KR20150054209A - Polymer for optical film, and optical film including same - Google Patents

Abstract

The present invention relates to a composition for manufacturing optical films, including carboxylic acid diabhydride denoted by chemical formula 1, diamine denoted by chemical formula 2 and diamine denoted by chemical formula 3 wherein at least 5 mol% of the diamine denoted by chemical formula 3 is included in the composition. NH_2-R_2-NH_2 is chemical formula 2.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer for an optical film, and an optical film containing the polymer. [0002]

A polymer for an optical film, and an optical film containing the same.

A flat panel display device, which is mainly used at present, can be divided into a light emitting display device which emits light by itself and a light receiving display device which requires a separate light source. Optical compensation films such as a retardation film are frequently used do.

In the case of a light emitting display device, for example, an organic light emitting display (OLED), visibility and contrast ratio may be lowered due to reflection of external light by a metal such as an electrode. In order to reduce this, the polarizing plate and the retardation film are used to prevent the external light reflected by the organic light emitting display device from leaking out.

In a liquid crystal display (LCD) as a light receiving display device, elliptically polarized light is generated due to the birefringence of the liquid crystal and the orthogonal polarizer, and accordingly, the contrast ratio may decrease and the color may change. The optical compensation film improves the image quality by changing the elliptical polarization to circular polarization. In the case of a liquid crystal display device, in particular, the thickness of the device becomes thicker due to the thickness of the liquid crystal, and thus the thickness direction retardation (Rth) becomes more problematic than the in-plane retardation Re.

On the other hand, there is a need for a flexible display that is thin and lightweight, low in power, light in weight and flexible, and free from any place or time, as a display that visualizes various information in accordance with intensification and popularization of information, It is gradually increasing. In order to realize a flexible display, flexible substrates, organic and inorganic materials for low-temperature processes, flexible electronics, encapsulation and packaging technologies are required in combination. Among them, the flexible substrate is the most important part for determining the performance, reliability and price of the flexible display.

Plastic substrates are useful as flexible substrates because they are easy to process and are low weight and suitable for continuous processing. However, plastic substrates are inherently poor in thermal stability, so physical properties must be improved for practical applications.

Accordingly, colorless and transparent materials having high temperature stability, a low coefficient of thermal expansion (CTE), high mechanical properties, and low optical anisotropy, which can be used as optical films, are required.

One embodiment is to provide a composition for producing an optical film having high temperature stability, transparency, and low optical anisotropy.

Another embodiment is to provide a polymer having high temperature stability, transparency, and low optical anisotropy.

Another embodiment is to provide an optical film produced from the composition or the polymer having high temperature stability, transparency, and low optical anisotropy.

Another embodiment is to provide an optical device comprising the optical film.

One embodiment includes a tetracarboxylic acid dianhydride represented by the following formula (1), a diamine represented by the following formula (2), and a diamine represented by the following formula (3), wherein the diamine represented by the following formula And 5 mol% or more of the composition:

(Formula 1)

(2)

NH ₂ -R ₂ -NH ₂

(Formula 3)

In Formula 1 and Formula 2, R ₁ and R ₂ each independently represent a substituted or unsubstituted C 4 to C 20 aliphatic cyclic group, or a substituted or unsubstituted C 6 to C 30 aromatic organic group, Either alone; Two or more are bonded to each other to form a condensed ring; Or two or more aromatic rings may be substituted by a single bond or a fluorenylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C15 arylene group, -O-, -S-, -C = O) -, -CH (OH ) -, -S (= O) 2 -, -Si (CH 3) 2 -, - (CH 2) p - ( where, 1≤p≤10), - (CF ₂ ) _q -, where ₁ ? _Q ? 10, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, or -C (= O) NH-.

In Formula 3, R ₃ to R ₆ are each independently a C1 to C20 alkyl group, a C6 to C20 aryl group, or a halogen group (F, Cl, Br, I) To n4 are each an integer of 0 to 4;

The diamine of the above formula 3 may be used in an amount of 5 mol% or more, for example, 7 mol% or more, for example, 10 mol% or more, for example, 20 mol% or more, for example, 30 mol% or more, For example, in an amount of 40 mol% or more, for example, 50 mol% or more.

