JPH0532800A - Polyester-based resin composition and film having heat sealing property - Google Patents

Abstract

PURPOSE:To provide an useful polyester-based resin composition which is useful to obtain a film having high heat resistance and simultaneously excellent heat seal property. CONSTITUTION:The objective polyester-based resin composition contains (a) modified polybutylene terephthalate and (b) polycarbonate. The modified polybutylene terephthalate is obtained by replacing part of 1,4-butanediol and/or terephthalic acid with other diol and/or dicarboxylic acid. The film having heat-sealing properties includes a single-layer film formed of the above- mentioned resin composition and composite film obtained by laminating at least one substrate layer on either one face of a layer formed of above- mentioned resin composition. The above-mentioned substrate layer may contain a heat resistant resin layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition and a film having heat sealability suitable for various packaging films.

[0002]

2. Description of the Related Art Films having heat-sealing properties are used as various packaging materials, that is, inner layer materials such as pouches for retorts, pillow packages, tubes and the like. As a film having these heat-sealing properties, olefin polymers such as low density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, and ionomer are usually used.
However, when these polymers are used, a polyolefin odor is generated due to low molecular weight hydrocarbons generated during heating such as heat sealing.

As a film which does not generate a polyolefin odor and has a heat-sealing property, for example, nylon 12 film is known. However, a film made of a polyamide resin composition such as nylon tends to have a bitter taste due to monomers and oligomers produced by hydrolysis in a sterilization process such as retort.

On the other hand, a polyethylene terephthalate film is also known as a resin having no polyolefin odor and bitterness. However, if the polyethylene terephthalate film is not stretched to accelerate crystallization,
Softens at a temperature of about ℃. Therefore, although the polyethylene terephthalate film is usually stretched, the heat-sealing property hardly appears in the stretched film. A copolyester in which a part of terephthalic acid constituting polyethylene terephthalate is replaced with isophthalic acid, and a copolyester in which a part of ethylene glycol is replaced with 1,4-cyclohexanedimethanol are also known. However, these resins are inferior in heat sealability, or inferior in heat resistance in the process of sterilization such as retort. As described above, in general, a polymer film having high heat resistance is inferior in heat sealability, and high heat resistance and heat sealability cannot be achieved at the same time. For example, polybutylene terephthalate is also known as a polymer showing high heat resistance without stretching, but a film made of this polymer does not have heat sealability.

Therefore, an object of the present invention is to provide a polyester resin composition useful for obtaining a film exhibiting high heat resistance and heat sealability even though it is a polyester.

Another object of the present invention is to provide a film which is tasteless and odorless even when subjected to heat sealing or heat treatment and which is excellent in heat sealability and heat resistance.

Still another object of the present invention is to provide a film excellent in mechanical strength, heat resistance and heat sealability even if it is not stretched.

[0008]

In order to achieve the above object, the present inventor has
As a result of diligent study on the polyester resin composition, a film produced using a resin composition containing a modified polyalkylene terephthalate and a polycarbonate was found to have excellent heat sealability and heat resistance, and the present invention was completed. .

That is, the present invention comprises (a) at least one diol component selected from aliphatic diols, alicyclic diols and aromatic diols, and terephthalic acid or two or more dicarboxylic acids containing at least terephthalic acid. A polyester resin composition comprising a copolyester derived from the following dicarboxylic acid component and (b) a polycarbonate.

When the dicarboxylic acid component is terephthalic acid, the diol component is not an aliphatic diol, an alicyclic diol or an aromatic diol alone.

The present invention also provides, as a film having heat sealability, a film formed of the above polyester resin composition; at least one group is formed on one surface of a layer formed of the above polyester resin composition. A film in which a material layer is laminated; and a film in which the base material layer includes at least a heat resistant resin layer.

In the present specification, the term "aromatic diol" means not only a compound in which a hydroxy group is directly bonded to an aromatic ring but also an alkylene group or an alkylenedioxy group in the aromatic ring. It is used to include a compound indirectly bound to a hydroxy group.

Unless otherwise specified, the term "terephthalic acid", "dicarboxylic acid" and "dicarboxylic acid component" are used for esterification reaction such as lower alkyl ester, acid anhydride and acid halide. It is also used to include a commonly used derivative of carboxylic acid.

The term "film" is used to include substantially all flat structures sometimes referred to as sheets by those skilled in the art.

"Melting point" means a differential scanning calorimeter (DS)
C) means the melting peak temperature (T _pm ) when measured at a temperature rising rate of 10 ± 1 ° C./min according to the measuring method specified in JIS K 7121.

As the diol component constituting the copolyester (a), conventional aliphatic, alicyclic and aromatic diols are used.

Examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butanediol and 1,4-butanediol. , Neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, polymethylene glycol and the like.

Examples of the alicyclic diol include 1,4
-Cyclohexanediol, 1,4-cyclohexanedimethanol, 2,2-bis (4-hydroxyethoxycyclohexyl) propane, hydrogenated bisphenol A
And an alkylene oxide such as ethylene oxide or propylene oxide.

As the aromatic diol, for example, resorcinol, naphthalene diol, 2,2-bis (4-hydroxyphenyl) propane, bisphenol A and an adduct of alkylene oxide such as ethylene oxide or propylene oxide, for example, 2 , 2-bis (4
-Hydroxyethoxyphenyl) propane, 2,2-bis (4-hydroxydiethoxyphenyl) propane,
2,2-bis (4-hydroxytriethoxyphenyl)
Propane, 2,2-bis (4-hydroxypolyethoxyphenyl) propane, 2,2-bis (4-hydroxypropoxyphenyl) propane, 2,2-bis (4-hydroxydipropoxyphenyl) propane, 2,2- Bis (4-hydroxytripropoxyphenyl) propane,
2,2-bis (4-hydroxypolypropoxyphenyl) propane and the like are exemplified.

As the diol component, the same or different diols can be used alone or in combination of two or more.

The dicarboxylic acid component is composed of terephthalic acid; two or more dicarboxylic acids containing at least terephthalic acid. Preferred derivatives of terephthalic acid include terephthalic acid methyl ester.

Examples of the dicarboxylic acid which can be used in combination with the terephthalic acid include aliphatic dicarboxylic acids such as maleic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid and dodecanoic acid; 1,4-cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acids such as acids; phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, aromatic dicarboxylic acids such as 3-sulfoisophthalic acid, and the like. . These other dicarboxylic acids can be used alone or in combination of two or more.

At least one of the diol component and the dicarboxylic acid component is composed of two or more kinds of diol and / or dicarboxylic acid in order to form a modified polyester. That is, when the (1) diol component is a single diol, two or more dicarboxylic acids containing at least terephthalic acid are used as the dicarboxylic acid component. In this case, the diol component is preferably an aliphatic diol. On the other hand, when the diol component (2) is two or more diols, terephthalic acid alone or two or more dicarboxylic acids containing at least terephthalic acid are used as the dicarboxylic acid component. In this case, the diol component preferably contains at least an aliphatic diol.

In the above embodiments (1) and (2), a particularly preferable diol component among the aliphatic diols is 1,4-butanediol alone or at least 1,4-butanediol from the viewpoint of heat resistance in the sterilization process such as retort. Two or more kinds of diols containing 1,4-butanediol as an essential component.
Examples of the diol capable of substituting a part of 1,4-butanediol include (a) an aliphatic diol containing at least diethylene glycol, particularly (a1) diethylene glycol, (a2) ethylene glycol and diethylene glycol, and (b) the following general formula: The aromatic diol represented by [II] is preferable.

[0025]

[Chemical 2] (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are the same or different and each represents a hydrogen atom or a methyl group, and l and m represent a positive integer.) Aroma represented by the general formula [II] In the group diol, l and m are integers of 1 to 10, preferably 1 to 5. Among the aromatic diols represented by the general formula [II], 2,2-bis (4-hydroxyethoxyphenyl) propane and 2,2-bis (4-hydroxydiethoxyphenyl) propane are particularly preferable.

The copolyester which does not contain 1,4-butanediol as a constituent monomer has a small crystallinity at the time of film formation, and its heat resistance is likely to decrease.

In the above embodiments (1) and (2), as the dicarboxylic acid that can be substituted for a part of terephthalic acid, for example, isophthalic acid is preferable.

The copolyester can be obtained by using an diol component and a dicarboxylic acid component in substantially equimolar amounts and subjecting them to an esterification reaction. In the embodiments of (1) and (2), the molar ratio of a plurality of diols constituting the diol component,
The molar ratio of the plurality of dicarboxylic acids constituting the dicarboxylic acid component can be selected according to the types of the diol and the dicarboxylic acid, the desired heat sealing temperature and the like.

In the embodiment (1), the preferred copolyester is 50 mol% of aliphatic diol and terephthalic acid / other dicarboxylic acid = 5-95 / 95-5 (molar ratio), preferably 10-75 / 90-25 (molar ratio),
More preferably, it is a copolyester with 50 mol% of a dicarboxylic acid component in a ratio of 20 to 50/80 to 50 (molar ratio). More specifically, when the copolyester is a copolyester of 1,4-butanediol and terephthalic acid / isophthalic acid, terephthalic acid / isophthalic acid = 15 to 90/85 to 10 (molar ratio),
Particularly, it is preferably about 20 to 50/80 to 50 (molar ratio).

