JP3048264B2 - Polyester resin composition and film having heat sealability - Google Patents

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 sealing properties suitable as various packaging films.

[0002]

2. Description of the Related Art A heat-sealing film is used as an inner layer material of various packaging materials, that is, pouches for retort, pillow packaging, tubes and the like. As these heat-sealing films, 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.

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

[0004] 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 promote crystallization, 70
Softens at a temperature of about ° C. Therefore, although the polyethylene terephthalate film is usually stretched, the stretched film hardly exhibits heat sealability. Copolyesters in which part of terephthalic acid constituting polyethylene terephthalate is substituted with isophthalic acid, and copolyesters in which part of ethylene glycol is substituted with 1,4-cyclohexanedimethanol are also known. However, these resins are inferior in heat sealability or inferior heat resistance in a sterilization process such as retort. As described above, generally, a polymer film having high heat resistance is inferior in heat sealability, and cannot achieve both high heat resistance and heat sealability. For example, polybutylene terephthalate is also known as a polymer exhibiting high heat resistance without stretching, but a film made of this polymer does not have heat sealability.

Accordingly, an object of the present invention is to provide a polyester resin composition which is useful for obtaining a film having high heat resistance and heat sealability, despite being a polyester.

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

It is still another object of the present invention to provide a film having excellent mechanical strength, heat resistance and heat sealability even if it is not subjected to a stretching treatment.

[0008]

The present inventor has set out the following objects in order to achieve the above object.
As a result of intensive studies on the polyester resin composition, a film produced using a resin composition containing a modified polyalkylene terephthalate and polycarbonate was found to be excellent in heat sealability and heat resistance, and completed the present invention. .

That is, the present invention relates to (a) two or more kinds selected from aliphatic diols, alicyclic diols and aromatic diols and containing at least an aliphatic C _4-6 diol.
Derived from the above diol component and terephthalic acid ,
A polyester resin composition comprising a copolyester having a temperature in the range of 150 to 210 ° C. and (b) polycarbonate , wherein said aliphatic C _4-6 diol and another
C _4-6 diol / other diol
= 50-90 / 50-10 (molar ratio) and substantially
Contains no poly (1,4-butylene terephthalate)
A polyester resin composition is provided. The present invention
(A) an aliphatic C _4-6 diol, at least
Derived from two or more dicarboxylic acids, including tartrate,
Copolyester having a melting point in the range of 150 to 210 ° C.
And polyesters containing (b) polycarbonate
A resin composition, comprising: (a) a copolyester 70 to 90;
% By weight, and (b) 30 to 10% by weight of polycarbonate
% And substantially poly (1,4-butylene tele)
Phthalate) -free polyester resin composition
Offer. Aliphatic C _4-6 diol is 1,4-butanediol
And the diol component may be 1,4-butadiene.
Diol and 2,2-bis (4-hydroxyethoxy)
(Phenyl) propane.

[0010] As described above, when the dicarboxylic acid component is terephthalic acid, diol component and should not be interpreted as an aliphatic C _4-6 Geo <br/> Lumpur alone.

[0011] The present invention also provides a heat-sealing film comprising: a film formed from the polyester resin composition; and one surface of a layer formed from the polyester resin composition, at least one substrate. A film in which a material layer is laminated; a film in which the base 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 aromatic ring via an alkylene group or an alkylenedioxy group. It is used to include a compound in which a hydroxy group is bonded indirectly.

Unless otherwise specified, "terephthalic acid", "dicarboxylic acid" and "dicarboxylic acid component" are used in the esterification reaction such as lower alkyl esters, acid anhydrides and acid halides. It is used in a sense including derivatives of commonly used carboxylic acids.

"Film" is used to include substantially any flat structure that may be referred to in the art as a sheet.

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

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

[0017] As aliphatic diols, for example, diethylcarbamoyl <br/> glycol, triethylene glycol, di propylene <br/> glycol, tripropylene glycol, 1, 3-butanediol, 1,4-butanediol , neopentyl glycol, 1,5-pentanediol, aliphatic C _4-6 diol of 1,6 hexanediol Le, etc.. In addition, ethylene glycol, propylene glycol
, Polyethylene glycol, polypropylene glycol
And polymethylene glycol may be used in combination.

As the alicyclic diol, for example, 1,4
-Cyclohexanediol, 1,4-cyclohexanedimethanol, 2,2-bis (4-hydroxyethoxycyclohexyl) propane, hydrogenated bisphenol A
And adducts with alkylene oxides such as ethylene oxide and propylene oxide.

Examples of the aromatic diol include, for example, adducts of resorcinol, naphthalene diol, 2,2-bis (4-hydroxyphenyl) propane, and bisphenol A with alkylene oxides such as ethylene oxide and propylene oxide. , 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,
Examples thereof include 2,2-bis (4-hydroxypolypropoxyphenyl) propane.

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 terephthalic acid derivatives 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; and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, and 3-sulfoisophthalic acid. . 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 diols and / or dicarboxylic acids to form a modified polyester. That is, (1) diol component is a single
In the case of an aliphatic C _4-6 diol, two or more dicarboxylic acids containing at least terephthalic acid are used as the dicarboxylic acid component . Hand, (2) a diol component low
If it is not even two or more diols containing an aliphatic C _4-6 diol, dicarboxylic acid component, terephthalic acid Ru is used alone.

In the above embodiments (1) and (2), among the aliphatic diols, a particularly preferred diol component is 1,4-butanediol alone or at least from the viewpoint of heat resistance in the process of sterilization such as retort. Two or more diols containing 1,4-butanediol as an essential component.
Examples of the diol which can be partially substituted with 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]

Embedded image (Wherein, R ₁ , R ₂ , R ₃ and R ₄ are the same or different and each represent a hydrogen atom or a methyl group, and l and m each represent a positive integer.) The aromatic compound 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 preferred.

A copolyester containing no 1,4-butanediol as a constituent monomer has a low degree of crystallinity at the time of film formation, and the heat resistance tends to be low.

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

The copolyester is obtained by subjecting the diol component and the dicarboxylic acid component to substantially equivalent molar use and subjecting them to an esterification reaction. In the above embodiments (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 type of the diol and dicarboxylic acid, the desired heat sealing temperature, and the like.

