• 专利附录
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    • 专利摘要:
    A retardation film composed of one polymer film, having a wavelength band at which a phase difference value is positive at a wavelength of 400 to 800 nm, and a wavelength band to be added, wherein Equation 1: ┃R (400) ┃ 10 nm and 2: ┃R A retardation film that satisfies at least one of (700) ┃ ≥ 10 nm and has an absorptivity of 1% by mass or less. This film can be used to compensate for the optical characteristics of the liquid crystal cell of the liquid crystal display and to improve the image quality of the display.
    公开号:KR20010075435A
    申请号:KR1020017003976
    申请日:2000-07-28
    公开日:2001-08-09
    发明作者:우찌야마아끼히꼬；쿠시다타까시
    申请人:야스이 쇼사꾸；데이진 가부시키가이샤；
    IPC主号:
    专利说明:

    Retardation film, retardation film composite and liquid crystal display using the same {PHASE DIFFERENCE FILM, PHASE DIFFERENCE FILM COMPOSITE AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME}
    [2] The retardation film is used in the STN (super twisted nematic) method of the liquid crystal display device and is used to solve problems such as color compensation and enlarged viewing angle. Generally, polycarbonate, polyvinyl alcohol, polysulfone, polyether sulfone, amorphous polyolefin, etc. are used as a material of a color compensation retardation film, A polymer liquid crystal, a discotic liquid crystal in addition to the above-mentioned material as a retardation film material for a viewing angle expansion Etc. are used.
    [3] The quarter wave film which is one type of retardation film can convert circularly polarized light into linearly polarized light, and linearly polarized light into circularly polarized light. This is a liquid crystal display device, especially a reflection type liquid crystal display device of one type of polarizing film using an electrode on the back side as a reflection electrode as viewed from the observer side, an antireflection film comprising a combination of a polarizing film and a quarter wavelength film, and It is intended to be used in combination with a reflective polarizing film that reflects only the circularly polarized light on either side of the right or left turn made of a cholesteric liquid crystal or the like.
    [4] The retardation film used in the above-mentioned polarizing film 1 type reflective liquid crystal display device or a reflective polarizing film has a linearly polarized light with circularly polarized light at a measurement wavelength of 400 to 700 nm, preferably 400 to 780 nm, which is a visible light region. It is necessary to have the action of converting the linearly polarized light into. In order to realize this with one retardation film, the retardation becomes λ / 4 (nm) (100 to 175 (preferably 195 nm)) at a measurement wavelength λ = 400 to 700 nm, preferably 400 to 780 nm. It is an abnormality of the retardation film.
    [5] In order to obtain a film whose phase difference becomes smaller as the measurement wavelength is shorter, such as an ideal quarter wavelength film, Japanese Patent Application Laid-Open No. 10-68816 discloses a quarter wavelength film and a half wavelength film at an appropriate angle. The technique of sticking and using is disclosed. According to this method, when linearly polarized light injects into this film at an appropriate angle, favorable circularly polarized light is obtained in the wavelength range of an almost visible light area | region. However, in the method of JP-A-10-68816, the adhesion angles of the quarter-wavelength film and the half-wavelength film need to adhere the slow axis in the in-plane direction of the film at an angle orthogonal or not parallel, respectively. have. In general, the retardation film made of a polymer material is made roll-to-roll by the stretching process, and thus depends on the stretching method or the refractive anisotropy of the film material. The slow axis in the in-plane direction of the film exists in parallel or perpendicular to the film flow direction. have. Therefore, sticking the slow axis in the in-plane direction of the film at an orthogonal or non-parallel angle means that the adhesive process is applied after being cut to a desired size, for example, in a liquid crystal display device, so as to reduce the yield of the cut or roll to roll. Since it is practically impossible to stick two films continuously with a roll, etc., it is not preferable at the point of productivity.
    [6] Patent No. 2609139 discloses two or three or more kinds of birefringent films made of a transparent stretched plastic film in a combination of different wavelength dependences of retardation due to birefringence, and further lamination of two kinds of birefringent films. In the case of forming a sieve, a laminated retardation film is disclosed in which combinations of different orientations of orientation birefringence are different, and a maximum direction of their in-plane refractive index is non-orthogonal, or a combination of orientations of orientation birefringence is formed. It is. In the method of Patent Publication No. 2609139, retardation control is possible to some extent, but it is necessary to use a plurality of positive or negative films.
    [7] Japanese Laid-Open Patent Publication No. 6-230368 also discloses a retardation film having a birefringence of zero at one or more wavelengths of visible light formed by laminating two or more kinds of stretched films of a polymer. However, since the method of JP-A-6-230368 also adheres two or more polymer films, the adhesion process of obtaining an optically good adhesive film is cumbersome, as in the case of Patent Publication No. 2609139, and therefore two or more sheets. In addition to the cost of producing the film, the cost increases, and is disadvantageous in terms of the thinness of the film.
    [8] The main object of the present invention is to provide a retardation film capable of compensating optical characteristics of a liquid crystal cell of a liquid crystal display device to improve image quality.
    [9] Another object of the present invention is to provide a retardation film having novel optical properties alone.
    [10] Another object of the present invention is to provide a novel laminated retardation film or retardation film-integrated polarizing film in combination with the retardation film to improve the optical properties of other retardation films or polarizing films.
    [11] Another object of the present invention is to provide a retardation film useful for an optical device such as a liquid crystal display device.
    [1] The present invention relates to a novel retardation film. In particular, the retardation film which has the novel optical characteristic useful in optical elements, such as a liquid crystal display device and an anti-glare film, and the laminated retardation film using it, the retardation film integrated polarizing film, and the liquid crystal using the same An optical device such as a display device.
    [22] 1 shows a retardation film of the present invention.
    [23] 2 shows a laminated retardation film using the retardation film of the present invention.
    [24] 3 shows a retardation film integrated polarizing film using the retardation film of the present invention.
    [25] 4 shows a liquid crystal display device using a phase difference film integrated polarizing film of the present invention.
    [26] 5 shows retardation wavelength dispersion of the retardation film in Example 1. FIG.
    [27] FIG. 6 shows retardation wavelength dispersion of a laminated retardation film in Example 4. FIG.
    [28] 7-9 shows the phase difference wavelength dispersion of the retardation film in Examples 8-10.
    [29] Best Mode for Carrying Out the Invention
    [30] (Features of the retardation film of the present invention)
    [31] The retardation film of the present invention has a wavelength band at which the phase difference value is positive at a wavelength of 400 to 800 nm, preferably 400 to 780 nm or 400 to 700 nm, and a wavelength band to be added by one polymer film. . In the range of 400-800 nm, normally, (1) wavelength becomes large and a phase difference value becomes large, and when wavelength 400 nm, it takes a negative phase difference value, and at 800 nm, it takes a positive phase difference value, or (2) a wavelength becomes large, The retardation value becomes small, the positive retardation value is taken at a wavelength of 400 nm, and the negative retardation value is taken at 800 nm. And usually, there is one wavelength within which the phase difference value becomes zero within the wavelength range.
    [32] In addition, the retardation film of the present invention is another feature that satisfies at least one of the equations (1) and (2).
