JP2005161843A - Thermoplastic resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin film excellent in gas barrier property and mechanical strength and suitable for packaging. <P>SOLUTION: This thermoplastic resin film is produced by alternately laminating the layer of a thermoplastic resin (B) containing a mesogenic group of 0.1 mol% or more and that of another thermoplastic resin (A) containing the mesogenic group of 35 mol% or less in five layers or more in total without interposing an adhesive layer. The film is characterized in that the mesogenic group content in the resin (B) is higher than that of the resin (A). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thermoplastic resin film. More specifically, the present invention relates to a thermoplastic resin film excellent in gas barrier properties and mechanical strength and suitable for packaging applications.

  Packaging materials such as foods, pharmaceuticals, and cosmetics are required to have high barrier properties such as oxygen and water vapor in order to suppress deterioration of the packaged contents. Conventionally, since the polyvinylidene chloride which shows the high gas barrier property used has a chlorine element, the alternative is examined. For example, a barrier material made of an ethylene-vinyl alcohol copolymer has been proposed. However, since ethylene vinyl alcohol copolymer has a hydroxyl group, it is hydrophilic, and barrier properties are greatly reduced under high humidity. Moreover, since mechanical strength is weak, there exists a problem that it is difficult to use by itself. In addition, high oxygen barrier materials using composite nylon films have been proposed. (For example, refer patent document 2) However, since hydrophilicity is similarly strong, there exists a subject that it is inferior to water vapor | steam barrier property.

In addition, thermoplastic resins containing mesogenic groups are known to exhibit high gas barrier properties, high heat resistance, and low hygroscopicity because they exhibit liquid crystallinity and are easy to be highly oriented. It has been put to practical use as a fiber. However, if the resin exhibiting liquid crystallinity is subjected to normal extrusion, strong orientation occurs in the flow direction, resulting in a strong anisotropic film, which makes it difficult to stretch in the width direction. As a method for eliminating such anisotropy, an inflation method has been proposed. (For example, see Patent Document 3 and Patent Document 4) However, although the liquid crystalline resin film obtained by these methods has solved the problem of physical property balance in the flow direction and the width direction, the problem of surface roughness inherent to the liquid crystalline resin, In addition, problems such as designability and transparency necessary for packaging applications have not been solved.
JP-A-5-271498 (page 1, line 23) JP 2001-310425 A (page 1, line 26) Japanese Examined Patent Publication No. 6-39533 (page 1, line 33) JP-A-4-286626 (page 1, line 33)

  In view of the above-mentioned problems of the prior art, the object of the present invention is to achieve moldability by laminating five or more mesogenic group-containing thermoplastic resins exhibiting high gas barrier properties even under high humidity without using an adhesive. It is an object of the present invention to provide a high gas barrier thermoplastic resin that is excellent in design and transparency.

  In order to solve this problem, the thermoplastic resin film of the present invention has the following configuration. That is, the thermoplastic resin (B) layer containing 0.1 mol% or more of mesogenic groups and the thermoplastic resin (A) layer having a mesogenic group content of 35 mol% or less alternately have five layers without interposing an adhesive layer. The thermoplastic resin film is characterized by being laminated as described above and having a mesogenic group content in the thermoplastic resin (B) higher than a mesogenic group content in the thermoplastic resin (A).

  The thermoplastic resin film in the present invention is a thermoplastic resin film that is excellent in gas barrier properties and high mechanical strength expressed by high elongation and suitable for packaging applications.

  The thermoplastic resin film of the present invention has a thermoplastic resin (B) layer containing 0.1 mol% or more of mesogenic groups and a mesogenic group content of 35 mol% in terms of high gas barrier properties and high mechanical strength. Five or more layers of the following thermoplastic resin (A) layers are alternately laminated without an adhesive layer, and the mesogenic group content in the thermoplastic resin (B) is the mesogenic group in the thermoplastic resin (A). It is necessary to be characterized by more than the content. In the present invention, the content of the mesogenic group in the thermoplastic resin (A) is 35 mol% or less and is less than the content of the mesogenic group in the thermoplastic resin (B). The following is preferable, and the most preferable form is one containing no mesogenic group. The upper limit of the mesogenic group content in the thermoplastic resin (B) is not particularly limited, but is preferably 85 mol% or less from the viewpoint of moldability.

  Here, the mesogenic group refers to a rigid atomic group that is the center for forming the liquid crystal layer, and is a group that has a rod-like or planar structure and exhibits high alignment. By containing a mesogenic group in the thermoplastic resin, the mesogenic group is highly oriented, and thus exhibits high gas barrier properties and high mechanical strength. The mesogenic group in the present invention is not particularly limited, but is preferably a compound selected from hydroxy aromatic carboxylic acids, aromatic dicarboxylic acids, and aromatic dihydroxy compounds in terms of moldability, barrier properties, and mechanical properties. More preferred are compounds selected from structural formulas (1) to (10). Further, the aromatic ring may have a substituent as long as the rigidity is not lost.