In the above embodiment (1), a preferred copolyester is 50 mol% of aliphatic C _4-6 diol and terephthalic acid / other dicarboxylic acid = 5 to 95/95 to 5 (molar ratio), preferably It is a copolyester with 50 mol% of a dicarboxylic acid component having a ratio of 10 to 75/90 to 25 (molar ratio), more preferably 20 to 50/80 to 50 (molar ratio). More specifically, when the copolyester is a copolymerized polyester 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).

Further, in embodiments of the (2), preferred copolyesters are aliphatic C _4-6 diol / other diol = 5 0-90 / 50 to 10 (molar ratio), is good Mashiku 7
It is a copolymerized polyester of 50 mol% of a diol component consisting of 0 to 90/30 to 10 (molar ratio) and 50 mol% of terephthalic acid. More specifically, the copolyester is
Terephthalic acid, 1,4-butanediol and 2,2-
In the case of a copolymerized polyester with bis (4-hydroxyethoxyphenyl) propane, 1,4-butanediol / 2,2-bis (4-hydroxyethoxyphenyl)
Propane = 60-95 / 40-5 (molar ratio), especially 70
It is preferably about 90/30 to 10 (molar ratio).

With respect to heat sealability, the melting point of the copolyester is also important. That is, in the relationship between the heat seal temperature and the heat seal strength, the temperature at which the heat seal strength is developed largely depends on the melting point of the copolyester. The melting point of the copolyester is preferably in the range from 150 to 210C. Melting point of copolyester is 15
When the temperature is lower than 0 ° C., the films are easily blocked in a heat sterilization treatment such as a retort. 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 apparatus or the like.

The copolyester may have an appropriate molecular weight within a range that does not impair moldability, mechanical strength, and the like. 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 is determined at 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 dl / g.
It is about dl / g.

The method for producing the copolyester is not particularly limited and can be carried out according to a conventional method, for example, a transesterification method or a direct esterification method.

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

The polycarbonate has the following general formula [III]
And a repeating unit represented by

[0037]

Embedded image (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, 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.

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

[0039]

Embedded image (Wherein, R ₆ and R ₇ represent a halogen atom, a phenylene group or a cycloalkylene group which may be substituted with an alkyl group. X and Y are the same or different and represent a hydrogen atom, 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 Polycarbonate is not limited to a straight chain, but includes a branched polycarbonate in which the above-mentioned repeating unit is branched from the main chain.

Suitable polycarbonates are bisphenol-type polycarbonates having a repeating unit represented by the following general formula [V], and particularly, 2,2-bis (4-hydroxyl) having a repeating unit represented by the following formula [VI]. Phenyl)
It is a bisphenol A-type polycarbonate starting from propane.

[0041]

Embedded image (Wherein, R ₈ and R ₉ are the same or different and represent a hydrogen atom, a lower alkyl group, a cycloalkyl group, or an aryl group)

[0042]

Embedded image The lower alkyl group in the repeating unit represented by the general formula [V] includes an alkyl group having about 1 to 4 carbon atoms. Cycloalkyl groups include, for example, cyclopentyl,
Cyclohexyl and cyclooctyl groups are included. Aryl groups include phenyl, naphthyl groups and the like.

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 inherent viscosity of polycarbonate is 20
0.3 to 1.0 d when methylene chloride is used 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, if the melt viscosities of the copolyester and the polycarbonate at the same temperature are significantly different, a uniform melt mixture may not be obtained, resulting in poor dispersion. Therefore, it is preferred that the molecular weight of the polycarbonate be selected so that the melt viscosities of the copolyester and the polycarbonate match or approximate.

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

The method for producing the polycarbonate is not particularly limited, and a conventional method such as a phosgene method (solvent method) or a transesterification method (melt 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 sealing strength on the heat sealing temperature. More specifically, a modified copolyester in which the development of heat seal strength strongly depends on the heat seal temperature, for example, a modified polybutylene terephthalate obtained by partially replacing terephthalic acid with isophthalic acid will be described as follows. .

The copolyester alone exhibits heat seal strength only at high temperatures, and shows little heat seal strength below the heat sealable temperature. As described above, the heat sealing strength is strongly dependent on the heat sealing temperature, and the temperature range in which the heat sealing can be performed is narrow. Therefore, in an actual heat sealing operation, poor sealing is likely to occur.

On the other hand, when polycarbonate is contained, the heat sealing strength is exhibited even when heat sealing is performed at a temperature lower than the temperature at which the heat sealing strength of the copolyester is exhibited. Therefore, the heat sealing temperature can be shifted to a lower temperature side, and high heat sealing strength can be exhibited in a wide temperature range. This is presumably because the addition of the polycarbonate to the copolyester lowers 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 following description will be made with reference to polybutylene terephthalate and the modified copolyester in which whitening of the heat-sealed portion is remarkably observed.

In general, polybutylene terephthalate is not only easily crystallized, but also has a high crystallization rate and a high degree of crystallinity. Further, since the modified copolyester has been modified by copolymerization, it is better than polybutylene terephthalate,
Although the crystallization rate and the degree of crystallinity are small, they are still large. Therefore, when the copolyester is used alone, a phenomenon occurs in which the crystallization excessively proceeds in the slow cooling process after the heat sealing, and the heat-sealed portion becomes white. Then, due to this whitening phenomenon, the commercial value of the manufactured product decreases.

On the other hand, when polycarbonate is added to the modified copolyester, the heat-sealed portion does not whiten.
The above effects are remarkable for bisphenol-type polycarbonates containing a repeating unit represented by the general formula [V], particularly the formula [VI]. This is presumed to be because the addition of polycarbonate to the modified copolyester results in a low crystallization rate and a low degree of crystallization, as described above.

[0054] The ratio between the copolyester and polycarbonate, copolyester and depending on the type of polycarbonate, the characteristics can be selected from a range not impaired, for example, copolyester / polycarbonate = 7 0-90 / 3 0
It is about 10 (% by weight). If the content of polycarbonate is too large , depending on the type of polycarbonate, heat sealability and mechanical strength may be reduced,
If it is less than 10% by weight, whitening is likely to occur in the heat-sealed portion.