    [33] [Equation 1]
    [34] ┃R (400) ┃ ≥10 nm (1)
    [35] [Equation 2]
    [36] ┃R (700) ┃ ≥10 nm (2)
    [37] (Wherein, “R (400)” and “R (700)” are phase difference values at wavelengths of 400 nm and 700 nm)
    [38] In order for the retardation film of this invention to be used as a retardation film, it has one wavelength which becomes 0 in retardation value in the range of 400-800 nm, More preferably, 400-700 nm, and has a phase difference value more than a predetermined | prescribed at a specific wavelength. It is necessary to satisfy one or more of Equations 1 and 2 above. When the retardation value is always close to 0 or 0 in the wavelength range, it is difficult to fulfill the function as the retardation film, and therefore it is important to satisfy at least one of the above formulas (1) and (2). More preferably
    [39] ┃R (400) ┃ ≥20 nm
    [40] ┃R (700) ┃ ≥20 nm
    [41] More preferably
    [42] ┃R (400) ┃ ≥30 nm
    [43] ┃R (700) ┃ ≥30 nm
    [44] At least one of
    [45] However, if the water absorption of the polymer film is not 1 mass% or less, there is a problem in practical use as a retardation film. Therefore, the film should be a polymer film that satisfies the condition of 1 mass% or less, preferably 0.5 mass% or less.
    [46] (Polymer film material)
    [47] The polymeric material which comprises the retardation film of this invention is not specifically limited, What is necessary is just a blend or copolymer which satisfy | fills the said conditions, or a combination thereof, the material excellent in heat resistance, favorable optical performance, and a solution film formation, especially Thermoplastic polymers are preferred. For example, one kind or two or more kinds can be appropriately selected from polyarylate, polyester, polycarbonate, polyolefin, polyether, polysulfin-based copolymer, polysulfone, polyether sulfone and the like. However, in practical use as a retardation film, the water absorption of a polymer film shall be 1 weight% or less.
    [48] If it is a blend polymer, since it needs to be optically transparent, it is preferable that the refractive index of a commercial blend or each polymer is about the same. As a specific combination of the blend polymer, for example, poly (methyl methacrylate) as a polymer having negative optical anisotropy, and poly (vinylidene fluoride), poly (ethylene oxide), poly (vinylidene) as a polymer having positive optical anisotropy A combination of fluoride-co-trifluoroolethylene), poly (phenylene oxide) as a polymer having positive optical anisotropy, polystyrene, poly (styrene-co-lauroyl maleimide) as a polymer having negative optical anisotropy, Combination of poly (styrene-co-cyclohexylmaleimide), poly (styrene-co-phenylmaleimide), poly (styrene-co-maleic anhydride) having negative optical anisotropy, and polycarbonate having positive optical anisotropy, and definition Poly (acrylonitrile-co-butadiene) having optical anisotropy and poly (acrylonitrile-co-styrene) having negative optical anisotropy; In it not limited. In particular, a combination of polystyrene and poly (phenylene oxide) such as poly (2,6-dimethyl-1,4-phenylene oxide) is preferable from the viewpoint of transparency. In the case of such a combination, it is preferable that the ratio of the said polystyrene occupies 61 mass% or more and 75 mass% or less of the whole.
    [49] As the copolymer, for example, poly (butadiene-co-styrene), poly (ethylene-co-styrene), poly (acrylonitrile-co-butadiene), poly (acrylonitrile-co-butadiene-co-styrene), Polycarbonate copolymer, polyester copolymer, polyester carbonate copolymer, polyarylate copolymer, etc. can be used. In particular, since the segment having a fluorene skeleton can be negative optically anisotropic, a polycarbonate copolymer, a polyester copolymer, a polyester carbonate copolymer, a polyarylate copolymer, etc. having a fluorene skeleton is more preferable. Is used.
    [50] (Film of polycarbonate having fluorene skeleton)
    [51] As the polymer film of the retardation film of the present invention, a polycarbonate copolymer prepared by reacting bisphenols with a carbonate ester-forming compound such as phosgene or diphenyl carbonate is excellent in transparency, heat resistance and productivity, and can be particularly preferably used. It is preferable that the polycarbonate copolymer includes a structure having a fluorene skeleton. It is preferable that 1-99 mol% of components which have a fluorene skeleton are contained.
    [52] Preferred polycarbonates as polymer films of the retardation film of the present invention are those represented by the following general formula (I):
    [53]
    [54] (In formula (I), R 1 to R 8 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group of 1 to 6 carbon atoms, X is
    [55]
    [56] to be)
    [57] A repeating unit represented by the following Chemical Formula II:
    [58]
    [59] (In Formula II, R 9 to R 16 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 22 carbon atoms, and Y is
    [60]
    [61] Is selected. R 17 to R 19 , R 21 and R 22 in Y are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 22 carbon atoms, and R 20 and R 23 are each independently a hydrocarbon group having 1 to 20 carbon atoms And Ar is an aryl group having 6 to 10 carbon atoms)
    [62] It consists of a polymer film of polycarbonate composed of repeating units represented by the formula, wherein the repeating unit represented by the formula (I) accounts for 30 to 90 mol% of the entire polycarbonate, the repeating unit represented by the formula (II) is 70 to 10 of the total It is the material that accounts for mole%.
    [63] The material is a polycarbonate copolymer comprising a repeating unit having a fluorene skeleton represented by the formula (I) and a repeating unit represented by the formula (II), and a polycarbonate composed of a repeating unit having a fluorene skeleton represented by the formula (I) It is a composition of the polycarbonate which consists of repeating units represented by II (henceforth a blend polymer). In the case of a copolymer, two or more types of repeating units represented by the said Formula (I) and (II) may respectively be combined, and also in a case of a composition, the said repeating units may combine two or more types, respectively.
    [64] In the general formula (I), R 1 to R 8 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group of 1 to 6 carbon atoms. As such a C1-C6 hydrocarbon group, aryl groups, such as alkyl groups, such as a methyl group, an ethyl group, isopropyl group, and a cyclohexyl group, and a phenyl group, are mentioned. Among these, a hydrogen atom and a methyl group are preferable.
    [65] In formula (II), R 9 to R 16 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 22 carbon atoms. As such a C1-C22 hydrocarbon group, aryl groups, such as a C1-C9 alkyl group, such as a methyl group, an ethyl group, isopropyl group, and a cyclohexyl group, a phenyl group, a biphenyl group, and a terphenyl group, are mentioned. , A hydrogen atom and a methyl group are preferable.
    [66] In the above formula (II), R 17 to R 19 , R 21 and R 22 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 22 carbon atoms. have. R 20 and R 23 are each independently selected from a hydrocarbon group having 1 to 20 carbon atoms, and the same ones described above for the hydrocarbon group can be given. Ar is a C6-C10 aryl group, such as a phenyl group and a naphthyl group.
    [67] The content of formula (I), that is, the copolymer composition in the case of the copolymer, the blend composition ratio in the case of the composition is 30 to 90 mol% of the entire polycarbonate. If it is out of such a range, it does not have a wavelength band to which the phase difference value becomes positive in the retardation film 1 sheet at the measurement wavelength 400-800 nm, and the wavelength band to which it adds. 35-85 mol% of the whole polycarbonate is preferable, and, as for the content rate of the said Formula (I), 40-80 mol% is more preferable.
    [68] Herein, the molar ratio can be determined by the entirety of the bulk of the polycarbonate constituting the polymer film, for example by nuclear magnetic resonance (NMR) apparatus, regardless of the copolymer or blend polymer.
    [69] The copolymers and / or blend polymers described above can be prepared by known methods. As the polycarbonate, a method by polycondensation of a dihydroxy compound and phosgene, a melt polycondensation method and the like are preferably used. In the case of a blend, a compatible blend is preferable, but even if it is not completely compatible, it is possible to suppress light scattering between components and to improve transparency by matching the refractive index between the components.
    [70] Among the polycarbonates having the fluorene skeleton, particularly the following first, second and third copolymerized polycarbonates are preferable as the material of the polymer film constituting the retardation film of the present invention.
