0, especially 6 to 20 can be used. These gas barrier resins also preferably have a molecular weight sufficient to form a film. For polyamide, 1.0 dl /
g at a temperature of 30 ° C. (η
_rel ) is preferably 1.1 or more, especially 1.5 or more. In the present invention, among the above gas barrier resins, EVOH, MXD6 and PETI are preferred.

[0038]

The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

(Raw material resin for producing oxygen-scavenging resin) [PEN] Nippon Unipet Co., Ltd., Unipet NS763: Intrinsic viscosity IV = 0.70 2. [PENT8] Unipet NS663 manufactured by Nippon Unipet Co., Ltd .: Intrinsic viscosity IV = 0.72 PEN / PET = 92 mol% / 8 mol% 3. [PETN8] Unipet NS553 manufactured by Nippon Unipet Co., Ltd .: intrinsic viscosity IV = 0.82, PEN / PET = 8 mol% / 92 mol% [PET] Nippon Unipet Co., Ltd., Unipet RT543: intrinsic viscosity IV = 0.75 5. [MXD6] MX Nylon 6007 manufactured by Mitsui Gas Chemical Co., Ltd .: relative viscosity = 2.7, melt index = 2 g / 10 min (measuring temperature = 260 ° C., load = 2160 g) [PA6] Novamit 1020, manufactured by Mitsubishi Gas Chemical Co., Ltd., relative viscosity 2.0,

7. [EVOH (44)] EVAL EP-E105, manufactured by Kuraray Co., Ltd .: ethylene copolymer ratio = 44 mol%, melting point = 165 ° C., melt index = 5.5 g / 10 min, (measurement temperature = 260 ° C.,
Load = 2160g) 8. [EVOH (32)] EVAL EP-F101 manufactured by Kuraray Co., Ltd .: ethylene copolymer ratio = 32 mol%, melting point = 183 ° C., melt index = 1.3 g / 10 min, (measurement temperature = 260 ° C.,
Load = 2160g) 9. [MAH-PP] Adtex ER-32 manufactured by Japan Polyolefin Co., Ltd.
0P-MP10. [ET-184M] Ethylene terpolymer Co. Adtex ET-18, manufactured by Japan Polyolefin Co., Ltd.
4-M

(Production of polyester oxygen scavenging resin)
In the production of the oxygen-capturing resin of the present invention, a co-axial twin-screw extruder manufactured by Toshiba Machine Co., Ltd. (TEM37BS,
37 mmφ, L / D = 45). 1) Block copolymer [Polyester-based oxygen-scavenging resin- (PE-)] 96 parts by weight of PET (Unipet RT543, intrinsic viscosity IV = 0.75) as a basic resin in a hopper. Introduced from. The resin temperature was set to 280 ° C, and 200 parts by weight of cobalt stearate, based on the total amount of the base resin and the hydroxyl group butadiene oligomer at both ends, was added to 4 parts by weight of a liquid compound having both ends of the hydroxyl group butadiene oligomer (RHT45 manufactured by Elphatochem Co., Ltd., Mw = 2800). Using a liquid injector, 4 parts by weight of the mixture was introduced into an extruder, melt-kneaded for a residence time of about 5 minutes, and transesterified. Then, unreacted substances and low-molecular substances were removed from the vacuum vent. This was extruded, and the molten strand was rapidly cooled and cut in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. Further, the pellets were sufficiently crystallized in a vacuum dryer at a temperature of 120 ° C. for 2 hours, and then dried at 150 ° C. for 4 hours. After confirming that the water content was 0.005% by weight or less, the pellets were used for subsequent molding. .

[Polyester-based oxygen-scavenging resin- (P
E-)] 92 parts by weight of PET (manufactured by Nippon Unipet Co., Ltd., Unipet NS553, intrinsic viscosity IV = 0.82) were introduced from a hopper. The resin temperature was set to 260 ° C., and 8 parts by weight of a liquid butadiene oligomer having hydroxyl groups at both ends (RLM20, manufactured by Elphatochem), 200 ppm of cobalt stearate based on the total amount of the base resin and the butadiene oligomer having hydroxyl groups at both ends were added to 200 parts by weight. Using a liquid injector, 8 parts by weight of the mixture was introduced into an extruder, melt-kneaded for a residence time of about 5 minutes, and transesterified. Then, unreacted substances and low molecular substances were removed from a vacuum vent. . Next, the molten strand is rapidly cooled and cut in water,
Pellets were used. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. Further, the pellets were sufficiently crystallized in a vacuum dryer at a temperature of 120 ° C. for 2 hours, and then dried at 150 ° C. for 4 hours to obtain a moisture content of 0.005% by weight.
After confirming the following, it was used for subsequent molding.

