Resin compositions, molded articles, laminated films, packaging containers

Abstract

To provide a resin composition that allows the production of a package having high impact resistance and high welding strength, and a molding, a laminated film, and a package.SOLUTION: Provided is a resin composition in which a resin component includes a polyester-based resin, a polyethylene-based resin, and a compatibilizer having an epoxy group, the polyester-based resin being a polyethylene terephthalate resin modified with a diol having a dialkyl substitution.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to resin compositions, molded articles, laminated films, and packaging containers. [Background technology]

[0002] Patent Document 1 describes a squeeze container in which a multilayer parison is made up of a laminate of an outer layer of olefin resin, an inner layer of substantially amorphous copolymer polyester, and an intermediate layer of adhesive resin, and the bottom heat-sealed portion is substantially amorphous because the inner layers are fused together.

[0003] Patent Document 2 describes a resin composition obtained by blending an amorphous or low-crystalline polyester resin with a glass transition temperature of approximately 50°C or higher with a polyester resin with a glass transition temperature of approximately 40°C or lower. Furthermore, Patent Document 2 states that polyamide resins can also be used instead of polyester resins.

[0004] Patent Document 3 describes a tube container in which at least the innermost layer of the body is made of an amorphous or low-crystalline polyester resin with a glass transition temperature of about 50°C or higher and an intrinsic viscosity of about 0.7 or higher, and the top part is made of a polyester resin with a glass transition temperature of about 40°C or lower. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2002-96847 [Patent Document 2] Japanese Patent Application Publication No. 5-156144 [Patent Document 3] Japanese Patent Application Publication No. 4-352646 [Overview of the project] [Problems that the invention aims to solve]

[0006] When the innermost layer or all layers of a container are made of polyester, it has the disadvantage of poor impact resistance and drop strength under low-temperature conditions. In particular, the strength of the top and the welding strength between the top and the body are low. Containers that use polyamide resin instead of polyester resin have the disadvantage of swelling due to water absorption when the contents are liquids containing moisture, leading to a decrease in strength.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a resin composition, molded article, laminated film, and packaging container that can be manufactured to produce a packaging container with excellent impact resistance and welding strength. [Means for solving the problem]

[0008] The present invention includes the following embodiments. A first aspect of the present invention is a resin composition comprising a polyester resin, a polyethylene resin, and a compatibilizer having an epoxy group, wherein the polyester resin is a polyethylene terephthalate resin modified with a diol having a dialkyl substitution.

[0009] A second aspect of the present invention is that, in the first aspect, the diol having a dialkyl substitution is neopentyl glycol or 2-butyl-2-ethyl-1,3-propanediol. A third aspect of the present invention is that, in the first or second aspect, the compatibilizer having the epoxy group is ethylene-glycidyl methacrylate.

[0010] A fourth aspect of the present invention is a molded article characterized by being molded from a resin composition according to any one of the first to third aspects. A fifth aspect of the present invention is a laminated film characterized in that the innermost sealant is formed from a resin composition according to any one of the first to third aspects. A sixth aspect of the present invention is a packaging container characterized in that at least one of the opening or the bottom is formed from a molded article of the fourth aspect. A seventh aspect of the present invention is a packaging container characterized by having a body formed from a laminated film of the fifth aspect.

[0011] An eighth aspect of the present invention is a resin composition comprising a polyester resin and a polyethylene resin, wherein the polyester resin constitutes a sea portion and the polyethylene resin constitutes an island portion, forming a sea-island structure, and the polyester resin is a polyethylene terephthalate resin modified with a diol having a dialkyl substitution.

