JPH07144395A - Laminated wrapping material - Google Patents

Abstract

PURPOSE:To obtain a wrapping material with a fine gas barrier property, odor retainable property, heat-seaability, and rupture resistive strength by laminating a polyamide layer and a polyester composite layer of a specific copolymeric ethylene terephthalate and ethylene copolymeric ionomer blended at a specific rate. CONSTITUTION:For a polyamide layer, 6-nylon or 66-nylon is preferable to be used in consideration of a gas barrier property, rupture preventive strength, and so forth. Copolymeric polyethylene terephthalate is Induced by terephthalic acid, or a small quantity of a mixture with isophthalic acid, and ethylene glycol and cyclohexane dimethanol, and a mole rate of ethylene glycol and cyclohexane dimethanol is made 95-/5-75/25. Herein, a polyester composite layer consisting of 70-95 pts.wt. copolymeric polyethylene terephthalate and 5-30 pts.wt. ethylene copolymeric ionomer and a polymeric layer are laminated each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated packaging material which is excellent in gas barrier property and aroma retaining property and has high sealing strength and bag breaking strength when formed into a bag.

[0002]

2. Description of the Related Art It is already known that a polyethylene terephthalate (PET) resin having excellent aroma retaining property is suitable as a packaging material for foods and drinks and other substances containing aroma components. Copolymerized PET containing a small amount of a copolymerization component particularly for applications requiring heat sealability
Is preferable, and in applications where spreadability and impact resistance are required, it is effective to use a composition in which a small amount of an ethylene polymer is mixed with copolymerized PET.

[0003]

However, in such special applications as liquid pouches and bag-in-boxes, when such a composition is used, the bag breaking strength and heat sealing strength tend to be insufficient. In addition, the gas barrier property becomes lower than that of homo-PET due to the copolymerization or the incorporation of the ethylene polymer. Therefore, it has been desired to provide a material which is more excellent in gas barrier property, aroma retaining property, heat sealing property and bag breaking strength, which is suitable for the above use.

As a result of the study, the present inventors have found that a packaging material having desired physical properties can be provided by laminating two kinds of specific materials. Therefore, an object of the present invention is to provide a novel packaging material excellent in various physical properties such as gas barrier property, aroma retaining property, heat sealing property and bag breaking strength.

[0005]

The present invention provides a polyamide layer (A) and an aromatic dicarboxylic acid component consisting of terephthalic acid and optionally a smaller amount of isophthalic acid in a molar ratio of 95/5 to 75/25. Copolymerized polyethylene terephthalate derived from ethylene glycol and glycol component consisting of cyclohexanedimethanol 7
0 to 95 parts by weight and ethylene copolymer ionomer 5 to
The present invention relates to a laminated packaging material in which a polyester composition layer (B) consisting of 30 parts by weight is laminated.

The laminated packaging material of the present invention has a laminated structure of at least a polyamide layer (A) and a polyester composition layer (B).

As the polyamide forming the layer (A), nylon 6, nylon 66, nylon 11 and nylon 12 are used.
However, nylon 6 and nylon 66 are preferably used in consideration of the gas barrier property and the breaking strength.

As the copolymerized polyethylene terephthalate in the polyester composition layer (B), copolymerized polyethylene terephthalate derived from terephthalic acid and ethylene glycol and cyclohexanedimethanol or terephthalic acid and isophthalic acid, ethylene glycol and cyclohexanedimethanol. Copolymerized polyethylene terephthalate derived from and is used.

Such copolymerized polyethylene terephthalate also has an endothermic peak of 180 to 180 based on DSC.
It is preferably 240 ° C., particularly 190 to 230 ° C., and one having an endothermic amount of 10 to 40 Joules / g, particularly 15 to 35 Joules / g.

It is desirable that the molar ratio of ethylene glycol and cyclohexanedimethanol is 95/5 to 75/25, preferably 92/8 to 83/17. If the polymerization ratio of cyclohexanedimethanol is less than the above range, heat sealability, spreadability, and impact resistance are insufficient,
On the other hand, if the proportion exceeds the above range, the heat distortion resistance is deteriorated, which is not preferable.

When isophthalic acid is used, it is desirable that the amount of isophthalic acid is 10 mol% or less, preferably 5 mol% or less, based on the total carboxylic acid (terephthalic acid + isophthalic acid). If the isophthalic acid content is too high, the cyclohexanedimethanol content must be reduced in order to obtain a copolymerized polyethylene terephthalate having an endothermic peak of 180 to 240 ° C. and an endothermic amount of 10 to 40 joules. The resulting copolymerized polyethylene terephthalate may not always have satisfactory spreadability and impact resistance.