[Polyester-based oxygen-scavenging resin- (P
E-)] As a basic resin, PET (Unipet RT543 manufactured by Nippon Unipet Co., Ltd., intrinsic viscosity IV = 0.
75) 88 parts by weight were introduced from the hopper. The resin temperature was set to 280 ° C., and both ends of the hydroxyl group octadiene oligomer (an octadiene oligomer was synthesized from octadiene by metathesis polymerization, and both ends were replaced with hydroxyl groups by hydrolysis. Mw = 2000) 12 parts by weight of liquid material A mixture of 200 ppm of cobalt stearate and 200 ppm of benzophenone, based on the total amount of the base resin and the octadiene oligomer at both ends, was introduced into the extruder using a liquid injector, and the residence time was about 5 minutes. Esterification, unreacted substances and low molecular weight substances were removed from the vacuum vent. Next, the molten strand is quenched in water,
Cut to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. Further, the pellet was sufficiently crystallized in a vacuum dryer at a temperature of 120 ° C. for 2 hours, and then dried at 150 ° C. for 4 hours to obtain a water content of 0.0
After confirming that the content was not more than 05% by weight, it was used for subsequent molding.

2) Graft copolymer [Polyester-based oxygen-scavenging resin- (PE-)] 96 parts by weight of PET (Unipet RT543, intrinsic viscosity IV = 0.75) manufactured by Nippon Unipet Co., Ltd. Was introduced from the hopper. The resin temperature is set to 280 ° C., butadiene oligomer having two hydroxyl groups at one end (butadiene is subjected to ordinary anionic living polymerization,
By using epichlorohydrin for the termination reaction and further hydrolyzing, a butadiene oligomer having two hydroxyl groups at one end was obtained. This time, the one with a molecular weight of 5000 was prepared. ) A mixture of 200 ppm of cobalt stearate with respect to the total amount of the base resin and the hydroxyl group-butadiene oligomer at one end in 4 parts by weight of the liquid material was introduced into the extruder using a liquid injection machine, and the mixture was melt-kneaded for a residence time of about 5 minutes. After unreacted substances and low molecular substances were removed from the vacuum vent, the molten strand was quenched in water and cut to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. Further, the pellet was sufficiently crystallized in a vacuum dryer at a temperature of 120 ° C. for 2 hours.
After drying at 50 ° C. for 4 hours, it was confirmed that the water content was 0.005% by weight or less, and used for subsequent molding.

[Polyester-based oxygen-scavenging resin- <P
E-)] PEN as a basic resin (Unipet NS763, manufactured by Nippon Unipet Co., Ltd., intrinsic viscosity IV = 0.
70) A mixture of 99 parts by weight and 1 part by weight of glycerin was melt-kneaded at 290 ° C. to obtain a modified PEN. This modified PEN was used in the following reactions. The above modified PE
92 parts by weight of N were introduced from the hopper. Resin temperature 2
Set to 90 ° C., one-terminal epoxy group butadiene oligomer (butadiene is subjected to ordinary anionic living polymerization,
By using epichlorohydrin for the termination reaction, a butadiene oligomer having an epoxy group at one end was obtained. In this case, a material having a molecular weight of 10,000 was prepared. ) 8 parts by weight of a mixture of 200 ppm of cobalt stearate with respect to the total amount of the base resin and the one-terminal epoxy group butadiene oligomer was introduced into the extruder using a liquid injection machine. Different, the second after the base resin is melted
Although it is preferable to introduce it from the supply port, it may be introduced from the hopper by dry blending with the basic resin. Then, the mixture was melt-kneaded for a residence time of about 5 minutes to carry out a reaction. After removing the unreacted products and low molecular weight substances from the vacuum vent, the molten strand was rapidly cooled and cut in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. Further, the pellets were sufficiently crystallized at a temperature of 120 ° C. for 2 hours in a vacuum dryer, and then dried at 150 ° C. for 4 hours.
After confirming that the water content was 0.005% by weight or less, it was used for the following molding.

