TW200928521A - Phase difference film and elliptical polarizing plate using the same - Google Patents

Abstract

Provided is a phase difference film formed of a laterally extended film of polypropylene resin, wherein the thickness is 25μ m or less, an in-plan phase difference value (R0) is within a range of 70 to 400nm, and an Nz coefficient which is defined by a general formula: Nz=(nx-nz)/(nx-ny) when nx is the refractive index in the direction of in-plan phase retardation axis of the film, ny is the refractive index in the direction of in-plan phase advancing axis of the film, and nz is the refractive index in the thickness direction is within a range of 0. 9 to 1. 1. The phase difference value is adjusted so that the phase difference film is functioned as a 1/4 wavelength plate 10. By laminating the phase difference film onto a linear polarizing plate 20, an elliptical polarizing plate 30 is obtained.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retardation film composed of a polypropylene resin and an elliptically polarizing plate using the retardation film. More specifically, it relates to a retardation film which can make a film thickness extremely thin, and an elliptical polarizer which is extremely thin in film thickness using the film. The present invention is also directed to a liquid crystal display device using the elliptically polarizing plate. [Prior Art] Ο ❹ In recent years, liquid crystal displays that consume low power, operate at low voltage, and are lightweight and thin have been rapidly popularized as information display devices such as mobile phones, mobile information terminals, computer monitors, and televisions. Along with the development of liquid crystal technology, liquid crystal displays or optical components of various modes have been proposed, and the response speed, contrast, viewing angle, and wide-band domain have been improved. _ In a reflective or transflective liquid crystal display represented by a mobile phone, etc., an elliptically polarizing plate is used, which is a retardation film that functions as a quarter-wave plate, or 1/4 The wavelength plate is combined with the 1⁄2 wavelength plate; the wide band is used as a retardation film that functions as a 1⁄4 wavelength plate, and is intended to be a low-profile optical polarizer. Such an elliptically polarizing plate, in particular, a circle =:=: a stop function 'in all applications, for the human eye to be clear, and all of the incident light expected to obtain ... can sufficiently suppress the good light-shielding performance of the internal counter-piece to j. In the retardation film, the difference between the wavelengths and the wavelength of the 1/4 wavelength plate is set, and the phase that functions as the 1/2 wavelength plate is used as the 1/4 320734 for the incident light in the wide wavelength region. 200928521 ^The so-called wide-band domain 1/4 wavelength plate function of the wavelength plate has been implemented since the past. For example, in Japanese Patent Laid-Open No. Hei 5-100114 (Patent Document υ, it has been disclosed that the combination is made of a polycarbonate film. An example of a 1⁄4 wavelength plate and a 1⁄2 wavelength plate. However, in a wide-band domain 1⁄4 wavelength plate using polycarbonate, it is necessary to function as a complete 174-wavelength plate at all wavelengths. Difficult, • Again, it is difficult to adequately control the internal reflection, and good shading performance is not obtained. Furthermore, the photoelastic coefficient of the polycarbonate film is as high as about 27xl (T13cm2/dyne, so it will be attached to the linear polarizer) There is a problem of unevenness of the bonding, or a white spot phenomenon in which the light of the backlight is partially leaked in the black display due to the change in the degree of use/inversion. Therefore, in the publication of "Kemoto Tekai Kai", No. 4,490,15 (Patent Document) 2) Medium 'disclosed: making the in-plane in the wavelength 4〇〇nm The difference between the maximum refractive index and the minimum refractive index (birefringence) Δη400, and the difference between the maximum refractive index and the minimum refractive index (birefringence) Δη500 in the plane at a wavelength of 500 nm (Δη4〇〇/Αη50〇) The 1/2 wavelength plate and the 1⁄4 wavelength plate group are not combined with each other. In the specific example (in the embodiment), the quarter-wave plate and the ring-shaped polyolefin resin film are respectively combined. /2-wavelength plate. The coefficient of photoelasticity of the cyclic polyolefin resin film is as small as about 4x10_13cm2/dyne, so it is effective in suppressing unevenness or white spot. But 'extend the polycarbonate film or the cyclic polyolefin resin film When the stretching ratio is too large, the in-plane retardation value becomes j because the film thickness is thinned. Therefore, in order to develop a desired phase difference value, a film of zinc must have a certain thickness to ensure its film thickness. However, it is not possible to respond to the requirements of thin film sought by the market. 320734 5 200928521 In addition, in polycarbonate or cyclic polyolefin resin, it is difficult to make a completely uniaxial retardation film by lateral stretching, and it has to rely on longitudinal stretching. Generally, in the longitudinal extension, the wide direction becomes the free end, and is extended. The film is produced by a neck-in, so that it is difficult to produce a film having a thin retardation film. Further, in recent years, in one of the methods of thin film formation, the coating appearance of a liquid crystal compound has been studied. However, when such a coating type retardation film is formed, the liquid crystal compound generally contains a liquid crystal precursor having an aromatic ring, so that the wavelength dispersion is positively dispersed or the alignment of the liquid crystal compound is caused. A single domain (m 〇η 〇 domain) suitable for the uniaxial alignment of the retardation film is difficult. Further, the drying step at the time of manufacture tends to cause uneven film thickness, and also has an in-plane phase difference. Reporting problems that are difficult to control. Therefore, the subject of the present invention is to provide a retardation film which is extremely thin and has a wavelength dispersion of a phase difference which is flat. When a quarter-wavelength plate and a 1/2 wavelength plate are combined to form a wide-band domain 1/4 wavelength The plate exhibits good light-shielding properties, and can solve the unevenness of the bonding or the 1/4 wavelength plate or the 1/2 wavelength plate including the uniaxial Q. Further, another object of the present invention is to provide a retardation film which is formed into a substantially complete mono-secret film, which is excellent in utilization efficiency. [Summary of the Invention] That is, (4) static ^, can provide - _ dislocation film, and then you are composed of a stretch film, and the thickness is 25 (four) or less, the surface S i: weight, range, and, when the film is within the retardation axis direction When the refractive index is ηχ, the refractive index of the in-plane phase-in-phase is 320734 6 200928521 ny, and the refractive index in the thickness direction is ηζ, the Nz coefficient defined by the formula: Nz=(nx-nz)/(nx-ny)范围范围内。 The range of 0.9 to 1.1. The polypropylene resin constituting the retardation film is preferably composed of a copolymer of propylene and ethylene containing 1 Å of the stolen ethylene unit. Further, it is preferable that the polypropylene resin is substantially composed of a propylene single polymer, and it is preferable that the polypropylene hang-hanging agent contains a nucleating agent. to make. The 相位 Ο The retardation film can adjust the in-plane retardation value to function as a long board. In addition, it is also possible to adjust the in-plane phase difference value to function as a wave wavelength plate. 