In the above embodiment (2), the preferred copolyester is aliphatic diol / other diol = 2.
5 to 95/75 to 5 (molar ratio), preferably 50 to 90
/ 50 to 10 (molar ratio), more preferably 70 to 90
It is a copolyester of 50 mol% of diol component consisting of / 30 to 10 (molar ratio) and 50 mol% of terephthalic acid. More specifically, the copolyester comprises terephthalic acid, 1,4-butanediol and 2,2-bis (4
In the case of a copolyester with -hydroxyethoxyphenyl) propane, 1,4-butanediol / 2,
2-bis (4-hydroxyethoxyphenyl) propane = 60-95 / 40-5 (molar ratio), especially 70-90 /
It is preferably about 30 to 10 (molar ratio).

Regarding the heat sealability, the melting point of the copolyester is also important. That is, in the relationship between the heat-sealing temperature and the heat-sealing strength, the temperature at which the heat-sealing strength is developed mainly depends largely on the melting point of the copolyester. The melting point of the copolyester is preferably in the range 150-210 ° C. The melting point of copolyester is 15
When the temperature is lower than 0 ° C, the films are likely to block each other in a heat sterilization process such as retort, and when the temperature is higher than 210 ° C, heat sealing under normal conditions becomes difficult and the bag-making speed decreases. The film formed of the resin composition containing the copolyester having the above melting point can be heat-sealed by a general bag-making device.

The copolyester may have an appropriate molecular weight within a range that does not impair the moldability and mechanical strength. The weight average molecular weight of the copolyester is usually 500.
0 to 1,000,000, preferably 10,000 to 500
It is about 000.

The intrinsic viscosity of the copolyester has a temperature of 25 ±
When the solvent o-chlorophenol is used at 1 ° C, at least about 0.5 dl / g or more, preferably 0.5 to 2.5.
It is about dl / g.

The method for producing the copolyester is not particularly limited and can be carried out by a conventional method such as a transesterification method or a direct esterification method.

In any of these methods, the molecular weight may be increased by using a solid phase polymerization method after the polymerization reaction, if necessary. In particular, it is preferable to use the solid phase polymerization method in order to secure the necessary viscosity during film formation.

Polycarbonate has the following general formula [III]:
Including the repeating unit represented by.

[0037]

[Chemical 3] (In the formula, R ₅ represents a divalent organic group, and n represents an integer of 10 or more.) When R ₅ is an alkylene group, it is an aliphatic polycarbonate, and R ₅ is an aliphatic group containing an aromatic ring. In some cases, it is an aromatic-aliphatic polycarbonate, and when R ₅ is an arylene group, it is an aromatic polycarbonate.

Of the above polycarbonates, the resin composition of the present invention preferably contains a polycarbonate having a repeating unit represented by the following general formula [IV].

[0039]

[Chemical 4] (In the formula, R ₆ and R ₇ represent a halogen atom, a phenylene group which may be substituted with an alkyl group or a cycloalkylene group. X and Y are the same or different and each is a hydrogen atom or a fatty acid having 12 or less carbon atoms. shows the family hydrocarbon group, may form a cycloalkane group together with the carbon atom adjacent to the R6 and R _7. However, R ₆ and R _7, X, aliphatic hydrocarbon group for Y may include an unsaturated bond (Not included) polycarbonate is not limited to a linear chain, and includes a branched polycarbonate in which the above repeating unit is branched from the main chain.

A preferred polycarbonate is a bisphenol type polycarbonate having a repeating unit represented by the following general formula [V], particularly 2,2-bis (4-hydroxy) having a repeating unit represented by the following formula [VI]. Phenyl)
It is a bisphenol A type polycarbonate using propane as a starting material.

[0041]

[Chemical 5] (In the formula, R ₈ and R ₉ are the same or different and each represents a hydrogen atom, a lower alkyl group, a cycloalkyl group or an aryl group.)

[0042]

[Chemical 6] Examples of the lower alkyl group in the repeating unit represented by the general formula [V] include an alkyl group having about 1 to 4 carbon atoms. Cycloalkyl groups include, for example, cyclopentyl,
Includes cyclohexyl, cyclooctyl groups and the like. The aryl group includes a phenyl group and a naphthyl group.

The terminal group of the polycarbonate may be an OH group or may be blocked with a substituent such as a t-butyl group.

The intrinsic viscosity of polycarbonate is 20
0.3-1.0d when using methylene chloride at ± 1 ° C
It is preferably about 1 / g, particularly about 0.5 to 0.7 dl / g.

The molecular weight of the polycarbonate can be selected according to the molecular weight of the copolyester. That is, when the melt viscosities of the copolyester and the polycarbonate at the same temperature are greatly different, a uniform melt mixture may not be obtained and dispersion may be poor. Therefore, it is preferable to select the molecular weight of the polycarbonate so as to match or approximate the melt viscosity of the copolyester and the polycarbonate.

When the copolyester and the polycarbonate are once melt-mixed to prepare a masterbatch having a uniform composition and subjected to extrusion molding, there is a difference in melt viscosity (melt flow rate) between them at the same temperature. , Polycarbonate / copolyester = 1/75, a uniform film can be obtained.

The method for producing the polycarbonate is not particularly limited, and a conventionally used method such as a phosgene method (solvent method) or a transesterification method (melting method) can be employed.

In the present invention, the first purpose of adding the polycarbonate (b) to the copolyester (a) is to alleviate the dependence of the heat seal strength on the heat seal temperature. More specifically, a modified copolyester whose expression of heat seal strength strongly depends on the heat seal temperature, for example, a modified polybutylene terephthalate in which a part of terephthalic acid is replaced with isophthalic acid will be described as follows. .

This copolyester alone exhibits heat-sealing strength only at a high temperature, and shows substantially no heat-sealing strength at a temperature lower than the heat-sealable temperature. As described above, the heat seal strength has a strong dependency on the heat seal temperature and the temperature range in which the heat seal can be performed is narrow. Therefore, in the actual heat seal work, a seal defect is likely to occur.

On the other hand, when the polycarbonate is contained, the heat-sealing strength is exhibited even if the heat-sealing is performed at a temperature not higher than the heat-sealing strength of the copolyester. Therefore, it is possible to shift the heat-sealing temperature to the low temperature side, and it is possible to exhibit high heat-sealing strength in a wide temperature range. It is presumed that this is because the addition of polycarbonate to the copolyester reduces the crystallinity and crystallization rate of the copolyester.

The second purpose of adding polycarbonate to the copolyester is to prevent whitening of the heat-sealed portion. More specifically, the polybutylene terephthalate and the modified copolyester, in which the whitening of the heat-sealed portion remarkably appears, will be described as follows.

In general, polybutylene terephthalate is not only easy to crystallize, but also has a high crystallization rate and crystallinity. Further, since the modified copolyester is modified by copolymerization, rather than polybutylene terephthalate,
The crystallization rate and crystallinity are low, but still high. Therefore, when the copolyester is used alone, there is a phenomenon that crystallization excessively progresses in the slow cooling process after heat sealing and the heat sealed portion is whitened. The whitening phenomenon reduces the commercial value of the bag-made product.

On the other hand, when polycarbonate is added to the modified copolyester, the heat-sealed portion does not whiten.
The above effect is remarkable in the bisphenol type polycarbonate containing the repeating unit represented by the general formula [V], particularly the formula [VI]. It is presumed that this is because when the polycarbonate is added to the modified copolyester, the crystallization rate is slow and the crystallinity is small as described above.

The ratio of the copolyester and the polycarbonate can be selected according to the types of the copolyester and the polycarbonate within a range that does not impair the above-mentioned characteristics. For example, copolyester / polycarbonate = 50 to 90/50.
10 (wt%), preferably 70-90 / 40-10
(% By weight). The content of polycarbonate is 5
If it exceeds 0% by weight, the heat-sealing property and mechanical strength may decrease depending on the type of polycarbonate, and if it is less than 10% by weight, whitening is likely to occur at the heat-sealed portion.

The resin composition of the present invention may contain various additives within the range not impairing the above-mentioned properties and heat sealability. Examples of the additives include antioxidants, ultraviolet absorbers, heat stabilizers, plasticizers, antistatic agents, tackifiers, fillers, waxes, lubricants, dyes and pigments. These additives may be used alone or in combination of two or more. From the viewpoint of mechanical suitability at the time of film formation, it is preferable to add a lubricant and a heat stabilizer. As the lubricant, fine silica powder having an average particle size of about 1 to 10 μm is particularly preferable. The content of the silica fine powder is, for example, about 0.1 to 0.5% by weight.

The resin composition of the present invention is a conventional molding material,
Although it can be used as a fiber-reinforced composite material, it is suitable as a film-forming material.

The heat-sealable film of the present invention comprises (i) a single layer film formed of the polyester resin composition, and (ii) one surface of a layer formed of the polyester resin composition. , And a composite film in which at least one base material layer is laminated. The laminated form of the composite film is not particularly limited as long as the layer formed of the polyester resin composition is located on at least one surface.

