Polyester film, laminate, package, and product

Abstract

This polyester film has a first layer and a second layer. The first layer contains a first polyester resin that includes first acid units and first alcohol units. The first acid units include 60-80 mol% of a terephthalic acid unit and 20-40 mol% of an isophthalic acid unit with respect to the total amount of the first acid units. The first alcohol units include 75 mol% or more of an ethylene glycol unit with respect to the total amount of the first alcohol units. The second layer contains a second polyester resin that includes second acid units including a terephthalic acid unit and second alcohol units including an ethylene glycol unit and a diethylene glycol unit. The total amount of the terephthalic acid unit in the second polyester resin and the ethylene glycol unit and the diethylene glycol unit in the second polyester resin is 95% or more with respect to the total amount of the second acid units and the second alcohol units.

Description

Polyester films, laminates, packaging, and products Related Applications

[0001] This application claims priority from Japanese Patent Application No. 2024-28153, filed February 28, 2024, and incorporates by reference all of the contents of that Japanese application.

[0002] The present invention relates to a polyester film, and to a laminate, a package, and a product using the polyester film.

[0003] Sealant films have traditionally been used as packaging materials for packaging foods and beverages, cosmetics, pharmaceuticals, quasi-drugs, and the like. For example, polyolefin resins such as polyethylene and polypropylene are sometimes used as such sealant films. While polyolefin resins exhibit high sealing strength in thermocompression bonding, they have a problem in that they tend to adsorb organic compounds (e.g., fragrances such as limonene, and medicinal ingredients such as camphor, menthol, and methyl salicylate) contained in the packaged items (contents), which can impair the quality of the packaged items.

[0004] In order to solve the above problems, for example, a sealant film has been proposed, which is a laminate film consisting of at least two layers, having a polyester layer X and a polyester layer Z, in which the polyester layer X contains a copolymer polyester formed from a copolymer of a dicarboxylic acid component and a diol component, the dicarboxylic acid component containing terephthalic acid and the diol component containing 1,4-cyclohexanedimethanol, and the polyester layer Z contains homopolyethylene terephthalate as a main component resin (see, for example, Patent Document 1).

[0005] Furthermore, a sealant film made of a polyester resin copolymerized with 3.0 mol % to 15 mol % of isophthalic acid has been proposed (see, for example, Patent Document 2).

[0006] JP 2023-128207 A JP 2023-49391 A

[0007] However, the sealant film having a heat seal layer containing 1,4-cyclohexanedimethanol as a copolymerization component described in Patent Document 1 exhibits good low adsorption properties for fat-soluble organic compounds such as camphor and menthol, but has the problem that its low adsorption properties for fat-insoluble organic compounds such as methyl salicylate are significantly inferior to those of sealant films made of polyolefin resins such as polyethylene.

[0008] Furthermore, copolymer polyester resins have a high glass transition temperature of 70°C or higher, and therefore have lower seal strength when thermocompressed at low temperatures (e.g., 110°C) than polyolefin resins such as polyethylene, which means that bags formed by thermocompression bonding of the sealant film cannot maintain their original shape. Therefore, thermocompression bonding at high temperatures (e.g., 150°C) requires a large amount of heat energy, which increases production costs and also leads to problems such as the tendency for the thermocompression bonding member of the thermocompression bonding device to deteriorate.

[0009] The sealant film made of a polyester resin containing isophthalic acid as a copolymerization component, as described in Patent Document 2, has excellent low adsorption properties not only for fat-soluble organic compounds such as camphor and menthol but also for fat-insoluble organic compounds such as methyl salicylate, but has the problem that the seal strength when thermocompressed at a low temperature (e.g., 110°C) is low, so that bags formed by thermocompression bonding of the sealant film cannot maintain their original shape. Therefore, thermocompression bonding at a high temperature (e.g., 150°C) requires a large amount of thermal energy, which increases production costs and causes problems such as the tendency for the thermocompression members of the thermocompression bonding device to deteriorate.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polyester film that has excellent low adsorption properties for organic compounds and can achieve high sealing strength even when thermocompressed at low temperatures, as well as a laminate, a package, and a product that use the polyester film.

[0011] The polyester film of the present invention has a first layer and a second layer. The first layer comprises a first polyester resin containing first acid units and first alcohol units. The first acid units comprise 60 mol % to 80 mol % of terephthalic acid units and 20 mol % to 40 mol % of isophthalic acid units, relative to the total amount of the first acid units. The first alcohol units comprise 75 mol % or more of ethylene glycol units, relative to the total amount of the first alcohol units. The second layer comprises a second polyester resin containing second acid units containing terephthalic acid units and second alcohol units containing ethylene glycol units and diethylene glycol units. The total amount of the terephthalic acid units in the second polyester resin and the ethylene glycol units and diethylene glycol units in the second polyester resin is 95% or more, relative to the total amount of the second acid units and the second alcohol units.

[0012] In one embodiment of the polyester film of the present invention, the first alcohol units preferably contain 95 mol % to 99 mol % ethylene glycol units and 1 mol % to 5 mol % diethylene glycol units, relative to the total amount of the first alcohol units. In another embodiment of the polyester film of the present invention, the first alcohol units preferably contain 75 mol % to 90 mol % ethylene glycol units, 1 mol % to 5 mol % diethylene glycol units, and 5 mol % to 20 mol % 2,2-dimethyl-1,3-propanediol units, relative to the total amount of the first alcohol units. In one embodiment of the polyester film of the present invention, the second acid units preferably contain 90 mol % or more of terephthalic acid units and 0.5 mol % to 10 mol % of isophthalic acid units, based on the total amount of the second acid units; and the second alcohol units preferably contain 95 mol % to 99 mol % of ethylene glycol units and 1 mol % to 5 mol % of diethylene glycol units, based on the total amount of the second alcohol units.

[0013] In one embodiment of the polyester film of the present invention, the polyester film preferably has a thickness of 20 μm to 100 μm. In one embodiment of the polyester film of the present invention, the first layer preferably has a thickness of 2 μm to 15 μm.

[0014] In one embodiment of the polyester film of the present invention, the first polyester resin has a viscosity of 10.70 cal / cm ３ ~15 cal / cm ３ The second polyester resin has a solubility parameter (SP value) of 10.70 cal / cm ３ ~15 cal / cm ３ It is preferable that the SP value is 0.01 or less.

[0015] In one embodiment of the polyester film of the present invention, the polyester film preferably has a crystallinity of 5% to 15%. In one embodiment of the polyester film of the present invention, when two polyester films 1 and 2 are thermocompression-bonded under conditions of 110°C to 150°C, 0.2 MPa, and 2 seconds, the seal strength between polyester film 1 and polyester film 2 is preferably 15 N / 15 mm to 50 N / 15 mm.

[0016] In one embodiment of the polyester film of the present invention, the first layer preferably contains a first polyester resin in an amount of 70% by mass or more relative to the mass of the first layer, and a second polyester resin in an amount of 5% by mass to 30% by mass relative to the mass of the first layer. ３ ~15 cal / cm ３ It is preferable that the SP value is 0.01 or less.

[0017] In one embodiment of the polyester film of the present invention, the second layer preferably contains 90% by mass or more of the second polyester resin relative to the mass of the second layer, and 5% by mass to 10% by mass of the first polyester resin relative to the mass of the second layer. ３ ~15 cal / cm ３It is preferable that the SP value is 0.01 or less.

[0018] In one embodiment of the polyester film of the present invention, it is preferable that a third layer is provided between the first layer and the second layer, and the third layer contains a second polyester resin.

[0019] In one embodiment of the polyester film of the present invention, the polyester film is preferably an unstretched film.

[0020] The laminate of the present invention has a base film and a sealant layer, and the sealant layer contains the polyester film of the present invention.

[0021] The packaging material of the present invention has the polyester film of the present invention, and at least parts of the polyester film are fused together.

[0022] The product of the present invention includes a packaged item containing an organic compound and the polyester film of the present invention that packages the packaged item, and at least a portion of the polyester film is fused to itself.

[0023] In one embodiment of the product of the present invention, the SP value of the polyester film is preferably greater than the SP value of the organic compound contained in the packaged article, and the organic compound is preferably at least one selected from the group consisting of camphor, menthol, methyl salicylate, limonene, tocopherol acetate, isopropylmethylphenol, ketoprofen, ketoprofen sodium, diclofenac sodium, felbinac, loxoprofen sodium, tulobuterol, rivastigmine, clopumazine hydrochloride, haloperidol, risperidone, paliperidone, blonanserin, perospirone hydrochloride hydrate, lurasidone hydrochloride, olanzapine, quetiapine fumarate, asenapine maleate, clozapine, aripiprazole, and brexpiprazole.

[0024] According to the present invention, it is possible to provide a polyester film that has excellent low adsorption properties for organic compounds and can achieve high seal strength even when thermocompressed at low temperatures, as well as laminates, packages, and products that use the polyester film.

[0025] Fig. 1 is a schematic view showing one embodiment of the polyester film of the present invention, and Fig. 2 is a schematic view showing another embodiment of the polyester film of the present invention.

[0026] (Polyester Film) The polyester film of the present invention has a first layer, a second layer, and preferably a third layer, and may further have other layers as required.

