WO2003052471A1

WO2003052471A1 - Polarizing plate, production method thereof and liquid crystal display

Info

Publication number: WO2003052471A1
Application number: PCT/JP2002/013133
Authority: WO
Inventors: Keiichi Taguchi; Hiromoto Kitakouji; Kentaro Shiratsuchi
Original assignee: Fuji Photo Film Co., Ltd.
Priority date: 2001-12-18
Filing date: 2002-12-16
Publication date: 2003-06-26
Also published as: AU2002356436A1; JP2005513521A; TW200301374A

Abstract

The present invention provides a polarizing plate which comprises an obliquely stretched polymer film obtained by subjecting a polymer film to an oblique stretching method capable of improving the yield in the step of punching out a polarizing plate, has excellent smoothness, can be produced simply and easily at a low cost, a production method of the polarizing plate, and a liquid crystal display using the polarizing plate. A long polarizing plate of the present invention comprises a transparent protective film, a polarizing film and an optical compensating layer, in this order, and the polarizing film has the absorption axis neither in parallel nor perpendicular to the phase lag axis of the transparent support.

Description

DESCRIPTION

POLARIZING PLATE, PRODUCTION METHOD THEREOF and LIQUID

CRYSTAL DISPLAY

Technical Field

The present invention relates to a polarizing plate having a view angle enlarging function. More specifically, the present invention relates to a long polarizing plate comprising a long polarizing film ensuring high yield and excellent polarizing ability and a view angle enlarging element and further comprising a protective film, and also relates to a polarizing plate punched out from the long polarizing plate, production methods for these polarizing plates, and a liquid crystal device using the polarizing plate. Background Art

With the popularization of a liquid crystal display (hereinafter referred to as "LCD"), demands for a polarizing plate are abruptly increasing. The polarizing plate generally comprises a polarizing film having a polarizing ability and a protective film attached to both surfaces or one surface of the polarizing film through an adhesive layer.

The material used for the polarizing film is mainly polyvinyl alcohol (hereinafter referred to as "PVA"). A PVA film is monoaxially stretched and then dyed with iodine or a dichromatic dye or dyed and then stretched and this film is further crosslinked with a boron compound to form a polarizing film.

For the protective film, cellulose triacetate is mainly used because this film is optically transparent and small in the birefringence. The polarizing film is usually produced by monoaxially stretching a continuous film in the running direction (longitudinal direction) and therefore, the absorption axis of the polarizing film is almost in parallel to the longitudinal direction.

In recent years, a liquid crystal display (hereinafter called "LCD") is widely used in place of CRT, because this device is thin, lightweight and small in the electric power consumed. The general-purpose LCD of optical rotation mode, such as TFT-LCD and MIM-LCD, is advantageous in many points as compared with birefringent mode or other modes, but since the display color or display contrast varies depending on the angle when the liquid crystal display is viewed (view angle properties), its display properties cannot reach the level of CRT.

Techniques for improving the view angle properties (namely, enlarging the view angle) have been developed as seen in various patent publications, for example, a phase difference plate (optical compensating sheet) provided between a pair of polarizing plates and a liquid cell (see, JP-A-4-229828 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") and JP-A-4-258923 ) , an optical compensating sheet having a negative birefringence and an inclined optical axis (see, JP-A-6-75115 and EP-A-0576304 ) , an optical compensating sheet obtained by coating a polymer having liquid crystallinity on the surface of an orientation film on a support film (see, JP-A-3-9326 and JP-A-3- 291601), and an optical compensating sheet composed of a polymerizable rod compound having liquid crystallinity and positive birefringent property (see, JP-A-5-215921 ) . Thus, the enlargement of view angle as a practical performance of LCD has been keenly demanded.

Under these circumstances, the present inventors have disclosed an optical compensating sheet where the optical compensating layer has a discotic structure and a negative birefringent property and the disc plane changes ( JP-A-8-50206) , and an optical compensating sheet where a liquid crystalline compound and an oriented polymer are chemically bonded at the interface ( JP-A-9-152509) , which are very excellent in the view angle enlarging ability and the durability. These disclosed optical compensating sheets are easy to produce and this is one of advantages, however, accompanying increase in use of polarizing plate for LCD, a method enabling more inexpensive production is demanded.

In image display devices such as cathode ray tube display (CRT), plasma display (PDP) and liquid crystal display (hereinafter "LCD"), an antireflective film of reducing the reflectance using the principle of optical interference is generally disposed on the outermost surface of the display so as to prevent reduction of contrast due to reflection of external light or prevent entering of an outer image by reflection.

In LCD, use of a polarizing plate is essential in view of the principle of image display and with the recent popularization of LCD, demands for a polarizing plate are increasing. The polarizing plate generally has a structure such that on both surfaces or one surface of a polarizing film having a polarizing ability, a protective film is attached through an adhesive layer. In LCD, a polarizing plate is disposed before and after a liquid crystal cell, therefore, in the polarizing plate at least in the front surface side of a display, an antireflective film consisting of two or three layers different in the refractive index is usually provided on the protective film to impart a reflection preventing ability by making use of the difference in the refractive index between layers.

In conventional LCD, the polarizing plate is disposed by inclining its transmission axis at 45° with respect to the vertical or transverse direction of a picture plane and therefore, the polarizing plate produced in a roll form must be punched in the 45° direction with respect to the longitudinal direction of the roll in the punching step. However, if the polarizing plate is punched in the 45° direction, a portion which cannot be used is generated in the vicinity of edges of the roll and particularly in the case of a large-size polarizing plate, the yield decreases. As a result, the waste disadvantageously increases. Also, the polarizing plate having an optical anisotropic layer after combining has a problem that the waste increases.

In order to solve the above-described problem, several methods have been proposed for inclining the orientation axis of the polymer constituting the film at a desired angle with respect to the longitudinal direction of the film for the polarizing film. JP-A- 2000-9912 describes a technique where while monoaxially stretching a plastic film in the transverse or longitudinal direction, the film is tensile-stretched in the longitudinal or transverse direction different from the above-described stretching direction by changing the stretching speed between right and left sides of the stretching direction so as to incline the orientation axis with respect to the monoaxial stretching direction. However, according to this method, in the case of using, for example, a tenter system, the conveyance speed must be changed between right and left sides and this causes straining, wrinkling or film biasing, as a result, a desired tilt angle (45° in the polarizing plate) can be hardly obtained. For reducing the difference in the speed between right and left sides, the stretching step must be prolonged and the equipment cost greatly increases .

JP-A-3-182701 discloses a method of producing a film having a stretching axis at a specific angle with respect to the film running direction by using a mechanism where a plurality of laterally paired film- holding points each making a constant angle with the running direction are provided at both side edges of a continuous film (lengthy film) and each pair of points can stretch the film to the above-described direction as the film runs. Also in this method, since the film travelling speed differs between right and left sides of the film, straining or wrinkling is generated on the film and for releasing this, the stretching step must be greatly prolonged, which gives rise to a problem that the equipment cost increases.

JP-A-2-113920 discloses a production method of stretching a film in the direction obliquely crossing the machine direction of the film by conveying the film while gripping both edges thereof between chucks aligned in two rows and running on tenter rails disposed such that the chucks run different distances in a predetermined running section. Also in this method, straining or wrinkling is generated at the oblique stretching and this is disadvantageous for the optical film.

As such, it has been not attained to reduce the loss in the punching of a long polarizing plate and at the same time, to ensure the quality of the polarizing plate, such as plane properties. Particularly, in the case of a polarizing plate where the above-described optical compensating layer and the oriented polarizing film are attached, the punching loss is generated not only in the polarizing film but also in the optical compensating layer and the waste increases.

Korean Unexamined Patent Publication P2001-005184 discloses a polarizing plate where the transmission axis is inclined by a rubbing treatment. However, as generally known, the regulation of orientation by rubbing is effective only in the region from the film surface to at most a nano-order portion and a polarizer such as iodine or dichromatic dye cannot be satisfactorily oriented, as a result, the polarizing performance is disadvantageously poor.

Even if an antireflective film is provided, depending on the difference in the refractive index between layers or between layer and substrate, this rather causes a problem of generating uneven color or increasing the wavelength dependency of reflectance. Furthermore, in the case of an antireflective film having only a hard coat layer and a low refractive index layer, the low refractive index layer must be sufficiently lowered in the refractive index (generally to a refractive index of less than 1.38) so as to reduce the reflectance, however, a fluorine compound as an example of the material having a refractive index of 1.40 or less has no cohesive strength and therefore, has a problem in that the scratch resistance is deficient as a film disposed on the outermost surface of a display.

Also as a polarizing plate, the dimensional stability is poor and there is a problem in the aging stability, because the phase lag axis of the protective film and the absorption axis of the polarizing film are in parallel.

Particularly, in the case of roll-to-roll attaching a polarizing plate and an antireflective film to manufacture a polarizing plate roll having an antireflective film and then punching it, not only the polarizing plate but also the antireflective film are wasted .

Disclosure of the Invention

Accordingly, an object of the present invention is to provide a polarizing plate that can be improved in the yield at the step of punching out a polarizing plate and exhibits high performance.

An further object of the present invention is to provide a polarizing plate enlarged in the view angle and capable of being produced at a low cost, particularly, a polarizing plate having an enlarged view angle, which can be improved in the yield at the step of punching out a polarizing plate and exhibit high performance.

Another object of the present invention is to provide a long polarizing plate having an antireflective film ensured with satisfactory antireflection property, which can elevate the yield of polarizing plate and antireflective film in the step of punching out a polarizing plate and can reduce the waste.

Another object of the present invention is to provide a polarizing plate having an antireflective film excellent in the dimensional stability, particularly aging stability, ensured with satisfactory antireflection property, scratch resistance and antifouling property, and free of uneven color.

Another object of the present invention is to provide a production method using an oblique stretching method, where the above-described polarizing plate can be easily produced.

Another object of the present invention is to provide a liquid crystal display having the polarizing plate .

In order to attain these objects, the present inventors have made extensive investigations on a polarizing plate exhibiting excellent performance while having oblique orientation, as a result, the present invention has been accomplished based on this finding. More specifically, the present invention comprises the following constitutions.

(1) A long polarizing plate comprising a transparent protective film, a polarizing film and an optical compensating layer, in this order, wherein the optical compensating layer comprises a transparent support and an optical anisotropic layer, the optical anisotropic layer includes a liquid crystalline molecule, and the polarizing film has the absorption axis neither in parallel nor perpendicular to the phase lag axis of the transparent support.

(2) The long polarizing plate as described in the item (1), wherein the optical anisotropic layer is a layer having a negative birefringent property and comprising a compound having a discotic structural unit, and the disc plane of the discotic structural unit is inclined with respect to the transparent support plane, in which the angle made by the disc plane of the discotic structural unit and the transparent support plane varies in the thickness direction of the optical anisotropic layer .

(3) The long polarizing plate as described in the item (1), wherein the optical compensating layer has an orientation film comprising an orientating polymer between the transparent support and the optical anisotropic layer, and the orientating polymer and the liquid crystalline molecule of the optical anisotropic layer are chemically bonded through the interface of the optical anisotropic layer and the orientation film.

(4) A polarizing plate comprising a transparent protective film, a polarizing film and an optical compensating layer, in this order, wherein the optical compensating layer comprises a transparent support and an optical anisotropic layer, the optical anisotropic layer includes a liquid crystalline molecule, and the angle made by the phase lag axis of the protective film and the absorption axis of the polarizing film is no less than 10° to less than 90°.

(5) The polarizing plate as described in the item (4), wherein the optical anisotropic layer is a layer having a negative birefringent property and comprising a compound having a discotic structural unit, and the disc plane of the discotic structural unit is inclined with respect to the transparent support plane, in which the angle made by the disc plane of the discotic structural unit and the transparent support plane varies in the thickness direction of the optical anisotropic layer.

(6) The polarizing plate as described in the item (4), wherein the optical compensating layer has an orientation film comprising an orientating polymer between the transparent support and the optical anisotropic layer, and the orientating polymer and the liquid crystalline molecule of the optical anisotropic layer are chemically bonded through the interface of the optical anisotropic layer and the orientation film.

(7) The long polarizing plate as described in the item (1), which comprises a low refractive index layer: containing a fluorine-containing resin; and having a refractive index of 1.38 to 1.49.

(8) The long polarizing plate as described in the item (1), which comprises an antiglare or light-scattering layer containing a binder, the binder having a refractive index of 1.57 to 2.00.

(9) The long polarizing plate as described in the item (1), which comprises an antireflective film including a low refractive index layer and an antiglare or light-scattering layer, wherein the low refractive index layer contains a fluorine-containing resin and has a refractive index of 1.38 to 1.49, and the antiglare or light-scattering layer contains a binder having a refractive index of 1.57 to 2.00.

(10) A method for producing the polarizing plate described in any one of the items (1) to (9), comprising: attaching a polarizing film or polarizing plate in a roll form to an optical compensating layer in a roll form with a roll-to-roll to integrate the polarizing film or polarizing plate with the optical compensating layer and form a roll, in which the optical compensating layer comprises a transparent support and an optical anisotropic layer containing a liquid crystalline molecule; and punching out the polarizing plate described in any one of the items (1) to (9) from the integrated roll, wherein the polarizing film in a roll form is produced by a stretching method comprising: holding both edges of a continuously fed polymer film by holding means; and stretching the film, while travelling said holding means to the longitudinal direction of the film and applying tension to the film, wherein, when Ll represents a trajectory of the holding means from a substantial holding start point until a substantial holding release point at one edge of the polymer film, L2 represents a trajectory of the holding means from a substantial holding start point until a substantial holding release point at the other edge of the polymer film, and W represent a distance between the two substantial holding release points, Ll, L2 and W satisfy a relation represented by formula (1) below, and the difference in the conveyance speed in the longitudinal direction between right and left film gripping means is less than 1%: Formula (1)

|L2-L1| > 0.4W

(11) The method for producing a polarizing plate as described in the item (10), wherein the polymer film for the polarizing film is once stretched to 2 -to 10 times while allowing 10% or more of volatile content to be present, and then shrunk by 10% or more.

(12) The method for producing a polarizing plate as described in the item (10), wherein the polymer film is stretched while keeping the supporting property of the polymer film and while allowing a volatile content percentage of 5% or more to be present, and then reduces the volatile content percentage while being shrunk.

(13) The method for producing a polarizing plate as described in any one of the items (10) to (12), wherein the polymer film for the polarizing film is a polyvinyl alcohol film. (14) The method for producing a polarizing plate as described in the item (13), wherein a polarizer is adsorbed to the polyvinyl alcohol film for the polarizing film before or after the stretching.

(15) The method for producing a polarizing plate as described in any one of the items (10) to (14), wherein the polymer film for the polarizing film is stretched by the method described in the item (10) and then shrunk to reduce the volatile content percentage, and then a transparent protective film is attached to at least one surface of the polarizing film, and then the attached films are after-heated.

(16) The method for producing a polarizing plate as described in any one of the items (10) to (15), wherein the polymer film for the polarizing film is stretched by the method described in the item (10) and then shrunk to reduce the volatile content percentage, and then a transparent protective film is attached to at least one surface of the polarizing film, and at the same time as the attachment or thereafter, an optical compensating layer is further attached to at least one polarizing film that the transparent protective film has been attached. (17) The method for producing a polarizing plate as described in any one of the items 10 to 16, wherein the film having a low refractive index layer and an antiglare or light-scattering layer is continuously attached in one surface side of the polarizing film to provide an antireflective film, in which the low refractive index layer contains a fluorine-containing resin and has a refractive index of 1.38 to 1.49, and the antiglare or light-scattering layer contains a binder, the binder having a refractive index of 1.57 to 2.00.

(18) The method for producing a polarizing plate as described in any one of the items (10) to (16), wherein a low refractive index layer and an antiglare or light- scattering film are coated on the protective film to provide an antireflective film, in which the low refractive index layer contains a fluorine-containing resin and has a refractive index of 1.38 to 1.49, and the antiglare or light-scattering layer contains a binder, the binder having a refractive index of 1.57 to 2.00.

