JP2003270435A - Wide-band wavelength plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a 1/4-wavelength plate which has superior sharpness of a display and has no decrease in the sharpness and is usable for a wide- wavelength band when installed on a liquid crystal display and used. <P>SOLUTION: The wide-band 1/4-wavelength plate is manufactured by stacking a 1/2-wavelength plate (A) and a 1/4-wavelength plate (B); and at least one of the plates consists principally of alicyclic structure containing polymer resin and the both are characterized in that the ratio Re(450)/Re(550) of the retardation value [Re(660)] measured at 25°C with a 550 nm wavelength and the retardation value [Re(450)] measured at 25°C with a 450 nm wavelength is ≤1.007 and a volatile component content is ≤0.1 wt.%. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a half-wave plate and 1
The present invention relates to a broadband 1/4 wavelength plate formed by laminating a / 4 wavelength plate and a circular polarizing plate formed by laminating a polarizing plate on the broadband 1/4 wavelength plate.

[0002]

2. Description of the Related Art A film obtained by stretching a thermoplastic resin sheet to have retardation can function as a wave plate. A half-wave plate and a quarter-wave plate using one such stretched film have been known. However, in the case of the quarter-wave plate using one stretched film, the phase difference is different for each wavelength, and there is a problem that the wavelength that can function as the quarter-wave plate is limited to a specific wavelength. . That is, for example, even if it functions as a quarter-wave plate for light having a wavelength of 550 nm, the wavelength is 450 nm or 650 nm.
Since it does not function as a quarter-wave plate with respect to the above-mentioned light, for example, when it is adhered to a polarizing plate to form a circularly polarizing plate and used as an antireflection filter for suppressing surface reflection of a display or the like, the wavelength There is a problem that it does not exhibit a sufficient antireflection function with respect to light not having a wavelength of 550 nm, and particularly has a poor antireflection function with respect to blue light, so that a display or the like looks blue. Further, when it is used in a reflective liquid crystal display device, there is a problem that contrast is lowered because light leakage occurs depending on the wavelength particularly when black display is performed.

In order to solve this problem, there has been proposed a quarter-wave plate in which a plurality of stretched films which give a phase difference of quarter wavelength and half wavelength are laminated with their optical axes crossing. (JP-A-5-100114). According to this
A phase difference of ¼ wavelength can be given over a wide wavelength range. Further, Japanese Patent Laid-Open No. 11-231132 discloses that
A stretched film which gives a retardation of ½ wavelength to a monochromatic light and a stretched film which gives a retardation of ¼ wavelength are laminated with their optical axes crossed, and at least one of the stretched films Has a photoelastic coefficient of 50 × 10 ⁻¹³ cm ² / dyn or less for light with a wavelength of 633 nm, and the wavelength dependence of birefringence difference Δn1 and Δn2 is 400 nm (Δ).
n1) and 550 nm (Δn2) light, Δn1 /
1/4, characterized in that Δn2 <1.05
Wave plates have been proposed. However, even when these wave plates are installed on the liquid crystal display, the contrast definition of the display and the quality maintenance in long-term use are not sufficiently satisfied.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides excellent display sharpness when installed and used on a liquid crystal display, and the sharpness is lowered even when used for a long period of time under high temperature and high humidity. First, it is to provide a quarter-wave plate that can be used in a wide wavelength band.

[0005]

As a result of earnest studies to solve the above problems, the present inventor has found that a half-wave plate and a
In bonding a four-wave plate to a broadband quarter-wave plate, a polymer resin containing an alicyclic structure is used as the material for at least one of the wave plates, and the wavelength dependence of the retardation is specified for all the wave plates. When the resulting laminated plate is used by being installed on a liquid crystal display, the black display of the display becomes clear by using a volatile component content of not more than a specified value and not more than a specific value. It has been found that, even when used for a long period of time in a high temperature and high humidity environment, a white spot defect or the like in which a peripheral portion of a display is white does not occur, and based on this finding, the present invention has been completed.

