JP6481425B2 - Thermoplastic resin composition, easy-open lid and easy-open container - Google Patents

Description

  The present invention relates to a thermoplastic resin composition that is excellent in the balance between heat seal strength and easy-openability, and that can form a seal layer excellent in peeling appearance and the like with good moldability. The present invention also relates to an easily openable lid material and an easily openable container obtained using this thermoplastic resin composition.

  Conventionally, as a packaging method for foods, beverages, medicines, cosmetics, medical instruments, etc., an article to be packaged is put in a container body molded in a tray shape or a cup shape with a resin such as a polyester resin or a polycarbonate resin, A method in which a lid is brought into contact with the opening and sealed by heat sealing is widely used. In this type of package, there is no leakage of the package from the container, and it is necessary to peel off the lid when removing the package. It is necessary to have a heat seal strength that is as high as possible, that is, to be easily openable.

  Generally, there are mainly two types of sealants (sealing materials) used for easy-opening lid materials: delamination type and cohesive peeling type. The delamination-type lid material is composed of a seal layer, a holding layer, and a base material, and the seal layer is formed of the same kind of resin as the adherend (the lid attachment portion of the container), A strong sealing state is maintained by heat-sealing, and the holding layer is formed of a resin different from the sealing layer, and is easily peeled between the sealing layer and the holding layer to provide easy opening. .

  However, with a delamination type sealant, a part of the sealant remains on the container side at the time of opening, or a film residue occurs at the time of opening, so the cohesive peeling type sealant is advantageous in that there is no such problem. is there. The cohesive peeling type sealant is the same as the delamination type in that it is formed of a seal layer, a holding layer, and a base material. However, the seal layer is made of the same kind of resin as the adherend and the same kind of resin as the holding layer. It is formed from a polymer blend of seed resins. Thereby, at the time of heat sealing, the sealing layer is partially heat-sealed with the adherend, and at the time of peeling, the sealing layer is peeled off while cohesively breaking at the interface of the polymer blended resin. Therefore, the sealing layer has both the sealing and peeling functions, but the heat sealing between the sealing layer and the adherend is partial, so that a sealing strength exceeding a certain level cannot be obtained. There is a point.

  Conventionally, as a cohesive peel type sealant, for example, Patent Document 1 discloses a seal layer that is made of a thermoplastic resin having a specific tensile breaking strength, which eliminates the problem of stringing at the time of opening. Has been. Patent Document 2 discloses a structure in which a sealing layer is made of a lacquer of a polyester resin and a urethane resin so as to leave a uniform trace on the lid. Furthermore, Patent Document 3 discloses that a sealing layer contains foamed particles to enable selective cohesive peeling and to prevent peeling failure.

JP 2005-335818 A JP 2008-7146 A JP2013-75718A

Even in the techniques disclosed in the above Patent Documents 1 to 3, a sufficient one is still provided for the requirement to achieve both easy opening and heat seal strength while ensuring film formability as a sealing layer. This is not the case, and further improvements are desired. In particular, sealants used for containers for food and drink products are also required to have a good appearance after peeling (peeling appearance).

  The present invention provides a thermoplastic resin composition that has a sufficiently high heat seal strength, can be formed with a good moldability, and a thermoplastic resin composition that can form a sealing layer that is easy to open and have a peeled appearance. It is an object of the present invention to provide an easily openable lid material having a sealed layer and an easily openable container having the lid material.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by blending a specific fusion component, an aggregating release component, and a moldability auxiliary component. Thus, the present invention has been completed. That is, the gist of the present invention is as follows [1] to [8].

[1] A thermoplastic resin composition comprising the following components (A) to (C).
Component (A): Polyester having a melting peak temperature of 110 to 150 ° C. Component (B): Amine-modified styrenic thermoplastic elastomer (C) Component: Amorphous polyester and / or polyolefin

[2] The total amount of the component (A), the component (B) and the component (C) is 10 to 90% by weight of the component (A), 3 to 50% by weight of the component (B), and the component (C). The thermoplastic resin composition according to [1], containing 5 to 50% by weight.

[3] The thermoplastic resin composition according to [1] or [2], comprising polyethylene having a density of 0.850 to 0.980 g / cm ³ as the component (C).

[4] As the component (C), the terephthalic acid unit is contained in an amount of 80 mol% or more based on the total dicarboxylic acid unit, the ethylene glycol unit is composed of 60 to 80 mol%, and the cyclohexanedimethanol unit is composed of 20 to 20 The thermoplastic resin composition according to any one of [1] to [3], comprising an amorphous polyester containing 40 mol%.

[5] The thermoplastic resin composition according to any one of [1] to [4], wherein the glass transition temperature (Tg) of the component (A) is −80 to 0 ° C.

[6] An easily-openable container lid member having a seal layer formed of the thermoplastic resin composition according to any one of [1] to [5].

[7] An easy-open container having the easy-open lid according to [6].

[8] An easy-open container comprising the easy-open lid material according to [6] and a container made of polyethylene terephthalate resin.

  According to the thermoplastic resin composition of the present invention, a heat seal strength is sufficiently high, and a seal layer excellent in easy-opening property, peeled appearance, etc. can be formed with good moldability. Moreover, an easily openable lid | cover material and an easily openable container are provided by using the thermoplastic resin composition of this invention.

Embodiments of the present invention will be described in detail below, but the descriptions described below are examples (representative examples) of embodiments of the present invention, and the present invention is not limited to these contents unless it exceeds the gist. It is not specified. In addition, in this invention, when expressing by putting a numerical value or a physical-property value before and behind using "-", it shall use as what includes the value before and behind.

The thermoplastic resin composition of the present invention includes the following components (A) to (C).
Component (A): Polyester having a melting peak temperature of 110 to 150 ° C. Component (B): Amine-modified styrenic thermoplastic elastomer (C) Component: Amorphous polyester and / or polyolefin

  In the present invention, the component (A) functions as a fusion component responsible for heat sealability, and the component (B) is a component responsible for cohesive peelability (easy-opening property) and a good peel appearance. Component C) functions as a moldability auxiliary component for improving moldability. By including these components, the thermoplastic resin composition of the present invention can form a seal layer excellent in easy-openability, heat-sealability, and peel appearance with good moldability.

[(A) component]
The component (A) used in the thermoplastic resin composition of the present invention is a polyester having a melting peak temperature of 110 to 150 ° C. The thermoplastic resin composition of the present invention is imparted with heat sealability by including the component (A).