[0012] The ninth aspect of the present invention is a resin composition according to the eighth aspect, wherein a thin section obtained by cutting a cross-section of the resin composition with a microtome is stained with ruthenium tetroxide, observed at 20,000x magnification using a field emission scanning electron microscope to acquire an image, and when the island portion of the sea-island structure is extracted as a circular or elliptical shape using image analysis software, the area ratio of the island portion to the entire sea-island structure is 5 to 40%. A tenth aspect of the present invention is a resin composition of the eighth or ninth aspect wherein the island portions constituting the polyethylene resin are such that the average particle size of the island portions when the island portions of a sea-island structure are extracted as circular or elliptical shapes using image analysis software is 0.1 to 2.0 μm.

[0013] An eleventh aspect of the present invention is a resin composition according to any one of the eighth to tenth aspects, which further contains a compatibilizer and / or has a compatibilizer added to the resin. A twelfth aspect of the present invention is a resin composition according to the eleventh aspect, in which the compatibilizer contains a copolymer chain of (meth)acrylic acid and / or (meth)acrylic acid ester and ethylene. A thirteenth aspect of the present invention is a resin composition according to the twelfth aspect, wherein the copolymer chain is an ethylene-glycidyl (meth)acrylate copolymer chain.

[0014] A fourteenth aspect of the present invention is a molded article characterized by being molded from a resin composition according to any one of the eighth to thirteenth aspects. The 15th aspect of the present invention is a laminated film characterized in that the innermost sealant is formed from the resin composition of any one of the 8th to 13th aspects. The 16th aspect of the present invention is a packaging container characterized in that at least one of the mouth part or the bottom part is formed from the molded product of the 14th aspect. The 17th aspect of the present invention is a packaging container characterized by having a body part formed from the laminated film of the 15th aspect.

Effects of the Invention

[0015] According to the present invention, it is possible to provide a resin composition, a molded product, a laminated film, and a packaging container capable of manufacturing a packaging container excellent in impact resistance and welding strength.

Brief Description of the Drawings

[0016] [Figure 1] It is a schematic diagram illustrating the packaging container of the first embodiment. [Figure 2] It is a schematic diagram illustrating the packaging container of the second embodiment. [Figure 3] It is a schematic diagram illustrating the packaging container of the third embodiment. [Figure 4] It is an electron micrograph showing an example of the sea-island structure.

Modes for Carrying Out the Invention

[0017] Hereinafter, the present invention will be described based on preferred embodiments. In this specification, the main component is the component having the largest ratio. The ratio of the main component is preferably 50% by weight or more of the whole, and may be 70% by weight or more, 80% by weight or more, 90% by weight or more.

[0018] The resin composition of the embodiment contains a polyester resin and a polyethylene resin. The polyester resin constitutes the sea portion and the polyethylene resin constitutes the island portion, forming a sea-island structure. The polyester resin is a polyethylene terephthalate resin modified with a diol having a dialkyl substitution. This resin composition may further contain a compatibilizer, or / or the compatibilizer may be added to the resin.

[0019] In this specification, "or / and" means, like "and / or," that at least one of the first option listed before the phrase and the second option listed after the phrase is selected. In other words, a phrase containing such words encompasses three cases: (1) the first option is selected and the second option is not selected; (2) the first option is not selected and the second option is selected; and (3) both the first and second options are selected.

[0020] The resin composition of the embodiment contains a polyester resin, a polyethylene resin, and a compatibilizer having an epoxy group as resin components. The polyester resin contained in this resin composition is a polyethylene terephthalate resin modified with a diol having a dialkyl substitution.

[0021] The polyester resin used in the resin composition of the embodiment is a linear polyester resin obtained by condensation polymerization of a polyester raw material mainly composed of a dicarboxylic acid and a diol. The dicarboxylic acid component is mainly terephthalic acid. The diol component is mainly ethylene glycol and further contains a diol having a dialkyl substitution.

[0022] In the resin composition of the embodiment, examples of carboxylic acid components of the polyester resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalene-1,4-dicarboxylic acid, and naphthalene-2,6-dicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, and tricarboxylic acids such as trimellitic acid.