(19) A long polarizing plate comprising: a polarizing film having a stretching axis neither in parallel nor perpendicular to the longitudinal direction; and a low refractive index layer containing a fluorine- containing resin and having a refractive index of 1.38 to 1.49.

(20) A long polarizing plate comprising: a polarizing film having a stretching axis neither in parallel nor perpendicular to the longitudinal direction; and an antiglare or light-scattering layer containing a binder, the binder having a refractive index of 1.57 to 2.00.

(21) A long polarizing plate comprising: a polarizing film having a stretching axis neither in parallel nor perpendicular to the longitudinal direction; and an antireflective film including a low refractive index layer and an antiglare or light-scattering layer, wherein the low refractive index layer contains a fluorine-containing resin and has a refractive index of 1.38 to 1.49, and the antiglare or light-scattering layer contains a binder having a refractive index of 1.57 to 2.00.

(22) A liquid crystal display having at least one of a polarizing plate punched out from the polarizing plate described in any one of the items (1) to (3), (7) to (9) and (19) to (21), the polarizing plate described in any one of the items (4) to (6) and a polarizing plate produced by the method described in any one of the items (10) to (19) .

Brief Description of the Drawings

Fig. 1 is a schematic perspective view showing one embodiment of the polarizing plate of the present invention .

Fig. 2 is a schematic plan view showing the state of punching the polarizing plate of the present invention.

Fig. 3 is a schematic plan view showing one example of the method for obliquely stretching a polymer film of the present invention.

Fig. 4 is a schematic plan view showing one example of the method for obliquely stretching a polymer film of the present invention.

Fig. 5 is a schematic plan view showing one example of the method for obliquely stretching a polymer film of the present invention.

Fig. 6 is a schematic plan view showing one example of the method for obliquely stretching a polymer film of the present invention. Fig. 7 is a schematic plan view showing one example of the method for obliquely stretching a polymer film of the present invention.

Fig. 8 is a schematic plan view showing one example of the method for obliquely stretching a polymer film of the present invention.

Fig. 9 is a schematic plan view showing the state of punching a conventional polarizing plate.

Fig. 10 is a view showing a representative structure of the optical anisotropic layer of the present invention .

Fig. 11 is a view showing another representative structure of the optical anisotropic layer of the present invention .

Fig. 12 is a schematic view showing the relationship of main refractive indices n_x and n_y and the main refractive index n_z in the thickness direction of the transparent support (film) .

Fig. 13 is a cross-sectional schematic view showing the layer structure of the antireflective film.

Fig. 14 is a schematic cross-sectional view showing a preferred embodiment of the layer structure of the polarizing plate according to the present invention.

Fig. 15 is a schematic cross-sectional view showing the layer structure of the liquid crystal display of Example 12 .

Description of Symbolic References

(i) direction of introducing film

(ii) direction of conveying film to next step

(a) step of introducing film

(b) step of stretching film

(c) step of delivering stretched film to next step Al position of engaging film with holding means and position of starting stretching film (substantial holding start point: right)

Bl position of engaging film with holding means (left)

Cl position of starting stretching film (substantial holding start point: left)

Cx position of releasing film and final basis position of film stretching (substantial holding release point: left)

Ay final basis position of film stretching (substantial holding release point: right)

|L1-L2| difference in pathway between right and left film holding means

W substantial width at the end of film stretching step

θ angle made by stretching direction and film- travelling direction

1 substrate

2 hard coat layer

3 antiglare or light-scattering layer

4 low refractive index layer

5 particle

11 center line of film in the introduction side

12 center line of film delivered to next step

13 trajectory of film holding means (left)

14 trajectory of film holding means (right)

15 film in the introduction side

16 film delivered to next step

17, 17' left and right points of starting holding (engaging) film

18, 18' left and right points of releasing film from holding means

21 center line of film in the introduction side

22 center line of film delivered to next step

23 trajectory of film holding means (left)

24 trajectory of film holding means (right)

25 film in the introduction side

26 film delivered to next step

27, 27' left and right points of starting holding (engaging) film

28, 28' left and right points of releasing film from holding means

33, 43, 53, 63 trajectory of film holding means (left)

34, 44, 54, 64 trajectory of film holding means (right)

35, 45, 55, 65 film in the introduction side

36, 46, 56, 66 film delivered to next step 70 protective film

71, 71' stretching axis (phase lag axis) of protective film

72 longitudinal direction

74 adhesive layer

76 antireflective film

80 polarizing film

81 stretching axis (absorption axis) of polarizing film

82 longitudinal direction

83 transverse direction 90 polarizing plate

94, 94' polarizing film (with protective film)

97 liquid crystal cell

98 backlight

99 antireflective film 101 transparent support

101a, 101b, 101c plane in parallel to transparent support plane

102 orientation film

103 optical anisotropic phase

103a, 103b, 103c liquid crystalline discotic compound

104 normal line of transparent support

A first embodiment of the polarizing plate of the present invention, is a laminate of a transparent protective film, a polarizing film having a polarizing ability and an optical compensating layer having a function of enlarging the view field, in this order. This polarizing plate is usually obtained by producing and roll-to-roll combining a long polarizing film (which may have a transparent protective film on at least one surface) and a long optical compensating layer and punching it according to uses, or by producing one or two members of a transparent protective film, a polarizing film having a polarizing ability and an optical compensating layer having a function of enlarging the view field, in the lengthy form, punching the long member and combining these. In the present invention, unless other wise indicated, the "polarizing plate" includes both a long polarizing plate and a polarizing plate punched out. The gist of the present invention resides in that specific oblique stretching means is devised in the production of a polarizing film out of those constituent members and this obliquely stretched polarizing film is combined with a transparent protective film and an optical compensating layer having a function of enlarging the view angle to have a specific angle relationship between respective members superposed. By these designs, even when the film is obliquely stretched, wrinkling or straining is not generated on the stretched film and a polarizing film having excellent smoothness can be obtained. Furthermore, a high cutting yield can be attained and at the same time, the polarizing film can be bound to an optical anisotropic layer for enlarging the view angle while maintaining the functions of these members, so that a polarizing plate having high performance and having a function of enlarging the view angle can be obtained with high productivity.

The above-described stretching method of the polarizing film according to the present invention is preferred as a stretching method for a polarizing film applied to the present invention. In this stretching method, oblique orientation is obtained by the stretching of a polymer film and at the same time, the volatile content percentage at the stretching of film, the shrinkage percentage at the shrinking of film, and the elastic modulus of film before stretching are designed, whereby even when the film is obliquely stretched, wrinkling or straining is not generated on the stretched film and a polarizing film having excellent smoothness can be obtained.

The first embodiment of the polarizing plate of the present invention obtained by superposing respective members is characterized in that in a long polarizing plate, the absorption axis of the polarizing film is neither in parallel nor perpendicular to the phase lag axis of the transparent support (hereinafter, this long polarizing plate is sometimes simply referred to as an "obliquely oriented" polarizing plate) . The angle between the absorption axis direction of the polarizing film and the phase lag axis of the transparent support (irrespective of before or after cutting of the polarizing film) is preferably from 10° to less than 90°, more preferably from 20 to 70°, still more preferably from 40 to 50°, particularly preferably from 44 to 46°.

As for the binding relationship between the transparent protective film and the polarizing film in the polarizing plate of the present invention, the angle made by the phase lag axis of the transparent protective film and the absorption axis of the polarizing film is from 10° to less than 90°, preferably from 20 to 70°, more preferably from 40 to 50°, still more preferably from 44 to 46°. A suitable angle is selected in this range.

By superposing respective members to have such an angle relationship, a single polarizing plate can be obtained in a high yield in the step of punching it out from a long polarizing plate. At the same time, with this angle relationship, the polarizing plate can be produced while maintaining the view angle enlarging function. Furthermore, since the angle between members can be freely set in the above-described range, an optimal angle can be freely selected according to the combination of members.

In the punching step of cutting the polarizing plate according to its use, a long polarizing plate may be punched or a transparent protective film, a polarizing film having a polarizing ability and an optical compensating layer having a function of enlarging the view angle may be attached after one or two members out of these three members are punched.

The optical compensating layer for use in the present invention includes two constitutions having the same function. One is an optical compensating layer comprising a transparent support having thereon a layer element for optical compensation which is a layer having a negative birefringent property and composed of a compound having a discotic structural unit and in which the disc plane (hereinafter sometimes simply referred to as "plane") of the discotic structural unit is inclined with respect to the transparent support plane and the angle made by the disc plane of the discotic structural unit and the transparent support plane is changed in the depth direction of the optical anisotropic layer to thereby compensate the attenuation of transmitted light when the view angle is enlarged. Also, an orientation film may be used between the transparent support and the optical anisotropic layer.

Another is a layer element for optical compensation which is a layer element group supported on a transparent support and consists of an orientation film composed of a polymer capable of orientation and an optical anisotropic layer composed of a liquid crystalline compound, where the polymer of the orientation film and the liquid crystalline compound of the optical anisotropic layer are chemically bonded through the interface of these layers to thereby compensate the attenuation of transmitted light when the view angle is enlarged.

The polarizing plate of the present invention can be used for various uses, however, by virtue of its characteristic feature that the orientation axis is inclined with respect to the longitudinal direction, particularly the polarizing film where the tilt angle of the orientation axis is from 40 to 50° with respect to the longitudinal direction, is preferably used as a polarizing plate for LCD, a circularly polarizing plate for antireflection of organic EL displays, or the like.

Furthermore, the polarizing plate of the present invention is suitable also for uses combined with various optical members, for example, phase difference film such as λ/4 plate and λ/2 plate, antiglare' film and hard coat film.

In the first embodiment of the polarizing plate of the present invention, it is not occasionally sufficient that the effect of enlarging the view angle in a downward direction could not be improved by using an optical anisotropic layer. Accordingly, a antireflective layer having a antiglare or light-scattering layer is preferably provided on a viewer side of a polarizer that resides on a viewer side, in view of the improvement of the effect of enlarging the view angle in a downward direction, particularly improvement of a deterioration in contrast, a gradation, a black-and-white reversal and a hue, as described in PCT/JP 02/04270.

A second embodiment of the polarizing plate of the present invention is described below. The second embodiment of the polarizing plate of the present invention is, as described above, characterized in that in a long polarizing plate, the polarizing plate has an antireflective film comprising a low refractive index layer containing a fluorine- containing resin having a refractive index of 1.38 to 1.49 and an antiglare or light-scattering film containing a binder having a refractive index of 1.57 to 2.00 and the absorption axis (stretching axis) of the polarizing film is neither in parallel nor perpendicular to the longitudinal direction (hereinafter, this long polarizing plate is sometimes simply referred to as an "obliquely oriented" polarizing plate). The angle between the longitudinal direction and the absorption axis direction is preferably from 10° to less than 90°, more preferably from 20 to 70°, still more preferably from 40 to 50°, particularly preferably from 44 to 46°. With this angle, a single polarizing plate having an antireflective film can be obtained in a high yield in the step of punching it out from the long polarizing plate and moreover, the obtained polarizing plate is free of uneven color, has excellent antireflective ability and is favored with scratch resistance and antifouling property, which are necessary as a polarizing plate disposed in the front side of LCD. In general, a long polarizing plate (usually in a roll form) is produced and punched according to use, whereby a practical polarizing plate is obtained. Unless otherwise indicated, the "polarizing plate" as used in the present invention includes both a long polarizing plate and a polarizing plate punched out.

On at least one surface of the polarizing film, a stretched protective film is usually attached through an adhesive layer. In the present invention, the angle made by the stretching axes of the polarizing film and the protective film is set to from 10° to less than 90°, whereby a polarizing plate remarkably improved in the dimensional stability and having excellent aging stability can be obtained. More specifically, in Fig. 1 showing a polarizing plate 90 obtained by attaching a protective film 70 having a stretching axis 71 to at least one surface of a polarizing film 80 having a stretching axis 81, if desired, through an adhesive layer

74, the angle θ between the stretching axis 81 of the polarizing film and the stretching axis 71 (namely, dotted line 71') of the protective film is from 10° to less than 90°. Within this range, an excellent dimensional stability can be obtained.

With respect to the angle between the stretching axis (absorption axis) of the polarizing plate and the stretching axis (phase lag axis) of the protective film, the angle made by the absorption axis and the phase lag axis can be estimated by peeling off the protective film and the polarizing film of the polarizing plate and measuring the absorption axis of the polarizing plate and the phase lag axis of the protective film.

The stretching axis of the polarizing film is defined as the axis direction of giving a maximum transmission density when the polarizing plate is superposed on a polarizing plate having a known absorption axis in the cross-Nicol state. The stretching axis of the protective film is defined as the axis direction of giving a maximum refractive index when the refractive index in plane of the protective film is measured. The angle between the stretching axis of the polarizing film and the stretching axis of the protective film means an angle made by those axis directions and is preferably from 10° to less than 90°. The transmission density of the polarizing film can be measured by a transmission densitometer (for example, X Rite. 310TR having mounted thereon a status M filter) and the refractive index of the protective film can be measured by an ellipsometer (for example, AEP-10, manufactured by Shimadzu Corporation) .

Furthermore, it is preferred that the stretching axis 71 of the protective film 70 runs in parallel to the longitudinal direction 82 or transverse direction 83 of the polarizing plate and the stretching axis 81 of the polarizing film 80 makes an angle of 45° with respect to the longitudinal direction 82 or transverse direction 83 of the polarizing plate.

The preparation of the stretched protective film for use in the present invention includes not only the case of stretching the film by providing a stretching step but also the case where an independent stretching step is not provided and the film is stretched by the tension additionally imposed in the longitudinal direction in the after-heating step after the drying of film for the protective film.

The polarizing plate can be easily obtained by designing the polarizing film and the protective film each having a stretching axis to give the above-described angle of stretching axes and combining these films. However, it is preferred to use a long polarizing plate where, as shown in Fig. 2, a protective film having a stretching axis 71 in parallel to the longitudinal direction is attached to at least one surface of a polarizing film having a stretching axis 81 neither in parallel nor perpendicular to the longitudinal direction 82 (namely, obliquely oriented polarizing film) . By using this, when a polarizing plate is punched out as shown in Fig. 2, the yield in the step of punching out a polarizing plate can be improved.

The obliquely oriented polarizing film as shown in Fig. 2 can be produced by a stretching method where both edges of a continuously fed polymer film are held by holding means and the film is stretched while running said holding means to the longitudinal direction of the film and applying a tension and where the trajectory Ll of the holding means from the substantial holding start point until the substantial holding release point at one edge of the polymer film, the trajectory L2 of the holding means from the substantial holding start point until the substantial holding release point at another edge of the polymer film, and the distance W between two substantial holding release points satisfy formula (1) above and the difference in the conveyance speed in the longitudinal direction between left and right film gripping means is less than 1% (hereinafter, this method is especially called an oblique stretching method) . On at least one surface of the obliquely stretched polarizing film obtained as such, a protective film having a stretching axis in the longitudinal direction is continuously attached, whereby a long polarizing plate can be more efficiently produced. The antireflective film can be formed by attaching a film comprising a substrate having sequentially coated thereon an antiglare or light-scattering film and a low refractive index layer, on the polarizing film. The protective film attached as above on the polarizing film may be also served as the substrate and in this case, an antiglare or light-scattering film and a low refractive index layer are previously coated on the protective film and then, the protective film and the polarizing film are combined to produce a polarizing plate. Constitution of Polarizing Plate>

For attaching a protective film to the polarizing film thus produced by oblique stretching, for example, a method of attaching the protective film to the polarizing film using an adhesive while keeping the state of holding both edges in the above-described drying step of the polarizing film and then cutting both edges, or a method of removing the polarizing film from the both edges- holding part after drying, cutting both edges of the film and attaching a protective film thereto may be used.

The polarizing plate of the present invention has the above-described antireflective film and the polarizing film, the protective film and the antireflective film preferably stacked to constitute a structure of protective film/polarizing film/protective film/antireflective film (Structure (1), Fig. 14(a)) or a structure of protective film/polarizing film/protective film/antireflective film substrate/antiglare antireflective film (Structure (2), Fig. 14(b)).

