JPS63290742A - Laminated material having excellent properties in holding fragrance - Google Patents

Abstract

PURPOSE:To improve thermal sealing strength and shock-proof strength, by laminating a linear saturated polyester resin layer surface out of a laminated resin layer on a packaging base material so that the same becomes the outermost layer. CONSTITUTION:A linear saturated polyester resin layer constituting one side outermost layer of a laminated material possesses the glass transition temperature of 40 deg.C or higher, and a co-condensation polymer of ethylene glycol and terephthalic acid or the ethylene glycol, isophthalic acid and the terephthalic acid can be used for the title laminated material. Ethylenic unsaturated carboxylic acid or ethylenic unsaturated anhydrous carboxylic acid is used suitably for adhesive polyolefin resin which is used as an adhesive agent layer. Then a linear saturated polyester resin layer whose glass transition temperature is 40 deg.C or higher and polyolefin resin layer based on ethylene-alpha- olefin copolymer are stuck together with the adhesive agent layer based on the adhesive polyolefin resin, in a laminated resin layer. As the laminated resin layer is high in the shock-proof strength and possesses, moreover, excellent properties in thermal adhesive capacity, a thermal adhesion part displays excellent properties. Therefore, excellent shock resistance is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laminated material used for, for example, container bodies, container bottoms, container lids, packaging bags, and the like.

[Conventional technology]

Conventional laminated materials used for container bodies, container bottom materials, container lid materials, packaging bags, etc. for containers containing various liquid foods and beverages, tea leaves, spices, etc. have polyolefin resin layers on both surface layers. These polyolefin resin layers are generally formed into containers and packaging bags of various shapes by taking advantage of their thermal adhesion properties.

[Problem that the invention seeks to solve]

By the way, for containers and packaging bags in which the conventional laminate material in which both surface layers are composed of polyolefin resin layers is used, for example, as a container body, a container bottom material, a container lid material, etc., it is difficult to obtain the laminate material. When forming a polyolefin resin layer or molding a container or packaging bag using the laminated material, the polyolefin resin undergoes thermal decomposition and generates volatile components such as aliphatic hydrocarbons. As a result of the sexual components migrating into the filling material contained in the container or packaging bag, not only does the filling material have the disadvantage of producing a strange taste or odor, but the polyolefin resin layer in the laminated material However, since the flavoring components in the filler are easily adsorbed or permeable, the flavor of the filler is easily changed and spoiled.

In order to improve the above-mentioned drawbacks of the polyolefin resin layer, a laminate material is provided in which a polyethylene terephthalate resin layer, which generates less volatile substances and has good fragrance retention, is formed as an inner layer. Although it has been proposed,
A single polyethylene terephthalate resin layer has poor heat sealing strength and impact strength, making it difficult to put it into practical use.

Furthermore, JP-A No. 60-48344 describes that impact resistance is improved by using a polyester film on which a polyolefin resin layer is laminated as a heat-sealing layer. The actual situation is that sufficient effects are not obtained because the adhesive strength between the layer and the polyester film is insufficient.

In contrast, the present invention provides a laminated material in which both of the conventional surface layers are composed of polyolefin resin layers, a packaging material having a single layer of polyethylene terephthalate resin, and a laminated material in which both surface layers are composed of polyolefin resin layers. This product eliminates all the drawbacks of laminated materials that use polyester film as a heat-sealing layer, such as the occurrence of strange tastes and odors in the contents of containers and packaging bags made of laminated materials. In addition, sufficient thermal bonding can be achieved by a molding method that is exactly the same as the conventional thermopressure bonding molding applied to the above-mentioned laminate materials, that is, by a molding method that utilizes the thermal bonding ability of the resin layer in the laminate material. The present invention provides a laminated material that can be formed into various strong containers, packaging bags, and the like.

[Means for solving problems]

The laminated material of the present invention having excellent fragrance retention properties is composed of a base material for packaging material and a thermoplastic resin layer attached to one side of the base material for packaging material, The resin layer includes a linear saturated polyester resin layer having a glass transition temperature of 40° C. or higher, and an ethylene-α bonded to the linear saturated polyester resin layer by an adhesive layer made of an adhesive polyolefin resin. - A laminated resin layer consisting of a polyolefin resin layer made of an olefin copolymer, and the linear saturated polyester resin layer surface of the laminated resin layer is the outermost layer of the laminated material, and is attached to the packaging material base material. It is made of laminated materials.

