CN1906509A - Polarizing plate with optical compensating layer, and image display using the same - Google Patents

Polarizing plate with optical compensating layer, and image display using the same Download PDF

Info

Publication number
CN1906509A
CN1906509A CN 200580001718 CN200580001718A CN1906509A CN 1906509 A CN1906509 A CN 1906509A CN 200580001718 CN200580001718 CN 200580001718 CN 200580001718 A CN200580001718 A CN 200580001718A CN 1906509 A CN1906509 A CN 1906509A
Authority
CN
China
Prior art keywords
optical compensating
compensating layer
liquid crystal
polarizer
layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN 200580001718
Other languages
Chinese (zh)
Other versions
CN100380206C (en
Inventor
千叶刚
冈田裕之
北村吉绍
首藤俊介
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nitto Denko Corp
Original Assignee
Nitto Denko Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nitto Denko Corp filed Critical Nitto Denko Corp
Publication of CN1906509A publication Critical patent/CN1906509A/en
Application granted granted Critical
Publication of CN100380206C publication Critical patent/CN100380206C/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Liquid Crystal (AREA)
  • Polarising Elements (AREA)

Abstract

A polarizing plate with an optical compensation layer capable of appropriately preventing leakage of light in black display while preventing thermal unevenness and contributing to reduction in thickness, and an image display employing it. The polarizing plate with an optical compensation layer comprises a polarizer, a first optical compensation layer, a second optical compensation layer, and a third optical compensation layer arranged in this order. The first, second and third optical compensation layers respectively have a predetermined absolute value of photoelastic coefficient, refractive index distribution, in-plane phase difference and/or phase difference in the thickness direction, respectively. The angle between the absorption axis of the polarizer and the lag axis of the first optical compensation layer is 10-30 DEG, the angle between the absorption axis of the polarizer and the lag axis of the second optical compensation layer is 70-95 DEG, and the angle between the absorption axis of the polarizer and the lag axis of the third optical compensation layer is 70-95 DEG.