The polarizing plate having Structure (1) is produced by combining a polarizing film obtained as above using the oblique stretching method and having attached to one surface thereof a protective film, with an antireflective film formed by coating an antiglare or light-scattering film, a low refractive index layer and if desired, other layers on a protective film as the substrate, or by first attaching a protective film to both surfaces of the polarizing film and forming an antireflective film by coating the layers on the protective film in one side.

The polarizing plate having Structure (2) can be produced by combining a polarizing plate having attached to both surfaces thereof a protective film, with an antireflective film formed by the coating on an anti- reflective film substrate.

From the standpoint of elevating the contrast of a liquid crystal display, the polarizing plate of the present invention preferably has a high transmittance and a high polarization degree. The transmittance is preferably 30% or more, more preferably 40% or more, at 550 nm. The polarization degree is preferably 95.0% or more, more preferably 99% or more, still more preferably 99.9% or more, at 550 nm.

The polarizing plate of the present invention is preferably used for a liquid crystal display. The liquid crystal display generally comprises a liquid crystal display element and a polarizing plate. The liquid crystal display element comprises a liquid crystal layer, a substrate for holding the liquid crystal layer, and an electrode layer for applying a voltage to the liquid crystal. The substrate and the electrode layer both are produced using a transparent material for the purpose of display. As the transparent substrate, a glass thin plate or a resin film is used. In the case of a liquid crystal display required to have some flexuosity, a resin film must be used. In addition to high transparency, the liquid crystal substrate is required to have low birefringence and heat resistance. A phase difference plate is sometimes provided in the liquid crystal display, The phase difference plate is a birefringent film for removing coloring on the liquid crystal picture element and realizing black-and-white display. The phase difference plate is also produced by using a resin film. The phase difference plate is required to have a high birefringence. The polarizing plate comprises a protective film and a polarizing film. The polarizing film is a resin film using iodine or a dichromatic dye as a polarization element. The protective film is provided on one surface or both surfaces of the polarizing film for the purpose of protecting the polarizing film. In the case of providing the protective film only on one surface of the polarizing film, the above-described liquid crystal substrate generally serves as the protective film on the other surface. The protective film of a polarizing plate is required to have transparency and low birefringence (low retardation value) and the cellulose acetate film of the present invention is particularly advantageously used therefor.

The polarizing film of a polarizing plate includes iodine-type polarizing film, a dye-type polarizing film using a dichromatic dye, and a polyene-type polarizing film. Any of these polarizing films is generally produced using a polyvinyl alcohol-type film. The protective film of a polarizing plate preferably has a thickness of 25 to 350 μm, more preferably from 50 to 200 μm. In the protective film, an ultraviolet absorbent, a slipping agent, a deterioration inhibitor and a plasticizer may be added. On the protective film of a polarizing plate, a surface-treating film may be provided in addition to the antireflective film. The function of the surface-treating film includes hard coat and anticlouding treatment. The polarizing plate and the protective film thereof are described in JP-A-4-219703, JP-A-5-212828 and JP-A-6-51117.

The constituent members of the polarizing plate of the present invention and the production method of the polarizing plate are sequentially described. First, the polarizing film of the present invention and a preferred stretching method therefor (hereinafter sometimes referred to as a stretching method of the present invention) are described in detail. I. Polarizing Film <Stretching Method>

Figs. 3 and 4 each is a schematic plan view showing an example of the method for obliquely stretching a polymer film for the polarizing film (hereinafter, "for the polarizing film" of the "polymer film for the polarizing film" is omitted if there is no fear of confounding or misunderstanding with other polymer layer) ,

The stretching method of the present invention comprises (a) a step of introducing an original film in the direction of the arrow (i), (b) a step of stretching the film in the cross direction, and (c) a step of conveying the stretched film to the next step in the direction of the arrow (ii) . The "stretching step" referred to hereinafter contains these steps (a) to (c) and indicates the entire step for performing the stretching method of the present invention.

The film is continuously introduced from the direction (i) and first held at the point Bl by the holding means in the left side seen from upstream. At this point, the other edge of the film is not held and tension is not generated in the cross direction. In other words, the point Bl is not a point where the holding is substantially started (hereinafter referred to as a "substantial holding start point").

In the present invention, the substantial holding start point is defined as the point where both edges of the film are first held. The substantial holding start point includes two points, that is, a holding start point Al in the more downstream side and a point Cl where a straight line drawn almost perpendicularly to the center line 11 (Fig. 3) or 21 (Fig. 4) of the film in the introduction side from Al meets the trajectory 13 (Fig. 3) or 23 (Fig. 4) of the holding means in the opposite side .

Starting from these points, when the film is conveyed by the holding means at both edges at a substantially equal speed, Al moves to A2, A3 ... An every each unit time and Cl similarly moves to C2, C3 ... Cn. That is, the straight line connecting points An and Cn where the holding means as the bases pass at the same time is the stretching direction at that time.

In the method of the present invention, as shown in Figs. 3 and 4, An is gradually delayed from Cn and therefore, the stretching direction is gradually inclined from the direction perpendicular to the conveyance direction. In the present invention, the point of substantially releasing the holding (hereinafter referred to as a "substantial holding release point") is defined by two points, that is, a point Cx where the film leaves from the holding means in the more upstream side, and a point Ay where a straight line drawn almost perpendicularly to the center line 12 (Fig. 3) or 22 (Fig. 4) of the film delivered to the next step from Cx meets the trajectory 14 (Fig. 3) or 24 (Fig. 4) of the holding means in the opposite side.

The angle of the final stretching direction of the film is determined by the ratio of the pathway difference between the right and left holding means at the substantial end point of the stretching step (substantial holding release point), Ay-Ax (that is, |Ll-L2|), to the distance W between substantial holding release points (distance between Cx and Ay) . Accordingly, the tilt angle θ of the stretching direction with respect to the conveyance direction to the next step is an angle satisfying the relationship: tanθ = W/ (Ay-Ax), that is, tanθ = W/ |L1-L2 |

The film edge in the upper side of Figs. 3 and 4 is held until 18 (Fig. 3) or 28 (Fig. 4) even after the point Ay, however, since the other edge is not held, the stretching in the cross direction is not newly generated. Therefore, 18 and 28 are not a substantial holding release point.

In the present invention, as in the above, the substantial holding start points present at both edges of the film are not a point where the film is merely engaged with each of right and left holding means. To more strictly describe the two substantial holding start points of the present invention defined above, these are defined as points where a straight line connecting the left or right holing point and another holding point almost orthogonally meets the center line of the film introduced into the step of holding the film, and which are two holding points positioned most upstream.

Similarly, in the present invention, the two substantial holding release points are defined as points where a straight line connecting the left or right holding point and another holding point almost orthogonally meets the center line of the film delivered to the next step, and which are two holding points positioned most downstream.

The term "almost orthogonally" as used herein means that the center line of the film makes an angle of

90±0.5° with the straight line connecting the left and right substantial holding start points or substantial holding release points.

In the case of giving a difference between the left and right pathways by using a tenter-system stretching machine, due to the mechanical limitation such as rail length, there arises a large dislocation between the point of being engaged with the holding means and the substantial holding start point or between the point of being disengaged from the holding means and the substantial holding release point, however, as long as the pathway from the substantial holding start point to the substantial holding release point defined above satisfies the relationship in formula (1), the object of the present invention can be achieved.

The tilt angle of the orientation axis of the stretched film can be controlled and adjusted by the ratio of the outlet width W in the step (c) to the substantial difference in the pathway between the right and left holding means |L1-L2|. For the polarizing plate and phase difference film, a film oriented at 45° with respect to the longitudinal direction is often required. In this case, for obtaining an orientation angle close to 45°, the following formula (2) is preferably satisfied: Formula (2): 0.9W< | L1-L2 | <1.1W.

More preferably, the following (3) is satisfied: Formula (3): 0.97W< | L1-L2 | <1.03W.

As long as the formula (1) is satisfied, the specific structure for the stretching step can be freely designed as shown in Figs. 3 to 8 by taking account of the equipment cost and productivity.

The angle made by the direction (i) of introducing the film into the stretching step and the direction (ii) of conveying the film to the next step may have an arbitrary numerical value, however, from the standpoint of minimizing the total installation area for the equipment including the steps before and after the stretching, this angle is preferably smaller and is preferably 3° or less, more preferably 0.5° or less. This value can be achieved, for example, by the structure shown in Figs. 3 and 6.

In such a method where the film travelling direction is substantially not changed, the orientation angle of 45° with respect to the longitudinal direction, which is preferred as a polarizing plate or phase difference film, is difficult to obtain only by the enlargement of the width of the holding means. As in Fig,

3, by providing a step of shrinking the film after the film is once stretched, |L1-L2| can be made large.

The stretching ratio is preferably from 1.1 to 10.0 times, more preferably from 2 to 10 times. The shrinkage percentage after that is preferably 10% or more. Furthermore, it is also preferred to repeat stretching- shrinking a plurality of times as shown in Fig. 6, because | L1-L2 | can be made large.

From the standpoint of minimizing the equipment cost for the stretching step, the number of bends in the trajectory of the holding means and the angle of bend are preferably smaller. In this viewpoint, as shown in Figs.

4, 5 and 7, the film travelling direction is preferably bent while keeping the state of holding both edges of the film so that the angle made by the film travelling direction at the outlet of the step of holding both edges of the film and the substantial stretching direction of the film can be inclined at 20 to 70°.

In the present invention, the device for stretching the film by applying a tension while holding both edges is preferably a so-called tenter device as shown in Figs. 3 to 7. Other than the conventional two-dimensional tenter, a stretching step where, as shown in Fig. 8, a difference is spirally given between the pathways of the gripping means at both edges may also be used.

In many cases, the tenter-type stretching machine has a structure where a clip-fixed chain runs along the rail. However, when a vertically non-uniform stretching method as in the present invention is employed, the end terminal of one rail dislocates, as shown in Figs. 3 and 4, from the end terminal of another rail at the inlet and outlet of the step and engaging or disengaging does not occur simultaneously between left and right edges. In this case, the substantial pathway lengths Ll and L2 are not a simple engaging-to-disengaging distance but, as already described above, a length of pathway where the holding means hold both edges of the film.

If the film travelling speed is different between left and right edges at the outlet of the stretching step, wrinkling or biasing occurs. Therefore, right and left film gripping means are demanded to convey the film substantially at the same speed. The difference in the speed is preferably 1% or less, more preferably less than 0.5%, most preferably less than 0.05%. The speed as used herein means the length of trajectory which each of left and right holding means proceeds per minute. In a general tenter stretching machine or the like, according to the cycle of sprocket wheel driving the chain, the frequency of driving motor and the like, unevenness in the order of seconds or less is generated in the speed and unevenness of a few % is often generated, however, these do not come under the difference in the speed referred to in the present invention. <Shrinking>

The shrinking of the stretched polymer film may be performed in either during or after stretching. Shrinking may suffice if it eliminates the wrinkling of polymer film generated at the orientation in the oblique direction. For shrinking the film, a method of heating the film and thereby removing the volatile content may be used, however, any means may be used if it can shrink the film. The film is preferably shrunk to 1/sinθ or more times, where θ is an orientation angle with respect to the longitudinal direction. The shrinkage percentage is preferably 10% or more. <Volatile Content Percentage>

As the right and left pathways come to differ, wrinkling or biasing of film is generated. In order to solve these problems, the present invention is characterized in that the polymer film is stretched while keeping the supporting property and allowing the presence of a state having a volatile content percentage of 5% or more, and then shrunk to reduce the volatile content percentage. The term "keeping the supporting property of polymer film" as used herein means that the film is held at both sides without impairing the film property. The volatile content percentage as used in the present invention means a volume of volatile components contained per the unit volume of film and is a value obtained by dividing the volatile component volume by the film volume.

Furthermore, "stretched while allowing the presence of a state having a volatile content percentage of 5% or more" does not necessarily mean that the volatile content percentage of 5% or more is maintained throughout the process in the stretching step but means that as long as the stretching at a volatile content percentage of 5% or more exerts the effect of the present invention, the volatile content may be 5% or less in a part of the step.

Examples of the method for incorporating the volatile content include a method of casting the film and incorporating a solvent or water, a method of dipping, coating or spraying the film in or with a solvent or water before stretching, and a method of coating a solvent or water during stretching. The hydrophilic polymer film such as polyvinyl alcohol contains water in a high-temperature high-humidity atmosphere and therefore, by stretching the film after humidity conditioning in a high-humidity atmosphere or stretching the film in a high-humidity condition, the volatile content can be incorporated. Other than these methods, any means may be used if the volatile content of the polymer film can be made 5% or more.

The preferred volatile content percentage varies depending on the kind of the polymer film. The maximum of the volatile content percentage may be any as long as the polymer film can keep the supporting property. The volatile content percentage is preferably from 10 to 100% for polyvinyl alcohol. The volatile content percentage is preferably from 10 to 200% for cellulose acylate. <Elastic Modulus>

As for the physical properties of the polymer film before stretching, if the elastic modulus is too low, the shrinkage percentage during or after stretching decreases and the wrinkling difficultly disappears, whereas if it is excessively high, a great tension is applied at the stretching, as a result, the portion of holding both edges of the film must be increased in the strength and a load on the machine increases. In the present invention, the elastic modulus of the polymer film before stretching is preferably, in terms of Young's modulus, from 0.01 to 500 MPa, more preferably from 0.1 to 500 MPa. <Distance from Generation of Wrinkling to Disappearance>

The wrinkling of polymer film, generated at the orientation in the oblique direction, causes no problem if it disappears until the substantial holding release point referred to in the present invention. However, if a long time is spent from the generation of wrinkling to the disappearance, dispersion may be generated in the stretching direction. Therefore, the wrinkling preferably disappears in a travelling distance as short as possible from the point where the wrinkling is generated. For this purpose, for example, a method of increasing the volatilization speed of the volatile content may be used. <Foreign Matters>

In the present invention, if foreign matters are adhering to the polymer film before stretching, the surface becomes coarse. Therefore, the foreign matters are preferably removed. If foreign matters are present, particularly at the time of manufacturing a polarizing plate, these cause color/optical unevenness. It is also important that foreign matters do not adhere to the polymer film until a protective film is combined. Therefore, the polarizing plate is preferably manufactured in an environment where the floating dusts are reduced as much as possible. The amount of foreign matters as used in the present is a value obtained by dividing the weight of foreign matters adhering to the film surface by the surface area and is expressed by the gram number per square meter. The amount of foreign matters is preferably 1 g/m² or less, more preferably 0.5 g/m² or less. The smaller amount is more preferred.

The method for removing foreign matters is not particularly limited and any method may be used as long as it can remove the foreign matters without adversely affecting the polymer film before stretching. Examples thereof include a method of jetting a water flow to scrape off the foreign matters, a method of scraping off the foreign matters by a gas jet, and a method of scraping off the foreign matters using a blade of cloth, rubber or the like. <Drying>

As long as the generated wrinkling disappears, any drying conditions may be used. However, the drying conditions are preferably adjusted such that the drying point comes in a traveling distance as short as possible after a desired orientation angle is obtained. The drying point means a site where the surface temperature of film becomes equal to the atmosphere temperature in the environment. From this reason, the drying speed is also preferably as high as possible. <Drying Temperature>

As long as the generated wrinkling disappears, any drying conditions may be used, however, the conditions vary depending on the film stretched. In the case of preparing a polarizing plate using a polyvinyl alcohol film according to the present invention, the drying temperature is preferably from 20 to 100°C, more preferably from 40 to 90°C.

The volatile content of the final dried polymer film after the completion of step is preferably 3% or less, more preferably 2% or less, still more preferably 1.5% or less .

As such, in a preferred embodiment of the present invention, the stretching method comprises

(i) stretching the film to 1.1 to 20.0 times at least in the cross direction,

(ii) giving a difference of 1% or less in the film travelling speed between both edges in the machine direction of the holding device,

(iii) bending the film travelling direction while holding both edges of the film, such that the angle between the film travelling direction at the outlet in the step of holding both edges of the film and the substantial stretching direction of the film becomes 20 to 70°, (iv) stretching the film while keeping the supporting property of the polymer film and allowing the presence of a state having a volatile content percentage of 5% or more, and then shrinking the film to reduce the volatile content.