1/2 According to the present invention, an elliptically polarizing plate which is formed by laminating an upper and a retardation film on a linear polarizing plate can be provided. Specifically, the retardation film which functions as a quarter-wave plate function in the example = laminated to linearly polarized light can form an ellips® polarizing plate. Further, the above-described 1/4 wavelength film is used to exhibit a phase difference from the above-described function of the 1/2 wavelength plate: Ling. And further linearly polarizing the 1/2 wavelength plate side to form an elliptically polarizing plate. j. Further, according to the present invention, it is also possible to provide a liquid crystal display, in which at least one of the above-mentioned elliptically polarizing plates is laminated and laminated to a liquid crystal cell. "The embodiment of the present invention will be described in detail below. L retardation film] In the present invention, a phase difference of 320734 7 200928521 is formed by a transversely stretched film of a polypropylene resin. Since the polypropylene resin film has crystallinity, the retardation value The rate of development is extremely high, and a large phase difference can be easily obtained by extension. Therefore, a phase difference film having a desired phase difference can be obtained with a thin film thickness. Also, since the polypropylene resin is at a wavelength of 4 The difference between the maximum refractive index and the minimum refractive index in the plane of 〇〇nm (birefringence) Δ“〇〇, the difference between the maximum refractive index and the minimum refractive index in the plane at the wavelength 5〇〇nm′ (double The ratio of refracting ΔΜΟΟ (Δι^ΟΟ/Δη500) is less than 1·〇5, so a 1⁄2 wavelength plate made of a polypropylene resin and a 1⁄4 wavelength plate are combined to form a wide band 1 When the /4 wavelength plate is used, excellent light shielding performance can be obtained. In the present specification, the wavelength dispersion of the phase difference is defined by the value of Δη400/Δη500 described above. It is also called "wavelength dispersion". Furthermore, the photoelastic coefficient of the polypropylene resin is as small as 2U0-W/dyne', so that when the 1/2 wavelength plate and the 1/4 wavelength plate are attached, or when laminated to a linear polarizing plate, uneven bonding can be suppressed. Or white spots. It has also been found that since the polypropylene resin can be stretched at a 咼 magnification, it is possible to produce a completely uniaxial ruthenium film by lateral stretching. Thereby, it can be simultaneously thinned and broadened, and the utilization efficiency is excellent. The material film formed from the film made of such a polypropylene resin was laterally stretched to exhibit a phase difference. At this time, the film thickness of the retardation film can be made 25 μm or less. The film thickness is preferably 20/zm or less. If the film thickness exceeds 25 #m, the advantage of thin film formation is difficult to effectively exert. Further, if the film thickness is too small, wrinkles are likely to occur in the film, and the handling property at the time of winding or bonding tends to deteriorate. Therefore, it is preferable that the film thickness is preferably "above". When the refractive index of the in-plane axis of the film is ηχ, the in-plane phase axis direction (the direction orthogonal to the retardation axis in the plane) is ny, and the thickness is 320734 8 200928521. When nz and the thickness d, the in-plane phase difference (Ro), the thickness direction phase difference (Rth), and the Nz coefficient are defined by the following formulas (I), (II), and (III), respectively. Ro=(nx-ny)xd (I) Rth=[(nx+ny)/2-nz]xd (II) Nz=(nx-nz)/(nx-ny) (III) Again, from this (I), (II), and (III), the relationship between the Nz coefficient and the phase difference (Ro) in the plane and the phase difference (Rth) in the thickness direction can be expressed by the following formula (IV).

Nz = Rth / Ro + 0.5 (IV) In the retardation film of the present invention, the in-plane phase difference (Ro) is in the range of 70 to 400 nm, particularly preferably in the range of 80 to 330 nm. The phase difference (Rth) in the thickness direction is preferably in the range of 28 to 240 nm.范围范围内。 The range of 0. 9 to 1. 05, especially in the range of 0.95 to 1. 05. As long as the range is within the range, the characteristics required for the liquid crystal display device to be applied can be matched, and φ can be appropriately selected. Here, if the Nz coefficient is about 1, it means that ny and nz are approximately equal in the above formula (III), and such a retardation film is a uniaxial property in which the drum is completely uniaxial. [Polypropylene tree] The polypropylene resin constituting the retardation film of the present invention is a single polymer of propylene or a copolymer of propylene and another copolymerizable comonomer. The propylene alone polymer has a higher degree of crystallization than the copolymer of propylene and other copolymerized comonomers, so that the film rigidity and the lodging strength can be further improved. Therefore, by forming a retardation film from a single polymer of propylene, the retardation film can be further improved. The process of the production step, the polarizing plate forming step, and the bonding step with τν can be further improved. The polypropylene resin constituting the retardation film of the present invention can be produced by a method of separately polymerizing propylene using a known polymerization catalyst, or a method of copolymerizing propylene with another co-combination comonomer. The known catalyst for polymerization can be exemplified by the following. (1) Ti-Mg-based catalyst composed of a solid catalyst component containing magnesium, titanium, and dentate as essential components; (2) in a solid catalyst component containing magnesium, titanium, and i as essential components 'A catalyst system that combines an organic compound and a third component such as an electron-donating compound as needed; (3) A single-site polymerization catalyst (Metan〇cene) is a catalyst. Among these catalyst systems, in the manufacture of the polypropylene resin used in the retardation film of the present invention, the most common ones can be used in solid catalyst components containing iron, titanium and dentate as essential components. , combined with organoaluminum compounds and electrons supplied with |± compounds. More specifically, the organic compound is preferably, for example, a triethyl sulfonate, a 4-year-old, a tetrabutylamine, a triethylamine, and a vaporized diethyl &alumoxane; Electronic supply and sex; soldiers = better? For example, cyclohexylethyldimethoxy-xanthene, a third ring-oxycarbonyl group, a tert-butylethyldimethoxy-wei, a decyl-monomethoxy group or the like can be mentioned. Ingredient 2:::Antimony, titanium and a solid element as a necessary component of the solid catalyst 61-2_4t^ This special open (4) fine 6th bulletin, Japan's special open Japan (4) flat 7-2_7 public « note early aggregation touch The catalyst system described in, for example, Japanese Patent No. 320734 10 200928521 2587251, Japanese Patent No. 2627669, and Japanese Patent No. 2668732. The polypropylene resin can be produced by using a hydrocarbon compound such as hexane, heptane, octane, decane, cyclohexane, nonylcyclohexane, benzene, toluene or diphenyl. A solution polymerization method using a solvent; a bulk polymerization method using a liquid monomer as a solvent; a gas phase polymerization method in which a monomer of a gas is directly polymerized. The polymerization system can be carried out in batches or in a continuous manner. ® The stereoregularity of polypropylene resin can also be any of isotactic, syndiotactic, and atactic. In the present invention, it is preferred to use a polypropylene resin in a row or in the same row from the point of heat resistance. The polypropylene resin used in the present invention may be composed of a single polymer of propylene, or may be propylene as a main component and a small amount (for example, 20% by weight or less, preferably 10% by weight) of the comonomer copolymerizable therewith. % below) the ratio of the co-aggregators. When the copolymerization is carried out, the amount of the comonomer is preferably 1% by weight or more. The co-monomer copolymerized with propylene may be, for example, ethylene or an α-olefin having 4 to 20 carbon atoms. Specifically, the α-olefin at this time may, for example, be the following. 1-butene, 2-methyl-1-propene (above C4); 1-pentene, 2-mercapto-1-butene, 3-mercapto-1-butene (above C5); Dilute, 2_ethyl-1_丁妇, 2,3_dimercapto-1_butylene, 2-mercapto-1-decene, 3-mercapto-1-pentene, 4-methyl- 1-pentene, 3, 3-dimercapto-1-dean (above C6); 11 320734 200928521 1 - heptano, 2~methyl + hexene, 2,3_m-nonene, 2_ethyl- 1-pentene, 2-methyl-3__ethylbutene (above C7), · 1_octane, 5~methyl + heptene, 2-ethyl-1-hexene, 3,3_2 Methyl 1 hexene 2 methyl, 3-ethyl-p-pentene, 2 3 4-trimethyl-p-pentene, 2-propyl-1-pentanyl, 23-diethyl-butadiene Above (8);