The linear saturated polyester resin layer constituting one of the outermost layers of the laminate of the present invention exhibits excellent fragrance retention performance at a temperature below the glass transition temperature of the polyester resin constituting the polyester resin layer. Therefore, in relation to the fact that the contents inside containers and packaging bags are normally placed in an atmosphere below 40°C, the polyester resin layer has excellent fragrance retention in the above atmosphere. It is made of a linear saturated polyester resin having a glass transition temperature of 40° C. or higher to ensure performance.

In addition, the polyester resin in the linear saturated polyester resin layer constituting the one outermost layer has a relationship that excellent thermal adhesive strength can be obtained in the thermal adhesive part of the container or packaging bag obtained by the laminated material of the present invention. Therefore, it is preferable to use a resin with as low crystallinity as possible. The linear saturated polyester resin having a glass transition temperature of 40° C. or higher and constituting the one outermost layer is, for example, ethylene glycol or propylene glycol.

Alcohol components such as 1.4-butanediol and 1.4-dicyclohexane dimetatool, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, and aromatic dicarboxylic acids such as terephthalic acid, inphthalic acid, and diphenylcarboxylic acid. dicarboxylic acid components, specifically ethylene glycol and terephthalic acid, ethylene glycol and isophthalic acid and terephthalic acid, l,4-dicyclohexanedimetatool, isophthalic acid and terephthalic acid.

A cocondensation polymer of propylene glycol, isophthalic acid, terephthalic acid, etc. can be used, but in the case of a cocondensation polymer in which the aliphatic dicarboxylic acid component in the acid component is 10% by weight or more, saturation with this copolymer is required. A polyester resin layer is not preferable because its fragrance retention performance tends to decrease.

In the laminated resin layer in the laminated material of the present invention, the adhesive polyolefin resin used as the adhesive layer is, for example, polyethylene, ethylene-α/olefin copolymer, or polypropylene.

In addition to polyα-olefins such as polybutene and polyisobutylene, and polydiolefins such as polybutadiene and polyisoprene, or copolymers thereof, ethylene and carboxylic acids, carboxylic acid salts, carboxylic acid anhydrides, carboxylic acid esters, etc. Potassium (-C4EN) group based on carboxylic acid amide or imide, aldehyde, ketone, etc.; Hydroxy group: Ether group;
C- A copolymer with one or more ethylenically unsaturated monomers in combination with a xylan (\/ ) ring, etc., specifically: A, ethylenically unsaturated carboxylic acid Niacrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, 5-norbornene-2,3-dicarboxylic acid, etc. B, ethylenically unsaturated carboxylic anhydride: maleic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, tetrahydrophthalic anhydride, etc., ethylenically unsaturated esters: ethyl acrylate, methyl methacrylate, acrylic acid 2
-Ethylhexyl, mono- or diethyl maleate, vinyl acetate, vinyl propionate, propyl γ-hydroxy methacrylate, ethyl β-hydroxy acrylate, glycidyl acrylate, glycidyl methacrylate, β-
Ethylenically unsaturated amides or imides such as N-ethylaminoethyl acrylate: acrylamide, methacrylamide, maleimide, etc.E, ethylenically unsaturated aldehydes or ketones: ethylene such as acrolein, methacrolein, vinyl methyl ketone, vinyl butyl ketone, etc. A series of unsaturated monomers are used, and among them, an ethylenically unsaturated carboxylic acid or an ethylenically unsaturated carboxylic anhydride is particularly preferably used.

The laminated resin layer has the above-mentioned linear oversaturated ester resin layer having a glass transition temperature of 40° C. or higher and the polyolefin resin layer made of an ethylene-α-olefin copolymer bonded together by the above-mentioned adhesive polyolefin resin. The polyolefin resin layer made of the ethylene-α-olefin copolymer that is adhered to the linear saturated polyester resin layer has high impact strength,
In addition, it has excellent thermal adhesion performance, so in the laminated resin layer, either the linear saturated polyester resin layer with low impact strength or the ethylene resin layer with high impact strength is used.
As a result of being covered with a polyolefin resin layer made of an α-olefin copolymer, the thermally bonded portion obtained by the laminated resin layer exhibits extremely excellent properties in both impact strength and thermal bonding strength. .

The polyolefin resin layer made of the ethylene-α-olefin copolymer is, for example, an ethylene-α-olefin copolymer using α-olefins such as butene arches, pentene arches, hexene arches, methylbutene-1, etc. It is something that is formed.