Furthermore, preferred various conditions are described below. When the polymer film is polyvinyl alcohol film and a hardening agent is used, the swelling percentage with water is preferably different between before and after the stretching so as not to relieve but to keep the state of being stretched in the oblique direction. More specifically, it is preferred that the swelling percentage before stretching is high and the swelling percentage after stretching and drying becomes low. More preferably, the swelling percentage with water before stretching is 3% or more and the swelling percentage after drying is 3% or less. <Swelling Percentage>

In the present invention, when the polymer film is polyvinyl alcohol and a hardening agent is used, the swelling percentage with water is preferably different between before and after the stretching so as not to relieve but to keep the state of being stretched in the oblique direction. More specifically, it is preferred that the swelling percentage before stretching is high and the swelling percentage after stretching and drying becomes low. More preferably, the swelling percentage with water before stretching is 3% or more and the swelling percentage after drying is 3% or less. Prescription of Bending Part>

The rail of regulating the trajectory of the holding means in the present invention is often demanded to have a large bending ratio. For the purpose of avoiding interference of film gripping means with each other due to abrupt bending or avoiding local concentration of stress, the trajectory of the gripping means preferably draws a circular arc at the bending part, <Stretching Speed>

In the present invention, the speed at which the film is stretched is preferably higher and when expressed by the stretching magnification per unit time, this is 1.1 times/min or more, preferably 2 times/min or more. The travelling speed in the longitudinal direction is 0.1 m/min or more, preferably 1 m/min or more. A higher travelling speed is preferred in view of productivity. In either case, the upper limit varies depending on the film stretched and the stretching machine. <Tension in Longitudinal Direction>

In the present invention, at the time of holding both edges of the film by holding means, the film is preferably tensioned to facilitate the holding. Specific examples of the method therefor include a method of applying a tension in the longitudinal direction to make the film tense. The tension varies depending on the state of film before stretching but is preferably applied to such a degree of not loosening the film. <Temperature at Stretching>

In the present invention, the ambient temperature at the time of stretching the film may be sufficient if it is at least higher than the solidification point of volatile contents contained in the film. In the case where the film is polyvinyl alcohol, the ambient temperature is preferably 25°C or more. In the case of stretching polyvinyl alcohol dipped in iodine/boric acid for the manufacture of a polarizing film, the ambient temperature is preferably from 25 to 90°C. <Humidity at Stretching>

In the case of stretching a film having water as the volatile content, such as polyvinyl alcohol or cellulose acylate, the film may be stretched in a humidity conditioning atmosphere. In the case of polyvinyl alcohol, the humidity is preferably 50% or more, more preferably 80% or more, still more preferably 90% or more . <Polymer Film for Polarizing Film>

In the present invention, the polymer film to be stretched is not particularly limited and a film comprising a polymer having appropriate thermoplasticity may be used. Examples of the polymer include PVA, polycarbonate, cellulose acylate and polysulfone.

The thickness of the film before stretching is not particularly limited, however, in view of stability of film holding and uniformity of stretching, the thickness is preferably from 1 μm to 1 mm, more preferably from 20 to 200 μm.

The polymer for the polarizing film is preferably PVA. PVA is usually obtained by saponifying polyvinyl acetate but may contain a component copolymerizable with vinyl acetate, such as unsaturated carboxylic acid, unsaturated sulfonic acid, olefins and vinyl ethers. Also, a modified PVA containing an acetoacetyl group, a sulfonic acid group, a carboxyl group, an oxyalkylene group or the like may be used.

The saponification degree of PVA is not particularly limited but in view of solubility and the like, is preferably from 80 to 100 mol%, more preferably from 90 to 100 mol%. Also, the polymerization degree of PVA is not particularly limited but is preferably from 1,000 to 10,000, more preferably from 1,500 to 5,000. <Dyeing Formulation/Method>

The polarizing film is obtained by dyeing PVA and the dyeing step is performed by gas-phase or liquid-phase adsorption. As an example of the liquid-phase dyeing, when iodine is used, the dyeing is performed by dipping the PVA film in an aqueous iodine-potassium iodide solution. The iodine is preferably from 0.1 to 20 g/liter, the potassium iodide is preferably from 1 to 200 g/liter and the weight ratio of iodine and potassium iodide is preferably from 1 to 200. The dyeing time is preferably from 10 to 5,000 seconds and the liquid temperature is preferably from 5 to 60°C. The dyeing method is not limited only to dipping but any means can be used, such as coating or spraying of an iodine or dye solution. The dyeing step may be provided either before or after the stretching step of the present invention, however, the dyeing is preferably performed in liquid phase before the stretching step, because the film is appropriately swelled and the stretching thereof is facilitated .

In the process of producing a polarizing film by stretching PVA, an additive capable of crosslinking PVA is preferably used. Particularly, when the oblique stretching method of the present invention is used, if PVA is not sufficiently hardened at the outlet of the stretching step, the orientation direction of PVA may be shifted due to tension in the step. Therefore, a crosslinking agent is preferably incorporated into PVA by dipping PVA in a crosslinking agent solution or by coating the solution, in the step before stretching or in the stretching step. The means to impart the crosslinking agent to the PVA film is not particularly limited and any method such as dipping, coating or spraying of the film in or with the solution may be used, however, a dipping method and a coating method are preferred. As the coating means, any commonly known means such as roll coater, die coater, bar coater, slide coater and curtain coater may be used. Also, a method of bringing a cloth, cotton, porous material or the like impregnated with the solution into contact with the film is preferred. As the crosslinking agent, those described U.S. Re232897 can be used, however, boric acid and borax are preferably used in practice. In addition, a metal salt such as zinc, cobalt, zirconium, iron, nickel and manganese may also be used in combination.

After the hardening agent is added, a rinsing/water washing step may be provided.

The hardening agent may be imparted before or after the film is engaged in the stretching machine. This may be performed in any step until the end of the step (b) in examples shown in Figs. 3 and 4, where the stretching in the cross direction is substantially finished. <Polarizer>

Other than iodine, it is also preferred to dye the film with a dichromatic dye. Specific examples of the dichromatic dye include dye-type compounds such as azo- base dye, stilbene-base dye, pyrazolone-base dye, triphenyl methane-base dye, quinoline-base dye, oxazine- base dye, thiadine-base dye and anthraquinone-base dye. A water-soluble compound is preferred but the present invention is not limited thereto. Also, a hydrophilic substituent such as sulfonic acid group, amino group and hydroxyl group is preferably introduced into these dichromatic molecules. Specific examples of the dichromatic molecule include C.I. Direct Yellow 12, C.I. Direct Orange 39, C.I. Direct Orange 72, C.I. Direct Red 39, C.I. Direct Red 79, C.I. Direct Red 81, C.I. Direct Red 83, C.I. Direct Red 89, C.I. Direct Violet 48, C.I. Direct Blue 67, C.I. Direct Blue 90, C.I. Direct Green 59, C.I. Acid Red 37 and dyes described in JP-A-62-70802 , JP- A-l-161202, JP-A-1-172906, JP-A-1-172907 , JP-A-1-183602 , JP-A-1-248105, JP-A-1-265205 and JP-A-7-261024. These dichromatic molecules are used as a free acid, an alkali metal salt, an ammonium salt or a salt of amines. By blending two or more of these dichromatic molecules, a polarizer having various colors can be produced. A polarizing device or polarizing plate where a compound (dye) of providing black color when polarization axes are orthogonally crossed is blended or where various dichromatic molecules are blended to provide black color is preferred because both the single plate transmittance and the polarization degree are excellent.

The stretching method of the present invention is also preferably used in the production of a so-called polyvinylene-base polarizing film where PVA or polyvinyl chloride is dehydrated or dechlorinated to form a polyene structure and the polarization is obtained by the conjugate double bond. II. Transparent Protective Film

The polarizing plate of the present invention is usually used by attaching a transparent protective film to both surfaces or one surface of the polarizing film. The kind of the protective film is not particularly limited and, for example, cellulose esters such as cellulose acetate, cellulose acetate butyrate and cellulose propionate, polycarbonate, polyolefin, polystyrene and polyester can be used.

The protective film is usually fed in a roll form and preferably attached continuously to a long polarizing plate so that the longitudinal directions can agree. Here, the orientation axis (phase lag axis) of the protective film may run in any direction but in view of simplicity and easiness of operation, the orientation axis of the protective film is preferably in parallel to the longitudinal direction.

The angle between the phase lag axis (orientation axis) of the protective film and the absorption axis (stretching axis) of the polarizing film is also not particularly limited and may be appropriately set according to the use end of the polarizing plate. The absorption axis of the long polarizing plate of the present invention is not in parallel to the longitudinal direction and therefore, when the protective film having an orientation axis in parallel to the longitudinal direction is continuously attached to the length polarizing plate of the present invention, a polarizing plate where the absorption axis of the polarizing film and the orientation axis of the protective film are not in parallel is obtained. The polarizing plate where the polarizing film and the protective film are combined such that the absorption axis of the polarizing film and the orientation axis of the protective film run not in parallel is excellent in the dimensional stability. This performance is advantageously exerted particularly when the polarizing plate is used for a liquid crystal display. The tilt angle between the phase lag axis of the protective film and the absorption axis of the polarizing film is preferably from 10 to 90°. With this tilt angle, a high dimensional stability effect is exerted.

In general, the retardation of the protective film is preferably low. However, when the absorption axis of the polarizing film and the orientation axis of the protective film are not in parallel, particularly, if the retardation value of the protective film is higher than a fixed value, the linear polarization disadvantageously changes into elliptic polarization because the polarizing axis is obliquely shifted from the orientation axis (phase lag axis) of the protective film. Therefore, the retardation of the protective film, for example, at 632.8 nm is preferably 10 nm or less, more preferably 5 nm or less. In view of such a low retardation, the polymer used as the protective film is preferably cellulose triacetate. Also, polyolefins such as ZEONEX, ZEONOR (both produced by Nippon Zeon Co., Ltd.) and ARTON (produced by JSR) are preferably used. Other examples include non-birefringent optical resin materials described in JP-A-8-110402 and JP-A-11-293116.

On the protective film surface of the polarizing plate of the present invention, any functional layer can be provided such as an optical anisotropic layer for compensating the view angle of LCD, an antiglare or antireflection layer for improving visibility of the display, and a layer (e.g., polymer dispersion liquid crystal layer, cholesteric liquid crystal layer) having a function of separating PS wave due to anisotropic scattering or anisotropic optical interference for improving the brightness of LCD described in JP-A-4- 229828, JP-A-6-75115 and JP-A-8-50206, a hard coat layer for elevating scratch resistance of the polarizing plate, a gas barrier layer for preventing diffusion of water content or oxygen, an easily adhesive layer for elevating the adhesive strength to polarizing film, adhesive or pressure-sensitive adhesive, and a layer for imparting slipperiness .

The functional layer may be provided in the polarizing film side or on the surface opposite the polarizing film. The side where the functional layer is provided is appropriately selected according to the purpose .

On one surface or both surfaces of the polarizing film of the present invention, various functional films can be directly attached as a protective film. Examples of the functional film include a phase difference film such as λ/4 plate and λ/2 plate, a light diffusion film, a plastic cell having an electroconductive layer provided on the surface opposite the polarizing plate, a brightness improving film having an anisotropic scattering or anisotropic optical interference function, a reflective plate, and a reflective plate having a transflective function.

As the protective film of the polarizing plate, one sheet of the preferred protective films described above or a plurality of sheets may be stacked. The • same protective film may be attached to both surfaces of the polarizing film or protective films attached to both surfaces may have different functions and physical properties from each other. It is also possible to attach the above-described protective film only to one surface and not attach the protective film to the opposite surface but directly provide thereon a pressure- sensitive adhesive layer for directly attaching thereto a liquid crystal cell. In this case, a releasable separator film is preferably provided in the outer side of the pressure-sensitive adhesive. <Adhesive>

The adhesive for combining the polarizing film and the protective film is not particularly limited and examples thereof include PVA-base resin (including modified PVA such as acetoacetyl group, sulfonic acid group, carboxylic group and oxyalkylene group) and an aqueous solution of boron compound. Among these, PVA- base resin is preferred. Also, an aqueous boron compound or potassium iodide solution may be added to the PVA resin. The thickness of the adhesive layer after drying is preferably from 0.01 to 10 μm, more preferably from 0.05 to 5 μm.

In the present invention, a drying step of shrinking the stretched film to reduce the volatile content percentage is provided but after attaching a protective film to at least one surface of the film after or during drying, a step of after-heating the film is preferably provided. Specific examples of the method for attaching the protective film include a method of attaching a protective film to the polarizing film using an adhesive while keeping the state of holding both edges of the polarizing film during the drying step and then cutting both edges, and a method of releasing the polarizing film from the both edges-holding part after drying, cutting both edges of the film and attaching a protective film thereto. For cutting edges, a general technique may be used, for example, a method of cutting edges using a cutter such as edged tool or a method of using a laser. The combined films are preferably heated so as to dry the adhesive and improve the polarizing performance. The heating conditions vary depending on the adhesive but in the case of an aqueous adhesive, the heating temperature is preferably 30°C or more, more preferably from 40 to 100°C, still more preferably from 50 to 80°C. These steps are preferably performed in a through production line in view of performance and production efficiency. <Punching>

Fig. 9 shows an example of punching a conventional polarizing plate and Fig. 2 shows an example of punching the polarizing plate of the present invention. In the conventional polarizing plate, as shown in Fig. 9, the absorption axis 71 of polarization, namely, the stretching axis agrees with the longitudinal direction 72, whereas in the polarizing plate of the present invention, as shown in Fig. 2, the absorption axis 81 of polarization, namely, the stretching axis is inclined at 45° with respect to the longitudinal direction 82 and this angle agrees with the angle made, when attached with a liquid crystal cell in LCD, between the absorption axis of the polarizing plate and the vertical or transverse direction of the liquid crystal cell itself, therefore, oblique punching is not necessary in the punching step. Moreover, as seen from Fig. 2, since the polarizing plate of the present invention is cut in a straight line along the longitudinal direction, a practical polarizing plate can also be produced without punching the long polarizing plate but by slitting it along the longitudinal direction and this ensures remarkably high productivity.

The punching may be performed, as described above, either in this stage or after a transparent protective film, a polarizing film and an optical compensating layer are superposed. III. Optical Compensating Layer

The optical compensating layer of the present invention is performed by laying an optical anisotropic layer on a transparent support directly or though an orientation film. The optical compensating layer for use in the present invention is roughly classified into the following two constitutions.

(1) An optical compensating layer characterized in that the optical anisotropic layer is a layer having a negative birefringent property and composed of a compound having a discotic structural unit, the disc plane of the discotic structural unit is inclined with respect to the transparent support plane, and the angle made by the disc plane of the discotic structural unit and the transparent support plane is changed in the depth direction of the optical anisotropic layer. This is called an optical compensating layer-1.

(2) An optical compensating layer characterized in that an orientation film composed of an orientating polymer is provided between a transparent support and an optical anisotropic layer and the polymer of the orientation film and the liquid crystalline compound of the optical anisotropic layer are chemically bonded through the interface of these layers. This is called an optical compensating layer-2. (1) Optical Compensating Layer-1

In the optical compensating layer-1, a layer (optical anisotropic layer) having a negative birefringent property and composed of a compound having a discotic structural unit is proved on a transparent support . <Transparent Support>

As the material for the transparent support, any material may be used insofar as the material is transparent. A material having a light transmittance of 80% or more is preferred and a material exhibiting optical isotropy when viewed from the front surface is more preferred. Accordingly, the transparent support is preferably produced from a material having a small intrinsic birefringence. Examples of such a material which can be used include commercially available products such as ZEONEX, (produced by Nippon Zeon Co., Ltd.), ARTON (produced by JSR) and Fujitac (produced by Fuji Photo Film Co., Ltd.). Also, even a material having a large intrinsic birefringence ratio, such as polycarbonate, polyallylate, polysulfone and polyethersulfone, may be used by appropriately selecting the conditions such as solution casting and melt extrusion and further by setting the stretching conditions in the longitudinal or cross direction. The transparent support for use in the present invention is described in more detail in JP-A-8-50206, paragraphs 0016 to 0028.

