JP2005025149A - Polarizing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate substantially free of optical distortion even when curved. <P>SOLUTION: The polarizing plate is obtained by sticking a transparent sheet and a polarizing film together, wherein the transparent sheet comprises a polycarbonate resin composition obtained by blending a polycarbonate resin (A) prepared by bringing 95-5 mol% of a dihydroxy compound represented by formula (1) (where R<SB>1</SB>and R<SB>2</SB>each represents H or methyl) and 5-95 mol% of a dihydroxy compound represented by formula (2) (where X represents a 1-10C alkylene or 4-20C cycloalkylene) into carbonate bonding with a carbonic diester and a polycarbonate (B) prepared by bringing a dihydroxy compound represented by formula (3) into carbonate bonding with a carbonic diester or phosgene in a ratio satisfying [100×(A)]/[(A)+(B)]=1-99 wt.%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polarizing plate formed by laminating a polarizing film and a transparent sheet made of a polycarbonate resin derived from a specific dihydroxy compound.

  Since a polarizing plate exhibits excellent anti-glare properties, it is widely used in the field of optical materials that require anti-glare properties such as sunglasses and goggles. The polarizing plate is formed by laminating a transparent sheet on one side or both sides of a polarizer. As the polarizer, for example, a polarizing film in which iodine or a dichroic dye is adsorbed on a polymer film typified by a film made of polyvinyl alcohol or a derivative thereof and the film is stretched and oriented uniaxially is used. As the transparent sheet, a cellulose sheet, an acrylic sheet, a polycarbonate sheet, or the like is used, and among them, a polycarbonate sheet is widely used in fields where impact resistance and heat resistance are required. In addition, the polycarbonate here is generally a polycarbonate resin made of 2,2-bis (4-hydroxyphenyl) propane (common name: bisphenol A) which is inexpensive and easily available.

Such a polycarbonate resin comprising bisphenol A has excellent transparency, impact resistance, heat resistance, low water absorption, solvent resistance, mechanical properties, and dimensional stability, and thus a CD or DVD substrate, optical film, optical sheet, It is widely used for optical materials such as various lenses or prisms. However, the polycarbonate resin made of bisphenol A has the disadvantage that the birefringence and the photoelastic coefficient are large.

According to the study by the present inventors, a transparent film made of a polycarbonate resin made of bisphenol A is bonded to both surfaces of a polarizing film to form a polarizing plate, and the polarizing plate is vacuum-formed, pressure-formed, or press-formed into a curved shape. In this case, it has been found that the stress distortion of the curved surface portion causes an optical distortion and a significant adverse effect that the polarization is disturbed. When the curved shaped body having such optical distortion is viewed obliquely, iridescent color unevenness is observed. Further, when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are orthogonal to each other, so-called color loss or colored interference fringes through which light is transmitted is observed. In addition, when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are parallel to each other, coloring different from the polarizing film color or colored interference fringes is observed on a part of the polarizing plate. The

For example, at least Li terpolymers retardation value to one surface of the polarizing film Definitions: birefringence (△ n) × thickness (d)] is laminated to a polycarbonate resin sheet of 3000～6000Nm, spectacle lens shaped polarizing performing curved surface machining There exists description regarding a board (for example, patent document 1). According to this patent document, a polycarbonate resin sheet made of bisphenol A having a retardation value of 3000 nm or more is adhered to both surfaces of a polarizing film to form a polarizing plate, cut into a circular shape, and then processed into a convex lens shape by pressure forming, It is described that even when the obtained convex lens-shaped polarizing plate was observed from an oblique direction, color unevenness was not observed at all. This method can be said to be an effective method is also used for actual production, on a required orientation treatment by stretching in order to ensure the re-coater retardation value of PC sheet, the axial polarizing substrate and the alignment axis There is a problem in workability. In addition, the sheet has a defect such as shrinkage when heated during the secondary processing.

