JP2003136627A - Biaxially oriented polyester laminated film and method for manufacturing the polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester laminated film which shows a compatibility between outstanding straight ripping properties and high impact strength, while retaining a dimensional stability under heat and moisture environments and also extremely high gas barrier properties. SOLUTION: The laminated biaxially oriented polyester film is constituted of an oxide-vapor deposited layer laminated on one of the sides of the biaxially oriented polyester film which shows an impact strength of 450 J/cm or more and straight ripping properties in the flow direction of a machine. In addition, the polyester film is characterized in that it satisfies the following conditions: (1) haze <=8%, (2) moisture permeability <= 20 g/m<2> ./24 hr (40 deg.C/90%RH) and (3) oxgen permeability <= 100 cc/m<2> .24 hr.atm (25 deg.C/50%RH).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to excellent tear straightness, excellent gas barrier property, transparency, excellent strength, heat resistance,
It has dimensional stability and is useful as a constituent material for packaging of foods such as confectionery, pickles, miso, soups, jams, frozen, refrigerated, and retort pouches, and especially medical and medical fields such as pharmaceuticals and cosmetics. About the film

[0002]

2. Description of the Related Art Packaging bags made of various plastic films are often used for packaging foods and pharmaceuticals.
A packaging bag in which two or three or more layers of a biaxially stretched plastic film and a heat-sealable non-oriented plastic film are laminated is widely used. Biaxially stretched polyester film has excellent durability, moisture resistance, mechanical strength, heat resistance, and oil resistance, and is manufactured using tubular method, flat simultaneous biaxial stretching method, flat sequential biaxial stretching method, etc. The biaxially stretched polyester film is widely used in the food packaging field.

However, the packaging bag using the biaxially stretched polyester film has a problem of poor tearing and unsealing property. There is a method of giving a notch to improve the openability, but when it is torn from the notch, the phenomenon that it does not tear linearly often occurs, not only is the contents scattered and wasted, but also such as cookies. Soft confections may break when opened, and if the contents are liquid, it may stain clothes. Also, as a problem in the packaging of pharmaceuticals, if the sachets cannot be cut cleanly along the perforated lines, the medicines will be scattered to the outside, and the scene is extremely sad. In addition, when taking a powdered medicine, the shape of the opening mouth controls the flow of the medicine due to the convenience of dropping the medicine from the tear opening portion of the sachet into the mouth, and this influences the degree of squeezing afterwards. In the case of an elderly person, this may lead to a pessimistic feeling by re-recognizing old age and illness, and it has been desired that the tearing / opening portion after bag making should be torn linearly and neatly.

As an easily openable packaging material which is excellent in straightness when the film is torn, there is a laminate in which a uniaxially stretched polyolefin film is laminated as an intermediate layer. Examples of such materials include a three-layer laminated film of biaxially stretched polyester film / uniaxially stretched polyolefin film / unstretched polyolefin film,
Since an intermediate layer has to be provided purposefully, there is a problem in cost and the use is limited. Due to such circumstances, there is a demand for a polyester film which is excellent in tearing straightness even with a single layer, but there are some problems in its development.

As a problem in use, conventional polyester films excellent in straightness of tearing have low impact strength and may break during handling when used as a retort bag, which is a problem in practical use. It was As a manufacturing problem, such polyester film develops tear straightness by utilizing the anisotropy of the phase separation structure of the polymer blend. In order to control the anisotropy of this film, for example, Japanese Unexamined Patent Publication No. 08-169962 defines anisotropy in an unstretched sheet. However, until the film is completed, there are further stretching, relaxation treatment, heat setting, etc., so the anisotropy will change depending on the process to be experienced after that, and finally control to the desired anisotropy. Was difficult.

Further, in order to develop a phase-separated structure by a polymer blend, it is common to melt-mix two kinds of polyester chips. In this case, when the large-scale melt-mixing or the recovered raw material is used, the polyester composition is The thermal stability of the product decreases. In particular, there is a problem that the straightness of tearing is deteriorated due to the transesterification reaction that occurs between the mixed polyesters.

On the other hand, for long-term storage packaging, the gas barrier property is an important characteristic except for some applications where breathable packaging is required. Especially those whose main purpose is to prevent moisture, such as dry foods, dried foods, baked goods, candy, powdered foods, powders, capsules, etc., and those whose main purpose is to prevent oxidation, such as oil-prepared foods and pharmaceuticals in general. It is often the case that water vapor barrier properties and oxygen barrier properties are required for each, and their combined performance is required. Above all, 25 for pharmaceuticals
Some of them are required to be stored for 3 years at a temperature of 60 ° C and RH of 60%, so that a very high level of gas barrier property is necessary. Therefore, the conventional gas barrier method such as vinylidene chloride coating method or polyvinyl alcohol coating method is insufficient, and the requirement of high oxygen barrier property under high humidity could not be satisfied.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve such problems, and is a characteristic of biaxially stretched polyester film, which is mechanical properties, aroma retention, heat resistance, oil resistance, and low resistance. While maintaining hygroscopicity, transparency, and dimensional stability under dry heat and wet heat environments, which are particularly required for food and pharmaceutical packaging materials, both excellent tear straightness and impact strength are achieved, and in addition, gas barrier property It is intended to provide an extremely high biaxially stretched polyester laminated film. Furthermore,
Provide a gas barrier biaxially stretched polyester laminated film having excellent tear straightness, which is small in the transesterification reaction even under the production conditions that undergo severe heat history and which is suitable for a wide range of production conditions. It is what

[0009]

The present inventors have arrived at the present invention as a result of extensive studies to solve such problems. That is, the gist of the present invention is that the impact strength is 450 J / c.
A vapor-deposited layer of oxide is laminated on at least one surface of a biaxially oriented polyester film having a length of m or more and excellent in tear straightness in the machine direction, and the following (1) to
A laminated biaxially oriented polyester film which satisfies the condition (3). (L) Haze value ≦ 8% (2) Water vapor transmission rate ≦ 20 g / m ² · 24 hr (40 ° C./90
% RH) (3) Oxygen permeability ≦ 100 cc / m ² · 24 hr · at
m (25 ° C / 50% RH)

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the polyester composition constituting the base material layer of the laminated film of the present invention, the crystalline polyester (A) is a polyester having ethylene terephthalate as a main repeating unit, and polyethylene terephthalate (PET) is most suitable. However, a copolymer of PET and polybutylene terephthalate (PBT), a copolymer of PET and polyethylene naphthalate (PEN), or a mixture thereof can be used. The polyethylene terephthalate used preferably has an intrinsic viscosity of 0.60 dl / g or more, more preferably 0.62 dl / g or more 0.8 dl / g
The following are suitable: When an intrinsic viscosity of less than 0.60 dl / g is used, the impact strength is not excellent. If the one having an intrinsic viscosity of more than 0.8 dl / g is used, the extrusion moldability is poor. The method for polymerizing the crystalline polyester (A) is not particularly limited, but a solid phase polymerization method can be used together in order to bring the intrinsic viscosity into a suitable range.