The optical anisotropic layer is a layer composed of a liquid crystalline discotic compound having a low molecular weight, such as monomer, or a layer composed of a polymer obtained by the polymerization (hardening) of a polymerizable liquid crystalline discotic compound. Examples of the discotic (disc-like) compound for use in the present invention include benzene derivatives described in the research report by C. Destrade et al., Mol. Cryst., vol. 71, page 111 (1981), truxene derivatives described in the research report by C. Destrade et al., Mol. Cryst., vol. 122, page 141 (1985) and Physics left., A, vol. 78, page 82 (1990), cyclohexane derivatives described in the research report by B. Kohne et al., Angew. Chem. , vol. 96, page 70 (1984), and azacrown-base or phenylacetylene-base macrocycles described in the research report by J.M. Lehn et al., J. Chem. Commun . , page 1794 (1985) and the research report by J. Zhang et al., J. Am. Chem. Soc . , vol. 116, page 2655 (1994). In general, the discotic (disc-like) compound has a structure such that the above-described compound is present as a mother nucleus in the molecular center and a linear alkyl or alkoxy group, a substituted benzoyloxy group or the like is radially substituted thereto as a linear chain. This compound exhibits liquid crystallinity and includes compounds generally called discotic liquid crystal. However, the discotic compound is not limited thereto if the molecular itself has a negative monoaxial property and can impart a constant orientation. In the present invention, the final product formed from the disc-like compound needs not be the above-described compound and includes those where the low molecular discotic liquid crystal has a group capable of reacting under light, heat or the like and is polymerized or crosslinked by a reaction under heat, light or the like to have a high molecular weight and lose the liquid crystallinity.

In the present invention, the optical compensating layer is preferably produced, as described above, by providing an orientation film on a transparent support and then forming an optical anisotropic layer on the orientation film.

The optical anisotropic layer for use in the present invention is a layer having a negative birefringent property and composed of a compound having a discotic structural unit, where the plane of the discotic structural unit is inclined with respect to the transparent support plane and the angle made by the plane of the discotic structural unit and the transparent support plane is changed in the depth direction of the optical anisotropic layer.

The angle (tilt angle) of the plane of the above- described discotic structural unit is generally increased or decreased in the depth direction of the optical anisotropic layer as the distance from the bottom surface of the optical anisotropic layer increases. The tilt angle is preferably increased as the distance increases. Examples of the change of the tilt angle include continuous increase, continuous decrease, intermittent increase, intermittent decrease, change containing continuous increase and continuous decrease, and intermittent change containing increase and decrease. In the intermittent change, a region having no change of the tilt angle is present on the way in the thickness direction. Even if a region having no change is present, the tilt angle as a whole is preferably increased or decreased, more preferably increased. It is particularly preferred that the tilt angle is continuously changed.

Fig. 10 schematically shows a representative example of the cross section of the optical anisotropic layer for use in the present invention. An optical anisotropic layer 103 is provided on an orientation film 102 formed on a transparent support 101. In the liquid crystalline discotic compounds 103a, 103b and 103c constituting the optical anisotropic layer 103, the discotic structural units Pa, Pb and Pc are respectively inclined from the planes 101a, 101b and 101c which are in parallel to the plane of the transparent support 21. Their tilt angles θa, θb and θc (angle made by the plane of the discotic structural unit and the plane of the transparent support) are sequentially increased as the distance from the bottom surface of the optical anisotropic layer increases in the depth (thickness) direction. 104 is a normal line of the transparent support. This liquid crystalline discotic compound is a planar molecule and therefore, the molecule has only one planar face, namely, disc plane (e.g., 101a, 101b, 101c).

The tilt angle (angle) is preferably changed in the range from 5 to 85° (particularly from 10 to 80°) . Also, the tilt angle preferably has a minimum value of 0 to 85° (particularly from 5 to 40°) and a maximum value of 5 to 90° (particularly from 30 to 85°) . In Fig. 10, the tilt angle (e.g., θa) of the discotic structural unit in the support side almost corresponds to the minimum value and the tilt angle (e.g., θc) of the discotic structural unit almost corresponds to the maximum value. The difference between the minimum value and the maximum value of the tilt angle is preferably from 5 to 70° (particularly from 10 to 60°) .

The optical anisotropic layer is generally obtained by a method where a solution prepared by dissolving a discotic compound and other compounds in a solvent is coated on an orientation film, dried, heated to a discotic nematic phase-forming temperature and then cooled while maintaining the orientation state (discotic nematic phase) , or by a method where a solution prepared by dissolving a discotic compound and other compounds (additionally, for example, a polymerizable monomer and a photopolymerization initiator) in a solvent is coated on an orientation film, dried, heated to a discotic nematic phase-forming temperature, polymerized (for example, under the irradiation of UV light) and then cooled. The discotic nematic liquid crystal phase-solid phase transition temperature of the discotic liquid crystalline compound for use in the present invention is preferably from 70 to 300°C, more preferably from 70 to 170°C.

The tilt angle of the discotic unit in the support side can be generally adjusted, for example, by selecting the discotic compound or the material of the orientation film or by selecting the rubbing treatment method. Furthermore, the tilt angle of the discotic unit in the surface side (air side) can be generally adjusted by selecting the discotic compound or other compounds (e.g., plasticizer, surfactant, polymerizable monomer and polymer) used in combination with the discotic compound. The degree of change of the tilt angle can also be adjusted by these selections. (2) Optical Compensating Layer-2

The optical compensating layer-2 comprises a transparent support, an orientation film provided thereon, and an optical anisotropic layer provided on the orientation film. Fig. 11 shows a representative constitution. In Fig. 11, a transparent support 121, an orientation film 122 composed of an oriented polymer, and an optical anisotropic layer 123 as a liquid crystalline compound layer are provided in this order. As for the transparent support, the same transparent support as described above for the optical compensating layer-1 is used.

The orientation film is a layer obtained by orientating a polymer layer.

The optical compensating layer 2 is characterized in that the polymer of the orientation film 102 and the liquid crystalline compound of the optical anisotropic layer 103 are chemically bonded through the interface of these layers. This chemical bonding between two layers is generally formed by the reaction of a polymerizable group of the polymer and the polymerizable group of the liquid crystalline compound. In this case, the optical anisotropic layer is preferably composed of a disc-like liquid crystalline compound having a negative birefringent property. The orientation film (or polymer layer) may also be composed of a polyvinyl alcohol having no polymerizable group and having an aryl group capable of easily orientating the liquid crystalline compound. <Orientation Film>

The orientation film for use in the present invention is provided on a transparent support. The orientation film has a function of regulating the orientation direction of the liquid crystalline compound such as disc-like liquid crystalline compound, provided thereon by coating and the orientation gives an optical axis inclined from the optical anisotropic layer. In the present invention, the orientation film is a polymer layer subjected to an orientation treatment such as rubbing treatment and the polymer has a group having vinyl, oxylanyl, aziridinyl or aryl. The polymer is preferably polyvinyl alcohol. The orientation film is described below by referring to the case of polyvinyl alcohol. In the polyvinyl alcohol for use in the present invention, at least one hydroxyl group is substituted by a group having a vinyl moiety, an oxylanyl moiety or an aziridinyl moiety. Such a moiety is generally bonded to the polymer chain (carbon atom) of the polyvinyl alcohol through an ether bond (-0-), a urethane bond (-OCONH-), an acetal bond ((-0-)₂CH-) or an ester bond (-OCO-) [namely, a bond group) . Among these, a urethane bond, an acetal bond and an ester bond are preferred. The vinyl, oxylanyl, aziridinyl or aryl is preferably bonded to the polyvinyl alcohol indirectly through the above-described bond. In other words, a group having such a moiety is preferably bonded together with the bond group to the polyvinyl alcohol.

Preferred examples of the polyvinyl alcohol include the polyvinyl alcohols represented by formulae (I), (II), (III), (la), (Ha) and (Ilia) of JP-A-9-152509. Specific examples thereof include the compounds described in paragraphs 0060 to 0066 and 0072 to 0095 of JP-A-9-152509, The synthesis methods therefor are described in paragraphs 0070 and 0096 to 0120 of that patent publication . <Optical Anisotropic Layer>

The optical anisotropic layer in the optical compensating layer-2 can be obtained by forming a liquid crystalline compound layer (optical anisotropic layer) on the orientation film. The liquid crystalline compound may be either a rod-like liquid crystalline compound or a disc-like liquid crystalline compound but is preferably a disc-like liquid crystalline compound. The liquid crystalline compound preferably has a polymerizable group for making chemical bonding with the polymer of the orientation film. These liquid crystalline compounds are described, for example, in Kikan Kagaku Sosetsu, "Ekisho no Kagaku" (Quarterly, Elements of Chemistry, "Chemistry of Liquid Crystal"), No. 22, Nippon Kagaku Kai (compiler) (1994). Also, these compounds and specific examples thereof are described in paragraphs 0126 to 0144 of JP-A- 9-152509. <Antiglare Antireflective Film>

The antireflective film is described below. In the present invention, the antireflective film can be constituted by sequentially providing an antiglare or light-scattering film and at least one low refractive index layer on a substrate. If desired, a hard coat layer or the like may be further provided. Fig. 13 shows one example of the antireflective film of the present invention and this embodiment has a layer structure of a substrate 1, a hard coat layer 2, an antiglare or light- scattering film 3 and a low refractive index layer 4 in this order. The numeral 5 is an antiglare particle and its protruded part from the antiglare or light-scattering film is also covered with the low refractive index layer 4. The refractive index of the binder in the antiglare or light-scattering film is from 1.57 to 2.00 and the refractive index of the low refractive index layer is from 1.38 to 1.49. -Low Refractive Index Layer-

The antireflection of the present invention is attained by making use of an interference phenomenon and it is important to cause an interference phenomenon in the visible region, particularly in the wavelength region of 450 to 680 nm. For this purpose, the low refractive index layer of the antireflective film preferably satisfies the following formula (I): mλ/4x0.7<nιdι<mλ/4xl.3 (I) wherein m is an odd number (generally 1), ni is a refractive index of the low refractive index layer, di is a film thickness (nm) of the low refractive index layer, and λ is a wavelength of the incident light.

In the present invention, the low refractive index layer contains a fluorine-containing resin, preferably a fluorine-containing compound (resin) capable of crosslinking by heat or ionizing radiation.

The refractive index of the low refractive index layer containing a fluorine-containing resin is from 1.38 to 1.49, preferably from 1.38 to 1.45. If this value is too low, the film strength decreases, whereas if too high, the antireflection property changes for the worse.

The coefficient of dynamic friction of this layer is preferably from 0.03 to 0.15, more preferably from 0.07 to 0.10. If the coefficient of dynamic friction is too small, the layer readily slips and slippage becomes a problem, whereas if too large, the scratch resistance decreases .

Furthermore, the contact angle with water of this layer is preferably from 90 to 120°, more preferably from 100 to 120°. If this is too small, the antifouling property becomes poor.

Examples of the crosslinking fluorine-containing polymer compound contained in the low refractive index layer include perfluoroalkyl group-containing silane compounds (e.g., (heptadecafluoro-1 , 1 , 2 , 2-tetradecyl ) tri- ethoxysilane ) and fluorine-containing copolymers having a fluorine-containing monomer component and a monomer component for imparting a crosslinking group as the constituent components.

Specific examples of the fluorine monomer component include fluoroolefins (e.g., fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2, 2-dimethyl-1 , 3-dioxol) ,

(meth) acrylic acid partial or complete fluorinated alkyl ester derivatives (e.g., BISCOTE 6FM (produced by Osaka Yuki Kagaku) , M-2020 (produced by Daikin) ) and complete or partial fluorinated vinyl ethers.

Examples of the monomer component for imparting a crosslinking group include (meth) acrylate monomers previously having a crosslinking functional group within the molecule, such as glycidyl methacrylate, and

(meth) acrylate monomers having a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group or the like, such as (meth) acrylic acid, methylol

(meth) acrylate, hydroxyalkyl (meth) acrylate and allyl acrylate. In the latter case, it is known in JP-A-10- 25388 and JP-A-10-147739 that a crosslinked structure can be introduced after the copolymerization . Not only a polymer having the above-described fluorine monomer as the constituent unit but also a copolymer with a monomer not containing a fluorine atom may be used. The monomer unit which can be used in combination is not particularly limited and examples thereof include olefins (e.g., ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride), acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, 2- ethylhexyl acrylate), methacrylic acid esters (e.g., methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene, glycol dimethacrylate) , styrene derivatives (e.g., styrene, divinylbenzene, vinyltoluene, α-methylstyrene) , vinyl ethers (e.g., methyl vinyl ether), vinyl esters (e.g., vinyl acetate, vinyl propionate, vinyl cinnamate), acrylamides (e.g., N-tert- butylacrylamide, N-cyclohexylacrylamide) , methacrylamides and acrylonitrile derivatives.

The thickness of the low refractive index layer is preferably from 0.08 to 0.15 μm, more preferably from 0.09 to 0.12 μm.

Also, two or more low refractive index layers different in the constituent components and having a refractive index specified in the present invention may be provided. -Antiglare Layer-

The refractive index of the binder constituting the antiglare or light-scattering film for use in the present invention is from 1.57 to 2.00, preferably from 1.60 to 1.80. If this is too low or too high, the antireflection property decreases. Examples of the binder include polymers having a saturated hydrocarbon or a polyether as the main chain. A polymer having a saturated hydrocarbon as the main chain is preferred. Furthermore, the polymer is preferably crosslinked.

The polymer having a saturated hydrocarbon as the main chain is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer. For obtaining a crosslinked polymer, a monomer having two or more ethylenically unsaturated groups is preferably used.

Examples of the monomer having two or more ethylenically unsaturated groups include esters of a polyhydric alcohol and a (meth) acrylic acid (e.g., ethylene glycol di (meth) acrylate, 1 , 4-cyclohexane diacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1, 2, 3-cyclohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate) , vinylbenzene and derivatives thereof (e.g., 1, 4-divinylbenzene, 4- vinylbenzoic acid-2-acryloyl ethyl ester, 1,4- divinylcyclohexanone) , vinylsulfones (e.g., divinylsulfone) , acrylamides (e.g., methylenebisacrylamide) and methacrylamides .

After the coating, this monomer having an ethylenically unsaturated group needs be hardened through a polymerization reaction by ionizing radiation or heat. This reaction can be performed by a well-known method using, if desired, a photopolymerization initiator or a photosensitizer .

In place of or in addition to the monomer having two or more ethylenically unsaturated groups, a crosslinked structure may be introduced into the polymer by the reaction of a crosslinking group. Examples of the crosslinking functional group include an isocyanate group, an epoxy group, an aziridine group, an oxazoline group, an aldehyde group, a carbonyl group, a hydrazine group, a carboxyl group, a methylol group and an active methylene group. Also, a vinylsulfonic acid, an acid anhydride, a cyanoacrylate derivative, a melamine, an etherified methylol, ester and urethane, and a metal alkoxide such as tetramethoxysilane can be used as the monomer for introducing a crosslinked structure. A functional group of exhibiting a crosslinking property as a result of the decomposition reaction, such as block isocyanate group, can also be used. In the present invention, the crosslinking group is not limited to the above-described compounds but may be a group of exhibiting a reactivity as a result of the decomposition of the functional group. After the coating, this compound having a crosslinking group needs be crosslinked by heat or the like.

The polymer having a polyether as the main chain is preferably synthesized by an ring opening polymerization reaction of a polyfunctional epoxy compound.

In the present invention, for the purpose of allowing the binder of the antiglare or light-scattering film to have a refractive index in the above-described range, the binder may also be formed by using a high refractive index monomer or a high refractive index inorganic ultrafine particle in addition to the monomer described above.

The high refractive index monomer preferably contains in the monomer structure at least one member selected from an aromatic ring, a halogen atom except for fluorine atom, a sulfur atom, a phosphorus atom and a nitrogen atom. Examples of the high refractive index monomer include bis ( -methacryloylthiophenyl ) sulfide, vinylnaphthalene, vinylphenyl sulfide and 4- methacryloxyphenyl-4 ' -methoxyphenyl thioether. In the present invention, the amount of the high refractive index monomer used is adjusted such that the binder has the objective refractive index.