    [71] First Polycarbonate: Formula 3:
    [72]
    [73] (In the formula (3), R 1 to R 8 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group of 1 to 6 carbon atoms, X is represented by the following formula 4:
    [74]
    [75] to be)
    [76] A repeating unit represented by the following Chemical Formula 5:
    [77]
    [78] (In Formula 5, R 9 to R 16 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 6 carbon atoms.)
    [79] A polycarbonate composed of a repeating unit represented by the above, wherein the repeating unit represented by the formula (3) comprises 60 to 90 mol% of the entire polycarbonate, the repeating unit represented by the formula (3) comprises a polycarbonate of 40 to 10 mol% , or
    [80] Second polycarbonate: a repeating unit represented by Chemical Formula 3, and the following Chemical Formula 6
    [81]
    [82] (In Formula 6, R 17 to R 24 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 6 carbon atoms.)
    [83] A polycarbonate composed of repeating units represented by the above formula, wherein the repeating unit represented by the above formula (1) accounts for 55 to 85 mol% of the entire polycarbonate, and the repeating unit represented by the formula (6) comprises 45 to 15 mol% Carbonate, or
    [84] Third polycarbonate: a repeating unit represented by the formula (1), and the formula
    [85]
    [86] (In Formula 7, R 25 to R 32 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 6 carbon atoms.)
    [87] A polycarbonate composed of a repeating unit represented by the above, wherein the repeating unit represented by the formula (1) comprises 55 to 85 mol% of the entire polycarbonate, the repeating unit represented by the formula (7) is 45 to 15 mol% Carbonates.
    [88] Regarding the first, second and third polycarbonates, in the general formula (3), R 1 to R 8 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group of 1 to 6 carbon atoms. As a C1-C6 hydrocarbon group, a methyl group, an ethyl group, a propyl group, a butyl group, etc. can be illustrated. In addition, X is a fluorene ring. It is preferable that all of R 1 to R 8 are hydrogen atoms, or at least one of R 1 or R 3 is a methyl group, and at least one of R 6 or R 8 is a methyl group.
    [89] Regarding the first polycarbonate, in the repeating unit represented by Formula 5, R 9 to R 16 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group of 1 to 6 carbon atoms. As a C1-C6 hydrocarbon group, a methyl group, an ethyl group, a propyl group, a butyl group, etc. can be illustrated. In Formula 5, R 9 to R 16 are preferably hydrogen atoms.
    [90] The repeating unit represented by Formula 3 occupies 60 to 90 mol% of the entire polycarbonate, and the repeating unit represented by Formula 5 occupies 40 to 10 mol%. Outside this range, the retardation value does not have a band on both sides of the positive and negative sides at a wavelength of 400 to 800 nm. Depending on the conditions, when produced under the usual uniaxial stretching conditions adopted in the examples described later, the repeating unit represented by Formula 3 occupies 71 to 79 mol% of the entire polycarbonate, and the repeating unit represented by Formula 5 Is a negative phase difference value at a wavelength of 400 nm, a positive phase difference value at a wavelength of 800 nm, and a phase difference film having a wavelength band in which a phase difference value is positive in the range and a wavelength band to be added. It can implement | achieve with the said polycarbonate film.
    [91] Regarding the second polycarbonate, in the repeating unit represented by Formula 6, R 17 to R 24 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 6 carbon atoms. As a C1-C6 hydrocarbon group, a methyl group, an ethyl group, a propyl group, a butyl group, etc. can be illustrated. In Formula 6, R 17 to R 24 are preferably hydrogen atoms.
    [92] The repeating unit represented by Formula 3 occupies 55 to 85 mol% of the entire polycarbonate, and the repeating unit represented by Formula 6 occupies 45 to 15 mol%. Outside this range, the retardation value does not have a band on both sides of the positive and negative sides at a wavelength of 400 to 800 nm. Depending on the conditions, when produced under the usual uniaxial stretching conditions adopted in the examples described below, the repeating unit represented by Formula 3 occupies 65 to 73 mole% of the entire polycarbonate, and is represented by the aforementioned Formula 6 Is a negative phase difference value at a wavelength of 400 nm, a positive phase difference value at a wavelength of 800 nm, and a phase difference plate having a wavelength band in which the phase difference value is positive and a wavelength band to be added in the range. It can implement | achieve with the said polycarbonate film.
    [93] Regarding the third polycarbonate, R 25 to R 32 in the repeating unit represented by Formula 7 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 6 carbon atoms. As a C1-C6 hydrocarbon group, a methyl group, an ethyl group, a propyl group, a butyl group, etc. can be illustrated. In the general formula (7), R 25 to R 32 are preferably hydrogen atoms.
    [94] The repeating unit represented by Formula 3 occupies 55 to 85 mol% of the entire polycarbonate, and the repeating unit represented by Formula 7 occupies 45 to 15 mol%. Outside this range, the retardation value does not have a band on both sides of the positive and negative sides at a wavelength of 400 to 800 nm. Depending on the conditions, when produced under the usual uniaxial stretching conditions adopted in the examples described later, the repeating unit represented by Formula 3 occupies 66 to 74 mol% of the entire polycarbonate, and the repeating unit represented by Formula 7 Is a negative phase difference value at a wavelength of 400 nm, a positive phase difference value at a wavelength of 800 nm, and a phase difference plate having a wavelength band in which the phase difference value is positive and a wavelength band added in the range. It can implement | achieve with the said polycarbonate film.
    [95] In the polycarbonate, the repeating unit represented by the general formula (3) corresponds to the negative refractive index anisotropic component, and the repeating unit represented by the general formulas (5), 6, and 7 is considered to correspond to the positive refractive index anisotropic component.
    [96] The stretching conditions of the polycarbonate are (Tg-30) to (Tg + 50) ° C (Tg is glass transition temperature, ° C), and the draw ratio is in the range of 1.01 to 4 times, preferably (Tg-10). (Tg + 20) degreeC and a draw ratio are 1.1-2.5 times. It is thought that retardation wavelength dispersion is determined according to the material of polycarbonate and its orientation state.
    [97] The molecular weight of the polycarbonate is defined by intrinsic viscosity measurement using methylene chloride as a solvent, but the intrinsic viscosity is preferably 0.30 to 2.0 dl / g.
    [98] As a manufacturing method of a polycarbonate, the method by polycondensation of a dihydroxy compound and phosgene, the melt polycondensation method, etc. are used preferably. When blending and using two or more kinds of polycarbonates, a commercial blend is preferable, but it is possible to suppress light scattering between components and to improve transparency by matching the refractive index between the components even if they are not completely used.
    [99] (Blend film of polyphenylene oxide and polystyrene)
    [100] Another preferred material for the polymer film constituting the retardation film of the present invention is a blend of polyphenylene oxide and polystyrene. This combination is advantageous as a retardation film because commercial blending is possible and haze is less likely to occur. Moreover, poly (2,6-dimethyl-1,4-phenylene oxide) mentioned as a specific example of polyphenylene oxide has positive refractive anisotropy, and polystyrene has negative refractive anisotropy.
    [101] As for the blend ratio of polyphenylene oxide and polystyrene in this polymer blend film, the content ratio of polystyrene is 61-75 mass% of the whole, and poly (2,6-dimethyl-1,4-phenylene oxide) is 39-25. It is preferable to set it as the mass%.