In the block copolyester (B) of the present invention, the crystal segment having a melting point of 170 ° C. or higher has a melting point of 170 when the component alone is used as a polymer.
Residues of aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, and ethylene glycol, propylene glycol, butanediol, pentamethylene glycol, P-xylene glycol Polyesters having residues of aliphatic, aromatic or alicyclic diols such as cyclohexanedimethanol can be used, but it is particularly preferable that terephthalic acid residues account for 80 mol% or more. Further, the soft polyester having a molecular weight of 400 to 8,000 is one having a melting point or a softening point of 100 ° C. or less when measured only with the segment constituent components. Molecular weight is 40
When 0 or less is used, the resulting block copolyester has a low melting point and a large tackiness, and it becomes difficult to compound into a film. The molecular weight is 8000
If it exceeds, the soft polymer will undergo layer separation, exhibit extremely high melt viscosity, become hard and brittle, and will be difficult to take out from the polymerization vessel after the copolymerization reaction. When used for, it is not preferable because of poor transparency. Particularly preferably, it has a molecular weight of 800 to 4000.

The proportion of the low melting point soft polymer in the block copolymerized polyester is in the range of 1 to 12 mol%. If it is less than 1 mol%, the properties as a soft polymer cannot be obtained, and if it exceeds 12 mol%, the dispersion of the block copolymerized polyester (B) becomes large at the time of mixing and melting with the crystalline polyester (A), and the straightness of tearing is increased. Not obtained, and the transparency is also deteriorated. Particularly preferably, it is 3 to 8 mol%.

Examples of such low melting point soft polymers include polyethylene oxide glycol, polytetramethylene oxide glycol, polypropylene oxide glycol, copolymer glycols of ethylene oxide and propylene oxide, copolymer glycols of ethylene oxide and tetrahydrofuran, and the like. Examples thereof include aliphatic polyesters such as polyether, polyneopentyl azelate, polyneopentyl adipate, and polyneopentyl sepacate, and polylactones such as poly-ε-caprolactone and polypivalolactone. Preference is given to polyethylene oxide glycol, polytetramethylene oxide glycol and the like. These block copolymerized polyesters can be produced by a usual condensation polymerization method.

Specific examples of the block copolymer polyester used in the present invention include polyethylene terephthalate-polyethylene oxide block copolymer, polyethylene terephthalate-polytetramethylene oxide block copolymer, polybutylene terephthalate-polyethylene oxide block copolymer. , Polybutylene terephthalate-polytetramethylene oxide block copolymer, polyethylene terephthalate-polyethylene oxide, polypropylene oxide block copolymer, polytetramethylene terephthalate / isophthalate-polytetramethylene oxide block copolymer, polyethylene terephthalate-poly-ε -Caprolactone block copolymer, polybutylene terephthalate-poly-ε-caprola Kuton block copolymer, polyethylene terephthalate-polyneopentyl sepacate block copolymer, block copolymer of polyester with polyethylene glycol from di (4-carboxyphenoxy) ethane and ethylene glycol, bis (N-paracarbohydrate) For example, a block copolymer of a polyester made of ethoxyphenyl) adipamide and ethylene glycol and polyethylene glycol can be used.

In the present invention, when polyethylene terephthalate (a) and polybutylene terephthalate (b) are used as the polyester (A) group consisting of one or more crystalline polyester resins, polyethylene terephthalate (a) and Polybutylene terephthalate (b)
The mixing ratio of the block copolymer polyester (B) with the polyethylene terephthalate (a) is 90 to 70% by weight, and the sum of the polybutylene terephthalate (b) and the block copolymer polyester (B) is 10 to 30% by weight. It is necessary to blend, preferably polyethylene terephthalate (a) 90 to 75 wt% with polybutylene terephthalate (b) and block copolymerized polyester (B).
Of 10 to 25 wt%, more preferably 90 to 80 wt% of polyethylene terephthalate (a), polybutylene terephthalate (b) and block copolymerized polyester (B)
Is 10 to 20 wt%. The sum of polybutylene terephthalate (b) and block copolymerized polyester (B) is 1
If it is less than 0 wt%, tear straightness cannot be obtained. Also,
When the sum of the polybutylene terephthalate (b) and the block copolymerized polyester (B) exceeds 30 wt%, the biaxially stretched polyester film has low tensile strength or dimensional stability and rigidity, and cannot be used.

In the present invention, there is no particular limitation on the compounding ratio of the polybutylene terephthalate (b) and the block copolymerized polyester (B).

In the present invention, the compounding order of polyethylene terephthalate (a), polybutylene terephthalate (b) and block copolymerized polyester (B) is not particularly limited, but three kinds of resins are simultaneously mixed in a pellet state, Extrusion forms a suitable phase-separated structure for the polymer, which results in good tear straightness even after large-scale manufacturing processes with severe thermal history.

The impact strength of the biaxially stretched polyester film of the present invention needs to be 450 J / cm or more. 450 J / cm
If it is less than the above, the practical strength is insufficient, and when used as a packaging bag, the bag may be broken due to dropping and the like. 2 of the present invention
The heat shrinkage of the axially oriented polyester film is 150 ° C x 3
Machine flow direction (MD direction), width direction (T
Both in the D direction) are preferably 3% or less. If the heat shrinkage ratio exceeds 3%, printability is deteriorated, which is not preferable.

The haze of the biaxially stretched polyester film of the present invention is preferably 8% or less. If it exceeds 8%, the transparency of the film deteriorates and the commercial value is impaired. Ideally, 5% or less and 4% or less are ideal. The isotropic evaluation value of the biaxially oriented polyester film of the present invention is preferably 0.70 or less, more preferably 0.60 or less. When it was 0.30 or less, when the polyester (B) was 19% by weight, the warp width when tearing 200 mm was about ± 1 mm. Isotropic evaluation value is 0.70
If it exceeds, tearing straightness in the machine direction cannot be obtained.

As a method for making the isotropic evaluation value of the film 0.70 or less, in addition to using the above-mentioned polyester composition, for example, polyester (B) is used in a large amount by biaxial stretching. It was found that setting the stretching and heat-setting temperatures in a higher range is also effective.

Further, in the biaxially oriented polyester film of the present invention, when the transesterification rate <B> value is less than 0.07, it is easy to exhibit tear straightness, but the <B> value is less than 0. It is difficult to carry out large-scale melt-kneading for mass production while keeping the value less than 07, and it is common that the <B> value becomes 0.07 or more, and tear straightness is lost. Further, as the recovered raw material is used, the heat history repeatedly applied to the polyester composition becomes severe as in the case of the large-scale melt-kneading, and the tear straightness is lowered. In the present invention, the transesterification rate <B> value is 0.150.
When it is less than 0.1, it is preferable that the tear-progressing polyester film can be stably mass-produced, but it is more preferable that it is less than 0.100. Further, when it is less than 0.07, it is adapted to a wide range of manufacturing conditions, and it is effective for use as a recovered raw material for cost reduction and also for performance maintenance when the recovered raw material is used. As a method for reducing the transesterification rate <B> value to less than 0.150, less than 0.100, and further less than 0.070, use of, for example, a titanium-based catalyst as a catalyst when synthesizing the polyester and / or polyester ether used It can be realized by avoiding. However, it is also quite effective to add a transesterification inhibitor to the polyester composition used.

In producing the film of the present invention, addition of suitable additives such as antioxidants, antiblocking agents, ultraviolet absorbers and lubricants in advance does not cause any problems. In particular, the use of UV absorbers enhances the UV-cutting properties that aromatic polyesters inherently possess. Transparent vapor deposition ensures the visibility of the contents while gas blocking properties and UV-cutting properties prevent the deterioration and modification of pharmaceutical products. It can be said that it is a skillful means in that it can be suppressed for a long time.