The resin composition of the present invention may contain various additives as long as the above-mentioned properties and heat sealing properties are not impaired. Examples of the additives include antioxidants, ultraviolet absorbers, heat stabilizers, plasticizers, antistatic agents, tackifiers, fillers, waxes, lubricants, dyes and pigments. One or more of these additives can be used. It is preferable to add a lubricant and a heat stabilizer from the viewpoint of machine suitability during film formation. As the lubricant, silica fine 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 can be used as a usual molding material,
Although it can be used as a fiber-reinforced composite material, it is suitable as a film-forming material.

The heat-sealing film of the present invention comprises (i) a single-layer film formed of the polyester resin composition, and (ii) a layer formed of the polyester resin composition on one surface. And a composite film on 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 substrate 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, and poly-4-methylpentene-1.
Olefin polymers such as ethylene; vinyl alcohol copolymer; polyvinyl chloride; vinylidene chloride polymers such as vinylidene chloride-acrylate copolymer, vinylidene chloride-vinyl chloride copolymer, vinylidene chloride-acrylonitrile copolymer. Styrene-based polymers such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, and high-impact polystyrene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; nylons or polyamides; polyacrylonitrile;
Polycarbonate; polyimide; cellophane and the like. Among these polymers, olefin polymers (particularly polypropylene), polyesters and nylons are preferred.

The metal thin film may be formed by a film forming means such as vapor deposition or by laminating, and the polymer layer may be formed by coating or laminating. The polymer layer may be further coated with the vinylidene chloride-based polymer, and a metal thin film may be formed by means such as vapor deposition.
Further, the polymer layer may be unstretched or may be subjected to a uniaxial or biaxial stretching treatment. Further, the polymer layer may be composed of a plurality of layers of the same or different polymers.

In the composite film (ii), the base 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 and polyamide such as aromatic polyamide; polyacetal; polycarbonate; polyphenylene oxide; polyester such as polyethylene terephthalate, polybutylene terephthalate and polyester type liquid crystalline polymer; And polyetheretherketone; polyamideimide; polyetherimide; and aromatic polyimide. 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 a layer made of the polyester resin composition by co-extrusion 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 preferred. The polybutylene terephthalate only needs to have a molecular weight in a range that does not impair moldability, mechanical strength, and the like. 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., at least about 0.5 dl / g or more, preferably 0.1 dl / g or more.
It is about 5 to 2.5 dl / g.

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

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

The heat resistant resin layer may contain a small amount of the resin composition as long as the properties are not impaired. That is, when the heat-resistant resin layer and the layer formed of the resin composition are laminated by a co-extrusion molding method, the end of the composite film may be collected, pelletized again, and subjected to extrusion molding. In this case, the regenerated pellets can be added to the heat-resistant resin and extruded. The added amount of the regenerated pellets to the heat-resistant resin was 30% by weight.
Hereinafter, it is preferably 20% by weight or less. Further, the regenerated pellets may be used as a material for an intermediate layer between a heat-resistant resin layer and a layer formed of the resin composition.

The heat-resistant resin layer may be directly laminated on a 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.

Among the above-mentioned composite films (ii), another preferred composite film has a base material layer comprising a heat-resistant resin layer, an olefin-based polymer such as polypropylene, a polyester such as polyethylene terephthalate, and a nylon-based material such as nylon 6. And a polymer layer selected from a polymer. The laminated form of the composite film may be 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 polymer layer may be laminated via the polymer layer. A layer formed of a resin composition may be laminated. The preferred lamination form is the former. Further, in these laminated forms, usually, since a high mechanical strength can be ensured by the heat-resistant resin layer, the polymer layer does not necessarily have to be stretched, but in order to further increase the mechanical strength, the polymer layer is It is preferably uniaxially stretched, preferably biaxially stretched.

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

The base layer may contain a polymer or the above-mentioned additives. As the polymer, for example,
Olefin polymer; acrylic polymer; styrene polymer; polyester; polyacetal; polyvinyl acetate; polyvinyl chloride;
Chlorinated polyolefins; cellulosic polymers; vinyl chloride-vinyl acetate copolymers and the like are exemplified. These polymers are used alone or in combination of two or more. These polymers are used in a range that does not impair heat resistance and the like. In particular, depending on the type of the olefin-based polymer, if the olefin-based polymer is contained in a large amount in different types of polymers, heat resistance and transparency may be impaired.

The heat-sealing single-layer film of the present invention can be produced by a conventional method, for example, an extrusion molding method such as an ordinary T-die method or an inflation method using an extrusion molding machine. Further, the composite film is formed by a conventional method, for example, a co-extrusion molding method in which a laminate is formed by a co-extrusion molding machine; an extrusion in which a molten resin composition is extruded onto a base film constituting a base layer to form a laminate layer. Laminating method: It can be manufactured by a dry laminating method of laminating a base film and a heat seal layer via an adhesive layer. According to the coextrusion molding method, the productivity of the composite film is high.

In the co-extrusion method for producing a composite film using a plurality of polymers, various methods can be adopted. For example, a feed block method in which respective resin layers are merged on the upstream side of a die having a single flow path; a multi-manifold die in which a plurality of different flow paths are provided in the die and merged and discharged in the die before discharge. In the multi-manifold die system, a vane die system in which the shape of the flow path can be changed; a multi-slot system in which a plurality of lips are provided in a discharge portion of the die; The interlayer adhesion strength between the base material layer and the heat seal layer formed of the resin composition increases as the contact time between the base material layer and the heat seal layer in a molten state increases. Therefore, it is preferable to produce the composite film by the feed block method. When manufacturing a composite film by other methods such as a multi-manifold die method and a multi-slot method,
It is preferable to provide an interlayer adhesive layer between the base material layer and the heat seal layer.

The method for preparing the resin composition to be subjected to the film forming is not particularly limited, and may be a conventional method,
For example, a method generally called a dry blend method or a method called a master batch method can be adopted. The dry blending method is a method of mixing pellets of the copolyester (a) and the polycarbonate (b). The obtained mixture is directly subjected to a 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 produce pellets having a uniform composition.