For example, there is described a polarizing plate on one side or re terpolymer retardation value on both sides is not less 300nm or less and a thickness, which are attached the polycarbonate resin sheet of 0.05~0.25mm polarizing film (e.g., Patent Documents 2). In this patent document, after producing a transparent protective sheet made of polycarbonate resin made of bisphenol A by a casting method, the transparent protective sheet is bonded to both sides of a polarizing film to produce a polarizing plate, and the polarizing performance is examined. Yes. However, in this patent document, the polarizing performance when the curved surface processing is not performed is only examined for the polarizing plate having the transparent protective sheet made of polycarbonate resin made of bisphenol A. According to a study by the present inventors, the polarizing plate was cut into a circular shape and then curved into a convex lens shape by vacuum forming, and in the obtained polarizing plate, when viewed obliquely, iridescent color unevenness was observed. Observed. Furthermore, when the curved polarizing plate was observed with a flat polarizing plate arranged so that the polarization axes thereof were orthogonal to each other, so-called color loss or colored interference fringes through which light was transmitted were observed. In addition, when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are parallel to each other, coloring different from the polarizing film color or colored interference fringes is observed on a part of the polarizing plate. It was. This indicates that the optical performance of the product is still insufficient when the curved surface is processed .

After processing the curved surface , optical distortion occurs, that is , when viewed from an oblique direction, iridescent color unevenness is observed, or the plane polarized light in which the curved polarizing plates are arranged so that their polarization axes are orthogonal to each other When observing over a plate, light is transmitted, so-called color loss or colored interference fringes are observed, or a flat polarizing plate in which the curved polarizing plates are arranged so that their polarization axes are parallel to each other When observed repeatedly, a part of the polarizing plate is observed to be colored different from the polarizing film or colored interference fringes are observed because the birefringence of the polycarbonate resin made of bisphenol A is large, that is, the intrinsic birefringence and orientation. This is because the distribution function or photoelastic coefficient is large. Therefore, various low birefringence resins have been tried as transparent protective sheets for polarizing films. However, for example, it is processed into a polarizing plate by using amorphous polyolefin which is a typical low birefringence resin to the protective sheet, when the curved surface processing a polarizing plate on a convex lens, not seen in the plane polarizer The present inventors have found that optical distortion occurs.
Japanese Patent Laid-Open No. 9-5683 JP 2001-305341 A

  An object of the present invention is to provide a polarizing plate in which optical distortion does not substantially occur even when a curved surface is processed. That is, it is to provide a polarizing plate in which a transparent sheet made of a specific low birefringence resin is bonded to a polarizing film.

  As a result of intensive studies to solve the above problems, the present inventors have found that the dihydroxy compound represented by the general formula (1) is 95 to 5 mol% and the dihydroxy compound represented by the general formula (2) 5 to 95. A polycarbonate resin (A) obtained by carbonate-bonding mol% with a carbonic acid diester, and a polycarbonate resin (B) obtained by carbonate-bonding a dihydroxy compound represented by the structural formula (3) with a carbonic acid diester or phosgene. × (A)) / ((A) + (B)) = 1 to 99% by weight A transparent sheet made of a polycarbonate resin composition obtained by blending at a ratio of 1 to 99% by weight and a polarizing film are bonded together. The inventors have found that the above problems can be solved by a polarizing plate, and have reached the present invention.

（式中、Ｒ₁、Ｒ₂は水素原子またはメチル基を表す。）

(In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group.)

（式中、Ｘは、炭素数１〜１０のアルキレン基または炭素数４〜２０シクロアルキレン基を表す。）

(In the formula, X represents an alkylene group having 1 to 10 carbon atoms or a cycloalkylene group having 4 to 20 carbon atoms.)

According to the present invention, it is possible to obtain an excellent polarizing plate that is excellent in optical characteristics, excellent in thermoformability, and hardly causes optical distortion even when curved processing is performed. By using the polarizing plate, an optical material such as polarized sunglasses or goggles having extremely excellent optical characteristics can be obtained, which is extremely useful.

  As the dihydroxy compound represented by the general formula (1) for deriving the polycarbonate resin (A) used in the present invention, specifically, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene and 9,9-bis (4- (2-hydroxyethoxy) -3,5-dimethylphenyl) fluorene are exemplified. Among these, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene is preferably used.

