JP2003329834A - Method for manufacturing molded product with molecular orientation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a molded product with molecular orientation and an optical retardation plate of which the light ray transmittance is hardly lowered even when a magnetic field is applied for the purpose of adjusting a birefringence value as required for the optical retardation plate or the like and further to provide a method for manufacturing long film for obtaining a polarizing plate without polarization unevenness and a method for manufacturing the polarizing plate. <P>SOLUTION: A film in a molten state is extruded by extrusion molding a cycloolefinic resin or an aromatic nucleus hydrogenated vinyl polymer resin. Subsequently 6 tesla magnetic field is applied to the extruded film, which in turn is cooled in this state and the optical retardation plate is obtained. The polarizing plate is obtained by laminating the optical retardation plate to a linearly polarizing film. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a molecularly oriented molded article, a retardation plate or a polarizing plate, and more specifically to a molecularly oriented molded article having desired birefringence and high light transmittance. , A long film, a retardation plate or a polarizing plate.

[0002]

2. Description of the Related Art Conventionally, various retardation plates have been used for the purpose of optically compensating for the birefringence effect of liquid crystal display elements. The retardation plate may be made of an inorganic crystal material or a plastic material. Plastic materials have the advantage of being able to continuously mass-produce large-area retardation plates having various optical anisotropies, as compared with inorganic crystal materials, and have been widely used in practice. The main plastic materials used as the retardation plate include a polycarbonate resin, a polymethylmethacrylate resin, a polyvinyl alcohol resin, a cellulose polymer, a norbornene polymer, and the like. As a method for producing these retardation plates made of a plastic material, a film-like molded product obtained by a melt extrusion molding method or a solvent casting method is mechanically stretched by equipment such as a roll or a tenter to unidirectionally move molecules. A general method is to orient it.

Further, for the purpose of stabilizing and improving optical characteristics such as thickness accuracy, retardation, wavelength dispersion, three-dimensionality and temperature characteristics of the retardation plate, the material is specified by stretching processing conditions or polymer alloy or the like. Addition of solvent is being studied. On the other hand, JP-A-63-775037, JP-A-1-71710, and JP-A-3-122128 disclose a method of applying a magnetic field to a liquid crystalline polymer to orient the polymer. There is. In addition, JP-A-7-62
Japanese Patent No. 121 discloses a method in which a polyacetylene derivative film is immersed in a solvent such as ethyl acetate to apply a magnetic field to orient the film. Further, Japanese Patent Application Laid-Open No. 2001-51115 proposes a method for producing a retardation plate, which is characterized by applying a magnetic field to a polyethylene terephthalate resin to orient the molecules in an arbitrary direction. However, according to these proposals, when a magnetic field is applied to the resin, the light transmittance is extremely reduced. In order to keep the light transmittance high, it is necessary to weaken the application of the magnetic field, and as a result, the birefringence value is not sufficiently large, and the thickness must be large to obtain a desired retardation plate.

[0004]

DISCLOSURE OF THE INVENTION The object of the present invention is to provide a molecularly oriented molded article in which the light transmittance hardly decreases even when a magnetic field is applied so as to obtain a birefringence value required for a retardation plate or the like. , To provide a manufacturing method of a retardation plate. Another object of the present invention is to provide a method for producing a long film and a polarizing plate for obtaining a polarizing plate without uneven polarization. The present inventor, as a result of intensive studies to achieve the above object, by applying a magnetic field to the cycloolefin resin or the nuclear hydrogenated aromatic vinyl polymer resin, the light transmittance hardly decreases, the molecule It was found that an oriented molded product or a retardation film can be obtained, and a resin is extruded and a magnetic field is applied to the extruded product to obtain a long film or a retardation film, which is laminated with a linear polarizing film. It was found that a polarizing plate effective for a liquid crystal display device can be obtained by doing so, and the present invention has been completed based on this finding.