    [102] The retardation film of this invention using this polymer blend film can be manufactured by extending | stretching the polymer blend film which consists of the said polyphenylene oxide and polystyrene normally. Although the degree of acetylation of cellulose acetate depends on the conditions, in the case of producing under normal uniaxial stretching conditions adopted in the examples described later, the content ratio of polystyrene is 66 to 67 mass% of the whole, and poly (2,6-dimethyl- When 1,4-phenylene oxide) is 34 to 33 mass%, a positive phase difference value is taken at a wavelength of 400 nm, a negative phase difference value is taken at a wavelength of 800 nm, and a wavelength band in which the phase difference value is positive in the range and an added wavelength band. The retardation film which has a can be realized with the said one blend film.
    [103] As molecular weight of polystyrene used, when it defines by limit viscosity measurement using methylene chloride as a solvent, it is preferable that limit viscosity is 0.20-2.5 dl / g.
    [104] Moreover, polystyrene may have stereoregularity.
    [105] As molecular weight of the polyphenylene oxide used, it is preferable that the intrinsic viscosity at the time of being prescribed | regulated by the intrinsic viscosity measurement using chloroform as a solvent is 0.20-2.5 dl / g.
    [106] In order to form the polymer blend of the said polyphenylene oxide and polystyrene in order to obtain the retardation film of this invention, it is preferable that it is the solution cast film forming which is a well-known method. As the organic solvent, known solvents such as chloroform and dioxolane can be used.
    [107] (Manufacture of Retardation Film)
    [108] The retardation film of the present invention can be produced by film-forming a polymer material of a copolymer or blend composed of a suitable combination of positive and negative refractive index anisotropy described above by a known melt extrusion method, a solution cast method, and then stretching. have. The solution cast method is used more preferably from a viewpoint of film thickness nonuniformity, an external appearance, etc. As the solvent in the solution casting method, methylene chloride, dioxolane and the like are preferably used.
    [109] Moreover, although the well-known extending | stretching method can also be used for the extending | stretching method, Preferably it is uniaxial stretching. Although monoaxial stretching has longitudinal and lateral stretching, both can be used preferably. Phthalic acid esters such as dimethyl phthalate, diethyl phthalate and dibutyl phthalate, phosphoric acid esters such as tributyl phosphate, aliphatic dibasic esters, glycerin derivatives, glycol derivatives and the like which are known plasticizers for the purpose of improving the stretchability are used. You may extend | stretch and extend the organic solvent used at the time of film forming mentioned above in a film. As the quantity of this organic solvent, it is preferable that it is 1-20 mass% with respect to polymer solid content.
    [110] Although the retardation film of this invention can be obtained by performing normal uniaxial stretching of a polymer film, you may perform extending | stretching, sequential expansion, simultaneous biaxial stretching, etc. which enlarge the refractive index of a well-known film thickness direction.
    [111] (Addition of low molecular weight compound having optical anisotropy)
    [112] Moreover, you may add the low molecular compound which has optical anisotropy to the retardation film which consists of a polymeric material of this invention as long as it has a wavelength band to which the phase difference value becomes positive at wavelength 400-800 nm, and a wavelength band added. In this case, as the quantity of the said low molecular weight compound, when the total retardation film mass is 100 mass parts, it is preferable that it is 20 mass parts or less, More preferably, it is 10 mass parts or less. The purpose of the addition of the low molecular weight compound is to delicately control the retardation wavelength dispersion, when exceeding 20 parts by mass, significantly lower the glass transition temperature of the polymer material, precipitate from the polymer material, or cause phase separation and blur This may cause problems such as inability to maintain transparency. The retardation film of the present invention is substantially made of a polymer material, and its physical properties are intended to realize specific retardation wavelength dispersion. The low molecular weight compound supplements the properties of the polymer as a so-called additive. Since the retardation film of this invention is made by extending | stretching substantially near the glass transition temperature of a high molecular material, it is preferable that this low molecular weight compound does not sublimate or vaporize at the glass transition point temperature of the high polymer material added. In addition, it is preferable that the low molecular weight compound does not lose transparency, for example, even if the compatibility with the polymer material of the retardation film is poor or the compatibility is low, for example, the refractive index is almost the same.
    [113] The low molecular weight compound having optical anisotropy herein is a compound which has anisotropy of refractive index in a molecular structure due to its asymmetric molecular structure, and is preferably an organic substance having a molecular weight of 3000 or less. Whether or not the low molecular compound has optical anisotropy is determined by whether the retardation wavelength dispersion of the retardation film changes when added to the retardation film of the present invention and when not added. That is, the low molecular compound with optical anisotropy is defined here as that when added to a retardation film, the phase difference wavelength dispersion of a retardation film changes. When molecular weight exceeds 3000, it is easy to produce phase separation with the polymeric material which is a main material of retardation film, and it is unpreferable as mentioned above.
    [114] There is no limitation in particular as such a low molecular weight compound, For example, a liquid crystal, a polymeric liquid crystal, saccharose acetate, xylene, toluene, biphenyl, terphenyl, a dichroic dye, a pigment, a dye, a pigment, a near-infrared absorption pigment, an oligomer And dialkyl phthalate.
    [115] As a method to add, the well-known method used generally in the plasticizer addition of a polymeric material can be used. Moreover, the said low molecular weight compound may also function as a plasticizer.
    [116] And when using a polycarbonate as the polymer film of this invention as mentioned above, when the low molecular compound which has the said refractive index anisotropy is added, the preferable copolymer composition ratio (molar ratio) of a polycarbonate may shift slightly.
    [117] (Other additives)
    [118] Moreover, you may add ultraviolet absorbers, such as phenyl salicylic acid, 2-hydroxy benzophenone, and triphenyl phosphate, the bluing agent for changing a color, antioxidant, etc. to the retardation film of this invention.
    [119] (Film thickness)
    [120] As a film thickness of retardation film, it is preferable that they are 1 micrometer-400 micrometers. More preferably, it is 10-200 micrometers, More preferably, it is 30-150 micrometers.
    [121] (Adjustment of other optical properties of the film)
    [122] As a required characteristic of the retardation film used in a liquid crystal display device, a reflective polarizing film, etc., it may be required that a phase difference does not change even if the angle which injects into a retardation film changes from front entrance to oblique incidence. In this case, it is between the three-dimensional refractive index n x, z N represented by n y, n z (n x -n z) / (n x -n y) of 0.3 ~ 1.5 is preferable. Especially when Nz = 0.5, even if the angle which injects into a retardation film changes from a front incident, hardly a phase difference changes. This three-dimensional refractive index is obtained by assuming that the retardation film is a refractive index rotary ellipsoid and measuring the incident angle dependency of the phase difference. The measurement wavelength is preferably established at 400 to 800 nm, preferably at 400 to 780 nm, but may be established at 400 to 700 nm.
    [123] By applying known stretching and film forming techniques to the polymer film in the present invention, n x ≒ n y > n z , n x ≒ n y <n z , n x > n y > n z , n x > n z > It is possible to obtain a retardation film having various optical properties such as n y , n x > n y ≒ n z . Moreover, these optical axes can also be manufactured. As described above, the phase difference wavelength dispersion is controlled by the polymer alignment state and the polymer chemical structure represented by the three-dimensional refractive index, and the like. According to the present invention, it is possible to obtain a viewing angle improvement film or a color compensation film, which can contribute to the improvement of the image quality of the liquid crystal display device.
    [124] (How to use film)
    [125] In addition, the retardation film of the present invention may be used as a base film and a retardation film instead of the glass substrate on which the liquid crystal layer of the liquid crystal display is sandwiched.
    [126] In addition, the retardation film of the present invention may be a circularly polarized film by adhering with a polarizing film through an adhesive layer and an adhesive layer, or may be coated with any material on the retardation film to improve wet heat durability or to improve solvent resistance.