Thus, according to the present invention, there is provided (1) a broadband quarter-wave plate obtained by laminating a half-wave plate (A) and a quarter-wave plate (B). (A) or 1/4
At least one of the wave plates (B) is made of an alicyclic structure-containing polymer resin, and the retardation value measured at a wavelength of 550 nm for both the half wave plate (A) and the quarter wave plate (B). [Re (550)] and wavelength 450n
The ratio Re (450) / Re (550) to the retardation value [Re (450)] measured by m is 1.007 or less, and the half-wave plate (A) and the quarter-wave plate (B) are used. In any of the above, the retardation value R of the half-wave plate (A) measured with a broadband quarter-wave plate having a volatile component content of 0.1% by weight or less and (2) a wavelength of 550 nm.
e (550) _A is [265 ± 5] nm, and the retardation value Re (550) _{B of the} quarter-wave plate (B) is [Re (550) _A / 2 ± 5] nm. And (3) the crossing angle between the slow axis of the half wave plate (A) and the slow axis of the quarter wave plate (B) is 5
The broadband quarter-wave plate according to the above (1), (4) the half-wave plate (A) and 1 which are laminated so as to form an angle of 7 ° to 63 °.
/ 4 wavelength plate (B), the saturated water absorption is 0.01% or less, the broadband ¼ wavelength plate according to (1) above, (5) the polarizing plate above (1) to (4) Circularly polarizing plates formed by laminating the described broadband quarter-wave plates are provided respectively.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The broadband quarter-wave plate of the present invention is
A half wave plate (A) and a quarter wave plate (B) are laminated, and at least one of the half wave plate (A) and the quarter wave plate (B) contains an alicyclic structure. Made of polymer resin, 1
For both the 1/2 wave plate (A) and the 1/4 wave plate (B), the retardation value [Re (550)] measured at a wavelength of 550 nm and the retardation value [Re (450) measured at a wavelength of 450 nm. ] Ratio Re (45
0) / Re (550) is 1.007 or less, preferably 1.006 or less, and the ½ wavelength plate (A) and ¼
Each of the wave plates (B) is characterized in that the volatile component content is 0.1% by weight or less, preferably 0.05% by weight or less. The broadband quarter wave plate of the present invention is
The value of the ratio Re / λ of the retardation value (Re) and the wavelength λ hardly changes over a wide range of wavelength 400 nm to 700 nm. Re (450) / Re (550) is 1.
When it exceeds 007, when it is installed on a reflection type liquid crystal display, the contrast definition of the display is lowered. Further, when the volatile component content exceeds 0.1% by weight,
When used, the volatile component is released to the outside to cause a dimensional change in the wave plate and internal stress is generated, so that when used in a reflective liquid crystal display device, black display is partially thinned (looks whitish). There is a possibility that display unevenness such as the above may occur. Therefore, if the volatile content is in the above range,
Even if used for a long period of time, it is stable without causing uneven display on the display. Furthermore, the saturated water absorption is preferably 0.01% or less, and more preferably 0.007 for both the half-wave plate (A) and the quarter-wave plate (B).
% Or less. If the saturated water absorption exceeds 0.01%, the dimensional change of the wave plate occurs due to moisture absorption during use and internal stress is generated. When used in a reflective liquid crystal display device, black display is partially thin. There is a possibility that display unevenness, such as "(looks whitish)" may occur. Therefore, when the saturated water absorption is within the above range, the display is stable even after long-term use without causing display unevenness.

The broadband quarter wave plate of the present invention has a wavelength of 55
The retardation value Re (550) _{A of the half-} wave plate (A) measured at 0 nm is preferably [265 ± 5] n.
m, more preferably [265 ± 3] nm, 1/4
Retardation value Re (550) of the wave plate (B)
_B is preferably [Re (550) _A / 2 ± 5] nm,
More preferably, it is [Re (550) _A / 2 ± 3] nm. Re (550) _A is in the range of [265 ± 5] nm, and Re (550) _B is [Re (550) _A / 2 ± 5].
When it is in the range of nm, the quarter-wave plate obtained by laminating both can be used in a wider band. The variation in the in-plane retardation value (Re) of the half-wave plate (A) and the quarter-wave plate (B) at a wavelength of 550 nm is preferably ± 5.
nm, more preferably ± 3 nm, even more preferably ± 2
nm. When the variation of Re of the half-wave plate (A) and the quarter-wave plate (B) is within the above range, the quarter-wave plate obtained by laminating the both is excellent in optical uniformity, for example, polarized light. When a circularly polarizing plate is adhered to a plate and the circularly polarizing plate is used as an antireflection filter for suppressing surface reflection of a display or the like, there is no problem that the reflected light is partially colored. Furthermore, the broadband quarter wave plate of the present invention is 1 /
Laminating so that the crossing angle between the slow axis of the two-wave plate (A) and the slow axis of the one-quarter wave plate (D) is preferably 56 ° to 62 °, more preferably 57 ° to 61 °. To do. When the crossing angle of the slow axes of the respective wave plates is within the above range, a quarter wave plate having an excellent wide band property can be obtained. The slow axis is the direction in which the phase delay is maximized when linearly polarized light is incident on the retardation film, and in the case of a resin film in which the retardation film is stretched, usually its stretching direction, or orthogonal thereto. It is the direction to do.

