JP5652211B2 - Manufacturing method of λ / 4 plate with hard coat, manufacturing method of polarizing plate using λ / 4 plate with hard coat, and manufacturing method of liquid crystal display device - Google Patents

Description

The present invention relates to a method for producing a hard coat with lambda / 4 plate, a method of manufacturing a polarizing plate production method and a liquid crystal display device using the hard with coat lambda / 4 plate. More specifically, the small streaks that affect visibility, related to the production method and the like with no hard coat with a λ / 4 plate uneven.

  In recent years, the λ / 4 plate with a hard coat obtained by laminating a hard coat layer on a λ / 4 plate having a function of converting linearly polarized light having a specific wavelength into circularly polarized light has been used in fields such as stereoscopic (3D) image display devices and touch panels. Demand is coming out.

  In this case, since the λ / 4 plate is disposed on the outermost surface of the display or glasses for viewing stereoscopic images, in order to provide performance such as scratch resistance, antifouling property, antiglare property, and antireflection, It is preferable to use as 4 plates.

  A stretched polycarbonate film or a stretched norbornene polymer film is known as a λ / 4 plate. When a λ / 4 plate made of a stretched polycarbonate film is used on the viewing side of a liquid crystal display of a stereoscopic image display device, a large light of the polycarbonate film is obtained. There was a serious problem that unevenness of the in-plane retardation Ro derived from the elastic modulus occurred.

  In addition, when a stretched norbornene-based polymer film is used on the viewing side of the liquid crystal display of a stereoscopic image display device, there is a serious problem that cracking or dissolution occurs when sebum or detergent touches the norbornene-based film. there were.

  On the other hand, stretched cellulose triacetate films and stretched cellulose acetate propionate films are known as λ / 4 plates that can be used for large displays and have excellent durability.

  Since the stretched cellulose triacetate film and the stretched cellulose acetate propionate film have a small photoelastic coefficient, the above-mentioned Ro unevenness hardly occurs, and even when touched by sebum or detergent, cracks are not generated or dissolved.

  However, the cellulose triacetate film is not suitable for a retardation film because it is originally isotropic and has a weak birefringence. Therefore, there are λ / 4 plates in which a so-called retardation increasing agent is added to cellulose triacetate resin, and λ / 4 plates using a mixed fatty acid ester of cellulose such as cellulose acetate propionate having higher birefringence than cellulose triacetate resin. Has been studied. (For example, refer to Patent Documents 1 and 2).

  However, in the λ / 4 plate to which the above-described retardation increasing agent is added, in order to further reduce the thickness of the λ / 4 plate, it is necessary to increase the amount of addition of the retardation increasing agent per film thickness. A problem called bleed-out in which the additive precipitates may occur.

  In addition, the λ / 4 plate using the mixed fatty acid ester film of cellulose has higher birefringence than the cellulose triacetate, but the synthesis difficulty of the mixed fatty acid ester resin of the cellulose itself is high and the cost of the polarizing plate is reduced. Had a problem.

  Accordingly, a λ / 4 plate having a low-cost cellulose ester that can obtain a desired retardation without increasing the amount of addition of the retardation increasing agent and that does not cause bleed out has been expected.

  The present inventors have studied the application of a cellulose acetate film having an acetyl group substitution degree of 2.0 to 2.5, which is advantageous in terms of cost and has high birefringence by stretching treatment, and certainly exhibits retardation. Although it is excellent in properties, the occurrence of fine streaks and unevenness is observed by the stretching process, and when a hard coat layer is applied, the fine streaks and unevenness are enlarged due to shrinkage accompanying the hardening of the hard coat layer. Therefore, it has been found that the problem of crosstalk, which is not a problem in the conventional display device, occurs particularly in the stereoscopic (3D) image display device.

  In particular, the problem of crosstalk due to the fine streaks and unevenness is that a λ / 4 plate with a hard coat and a polarizing film are laminated by roll-to-roll to easily obtain a long circularly polarizing plate. It has been found that this phenomenon occurs remarkably when the plate is stretched in a 45 ° oblique direction with respect to the width direction.

  Conventionally, in order to improve the optical properties of optical films including λ / 4 plates (in-plane retardation Ro unevenness, dimensional change), before or after stretching the film, water vapor is blown in another process or impregnated with moisture. Methods have been studied (Patent Documents 3 to 5).

  However, even with the above technique, the fine streaks and unevenness of the λ / 4 plate with a hard coat cannot be eliminated, and the hard coat containing a cellulose ester that does not affect the visibility such as crosstalk of the stereoscopic image display device is provided. There was a problem in obtaining a λ / 4 plate.

International Publication No. 2000/65384 Pamphlet JP 2008-83307 A JP 2003-90915 A JP 2010-158787 A JP 2010-158788 A

Accordingly, an object of the present invention is to provide a method for producing a λ / 4 plate with a hard coat having no slight streak and unevenness that affects visibility, and a polarizing plate using the λ / 4 plate with a hard coat . there is provided a method of manufacturing a manufacturing method and a liquid crystal display device.

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

1. Λ containing a cellulose acylate having a total acyl substitution degree of 2.0 to 2.5 and a compound having a total average substitution degree represented by the following general formula (FA) in the range of 3.0 to 6.5 A method for producing a λ / 4 plate with a hard coat in which a hard coat layer is provided on the / 4 plate, wherein the λ / 4 plate is subjected to hot water immersion treatment or steam treatment , and continuously within 1 second to 5 minutes. A method for producing a λ / 4 plate with a hard coat, comprising applying a hard coat layer.

(Wherein R _{1 to} R ₈ each independently represents a substituted or unsubstituted alkylcarbonyl group or a substituted or unsubstituted arylcarbonyl group, and R _{1 to} R ₈ may be the same as each other) , May be different.)
2. 2. The method for producing a λ / 4 plate with a hard coat as described in 1 above, wherein the hard coat layer contains a hydrophilic actinic radiation curable resin.

  3. A long λ / 4 plate that is obliquely stretched so that the angle between the width direction and the slow axis in the plane of the λ / 4 plate is in the range of 40 to 50 °. 3. The method for producing a λ / 4 plate with a hard coat as described in 1 or 2 above.

  4). 4. The method for producing a λ / 4 plate with a hard coat according to any one of 1 to 3, wherein an antireflection layer having at least a low refractive index layer is provided on a surface of the hard coat layer.

5. The λ / 4 plate with a hard coat manufactured by the method for manufacturing a λ / 4 plate with a hard coat according to any one of the above 1 to 4 is bonded to at least one surface of a polarizer. Manufacturing method of polarizing plate.

6). 6. A method for producing a liquid crystal display device , wherein the polarizing plate produced by the method for producing a polarizing plate according to 5 is bonded to the viewing side of the liquid crystal cell.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of (lambda) / 4 board with a hard coat without a fine streak and nonuniformity affecting visibility can be provided, and manufacture of a polarizing plate using this (lambda) / 4 board with a hard coat A method and a manufacturing method of a liquid crystal display device can be provided.

It is a schematic diagram of the hot water tank which concerns on this invention. It is a schematic diagram of the hot water tank which has the shower nozzle which concerns on this invention. It is a schematic diagram of the water vapor treatment according to the present invention. It is a schematic diagram which shows the diagonal stretch by a tenter. It is a schematic diagram of a three-dimensional image display apparatus (system with one polarizing plate of glasses). It is a schematic diagram of a three-dimensional image display apparatus (system with two polarizing plates of glasses).

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

  The method for producing a λ / 4 plate with a hard coat of the present invention provides a λ / 4 plate with a hard coat having no fine streaks or unevenness affecting visibility, and at least a total acyl substitution degree of 2.0 to 2. Λ / 4 plate containing a cellulose acylate of 0.5 and a compound having a total average substitution degree represented by the general formula (FA) in the range of 3.0 to 6.5, In the step of providing a hard coat layer on the four plates, the hard coat layer is continuously applied after the λ / 4 plate is subjected to a hot water immersion treatment or a steam treatment.

  As described above, the cellulose acetate film having an acetyl group substitution degree of 2.0 to 2.5 is characterized by high birefringence expression by the stretching treatment, but slight stretching and unevenness are generated by the stretching treatment. The minute streaks and unevenness remain on the surface of the hard coat layer even when the hard coat layer is applied. Therefore, the refractive index near the surface of the hard coat layer is uneven, particularly in a stereoscopic (3D) image display device. It has been found that this is one of the causes of crosstalk, which has not been a problem with conventional display devices.

  In particular, it has also been found that the fine streaks and unevenness are prominent when the λ / 4 plate is stretched in a 45 ° oblique direction with respect to the width direction.

  According to the configuration of the present invention, a compound having a low average acyl substitution degree cellulose acylate having a large number of hydrophilic groups and a total average substitution degree represented by the general formula (FA) in the range of 3.0 to 6.5. Before coating the hard coat layer, the entire λ / 4 plate is smoothed by hot water immersion treatment or steam treatment, and the hard coat layer is continuously applied to form the hard coat layer. A λ / 4 plate with a hard coat without slight streaks and unevenness is produced by reducing the slippage caused by shrinkage during curing. Therefore, when the elapsed time from hot water immersion treatment or steam treatment to coating of the hard coat layer is long, for example, a long λ / 4 plate is rolled up after the hot water immersion treatment or steam treatment is performed. The effect of the present invention cannot be obtained in the case where the hard coat layer is applied again by rolling out from the roll.

  According to the study by the present inventors, a compound having a total average substitution degree represented by the general formula (FA) in the range of 3.0 to 6.5 is a total acyl substitution degree of 2.0 to 2. 5 is remarkably excellent in compatibility with the cellulose acylate, so that it can be contained in a relatively large amount. Even when the λ / 4 plate is stretched in a 45 ° oblique direction with respect to the width direction, Generation of minute streaks and unevenness can be effectively suppressed by the plasticizing effect. Moreover, since the hot water immersion treatment or the steam treatment according to the present invention has a high effect of stretching the cellulose molecules flexibly, it is possible to remarkably suppress the occurrence of minute streaks and unevenness due to curing shrinkage when a hard coat layer is applied. .

  Furthermore, it has also been found that the effect of the present invention is further enhanced when the curable resin constituting the hard coat layer is a hydrophilic active ray curable resin.

  Hereinafter, the present invention will be described in detail.

<Λ / 4 plate>
The λ / 4 plate according to the present invention has a function of converting linearly polarized light having a specific wavelength into circularly polarized light (or converting circularly polarized light into linearly polarized light). The λ / 4 plate is designed such that the in-plane retardation value Ro is about 1/4 with respect to a predetermined wavelength of light (usually in the visible light region).

  In the λ / 4 plate according to the present invention, the in-plane retardation Ro (590) measured at a wavelength of 590 nm is in the range of 110 to 170 nm.

  The λ / 4 plate according to the present invention is a retardation plate (resin film) having a retardation of approximately ¼ of the wavelength in the visible light wavelength range in order to obtain almost perfect circularly polarized light in the visible light wavelength range. ) Is preferable.

  The term “retardation of approximately ¼ in the wavelength range of visible light” means a retardation value represented by the following formula (i) measured at a wavelength of 450 nm, with a longer retardation at a wavelength of 400 to 700 nm. It is preferable that Ro (590) which is a retardation value measured at a certain Ro (450) and a wavelength of 590 nm satisfies 1 <Ro (590) / Ro (450) ≦ 1.6. Furthermore, in order to function effectively as a λ / 4 plate, Ro (450) is in the range of 100 to 125 nm, and Ro (550) which is a retardation value measured at a wavelength of 550 nm is in the range of 125 to 142 nm. More preferably, the retardation film is Ro (590) in the range of 130 to 152 nm.

Formula (i): Ro = (nx−ny) × d
In the formula, nx and ny are refractive indexes nx (also referred to as the maximum in-plane refractive index and refractive index in the slow axis direction) at 23 ° C./55% RH, 450 nm, 550 nm, and 590 nm, ny. (Refractive index in the direction perpendicular to the slow axis in the film plane), and d is the thickness (nm) of the film.

  Ro can be measured using an automatic birefringence meter. Using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments), Ro is calculated by birefringence measurement at each wavelength in an environment of 23 ° C. and 55% RH.

  A circularly polarizing plate is obtained by laminating so that the angle between the slow axis of the λ / 4 plate and the transmission axis of the polarizer is substantially 45 °. “Substantially 45 °” means 40 to 50 °. The angle between the slow axis in the plane of the λ / 4 plate and the transmission axis of the polarizer is preferably 41 to 49 °, more preferably 42 to 48 °, and 43 to 47 °. More preferably, it is most preferable that it is 44-46 degrees.

  The long λ in which the λ / 4 plate according to the present invention is obliquely stretched so that the angle between the width direction and the slow axis in the plane of the λ / 4 plate is in the range of 40 to 50 °. A / 4 plate is preferable because a long circularly polarizing plate can be easily obtained by laminating with a long polarizer having an absorption axis in the longitudinal direction with a roll to roll.

  The λ / 4 plate according to the present invention is a film containing a thermoplastic resin, and the thermoplastic resin used is a cellulose acylate resin. The cellulose acylate resin is preferable from the viewpoints of production, cost, ease of processing, transparency, uniformity, suitability for saponification, adhesiveness, and the like.

<Λ / 4 plate warm water immersion treatment, steam treatment>
The λ / 4 plate according to the present invention is characterized in that a hard coat layer is continuously applied after the λ / 4 plate is subjected to a hot water immersion treatment or a steam treatment.

(Hot water immersion treatment)
An example of the immersion method in warm water is shown in FIG. A λ / 4 plate fed out from a long λ / 4 plate roll manufactured by a method of manufacturing a λ / 4 plate, which will be described later, is immersed in a hot water tank while being conveyed by a roller. The hard coat layer is applied in the hard coat layer application step. Before the hard coat layer coating step, the λ / 4 plate may be drained or dried with hot air or the like, but the water content of the λ / 4 plate before the hard coat layer coating is 2 It is preferable to control in the range of -20 mass%. Controlling the moisture content within this range is preferable because the effects of the present invention can be obtained and the coating unevenness of the hard coat layer, etc., seen when the content exceeds 20% by mass is not induced. More preferably, it is 2.5-18 mass%, Most preferably, it is 3-16 mass%.

  In order to maintain the moisture content, a closed system may be used so as to keep constant temperature and humidity from the hot water tank to the hard coat layer coating step.

  The moisture content is the mass fraction (%) of water contained in the film. Actually, the moisture content (μg) indicated by the moisture meter is W, and the weighed sample amount is F (mg). (Mass%) = 0.1 × (W / F).

  As another example of the immersion method in warm water, warm water may be applied from a shower nozzle as shown in FIG.

  The hot water temperature is preferably 40 ° C. or higher and 100 ° C. or lower, more preferably 50 ° C. or higher and 95 ° C. or lower, and particularly preferably 60 ° C. or higher and 90 ° C. or lower. The immersion time is preferably from 5 seconds to 10 minutes, more preferably from 10 seconds to 8 minutes, and particularly preferably from 20 seconds to 6 minutes. Higher hot water temperature and longer time are convenient for obtaining the effects of the present invention. However, lower hot water temperature and shorter time may not deteriorate the flatness of the film, and control is made within these ranges. It is preferable.

  The warm water referred to in the present invention may be substantially water. Water substantially means that 60% by mass or more is made of water, and may contain an organic solvent, a plasticizer, a surfactant and the like in addition to water. A preferred organic solvent is a water-soluble organic solvent having 1 to 10 carbon atoms. However, more preferably 90% by mass or more is water, still more preferably 95% by mass or more is water, and most preferable is pure water.

  You may circulate by adding bubbling by nitrogen etc. in warm water, or adding the apparatus which filters warm water.

  The λ / 4 plate according to the present invention is continuously coated with a hard coat layer after being subjected to hot water immersion treatment, but the term “continuous” as used in the present invention refers to within 1 second to 5 minutes, more preferably productivity. In consideration, it means within 10 seconds to 3 minutes, more preferably within 15 seconds to 1 minute. In this case, it is preferable to coat the hard coat layer while maintaining the transport tension for transporting the λ / 4 plate in order to enhance the effect of the present invention.

(Steam treatment)
The steam treatment is preferably performed by installing a steam treatment chamber having a steam supply machine and capable of keeping temperature and humidity constant.

  FIG. 3 shows an example of a steam treatment chamber.

  The λ / 4 plate 5 according to the present invention is transported to the steam processing chamber 1, and the λ / 4 plate held and transported by the nip rolls 2, 2 ′ is sprayed with steam from the steam nozzle 3 onto the λ / 4 plate, After the treatment, excess water droplets are removed by the air knife 4 and conveyed to the hard coat layer coating step. The steam may be directly jetted onto the λ / 4 plate using the steam nozzle 3 or the like, and the steam is jetted in the steam treatment chamber so that the relative humidity is 60% RH or more and 100% RH or less. The λ / 4 plate may be steamed while being transported over a certain time.

In the present invention, it is preferable that the λ / 4 plate and the water vapor contact in an environment where the absolute humidity is 50 to 1000 g / m ² . Preferably, it is performed in an environment of 300 to 800 g / m ² . Absolute humidity is 611 g / ^{m 2} approximately at 80g ^/ m 2, 90 ℃ at 50g ^/ m 2, 50 ℃ at 40 ° C..

  The treatment time in the steam treatment chamber is preferably 5 seconds or more and 60 minutes or less. In consideration of productivity, it is more preferably 10 seconds or more and 5 minutes or less.

  In order to perform hot water immersion treatment and water vapor treatment according to the present invention at high speed, the surface of the λ / 4 plate is subjected to physical surface treatment such as plasma discharge treatment or corona discharge treatment, or chemical surface treatment using an alkali agent or the like. It is also preferable to increase wettability. The surface treatment is preferably performed only by chemical surface treatment or a combination of physical surface treatment and chemical surface treatment.

<Cellulose acylate film>
The λ / 4 plate according to the present invention contains cellulose acylate having a total acyl substitution degree of 2.0 to 2.5.

  Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by acylating part or all of these hydroxyl groups with an acyl group. The degree of acyl substitution means the ratio of acylation of the hydroxyl groups of cellulose located at the 2-position, 3-position and 6-position (100% acylation is substitution degree 1). In addition, the substitution degree of an acyl group is calculated | required by the method prescribed | regulated to ASTM-D817-96.

  It is more preferable that the total acyl substitution degree satisfies 2.1 to 2.45 from the viewpoint of the retardation development property by the stretching treatment.

  When the total acyl group substitution degree of cellulose acylate is less than 2.0, deterioration of film surface quality due to increase in dope viscosity, haze-up due to increase in stretching tension, and the like may occur. Further, when the total acyl substitution degree exceeds 2.5, it is difficult to obtain a necessary phase difference.

  The acyl group having 2 or more carbon atoms of cellulose acylate in the present invention may be an aliphatic group or an allyl group, and is not particularly limited. These are, for example, cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituted group. Preferred examples of these include acetyl group, propionyl group, butanoyl group, heptanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, isobutanoyl group Group, tert-butanoyl group, cyclohexanecarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like. Among these, an acetyl group, a propionyl group, a butanoyl group, a dodecanoyl group, an octadecanoyl group, a tert-butanoyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, a cinnamoyl group, and the like are more preferable, and an acetyl group is particularly preferable. A propionyl group and a butanoyl group (when the acyl group has 2 to 4 carbon atoms), and most preferably an acetyl group (when the cellulose acylate is cellulose acetate) are preferred.

  The degree of acetyl substitution here refers to the average value of the number of hydroxyl groups (hydroxyl groups) that are esterified (acetylated) among the three hydroxyl groups (hydroxyl groups) of each anhydroglucose that constitutes cellulose. A value in the range of 0 to 3 is shown.

  In the present invention, a portion not substituted with an acetyl group is usually present as a hydroxyl group (hydroxyl group). These can be synthesized by known methods.

  The number average molecular weight (Mn) of the cellulose acylate and cellulose acetate according to the present invention is preferred because the mechanical strength of the film from which a range of 30000-300000 is obtained is strong. Furthermore, the thing of 50000-200000 is used preferably.

  The ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of cellulose acylate and cellulose acetate is preferably 1.4 to 3.0.

  The weight average molecular weight Mw and the number average molecular weight Mn of cellulose acylate and cellulose acetate were measured using gel permeation chromatography (GPC).

  The measurement conditions are as follows.

Solvent: Methylene chloride Column: Shodex K806, K805, K803G (Used by connecting three Showa Denko Co., Ltd.)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation) Mw = 100000 to 500 calibration curves with 13 samples were used. Thirteen samples are used at approximately equal intervals.

  The cellulose as a raw material for cellulose acylate and cellulose acetate according to the present invention is not particularly limited, and examples thereof include cotton linter, wood pulp, and kenaf. In addition, cellulose acylate and cellulose acetate obtained from them can be mixed and used in an arbitrary ratio.

  In the acylation of cellulose, when an acid anhydride or acid chloride is used as an acylating agent, an organic acid such as acetic acid or methylene chloride is used as an organic solvent as a reaction solvent.

As the catalyst, when the acylating agent is an acid anhydride, a protic catalyst such as sulfuric acid is preferably used, and when the acylating agent is an acid chloride (for example, CH ₃ CH ₂ COCl), Basic compounds are used.

  In addition, a general method for industrially synthesizing mixed fatty acid esters of cellulose is a mixed organic acid containing cellulose containing fatty acids corresponding to acetyl groups and other acyl groups (acetic acid, propionic acid, valeric acid, etc.) or acid anhydrides thereof. This is a method of acylating with components.

  Specifically, it can be synthesized with reference to the method described in JP-A-10-45804.

<Compound represented by formula (FA)>
The λ / 4 plate according to the present invention is represented by cellulose acylate having a total acyl substitution degree of 2.0 to 2.5 and the following general formula (FA), and the total average substitution degree is 3.0 to 6.5. By containing the compound within the range of λ / 4 plate with a hard coat having no slight streaks or unevenness affecting the visibility by the hot water immersion treatment or the steam treatment according to the present invention. In the present invention, the compound represented by the general formula (FA) is also referred to as a sugar ester compound.

  The average substitution degree of the compound represented by the general formula (FA) according to the present invention is 3.0 to 6.5, in addition to preventing slight streaks and unevenness in the stretching treatment, it suppresses haze increase. It is also effective above. The average degree of substitution is more preferably in the range of 4.5 to 6.5.

In the present invention, the degree of substitution of the compound represented by the general formula (FA) represents the number substituted with a substituent other than hydrogen among the eight hydroxyl groups contained in the general formula (FA). among _R 1 to R ₈ of general formula (FA), it represents a number that contains a group other than hydrogen. Therefore, when all of R _{1 to} R ₈ are substituted with a substituent other than hydrogen, the degree of substitution is 8.0, which is the maximum value, and when R _{1 to} R ₈ are all hydrogen atoms, 0.0 It becomes.

  The compound having the structure represented by the general formula (FA) is difficult to synthesize a single kind of compound in which the number of hydroxyl groups and the number of OR groups are fixed. Since it is known that it becomes a compound in which several different components are mixed, it is appropriate to use the average substitution degree as the substitution degree of the general formula (FA) in the present invention. The average substitution degree can be measured from the area ratio of the chart showing the substitution degree distribution.

In General Formula (FA), R _{1 to} R ₈ represent a substituted or unsubstituted alkylcarbonyl group or a substituted or unsubstituted arylylcarbonyl group, and R _{1 to} R ₈ may be the same, May be different.

  Examples of the sugar as a raw material for synthesizing the sugar ester compound according to the present invention include the following, but the present invention is not limited thereto.

  Glucose, galactose, mannose, fructose, xylose or arabinose, lactose, sucrose, nystose, 1F-fructosyl nystose, stachyose, maltitol, lactitol, lactulose, cellobiose, maltose, cellotriose, maltotriose, raffinose or kestose .

  In addition, gentiobiose, gentiotriose, gentiotetraose, xylotriose, galactosyl sucrose, and the like are also included.

  There is no restriction | limiting in particular as monocarboxylic acid used at the time of the synthesis | combination of the sugar ester compound based on this invention, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. The carboxylic acid used may be one type or a mixture of two or more types.

  Examples of preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, Saturation of lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, mellicic acid, and laxaric acid Examples thereof include unsaturated fatty acids such as fatty acids, undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and octenoic acid.

  Examples of preferred alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, or derivatives thereof.

  Examples of preferable aromatic monocarboxylic acids include aromatic monocarboxylic acids having 1 to 5 alkyl groups or alkoxy groups introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, cinnamic acid, benzylic acid, An aromatic monocarboxylic acid having two or more benzene rings such as biphenyl carboxylic acid, naphthalene carboxylic acid, tetralin carboxylic acid, or a derivative thereof can be exemplified, and benzoic acid is particularly preferable.

Some specific examples are shown below, but these are cases where R _{1 to} R ₈ are all the same substituent R, and the present invention is not limited thereto.

  The sugar ester compound according to the present invention can be produced by reacting a sugar ester with an acylating agent (also referred to as an esterifying agent, for example, an acid halide of acetyl chloride, an anhydride such as acetic anhydride). Yes, the distribution of the degree of substitution is made by adjusting the amount of acylating agent, the timing of addition, and the esterification reaction time, but it is a mixture of sugar ester compounds with different degrees of substitution or purely isolated compounds with different degrees of substitution. Can be used to adjust components having a target average substitution degree and a substitution degree of 4 or less.

  (Synthesis Example: Synthesis of Compound According to the Present Invention)

  Four-headed Kolben equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen gas inlet tube were charged with 34.2 g (0.1 mol) of sucrose, 135.6 g (0.6 mol) of benzoic anhydride, 284. 8 g (3.6 mol) was charged, the temperature was raised while bubbling nitrogen gas through a nitrogen gas inlet tube with stirring, and an esterification reaction was performed at 70 ° C. for 5 hours.

Next, the inside of the Kolben was depressurized to 4 × 10 ² Pa or less, and after excess pyridine was distilled off at 60 ° C., the inside of the Kolben was depressurized to 1.3 × 10 Pa or less and the temperature was raised to 120 ° C. Most of the acid and benzoic acid formed were distilled off. Then, 1 L of toluene and 300 g of a 0.5% by mass aqueous sodium carbonate solution were added, and the mixture was stirred at 50 ° C. for 30 minutes and then allowed to stand to separate a toluene layer. Finally, 100 g of water is added to the collected toluene layer, and after washing with water at room temperature for 30 minutes, the toluene layer is separated, and toluene is distilled off at 60 ° C. under reduced pressure (4 × 10 ² Pa or less). The sugar ester compound 1 which is a mixture of A-1, A-2, A-3, A-4, A-5, etc. was obtained.

  When the obtained mixture was analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS), A-1 was 1.2% by mass, A-2 was 13.2% by mass, and A-3 was 14.2% by mass. %, A-4 was 35.4% by mass, A-5 and the like were 40.0% by mass. The average degree of substitution was 5.2.

  Similarly, 158.2 g (0.7 mol) of benzoic anhydride, 146.9 g (0.65 mol), and 124.3 g (0.55 mol) were reacted with equimolar pyridine, and the results shown in Table 1 were obtained. A sugar ester of such ingredients was obtained.

  Next, a part of the obtained mixture is purified by column chromatography using silica gel to obtain 100% pure A-1, A-2, A-3, A-4, A-5, etc., respectively. Obtained.

  A-5 or the like means a mixture of all components having a substitution degree of 4 or less, that is, compounds having substitution degrees of 4, 3, 2, 1. The average substitution degree was calculated with A-5 and the like being the substitution degree 4.

In the present invention, the average degree of substitution was adjusted by combining and adding sugar esters close to the desired degree of average substitution, isolated A-1 to A-5, and the like by the method prepared here. <Measurement conditions for HPLC-MS>
1) LC section Device: JASCO CO., LTD. Column oven (JASCO CO-965), detector (JASCO UV-970-240 nm), pump (JASCO PU-980), degasser (JASCO DG-980-50)
Column: Inertsil ODS-3 Particle size 5 μm 4.6 × 250 mm (manufactured by GL Sciences Inc.)
Column temperature: 40 ° C
Flow rate: 1 ml / min
Mobile phase: THF (1% acetic acid): H2O (50:50)
Injection volume: 3 μl
2) MS unit Device: LCQ DECA (manufactured by Thermo Quest Co., Ltd.)
Ionization method: Electrospray ionization (ESI) method Spray Voltage: 5 kV
Capillary temperature: 180 ° C
Vaporizer temperature: 450 ° C
<Other plasticizers>
The λ / 4 plate according to the present invention preferably contains a plasticizer other than the above-mentioned compounds, and many compounds generally known as plasticizers can be usefully used.

  The plasticizer is not particularly limited, but is preferably a polycarboxylic acid ester plasticizer, a glycolate plasticizer, a phthalate ester plasticizer, a fatty acid ester plasticizer, a polyhydric alcohol ester plasticizer, or an ester plasticizer. Agent, acrylic plasticizer and the like.

  Of these, when two or more plasticizers are used, at least one plasticizer is preferably a polyhydric alcohol ester plasticizer.

  The polyhydric alcohol ester plasticizer is a plasticizer comprising an ester of a dihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably it is a 2-20 valent aliphatic polyhydric alcohol ester.

  The polyhydric alcohol preferably used in the present invention is represented by the following general formula (a).

Formula _{(a) R 11 - (OH} ) n
R ₁₁ represents an n-valent organic group, n represents a positive integer of 2 or more, and the OH group represents an alcoholic and / or phenolic hydroxyl group (hydroxyl group).

  Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these.

  Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol and the like.

  In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

  There is no restriction | limiting in particular as monocarboxylic acid used for polyhydric alcohol ester, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.

  Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1-20, and particularly preferably 1-10. When acetic acid is contained, compatibility with the cellulose ester resin is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

  Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.

  Examples of preferred alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, or derivatives thereof.

  Examples of preferred aromatic monocarboxylic acids include those in which 1 to 3 alkoxy groups such as an alkyl group, a methoxy group or an ethoxy group are introduced into the benzene ring of benzoic acid such as benzoic acid or toluic acid, biphenylcarboxylic acid, Examples thereof include aromatic monocarboxylic acids having two or more benzene rings such as naphthalenecarboxylic acid and tetralincarboxylic acid, or derivatives thereof. Benzoic acid is particularly preferable.

  The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably 300 to 1500, and more preferably 350 to 750. A larger molecular weight is preferable because it is less likely to volatilize, and a smaller one is preferable in terms of moisture permeability and compatibility with the cellulose ester resin.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.

  Below, the specific compound of a polyhydric alcohol ester is illustrated.

  The glycolate plasticizer is not particularly limited, but alkylphthalylalkyl glycolates can be preferably used.

  Examples of alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl Glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl glycol Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate, octyl phthalate Ethyl glycolate, and the like.

  Examples of the phthalate ester plasticizer include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, and dicyclohexyl terephthalate.

  Examples of the citrate plasticizer include acetyl trimethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate.

  Examples of fatty acid ester plasticizers include butyl oleate, methylacetyl ricinoleate, and dibutyl sebacate.

  The polyvalent carboxylic acid ester compound is composed of an ester of divalent or higher, preferably divalent to 20 valent polyvalent carboxylic acid and alcohol. The aliphatic polyvalent carboxylic acid is preferably 2 to 20 valent, and in the case of an aromatic polyvalent carboxylic acid or an alicyclic polyvalent carboxylic acid, it is preferably 3 to 20 valent.

  The polyvalent carboxylic acid is represented by the following general formula (b).

Formula (b) R ₁₂ (COOH) _m1 (OH) _n1
In the formula, R ₁₂ is an (m1 + n1) -valent organic group, m1 is a positive integer of 2 or more, n1 is an integer of 0 or more, a COOH group is a carboxyl group, an OH group is an alcoholic or phenolic hydroxyl group (hydroxyl group). Represent.

  Examples of preferred polyvalent carboxylic acids include the following, but the present invention is not limited to these.

  Trivalent or higher aromatic polyvalent carboxylic acids such as trimellitic acid, trimesic acid, pyromellitic acid or derivatives thereof, succinic acid, adipic acid, azelaic acid, sebacic acid, oxalic acid, fumaric acid, maleic acid, tetrahydrophthal An aliphatic polyvalent carboxylic acid such as an acid, an oxypolyvalent carboxylic acid such as tartaric acid, tartronic acid, malic acid and citric acid can be preferably used. In particular, it is preferable to use an oxypolycarboxylic acid from the viewpoint of improving retention.

  There is no restriction | limiting in particular as alcohol used for the polyhydric carboxylic acid ester compound which can be used for this invention, Well-known alcohol and phenols can be used.

  For example, an aliphatic saturated alcohol or aliphatic unsaturated alcohol having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. It is more preferable that it is C1-C20, and it is especially preferable that it is C1-C10.

  In addition, alicyclic alcohols such as cyclopentanol and cyclohexanol or derivatives thereof, aromatic alcohols such as benzyl alcohol and cinnamyl alcohol, or derivatives thereof can also be preferably used.

  When an oxypolycarboxylic acid is used as the polycarboxylic acid, the alcoholic or phenolic hydroxyl group (hydroxyl group) of the oxypolycarboxylic acid may be esterified with a monocarboxylic acid. Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. It is more preferable that it is C1-C20, and it is especially preferable that it is C1-C10.

  Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.

  Examples of preferred alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, or derivatives thereof.

  Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenyl carboxylic acid, naphthalene carboxylic acid, and tetralin carboxylic acid. The aromatic monocarboxylic acid which has, or those derivatives can be mentioned. Particularly preferred are acetic acid, propionic acid, and benzoic acid.

  The molecular weight of the polyvalent carboxylic acid ester compound is not particularly limited, but is preferably in the range of 300 to 1000, and more preferably in the range of 350 to 750. The larger one is preferable in terms of improvement in retention, and the smaller one is preferable in terms of moisture permeability and compatibility with the cellulose ester resin.

  The alcohol used for the polyvalent carboxylic acid ester that can be used in the present invention may be one kind or a mixture of two or more kinds.

  The acid value of the polyvalent carboxylic acid ester compound that can be used in the present invention is preferably 1 mgKOH / g or less, and more preferably 0.2 mgKOH / g or less. Setting the acid value in the above range is preferable because the environmental fluctuation of the retardation is also suppressed.

  In addition, an acid value means the milligram number of potassium hydroxide required in order to neutralize the acid (carboxyl group which exists in a sample) contained in 1g of samples. The acid value is measured according to JIS K0070.

<Ultraviolet absorber>
In the case where the λ / 4 plate according to the present invention is disposed on the viewing side of the display device, it is preferable to include an ultraviolet absorber from the viewpoint of improving light resistance.

  Examples of ultraviolet absorbers that can be used include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, triazine compounds, and the like. A benzotriazole-based compound with little coloring is preferable. Further, ultraviolet absorbers described in JP-A-10-182621, JP-A-8-337574, JP-A-2001-72782, JP-A-6-148430, JP-A-2002-31715, JP-A-2002-169020, 2002-2002. Polymer ultraviolet absorbers described in 47357, 2002-363420, and 2003-113317 are also preferably used. As an ultraviolet absorber, from the viewpoint of preventing the deterioration of polarizers and liquid crystals, it is excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less, and from the viewpoint of liquid crystal display properties, the absorption of visible light having a wavelength of 400 nm or more is small. Is preferred.

  Specific examples of UV absorbers useful in the present invention 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-chlorobenzotriazole, 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- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5 -Chloro-2H-benzotriazol-2-yl) phenyl] propionate and the like can be mentioned, but not limited thereto. As commercially available products, TINUVIN 109, TINUVIN 171, TINUVIN 326, and TINUVIN 928 (all manufactured by BASF Japan) can be preferably used. An example of the polymeric ultraviolet absorber is a reactive ultraviolet absorber RUVA-93 manufactured by Otsuka Chemical Co., Ltd.

  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 is not limited thereto.

  The ultraviolet absorber described above preferably used in the present invention is preferably a benzotriazole-based ultraviolet absorber or a benzophenone-based ultraviolet absorber, which has high transparency and is excellent in the effect of preventing the deterioration of the polarizing plate and the liquid crystal element, and unnecessary coloring. A benzotriazole-based ultraviolet absorber with a lower content is particularly preferably used.

  The ultraviolet absorber can be added to the dope without limitation as long as it dissolves the ultraviolet absorber in the dope. In the present invention, the ultraviolet absorber is cellulose such as methylene chloride, methyl acetate, dioxolane and the like. Dope by dissolving in a good solvent for the ester, or a mixed solvent of a good solvent and a poor solvent such as a lower aliphatic alcohol (methanol, ethanol, propanol, butanol, etc.) and adding it to the cellulose ester solution as an ultraviolet absorber solution Is preferred. In this case, it is preferable to make the dope solvent composition and the solvent composition of the ultraviolet absorber solution the same or as close as possible.

<Retardation adjuster>
The λ / 4 plate according to the present invention preferably contains a retardation developer from the viewpoint of suppressing the occurrence of fine streaks and unevenness due to excessive stretching.

  In the present invention, in order to express retardation, a disk-shaped or rod-shaped compound can be mentioned. As the discotic compound or rod-shaped compound, a compound having at least two aromatic rings can be preferably used as a retardation developer.

  The discotic retardation developer is preferably used in a range of 0.05 to 20 parts by mass, and in a range of 1.0 to 15 parts by mass, with respect to 100 parts by mass of the polymer component containing the cellulose acylate. It is more preferable to use, and it is still more preferable to use in the range of 3.0-10 mass parts. The addition amount of the retardation developer composed of the rod-like compound is preferably 0.1 to 30 parts by mass, and preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymer component containing cellulose acylate. Further preferred.

  Since the discotic compound is superior to the rod-shaped compound in terms of retardation development in the thickness direction, it is preferably used particularly when a large retardation in the thickness direction is required. Two or more types of retardation developing agents may be used in combination.

  The retardation developer preferably has maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

  First, the discotic compound will be described. As the discotic compound, a compound having at least two aromatic rings can be used.

  In the present specification, the “aromatic ring” includes an aromatic hetero ring in addition to an aromatic hydrocarbon ring.

  The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).

  The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.

  As the aromatic ring, a benzene ring, a condensed benzene ring, and biphenyls are preferable. In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, compounds disclosed in JP-A No. 2001-166144 are preferably used.

  The number of carbon atoms in the aromatic ring of the retardation developer is preferably 2-20, more preferably 2-12, further preferably 2-8, and 2-6. Most preferred.

  The bonding relationship between two aromatic rings can be classified into (a) when a condensed ring is formed, (b) when directly linked by a single bond, and (c) when linked via a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c).

  Examples of the condensed ring (a condensed ring of two or more aromatic rings) include an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, an acenaphthylene ring, a biphenylene ring, a naphthacene ring, Pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline Ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring and thiant It includes emissions ring. Naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred.

  The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded with two or more single bonds to form an aliphatic ring or a non-aromatic heterocyclic ring between the two aromatic rings.

The linking group in (c) is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenylene group, an alkynylene group, —CO—, —O—, —NH—, —S—, or a combination thereof. Examples of linking groups composed of combinations are shown below. In addition, the relationship between the left and right in the following examples of the linking group may be reversed.
c1: -CO-O-
c2: —CO—NH—
c3: -alkylene-O-
c4: —NH—CO—NH—
c5: —NH—CO—O—
c6: —O—CO—O—
c7: -O-alkylene-O-
c8: -CO-alkenylene-
c9: -CO-alkenylene-NH-
c10: -CO-alkenylene-O-
c11: -alkylene-CO-O-alkylene-O-CO-alkylene-
c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-
c13: -O-CO-alkylene-CO-O-
c14: -NH-CO-alkenylene-
c15: -O-CO-alkenylene-
The aromatic ring and the linking group may have a substituent.

  Examples of substituents include halogen atoms (F, Cl, Br, I), hydroxyl groups, carboxyl groups, cyano groups, amino groups, nitro groups, sulfo groups, carbamoyl groups, sulfamoyl groups, ureido groups, alkyl groups, alkenyls. Group, alkynyl group, aliphatic acyl group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group An aliphatic substituted carbamoyl group, an aliphatic substituted sulfamoyl group, an aliphatic substituted ureido group, and a non-aromatic heterocyclic group.

  It is preferable that the alkyl group has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is particularly preferable. The alkyl group may further have a substituent (for example, a hydroxy group, a carboxy group, an alkoxy group, an alkyl-substituted amino group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl, and 2- Each group of a diethylaminoethyl group is included.

  The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is particularly preferable. The alkenyl group may further have a substituent. Examples of the alkenyl group include a vinyl group, an allyl group, and a 1-hexenyl group.

  The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is particularly preferable. The alkynyl group may further have a substituent. Examples of the alkynyl group include ethynyl group, 1-butynyl group and 1-hexynyl group.

  The number of carbon atoms in the aliphatic acyl group is preferably 1-10. Examples of the aliphatic acyl group include an acetyl group, a propanoyl group, and a butanoyl group.

  The number of carbon atoms in the aliphatic acyloxy group is preferably 1-10. Examples of the aliphatic acyloxy group include an acetoxy group.

  The number of carbon atoms of the alkoxy group is preferably 1-8. The alkoxy group may further have a substituent (for example, an alkoxy group). Examples of the alkoxy group (including a substituted alkoxy group) include a methoxy group, an ethoxy group, a butoxy group, and a methoxyethoxy group.

  The number of carbon atoms of the alkoxycarbonyl group is preferably 2-10. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

  The number of carbon atoms of the alkoxycarbonylamino group is preferably 2-10. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group.

  The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an octylthio group.

  The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group.

  The number of carbon atoms in the aliphatic amide group is preferably 1-10. Examples of the aliphatic amide group include acetamide.

  The number of carbon atoms of the aliphatic sulfonamide group is preferably 1-8. Examples of the aliphatic sulfonamido group include a methanesulfonamido group, a butanesulfonamido group, and an n-octanesulfonamido group.

  The number of carbon atoms of the aliphatic substituted amino group is preferably 1-10. Examples of the aliphatic substituted amino group include a dimethylamino group, a diethylamino group, and a 2-carboxyethylamino group.

  The number of carbon atoms in the aliphatic substituted carbamoyl group is preferably 2-10. Examples of the aliphatic substituted carbamoyl group include a methylcarbamoyl group and a diethylcarbamoyl group.

  The number of carbon atoms in the aliphatic substituted sulfamoyl group is preferably 1-8. Examples of the aliphatic substituted sulfamoyl group include a methylsulfamoyl group and a diethylsulfamoyl group.

  The number of carbon atoms in the aliphatic substituted ureido group is preferably 2-10. Examples of the aliphatic substituted ureido group include a methylureido group.

  Examples of the non-aromatic heterocyclic group include a piperidino group and a morpholino group.

  The molecular weight of the retardation developer is preferably 300 to 800.

  As the discotic compound, a triazine compound represented by the following general formula (I) is preferably used.

In the above general formula (I):
R ²⁰¹ each independently represents an aromatic ring or a heterocyclic ring having a substituent in at least one of the ortho, meta and para positions.

X ²⁰¹ each independently represents a single bond or —NR ²⁰² —. Here, each R ²⁰² independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, or a heterocyclic group.

The aromatic ring represented by R ²⁰¹ is preferably phenyl or naphthyl, and particularly preferably phenyl. The aromatic ring represented by R ²⁰¹ may have at least one substituent at any substitution position. Examples of the substituent include halogen atom, hydroxyl group, cyano group, nitro group, carboxyl group, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, Alkenyloxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamide group, carbamoyl, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide Groups, alkylthio groups, alkenylthio groups, arylthio groups and acyl groups.

The heterocyclic group represented by R ²⁰¹ preferably has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, a sulfur atom or an oxygen atom, and particularly preferably a nitrogen atom. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.

When X ²⁰¹ is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms. Further, the heterocyclic group may have a hetero atom other than the nitrogen atom (for example, O, S). Examples of heterocyclic groups having free valences on nitrogen atoms are shown below. _Here, -C _{4 H} 9 (n) indicates the _n-C 4 _{H 9.}

The alkyl group represented by R ²⁰² may be a cyclic alkyl group or a chain alkyl group, but a chain alkyl group is preferable, and a linear alkyl group is more preferable than a branched chain alkyl group. preferable. The number of carbon atoms in the alkyl group is preferably 1-30, more preferably 1-20, further preferably 1-10, still more preferably 1-8, and 1-6. Most preferred. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (for example, methoxy group, ethoxy group) and an acyloxy group (for example, acryloyloxy group, methacryloyloxy group).

The alkenyl group represented by R ²⁰² may be a cyclic alkenyl group or a chain alkenyl group, but is preferably a chain alkenyl group, and is a straight chain alkenyl group rather than a branched chain alkenyl group. More preferably it represents a group. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, 6 is most preferred. The alkenyl group may have a substituent. Examples of the substituent are the same as those of the alkyl group described above.

The aromatic ring group and heterocyclic group represented by R ²⁰² are the same as the aromatic ring and heterocyclic ring represented by R ²⁰¹ , and the preferred range is also the same. The aromatic ring group and the heterocyclic group may further have a substituent, and examples of the substituent are the same as those of the aromatic ring and heterocyclic ring of ^R201 .

  Although the specific example of a compound represented by general formula (I) below is given, it is not limited to this.

  As the discotic compound, a triphenylene compound represented by the following general formula (II) can also be preferably used.

In the general formula (II), R ^{203 to} R ²⁰⁸ each independently represent a hydrogen atom or a substituent.

Examples of the substituent represented by each of R ^{203 to} R ²⁰⁸ include an alkyl group (preferably an alkyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms. Group, ethyl group, isopropyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably carbon An alkenyl group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, and examples thereof include a vinyl group, an allyl group, a 2-butenyl group, and a 3-pentenyl group. An alkynyl group (preferably an alkynyl group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 to 20 carbon atoms. For example, a propargyl group, 3-pentynyl group, etc.), an aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms). A phenyl group, a p-methylphenyl group, a naphthyl group, etc.), a substituted or unsubstituted amino group (preferably having 0 to 40 carbon atoms, more preferably 0 to 30 carbon atoms, and particularly preferably carbon number). An amino group having 0-20, for example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, an anilino group, etc., an alkoxy group (preferably having 1 to 40 carbon atoms, more preferably carbon An alkoxy group having 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as a methoxy group, an ethoxy group, and a butoxy group. An aryloxy group (preferably an aryloxy group having 6 to 40 carbon atoms, more preferably 6 to 30 carbon atoms, and particularly preferably 6 to 20 carbon atoms, such as a phenyloxy group and a 2-naphthyloxy group. Etc.), an acyl group (preferably an acyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, for example, an acetyl group, a benzoyl group, a formyl group And a pivaloyl group), an alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as a methoxycarbonyl group. , An ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably having 7 to 40 carbon atoms, more preferably Is an aryloxycarbonyl group having 7 to 30 carbon atoms, particularly preferably 7 to 20 carbon atoms, such as a phenyloxycarbonyl group, and an acyloxy group (preferably having 2 to 40 carbon atoms, more preferably carbon. An acyloxy group having 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, and examples thereof include an acetoxy group and a benzoyloxy group), an acylamino group (preferably 2 to 40 carbon atoms, more preferably 2 carbon atoms). To 30 and particularly preferably an acylamino group having 2 to 20 carbon atoms, such as an acetylamino group and a benzoylamino group, and an alkoxycarbonylamino group (preferably having 2 to 40 carbon atoms, more preferably 2 carbon atoms). To 30 and particularly preferably an alkoxycarbonylamino group having 2 to 20 carbon atoms, for example, Toxylcarbonylamino group), aryloxycarbonylamino group (preferably 7 to 40 carbon atoms, more preferably 7 to 30 carbon atoms, particularly preferably 7 to 20 carbon atoms aryloxycarbonylamino group, Examples thereof include a phenyloxycarbonylamino group), a sulfonylamino group (preferably a sulfonylamino group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms. , A methanesulfonylamino group, a benzenesulfonylamino group and the like), a sulfamoyl group (preferably a sulfamoyl group having 0 to 40 carbon atoms, more preferably 0 to 30 carbon atoms, particularly preferably 0 to 20 carbon atoms, For example, sulfamoyl group, methylsulfamoyl group, dimethyls And a carbamoyl group (preferably a carbamoyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms). An unsubstituted carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, a phenylcarbamoyl group, and the like, an alkylthio group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to carbon atoms). 20, for example, methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group, heptylthio group, octylthio group, etc.), arylthio group (preferably having 6 to 40 carbon atoms, more preferably 6 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, for example A phenylthio group), a sulfonyl group (preferably a sulfonyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as mesyl group, tosyl A sulfinyl group (preferably a sulfinyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as a methanesulfinyl group and a benzenesulfinyl group). Ureido groups (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, and examples thereof include unsubstituted ureido groups and methylureido groups. Groups, phenylureido groups, etc.), phosphoric acid amide groups (preferably having 1 to 40 carbon atoms, more preferably 1 to 1 carbon atoms). 0, particularly preferably a phosphoric acid amide group having 1 to 20 carbon atoms, such as a diethylphosphoric acid amide group and a phenylphosphoric acid amide group, a hydroxy group, a mercapto group, a halogen atom (for example, a fluorine atom, Chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 heterocyclic groups, for example, a heterocyclic group having a heteroatom such as nitrogen atom, oxygen atom, sulfur atom, etc., for example, imidazolyl group, pyridyl group, quinolyl group, furyl group, piperidyl group, morpholino Group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, 1,3,5-triazyl group, etc. A silyl group (preferably a silyl group having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, such as a trimethylsilyl group and a triphenylsilyl group). Included). These substituents may be further substituted with these substituents. Moreover, when it has two or more substituents, they may be the same or different. If possible, they may be bonded to each other to form a ring.

The substituent represented by each of R ^{203 to} R ²⁰⁸ is preferably an alkyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an alkylthio group, or a halogen atom.

  Although the specific example of a compound represented by general formula (II) below is given, it is not limited to this.

  The compound represented by the general formula (I) is, for example, a method described in JP-A No. 2003-344655, and the compound represented by the general formula (II) is, for example, a method described in JP-A-2005-134484. Can be synthesized by a known method.

  In the present invention, rod-like compounds having a linear molecular structure can be preferably used in addition to the above-mentioned discotic compounds. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation is performed using molecular orbital calculation software (for example, WinMOPAC2000, manufactured by Fujitsu Limited), and a molecular structure that minimizes the heat of formation of a compound can be obtained. The molecular structure being linear means that in the thermodynamically most stable structure obtained by calculation as described above, the angle of the main chain constituting the molecular structure is 140 degrees or more.

  As the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (III) is preferable.

Formula (III): Ar ¹ -L ¹ -Ar ²
In the general formula (III), Ar ¹ and Ar ² are each independently an aromatic group.

  In the present specification, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group.

  An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group. The heterocyclic ring of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable. As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

  Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, a cyano group, an amino group, an alkylamino group (for example, methyl Amino group, ethylamino group, butylamino group, dimethylamino group), nitro group, sulfo group, carbamoyl group, alkylcarbamoyl group (for example, N-methylcarbamoyl group, N-ethylcarbamoyl group, N, N-) Dimethylcarbamoyl group), sulfamoyl group, alkylsulfamoyl group (eg, N-methylsulfamoyl group, N-ethylsulfamoyl group, N, N-dimethylsulfamoyl group), ureido Group, alkylureido group (for example, N-methylureido group, N, N-dimethylureido group, N, N, N′-tri group) Each group of tilureido group), alkyl group (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, heptyl group, octyl group, isopropyl group, s-butyl group, tert-amyl group, cyclohexyl group, cyclopentyl) Group), alkenyl group (for example, vinyl group, allyl group, hexenyl group), alkynyl group (for example, ethynyl group, butynyl group), acyl group (for example, formyl group, acetyl group, butyryl group, Hexanoyl group, lauryl group), acyloxy group (for example, acetoxy group, butyryloxy group, hexanoyloxy group, lauryloxy group), alkoxy group (for example, methoxy group, ethoxy group, propoxy group, butoxy group) , Pentyloxy group, heptyloxy group, octyloxy group), aryl Xy group (for example, phenoxy group), alkoxycarbonyl group (for example, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, pentyloxycarbonyl group, heptyloxycarbonyl group), aryloxycarbonyl group ( For example, phenoxycarbonyl group), alkoxycarbonylamino group (for example, butoxycarbonylamino group, hexyloxycarbonylamino group), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, heptylthio group, octylthio group) Each group), arylthio group (for example, phenylthio group), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, butylsulfo group) Nyl group, pentylsulfonyl group, heptylsulfonyl group, octylsulfonyl group), amide group (for example, acetamido group, butyramide group, hexylamide group, laurylamide group) and non-aromatic heterocyclic group ( For example, a morpholyl group and a pyrazinyl group) are included.

  Among these, preferred substituents include halogen atoms, cyano groups, carboxyl groups, hydroxyl groups, amino groups, alkylamino groups, acyl groups, acyloxy groups, amide groups, alkoxycarbonyl groups, alkoxy groups, alkylthio groups, and alkyl groups. Can be mentioned.

  The alkyl part and alkyl group of the alkylamino group, alkoxycarbonyl group, alkoxy group and alkylthio group may further have a substituent. Examples of the alkyl moiety and the substituent of the alkyl group include halogen atom, hydroxyl group, carboxyl group, cyano group, amino group, alkylamino group, nitro group, sulfo group, carbamoyl group, alkylcarbamoyl group, sulfamoyl group, alkylsulfur group. Famoyl group, ureido group, alkylureido group, alkenyl group, alkynyl group, acyl group, acyloxy group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkoxycarbonylamino group, alkylthio group, arylthio group, An alkylsulfonyl group, an amide group and a non-aromatic heterocyclic group are included. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, a hydroxyl group, an amino group, an alkylamino group, an acyl group, an acyloxy group, an acylamino group, an alkoxycarbonyl group, and an alkoxy group are preferable.

In the general formula (II), L ¹ is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO—, and a combination thereof.

  The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group.

  The number of carbon atoms of the alkylene group is preferably 1-20, more preferably 1-15, still more preferably 1-10, still more preferably 1-8, and most preferably 1-6. It is.

  The alkenylene group and the alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure.

  The alkenylene group and the alkynylene group preferably have 2 to 10 carbon atoms, more preferably 2 to 8, more preferably 2 to 6, still more preferably 2 to 4, and most preferably 2. (Vinylene group or ethynylene group).

  The arylene group preferably has 6 to 20 carbon atoms, more preferably 6 to 16, and still more preferably 6 to 12.

In the molecular structure of the general formula (III), the angle formed by Ar ¹ and Ar ² across L ¹ is preferably 140 degrees or more.

  As the rod-like compound, a compound represented by the following formula (IV) is more preferable.

Formula ^{(IV): Ar 1 -L 2} -X-L 3 -Ar 2
In the general formula (IV), Ar ¹ and Ar ² are each independently an aromatic group. The definition and examples of the aromatic group are the same as those of Ar ¹ and Ar ^{2 in} the general formula (12).

In the general formula (IV), L ² and L ³ are each independently a divalent linking group selected from an alkylene group, —O—, —CO— and a group consisting of a combination thereof.

  The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure.

  The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and 1 or 2 (methylene group). Or ethylene group).

L ² and L ³ are particularly preferably —O—CO— or —CO—O—.

  In the general formula (IV), X represents a 1,4-cyclohexylene group, a vinylene group or an ethynylene group.

  Specific examples of the compound represented by the general formula (III) or (IV) include compounds described in [Chemical Formula 1] to [Chemical Formula 11] of JP-A No. 2004-109657.

  Two or more rod-shaped compounds whose maximum absorption wavelength (λmax) is longer than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination.

  The rod-like compound can be synthesized with reference to methods described in literature. As literature, Mol. Cryst. Liq. Cryst. 53, 229 pages (1979), 89, 93 pages (1982), 145, 111 pages (1987), 170 pages, 43 pages (1989), J. Am. Am. Chem. Soc. 113, p. 1349 (1991), p. 118, p. 5346 (1996), p. 92, p. 1582 (1970). Org. Chem. , 40, 420 (1975), Tetrahedron, 48, 16, 3437 (1992).

  Moreover, you may use the rod-shaped aromatic compound of pages 11-14 of Unexamined-Japanese-Patent No. 2004-50516 as said retardation expression agent.

  Further, as the retardation developer, one kind of compound can be used alone, or two or more kinds of compounds can be mixed and used. It is preferable to use two or more different compounds as the retardation enhancer because the retardation adjustment range is widened and can be easily adjusted to a desired range.

  When the cellulose acylate film is produced by a solvent cast method, the retardation developer may be added to the dope. The addition may be performed at any timing, for example, the retardation developer may be dissolved in an organic solvent such as alcohol, methylene chloride, dioxolane, and then added to the cellulose acylate solution (dope), or You may add directly in dope composition.

  In addition, specific examples of preferable compounds of rod-like compounds other than those described in the above-mentioned publications are shown below.

  The specific examples (1) to (34), (41), and (42) have two asymmetric carbon atoms at the 1-position and the 4-position of the cyclohexane ring. However, since the specific examples (1), (4) to (34), (41), and (42) have a symmetrical meso type molecular structure, there are no optical isomers (optical activity), and geometric isomers (trans Type and cis type). The trans type (1-trans) and cis type (1-cis) of specific example (1) are shown below.

  As described above, the rod-like compound preferably has a linear molecular structure. Therefore, the trans type is preferable to the cis type.

  Specific examples (2) and (3) have optical isomers (a total of four isomers) in addition to geometric isomers. As for geometric isomers, the trans type is similarly preferable to the cis type. The optical isomer is not particularly superior or inferior, and may be D, L, or a racemate.

  In specific examples (43) to (45), the central vinylene bond includes a trans type and a cis type. For the same reason as above, the trans type is preferable to the cis type.

  In the present invention, deterioration inhibitors, peeling accelerators, matting agents, lubricants, the aforementioned plasticizers, and the like can be appropriately used as necessary.

(Deterioration inhibitor)
In the present invention, a known deterioration (oxidation) inhibitor such as 2,6-di-tert-butyl-4-methylphenol, 4,4'-thiobis- (6-tert-butyl-3) is added to the cellulose acylate solution. -Methylphenol), 1,1'-bis (4-hydroxyphenyl) cyclohexane, 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, pentaerythris A phenolic or hydroquinone antioxidant such as lithyl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] can be added. Further, tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert) It is preferable to use a phosphorus-based antioxidant such as -butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite. The addition amount of the deterioration inhibitor is 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the cellulose resin.

(Peeling accelerator)
It is preferable that the λ / 4 plate according to the present invention contains a peeling accelerator from the viewpoint of improving the peelability. The peeling accelerator can be included at a ratio of 0.001 to 1% by mass, for example, and the addition of 0.5% by mass or less is preferable because separation of the release agent from the film hardly occurs. 005% by mass or more is preferable because a desired peeling reduction effect can be obtained. Therefore, it is preferably included at a rate of 0.005 to 0.5% by mass, and at a rate of 0.01 to 0.3% by mass. More preferably. As the peeling accelerator, known ones can be adopted, and organic and inorganic acidic compounds, surfactants, chelating agents and the like can be used. Among them, polyvalent carboxylic acids and esters thereof are effective, and in particular, ethyl esters of citric acid can be used effectively.

(Matting agent)
In particular, the λ / 4 plate according to the present invention is generally added with fine particles in order to prevent scratches and deterioration of transportability when handled. They are called matting agents, anti-blocking agents or anti-scratching agents and have been used conventionally. They are not particularly limited as long as they have the above-described functions, and may be an inorganic compound matting agent or an organic compound matting agent.

  Specific examples of the inorganic compound matting agent include silicon-containing inorganic compounds (for example, silicon dioxide, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, etc.), titanium oxide, and zinc oxide. , Aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin oxide / antimony, calcium carbonate, talc, clay, calcined kaolin, calcium phosphate, etc., more preferably silicon-containing inorganic compounds and oxides Although it is zirconium, since the turbidity of a cellulose acylate film can be reduced, silicon dioxide is particularly preferably used. As the silicon dioxide fine particles, for example, commercially available products having trade names such as Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. As the zirconium oxide fine particles, for example, those commercially available under trade names such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.

  Preferable specific examples of the organic compound matting agent include, for example, polymers such as silicone resin, fluorine resin and acrylic resin, and among them, silicone resin is preferably used. Among the silicone resins, those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, Tospearl 105, Tospearl 108, Tospearl 120, Tospearl 145, Tospearl 3120 and Tospearl 240 (manufactured by Toshiba Silicone Co., Ltd.) A commercial product having a trade name can be used.

  When these matting agents are added to the cellulose acylate solution, the method is not particularly limited, and there is no problem as long as a desired cellulose acylate solution can be obtained by any method. For example, an additive may be contained at the stage of mixing cellulose acylate and a solvent, or an additive may be added after preparing a mixed solution with cellulose acylate and a solvent. Further, it may be added and mixed immediately before casting the dope, which is a so-called immediately preceding addition method, and the mixing is used by installing screw-type kneading online. Specifically, a static mixer such as an in-line mixer is preferable, and the in-line mixer is, for example, a static mixer SWJ (Toray static type in-pipe mixer Hi-Mixer) (manufactured by Toray Engineering). Is preferred. As for in-line addition, in order to eliminate density unevenness, particle aggregation, etc., Japanese Patent Application Laid-Open No. 2003-053752 adds an additive solution having a different composition to the main raw material dope in a method for producing a cellulose acylate film. There is described an invention in which the distance L between the nozzle tip and the starting end portion of the in-line mixer is 5 times or less of the main raw material pipe inner diameter d, thereby eliminating concentration unevenness, matting particles and the like. As a more preferred embodiment, the distance (L) between the tip opening of the additive liquid supply nozzle having a composition different from that of the main raw material dope and the starting end of the in-line mixer is 10 times or less the inner diameter (d) of the supply nozzle tip opening. And that the in-line mixer is a static unstirred in-tube mixer or a dynamic agitated in-tube mixer. More specifically, it is disclosed that the flow rate ratio of the cellulose acylate film main raw material dope / in-line additive solution is 10/1 to 500/1, preferably 50/1 to 200/1. Furthermore, the additive is also used in Japanese Patent Application Laid-Open No. 2003-014933, which aims at a retardation film with little additive bleed-out, no delamination phenomenon between layers, and excellent slipperiness and excellent transparency. As a method of addition, it may be added in a melting pot, or a solution in which additives or additives are dissolved or dispersed between the melting pot and a co-casting die may be added to the dope being fed. However, in the latter case, it is described that it is preferable to provide a mixing means such as a static mixer in order to improve the mixing property.

  In the λ / 4 plate according to the present invention, if the matting agent is not added in a large amount, the haze of the film does not increase, and when actually used in an LCD, inconveniences such as a decrease in contrast and generation of bright spots occur. Hateful. If the amount is too small, the above-mentioned creaking and scratch resistance can be realized. From these viewpoints, it is preferably included at a ratio of 0.01 to 5.0 mass%, more preferably included at a ratio of 0.03 to 3.0 mass%, and a ratio of 0.05 to 1.0 mass% It is particularly preferable to include

<Manufacturing method of λ / 4 plate>
The λ / 4 plate according to the present invention may be produced by a solution casting method or a melt casting method as a film containing cellulose acylate, but is preferably produced by a solution casting method.

Hereinafter, the manufacturing method of the λ / 4 plate according to the present invention will be described. (Hereinafter, the λ / 4 plate according to the present invention may be referred to as a cellulose acylate film.)
The cellulose acylate film according to the present invention is prepared by dissolving cellulose acylate and the additive in a solvent to prepare a dope, casting the dope on a belt-shaped or drum-shaped metal support, It is performed by the process of drying the cast dope as a web, the process of peeling from the metal support, the process of stretching, the process of further drying, the process of further heat treating the obtained film if necessary, and the process of winding after cooling. . The cellulose acylate film used in the present invention preferably contains 60 to 95% by mass of cellulose acylate in the solid content.

(Dope preparation)
The process for preparing the dope will be described. The concentration of cellulose acylate in the dope is preferably higher because the drying load after casting on the metal support can be reduced, but if the concentration of cellulose acylate is too high, the load during filtration increases. Filtration accuracy deteriorates. As a density | concentration which makes these compatible, 10-35 mass% is preferable, More preferably, it is 15-25 mass%.

  The dope solvent used in the present invention may be used alone or in combination of two or more, but it is preferable in terms of production efficiency to use a mixture of a good solvent and a poor solvent of cellulose acylate, A larger amount of good solvent is preferred from the viewpoint of the solubility of cellulose acylate. The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent. With a good solvent and a poor solvent, what dissolve | melts the cellulose acylate to be used independently is defined as a good solvent, and a solvent that swells or does not dissolve alone is defined as a poor solvent. Therefore, depending on the degree of acetyl substitution of cellulose acylate, good solvent and poor solvent change. For example, when acetone is used as a solvent, cellulose acetate (acetyl substitution degree 2.4) becomes a good solvent, and cellulose acetate (Acetyl substitution degree 2.8) is a poor solvent.

  Although the good solvent used for this invention is not specifically limited, Organic halogen compounds, such as a methylene chloride, dioxolanes, acetone, methyl acetate, methyl acetoacetate, etc. are mentioned. Particularly preferred is methylene chloride or methyl acetate.

  Moreover, although the poor solvent used for this invention is not specifically limited, For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone, etc. are used preferably. Moreover, it is preferable that 0.01-2 mass% of water is contained in dope.

  As a method for dissolving cellulose acylate when preparing the dope described above, a general method can be used. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure. It is preferable to stir and dissolve while heating at a temperature that is equal to or higher than the boiling point of the solvent at normal pressure and that the solvent does not boil under pressure, in order to prevent the generation of massive undissolved materials called gels and mamacos. In addition, a method in which cellulose acylate is mixed with a poor solvent and wetted or swollen, and then a good solvent is added and dissolved is also preferably used.

  The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or a method of increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

  A higher heating temperature with the addition of a solvent is preferable from the viewpoint of the solubility of cellulose acylate, but if the heating temperature is too high, the required pressure increases and the productivity deteriorates. A preferable heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 ° C to 105 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature.

  Alternatively, a cooling dissolution method is also preferably used, whereby cellulose acylate can be dissolved in a solvent such as methyl acetate.

  Next, this cellulose acylate solution is filtered using a suitable filter medium such as filter paper. As the filter medium, it is preferable that the absolute filtration accuracy is small in order to remove insoluble matters and the like. However, if the absolute filtration accuracy is too small, there is a problem that the filter medium is likely to be clogged. For this reason, a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is still more preferable.

  There are no particular restrictions on the material of the filter medium, and ordinary filter media can be used. However, plastic filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel do not drop off fibers. preferable. It is preferable to remove and reduce impurities, particularly bright spot foreign matter, contained in the raw material cellulose acylate by filtration.

The bright spot foreign material is arranged in a crossed Nicols state with two polarizing plates, a cellulose acylate film is placed between them, light is applied from the side of one polarizing plate, and observation is performed from the side of the other polarizing plate. It is a point (foreign matter) where light from the opposite side sometimes leaks, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / cm ² or less. More preferably, it is 100 pieces / cm < ² > or less, More preferably, it is 50 pieces / m < ² > or less, More preferably, it is 0-10 pieces / cm < ² > or less. Further, it is preferable that the number of bright spots of 0.01 mm or less is small.

  The dope can be filtered by a normal method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration. The increase in the difference (referred to as differential pressure) is small and preferable. A preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and still more preferably 45 to 55 ° C.

  A smaller filtration pressure is preferred. The filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.

(Casting process)
The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support. 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 preferred because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate.

  The preferable support temperature is appropriately determined at 0 to 100 ° C, and more preferably 5 to 30 ° C. 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 warm 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.

  For example, when peeling from the metal support, the web is stretched in the longitudinal direction due to the peeling tension and the subsequent conveying tension. Therefore, in the present invention, when peeling the web from the casting support, the peeling and conveying tension should be as low as possible. It is preferable to carry out in a lowered state. Specifically, for example, it is effective to set it to 50 to 170 N / m or less. At that time, it is preferable to apply a cold air of 20 ° C. or less to fix the web rapidly.

  Moreover, in order for a cellulose-ester film to show favorable planarity, 10-150 mass% is preferable, and, as for the residual solvent amount at the time of peeling a web from a metal support body, More preferably, 20-40 mass% or 60-130. It is mass%, Most preferably, it is 20-30 mass% or 70-120 mass%.

  The amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Note that M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

  In the drying step of the cellulose acylate film, the web is peeled off from the metal support, and further dried, so that the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less. Particularly preferably, it is 0 to 0.01% by mass or less.

(Drying process)
In the film drying step, generally, a roll drying method (a method in which webs are alternately passed through a plurality of rolls arranged above and below) and a method in which the web is dried while being conveyed by a tenter method are employed.

  For drying the cellulose acylate film, it is preferable to further dry the film peeled off from the support to make the residual solvent amount 3% or less, more preferably 0.5% or less.

  The means for drying the film is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature is preferably increased stepwise in the range of 40 to 150 ° C, and more preferably in the range of 50 to 140 ° C in order to improve dimensional stability. In addition, it is preferable to dry for 10 to 40 minutes in the range of the softening point of the film ± 20 ° C from the viewpoint of improving the water absorption elastic modulus. The water absorption elastic modulus in the casting direction can be controlled by controlling the conveyance tension during drying of the film at the softening point ± 20 ° C. The range of preferable conveyance tension is 80 to 350 N / m, and 80 to 200 N / m is more preferable.

(Stretching process)
In the λ / 4 plate according to the present invention, the retardation Ro (590) in the in-plane direction measured at a wavelength of 590 nm is preferably in the range of 110 to 170 nm, but the retardation is preferably imparted by film stretching. .

  There is no particular limitation on the stretching method. For example, a method in which a difference in peripheral speed is applied to a plurality of rolls, and the roll peripheral speed difference is used to stretch in the longitudinal direction, the both ends of the web are fixed with clips and pins, and the interval between the clips and pins is increased in the traveling direction. And a method of stretching in the vertical direction, a method of stretching in the horizontal direction and stretching in the horizontal direction, a method of stretching in the vertical and horizontal directions and stretching in both the vertical and horizontal directions, and the like. Of course, these methods may be used in combination. That is, the film may be stretched in the transverse direction, longitudinally, or in both directions with respect to the film forming direction, and when stretched in both directions, simultaneous stretching or sequential stretching may be used. May be. In the case of the so-called tenter method, driving the clip portion by the linear drive method is preferable because smooth stretching can be performed and the risk of breakage and the like can be reduced.

  In the present invention, in particular, stretching is performed in the transport direction using the difference in peripheral speed of the film transport roll, or both ends of the web are gripped with clips or the like in the direction perpendicular to the transport direction (also referred to as the width direction or the TD direction). It is preferable to use a tenter method, and it is also preferable to use a tenter that can independently control the web gripping length (distance from the start of gripping to the end of gripping) by the left and right gripping means.

  In the present invention, either the λ / 4 plate or the polarizer according to the present invention is preferably stretched in a 45 ° direction with respect to the film transport direction in the stretching step.

  This is because a λ / 4 plate provided on the surface of a display device whose polarization axis is parallel to the long side direction or the short side direction of the polarizing plate, such as a polarizing plate used in a VA type or IPS type liquid crystal display device, When the angle between the longitudinal direction of the λ / 4 plate made of a roll-shaped polymer film and the in-plane slow axis is substantially 45 °, the longitudinal direction or the lateral direction of the long roll-shaped λ / 4 plate This is because a cut λ / 4 plate can be used, which is advantageous in production with little cut loss of the film.

  The λ / 4 plate in which the angle between the longitudinal direction and the in-plane slow axis is substantially 45 ° stretches the rolled cellulose acylate film in a direction substantially 45 ° with respect to the longitudinal direction. Can be manufactured.

  Hereinafter, a method of stretching in the 45 ° direction will be described.

  In order to obliquely stretch the cellulose acylate film in a direction substantially 45 ° with respect to the longitudinal direction, it is preferable to use a tenter shown in FIG. FIG. 4 is a schematic diagram showing oblique stretching by a tenter.

  The stretched film is produced using a tenter. This tenter is a device that widens a film fed from a film roll (feeding roll) in an oblique direction with respect to its traveling direction (moving direction of the middle point in the film width direction) in a heating environment by an oven. The tenter includes an oven, a pair of rails on the left and right on which a gripping tool for transporting the film travels, and a number of gripping tools that travel on the rails. Both ends of the film fed out from the film roll and sequentially supplied to the entrance portion of the tenter are gripped by a gripping tool, the film is guided into the oven, and the film is released from the gripping tool at the exit portion of the tenter. The film released from the gripping tool is wound around the core. Each of the pair of rails has an endless continuous track, and the gripping tool which has released the grip of the film at the exit portion of the tenter travels outside and is sequentially returned to the entrance portion.

  The rail shape of the tenter is asymmetrical on the left and right according to the orientation angle, stretch ratio, etc. given to the stretched film to be manufactured, and can be finely adjusted manually or automatically. In the present invention, a long thermoplastic resin film is stretched, and the orientation angle θ can be set to any angle within the range of 40 ° to 80 ° with respect to the winding direction after stretching. Yes. In the present invention, the gripping tool of the tenter is configured to travel at a constant speed with a certain distance from the front and rear gripping tools.

  FIG. 4 shows a rail track (rail pattern) of a tenter used for oblique stretching. The feeding direction DR1 of the cellulose acylate film is different from the winding direction (MD direction) DR2 of the stretched film, thereby obtaining a wide and uniform optical characteristic even in a stretched film having a relatively large orientation angle. It is possible. The feeding angle θi is an angle formed by the feeding direction DR1 of the film before stretching and the winding direction DR2 of the film after stretching. In the present invention, in order to produce a film having an orientation angle of 40 ° to 80 ° as described above, the feeding angle θi is set to 10 ° <θi <60 °, preferably 15 ° <θi <50 °. The By setting the feeding angle θi in the above range, the variation in the optical characteristics in the width direction of the obtained film becomes good (becomes small).

  The cellulose acylate film fed from the film roll (feeding roll) is gripped by the right and left gripping tools at the tenter inlet (position a), and then traveled as the gripping tool travels. The The left and right grips CL and CR, which are opposed to the direction of the film traveling direction (feeding direction DR1) at the tenter entrance (position a), run on a rail that is asymmetrical to the left and right, and are in a preheating zone. Through an oven having a stretching zone and a heat setting zone. Here, “substantially perpendicular” indicates that the angle formed by the straight line connecting the aforementioned gripping tools CL and CR and the film feeding direction DR1 is within 90 ± 1 °.

  The preheating zone refers to a section in which the vehicle travels while maintaining a constant interval between the gripping tools gripping both ends at the oven entrance. The stretching zone refers to an interval until the gap between the gripping tools gripping both ends starts to become constant again. In addition, the cooling zone refers to a section in which the temperature in the zone is set to be equal to or lower than the glass transition temperature Tg ° C. of the thermoplastic resin constituting the film during a period in which the interval between the gripping tools after the stretching zone becomes constant again. .

  The temperature of each zone is set to Tg + 5 to Tg + 20 ° C., the temperature of the stretching zone is set to Tg to Tg + 20 ° C., and the temperature of the cooling zone is set to Tg−30 to Tg ° C. with respect to the glass transition temperature Tg of the thermoplastic resin. It is preferable to do.

  The draw ratio R (W / Wo) in the drawing step is preferably 1.3 to 3.0 times, more preferably 1.5 to 2.8 times. When the draw ratio is within this range, thickness unevenness in the width direction is reduced, which is preferable. In the stretching zone of the tenter stretching machine, if the stretching temperature is differentiated in the width direction, the thickness unevenness in the width direction can be further improved. In addition, Wo represents the width of the film before stretching, and W represents the width of the film after stretching.

  The step of stretching in the oblique direction may be performed within the film forming step (online), or may be unwound after the film has been wound up and performed by the tenter (offline).

  The means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature in the web drying step is preferably a glass transition point of the film of −5 ° C. or less, and it is effective to perform a heat treatment at 100 ° C. or more and 10 minutes or more and 60 minutes or less. Drying is performed at a drying temperature of 100 to 200 ° C, more preferably 110 to 160 ° C.

  After the predetermined heat treatment, it is preferable to provide a slitter and cut off the end portion before winding to obtain a good winding shape. Furthermore, it is preferable to knurling both ends of the width.

  The knurling process can be formed by pressing a heated embossing roll. Fine embossing is formed on the embossing roll, and the embossing roll can be pressed to form asperity on the film and make the end bulky.

  The height of the knurling at both ends of the width of the cellulose acylate film according to the present invention is preferably 4 to 20 μm and the width is 5 to 20 mm.

  In the present invention, the knurling process is preferably provided after the drying in the film forming process and before winding.

(Haze)
In the cellulose acylate film according to the present invention, the haze is preferably less than 1%, and more preferably less than 0.5%. By setting the haze to less than 1%, there is an advantage that the transparency of the film becomes higher and it becomes easier to use as an optical film.

(Average moisture content)
In the cellulose acylate film according to the present invention, the equilibrium moisture content at 25 ° C. and a relative humidity of 60% is preferably 4% or less, and more preferably 3% or less. By setting the average moisture content to 4% or less, it is easy to cope with changes in humidity, and the optical characteristics and dimensions are more difficult to change.

(Film thickness)
The cellulose acylate film according to the present invention is preferably 30 to 100 μm. By setting the thickness to 30 μm or more, the handling property when creating a web-like film is improved, which is preferable.

(Film length, width)
The cellulose acylate film according to the present invention is preferably long, and specifically, preferably has a length of about 100 to 10,000 m, and is wound up in a roll shape. In addition, the width of the cellulose acylate film according to the present invention is preferably 1 m or more, more preferably 1.4 m or more, and particularly preferably 1.4 to 4 m.

  As described above, the λ / 4 plate according to the present invention which is a cellulose acylate film can be produced.

<Hard coat layer>
A hard coat layer is provided on the λ / 4 plate according to the present invention, and the hard coat layer is preferably either a clear hard coat layer or an antiglare hard coat layer.

  In the present invention, it is more preferable that an antireflection layer including at least a low refractive index layer is provided on the hard coat layer in order to improve visibility.

  When the hard coat layer according to the present invention is a clear hard coat layer, the clear hard coat layer has a center line average roughness (Ra) defined by JIS B 0601 of 0.001 to 0.1 μm, and Ra is 0. It is preferably 0.002 to 0.05 μm. The center line average roughness (Ra) is preferably measured by an optical interference type surface roughness measuring instrument, and can be measured, for example, using a non-contact surface fine shape measuring device WYKO NT-2000 manufactured by WYKO.

  When the hard coat layer according to the present invention is anti-glare, it has a fine uneven shape on the surface, but the fine uneven shape is formed by containing fine particles in the hard coat layer, and has the following average It can be formed by containing fine particles having a particle diameter of 0.01 μm to 4 μm in the hard coat layer. Further, as will be described later, as the surface roughness of the outermost surface of the antireflection layer provided on the antiglare hard coat layer, the center line average roughness (Ra) defined by JIS B 0601 is 0.08 μm. It is preferable to adjust to a range of ˜0.5 μm.

  As particles contained in the hard coat layer according to the present invention, for example, inorganic or organic fine particles are used.

  Examples of the inorganic fine particles include silicon oxide, titanium oxide, aluminum oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, and calcium sulfate.

  The organic fine particles include polymethyl methacrylate methyl acrylate resin fine particles, acrylic styrene resin fine particles, polymethyl methacrylate resin fine particles, silicone resin fine particles, polystyrene resin fine particles, polycarbonate resin fine particles, benzoguanamine resin fine particles, and melamine resin. Examples thereof include fine particles, polyolefin resin fine particles, polyester resin fine particles, polyamide resin fine particles, polyimide resin fine particles, and polyfluoroethylene resin fine particles.

  In the present invention, silicon oxide fine particles or polystyrene resin fine particles are particularly preferable.

  The inorganic or organic fine particles described above are preferably used in addition to a coating composition containing a resin or the like used for producing an antiglare hard coat layer.

  In order to impart antiglare properties to the hard coat layer according to the present invention, the content of inorganic or organic fine particles is 0.1 parts by mass to 100 parts by mass of the resin for preparing the antiglare hard coat layer. 30 mass parts is preferable, More preferably, it is mix | blending so that it may become 0.1-20 mass parts. In order to give a more preferable antiglare effect, it is preferable to use 1 part by mass to 15 parts by mass of fine particles having an average particle size of 0.1 μm to 1 μm with respect to 100 parts by mass of the resin for preparing the antiglare hard coat layer. . It is also preferable to use two or more kinds of fine particles having different average particle diameters.

The hard coat layer according to the present invention preferably contains an antistatic agent, and the antistatic agent comprises Sn, Ti, In, Al, Zn, Si, Mg, Ba, Mo, W, and V. A conductive material containing at least one element selected from the group as a main component and having a volume resistivity of 10 ⁷ Ω · cm or less is preferable.

  Examples of the antistatic agent include metal oxides and composite oxides having the above elements.

Examples of metal oxides are preferably ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅ , or a composite oxide thereof. In particular, ZnO, In ₂ O ₃ , TiO ₂ and SnO ₂ are preferred. Examples of containing different atoms include, for example, addition of Al, In, etc. to ZnO, addition of Nb, Ta, etc. to TiO ₂ , and addition of Sb, Nb, halogen elements, etc. to SnO ₂ . Addition is effective. The amount of these different atoms added is preferably in the range of 0.01 to 25 mol%, particularly preferably in the range of 0.1 to 15 mol%.

In addition, the volume resistivity of these metal oxide powders having conductivity is 10 ⁷ Ω · cm or less, particularly 10 ⁵ Ω · cm or less.

  From the viewpoint of imparting sufficient durability and impact resistance, the film thickness of the clear hard coat layer or the antiglare hard coat layer is preferably in the range of 0.5 μm to 15 μm, more preferably 1.0 μm to 7 μm. .

(Actinic radiation curable resin)
The hard coat layer according to the present invention preferably contains, as a binder, an actinic radiation curable resin that is cured by irradiation with actinic radiation such as ultraviolet rays.

  The actinic radiation curable resin is a resin that is cured through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin, an electron beam curable resin, and the like, but a resin that is cured by irradiation with active rays other than ultraviolet rays and electron beams may be used.

  The actinic radiation curable resin used in the present invention is preferably a hydrophilic actinic radiation curable resin from the viewpoint of preventing fine streaks and unevenness in the hot water immersion treatment or the hard coat layer coating after the steam treatment and the curing step. .

  The term “hydrophilic” as used in the present invention means that the active ray curable resin is “hydrophilic” when the surface on which the active ray curable resin is coated and cured has a surface with a water droplet contact angle of 40 ° or less. It is to be judged. The water droplet contact angle is preferably 30 ° or less, and more preferably 20 ° or less, an actinic radiation curable resin.

(Contact angle test)
Based on JIS-R3257, the contact angle is measured by dropping 3 μl of water onto the sample using a contact angle meter DM300 (Kyowa Interface Chemistry).

  Preferred hydrophilic active ray curable resins include, for example, UV curable acrylic urethane resins, UV curable polyester acrylate resins, UV curable epoxy acrylate resins, UV curable polyol acrylate resins, or UV curable epoxies. Examples thereof include resins.

  UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) in products obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer. It can be easily obtained by reacting an acrylate monomer having a hydroxyl group (hydroxyl group) such as 2-hydroxypropyl acrylate. For example, a mixture of 100 parts Unidic 17-806 (manufactured by DIC Corporation) and 1 part of Coronate L (manufactured by Nippon Polyurethane Corporation) described in JP-A-59-151110 is preferably used.

  The UV curable polyester acrylate resin can be easily obtained by reacting a monomer such as 2-hydroxyethyl acrylate, glycidyl acrylate, or acrylic acid with a hydroxyl group (hydroxyl group) or a carboxyl group at the end of the polyester. JP, 59-151112, A). For example, IRR338 (manufactured by Daicel UCB Corporation) is preferably used.

  Examples of ultraviolet curable polyol acrylate resins include ethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipenta. Examples include erythritol pentaacrylate, dipentaerythritol hexaacrylate, and alkyl-modified dipentaerythritol pentaacrylate. For example, EB11 (manufactured by Daicel UCB Co., Ltd.) is preferably used.

  The ultraviolet curable epoxy acrylate resin is obtained by reacting a terminal hydroxyl group (hydroxyl group) of an epoxy resin with a monomer such as acrylic acid, acrylic acid chloride, or glycidyl acrylate. For example, IRR337 (manufactured by Daicel UCB) is preferably used.

  As examples of the ultraviolet curable epoxy acrylate resin and the ultraviolet curable epoxy resin, useful epoxy-based active ray reactive compounds are shown.

(A) Glycidyl ether of bisphenol A (this compound is obtained as a mixture having different degrees of polymerization by reaction of epichlorohydrin and bisphenol A)
(B) a compound having a glycidyl ether group by reacting epichlorohydrin, ethylene oxide and / or propylene oxide with a compound having two phenolic OHs such as bisphenol A (c) glycidyl ether of 4,4'-methylenebisphenol (D) Epoxy compound of phenol formaldehyde resin of novolak resin or resol resin (e) Compound having alicyclic epoxide, for example, bis (3,4-epoxycyclohexylmethyl) oxalate, bis (3,4-epoxycyclohexylmethyl) ) Adipate, bis (3,4-epoxy-6-cyclohexylmethyl) adipate, bis (3,4-epoxycyclohexylmethyl pimelate), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclo Xanthcarboxylate, 3,4-epoxy-1-methylcyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, 3,4-epoxy-1-methyl-cyclohexylmethyl-3', 4'-epoxy-1 ' -Methylcyclohexanecarboxylate, 3,4-epoxy-6-methyl-cyclohexylmethyl-3 ', 4'-epoxy-6'-methyl-1'-cyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5 ', 5'-spiro-3 ", 4" -epoxy) cyclohexane-meta-dioxane (f) diglycidyl ethers of dibasic acids such as diglycidyl oxalate, diglycidyl adipate, diglycidyl tetrahydrophthalate, diglycidyl Hexahydrophthalate, diglycidylf (G) Diglycidyl ether of glycol, for example, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, copoly (ethylene glycol-propylene glycol) di Glycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether (h) Glycidyl ester of polymer acid, for example, polyglycidyl ester of polyacrylic acid, polyester diglycidyl ester (i) Polyhydric alcohol Glycidyl ethers such as glycerin triglycidyl ether, trimethylolpropane triglycidyl Ether, pentaerythritol diglycidyl ether, pentaerythritol triglycidyl ether, pentaerythritol tetraglycidyl ether, glucose triglycidyl ether (j) As the diglycidyl ether of 2-fluoroalkyl-1,2-diol, Similar to the compound examples given for the fluorine-containing epoxy compound of the fluorine-containing resin (k) As the fluorine-containing alkane-terminated diol glycidyl ether, the fluorine-containing epoxy compound of the fluorine-containing resin of the low refractive index substance can be exemplified. .

  The molecular weight of the said epoxy compound is 2000 or less as an average molecular weight, Preferably it is 1000 or less.

  When the above epoxy compound is cured by actinic radiation, it is effective to mix and use the compound having a polyfunctional epoxy group (h) or (i) in order to further increase the hardness.

  The photopolymerization initiator or photosensitizer for cationically polymerizing an epoxy actinic ray reactive compound is a compound capable of releasing a cationic polymerization initiating substance by actinic ray irradiation, and particularly preferably, cationic polymerization is initiated by irradiation. A group of double salts of onium salts that release potent Lewis acids.

  The actinic ray reactive compound epoxy resin forms a polymerized, crosslinked structure or network structure not by radical polymerization but by cationic polymerization. Unlike radical polymerization, it is a preferred active ray reactive resin because it is not affected by oxygen in the reaction system.

  The actinic ray reactive epoxy resin useful in the present invention is polymerized by a photopolymerization initiator or a photosensitizer that releases a substance that initiates cationic polymerization upon irradiation with actinic radiation. As the photopolymerization initiator, a group of double salts of onium salts that release a Lewis acid that initiates cationic polymerization by light irradiation is particularly preferable.

  A typical example is a compound represented by the following general formula (a).

General formula (a): [(R ¹ ) _a (R ² ) _b (R ³ ) _c (R ⁴ ) _d Z] ^{w +} [MeX _v ] ^w−
Wherein cation is onium, Z is S, Se, Te, P, As, Sb, Bi, O, halogen (eg, I, Br, Cl), or N = N (diazo), R ¹ , R ² , R ³ and R ⁴ are organic groups which may be the same or different. a, b, c, and d are each an integer of 0 to 3, and a + b + c + d is equal to the valence of Z. Me is a metal or metalloid which is a central atom of a halide complex, and B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, Co, etc. X is halogen, w is the net charge of the halogenated complex ion, and v is the number of halogen atoms in the halogenated complex ion.

Specific examples of the anion [MeX _v ] ^w− of the general formula (a) include tetrafluoroborate (BF ₄ ⁻ ), tetrafluorophosphate (PF ₄ ⁻ ), tetrafluoroantimonate (SbF ₄ ⁻ ), tetra Examples thereof include fluoroarsenate (AsF ₄ ⁻ ) and tetrachloroantimonate (SbCl ₄ ⁻ ).

Other anions include perchlorate ion (ClO ₄ ⁻ ), trifluoromethyl sulfite ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluenesulfonate ion, and trinitrobenzene acid anion. An ion etc. can be mentioned.

  Among these onium salts, it is particularly effective to use an aromatic onium salt as a cationic polymerization initiator. Among them, aromatic halonium salts described in JP-A Nos. 50-151996 and 50-158680 are particularly useful. VIA group aromatic onium salts described in Kaikai 50-151997, 52-30899, 59-55420, 55-125105, JP-A-56-8428, 56-149402, Preference is given to oxosulfoxonium salts described in 57-192429 and the like, aromatic diazonium salts described in JP-B-49-17040, thiopyridium salts described in US Pat. No. 4,139,655 and the like. Moreover, an aluminum complex, a photodegradable silicon compound type | system | group polymerization initiator, etc. can be mentioned. The cationic polymerization initiator can be used in combination with a photosensitizer such as benzophenone, benzoin isopropyl ether, or thioxanthone.

  In the case of an actinic ray reactive compound having an epoxy acrylate group, a photosensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine can be used. The photosensitizer and photoinitiator used for this actinic ray reactive compound are sufficient to initiate the photoreaction with 0.1 to 15 parts by mass with respect to 100 parts by mass of the ultraviolet reactive compound, Preferably they are 1 mass part-10 mass parts. The sensitizer preferably has an absorption maximum from the near ultraviolet region to the visible light region.

  In the active ray curable resin composition useful in the present invention, the polymerization initiator is generally used in an amount of 0.1 to 15 parts by mass with respect to 100 parts by mass of the active ray curable epoxy resin (prepolymer). More preferably, addition in the range of 1 to 10 parts by mass is preferable.

  An epoxy resin can also be used in combination with the urethane acrylate type resin, polyether acrylate type resin, etc. In this case, it is preferable to use an active ray radical polymerization initiator and an active ray cationic polymerization initiator in combination.

  Moreover, an oxetane compound can also be used for the hard-coat layer based on this invention. The oxetane compound used is a compound having a three-membered oxetane ring containing oxygen or sulfur. Among them, a compound having an oxetane ring containing oxygen is preferable. The oxetane ring may be substituted with a halogen atom, a haloalkyl group, an arylalkyl group, an alkoxyl group, an allyloxy group, or an acetoxy group. Specifically, 3,3-bis (chloromethyl) oxetane, 3,3-bis (iodomethyl) oxetane, 3,3-bis (methoxymethyl) oxetane, 3,3-bis (phenoxymethyl) oxetane, 3-methyl -3 chloromethyloxetane, 3,3-bis (acetoxymethyl) oxetane, 3,3-bis (fluoromethyl) oxetane, 3,3-bis (bromomethyl) oxetane, 3,3-dimethyloxetane and the like. In the present invention, any of a monomer, an oligomer and a polymer may be used.

In the hard coat layer according to the present invention, a binder such as a known thermoplastic resin, thermosetting resin, or hydrophilic resin such as gelatin can be mixed with the actinic radiation curable resin described above. These resins preferably have a polar group in the molecule. Examples of the polar _{group, -COOM, -OH, -NR 2,} -NR 3 X, -SO 3 M, -OSO 3 M, -PO 3 M 2, -OPO 3 M ( wherein, M represents a hydrogen atom, an alkali A metal or an ammonium group, X represents an acid that forms an amine salt, R represents a hydrogen atom or an alkyl group).

  When the hard coat layer according to the present invention contains an actinic radiation curable resin, the active ray irradiation method includes a hard coat layer and an antireflection layer (medium to high refractive index layer and low refractive index layer) on a support. However, it is preferable to irradiate actinic radiation when the hard coat layer is applied.

The actinic rays used in the present invention can be used without limitation as long as they are energy sources that activate the compound, such as ultraviolet rays, electron rays, and γ rays, but ultraviolet rays and electron rays are preferred, and handling is particularly simple and high energy. Ultraviolet rays are preferred because they can be easily obtained. As the ultraviolet light source for photopolymerizing the ultraviolet reactive compound, any light source that generates ultraviolet light can be used. 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. An ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like can also be used. It is preferable to use a light source having an emission spectrum in the ultraviolet region having a wavelength of 250 nm to 420 nm. Irradiation conditions vary depending on each lamp, but the irradiation light amount is preferably 20 mJ / cm ² or more, more preferably 50 mJ / cm ^{2 to} 2000 mJ / cm ² , and particularly preferably 50 mJ / cm ^{2 to} 1000 mJ / cm ^2. It is.

  The ultraviolet irradiation may be performed every time one layer is provided for each of a plurality of layers (medium refractive index layer, high refractive index layer, low refractive index layer) constituting the hard coat layer and the antireflection layer described later. The film may be irradiated after lamination. Or you may irradiate combining these. From the viewpoint of productivity, it is preferable to irradiate ultraviolet rays after laminating multiple layers.

  Moreover, an electron beam can be used similarly. As an electron beam, 50 to 1000 keV, preferably 100 to 100, emitted from various electron beam accelerators such as a cockroft Walton type, a bandegraph type, a resonance transformation type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type. An electron beam having an energy of 300 keV can be given.

  In order to initiate the photopolymerization or photocrosslinking reaction of the actinic ray reactive compound used in the present invention, the actinic ray reactive compound alone is initiated, but the induction period of polymerization is long or the initiation of polymerization is slow. For this reason, it is preferable to use a photosensitizer or a photoinitiator, whereby the polymerization can be accelerated.

  When the hard coat layer according to the present invention contains an actinic radiation curable resin, a photoreaction initiator and a photosensitizer can be used during irradiation with actinic radiation.

  Specific examples include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. Moreover, when using a photoreactant for the synthesis | combination of an epoxy acrylate-type resin, sensitizers, such as n-butylamine, a triethylamine, a tri-n-butylphosphine, can be used. The amount of the photoreaction initiator and / or photosensitizer contained in the ultraviolet curable resin composition excluding the solvent component that volatilizes after coating and drying is preferably 1% by mass to 10% by mass, particularly preferably. Is 2.5% by mass to 6% by mass.

  Moreover, when using ultraviolet curable resin as actinic radiation curable resin, you may include the ultraviolet absorber mentioned later in the ultraviolet curable resin composition to such an extent that the photocuring of the said ultraviolet curable resin is not prevented.

  In order to increase the heat resistance of the hard coat layer, an antioxidant that does not inhibit the photocuring reaction can be selected and used. Examples include hindered phenol derivatives, thiopropionic acid derivatives, phosphite derivatives, and the like. Specifically, for example, 4,4′-thiobis (6-tert-3-methylphenol), 4,4′-butylidenebis (6-tert-butyl-3-methylphenol), 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) mesitylene, di-octadecyl-4- Examples thereof include hydroxy-3,5-di-tert-butylbenzyl phosphate.

  In the present invention, other various ultraviolet curable resins can be appropriately selected and used. For example, commercially available products include Adekaoptomer KR, BY series KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (above, manufactured by ADEKA Corporation), Koeihard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS-101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (above, manufactured by Guangei Chemical Industry Co., Ltd.), Seika Beam's PHC2210 (S), PHCX-9 (K-3), PHC2213, DP-10, DP -20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (above, manufactured by Dainichi Seikagaku Corporation), K M7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (above, Daicel UC Corporation), RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120 RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by DIC Corporation), Aulex No. 340 clear (manufactured by China Paint Co., Ltd.), Sun Rad H-601 (manufactured by Sanyo Chemical Industries, Ltd.), SP-1509, SP-1507 (above, Showa Polymer Co., Ltd.), RCC-15C (Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), or other commercially available products can be used as appropriate.

  The coating composition containing the actinic radiation curable resin preferably has a solid content concentration of 10% by mass to 95% by mass, and an appropriate concentration is selected depending on the coating method.

  The hard coat layer according to the present invention also preferably contains a surfactant, and the surfactant is preferably a silicone-based or fluorine-based surfactant.

  As the silicone-based surfactant, a nonionic surfactant having a hydrophobic group composed of dimethylpolysiloxane and a hydrophilic group composed of polyoxyalkylene is preferable.

  A nonionic surfactant is a generic term for a system surfactant that does not have a group capable of dissociating into ions in an aqueous solution. In addition to a hydrophobic group, a hydroxyl group (hydroxyl group) of a polyhydric alcohol is used as a hydrophilic group. It has an oxyalkylene chain (polyoxyethylene) or the like as a hydrophilic group. The hydrophilicity increases as the number of alcoholic hydroxyl groups (hydroxyl groups) increases and as the polyoxyalkylene chain (polyoxyethylene chain) becomes longer. The nonionic surfactant according to the present invention is characterized by having dimethylpolysiloxane as a hydrophobic group.

  When a nonionic surfactant composed of a dimethylpolysiloxane having a hydrophobic group and a polyoxyalkylene having a hydrophilic group is used, unevenness of the antiglare hard coat layer and the low refractive index layer and antifouling property of the film surface are improved. It is thought that the hydrophobic group made of polymethylsiloxane is oriented on the surface and forms a film surface that is not easily soiled. This effect cannot be obtained by using other surfactants.

  Specific examples of these nonionic surfactants include, for example, Nippon Unicar Co., Ltd., silicone surfactants SILWET L-77, L-720, L-7001, L-7002, L-7604, Y-7006, FZ-2101, FZ-2104, FZ-2105, FZ-2110, FZ-2118, FZ-2120, FZ-2122, FZ-2123, FZ-2130, FZ-2154, FZ-2161, FZ-2162, FZ- 2163, FZ-2164, FZ-2166, FZ-2191 and the like.

  Moreover, SUPERSILWET SS-2801, SS-2802, SS-2803, SS-2804, SS-2805, etc. are mentioned.

  In addition, as a preferable structure of the nonionic surfactant in which the hydrophobic group is composed of dimethylpolysiloxane and the hydrophilic group is composed of polyoxyalkylene, a dimethylpolysiloxane structure portion and a polyoxyalkylene chain are alternately and repeatedly bonded. It is preferably a linear block copolymer. Since the main chain skeleton has a long chain length and a linear structure, it is excellent. This is considered to be due to the fact that one activator molecule can be adsorbed on the surface of the silica fine particle at a plurality of locations so as to cover the surface of the silica fine particle by being a block copolymer in which hydrophilic groups and hydrophobic groups are alternately repeated.

  Specific examples thereof include, for example, silicone surfactants ABN SILWET FZ-2203, FZ-2207, FZ-2208 and the like manufactured by Nippon Unicar Co., Ltd.

  As the fluorine-based surfactant, a surfactant having a hydrophobic group having a perfluorocarbon chain can be used. As types, fluoroalkylcarboxylic acid, N-perfluorooctanesulfonyl glutamate disodium, sodium 3- (fluoroalkyloxy) -1-alkylsulfonate, 3- (ω-fluoroalkanoyl-N-ethylamino) -1- Sodium propanesulfonate, N- (3-perfluorooctanesulfonamido) propyl-N, N-dimethyl-N-carboxymethyleneammonium betaine, perfluoroalkylcarboxylic acid, perfluorooctanesulfonic acid diethanolamide, perfluoroalkylsulfonic acid Salt, N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonamide, perfluoroalkylsulfonamidopropyltrimethylammonium salt, perfluoroalkyl-N-ethyl Ruhonirugurishin salts, phosphoric acid bis (N- perfluorooctylsulfonyl -N- ethylamino ethyl) and the like. In the present invention, nonionic surfactants are preferred.

  These fluorosurfactants are commercially available under the trade names such as Megafac, F-Top, Surflon, Footagen, Unidyne, Florard, Zonyl and the like.

  A preferred addition amount is 0.01 to 3.0%, more preferably 0.02 to 1.0%, based on the solid content contained in the hard coat layer coating solution.

  Other surfactants can be used in combination. For example, anionic surfactants such as sulfonates, sulfates, phosphates, etc., and ethers having polyoxyethylene chain hydrophilic groups Type, ether ester type nonionic surfactants and the like may be used in combination.

  The solvent for coating the hard coat layer in the present invention can be appropriately selected from, for example, hydrocarbons, alcohols, ketones, esters, glycol ethers, and other solvents, or can be used by mixing. . Preferably, a solvent containing 5% by mass or more, more preferably 5% by mass to 80% by mass or more of propylene glycol mono (C1-C4) alkyl ether or propylene glycol mono (C1-C4) alkyl ether ester is used.

  As a coating method of the hard coat layer composition coating solution, a known method such as a gravure coater, a spinner coater, a wire bar coater, a roll coater, a reverse coater, an extrusion coater, an air doctor coater, a spray coat, an ink jet method can be used. . The coating amount is appropriately 5 μm to 30 μm, preferably 10 μm to 20 μm in terms of wet film thickness. The coating speed is preferably 10 m / min to 200 m / min.

  The hard coat layer composition is preferably coated and dried, and then irradiated with an active ray such as an ultraviolet ray or an electron beam and cured, but the irradiation time of the active ray is preferably 0.5 seconds to 5 minutes. More preferably, it is 3 seconds to 2 minutes in view of the curing efficiency and work efficiency of the curable resin.

<Antireflection layer>
It is preferable to provide an antireflection layer on the hard coat layer of the λ / 4 plate with a hard coat layer of the present invention in order to improve visibility.

  The antireflection layer to be used may have a single layer structure consisting of only a low refractive index layer, but it is also preferable to provide a multilayer refractive index layer. A hard coat layer is provided on the λ / 4 plate, and can be laminated on the surface in consideration of the refractive index, the film thickness, the number of layers, the layer order, etc. so that the reflectance is reduced by optical interference. The antireflection layer is composed of a combination of a high refractive index layer having a higher refractive index than that of the support and a low refractive index layer having a lower refractive index than that of the support, and particularly preferably from three or more refractive index layers. An anti-reflection layer comprising three layers having different refractive indexes from the support side, a medium refractive index layer (having a higher refractive index than the support or anti-glare hard coat layer, and having a higher refractive index than the high refractive index layer). It is preferable that the layers are laminated in the order of (low layer) / high refractive index layer / 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.

  Examples of preferred layer structures of the antireflection layer according to the present invention are shown below. Here, / indicates that the layers are arranged in layers.

(Λ / 4 plate) / Clear hard coat layer / Low refractive index layer (λ / 4 plate) / Clear hard coat layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Clear hard coat layer / Medium Refractive index layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Low refractive index on the outermost surface so that dirt and fingerprints can be easily wiped off An antifouling layer can also be provided on the layer. As the antifouling layer, fluorine-containing organic compounds are preferably used.

As long as the reflectance can be reduced by optical interference, it is not limited to these layer configurations. In the above layer structure, an intermediate layer may be provided as appropriate. For example, an antistatic layer containing conductive polymer fine particles (for example, crosslinked cation fine particles) or metal oxide fine particles (for example, SnO ₂ , ITO) is preferable.

  The low refractive index layer, the middle refractive index layer, and the high refractive index layer can be formed in a known configuration, but the low refractive index layer is particularly preferably a hollow spherical silica-based fine particle, and (I) porous Composite particles composed of porous particles and a coating layer provided on the surface of the porous particles, or (II) hollow particles having a cavity inside and filled with a solvent, gas or porous substance It is done.

  The low refractive index layer, medium refractive index layer, and high refractive index layer are described in detail in JP-A-2005-266051.

  The thickness of each refractive index layer constituting the antireflection layer is preferably in the range of 1 nm to 200 nm, more preferably 5 nm to 150 nm, but each film has an appropriate thickness depending on the refractive index of each layer. It is preferable to select.

  The antireflection layer used in the present invention preferably has an average reflectance at 450 nm to 650 nm of 1% or less, particularly preferably 0.5% or less. Further, the minimum reflectance in this range is particularly preferably from 0.00 to 0.3%.

  The refractive index and film thickness of the antireflection layer can be calculated and calculated by measuring the spectral reflectance. Moreover, the reflective optical characteristic of the produced low reflection film can measure a reflectance on the conditions of a 5-degree regular reflection using a spectrophotometer.

<Polarizing plate>
The polarizing plate using the hard-coated λ / 4 plate of the present invention is such that the λ / 4 plate side of the hard-coated λ / 4 plate is bonded to the polarizer, and the absorption axis of the polarizer and the hard coat are attached. It is preferable that the slow axis of the λ / 4 plate is bonded with a substantially 45 ° inclination to form a circularly polarizing plate.

  The polarizing plate according to the present invention uses a stretched polyvinyl alcohol doped with iodine or a dichroic dye as a polarizer, and hard coat layer / (λ / 4 plate) / polarizer, or hard coat layer / (Λ / 4 plate) / Polarizer / Optical film can be bonded and manufactured.

  The optical film is not particularly limited, but is preferably a polymer film, preferably easy to manufacture, optically uniform, and optically transparent. Any of these may be used, for example, cellulose ester film, polyester film, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene terephthalate, polyethylene naphthalate. Polyester film such as polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, norbornene resin Film, polymethylpentene film, polyetherketone film, Polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, a cycloolefin polymer film, a polyvinyl acetal resin film, there may be mentioned polymethyl methacrylate film, or an acrylic film or the like, but are not limited to. As these films, films formed by a solution casting method or a melting method are preferably used. Of these, cellulose ester film, polycarbonate film, polysulfone (including polyethersulfone) and cycloolefin polymer film are preferred. In the present invention, cellulose ester film and cycloolefin polymer film are particularly advantageous in terms of production, cost and transparency. From the viewpoints of uniformity, adhesion and the like. For example, commercially available cellulose ester films include Konica Minoltack KC8UX, KC4UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC4UY, KC12UR, KC16UR, KC4UE, KC8UE, KC4UE, KC4F Etc.) are preferably used.

  The optical film is preferably an optical film that satisfies the following requirement (1) or an optical film that satisfies the following requirement (2).

  (1) The in-plane retardation value Ro (590) defined by the following formula (I) is in the range of 20 to 150 nm, and the retardation value Rt in the thickness direction defined by the following formula (II) ( 590) is in the range of 70-400 nm.

  (2) The in-plane retardation value Ro (590) defined by the following formula (I) is in the range of 0 to 5 nm, and the retardation value Rt in the thickness direction defined by the following formula (II) ( 590) is in the range of -10 to 10 nm.

Formula (I): Ro (590) = (nx−ny) × d (nm)
Formula (II): Rt (590) = {(nx + ny) / 2−nz} × d (nm)
[In the above formula, Ro (590) represents the in-plane retardation value in the film at the measurement wavelength of 590 nm, and Rt (590) represents the retardation value in the thickness direction in the film at the measurement wavelength of 590 nm. D represents the thickness (nm) of the optical film, and nx represents the maximum in-plane refractive index at the measurement wavelength of 590 nm. ny represents the refractive index in the direction perpendicular to the slow axis in the film plane at the measurement wavelength of 590 nm, and nz represents the refractive index of the film in the thickness direction at the measurement wavelength of 590 nm. ]
The above Ro and Rt can be measured using an automatic birefringence meter. Using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments), Ro and Rt are calculated by birefringence measurement under an environment of 23 ° C. and 55% RH.

  When the optical film satisfies the requirement (1), it can be suitably used for a VA liquid crystal display device described later.

  When the optical film satisfies the requirement (2), it can be suitably used for an IPS liquid crystal display device described later.

  Examples of the polarizer preferably used in the polarizing plate according to the present invention include a polyvinyl alcohol polarizing film, which includes a polyvinyl alcohol film dyed with iodine and a dichroic dye dyed. As the polyvinyl alcohol film, a modified polyvinyl alcohol film modified with ethylene is preferably used. For the polarizer, a polyvinyl alcohol aqueous solution is formed into a film and dyed by uniaxial stretching or dyed or uniaxially stretched and then preferably subjected to a durability treatment with a boron compound. Stretching is preferably performed uniaxially in the film forming direction, or stretched in an oblique 45 ° direction using the above-described oblique stretching apparatus with respect to the film forming direction.

  The film thickness of the polarizer is 5 to 40 μm, preferably 5 to 30 μm, and particularly preferably 5 to 20 μm.

  The polarizing plate can be produced by a general method. The λ / 4 plate with hard coat of the present invention that has been subjected to alkali saponification treatment is bonded to at least one surface of a polarizer produced by immersing and stretching a polyvinyl alcohol film in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. It is preferable to match. It is preferable to saponify and bond the optical film to the other surface in the same manner.

  In the production of a λ / 4 plate with a hard coat of the present invention, in the case of a λ / 4 film with a hard coat produced by stretching in a direction of 45 ° from the longitudinal direction, the absorption axis of the polarizing film is positioned in the longitudinal direction. The polarizer and the longitudinal direction of the polarizer and the slow axis of the λ / 4 plate are 10 ° or more and less than 90 °, more preferably 20 ° or more and less than 70 °, still more preferably 40 ° or more and less than 50 °, particularly It can be continuously bonded by roll-to-roll so that it is preferably 44 ° or more and less than 46 °.

  Further, in the production of a λ / 4 plate with a hard coat of the present invention, a λ / 4 plate with a hard coat produced by stretching in the longitudinal direction and a polarizer having an absorption axis in the longitudinal direction are bonded. Before bonding, the λ / 4 plate with a hard coat of the present invention and the polarizer are each punched, and the absorption axis of the polarizing film and the slow axis of the λ / 4 plate are 10 ° or more and less than 90 °, more preferably 20 It can be bonded together in a single sheet so that it is not less than 70 ° and more preferably not less than 40 ° and less than 50 °, particularly preferably not less than 44 ° and less than 46 °.

  The polarizing plate can be constructed by further bonding a protective film on one surface of the polarizing plate and a separate film on the opposite surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection.

<Liquid crystal display device>
In the liquid crystal display device according to the present invention, it is preferable that the polarizing plate is disposed on the viewing side with respect to the liquid crystal cell, and the liquid crystal cell, the polarizer, the λ / 4 plate, and the hard coat layer are provided in this order. Alternatively, the liquid crystal cell, the optical film, the polarizer, the λ / 4 plate, and the hard coat layer are preferably provided in this order.

  By using the polarizing plate according to the present invention as a liquid crystal display device bonded to the surface on the viewing side of the liquid crystal cell, the display image is difficult to see depending on the direction of the polarization axis even when observed through an optical member having a polarizing action such as polarized sunglasses. Therefore, the liquid crystal display device according to the present invention having higher durability against the use environment can be manufactured. The polarizing plate according to the present invention is a reflective type, transmissive type, transflective type LCD or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type, etc. Preferably used.

(Stereoscopic image display device)
The λ / 4 plate with hard coat of the present invention can be used in various modes in a stereoscopic image display device. For example, a stereoscopic image display device including a liquid crystal display device and liquid crystal shutter glasses, the liquid crystal shutter glasses being provided with (1) a λ / 4 plate with a hard coat, a liquid crystal cell, and a polarizer in this order. Or (2) a liquid crystal shutter glasses in which a λ / 4 plate with a hard coat, a polarizer, a liquid crystal cell, and a polarizer are provided in this order, and can be used in a stereoscopic image display device according to an aspect .

  FIG. 5 shows a schematic diagram of the stereoscopic image display apparatus according to the above-described aspect (1) (system in which the polarizing plate of the glasses is a single sheet). Moreover, the schematic diagram of the aspect of said (2) (The polarizing plate of glasses is a system with two sheets) is shown in FIG.

  In any case, the front polarizing plate of the liquid crystal display device has a configuration in which a λ / 4 plate, a polarizer, an optical film cell, and a polarizer are provided in this order.

  In the present invention, with the above-described aspect and configuration, crosstalk or luminance reduction and color change when tilting the head when viewing a stereoscopic (3D) image can be reduced, and excellent visibility with respect to the use environment can be maintained. Therefore, a stereoscopic image display device with higher durability against the use environment can be obtained.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
<Production of λ / 4 plate 101 with hard coat>
<Production of λ / 4 plate>
<Fine particle dispersion 1>
Fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.) 11 parts by weight Ethanol 89 parts by weight The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.

<Fine particle addition liquid 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.

Methylene chloride 99 parts by mass Fine particle dispersion 1 5 parts by mass A main dope solution having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose acetate was added to a pressurized dissolution tank containing a solvent while stirring. This is completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No. The main dope solution was prepared by filtration using 244.

<Composition of main dope solution>
Methylene chloride 340 parts by mass Ethanol 64 parts by mass Diacetyl cellulose having an acetyl group substitution degree of 2.45 100 parts by mass Triphenyl phosphate (TPP) 10 parts by mass Biphenyl diphenyl phosphate (BDP) 5 parts by mass Retardation agent (discotic compound I -(2)) 2.5 parts by mass UV absorber (Tinubin 928 (BASF Japan Ltd.)) 2 parts by mass Particulate additive solution 1 1 part by mass A liquid was prepared. Next, an endless belt casting apparatus was used to uniformly cast the dope solution on a stainless steel belt support at a temperature of 33 ° C. and a width of 2000 mm. The temperature of the stainless steel belt was controlled at 30 ° C.

  On the stainless steel belt support, the solvent was evaporated until the residual solvent amount in the cast (cast) film was 75%, and then peeled off from the stainless steel belt support with a peeling tension of 130 N / m.

  After peeling off the peeled cellulose acetate film, using the apparatus described in Example 1 of JP 2009-214441 (stretching machine A: FIG. 11), the temperature is 170 ° C., the magnification is 1.5 times, and the slow axis is Stretching was performed in an oblique direction so as to form 45 ° with the film width direction.

  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.

  As described above, a λ / 4 plate having a dry film thickness of 50 μm and a length of 3000 m was obtained.

<Application of hard coat layer>
Next, the above-mentioned λ / 4 plate is die-coated with the following hard coat layer coating solution, dried at 80 ° C., and then irradiated with 120 mJ / cm ² of ultraviolet light with a high-pressure mercury lamp so that the film thickness after curing becomes 6 μm. A λ / 4 plate 101 with a hard coat was prepared by providing a clear hard coat layer.

(Coating solution for hard coat layer)
Acetone 45 parts by mass Ethyl acetate 45 parts by mass Propylene glycol monomethyl ether 10 parts by mass Urethane acrylate (DIC Unidic RS27-921)
100 parts by mass 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by BASF Japan) 5 parts by mass 2-methyl-1- [4- (methylthio) phenyl] -2-monoforino-1-one (Irgacure 907, 3 parts by mass BYK-331 (silicone surfactant, manufactured by Big Chemie Japan Co., Ltd.)
0.5 parts by mass In addition, the water droplet contact angle of the surface coated and cured with urethane acrylate (DIC Unidic RS27-921) was 40 ° or less, and it was confirmed that the resin was a hydrophilic actinic radiation curable resin.

(Contact angle test)
Based on JIS-R3257, the contact angle is measured by dropping 3 μl of water onto the sample using a contact angle meter DM300 (Kyowa Interface Chemistry).

<Preparation of λ / 4 plate 102 with hard coat>
In the production of the hard-coated λ / 4 plate 101, the λ / 4 plate was introduced into the water vapor treatment chamber shown in FIG. 3, and 70 ° C. water vapor was jetted onto the surface for 3 minutes, and 30 seconds passed from the water vapor treatment chamber. The hard coat layer was applied to produce a λ / 4 plate 102 with a hard coat.

<Production of λ / 4 plate 103 with hard coat>
In producing the λ / 4 plate 102 with hard coat, the λ / 4 plate 103 with hard coat was produced in the same manner except that the λ / 4 plate was changed to the following main dope solution and subjected to water vapor treatment.

<Composition of main dope solution>
Methylene chloride 340 parts by mass Ethanol 64 parts by mass Diacetyl cellulose having an acetyl group substitution degree of 2.45 100 parts by mass Compound (FA-6) represented by the general formula (FA) 10 parts by mass UV absorber (TINUVIN 928 (BASF Japan (Made by Co., Ltd.)) 2 parts by mass Particulate additive solution 1 1 part by mass <Preparation of λ / 4 plate 104 with hard coat>
In producing the λ / 4 plate 103 with hard coat, the λ / 4 plate 104 with hard coat was produced in the same manner except that the λ / 4 plate was changed to the following main dope solution and subjected to water vapor treatment.

<Composition of main dope solution>
Methylene chloride 340 parts by mass Ethanol 64 parts by mass Diacetyl cellulose having an acetyl group substitution degree of 2.45 100 parts by mass Compound (FA-6) represented by formula (FA) 10 parts by mass Retardation agent (discotic compound I -(2)) 2.5 parts by mass UV absorber (Tinubin 928 (manufactured by BASF Japan Ltd.)) 2 parts by mass Particulate additive solution 1 1 part by mass <Production of λ / 4 plates 105 to 123 with hard coat>
In the production of the hard coat λ / 4 plate 104, the degree of acetyl group substitution of diacetyl cellulose, the type of compound represented by the general formula (FA), the type of plasticizer, the type of retardation developing agent, the film thickness, the stretching direction In the same manner as described in Table 2, except that the conditions for immersion treatment with water vapor or warm water, the time from application of water vapor or warm water immersion treatment to the application of the hard coat layer were changed as shown in Table 2, λ / 4 Plates 105-123 were produced.

  The MD in the stretching direction represents a direction parallel to the conveyance direction of the web, and “warm water immersion” represents that the immersion treatment with warm water was performed using the treatment tank of FIG.

  The λ / 4 plates 121 to 123 with hard coat were subjected to steam treatment before stretching at the time of preparing the λ / 4 plate, wound into a roll shape after stretching and drying, and fed out from the roll the next day to apply a hard coat layer.

  Moreover, the polyester a and the polyester b represent the following compounds, and the addition amount was 10 mass parts for both.

(Synthesis of polyester (a))
In a nitrogen atmosphere, 19.2 g of dimethyl 2,6-naphthalenedicarboxylate, 14.9 g of 1,2-propylene glycol and 20 mg of tetraisopropyl titanate were mixed, and the mixture was stirred at 165 ° C. for 1 hour while distilling off the produced methanol. It was. The mixture was further stirred at 185 ° C. for 1 hour, then heated to 195 ° C. and stirred for 18 hours. Next, the temperature was lowered to 170 ° C., and unreacted 1,2-propylene glycol was distilled off under reduced pressure to obtain a polyester polyol (a).

Acid value: 0.2
Number average molecular weight: 1020
Dispersity: 1.6
Component content of molecular weight 300-1800: 48%
Hydroxyl (hydroxyl) value: 110
Hydroxyl content: 100%
It was confirmed by ¹ H-NMR that there was no methyl ester residue at the end.

<Synthesis of polyester (b)>
In a nitrogen atmosphere, 4.85 g of dimethyl terephthalate, 4.4 g of 1,2-propylene glycol, 6.8 g of p-toluic acid, and 10 mg of tetraisopropyl titanate were mixed and stirred at 140 ° C. for 2 hours. Stirring was carried out at ° C for 16 hours. Next, the temperature was lowered to 170 ° C., and unreacted 1,2-propylene glycol was distilled off under reduced pressure to obtain polyester (b).

Acid value: 0.1
Number average molecular weight: 490
Dispersity: 1.4
Component content of molecular weight 300-1800: 90%
Hydroxyl (hydroxyl) value: 0.1
Hydroxyl content: 0.04%
Polyester b has a toluic acid ester at the end because monocarboxylic acid is used in an amount twice as much as that of dicarboxylic acid.

[Evaluation]
<Measurement of retardation Ro and Rt>
A 35 mm × 35 mm sample was cut out from the obtained film, conditioned for 2 hours in an environment of 23 ° C. and 55% RH, and the following formula from the value measured at 590 nm with an automatic birefringence meter (KOBRA21DH, Oji Scientific Co., Ltd.). Then, Ro (590) and Rt (590) were obtained.

Formula (I): Ro (590) = (nx−ny) × d (nm)
Formula (II): Rt (590) = {(nx + ny) / 2−nz} × d (nm)
[In the above formula, Ro (590) represents the in-plane retardation value in the film at the measurement wavelength of 590 nm, and Rt (590) represents the retardation value in the thickness direction in the film at the measurement wavelength of 590 nm. D represents the thickness (nm) of the optical film, and nx represents the maximum in-plane refractive index at the measurement wavelength of 590 nm. ny represents the refractive index in the direction perpendicular to the slow axis in the film plane at the measurement wavelength of 590 nm, and nz represents the refractive index of the film in the thickness direction at the measurement wavelength of 590 nm. ]
<Evaluation of minute streaks and unevenness>
The produced hard-coated λ / 4 plate was visually evaluated for fine streaks and unevenness according to the following criteria.

(Small streaks, unevenness)
○: No slight streaks or unevenness (can be used)
Δ: Weak minute streaks and unevenness (Possible to use weak ones)
×: Strong streaks and unevenness (not practical)
Table 2 shows the configuration of the λ / 4 plate with hard coat and the evaluation results.

  From Table 2, the λ / 4 plates 103 to 116 with hard coat according to the present invention have an appropriate retardation as a λ / 4 plate with respect to the comparative example, and the steam treatment or hot water according to the present invention is used. It is clear that the immersion treatment used is excellent in fine streaks and unevenness after the hard coat layer is applied.

Example 2
In the production of the hard coat λ / 4 plate 104 of Example 1, the steam treatment temperature was changed to 80 ° C., the treatment time was changed to 50 seconds, and the time to apply the hard coat layer was changed to 40 seconds, and the activity used for the hard coat layer was further changed. Λ / 4 plates 124 to 132 with hard coat were produced in the same manner except that the compounds shown in Table 3 were used as the types of the linear curable resins.

  As for the hydrophilicity of the used actinic radiation curable resin, the water droplet contact angle was measured in the same manner as in Example 1. As a result, a compound having a hydrophilicity of 40 ° or less and having a hydrophilic property was marked with ◯, and a non-hydrophilic compound was marked with ×.

  Further, slight unevenness of the produced λ / 4 plates 124 to 132 with hard coat was evaluated in the same manner as in Example 1 and shown in Table 3.

  From Table 3, it can be seen that the use of the hydrophilic actinic radiation curable resin for the hard coat layer effectively improves the generation of fine streaks and unevenness due to the steam treatment according to the present invention.

Example 3
The following antireflection layer was further provided on the hard coat layer of the produced λ / 4 plate with hard coat to prepare λ / 4 plates 101ar to 132ar with antireflection layer.

<Application of antireflection layer>
(Application of medium refractive index layer)
The following medium refractive index layer coating solution is die-coated on the surface of the hard coat layer, dried at 80 ° C., and then irradiated with 120 mJ / cm ² of ultraviolet light with a high-pressure mercury lamp so that the cured film thickness becomes 110 nm. A medium refractive index layer was provided. The refractive index was 1.60.

<Medium refractive index layer coating solution>
<Preparation of particle dispersion A>
Methanol-dispersed antimony double oxide colloid (solid content 60%, zinc antimonate sol manufactured by Nissan Chemical Industries, Ltd., trade name: Celnax CX-Z610M-F2) 6.0 kg of isopropyl alcohol was gradually stirred with stirring. To prepare a particle dispersion A.

PGME (propylene glycol monomethyl ether) 40 parts by mass Isopropyl alcohol 25 parts by mass Methyl ethyl ketone 25 parts by mass Pentaerythritol triacrylate 0.9 parts by mass Pentaerythritol tetraacrylate 1.0 part by mass Urethane acrylate (trade name: U-4HA Shin-Nakamura Chemical 0.6 parts by mass Particle dispersion A 20 parts by mass 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by BASF Japan Ltd.) 0.4 parts by mass 2-methyl-1- [4- (methylthio) Phenyl] -2-monoforinopropan-1-one (Irgacure 907, manufactured by BASF Japan) 0.2 parts by mass 10% FZ-2207, propylene glycol monomethyl ether solution (manufactured by Nippon Unicar) 0.4 parts by mass Coating of the low refractive index layer)
On the medium refractive index layer, the following low refractive index layer coating solution is die-coated, dried at 80 ° C., and then irradiated with 120 mJ / cm ² of ultraviolet light with a high pressure mercury lamp so that the film thickness becomes 92 nm. A rate layer was provided to prepare an antireflection layer. The refractive index was 1.38.

(Low refractive index layer coating solution)
<Preparation of tetraethoxysilane hydrolyzate A>
After mixing 230 g of tetraethoxysilane (trade name: KBE04, manufactured by Shin-Etsu Chemical Co., Ltd.) and 440 g of ethanol and adding 120 g of a 2% aqueous acetic acid solution thereto, the mixture is stirred for 26 hours at room temperature (25 ° C.). Silane hydrolyzate A was prepared.

Propylene glycol monomethyl ether 430 parts by mass Isopropyl alcohol 430 parts by mass Tetraethoxysilane hydrolyzate A 120 parts by mass γ-methacryloxypropyltrimethoxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.) 3.0 parts by mass Isopropyl alcohol dispersion Hollow silica sol (solid content 20%,
Silica sol manufactured by Catalyst Kasei Kogyo Co., Ltd., trade name: ELCOM V-8209) 40 parts by mass Aluminum ethyl acetoacetate diisopropylate (manufactured by Kawaken Fine Chemical Co., Ltd.) 3.0 parts by mass 10% FZ-2207, propylene glycol monomethyl ether solution ( Manufactured by Nippon Unicar Co., Ltd.) 3.0 parts by mass <Preparation of optical film for protecting polarizer>
(Preparation of optical film 150)
<Fine particle dispersion 1>
Fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.) 11 parts by weight Ethanol 89 parts by weight The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.

<Fine particle addition liquid 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.

Methylene chloride 99 parts by mass Fine particle dispersion 1 5 parts by mass A main dope solution having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose acetate was added to a pressurized dissolution tank containing a solvent while stirring. This is completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No. The main dope solution was prepared by filtration using 244.

<Composition of main dope solution>
Methylene chloride 340 parts by mass Ethanol 64 parts by mass Cellulose ester (cellulose acetate propionate acyl group total substitution degree 2.75, acetyl group substitution degree 0.19, propionyl group substitution degree 2.56, Mw = 200000)
100 parts by mass Compound (FA-2) represented by formula (FA) 10 parts by mass Polyester (b) 2.5 parts by mass UV absorber (Tinubin 928 (manufactured by BASF Japan Ltd.)) 2.3 parts by mass Particulate additive solution 1 1 part by mass The above composition was put into a closed container and dissolved while stirring to prepare a dope solution. Next, an endless belt casting apparatus was used to uniformly cast the dope solution on a stainless steel belt support at a temperature of 33 ° C. and a width of 2000 mm. The temperature of the stainless steel belt was controlled at 30 ° C.

  On the stainless steel belt support, the solvent was evaporated until the residual solvent amount in the cast (cast) film was 75%, and then peeled off from the stainless steel belt support with a peeling tension of 130 N / m.

  Thereafter, the film is stretched 1.4 times in the width direction by a tenter set at 170 ° C., then dried by being transported for 30 minutes in a drying zone set at 130 ° C., and has a width of 2 m and a width of 1 cm at the end. An optical film 150 having a film thickness of 40 μm having a knurling height of 8 μm was prepared and wound up at 3000 m.

  The retardation values Ro (590) and Rt (590) of the optical film 150 were 50 nm and 130 nm, respectively.

(Preparation of optical film 151)
<Composition of main dope solution>
Acrylic resin (A): BR100 (acrylic resin, manufactured by Mitsubishi Rayon Co., Ltd.)
70 parts by mass Cellulose ester resin (B): cellulose ester (cellulose acetate propionate acyl group total substitution degree 2.75, acetyl group substitution degree 0.19, propionyl group substitution degree 2.56, Mw = 200000) 30 parts by mass Methylene chloride 264 parts by mass Ethanol 36 parts by mass The above-prepared dope solution was uniformly cast on a stainless steel band support at a temperature of 22 ° C. and a width of 2 m using a belt casting apparatus. With the stainless steel band support, the solvent was evaporated until the residual solvent concentration (residual solvent amount) reached 100%, and the film was peeled off from the stainless steel band support with a peeling tension of 162 N / m. At this time, the time required from casting to peeling was 100 seconds. The peeled acrylic resin web was evaporated at 35 ° C., slit to 1.6 m width, and then dried at a drying temperature of 135 ° C. while being stretched 1.1 times in the width direction by a tenter. At this time, the residual solvent concentration when starting stretching with a tenter was 10% by mass. After stretching with a tenter and relaxing at 130 ° C for 5 minutes, drying was completed while transporting the drying zone at 120 ° C and 130 ° C with a number of rolls, slitting to a width of 1.5 m, and 10 mm wide at both ends of the film. A knurling process of 5 μm was performed and wound around a 6-inch inner diameter core with an initial tension of 220 N / m and a final tension of 110 N / m to obtain an acrylic resin-containing optical film 151 with a film thickness of 40 μm and a winding number of 3000 m. The draw ratio in the MD direction calculated from the rotational speed of the stainless steel band support and the operating speed of the tenter was 1.1 times.

  The retardation values Ro (590) and Rt (590) of the optical film 151 were 3 nm and 5 nm, respectively.

<Preparation of polarizing plates 201-240>
A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times).

  This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a long polarizer.

  Next, the polarizer and the antireflection layer-attached λ / 4 plates 101ar to 132ar and the optical film 150 or the optical film 151 are bonded to each other by roll-to-roll according to the following steps 1 to 5, and the absorption axis of the polarizer. And long polarizing plates 201 to 240 in which the slow axis of the λ / 4 plate is inclined 45 °.

  Step 1: Soaked in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, then washed with water and dried to obtain λ / 4 plates 101ar to 132ar saponified on the side to be bonded to the polarizer.

  Process 2: The said polarizer was immersed in the polyvinyl alcohol adhesive tank of 2 mass% of solid content for 1-2 seconds.

  Step 3: Excess adhesive adhered to the polarizer in Step 2 was gently wiped off and placed on the λ / 4 plates 101ar to 132ar treated in Step 1.

Step 4: The λ / 4 plates 101ar to 132ar laminated in Step 3 and the polarizer and the optical film 150 or the optical film 151 were bonded at a pressure of 20 to 30 N / cm ² and a conveyance speed of about 2 m / min.

  Step 5: Samples obtained by bonding the polarizer prepared in Step 4 with the λ / 4 plates 101ar to 132ar and the optical film 150 or the optical film 151 in a dryer at 80 ° C. are dried for 2 minutes. Polarizing plates 201 to 240 corresponding to the four plates 101ar to 132ar were prepared.

  The λ / 4 plate 116ar with an antireflection layer was cut in an oblique 45 ° direction because the slow axis was parallel to the longitudinal direction by MD stretching.

<Production of liquid crystal display device>
A liquid crystal panel for viewing angle measurement was produced as follows, and the characteristics as a liquid crystal display device were evaluated.

  Remove the pre-bonded front plate of Sony 60-type display BRAVIA LX900, remove the filler between the front plate and the polarizing plate on the front of the panel, and peel off the pre-bonded front polarizing plate of the panel And the produced said polarizing plates 201-240 were each bonded on the front surface of the glass surface of a liquid crystal cell.

  At that time, the polarizing plate is bonded so that the surface of the λ / 4 plate is on the viewing side and the absorption axis is directed in the same direction as the previously bonded polarizing plate. Liquid crystal display devices 301 to 340 corresponding to the polarizing plates 201 to 240, respectively, were produced.

(3D glasses)
The λ / 4 plate 104 with hard coat produced in Example 1 was bonded to the panel side of the 3D glasses TDG-BR100 made by SONY.

  The produced liquid crystal display device was evaluated for crosstalk when the head was tilted during 3D video viewing.

<< Evaluation of crosstalk when tilting the head when viewing 3D images >>
Watch the 3D image with 23D and 55% RH in the 3D glasses immediately after turning on the backlight of each liquid crystal display device and tilting the neck so that the glasses are tilted 25 ° The crosstalk was evaluated according to the following criteria.

A: There is no crosstalk. O: Very weak crosstalk is visible but there is no problem in practical use. Δ: Weak crosstalk is visible. X: Crosstalk is clearly visible.

《Contrast unevenness》
The measurement was performed after the backlight of each liquid crystal display device was lit continuously for 1 hour in an environment of 23 ° C. and 55% RH. For measurement, EZ-Contrast 160D manufactured by ELDIM was used to measure the luminance from the normal direction of the display screen of white display and black display with a liquid crystal display device, and the ratio was defined as the front contrast.

Front contrast = (brightness of white display measured from the normal direction of the display device)
/ (Luminance of black display measured from normal direction of display device)
The front contrast at any 10 points of the liquid crystal display device was measured and evaluated according to the following criteria.

  Contrast unevenness is caused by wrinkles and distortions generated in the hard coat film.

A: There is no variation in front contrast and there is no unevenness. ○: The variation in front contrast is less than 1 to 5% and the variation is small. Δ: The front contrast is less than 5 to 10% and the variation is slightly Yes: The front contrast is a variation of 10% or more, and the unevenness is large.

  From the results shown in Table 4, the fine streaks and unevenness generated in the λ / 4 plate produced by oblique stretching can be eliminated, and the variation in crosstalk or front contrast when tilting the neck can be reduced. It is clear that an excellent stereoscopic image display device can be obtained.

DESCRIPTION OF SYMBOLS 1 Steam processing chamber 2, 2 'Nip roll 3 Steam nozzle 4 Air knife 5 λ / 4 board DR1 Feeding direction DR2 Winding direction θi Feeding angle (An angle formed between the feeding direction and the winding direction)
CR, CL Gripping device Wo Width of film before stretching W Width of film after stretching A Liquid crystal shutter glasses A1, A4 Polarizer A2 Liquid crystal cell A3 λ / 4 plate B Liquid crystal display device (for example, television (TV))
C Polarizing plate C1 λ / 4 plate C2 Polarizer C3 Optical film C4 Polarizer protective film D Liquid crystal cell E Polarizing plate F Backlight a Absorption axis b Slow axis

Claims (6)

Λ containing a cellulose acylate having a total acyl substitution degree of 2.0 to 2.5 and a compound having a total average substitution degree represented by the following general formula (FA) in the range of 3.0 to 6.5 A method for producing a λ / 4 plate with a hard coat in which a hard coat layer is provided on the / 4 plate, wherein the λ / 4 plate is subjected to hot water immersion treatment or steam treatment , and continuously within 1 second to 5 minutes. A method for producing a λ / 4 plate with a hard coat, comprising applying a hard coat layer.

(Wherein R _{1 to} R ₈ each independently represents a substituted or unsubstituted alkylcarbonyl group or a substituted or unsubstituted arylcarbonyl group, and R _{1 to} R ₈ may be the same as each other) , May be different.)   The method for producing a λ / 4 plate with a hard coat according to claim 1, wherein the hard coat layer contains a hydrophilic actinic radiation curable resin.   A long λ / 4 plate that is obliquely stretched so that the angle between the width direction and the slow axis in the plane of the λ / 4 plate is in the range of 40 to 50 °. The method for producing a λ / 4 plate with a hard coat according to claim 1 or 2, wherein:   The method for producing a λ / 4 plate with a hard coat according to any one of claims 1 to 3, wherein an antireflection layer having at least a low refractive index layer is provided on a surface of the hard coat layer. . A λ / 4 plate with a hard coat manufactured by the method for manufacturing a λ / 4 plate with a hard coat according to any one of claims 1 to 4, is bonded to at least one surface of a polarizer. The manufacturing method of the polarizing plate to do . A method for producing a liquid crystal display device , comprising: a polarizing plate produced by the method for producing a polarizing plate according to claim 5 bonded to a viewing side of a liquid crystal cell.

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