[0027] The polyester film of the present invention is suitable as a sealant film for packaging because it can achieve high sealing strength even when thermocompressed at a low temperature (e.g., 110°C). The polyester film of the present invention has low adsorption of organic compounds, so that in a package using the polyester film of the present invention, adsorption of organic compounds contained in the packaged item (contents) can be suppressed, and the quality of the packaged item can be maintained for a long period of time.

[0028] <First Layer> The first layer contains a first polyester resin containing a first acid unit and a first alcohol unit, and preferably contains a second polyethylene resin.

[0029] The compositions of the first and second polyester resins may not necessarily be identical to the compositions of the raw material monomers. In particular, when ethylene glycol is used as the alcohol component, diethylene glycol is included as a by-product. Hereinafter, unless otherwise specified, the notation of mole percent (mol%) concentration indicating the composition refers to the mole percent concentration of the component contained in the produced polyester resin, not the amount of the raw material monomer charged.

[0030] In the present invention, unless otherwise specified, the first and second polyester resins may also include molded articles. The polyester resin is a copolymer of an acid unit (a polycarboxylic acid unit) and an alcohol unit (a polyol unit, a polyhydroxy compound unit). In the present invention, a polycarboxylic acid unit refers to a unit consisting of a compound having multiple carboxy groups. Furthermore, a polyol unit or a polyhydroxy compound unit refers to a unit consisting of a compound having multiple hydroxy groups. In the present specification and claims, each acid and each alcohol may also include its derivatives. For example, an acid may also include an acid derivative (e.g., an ester).

[0031] The first and second polyester resins may be made from scraps generated during film production, molding, or other processes. This allows for efficient resource utilization and reduced manufacturing costs. The scraps may be processed into an easily usable form, such as pellets, flakes, or powder. The first and second polyester resins may also contain components derived from recycled polyester resins or biomass.

[0032] The first polyester resin includes a first acid unit and a first alcohol unit, and is preferably composed primarily of polyethylene terephthalate (PET).

[0033] -First Acid Units- The first acid units mainly contain terephthalic acid units. The content of terephthalic acid units in the first acid units is 60 mol% or more relative to the total amount of first acid units. The content of terephthalic acid units in the first acid units can be, for example, 65 mol% or more, 70 mol% or more, or 75 mol% or more relative to the total amount of first acid units. If the content of terephthalic acid units is less than 60 mol%, the tensile elongation at break decreases, and low adsorption to organic compounds may deteriorate. The content of terephthalic acid units in the first acid units is 80 mol% or less relative to the total amount of first acid units. The content of terephthalic acid units in the first acid units can be, for example, 75 mol% or less, 70 mol% or less, or 65 mol% or less relative to the total amount of first acid units. If the content of terephthalic acid units exceeds 80 mol %, the seal strength when thermocompression bonded at low temperatures may decrease, and organic compounds may be more likely to be adsorbed.

[0034] The first acid units further contain isophthalic acid units. The content of isophthalic acid units in the first acid units is 20 mol% or more relative to the total amount of first acid units. The content of isophthalic acid units in the first acid units can be, for example, 25 mol% or more, 30 mol% or more, or 35 mol% or more relative to the total amount of first acid units. If the content of isophthalic acid units is less than 20 mol%, the seal strength when thermocompression bonded at low temperatures may decrease and organic compounds may be more likely to be adsorbed. The content of isophthalic acid units in the first acid units is 40 mol% or less relative to the total amount of first acid units. The content of isophthalic acid units in the first acid units can be, for example, 35 mol% or less, 30 mol% or less, or 25 mol% or less relative to the total amount of first acid units. If the content of isophthalic acid units exceeds 40 mol %, the toughness of the polyester film may decrease, and the low adsorption property to organic compounds may deteriorate.

[0035] In the first acid units, the total amount of terephthalic acid units and isophthalic acid units is preferably 90 mol % or more, more preferably 95 mol % or more, based on the total amount of the first acid units, and can be 100 mol % based on the total amount of the first acid units.

[0036] The first acid unit in the first polyester resin may contain other acid units as long as the essential properties of the first polyester resin of the present invention are not altered. Examples of other acid units include orthophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, succinic acid, dimer acid, 1,4-cyclohexadicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, and derivatives thereof. These may be used alone or in combination of two or more.

[0037] -First Alcohol Units- The first alcohol units mainly contain ethylene glycol units. The content of ethylene glycol units in the first alcohol units is 75 mol% or more relative to the total amount of first alcohol units. The content of ethylene glycol units in the first alcohol units can be 80 mol% or more, 85 mol% or more, 90 mol% or more, or 95 mol% or more. If the content of ethylene glycol units is less than 75 mol%, the seal strength during thermocompression bonding at low temperatures may decrease and organic compounds may be more likely to be adsorbed. The content of ethylene glycol units can be, for example, 98 mol% or less, 95 mol% or less, 90 mol% or less, 85 mol% or less, or 80 mol% or less relative to the total amount of first alcohol units in the first alcohol units.

[0038] The first alcohol units include diethylene glycol units by-produced from ethylene glycol units during melt polymerization. The content of the diethylene glycol units can be 1 mol % or more, or 2 mol % or more, relative to the total amount of the first alcohol units. The content of the diethylene glycol units can be, for example, 5 mol % or less, or 3 mol % or less, relative to the total amount of the first alcohol units.

[0039] The first alcohol units preferably contain 95 mol % to 99 mol % of ethylene glycol units and 1 mol % to 5 mol % of diethylene glycol units, based on the total amount of the first alcohol units.

[0040] The first alcohol units may further include 2,2-dimethyl-1,3-propanediol units (hereinafter, also referred to as "neopentyl glycol units"). The content of the neopentyl glycol units may be 5 mol% or more relative to the total amount of the first alcohol units. The content of the neopentyl glycol units may be, for example, 10 mol% or more, or 15 mol% or more relative to the total amount of the first alcohol units. The content of the neopentyl glycol units may be, for example, 20 mol% or less, 15 mol% or less, or 10 mol% or less relative to the total amount of the first alcohol units. If the content of the neopentyl glycol units exceeds 20 mol%, the low adsorption properties for organic compounds may be significantly deteriorated.

[0041] The first alcohol units preferably contain 75 mol % to 90 mol % of ethylene glycol units, 1 mol % to 5 mol % of diethylene glycol units, and 5 mol % to 20 mol % of 2,2-dimethyl-1,3-propanediol units, based on the total amount of the first alcohol units.

[0042] The total of the ethylene glycol units, diethylene glycol units, and neopentyl glycol units is preferably 90 mol% or more, more preferably 95 mol% or more, based on the total amount of the first alcohol units. The total of the ethylene glycol units, diethylene glycol units, and neopentyl glycol units can be 100 mol% based on the total amount of the first alcohol units.

[0043] The first alcohol unit may contain other alcohol units as long as the essential properties of the first polyester resin of the present invention are not altered. Examples of other alcohol units include 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and units formed from derivatives thereof. These may be used alone or in combination of two or more.

[0044] The first polyester resin may further contain a crosslinking agent unit. By copolymerizing the crosslinking agent unit, the melt viscosity of the first polyester resin can be increased. This stabilizes the amount of the first polyester resin discharged during polyester film formation, making it easier to form a polyester film with a uniform thickness.

[0045] Examples of the crosslinking agent unit include a trivalent carboxylic acid unit or a trivalent polyol unit. Examples of the trivalent or higher carboxylic acid unit include a trimellitic acid unit and a pyromellitic acid unit. Examples of the trivalent or higher polyol unit include a trimethylolethane unit and a trimethylolpropane unit.

[0046] The content of the crosslinking agent units can be, for example, 0.05 mol% or more, 0.1 mol% or more, or 0.15 mol% or more, relative to the total amount of the first acid units. The content of the crosslinking agent units is preferably 5 mol% or less, relative to the total amount of the first acid units. The content of the crosslinking agent units can be, for example, 4 mol% or less, 3.5 mol% or less, 3 mol% or less, 2.5 mol% or less, 2 mol% or less, 1.5 mol% or less, 1 mol% or less, or 0.5 mol% or less, relative to the total amount of the first acid units. If the content of the crosslinking agent units exceeds 5 mol%, the polyester film may become more prone to breakage.

[0047] The total of the terephthalic acid units, isophthalic acid units, and crosslinker units is preferably 90 mol% or more, more preferably 95 mol% or more, based on the total amount of the first acid units. The total of the terephthalic acid units, isophthalic acid units, and crosslinker units can be 100 mol% based on the total amount of the first acid units.

[0048] In the first polyester resin, the total amount of terephthalic acid units in the first polyester resin and ethylene glycol units and diethylene glycol units in the first polyester resin is preferably 150 mol% or more relative to a total amount of the first acid units and first alcohol units in the first polyester resin (200 mol%). The total amount of terephthalic acid units in the first polyester resin and ethylene glycol units and diethylene glycol units in the first polyester resin is preferably 180 mol% or less relative to a total amount of the first acid units and first alcohol units in the first polyester resin (200 mol%). If the total amount of terephthalic acid units and ethylene glycol units and diethylene glycol units exceeds 180 mol%, the seal strength may decrease when thermocompression bonding is performed at low temperatures.