At least one of the half-wave plate (B) and the quarter-wave plate (C) is made of an alicyclic structure-containing polymer resin. The alicyclic structure-containing polymer resin contains an alicyclic structure in the repeating unit of the polymer, and the alicyclic structure may be in either the main chain or the side chain. Examples of the alicyclic structure include a cycloalkane structure and a cycloalkene structure, and the cycloalkane structure is preferable from the viewpoint of thermal stability and the like. The number of carbon atoms constituting the alicyclic structure is usually 4 to 30, preferably 5 to 20.
The number is more preferably 5 to 15. When the number of carbon atoms constituting the alicyclic structure is within this range, a protective layer having excellent heat resistance and flexibility can be obtained. The proportion of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer resin may be appropriately selected according to the purpose of use, but is usually 50% by weight.
Or more, preferably 70% by weight or more, more preferably 90% by weight
It is more than weight%. If the proportion of the repeating unit having an alicyclic structure is excessively low, the heat resistance decreases, which is not preferable. The repeating unit other than the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer resin is appropriately selected according to the purpose of use.

Specific examples of the alicyclic structure-containing polymer resin include (1) a norbornene-based polymer, (2) a monocyclic cyclic olefin polymer, (3) a cyclic conjugated diene polymer,
(4) Vinyl alicyclic hydrocarbon polymer, and (1) to
Examples thereof include the hydride of (4). Among these,
From the viewpoint of heat resistance, mechanical strength, and the like, norbornene-based polymer hydrides, vinyl alicyclic hydrocarbon polymers and hydrides thereof are preferable.

Norbornene-based polymers include norbornene and its derivatives, tetracyclododecene and its derivatives,
A polymer of a monomer which is a main component of a norbornene-based monomer such as dicyclopentadiene and a derivative thereof, methanotetrahydrofluorene and a derivative thereof, and specifically, a ring-opening polymer of a norbornene-based monomer, a norbornene-based monomer and the same. Ring-opening copolymer with other ring-opening copolymerizable monomer, addition polymer of norbornene-based monomer, addition copolymer of norbornene-based monomer with other monomer copolymerizable therewith, and hydrogenation of The thing etc. are mentioned. Among these,
From the viewpoints of heat resistance, mechanical strength, etc., a ring-opening polymer hydride of a norbornene-based monomer is most preferable. In the present invention, in the alicyclic structure-containing resin, a repeating unit having a bicyclo [3.3.0] octane structure,
It is preferable to use a polymer containing 55 to 90% by weight. By using the alicyclic structure-containing polymer resin in which the content of the repeating unit having a bicyclo [3.3.0] octane structure in the polymer is within the above range, the variation in retardation is small and the polymer is stretched at a high ratio. However, a wave plate having excellent mechanical strength can be obtained. In order to keep the content of the repeating unit having a bicyclo [3.3.0] octane structure in the alicyclic structure-containing polymer resin within the above range, a norbornene-based polymer having a structure in which a five-membered ring is bonded to a norbornene ring is used. After polymerizing a monomer mixture containing 55 to 90% by weight of the total amount of monomers by a known metathesis ring-opening polymerization method, the carbon-carbon unsaturated bond of the ring is hydrogenated by a known method. The norbornene monomer having a structure five-membered ring is bonded to the norbornene ring, tricyclo [4.3.0.1 ^{2, 5]} dec-3,7-diene (common name dicyclopentadiene) and their derivatives (ring Having a substituent), 7,8-benzotricyclo [4.3.
0.1 ^2,5 ] deca-3-ene (1,4-methano-1,
4,4a, 9a-Tetrahydrofluorene (common name: methanotetrahydrofluorene) and its derivatives. These monomers may be used alone or in combination. In the present invention, the above-mentioned norbornene-based monomer having a structure in which a five-membered ring is bonded to the norbornene ring can be subjected to ring-opening copolymerization with another monomer copolymerizable therewith. Examples of the copolymerizable monomer include bicyclo [2.2.1] hept-2-ene (common name: norbornene) and its derivatives, tetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ] Dodeca-3
-Norbornene monomers such as ene (common name: tetracyclododecene) and its derivatives; monocyclic olefins such as cyclohexene, cycloheptene, cyclooctene and their derivatives; cyclic conjugated dienes such as cycloheptadiene and cyclohexadiene and their derivatives ; And the like.

The above-mentioned monomers are, for example, ruthenium,
A catalyst comprising a halide of a metal such as osmium, a nitrate or an acetylacetone compound, and a reducing agent;
Alternatively, a catalyst comprising a halide of a metal such as titanium, zirconium, tungsten, molybdenum or an acetylacetone compound and an organoaluminum compound;
To perform ring-opening polymerization of metathesis. The above-mentioned ring-opening polymer obtained is obtained by adding a known hydrogenation catalyst containing a transition metal such as nickel or palladium to the polymerization solution to hydrogenate carbon-carbon unsaturated bonds preferably 90% or more.