[0023] In the resin composition of the embodiment, examples of diol components of the polyester resin include linear diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexamethylenediol; cyclic diols such as cyclopentanedimethanol and cyclohexanedimethanol; and branched diols such as 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-butyl-2-methyl-1,3-propanediol, and 2-butyl-2-ethyl-1,3-propanediol.

[0024] Unlike linear diols, which have only a main chain containing two hydroxyl groups, branched diols have one or more alkyl groups as side chains branching from the main chain. Diols with dialkyl substitution have two alkyl groups in the side chains of branched diols. By using these branched diols as part of the diol component to modify polyethylene terephthalate resin, the crystallinity of the polyester resin can be reduced, making it amorphous or low-crystallinity. This can improve the impact resistance and increase the weld strength of the polyester resin.

[0025] Dialkyl-substituted diols have the general formula HO(CH2) n In a linear diol with n carbon atoms represented by OH, two of the total 2n hydrogen atoms are substituted with alkyl groups. The number of carbon atoms in the main chain, n, is, for example, within the range of 1 to 6. The positions a and b of the carbon atoms substituted with alkyl groups can each be independently selected from within the range of 1 to n.

[0026] When the position a or b of the dialkyl substitution of the diol is equal to 1 or n, the hydroxyl group becomes a secondary alcohol or a tertiary alcohol, and in the synthesis of the polyester, there is a possibility that the condensation reaction with the carboxylic acid component may not proceed easily. Therefore, it is preferable that the positions a and b of the alkyl group substitution are greater than 1 and less than n.

[0027] When the positions a and b of the alkyl group substitution are equal, the general formula of the dialkyl-substituted diol is HO(CH2) a-1 C(R 1 )(R 2 )(CH2) n-a OH. R 1 and R 2 are each an alkyl group having, for example, 1 to 6 carbon atoms. Examples of the alkyl group include a methyl group having 1 carbon atom, an ethyl group having 2 carbon atoms, a propyl group or an isopropyl group having 3 carbon atoms, a butyl group having 4 carbon atoms, an isobutyl group, etc., a pentyl group having 5 carbon atoms, an isopentyl group, etc.

[0028] The number of carbon atoms n in the main chain of the dialkyl-substituted diol is more preferably 3 to 4, and the number of carbon atoms of the alkyl groups R 1 and R 2 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, that is, 2,2-dimethyl-1,3-propanediol, R 1 and R 2 are methyl groups. In 2-butyl-2-ethyl-1,3-propanediol, R 1 and R 2 are a butyl group and an ethyl group, respectively.

[0029] In the resin composition of the embodiment, the polyester resin may contain, as a main component, a polyethylene terephthalate resin modified with a diol having a dialkyl substitution, and may further contain another polyester resin or a thermoplastic resin. [[ID=​​In the resin composition of the embodiment, the intrinsic viscosity (IV) of the polyester resin is preferably 0.60 to 0.85 dl / g. The intrinsic viscosity in the present invention is measured at 30°C in a phenol / 1,1,2,2-tetrachloroethane (mass ratio 1 / 1) mixed solvent in accordance with JIS K 7367-5. This makes it easier to achieve both non-adsorbent properties and moldability of the resin.

[0031] In the resin composition of the embodiment, the polyethylene resin can improve the impact resistance of the resin composition and increase the welding strength. The polyethylene resin may be a single copolymer of polyethylene, or a copolymer of ethylene and a monomer other than ethylene. Examples of monomers other than ethylene include propylene, olefins with 4 carbon atoms (such as 1-butene), olefins with 6 carbon atoms (such as 1-hexene), and olefins with 8 carbon atoms (such as 1-octene). The polyethylene resin may also be a polymer obtained by polymerizing only hydrocarbon monomers that do not contain polar monomers such as vinyl acetate, such as ethylene-vinyl acetate copolymer (EVA). Specific examples of polyethylene resins are not particularly limited, but include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE).