[0049] The first polyester resin has a viscosity of 10.70 cal / cm ３ The first polyester resin preferably has an SP value (solubility parameter) of 15 cal / cm or more. ３ The first polyester resin preferably has an SP value of 10.70 cal / cm. ３ If the amount is less than 1000 ppm, the low adsorption of non-lipid-soluble organic compounds such as methyl salicylate may be deteriorated.

[0050] By making the SP value of the first polyester resin in the polyester film of the present invention higher than the SP value (see Table A below) of organic compounds (hereinafter sometimes referred to as "medicinal ingredients") in the packaged item, such as camphor, menthol, methyl salicylate, etc., adsorption of the organic compounds in the first polyester resin can be suppressed.

[0051]

[0052] Here, the SP value can be calculated, for example, based on the Fedors method (the method described in Polym. Eng. Sci. 14(2), 1974, 147-154).

[0053] According to the above document, the SP value δsp can be calculated from the following formula:

[0054] where E is the enthalpy of vaporization, and V' is the corrected molar volume when the glass transition temperature is 25°C or higher.

[0055] Since the glass transition temperature of the first polyester resin in the polyester film of the present invention is 25° C. or higher, the SP value can be calculated using the corrected molar volume. The vaporization enthalpy and corrected molar volume of the copolymer polyester represented by the following chemical formula can be a weighted average of each unit structure.

[0056] For the chemical structure represented by the above chemical formula, the vaporization enthalpy E and corrected molar volume V' can be expressed by the following formulas.

[0057]

[0058]

[0059] The content of the first polyester resin in the first layer can be 70% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass, based on the mass of the first layer. If the content of the first polyester resin is less than 70% by mass, sufficient sealing strength and excellent low adsorption to organic compounds cannot be obtained. The first layer preferably contains 5% to 30% by mass of the second polyester resin based on the mass of the first layer. The thickness of the first layer is preferably 2 μm to 15 μm, more preferably 5 μm to 10 μm. The SP value of the first layer is 10.70 cal / cm ３ ~15 cal / cm ３ It is preferable that the ３ ~15 cal / cm ３ It is more preferable that:

[0060] <Second Layer> The second layer contains a second polyester resin containing second acid units including terephthalic acid units and second alcohol units including ethylene glycol units and diethylene glycol units, and preferably contains a first polyethylene resin, and further contains other resins as necessary. The second polyester resin preferably contains polyethylene terephthalate (PET) as a main constituent unit.

[0061] - Second Acid Units - The second acid units mainly contain terephthalic acid units. The content of terephthalic acid units in the second acid units is preferably 90 mol% or more relative to the total amount of second acid units. The content of terephthalic acid units in the second acid units can be, for example, 95 mol% or more, or 100 mol% relative to the total amount of second acid units. If the content of terephthalic acid units is less than 90 mol%, the excellent low adsorption properties for organic compounds may be impaired. The content of terephthalic acid units in the second acid units can be, for example, 95 mol% or less relative to the total amount of second acid units.

[0062] The second acid units may further include isophthalic acid units. The content of the isophthalic acid units in the second acid units may be, for example, 0.5 mol% or more, 1 mol% or more, 2 mol% or more, or 3 mol% or more, relative to the total amount of the second acid units. The content of the isophthalic acid units in the second acid units may be, for example, 10 mol% or less, 8 mol% or less, 6 mol% or less, 5 mol% or less, 4 mol% or less, 3 mol% or less, or 2 mol% or less, relative to the total amount of the second acid units.

[0063] When the second acid units contain isophthalic acid units, the total amount of terephthalic acid units and isophthalic acid units is preferably 95 mol % or more relative to the total amount of second acid units, and the total amount of terephthalic acid units and isophthalic acid units can be 100 mol % relative to the total amount of second acid units.

[0064] The second acid unit in the second polyester resin may contain other acid units as long as the essential properties of the second polyester resin of the present invention are not altered. Examples of other acid units include orthophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, succinic acid, dimer acid, 1,4-cyclohexadicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, trimellitic acid, and units formed from derivatives thereof. These may be used alone or in combination of two or more.

[0065] - Second alcohol units - The second alcohol units mainly contain ethylene glycol units. The content of ethylene glycol units in the second alcohol units can be 90 mol % or more, or 95 mol % or more, relative to the total amount of second alcohol units. The content of ethylene glycol units can be, for example, 98 mol % or less, or 95 mol % or less, relative to the total amount of second alcohol units in the second alcohol units.

[0066] The second alcohol units include diethylene glycol units by-produced from ethylene glycol units during melt polymerization. The content of the diethylene glycol units can be 1 mol % or more, or 2 mol % or more, relative to the total amount of the second alcohol units. The content of the diethylene glycol units can be, for example, 5 mol % or less, or 3 mol % or less, relative to the total amount of the second alcohol units.

[0067] The second alcohol units preferably contain 95 mol % to 99 mol % of ethylene glycol units and 1 mol % to 5 mol % of diethylene glycol units, based on the total amount of the second alcohol units.

[0068] The total amount of ethylene glycol units and diethylene glycol units is preferably 90 mol% or more, more preferably 95 mol% or more, based on the total amount of second alcohol units. The total amount of ethylene glycol units and diethylene glycol units can be 100 mol% based on the total amount of second alcohol units.

[0069] The second alcohol unit may contain other alcohol units as long as the essential properties of the second polyester resin of the present invention are not altered. Examples of other alcohol units include units consisting of 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, or derivatives thereof. These may be used alone or in combination of two or more.

[0070] In the second polyester resin, the total amount of the terephthalic acid units in the second polyester resin and the ethylene glycol units and diethylene glycol units in the second polyester resin is preferably 190 mol% or more, more preferably 195 mol% or more, relative to the total amount of the second acid units and second alcohol units in the second polyester resin (200 mol%). If the total amount of the terephthalic acid units, ethylene glycol units, and diethylene glycol units is less than 190 mol%, the adsorption of organic compounds may increase.

[0071] The total amount of the terephthalic acid units in the second polyester resin and the ethylene glycol units and diethylene glycol units in the second polyester resin is 95% or more, preferably 98% or more, and more preferably 100%, of the total amount of the second acid units and the second alcohol units. If the total amount of the terephthalic acid units in the second polyester resin and the ethylene glycol units and diethylene glycol units in the second polyester resin is less than 95% of the total amount of the second acid units and the second alcohol units, the low adsorption to organic compounds may deteriorate, and the toughness of the polyester film may decrease.

[0072] The second polyester resin has a viscosity of 10.70 cal / cm ３ The second polyester resin preferably has an SP value of 15 cal / cm or more. ３ It is preferred that the SP value be as follows:

[0073] The content of the second polyester resin in the second layer can be 90% by mass or more, 95% by mass or more, or 100% by mass relative to the mass of the second layer. If the content of the second polyester resin is less than 90% by mass, the seal strength and low adsorption to organic compounds will deteriorate. The second layer preferably contains the first polyester resin in an amount of 5% by mass or more but less than 10% by mass relative to the mass of the second layer. The thickness of the second layer is preferably 18 μm to 85 μm, more preferably 25 μm to 70 μm. The SP value of the second layer is 10.70 cal / cm ３ ~15 cal / cm ３ It is preferable that the ３ ~15 cal / cm ３ It is more preferable that:

[0074] <Third Layer> The polyester film of the present invention preferably has a third layer between the first layer and the second layer. The third layer preferably contains a second polyester resin. The content of the second polyester resin in the third layer can be 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass relative to the mass of the third layer. If the content of the second polyester resin is less than 50% by mass, the seal strength and low adsorption to organic compounds will deteriorate. The third layer preferably contains 5% by mass or more but less than 50% by mass of the first polyester resin relative to the mass of the third layer. The SP value of the third layer is 10.70 cal / cm ３ ~15 cal / cm ３ It is preferable that the ３ ~15 cal / cm ３ The thickness of the third layer is preferably 5 μm to 30 μm, and more preferably 5 μm to 20 μm.

[0075] <Other Layers> The other layers are not particularly limited, and examples thereof include a protective layer and an adhesive layer.

[0076] <Method for producing polyester resin> The first polyester resin and the second polyester resin used in the polyester film of the present invention can be produced by a known method using the above-mentioned monomers, etc. For example, an ester prepolymer may be produced by direct esterification using an unsubstituted polycarboxylic acid as a starting material, or an ester prepolymer may be produced by transesterification using an esterified product such as dimethyl ester as a starting material. From the viewpoint of production efficiency, direct esterification is preferred.

[0077] The amounts of the monomers added may be the ratios shown in the above description of the first polyester resin and the second polyester resin.

[0078] The direct esterification reaction or transesterification reaction can be carried out, for example, by charging raw materials into a reaction vessel equipped with a heater, a stirrer, and a distillation tube, adding a reaction catalyst, and raising the temperature while stirring under an inert gas atmosphere at atmospheric pressure, and allowing the reaction to proceed while distilling off by-products such as methanol produced by the reaction. The reaction temperature can be, for example, 150°C to 270°C, and preferably 160°C to 260°C. The reaction time is, for example, about 3 to 7 hours.

[0079] At least one metal compound can be used as the transesterification catalyst. Examples of metal elements in the metal compound include sodium, potassium, calcium, titanium, lithium, magnesium, manganese, zinc, tin, and cobalt. Among these, titanium and manganese compounds are preferred because they have high reactivity and produce a good color tone for the resulting resin. The amount of the transesterification catalyst added is preferably 5 ppm to 1,000 ppm, and more preferably 10 ppm to 100 ppm, relative to the polyester resin produced.