    [127] (Laminated Retardation Film)
    [128] The retardation film of this invention can be laminated | stacked and used with the retardation film whose phase difference value is positive or negative in the measurement wavelength 400-800 nm range. Retardation film whose retardation value here is positive means (Tg-30)-(Tg + 50) degreeC of the polymeric material of retardation film, Preferably it is (Tg +/- 20) degreeC, More preferably, it is (Tg-10) degreeC When it is uniaxially stretched at a stretching temperature of (Tg + 20) ° C., the stretching direction becomes a slow axis in which the stretching direction is the maximum direction of the in-plane refractive index at a measurement wavelength of 400 to 800 nm, and the phase difference value is the same as above. When extending | stretching, it means that the extending | stretching direction orthogonally crosses a slow axis with a measurement wavelength of 400-800 nm. By retarding the retardation film of the present invention with a retardation film having a positive or negative retardation value and using it as a (lamination) retardation film, retardation wavelength dispersion of another retardation film can be controlled, and as a result, image quality of a liquid crystal display device or the like Can contribute to improvement. This is one of the special effects of the present invention.
    [129] Basically, the orientation to be laminated is appropriately set depending on the application. For example, a retardation film having a wavelength dispersion characteristic that is positive on the short wavelength side and negative on the short wavelength side among the retardation films of the present invention is used as another retardation film. It is possible to control the retardation dispersion characteristics of other retardation films by stacking the stretching axes in parallel with each other. Alternatively, retardation films having wavelength dispersion characteristics added to the positive and long wavelength sides of the retardation film of the present invention on the positive and long wavelength sides are laminated with mutually orthogonal stretching axes and retardation values of different retardation films. Dispersion characteristics can be controlled. As a result, other retardation films are improved such that the desired retardation characteristics, for example, the retardation on the short wavelength side is small and the retardation on the long wavelength side is large, or are particularly preferably used in the polarizing film type 1 reflective liquid crystal display device, for example, wavelength ( (lambda)) It becomes possible to produce the wideband (lambda) / 4 film whose phase difference becomes almost a quarter wavelength in 400-800 nm. The retardation on the short wavelength side and the retardation on the long wavelength side mean that the retardation value at wavelength 550 nm is larger than the retardation value at wavelength 450 nm.
    [130] Moreover, when producing a wideband (lambda) / 4 film by the above combination, for example, another retardation film having a retardation value having a positive retardation value may be used as another retardation film having a retardation wavelength dispersion characteristic that the retardation is shorter for shorter wavelengths and larger for the longer wavelengths.
    [131] On the contrary, the phase difference dispersion characteristics of other phase difference films can be controlled by laminating retardation films added on the short wavelength side and positive on the long wavelength side of the retardation film of the present invention with different phase difference values as the positive phase difference values. Can be. As a result, other retardation films are improved so that the desired retardation characteristics, for example, the retardation is large on the short wavelength side and the retardation on the long wavelength side, are improved, for example, in a fast response super twist nematic liquid crystal display device having a large birefringence wavelength dispersion in the liquid crystal cell. It can be used as a retardation film which has a large birefringent wavelength dispersion used preferably.
    [132] These are described in more detail in Examples, but by laminating the retardation films in this way, it becomes possible to control the wavelength dispersion characteristics of the retardation.
    [133] In this case, since the stretching axes are laminated both in parallel, for example, if any film is made by longitudinal uniaxial stretching, the adhesion step can be performed by roll-to-roll, which is very advantageous in terms of productivity. Moreover, when manufacturing a wideband (lambda) / 4 film by the above combinations, you may use a thing with a shorter phase difference, for example, the shorter wavelength in phase difference wavelength dispersion of the phase difference film whose phase difference value is positive.
    [134] These are described in more detail in the examples described later, but by laminating these retardation films, it becomes possible to control the wavelength dispersion characteristics of the retardation.
    [135] By the way, even in the method of patent 2609139, retardation control to some extent is possible, In this case, it is necessary to use a plurality of positive or negative films. On the other hand, as described above, the retardation film of the present invention having a retardation wavelength dispersion is added on the short wavelength side and is positive on the long wavelength side by laminating with one other retardation film having a certain wavelength dispersion, for example, at a measurement wavelength of 550 nm. Although the retardation value of the other retardation film is not to be changed, very delicate retardation wavelength dispersion control such as making the retardation smaller on the shorter wavelength side and larger on the longer wavelength side than the wavelength can be achieved by the present invention. Moreover, the retardation film which has the band to which the retardation value is positive and the band which is added in the measurement wavelength 400-800 nm of this invention is not only used in combination with another retardation film in this way, It is also possible to improve the image quality by compensating for the optical characteristics of the liquid crystal cell.
    [136] In addition to the liquid crystal display device, other display devices such as an organic electroluminescence display (sometimes referred to as OLED), a plasma display, a field emission display, an inorganic electroluminescence display, etc. In the light emitting device, the retardation film of the present invention may be used in combination with a polarizing film or the like.
    [137] As a material of the retardation film whose retardation value becomes positive in the whole range of wavelength 400-800 nm, it is preferable that it is a polymeric material, For example, polycarbonate, polyester, polyarylate, polyolefin, polyether, polyphenylene oxide, polysulfone, It is preferable to use a polyether sulfone, a polyvinyl alcohol, an amorphous polyolefin, a liquid crystalline polymer, a polymerizable liquid crystal orientated and cured. Moreover, as a negative phase difference film material, it is preferable to use polystyrene, polycarbonate which has a fluorene skeleton, triacetyl cellulose, etc. are used. In terms of transparency and high heat resistance, polycarbonate is particularly preferable. As the bisphenol component constituting the polycarbonate, bisphenol A, biscresol, bisphenol having a fluorene skeleton, bisphenol having an isophorone skeleton, and the like, having a cyclohexane skeleton Bisphenol etc. can be illustrated. Moreover, the copolymer which has these or two types may be sufficient. In particular, homopolymers having bisphenol A as a bisphenol component are more preferred.
    [138] Moreover, you may laminate | stack an optical compensation film which consists of a discotic liquid crystal, the polymer liquid crystal which has a distortion structure, etc. with the retardation film of this invention.
    [139] When the retardation film of this invention is laminated | stacked with another retardation film and is used as a quarter wavelength film, it is preferable that the retardation value in measurement wavelength 550nm is 1/4 wavelength, Specifically, it is 110 nm- It is preferable that it is 160 nm. This value is set according to a use. Such a quarter wavelength film is a linear type of polarized light in a reflection type liquid crystal display device using only one polarizing film or a reflection type liquid crystal display device including a guest host liquid crystal and a quarter wave film. Converts circularly polarized light into linearly polarized light by combining linearly polarized light with a device that reflects only circularly polarized light on one side, which is used as a luminance enhancing film of a transmissive liquid crystal display device with a back light. It can be used as an element or the like.
    [140] (Phase Film Integrated Polarizing Film)
    [141] The retardation film of the present invention is conventionally formed by adhering a retardation film-integrated polarizing film by adhering a polarizing film containing a dichroic absorbing material such as ordinary iodine or dye, or a reflective polarizing film that reflects or scatters only one side of polarized light. In combination with a retardation film, a difficult thing can be realized. For example, in the retardation film of the present invention, the phase difference is almost 0 nm at the measurement wavelength of 550 nm, and the polarization at the measurement wavelength of 550 nm is achieved by adhering the dichroic absorption type polarizing film to the positive and negative wavelengths in the short wavelength region. It is possible to change the wavelength dispersion of the emission polarization state of the polarizing film by changing only the polarization state of another wavelength without changing the state.