[0005]

Thus, according to the present invention, a process for producing a molecularly oriented molded product having a step of applying a magnetic field to a cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin, and a cycloolefin There is provided a method for producing a molecularly oriented molded product, in which a resin-based resin or a nuclear hydrogenated aromatic vinyl-based polymer resin is heated and melted, and a magnetic field is applied, followed by cooling and solidification in that state. According to the present invention, a method for producing a retardation plate having a step of applying a magnetic field to a cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin, and a cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin There is provided a method for producing a retardation plate in which a material is heated and melted, a magnetic field is applied, and the material is cooled and solidified in that state. Further, according to the present invention, a resin is extrusion-molded, a magnetic field is applied to an extruded product in a heating and melting state, a method for producing a molecularly oriented long film in which cooling and solidification is performed in that state, and obliquely with respect to the longitudinal direction. There is provided a method of making the elongated film that applies a magnetic field. Further, according to the present invention, a transparent resin is extruded, a magnetic field is applied to an extruded product in a heating and melting state, and in this state, it is cooled and solidified to obtain a retardation plate, and this retardation plate is used as a linear polarizing film. When laminated, the crossing angle between the light transmission axis of the linear polarizing film and the slow axis of the retardation plate is 5 to
There is provided a method of obtaining a polarizing plate by laminating so as to have an angle of 50 degrees.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a molecularly oriented molded product and a retardation plate of the present invention is characterized by including a step of applying a magnetic field to a cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin. And

The cycloolefin resin used in the present invention is a resin obtained by polymerizing or copolymerizing a cyclic olefin.
The cyclic olefin, norbornene, dicyclopentadiene, tetracyclododecene, ethyl tetracyclododecene, ethylidene tetracyclododecene, tetracyclo ^{[7.4.0.1 10,13.} Unsaturated hydrocarbons having a polycyclic structure such as 0 ^2,7 ] trideca-2,4,6,11-tetraene and derivatives thereof; cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene, cyclooctene, 3a,
5,6,7a-Tetrahydro-4,7-methano-1H-
Examples include monocyclic unsaturated hydrocarbons such as indene, cycloheptene, cyclopentadiene, and cyclohexadiene, and their derivatives. These cyclic olefins may have a polar group as a substituent. As the polar group, a hydroxyl group, a carboxyl group, an alkoxyl group, an epoxy group, a glycidyl group, an oxycarbonyl group,
Examples thereof include a carbonyl group, an amino group, an ester group, and a carboxylic acid anhydride group. Particularly, an ester group, a carboxyl group, or a carboxylic acid anhydride group is preferable.

The cycloolefin resin may be one obtained by addition-copolymerizing a monomer other than the cyclic olefin.
Examples of the addition-copolymerizable monomer include ethylene, propylene, 1-butene, 1-pentene, and the like, or α.
-Olefin; 1,4-hexadiene, 4-methyl-
Examples include dienes such as 1,4-hexadiene, 5-methyl-1,4-hexadiene, and 1,7-octadiene.

The cyclic olefin is obtained by an addition polymerization reaction or a metathesis ring-opening polymerization reaction. The polymerization is carried out in the presence of a catalyst. As the addition polymerization catalyst, for example,
Examples thereof include a polymerization catalyst composed of a vanadium compound and an organoaluminum compound. As a ring-opening polymerization catalyst, a polymerization catalyst comprising a metal halide such as ruthenium, rhodium, palladium, osmium, iridium or platinum, a nitrate or an acetylacetone compound, and a reducing agent;
Alternatively, a polymerization catalyst composed of a halide of a metal such as titanium, vanadium, zirconium, tungsten, molybdenum or an acetylacetone compound and an organoaluminum compound may be used. The polymerization temperature, pressure and the like are not particularly limited, but the polymerization is usually performed at a polymerization temperature of −50 ° C. to 100 ° C. and a polymerization pressure of 0 to 50 kgf / cm ² .

The cycloolefin resin used in the present invention is preferably a resin in which a cyclic olefin is polymerized or copolymerized and then hydrogenated to convert an unsaturated bond in the molecule into a saturated bond. The hydrogenation reaction is carried out by blowing hydrogen in the presence of a known hydrogenation catalyst. As the hydrogenation catalyst, cobalt acetate / triethylaluminum,
Nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium,
Homogeneous catalyst composed of a combination of transition metal compounds / alkyl metal compounds such as zirconocene dichloride / sec-butyl lithium, tetrabutoxy titanate / dimethyl magnesium; heterogeneous metal catalysts such as nickel, palladium, platinum; nickel / silica, nickel / Diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, palladium /
Examples include heterogeneous solid supported catalysts in which a metal catalyst such as alumina is supported on a carrier.

The cycloolefin resin used in the present invention is not particularly limited by its molecular weight, glass transition temperature and the like, but from the viewpoint of moldability, the weight average molecular weight is preferably 1,000 to 600,000, particularly preferably. It is 5,000 to 400,000.