[0080] To suppress the production of the by-product diethylene glycol, it is preferable to reduce the amount of ethylene glycol in the reaction system. For example, it is preferable to set the molar ratio of alcohol units to acid units (alcohol units / acid units) to 1.3 or less. Furthermore, the production of diethylene glycol can be suppressed by adding, for example, 5 ppm of sodium hydroxide.

[0081] Furthermore, it is preferable to add a phosphorus compound after the completion of the direct esterification reaction or the transesterification reaction to further promote the esterification reaction. Examples of phosphorus compounds include phosphoric acid, phosphorous acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trimethyl phosphite, triethyl phosphite, and tributyl phosphite. Among these, trimethyl phosphate is preferred. The amount of the phosphorus compound added is preferably 5 ppm to 1,000 ppm, and more preferably 20 ppm to 100 ppm, based on the mass of the polyester resin to be synthesized.

[0082] Among the alcohol units, neopentyl glycol may be added during the direct esterification reaction of the polycarboxylic acid units with ethylene glycol, or may be added after the esterification reaction is completed. It is preferable to first mix the polycarboxylic acid units with ethylene glycol and neopentyl glycol at room temperature to prepare a slurry, and then proceed with the esterification reaction in an esterification reaction tank, since this can prevent the neopentyl glycol from scattering. Furthermore, the entire amount of ethylene glycol may be added before the esterification reaction, and it is not necessary to add a portion of it after the esterification reaction.

[0083] Following the transesterification and esterification reactions, a polymerization catalyst can be added to the ester prepolymer, and a polycondensation reaction can be further carried out until the desired molecular weight is achieved. For example, germanium dioxide can be used as a catalyst in the polycondensation reaction. The catalyst addition rate can be, for example, 180 ppm to 220 ppm based on the total amount of polyester resin produced.

[0084] The polycondensation reaction can be carried out, for example, by adding a polymerization catalyst and gradually increasing the temperature and reducing the pressure inside the reaction tank. The pressure inside the tank is preferably reduced to, for example, 0.4 kPa or less, and preferably 0.2 kPa or less. The temperature inside the tank is preferably increased to, for example, 250°C to 290°C. The polycondensation reaction can be carried out, for example, under reduced pressure so that the final tank pressure is 150 Pa or less until a predetermined melt viscosity is achieved. Thereafter, the tank pressure can be increased to, for example, 0.5 MPa, and the reaction product can be extruded and recovered from the bottom of the tank. For example, the reaction product can be extruded into water in the form of a strand, cooled, and then cut to obtain a pellet-shaped polyester resin.

[0085] As the polymerization catalyst, a catalyst other than germanium dioxide can also be used. For example, titanium dioxide can be used as the polymerization catalyst. When titanium dioxide is used, the amount of catalyst added can be, for example, 1 ppm to 10 ppm based on the total amount of polyester resin produced.

[0086] <Other Components> Depending on the application and molding purpose, the polyester film of the present invention may contain various additives, such as an antiblocking agent, an antioxidant, a release agent, a heat stabilizer, a lubricant, an antistatic agent, a plasticizer, an ultraviolet absorber, a pigment, etc. These additives may be added in either the polymerization reaction step or the processing / molding step.

[0087] Anti-blocking (slip) agents are blended to improve the slippage between films. As the anti-blocking agent, organic or inorganic fine particles can be used, and examples thereof include inorganic particles such as calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, lithium phosphate, magnesium phosphate, calcium phosphate, lithium fluoride, aluminum oxide (alumina), silicon oxide (silica), talc, and kaolin; organic particles such as acrylic resin and guanamine resin; and precipitated particles obtained by granulating catalyst residues. These may be used alone or in combination of two or more.

[0088] Examples of antioxidants include phosphite-based antioxidants, phenol-based antioxidants, sulfur-based antioxidants, epoxy-based antioxidants, hindered phenol-based antioxidants, hindered amine-based antioxidants, amine-based antioxidants, etc. These may be used alone or in combination of two or more.

[0089] <Method for producing polyester film> The method for producing the polyester film of the present invention is not particularly limited and can be appropriately selected depending on the purpose. For example, a polyester film (unstretched product) can be produced by mixing the first polyester resin, the second polyester resin, and, if necessary, other components, feeding the mixture into an extruder equipped with a T-die, melting the mixture, extruding the mixture through the T-die, bringing the mixture into contact with a cooling roll by electrostatic adhesion or the like, and cooling and solidifying the mixture. In this case, the temperature of the extruder is preferably 200°C to 280°C.

[0090] The polyester film of the present invention is preferably an unstretched product. An unstretched product refers to a polyester film that has not been stretched during the manufacturing process. The unstretched product can be confirmed by a tensile test conducted at 23°C and 10 mm / min, where the tensile elongation at break is 200% or more in both the longitudinal and width directions. The longitudinal direction is sometimes referred to as the machine direction (MD). The width direction is sometimes referred to as the transverse direction (TD). An unstretched product (unstretched film) can achieve high seal strength even at a wide temperature range, for example, a sealing temperature of 110°C to 150°C. Furthermore, by using an unstretched film, heat shrinkage in the stretching direction can be prevented. As a result, the unstretched film is less likely to wrinkle when heated, improving moldability.

[0091] The thickness of the polyester film of the present invention is preferably 20 μm to 100 μm, more preferably 25 μm to 100 μm, still more preferably 30 μm to 80 μm, and particularly preferably 30 μm to 60 μm. The thickness of the polyester film is an average value obtained by measuring the thickness of any five points of the polyester film with a micrometer.

[0092] The SP value of the polyester film of the present invention is 10.70 cal / cm ３ ~15 cal / cm ３ It is preferable that the ３ ~15 cal / cm ３ The SP value of the polyester film is more preferably 10.70 cal / cm ３ If the SP value is less than 100%, the low adsorption of non-fat-soluble organic compounds such as methyl salicylate may be deteriorated. The SP value of the polyester film is a value calculated based on the above-mentioned Fedors method (Polym. Eng. Sci. 14(2), 1974, 147-154).

[0093] In the polyester film of the present invention, when two polyester films 1 and 2 are thermocompression bonded together under conditions of 110°C to 150°C, 0.2 MPa, and 2 seconds, the seal strength (sometimes referred to as "peel strength") between polyester film 1 and polyester film 2 is preferably 15 N / 15 mm or more, more preferably 20 N / 15 mm or more. The seal strength can also be 50 N / 15 mm or less. The seal strength can be measured, for example, using a tensile tester.

[0094] The polyester film of the present invention preferably has a crystallinity of 5% or more. It also preferably has a crystallinity of 15% or less, or 10% or less. If the crystallinity exceeds 15%, the seal strength during thermocompression bonding at low temperatures may decrease, or the toughness of the polyester film may deteriorate.

[0095] The crystallinity can be calculated using the following formula by measuring the crystallization enthalpy (ΔHc), recrystallization enthalpy (ΔHc'), and melting enthalpy (ΔHm) of a polyester film in nitrogen using a DSC apparatus, while temperature-modulating the film from 20°C to 300°C at an average temperature-rising rate of 5°C / min, a modulation period of 80 seconds, and a modulation temperature amplitude of 1.0°C.

[0096]

[0097] Other characteristics of the polyester film of the present invention may be difficult or impractical to directly identify by its composition, such as its structure. In such cases, the polyester film of the present invention should be allowed to be identified by its manufacturing method. For example, the composition and properties of the polyester film may change from the polyester resin before molding depending on the heat-melting conditions during polyester film production. In some cases, it is difficult to directly identify the composition and properties of the molded product. In such cases, it is useful to identify the polyester film by the manufacturing method from the polyester resin before molding to the polyester film.

[0098] Here, embodiments of the polyester film of the present invention will be described in detail with reference to the drawings. In the following description, reference symbols in the drawings are added to facilitate understanding of the invention and are not intended to limit the invention to the illustrated embodiments. Furthermore, the shapes, dimensions, scales, etc. of the drawings are not intended to limit the invention to the embodiments shown in the drawings. In each embodiment, the same elements are designated by the same symbols.

[0099] <First Embodiment> Fig. 1 shows a schematic diagram of a polyester film according to a first embodiment. A polyester film 10 according to the first embodiment has a first layer 11 and a second layer 12. The first layer 11 and the second layer 12 are laminated together. In this embodiment, a two-layer unstretched polyester film is described, but the polyester film of this embodiment may be a multilayer film having two or more layers (e.g., three layers, four layers, etc.). Furthermore, when producing a multilayer polyester film, it may be produced by coextrusion or lamination.

[0100] The first layer 11 includes a first polyester resin which is a polymer of a first acid unit and a first alcohol unit. The first layer 11 preferably includes 70% by mass or more of the first polyester resin relative to the mass of the first layer 11. The content of the first polyester resin may be 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass relative to the mass of the first layer 11. If the content of the first polyester resin is less than 70% by mass, sufficient sealing strength and excellent low adsorption to organic compounds cannot be obtained.