The raw resin composition is preferably prepared by a master batch method. That is, according to the knowledge of the present inventor, when a raw material resin composition is prepared by the masterbatch method and analyzed by ¹³ C-NMR and ¹ H-NMR, the transesterification reaction of about 40 to 60% of the polycarbonate (b) is performed. Seems to have occurred. From this, it is presumed that polycarbonate (b) forms a block copolymer with copolyester (a). Also,
As described above, the reason why the heat seal strength is exhibited below the original heat seal temperature of the copolyester is presumed to be due to this transesterification reaction.

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

Since the film of the present invention exhibits a large mechanical strength even in a non-stretched state, a stretching treatment is not always necessary. However, if necessary, the whole film may be uniaxially or biaxially stretched.

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 the dry lamination strength between the heat-sealing film of the present invention and the base film is improved.

Further, on the surface of the film, a coating layer according to the intended use such as a gas barrier layer, an antistatic layer, a lubricating layer and the like may be formed.

The heat sealing temperature can be appropriately set according to 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
When the temperature exceeds 20 ° C., in a composite film in which the base material layer is stretched, the base material layer may be thermally contracted.

The film of the present invention has a wide variety of uses, for example,
It can be used as various films such as individual packaging of retort foods, interior and exterior packaging films, etc.

[0080]

The polyester resin composition of the present invention comprises:
It is useful for obtaining a film exhibiting high heat resistance and heat sealability despite being a polyester.

The heat-sealing film of the present invention is tasteless and odorless, and has excellent heat-sealing properties 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 substrate layer is not stretched.

[0083]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments.

Example 1 50 mol% of dicarboxylic acid having a ratio of terephthalic acid / isophthalic acid = 87.5 / 12.5 (molar ratio),
Copolyester 80 with 50 mol% of 4-butanediol
Parts by weight and bisphenol A type polycarbonate 2
0 parts by weight were previously melt-mixed to obtain a master batch having a uniform composition. This masterbatch was formed by an ordinary T-die extruder to obtain a single-layer 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 50 mol% of 4-butanediol
Parts by weight and bisphenol A type polycarbonate 2
0 parts by weight of the pellets are dry blended, and L / D = 28
And extruded with a conventional T-die extruder to obtain a single-layer film having a thickness of 40 μm.

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

Example 4 50 mol% of dicarboxylic acid having a ratio of terephthalic acid / isophthalic acid = 80.0 / 20.0 (molar ratio),
Copolyester 80 with 50 mol% of 4-butanediol
Parts by weight and bisphenol A type polycarbonate 2
Except for using 0 parts by weight, a thickness of 4
A monolayer film of 0 μm was obtained.

Example 5 50 mol% of terephthalic acid and 1,4-butanediol /
Diol 5 consisting of 2,2-bis (4-hydroxyethoxyphenyl) propane = 90/10 (molar ratio)
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 the copolyester with 0 mol% and 20 parts by weight of the bisphenol A type polycarbonate were used.

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

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

Example 8 Except that 60 parts by weight of the copolyester of Example 2 and 40 parts by weight of bisphenol A type polycarbonate were used,
In the same manner as in Example 1, a single-layer film having a thickness of 40 μm was obtained.

Comparative Example 1 50 mol% of 1,4-butanediol and 50 of terephthalic acid
Mol%, and the resulting polybutylene terephthalate was melt-mixed in advance to obtain a master batch. Example 1 without adding polycarbonate to this masterbatch
In the same manner as in the above, a single-layer film having a thickness of 40 μm was obtained.

Comparative Example 2 A monolayer 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 the polybutylene terephthalate of Comparative Example 1 and 20 parts by weight of the polycarbonate used in Example 1 were used.

Comparative Example 4 The copolyester obtained in Example 5 was treated in the same manner as in Example 1 without adding polycarbonate, to obtain a film having a film thickness of 40%.
A monolayer film of μm was obtained.

Comparative Example 5 A copolyester of 50 mol% of terephthalic acid and 50 mol% of a 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 single-layer film having a thickness of 40 μm.

Comparative Example 6 A copolyester of 50 mol% of ethylene glycol and 50 mol% of 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 single-layer 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. The copolyester was molded in the same manner as in Example 1 and the film thickness was 40
A monolayer film of μm was obtained.

Comparative Example 8 A diol 5 having a ratio of ethylene glycol / 1,4-cyclohexanedimethanol = 41/59 (molar ratio)
A copolyester of 0 mol% and 50 mol% of 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 single-layer film having a thickness of 40 μm.

The heat sealability, heat resistance and elongation at break of the single-layer 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 sealability: The films obtained in Examples 1 to 8 and Comparative Examples 1 to 8 were laminated with a stretched polyethylene terephthalate film (film thickness: 12 μm) using an isocyanate-based dry laminating agent. The resultant composite film was heat-sealed from the polyethylene terephthalate film side.

The heat sealing conditions were at four levels of temperature (140
℃, 160 ℃, 180 ℃, 200 ℃), pressure 1kg / c
m ² , time 1 second. The measurement of the heat seal strength was performed under the 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 up to the break 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 drier, heat-treated at a temperature of 120 ° C. for 30 minutes, and the change in haze before and after the heat treatment was measured in accordance with JIS 7105. The degree of whitening was visually determined based on the following criteria.

Excellent: Almost no change is observed Good: Slight change is observed but no problem in practical use Acceptable: High whitening degree has practical problem Impossible: Remarkably whitened and has practically significant problem Elongation: Based on JIS Z1707. However, the tensile speed was 100 mm / min. Sample shape is JI
It conformed to SZ1702.

Tables 1 and 2 show the compositions of the heat seal layers in the films of Examples and Comparative Examples. 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, heat sealability, heat resistance and elongation at break of each film.

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, 4
-Cyclohexanedimethanol, TFA stands for terephthalic acid, IFA stands for isophthalic acid.

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

Further, a diagram showing the correlation between the heat seal temperature dependence of the 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 other than the examples having heat sealability are inferior in heat resistance, and those having excellent heat resistance are inferior in heat sealability. Further, the film of the comparative example has a large whitening degree as a whole.

