JPH0460826B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a plastic multilayer container that has excellent oxygen permeation resistance under conditions where moisture and heat act, and more specifically relates to a plastic multilayer container that has excellent oxygen permeation resistance during heat sterilization and subsequent aging. This invention relates to a plastic multilayer container with excellent properties. (Prior art) Conventional packaging containers include metal cans, glass bottles,
Various types of plastic containers are used, and plastic containers are used for various purposes because of their light weight, impact resistance, and cost. However, in metal cans and glass bottles, oxygen permeation through the container wall is zero, whereas in the case of plastic containers, oxygen permeation through the container wall occurs on a non-negligible level, which affects the shelf life of the contents. is becoming a problem. In order to prevent this, plastic containers have a multilayer wall structure, and at least one of the layers is made of a resin having oxygen permeability such as ethylene-vinyl alcohol copolymer. Oxygen scavengers have been used for a long time to remove oxygen inside containers, and an example of applying this to container walls is the invention disclosed in Japanese Patent Publication No. 1824/1983, which states: A layer made of an oxygen permeable resin mixed with an oxygen scavenger whose main ingredient is a reducing substance, and a layer with oxygen gas barrier properties are laminated,
Multilayer structure for packaging. (Problems to be Solved by the Invention) In the prior art described above, the oxygen scavenger present in the container wall absorbs oxygen within the container and maintains the interior of the container in a highly anoxic state. Packaging containers of this type generally still have the problem that under conditions of simultaneous moisture and heat, ie, heat sterilization conditions, oxygen within the container cannot be suppressed to low levels. Generally, oxygen barrier resins such as ethylene-vinyl alcohol copolymers have hygroscopic properties,
Moreover, it has the property that the oxygen permeability coefficient increases due to moisture absorption. For this reason, a multilayer structure is generally adopted in which an intermediate layer is made of oxygen barrier resin and inner and outer layers are made of moisture-resistant resin such as olefin resin on both sides. Therefore, it is recognized that moisture permeation occurs through the olefin resin layer, and the amount of oxygen in the container increases due to an increase in oxygen gas permeability due to moisture absorption in the oxygen barrier resin layer and an increase in oxygen permeability due to a rise in temperature. It will be done. Therefore, an object of the present invention is to solve the above-mentioned problems in conventional plastic multilayer containers, to suppress the permeation of oxygen through the container wall to a small level even under conditions where moisture and heat act simultaneously, and to improve the structure of the container. An object of the present invention is to provide a plastic multilayer container capable of reducing the amount of oxygen inside the container. (Means for Solving the Problems) According to the present invention, the oxygen permeability coefficient at 20°C and 0% RH is 10 ^-12 cc・cm/cm ²・sec・cmHg or less, and at 20°C and 100% RH. A laminated structure in which the intermediate layer is a resin composition in which a gas barrier thermoplastic resin with a moisture adsorption amount of 0.5% or more is blended with an oxygen scavenger, and a moisture-resistant thermoplastic resin layer is provided on both sides of the intermediate layer. A plastic multi-layer container is provided comprising: According to the present invention, a gas barrier thermoplastic resin having an oxygen permeability coefficient of 10 ^-12 cc·cm/cm ² ·sec.cmHg or less at 20°C and 0% RH is used in the first intermediate layer and at 20°C. A second intermediate layer is made of a hygroscopic thermoplastic resin with a moisture adsorption amount of 0.5% or more at 100% RH and an oxygen scavenger, and a moisture-resistant thermoplastic resin is coated on both sides of the intermediate layer. A plastic multilayer container is provided which is characterized in that it consists of a laminated structure with layers. (Function) In the plastic multilayer container of the present invention, a gas barrier resin is used as an intermediate layer, and a layer of moisture-resistant resin is provided on both sides of the intermediate layer, as in the conventional one. The feature is that an oxygen scavenger is blended into the gas barrier resin. Oxygen scavengers generally have reducing properties and scavenge oxygen by being oxidized by oxygen, but the presence of moisture is essential for this oxidation reaction, that is, scavenging oxygen. . In the present invention, the fact