[0101] The second layer 12 contains a second polyester resin which is a polymer of a second acid unit and a second alcohol unit. The second layer 12 preferably contains 90% by mass or more of the second polyester resin relative to the mass of the second layer 12. The content of the second polyester resin can be 95% by mass or more, or 100% by mass, relative to the mass of the second layer 12. If the content of the second polyester resin is less than 90% by mass, the seal strength and low adsorption to organic compounds will be deteriorated.

[0102] The thickness T0 of the polyester film 10 according to the first embodiment is 20 μm or more, preferably 25 μm or more. If the thickness T0 of the polyester film 10 is less than 20 μm, the seal strength may decrease, and the functionality as a packaging material may be significantly reduced. The thickness T0 of the polyester film 10 according to the first embodiment is preferably 100 μm or less. If the thickness T0 of the polyester film 10 exceeds 100 μm, the adsorption of organic compounds becomes significantly high. The thickness T0 of the polyester film 10 can be measured, for example, using a micrometer (manufactured by Mitutoyo Corporation).

[0103] The thickness t1 of the first layer 11 is preferably 2 μm or more. The thickness t1 of the first layer 11 can be, for example, 4 μm or more, 6 μm or more, 8 μm or more, 10 μm or more, or 12 μm or more. If the thickness t1 of the first layer 11 is less than 2 μm, sufficient seal strength cannot be obtained after thermocompression bonding at low temperatures. The thickness t1 of the first layer 11 is preferably 15 μm or less. The thickness t1 of the first layer 11 can be, for example, 13 μm or less, 11 μm or less, 9 μm or less, 7 μm or less, or 5 μm or less. If the thickness t1 of the first layer 11 exceeds 15 μm, the adsorption of organic compounds becomes high. The thickness of each layer can be measured, for example, by observing the cross section or side surface of each layer with a scanning electron microscope (SEM).

[0104] Second Embodiment A polyester film according to a second embodiment of the present invention will be described. In the polyester film 10 according to the second embodiment, at least one layer selected from the first layer 11 and the second layer 12 in the polyester film according to the first embodiment contains a plurality of polyester resins.

[0105] The first layer 11 may contain a second polyester resin in addition to the first polyester resin. The first polyester resin and the second polyester resin are the same as those described in the first embodiment, and therefore, description thereof will be omitted here.

[0106] The first layer 11 preferably contains 70% by mass or more of the first polyester resin relative to the mass of the first layer 11. The content of the first polyester resin may be 75% by mass or more, 80% by mass or more, 85% by mass or more, or 90% by mass or more relative to the mass of the first layer 11. The content of the first polyester resin may be 95% by mass or less, 90% by mass or less, or 85% by mass or less relative to the mass of the first layer 11. If the content of the first polyester resin is less than 70% by mass, the seal strength decreases when thermocompression bonding is performed at low temperatures.

[0107] The first layer 11 preferably contains 5% by mass or more of the second polyester resin relative to the mass of the first layer 11. The content of the second polyester resin may be 10% by mass or more, 15% by mass or more, or 20% by mass or more relative to the mass of the first layer 11. The content of the second polyester resin is preferably 30% by mass or less relative to the mass of the first layer 11. The content of the second polyester resin may be 25% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or 5% by mass or less relative to the mass of the first layer 11. If the content of the second polyester resin exceeds 30% by mass, the seal strength decreases when thermocompression bonding is performed at low temperatures.

[0108] The total mass of the first polyester resin and the second polyester resin in the first layer 11 can be 90% by mass or more, or 95% by mass or more, relative to the mass of the first layer 11. The total mass of the first polyester resin and the second polyester resin in the first layer 11 is preferably 100% by mass, relative to the mass of the first layer 11. The total mass of the first polyester resin and the second polyester resin in the first layer 11 can be 95% by mass or less, relative to the mass of the first layer 11.

[0109] By adding the second polyester resin to the first layer 11, the low adsorption property of the first layer 11 to organic compounds can be improved.

[0110] The second layer 12 may contain the first polyester resin in addition to the second polyester resin. The first polyester resin and the second polyester resin are the same as those described in the first embodiment, and therefore, description thereof will be omitted here.

[0111] The second layer 12 preferably contains 90% by mass or more of the second polyester resin relative to the mass of the second layer 12. The content of the second polyester resin can be 95% by mass or more relative to the mass of the second layer 12. The content of the second polyester resin can be 95% by mass or less relative to the mass of the second layer 12. If the content of the second polyester resin is less than 90% by mass, the adsorption of organic compounds becomes excessive.

[0112] The second layer 12 preferably contains 5% by mass or more of the first polyester resin relative to the mass of the second layer 12. The content of the first polyester resin is preferably 10% by mass or less relative to the mass of the second layer 12. The content of the second polyester resin can be 10% by mass or less relative to the mass of the second layer 12. If the content of the first polyester resin exceeds 10% by mass, the adsorption of organic compounds increases.

[0113] The total mass of the first polyester resin and the second polyester resin in the second layer 12 can be 90% by mass or more, or 95% by mass or more, relative to the mass of the second layer 12. The total mass of the first polyester resin and the second polyester resin in the second layer 12 is preferably 100% by mass, relative to the mass of the second layer 12. The total mass of the first polyester resin and the second polyester resin in the second layer 12 can be 95% by mass or less, relative to the mass of the second layer 12.

[0114] Other aspects of the second embodiment than those described above can be the same as those of the first embodiment.

[0115] The polyester film according to the second embodiment can achieve the same effects as the polyester film according to the first embodiment.

[0116] Third Embodiment A polyester film according to a third embodiment of the present invention will be described. The polyester film according to the third embodiment is an unstretched product similar to those in the first and second embodiments.

[0117] Figure 2 shows a schematic diagram of a polyester film according to a third embodiment. The polyester film 20 according to the third embodiment may have three or more layers. For example, as shown in Figure 2, the polyester film 20 according to the third embodiment may have a first layer 21, a second layer 22, and a third layer 23. The first layer 21, the second layer 22, and the third layer 23 are laminated together.

[0118] The first layer 21 in the third embodiment can be similar to the first layer 11 in the first embodiment.

[0119] The second layer 22 in the third embodiment can be similar to the second layer 12 in the first embodiment.

[0120] The third layer 23 in the third embodiment can be similar to the second layer 12 in the first embodiment.

[0121] Other aspects of the third embodiment than those described above can be the same as those of the first embodiment.

[0122] The polyester film according to the third embodiment can achieve the same effects as the polyester film according to the first embodiment.

[0123] Fourth Embodiment A polyester film according to a fourth embodiment will be described. In the polyester film 20 according to the fourth embodiment, at least one layer selected from the first layer 21, the second layer 22, and the third layer 23 in the polyester film according to the third embodiment contains a plurality of polyester resins.

[0124] The first layer 21 in the fourth embodiment can be similar to the first layer 11 in the second embodiment.

[0125] The third layer 23 in the fourth embodiment can be similar to the second layer 12 in the second embodiment.

[0126] The second layer 22 in the fourth embodiment may contain a first polyester resin in addition to the second polyester resin. The first polyester resin and the second polyester resin are the same as those described in the first embodiment, and therefore, description thereof will be omitted here.

[0127] The second layer 22 preferably contains 50% by mass or more of the second polyester resin relative to the mass of the second layer 22. The content of the second polyester resin can be, for example, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 95% by mass or more relative to the mass of the second layer 22. If the content of the second polyester resin is less than 50% by mass, the adsorption of organic compounds will be excessive. The content of the second polyester resin can be, for example, 95% by mass or less, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less relative to the mass of the second layer 22.

[0128] The second layer 22 preferably contains 5% by mass or more of the first polyester resin relative to the mass of the second layer 22. The content of the first polyester resin can be, for example, 10% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more relative to the mass of the second layer 22. The content of the first polyester resin is preferably 50% by mass or less relative to the mass of the second layer 22. The content of the first polyester resin can be, for example, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less relative to the mass of the second layer 22. If the content of the first polyester resin exceeds 50% by mass, the adsorption of organic compounds increases.

[0129] The total mass of the first polyester resin and the second polyester resin in the second layer 22 can be 90% by mass or more, or 95% by mass or more, relative to the mass of the second layer 22. The total mass of the first polyester resin and the second polyester resin in the second layer 22 is preferably 100% by mass, relative to the mass of the second layer 22. The total mass of the first polyester resin and the second polyester resin in the second layer 22 can be 95% by mass or less, relative to the mass of the second layer 22.

[0130] Other aspects of the fourth embodiment than those described above can be the same as those of the first, second, and third embodiments.

[0131] The polyester film according to the fourth embodiment can achieve the same effects as the polyester film according to the first embodiment.

[0132] (Laminate) The laminate of the present invention has a base film, a sealant layer, and optionally other layers, and is suitable for use in packaging applications.

[0133] <Sealant Layer> The polyester film of the present invention is used as the sealant layer. The sealant layer is provided on the outermost surface of the laminate, and can be provided on one or both sides of the base film.

