JP2023139995A - Laminated film and packaging bag - Google Patents

Abstract

To provide an aluminum-free laminated film having excellent gas barrier properties and tear strength.SOLUTION: A laminated film according to one embodiment of the present invention includes a substrate layer, and a sealant layer, which serves as one of its outermost surfaces. The substrate layer contains a liquid crystal polymer and a modified polyethylene terephthalate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a laminated film and a packaging bag.

BACKGROUND ART Conventionally, packaging bags made of a laminated film, in which a sealant layer is laminated on the inner surface of a base layer made of film, paper, etc., have been widely used as packaging bags for containing contents such as foods and medicines. The laminated film used in such packaging bags generally contains gases that alter the contents, such as water vapor and oxygen, in order to suppress deterioration and decay of the contents and maintain their functions and properties. A laminated film is used that has gas barrier properties that block the entry of gas.

For example, Patent Document 1 discloses that a laminated film in which a base material layer/first adhesive layer/gas barrier layer/second adhesive layer/sealant layer are sequentially laminated is sealed with the sealant layer as the inner surface to form a sealed portion. A packaging bag is disclosed. Further, it is described that the gas barrier layer is a polyester film deposited with aluminum or an inorganic oxide, so that it has excellent gas barrier properties and can maintain the quality of the fragrance for a long time.

JP 2014-5013 Publication

However, in conventional laminated films, the gas barrier layer is often a polyester film or aluminum foil deposited with aluminum, and such laminated films containing aluminum generate a large amount of _CO2 during the manufacturing and disposal process. Another problem is that it is difficult to separate and collect them when disposing of them. To solve this problem, it is possible to use a liquid crystal polymer having excellent gas barrier properties as a gas barrier layer, but liquid crystal polymers have the disadvantage of lacking tear strength when processed into a film.

In view of the above points, an object of one embodiment of the present invention is to provide an aluminum-free laminated film having excellent gas barrier properties and tear strength.

A laminated film according to one embodiment of the present invention has a base layer and a sealant layer serving as one outermost surface, and the base layer includes a liquid crystal polymer and modified polyethylene terephthalate.

According to one aspect of the present invention, an aluminum-free laminated film having excellent gas barrier properties and tear strength can be provided.

FIG. 1 is a schematic diagram showing a cross section of a laminated film according to one embodiment. FIG. 2 is a schematic diagram of a packaging bag according to one embodiment.

Embodiments of the present invention will be described below with reference to the drawings. In this specification, "~" indicating a numerical range means that the lower limit and upper limit include the numerical values written before and after it, unless otherwise specified. FIG. 1 is a schematic diagram showing a cross section of a laminated film 1 according to one embodiment. The laminated film 1 of this embodiment has a base material layer 2 and a sealant layer 3. The sealant layer 3 becomes one outermost surface of the laminated film 1. Here, the sealant layer 3 is a layer used for heat sealing, and when the laminated film 1 is used as a packaging material, it is a layer disposed as the innermost layer in contact with the contents. Although the base material layer 2 and the sealant layer 3 may be bonded via an adhesive layer or an anchor layer, it is preferable that they are bonded directly.

The base material layer 2 includes a liquid crystal polymer (A) and a modified polyethylene terephthalate (B), and may be composed of the liquid crystal polymer (A) and a modified polyethylene terephthalate (B).

The liquid crystal polymer (A) used for the base material layer 2 of this embodiment is preferably one that does not contain inorganic substances such as glass and fillers. Examples of the liquid crystal polymer (A) include VECTORA (registered trademark) and ZENITE (registered trademark) manufactured by Celanese, and UENO LCP (registered trademark) manufactured by Ueno Pharmaceutical Co., Ltd.