The nuclear hydrogenated aromatic vinyl polymer resin used in the present invention is obtained by hydrogenating an aromatic vinyl polymer resin to change an aromatic ring into an alicyclic ring. The aromatic vinyl polymer resin is obtained by addition polymerization of an aromatic vinyl monomer or addition copolymerization of an aromatic vinyl monomer and another monomer. The addition polymerization reaction can be carried out according to a known method, for example, addition polymerization can be carried out by a solution polymerization method using a living anion polymerization catalyst.
Examples of the aromatic vinyl monomer include styrene, 2-methylstyrene, 4-phenylstyrene and the like. The monomer capable of addition copolymerization with the aromatic vinyl monomer is not particularly limited. For example, conjugated diene monomers such as butadiene and isoprene; ethylenically unsaturated carboxylic acids such as acrylic acid and methacrylic acid; ethylenically unsaturated carboxylic acids such as methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Examples thereof include acid esters; ethylenically unsaturated carboxylic acid amides such as acrylamide and methacrylamide; ethylenically unsaturated nitriles such as acrylonitrile and methacrylonitrile.

The aromatic ring hydrogenation reaction for obtaining the nuclear hydrogenated aromatic vinyl polymer resin can be carried out according to a known method and is not particularly limited. For example, hydrogenation can be performed by the same method as the hydrogenation reaction method that can be performed when obtaining the cycloolefin resin.

The nuclear hydrogenated aromatic vinyl polymer resin used in the present invention is not particularly limited by its molecular weight, glass transition temperature and the like, but from the viewpoint of moldability, the weight average molecular weight is preferably 1,000 to 600. 1,000, particularly preferably 5,000 to 400,000.

The cycloolefin resin and the nuclear hydrogenated aromatic vinyl resin used in the present invention may be an amorphous resin, but a resin having crystallinity is preferable. In the case of an amorphous resin, the glass transition temperature of the resin is preferably 30 to 300 ° C., particularly preferably 50 to 300 ° C. from the viewpoint of heat resistance and the like. When it is a crystalline resin, its crystal size is 5 to 300 n.
It is preferably a crystal having a size of m, particularly 10 to 100 nm. The cycloolefin resin and the nuclear hydrogenated aromatic vinyl resin used in the present invention preferably have a melting point. The melting point is preferably 50 to 400 ° C, particularly preferably 100 to 400 ° C.

The cycloolefin resin or the nuclear hydrogenated aromatic vinyl resin used in the present invention may contain pigments, dyes, optical brighteners, dispersants, heat stabilizers, light stabilizers, as necessary.
An ultraviolet absorber, an antistatic agent, an antioxidant, a lubricant, a solvent and the like can be appropriately added.

The method of applying a magnetic field to the cycloolefin resin or the nuclear hydrogenated aromatic vinyl resin is not particularly limited. For example, a method of dissolving a cycloolefin-based resin or a nuclear hydrogenated aromatic vinyl-based resin in a solvent, applying a magnetic field to the solution, and evaporating and removing the solvent while applying the magnetic field, a cycloolefin-based resin or There is a method in which a nuclear hydrogenated aromatic vinyl-based resin is heated and melted, and then a magnetic field is applied, and the resin is cooled and solidified while the magnetic field is applied. In the present invention, the latter method, that is, the method of heating and melting the resin to apply a magnetic field is preferable.

The method for producing a molecularly oriented molded product or a retardation plate of the present invention is to melt a cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin by heating, and then apply a magnetic field to the resin, in that state. It is cooled and solidified.

The heating and melting temperature is not particularly limited as long as it is the temperature at which the resin melts. Specifically, it is heated to a temperature above its melting point or softening point. When a crystalline cycloolefin resin or a crystalline nuclear hydrogenated aromatic vinyl polymer resin is used, a molded product having a desired birefringence and a high light transmittance (specifically, a retardation plate In order to obtain), a temperature higher than the melting point of the cycloolefin-based resin or the nuclear hydrogenated aromatic vinyl-based polymer resin, preferably 5 to 40 ° C. higher than the melting point.
It is preferable to heat and melt at a high temperature, particularly preferably at a temperature 8 to 30 ° C. higher than the melting point.