1-decene (C9); decimene (cl〇); b-undecene (cii); 卜12 olefin (C12); 1-trifluorocarbon (C13); c(4): b-pentadecene (C15) 'b-hexadecene (G16); b-seven-carbon ruthenium (c(7); 1-octadecene (C18); 1-19-nonene) "", etc. Preferred among the olefins are the hydrocarbon-olefins having a carbon number of 4 to 12, and specific examples thereof include 1-butane, 2-f-based propylene, pentylene, 2-methyl-1-butene, and 3 -Methyl+Butane; Buhexium, 2_Ethyl+Butane, 2,3-Dimethyl-P-butene, 2-Methyl+Pentene, 3-Methyl+Pentene, 4-Methyl -1-pentene, 3,3-dimethyl-butene; i-heptene, 2-methyl+hexene, 2,3-mercapto-1 pentene, 2-ethyl-p-pentene, 2_Methyl-3-ethyl-Bu Ding, 1 Xin, Bu-M-Heptene, 2-Ethyl-1-hexyl, 3 3_: Methyl-Bhexene, 2-Methyl+B Base + pentacene, 23,4_trimethyl-p-pentene: 2-propyl-1 -pentanyl, 2,3-diethyl+butene; 壬 壬.; 癸 ' ' l- 十 - Carbene; p-dodecene material ^ from the viewpoint of copolymerization, more is 1 butene, pentene, hexene and The alkene is particularly preferably dibutyl and 1-hexacene. The copolymer may be a random copolymer or a block copolymer. Preferred copolymers are, for example, propylene/ethylene copolymer or propylene/卜丁妇 copolymer. In the propylene/ethylene copolymer or propylene/1-butan copolymer 320734 12 200928521 w, for example, by the method described in the r Polymer Analysis Manual (1995, Kiyokiya VII, p. 616) The infrared (Ir) spectrum is used to determine the content of the ethylene unit or the content of the 1-butene unit. • The viewpoint of transparency and workability of the retardation film is determined by the choice of peasene as the main body. Random copolymerization of unsaturated hydrocarbons and copolymerization with ethylene. When forming a copolymer, propylene is not saturated with saturated copolymers so that the copolymerization ratio is about 5% by weight. The ratio is from 3 to 7% by weight, and the propylene has a tendency to improve workability or clarity by using seven or more hydrocarbon units. In addition, if the ratio exceeds 1% by weight, Resin melting point reduces 'heat resistance In the case where a copolymer of two or more kinds of comonomers and polypropylene is used, the total amount of units derived from all the comonomers contained in the copolymer is preferably in the above range. The polypropylene resin used in the retardation film of the present invention is based on JIS K7210', and has a melt flow rate ❹ (MFR) measured at a temperature of 23 (rc, load 21.18 N) of from 1 to 200 g/l , minute, in particular, It is preferably in the range of 5 to 5 〇g / 1 〇 minutes. By using a polypropylene resin having an MFR in this range, a uniform film can be obtained without applying a large load to the extruder. The range of the effect of the present invention, the absorbing agent, the antistatic agent, the slip agent, the nucleating agent, the chemical agent, and the (4) wire absorbing antioxidant may, for example, be a phenolic antioxidant or an agglomerate. Agents and the like: antioxidants, amine-blocking stabilizers, and the like, and sulphur-based oxidants, for example, and mechanisms 320730 13 200928521 ultraviolet absorbers such as 2-perylene dibenzotriene, 'ultraviolet (four) agents, The benzoic acid static electrostatic agent may also be a polymer type, a polymer of a higher fatty acid guanamine, a higher fatty acid such as stearic acid, and a == agglomerating agent in the form of spherical or spheroidal particles, which can be used. . These additives may also be used in combination with multiple types:

G The nucleating agent used in the present invention may be any of an inorganic nucleating agent and an organic nucleating agent. Examples of the inorganic nucleating agent include talc and clay 俨. Further, the organic nucleating agent may, for example, be a metal salt of an aromatic acid or a dicarboxylic acid; a metal salt such as a metal salt filled with an acid, a high-density polyethylene, or a poly-cable Keding thin - Bu Polycyclic, polyvinylcyclohexyl. Among these, the organic nucleating agent' is more preferably the aforementioned metal salt and high-density polyethylene. Further, the nucleating agent is preferably added to the polypropylene resin in an amount of from 0 to 3 parts by weight, preferably from 0.05 to 1.5 (% by weight). The above additives may also be plural. [Original material film of polypropylene resin] The polypropylene resin can be formed into a film by any method. The raw material film is transparent and substantially free of in-plane retardation. For example, it is possible to obtain a substantially no-in-plane method by a method of extruding a molten lion; a method of forming a film by transferring a resin rot on an organic solvent to a flat plate and removing the solvent to form a film; Raw material film of polypropylene resin with phase difference. As an example of a method for producing a raw material film, a film forming method for extrusion molding is described in detail. The polypropylene resin was melted and kneaded by a screw in an extruder, and extruded from a T die into a sheet shape. The melted flakes = 320734 14 200928521 The temperature of the flakes is about 180 to 300 〇C. If the temperature of the molten flakes at this time is lowered to 18 (Tc, the ductility is insufficient, and the thickness of the obtained film becomes uneven), it may become a film having a phase difference unevenness. Further, if the temperature exceeds 3 〇 (TC, easily causes deterioration or decomposition of the resin, * generates bubbles in the sheet, or contains carbides. The extruder can be a single-axis extruder or a two-axis extruder. For example,

In the case of a uniaxial extruder, the ratio of the length L of the screw to the diameter d, that is, l/D Ο is about 24 to 36, which is the space volume of the thread groove in the resin supply portion, - and the thread in the resin metering portion. The ratio of the space volume of the groove (the former/the latter) is about 1.5 to 4, and a fuii fight type, a barrier type, or a mixed type of the Maddock type may be used. Screw. The barrier-type screw having a compression ratio of 2.5 to 3.5, and a compression ratio of 2.5 to 3.5, is preferably used. Further, in order to effectively suppress the deterioration or decomposition of the polypropylene resin, it is preferable to form a nitrogen atmosphere or a true enthalpy in the extruder, and to remove the volatile gas generated by the deterioration or decomposition of the I propylene resin, it is preferable to use the extruder. The front end is provided with micropores of lmm0 or more and 5 mm or less, and the resin pressure of the front end portion of the extruder is increased. Increasing the resin pressure at the tip end portion of the microporous extruder means that the back pressure of the tip end is increased, whereby the straight scale of the micropores used for improving the stability of the extrusion 9 is preferably 2 mm0 or less. The T-die used in the extrusion is suitable for the surface of the resin with poor surface or scratches, and the lip portion is preferably plated or coated with a material having a small coefficient of friction with the molten polypropylene: , further ~ 2 trees 32 〇 734 15 200928521 = 丨 anvil into a 〇. 3 coffee 0 below the sharp edge shape. The friction system may be used, for example, a special type of carbonization or fluorine-based plating. By, for example, 槿^ τ_ ' can suppress the generation of ocular effluent, and at the same time, the stencil line can be suppressed, so that a resin film having an excellent uniform appearance can be obtained. The branch pipe of the τ die is preferably in the shape of a hanger, and satisfies the condition (1) or (2) of τ, and more preferably satisfies the condition (3) or (4). Degree >180mm ...(1) When the lip width of the T die is 1500fflm or more; T degree >220mm; the height direction of the T die Ο τ The lip width of the die is less than 15〇〇mm; The thickness direction of the die is 180 mm (1) The thickness of the die is long. The lip width of the die is less than 1500 mm. 250 mm (3) The lip width of the T die is 15 When the 〇〇匪 is above; the height of the τ die is 280 mm (4) By using a T die that satisfies such conditions, the flow of the molten polypropylene resin inside the T die can be performed. By rectifying, even if the lip blade is used, it is possible to suppress the thickness unevenness and perform the extrusion. Thus, a raw material film having excellent thickness precision and uniform phase difference can be obtained. From the viewpoint of suppressing the change in the extrusion of the polypropylene resin, it is preferable to mount a gear pump between the extruder and the T die via a joint. Further, in order to remove foreign matter located in the polypropylene resin, a leaf disk filter is preferably installed. The molten sheet extruded from the T die is held by a metal cooling roll (also known as a chill roll (chi 11 roller) or a casting roll (casting 320734 16 200928521 .r°ller)), and is connected to the gold The film is rotated in the circumferential direction of the cold and contains the elastic contact roller, and is cooled and solidified to obtain the film. In this case, the contact roller may be formed by directly coating an elastic body such as rubber, or the surface of the elastomer roller may be made of a metal sleeve. The surface of the elastic _ is made of a metal sleeve: When the contact roller is coated, it is generally cooled between the metal cooling light and the contact light, and directly smashes the molten sheet of the polypropylene resin to be cooled. On the other hand, when a contact roll having an elastic surface is used, a biaxially stretched film of a thermoplastic resin may be interposed between the molten sheet and the contact roll. ❹ When the polypropylene resin sheet is cooled and solidified by the cold water and the contact roller as described above, both the cooling roll and the contact roll must be previously lowered in surface temperature to rapidly cool the molten sheet. . For example, the surface temperature of the two rolls should be adjusted to above 30. 〇 The following range. If the surface temperature exceeds 3 (rc, the cooling and solidification time of the molten sheet is delayed, the crystal component in the polypropylene sap will grow, and the obtained film may have transparency f. The surface temperature of the roll is preferably The system is less than 3 (TC, more preferably less than 25. Ϊ. If the surface temperature is lower than 〇 ° C, the surface of the metal chill roll is attached with water droplets, and the appearance of the film is deteriorated. tendency.