The copolymerized polyethylene terephthalate of the present invention may contain a small amount of a dicarboxylic acid other than terephthalic acid and isophthalic acid such as 2,6-naphthalenedicarboxylic acid as a dicarboxylic acid component, and ethylene as a diol component. A small amount of diol other than glycol and cyclohexanedimethanol, such as diethylene glycol, may be contained.

The copolymerized polyethylene terephthalate according to the present invention can be produced by a conventionally known method such as a transesterification method or a direct polymerization method.

The ethylene copolymer ionomer used as the other component of the layer (B) is an ionomer in which at least a part of the carboxyl groups of the ethylene-unsaturated carboxylic acid copolymer is neutralized with a metal cation. is there.

The ethylene-unsaturated carboxylic acid copolymer constituting the ethylene copolymer ionomer used in the present invention is a copolymer of ethylene and an unsaturated carboxylic acid. The unsaturated carboxylic acid is An unsaturated carboxylic acid having 3 to 8 carbon atoms, specifically acrylic acid, methacrylic acid, fumaric acid, itaconic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monoethyl ester, or the like is used. Among these unsaturated carboxylic acids, acrylic acid, methacrylic acid and maleic anhydride are particularly preferably used.

The ethylene-unsaturated carboxylic acid copolymer used in the present invention may contain a third component in addition to ethylene and the above-mentioned unsaturated carboxylic acid. As such a third component, Is a polar vinyl compound having about 3 to 12 carbon atoms such as methyl acrylate, ethyl acrylate, i-butyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, unsaturated carboxylic acid ester such as methyl methacrylate, A vinyl ester such as vinyl acetate is used.

In the ethylene-unsaturated carboxylic acid copolymer used in the present invention, ethylene is present in an amount of 60 to 99% by weight, preferably 70 to 99% by weight, and the unsaturated carboxylic acid is 1 to 30% by weight. %, Preferably 2 to 20% by weight
Is preferably present in an amount of.

When the ethylene-unsaturated carboxylic acid copolymer contains a third component in addition to the ethylene component and the unsaturated carboxylic acid component, the third component is up to 39% by weight,
It is preferably present in an amount of up to 30% by weight.

In the ionomer used in the present invention, at least a part of the carboxyl groups in the above ethylene-unsaturated carboxylic acid copolymer is neutralized with a metal cation. Such metal ions include Na ⁺ , K
⁺ , Li ⁺ , Ca ²⁺ , Mg ²⁺ , Zn ²⁺ , Cu ²⁺ , C
Examples thereof include monovalent to trivalent metal cations such as o ²⁺ , Ni ²⁺ , Mn ²⁺ and Al ³⁺ . Of these, especially Zn ²⁺ ,
Divalent ions such as Mg ²⁺ are preferable, and when an ionomer containing these divalent ions is used, crystallization of the copolymerized polyethylene terephthalate is not promoted, and therefore the heat-sealing property does not change with time and spreads. A polyester composition having excellent properties and impact resistance can be obtained.

In general, such an ionomer is obtained by copolymerizing ethylene, an unsaturated carboxylic acid and, if necessary, a third component into an ethylene-unsaturated carboxylic acid copolymer. At least a part of the carboxyl group of the copolymer is neutralized with a metal ion, or ethylene is copolymerized with an unsaturated carboxylic acid ester and, if necessary, a third component, and the copolymer obtained It can be obtained by saponifying at least a part of the saturated carboxylic acid ester component.

In particular, in the present invention, a copolymer obtained by copolymerizing ethylene, an unsaturated carboxylic acid and, if necessary, a third component by a high pressure radical polymerization method is used as a base, and one of the carboxyl groups of this copolymer is used. An ionomer whose part or all is neutralized with a metal cation is preferably used. The degree of neutralization is usually 5 to 100%, preferably about 10 to 90%. The melting point of such an ionomer is generally about 70 to 105 ° C. The melt flow rate (MFR) of the ionomer measured at 190 ° C. under a load of 2160 g is 0.01 to 1000 dg / min.
It is particularly preferably 0.1 to 200 dg / min.