    [142] Moreover, although the triacetyl cellulose film has been used as a protective film of the polarizing film in which iodine or a dichroic dye was added to polyvinyl alcohol conventionally, it is also possible to use the retardation film of this invention instead of this protective film. In that case, in order to improve adhesiveness with a polarizing film, you may apply | coat various coating agents. For such a purpose, a urethane-based resin is preferably used as the coating agent. In order that an adhesive agent, an adhesive, etc. may suppress interfacial reflection in it, it is preferable that refractive index matches with the above-mentioned film, and it is transparent, and also it considers the degree of thermal contraction of these films, and is selected suitably.
    [143] This retardation film integrated polarizing film can be used not only as a liquid crystal display device but also as the above-mentioned light emitting element, a touch panel, etc., for example as an antireflection film.
    [144] (LCD)
    [145] The improvement of image quality can be implement | achieved by using the above-mentioned retardation film and retardation film integrated polarizing film for a liquid crystal display device. In addition, you may use the retardation film of this invention instead of a glass substrate. In this case, since the optical member of the liquid crystal display device can be reduced and the thickness, which is a drawback of the glass substrate, can be made thin, blurring of the image due to parallax due to the thickness of glass, which is a problem in particular in the reflective liquid crystal display device, is caused. It is possible to prevent, and to replenish the fragility of the glass substrate, and the like.
    [146] (Configuration diagram of the embodiment)
    [147] As shown in FIG. 2, the retardation film 1 of the present invention shown in FIG. 1 may be laminated with another retardation film 2 to form a laminated retardation film 3, or may be laminated with a polarizing film 4 to form a retardation film integrated polarizing film 5. have. If necessary, a well-known adhesive can be used for lamination.
    [148] As shown in Fig. 4, the retardation film of the present invention is preferably used by mounting the retardation film 1 alone or as a laminated retardation film 3 or a retardation film integrated polarizing film 5 in the liquid crystal display device 9. In FIG. 4, 6 is a glass substrate with an electrode, 7 is a liquid crystal layer, 8 is sealing.
    [12] Disclosure of the Invention
    [13] The inventors of the present invention have widely studied as a material having excellent optical properties. Since the retardation film is an optical use, a material having a low light absorption in a measurement wavelength and a transparent material, and a glass transition point temperature of 100 DEG C or more, particularly preferably Attention has been paid to polymer materials as materials which exhibit 120 ° C or more, and furthermore, 150 ° C or more, and are advantageous in terms of formability. Although the polymeric material becomes both crystalline, amorphous, and liquid crystalline, the amorphous polymer is generally able to form a solution film, and is more preferable in the use which should suppress retardation unevenness etc. as much as possible like a retardation film. From such a viewpoint, as the polymer material, polycarbonate, polyester, polyarylate, polyolefin, and the like are considered to be particularly advantageous in terms of productivity and height of molecular design freedom such as copolymerization.
    [14] On the other hand, the present inventors have studied in terms of optical properties of the blended polymer consisting of a polymer having positive refractive anisotropy and a polymer having negative refractive anisotropy, a monomer component of a polymer having positive refractive anisotropy and a polymer having negative refractive anisotropy When extending | stretching the polymer film comprised from the copolymer which consists of monomer components, or these combinations, it discovered that the polymer film which shows the outstanding characteristic as retardation film is obtained. The polymer having positive and negative refractive anisotropy herein refers to a polymer having positive refractive anisotropy when the polymer film is uniaxially stretched, when the maximum direction of the refractive index in the in-plane direction of the film, that is, the slow axis is almost identical to the stretching direction. On the other hand, the slow axis almost perpendicular to the stretching direction is defined herein as a polymer having negative refractive anisotropy. Like materials such as polystyrene, depending on uniaxial stretching conditions, there may be positive refractive anisotropy or negative refractive anisotropy. Here, the glass transition point temperature (glass transition point temperature -10), which is a commercially available retardation film, is used. It is assumed to be defined as refractive anisotropy which is expressed when uniaxially stretching at the stretching temperature at (glass transition point temperature + 20 ° C). In addition, these measurements shall be performed by the polarization analysis method in measurement wavelength 550nm.
    [15] Conventionally, in the measurement wavelength 400-800 nm, the presence of the retardation film which has the band to which the retardation value becomes positive and the band to add in one retardation film is not known. MEANS TO SOLVE THE PROBLEM As a result of earnestly examining the material which gives such retardation film, the polymer of any kind of polycarbonate, the blend of polypinylene oxide, and polystyrene is effective, and the polymer is selected by selecting a polymer. The present inventors have found that it is possible to create and have completed the present invention.
    [16] In addition, it was found that such a retardation film can be laminated with other retardation films to control the retardation wavelength dispersion of other retardation films, and as a result, can contribute to the improvement of image quality of a liquid crystal display device.
    [17] That is, this invention is a retardation film which consists of one polymer film, Comprising: It has a wavelength band to which the retardation value is positive in wavelength 400-800 nm, and the wavelength band added, satisfy | fills at least one of following formula (1) and (2), Moreover, it is achieved by the retardation film whose water absorption is 1 mass% or less.
    [18] ┃R (400) ┃ ≥10 nm (1)
    [19] ┃R (700) ┃ ≥10 nm (2)
    [20] (Wherein, “R (400)” and “R (700)” are phase difference values at wavelengths of 400 nm and 700 nm)
    [21] It is estimated that the retardation film of this invention is based on the following principle. That is, if the phase difference value of the component having positive refractive index anisotropy and the phase difference value of the component having negative refractive index anisotropy completely cancel each other, the phase difference value is completely 0. Since the polymer has wavelength dispersion in birefringence, By adjusting the amount of components having anisotropy and the amount of components having negative refractive index anisotropy, the phase difference value becomes completely zero at any wavelength in the measurement wavelength range of 400 to 800 nm. In this way, it is considered that the phase difference value has a positive band and a negative band at the measurement wavelength of 400 to 800 nm.
    [149] Although an Example is given to the following and this invention is demonstrated in more detail, this invention is not limited to these.
    [150] (Evaluation method)
    [151] The material characteristic values described in this specification are obtained by the following evaluation methods.
    [152] (1) Measurement of phase difference value (Δn · d)
    [153] The retardation value which is the product of birefringence (Δn) and the film thickness (d) was measured by Nihon Bunko Co., Ltd. product name "M150" which is a spectroscopic ellipsometer.
    [154] (2) Measurement of proton NMR
    [155] Analysis of the copolymerization composition ratio of polycarbonate was performed using the proton NMR method. As the measurement solvent, heavy benzene was used, and Nippon Denshi "JNM-alpha600" was used as the apparatus.
    [156] (3) film thickness measurement
    [157] It measured by the electronic micrometer (meter) by Anritsu.
    [158] (4) measurement of water absorption
    [159] Except having made the film thickness 130 +/- 50 micrometer in the state of the dried film, it measured based on "The plastic absorption rate and the boiling absorption test method" of JIS K 7209. The size of a test piece is 50 mm square, 25 degreeC of water temperature, After submerging the sample for 24 hours, the weight change was measured. The unit is%.
    [160] (5) polycarbonate monomer
    [161] Moreover, the monomer structure of the polycarbonate used by the following example and the comparative example is described below.
    [162]
    [163]
    [164]
    [165]
    [166] Example 1
    [167] Aqueous sodium hydroxide solution and ion-exchanged water were added to a reaction tank equipped with a stirrer, a thermometer, and a reflux cooler, and monomers [A] and [D] having the above structure were dissolved in a molar ratio of Table 1, and a small amount of hydrosulfite and Added. Next, methylene chloride was added to this, and phosgene was blown in for about 60 minutes at 20 degreeC. Furthermore, after adding and emulsifying p-tert- butylphenol, triethylamine was added and stirred at 30 degreeC for about 3 hours, and reaction was complete | finished. After completion of the reaction, the organic phase was fractionated, and methylene chloride was evaporated to obtain a polycarbonate copolymer. The composition ratio of the obtained copolymer was almost the same as the monomer injection amount ratio.