Specific examples of the dihydroxy compound represented by the general formula (2) for deriving the polycarbonate resin (A) used in the present invention include tricyclo [5.2.1.0 ^2,6 ] decanedimethanol, cyclohexane. Examples include -1,4-dimethanol, decalin-2,6-dimethanol, norbornane dimethanol, pentacyclopentadecane dimethanol, cyclopentane-1,3-dimethanol and the like. Among them, tricyclo [5.2.1.0 ^2,6 ] decanedimethanol and cyclohexane-1,4-dimethanol are preferable, and tricyclo [5.2.1.0 ^2,6 ] decanedimethanol is more preferable. preferable.

  The method for producing the polycarbonate resin (A) according to the present invention will be described below. A known melt polycondensation method in which a dihydroxy compound and a carbonic acid diester are reacted in the presence of a mixed catalyst comprising a basic compound catalyst or a transesterification catalyst or both is suitably used.

  Examples of the carbonic acid diester include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, and dicyclohexyl carbonate. Of these, diphenyl carbonate is particularly preferred. The carbonic acid diester is preferably used in a ratio of 0.97 to 1.20 mol, more preferably 0.99 to 1.10 mol, relative to a total of 1 mol of the dihydroxy compound.

  Examples of the basic compound catalyst include alkali metal compounds and / or alkaline earth metal compounds, nitrogen-containing compounds, and the like.

  Examples of such compounds include organic acid salts such as alkali metal and / or alkaline earth metal compounds, inorganic salts, oxides, hydroxides, hydrides or alkoxides, quaternary ammonium hydroxides and salts thereof, and amines. Etc. are preferably used, and these compounds can be used alone or in combination.

  Specific examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, potassium bicarbonate, cesium bicarbonate, lithium bicarbonate, sodium carbonate, potassium carbonate, carbonate Cesium, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenyl borohydride, sodium benzoate, potassium benzoate Cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenyl phosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium , 2 lithium salt, sodium salt of phenol, potassium salt, cesium salt, lithium salt or the like is used.

  Specific examples of the alkaline earth metal compound include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium carbonate, calcium carbonate. Strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, magnesium phenyl phosphate, and the like are used.

  Specific examples of nitrogen-containing compounds include alkyl, aryl, groups, etc. such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide. Secondary ammoniums such as triethylamine, dimethylbenzylamine and triphenylamine; secondary amines such as diethylamine and dibutylamine; primary amines such as propylamine and butylamine; 2-methylimidazole, 2; -Imidazoles such as phenylimidazole and benzimidazole; or ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, Tetrabutylammonium tetraphenylborate, basic or basic salts such as tetraphenyl ammonium tetraphenylborate, or the like is used.

  As the transesterification catalyst, zinc, tin, zirconium and lead salts are preferably used, and these can be used alone or in combination.

  Specific examples of the transesterification catalyst include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, and dibutyltin. Dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead (II) acetate, lead (IV) acetate and the like are used.

These catalysts are used in a ratio of 10 ⁻⁹ to 10 ⁻³ mol, preferably 10 ⁻⁷ to 10 ⁻⁴ mol, relative to a total of 1 mol of the dihydroxy compound.

  The melt polycondensation method according to the present invention is a method in which melt polycondensation is carried out using the above-mentioned raw materials and catalyst while removing by-products by a transesterification reaction under normal pressure or reduced pressure. The reaction is generally carried out in a multistage process of two or more stages.

  Specifically, the reaction at the first stage is allowed to react at a temperature of 120 to 260 ° C, preferably 180 to 240 ° C for 0.1 to 5 hours, preferably 0.5 to 3 hours. Next, the reaction temperature is raised while raising the degree of vacuum of the reaction system to react the dihydroxy compound and the carbonic acid diester. Finally, the reaction is carried out at a temperature of 200 to 350 ° C. under a reduced pressure of 1 mmHg or less for 0.3 to 10 hours. Perform a condensation reaction. Such a reaction may be carried out continuously or batchwise. The reaction apparatus used for carrying out the above reaction is equipped with paddle blades, lattice blades, glasses blades, etc. even with vertical types equipped with vertical stirring blades, Max blend stirring blades, helical ribbon stirring blades, etc. It may be a horizontal type or an extruder type equipped with a screw, and it is preferable to use a reaction apparatus in which these are appropriately combined in consideration of the viscosity of the polymer.