Example 9 Ethylene vinyl acetate copolymer obtained by graft copolymerization of maleic anhydride, which constitutes the resin composition, linear low-density polyethylene (LLDPE) and adhesive resin layer, as in Example 2 Was subjected to co-extrusion molding of three types and three layers by 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 an ordinary T-die extruder to obtain a monolayer film having a thickness of 100 to 110 μm. I 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 prepared as follows.

Each of the films obtained in Example 9 and Comparative Example 9 was extruded and laminated with aluminum (Al, 9 μm) via an ethylene-ethyl acrylate copolymer (EEA).

[0118] Thin film (50 g / m ² )
After extrusion lamination through EEA, the film obtained in Example 9 or Comparative Example 9 was dry-laminated on the outer surface.

The layer structure of the obtained film is as follows: in the composite film using the film of Example 9, (inner layer side) heat seal layer / adhesive resin layer / LLDPE / EEA / Al /
Comparative Example 9: EEA / thin paper / dry laminate layer / LLDPE / adhesive resin layer / heat seal layer (outer layer side)
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 film thickness of the multilayer film for a laminate tube was 350 to 380 µm.

The obtained multilayer film was slit into a width of 100 mm, rounded into a cylindrical shape, and the ends were ultrasonically sealed. Ultrasonic sealing is 500W, sealing time 0.5 seconds, pressure 2
The test was performed under the condition of kg / cm ² . The width of the seal is 10m
m. A cap was attached to one open end of the cylindrical tube, and the other open end was ultrasonically sealed in the same manner as described above to obtain a laminate tube having a length of 200 mm.

[0121] 300 ml of l-menthol was sealed in the laminate tube, and left for 500 hours in an environment of 40 ° C and 90% RH. After that, EEA / A on the inner layer side
A peeled edge was formed between the two samples, and the laminate (extruded laminate) strength was measured. Table 5 shows the results.

[0122]

[Table 5] Example 10 The same resin composition as in Example 2 and nylon 6 (Ny-
6) and a 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 co-extruded. The layer composition of the obtained composite film is Ny-
6 / EVOH / adhesive resin layer / heat seal layer = 60μ
m / 20 μm / 10 μm / 30 μm, and the total film thickness is 1
It was 20 μm.

Comparative Example 10 The procedure of Example 2 was repeated except that an ethylene-vinyl acetate copolymer having a vinyl acetate content of 5 mol% (EVA, melt viscosity 2.3 g / 10 min) was used instead of the resin composition of Example 2. In the same manner as in Example 10, the layer configuration was 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 thickness of 120 μm was prepared.

Then, the films obtained in Example 10 and Comparative Example 10 were heated using a vacuum molding machine (manufactured by Shin-Daigo Co., Ltd.) at an upper heater temperature of 180 ° C. and a pre-heating time of 0.1 mm.
Vacuum pressure forming was performed for 5 seconds under a pressure of 2.5 kg / cm ² . The mold 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 was heat-sealed as follows. For the container of Example 10, a film made of O-Ny (15 μm) and a resin composition prepared in the same manner as in Example 4 (20 μm) as a lid material.
And heat-sealed using a laminated film of In addition, for the container of Comparative Example 10, as a lid material,
Using a film obtained by laminating O-Ny (15 μm) and the EVA film (20 μm) used in Comparative Example 10, heat sealing was performed. Heat sealing at a temperature of 16
The test was performed under the conditions of 0 ° C., a pressure of 2 kg / cm ² , and a time of 1 second.

The container filled with pure water was subjected to a boil treatment at 80 ° C. for 30 minutes. Immediately after that, the container was opened and subjected to a sensory test by 10 panelists. All were determined to be odorless. On the other hand, in the container using the film of Comparative Example 10, six persons judged that there was an olefin smell.

Example 11 An ethylene-vinyl acetate copolymer obtained by graft copolymerizing maleic anhydride and an ethylene-vinyl acetate copolymer constituting the adhesive resin layer (2) and the same resin composition as in Example 2 were used. A polymer saponified product (EVOH), a modified polypropylene obtained by graft copolymerization of maleic anhydride, which constitutes the adhesive resin layer (1), and a polypropylene (PP) are co-extruded,
A thick composite sheet to be used for forming a container was prepared.

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 was 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 thickness of about 1 mm was prepared.

The thick multilayer sheet obtained in Example 11 and Comparative Example 11 was combined with a heater-moving vacuum-pressure-pneumatic plug-assist molding machine (VAS-33, manufactured by Senba Tekko Co., Ltd.).
P, using a mold squeezing pressure of 10 t) to perform a vacuum pressurized air plug assist molding to produce a molded container. The dimensions of the mold are 90 mm in diameter, 60 mm in bottom diameter, and 67.5 mm in depth.
The molding timing chart shows the heater back time 2
Seconds, the plug movement 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.
The test was performed at 5 kg / cm ² + vacuum.

For the obtained molded product, transparency, uneven thickness,
The four items of surface roughness and gloss were evaluated. Transparency was evaluated using a haze meter, and uneven thickness was measured by measuring the film thickness of the body. The surface roughness is visually determined,
The gloss was evaluated using a gloss meter. Table 6 shows the results
Shown in

[0132]

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

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

A molded product in which pure water was sealed was heated at a temperature of 110 ° C.
After a retort treatment 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 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, eight persons determined that there was an olefin odor.

Example 12 The same resin composition as in Example 2 was applied to paper (100 g / m ² ).
Extruded and laminated. The layer configuration is a paper / heat seal layer (30 μm).

Comparative Example 12 A stretched polyethylene terephthalate film (PET, 3
0 μm) was dry-laminated on paper (100 g / m ² ).

Comparative Example 13 Polyethylene (PE) was applied to a paper (100
g / m ² ).

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

[0139]

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

The resulting heat-sealed bag was heated at 40 ° C., 90
% RH for 500 hours. Thereafter, 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 lamination (extrusion lamination) strength was measured. The results are shown in Table 5 above.