When the laminated film 1 is used as a packaging material, the base material layer 2 located outside the sealant layer 3 in contact with the contents contains liquid crystal polymer (A) and modified polyethylene terephthalate (B), so that The laminated film 1 of this embodiment can exhibit excellent gas barrier properties. In this specification, gas barrier properties are properties that block gas, and include water vapor barrier properties that block water vapor, and oxygen barrier properties that block oxygen. Furthermore, since the base layer 2 contains the liquid crystal polymer (A) and the modified polyethylene terephthalate (B), the base layer 2 and the laminated film 1 having the base layer 2 have excellent tear strength. . Since the base layer 2 has excellent tear strength, the laminated film 1 has good processability.

Since the laminated film 1 of this embodiment is aluminum-free (does not contain aluminum), it is possible to reduce the amount of CO ₂ generated during manufacturing and disposal processes. Furthermore, when discarding the laminated film 1, it can be disposed of as plastic waste, so it can be easily separated and collected. In addition, the liquid crystal polymer (A) and modified polyethylene terephthalate (B) that constitute the base material layer 2 have good affinity and can be mixed uniformly, so there is no need to add, for example, a reactive compatibilizer. Can also be mixed. Therefore, the laminated film 1 of this embodiment has excellent recyclability. Furthermore, since the laminated film 1 of this embodiment is aluminum-free, it can be used in a production line that uses a metal detector to detect metal foreign objects.

The content of the liquid crystal polymer (A) in the base layer 2 is preferably 78 parts by mass to 99 parts by mass, more preferably 80 parts by mass to 90 parts by mass. By setting the content of the liquid crystal polymer (A) to 78 parts by mass to 99 parts by mass, the laminated film 1 of the present embodiment can exhibit better gas barrier properties and tear strength.

The modified polyethylene terephthalate (B) used in the base layer 2 of this embodiment is a linear polyester resin obtained by condensation polymerization of a dicarboxylic acid component and a diol component, in which the dicarboxylic acid component is mainly composed of terephthalic acid. , a copolymer that further contains a dicarboxylic acid other than terephthalic acid, and the diol component is ethylene glycol as the main component, or the dicarboxylic acid component is terephthalic acid as the main component, and the diol component is ethylene glycol as the main component. It is a copolymer that further contains a diol other than ethylene glycol. In this specification, the main component means the component with the highest content. Note that the modified polyethylene terephthalate (B) is non-liquid crystal and is not included in the liquid crystal polymer (A).

In addition to terephthalic acid, dicarboxylic acid components include aromatic dicarboxylic acids such as isophthalic acid, naphthalene-1,4-dicarboxylic acid, and naphthalene-2,6-dicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid and sebacic acid. can be mentioned.

In addition to ethylene glycol, diol components include linear diols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexamethylene diol; cyclopentanedimethanol; Cyclic diols such as cyclohexanedimethanol; neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2,2-dipropyl-1,3-propanediol, 2-propyl-2-methyl-1,3- Propanediol, 2-propyl-2-ethyl-1,3-propanediol, 2-isopropyl-2-methyl-1,3-propanediol, 2-isopropyl-2-ethyl-1,3-propanediol, 2- Branched diols such as butyl-2-methyl-1,3-propanediol and 2-butyl-2-ethyl-1,3-propanediol are mentioned. Branched diols have one or more alkyl groups as side chains branching from the main chain, whereas linear diols have only a main chain containing two hydroxyl groups.

Modified polyethylene terephthalate (B) is composed of isophthalic acid-modified polyethylene terephthalate modified with isophthalic acid and polyethylene terephthalate modified with a diol having two alkyl groups (hereinafter also referred to as "dialkyl-substituted diol-modified polyethylene terephthalate"). It is preferable that at least one kind is included. With this configuration, the laminated film 1 of this embodiment can exhibit excellent gas barrier properties and tear strength.

Isophthalic acid-modified polyethylene terephthalate is a linear polyester resin obtained by condensation polymerization of a dicarboxylic acid component and a diol component, in which the dicarboxylic acid component mainly contains terephthalic acid and further contains isophthalic acid, and the diol component is It is a copolymer whose main component is ethylene glycol.