that oxygen barrier resins are generally highly hygroscopic is skillfully utilized, and the moisture captured by the oxygen barrier resin's moisture absorption is effectively used to promote oxidation of the oxygen scavenger. It is something. In the plastic multilayer container of the present invention, under normal conditions, the gas barrier resin layer as an intermediate layer serves to prevent oxygen from permeating, that is, to block oxygen, but moisture and heat act simultaneously as in heat sterilization. Under such conditions, the oxygen scavenger present in the gas barrier resin layer effectively serves to block oxygen, and the functions are shared effectively depending on the condition in which the container is placed. That is, as already pointed out, under conditions where moisture and heat act simultaneously, moisture permeation occurs significantly through the moisture-resistant resin layer, and the gas barrier resin loses its original oxygen content due to moisture absorption and further temperature rise. Although this will reduce the barrier performance, the absorbed moisture activates the oxygen scavenger and the oxygen scavenger effectively captures oxygen, resulting in less oxygen permeation during heat sterilization. It is suppressed. Considering its original purpose, the gas barrier resin used in the present invention has an oxygen permeability coefficient of 10 ^-12 cc・cm/cm ²・sec・cmHg or less at 20°C and 0%RH;
In particular, it should be less than 5×10 ^-13 cc·cm/cm ² ·sec·cmHg. According to the first embodiment of the invention, if a single intermediate layer is used, the gas barrier resin should have a moisture adsorption of 0.5% or more, especially 1.0% or more at 20° C. and 100% RH. If the amount of water adsorption is smaller than the above range, the oxygen scavenging ability of the oxygen scavenger tends to decrease. In the layer of the gas barrier resin composition containing an oxygen scavenger used in the present invention, when the moisture content or temperature in the layer is high, oxygen blocking by the oxygen scavenger acts effectively, and when the moisture content or temperature is low. In this state, the gas barrier resin acts as an oxygen barrier. In the plastic multilayer container of the present invention, two or more intermediate layers can be used. According to another aspect of the present invention, the intermediate layer is a plurality of functionally separated layers. That is, one intermediate resin layer is made of a gas barrier resin having the above-mentioned oxygen permeability coefficient, the other intermediate resin layer is a hygroscopic resin layer having the above-mentioned water adsorption amount, and the latter layer is compounded with an oxygen scavenger. do. In this case, it goes without saying that the oxygen barrier resin layer can be formed into a plurality of layers, one layer containing an oxygen scavenger, and the other layer containing no oxygen scavenger. (Preferred Embodiment of the Invention) In FIG. 1 showing an example of the multilayer structure of the container of the present invention, the container wall 1 has an oxygen scavenger-containing gas barrier resin intermediate layer 2 and the necessary layers on both sides of the intermediate layer 2. It consists of an inner layer 4 and an outer layer 5 of moisture-resistant resin, which are provided with adhesive layers 3a and 3b in between, depending on the requirements. In FIG. 2 showing another example of the multilayer structure of the container, the container wall 1 includes a gas barrier resin layer 2a containing no oxygen scavenger and a hygroscopic resin layer 2 containing an oxygen scavenger.
b, with an adhesive layer 3b interposed therebetween as necessary, and an inner layer 4 and an outer layer of moisture-resistant resin on both sides of these intermediate layers, optionally interposed adhesive layers 3a and 3c. 5 is provided. As the oxygen absorber used in the present invention, any oxygen absorber conventionally used for this type of application can be used, but in general, it is preferable to use one that is reducing and is substantially insoluble in water. is a metal powder with reducing properties, such as reducing iron, reducing zinc,
Reducible tin powder; low-level metal oxides, such as FeO,
Fe ₃ O ₄ , reducing metal compounds such as iron carbide, iron silicon, iron carbonyl, ferrous hydroxide, etc. or a combination thereof as a main component,
These include alkali metal, alkaline earth metal hydroxides, carbonates, sulfites, thiosulfates, tertiary phosphates, diphosphates, organic acid salts,
It can be used in combination with halides and also with auxiliaries such as activated carbon, activated alumina, activated clay. Alternatively, a polymer compound having a polyhydric phenol in its skeleton, such as a polyhydric phenol-containing phenol aldehyde resin, etc. may be mentioned. These oxygen scavengers generally have an average particle size of 100 μm or less, especially 50 μm.
