JP2002210887A - Multi-layer container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-layer container which is excellent in peeling properties between impact resistant layers, appearance such as transparency and perspective properties, gas-barrier properties, etc. SOLUTION: A resin composition (I) comprising a saponified ethylene-vinyl acetate copolymer (A), a polyamide resin (B) 160 deg.C or below in melting point, and at least one (C) selected from alkali metals, alkaline earth metals, and boron is made an intermediate layer, and thermoplastic polyester resin (II) layer are arranged on both sides of the intermediate layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multilayer container comprising a layer of a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) composition and a layer of a thermoplastic polyester resin.

[0002]

2. Description of the Related Art In general, EVOH is excellent in transparency, gas barrier property, fragrance retention, solvent resistance, oil resistance and the like.
It is used by being molded into films and sheets of industrial chemical packaging materials, agricultural chemical packaging materials, etc., or containers such as bottles. In particular, the moisture proof properties of the containers, the barrier properties of carbon dioxide and aroma components, the mechanical properties, etc. EVO for the purpose of improving performance
A multilayer container in which a polyester-based resin (mainly polyethylene terephthalate, hereinafter abbreviated as PET) is laminated on both sides of the H layer is used.

[0003] Recently, attention has been paid to pressure-resistant bottles of soft drinks and alcoholic beverages containing carbonic acid. On the other hand, PET has excellent transparency and rigidity, moderate gas barrier properties, and fragrance retention properties, and is widely used for containers for carbonated drinks and soft drinks. The gas barrier property is insufficient for the required use, and as described above, it can be used as an excellent gas barrier container by lamination with the EVOH layer.

However, in general, a thermoplastic polyester resin such as PET and EVOH have poor adhesiveness. To improve their delamination strength and delamination resistance, a representative example is disclosed in JP-A-59-188433. Therefore, it is necessary to interpose a specific adhesive resin between the layers.
However, recently PET has been recycled and reused, and if an adhesive resin exists between layers,
Separation of PET and EVOH becomes difficult, and as a result, there arises a problem that the quality of recycled PET deteriorates, and it is difficult to be accepted in the market.

Therefore, without using such an adhesive resin, E
A multilayer container in which a polyester-based resin (PET) layer is laminated on both sides of a VOH layer is desired. As a laminate used in such a multilayer container, a PET layer / EVOH layer / PET in which the position of the EVOH layer is devised is used. Layer laminate (JP-A-61-173924), PET layer / regrind layer / EVOH layer / regrind layer / PET layer laminate (JP-A-62-28332), PET layer / EVO
H (two blends) layer / PET layer laminate (JP-A-62
JP-A-271831, JP-A-2-139237), PET layer / EVOH (two types blend) layer / PET
Layer / EVOH (two types of blend) layer / PET layer laminate (JP-A-1-204736), PET layer / EVO
H (other resin blend) layer / PET layer / EVOH (other resin blend) layer / PET layer laminate (JP-A-11-791)
No. 56), PET layer / EVOH (low saponification product) layer /
PET layer laminate (JP-A-11-348194,
JP-A-11-348195, JP-A-11-348
196, JP-A-11-348197) have been proposed.

[0006]

However, the laminates described in JP-A-61-173924, JP-A-62-28332 and JP-A-2-139237 suffered an impact force. In this case, the delamination resistance (impact delamination resistance), especially at low temperatures, is insufficient. Also, JP-A-62-271831, JP-A-1-20
Also in the laminates described in JP-B-4736 and JP-A-11-79156, although the impact delamination is improved to some extent, the gas barrier property is reduced and the transparency and transparency of the container are deteriorated. Has a point,
Further, JP-A-11-348194, JP-A-11-348
In the laminates described in JP-A-348195, JP-A-11-348196, and JP-A-11-348197, a certain improvement in the impact delamination resistance is recognized, and the degree of deterioration in transparency and transparency is also reduced. Although using a small amount of EVOH having a degree of saponification of 99 mol% or less,
There is a problem that the gas barrier property is insufficient, and a multilayer container of an EVOH layer and a PET layer excellent in impact delamination resistance, appearance such as transparency and transparency, gas barrier property, and the like is desired.

[0007]

In view of this situation, the present inventor has conducted intensive studies on a multilayer container composed of an EVOH layer and a PET layer. As a result, EVOH (A),
A resin composition (I) containing a polyamide resin (B) having a melting point of 160 ° C. or less and at least one kind (C) selected from alkali metals, alkaline earth metals and boron is used as an intermediate layer, and on both sides thereof Thermoplastic polyester resin (I
The inventors have found that a multilayer container having the layer (I) can achieve the above object, and have completed the present invention.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The multilayer container of the present invention has an EVOH (A) and a melting point of 160 ° C.
The intermediate layer is a resin composition (I) containing the following polyamide resin (B) and at least one kind (C) selected from alkali metals, alkaline earth metals, and boron. A) is not particularly limited, but has an ethylene content of 5 to 70 mol% (further 20 to 60 mol%, particularly 25 to 50 mol%) and a degree of saponification of 95 mol% or more (further 99 mol%). % Or more, especially 9
When the ethylene content is less than 5 mol%, the gas barrier properties and melt moldability at high humidity are reduced, and when the ethylene content exceeds 70 mol%, sufficient gas barrier properties are obtained. If the saponification degree is less than 95 mol%, the gas barrier properties, thermal stability, moisture resistance, etc. are lowered, which is not preferable for the use of the multilayer container of the present invention.

The melt flow rate (MFR) of the EVOH (210 ° C., load 2160 g) is 1-10.
0 g / 10 min (further 3 to 50 g / 10 min, especially 6 to 10 g
If the melt flow rate is smaller than the above range, the moldability of the obtained multilayer container may be reduced. If the melt flow rate is larger than the above range, the obtained multilayer container may be reduced. Is unfavorable because the mechanical strength may decrease.

The EVOH is obtained by saponifying (A) an ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer can be produced by any known polymerization method, for example, solution polymerization, suspension polymerization, It is produced by emulsion polymerization or the like, and saponification of an ethylene-vinyl acetate copolymer can be performed by a known method.