When the modified polyethylene terephthalate (B) contains isophthalic acid-modified polyethylene terephthalate, the copolymerization ratio of the isophthalic acid component in the dicarboxylic acid component constituting the isophthalic acid-modified polyethylene terephthalate is preferably 3 mol% to 30 mol%, and 5 mol%. % to 25 mol%. Here, the copolymerization ratio of the isophthalic acid component in the dicarboxylic acid component is the proportion (mol percentage) occupied by the isophthalic acid component in the dicarboxylic acid component. Since the copolymerization ratio of the isophthalic acid component in the dicarboxylic acid component is 3 mol % or more, the laminated film 1 of this embodiment can exhibit better gas barrier properties and tear strength, and the base layer 2 It is possible to prevent neck-in from occurring during the film forming process and obtain good processability. In addition, since the copolymerization ratio of the isophthalic acid component in the dicarboxylic acid component is 30 mol% or less, heat resistance that can withstand the heat when heat sealing the laminated films 1 to each other or the laminated film 1 and other films is achieved; It is possible to provide a laminated film 1 having heat resistance that can withstand the heat of the contents when a packaging bag or the like formed of the laminated film 1 is filled with high-temperature contents.

The intrinsic viscosity (IV) of the isophthalic acid-modified polyethylene terephthalate is preferably 0.60 dl/g to 0.85 dl/g. Here, the intrinsic viscosity is a value measured at 30° C. in a mixed solvent of phenol/1,1,2,2-tetrachloroethane (mass ratio 1/1) according to JIS K 7367-5. By having an intrinsic viscosity of 0.60 dl/g or more, the laminated film 1 of this embodiment can exhibit better gas barrier properties. Moreover, since the intrinsic viscosity is 0.85 dl/g or less, extrusion processing of the base material layer 2 becomes easy, and the processability of the laminated film 1 can be improved.

When the modified polyethylene terephthalate (B) is isophthalic acid-modified polyethylene terephthalate, the content of the liquid crystal polymer (A) in the base layer 2 is 78 parts by mass to 99 parts by mass, The content of polyethylene terephthalate is preferably 1 part by mass to 22 parts by mass. When the content of the liquid crystal polymer (A) and isophthalic acid-modified polyethylene terephthalate is within the above range, the laminated film 1 of this embodiment can exhibit better gas barrier properties and tear strength.

Dialkyl-substituted diol-modified polyethylene terephthalate is a linear polyester resin obtained by condensation polymerization of a dicarboxylic acid component and a diol component, in which the dicarboxylic acid component is mainly composed of terephthalic acid and the diol component is mainly composed of ethylene glycol. , is a copolymer further containing a diol having two alkyl groups.

A diol having two alkyl groups has two alkyl groups in the side chain of a branched diol. By modifying polyethylene terephthalate by using a diol having two alkyl groups as part of the diol component, the crystallinity of polyethylene terephthalate can be reduced to make it amorphous or low-crystalline. Thereby, the tear strength of the laminated film 1 can be improved.

A diol having two alkyl groups is a straight chain diol with n carbon atoms whose general formula is HO(CH ₂ ) _n OH, in which two hydrogen atoms out of a total of 2n hydrogen atoms are an alkyl group. has been replaced with The number of carbon atoms n in the main chain is, for example, within the range of 1 to 6. The positions a and b of the carbon atom substituted with an alkyl group can each be independently selected from a range of 1 to n.

When the dialkyl substitution position a or b of the diol is equal to 1 or n, the hydroxyl group becomes a secondary alcohol or a tertiary alcohol, so that the condensation reaction with the carboxylic acid component occurs during the synthesis of dialkyl-substituted diol-modified polyethylene terephthalate. It may be difficult to progress. Therefore, it is preferable that the alkyl group substitution positions a and b are larger than 1 and smaller than n.