It is preferable to have a particle size of not more than m. As the gas barrier resin, a thermoplastic resin that has the aforementioned oxygen permeability coefficient and hygroscopicity and is thermoformable is used. The most suitable example of the gas barrier resin is an ethylene-vinyl alcohol copolymer, such as an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%. The degree of saponification of the polymer
A saponified copolymer obtained by saponification to a content of 96 mol % or more, especially 99 mol % or more is used. This saponified ethylene vinyl alcohol copolymer should have a molecular weight sufficient to form a film, and is generally 0.01 as measured at 30°C in a phenol:water mixed solvent of 85:15 by weight.
It is desirable to have a viscosity of dl/g or more, particularly 0.05 dl/g or more. In addition, other examples of gas barrier resins having the above characteristics include polyamides having the number of amide groups per 100 carbon atoms in the range of 5 to 50, particularly 6 to 20; for example, nylon 6, nylon 6,
6, nylon 6/6,6 copolymer, metaxylylene adipamide, nylon 6,10, nylon 11, nylon 12, nylon 13, etc. are used. These polyamides should also have a molecular weight sufficient to form a film, with a relative viscosity [ηrel] of 1.1 measured at a concentration of 1.0 g/dl in concentrated sulfuric acid and at a temperature of 30°C.
It is particularly desirable that the value is 1.5 or more. Oxygen scavenger: 1 to 1 per gas barrier resin
It is preferred to use a concentration of 1000% by weight, especially 5 to 200% by weight. When the content of the oxygen scavenger is lower than the above range, the amount of oxygen permeated during heat sterilization tends to be larger than when it is within the above range,
On the other hand, if the amount exceeds the above range, the amount of oxygen permeation under normal conditions tends to be larger than that within the above range. In addition, the oxygen scavenger-containing gas barrier resin layer generally has a thickness of 5 to 200 μm, although it differs depending on the amount of oxygen that can be dissolved in the container.
It is desirable to have a thickness of 10 to 120 μm. On the other hand, when using a combination of a gas barrier resin intermediate layer that does not contain an oxygen scavenger and a hygroscopic resin intermediate layer that contains an oxygen scavenger, the gas barrier resin layer that does not contain an oxygen scavenger is It may be a gas barrier resin layer, or it may be a gas barrier resin with low hygroscopicity such as a vinylidene chloride copolymer resin, a high nitrile resin, or a gas barrier polyester resin. On the other hand, it goes without saying that the hygroscopic resin containing the oxygen scavenger may also have gas barrier properties, such as the hygroscopic gas barrier resin exemplified above, but for example, polyacrylic acid Other hygroscopic thermoplastic resins can also be used, such as polymethacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyvinyl methyl ether, and vinyl alcohol-acrylic acid copolymers. The blending amount of the oxygen scavenger in the hygroscopic resin may be within the range described for the gas barrier resin, and both resin layers have the above-mentioned total thickness, and the thickness of the layer containing the oxygen scavenger and the layer not containing the oxygen scavenger is within the range described for the gas barrier resin. Preferably, the ratio is within the range of 95:5 to 5:95, particularly 75:25 to 25:75. In the present invention, ASTM
Thermoplastic resins with a water absorption of less than 0.5%, especially less than 0.1%, as measured by D570, are used, typical examples of which are low-, medium- or high-density polyethylene,
Isotactic polypropylene, ethylene
Propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1
Examples include olefin resins such as copolymers, ethylene-propylene-butene-1 copolymers, ethylene-vinyl acetate copolymers, ionically crosslinked olefin copolymers (ionomers), and blends thereof; , styrene-based resins such as styrene-butadiene copolymers, styrene-isobrene copolymers, and ABS resins, thermoplastic polyesters such as polyethylene phthalate, polytetramethylene terephthalate, and polycarbonates. As in the case of ethylene-vinyl alcohol copolymer, there are cases where sufficient adhesion cannot be obtained between the gas barrier resin and the moisture-resistant thermoplastic resin used during lamination. An adhesive resin layer is interposed in between. Such adhesive resins include carboxylic acid,
Carbonyls based on carboxylic acid anhydrides, carboxylic acid salts, carboxylic acid amides, carboxylic acid esters, etc.