Example 13 Example 11 was repeated using polypropylene instead of the resin composition of Example 2 and adhesive resin (1) instead of adhesive resin (2).
In the same manner as above, the PP layer / adhesive resin layer (1) / EVOH /
A co-extruded multi-layer sheet (total film thickness of about 1 mm) of five layers of three types 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 configuration 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 layer structure used in Example 13 was PP layer / adhesive resin layer
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 subjected to vacuum pressurized air plug assist molding according to Example 11 and Comparative Example 11. Then, the lid material prepared in Example 10 was used for the molded product using the multilayer sheet of Example 13, and the lid material prepared in Comparative Example 10 was used for the molded product using the multilayer sheet of Comparative Example 14. A molded product in which pure water was sealed was produced in the same manner as in Example 10. An odorlessness test was carried out in the same manner as in Example 10 except for boiling at a temperature of 80 ° C for a time of 40 minutes. As a result, in the container using the multilayer sheet of Example 13, all 10 persons were judged to be odorless. On the contrary,
In the container using the multilayer sheet of Comparative Example 14, seven persons judged that there was an olefin smell.

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

Comparative Example 15 A film was obtained in the same manner as in Example 2 except that a film (40 μm) obtained by subjecting a low-density polyethylene resin (LDPE) to ordinary T-die extrusion was used instead of the single-layer film obtained in Example 2. As in Example 14, the layer configuration was PET / Al / LDPE
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 filled with pure water was prepared.
When subjected to a retort treatment at 40 ° C. for 40 minutes, and immediately after the retort treatment, an odorlessness test was conducted in the same manner as in Example 10. In the bag using the film of Example 14, all 10 persons were judged to be odorless. did. On the other hand, in the bag using the film of Comparative Example 15, six persons determined that there was an olefin smell.

Comparative Example 16 A PET / Al / heat-sealing layer was formed in the same manner as in Example 14, except that the film obtained in Comparative Example 6 was used instead of the single-layer film obtained in Example 2. 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 top-surface heating type heat sealing tester. Table 7 shows the results of the heat sealing strength.

Comparative Example 17 A PET / Al / heat-sealing layer was formed 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. Was obtained.

The films obtained in Example 14 and Comparative Example 17 were heat-sealed in the same manner as in Comparative Example 16. Table 7 shows the results of the heat sealing strength.

Further, the films of Example 14 and Comparative Example 17 were heat-sealed in the same manner as described above,
A 200 mm × 150 mm four-sided sealed bag enclosing 50 ml was prepared and retorted at a temperature of 121 ° C. for 40 minutes.

In the four-side sealed bag of Example 14, no change was recognized even by the retort treatment.
The four-sided seal bag 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-acrylate copolymer to a dried film thickness of 2 to 3 μm.
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 KON / heat seal layer structure.

Comparative Example 18 The procedure of Example 15 was repeated except that a heat-sealing film (Toray Gosei Co., Ltd., Trefan NOT3931, film thickness 60 μm) was used instead of the monolayer film obtained in Example 2. In the same manner, a film having a layer configuration of 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 performed under the conditions of ² to prepare a 150 mm × 250 mm four-side seal bag in which 200 ml of pure water was sealed. The width of the heat seal portion was 10 mm. The obtained four-sided heat-sealed bag was subjected to a retort treatment at a temperature of 110 ° C. for a time of 20 minutes, and was subjected to an odorless test in the same manner as in Example 10 and Comparative Example 10. As a result, a bag using the film of Example 15 was obtained. Then, all 10 persons determined that there was no odor. On the other hand, in the bag using the film of Comparative Example 18, 6
One determined that there was an olefin odor.

In the same manner as described above, 50 ml of pure water was sealed in 50 ml of white rice (washed), and
A retort treatment was performed under the conditions of 1 ° C. and a time period of 40 minutes, white rice was cooked, and an odorless sensory test was conducted by 10 panelists.
All 0 persons were determined to be odorless. On the other hand, Comparative Example 18
In the bag using the film No. 8, eight persons judged that there was an olefin smell.

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

Comparative Example 19 The layer structure was changed to LDP in the same manner as in Example 16 except that a film (40 μm) made of low-density polyethylene (LDPE) was used instead of the single-layer film obtained in Example 2.
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, a bottom surface of 100 × 100 mm and a height of 150 m
m (excluding the roof) was prepared. The end 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 were as follows: temperature 190 ° C., pressure 2 kg / cm ² , time 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 sealed in a paper top paper container. The temperature of the fresh orange juice at the time of encapsulation was about 80 ° C. Then, the adsorption amount of the film to d-limonene was examined. In other words, a glass top paper container filled with fresh orange juice
After leaving 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 contents of the film was measured by gas chromatography. Table 8 shows the results.

[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 single-layer film obtained in Example 2.
In the same manner as in No. 6, a film having a layer constitution of LDPE / paper / EEA / heat seal layer was obtained.

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

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
Angstrom vacuum deposited film (VM-PE
T) was dry-laminated. The monolayer film obtained in Example 2 was dry-laminated on the obtained dry laminated film, and the layer configuration was OPP layer / VM-
A composite film of PET layer / heat seal layer 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., Trefane T393)
A film having a layer configuration of OPP / VM-PET / CPP was obtained in the same manner as in Example 17 except that (1, 60 μm) was used.

Incidentally, the film having such a layer structure is often used as a transparent high-temperature and high-pressure sterilization bag.

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

The obtained four-sided heat-sealed bag was used in Example 9
In the same manner as in Comparative Example 9, the substrate was left for 250 hours in an environment at a temperature of 40 ° C. and a humidity of 90% RH. Thereafter, a peeling start end was formed between the VM-PET layer and the heat seal layer, and the laminate strength was measured. Table 5 shows the results.

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

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 instead of the monolayer film having a thickness of 60 μm used in Example 18. And the layer configuration is LDPE (40 μm) / KON / L
A film of DPE (100 μm) / EVA was obtained.

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

Each of the films of Example 18 and Comparative Example 22 was formed into a four-sided heat-sealed bag 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 the bag was left under an environment of a temperature of 40 ° C. and a humidity of 90 RH% for 250 hours, Example 10 and Comparative Example 1 were obtained.
When the odorlessness test was performed by 10 panelists in the same manner as in the case of 0, the bag using the film of Example 18 had 10 odors.
All of the persons were judged to be odorless. On the other hand, in the bag using the film of Comparative Example 22, seven persons determined that there was an olefin smell.

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 configuration is cloud paper / heat seal layer.