  (Structural formula 1)

  (Structural formula 2)

  (Structural formula 3)

   (Structural formula 4)

   (Structural formula 5)

  (Structural formula 6)

  (Structural formula 7)

  (Structural formula 8)

  (Structural formula 9)

  (Structural formula 10)

  The polymerization method of the mesogenic group-containing thermoplastic resin in the present invention is not particularly limited, and can be polymerized according to a normal polyester polycondensation method. For example, hydroxy aromatic carboxylic acid, aromatic dihydroxy compound, aromatic dicarboxylic acid And the like, and a method of producing a phenolic hydroxyl group by reacting with acetic anhydride, followed by deacetic acid polycondensation reaction. The deacetic acid polycondensation referred to here is by repeating the deacetic acid reaction between the acylated hydroxyl group of the aromatic dihydroxycarboxylic acid and aromatic dihydroxy compound and the carboxylic acid group of the aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid, It means a polycondensation reaction in which acetic acid is distilled out of the system and polymerization proceeds. In addition, the mesogen group-containing thermoplastic resin of the present invention may be added with additives such as a copolymerization monomer, a catalyst and / or an anti-coloring agent, an antioxidant, a thermal stabilizer, and a flame retardant.

  The thermoplastic resin not containing a mesogenic group in the present invention is not particularly limited, for example, a polyolefin resin such as polyethylene, polypropylene, or polymethylpentene, a polyamide resin such as nylon 6, nylon 66, or nylon 12, a polyethylene terephthalate, or a polybutylene. Examples thereof include polyester resins such as terephthalate and polyethylene-2,6-naphthalate, polycarbonate resins, polyacetal resins, polyphenylene sulfide resins, and acrylic resins.

  These resins may be homo-resins, copolymerized or blended. Also, various additives in the resin, such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, thickeners, thickeners, compatibilizers, thermal stabilizers, lubricants, infrared absorbers An ultraviolet absorber or the like may be added.

In the present invention, the difference in melt viscosity between the thermoplastic resin (A) and the thermoplastic resin (B) under conditions of a temperature of 280 ° C. and a shear rate of 100 (s ⁻¹ ) is preferably 150 Pa · s or less. When the difference in melt viscosity is larger than 150 Pa · s, the film-forming property is inferior, the thermoplastic resin (B) is not easily formed into a uniform film, and high gas barrier properties may not be exhibited. More preferably, the difference in melt viscosity between the thermoplastic resin (A) and the thermoplastic resin (B) is 130 Pa · s or less, and most preferably 100 Pa · s or less. Since the melt viscosity of the thermoplastic resin containing a mesogenic group varies greatly depending on the shear rate, it is important that the difference in melt viscosity at the time of extrusion of the thermoplastic resin (A) and the thermoplastic resin (B) is small. For this reason, it is necessary to compare under the condition of 100 (s ⁻¹ ), which is the shear rate at the time of extrusion.

  The thermoplastic resin in the present invention is particularly preferably a polyester resin in terms of moldability and mechanical strength among the above-described resins. Here, the polyester resin is a polymer obtained by polycondensation of a diol component and a dicarboxylic acid component. Specific examples of the diol component include ethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexanedimethanol, neopentyl glycol, polyalkylene glycol, and bisphenol A ethylene oxide adduct. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid, cyclohexanedicarboxylic acid, and metal sulfoisophthalic acid, and these diester derivatives may also be used. Among these, examples of the metal sulfoisophthalic acid include sodium sulfoisophthalic acid, calcium sulfoisophthalic acid, and magnesium sulfoisophthalic acid.

  Combinations of these diol components and dicarboxylic acid components or ester derivatives thereof are arbitrary, and when polycondensed from three or more components, the resulting polyester becomes a copolyester. Among these polyesters, polyethylene terephthalate obtained by polycondensation from diethylene glycol and terephthalic acid or dimethyl terephthalate is more preferable from the viewpoint of economy and moldability.

  In producing the polyester in the present invention, a reaction catalyst, an anti-coloring agent and the like can be used. As the reaction catalyst, for example, an alkali metal compound, an alkaline earth metal compound, a zinc compound, a lead compound, a titanium compound, a germanium compound or the like can be used, and as a coloring inhibitor, a phosphorus compound or the like can be used.

  Usually, it is preferable to add an antimony compound, a germanium compound and / or a titanium compound as a polymerization catalyst at an arbitrary stage before the production of the polyester is completed.

  The antimony compound is not particularly limited, and for example, oxides such as antimony trioxide, antimony acetate, and the like can be used. Further, the titanium compound is not particularly limited, but titanium tetraalkoxide such as titanium tetraethoxide and titanium tetrabutoxide can be preferably used.

  Examples of germanium compounds include germanium dioxide, germanium hydroxide hydrate or germanium tetramethoxide, germanium alkoxide compounds such as germanium ethylene glycoxide, phosphoric acids such as germanium phenoxide compounds, germanium phosphate, and germanium phosphite. Germanium-containing compounds, germanium acetate, and the like can be used. Of these, germanium dioxide is preferably used.

  In the present invention, the mesogenic group is sheared and oriented more easily on the surface layer. Therefore, in order to increase the highly oriented interface, it is possible to alternately form a multilayer laminated film of 5 or more layers in order to reduce the thickness per layer. preferable. Moreover, reducing the thickness per layer is also preferable from the viewpoint of transparency.