  The polyester (A) is produced by an esterification reaction between a dicarboxylic acid and a polyhydric alcohol or an ester exchange reaction between a dicarboxylic acid ester and a polyhydric alcohol. Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid, succinic acid, suberic acid, and sebacic acid. The polyhydric alcohol is preferably a diol, for example, ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, pentaethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol, neo Examples include pentyl glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. Said dicarboxylic acid and / or its ester, and a polyhydric alcohol can be used by arbitrary combinations. For example, terephthalic acid / ethylene glycol copolymer, 2,6-naphthalenedicarboxylic acid / ethylene glycol copolymer, terephthalic acid / isophthalic acid / 1,4-butanediol copolymer, terephthalic acid / adipic acid / 1 , 4-butanediol copolymer, terephthalic acid / isophthalic acid / 1,4-butanediol / polytetramethylene ether glycol copolymer, and the like.

  The (A) component polyester used in the present invention has a melting peak temperature of 150 ° C. or lower, and therefore has a function of fusing from a low temperature to an adherend at this temperature or lower. From the viewpoint of making this function better, the melting peak temperature is preferably 145 ° C. or lower, and more preferably 140 ° C. or lower. On the other hand, the polyester of component (A) has a melting peak temperature of 110 ° C. or higher. For this reason, after fusing to the adherend, during the heat treatment of the container (easy-open container) or high temperature into the container It has a function of preventing the sealant layer from being peeled off (peeling strength is lowered) at the time of injection of an object. From the viewpoint of making this function better, the melting peak temperature is preferably 115 ° C. or higher.

  Moreover, it is preferable from a viewpoint of the blocking resistance of a film that the glass transition temperature (Tg) of (A) component is -80 degreeC or more. From this viewpoint, the glass transition temperature of the component (A) is preferably −70 ° C. or higher, and more preferably −65 ° C. or higher. On the other hand, the upper limit of the glass transition temperature (Tg) of the component (A) is not particularly limited, but is usually 0 ° C. or lower.

In addition, the melting peak temperature and glass transition temperature of (A) component can be measured according to JISK7121. Specifically, the following steps (1) to (3) are sequentially performed using a differential scanning calorimeter (DSC 6220, manufactured by SSI Nanotechnology Inc.) to measure the melting behavior of the polyester resin. In each step, time is plotted on the horizontal axis, and the heat of fusion is plotted on the vertical axis to obtain a melting curve. The peak observed in step (2) is the crystallization peak, and the peak observed in step (3) is the melting peak. .
Step (1): About 6 mg of the sample is heated from room temperature to 170 ° C. at a rate of 100 ° C./min, and held for 3 minutes after the temperature increase is completed.
Step (2): The temperature is decreased from 170 ° C. to −80 ° C. at a rate of 10 ° C./min, and held for 3 minutes after the temperature decrease.
Step (3): The temperature is raised from −80 ° C. to 170 ° C. at a rate of 10 ° C./min.

  (A) Polyester of a component can be obtained as a commercial item. For example, a corresponding product can be selected and used from “Byron (registered trademark)” series manufactured by Tohobo Co., Ltd. and “ECOFLEX (registered trademark)” manufactured by BASF. In addition, as a polyester of a component (A), you may use by 1 type, However, You may use 2 types combining different physical properties, such as a dicarboxylic acid component, a diol component, or a glass transition temperature.

[Component (B)]
The component (B) used in the present invention is an amine-modified styrenic thermoplastic elastomer. By including the amine-modified styrenic thermoplastic elastomer in the thermoplastic resin composition of the present invention, it has cohesive peelability (easy-opening property) and good peel appearance. This is considered due to the fact that the dispersion diameters of the component (A) and the component (C) are refined by the component (B).

  The styrenic thermoplastic elastomer used as the amine-modified raw material is not limited, but those having a polymer block mainly composed of a vinyl aromatic compound and a polymer block imparting flexibility are usually used. Specifically, it is obtained by hydrogenating a block copolymer having a polymer block mainly composed of a vinyl aromatic compound and a polymer block mainly composed of butadiene and / or isoprene and / or the block copolymer. And hydrogenated block copolymers.

  Here, the “polymer mainly composed of a vinyl aromatic compound” means a polymer obtained by polymerizing a monomer mainly composed of a vinyl aromatic compound, and hereinafter referred to as “polymer block P” or “block P”. May be abbreviated. The “polymer mainly composed of butadiene and / or isoprene” means a polymer obtained by polymerizing a monomer mainly composed of butadiene and / or isoprene, and hereinafter referred to as “polymer block Q” or “block Q”. May be abbreviated. Here, “mainly” means 50 mol% or more. Further, a block copolymer having at least two polymer blocks P and at least one polymer block Q and / or a hydrogenated block copolymer obtained by hydrogenating the block copolymer are preferable.

  The monomeric vinyl aromatic compound constituting the polymer block P is not limited, but styrene derivatives such as styrene and α-methylstyrene are preferable. Among these, it is preferable to mainly use styrene. The polymer block may contain a monomer other than the vinyl aromatic compound as a raw material.

The block Q is more preferably any one of butadiene alone, isoprene alone, butadiene and isoprene. The block Q may contain monomers other than butadiene and isoprene as raw materials. Further, the block Q may be a hydrogenated derivative obtained by hydrogenating a double bond having after polymerization. Although the hydrogenation rate of the block Q is not limited, 50-100 weight% is preferable and 80-100 weight% is preferable. By hydrogenating the block Q within the above range, the thermal stability of the laminate of the present invention tends to be improved. The same applies to the case where the block P uses a diene component as a raw material. The hydrogenation rate can be measured by ¹³ C-NMR.

  The weight ratio of the block P in the styrenic thermoplastic elastomer is not limited, but is usually 5% by weight or more, preferably 8% by weight or more, more preferably 10% by weight or more, and usually 55% by weight. % Or less, preferably 50% by weight or less, and more preferably 45% by weight or less. When the weight ratio of the block P is within the above range, the adhesiveness of the thermoplastic resin composition of the present invention tends to be good.

  When the copolymer having the block P and the block Q is used as the styrenic thermoplastic elastomer, the chemical structure may be any of linear, branched, radial, etc., but the following formula (1) Or the case where it is a block copolymer represented by (2) is preferable, and it is a structure of following formula (1) from an adhesive viewpoint more preferably.

Furthermore, the block copolymer represented by the following formula (1) or (2) is more preferably a hydrogenated derivative (hereinafter sometimes abbreviated as a hydrogenated block copolymer). When the copolymer represented by the following formula (1) or (2) is a hydrogenated block copolymer, the adhesiveness of the thermoplastic resin composition of the present invention tends to be good.
P- (QP) _m (1)
(PQ) _n (2)
(In the formula, P represents the polymer block P, Q represents the polymer block Q, m represents an integer of 1 to 5, and n represents an integer of 2 to 5.)

  In the formula (1) or (2), m and n are preferably large in terms of lowering the order-disorder transition temperature as a rubbery polymer, but small in terms of ease of production and cost. . In the present invention, m and n are preferably given by integers of 1 to 5, more preferably 2 to 4.