Description

Be furnished with the Polarizer of optical compensating layer and use the image display device of this Polarizer
Technical field
The present invention relates to dispose the Polarizer of optical compensating layer, and the image display device that uses this Polarizer.Specifically, the Polarizer that disposes optical compensating layer of light leak when the present invention relates to help to reduce thickness and prevent the inhomogeneous demonstration that causes owing to temperature and can prevent black display well, and the image display device that uses this Polarizer.
Background technology
Except transmission liquid crystal display device and reflective LCD device, also propose to have transflective liquid crystal display device (for example, referring to JP11-242226A and JP2001-209065A) in the liquid crystal indicator of VA pattern.The transflective liquid crystal display device is utilized extraneous light in bright place as reflective LCD device, and allows to come identification to show with for example internal light source of backlight in dim place.That is, the transflective liquid crystal display device has adopted the display system in conjunction with reflective-mode and transmission mode, and according to the brightness of its environment display mode is switched to reflective-mode or transmission mode.As a result, show, therefore be applicable to the display part of mancarried device even the transflective liquid crystal display device also can provide clearly under the situation that consumption electric power reduces and surrounding environment is dim.
The object lesson of such transflective liquid crystal display device is for comprising the liquid crystal indicator of reflectance coating on the inboard of infrabasal plate, this reflectance coating has the light transmissive form part that is used for that forms on metal films such as aluminium, and this reflectance coating serves as the Transflective plate.In the liquid crystal indicator of reflective-mode, the extraneous light of injecting from the upper substrate side passes liquid crystal layer, reflects on the reflectance coating of infrabasal plate inboard, passes liquid crystal layer subsequently once more, penetrates from the upper substrate side, thereby shows.Simultaneously, in the liquid crystal indicator of transmission mode, the light of the backlight of injecting from the infrabasal plate side passes the form part of reflectance coating and passes liquid crystal layer, penetrates from the upper substrate side then, thereby shows.Therefore, form in the zone at reflectance coating, the zone that is formed with the form part becomes the transmission viewing area, and all the other zones become the reflective display region territory.
But in traditional VA mode reflection formula or transflective liquid crystal display device, light leak problem during black display and contrast reduce problem, are not resolved for a long time.
Summary of the invention
Finish the present invention for solving above-mentioned traditional problem, therefore the object of the present invention is to provide the Polarizer that disposes optical compensating layer of light leak in the time of can helping to reduce thickness and prevent the inhomogeneous demonstration that causes owing to temperature and can prevent black display well, and the image display device that uses this Polarizer.
(mode of dealing with problems)
According to an embodiment of the invention, the Polarizer that disposes optical compensating layer comprises polaroid, first optical compensating layer, second optical compensating layer and the 3rd optical compensating layer successively.First optical compensating layer contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2The resin of/N has the relation of nx＞ny=nz, and phase differential Re in its face 1Be 200 to 300nm; Second optical compensating layer contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2The resin of/N has the relation of nx＞ny=nz, and phase differential Re in its face 2Be 90 to 160nm; The 3rd optical compensating layer has the relation of nx=ny＞nz, phase differential Re in its face 3Be 0 to 20nm, and the phase differential Rth of its thickness direction 3Be 30 to 300nm.The slow axis of the absorption axes of polaroid and first optical compensating layer forms 10 ° to 30 ° angle; The slow axis of the absorption axes of polaroid and second optical compensating layer forms 70 ° to 95 ° angle; The slow axis of the absorption axes of polaroid and the 3rd optical compensating layer forms 70 ° to 95 ° angle.
In an embodiment of the invention, the thickness of the 3rd optical compensating layer is 1 to 50 μ m.
In yet another embodiment of the present invention, the 3rd optical compensating layer is made of the cholesteric orientation fixed bed that the selective reflecting wavelength region may is less than or equal to 350nm.
Perhaps, the 3rd optical compensating layer comprises by the relation with nx=ny＞nz and contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2The cholesteric orientation fixed bed that the film formed layer of the resin of/N and selective reflecting wavelength region may are less than or equal to 350nm.
According to a further aspect in the invention, provide liquid crystal panel.This liquid crystal panel comprises above-mentioned Polarizer and the liquid crystal cells that disposes optical compensating layer.
In an embodiment of the invention, above-mentioned liquid crystal cells is the VA pattern of reflective or semi-transmission-type.
According to another aspect of the invention, provide liquid crystal indicator.This liquid crystal indicator comprises above-mentioned liquid crystal panel.
In accordance with a further aspect of the present invention, provide image display device.This image display device comprises the above-mentioned Polarizer that disposes optical compensating layer.
(invention effect)
As mentioned above, according to the present invention, the angle that forms between each slow axis of the absorption axes of polaroid and first optical compensating layer (λ/2 plates), second optical compensating layer (λ/4 plates) and the 3rd optical compensating layer (negative electrode C plate) is set in the preset range, thus the light leak when obviously improving the black display of the reflective and transflective liquid crystal display device of VA pattern particularly.The 3rd optical compensating layer (negative electrode C plate) is made of cholesteric orientation fixed bed by using liquid crystal material and chiral reagent, obviously reduces thereby compare thickness with traditional negative electrode C plate.As a result, the present invention can greatly help to reduce the thickness of image display device.And, by reducing the thickness of the 3rd optical compensating layer (negative electrode C plate), can prevent significantly because the inhomogeneous demonstration that temperature causes.
Description of drawings
Fig. 1 is the schematic cross-section that disposes the Polarizer of optical compensating layer according to the preferred embodiment of the present invention;
Fig. 2 is the decomposition diagram that disposes the Polarizer of optical compensating layer according to the preferred embodiment of the present invention;
Fig. 3 is the schematic cross-section that is used for the display panels of liquid crystal indicator according to the preferred embodiment of the present invention.
(detailed description of main elements)
10 dispose the Polarizer of optical compensating layer
11 polaroids
12 first optical compensating layers
13 second optical compensating layers
14 the 3rd optical compensating layers
20 liquid crystal cells
100 liquid crystal panels
Embodiment
(definition of term and symbol)
The definition of term and symbol in the instructions of the present invention is hereinafter described.
(1) symbol " nx " refers to the refractive index in the direction (that is, slow-axis direction) that refractive index in the largest face is provided, and symbol " ny " refers in same plane perpendicular to the refractive index in the direction (that is quick shaft direction) of slow axis.Symbol " nz " refers to the refractive index of thickness direction.And for example expression formula " nx=ny " not only refers to the situation that nx and ny equate fully, also comprises the situation that nx and ny equate substantially.In instructions of the present invention, phrase " equal substantially " comprises in actual applications, in the scope that the whole polarization property to the Polarizer that disposes optical compensating layer does not exert an influence, and the unequal situation of nx and ny.
(2) term " phase differential Re in the face " refers under 23 ℃, uses wavelength to be phase difference value in the face of the film (layer) of the light measurement of 590nm.Re can determine from formula Re=(nx-ny) * d, and here nx and ny represent the refractive index of the film (layer) of slow-axis direction and quick shaft direction under the wavelength of 590nm, the thickness of d (nm) expression film (layer) respectively.
(3) term " the phase differential Rth of thickness direction " refers under 23 ℃, uses the phase difference value of wavelength as the thickness direction of the film (layer) of the light measurement of 590nm.Rth can determine from formula Rth=(nx-nz) * d, and here nx and nz represent the refractive index of the film (layer) of slow-axis direction and thickness direction under the wavelength of 590nm respectively, and d (nm) represents the thickness of film (layer).
(4) appended subscript " 1 " is represented first optical compensating layer behind term of describing in the instructions of the present invention or the symbol.Subscript " 2 " appended behind term of describing in the instructions of the present invention or the symbol is represented second optical compensating layer.Subscript " 3 " appended behind term of describing in the instructions of the present invention or the symbol is represented the 3rd optical compensating layer.
(5) term " λ/2 plates " refers to and has the linearly polarized photon that will have the certain vibration direction and be converted to and have with the linearly polarized photon of the perpendicular direction of vibration of the certain vibration direction of this linearly polarized photon or right-circularly polarized light is converted to the plate of the function of left circularly polarized light (or be converted to right-circularly polarized light with left circularly polarized light).Phase difference value is about 1/2 of a predetermined wavelength (being generally the visible region) in the face of the film (layer) of λ/2 plates.
(6) term " λ/4 plates " refers to and has the plate that the linearly polarized photon that will have specific wavelength is converted into circularly polarized light (or be converted into linearly polarized photon with circularly polarized light) function.Phase difference value is about 1/4 of a predetermined wavelength (being generally the visible region) in the face of the film (layer) of λ/4 plates.
(7) term " cholesteric orientation fixed bed " refers to such layer, and wherein: the molecule that forms this layer forms helical structure; The orientation of the screw axis of this helical structure is basically perpendicular to the face direction; And fixedly present such orientation state.Therefore, term " cholesteric orientation fixed bed " refers to that not only liquid-crystal compounds shows the situation of cholesteryl liquid crystal phase, but also comprises that non-liquid-crystal compounds has the situation of cholesteryl liquid crystal phase pesudo-structure.For example, " cholesteric orientation fixed bed " can form in the following manner: thereby make the liquid crystal material that shows liquid crystal phase reverse orientation with chiral reagent is cholesteric structure (helical structure); This liquid crystal material is carried out aggregation processing or the orientation (cholesteric structure) of crosslinking Treatment to fix this liquid crystal material.
(8) phrase " the selective reflecting wavelength region may the is less than or equal to 350nm " centre wavelength that refers to the selective reflecting wavelength region may is less than or equal to 350nm.For example, be that the central wavelength lambda of selective reflecting wavelength region may can be used following formulate under the situation about forming by the use liquid crystal monomer at cholesteric orientation fixed bed.
λ＝n×P
In the formula, n represents the mean refractive index of liquid crystal monomer, and the helicity (helical pitch) that P represents cholesteric orientation fixed bed (nm).Mean refractive index n (n o+ n e)/2 expression is usually in 1.45 to 1.65 scopes.n oThe ordinary refraction index of expression liquid crystal monomer, n eThe extraordinary ray refractive index of expression liquid crystal monomer.
(9) term " chiral reagent " refers to have and makes liquid crystal material (for example nematic crystal) orientation become the compound of the function of cholesteric structure.
(10) term " twisting resistance " refers to chiral reagent provides twisting resistance for liquid crystal material and makes this liquid crystal material orientation become the ability of cholesteric structure (helical structure).Usually, twisting resistance can be represented with following formula.
Twisting resistance=1/ (P * W)
As mentioned above, P represents the helicity (nm) of cholesteric orientation fixed bed.W represents the weight ratio of chiral reagent.The weight ratio W of chiral reagent can be with W=[X/ (X+Y)] * 100 represent.X represents the weight of chiral reagent, and Y represents the weight of liquid crystal material.
A. dispose the Polarizer of optical compensating layer
A-1. dispose the one-piece construction of the Polarizer of optical compensating layer
Fig. 1 is the schematic cross-section that disposes the Polarizer of optical compensating layer according to the preferred embodiment of the present invention.Fig. 2 is a decomposition diagram of having explained the optic axis of each layer that constitutes the Polarizer that disposes optical compensating layer.As shown in Figure 1, the Polarizer 10 that disposes optical compensating layer comprises polaroid 11, first optical compensating layer 12, second optical compensating layer 13 and the 3rd optical compensating layer 14 successively.Each layer of Polarizer that disposes optical compensating layer by any suitable pressure-sensitive adhesive layer or bonding agent (not shown) and lamination together.In actual applications, not forming a side of optical compensating layer at polaroid 11 can any suitable diaphragm (not shown) of lamination.And as required, diaphragm can be configured between the polaroid 11 and first optical compensating layer 12.
First optical compensating layer 12 contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2The resin of/N has the relation of nx＞ny=nz, and phase differential Re in its face 1Be 200 to 300nm.Second optical compensating layer 13 contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2The resin of/N has the relation of nx＞ny=nz, and phase differential Re in its face 2Be 90 to 160nm.The 3rd optical compensating layer 14 has the relation of nx=ny＞nz, phase differential Re in its face 3Be 0 to 20nm, and the phase differential Rth of its thickness direction 3Be 30 to 300nm.First optical compensating layer, second optical compensating layer and the 3rd optical compensating layer will be below A-2, A-3 and the A-4 part in describe in detail respectively.
In the present invention, as shown in Figure 2, first optical compensating layer 12 is to make the absorption axes A of its slow axis B and polaroid 11 form predetermined angle by lamination.Angle [alpha] is rotated 10 ° to 30 ° with respect to the absorption axes A of polaroid 11 towards counter clockwise direction, and preferred 12 ° to 27 °, more preferably 14 ° to 25 °.Second optical compensating layer 13 is to make the absorption axes A of its slow axis C and polaroid 11 form predetermined angular β by lamination.Angle beta rotates 70 ° to 95 ° with respect to the absorption axes A of polaroid 11 towards counter clockwise direction, and preferred 72 ° to 93 °, more preferably 74 ° to 92 °.The 3rd optical compensating layer 14 is to make the absorption axes A of its slow axis D and polaroid 11 form predetermined angular γ by lamination.Angle γ rotates 70 ° to 95 ° with respect to the absorption axes A of polaroid 11 towards counter clockwise direction, and preferred 72 ° to 93 °, more preferably 74 ° to 92 °.Three specific optical compensating layers can be with such certain positional relationship lamination, thereby prevents the light leak of liquid crystal indicator when black display of VA pattern (particularly reflective or semi-transmission-type VA pattern) significantly.
The gross thickness that disposes the Polarizer of optical compensating layer of the present invention is preferably 80 to 270 μ m, more preferably 110 to 270 μ m, most preferably 140 to 270 μ m.According to the present invention, the 3rd optical compensating layer (negative electrode C plate: following) is formed by the composition that contains liquid crystal monomer and chiral reagent, thus increase significantly between nx and the nz poor (nx＞＞nz).As a result, the thickness of the 3rd optical compensating layer is very little.For example, the thickness of the conventional cathode C plate by biaxial stretch-formed preparation is more than or equal to 60 μ m, but the thickness of the 3rd optical compensating layer used in the present invention is reduced to 2 μ m.As a result, the Polarizer that disposes optical compensating layer of the present invention is compared with the traditional Polarizer that disposes optical compensating layer with similar structures (that is, four-layer structure), and gross thickness is very little.As a result, the Polarizer that disposes optical compensating layer of the present invention can greatly help to reduce the thickness of image display device.
A-2. first optical compensating layer
First optical compensating layer 12 can be used as λ/2 plates.First optical compensating layer is as λ/2 plates, thereby suitably adjusting is as the phase differential of the wavelength dispersion performance (particularly phase differential departs from the wavelength coverage of λ/4) of second optical compensating layer of λ/4 plates.Phase differential Re in the face of first optical compensating layer like this 1Be 200 to 300nm, preferred 220 to 280nm, more preferably 230 arrive 270nm.The index distribution of first optical compensating layer is nx＞ny=nz.
The thickness of first optical compensating layer can be set at and make it be suitable as λ/2 plates most.That is, its thickness setting is for providing phase differential in the required face.Specifically, the thickness of preferred first optical compensating layer is 37 to 53 μ m, more preferably 40 to 50 μ m, most preferably 43 to 47 μ m.