The laminate material of the present invention is a laminate comprising a linear saturated polyester resin layer having a glass transition temperature of 40° C. or higher, an adhesive layer made of an adhesive polyolefin resin, and a polyolefin resin layer made of an ethylene-α/olefin copolymer. The resin layer is attached to the packaging material base material, and the adhesion between the packaging material base material surface and the polyolefin resin layer in the laminated resin layer is due to the heat possessed by the polyolefin resin layer. υ pasted with adhesive ability, or by oxidizing the surface of the polyolefin resin layer. be. The base material for packaging materials on which this laminated resin layer is laminated is, for example, when used as a laminated material for flexible packaging containers such as stand pouches, generally consisting of AX foil and biaxially oriented polyester film or biaxially oriented polyester film. When making a laminated sheet with stretched polypropylene film, etc., or as a laminated material for containers such as gable-top paper containers and brick-shaped paper containers, Affi foil is generally used with 9 paper layers.

A laminated sheet composed of a polyolefin resin layer or the like is used.

〔Example〕

Hereinafter, the specific structure of the laminated material having excellent fragrance retention properties according to the present invention will be explained with reference to illustrated examples.

Example 1 An example product of the laminated material having excellent fragrance retention properties of the present invention, indicated by reference numeral 1 in FIG. 1, has a thickness of 12 μm.
A laminated resin layer indicated by reference numeral 8 is laminated on a base material 4 for packaging material consisting of a laminated sheet of a biaxially oriented polyethylene terephthalate film layer 2 and a 9μ thick A2 foil 3. , the laminated resin layer 8 is composed of a polyester resin layer 5 having a thickness of 15 μm formed of a linear saturated polyester resin (manufactured by Eastman Kodak ■: PETG6763) having a glass transition temperature of 81° C., and an ethylene-pente/. A 40 μm thick polyolefin resin layer 6 made of a polymer (Mitsui Petrochemical Co., Ltd.: Urtozex 2021L) is layered with a 15 μm thick polyolefin resin layer 6 made of an adhesive polyolefin resin (Mitsubishi Kasei Co., Ltd. Nippertic AP AX-133E).
The packaging material base material 4 and the laminated resin layer 8 are made of A22 foil 3 in the base material 4 and polyolefin resin in the laminated resin layer 8. The six layers are adhered and laminated by an isocyanate adhesive layer 9.

Comparative Example 1 An incyanate-based adhesive was applied to the AIt foil surface of a packaging material base material consisting of a laminated sheet of a biaxially oriented polyethylene terephthalate film layer with a thickness of 12μ and an A2 foil with a thickness of 9μ. Ethylene-pentene 1 copolymer (manufactured by Mitsui Petrochemicals: Urtozex 2021L)
K! A laminate material (A) for comparison was obtained by forming a polyolefin resin layer with a thickness of 70 μm.

Comparative Example 2 For a packaging material base material having the same configuration as the packaging material base material 4 used in Example 1, an incyanate adhesive was applied to the A2 foil surface of the base material to increase the glass transition temperature. Linear saturated polyester resin at 81°C [manufactured by Eastman Kodak ■: PE
A laminate material CB) for comparison was obtained by forming a polyester resin layer with a thickness of 70 μm using TG6763).

Comparative Example 3 For a packaging material base material having the same configuration as the packaging material base material 4 used in Example 1, an incyanate adhesive was applied to the A2 foil surface of the base material to increase the glass transition temperature. Linear saturated polyester resin at 81°C [manufactured by Eastman Kodak ■: PE
A laminated resin layer consisting of a 15 μm thick polyester resin layer made of TG 6763) and a 55 μm thick adhesive layer made of an adhesive polyolefin resin (Nippertic AP AX-133E manufactured by Mitsubishi Kasei) is made of polyester resin in the laminated resin layer. A laminated material (C) for comparison was obtained by adhering and laminating the resin layer as the outermost layer.

Comparative Example 4 For a packaging material base material having the same configuration as the packaging material base material 4 used in Example 1, an isocyanate-based adhesive was applied to the second foil surface of the base material to achieve a glass transition temperature of 81. 'C Linear Saturated Polyester Resin [Manufactured by Eastman Kodak ■: PE
TG 6763) 15μ thick polyester resin layer and ethylene-vinyl acetate copolymer [Sumitomo Chemical ■
Manufactured by: Evatate D3'022. A laminated resin layer with a polyolefin resin layer having a thickness of 55 μm with acetic acid content of 6%] was bonded so that the polyester resin layer in the laminated resin layer was the outermost layer.