The tetracarboxylic acid dianhydride of Formula 1 may be selected from the group consisting of 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride (BPDA), 3,3', 4,4'-biphenyl tetracarboxylic dianhydride (2.2.2) oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (bicyclo [2.2.2] oct- BTDA), 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA), 4,4' - (hexafluoro Hexafluoroisopropylidene diphthalic anhydride (6FDA), 4,4'-oxydiphthalic anhydride (ODPA), pyromellitic dianhydride Pyromellitic dianhydride (PMDA), and 4 - ((2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetra naphthalene-1,2-dicarboxylate (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid naphthalene, naphthalene, naphthalene, naphthalene, naphthalene, naphthalene, naphthalene,

The diamine of formula (2) may be at least one selected from the group consisting of compounds represented by the following formulas:

In the above formulas,

R ³² to R ⁵² are the same or different from each other and each independently represents a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted C1 to C15 alkyl group, a substituted or unsubstituted C1 to C15 alkoxy group, a substituted or unsubstituted C1 A substituted or unsubstituted C3 to C15 cycloalkyl group, a substituted or unsubstituted C3 to C15 heterocycloalkyl group, a substituted or unsubstituted C3 to C15 oxycycloalkyl group, a substituted or unsubstituted C6 to C15 aryl A substituted or unsubstituted C6 to C15 oxyaryl group, or a substituted or unsubstituted C2 to C15 heteroaryl group,

X ² to X ¹² are the same or different from each other and each independently represents a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C15 An arylene group, -SO ₂ -, -O-, -CO-, or a combination thereof,

n35 to n37, and n40 to n49 are any of integers of 0 to 4,

n38 and n39 are each an integer of 0 to 3;

The diamine may be at least one selected from the compounds represented by the following formulas:

R ₃ to R ₆ in Formula 3 may each independently be the same or different methyl, ethyl, propyl, butyl, phenyl, or halogen groups (F, Cl, Br, I). In one example, R ₃ to R ₆ are all methyl groups, and n ₁ to n ₄ may be all 1s.

As another example, n ₁ to n ₄ may all be zero.

In another embodiment, there is provided a polymer comprising a combination of the following Formula 4, Formula 5, or Formula 4 and Formula 5:

(Formula 4)

(Formula 5)

In the above formulas (4) and (5)

The definitions of R ₁ to R ₆ , and n ₁ to n ₄ are the same as those defined in the above Chemical Formulas 1 to 3,

x and y are mole fractions of the respective repeating units in the polymer, and 0.05? x <1 and y = 1-x.

The polymer of formula (5) can be prepared by chemically or thermally curing the polymer of formula (4).

In another embodiment, there is provided an optical film produced from the composition or the polymer.

The optical film may have a thickness direction retardation (Rth) of about 500 nm or less based on a film thickness of about 0.1 mu m to about 200 mu m.

The optical film may have an average transmittance of about 80% or more at 380 nm to 800 nm when measuring transmittance with a UV spectrometer based on a film thickness of about 0.1 탆 to about 200 탆.

The optical film may have a Yellowness value of about 20 or less based on a film thickness of about 0.1 mu m to about 200 mu m.

In another embodiment, an optical device comprising the optical film is provided.

The optical device may be a liquid crystal display (LCD) device, an organic light emitting diode (OLED) device, or a complementary metal oxide semiconductor (CMOS) sensor.

According to the embodiment of the present invention, an optical film having high temperature stability, excellent optical properties, and low optical anisotropy can be obtained.

FIG. 1 is a graph showing light transmittance of the polyimide film according to Comparative Example 1 and Examples 1 to 4 in the entire wavelength range. FIG.
FIG. 2 is a graph showing the thickness direction retardation value Rth according to the BAPF content of the polyimide film according to Comparative Example 1 and Examples 1 to 4.
3 is a graph showing changes in weight of the polyimide film according to Comparative Example 1 and Examples 1 to 4 with temperature.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

Unless otherwise specified herein, "substituted" or "substituted" means that at least one hydrogen atom of the functional group of the present invention is substituted with a halogen atom (-F, -Cl, -Br, or -I), a hydroxyl group, , a cyano group, an amino group ^{_{(NH 2, NH (R 100}} ) , or ^{N (R 101) (R 102} ) , wherein R ^100, R ¹⁰¹ and R ¹⁰² are the same or different, each independently represent a C1 to C10 alkyl group, A substituted or unsubstituted alkyl group, a substituted or unsubstituted alicyclic group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, Substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted heterocyclic group, and the substituents are substituted with each other Connected to form a loop There is also.