  In the polycarbonate resin according to the present invention, the catalyst is removed or deactivated after the polymerization reaction in order to maintain thermal stability and hydrolysis stability. In general, a method of deactivating a catalyst by adding a known acidic substance is preferably performed. Specific examples of these substances include esters such as butyl benzoate, aromatic sulfonic acids such as p-toluenesulfonic acid, and aromatic sulfonic acids such as butyl p-toluenesulfonate and hexyl p-toluenesulfonate. Esters, phosphoric acids such as phosphorous acid, phosphoric acid, phosphonic acid, triphenyl phosphite, monophenyl phosphite, diphenyl phosphite, monoethyl phosphite, diethyl phosphite, monobutyl phosphite, Phosphorous esters such as dibutyl phosphate, dioctyl phosphite, monooctyl phosphite, triphenyl phosphate, diphenyl phosphate, monophenyl phosphate, monoethyl phosphate, diethyl phosphate, dibutyl phosphate, phosphoric acid Phosphate esters such as dioctyl and monooctyl phosphate, diphenylphosphonic acid, dioctylphosphonic acid, dibutyl Phosphonic acids such as sulfonic acid, phosphonic acid esters such as diethyl phenylphosphonate, phosphines such as triphenylphosphine and bis (diphenylphosphino) ethane, boric acids such as boric acid and phenylboric acid, tetrabutyl dodecylbenzenesulfonate Aromatic sulfonates such as phosphonium salts, organic halides such as stearic acid chloride, benzoyl chloride and p-toluenesulfonic acid chloride, alkyl sulfuric acids such as dimethyl sulfate, and organic halides such as benzyl chloride are preferably used.

  After deactivation of the catalyst, a step of devolatilizing and removing low-boiling compounds in the polymer at a pressure of 0.1 to 1 mmHg and a temperature of 200 to 350 ° C. may be provided. For this purpose, paddle blades, lattice blades, glasses A horizontal apparatus provided with a stirring blade having excellent surface renewability such as a blade or a thin film evaporator is preferably used.

  Below, the manufacturing method of polycarbonate resin (B) in connection with this invention is described. The polycarbonate resin (B) is a homopolymer derived from 2,2-bis (4-hydroxyphenyl) propane (common name: bisphenol A) represented by the structural formula (3), but bisphenols other than bisphenol A are used. A small amount may be copolymerized within a range where physical properties are not impaired. As one of the methods for producing the polycarbonate resin (B), a known melt polycondensation method in which a dihydroxy compound and a carbonic acid diester are reacted in the presence of a basic compound catalyst is preferably used. The production method conforms to the production method of the polycarbonate resin (A) except that a heavy metal transesterification catalyst is not used.

Another suitable method for producing the polycarbonate resin (B) according to the present invention is an interfacial polymerization method in which a dihydroxy compound is reacted with phosgene in the presence of a solvent, a terminal terminator and an acid binder. Usually, a dihydroxy compound and a terminal terminator are dissolved in an aqueous solution of an acid binder and reacted in the presence of an organic solvent.
A known melt polycondensation method for carrying out the reaction in the presence is preferably used. Its manufacturing method is heavy metal

  As the acid binder, for example, pyridine, alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is preferably used, and as the solvent, for example, methylene chloride, chloroform, chlorobenzene, xylene and the like are suitable. Used for. Furthermore, in order to accelerate the polymerization reaction, a tertiary amine such as triethylamine or a quaternary ammonium salt such as tetra-n-butylammonium bromide is used as a catalyst.

  Moreover, as a terminal terminator used for adjustment of a polymerization degree, monofunctional hydroxy compounds, such as a phenol, p-tert-butylphenol, p-cumylphenol, and a long-chain alkyl substituted phenol, are used.

  Furthermore, if desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfite sodium may be added.

  The reaction is usually carried out in the range of 0 to 150 ° C, preferably 5 to 40 ° C. While the reaction time depends on the reaction temperature, it is generally 0.5 min-10 hr, preferably 1 min-2 hr. Moreover, it is preferable to maintain the pH of the reaction system at 10 or more during the reaction.