After heating and melting, a magnetic field is applied. The stronger the strength of the applied magnetic field, the easier the molecular orientation. The strength of the magnetic field is preferably 1 Tesler or more, more preferably 2 Tesler or more, and particularly preferably 3 Tesler or more. The means for generating the magnetic field is not particularly limited, and examples thereof include an electromagnet and a permanent magnet. The application direction of the magnetic field is selected according to the function required of the retardation plate. For example, by applying a magnetic field in a direction parallel to the plate surface of the retardation plate, it can be oriented in the same direction as the retardation plate obtained by the conventional stretching method. When a magnetic field is applied in an oblique direction which is substantially parallel to the plate surface, a retardation plate having a phase difference in the oblique direction can be manufactured. It was difficult to manufacture a retardation plate having a retardation in an oblique direction by a conventional stretching method.

The method of cooling while applying a magnetic field is not particularly limited as long as it can bring the birefringence to 10 ⁻⁴ or more, but the temperature is lowered from the heating and melting temperature to obtain the melting point or softening point. It is preferable to maintain the temperature at a low temperature, preferably 5 to 80 ° C. below the melting point or softening point, particularly preferably 10 to 60 ° C. below the melting point or softening point for a while, and then cool to room temperature. The time for keeping the temperature is preferably 2 to 40 minutes, particularly preferably 3 to 25 minutes. It is preferable to apply a strong magnetic field while keeping the temperature from the viewpoint of easy molecular orientation. Another method for orienting molecules is a stretching method. However, in the stretching process, the force concentrates on a portion having insufficient strength in the molded product, and molecular cutting or the like partially occurs, so that the phase difference may vary. However, in the present invention, since the molecules are oriented by the magnetic force, a strong force for cutting the molecules is not applied, so that the variation in the phase difference hardly increases. The phase difference is represented by the product of the plate thickness and the birefringence value.
For example, in order to obtain a retardation plate having a retardation of a quarter wavelength of 570 nm, the product of birefringence and plate thickness is 142.5 nm.
In order to obtain a half-wave retardation plate, the product of birefringence and plate thickness is set to 285 nm. In order to function as a retardation plate, a magnetic field is applied so that the birefringence becomes 10 ⁻⁴ or more.

In the method for producing a retardation film of the present invention, the thickness of the obtained retardation plate is preferably 0.05 to 2.0 mm, particularly preferably 0.1 to 1 mm. In the conventional manufacturing method by the stretching method, it is necessary to form a retardation original plate thicker than the target sheet thickness in consideration of the reduction in the sheet thickness in the stretching step. In addition, if the formed original plate is not uniform, there are portions where the draw ratio is large and portions where the draw ratio is small, and variations in the draw ratio occur, resulting in uneven thickness after drawing. On the other hand, in the method of the present invention, the thickness before orientation can be maintained even if molecular orientation is performed, and thickness unevenness is less likely to occur. Therefore, the thickness of the retardation plate to which a magnetic field is applied is the same as the thickness of the retardation plate to be obtained. Adjusted to the thickness.

The process for producing a molecularly oriented long film of the present invention is characterized by extruding a resin, applying a magnetic field to an extruded product in a heat-melted state, and cooling and solidifying in that state. A long film is used as a raw material for a retardation plate. The resin used in the method of producing the molecularly oriented long film of the present invention is not particularly limited, but a transparent (light transmittance of 80% or more) resin such as an acrylic resin or a polycarbonate resin is preferable, and a cycloolefin resin and a nuclear water are used. An added aromatic vinyl resin is particularly preferable. The extrusion molding of the resin can be performed according to a known method. That is, the resin is heated and melted, and is passed through the gate portion to be molded using an extruder. The magnetic field is applied to the molded product in a molten state immediately after being extruded from the extruder, or the extruded product is heated by a roll or the like to be in a remelted state. The magnetic field application method and the temperature during application of the magnetic field are the same as those described above. The magnetic field can be applied parallel to the longitudinal direction, at a right angle or obliquely. When a magnetic field is applied substantially parallel to the film surface and obliquely in the longitudinal direction, the molecular orientation becomes oblique, and as a result, a long film (that is, a long retardation plate) in which the slow axis becomes oblique is obtained. The thickness of the film is preferably 0.05-2.
It is set to 0 mm, particularly preferably 0.1 to 1 mm.