Comparative Example 23 Low-density polyethylene (LDPE) film (20 μm)
Was dry-laminated with cloud paper (20 g / m ² ). The film having such a layer configuration is used for packaging Japanese confectionery 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.
To prepare a 50 × 50 mm square heat seal bag. The four-sided heat seal bag was filled with 100 mg of lemon flavor. The four-sided heat seal bag was left in an environment at a temperature of 40 ° C. and a humidity of 90% RH, and the time required for the scent to leak was measured. Table 9 shows the results.

[0176]

[Table 9] Example 20 Cellophane (KT, 26 μm) coated with a vinylidene chloride copolymer (PVDC), a biaxially stretched nylon 6 film (O-Ny, 15 μm), and the single-layer film 40 μm obtained in Example 2 Was subjected to dry lamination to obtain a composite film having a layer configuration of KT / O-Ny / heat seal layer.

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

In Example 20 and Comparative Example 24, defects were generated by scribing the KT PVDC layer before lamination.

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 subjected to a temperature of 160 ° C., a time of 1 second, and a pressure of 1 kg / cm ^2.
To form a 150 × 150 mm square heat seal bag. In the four-sided heat-sealed bag, squid salted and l-menthol were sealed. The four-sided heat seal bag was left in an environment at a temperature of 40 ° C. and a humidity of 90% RH, and the time required for the scent to leak was measured. Table 9 shows the results.
It writes in.

Further, 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 the film of Comparative Example 24. This is effective for high-grade miso applications and the like. Further, when the film of Example 20 is used, a high barrier property can be secured even when the PVDC surface of KT is damaged.

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

Comparative Example 25 In the same manner as in Example 21 except that a film (40 μm) made of low-density polyethylene (LDPE) was used instead of the monolayer film obtained in Example 3,
A composite film of EEA / Al / heat seal layer was obtained.

Incidentally, the film having such a layer structure is generally used for packaging of sheep and the like.

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

The films of Example 21 and Comparative Example 25 were heat-sealed at a temperature of 190 ° C., for 1 second, and at a pressure of 1 kg / cm ² , to produce a 150 × 150 mm square heat seal bag. The soft aluminum constituting the films of Example 21 and Comparative Example 25 was intentionally provided with about 150 pinholes. 50g of matcha powder is sealed in a four-sided heat seal bag, temperature is 40 ℃, humidity is 90%
It was left in an 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 was used, even if a pinhole was formed in the Al thin film, the scent was not scattered.

Example 22 A biaxially stretched nylon 6 film (O-Ny, 18 μm) was coated with a vinylidene chloride-vinyl acetate copolymer having a 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 the other side, 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 single-layer film obtained in Example 1 constitutes a heat seal layer (1), and the single-layer film obtained in Example 2 constitutes a 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 in place of the monolayer film obtained in Example 2. -In the same manner as in Example 22 except that a film (40 µm) made of vinyl acetate copolymer (EVA) was used,
A composite film having a layer structure of heat seal layer (1) / KON / heat seal layer (2) was obtained.

The film having such a layer structure is often used as a sticky packaging of a transparent liquid.
The heat-sealing method is a so-called sealing method in which the inner and outer surfaces are heat-sealed.

The films of Example 22 and Comparative Example 26 were prepared with a width of 3
It was slit to 0 mm, rolled into a tube, and heat-sealed at the ends. At that time, each of the films was processed so that the heat seal layer (2) was located on the inner surface of the tube.
Heat sealing was performed only from the outside, and the heat sealing conditions were as follows: temperature 160 ° C., time 0.5 second, pressure 2 kg /
cm ² . The width of the heat-sealed portion was 5 mm, and the dimensions of the stick were 12 mm × 100 mm.

When the obtained tube was filled with a liquid by a filling machine, the film of Comparative Example 26 was meandered in a line by the filling machine, but the film of Example 22 could be smoothly filled without meandering. It is estimated that the reason for this is that the film of Example 22 has higher rigidity than the film of Comparative Example 26. A measure of rigidity,
Table 11 shows the tensile modulus values. The modulus of elasticity is determined by JI
It was measured according to SZ1707.

[0194]

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

Example 23 The same resin composition as in Example 2, an impact-resistant polystyrene (HIPS), and an ethylene-vinyl acetate copolymer resin, which constitutes an adhesive resin layer and which is obtained by graft copolymerizing maleic anhydride, were used. Was co-extruded. The layer composition of the obtained composite film was HIPS layer / adhesive resin layer / heat seal layer = 2
00 μm / 20 μm / 180 μm, and the total film thickness is 40 μm / 20 μm / 180 μm.
It was 0 μm.

Comparative Example 27 The layer structure was changed to HIPS layer / adhesive resin layer / LDPE in the same manner as in Example 23 except that low density polyethylene (LDPE) was used instead of the resin composition similar to that in Example 2. A composite film of 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-pneumatic plug assist molding in the same manner as in Example 11 and Comparative Example 11, to produce a container.

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

The unevenness of the thickness of the obtained vacuum-pressure-pneumatic plug-assist molded product was evaluated in the same manner as in Example 11 and Comparative Example 11, and it was 250 to 260 μm. Even when the film of Example 23 was used, the moldability was not changed as compared with the film of Example 11.

Further, 50 ml of l-menthol was sealed in a vacuum-pressure-pneumatic plug-assisted molded product in the same manner as in Example 10 and Comparative Example 10 using the lid material prepared in Example 10 and Comparative Example 10, and the temperature was 40 ° C. And the humidity was kept at 50% RH, and the time until 1-menthol leaked was measured. Table 9 shows the results.

Example 24 A composite film using the same resin composition as in Example 1 and a heat-sealing layer and using polybutylene terephthalate (PBT) as a base layer (heat-resistant resin layer) was produced as follows. That is, silica fine powder having an average particle size of 5 to 10 μm
By using a multi-manifold die using a different extruder, the same resin composition as in Example 1 containing 1 wt% and PBT were used to prepare a coextruded composite film of two types and two layers. The layer composition 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 μm.
It was 0 μm.