As the transesterification inhibitor contained in the polyester composition used in the present invention, an organic phosphorus compound having at least one P—O bond in the molecule is preferably used. Examples of such substances include organic phosphorus ethers such as organic phosphites, organic phosphorus esters such as organic phosphates, and organic phosphorus ethers such as organic phosphine oxides. Specific examples of such compounds include aromatic phosphites such as triphenyl phosphite, aliphatic phosphites such as bis (acetadeca) pentaerythritol diphosphite, and bis (2,6-di-t- Butyl-4-methylphenyl) pentaerythritol, bis (2,4-dicumylphenyl) pentaerythritol diphosphite, 2-
[[2,4,8,10-Tetrakis (1,1-dimethylether) dibenzo [d, f] [1,2,3] dioxaphosphepin 6-yl] oxy] -N, N-bis [ 2-[[2,4,8,10-Tetrakis (1,1, dimethylel) dibenzo [[d, f] [1,3,2] dioxaphosphepin-6-yl] oxy] -ethyl] Ethanomin, aliphatic aromatic phosphite such as diphenylisodecyl phosphite, trimethyl phosphate, triethyl phosphate, tributyl phosphate, ethyl diethyl phosphonoacetate, benzyl ethyl phosphonate, di-2-ethylhexyl phosphate, tris (2-chloroethyl) phosphate, Examples thereof include organic phosphoric acid esters and the like.

The amount of the organophosphorus compound having at least one P—O bond in these molecules to be contained in the biaxially oriented polyester film is such that the amount of the organic phosphorus compound relative to the amount of metal [M] in the metal catalyst is [M]. [P] / [M] as the phosphorus amount [P] in the phosphorus compound is preferably in the range of 0.5 or more and 500 or less. If it is smaller than this range, the coordination efficiency of the metal with respect to the organic phosphorus compound is lowered, and the deactivation of the catalyst is insufficient. If it is larger than this range, the organic phosphorus compound acts plastically to deteriorate the physical properties of the film. Become. The method of adding the transesterification inhibitor contained in the polyester composition used in the present invention may be directly melt-mixed in a melt-extruder in a film manufacturing process, or may be melt-mixed with a raw material resin in advance. You may use what was converted.

As the method for forming the substrate film of the present invention, for example, a mixture of one or more types of crystalline polyester (A) and block copolymerized polyester (B) in a chip form is charged into an extruder, After being heated and melted, the sheet is extruded and discharged from the die orifice of the T die. At this time, the shear rate of the resin at the die orifice is preferably 200 sec-1 or more. When the shear rate is less than 200 sec-1, the isotropic evaluation value of the film is larger than 0.70, and the straight cut property cannot be obtained. Next, the softened sheet is tightly wound around the cooling drum and cooled. Then, the obtained unstretched sheet is 90-110.
Stretching is carried out at a temperature of ° C in the longitudinal direction at a stretch ratio of 3 to 4 times. Then, at a temperature of 80 to 110 ° C., a horizontal direction of 3.5 to
Stretch at a stretch ratio of 4.5 times. If the stretching ratio is lower than each temperature, a homogeneous stretched film may not be obtained, and if the stretching ratio exceeds each temperature, crystallization of the crystalline polyester (A) is promoted and the transparency is poor. May be. The biaxially stretched film is
Then, it heat-processes at the temperature of 210-250 degreeC. When the heat treatment temperature is lower than 210 ° C., the shrinkage rate of the film becomes large, which causes deformation when used as a bag.
On the other hand, if the temperature is higher than 250 ° C., the film melts and it becomes difficult to form a film. The biaxial stretching method is preferably a sequential biaxial stretching method using a roll and a tenter, and it is desirable to stretch in the longitudinal direction and then in the transverse direction. When the longitudinal stretching is performed after the lateral stretching, it is difficult to obtain straightness of tearing.

As described above, since the film of the present invention has a structure based on the technique described in, for example, JP-A-52-77189, the base film is bent, slid,
Resistant to heat and pressure deformation. Further, in the present invention, impact resistance and stable productivity are improved. In addition, JP-A-52-771
It has been shown that the base film described in 89 has a stronger adhesive force with the metal vapor deposition layer than the conventional film and enhances the gas barrier property. In the present invention, this effect was also taken into consideration, and as an extension of the technique, the following inorganic oxide vapor deposition was performed.

The biaxially oriented polyester film which is the base material of the vapor deposition layer of the present invention may be subjected to corona discharge treatment, coating treatment or flame treatment in order to improve adhesiveness and wettability depending on the use. In particular, before laminating the oxide vapor deposition layer on the film, the above-mentioned easy-adhesion coating treatment may be performed in advance in order to further enhance the adhesion between the film and the oxide vapor deposition layer.

The oxide vapor deposition layer constituting the present invention may be any oxide vapor deposition layer exhibiting the transparency and gas barrier properties which satisfy the above conditions (1) to (3). Non-metal oxides are widely used, but a vapor-deposited layer containing silicon oxide, aluminum oxide, or a mixture thereof as a main component is particularly preferable. The vapor-deposited layer of these oxides is suitable because it does not emit harmful substances even if it is discarded after use.

The film thickness of the oxide vapor deposition layer is usually 10 to 50.
00Å, more preferably 50 to 2000Å. If the film thickness is less than 10Å, it is difficult to obtain sufficient gas barrier property, and even if the film thickness exceeds 5000Å, the effect of improving the gas barrier property is saturated, resulting in poor bending resistance and manufacturing cost. Because it goes up, it is not practical.

In order to form the above-mentioned oxide vapor deposition layer, a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method, an ion plate method, or a chemical vapor deposition method such as CVD is appropriately used.
As the heating method used at this time, resistance heating, induction heating, electron beam heating or the like can be appropriately adopted. As a reactive gas, oxygen, nitrogen, hydrogen, argon, carbon dioxide, water vapor, etc. may be introduced, or a reactive vapor deposition method using means such as ozone addition or ion assist may be adopted, and a bias may be applied to the substrate. Alternatively, the film forming conditions such as heating and cooling of the substrate can be changed. Such deposition materials, reaction gas, substrate bias, heating / cooling conditions are determined by sputtering method, CD
The same change can be made when adopting the V method. Before or during the deposition of oxide, the adhesion strength of the oxide is improved by applying corona discharge treatment, flame treatment, low temperature plasma treatment, glow discharge treatment, reverse sputtering treatment, roughening treatment, etc. It is also effective to raise it further.

Such a vapor-deposited layer of the present invention maintains the gas barrier property even when the base film is deformed by 4% as described in, for example, Packaging Times No. 2041. Such a vapor deposition layer forming technique works extremely effectively when combined with the base film technique described in JP-A-52-77189, which is particularly resistant to deformation, has excellent vapor deposition layer adhesion, and is expected to enhance the gas barrier property.

The laminated biaxially oriented polyester film vapor-deposited with the oxide of the present invention may be further laminated with another film, sheet or the like. For example, a polyethylene-based or polypropylene-based sealant layer can be laminated on one side of the laminated film of the present invention as a heat-bonding layer for bag making. A nylon film can be laminated to give it toughness. Other semi-transparent metal foil, paper,
Etc. can be laminated to make bags.

Next, the present invention will be specifically described with reference to examples. The measuring methods in Examples and Comparative Examples are as follows.

(Measurement Method) Haze (Haze Value) The haze value was measured using a haze meter manufactured by Nippon Denshoku Co., Ltd. according to JIS-K6714.