  Also, a mesogenic group-containing thermoplastic resin, which usually has a strong anisotropy during extrusion, is difficult to form a uniform film, and is difficult to stretch, alternates with a 35 mol% or less thermoplastic resin in which the mesogenic group weakens liquid crystallinity. By laminating five or more layers, it becomes easy to form a uniform film as a whole and can be easily stretched.

  In the present invention, the method of laminating the thermoplastic resin (A) and the thermoplastic resin (B) into five or more layers is not particularly limited. For example, the thermoplastic resin fed from different flow paths using two or more extruders. A method of laminating a plurality of layers using a feed block, a static mixer, a multi-manifold die, or the like can be used. Here, examples of the static mixer include a pipe mixer and a square mixer, but the square mixer is preferable.

  The thermoplastic resin film of the present invention may be unstretched, uniaxially stretched, or biaxially stretched, but is preferably stretched biaxially in terms of mechanical strength and barrier properties.

  The biaxial stretching method is not particularly limited, but a sequential biaxial stretching method in which a uniaxial stretching is performed in the longitudinal direction due to a roll speed difference, and the uniaxial stretching is stretched in the width direction with a tenter, or a tenter. And a method of stretching biaxially at the same time. The stretching ratio is preferably 1.6 to 4.2 times in each direction, and more preferably 2.4 to 4.0 times. Further, the stretching speed is desirably 1000 to 200000% / min, and the stretching temperature can be any temperature as long as it is in the temperature range from the glass transition temperature of the thermoplastic resin (A) to the glass transition temperature + 100 ° C. However, the stretching temperature in the longitudinal direction is preferably 80 to 130 ° C., and the stretching temperature in the width direction is preferably 90 to 130 ° C.

  In addition, the biaxially stretched film is preferably subjected to a heat treatment in order to impart flatness and dimensional stability. The heat treatment can be performed by an arbitrary method such as in an oven or on a heated roll. The heat treatment temperature can be any temperature not lower than the stretching temperature and not higher than the melting point, but is preferably 160 to 240 ° C. from the viewpoint of moldability. The heat treatment time can be arbitrarily set within a range not deteriorating other characteristics, but it is usually preferable to carry out for 1 to 30 seconds. Further, the heat treatment may be performed by relaxing the film in the longitudinal direction and the width direction.

The porosity of the thermoplastic resin film of the present invention is preferably less than 3%. Here, the porosity means the specific gravity of the biaxially stretched film formed from the thermoplastic resin A alone and the chip of the thermoplastic resin B, and the theoretical specific gravity required from the measured specific gravity and the actually measured thermoplastic resin film. It is obtained from the following formula from the specific gravity of.
Porosity = {(theoretical specific gravity−measured specific gravity) / (theoretical specific gravity)} × 100
When the porosity is 3% or more, there are cases where the interfacial adhesiveness between the (A) layer and the (B) layer is inferior, or there are cracks in the film, particularly the (B) layer. This is not preferable because high gas barrier properties and mechanical strength are lowered. More preferably, the porosity is less than 2%. The method for setting the porosity of the polyester film of the present invention to less than 3% is not particularly limited, and examples thereof include a method of eliminating voids generated by a heating roll or a heating press after stretching. At this time, it is preferable that the temperature of the heating roll or the heating press is equal to or higher than the melting point of the thermoplastic resin (B) because voids can disappear.

  The thickness of the thermoplastic resin film of the present invention is preferably 6 to 50 μm from the viewpoint of film formation stability. Furthermore, when using as a packaging material, it is preferable that it is 8-20 micrometers.

  The lamination ratio of the thermoplastic resin (A) of the present invention to the mesogenic group-containing thermoplastic resin (B) is (layer A thickness) / (layer B thickness) = 0.2 in terms of laminateability and film formation stability. It is preferably ~ 20. From the viewpoint of high gas barrier properties and high mechanical strength, it is preferable that (A layer thickness) / (B layer thickness) = 0.5-10.

  Further, the thickness per layer is preferably 700 nm or less from the viewpoint of an increase in highly oriented interface and transparency. More preferably, it is 380 nm or less, which is the wavelength region of visible light or less.

  An evaluation method of physical property values used in the present invention will be described.

(Melting point of thermoplastic resin)
About 5 mg of a thermoplastic resin was heated from a temperature of 25 ° C. to 250 ° C. at 20 ° C./min by a differential scanning calorimeter (DSC7 manufactured by Perkin Elmer Co.), and rapidly cooled after being kept at 250 ° C. for 5 minutes. Thereafter, the temperature was again measured from 25 ° C. to 250 ° C. at a rate of temperature increase of 20 ° C./min, and the endothermic peak temperature was taken as the melting point.

(Liquid crystal starting temperature of mesogen-containing thermoplastic resin)
A state where heat was gradually applied to 5 mg of a mesogen group-containing thermoplastic resin chip using a Yanako trace melting point measuring apparatus MP-500D was observed, and a temperature at which the resin flowed was defined as a liquid crystal starting temperature.

(Melt viscosity)
Using Capillograph 1C (manufactured by Toyo Seiki Co., Ltd.), the value at a temperature of 280 ° C. was measured. The load was adjusted to determine the melt viscosity when the shear rate was 100 (s ⁻¹ ) and 1000 (s ⁻¹ ). The unit is indicated by Pa · s.