[0134] <Substrate Film> The material, thickness, structure, etc. of the substrate film are not particularly limited and can be appropriately selected depending on the purpose. Examples of the structure include a single-layer structure and a multi-layer structure. Examples of the substrate material include polyester resin, polyolefin resin, polyamide resin, polyurethane resin, fluororesin, polystyrene resin, poly(meth)acrylic resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), vinyl alcohol resin, halogen-containing resin (polyvinyl chloride resin, etc.), polyphenylene ether resin, polycarbonate resin, polyimide resin, polyamideimide resin, polyarylphthalate resin, silicone resin, polysulfone resin, acetal resin, and cellulose resin. These may be used alone or in combination of two or more. The thickness of the substrate film is preferably 1 μm to 100 μm, more preferably 5 μm to 50 μm.

[0135] <Other Layers> Examples of the other layers include a metal layer, an adhesive layer, a primer layer, a resin layer, etc. Examples of the metal layer include an aluminum foil, an aluminum vapor-deposited film, etc.

[0136] (Package) The package of the present invention includes the polyester film of the present invention, and at least a portion of the polyester film is fused to each other. Examples of the package include a package for food and drink, a package for cosmetics, and a package for medicines and quasi-drugs.

[0137] - Food and drink package - The food and drink package of the present invention comprises the polyester film of the present invention and a food or drink covered with the polyester film.

[0138] Depending on the application, only a portion of the food and beverage package may be made of the packaging material (the polyester film of the present invention), or substantially the entire food and beverage package may be made of the packaging material. Examples of the shape of the food and beverage package include a bag, tray, pack, pouch, container, etc. The food and beverage package is used to package various foods and beverages. In the present invention, the food and drink examples include, but are not limited to, beverages such as soft drinks, carbonated drinks, nutritional drinks, fruit drinks, and lactic acid drinks (including concentrated concentrates and powders for adjusting these beverages); frozen desserts such as ice cream, ice sherbet, and shaved ice; noodles such as soba noodles, udon noodles, vermicelli, gyoza wrappers, shumai wrappers, Chinese noodles, and instant noodles; sweets such as candy, chewing gum, candies, chewing gum, chocolate, candy tablets, snacks, biscuits, jelly, jam, cream, and baked goods; processed seafood and livestock foods such as kamaboko, ham, and sausage; dairy products such as processed milk and fermented milk; oils and fats and oil-based foods such as seafood, salad oil, tempura oil, margarine, mayonnaise, shortening, whipped cream, and dressing; condiments such as sauces and dressings; soups, stews, salads, side dishes, and pickles; various other forms of health and nutritional supplements; and energy drinks.

[0139] - Cosmetic Package - The cosmetic package according to the present invention comprises the polyester film of the present invention and a cosmetic product covered with the polyester film.

[0140] Depending on the intended use, the cosmetic package may be partially or entirely made of the packaging material (the polyester film of the present invention). Examples of the cosmetic package include a bag, tray, pack, and container. The cosmetic package is used to package various cosmetics. In the present invention, the cosmetics are not particularly limited, but examples thereof include perfume, cream, emulsion, skin lotion, lotion, face mask, foundation, lip balm, lipstick, hair tonic, hair lotion, shampoo, rinse, and conditioner.

[0141] - Pharmaceutical / quasi-drug package - The pharmaceutical / quasi-drug package of the present invention comprises the polyester film of the present invention and a pharmaceutical / quasi-drug covered with the polyester film.

[0142] Depending on the intended use, the pharmaceutical / quasi-drug package may be partially or entirely composed of the packaging material (the polyester film of the present invention). Examples of the pharmaceutical / quasi-drug package include blister packs, bags, trays, packs, and containers. The pharmaceutical / quasi-drug package is used to package various pharmaceuticals and quasi-drugs. In the present invention, pharmaceuticals and quasi-drugs refer to pharmaceuticals and quasi-drugs defined in Article 2, Paragraphs 1 and 2 of the Pharmaceutical and Medical Device Act. These pharmaceuticals and quasi-drugs may be in oral dosage forms such as liquids, suspensions, tablets, capsules, and powders, or parenteral dosage forms such as ointments, patches, poultices, dentifrices, mouthwashes, mouth fresheners, gels, ointments, gargle tablets, sprays, and aerosols.

[0143] (Product) The product of the present invention includes a packaged item (content) containing an organic compound and the polyester film of the present invention that packages the packaged item, with at least a portion of the polyester film fused together. The packaged item is preferably completely surrounded (sealed) by the polyester film. According to the product of the present invention, it is possible to suppress adsorption of organic compounds contained in the packaged item by the polyester film, which is a packaging material. This allows the quality of the packaged item to be maintained.

[0144] The SP value of the polyester film is preferably greater than the SP value of the organic compound contained in the package. The difference in SP value (SP value of the polyester film - SP value of the organic compound) is 0.05 cal / cm ３ It is preferable that the calorie content is 0.1 cal / cm or more. ３ More preferably, it is 0.5 cal / cm or more. ３ It is more preferable that the SP value of the polyester film is greater than the SP value of the organic compounds contained in the packaged goods. If the SP value of the polyester film is greater than the SP value of the organic compounds contained in the packaged goods, the adsorption of the organic compounds contained in the packaged goods can be suppressed. The SP value can be calculated based on the above-mentioned Fedors method (Polym. Eng. Sci. 14(2), 1974, 147-154).

[0145] The organic compound has an SP value of 10.65 cal / cm ３ Preferably, it is 10.60 cal / cm or less. ３ More preferably, it is 10.50 cal / cm or less. ３ It is more preferable that:

[0146] Examples of organic compounds include camphor (SP value: 9.45 cal / cm ３ ), menthol (SP value: 9.94 cal / cm ３ ), methyl salicylate (SP value: 10.62 cal / cm ３), limonene, tocopherol acetate, isopropylmethylphenol, ketoprofen, ketoprofen sodium, diclofenac sodium, felbinac, loxoprofen sodium, tulobuterol, rivastigmine, clopumazine hydrochloride, haloperidol, risperidone, paliperidone, blonanserin, perospirone hydrochloride hydrate, lurasidone hydrochloride, olanzapine, quetiapine fumarate, asenapine maleate, clozapine, aripiprazole, brexpiprazole, etc. These may be used alone or in combination of two or more.

[0147] Camphor can be used, for example, as a blood circulation improver, anti-inflammatory agent, analgesic, etc. Examples of packaged items containing camphor as an organic compound include pharmaceuticals and quasi-drugs such as patches.

[0148] Menthol can be used, for example, as a fragrance, a flavoring agent, a deodorant, etc. Examples of packaged items containing menthol as an organic compound include pharmaceuticals such as patches, quasi-drugs, dentifrices, cosmetics, beverages, and foods such as confectionery.

[0149] Methyl salicylate can be used, for example, as an analgesic, an anti-inflammatory agent, etc. Examples of packaged items containing methyl salicylate as an organic compound include pharmaceuticals and quasi-drugs such as patches.

[0150] Limonene can be used, for example, as a citrus fragrance, etc. Examples of packaged items containing limonene as an organic compound include hair care cosmetics and skin care cosmetics.

[0151] Tocopherol acetate can be used, for example, as a therapeutic agent for vitamin E deficiency, a blood circulation promoter, etc. Examples of packaged items containing tocopherol acetate as an organic compound include pharmaceuticals and quasi-drugs such as patches.

[0152] Isopropylmethylphenol can be used, for example, as a disinfectant, etc. Examples of packaged items containing isopropylmethylphenol as an organic compound include external skin preparations such as ointments, cosmetics, etc.

[0153] Ketoprofen, ketoprofen sodium, and loxoprofen sodium can be used, for example, as an anti-inflammatory agent, analgesic, antipyretic, etc. Packaged items containing ketoprofen, ketoprofen sodium, or loxoprofen sodium as an organic compound include, for example, pharmaceuticals and quasi-drugs such as patches.

[0154] Diclofenac sodium and felbinac can be used, for example, as an anti-inflammatory agent, an analgesic, etc. Packaged items containing diclofenac sodium or felbinac as an organic compound include, for example, pharmaceuticals and quasi-drugs such as patches.

[0155] Tulobuterol can be used, for example, as a bronchodilator, etc. Examples of packaged items containing tulobuterol as an organic compound include pharmaceuticals and quasi-drugs such as patches.

[0156] Rivastigmine can be used, for example, as a therapeutic agent for Alzheimer's disease, etc. Examples of packaged items containing rivastigmine as an organic compound include pharmaceuticals and quasi-drugs such as patches.

[0157] Clopumazine hydrochloride and haloperidol can be used, for example, as antipsychotic drugs, etc. Packaged items containing clopmazine hydrochloride or haloperidol as an organic compound include, for example, pharmaceuticals such as antipsychotic drugs.

[0158] Risperidone, paliperidone, blonanserin, perospirone hydrochloride hydrate, and lurasidone hydrochloride can be used, for example, as an SDA (serotonin dopamine antagonist), etc. Packaged items containing risperidone, paliperidone, blonanserin, perospirone hydrochloride hydrate, or lurasidone hydrochloride as an organic compound include, for example, pharmaceuticals such as antipsychotic drugs.

[0159] Olanzapine, quetiapine fumarate, asenapine maleate, and clozapine can be used, for example, as MARTA (multi-receptor acting antipsychotics), etc. Packaged items containing olanzapine, quetiapine fumarate, or clozapine as an organic compound include, for example, pharmaceuticals such as antipsychotic drugs.