First optical compensating layer 12 contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2The resin of/N, preferably the photoelastic coefficient absolute value of this resin is 2.0 * 10 -13To 1.1 * 10 -11m 2/ N, most preferably 1.0 * 10 -12To 1.0 * 10 -11m 2/ N.The differential contraction stress that the absolute value of photoelastic coefficient is in the above-mentioned scope hardly can be owing to heating the time causes phase differential to change.Therefore, first optical compensating layer can form by the resin that use has such photoelastic coefficient absolute value, thereby prevents the inhomogeneous demonstration that the temperature owing to obtaining image display device causes well.
The exemplary that can satisfy the resin of such photoelastic coefficient comprises cycloolefin resinoid and cellulosic resin.Preferred especially cycloolefin resinoid.The cycloolefin resinoid is the generic term of the resin for preparing as monomer polymerization by cycloolefin, and its example is included in the resin that Japanese patent laid-open 1-240517A, Japanese patent laid-open 3-14882A, Japanese patent laid-open 3-122137A etc. describe.Its object lesson comprises: the open loop of cycloolefin (being total to) polymkeric substance; The addition polymer of cycloolefin; The multipolymer of the alpha-olefin of cycloolefin and for example ethene or propylene and so on (being typically random copolymers); The graft modification product of each personal unsaturated carboxylic acid or derivatives thereof modification of above polymkeric substance; And hydride.The object lesson of cycloolefin is the norborneol vinyl monomer.
The example of norborneol vinyl monomer comprises: norborene, its alkyl substituent and/or alkylidene substituent, for example 5-methyl-2-norborene, 5-dimethyl-2-norborene, 5-ethyl-2-norborene, 5-butyl-2-norborene, 5-ethylidene-2-norborene, and the product that is replaced by the polar group of for example halogen and so on separately; Bicyclopentadiene and 2,3-dihydro bicyclopentadiene etc.; The dimethylene octahydro-naphthalene, its alkyl substituent and/or alkylidene substituent, and the product that is replaced by the polar group of for example halogen and so on separately, 6-methyl isophthalic acid for example, 4:5,8-dimethylene-1,4,4a, 5,6,7,8, the 8a-octahydro-naphthalene, 6-ethyl-1,4:5,8-dimethylene-1,4,4a, 5,6,7,8, the 8a-octahydro-naphthalene, 6-ethylidene-1,4:5,8-dimethylene-1,4,4a, 5,6,7,8, the 8a-octahydro-naphthalene, 6-chloro-1,4:5,8-dimethylene-1,4,4a, 5,6,7,8, the 8a-octahydro-naphthalene, 6-cyano group-1,4:5,8-dimethylene-1,4,4a, 5,6,7,8, the 8a-octahydro-naphthalene, 6-pyridine radicals-1,4:5,8-dimethylene-1,4,4a, 5,6,7,8,8a-octahydro-naphthalene and 6-methoxycarbonyl-1,4:5,8-dimethylene-1,4,4a, 5,6,7,8, the 8a-octahydro-naphthalene; And the tetramer of the trimer of cyclopentadiene and cyclopentadiene, for example 4,9:5,8-dimethylene-3a, 4,4a, 5,8,8a, 9,9a-octahydro-1H-benzindene (benzoindene) and 4,11:5,10:6,9-trimethylene-3a, 4,4a, 5,5a, 6,9,9a, 10,10a, 11,11a-ten dihydros-1H-encircles five anthracenes.
In the present invention, under the situation of not damaging the object of the invention, can be used in combination other open loop polymerizable cycloolefin.The object lesson of such cycloolefin comprises the compound with a reactive double bond, for example cyclopentene, cyclooctene or 5,6-dihydro cyclopentadiene.
The cycloolefin resinoid uses toluene solvant to be preferably 25,000 to 200,000 by the number-average molecular weight (Mn) of gel permeation chromatography (GPC) measurement, and more preferably 30,000 to 100,000, most preferably 40,000 to 80,000.Number-average molecular weight is in the physical strength that can provide excellent in the above-mentioned scope, good solubleness, mouldability and casting operability.
At the cycloolefin resinoid is that hydrogenation ratio is preferably more than or equals 90% under the hydrogenation of the ring-opening polymerization polymer by the norborneol vinyl monomer situation about preparing, more preferably greater than or equal 95%, most preferably more than or equal to 99%.Hydrogenation ratio is in the heat-resisting degradability that can provide excellent in the above-mentioned scope and light degradation resistance etc.
For the cycloolefin resinoid, existing commercially available various products.The object lesson of this resin comprises that the product of the product of the product that is the commodity " ZEONEX " and " ZEONOR " by name that Japanese Zeon Co., Ltd. produces, commodity " Arton " by name that JSR Corp. produces, commodity " TOPAS " by name that Ticona Co., Ltd. produces and the commodity that Mitsui Chemicals, Inc produces are called the product of " APEL ".
The cellulosic resin of any appropriate (typical, the ester of cellulose and acid) can be used as cellulosic resin.The preferred ester that forms by cellulose and fatty acid.The object lesson of such cellulosic resin comprises primary cellulose acetate (tri acetyl cellulose: TAC), cellulose two amyl acetates, cellulose tripropionate and cellulose dipropionate.Special preferred cellulose triacetate (tri acetyl cellulose: TAC), because it has low birefringence and high penetrability.In addition, multiple commercially available TAC product is arranged, so TAC is having superiority also aspect purchase and the cost.
The object lesson of TAC commercially available prod comprises: the product of the product of the commodity that Fujiphoto Industrial Co., Ltd produces " UV-50 ", " UV-80 " by name, " SH-50 ", " SH-80 ", " TD-80U ", " TD-TAC " and " UZ-TAC ", the commodity " KC series " by name that Minolta parent corporation in Konica produces and the product of the commodity " tri acetyl cellulose 80 μ m series " by name that Lonza Japan company produces.Wherein, preferred " TD-80U " is because it has excellent penetrability and permanance.Specifically, " TD-80U " has excellent adaptability for TFT type liquid crystal indicator.
First optical compensating layer 12 preferably obtains by the film that is formed by cycloolefin resinoid or cellulosic resin is stretched.Any suitable forming method can be as the method that is formed film by cycloolefin resinoid or cellulosic resin.Its object lesson comprises compression molding, transfer moudling, injection moulding, extrusion molding, blow moulding, powdered moulding, FRP method of molding and casting method.Preferred extrusion molding and casting method improve and the good film of optical homogeneity because can obtain slickness.Condition of molding can suitably be set according to the estimated performance of the composition of employed resin or type, first optical compensating layer etc.The commercial membrane product that multiple cycloolefin resinoid and cellulosic resin have been arranged, and these commercial membrane can be carried out stretch processing.
The draw ratio of film can change according to phase difference value in the expection face of first optical compensating layer and thickness, employed resin kind, employed film thickness, draft temperature etc.Specifically, preferred draw ratio is 1.75 to 2.05 times, more preferably 1.80 to 2.00 times, and most preferably 1.85 to 1.95 times.The stretching of carrying out with such draw ratio can provide first optical compensating layer with phase differential in the face that can suitably show effect of the present invention.
Draft temperature can change according to phase difference value in the expection face of first optical compensating layer and thickness, employed resin kind, employed film thickness, draw ratio etc.Specifically, preferred draft temperature is 130 to 150 ℃, more preferably 135 to 145 ℃, and most preferably 137 to 143 ℃.Can provide first optical compensating layer in the stretching that such draft temperature carries out with phase differential in the face that can suitably show effect of the present invention.
Be configured between the polaroid 11 and second optical compensating layer 13 with reference to figure 1, the first optical compensation 12.Can adopt any suitable method as the method that disposes first optical compensating layer according to purpose.Typically, the both sides of first optical compensating layer 12 all dispose the pressure-sensitive adhesive layer (not shown), and are subsequently that first optical compensating layer 12 is bonding with the polaroid 11 and second optical compensating layer 13.Fill with above-mentioned pressure-sensitive adhesive layer in gap between the layer, thereby in first optical compensating layer merges to image display device the time, prevent that the optic axis of each layer from concerning the situation of generation deviation, and prevent the infringement that the wearing and tearing owing to each interlayer cause.And, can reduce the reflection at each interface layer place, thereby the image display device with high contrast is provided.
The thickness of pressure-sensitive adhesive layer can suitably be set according to the purposes of expecting, bond strength etc.Specifically, the thickness of preferred pressure-sensitive adhesive layer be 1 μ m to 100 μ m, more preferably 5 μ m are to 50 μ m, most preferably 10 μ m are to 30 μ m.
Any suitable contact adhesive can be as the contact adhesive that forms pressure-sensitive adhesive layer.Its object lesson comprises solvent-borne type contact adhesive, nonaqueous emulsion type contact adhesive, aqueous pressure sensitive adhesive and hot melt pressure sensitive adhesive.The preferred use contained the solvent-borne type contact adhesive of acrylate copolymer as base polymer, because it can show for the suitable pressure-sensitive adhesion performance (wettability, cohesiveness and cohesive) of the polaroid and first optical compensating layer and excellent optical clarity, against weather and thermotolerance is provided.
A-3. second optical compensating layer
First optical compensating layer 13 can be used as λ/4 plates.According to the present invention, can revise by optical property as the wavelength dispersion performance of second optical compensating layer of λ/4 plates, thereby in wavelength coverage widely, show the function of circularly polarized light as first optical compensating layer of λ/2 plates.Phase differential Re in the face of second optical compensating layer like this 2Be 90 to 160nm, preferred 100 to 150nm, more preferably 110 arrive 140nm.The index distribution of second optical compensating layer 13 is nx＞ny=nz.
The thickness of second optical compensating layer can be set at and make it be suitable as λ/4 plates most.That is, its thickness setting is phase differential in the face that expection can be provided.Specifically, the thickness of preferred second optical compensating layer is 42 to 58 μ m, more preferably 45 to 55 μ m, most preferably 48 to 52 μ m.
Second optical compensating layer 13 contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2The resin of/N, preferably the photoelastic coefficient absolute value of this resin is 2.0 * 10 -13To 1.0 * 10 -11m 2/ N, most preferably 1.0 * 10 -12To 1.0 * 10 -11m 2/ N.The differential contraction stress that the photoelastic coefficient absolute value is in the above-mentioned scope hardly can be owing to heating the time causes phase differential to change.Therefore, second optical compensating layer can form by the resin that use has such photoelastic coefficient absolute value, thereby matches with the effect of first optical compensating layer, prevents the inhomogeneous demonstration that the temperature owing to obtaining image display device causes well.
The exemplary that can satisfy the resin of such photoelastic coefficient comprises cycloolefin resinoid and cellulosic resin.In above-mentioned A-2 part, describe such cycloolefin resinoid and cellulosic resin in detail.
Phase differential Re in the face of second optical compensating layer 13 2Preferably control by changing the cycloolefin resinoid described in the above-mentioned A-2 part or the draw ratio and the draft temperature of cellulosic resin.Draw ratio can change according to phase difference value in the expection face of second optical compensating layer and thickness, employed resin kind, employed film thickness, draft temperature etc.Specifically, preferred draw ratio is 1.17 to 1.47 times, more preferably 1.22 to 1.42 times, and most preferably 1.27 to 1.37 times.The stretching of carrying out with such draw ratio can provide second optical compensating layer with phase differential in the face that can suitably show effect of the present invention.
Draft temperature can change according to phase difference value in the expection face of second optical compensating layer and thickness, employed resin kind, employed film thickness, draw ratio etc.Specifically, preferred draft temperature is 130 to 150 ℃, more preferably 135 to 145 ℃, and most preferably 137 to 143 ℃.The stretching of carrying out under such draft temperature can provide second optical compensating layer with phase differential in the face that can suitably show effect of the present invention.
Be configured between first optical compensating layer 12 and the 3rd optical compensating layer 14 with reference to figure 1, the second optical compensating layer 13.Can adopt any suitable method as the method that disposes second optical compensating layer according to purpose.Typically, in first optical compensating layer, the 12 sides configuration pressure-sensitive adhesive layer (not shown) of second optical compensating layer 13, subsequently that first optical compensating layer 12 is thereon bonding.And, in the 3rd optical compensating layer 14 sides configuration bonding coat (not shown) of second optical compensating layer 13, subsequently that the 3rd optical compensating layer 14 is thereon bonding.Have at the 3rd optical compensating layer 14 under the situation of laminated structure (cholesteric orientation fixed bed/plastic membranous layer), second optical compensating layer 13 and plastic membranous layer adhere to each other by pressure-sensitive adhesive layer, and cholesteric orientation fixed bed and plastic membranous layer adhere to each other by bonding coat.In above-mentioned A-2 part, describe pressure-sensitive adhesive layer in detail.
The exemplary that is used to form the bonding agent of bonding coat comprises curing adhesive.The exemplary of curing adhesive comprises: Photocurable adhesive, for example uv-curing type bonding agent; Moisture-cured (moisture-curable) bonding agent; And hot setting adhesive.The object lesson of hot setting adhesive comprises the heat reactive resin class bonding agent that is formed by epoxy resin, isocyanate resin, polyimide resin or similar substance.The object lesson of moisture-cured bonding agent comprises isocyanate resin class moisture-cured bonding agent.Preferred moisture-cured type bonding agent (particularly isocyanate resin class moisture-cured type bonding agent).Moisture-cured type bonding agent by with airborne moisture, adherend (adherend) surface on reactive hydrogen or the like on moisture, hydroxyl or the carboxyl of absorption react and solidify.Therefore, can coating adhesive, then it is left standstill so that spontaneous curing, thereby have excellent operability.And, do not need heating when solidifying, so the 3rd optical compensating layer need not heat in lamination (bonding) process owing to moisture-cured type bonding agent.As a result, thermal shrinkage does not take place, so even under the very little situation of the 3rd optical compensation layer thickness of the present invention, can prevent from significantly to ftracture in processes such as lamination yet.In addition, after curing adhesive solidifies, under heating, can stretch or shrink hardly.Therefore, even the very little or Polarizer that obtains is used under the situation of hot conditions at the 3rd optical compensation layer thickness of the present invention, also can prevent from significantly in processes such as lamination, to ftracture.Be noted that the isocyanates resinoid is the generic term of polyisocyanate class bonding agent and urethane resin bonding agent.
For example, the commercial binder can be used as curing adhesive, perhaps can or be dispersed in the solvent with preparation gel-type resin binder solution (or dispersion liquid) multiple curing type binder resin dissolving.Under preparation solution (or dispersion liquid) situation, the ratio of gel-type resin is 10 to 80wt% of a solids content in the preferred solution, more preferably 20 to 65wt%, preferred especially 25 arrives 65wt%, most preferably 30 arrives 50wt%.According to the type of gel-type resin, can use any suitable solvent as solvent, its object lesson comprises ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene and dimethylbenzene.Such solvent can be used singly or in combination.
The coating weight of bonding agent on second optical compensating layer can suitably be set according to purpose.For example, preferred per unit area (cm 2) second optical compensating layer on coating weight be 0.3 to 3ml, more preferably 0.5 to 2ml, most preferably 1 to 2ml.After the coating, the solvent in the bonding agent evaporates by air dry or heat drying as required.The thickness of the preferred bonding coat that obtains is 0.1 to 20 μ m, more preferably 0.5 to 15 μ m, most preferably 1 to 10 μ m.The microhardness (microhardness) of preferred bonding coat is 0.1 to 0.5GPa, more preferably 0.2 arrives 0.5GPa, most preferably 0.3 arrives 0.4GPa.Known microhardness and Vickers hardness are interrelated, so microhardness can be converted into Vickers hardness.Microhardness can be calculated from depth of cup and the sunken load of pressure by using film hardness measuring instrument (for example, trade name, MH4000 or MHA-400).
A-4. the 3rd optical compensating layer
A-4-1. the one-piece construction of the 3rd optical compensating layer
The 3rd optical compensating layer 14 has the relation of nx＞ny=nz, and can serve as so-called negative electrode C plate.The 3rd optical compensating layer has such index distribution, thereby it is good birefringence-compensated that the liquid crystal layer of VA mode liquid crystal unit is had.As a result, can obtain to have the liquid crystal indicator of obvious improved viewing angle properties.As mentioned above, expression formula " nx=ny " not only refers to the situation that nx and ny equate fully, also comprises the situation that nx and ny equate substantially.Therefore, the 3rd optical compensating layer can have the interior phase differential of face and have slow axis.The interior phase differential Re of face that can serve as the 3rd optical compensating layer of negative electrode C plate in actual applications 3Be 0 to 20nm, be preferably 0 to 10nm, more preferably 0 arrive 5nm.
