JPWO2017104623A1 - Deformed display device - Google Patents

Abstract

  A liquid crystal display device whose display screen has a shape different from a rectangle and a square includes an IPS cell and polarizing plates that sandwich the IPS cell from both sides. The IPS cell has a pixel electrode (110) positioned in a stripe shape within the display area P of one pixel and a stripe-shaped common electrode (108) alternately arranged with the pixel electrode (110). Each polarizing plate has a thickness of 20 μm or more and 65 μm or less. Each polarizing plate has a polarizer and each optical film that sandwiches the polarizer from both sides. In each optical film of each polarizing plate, the value of Log (tan δ) between −40 ° C. and 100 ° C. is −1.8 or more.

Description

  The present invention relates to a deformed display device whose display screen has a shape different from a rectangle and a square.

  In recent years, as various electronic devices such as mobile terminals and digital signage become highly functional and diversified, in the introduction of new value to electronic devices, narrowing of the display screen has attracted attention. By promoting narrow frame technology, not only can the design of electronic devices be improved, but the shape of the display screen can be easily changed to shapes other than rectangles and squares (hereinafter also referred to as irregular shapes). can do. This is because, for example, narrowing of the frame is achieved by arranging circuits and wiring necessary for display in the display screen (not in the frame area outside the display screen). This is because signals necessary for driving the pixels can be supplied from a circuit or the like in the display screen to the end of the display screen. A display device having a display screen with an irregular shape in this way is referred to herein as an irregular display device. The application of the deformed display device is being studied particularly in a vehicle instrument panel (instrument panel) and in a field where design characteristics are desired.

  On the other hand, an IPS (In Plane Switching) liquid crystal display device is known as a display device with a wide viewing angle and high-quality display (see, for example, Patent Document 1). By making the display screen of the IPS type liquid crystal display device into a deformed shape, it is possible to realize a deformed display device with excellent visibility.

JP, 2015-114377, A (refer to claim 1, paragraph [0011], Drawing 1, etc.)

  By the way, when a deformed display device is configured by sandwiching an IPS cell between two polarizing plates from both sides, each polarizing plate is punched into a display screen shape, that is, a deformed shape. At this time, if the thickness of the polarizing plate is large, cracks are likely to be generated in the polarizing plate at the time of punching. Therefore, it is desirable that the polarizing plate is thin. That is, it is desirable to make the polarizing plate thinner from the viewpoint of improving the cutting property.

  However, when the polarizing plate is thinned, the durability of the polarizer is lowered. In other words, in in-vehicle applications such as the above-mentioned vehicle instrument panel, the interior of the vehicle may be in a high-temperature and high-humidity condition. If it is light, the color of the dyed polarizer is likely to drop, and the polarizer is deteriorated.

  In order to avoid such a decrease in the durability of the polarizer, it is necessary to deepen the staining of the polarizer. However, if the dyeing of the polarizer is increased, the transmittance of the polarizer is lowered and the brightness of the display image is lowered. For this reason, it is desired to cover the decrease in the brightness of the display image by devising the configuration of the IPS cell.

  Moreover, the polarizer (for example, polyvinyl alcohol film) of a polarizing plate has a large viscosity change due to a temperature change. For this reason, also about two optical films which pinch | interpose a polarizer, if the change of the viscosity by temperature is large, a crack may arise in a polarizing plate by a temperature change.

  The present invention was made to solve the above problems, and its purpose is to suppress the occurrence of cracks in the polarizing plate due to temperature changes and cracks when punching the polarizing plate into an irregular shape, An object of the present invention is to provide a deformed display device capable of avoiding a decrease in brightness of a display image by increasing the transmittance of an IPS cell even when the transmittance of a polarizer is decreased.

  The above object of the present invention is achieved by the following configurations.

The deformed display device according to one aspect of the present invention is a deformed display device whose display screen has a shape different from a rectangle and a square,
An IPS cell, and each polarizing plate sandwiching the IPS cell from both sides,
The IPS cell is
A pixel electrode positioned in a stripe shape within a display area of one pixel;
A stripe-shaped common electrode arranged alternately with the pixel electrode;
Each polarizing plate has a thickness of 20 μm or more and 65 μm or less,
Each polarizing plate is
It has a polarizer and each optical film that sandwiches the polarizer from both sides,
When the loss tangent indicating the ratio between the loss elastic modulus and the storage elastic modulus is tan δ,
In each optical film of each polarizing plate, the value of Log (tan δ) between −40 ° C. and 100 ° C. is −1.8 or more.

  According to the above configuration, since the polarizing plate is thin with a thickness of 20 μm or more and 65 μm or less, generation of cracks can be suppressed even when the polarizing plate is punched into an irregular shape. The IPS cell has a stripe-shaped pixel electrode and a stripe-shaped common electrode in a display area of one pixel, and these electrodes are alternately arranged. Thereby, for example, an IPS cell having a high transmittance can be realized as compared with a configuration in which a common electrode is formed in a planar shape and overlapped with a stripe-shaped pixel electrode. Therefore, even if the polarizing plate is thin and the polarization of the polarizer is increased in order to avoid a decrease in the durability of the polarizer, that is, even when the transmittance of the polarizer is reduced, an IPS cell having a high transmittance. Can be used to avoid a decrease in the brightness of the display image. Further, in each optical film of each polarizing plate, the Log (tan δ) value between −40 ° C. and 100 ° C. is −1.8 or more, and the change in viscosity due to the temperature change is small. Generation of cracks in the plate can be suppressed.

It is a top view of the liquid crystal display device which is an example of the deformed display apparatus which concerns on embodiment of this invention. FIG. 2 is a cross-sectional view taken along line A-A ′ in FIG. 1. It is sectional drawing which shows the detailed structure of the IPS cell which the said liquid crystal display device has. It is a top view which expands and shows the pixel electrode in the display area of 1 pixel of the said IPS cell. It is sectional drawing of the said pixel electrode and common electrode in the said display area. It is sectional drawing which shows the structure of the pixel electrode and common electrode in the display area of 1 pixel used as the reference example of this Embodiment. It is sectional drawing which shows the manufacturing process of the said IPS cell.

  An embodiment of the present invention will be described below with reference to the drawings. In the present specification, when the numerical range is expressed as A to B, the numerical value range includes the values of the lower limit A and the upper limit B. The present invention is not limited to the following contents.

[Liquid Crystal Display]
FIG. 1 is a plan view of a liquid crystal display device 1 which is an example of a deformed display device according to the present embodiment. The display screen 1a of the liquid crystal display device 1 has a shape (an irregular shape) other than a rectangle and a square. In FIG. 1, the shape of the display screen 1 a is a shape obtained by combining a plurality of figures, more specifically, a shape obtained by combining two convex shapes with a rectangle. Shapes such as a circle, an ellipse, a triangle, a diamond, a trapezoid, and a star are conceivable.

  FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. The liquid crystal display device 1 is configured by sandwiching an IPS cell 2 driven by the IPS system between two polarizing plates 3 and 4 and includes a backlight 5 that illuminates the IPS cell 2. The detailed configuration of the IPS cell 2 will be described later. The configuration of the present embodiment described below is applicable to all IPS liquid crystal display devices including the FFS (Fringe Field Switching) method.

  The polarizing plate 3 is located on the viewing side (the side opposite to the backlight 5) with respect to the IPS cell 2, and includes a polarizer 11, a protective film 12, and a counter film 13. The polarizer 11 transmits predetermined linearly polarized light. The protective film 12 is located on the opposite side (viewing side) from the IPS cell 2 with respect to the polarizer 11. The counter film 13 is located on the IPS cell 2 side with respect to the polarizer 11. That is, the protective film 12 and the counter film 13 are optical films that sandwich the polarizer 11 from both sides. The polarizing plate 3 is bonded to the IPS cell 2 via the adhesive layer 6 on the counter film 13 side. The polarizing plate 3 may further have functional layers such as a hard coat layer, an antiglare layer, an antireflection layer, and an antistatic layer on the side opposite to the polarizer 11 with respect to the protective film 12.

  The polarizing plate 4 is located on the backlight 5 side with respect to the IPS cell 2, and includes a polarizer 21, a protective film 22, and a counter film 23. The polarizer 21 transmits predetermined linearly polarized light, and is arranged so that the transmission axis is orthogonal to the polarizer 11. The protective film 22 is located on the opposite side (backlight 5 side) to the polarizer 21 from the IPS cell 2. The counter film 23 is located on the IPS cell 2 side with respect to the polarizer 21. That is, the protective film 22 and the counter film 23 are optical films that sandwich the polarizer 21 from both sides. The polarizing plate 4 is bonded to the IPS cell 2 via the adhesive layer 7 on the counter film 23 side.

[About IPS cells]
FIG. 3 is a cross-sectional view showing a detailed configuration of the IPS cell 2. The IPS cell 2 corresponds to a configuration in which the common electrode (counter electrode) is formed in a stripe shape in the configuration of Patent Document 1 described above. Details of the IPS cell 2 will be described below.

  The IPS cell 2 is configured by sandwiching a liquid crystal layer 300 between a TFT (Thin Film Transistor) substrate 100 and a counter substrate 200. The TFT substrate 100 and the counter substrate 200 are made of a transparent substrate such as glass or resin.

  First, the configuration on the TFT substrate 100 side will be described. A gate electrode 101 is formed on the TFT substrate 100. The gate electrode 101 is formed of the same metal layer as the scanning line. The gate electrode 101 is covered with an insulating film 102 made of silicon nitride (SiN). A semiconductor layer 103 is formed on the insulating film 102 at a position facing the gate electrode 101. The semiconductor layer 103 includes a channel portion of the TFT. A source electrode 104 and a drain electrode 105 are formed over the semiconductor layer 103 with a channel portion interposed therebetween. The source electrode 104 is connected to the video signal line, and the drain electrode 105 is connected to the pixel electrode 110. The source electrode 104 and the drain electrode 105 are formed of the same metal layer.

  The TFT includes the gate electrode 101, the semiconductor layer 103, the source electrode 104, and the drain electrode 105 described above. This TFT is covered with an inorganic passivation film 106 formed of SIN. The inorganic passivation film 106 protects the channel portion of the TFT from impurities. An organic passivation film 107 such as a polyimide resin is formed on the inorganic passivation film 106. The organic passivation film 107 is formed thick because it has the role of flattening the surface simultaneously with protecting the TFT. On the organic passivation film 107, a common electrode 108 and a passivation film 109 made of, for example, SiN or polyimide resin are formed. The common electrode 108 above the TFT is covered with a passivation film 109.

  The pixel electrode 110 is formed on the passivation film 109 and is electrically connected to the drain electrode 105 of the TFT through a through hole 111 provided in the passivation film 109. As a result, the video signal is supplied to the pixel electrode 110. The common electrode 108 and the pixel electrode 110 are made of ITO (Indium Tin Oxide), which is a material of a transparent conductive film. In addition to this, for example, an In · Sn composite oxide described in JP 2011-1000074 A May be formed. An alignment film 113 for aligning the liquid crystal molecules 301 of the liquid crystal layer 300 is formed so as to cover the pixel electrode 110.

  FIG. 4 is an enlarged plan view showing the pixel electrode 110 in the display region P of one pixel (a region not shielded by a black matrix 202 described later on the counter substrate 200). In the figure, for the sake of convenience, the common electrode 108 and the passivation film 109 are not shown. One of two directions perpendicular to each other in a plane parallel to the display screen 1a (see FIG. 1) is defined as an X direction, and the other direction is defined as a Y direction. The pixel electrode 110 electrically connected to the drain electrode 105 is branched into a plurality of areas outside the display area P of one pixel, and each extends in the X direction within the display area P. As a result, in the display region P, the pixel electrode 110 is formed in a stripe shape (stripe shape). That is, the pixel electrodes 110 extend along the X direction and are arranged side by side with an interval in the Y direction.

  FIG. 5 is a cross-sectional view of the pixel electrode 110 and the common electrode 108 in the display area P of one pixel. In FIG. 5, the alignment film 113 is not shown for convenience. As shown in the figure, in the display area P, the passivation film 109 is formed in a stripe shape in the display area P. That is, the passivation film 109 extends on the organic passivation film 107 along the X direction and is arranged side by side with an interval in the Y direction. Therefore, the organic passivation film 107 constitutes a base layer that supports each passivation film 109 from below.

  The pixel electrode 110 described above is positioned on the stripe-shaped passivation film 109. The common electrode 108 described above is formed on the organic passivation film 107 between the adjacent passivation films 109 and extending in the X direction. Therefore, the common electrode 108 extends along the X direction and is positioned so as to be alternately arranged with the pixel electrode 110 in the Y direction. That is, in the display area P, the pixel electrode 110 and the common electrode 108 do not overlap and are shifted in the Y direction.

  FIG. 6 is a cross-sectional view showing the configuration of the pixel electrode 110 and the common electrode 108 in the display area P of one pixel, which is a reference example of the present embodiment, and corresponds to the configuration of Patent Document 1. In Patent Document 1, the common electrode 108 is formed in a planar shape (solid shape) on the organic passivation film 107, the common electrode 108 is covered with the passivation film 109, and then the pixel electrode 110 is striped on the passivation film 109. Is formed. Therefore, the pixel electrode 110 overlaps with a part of the common electrode 108. Thus, the configuration of the present embodiment and the configuration of Patent Document 1 are different from each other depending on whether or not the pixel electrode 110 and the common electrode 108 overlap in the display region P.

  Next, the configuration on the counter substrate 200 side will be described. A color filter 201 of red (R), green (G), and blue (B) is formed for each pixel on the inner side (the liquid crystal layer 300 side) of the counter substrate 200 shown in FIG. A black matrix 202 is formed between the adjacent color filters 201 and 201. The black matrix 202 is a light shielding film that shields the TFT, and prevents a photocurrent from flowing through the TFT.

  An overcoat film 203 is formed so as to cover the color filter 201 and the black matrix 202. Although the surface of the color filter 201 and the black matrix 202 is uneven, the surface is flattened by providing the overcoat film 203.

  On the overcoat film 203, an alignment film 114 for determining the initial alignment of the liquid crystal is formed. Since the liquid crystal display device 1 is an IPS system, the common electrode 108 is formed on the TFT substrate 100 side as described above, and is not formed on the counter substrate 200 side.

  In the IPS cell 2, since the conductive film is not formed inside the counter substrate 200, the potential of the counter substrate 200 becomes unstable. Further, external electromagnetic noise enters the liquid crystal layer 300 and affects the image. In order to avoid such influence, a surface conductive film 210 is formed outside the counter substrate 200.

  In the configuration of the IPS cell 2 described above, a constant voltage is applied to the common electrode 108, and a voltage corresponding to the video signal is applied to the pixel electrode 110. When a voltage is applied to the pixel electrode 110, lines of electric force are generated, and the liquid crystal molecules 301 of the liquid crystal layer 300 rotate in the direction of the lines of electric force. By controlling the orientation of the liquid crystal molecules 301 in this way, the transmission of light in the liquid crystal layer 300 (the transmission of light from the backlight 5) is controlled, and an image is displayed on the display screen 1a (see FIG. 1). The

  As described above, in the present embodiment, the IPS cell 2 includes the pixel electrodes 110 located in a stripe shape within the display area P of one pixel, and the stripe-shaped common electrodes 108 arranged alternately with the pixel electrodes 110. ing. In this configuration, in the display region P, the light from the backlight 5 passes through either the pixel electrode 110 or the common electrode 108 and does not pass through both. That is, there is no overlapping portion between the pixel electrode 110 and the common electrode 108 in the display region P, and light does not pass through the overlapping portion. Accordingly, the light transmittance can be increased as compared with the configuration in FIG. 6 in which light is transmitted through the overlapping portion between the pixel electrode 110 and the common electrode 108.

  In addition, since the pixel electrode 110 and the common electrode 108 do not overlap in the display region P, it is possible to suppress the occurrence of alignment disorder of the liquid crystal molecules 301 when a voltage is applied to the pixel electrode 110 and the common electrode 108. Also by this, the transmittance of light transmitted through the liquid crystal layer 300 can be increased.

  That is, according to the configuration of the IPS cell 2 of the present embodiment, (1) there is no overlapping portion between the pixel electrode 110 and the common electrode 108 in the display region P, and light does not pass through the overlapping portion. (2) Since the alignment disorder of the liquid crystal molecules 301 can be suppressed, the IPS cell 2 having a high transmittance can be realized.

  In addition, since the pixel electrode 110 is positioned on the stripe-shaped passivation film 109 and the common electrode 108 is positioned between the adjacent passivation films 109 and 109, the pixel electrode 110 is displayed in the display area P of one pixel. A configuration in which 110 and the common electrode 108 are shifted (in the Y direction) (a configuration in which they do not overlap) can be reliably realized.

  In FIG. 3, both the inorganic passivation film 106 and the organic passivation film 107 are provided. However, either one may be omitted. In this case, the above-described base layer is one of the inorganic passivation film 106 and the organic passivation film 107. 3 illustrates a bottom gate configuration in which the semiconductor layer 103 is provided over the gate electrode 101 in the TFT substrate 100, but a top gate configuration in which the gate electrode 101 is provided over the semiconductor layer 103 is also possible. Good.

