JP2023004922A - packaging container - Google Patents

Abstract

To provide a packaging container exhibiting high shock resistance and deposition strength.SOLUTION: This packaging container comprises: a molded article such as a mouth 12 or a bottom 13 molded by a resin composition containing a first polyester resin, a polyethylene resin, and a compatibility accelerator having an epoxy group; and a trunk 11 joined to the molded article. The trunk 11 has a layer containing a second polyester resin on the surface joined to the molded article. The first polyester resin contained in the resin composition of the molded article is a polyethylene terephthalate resin modified by diol having a dialkyl substituent.SELECTED DRAWING: Figure 1

Description

The present invention relates to packaging containers.

In Patent Document 1, a multi-layer parison is composed of a laminate of an outer layer of an olefin resin, an inner layer of a substantially amorphous copolyester, and an intermediate layer of an adhesive resin, and the bottom heat-sealed portion is formed between the inner layers. is fused to be substantially amorphous.

Patent Document 2 describes a resin composition obtained by blending an amorphous or low-crystalline polyester resin having a glass transition temperature of about 50°C or higher and a polyester resin having a glass transition temperature of about 40°C or lower. ing. Moreover, in Patent Document 2, polyamide resin can be used instead of polyester resin.

In Patent Document 3, at least the innermost layer of the body uses an amorphous or low-crystalline polyester resin having a glass transition temperature of about 50 ° C. or more and an intrinsic viscosity of about 0.7 or more, and the head is made of glass A tube container using a polyester resin having a transition temperature of about 40° C. or less is described.

JP-A-2002-96847 JP-A-5-156144 JP-A-4-352646

When the innermost layer or all layers of the container are formed of polyester, there is a drawback that the impact resistance and drop strength under low temperature conditions are inferior. In particular, the strength of the head and the welding strength between the head and body are low. A container using a polyamide resin instead of a polyester resin has the drawback that when the content is a liquid containing water, the container swells due to water absorption, resulting in a decrease in strength.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a packaging container that is excellent in impact resistance and welding strength.

The present invention includes the following aspects.
A first aspect of the present invention is a molded article molded from a resin composition containing a first polyester resin, a polyethylene resin, and a compatibilizer having an epoxy group; The body has a layer containing a second polyester resin on the surface that is bonded to the molded product, and the second polyester resin is the first The resin may be the same resin as the polyester resin or may be a different resin, and the first polyester resin contained in the resin composition of the molded product is a polyethylene terephthalate resin modified with a diol having dialkyl substitution. A packaging container characterized by

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

According to a fourth aspect of the present invention, in any one of the first to third aspects, at least one of the mouth portion and the bottom portion is formed from the molded article.
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the trunk portion has a tubular shape having a mouth portion and a bottom portion at both ends.
According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the body portion has a tubular shape with one end joined to a mouth portion and the other end crushed and sealed.
According to a seventh aspect of the present invention, in any one of the first to fourth aspects, the body portion is formed from a pouch.

An eighth aspect of the present invention has a molded product containing a first polyester-based resin and a polyethylene-based resin, and a body portion joined to the molded product, wherein the body portion is the molded product It has a layer containing a second polyester resin on the surface to be joined, and the second polyester resin may be the same resin as the first polyester resin, or may be a different resin, and the molding The product has a resin composition that forms a sea-island structure in which the first polyester-based resin constitutes the sea portion and the polyethylene-based resin constitutes the island portion, and the first polyester-based resin has dialkyl substitution. The packaging container is a diol-modified polyethylene terephthalate resin.

In the ninth aspect of the present invention, a thin piece obtained by cutting a cross section of the molded article with a microtome is stained with ruthenium tetroxide, and an image is obtained by observing at 20,000 times using a field emission scanning electron microscope. and extracting the islands of the sea-island structure as circles or ellipses using image analysis software, the area ratio of the islands to the entire sea-island structure is 5 to 40%. is a container.
In a tenth aspect of the present invention, the islands composed of the polyethylene-based resin have an average particle diameter of 0 when the islands having a sea-island structure are extracted as circular or elliptical shapes using image analysis software. .1 to 2.0 μm, the packaging container according to the eighth or ninth aspect.