(Lamination ratio)
The cross section of the film was photographed with a transmission electron microscope (Hitachi, Ltd. TEM H7100), and the lamination ratio of the film was measured. The magnification was observed at 6000 times.

(Porosity)
Thermoplastic resin film (film formed in Examples 12-14), biaxially stretched PET film (film formed in Comparative Example 1), thermoplastic resin (B) chip (used in Examples 12-14) The specific gravity of the chips was measured by impregnating each in a density gradient tube (NaBr aqueous solution, 25 ° C.) for 20 hours. In the case of a film, the measurement was performed with a sample of 5 mm × 5 mm square, and in the case of a chip, a 2 mm × 5 mm × 5 mm straw type. From the determined specific gravity, the porosity of the thermoplastic resin film was determined by the following equation.
Porosity (%) = {specific gravity (theoretical value) −specific gravity (actual value)} / specific gravity (theoretical value) × 100
Specific gravity (theoretical value) = specific gravity of biaxially stretched PET film × laminate thickness fraction of PET layer (A) + thermoplastic resin (B) specific gravity of chip × laminate thickness fraction of thermoplastic resin (B) layer PET layer (A) Layer thickness ratio = (A / A + B)
Lamination thickness fraction of thermoplastic resin (B) layer = (B / A + B)
Specific gravity (actual value) = specific gravity of thermoplastic resin film.

(Oxygen permeability)
Measurement was performed by depositing an inorganic thin film on the thermoplastic resin film. The vapor deposition method of the inorganic thin film was as follows. The surface of the thermoplastic resin film is subjected to corona discharge treatment under a treatment condition of 40 W · min / m ^{2 in} an atmosphere of a mixed gas of nitrogen / carbon dioxide (nitrogen / carbon dioxide 85/15), and the wetting tension of the film is 45 mN / m or more and wound into a roll. The temperature of the film at that time was 30 ° C., and the film was slit for a short time after being left for 10 hours. Next, the film slit in a small width is set in a vacuum vapor deposition apparatus equipped with a film traveling apparatus, and after being made a high vacuum of 1.00 × 10 ⁻² Pa, it is traveled through a cooling metal drum at −20 ° C. It was. At this time, while the aluminum metal was evaporated by heating, it was agglomerated on the corona discharge treatment surface of the running film, and an aluminum vapor deposition thin film layer was formed and wound up. After vapor deposition, the inside of the vacuum vapor deposition apparatus was returned to normal pressure, the wound film was wound up, and aged at a temperature of 40 ° C. for 2 days to deposit an inorganic thin film. This inorganic thin film vapor-deposited thermoplastic resin film was measured using an oxygen permeability meter (OXTRAN-100) manufactured by Modern Control Co., Ltd. under the conditions of humidity 80% and temperature 23 ° C., and shown as a converted value per 12 μm thickness. It was. The thickness was converted by the following equation when the sample thickness was a (μm) and the oxygen permeability of the sample was b (cc / m ² · day).
Oxygen permeability (12 μm equivalent) = b × (a / 12)
(Water vapor transmission rate)
An inorganic thin film is vapor-deposited on the thermoplastic resin film in the same manner as the oxygen transmission rate, and using a water vapor transmission rate meter (PERMATRANW 3/31) manufactured by Modern Control, under the conditions of humidity 100% and temperature 37.8 ° C. The measured value was shown as a converted value per thickness of 12 μm. The thickness was converted by the same method as the oxygen transmission rate.

(Strong elongation)
Using a tensile tester (Tensilon AMF / RTA-100 manufactured by Orientec Co., Ltd.), set a sample film with a width of 10 mm so that the length between chucks is 50 mm (initial sample length), and conditions of 25 ° C. and 65% RH A tensile test was performed at a tensile speed of 300 mm / min. The maximum point elongation was obtained from the following equation.
Maximum point elongation (%) = {(sample length when stress applied to film is maximum−initial sample length) / initial sample length} × 100
The Young's modulus was obtained from the tangent line of the rising portion using a MP-200S data processing program based on the stress-strain curve recorded in the tensile test.

(Intrinsic viscosity of polyethylene terephthalate)
Polyethylene terephthalate was dissolved in o-chlorophenol and measured at 25 ° C. (ASTM D1601-86 (1991)).

(Example 1)
The manufacturing method of the thermoplastic resin (A) of a thermoplastic resin film is shown below. To a mixture of 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol, 0.08 parts by weight of magnesium acetate and 0.022 parts by weight of antimony trioxide are added to dimethyl terephthalate and the temperature is raised from 150 ° C. to 235 ° C. Then, methanol was distilled out of the system to carry out a transesterification reaction. Next, 0.019 part by weight of 85% phosphoric acid aqueous solution is added, and the temperature is gradually raised and reduced from 235 ° C., and finally heated to 290 ° C. and 0.5 mmHg and reduced to an intrinsic viscosity of 0.65. The polycondensation reaction was carried out until it was discharged into a strand, cooled, and cut to obtain a polyethylene terephthalate resin. Simultaneously with the addition of the phosphoric acid aqueous solution, an ethylene glycol slurry of agglomerated silica particles having an average secondary particle diameter of 1.2 μm was added so as to have a particle concentration of 2 parts by weight to obtain a particle master polyester resin.