[Manufacturing method of IPS cell]
In the present embodiment, the IPS cell 2 can be manufactured by employing the same manufacturing method as in Patent Document 1 described above except that the common electrode 108 is formed in a stripe shape as described above. Therefore, in the following, a method for manufacturing the IPS cell 2 will be described by focusing on a portion different from that in Patent Document 1, that is, a portion of the display area P of one pixel.

  FIG. 7 is a cross-sectional view showing the manufacturing process of the IPS cell 2. First, a gate electrode 101 to an organic passivation film 107 are formed in a desired shape on a TFT substrate 100 (see FIG. 3) made of a transparent substrate such as glass, and then a passivation film 109 is formed on the organic passivation film 107. Subsequently, an ITO layer 110a for forming the pixel electrode 110 is solid-coated on the passivation film 109, and then a photoresist 401 is formed in a stripe shape on the ITO layer 110a.

  Next, the pixel electrode 110 made of stripe-shaped ITO is formed by wet etching the ITO layer 110a using the stripe-shaped photoresist 401 as a mask. Thereafter, the passivation layer 109 is dry-etched into a stripe shape.

  Subsequently, ITO for forming the common electrode 108 is sputtered to form an ITO layer 108a on the organic passivation film 107, and then a photoresist 402 is applied on the ITO layer 108a.

  Next, a part of the photoresist 402 is decomposed and removed by ashing, and then the ITO layer 108a on the photoresist 401 and a part of the ITO constituting the pixel electrode 110 are removed by wet etching. Finally, the photoresists 401 and 402 are decomposed and removed by an ashing process. As a result, the IPS cell 2 having the striped pixel electrode 110 and the striped common electrode 108 is obtained.

[Details of polarizing plate]
Next, the details of the polarizing plates 3 and 4 that sandwich the IPS cell 2 from both sides will be described. In addition, since the polarizer 21, the protective film 22, and the counter film 23 of the polarizing plate 4 have the same configuration as the polarizer 11, the protective film 12, and the counter film 13 of the polarizing plate 3, the polarizing plate 3 is used as an example below. Will be described in detail, and detailed description of the polarizing plate 4 will be omitted.

  The polarizer 11 is obtained, for example, by dyeing a PVA (polyvinyl alcohol) film with a dichroic dye and stretching the film at a high magnification, and the thickness thereof is 15 μm or less, preferably 5 to 7 μm.

  The protective film 12 and the counter film 13 include, for example, at least one of cellulose ester resin, cyclic polyolefin resin (COP), polyethylene terephthalate (PET) resin, and acrylic resin. The thickness of the polarizing plate 3 is 20 μm or more and 65 μm or less (the thickness of the polarizing plate 4 is the same). Thereby, since the thin polarizing plate 3 is comprised, even when the polarizing plate 3 is punched into an irregular shape in accordance with the shape of the display screen 1a (see FIG. 1), the occurrence of cracks in the polarizing plate 3 is suppressed. be able to.

  In particular, the cellulose ester resin has higher mechanical strength than COP or the like. For this reason, when the protective film 12 and the counter film 13 are comprised including a cellulose-ester-type resin, it can suppress reliably that a crack generate | occur | produces at the time of the punching of the polarizing plate 3. FIG.

  Further, since the IPS cell 2 having a high transmittance can be realized by the configuration of the IPS cell 2 described above, the polarizer 11 is dyed in order to avoid a decrease in durability of the polarizer 11 that occurs when the polarizing plate 3 is thin. Even when the value is made darker, it is possible to avoid a decrease in the brightness of the display image. That is, when the staining of the polarizer 11 is darkened, the transmittance of the polarizer 11 is reduced. However, since the high transmittance of the IPS cell 2 can be realized, even if the transmittance of the polarizer 11 is reduced, the transmittance of the IPS cell 2 is reduced. A decrease in brightness of the display image can be avoided by the high transmittance.

  In the present embodiment, when the loss tangent indicating the ratio A / B of the loss elastic modulus A and the storage elastic modulus B is tan δ, in the optical film of the polarizing plate 3 (protective film 12, counter film 13), The value of Log (tan δ) between 40 ° C. and 100 ° C. is −1.8 or more (the same applies to the optical film (protective film 22, counter film 23) of the polarizing plate 4). Note that δ corresponds to the phase delay of the strain with respect to the stress when the stress is applied to the object and the object is distorted.

  If the value of Log (tan δ) is −1.8 or more in the above temperature range, it can be said that the change in viscosity (viscoelasticity) due to the temperature change of the optical film is small. For this reason, even when a PVA film having a large change in viscosity due to a temperature change is used as the polarizer 11, the polarizer 11 is sandwiched between the protective film 12 and the counter film 13 having a small change in viscosity due to a temperature change. Generation | occurrence | production of the crack of a polarizing plate by a temperature change can be suppressed.

  Moreover, it is desirable that the optical film (protective film 12, counter film 13) of the polarizing plate 3 contains the end-capped polyester as a plasticizer (the optical film of the polarizing plate 4 (protective film 22, counter film 23)). the same). In this case, the change in phase difference and the change in viscosity due to the temperature change of the optical film can be reduced, and the optical characteristics (phase difference, viscosity) can be stabilized.

  Hereinafter, the detail of each optical film which comprises the polarizing plates 3 * 4 is demonstrated.

[Film base]
(Cellulose ester resin)
Cellulose ester-based resins that can be used as the film substrate of the optical film of the present embodiment are cellulose (di, tri) acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, and cellulose. It is preferably at least one selected from acetate phthalate and cellulose phthalate. By forming an optical film using at least one of these resins, an optical film having a Log (tan δ) value of −1.8 or more between −40 ° C. and 100 ° C. is easily realized. be able to.

  Among these, particularly preferable cellulose esters include cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate.

As the mixed fatty acid ester, more preferable cellulose acetate propionate and lower fatty acid ester of cellulose acetate butyrate have an acyl group having 2 to 4 carbon atoms as a substituent, the substitution degree of acetyl group is X, and a propionyl group Or when the substitution degree of a butyryl group is set to Y, it is preferable that it is a cellulose resin containing the cellulose ester which satisfy | fills following formula (I) and (II) simultaneously.
Formula (I) 2.6 ≦ X + Y ≦ 3.0
Formula (II) 1.0 ≦ X ≦ 2.5

  Of these, cellulose acetate propionate is particularly preferably used. Among them, 1.9 ≦ X ≦ 2.5 and 0.1 ≦ Y ≦ 0.9 are preferable. The portion not substituted with the acyl group usually exists as a hydroxyl group. These can be synthesized by known methods.

  Furthermore, as the cellulose ester used in the present embodiment, those having a ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 1.5 to 5.5 are preferably used. More preferably, a cellulose ester of 2.0 to 5.0, more preferably 2.5 to 5.0, particularly preferably 3.0 to 5.0 is used.

  The raw material cellulose of the cellulose ester used in this embodiment may be wood pulp or cotton linter. The wood pulp may be a conifer or a hardwood, but a conifer is more preferable. A cotton linter is preferably used from the viewpoint of releasability during film formation. The cellulose ester made from these can be mixed suitably or can be used independently.

  For example, the ratios of cellulose ester derived cellulose ester: wood pulp (coniferous) cellulose ester: wood pulp (hardwood) derived cellulose ester are 100: 0: 0, 90: 10: 0, 85: 15: 0, 50:50. : 0, 20: 80: 0, 10: 90: 0, 0: 100: 0, 0: 0: 100, 80:10:10, 85: 0: 15, 40:30:30 A cellulose ester can be mixed and used.

  In this embodiment, 1 g of cellulose ester-based resin is added to 20 ml of pure water (electric conductivity of 0.1 μS / cm or less, pH 6.8), and the pH when stirred in a nitrogen atmosphere at 25 ° C. for 1 hr. Is preferably 6 to 7, and the electric conductivity is preferably 1 to 100 μS / cm.

(Alicyclic olefin polymer resin)
As the film substrate of the optical film of the present embodiment, an alicyclic olefin polymer resin (COP) may be used. The alicyclic olefin polymer resin is a polymer having an alicyclic structure such as a saturated alicyclic hydrocarbon (cycloalkane) structure or an unsaturated alicyclic hydrocarbon (cycloalkene) structure. The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20, more preferably 5 to 15 in the mechanical strength, The properties of heat resistance and moldability are highly balanced and suitable.

  However, in the present embodiment, as described above, the value of Log (tan δ) between −40 ° C. and 100 ° C. is −1.8 or more from the viewpoint of suppressing the occurrence of cracks in the polarizing plate due to temperature change. It is necessary. For example, Arton (G7810) manufactured by JSR is a polymer having a polar group attached to the side chain of COP, but the minimum value of Log (tan δ) in the above temperature range is −1.7. It is suitable for the optical film. In addition, by adding rubber particles to the above arton, the value of Log (tan δ) in the above temperature range can be increased, and the change in viscosity due to the temperature change can be further reduced. As such rubber particles, for example, SRB215 manufactured by Asahi Kasei Chemicals Corporation can be used.

(Zero retardation film)
In each polarizing plate, the optical film on the IPS cell side with respect to the polarizer, that is, the counter film, from the viewpoint of improving the display performance, Ro represented by the following formula (i) is 0 nm or more and 10 nm or less, It is desirable that the Rt represented by the following formula (ii) is a zero retardation film having a value of −10 nm to +10 nm.
Formula (i) Ro = (nx−ny) × d
Formula (ii) Rt = {(nx + ny) / 2−nz} × d
(In the formula, Ro is the retardation value in the in-plane direction of the film, Rt is the retardation value in the thickness direction of the film, nx is the refractive index in the slow axis direction in the film plane, ny is the fast axis direction in the film plane) Refractive index, nz is the refractive index in the thickness direction of the film (refractive index is measured at a wavelength of 590 nm in an environment of 23 ° C. and 55% RH), and d is the thickness (nm) of the film.

  In the IPS system, since the liquid crystal cell itself is configured to exhibit good display performance, the counter film has a zero position that hardly imparts a phase difference compared to a phase difference film that imparts a phase difference to transmitted light. This is because the use of the phase difference film facilitates the advantages of liquid crystal cells (improved display performance).

  Said zero phase difference film can be implement | achieved by making a counter film contain a retardation reducing agent. Examples of the retardation reducing agent include, for example, in a compound (A) having one furanose structure or one pyranose structure, or in a compound (B) in which 2 or more and 12 or less furanose structures or pyranose structures are bonded. A sugar ester obtained by esterifying all or part of the OH group with an aliphatic acyl group can be used.

  Here, since the sugar ester as a retardation reducing agent has a furanose structure or a pyranose structure, its chemical structure is similar to that of a cellulose ester. For this reason, said sugar ester has a strong interaction with a cellulose ester. Therefore, by realizing a zero retardation film containing the above sugar ester and cellulose ester, the mechanical strength of the zero retardation film can be prevented from being lowered even if the zero retardation film is thinned.

  From the viewpoint of surely reducing the retardation Ro in the in-plane direction and the retardation Rt in the thickness direction, the sugar ester is an OH in the compound (B) in which at least one of the furanose structure or the pyranose structure is bonded to 12 or less. A compound in which all or part of the group is esterified with an aliphatic acyl group is desirable. The sugar ester is more preferably a compound obtained by esterifying all or part of the OH groups in the compound (B) in which at least one kind of furanose structure or pyranose structure is bonded to each other with an acetyl group. Examples of such sugar esters include acetyl sucrose.

[Method for producing optical film]
Next, the manufacturing method of the optical film of this embodiment is demonstrated. In the present embodiment, production methods such as a normal inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, and a hot press method can be used, but a casting method (solution casting film forming method) can be used. Alternatively, a melt casting film forming method) is preferably used.

(Solution casting film forming method)
In the solution casting film forming method, an optical film can be formed by sequentially performing the following steps.

(1) Dissolution step This step dissolves the thermoplastic resin, heat-shrinkable material, and other additives in an organic solvent mainly composed of a good solvent for the thermoplastic resin while stirring to form a dope. It is a process. For the dissolution of the thermoplastic resin, a method carried out at normal pressure, a method carried out below the boiling point of the main solvent, a method carried out under pressure above the boiling point of the main solvent, JP-A-9-95544, JP-A-9-95557 Alternatively, various dissolution methods such as a cooling dissolution method as described in JP-A-9-95538 and a high-pressure method as described in JP-A-11-21379 can be used. The method of pressurizing at a boiling point or higher is preferred.

  The dope may be mixed with a return material. The return material refers to a material obtained by finely pulverizing a film, which is generated when a film is formed, a material obtained by cutting off both side portions of the film, or a film raw material that is speculated out due to scratches or the like. By mixing the recycled material with the dope, the recycled material can be reused in the production of the film.

(2) Casting process In this process, the dope is fed to a casting die through a liquid feeding pump (for example, a pressurized metering gear pump), and then from the slit of the casting die to the casting position on the metal support. This is a step of casting the dope. As the metal support, an endless metal belt (for example, a stainless steel belt), a rotating metal drum, or the like can be used.

  As the casting die, it is preferable to use a pressure die because the slit shape of the die portion of the die can be adjusted and the film thickness can be easily made uniform. Examples of the pressure die include a coat hanger die and a T die, and any of them is preferably used.

  The surface of the metal support is a mirror surface. In order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided and stacked. Or it is also preferable to obtain the film of a laminated structure by the co-casting method which casts several dope simultaneously.

(3) Solvent evaporation step This step is a step of heating the web (a cast film (dope film) formed by casting a dope on a metal support) on the metal support to evaporate the solvent. .

  To evaporate the solvent, there are a method of blowing air from the web side and / or a method of transferring heat from the back side of the support by a liquid, a method of transferring heat from the front and back by radiant heat, and the like. High efficiency and preferable. A method of combining them is also preferably used. The web after casting is preferably dried on a metal support in an atmosphere of 40 to 100 ° C. In order to maintain the above temperature range, it is preferable to apply hot air in the above temperature range to the upper surface of the web or to heat the web by means such as infrared rays.

(4) Peeling process This process is a process of peeling the web from which the solvent has evaporated on the metal support at the peeling position. The peeled web is sent to the next process. From the viewpoint of web surface quality, moisture permeability, and peelability, it is preferable to peel the web from the metal support within 30 to 120 seconds after casting.

  The temperature (peeling temperature) at the peeling position on the metal support is preferably 10 to 40 ° C, more preferably 11 to 30 ° C.

  The residual solvent amount of the web on the metal support at the time of peeling is preferably in the range of 50 to 120% by mass depending on the strength of drying conditions, the length of the metal support, and the like. When the web is peeled off when the amount of residual solvent is larger, if the web is too soft, the flatness will be lost at the time of peeling, and slippage (linear flaws) and vertical stripes due to the peeling tension are likely to occur. The residual solvent amount at the time of peeling is determined in view of the above.

The residual solvent amount of the web is defined by the following formula.
Residual solvent amount (%) = (mass before web heat treatment (g) −mass after web heat treatment (g)) / (mass after web heat treatment (g)) × 100
Here, the heat treatment for measuring the residual solvent amount means a heat treatment at 115 ° C. for 1 hour.

  The peeling tension at the time of peeling the web from the metal support is usually 196 to 245 N / m. However, when wrinkles are easily generated at the time of peeling, it is preferable to peel at a tension of 190 N / m or less. It is preferable that peeling is performed at a minimum tension that can be peeled to 166.6 N / m and then at a minimum tension of 137.2 N / m. Particularly preferably, peeling is performed at a minimum tension of 100 N / m.

  In this embodiment, the temperature at the peeling position on the metal support is preferably −50 to 40 ° C., more preferably 10 to 40 ° C., and most preferably 15 to 30 ° C.

(5) Drying and stretching step This step is a step of peeling the web from the metal support and then drying the peeled web in a drying device and / or stretching using a tenter stretching device. In the drying apparatus, a plurality of rolls are arranged, and the web is dried by conveying the web through each roll alternately. In the tenter stretching apparatus, both ends of the web are clipped and conveyed by a clip, and the web is stretched.

  As a means for drying the web in the drying apparatus, hot air is generally blown on both sides of the web, but there is also a means for heating by applying microwaves instead of the wind. Too rapid drying tends to impair the flatness of the finished film. Drying at a high temperature is preferably performed from a residual solvent amount of about 8% by mass or less. Throughout the drying is generally carried out at 40-250 ° C. It is particularly preferable to dry at 40 to 160 ° C.

  When using a tenter stretching apparatus, it is preferable to use an apparatus capable of independently controlling the film gripping length (distance from the start of gripping to the end of gripping) left and right by the left and right gripping means of the tenter. In the stretching step, it is also preferable to intentionally create zones (zones) having different temperatures in order to improve planarity.

  It is also preferable to provide a neutral zone between different temperature zones so that the zones do not interfere with each other.