The molecular weight of the norbornene-based polymer, the monocyclic cyclic olefin polymer or the cyclic conjugated diene polymer is
It is appropriately selected depending on the purpose of use, but it is usually a weight average molecular weight in terms of polyisoprene or polystyrene measured by gel permeation chromatography of a cyclohexane solution (a toluene solution when the polymer resin is not dissolved), usually 5, 000 to 500,000, preferably 8,000 to 200,000, more preferably 10.0.
When it is in the range of 00 to 100,000, the mechanical strength of the film and the moldability are highly balanced, which is preferable.

The vinyl alicyclic hydrocarbon polymer is a polymer having a repeating unit derived from vinylcycloalkane or vinylcycloalkene, and examples thereof include a cycloalkane having a vinyl group and a vinyl group such as vinylcyclohexene and vinylcyclohexane. A cycloalkene having, namely, a polymer of a vinyl alicyclic hydrocarbon compound and a hydride thereof; a hydride of an aromatic ring portion of a polymer of a vinyl aromatic hydrocarbon compound such as styrene and α-methylstyrene;
Etc. can be used. A vinyl alicyclic hydrocarbon polymer is a random copolymer or block copolymer of a vinyl alicyclic hydrocarbon compound or a vinyl aromatic hydrocarbon compound and another monomer copolymerizable with these monomers. It may be a copolymer such as a polymer or a hydride thereof. Examples of the block copolymer include a diblock, a triblock, or a multiblock or a gradient block copolymer having more than that, but are not particularly limited. The molecular weight of the vinyl alicyclic hydrocarbon polymer is appropriately selected according to the purpose of use, but is determined by gel permeation chromatography of a cyclohexane solution (toluene solution if the polymer resin is insoluble). Weight average molecular weight in terms of isoprene or polystyrene, usually 10,000 to 300,000
When it is 0, preferably 15,000 to 250,000, and more preferably 20,000 to 200,000, the mechanical strength and molding processability of the molded article are highly balanced and suitable.

The glass transition temperature (Tg) of the alicyclic structure-containing polymer resin used in the present invention may be appropriately selected according to the purpose of use, but is preferably 80 ° C. or higher, more preferably 130 ° C. Is in the range of up to 200 ° C. Within this range, no deformation or stress occurs even when used at high temperatures, and the durability is excellent.

In the present invention, at least one of the half-wave plate (A) and the quarter-wave plate (B) is produced using the alicyclic structure-containing polymer resin. Specifically, the alicyclic structure-containing polymer resin is formed into a sheet and stretched. As the method for molding the alicyclic structure-containing polymer resin into a sheet, either a heat melt molding method or a solution casting method can be used, but the heat melt molding method is used from the viewpoint of reducing volatile components in the sheet. Is preferably used. The hot melt molding method can be classified in more detail into an extrusion molding method, a press molding method, an inflation molding method, an injection molding method, a blow molding method, a stretch molding method and the like. Among these methods, in order to obtain a wave plate excellent in mechanical strength and surface accuracy, it is preferable to use melt extrusion molding. The molding conditions are appropriately selected depending on the purpose of use and the molding method, but in the case of melt extrusion molding, the cylinder temperature is appropriately set within the range of preferably 100 to 400 ° C, more preferably 150 to 350 ° C. The thickness of the sheet is preferably 10 to 300 μm, more preferably 30 to 200 μm.
Is.

When the glass transition temperature of the transparent resin is Tg, the sheet is stretched preferably in the temperature range of Tg-30 ° C. to Tg + 60 ° C., more preferably Tg-10.
In the temperature range of ℃ to Tg + 50 ℃, preferably 1.0
It is performed at a draw ratio of 1 to 2 times. The stretching may be uniaxial stretching or biaxial stretching, but the stretching direction in the case of uniaxial stretching may be the mechanical flow direction of resin (extrusion direction) when the sheet is obtained by extrusion molding. The stretching method is preferably a free shrink uniaxial stretching method, a fixed width uniaxial stretching method, or the like. The stretching speed is preferably 5 to 1000 mm /
Seconds, more preferably 10 to 750 mm / second. When the stretching speed is in the above range, the stretching can be easily controlled, and a wave plate having a small in-plane variation in surface accuracy and retardation can be obtained.

In the present invention, the half-wave plate (A) and 1
As a method for laminating the / 4 wavelength plate (B), a known method for laminating wave plates such as a method of laminating with a viscous adhesive, a method of laminating by heat welding or ultrasonic fusion, and a coextrusion method. Although it can be used, it is preferable to laminate using a tacky adhesive in order to use it as a broadband quarter-wave plate in a wider wavelength range and to have excellent durability.

