JP2002166459A - Method for manufacturing thermoplastic resin film, thermoplastic resin film, and liquid crystal display element substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thermoplastic resin film capable of being used as a liquid crystal element substrate having excellent optical characteristics. SOLUTION: In the method for manufacturing the thermoplastic resin film by laminating a thermoplastic resin B on both surfaces of a thermoplastic resin A with a glass transition temperature of >=150 deg.C in a peelable state by melt coextrusion and peeling the laminated thermoplastic resin B, at least one compound selected from polysiloxane, a metal salt of a fatty acid, alkyl sulfate and a fluorine modified polymer is added in an amount of 5-5,000 ppm to perform melt extrusion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic resin film and to a thermoplastic resin film. The present invention relates to a method for producing a thermoplastic resin film and a thermoplastic resin film thereof.

[0002]

2. Description of the Related Art Conventionally, thermoplastic resins having a high glass transition temperature and excellent optical properties have been industrially applied to various fields. In recent years, application to liquid crystal display devices, particularly liquid crystal display device substrates, utilizing optical characteristics has been studied as one of the uses. In recent years, liquid crystal display elements of portable information terminals have been developed by utilizing the properties of thermoplastic resins that are light and do not break, and liquid crystal display element substrates capable of color display have been demanded.

[0003] When such a thermoplastic resin is used for a liquid crystal display element substrate, it is required to have the same characteristics as those of conventionally used glass. That is, heat resistance and the like that can withstand processes such as lamination of a transparent electrode and an alignment film having optical characteristics such as colorless transparency and high light transmittance are required. Since many of these characteristics are caused by the inherent characteristics of the resin, various thermoplastic resins having excellent optical characteristics and heat resistance have been developed.

For example, norbornene polymers (US Pat. No. 2,883,372, JP-A-1-14738, etc.) and ring-opened polymers of dicyclopentadiene (JP-B-58-43412, JP-A-63-218727). Official Gazette and the like). Since these thermoplastic resins have a high glass transition point, are colorless and transparent, and have a high light transmittance, they are suitable as liquid crystal display element substrates.

However, when these thermoplastic resins are formed into a film by a melt extrusion method, a streak-like defect called a die streak tends to appear, and if the die is frequently cleaned to remove the defect, the production efficiency is very poor. Had the disadvantage of becoming

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a thermoplastic resin film suitably used as a liquid crystal display element substrate, wherein the thermoplastic resin film has no surface defects such as die streaks on the film surface. It is to provide a manufacturing method of.

Another object of the present invention is to provide a liquid crystal display element substrate having excellent optical characteristics without color unevenness and defects.

[0008]

That is, the method for producing a thermoplastic resin film of the present invention has a glass transition temperature of 15
After laminating the thermoplastic resin B on both surfaces of the thermoplastic resin A at 0 ° C. or higher by melt co-extrusion in a releasable state, the thermoplastic resin film is obtained by peeling the thermoplastic resin B to obtain a thermoplastic resin film. In the production method, a thermoplastic resin film characterized in that at least one compound selected from a polysiloxane, a metal salt of a fatty acid, an alkyl sulfate, and a fluorine-modified polymer is contained in an amount of 5 to 5,000 ppm and melt-extruded. It is a manufacturing method.

The film obtained by the method for producing a thermoplastic resin film of the present invention is suitable for a liquid crystal display device substrate, and is excellent in optical properties free from color unevenness and defects using the thermoplastic resin film. A liquid crystal display element substrate can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Thermoplastic resin A in the present invention
In order to be mainly used as a liquid crystal display element substrate, it is necessary that the glass transition temperature is 150 ° C. or higher, preferably 160 ° C. or higher. When the glass transition temperature is lower than 150 ° C., there is a problem that the film is deformed in a process of manufacturing a liquid crystal display element, for example, in a process of forming a transparent electrode or an alignment film. The glass transition temperature of the thermoplastic resin A is preferably in a range up to about 300 ° C.