In addition, extending | stretching operation may be divided | segmented and implemented in multiple steps, and it is also preferable to implement biaxial stretching (stretching of a casting direction and a width direction). Moreover, when performing biaxial stretching, simultaneous biaxial stretching may be performed and you may implement in steps. The stepwise stretching may be, for example, sequentially performing stretching in different stretching directions, or dividing stretching in the same direction into multiple stages and adding stretching in different directions to any of the stages. It may be. That is, for example, the following stretching steps are possible.
-Stretch in the casting direction-Stretch in the width direction-Stretch in the casting direction-Stretch in the casting direction-Stretch in the width direction-Stretch in the width direction-Stretch in the casting direction-Stretch in the casting direction

  Simultaneous biaxial stretching includes stretching in one direction and contracting the other while relaxing the tension. The preferable draw ratio of simultaneous biaxial stretching can be set in the range of 1.01 to 1.5 times in both the width direction and the longitudinal direction.

  When the stretching is performed, the residual solvent amount of the web is preferably 20 to 100% by mass at the start of stretching, and is stretched until the residual solvent amount of the web is 10% by mass or less (more preferably 5% by mass or less). It is preferable to perform drying while applying.

  30-160 degreeC is preferable, as for the drying temperature in the case of extending | stretching, 50-150 degreeC is more preferable, and 70-140 degreeC is the most preferable.

  In the stretching step, it is preferable that the temperature distribution in the width direction of the atmosphere is less uneven from the viewpoint of improving the uniformity of the film. Specifically, the temperature unevenness in the width direction in the stretching step is preferably within ± 5 ° C., more preferably within ± 2 ° C., and most preferably within ± 1 ° C.

(6) Winding step This step is a step of winding the film as a film by a winder after the residual solvent amount in the web is 2% by mass or less. By setting the residual solvent amount to 0.4% by mass or less, a film having good dimensional stability can be obtained. In particular, the film is preferably wound at 0.00 to 0.10% by mass.

  As a winding method, a generally used method may be used, and there are a constant torque method, a constant tension method, a taper tension method, a program tension control method with a constant internal stress, and the like.

  The optical film in the present embodiment is preferably a long film. Specifically, the optical film has a thickness of about 100 m to 5000 m and is usually provided in a roll shape. Moreover, it is preferable that the width | variety of a film is 1.3-4m, and it is more preferable that it is 1.4-2m.

(Melt casting method)
In the melt casting film forming method, an optical film can be formed by sequentially performing the following steps.

<Melted pellet manufacturing process>
The composition containing a resin used for melt extrusion is usually preferably kneaded in advance and pelletized.

  Pelletization may be performed by a known method. For example, an additive comprising a dried thermoplastic resin and a heat-shrinkable material is supplied to an extruder with a feeder and kneaded using a single-screw or twin-screw extruder. It is possible to extrude into a strand form from a die, and then perform water cooling or air cooling and cutting.

  It is important to dry the raw material before extruding to prevent decomposition of the raw material. In particular, since the cellulose ester easily absorbs moisture, it is preferable to dry it at 70 to 140 ° C. for 3 hours or more with a dehumidifying hot air dryer or a vacuum dryer to keep the moisture content at 200 ppm or less, and further 100 ppm or less.

  The additives may be mixed before being supplied to the extruder, or may be supplied by individual feeders. A small amount of additives such as particles and antioxidants are preferably mixed in advance in order to mix uniformly.

  The antioxidant may be mixed with each other, and if necessary, the antioxidant may be dissolved in a solvent, impregnated with a thermoplastic resin and mixed, or mixed by spraying. May be.

It is preferable to use a vacuum nauter mixer because drying and mixing can be performed simultaneously. The portion exposed to the air, such as the exit from the feeder unit or die, it is preferable that the atmosphere such as dehumidified air and dehumidified N ₂ gas.

  The extruder is preferably processed at a temperature as low as possible so that it can be pelletized so that the shearing force is suppressed and the resin does not deteriorate (molecular weight reduction, coloring, gel formation, etc.). For example, in the case of a twin screw extruder, it is preferable to rotate in the same direction using a deep groove type screw. From the uniformity of kneading, the meshing type is preferable.

  A film is formed using the pellets obtained as described above. It is also possible to feed the raw material powder directly to the extruder with a feeder and form a film as it is without pelletization.

<Process for extruding molten mixture from die to cooling roll>
First, using a single-screw or twin-screw type extruder, the melt temperature Tm when extruding the pellets is about 200 to 300 ° C., and filtered through a leaf disk type filter to remove foreign matters. The film is extruded from a die into a film, solidified on a cooling roll, and cast while being pressed with an elastic touch roll.

  When introducing into the extruder from the supply hopper, it is preferable to prevent oxidative decomposition or the like under vacuum or reduced pressure or in an inert gas atmosphere. Tm is the temperature of the die exit portion of the extruder.

  If foreign matter such as scratches or plasticizer aggregates adheres to the die, streak-like defects may occur. Such a defect is also called a die line. In order to reduce surface defects such as die lines, it is preferable that the piping from the extruder to the die has a structure in which the resin retention portion is minimized. It is preferable to use a die that has as few scratches as possible inside the lip.

  The inner surface that contacts the molten resin such as an extruder or a die is preferably subjected to surface treatment that makes it difficult for the molten resin to adhere to the surface by reducing the surface roughness or using a material having a low surface energy. Specifically, a hard chrome plated or ceramic sprayed material is polished so that the surface roughness is 0.2 S or less.

  Although there is no restriction | limiting in particular in a cooling roll, What is necessary is just a roll provided with the structure where the heat medium which can control temperature inside, or a refrigerant body flows with a highly rigid metal roll. Further, the size of the cooling roll is not limited, but may be a size sufficient to cool the melt-extruded film. Usually, the diameter of the cooling roll is about 100 mm to 1 m.

  Examples of the surface material of the cooling roll include carbon steel, stainless steel, aluminum, and titanium. Further, in order to increase the hardness of the surface or improve the releasability from the resin, it is preferable to perform a surface treatment such as hard chrome plating, nickel plating, amorphous chrome plating, or ceramic spraying.

  The surface roughness of the chill roll surface is preferably 0.1 μm or less in terms of Ra, and more preferably 0.05 μm or less. The smoother the roll surface, the smoother the surface of the resulting film. Of course, the surface processed surface may be further polished to further reduce the surface roughness.

  Examples of the elastic touch roll include JP 03-124425, JP 08-224772, JP 07-1000096, JP 10-272676, WO 97/028950, JP 11-235747, JP 2002-2002. A thin-film metal sleeve-covered silicon rubber roll as described in Japanese Patent No. 36332, Japanese Patent Application Laid-Open No. 2005-172940, or Japanese Patent Application Laid-Open No. 2005-280217 can be used.

  When peeling the film from the cooling roll, it is preferable to control the tension to prevent deformation of the film.

[Production method of composite resin film]
The optical film of this embodiment may be composed of a composite resin film. As a method for producing the composite resin film, a co-flow method or a co-extrusion method can be employed.

(Co-flow method: double cast method)
The metal support in the casting (casting) step preferably has a mirror-finished surface. As the metal support, a stainless steel belt or a drum whose surface is plated with a casting is preferably used. The cast width can be 1 to 4 m.

  The surface temperature of the metal support in the casting step is set to −50 ° C. to a temperature at which the solvent boils and does not foam. A higher temperature is preferable because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate. As preferable support body temperature, it determines suitably at 0-100 degreeC, and 5-30 degreeC is still more preferable. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent.

  The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. . In particular, it is preferable to perform drying efficiently by changing the temperature of the support and the temperature of the drying air during the period from casting to peeling.

  In this embodiment, it is also preferable to cast the acetylated cellulose solution by dividing it into two or more times.

  The prepared dope A is cast on a stainless steel belt by a die, and the further prepared dope B is laminated and cast on the cast web through the die. The laminated web is peeled at the peeling point, and then dried and wound up in a drying zone.

  There is no restriction | limiting in particular in the structure as a composition of dope A and dope B, The composition ratio of acetylated cellulose, a cellulose nanofiber, and another additive and a solvent can be taken in any way. Further, the cast film thickness of the dope A and dope B is not particularly limited. Three or more split casts are possible.

(Co-extrusion method)
In the present embodiment, a film having a laminated structure can also be produced by a coextrusion method. For example, a film having a structure of skin layer / core layer / skin layer can be produced. For example, the matting agent can be contained in the skin layer in a large amount or only in the skin layer. The plasticizer and the ultraviolet absorber can be contained in the core layer more than the skin layer, and may be contained only in the core layer. In addition, the type of plasticizer and ultraviolet absorber can be changed between the core layer and the skin layer. For example, the skin layer contains a low-volatile plasticizer and / or an ultraviolet absorber, and the core layer has excellent plasticity. It is also possible to add a plasticizer or an ultraviolet absorber excellent in ultraviolet absorption. The glass transition temperature of the skin layer and the core layer may be different, and the glass transition temperature of the core layer is preferably lower than the glass transition temperature of the skin layer. At this time, the glass transition temperatures of both the skin and the core can be measured, and an average value calculated from these volume fractions can be defined as the glass transition temperature Tg and similarly handled. Also, the viscosity of the melt containing the cellulose ester during melt casting may be different between the skin layer and the core layer, and the viscosity of the skin layer> the viscosity of the core layer or the viscosity of the core layer ≧ the viscosity of the skin layer may be used.

  The above-mentioned co-extrusion method uses a plurality of extruders to heat and melt the resin to be laminated from each other, and after the respective resins are merged, co-extrusion is performed from the slit-shaped discharge port of the T die. Is a method of forming a cast sheet (unstretched state) by cooling and solidifying. As a method of joining the molten resin and extruding the sheet from the T-die, a feed block method in which the molten resin is joined and then the manifold is widened, and a multi-manifold method in which the molten resin is spread by the manifold and then joined together. Either of them can be used.

〔Additive〕
The optical film (film substrate) of this embodiment preferably contains an antioxidant. Preferred antioxidants are phosphorous or phenolic, and it is more preferred to combine phosphorous and phenolic simultaneously. Hereinafter, the antioxidant that can be suitably used in the present embodiment will be described.

<Phenolic antioxidant>
In this embodiment, a phenolic antioxidant is preferably used, and a hindered phenol compound is particularly preferably used.

Specific examples of hindered phenol compounds include n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, n-octadecyl 3- (3,5-di-t-butyl- 4-hydroxyphenyl) -acetate, n-octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, n-hexyl 3,5-di-tert-butyl-4-hydroxyphenylbenzoate, n-dodecyl 3, 5-di-t-butyl-4-hydroxyphenylbenzoate, neo-dodecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, dodecyl β (3,5-di-t-butyl- 4-hydroxyphenyl) propionate, ethyl α- (4-hydroxy-3,5-di-t-butylphenyl) isobutyrate, octade Sil α- (4-hydroxy-3,5-di-t-butylphenyl) isobutyrate, octadecyl α- (4-hydroxy-3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2- (n -Octylthio) ethyl 3,5-di-t-butyl-4-hydroxy-benzoate, 2- (n-octylthio) ethyl 3,5-di-t-butyl-4-hydroxy-phenylacetate, 2- (n- Octadecylthio) ethyl 3,5-di-t-butyl-4-hydroxyphenyl acetate, 2- (n-octadecylthio) ethyl 3,5-di-t-butyl-4-hydroxy-benzoate, 2- (2- Hydroxyethylthio) ethyl 3,5-di-t-butyl-4-hydroxybenzoate, diethyl glycol bis- (3,5-di-t-butyl-4) -Hydroxy-phenyl) propionate, 2- (n-octadecylthio) ethyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, stearamide-N, N-bis- [ethylene 3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate], n-butylimino-N, N-bis- [ethylene 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2- (2-stearoyloxyethylthio) ethyl 3,5-di-tert-butyl-4-hydroxybenzoate, 2- (2-stearoyloxyethylthio) ethyl 7- (3-methyl-5-tert-butyl- 4-hydroxyphenyl) heptanoate, 1,2-propylene glycol bis- [3- (3,5-di-tert-butyl-4-hydroxy) Phenyl) propionate], ethylene glycol bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], neopentyl glycol bis- [3- (3,5-di-t-butyl-) 4-hydroxyphenyl) propionate], ethylene glycol bis- (3,5-di-t-butyl-4-hydroxyphenyl acetate), glycerin-1-n-octadecanoate-2,3-bis- (3 5-di-t-butyl-4-hydroxyphenyl acetate), pentaerythritol-tetrakis- [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate], 1,1,1 -Trimethylolethane-tris- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], sol Tall hexa- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2-hydroxyethyl 7- (3-methyl-5-tert-butyl-4-hydroxyphenyl) propionate, 2- Stearoyloxyethyl 7- (3-methyl-5-t-butyl-4-hydroxyphenyl) heptanoate, 1,6-n-hexanediol-bis [(3 ', 5'-di-t-butyl-4-hydroxy Phenyl) propionate], pentaerythritol-tetrakis (3,5-di-t-butyl-4-hydroxyhydrocinnamate). Hindered phenol compounds of the above type are commercially available from Ciba Japan, for example, under the trade names “Irganox 1076” and “Irganox 1010”.

<Phosphorus antioxidant>
As the phosphorus antioxidant, phosphorus compounds such as phosphite, phosphonite, phosphinite, or tertiary phosphane can be used. A conventionally known compound can be used as the phosphorus compound. For example, Japanese Patent Application Laid-Open Nos. 2002-138188, 2005-344444, paragraph numbers 0022 to 0027, Japanese Patent Application Laid-Open No. 2004-18279, paragraph numbers 0023 to 0039, Japanese Patent Application Laid-Open No. 10-306175, Japanese Patent Application Laid-Open No. 1-254744, and Japanese Patent Application Laid-Open No. -270892, JP-A-5-202078, JP-A-5-178870, JP-T-2004-504435, JP-T-2004-530759, and JP-A-2005-353229 Is preferred.

  The addition amount of a phosphorus compound is 0.01-10 mass parts normally with respect to 100 mass parts of resin, Preferably it is 0.05-5 mass parts, More preferably, it is 0.1-3 mass parts.

  As phosphorus compounds, in addition to the compounds represented by the above general formula, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite Tris (2,4-di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphat Phenanthrene-10-oxide, 6- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-t-butyldibenz [d, f] [1 3.2] Monophosphite compounds such as dioxaphosphine and tridecyl phosphite; 4,4'-butylidene-bi Diphosphite compounds such as (3-methyl-6-t-butylphenyl-di-tridecyl phosphite), 4,4'-isopropylidene-bis (phenyl-di-alkyl (C12-C15) phosphite); Phenylphosphonite, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite, tetrakis (2,4-di-tert-butyl-5-methyl) Phosphonite compounds such as phenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite; Phosphinite compounds such as triphenylphosphinite and 2,6-dimethylphenyldiphenylphosphinite; Triphenylphosphine Phosphine compounds such as tris (2,6-dimethoxyphenyl) phosphine; It is below.

  Phosphorus compounds of the above type are, for example, from Sumitomo Chemical Co., Ltd. “Sumilizer GP”, from ADEKA Co., Ltd. “ADK STAB PEP-24G”, “ADK STAB PEP-36” and “ADK STAB 3010”, Ciba Japan Co., Ltd. It is commercially available under the trade name “IRGAFOS P-EPQ” from the company and “GSY-P101” from Sakai Chemical Industry Co., Ltd.

<Other antioxidants>
Dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythrityltetrakis (3-laurylthiopropioate) Nate) and the like, 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy) -3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate and the like, heat-resistant processing stabilizers such as 3,4-dihydro-2H-1 described in JP-B-08-27508 -Benzopyran compounds, 3,3'-spirodichroman compounds, 1,1-spiroindane compounds, morpholine, thiomorpho Emissions, thiomorpholine oxide, thiomorpholine dioxide, a compound having a piperazine skeleton partial structure, oxygen scavenger dialkoxy benzene type compound in JP-03-174150 describes the like. These antioxidant partial structures may be part of the polymer or regularly pendant into the polymer and introduced into part of the molecular structure of additives such as plasticizers, acid scavengers, and UV absorbers. It may be.

(Other additives)
In addition to the above-described compounds, the film substrate according to the present embodiment can contain various compounds as additives depending on the purpose.

<Acid scavenger>
The acid scavenger preferably comprises an epoxy compound as an acid scavenger described in US Pat. No. 4,137,201. Epoxy compounds as such acid scavengers are known in the art and are derived by condensation of diglycidyl ethers of various polyglycols, particularly about 8-40 moles of ethylene oxide per mole of polyglycol. Metal glycol compounds such as polyglycols, diglycidyl ethers of glycerol (eg, those conventionally used in and together with vinyl chloride polymer compositions), epoxidized ether condensation products, bisphenol A Diglycidyl ether (ie, 4,4'-dihydroxydiphenyldimethylmethane), epoxidized unsaturated fatty acid ester (especially an ester of an alkyl of about 2 to 2 carbon atoms of a fatty acid of 2 to 22 carbon atoms (e.g. Butyl epoxy stealey ), And various epoxidized long chain fatty acid triglycerides, etc. (eg, epoxidized vegetable oils and other unsaturated natural oils, which are sometimes epoxidized, which can be represented and exemplified by compositions such as epoxidized soybean oil) These are referred to as natural glycerides or unsaturated fatty acids, which generally contain 12 to 22 carbon atoms)).