In the present invention, a copolymerizable ethylenically unsaturated monomer may be copolymerized as long as the effects of the present invention are not impaired. Examples of such a monomer include propylene and 1-butene. , Olefins such as isobutene, acrylic acid, methacrylic acid, crotonic acid, (anhydrous) phthalic acid,
Unsaturated acids such as (anhydride) maleic acid and (anhydride) itaconic acid or salts thereof, mono- or dialkyl esters having 1 to 18 carbon atoms, acrylamide, 1 to 1 carbon atoms
8, acrylamides such as N-alkylacrylamide, N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or a salt thereof, acrylamidopropyldimethylamine or an acid salt thereof or a quaternary salt thereof, methacrylamide, having 1 to 18 carbon atoms Methacrylamides such as N-alkyl methacrylamide, N, N-dimethyl methacrylamide, 2-methacrylamidopropanesulfonic acid or a salt thereof, methacrylamidopropyldimethylamine or an acid salt thereof or a quaternary salt thereof, N-vinylpyrrolidone N-vinylamides such as, N-vinylformamide and N-vinylacetamide;
Vinyl cyanides such as acrylonitrile and methacrylonitrile, vinyl ethers such as alkyl vinyl ethers having 1 to 18 carbon atoms, hydroxyalkyl vinyl ethers and alkoxyalkyl vinyl ethers, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride and vinyl bromide And vinylsilanes such as trimethoxyvinylsilane, allyl acetate, allyl chloride, allyl alcohol, dimethylallyl alcohol, trimethyl- (3-acrylamido-3-dimethylpropyl)-
Examples thereof include ammonium chloride and acrylamide-2-methylpropanesulfonic acid. Further, post-modification such as urethanization, acetalization, and cyanoethylation may be performed as long as the gist of the present invention is not impaired.

The polyamide resin (B) used in the present invention has a melting point of 160 ° C. or less and a melting point of 160 ° C.
The effect of the present invention cannot be obtained even if a polyamide resin exceeding ℃ is used. Further, a resin having a melting point of 80 to 150 ° C is preferable, and a resin having a melting point of 80 to 140 ° C is particularly preferable. Here, the melting point is a melting peak temperature (° C.) measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC).

Specific examples of the polyamide resin (B) include polycapramide (nylon 6),
ω-aminoheptanoic acid (nylon 7), poly-ω-aminononanoic acid (nylon 9), polyundecaneamide (nylon 11), polylauryl lactam (nylon 1
2), polyethylene diamine adipamide (nylon 2
6), polytetramethylene adipamide (nylon 4
6), polyhexamethylene adipamide (nylon 6
6), polyhexamethylene sebacamide (nylon 61
0), polyhexamethylene dodecamide (nylon 61
2), polyoctamethylene adipamide (nylon 8,
6), polydecamethylene adipamide (nylon 10
8), caprolactam / lauryl lactam copolymer (nylon 6/12), caprolactam / ω-aminononanoic acid copolymer (nylon 6/9), caprolactam / hexamethylene diammonium adipate copolymer (nylon 6/66), Lauryl lactam / hexamethylene diammonium adipate copolymer (nylon 12/6
6), ethylenediamine adipamide / hexamethylenediammonium adipate copolymer (nylon 26/6
6), caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon 66/610), ethylene ammonium adipate / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon 6 / 66/610), polyhexamethylene isophthalamide, polyhexamethylene terephthalamide, hexamethylene isophthalamide / terephthalamide copolymer or a polyamide resin modified with an aromatic amine such as methylenebenzylamine or meta-xylenediamine And meta-xylylenediammonium adipate, among these types,
Those having a melting point of 160 ° C. or less are used.

The method for lowering the melting point of the polyamide resin to 160 ° C. or lower is not particularly limited. However, industrially, it is preferable to use a copolymer having a specific ratio among the above polyamide resins. Specific examples of the combined nylon include nylon 6/12, nylon 6/69, and nylon 6.
/ 66/610, Nylon 6/66/610/12, Nylon 6/66/610/11, and modified aromatic amines thereof. Specific commercially available trade names include "Amilan CM4000". , “Amilan CM800
0 ”,“ Amiran CM6541-X3 ”,“ Amiran C
M831, "Amilan CM833" (all manufactured by Toray Industries), "Elvamide 8061", "Elvamide 8062"
S "," Elvamide 8066 "(all manufactured by DuPont Japan)," Grillon CF6S "," Grillon CF62 "
BS ”,“ Grillon CA6E ”,“ Grillon XE338
1 "," Grillon BM13SBG "(above, manufactured by MMS Japan)," UBE7128B "," UBE7028 "
B "(above, manufactured by Ube Industries).

The polyamide resin (B) was measured using a differential scanning calorimeter (DSC) (heating rate 10 ° C. /
min) is preferably 80 J / g or less (more preferably 5 to 70 J / g, particularly 10 to 60 J / g). When the heat of fusion ΔH exceeds 80 J / g, the impact resistance Undesirably, the effect of improving the appearance such as peelability, transparency and transparency cannot be sufficiently obtained. The method for reducing the heat of fusion ΔH of the polyamide resin to 80 J / g or less is not particularly limited. However, industrially, the degree of polymerization, the molecular weight, the molecular weight distribution, the content of the low molecular weight component, the water content, It can be suitably performed by controlling the amount of the residual monomer and the like.

Further, the melt flow rate (MFR) of the polyamide resin (B) (210 ° C., load 2160
g) is 1 to 100 g / 10 minutes (further 3 to 80 g / 1
0 minutes, especially 5 to 50 g / 10 minutes).
When R is out of the above range, the effect of improving appearance such as impact delamination property and transparency / transparency may not be sufficiently obtained, which is not preferable. The method for adjusting the MFR of the polyamide resin to the above range is not particularly limited. However, industrially, the degree of polymerization, the molecular weight, the molecular weight distribution, the content of the low molecular weight component, the water content, the residual monomer amount, and the like of the polyamide resin are determined. It can be suitably performed by controlling.

In the present invention, the polyamide resin (B) includes a structure, a composition, a melting point, a heat of fusion, and a molecular weight (MF).
R), two or more kinds of polyamide resins having different molecular weight distributions can be used in combination.

Further, among the at least one kind (C) selected from the alkali metals, alkaline earth metals and boron used in the present invention, the alkali metals and alkaline earth metals include sodium, potassium, calcium, magnesium and manganese. , Copper, cobalt, zinc and the like,
Among them, sodium, potassium, calcium, magnesium, and zinc are preferable, and in containing these metals, fatty acids such as acetic acid and stearic acid, and boric acid, and metal salts such as inorganic acids such as phosphoric acid, It is preferable because the effect of the present invention is particularly excellent.

It is preferable that boron is contained as a boron compound in terms of particularly excellent effects of the present invention. Examples of such a compound include boric acid, calcium borate, cobalt borate, zinc borate (tetraborate Zinc, zinc metaborate, etc.), aluminum / potassium borate, ammonium borate (ammonium metaborate, ammonium tetraborate, ammonium pentaborate, ammonium octaborate, etc.), cadmium borate (cadmium orthoborate, tetraborate) Cadmium, etc.), potassium borate (potassium metaborate, potassium tetraborate, potassium pentaborate,
Potassium hexaborate, potassium octaborate, etc.), silver borate (silver metaborate, silver tetraborate, etc.), copper borate (cupric borate, copper metaborate, copper tetraborate, etc.), boric acid Sodium (sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc.), lead borate (lead metaborate, lead hexaborate, etc.), boric acid Nickel (nickel orthoborate, nickel diborate, nickel tetraborate, nickel octaborate, etc.), barium borate (barium orthoborate, barium metaborate, barium diborate, barium tetraborate, etc.), bismuth borate , Magnesium borate (magnesium orthoborate, magnesium diborate,
Magnesium metaborate, trimagnesium tetraborate, pentamagnesium tetraborate, etc., manganese borate (manganese borate, manganese metaborate, manganese tetraborate, etc.), lithium borate (lithium metaborate, tetraborate) Lithium, lithium pentaborate, etc.), and borate minerals such as borax, carnite, inyoite, colotolite, sianite, ziberite, etc., and preferably boric acid, borax, boric acid. Sodium (sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc.) is used.

