JP2002355913A - Laminated film and film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film and a film not having a defect such as foreign matter or the like and suitably used in an optical function material, particularly a liquid crystal display element. SOLUTION: The laminated film is a non-oriented film wherein a thermoplastic resin B is laminated on both surfaces of a thermoplastic resin A with a melt specific resistance of 1×10<9> Ω.cm or more in a peelable state and the absolute value of the surface potential of the thermoplastic resin A after the peeling of the thermoplastic resin B is not more than 1 kV.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film and a film, and more particularly, to a laminated film and a film having excellent optical properties and free from defects such as foreign substances and suitably used as an optical functional material.

[0002]

2. Description of the Related Art Conventionally, thermoplastic resins having excellent optical properties have been industrially applied to various fields. In recent years, liquid crystal display devices utilizing optical characteristics, particularly development to liquid crystal display device substrates, have been studied. In recent years, liquid crystal display elements of portable information terminals have been developed by taking advantage of the characteristics of being light and not cracking, and a liquid crystal display element substrate capable of color display has been demanded. When such a thermoplastic resin is used for a liquid crystal display element substrate, characteristics close to those of a conventionally used glass are required. That is, optical characteristics such as colorless and transparent, high light transmittance, and heat resistance that can withstand processes such as lamination of a transparent electrode and an alignment film are required. Many of these characteristics are caused by characteristics inherent to the type of resin, and various resins having excellent optical characteristics and heat resistance have been developed.

For example, norbornene-based polymers (USP
No. 2,883,372, JP-A-1-14738, etc.) and a ring-opened polymer of dicyclopentadiene (Japanese Patent Publication No. 58-43).
412, JP-A-63-218727, etc.). These resins have a high glass transition point, are colorless and transparent, and have a high light transmittance, so that they are suitable as liquid crystal display element substrates.

[0004]

However, when an alicyclic polyolefin such as a norbornene-based polymer or a ring-opened polymer of dicyclopentadiene is formed into a film, the film surface is charged by contact with a metal roll or a rubber roll in the film forming process. Resulting in. In addition, when the electrostatic application casting method is used as the film forming method, the charge of the film is further increased. Due to this charging, dust adheres during the film forming process, and defects such as uneven coating are caused even when performing post-processing coating.

As a result of intensive studies, the present inventors have found that by controlling the charging of the film surface, the adhesion of dust can be prevented.
The present invention has been found to provide a film having excellent optical properties without surface defects such as coating unevenness and foreign matter, and has arrived at the present invention. That is, the object of the present invention is excellent in optical properties,
Another object of the present invention is to provide a laminated film and a film which are free from defects such as foreign substances and are preferably used as an optical functional material for a liquid crystal display device or the like.

[0006]

The present invention has the following configuration to achieve the above object. That is, it is a non-oriented film laminated on both surfaces of a thermoplastic resin A having a melting specific resistance of 1 × 10 ⁹ Ω · cm or more in a state where the thermoplastic resin B can be peeled off. Thermoplastic resin A
Wherein the absolute value of the surface potential is 1 kV or less. Further, a film obtained by peeling a layer made of thermoplastic resin B from the laminated film. It is.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Thermoplastic resin A used in the present invention
Needs to have a melting specific resistance of 1 × 10 ⁹ Ω · cm or more. The melting specific resistance is an electric resistance in a state where the resin is melted, and a measuring method thereof will be described later. A resin having a melting specific resistance of less than 1 × 10 ⁹ Ω · cm is not preferable because a film having both optical characteristics and heat resistance cannot be obtained.

The thermoplastic resin A used in the present invention is not particularly restricted but includes, for example, polyethylene, polypropylene, polyolefins such as copolymers thereof, polyethylene terephthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and copolymers. Examples thereof include polyester such as polyester, alicyclic polyolefin, polyarylate, polycarbonate, polyethersulfone, and polysulfone. As the film used for the liquid crystal display element, since the glass transition point is preferably 140 ° C. or more and the light transmittance is 85% or more, alicyclic polyolefin, polyarylate, polycarbonate, polyether sulfone, and polysulfone are preferred. And more preferably an alicyclic polyolefin in terms of optical properties.