Unless otherwise specified in the specification, "alkyl group" means C1 to C30 alkyl group, specifically C1 to C15 alkyl group, "cycloalkyl group" means C3 to C30 cycloalkyl group, specifically C3 Refers to a C1 to C30 alkoxy group, specifically a C1 to C18 alkoxy group, and an "ester group" means a C2 to C30 ester group, specifically, a C2 to C30 cycloalkyl group, Quot; means a C2 to C30 ketone group, specifically, a C2 to C18 ketone group, and the "aryl group" means a C6 to C30 aryl group, specifically, a C6 to C18 aryl Quot; alkenyl group " means a C2 to C30 alkenyl group, specifically, a C2 to C18 alkenyl group, an "alkylene group" means a C1 to C30 alkylene group, By volume means a C1 to C18 alkylene, and, means a C6 to C30 arylene term "aryl group", and specifically, means a C6 to C16 arylene.

Unless otherwise specified in the present specification, the term "aliphatic organic group" means a C1 to C30 alkyl group, a C2 to C30 alkenyl group, a C2 to C30 alkynyl group, a C1 to C30 alkylene group, a C2 to C30 alkenylene group, Means a C1 to C15 alkyl group, a C2 to C15 alkenyl group, a C2 to C15 alkynyl group, a C1 to C15 alkylene group, a C2 to C15 alkenylene group, or a C2 to C15 alkynylene group, Means a C3 to C30 cycloalkyl group, a C3 to C30 cycloalkenyl group, a C3 to C30 cycloalkynyl group, a C3 to C30 cycloalkylene group, a C3 to C30 cycloalkenylene group, or a C3 to C30 cycloalkynylene group. C3 to C15 cycloalkenyl groups, C3 to C15 cycloalkynyl groups, C3 to C15 cycloalkylene groups, C3 to C15 cycloalkenylene groups, Means a C6 to C30 aryl group or a C6 to C30 arylene group, specifically, a C6 to C16 aryl group or a C6 to C16 arylene group, and the term " aromatic hydrocarbon group " The "heterocyclic group" means a C2 to C30 heterocycloalkyl group containing 1 to 3 hetero atoms selected from the group consisting of O, S, N, P, Si and combinations thereof in one ring, C2 to C30 C2 to C30 heterocycloalkenyl groups, C2 to C30 heterocycloalkylene groups, C2 to C30 heterocycloalkenyl groups, C2 to C30 heterocycloalkenylene groups, C2 to C30 heterocycloalkynyl groups, C2 to C30 heterocycloalkynylene groups, C2 to C30 heteroaryl groups , Or a C2 to C30 heteroarylene group, specifically, a heteroatom selected from the group consisting of O, S, N, P, Si, and combinations thereof, C2 to C15 heterocycloalkylene groups, C2 to C15 heterocycloalkylene groups, C2 to C15 heterocycloalkylene groups, C2 to C15 heterocycloalkenyl groups, C2 to C15 heterocycloalkenylene groups, C2 to C15 heterocycloalkynyl groups, C2 To C15 heterocycloalkynylene groups, C2 to C15 heteroaryl groups, or C2 to C15 heteroarylene groups.

"Combination" as used herein, unless otherwise specified, means mixing or copolymerization. Here, "copolymerization" means random copolymerization, block copolymerization or graft copolymerization.

In the present specification, "*" means the same or different atom or part connected to a chemical formula.

A tetracarboxylic acid dianhydride represented by the following formula (1), a diamine represented by the following formula (2), and a diamine represented by the following formula (3), wherein the diamine represented by the following formula Which comprises:

(Formula 1)

(2)

NH ₂ -R ₂ -NH ₂

(Formula 3)

In Formula 1 and Formula 2, R ₁ and R ₂ each independently represent a substituted or unsubstituted C 4 to C 20 aliphatic cyclic group, or a substituted or unsubstituted C 6 to C 30 aromatic organic group, Either alone; Two or more are bonded to each other to form a condensed ring; Or two or more aromatic rings may be substituted by a single bond or a fluorenylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C15 arylene group, -O-, -S-, -C = O) -, -CH (OH ) -, -S (= O) 2 -, -Si (CH 3) 2 -, - (CH 2) p - ( where, 1≤p≤10), - (CF ₂ ) _q -, where ₁ ? _Q ? 10, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, or -C (= O) NH-.