The copolymerized polyethylene terephthalate and the ionomer are 70 to 95 parts by weight of the copolymerized polyethylene terephthalate when the total amount is 100 parts by weight,
Preferably, the amount of ionomer is 5 to 80 parts by weight.
It is desirable to use in an amount of -30 parts by weight, preferably 10-20 parts by weight. When the amount of the ionomer used is too small, the resulting polyester composition has insufficient impact resistance and spreadability, and when the amount used is too large, the heat resistance and aroma retention of the obtained polyester composition are impaired. May be

The polyester composition for the layer (B) may contain a small amount of a non-polar ethylene polymer or copolymer in addition to the copolymerized polyethylene terephthalate and the ethylene copolymer ionomer as described above. A polyester packaging material comprising such a polyester composition containing an ethylene (co) polymer is excellent in heat sealability and processability.

The ethylene polymer may be a homopolymer of ethylene or a copolymer of ethylene and an α-olefin having about 3 to 12 carbon atoms, such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene. Polymers may be mentioned. Of these, linear low density polyethylene is particularly preferable.

Such an ethylene polymer is a copolymer of polyethylene terephthalate and ionomer in a total amount of 100.
It is preferably used in an amount of 10 parts by weight or less, preferably 1 to 5 parts by weight, based on parts by weight.

Additives such as antioxidants may be added to the polyester composition. Particularly, a hindered phenol stabilizer known under the trade name Irganox 1010, 1076 and the like is added in an amount of 0.05 to 1.
By blending about 0 parts by weight, particularly preferably about 0.2 to 1.0 parts by weight, yellowing of the composition can be prevented and impact resistance can be improved. Excellent heat sealability can be maintained by blending.

Lamination of the polyamide layer (A) and the polyester composition layer (B) is usually carried out via a suitable adhesive. As the adhesive used for this purpose, a copolymer obtained by graft-modifying at least a part of an ethylene copolymer having an ethylene content of 70 to 95% by weight with an unsaturated carboxylic acid or an anhydride thereof. Polymer component (C ₁ ) 70 to 9 consisting of a component and optionally low-density polyethylene
It is preferable to use the ethylene polymer composition layer (C) comprising 5 parts by weight and 5 to 30 parts by weight of the tackifying resin (C ₂ ).

As the (C ₁ ) component, for example, the following can be used. (1) An ethylene copolymer grafted with an unsaturated carboxylic acid or an anhydride thereof. (2) A blend of (1) and an unmodified ethylene copolymer. In this case, the ethylene copolymer as the raw material of (1) and the unmodified ethylene copolymer are the same or different. (3) A blend of (1) or (2) and low density polyethylene.

The ethylene copolymer preferably has an ethylene content of 70 to 95% by weight, and is particularly preferably an α-olefin having a carbon number of 3 or more or a (meth) acrylic acid ester as a copolymerization component. Examples of the α-olefin include propylene, 1-butene, 1-hexene, 1-octene, 1-decene, and 4-methyl-1-pentene, and examples of the (meth) acrylic acid ester include methyl acrylate. , Ethyl acrylate, isobutyl acrylate, n-butyl acrylate, methyl methacrylate, isobutyl methacrylate and the like.

As the unsaturated carboxylic acid or its anhydride grafted on the ethylene copolymer, acrylic acid, methacrylic acid, fumaric acid, norbornene-2,3-
Examples thereof include dicarboxylic acid or its anhydride, maleic anhydride, and itaconic anhydride. Of these, maleic anhydride is particularly preferable.

The amount of the grafted unsaturated carboxylic acid or its anhydride in the polymer component (C ₁ ) is
Considering the adhesiveness to both layers (A) and (B), it is desirable to adjust the amount to about 0.01 to 2% by weight. Therefore, when the graft copolymer is diluted and used as in the above embodiments (2) and (3), the graft amount of the graft copolymer is adjusted to 0.
It is preferably from 0.3 to 7% by weight, particularly preferably from 0.05 to 5% by weight.