The content of (A) to (C) in the resin composition (I) used in the present invention is not particularly limited.
The content weight ratio (A / B) of (A) and (B) is 50/5
0 to 99/1 (further 60/40 to 97/3, especially 7
0/30 to 95/5, particularly preferably 80/20 to 95/5). When the weight ratio is smaller than 50/50, the gas barrier properties may be insufficient, and conversely 99%.
When the ratio is larger than / 1, the effect of improving appearance such as impact delamination property, transparency and transparency may be insufficient, which is not preferable.

The content of (C) is 0.001 to 1 with respect to 100 parts by weight of the total amount of (A) and (B).
Parts by weight (further 0.002 to 0.5 parts by weight, particularly 0.0
It is preferable that the content is less than 0.001 part by weight. If the weight is less than 0.001 part by weight, the effect of improving the appearance such as impact delamination property and transparency / transparency is improved. On the other hand, when the amount is more than 1 part by weight, the appearance of the finally obtained multilayer container may be deteriorated, which is not preferable.

When two or more kinds of polyamide resins (B) having different structures, compositions, melting points, heats of fusion, molecular weights (MFR), molecular weight distributions and the like are used in combination as the polyamide resin (B), the total The weight only has to be in the above range. In addition, an alkali (earth) metal salt of boric acid may be contained, or boric acid and an alkali (earth) such as fatty acid and phosphoric acid may be contained.
When at least two kinds (C) of an alkali metal, an alkaline earth metal, and boron are contained such that a metal salt is contained, the total weight may be within the above range.

In order to obtain the resin composition (I) comprising the above (A) to (C), the components (A) to (C) may be blended. (1) a method in which the components (A) and (B) are melt-kneaded after the components (A) and (B) are melt-kneaded, and a component (C) is added and further melt-kneaded; A method in which the component (B) is melt-kneaded after the component (C) is contained,
A method of melt-kneading the component (A) after the component (C) is added to the component (B), and melt-kneading both the components (A) and (B) after the component (C) is included in each of the components. And a method of uniformly dissolving and mixing the components (A) to (C) in a solvent capable of dissolving the components, and then removing the solvent. This will be described in more detail, but is not limited thereto.

When the component (C) is contained in the EVOH (A), the EVOH (A) can be suitably contained in production by bringing the EVOH (A) into contact with the aqueous solution of the component (C).
At this time, the concentration of the component (C) in the aqueous solution is 0.001 to 1% by weight (more preferably 0.005 to 0.8% by weight, particularly 0.01 to 1% by weight) in terms of metal or boron. 0.5
If the amount is less than 0.001% by weight, it becomes difficult to contain a predetermined amount of the component (C). Conversely, if it exceeds 1% by weight, the appearance of the finally obtained multilayer container will be poor. It is not preferable because it may worsen.

The method of bringing EVOH (A) into contact with such an aqueous solution is not particularly limited. Usually, the above-mentioned component (C) is added to the aqueous solution while stirring the EVOH (A) formed into pellets and stirring. Is preferably contained. In preparing (molding) the EVOH pellets described above, a known method can be employed.
After extruding a mixed solution of VOH water and alcohol into a coagulating liquid into a strand or a sheet, the resulting strand or sheet may be cut into pellets.
As the shape of such a pellet-shaped EVOH, a columnar shape,
It is preferably spherical or the like, and in the case of a column, the diameter is 1 to 1
0 mm and a length of 1 to 10 mm are preferable. In the case of a spherical shape, a diameter of 1 to 10 mm is preferable.

The EVOH has a diameter of 0.1 to 0.1 mm.
Those having a microporous internal structure in which pores of about 10 μm are evenly distributed are preferable in that the component (C) can be uniformly contained. Usually, an EVOH solution (a mixed solvent of water / alcohol) is used in a coagulation bath. When extruding, the concentration of the EVOH solution (20 to 80% by weight) and the extrusion temperature (45 to
70 ° C.), type of solvent (water / alcohol mixture weight ratio = 8)
0 / 20-5 / 95 etc.), the temperature of the coagulation bath (1-20
C), the residence time (0.25 to 30 hours), the amount of EVOH in the coagulation bath (0.02 to 2% by weight), and the like can be arbitrarily adjusted to obtain an EVOH having the structure. .
Further, those having a water content of 20 to 80% by weight are preferable because the compounds and the like can be uniformly and rapidly contained. In adjusting the content of the component (C), there is no particular limitation, but in the contact treatment with the aqueous solution described above, the concentration of the aqueous solution of the component (C), the contact treatment time, the contact treatment temperature, and the stirring speed during the contact treatment. Or by controlling the moisture content of the EVOH to be treated.

Thus, a pellet-shaped hydrous EVOH composition containing the component (C) is obtained.
Drying is performed after the above contact treatment.

As such a drying method, various drying methods can be adopted. For example, an EVOH composition substantially in the form of pellets is fluidized and dried while being stirred or dispersed by mechanical or hot air, or an EVOH composition substantially in the form of pellets is dynamically stirred or dispersed. Stationary drying performed without any action is given. Dryers for performing fluidized drying include a cylindrical / groove type stirring dryer, a cylindrical dryer, a rotary dryer, a fluidized bed dryer, and a vibrating fluidized bed. Dryers, conical rotary dryers, etc. are also available. In addition, as a dryer for performing stationary drying, a batch type box dryer is used as a material stationary type, and a band dryer and tunnel drying is used as a material transfer type. , A vertical dryer and the like, but are not limited thereto. It is also possible to combine fluidized drying and standing drying.

Air or an inert gas (nitrogen gas, helium gas, argon gas, etc.) is used as a heating gas used in the drying process. The temperature of the heating gas is 40 to 150 ° C. It is preferable from the viewpoint of preventing thermal deterioration of the EVOH composition. The drying time is E
Although it depends on the water content of the VOH composition and the amount of treatment thereof, usually about 15 minutes to 72 hours is preferable in terms of productivity and prevention of thermal deterioration of the EVOH composition.