The surface state of the metal chill roll used for 膣ϋί is transferred to the polypropylene tree surface, so that when the surface has irregularities, the thickness accuracy of the obtained film may be lowered. Therefore, the surface of the metal chill roll should be as good as two gentlemen: mirror state. Specifically, the standard number of surface roughness of the metal cooling roll is expressed by a standard number of lines, preferably G. 3S or less, more preferably 〇. 1S 320734 17 200928521 ^ to 0.2S. • For the contact with the nip portion of the metal chill roll, the surface hardness in the elastomer is the value measured by the elastic hardness test (A shape) specified in JIS K6301. It is preferably 65 to 80, more preferably 70 to 80 °. By using such a rubber roller having a surface hardness, the chain pressure applied to the molten sheet can be easily and uniformly maintained, and the roll and the contact in the metal refrigerating portion are light. A stagnation bank (bank; tree stagnation) which does not produce a molten sheet is formed, and a film is easily formed. The pressure (linear pressure) at the time of rolling the molten sheet is determined by pressing the contact roller against the pressure of the metal refrigerating section roll. The line pressure system is preferably 50 N/cm or more and 3 〇〇 N/cm or less. More preferably, it is 1OO/cm or more and 250 N/cm or less. By setting the linear pressure to the above range, a polypropylene resin film can be easily produced while maintaining a constant line pressure without forming a stagnant bank. When the molten sheet of the polypropylene resin and the biaxially stretched film of the thermoplastic resin are pressed between the metal cooling roll and the contact roll, the thermoplastic resin constituting the biaxially stretched stretched film is not strong with the polypropylene resin. The resin to be geothermally welded can be specifically mentioned, for example, polyester, polyamine, polyglycolized ethylene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacrylonitrile or the like. Among these, it is most preferable that the polyester has a small dimensional change due to temperature or heat. The thickness of the biaxially stretched film at this time is generally about 5 to 50 #m, preferably about 1 to 30 /zm °. In this method, it is preferable to make the lip from the T die to the metal cooling roller and the contact roller. The distance of the rolling (air gap) is 2 〇〇 or less, and it is more preferably set to 160 mm or less. The molten flakes extruded from the τ die are stretched from the lips 320734 18 200928521 to the rolls, and are easily aligned. #由如, can get a smaller film. The lower limit of the air gap is determined by the shape of the front end of the diameter of the cooling roller used in the gold >1, and is generally 5 or more. The lip used in the production of the polypropylene resin film in this way is determined by the time required to broadly cure the molten sheet. 7

❹ m diameter becomes large. Since the molten flakes are connected to the chill roll, it is possible to produce a metal chill roll at a higher speed, and the jade speed is at most 5 to 2 Gm/min left:. = The rolled line of the rolled wire between the metal cooling roll and the contact roll is cooled (four) by pure contact. Further, as needed, a m-capture:r machine is wound up at the end to form a film. In this case, the surface of the film is "four", and the surface of the (4) (four) sheet of the polypropylene resin may be taken up in a state in which the surface protective film composed of a thermoplastic resin is bonded to one side or both sides. In the case where the stretched film is pressed together between the metal cooling roll and the contact roll, the biaxially stretched film may be formed into one surface protection thinner. [Manufacturing method of retardation film] The retardation film of the present invention can be produced by laterally stretching a raw material film composed of the above-mentioned polypropylene-based resin. Here, the lateral extension is a case where the long film rolled out from the light is extended in the width direction (lateral direction). 'Horizontal extension generally has the following steps. (A) a preheating step of preheating the raw material film with a preheating temperature near the melting point of the polypropylene resin; 320734 19 200928521 * (Β) for the preheated film at a temperature lower than the aforementioned preheating temperature An extension step of extending the temperature in the lateral direction; and (C) a heat-fixing step of thermally fixing the film extending in the lateral direction.代表性 Representative method of lateral stretching may be, for example, a stretcher method. The tensioner method is a method of extending the gap between the ends of the raw material in the width direction of the film by a chuck to widen the gap between the chucks. The extension machine (stretcher extension machine) used in the tensor method generally has an area in which the preheating step is performed, an area where the stretching step is performed, and a step of performing the heat fixing step, and the individual can be independently adjusted. The mechanism of temperature. By performing the lateral stretching using the two-stretcher stretching machine, a retardation film having excellent axial precision and a uniform phase difference can be obtained. The step of preheating the lateral extension is a step before the step of extending the crucible in the lateral direction, which is a step of heating the membrane to a sufficient temperature for extending the crucible. The preheating temperature of the preheating step means the ambient temperature in the region where the preheating step of the oven is carried out, and the temperature of the crucible near the melting point of the stretched polypropylene resin film is used. The residence time in the preheating step of the stretched film is preferably from 3 Torr to 120 seconds. When the residence time in the preheating step is less than 30 seconds, stress is dispersed when the film is extended in the stretching step, and the possibility of adversely affecting the axial precision or phase difference uniformity of the retardation film is When the residence time exceeds 120 seconds, it is heated to more than necessary, and there is a possibility that the film will partially melt and hang down (sagging). The residence time in the preheating step is preferably from 30 to 60 seconds. The step of extending the lateral extension is a step of extending the film in the width direction. The extension temperature in this extension step is generally a temperature lower than the preheating temperature. Extension step 20 320734 200928521 The extension temperature of the step (4) The residual line is extended (4) (4) The ambient temperature in the domain. By extending the film to the temperature of the step-like temperature, the film can be uniformly stretched, and as a result, a phase difference film excellent in uniformity of the optical axis and the phase difference can be obtained. The extension temperature should be 5 to m lower than the preheating temperature in the step, and more preferably 7 to 15 t lower. In this case, the stretching ratio is appropriately selected from the range of about 3 to 10 times in the direction in which the direction of the preceding axis (the direction of the late phase _ direction) is matched, and preferably 3 to 6 times. By making the stretching ratio at this time 3 times or more, the aforementioned Nz coefficient can be a range of u to ι·丨, and if the stretching ratio is too large, the uniformity of the phase difference may be impaired. Stop at around ig. The laterally extending heat-fixing step is a step of maintaining the film width at the end of the stretching step as a step of passing the film through a predetermined temperature in the oven. In order to effectively improve the phase difference of the film or the stability of the optical characteristics such as the optical axis, the heat setting temperature is preferably in a range from a temperature lower than the extension temperature of the stretching step to a temperature higher than the stretching temperature by 3 °C. ☆ The step of lateral extension may further have a heat relaxation