In the latter composite film, the base material layer includes paper; a metal thin film such as an aluminum thin film; and a polymer layer. Examples of the polymer constituting the polymer layer include polyethylene, ethylene-ethyl acrylate copolymer, ionomer, polypropylene, ethylene-propylene copolymer, poly-4-methylpentene-1.
Such as olefin polymers; ethylene-vinyl alcohol copolymers; polyvinyl chloride; vinylidene chloride-acrylic acid ester copolymers, vinylidene chloride-vinyl chloride copolymers, vinylidene chloride-acrylonitrile copolymers, and other vinylidene chloride polymers Styrene-based polymers such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, and haint impact polystyrene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; nylon or polyamide; polyacrylonitrile;
Polycarbonate; polyimide; cellophane and the like. Of these polymers, olefin polymers (particularly polypropylene), polyester and nylon are preferred.

The metal thin film may be formed by a film forming means such as vapor deposition or lamination, and the polymer layer may be formed by coating or lamination. The polymer layer may be further coated with the vinylidene chloride polymer, or a metal thin film may be formed by means such as vapor deposition.
The polymer layer may be unstretched or may be uniaxially or biaxially stretched. Further, the polymer layer may be composed of a plurality of layers made of the same or different polymers.

In the composite film (ii), the base material layer preferably contains at least a heat resistant resin layer in order to further improve heat resistance, mechanical strength, gas barrier properties and the like. As the heat resistant resin, for example, nylon-6,
Nylon such as nylon-66, polyamide such as aromatic polyamide; polyacetal; polycarbonate; polyphenylene oxide; polyester such as polyethylene terephthalate, polybutylene terephthalate and polyester type liquid crystalline polymer; polyphenylene sulfide; polysulfone; polyarylate; polyether sal Phone; polyetheretherketone; polyamideimide; polyetherimide; aromatic polyimide and the like. At least one of these heat resistant resins is used.

Among these heat resistant resins, polycarbonate, polyester, polyarylate and the like can be laminated with the layer made of the above polyester resin composition by coextrusion molding.

Further, among the heat resistant resins, the melting point is 2
Polymers having a temperature of 00 ° C. or higher, particularly polyesters, especially polybutylene terephthalate are preferable. This polybutylene terephthalate may have a molecular weight within a range that does not impair moldability and mechanical strength. The weight average molecular weight of polybutylene terephthalate is usually 5,000 to 1,000.
000, preferably about 10,000 to 500,000. The intrinsic viscosity of polybutylene terephthalate is
When the solvent o-chlorophenol is used at a temperature of 25 ± 1 ° C., it is at least about 0.5 dl / g or more, preferably 0.1.
It is about 5 to 2.5 dl / g.

The polybutylene terephthalate film not only has a crystal-like luster and has a good appearance, but also has excellent heat resistance and mechanical strength, gas barrier properties against oxygen gas and water vapor, aroma retention and oil resistance. So
When used as a packaging film by laminating it with a layer formed of the polyester resin composition, the content is excellent in protection.

The layer thickness of the heat resistant resin layer can be appropriately set, but is usually 10 to 1000 μm, preferably 15 to 500.
It is about μm.

The heat-resistant resin layer may contain a small amount of the resin composition as long as the characteristics are not impaired. That is, when the heat-resistant resin layer and the layer formed of the resin composition are laminated by the coextrusion molding method, the ends of the composite film may be recovered, pelletized again, and then subjected to extrusion molding. In this case, the regenerated pellets can be added to the heat resistant resin and extruded. The amount of recycled pellets added to the heat resistant resin is 30% by weight.
Hereafter, it is preferably 20% by weight or less. The regenerated pellets may be used as an intermediate layer material between the heat resistant resin layer and the layer formed of the resin composition.

The heat resistant resin layer may be laminated directly on the layer formed of the resin composition, or may be laminated via a polymer layer other than the heat resistant resin. Each layer may be laminated via an adhesive or an adhesive resin layer as needed.

Another preferred composite film of the composite film (ii) is that the base material layer comprises a heat-resistant resin layer, an olefin polymer such as polypropylene, a polyester such as polyethylene terephthalate, and a nylon system such as nylon 6. And a polymer layer selected from polymers. In the laminated form of this composite film, a polymer layer and a layer formed of the resin composition may be laminated via a heat-resistant resin layer, and the heat-resistant resin layer and the layer may be laminated via a polymer layer. It may be laminated with a layer formed of a resin composition. The preferred laminated form is the former. Further, in these laminated forms, usually, the polymer layer does not necessarily have to be stretched because it is possible to secure high mechanical strength by the heat resistant resin layer, but in order to further increase the mechanical strength, the polymer layer is It is preferably uniaxially stretched, preferably biaxially stretched.

The base material layer can be formed to an appropriate thickness depending on the intended use of the film, and is, for example, about 5 μm to 2 mm, preferably about 15 μm to 1 mm.

The base material layer may contain a polymer and the above-mentioned additives. As the polymer, for example,
Olefin polymer; Acrylic polymer; Styrene polymer; Polyester; Polyacetal; Polyvinyl acetate; Polyvinyl chloride; Vinylidene chloride polymer;
Examples include chlorinated polyolefins; cellulosic polymers; vinyl chloride-vinyl acetate copolymers and the like. These polymers are used alone or in combination of two or more. These polymers are used within a range that does not impair heat resistance and the like. In particular, depending on the type of the olefin-based polymer, when a large amount of the olefin-based polymer is contained in the polymer, heat resistance and transparency may be impaired.

The heat-sealable monolayer film of the present invention can be produced by a conventional method, for example, an ordinary extrusion molding method such as a T-die method or an inflation method using an extrusion molding machine. In addition, the composite film is formed by a conventional method, for example, a coextrusion molding method of laminating with a coextrusion molding machine; an extrusion method of forming a laminated layer by extruding a molten resin composition onto a base material film forming a base material layer. Laminating method: It can be manufactured by a dry laminating method or the like in which a base film and a heat-sealing layer are laminated via an adhesive layer. According to the coextrusion molding method, the productivity of the composite film is high.

Various methods can be adopted in the coextrusion molding method for producing a composite film using a plurality of polymers. For example, a feed block system in which each resin layer is merged on the upstream side of a die having a single flow channel; a multi-manifold die in which a plurality of different flow channels are provided in the die and they are merged and discharged before discharge in the die. Examples of the method include a multi-manifold die method, a vane die method capable of changing the shape of a flow path, and a multi-slot method in which a plurality of lips are provided in a discharge portion of the die. The interlayer adhesive strength between the base material layer and the heat seal layer formed of the resin composition is increased as the time during which the base material layer and the heat seal layer are in contact with each other in a molten state is longer. Therefore, it is preferable to manufacture the composite film by the feed block method. When manufacturing a composite film by other methods such as multi-manifold die method and multi-slot method,
An interlayer adhesive layer is preferably provided between the base material layer and the heat seal layer.

The method for preparing the resin composition used for film formation is not particularly limited, and a conventional method,
For example, a method generally called a dry blend method or a method called a masterbatch method can be adopted. The dry blending method is a method in which pellets of the copolyester (a) and the polycarbonate (b) are mixed. The obtained mixture is directly subjected to the film forming step. On the other hand, the masterbatch method is a method in which pellets of the copolyester (a) and the polycarbonate (b) are melt-mixed in advance to prepare pellets having a uniform composition.

The raw material resin composition is preferably prepared by a masterbatch method. That is, according to the knowledge of the present inventor, when a raw material resin composition was prepared by the masterbatch method and analyzed by ¹³ C-NMR and ¹ H-NMR, a transesterification reaction with about 40 to 60% of polycarbonate (b) was observed. Seems to have occurred. From this, it is presumed that the polycarbonate (b) forms a block copolymer with the copolyester (a). Also,
As described above, it is presumed that this transesterification reaction contributes to the development of the heat-sealing strength at the heat-sealing temperature lower than the original heat-sealing temperature of the copolyester.

When an extruder that is expected to have a sufficient melt-kneading effect is used, a dry blend method may be used. Examples of such an extruder include a twin-screw extruder and a tandem extruder in which two or more extruders are connected. Also, even with a single-screw extruder,
If the extruder has a large L / D (ratio of the length L of the barrel of the extruder to the diameter D), the melt-kneading effect can be obtained. In this case, it is preferable to provide a mudock at the tip of the screw used.

Since the film of the present invention exhibits high mechanical strength even in the unstretched state, the stretching process is not always necessary, but the entire film may be uniaxially or biaxially stretched, if necessary.

The surface of the film of the present invention may be subjected to surface treatment such as corona discharge treatment, high frequency treatment, flame treatment, chromic acid treatment, and solvent treatment. In particular, the corona discharge treatment is preferable because it improves the dry lamination strength between the heat-sealing film of the present invention and the base film.

Further, a coating layer such as a gas barrier layer, an antistatic layer or a slipping layer may be formed on the surface of the film, depending on the intended use.