The EVOH composition is dried under the above conditions to obtain a composition (A + C) comprising the EVOH (A) and (C) components. The composition (A + C) after the drying treatment is obtained. The water content is preferably 0.001 to 5% by weight (further preferably 0.01 to 2% by weight, especially 0.1 to 1% by weight), and the water content is 0.001% by weight.
If it is less than 5, the long-run moldability of the finally obtained resin composition (I) tends to decrease, and if it exceeds 5% by weight, foaming occurs during melt-kneading with the polyamide resin (B) described later. It is not preferable because it becomes easy.

The thus obtained composition (A + C) comprising the EVOH (A) and the component (C) [pellet of the component (A) containing the component (C)] further had a melting point of 160.
The polyamide resin (B) having a temperature of not more than 0 ° C. is melt-kneaded, but the melt-kneading is not particularly limited.
It is sufficient that the composition and the polyamide resin (B) are sufficiently melt-kneaded, and a known method can be employed. For example, kneader ruder, extruder, mixing roll,
Known kneading apparatuses such as a Banbury mixer and a plastomill can be used. It is preferable to melt and knead at 150 to 300 ° C. (furthermore, 180 to 280 ° C.) for about 1 minute to 1 hour. It is advantageous to use an extruder such as a screw extruder or a twin-screw extruder, and if necessary, it is also preferable to provide a vent suction device, a gear pump device, a screen device, and the like.

In particular, in order to remove moisture and by-products (such as low-molecular weight pyrolysis products), one or more vent holes are provided in the extruder, and the extruder is suctioned under reduced pressure. By continuously supplying an inert gas such as nitrogen into the hopper to prevent mixing, a resin composition (I) of excellent quality with reduced thermal coloring and thermal deterioration can be obtained. In the melt kneading, 1) the solid composition (A +
C) a method in which the polyamide resin (B) and the polyamide resin (B) are collectively mixed and melt-kneaded; 2) a method in which the solid polyamide resin (B) is charged into the molten composition (A + C) and melt-kneaded; 3) A method in which the solid composition (A + C) is charged into the molten polyamide resin (B) and melt-kneaded. 4) The composition (A + C) in the molten state and the polyamide resin (B) are mixed. Examples of the method include melt kneading.

The multilayer container of the present invention comprises the above-described resin composition (I) as an intermediate layer and a thermoplastic polyester resin (II) layer disposed on both sides thereof. The resin (II) is not particularly restricted but includes, for example, aromatic dicarboxylic acids or condensation polymers containing these alkyl esters and glycols as main components, typically those having ethylene terephthalate as a main repeating unit. Is preferred. Further, it is also possible to contain a copolymer component within a range that does not significantly impair workability, strength, and the like. As such a copolymer component, isophthalic acid, diphenyl-4,4′-
Dicarboxylic acid, diphenoxyethane dicarboxylic acid, 2,
Aromatic dicarboxylic acids such as 6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid and ester-forming derivatives thereof, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid and succinic acid and ester-forming thereof Derivatives, cyclohexanedicarboxylic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid and ester-forming derivatives thereof, p-oxybenzoic acid,
In addition to oxyacids such as oxycaproic acid and their ester-forming derivatives, trimellitic acid, pyromellitic acid and the like can be mentioned. Further, as the glycol component, diethylene glycol, trimethylene glycol,
Aliphatic glycols such as tetramethylene glycol and neopentyl glycol, alicyclic glycols such as 1,4-cyclohexanedimethanol, aromatic glycols such as bisphenol A and alkylene oxide adducts of bisphenol A, polyethylene glycol, polypropylene glycol, and poly In addition to polyalkylene glycols such as tetramethylene glycol, glycerin, 1,3-propanediol, pentaerythritol and the like can be mentioned.

The content of the ethylene terephthalate unit is as follows:
It is about 75 to 100 mol%, preferably about 85 to 100 mol%. The preferred intrinsic viscosity (measured at a temperature of 30 ° C. in a 50% by weight / 50% by weight mixed solvent of phenol and tetrachloroethane) is 0.5 to 1.3 dl / g.
(Further, 0.65 to 1.2 dl / g).

Next, representatively, there are exemplified those having ethylene terephthalate as a main repeating unit. It is also possible to contain the same copolymer component as above,
The content of ethylene terephthalate is about 75 to 100 mol%, preferably about 85 to 98 mol%. Also,
Preferred intrinsic viscosity is 0.4 to 1.2 dl / g (further 0.55 to 1.0 dl / g).

It is also preferable to use the ethylene terephthalate-based polyester resin and the ethylene terephthalate-based resin in a blended manner in terms of improving gas barrier properties, ultraviolet shielding properties, and melt moldability. The content of the ethylene terephthalate-based polyester resin is 5 to 90% by weight, more preferably 15 to 85% by weight.
It is 5 to 10% by weight, further 85 to 15% by weight.

Further, other thermoplastic resins and additives can be blended as long as various properties are not significantly impaired. Examples of the thermoplastic resin include MXD-6 nylon, polycarbonate, polyarylate, liquid crystal polymer and the like. Is mentioned.

[0038] The multilayer container of the present invention is made of EVOH as described above.
(A), a polyamide resin having a melting point of 160 ° C. or less (B)
And an intermediate layer comprising a resin composition (I) containing at least one kind (C) selected from alkali metals, alkaline earth metals and boron, and thermoplastic polyester resin (II) layers disposed on both sides thereof The method for producing such a multilayer container will be described.

In producing the multilayer container of the present invention, a) a multilayer structure (sheet, film, parison, etc.) in which a thermoplastic polyester resin (II) is laminated on both sides of a layer composed of the resin composition (I) And a method of molding into a container, and a method of directly molding a multilayer container by co-injecting the resin composition (I) and the thermoplastic polyester resin (II) with a co-injection molding machine or the like. it can.

In the method (a), first, a thermoplastic polyester-based resin (II) layer is laminated on both sides of the resin composition (I) layer to produce a multilayer structure. , A method of melt-extruding a thermoplastic polyester resin (II) into a film or sheet comprising the resin composition (I), and a method of melt-extruding the resin composition (I) into a layer of the thermoplastic polyester resin (II) A method of co-extruding a resin composition (I) and a thermoplastic polyester resin (II), or a method of co-injecting a resin composition (I) and a thermoplastic polyester resin (II). A film or sheet composed of the composition (I) and a film or sheet composed of the thermoplastic polyester resin (II) are combined with an organic titanium compound, an isocyanate compound, a polyester compound, a polyurethane compound, or the like. And a method of dry lamination using a known adhesive.

Next, the obtained multilayer structure is molded into a container, and it is preferable to perform a heat-stretching treatment in this molding. It is possible to obtain a multilayer container which is free from cracks, uneven thickness and the like, and is excellent in gas barrier properties and transparency.

Here, the heat-stretch molding means that the multilayer structure is uniformly heated by various heaters, heat sources, etc.
This refers to the operation of uniformly forming various shapes using plugs, vacuum force, pneumatic force, and the like.