In the method for producing a polarizing plate of the present invention, a transparent resin is extrusion-molded, a magnetic field is applied to an extruded product in a heated and molten state, and in that state, it is cooled and solidified to obtain a retardation plate. It is characterized in that it is laminated with a linear polarizing film so that the crossing angle between the light transmission axis of the linear polarizing film and the slow axis of the retardation plate is 5 to 50 degrees. The retardation plate in which the molecules are obliquely oriented can be obtained by the above-described method for producing a long film.

The linear polarizing film used in the method for producing the polarizing plate of the present invention includes iodine polarizing film; dye polarizing film using dichroic dye; polyene polarizing film. The iodine type polarizing film and the dye type polarizing film are generally manufactured using a polyvinyl alcohol type film. Polyvinyl alcohol is produced by saponification of polyvinyl acetate. A modified polyvinyl alcohol obtained by saponifying a copolymer of vinyl acetate and another ethylenically unsaturated monomer (eg, unsaturated carboxylic acid, unsaturated sulfonic acid, olefin, vinyl ether) may be used. Modified polyvinyl alcohol may be produced by introducing other functional group (eg, acetoacetyl, sulfo, carboxyl, alkoxy group) into polyvinyl alcohol. The saponification degree of polyvinyl alcohol is 80
˜100 mol%, more preferably 90-100 mol%. The polymerization degree of polyvinyl alcohol is preferably 1000 to 10000, and more preferably 1500 to 5000.

The polyvinyl alcohol film is a solution prepared by dissolving polyvinyl alcohol in water or an organic solvent,
It is obtained by casting and film formation. As the organic solvent used for forming the polyvinyl alcohol film, alcohol (eg,
Methanol, ethanol, propanol, butanol), polyhydric alcohol (eg, glycerin, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylolpropane), amine (eg, ethylenediamine, diethylenetriamine), dimethyl sulfoxide, Mention may be made of N-methylpyrrolidone and mixtures thereof.

The transmission axis of the long linear polarizing film may be parallel, perpendicular or oblique to the longitudinal direction. The long film in which the molecules are obliquely oriented is
The slow axis is slanted. When the inclination of the transmission axis of the long linear polarizing film with respect to the longitudinal direction is different from the inclination of the slow axis of the long film with respect to the longitudinal direction, the long linear polarizing film and the long film are stacked and wound by a roll to be laminated. Only by doing so, it is possible to manufacture a laminated body having a constant crossing angle between the slow axis and the transmission axis.

The long linear polarizing film can be produced by stretching a long polyvinyl alcohol film in the longitudinal direction, the width direction or the oblique direction, and then adsorbing iodine or a dichroic dye to the polyvinyl alcohol film. . The long linear polarizing film can also be produced by rubbing a long polyvinyl alcohol film in the longitudinal direction, the width direction or the oblique direction, and then adsorbing iodine or a dichroic dye to the polyvinyl alcohol film. Further, the long linear polarizing film can also be produced by providing a long polyvinyl alcohol film with a coating layer containing iodine or a dichroic dye, and then rubbing the film in a longitudinal direction, a width direction or an oblique direction. . A magnetic field is applied to the long polyvinyl alcohol film in the longitudinal direction, the width direction or the oblique direction similarly to the method used for obtaining the long film, and then iodine or a dichroic dye is adsorbed to the polyvinyl alcohol film. It can be manufactured.

The method for stretching the polyvinyl alcohol film is not particularly limited, and known stretching techniques can be applied.
The draw ratio is preferably 2.5 to 30 times, and 3
It is more preferably from 10 times. Stretching can be performed as dry stretching in air. In the case of dry stretching, the stretching ratio is preferably 2.5 to 5 times. Stretching
It can also be carried out as wet stretching by immersing in water. In the case of wet stretching, the stretching ratio is preferably 3 to 10 times.

In the rubbing treatment, the surface of the polyvinyl alcohol film is treated with paper or cloth (for example, gauze, felt,
Rub in one direction with a rubber cloth, nylon cloth, or polyester cloth. The fibers of the paper or cloth are preferably uniform in length and thickness. Further, it is preferable that the paper or cloth contains fibers uniformly. The rubbing process is usually several times,
Carry out in the same direction. It is preferable to perform the rubbing treatment using a rubbing roll. The circularity, cylindricity, and runout (eccentricity) of the rubbing roll are all preferably 30 μm or less. The wrap angle of the film on the rubbing roll is preferably 0.1 to 90 degrees. However, there is also a method (described in Japanese Patent Application Laid-Open No. 8-160430) in which a rubbing roll is wound with a film at 360 degrees or more and a stable rubbing treatment is carried out. The rolled film is preferably subjected to the rubbing treatment while being kept at a constant tension on the film by using a conveying device and being conveyed at a speed of 1 to 10 m / min. In order to perform the rubbing treatment in the direction of 45 degrees with respect to the longitudinal direction, it is preferable to use a rubbing roll which is rotatable in the horizontal direction with respect to the traveling direction of the film.