The heat-sealing temperature can be appropriately set depending on the melting point of the copolyester (a) and the content of the polycarbonate (b), but is usually 120 ° C. or higher, preferably about 130 to 220 ° C. Heat seal temperature is 2
If it exceeds 20 ° C., the base material layer may be heat-shrinked in the composite film in which the base material layer is stretched.

The films of the present invention have a wide range of applications, for example:
It can be used as various films such as individual packaging for retort foods, packaging films for interiors and exteriors, and the like.

[0080]

The polyester resin composition of the present invention is
Despite being polyester, it is useful for obtaining a film having high heat resistance and heat sealability.

The heat-sealing film of the present invention is tasteless and odorless and has excellent heat-sealing property and heat resistance.

Further, the composite film including the layer formed of the polyester resin composition is excellent in mechanical strength, heat resistance and heat sealability even if the base material layer is not stretched.

[0083]

EXAMPLES The present invention will be described in more detail based on the following examples.

Example 1 50 mol% of dicarboxylic acid having a ratio of terephthalic acid / isophthalic acid = 87.5 / 12.5 (molar ratio);
Copolyester 80 with 4-butanediol 50 mol%
Parts by weight, and bisphenol A type polycarbonate 2
0 parts by weight was melt-mixed in advance to obtain a masterbatch having a uniform composition. This masterbatch was molded by an ordinary T-die extrusion molding machine to obtain a monolayer film having a thickness of 40 μm.

Example 2 50 mol% of dicarboxylic acid having a ratio of terephthalic acid / isophthalic acid = 34.3 / 65.7 (molar ratio)
Copolyester 80 with 4-butanediol 50 mol%
Parts by weight, and bisphenol A type polycarbonate 2
Dry blend 0 parts by weight of pellets, L / D = 28
Was extruded by a single-screw extruder and then molded by an ordinary T-die extrusion molding machine to obtain a monolayer film having a thickness of 40 μm.

Example 3 50 mol% of dicarboxylic acid consisting of terephthalic acid / isophthalic acid = 30.0 / 70.0 (molar ratio)
Copolyester 80 with 4-butanediol 50 mol%
Parts by weight, and bisphenol A type polycarbonate 2
0 parts by weight of the pellets were mixed, and an extruder having a diameter of 32 mm and an extruder having a diameter of 40 mm were connected and extruded and molded by a T-die extrusion molding machine to obtain a single-layer film having a thickness of 40 μm.

Example 4 50 mol% of dicarboxylic acid consisting of terephthalic acid / isophthalic acid = 80.0 / 20.0 (molar ratio)
Copolyester 80 with 4-butanediol 50 mol%
Parts by weight, and bisphenol A type polycarbonate 2
A thickness of 4 was obtained in the same manner as in Example 1 except that 0 part by weight was used.
A 0 μm monolayer film was obtained.

Example 5 50 mol% of terephthalic acid and 1,4-butanediol /
2,2-bis (4-hydroxyethoxyphenyl) propane = diol 10 consisting of 90/10 (molar ratio)
A single-layer film having a thickness of 40 μm was obtained in the same manner as in Example 1 except that 80 parts by weight of 0% by mole of copolyester and 20 parts by weight of bisphenol A-type polycarbonate were used.

Example 6 70 parts by weight of the copolyester of Example 2 and 30 parts by weight of bisphenol A type polycarbonate were used,
A monolayer film having a thickness of 40 μm was obtained in the same manner as in Example 1.

Example 7 90 parts by weight of the copolyester of Example 2 and 10 parts by weight of bisphenol A type polycarbonate were used,
A monolayer film having a thickness of 40 μm was obtained in the same manner as in Example 1.

Example 8 Using 60 parts by weight of the copolyester of Example 2 and 40 parts by weight of bisphenol A type polycarbonate,
A monolayer film having a thickness of 40 μm was obtained in the same manner as in Example 1.

Comparative Example 1 50 mol% of 1,4-butanediol and 50 terephthalic acid
The polybutylene terephthalate obtained from 1 mol% was melt-mixed in advance to obtain a masterbatch. Example 1 without the addition of polycarbonate to this masterbatch
A single-layer film having a thickness of 40 μm was obtained in the same manner as in.

Comparative Example 2 A single layer film having a thickness of 40 μm was obtained in the same manner as in Example 1 without adding polycarbonate to the copolyester of Example 1.

Comparative Example 3 A monolayer film having a thickness of 40 μm was obtained in the same manner as in Example 1 except that 80 parts by weight of polybutylene terephthalate of Comparative Example 1 and 20 parts by weight of the polycarbonate used in Example 1 were used.

Comparative Example 4 A film thickness of 40 was obtained in the same manner as in Example 1 without adding polycarbonate to the copolyester obtained in Example 5.
A μm monolayer film was obtained.

Comparative Example 5 A copolyester of 50 mol% terephthalic acid and 50 mol% diol consisting of diethylene glycol / ethylene glycol = 40/60 (molar ratio) was obtained. The melting point of the obtained copolyester was 177 ° C. The copolyester was molded in the same manner as in Example 1 to obtain a monolayer film having a thickness of 40 μm.

Comparative Example 6 A copolyester of 50 mol% of ethylene glycol and 50 mol% of a dicarboxylic acid having a ratio of terephthalic acid / isophthalic acid = 55/45 (molar ratio) was obtained. The melting point of the obtained copolyester was 220 ° C. The copolyester was molded in the same manner as in Example 1 to obtain a monolayer film having a thickness of 40 μm.

Comparative Example 7 A copolyester of 50 mol% of ethylene glycol diol and 50 mol% of dicarboxylic acid having a ratio of terephthalic acid / isophthalic acid = 32/68 (molar ratio) was obtained. The melting point of the obtained copolyester was 190 ° C. A copolyester was molded in the same manner as in Example 1 to give a film thickness of 40.
A μm monolayer film was obtained.

Comparative Example 8 Diol 5 consisting of ethylene glycol / 1,4-cyclohexanedimethanol = 41/59 (molar ratio)
A copolyester of 0 mol% and 50 mol% terephthalic acid was obtained. The melting point of the obtained copolyester was 228 ° C.

The copolyester was molded in the same manner as in Example 1 to obtain a monolayer film having a thickness of 40 μm.

The heat-sealing properties, heat resistance and elongation at break of the monolayer films or composite films obtained in Examples 1 to 8 and Comparative Examples 1 to 8 were measured as follows. The melting point was measured for the copolyester (a).

Heat-sealing property: The films obtained in Examples 1 to 8 and Comparative Examples 1 to 8 and the stretched polyethylene terephthalate film (film thickness 12 μm) were bonded together using an isocyanate type dry laminating agent, Heat sealing was performed from the polyethylene terephthalate film side of the obtained composite film.

The heat-sealing conditions are temperature 4 levels (140
℃, 160 ℃, 180 ℃, 200 ℃), pressure 1kg / c
m ² , time 1 second. The heat seal strength was measured under conditions of a peeling speed of 300 mm / min and a peeling width of 15 mm. The number of measurement points was 20 (10 points in the machine direction, 10 points in the direction perpendicular to the machine direction), and the maximum value until breakage in each measurement was taken as the heat seal strength, and the average value was calculated.
The measurement conditions were based on JIS Z1707.

Heat resistance: A sample film was placed in a hot air dryer and heat-treated at a temperature of 120 ° C. for 30 minutes, and the change in haze value before and after heat treatment was measured according to JIS 7105. The whitening degree was visually determined according to the following criteria.

Excellent: Almost no change was observed. Good: Slight change was observed, but there was no problem in practical use. Poor: There was a large whitening degree and there was a practical problem. Elongation: Based on JIS Z1707. However, the pulling speed was 100 mm / min. Sample shape is JI
According to S Z1702.

Tables 1 and 2 show the composition of the heat seal layer in the films of Examples and Comparative Examples. Further, Tables 3 and 4 show the measurement results of the melting points of the copolyesters used in Examples 1 to 8 and Comparative Examples 1 to 8, the heat sealability of each film, the heat resistance, and the elongation at break.

In Tables 1 and 2, BD is 1,4-butanediol, HPP is 2,2-bis (4-hydroxyethoxyphenyl) propane, DEG is diethylene glycol, EG is ethylene glycol, and CHDM is 1. Four
-Cyclohexanedimethanol, TFA means terephthalic acid, IFA means isophthalic acid.

In the term of elongation at break, MD represents strength in the machine direction and TD represents strength in the direction perpendicular to the machine direction.

Further, a correlation diagram of heat seal temperature dependency of heat seal strength in Example 1 and Comparative Example 2 is shown in the figure.

[0110]

[Table 1]

[0111]

[Table 2]

[0112]

[Table 3]

[0113]

[Table 4] As is clear from Tables 3 and 4, films having heat-sealing properties other than those in Examples are inferior in heat resistance, and films excellent in heat resistance are inferior in heat-sealing property. The film of the comparative example also has a large whitening degree as a whole.