Specific examples of the alicyclic polyolefin include:
Examples of the polymer include structural polymers represented by the following chemical formulas 1 and / or 2.

[0010]

Embedded image

(Where R1, R2, R3, R4
Is a hydrogen, hydrocarbon residue or a polar group such as halogen, ester, nitrile, pyridyl, etc., which may be the same or different, and R1 and R2, R3 and R4 may form a ring with each other. m is a positive integer. n and q are 0
Or a positive integer. )

[0012]

Embedded image

(Where R5, R6, R7, R8
Is a hydrogen, hydrocarbon residue or a polar group such as halogen, ester, nitrile, pyridyl, etc., which may be the same or different, and R5 and R6, R7 and R8 may form a ring with each other. k is a positive integer. l and p are 0
Or a positive integer. Examples of the monomer used for the polymer having the structural unit represented by Chemical Formula 1 include norbornene and its alkyl and / or alkylidene-substituted product (for example, 5-methyl-2-norbornene, 5,6 dimethyl-2) -Norbornene, 5-ethyl-2-norbornene, 5-butyl-
2-norbornene, 5-ethylidene-2-norbornene, etc.), dicyclopentadiene, 2,3-dihydrodicyclopentadiene, methyl, ethyl, propyl,
Alkyl substituents such as butyl, and polar group substituents such as halogen (eg, dimethanooctahydronaphthalene, alkyl and / or alkylidene substituents thereof), and polar group substituents such as halogen (eg, 6-methyl-1, 4:
5,8-Dimethano-1,4,4a, 5,6,7,8,8
a-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, 5,6,7,8,8
a-octahydronaphthalene, 6-chloro-1,4:
5,8-Dimethano-1,4,4a, 5,6,7,8,8
a-octahydronaphthalene, 6-cyano-1,4:
5,8-Dimethano-1,4,4a, 5,6,7,8,8
a-octahydronaphthalene, 6-pyridyl-1,4:
5,8-Dimethano-1,4,4a, 5,6,7,8,8
a-octahydronaphthalene, 6-methoxycarbonyl-1,4: 5,8-dimethano-1,4,4a, 5,6,
7,8,8a-octahydronaphthalene, etc., cyclopentadiene trimer and tetramer (eg, 4,9: 5,8-dimethano-3a, 4,4a, 5,8,8a, 9,9a-octahydro) -1H-benzoindene, 4,11: 5,1
0: 6,9-trimethano-3a, 4,4a, 5,5a,
6,9,9a, 10,10a, 11,11a-dodecahydro-1H-cyclopentaanthracene) and the like. One or more of these are used and polymerized by a known ring-opening polymerization method to open. A ring polymer is obtained. The obtained ring-opened polymer is hydrogenated by an ordinary hydrogenation method to produce a polymer having the structural unit represented by Chemical Formula 1. The glass transition temperature of the polymer is preferably 160 ° C. or higher. For this purpose, a tetramer or pentamer of norbornene-based monomers is used, or a bicyclic or tricyclic compound containing these as a main component. It is preferable to use it in combination with a monomer of the form. In particular, from the viewpoint of birefringence, it is preferable that a main component be a lower alkyl-substituted or alkenyl-substituted tetramer.

Examples of the monomer used for the polymer having the structural unit represented by the chemical formula 2 include one or more of the above-mentioned norbornene-based monomers and ethylene, and these are subjected to addition polymerization by a known method. Obtain a polymer. The obtained polymer and / or a hydrogenated product thereof can be used as a polymer having a structural unit represented by Chemical Formula 2.

The alicyclic polyolefin is represented by the following chemical formula 1.
Alternatively, in the course of polymerization of the structural unit of Chemical Formula 2, as a molecular weight regulator, an α-olefin such as 1-butene, 1-pentene, or 1-hexene is added, or cyclopropene, cyclobutene, cyclopentene, cycloheptene,
It may be a polymer obtained by copolymerizing a small amount of other monomer components such as cycloolefin such as cyclooctene and 5,6-dihydrocyclopentadiene.