The heating stretching may be either uniaxial stretching or biaxial stretching. The heating stretching method includes roll stretching, tenter stretching, tubular stretching, stretch blowing, deep drawing, and the like. Vacuum forming method, pressure forming method, vacuum pressure forming method and the like can be adopted. In the case of biaxial stretching, any of a simultaneous biaxial stretching method and a sequential biaxial stretching method can be adopted. The temperature of the multilayer structure during the heat stretching is 80 to 17
The temperature is selected from the range of 0 ° C, preferably about 100 to 160 ° C.

In the present invention, it is particularly effective in a thick heat-stretched multilayer container such as a hollow container such as a bottle, a tank or a tube obtained by blow molding. There is no particular limitation, and examples thereof include a direct blow molding method, an injection blow molding method, and a co-injection biaxial stretch blow molding method. Can be Further, it is preferable to further heat-treat the hollow container obtained by blow molding, since the impact delamination property and the gas barrier property are improved. The heat treatment temperature is 100 to 240 ° C., and the heat treatment time is 1 second or more. Among these production methods, the co-injection biaxial stretching blow molding method is particularly preferred as the most suitable method for production. Hereinafter, such a method will be described in more detail, but is not limited thereto.

The co-injection biaxial stretch blow molding method is as follows.
At least the resin composition (I) layer is an intermediate layer, and a thermoplastic polyester resin (II) layer is disposed on both sides thereof.
A parison (also referred to as a container precursor or preform) having a multilayer structure is produced by co-injection molding, and then heated and mechanically stretched in the longitudinal direction while maintaining a constant temperature in a blow mold. Alternatively, it is a method in which pressurized air is blown in order to expand in the circumferential direction.

First, a parison having a multilayer structure is prepared. Usually, an injection molding machine having two injection cylinders and a multilayer manifold system is used, and a molten resin composition is placed in a single mold. It can be obtained by injecting (I) and thermoplastic polyester resin (II) simultaneously or at a different time from the respective injection cylinders through a multilayer manifold system. For example, first, the thermoplastic polyester resin (II) for both outer layers is injected, and then the resin composition (I) for the intermediate layer is injected,
After injecting a predetermined amount of the resin composition (I), the injection of the thermoplastic polyester-based resin (II) is further continued, so that the thermoplastic polyester-based resin (II) layer / resin composition (I)
Layer / thermoplastic polyester resin (II) layer consisting of three layers, and a bottomed parison in which an intermediate resin composition (I) layer is completely enclosed in thermoplastic polyester resin (II) layers on both sides. You get it.

The parison injection molding conditions include:
The injection molding temperature of the resin composition (I) is 150 to 300 ° C.
(Furthermore, 160 to 270 ° C, especially 170 to 230 ° C)
If the temperature is lower than 150 ° C., the melting of the resin composition (I) may be insufficient, and conversely, 300
When the temperature exceeds ℃, the appearance of the multilayer container obtained by the thermal decomposition of the resin composition (I) may be deteriorated or the odor may be remarkably increased, which is not preferable.

On the other hand, thermoplastic polyester resin (II)
Injection molding temperature of 230-350 ° C (further 250-
30 ° C., particularly preferably 270 to 310 ° C.) When the temperature is lower than 230 ° C., the melting of the thermoplastic polyester resin (II) may be insufficient, and conversely, 350 ° C.
Exceeding the range is not preferred because the appearance of the multilayer container obtained by the thermal decomposition of the thermoplastic polyester resin (II) may be deteriorated or the odor may be remarkable.

Further, the temperature of the multilayer manifold portion where the resin composition (I) and the thermoplastic polyester resin (II) join is 230 to 350 ° C. (furthermore, 250 to 330 ° C.
Particularly, it is preferably 270 to 310 ° C.) and the temperature is 2
If the temperature is lower than 30 ° C., the melting of the thermoplastic polyester resin (II) may be insufficient. On the other hand, if it exceeds 350 ° C., the thermal decomposition of the resin composition (I) and the thermoplastic polyester resin (II) may occur. However, the appearance of the multilayer container obtained by the above may be deteriorated or the odor may be remarkable, which is not preferable.

The temperature of the mold into which the resin composition (I) and the thermoplastic polyester resin (II) flow is from 0 to 80.
C. (more preferably 5 to 60 C., especially 10 to 30 C.). When the temperature is lower than 0 C., the appearance of a parison or a multilayer container which may cause dew condensation in a mold is reduced, and conversely, If the temperature is higher than 80 ° C., the blow moldability of the obtained parison may be reduced, and the transparency and transparency of the obtained multilayer container may be undesirably reduced.

Thus, a parison having a multilayer structure is obtained.
Alternatively, the desired multilayer container can be obtained by mechanically stretching in the longitudinal direction while maintaining a constant temperature in the blow mold by reheating and blowing the compressed air simultaneously or sequentially to expand in the circumferential direction. It is done. The hot parison method, in which the injection-molded parison is immediately sent to the reheating step in a warm state and blow-molded, the injection-molded parison is stored at room temperature for a certain period of time and then sent to the reheating step and blow-molded. Is the cold parison method,
Both can be adopted according to the purpose, but generally, the cold parison method is preferable in terms of excellent productivity.

The reheating of the parison can be performed using a heating element such as an infrared heater or a block heater. The temperature of the heated parison is 80-140 ° C
(More preferably 85 to 130 ° C., particularly 90 to 120 ° C.). If the temperature is lower than 80 ° C., the uniformity of stretching becomes insufficient and the shape and thickness of the obtained multilayer container may become uneven. On the other hand, when the temperature exceeds 140 ° C., crystallization of the thermoplastic polyester resin (II) is promoted, and the resulting multilayer container may be whitened, which is not preferable.

Next, the reheated parison is biaxially stretched to obtain the desired multilayer container. Generally, it is stretched about 1 to 7 times in the longitudinal direction, mechanically stretched by a plug, a rod, or the like.
It is stretched about twice and the intended multilayer container is obtained. The stretching in the longitudinal direction and the stretching in the lateral direction can be performed simultaneously or sequentially. In addition, it is also possible to use the pneumatic force at the time of stretching in the longitudinal direction.

In the method (b), a multilayer container such as a cup or a tray can be directly obtained by using a co-injection molding machine or the like without heating and stretching. It is also preferable to further heat-treat the obtained multilayer container in the same manner as in a).