The gas barrier oxygen permeation amount is measured by an oxygen permeation measuring device (“OX-TRAN”).
10 / 50A ") manufactured by Modern Controls Co., Ltd.), humidity 0%, temperature 25 ° C., purged for 2 days. In addition, the water vapor transmission rate is measured by a water vapor transmission rate measuring device (“PERMATRAN” Modern Control).
The temperature was 40 ° C., the humidity was 90%, and the purge was performed for 2 days.

Reduced viscosity and intrinsic viscosity: Using a Ubbelohde viscous tube, the sample was dissolved in a mixed solvent of phenol / tetrachloroethane in a weight ratio of 6/4 at a solution concentration of 0.4 g / dl and measured at a temperature of 30 ° C. The reduced viscosity is calculated from the value obtained and further converted to the intrinsic viscosity if necessary.

From the tear straight-moving biaxially oriented polyester film, 200 in the MD direction.
mm, a 40 mm strip-shaped film piece is cut out in the TD direction, and a sample having a 5 mm long cut in the center of one short side of this film piece is used as needed 10 or 30
Create a book. Next, tear by hand in the MD direction from the cut, and the tear propagation end reaches within 5 mm from the center of the short side facing the cut side ○ (especially when rating within 2 mm ◎ ) What was reached at 5 mm or more was marked with Δ, and those which did not reach the opposite short sides were marked with x. A schematic diagram is shown in FIG.

Isotropic Evaluation Portable Photoelectric Colorimeter (COLOR, manufactured by Shibata Chemical Equipment Co., Ltd.)
Using the IMETER MODEL C-2), remove the sample holder and disconnect the input line of the photodiode for light reception. The sensor surface of the visible light blue sensitive photodiode (BS120) has an elevation angle of 60 degrees from the center of the incident light diaphragm of the 5 mmφ colorimeter to the exit side of the incident optical axis.
Attach it at a position where the distance is 21 mm, and connect the signal output after disconnecting the photodiode input of the colorimeter. After completely removing the light leakage, the measurement is started. With the incident light (white light) blocked, adjust the 0% of the meter with the zero adjustment dial. 1 to 10 sample films (standard 2 to 5) are cut on a 5 mmφ incident light diaphragm of a colorimeter, and the cut-out directions are aligned and overlapped and fixed. At this time, the MD direction of the sample film is perpendicular to the plane including the optical axis and the center of the sensor. Apply 100% of the meter with the 100% adjustment dial. Next, the sample film is rotated 90 degrees around the incident light diaphragm so that the TD direction of the sample film is perpendicular to the plane including the optical axis and the center of the sensor, and the meter is read (a%). Rotate the film 90 degrees in the same direction and adjust to 100%, and read a% reading 5
Repeat times. Finally, remove the film, apply incident light and read the meter (B%). The average of 5 a% readings is A%
Then, the isotropic evaluation value: I is represented by I = (AB) / (100-B). The greater the anisotropy, the closer I becomes to 0.
I has a value closer to 1 as the anisotropy is smaller. When performing this evaluation method, the selection of devices is not limited to the above as long as they are optically equivalent and have similar sensitivities.

Impact Strength Using a film impact tester manufactured by Toyo Seiki Co., Ltd., the impact strength of the film was measured using a hemispherical impact head having a diameter of 1/2 inch.

Heat-shrinkage rate A strip sample having marked lines in the MD direction and TD direction of the film was cut out and treated in an oven at 150 ° C for 30 minutes, and the dimension between marked lines after treatment was 23 ° C, 65%. It was measured at RH equilibrium. The amount of shrinkage due to the treatment is shown as a percentage of the size before treatment.

Transesterification rate <B> value 700 mg of a polyester film sample was dissolved in a deuterated trifluoroacetic acid solvent, and UNITY-500 manufactured by Varian
13C-NMR spectrum is measured at room temperature using (125 MHz). In the obtained chart, the peak integrated intensity Ia (at 135.6 ppm) derived from the carbons at the 1st and 4th positions in the terephthalic acid unit bonded only to the ethylene glycol unit. Peak integrated intensity Ib (at 135.9 ppm) derived from carbons at the 1st and 4th positions in the terephthalic acid unit bonded only to the butanediol unit. Of the carbons at the 1-position and 4-position of the terephthalic acid unit bonded to both the ethylene glycol unit and the butanediol unit, the peak integrated intensity Id (in 136. 1ppm)
And the transesterification rate <B> value is expressed by the following equation. <B> = {Id / (Ia + Id)} + {Id / (Ib + Id)} ... Equation 1

Example 1-1 Polyethylene terephthalate [SR553 (intrinsic viscosity 0.75 dl / g) manufactured by Toyobo Co., Ltd.] was used as the crystalline polyester (A), and the dicarboxylic acid component was used as the block copolymerized polyester (B). As a mixture of copolymerized PBT (reduced viscosity 1.33 dl / g) consisting of 100 mol% of terephthalic acid, 96.7 mol% of butanediol as a diol component and 3.3 mol% of polytetramethylene glycol at a ratio of 90/10 wt%. Prepared. 28 using a 65mmφ extruder
Melt extruded from a T-die at a resin temperature of 0 ° C, and then rapidly cooled by closely adhering to a cast roll whose temperature was adjusted to 25 ° C.
An unstretched sheet of μm was obtained. The shear rate at the die at this time was 360 sec-1. Next, the unstretched sheet thus obtained was stretched 3.7 times at 100 ° C. by a roll type longitudinal stretching machine and 4.5 times at 105 ° C. by a tenter type transverse stretching machine, and then relaxed by 5% in the transverse direction. Then, heat treatment was performed at 240 ° C., corona discharge treatment was performed, and then the temperature was cooled to room temperature to obtain a biaxially oriented film having a thickness of 12 μm. The obtained biaxially stretched film subjected to corona discharge treatment was subjected to electron beam heating-type vacuum vapor deposition equipment, using silicon dioxide and aluminum oxide as vapor deposition materials to have a film thickness of 200Å and an aluminum oxide content of 4
A vapor deposition layer of 0% by weight was laminated. The tear straightness of the obtained laminated biaxially oriented polyester film was measured, and the results are shown in Tables 1 and 2.

(Example 1-2), (Comparative Example 1-1), (Comparative Example 1-2) The crystalline polyester (A) and the block copolymerized polyester (B) were used in Example 1-1, respectively. PE
A biaxially oriented polyester film was obtained in the same manner as in Example 1-1, except that the proportions of T and copolymerized PBT were changed as shown in Table 1.

Example 1-3 As block copolymerized polyester (B), terephthalic acid 1 as dicarboxylic acid component
00 mol%, butanediol 93.
10 wt% of copolymerized PBT (reduced viscosity 1.50 dl / g) consisting of 3 mol% and polytetramethylene glycol 6.7 mol%
A biaxially oriented polyester film was obtained in the same manner as in Example 1-1, except that the mixture was used in the proportion of%.

Comparative Example 1-3 As block copolymerized polyester (B), terephthalic acid 1 as dicarboxylic acid component
00 mol%, butanediol 85.
7 mol%, polytetramethylene glycol 14.3 mol%
5 wt% of copolymerized PBT (reduced viscosity 1.90 dl / g)
A biaxially oriented polyester film was obtained in the same manner as in Example 1-1, except that the mixture was used in the proportion of%.

(Comparative Example 1-4) After obtaining an unstretched sheet in the same manner as in Example 1-1, the obtained unstretched sheet was stretched 4.5 times at 100 ° C by a tenter type transverse stretching machine. It was then stretched 3.7 times at 90 ° C. by a roll-type longitudinal stretching machine. Thereafter, a relaxation treatment of 5% was performed in the lateral direction, a heat treatment was performed at 240 ° C., and the mixture was cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm.