As the alicyclic polyolefin, for example, Arton of JSR Corporation, Zeonoa and Zeonex of Zeon Corporation, and Apel of Mitsui Chemicals, Inc. are preferably used.

The molecular weight of the alicyclic polyolefin used in the present invention is preferably such that the number average molecular weight measured by GPC (gel permeation chromatography) analysis using cyclohexane as a solvent is 1 from the viewpoint of strength.
The range is from 300,000 to 300,000, and more preferably from 200,000 to 200,000. When the unsaturated bonds remaining in the molecular chain of the alicyclic polyolefin are saturated by hydrogenation (hereinafter, sometimes referred to as hydrogenation), the hydrogenation rate is preferably 90% or more, and 95% or more. More preferably, it is 99% or more. By being a saturated polymer, weather resistance and light deterioration resistance are improved.

The alicyclic polyolefin used in the present invention may be used alone or in combination of two or more. In addition, the same species having different molecular weights may be blended. Further, an antioxidant, an antistatic agent, a lubricant, a surfactant, an ultraviolet absorber and the like may be added to the alicyclic polyolefin used in the present invention.

In the present invention, it is necessary that the absolute value of the surface potential of the thermoplastic resin A after the peeling of the thermoplastic resin B is 1 kV or less. Preferably 0.8 kV or less,
More preferably, it is 0.5 kV or less. Exceeding 1 kV is not preferred because it causes adhesion of dust and the like and uneven coating during coating.

In the present invention, as the film used for the liquid crystal display element, the thickness of the thermoplastic resin A is 30 μm.
m or more. Outside this range, the rigidity of the film is so small that the film may be deformed in the process of manufacturing the liquid crystal display element, making it difficult to manufacture the liquid crystal display element.

[0021] The thermoplastic resin B used in the present invention is not particularly limited.
Acrylic resin, polyolefin, etc. can be mentioned. Further, the thermoplastic resin B may be a resin of the same type as the thermoplastic resin A to be laminated as long as a part of the characteristics (composition, molecular weight, additives, etc.) is different, and may be a polymer alloy.

The thermoplastic resin B is preferably polyester from the viewpoint of the releasability from the thermoplastic resin A. Among them, polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, and polypropylene terephthalate are more preferably used as main components, and polyethylene terephthalate is more preferably used as main components. Here, the main component means that the content is 60 mol% or more.

The dicarboxylic acid component used as the (co) polymerization component of the polyester usable as the thermoplastic resin B includes terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, trimethyladipic acid, sebacic acid, Malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, fumaric acid, maleic acid,
Itaconic acid, 1,3-cyclopentanedicarboxylic acid, 1,
2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-naphthalic acid, diphenic acid, 4,4′-oxybenzoic acid, 2,5-naphthalenedicarboxylic acid and the like can be used. Of these, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid,
Cyclohexanedicarboxylic acid and diphenylethanedicarboxylic acid are preferably used.

The diol component used as the (co) polymerization component of the polyester usable as the thermoplastic resin B includes ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10 -Decanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1, 3-propanediol, 3-methyl-1,
5-pentanediol, 2,2,4-trimethyl-1,6
-Hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4 ′ -Thiodiphenol, bisphenol A, 4,4'-methylenediphenol, 4,4 '-(2-norbornylidene) diphenol, 4,4'-dihydroxybiphenol, o-, m
-, And p-dihydroxybenzene, 4,4'-isopropylidenephenol, 4,4'-isopropylidenebis (2,6-dichlorophenol), 2,5-naphthalenediol, p-xylenediol, cyclopentane-
1,2-diol, cyclohexane-1,2-diol,
Cyclohexane-1,4-diol and the like can be used. Of these, ethylene glycol, propylene glycol, tetramethylene glycol, and cyclohexanedimethanol are preferably used.

The polyester which can be used as the thermoplastic resin B may be obtained by copolymerizing an oxycarboxylic acid such as p-oxybenzoic acid in addition to a dicarboxylic acid component and a diol component. Branched polyesters can also be formed using ester-forming components.