Thus, the multilayer container of the present invention can be obtained. The layer constitution of the multilayer container is such that the layer composed of the resin composition (I) is composed of I and the layer composed of the thermoplastic polyester resin (II) is composed of In the case of II, not only the three-layer structure of II / I / II, but also II / I / II / I, II / I / II / I / II, II /
Any combination such as I / II / I / II / I, II / I / II / I / II / I / II is possible. Further, it is also possible to provide a regrind layer or a thermoplastic resin layer other than the resin composition (I) or the thermoplastic polyester resin (II). Such a thermoplastic resin is not particularly limited, and may be a linear resin. Low density polyethylene (LLDPE), low density polyethylene (L
DPE), very low density polyethylene (VLDPE), medium density polyethylene (MDPE), high density polyethylene (H
DPE), ethylene-vinyl acetate copolymer (EVA),
Ionomer, ethylene-propylene (block or random) copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, polypropylene ( PP), propylene-α-olefin (α-olefin having 4 to 20 carbon atoms) copolymer, homo- or copolymer of olefin such as polybutene, polypentene, polymethylpentene, or a polyolefin in a broad sense such as a blend thereof Resin, polyester resin, polyamide resin, copolymerized polyamide, polystyrene resin, polyvinyl chloride resin, polyvinylidene chloride, acrylic resin, vinyl ester resin, polyester elastomer, polyurethane elastomer, chlorinated polyethylene, salt Lightened polypropylene, aromatic and aliphatic polyketones, aliphatic polyalcohols and the like can be mentioned.

Further, the multilayer container of the present invention has excellent impact delamination resistance without using an adhesive resin between the resin composition (I) layer and the thermoplastic polyester resin (II) layer. Is obtained, it is also possible to use an adhesive resin if necessary, the adhesive resin is not particularly limited, and various types can be used, but generally, , Unsaturated carboxylic acids or their anhydrides as olefin polymers (the above-mentioned polyolefins in a broad sense)
And a carboxyl group-containing modified olefin-based polymer obtained by chemically bonding to a polymer by an addition reaction, a graft reaction, or the like.Specifically, maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene And a mixture of two or more selected from maleic anhydride graft-modified ethylene-ethyl acrylate copolymer, maleic anhydride graft-modified ethylene-vinyl acetate copolymer, and the like. At this time, the amount of the unsaturated carboxylic acid or anhydride contained in the olefin polymer is 0.001 to
It is preferably 1% by weight, more preferably 0.01 to 0.1%.
5% by weight. If the amount of modification in the modified product is small, the effect of improving interlayer adhesion is poor, and if it is too large, a crosslinking reaction occurs, and moldability may deteriorate, which is not preferable. Also,
In the present invention, I is a thermoplastic polyester resin (I
Blending the resin composition (I) with I) or II,
At least one of I and II may be blended with a resin that improves the adhesion between the two layers.

The thickness of each layer of the multi-layer container cannot be unconditionally determined depending on the layer constitution and the use when the container is used. However, usually, the resin composition (I) layer has a thickness of 1 to 100 μm (more preferably 5 to 50 μm). ) Is preferred, and the thickness of the thermoplastic polyester resin (II) layer is preferably 30 to 3000 µm (more preferably 50 to 1000 µm). If the resin composition (I) layer is less than 1 µm, gas barrier properties may be insufficient.
In addition, the thickness control may become unstable,
If it exceeds 0 μm, the impact resistance may be inferior, and it is not economical or unfavorable. If the thickness of the thermoplastic polyester resin (II) layer is less than 30 μm, the rigidity may be insufficient. And it is not economical and not preferable.

Thus, the multilayer container of the present invention is obtained. The resin composition (I) and the thermoplastic polyester resin (II) of each layer contain a plasticizer and a lubricant within a range not departing from the object of the present invention. , Heat stabilizer, light stabilizer, ultraviolet absorber, antioxidant, colorant, antistatic agent, surfactant,
Additives such as antibacterial agents and inorganic fillers can be blended, or other resins can be blended. In particular, a hydrotalcite-based compound, a hindered phenol-based, a hindered amine-based heat stabilizer, and a metal salt of a higher aliphatic carboxylic acid can also be added as a gel generation inhibitor.

Further, the resin composition (I) and the thermoplastic polyester resin (II) may be mixed with an oxygen absorbent to prevent oxygen from the outside of the multilayer container and remove residual oxygen inside. It is preferable in terms of improvement. Examples of the oxygen absorber include inorganic iron absorbers, reduced iron powders, and those obtained by adding a water-absorbing substance and an electrolyte thereto, aluminum powder, potassium sulfite, and photocatalytic titanium oxide. As, ascorbic acid or a fatty acid ester or metal salt thereof, hydroquinone, gallic acid, polyhydric phenols such as hydroxyl group-containing phenol aldehyde resin, bis-salicylaldehyde-imine cobalt, tetraethylene pentamine cobalt, cobalt-Schiff base complex, Porphyrins, macrocyclic polyamine complexes, coordination conjugates of nitrogen-containing compounds such as polyethyleneimine-cobalt complexes and transition metals, terpene compounds, reactants of amino acids and hydroxyl group-containing reducing substances, triphenylmethyl compounds, etc. Nitrogen-containing resin as a polymer-based oxygen absorbent Coordinate bond of the transition metal (eg MXD nylon and combinations cobalt), a blend of tertiary hydrogen-containing resin with a transition metal (e.g. a combination of polypropylene and cobalt),
A blend of a carbon-carbon unsaturated bond-containing resin and a transition metal (eg, a combination of polybutadiene and cobalt), a photo-oxidatively degradable resin (eg, a polyketone), an anthraquinone polymer (eg, a polyvinyl anthraquinone), and the like can be given. Further, it is also preferable to add a photoinitiator (such as benzophenone), a peroxide supplement (such as a commercially available antioxidant) and a deodorant (such as activated carbon) to these compounds.

The multilayer container of the present invention thus obtained can be used in addition to general foods, seasonings such as soy sauce, sauce, ketchup, mayonnaise, dressing, fermented foods such as miso, vinegar, oil and fat foods such as salad oil, and sake. , Beer, mirin, whiskey, shochu, wine and other alcoholic beverages, carbonated beverages, juices, sports drinks, milk, coffee beverages, oolong tea, black tea, mineral water, and other soft drinks, cosmetics, pharmaceuticals, detergents, cosmetics, industrial chemicals Although useful as a variety of containers such as pesticides, the multilayer container of the present invention is particularly beer, wine, carbonated drinks, juice, tea, milk, drinks such as coffee drinks, sauces, containers for seasonings such as dressing, It is especially useful for bottles formed by co-injection biaxial stretch blow molding.

[0061]

The present invention will be specifically described below with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.

For the measurement of the melting point and the heat of fusion ΔH of the polyamide resin, see the differential scanning calorimeter (PERKIN EL EL).
MER “Pyris1”) using 10 ° C heating rate
/ Min. Also, EVOH
The measurement of the boron content in the composition and the resin composition (I) was carried out by subjecting the EVOH composition and the resin composition (I) to alkali melting and quantifying the boron by ICP emission spectroscopy. Further, regarding the measurement of the alkali metal content, the EVOH composition or the resin composition (I) was incinerated, then dissolved in an aqueous hydrochloric acid solution, and the alkali metal was quantified by atomic absorption spectrometry. Regarding the measurement of the amount, the EVOH composition or the resin composition (I)
Was determined by quantifying the alkaline earth metal by ICP emission spectroscopy after incineration.

