TWI609918B - Norbornene-based retardation film, and polarizing plate and display device using the same - Google Patents

Abstract

The present invention relates to a norbornene-based retardation film, a polarizing plate and a display device using the same, and more particularly to a norbornene-based retardation film comprising one of the following Chemical Formula 1 plasticizing , wherein R _o as shown in the equation 1 is 10 to 400 nm, and R _th is 50 to 500nm. The norbornene-based film of the present invention achieves excellent retardation and, therefore, can be used as an antireflection retardation film for OLEDs, and a VA retardation film.

[Chemical Formula 1] BG-PG-AG-B wherein B is a benzoic acid residue, P is a decanoic acid residue of 8 to 10 carbon atoms, G is a propylene glycol, and A is an adipic acid of 6 to 10 carbon atoms. Residues.

[Math 1] R _o = (n _{x -} n _y ) × d R _th = {(n _x + n _y ) / 2 - n _z } × d where d is the thickness (nm) of the film, and n _x is The horizontal maximum refractive index in the surface of the film, n _y is the maximum refractive index in the vertical direction of the film surface, n _z is the maximum refractive index in the thickness direction of the film, and each value is in the environment of 23 ° C and 55% RH. Measured at a wavelength of 550 nm.

Description

Norbornene-based retardation film, polarizing plate, and display device using the same

The present invention relates to a norbornene-based retardation film, and a polarizing plate and a display device using the same.

The norbornene-based resin exhibits excellent performance in heat resistance, optical properties, transparency, electrical properties, and the like, and has excellent dimensional stability, which is different from the existing cellulose film, and therefore, It is desirable to use it as a polarizing protective film or a retardation plate used in a polarizing plate.

Regarding an optical film using a norbornene-based resin, the related prior art can be understood by referring to the following Patent Documents 1 and 2.

Patent Document 1 discloses a thermoplastic saturated norbornene-based resin film formed by using a thermoplastic saturated norbornene-based resin composition comprising 100 parts by weight of a thermoplastic saturated norbornene. The main resin and 5 to 40 parts by weight of a viscous polymer have a parallel light transmittance of 87% or more.

Patent Document 2 discloses a norbornene-based polymer film which can be oriented at an industrially suitable temperature and exhibits a wide range delay.

Conventional technical documents Patent document

(Patent Document 1) WO2004/035688A (2004.04.29.)

(Patent Document 2) KR10-2008-0011074A (2008.01.31.)

The norbornene-based resin optical film has the advantage of having very high retardation sensitivity, but has the disadvantage of having a very small percentage of orientation compared to current cellulose-based optical films.

Therefore, the problem of the norbornene-based resin optical film is that retardation is exhibited in the high retardation film produced by high guiding due to the limitation of the guiding property.

It is an object of the present invention to provide a norbornene-based retardation film which can be used for preparing a high retardation film for OLEDs, a VA retardation film, and an aqueous phase by adding an additive which improves the guiding property. The adhesive process can be used to prepare a polarizing plate, and a polarizing plate and a display device using the polarizing plate.

The present invention has focused on the problems of the existing art, to provide retardation film comprising norbornene (norbornene) based, which comprises one of the following Chemical Formula 1 a plasticizer, as shown in Equation 1 wherein R _o of 10 to 400nm And R _th is 50 to 500 nm.

[Chemical Formula 1] B-G-PG-AG-B

Wherein B is a benzoic acid residue, P is a decanoic acid residue of 8 to 10 carbon atoms, G is a propylene glycol, and A is an adipic acid residue of 6 to 10 carbon atoms.

[Math 1] R _o =(n _x -n _y )×d R _th ={(n _x +n _y )/2-n _z }×d

Where d is the thickness (nm) of the film, n _x is the horizontal maximum refractive index in the surface of the film, n _y is the maximum refractive index in the vertical direction of the film surface, and n _z is the maximum refractive index in the thickness direction of the film, and each The values were measured at a wavelength of 550 nm in an environment of 23 ° C and 55% RH.

Further, in the norbornene-based retardation film provided by the present invention, the content of the plasticizer is in the range of 1 to 15% by weight based on the total weight.

Furthermore, the norbornene-based retardation film provided by the present invention further comprises one or more types of plasticizers selected from the group consisting of triphenyl phosphate, phthalate ester, dimethyl phthalate, and hydrazine. Diethyl acid, and diphenyl phthalate.

Further, the application of the norbornene-based retardation film of the present invention is a retardation film for improving the viewing angle of the VA type LCD, or an anti-reflection retardation film for an OLED.

Furthermore, the present invention provides a polarizing plate comprising the film of the present invention.

Further, the present invention provides a display device comprising the polarizing plate of the present invention.

Hereinafter, the present invention will be described in detail.

The present invention provides a retardation film comprising a norbornene-based, which comprises one of the following Chemical Formula 1 a plasticizer, wherein R _o as shown in the Equation 1 is 10 to 400 nm, and R _th is 50 to 500nm.