The intrinsic viscosity of the polyester which can be used as the thermoplastic resin B is preferably 0.5 dl / g or more and 1.5 dl or more in view of the strength and processability of the obtained film.
/ G, more preferably 0.6 dl / g or more,
It is less than 1.0 dl / g.

In the present invention, the thermoplastic resin B preferably contains a charge control agent in an amount of preferably 0.05 to 20% by weight, more preferably 0.1 to 10% by weight.
If the content is less than 0.05% by weight, the peeling charge and the contact charge of the film become large, and foreign matter and coating unevenness tend to increase.
If it exceeds 0% by weight, the film forming property tends to decrease.

Known charge control agents can be used as the charge control agent. For example, nigrosine-based charge control agents, triphenylmethane-based charge control agents, cationic compounds such as quaternary ammonium, basic dyes such as dyes, metal salts of higher fatty acids (metal soaps), metal-containing azo compounds, salicylic acid Derivative metal compounds and the like can be used. Specifically, as a nigrosine-based charge control agent, Orient Chemical's Bontron N-01, N-13, or
Those obtained by subjecting these nigrosine-based charge control agents to vacuum heat treatment can be suitably used. Examples of triphenylmethane-based charge control agents include C.I. I. Solvent Bl
ue66, 124, C.I. I. Pigment Blue
61, 56, 19, and 18; I. So
It is more preferable to use the event blue 124. Specific examples of triphenylmethane-based charge control agents include “Copy Blue” PR and “Bri” manufactured by Hoechst.
llian Blue Base "SM, BASF Alkali manufactured by BSF Japan
Blue "NB D 6156 D LD.

Specific examples of cationic compounds such as quaternary ammonium as charge control agents include compounds in which the anion of a quaternary ammonium salt compound is an inorganic anion containing a molybdenum or tungsten atom. Here, as a specific example of the inorganic anion,
Molybdic acid, tungstic acid, phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, phosphotungsten / molybdic acid, silicotungsten / molybdic acid, phosphotungsten / molybdic acid, chromium / molybdic acid, etc. Are TP-302 and 415 manufactured by Hodogaya Chemical Co., Ltd.
And the like.

Examples of the metal-containing azo compound as a charge controlling agent include, for example, Bontron S-31, S-32, S-34, S-35, and S-3 manufactured by Orient Chemical Industries.
7, S-40, E-81, E-82, Kayaset Black T-2, 004 manufactured by Nippon Kayaku Co., Ltd., Eizen Spiron Black T-37, T-95, T manufactured by Hodogaya Chemical Industry Co., Ltd.
RH and the like.

Inert particles may be added to the thermoplastic resin A and / or the thermoplastic resin B used in the present invention. Examples of the inert particles include, but are not limited to, silica, alumina, calcium carbonate, and calcium phosphate. ,
Barium sulfate, magnesium oxide, zinc oxide, inorganic fillers such as titanium oxide and organic polymer particles (for example,
Crosslinked polystyrene particles, acrylic particles, etc.).

The thermoplastic resin A and / or the thermoplastic resin B may further contain a flame retardant, a heat stabilizer, a plasticizer, an antioxidant, an ultraviolet absorber, an antistatic agent, if necessary.
Organic lubricants such as pigments, fatty acid esters, and waxes may be blended, and two or more of these may be used in combination.

The thermoplastic resin B of the present invention preferably has a melting specific resistance of less than 5 × 10 ⁷ Ω · cm.
More preferably, it is less than 1 × 10 ⁷ Ω · cm.

In the present invention, it is necessary that the thermoplastic resin B is laminated on both surfaces of the thermoplastic resin A in a releasable state. By laminating thermoplastic resin B,
The retardation of the laminated film or the film made of the thermoplastic resin A can be reduced. further,
Surface defects such as streaks on the film and adhesion of dust can also be prevented. Further, the end portion of the laminated film is preferably a laminated film composed of only the thermoplastic resin B. By controlling the lamination state, it has become possible to form a film by an electrostatically-applicable casting method, which has not been able to adopt a thermoplastic resin having a high melting specific resistance. Here, the width of the end portion of the laminated film made of only the thermoplastic resin B is preferably 1 mm or more, more preferably 5 mm or more.