In Formula 3, R ₃ to R ₆ are each independently a C1 to C20 alkyl group, a C6 to C20 aryl group, or a halogen group (F, Cl, Br, I) n4 are each an integer of 0 to 4;

As can be seen from the examples described later, the thickness direction retardation (Rth) at a thickness of about 10 mu m of the film made from the composition, particularly the composition containing about 10 mol% of the diamine represented by the formula (3) And Rth is 340 nm when the diamine of Formula 3 is contained in an amount of about 30 mol%, and Rth is decreased to 200 nm when the diamine of Formula 3 is included in an amount of 50 mol%.

When the thickness direction retardation (Rth) is 500 nm or less, it can be used as a compensation film.

When light is transmitted through a transparent film or the like, a retardation (R) is generated due to a difference in speed of light oscillating in the plane direction and the thickness direction, that is, a difference in refractive index. The larger the retardation value, It becomes impossible. Particularly, as the length of the thickness direction in which light passes through due to the thickness of the liquid crystal, such as a liquid crystal display (LCD), becomes large, the retardation value (Rth) in the thickness direction becomes large. The thickness direction retardation Rth can be calculated by the following equation (1): &lt; EMI ID =

( Equation  One)

             Rth = (ne-no) xd

In the above equation (1), Rth represents retardation in the thickness direction, ne represents the refractive index in the plane direction, no represents the refractive index in the thickness direction, and d represents the thickness of the device through which light passes.

That is, as the thickness of the film or the apparatus through which light passes becomes larger, the retardation value in the thickness direction becomes larger.

In the case of the film prepared from the composition for an optical film according to the embodiment, as described above, the retardation (Rth) in the thickness direction of the film can be controlled according to the content of the diamine represented by the formula (3) For example about 10 mol% or more, for example about 20 mol% or more, such as about 30 mol% or more, for example, about 5 mol% or more, for example about 7 mol% And more than about 40 mol%, for example, about 50 mol% or more, the retardation Rth in the film thickness direction is further reduced as the content is increased.

Therefore, an optical film such as a compensating film can be prepared from the composition containing the above-mentioned formula (3) in an amount of about 5 mol% or more of the total diamine. In addition, when the composition is used as a transparent substrate such as a display device, the substrate serves as a compensation film, so that no compensation film is required in the display device.

Thus, for example, when preparing a compensation film, the diamine of Formula 3 in the composition may comprise at least about 5 mol%, such as at least about 7 mol%, such as at least about 10 mol% For example, at least about 20 mole percent, such as at least about 30 mole percent, such as at least about 40 mole percent, such as at least about 50 mole percent.

In the above composition, the tetracarboxylic dianhydride of Formula 1 may be prepared by reacting 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride (BPDA ), Bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (bicycle [2.2.2] oct- tetracarboxylic dianhydride (BTDA), 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA), 4,4' - Hexafluoroisopropylidene diphthalic anhydride (6FDA), 4,4'-oxydiphthalic anhydride (ODPA), hexafluoroisopropylidene anhydride, Pyromellitic dianhydride (PMDA), and 4 - ((2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetranaphthalene- 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphtha lene-1,2-dicarboxylic anhydride, DTDA).

In one embodiment, the tetracarboxylic dianhydride is 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride (BPDA), 3,3', 4,4'- And / or pyromellitic dianhydride (PMDA).

The diamine of formula (2) may be at least one selected from the group consisting of compounds represented by the following formulas:

In the above formulas,

R ³² to R ⁵² are the same or different from each other and each independently represents a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted C1 to C15 alkyl group, a substituted or unsubstituted C1 to C15 alkoxy group, a substituted or unsubstituted C1 A substituted or unsubstituted C3 to C15 cycloalkyl group, a substituted or unsubstituted C3 to C15 heterocycloalkyl group, a substituted or unsubstituted C3 to C15 oxycycloalkyl group, a substituted or unsubstituted C6 to C15 aryl A substituted or unsubstituted C6 to C15 oxyaryl group, or a substituted or unsubstituted C2 to C15 heteroaryl group,

X ² to X ¹² are the same or different from each other and each independently represents a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C15 An arylene group, SO ₂ , O, CO, or a combination thereof,

n35 to n37, and n40 to n49 are any of integers of 0 to 4,

and n38 and n39 are any of an integer of 0 to 3.