<Light stabilizer>
Light stabilizers include hindered amine light stabilizer (HALS) compounds, which are known compounds, such as columns 5-11 of US Pat. No. 4,619,956 and US Pat. , 839,405, as described in columns 3 to 5, including 2,2,6,6-tetraalkylpiperidine compounds, or acid addition salts thereof or complexes of them with metal compounds It is. Furthermore, the light stabilizer described in JP 2007-63311 A can be used.

<Ultraviolet absorber>
As the ultraviolet absorber, from the viewpoint of preventing deterioration due to ultraviolet rays, those having excellent absorption ability of ultraviolet rays having a wavelength of 370 nm or less and those having little absorption of visible light having a wavelength of 400 nm or more are preferable from the viewpoint of liquid crystal display properties. Examples include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, etc., but benzophenone compounds and less colored benzotriazole compounds preferable. Moreover, you may use the ultraviolet absorber of Unexamined-Japanese-Patent No. 10-182621, Unexamined-Japanese-Patent No. 8-337574, and the polymeric ultraviolet absorber of Unexamined-Japanese-Patent No. 6-148430.

  Specific examples of the benzotriazole-based compound include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzo Triazole, 2- (2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1 , 1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2'-hydroxy-3'- ert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5 '-(2-octyloxycarbonylethyl) -phenyl) -5-chloro Benzotriazole, 2- (2′-hydroxy-3 ′-(1-methyl-1-phenylethyl) -5 ′-(1,1,3,3-tetramethylbutyl) -phenyl) benzotriazole, 2- ( 2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazole) 2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzene) Zotoriazoru 2-yl) can be mentioned mixtures of phenyl] propionate, but not limited thereto.

  Moreover, as a commercial item, TINUVIN 326, TINUVIN 109, TINUVIN 171, TINUVIN 900, TINUVIN 928, TINUVIN 928, TINUVIN 360 (all manufactured by Ciba Japan) LA31 (manufactured by ADEKA), Sumisorb 250 (manufactured by Sumitomo Chemical), and RUVA-100 (manufactured by Otsuka Chemical).

  Specific examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis (2-methoxy-4-hydroxy- 5-benzoylphenylmethane) and the like, but are not limited thereto.

  In the present embodiment, the ultraviolet absorber is preferably added in an amount of 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and further preferably 1 to 5% by mass. Two or more of these may be used in combination.

<Matting agent>
Fine particles such as a matting agent can be added to the film substrate of the present embodiment, and examples of the fine particles include inorganic compound fine particles and organic compound fine particles. Examples of the fine particles include inorganic fine particles such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate. Crosslinked polymer fine particles can be mentioned. Among these, silicon dioxide is preferable because it can reduce the haze of the resin substrate. In many cases, fine particles such as silicon dioxide are surface-treated with an organic material, but such particles are preferable because they can reduce the haze of the resin substrate.

  Preferred organic substances for the surface treatment include halosilanes, alkoxysilanes, silazane, siloxane and the like. The larger the average particle size of the fine particles, the greater the sliding effect, and the smaller the average particle size, the better the transparency.

  Moreover, the average particle diameter of the secondary particles of the fine particles is in the range of 0.05 to 1.0 μm. The average particle size of secondary particles of the fine particles is preferably 5 to 50 nm, more preferably 7 to 14 nm. These fine particles are preferably used in the cellulose ester film in order to produce irregularities of 0.01 to 1.0 μm on the surface of the cellulose ester film. The content of fine particles in the cellulose ester is preferably 0.005 to 0.3% by mass with respect to the cellulose ester.

  Examples of the fine particles of silicon dioxide include Aerosil 200, 200V, 300, R972, R972V, R974, R202, R812, OX50, TT600 manufactured by Nippon Aerosil Co., Ltd., preferably Aerosil 200V, R972. , R972V, R974, R202, R812. Two or more kinds of these fine particles may be used in combination. When using 2 or more types together, it can mix and use in arbitrary ratios. In this case, fine particles having different average particle sizes and materials, for example, Aerosil 200V and R972V can be used in a mass ratio of 0.1: 99.9 to 99.9: 0.1.

  The presence of fine particles in the base material used as the matting agent can be used for another purpose to improve the strength of the base material.

(Plasticizer)
The optical film preferably contains a plasticizer. As the plasticizer, a polyester compound is preferable.

  Although it does not specifically limit as a polyester compound, For example, the polymer (henceforth "polyester polyol") obtained by the condensation reaction of dicarboxylic acid or these ester-forming derivatives, and glycol, and a terminal becomes a hydroxyl group (hydroxyl group). Alternatively, a polymer in which the terminal hydroxyl group of the polyester polyol is sealed with a monocarboxylic acid (hereinafter, also referred to as “end-capped polyester” or simply “end-capped polyester”) can be used. In the present specification, the ester-forming derivative is an esterified product of dicarboxylic acid, dicarboxylic acid chloride, or anhydride of dicarboxylic acid.

  Since the optical film of this embodiment contains the end-capped polyester as a plasticizer, fluctuations in retardation and viscosity (tan δ) due to temperature changes of the film are suppressed, and optical characteristics (retardation and viscosity) are stable. To do.

  Specific examples of the polyester compound include ester compounds represented by the following general formula (A).

B- (GA) n-GB ... (A)
(In the formula, B is a hydroxy group, a benzene monocarboxylic acid residue or an aliphatic monocarboxylic acid residue, and G is an alkylene glycol residue having 2 to 18 carbon atoms or an aryl glycol residue having 6 to 12 carbon atoms, or An oxyalkylene glycol residue having 4 to 12 carbon atoms, A is an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 16 carbon atoms, and n is an integer of 1 or more. is there.)

  In the general formula (A), a compound in which B is a hydroxy group corresponds to a polyester polyol, and a compound in which B is a benzene monocarboxylic acid residue or an aliphatic monocarboxylic acid residue corresponds to an end-capped polyester. The polyester compound represented by the general formula (A) is obtained by the same reaction as a normal polyester plasticizer.

  As the aliphatic monocarboxylic acid component of the polyester compound represented by the general formula (A), for example, an aliphatic monocarboxylic acid having 3 or less carbon atoms is preferable, and examples include acetic acid, propionic acid, and butanoic acid (butyric acid). Each of these can be used as one kind or a mixture of two or more kinds.

  Examples of the benzene monocarboxylic acid component of the polyester compound represented by the general formula (A) include benzoic acid, para-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, normal There are propylbenzoic acid, aminobenzoic acid, acetoxybenzoic acid, aliphatic acid and the like, and these can be used as one kind or a mixture of two or more kinds, respectively. In particular, it is preferable to contain benzoic acid or p-toluic acid.

  Examples of the alkylene glycol component having 2 to 18 carbon atoms of the polyester compound represented by the general formula (A) include ethylene glycol, 1,2-propanediol (1,2-propylene glycol), 1,3-propanediol (1 , 3-propylene glycol), 1,2-butanediol, 1,3-butanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2,3-butane Diol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 1,2-cyclopentanediol, 1,3-cyclopentanediol, 1,4-cyclohexanediol, 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-buty 2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl-1,5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol , 2-ethyl 1,3-hexanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, and the like. It is used as one kind or a mixture of two or more kinds. Among these, ethylene glycol, diethylene glycol, 1,2-propylene glycol, and 2-methyl 1,3-propanediol are preferable, and ethylene glycol, diethylene glycol, and 1,2-propylene glycol are more preferable. In particular, an alkylene glycol having 2 to 12 carbon atoms is preferable because of excellent compatibility with a cellulose ester. More preferably, it is C2-C6 alkylene glycol, More preferably, it is C2-C4 alkylene glycol.

  Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the polyester compound represented by the general formula (A) include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. Glycols can be used as one or a mixture of two or more.

  Examples of the aryl glycol having 6 to 12 carbon atoms of the polyester compound represented by the general formula (A) include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, cyclohexanediethanol, and 1,4-benzenedimethanol. And these glycols can be used as one kind or a mixture of two or more kinds.

  Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the polyester compound represented by the general formula (A) include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. There are acids and the like, and these are used as one kind or a mixture of two or more kinds, respectively.

  Examples of the aryl dicarboxylic acid component having 6 to 16 carbon atoms of the polyester compound represented by the general formula (A) include phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, There are 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,6-anthracenedicarboxylic acid and the like. The aryl dicarboxylic acid may have a substituent on the aromatic ring. Examples of the substituent include a linear or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group, and an aryl group having 6 to 12 carbon atoms.

  In the general formula (A), when B is a hydroxy group, that is, when the polyester compound is a polyester polyol, A is preferably an aryl dicarboxylic acid residue having 10 to 16 carbon atoms. For example, a dicarboxylic acid having an aromatic cyclic structure such as a benzene ring structure, a naphthalene ring structure, or an anthracene ring structure can be used. Specific examples of the aryl dicarboxylic acid component include orthophthalic acid, isophthalic acid, terephthalic acid, Mentioning 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,6-anthracenedicarboxylic acid Can do. Preferred are 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, and more preferred is 2 , 3-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid, particularly preferably 2,6-naphthalenedicarboxylic acid. These can be used alone or in combination of two or more.

  The polyester polyol preferably has a carbon number average of 10 to 16 in the dicarboxylic acid used as a raw material. If the carbon number average of the dicarboxylic acid is 10 or more, the dimensional stability of the cellulose ester film is excellent. If the carbon number average is 16 or less, the compatibility with the cellulose ester is excellent, and the transparency of the cellulose ester film. Is remarkably superior. As dicarboxylic acid, Preferably the average of carbon number is 10-14, More preferably, the average of carbon number is 10-12.

  The average carbon number of the dicarboxylic acid of the polyester polyol means the carbon number of the dicarboxylic acid when the polyester polyol is polymerized using a single dicarboxylic acid, but the polyester using two or more kinds of dicarboxylic acids. When polymerizing a polyol, it means the sum of the products of the carbon number of each dicarboxylic acid and the molar fraction of the dicarboxylic acid.

  If the average number of carbon atoms is 10 to 16, the above-mentioned aryl dicarboxylic acid having 10 to 16 carbon atoms and other dicarboxylic acids can be used in combination. The dicarboxylic acid that can be used in combination is preferably a dicarboxylic acid having 4 to 9 carbon atoms. For example, succinic acid, glutaric acid, adipic acid, maleic acid, orthophthalic acid, isophthalic acid, terephthalic acid, esterified products thereof, and acid A chloride and an acid anhydride can be mentioned.

Although the specific example of the dicarboxylic acid whose carbon number of polyester polyol is 10-16 below is shown, in this embodiment, it is not limited to these at all.
(1) 2,6-naphthalenedicarboxylic acid (2) 2,3-naphthalenedicarboxylic acid (3) 2,6-anthracenedicarboxylic acid (4) 2,6-naphthalenedicarboxylic acid: succinic acid (75: 25-99: 1 molar ratio)
(5) 2,6-naphthalenedicarboxylic acid: terephthalic acid (50:50 to 99: 1 molar ratio)
(6) 2,3-naphthalenedicarboxylic acid: succinic acid (75:25 to 99: 1 molar ratio)
(7) 2,3-naphthalenedicarboxylic acid: terephthalic acid (50:50 to 99: 1 molar ratio)
(8) 2,6-anthracene dicarboxylic acid: succinic acid (50:50 to 99: 1 molar ratio)
(9) 2,6-anthracene dicarboxylic acid: terephthalic acid (25:75 to 99: 1 molar ratio)
(10) 2,6-naphthalenedicarboxylic acid: adipic acid (67:33 to 99: 1 molar ratio)
(11) 2,3-naphthalenedicarboxylic acid: adipic acid (67:33 to 99: 1 molar ratio)
(12) 2,6-anthracene dicarboxylic acid: adipic acid (40:60 to 99: 1 molar ratio)

  As the polyester compound that can be used in the present embodiment, in addition to the above-described polyester polyol, a compound having an octanol-water partition coefficient (logP (B)) of 0 or more and less than 7 from the viewpoint of water solubility and orientation of the compound. It is also preferable to use it.

  The polyester polyol is a dicarboxylic acid or an ester-forming derivative thereof (a component corresponding to A in the general formula (A)) and a glycol (a component corresponding to G in the general formula (A)). In the presence, for example, it can be produced by an esterification reaction within a temperature range of 180 to 250 ° C. for 10 to 25 hours by a well-known and conventional method.

  In performing the esterification reaction, a solvent such as toluene or xylene may be used, but a method using no solvent or glycol used as a raw material as a solvent is preferable.

  As the esterification catalyst, for example, tetraisopropyl titanate, tetrabutyl titanate, p-toluenesulfonic acid, dibutyltin oxide and the like can be used. The esterification catalyst is preferably used in an amount of 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the total amount of dicarboxylic acids or their ester-forming derivatives.

  The molar ratio when the dicarboxylic acid or their ester-forming derivative is reacted with the glycol must be a molar ratio in which the terminal group of the polyester becomes a hydroxy group (hydroxyl group). Therefore, the dicarboxylic acid or their ester-forming derivative The glycol is 1.1 to 10 moles per mole. Preferably, the glycol is 1.5 to 7 moles per mole of the dicarboxylic acid or their ester-forming derivative, more preferably the glycol is one mole of the dicarboxylic acid or their ester-forming derivative. 2 to 5 moles.

  The terminal group of the polyester polyol is a hydroxy group (hydroxyl group), but the polyester polyol may contain a carboxy group-terminated compound as a by-product. However, the carboxy group terminal in the polyester polyol lowers the humidity stability, so that the content is preferably low. Specifically, the acid value is preferably 5.0 mgKOH / g or less, more preferably 1.0 mgKOH / g or less, and still more preferably 0.5 mgKOH / g or less. Here, the “acid value” refers to the number of milligrams of potassium hydroxide necessary to neutralize the acid (carboxy group present in the sample) contained in 1 g of the sample. The acid value can be measured according to JIS K0070: 1992.

  The polyester polyol preferably has a hydroxy (hydroxyl group) value (OHV) in the range of 35 mg / g to 220 mg / g. The hydroxy (hydroxyl group) value here means the number of milligrams of potassium hydroxide required to neutralize acetic acid bonded to a hydroxy group (hydroxyl group) when OH group contained in 1 g of a sample is acetylated. . The hydroxy (hydroxyl group) value is obtained by acetylating OH groups in a sample with acetic anhydride, titrating acetic acid that has not been used with a potassium hydroxide solution, and determining the difference from the initial titration value of acetic anhydride.

  The polyester polyol preferably has a hydroxy group (hydroxyl group) content of 70% or more. When the hydroxy group (hydroxyl group) content is low, the compatibility between the polyester polyol and the cellulose ester tends to decrease. For this reason, the hydroxy group (hydroxyl group) content is preferably 70% or more, more preferably 90% or more, and still more preferably 99% or more. In this embodiment, a compound having a hydroxy group (hydroxyl group) content of 50% or less is not included in the polyester polyol because one of the end groups is substituted with a group other than the hydroxy group (hydroxyl group).

The hydroxy group (hydroxyl group) content can be determined by the following formula (B).
Y / X × 100 = hydroxy group (hydroxyl group) content (%) (B)
X: Hydroxyl group (hydroxyl group) value (OHV) of the polyester polyol
Y: 1 / (number average molecular weight (Mn)) × 56 × 2 × 1000

  The polyester polyol preferably has a number average molecular weight within a range of 300 to 3,000, and more preferably has a number average molecular weight of 350 to 2,000.

  Moreover, it is preferable that the dispersion degree of the molecular weight of the polyester polyol of this embodiment is 1.0-3.0, and it is more preferable that it is 1.0-2.0. When the degree of dispersion is within the above range, a polyester polyol excellent in compatibility with the cellulose ester is easily obtained.

  The polyester polyol preferably contains 50% or more of a component having a molecular weight of 300 to 1800. By setting the number average molecular weight within the above range, the compatibility can be greatly improved.

  The end-capped polyester may be a monocarboxylic acid residue at least one of the two end groups B. That is, one of the two terminal groups B may be a hydroxy group and the other may be a monocarboxylic acid residue. However, it is preferable that both of the two terminal groups B are monocarboxylic acid residues.

  As the terminal group B, the benzene monocarboxylic acid residue and the aliphatic monocarboxylic acid residue described above can be used, and preferably the benzene monocarboxylic acid residue can be used. That is, the end-capped polyester is preferably an aromatic terminal polyester.

  The end-capped polyester is composed of glycol (a component corresponding to G in the general formula (A)), a dicarboxylic acid or an ester-forming derivative thereof (a component corresponding to A in the general formula (A)) and a monocarboxylic acid or These ester-forming derivatives (components corresponding to B in the general formula (A)) can be obtained by an esterification reaction. For example, JP 2011-52205 A, JP 2008-69225 A, It can be synthesized with reference to Kaikai 2008-88292, JP-A 2008-115221 and the like.

  The ester compound of the present embodiment is a mixture having a distribution in molecular weight and molecular structure at the time of its synthesis. Among them, preferred components for the present embodiment, for example, phthalic acid residues as A in the general formula (A) and It is preferable to contain at least one polyester compound having an adipic acid residue.

  The end-capped polyester has a number average molecular weight of preferably 300-1500, more preferably 400-1000. The acid value is 0.5 mg KOH / g or less, the hydroxy (hydroxyl group) value is 25 mg KOH / g or less, more preferably the acid value is 0.3 mg KOH / g or less, and the hydroxy (hydroxyl group) value is 15 mg KOH / g or less.