An eleventh aspect of the present invention is the packaging container according to any one of the eighth to tenth aspects, wherein the molded article further contains a compatibilizer and/or the compatibilizer is added to the resin. .
A twelfth aspect of the present invention is the packaging container according to the eleventh aspect, wherein the compatibilizer contains a copolymer chain of (meth)acrylic acid or/and (meth)acrylic acid ester and ethylene.
A thirteenth aspect of the present invention is the packaging container according to the twelfth aspect, wherein the copolymer chain is an ethylene-glycidyl (meth)acrylate copolymer chain.

ADVANTAGE OF THE INVENTION According to this invention, the packaging container excellent in impact resistance and welding strength can be provided.

It is a schematic diagram which illustrates the packaging container of a 1st embodiment. It is the schematic which illustrates the packaging container of 2nd Embodiment. It is the schematic which illustrates the packaging container of 3rd Embodiment. 1 is an electron micrograph showing an example of a sea-island structure.

The present invention will be described below based on preferred embodiments. As used herein, the major component is the component with the greatest proportion. The proportion 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, or 90% by weight or more.

A packaging container of an embodiment has a molded product containing a first polyester resin and a polyethylene resin, and a body portion joined to the molded product. The trunk portion has a layer containing a second polyester-based resin on the surface to be joined to the molded product. The second polyester-based resin may be the same resin as the first polyester-based resin, or may be a different resin. The molded product has a resin composition that forms a sea-island structure in which the first polyester-based resin constitutes the sea portion and the polyethylene-based resin constitutes the island portion. The first polyester-based resin is a diol-modified polyethylene terephthalate resin having dialkyl substitution. The molded article may further contain a compatibilizer and/or the compatibilizer may be added to the resin.

In this specification, "or/and" is, like "and/or", at least one of the first option described before the word and the second option described after the word is selected. That is, the wording including the phrase is (1) when the first option is selected and the second option is not selected, (2) when the first option is not selected and the second option is selected (3) when both the first option and the second option are selected (1) to (3);

A packaging container of an embodiment includes a molded article molded from a resin composition containing a first polyester resin, a polyethylene resin, and a compatibilizer having an epoxy group, and is bonded to the molded article. and a torso. The body has a layer containing a second polyester-based resin on the surface to be joined to the molded article. The first polyester resin contained in the resin composition of the molded article is a diol-modified polyethylene terephthalate resin having dialkyl substitution.

The first polyester resin used in the resin composition of the molded product is a linear polyester resin obtained by condensation polymerization of polyester raw materials containing dicarboxylic acid and diol as main components. The dicarboxylic acid component is mainly composed of terephthalic acid. Also, the diol component is based on ethylene glycol and further contains a diol having dialkyl substitution.

In the resin composition of the molded article, the carboxylic acid component of the first polyester-based resin includes aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalene-1,4-dicarboxylic acid, and naphthalene-2,6-dicarboxylic acid. , adipic acid, aliphatic dicarboxylic acids such as sebacic acid, and tricarboxylic acids such as trimellitic acid.

In the resin composition of the molded article, the diol component of the first polyester resin includes ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexamethylene. Linear diols such as diols; cyclic diols such as cyclopentanedimethanol and cyclohexanedimethanol; neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2,2-dipropyl-1,3-propanediol , 2-propyl-2-methyl-1,3-propanediol, 2-propyl-2-ethyl-1,3-propanediol, 2-isopropyl-2-methyl-1,3-propanediol, 2-isopropyl- Branched diols such as 2-ethyl-1,3-propanediol, 2-butyl-2-methyl-1,3-propanediol and 2-butyl-2-ethyl-1,3-propanediol are included.

Branched diols have one or more alkyl groups as side chains branching from the main chain, whereas linear diols have only a main chain containing two hydroxyl groups. Diols with dialkyl substitution have two alkyl groups on the side chains of the branched diol. By using these branched diols as part of the diol component to modify the polyethylene terephthalate resin, the crystallinity of the first polyester resin can be lowered to make it amorphous or less crystalline. Thereby, the impact resistance of the first polyester-based resin can be improved, and the welding strength can be increased.

The dialkyl-substituted diol is a linear diol having n carbon atoms represented by the general formula HO(CH ₂ ) _n OH, in which two hydrogen atoms out of a total of 2n hydrogen atoms are substituted with alkyl groups. there is The carbon number n of the main chain is, for example, within the range of 1-6. The positions a and b of the carbon atoms to be substituted with alkyl groups can be independently selected within the range of 1 or more and n or less.