  The block copolymer or hydrogenated block copolymer (hereinafter collectively referred to as “(hydrogenated) block copolymer”) is represented by the formula (2) because it is excellent in rubber elasticity. ) A (hydrogenated) block copolymer represented by formula (1) is preferred to a block copolymer, and (hydrogenated) block copolymer represented by formula (1) wherein m is 3 or less. (Hydrogenated) block copolymer represented by the formula (1) in which m is 2 or less is more preferable.

  The method for producing the styrene thermoplastic elastomer in the present invention is not particularly limited as long as the above structure and physical properties can be obtained. Specifically, for example, it can be obtained by performing block polymerization in an inert solvent using a lithium catalyst or the like. In addition, a known method such as hydrogenation (hydrogenation) of the block copolymer can be employed, for example, in an inert solvent in the presence of a hydrogenation catalyst.

The component (B) in the present invention is obtained by modifying the above-described styrenic thermoplastic elastomer with an amine compound. The method for amine-modifying the styrene-based thermoplastic elastomer is not particularly limited. For example, as illustrated in the method described in JP-A-2007-154014, a polymerization initiator having an amino group (water Addition) A method of modifying an amine by polymerizing a block copolymer, a method of modifying an amine with a (hydrogenated) block copolymer by using an unsaturated monomer having an amino group as a raw material, (water A) A method of modifying an amine by reacting a polymerization terminator having an amino group with the active site of the block copolymer. These methods may be performed alone or in combination of a plurality of methods.

  Furthermore, as a method for amine-modifying a styrene-based thermoplastic elastomer composition, a (hydrogenated) block copolymer containing chloromethylstyrene units is synthesized using chloromethylstyrene as a raw material for the styrene-based thermoplastic elastomer composition. And the method of amine-modifying a styrene-type thermoplastic elastomer composition by making an amine compound react with the chloromethyl group can also be used. At this time, the amine compound for modification is not limited, and specific examples include alkylamines, alkenylamines, arylamines, arylalkylamines, cyclic alkylamines, heterocyclic amines, and the like. . Examples of alkylamines include methylamine, ethylamine, propylamine, isopropylamine, n-butylamine, sec-butylamine, isobutylamine, tert-butylamine, pentylamine and the like. Examples of alkenylamines include dodecenylamine, octadecenylamine, and dococenylamine. Examples of arylamines include aniline, methylaniline, ethylaniline, p-isopropylaniline, N-methylaniline and the like. Examples of arylalkylamines include benzylamine, 1-phenylethylamine, 2-phenylethylamine and the like. Examples of cyclic alkylamines include cyclohexylamine and dicyclohexylamine. Examples of the heterocyclic amines include thienylamine and quinolylamine. These amine compounds may be used alone or in combination of two or more appropriately selected.

  The amount of modification by the amine compound in the amine-modified styrenic thermoplastic elastomer is not limited, but is preferably 0.05 to 20% by weight in the amine-modified styrenic thermoplastic elastomer, and 1 to 10% by weight. It is more preferable that When the modification amount by the amine compound is less than the lower limit, the adhesiveness between the thermoplastic resin composition of the present invention and the aliphatic polyester resin tends to decrease. On the other hand, when the modification amount by the amine compound exceeds the upper limit, coloring or odor of the thermoplastic resin composition may occur.

  The method for amine-modifying the styrene-based thermoplastic elastomer is not limited and can be obtained by a method of reacting in an organic solvent (solution method) or a melt-kneading (melt-kneading method) using an extruder or the like. As the solvent for amine modification using the solvent method, for example, dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), N, N-diethylformamide, etc., both styrenic thermoplastic elastomers and amine compounds are acceptable. A soluble solvent can be preferably used. The temperature at which the amine is modified is appropriately determined depending on the type of solvent used and the type of amine compound, but is usually in the range of 0 to 150 ° C. Further, a radical generator or a reaction accelerator may be added upon modification. In the case of amine modification using a melt-kneading method, in addition to a styrene thermoplastic elastomer and an amine compound, a radical generator can be added and melt-kneaded.

  The number average molecular weight of the (B) component styrene-based thermoplastic elastomer is not limited, but is usually 250,000 or less, preferably 150,000 or less, more preferably 120,000 or less, and still more preferably 100,000 or less. The number average molecular weight of the styrenic thermoplastic elastomer is not limited, but is usually 20,000 or more, preferably 40,000 or more, more preferably 50,000 or more. When the number average molecular weight of the styrenic thermoplastic elastomer is within the above range, the moldability tends to be good. The number average molecular weight of the styrenic thermoplastic elastomer is a value in terms of polystyrene measured by gel permeation chromatography (hereinafter sometimes abbreviated as GPC).

Although the melt flow rate (MFR) by ISO 1133 of (B) component is not limited, Preferably it is 0.1 g / 10 as a value in 230 degreeC and a 2.16 kg (21.2N) load.
Min. Or more, more preferably 0.3 g / 10 min or more, still more preferably 0.5 g / 10 min or more, preferably 100 g / 10 min or less, more preferably 50 g / 10 min or less, still more preferably 30 g / 10. Is less than a minute. When the MFR of the component (B) is within the above range, the moldability tends to be good.

  The glass transition temperature of component (B) according to ISO 11357-2 is not limited, but is preferably -80 ° C or higher, more preferably -70 ° C or higher, and preferably 30 ° C or lower, more preferably It is 20 degrees C or less, More preferably, it is 0 degrees C or less. When the glass transition temperature of the component (B) is within the above range, the blocking resistance of the film tends to be good.

  The hardness (Shore A) according to ISO 868 of the component (B) is not limited, but is preferably 50 or more, more preferably 60 or more, still more preferably 75 or more, while preferably 95 or less, More preferably, it is 90 or less, More preferably, it is 85 or less. When the hardness of the component (B) is within the above range, the flexibility tends to be good.

  As the amine-modified styrenic thermoplastic elastomer used as the component (B) of the present invention, a commercially available product can be used. As a commercially available product, for example, appropriate ones from “Dynalon (registered trademark)” manufactured by JSR Corporation and “Tuftec (registered trademark)” manufactured by Asahi Kasei Chemicals Corporation can be appropriately selected and used.

[Component (C)]
(C) component used by this invention is an amorphous polyester and / or polyolefin. As the component (C), only one type of amorphous polyester or one type of polyolefin may be used, and one or more types of amorphous polyester and one or more types of polyolefin are used in combination. Also good.

<Amorphous polyester>
The amorphous polyester that can be used as the component (C) is a polyester that does not substantially exhibit crystallinity. In particular, in the measurement by the differential scanning calorimeter described above in the component (A), the polyester does not have a clear melting peak temperature in a temperature range of 50 ° C. to 300 ° C., specifically in this temperature range. Means that the heat of crystal fusion (ΔH) is 1 J / g or less.