The phase differential Rth of the thickness direction of the 3rd optical compensating layer 14 3Be 30 to 300nm, preferred 60 to 180nm, more preferably 80 arrive 150nm, most preferably 100 arrive 120nm.Provide the thickness of the 3rd optical compensating layer of the phase differential of such thickness direction can be according to changes such as employed materials.For example, the thickness of preferred the 3rd optical compensating layer is 1 to 50 μ m, more preferably 1 to 20 μ m, most preferably 1 to 15 μ m.At the 3rd optical compensating layer is that the thickness of the 3rd optical compensating layer is preferably 1 to 10 μ m under the situation about being formed separately by cholesteric orientation fixed bed described below, and more preferably 1 to 8 μ m most preferably is 1 to 5 μ m.Such thickness is less than the thickness (for example, more than or equal to 60 μ m) by the biaxial stretch-formed negative electrode C plate that obtains, and can help very much to reduce the thickness of image display device.And the thickness of the 3rd optical compensating layer of formation is very little, thereby prevents significantly because the inhomogeneous demonstration that temperature causes.From the angle that prevents that the cholesteric orientation from getting muddled or transmissivity reduces, and from viewpoints such as selective reflecting performance, color protection, throughput rate, preferred so very little optical compensating layer of thickness.As long as can obtain above-mentioned thickness and optical property, the 3rd optical compensating layer of the present invention (negative electrode C plate) can be formed by any suitable material.The negative electrode C plate that preferably has so very little thickness is realized by using liquid crystal material to form the cholesteric orientation and this cholesteric orientation is fixed, that is, use cholesteric orientation fixed bed (be used to form the material of cholesteric orientation and the fixing method of this cholesteric orientation is described in more detail below).
Preferred the 3rd optical compensating layer 14 is formed by the cholesteric orientation fixed bed that the selective reflecting wavelength region may is less than or equal to 350nm.More preferably the upper limit of selective reflecting wavelength region may is less than or equal to 320nm, most preferably is less than or equal to 300nm.Simultaneously, the lower limit of preferred selective reflecting wavelength region may is more than or equal to 100nm, more preferably greater than or equal 150nm.Under the situation of selective reflecting wavelength region may greater than 350nm, the selective reflecting wavelength region may covers the visible region, and therefore causes such as problem painted or decolouring.Under the situation of selective reflecting wavelength region may less than 100nm, the amount of employed chiral reagent (hereinafter describing) excessively increases, and therefore the temperature in the process that forms optical compensating layer must very accurately be controlled.As a result, almost can not produce Polarizer.
The helicity of cholesteric orientation fixed bed is preferably 0.01 to 0.25 μ m, more preferably 0.03 to 0.20 μ m, most preferably 0.05 to 0.15 μ m.For example helicity provides sufficient orientation performance more than or equal to 0.01 μ m.Helicity is less than or equal to 0.25 μ m to make and can fully suppress rotatory polarization in the shorter wavelength side of visible light, thereby fully prevents light leak.Helicity can be controlled by type (twisting resistance) and the consumption of regulating following chiral reagent.Can the adjustable screw degree, thus the selective reflecting wavelength region may is controlled in the desired extent.
Perhaps, the 3rd optical compensating layer 14 can have laminated structure, and above-mentioned laminated structure comprises that cholesteric orientation fixed bed is less than or equal to 2 * 10 with having nx＞ny=nz relation and containing photoelastic coefficient -11m 2The layer of the resin of/N (in instructions of the present invention, being also referred to as plastic foil).The exemplary that can form the material (can satisfy the resin of such photoelastic coefficient) of plastic membranous layer comprises cycloolefin resinoid and cellulosic resin.Cycloolefin resinoid and cellulosic resin are partly described in detail at A-2 above.Cellulosic resin film (typical, the TAC film) is the film with nx＞ny=nz relation.
A-4-2. form the liquid-crystal composition of the 3rd optical compensating layer (cholesteric orientation fixed bed): liquid crystal material
The 3rd optical compensating layer (cholesteric orientation fixed bed) can be formed by liquid-crystal composition.Any suitable liquid crystal material can be used as the contained liquid crystal material of said composition.Preferred this liquid crystal material (nematic crystal) has nematic liquid crystal phase.The example of operable such liquid crystal material comprises liquid crystal polymer and liquid crystal monomer.This liquid crystal material can cause or the thermic mechanism table reveals liquid crystal liquid crystal property by molten.In addition, preferably the orientation state of this liquid crystal is even orientation.The content of liquid crystal material is preferably 75 to 95wt% in the liquid-crystal composition, more preferably 80 arrives 90wt%.Under the situation of content less than 75wt% of liquid crystal material, said composition can't fully show liquid crystal state, therefore can't fully form the cholesteric orientation.Under the situation of content greater than 95wt% of liquid crystal material, the content of chiral reagent reduces, and reverses thereby can't give fully, therefore can't fully form the cholesteric orientation.
Preferred liquid crystal material is liquid crystal monomer (for example polymerizable monomer or a cross-linkable monomer), because the polymerization that the orientation state of liquid crystal monomer can be by following liquid crystal monomer or crosslinked and fixing.For example, the orientation state can make the polymerization or crosslinked and fixing each other of this liquid crystal monomer subsequently by making the liquid crystal monomer orientation.As a result, polymkeric substance forms by polymerization, and tridimensional network is by being cross-linked to form.Polymkeric substance and tridimensional network are not to be exactly liquid crystal.Therefore, the 3rd optical compensating layer of Xing Chenging can not change for example liquid crystal phase, glassy phase or crystallization phase mutually owing to temperature change into thus, especially for liquid-crystal compounds.As a result, the 3rd optical compensating layer will not be acted upon by temperature changes, and can form the optical compensating layer with excellent stability.
Any suitable liquid crystal monomer can be used as liquid crystal monomer.For example, use described polymerizable liquid crystal former (mesogen) compounds such as JP2002-533742A (WO00/37585), EP358208 (US5211877), EP (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171, GB2280445 etc.The object lesson of the former compound of polymerizable liquid crystal comprises: buy from the LC242 of BASF AG (trade name), buy from the E7 of Merck company (trade name) and buy from the LC-Silicone-CC3767 of Wacker-Chemie company (trade name).
For example, preferred nematic crystal monomer is as liquid crystal monomer, and its object lesson comprises the represented monomer of following formula (1).Liquid crystal monomer can use separately, and perhaps two or more are used in combination.
[chem.1]
Figure A20058000171800191
In following formula (1), A 1And A 2Represent polymerizable group separately, and can be same to each other or different to each other.A 1And A 2In one can represent hydrogen.Each X all represent independently singly-bound ,-O-,-S-,-C=N-,-O-CO-,-CO-O-,-O-CO-O-,-CO-NR-,-NR-CO-,-NR-,-O-CO-NR-,-NR-CO-O-,-CH 2-O-or-NR-CO-NR-.R represents hydrogen or has the alkyl of 1 to 4 carbon atom.M represents mesogenic group.
In following formula (1), a plurality of X can be same to each other or different to each other, but preferably identical.
In the represented monomer of following formula (1), preferred each A 2All be configured in A 1The ortho position.
Preferred A 1And A 2All use following formula (2) expression independently, preferred A 1And A 2Represent identical group.
Z-X-(Sp) n ...(2)
In following formula (2), Z represents crosslinkable groups, and X is identical with the definition of following formula (1).Sp represents the interval base (spacer) that the straight or branched alkyl by replacement with 1 to 30 carbon atom or non-replacement constitutes.N represents 0 or 1.Carbochain among the Sp can be inserted (interrupt) by sulphur, non-conterminous imido grpup in the oxygen in the ether functional group, the thioether functional group, alkyl imido grpup etc. with 1 to 4 carbon atom.
In following formula (2), preferred Z represents any one represented functional group in the following formula.In following formula, the example of R comprises methyl, ethyl, n-pro-pyl, isopropyl, normal-butyl, isobutyl and the tert-butyl group.
[chem.2]
Figure A20058000171800192
In following formula (2), preferred Sp represents structural unit shown in any one in the following formula.In following formula, preferred m represents 1 to 3, and preferred p represents 1 to 12.
[chem.3]
-(CH 2) p-.-(CH 2CH 2O) mCH 2CH 2-.-CH 2CH 2SCH 2CH 2-，-CH 2CH 2NHCH 2CH 2-.
In following formula (1), preferred M represents with following formula (3).In following formula (3), X is defined identical with following formula (1).For example, Q represents to replace or the straight or branched alkyl or the aryl radical of non-replacement.For example, Q represents to have the straight or branched alkylidene of the replacement or the non-replacement of 1 to 12 carbon atom.
Figure A20058000171800202
Represent at Q under the situation of aryl radical that preferred Q represents the aryl radical shown in any one or its replacement analog in the following formula.
[chem.5]
The replacement analog of the aryl radical that following formula is represented can have 1 to 4 substituting group separately on each aromatic rings, perhaps each aromatic rings or base have 1 to 2 substituting group.A plurality of substituting groups can be mutually the same or different.Substituent example comprises: the alkyl with 1 to 4 carbon atom; Nitro; Halogen, for example fluorine, chlorine, bromine or iodine; Phenyl; And alkoxy with 1 to 4 carbon atom.
The object lesson of liquid crystal monomer comprises the monomer with following formula (4) to (19) expression.
[chem 6]
Figure A20058000171800211
The temperature range that liquid crystal monomer demonstrates liquid crystal liquid crystal property changes according to the type of liquid crystal monomer.More particularly, preferred range is 40 to 120 °, more preferably 50 to 100 °, and most preferably 60 to 90 °.
A-4-3. form the liquid-crystal composition of the 3rd optical compensating layer (cholesteric orientation fixed bed): chiral reagent
The liquid-crystal composition that preferably can form the 3rd optical compensating layer (cholesteric orientation fixed bed) contains chiral reagent.The content of chiral reagent is 5 to 23wt% in the preferred liquid-crystal composition, more preferably 10 arrives 20wt%.Under the situation of content less than 5wt% of chiral reagent, can not provide fully and reverse, therefore can not fully form the cholesteric orientation.As a result, almost the selective reflecting wavelength region may of obtaining optical compensating layer can not be controlled at expected areas (shorter wavelength side).Under the situation of content greater than 23wt% of chiral reagent, liquid crystal material shows liquid crystal state in very narrow temperature range, and therefore temperature must very accurately be controlled in the process that forms optical compensating layer.As a result, the production for Polarizer brings difficulty.Such chiral reagent can be used singly or in combination.
Chiral reagent can adopt any suitable material that the liquid crystal material orientation can be become the cholesteric structure of expection.For example, the twisting resistance of preferred such chiral reagent is more than or equal to 1 * 10 -6Nm -1(wt%) -1, more preferably 1 * 10 -5Nm -1(wt%) -1To 1 * 10 -2Nm -1(wt%) -1, most preferably 1 * 10 -4Nm -1(wt%) -1To 1 * 10 -3Nm -1(wt%) -1Can use chiral reagent, thereby the helicity of cholesteric orientation fixed bed is controlled in the desired extent, and the selective reflecting wavelength region may is controlled in the desired extent with such twisting resistance.For example, have in use under the situation of chiral reagent of identical twisting resistance, when chiral reagent content was big in the liquid-crystal composition, the selective reflecting wavelength region may of the optical compensating layer that is provided was in the shorter wavelength side.For example, under the situation that the chiral reagent content in liquid-crystal composition equates, the selective reflecting wavelength region may with optical compensating layer that the chiral reagent of big twisting resistance provides is in the shorter wavelength side.Its object lesson is described hereinafter.For example, for the selective reflecting wavelength region may with formed optical compensating layer is set in 200 in the scope of 220nm, it is 5 * 10 that liquid-crystal composition can contain 11 to 13wt% twisting resistance -4Nm -1(wt%) -1Chiral reagent.For example, for the selective reflecting wavelength region may with formed optical compensating layer is set in 290 in the scope of 310nm, it is 5 * 10 that liquid-crystal composition can contain 7 to 9wt% twisting resistance -4Nm -1(wt%) -1Chiral reagent.
Preferred chiral reagent is a polymerizable chiral reagent.The object lesson of polymerizable chiral reagent comprises that following general formula (20) is to (23) represented chipal compounds.
(Z-X 5) nCh…(20)
(Z-X 2-Sp-X 5) nCh…(21)
(P 1-X 5) nCh…(22)
(Z-X 2-Sp-X 3-M-X 4) nCh…(23)
In (23), Z is defined consistent with said structure formula (2) with Sp in formula (20).X 2, X 3And X 4Represent independently of one another chemical single bond ,-O-,-S-,-O-CO-,-O-CO-O-,-CO-NR-,-NR-CO-,-O-CO-NR-,-NR-CO-O-or-NR-CO-NR-.R represents H or has the alkyl of 1 to 4 carbon atom.X 5The expression chemical single bond ,-O-,-S-,-O-CO-,-O-CO-O-,-CO-NR-,-NR-CO-,-O-CO-NR-,-NR-CO-O-,-NR-CO-NR-,-CH 2O-,-O-CH 2-,-CH=N-,-N=CH-or-N ≡ N-.As mentioned above, R represents H or has the alkyl of 1 to 4 carbon atom.As mentioned above, M represents liquid crystal person's group.P 1Expression hydrogen, have the alkyl of 1 to 30 carbon atom, the naphthenic base that has the acyl group of 1 to 30 carbon atom or have 3 to 8 carbon atoms and replaced by 1 to 3 alkyl with 1 to 6 carbon atom.N represents 1 to 6 integer.Ch represents that quantivalency is the chirality base of n.In formula (23), preferred X at least 3And X 4In an expression-O-CO-O-,-O-CO-NR-,-NR-CO-O-,-NR-CO-NR-.In formula (22), at P 1Under the situation of expression alkyl, acyl group, naphthenic base, its carbochain can or have the insertions such as imido grpup alkyl of 1 to 4 carbon atom by sulphur, non-conterminous imido grpup in the oxygen in the ether functional group, the thioether functional group.
The example of the chirality base that Ch represents comprises the atomic group shown in the following formula.
[chem7]
[chem8]
Figure A20058000171800241
In above-mentioned atomic group, L represent to have 1 to 4 carbon atom alkyl, have alkoxy, halogen, COOR, OCOR, CONHR or the NHCOR of 1 to 4 carbon atom.R represents to have the alkyl of 1 to 4 carbon atom.The end that is noted that the atomic group shown in the following formula is represented to connect (binding hand) with the key of adjacent group separately.
In the atomic group, the atomic group that preferred especially following formula is represented.
[chem9]
In the preferred example of the chipal compounds of following formula (21) or (23) expression: n represents 2; Z represents H 2C=CH-; Ch represents represented atomic group down.
[chem10]
Figure A20058000171800251
The object lesson of chipal compounds comprises that following formula (24) is to (44) represented compound.Notice that the twisting resistance of these chipal compounds is all more than or equal to 1 * 10 -6Nm -1(wt%) -1
[chem11]
Figure A20058000171800252
[chem12]
Except the chipal compounds of above-mentioned expression, the further example of chipal compounds comprises the chipal compounds of describing among RE-A4342280, DE19520660.6 and the DE19520704.1.
Note, can adopt any suitable liquid crystal material and the combination of chiral reagent according to purpose.The typical especially example of this combination comprises: the combination of the chiral reagent that the represented liquid crystal monomer/following formula (38) of following formula (10) is represented; And the combination of the represented chiral reagent of the represented liquid crystal monomer/following formula (39) of following formula (11).
A-4-4. form the liquid-crystal composition of the 3rd optical compensating layer (cholesteric orientation fixed bed): other adjuvant
The liquid-crystal composition that can form the 3rd optical compensating layer (cholesteric orientation fixed bed) preferably contains at least a in polymerization initiator and the crosslinking chemical (hardening agent).Use polymerization initiator and/or crosslinking chemical (hardening agent), thereby effectively make cholesteric structure (cholesteric orientation) fixing with the morphogenetic liquid crystal material of liquid crystal.As long as can obtain effect of the present invention, any suitable material can be used as polymerization initiator or crosslinking chemical.The example of polymerization initiator comprises benzoyl peroxide (BPO) and azoisobutyronitrile (AIBN).The example of crosslinking chemical (hardening agent) comprises ultra-violet curing agent, light curing agent and thermal curing agents.Its object lesson comprises isocyanate class crosslinking chemical, epoxies crosslinking chemical and metallo-chelate crosslinking chemical.Such polymerization initiator or crosslinking chemical may be used singly or in combin.Polymerization initiator or the crosslinking chemical content in liquid-crystal composition is preferably 0.1 to 10wt%, more preferably 0.5 arrives 8wt%, most preferably 1 arrives 5wt%.Under the situation of content less than 0.1wt% of polymerization initiator or crosslinking chemical, the cholesteric structure can not be fully fixing.Under the situation of content greater than 10wt% of polymerization initiator or crosslinking chemical, liquid crystal material shows liquid crystal state in very narrow temperature range, and the control of the temperature in the process that forms optical compensating layer relates to a lot of difficulties.
Liquid-crystal composition can further contain any suitable adjuvant as required.The example of adjuvant comprises antioxidant, modifier, surfactant, dyestuff, pigment, inhibitor and ultraviolet absorber fade.These adjuvants may be used singly or in combin.More particularly, examples of antioxidants comprises phenol compound, aminated compounds, organic sulfur compounds and phosphorus hydrogen type compound.The example of modifier comprises glycols, polysiloxane and alcohols.For example, add surfactant so that the optical compensation laminar surface becomes smooth.The example of operable surfactant comprises polysiloxane-based surfactant, acrylic acid surfactant and fluorine class surfactant, preferred especially polysiloxane-based surfactant.