As the thermoplastic resin A, alicyclic polyolefin, polyarylate, polysulfone, polyethersulfone, polycarbonate and the like are preferably used.
An alicyclic polyolefin is particularly preferably used in terms of optical characteristics. Specific examples of the alicyclic polyolefin include a polymer having a structural unit represented by the following general formula [formula 1] and / or general formula [formula 2].

[0012]

Embedded image _{(Wherein, R 1, R 2, R} 3, R 4 is hydrogen, a hydrocarbon residue or a halogen, ester, nitrile, a polar group such as a pyridyl may be the same or different each, R _1, R ₂ , R ₃ and R ₄ may form a ring with each other; m is a positive integer; n and q are 0 or a positive integer.

[0013]

Embedded image _{(Wherein, R 5, R 6, R} 7, R 8 are hydrogen, a hydrocarbon residue or a halogen, ester, nitrile, a polar group such as a pyridyl may be the same or different from each other, R _5, R ₆ , R ₇ and R ₈ may form a ring with each other, k is a positive integer, l and p are 0 or a positive integer.) It is represented by the above general formula [Formula 1]. As a monomer, a polymer having a structural unit of, for example, norbornene and an alkyl and / or alkylidene-substituted product thereof, for example, 5-methyl-2-norbornene, 5,6 dimethyl-
2-norbornene, 5-ethyl-2-norbornene, 5
-Butyl-2-norbornene, 5-ethylidene-2-norbornene and the like: dicyclopentadiene, 2,3-dihydrodicyclopentadiene, their alkyl-substituted products such as methyl, ethyl, propyl and butyl, and polar groups such as halogen Substituents: dimethanooctahydronaphthalene, its alkyl and / or alkylidene substituents, and polar substituents such as halogens, for example, 6-methyl-1,
4: 5,8-Dimethano-1,4,4a, 5,6,7,
8,8a-octahydronaphthalene, 6-ethyl-1,
4: 5,8-Dimethano 1,4,4a, 5,6,7,8,
8a-octahydronaphthalene, 6-ethylidene-1,
4: 5,8-Dimethano-1,4,4a, 5,6,7,
8,8a-octahydronaphthalene, 6-chloro-1,
4: 5,8-Dimethano-1,4,4a, 5,6,7,
8,8a-octahydronaphthalene, 6-cyano-1,
4: 5,8-Dimethano-1,4,4a, 5,6,7,
8,8a-octahydronaphthalene, 6-pyridyl-
1,4: 5,8-dimethano-1,4,4a, 5,6,
7,8,8a-octahydronaphthalene, 6-methoxycarbonyl-1, 4: 5,8-dimethano-1,4,4
a, 5, 6, 7, 8, 8a-octahydronaphthalene and the like: cyclopentadiene trimer to tetramer, for example, 4,
9: 5,8-Dimethano-3a, 4,4a, 5,8,8
a, 9, 9a-octahydro-1H-benzoindene,
4, 11: 5, 10: 6, 9-trimethano-3a, 4,
4a, 5, 5a, 6, 9, 9a, 10, 10a, 11,
It is produced by using one or more kinds of 11a-dodecahydro-1H-cyclopentaanthracene and the like, and subjecting a ring-opened polymer obtained by polymerization by a known ring-opening polymerization method to hydrogenation by an ordinary hydrogenation method. It is a polymer.

In order to set the glass transition temperature of the target hydrogenated ring-opening polymer (saturated polymer) to 150 ° C., use tetramer or pentamer among these norbornene monomers, It is preferable to use these as main components and to use them together with a bicyclic or tricyclic monomer. In particular, from the viewpoint of birefringence, it is preferable to use a tetracyclic lower alkyl-substituted or alkenyl-substituted compound as a main component.

The polymer having the structural unit represented by the general formula [Chemical Formula 2] is obtained by subjecting at least one of the above-mentioned norbornene-based monomers and ethylene to addition polymerization by a known method. And / or hydrogenated products thereof, all of which are saturated polymers.