  The method for producing the blend resin composition of the present invention may be produced by mixing the polycarbonate resins (A) and (B) separately produced and kneading them with a kneader, or by melting them. The solid (B) may be added to the resin (A) in the state, or the solid (A) may be added to the molten resin (B) and kneaded with a kneader. Alternatively, the molten resins (A) and (B) may be mixed and kneaded with a kneader. The kneading may be performed continuously or batchwise. As the kneader, an extruder, a lab plast mill, a kneader, or the like is used. An extruder is preferably used for continuous kneading, and a lab plast mill or kneader is preferably used for batch kneading. In addition, when using the polycarbonate resin manufactured by the melt polycondensation method, it is desirable to perform kneading | mixing after a catalyst deactivation from the viewpoint of avoiding the transesterification reaction at the time of kneading | mixing. However, the catalyst deactivator and the resin to be blended may be kneaded at the same time, or the catalyst deactivator may be kneaded after blending. However, in this case, it is necessary to keep it within a range where chemical resistance is not impaired by randomization by transesterification.

  As another method for producing the blend resin composition of the present invention, there is a method in which the polycarbonate resins (A) and (B) are dissolved in a solvent, poured into a mold, and then the solvent is evaporated. As the solvent, for example, methylene chloride, chloroform, carbon tetrachloride, toluene and the like are used. When this method is used, it is convenient because the additive can be dissolved and added at the same time.

  Furthermore, it is preferable to add an antioxidant, a release agent, an ultraviolet absorber, a fluidity modifier, a bluing agent, a dye, an antistatic agent or an antibacterial agent to the blend resin composition of the present invention. Is done. These additives may be added in advance to (A), (B) or either resin before blend kneading, or they may be kneaded before blend kneading and added simultaneously during blend kneading. It may be kneaded or kneaded after blending.

The transparent protective sheet used for the polarizing plate of the present invention can be produced by molding the polycarbonate resin composition by a method such as a casting method, a melt pressing method, or an extrusion film forming method. The thickness of the transparent protective sheet is preferably from 0.05 mm to 5 mm, more preferably from 0.005 mm. 1 to 1 mm. If the thickness of the transparent protective sheet is thinner than 0.0 5 mm, is not preferred because breakage of the molded article is likely to occur when the strength of the polarizing plate was processed it becomes insufficient. On the other hand, if it is thicker than 5 mm, the handling during processing deteriorates, which is not preferable.

  Moreover, the preferable polystyrene conversion weight average molecular weight (Mw) of the polycarbonate resin (A) used for the blend resin composition used for this invention is 20,000-300,000, More preferably, 35,000-150. , 000. If Mw is less than 20,000, the transparent protective sheet becomes brittle, which is not preferable. If Mw is greater than 300,000, the melt viscosity will be high, making it difficult to remove the resin after production, and the solubility in the solvent will be poor, making it difficult to form a sheet by the casting method. Since melt viscosity becomes high, problems such as difficulty in extrusion molding occur, which is not preferable.

  The preferred polystyrene-converted weight average molecular weight (Mw) of the polycarbonate resin (B) used in the blend resin composition used in the present invention is 15,000 to 250,000, more preferably 20,000 to 110,000. It is. If Mw is less than 15,000, the blended resin composition becomes brittle, which is not preferable. When Mw is larger than 250,000, the melt viscosity becomes high and the blending conditions become severe, which is not preferable. Also, the solubility in a solvent is deteriorated, and it becomes difficult to form a sheet by the casting method. This is not preferable because of the problem that extrusion molding becomes difficult due to the increase in the thickness.

  The polystyrene-converted weight average molecular weight difference ΔMw between the polycarbonate resins (A) and (B) used in the blend resin composition of the present invention is preferably 0 to 120,000, more preferably 0 to 80,000. It is. When Mw exceeds 120,000, the difference in viscosity between (A) and (B) becomes remarkably large, so that the compatibility is deteriorated and the transparency of the blended resin composition is lowered, which is used for a transparent protective sheet for a polarizing plate. Since it becomes impossible, it is not preferable.

  The polycarbonate resin (A) used in the blend resin composition of the present invention contains random, block and alternating copolymer structures.