As the thermoplastic resin (B) containing a mesogenic group, 46.5 mol% of polyethylene terephthalate prepared by the same production method as the above thermoplastic resin (A) except that aggregated silica particles are added, and the structure Acetic anhydride was reacted with 39.5 mol% of the formula (1), 7.0 mol% of the structural formula (3), and 7.0 mol% of the structural formula (8) to acylate the phenolic hydroxyl group. Thereafter, a liquid crystalline polyester chip obtained by performing a deacetic acid polycondensation reaction was used. This liquid crystal polyester chip exhibited the following characteristics. [Melting point: 216 ° C., liquid crystal starting temperature: 168 ° C., melt viscosity: 41 Pa · s (shear rate 100 (s ⁻¹ )), 17 Pa · s (shear rate 1000 (s ⁻¹ ))]
The thermoplastic resins (A) and (B) are dried under vacuum conditions at 150 ° C. for 5 hours, and then supplied to separate extruders set at a cylinder temperature of 260 ° C. (hopper side) to 280 ° C. (tip side). It was melted and merged into 9 layers with a feed block. The joined thermoplastic resins (A) and (B) are supplied to a static mixer having three stages of execution, and are structured in which 65 layers of thermoplastic resin A and 64 layers of thermoplastic resin B are alternately stacked in the thickness direction. It was. Moreover, the thermoplastic resin A was both surface layers, and the lamination thickness ratio was adjusted by the discharge amount so that A / B = 1. The thus obtained laminate consisting of a total of 129 layers is supplied to a T-die and formed into a sheet shape, and is then brought into close contact with a chromium plating roll maintained at 25 ° C. by an electrostatic application casting method at an applied voltage of 7 kV. Cooled and solidified. Thereafter, the film was stretched uniaxially in the longitudinal direction at 100 ° C. due to the difference in roll speed, and then stretched at 110 ° C. in the width direction with a tenter. The draw ratio is as shown in the table. Thereafter, the biaxially stretched film was heat-treated at 230 ° C. in the tenter, uniformly cooled, and then cooled to room temperature to obtain a wound thermoplastic resin film.

(Example 2)
A thermoplastic resin (A) and a mesogenic group-containing thermoplastic resin (B) were obtained in the same manner as in Example 1.
The thermoplastic resins (A) and (B) are dried under vacuum conditions at 150 ° C. for 5 hours, and then supplied to separate extruders set at a cylinder temperature of 260 ° C. (hopper side) to 280 ° C. (tip side). It was melted and merged into three layers with a feed block. The joined thermoplastic resins (A) and (B) are supplied to a static mixer having three stages of execution, and a laminate composed of 17 layers of thermoplastic resin (A) and 16 layers of (B) is laminated thickness ratio A / B = It discharged so that it might be set to 5. The thus obtained laminate consisting of a total of 33 layers was supplied to a T-die and formed into a sheet shape, and was then brought into close contact with a chromium plating roll maintained at 25 ° C. by an electrostatic application casting method at an applied voltage of 7 kV. Cooled and solidified. Thereafter, the film was stretched uniaxially in the longitudinal direction at 100 ° C. due to the difference in roll speed, and then stretched at 110 ° C. in the width direction with a tenter. The draw ratio is as shown in the table. Thereafter, the biaxially stretched film was heat-treated in the tenter at 230 ° C., uniformly cooled, cooled to room temperature, and wound up to obtain a thermoplastic resin film.

(Example 3)
A thermoplastic resin (A) and a mesogenic group-containing thermoplastic resin (B) were obtained in the same manner as in Example 1.
The thermoplastic resins (A) and (B) are dried under vacuum conditions at 150 ° C. for 5 hours, and then supplied to separate extruders set at a cylinder temperature of 260 ° C. (hopper side) to 280 ° C. (tip side). It was melted and merged into three layers with a feed block. The joined thermoplastic resins (A) and (B) are supplied to a static mixer having two stages of execution, and a laminate composed of 9 layers of thermoplastic resin (A) and 8 layers of (B) is laminated thickness ratio A / B = It discharged so that it might be set to 5. After supplying a total of 17 layers thus obtained to a T-die and forming it into a sheet, it was brought into close contact with a chromium plating roll maintained at 25 ° C. by an electrostatic application casting method at an applied voltage of 7 kV. Cooled and solidified. Thereafter, the film was stretched uniaxially in the longitudinal direction at 100 ° C. due to the difference in roll speed, and then stretched at 110 ° C. in the width direction with a tenter. The draw ratio is as shown in the table. Thereafter, the biaxially stretched film was heat-treated in the tenter at 230 ° C., uniformly cooled, cooled to room temperature, and wound up to obtain a thermoplastic resin film.