    [168] This copolymer was dissolved in methylene chloride to prepare a dope solution having a solid content concentration of 20% by mass. A cast film having a thickness of 120 µm was prepared from this dope solution, and uniaxially stretched at a stretching temperature of 240 ° C. and 1.3 times to produce a retardation film having the film thickness, retardation value, retardation wavelength dispersion value, and water absorption in Table 1. 5 shows phase difference wavelength dispersion characteristics at measurement wavelengths of 400 to 700 nm. It was confirmed from Table 1 and FIG. 5 that the retardation wavelength dispersion value was 0 at 550 nm at the measurement wavelength of 400 to 700 nm, added at the short wavelength side, and positive at the long wavelength side.
    [169] In addition, the film is adhered to a commercially available polyvinyl alcohol through a pressure-sensitive adhesive such that each stretching axis is 45 ° to a polarizing film consisting of uniaxial stretching doped with iodine, and the retardation film is formed using another polarizing film. The color tone of this polarizing film was observed between these polarizing films and the arrangement of the polarizing film was cross nicol, but the color tone was changed in comparison with when the retardation film was not added. That is, it turned out that the color tone of a polarizing film can be changed subtly by the combination of a polarizing film and this retardation film.
    [170] Example 2
    [171] Polycarbonate copolymer was obtained by the same method as Example 1 except using the monomer of Table 1. The composition ratio of the obtained copolymer was almost the same as the monomer injection amount ratio. A retardation film was produced in the same manner as in Example 1. From Table 1, it was confirmed that the retardation wavelength dispersion value was added at the short wavelength side and positive at the long wavelength side at the measurement wavelength of 400 to 700 nm.
    [172] Example 3
    [173] Polycarbonate copolymer was obtained by the same method as Example 1 except using the monomer of Table 1. The composition ratio of the obtained copolymer was almost the same as the monomer injection amount ratio. A retardation film was produced in the same manner as in Example 1. From Table 1, it was confirmed that the retardation wavelength dispersion value was added at the short wavelength side and positive at the long wavelength side at the measurement wavelength of 400 to 700 nm.
    [174] Reference Example 1
    [175] The polycarbonate polymer was obtained by the same method as Example 1 except having used the monomer of Table 1. Using this, the retardation film was produced like Example 1 except having extended | stretched conditions to 160 degreeC and 1.1 times. This retardation film has positive refractive index anisotropy and has a phase difference dispersion value of Table 1.
    [176] Example 4
    [177] The retardation film produced in Example 1 and the retardation film of Reference Example 1 were adhered using an adhesive so that the stretching direction was parallel. Table 2 and FIG. 6 show retardation wavelength dispersion characteristics of the laminated retardation film. It was found that the laminated retardation film had a larger retardation on the longer wavelength side, and became a retardation film whose retardation became almost a quarter wavelength in a wide band.
    [178] In addition, this laminated retardation film and commercially available polarizing film (Sanritsu Co., Ltd. brand name "LLC2-9218") were adhered through an adhesive so that the absorption axis of a polarizing film and the slow axis of this retardation film may be 45 degrees. Remove the touch panel, polarizing film, and retardation film on the observer's side with respect to the liquid crystal layer of the portable information terminal (Sharp Co., Ltd. product name "Saulscalar Pocket MI-310") equipped with a reflective color liquid crystal display device. The film-integrated polarizing film was attached through an adhesive at an appropriate angle. When the portable information terminal was actually driven, it was found that the black display had no coloration and became a display device having excellent image quality.
    [179] Reference Example 2
    [180] The polycarbonate polymer was obtained by the same method as Example 1 except having used the monomer of Table 1. Using this, the retardation film was produced like Example 1 except having extended | stretched conditions to 161 degreeC and 1.2 times. This retardation film has positive refractive index anisotropy and has a phase difference dispersion value of Table 1.
    [181] Example 5
    [182] The polycarbonate copolymer was produced like Example 1 using the monomer of Table 1. The ratio of monomer [A] and [D] to 26:74 (mol%) means that the phase difference is negative on the short wavelength side and positive on the long wavelength side. Table 1 shows the phase difference dispersion values.
    [183] Example 6
    [184] The retardation film of Example 5 and the retardation film of Reference Example 2 were adhered using an adhesive so that the stretching direction was parallel. Table 2 shows the retardation wavelength dispersion characteristics of the laminated retardation film. It was found that this laminated retardation film became a retardation film having a smaller retardation on the longer wavelength side. This laminated retardation film has a preferable value of Δn · d (450) / Δn · d (550) of 1.18 and a high speed response super twist nematic liquid crystal display device having a large phase difference wavelength dispersion of the liquid crystal cell. Found to have.
    [185] Example 7
    [186] The methylene chloride dope solution of 20 mass% of solid content concentration was produced using 1.5 mass parts of saccharose octaacetate with respect to 98.5 mass parts of polycarbonate copolymerized in Example 1. From the dope solution, the cast film which has a thickness of 120 micrometers was produced, and the retardation film which has retardation wavelength dispersion value of Table 1 was produced by extending | stretching uniaxially at the draw ratio 1.2 time and the temperature of 240 degreeC. From Table 1, it was confirmed that the retardation wavelength dispersion value was added at the short wavelength side and positive at the long wavelength side at measurement wavelengths 400 to 800 nm. However, the retardation wavelength dispersion was different from that in Example 1.
    [187]
    [188]
    [189] [Comparative Examples 1 to 6]
    [190] The polycarbonate polymer was obtained by the method similar to Example 1 except having used all the monomer of Table 1. Using this, the retardation film was produced like Example 1. As can be seen from Table 3, it has been found that the phase difference values do not have bands in both the positive and negative sides at the measurement wavelength of 400 to 800 nm.
    [191]
    [192] Example 8
    [193] Polystyrene (Aldrich Chemicals catalog No. 18242-7) and Poly (2,6-dimethyl-1,4-phenylene oxide) (Aldrich Chemicals catalog No. 18178-1) were 66.5 mass% and 33.5 mass, respectively. It melt | dissolved in chloroform in the ratio used as% and prepared the dope solution of 18 mass% of solid content concentration. The cast film was produced from this dope solution, and uniaxially stretched by double temperature 130 degreeC.
    [194] The film thickness of this film was 90 nm, the phase difference value at a wavelength of 400 nm was 82 nm, the phase difference value at a wavelength of 700 nm was -18 nm, and the water absorption was 0.3 mass%. Table 4 shows phase difference values at three wavelengths and phase difference wavelength dispersion characteristics (R (450) / R (550), R (650) / R (r) with respect to the phase difference value (R (550 nm)) at a wavelength of 550 nm. 550)). 7 shows the phase difference wavelength dispersion characteristics graphically. It was found that this film was measured on the short wavelength side and added on the long wavelength side.
    [195] Example 9
    [196] Solution from dope solution obtained by polymerizing bisphenol A with phosgene with a viscosity average molecular weight of 38000 The polycarbonate film of thickness 100micrometer was produced by the casting method. This was uniaxially stretched by the draw temperature of 160 degreeC magnification 1.1 times, and the phase difference plate which has a positive phase difference value was obtained. The characteristic is shown in Table 4 and FIG. This retardation plate and the retardation plate of Example 8 were made to stick through an adhesive so that an extending direction might orthogonally cross. The phase difference wavelength dispersion characteristics of the laminated retardation plate are shown in Table 4 and FIG. 8 together. As for the laminated retardation plate, it was found that the stretching axis direction of the polycarbonate became the slow axis, and as shown in Fig. 8, the shorter the measurement wavelength, the smaller the phase difference was, and the quarter wave plate was almost a broadband.