The high refractive index inorganic ultrafine particle is preferably an ultrafine particle composed of an oxide of at least one member selected from titanium, aluminum indium, zinc, tin, antimony and zirconium, and having a particle size of 100 nm or less, more preferably 50 nm or less. Examples of this ultrafine particle include Ti0₂, A1₂0₃, ln₂0₃, ZnO, Sn0₂, Sb₂0₃, ITO and Zr0₂. The content of the inorganic ultrafine particle in the binder is preferably from 10 to 90 wt%, more preferably from 20 to 80 wt%, based on the entire weight of the antiglare or light-scattering film.

In the case where the binder is composed of a monomer having two or more ethylenically unsaturated groups and the above-described high refractive index fine particle, scattering does not occur because the particle size of the fine particle is sufficiently small than the wavelength of light and the binder behaves optically as a homogeneous substance. This is described, for example, in JP-A-8-110401.

In the antiglare or light-scattering film, an antiglare particle composed of a resin or an inorganic compound is further used for the purpose of imparting antiglare property, preventing the reflectance from worsening due to the interference with the lower layer, and preventing occurrence of uneven color.

In the present invention, surface scattering occurs due to antiglare particles dispersed in the binder and therefore, the antiglare or light-scattering film is free from effect of optical interference. If an antiglare particle is not contained, optical interference occurs due to the difference in the refractive index from the lower layer and therefore, the reflectance greatly varies because of its wavelength dependency, as a result, the antiglare antireflective effect decreases and at the same time, uneven color is generated. However, in the present invention, these problems are overcome by virtue of the scattering effect by the surface irregularities of the antiglare or light-scattering film.

The average particle size of the antiglare particle is preferably from 1.0 to 10.0 μm, more preferably from 1.5 to 5.0 μm. The proportion of antiglare particles having a particle size smaller than the film thickness of the binder in the antiglare or light-scattering film is preferably less than 50% (by weight) of all antiglare particles. The amount of the antiglare particle coated is preferably from 10 to 1,000 mg/m², more preferably from 30 to 100 mg/m². The particle size distribution can be measured by a Coulter counter method, a centrifugal precipitation method or the like but the distribution is calculated in terms of the particle number distribution.

The thickness of the antiglare or light-scattering film is preferably from 0.5 to 10 μm, more preferably from 1 to 5 μm. Also, the difference in the refractive index between the binder and the antiglare particle in the antiglare or light-scattering film is preferably less than 0.05 for reducing the internal scattering within the antiglare or light-scattering film. -Substrate-

In the present invention, as the substrate used for the antireflective film, a preferred substrate is appropriately selected. Specifically, a transparent support is used. The transparent support is preferably a plastic film. Examples of the polymer constituting the plastic film include cellulose esters (e.g., triacetyl cellulose, diacetyl cellulose), polyamide, polycarbonate, polyesters (e.g., polyethylene terephthalate, polyethylene naphthalate) , polystyrene and polyolefin. Among these, triacetyl cellulose is preferred.

The triacetyl cellulose is preferably used as the protective film for protecting the polarizing film of the polarizing plate and therefore, using this protective film as the substrate, the antireflective film may be provided on this protective film as it is and this is preferred in view of cost. -Hard Coat Layer- In the present invention, a hard coat layer can be arbitrarily provided between the antiglare or light- scattering film and the substrate. One hard coat layer may be provided or two or more layers different in the constituent components may be provided.

Examples of the compound constituting the hard coat layer includes, similarly to the binder of the antiglare or light-scattering film, polymers having a saturated hydrocarbon or a polyether as the main chain.

The thickness of the hard coat layer is preferably from 1 to 10 μm, more preferably from 3 to 6 μm. -Formation Method- Each layer of the antireflective film can be formed by the coating using a dip coat method, an air knife coat method, a curtain coat method, a roller coat method, a wire bar coat method, a gravure coat method or an extrusion coat method (see, U.S. Patent 2,681,294). Two or more layers may be coated simultaneously. The simultaneous coating method is described in U.S. Patents 2,761,791, 2,941,898, 3,508,947 and 3,526,528 and Yuji Harasaki, Coating Kogaku (Coating Engineering) , page 253, Asakura Shoten (1973) .

[Examples]

The present invention is described in greater detail below by referring to Examples, however, the present invention is not limited thereto.

[Examples 1 to 4 and Comparative Example 1] <Manufacture of Polarizing Film>

Both surfaces of a PVA film were washed with ion exchanged water at a water flow rate of 2 liter/min and water on the surface was splashed out by air blowing to reduce the foreign matters adhering to the surface to 0.5% or less. This PVA film was dipped in an aqueous solution containing 1.0 g/liter of iodine and 60.0 g/liter of potassium iodide at 25°C for 90 seconds and further dipped in an aqueous solution containing 40 g/liter of boric acid and 30 g/liter of potassium iodide at 25°C for 120 seconds. Subsequently, the film was introduced into a tenter stretching machine in the form of Fig. 3 and after once stretched to 7.0 times in an atmosphere of 45°C and 95%, shrunk to 5.3 times. Thereafter, while keeping constant the width, the film was dried at 80°C and removed from the tenter. The water content percentage of the PVA film was 30% before the initiation of stretching and 1.5% after the drying. The elastic modulus of the PVA film before stretching was 35 MPa in an atmosphere of 40°C and 95%.

The difference in the conveyance speed between right and left tenter clips was less than 0.05% and the angle made by the center line of film introduced and the center line of film delivered to the next step was 0°. Here, |Ll-L2| was 0.7 m, W was 0.7 m and a relationship of |L1-L2|=W was established. At the outlet of the tenter, wrinkling and deformation of film were not observed. <Attachment of Transparent Protective Film>

On both surfaces of the film, saponified Fujitac (cellulose triacetate, retardation value: 3.0 nm) produced by Fuji Photo Film Co., Ltd. was attached using as the adhesive an aqueous solution containing 3% of PVA (PVA-117H produced by Kuraray Co., Ltd.) and 4% of potassium iodide and the combined films were heated at 60°C for 30 minutes to obtain a polarizing film with a transparent protective film, having an effective width of 650 mm. The attached state was good.

The absorption axis direction of the obtained polarizing film with a transparent protective film was inclined at 45° with respect to the longitudinal direction and also inclined at 45° with respect to the phase lag axis of Fujitac. The transmittance of this polarizing film at 550 nm was 41.3% and the polarization degree was 99.60% .

Furthermore, the polarizing film was cut into a size of 310x233 mm as in Fig. 2, as a result, a polarizing film having an absorption axis inclined at 45° with respect to the side could be obtained with an area efficiency of 91.5%. Colorless spots and streaks were not observed with an eye.

Manufacture of Optical Compensating' Layer> (Formation of Orientation Film)

Fujitac (cellulose triacetate) produced by Fuji Photo Film Co., Ltd. was fixed as a transparent support on a coating bed and thereon, the following coating solution containing a polyvinyl alcohol shown in Table 1 was coated by a bar coater and dried under heating at 80°C for 10 minutes to form a polymer layer having a thickness of 0.8 μm (hereinafter, "parts" means "parts by weight" ) . Composition of Coating Solution:

Polyvinyl alcohol shown in Table 1 1.0 part Water 18.0 parts

Methanol 6.0 parts

The surface of the obtained polymer layer was rubbed while inclining it at 45° with respect to the longitudinal conveyance direction under the conditions such that the outer diameter of the rubbing roll was 80 mm, the glass substrate conveyance speed was 100 m/min, the rotation number of the rubbing roll was 1,000 rpm and the substrate conveyance tension was 9.8 N/cm-substrate width, thereby forming an orientation film.

(Formation of Disc-Like Liquid Crystalline Compound Layer (Optical Anisotropic Layer) )

On the orientation film of the glass substrate after the rubbing treatment, a methyl ethyl ketone 10 wt% solution of 1, 2 , 1 ' , 2 ' , 1" , 2"-tris [4 , 5-di (vinyloxycarbonyl- ethoxybenzoyloxy) phenylene (Compound TP-3 described in the paragraph 0133 of JP-A-9-152509) was coated at 3,000 rpm by a spin coater and dried to form a disc-like liquid crystalline compound layer (optical anisotropic layer) .

(Evaluation of Orientation of Disc-Like Liquid Crystalline Compound Layer)

While heating the transparent support having provided thereon an orientation film and an optical anisotropic layer on a hot stage (Model FP82, manufactured by Metier) , the orientation state of the optical anisotropic layer was observed using a polarizing microscope (OPTIPHOT-POL, manufactured by Nippon Kogaku K.K.). The optical anisotropic layers obtained in Examples 1 to 4 were bright even when viewed in a cross- Nicol state, and were revealed to exhibit optical anisotropy. The results on the observation of those optical anisotropic layers are shown in Table 1.

[Table 1]

Table 1

Example Polymer Orientation

Example 1 P-l uniform orientation

Example 2 P-2 uniform orientation

Example 3 P-3 uniform orientation

Example 4 P-4 uniform orientation

Comparativ MP-203 (produced Schlieren e Example by Kuraray Co., structure 1 Ltd.) remained.

Polymer compounds P-l, P-2, P-3 and P-4 used each had a structure shown below and synthesized by the method described in paragraphs 0101 to 0110 of JP-A-9-152509.

Polymer MP-203 for comparison was commercially available methacryloyloxy-modified polyvinyl alcohol (substitution ratio: 1.7 mol%). (P-l)

x=86.3, y=1.7, z=12 (mol%)

(P-2, P-3]

CH₂CH)- 4 CH)-

OH 0

P-2: x=87.8, y=0.2, z=12 (mol%) P-3: x=87.2, y=0.8, z=12 (mol%)

( P- 4 )

— (- CH₂CH) ^■ CH₂-

OH

x=87 . 2 , y=0 . 8 , z=12 (mol% ) , n=4 , R=H

On the surface of the obliquely stretched film attached with the transparent protective film, in the side opposite the transparent protective film, the optical compensating layer obtained by superposing the transparent support, the polarizing film and the optical anisotropic layer was stacked to bring the surface in the transparent support side into contact with the obliquely stretched polarizing film, and bonded using a 0.5 wt% acetone "methanol (50*50) mixed solution of each of polyvinyl alcohol and triacetyl cellulose to obtain a polarizing film of the present invention. <Results>

The polarizing film of the present invention manufactured above was obliquely stretched by the method shown in Fig. 3, as a result, a polarizing plate having an absorption axis inclined at 45° with respect to the side could be obtained with an area efficiency of 91.5% and the polarizing plate had a view angle enlarging function and uniform orientation.

[Examples 5 to 8]

Both surfaces of a PVA film were washed with ion exchanged water at a water flow rate of 2 liter/min and water on the surfaces was splashed out by air blowing to reduce the foreign matters adhering to the surface to 0.5% or less. This PVA film was then dipped in an aqueous solution containing 1.0 g/liter of iodine and 120.0 g/liter of potassium iodide at 40°C for 90 seconds and further dipped in an aqueous solution containing 40 g/liter of boric acid and 30 g/liter of potassium iodide at 40°C for 60 seconds. Subsequently, the film was introduced into a tenter stretching machine in the form of Fig. 4 and stretched to 4.5 times, and then the tenter was bent as shown in Fig. 4 with respect to the stretching direction. Thereafter, while keeping constant the width and shrinking the film, the film was dried in an atmosphere of 80°C and removed from the tenter. <Attachment of Transparent Protective Film>

The edges of 3 cm in the cross direction of the obliquely stretched polarizing film obtained above were cut using a cutter and on both surfaces thereof, saponified Fujitac (cellulose triacetate) produced by Fuji Photo Film Co., Ltd. was attached using as the adhesive an aqueous solution containing 3% of PVA ( PVA- 117H produced by Kuraray Co., Ltd.) and 4% of potassium iodide. Then, the combined films were heated at 60°C for 30 minutes to obtain a polarizing film having an effective width of 650 mm and having a cellulose triacetate protective film on both surfaces thereof.

The water content percentage of the PVA film was 32% before the initiation of stretching and 1.5% after the drying. The difference in the conveyance speed between right and left tenter clips was less than 0.05% and the angle made by the center line of film introduced and the center line of film delivered to the next step was 46°. Here, | L1-L2 | was 0.7 m, W was 0.7 m and a relationship of |L1-L2|=W was established. At the outlet of the tenter, the substantial stretching direction Ax-Cx was inclined at 45° with respect to the center line 22 of film delivered to next step. Wrinkling and deformation of film were not observed at the tenter outlet.

The absorption axis direction of the obtained polarizing film was inclined at 45° with respect to the longitudinal direction and. The transmittance of this polarizing film at 550 nm was 42.3% and the polarization degree was 99.97%. Furthermore, the polarizing film was cut into a size of 310x233 mm as in Fig. 2, as a result, a polarizing film having an absorption axis inclined at

45° with respect to the side could be obtained with an area efficiency of 91.5%. Colorless spots and streaks were not observed with an eye.

(Formation of Orientation Film)

Fujitac (cellulose triacetate) produced by Fuji Photo Film Co., Ltd. was fixed as a transparent support on a coating bed and thereon, one of the coating solutions containing 4 kinds of polyvinyl alcohol used in Examples 1 to 4 was coated by a bar coater and dried under heating at 80°C for 10 minutes to form a polymer layer having a thickness of 0.8 μm (hereinafter, "parts" means "parts by weight").

On the orientation film of the glass substrate after the rubbing treatment, a coating solution for a disc-like liquid crystalline compound layer, having the following composition, was coated at 3,000 rpm by a spin coater and dried to form a disc-like liquid crystalline compound layer (optical anisotropic layer) . Composition of Coating Solution:

Cellulose acetate butyrate (CAB531, 12 parts produced by Eastman Chemical)

Discotic liquid crystalline compound 100 parts (same compound as in Examples 1 to 4, namely, TP-3)

Tripropylene glycol diacrylate (SR306, produced by Somar)

Photopolymerization initiator 2 parts

(Irgacure 907, produced by Nippon Ciba Geigy)

Methyl ethyl ketone 400 parts

The film having this coated layer was passed through a heating zone at 140°C over 2 minutes and subsequently, UV light was irradiated on the coated layer to cure it, thereby forming a thin layer (optical anisotropic layer, thickness: 2 μm) where the orientation state of the oriented disc-like liquid crystal compound was fixed .

(Evaluation of Orientation of Disc-Like Liquid Crystalline Compound Layer)

While heating the transparent support having provided thereon an orientation film and an optical anisotropic layer on a hot stage (Model FP82, manufactured by Metier) , the orientation state of the optical anisotropic layer was observed using a polarizing microscope (OPTIPHOT-POL, manufactured by Nippon Kogaku K.K.). The optical anisotropic layers obtained in Examples 5 to 8 were bright even when viewed in a cross- Nicol state, and were revealed to exhibit optical anisotropy. The results on the observation of those optical anisotropic layers are shown in Table 2.

Table 2

Example Polymer Layer Orientation Example 5 P- -1 uniform orientation

Example 6 P- -2 uniform orientation

Example 7 P- -3 uniform orientation

Example 8 P- -4 uniform orientation

On the surface of the obliquely stretched film attached with the transparent protective film, in the side opposite the transparent protective film, the roll- form optical compensating layer obtained by superposing the transparent support, the polarizing film and the optical anisotropic layer was stacked to agree the stretching direction of the polarizing film with the rubbing direction of the optical compensating layer, and roll-to-roll bonded using an aqueous solution containing 3% of PVA (PVA-117H produced by Kuraray Co., Ltd.) and 4% of potassium iodide to obtain a roll-form polarizing plate of the present invention. <Results>

The polarizing plate of the present invention manufactured above was cut into a size of 310x233 mm as in Fig. 2, as a result, a polarizing film having an absorption axis inclined at 45° with respect to the side could be obtained with an area efficiency of 91.5%.