  Although the specific compound of the polyester (ester type compound) which can be used by this embodiment below is shown, this embodiment is not limited to this.

  The sugar ester (sugar ester compound) is an ester other than cellulose ester, and is a compound obtained by esterifying all or part of the OH group of a sugar such as the following monosaccharide, disaccharide, trisaccharide, or oligosaccharide. More specific examples include compounds represented by the general formula (1).

In the formula, R _{1 to} R ₈ represent a hydrogen atom, a substituted or unsubstituted alkylcarbonyl group having 2 to 22 carbon atoms, or a substituted or unsubstituted arylcarbonyl group having 2 to 22 carbon atoms. R _{1 to} R ₈ may be the same or different.

Although the compound shown by General formula (1) is shown more concretely below (compound 1-1-compound 1-23), it is not limited to these. In the following table, when the average degree of substitution is less than 8.0, any one of R _{1 to} R ₈ represents a hydrogen atom.

  These plasticizers are preferably added in an amount of 0.5 to 30 parts by mass with respect to 100 parts by mass of the cellulose ester film.

[Hard coat layer]
In the present embodiment, a hard coat layer as a functional layer may be formed on the surface of the optical film. The hard coat layer is preferably composed of, for example, an active energy ray curable resin.

(Active energy ray-curable resin)
The active energy ray-curable resin refers to a resin that cures through a crosslinking reaction or the like by irradiation with active rays such as ultraviolet rays or electron beams, and specifically, a resin having an ethylenically unsaturated group. More specifically, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, an ultraviolet curable epoxy resin, or the like is preferably used. Of these, ultraviolet curable acrylate resins are preferred.

  As the ultraviolet curable acrylate resin, a polyfunctional acrylate is preferable. The polyfunctional acrylate is preferably selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. Here, the polyfunctional acrylate is a compound having two or more acryloyloxy groups or methacryloyloxy groups in the molecule.

  Examples of the polyfunctional acrylate monomer include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethane triacrylate. , Tetramethylolmethane tetraacrylate, pentaglycerol triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, glycerol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Lithol hexaacrylate, tris (acryloyloxyethyl) isocyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, Tetramethylol methane trimethacrylate, tetramethylol methane tetramethacrylate, pentaglycerol trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, glycerol trimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetramethacrylate Acrylate, dipentaerythritol penta methacrylate, dipentaerythritol hexa methacrylate, etc. isocyanurate derivatives of the active energy ray-curable are preferably exemplified. Commercially available products may be used as these polyfunctional acrylates, such as pentaerythritol tri / tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., A-TMM-3L), pentaerythritol triacrylate (manufactured by Kyoeisha Chemical Co., Ltd., PE-3A). Etc. can be obtained. In addition, these compounds are used individually or in mixture of 2 or more types, respectively.

  The isocyanurate derivative of the active energy ray-curable resin is not particularly limited as long as it has a structure in which one or more ethylenically unsaturated groups are bonded to the isocyanuric acid skeleton, but there are three in the same molecule. Compounds having the above ethylenically unsaturated groups and one or more isocyanurate rings are preferred.

  A commercial item can also be used as such an isocyanuric acid triacrylate compound, for example, Shin-Nakamura Chemical Co., Ltd. A-9300 etc. are mentioned. As a commercial item of an isocyanuric acid diacrylate compound, Toagosei Co., Ltd. Aronix M-215 etc. are mentioned, for example. Examples of the mixture of the isocyanuric acid triacrylate compound and the isocyanuric acid diacrylate compound include Aronix M-315 and Aronix M-313 manufactured by Toagosei Co., Ltd. As the ε-caprolactone-modified active energy ray-curable isocyanurate derivative, A-9300-1CL manufactured by Shin-Nakamura Chemical Co., Ltd., which is ε-caprolactone-modified tris- (acryloxyethyl) isocyanurate, manufactured by Toagosei Co., Ltd. Examples include, but are not limited to, Aronix M-327.

  Further, as the active energy ray curable resin, a monofunctional acrylate may be used. Monofunctional acrylates include isobornyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, isostearyl acrylate, benzyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, lauryl acrylate, isooctyl acrylate, tetrahydrofurfuryl acrylate, behenyl Examples include acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and cyclohexyl acrylate. Monofunctional acrylates can be obtained from Shin Nakamura Chemical Co., Ltd., Osaka Organic Chemical Industry Co., Ltd., and the like. These compounds are used alone or in admixture of two or more. Moreover, oligomers, such as a dimer and a trimer of the said monomer, may be sufficient.

  Further, urethane acrylate may be used as the active energy ray curable resin. As urethane acrylate, for example, commercially available products such as Beam Set 575CB manufactured by Arakawa Chemical Industries, Ltd. and UA-306H manufactured by Kyoeisha Chemical Co., Ltd. can be used.

  The viscosity of the polyfunctional acrylate as described above is preferably 3000 mPa · s or less, more preferably 1500 mPa · s or less, at 25 ° C. Particularly preferably, it is 1000 mPa · s or less. Examples of such a low viscosity resin include glycerin triacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate. In addition, the said viscosity is the value measured on 25 degreeC conditions using the E-type viscosity meter.

  The compounding amount of the active energy ray-curable resin in the hard coat layer composition is usually 10 to 99 parts by mass, preferably 35 to 99 parts by mass when the entire composition is 100 parts by mass. When the blending amount of the active energy ray-curable resin is small, it is difficult to obtain sufficient film strength of the hard coat layer. Moreover, when there are many compounding quantities, since malfunctions, such as a film thickness uniformity at the time of apply | coating with the well-known coating method mentioned later and an application | coating streak, are not preferable.

(Cationically polymerizable compound)
The hard coat layer may further contain a cationically polymerizable compound. The cationically polymerizable compound is a resin that undergoes cationic polymerization by energy active ray irradiation or heat. Specific examples include an epoxy group, a cyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro orthoester compound, and a vinyloxo group. Among them, a compound having a functional group such as an epoxy group or a vinyl ether group is preferably used in the present embodiment.

  Examples of the cationically polymerizable compound having an epoxy group or a vinyl ether group include phenyl glycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, vinylcyclohexene dioxide, limonene dioxide, 3,4-epoxycyclohexylmethyl-3 ′. , 4'-epoxycyclohexanecarboxylate, bis- (6-methyl-3,4-epoxycyclohexyl) adipate, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, 1 , 4-cyclohexanedimethanol divinyl ether and the like. Moreover, a polymer compound can also be used as an epoxy compound.

  When the cationic polymerizable compound is contained in the hard coat layer composition, the amount of the cationic polymerizable compound in the hard coat layer composition is usually 1 to 90 parts by mass when the entire composition is 100 parts by mass. The amount is preferably 1 to 50 parts by mass.

(Fine particles)
The hard coat layer may contain fine particles. Examples of the fine particles include inorganic fine particles and organic fine particles. As inorganic particles, silica, titanium oxide, aluminum oxide, tin oxide, indium oxide, ITO, zinc oxide, zirconium oxide, magnesium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated Mention may be made of calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. As organic particles, polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder, Examples thereof include polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, and polyfluorinated ethylene resin powder. The average particle diameter of these fine particles is preferably 30 nm to 200 nm from the stability and clearness of the hard coat layer coating composition. The hard coat layer may contain two or more kinds of fine particles having different particle sizes. From the viewpoint of easily achieving the desired pencil hardness, the hard coat layer preferably contains silica fine particles.

  Moreover, it is preferable to make the hard coat layer contain reactive silica fine particles (Xa) surface-treated with an organic compound having a polymerizable unsaturated group from the viewpoint of better exhibiting the effects of the present embodiment. Hereinafter, the reactive silica fine particles (Xa) surface-treated with an organic compound having a polymerizable unsaturated group will be described.

<< Reactive Silica Fine Particles (Xa) >>
Known silica fine particles can be used. The shape may be spherical or irregular, and is not limited to normal colloidal silica, and may be hollow particles, porous particles, core / shell particles, etc., but the pH is 2.0-6. .5 colloidal silica is preferred.

  The dispersion medium of the silica fine particles is preferably water or an organic solvent. Examples of organic solvents include alcohols such as methanol, isopropyl alcohol, ethylene glycol, butanol and ethylene glycol monopropyl ether; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene and xylene; dimethylformamide and dimethyl Examples include amides such as acetamide and N-methylpyrrolidone; esters such as ethyl acetate, butyl acetate and γ-butyrolactone; and organic solvents such as ethers such as tetrahydrofuran and 1,4-dioxane. Of these, alcohols and ketones are preferred. These organic solvents can be used alone or in combination as a dispersion medium. As a commercial item, Nissan Chemical Industry Co., Ltd. MEK-ST-L, MEK-ST-MS, IPA-ST-L, IPA-ST-ZL etc. can be mentioned as colloidal silica, for example.

  The reactive silica fine particles (Xa) are obtained by surface-treating the colloidal silica as described above with an organic compound having a polymerizable unsaturated group (hereinafter referred to as “organic compound (X)”). The organic compound (X) has a polymerizable unsaturated group, preferably an ethylenically unsaturated group, and further has a group represented by the following general formula (a) and a compound having a silanol group in the molecule or a silanol group by hydrolysis. It is preferable that it is a compound to be formed.

  Specifically, [—U—C (═V) —NH—] includes [—O—C (═O) —NH—], [—O—C (═S) —NH—], [— S—C (═O) —NH—], [—NH—C (═O) —NH—], [—NH—C (═S) —NH—], and [—S—C (═S). -NH-]. These groups can be used alone or in combination of two or more. Among these, from the viewpoint of thermal stability, a [—O—C (═O) —NH—] group and a [—O—C (═S) —NH—] group or [—S—C (═O) — It is preferable to use in combination with at least one of the NH— groups.

  Although there is no restriction | limiting in particular as an ethylenically unsaturated group contained in organic compound (X), For example, an acryloyl group, a methacryloyl group, and a vinyl group can be mentioned as a suitable example. This ethylenically unsaturated group is a structural unit that undergoes addition polymerization with active radical species.

  Examples of the compound that generates a silanol group include compounds in which an alkoxy group, an aryloxy group, an acetoxy group, an amino group, a halogen atom, and the like are bonded to a silicon atom, but an alkoxy group or an aryloxy group is bonded to a silicon atom. The compound thus obtained, that is, an alkoxysilyl group-containing compound or an aryloxysilyl group-containing compound is preferred. Specific examples include compounds represented by the following general formula (b).

In the general formula (b), R ²¹ and R ²² may be the same or different, and are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group, for example, methyl, ethyl, propyl, butyl, octyl , Phenyl, xylyl group and the like. Here, j is an integer of 1 to 3.

Examples of the group represented by [(R ²¹ O) _j R ²² _3-j Si—] include a trimethoxysilyl group, a triethoxysilyl group, a triphenoxysilyl group, a methyldimethoxysilyl group, and a dimethylmethoxysilyl group. Can be mentioned. Of these groups, a trimethoxysilyl group or a triethoxysilyl group is preferable.

R ²³ is a divalent organic group having an aliphatic or aromatic structure having 1 to 12 carbon atoms, and may contain a chain, branched or cyclic structure. Specific examples include methylene, ethylene, propylene, butylene, hexamethylene, cyclohexylene, phenylene, xylylene, dodecamethylene and the like.

R ²⁴ is a divalent organic group, and is usually selected from divalent organic groups having a molecular weight of 14 to 10,000, preferably a molecular weight of 76 to 500. Specific examples include a chain polyalkylene group such as hexamethylene, octamethylene, and dodecamethylene; an alicyclic or polycyclic divalent organic group such as cyclohexylene and norbornylene; and 2 such as phenylene, naphthylene, biphenylene, and polyphenylene. Valent aromatic group; and these alkyl group-substituted and aryl group-substituted products. These divalent organic groups may contain an atomic group containing an element other than carbon and hydrogen atoms, and may contain a polyether bond, a polyester bond, a polyamide bond, and a polycarbonate bond.

R ²⁵ is a (k + 1) -valent organic group, preferably selected from a chain, branched or cyclic saturated hydrocarbon group and unsaturated hydrocarbon group.

  Z represents a monovalent organic group having a polymerizable unsaturated group in the molecule that undergoes an intermolecular crosslinking reaction in the presence of an active radical species. K is preferably an integer of 1 to 20, more preferably an integer of 1 to 10, and particularly preferably an integer of 1 to 5.

  The organic compound (X) is, for example, one or more compounds selected from hydrolyzable silanes, polyisocyanate compounds, polythioisocyanate compounds, and compounds having both isocyanate groups and thioisocyanate groups. And an active hydrogen-containing polymerizable unsaturated compound having an active hydrogen atom that causes an addition reaction with an isocyanate group or a thioisocyanate group can be directly added.

  Preferably, mercaptopropyltrimethoxysilane and isophorone diisocyanate are mixed in the presence of dibutyltin dilaurate and reacted at 60 to 70 ° C. for several hours, then pentaerythritol triacrylate is added, and further at 60 to 70 ° C. for several hours. React to a certain extent.

  Next, the obtained organic compound (X) is mixed with silica fine particles, hydrolyzed, and the two are combined to produce reactive silica fine particles (Xa).

  The amount of the organic compound (X) bonded to the silica fine particles is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 1% by mass or more, based on 100% by mass of the silica fine particles. It is.

  If it is the said range, the dispersibility of the reactive silica fine particle (Xa) in a composition will be favorable. Moreover, the compounding ratio of the silica fine particles in the raw material during the production of the reactive silica fine particles (Xa) is preferably 5 to 99% by mass, and more preferably 10 to 98% by mass. The content of the reactive silica fine particles (Xa) in the hard coat layer coating composition is preferably 5 to 80% by mass, and preferably 10 to 80% by mass when the total solid content in the composition is 100% by mass. % Is more preferable. By using in such a range, the reactive silica fine particles (Xa) are stably present in the hard coat coating composition.

  Moreover, it is preferable that a hard-coat layer contains the active energy ray-curable resin and microparticles | fine-particles which were mentioned above, and is active energy ray-curable resin: microparticles | fine-particles = 90: 10-20: 80 by content ratio.

(Other additives, manufacturing method of hard coat layer)
The hard coat layer preferably further contains a photopolymerization initiator in order to accelerate the curing of the active energy ray-curable resin. As a compounding quantity of a photoinitiator, it is preferable by mass ratio that it is photoinitiator: active energy ray hardening-type resin = 20: 100-0.01: 100.

  Specific examples of the photopolymerization initiator include alkylphenone series, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof, but are not particularly limited thereto. It is not a thing. Commercially available products may be used, and preferred examples include Irgacure 184, Irgacure 907, and Irgacure 651 manufactured by BASF Japan.

  Moreover, the hard coat layer may contain the same ultraviolet absorber as the above-mentioned ultraviolet absorber.

  Furthermore, the hard coat layer is composed of two or more layers, and containing the ultraviolet absorber in the hard coat layer in contact with the base film exhibits the object effect of this embodiment well, and the hard coat layer The film strength (abrasion resistance) and the pencil hardness are preferred from the viewpoint of obtaining good results. As content of a ultraviolet absorber, it is preferable to contain by mass ratio with a ultraviolet absorber: hard-coat layer composition = 0.01: 100-10: 100.

  When two or more hard coat layers are provided, the thickness of the hard coat layer in contact with the base film is preferably in the range of 0.05 to 2 μm. Two or more layers may be formed as a simultaneous multilayer. The simultaneous multi-layer is to form a hard coat layer by applying two or more hard coat layers on a base material without going through a drying step. In order to laminate the second hard coat layer on the first hard coat layer without a drying process, the layers are stacked one after another by an extrusion coater or simultaneously by a slot die having a plurality of slits. Can be done.

  In addition, as a method for creating a hard coat layer, a hard coat layer coating composition diluted with a solvent that swells or partially dissolves a cellulose acetate film is applied to the cellulose acetate film by the following method, dried, and cured. The method of providing is preferable from the viewpoint that interlayer adhesion between the hard coat layer and the cellulose acetate film is easily obtained.

  As the solvent for swelling or partially dissolving the cellulose acetate film, a solvent containing a ketone and / or acetate is preferable. Specifically, examples of the ketone include methyl ethyl ketone, acetone, and cyclohexanone. Examples of the acetate ester include ethyl acetate, methyl acetate, and butyl acetate. The hard coat layer coating composition may contain an alcohol solvent as the other solvent.

  The coating amount of the hard coat layer coating composition is preferably 0.1 to 40 μm, more preferably 0.5 to 30 μm, as the wet film thickness. The dry film thickness is preferably about 5 to 20 μm, and preferably 7 to 12 μm.

  The hard coat layer is a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die (extrusion) coater, a hard coat coating composition that forms a hard coat layer is applied using a known coating method such as an inkjet method, After application, the film can be dried, irradiated with actinic radiation (also referred to as UV curing treatment), and further subjected to heat treatment after UV curing as necessary. The heat treatment temperature after UV curing is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 120 ° C. or higher. By performing the heat treatment after UV curing at such a high temperature, the mechanical strength (rubbing resistance, pencil hardness) of the hard coat layer becomes better.