Although various ethylene copolymers can be used as the polymer component (C ₁ ), considering the adhesiveness to both layers (A) and (B), at least 10% by weight in (C ₁ ). % Or more, preferably 15% by weight or more, it is preferable to use a low crystalline or amorphous ethylene / α-olefin copolymer. In addition to the adhesiveness to both layers (A) and (B), when importance is attached to heat resistant adhesiveness,
The low crystalline or amorphous ethylene / α-olefin copolymer in (C ₁ ) is 10 to 50% by weight, preferably 15 to 40% by weight, and the remainder is crystalline ethylene.
α-olefin copolymer (linear low-density polyethylene),
It is preferable to select from ethylene / (meth) acrylic acid ester copolymer or low density polyethylene. In any case, it is desirable to use a low crystalline or amorphous ethylene / α-olefin copolymer as the ethylene copolymer used for grafting. The low crystalline or amorphous ethylene / α-olefin copolymer has a crystallinity based on an X-ray diffraction method of 30% or less, preferably 20% or less and a density of 0.900 g / cm 3.
Less than ^3, preferably 0.860~0.895g / cm ³
belongs to. Further, propylene or 1-butene is preferable as the α-olefin in the copolymer.

On the other hand, as the above-mentioned crystalline ethylene / α-olefin copolymer (linear low density polyethylene), the crystallinity based on the X-ray diffraction method is 40% or more and the density is 0.900 to 0. 0.940 g / cm ³ , preferably 0.
905 to 0.930 g / cm ³ . The α-olefin in the copolymer preferably has 4 or more carbon atoms.

The ethylene / (meth) acrylic acid ester copolymer has a (meth) acrylic acid ester content of 5 to 30% by weight, particularly 10 to 25% by weight, in consideration of processability and adhesiveness. It is preferable to use one of the following.

These ethylene copolymers or low-density polyethylenes have a workability of 190 ° C., 21
Melt flow rate under load of 60g is 0.1-50
It is preferable to use g / 10 min, especially about 0.2 to 30 g / 10 min.

As the tackifying resin (C ₂ ) which is a constituent of the ethylene polymer composition (C), an aliphatic hydrocarbon resin, an alicyclic hydrocarbon resin, an aromatic hydrocarbon resin,
Examples thereof include polyterpene-based resins, rosins, styrene-based resins, coumarone, and indene resins.

Examples of the aliphatic hydrocarbon resin include 1-
Examples of the polymer include butene, isobutylene, butadiene, 1,3-pentadiene, isoprene, piperylene, and other C _{4 to} C ₅ mono- or diolefin-based polymers. Examples of alicyclic hydrocarbon resins include Spent C ₄
To a resin obtained by polymerizing a diene component in a C ₅ fraction after cyclization and dimerization, a resin obtained by polymerizing a cyclic monomer such as cyclopentadiene, a resin obtained by hydrogenating an aromatic hydrocarbon resin in a nucleus, and the like. Can be mentioned. Examples of aromatic hydrocarbon resins, vinyl toluene, indene, like C ₈ -C ₁₀ resin composed mainly of a vinyl aromatic hydrocarbon, such as α- methyl styrene. Examples of polyterpene resins include α-pinene polymers, β-pinene polymers, dipentene polymers, terpene-phenol copolymers, α-pinene-
Examples thereof include phenol copolymers. Rosin is a rosin such as gum rosin, wood rosin, tall oil and its modified products, and as modified products, hydrogenation, disproportionation,
Examples thereof include those that have been subjected to modification means such as dimerization and esterification. The styrene-based hydrocarbon resin is a polymer such as styrene, vinyltoluene, α-methylstyrene and isopropenyltoluene. The tackifying resin exemplified above may be graft-modified with maleic anhydride, maleic acid ester or the like.

Among these tackifying resins, (C ₁ )
From the viewpoint of compatibility with the components, it is preferable to use an aliphatic hydrocarbon resin or an alicyclic hydrocarbon resin.

(C in the ethylene polymer composition (C)
The compounding ratio of the ₁ ) component and the (C ₂ ) component is 70-95 of the former.
5 parts by weight, preferably 75 to 90 parts by weight, the latter 5 to
It is 30 parts by weight, preferably 10 to 25 parts by weight. If the usage ratio of the former is less than the above range, the adhesive strength at high temperature will be small, and if the usage ratio is more than the above range, the adhesive strength at room temperature will be small and the optical characteristics will be poor.

The laminated packaging material of the present invention can be advantageously produced by a coextrusion method. The thickness of each layer is arbitrary, but is 10 to 200 μm, and particularly 20 to 100 μm.
A range of m is desirable.

The laminated packaging material of the present invention has the above-mentioned layer (A).
In addition to (B) and (C), another layer may be provided for the purpose of improving light-shielding properties and curling properties. In any case, the laminated packaging material of the present invention is used in the form of use such that the polyester composition layer (B) is the innermost layer.