Example 1 EVOH [Ethylene content 34 mol%, saponification degree 99.
5 mol%, MFR 20 g / 10 min (210 ° C., load 21
Water / methanol (water / methanol = 40/60 mixing weight ratio) (A)
Extruded into a water tank maintained at 5 ° C. in the form of a strand and solidified, then cut with a cutter to form porous pellets (diameter 4 mm, length 4 mm).
VOH was obtained. Next, the obtained porous pellet-shaped E
After washing the VOH with water, it is poured into an aqueous solution containing 0.3% boric acid (C) and 0.1% sodium acetate (C), and
The mixture was stirred at about 4 ° C. for about 4 hours, and further dried at 75 ° C. for 3 hours by a batch column type fluidized bed drier and at 125 ° C. for 18 hours by a batch type aeration flow box drier to remove boric acid (C). 0.030 parts in terms of boron and 0.012 parts in terms of sodium of sodium acetate (C) [total amount of (C) is 0.1%.
042 parts] of the obtained EVOH composition (pellet).

Next, 90 parts of the composition (A + C) and a polyamide resin [Grillon CF6 manufactured by EMS Japan Co., Ltd.]
S ", nylon 6/12 copolymer, density 1.05 g /
cm ³ , melting point 133 ° C., ΔH51J / g, MFR 18 g
/ 10 min (210 ° C., load 2160 g)] (B) 10 parts were melt-kneaded with a twin-screw extruder under the following conditions, and the resin composition (I) [A / B ≒ 90 parts / 10 parts, A + B) 100
The mixing ratio of (C) per part is 0.038 part].

[Melting Pelletizing Condition by Twin Screw Extruder] Screw inner diameter 30 mm (L / D = 30) Screw shape Screen mesh having a kneading disk of 100 mm in compression part 90/90 mesh Screw rotation speed 150 rpm Vent hole Reduced pressure suction Execution Nitrogen gas was supplied in the hopper and replaced. Extrusion temperature C1: 190 ° C C2: 200 ° C C3: 210 ° C C4: 220 ° C C5: 220 ° C AD: 210 ° C D: 210 ° C

Using the resin composition (I) pellets obtained above and a thermoplastic polyester resin (polyethylene terephthalate, “BK2180” from Nihon Unipet) (II), a multilayer manifold system (KORTEC) is provided. Using an injection molding machine (manufactured by ARBURG), thermoplastic polyester resin (II) layer / resin composition (I)
Layer / multilayer parison of two types and three layers of thermoplastic polyester resin (II) (thickness configuration: [inside] 2.1 / 0.15 /
2.1 [outside] mm, outer diameter: 22 mm, height: 110 m
m) was produced by coinjection molding. After storing the obtained multilayer parison at room temperature for one day, the biaxial stretch blow molding machine (S
The multilayer parison is preheated while rotating it with an infrared heater using an infrared heater, and then biaxially stretch-blow-molded sequentially in the machine direction and the transverse direction to obtain an internal volume of 500.
A multilayer bottle (multilayer container) having a cc (outer diameter of the body portion of 65 mm, height of 250 mm) was obtained.

In addition, the main molding conditions were as follows. Resin composition (I) plasticization temperature: 190-200 ° C Thermoplastic polyester resin (II) plasticization temperature: 275-280 ° C Multilayer manifold system part temperature: 275 ° C Mold cooling temperature: 10 ° C Resin composition (I ) Injection pressure: 87.5 MPa Thermoplastic polyester resin (II) Injection pressure: 60 MPa Multilayer parison heating temperature: 110 ° C. Blow air pressure: 3.8 MPa The layer thickness configuration of the bottle body of the obtained multilayer bottle is [inside ] Thermoplastic polyester resin (II) / resin composition (I) / thermoplastic polyester resin (II) [outside] =
150/15/200 (μm).

The following evaluation was performed on the bottle. (Appearance) The obtained multilayer bottle was visually observed and evaluated as follows. However, the transparency was evaluated based on the degree of cloudiness of the multilayer bottle itself, and the transparency was evaluated based on the degree of distortion of characters as viewed from the opposite side by applying printed paper to the body of the multilayer bottle.・ ・ ・: Both transparency and transparency are good. 透明: Transparency is good but transparency is poor. X: Both transparency and transparency are poor.

(Oxygen Permeability) Bottle 1 under the conditions of a temperature of 23 ° C., a humidity of 100% RH inside the bottle, and a humidity of 50% outside the bottle
The oxygen permeability (cc / day) per unit is measured by an oxygen permeability measuring device (“OXTRAN10 / 50” manufactured by MOCON).
It measured using.

(Impact delamination resistance) Water (about 5
00cc), the mouth was sealed with a cap, and at 23 ° C. and 5 ° C., the body was horizontally leveled from a height of 1 m and dropped repeatedly on an iron floor surface 10 times each. The situation was visually observed and evaluated as follows. ◎ ・ ・ ・ No delamination was observed at all ○ ・ ・ ・ Very slight delamination was observed △ ・ ・ ・ Some delamination was observed × ・ ・ ・ Remarkable delamination was observed

Example 2 In Example 1, the ethylene content was 29 mol%, the saponification degree was 99.6 mol%, and the MFR was 12 g / 10 min (210 ° C.,
A total of 0.015 parts of sodium acetate (C) in terms of sodium and 0.007 parts of magnesium acetate (C) in terms of magnesium [(C) using EVOH (A) having a load of 2160 g) and a melting point of 188 ° C.] The amount is 0.022
Part], an EVOH composition (pellet) was prepared so as to contain, and the blend ratio with the polyamide resin (B) was changed to E.
The same procedure was repeated except that the VOH composition (A + C) was 85 parts and the polyamide resin (B) was 15 parts, and the resin composition (I) [A / B ／ 85 parts / 15 parts, (A + B) relative to 100 parts (A + B) ) Was 0.019 part]. Using the obtained resin composition (I), a multilayer container was obtained in the same manner as in Example 1, and the same evaluation was performed.

Example 3 In Example 1, the ethylene content was 36 mol%, the saponification degree was 99.6 mol%, and the MFR was 25 g / 10 min (210 ° C.,
EVOH (A) having a load of 2160 g) and a melting point of 177 ° C.], and 0.020 parts of boric acid (C) in terms of boron and 0.01% in terms of calcium of calcium acetate (C).
An EVOH composition (pellet) was prepared so as to contain 0 parts (the total amount of (C) was 0.030 parts), and the blend ratio with the polyamide resin (B) was adjusted to the EVOH composition (A +
C) The resin composition (I) [A / B ≒ 94 parts / 6] except that 94 parts and 6 parts of the polyamide resin (B) were used.
Of (C) per 100 parts of (A + B), 0.028 part]. Using the obtained resin composition (I), a multilayer container was obtained in the same manner as in Example 1, and the same evaluation was performed.