The method of laminating the thermoplastic resin B is not particularly limited, but a method of laminating in a die or an adapter at the time of melting and co-extrusion is preferred.

The peeling force between the thermoplastic resin B and the thermoplastic resin A is preferably less than 100 g / cm and not less than 0.05 g / cm, more preferably less than 50 g / cm and not less than 0.2 g / cm. If it is 100 g / cm or more, it becomes difficult to peel off the thermoplastic resin B, and if it is less than 0.05 g / cm, it may be peeled off in the film forming process.

The thickness of the thermoplastic resin B is preferably 1 μm or more, and more preferably 5 μm, in view of retardation and low resistance.
The above is more preferable, and 10 μm or more is particularly preferable.

The laminated film and the film of the present invention need to be non-oriented films.

Next, the method for producing the film of the present invention will be described, but the present invention is not limited thereto.

The content of the ultra low molecular weight volatiles having a molecular weight of less than 100 such as water, gas, melt, volatiles and decomposition products of the thermoplastic resin A is preferably reduced to 0.05% by weight or less (for example, 100 ° C.). (Vacuum drying for 1 hour or more as described above) and supply to an extruder to melt. On the other hand, the thermoplastic resin B is also supplied with another charge controlling agent together with a charge control agent and melted after excluding ultra-low molecular weight volatiles such as moisture. Charge control agent is thermoplastic resin B
There is no particular limitation on the method of supplying the mixture to the substrate. For example, a dry blend in which a charge control agent and a polymer chip are directly mixed, and a compound method in which a high concentration master polymer of the charge control agent is prepared are preferably used. The melt of the thermoplastic resin A and the thermoplastic resin B is laminated in a composite die or an adapter. At this time, it is preferable that the thermoplastic resin B is laminated on both surfaces of the thermoplastic resin A and that the end portion of the laminated film is composed of only the thermoplastic resin B in order to adhere to the cooling drum by the electrostatic application casting method.
The molten sheet of the laminated film is discharged from a die lip and brought into close contact with a cooling drum to obtain a cast sheet. This casting method is preferably an electrostatic printing method. 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. Further, the surface temperature of the cooling drum is not particularly limited, but also depends on the crystallinity of the thermoplastic resin B and the adhesion between the drum and the optical properties of the thermoplastic resin A.
Preferably it is 20-180 ° C, more preferably 25-1.
The one at 50 ° C. is used. In addition, the draft ratio is preferably as small as 20 or less, more preferably 10 or less, because an optically isotropic film is obtained.

The obtained laminated film can be used as it is, or can be used as a film made of thermoplastic resin A by peeling off thermoplastic resin B by a known method.

The use of the thermoplastic resin film of the present invention is not particularly limited, but it can be preferably used for applications requiring excellent optical properties and few defects.

Particularly preferred applications are:
That is, if necessary, a gas barrier layer, a hard coat layer, and an easy-adhesion layer are formed on the thermoplastic resin film of the present invention by a known method, and then a transparent electrode is formed, which can be used as a liquid crystal display element substrate. . Further, it can be used as a polarizer protective film by laminating on both surfaces of the polarizer, and as a touch panel support by being incorporated in a touch panel.

(Method for Evaluating Characteristics) The method for measuring and evaluating the characteristic values in the present invention is as follows.

(1) Unevenness of Application Immediately after the surface of the thermoplastic resin A is subjected to corona discharge treatment (in the atmosphere, treatment intensity = 60 W · min / m ² ), a 10% aqueous polyvinyl alcohol solution is applied to a thickness of 0.5 μm. Was applied with a metering bar. In that sample,
A 30 cm × 30 cm square is visually observed, and a portion where the coating film is not formed (coating loss) is counted as coating unevenness. X or more was evaluated as unacceptable, and x was judged as rejected.