A-4-5. form the method for the 3rd optical compensating layer (cholesteric orientation fixed bed)
Can adopt any suitable method to be used to form the method for the 3rd optical compensating layer (cholesteric orientation fixed bed), as long as the cholesteric orientation fixed bed that can obtain to expect.The typical method that forms the 3rd optical compensating layer (cholesteric orientation fixed bed) comprises: liquid-crystal composition is coated on the substrate to form coating layer; Coating layer is heat-treated, make that the liquid crystal material orientation in the liquid-crystal composition becomes the cholesteric orientation; Thereby this coating layer is carried out the orientation of at least a fixedly liquid crystal material in aggregation processing and the crosslinking Treatment; And the cholesteric orientation fixed bed that will form on substrate shifts.The detailed process of the method that forms the 3rd optical compensating layer hereinafter will be described.
At first, with liquid crystal material, chiral reagent, polymerization initiator or crosslinking chemical and the dissolving of various adjuvants as required or be dispersed in the solvent with preparation liquid crystal coating fluid.Liquid crystal material, chiral reagent, polymerization initiator, crosslinking chemical and adjuvant are as mentioned above.The solvent that is used for the liquid crystal coating fluid has no particular limits.Its object lesson comprises: halogenated hydrocarbon, for example chloroform, methylene chloride, phenixin, ethylene dichloride, tetrachloroethane, carrene, triclene, zellon, chlorobenzene and o-dichlorobenzene; Phenols, for example phenol, parachlorphenol, orthomonochlorphenol, metacresol, orthoresol and paracresol; Arene, for example benzene,toluene,xylene, mesitylene, methoxybenzene and 1,2-dimethoxy benzene; Ketones solvent, for example acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, cyclopentanone, 2-Pyrrolidone and N-N-methyl-2-2-pyrrolidone N-; Esters solvent, for example ethyl acetate and butyl acetate; Alcohols solvent, for example tert-butyl alcohol, glycerine, ethylene glycol, triethylene glycol, glycol monoethyl ether, diethylene glycol dimethyl ether, propylene glycol, dipropylene glycol and 2-methyl-2,4-pentanediol; Amide solvent, for example dimethyl formamide and dimethyl acetamide; Nitrile solvents, for example acetonitrile and butyronitrile; Ether solvent, for example diethyl ether, butyl oxide, tetrahydrofuran and dioxane; Carbon disulphide; Ethyl cellulose solvent and butyl cellulose solvent.Wherein, preferred toluene, dimethylbenzene, mesitylene, MEK, methyl isobutyl ketone, cyclohexanone, ethyl cellulose solvent, butyl cellulose solvent, ethyl acetate, butyl acetate, propyl acetate and ethyl cellulose solvent acetate (ethyl cellosolveacetate).These solvents can be used singly or in combination.
The viscosity of liquid crystal coating fluid changes according to the content or the temperature of liquid crystal material.For example, being approximately room temperature (20 to 30 ℃) and the concentration of liquid crystal material in the liquid crystal coating fluid in temperature is 5 under the situation of 70wt%, and the viscosity of preferred coating fluid is 0.2 to 20mPas, more preferably 0.5 to 15mPas, most preferably 1 to 10mPas.More particularly, be under the situation of 30wt% in the concentration of liquid crystal material in the liquid crystal coating fluid, the viscosity of preferred coating fluid is 2 to 5mPas, more preferably 3 arrives 4mPas.The viscosity of coating fluid can prevent to drip owing to the liquid that this coating fluid of coating produces more than or equal to 0.2mPas well.In addition, the viscosity of coating fluid is less than or equal to 20mPas can provide and have very excellent surface flatness, do not have optical compensating layer in uneven thickness and that coating performance is excellent.
Subsequently, this liquid crystal coating fluid is applied on the substrate to form coating layer.The method that forms this coating layer can adopt any suitable method (typical, the method for this coating fluid of coating that flows).Its object lesson comprises that rolling method, spin-coating method, rod are coated with method (wire bar coating method), dip coating, extrusion molding, curtain and are coated with method (curtain coating method) and spraying process.Wherein, from the viewpoint of coating efficiency, preferred spin-coating method and extrusion molding.
Can suitably determine the coating weight of coating fluid according to the concentration of coating fluid, the thickness of destination layer etc.For example, the concentration of liquid crystal material is under the situation of 20wt% in coating fluid, preferred unit area (100cm 2) coating weight of substrate is 0.03 to 0.17ml, more preferably 0.05 to 0.15ml, most preferably 0.08 to 0.12ml.
Can make any suitable substrate of liquid crystal material orientation can be used as substrate.Typically, substrate comprises various plastic foils.The object lesson of plastics comprises: for example, and cellulose family plastics (for example tri acetyl cellulose (TAC)), polyolefin (for example tygon, polypropylene or poly-(4-methylpentene-1)), polyimide; Polyamidoimide, polyetherimide, polyamide, polyetheretherketone, polyetherketone, polyketone thioether, polyethersulfone, polysulfones, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, Polyethylene Naphthalate, polyacetal, polycarbonate, polyarylate, acryl resin, polyvinyl alcohol (PVA), polypropylene, epoxy resin and phenolics.In addition, for example, can also use the substrate that is placed with above-mentioned plastic foil or sheet on for example by the substrate of making such as aluminium, copper or iron, the substrate of making by pottery or the substrate made by glass.And, also can use by on the surface of plastic foil or sheet, forming the substrate that SiO2 oblique evaporation film (oblique evaporation film) obtains.The thickness of preferable substrate be 5 μ m to 500 μ m, more preferably 10 μ m are to 200 μ m, most preferably 15 μ m are to 150 μ m.Such thickness can provide enough intensity for substrate, and can prevent to produce the problem that for example ruptures aborning thus.
Subsequently, coating layer is heat-treated, thereby make the liquid crystal material orientation that shows as the liquid crystal phase state.Contain chiral reagent and liquid crystal material in the coating layer simultaneously, so liquid crystal material reverses and orientation showing as to be endowed under the state of liquid crystal phase.As a result, coating layer (forming the liquid crystal material of coating layer) forms cholesteric structure (helical structure).
Heat treated temperature conditions can suitably be set (specifically, being the temperature that liquid crystal material demonstrates liquid crystal liquid crystal property) according to liquid crystal material.More particularly, preferred heating-up temperature is 40 to 120 ℃, more preferably 50 to 100 ℃, and most preferably 60 to 90 ℃.Heating-up temperature is greater than or equal to 40 ℃ can make the abundant orientation of liquid crystal material usually.If heating-up temperature is less than or equal to 120 ℃, for example ought considers that the range of choice of stable on heating situation substrate is bigger, thereby can select best substrate according to liquid crystal material.And preferred heat time heating time is more than or equal to 30 seconds, more preferably greater than or equal 1 minute, be preferably greater than especially or equal 2 minutes, most preferably more than or equal to 4 minutes.The processing time less than 30 seconds situation under, liquid crystal material can not fully show liquid crystal state.And be less than or equal to 10 minutes preferred heat time heating time, is more preferably less than or equals 8 minutes, most preferably is less than or equal to 7 minutes.The processing time greater than 10 minutes situation under, adjuvant may distil.
Subsequently, the coating layer that contains the liquid crystal material that shows the cholesteric structure is carried out at least a in aggregation processing and the crosslinking Treatment, so that the orientation of liquid crystal material (cholesteric structure) is fixing.Specifically, carry out aggregation processing, thereby make liquid crystal material (polymerization single polymerization monomer) and/or chiral reagent (polymerizable chiral reagent) polymerization, and to make polymerization single polymerization monomer and/or polymerizable chiral immobilization of reagents be the repetitive of polymer molecule.In addition, carry out crosslinking Treatment, thereby form the tridimensional network of liquid crystal material (cross-linking monomer) and/or chiral reagent, and make this cross-linking monomer and/or chiral reagent fixedly become the part of cross-linked structure.As a result, the orientation state of liquid crystal material is fixed.Be noted that by the polymerization of liquid crystal monomer or the polymkeric substance that is cross-linked to form or three-dimensional structure and be " non-liquid crystal liquid crystal property ".The 3rd optical compensating layer of Xing Chenging for example can not change liquid crystal phase, glassy phase or crystallization phase into because of the peculiar temperature change of liquid-crystal compounds thus, therefore orientation can not take place change.As a result, the 3rd optical compensating layer that forms thus can be as the high-performance optics layer of compensation that not influenced by temperature change.The selective reflecting wavelength coverage of the 3rd optical compensating layer is optimised at 100nm in the 320nm scope, can suppress phenomenons such as light leak thus significantly.
Can come the concrete steps of suitable selective polymerization processing or crosslinking Treatment according to the type of employed polymerization initiator or crosslinking chemical.For example, Photoepolymerizationinitiater initiater or photocrosslinking agent can be used for rayed, and thermal polymerization or thermal cross-linking agent can be used for heating.The irradiation time of light or ultraviolet light, exposure intensity, total exposure etc. can suitably be set according to the type of liquid crystal material, the type of substrate, the expection character of the 3rd optical compensating layer etc.Equally, can suitably set heating-up temperature, heat time heating time etc. according to purpose.
The cholesteric orientation fixed bed that forms on substrate as mentioned above is transferred to the second optical compensation laminar surface to form the 3rd optical compensating layer.Have at the 3rd optical compensating layer under the situation of laminated structure of cholesteric orientation fixed bed and plastic membranous layer, plastic foil can adhere on second optical compensating layer by pressure-sensitive adhesive layer, and cholesteric orientation fixed bed can be transferred on the plastic layer, thereby forms the 3rd optical compensating layer.Perhaps, plastic foil can adhere on the cholesteric orientation fixed bed that forms on the substrate by bonding coat and form laminate, and this laminate can adhere to the surface of second optical compensating layer by pressure-sensitive adhesive layer.Transfer step further comprises to be peeled off substrate from the 3rd optical compensating layer.The curing adhesive such as the above-mentioned A-3 that are used for bonding coat partly describe.Plastic membranous layer such as above-mentioned A-4 partly describe.
The exemplary of the method for above-mentioned formation the 3rd optical compensating layer adopts liquid crystal monomer (polymerization single polymerization monomer or cross-linking monomer, for example) as liquid crystal material, but the method that forms the 3rd optical compensating layer of the present invention is not restricted to this method, but can be the method that adopts this liquid crystal polymer.But preferably this method adopts above-mentioned liquid crystal monomer.Use this liquid crystal monomer, thereby form optical compensating layer with excellent optical compensation function and thickness minimizing.Specifically, use liquid crystal monomer to help to control the selective reflecting wavelength region may.In addition, the viscosity of coating fluid etc. can easily be set by using this liquid crystal monomer, thereby promotes to form the 3rd extremely thin optical compensating layer.In addition, liquid crystal monomer has excellent handling property.In addition, the optical compensating layer that is obtained even have better surface flatness.
A-5. polaroid
According to purpose, can adopt any suitable polaroid as polaroid 11.Its example comprises: by adsorbing the dichroic substance of iodine for example or dichroic dye on the hydrophilic polymer film that makes for example polyvinyl alcohol film, the formalized polyvinyl alcohol film of part or the partly-hydrolysed film of ethylene/vinyl acetate copolymer class and so on, and this film carried out uniaxial tension and the film for preparing; And the polyalkenes alignment film etc. of the dehydration product of polyvinyl alcohol film or dechlorination product of polyvinyl chloride film and so on for example.Wherein, the especially preferred dichroic substance by adsorbing iodine for example on the polyvinyl alcohol film and this film carried out the polaroid that uniaxial tension prepares is because it has higher polarisation dichroic ratio.The thickness of polaroid is not particularly limited, but is typically about 1 to 80 μ m.
By absorption iodine on the polyvinyl alcohol film and this film is carried out the polaroid that uniaxial tension prepares followingly to produce, for example: the polyvinyl alcohol film is immersed the aqueous solution of iodine to dye; And this film is stretched to 3 to 7 times of original length.Aqueous solution can contain boric acid, zinc sulfate, zinc chloride etc. as required, and perhaps the polyvinyl alcohol film can immerse in the aqueous solution of potassium iodide etc.And, the polyvinyl alcohol film can be soaked in water and cleans as required.
Water cleans the polyvinyl alcohol film not only can remove the dirt or the flush away detackifier on striping surface, can also expand to prevent the non-uniform phenomenon of uneven dyeing for example etc. by making the polyvinyl alcohol film.Can be after the process that film is dyeed with iodine, among or before this film is stretched.Stretching can be carried out in the aqueous solution of boric acid or potassium iodide or in the water-bath.
A-6. diaphragm
Can be used as diaphragm as any suitable diaphragm of polaroid protective seam.The object lesson that is used as the material of this film principal ingredient comprises transparent resin, for example cellulosic resin (for example tri acetyl cellulose (TAC)), polyester resin, polyvinyl alcohol resin, polycarbonate resin, polyamide-based resin, polyimide based resin, polyether sulfone resin, polysulfones resin, polystyrene resins, polynorbornene resinoid, polyolefin resin, acryl resin and cellulose acetate resinoid.Its other example comprises acrylic compounds, urethanes class, urethane acrylate class, epoxies or silicones class thermoset resin or uv-curing type resin.Its further example comprises glassy polymers, for example the type siloxane polymkeric substance.In addition, also can use the polymer film of describing among the JP2001-343529A (WO 01/37007).More particularly, the film of this publication in open is to replace or the thermoplastic resin of the imide of non-replacement and having on side chain replaces or the resin combination of the thermoplastic resin of the phenyl of non-replacement is constituted by containing having on the side chain.Its object lesson comprises the resin combination that contains isobutylene and N-methyl maleimide alternating copolymer and vinyl cyanide/styrol copolymer.For example, polymer film can be the extruded product of above-mentioned resin combination.Wherein, preferred TAC, polyimide based resin, polyvinyl alcohol resin and glassy polymers.Preferred especially TAC.
Preferred diaphragm is transparent and do not have a color.More particularly, the thickness direction phase differential of preferred diaphragm be-90nm is to+90nm, more preferably-80nm is to+80nm, and most preferably-70nm arrives+70nm.
As long as can access the phase differential of preferred thickness direction, diaphragm can have any suitable thickness.More particularly, the thickness of preferred diaphragm is less than or equal to 5mm, is more preferably less than or equals 1mm, preferred especially 1 to 500 μ m, most preferably 5 to 150 μ m.
The surface opposite side of optical compensating layer (that is, with respect to) that is configured in the diaphragm in polaroid 11 outsides can be carried out dura mater processing, anti-reflex treated, release treatment, non-glare treated etc. as required.
A-7. dispose other composition of the Polarizer of optical compensating layer
The Polarizer that disposes optical compensating layer of the present invention may further include other optical layers.According to the type of purpose or image display, can adopt any suitable optical layers as other optical layers.The object lesson of other optical layers comprises liquid crystal film, light-diffusing films, diffraction film and other optical compensating layer (phase retardation film).
The Polarizer that disposes optical compensating layer of the present invention can comprise further at least one side that adhesive layer (sticking layer) is as outermost layer.Comprise that adhesive layer makes the lamination of Polarizer and miscellaneous part (for example liquid crystal cell) become easily as outermost layer, thereby can prevent that Polarizer from stripping down from miscellaneous part.Any suitable material can be as the material of adhesive layer.The object lesson of this material comprises the described contact adhesive of A-2 part.Consider prevention because the foaming that causes of moisture absorption or the degeneration of peeling off situation, optical property and because the problems such as liquid crystal cell distortion that the difference of thermal expansion causes, preferably use has good moisture resistance and stable on heating material.
When reality was used, when reality was used this Polarizer, the surface coverage of adhesive layer had suitable spacer, thereby can prevent to pollute.Spacer can be for example polysiloxane-based by using, chain alkyl class, fluorine class or molybdenum sulfide separating agent provide on any suitable film and separate coating (releasing coating) and form.