[Chemical Formula 1] B-G-PG-AG-B Wherein B is a benzoic acid residue, P is a decanoic acid residue of 8 to 10 carbon atoms, G is a propylene glycol, and A is an adipic acid residue of 6 to 10 carbon atoms.

[Math 1] R _o =(n _x -n _y )×d R _th ={(n _x +n _y )/2-n _z }×d

Where d is the thickness (nm) of the film, n _x is the horizontal maximum refractive index in the surface of the film, n _y is the maximum refractive index in the vertical direction of the film surface, and n _z is the maximum refractive index in the thickness direction of the film, and each The values were measured at a wavelength of 550 nm in an environment of 23 ° C and 55% RH.

Preferably, the plasticizer is present in an amount between 1 and 15% by weight based on the total weight.

Further, in the present invention, in addition to the plasticizer of Chemical Formula 1, the plasticizer widely used in the prior art may be further added, that is, one or more plasticizers, which are mainly free phosphates. a carboxylic acid ester-based, decanoic acid-based, and phosphoric acid-based plasticizer, and non-limiting examples may include one or more plasticizers selected from the group consisting of triphenyl phosphate and triphenyl phosphate. Acid ester Dimethyl acrylate, diethyl decanoate, and diphenyl phthalate.

The film of the present invention can exhibit high retardation and, therefore, is very suitable It is used as a retardation film to improve the viewing angle of the VA mode LCD (even for a retardation film of the 1 VA mode type and a retardation film of a 2 VA mode type), or as an antireflection retardation film of an OLED.

Another feature of the present invention is to provide a polarizing plate, including The retardation film of the present invention, and a display device comprising the polarizing plate.

In addition to the retardation film of the present invention, the polarizing plate and the display device of the present invention can be freely used without any of the other components conventionally used, as long as the object of the present invention is not impaired. The prior art relating to polarizing plates and display devices is apparent to those skilled in the art and, therefore, is not described in detail herein.

Hereinafter, the present invention will be described in detail with reference to the embodiments. However, it is to be understood that the following examples are provided to illustrate the invention, but are not intended to limit the scope of the invention.

Example

Preparation of norbornene-based film

A norbornene-based polymer resin, a plasticizer compound of the following Chemical Formula 2, and a solvent (dichloromethane:methanol = 9:1) were placed in a mixing tank and stirred to completely dissolve. A dissolved dope solution was used to prepare a retardation film. The resultant was oriented at a guiding temperature of 100 ° C and then dried (40 minutes) at a drying temperature of 110 ° C to obtain a final retardation film. The thickness of the film was 40 μm.

[Chemical Formula 2]

Comparative example

A film was prepared in the same manner as in the examples except that no plasticizer compound was added.

Test Example - [Evaluation of Guided Properties of Delayed Films]

The films prepared in the examples and comparative examples were evaluated for guiding properties. The guiding properties are evaluated as a percentage of the maximum guiding of the retarding film until it ruptures. Here, the guiding system was carried out at a temperature of 100 ° C, and the retardation value was measured using an Axoscan apparatus.

The results are shown in Table 1 below.

As shown in Table 1, when the plasticizer of Chemical Formula 2 is used, Excellent retardation performance can be obtained, and as a result, excellent use for OLEDs can be prepared. Delay film and VA retardation film.

The norbornene-based film of the present invention exhibits excellent elongation Late, therefore, it can be used as an anti-reflection retardation film for OLEDs, and a VA retardation film.

Claims (6)

A norbornene-based retardation film comprising a plasticizer of the following Chemical Formula 1, wherein R _o of the formula 1 is 10 to 400 nm, and R _th is 50 to 500 nm: [Chemical Formula 1] BG-PG-AG-B wherein B is a benzoic acid residue, P is a decanoic acid residue of 8 to 10 carbon atoms, G is propylene glycol, and A is an adipic acid residue of 6 to 10 carbon atoms; [Math 1] R _o = (n _{x -} n _y ) × d R _th = {(n _x + n _y ) / 2 - n _z } × d where d is the thickness (nm) of the film, and n _x is The horizontal maximum refractive index in the surface of the film, n _y is the maximum refractive index in the vertical direction of the film surface, n _z is the maximum refractive index in the thickness direction of the film, and each value is in the environment of 23 ° C and 55% RH. Measured at a wavelength of 550 nm. The norbornene-based retardation film according to claim 1, wherein the plasticizer is contained in an amount of from 1 to 15% by weight based on the total weight. The norbornene-based retardation film according to claim 1, further comprising one or more types of plasticizers selected from the group consisting of triphenyl phosphate, phthalic acid ester, dimethyl phthalate, and hydrazine. Diethyl acid, and diphenyl phthalate. An application of the norbornene-based retardation film according to any one of claims 1 to 3, which is a retardation film for improving the viewing angle of a VA type LCD, or for an OLED. Primary anti-reflection delay film. A polarizing plate comprising the film according to any one of claims 1 to 3. A display device comprising the polarizing plate as described in claim 5 of the patent application.