Thermoplastic resins containing the group [Formula] in the main chain or side chain in a concentration of 1 to 700 mep/100 g resin, particularly 10 to 500 mep/100 g resin. Suitable examples of adhesive resins include ethylene-acrylic acid copolymers, ionically crosslinked olefin copolymers, maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene,
Acrylic acid grafted polyolefin, ethylene-
It is one or a combination of two or more of vinyl acetate copolymers, copolymerized polyesters, copolymerized polyamides, and the like. These resins are useful for lamination by coextrusion, Sand-German lamination, and the like. Furthermore, thermosetting adhesive resins such as isocyanate-based or epoxy-based adhesive resins are also used for adhesive lamination of the preformed gas barrier resin film and moisture-resistant resin film. In the multilayer structure of the present invention, the moisture-resistant resin layer generally has a thickness of 20 to 3000 μm, particularly 100 to 1500 μm.
and 0.1 to 600 times the thickness of the intermediate layer, especially 1 to 600 times the thickness of the intermediate layer.
It is better to have 150 times the thickness. Further, the inner layer and the outer layer may have the same thickness, or either the inner layer or the outer layer may be thicker than the other layer. The container of the present invention can be manufactured by a method known per se, except for the layered structure described above. In multilayer simultaneous extrusion, each resin layer is melt-kneaded using an extruder corresponding to the resin layer, and then extruded into a predetermined shape through a multilayer die such as a T-0 die or a circular die. Further, after melting and kneading each resin layer with an injection machine corresponding to the resin layer, the resin is co-injected or sequentially injected into an injection mold to produce a multilayer container or a preform for a container. Furthermore, lamination methods such as dry lamination, sandwich lamination, and extrusion coating may also be employed. The molded article can take the form of a film, a sheet, a parison or vipe for forming bottles or tubes, a preform for forming bottles or tubes, and the like. Formation of bottles from parisons, pipes or preforms is easily accomplished by pinching off the extrudate between a pair of split dies and blowing fluid into the interior. In addition, after the pipe or preform is cooled, it is heated to a stretching temperature, stretched in the axial direction, and blow-stretched in the circumferential direction using fluid pressure, thereby obtaining a stretched blown bottle or the like. Furthermore, by subjecting the film or sheet to vacuum forming, pressure forming, stretch forming, plug assist forming, or the like, packaging containers in the form of cups, trays, etc. can be obtained. Furthermore, in the case of multilayer films, they can be stacked or folded into a bag and the periphery heat-sealed to form a bag-like container. (Effects of the Invention) According to the present invention, in the moisture-resistant resin inner and outer layers, in the sandwich moisture absorption-resistant oxygen barrier resin intermediate layer,
Alternatively, by incorporating an oxygen scavenger into a hygroscopic resin used as an intermediate layer in combination with an oxygen barrier resin, moisture and heat can act simultaneously like heat sterilization, and the original properties of the oxygen barrier resin can be improved. Even under conditions where the oxygen barrier properties of the container are significantly reduced, the oxygen scavenger activated by moisture replenishment through moisture absorption and heat effectively captures oxygen that attempts to pass through the vessel wall and prevents its penetration. It has become possible to suppress the oxygen concentration inside the container to a significantly low level. (Example) Example 1 Oxygen permeability coefficient at 20℃ and 0%RH is 4×10 ^-14
cc・cm/cm ²・sec・cmHg and 20℃ and 100%
Ethylene-vinyl alcohol copolymer (ethylene content: 32 mol%, degree of saponification: 99.6 mol%) pellets with a moisture adsorption amount of 4.8% at RH and an iron-based oxygen scavenger with an average particle size of 40 μm are mixed using a batch-type high-speed stirring blade. The mixture was mixed using a mold mixer (Hersiel mixer). The mixing ratio was such that the content of the oxygen scavenger was 7% by weight. This mixture was then pelletized using a pelletizer consisting of an extruder/strand die/blower cooling layer/cutter equipped with a screw having a diameter of 50 mm. The above pelletized ethylene vinyl alcohol copolymer and oxygen scavenger mixture (EO) were used as an intermediate layer, and the melt index was 0.5 g/10 min (230°C).
A symmetrical three-type, five-layer sheet with polypropylene (PP) as the inner and outer layers and maleic anhydride-modified PP (ADH) with a melt index of 1.0 g/10 min as the adhesive layer (total thickness 0.9 mm, composition ratio PP/ADH). /EO/
ADH/PP=12/1/2/1/12) with a 50 mm diameter inner and outer layer extruder / 32 mm diameter adhesive extruder / 32 mm diameter middle layer extruder / feed block / T-die / cooling roll / sheet take-up machine It was molded using a multilayer sheet molding machine consisting of: The obtained 5-layer sheet of 3 types was heated to about 190°C and then molded to a height of 15 mm using a vacuum forming machine.