The dyeing step can be carried out by a gas phase or liquid phase adsorption treatment. In the liquid phase adsorption treatment of iodine, iodine
The polyvinyl alcohol film is immersed in an aqueous potassium iodide solution. The iodine concentration is preferably 0.1 to 2 g / liter, the potassium iodide concentration is preferably 10 to 50 g / liter, and the potassium iodide / iodine weight ratio is 20.
It is preferably ˜100. Immersion time is 30-5
It is preferably 000 seconds and the temperature of the aqueous solution is 5 to 50.
C. is preferred. In the dyeing process, besides dipping,
It can also be carried out by applying or spraying an iodine solution or a dye solution. As the dichroic dye, azo dye, stilbene dye, quinone dye, anthraquinone dye, azomethine dye, methine dye (eg, cyanine dye, merocyanine dye), quinophthalone dye or tetrazine dye can be used. Azo dyes and anthraquinone dyes are preferred.

The dyed polyvinyl alcohol film is generally subjected to a crosslinking treatment. A boron compound or an aldehyde is used for the crosslinking treatment. It is particularly preferable to use a boron compound. Examples of boron compounds include boric acid and borax. The boron compound is used as a solution. The solvent of the solution is preferably water or a mixed solvent of water and an organic solvent. The solution concentration is 0.5 to 2 mol /
L is preferred. The crosslinking treatment can be carried out by immersing the dyed polyvinyl alcohol film in a borax compound solution, or by spraying or applying the solution to the film. It is preferable to add a small amount of potassium iodide to the boron compound solution. Immersion temperature is 40-70
The temperature is preferably ° C, and the immersion time is preferably 5 to 20 minutes. The oblique stretching treatment may be carried out simultaneously with the crosslinking treatment.

The polyvinyl alcohol film may be heat-treated. The moisture content of the film during the heat treatment is 10 to
It is preferably 30% by weight. Heat treatment temperature is 40 ~
The temperature is preferably 100 ° C, more preferably 50 to 90 ° C. The heat treatment time is preferably 30 seconds to 15 minutes.

A transparent protective film is preferably provided on the opposite surface of the linear polarizing film laminated with the long film (that is, the retardation film). The transparent protective film is transparent (with a light transmittance of 80
% Of resin) is preferred. As the transparent resin suitable for the transparent protective film, cycloolefin resin, polyolefin, cellulose acetate, polycarbonate, polyarylate, polysulfone or polyether sulfone can be used. A commercially available transparent resin or transparent resin film may be used.

The linear polarizing film and the retardation film or the linear polarizing film and the transparent protective film are attached to each other with an adhesive. As the adhesive, a polyvinyl alcohol-based resin or an aqueous solution of a boron compound is preferable, and a polyvinyl alcohol-based resin is particularly preferable. As the polyvinyl alcohol-based resin, a modified polyvinyl alcohol into which a functional group other than alcohol (eg, acetoacetyl, sulfo, carboxyl, alkoxy group) is introduced may be used. The thickness of the adhesive is
It is preferably 0.01 to 10 μm after drying,
It is more preferably 0.05 to 5 μm. The linear polarizing film and the retardation plate are laminated so that the light transmission axis of the linear polarizing film and the slow axis of the retardation plate intersect at an angle of 5 to 50 degrees. The polarizing plate obtained by laminating in this way is a camera,
It is used for various purposes such as glasses. The polarizing plate obtained by the production method of the present invention is particularly effectively used for a liquid crystal display device.