step. The heat relaxation step ‘ is generally performed between the stretching step and the heat fixing step in the & tensor method, and is generally set such that the heat-relaxed region can be independently set with other regions. Specifically, the heat relaxation step is such that after the film is extended to a predetermined width in the stretching step, the interval of the chuck is narrowed by several % in order to remove unnecessary stress, and the interval is generally narrower than when the stretching is terminated. To about 7%. [Optical characteristics when used as a wavelength plate] When the retardation film of the present invention is used as a quarter-wave plate, the in-plane phase 320734 21 200928521 difference (Ro) is preferably in the range of 70 to 160 nm, more preferably The range of 8〇 to 15〇nm. The quarter-wavelength plate system has a function of converting light incident by linearly polarized light into elliptically polarized light including circularly polarized light, or converting light incident by elliptically polarized light including circularly polarized light into linearly polarized light and emitting the light. On the other hand, when the retardation film of the present invention is used as the 1/2 wavelength plate, the in-plane retardation value (Ro) is preferably in the range of 240 to 400 nm, more preferably in the range of 26 Å to 330 nm. The 1/2 wavelength plate has a function of rotating the direction of linear polarization. ❹[Flip polarizer] can be formed by laminating a quarter-wavelength plate with a linear polarizing plate at a predetermined axial angle, or laminating with a linear polarizing plate at a predetermined axial angle simultaneously with a 1⁄2 wavelength plate. Elliptical polarizer. 1 is a view showing a relationship between a cross-sectional view showing a layer structure and a shaft angle in an embodiment of an elliptically polarizing plate of the present invention. FIG. 2 is a view showing another embodiment of the elliptically polarizing plate of the present invention. A schematic diagram of the cross-sectional view of the layer structure and the relationship between the axial angles ❹. Referring to Fig. 1 (A), in one aspect of the present invention, a quarter-wavelength plate 1 made of the above-mentioned polypropylene resin film is laminated on the linear polarizing plate 20 to form an elliptically polarizing plate 30. . In this case, referring to Fig. 1(B), the counterclockwise direction is positive with respect to the absorption axis 22 of the linearly polarizing plate 20, and the angle 0 of the in-plane slow axis 12 reaching the quarter-wavelength plate 10 becomes The configuration is performed in a manner of 4 to 5 degrees (preferably about 45 degrees), thereby having a function of a substantially circular polarizing plate. Alternatively, based on the absorption axis 22 of the linear polarizing plate 2, the counterclockwise direction is positive, so that the angle θ of the in-plane slow axis 12 reaching the quarter wave plate 320734 22 200928521 becomes i3 〇 to 14 〇. It is preferably arranged in such a manner as to be approximately 135 degrees, thereby having a substantially circular polarizing plate function. Hereinafter, when the angle is expressed, the counterclockwise direction is positive with respect to the reference axis as described herein. Further, referring to Fig. 2 (Α), in another aspect of the present invention, the 1/4 wavelength plate 1 () and the 1/2 wavelength plate 15 layers composed of the above-mentioned polypropylene resin film are separated. Further, the linear polarizing plate 20 is further laminated on the side of the 1⁄2 wavelength plate 15 to form the elliptically polarizing plate 35. In this case, referring to FIG. 2 (Β) ' with the absorption axis 22 of the linear polarizing plate 20 as a reference, the angle $ of the in-plane slow axis π reaching the half-wavelength plate 15 is 1 〇 to 2 〇. (preferably, about 15 degrees) 'The angle ψ of the in-plane slow axis 12 from the in-plane phase axis 17 of the 1 / 2 wavelength plate 15 to the 1/4 wavelength plate 10 is 55 to 65 degrees (preferably It is configured in such a manner as to be approximately 60 degrees), so that it has a function of a substantially circular polarizing plate. Alternatively, the angle 0 of the in-plane retardation axis π of the half-wavelength plate 15 is set to 1 〇〇❹ to 110 degrees with respect to the absorption axis 22 of the linear polarizing plate 2 ( (preferably about 1 〇) 5 degrees), the angle 诅 of the in-plane slow axis 12 from the in-plane slow phase axis 17 to the quarter-wavelength plate 1 of the 丨/2-wavelength plate 15 is 55 to 65 degrees (preferably about 60 degrees) The way it is configured, it still has the function of being a circular polarizer. The relationship of the latter (from the absorption axis of the linear polarizing plate to the angle of the slow phase axis in the plane of the 1/2 wavelength plate is 1 〇〇 to 110 degrees) is equivalent to the rewriting of the symbol 22 in Fig. 2 (Β) It is the state of the "transparent axis of the linear polarizer". In the linear polarizing plate, the absorption axis and the transmission axis are orthogonal to each other in the plane. As shown in Fig. 2, the 1⁄4 wavelength plate 10 and the 1⁄2 wavelength plate 15 320734 23 200928521 are laminated to the wide-wavelength 1/4 wavelength plate in the visible light region, and 1/2 of them are used. The wavelength Å, the wide band, and the elliptically polarizing plate 35 as the plate 20 are connected to a wide band: =: linearly polarized light, or converted into circularly polarized light. In addition, it can be changed into a circular deviation. • The angle dependence of the reflection prevention effect can also be reduced.直线 地 • • • • • • • • • • • • 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线 直线Domain line board. By displacing the dichroic dye to the polyethylene, the linear polarization can be applied to: absorb the straight line of the vibration surface having a certain direction, and the straight line of the vibration surface having the direction orthogonal thereto = first For the coloring pigment system, a moth or a dichroic organic dye can be used. By the method of the two-color post-treatment, it is possible to obtain the dyeing of the color-developing pigment and the dyeing::: 2. The transparent protective layer is, for example. A cyclic polyolefin resin represented by the conventional protective layer of tridecyl cellulose (two === 醯 ,, _膜 constitutes t _' ba borneol resin, and polypropylene resin It is composed of a film of polyfluorene, poly(methyl acrylate), etc. When an ellipsoid is produced, the eucalyptus is at the wavelength plate, and the α/4 wavelength plate between the wavelength plates is 1/ 2 wave plate) = For example, use 24 320734 200928521 sensible adhesive (adhesive). Pressure-sensitive adhesives are preferably made of acrylic polymer with excellent transparency and durability. Pressure-sensitive adhesive layer The thickness system is generally in the range of 5 to 50/zm. As described above, the elliptically polarizing plate 30, 35 series can be 1/4 wavelength • A pressure-sensitive adhesive (adhesive) is disposed on the surface side of the board 10 so that it can be attached to a liquid crystal cell. The elliptical polarizer is laminated on at least one of the liquid crystal cells. On the side, the liquid crystal display device is configured. The elliptically polarizing plate can be disposed on both sides of the liquid crystal cell, and the elliptically polarizing plate can be disposed on one side of the liquid crystal cell, and the other polarizing plate can be disposed on the other side. In the case of the 1/4 wavelength plate 10, the liquid crystal display device is arranged on the side of the liquid crystal cell. [Liquid crystal display device] The ellipses of the present invention are arranged on both sides of the liquid crystal cell in a schematic cross-sectional view in FIGS. 3 and 4, respectively. Example of the liquid crystal display device of the panel. Fig. 3 is a view showing that the elliptically polarizing plate 30 which is a laminate of the quarter-wavelength plate 10 and the linear polarizing plate 20 shown in Fig. 1(A) is disposed in the liquid crystal cell 50 ^ For example, in this example, an elliptically polarizing plate composed of a quarter-wavelength plate 10/linear polarizing plate 20 is provided on the lower side of the liquid crystal cell 50 via the pressure-sensitive adhesive layer 40. 