  Examples of the amorphous polyester that can be used as the component (C) include those obtained by replacing the terephthalic acid unit of poly (ethylene terephthalate) with other dicarboxylic acid units and / or the ethylene glycol unit of poly (ethylene terephthalate). And the like that are made amorphous by substituting a part of these with other diol units. The term “dicarboxylic acid unit” as used herein means a unit derived from dicarboxylic acid if it is an amorphous polyester produced by an esterification reaction, and is an amorphous polyester produced by an ester exchange reaction. Means a unit derived from a dicarboxylic acid diester.

In such an amorphous polyester, as dicarboxylic acid units other than terephthalic acid units, 1,2-cyclohexanedicarboxylic acid units, 1,3-cyclohexanedicarboxylic acid units, 1,4-cyclohexanedicarboxylic acid units, 1,4 -Alicyclic dicarboxylic acid units such as decahydronaphthalenedicarboxylic acid units and 1,5-decahydronaphthalenedicarboxylic acid units; phthalic acid units, isophthalic acid units, phenylenedioxydicarboxylic acid units, 4,4'-diphenyldicarboxylic acid Unit, 4,4′-diphenyl ether dicarboxylic acid unit, 4,4′-diphenyl ketone dicarboxylic acid unit, 4,4′-diphenoxyethane dicarboxylic acid unit, 4,4′-diphenylsulfone dicarboxylic acid unit, 2,6- Aromatic dicarboxylic acid units such as naphthalenedicarboxylic acid units Succinic acid unit, glutaric acid unit, adipic acid unit, pimelic acid unit, suberic acid unit, azelaic acid unit, sebacic acid unit, undecalactone dicarboxylic acid units, aliphatic dicarboxylic acid units, such as dodeca dicarboxylic acid units, and the like. The dicarboxylic acid unit mentioned above may contain only 1 type, or may contain 2 or more types.

  Moreover, as diol units other than ethylene glycol, 1,2-cyclopentanediol unit, 1,3-cyclopentanediol unit, 1,2-cyclopentanedimethanol bis (hydroxymethyl) tricyclo [5.2.1. 0] decane unit, 5-membered ring diol unit such as 1,3-cyclopentanedimethanol bis (hydroxymethyl) tricyclo [5.2.1.0] decane unit; 1,2-cyclohexanediol unit, 1,3- Cyclohexanediol unit, 1,4-cyclohexanediol unit, 1,2-cyclohexanedimethanol (1,2-CHDM) unit, 1,3-cyclohexanedimethanol (1,3-CHDM) unit, 1,4-cyclohexanedim Methanol (1,4-CHDM) unit, 2,2-bis- (4-hydroxycyclo) Xylyl) -propane units and other cyclohexanedimethanol units; trimethylene glycol units, 1,4-butanediol units, pentamethylene glycol units, hexamethylene glycol units, octamethylene glycol units, decamethylene glycol units, neopentyl glycol units, Aliphatic diol units such as diethylene glycol; xylylene glycol units, 4,4′-dihydroxybiphenyl units, 2,2-bis (4′-hydroxyphenyl) propane units, 2,2-bis (4′-β-hydroxyethoxy) And aromatic diol units such as phenyl) propane unit, bis (4-hydroxyphenyl) sulfone unit, and bis (4-β-hydroxyethoxyphenyl) sulfone unit acid. Among these, it is preferable that a cyclohexane dimethanol unit is included as a diol unit. The diol units listed above may contain only one type or two or more types.

  Among these, as an amorphous polyester that can be used for the component (C), polyethylene terephthalate containing a cyclohexanedimethanol unit as a diol unit is preferable. In particular, the terephthalic acid unit is contained in an amount of 80 mol% or more based on the total dicarboxylic acid unit, and the ethylene glycol unit is contained in an amount of 60 to 80 mol% and the cyclohexanedimethanol unit is contained in an amount of 20 to 40 mol% based on the total diol unit. preferable.

  The glass transition temperature (Tg) of the amorphous polyester of component (C) is preferably 45 ° C. or higher, more preferably 55 ° C. or higher. It is preferable from a heat resistant viewpoint that the glass transition temperature of amorphous polyester is more than the said lower limit. Further, the glass transition temperature of the amorphous polyester is preferably 90 ° C. or lower, more preferably 80 ° C. or lower. When the glass transition temperature is less than or equal to the above upper limit value, the crystallinity is lowered, whereby the transparency is excellent, and the heat sealability is excellent. The glass transition temperature can be measured by a conventional method by using a differential scanning calorimeter (DSC) or the like in the same manner as the component (A) described above, and measured at a temperature rising rate of 10 ° C./min. It means the temperature at the inflection point of the heat flow. The glass transition temperature of the amorphous polyester can be controlled by appropriately selecting and using the dicarboxylic acid component and the diol component described above.

  The intrinsic viscosity (IV) of the amorphous polyester of component (C) is not particularly limited, but a lower intrinsic viscosity is preferable in view of easy molding because the melt viscosity is also lowered. Specifically, the intrinsic viscosity (IV) obtained by measuring amorphous polyester using a mixed solution of phenol / tetrachloroethane (weight ratio 1/1) as a solvent using an Ubbelohde viscometer at 30 ° C. It is preferably 1.5 dL / g or less, and from the viewpoint of physical properties such as strength, it is preferably 0.3 dL / g or more.

The amorphous polyester of component (C) can be obtained as a commercial product. For example, the corresponding product can be selected from the “Easter (registered trademark) copyester” series manufactured by Eastman Chemical Co.

<Polyolefin>
The polyolefin that can be used as the component (C) is a homopolymer or copolymer of an olefin having about 2 to 20 carbon atoms such as ethylene, propylene, butene-1, pentene-1, hexene-1, or the like. Examples include copolymers of olefins and copolymerizable vinyl monomers, for example, vinyl acetate, acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, maleic anhydride and other unsaturated organic acids or anhydrides thereof. It is done. In addition, in the copolymer of an olefin and a copolymerizable vinyl monomer, the content of olefin units is 50% by weight or more. Here, the copolymer includes random, block and graft copolymers. In addition, what corresponds to (D) component demonstrated below shall not be considered as (C) component.

  More specifically, as the polyolefin that can be used as the component (C), polyethylene, polypropylene, ethylene-propylene random copolymer, ethylene / propylene block copolymer produced by a high pressure method, a medium pressure method, or a low pressure method, A propylene / butene-1 random copolymer, a propylene / ethylene / butene-1 random copolymer, a copolymer of propylene, an α-olefin having 5 to 12 carbon atoms and optionally ethylene or butene-1, ethylene -Vinyl acetate copolymers and the like are mentioned, and among these, polyethylene, polypropylene, ethylene / vinyl acetate copolymers (those having an ethylene unit content of less than 50% by weight), etc. are preferred, especially high density polyethylene. Polyethylene such as low density polyethylene and linear polyethylene Preferred. “Polypropylene” means a component containing more than 50% by weight of a propylene unit as a constituent unit, and “polyethylene” means a component containing more than 50% by weight of an ethylene unit as a constituent unit. As the component (C), polyethylene is particularly preferable from the viewpoint of moldability.