When the dialkyl substitution position a or b of the diol is equal to 1 or n, the hydroxyl group becomes a secondary alcohol or a tertiary alcohol, so the condensation reaction with the carboxylic acid component may be difficult to proceed during polyester synthesis. There is Therefore, the positions a and b of alkyl group substitution are preferably greater than 1 and smaller than n.

When the alkyl group substitution positions a and b are equal, the general formula of the dialkyl-substituted diol is HO(CH ₂ ) _a-1 C(R ¹ )(R ² )(CH ₂ ) _na OH. Each of R ¹ and R ² is 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 isopropyl group having 3 carbon atoms, a butyl group and isobutyl group having 4 carbon atoms, a pentyl group having 5 carbon atoms, an isopentyl group and the like. is mentioned.

The carbon number n of the main chain of the dialkyl-substituted diol is more preferably 3-4, and the carbon number of the alkyl groups R ¹ and R ² is more preferably 1-4. For example, for neopentyl glycol or 2-butyl-2-ethyl-1,3-propanediol, n=3 and a=b=2. In neopentyl glycol, 2,2-dimethyl-1,3-propanediol, R ¹ and R ² are methyl groups. In 2-butyl-2-ethyl-1,3-propanediol, R ¹ and R ² are butyl and ethyl groups respectively.

In the resin composition of the molded article, the first polyester resin is mainly composed of polyethylene terephthalate resin modified with diol having dialkyl substitution, and may further contain other polyester resin or thermoplastic resin.

In the resin composition for the molded article, the intrinsic viscosity (IV) of the first polyester resin is preferably 0.60 to 0.85 dl/g. The limiting viscosity in the present invention is a value measured at 30° C. in a mixed solvent of phenol/1,1,2,2-tetrachloroethane (mass ratio 1/1) according to JIS K 7367-5. This makes it easier to achieve both performance such as non-adsorptive properties and moldability of the resin.

In the resin composition of the molded product, the polyethylene-based resin can improve the impact resistance of the resin composition and increase the welding strength. The polyethylene-based resin may be a homocopolymer of polyethylene or a copolymer of ethylene and a monomer other than ethylene. Monomers other than ethylene include propylene, olefins having 4 carbon atoms (1-butene, etc.), olefins having 6 carbon atoms (1-hexene, etc.), olefins having 8 carbon atoms (1-octene, etc.), and the like. be done. The polyethylene-based resin may be a polymer obtained by polymerizing only a hydrocarbon-based monomer without containing a polar monomer such as vinyl acetate, such as an ethylene-vinyl acetate copolymer (EVA). Specific examples of polyethylene-based resins include, but are not limited to, high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and the like.

In the resin composition of the molded product, the compatibilizer has compatibility with the polyethylene resin and reacts with the hydroxyl group (-OH) or carboxyl group (-COOH) which is the terminal group of the first polyester resin. It has an epoxy group (>O) as a functional group capable of Examples of such a compatibilizer include a copolymer containing at least an olefin such as ethylene and a monomer having an epoxy group (epoxy group-containing monomer).

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

The copolymer that serves as a compatibilizer may be further copolymerized with a monomer having a functional group other than an epoxy group. 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 containing ethylene as a main component and at least glycidyl methacrylate (GMA) as an epoxy group-containing monomer. Such copolymers include ethylene-glycidyl methacrylate copolymers. The content of the epoxy group-containing monomer in the epoxy group-containing copolymer is not particularly limited, but is preferably 2 to 30% by weight, more preferably 5 to 20% by weight.

The compatibilizer may contain a copolymer chain of (meth)acrylic acid or/and (meth)acrylate and ethylene. The copolymer chain may be an ethylene-glycidyl (meth)acrylate copolymer chain. These copolymer chains may be the backbone or/and side chains of the copolymer. Here, (meth)acrylic acid means acrylic acid and/or methacrylic acid. (Meth)acrylate means acrylate and/or methacrylate.