30 is laminated such that the side surface of the 1⁄4 wavelength plate 10 is directed to the liquid crystal cell 50, On the upper side of the liquid crystal cell 60, the elliptically polarizing plate 30 composed of the 1⁄4 wavelength plate 10 / the linear polarizing plate 20 is placed on the liquid crystal cell 50 by the side surface of the 1⁄4 wavelength plate 1 through the pressure sensitive adhesive layer 40. The elliptically polarizing plates 30 are arranged such that the absorption axes of the linear polarizing plates 20 are orthogonal to each other. When the liquid crystal display device is used as a penetrating plastic or semi-transparent reflection type, The backlight 60 is disposed on the outer side (the lower side in the figure) of one of the elliptically polarizing plates 25 320734 200928521. ' Fig. 4 shows a 174-wavelength plate 10 and a 1/2 wavelength plate which will be shown in Fig. 2(A) An example in which the elliptically polarizing plate 35 of the laminate with the linear polarizing plate 20 is disposed on both sides of the liquid crystal cell 50. That is, in this example, an ellipse composed of a quarter-wavelength plate • 10/1/2 wavelength plate 15/linear polarizing plate 20 is provided on the lower side of the liquid crystal* unit 50 via the pressure-sensitive adhesive layer 40. The polarizing plate 35 is laminated such that the side surface of the 1/4 wavelength plate 10 faces the liquid crystal cell 50, and also on the upper side of the liquid crystal cell 50, via the pressure sensitive adhesive layer 40, so that the 1/4 wavelength plate 10 is used. The elliptically polarizing plate 35 composed of the /1/2 wavelength plate 15/linear polarizing plate 20 is laminated such that the side surface of the quarter-wavelength plate 10 faces the liquid crystal cell 50. Each of the elliptically polarizing plates 35 is disposed such that the absorption axes of the linear polarizing plates 20 are orthogonal to each other. When the liquid crystal display device is used as a transmissive type or a transflective type, the backlight 60 is disposed on the outer side (the lower side in the figure) of one of the elliptically polarizing plates. The invention will be more specifically described below by showing examples, but the invention is not limited by the examples. In the examples, the % content is based on weight unless otherwise specified. [Example 1] (a) Preparation of a 1/4 wavelength plate A film of a propylene/ethylene random copolymer containing about 5% of an ethylene unit [Sumitomo Noblen W151" sold by Sumitomo Chemical Co., Ltd. was formed to obtain a thick film. 40/zm raw film. The raw material film is stretched toward the horizontal uniaxial axis by a stretcher transverse stretcher. The extension is at a line speed of 1 〇 m / min, first through the temperature is adjusted to 131 ° C in the preheating zone, and then the temperature is adjusted to i21 ° C extension 26 320734 200928521 area to make the final extension ratio measuring machine (share) The phase difference of the system is made, and the method of '° is used. The in-plane phase difference value 1^ of the difference Rth N r target film was measured by the odometer differential measuring device "K0BRA-21ADH". , the thickness direction phase, the digital micrometer "MH, 15m,, measured degrees, the result shows the wire = medium. The phase difference film of the phase difference film / μ internal phase difference R 〇 is 14 〇 nm, as The 1/4 wavelength plate functions as a function.

(b) Preparation of ellipsoidal polarizer The following linear polarizing plate [SR-W062" sold by Sumitomo Chemical Co., Ltd.] has two sheets of triethyl fluorene-based cellulose film stuck to polyethylene. The alcohol adsorbs a structure of a polarizing film having an iodine, and an acrylic pressure-sensitive adhesive layer is provided on one surface thereof. On the other hand, the quarter-wavelength plate produced in the above (a) is directed away from the retardation axis 45. The direction is cut, and a corona discharge treatment is performed on a single surface under the condition of a cumulative irradiation amount of 1680 J, and the corona discharge treatment surface is attached to the linear polarizing plate* within 30 seconds after the corona discharge treatment. The acrylic pressure sensitive adhesive layer side. At this time, the absorption axis of the linear polarizing plate and the slow axis of the quarter-wavelength plate are arranged at an angle of 45 degrees. In this manner, an elliptically polarizing plate in which a quarter-wave plate made of an acrylic resin was laminated on a linear polarizing plate was obtained. (c) Ellipticity measurement of the elliptically polarizing plate. The ellipticity of the elliptically polarizing plate produced in the above (b) was measured using the phase difference measuring device "K0BRA-21ADH" manufactured by Oji Scientific Instruments Co., Ltd. Here, the ellipticity refers to the ratio of the length of the short axis of the circularly polarized light emitted from the side of the 1/4 wavelength plate to the length of the axis of the length of 27 320734 200928521 when light is incident from the side of the linear polarizing plate of the elliptically polarizing plate. The ellipticity of the elliptically polarizing plate obtained in this example is '〇. 925. This is equivalent to the ellipticity 925 of the elliptically polarizing plate of the quarter-wave plate formed of the norbornene resin shown in Comparative Example 1 to be described later. [Example 2] (Production of another 1/4 wavelength plate) The propylene/ethylene random copolymer ["Sumitomo Noblen W151"] which was the same as the user of Example 1 was formed into a film to obtain a thick 4 〇Am original. The raw material film was stretched toward the horizontal uniaxial axis by a stretcher transverse stretching machine in the same manner as in the first embodiment (a). However, the linear velocity was changed to 5 m/min, the preheating temperature was changed to 136 t:, the elongation temperature was changed to 126 t:, and the final elongation ratio was changed to 4 times. The in-plane retardation value Ro, the thickness direction retardation value, the Nz coefficient, the wavelength dispersion of the phase difference, and the thickness of the obtained stretched film (retardation film) were carried out in the same manner as in the example (&). The results are shown in Table 1. The in-plane retardation rib ❹ of the retardation film is 90 nm, and functions as a quarter-wavelength plate. [Example 3] (Production of 1/2 wavelength plate) The propylene/ethylene random copolymer ["Sumitomo Noblen Ψ 151"] which was the same as the user of Example 1 was formed into a film to obtain a thick 6 〇 #ω The material film 2 extends the original film to the horizontal uniaxial axis by a stretcher transverse stretching machine at a linear velocity of 20 m/min, firstly adjusted to a preheating zone of 126 by the temperature, and then adjusted to a temperature of 116. . The extension area of the crucible is carried out in such a manner that the extension ratio of the maximum and the 's is five times. The in-plane retardation value R〇, the thickness direction retardation value Rth, the Nz coefficient, and the thickness of the obtained stretched film (phase 320734 28 200928521, the retardation film) were measured in the same manner as in the first embodiment (5). The results are shown in Table 1. This retardation film has an in-plane retardation value R 〇 of 28 Onm ′ which functions as a 1/2 wavelength plate. * [Example 4] '(a) Preparation of a 1/4 wavelength plate. High density made of Jingye Polyethylene Co., Ltd. was added to a propylene monomer having a melt flow rate of 8 gdO min and having stereoregularity in the same row. Polypropylene G1900 1% by weight of a polypropylene resin film was formed into a film to obtain a raw material film having a thickness of 40 μm. The raw material film is stretched toward the horizontal uniaxial axis by a stretcher transverse stretcher. The extension was adjusted to a preheating zone of 140 C at a line