KR20210015314A - Polyamideimide copolymers and optical film comprising the same - Google Patents

Abstract

The present invention relates to a polyamideimide copolymer and an optical film comprising the same. The polyamideimide copolymer according to the present invention can have a high molecular weight and makes it possible to provide the optical film having excellent mechanical properties. The present invention relates to an imide compound of polyamic acid having a first repeating unit derived from copolymerization of a first aromatic diamine compound and an aromatic dianhydride compound, and a second repeating unit derived from copolymerization of a second aromatic diamine compound and an aromatic dicarbonyl dichloride compound.

Description

A polyamideimide copolymer and an optical film containing the same TECHNICAL FIELD [0001] POLYAMIDEIMIDE COPOLYMERS AND OPTICAL FILM COMPRISING THE SAME}

The present invention relates to a polyamideimide copolymer and an optical film comprising the same.

Aromatic polyimide resins are mostly polymers having an amorphous structure and exhibit excellent heat resistance, chemical resistance, electrical properties, and dimensional stability due to a rigid chain structure. These polyimide resins are widely used as electrical/electronic materials.

However, polyimide resins are limited in use because they have a dark brown color due to the formation of a charge transfer complex (CTC) of π electrons present in the imide chain.

In order to overcome the above limitation and obtain a colorless transparent polyimide resin, a method of restricting the movement of π electrons by introducing a strong electron attracting group such as trifluoromethyl (-CF ₃ ) group; A method of reducing the formation of the CTC by introducing a sulfone (-SO ₂ -) group, an ether (-O-) group, etc. to the main chain to form a curved structure; Alternatively, a method of inhibiting the formation of a resonance structure of π-electrons by introducing an alicyclic compound has been proposed.

However, it is difficult for the polyimide resin according to the above proposals to exhibit sufficient heat resistance due to a bent structure or an alicyclic compound, and a film manufactured using the polyimide resin has a limitation in exhibiting poor mechanical properties.

Recently, in order to improve the scratch resistance of the polyimide, a polyamideimide copolymer in which a polyamide unit structure is introduced has been proposed.

However, the polyamideimide copolymer exhibits a tendency to haze easily when a film is formed by coating it due to its high crystallinity, and there is still a limitation in that it does not exhibit sufficient mechanical properties.

The present invention is to provide a polyamide-imide copolymer excellent in mechanical properties.

In addition, the present invention is to provide an optical film comprising the polyamideimide copolymer.

According to the present invention,

An image of a polyamic acid having a first repeating unit derived from copolymerization of a first aromatic diamine compound and an aromatic dianhydride compound, and a second repeating unit derived from copolymerization of a second aromatic diamine compound and an aromatic dicarbonyl dichloride compound. As dehydrate;

The dicarbonyl dichloride compound is copolymerized in a molar ratio of more than 1.01 mol to 1 mol of the second aromatic diamine compound;

The dicarbonyl dichloride compound is 65 mol% or more of 4,4'-biphenyldicarbonyl chloride and 35 mol% or less of isophthaloyl chloride or terephthaloyl. Consisting of terephthaloyl chloride,

Polyamideimide copolymers are provided.

Further, according to the present invention, an optical film comprising the polyamideimide copolymer is provided.

Hereinafter, a polyamideimide copolymer according to embodiments of the present invention and an optical film including the same will be described in detail.

Unless expressly stated in the specification, terminology is only intended to refer to specific embodiments and is not intended to limit the invention.

The singular forms used in the present specification also include plural forms unless the phrases clearly indicate the opposite.

As used herein, the meaning of "comprising" specifies a specific characteristic, region, integer, step, action, element and/or component, and other specific characteristic, region, integer, step, action, element, component and/or group It does not exclude the existence or addition of

In the present specification, terms including ordinal numbers such as "first" and "second" are used for the purpose of distinguishing one component from other components, and are not limited by the ordinal number. For example, within the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

I. Polyamideimide Copolymer

According to one embodiment of the invention,

An image of a polyamic acid having a first repeating unit derived from copolymerization of a first aromatic diamine compound and an aromatic dianhydride compound, and a second repeating unit derived from copolymerization of a second aromatic diamine compound and an aromatic dicarbonyl dichloride compound. As dehydrate;

The dicarbonyl dichloride compound is copolymerized in a molar ratio of more than 1.01 mol to 1 mol of the second aromatic diamine compound;

The dicarbonyl dichloride compound is 65 mol% or more of 4,4'-biphenyldicarbonyl chloride and 35 mol% or less of isophthaloyl chloride or terephthaloyl. Consisting of terephthaloyl chloride,

Polyamideimide copolymers are provided.