[Comparative Example 2]

Both surfaces of a PVA film were washed with ion exchanged water at a water flow rate of 2 liter/min and water on the surfaces was splashed out by air blowing to reduce the foreign matters adhering to the surface to 0.5% or less. This PVA film was then dipped in an aqueous solution containing 1.0 g/liter of iodine and 120.0 g/liter of potassium iodide at 40°C for 90 seconds, further dipped in an aqueous solution containing 40 g/liter of boric acid and 30 g/liter of potassium iodide at 40°C for 60 seconds and then dried at 60°C for 10 minutes. The water content percentage of the PVA film was 1%. Subsequently, the PVA film was introduced into a tenter stretching machine in the form of Fig. 4 and stretched to 4.5 times, and then the tenter was bent as shown in Fig. 4 with respect to the stretching direction. Thereafter, while keeping constant the width and shrinking the film, the film was dried in an atmosphere of 80°C and removed from the tenter. Wrinkling remained over the entire surface of the film and a polarizing film having a coarse surface was obtained.

On both surfaces of this film, a transparent protective film was provided in the same manner as in Examples 5 to 8 to obtain a polarizing film with a transparent protective film. This polarizing film with a transparent protective film and the optical compensating layer manufactured in Example 5 were attached in the same manner as in Example 5 to manufacture the polarizing film of Comparative Example 2.

In the obtained polarizing plate having a view angle enlarging function, the polarizing film had wrinkles and therefore, poorly adhered to the protective film, as a result, the optical compensating layer had bad planeness and the view field enlarged in the view angle was seriously unclear.

[Example 9]

The polarizing film with a transparent protective film manufactured in the same manner as in Examples 1 to 4 and an optical compensating layer having a view angle enlarging function manufactured by the following method were attached in the same manner as in Examples 1 to 4 to prepare a polarizing plate.

On a 120 μm-thick triacetyl cellulose film (produced by Fuji Photo Film Co., Ltd.) having provided thereon a gelatin thin film (0.1 μm) , a linear alkyl- modified polyvinyl alcohol (MP203, produced by Kuraray Co., Ltd., described above) was coated, dried with hot air at 80°C and then subjected to a rubbing treatment to form an orientation film. The orientation state is described below by referring to Fig. 12, which is an explanatory view showing the steric axis direction in the film. Assuming that main refractive indices in plate are nx and ny, the refractive index in the thickness direction is nz and the thickness is d, | nx-ny | xd and { (nx+ny) /2-nz }xd of the triacetyl cellulose film were determined. By measuring the thickness using a micrometer and measuring Re from various directions using an ellipsometer (AEP-100, manufactured by Shimadzu Corporation), those |nx-ny|xd and { (nx+ny) /2-nz } xd were determined. The |nx-ny|xd of the triacetyl cellulose film was 3 nm and the { (nx+ny) /2-nz } xd was 60 nm. Accordingly, the triacetyl cellulose film was almost negatively monoaxial and the optical axis ran nearly in the normal direction of the film.

On this orientation film, a coating solution obtained by dissolving 1.6 g of the above-described liquid crystalline discotic compound 1 , 2 , 1 ' , 2 ' , 1" , 2 "- tris[4,5-di(vinylcarbonyloxybutoxybenzoyloxy)phenylene (Compound TE-8 described in the paragraph 0044 of JP-A-8- 50206 (8, m=4)), 0.4 g of phenoxydiethylene glycol acrylate (M101, produced by Toa Gosei Chemical Industry Co., Ltd.), 0.05 g of cellulose acetate butyrate (CAB531- 1, produced by Eastman Chemical) and 0.01 g of a photopolymerization initiator (Irgacure 907, produced by Ciba Geigy) in 3.65 g of methyl ethyl ketone was coated by a wire bar (#4 bar). Then, the film was attached and thereby fixed to a metal frame, heated in a high- temperature tank at 120°C for 3 minutes to orient the discotic compound, and allowed to cool to room temperature, thereby forming a 1.8 μm-thick discotic compound-containing layer (optical anisotropic layer) . Thus, the optical compensating layer having an optical anisotropic layer of the present invention was manufactured.

The obtained optical anisotropic layer according to the present invention was cut in the rubbing direction along the depth using a microtome to obtain a very thin film (sample. This sample was allowed to stand in an Os0₄ atmosphere for 48 hours and thereby dyed. The resulting dyed film was observed by a transmission electron microscope (TEM) and a microscopic photograph thereof was obtained. In the dyed film, the acryloyl group of the discotic compound was dyed and observed as an image on the photograph. It was seen from this photograph that the discotic compound of the optical anisotropic layer was inclined from the surface of the transparent support and the tilt angle thereof was continuously increased in the range from 5 to 65° as the distance in the depth direction from the bottom of the optical anisotropic layer was increased.

[Example 10]

Both surfaces of a PVA film were washed with ion exchanged water at a water flow rate of 2 liter/min and water on the surface was splashed out by air blowing to reduce the foreign matters adhering to the surface to 0.5% or less. This PVA film was dipped in an aqueous solution containing 1.0 g/liter of iodine and 60.0 g/liter of potassium iodide at 25°C for 90 seconds and further dipped in an aqueous solution containing 40 g/liter of boric acid and 30 g/liter of potassium iodide at 25°C for 120 seconds. Subsequently, the film was introduced into a tenter stretching machine in the form of Fig. 3 and after once stretched to 7.0 times in an atmosphere of 40°C and 95%, shrunk to 5.3 times. Thereafter, while keeping constant the width, the film was dried at 60°C and removed from the tenter. The water content of PVA film was 30% before the initiation of stretching and 1.5% after the drying.

The difference in the conveyance speed between right and left tenter clips was less than 0.05% and the angle made by the center line of film introduced and the center line of film delivered to the next step was 0°. Here, |L1-L2| was 0.7 m, W was 0.7 m and a relationship of |L1-L2|=W was established. At the outlet of the tenter, wrinkling and deformation of film were not observed. The stretching axis of obtained Polarizing Plate A was inclined at 45° with respect to the longitudinal direction.

Separately, the following coating solution for hard coat layer was coated using a bar coater on Fujitac (cellulose triacetate, retardation value: 3.0 nm) produced by Fuji Photo Film Co., Ltd., dried at 120°C and hardened by irradiating an ultraviolet ray at an illuminance of 400 mW/cm² and a dose of 300 mJ/cm² using an air cooled metal halide lamp of 160 W/cm (manufactured by I-Graphics K.K.) to form a hard coat layer having a thickness of 4 μm. Thereon, the following coating solution for antiglare or light-scattering film was coated using a bar coater and under the same conditions as above for the hard coat layer, dried and hardened with ultraviolet ray to form an antiglare or light-scattering film having a thickness of about 1.5 μm. Further thereon, the following coating for low refractive index layer was coated using a bar coater, dried at 80°C and thermally crosslinked at 120°C for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. Thus, Antiglare Antireflective Film B consisting of a hard coat layer, an antiglare or light-scattering film and a low refractive index layer was produced. (Preparation of Coating Solution for Antiglare Layer)

In a mixed solvent containing 104.1 g of cyclo- hexanone and 61.3 g of methyl ethyl ketone, 217.0 g of a zirconium oxide (particle size: about 30 nm) dispersion- containing hard coat coating solution (KZ-7886A, trade name, produced by JSR) was added while stirring by an air device. Incidentally, the coating film obtained by coating this solution and curing it with ultraviolet ray had a refractive index of 1.61. To this solution, 5 g of a crosslinked polystyrene particle (SX-200H, trade name, produced by Soken Kagaku K.K.) having a particle size of 2 μm was added and dispersed by stirring with a highspeed device at 5,000 rpm, and the resulting dispersion was filtered through a polypropylene-made filter having a pore size of 30 μm to prepare a coating solution for antiglare or light-scattering film. (Coating Solution for Hard Coat Layer)

250 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, produced by Nippon Kayaku K.K.) was dissolved in a mixed solvent of methyl ethyl ketone/cyclohexanone (=50/50 in % by weight) . To the obtained solution, a solution prepared by dissolving 7.5 g of a photopolymerization initiator (Irgacure 907, produced by Ciba Geigy) and 5.0 g of a photosensitizer (Kayacure DETX, produced by Nippon Kayaku K.K.) in 49 g of methyl ethyl ketone was added. Incidentally, the coating film obtained by coating the resulting solution and curing it with ultraviolet ray had a refractive index of 1.53. This solution was filtered through a polypropylene-made filter having a pore size of 30 μm to prepare a coating solution for hard coat layer. (Preparation of Coating Solution for Low Refractive Index Layer)

To 200 g of a heat-crosslinking fluorine-containing polymer having a refractive index of 1.46 (JN-7221, produced by JSR) , 200 g of methyl isobutyl ketone was added and stirred. The obtained solution was filtered through a polypropylene-made filter having a pore size of 1 μm to prepare a coating solution for low refractive index layer.

While running Polarizing Plate A and Antiglare Antireflective Film B in the longitudinal direction, these were attached using an aqueous 3% PVA (PVA-117H, produced by Kuraray Co., Ltd.) solution as the adhesive and dried at 80°C to obtain a polarizing plate having an antireflective film and having an effective width of 650 mm.

This polarizing plate was cut into a size of 310x233 mm as in Fig. 2, as a result, a polarizing plate having an area efficiency of 91.5% and having an absorption axis inclined at 45° with respect to the side could be obtained.

The spectral reflectance at an incident angle of 5° on the surface having the antireflective film of the obtained polarizing plate was measured using an spectrophotometer (manufactured by Nippon Bunko K.K.) and the average reflectance in the range from 450 to 650 nm was determined and found to be 1.7%.

For evaluating the antiglare property, an uncovered fluorescent lamp (8,000 cd/m²) without a louver was reflected on the same surface and the reflected image was observed, as a result, the contour of fluorescent lamp was not recognized at all.

For evaluating the scratch resistance, the pencil hardness evaluation method described in JIS K 5400 was performed on the surface having the antireflective film, as a result, the pencil hardness was 3H.

For evaluating the antifouling property, the polarizing plate was subjected to humidity conditioning at 25°C and 60% RH for 2 hours and evaluated on the contact angle with water, as a result, the contact angle was 103°. Furthermore, after the humidity conditioning under the same conditions, the coefficient of dynamic friction was measured by a dynamic friction measuring machine HEIDON-14 (trade name) using a 5 mmφ stainless steel ball under a load of 100 g at a rate of 60 cm/min and found to be 0.08.

[Example 11]

Both surfaces of a PVA film were washed with ion exchanged water at a water flow rate of 2 liter/min and water on the surface was splashed out by air blowing to reduce the foreign matters adhering to the surface to 0.5% or less. This PVA film was dipped in an aqueous solution containing 1.0 g/liter of iodine and 120.0 g/liter of potassium iodide at 40°C for 90 seconds and further dipped in an aqueous solution containing 40 g/liter of boric acid and 30 g/liter of potassium iodide at 40°C for 60 seconds. Subsequently, the film was introduced into a tenter stretching machine in the form of Fig. 4 and stretched to 4.5 times. The tenter was bent as shown in Fig. 4 with respect to the stretching direction and thereafter, while keeping constant the width and undergoing shrinking, the film was dried in an atmosphere of 80°C and removed from the tenter. The edges of 3 cm in the cross direction were cut using a cutter and while running the film, saponified Fujitac (cellulose triacetate, retardation value: 3.0 nm, the stretching axis is in parallel to the longitudinal direction) produced by Fuji Photo Film Co., Ltd. was attached to one surface using an aqueous 3% PVA (PVA-117H produced by Kuraray Co., Ltd.) solution as the adhesive and Antiglare Antireflective Film B prepared in Example 10 was attached to another surface using the same aqueous 3% PVA solution as the adhesive. The resulting laminate was heated at 60°C for 30 minutes to obtain a polarizing plate having an effective width of 650 mm. Since the surface was smooth, the films were satisfactorily attached.

The water content of PVA film was 32% before the initiation of stretching and 1.5% after the drying. The difference in the conveyance speed between right and left tenter clips was less than 0.05% and the angle made by the center line of film introduced and the center line of film delivered to the next step was 46°. Here, |L1-L2| was 0.7 m, W was 0.7 m and a relationship of |L1-L2|=W was established. The substantial stretching direction Ax-Cx at the tenter outlet was inclined at 45° with respect to the center line 22 of film delivered to the next step. At the outlet of the tenter, wrinkling and deformation of film were not observed.

The absorption axis direction of the obtained polarizing plate was inclined at 45° with respect to the longitudinal direction and also inclined at 45° with respect to the phase lag axis of Fujitac. The transmittance of this polarizing plate at 550 nm was 41.3% and the polarization degree was 99.60%.

The obtained polarizing plate was treated at 40°C and a relative humidity of 30% for 100 hours in a dry constant humidity oven (D63) manufactured by Yamato Kagaku Sha and thereafter, measured on the shrinkage percentage, as a result, the shrinkage percentage was 2% or less. Also, the polarizing plate was placed on a flat surface and the presence or absence of warping was observed with an eye. The warping was scarcely observed and the dimensional stability after aging was also good.

The antireflection performance such as reflectance was excellent similarly to the polarizing plate of Example 10.

The polarizing plate was cut into a size of 310x233 mm as in Fig. 2, as a result, a polarizing plate with an antireflective film, having an area efficiency of 91.5% and having an absorption axis inclined at 45° with respect to the side could be obtained. The wastes of the antireflective film and the polarizing film were as low as 8.5%. [Example 12]

Iodine-type polarizing films 94 and 94 ' prepared in Example 11 were used as two polarizing plates between which a liquid crystal cell 97 for LCD was interposed. As shown in Fig. 15, the polarizing film 94 was disposed as a polarizing plate in the display side and attached to the liquid crystal cell 97 through an adhesive to fabricate LCD. On the polarizing film 94, an antireflective film 91 was further provided.

The thus-fabricated LCD exhibited excellent brightness and view angle property, high contrast due to no reflection of external light, and good visibility with the reflected image being quenched by the antiglare performance, and even after use for one month at 40°C and 30% RH, the display grade was not deteriorated.

(Measurement of Transmittance and Polarization Degree at 550 nm)

The transmittance was measured by Shimadzu Auto- recording Spectrometer UV2100. Furthermore, from the transmittance HO (%) when the absorption axes of superposed two polarizing plates were agreed and the transmittance HI (%) when the absorption axes were orthogonalized, the polarization degree P (%) was determined by the following formula: P=[ (H0-H1) / (H0+H1) ]^1/2xl00

(Measurement of Retardation)

The measurement was performed at 632.8 nm using K0BRA21DH manufactured by 0j i Test Instruments.

[Examples 13 to 24]

Both surfaces of a PVA film were dipped in ion exchanged water for 60 seconds to wash them, and water on the surfaces was removed with a stainless steal blade to reduce the foreign matters adhering to the surfaces to 0.5% or less. This PVA film was dipped in an aqueous solution containing 1.0 g/liter of iodine and 120.0 g/liter of potassium iodide at 40°C for 65 seconds and further dipped in an aqueous solution containing 42.5 g/liter of boric acid and 30 g/liter of potassium iodide at 40°C for 90 seconds. Subsequently, the film was introduced into a tenter stretching machine in the form of Fig. 4 and stretched to 4.5 times. Then, the tenter was bent as shown in Fig. 4 with respect to the stretching direction. Thereafter, while keeping constant the width and allowing the film to shrink, the film was dried in an atmosphere of 70°C, and then removed from the tenter .

The water content percentage of the PVA film was 32% before the initiation of stretching and 4.6% after the drying. The difference in the conveyance speed between right and left tenter clips was less than 0.05% and the angle made by the center line of film introduced and the center line of film delivered to the next step was 46°. Here, |L1-L2| was 0.7 m, W was 0.7 m and a relationship of |L1-L2|=W was established. At the outlet of the tenter, the substantial stretching direction Ax-Cx was inclined at 45° with respect to the center line 22 of film delivered to next step. Wrinkling and deformation of film were not observed at the outlet of the tenter. <Preparation of Antiglare Antireflective Film>

The following coating solution for hard coat layer was coated using a bar coater on Fujitac (cellulose triacetate, retardation value: 3.0 nm) produced by Fuji

Photo Film Co., Ltd., dried at 120°C and hardened by irradiating an ultraviolet ray at an illuminance of 400 mW/cm² and a dose of 300 mJ/cm² using an air cooled metal halide lamp of 160 W/cm (manufactured by I-Graphics K.K.) to form a hard coat layer having a thickness of 4 μm.