    [197] This retarder is adhered so that the polarization axis of the commercially available polarizing plate and the slow axis of the retardation plate are 45 °, and the commercially available portable information terminal is equipped with a reflective liquid crystal display device. It was ground with a polarizing plate and a retardation plate. A liquid crystal display device excellent in image quality could be obtained.
    [198] Example 10
    [199] Solution from dope solution obtained by polymerizing bisphenol A with phosgene with a viscosity average molecular weight of 38000 The polycarbonate film of thickness 100micrometer was produced by the casting method. This was uniaxially stretched at 1.2 times the draw temperature of 162 degreeC, and the phase difference plate which has a positive phase difference value was obtained. The characteristic is shown in Table 4 and FIG. This retardation plate and the retardation plate of Example 8 were made to stick through an adhesive so that the extending | stretching direction might correspond. The phase difference wavelength dispersion characteristic of this laminated retardation plate was written together in Table 4 and FIG. In this laminated retardation plate, the stretching direction of the polycarbonate became the slow axis, and the retardation hardly changed at the measurement wavelength of 550 nm. However, it was found that the retardation became larger as the measurement wavelength was shorter than the polycarbonate retardation plate alone.
    [200] Comparative Example 7
    [201] Polystyrene and poly (2,6-dimethyl-1,4-phenylene oxide) used in Example 8 were dissolved in chloroform at a ratio of 80% by mass and 20% by mass, respectively, to prepare a dope solution having a solid concentration of 18% by mass. It was. The cast film was produced from this dope solution, and uniaxially stretched by temperature 130 degreeC and 1.7 time.
    [202] Table 4 describes the phase difference wavelength dispersion characteristics. It was found that this film became a negative retardation plate.
    [203] Comparative Example 8
    [204] Polystyrene and poly (2,6-dimethyl-1,4-phenylene oxide) used in Example 8 were dissolved in chloroform at a ratio of 60% by mass and 40% by mass, respectively, to prepare a dope solution having a solid concentration of 18% by mass. It was. The cast film was produced from this dope solution, and uniaxially stretched by 1.3 times of temperature 130 degreeC.
    [205] Table 4 describes the phase difference wavelength dispersion characteristics. It was found that this film became a positive retardation plate.
    [206]
    [207] PS / PPO: Polystyrene / Poly (2,6-dimethyl-1,4-phenylene oxide) blend
    [208] PC: Polycarbonate
    [209] As described above, the retardation film of the present invention has a band where the retardation value is positive and a band where the retardation value is positive at a measurement wavelength of 400 to 800 nm. Desired excellent visual compensation film, color compensation film, polarizing film, circular polarizing film, elliptical polarizing film, it can provide an effect such as a liquid crystal display device. Moreover, the retardation film which has especially excellent characteristic can be obtained by using the polymer film which consists of a polycarbonate copolymer and / or a blend body which have a fluorene skeleton as this retardation film material.
    权利要求:
    Claims (15)
    [1" claim-type="Currently amended] A retardation film composed of one polymer film, having a wavelength band in which a retardation value is positive at a wavelength of 400 to 800 nm and a wavelength band in which a negative value is formed, wherein at least one of the following formulas (1) and (2) is used: Retardation film which satisfy | fills and whose absorption rate is 1 mass% or less:
    [Equation 1] ┃R (400) ┃ ≥10 nm (1)
    [Equation 2] ┃R (700) ┃ ≥10 nm (2)
    (In formula, "R (400)" and "R (700)" are phase difference values in wavelength 400nm and 700nm).
    [2" claim-type="Currently amended] The phase difference film of Claim 1 which takes a negative phase difference value in wavelength 400nm, and takes a positive phase difference value in 800nm.
    [3" claim-type="Currently amended] The retardation film according to claim 1 or 2, wherein the polymer film is a polycarbonate film.
    [4" claim-type="Currently amended] 4. The retardation film of claim 3, wherein the polymer film is a polycarbonate film having a fluorene skeleton.
    [5" claim-type="Currently amended] The method of claim 4, wherein the polymer film is represented by the following Chemical Formula 3:
    [Formula 3]
    (In Formula 3, R One To R 8 Are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group of 1 to 6 carbon atoms, X is represented by the following formula 4:
    [Formula 4]
    to be)
    A repeating unit represented by the following Chemical Formula 5:
    [Formula 5]
    (In Formula 5, R 9 to R 16 are each independently selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 6 carbon atoms.)
    It consists of a polycarbonate consisting of a repeating unit represented by the formula, and the repeating unit represented by the formula (3) comprises 60 to 90 mol% of the entire polycarbonate, the repeating unit represented by the formula (5) occupies 40 to 10 mol% Retardation film.
    [6" claim-type="Currently amended] The phase difference film of Claim 1 which takes a positive phase difference value in wavelength 400nm, and takes a negative phase difference value in 800nm.
    [7" claim-type="Currently amended] The retardation film according to claim 1 or 6, wherein the polymer film is one polymer blend film composed of polyphenylene oxide and polystyrene.
    [8" claim-type="Currently amended] 8. The retardation film according to claim 7, wherein the polymer film is one polymer blend film composed of 39 to 25 mass% polyphenylene oxide and 61 to 75 mass% polystyrene.
    [9" claim-type="Currently amended] The retardation film according to any one of claims 1 to 8, wherein the polymer film further contains 20% by mass or less of a low molecular compound having optical anisotropy.
    [10" claim-type="Currently amended] The laminated retardation film in which the retardation film in any one of Claims 1-9 is made into a 1st retardation film, and a retardation value is positive or negative 2nd retardation film is laminated | stacked on this and wavelength 400-700 nm.
    [11" claim-type="Currently amended] The laminated retardation film according to claim 10, wherein the absolute value of the retardation value of the second retardation film is shorter on the shorter wavelength side.
    [12" claim-type="Currently amended] The laminated retardation film according to claim 10 or 11, wherein the retardation value at a wavelength of 550 nm is 1/4 wavelength.
    [13" claim-type="Currently amended] The retardation film integrated polarizing film formed by laminating | stacking the retardation film (including a laminated retardation film) and a polarizing film in any one of Claims 1-12.
    [14" claim-type="Currently amended] A liquid crystal display device using the retardation film (including a laminated retardation film) according to any one of claims 1 to 12.
    [15" claim-type="Currently amended] A liquid crystal display using the phase difference film integrated polarizing film according to claim 13.
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    同族专利:
    公开号 | 公开日
    CN1322303A|2001-11-14|
    EP1118885A4|2003-06-04|
    DE60008693D1|2004-04-08|
    WO2001009649A1|2001-02-08|
    US6638582B1|2003-10-28|
    EP1118885B1|2004-03-03|
    EP1118885A1|2001-07-25|
    DE60008693T2|2005-01-13|
    KR100474495B1|2005-03-08|
    CN1192256C|2005-03-09|
    TW520449B|2003-02-11|
    JP4010810B2|2007-11-21|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1999-07-29|Priority to JP99-214939
    1999-07-29|Priority to JP21493999
    2000-07-28|Application filed by 야스이 쇼사꾸, 데이진 가부시키가이샤
    2001-08-09|Publication of KR20010075435A
    2005-03-08|Application granted
    2005-03-08|Publication of KR100474495B1
    优先权:
    申请号 | 申请日 | 专利标题
    JP99-214939|1999-07-29|
    JP21493999|1999-07-29|
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