[0160] Aripiprazole and brexpiprazole can be used, for example, as DPA / DSS (dopamine partial agonists), etc. Packaged items containing aripiprazole or brexpiprazole as an organic compound include, for example, pharmaceuticals such as antipsychotic drugs.

[0161] Examples of the present invention will be described below, but the present invention is not limited to these examples in any way.

[0162] Synthesis Example 1 - Synthesis of Polyester Resin - A stainless steel (registered trademark) autoclave equipped with a stirrer and a distillation column was charged with 77 mol % terephthalic acid and 23 mol % isophthalic acid as acids, and 100 mol % ethylene glycol as alcohol, and esterification was carried out under conditions of 250°C and 250 kPa. Thereafter, triethyl phosphate and germanium dioxide were charged, and a polycondensation reaction was carried out to a predetermined viscosity at 275°C and a reduced pressure of 100 Pa. Next, the obtained polycondensate was extruded into cooling water and pelletized using a strand cutter. The obtained polycondensate (polymer) was polyester resin 1 (hereinafter referred to as "resin 1") having an intrinsic viscosity (IV) of 0.68 dl / g.

[0163] <Intrinsic Viscosity> 0.5000±0.0005 g of polyester resin was dissolved in a mixed solvent of phenol:tetrachloroethane = 60:40 (mass ratio), and the intrinsic viscosity (IV) of the polyester resin at 20°C was measured using an automatic viscometer (AVL-6C, manufactured by Sun Electronics Industries Co., Ltd.).

[0164] (Synthesis Examples 2 to 8) - Synthesis of Polyester Resins - Polyester resins 2 to 8 (hereinafter referred to as "resins 2 to 8") were prepared in the same manner as in Synthesis Example 1, except that the types and amounts of monomers in the charged compositions were changed to those shown in Tables 1 and 2.

[0165] <Composition of Polyester Resin> Using an FT-NMR apparatus (DPX400 model, manufactured by Bruker Biospin), a polyester resin was dissolved in deuterated chloroform, and tetramethylsilane was mixed as a standard. The proton NMR spectrum was measured, and the type and content of each unit were calculated from the obtained NMR spectrum.

[0166] Next, the resin composition of each of the obtained polyester resins was measured by NMR as follows: The results of the resin composition are shown in Tables 1 and 2 together with the molar composition of the charged monomers.

[0167]

[0168]

[0169] * The percentages (%) in Tables 1 and 2 were calculated based on [(A1+B1+B4) / (A1+A2+B1+B2+B3+B4)] x 100. * The SP values ​​of the polyester resins in Tables 1 and 2 were calculated based on the above-mentioned Fedors method (the method described in Polym. Eng. Sci. 14(2), 1974, 147-154).

[0170] The following abbreviations are used in Tables 1 and 2: TPA: terephthalic acid IPA: isophthalic acid EG: ethylene glycol NPG: neopentyl glycol (2,2-dimethyl-1,3-propanediol) CHDM: 1,4-cyclohexanedimethanol DEG: diethylene glycol

[0171] (Test Examples 1 to 31) Resins 1 to 8 shown in Tables 1 and 2, and commercially available resin 9 (linear low-density polyethylene (L-LPDE) resin) were used to prepare polyester films shown in Tables 3 to 9 as follows. The polyester films of Test Examples 1 to 15 and Test Examples 18 to 31 were unstretched. Next, the crystallinity, seal strength, and amount of adsorption of organic compounds were measured for each of the obtained polyester films as follows. The results are shown in Tables 3 to 9.

[0172] <Preparation of Polyester Films> Polyester films (unstretched) of Test Examples 1 to 15 and Test Examples 18 to 31 having the layer structures shown in Tables 3 to 9 were prepared by coextrusion at a molding temperature of 280°C using a T-die method. Test Examples 16 and 17 were commercially available linear low-density polyethylene films.

[0173] <Crystallization degree> The crystallization degree was determined by measuring the crystallization enthalpy (ΔHc), recrystallization enthalpy (ΔHc'), and melting enthalpy (ΔHm) of a polyester film in nitrogen using a DSC device (Discovery DSC 2500, manufactured by TA Instruments Japan Inc.) while temperature-modulating the film from 20°C to 300°C at an average temperature-rising rate of 5°C / min, a modulation period of 80 seconds, and a modulation temperature amplitude of 1.0°C.

[0174]

[0175] <Seal Strength> Two polyester films 1 and 2 were prepared from each polyester film of each test example. The first layers (sealing layers) of the two polyester films 1 and 2 were overlapped with each other, and heat-sealed using a heat sealer (TP-701-B HEAT SEAL TESTER, manufactured by Tester Sangyo Co., Ltd.) at a thermocompression (heat sealing) temperature of 110°C, a pressure of 0.2 MPa, and a time of 2 seconds to obtain a heat-sealed product. Next, the obtained heat-sealed product was cut into 15 mm wide strips, and the pressure-bonded portion was pulled at a pulling rate of 100 mm / min using a tensile tester (TECHNO GRAPH TG-5kN, manufactured by MinebeaMitsumi Inc.) to measure the seal strength. The seal strength was also measured in the same manner at a heat sealing temperature of 150°C. The obtained seal strength was evaluated according to the following criteria. [Evaluation Criteria] A: Seal strength of 15 N / 15 mm or more B: Seal strength of less than 15 N / 15 mm

[0176] <Adsorption Test for Organic Compounds> The polyester film obtained in each test example was cut into a 4 cm x 4 cm square test piece, and the test piece was placed on the opposite side (backing surface) of a commercially available patch (Salonpas Ae, manufactured by Hisamitsu Pharmaceutical Co., Ltd.) so that the first layer (sealing layer) of the test piece was in contact with the opposite side. The test piece was then sealed with aluminum foil and stored at 23°C for 2 weeks. After 2 weeks of storage, the test piece was removed and immersed in 5 g of methanol in a beaker, and then subjected to vibrations in an ultrasonic cleaner at 40°C for 10 minutes, thereby extracting the organic compounds adsorbed by the test piece into methanol. Next, the concentration of the organic compounds in the extract (methanol from which the organic compounds were extracted) was measured using a gas chromatograph (GC-2010, manufactured by Shimadzu Corporation), and the adsorption amount of the organic compounds (camphor, menthol, and methyl salicylate) was determined. The SP value of camphor was 9.45 cal / cm ３ , the SP value of menthol is 9.94 cal / cm ３ , the SP value of methyl salicylate is 10.62 cal / cm ３ is.

[0177] The resulting camphor adsorption amount was evaluated according to the following criteria: [Evaluation criteria] A: Camphor adsorption amount was 2 μg / cm ２B: The adsorption amount of camphor is less than 2 μg / cm ２ End

[0178] The resulting amount of menthol adsorbed was evaluated according to the following criteria: [Evaluation criteria] A: The amount of menthol adsorbed was 5 μg / cm ２ B: The amount of menthol adsorbed is less than 5 μg / cm ２ End

[0179] The resulting adsorption amount of methyl salicylate was evaluated according to the following criteria: [Evaluation criteria] A: The adsorption amount of methyl salicylate was 15 μg / cm ２ B: The adsorption amount of methyl salicylate is less than 15 μg / cm ２ End

[0180]

[0181]

[0182]

[0183] *1: Commercially available product (linear low-density polyethylene (L-LPDE) resin)

[0184]

[0185]

[0186]

[0187] In Test Examples 1 to 31 in Tables 3 to 9, the adsorption properties were evaluated using camphor, menthol, and methyl salicylate as representative organic compounds. However, the same level of adsorption results was obtained when limonene, tocopherol acetate, isopropylmethylphenol, ketoprofen, ketoprofen sodium, diclofenac sodium, felbinac, loxoprofen sodium, tulobuterol, rivastigmine, clopumazine hydrochloride, haloperidol, risperidone, paliperidone, blonanserin, perospirone hydrochloride hydrate, lurasidone hydrochloride, olanzapine, quetiapine fumarate, asenapine maleate, clozapine, aripiprazole, or brexpiprazole was used instead of camphor, menthol, and methyl salicylate.

[0188] The results in Tables 3 to 9 show that Test Examples 1 to 5, 20 to 23, and 28 to 29, as well as Test Examples 1 to 12, 18, 22 to 23, and 25 to 26, satisfied all of the following requirements (A) to (C), and therefore exhibited low adsorption to organic compounds in the packaged items and achieved good seal strength even when heat-pressed at a low temperature of 110°C. (A) A polyester film having a first layer and a second layer. (B) The first layer comprises a first polyester resin containing first acid units and first alcohol units, wherein the first acid units comprise 60 mol% to 80 mol% of terephthalic acid units and 20 mol% to 40 mol% of isophthalic acid units relative to the total amount of the first acid units, and the first alcohol units comprise 75 mol% or more of ethylene glycol units relative to the total amount of the first alcohol units. (C) The second layer comprises a second polyester resin containing second acid units including terephthalic acid units and second alcohol units including ethylene glycol units and diethylene glycol units, and the total amount of the terephthalic acid units in the second polyester resin and the ethylene glycol units and diethylene glycol units in the second polyester resin is 95% or more of the total amount of the second acid units and the second alcohol units.

[0189] The polyester films in Test Examples 6 and 7, as well as Test Examples 10 and 11, had a single-layer structure and did not satisfy the requirement (A) above, resulting in a large amount of adsorption of methyl salicylate, a fat-insoluble organic compound.