Example 4 In Example 1, the ethylene content was 34 mol%, the saponification degree was 99.7 mol%, the MFR was 12 g / 10 min (210 ° C.,
EVOH (A) having a load of 2160 g) and a melting point of 181 ° C.], and 0.012 parts of sodium acetate (C) in terms of sodium and 0.002 parts of magnesium stearate (C) in terms of magnesium [(C) The total amount is 0.014 parts], and an EVOH composition (pellet) is prepared so that the blend ratio with the polyamide resin (B) is 92 parts by weight of the EVOH composition (A + C) and the polyamide resin (B). A resin composition (I) [A / B ≒ 92 parts / 8 parts, the mixing ratio of (C) to 100 parts of (A + B) was 0.013 part) was obtained in the same manner except that the amount was changed to 8 parts. Using the obtained resin composition (I), a multilayer container was obtained in the same manner as in Example 1, and the same evaluation was performed.

Example 5 In Example 1, "Amilan CM8000" [nylon 6/66 /
610/12, a density of 1.12 g / cm ³ , a melting point of 131 ° C., ΔH of 40 J / g, MFR of 25 g / 10 min (210 ° C., load of 2160 g)]. ) [A / B ≒ 90 parts / 10 parts,
The mixing ratio of (C) to 100 parts of (A + B) is 0.0
38 parts]. Using the obtained resin composition (I), a multilayer container was obtained in the same manner as in Example 1, and the same evaluation was performed.

Example 6 In Example 2, “Grillon CA6E” [nylon 6 /
12 copolymer, density 1.06 g / cm ³ , melting point 124
° C, ΔH39J / g, MFR 26g / 10min (210
C., load 2160 g)], except that the resin composition (I) [A / B ≒ 85 parts / 15 parts, (A + B)
The mixing ratio of (C) was 0.019 parts with respect to 100 parts]. Using the obtained resin composition (I), a multilayer container was obtained in the same manner as in Example 1, and the same evaluation was performed.

Example 7 In Example 3, "Amilan CM6541-X3" [nylon 6 /
12 copolymer, density 1.11 g / cm ³ , melting point 135
° C, ΔH40J / g, MFR12g / 10min (210
, A load of 2160 g)], and the resin composition (I) [A / B ≒ 94 parts / 6 parts, (A + B) 1
The mixing ratio of (C) is 0.028 parts with respect to 00 parts]. Using the obtained resin composition (I), a multilayer container was obtained in the same manner as in Example 1 and evaluated in the same manner.

Comparative Example 1 A resin composition (A + C) was obtained in the same manner as in Example 1, except that the polyamide resin (B) was not contained in the resin composition (I). The evaluation was performed in the same manner.

Comparative Example 2 A resin composition (A + B) was obtained in the same manner as in Example 1, except that boric acid (C) and sodium acetate (C) were not contained in the resin composition (I). A multilayer container was obtained and evaluated similarly.

Comparative Example 3 In Example 1, instead of the polyamide resin (B),
Toray's “Amilan CM6541-X4” (nylon 6
/ 12 copolymer, density 1.10 g / cm ³ , melting point 19
6 ° C.) except that the resin composition (A + B ′ + C) was used.
Was obtained, a multilayer container was obtained in the same manner, and evaluation was performed in the same manner.

Table 1 summarizes the evaluation results of the examples and comparative examples.

[Table 1] Appearance Oxygen permeability * Impact delamination resistance 23 ° C 5 ° C Example 1 ○ 0.018 ◎ ◎ 〃 2 ○ 0.016 ◎ ◎ ３ 3 ○ 0.021 ◎ ◎ ◎ 4 ○ 0.017 ◎ ◎ ５ 5 ○ 0.018 ◎ ◎ 〃 6 ○ 0.016 ◎ ◎ 〃 7 ○ 0.021 ◎ ◎ Comparative Example 1 × 0.050 △ × 〃 2 △ 0.024 ○ × ３ 3 × 0 .042 ○ × * Unit is cc / day • atm (per multilayer bottle)

[0082]

According to the multilayer container of the present invention, a specific resin composition is used as an intermediate layer and thermoplastic polyester resin layers are used on both sides of the intermediate layer. Excellent in appearance, gas barrier properties, etc., very useful for containers for food and alcohol, beverages, cosmetics, pharmaceuticals, detergents, cosmetics, agricultural chemicals, industrial chemicals, especially beer, wine, carbonated drinks, juices, teas, Drinks such as milk and coffee drinks,
It is excellent for use in containers for seasonings such as sauces and dressings, and particularly for bottles formed by co-injection biaxial stretch blow molding.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B65D 1/09 C08K 3/38 C08K 3/38 5/098 5/098 C08L 29/04 S C08L 29/04 77/00 77/00 B29K 29:00 // B29K 29:00 67:00 67:00 B29L 22:00 B29L 22:00 B65D 1/00 BF term (reference) 3E033 AA20 BA17 BA21 BA24 BB04 BB08 CA09 CA16 CA18 FA03 4F100 AA40B AB09B AB40B AK41A AK41C AK46B AK48 AK69B AL05B BA03 BA06 DA01 GB16 GB23 GB66 JA04B JA20B JB16A JB16C JD02 JK06 JK10 JN01 4F208 AA19E AA19E AA24 AG03 AG07 LD03 LD03 LD01 LD06 LD06 LD06 EG036 EG046 GG01

Claims (5)

[Claims] 1. A saponified ethylene-vinyl acetate copolymer (A), a polyamide resin (B) having a melting point of 160 ° C. or less.
And a resin composition (I) containing at least one kind (C) selected from alkali metals, alkaline earth metals, and boron as an intermediate layer, and a thermoplastic polyester resin (II) layer on both sides thereof. A multilayer container characterized by comprising: 2. The weight ratio (A / B) of the saponified ethylene-vinyl acetate copolymer (A) and the polyamide resin (B) having a melting point of 160 ° C. or less in the resin composition (I) is 50.
2. The multilayer container according to claim 1, wherein the ratio is from 50/99 to 99/1. 3. The resin composition (I), wherein the content of at least one kind (C) selected from alkali metals, alkaline earth metals, and boron is a saponified ethylene-vinyl acetate copolymer (A) and the melting point is The multilayer container according to claim 1 or 2, wherein the amount is 0.001 to 1 part by weight based on 100 parts by weight of the total amount of the polyamide resin (B) at 160 ° C or lower. 4. The heat of fusion ΔH of the polyamide resin (B) having a melting point of 160 ° C. or less, measured using a differential scanning calorimeter (DSC) at a heating rate of 10 ° C./min, is 80 J /.
The multilayer container according to any one of claims 1 to 3, wherein g is equal to or less than g. 5. The multilayer container according to claim 1, which is formed by co-injection biaxial stretch blow molding.