JP2005031611A - Polarizing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate in which optical strain is not substantially produced 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 obtained by bringing dihydroxy compounds represented by formula (1), the formula (2): HOCH<SB>2</SB>-Y-CH<SB>2</SB>OH, and formula (3) into carbonate linkage with a carbonic diester. <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 protective film made of a polycarbonate resin made of bisphenol A is adhered to both surfaces of a polarizing film to form a polarizing plate, and the polarizing plate is formed into a curved surface by vacuum forming, pressure forming or press forming. In this case, it has been found that the optical strain is caused by the stress strain of the curved surface portion, and the remarkable adverse effect is caused 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 is bonded 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, and the obtained convex lens-shaped polarized light is obtained. color unevenness even by observing the plate in an oblique direction that are described as were observed. Although it can be said that this method is effective and also used for actual production methods, besides being required orientation treatment by stretching in order to ensure the re-coater retardation value of PC sheet, axial polarizing substrate and the alignment axis Must be matched, and 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 the patent document, a transparent sheet made of a polycarbonate resin made of bisphenol A is prepared by a casting method, and then the polarizing sheet is manufactured by laminating the transparent sheet on both surfaces of a polarizing film to examine the polarization performance. However, in this patent document, the polarization performance when the curved surface of the polarizing plate having the transparent sheet made of polycarbonate resin made of bisphenol A is not processed is merely examined. 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 that is colored differently from the polarizing film or colored interference fringes is observed because the birefringence of the polycarbonate resin made of bisphenol A is large, that is, the intrinsic birefringence and light. This is because the elastic modulus is large. Therefore, various low birefringence resins have been tried as transparent protective sheets for polarizing films. However, for example, be processed into a polarizing plate by using amorphous polyolefin which is a typical low birefringence resin is a transparent sheet, the curved surface processing a polarizing plate on a convex lens shape, but not in a plane polarizer It has been found by the present inventors 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 shown a dihydroxy compound represented by general formula (1), a dihydroxy compound represented by general formula (2), and general formula (3). The present inventors have found that the above problem can be solved by a polarizing plate formed by laminating a polarizing film and a transparent sheet made of a polycarbonate resin obtained by carbonate-bonding a dihydroxy compound with a carbonic acid diester.

（式中、Ｒ₁およびＲ₂は、それぞれ独立に水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシル基、炭素数５〜２０のシクロアルキル基、炭素数５〜２０のシクロアルコキシル基、炭素数６〜２０のアリール基または炭素数６〜２０のアリールオキシ基を表す。また、式中、Ｘは炭素数２〜８のアルキレン基、炭素数５〜１２のシクロアルキレン基または炭素数６〜２０のアリーレン基を表す。）

Wherein R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or 5 to 20 carbon atoms. A cycloalkoxyl group, an aryl group having 6 to 20 carbon atoms or an aryloxy group having 6 to 20 carbon atoms, wherein X is an alkylene group having 2 to 8 carbon atoms and a cycloalkylene having 5 to 12 carbon atoms. Represents a group or an arylene group having 6 to 20 carbon atoms.)

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

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

（式中、Ｒ₃およびＲ₄は、それぞれ独立に水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシル基、炭素数５〜２０のシクロアルキル基、炭素数５〜２０のシクロアルコキシル基、炭素数６〜２０のアリール基または炭素数６〜２０のアリールオキシ基を表す。また、式中、Ｗは単結合、硫黄原子、酸素原子、スルホン基、炭素数１〜８のアルキリデン基、炭素数５〜２０のシクロアルキリデン基、炭素数７〜２０のアリールアルキリデン基、フルオレニリデン基またはα，α，α’，α’−テトラメチルキシリデン基を表す。）

(In the formula, R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or 5 to 20 carbon atoms. Represents a cycloalkoxyl group, an aryl group having 6 to 20 carbon atoms or an aryloxy group having 6 to 20 carbon atoms, wherein W is a single bond, a sulfur atom, an oxygen atom, a sulfone group, or 1 to 8 carbon atoms. An alkylidene group, a cycloalkylidene group having 5 to 20 carbon atoms, an arylalkylidene group having 7 to 20 carbon atoms, a fluorenylidene group, or an α, α, α ′, α′-tetramethylxylidene group.

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.

  Specific examples of the dihydroxy compound represented by the general formula (1) for deriving the polycarbonate resin used in the present invention include 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9. -Bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3,5-dimethylphenyl) fluorene, 9,9-bis (4 -(2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4- (2- Hydroxyethoxy) -3-cyclohexylphenyl) fluorene and the like are exemplified. Among them, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene is preferable.