The alicyclic polyolefin is used as a molecular weight regulator in a process for producing a polymer having a structural unit represented by the above general formula [1] and / or the general formula [2]. 1-pentene, an α-olefin such as 1-hexene, or cyclopropene, cyclobutene, cyclopentene, cycloheptene,
It may be a polymer copolymerized by adding other monomer components such as cycloolefin such as cyclooctene and 5,6-dihydrocyclopentadiene as small components. These alicyclic polyolefins include J
Preferred examples include "ARTON" (registered trademark) of SR Co., Ltd., "ZEONOR" and "ZEONEX" (all registered trademarks) of ZEON CORPORATION, "APEL" (registered trademark) of Mitsui Chemicals, Inc. Is done.

The number-average molecular weight of these alicyclic polyolefins measured by GPC (gel permeation chromatography) analysis using cyclohexane as a solvent is from 100,000 to 300,000, preferably from 2 to 200,000.
It is ten thousand. When the unsaturated bonds remaining in the molecular chain are saturated by hydrogenation, the hydrogenation ratio is preferably at least 90%, more preferably at least 95%, even more preferably at least 99%. By being a saturated polymer, thermal dimensional stability is improved.

The preferred melt viscosity of the alicyclic polyolefin of the present invention is a shear rate of 100 (sec ^-1 ), 280 ° C.
1.5 × 10 ⁴ poise or less, preferably 1.0 ×
10 ⁴ poise or less, more preferably 0.8 × 10 ⁴ poise
The characteristics are particularly good in the following cases.

As the alicyclic polyolefin of the present invention, only one kind may be used, or two or more kinds may be used. The alicyclic polyolefins may be of the same species but different in molecular weight. Further, an antioxidant, an antistatic agent, a lubricant, a surfactant, an ultraviolet absorber and the like may be added to the alicyclic polyolefin of the present invention.

In the present invention, the above-mentioned thermoplastic resin A
The resin is melt-extruded by adding at least one compound selected from a polysiloxane, a metal salt of a fatty acid, an alkyl sulfate, and a fluorine-modified polymer to a thermoplastic resin B described below.

The polysiloxane used in the present invention is a polymer having a siloxane bond, and typical examples include polydimethylsiloxane, polyphenylsiloxane, polydiphenylsiloxane and the like. Representative examples of fatty acid metal salts include calcium stearate, zinc stearate, aluminum stearate, magnesium stearate, calcium palmitate, zirconyl octylate, sodium laurate, lithium acetate, manganese acetate, and magnesium acetate. In the case of the present invention, calcium stearate and manganese acetate magnesium acetate are particularly preferably used.

Examples of the alkyl sulfate salt in the present invention include sodium cetyl sulfate, triethanolamine lauryl sulfate, sodium lauryl sulfate, laurine sulfate, oleyl sulfate and the like. As the fluorine-modified polymer, at least one kind such as styrene, vinyl acetate, methyl methacrylate, methyl acrylate, and acrylic acid is copolymerized, and furthermore, fluorine is added to 0.1%.
So-called surfactants having a group having 1 to 10 mol% at the side chain or terminal of the polymer are preferred. Representative fluorine-modified polymers include poly (perfluoroalkyl acrylate), poly (perfluoroalkyl methacrylate), poly (2,2,2-trifluoroethyl methacrylate), and the like.

The content of these compounds is from 5 to 5,000.
It must be within the range of 0 ppm. Preferably, it is 15 to 2,000 ppm. By adding these compounds in specific amounts, the releasability of the molten polymer and the die,
It is considered that the releasability was improved and the effect of preventing adhesion on the surface of the die was exhibited. If the content exceeds 5,000 ppm, defects such as foreign matter may occur in the film, or surface defects may occur due to uneven flow during polymer melting. On the other hand, if the content is less than 5 ppm, the effect of preventing die streaks does not appear. In addition, at the start of melt extrusion, after coating the inside of the die with a relatively high concentration, preferably 100 ppm or more, the effect of preventing the die streak can be further improved by forming a film with the content within the above range. it can.