When positions a and b of dialkyl substitution are equal, the general formula of a diol having two alkyl groups is represented by HO(CH ₂ ) _a-1 C(R1)(R2)(CH ₂ ) _n-a OH . R1 and R2 are each an alkyl group having, for example, 1 to 6 carbon atoms. Examples of the alkyl group include methyl group with 1 carbon number, ethyl group with 2 carbon atoms, propyl group or isopropyl group with 3 carbon atoms, butyl group and isobutyl group with 4 carbon atoms, pentyl group and isopentyl group with 5 carbon atoms, etc. can be mentioned.

The number n of carbon atoms in the main chain of the diol having two alkyl groups is more preferably 3 to 4, and the number of carbon atoms in the alkyl groups R1 and R2 is more preferably 1 to 4. For example, in the case of neopentyl glycol or 2-butyl-2-ethyl-1,3-propanediol, n=3 and a=b=2. In neopentyl glycol, 2,2-dimethyl-1,3-propanediol, R1 and R2 are methyl groups. In 2-butyl-2-ethyl-1,3-propanediol, R1 and R2 are butyl and ethyl groups, respectively.

When the modified polyethylene terephthalate (B) contains dialkyl-substituted diol-modified polyethylene terephthalate, the copolymerization ratio of the diol having two alkyl groups in the diol component constituting the dialkyl-substituted diol-modified polyethylene terephthalate is 10 mol% to 40 mol%. It is preferably 15 mol% to 30 mol%. Here, the copolymerization ratio of the diol component having two alkyl groups in the diol component is the mol percentage occupied by the diol component having two alkyl groups in the diol component. Since the copolymerization ratio of the diol component having two alkyl groups is 10 mol% or more, the laminated film 1 of the present embodiment can exhibit better gas barrier properties and tear strength, and the base material layer During the film forming process in step 2, neck-in can be prevented from occurring and good processability can be obtained. In addition, since the copolymerization ratio of the diol component having two alkyl groups is 40 mol% or less, heat when heat-sealing the laminated films 1 to each other or the laminated film 1 and another film, or the laminated film 1 It is possible to provide a laminated film 1 having heat resistance that can withstand the heat generated when the formed container is filled with high-temperature contents.

The dialkyl-substituted diol-modified polyethylene terephthalate is preferably neopentyl glycol-modified polyethylene terephthalate modified with neopentyl glycol. Neopentyl glycol-modified polyethylene terephthalate is a copolymer in which the dicarboxylic acid component is mainly terephthalic acid, the diol component is mainly ethylene glycol, and further contains neopentyl glycol. Specifically, for example, Velpet (registered trademark) may be mentioned. Since the dialkyl-substituted diol-modified polyethylene terephthalate is neopentyl glycol-modified polyethylene terephthalate, the laminated film 1 of this embodiment can exhibit better gas barrier properties and tear strength.

The intrinsic viscosity (IV) of neopentyl glycol-modified polyethylene terephthalate is preferably 0.70 dl/g to 0.90 dl/g. Here, the intrinsic viscosity is a value measured at 30° C. in a mixed solvent of phenol/1,1,2,2-tetrachloroethane (mass ratio 1/1) according to JIS K 7367-5. By having an intrinsic viscosity of 0.70 dl/g or more, the laminated film 1 of this embodiment can exhibit better gas barrier properties. Moreover, since the intrinsic viscosity is 0.90 dl/g or less, extrusion processing of the base material layer 2 becomes easy, and the processability of the laminated film 1 can be improved.

When the modified polyethylene terephthalate (B) is neopentyl glycol modified polyethylene terephthalate, the content of the liquid crystal polymer (A) with respect to the base material layer 2 is 83 parts by mass to 99 parts by mass, The content of glycol-modified polyethylene terephthalate is preferably 1 part by mass to 17 parts by mass. When the content of the liquid crystal polymer (A) and neopentyl glycol-modified polyethylene terephthalate is within the above range, the laminated film 1 of this embodiment can exhibit better gas barrier properties and tear strength.