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

  Specific examples of the dihydroxy compound represented by the general formula (3) for deriving the polycarbonate resin used in the present invention include 2,2-bis (4-hydroxyphenyl) propane (common name: bisphenol A), 1, 1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1- Bis (4-hydroxyphenyl) -1-phenylethane, 4,4 ′-(1,3-phenylene-bis (1-methylethylidene)) bisphenol, 4,4 ′-(1,4-phenylene-bis (1 -Methylethylidene)) bisphenol, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-H Loxyphenyl) ethane, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxy-3-propylphenyl) propane, 2,2-bis (4-hydroxy) -3- (1-methylethyl) phenyl) propane, 2,2-bis (4-hydroxy-3- (1-methylpropyl) phenyl) propane, 2,2-bis (4-hydroxy-3-tert-butyl) Phenyl) propane, 2,2-bis (4-hydroxy-3-cyclohexylphenyl) propane, 2,2-bis (4-hydroxy-3-phenylphenyl) propane, 2,2-bis (4-hydroxy-2-) Methyl-5- (1-methylethyl) phenyl) propane, 1,1-bis (4-hydroxy-3-tert-butyl-6- Tilphenyl) -2-methylpropane, 1,1-bis (4-hydroxy-3-tert-butyl-6-methylphenyl) butane, 1,1-bis (4-hydroxy-3-cyclohexyl-6-methylphenyl) 2-methylpropane, 2,2-bis (4-hydroxy-3-tert-butyl-6-methylphenyl) propane, 1,1-bis (4-hydroxy-3- (1-methylethyl) phenyl) cyclohexane 1,1-bis (4-hydroxy-3-tert-butylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3- (1-methylpropyl) phenyl) cyclohexane, 1,1-bis (4- Hydroxy-3-cyclohexylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-phenylphenyl) cyclohexa 1,1-bis (4-hydroxy-3- (1-methylethyl) phenyl) cyclopentane, 1,1-bis (4-hydroxy-3-cyclohexylphenyl) cyclopentane, 1,1- (4- Hydroxy-3-tert-butylphenyl)) cyclopentane, 9,9-bis (4-hydroxy-3- (1-methylethyl) phenyl) fluorene, 4,4 '-(1,3-phenylene-bis (1 -Methylethylidene)) bis- (2-cyclohexyl-5-methylphenol), 4,4 '-(1,4-phenylene-bis (1-methylethylidene)) bis- (2-cyclohexyl-5-methylphenol) 4,4 ′-(1,3-phenylene-bis (1-methylethylidene)) bis (2- (1-methylethyl) phenol), 1,1-bis (4-hydro Shi-3- (1-methylethyl) phenyl) -1-phenyl ethane, 1,1-bis (4-hydroxy -3-tert-butyl) -1-phenylethane and the like. Among them, 2,2-bis (4-hydroxyphenyl) propane (common name: bisphenol A) is preferable.

  Below, the manufacturing method of the polycarbonate resin in connection with this invention is described. 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.

  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 diphenyl carbonate is preferably used in a ratio of 0.97 to 1.20 mol, more preferably 0.98 to 1.10 mol, per 1 mol of the total of dihydroxy compounds.

  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 alkaline earth metal compounds, inorganic salts, oxides, hydroxides, hydrides or alkoxides, quaternary ammonium hydroxides and salts thereof, amines, and the like. These compounds 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, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, acetic acid. Cesium, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenyl borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, hydrogen phosphate Disodium, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenyl phosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 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 the nitrogen-containing compound include alkyl groups and aryl groups 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.

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, diethyl phosphite, di-n-propyl phosphite, phosphorous acid Phosphorous esters such as di-n-butyl, di-n-hexyl phosphite, dioctyl phosphite, monooctyl phosphite, triphenyl phosphate, diphenyl phosphate, monophenyl phosphate, dibutyl phosphate, phosphorus Phosphate esters such as dioctyl acid and monooctyl phosphate, phosphones such as diphenylphosphonic acid, dioctylphosphonic acid and dibutylphosphonic 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, and aromatics such as tetrabutylphosphonium dodecylbenzenesulfonate Organic halides such as aromatic sulfonates, 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.

The transparent protective sheet used in the polarizing plate of the present invention can be produced by molding the polycarbonate resin by a method such as a casting method, a melt press 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.

  The polycarbonate resin used in the present invention is a carbonate bond of a dihydroxy compound represented by the general formula (1), a dihydroxy compound represented by the general formula (2), and a dihydroxy compound represented by the general formula (3). This is a polycarbonate resin. The proportion of the dihydroxy compound represented by the general formula (1) in all the dihydroxy compounds is preferably 95 to 5 mol%. When the amount of the dihydroxy compound represented by the general formula (1) is less than 5 mol%, the birefringence of the polycarbonate resin is increased, which is not preferable. If it is more than 95 mol%, the fluidity becomes poor and it becomes difficult to mold in the molten state, which is not preferable.