In the production process of the thermoplastic resin film of the present invention, it is necessary that the film composed of the thermoplastic resin A is laminated on at least one surface of the film composed of the thermoplastic resin A in a releasable state. Since the thermoplastic resin A has a high viscosity at the time of melting, the retardation is likely to be large when a thick film is formed by melt forming. However, the letter A is obtained by laminating a film made of the thermoplastic resin B from a flow analysis at the time of melting. The size can be reduced. As a method of laminating the thermoplastic resin A and the thermoplastic resin B, it is preferable that the thermoplastic resin A and the thermoplastic resin B are laminated in a die or an adapter at the time of melting, and are co-extruded. In order to cast the thermoplastic resin (polymer) melt-extruded stably, it is preferable that the thermoplastic resin A and the thermoplastic resin B are uniformly laminated in the width direction except for the end of the film.

The thickness of the thermoplastic resin B is preferably 2 μm or more, more preferably 10 μm or more, from the viewpoint of retardation. The normally used thickness has an upper limit of 100 μm in consideration of the rigidity of the film and the like. Also,
The peeling force between the films of the thermoplastic resin A and the thermoplastic resin B is preferably less than 100 g / cm and 0.05 g / cm or more, more preferably less than 50 g / cm and 0.2 g / cm or more. If the peeling force is 100 g / cm or more, the thermoplastic resin B cannot be easily peeled off, while 0.05 g / c
If it is less than m, peeling may occur during the film forming process. The peel force is
It depends on the crystallinity and crystallinity of the laminated resin used.

As the thermoplastic resin B used in the present invention, when an alicyclic polyolefin is used as the thermoplastic resin A, polyester, polycarbonate, polyamide, or a mixture thereof is preferably used in terms of releasability.

The thermoplastic resin B used in the present invention may contain inert particles. Examples of the inert particles include silica, alumina, calcium carbonate, calcium phosphate, barium sulfate, magnesium oxide, zinc oxide and titanium oxide. And inorganic polymer particles such as crosslinked polystyrene particles and acrylic particles. Further, if necessary, a flame retardant, a heat stabilizer, a plasticizer, an antioxidant, an ultraviolet absorber, an antistatic agent, an organic lubricant such as a pigment, a fatty acid ester, and a wax may be blended. You may use together.

In the present invention, at least one compound selected from the group consisting of a polysiloxane, a metal salt of a fatty acid, an alkyl sulfate and a fluorine-modified polymer is contained in either thermoplastic resin A or thermoplastic resin B. It may be contained in both. However, when the film made of the thermoplastic resin A is laminated on at least one surface of the film made of the thermoplastic resin A in a releasable state, it is contained in the thermoplastic resin B. It is preferable not to include it in the thermoplastic resin A in advance.

In the present invention, the thickness of the film made of the thermoplastic resin A is preferably 100 μm or more. When the thickness is less than 100 μm, the rigidity of the film is small, so that the film is deformed in the manufacturing process of the liquid crystal display element, and the thermal dimensional stability is not obtained, so that it becomes difficult to manufacture the liquid crystal display element. The thickness of the film is approximately 2000 μm as an upper limit that can be produced industrially without any problem in quality.
It is about. As a method of controlling the film thickness,
Various known methods can be used, but it is common to install a metering pump (specifically, a gear pump or the like) in the middle of the polymer pipe.

The retardation of the film made of the thermoplastic resin A is preferably 20 nm or less. Preferably 15 nm or less, more preferably 10 nm
Or less, more preferably 5 nm or less. By setting the retardation within the above range, colorless transparency can be maintained even when used as a liquid crystal display element substrate capable of performing color display. The lower limit of retardation is 0
nm, which is the goal. The meaning of the retardation is the in-plane anisotropy of the refractive index, and is defined by the product of the difference in the refractive index in the direction orthogonal to the in-plane and the film thickness.