Each layer of Polarizer of the present invention can have uv absorption property by handling with ultraviolet absorbers such as for example salicylic acid compounds, benzophenone compound, benzotriazole compound, acrylonitrile compound or nickel complex salt compounds.
B. produce the method for Polarizer
The Polarizer that disposes optical compensating layer can carry out lamination to above-mentioned layer by above-mentioned bonding coat or pressure-sensitive adhesive layer and produce.Can adopt any suitable lamination method, as long as the formed angle of optic axis (α, β and γ angle) of each layer is in above-mentioned scope.For example, polaroid, first optical compensating layer, second optical compensating layer and the 3rd optical compensating layer can strike out predetermined size, and make its orientation for forming above-mentioned α, β and γ angle, carry out lamination by bonding agent or contact adhesive then.
C. the use of Polarizer
The Polarizer that disposes optical compensating layer of the present invention can suitably be used for various image displays (for example LCD and self luminous display).Can use the object lesson of the image display of this Polarizer that disposes optical compensating layer to comprise LCD, EL display, plasma scope (PD) and field-emitter display (FFD).For example, the Polarizer that disposes optical compensating layer of the present invention that is used for LCD is useful to viewing angle compensation.The Polarizer that disposes optical compensating layer of the present invention can be used for the LCD of circular polarisation mode, particularly to switch (IPS) LCD in the TN LCD of even orientation, the face and vertical orientation (VA) LCD useful.For example, be used for the Polarizer of optical compensating layer that disposes of the present invention of EL display for preventing the electrode reflection effectively.
D. image display device
Liquid crystal indicator is described as the example of image display device of the present invention.The liquid crystal panel that is used for liquid crystal indicator has also been described.Other structure of liquid crystal indicator can adopt any suitable structure according to purpose.In the present invention, the liquid crystal indicator of preferred VA pattern, the liquid crystal indicator of preferred reflective especially or semi-transmission-type VA pattern.Fig. 3 is the schematic cross-section of liquid crystal panel according to the preferred embodiment of the present invention.The liquid crystal panel that is used for liquid crystal indicator is described with reference to figure 3.Liquid crystal panel 100 disposes: liquid crystal cells 20; Be configured in the polarizer 30 of liquid crystal cells 20 upsides; With the Polarizer 10 that is configured in polarizer 30 upsides.According to the alignment mode of purpose and liquid crystal cells, any suitable polarizer can be used as polarizer 30.According to the alignment mode of purpose and liquid crystal cell, polarizer 30 can adopt any suitable polarizer.According to the alignment mode of purpose and liquid crystal cells, polarizer 30 can omit.Polarizer 10 refers to the Polarizer that disposes above-mentioned A and the described optical compensating layer of the present invention of B part.Liquid crystal cells 20 comprises: a pair of glass substrate 21 and 21 '; And be configured in liquid crystal layer 22 between the substrate as display medium.Reflecting electrode 23 is configured on the liquid crystal layer side of infrabasal plate 21 ', and the colored filter (not shown) is configured on the upper substrate 21.Distance between substrate 21 and 21 ' (cell gap) is by spacer 24 controls.
For example, in the liquid crystal indicator 100 of reflective VA pattern, do not applying under the voltage condition, liquid crystal molecule is perpendicular to substrate 21 and 21 ' orientation.This vertical orientation is to dispose between the substrate that is formed with the homeotropic alignment layer (not shown) thereon separately by the nematic crystal that will have negative dielectric anisotropic to form.In this state, inject liquid crystal layer 22 if make by the linearly polarized photon of Polarizer 10 from the surface of upper substrate 21, then incident light just will advance along the long axis of liquid crystal molecule direction of vertical orientation.Birefringence does not take place in the long axis direction at liquid crystal molecule, so incident light advances under the situation that does not change the polarization direction.Liquid crystal cells 22 is passed in light electrode 23 reflection that is reflected, and penetrates from upper substrate 21 subsequently.It is identical with incident light to penetrate polarized state of light, and penetrates light and pass Polarizer 10, thereby bright demonstration is provided.When applying voltage between electrode, the major axis of liquid crystal molecule is parallel to the substrate surface orientation.In this state, liquid crystal molecule shows birefringence with respect to the linearly polarized photon that enters liquid crystal layer 22, and the polarization of incident light state changes according to the inclination angle of liquid crystal molecule.For example, applying under the predetermined maximum voltage, thereby be reflected electrode 23 reflection and the polarisation of light direction half-twist that penetrates from upper substrate becomes linearly polarized photon, and absorbed, showing thereby provide to show slinkingly by Polarizer 10.Not applying under the voltage condition, be returned to the state of bright demonstration by the orientation restraint.Change the voltage that is applied and to control the inclination angle of liquid crystal molecule, thereby change transmission light intensity, so that classification display is provided from Polarizer 10.
Hereinafter, will be described in more detail the present invention by embodiment.But, the invention is not restricted to these embodiment.The measuring method of each performance among the embodiment is described below.
(1) measures thickness
The thickness that in embodiment and the comparing embodiment each disposes the Polarizer of optical compensating layer uses Ozaki Mfg.Co., and the Dial Gauge that Ltd produces measures.
(2) measure because the inhomogeneous demonstration that temperature causes
Each Polarizer that disposes optical compensating layer in embodiment and the comparing embodiment is adhered on the Polarizer that disposes optical compensating layer equally, thus the preparation measuring samples.This Polarizer that disposes optical compensating layer adhered to each other make separately the absorption axes of polaroid be perpendicular to one another and the 3rd optical compensating layer is toward each other separately.This measuring samples is placed on the backlight, takes the image that backlight illuminates with digital camera then.The Win Roof v3.0 GTGization (grayed) (256 grades) that the image of taking is produced with MitaniCorporation.As boundary, it is black for white and 35 to 255 grades of levels that stratification levels two is divided into 0 to 35 grade of level with the 35th grade of level of 0 to 255 gray scale level.White ratio in the image is represented with %.Measuring samples heated 10 minutes down at 85 ℃, measured before the heating and the white ratio after heating.Determine the variable quantity of white ratio, the more little demonstration of variable quantity is because the inhomogeneous demonstration that temperature causes is more little.
(3) measure transmissivity
Each Polarizer that disposes optical compensating layer in embodiment and the comparing embodiment is adhered on the Polarizer that disposes optical compensating layer equally, thus the preparation measuring samples.This Polarizer that disposes optical compensating layer adhered to each other make separately the absorption axes of polaroid be perpendicular to one another and the 3rd optical compensating layer is toward each other separately.The commodity that use Murakami Color ResearchLaboratory to make DOT-3 by name measures the transmissivity of sample.
Embodiment 1
(production polaroid)
With commercially available polyvinyl alcohol (PVA) (PVA) film (buy from Kuraray Co., Ltd.) dyeing and in borated aqueous solution in containing iodine aqueous solution, between the roller of friction speed ratio uniaxial tension to about 6 double-length degree, thereby obtain continuous polaroid.(buying from Fuji Photo Film Co., Ltd.) adhere to the both sides of polaroid, is the Polarizer (diaphragm/polaroid/diaphragm) of 100 μ m thereby obtain gross thickness with commercially available TAC film with PVA class bonding agent.With this Polarizer punching press growth 20cm * wide 30cm, and make in the absorption axes of polaroid is set at vertically.
(producing first optical compensating layer)
Under 140 ℃, (trade name, Zeonoa buy from Zeon Corporation, and thickness is 60 μ m, and photoelastic coefficient is 3.10 * 10 with continuous norbornene resin film -12m 2/ N) uniaxial tension is to 1.90 double-length degree, thus preparation is used for the continuous film of first optical compensating layer.The thickness of this film is 45 μ m, phase differential Re in the face 1Be 270nm.With this film punching press growth 20cm * wide 30cm, and its slow axis is set at vertically.
(producing second optical compensating layer)
Under 140 ℃, (trade name, Zeonoa buy from Zeon Corporation, and thickness is 60 μ m, and photoelastic coefficient is 3.10 * 10 with the bornylene resin film with continuous -12m 2/ N) uniaxial tension is to 1.32 double-length degree, thus preparation is used for the continuous film of second optical compensating layer.The thickness of this film is 50 μ m, phase differential Re in the face 2Be 140nm.With this film punching press growth 20cm * wide 30cm, and its slow axis is set at vertically.
(producing the 3rd optical compensating layer)
With the chiral reagent of the nematic liquid crystal compound shown in the 90 weight portion following formulas (10), 10 weight portion following formulas (38) expression, (Irgacure 907, trade name for 5 weight portion Photoepolymerizationinitiater initiaters; Purchase is from Ciba Specialty Chemicals) and 300 weight portion butanone evenly mix, thereby preparation liquid crystal coating fluid.With this liquid crystal coating fluid coated substrates (biaxial stretch-formed PET film), 80 ℃ of following thermal treatments 3 minutes, and carry out aggregation processing, thereby form the 3rd optical compensating layer with this liquid crystal coating fluid of UV-irradiation.Be formed with the substrate punching press growth 20cm * wide 30cm of the 3rd optical compensating layer on it.The thickness of the 3rd optical compensating layer is 2 μ m, phase differential Re in the face 3Be 0nm, and the phase differential Rth of thickness direction 3Be 110nm.
[chem13]
(Polarizer of optical compensating layer is disposed in production)
Polarizer, first optical compensating layer, second optical compensating layer and the 3rd optical compensating layer to above-mentioned acquisition carries out lamination successively.At this, the slow axis of first optical compensating layer, second optical compensating layer and the 3rd optical compensating layer is the state that counterclockwise rotates 15 °, 75 ° and 75 ° with the polaroid absorption axes with respect to Polarizer respectively and carries out lamination.With acrylic pressure-sensitive adhesive (thickness is 20 μ m) polaroid and first optical compensating layer and first optical compensating layer and second optical compensating layer are carried out lamination.Second optical compensating layer and the 3rd optical compensating layer carry out lamination by using isocyanates cure adhesive (thickness is 5 μ m).Subsequently, the substrate (biaxial stretch-formed PET film) that supports the 3rd optical compensating layer is peeled off, and on stripper surface coated with acrylic pressure sensitive bonding agent (thickness is 20 μ m) to adhere to liquid crystal cells.At last, with product punching press growth 4.0cm * thick 5.3cm, thus the acquisition Polarizer that disposes optical compensating layer as shown in Figure 1.
Measure thickness, transmissivity and because the inhomogeneous demonstration that temperature causes of the Polarizer that disposes optical compensating layer of gained.Table 1 has shown embodiment 2 and 3 and relatively hereinafter described
The result of embodiment 1 to 3.
[table 1]
Thickness (μ m) Transmissivity (%) Because the inhomogeneous demonstration that temperature causes
Before the heating (%) Heating back (%) Variable quantity (%)
Embodiment 1 262 0.10 0.21 1.55 1.34
Embodiment 2 340 0.10 7.53 12.18 4.65
Embodiment 3 322 0.10 0.25 1.60 1.35
Comparing embodiment 1 262 0.85 1.22 2.60 1.38
Comparing embodiment 2 262 0.80 1.28 2.70 1.42
Comparing embodiment 3 340 0.85 8.02 12.54 4.52
Embodiment 2
Produce Polarizer, first optical compensating layer and second optical compensating layer according to the mode identical with embodiment 1.
(producing the 3rd optical compensating layer)
(trade name, Arton buy from JSRCorporation, and thickness is 100 μ m, and photoelastic coefficient is 5.00 * 10 with continuous norbornene resin film -12m 2/ N) under 175 ℃, be stretched longitudinally to 1.27 double-length degree, arrive about 1.37 times at 176 ℃ of following cross directional stretchs subsequently, thereby preparation is used for the continuous film (thickness is 65 μ m) of the 3rd optical compensating layer.With this film punching press growth 20cm * wide 30cm, thereby form the 3rd optical compensating layer.Phase differential Re in the face of the 3rd optical compensating layer 3Be 0nm, thickness direction phase differential Rth 3Be 110nm.
(Polarizer of optical compensating layer is disposed in production)
Except second optical compensating layer and the 3rd optical compensating layer being carried out the lamination, produce as shown in Figure 1 the Polarizer that disposes optical compensating layer according to the mode identical with embodiment 1 with acrylic psa (thickness is 20 μ m).The Polarizer that disposes optical compensating layer of gained such as embodiment 1 carry out identical evaluation.Table 1 has shown this result.
Embodiment 3
Produce Polarizer, first optical compensating layer and second optical compensating layer according to the mode identical with embodiment 1.
The liquid crystal coating fluid coated substrates (biaxial stretch-formed PET film) that use prepares according to the mode identical with embodiment 1, under 80 ℃, heat-treated 3 minutes, and carry out aggregation processing, thereby form cholesteric orientation fixed bed (thickness is 2 μ m) with this liquid crystal coating fluid of UV-irradiation.Subsequently, isocyanates curing adhesive (thickness is 5 μ m) is coated cholesteric orientation fixed bed, and by bonding agent that plastic foil (TAC film, thickness are 40 μ m) is adhered thereto, thus form the 3rd optical compensating layer.With the 3rd optical compensating layer punching press growth 20cm * wide 30cm.The thickness of the 3rd optical compensating layer is phase differential Re in 47 μ m, the face 3Be 0nm, thickness direction phase differential Rth 3Be 140nm.
Except second optical compensating layer and the 3rd optical compensating layer being carried out the lamination with acrylic psa (thickness is 20 μ m), successively polaroid, first optical compensating layer, second optical compensating layer and the 3rd optical compensating layer are carried out lamination according to the mode identical, thereby obtain the Polarizer that disposes optical compensating layer as shown in Figure 1 with embodiment 1.Simultaneously, be to make the plastic membranous layer (TAC film) of the 3rd optical compensating layer be positioned at the opposite of second optical compensating layer with second optical compensating layer and the 3rd optical compensating layer lamination.The Polarizer that disposes optical compensating layer of gained such as embodiment 1 carry out identical evaluation.Table 1 has shown this result.
(comparing embodiment 1)
Except the slow axis of first optical compensating layer with respect to the polaroid absorption axes of Polarizer towards counterclockwise rotating 35 °, produce the Polarizer that disposes optical compensating layer according to the mode identical with embodiment 1.The Polarizer that disposes optical compensating layer of gained such as embodiment 1 carry out identical evaluation.Table 1 has shown this result.
(comparing embodiment 2)
Except the slow axis of second optical compensating layer with respect to the polaroid absorption axes of Polarizer towards counterclockwise rotating 35 °, produce the Polarizer that disposes optical compensating layer according to the mode identical with embodiment 1.The Polarizer that disposes optical compensating layer of gained such as embodiment 1 carry out identical evaluation.Table 1 has shown this result.
(comparing embodiment 3)
Except the slow axis of first optical compensating layer with respect to the polaroid absorption axes of Polarizer towards counterclockwise rotating 35 °, produce the Polarizer that disposes optical compensating layer according to the mode identical with embodiment 2.The Polarizer that disposes optical compensating layer of gained such as embodiment 1 carry out identical evaluation.Table 1 has shown this result.
Table 1 has disclosed following content.In an embodiment of the present invention, the slow axis of first optical compensating layer, second optical compensating layer and the 3rd optical compensating layer and the angle initialization between the polaroid absorption axes in preset range, thereby greatly reduced the transmissivity under the orthogonal polarization state.That is to say the light leak when having prevented black display well.Simultaneously, in comparing embodiment, the angle deviating that forms between the slow axis of at least one optical compensating layer and the polaroid absorption axes preset range, so the transmissivity under the orthogonal polarization state is very big.That is, the light leak in the black display is very obvious, can't reach practical level.In addition, in comparing embodiment, the angle deviating that forms between the slow axis of at least one optical compensating layer and the polaroid absorption axes preset range, owing to initially just obtain high value in the experiment of the inhomogeneous demonstration that causes of temperature.Compare with 3 with embodiment 1, embodiment 2 has disclosed cholesteric orientation fixed bed as the 3rd optical compensating layer, thereby prevents light leak and because the inhomogeneous demonstration that temperature causes.And, use the isocyanates gel-type resin to carry out the lamination of the 3rd optical compensating layer, in fact proved in heating process, can prevent from well in the 3rd optical compensating layer, to form slight crack.
Industrial applicibility
The Polarizer that disposes optical compensating layer of the present invention is applicable to various image display devices (for example liquid crystal indicator and self-emission display apparatus).