[0032] In the resin composition of the embodiment, the compatibilizer has compatibility with polyethylene resins and has an epoxy group (>O) as a functional group that can react with hydroxyl groups (-OH) or carboxyl groups (-COOH) which are terminal groups of polyester resins. Examples of such compatibilizers include copolymers containing at least an olefin such as ethylene and a monomer having an epoxy group (epoxy group-containing monomer).

[0033] Examples of epoxy group-containing monomers include unsaturated ester monomers having epoxy groups such as glycidyl acrylate and glycidyl methacrylate; unsaturated ether monomers having epoxy groups such as vinyl glycidyl ether and allyl glycidyl ether; and epoxy olefins such as 3,4-epoxy-1-butene, 4,5-epoxy-1-pentene, and 5,6-epoxyhexene.

[0034] The copolymer that serves as the compatibilizer may be further copolymerized with monomers having functional groups other than epoxy groups. Examples of such monomers include acrylic acid esters such as ethyl acrylate and butyl acrylate, and unsaturated carboxylic acids such as acrylic acid. The compatibilizer is preferably a copolymer mainly composed of ethylene, copolymerized with at least glycidyl methacrylate (GMA) as the epoxy group-containing monomer. An example of such a copolymer is an ethylene-glycidyl methacrylate copolymer. The content of the epoxy group-containing monomer in the copolymer having epoxy groups is not particularly limited, but for example, 2 to 30% by weight is preferred, and 5 to 20% by weight is more preferred.

[0035] The compatibilizer may contain a copolymer chain of (meth)acrylic acid and / or (meth)acrylic acid ester and ethylene. The copolymer chain may also be an ethylene-glycidyl (meth)acrylate copolymer chain. These copolymer chains may be the main chain and / or side chains of the copolymer. Here, (meth)acrylic acid means acrylic acid and / or methacrylic acid. Also, (meth)acrylate means acrylate and / or methacrylate.

[0036] The resin composition of the embodiment may contain a compatibilizer, and / or the compatibilizer may be attached to the resin. Here, the attachment of the compatibilizer to the resin means, for example, that the functional groups contained in the compatibilizer are covalently bonded to the functional groups contained in the resin, or that the compatibilizer is attached to the resin by hydrogen bonding, hydrophobic interactions, π-π interactions, etc.

[0037] The resin composition of the embodiment preferably mainly comprises a polyester resin, and more preferably a polyethylene terephthalate resin modified with the diol having the dialkyl substitution. The blending ratio of the polyester resin, polyethylene resin, and compatibilizer having an epoxy group is such that, with a total of 100 parts by weight of the resin composition or resin components of the embodiment, the ratio is 50 to 90 parts by weight of polyester resin, 3 to 35 parts by weight of polyethylene resin, and 1 to 20 parts by weight of compatibilizer.

[0038] The proportion of polyester resin may be, for example, 60 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, etc. The proportion of polyethylene resin may be, for example, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, etc. The proportion of compatibilizer may be, for example, 3 parts by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, etc.

[0039] The resin composition of the embodiment may contain appropriate additives in addition to the resin component, as long as the purpose of the resin composition is not impaired. Examples of additives include at least one of antioxidants, lubricants, antiblocking agents, flame retardants, ultraviolet absorbers, light stabilizers, antistatic agents, and colorants. Each of these additives can be independently selected whether or not to be included in the resin composition.

[0040] The resin composition of the embodiment may have a polyester resin and a polyethylene resin forming a sea-island structure. This sea-island structure may be one in which the polyester resin constitutes the sea portion and the polyethylene resin constitutes the island portion. The resin composition of the embodiment can form a sea-island structure by the mismatch of the polyester resin and the polyethylene resin via a compatibilizer or the like.

[0041] The method for observing the sea-island structure is not particularly limited, but a thin section obtained by cutting a cross-section of the resin composition with a microtome may be stained with ruthenium tetroxide, observed at 20,000x magnification using a field emission scanning electron microscope to acquire an image, and the island portion of the sea-island structure may be extracted as a circle or ellipse using image analysis software.