By laminating, a laminated material CD) for comparison was obtained.

〔experiment〕

Using each of the above-mentioned example product of the laminated material of the present invention and the comparative laminated material, 2 orange juice was added inside.
A 170 x 130 m sealed packaging bag containing 00 rubber was prepared so that the packaging base surface of each laminate became the outer surface. The sealed packaging bag is obtained by heat-sealing the inner peripheral layers of the bag and by heat-sealing the four peripheral edges of the laminate.

Each sealed packaging bag containing the orange juice is 1.2 ff! The impact resistance of the sealed packaging bag was investigated based on the degree of damage caused to the sealed bag when it was dropped from a height of After opening the package and conducting a sensory test of the flavor of the orange juice inside, it was possible to determine the presence of volatile components retained in the orange juice, which is the inner filling.
The fragrance retention performance of each of the sealed packaging bags was compared.

The results are shown in Table 1.

Table 1 [Operations and effects of the invention] The laminated material of the present invention having excellent fragrance retention properties is
a saturated polyester resin layer made of a linear saturated polyester resin having a glass transition temperature of ℃ or higher;
A laminated resin layer formed by pasting a polyolefin resin layer made of ethylene-α/olefin copolymer with an adhesive layer made of adhesive polyolefin resin can be applied to various packaging material base materials. , The saturated polyester resin layer in the laminated resin layer is laminated and adhered as the outermost layer, and when molded into various containers, packaging bags, etc., the laminated material is used as a packaging material. It is used so that the base material side becomes the outer peripheral surface layer, that is, the laminated resin layer side of the laminated material becomes the inner peripheral surface layer.

However, in the laminate material of the present invention having the above structure,
The saturated polyester resin layer in the laminated material exhibits extremely good fragrance retention performance at a temperature below the glass transition temperature of the resin constituting the saturated polyester resin layer, and the saturated polyester resin layer and ethylene −α
- A polyolefin resin layer made of an olefin copolymer is a layer that is firmly and integrally bonded with an adhesive layer made of an adhesive polyolefin resin interposed between the two, and is used for packaging bags made of the above-mentioned laminated material. Various types of containers can have extremely excellent impact resistance.

The above-mentioned excellent impact resistance provided in the packaging bag or container obtained using the laminated material of the present invention includes heat seal strength,
The impact force applied to the saturated polyester resin layer, which has low impact strength, is smoothly absorbed by the adhesive layer made of adhesive polyolefin resin, which has a high tensile modulus. This is because the impact is transmitted to the resin layer, and the layer has a high degree of shock absorbing power due to its high tensile modulus, which provides a relaxing effect. The polyolefin resin layer made of ethylene-α/olefin copolymer used in the laminated material of the present invention has extremely high impact resistance among olefin resins, and this property However, the laminate of the present invention provides packaging bags and containers with excellent heat seal strength and impact strength.

[Brief explanation of drawings]

The figure shows one of the laminated materials of the present invention having excellent fragrance retention properties.
FIG. 2 is a cross-sectional view of a model showing an example product. 1: Laminated material, 4: Base material for packaging material, 5: Saturated polyester resin layer made of linear saturated polyester resin having a glass transition temperature of 40°C or higher, 6: Polyolefin made of ethylene-α/olefin copolymer 7: Adhesive layer made of adhesive polyolefin resin; 8: Laminated resin layer.

Claims (2)

[Claims] (1) a saturated polyester resin layer made of a linear saturated polyester resin having a glass transition temperature of 40°C or higher;
Ethylene bonded to the saturated polyester resin layer by an adhesive layer made of an adhesive polyolefin resin.
A laminated resin layer comprising a polyolefin resin layer made of an α-olefin copolymer is laminated on a base material for packaging material such that the saturated polyester resin layer is the outermost layer. A laminated material with excellent fragrance retention properties. (2) The adhesive layer made of adhesive polyolefin resin is
The fragrance retention performance according to claim 1, which is an adhesive layer made of a polyolefin resin obtained by introducing an ethylenically unsaturated monomer containing a carbonyl group into the main chain or side chain of a polyolefin resin. A laminated material with excellent properties.