Example 9 Ethylene vinyl acetate copolymer graft-copolymerized with a resin composition similar to that in Example 2, linear low-density polyethylene (LLDPE), and an adhesive resin layer, and maleic anhydride was graft-copolymerized. Was subjected to coextrusion molding of 3 layers of 3 types using a multi-manifold type inflation method. The layer structure of the obtained composite film was LLDPE / adhesive resin layer / heat seal layer = 80 μm / 10 μm / 20 μm, and the total film thickness was 100 to 110 μm.

Comparative Example 9 As a comparative example corresponding to Example 9, a linear low-density polyethylene (LLDPE) was subjected to extrusion molding using a normal T-die extruder to obtain a single layer film having a thickness of 100 to 110 μm. Got

Using the multilayer film obtained in Example 9 and the LLDPE single layer film obtained in Comparative Example 9, a multilayer film generally suitable as a laminate tube was produced as follows.

The films obtained in Example 9 and Comparative Example 9 were extrusion-laminated with aluminum (Al, 9 μm) via an ethylene-ethyl acrylate copolymer (EEA).

On this film, thin paper (50 g / m ² )
Was extruded and laminated through EEA, and then the film obtained in Example 9 or Comparative Example 9 was dry laminated on the outer surface.

The layer structure of the obtained film was such that in the composite film using the film of Example 9, (inner layer side) heat seal layer / adhesive resin layer / LLDPE / EEA / Al /
EEA / thin paper / dry laminate layer / LLDPE / adhesive resin layer / heat seal layer (outer layer side), Comparative Example 9
In the composite film using the above film, (inner layer side) LL
DPE / EEA / Al / EEA / thin paper / dry laminate layer / LLDPE (outer layer side). The total thickness of the multilayer film for a laminated tube was 350 to 380 μm.

The obtained multilayer film was slit into a width of 100 mm, rolled into a cylindrical shape, and ultrasonically sealed at the ends. Ultrasonic sealing is 500 W, sealing time 0.5 seconds, pressure 2
It was carried out under the condition of kg / cm ² . The width of the seal part is 10m
m. A mouthpiece was attached to one open end of this cylindrical tube, and the other open end was ultrasonically sealed in the same manner as described above to obtain a laminated tube having a length of 200 mm.

300 ml of 1-menthol was enclosed in this laminate tube, and it was left in an environment of 40 ° C. and 90% RH for 500 hours. After that, the inner layer EEA / A
A peeling edge was made between l and the laminate (extrusion laminate) strength was measured. The results are shown in Table 5.

[0122]

[Table 5] Example 10 A resin composition similar to that of Example 2 and nylon 6 (Ny-
6) and saponified ethylene-vinyl acetate copolymer (EVO
H) and an ethylene-vinyl acetate copolymer obtained by graft-copolymerizing maleic anhydride as an adhesive resin layer were coextrusion-molded. The layer structure of the obtained composite film was Ny-
6 / EVOH / adhesive resin layer / heat seal layer = 60μ
m / 20 μm / 10 μm / 30 μm, total film thickness is 1
It was 20 μm.

Comparative Example 10 Example 10 was repeated except that an ethylene-vinyl acetate copolymer having a vinyl acetate content of 5 mol% (EVA, melt viscosity 2.3 g / 10 minutes) was used in place of the resin composition of Example 2. In the same manner as in No. 10, the layer structure is Ny-6 / EVOH / adhesive resin layer / heat seal layer = 60 μm / 20 μm / 10 μm / 3.
A film having a thickness of 0 μm and a total film thickness of 120 μm was produced.

The films obtained in Example 10 and Comparative Example 10 were heated by a vacuum forming machine (manufactured by Shin-Daigo Co., Ltd.) at an upper heater temperature of 180 ° C. and a preheating time of 0.
Vacuum pressure forming was performed for 5 seconds under a pressure of 2.5 kg / cm ² . The die has a diameter of 100 mm and a depth of 10 mm.

50 ml of pure water was placed in the obtained container having a diameter of 100 mm and a depth of 10 mm, and the lid member was heat-sealed as follows. For the container of Example 10, a film (20 μm) made of O-Ny (15 μm) as a lid material and the resin composition produced in the same manner as in Example 4 was used.
A film obtained by laminating and was heat-sealed. Further, for the container of Comparative Example 10, as a lid material,
A film obtained by laminating O-Ny (15 μm) and the film (20 μm) made of EVA used in Comparative Example 10 was heat-sealed. Heat seal is temperature 16
It was carried out under conditions of 0 ° C., pressure of 2 kg / cm ² , and time of 1 second.

The container filled with pure water was subjected to boil treatment at 80 ° C. for 30 minutes, opened immediately thereafter, and subjected to a sensory test by 10 panelists. As a result, in the container using the film of Example 10, All were judged to be odorless. On the other hand, in the container using the film of Comparative Example 10, 6 persons were determined to have an olefin odor.

Example 11 An ethylene-vinyl acetate copolymer graft-copolymerized with maleic anhydride, which constitutes the adhesive resin layer (2) and the same resin composition as in Example 2, and an ethylene-vinyl acetate copolymer were used. A polymer saponified product (EVOH), a modified polypropylene graft-copolymerized with maleic anhydride, which constitutes the adhesive resin layer (1), and polypropylene (PP) are coextrusion-molded,
A thick composite sheet for forming a container was produced.

The layer structure of the obtained composite sheet was PP layer /
Adhesive resin layer (1) / EVOH / Adhesive resin layer (2) / Heat seal layer = 500 μm / 22 μm / 110 μm / 22
μm / 350 μm, and the total film thickness was about 1 mm.

Comparative Example 11 Instead of the resin composition of Example 2, polypropylene (P
P, melting point 174 ° C.) except that the layer structure is PP / adhesive resin layer (1) / EVOH /
Adhesive resin layer (2) / PP = 350 μm / 22 μm / 11
A film having a thickness of 0 μm / 500 μm and a total film thickness of about 1 mm was produced.

The thick multilayer sheets obtained in Example 11 and Comparative Example 11 were applied to a heater moving type vacuum pressure air plug assist molding machine (VAS-33 manufactured by Semba Iron Works Co., Ltd.).
Vacuum pressure air plug assist molding was performed using P and a mold drawing pressure of 10 t) to prepare a molding container. The size of the mold is 90 mm in diameter, 60 mm in bottom diameter, and 67.5 mm in depth.
Molding timing chart, heater back time 2
Seconds, the plug moving time was 3.5 seconds, and the molding time was 0.5 seconds. Molding is performed at a mold temperature of 60 ° C., a plug temperature of 80 ° C., a heater temperature of 400 ° C., a preheating time of 20 seconds, and a compressed air pressure of 2.
It was carried out at 5 kg / cm ² + vacuum.

With respect to the obtained molded product, transparency, uneven thickness,
The four items of surface roughness and gloss were evaluated. The transparency was evaluated using a haze meter, and the uneven thickness was measured by measuring the film thickness of the body portion. Surface roughness is visually determined,
Gloss was evaluated using a gloss meter. The results are shown in Table 6.
Shown in.

[0132]

[Table 6] As is clear from Table 6, the multilayer sheet of Example 11 could be molded without any problems in practical use.

Further, in order to conduct an odorless test, 250 ml of pure water was enclosed in each molded product. As the lid member, in the molded article using the multilayer sheet of Example 11, the above-mentioned Example 10 was used.
In the molded article using the multi-layered sheet of Comparative Example 11 as the lid material produced in Comparative Example 11, the lid material produced in Comparative Example 10 was used.

The molded product in which pure water was enclosed was heated at a temperature of 110 ° C.
A retort treatment was performed for 20 minutes, the container was opened immediately after the retort treatment, and a sensory test was conducted by 10 panelists. As a result, all of the containers using the multilayer sheet of Example 11 were determined to be odorless. On the other hand, in the container using the multilayer sheet of Comparative Example 11, 8 persons were determined to have an olefin odor.

Example 12 A resin composition similar to that in Example 2 was used as a paper (100 g / m ² ).
It was extruded and laminated. The layer structure is a paper / heat seal layer (30 μm).

Comparative Example 12 Stretched polyethylene terephthalate film (PET, 3
0 μm) was dry laminated onto paper (100 g / m ² ).

Comparative Example 13 Polyethylene (PE) having a film thickness of 30 μm was coated on paper (100
g / m ² ) and extrusion laminated.

The films obtained in Example 12 and Comparative Examples 12 and 13 were treated at a temperature of 160 ° C., a time of 0.5 seconds and a pressure of 2.
A heat seal test was performed under the condition of kg / cm ² . Table 7 shows the measurement results of the heat seal strength.

[0139]

[Table 7] Furthermore, using the films of Example 12 and Comparative Example 13,
100m with 2g of p-dichlorobenzene sealed inside
An m-square four-way heat-sealed bag was produced.

The obtained heat-sealed bag was placed at 40 ° C. and 90 ° C.
It was left in an environment of% RH for 500 hours. After that, a peeling start end was formed between the paper constituting the films of Example 12 and Comparative Example 13 and the heat seal film layer, and the laminate (extrusion laminate) strength was measured. The results are shown in Table 5 above.