  Drying is preferably performed at a high temperature of 80 ° C. or higher in the rate of decrease drying section. More preferably, the temperature in the decreasing rate drying section is 95 ° C. or higher and 130 ° C. or lower. By setting the temperature of the rate-decreasing drying section to a high temperature and performing the drying process, convection occurs in the coating resin during the formation of the hard coat layer, so that the surface of the hard coat layer is likely to exhibit fine surface roughness. Average roughness Ra is also easily obtained.

  In general, it is known that the drying process changes from a constant state to a gradually decreasing state when drying starts. The interval in which the value decreases is called the rate-of-drying interval. In the constant rate drying section, the amount of heat flowing in is all consumed for solvent evaporation on the coating film surface, and when the solvent on the coating film surface decreases, the evaporation surface moves from the surface to the inside and enters the decreasing rate drying section. Thereafter, the temperature of the coating film surface rises and approaches the hot air temperature, so that the temperature of the ultraviolet curable resin composition rises, the resin viscosity decreases, and the fluidity increases.

  As a light source for UV curing treatment, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used.

Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 50 to 1000 mJ / cm ² , preferably 50 to 300 mJ / cm ² .

  Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is usually 30 to 500 N / m, preferably 30 to 300 N / m. The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. Thereby, a film having further excellent flatness can be obtained.

  The hard coat layer may contain a conductive agent in order to impart antistatic properties, and preferred conductive agents include metal oxide particles or π-conjugated conductive polymers. An ionic liquid is also preferably used as the conductive compound.

  Further, the hard coat layer may contain a fluorine-siloxane graft polymer or a silicone surfactant.

  The fluorine-siloxane graft polymer refers to a copolymer polymer obtained by grafting polysiloxane containing siloxane and / or organosiloxane alone and / or organopolysiloxane to at least a fluorine-based resin. Examples of commercially available products include ZX-022H, ZX-007C, ZX-049, and ZX-047-D manufactured by Fuji Kasei Kogyo Co., Ltd.

  The silicone-based surfactant is a surfactant obtained by substituting a part of the methyl group of the silicone oil with a hydrophilic group. Examples of the hydrophilic group include polyether, polyglycerin, pyrrolidone, betaine, sulfate, phosphate, and quaternary salt. Specific products of silicone surfactants include, for example, SH200, BY16-873, PRX413 (dimethylsilicone oil; manufactured by Toray Dow Corning Silicone Co., Ltd.), SH203, SH230, SF8416 (alkyl-modified silicone oil; Toray Dow Corning Silicone Co., Ltd.), SF8417, BY16-208, BY16-209, BY16-849, BY16-872, FZ-2222, FZ-2207 (dimethylpolysiloxane / polyethylene oxide linear block copolymer; Japan) Unicar Co., Ltd. FZ series), KF-101, KF-102, KF-105 (epoxy-modified silicone oil; manufactured by Shin-Etsu Chemical Co., Ltd.), BYK-UV3500, BYK-UV3510, BYK-333, BYK- 31, BYK-337 (polyether-modified silicone oil, Bikkukemi - Japan Ltd.), but like without limitation.

  Moreover, it is preferable to add these components in 0.01-5 mass% with respect to the solid content component in a coating liquid.

(Surface shape of hard coat layer)
The arithmetic average roughness Ra of the surface of the hard coat layer in the present embodiment is preferably 4 to 20 nm from the viewpoint of excellent anti-blocking effect when wound with a long film and excellent adhesion to the cellulose acetate film. . The arithmetic average roughness Ra is a value measured with an optical interference type surface roughness meter (RST / PLUS, manufactured by WYKO) based on the provisions of JIS B0601: 1994.

Moreover, as for uneven | corrugated average space | interval Sm on the surface of a hard-coat layer, 3-40 micrometers is preferable. Further, the ratio (Ra / Sm) between the arithmetic average roughness Ra of the surface of the hard coat layer and the uneven average interval Sm of the hard coat layer coating surface of the cellulose ester film (film substrate) is 2 × 10 ^−4. It is preferably ˜6 × 10 ⁻³ . Sm can be measured with an optical interference surface roughness meter (RST / PLUS, manufactured by WYKO) based on the provisions of JIS B0601: 1994, similarly to the arithmetic average roughness Ra.

  In order to make the arithmetic average roughness Ra of the surface of the hard coat layer within the above range, a method of forming protrusions on the surface by pressing a mold or a resin having a different SP value (solubility parameter) is mixed to form surface irregularities And a method of forming protrusions by spinodal decomposition or nucleation can be used.

  In addition, as the mold roll used for forming the protrusion, it is possible to select and apply appropriately from fine to rough unevenness, and use a mat-like, lenticular lens-like, or spherical irregularity regularly or randomly arranged it can.

  In addition, the haze value of the hard coat film of the present embodiment is preferably 1% or less from the viewpoint of obtaining sufficient luminance and high contrast.

[Functional layer]
(Back coat layer)
A back coat layer may be provided on the surface of the film substrate of the present embodiment opposite to the side on which the hard coat layer is provided to prevent curling and blocking.

  In terms of curling and blocking prevention, the back coat layer includes silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, indium oxide, Particles such as zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate can be added.

  The particles contained in the backcoat layer are preferably 0.1 to 50% by mass with respect to the binder. When the back coat layer is provided, the increase in haze is preferably 0.5% or less, and particularly preferably 0.1% or less. As the binder, a cellulose ester resin is preferable. The coating composition for forming the backcoat layer preferably contains a solvent for alcohols, ketones and / or acetate ester sugars.

(Antireflection layer)
In the present embodiment, a hard coat layer can be formed on a film substrate, and an antireflection layer can be coated on the hard coat layer to be used as an antireflection film having an external light antireflection function.

  The antireflection layer is preferably laminated in consideration of the refractive index, the film thickness, the number of layers, the layer order, and the like so that the reflectance is reduced by optical interference. The antireflection layer is composed of a low refractive index layer having a refractive index lower than that of the film substrate as a support, or a combination of a high refractive index layer having a refractive index higher than that of the support and a low refractive index layer. Is preferred. Particularly preferably, it is an antireflection layer composed of three or more refractive index layers, and three layers having different refractive indexes from the support side are divided into medium refractive index layers (high refractive index layers having a higher refractive index than the support). Are preferably laminated in the order of a layer having a lower refractive index) / a high refractive index layer / a low refractive index layer. Alternatively, an antireflection layer having a layer structure of four or more layers in which two or more high refractive index layers and two or more low refractive index layers are alternately laminated is also preferably used.

  As the layer structure of the film having the antireflection layer, the following structure is conceivable, but is not limited thereto.

Cellulose acetate film / hard coat layer / low refractive index layer Cellulose acetate film / hard coat layer / medium refractive index layer / low refractive index layer Cellulose acetate film / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index Layer Cellulose acetate film / hard coat layer / high refractive index layer (conductive layer) / low refractive index layer Cellulose acetate film / hard coat layer / antiglare layer / low refractive index layer

(Low refractive index layer)
The low refractive index layer preferably contains silica-based fine particles, and the refractive index is preferably in the range of 1.30 to 1.45 when measured at 23 ° C. and a wavelength of 550 nm.

  The film thickness of the low refractive index layer is preferably 5 nm to 0.5 μm, more preferably 10 nm to 0.3 μm, and most preferably 30 nm to 0.2 μm.

  The composition for forming a low refractive index layer preferably contains at least one kind of particles having an outer shell layer and porous or hollow inside as silica-based fine particles. In particular, the particles having the outer shell layer and having a porous or hollow interior are preferably hollow silica-based fine particles.

  The composition for forming a low refractive index layer may contain an organosilicon compound represented by the following general formula (OSi-1), a hydrolyzate thereof, or a polycondensate thereof.

General formula (OSi-1): Si (OR) ₄
In the organic silicon compound represented by the general formula, R represents an alkyl group having 1 to 4 carbon atoms. Specifically, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and the like are preferably used.

  In addition, a silane coupling agent, a curing agent, a surfactant and the like may be added as necessary. Further, it may contain a compound having a thermosetting property and / or a photocurable property mainly containing a fluorine-containing compound containing a fluorine atom in a range of 35 to 80% by mass and containing a crosslinkable or polymerizable functional group. . Specifically, a fluorine-containing polymer or a fluorine-containing sol-gel compound is used. As the fluorine-containing polymer, for example, a hydrofluorinated monomer in addition to a hydrolyzate or dehydration condensate of a perfluoroalkyl group-containing silane compound [for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane] Examples thereof include fluorine-containing copolymers having units and cross-linking reactive units as constituent units. In addition, you may add a solvent, a silane coupling agent, a hardening | curing agent, surfactant, etc. as needed.

(High refractive index layer)
The refractive index of the high refractive index layer is preferably adjusted to a refractive index in the range of 1.4 to 2.2 by measuring at 23 ° C. and a wavelength of 550 nm. The thickness of the high refractive index layer is preferably 5 nm to 1 μm, more preferably 10 nm to 0.2 μm, and most preferably 30 nm to 0.1 μm. The refractive index can be adjusted by adding metal oxide fine particles and the like. The metal oxide fine particles used preferably have a refractive index of 1.80 to 2.60, more preferably 1.85 to 2.50.

  The kind of metal oxide fine particles is not particularly limited, and Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P and S A metal oxide having at least one element selected from can be used. These metal oxide fine particles may be doped with a trace amount of atoms such as Al, In, Sn, Sb, Nb, a halogen element, and Ta. A mixture of these may also be used. In the present embodiment, at least one metal oxide selected from zirconium oxide, antimony oxide, tin oxide, zinc oxide, indium-tin oxide (ITO), antimony-doped tin oxide (ATO), and zinc antimonate, among others. It is particularly preferable to use fine particles as the main component. In particular, it is preferable to contain zinc antimonate particles.

  The average particle diameter of the primary particles of these metal oxide fine particles is in the range of 10 nm to 200 nm, particularly preferably 10 to 150 nm. The average particle diameter of the metal oxide fine particles can be measured from an electron micrograph taken with a scanning electron microscope (SEM) or the like. You may measure by the particle size distribution meter etc. which utilize a dynamic light scattering method, a static light scattering method, etc. If the particle size is too small, aggregation tends to occur and the dispersibility deteriorates. If the particle size is too large, the haze is remarkably increased, which is not preferable. The shape of the metal oxide fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, a needle shape, or an indefinite shape.

  The metal oxide fine particles may be surface-treated with an organic compound. By modifying the surface of the metal oxide fine particles with an organic compound, the dispersion stability in an organic solvent is improved, the dispersion particle size can be easily controlled, and aggregation and sedimentation over time can be suppressed. . For this reason, the surface modification amount with a preferable organic compound is 0.1 mass%-5 mass% with respect to metal oxide particle, More preferably, it is 0.5 mass%-3 mass%. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Of these, silane coupling agents are preferred. Two or more kinds of surface treatments may be combined.

  The high refractive index layer may contain a π-conjugated conductive polymer. The π-conjugated conductive polymer can be used as long as it is an organic polymer having a main chain composed of a π-conjugated system. Examples thereof include polythiophenes, polypyrroles, polyanilines, polyphenylenes, polyacetylenes, polyphenylene vinylenes, polyacenes, polythiophene vinylenes, and copolymers thereof. From the viewpoint of ease of polymerization and stability, polythiophenes, polyanilines, and polyacetylenes are preferable.

  The π-conjugated conductive polymer can provide sufficient conductivity and solubility in a binder resin even if it is not substituted, but in order to further improve conductivity and solubility, an alkyl group, a carboxy group, a sulfo group, an alkoxy group. A functional group such as a group, a hydroxy group, or a cyano group may be introduced.

The high refractive index layer may contain an ionic compound. Examples of the ionic compound include imidazolium-based, pyridium-based, alicyclic amine-based, aliphatic amine-based, aliphatic phosphonium-based cations and inorganic ion-based compounds such as BF ₄ -and PF _6- , CF ₃ SO _2-, and the like. , (CF ₃ SO ₂ ) ₂ N—, a compound composed of a fluorine-based anion such as CF ₃ CO ₂ —, and the like. The ratio of the polymer to the binder is preferably 10 to 400 parts by mass of the binder with respect to 100 parts by mass of the polymer, and particularly preferably 100 to 200 parts by mass of the binder with respect to 100 parts by mass of the polymer.

(Anti-glare layer)
On the hard coat layer, an antiglare layer can be provided as a functional layer. The antiglare layer reduces the visibility of the reflected image by blurring the outline of the image reflected on the film surface, so that the reflected image is reflected when using an image display device such as a liquid crystal display, an organic EL display, or a plasma display. It is a layer that keeps you from worrying. Specifically, the antiglare layer has an arithmetic average roughness Ra of 0.1 to 0.1 by adding fine particles to the hard coat layer or a method of forming protrusions on the surface by pressing the mold. A layer adjusted to 1 μm is preferable.

  Moreover, it is preferable that the ratio (scattering reflection ratio) of the scattering reflectance which occupies for the integral reflectance of the said glare-proof layer is 2 to 60%. By controlling the scattering reflection ratio within the above range using fine particles or the like, the interlayer adhesion between the cellulose acetate film having a high acetylation degree as described above and the antiglare layer can be improved. More preferably, if the ratio of the scattering reflection ratio is in the range of 20 to 50%, the adhesion can be improved.

  The scattering reflectance ratio is SCI (integrated reflectance) and SCE (scattering reflectance) using a spectrocolorimeter CM-2500d manufactured by Konica Minolta Co., Ltd. under the conditions of a measurement diameter of 8 mm and an observation field of view of 2 °. Can be determined by measuring.

[Conductive layer]
In the present embodiment, a conductive layer may be formed on the outermost surface of the optical film (for example, on the hard coat layer). The conductive layer preferably contains at least conductive fibers, and further contains a binder, a photosensitive compound, and, if necessary, other components.

(Conductive fiber)
There is no restriction | limiting in particular as a structure of an electroconductive fiber, Although it can select suitably according to the objective, It is preferable that it is either a solid structure or a hollow structure.

  Here, the solid structure fiber may be referred to as a wire, and the hollow structure fiber may be referred to as a tube.

  In addition, a conductive fiber having an average minor axis length of 5 nm to 1,000 nm and an average major axis length of 1 μm to 100 μm may be referred to as “nanowire”.

  In addition, conductive fibers having an average minor axis length of 1 nm to 1,000 nm and an average major axis length of 0.1 μm to 1,000 μm and having a hollow structure may be referred to as “nanotubes”.

  The material of the conductive fiber is not particularly limited as long as it has conductivity, and can be appropriately selected according to the purpose, but is preferably at least one of metal and carbon. Among these, the conductive fibers are preferably at least one of metal nanowires, metal nanotubes, and carbon nanotubes.

<Metal nanowires>
There is no restriction | limiting in particular as a material of metal nanowire, According to the objective, it can select suitably. For example, at least one metal selected from the group consisting of the fourth period, the fifth period, and the sixth period of the Long Periodic Table (IUPAC 1991) is preferred, and at least one kind selected from Group 2 to Group 14 is preferred. Metal is more preferable, and at least one metal selected from Group 2, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13, and Group 14 is more preferable. It is particularly preferable to include it as a component.

  Examples of the metal include copper, silver, gold, platinum, palladium, nickel, tin, cobalt, rhodium, iridium, iron, ruthenium, osmium, manganese, molybdenum, tungsten, niobium, tantel, titanium, bismuth, antimony, and lead. Or alloys thereof. Among these, silver and an alloy with silver are preferable in terms of excellent conductivity.

  Examples of the metal used in the alloy with silver include platinum, osmium, palladium, and iridium. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as a shape of metal nanowire, According to the objective, it can select suitably. For example, it can take an arbitrary shape such as a columnar shape, a rectangular parallelepiped shape, or a columnar shape having a polygonal cross section. In applications where high transparency is required, a cylindrical shape or a cross-sectional shape with rounded polygonal corners is preferable. The cross-sectional shape of the metal nanowire can be examined by applying a metal nanowire aqueous dispersion on the substrate and observing the cross-section with a transmission electron microscope (TEM).

  The average minor axis length (sometimes referred to as “average minor axis diameter” or “average diameter”) of the metal nanowires is preferably 1 nm to 50 nm. When the average minor axis length is less than 1 nm, the oxidation resistance deteriorates and the durability may deteriorate. When the average minor axis length exceeds 50 nm, scattering due to metal nanowires occurs and sufficient transparency is obtained. There are times when you can't. The average minor axis length is more preferably 10 nm to 40 nm, and further preferably 15 nm to 35 nm.

  The average short axis length of the metal nanowires was measured using a transmission electron microscope (TEM; manufactured by JEOL Ltd., JEM-2000FX), and 300 metal nanowires were observed. The short axis length was determined. In addition, the short axis length when the short axis of the metal nanowire is not circular was the shortest axis.

  The average major axis length (sometimes referred to as “average length”) of the metal nanowires is preferably 1 μm to 40 μm. If the average major axis length is less than 1 μm, it may be difficult to form a dense network and sufficient conductivity may not be obtained. If it exceeds 40 μm, the metal nanowires are too long and manufactured. Sometimes entangled and agglomerates may occur during the manufacturing process. The average major axis length is more preferably 3 μm to 35 μm, and still more preferably 5 μm to 30 μm.