[0042] When the island portions of a sea-island structure are extracted as circular or elliptical shapes using image analysis software, the area ratio occupied by the island portions to the entire sea-island structure is preferably 5-40%, and more preferably 10-30%. These island portions are made of polyethylene resin. Here, "extracting the island portions as circular or elliptical shapes" means that even if the shape of the island portions in the image is neither circular nor elliptical, the area is calculated by converting them to a circular or elliptical shape. For example, each island portion can be extracted as a circular or elliptical shape, and the area ratio can be calculated by summing the areas of the circles or ellipses. Also, "the entire sea-island structure" means the entire "part of the sea-island structure from which the image was acquired." The sum of the area ratio occupied by the sea portion and the area ratio occupied by the island portions of the sea-island structure is 100%. In other words, in the above case, the area ratio occupied by the sea portion is 60-95% or 70-90%.

[0043] When island portions of a sea-island structure are extracted as circular or elliptical shapes using image analysis software, the average particle size of the island portions is preferably 0.1 to 2.0 μm. These island portions are composed of polyethylene resin. Here, "extracting island portions as circular or elliptical shapes" means that even if the shape of the island portions in the image is neither circular nor elliptical, it is converted to a circular or elliptical shape and the diameter is calculated. For example, each island portion can be extracted as a circular or elliptical shape, the diameter of the circle and the average of the major and minor axes of the ellipse can be determined, and their average value can be calculated.

[0044] The resin composition of the embodiment can be used to mold a molded article. The molding method of the molded article is not particularly limited and includes injection molding, extrusion molding, blow molding, in-mold molding, etc. The molded article may be a resin molded article using the resin composition of the embodiment alone, or it may be a resin molded article in which a resin molded part made of the resin composition of the embodiment is laminated with another resin. The molded article can also be made by molding the resin composition of the embodiment on top of a molded article formed from another resin.

[0045] Laminated films can also be formed using the resin composition of the embodiment. Because the resin composition of the embodiment has excellent impact resistance and welding strength, it is also suitable as a sealant used for the innermost layer of a laminated film.

[0046] The laminated film may have a substrate as a resin layer other than the sealant. Preferably, the substrate is a resin film with excellent mechanical properties such as heat resistance and strength, as well as printability. Specifically, examples include polyethylene terephthalate film, nylon film, polypropylene film, and polyolefin film. The resin film of the substrate may also be a stretched film. The thickness of the substrate in the laminated film is not particularly limited, but may be, for example, 10 to 50 μm.

[0047] A sheet-like laminate thicker than a laminated film may be used in the manufacture of packaging containers. The laminate may be flexible and pliable. The thickness of the laminate is not particularly limited, but may be 1000 μm or less, or about 1 to 3 mm. One or more types of substrates may be laminated in two or more layers.

[0048] A layer of anchoring agent or adhesive may be interposed between each layer forming the laminate, such as between the sealant and the substrate, as needed. When the sealant is formed by the extrusion lamination method, an anchoring agent layer is formed in contact with the sealant. If the sealant is mainly composed of polyester resin and the substrate is a polyester film such as polyethylene terephthalate, an anchoring agent layer may not be used. When a sealant that has been manufactured as a molded film in advance is bonded to the substrate by the dry lamination method, an adhesive layer is formed in contact with the inside of the sealant. Furthermore, when using the co-extrusion method, an adhesive resin such as acid-modified polyolefin may be used between the sealant and the substrate.

[0049] As the anchoring agent constituting the aforementioned anchoring agent layer, commonly used anchoring agents in the extrusion lamination method, such as polyurethane-based, polyether-based, and alkyl titanate (organotitanium compound)-based anchoring agents, can be used. As the adhesive constituting the aforementioned adhesive layer, commonly used adhesives in the dry lamination method, such as polyurethane-based and polyether-based adhesives, can be used.