As a result of continuous research by the present inventors, the polyamideimide copolymer having a second repeating unit that simultaneously satisfies the conditions of the molar ratio and the molar fraction can have a high molecular weight and provide an optical film having excellent mechanical properties. Was confirmed.

When an amine group derived from the second aromatic diamine compound is present at the end of the second repeating unit, a polymer having a low molecular weight is obtained due to the nature of condensation polymerization, and productivity decreases due to poor mechanical properties in film processes such as solution casting. Can be.

However, since the polyamide-imide copolymer according to the present invention includes the second repeating unit that satisfies the molar ratio condition, the amine group may be prevented from remaining at the end of the second repeating unit.

Furthermore, the polyamide-imide copolymer according to the present invention may exhibit a high molecular weight by including the second repeating unit that simultaneously meets the conditions of the molar ratio and the molar fraction, and improved mechanical properties such as elastic modulus and hardness. It is possible to provide an optical film having.

According to an embodiment of the present invention, the polyamideimide copolymer comprises a first repeating unit derived from copolymerization of a first aromatic diamine compound and an aromatic dianhydride compound, and a second aromatic diamine compound and an aromatic dicarbonyl dichloride compound. It is an imidized product of a polyamic acid having a second repeating unit derived from copolymerization.

The polyamic acid forms a polyamideimide copolymer having both an imide bond and an amide bond by imidation.

The first and second aromatic diamine compounds may be compounds known to be applicable to the formation of polyamide-imide copolymers in the art.

The first and second aromatic diamine compounds may be the same compound.

The first and second aromatic diamine compounds may be different compounds.

As the first and second aromatic diamine compounds, at least one compound may be applied, respectively.

When two or more types of compounds are applied as the first and second aromatic diamine compounds, the first and second aromatic diamine compounds may have the same or different combinations, and may include at least one type of the same compound.

For example, the first and second aromatic diamine compounds are each independently 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (2,2'-bis(trifluoromethyl)-4 ,4'-biphenyldiamine), 4,4'-diaminodiphenyl sulfone (4,4'-diaminodiphenyl sulfone), 4,4'-(9-fluorenylidene) dianiline (4,4'-(9 -fluorenylidene)dianiline), bis(4-(4-aminophenoxy)phenyl) sulfone (bis(4-(4-aminophenoxy)phenyl)sulfone), 2,2',5,5'-tetrachlorobenzidine (2 ,2',5,5'-tetrachlorobenzidine), 2,7-diaminofluorene (2,7-diaminofluorene), 4,4-diaminooctafluorobiphenyl (4,4-diaminooctafluorobiphenyl), m-phenylene Diamine (m-phenylenediamine), p-phenylenediamine (p-phenylenediamine), 4,4'-oxydianiline (4,4'-oxydianiline), 2,2'-dimethyl-4,4'-diamino ratio Phenyl (2,2'-dimethyl-4,4'-diaminobiphenyl), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (2,2-bis[4-(4-aminophenoxy)phenyl) ]propane), 1,3-bis (4-aminophenoxy) benzene (1,3-bis (4-aminophenoxy) benzene), and 4,4'-diaminobenzanilide (4,4'-diaminobenzanilide) It may be one or more compounds selected from the group consisting of.

Each of the first and second aromatic diamine compounds is 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine) Can be

The aromatic dianhydride compound may be a compound known to be applicable to the formation of a polyamide-imide copolymer in the technical field to which the present invention belongs.

One or more types of compounds may be applied as the aromatic dianhydride compound.