[Polyester-based oxygen-scavenging resin- (P
E-)] PENT8 (Unipet NS663, manufactured by Nippon Unipet Co., Ltd., basic viscosity IV = 0.
72) 88 parts by weight were introduced from the hopper. The resin temperature was set to 280 ° C., and a norbornene oligomer having two hydroxyl groups at one end (a norbornene oligomer was synthesized by the above-described metathesis polymerization, and then one end was modified to two hydroxyl groups to obtain a hydroxyl group norbornene oligomer In this case, the one having a molecular weight of 10,000 was prepared.)
Cobalt stearate was added in an amount of 200 parts by weight based on the total amount of the base resin and the one-terminal hydroxyl group norbornene oligomer.
ppm of norbornene oligomer is introduced into the extruder (different from the basic resin and the supply hopper, it is preferable to introduce the basic resin from the second supply port after melting, but it is dry blended with the basic resin and introduced from the hopper. Then, the mixture is melted and kneaded for a residence time of about 5 minutes to carry out a reaction, and after removing unreacted substances and low molecular substances from a vacuum vent,
The molten strand was quenched in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. Further, the pellet was sufficiently crystallized in a vacuum dryer at a temperature of 120 ° C. for 2 hours.
For 4 hours, and was confirmed to have a water content of 0.005% by weight or less, and used for subsequent molding.

(Production of polyamide-based oxygen-scavenging resin) 1) Block copolymer [Polyamide-based oxygen-scavenging resin-(PA-)] nylon MXD6 (manufactured by Mitsubishi Gas Chemical Company, Inc., MX nylon 6)
007, 94 parts by weight having a relative viscosity of 2.7) were introduced from a hopper. The melting temperature of the resin was set to 280 ° C., and a carboxyl group at both ends was butadiene oligomer (normal anion living polymerization was carried out using butadiene. A carbonic acid gas was used in the termination reaction, and the molecular weight was 2,000 in this case.) In 6 parts by weight of the liquid material, 200 ppm of cobalt stearate was added based on the total amount of the base resin and the carboxyl group butadiene oligomer. The mixture was introduced into an extruder using a liquid injector, and the mixture was melt-kneaded for a residence time of about 5 minutes to carry out a reaction. Unreacted substances and low-molecular substances were removed from a vacuum vent, and then the molten strand was dissolved in water. And quenched to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. The pellets were further dried in a vacuum dryer at a temperature of 80 ° C. for 6 hours, and it was confirmed that the moisture content was 0.05% by weight or less. MXD6 nylon copolymer produced as described above during molding: 50 parts by weight and MX
Nylon 6007: What was dry blended with 50 parts by weight was used.

[Polyamide-based oxygen-scavenging resin- (PA
−)] Nylon MXD6 (Mitsubishi Gas Chemical Co., Ltd., M
96 parts by weight of X nylon 6007, relative viscosity 2.7),
Introduced from the hopper. Set the resin temperature to 280 ° C,
A dicyclopentadiene oligomer having amino groups at both terminals (a dicyclopentadiene oligomer synthesized by the above-described metathesis polymerization and having both terminal groups substituted with amino groups. The molecular weight was 1000 in this case) was added to 4 parts by weight of a liquid material.
Cobalt stearate was added in an amount of 200 based on the total amount of the basic resin and the dicyclopentadiene oligomer having amino groups at both terminals.
ppm was introduced into the extruder using a liquid injector, and the mixture was melt-kneaded for a residence time of about 5 minutes to carry out the reaction. After the unreacted substances and low-molecular substances were removed from the vacuum vent, the molten strand was removed. It was rapidly cooled in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. The pellets are further dried at a temperature of 8 in a vacuum dryer.
After drying at 0 ° C. for 6 hours, it was confirmed that the water content was 0.05% by weight or less, and used for subsequent molding.