Molded articles of embodiments may contain a compatibilizer and/or the compatibilizer may be added to the resin. Here, the fact that the compatibilizer is added to the resin may be, for example, a state in which the functional group contained in the compatibilizer is covalently bonded to the functional group contained in the resin, or It may be in a state of being attached by hydrogen bonding, hydrophobic interaction, π-π interaction, or the like.

The resin composition of the molded article preferably contains the first polyester-based resin as a main component, and further preferably contains a polyethylene terephthalate resin modified with the diol having dialkyl substitution as a main component. The compounding ratio of the first polyester-based resin, the polyethylene-based resin, and the compatibilizer having an epoxy group is such that the total of the resin composition or resin components of the molded product is 100 parts by weight, for example, the first polyester-based resin 50 to 90 parts by weight of the base resin, 3 to 35 parts by weight of the polyethylene resin, and 1 to 20 parts by weight of the compatibilizing agent.

The proportion of the first polyester-based 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, or the like. The ratio of the polyethylene-based 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, or the like. The proportion of the compatibilizer may be, for example, 3 parts by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, or the like.

Appropriate additives other than the resin component can be added to the resin composition of the molded article within a range that does not impair the purpose of the resin composition. Examples of additives include at least one of antioxidants, lubricants, antiblocking agents, flame retardants, ultraviolet absorbers, light stabilizers, antistatic agents, colorants, and the like. Whether or not these additives are contained in the resin composition can be independently selected.

In the molded article of the embodiment, the first polyester-based resin and the polyethylene-based resin may form a sea-island structure. This sea-island structure may be a sea-island structure in which the first polyester-based resin constitutes the sea portion and the polyethylene-based resin constitutes the island portion. The resin composition used for the molded article of the embodiment can form a sea-island structure by dissolving the first polyester-based resin and the polyethylene-based resin via a compatibilizer or the like.

The method for observing the sea-island structure is not particularly limited, but a thin piece obtained by cutting a cross section of the molded product with a microtome is stained with ruthenium tetroxide and observed at a magnification of 20,000 using a field emission scanning electron microscope. An image may be acquired using image analysis software, and the islands of the sea-island structure may be extracted as circular or elliptical shapes.

When the islands of the sea-island structure are extracted as circles or ellipses using image analysis software, the area ratio of the islands to the entire sea-island structure is preferably 5 to 40%, preferably 10 to 30%. It is more preferable to have These islands are made of polyethylene resin. Here, “extracting an island portion as a circular or elliptical shape” means that even if the shape of the island portion in the image is neither circular nor elliptical, the area is calculated by converting it into a circular or elliptical shape. . For example, the area ratio can be calculated by extracting each island portion as a circular or elliptical shape and totaling the areas of the circle or ellipse. Further, "the entire sea-island structure portion" means the entire "sea-island structure portion for which an image is acquired". The sum of the area ratio occupied by the sea portion and the area ratio occupied by the island portion of the sea-island structure is 100%. In other words, in the above case, the area ratio occupied by the sea is 60 to 95% or 70 to 90%.

The average grain size of the islands when the islands of the sea-island structure are extracted as circles or ellipses using image analysis software is preferably 0.1 to 2.0 μm. These islands are made of polyethylene resin. Here, “extracting an island portion as a circular or elliptical shape” means that even if the shape of the island portion in the image is neither circular nor elliptical, the diameter is calculated by converting it into a circular or elliptical shape. . For example, it is possible to take out each island part as a circle or an ellipse, find the average value of the diameter of the circle, the major axis and the minor axis of the ellipse, and calculate the average value thereof.

The resin composition for molded articles can be used to mold molded articles used as the mouth, bottom, and the like in the packaging container of the embodiment. The molding method of the molded product is not particularly limited, and injection molding, extrusion molding, blow molding, in-mold molding and the like can be mentioned. The molded product may be a resin molded product using the resin composition described above alone, or may be a resin molded product obtained by laminating a resin molded part made of the resin composition described above and another resin. The molded product can also be produced by molding the resin composition described above on the body.

The trunk portion may have a layer containing the second polyester-based resin on the surface to be joined to the molded product. The body may be formed from a single layer of the layer containing the second polyester-based resin. The body may be formed from a laminate having a layer containing the second polyester resin on the surface to be joined to the molded product.