[0036]

According to the method for producing a molecularly oriented molded article of the present invention, the light transmittance of the molded article can be 75% or more, and can be 85% or more if the conditions are adjusted. Here, the light transmittance means the total light transmittance of visible light having a wavelength of about 400 to 800 nm. The larger the light transmittance, the brighter the liquid crystal display screen is, which is preferable. According to the method for producing a retardation plate of the present invention, it is possible to efficiently produce a retardation plate having a high light transmittance and a desired birefringence. Further, according to the method for producing a long film or a polarizing plate of the present invention, a polarizing plate having no polarization unevenness, which is effective for a liquid crystal display device or the like, can be obtained by laminating a retardation plate with a linear polarizing film.

[0037]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples. In addition, "part" is "part by weight" unless otherwise specified. The retardation and birefringence evaluated in Examples and Comparative Examples are the wavelength 5 measured by a polarimeter made by Shinko Seiki.
The value is 89 nm. Total light transmittance is JIS K71
It is a value measured using an integrating sphere type light transmittance measuring device in accordance with 05.

Production Example 1 In a glass reactor equipped with a stirrer, the general formula (1)

[0039]

[Chemical 1]

The molybdenum compound represented by 0.006
After adding 8 parts, 24 parts of cyclohexane, 6 parts of dicyclopentadiene, and 0.00573 parts of 1-hexene were added, and a polymerization reaction was carried out at room temperature. A white precipitate was deposited immediately after the initiation of the polymerization reaction. After reacting for 3 hours, the polymerization reaction solution was poured into a large amount of isopropanol to completely precipitate the polymer, which was washed by filtration and dried under reduced pressure at 40 ° C. for 40 hours. The yield of the obtained ring-opening polymer was 5.5 parts, and the molecular weight (in terms of polystyrene) was number average molecular weight (Mn) = 37,000.
0 and the weight average molecular weight (Mw) were 103,000. The melting point was 218 ° C.

5 parts of the obtained ring-opening polymer and 88 parts of cyclohexane were added to an autoclave equipped with a stirrer. Then, a hydrogenation catalyst solution prepared by dissolving 0.031 parts of bis (tricyclohexylphosphine) benzilidineruthenium (IV) dichloride and 1.8 parts of ethyl vinyl ether in 18 parts of cyclohexane was added, and the hydrogen pressure was 8 kg / cm ² , 1
The hydrogenation reaction was carried out at 20 ° C. for 10 hours. The hydrogenation reaction liquid was poured into a large amount of isopropanol to completely precipitate the polymer, which was washed by filtration and dried under reduced pressure at 40 ° C. for 40 hours. In the infrared absorption spectrum, absorption derived from carbon-carbon double bond was not observed, and the hydrogenation rate was 99% or more. The melting point of the obtained hydride was 272 ° C. On 100 parts of the hydride, pentaerythrityl-tetrakis (3- (3,5-
Di-tertiary-butyl-4-hydroxyphenyl) propionate) was added in an amount of 0.2 part, and a twin-screw extruder was used.
The resin was melt-kneaded at an average temperature of 320 ° C. and pelletized by a pelletizer to obtain a molding material.

Production Example 2 A ring-opened polymer was obtained by polymerizing in the same manner as in Production Example 1 except that the dicyclopentadiene used in Production Example 1 was changed to norbornene. Mn of this ring-opening polymer was 50,100,
The Mw was 116,400. The melting point was 115 ° C. This ring-opened polymer was hydrogenated in the same manner as in Production Example 1 to obtain a hydrogenated product with a melting point of 160 ° C. The hydride 10
0.2 parts of pentaerythrityl-tetrakis (3- (3,5-di-tertiary-butyl-4-hydroxyphenyl) propionate) as a hindered phenolic antioxidant was added to 0 parts, and the mixture was mixed with a twin-screw extruder. The resin was melt-kneaded at an average temperature of 220 ° C. and pelletized by a pelletizer to obtain a molding material.

Example 1 Pellets of the hydrogenated dicyclopentadiene ring-opening polymer obtained in Production Example 1 were dried at 150 ° C. and then fed to a T-die extruder to give a transparent non-coated sheet having a thickness of 0.1 mm. A stretched film was produced. This non-stretched film was placed in a magnetic field of 6 Tesla, heated from room temperature to 310 ° C. at a temperature of 5 ° C./minute to melt, and kept at 310 ° C. for 10 minutes. Then, it was cooled to 240 ° C. at 5 ° C./minute in the same magnetic field, kept at 240 ° C. for 5 minutes, and then cooled to room temperature to solidify. The magnetic field was applied parallel to the film surface in a direction at an angle of 45 degrees with respect to the longitudinal direction. The retardation plate having a thickness of 0.1 mm thus obtained had a retardation of 95 nm, a birefringence of 9.5 × 10 ⁻⁴ and a total light transmittance of 87%.