  Moreover, the preferable polystyrene conversion weight average molecular weight (Mw) of the polycarbonate resin used for this invention is 20,000-300,000. 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, so that it will be 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. This is not preferable because of the problem that extrusion molding becomes difficult due to the increase in the thickness.

  The polycarbonate resin used in the present invention includes random, block and alternating copolymer structures.

Further, preferably has a glass transition temperature of the polycarbonate resin used in the present invention (Tg) of a 9 0 to 180 ° C., more preferably from 10 0 to 165 ° C.. When Tg is lower than 9 0 ° C., undesirably temperature range is narrowed. On the other hand, if the temperature exceeds 180 ° C., the molding conditions during extrusion molding become severe, which is not preferable.

  Furthermore, an antioxidant, a release agent, an ultraviolet absorber, a fluidity modifier, a crystal nucleating agent, a reinforcing agent, a dye, an antistatic agent, an antibacterial agent, or the like may be added to the polycarbonate resin used in the present invention. It is preferably implemented.

  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. . As the polymer film, for example, a film obtained by adsorbing iodine or a dichroic dye on a polyvinyl alcohol film and stretching and orientation 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 may be flat or curved and there is no limitation on its use. Therefore, it can be used for general polarizing plate applications and lens applications such as sunglasses and goggles by processing curved surfaces.

  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).

Example 1
4,298 kg (9.802 mol) of 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 1.924 kg of tricyclo [5.2.1.0 ^2,6 ] decanedimethanol (9.802) Mol), 2,2-bis (4-hydroxyphenyl) propane 6.050 kg (26.50 mol), diphenyl carbonate 10.37 kg (48.41 mol), and sodium hydrogen carbonate 0.01321 g (1.572 × 10 6 ^-4 mol) was placed in a 50 liter reactor equipped with a stirrer and a distiller, and heated to 215 ° C and stirred for 1 hour under a nitrogen atmosphere of 760 Torr.
Thereafter, the degree of vacuum was adjusted to 150 Torr over 15 minutes, and the transesterification reaction was carried out by maintaining for 30 minutes at 215 ° C. and 150 Torr. Further, the temperature was raised to 245 ° C. at a rate of 37.5 ° C./hr, and maintained at 245 ° C. and 150 Torr for 30 minutes. Thereafter, the pressure was adjusted to 120 Torr over 10 minutes, and maintained at 245 ° C. and 120 Torr for 90 minutes. Thereafter, the pressure was adjusted to 100 Torr over 10 minutes and held at 245 ° C. and 100 Torr for 30 minutes. Furthermore, the polymerization reaction was carried out with stirring for 80 minutes under conditions of 245 ° C. and 1 Torr or less at 1 Torr or less over 40 minutes. 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 = 74,100 of the obtained polycarbonate resin and Tg = 139 ° C. 10.0 kg of this polycarbonate resin was vacuum-dried at 100 ° C. for 24 hours, diethyl phosphite was added 10 times mol of sodium hydrogen carbonate in the resin, and 300 ppm of glycerin monostearate was added to the resin, and 260 times by an extruder. The mixture was kneaded at 0 ° C. and pelletized to obtain pellets. The Mw of the pellet was 73,700.
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 the polarizing film prepared based on the description in 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-formed at 500 Pa for 5 minutes at 133 ° C. using a spherical jig having 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 0.3%. 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 2
In Example 1, 1.998 kg (4.555 mol) of 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, tricyclo [5.2.1.0 ^2,6 ] decanedimethanol 8941 kg (4.555 mol), 2,2-bis (4-hydroxyphenyl) propane 8.444 kg (36.99 mol) diphenyl carbonate 10.47 kg (48.87 mol) were used, and 245 ° C., 1 Torr or less The same operation as in Example 1 was performed except that the polymerization reaction was performed with stirring for 100 minutes under the conditions described above. The obtained resin had Tg = 146 ° C. and Mw = 73,000. The additive was added in the same manner as in Example 1, and Mw of the pellet after extrusion was 72,200.
60 g of the pellets were dissolved in 240 g of dichloromethane, a transparent protective sheet having a thickness of 0.15 mm was obtained by a casting method, and a curved polarizing plate having a curvature radius of 80 mm was obtained in the same manner as in Example 1 except that the vacuum forming temperature was 140 ° 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 0.6%. 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
In Example 1, 6.973 kg (15.90 mol) of 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, tricyclo [5.2.1.0 ^2,6 ] decanedimethanol 121 kg (15.90 mol), 2,2-bis (4-hydroxyphenyl) propane 3.267 kg (14.31 mol), diphenyl carbonate 10.27 kg (47.94 mol) were used, and 245 ° C., 1 Torr. The same operation as in Example 1 was performed except that the polymerization reaction was performed with stirring for 60 minutes under the following conditions. The obtained resin had Tg = 131 ° C. and Mw = 75,900. The additive was added in the same manner as in Example 1, and Mw of the pellet after extrusion was 74,900. A curved polarizing plate having a curvature radius of 80 mm was obtained in the same manner as in Example 1 except that the pressing temperature was 230 ° C and the vacuum forming temperature was 125 ° C.
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 4
In Example 1, 4,495 kg (10.25 mol) of 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 1.478 kg (10.25 mol) of cyclohexane-1,4-dimethanol, The same operation as in Comparative Example 1 was performed except that 5.842 kg (25.59 mol) of 2,2-bis (4-hydroxyphenyl) propane was used and the degree of vacuum was adjusted to 150 Torr over 45 minutes. The obtained resin had Tg = 131 ° C. and Mw = 72,100. The radius of curvature was the same as in Example 1 except that the additive was added in the same manner as in Example 1 and the pressing temperature of Mw = 71,600 of the extruded pellet was 230 ° C. and the vacuum forming temperature was 125 ° C. An 80 mm curved polarizing plate 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 0.5%. 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 5
In Example 1, 4.075 kg (9.293 mol) of 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 2.438 kg (9.293 mol) of pentacyclopentadecanedimethanol, 2,2 -The same as in Comparative Example 1 except that 6.280 kg (27.51 mol) of bis (4-hydroxyphenyl) propane was used and the polymerization reaction was performed with stirring at 245 ° C under 1 Torr for 100 minutes. The operation was performed. The obtained resin had Tg = 148 ° C. and Mw = 75,500. The additive was added in the same manner as in Example, and Mw of the pellet after extrusion was 75,000.
A curved polarizing plate having a curvature radius of 80 mm was obtained in the same manner as in Example 1 except that the vacuum forming temperature was 142 ° C.
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 0.5%. 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 .
It was done.