As the sealant layer 3 of the laminated film 1, a resin film having excellent heat resistance, mechanical properties, and printability is preferable. Specifically, the sealant layer 3 preferably contains one or more of polyethylene resin, polypropylene resin, polyester resin, and cyclic olefin resin. Thereby, the two laminated films 1 can be opposed to each other, and the sealant layers 3 can be bonded together by heat.

The polyester resin is preferably isophthalic acid-modified polyethylene terephthalate modified with isophthalic acid. The isophthalic acid-modified polyethylene terephthalate contained in the sealant layer 3 can be the same as the isophthalic acid-modified polyethylene terephthalate contained in the base layer 2 described above. Since the polyester resin is isophthalic acid-modified polyethylene terephthalate, the laminated film 1 of this embodiment can exhibit even more excellent gas barrier properties. Furthermore, since the sealant layer 3 contains isophthalic acid-modified polyethylene terephthalate, the adhesiveness between the sealant layer 3 and the base layer 2 containing modified polyethylene terephthalate (B) can be improved.

The sealant layer 3 may contain additives as components other than resin. Examples of additives include, but are not limited to, antioxidants, lubricants, antiblocking agents, stabilizers, ultraviolet absorbers, flame retardants, antistatic agents, colorants, and the like.

The laminated film 1 may have another layer provided on the side opposite to the sealant layer 3 with respect to the base layer 2, and the other layer preferably contains a resin other than the liquid crystal polymer. Other layers may include, for example, intermediate layers, adhesive layers, anchoring agent layers, and the like. As the intermediate layer, one layer or a plurality of layers such as a reinforcing layer, a gas barrier layer, a light shielding layer, a printed layer, etc. can be selected as appropriate.

It is preferable that the base material layer 2, the sealant layer 3, and other layers are formed into a film shape. The method for molding the films constituting the base layer 2, sealant layer 3, and other layers is not particularly limited, but extrusion molding is preferred. Examples of extrusion molding include T-die molding, inflation molding, etc., and T-die molding is particularly preferred. More preferably, the film is heat-treated with a cooling roll after T-die molding. Alternatively, adjacent layers may be simultaneously melt-extruded and film-formed using a coextrusion method. When continuously molding a long film, it is preferable to wind up the long molded film after molding, since productivity is excellent. Moreover, the strength and heat deformation resistance of the film can be improved by uniaxially or biaxially stretching the formed film before lamination.

The method for producing the laminated film 1 is not particularly limited, and the layers constituting the laminated film 1 can be appropriately laminated by extrusion lamination, dry lamination, coextrusion, or a combination thereof. The thickness of the base layer 2 of the laminated film 1 depends on the use of the packaging material and is not particularly limited, but is usually about 10 μm to 200 μm, preferably 15 μm to 120 μm. The thickness of the sealant layer 3 may be, for example, 10 μm to 50 μm.

FIG. 2 is a schematic diagram of a packaging bag 10 according to one embodiment. The packaging bag 10 is formed using the laminated film 1 of this embodiment. As shown in FIG. 2, the packaging bag 10 has a bag-shaped body 11 formed from the laminated film 1 and an opening 12 joined to at least one location on the periphery of the body 11. The shape of the trunk 11 is not particularly limited, but examples include a three-sided bag, a four-sided bag, a gassho bag, a gusset bag, and a standing pouch. The body 11 may be a large packaging bag, such as an inner bag for a bag-in-box.

The material constituting the mouth portion 12 can be suitably used as long as it can be bonded to the sealant layer 3 of the laminated film 1 constituting the packaging bag 10 to ensure sealing, but materials that can be heat-sealed with the sealant layer 3 of the laminated film 1 are suitable. Preferably, it is a resin. Thereby, the mouth part 12 and the laminated film 1 can be joined by heat sealing. For this reason, the material constituting the mouth portion 12 is preferably polyethylene terephthalate resin, and more preferably isophthalic acid-modified polyethylene terephthalate resin. Thereby, the opening portion 12 can be easily heat-sealed with the sealant layer 3 of the laminated film 1, and the gas barrier properties of the packaging bag 10 can be improved.