As the polypropylene that can be used as the component (C), from the viewpoint of moldability, the melt flow rate (MFR) measured at 230 ° C. and a load of 2.16 kg according to JIS K7210 (1999) is 1.0 to 60 g / 10 min. Is preferably 2.0 to 40 g
More preferably, it is / 10 minutes.

Moreover, as a polyethylene which can be used as a component (C), the melt flow rate (MFR) measured by 190 degreeC and the load 2.16kg according to JISK7210 (1990) from a viewpoint of a moldability becomes like this. It is preferably 60 g / 10 minutes, and more preferably 2.0 to 40 g / 10 minutes. Moreover, the polyethylene is preferably the density from the viewpoint of heat resistance (JIS K7112) is 0.850~0.980g / cm ^3, more preferably 0.855~0.950g / cm ^3, 0. More preferably, it is 860-0.930 g / cm < ³ >.

  Furthermore, an ethylene / vinyl acetate copolymer (with an ethylene unit content of 50% by weight or less) that can be used as the component (C) is 190 ° C. according to JIS K7210 (1990) from the viewpoint of moldability. The melt flow rate (MFR) measured with a load of 2.16 kg is preferably 1.0 to 60 g / 10 min, and more preferably 2.0 to 40 g / 10 min.

In addition, as a polyolefin of a component (C), 1 type of the polyolefin quoted above may be used, and 2 or more types of polyolefin from which a raw material composition and a physical property differ may be used in combination.

  The polyolefin of component (C) can be obtained as a commercial product. Examples of polypropylene include Novatec (registered trademark) PP series and Wintec (registered trademark) series manufactured by Nippon Polypro Co., Ltd., and appropriate products can be selected and used from these. In addition, examples of polyethylene include Novatec (registered trademark) series manufactured by Nippon Polyethylene Co., Ltd. and Creolex (registered trademark) series manufactured by Asahi Kasei Chemicals Co., Ltd. it can.

[(D) component]
The thermoplastic resin composition of the present invention preferably contains the following component (D) from the viewpoint of assisting the function of the component (B) and improving the easy-openability. In addition, among what can correspond to a polystyrene-type resin, what corresponds to the above-mentioned (B) component shall not be considered as (D) component, but shall be considered as (B) component.
Component (D): a resin obtained by impregnating and polymerizing a polyolefin with a styrene monomer (hereinafter sometimes referred to as “modified polyolefin”) and / or a polystyrene resin.

<Modified polyolefin>
In the present invention, the modified polyolefin is not particularly limited as long as it is a resin obtained by impregnating a polyolefin with a styrene monomer.

  The polyolefin used as the raw material of the modified polyolefin is a homopolymer or copolymer of an olefin having about 2 to 20 carbon atoms such as ethylene, propylene, butene-1, pentene-1, and hexene-1, or copolymerized with these olefins. And a copolymer with an unsaturated vinyl acid such as vinyl acetate, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, maleic anhydride, or an anhydride thereof. In the copolymer of olefin and copolymerizable vinyl monomer, the olefin content is 50% by weight or more. Here, the copolymer includes random, block and graft copolymers. More specifically, high pressure method, medium pressure method or low pressure method polyethylene, polypropylene, ethylene-propylene random copolymer, ethylene-propylene block copolymer, propylene-butene-1 random copolymer, propylene-ethylene-butene- 1 random copolymer, a copolymer composed of propylene and an α-olefin having 5 to 12 carbon atoms and optionally ethylene or butene-1, ethylene-vinyl acetate copolymer, and the like. Among these, polyethylene Polypropylene, ethylene-vinyl acetate copolymer and the like are preferable. These may be used alone or in combination of two or more.

  In the modified polyolefin, the styrene monomer to be impregnated and polymerized in the polyolefin is not particularly limited as long as the aromatic 6-membered ring is directly bonded to the carbon-carbon double bond. More specifically, for example, styrene, methyl Examples thereof include styrene, isopropyl styrene, chlorostyrene, α-methyl styrene, α-ethyl styrene and the like. These styrenic monomers may be used alone or in combination of two or more.

  The amount of the styrene monomer used for the impregnation polymerization is preferably 40 to 95% by weight of polyolefin and 60 to 5% by weight of styrene monomer based on the total weight of polyolefin and styrene monomer. If the amount of the styrene monomer used is too small, the effect as an aggregating and peeling component may not be obtained. On the other hand, if it exceeds 60% by weight, the material strength (flexibility) and moldability of the polyolefin may deteriorate.

The method for impregnating and polymerizing a styrene monomer to polyolefin is not particularly limited, and examples thereof include the following methods. That is, in an aqueous suspension containing 40 to 95% by weight of polyolefin particles (generally having a particle size of 1 to 7 mm, preferably about 2 to 5 mm), 5 to 60% by weight of a styrene monomer, and a radical polymerization initiator, At least 80% by weight of the styrene monomer is impregnated into the polyolefin particles, and then the styrene monomer is polymerized. The details of the polymerization initiator and styrene monomer impregnation method and polymerization method used here are as follows.

(Polymerization initiator)
When a styrene monomer is impregnated into polyolefin particles in an aqueous medium substantially without polymerization thereof, and then this aqueous dispersion is heated to polymerize the styrene monomer, it is usually polymerized with a radical polymerization initiator. To promote. This polymerization initiator needs to be able to be impregnated into the polyolefin particles together with the styrene monomer, and therefore the radical polymerization initiator used is oil-soluble. The polymerization initiator preferably has a decomposition temperature of 50 to 150 ° C. for obtaining a half-life of 10 hours. Here, the “decomposition temperature for obtaining a half-life of 10 hours” means that when 0.1 mol of a polymerization initiator is added to 1 liter of benzene and left at a temperature for 10 hours, the polymerization initiator is decomposed. The temperature at which the rate is 50% is meant. If the impregnation step is carried out at a sufficiently low temperature, a polymerization initiator that can be decomposed at a lower temperature than this can also be used. The polymerization initiator is usually used by dissolving in a styrene monomer.

  Specific examples of radical polymerization initiators include lauroyl peroxide (62 ° C.), benzoyl peroxide (74 ° C.), t-butyl peroxybenzoate (104 ° C.), dicumyl peroxide (117 ° C.) and the like. Examples include azo compounds such as organic peroxides, azobisisobutyronitrile (65 ° C.) and the like (the temperature in the parenthesis is the decomposition temperature for obtaining the above half-life of 10 hours).

  Although there is no restriction | limiting in the usage-amount of a polymerization initiator, Generally it is about 0.01 to 10 weight% of a styrene monomer weight, Preferably it is about 0.1 to 2.0 weight%.