The second polyester-based resin used for the surface of the body to be joined to the molded product is not particularly limited, but is preferably an amorphous or low-crystalline polyester-based resin such as modified polyethylene terephthalate resin. As with the molded article, it may be a polyethylene terephthalate resin modified with a diol having dialkyl substitution. The second polyester-based resin used for the surface of the body portion to be joined to the molded article may be the same polyester-based resin as the first polyester-based resin used for the molded article, or may be a different polyester-based resin. The resin layer used for the surface of the trunk portion to be joined to the molded product may contain a polyethylene resin, a compatibilizer, and the like as resin components other than the second polyester resin.

The same resin composition as that of the molded product described above can be used to mold the resin layer that is joined to the molded product of the trunk portion. The resin composition described above is excellent in impact resistance and welding strength, and is therefore suitable as a sealant for the surface to be joined to the body molded article.

If the body is formed from a laminate, it is preferred that the sealant for the surface to be joined with the molded article is placed on at least one side of the laminate. By bonding the innermost layer of the body to the outer peripheral surface of the molded product, it is easy to match the shape of the body with the shape of the molded product. In this case, it is preferable to place the sealant on the innermost layer of the barrel. When the outer periphery of the molded article extends to the outside of the barrel, it is also possible to arrange the sealant on the outermost layer of the barrel to join the molded article. It is also possible to dispose the sealant on the innermost layer and the outermost layer of the barrel so that the outer peripheral portion of the molded product sandwiches the innermost layer and the outermost layer of the barrel.

When forming the body from a laminate, a base material can be provided as a resin layer other than the sealant. As the base material, a resin film having excellent mechanical properties such as heat resistance and strength and printability is preferable. Specifically, polyethylene terephthalate film, nylon film, polypropylene film, polyolefin film and the like can be mentioned. A stretched film may be sufficient as the resin film of a base material. The thickness of the substrate in the laminated body of the body is not particularly limited, but may be, for example, 10 to 50 μm.

A sheet-like laminate that is thicker than the laminated film may be used for manufacturing the packaging container. The laminate may be soft and flexible. 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 substrates may be laminated in two or more layers.

A layer of anchoring agent or adhesive may be interposed between the layers forming the laminate, such as between the sealant and the substrate, if necessary. When the sealant is formed by extrusion lamination, an anchor layer is formed in contact with the sealant. When the sealant contains the second polyester-based resin as a main component and the substrate is a polyester film such as polyethylene terephthalate, the anchor layer may not be used. When a sealant that has been prepared in advance as a film-like molded product is adhered to a substrate by a dry lamination method, an adhesive layer is formed in contact with the inside of the sealant. Moreover, when using a coextrusion method, you may use adhesive resin, such as an acid-modified polyolefin, between a sealant and a base material.

As the anchoring agent constituting the anchoring agent layer, there can be used anchoring agents generally used in the extrusion lamination method, such as polyurethane-based, polyether-based, and alkyl titanate (organic titanium compound)-based anchoring agents. As the adhesive constituting the adhesive layer, polyurethane-based, polyether-based, and other adhesives generally used in the dry lamination method can be used.

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

The packaging container of the first embodiment is, as shown in FIG. 1, a cylindrical container 10 in which a mouth portion 12 and a bottom portion 13 are joined to both ends of a cylindrical body portion 11, respectively. At least one of the mouth portion 12 and the bottom portion 13 is molded from the resin composition of the molded article described above. The trunk portion 11 may be formed in a cylindrical shape.

As shown in FIG. 2, the packaging container of the second embodiment is a tube container in which a mouth portion 22 is joined to one end of a tube-shaped body portion 21 and the other end of the body portion 21 is sealed by a sealing portion 23. is 20. The mouth portion 22 is molded from the resin composition of the molded article described above. The sealing portion 23 is formed by crushing the other end of the trunk portion 21 and joining the inner surfaces thereof.

The packaging container of the third embodiment is, as shown in FIG. 3, a pouch container 30 in which a mouth portion 32 is joined to at least one peripheral portion of a bag-shaped body portion 31 formed from a packaging film. The mouth portion 32 is molded from the resin composition of the molded article described above. The form of the pouch-shaped body 31 is not particularly limited, but examples thereof include a three-sided bag, a four-sided bag, a folded bag, a gusseted bag, and a standing pouch. The trunk portion 31 may be a large packaging bag such as an inner bag for a bag-in-box.