(2) Foreign matter The thermoplastic resin A cut into a size of 30 cm × 30 cm in a dark room was irradiated with white light (18 W fluorescent lamp), and defects which could be visually confirmed by a transmission method and a reflection method were defined as foreign matter. Sample 1
Regarding the number of foreign substances per sheet, 0 was evaluated as ◎, 1 was evaluated as ○, 2 to 4 as Δ, and 5 or more as x, and x was judged as unacceptable.

(3) Retardation (Rd) Using a sodium D line (589 nm) as a light source, place the sample film surface perpendicular to the optical axis on a polarizing microscope equipped with orthogonal Nicols, and retardation caused by birefringence of the sample. Rd was determined from the compensation value of the compensator.

(4) Absolute value of surface potential Digital electrostatic potential measuring device (KSD-010 manufactured by Kasuga Electric)
Using 2), the surface potential of the thermoplastic resin A immediately after the removal of the thermoplastic resin B was measured. The distance between the film and the measuring instrument was 100 mm. The measurement was performed at 10 points, the average value was calculated, and the absolute value was obtained.

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

(6) Intrinsic viscosity: [η] The value calculated from the following formula based on the melt viscosity measured in orthochlorophenol at 25 ° C. was used. The solution viscosity and the solvent viscosity were measured with an Ostwald viscometer. ηsp / C = [η] + 2K [η] C where ηsp = (solution viscosity / solvent viscosity) −1 C: weight of dissolved polymer per 100 ml of solvent (g / 1
K: Haggin's constant (0.343) (7) Glass transition point As a differential scanning calorimeter, DS manufactured by Seiko Instruments Inc.
C (RDC220), using a disk station (SSC / 5200) made by the company as a data analysis device, holding about 5 mg of the sample in an aluminum pan at 300 ° C. for 5 minutes, quenching with liquid nitrogen, and then increasing the temperature. 20 ° C /
It was measured in min.

(8) Light Transmittance The total light transmittance for a thickness of 3 mm was measured according to ASTM-D1003.

(9) Melt Specific Resistance A voltage was applied from a DC high voltage generator between the electrodes inserted into the resin melt, and the current value at this time was measured and calculated according to the following equation. p = V × S (I × D) Here, p: melting specific resistance (Ω · cm) V: applied voltage (V) S: electrode area (cm ² ) I: measured current (A) D: distance between electrodes (Cm).

[0053]

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 having a glass transition point of 170 ° C., a light transmittance of 92%, and a melting specific resistance of 2 × 10 ¹⁰ Ω · cm (“Zeonor” manufactured by Zeon Corporation) After vacuum drying at 120 ° C. for 2 hours, the mixture is supplied to an extruder A and melted at 280 ° C. On the other hand, polyethylene terephthalate (homopolymer of ethylene terephthalate, intrinsic viscosity 0.7 dl / g) having a melting specific resistance of 2 × 10 ⁶ Ω · cm was used as the thermoplastic resin B, dried under vacuum at 180 ° C. for 2 hours, and charged. After adding 1% of Bontron N-01 manufactured by Orient Chemical Co. as a control agent and uniformly mixing with a blender, the mixture is supplied to an extruder A, melted at 280 ° C., and mixed with a thermoplastic resin A supplied from an extruder A. Was laminated in an adapter, and then discharged from a die. The discharged molten sheet is applied to the chromium plating roll maintained at 40 ° C. by an electrostatic application casting method at an applied voltage of 15 kV and solidified by cooling, and a laminated film having a laminated thickness ratio B / A / B = 50/400/50 μm. I got Peel thermoplastic resin B (peeling force 10g)
/ Cm) has a surface potential of 0.1 kV.
Met. Table 1 shows the properties of the thermoplastic resin A. The film had small Rd and coating unevenness, little foreign matter, and had excellent characteristics.

Example 2 As a charge control agent, Bontron S- manufactured by Orient Chemical Co., Ltd.
A film was obtained in the same manner as in Example 1, except that 0.5% of 34 was added and the surface potential was changed to 0.3 kV. Table 1 shows the properties of the obtained thermoplastic resin A. The film is R
d, coating unevenness was small, foreign matters were small, and excellent characteristics were obtained.