(Impregnation process)
As a typical method of impregnating polyolefin particles with styrene monomer in an aqueous medium, a styrene monomer in which a polymerization initiator (and other additives as required) is preferably dissolved in an aqueous dispersion of polyolefin particles is used. In addition, a method of stirring can be mentioned. As another method, there is a method in which polyolefin particles are added to an aqueous dispersion of a polymerization initiator-dissolved styrene monomer and stirred.

  In the impregnation step, a sufficiently low temperature in correlation with the decomposition temperature of the polymerization initiator used, that is, a temperature condition of about 20 to 100 ° C. is usually employed so that substantially no polymerization occurs.

  In this step, the styrene monomer is usually impregnated so that the amount of free styrene monomer is 80% by weight or less of the total amount of styrene monomer used. The impregnation time is usually about 2 to 8 hours.

  Since polyolefin is relatively compatible with styrenic monomers, even if 80% by weight or more of styrene monomer is liberated before the start of polymerization, these styrene monomers are impregnated into the polyolefin particles during polymerization. The polystyrene particles obtained by polymerizing the monomers do not precipitate separately from the modified polyolefin.

  Further, the content of the polyolefin particles and the styrene monomer in the aqueous dispersion is generally about 5 to 100 parts by weight with respect to 100 parts by weight of water.

Such an aqueous dispersion can be stably maintained in a dispersed state by simply performing sufficient stirring. However, if an appropriate suspension stabilizer is used, the dispersion can be prepared more easily and more stably. it can. As the suspension stabilizer in this case, those that can be used as a suspension stabilizer in the aqueous suspension polymerization of styrene monomer can be generally used, and specifically, polyvinyl alcohol, methylcellulose, hydroxycellulose, etc. Water-soluble polymeric substances, anionic surfactants such as alkylbenzene sulfonates, nonionic surfactants such as polyoxyethylene alkyl ethers, water-insoluble inorganic salts such as magnesium oxide and calcium phosphate, alone or It is mixed and used in an amount of about 0.01 to 10% by weight with respect to water.

  When the polyolefin particles are impregnated with the styrene monomer (and the polymerization initiator), auxiliary materials such as a plasticizer, a lubricant and an antioxidant can be impregnated simultaneously. These auxiliary materials may be already added to the polyolefin, or may be added after polymerization.

(Polymerization process)
The aqueous dispersion prepared as described above is heated and heated to a temperature at which the used polymerization initiator is decomposed at an appropriate rate, whereby the impregnated styrene monomer is polymerized and modified polyolefin particles. Produces. This radical polymerization is carried out in an atmosphere substantially free of oxygen, and the aqueous dispersion during the polymerization is preferably stirred appropriately.

  The polymerization temperature is determined in correlation with the decomposition temperature of the polymerization initiator used, but is generally about 50 to 150 ° C. The polymerization temperature need not be constant throughout the polymerization period. The polymerization time is usually about 2 to 10 hours, and the polymerization pressure is usually about normal pressure to 0.98 MPa.

  In the polymerization step, a chain transfer agent such as n-butyl mercaptan, n-dodecyl mercaptan, or t-dodecyl mercaptan may be present in order to adjust the molecular weight of the modified polyolefin obtained by polymerization of the styrene monomer.

  After the polymerization, if the same treatment as that of the usual aqueous suspension polymerization of styrene monomer is performed, the shape of the polyolefin particles used is maintained almost as it is, and it should be used immediately as a raw material for the thermoplastic resin composition. Can be obtained.

<Polystyrene resin>
In the present invention, the polystyrene-based resin is a resin containing 25% by weight or more of a structural unit represented by the following formula (3), and such a resin may be obtained by homopolymerization. Or obtained by copolymerization.

(In the formula, R represents a hydrogen atom or a methyl group, Z represents a halogen atom or a methyl group, and p is an integer of 0 to 3.)

Examples of the polystyrene resin include polystyrene or a styrene-conjugated diene block copolymer and / or a hydrogenated product thereof (excluding those corresponding to the component (B)). Examples of styrene-conjugated diene block copolymers and / or hydrogenated products thereof include styrene-butadiene block copolymers, styrene-isoprene block copolymers, styrene-butadiene-isoprene block copolymers, and styrene-butadiene blocks. Examples thereof include a hydrogenated product of a copolymer, a hydrogenated product of a styrene-isoprene block copolymer, and a hydrogenated product of a styrene-butadiene-isoprene block copolymer. Polystyrene resins may be used alone or in combination of two or more.

  Polystyrene resins can be obtained as commercial products. For example, as a commercial item of polystyrene resin, PS Japan-made PSJ-polystyrene GPPS series, PSJ-polystyrene HIPS series, etc. are mentioned. Moreover, as a commercial item of a styrene-conjugated diene block copolymer, for example, KRATON (registered trademark) -G series manufactured by Kraton Polymer Co., Ltd., Septon (registered trademark) series manufactured by Kuraray Co., Ltd., Hybra (registered trademark) series, Asahi Kasei Co., Ltd. Applicable products can be selected from Tuftec (registered trademark) series. Commercially available styrene-conjugated diene block copolymers and / or hydrogenated products thereof include Kraton Polymer KRATON (registered trademark) -A series, Kuraray Hybra (registered trademark) series, Asahi Kasei Toughprene (registered) (Trademark) Series and the like can be selected and used.

[Other ingredients]
The thermoplastic resin composition of the present invention may contain other components in addition to the component (A), the component (B), the component (C) and the component (D) used as necessary. . Other ingredients include colorants such as dyes and pigments, stabilizers, plasticizers, antioxidants, UV stabilizers and other light stabilizers, dispersants, thickeners, drying agents, lubricants, antistatic agents, etc. Additives; Fillers such as inorganic fillers and organic fillers; polycarbonate resin, polymethylmethacrylate resin, polyester resin (except those corresponding to (A) component and (C) component), vinyl chloride resin, olefin Thermoplastic elastomers, styrene-based thermoplastic elastomers (excluding those corresponding to the (B) component and (D) component), and polyester-based thermoplastic elastomers (excluding those corresponding to the (A) component and (C) component) are excluded. ) And resins such as polyurethane-based thermoplastic elastomers.

[Blending amount]
The thermoplastic resin composition of the present invention contains (A) component, (B) component, and (C) component, so that the effects of heat seal strength, cohesive peelability (easy-opening property), peel appearance, and moldability are achieved. Can be obtained. From the viewpoint of obtaining these effects satisfactorily, the component (A) is 10 to 90% by weight, the component (B) is 3 to 50% by weight, and the component (C) is the total amount of the components (A) to (C). Is preferably contained in an amount of 5 to 50% by weight, more preferably 15 to 85% by weight of component (A), 4 to 45% by weight of component (B), and 8 to 45% by weight of component (C). .