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

Examples 25 to 30 In place of the resin composition used in Example 24, the average particle size was 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 Each of these composite films has a layer configuration of PBT layer / heat seal layer = about 30 μm / about 40 μm, and the total film thickness is It is 80 to 70 μm. In these examples,
The adhesive resin that bonds the PBT layer and the heat seal layer is
It was not necessary.

The heat-sealed 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, and the heat-sealing strength and the elongation at break were measured. did. Table 12 shows the results.

[0206]

[Table 12] As is clear from Table 12, the composite films of Examples 24 to 30 have not only high heat seal strength but also high elongation at break even without being stretched. Table 3
As is clear from the comparison with Examples 4 and 4, the elongation at break is larger than the single-layer 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 surface of the PBT layer to obtain composite films.

Example 31: Uniaxially stretched polypropylene film (OPP, 20 μm) Example 32: Biaxially stretched polypropylene film (OP
Example 33: Biaxially stretched OPP film coated with a vinylidene chloride-based copolymer to a dried film thickness of 2 to 3 µm (KOP) Example 34: Biaxially stretched polyethylene terephthalate film (PET, 12 µm) Example 35: Biaxially stretched PET film coated with a vinylidene chloride-based copolymer to a thickness of 2 to 3 μm after drying (K-PET) Example 36: Biaxially stretched nylon 6 film (O-Ny,
Example 37: Film in which a biaxially stretched O-Ny film is coated with a vinylidene chloride-based copolymer to a thickness of 2 to 3 μm after drying (KON) Heat sealing of the composite film obtained in Examples 31 to 37 The surfaces were measured for heat seal strength and elongation at break in the same manner as described above. Table 13 shows the results.

[0209]

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

Examples 38 to 40 The resin composition used in Example 2, polybutylene terephthalate (PBT), and an ethylene-vinyl acetate copolymer obtained by graft copolymerizing maleic anhydride to constitute an adhesive resin layer And the following polymer were subjected to coextrusion molding to obtain a composite film having a layer configuration 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 seal surfaces of the composite films obtained in Examples 38 to 40 were In the same manner as in the above, the heat seal strength and the breaking elongation were measured. Table 14 shows the results.

[0212]

[Table 14] As is clear from Table 14, the composite films of Examples 38 to 40 have not only high heat seal strength but also high elongation at break even without being stretched.

Examples 41 to 43 Instead of the polycarbonate used in Example 2, polycarbonate having a different molecular weight [manufactured by Mitsubishi Gas Chemical Co., Ltd .;
1000; molecular weight 10,000] (Example 41), polycarbonate [M-Gas Chemical Co., Ltd., E-2000; molecular weight 20,000] (Example 42), polycarbonate [Mitsubishi Gas Chemical Co., Ltd., S-3000]; molecular weight 300
00] A mixture having the same plastic ratio as in Example 2 was prepared except that (Example 43) was used, and a single-layer film having a thickness of 40 µm was obtained in the same manner as in Example 2.

Each of the obtained films exhibited the same heat seal strength, whitening degree and breaking elongation as those of the single-layer film obtained in Example 2.

[Brief description of the drawings]

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

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C08L 69/00 C08L 69/00 // B29K 67:00 B29L 7:00 C08L 67:00 69:00 (56) References JP JP-A-61-136549 (JP, A) JP-A-62-252419 (JP, A) JP-A-63-63718 (JP, A) JP-A-63-210124 (JP, A) JP-A-53-94537 (JP, A) JP-A-57-39928 (JP, A) JP-A-49-29377 (JP, A) JP-A-60-1001028 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) C08J 5/18 CFD C08L 67/02 C08L 69/00 B32B 27/10

Claims (12)

(57) [Claims] (1) (a) selected from aliphatic diols, alicyclic diols and aromatic diols , and
Two or more diol components including an aliphatic C _4-6 diol ,
Derived from terephthalic acid and having a melting point of 150 to 21
A polyester resin composition comprising a copolyester in the range of 0 ° C. and (b) polycarbonate ,
The ratio of the aliphatic C _4-6 diol to another diol is
Aliphatic C _4-6 diol / other diol = 50-90 / 5
0 to 10 (molar ratio) and substantially poly (1,4
-Butylene terephthalate) free polyester
Resin composition . 2. A method according to claim 1, wherein (a) an aliphatic C _4-6 diol and
From two or more dicarboxylic acids including terephthalic acid
Induced and having a melting point in the range of 150 to 210 ° C
Polyester including polyester and (b) polycarbonate
An ester-based resin composition comprising: (a) a copolyester
Or 70-90% by weight, and (b) polycarbonate
Or 30 to 10% by weight and substantially poly
Polyester not containing (1,4-butylene terephthalate)
Steal resin composition. 3. A process according to claim 1 or 2 polyester resin composition according aliphatic C _4-6 diol is 1,4-butanediol. Wherein the diol component is 1,4-butanediol and 2,2-bis (4-hydroxyethoxy-phenyl) polyester resin composition according to claim 1, wherein the propane. 5. A copolyester, and 50 mol% di-ol component, a polyester resin composition according to claim 1, wherein the copolyester of 50 mole% terephthalic acid. 6. The method of claim 1, wherein the copolyester is 1,4-butanegio.
Lumpur 50 mol% and terephthalic acid / other dicarboxylic acids =
The polyester resin composition according to claim 2, which is a polyester copolymerized with 50 mol% of a dicarboxylic acid component having a ratio of 5 to 95/95 to 5 (molar ratio). 7. The polycarbonate is represented by the following general formula [V]: 3. The polyester resin according to claim 1, wherein the polyester resin has a repeating unit represented by the formula: wherein R ₈ and R ₉ are the same or different and each represent a hydrogen atom, a lower alkyl group, a cycloalkyl group, or an aryl group. Composition. 8. A film having a heat sealing property, which is formed in the claims 1 or 2 polyester resin composition. 9. The heat-sealing film according to claim 8 , 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 or 2. . 10. The heat-sealing film according to claim 9 , wherein the base material layer contains at least a heat-resistant resin layer. 11. substrate layer, a heat-resistant resin layer, an olefin polymer, polyester, and claims is composed of has been a polymer selected from nylon polymer 9
A film having the heat-sealing property described above. 12. The heat-sealing film according to claim 10 , wherein the heat-resistant resin layer is a polybutylene terephthalate layer.