Since the packaging container of the embodiment contains the first and second polyester-based resins on the molded article to be joined to the body and the surface of the body to be joined to the molded article, respectively, the low-molecular-weight component is non-adsorbable and It also has excellent barrier properties. Furthermore, since the molded article to be joined to the body is formed from the resin composition of the molded article described above, it is excellent in impact resistance and welding strength. For example, even when the packaging container falls, collides, etc., it is possible to suppress breakage and deterioration of joints, etc., and improve durability such as drop strength.

Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

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

(resin composition)
Raw material resins were blended at the ratios shown in Tables 1 and 2 and melt-kneaded to prepare pellets of the resin composition. Subsequently, the pellets were formed in a hot press to a thickness of 0.5 mm to obtain single-layer pressed sheet samples.

When showing the compositions of the resins in Tables 1 and 2, the numerical values of the compounding ratios are added to the right of the symbols of the raw material resins below as parts by weight. For example, "A-1 80" indicates that 80 parts by weight of Resin A-1 were used. The raw material resins shown in Tables 1 and 2 are as follows.

"Polyester resin" in Tables 1 and 2 is the first polyester resin contained in the molded product, but it is the second polyester resin contained in the surface to be joined to the molded product of the trunk. may

(A) Polyester-based resin “A-1”: amorphous neopentyl glycol (NPG)-modified polyethylene terephthalate (PET) resin (density ρ=1.29 g/cm 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)

(B) Polyethylene-based resin “B-1”: metallocene-catalyzed C6-LLDPE (density ρ=0.915 g/cm ³ , melting point Tm=121° C., MFR=1 g/10 min (190° C., 2.16 kgf))

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

A test was carried out by the following method using the prepared pellet or pressed sheet sample.

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

(2) Bending test Using a sample prepared by cutting a press sheet to a width of 15 mm, a bending test was performed at 1.5 kgf and an angle of 135° using an MIT folding endurance tester (manufactured by Tester Sangyo Co., Ltd.). The number of times of bending until breaking was measured.

(3) Seal strength According to JIS Z 1526, two samples prepared by cutting a press sheet to a width of 15 mm were heat-sealed so that the seal strength (15 mm / N) of the sample was measured at a tensile speed of 300 mm / min. , width 15 mm. The heat welding conditions were the temperature shown in Tables 1 and 2, mainly selected at 180° C., the pressure of 0.2 MPa, and the heating time of 1 second.

Tables 1 and 2 show the above results.

It was found that samples of molded articles formed from the resin compositions of Examples 1 to 6 were excellent in impact resistance and welding strength. As the epoxy groups of the compatibilizer progressed the cross-linking of the polyester resin, the viscosity increased and the MFR tended to decrease.
The samples of Comparative Examples 1 and 2 had a low number of times of bending in the bending test and low impact resistance.

(Evaluation of non-adsorptive property)
A press sheet having a thickness of 0.5 mm molded using the resin compositions of Examples 1 and 6 shown in Table 1 was cut into a size of 7 mm in width and 30 mm in length to prepare a non-adsorptive evaluation sample. Similarly, non-adsorptive evaluation samples were molded using the following polyethylene resins. Comparative Example 3 was obtained using the polyethylene resin B-2, and Comparative Example 4 was obtained using the polyethylene resin B-3.

(B) Polyethylene-based resin “B-2”: metallocene-catalyzed LLDPE (density ρ=0.924 g/cm ³ , melting point Tm=120° C., MFR=2.2 g/10 min (190° C., 2.16 kgf))
“B-3”: HDPE (density ρ=0.949 g/cm ³ , melting point Tm=130° C., MFR=1.1 g/10 min (190° C., 2.16 kgf))

Non-adsorptive evaluation was performed by the following method using a non-adsorptive evaluation sample.

(4) Measurement method of tocopherol acetate residual rate Together with a non-adsorbent evaluation sample, put 3 ml of a commercially available lotion containing α-tocopherol acetate (vitamin E acetate) as an active ingredient in a 3 ml brown bottle, cap it and seal it. bottom. 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. A rate (%) was calculated.