Example 13 Polypropylene was used in place of the resin composition of Example 2, and adhesive resin (1) was used in place of adhesive resin (2).
Similarly to, PP layer / adhesive resin layer (1) / EVOH /
A coextruded multi-layered sheet (total film thickness: about 1 mm) of 3 types and 5 layers consisting of the adhesive resin layer (1) / PP layer was obtained. The single layer film obtained in Example 3 was dry laminated on this multilayer sheet, and the layer constitution was PP layer / adhesive resin layer (1) / EV.
A composite sheet of OH / adhesive resin layer (1) / PP layer / heat seal layer was obtained.

Comparative Example 14 The PP layer / adhesive resin layer used in Example 13 was used as the layer structure.
A composite sheet of (1) / EVOH / adhesive resin layer (1) / PP layer was used.

The multilayer sheets of Example 13 and Comparative Example 14 were vacuum-compressed and air-plug assist-molded according to Example 11 and Comparative Example 11. Then, the lid member manufactured in Example 10 was used for the molded product using the multilayer sheet of Example 13, and the lid member manufactured in Comparative Example 10 was used for the molded product using the multilayer sheet of Comparative Example 14. A molded product containing pure water was produced in the same manner as in Example 10. An odorless test was conducted in the same manner as in Example 10 except that boil was performed at a temperature of 80 ° C. for 40 minutes, and it was determined that all 10 people were odorless in the container using the multilayer sheet of Example 13. On the contrary,
In the container using the multilayer sheet of Comparative Example 14, 7 persons were determined to have an olefin odor.

Example 14 Biaxially stretched polyethylene terephthalate film (PE
T, 12 μm) and soft aluminum (Al, 9 μm)
And the monolayer film obtained in Example 2 were dry laminated to obtain a composite film having a layer structure of PET / Al / heat seal layer.

COMPARATIVE EXAMPLE 15 In place of the monolayer film obtained in Example 2, a film (40 μm) obtained by subjecting a low density polyethylene resin (LDPE) to ordinary T-die extrusion was used, except that the film was obtained. As in Example 14, the layer structure was PET / Al / LDPE.
The film of was produced. This film construction is often used as a retort pouch.

Using the films obtained in Example 14 and Comparative Example 15, a bag in which pure water was sealed was prepared and the temperature was set to 121.
When subjected to an odorless test in the same manner as in Example 10 immediately after the retort treatment at 40 ° C. for 40 minutes, the bag using the film of Example 14 determined that all 10 people were odorless. did. On the other hand, in the bag using the film of Comparative Example 15, 6 people were determined to have an olefin odor.

Comparative Example 16 A PET / Al / heat seal layer was prepared in the same manner as in Example 14 except that the film obtained in Comparative Example 6 was used instead of the monolayer film obtained in Example 2. The film of was produced.

The films obtained in Example 14 and Comparative Example 16 were subjected to a temperature of 170 ° C., a time of 0.5 seconds and a pressure of 2 kg / cm.
^Under the conditions of ² , heat sealing was performed using a heat sealing tester of the top heating type. The heat seal strength results are shown in Table 7.

Comparative Example 17 A PET / Al / heat seal layer was prepared in the same manner as in Example 14 except that the film obtained in Comparative Example 5 was used instead of the single layer film obtained in Example 2. I got a film of.

The films obtained in Example 14 and Comparative Example 17 were heat-sealed in the same manner as in Comparative Example 16. The heat seal strength results are shown in Table 7.

Further, the films of Example 14 and Comparative Example 17 were heat-sealed in the same manner as above, and pure water 2
A 200 mm × 150 mm four-sided sealed bag in which 50 ml was enclosed was prepared and subjected to retort treatment under the conditions of a temperature of 121 ° C. and a time of 40 minutes.

No change was observed in the four-sided sealed bag of Example 14 by the retort treatment, but Comparative Example 17
The four-sided sealed bag of No. 1 was deformed by the retort treatment and the deformation was not recovered.

Example 15 A biaxially stretched nylon 6 film (O-Ny, 15 μm) was coated with a vinylidene chloride-acrylic acid ester copolymer in a thickness of 2 to 3 μm after drying, and the film (KO
N) was obtained. The single-layer film obtained in Example 2 was dry-laminated on the O-Ny surface of this film to obtain a composite film having a layer structure of KON / heat seal layer.

Comparative Example 18 In place of the monolayer film obtained in Example 2, a film having heat sealability (Toray Gosei Co., Ltd., Trefan NOT3931, film thickness 60 μm) was used, except that In the same manner, a film having a layer structure KON / heat seal layer was obtained.

Each of the films of Example 15 and Comparative Example 18 was subjected to a temperature of 170 ° C., a time of 1 second and a pressure of 1 kg / cm.
Heat sealing was carried out under the conditions of ² to prepare a 150 mm × 250 mm four-sided sealed bag enclosing 200 ml of pure water. The width of the heat-sealed portion was 10 mm. The obtained four-way heat-sealed bag was subjected to a retort treatment at a temperature of 110 ° C. for 20 minutes, and an odorless test was conducted in the same manner as in Example 10 and Comparative Example 10. The bag using the film of Example 15 was used. Then, all 10 persons judged to be odorless. On the other hand, in the bag using the film of Comparative Example 18, 6
A person determined that it had an olefinic odor.

Further, in the same manner as described above, 50 ml of pure water was sealed in 50 ml of white rice (washed) and the temperature was adjusted to 12
A retort treatment was performed at 1 ° C. for 40 minutes, and white rice was cooked. An odorless sensory test was conducted by 10 panelists. In the bag using the film of Example 15, 1 bag was obtained.
All 0 persons were judged to be odorless. On the other hand, Comparative Example 18
In the bag using the film of No. 3, 8 persons were judged to have an olefin odor.

Example 16 A low-density polyethylene (LDPE) was extruded and laminated to one side of a long fiber pulp type paper (300 g / m ² ) to a film thickness of 20 μm, and an ethylene-ethyl acrylate copolymer (EEA) was applied to the other side. ) Is extruded to a film thickness of 20 μm and laminated,
Extrusion lamination was performed with soft aluminum (Al, 9 μm). The monolayer film obtained in Example 2 was dry laminated to this. The layer structure is LDPE / paper / EEA / Al / heat seal layer.

Comparative Example 19 The procedure of Example 16 was repeated except that a film (40 μm) made of low density polyethylene (LDPE) was used instead of the monolayer film obtained in Example 2, and the layer structure was LDP.
A film of E / paper / EEA / LDPE was obtained.

A film having such a layer structure is generally used as a paper container.

Using the films obtained in Example 16 and Comparative Example 19, the bottom surface was 100 × 100 mm, and the height was 150 m.
A mail-top paper container of m (excluding the roof part) was produced. The end portion was heat-sealed by a method generally called a hemming method so that the cross section of the film structure was not exposed to the contents. The heat sealing conditions are a temperature of 190 ° C., a pressure of 2 kg / cm ² , and a time of 1.5.
Seconds. In Example 16, the heat-sealed surfaces were heat-sealed, and in Comparative Example 19, the LDPE surfaces were heat-sealed.

250 ml of fresh orange juice was enclosed in a Gail top type paper container. The temperature of the raw orange juice at the time of encapsulation was about 80 ° C. Then, the amount of adsorption of the film to d-limonene was examined. In other words, 5 galletop paper containers filled with fresh orange juice
After standing for 2 days, 7 days and 28 days in an environment of 0 ° C., the adsorbed amount of d-limonene per unit mass of the layer in contact with the content of the film was measured by gas chromatography. The results are shown in Table 8.

[0162]

[Table 8] Comparative Example 20 Example 1 was repeated except that the film (40 μm) produced in Comparative Example 8 was used instead of the monolayer film obtained in Example 2.
A film having a layer structure of LDPE / paper / EEA / heat seal layer was obtained in the same manner as in 6.

Using the film, a Gail top type paper container similar to that of Comparative Example 19 was prepared, and 250 ml of fresh orange juice was enclosed at about 80 ° C. as in Comparative Example 19. However, due to poor heat sealability, liquid leakage occurred when the fresh orange juice was filled.

Example 17 Biaxially Stretched Polypropylene Film (OPP, 20 μm)
And a biaxially stretched polyethylene terephthalate film (P
ET, 12 μm) with aluminum (Al) thickness 500
Vacuum-deposited film in Angstrom (VM-PE
T) and were dry laminated. The single layer film obtained in Example 2 was dry laminated on the obtained dry laminated film, and the layer constitution was OPP layer / VM-
A PET layer / heat seal layer composite film was obtained.

Comparative Example 21 Instead of the monolayer film obtained in Example 2, ethylene-
Heat seal film made of α-olefin copolymer (CPP) (Toray Gosei Co., Ltd., Trefan T393)
A film having a layer structure of OPP / VM-PET / CPP was obtained in the same manner as in Example 17, except that the film thickness was 1, 60 μm).

The film having such a layer structure is often used as a transparent bag for high temperature and high pressure sterilization treatment.

The films obtained in Example 17 and Comparative Example 21 were processed at a temperature of 170 ° C., time of 1 second and pressure of 1 kg / cm ^2.
Heat seal under the conditions of 1-menthol 50
A 100 × 150 mm four-sided heat-sealed bag enclosing ml was produced.