Example 3 The lamination ratio (thermoplastic resin B / thermoplastic resin A / thermoplastic resin B) was 1/400/1 μm, and the surface potential was 0.4 k.
A film was obtained in the same manner as in Example 1 except that V was set.
Table 1 shows the properties of the obtained thermoplastic resin A. The film had small Rd and coating unevenness, little foreign matter, and had excellent characteristics.

Example 4 As the thermoplastic resin A, an alicyclic polyolefin having a glass transition point of 150 ° C., a light transmittance of 92%, and a melting specific resistance of 2 × 10 ¹⁰ Ω · cm (“Apel” manufactured by Mitsui Chemicals, Inc.) Using
After vacuum drying at 120 ° C for 2 hours,
Melt at 80 ° C. On the other hand, as the thermoplastic resin B, polyethylene terephthalate (homopolymer of ethylene terephthalate, intrinsic viscosity 0.7 dl / g) having a melting specific resistance of 2 × 10 ⁶ Ω · cm was used, and dried under vacuum at 180 ° C. for 2 hours. After adding 0.001% of Bontron N-01 manufactured by Orient Chemical Co. as a control agent and uniformly mixing with a blender, the mixture is supplied to an extruder a and melted at 280 ° C., and a thermoplastic resin supplied from an extruder a After A and A were laminated in an adapter in three layers, they were discharged from a die. The discharged molten sheet was brought into close contact with a chrome plating roll kept at 130 ° C. by a touch roll method, cooled and solidified, and a lamination thickness ratio B /
A laminated film of A / B = 50/400/50 μm was obtained. Table 1 shows the properties of the film made of the thermoplastic resin A obtained by peeling off the thermoplastic resin B. The film is
Rd, coating unevenness was small, foreign matters were small, and excellent characteristics were obtained.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the charge control agent was not added to the thermoplastic resin B and the surface potential of the thermoplastic resin A was 3 kV. Rate 9
An alicyclic polyolefin having a melting specific resistance of 2 × 10 ¹⁰ Ω · cm (“ZEONOR” manufactured by Zeon Corporation) was used.
After vacuum drying for 2 hours at 20 ° C.,
It was melted at 0 ° C. and discharged from a die. The discharged molten sheet was brought into close contact with a chromium plating roll kept at 150 ° C. by a touch roll method and cooled and solidified. Thereafter, the thermoplastic resin B was peeled off to obtain a thermoplastic resin A film having a thickness of 400 μm. Table 1 shows the properties of the obtained film.
d was large, and coating unevenness and foreign matter evaluation were poor.

[0059]

[Table 1]

[0060]

According to the laminated film and the film of the present invention, since there are no surface defects such as coating unevenness and foreign matter and the optical characteristics are excellent, it can be suitably used as a film for a liquid crystal display device.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F100 AH03A AH03C AK01A AK01B AK01C AK03B AK42A AK42C AK43B AK45B AK54B AK55B BA03 BA06 CA22A CA22C EH23 GB41 JA20A JA20C JG03 JG04 JG00 JG04 JB04 JG04

Claims (7)

[Claims] 1. A non-oriented film laminated on both surfaces of a thermoplastic resin A having a melting specific resistance of 1 × 10 ⁹ Ω · cm or more in such a manner that the thermoplastic resin B can be peeled off. After that, the absolute value of the surface potential of the thermoplastic resin A is 1 k
V or less. 2. The thermoplastic resin B contains 0.05% of a charge control agent.
The laminated film according to claim 1, wherein the content of the laminated film is from 20 to 20% by weight. 3. The thermoplastic resin B has a melting specific resistance of 5 × 10
The laminated film according to claim 1, wherein the thickness is less than ⁷ Ω · cm. 4. The laminated film according to claim 1, wherein the thermoplastic resin A is any of alicyclic polyolefin, polyarylate, polycarbonate, polyether sulfone, and polysulfone. 5. The laminated film according to claim 1, wherein the thermoplastic resin B is polyethylene terephthalate. 6. The laminated film according to claim 1, wherein the thickness of the thermoplastic resin B is 1 μm or more. 7. A film obtained by peeling a layer comprising the thermoplastic resin B from the laminated film according to claim 1.