When heat-sealing the laminated film 1 and the mouth part 12, the laminated films 1 may be overlapped with the sealant layer 3 on the inside, and the mouth part 12 may be inserted between the overlapped sealant layers 3 and heat-sealed. Alternatively, a flange or a boat-shaped fusion base may be provided at one end of the opening 12, and this flange or fusion base may be heat-sealed to the periphery of the hole provided in the laminated film 1 or the inner surface of the opening of the packaging bag. good.

The present invention will be specifically explained below with reference to Examples. Note that the present invention is not limited to these examples.

Each raw material was blended in the proportions shown in Table 1, melt-kneaded, and then extruded using a T-die extruder to obtain a film with a thickness of 100 μm. Details of each raw material shown in Table 1 are as follows.

(A) Liquid crystal polymer A-1: Low melting point liquid crystal polymer (trade name "UENO LCP (registered trademark) A-8100", manufactured by Ueno Pharmaceutical Co., Ltd., density ρ = 1.40 g/cm ³ , melting point Tm = 220 ° C.)

(B) Modified polyethylene terephthalate (modified PET)
B-1: Isophthalic acid-modified polyethylene terephthalate (copolymerization ratio of isophthalic acid component in dicarboxylic acid component: 12 mol%, density ρ = 1.34 g/cm ³ , melting point Tm = 224°C, intrinsic viscosity IV = 0.80 dl/g)
B-2: Isophthalic acid modified polyethylene terephthalate (copolymerization ratio of isophthalic acid component in dicarboxylic acid component: 23 mol%, density ρ = 1.34 g/cm ³ , intrinsic viscosity IV = 0.68 dl/g)
B-3: Neopentyl glycol modified polyethylene terephthalate (trade name "Belpet (registered trademark) E-03", manufactured by Bell Polyester Products Co., Ltd., density ρ = 1.29 g/cm ³ , intrinsic viscosity IV = 0.83 dl/g )

(C) Polyethylene terephthalate (PET)
Unmodified polyethylene terephthalate (density ρ = 1.34 g/cm ³ , melting point Tm = 260°C, intrinsic viscosity IV = 0.75 dl/g)

(D) Polyethylene (PE)
High density polyethylene (density ρ = 0.949g/cm ³ , melting point Tm = 130°C, melt flow rate MFR = 1.1g/10min (190°C, 2.16kgf))

Note that the melt flow rate (MFR) is a value (g/10 min) at a test temperature of 190° C. and a nominal load of 2.16 kg. The intrinsic viscosity is a value (dl/g) measured at 30° C. in a mixed solvent of phenol/1,1,2,2-tetrachloroethane at a mass ratio of 1/1.

Next, each of the obtained films was evaluated as follows.

(Oxygen gas permeability, water vapor permeability)
The oxygen gas permeability and water vapor permeability of the produced film were measured in accordance with JIS K 7126-1 and JIS K 7129.

(Tensile modulus)
The tensile modulus of the film in the machine direction and width direction was measured at a sample width of 15 mm, a distance between the grips of 50 mm, and a tensile speed of 300 mm/min.

(tear strength)
A slit with a length of 75 mm was made in the center of a sample cut to a length of 150 mm and a width of 50 mm, and the tear strength in the machine direction was measured using the trouser method with a grip distance of 50 mm and a tensile speed of 200 mm/min.

(Workability)
The film-forming property when the film raw material was extruded using a T-die extruder and the winding operability of the obtained film were confirmed. Comprehensive evaluation of film formability and winding operability was performed based on evaluation criteria of A: good, B: slightly poor, and C: poor.

The above evaluation results are shown in Table 2.

As shown in Table 2, in the films of Examples 1 to 7, the oxygen permeability was less than 0.4 cc/m ² ·day · atm, and the water vapor permeability was less than 0.1 (g/m ² ·day). It was confirmed that the film had almost the same excellent gas barrier properties as the film of Comparative Example 1 made of a single liquid crystal polymer. Furthermore, it was confirmed that the films of Examples 1 to 7 had excellent tear strength, as well as excellent tensile modulus in the machine direction and tensile modulus in the width direction. Furthermore, the films of Examples 1 to 7 were also good in processability (film formability and winding operability).