Circular Polarizing Plate The broadband quarter-wave plate of the present invention functions as a circular polarizing plate when laminated with a polarizing plate. The circularly polarizing plate formed by laminating the quarter-wave plate and the polarizing plate of the present invention has excellent color balance of display, good contrast and clear display when used in a reflective liquid crystal display device. You can In addition, when used as an antireflection filter, 400 to 7
It exerts a sufficient antireflection function over a wide wavelength range of 00 nm. In order to laminate the broadband ¼ wavelength plate of the present invention and the polarizing plate, the ½ wavelength plate (A) and the polarizing plate are laminated via an adhesive layer. In this case, the polarization axis of the polarizing plate and 1
The crossing angle with the slow axis of the / 2 wave plate (A) is 13 to 17
The layers are laminated so that the angle becomes, preferably 14 ° to 16 °.

[0020]

EXAMPLES The present invention will be described more specifically below with reference to production examples, examples and comparative examples. [Parts] and [%] in these examples are based on weight unless otherwise specified. However, the present invention is not limited to these production examples and examples.

Various physical properties were measured by the following methods. (1) Molecular weight Tetrahydrofuran (THF) was used as a solvent and measured by GPC, and standard polystyrene equivalent weight average molecular weight (Mw)
I asked. (2) Molecular weight distribution Using tetrahydrofuran (THF) as a solvent, measured by GPC, standard polystyrene equivalent weight average molecular weight (Mw)
And the number average molecular weight (Mn) are calculated, and the weight average molecular weight (M
The ratio (Mw / Mn) of w) and the number average molecular weight (Mn) was calculated. (3) Glass transition temperature (Tg) It was measured by DSC based on JIS K7121. (4) Hydrogenation rate The hydrogenation rates of the main chain and aromatic ring of the polymer were measured by ¹ H-NMR.
Was measured and calculated. (5) Sheet thickness offline thickness measurement device (TOF-4R manufactured by Yamabun Electric)
Was measured using.

(6) Method for measuring the amount of volatile components The amount of volatile components contained in the film was quantified by gas chromatography as the total of components having a molecular weight of 200 or less. (7) Method for measuring saturated water absorption The saturated water absorption of the film was measured according to JIS K7209. (8) Measurement of Retardation Value (Re) It was measured by KOBRA-21ADH manufactured by Oji Scientific Instruments. (9) Optical performance of wideband quarter-wave plate A circularly polarizing plate manufactured by the following method is installed on a reflection type liquid crystal display device equipped with a reflection plate, and the liquid crystal display device displays black (the front is black). Display), and the definition of black display as viewed through the circularly polarizing plate was evaluated. When the black tone of black display is a uniform and dark tone over the entire screen [Good], when the black tone of black display is a light tone [Slightly bad], the black tone is not good over the entire screen. If it is uniform or looks grayish, it is considered as "bad". (10) Durability evaluation Two liquid crystal display devices each having a circularly polarizing plate whose optical performance was evaluated as described above were left in the following environments, respectively. (Durability test A) Temperature 30 ° C., humidity 40% 30
Leave for 30 days (endurance test B) in an environment of temperature 25 ° C and humidity 80%
The state of black display observed through each circularly polarizing plate was left for a day and evaluated. If the uniformity or tone of the black display is not changed, it is considered as "good", and if the peripheral edge of the screen appears grayish (white spots) (shown in FIG. 2), it is considered as "bad".

[Production Example 1] Siku dehydrated in a nitrogen atmosphere
To 500 parts of rohexane, 0.82 parts of 1-hexene and dib
Chill ether 0.15 parts, triisobutylaluminum
0.30 parts were put in a reactor at room temperature and mixed, and then the temperature was raised to 45 ° C.
While holding, tricyclo [4.3.0.1 ^2,5] Deca
-3,7-diene (dicyclopentadiene, hereinafter DC
Abbreviated as P) 80 parts, 1,4-methano-1,4,4a, 9
a-Tetrahydrofluorene (hereinafter abbreviated as MTF) 5
0 parts, and tetracyclo [4.4.0.1^2,5． 1
^{7, 1 0}] Dodeca-3-ene (hereinafter abbreviated as TCD) 7
0 parts of norbornene-based monomer mixture and hexachloride
40 parts of tungsten (0.7% toluene solution) and 2 parts
Polymerization was carried out by continuously adding over time. Butyl in polymerization solution
1.06 parts of glycidyl ether and isopropyl alcohol
0.52 parts of the polymerization catalyst to inactivate the polymerization catalyst
Stopped.