  The average major axis length of the metal nanowire is, for example, observed with 300 metal nanowires using a transmission electron microscope (TEM; manufactured by JEOL Ltd., JEM-2000FX). The average major axis length was determined. In addition, when the metal nanowire was bent, the circle | round | yen which makes it an arc was considered and the value calculated from the radius and curvature was made into the major axis length.

  Examples of the method for producing metal nanowires include, for example, JP 2009-215594 A, JP 2009-242880 A, JP 2009-299162 A, JP 2010-84173 A, and JP 2010-86714 A. The described method can be used. The method for producing the metal nanowire is not particularly limited and may be produced by any method. By reducing metal ions while heating in a solvent in which a halogen compound and a dispersion additive are dissolved as follows, It is preferable to manufacture.

  The solvent is preferably a hydrophilic solvent, and examples thereof include water, alcohols, ethers, and ketones. These may be used alone or in combination of two or more. Examples of the alcohols include methanol, ethanol, propanol, isopropanol, butanol, and ethylene glycol. Examples of the ethers include dioxane and tetrahydrofuran. Examples of the ketones include acetone.

  The heating temperature at the time of the heating is preferably 250 ° C. or less, and more preferably 20 ° C. to 200 ° C. The lower the heating temperature, the lower the probability of nucleation, and if the heating temperature is less than 20 ° C., the metal nanowires become too long and become easily entangled, and the dispersion stability may deteriorate. On the other hand, when the heating temperature exceeds 250 ° C., the corner of the cross section of the metal nanowire becomes steep, and the transmittance in the evaluation of the coating film may be lowered. In addition, it is more preferable that heating temperature is 30 degreeC-180 degreeC, and it is still more preferable that it is 40 degreeC-170 degreeC.

  In addition, you may change temperature in the formation process of metal nanowire as needed. By changing the temperature in the middle, it is possible to improve the monodispersity improvement effect by controlling the nucleation of metal nanowires, suppressing renucleation, and promoting selective growth.

  The heating is preferably performed by adding a reducing agent. There is no restriction | limiting in particular as a reducing agent, It can select suitably from what is normally used. For example, borohydride metal salt, aluminum hydride salt, alkanolamine, aliphatic amine, heterocyclic amine, aromatic amine, aralkylamine, alcohol, organic acid, reducing sugar, sugar alcohol, sodium sulfite, hydrazine compound, Examples include dextrin, hydroquinone, hydroxylamine, ethylene glycol, and glutathione. Among these, reducing sugars, sugar alcohols as derivatives thereof, and ethylene glycol are particularly preferable.

  Examples of the borohydride metal salt include sodium borohydride and potassium borohydride.

  Examples of the aluminum hydride salt include lithium aluminum hydride, potassium aluminum hydride, cesium aluminum hydride, beryllium aluminum hydride, magnesium aluminum hydride, and calcium aluminum hydride.

  Examples of the alkanolamine include diethylaminoethanol, ethanolamine, propanolamine, triethanolamine, dimethylaminopropanol, and the like.

  Examples of the aliphatic amine include propylamine, butylamine, dipropyleneamine, ethylenediamine, and triethylenepentamine.

  Examples of the heterocyclic amine include piperidine, pyrrolidine, N-methylpyrrolidine, morpholine, and the like.

  Examples of the aromatic amine include aniline, N-methylaniline, toluidine, anisidine, and phenetidine.

  Examples of the aralkylamine include benzylamine, xylenediamine, and N-methylbenzylamine.

  Examples of the alcohol include methanol, ethanol, 2-propanol and the like.

  Examples of the organic acids include citric acid, malic acid, tartaric acid, citric acid, succinic acid, ascorbic acid, and salts thereof.

  Examples of the reducing saccharide include glucose, galactose, mannose, fructose, sucrose, maltose, raffinose, and stachyose.

  Examples of the sugar alcohols include sorbitol.

  Depending on the reducing agent, it may function as a dispersion additive or a solvent as a function, and can be preferably used in the same manner.

  In the production of the metal nanowire, it is preferable to add a dispersion additive and a halogen compound or metal halide fine particles. The timing of the addition of the dispersion additive and the halogen compound may be before or after the addition of the reducing agent, and may be before or after the addition of metal ions or metal halide fine particles. In order to obtain the above, the addition of the halogen compound is preferably divided into two or more steps.

  There is no restriction | limiting in particular as said dispersion | distribution additive, According to the objective, it can select suitably. Examples thereof include amino group-containing compounds, thiol group-containing compounds, sulfide group-containing compounds, amino acids or derivatives thereof, peptide compounds, polysaccharides, synthetic polymers, and gels derived from these. Among these, gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, polyalkyleneamine, partial alkyl ester of polyacrylic acid, polyvinyl pyrrolidone, and polyvinyl pyrrolidone copolymer are particularly preferable.

  For the structure that can be used as the dispersion additive, for example, the description of “Encyclopedia of Pigments” (edited by Seijiro Ito, published by Asakura Shoin Co., Ltd., 2000) can be referred to.

  Moreover, the shape of the metal nanowire obtained can also be changed with the kind of dispersion additive to be used.

  The halogen compound is not particularly limited as long as it is a compound containing bromine, chlorine, and iodine, and can be appropriately selected according to the purpose. For example, preferred are alkali halides such as sodium bromide, sodium chloride, sodium iodide, potassium iodide, potassium bromide, potassium chloride, potassium iodide, and compounds that can be used in combination with the following dispersion additives. Some of the halogen compounds may function as a dispersion additive, but can be preferably used in the same manner.

  As an alternative to the halogen compound, silver halide fine particles may be used, or both a halogen compound and silver halide fine particles may be used.

  The dispersant and the halogen compound may be used in the same substance. Examples of the compound in which the dispersant and the halogen compound are used in combination include HTAB (hexadecyl-trimethylammonium bromide) containing an amino group and a bromide ion, HTAC (hexadecyl-trimethylammonium chloride) containing an amino group and a chloride ion, and an amino group And bromide or chloride ion containing dodecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, stearyltrimethylammonium bromide, stearyltrimethylammonium chloride, decyltrimethylammonium bromide, decyltrimethylammonium chloride, dimethyldistearylammonium bromide, dimethyldistearylammonium chloride , Dilauryl dimethyl ammonium bromide, dilauryl dimethyl ammonium Umukurorido, dimethyl dipalmityl ammonium bromide, dimethyl dipalmityl ammonium chloride, and the like.

  After forming metal nanowires, desalting may be performed by techniques such as ultrafiltration, dialysis, gel filtration, decantation, and centrifugation.

<Metal nanotubes>
There is no restriction | limiting in particular as a material of a metal nanotube, What kind of metal may be sufficient, For example, the material of the above-mentioned metal nanowire etc. can be used.

  The shape of the metal nanotube may be a single layer or a multilayer, but is preferably a single layer from the viewpoint of excellent conductivity and thermal conductivity.

  The thickness of the metal nanotube (difference between the outer diameter and the inner diameter) is preferably 3 nm to 80 nm. When the thickness is less than 3 nm, the oxidation resistance may be deteriorated and the durability may be deteriorated. When the thickness is more than 80 nm, scattering due to the metal nanotube may occur. The thickness is more preferably 3 nm to 30 nm.

  The average major axis length of the metal nanotube is preferably 1 μm to 40 μm, more preferably 3 μm to 35 μm, and still more preferably 5 μm to 30 μm.

  There is no restriction | limiting in particular as a manufacturing method of the said metal nanotube, According to the objective, it can select suitably. For example, the method described in US Patent Application Publication No. 2005/0056118 and the like can be used.

<carbon nanotube>
A carbon nanotube (CNT) is a substance in which a graphite-like carbon atomic surface (graphene sheet) is a single-layer or multilayer coaxial tube. Single-walled carbon nanotubes are called single-walled nanotubes (SWNT), multi-walled carbon nanotubes are called multi-walled nanotubes (MWNT), and in particular, double-walled carbon nanotubes are also called double-walled nanotubes (DWNT). In the conductive fiber used in the present embodiment, the carbon nanotube may be a single layer or a multilayer, but is preferably a single layer in terms of excellent conductivity and thermal conductivity.

  There is no restriction | limiting in particular as a manufacturing method of a carbon nanotube, According to the objective, it can select suitably. For example, catalytic hydrogen reduction of carbon dioxide, arc discharge method, laser evaporation method, thermal CVD method, plasma CVD method, vapor phase growth method, HiPco in which carbon monoxide is reacted with iron catalyst at high temperature and high pressure to grow in the vapor phase Known means such as a high-pressure carbon monoxide process can be used.

  In addition, the carbon nanotubes obtained by these methods have been highly purified to remove residues such as by-products and catalytic metals by methods such as washing, centrifugation, filtration, oxidation, and chromatography. It is preferable at the point which can obtain a carbon nanotube.

  The conductive fiber preferably has an aspect ratio of 10 or more. The aspect ratio generally means the ratio between the long side and the short side of the fibrous material (ratio of average major axis length / average minor axis length).

  There is no restriction | limiting in particular as a measuring method of an aspect ratio, According to the objective, it can select suitably, For example, the method etc. which measure with an electron microscope etc. are mentioned.

  When measuring the aspect ratio of the conductive fiber with an electron microscope, it is only necessary to confirm whether the aspect ratio of the conductive fiber is 10 or more with one field of view of the electron microscope. Moreover, the aspect ratio of the whole conductive fiber can be estimated by measuring the major axis length and the minor axis length of the conductive fiber separately.

  When the conductive fiber is in a tube shape, the outer diameter of the tube is used as the diameter for calculating the aspect ratio.

  The aspect ratio of the conductive fiber is not particularly limited as long as it is 10 or more, and can be appropriately selected according to the purpose, but is preferably 50 to 1,000,000. When the aspect ratio is less than 10, network formation with conductive fibers may not be performed, and sufficient conductivity may not be obtained. When the aspect ratio exceeds 1,000,000, the conductive fibers may be formed or in subsequent handling. Since the conductive fibers are entangled and aggregate before film formation, a stable liquid may not be obtained. The aspect ratio is more preferably 100 to 1,000,000.

  The ratio (ratio) of conductive fibers having an aspect ratio of 10 or more in the total conductive composition is preferably 50% or more by volume ratio. If the ratio is less than 50%, the conductive material that contributes to conductivity may decrease and conductivity may decrease. At the same time, a dense network cannot be formed, resulting in voltage concentration and durability. May fall. In addition, particles having a shape other than conductive fibers do not contribute greatly to conductivity and have absorption, which is not preferable. Especially in the case of metal, when plasmon absorption such as a sphere is strong, the transparency is deteriorated. May end up. The ratio is more preferably 60% or more, and particularly preferably 75% or more.

  Here, the ratio is, for example, when the conductive fiber is silver nanowire, the silver nanowire aqueous dispersion is filtered to separate the silver nanowire and the other particles, and the ICP emission analysis By measuring the amount of silver remaining on the filter paper and the amount of silver transmitted through the filter paper using an apparatus, the ratio of conductive fibers can be determined. By observing the conductive fibers remaining on the filter paper with a TEM, observing the short axis lengths of 300 conductive fibers and examining their distribution, the short axis length is 200 nm or less and the long axis length is It confirms that it is an electroconductive fiber whose length is 1 micrometer or more. Note that the filter paper measures the longest axis of particles other than the conductive fibers of the above size, and passes particles having a length not less than twice the longest axis and not more than the shortest length of the long axis of the conductive fibers. It is preferable to use one.

  Here, the average minor axis length and the average major axis length of the conductive fiber can be obtained by observing a TEM image or an optical microscope image using, for example, a transmission electron microscope (TEM) or an optical microscope. it can. In this embodiment, the average minor axis length and the average major axis length of the conductive fibers are obtained by observing 300 conductive fibers with a transmission electron microscope (TEM) and calculating the average value. .

<binder>
The binder is an organic high molecular polymer, and at least one group (for example, carboxyl group, phosphate group) that promotes alkali solubility in a molecule (preferably a molecule having an acrylic copolymer as a main chain). , Sulfonic acid groups, etc.) can be selected appropriately from alkali-soluble resins.

  Among these, those that are soluble in an organic solvent and that can be developed with a weak alkaline aqueous solution are preferable, and those that have an acid-dissociable group and become alkali-soluble when the acid-dissociable group is dissociated by the action of an acid. Particularly preferred. In addition, an acid dissociable group represents the functional group which can dissociate in presence of an acid.

  For the production of the binder, for example, a known radical polymerization method can be applied. Polymerization conditions such as temperature, pressure, type and amount of radical initiator, type of solvent, etc. when producing an alkali-soluble resin by the above radical polymerization method can be easily set by those skilled in the art, and the conditions are determined experimentally. Can be determined.

  As the linear organic polymer, a polymer having a carboxylic acid in the side chain (photosensitive resin having an acidic group) is preferable.

  Examples of the polymer having a carboxylic acid in the side chain include, for example, JP-A-59-44615, JP-B-54-34327, JP-B-58-12777, JP-B-54-25957, JP-A-59-53836, A methacrylic acid copolymer, an acrylic acid copolymer, an itaconic acid copolymer, a crotonic acid copolymer, a maleic acid copolymer, and a partial esterification as described in each publication of Japanese Utility Model Publication No. 59-71048. A maleic acid copolymer, etc., an acidic cellulose derivative having a carboxylic acid in the side chain, an acid anhydride added to a polymer having a hydroxyl group, and a polymer weight having a (meth) acryloyl group in the side chain Coalescence is also preferred.

  Among these, benzyl (meth) acrylate / (meth) acrylic acid copolymers and multi-component copolymers composed of benzyl (meth) acrylate / (meth) acrylic acid / other monomers are particularly preferable.

  Furthermore, a high molecular polymer having a (meth) acryloyl group in the side chain and a multi-component copolymer comprising (meth) acrylic acid / glycidyl (meth) acrylate / other monomers are also useful. The polymer can be used by mixing in an arbitrary amount.

  In addition to the above, 2-hydroxypropyl (meth) acrylate / polystyrene macromonomer / benzyl methacrylate / methacrylic acid copolymer, 2-hydroxy-3-phenoxypropyl acrylate / polymethyl described in JP-A-7-140654 Methacrylate macromonomer / benzyl methacrylate / methacrylic acid copolymer, 2-hydroxyethyl methacrylate / polystyrene macromonomer / methyl methacrylate / methacrylic acid copolymer, 2-hydroxyethyl methacrylate / polystyrene macromonomer / benzyl methacrylate / methacrylic acid copolymer Coalescence, etc.

  As a specific structural unit in the alkali-soluble resin, (meth) acrylic acid and other monomers copolymerizable with the (meth) acrylic acid are suitable. Examples of other monomers copolymerizable with the (meth) acrylic acid include alkyl (meth) acrylates, aryl (meth) acrylates, vinyl compounds, and the like. In these, the hydrogen atom of the alkyl group and aryl group may be substituted with a substituent.

  Examples of the alkyl (meth) acrylate or aryl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and pentyl (meth). Acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, tolyl (meth) acrylate, naphthyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meta ) Acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.

Examples of the vinyl compound include styrene, α-methylstyrene, vinyl toluene, glycidyl methacrylate, acrylonitrile, vinyl acetate, N-vinyl pyrrolidone, tetrahydrofurfuryl methacrylate, polystyrene macromonomer, polymethyl methacrylate macromonomer, CH ₂ ═CR. ₁ R ₂ , CH ₂ ═C (R ₁ ) (COOR ₃ ), and the like. However, R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ₂ represents an aromatic hydrocarbon ring having 6 to 10 carbon atoms, R ₃ is an alkyl group or carbon number of 1 to 8 carbon atoms 6-12 aralkyl groups are represented. These may be used individually by 1 type and may use 2 or more types together.

  The weight average molecular weight of the binder is preferably from 1,000 to 500,000, more preferably from 3,000 to 300,000, and even more preferably from 5,000 to 200,000, from the viewpoints of alkali dissolution rate, film physical properties and the like. . In addition, the said weight average molecular weight can be measured using a gel permeation chromatography method, and can be calculated | required using a standard polystyrene calibration curve.

  The content of the binder is preferably 25% by mass to 80% by mass with respect to the entire conductive layer, more preferably 30% by mass to 75% by mass, and still more preferably 40% by mass to 70% by mass. When the content is within the above range, both developability and conductivity of the metal nanowire can be achieved.

<Photosensitive compound>
The said photosensitive compound means the compound which provides the function which forms an image by exposure, or gives the trigger to the conductive layer. Specific examples include (1) a compound that generates acid upon exposure (photoacid generator), (2) a photosensitive quinonediazide compound, and (3) a photoradical generator. These may be used individually by 1 type and may use 2 or more types together. Moreover, a sensitizer etc. can also be used together for sensitivity adjustment.

(Photoacid generator)
Photoacid generator includes photoinitiator for photocationic polymerization, photoinitiator for photoradical polymerization, photodecoloring agent for dyes, photochromic agent, irradiation of actinic ray or radiation used for micro resist, etc. The known compounds that generate an acid and mixtures thereof can be appropriately selected and used.