Example 4
A thermoplastic resin (A) and a mesogenic group-containing thermoplastic resin (B) were obtained in the same manner as in Example 1.
The thermoplastic resins (A) and (B) are dried under vacuum conditions at 150 ° C. for 5 hours, and then supplied to separate extruders set at a cylinder temperature of 260 ° C. (hopper side) to 280 ° C. (tip side). It was melted and merged into three layers with a feed block. The joined thermoplastic resins (A) and (B) are supplied to a static mixer having one stage of execution, and a laminate composed of 5 layers of thermoplastic resin (A) and 4 layers of (B) is laminated thickness ratio A / B = It discharged so that it might be set to 5. The thus obtained laminate consisting of a total of 9 layers was supplied to a T-die and formed into a sheet shape, and then adhered to a chromium plating roll maintained at 25 ° C. by an electrostatic application casting method at an applied voltage of 7 kV. Cooled and solidified. Thereafter, the film was stretched uniaxially in the longitudinal direction at 100 ° C. due to the difference in roll speed, and then stretched at 110 ° C. in the width direction with a tenter. The draw ratio is as shown in the table. Thereafter, the biaxially stretched film was heat-treated in the tenter at 230 ° C., uniformly cooled, cooled to room temperature, and wound up to obtain a thermoplastic resin film.

(Example 5)
A thermoplastic resin (A) was obtained in the same manner as in Example 1. The mesogenic group-containing thermoplastic resin (B) was prepared in the same manner as in Example 1 with the structural formula (1) of 39.5 mol%, the structural formula (4) of 7.0 mol%, and the structural formula (8) of 7 A liquid crystalline polyester chip comprising 0.0 mol% and 46.5 mol% polyethylene terephthalate was obtained. This liquid crystal polyester chip showed the following characteristics [melting point: 215 ° C., liquid crystal starting temperature: 163 ° C., melt viscosity 23 Pa · s (shear rate 100 (s ⁻¹ )), 10 Pa · s (shear rate 1000 (s ^{− 1} ))].
A total of 129 layers of the thermoplastic resins (A) and (B) were obtained using the same apparatus and method as in Example 1.

(Example 6)
A thermoplastic resin (A) was obtained in the same manner as in Example 1. Further, the mesogenic group-containing thermoplastic resin (B) was prepared in the same manner as in Example 1 with the structural formula (2) of 47.5 mol%, the structural formula (5) of 7.0 mol%, and the structural formula (8) of 7 A liquid crystalline polyester chip comprising 0.0 mol% and polyethylene terephthalate of 44.5 mol% was obtained. This liquid crystal polyester chip exhibited the following characteristics. (Melting point: 224 ° C., liquid crystal starting temperature: 178 ° C., melt viscosity 29 Pa · s (shear rate 100 (s ⁻¹ )), 12 Pa · s (shear rate 1000 (s ⁻¹ ))). A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) using the same apparatus and method as in Example 1. At this time, the thermoplastic resin (A) and the thermoplastic resin (B) were discharged such that the lamination thickness ratio was A / B = 3.

(Example 7)
A thermoplastic resin (A) was obtained in the same manner as in Example 1. The mesogenic group-containing thermoplastic resin (B) was prepared in the same manner as in Example 1 with the structural formula (2) being 49 mol%, the structural formula (6) being 7.0 mol%, and the structural formula (9) being 7.0. A liquid crystalline polyester chip comprising mol% and polyethylene terephthalate was 37 mol% was obtained. This liquid crystal polyester chip exhibited the following characteristics. [Melting point: 230 ° C., liquid crystal starting temperature: 184 ° C., melt viscosity 39 Pa · s (shear rate 100 (s ⁻¹ )), 17 Pa · s (shear rate 1000 (s ⁻¹ ))]. A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) using the same apparatus and method as in Example 1. At this time, the thermoplastic resin (A) and the thermoplastic resin (B) were discharged such that the lamination thickness ratio was A / B = 4.

(Example 8)
A thermoplastic resin (A) was obtained in the same manner as in Example 1. Further, the mesogenic group-containing thermoplastic resin (B) was prepared in the same manner as in Example 1 with the structural formula (2) of 53.5 mol%, the structural formula (7) of 7.0 mol%, and the structural formula (10) of 7 A liquid crystalline polyester chip comprising 0.0 mol% and 32.5 mol% polyethylene terephthalate was obtained. [Melting point: 252 ° C., liquid crystal starting temperature: 197 ° C., melt viscosity 56 (shear rate 100 (s ⁻¹ )), 22 Pa · s (shear rate 1000 (s ⁻¹ ))]. A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) using the same apparatus and method as in Example 1. At this time, the thermoplastic resin (A) and the thermoplastic resin (B) were discharged such that the lamination thickness ratio was A / B = 5.

Example 9
A thermoplastic resin (A) was obtained in the same manner as in Example 1. Further, the mesogenic group-containing thermoplastic resin (B) was prepared in the same manner as in Example 1 with the structural formula (2) of 53.5 mol%, the structural formula (5) of 7.0 mol%, and the structural formula (8) of 7 A liquid crystalline polyester chip comprising 0.0 mol% and 32.5 mol% polyethylene terephthalate was obtained. [Melting point: 249 ° C., liquid crystal starting temperature: 194 ° C., melt viscosity 54 (shear rate 100 (s ⁻¹ )), 22 Pa · s (shear rate 1000 (s ⁻¹ ))]. A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) using the same apparatus and method as in Example 1. At this time, the thermoplastic resin (A) and the thermoplastic resin (B) were discharged such that the lamination thickness ratio was A / B = 1.