Next, a method for producing the thermoplastic resin film of the present invention will be described.

In the present invention, at least one compound selected from the group consisting of a polysiloxane, a metal salt of a fatty acid, an alkyl sulfate, and a fluorine-modified polymer is used as a thermoplastic resin A,
As a method of adding B, a method of adding a resin at the time of polymerization, a method of preparing a master batch containing a high concentration, a blending method of adding immediately before melt extrusion, and the like are used, and a blending method is preferably used.

With respect to the thermoplastic resin A of the present invention, vacuum drying before melt extrusion is effective in terms of streaks, defects, and shades. The temperature for vacuum drying is 80 ° C
Above, preferably 100 ° C or higher and lower than 160 ° C, more preferably 110 ° C or higher and lower than 140 ° C. Also,
The pressure at the time of vacuum drying is 100 mmHg or less, preferably less than 50 mmHg, and more preferably less than 25 mmHg. The drying time is preferably 2 hours or more and less than 6 hours. By drying under the above conditions, while removing water and low molecular weight substances having a molecular weight of less than 100,
Oxygen in the resin can be removed.

In the present invention, in order to reduce defects and streaks of the film, the thermoplastic resin A immediately before melt extrusion is heated to a temperature of 8 ° C.
It is preferable to maintain the temperature at 0 ° C. or higher and the oxygen concentration at 1% or lower. The temperature is more preferably at least 90 ° C and less than 150 ° C. The oxygen concentration is more preferably 0.5% or less. In order to satisfy the above conditions, it is effective to heat the extruder hopper to the above temperature range and to seal with nitrogen.

Further, by melting the thermoplastic resin A after being supplied to the extruder under a vacuum or a nitrogen atmosphere, the stripes of the film are reduced and the color tone is improved. For melting under a vacuum or a nitrogen atmosphere, a method in which the inside of the extruder is vacuumed using a highly airtight extruder, or a method in which nitrogen is introduced immediately before the entrance of the extruder is preferably used.

On the other hand, the thermoplastic resin B is also supplied to another extruder and melted after excluding low molecular weight substances such as moisture, and is laminated with the above-mentioned melt of the thermoplastic resin A in a composite die or an adapter. At this time, it is preferable to laminate the thermoplastic resin B on both surfaces of the alicyclic polyolefin (thermoplastic resin A) in order to reduce the retardation from the flow analysis during melting. The laminated molten sheet is discharged from the lip of the thermoplastic resin base and brought into close contact with the cooling drum to obtain a cast sheet. As the casting method, a nip roll method, a calendar method, an electrostatic application contact method, an air knife method, an air chamber method, or the like can be used. Also,
As the material of the cooling drum, it is preferable to use a drum made of chrome plating or stainless steel and having a surface roughness Rmax of 0.2 μm or less. Although the surface temperature of the drum is not particularly limited, it depends on the crystallinity of the thermoplastic resin and the adhesiveness between the drum and the optical characteristics of the alicyclic polyolefin, but is preferably 20 to 180 ° C, preferably 40 to 150 ° C. Is often used. Also, the draft ratio (base discharge gap /
(Solidified film thickness ratio) is preferably 20 or less, more preferably 10 or less, because an optically isotropic film is obtained.

The thermoplastic resin B layer is peeled off from the film obtained by laminating the thermoplastic resin B on both sides of the obtained thermoplastic resin A. The thermoplastic resin A film is then peeled off, if necessary, by a known method. After forming the gas barrier layer, the hard coat layer, and the easy-adhesion layer, a transparent electrode is formed to obtain a liquid crystal display element substrate.