(Comparative Example 1-5) The shear rate at the die was 1
A biaxially oriented polyester film was obtained in the same manner as in Example 1-1 except that the setting was 00 sec-1.

Comparative Example 1-6 A biaxially oriented polyester film was obtained in the same manner as in Example 1-1, except that simultaneous biaxial stretching was carried out as the stretching method.

(Example 1-4) Polyethylene terephthalate having an intrinsic viscosity of 0.75 dl / g obtained by melt polymerization to an intrinsic viscosity of 0.63 dl / g and then solid phase polymerization in an inert gas stream was crystallized. A biaxially oriented polyester film was obtained by the same method as in Example (1) -1 except that the polyester film (A) was used.

(Example 1-5) Example 1 except that polyethylene terephthalate having an intrinsic viscosity of 0.75 dl / g obtained by melt polymerization was used as the crystalline polyester (A).
A biaxially oriented polyester film was obtained in the same manner as in -1.

Comparative Example 1-7 A laminated biaxially oriented polyester film having a metal vapor deposition layer made of 100% aluminum on the biaxially stretched film made of the raw material described in Example 1-1 was obtained.

Example 2-1 As a crystalline polyester (A), SR553 manufactured by Toyobo Co., Ltd.
75 dl / g) as a block copolymerized polyester (B) and terephthalic acid 1 as a dicarboxylic acid component.
00 mol%, butanediol 96.
7 mol%, polytetramethylene glycol (molecular weight 10
00) 3.3 mol% polyester (reduced viscosity 1.33 dl / g) was mixed at a ratio of 88/15 wt% to prepare a mixture. 280 using a 65mmφ extruder
Melt extruded from a T-die at a resin temperature of ℃, and rapidly cooled by closely adhering to a cast roll whose temperature was adjusted to 25 ℃, and a thickness of about 200μ
An unstretched sheet of m was obtained. The shear rate at the die at this time was 360 sec-1. Then, the obtained unstretched sheet was stretched 3.7 times at 100 ° C. by a roll type longitudinal stretching machine and 4.5 times at 105 ° C. by a tenter type transverse stretching machine,
After heat treatment at 240 ° C., corona discharge treatment, and cooling to room temperature, a biaxially oriented polyester film having a thickness of 12 μm was obtained. The obtained biaxially stretched film that has been subjected to corona discharge treatment was subjected to electron beam heating-type vacuum vapor deposition apparatus using silicon dioxide and aluminum oxide as vapor deposition materials to obtain a film thickness of 20.
The isotropic evaluation and tear straightness of the laminated biaxially oriented polyester film obtained by laminating a vapor deposition layer having 0Å and an aluminum oxide content of 40% by weight were measured, and the results are shown in Tables 3 and 4.

(Example 2-2) The unstretched sheet obtained in the same manner as in Example 2-1 was heated to 110 times at 110 ° C in a roll-type longitudinal stretching machine and to 115 ° C in a tenter-type transverse stretching machine. 4.5
After stretching twice, it was heat-treated at 245 ° C. and cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm.

(Example 2-3) An unstretched sheet obtained in the same manner as in Example 2-1 was heated at 105 ° C with a tenter type transverse stretching machine.
At a temperature of 240 ° C. and then cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm. Obtained.

(Comparative Example 2-1) An unstretched sheet obtained in the same manner as in Example 2-1 was heated to 3.7 times at 90 ° C in a roll-type longitudinal stretching machine and to 95 ° C in a tenter-type transverse stretching machine. After stretching 4.5 times, it was heat-treated at 230 ° C. and cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm.

(Example 2-4) An unstretched sheet obtained in the same manner as in Example 2-1 was subjected to a simultaneous biaxial stretching method at 100 ° C.
Was stretched 4.1 times in the machine direction and 4.1 times in the width direction, heat-treated at 240 ° C. and cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm.

(Example 2-5) Example 2 except that the compounding amount of the block copolymerized polyester (B) was set to 19 wt%.
A biaxially oriented polyester film was obtained in the same manner as in -1.

(Example 2-6) Example 2 except that the blending amount of the block copolymerized polyester (B) was set to 19% by weight.
A biaxially oriented polyester film was obtained in the same manner as in -2.

Example 2-7 As block copolymerized polyester (B), 100 mol% of terephthalic acid as a dicarboxylic acid component and butanediol 9 as a diol component
3.3 mol%, polytetramethylene glycol 6.7 mol
% Polyester (reduced viscosity 1.50 dl / g) 8 wt
A biaxially oriented polyester film was obtained in the same manner as in Example 2-1 except that the mixture in the proportion of% was used.

Comparative Example 2-2 As block copolymerized polyester (B), 100 mol% of terephthalic acid as a dicarboxylic acid component and butanediol 8 as a diol component
5.7 mol%, polytetramethylene glycol 14.3 m
Example 2 except that a polyester composed of ol% (reduced viscosity 1.90 dl / g) was mixed at a ratio of 5 wt%
A biaxially oriented polyester film was obtained in the same manner as in 1.

(Comparative Example 2-3) A biaxially oriented polyester film was obtained in the same manner as in Example 2-1 except that polyethylene terephthalate having an intrinsic viscosity of 0.62 was used as the crystalline polyester (A).

(Comparative Example 2-4) A laminated biaxially oriented polyester film having a metal vapor deposition layer made of 100% aluminum on the biaxially oriented polyester film made of the raw material described in Example 2-1 was obtained.

Example 3-1 82 wt% of RE553 (intrinsic viscosity 0.62 dl / g) manufactured by Toyobo Co., Ltd. was used as the polyethylene terephthalate (a), and Novadul NV5 manufactured by Mitsubishi Plastics Co., Ltd. was used as the polybutylene terephthalate (b).
020 9 wt%, block copolymerized polyester (B), dicarboxylic acid component 100 mol terephthalic acid
%, Butanediol 93.3 mol as a diol component
%, And 6.7 mol% of polytetramethylene glycol having a molecular weight of 1000 (copolymerized PBT (reduced viscosity 1.50 d
l / g) was mixed in a solid chip state at a ratio of 9 wt% to prepare. This chip mixture is 200 mm with T-die
It was put into a φ extruder, melt-extruded at a resin temperature of 280 ° C., and closely adhered to a cast roll whose temperature was adjusted to 25 ° C. to be rapidly cooled to obtain an unstretched sheet having a thickness of about 200 μm. The shear rate at the die at this time was 360 sec-1. Then, the obtained unstretched sheet is subjected to 100 by a roll-type longitudinal stretching machine.
After stretching 3.7 times at ℃, 4.5 times at 105 ℃ with a tenter type transverse stretching machine, relaxation treatment of 5% in the transverse direction,
After heat treatment at 240 ° C., corona discharge treatment, and cooling to room temperature, a biaxially oriented polyester film having a thickness of 12 μm was obtained. The obtained biaxially stretched film that has been subjected to corona discharge treatment was subjected to electron beam heating-type vacuum vapor deposition apparatus using silicon dioxide and aluminum oxide as vapor deposition materials to obtain a film thickness of 20.
A vapor deposition layer having a thickness of 0Å and an aluminum oxide content of 40% by weight was laminated. The transesterification rate and tear straightness of the obtained laminated biaxially oriented polyester film were measured, and the results are shown in Tables 5 and 6.