Comparative Example 1
In Example 1, the same operation as in Example 1 was performed except that a polycarbonate sheet made of bisphenol A produced by a press molding method having a thickness of 0.3 mm was used as the transparent protective sheet, and the vacuum molding temperature was 140 ° C. It was.
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 that the 140 ° C. The vacuum forming temperature using a polycarbonate sheet made of work made by the bisphenol A with a transparent protective sheet to a thickness of 0.15mm casting method 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 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.

Claims (7)

A transparent sheet comprising a polycarbonate resin formed by carbonate bonding of a dihydroxy compound represented by the general formula (1), a dihydroxy compound represented by the general formula (2) and a dihydroxy compound represented by the general formula (3) with a carbonic acid diester And a polarizing plate formed by laminating a polarizing film.

Wherein R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or 5 to 20 carbon atoms. A cycloalkoxyl group, an aryl group having 6 to 20 carbon atoms or an aryloxy group having 6 to 20 carbon atoms, wherein X is an alkylene group having 2 to 8 carbon atoms and a cycloalkylene having 5 to 12 carbon atoms. Represents a group or an arylene group having 6 to 20 carbon atoms.)

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

(Wherein R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or 5 to 20 carbon atoms. Represents a cycloalkoxyl group, an aryl group having 6 to 20 carbon atoms or an aryloxy group having 6 to 20 carbon atoms, wherein W is a single bond, a sulfur atom, an oxygen atom, a sulfone group, or 1 to 8 carbon atoms. An alkylidene group, a cycloalkylidene group having 5 to 20 carbon atoms, an arylalkylidene group having 7 to 20 carbon atoms, a fluorenylidene group, or an α, α, α ′, α′-tetramethylxylidene group. The compound represented by the general formula (2) is at least one selected from tricyclo [5.2.1.0 ^2,6 ] decane dimethanol, cyclohexane-1,4-dimethanol and pentacyclopentadecane dimethanol. The polarizing plate according to claim 1. 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. The polarizing plate according to claim 1, wherein the compound represented by the general formula (2) is cyclohexane-1,4-dimethanol. The polarizing plate according to claim 1, wherein in the compound represented by the general formula (3), R ₃ and R ₄ are hydrogen atoms and W is an isopropylidene group. The polarizing plate according to claim 1, wherein in the compound represented by the general formula (1), R ₁ and R ₂ are hydrogen atoms and X is an ethylene group.   The antiglare polarizing plate according to claim 1, which is formed by processing a curved surface.