A cup-shaped container with a diameter of 100 mm and an internal volume of 117 ml was molded. Place this cup in a nitrogen atmosphere with 2 ml of distilled water.
was filled and heat-sealed with a sealant made of aluminum foil/PP. This container was heat sterilized at 120°C for 30 minutes. After sterilization, 20℃, 60%RH
The oxygen concentration in the container was measured using a gas chromatograph (GC) after a certain period of time. In addition, as a control product, measurements were also conducted on cups that were molded, filled, sealed, and heat sterilized in the same manner without incorporating an oxygen scavenger into the ethylene-vinyl alcohol copolymer. The results are shown in Table 1. The product of the present invention containing an oxygen scavenger has a remarkable effect, and the amount of oxygen permeated is 1/1
It became 3 or less. Example 2 Oxygen permeability coefficient at 20℃ and 0%RH is 5×10 ^-11
cc・cm/cm ²・sec・cmHg or more and 20℃ and 100
Add 2wt% of iron-based oxygen scavenger with an average particle size of 40μm to polypropylene (PP) with a moisture adsorption amount of 0.5% or less at %RH and a melt index (MI) of 0.5g/10min (230℃). The mixture was mixed using a batch-type high-speed stirring vane type mixer (Hensiel mixer) so that the mixture was mixed. Then, it was pelletized using the pelletizer of Example 1. The above pelletized PP containing oxygen scavenger
(PPO) for the inner and outer layers, ethylene vinyl alcohol copolymer (ethylene content 32 mol%, saponification degree 99.6)
Mol%) (E) as the intermediate layer and maleic anhydride-modified PP (ADH) of Example 1 as the adhesive layer. Symmetrical three-type, five-layer sheet (total thickness 0.9 mm, composition ratio PPO/AH/
E/ADH/PPO=12/1/2/1/12) was molded using the multilayer sheet molding apparatus of Example 1, and a cup-shaped container was molded in the same manner. In the same manner as in Example 1, the container was filled with 2 ml of distilled water in a nitrogen atmosphere, sealed, and heat sterilized, and the amount of oxygen in the container was measured after a certain period of time using a gas chromatograph. As a control product, similar cups used for the inner and outer layers of PP without oxygen scavenger were used. The results are shown in Table 1. When blended into PP, it does not show as remarkable an effect as in Example 1. Example 3 Oxygen permeability coefficient at 20℃ and 0%RH is 6×10 ^-13
cc・cm/cm ²・sec・cmHg and 20℃ and 100%
Nylon-6/6 with 8.1% moisture adsorption at RH,
10 copolymer (Mitsubishi Kasei, Novamit 2030) pellets were pelletized with an iron-based oxygen scavenger with an average particle size of 40 μm by the method of Example 1, and the same PP, ADH, and nylon (NO) containing an oxygen scavenger were used. Control 3 types 5
Layer (total thickness 0.9mm, composition ratio: PP/ADH/NO/
ADH/PP=12/1/2/1/12) sheet was created. Next, the container was filled with 2 ml of distilled water in a nitrogen atmosphere, sealed, and heat sterilized in the same manner, and the change in oxygen concentration inside the container was measured by GC at every fixed period of time. As a control product, a similar test was conducted using nylon containing no oxygen scavenger. The results are shown in Table 1. The product using nylon resin mixed with an oxygen scavenger showed a remarkable effect, reducing the amount of oxygen permeating through the container wall to about 1/3. Example 4 Oxygen permeability coefficient at 20℃ and 0%RH is 4×10 ^-14
cc・cm/cm ²・sec・cmHg and 20℃ and 100%
Ethylene-vinyl alcohol copolymer (ethylene content: 32 mol%, degree of saponification: 99.6 mol%) with a water adsorption amount of 4.8% at RH. Phenol with a polyhydric phenol skeleton synthesized by the following method.
Example 1: Adjusting the aldehyde resin to 20% by weight
Pelletize the container using the method described above, form it into a sheet using the same method, form it into a cup, fill it, seal it, and heat sterilize it.The oxygen concentration inside the container is checked by GC after a certain period of time.