(Example 10)
The manufacturing method of the thermoplastic resin (A) is 65 mol% polyethylene terephthalate prepared by the same manufacturing method as the thermoplastic resin (A) of Example 1 except that the aggregated silica particles are added, and the structural formula (1) 21 mol%, 7.0 mol% of (3), 7.0 mol% of (8) were reacted with acetic anhydride to acylate the phenolic hydroxyl group, and then obtained by performing a deacetic acid polycondensation reaction. The obtained liquid crystalline polyester chip was obtained. [Melting point: 209 ° C., liquid crystal starting temperature: 161 ° C., melt viscosity 21 (shear rate 100 (s ⁻¹ )), 9 Pa · s (shear rate 1000 (s ⁻¹ ))]. Further, the thermoplastic resin (B) was obtained in the same manner as in Example 1. A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) by the same apparatus and method as in Example 2. At this time, the thermoplastic resin (A) and the thermoplastic resin (B) were discharged such that the lamination thickness ratio was A / B = 5.

(Example 11)
The manufacturing method of the thermoplastic resin (A) is 85 mol% of polyethylene terephthalate prepared by the same manufacturing method as that of the thermoplastic resin (A) of Example 1 except that aggregated silica particles are added, and the structural formula (1) is 1 0.0 mol%, 7.0 mol% of (3) and 7.0 mol% of (8) are reacted with acetic anhydride to acylate the phenolic hydroxyl group, followed by a deacetic acid polycondensation reaction. The obtained liquid crystalline polyester chip was obtained. (Melting point: 197 ° C., liquid crystal starting temperature: 156 ° C., melt viscosity 19 (shear rate 100 (s ⁻¹ )), 7 Pa · s (shear rate 1000 (s ⁻¹ ))). Further, the thermoplastic resin (B) was obtained in the same manner as in Example 1. A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) by the same apparatus and method as in Example 2. At this time, the thermoplastic resin (A) and the thermoplastic resin (B) were discharged such that the lamination thickness ratio was A / B = 5.

(Comparative Example 1)
A thermoplastic resin (A) was obtained in the same manner as in Example 1. The thermoplastic resin (A) was dried under vacuum conditions at 150 ° C. for 5 hours, and then supplied to a separate extruder set at a cylinder temperature of 260 ° C. (hopper side) to 280 ° C. (tip side) to be melted. Then, it was made to join 3 layers with a feed block. The joined thermoplastic resin (A) was supplied to a static mixer having three execution stages, and was laminated alternately in the thickness direction. In the same manner as in Example (1), a laminate consisting of a total of 33 layers was supplied to a T-die and formed into a sheet shape, and then adhered onto a chromium plating roll maintained at 25 ° C. by an electrostatic application casting method at an applied voltage of 7 kV. And solidified by cooling. Thereafter, the film was stretched uniaxially in the longitudinal direction at 100 ° C. due to the difference in roll speed, and then stretched at 110 ° C. in the width direction with a tenter. Thereafter, the biaxially stretched film was heat-treated in the tenter at 230 ° C., uniformly cooled, cooled to room temperature, and wound up to obtain a thermoplastic resin film.

(Comparative Example 2)
A thermoplastic resin (A) was obtained in the same manner as in Example 1. Further, the mesogenic group-containing thermoplastic resin (B) was prepared in the same manner as in Example 1 with the structural formula (2) of 39.5 mol%, the structural formula (5) of 7.0 mol%, and the structural formula (10) of 7 A liquid crystalline polyester chip comprising 0.0 mol% and 46.5 mol% polyethylene terephthalate was obtained. This liquid crystal polyester chip exhibited the following characteristics. [Melting point: 217 ° C., liquid crystal starting temperature: 167 ° C., melt viscosity 29 (shear rate 100 (s ⁻¹ )), 10 Pa · s (shear rate 1000 (s ⁻¹ ))]. The thermoplastic resins (A) and (B) are dried under vacuum conditions at 150 ° C. for 5 hours, and then supplied to separate extruders set at a cylinder temperature of 260 ° C. (hopper side) to 280 ° C. (tip side). It was melted and merged into three layers with a feed block. This laminate was supplied to a T-die and formed into a sheet shape, and was then brought into close contact with a chromium plating roll maintained at 25 ° C. by an electrostatic application casting method at an applied voltage of 7 kV and solidified by cooling. Thereafter, the film was stretched uniaxially in the longitudinal direction at 100 ° C. due to the difference in roll speed, and then stretched at 110 ° C. in the width direction with a tenter. Thereafter, the biaxially stretched film was heat-treated in the tenter at 230 ° C., uniformly cooled, cooled to room temperature, and wound up to obtain a thermoplastic resin film.

(Comparative Example 3)
60 mol% of polyethylene terephthalate, 26 mol% of structural formula (1), and 7.0 of (3) prepared by the same production method as the thermoplastic resin (A) of Example 1 except that the agglomerated silica particles are added. A liquid crystalline polyester chip obtained by reacting 7.0 mol% of (%) and acetic anhydride with 7.0 mol% of (8) to acylate the phenolic hydroxyl group and then performing a deacetic acid polycondensation reaction was obtained. [Melting point: 212 ° C., liquid crystal starting temperature: 164 ° C., melt viscosity 27 (shear rate 100 (s ⁻¹ )), 9 Pa · s (shear rate 1000 (s ⁻¹ ))]. Further, the thermoplastic resin (B) was obtained in the same manner as in Example 1. A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) by the same apparatus and method as in Example 2. At this time, the thermoplastic resin (A) and the thermoplastic resin (B) were discharged such that the lamination thickness ratio was A / B = 5.