Then, to 100 parts of the reaction solution containing the obtained ring-opening polymer, 270 parts of cyclohexane was added, and further 5 parts of a nickel-alumina catalyst (manufactured by JGC Chemical Co., Ltd.) as a hydrogenation catalyst was added, and hydrogen was added. Then, the pressure was increased to 5 MPa with stirring and the temperature was raised to 200 ° C. with stirring, and then the reaction was carried out for 4 hours to obtain a reaction solution containing 20% of DCP / MTF / TCD ring-opening polymer hydrogenated polymer. After removing the hydrogenation catalyst by filtration, an antioxidant (manufactured by Ciba Specialty Chemicals; Irganox 1010)
The resulting solution was added and dissolved (0.1 part per 100 parts of polymer). Then, using a cylindrical concentrating dryer (manufactured by Hitachi, Ltd.), at a temperature of 270 ° C. and a pressure of 1 kPa or less,
From the solution, the hydrogenated polymer was extruded in a molten state into a strand form from an extruder while removing the solvent cyclohexane and other volatile components, cooled, pelletized and recovered. The copolymerization ratio of each norbornene-based monomer in the polymer was calculated from the composition of the residual norbornenes in the solution after polymerization (by the gas chromatography method).
P / MTF / TCD = 40/25/35, which was almost equal to the charge composition. This ring-opened polymer hydrogenated product had a weight average molecular weight (Mw) of 35,000 and a hydrogenation rate of 99.9.
%, Tg was 134 ° C.

[Production Example 2] 170 parts of DCP and 8-ethyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ]
Polymerization and hydrogenation reaction were carried out in the same manner as in Production Example 1 except that a norbornene-based monomer mixture consisting of 30 parts of dodeca-3-ene (hereinafter abbreviated as ETD) was used to obtain a hydrogenated product of a ring-opening polymer. This ring-opened polymer hydrogenated product had a weight average molecular weight (Mw) of 35,000 and a hydrogenation rate of 99.
9% and Tg was 105 ° C.

Production Example 3 600 parts of dehydrated toluene, 30 parts of 1-hexene, and 8-methyl-under a nitrogen atmosphere.
8-carboxymethyltetracyclo [4.4.0.1
^2,5 . 200 parts of [ ^17,10 ] dodeca-3-ene were placed in a reactor at room temperature and mixed, and then the solution was heated to 60 ° C. Then, 0.5 parts of a toluene solution of triethylaluminum (1.5 mol / l) as a polymerization catalyst and tungsten hexachloride modified with t-butanol and methanol (t-butanol: methanol :) in the solution in the reactor.
3.0 parts of a toluene solution (concentration: 0.05 mol / l) of tungsten = 0.35 mol: 0.3 mol: 1 mol) was added, and the system was heated and stirred at 80 ° C. for 3 hours for polymerization. Then, with respect to 400 parts of the reaction solution containing the obtained ring-opening polymer, RuHCl (CO) [P
(C ₆ H ₅ ) ₃ ] 3.0 parts are added, and hydrogen is added to 10 MP.
a, and heated to a temperature of 165 ° C. with stirring, and allowed to react for 3 hours to give 8-methyl-8-carboxymethyltetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ]
-3-Dodecene ring-opening polymer A reaction solution containing 24% of hydrogenated polymer was obtained. An antioxidant (Ciba Specialty Chemicals; Irganox 1) was added to the obtained solution.
010) was added and dissolved in an amount of 0.3 part per 100 parts of the polymer. Next, a cylindrical concentrating dryer (manufactured by Hitachi Ltd.)
At a temperature of 295 ° C. and a pressure of 1 kPa or less, while excluding the solvent toluene and other volatile components from the solution, the hydrogenated polymer is extruded in a molten state into a strand form from an extruder, cooled, and then pelletized and recovered. did. The weight average molecular weight (Mw) of this hydrogenated ring-opening polymer was 72,
000, the hydrogenation rate was 99.9%, and the Tg was 167 ° C.

Production Example 4 Polymerization and hydrogenation reaction were carried out in the same manner as in Production Example 1 except that the temperature was changed to 270 ° C. and the pressure was changed to 10 kPa in a cylindrical concentrating dryer to obtain a hydrogenated product of a ring-opening polymer. . This ring-opened polymer hydrogenated product had a weight average molecular weight (Mw) of 35,000, a hydrogenation rate of 99.9%, and T
g was 132 ° C.