The measurement results of the tocopherol acetate residual rate are as follows.
Example 1: 97.2%
Example 6: 97.3%
Comparative Example 3: 59.6%
Comparative Example 4: 61.0%

When the resin compositions of Examples 1 and 6 were used, the tocopherol acetate residual rate was high. Although no specific measurement results are shown, it is assumed that, similarly to Examples 1 and 6, high tocopherol acetate residual ratios can be obtained when the resin compositions of Examples 2 to 5 are used.

(Observation of sea-island structure)
A thin piece obtained by cutting a cross section of a sample of a molded article formed from the resin composition of Examples 1 to 6 with a microtome is stained with ruthenium tetroxide, and is examined using a field emission scanning electron microscope at a magnification of 20,000. An image was obtained by observation, and the island part of the sea-island structure was extracted as a circular or elliptical shape using image analysis software. Table 3 shows the ratio of the area occupied by the islands to the entire sea-island structure and the average grain size of the islands. For the average particle size, the diameter of the extracted circle and the average value of the major axis and minor axis of the extracted ellipse were obtained, and these average values were used as the average particle size.

An example of an electron micrograph showing a sea-island structure is shown in FIG. However, the size of FIG. 4 may have been changed from the original image, and the magnification is not always 20,000.

DESCRIPTION OF SYMBOLS 10... Cylindrical container 11... Body part of a cylindrical container 12... Mouth part of a cylindrical container 13... Bottom part of a cylindrical container 20... Tube container 21... Body part of a tube container. 22... Opening of tube container, 23... Sealing part of tube container, 30... Pouch container, 31... Body of pouch container, 32... Opening of pouch container.

Claims (13)

A molded product molded from a resin composition containing a first polyester-based resin, a polyethylene-based resin, and a compatibilizer having an epoxy group, and a body portion joined to the molded product,
The body has a layer containing a second polyester resin on the surface to be joined with the molded product,
The second polyester resin may be the same resin as the first polyester resin, or may be a different resin,
A packaging container, wherein the first polyester resin contained in the resin composition of the molded article is a polyethylene terephthalate resin modified with a diol having dialkyl substitution. The packaging container according to claim 1, wherein the diol having dialkyl substitution is neopentyl glycol or 2-butyl-2-ethyl-1,3-propanediol. 3. The packaging container according to claim 1, wherein the compatibilizer having an epoxy group is ethylene-glycidyl methacrylate. 3. The packaging container according to claim 1, wherein at least one of the mouth portion and the bottom portion is formed from the molded product. 3. The packaging container according to claim 1, wherein the body has a tubular shape having a mouth and a bottom at both ends. 3. The packaging container according to claim 1 or 2, wherein the body has a tubular shape with one end joined to the mouth and the other end crushed and sealed. 3. The packaging container according to claim 1, wherein said body is formed from a pouch. Having a molded article containing a first polyester resin and a polyethylene resin, and a body portion joined to the molded article,
The body has a layer containing a second polyester resin on the surface to be joined with the molded product,
The second polyester resin may be the same resin as the first polyester resin, or may be a different resin,
The molded product has a resin composition that forms a sea-island structure in which the first polyester-based resin constitutes a sea portion and the polyethylene-based resin constitutes an island portion,
The packaging container, wherein the first polyester-based resin is a diol-modified polyethylene terephthalate resin having dialkyl substitution. A thin piece obtained by cutting a cross section of the molded article with a microtome is stained with ruthenium tetroxide, and an image is obtained by observing at 20,000 times using a field emission scanning electron microscope, and using image analysis software. 9. The packaging container according to claim 8, wherein when the islands of the sea-island structure are extracted as circular or elliptical shapes, the area ratio of the islands to the entire sea-island structure is 5 to 40%. The islands composed of the polyethylene-based resin have an average particle diameter of 0.1 to 2.0 μm when the islands of the sea-island structure are extracted as circles or ellipses using image analysis software. Item 9. The packaging container according to Item 9. 9. The packaging container according to claim 8, wherein the molded article further contains a compatibilizer or/and the compatibilizer is added to the resin. The packaging container according to claim 11, wherein the compatibilizer contains a copolymer chain of (meth)acrylic acid or/and (meth)acrylic acid ester and ethylene. The packaging container according to claim 12, wherein the copolymer chain is an ethylene-glycidyl (meth)acrylate copolymer chain.

Images