[Polyamide-based oxygen-scavenging resin- (PA
-)] Nylon 6 (manufactured by Mitsubishi Gas Chemical Company, Novamid 1020, relative viscosity 2.0) 92 as a basic resin
Parts by weight were introduced from the hopper. The resin temperature was set to 260 ° C., and a normal anionic living polymerization was carried out using a butadiene oligomer having a carboxyl group at both terminals (butadiene was used. In addition, a carbonic acid gas was used in the termination reaction, and the molecular weight was 2,000 in this case.) 8 parts by weight of the liquid material, 200 ppm of cobalt stearate with respect to the total amount of the base resin and the butadiene oligomer at both terminal carboxyl groups. The mixture was introduced into the extruder using a liquid injector, and the mixture was melt-kneaded for a residence time of about 5 minutes to carry out the reaction. Unreacted substances and low-molecular substances were removed from the vacuum vent, and then the molten strand was removed. It was rapidly cooled in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. Further, the pellets were dried in a vacuum dryer at a temperature of 80 ° C. for 6 hours, and confirmed that the water content was 0.05% by weight or less.
It was used for subsequent molding.

2) Graft copolymer [Polyamide-based oxygen-scavenging resin- (PA-)] nylon MXD6 (manufactured by Mitsubishi Gas Chemical Company, Inc., MX nylon 6)
007, relative viscosity 2.7) 96 parts by weight were introduced from a hopper. A resin temperature is set to 260 ° C., butadiene oligomer having two carboxyl groups at one end (butadiene is subjected to ordinary anionic living polymerization, maleic acid dimethyl ester is used for termination reaction, and further hydrolysis is carried out. A butadiene oligomer having two carboxyl groups at one end was obtained.
Created. A) A mixture of 200 ppm of cobalt stearate with respect to the total amount of the base resin and the carboxyl group-butadiene oligomer at one end in 4 parts by weight of the liquid material was introduced into the extruder using a liquid injector, and the residence time was about 5 hours. The mixture was melt-kneaded for minutes. After unreacted substances and low molecular substances were removed from the vacuum vent, the molten strand was quenched in water to obtain pellets. Until a pellet was obtained from the molten strand, the embedding was performed under a nitrogen atmosphere. The pellets were further dried in a vacuum dryer at a temperature of 80 ° C. for 6 hours. After confirming that the water content was 0.05% by weight or less, the pellets were used for subsequent molding.

[Polyamide-based oxygen-scavenging resin (PA)
1)] Nylon MXD6 (Mitsubishi Gas Chemical Co., Ltd., M
X nylon 6007, relative viscosity 2.7) 99 parts by weight,
One part by weight of alkylenetriamine was added to
A melt-kneading reaction was performed at 90 ° C. to obtain a modified MXD6.

Next, this basic resin = modified MXD6 was added to 92
It was introduced from a weight hopper. The temperature of the resin is set at 290 ° C., butadiene oligomer having one end epoxy group (butadiene is subjected to ordinary anionic living polymerization,
By using epichlorohydrin for the termination reaction, a butadiene oligomer having one end epoxy group was obtained. This time, the one with a molecular weight of 2,000 was created. ) 200 parts by weight of cobalt stearate was added to 8 parts by weight of the liquid material, based on the total amount of the base resin and the one-terminal epoxy group butadiene oligomer.
pm is introduced into the extruder using a liquid injector, melt-kneaded for a residence time of about 5 minutes, unreacted substances and low molecular substances are removed from the vacuum vent, and the molten strand is quenched in water. , And cut to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. The pellets are further dried in a vacuum dryer at a temperature of 80 ° C. for 6 hours.
After drying for a time, it was confirmed that the water content was 0.05% by weight or less, and the product was used for subsequent molding.

(Production of EVOH-based acid-scavenging resin) [EVOH-based oxygen-scavenging resin- (EV-)] Ethylene-vinyl alcohol copolymer resin (Kuraray Co., Ltd., EP-E105, ethylene content) as a basic resin 44
Mol%, MI = 5.5, melting point: 165 ° C.) were fed from a 96 parts by weight hopper. The resin temperature was set at 185 ° C., butadiene oligomer having one terminal epoxy group (butadiene was subjected to ordinary anion living polymerization, and epichlorohydrin was used for termination reaction to obtain a butadiene oligomer having one terminal epoxy group. A mixture prepared by mixing 200 parts by weight of cobalt stearate with respect to the total amount of the base resin and the one-terminal epoxy group butadiene oligomer in 4 parts by weight of the liquid was introduced into the extruder using a liquid injector. Unreacted substances and low molecular weight substances were removed from the vacuum vent by melt kneading for a residence time of about 5 minutes, and then the molten strand was quenched in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. The pellets were further dried in a vacuum dryer at a temperature of 60 ° C. for 6 hours. After confirming that the water content was 0.05% by weight or less, the pellets were used for subsequent molding.