Preferably it has a glass transition temperature of the blend resin composition of the present invention (Tg) of a 9 0 to 180 ° C., more preferably from 1 00 ~1 70 ℃. When Tg is lower than 9 0 ° C., undesirably temperature range of the polarizing plate becomes narrow. On the other hand, if it exceeds 180 ° C., for example, the molding conditions for forming an extruded film become severe, which is not preferable.

  The polarizing film used in the polarizing plate of the present invention is not particularly limited as long as it is a thin film having a polarizing function, but a heat-resistant film is preferable in consideration of post-processing when it is used for anti-glare use after bending. . For example, a film obtained by adsorbing iodine or a dichroic dye on a polyvinyl alcohol film to be oriented by stretching is preferably used. As a method for producing a polarizing film, for example, a polymer film is immersed in an aqueous solution of 10 to 50 ° C. in which iodine or a dichroic dye is dissolved, and after the iodine or dichroic dye is adsorbed, the film is made of metal. It can manufacture by extending | stretching 2.5 to 8 times in one direction which is the state immersed in the 10-80 degreeC aqueous solution which melt | dissolved additives, such as ion and a boric acid. Although there is no restriction | limiting in particular in the thickness of a polarizing film, A 0.02-0.12 mm thing is normally used suitably from the surface of operativity.

  Although the polarizing plate of this invention is manufactured by bonding a transparent protective sheet on the one or both surfaces of the said polarizing film, the method of bonding on both surfaces is implemented more suitably. For the bonding, it is preferable to use an adhesive that is highly transparent, hardly colored over time, and excellent in heat resistance, and specifically, an acrylic, epoxy, or urethane adhesive is preferably used. .

  The surface of the polarizing plate of the present invention is subjected to a hard coat treatment, an antifogging treatment, a coloring treatment, an infrared reflection treatment, an infrared absorption treatment, an ultraviolet reflection treatment, an ultraviolet absorption treatment or the like depending on the application.

  The polarizing plate of the present invention is particularly effective when it is processed into a curved surface as well as a flat plate. Therefore, it is suitable for anti-glare applications such as sunglasses and goggles that are curved.

  Although there is no restriction | limiting in particular in the curved surface processing method of the polarizing plate of this invention, The processing methods, such as well-known vacuum forming, pressure forming, and press molding, can be selected suitably and can be implemented.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, the measured value in an Example was measured using the following method or apparatus.
1) Weight average molecular weight (Mw) in terms of polystyrene: A calibration curve was prepared using standard polystyrene having a known molecular weight (molecular weight distribution = 1) using GPC and chloroform as a developing solvent. Based on this calibration curve, it was calculated from the retention time of GPC.
2) Glass transition temperature (Tg): Measured with a differential thermal scanning calorimeter (DSC).

Production Example 1
9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene 10.11 kg (23.05 mol), tricyclo [5.2.1.0 ^2,6 ] decandimethanol 4.524 kg (23.05) Mol), 10.22 kg (47.71 mol) of diphenyl carbonate, and 0.01321 g (1.572 × 10 ⁻⁴ mol) of sodium bicarbonate were put into a 50 liter reactor equipped with a stirrer and a distiller, and a nitrogen atmosphere of 760 Torr. The mixture was heated to 215 ° C. over 1 hour and stirred.
Thereafter, the degree of vacuum was adjusted to 150 Torr over 15 minutes, and the transesterification reaction was carried out by maintaining for 20 minutes under the conditions of 215 ° C. and 150 Torr. Further, the temperature was raised to 240 ° C. at a rate of 37.5 ° C./hr, and maintained at 240 ° C. and 150 Torr for 10 minutes. Thereafter, the pressure was adjusted to 120 Torr over 10 minutes and maintained at 240 ° C. and 120 Torr for 70 minutes. Thereafter, the pressure was adjusted to 100 Torr over 10 minutes and held at 240 ° C. and 100 Torr for 10 minutes. Further, the polymerization reaction was carried out under stirring at 25 ° C. for 25 minutes under the condition of 1 Torr or less over 40 minutes at 240 ° C. After completion of the reaction, nitrogen was blown into the reactor to increase the pressure, and the produced polycarbonate resin was extracted while being pelletized. Mw = 87,000 of the obtained polycarbonate resin and Tg = 130 ° C. 10.0 kg of this polycarbonate resin was vacuum-dried at 100 ° C. for 24 hours, diethyl phosphite was added in an amount of 10 times mol of sodium hydrogen carbonate in the resin, and 300 ppm of glycerin monostearate was added to the resin. The mixture was kneaded at 0 ° C. and pelletized to obtain pellets. The Mw of this pellet was 85,800.