For example, the aromatic dianhydride compound is 3,3',4,4'-biphenyltetracarboxylic dianhydride (3,3',4,4'-biphenyltetracarboxylic dianhydride), 4,4'- (Hexafluoroisopropylidene) diphthalic anhydride (4,4'-(hexafluoroisopropylidene) diphthalic anhydride), 2,2'-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride ( 2,2'-bis-(3,4-dicarboxyphenyl)hexafluoropropane dianhydride), benzophenone tetracarboxylic dianhydride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride Dianehydride (benzophenone tetracarboxylic dianhydride), oxydiphthalic anhydride (oxydiphthalic anhydride), cyclobutane-1,2,3,4-tetracarboxylic dianhydride (cyclobutane-1,2,3,4-tetracarboxylic dianhydride), cyclopentane tetracarboxylic dianhydride, and bis (3,4-dicarboxyphenyl) sulfone dianhydride (bis (3,4-dicarboxyphenyl) sulfone dianhydride) selected from the group consisting of It may be one or more compounds.

The aromatic dianhydride compound is 3,3',4,4'-biphenyltetracarboxylic dianhydride (3,3',4,4'-biphenyltetracarboxylic dianhydride), 4,4'- (hexafluoro Isopropylidene) diphthalic anhydride (4,4'-(hexafluoroisopropylidene) diphthalic anhydride), or a mixture thereof.

According to an embodiment of the present invention, the dicarbonyl dichloride compound is copolymerized in a molar ratio of more than 1.01 mol to 1 mol of the second aromatic diamine compound, and is included in the second repeating unit.

In order to prevent the amine group derived from the second aromatic diamine compound from remaining at the end of the second repeating unit, the dicarbonyl dichloride compound is greater than 1.01 moles compared to 1 mole of the second aromatic diamine compound. It is preferable to be copolymerized in a ratio.

However, when the dicarbonyl dichloride compound is applied at a molar ratio that is too large compared to the second aromatic diamine compound, the reaction efficiency is lowered to form a polymer having a low molecular weight, thereby deteriorating the mechanical properties of the optical film. . Therefore, the dicarbonyl dichloride compound is preferably copolymerized at a molar ratio of 1.09 mol or less to 1 mol of the second aromatic diamine compound.

Specifically, the dicarbonyl dichloride compound is 1.01 mol or more, or 1.02 mol or more, or 1.03 mol or more compared to 1 mol of the second aromatic diamine compound; And it is copolymerized at a molar ratio of 1.09 mol or less, 1.08 mol or less, or 1.07 mol or less, or 1.06 mol or less, or 1.055 mol or less.

More preferably, the dicarbonyl dichloride compound is more than 1.01 mol to 1.09 mol or less, or 1.02 mol to 1.09 mol, or 1.03 mol to 1.09 mol, or 1.03 mol to 1.08 mol, relative to 1 mol of the second aromatic diamine compound , Or 1.03 mol to 1.07 mol, 1.03 mol to 1.06 mol, or 1.03 mol to 1.055 mol.

According to an embodiment of the present invention, the aromatic dicarbonyl dichloride compound essentially includes 4,4'-biphenyldicarbonyl chloride (CAS Registry No. 2351-37-3). do. And, the aromatic dicarbonyl dichloride compound is isophthaloyl chloride (CAS Registry No. 99-63-8), terephthaloyl chloride (terephthaloyl chloride; CAS Registry No. 100-20-9), Or it may further include a mixture thereof.

Preferably, the dicarbonyl dichloride compound is 65 mol% or more of 4,4'-biphenyldicarbonyl chloride (4,4'-biphenyldicarbonyl chloride) and 35 mol% or less isophthaloyl chloride (isophthaloyl chloride). ) Or terephthaloyl chloride.

In order to express improved mechanical properties such as elastic modulus and hardness from the polyamideimide copolymer, 4,4'-biphenyldicarbonyl chloride is used as the aromatic dicarbonyl dicarbonyl. It is preferred to apply at least 65 mol% relative to the total number of moles of the chloride compound.

However, when an excessive amount of 4,4'-biphenyldicarbonyl chloride is applied, the yellowness and haze of the optical film may increase. Therefore, 4,4'-biphenyldicarbonyl chloride is preferably applied in an amount of 85 mol% or less with respect to the total number of moles of the aromatic dicarbonyl dichloride compound.