Example 3-2 82% by weight of RE553 (intrinsic viscosity 0.62 dl / g) manufactured by Toyobo Co., Ltd. was used as the polyethylene terephthalate (a), and Novadur NV5 manufactured by Mitsubishi Plastics Co., Ltd. was used as the polybutylene terephthalate (b).
6% by weight of 020 as a block copolymerized polyester (B) and 100 mol of terephthalic acid as a dicarboxylic acid component
%, Butanediol 93.3 mol as a diol component
%, And 6.7 mol% of polytetramethylene glycol having a molecular weight of 1000 (copolymerized PBT (reduced viscosity 1.50 d
l / g) was mixed in a solid chip state at a ratio of 12 wt% to prepare a biaxially oriented polyester film in the same manner as in Example (3) -1. The transesterification rate and tear straightness of the obtained biaxially oriented polyester film were measured, and the results are shown in Tables 5 and 6.

Example 3-3 82% by weight of RE553 (intrinsic viscosity 0.62 dl / g) manufactured by Toyobo Co., Ltd. was used as the polyethylene terephthalate (a), and Novadur NV5 manufactured by Mitsubishi Plastics Co., Ltd. was used as the polybutylene terephthalate (b).
13.5 wt% of 020, block copolymerized polyester (B), terephthalic acid 1 as dicarboxylic acid component
00 mol%, butanediol 85.
Example 3-Preparation was made by mixing copolymerized PBT (reduced viscosity 1.90 dl / g) consisting of 7 mol% and polytetramethylene glycol 14.3 mol% having a molecular weight of 1000 in a solid chip state at a ratio of 4.5 wt%. A biaxially oriented polyester film was obtained in the same manner as in 1. The transesterification rate and tear straightness of the obtained biaxially oriented polyester film were measured, and the results are shown in Tables 5 and 6.

Example 3-4 82% by weight of RE553 (intrinsic viscosity 0.62 dl / g) manufactured by Toyobo Co., Ltd. was used as polyethylene terephthalate (a), and Novadur NV5 manufactured by Mitsubishi Plastics Co., Ltd. was used as polybutylene terephthalate (b).
020 1.0% by weight, block copolymerized polyester (B), terephthalic acid 1 as a dicarboxylic acid component
00 mol%, butanediol 96.
Copolymerized PBT consisting of 7 mol% and polytetramethylene glycol having a molecular weight of 1000 (3.3 mol%) (reduced viscosity 1.
33 dl / g) was mixed in the proportion of 17 wt% to prepare. This was melt extruded from a T-die at a resin temperature of 270 ° C. using a 90 mmφ extruder, and was closely adhered to a cast roll whose temperature was adjusted to 25 ° C. and rapidly cooled to obtain an unstretched sheet having a thickness of about 200 μm. The shear rate at the die at this time is 36
It was 0 sec-1. Next, the unstretched sheet thus obtained was stretched 3.7 times at 100 ° C. by a roll type longitudinal stretching machine and 4.5 times at 105 ° C. by a tenter type transverse stretching machine, and then relaxed by 5% in the transverse direction. Then, heat treatment was performed at 240 ° C., and the temperature was cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm. The transesterification rate and tear straightness of the obtained biaxially oriented polyester film were measured, and the results are shown in Table 5.
And shown in Table 6.

(Example 3-5) As the polyethylene terephthalate (a), RE553 (intrinsic viscosity 0.62 dl / g) manufactured by Toyobo Co., Ltd. was used, and as the block copolymerized polyester (B), terephthalic acid 1 was used as the dicarboxylic acid component.
00 mol%, butanediol 96.
Copolymerized PBT consisting of 7 mol% and polytetramethylene glycol having a molecular weight of 1000 (3.3 mol%) (reduced viscosity 1.
33 dl / g) was mixed at a ratio of 82/18 wt% to prepare a mixture. This was melt extruded from a T-die at a resin temperature of 270 ° C. using a 90 mmφ extruder, and was closely adhered to a cast roll whose temperature was adjusted to 25 ° C. and rapidly cooled to obtain an unstretched sheet having a thickness of about 200 μm. The shear rate at the die at this time was 360 sec-1. Next, the unstretched sheet thus obtained was stretched 3.7 times at 100 ° C. by a roll type longitudinal stretching machine and 4.5 times at 105 ° C. by a tenter type transverse stretching machine, and then relaxed by 5% in the transverse direction. Then, heat treatment was performed at 240 ° C., and the temperature was cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm. The transesterification rate and tear straightness of the obtained biaxially oriented polyester film were measured, and the results are shown in Tables 5 and 6.

(Comparative Example 3-1) As polyethylene terephthalate (a), RE553 (intrinsic viscosity 0.62 dl / g) manufactured by Toyobo Co., Ltd. was used, and as block copolymerized polyester (B), terephthalic acid 1 was used as a dicarboxylic acid component.
00 mol%, butanediol 96.
Copolymerized PBT consisting of 7 mol% and polytetramethylene glycol having a molecular weight of 1000 (3.3 mol%) (reduced viscosity 1.
33 dl / g) was mixed at a ratio of 90/10 wt% to prepare a mixture. This is 280 ℃ using a 200mmφ extruder
Melt extruded from the T-die at the resin temperature of, and then rapidly cooled by closely adhering to the cast roll adjusted to 25 ℃, and the thickness is about 200μm.
To obtain an unstretched sheet. The shear rate at the die at this time was 360 sec-1. Next, the unstretched sheet thus obtained was stretched 3.7 times at 100 ° C. by a roll type longitudinal stretching machine and 4.5 times at 105 ° C. by a tenter type transverse stretching machine, and then relaxed by 5% in the transverse direction. Treatment, heat treatment at 240 ℃,
After cooling to room temperature, a biaxially oriented polyester film having a thickness of 12 μm was obtained. The transesterification rate and tear straightness of the obtained biaxially oriented polyester film were measured, and the results are shown in Tables 5 and 6.

(Comparative Example 3-2) 82% by weight of RE553 (intrinsic viscosity 0.62 dl / g) manufactured by Toyobo Co., Ltd. was used as the polyethylene terephthalate (a), and the block copolymerized polyester (B) was terephthalic acid as the dicarboxylic acid component. Copolymerized PBT (reduced viscosity 1.50 dl / g) consisting of 100 mol%, butanediol 93.3 mol% as a diol component, and polytetramethylene glycol 6.7 mol% having a molecular weight of 1000 was mixed in a solid chip state at a ratio of 18 wt%. The same thing as in Example (3) -1 was prepared and 2
An axially oriented polyester film was obtained. The transesterification rate and tear straightness of the obtained biaxially oriented polyester film were measured, and the results are shown in Table (3). (Comparative Example (3)-
3) A laminated biaxially oriented polyester film having a metal vapor deposition layer made of 100% aluminum on the biaxially oriented polyester film made of the raw material described in Example (3) -1 was obtained.