  When the content ratio of the component (A), which is a component responsible for fusibility, is equal to or higher than the above lower limit value, the heat seal strength tends to be more favorable. (C) It exists in the tendency for peeling appearance, aggregative peeling property, and a moldability to become more favorable because the content rate of a component increases. Further, when the content ratio of the component (B), which is a component responsible for cohesive peelability and good peel appearance, is greater than or equal to the above lower limit value, the cohesive peelability tends to be better, and the peel appearance tends to be better. When the content is below the above upper limit, the content ratio of the component (A) and the component (C) is relatively increased, so that the heat seal strength and the moldability tend to be better. Further, when the content ratio of the component (C), which is a component responsible for formability assistance, is equal to or higher than the lower limit value, the moldability tends to be better, and when it is equal to or lower than the upper limit value, the component (A) When the content ratio of the component (B) is increased, the heat seal strength, peel appearance, and cohesive peelability tend to be better.

Moreover, when the thermoplastic resin composition of this invention contains (D) component, the content is from a viewpoint of easy peelability improvement, Preferably it is with respect to a total of 100 weight part of component (A)-(C). 1 part by weight or more, more preferably 3 parts by weight or more. On the other hand, from the viewpoint of preventing deterioration of the adhesion to the adherend, the content of the component (D) is preferably 30 parts by weight or less with respect to a total of 100 parts by weight of the components (A) to (C). The amount is preferably 20 parts by weight or less.

  In the case where the thermoplastic resin composition of the present invention contains other components other than the components (A) to (D), in order to sufficiently obtain the functions of the components (A) to (C), the thermoplastic resin composition The total content of the other components is preferably 30% by weight or less, more preferably 20% by weight or less, and further preferably 10% by weight or less based on the total thermoplastic resin composition. preferable.

  The method for obtaining the thermoplastic resin composition of the present invention is not particularly limited as long as the raw material components are uniformly dispersed. That is, by mixing the above-described raw material components simultaneously or in any order, a thermoplastic resin composition in which the respective components are uniformly distributed can be obtained. When producing the thermoplastic resin composition of the present invention, the components (A) to (C), the component (D) blended as necessary, and other components are blended to obtain a thermoplastic resin composition. These components are mixed using various known methods such as a tumbler blender, a V blender, a ribbon blender, a Henschel mixer, etc., and then mixed with a single screw extruder, twin screw extruder, Banbury mixer, kneader, etc. A thermoplastic resin composition can be obtained by melt-kneading.

  The mixing method and mixing conditions for mixing the raw material components are not particularly limited as long as the raw material components are uniformly mixed. From the viewpoint of productivity, a single screw extruder or a twin screw extruder is used. A known melt-kneading method such as a continuous kneader and a batch kneader such as a mill roll, a Banbury mixer, and a pressure kneader is preferred. The temperature at the time of melt mixing may be a temperature at which at least one of the raw material components is in a molten state, but usually a temperature at which all the components used are melted is selected, and in the present invention, it is usually performed at 180 to 300 ° C. be able to.

[Film forming]
The thermoplastic resin composition of the present invention can be easily formed as a sealing layer (sealing layer film) by various film forming methods such as extrusion lamination molding, T-die molding, and air-cooled inflation molding. The thickness of the sealing layer film is usually 2 to 100 μm, and preferably 5 to 30 μm. When the thickness of the sealing layer is within the above range, in view of obtaining sufficient heat-sealing strength, in view of obtaining cohesive peelability, in application to an easy-opening lid of an easy-open container, the thickness of the lid Is preferable from the viewpoint of setting the value to an appropriate range.

[Easy-opening lid / Easy-opening container]
By using a sealing layer (film for sealing layer) formed of the thermoplastic resin composition of the present invention, an easily openable lid material can be obtained. Moreover, this easy-open lid | cover material uses the thermoplastic resin composition of this invention as a sealing layer (film for sealing layers), and it is easy to have an easily openable lid | cover material normally by carrying out lamination | stacking integration with the base material. It can be suitably used as an openable container. In this case, a polyolefin resin layer such as polyethylene or polypropylene can be interposed as a holding layer between the seal layer film and the substrate. The thickness of the holding layer is usually about 5 to 500 μm, particularly about 10 to 100 μm.

Examples of the base material of the easy-open lid material include aluminum foil, paper, polyester resin films represented by polyethylene terephthalate, such as stretched polyester film, stretched nylon film, polyethylene, polypropylene, and other olefin resin films, such as stretched polypropylene film. , Polystyrene film, silica-deposited stretched polyester film, aluminum-deposited stretched polyester film, other barrier films, etc. are generally applicable as long as they are used as a base material for flexible packaging materials. A suitable base material can be selected and used.

  Examples of a method for laminating and integrating the sealing layer film made of the thermoplastic resin composition of the present invention on such a substrate include a method of bonding with an adhesive such as polyurethane, polyester, or polyether. Further, the base film and the sealing layer film may be integrally formed by coextrusion lamination.

  In addition, in order to produce a lid member in which a holding layer is interposed between the sealing layer film and the substrate, the thermoplastic resin composition of the present invention is produced by a film molding method such as an inflation method or a T-die method. At the time, after laminating and molding with a holding layer made of a polyolefin resin such as polyethylene and polypropylene, or after laminating the holding layer and the seal layer by coextrusion lamination molding with a polyolefin resin such as polyethylene and polypropylene, Furthermore, a sealing layer and a holding layer are formed on a base material layer made of various thermoplastic resins such as a method of pasting base materials, aluminum foil, paper, polyester resins typified by polyethylene terephthalate, olefin resins such as polyethylene and polypropylene. Examples include a method of manufacturing by forming a laminate film by extrusion lamination molding That.

  The easy-opening lid material made of a laminated film or laminated sheet of the obtained seal layer / base material or seal layer / holding layer / base material is disposed in the opening portions of various containers and along the flange portions of the opening portions. It can be used for sealing a container by heat-pressing and heat-sealing.

  The heat sealing conditions at this time are as follows: the melting point of the component (A) used or a temperature about 50 ° C. higher than the melting point of the component (A), for example, about 110 to 200 ° C., and a pressure of 0.1 to 0 It is preferable that the pressure is about 3 MPa and the heat sealing time is about 1 to 10 seconds.

  The constituent material of the easy-open container to which the easy-open lid using the thermoplastic resin composition of the present invention is applied includes polyethylene resin, polypropylene resin, polyethylene terephthalate resin, polystyrene resin, polycarbonate resin, and blends thereof. Of these, the easy-open container is preferably made of polyethylene terephthalate.

  The easy-opening lid material having the sealing layer formed of the thermoplastic resin composition of the present invention, and the easy-opening container having the easy-opening lid material are any applications that require easy opening of the lid material. However, it can be particularly preferably used in food and beverage containers.