The diamine may be at least one selected from the compounds represented by the following formulas:

In one embodiment, the diamine may be 2,2'-bis (trifluoromethyl) benzidine (TFDB).

R ₃ to R ₆ in Formula 3 are each independently selected from the group consisting of C1 to C4 alkyl such as methyl, ethyl, propyl, isopropyl, or butyl, phenyl, or a halogen group (F, Cl, Br, I). As an example, R ₃ to R ₆ in the general formula (3) are all methyl groups, and n ₁ to n ₄ may all be 1.

As another example, when n &lt; _{1 &gt;} To n ₄ May all be zero.

In another embodiment, there is provided a polymer comprising a combination of the following Formula 4, Formula 5, or Formula 4 and Formula 5:

(Formula 4)

(Formula 5)

In the general formulas (4) and (5), the definitions of R ₁ to R ₆ , and n ₁ to n ₄ are the same as those defined for the general formulas (1) to (3)

x and y are mole fractions of the respective repeating units in the polymer, and 0.05? x <1 and y = 1-x.

In the general formulas (4) and (5), R 1 may be a group derived from the tetracarboxylic dianhydride of the general formula (1), and R 2 may be a group derived from the diamine of the general formula (2).

In one embodiment, the R &lt; _{1 &gt;} And R &lt; ₂ &gt; may each be a group represented by the following formula:

X <1, for example 0.07 x <1, for example 0.10 x <1, for example 0.20 x <1, for example 0.30 x < 1, for example, 0.40? X <1, for example, 0.50? X <1.

The polymer comprising the combination of the above-mentioned chemical formula 4, the chemical formula 5, or the combination of the chemical formula 4 and the chemical formula 5 can be prepared by polymerizing the tetracarboxylic acid dianhydride represented by the chemical formula 1 and the diamine of the chemical formula 2 and chemical formula 3 have.

As mentioned above, the diamine represented by the general formula (3) may be used in an amount of at least about 5 mol%, such as at least about 7 mol%, such as at least about 10 mol%, such as at least about 20 mol% For example, about 30 mol% or more, for example about 40 mol% or more, for example, about 50 mol% or more, and the tetracarboxylic dianhydride represented by the formula (1) at a molar ratio of about 1: 1 , The retardation Rth in the thickness direction of the film produced therefrom can be controlled according to the content of the diamine represented by the above formula (3). That is, by making the molar fraction of the repeating unit of the moiety represented by x equal to or greater than 0.05 in the polymer containing the combination of the above-mentioned formula 4, formula 5, or formula 4 and formula 5, Value. &Lt; / RTI &gt;

Methods for preparing polyamic acids or polyimides by polymerizing diamines and dianhydrides are well known in the art. For example, the diamine represented by the formula 2 or 3 and the monomers of the dianhydride represented by the formula 1 are mixed and polymerized to form the polyamic acid polymer represented by the formula 4, A polyimide polymer, or a poly (amic acid-imide) copolymer represented by the combination of the chemical formulas (4) and (5). Alternatively, polyimide represented by Formula 5 may be prepared by thermally or chemically imidizing the polyamic acid represented by Formula 4 above. The polyamic acid represented by Formula 4 is partially imidized to prepare a poly (amic acid-imide) polymer containing the repeating units of Formula 4 and Formula 5, , The polymer represented by the above formula (5) may be prepared. Thus, the method for producing the polymer is well known in the art, so that detailed description thereof will be omitted.

The retardation in the thickness direction (Rth) can be considerably reduced, and therefore, it can be used as a compensation film. Further, when the film is used as a transparent substrate such as a display device, the substrate also serves as a compensation film, so that no compensation film is required in the display device.

Thus, in another embodiment, there is provided an optical film produced from the composition or the polymer.

The polyimide or polyimide or poly (amic acid-imide) polymer according to the embodiment can be obtained by mixing and reacting the composition according to the above embodiment. The polymer is coated on a substrate or the like to be cast and then subjected to final curing and stretching To obtain a polyimide film. Since the method of producing the film is also well known in the art, a detailed description thereof will be omitted.