[EVOH-based oxygen-scavenging resin- (EV-
)] Ethylene-vinyl alcohol copolymer resin (manufactured by Kuraray Co., Ltd., EP-F101, ethylene content 32 mol%, MI = 1.3, melting point 183 ° C.) as a basic resin 9
2 parts by weight were introduced from the hopper. The melting temperature of the resin is 2
Set to 00 ° C, one-terminal epoxy group butadiene oligomer (butadiene is subjected to ordinary anionic living polymerization,
By using epichlorohydrin for the termination reaction, a butadiene oligomer having an epoxy group at one end was obtained. This time, the one with a molecular weight of 5000 was prepared. A) A mixture of 200 ppm of cobalt stearate with respect to the total amount of the base resin and the one-terminal epoxy group butadiene oligomer in 8 parts by weight of the liquid material was introduced into the extruder using a liquid injector,
Unreacted substances and low molecular weight substances were removed from the vacuum vent by melt kneading for a residence time of about 5 minutes, and then the molten strand was quenched in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. The pellets were further dried in a vacuum dryer at a temperature of 60 ° C. for 6 hours. After confirming that the water content was 0.05% by weight or less, the pellets were used for subsequent molding.

(Production of polyolefin-based oxygen-scavenging resin) [Polyolefin-based oxygen-scavenging resin-(PO-)]
Maleic anhydride-modified polypropylene resin (manufactured by Nippon Polyolefin Co., Ltd., ER-350P-M) as a basic resin
P, maleic anhydride content 1.0% by weight, MI = 8
0) 92 parts by weight were introduced from the hopper. The melting temperature of the resin is set at 185 ° C, butadiene hydroxyl group oligomer at one end (butadiene is subjected to ordinary anionic living polymerization, and ethylene oxide is used for termination reaction.
One-terminal hydroxyl group butadiene oligomer was obtained. This time, the one with a molecular weight of 5000 was prepared. ) A mixture of 200 parts by weight of cobalt stearate based on the total amount of the base resin and the one-terminal epoxy group butadiene oligomer in 8 parts by weight of the liquid material was introduced into the extruder using a liquid injector, and the residence time was about 5 hours. Melted and kneaded for minutes. After removing unreacted substances and low molecular substances from the vacuum vent, the molten strand was quenched in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. The pellets were further dried in a vacuum dryer at a temperature of 60 ° C. for 6 hours. After confirming that the water content was 0.05% by weight or less, the pellets were used for subsequent molding.

[Polyolefin-based oxygen-scavenging resin-
(PO-)] maleic anhydride-modified polyethylene resin (manufactured by Nippon Polyolefin Co., Ltd., ET-184M, maleic anhydride content 2.5% by weight, MI = 10);
It was introduced from an 8 parts by weight hopper. The melting temperature of the resin is 18
The temperature was set at 5 ° C., and a hydroxyl group-butadiene oligomer having one end was obtained by subjecting butadiene to ordinary anionic living polymerization and using ethylene oxide for termination reaction. This time, a molecular weight of 5000 was obtained.
Created. A) A mixture of 200 ppm of cobalt stearate with respect to the total amount of the base resin and the one-terminal epoxy group butadiene oligomer in 12 parts by weight of the liquid material was introduced into the extruder using a liquid injector, and the residence time was about 5 hours. Melted and kneaded for minutes. After removing unreacted substances and low molecular substances from the vacuum vent, the molten strand was quenched in water to obtain pellets. The treatment was performed under a nitrogen atmosphere until pellets were obtained from the molten strand. The pellets were further dried in a vacuum drier at a temperature of 60 ° C. for 6 hours to obtain a water content of 0.05%.
After confirming that it was less than 10% by weight, it was used for subsequent molding. Table 1 shows an outline of the production conditions and the configuration of the oxygen-scavenging resin.