  EXAMPLES The present invention will be described more specifically with reference to the following examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist. The values of various production conditions and evaluation results in the following examples have meanings as preferred values of the upper limit or lower limit in the embodiments of the present invention, and the preferred ranges are the upper limit or lower limit values described above, and It may be a range defined by a combination of values of the examples or values between the examples.

[material]
The raw materials used in the following examples and comparative examples are as follows.

<(A) component>
(A-1)
Byron (registered trademark) GM913 manufactured by Toyobo Co., Ltd.
Low melting crystalline polyester (melting point 135 ° C., glass transition temperature −60 ° C., terephthalic acid / isophthalic acid / 1,4-butanediol / polytetramethylene ether glycol copolymer (dicarboxylic acid unit: 66 mol% terephthalic acid unit, Isophthalic acid unit 34 mol%))

<(B) component>
(B-1)
Dynaron (registered trademark) 4660P made by JSR
Amine-modified styrene-butadiene-styrene hydrogenated block copolymer (styrene content: 10% by weight, MFR (230 ° C., 21.2N (ISO 1133)): 10 g / 10 min, density: 0.89 g / cm ³ , Glass transition temperature: −56 ° C. (ISO 11357-2)), hardness Shore A (ISO 868): 83

<(C) component>
(C-1)
PET-G G6763 manufactured by Eastman Chemical Company
Amorphous polyester (dicarboxylic acid unit: terephthalic acid unit 100 mol%, diol unit: ethylene glycol unit 70 mol%, cyclohexanedimethanol unit 30 mol%)
(C-2)
LDPE Novatec (registered trademark) LC607 made by Nippon Polyethylene
Low density polyethylene (density 0.919 g / cm ³ , MFR (JIS K7210 (1990) (190 ° C., 2.16 kgf)): 8 g / 10 min)

<Component (D)>
(D-1)
Modified polyolefin obtained by impregnating and polymerizing low density polyethylene with styrene (styrene content: 50% by weight)
(D-2)
PS Japan-made PSJ-polystyrene GPPS 679K29
Polystyrene resin (styrene content: 100% by weight)

  In addition, as a PET film used for the production of the evaluation film, “Toyobo Ester (registered trademark) film E5102” (thickness: 25 μm) manufactured by Toyobo Co., Ltd. was used, and as the adhesive, a two-component curable polyurethane manufactured by Toyo Morton Co., Ltd. was used. A base adhesive “TM329” and a curing agent “CAT-8B” diluted with ethyl acetate were used.

[Examples 1-9, Comparative Examples 1-3]
<Film formation of sealant film>
Each component shown in Table-1 is used at a blending ratio shown in Table-1, and is kneaded at 160 to 220 ° C. in a twin-screw extruder “KZW15TWIN-45MG-NH” (manufactured by Technobel Co., Ltd.). Manufactured. In addition, a T-die was used to form a film under the following conditions to form a sealant film having a thickness of 50 μm.
Molding temperature: 220 ° C
Screw rotation speed: 300rpm
Molding speed: 4-5m / min

<Production of evaluation film>
After applying an adhesive to one side of the PET film using a coater (manufactured by Tester Sangyo) and evaporating the solvent, each adhesive film was bonded to the adhesive-coated surface and dried in an oven at 40 ° C overnight. Each was used as an evaluation film.

<Evaluation of heat seal strength>
Each evaluation film and the following adherend were cut into a size of 70 mm × 100 mm, and the evaluation film was placed on the adherend so that the sealant film side was in contact therewith. Heat sealing was performed under the following conditions using a heat sealer (manufactured by Sagawa Seisakusho Co., Ltd.), and the central portion in the length direction of the evaluation film was heat sealed to a width of 10 mm.
Pressure: 0.2MPa
Time: 1.0 seconds Seal bar: 10mm (width)
Temperature: 130 ° C or 160 ° C
Substrate: “Novaclear (registered trademark) SG007” manufactured by Mitsubishi Chemical (A-PET sheet thickness: 0.3 mm)

  Thereafter, the portions of the evaluation film that were not heat-sealed were pulled apart and peeled from each other, and the heat seal strength was measured. The results are shown in Table 1. The heat seal strength is preferably about 4 to 20 N / 15 mm in terms of both easy opening and seal strength.

<Exfoliation appearance>
When measuring the heat seal strength at 160 ° C., the peel appearance was evaluated visually and evaluated according to the following criteria.
○: When peeled, there is no stringing and the appearance is good.
(Triangle | delta): When peeling, a part of sealant layer does not peel from a base material, but stringing is seen.
X: When peeled off, a part of the sealant layer is not completely peeled off from the substrate, and stringing is often observed.

<Evaluation results>
The evaluation results of each example and comparative example are as shown in Table 1 below.

From Table 1, Examples 1 to 9 corresponding to the thermoplastic resin composition of the present invention containing the components (A) to (C) all form a cohesive peelable seal layer excellent in easy-openability and seal strength. I understand that I was able to. On the other hand, since the sealing strength was too strong in Comparative Example 1 in which only component (A) and component (C) were not blended with component (B), the material (film) itself was destroyed and had easy-opening properties. I didn't. In Comparative Example 2 in which only the component (A) and the component (D) were blended and the component (B) and the component (C) were not blended, a film could not be formed. Further, in Comparative Example 3 in which the component (A), the component (C), and the component (D) were blended and the component (B) was not blended, a good peel appearance was not obtained.

Claims (8)

A thermoplastic resin composition comprising the following components (A) to (C).
Component (A): Polyester having a melting peak temperature of 110 to 150 ° C. Component (B): Amine-modified styrenic thermoplastic elastomer (C) Component: Amorphous polyester and / or polyolefin   The total amount of the component (A), the component (B) and the component (C) is 10 to 90% by weight for the component (A), 3 to 50% by weight for the component (B), and 5 to 50 for the component (C). The thermoplastic resin composition according to claim 1, which is contained by weight. (C) The thermoplastic resin composition of Claim 1 or 2 containing the polyethylene of a density of 0.850-0.980g / cm < ³ > as a component.   (C) As a component, it contains 80 mol% or more of terephthalic acid units with respect to all dicarboxylic acid units, and it contains 60 to 80 mol% of ethylene glycol units and 20 to 40 mol% of cyclohexanedimethanol units with respect to all diol units. The thermoplastic resin composition of any one of Claims 1 thru | or 3 containing the amorphous polyester to contain.   The thermoplastic resin composition according to any one of claims 1 to 4, wherein the glass transition temperature (Tg) of the component (A) is -80 to 0 ° C.   An easily-openable container lid member having a seal layer formed of the thermoplastic resin composition according to any one of claims 1 to 5.   An easy-open container having the lid for an easy-open container according to claim 6.   An easy-open container comprising the lid for easy-open containers according to claim 6 and a container made of polyethylene terephthalate resin.