As can be seen from the examples described later, when the diamine of formula (3), for example, BAPF, is contained in an amount of about 5 mol% of the total diamine, the retardation Rth in the thickness direction of the film measured at a film thickness of about 10 [ About 700 nm, and when the content of BAPF is about 10 mol%, the retardation Rth in the thickness direction of the film measured at about 10 탆 film thickness is about 500 nm, and when the content is increased to 30 mol%, Rth is about 340 nm. When the content was increased to 50 mol%, Rth decreased to about 200 nm. These results show that Rth is reduced enough to be used as a compensation film when the content of BAPF is in the above range.

Therefore, in one embodiment, the optical film may have a thickness direction retardation (Rth) of 500 nm or less based on a film thickness of about 0.1 mu m to about 200 mu m.

In another embodiment, the optical film may have a thickness direction retardation (Rth) of 400 nm or less based on a film thickness of about 0.1 mu m to about 200 mu m.

In another embodiment, the optical film may have a thickness direction retardation (Rth) of 300 nm or less based on a film thickness of about 0.1 mu m to about 200 mu m.

In another embodiment, the optical film may have a thickness direction retardation (Rth) of 200 nm or less based on a film thickness of about 0.1 mu m to about 200 mu m.

In addition, the film exhibits an average transmittance of about 80% or more, for example, about 85% or more, in the entire wavelength range of 380 nm to 800 nm when measured with a UV spectrometer on the basis of a film thickness of about 0.1 탆 to about 200 탆. And thus has transparency sufficient for use as an optical film.

As a result of measurement of the 0.5% weight reduction temperature of the film, the film exhibits a high temperature of about 400 캜 or higher, for example, about 410 캜 or higher, for example about 420 캜 or higher, for example, about 430 캜 or higher. The stability is also excellent.

In addition, the optical film may have a Yellowness value of about 20 or less based on a film thickness of about 0.1 mu m to about 200 mu m.

Thus, it can be seen that the film is suitable for use as an optical film by having high thermal stability, colorless transparency, and low optical anisotropy (reduced thickness direction retardation).

In another embodiment, an optical device comprising the optical film is provided.

The optical device can be, but is not limited to, a liquid crystal display (LCD) device, an organic light emitting diode (OLED) device, or a complementary metal oxide semiconductor (CMOS) sensor.

As described above, when the optical film is applied to, for example, a liquid crystal display, a great effect can be obtained in decreasing the thickness direction retardation Rth due to the liquid crystal thickness. However, in addition to liquid crystal displays, the optical film can be applied to various substrates in various optical devices.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

( Example )

Example  1 to 4: Polyamic acid  Preparation of polymer

0.0226 mole (6.6463 g) of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (3,6' Bis (trifluoromethyl) benzidine (TFDB) and 4,4'-bis (trifluoromethyl) benzidine were added to a dianhydride mixture containing 0.0056 mol (1.2318 g) A diamine mixture containing bis (aminophenyl) fluorine (BAPF) is mixed and polymerized to prepare a polyimide polymer. In this case, the content of the BAPF was 0 mol% ( Comparative Example 1) , 5 mol% ( Example 1) , 10 mol% ( Example 2) , 30 mol% ( Example 3) Mol% ( Example 4) , respectively, to prepare a diamine mixture. 1 mol of the dianhydride mixture and 1 mol of the diamine mixture are reacted to prepare a polyamic acid polymer.

Specifically, 80 mL of NMP as a solvent was added to a 250 L reactor purged with N ₂ gas, the diamine mixture (TFDB and BAPF) was added at room temperature (25 ° C.), and the mixture was stirred at 100 rpm for about 30 minutes Lt; / RTI &gt; Then, the dianhydride mixture (BPDA and PMDA) is added at once and stirred at room temperature to produce a polyamic acid polymer (takes about 1-2 days). The prepared polyamic acid polymer is stored in the refrigerator.

Manufacturing example : Preparation of polyimide film

For comparison, 1 and the polymers prepared in Examples 1 to 4 are spin-coated to form a film. Thereafter, each film is first dried by heating on a hot plate set at 80 DEG C for 30 minutes. Thereafter, the film is heated in a furnace at a temperature raising rate of 10 DEG C / min from room temperature to about 300 DEG C to obtain a film.

Further, in order to evaluate the final properties, the film is heated from room temperature to 300 DEG C at a heating rate of 10 DEG C / minute, and then subjected to isothermal treatment at 300 DEG C for 60 minutes to produce a necessary film.