Example 1 The pellets obtained in Production Example 1 were dried at 70 ° C. for 2 hours by using a hot air dryer in which air was passed to remove water, and then a resin provided with a screw of 65 mmφ. Using a T-die type film melt extrusion molding machine having a melt-kneading machine, a film having a thickness of 100 μm was extruded under the molding conditions of a molten resin temperature of 240 ° C. and a T-die width of 300 mm. The obtained 100 μm film was stretched by uniaxial stretching of free shrinkage at a stretching speed of 100 mm / sec and a stretching temperature of 140 ° C. to produce the following two types of wave plates. Stretched at a draw ratio of 1.3 times: 1/2 wave plate (A) Stretched at a draw ratio of 1.5 times: 1/4 wave plate (B) Wave plate (A) and wave plate (B) When the amount of volatile components and the saturated water absorption were measured by the above methods, they were 0.01% or less and 0.007%, respectively. The retardation values [Re (550)] at a wavelength of 550 nm of the wave plate (A) and the wave plate (B) are 265, respectively.
nm, 132.5 nm, and the ratio Re (450) / Re (550) between Re (550) and the retardation value [Re (450)] at a wavelength of 450 nm is 1.0.
It was 051.

Commercially available two-component urethane adhesive (main agent: ethyl acetate solution of polyester polyurethane resin, WWA-608S manufactured by Nippon Polyurethane Company, curing agent: ethyl acetate solution of polyisocyanate, H manufactured by Nippon Polyurethane Company)
ARDENER 110), main agent: hardener = 100: 1
The mixture was mixed at a weight ratio of 0, and butyl acetate and cyclohexane were added thereto so as to be 2% with respect to the solid content, and then diluted with ethyl acetate so that the total solid content concentration was 20%. . This is referred to as adhesive 1.

Adhesive 1 was applied to both sides of the above wave plate (A) using a roll coater, and warm air of 100 ° C. was blown at a wind speed of 1
The adhesive was dried by spraying at 0 m / sec for 90 seconds. Next, the wave plate (B) is attached to one surface of the wave plate (A) so that the crossing angle of the respective slow axes is 59 °, and the other surface of the wave plate (A) is a polarizing plate (dyed). A stretched polyvinyl alcohol polarizing film having a triacetyl cellulose protective film adhered on both sides thereof) so that the crossing angle between the polarizing axis of the polarizing plate and the slow axis of the wave plate (A) is 15 °. Crimped at 70 ℃ with thermocompression roll, and 3 at 40 ℃
After aging for a day, a circularly polarizing plate was obtained. FIG. 1 shows a laminated structure of circularly polarizing plates.

The circularly polarizing plate is placed on a liquid crystal display element having a reflecting plate on the back surface so that the quarter-wave plate (B) faces the liquid crystal display element, and the optical performance and durability are measured by the above method. Was evaluated. The results are shown in Table 1.

[0032]

[Table 1]

Example 2 A half-wave plate (A) and a quarter-wave plate (B) were obtained in the same manner as in Example 1 except that the pellet obtained in Production Example 2 was used. Table 1 shows the amounts of volatile components, saturated water absorption, Re (550) and Re (450) / Re (550) of the wave plate (A) and the wave plate (B). Hereinafter, a circularly polarizing plate was manufactured in the same manner as in Example 1 and placed on a liquid crystal display device to evaluate optical performance and durability. The results are shown in Table 1.
Described in.

Comparative Example 1 Production Example 3 The resin obtained was dissolved in toluene to a concentration of 30%, and a PET film (Lumirror manufactured by Toray Industries, Inc.) was used with a bar coater to form a 400 μm film. Apply so that the thickness becomes 5
After primary drying at 0 ° C., secondary drying was performed at 90 ° C. and then peeling from the PET film to obtain a resin film having a thickness of 100 μm. The residual solvent content of the obtained film was 0.
It was 9%. The obtained 100 μm film was used for 10
The following two types of wave plates were manufactured by uniaxial stretching with free shrinkage at a stretching speed of 0 mm / sec and a stretching temperature of 170 ° C. Stretched at a draw ratio of 1.45: 1/2 wave plate (A) Stretched at a draw ratio of 1.75: 1/4 wave plate (B) Wave plate (A) and wave plate (B) Amount of volatile components, saturated water absorption, Re (550) and Re (450) / Re (55
0) is described in Table 1. Hereinafter, a circularly polarizing plate was manufactured in the same manner as in Example 1 and placed on a liquid crystal display device to evaluate optical performance and durability. The results are shown in Table 1.

Comparative Example 2 Example 1 was repeated except that the resin pellets obtained in Production Example 3 were used, the drying temperature with a hot air dryer was 90 ° C., and the molten resin temperature with a melt extrusion molding machine was 280 ° C. A film having a thickness of 100 μm was extruded in the same manner as in. Then, stretching was performed in the same manner as in Comparative Example 1 to obtain a half-wave plate (A) and a quarter-wave plate (B). Amount of volatile components of wave plate (A) and wave plate (B), saturated water absorption, Re (550) and Re (450) / Re (5
50) is described in Table 1. Hereinafter, a circularly polarizing plate was manufactured in the same manner as in Example 1 and placed on a liquid crystal display device to evaluate optical performance and durability. The results are shown in Table 1.