[0042]

EFFECTS OF THE INVENTION The laminated packaging material of the present invention is excellent in gas barrier property, aroma retaining property, heat sealing property, bag breaking strength and the like due to the above-mentioned constitution. Therefore, by utilizing such characteristics, it can be used as a packaging container of various shapes. In particular, it can be suitably used for liquid pouches, bag-in-boxes and the like that require high performance. Also, as the material to be packaged, it is desirable to avoid reduction of aroma components, such as juice,
Suitable for detergents, various oily substances, and packaging materials such as mineral water that do not like odor transfer.

[0043]

【Example】

[Example 1] (1) Production of copolymerized polyethylene terephthalate Using terephthalic acid as a dicarboxylic acid component, ethylene glycol 91 mol% and 1,4 as a diol component
-Copolymerized polyethylene terephthalate was produced by transesterification using 9 mol% cyclohexanedimethanol. The endothermic peak measured by DSC for 5 hours at 130 ° C. in a nitrogen atmosphere for 5 hours in a nitrogen atmosphere at a temperature rising rate of 10 ° C./min is 230 ° C., and the endothermic amount is 31 J / g.

(2) Preparation of copolymerized polyethylene terephthalate composition (1) 82% by weight of the copolymerized polyethylene terephthalate obtained in (1) above, and (2) Zn ionomer of ethylene-methacrylic acid copolymer (methacrylic acid 15% by weight, Zn neutralization degree 60%) ... 15% by weight (3) Linear low density polyethylene (density 0.920 g / cm ³ , MFR 20 dg / min) 3% by weight Each was sufficiently dried with heated nitrogen, melt-kneaded at 260 ° C. in a 44 mmφ biaxial kneader in the same direction, and then granulated to prepare a pelletized polyester composition. At the time of this mixed granulation, 0.4 part by weight of Irganox 1010 (trade name, manufactured by Ciba-Geigy, antioxidant) was added per 100 parts by weight of the above composition. This polyester composition was used as the resin for layer B.

(3) Manufacture of resin for C layer Ethylene / 1-butene copolymer having 1-butene content of 15 mol% (EBR, crystallinity 10%, MFR 3.5)
g / 10 minutes) 100 parts by weight of maleic anhydride (MAH)
0.5 parts by weight and 0.10 parts by weight of 2,5-dimethyl-2,5-di (tertiarybutylperoxy) hexane-3 as a radical polymerization initiator were added, and this mixture was extruded (40 mmφ extrusion). Machine, L / D = 28, denaturation temperature 200
~ 240 ° C, screw rotation speed 40 / min),
A maleic anhydride graft-modified ethylene / 1-butene copolymer was synthesized.

30% by weight of this maleic anhydride-modified product and linear low-density polyethylene (ethylene 4-methyl-1-pentene copolymer, density 0 910 g / cm ³ , MFR 2 g / 10 min) ... 55 wt% and hydrogenated petroleum resin (Arakawa Chemical Co., Alcon P-125) ... .. 15% by weight is premixed and fed to a 65 mmφ single screw extruder.
Melt-mix granulation was performed at 0 ° C. This composition was used as a C layer resin.

(4) A layer polyamide resin nylon 6 ((manufactured by Toray Industries, Inc., CM1021, melt viscosity
3200 poise (270 ° C)) was used.

(5) Preparation of Laminated Film The above resins A, B, and C were supplied to a three-layer cast film molding machine with layer C as an intermediate layer, and a three-layer film was obtained using a feed block. The film forming conditions are as shown in Table 1.

[0049]

[Table 1] Film forming speed: 15 m / min Total thickness of film and thickness ratio Total thickness: 110 μm Thickness ratio of each film layer: A / C / B = 45/15/4
0

(6) Measurement of oxygen gas permeability With respect to this laminated film, the Modern Contr
ols, Inc. Oxygen gas permeability was measured by OXTRAN-TWIN manufactured by the company. The results are shown in Table 2.

(7) Measurement of heat seal strength Further, the layer B surfaces of this laminated film were heat sealed with a bar sealer manufactured by Toyo Seiki Co., Ltd., and the peel strength was measured. The results are shown in Table 2.

(8) Measurement of bag-breaking strength Further, using this laminated film, a pouch of 170 mm × 170 mm was prepared so that the layer B surface was the inner surface, and water 200
filled with cc. This pouch was repeatedly dropped from a certain height and the number of times until the pouch broke was measured. The results are shown in Table 3.