[0057]

[Table 1]

* 1: PE = polyester, PA = polyamide, EV = EVOH, PO = polyolefin * 2: PBD = polybutadiene * 3: POD = polyoctadiene * 4: PNB = polynorbornene * 5: PDCPD = Polydicyclopentadiene

(Thermoplastic resin) Polypropylene (PP) manufactured by Nippon Polyolefin Co., Ltd., Sun Allomer, PM76
1A Polybutylene terephthalate resin (PBT) Teijin Ltd., PBT (C7000), density = 1.
31 Polystyrene (PS) Styron (GP grade, glass transition temperature 100 ° C), manufactured by Asahi Kasei Corporation Polyethylene (PE) Jenolex HDP, manufactured by Japan Polyolefin Co., Ltd.
E KM870A Density = 0.955 g / cm ³

(Barrier Resin) MXD-6-2, manufactured by Toyobo Co., Ltd., OSM film: MI = 2 g / 10
MXD6-2 manufactured by Toyobo Co., Ltd., OSM film Melt index = 2 g / 10 minutes (260 ° C., load = 2160 g)
2160 g) EVOH film The EVOH (44) was formed into a T-die film at a resin temperature of 190 ° C. to obtain a film having a thickness of 20 μm. EVOH film The EVOH (32) was formed into a T-die film at a resin temperature of 195 ° C to obtain a film having a thickness of 20 µm. Aluminum foil A foil having a thickness of 20 μm manufactured by Showa Aluminum Co., Ltd. was used. Polyacrylonitrile Film A film having a thickness of 20 μm from Hytron BX manufactured by Tamapoly Corporation was used.

(Examples 1 to 16) From the inner layer to the outer layer, a laminate having the basic structure of thermoplastic resin (1) layer / oxygen-supplementary resin layer (/ gas barrier resin layer) / thermoplastic resin (2) layer Table 2 shows the resin composition and thickness of each layer. The laminate was subjected to dry lamination using a urethane-type adhesive for a sheet of each layer. The obtained multilayer sheet was vacuum-formed to form a nearly cylindrical container having a diameter of 7 cm and a volume of 80 cc.

[0062]

[Table 2]

(Comparative Examples 1 to 16) From the inner layer to the outer layer, in the thermoplastic resin (1) layer / oxygen capturing resin layer (/ gas barrier resin layer) / thermoplastic resin (2) layer, Table 3 shows the layer structure in which the resin was replaced with another oxygen-capturing inner resin, and the contents and thickness of the layer structure were shown in Table 3. The laminate was molded in the same manner as in the example, and a container having a similar size was molded.

[0064]

[Table 3]

(Evaluation Method) Examples 1 to 16 and Comparative Example 1
A laminate (four-sided pouch: 150 mm × 200 mm) was manufactured by heat-sealing the laminated films manufactured in Nos. To 16 and two sheets thereof together with a heat seal layer.
This pouch was filled with 400 ml of nitrogen, and gas barrier properties were measured at 23 ° C. by the following method. The results are shown in Tables 3 and 5.

1) Oxygen permeability The oxygen permeability was OX-TRAN2 / 20M manufactured by Mocon.
Due to L, the inner surface has an oxygen concentration (mm
Hg) It was determined under the measurement conditions of 65% RH. 2) Oxygen concentration in the pouch Change in oxygen concentration in the pouch after nitrogen replacement After filling 400 ml of nitrogen into the pouch manufactured as described above, the pouch was stored in a room controlled at 23 ° C., and the oxygen concentration in the pouch was changed over time. It was measured. The oxygen concentration at the start of the measurement was 0.70%. Changes in the residual oxygen concentration in the pouch after filling with air.
After filling, the outer surface was heat-sealed with an aluminum foil composite laminate to ensure isolation from the outside air. 23 ℃
And the oxygen concentration in the pouch was measured over time. Oxygen concentration at start is 21.0
%Met. Tables 4 and 5 show these results.