speed of 5 m/min, first by temperature, and then the temperature was adjusted to 16 Torr. The extended region of the crucible is thereafter carried out in such a manner that the heat-fixing region adjusted to 12 ° C is four times the final stretching ratio. The in-plane retardation value R〇, the thickness direction retardation value Rth, the core coefficient, and the wavelength dispersion of the phase difference of the obtained stretched film (retardation film) are the same as in the method of (a) of the first embodiment. The measurement was carried out. The results are shown in Table 1. This retardation film has an in-plane retardation value R 〇 of 150 nm and functions as a quarter-wavelength plate. (b) Preparation of elliptically polarizing plate The following linear polarizing plate [SR_W062] sold by Sumitomo Chemical Co., Ltd.: has a polarizing film made of polyvinyl alcohol adsorbed and detached by two sheets of three The acetaminocellulose film has a structure in which it is sandwiched, and an acrylic pressure-sensitive adhesive layer is provided on one surface thereof. On the other hand, the 1/4 wavelength plate produced in the above (a) is moved away from the retardation axis 45. The direction is cut. The corona discharge treatment is performed on the condition that the single side is accumulating 29 320734 200928521 and the irradiation amount is 1680 J. The corona discharge treatment surface is attached to the linear polarized light within 30 seconds after the corona discharge treatment. The acrylic pressure-sensitive adhesive layer side of the plate is placed such that the absorption axis of the linear polarizing plate and the slow axis of the quarter-wave plate intersect at an angle of 45 degrees. An elliptically polarizing plate in which a quarter-wave plate made of acrylic resin is laminated on a linear polarizing plate. (c) Ellipticity measurement of an elliptically polarizing plate, and a phase difference measuring device "k〇" manufactured by Oji Scientific Instruments Co., Ltd. Bra_ 21ADH" was measured in the above-mentioned ellipse Ellipticity of the light plate. The ellipticity of the elliptically polarizing plate obtained in this example is 925 925. [Example 5] The same polypropylene film as the user of Example 4 was formed to have a thickness of 40# m. The raw material film was stretched toward the horizontal uniaxial axis in the same manner as in the case of (a) of Example 4, but the linear velocity was changed to 5 ^ / . The knives and the preheating temperature were changed to 1702⁄4. The elongation temperature is changed to 15 °C and the heat setting temperature is changed to 12 〇. (: The final stretching ratio is changed to 3'. The in-plane phase difference and thickness of the stretched film (retardation film) obtained are changed. The directional phase difference values Rth, Nz coefficients, and thicknesses were measured in the same manner as in the first embodiment (a), and the results are shown in Table i. The phase difference in-plane phase difference R 〇 was 97 nm. Working as a quarter-wave plate [Example 6] A polypropylene resin film similar to that of the user of Example 4 was produced to obtain a raw material film having a thickness of 40/zm. The raw material film was stretched. Extender 320734 30 200928521, the extension machine extends to the horizontal single axis. The line speed is 5m/min, preheating, degree N〇°c, extension temperature system 160. 〇, heat-fixing temperature system 12 (rc, final stretching ratio is 4 times. Surface/internal phase difference R〇, thickness direction of the obtained stretched film (retardation film) The phase difference values Rth, Nz coefficients, and thicknesses were measured in the same manner as in (4) of the first embodiment, and the results are shown in Table 1. The in-plane retardation value R 此 of the retardation film was 273 nm. The 1/2 wavelength plate functions as a function. [Example 7] 〇 A film of a propylene monofilament having a melt flow rate of 8 g/10 min and having stereoregularity in the same row was obtained, and the original was obtained. In the same manner as (4) of the fourth embodiment, the film was stretched toward the horizontal uniaxial axis by a stretcher transverse stretcher. However, the line speed was changed to 5 m/min, and the preheating temperature was changed to (10). c, the extension temperature is changed to 14 〇t, and the heat setting temperature is changed to 120. (: 'The final stretching ratio is changed to 4 times. The surface-difference value Rq of the obtained stretched film (retardation film), the thickness direction phase difference ❹Rth Nz coefficient, the wavelength dispersion of the phase difference, and the thickness are The measurement was carried out in the same manner as in the green of the first embodiment (4). The result is shown in the table towel. The phase in-phase phase R is U7 nm, and it is used as a quarter-wave plate to perform the power month & [Embodiment 8] π The film thickness of the film of the polypropylene film which is the same as that of the user of Example 7 was 40, and the film of the original material was stretched by a single axis in the same manner as (4) of Example 4, but the material (4) was changed. In the W-knife clock, the preheating temperature is changed to 17〇〇c, the extension temperature is changed to 320734 31 200928521 C, the thermosetting temperature is changed to 120 C, and the final stretching ratio is changed to 3 times. The obtained stretching film ( The in-plane retardation value R〇, the thickness direction retardation value Rth, the Nz coefficient, and the thickness of the retardation film were measured in the same manner as in the first example (day), and the results are shown in the table. The in-plane phase difference Ro of the retardation film is 91 nm' to function as a quarter-wave plate [Example 9] A raw material film having a thickness of 40/m which was obtained by forming a film of the same polypropylene resin as that of the user of Example 7 was used in the same manner as in Example 4). The tensioner transverse stretcher extends toward the horizontal single axis. However, the line speed was changed to 5 m / min. The preheating temperature was changed to 17 〇. (: The elongation temperature is changed to ι6 〇 C, and the heat setting temperature is changed to 12 (TC, and the final stretching ratio is changed to 4 times. The in-plane phase difference value of the obtained stretched film (retardation film) is this. The directional phase difference values Rth, Nz coefficients, and thicknesses were measured in the same manner as in the example i (a), and the results are shown in Table i. The in-plane phase difference Ro of the phase difference ❹ film was 277 nm. [Comparative Example 1] A retardation film for a quarter-wave plate in which a norbornene resin film is longitudinally uniaxially stretched [sold by Sumitomo Chemical Co., Ltd.) "SES440140Z"], the wavelength dispersion and thickness of the in-plane phase difference Ro, the thickness direction phase difference Rth, the Nz coefficient, and the phase difference are measured in the same manner as in the embodiment, and the results are shown in the table. In addition to the use of the retardation film, an ellipse bias 320734 32 200928521 was produced in the same manner as in the first embodiment (b), and the elliptically polarizing plate was applied to the elliptically polarizing plate in the same manner as in the first embodiment. The rounding rate of the groove. The rounding ratio of the elliptically polarizing plate is 〇925. Example 2] • A retardation film [SES360140Y] sold by Sumitomo Chemical Co., Ltd. The in-plane phase difference value Ro, the thickness direction phase difference value, the Μ coefficient, and the thickness were measured in the same manner as in the first embodiment (a), and the results are shown in Table 1. ❹ [Comparative Example 3] The retardation film of the 1/2 wavelength plate in which the W _ resin film is vertically uniaxially stretched [ZM_3〇〇 sold by 〇pts, and is the same as the method of (a) of the example 1) The in-plane phase difference R, the thickness direction phase difference Rth, the Nz slit, and the thickness are shown in Table 1. [Comparative Example 4] The same propylene/eththene as the user of Example 1. The random copolymer 〇 ["Sumitomo Noblen Wl51"] was formed into a film, and a raw film of 5 〇 〇 owed was obtained to extend the raw material film toward the longitudinal uniaxial axis. The extension was adjusted to the linear velocity minute, first by the temperature to The preheating zone of n5〇c, the extension zone where the rain is adjusted to Bp to 118 °C, the final extension ratio is 1.37 times. The in-plane phase difference value Ro of the obtained stretched film (retardation film), the thickness direction retardation value Rth, the Nz coefficient, the wavelength dispersion of the phase difference, and the thickness ' are the same as those of the first embodiment (a) The results are shown in Table 1. The retardation film in-plane phase difference Ro is 275 nm, and functions as a 1/2 wavelength plate. 