Although the film of Comparative Example 1 was excellent in gas barrier properties (oxygen permeability and water vapor permeability), it was inferior in tear strength. In addition, the film of Comparative Example 1 was intermittently torn in the machine direction during the winding operation of the film, making it impossible to stably process the film, resulting in poor processability. Although the film of Comparative Example 2 had good tensile modulus in the width direction, tear strength, and processability, it had poor gas barrier properties and tensile modulus in the machine direction compared to the films of Examples 1 to 7. Ta. In the film of Comparative Example 3, the water vapor permeability exceeded 0.1 (g/m ² ·day). The film of Comparative Example 4 had significantly inferior gas barrier properties compared to the films of Examples 1 to 7, and the neck-in was large when the raw material for the film was extruded using a T-die extruder, making it difficult to collect samples from the film. The width was narrow, and the film forming properties were poor. The film of Comparative Example 5 had significantly poorer gas barrier properties than the films of Examples 1 to 7, and in particular had virtually no oxygen barrier properties.

Furthermore, after producing a coextruded two-layer film using each of the films of Examples 1 to 7 as the base material layer and modified PET (B-2) as the sealant layer, a heat sealing temperature of 170°C and a sealing pressure of 0. A three-pack sealed bag was produced under a pressure of 2 MPa and a sealing time of 1 sec, and it was confirmed that the packaging bag could be produced without any problems.

1 Laminated film 2 Base material layer 3 Sealant layer 10 Packaging bag 11 Body part 12 Mouth part

Claims (11)

It has a base material layer and a sealant layer that is the outermost surface of one,
The base layer is a laminated film containing a liquid crystal polymer and modified polyethylene terephthalate. The laminated film according to claim 1, wherein the modified polyethylene terephthalate contains at least one of isophthalic acid-modified polyethylene terephthalate modified with isophthalic acid and polyethylene terephthalate modified with a diol having two alkyl groups. The laminated film according to claim 2, wherein the polyethylene terephthalate modified with a diol having two alkyl groups is neopentyl glycol-modified polyethylene terephthalate modified with neopentyl glycol. The modified polyethylene terephthalate is the isophthalic acid modified polyethylene terephthalate,
The laminated film according to claim 2 or 3, wherein the copolymerization ratio of the isophthalic acid component in the dicarboxylic acid component constituting the isophthalic acid-modified polyethylene terephthalate is 3 mol% to 30 mol%. The content of the liquid crystal polymer in the base material layer is 78 parts by mass to 99 parts by mass, and the content of the isophthalic acid-modified polyethylene terephthalate in the base material layer is 1 part by mass to 22 parts by mass. 4. The laminated film according to 4. The modified polyethylene terephthalate is the neopentyl glycol modified polyethylene terephthalate,
The content of the liquid crystal polymer in the base material layer is 83 parts by mass to 99 parts by mass, and the content of the neopentyl glycol modified polyethylene terephthalate in the base material layer is 1 part by mass to 17 parts by mass. Item 3. Laminated film according to item 3. The laminated film according to any one of claims 1 to 6, wherein the sealant layer contains one or more of polyethylene resin, polypropylene resin, polyester resin, and cyclic olefin resin. The laminated film according to claim 7, wherein the polyester resin is isophthalic acid-modified polyethylene terephthalate modified with isophthalic acid. having another layer provided on the side opposite to the sealant layer with respect to the base material layer,
The laminated film according to any one of claims 1 to 8, wherein the other layer contains a resin other than the liquid crystal polymer. The laminated film according to any one of claims 1 to 9, wherein the base layer is formed into a film shape by extrusion molding. A packaging bag formed using the laminated film according to any one of claims 1 to 10.

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