Measured at The results are shown in Table 1. As a control product, a similar cup containing no phenolic aldehyde resin having a polyvalent phenol skeleton was used. <Phenol/aldehyde resin having polyhydric phenol in its skeleton> 238 g of a 37% formaldehyde aqueous solution was reacted with 1 mole of methylhydroquinone at 80°C for 1 hour in the presence of an acidic catalyst, and then poured into hot water with high speed stirring. The powder of the resin was obtained. The oxygen permeability of the container using the present invention was reduced to about 1/2, and a remarkable effect was observed. Example 5 Ethylene pelletized by the method of Example 1
Vinyl alcohol copolymer and iron-based oxygen scavenger mixture (EO) are used as the intermediate layer, anti-boiling polycarbonate resin (PC, Teijin Kasei Panlite K-1300) is used as the inner and outer layers, maleic anhydride modified PP (ADH, Admer) is used as the inner and outer layer. 5050) as an adhesive layer, cup forming, filling, sealing, and
Heat sterilization was performed, and the oxygen concentration in the container was measured using GC at regular intervals. As a control product, a similar cup made of PET without oxygen scavenger was used. The results are shown in Table 1. The product of the present invention showed obvious effects compared to the control product. Example 6 The ethylene-vinyl alcohol copolymer (E) used in Example 1 was used as the first intermediate layer, and the iron-based oxygen scavenger was added to a thermoplastic water-absorbing resin (Mitsubishi Yuka: Prawet) as the second intermediate layer. (WO) is used as the inner and outer layer, and MI is 0.5g/
A sheet of 7 layers of 4 types (total thickness 0.9 mm, composition ratio: PP/ ADH/E/ADH/WO/ADH/PP
= 12/1/1/1/1/1/12) was formed into a cup, filled, sealed, and heat sterilized using the method of Example 1, and the oxygen concentration in the container was measured every certain period of time. did. As a control product, a container with the same structure without oxygen scavenger was used. A clear effect was seen.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the multilayer structure of the container of the present invention. In FIG. , 4...
... Moisture-resistant resin inner layer, 5... Moisture-resistant resin outer layer, respectively. FIG. 2 is a sectional view showing another example of the multilayer structure of the container of the present invention. In FIG. 2, 1...film wall, 2a...
Gas barrier resin layer, 2b...hygroscopic resin layer containing oxygen scavenger, 3a, b, c...adhesive layer, 4...
5 represents a moisture-resistant resin inner layer, and 5 represents a moisture-resistant resin outer layer, respectively.

Claims (1)

[Claims] 1. Oxygen permeability coefficient at 20°C and 0% RH is 10 ^-12
cc・cm/ ^cm2・sec・cmHg or less and at 20℃ and 100℃
The intermediate layer is a resin composition in which a gas barrier thermoplastic resin with a moisture adsorption amount of 0.5% or more at %RH is blended with an oxygen scavenger, and a moisture-resistant thermoplastic resin layer is provided on both sides of the intermediate layer. A plastic multilayer container characterized by being composed of a laminated structure. 2. A multilayer plastic container according to claim 1, wherein the oxygen scavenger is present in an amount of 1 to 1000% by weight based on the gas barrier thermoplastic resin. 3. The multilayer plastic container according to item 1, wherein the gas barrier thermoplastic resin is an ethylene-vinyl alcohol copolymer having an ethylene content of 20 to 60 mol%. 4. The multilayer plastic container according to item 1, wherein the gas barrier thermoplastic resin is a polyamide having a number of amide groups in the range of 5 to 50 per 100 carbon atoms. 5. The multilayer plastic container according to item 1, wherein the oxygen scavenger is a reducing metal powder or its compound, or a polymeric compound having a polyvalent phenol in its skeleton. 6. The multilayer plastic container according to item 1, wherein the moisture-resistant thermoplastic resin is an olefin resin, styrene resin, polycarbonate, or polyester. 7 Oxygen permeability coefficient at 20℃ and 0%RH is 10 ^-12
cc・cm/cm ²・sec・cmHg or less gas barrier thermoplastic resin is used as the first intermediate layer and at 20°C and 100°C.
The second intermediate layer is a resin composition made of a hygroscopic thermoplastic resin with a moisture adsorption amount of 0.5% or more at %RH and an oxygen scavenger, and a moisture-resistant thermoplastic resin layer is provided on both sides of the intermediate layer. A plastic multilayer container comprising a laminated structure.