[0050] The substrate of the laminate may have two or more resin layers, or it may have an inorganic material layer other than a resin layer. Examples of inorganic material layers include metals such as aluminum, and oxides such as alumina and silica. Depending on the material, the inorganic material layer can be formed as a metal foil, a vapor-deposited film, a sputtered film, or the like.

[0051] The packaging container of the first embodiment is a cylindrical container 10, as shown in Figure 1, in which a mouth portion 12 and a bottom portion 13 are joined to both ends of a cylindrical body portion 11. At least one of the mouth portion 12 or the bottom portion 13 may be molded from the resin composition of the embodiment. The body portion 11 may be formed from a laminated film having the resin composition of the embodiment as a sealant. The body portion 11 may be formed in a cylindrical shape.

[0052] The packaging container of the second embodiment is a tube container 20, as shown in Figure 2, in which a mouth portion 22 is joined to one end of a tubular body portion 21, and the other end of the body portion 21 is sealed by a sealing portion 23. The mouth portion 22 may be molded from the resin composition of the embodiment. The body portion 21 may be formed from a laminated film having the resin composition of the embodiment as a sealant. The sealing portion 23 is formed by crushing the other end of the body portion 21 and joining the inner surfaces together.

[0053] The packaging container of the third embodiment may be a pouch container 30, as shown in Figure 3, in which a mouth portion 32 is joined to at least one location on the periphery of a bag-shaped body portion 31 formed from a packaging film. The mouth portion 32 may be molded from the resin composition of the embodiment. The body portion 31 may be formed from a laminated film having the resin composition of the embodiment as a sealant. The form of the pouch-shaped body portion 31 is not particularly limited, but examples include three-sided bags, four-sided bags, gusseted bags, gusseted bags, standing pouches, etc. The body portion 31 may be a large packaging bag, such as an inner bag for a bag-in-box.

[0054] If the pouch container 30 is opened by cutting the body 31 or a part thereof, the mouth portion 32 of the pouch container 30 may be omitted. In this case, although not shown in particular, the inner surfaces of the packaging film may be brought together to form a seal around the entire circumference of the body 31. To facilitate opening the body 31, notches or other cuts may be made at the end of the opening, or an easy-open line such as a half-cut groove may be formed along the opening. The opening portion of the body 31 may be formed in a tapered shape that protrudes from the portion containing the contents.

[0055] The packaging container of this embodiment contains a polyester resin in at least one of the molded article joined to the body or the sealant of the body, thus exhibiting excellent non-adsorption and barrier properties for low molecular weight components. Furthermore, since at least one of the molded article joined to the body or the sealant of the body is formed from the resin composition of this embodiment, it also exhibits excellent impact resistance and welding strength. For example, even when the packaging container is dropped or hit, damage and deterioration of the joints can be suppressed, and durability such as drop strength can be improved.

[0056] Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. [Examples]

[0057] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples.

[0058] (Resin composition) The raw resins were blended in the proportions shown in Tables 1 and 2, and then melt-kneaded to produce resin composition pellets. Subsequently, the pellets were molded to a thickness of 0.5 mm using a hot press to obtain single-layer press sheet samples.

[0059] In Tables 1 and 2, when showing the resin composition, the blending ratio in parts by weight is indicated to the right of the raw material resin symbol. For example, "A-1 80" indicates that resin A-1 was used at a ratio of 80 parts by weight. The raw material resins shown in Tables 1 and 2 are as follows:

[0060] (A) Polyester resin "A-1": Amorphous neopentyl glycol (NPG) modified polyethylene terephthalate (PET) resin (density ρ = 1.29 g / cm³) 3 (No melting point Tm, IV = 0.83) "A-2": Amorphous 2-butyl-2-ethyl-1,3-propanediol (BEPD) modified polyethylene terephthalate (PET) resin (no melting point Tm, IV=0.75)

[0061] (B) Polyethylene resin "B-1": Metallocene catalyzed polymerization C6-LLDPE (density ρ=0.915g / cm 3 Melting point Tm = 121°C, MFR = 1g / 10min (190°C, 2.16kgf)

[0062] (C) Compatibilizer "C-1": Ethylene-glycidyl methacrylate (EGMA) copolymer (melting point Tm = 105°C, MFR = 3g / 10min, GMA 6% by weight)

[0063] The following tests were conducted using samples of the prepared pellets or press sheets.