33 320734 200928521 _ [Table 1] Material of retardation film * Physical properties of extended phase retardation film ~~~ ^ Ro (nm) Rth (nm) Nz Wavelength dispersion thick ί'' (nm) Example 1 PP Cross 140 77 1.0 1.00 8.0 Example 2 PP 90 90 1.0 1.00 9.0 Example 3 PP Transverse 280 153 1. 0 - 12.7 Example 4 PP+ nucleating agent Transverse 150 J 79 1.0 1.00 --- 9.7 Example 5 PP+ nucleating agent Transverse 97 49 1.0 — 8.0 Example 6 PP+ nucleating agent 273 140 1.0 - 8.5 Example 7 PP Transverse 147 75 1.0 1.00 9.3 Example 8 PP Transverse 91 46 1.0 — 1 ---- 8.1 Example 9 PP Transverse 277 145 1.0 8.2~~~ Comparative Example 1 NOR Vertical 140 67 1.0 1.01 45.5 Comparative Example 2 NOR Cross 139 149 1.6 A 62.0 Comparative Example 3 NOR Longitudinal 298 150 1.0 — 116 Comparative Example 4 PP Vertical 275 138 1.0 1.00 44. Material of eucalyptus retardation film PP: Polypropylene pp+ nucleating agent: polypropylene + nucleating agent N0R : norbornene 〇 in the case of norbornene thin resin' as in Comparative Example 1 and As shown in Fig. 3, a 1/4 wavelength plate and a 1/2 wavelength plate having an Nz coefficient of about 1 by a longitudinal uniaxial extension have been provided on the market. However, the thickness thereof was 45. 5 / z m in the 1/4 wavelength plate (Comparative Example 1) and 116 / / m in the 1/2 wavelength plate (Comparative Example 3). On the other hand, as shown in the comparative example 2, the transverse uniaxial extension of the norbornene resin is also provided in the market, but its & coefficient is 1.6. 'The thickness also becomes 62#m. 320734 34 200928521 However, as shown in Examples 1 to 9, by making the poly-mother tree moon film stretch uniaxially at a high magnification, it is possible to manufacture a y/4 wavelength plate having a core coefficient of about i or 1/2. The wavelength plate has a thickness of 25/m or less and can be formed extremely thin. On the other hand, as shown in Comparative Example 4, when the polypropylene resin film was longitudinally uniaxially stretched, a 1/2 wavelength plate was obtained, but the thickness was not reduced by shrinkage, and it was difficult to achieve the present invention. The so-called extremely thin type below 25ym. The 1/4 wavelength plate fabricated in (a) of Example j or (a) of Example 4, and the Example or Example 6 are laminated at the axial angle described above with reference to FIG. On the 1/2 wavelength plate, a 1/4 wavelength plate in the wide band is available. Further, on the 丨/2 wavelength plate side, the linear polarizing plate shown in (b) of Example 1 or (a) of Example 4 is laminated at the axial angle previously described with reference to Fig. 2 In the present invention, the stretched film of the polypropylene resin is applied to the retardation film, and the thickness of the ellipsoidal film is 25 Å or less. The extremely thin film exhibits the effect of the desired retardation value. Further, by using the polypropylene resin film, even if the lateral extension ' ^ can be extended at a high magnification, it is possible to make a substantially complete round. Advantages. Furthermore, the phase difference of the present invention can be manufactured by lateral extension, so that it has the advantage of widening the effective width while thinning the film thickness. The present invention also contributes to laminating the retardation film. Liquid crystal display device

Tong Jing / k. J,% ♦ KV, W” 丨 战 之 之 相位 : : : : : : : : : 臈庳 臈庳 臈庳 臈庳 臈庳 臈庳 臈庳 臈庳 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 320 a wavy plate in which a 1/4 wavelength plate is laminated to a linear polarizing plate, or an elliptically polarizing plate in which a 1/4 wavelength plate and a 1/2 wavelength plate are combined to be laminated on a linear polarizing plate It does not have good reflection prevention characteristics, and contributes to thinner thickness of the liquid crystal display device. [Simple description of the drawing] Fig. 1 is a cross-sectional view showing the structure of the enamel layer according to the present invention. (A) and a diagram for explaining the relationship of the shaft angle (B) 〇 _ 2 is another embodiment of the elliptically polarizing plate of the present invention, which is a schematic cross-sectional view (A) of the display layer and a shaft for explaining the axis Fig. 3 is a cross-sectional view showing an example in which the elliptically polarizing plate of the present invention is applied to a liquid crystal display. Fig. 4 is a diagram showing the ellipse of the present invention. The polarizing plate is suitable for the interception of another example of the liquid crystal display device Fig. ^ 】 10 15 20 30 50 1/4 1⁄4 wavelength plate 1 / 2 wave plate linear polarizer 35 ellipsoidal liquid crystal cell 12 17 22 40 60 1⁄4 wavelength plate slow phase axis 1/2 wavelength plate The retardation of the linear polarizer of the retardation wheel is light-sensitive. The back layer of the backlight is from the absorption axis of the linear polarizer to the retardation angle of the quarter-wave plate. 320734 36 200928521 Φ From the absorption axis of the linear polarizer to the 1/2 wavelength plate Angle of the slow phase axis Ψ Angle from the absorption axis of the linear polarizer to the slow axis of the 1/4 wavelength plate ❹ 37 320734

Claims (1)

200928521 VII. Patent application scope: 1. A retardation film consisting of a transversely stretched film of polypropylene resin with a thickness of 25#m or less and a phase difference (Ro) in the range of 70 to 400 nm. Further, when the refractive index in the retardation axis direction of the film is nx, the refractive index in the in-plane axis direction is ny, and the refractive index in the thickness direction is nz, the formula: Nz = (nx - nz) The range of the range of 0.9 to 1.1 is defined by the value of the Nz coefficient defined by /(nx-ny). 2. The retardation film of claim 1, wherein the polypropylene resin is composed of a copolymer of propylene and ethylene containing 10% by weight or less of a vinyl unit. 3. The retardation film of claim 1, wherein the polypropylene resin is substantially composed of a propylene individual polymer. 4. The retardation film according to any one of claims 1 to 3, wherein the polypropylene resin contains a nucleating agent. 5. For the phase difference film of Patent No. 1 or 2, it functions as a quarter-wave plate. 6. For the phase difference film of Patent No. 1 or 2, it functions as a 1/2 wavelength plate. 7. An elliptically polarizing plate comprising a phase difference film of claim 1 or 2 laminated on a linear polarizing plate. 8. An elliptically polarizing plate which is formed by laminating a retardation film which functions as a 1/4 wavelength plate of the third aspect of the patent application to a linear polarizing plate. 9. An elliptically polarizing plate which is a retardation film which functions as a 1/4 wavelength plate in the fifth application of the patent application, and a function of 38 320734 200928521 '1/2 wavelength plate of the patent application model 6 The retardation film is laminated, and a linear polarizing plate is laminated on the side of the 1/2 wavelength plate. A liquid crystal display device characterized in that the elliptically polarizing plate of claim 7 is laminated on at least one side of the liquid crystal cell. 11. A liquid crystal display device characterized in that an elliptical polarizing plate of claim 8 or 9 is laminated on at least one side of a liquid crystal cell. ❹ ❹ 39 320734