Claims (8)

1. dispose the Polarizer of optical compensating layer, it comprises polaroid, first optical compensating layer, second optical compensating layer and the 3rd optical compensating layer successively, wherein:
Described first optical compensating layer contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2Phase differential Re in the resin of/N, relation and the face with nx＞ny=nz 1Be 200 to 300nm;
Described second optical compensating layer contains the photoelastic coefficient absolute value and is less than or equal to 2 * 10 -11m 2Phase differential Re in the resin of/N, relation and the face with nx＞ny=nz 2Be 90 to 160nm;
Described the 3rd optical compensating layer has the relation of nx=ny＞nz, and phase differential Re in the face 3Be 0 to 20nm, the phase differential Rth of thickness direction 3Be 30 to 300nm;
The slow axis of the absorption axes of described polaroid and described first optical compensating layer forms 10 ° to 30 ° angle;
The slow axis of the absorption axes of described polaroid and described second optical compensating layer forms 70 ° to 95 ° angle;
The slow axis of the absorption axes of described polaroid and described the 3rd optical compensating layer forms 70 ° to 95 ° angle.
2. the Polarizer that disposes optical compensating layer according to claim 1, the thickness of wherein said the 3rd optical compensating layer are 1 to 50 μ m.
3. the Polarizer that disposes optical compensating layer according to claim 1 and 2, wherein said the 3rd optical compensating layer is made of the cholesteric orientation fixed bed that the selective reflecting wavelength region may is less than or equal to 350nm.
4. the Polarizer that disposes optical compensating layer according to claim 1 and 2, wherein said the 3rd optical compensating layer comprises: be less than or equal to 2 * 10 by having nx=ny＞nz relation and containing the photoelastic coefficient absolute value -11m 2The cholesteric orientation fixed bed that layer that the film of the resin of/N constitutes and selective reflecting wavelength region may are less than or equal to 350nm.
5. liquid crystal panel, it contains an any described Polarizer and liquid crystal cells that disposes optical compensating layer of with good grounds claim 1 to 4.
6. liquid crystal panel according to claim 5, wherein said liquid crystal cells are reflective or semi-transmission-type VA pattern.
7. liquid crystal indicator, it contains with good grounds claim 5 or 6 described liquid crystal panels.
8. image display device, it contains any described Polarizer that disposes optical compensating layer of with good grounds claim 1 to 4.
CNB2005800017181A 2004-12-02 2005-11-25 Polarizing plate with optical compensating layer, and image display using the same Active CN100380206C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2004349387 2004-12-02
JP349387/2004 2004-12-02
JP100958/2005 2005-03-31