Production Example 2
In Production Example 1, 3.324 kg (23.05 mol) of cyclohexane-1,4-dimethanol was used in place of tricyclo [5.2.1.0 ^2,6 ] decanedimethanol, and over 45 minutes. The same operation as in Production Example 1 was performed except that the degree of vacuum was adjusted to 150 Torr. The obtained pellets had Mw = 81,400 and Tg = 120 ° C. Mw of the pellet after addition of the same additive as in Production Example 1 was 81,200.

Example 1
16 g of the polycarbonate resin obtained in Production Example 1 and 49 g of polycarbonate resin E-2000 (Mitsubishi Engineering Plastics Co., Ltd.) made of bisphenol A were kneaded for 6 minutes while blowing nitrogen with a lab plast mill set at 260 ° C. . The recovered resin composition was transparent, and only one inflection point was observed at Tg = 146 ° C., and it was confirmed that they were compatible. The resin composition was press-pressed under a pressure of 10 MPa for 1 minute at 240 ° C. to obtain a transparent protective sheet having a thickness of 0.3 mm.
A urethane adhesive was applied to both sides of a polarizing film prepared based on Example 1 of JP-A-63-311203, and the press sheet was attached to obtain a polarizing plate having a thickness of 0.65 mm. A disk having a diameter of 80 mm was cut out from this polarizing plate. The disk was vacuum-molded at 140 Pa and 500 Pa for 5 minutes using a spherical jig with a curvature radius of 80 mm to obtain a circular curved polarizing plate. Even when this curved polarizing plate was viewed from an oblique direction, no rainbow-colored unevenness was observed. Furthermore, even when the curved polarizing plate is observed with a flat polarizing plate disposed so that the polarization axes thereof are orthogonal to each other, light transmission, so-called color loss is not observed, and colored interference fringes are not observed. It was. The total light transmittance in this state was 0.4%. In addition, even when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are parallel to each other, coloring different from the polarizing film color is not observed in a part of the polarizing plate, and colored interference fringes are also observed. Not observed. From this, it was confirmed that the curved polarizing plate has extremely small optical distortion .

Example 2
A curved polarizing plate having a curvature radius of 80 mm was obtained in the same manner as in Example 1 except that 52 g of the polycarbonate resin synthesized in Production Example 1 and 13 g of polycarbonate resin E-2000 made of bisphenol A were used and the vacuum molding temperature was 128 ° C. Obtained. Even when this curved polarizing plate was viewed from an oblique direction, no rainbow-colored unevenness was observed. Furthermore, even when the curved polarizing plate is observed with a flat polarizing plate disposed so that the polarization axes thereof are orthogonal to each other, light transmission, so-called color loss is not observed, and colored interference fringes are not observed. It was. The total light transmittance in this state was 0.2%. In addition, even when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are parallel to each other, coloring different from the polarizing film color is not observed in a part of the polarizing plate, and colored interference fringes are also observed. Not observed. From this, it was confirmed that the curved polarizing plate has extremely small optical distortion .

Example 3
Example 1 except that 15 g of polycarbonate resin synthesized in Production Example 1 and polycarbonate resin E-2000 consisting of bisphenol A, 45 g were dissolved in 240 g of dichloromethane and a transparent protective sheet having a thickness of 0.15 mm was obtained by a casting method. In the same manner as above, a curved polarizing plate having a curvature radius of 80 mm was obtained. Even when this curved polarizing plate was viewed from an oblique direction, no rainbow-colored unevenness was observed. Furthermore, even when the curved polarizing plate is observed with a flat polarizing plate disposed so that the polarization axes thereof are orthogonal to each other, light transmission, so-called color loss is not observed, and colored interference fringes are not observed. It was. The total light transmittance in this state was 0.3%. In addition, even when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are parallel to each other, coloring different from the polarizing film color is not observed in a part of the polarizing plate, and colored interference fringes are also observed. Not observed. From this, it was confirmed that the curved polarizing plate has extremely small optical distortion .

Example 4
Curved polarized light having a radius of curvature of 80 mm in the same manner as in Example 1 except that 32 g of the polycarbonate resin pellets obtained in Production Example 2 and 32 g of Iupilon E-2000 pellets were kneaded by a lab plast mill and the vacuum forming temperature was 128 ° C. I got a plate. Even when this curved polarizing plate was viewed from an oblique direction, no rainbow-colored unevenness was observed. Furthermore, even when the curved polarizing plate is observed with a flat polarizing plate disposed so that the polarization axes thereof are orthogonal to each other, light transmission, so-called color loss is not observed, and colored interference fringes are not observed. It was. The total light transmittance in this state was 0.3%. In addition, even when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are parallel to each other, coloring different from the polarizing film color is not observed in a part of the polarizing plate, and colored interference fringes are also observed. Not observed. From this, it was confirmed that the curved polarizing plate has extremely small optical distortion .

Comparative Example 1
In Example 1, the same operation as Example 1 was performed except having used the polycarbonate sheet which consists of bisphenol A produced by the press molding method of thickness 0.3mm for the transparent protective sheet. When the obtained curved polarizing plate was viewed obliquely, iridescent color irregularities were observed. Further, when the curved polarizing plate was observed with a flat polarizing plate arranged so that the polarization axes thereof were orthogonal to each other, so-called color loss through which light was transmitted was observed, and colored interference fringes were observed. The total light transmittance in this state was 5.6%. In addition, when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are parallel to each other, coloring different from the polarizing film color is observed on a part of the polarizing plate, and colored interference fringes are observed. It was done. From this , it was confirmed that the curved polarizing plate has a large optical distortion and is not optically inferior but low in low birefringence.

Comparative Example 2
In Example 1, except for using polycarbonate sheet made of work made by bisphenol A by casting having a thickness of 0.15mm on the transparent protective sheet was subjected to the same procedure as in Example 1. When the obtained curved polarizing plate was viewed obliquely, iridescent color irregularities were observed. Further, when the curved polarizing plate was observed with a flat polarizing plate arranged so that the polarization axes thereof were orthogonal to each other, so-called color loss through which light was transmitted was observed, and colored interference fringes were observed. The total light transmittance in this state was 4.1%. In addition, when the curved polarizing plate is observed with a flat polarizing plate arranged so that the polarization axes thereof are parallel to each other, coloring different from the polarizing film color is observed on a part of the polarizing plate, and colored interference fringes are observed. It was done. From this , it was confirmed that the curved polarizing plate has a large optical distortion and is not optically inferior but low in low birefringence.

Claims (5)

A polycarbonate resin (A) obtained by carbonate bonding of 95 to 5 mol% of the dihydroxy compound represented by the general formula (1) and 5 to 95 mol% of the dihydroxy compound represented by the general formula (2) with a carbonic acid diester, and a structure A polycarbonate resin (B) obtained by carbonate-bonding a dihydroxy compound represented by the formula (3) with a carbonic acid diester or phosgene, (100 × (A)) / ((A) + (B)) = 1 to 99 A polarizing plate formed by laminating a transparent sheet made of a polycarbonate resin composition obtained by blending at a ratio of wt% and a polarizing film.

(In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group.)

(In the formula, X represents an alkylene group having 1 to 10 carbon atoms or a cycloalkylene group having 4 to 20 carbon atoms.)

The polarizing plate according to claim 1, wherein the compound represented by the general formula (2) is tricyclo [5.2.1.0 ^2,6 ] decanedimethanol and / or cyclohexane-1,4-dimethanol. The polarizing plate according to claim 1, wherein R ₁ in formula (1) is a hydrogen atom. The polarizing plate according to claim 1, wherein R ₁ and R _{2 in} formula (1) are hydrogen atoms. The antiglare polarizing plate according to claim 1, which is formed by processing a curved surface.