Example 2 A retardation plate was obtained in the same manner as in Example 1 except that the holding time at 240 ° C. was changed to 15 minutes. The retardation plate having a thickness of 0.1 mm thus obtained had a retardation of 240 nm, a birefringence of 2.4 × 10 ⁻³ and a total light transmittance of 84%.

Example 3 Pellets of the hydrogenated product of the norbornene ring-opening polymer obtained in Production Example 2 were dried at 80 ° C. and then fed to a T-die extruder to give a transparent unstretched film having a thickness of 0.1 mm. Was manufactured. This unstretched film is placed in a magnetic field of 6 Tesla and heated from room temperature to 160 ° C. at 5 ° C./minute to melt,
Hold at 10 ° C for 10 minutes. Then, it was cooled to 135 ° C. at 5 ° C./min in the same magnetic field, kept at 135 ° C. for 5 minutes, and then cooled to room temperature to solidify. The magnetic field is parallel to the film surface,
The voltage was applied at an angle of 45 degrees to the longitudinal direction. The retardation plate having a thickness of 0.1 mm thus obtained had a retardation of 430 nm, a birefringence of 4.3 × 10 ⁻³ and a total light transmittance of 80%.

Comparative Example 1 Dehumidified and dried polyethylene terephthalate (intrinsic viscosity =
The pellets (1.05, melting point = 253 ° C.) were supplied to a T-die extruder to produce a transparent unstretched film having a thickness of 0.1 mm. This unstretched film was heated to a temperature of 270 ° C. in a magnetic field of 6 Tesla and melted, and then 245 in the same magnetic field.
The mixture was cooled and solidified at 0 ° C. for 20 minutes. The magnetic field was applied in the longitudinal direction parallel to the film surface. The obtained retardation plate having a thickness of 0.1 mm has a phase difference of 35 nm and a birefringence of 3.5 × 10.
^-4 , the total light transmittance was 41%.

Comparative Example 2 Dehumidified and dried polyethylene terephthalate (intrinsic viscosity =
The pellets (1.05, melting point = 253 ° C.) were supplied to a T-die extruder to produce a transparent unstretched film having a thickness of 0.1 mm. This unstretched film was heated to a temperature of 260 ° C. in a magnetic field of 6 Tesla and melted, and then melted in the same magnetic field for 235
It was cooled and solidified at 0 ° C. for 3 minutes. The magnetic field was applied in the longitudinal direction parallel to the film surface. The obtained retardation plate having a thickness of 0.1 mm has a retardation of 23 nm and a birefringence of 2.3 × 1.
^0-4 , the total light transmittance was 70%.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H049 BA06 BA42 BB03 BB48 BC06                       BC22                 2H091 FA08 FA11 FB02 FC01 FC22                       FD10 LA12 LA16                 4F207 AA12 AB06 AG01 KA01 KA17                       KK13 KK66 KL84

Claims (7)

[Claims] 1. A process for producing a molecularly oriented molded product, which comprises a step of applying a magnetic field to a cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin. 2. A cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin is heated and melted, and a magnetic field is applied.
A method for producing a molecularly oriented molded product that is cooled and solidified in that state. 3. A method for producing a retardation plate, which comprises a step of applying a magnetic field to a cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin. 4. A cycloolefin resin or a nuclear hydrogenated aromatic vinyl polymer resin is heated and melted, and a magnetic field is applied,
A method of manufacturing a retardation plate that is cooled and solidified in that state. 5. A method for producing a molecularly oriented long film in which a resin is extrusion-molded, a magnetic field is applied to an extruded product in a heat-melted state, and the resin is cooled and solidified in that state. 6. The method for producing a long film according to claim 5, wherein the magnetic field is applied obliquely with respect to the longitudinal direction of the long film. 7. A transparent resin is extruded, a magnetic field is applied to an extruded product in a heated and melted state, and in that state, it is cooled and solidified to obtain a retardation plate. The retardation plate is laminated with a linear polarizing film, A method of obtaining a polarizing plate by laminating the linearly polarizing film so that the crossing angle of the light transmission axis of the linearly polarizing film and the slow axis of the retardation plate is 5 to 50 degrees.