The obtained four-way heat-sealed bag was used in Example 9
Then, similarly to Comparative Example 9, the laminate was left in an environment of a temperature of 40 ° C. and a humidity of 90% RH for 250 hours, after which a peeling start end was formed between the VM-PET layer and the heat seal layer, and the laminate strength was measured. The results are shown in Table 5.

Example 18 A vinylidene chloride-acrylic ester copolymer film having a thickness of 2 was formed on a biaxially stretched nylon 6 film (O-Ny, 18 μm).
~ 3μm coated film (K
ON) was obtained. Low density polyethylene (L
DPE) was extrusion coated to a film thickness of 40 μm, and low density polyethylene (LDPE) was extrusion coated to 100 μm on the other surface. LD of the obtained laminated film
On the PE (100 μm) surface, a single-layer film having a thickness of 60 μm prepared in advance using the same resin composition as in Example 2 was dry laminated, and the layer configuration was LDPE (40 μm
m) / KON / LDPE (100 μm) / heat seal layer composite film was obtained.

Comparative Example 22 The procedure of Example 18 was repeated except that a film (60 μm) made of an ethylene-vinyl acetate copolymer (EVA) was used in place of the monolayer film having a thickness of 60 μm used in Example 18. , Layer composition is LDPE (40 μm) / KON / L
A film of DPE (100 μm) / EVA was obtained.

A film having such a layer structure is often used as a transparent high temperature high pressure sterilization bag.

A four-way heat-sealing bag was prepared from each of the films of Example 18 and Comparative Example 22 under the same conditions as in Comparative Example 18, and 200 ml of pure water was filled at a filling temperature of 80 ° C. and sealed. After leaving the bag in an environment of a temperature of 40 ° C. and a humidity of 90 RH% for 250 hours, Example 10 and Comparative Example 1
The odorlessness test was conducted by 10 panelists in the same manner as in No. 0, and it was 10 in the bag using the film of Example 18.
All were judged to be odorless. On the other hand, in the bag using the film of Comparative Example 22, 7 persons were determined to have an olefin odor.

Example 19 A single layer film having a thickness of 20 μm produced in the same manner as in Example 2 was dry laminated with cloud paper (20 g / m ² ). The layer structure is cloud flow paper / heat seal layer.

Comparative Example 23 Low Density Polyethylene (LDPE) Film (20 μm)
Was dry laminated with cloud flow paper (20 g / m ² ). A film having such a layer structure is used for packaging Japanese sweets and the like.

The films obtained in Example 19 and Comparative Example 23 were subjected to a temperature of 160 ° C., a time of 1 second and a pressure of 1 kg / cm ^2.
Was heat-sealed to prepare a 50 × 50 mm square four-sided heat-sealed bag. 100 mg of lemon flavor was enclosed in a four-sided heat-sealed bag. This four-way heat-sealed bag was left in an environment of a temperature of 40 ° C. and a humidity of 90% RH, and the time until the scent leaked was measured. The results are shown in Table 9.

[0176]

[Table 9] Example 20 Vinylidene chloride-based copolymer (PVDC) -coated cellophane (KT, 26 μm), biaxially oriented nylon 6 film (O-Ny, 15 μm), and monolayer film 40 μm obtained in Example 2 Was subjected to dry lamination to obtain a composite film having a layer structure of KT / O-Ny / heat seal layer.

Comparative Example 24 The layer structure was the same as in Example 20 except that a film (40 μm) made of low density polyethylene (LDPE) was used in place of the monolayer film obtained in Example 2, and the layer structure was KT /
A film of O-Ny / LDPE was obtained.

In Example 20 and Comparative Example 24, the PVDC layer of KT was scribed before being laminated to generate defects.

The film having such a layer structure is used for packaging high-grade miso and the like.

The films obtained in Example 20 and Comparative Example 24 were heated at a temperature of 160 ° C. for 1 second and at a pressure of 1 kg / cm ^2.
Was heat-sealed to prepare a 150 × 150 mm square four-sided heat-sealed bag. The squid salt and l-menthol were enclosed in a four-way heat-sealed bag. This four-way heat-sealed bag was left in an environment of a temperature of 40 ° C. and a humidity of 90% RH, and the time until the scent leaked was measured. The results are shown in Table 9
Note.

The oxygen permeability of the films of Example 20 and Comparative Example 24 was measured according to ASTM D-1434-58. The results are shown in Table 10.

[0182]

[Table 10] As is clear from Table 10, the film of Example 20 was
The oxygen barrier property is superior to that of the film of Comparative Example 24. From this, it is effective for high-grade miso applications. Further, when the film of Example 20 is used, high barrier property can be secured even when the PVDC surface of KT is scratched.

Example 21 A long fiber pulp type paper (300 g / m ² ) was coated with ethylene-ethyl acrylate copolymer (EEA) on one side to a film thickness of 15 μm.
m by extrusion coating, soft aluminum (Al,
9 μm) and dry lamination. Next, the single layer film obtained in Example 3 was dry laminated on the obtained laminated film, and the layer constitution was paper / E.
A composite film of EA / Al / heat seal layer was obtained.

Comparative Example 25 The procedure of Example 21 was repeated except that a film (40 μm) made of low density polyethylene (LDPE) was used instead of the monolayer film obtained in Example 3, and the layer structure was paper / paper.
A composite film of EEA / Al / heat seal layer was obtained.

A film having such a layer structure is generally used for packaging sheep's cans and the like.

The films obtained in Example 21 and Comparative Example 25 were slit into a width of 120 mm, heat-sealed at a temperature of 190 ° C. for a time of 1 second and a pressure of 1 kg / cm ² , and made into a gusset bag to prepare a tube. This tube was filled with sheep's can in a heated and fluidized state. The work went smoothly and there were no particular problems.

Further, the films of Example 21 and Comparative Example 25 were heat-sealed at a temperature of 190 ° C. for 1 second and a pressure of 1 kg / cm ² to produce a 150 × 150 mm square four-sided heat-sealed bag. In addition, about 150 pinholes were intentionally opened in the soft aluminum forming the films of Example 21 and Comparative Example 25. Enclose 50g of matcha powder in a four-sided heat-sealed bag, temperature 40 ℃, humidity 90%
The sample was left in the environment of RH and the time until the scent leaked was measured. The results are shown in Table 9 above.

As is clear from Table 9, when the film of Example 21 is used, the scent does not scatter even if pinholes are formed in the Al thin film.

Example 22 Vinylidene chloride-vinyl acetate copolymer was coated on a biaxially stretched nylon 6 film (O-Ny, 18 μm) to a film thickness of 2 to 3 μm.
The single-layer film obtained in Example 1 was dry-laminated on one side of the film (KON) coated on 1. and the single-layer film obtained in Example 2 was dry-laminated on the other side. The layer structure of the obtained composite film is heat seal layer (1) / KON / heat seal layer (2). The monolayer film obtained in Example 1 constitutes the heat seal layer (1), and the monolayer film obtained in Example 2 constitutes the heat seal layer (2).

Comparative Example 26 A film (40 μm) made of low density polyethylene (LDPE) was used in place of the monolayer film obtained in Example 1, and ethylene was used instead of the monolayer film obtained in Example 2. -In the same manner as in Example 22 except that a film (40 µm) made of a vinyl acetate copolymer (EVA) was used,
A composite film having a layer constitution of heat seal layer (1) / KON / heat seal layer (2) was obtained.

A film having such a layer structure is often used as a stick packaging of a transparent liquid.
The heat-sealing method is so-called sealing such as heat-sealing the inner and outer surfaces.

The films of Example 22 and Comparative Example 26 were made to have a width of 3
It was slit to 0 mm, rolled into a tube, and heat-sealed at the end. At that time, both films were processed so that the heat seal layer (2) was located on the inner surface of the tube.
The heat seal is heated only from the outside, and the heat seal conditions are a temperature of 160 ° C., a time of 0.5 seconds, and a pressure of 2 kg /
cm ² . The width of the heat-sealed portion was 5 mm, and the size of the stick was 12 mm × 100 mm.

When the obtained tube was filled with a liquid by a filling machine, the film of Comparative Example 26 meandered on the line by the filling machine, but the film of Example 22 could be smoothly filled without meandering. The reason for this is presumed to be that the film of Example 22 has higher rigidity than the film of Comparative Example 26. It is a measure of rigidity,
Table 11 shows the values of tensile modulus. The elastic modulus is JI
It was measured according to S Z1707.

[0194]

[Table 11] Further, as a content, 50 ml of 1-menthol was enclosed, and the sample was left at a temperature of 40 ° C. and a humidity of 50% RH for 500 hours in the same manner as in Example 9 and Comparative Example 9, and then the heat seal strength was measured. The results shown in Table 7 were obtained.

Example 23 A resin composition similar to that of Example 2, high impact polystyrene (HIPS), and an ethylene vinyl acetate copolymer resin graft-copolymerized with maleic anhydride to form an adhesive resin layer. Was coextruded. The layer structure of the obtained composite film was HIPS layer / adhesive resin layer / heat seal layer = 2.
00 μm / 20 μm / 180 μm, total film thickness is 40
It was 0 μm.