The gas barrier layer is not particularly limited, but may be a transparent vapor-deposited layer such as a polyvinyl alcohol film, a silica film, and an alumina film. Among them, the gas barrier properties include moisture resistance, alkali resistance, acid resistance and the like. Is required, the organic polymer compound has an average particle size of 5 to 5.
It is preferable that a large amount of an inorganic substance such as silica having a thickness of about 25 nm is added, and that the organic polymer compound layer is subjected to a crosslinking treatment with heat or an electron beam, or that the organic polymer crosslinking layer is laminated on a transparent evaporation layer. The fine particles are not particularly limited, but silica sol, antimony oxide sol, titania sol,
Alumina sol, zirconia sol, tungsten oxide sol and the like are preferably exemplified, and the average particle size of the particles is 1 to 300 nm, preferably 5 to 100 nm, more preferably 10 to 50 n in applications requiring transparency.
m. The addition content of these particles is 10 to 8
A preferred range is 5% by weight, preferably 35-70% by weight. A surfactant may be added to these layers.

Next, a hard coat film is coated on the gas barrier film. In this case, the organic polymer compound is not particularly limited, but preferably includes an epoxy resin, an acrylic resin, a urethane resin, a urea resin, a melamine resin, and modified products thereof, and has an average particle size of about 10 to 50 nm. An inorganic oxide such as silica is added in an amount of about 50 to 85% by weight, and a water / alcohol dispersion liquid containing a catalyst represented by an aluminum chelate compound as a cross-linking agent is coated as necessary. Crosslink with radiation or the like to form a hard coat layer of 3H or more.

After providing these layers, the sheet is cut into a sheet, and aging is performed by applying the appropriate load below the glass transition point by the above-described method. It is particularly preferable for improving the properties. Thus, the thermoplastic resin film for a liquid crystal display element substrate of the present invention is obtained.

[Method of Evaluating Characteristics] The method of measuring characteristic values and the method of evaluation in the present invention are as follows.

(1) Die streak The film is sampled 1 hour and 12 hours after the polymer is discharged from the die during continuous film formation.
Streak-like defects visually observed on the film were counted as die streaks. 1 hour and 12 hours after the film has no base streaks on both films ◎ 1 hour after the film has no base streaks and 12 hours after the film has one base streak ○ 1 hour after A film having two or more die streaks in the film after 12 hours without any die streaks in the film was evaluated as “Poor”, and a film having one or more die streaks after one hour passed.

(2) Foreign matter The film was cut into a size of 40 cm × 120 cm, and the surface of the film was observed by irradiating a fluorescent lamp (white light) from the opposite side of the film, and defects (foreign matter) that could be visually confirmed were counted. The observed film area is 1 m ² . Foreign object 0
The pieces were evaluated as 個, 1-2 were evaluated as Δ, and three or more were evaluated as ×.

(3) Film Thickness and Laminated Thickness After the laminated film was peeled off, each thickness was measured with a dial gauge.

(4) Glass transition temperature As a differential scanning calorimeter, DS manufactured by Seiko Denshi Kogyo KK
C (RDC220), using the company's disk station (SSC / 5200) as a data analyzer,
5 mg at 300 ° C.
After holding for 1 minute and quenching with liquid nitrogen, the temperature was raised at a rate of 20 ° C / m
Measured in. The glass transition temperature was the temperature at the midpoint of the glass transition.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.

(Example 1) As the thermoplastic resin A, an alicyclic polyolefin ("ARTON" (registered trademark) manufactured by JSR Corporation, glass transition point: 173 ° C) was used,
After drying under vacuum at 3 ° C. for 3 hours, 100 ppm of calcium stearate was added, and the mixture was supplied to an extruder A.
Melted at ℃. Separately, a polycarbonate (glass transition point: 150 ° C.) is used as the thermoplastic resin B at 140 ° C.
After drying under vacuum for 3 hours,
The extruder B was added to the extruder B at 280 ° C.
And three layers (thermoplastic resin B / thermoplastic resin A / thermoplastic resin B) are laminated in the adapter with the thermoplastic resin A supplied from the extruder A, and then discharged from the die to produce a laminated molten sheet. I got The obtained laminated molten sheet was mixed with 140
The film was brought into close contact with a cooling drum whose temperature was controlled at 0 ° C. and solidified by cooling to prepare a laminated film having a laminated thickness ratio B / A / B = 50/400/50. The thermoplastic resin B layers on both surfaces were peeled from the laminated film to obtain a thermoplastic resin A film having a thickness of 400 μm. Table 1 shows the physical properties of the obtained film.