(9) Measurement of static load pressure strength Further, the static load pressure strength of this pouch was measured by a static load pressure tester manufactured by Northern Cross. The results are shown in Table 3.

(10) Measurement of Fragrance Retention Further, using this laminated film, a pouch of 150 mm × 150 mm was prepared so that the layer B surface was the inner surface, and 100
% Fruit juice 150 ml of orange juice was hot-filled at 80 ° C. and sealed. The amount of d-limonene in the juice after storing this at 23 ° C. for a predetermined time was measured by HEWLETT PAC.
It was quantified by KAR gas chromatography. For the blank, juice before filling which was heat-treated at 80 ° C. was used.
The results are shown in Table 4.

Example 2 97 mol% of terephthalic acid and 3 mol% of isophthalic acid were used as dicarboxylic acid components, and 84 mol% of ethylene glycol was used as a diol component.
And 1,4-cyclohexanedimethanol 16 mol%
Copolyethylene terephthalate produced by using (a sample heated at 130 ° C. for 5 hours in a nitrogen atmosphere was DS
The endothermic peak measured at C at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere is 199 ° C., and the endothermic amount is 29 Joule / g. Was used in the same manner as in Example 1 to prepare a laminated film having a total thickness of 110 μm, and evaluated the physical properties. The results are shown in Tables 2 to 4.

[Comparative Example 1] The same procedure as in Example 1 was carried out except that a linear low-density polyethylene having an MFR of 2.1 g / 10 min and a density of 0.930 g / cm ³ was used as the resin for the layer A in Example 1. A laminated film having a total thickness of 110 μm was prepared and its physical properties were evaluated. The results are shown in Tables 2-3.

[Comparative Example 2] As the resin for the layer B in Example 1, a modified polyethylene terephthalate (isophthalic acid / terephthalic acid / ethylene glycol = 14 /, in which the glycol component was composed of only ethylene glycol and 14 mol% of isophthalic acid was contained). 86/100 molar ratio), A,
For the C layer, the same resin as in Example 1 was used, and in the same manner as in Example 1, a laminated film having a total thickness of 110 μm was prepared, and the drop bag test and static load strength were evaluated. The results are shown in Table 3.

Comparative Example 3 A total thickness of 110 μm was obtained in the same manner as in Example 1 except that as the resin for the B layer in Example 1, low density polyethylene having MFR 8.0 g / 10 min and density 0.917 g / cm ³ was used. A laminated film of was prepared and the flavor barrier property was evaluated. The results are shown in Table 4.

[0059]

[Table 2] Oxygen permeability and heat seal strength

[0060]

[Table 3] Drop bag test and static load strength

[0061]

[Table 4] d-limonene flavor Barrier property (d
-Limonene retention rate)

As is clear from the above results, by laminating two kinds of specific materials, a laminated packaging material having excellent gas barrier property and aroma retaining property and having a large sealing strength and bag breaking strength when formed into a bag is obtained. be able to.

Claims (4)

[Claims] 1. A polyamide layer (A) and an aromatic dicarboxylic acid component comprising terephthalic acid and optionally a smaller amount of isophthalic acid, in a molar ratio of 95/5 to 75/25.
A polyester composition layer (B) consisting of 70 to 95 parts by weight of a copolymerized polyethylene terephthalate derived from ethylene glycol and a glycol component consisting of cyclohexanedimethanol in an amount of 5 to 30 parts by weight, and an ethylene copolymer ionomer of 5 to 30 parts by weight. A laminated packaging material formed by laminating. 2. The polyester composition contains 10 parts by weight or less of a nonpolar ethylene polymer or copolymer with respect to 100 parts by weight as a total of copolymerized polyethylene terephthalate and an ethylene copolymer ionomer. The laminated packaging material according to claim 1. 3. The laminated packaging material according to claim 1, wherein the ethylene copolymer ionomer is a divalent metal ionomer. 4. The polyamide layer (A) and the polyester composition layer (B) have an ethylene content of 70 to 95% by weight, at least a part of an ethylene copolymer being an unsaturated carboxylic acid or an anhydride thereof. 70 to 95 parts by weight of a polymer component (C ₁ ) consisting of a copolymer component graft-modified with C and optionally low-density polyethylene, and a tackifying resin (C
₂ ) The laminated packaging material according to claims 1 to 3, which is laminated via an ethylene polymer composition layer (C) consisting of 5 to 30 parts by weight.