[0064] (1) Melt Flow Rate (MFR) The melt flow rate (MFR) was measured using pellets of the resin composition at a test temperature of 260°C or 280°C and a nominal load of 2.16 kg (g / 10 min).

[0065] (2) Bending test Using samples prepared by cutting press sheets to a width of 15 mm, a bending test was conducted using an MIT bending resistance tester (manufactured by Tester Industries Co., Ltd.) at 1.5 kgf and an angle of 135°, and the number of bending cycles until breakage was measured.

[0066] (3) Seal strength In accordance with JIS Z 1526, two samples prepared by cutting press sheets to a width of 15 mm were heat-sealed facing each other, and the seal strength (15 mm / N) of the samples was measured at a tensile speed of 300 mm / min and a width of 15 mm. The heat-sealing conditions were the temperatures shown in Tables 1 and 2, centered around 180°C, with a pressure of 0.2 MPa and a heating time of 1 second.

[0067] The results are shown in Tables 1 and 2.

[0068] [Table 1]

[0069] [Table 2]

[0070] Samples of molded articles formed from the resin compositions of Examples 1 to 6 were found to have excellent impact resistance and weld strength. As crosslinking of the polyester resin by the epoxy groups of the compatibilizer progressed, viscosity tended to increase and MFR tended to decrease. The samples in Comparative Examples 1 and 2 had a low number of folds in the bending test and exhibited low impact resistance.

[0071] (Evaluation of non-adsorption properties) Press sheets with a thickness of 0.5 mm, molded using the resin compositions of Examples 1 and 6 shown in Table 1, were cut to a width of 7 mm and a length of 30 mm to prepare samples for evaluating non-adsorption properties. Similarly, samples for evaluating non-adsorption properties were molded using the following polyethylene resins. Comparative Example 3 was the case using polyethylene resin B-2, and Comparative Example 4 was the case using polyethylene resin B-3.

[0072] (B) Polyethylene resin "B-2": Metallocene catalyzed polymerization LLDPE (density ρ=0.924g / cm 3 Melting point Tm = 120°C, MFR = 2.2g / 10min (190°C, 2.16kgf) "B-3": HDPE (density ρ=0.949g / cm 3 Melting point Tm = 130°C, MFR = 1.1g / 10min (190°C, 2.16kgf)

[0073] Using a sample for evaluating non-adsorption, the non-adsorption properties were evaluated using the following method.

[0074] (4) Method for measuring the remaining amount of tocopherol acetate Along with a sample for evaluating non-adsorption, 3 ml of commercially available lotion containing α-tocopherol acetate (vitamin E acetate) as the active ingredient was placed in a 3 ml brown bottle, capped, and sealed. The sealed brown bottle was stored at 40°C and 90% RH for 2 months, then opened, and the remaining amount of α-tocopherol acetate in the lotion was quantified by high-performance liquid chromatography. Based on this remaining amount, the remaining percentage of tocopherol acetate was calculated.

[0075] The results of the measurement of the remaining tocopherol acetate are as follows: Example 1: 97.2% Example 6: 97.3% Comparative Example 3: 59.6% Comparative Example 4: 61.0%

[0076] When the resin compositions of Examples 1 and 6 were used, the remaining tocopherol acetate was high. Although the measurement results are not shown, it is presumed that when the resin compositions of Examples 2 to 5 were used, a high remaining tocopherol acetate rate would be obtained, similar to that of Examples 1 and 6.