[0190] Test Examples 8 and 9, as well as Test Examples 18 and 19, were polyester films with a single layer structure, and did not satisfy the above requirement (A), did not satisfy the range of the contents of TPA and IPA in the first polyester resin, and did not satisfy the above requirement (B). As a result, the seal strength in low-temperature thermocompression bonding was reduced.

[0191] Test Example 12 was a polyester film with a single layer structure having a thickness of 50 μm, which did not satisfy the above requirement (A), and the acid units of the first polyester resin were only terephthalic acid units, which did not satisfy the above requirement (B). As a result, the seal strength in low-temperature thermocompression bonding was reduced, and the adsorption amounts of menthol and salicylic acid were increased.

[0192] Test Example 13 was a 30 μm-thick, single-layer polyester film that did not satisfy the above requirement (A), and the first polyester resin contained only terephthalic acid units as acid units, which did not satisfy the above requirement (B). As a result, the seal strength in low-temperature thermocompression bonding was reduced, and the amount of adsorption of salicylic acid, a non-fat-soluble organic compound, was increased.

[0193] Test Example 14 was a 50 μm-thick polyester film with a single layer structure, which did not satisfy the requirement (A) above, and the acid units of the first polyester resin were only terephthalic acid units, and the content of ethylene glycol units did not satisfy the range of the requirement (B) above, so that the seal strength in low-temperature thermocompression bonding was reduced and the adsorption amounts of menthol and salicylic acid were large.

[0194] Test Example 15 was a 30 μm-thick single-layer polyester film that did not satisfy the requirement (A) above, and the acid units of the first polyester resin were only terephthalic acid units, and the content of ethylene glycol units did not satisfy the range of the requirement (B) above, so that the seal strength in low-temperature thermocompression bonding was reduced and the amount of adsorption of salicylic acid, a fat-insoluble organic compound, was increased.

[0195] Test Examples 16 and 17 used a commercially available single-layer linear low-density polyethylene (L-LPDE) resin, which did not satisfy the requirements (A) to (C) above. Therefore, it was not possible to suppress the adsorption of organic compounds, such as camphor, menthol, and methyl salicylate. Furthermore, during heat sealing, the film fused to the heat seal bar, which is the pressure-bonding member of the thermocompression device, making it impossible to perform the seal strength test (seal strength could not be measured).

[0196] Test Examples 24 to 27 did not satisfy the ranges of the contents of TPA and IPA in the first polyester resin, did not satisfy the requirement (B) above, did not satisfy the ranges of the proportions (%) in the second polyester resin, and did not satisfy the requirement (C) above. As a result, the seal strength in low-temperature thermocompression bonding was reduced, and the amount of adsorption of methyl salicylate, a fat-insoluble organic compound, was increased.

[0197] Test Examples 30 and 31 did not satisfy the ranges of the TPA and IPA contents of the first polyester resin, and did not satisfy the requirement (B) above, resulting in a large amount of adsorption of methyl salicylate, a fat-insoluble organic compound.

[0198] The results in Tables 3, 7, and 8 show that the adsorption amount of methyl salicylate, an oil-insoluble organic compound, increased with an increase in units other than TPA, EG, and DEG in the second layer in Test Examples 1 to 4, 20 and 21, and 24 to 27. These results demonstrate that the total amount of TPA, EG, and DEG in the second polyester resin must be 95% or more of the total amount of acid units and alcohol units in the second polyester resin.

[0199] The results in Tables 4 to 6 and 8 show that the seal strength at low temperatures decreased as the IPA units in the first layer (heat seal layer) decreased in Test Examples 8 and 9, 12 to 15, 18 and 19, and 24 to 27. This indicates that the IPA units in the heat seal layer must be 20 mol % or more of the total amount of acid units in the heat seal layer.

[0200] The results in Table 9 show that the adsorption amount of methyl salicylate, a fat-insoluble organic compound, increased with an increase in the IPA units in the first layer (heat seal layer) in Test Examples 30 and 31. This indicates that the IPA units in the first layer must be 40 mol % or more of the total amount of acid units in the first layer.

[0201] The polyester film, laminate, packaging, and product of the present invention have been described based on the above embodiments and examples, but are not limited to the above embodiments and examples, and may include various modifications, changes, and improvements to each disclosed element (including elements described in the claims, specification, and drawings) within the scope of the present invention and based on the basic technical concept of the present invention. Furthermore, various combinations, substitutions, and selections of each disclosed element are possible within the scope of the claims of the present invention.

[0202] The polyester film of the present invention can be suitably used as a packaging sealant film for packaging an article (contents) containing an organic compound such as a medicinal ingredient or a fragrance ingredient.

[0203] 10, 20 Polyester film 11, 21 First layer 12, 22 Second layer 23 Third layer

Claims

1. A polyester film having a first layer and a second layer, wherein the first layer comprises a first polyester resin containing first acid units and first alcohol units, wherein the first acid units comprise 60 mol % to 80 mol % of terephthalic acid units and 20 mol % to 40 mol % of isophthalic acid units relative to the total amount of the first acid units, and the first alcohol units comprise 75 mol % or more of ethylene glycol units relative to the total amount of the first alcohol units, and the second layer comprises a second polyester resin containing second acid units comprising terephthalic acid units and second alcohol units comprising ethylene glycol units and diethylene glycol units, and the total amount of the terephthalic acid units in the second polyester resin and the ethylene glycol units and diethylene glycol units in the second polyester resin is 95% or more relative to the total amount of the second acid units and the second alcohol units.

2. The polyester film according to claim 1, wherein the first alcohol units contain 95 mol % to 99 mol % ethylene glycol units and 1 mol % to 5 mol % diethylene glycol units, based on the total amount of the first alcohol units.

3. The polyester film according to claim 1, wherein the first alcohol units contain, based on the total amount of the first alcohol units, 75 mol % to 90 mol % ethylene glycol units, 1 mol % to 5 mol % diethylene glycol units, and 5 mol % to 20 mol % 2,2-dimethyl-1,3-propanediol units.

4. The polyester film according to claim 1, wherein the second acid units contain 90 mol% or more of terephthalic acid units and 0.5 mol% to 10 mol% of isophthalic acid units, based on the total amount of the second acid units; and the second alcohol units contain 95 mol% to 99 mol% of ethylene glycol units and 1 mol% to 5 mol% of diethylene glycol units, based on the total amount of the second alcohol units.

5. The polyester film according to claim 1, having a thickness of 20 μm to 100 μm.

6. The polyester film of claim 1, wherein the first layer has a thickness of 2 μm to 15 μm.

7. The first polyester resin has a viscosity of 10.70 cal / cm ３ ~15 cal / cm ３ the second polyester resin has a solubility parameter (SP value) of 10.70 cal / cm ３ ~15 cal / cm ３ 2. The polyester film according to claim 1, having an SP value of 8. The polyester film of claim 1, having a crystallinity of 5% to 15%.

9. The polyester film according to claim 1, wherein when two polyester films 1 and 2 are thermocompression bonded together under conditions of 110°C to 150°C, 0.2 MPa, and 2 seconds, the seal strength between said polyester film 1 and said polyester film 2 is 15 N / 15 mm to 50 N / 15 mm.

10. The polyester film according to claim 1, wherein the first layer contains 70% by mass or more of the first polyester resin relative to the mass of the first layer, and the first layer contains 5% by mass to 30% by mass of the second polyester resin relative to the mass of the first layer.

11. The first layer has a viscosity of 10.70 cal / cm ３ ~15 cal / cm ３ 2. The polyester film according to claim 1, having an SP value of 12. The polyester film according to claim 1, wherein the second layer contains 90% by mass or more of the second polyester resin relative to the mass of the second layer, and the second layer contains 5% by mass to 10% by mass of the first polyester resin relative to the mass of the second layer.

13. The second layer has a viscosity of 10.70 cal / cm ３ ~15 cal / cm ３ 2. The polyester film according to claim 1, having an SP value of 14. The polyester film according to claim 1, further comprising a third layer between the first layer and the second layer, the third layer comprising the second polyester resin.

15. The polyester film according to claim 1, which is unstretched.

16. A laminate having a base film and a sealant layer, wherein the sealant layer comprises the polyester film according to any one of claims 1 to 15.

17. A package comprising the polyester film according to any one of claims 1 to 15, wherein at least portions of the polyester film are fused together.

18. A product comprising: a packaged item containing an organic compound; and a polyester film according to any one of claims 1 to 15 that packages the packaged item, wherein at least portions of the polyester film are fused together.

19. The product according to claim 18, wherein the SP value of the polyester film is greater than the SP value of the organic compound contained in the packaged item.

20. The product of claim 18, wherein the organic compound is at least one selected from the group consisting of camphor, menthol, methyl salicylate, limonene, tocopherol acetate, isopropylmethylphenol, ketoprofen, ketoprofen sodium, diclofenac sodium, felbinac, loxoprofen sodium, tulobuterol, rivastigmine, clopumazine hydrochloride, haloperidol, risperidone, paliperidone, blonanserin, perospirone hydrochloride hydrate, lurasidone hydrochloride, olanzapine, quetiapine fumarate, asenapine maleate, clozapine, aripiprazole, and brexpiprazole.

Images