(Example 2) Thermoplastic resin A was prepared without adding calcium stearate to alicyclic polyolefin (“Zeonor” (registered trademark) manufactured by Nippon Zeon Co., Ltd., glass transition temperature: 168 ° C). In the same manner as in Example 1 except that the amount of calcium stearate added to the thermoplastic resin B was changed to 200 ppm, the thickness was 400 μm.
Was obtained. Table 1 shows the physical properties of the obtained film.

(Example 3) As the thermoplastic resin A, an alicyclic polyolefin ("Zeonor" (registered trademark) manufactured by ZEON CORPORATION, glass transition point: 168 ° C) was used.
After vacuum drying for 200 hours, dimethylsiloxane was
The m-added product was supplied to extruder A and melted at 280 ° C. Separately, using polycarbonate (glass transition point: 150 ° C.) as the thermoplastic resin B, vacuum-drying at 140 ° C. for 3 hours, feeding the extruder B without adding dimethylsiloxane, melting at 280 ° C., and extruding After three layers (thermoplastic resin B / thermoplastic resin A / thermoplastic resin B) were laminated in the adapter with the thermoplastic resin A supplied from the machine A, it was discharged from a die to obtain a laminated molten sheet. The obtained laminated molten sheet is brought into close contact with a cooling drum controlled at a temperature of 140 ° C. to be cooled and solidified, and a laminated thickness ratio B / A / B
= 50/400/50 was prepared. The thermoplastic resin B layers on both surfaces are peeled off from the laminated film,
A thermoplastic resin A film having a thickness of 400 μm was obtained.
Table 1 shows the physical properties of the obtained film.

Comparative Example 1 A film having a thickness of 400 μm was obtained in the same manner as in Example 1 except that calcium stearate was not added to thermoplastic resin A and thermoplastic resin B. Table 1 shows the physical properties of the obtained film.

(Comparative Example 2) The amounts of calcium stearate of thermoplastic resin A and thermoplastic resin B were both 2
A film having a thickness of 400 μm was obtained in the same manner as in Example 1 except that the content was changed to 000 ppm. Table 1 shows the physical properties of the obtained film.

(Example 5) An alicyclic polyolefin ("ARTON" manufactured by JSR Corporation, glass transition point: 173 ° C) was used as the thermoplastic resin A, followed by vacuum drying at 130 ° C for 3 hours. It was fed and melted at 280 ° C. Separately,
Polycarbonate (glass transition point: 150 ° C.) was used as thermoplastic resin B, vacuum-dried at 140 ° C. for 3 hours, and 200 ppm of calcium stearate was added to extruder B, melted at 280 ° C., and extruded. After laminating three layers (thermoplastic resin B / thermoplastic resin A / thermoplastic resin B) in the adapter with the thermoplastic resin A supplied from the machine A, it was discharged from a die to obtain a laminated molten sheet.
The obtained laminated molten sheet was brought into close contact with a cooling drum controlled at a temperature of 140 ° C. and cooled and solidified to prepare a laminated film having a laminated thickness ratio B / A / B = 50/400/50. From this laminated film, thermoplastic resin B on both surfaces
The layers were peeled off to obtain a thermoplastic resin A film having a thickness of 400 μm.