  There is no restriction | limiting in particular in a photo-acid generator, According to the objective, it can select suitably. Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates. Among these, imide sulfonate, oxime sulfonate, and o-nitrobenzyl sulfonate, which are compounds that generate sulfonic acid, are particularly preferable.

  Further, a group capable of generating an acid upon irradiation with actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the resin, such as US Pat. No. 3,849,137, German Patent No. 3914407. Description, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853 The compounds described in JP-A-63-146029, etc. can be used. Furthermore, compounds capable of generating an acid by light described in each specification such as US Pat. No. 3,779,778 and European Patent 126,712 can also be used.

(Quinonediazide compound)
The quinonediazide compound can be obtained, for example, by subjecting 1,2-quinonediazidesulfonyl chlorides, hydroxy compounds, amino compounds and the like to a condensation reaction in the presence of a dehydrochlorinating agent.

  The compounding amount of the photoacid generator and the quinonediazide compound is from 1 part by mass to 100 parts by mass of the total amount of the binder from the viewpoint of the difference in dissolution rate between the exposed part and the unexposed part and the allowable range of sensitivity. 100 parts by mass is preferable, and 3 parts by mass to 80 parts by mass is more preferable. The photoacid generator and the quinonediazide compound may be used in combination.

  In the present embodiment, among the photoacid generators, compounds that generate sulfonic acid are preferable, and the following oxime sulfonate compounds are particularly preferable from the viewpoint of high sensitivity.

(Adhesive layer)
A touch panel display device can also be configured by adhering the touch panel to the outermost surface of the polarizing plate on the viewing side of the present embodiment (for example, on the hard coat layer) via an adhesive layer. There is no restriction | limiting in particular as said adhesive layer, A well-known adhesive can be used. For example, acrylic adhesives, silicone adhesives, urethane adhesives, rubber adhesives, polyester adhesives, etc. can be used, but acrylic adhesives with relatively easy control of adhesive strength and storage modulus can be used. It is particularly preferred to use it.

  As acrylic adhesives, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, (meth) acrylic 1 or 2 or more kinds of alkyl esters of 1 to 20 carbon atoms such as 2-ethylbutyl acid, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, and the alkyl acrylate Copolymerization with functional monomers such as (meth) acrylic acid, itaconic acid, maleic acid, maleic anhydride, 2-hydroxyethyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate that can be copolymerized with esters In combination, isocyanate crosslinker, epoxy crosslinker, aziridine crosslinker, metal chelate crosslinker It includes a crosslinking agent that is reacted.

  The thickness of the pressure-sensitive adhesive layer is preferably 1 μm to 13 μm. When the thickness of the pressure-sensitive adhesive layer is 1 μm or more, sufficient adhesive strength can be obtained, and when the thickness is 13 μm or less, it is possible to suppress the protrusion of glue during punching or cutting, and high pencil hardness is maintained. . Furthermore, the thickness of a preferable adhesive layer is 3-12 micrometers.

As the storage elastic modulus of the pressure-sensitive adhesive layer, the storage elastic modulus at 0 ° C. is preferably 1.0 × 10 ^{6 to} 1.0 × 10 ⁸ Pa. When the storage elastic modulus of the pressure-sensitive adhesive layer is 1.0 × 10 ⁶ Pa or more, sufficient punching processability, cutting processability and high pencil hardness can be obtained, and when it is 1.0 × 10 ⁸ Pa or less, sufficient adhesion Power is obtained. A preferable storage elastic modulus of the pressure-sensitive adhesive layer is 1.5 × 10 ^{6 to} 1.0 × 10 ⁷ Pa.

  As a method of providing the pressure-sensitive adhesive layer on the hard coat layer, a hard coat film (film base material + hard coat layer) is separately applied to the pressure-sensitive adhesive layer prepared by applying a pressure-sensitive adhesive-containing composition to a release sheet and drying it. The method of laminating is mentioned. Examples of the method for applying the pressure-sensitive adhesive-containing composition include conventionally known methods such as bar coating, knife coating, roll coating, blade coating, die coating, gravure coating, and curtain coating. Moreover, you may make it laminate | stack an adhesive layer by apply | coating the said adhesive containing composition directly on the surface of a hard coat film, and making it dry.

  Although various release sheets can be used as the release sheet, the release sheet is typically composed of a base sheet having peelability on the surface. Examples of the base sheet include films such as polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, and polycarbonate resin, films in which fillers such as fillers are blended with these films, and synthetic paper. Moreover, paper base materials, such as glassine paper, clay coat paper, and quality paper, are mentioned.

In order to give the surface of the base sheet peelability, a release agent such as a thermosetting silicone resin or an ultraviolet curable silicone resin may be attached to the surface by coating or the like. The coating amount of the release agent, 0.03~3.0g / m ² is preferred. The release sheet is laminated with the surface having the release agent in contact with the pressure-sensitive adhesive layer.

〔Example〕
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

<Preparation of protective film>
<Production of Cellulose Ester Film CE1>
<Preparation of fine particle dispersion 1>
Silica fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.)
11 parts by mass Ethanol 89 parts by mass The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin to prepare a fine particle dispersion 1.

<Preparation of fine particle additive solution 1>
The fine particle dispersion 1 was slowly added to the dissolution tank containing methylene chloride with sufficient stirring. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution 1.
99 parts by mass of methylene chloride 5 parts by mass of fine particle dispersion 1

<Preparation of dope>
First, methylene chloride and ethanol were added to the pressure dissolution tank. Next, cellulose acetate was added to the pressurized dissolution tank containing the solvent while stirring. This was completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No. The main dope was prepared by filtration using 244.
Methylene chloride 340 parts by mass Ethanol 64 parts by mass Cellulose diacetate (average degree of acetyl group substitution 2.41, Mw 300,000)
100 parts by mass Polyester compound AP-16 6 parts by mass Sugar ester compound 1-3 6 parts by mass Particulate additive solution 1 1 part by mass Then, the main dope and each material are put into a sealed container so that the above ratio is obtained. The dope was prepared by dissolving with stirring.

<Film formation>
Then, using an endless belt casting apparatus, the dope was cast uniformly on a stainless steel belt support at a temperature of 33 ° C. and a width of 1500 mm. The temperature of the stainless steel belt was controlled at 30 ° C. Then, the solvent was evaporated until the residual solvent amount in the cast (cast) film reached 75% on the stainless steel belt, and then the web was peeled off from the stainless steel belt with a peeling tension of 130 N / m.

  The peeled web (cellulose ester film) was stretched 10% in the width direction using a tenter while applying heat at 160 ° C. The residual solvent at the start of stretching was 15%. Next, drying was terminated while the drying zone was conveyed by a number of rolls. The drying temperature was 130 ° C. and the transport tension was 100 N / m. After drying, the film was slit to a width of 1.5 m, a knurling process having a width of 10 mm and a height of 10 μm was applied to both ends of the film, wound into a roll, and a cellulose ester film CE1 having a dry film thickness of 30 μm was obtained. The winding length of the cellulose ester film CE1 was 5200 m.

  When the in-plane retardation value Ro and the thickness direction retardation value Rth of the cellulose ester film CE1 were measured using an automatic birefringence meter Axoscan (Axo Scan Mueller Matrix Polarimeter: manufactured by Axometrics), Ro = 1 nm. Rth = 4 nm.

<Production of cellulose ester films CE2 to CE3>
Cellulose ester films CE2 to CE3 were formed in the same manner as the cellulose ester film CE1, except that the film thickness was changed to the film thickness shown in Table 1.

<Preparation of cellulose ester film CE4>
A cellulose ester film CE4 having a film thickness of 13 μm was prepared by additionally stretching a commercially available cellulose ester film (KC2CT1, film thickness 20 μm) manufactured by Konica Minolta Co., Ltd.

<Film formation of COP film 1>
<Synthesis of polymer resin having alicyclic structure>
Under an ethylene atmosphere, toluene and a phenylnorbornene-toluene solution were put in an autoclave having a volume of 1.6 l so that the phenylnorbornene concentration was 20 mol / l and the total liquid volume was 640 ml. Methylaluminoxane (manufactured by Albemarle, MAO 20% toluene solution) was added with 5.88 mmol and methylene (cyclopentadienyl) (tetramethylcyclopentadienyl) zirconium dichloride 1.5 μmol based on Al, ethylene was introduced and pressure was added. Was kept at 0.2 MPa for 60 minutes at 80 ° C.

  After completion of the reaction, ethylene was depressurized while allowing to cool, and the system was replaced with nitrogen. Thereafter, 3.0 g of silica (made by Fuji Silysia Co., grade: G-3 particle size: 50 μm) whose adsorbed water content was adjusted to 10% by mass was added and reacted for 1 hour. The reaction solution was placed in a pressure filter (Advantech Toyo Co., Ltd., model KST-90-UH) set with filter paper (5C, 90 mm) and Celite (Wako Pure Chemical Industries, Ltd.), and pressure filtered with nitrogen for polymerization. The liquid was collected. The polymerization solution was dropped dropwise in 5 times amount of acetone and deposited to obtain a polymer resin COP1 having an alicyclic structure. COP1 had a weight average molecular weight of 142,000 and a glass transition temperature of 140 ° C.

  The polymer resin COP1 having an alicyclic structure synthesized above is dried for 2 hours at 70 ° C. using a hot air dryer in which air is circulated to remove moisture, and then resin melt kneaded with a 65 mmφ screw A COP film having a film thickness of 100 μm was extruded using a T-die film melt extrusion molding machine (T-die width 500 mm) having a machine under molding conditions of a molten resin temperature of 240 ° C. and a T-die temperature of 240 ° C.

  Next, the peeled COP film was stretched 90% in the width direction using a tenter while applying heat at 200 ° C. Next, drying was completed while the drying zone was conveyed by a number of rollers. The drying temperature was 130 ° C. and the transport tension was 100 N / m. After drying, it was slit to a width of 1.5 m, a knurling process having a width of 10 mm and a height of 10 μm was applied to both ends of the film, wound into a roll, and a COP film 1 having a dry film thickness of 8 μm was obtained. The winding length of the COP film 1 was 5000 m.

  When the in-plane retardation value Ro and the thickness direction retardation value Rth of the COP film 1 were measured using an automatic birefringence meter Axoscan (Axo Scan Mueller Matrix Polarimeter: manufactured by Axometrics), Ro = 0 nm, Rth = 2 nm.

<Film formation of COP film 2>
COP film 2 was produced in the same manner as cellulose ester film CE1 except that Arton (G7810) manufactured by JSR Corporation was used and polyester compound AP-15 was added as an additive.

  When the in-plane retardation value Ro and the thickness direction retardation value Rth of the COP film 2 were measured using an automatic birefringence meter Axoscan (Axo Scan Mueller Matrix Polarimeter: manufactured by Axometrics), Ro = 2 nm, Rth = 3 nm.

<Measurement of viscosity>
The viscosity of each optical film (cellulose ester films CE1 to CE4, COP films 1 and 2) prepared as described above was measured using a viscoelasticity measuring device (DMA7100) manufactured by Hitachi High-Tech Science. That is, using the above apparatus, the minimum value of Log (tan δ) in the temperature range of −40 ° C. to 90 ° C. was measured for each optical film.

<Production of polarizer>
A Kuraray PVA film (thickness 20 μm) was stretched and dyed at a draw ratio of 2 times in a dyeing bath (35 ° C.) containing iodine concentration of 0.3 wt% and KI, followed by a crosslinking bath containing boric acid ( The film was stretched 2.5 times at 50 ° C. and stretched at a total stretch ratio of 5 times (thickness 7 μm). Then, the said PVA film was dried with 60 degreeC drying machine, and the polarizer 1 was produced. A polarizer 2 having a thickness of 5 μm was also produced in the same manner as described above except that the film was stretched at a total stretching ratio of 5.7 times.

<Preparation of polarizing plate>
With the combination of the protective film and the counter film shown in Table 1, these were bonded to a polarizer using an adhesive to produce polarizing plates 1 to 6.

<Evaluation>
(crack)
The polarizing plates 1 to 6 produced above were punched into a circular shape (an irregular shape other than a rectangle), and then whether or not the polarizing plate had cracks was observed with a microscope. Moreover, after changing the temperature of the polarizing plates 1-6 produced above between -30 degreeC and 80 degreeC and repeating this temperature change 200 times, it is examined with a microscope whether the polarizing plate has a crack. Observed. And it evaluated about the crack based on the following evaluation criteria.
"Evaluation criteria"
○: Almost no cracks were observed both at the time of punching and at the time of temperature change.
X: Generation of cracks was observed in at least one of punching and temperature change.

(Luminance)
<Production of IPS liquid crystal display device>
An IPS cell having a striped pixel electrode and a striped common electrode was manufactured by the manufacturing method shown in FIG. Thereafter, the polarizing plates 1 to 6 shown in Table 1 were adhered to the viewing side and the backlight side of the IPS cell with an adhesive to produce IPS liquid crystal display devices 1 to 6.

Next, using a spectral radiance meter CS2000 manufactured by Konica Minolta Co., Ltd., the luminance of the IPS type liquid crystal display device produced above was measured and evaluated based on the following criteria.
"Evaluation criteria"
○: The luminance value is greater than or equal to the reference value.
Δ: The luminance value is 90% or more of the reference value and less than the reference value.
X: The luminance value is less than 90% of the reference value.

  Table 1 shows the result of evaluation for the polarizing plates 1 to 6, and Table 2 shows the result of evaluation for the liquid crystal display devices 1 to 6.

  From the results in Table 1, the polarizing plates 1 to 4 have no cracks, whereas the polarizing plates 5 and 6 have cracks. This is because, unlike the polarizing plates 5 and 6, the polarizing plates 1 to 4 are thin with a thickness of 20 μm or more and 65 μm or less, so that cracks hardly occur due to punching, and the value of Log (tan δ) is low. This is considered to be because cracks are less likely to occur due to the temperature change because the change in viscosity due to the temperature change is small.

  Further, from Table 2, all of the liquid crystal display devices 1 to 6 have good luminance evaluation results. This is presumably because the IPS cell has a stripe-shaped pixel electrode and a stripe-shaped common electrode, thereby realizing an IPS cell with high transmittance.

  The deformed display device of this embodiment described above can be expressed as follows.

1. The display screen is a deformed display device having a shape different from a rectangle and a square,
An IPS cell, and each polarizing plate sandwiching the IPS cell from both sides,
The IPS cell is
A pixel electrode positioned in a stripe shape within a display area of one pixel;
A stripe-shaped common electrode arranged alternately with the pixel electrode;
Each polarizing plate has a thickness of 20 μm or more and 65 μm or less,
Each polarizing plate is
It has a polarizer and each optical film that sandwiches the polarizer from both sides,
When the loss tangent indicating the ratio between the loss elastic modulus and the storage elastic modulus is tan δ,
Each of the optical films of the polarizing plates has a Log (tan δ) value of −1.8 or more between −40 ° C. and 100 ° C.

  2. 2. The deformed display device according to 1 above, wherein each optical film of each polarizing plate contains a cellulose ester resin.

  3. 3. The odd-shaped display device according to 1 or 2, wherein each optical film of each polarizing plate contains terminal-capped polyester as a plasticizer.

4). The IPS cell is
A passivation film positioned in stripes within a display area of one pixel;
An underlayer that supports the passivation film;
The pixel electrode is located on the passivation film;
4. The odd-shaped display device according to any one of 1 to 3, wherein the common electrode is located on the base layer and between the adjacent passivation films.

  The present invention can be used for a display device having a deformed display screen.

1 Liquid crystal display device (Atypical display device)
DESCRIPTION OF SYMBOLS 1a Display screen 2 IPS cell 3 Polarizing plate 4 Polarizing plate 11 Polarizer 12 Protective film (optical film)
13 Opposite film (optical film)
21 Polarizer 22 Protective film (optical film)
23 Opposite film (optical film)
107 Organic passivation film (underlayer)
108 common electrode 109 passivation film 110 pixel electrode P display area

Claims (4)

The display screen is a deformed display device having a shape different from a rectangle and a square,
An IPS cell, and each polarizing plate sandwiching the IPS cell from both sides,
The IPS cell is
A pixel electrode positioned in a stripe shape within a display area of one pixel;
A stripe-shaped common electrode arranged alternately with the pixel electrode;
Each polarizing plate has a thickness of 20 μm or more and 65 μm or less,
Each polarizing plate is
It has a polarizer and each optical film that sandwiches the polarizer from both sides,
When the loss tangent indicating the ratio between the loss elastic modulus and the storage elastic modulus is tan δ,
In each optical film of each polarizing plate, a variant display device in which a value of Log (tan δ) between −40 ° C. and 100 ° C. is −1.8 or more.   The deformed display device according to claim 1, wherein each optical film of each polarizing plate includes a cellulose ester-based resin.   3. The deformed display device according to claim 1, wherein each optical film of each polarizing plate includes a terminal-capped polyester as a plasticizer. The IPS cell is
A passivation film positioned in stripes within a display area of one pixel;
An underlayer that supports the passivation film;
The pixel electrode is located on the passivation film;
4. The odd-shaped display device according to claim 1, wherein the common electrode is located on the base layer and between the adjacent passivation films. 5.

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