Publications (2)

Publication Number Publication Date
CN1906509A true CN1906509A (en) 2007-01-31
CN100380206C CN100380206C (en) 2008-04-09

Family

ID=37674984

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB2005800017181A Active CN100380206C (en) 2004-12-02 2005-11-25 Polarizing plate with optical compensating layer, and image display using the same

Country Status (1)

Country Link
CN (1) CN100380206C (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102707489A (en) * 2011-06-09 2012-10-03 京东方科技集团股份有限公司 Liquid crystal display panel
CN104871079A (en) * 2013-10-31 2015-08-26 日东电工株式会社 Liquid crystal panel and polarizer laminate used in said liquid crystal panel
CN105319766A (en) * 2015-12-01 2016-02-10 深圳市华星光电技术有限公司 Polarization device and displayer
CN107850721A (en) * 2015-07-31 2018-03-27 富士胶片株式会社 Layered product and window
CN110651205A (en) * 2017-05-16 2020-01-03 日东电工株式会社 Circular polarizing film, circular polarizing film with adhesive layer, and image display device
CN111712746A (en) * 2018-06-12 2020-09-25 株式会社Lg化学 Optical device

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1068816A (en) * 1996-08-29 1998-03-10 Sharp Corp Phase difference plate and circularly polarizing plate
JP2003114325A (en) * 2001-10-03 2003-04-18 Nitto Denko Corp Laminated quarter-wave plate, circularly polarizing plate and liquid crystal display device using the same, and method for manufacturing the same
JP2003322855A (en) * 2002-05-01 2003-11-14 Toshiba Corp Liquid crystal display element
JP3849659B2 (en) * 2003-03-13 2006-11-22 セイコーエプソン株式会社 Liquid crystal display device and electronic device
JP4233431B2 (en) * 2003-04-01 2009-03-04 日東電工株式会社 Optical element, polarizing element, illumination device, and liquid crystal display device
JP2004317714A (en) * 2003-04-15 2004-11-11 Sharp Corp Liquid crystal display and laminated retardation plate

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102707489A (en) * 2011-06-09 2012-10-03 京东方科技集团股份有限公司 Liquid crystal display panel
CN104871079A (en) * 2013-10-31 2015-08-26 日东电工株式会社 Liquid crystal panel and polarizer laminate used in said liquid crystal panel
CN107850721A (en) * 2015-07-31 2018-03-27 富士胶片株式会社 Layered product and window
US10642085B2 (en) 2015-07-31 2020-05-05 Fujifilm Corporation Laminate and window
CN107850721B (en) * 2015-07-31 2020-06-16 富士胶片株式会社 Laminated body and window
CN105319766A (en) * 2015-12-01 2016-02-10 深圳市华星光电技术有限公司 Polarization device and displayer
CN110651205A (en) * 2017-05-16 2020-01-03 日东电工株式会社 Circular polarizing film, circular polarizing film with adhesive layer, and image display device
CN111712746A (en) * 2018-06-12 2020-09-25 株式会社Lg化学 Optical device

Also Published As

Publication number Publication date
CN100380206C (en) 2008-04-09

Similar Documents

Publication Publication Date Title
CN1281984C (en) Manufacturing method of double refraction film
CN1235071C (en) Circular polarization plate and liquid crystal display
CN1302299C (en) Polarizing plate with optical compensation function and liquid crystal display device using the same
JP4943696B2 (en) Liquid crystal panel and image display device using the same
CN1672070A (en) Optical film and its manufacturing method
CN1311255C (en) Circular polarizing plate and liquid crystal display device
CN1774654A (en) Optical film, method for producing the same, and image display device using the same
CN1293396C (en) Polarization plate having optical compensation function and liquid crystal display device using the same
CN1748162A (en) Polymeric optical film
CN1818723A (en) Retardation film, polarizing element, liquid crystal panel, and liquid crystal apparatus
CN1656399A (en) Optical film
CN1806194A (en) Liquid crystal display
CN1918491A (en) Elliptical polarization plate, manufacturing method thereof and image display device using elliptical polarization plate
CN1934466A (en) Elliptical polarization plate, optical film, and image display device
CN1934467A (en) Optical film and image display
CN1922514A (en) Elliptic polarizing plate and image display device using the same
EP1876491A1 (en) Liquid crystal panel and liquid crystal display
CN1837932A (en) Wide-viewing angle compensation film and transmission type liquid-crystal display employing the same
CN1926451A (en) Method for manufacturing elliptically polarizing plate and image display device using the elliptically polarizing plate
CN1853122A (en) Optical film and image display
CN1748176A (en) Compensators for liquid crystal displays
CN1934470A (en) Optical film and image display unit
CN1906509A (en) Polarizing plate with optical compensating layer, and image display using the same
JP6303544B2 (en) Liquid crystal display device and polarizing plate
CN1633613A (en) Inclined optical compensation film method for producing the same and liquid crystal display including the same

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant