KR20170009629A - Liquid crystal coating retardation polarized plate film for OLED - Google Patents

Abstract

The present invention relates to a liquid crystal coating retardation polarized film for OLED, and more particularly, to a liquid crystal coating retardation polarized film for OLE which has improved reliability and optical reliability and excellent optical reliability, by including additives and a resin capable of improving high temperature and high humidity reliability. The liquid crystal coating retardation polarized film includes a liquid crystal coating layer; a liquid crystal coating base film; a PVA film; and a PVA protection film.

Description

[0001] The present invention relates to a liquid crystal coated retardation film for OLED,

The present invention relates to a liquid crystal coated phase difference polarizer film for OLED, and more particularly, to a liquid crystal coated phase difference polarizer film for OLED, which has improved reliability and optical reliability by including a resin and additives capable of improving high temperature and high humidity reliability .

In recent years, the development of thin and lightweight notebook computers is under way. Accordingly, a protective film of a polarizing plate used in a display device such as a liquid crystal display device has been increasingly demanded for further thinning and higher performance. Since a liquid crystal display device displays a display by polarization control by a liquid crystal, a polarizing plate is required, and a polarizing plate in which a PVA film containing iodine is stretched is usually used. Since the polarizing plate is fragile, a polarizing plate protective film is used to protect the polarizing plate. In general, triacetylcellulose film is widely used for a polarizing plate protective film. In addition to these polarizing plate protective films, a retardation film is also used to control the retardation of the polarized light. The retardation film used liquid crystal display device or the like may be used in order to solve the problems such as color compensation and wide viewing angle by using a retardation (R _th) in the thickness direction by the use in combination with a polarizing plate, and the phase difference in-plane direction (R _o) May have a function of converting linearly polarized light into circularly polarized light with respect to the wavelength of the visible light region or conversely converting circularly polarized light into linearly polarized light.

The polarizing plate protective film is intended to protect the polarizing plate and it is most preferable to use a film made of cellulose acetate in order to protect the polarizing plate made of PVA containing moisture, considering the production process of the polarizing plate. On the other hand, as a retardation film, materials other than cellulose acetate have been used to exhibit optical performance. That is, conventionally, as a material of the retardation film, for example, there are polycarbonate, polysulfone, polyethersulfone, amorphous polyolefin and the like. These polymer films have such characteristics that the longer the wavelength is, the smaller the retardation, and it is difficult to impart an ideal retardation property to the entire wavelength of the visible light region.

In the case where linearly polarized light is converted into circularly polarized light with respect to the wavelength of the visible light region or conversely circularly polarized light is converted into linearly polarized light, in order to obtain the above effect with one piece of retardation film, the retardation in the wavelength? 4 < / RTI > Such a retardation film can be obtained by using, for example, a retardation film having a phase difference of? / 4 and only one polarizing plate for a reflective liquid crystal display device having a back electrode as a reflective electrode, thereby obtaining a reflective display device having excellent image quality . Further, with respect to the observer of the guest-host type liquid crystal layer, the retardation film is used on the back side, or the circularly polarized light of the reflection type polarizing plate composed of cholesteric liquid crystal or the like that reflects only one of the left and right circularly polarized light is converted into linearly polarized light It is also used as an element.

Further, the retardation film has a function of converting linearly polarized light into elliptically polarized light or circularly polarized light, or converting linearly polarized light in a certain direction into another direction, and therefore, the viewing angle, contrast, etc. of the liquid crystal display device can be improved .

Generally, a retardation film is attached to a pair of polarizing plates, respectively. At present, N-TAC of Konica Minolta Holdings, Inc. of Japan is generally used as a phase difference film for a VA mode liquid crystal display. The NTAC retardation film was a cellulose acetate propionylate (CAP) having a retardation in the plane of 50 nm (retardation (R ₀ , relative to λ = 550 nm) and a retardation in the thickness direction (R _th , ) Film.

In order to improve the viewing angle characteristics (black display state (black characteristic), etc.) of the liquid crystal display device, wavelength dispersion and control techniques are required. In general, the N-TAC film exhibits an inverse wavelength dispersion characteristic in which the retardation value increases with increasing wavelength, and exhibits an excellent viewing angle characteristic improvement effect as compared with the retardation film having a regular wavelength dispersion characteristic in which the retardation value decreases with increasing wavelength. Further, in order to improve a liquid crystal display device, a retardation film having a specific retardation value and a combination thereof are used.

Conventional retardation films (PC, PSu, PA, etc.) have such characteristics that the longer the wavelength is, the smaller the retardation. It is difficult to impart an ideal retardation characteristic to the entire wavelength of the visible light region. So that necessary performance is obtained. In order to achieve such a performance in one phase difference film, it is preferable that the in-plane direction retardation (R _o ) at the wavelength λ incident on the retardation film is λ / 4, Plane directional phase difference (R _o ) increases as the wavelength becomes longer. In the film made of cellulose acetate, if such a retardation property can be given, the polarizing plate protective film and the retardation film can be used together, the retardation film composed of a plurality of retardation films can be omitted, It is possible to improve the total light transmittance.

With respect to this problem, Japanese Patent Laid-Open No. 2000-137116 proposes to use an oriented film of cellulose acetate having a degree of substitution (acetylation degree) of 2.5 to 2.8 as a retardation film. According to this method, the longer the wavelength, the larger the phase difference, and the ideal phase difference characteristic is obtained with respect to the entire wavelength of the visible light region. That is, the above-mentioned patent discloses a phase difference plate in which the phase difference becomes smaller as the measurement wavelength becomes shorter with one film. A retardation film comprising a polymeric orientation film having a longer birefringence (? N) at a wavelength of 400 to 700 nm, wherein the polymeric orientation film is an orientation film of a polymeric film having an average refractive index at the above- And the like. As a means for solving this problem, a technique of orienting cellulose acetate having an acetylation degree of 2.5 to 2.8 by stretching is disclosed.

In the embodiment of the above-mentioned patent, 100 parts by weight of cellulose triacetate having an intrinsic viscosity [?] = 1.335 and an acetylation degree of 2.917 obtained from Wako Junyaku Kogyo Co., Ltd. was dissolved in 500 parts by weight of methylene chloride, Hydrolysis of cellulose triacetate with acetic acid and water at 70 DEG C for 100 minutes while removing methylene chloride by depressurization and the reaction product was precipitated with a large amount of water and washed and dried , And a cellulose acetate having an acetylation degree of 2.661 was obtained. Then, a film was prepared from a solution prepared by dissolving 100 parts by weight of this polymer and 3 parts by weight of dibutyl phthalate as a plasticizer in 700 parts by weight of a mixed solvent of methylene chloride / methanol (weight ratio 9/1) by solvent casting method, And uniaxially stretched at a temperature of 170 캜 at 1.5 times. That is, in Embodiment 1 of the patent, the retardation film having the same wavelength characteristics (wavelength dispersion characteristics) as the latter is obtained by stretching. It is also disclosed that by adjusting the retardation value, it is possible to use? / 4 or another retardation film. In Example 4 of the aforementioned patent, cellulose acetate having an acetylation degree of 2.421 was obtained. When the retardation property of the film using the film is measured, the retardation is insufficient when the film thickness is about 100 mu m (50 to 150 mu m) and when the film thickness is preferable as the self-supporting film. Further, when thick enough and has a film thickness 200㎛ over to, the retardation (R _th) in the thickness direction at the time to provide a desired phase difference of about 80 to 150nm is more than 350nm, in the field of view when functioning as a λ / 4 phase difference film It did not function as an enlarged film and was not sufficient. Furthermore, the molecular weight distribution of the obtained cellulose acetate is not described, and the control of the retardation characteristics by controlling the molecular weight distribution is not described or suggested.

On the other hand, although the protective film of the polarizer PVA layer of the polarizing plate was produced by using materials such as TAC and acrylic, the raw materials added to the CAP, COP, and TAC at the time of manufacturing the retardation film are expensive, .

In addition, the cellulose-based polarizing plate made of the conventional retardation film is resistant to high-temperature and high-humidity environments, and the water resistance of the film is deteriorated when exposed to a high-temperature and high-humidity reliability environment, thereby lowering the reliability quality of the polarizing plate and OLED.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a liquid crystal coated retardation polarizer film for OLED capable of improving reliability quality by including a resin capable of improving high- .

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a liquid crystal coating layer; A liquid crystal coating base film; PVA film; And PVA protective films; , Wherein the liquid crystal coating base film comprises a cellulose ester having a degree of substitution in a range of 2.70 to 2.95 and an asymmetric ester compound having an aromatic group represented by the following formula (1) Film.

[Chemical Formula 1]

_{M A - [D O - D} A] n - D B

_{(Wherein, M A: R 1 -COOH,} D O: HO-R 2 -OH, D A: HOOC-R 1 -COOH, D B: a HO-R ₃ -OH, R ₁ is aryl having 6 or more R ₂ is a compound having 2 to 6 carbon atoms, propylene glycol, and R ₃ is a compound having 2 to 12 carbon atoms, which is an adipic acid residue or an aliphatic carboxylic acid residue or an akylene dicarboxylic acid residue, and n represents an integer of 1 or more.

At this time, it is preferable that the Vickers hardness defined by the following formula (1) is 20 HV or more for both surfaces, and that the liquid crystal coating film is oriented in the direction of 45 DEG +/- 10 DEG or 135 DEG +/- 10 DEG diagonal to the TD direction Do.

[Equation 1]

(Where F is the test load and d is the arithmetic mean of the two diagonal lengths d1 and d2).

The reflectance (R _M ) was measured in the directions of? = 45 ° and? = 45 ° before and after the liquid crystal coated retardation film polarizer film was left for 500 hours in a reliable environment at 60 ° C and 90% RH using a high temperature and high humidity chamber , It is preferable that the rate of change ΔR _M <3.0%.

The present invention having such a constitution has the effect of producing a liquid crystal coated retardation polarizing film for OLED excellent in reliability quality by including a resin capable of improving high temperature and high humidity reliability and an additive.

Fig. 1 is a view showing effective refractive index values of the effective surface area formed from nx, ny and nz when observed at the positions of [theta] = 45 [deg.] And [Phi] = 45 [
2 is a view showing a process for producing a cellulose ester according to the present invention.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto.

The liquid crystal coated phase difference polarizing film for OLED according to the present invention comprises a liquid crystal coating layer d1, a liquid crystal coating base film d2, a PVA film d3 and a PVA protective film d4 as shown in Fig. 1, The coating substrate film is characterized by comprising a cellulose ester.

Further, the cellulose ester film according to the present invention is characterized in that Vickers hardness defined by the following formula (1) is excellent in coating property and optical orientation property in a range of 20HV or more on both sides.

[Equation 1]

The acetyl group substitution degree of the cellulose ester is in the range of 2.70 to 2.95, and is characterized by including an asymmetric ester compound having an aromatic group represented by the following formula (1).

[Chemical Formula 1]

_{M A - [D O - D} A] n - D B

_{(Wherein, M A: R 1 -COOH,} D O: HO-R 2 -OH, D A: HOOC-R 1 -COOH, D B: a HO-R ₃ -OH, R ₁ is aryl having 6 or more R ₂ is a compound having 2 to 6 carbon atoms, propylene glycol, and R ₃ is a compound having 2 to 12 carbon atoms, which is an adipic acid residue or an aliphatic carboxylic acid residue or an akylene dicarboxylic acid residue, and n represents an integer of 1 or more.

The liquid crystal coated phase difference polarizing plate of the present invention has a reflectance (R _M ) in the directions of? = 45 ° and? = 45 ° before and after being left in a reliable environment of 60 ° C and 90% RH for 500 hours using a high temperature and high humidity chamber. , The rate of change? R _M &lt; 3.0% or less. The PVA protective film may be any one of TAC, COP, and Norbonne films.

Meanwhile, the cellulose ester phase difference film according to the present invention can be produced by solution casting method. In the solution film forming method, the cellulose ester is dissolved in an additive such as a plasticizer, a UV absorber, a matting agent, etc. and a mixed solvent such as methylene chloride and methanol to prepare a dope, which can be filtered using a filtration apparatus.

In the present invention, the molecular weight range of the cellulose ester is not limited, but the weight average molecular weight is preferably in the range of 150,000 to 220,000.

By reducing the molecular weight to a certain level or more, the strength of the film can be effectively prevented from being lowered.

Further, by keeping the molecular weight at a certain level or less, the viscosity of the cellulose ester solution (dope) is maintained at a certain level or less, thereby facilitating film production by solution casting method.

The degree of molecular weight dispersion (weight average molecular weight Mw / number average molecular weight Mn) of the cellulose ester is preferably in the range of 2.5 to 4.5.

When a film is produced by a solution film forming method (or a solvent casting method), an organic solvent is preferable as the solvent for preparing the cellulose ester composition (dope). As the organic solvent, it is preferable to use halogenated hydrocarbons, and halogenated hydrocarbons include chlorinated hydrocarbons, methylene chloride and chloroform, among which methylene chloride is most preferred.

If necessary, organic solvents other than halogenated hydrocarbons may be mixed and used. Organic solvents other than halogenated hydrocarbons include esters, ketones, ethers, alcohols and hydrocarbons. Examples of the ester include methyl formate, ethyl formate, propyl formate, pentyl formate, methyl acylate, ethyl acylate, and pentaacetate. Examples of the ketone include acetone, methyl ethyl ketone, diethyl ketone, di Isobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone and the like can be used. As the ether, diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, Ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-butanol and the like can be used. Methyl-2-butanol, cyclohexanol, 2-fluoroethanol, 2,2,2-trifluoroethanol and 2,2,3,3-tetrafluoro-1-propanol.

More preferably, methylene chloride may be used as the main solvent, and alcohol may be used as the minor solvent. Specifically, methylene chloride and alcohol may be mixed at a weight ratio of 80:20 to 95: 5.

The cellulose ester composition can be prepared by room temperature, high temperature or low temperature dissolution.

Next, the additives used in the production of the cellulose ester film will be explained. The cellulose ester solution (dope) used in the solution softening method may contain various additives depending on the application in each preparation step such as a plasticizer, a deterioration inhibitor, a matte fine particle, a stripper, a UV stabilizer, an ultraviolet absorber, An additive such as a dispersing agent, an optical anisotropy adjusting agent and the like may be added. The specific kind of such additives can be used without limitation as long as they are commonly used in the field, and the content thereof is preferably used within a range that does not deteriorate the physical properties of the film. The timing of adding the additives depends on the type of additive. A step of adding an additive to the end of the doping treatment may be performed.

The liquid crystal retardation film comprising the photo-orientable polymer of the present invention is oriented such that the liquid crystal alignment is oriented in the diagonal direction of 45 ° ± 10 ° or 135 ° ± 10 ° with respect to the TD direction of the cellulose ester film, is to measured at 23 ℃, 55% RH conditions, the total effective surface, which is defined by equation (2) is characterized in that the phase difference value Reff_ _total in the range of 70 to less than 210nm.

&Quot; (2) &quot;

_{Reff_ Total = Reff_ CEF [= (} n x1 '- n y1') × d1] + Reff_ LC [= (n x3 '- n y3') × d3]

(Wherein, Reff_ _CEF of n _x1 'and n _y1', Reff_ _LC of n _x3 'and n _y3' is the time, the cellulose ester film have been observed at θ = 45 ° & Φ = 45 ° position, as shown in to FIG. 1 refractive index n _x1, n _y1, n is the effective refractive index of the surface direction in which each value is formed from the n _{x3 z1,} n _{y3, z3} n of the liquid crystal coating layer, a retardation value in plane is Reff_ _total full effect.)

Here, the photo alignment layer of the present invention includes a polymer represented by the following formula (2), but the present invention is not limited thereto.

(2)

Wherein n is from 50 to 5,000 and p is an integer from 0 to 4, at least one of R 1, R 2, R 3, and R 4 is a radical and the others may be the same or different from each other and are independently hydrogen; A substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C2 to C20 alkenyl, a substituted or unsubstituted C2 to C12 cycloalkyl, a substituted or unsubstituted C6 to C40 aryl, A substituted or unsubstituted aralkyl having 7 to 15 carbon atoms, a substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, or a non-aromatic hydrocarbon having at least one element selected from the group consisting of oxygen, nitrogen, phosphorus, sulfur, A polar functional group selected from the group consisting of a non-hydrocarbonaceous polar group.

The liquid crystal coating layer of the present invention includes a liquid crystal structure represented by the following formula (3), but the present invention is not limited thereto.

(3)

(Wherein P is a polymerizable group containing an acrylate, methacrylate group or epoxy group, R20 is hydrogen or an alkyl group having 1 to 6 carbon atoms, and n is an integer of 1 to 10.)

On the other hand, the cellulose ester film contains a plasticizer for improving mechanical strength, good castability, imparting water absorbency, and reducing water permeability. As the plasticizer, any conventionally used plasticizer can be used without limitation. For example, carboxylic acid esters selected from phosphoric acid esters, phthalic acid esters or citric acid esters and the like can be used. In the present invention, the asymmetric Type ester plasticizer is particularly preferred in order to set the optical reliability characteristics of the cellulose ester film before and after the reliability treatment to a predetermined range.

Hereinafter, specific compounds of the asymmetric ester compound containing an aromatic group according to the present invention are shown through the following formulas (4) to (6), but the present invention is not limited thereto.

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

The cellulose ester solution thus obtained is cast on a support through a casting die to form a cellulose ester sheet.

The cellulose ester sheet thus formed is subjected to a stretching step in a tenter. In the preheating step, the glass transition temperature (Tg) of the cellulose ester flake is 185 to 200 ° C, the glass transition temperature (Tg) of the retardation film is 150 to 190 Lt; / RTI &gt;

The cellulose ester film of the present invention may be completed in a drying process in a dryer after removing the left and right ends of a film whose surface is damaged by a clip or pin of a tenter after being subjected to a stretching step in a tenter under the above conditions.

Example  One

<< Preparation of Cellulose Ester Film >>

&Lt; Step 1 > Cellulose solution ( Lead juice )

Triacetylcellulose having an average degree of acetyl substitution (DS) of 2.86 was used for the cellulose ester, and 5 kg of the terminal asymmetric plasticizer 1 (A) represented by the following chemical formula as a plasticizer (mass part-100 kg (parts by mass) To prepare a cellulose solution.

Terminal Asymmetric Plasticizer 1 (A) =

<Step 2> Preparation of Dilute Solution Containing Metal Oxide

20.0 parts by weight of the cellulose solution prepared in <Step 1>, 1.5 parts by weight of silica (SiO2), and 78.5 parts by weight of a mixed solvent obtained by mixing 9: 1 (by weight) of methylene chloride and methanol were added to a mixing tank, ) Was prepared. &Lt; tb &gt; &lt; TABLE &gt;

&Lt; Step 3 > Preparation of cellulose ester film

100 parts by mass of the initiator solution and 5 parts by mass of the fine particle additive solution were added, and sufficiently mixed with an inline mixer to prepare a dope. The composition of the dope was 72 wt% of methylene chloride, 8 wt% of methanol, 17.95 wt% of triacetylcellulose (TAC), 2 wt% of plasticizer (A + B + C), and 0.05 wt% of silica. Thereafter, the belt was softened uniformly on a stainless steel band support having a width of 2000 mm by using a flexible machine. Then, the solvent was evaporated on the stainless band support to peel off from the stainless band support. Then, both ends of the web were gripped with a tenter and stretched so that the stretching magnification in the (TD) direction in the temperature environment of 170 ° C was 1.1 times. Thereafter, the stretching was maintained for a few seconds while maintaining the width, , And the film was transported for 35 minutes in a drying section set at 110 캜 for drying for 35 minutes to produce a cellulose ester film having a thickness of 20.1 탆 and a knurling width of 1900 mm and a width of 10 mm and a height of 8 탆 at the end.

Example  2

The procedure of Example 1 was repeated to prepare a cellulose ester film, except that the film thickness was 30.1 탆.

Example  3

A cellulose ester film was produced in the same manner as in Example 1 except that the film thickness was changed to 40 탆.

Example  4

A cellulose ester film was prepared in the same manner as in Example 1, except that the amount of plasticizer added was changed to 10 kg (mass part - 100 kg (parts by mass)), and the film thickness was changed to 20.1 탆.

Example  5

A cellulose ester film was produced in the same manner as in Example 1, except that the amount of plasticizer added was changed to 10 kg (mass part - 100 kg (mass part)), and the film thickness was 30.1 탆.

Example  6

A cellulose ester film was produced in the same manner as in Example 1, except that the amount of plasticizer added was changed to 10 kg (mass part - 100 kg (parts by mass)) and the film thickness was changed to 40 탆.

Example  7

A cellulose ester film was produced in the same manner as in Example 1, except that the amount of plasticizer added was changed to 10 kg (mass part - 100 kg (parts by mass) to the amount of cellulose ester) and the film thickness was 25 탆.

Comparative Example  One

Except that 10 kg of the terminal symmetrical plasticizer 1 (B) represented by the following formula as a plasticizer (in terms of mass part-100 kg (mass part)) was used and the film thickness was set to 40 탆, To prepare a cellulose ester film.

Terminal symmetric plasticizer 1 (B) =

Comparative Example  2

Except that 10 kg of the terminal symmetrical plasticizer 2 (C) represented by the following formula as a plasticizer (in terms of mass part-100 kg (parts by mass)) was used and the film thickness was set to 40.1 탆, To prepare a cellulose ester film.

Terminal symmetric plasticizer 2 (C) =

Comparative Example  3

Except that 10 kg of the terminal symmetric plasticizer 3 (D) represented by the following chemical formula (as a plasticizer) (based on 100 parts by weight (parts by mass) of cellulose ester) was used and the film thickness was made 40 μm, To prepare a cellulose ester film.

Terminal symmetric plasticizer 3 (D) =

Experimental Example  One

The cellulose ester films prepared in Examples 1 to 7 and Comparative Examples 1 to 3 were measured for Vickers hardness on both sides of the air side and the Belt side using a Micro Vickers Hardness Tester (Mitutoyo HM-122) Vickers hardness tester Respectively.

The measurement results are shown in Table 1 below.

NO. cellulose
ester Plasticizer Type Film thickness
(탆) Vickers hardness (HV) Cellulose ester film NO Kinds Additive amount (kg) Kinds Additive amount (kg) Air plane Belt cotton Example 1 TAC 100 A 5 20.1 22.3 22.9 RF1 Example 2 TAC 100 A 5 30.1 21.4 21.8 RF2 Example 3 TAC 100 A 5 40 21.6 22.7 RF3 Example 4 TAC 100 A 10 20.1 22.3 22.7 RF4 Example 5 TAC 100 A 10 30.1 21.7 22.1 RF5 Example 6 TAC 100 A 10 40 21.5 22.1 RF6 Example 7 TAC 100 A 10 25 21.1 21.8 RF7 Comparative Example 1 TAC 100 B 10 40 18.8 18.9 RF8 Comparative Example 2 TAC 100 C 10 40.1 18.7 18.5 RF9 Comparative Example 3 TAC 100 D 10 40 19.1 19.2 RF10

As can be seen from Table 1, when the plasticizer proposed in the present invention is included, the cellulose ester film has excellent ΔReff characteristics before and after the reliability treatment, so that the optical reliability and the Vickers hardness of the film surface are excellent, It can be seen that it is excellent in strength and orientation.

Example  8

<< liquid crystal coating Phase difference  Manufacture of film >>

<Step 1> Photo-  formation

As the photo alignment layer, a photo-orientable polymer containing repeating units of the above formula (2) was used.

The photo alignment layer may be formed by applying a composition for the photo alignment layer comprising the photo-orientable polymer, the binder compound, the photo-initiator and the organic solvent onto the cellulose ester film RF-1 prepared above, And drying the applied solvent, and irradiating the applied composition with ultraviolet rays (UV). At this time, the photoinitiator may be any initiator known to initiate and promote UV curing, and in the present invention an initiator known as Irgacure 907 or 819 is used. The organic solvent may be optionally used to dissolve each of the above-mentioned components. Specific examples thereof include toluene, anisole, chlorobenzene, dichloroethane, cyclohexane, cyclohexane, cyclopentane or propylene glycol methyl ether acetate. Two or more mixed solvents selected from these may be used. In this embodiment, toluene is used as a solvent Respectively.

After applying the composition for photo-alignment layers containing the respective components selected above to the cellulose ester substrate, the organic solvent is selectively removed, and then at least a part or all of the photoreactive unit bonded to the photo- And the UV polymerization and / or curing of the binder compound is carried out to form a photo alignment film comprising a photo-oriented polymer in which the photo-reactive group is photo-aligned and, optionally, a cured product of the binder compound. Also, in the drying step of the solvent, the coating film is heated at about 50 to 250 ° C for about 20 to 90 minutes to dry the film to remove the solvent. In the ultraviolet ray irradiation step, Polarized ultraviolet light in the region of about 150 to 450 nm is irradiated with an energy of about 50 mJ / cm 2 to 10 J / cm 2, preferably about 500 mJ / cm 2 to 5 J / cm 2 to a thickness of about 10 to 1000 nm (PI-1) was prepared.

<Step 2> Coating film  formation

The liquid crystal layer on the photo alignment layer formed by the above method may include any liquid crystal compound known to be usable for the optically anisotropic film without any particular limitation. However, in consideration of better interaction with the photo-orientable polymer formed above, the liquid crystal compound of Formula 3 was used as the liquid crystal layer.

The liquid crystal layer was formed on the prepared photo alignment layer by a conventional method.

The liquid crystal of Formula 2 was coated by a slit nozzle method, dried at 60 ° C. for 2 minutes, and irradiated with ultraviolet rays of 50 mJ to cure the liquid crystal to form a liquid crystal coating layer having a thickness of 1.7 μm. Finally, a liquid crystal coated phase difference film was prepared.

Example  9

A cellulose ester film RF-2 and a liquid crystal coating film having a thickness of 1.6 탆 were used in place of the cellulose ester film RF-2.

Example  10

A cellulose ester film RF-3 and a liquid crystal coating film having a thickness of 1.6 mu m were used in place of the cellulose ester film RF-3.

Example  11

The procedure of Example 8 was repeated except that the cellulose ester film RF-4 was used to prepare a liquid crystal coated retardation film.

Example  12

A cellulose ester film RF-5 and a liquid crystal coating film having a thickness of 1.6 탆 were used in the same manner as in Example 8 to prepare a liquid crystal coated phase difference film.

Example  13

A cellulose ester film RF-6 and a liquid crystal coating film having a thickness of 1.6 탆 were used in place of the cellulose ester film RF-6.

Example  14

A cellulose ester film RF-7 and a liquid crystal coating film having a thickness of 1.6 탆 were used in the same manner as in Example 8 to prepare a liquid crystal coated retardation film.

Comparative Example  4

The procedure of Example 8 was repeated except that the cellulose ester film RF-8 was used to prepare a liquid crystal coated retardation film.

Comparative Example  5

Cellulose ester film RF-9 and a liquid crystal coating film having a thickness of 1.6 탆 were used in the same manner as in Example 8 to prepare a liquid crystal coated phase difference film.

Comparative Example  6

A cellulose ester film RF-10 and a liquid crystal coating film having a thickness of 1.6 탆 were used in place of the cellulose ester film RF-10.

Experimental Example  2

(1) In order to evaluate the liquid crystal alignability, the prepared liquid crystal coated retardation film was placed between two polarizing plates orthogonal to each other, and the uniformity of the transmitted light and the degree of alignment of the liquid crystal Respectively. The degree of orientation of the liquid crystal is shown by the following criteria, and the results of the evaluation of the liquid crystal orientation property are summarized in Table 3 below.

(2) The liquid crystal coated phase difference film prepared above was irradiated with a wavelength of 590 nm as a reference wavelength under the environment of 23 ° C and 55% RH using an optical measuring instrument of AxoScan (OPMF-1, Axometrics) = Φ to the entire effective surface measuring a phase difference value Reff _{_ total} direction in the 45 ° position are shown collectively in Table 3 below.

No cellulose
ester Photo- Liquid crystal coating film Orientation Reff_Total Kinds Thickness (um) Thickness (nm) Thickness (um) Example 8 RF1 20.1 700 1.7 ◎ 100.5 Example 9 RF2 30.1 700 1.6 ◎ 103.4 Example 10 RF3 40 700 1.6 ○ 90.3 Example 11 RF4 20.1 700 1.7 ◎ 106.4 Example 12 RF5 30.1 700 1.6 ◎ 103.5 Example 13 RF6 40 700 1.6 ◎ 107.5 Example 14 RF7 25 700 1.6 ○ 92.3 Comparative Example 4 RF8 40 700 1.7 △ 65.4 Comparative Example 5 RF9 40.1 700 1.6 △ 67.2 Comparative Example 6 RF10 40 700 1.6 X 57.3

◎. Very good orientation.

○. Good orientation.

△. Although orientation is observed, it is insufficient for practical use.

X. Almost no orientation was observed.

Example  15

<< liquid crystal coating Phase difference  Manufacture of Polarizing Film >>

Step 1: Polarizer  - PVA  Production of film

The polyvinyl alcohol film having a thickness of 120 占 퐉 was uniaxially stretched (at a temperature of 110 占 and a stretching magnification of 5 times).

This was immersed in an aqueous solution containing 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 at 68 DEG C containing 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 polarizer (PF-1).

Step 2: Preparation of Polarizer

According to the following steps 1 to 5, a PVA film having a thickness of 20 占 퐉 as the polarizer and a 40 占 퐉 TAC film having a thickness of 40 占 퐉 were used as the polarizer protective film. On the back side, A polarizing plate of the present invention was produced by using the film according to the following process.

Step 1 : The film was immersed in a 2 mol / L sodium hydroxide solution at 60 占 폚 for 90 seconds, followed by washing with water and drying to obtain a saponified cellulose ester film bonded to the polarizer.

Step 2 : The polarizing membrane was immersed in a polyvinyl alcohol adhesive tank (tank) having a solid content of 2 mass% for 1 to 3 seconds.

Step 3 : In step 2, excess glue adhered to the polarizing film was lightly wiped off, and placed on a cellulose ester film treated in step 1.

Step 4 : The cellulose ester film laminated in Step 3, the polarizer, and the back side cellulose ester film were bonded at a pressure of 20 to 30 N / cm 2 and at a conveying speed of about 2 m / min.

Step 5 : A sample obtained by bonding the polarizer prepared in Step 4 to the cellulose ester film and the back side cellulose ester film in a dryer at 80 占 폚 was dried for 2 minutes to prepare a polarizing plate (POL-1).

Example  16

A polarizing plate was produced in the same manner as in Example 15 except that a PVA film having a thickness of 20.1 占 퐉 and a liquid crystal coating film having a thickness of 31.6 占 퐉 were used as the polarizer.

Example  17

A polarizing plate was produced in the same manner as in Example 15 except that a liquid crystal coating retardation film having a thickness of 41.6 占 퐉 and a TAC film having a thickness of 40.1 占 퐉 were used as a polarizing plate protective film.

Example  18

A polarizing plate was produced in the same manner as in Example 15 except that a TAC film having a thickness of 40.1 占 퐉, a PVA film having a thickness of 20.2 占 퐉 as a polarizer, and a liquid crystal-coated phase difference film having a thickness of 21.6 占 퐉 were used as a polarizing plate protective film.

Example  19

A polarizing plate was produced in the same manner as in Example 15 except that a TAC film having a thickness of 40.1 占 퐉, a PVA film having a thickness of 20.1 占 퐉, and a liquid crystal-coated phase difference film having a thickness of 31.7 占 퐉 were used as the polarizing plate protective film.

Example  20

A polarizing plate was produced in the same manner as in Example 15 except that a PVA film having a thickness of 20.1 占 퐉 and a liquid crystal-coated phase difference film having a thickness of 41.6 占 퐉 were used as the polarizer.

Example  21

A polarizing plate was produced in the same manner as in Example 15 except that a TAC film having a thickness of 40.1 占 퐉, a PVA film having a thickness of 20.1 占 퐉, and a liquid crystal-coated phase difference film having a thickness of 26.5 占 퐉 were used as the polarizing plate protective film.

Comparative Example  7

A polarizing plate was produced in the same manner as in Example 15 except that a PVA film having a thickness of 20.1 占 퐉 as a polarizer and a liquid crystal coating retardation film having a thickness of 41.8 占 퐉 were used.

Comparative Example  8

A polarizing plate was produced in the same manner as in Example 15 except that a TAC film having a thickness of 40.1 占 퐉, a PVA film having a thickness of 20.2 占 퐉, and a liquid crystal-coated phase difference film having a thickness of 41.6 占 퐉 were used as the polarizing plate protective film.

Comparative Example  9

A polarizing plate was produced in the same manner as in Example 15 except that a TAC film having a thickness of 40.1 占 퐉, a PVA film having a thickness of 20.1 占 퐉, and a liquid crystal-coated phase difference film having a thickness of 41.6 占 퐉 were used as the polarizing plate protective film.

Experimental Example  3

The polarizing plate thus prepared was coated with a pressure-sensitive adhesive on the liquid crystal coating surface and laminated on a mirror glass substrate having a thickness of 0.5 mm. In this state, the reflectance was measured at the lateral azimuthal viewing position using an EZ-contrast three-dimensional measuring instrument (Eldim, France) optical measuring instrument under the environment of 23 ° C. and 55% RH.

The polarizing plate laminated to the mirror glass was allowed to stand for 500 hours in a reliable environment of 60 ° C. and 90% RH using a high temperature and high humidity chamber, then taken out from the high temperature and high humidity chamber, To measure the reflectance before and after the reliability environmental treatment.

The measurement results are shown in Table 3 below.

Polarizer protective film PVA film Liquid crystal coating film Reliability Before / After Reflectance (%) Kinds Thickness (um) Kinds Thickness (um) Kinds Thickness (um) Before processing After processing Variation Example 15 TAC-1 40 PF-1 20 L-RF1 21.4 6.5 8.2 1.7 Example 16 TAC-1 40 PF-1 20.1 L-RF2 31.6 6.9 8.8 1.9 Example 17 TAC-1 40.1 PF-1 20 L-RF3 41.6 7.1 9.6 2.5 Example 18 TAC-1 40.1 PF-1 20.2 L-RF4 21.6 6.8 8.7 1.9 Example 19 TAC-1 40.1 PF-1 20.1 L-RF5 31.7 7.5 9.1 1.6 Example 20 TAC-1 40 PF-1 20.1 L-RF6 41.6 7.1 9.2 2.1 Example 21 TAC-1 40.1 PF-1 20.1 L-RF7 26.5 6.7 8.9 2.2 Comparative Example 7 TAC-1 40 PF-1 20.1 L-RF8 41.8 8.1 12.2 4.1 Comparative Example 8 TAC-1 40.1 PF-1 20.2 L-RF9 41.6 9.8 13.4 3.6 Comparative Example 9 TAC-1 40.1 PF-1 20.1 L-RF10 41.6 10.2 15.3 5.1

As can be seen from Table 3 above, the composition of the liquid crystal coated phase difference protection film of the present invention, particularly the liquid crystal coated base film, is excellent in anti-wet heat properties in a high temperature and high humidity environment, It can be seen that the reliability of the reflectance before and after the reliability treatment of the polarizing plate is excellent.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It will be easy for anyone to know.

Claims (3)

A liquid crystal coating layer; A liquid crystal coating base film; PVA film; And PVA protective films; / RTI &gt;
Wherein the liquid crystal coating base film comprises a cellulose ester having a degree of substitution in the range of 2.70 to 2.95 and an asymmetric ester compound having an aromatic group represented by the following formula (1).
[Chemical Formula 1]
_{M A - [D O - D} A] n - D B
_{(Wherein, M A: R 1 -COOH,} D O: HO-R 2 -OH, D A: HOOC-R 1 -COOH, D B: a HO-R ₃ -OH, R ₁ is aryl having 6 or more R ₂ is a compound having 2 to 6 carbon atoms, propylene glycol, and R ₃ is a compound having 2 to 12 carbon atoms, which is an adipic acid residue or an aliphatic carboxylic acid residue or an akylene dicarboxylic acid residue, and n represents an integer of 1 or more.
The method according to claim 1,
Wherein the liquid crystal coating material film has a Vickers hardness of 20HV or more as defined by the following formula (1) and a liquid crystal alignment in a diagonal direction of 45 DEG +/- 10 DEG or 135 DEG +/- 10 DEG with respect to the TD direction A liquid crystal coated phase difference polarizer film for OLED comprising a photo-orientable polymer.
[Equation 1]

(Where F is the test load and d is the arithmetic mean of the two diagonal lengths d1 and d2).
The method according to claim 1,
When the reflectance (R _M ) was measured in the directions of? = 45 ° and? = 45 ° before and after the liquid crystal coated retardation film polarizer film was left for 500 hours in a reliable environment at 60 ° C and 90% RH using a high temperature and high humidity chamber And a rate of change ΔR _M <3.0%.

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