A corona discharge treatment was applied to one surface of the peeled thermoplastic resin film A, reactive vapor deposition of alumina was applied as a transparent vapor-deposited layer, and 45% by weight of polyvinyl alcohol and an average particle diameter were formed on the vapor-deposited layer. 13n
m barrier coating using a water / methanol dispersion of aluminum acetylacetonate as a cross-linking agent was performed, and cured at 150 ° C. to a thickness of 1 μm.
m and wound up on a roll. A hard coat layer was further provided on the surface coated with the gas barrier layer. That is, 30% by weight of an acrylic resin and 70% by weight of spherical colloidal silica having an average particle diameter of 45 nm were cured by UV to form a hard coat layer having a thickness of 2 μm.

Similarly, on the opposite surface of the thermoplastic resin A film, a gas barrier layer and a hard coat layer are provided after peeling the thermoplastic resin, and the hard coat layer / gas barrier layer / thermoplastic resin A layer / Gas barrier layer /
A five-layer structure consisting of a hard coat layer was obtained.
The sheet was cut into pieces of 300 mm, and an appropriate load was applied to a laminated body in which 500 pieces of the sheet were stacked, and aged at 145 ° C. for 12 hours to obtain a liquid crystal display element substrate. The obtained liquid crystal display element substrate was a liquid crystal display element substrate having excellent optical characteristics without color unevenness and defects.

[0055]

[Table 1]

[0056]

According to the present invention, a non-oriented thermoplastic resin film free from defects such as die streaks can be efficiently obtained, and this thermoplastic resin film can be suitably used as a liquid crystal display device substrate. By using this thermoplastic resin film, it is possible to obtain a liquid crystal display element substrate having excellent optical properties without color unevenness and defects.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 83/04 C08L 83/04 101/00 101/00 101/04 101/04 G02F 1/1333 500 G02F 1/1333 500 // B29K 45:00 B29K 45:00 69:00 69:00 83:00 83:00 B29L 31:34 B29L 31:34 F term (reference) 2H090 JB03 JD17 4F071 AA14 AA23 AA39 AA43 AA48 AA50 AA54 AA64 AA67 AC09 AC13 AH12 BA01 BB06 BC01 4F207 AA03 AA28 AB17 AB21 AG03 AH33 KA01 KB26 KE06 KF01 KK81 KL55 KW50 4J002 BD123 BK001 CE001 CF161 CG011 CN031 CP032 EG026 EG036 EG046 EV257 GP00 GQ00

Claims (7)

[Claims] 1. A thermoplastic resin A having a glass transition temperature of 150 ° C. or higher, which is laminated on both sides by melt coextrusion in a state where the thermoplastic resin B can be peeled off, and then the thermoplastic resin B is peeled off. In a method for producing a thermoplastic resin film for obtaining a resin film, at least one compound selected from polysiloxane, a metal salt of a fatty acid, an alkyl sulfate, and a fluorine-modified polymer is used in an amount of 5 to 5.0.
A method for producing a thermoplastic resin film, wherein the thermoplastic resin film is melt-extruded at a content of 00 ppm. 2. The thermoplastic resin A contains at least one compound selected from the group consisting of polysiloxanes, metal salts of fatty acids, alkyl sulfates, and fluorine-modified polymers.
The method for producing a thermoplastic resin film according to claim 1, wherein the thermoplastic resin film is melt-extruded at a content of 5,000 ppm. 3. The thermoplastic resin B is mixed with at least one compound selected from the group consisting of polysiloxane, metal salt of fatty acid, alkyl sulfate and fluorine-modified polymer.
3. The method for producing a thermoplastic resin film according to claim 1, wherein the thermoplastic resin film is melt-extruded at a content of 5,000 ppm. 4. The thermoplastic resin film according to claim 3, wherein the thermoplastic resin A is melt-extruded without containing a polysiloxane, a metal salt of a fatty acid, an alkyl sulfate, and a fluorine-modified polymer. Production method. 5. The method for producing a thermoplastic resin film according to claim 1, wherein the thermoplastic resin A is an alicyclic polyolefin. 6. A thermoplastic resin film produced by the method according to claim 1. 7. A liquid crystal display element substrate using the thermoplastic resin film according to claim 6.