(Comparative Example 4)
A mesogen group-containing thermoplastic resin (B) was obtained in the same manner as in Example 1. The thermoplastic resin (B) is supplied to a small extruder set at a cylinder temperature of 260 ° C. (hopper side) to 280 ° C. (tip side), melted, then supplied to a T die and molded into a sheet, and then applied. A thermoplastic resin film was obtained by closely contacting and solidifying on a chrome plating roll maintained at 25 ° C. by an electrostatic application casting method at a voltage of 7 kV.

  Tables 1 and 2 show the results of evaluating the gas barrier properties and the strength and elongation of the films obtained in the above Examples and Comparative Examples. In the table, the numbers in parentheses in the types of mesogens correspond to the numbers in the above structural formula.

(Example 12)
In the same manner as in Example 1, a thermoplastic resin film was obtained. The obtained film was sampled to 200 mm × 200 mm and heated and pressed under the conditions of 220 ° C., 30 kg / cm ² and 60 s to obtain a thermoplastic resin film having a low porosity. At that time, a Kapton film (type: 500 V) manufactured by Toray DuPont Co., Ltd. was placed on the top and bottom of the sample, and the top and bottom were further sandwiched with steel plates, and pressed uniformly.
(Example 13)
A thermoplastic resin (A) was obtained in the same manner as in the examples. As the thermoplastic resin (B) containing a mesogenic group, 46.5 mol% of polyethylene terephthalate prepared by the same production method as the above thermoplastic resin (A) except that aggregated silica particles are added, and the structure Acetic anhydride was reacted with 39.5 mol% of the formula (1), 7.0 mol% of the structural formula (3), and 7.0 mol% of the structural formula (8) to acylate the phenolic hydroxyl group. Thereafter, a liquid crystalline polyester chip obtained by performing a deacetic acid polycondensation reaction was used. This liquid crystal polyester chip exhibited the following characteristics. [Melting point: 216 ° C., liquid crystal starting temperature: 168 ° C., melt viscosity: 11 Pa · s (shear rate 100 (s ⁻¹ )), 6 Pa · s (shear rate 1000 (s ⁻¹ ))]
A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) using the same apparatus and method as in Example 1.
(Example 14)
A thermoplastic resin (A) was obtained in the same manner as in the examples. As the thermoplastic resin (B) containing a mesogenic group, 46.5 mol% of polyethylene terephthalate prepared by the same production method as the above thermoplastic resin (A) except that aggregated silica particles are added, and the structure Acetic anhydride was reacted with 39.5 mol% of the formula (1), 7.0 mol% of the structural formula (3), and 7.0 mol% of the structural formula (8) to acylate the phenolic hydroxyl group. Thereafter, a liquid crystalline polyester chip obtained by performing a deacetic acid polycondensation reaction was used. This liquid crystal polyester chip exhibited the following characteristics. [Melting point: 216 ° C., liquid crystal starting temperature: 168 ° C., melt viscosity: 67 Pa · s (shear rate 100 (s ⁻¹ )), 27 Pa · s (shear rate 1000 (s ⁻¹ ))]
A thermoplastic resin film was obtained from the thermoplastic resins (A) and (B) using the same apparatus and method as in Example 12. The results for Examples 1 and 12-14 are summarized in Tables 3 and 4.

  According to the present invention, since a thermoplastic resin film having excellent transparency and design properties and high barrier properties even under high humidity can be obtained, a film suitable for packaging applications such as foods, pharmaceuticals, and cosmetics is provided. Can do. Specifically, it can be used for development in pouch-type containers, metal can laminate films, strip packaging, and the like.

Claims (7)

Five or more thermoplastic resin (B) layers containing 0.1 mol% or more of mesogenic groups and five or more thermoplastic resin (A) layers having a mesogenic group content of 35 mol% or less are laminated alternately without interposing an adhesive layer. A thermoplastic resin film characterized in that the mesogenic group content in the thermoplastic resin (B) is greater than the mesogenic group content in the thermoplastic resin (A). The thermoplastic resin film according to claim 1, wherein the content of mesogenic groups in the thermoplastic resin (A) is 15 mol% or less. The thermoplastic resin film according to claim 1 or 2, wherein the main component of the thermoplastic resin is polyester. The thermoplastic resin film according to any one of claims 1 to 3, wherein the mesogenic group is at least one selected from hydroxy aromatic carboxylic acids, aromatic dicarboxylic acids, and aromatic dihydroxy compounds. The thermoplastic resin film according to any one of claims 1 to 4, wherein the thermoplastic resin film is biaxially stretched. The difference in melt viscosity between the thermoplastic resin (A) and the thermoplastic resin (B) under the conditions of a temperature of 280 ° C. and a shear rate of 100 (s ⁻¹ ) is 150 Pa · s or less. The thermoplastic resin film according to any one of 5. The thermoplastic resin film according to claim 1, wherein the porosity of the film is less than 3%.