Comparative Example 3 A half-wave plate (A) and a quarter-wave plate (B) were obtained in the same manner as in Example 1 except that the pellet obtained in Production Example 4 was used. Table 1 shows the amounts of volatile components, saturated water absorption, Re (550) and Re (450) / Re (550) of the wave plate (A) and the wave plate (B). Hereinafter, a circularly polarizing plate was manufactured in the same manner as in Example 1 and placed on a liquid crystal display device to evaluate optical performance and durability. The results are shown in Table 1.
Described in.

Comparative Example 4 A quarter wave plate (B) was obtained in the same manner as in Example 1 except that the pellet obtained in Production Example 4 was used, and the pellet obtained in Production Example 1 was used. A half-wave plate (A) was obtained in the same manner as in Example 1. Amount of volatile components of the wave plate (A) and the wave plate (B), saturated water absorption rate, Re (55
0) and Re (450) / Re (550) are shown in Table 1. Hereinafter, a circularly polarizing plate was manufactured in the same manner as in Example 1 and placed on a liquid crystal display device to evaluate optical performance and durability. The results are shown in Table 1.

From the evaluation results shown in Table 1 above, it can be seen that both the half-wave plate (A) and the quarter-wave plate (B) are Re
(450) / Re (550) is 1.007 or less,
Broad band 1 / of the present invention in which the amount of volatile components is 0.01% or less
The circularly polarizing plate using the four-wave plate has a clear contrast of the liquid crystal display screen and is excellent in durability (Example 1,
2). On the other hand, both the half-wave plate (A) and the quarter-wave plate (B) have Re (450) / Re (55
The circularly polarizing plate using the 1/4 wavelength plate in which 0) exceeds 1.007 has poor liquid crystal display screen contrast (Comparative Example 2) and high saturated water absorption rate (Comparative Example 1 and Comparative Example 2). Large amount of volatile components (Comparative Example 1 and Comparative Example 3)
The durability is reduced. Also, a quarter wave plate (B)
A circularly polarizing plate using a quarter-wave plate whose only volatile component exceeds 0.1% has poor durability.

[0039]

According to the present invention, when it is installed on a liquid crystal display and used, the sharpness of the display is excellent, and the sharpness does not decrease even if it is used for a long period under high temperature and high humidity. A quarter-wave plate that can be used in a wide wavelength band is provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a circularly polarizing plate.

FIG. 2 is a diagram showing a configuration of a circularly polarizing plate.

[Fig. 3] Fig. 3 shows a defect display (white spots) on a liquid crystal display screen.
It is a figure showing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Broadband 1/4 wavelength plate 2 ... Circular polarizing plate 3 ... Polarizing plate 4 ... Polarizing axis 5 of polarizing plate ... 1/2 wavelength plate (A) 6 ... (A) slow axis 7 ... 1/4 wavelength plate (B) 8 ... Slow axis 9 of (B) 9 ... Intersection angle of slow layer axis of wave plate (A) and wave plate (B) 10 ... Polarization axis of polarizing plate and slow axis of wave plate (A) Crossing angle 11 ... Adhesive layer 12 ... Defective liquid crystal display element (white spot)

Claims (5)

[Claims] 1. A broadband quarter-wave plate formed by laminating a half-wave plate (A) and a quarter-wave plate (B).
At least one of the half wave plate (A) and the quarter wave plate (B) is made of a polymer resin containing an alicyclic structure, and is either a half wave plate (A) or a quarter wave plate (B). Also about
Retardation value measured at a wavelength of 550 nm [Re
(550)] and the retardation value [Re (450)] measured at a wavelength of 450 nm, Re (450) / Re
(550) is 1.007 or less, and in both the half-wave plate (A) and the quarter-wave plate (B), the volatile component content is 0.1 wt% or less. Four
Wave plate. 2. The retardation value Re (550) _{A of the half-} wave plate (A) measured at a wavelength of 550 nm is [2.
65 ± 5] nm, and the retardation value Re (550) _{B of the} quarter-wave plate (B) is [Re (550) _A / 2.
The broadband quarter-wave plate according to claim 1, which is ± 5] nm. 3. A slow axis of a half wave plate (A) and a quarter wave.
The broadband quarter-wave plate according to claim 1, wherein the wavelength plate (B) is laminated so that the crossing angle with the slow axis is 57 ° to 63 °. 4. The broadband quarter-wave plate according to claim 1, wherein both the half-wave plate (A) and the quarter-wave plate (B) have a saturated water absorption of 0.01% or less. 5. A wide band 1 according to claim 1, which is a polarizing plate.
A circularly polarizing plate formed by stacking quarter wave plates.