[0077] (Observation of sea-island structure) Thin sections obtained by microtome cutting cross-sections of molded product samples formed from the resin compositions of Examples 1 to 6 were stained with ruthenium tetroxide, observed at 20,000x magnification using a field emission scanning electron microscope, and images were acquired. The island portions of the sea-island structure were extracted as circles or ellipses using image analysis software. The area ratio of the island portions to the entire sea-island structure and the average particle size of the island portions were determined and are shown in Table 3. The average particle size was calculated by taking the diameter of the extracted circles and the average of the major and minor axes of the extracted ellipses, and using these average values ​​as the average particle size.

[0078] [Table 3]

[0079] Figure 4 also shows an example of an electron microscope image illustrating a sea-island structure. However, the dimensions of Figure 4 may have been altered from the original image, and the magnification may not necessarily be 20,000x. [Explanation of Symbols]

[0080] 10...Cylindrical container, 11...Body of cylindrical container, 12...Mouth of cylindrical container, 13...Bottom of cylindrical container, 20...Tube container, 21...Body of tube container, 22...Mouth of tube container, 23...Sealing part of tube container, 30...Pouch container, 31...Body of pouch container, 32...Mouth of pouch container.

Claims

1. The resin composition comprises a polyester resin, a polyethylene resin, and a compatibilizer having an epoxy group. The aforementioned polyester resin is a polyethylene terephthalate resin modified with neopentyl glycol. The resin composition is characterized in that the island portions composed of the polyethylene resin have an average particle size of 0.1 to 0.65 μm when the island portions of a sea-island structure are extracted as circular or elliptical shapes using image analysis software.

2. The resin composition according to claim 1, characterized in that the compatibilizer having the epoxy group is ethylene-glycidyl methacrylate.

3. A molded article characterized by being molded from the resin composition described in claim 1 or 2.

4. A laminated film characterized in that the innermost sealant is formed from the resin composition described in claim 1 or 2.

5. A packaging container characterized in that at least one of the opening or the bottom is formed from the molded article described in claim 3.

6. A packaging container characterized by having a body portion formed from the laminated film described in claim 4.

7. It contains polyester resin and polyethylene resin. The aforementioned polyester resin constitutes the sea portion, and the aforementioned polyethylene resin constitutes the island portion, forming a sea-island structure. The aforementioned polyester resin is a polyethylene terephthalate resin modified with neopentyl glycol. The resin composition is characterized in that the island portions composed of the polyethylene resin have an average particle size of 0.1 to 0.65 μm when the island portions of a sea-island structure are extracted as circular or elliptical shapes using image analysis software.

8. The resin composition according to claim 7, wherein when a thin section obtained by cutting a cross-section of the resin composition with a microtome is stained with ruthenium tetroxide, observed at 20,000x magnification using a field emission scanning electron microscope to acquire an image, and the island portion of the sea-island structure is extracted as a circle or ellipse using image analysis software, the area ratio of the island portion to the entire sea-island structure is 5 to 40%.

9. Furthermore, the resin composition according to claim 7 or 8, wherein it contains a compatibilizer and / or the compatibilizer is added to the resin.

10. The resin composition according to claim 9, wherein the compatibilizer contains a copolymer chain of (meth)acrylic acid and / or (meth)acrylic acid ester and ethylene.

11. The resin composition according to claim 10, wherein the copolymer chain is an ethylene-glycidyl (meth)acrylate copolymer chain.

12. A molded article characterized by being molded from the resin composition described in claim 7 or 8.

13. A laminated film characterized in that the innermost sealant is formed from the resin composition described in claim 7 or 8.

14. A packaging container characterized in that at least one of the opening or the bottom is formed from the molded article described in claim 12.

15. A packaging container characterized by having a body portion formed from the laminated film described in claim 13.

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