Example 4-1 82% by weight of RE553 (intrinsic viscosity 0.63 dl / g) manufactured by Toyobo Co., Ltd. was used as the polyethylene terephthalate (a), and terephthalic acid was used as the dicarboxylic acid component as the block copolymerized polyester (B). Ester was added to a mixture of copolymerized PBT (reduced viscosity 1.33 dl / g) consisting of 100 mol%, butanediol 96.7 mol% as a diol component, and polytetramethylene glycol 3.3 mol% having a molecular weight of 1000 at a ratio of 18 wt%. Polyester composition 1 containing bis (acetadeca) pentaerythritol diphosphite as an exchange inhibitor (Adeka Stab PEP-8, manufactured by Asahi Denka Co., Ltd.)
What was added so that it might be a ratio of 0.4 weight part with respect to 00 weight part was prepared. 200mmφ with T-die
It is put into an extruder, melt-extruded at a resin temperature of 280 ° C., closely adhered to a cast roll whose temperature is adjusted to 25 ° C., and rapidly cooled.
An unstretched sheet having a thickness of about 200 μm was obtained. The shear rate at the die at this time was 360 sec-1. Next, the unstretched sheet thus obtained was stretched 3.7 times at 100 ° C. by a roll type longitudinal stretching machine and 4.5 times at 105 ° C. by a tenter type transverse stretching machine, and then relaxed by 5% in the transverse direction. Processed, 240 ℃
Was subjected to a heat treatment, corona discharge treatment and then cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm. On the obtained biaxially stretched film having been subjected to corona discharge treatment, a vapor deposition layer having a film thickness of 200Å and an aluminum oxide content of 40% by weight was laminated using silicon dioxide and aluminum oxide as vapor deposition materials by using an electron beam heating type vacuum vapor deposition apparatus. .
The transesterification rate and tear straightness of the obtained laminated biaxially oriented polyester film were measured, and the results are shown in Tables 7 and 8.

Example 4-2 As an alternative to the transesterification inhibitor in Example 4-1, bis (2,6-t-butyl-4-methylphenyl) pentaerythritol diphosphite (manufactured by Asahi Denka Co., Ltd.) , Product name, ADEKA STAB PEP-
36) based on 100 parts by weight of the polyester composition.
Example 4 except that it was added in an amount of 7 parts by weight.
The same experiment as in 1 was performed.

(Example 4-3) Bis (2,4-dicumylphenyl) pentaerythritol diphosphite was used as an alternative to the transesterification inhibitor in Example 4-1 (Adeka Stub, trade name, manufactured by Asahi Denka Co., Ltd.). An experiment similar to that of Example 4-1 was performed, except that PEP-45) was added in an amount of 0.7 parts by weight relative to 100 parts by weight of the polyester composition.

Comparative Example (4) -1 The same experiment as in Example 4-1 was carried out except that the transesterification inhibitor was not used in Example 4-1.

Example 4-4 82% by weight of RE553 (intrinsic viscosity 0.63 dl / g) manufactured by Toyobo Co., Ltd. was used as the polyethylene terephthalate (a), and terephthalic acid was used as the dicarboxylic acid component as the block copolymerized polyester (B). Copolymerized PBT (reduced viscosity 1.33 dl / g) consisting of 100 mol%, butanediol 96.7 mol% as a diol component, and polytetramethylene glycol 3.3 mol% having a molecular weight of 1000 was 13.5 wt%, and further as a dicarboxylic acid component. Terephthalic acid 100mol%, butanediol 85.7mol% as diol component, molecular weight 100
Copolymerized PBT consisting of 14.3 mol% of polytetramethylene glycol of 0 (reduced viscosity 0.841 dl / g) is 4.5
To the mixture of wt%, as a transesterification inhibitor, bis (acetadeca) pentaerythritol diphosphite ... (Asahi Denka Co., Ltd., trade name, ADEKA STAB PEP-8)
Was added at a ratio of 0.4 parts by weight to 100 parts by weight of the polyester composition. This was put into a 200 mmφ extruder equipped with a T-die, melt-extruded at a resin temperature of 280 ° C., and closely adhered to a cast roll whose temperature was adjusted to 25 ° C. to be rapidly cooled to obtain an unstretched sheet having a thickness of about 200 μm. The shear rate at the die at this time is 360 sec-
Was 1. Next, the unstretched sheet thus obtained was stretched 3.7 times at 100 ° C. by a roll type longitudinal stretching machine and 4.5 times at 105 ° C. by a tenter type transverse stretching machine, and then relaxed by 5% in the transverse direction. Then, heat treatment was performed at 240 ° C., and the temperature was cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm. The transesterification rate and tear straightness of the obtained biaxially oriented polyester film were measured, and the results are shown in Tables 7 and 8.

(Example 4-5) As a substitute for the transesterification inhibitor in Example 4-4, bis (2,6-t-butyl-4-methylphenyl) pentaerythritol diphosphite was used as the polyester composition 100. An experiment similar to that in Example 4-4 was performed, except that the addition was carried out at a ratio of 0.7 parts by weight with respect to parts by weight.

Example 4-6 Bis (2,4-dicumylphenyl) pentaerythritol diphosphite was used in place of the transesterification inhibitor in Example (4) -4.
(Asahi Denka, trade name, ADEKA STAB PEP-45) was added in an amount of 0.7 parts by weight based on 100 parts by weight of the polyester composition, and the same experiment as in Example 4-4 was conducted. .

Example 4-7 The same experiment as in Example 4-1 was carried out except that the amount of the transesterification inhibitor added in Example 4-1 was 0.2 part by weight.

Example 4-8 The same experiment as in Example 4-2 was conducted except that the amount of the transesterification inhibitor added in Example 4-2 was 0.3 part by weight.

Example 4-9 The same experiment as in Example 4-3 was conducted except that the amount of the transesterification inhibitor added in Example 4-3 was 0.3 part by weight.

Comparative Example 4-2 The same experiment as in Example 4-4 was carried out except that the transesterification inhibitor was not used in Example 4-4.

(Comparative Example 4-3) A laminated biaxial polyester film having a metal vapor deposition layer made of 100% aluminum on the biaxially oriented polyester film made of the raw material described in Example 4-1 was obtained.

Example 5-1 82 wt% of RE553 (intrinsic viscosity 0.63 dl / g) manufactured by Toyobo Co., Ltd. was used as the polyethylene terephthalate (a), and Novadur NV5 manufactured by Mitsubishi Plastics Co., Ltd. was used as the polybutylene terephthalate (b).
6% by weight of 020 as a block copolymerized polyester (B) and 100 mol of terephthalic acid as a dicarboxylic acid component
%, Butanediol 93.3 mol as a diol component
%, And 6.7 mol% of polytetramethylene glycol having a molecular weight of 1000 (copolymerized PBT (reduced viscosity 1.50 d
l / g) was mixed in a ratio of 12 wt% in a solid chip state to prepare. To this chip mixture, bis (acetadeca) pentaerythritol diphosphite was added as a transesterification inhibitor in an amount of 0.4 parts by weight with respect to 100 parts by weight of the polyester composition.
The mixture was put into a 200 mmφ extruder equipped with a die, melt-extruded at a resin temperature of 280 ° C., and closely adhered to a cast roll whose temperature was adjusted to 25 ° C. to rapidly cool it to obtain an unstretched sheet having a thickness of about 200 μm. The shear rate at the die at this time is 360 sec-1
Met. Next, the unstretched sheet thus obtained was stretched 3.7 times at 100 ° C. by a roll type longitudinal stretching machine and 4.5 times at 105 ° C. by a tenter type transverse stretching machine, and then relaxed by 5% in the transverse direction. Then, heat treatment was performed at 240 ° C., corona discharge treatment was performed, and then the mixture was cooled to room temperature to obtain a biaxially oriented polyester film having a thickness of 12 μm. The obtained biaxially stretched film having been subjected to corona discharge treatment was subjected to an electron beam heating-type vacuum vapor deposition apparatus, using silicon dioxide and aluminum oxide as vapor deposition materials to have a film thickness of 200Å and an aluminum oxide content of 40% by weight.
The vapor deposition layer of was laminated. The transesterification rate and tear straightness of the obtained biaxially oriented polyester film were measured,
The results are shown in Table 9 and Table 10.