Test Example : Property Evaluation of Film

The thickness direction retardation (Rth), the transmittance, the yellowing degree (YI) and the 0.5% weight reduction temperature of each film prepared in the above Production Example were measured, and the results are shown in the following Table 1 Respectively. The transmittance, Rth, weight reduction temperature, and the like are shown in the graphs of FIGS. 1 to 3.

BAPF
(mol%) Film thickness (탆) Rth @ 10 mu m (nm) Permeability (%) YI 0.5%
Weight reduction
Temperature (℃) Overall average @ 400 nm @ 430nm Comparative Example 1 0 15 1200 86.6 37.7 77.4 7.2 452.2 Example 1 5 11 700 87.5 43.4 78.5 6.2 487.6 Example 2 10 12 500 87.3 34.8 74.6 8.2 393.9 Example 3 30 12 340 86.5 21.5 65.7 13 435.2 Example 4 50 11 200 85.7 15.2 59.1 16.7 416.3

As can be seen from the above Table 1, in Examples 1 to 4, which contain at least 5 mol% of 4, 4'-bis (aminophenyl) fluorine (BAPF) The Rth of the polyimide film produced from Example 4 is remarkably reduced to 700 nm or less. In particular, as can be seen from FIG. 1, Rth tends to decrease as the content of BAPF increases.

Furthermore, it can be seen from Table 1 and Fig. 2 that the average transmittance in the entire wavelength range of the film produced according to Examples 1 to 4 is not less than 85%, and is made of a transparent film. However, the transmittance at 400 nm and 450 nm tends to decrease as the content of BAPF increases.

In the case of yellowing degree (YI), it can be seen from Table 1 that the YI value is further reduced as compared with Comparative Example 1 which does not include BAPF in the case of Example 1 including 5 mol% of BAPF as the total diamine content have. However, in Examples 2 to 4 in which BAPF contains 10 mol% or more of the total diamine content, YI tends to increase slightly as the BAPF content increases. However, even in the above content range, YI shows a low value of 20 or less.

In the case of the weight reduction temperature of 0.5%, the change according to the amount of BAPF added is not large, and all the films exhibit a high temperature of about 400 ° C or more, indicating that the films produced according to these examples have excellent high temperature stability.

Thus, it can be seen that the film produced according to the above example is excellent in transparency and high-temperature stability and has a low retardation value in the thickness direction, that is, low optical anisotropy, so that it is suitable for use as an optical film such as a compensation film .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be appreciated that modifications and variations of the disclosed invention and implementations thereof which may be made therein easily are all within the scope of the invention.

Claims (20)

A tetracarboxylic acid dianhydride represented by the following formula (1), a diamine represented by the following formula (2), and a diamine represented by the following formula (3), wherein the diamine represented by the following formula A composition for producing an optical film:
(Formula 1)

(2)
NH ₂ -R ₂ -NH ₂
(Formula 3)

In the above formulas (1) and (2)
R ₁ and R ₂ each independently represent a substituted or unsubstituted C 4 to C 20 aliphatic cyclic group, or a substituted or unsubstituted C 6 to C 30 aromatic organic group, the aromatic organic group being present alone; Two or more are bonded to each other to form a condensed ring; Or two or more aromatic rings may be substituted by a single bond or a fluorenylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C15 arylene group, -O-, -S-, -C = O) -, -CH (OH ) -, -S (= O) 2 -, -Si (CH 3) 2 -, - (CH 2) p - ( where, 1≤p≤10), - (CF ₂ ) _q -, where ₁ ? _Q ? 10, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, or -C (= O)
In Formula 3, R ₃ to R ₆ are each independently a C1 to C20 alkyl group, a C6 to C20 aryl group, or a halogen group (F, Cl, Br, I)
N1 to n4 are each an integer of 0 to 4; 2. The composition of claim 1, wherein the diamine of Formula 3 is present in an amount of at least about 10 mole percent of the total diamine. The composition of claim 1, wherein the diamine of Formula 3 is included in an amount of about 20 mole% or more of the total diamines. The tetracarboxylic dianhydride of claim 1, wherein the tetracarboxylic acid dianhydride is 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride (3,3', 4,4'-biphenyl tetracarboxylic dianhydride, BPDA), bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (bicycle [2.2.2] oct-7-ene-2,3,5,6 tetracarboxylic dianhydride (BTDA), 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA), 4,4'-diphenylsulfone tetracarboxylic dianhydride (Hexafluoroisopropylidene) diphthalic anhydride (6FDA), 4,4'-oxydiphthalic anhydride (ODPA), 4,4'-oxydiphthalic anhydride Pyromellitic dianhydride (PMDA), and 4 - ((2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetranaphthalene-1,2 (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride. dicarboxylic anhydride, DTDA). The composition according to claim 1, wherein the diamine of the formula (2) is at least one compound selected from the group consisting of compounds represented by the following formulas:

In the above formulas,
R ³² to R ⁵² are the same or different from each other and each independently represents a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted C1 to C15 alkyl group, a substituted or unsubstituted C1 to C15 alkoxy group, a substituted or unsubstituted C1 A substituted or unsubstituted C3 to C15 cycloalkyl group, a substituted or unsubstituted C3 to C15 heterocycloalkyl group, a substituted or unsubstituted C3 to C15 oxycycloalkyl group, a substituted or unsubstituted C6 to C15 aryl A substituted or unsubstituted C6 to C15 oxyaryl group, or a substituted or unsubstituted C2 to C15 heteroaryl group,
X ² to X ¹² are the same or different from each other and each independently represents a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C15 An arylene group, -SO ₂ -, -O-, -CO-, or a combination thereof,
n35 to n37, and n40 to n49 are any of integers of 0 to 4,
n38 and n39 are each an integer of 0 to 3; The composition according to claim 1, wherein the diamine of the formula (2) is at least one compound selected from the group consisting of compounds represented by the following formulas:

The composition according to claim 1, wherein n1 to n4 in Formula 3 are all 0. A polymer comprising a combination of the following formula (4), (5), or (4) and (5)
(Formula 4)

(Formula 5)

In the above formulas (4) and (5)
R ₁ and R ₂ each independently represent a substituted or unsubstituted C 4 to C 20 aliphatic cyclic group, or a substituted or unsubstituted C 6 to C 30 aromatic organic group, the aromatic organic group being present alone; Two or more are bonded to each other to form a condensed ring; Or two or more aromatic rings may be substituted by a single bond or a fluorenylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C15 arylene group, -O-, -S-, -C = O) -, -CH (OH ) -, -S (= O) 2 -, -Si (CH 3) 2 -, - (CH 2) p - ( where, 1≤p≤10), - (CF ₂ ) _q -, where ₁ ? _Q ? 10, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, or -C (= O)
R ₃ to R ₆ are each independently a C1 to C20 alkyl group, a C6 to C20 aryl group, or a halogen group (F, Cl, Br, I)
n1 to n4 are each an integer of 0 to 4,
x and y are mole fractions of respective repeating units in the polymer, and 0.05? x <1 and y = 1-x. 9. The polymer of claim 8, wherein R ₁ and R ₂ are each a group represented by the following formula:

9. The polymer according to claim 8, wherein n1 to n4 are both 0. An optical film produced from the composition of claim 1 or the polymer of claim 8. 12. The optical film according to claim 11, wherein the thickness direction retardation (Rth) is about 500 nm or less based on the film thickness of 0.1 mu m to 200 mu m. 12. The optical film according to claim 11, wherein the thickness direction retardation (Rth) is about 400 nm or less based on the film thickness of 0.1 mu m to 200 mu m. 12. The optical film according to claim 11, wherein the thickness direction retardation (Rth) is about 300 nm or less based on the film thickness of 0.1 mu m to 200 mu m. 12. The optical film according to claim 11, wherein the thickness direction retardation (Rth) is about 200 nm or less based on the film thickness of 0.1 mu m to 200 mu m. The optical film according to claim 11, wherein the average transmittance at 380 nm to 800 nm is about 80% or more when measured with a UV spectrometer based on a film thickness of 0.1 mu m to 200 mu m. 12. The optical film according to claim 11, wherein the 0.5% weight reduction temperature is 400 DEG C or higher. 12. The optical film according to claim 11, wherein the Yellowness is about 20 or less based on the film thickness of 0.1 mu m to 200 mu m. An optical device comprising the optical film of claim 11. 20. The optical device of claim 19, wherein the device is a liquid crystal display (LCD) device, an organic light emitting diode (OLED) device, or a complementary metal oxide semiconductor (CMOS) sensor.

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