[0067]

[Table 4]

[0068]

[Table 5]

[0069]

The multilayer molded container of the present invention is obtained by laminating a thermoplastic resin layer / a resin layer containing an oxygen-scavenging resin / a thermoplastic resin layer in this order from the inside. Instead, the wall is a plastic multilayer molded container capable of capturing oxygen inside the multilayer molded container and eliminating it. In particular, since oxygen scavenging is performed over the entire wall surface of the multilayer molded container, when compared with the conventional oxygen-resistant multilayer molded container in which the oxygen absorber is enclosed, deoxidation is not localized but over the entire multilayer molded container. An effect to be performed uniformly is exhibited. Further, when a multilayer molded container is formed by laminating a thermoplastic resin layer / a resin layer containing an oxygen-supplementing resin / a gas barrier resin layer / a thermoplastic resin layer in this order, not only does oxygen inside the multilayer molded container disappear, but also externally. The amount of oxygen gas permeating from the container can be greatly reduced, so even if the oxygen capturing capacity of the multilayer molded container is the same, the efficacy maintenance period increases, and the long-term oxygen abundance inside the plastic multilayer molded container becomes zero. Time will be secured. In particular, the multilayer molded container has a long shelf life because there is no influence of oxygen on the contents, does not use an oxygen scavenger, so there is no need for moisture inside the container, and there is no need for a nitrogen gas atmosphere when filling. In addition to such features, it can sterilize retort required for foods, especially cooked foods, etc.It also has the feature that microwave lid cooking adaptability is also possible by removing the lid This is a multilayer molded container having excellent features not found in plastic multilayer molded containers for food packaging.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hirotaka Tagoshi 1-1-1 Onodai, Midori-ku, Chiba-shi, Chiba F-term in Showa Denko KK (reference) 3E033 BA09 BA13 BA15 BA16 BA18 BA19 BA21 BA22 BA23 BB04 BB08 CA03 CA16 GA01 GA02 GA03 4F100 AA02B AA36B AB10D AB33D AK01A AK01C AK01D AK02B AK03B AK05A AK05C AK07A AK07C AK12A AK12C AK16D AK27D AK28B AK29B AK41B AK41K AK42A AK42C AK46A AK46B AK46C AK46D AK51G AK69D AL04B BA03 BA04 BA07 BA10A BA15 CA09B CA30B CB00 DA01 EH66D GB16 JB16A JB16C JC00 JD02D JD14 JD14B JK10 JL02 JL03 JL04 JL16

Claims (8)

[Claims] 1. From the inner layer to the outer layer, a thermoplastic resin (1) layer / a resin layer containing an oxygen-capturing resin / a thermoplastic resin (2)
Layers, or thermoplastic resin (1) layer / resin layer containing oxygen-supplementary resin / gas barrier resin layer / thermoplastic resin (2) layer, and are laminated in this order. Vacuum molding, air pressure molding, blow molding or injection molding A multi-layer plastic container manufactured by the following method. 2. The plastic multilayer molded container according to claim 1, wherein the thermoplastic resin is a resin selected from the group consisting of polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, high density polyethylene, medium density polyethylene, and polyamide. . 3. The plastic according to claim 1, wherein the oxygen-scavenging resin is a polyester-based, polyamide-based, polyolefin-based or vinyl-based polymer having a polyolefin segment having a carbon-carbon unsaturated bond in the molecule. Multi-layer molded container. 4. An oxygen-scavenging resin having a metal atom of 50
Containing 1 to 500 ppm of a transition metal compound
The plastic multilayer molded container according to claim 1, comprising 5% by weight of a polyolefin oligomer segment having a carbon-carbon unsaturated bond and 85 to 99% by weight of a main polymer segment. 5. The plastic multilayer molded container according to claim 3, wherein a photo-oxidation accelerator having a sensitizing effect on ultraviolet light and / or visible light is added to the oxygen-scavenging resin layer. 6. The polyolefin oligomer segment in the oxygen-scavenging resin is an oligomer segment having a molecular weight of 1,000 to 10,000, including one of polymerized oligomer units of butadiene, norbornene, dicyclopentadiene and isoprene. Item 3
6. The flexible package according to any one of items 5 to 5. 7. The oxygen-scavenging resin in which the polyolefin oligomer segment having a carbon-carbon unsaturated bond in the oxygen-scavenging resin is bonded as a main chain of the main polymer segment or as a branched pendant.
7. The plastic multilayer molded container according to any one of items 6 to 6. 8. A gas barrier layer comprising an aluminum foil, an aluminum vapor-deposited film, an alumina vapor-deposited film or a saponified ethylene-vinyl acetate copolymer (EVOH);
The plastic multilayer molded container according to claim 1, wherein the resin is a resin selected from the group consisting of polyvinylidene chloride, polyamide, polyxylylenediamine adipamide and polyacrylonitrile.