Thereon, each of the following coating solutions (a) , (b) and (c) for antiglare or antireflective layer was coated using a bar coater and under the same conditions as above for the hard coat layer, dried and hardened with an ultraviolet ray to form an antiglare or light-scattering film having a thickness of about 1.5 μm. Further thereon, the following coating solution for low refractive index layer was coated using a bar coater, dried at 80°C and thermally crosslinked at 120°C for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm.

Thus, an antireflective film having the hard coat layer, the antiglare or light-scattering film and the low refractive index layer was produced.

(Coating Solution (a) for Antiglare or Antireflective

Layer)

In 439 g of a mixed solvent of methyl ethyl ketone/cyclohexanone (=50/50% by weight) , 125 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (trade name: DPHA, produced by Nippon Kayaku K.K.) and 125 g of bis (4- methacryloylthiophenyl) sulfide (trade name: MPSMA, produced by Sumitomo Seika Chemicals Co., Ltd.) were dissolved. To the obtained solution, a solution prepared by dissolving 5.0 g of a photopolymerization initiator (trade name: Irgacure 907, produced by Ciba Geigy) and 3.0 g of a photosensitizer (trade name: Kayacure DETX, produced by Nippon Kayaku K.K.) in 49 g of methyl ethyl ketone was added. Incidentally, the coating film obtained by coating the resulting solution and curing it with an ultraviolet ray had a refractive index of 1.60. To this solution, 10 g of crosslinked polystyrene particles (trade name: SX-200H, produced by Soken Kagaku K.K.) having an average particle size of 2 μm were further added and dispersed by stirring with a high-speed device at 5,000 rpm for 1 hour, and then the resulting dispersion was filtered through a polypropylene-made filter having a pore size of 30 μm to prepare a coating solution for antiglare or light-scattering film.

(Coating Solution (b) for Antiglare or Antireflective

Layer)

To a mixed solvent containing 104.1 g of cyclo- hexanone and 61.3 g of methyl ethyl ketone, 217.0 g of a zirconium oxide (particle size: about 30 nm) dispersion- containing hard coat coating solution (trade name: KZ- 7886A, produced by JSR Corporation) was added while stirring by an air device. Incidentally, the coating film obtained by coating this solution and curing it with an ultraviolet ray had a refractive index of 1.61. To this solution, 5 g of crosslinked polystyrene particles (trade name: SX-200H, produced by Soken Kagaku K.K.) having an average particle size of 2 μm was further added and dispersed by stirring with a high-speed device at 5,000 rpm for 1 hour, and then the resulting dispersion was filtered through a polypropylene-made filter having a pore size of 30 μm to prepare a coating solution for antiglare or light-scattering film.

(Coating Solution (c) for Antiglare or Antireflective

Layer)

To a mixed solvent containing 104.1 g of cyclo- hexanone and 61.3 g of methyl ethyl ketone, 217.0 g of a zirconium oxide (particle size: about 30 nm) dispersion- containing hard coat coating solution (trade name: KZ- 7991, produced by JSR Corporation) was added while stirring by an air device. Incidentally, the coating film obtained by coating this solution and curing it with an ultraviolet ray had a refractive index of 1.70. To this solution, 5 g of crosslinked polystyrene particles (trade name: SX-200H, produced by Soken Kagaku K.K.) having an average particle size of 2 μm was further added and dispersed by stirring with a high-speed device at 5,000 rpm for 1 hour, and then the resulting dispersion was filtered through a polypropylene-made filter having a pore size of 30 μm to prepare a coating solution for antiglare or light-scattering film.

(Coating Solution for Hard Coat Layer)

In 439 g of a mixed solvent of methyl ethyl ketone/cyclohexanone (=50/50% by weight), 250 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (trade name: DPHA, produced by Nippon Kayaku K.K.) was dissolved. To the obtained solution, a solution prepared by dissolving 7.5 g of a photopolymerization initiator (trade name:

Irgacure 907, produced by Ciba Geigy) and 5.0 g of a photosensitizer (trade name: Kayacure DETX, produced by

Nippon Kayaku K.K.) in 49 g of methyl ethyl ketone was added. Incidentally, the coating film obtained by coating the resulting solution and curing it with an ultraviolet ray had a refractive index of 1.53. Further, this solution was filtered through a polypropylene-made filter having a pore size of 30 μm to prepare a coating solution for hard coat layer. (Preparation of Coating Solution for Low Refractive Index Layer)

To 200 g of a heat-crosslinkable fluorine- containing polymer having a refractive index of 1.46 (trade name: JN-7221, produced by JSR Corporation), 200 g of methyl isobutyl ketone was added and stirred. Then, the resulting solution was filtered through a polypropylene-made filter having a pore size of 1 μm to prepare a coating solution for low refractive index layer, <Manufacture of Optical Compensating Layer>

(Formation of Orientation Film)

Fujitac (cellulose triacetate) produced by Fuji

Photo Film Co., Ltd. was fixed as a transparent support onto a coating bed, and the following coating solution containing a polyvinyl alcohol shown in Table 3 was applied onto it by a bar coater and dried under heating at 80°C for 10 minutes to form a polymer layer having a thickness of 0.8 μm (hereinafter, "parts" means "parts by weight" ) . Composition of Coating Solution:

Polyvinyl alcohol shown in Table 3 1.0 part Water 18.0 parts

Methanol 6.0 parts

The surface of the obtained polymer layer was rubbed while inclining it at 45° with respect to the longitudinal conveyance direction under the conditions such that the outer diameter of a rubbing roll was 80 mm, the glass substrate conveyance speed was 100 m/min, the rotation number of the rubbing roll was 1,000 rpm and the substrate conveyance tension was 9.8 N/cm-substrate width, thereby forming an orientation film.

(Formation of Disc-Like Liquid Crystalline Compound Layer

(Optical Anisotropic Layer) )

On the orientation film of the glass substrate after the rubbing treatment, a 10-wt% methyl ethyl ketone solution of 1, 2 , 1 ' , 2 ' , 1" , 2"-tris [4 , 5-di (vinyloxycarbonyl- ethoxybenzoyloxy) phenylene (Example Compound TP-3 described in the paragraph 0133 of Japanese Patent Laid- Open No. 152509/1997) was applied at 3,000 rpm by a spin coater and dried to form a disc-like liquid crystalline compound layer (optical anisotropic layer) .

(Evaluation of Orientation of Disc-Like Liquid Crystalline Compound Layer)

While heating the transparent support having provided thereon the orientation film and the optical anisotropic layer on a hot stage (Model FP82, manufactured by Metier) , the orientation state of the optical anisotropic layer was observed using a polarizing microscope (OPTIPHOT-POL, manufactured by Nippon Kogaku K.K.). The optical anisotropic layers obtained were bright even when viewed in a cross-Nicol state, and were revealed to exhibit optical anisotropy. The results on the observation of those optical anisotropic layers are shown in Table 3.

Table 3

Polymer compounds P-l, P-2, P-3, P-4 and polymer MP-203 for comparison used are the same polymer compounds as above-mentioned above.

While running each of the above-mentioned polarizing films and each of the antireflective films (shown in Table 4) in the longitudinal direction and laminating them using a 3% aqueous solution of PVA (PVA- 117H, produced by Kuraray Co., Ltd.) as an adhesive, a surface on the opposite side thereof and a surface on the transparent support side of the roll-form optical compensating layer obtained by superposing the optical anisotropic layer were stacked to agree the stretching direction of the polarizing film with the rubbing direction of the optical compensating layer, and bonded using an acetone-methanol (50:50) mixed solution containing 0.5% by weight of polyvinyl alcohol and 0.5% by weight of triacetyl cellulose to obtain polarizing plates with an effective width of 650 mm having the antireflective film and the optical compensating layer.

Table 4

Further, the polarizing plate was cut into a size of 310x233 mm as shown in Fig. 2. As a result, a polarizing plate having an area efficiency of 91.5% and an absorption axis inclined at 45° with respect to the side could be obtained. <Results>

The polarizing film of the present invention manufactured by the above-mentioned method could provide the polarizing plate having an absorption axis inclined at 45° with respect to the side at an area efficiency of 91.5% by the oblique stretching method showing in Fig. 4, Moreover, the polarizing plate with the antiglare or antireflective layer having a view angle enlarging function, sufficient antiglare and antireflective properties, scratch resistance and antifouling property could be obtained.

Industrial Applicability

According to the present invention, a polarizing plate which comprises an obliquely stretched polymer film obtained by subjecting a polymer ■ film to an oblique stretching method capable of improving the yield in the step of punching out a polarizing plate, has excellent smoothness, can be produced simply and easily at a low cost, particularly is favored with sufficiently high antiglare and antireflection performance, scratch resistance and antifouling property. Further, a high- performance polarizing plate having a view angle enlarging function can be provided. From this polarizing plate, a liquid crystal display having high display grade, particularly having no reduction in contrast due to reflection of external light, no entering of an outer image by reflection and no uneven color of image, and having high scratch resistance on the display surface can be provided at a low cost.

Claims

1. A long polarizing plate comprising a transparent protective film, a polarizing film and an optical compensating layer, in this order, wherein the optical compensating layer comprises a transparent support and an optical anisotropic layer, the optical anisotropic layer includes a liquid crystalline molecule, and the polarizing film has the absorption axis neither in parallel nor perpendicular to the phase lag axis of the transparent support.

2. The long polarizing plate as claimed in claim 1, wherein the optical anisotropic layer is a layer having a negative birefringent property and comprising a compound having a discotic structural unit, and the disc plane of the discotic structural unit is inclined with respect to the transparent support plane, in which the angle made by the disc plane of the discotic structural unit and the transparent support plane varies in the thickness direction of the optical anisotropic layer.

3. The long polarizing plate as claimed in claim 1, wherein the optical compensating layer has an orientation film comprising an orientating polymer between the transparent support and the optical anisotropic layer, and the orientating polymer and the liquid crystalline molecule of the optical anisotropic layer are chemically bonded through the interface of the optical anisotropic layer and the orientation film.

4. A polarizing plate comprising a transparent protective film, a polarizing film and an optical compensating layer, in this order, wherein the optical compensating layer comprises a transparent support and an optical anisotropic layer, the optical anisotropic layer includes a liquid crystalline molecule, and the angle made by the phase lag axis of the protective film and the absorption axis of the polarizing film is no less than 10° to less than 90°.

5. The polarizing plate as claimed in claim 4, wherein the optical anisotropic layer is a layer having a negative birefringent property and comprising a compound having a discotic structural unit, and the disc plane of the discotic structural unit is inclined with respect to the transparent support plane, in which the angle made by the disc plane of the discotic structural unit and the transparent support plane varies in the thickness direction of the optical anisotropic layer.

6. The polarizing plate as claimed in claim 4, wherein the optical compensating layer has an orientation film comprising an orientating polymer between the transparent support and the optical anisotropic layer, and the orientating polymer and the liquid crystalline molecule of the optical anisotropic layer are chemically bonded through the interface of the optical anisotropic layer and the orientation film.

7. The long polarizing plate as claimed in claim 1, which comprises a low refractive index layer: containing a fluorine-containing resin; and having a refractive index of 1.38 to 1.49.

8. The long polarizing plate as claimed in claim 1, which comprises an antiglare or light-scattering layer containing a binder, the binder having a refractive index of 1.57 to 2.00.

9. The long polarizing plate as claimed in claim 1, which comprises an antireflective film including a low refractive index layer and an antiglare or light- scattering layer, wherein the low refractive index layer contains a fluorine-containing resin and has a refractive index of 1.38 to 1.49, and the antiglare or light-scattering layer contains a binder having a refractive index of 1.57 to 2.00.

10. A method for producing the polarizing plate described in any one of claims 1 to 9, comprising: attaching a polarizing film or polarizing plate in a roll form to an optical compensating layer in a roll form with a roll-to-roll to integrate the polarizing film or polarizing plate with the optical compensating layer and form a roll, in which the optical compensating layer comprises a transparent support and an optical anisotropic layer containing a liquid crystalline molecule; and punching out the polarizing plate described in any one of claims 1 to 9 from the integrated roll, wherein the polarizing film in a roll form is produced by a stretching method comprising: holding both edges of a continuously fed polymer film by holding means; and stretching the film, while travelling said holding means to the longitudinal direction of the film and applying tension to the film, wherein, when Ll represents a trajectory of the holding means from a substantial holding start point until a substantial holding release point at one edge of the polymer film, L2 represents a trajectory of the holding means from a substantial holding start point until a substantial holding release point at the other edge of the polymer film, and W represent a distance between the two substantial holding release points, Ll, L2 and W satisfy a relation represented by formula (1) below, and the difference in the conveyance speed in the longitudinal direction between right and left film gripping means is less than 1%: Formula (1)

|L2-L1| > 0.4W

11. The method for producing a polarizing plate as claimed in claim 10, wherein the polymer film for the polarizing film is once stretched to 2 to 10 times while allowing 10% or more of volatile content to be present, and then shrunk by 10% or more.

12. The method for producing a polarizing plate as claimed in claim 10, wherein the polymer film is stretched while keeping the supporting property of the polymer film and while allowing a volatile content percentage of 5% or more to be present, and then reduces the volatile content percentage while being shrunk.

13. The method for producing a polarizing plate as claimed in any one of claims 10 to 12, wherein the polymer film for the polarizing film is a polyvinyl alcohol film.

14. The method for producing a polarizing plate as claimed in claim 13, wherein a polarizer is adsorbed to the polyvinyl alcohol film for the polarizing film before or after the stretching.

15. The method for producing a polarizing plate as claimed in any one of claims 10 to 14, wherein the polymer film for the polarizing film is stretched by the method described in claim 10 and then shrunk to reduce the volatile content percentage, and then a transparent protective film is attached to at least one surface of the polarizing film, and then the attached films are after-heated.

16 The method for producing a polarizing plate as claimed in any one of claims 10 to 15, wherein the polymer film for the polarizing film is stretched by the method described in claim 10 and then shrunk to reduce the volatile content percentage, and then a transparent protective film is attached to at least one surface of the polarizing film, and at the same time as the attachment or thereafter, an optical compensating layer is further attached to at least one polarizing film that the transparent protective film has been attached.

17. The method for producing a polarizing plate as claimed in any one of claims 10 to 16, wherein the film having a low refractive index layer and an antiglare or light-scattering layer is continuously attached in one surface side of the polarizing film to provide an antireflective film, in which the low refractive index layer contains a fluorine-containing resin and has a refractive index of 1.38 to 1.49, and the antiglare or light-scattering layer contains a binder, the binder having a refractive index of 1.57 to 2.00.

18. The method for producing a polarizing plate as claimed in any one of claims 10 to 16, wherein a low refractive index layer and an antiglare or light- scattering film are coated on the protective film to provide an antireflective film, in which the low refractive index layer contains a fluorine-containing resin and has a refractive index of 1.38 to 1.49, and the antiglare or light-scattering layer contains a binder, the binder having a refractive index of 1.57 to 2.00.

19. A long polarizing plate comprising: a polarizing film having a stretching axis neither in parallel nor perpendicular to the longitudinal direction; and a low refractive index layer containing a fluorine- containing resin and having a refractive index of 1.38 to 1.49.

20. A long polarizing plate comprising: a polarizing film having a stretching axis neither in parallel nor perpendicular to the longitudinal direction; and an antiglare or light-scattering layer containing a binder, the binder having a refractive index of 1.57 to 2.00.

21. A long polarizing plate comprising: a polarizing film having a stretching axis neither in parallel nor perpendicular to the longitudinal direction; and an antireflective film including a low refractive index layer and an antiglare or light-scattering layer, wherein the low refractive index layer contains a fluorine-containing resin and has a refractive index of 1.38 to 1.49, and the antiglare or light-scattering layer contains a binder having a refractive index of 1.57 to 2.00.

22 A liquid crystal display having at least one of a polarizing plate punched out from the polarizing plate described in any one of claims 1 to 3, 7 to 9 and 19 to 21, the polarizing plate described in any one of claims 4 to 6 and a polarizing plate produced by the method described in any one of claims 10 to 19.