Comparative Example 27 The layer structure was the same as in Example 23 except that low density polyethylene (LDPE) was used instead of the resin composition used in Example 2, and the layer structure was HIPS layer / adhesive resin layer / LDPE. A composite film with a layer = 200 μm / 20 μm / 180 μm was obtained.

The composite films obtained in Example 23 and Comparative Example 27 were subjected to vacuum pressure air plug assist molding in the same manner as in Example 11 and Comparative Example 11 to prepare a container.

Such a container is preferably used for fresh milk for coffee, jelly and the like.

The uneven thickness of the vacuum-pneumatic plug-assisted molded product thus obtained was evaluated in the same manner as in Example 11 and Comparative Example 11, and it was found to be 250 to 260 μm. Use of the film of Example 23 did not change the moldability as compared with the film of Example 11.

Further, using the lid materials produced in Example 10 and Comparative Example 10, 50 ml of 1-menthol was sealed in a vacuum-pressure air plug assisted molded product in the same manner as in Example 10 and Comparative Example 10, and the temperature was 40 ° C. The sample was left in an environment with a humidity of 50% RH, and the time until the l-menthol leaked was measured. The results are shown in Table 9.

Example 24 A composite film having the same resin composition as in Example 1 as the heat seal layer and polybutylene terephthalate (PBT) as the base material layer (heat resistant resin layer) was prepared as follows. That is, the silica fine powder having an average particle diameter of 5 to 10 μm is 0.3
A resin composition similar to that of Example 1 containing 1% by weight and PBT were produced by a multi-manifold die using different extruders, respectively, to produce a coextrusion composite film of two types and two layers. The layer structure of the obtained composite film was PBT layer / heat seal layer = about 30 μm / about 40 μm, and the total film thickness was 80 to 7
It was 0 μm.

In this example, the adhesive resin for bonding the PBT layer and the heat seal layer was not particularly required.

Examples 25 to 30 Instead of the resin composition used in Example 24, the average particle size is 5 to 5.
A composite film was produced in the same manner as in Example 24 except that the following resin composition containing 0.3% by weight of 10 μm silica fine powder was used.

Example 25: Resin composition of Example 2 Example 26: Resin composition of Example 3 Example 27: Resin composition of Example 4 Example 28: Resin composition of Example 5 Example 29 : Resin composition of Example 6 Example 30: Resin composition of Example 7 In each of these composite films, the layer structure was PBT layer / heat seal layer = about 30 μm / about 40 μm, and the total film thickness was It is 80 to 70 μm. In addition, even in these examples,
The adhesive resin for bonding the PBT layer and the heat seal layer is
It wasn't necessary.

The heat-sealing surfaces of the composite films obtained in Examples 24 to 30 were heat-sealed under the same heat-sealing conditions as in Examples 1 to 7 to measure the heat-sealing strength and the elongation at break. did. The results are shown in Table 12.

[0206]

[Table 12] As is clear from Table 12, the composite films of Examples 24 to 30 not only have high heat-sealing strength, but also have high breaking elongation even if they are not stretched. Also, Table 3
As is clear from the comparison with Examples 4 and 4, the breaking elongation is larger than that of the monolayer films of Examples 1 to 7.

Examples 31 to 37 Of the composite films obtained in Example 25, the following films were dry laminated on the PBT layer surface to obtain composite films.

Example 31: Uniaxially oriented polypropylene film (OPP, 20 μm) Example 32: Biaxially oriented polypropylene film (OP
P, 20 μm) Example 33: Biaxially stretched OPP film coated with vinylidene chloride copolymer to a film thickness of 2-3 μm after drying (KOP) Example 34: Biaxially stretched polyethylene terephthalate film (PET, 12 μm) ) Example 35: A film (K-PET) obtained by coating a biaxially stretched PET film with a vinylidene chloride copolymer to a film thickness of 2 to 3 μm after drying (K-PET) Example 36: Biaxially stretched nylon 6 film (O-Ny,
15 μm) Example 37: Biaxially stretched O-Ny film coated with vinylidene chloride copolymer in a thickness of 2 to 3 μm after drying (KON) Heat sealing of the composite films obtained in Examples 31 to 37 The heat seal strength and the breaking elongation of the surfaces were measured in the same manner as described above. The results are shown in Table 13.

[0209]

[Table 13] As is clear from Table 13, the composite films of Examples 31 to 37 have high heat seal strength and elongation at break.

Examples 38 to 40 Ethylene-vinyl acetate copolymer graft-copolymerized with the resin composition used in Example 2, polybutylene terephthalate (PBT), and an adhesive resin layer to form maleic anhydride. And the following polymer was subjected to coextrusion molding to obtain a composite film having a layer structure of polymer layer / adhesive resin layer / PBT layer / heat seal layer = 40/10/20/20.

Example 38: Polypropylene (PP) Example 39: Polyethylene terephthalate (PET) Example 40: Nylon 6 (Ny-6) The heat-sealing surfaces of the composite films obtained in Examples 38 to 40 were the same as described above. In the same manner as above, the heat seal strength and the breaking elongation were measured. The results are shown in Table 14.

[0212]

[Table 14] As is clear from Table 14, the composite films of Examples 38 to 40 not only have high heat-sealing strength, but also have high breaking elongation even if they are not stretched.

Examples 41 to 43 Instead of the polycarbonate used in Example 2, polycarbonates having different molecular weights [manufactured by Mitsubishi Gas Chemical Co., Inc., S-
1000; molecular weight 10000] (Example 41), polycarbonate [Mitsubishi Gas Chemical Co., Inc., E-2000; molecular weight 20000] (Example 42), polycarbonate [Mitsubishi Gas Chemical Co., Ltd., S-3000; molecular weight 300
00] (Example 43) was used to prepare a mixture having the same plasticity ratio as in Example 2 and in the same manner as in Example 2 to obtain a monolayer film having a thickness of 40 μm.

The obtained films exhibited the same heat-sealing strength, whitening degree and breaking elongation as those of the monolayer film obtained in Example 2.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between heat seal temperature and heat seal strength in Example 1 and Comparative Example 2.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08L 69/00 LPR 8416-4J // B29K 67:00 B29L 7:00 4F C08L 67:00 8933- 4J 69:00

Claims (15)

[Claims] 1. A dicarboxylic acid component comprising (a) at least one diol component selected from aliphatic diols, alicyclic diols and aromatic diols, and terephthalic acid or two or more dicarboxylic acids containing at least terephthalic acid. (However, when the dicarboxylic acid component is terephthalic acid, the diol component is not an aliphatic diol, an alicyclic diol, or an aromatic diol alone) and a (b) polycarbonate. A polyester resin composition containing the same. 2. The polyester system according to claim 1, wherein the copolyester is a copolyester of two or more diol components containing at least an aliphatic diol and two or more dicarboxylic acids containing terephthalic acid or at least terephthal. Resin composition. 3. A copolyester comprising an aliphatic diol,
The polyester resin composition according to claim 1, which is a copolyester with two or more kinds of dicarboxylic acids containing at least terephthal. 4. The polyester resin composition according to claim 2, wherein the aliphatic diol is 1,4-butanediol. 5. The polyester resin composition according to claim 2, wherein the diol component is 1,4-butanediol and 2,2-bis (4-hydroxyethoxyphenyl) propane. 6. The copolyester is a copolyester of 50 mol% of a diol component consisting of an aliphatic diol / another diol = 25 to 95/75 to 5 (molar ratio) and 50 mol% of terephthalic acid. Item 2. The polyester resin composition according to item 2. 7. The copolyester is an aliphatic diol 50.
Mol% and terephthalic acid / other dicarboxylic acid = 5 to 95
The polyester resin composition according to claim 3, which is a copolyester with 50 mol% of a dicarboxylic acid component in a ratio of / 95 to 5 (molar ratio). 8. A polycarbonate is represented by the following general formula [V]: The polyester resin composition according to claim 1, having a repeating unit represented by the formula (wherein R ₈ and R ₉ are the same or different and each represents a hydrogen atom, a lower alkyl group, a cycloalkyl group or an aryl group). . 9. The melting point of copolyester is 150 to 21.
The polyester resin composition according to claim 1, which is in the range of 0 ° C. 10. The polyester resin composition according to claim 1, which comprises (a) 50 to 90% by weight of copolyester and (b) 50 to 10% by weight of polycarbonate. 11. A film having heat sealability, which is formed of the polyester resin composition according to claim 1. 12. A heat-sealable film according to claim 11, wherein at least one base material layer is laminated on one surface of the layer formed of the polyester resin composition according to claim 1. 13. The heat-sealable film according to claim 12, wherein the base material layer contains at least a heat-resistant resin layer. 14. The base layer is composed of a heat resistant resin layer and a polymer selected from olefin polymers, polyesters and nylon polymers.
A film having a heat-sealing property according to 2. 15. The heat-sealable film according to claim 13, wherein the heat-resistant resin layer is a polybutylene terephthalate layer.