(Example 5-2) Polyester composition 100 was prepared by using bis (2,6-t-butyl-4-methylphenyl) pentaerythritol diphosphite instead of the transesterification inhibitor in Example 5-1. The same experiment as in Example 5-1 was carried out except that the addition was carried out at a ratio of 0.7 parts by weight with respect to parts by weight.

Example 5-3 Bis (2,4-dicumylphenyl) pentaerythritol diphosphite was used as a substitute for the transesterification inhibitor in Example 5-1 with respect to 100 parts by weight of the polyester composition. The same experiment as in Example 5-1 was carried out, except that the amount was 0.7 parts by weight.

Example 5-4 The same experiment as in Example 5-1 was conducted except that the amount of the transesterification inhibitor added in Example 5-1 was 0.2 part by weight.

Example 5-5 The same experiment as in Example 5-2 was carried out except that the addition amount of the transesterification inhibitor in Example 5-2 was 0.3 part by weight.

Example 5-6 The same experiment as in Example 5-3 was conducted except that the addition amount of the transesterification inhibitor in Example 5-2 was 0.3 part by weight.

Comparative Example 5-1 Example (5) -1 except that the transesterification inhibitor was not used in Example (5) -1.
The same experiment was performed.

(Comparative Example 5-2) A laminated biaxially oriented polyester film having a metal vapor deposition layer made of 100% aluminum on the biaxially oriented polyester film made of the raw material described in Example 5-1 was obtained.

[0090]

[Table 1]

[0091]

[Table 2]

[0092]

[Table 3]

[0093]

[Table 4]

[0094]

[Table 5]

[0095]

[Table 6]

[0096]

[Table 7]

[0097]

[Table 8]

[0098]

[Table 9]

[0099]

[Table 10]

[0100]

According to the present invention, the biaxially oriented polyester film has the characteristics of durability, moisture resistance, mechanical properties, heat resistance, and oil resistance, and at the same time, has a linear tearing property in the MD direction of the film, Provided is a biaxially stretched polyester laminated film having improved bag drop strength and excellent gas barrier properties.
Further, the biaxially oriented polyester film as the base material can be efficiently and inexpensively provided by using a large-scale production by a large-scale production machine or a production method utilizing recovered raw materials.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a measuring method of tear straightness.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C23C 14/20 C23C 14/20 Z // B29K 67:00 B29K 67:00 B29L 7:00 B29L 7:00 9:00 9:00 F-term (reference) 4F006 AA35 AB72 AB74 BA05 CA07 DA01 EA03 4F100 AA02B AA02C AA19B AA19C AA20B AA20C AK41A AK41J AK42A AL02A AL05A BA02 BA03 BA06 BA10B BA10C EH66B EH66C EJ38A GB15 JA04A JA07A JA11A JA20A JA20C JD03 JD04 JK10A JN30 YY00 YY00A YY00B YY00C 4F210 AA24F AG01 AG03 QC05 QC06 QG01 QG18 QW07 QW50 4J002 CF042 CF052 CF061 CF062 CF071 CF072 CF081 CF082 CF092 CF102 CF132 CF192 GB01 GC00 GG00 GG02 4K029 AA11 AA25 BA03 BA35 BA44 CA46 CA01 CA03 CA03 CA03 CA03 CA03 CA03 CA03 CA03

Claims (13)

[Claims] 1. A vapor-deposited layer of an oxide is laminated on at least one surface of a biaxially oriented polyester film having an impact strength of 450 J / cm or more and excellent in tear straightness in the machine direction, A laminated biaxially oriented polyester film satisfying the conditions (1) to (3). (L) Haze value ≦ 8% (2) Water vapor transmission rate ≦ 20 g / m ² · 24 hr (40 ° C./90
% RH) (3) Oxygen permeability ≦ 100 cc / m ² · 24 hr · at
m (25 ° C / 50% RH) 2. A laminated biaxially oriented polyester film, wherein the biaxially oriented polyester film according to claim 1 has an isotropic evaluation value of 0.70 or less. 3. The biaxially oriented polyester film according to claim 1, wherein the polyester constituting the biaxially oriented polyester film is composed of two or more kinds of polyesters, and the transesterification rate <B> of these is less than 0.150. And a laminated biaxially oriented polyester film. 4. The polyester raw material constituting the biaxially oriented polyester film according to claim 3, wherein 80 mol% or more of the acid component is terephthalic acid and 97 m of the glycol component.
Polyester (A) Group 9 comprising at least one crystalline polyester resin comprising ol% or more alone glycol
0 to 70% by weight, a crystal segment having a melting point of 170 ° C or higher and a melting point or softening point of 100 ° C or lower, and a molecular weight of 400 to 80
A laminated biaxially oriented polyester film comprising a mixture of 10 to 30 wt% of block copolymerized polyester (B) consisting of a soft polymer of No. 00. 5. As the polyester raw material constituting the biaxially oriented polyester film according to claim 3, two types of resins, polyethylene terephthalate and polybutylene terephthalate, are used as the crystalline polyester resin (A) and a block copolymerized polyester (B). ) Is used, and a laminated biaxially oriented polyester film is used. 6. A laminated biaxially oriented polyester film, wherein the polyester constituting the biaxially oriented polyester film according to any one of claims 3, 4, and 5 contains a transesterification inhibitor. 7. A bilaminate axially oriented polyester film, wherein the transesterification inhibitor according to claim 6 is an organophosphorus compound having at least one P—O bond in the molecule. 8. The biaxially oriented polyester film according to claim 1, wherein the polyester constituting the biaxially oriented polyester film is composed of two or more kinds of polyesters, and the transesterification rate <B> of these is less than 0.100. And a laminated biaxially oriented polyester film. 9. The biaxially oriented polyester film according to claim 1, wherein the polyester constituting the biaxially oriented polyester film is composed of two or more kinds of polyesters, and the transesterification rate <B> value of these is less than 0.070. And a laminated biaxially oriented polyester film. 10. A laminated biaxially oriented polyester film, wherein the oxide vapor deposition layer according to any one of claims 1 to 9 has a thickness of 10 to 5000 liters. 11. A laminated biaxially oriented polyester film, wherein the oxide according to any one of claims 1 to 10 is silicon oxide, aluminum oxide, a mixture or compound thereof. 12. The polyester raw material constituting the biaxially oriented polyester film according to claim 4, wherein 80 mol% or more of the acid component is terephthalic acid and 9 of the glycol component.
Polyester (A) prepared by using at least one crystalline polyester resin containing 7 mol% or more of a single glycol.
Group 90-70 wt% and crystalline segment having a melting point of 170 ° C or higher and melting point or softening point of 100 ° C or lower, molecular weight of 400-
A method for producing a laminated biaxially oriented polyester film, which comprises extruding and biaxially stretching a mixture of 10 to 30 wt% of block copolymerized polyester (B) composed of 8000 soft polymers simultaneously in a chip state. 13. As the polyester raw material constituting the biaxially oriented polyester film according to claim 5, two types of resins, polyethylene terephthalate and polybutylene terephthalate, are used as the crystalline polyester resin (A).
A method for producing a laminated biaxially oriented polyester film, which comprises extruding a mixture of block copolymerized polyester resin (B) simultaneously in a chip state and biaxially stretching it.