Specifically, 4,4'-biphenyldicarbonyl chloride is 65 mol% or more, or 70 mol% or more with respect to the total number of moles of the aromatic dicarbonyl dichloride compound; And 85 mol% or less, or 80 mol% or less may be applied.

And, isophthaloyl chloride (isophthaloyl chloride) or terephthaloyl chloride (terephthaloyl chloride) is 35 mol% or less, or 30 mol% or less with respect to the total number of moles of the aromatic dicarbonyl dichloride compound; And 15 mol% or more, or 20 mol% or more may be applied.

Preferably, 4,4'-biphenyldicarbonyl chloride is 65 to 85 mol%, or 70 to 85 mol%, or 70 to 80 mol% based on the total number of moles of the aromatic dicarbonyl dichloride compound. Can be applied.

And, isophthaloyl chloride (isophthaloyl chloride) or terephthaloyl chloride (terephthaloyl chloride) is 15 to 35 mol%, or 20 to 35 mol%, or 20 with respect to the total number of moles of the aromatic dicarbonyl dichloride compound. It can be applied in to 30 mol%.

It is preferable that the molar ratio of the first repeating unit and the second repeating unit is 1:2 to 1:3. The molar ratio may mean a ratio of the total number of moles of the compound applied to the formation of the first repeating unit and the total number of moles of the compound applied to the formation of the second repeating unit.

By satisfying the molar ratio of the second repeating unit and the molar fraction condition of the first repeating unit and the second repeating unit, a polyamideimide copolymer having more excellent mechanical properties can be provided. I can.

Preferably, the molar ratio of the first repeating unit and the second repeating unit is 1: 2.0 to 1: 3.0, or 1: 2.1 to 1: 2.8, or 1: 2.2 to 1: 2.5, or 1:2.3 to 1: can be 2.5.

Meanwhile, the polyamideimide copolymer having the first and second repeating units may be obtained under a conventional manufacturing method and polymerization conditions for forming a block copolymer.

For example, the polyamideimide copolymer may include: (i) condensation polymerization of the first aromatic diamine compound and the aromatic dianhydride compound to form a first repeating unit; (ii) adding the second aromatic diamine compound and the aromatic dicarbonyl dichloride compound and performing condensation polymerization to form a polyamic acid having first and second repeating units; And (iii) imidizing the polyamic acid to form a polyamideimide copolymer.

Preferably, the polymerization for the formation of the polyamic acid may be performed by solution polymerization under an inert atmosphere of 0 to 100°C.

As a solvent for the formation of the polyamic acid, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, acetone, N-methyl-2-pyrrolidone, tetrahydrofuran, chloroform, gamma- Butyrolactone and the like may be used.

Imidation after formation of the polyamic acid may be performed thermally or chemically. For example, a compound such as acetic anhydride or pyridine may be used for chemical imidation.

According to an embodiment of the present invention, the polyamideimide copolymer may have a number average molecular weight (Mn) of 250,000 g/mol or more and a weight average molecular weight (Mw) of 500,000 g/mol or more.

In order to sufficiently express the effect of improving physical properties according to the present invention, the polyamideimide copolymer preferably has a number average molecular weight (Mn) of 250,000 g/mol or more and a weight average molecular weight (Mw) of 500,000 g/mol or more. Do.

However, if the molecular weight of the copolymer is too large, processability may be poor. Therefore, it is preferable that the polyamideimide copolymer has a number average molecular weight (Mn) of 500,000 g/mol or less and a weight average molecular weight (Mw) of 1,000,000 g/mol or less.

Specifically, the number average molecular weight (Mn) of the polyamideimide copolymer is 250,000 g/mol or more, or 270,000 g/mol or more, or 300,000 g/mol or more, or 310,000 g/mol or more; And it may be 500,000 g/mol or less, or 450,000 g/mol or less, or 430,000 g/mol or less. Preferably, the polyamideimide copolymer is 250,000 to 500,000 g/mol, or 270,000 to 500,000 g/mol, or 270,000 to 450,000 g/mol, or 300,000 to 450,000 g/mol, or 310,000 to 450,000 g/mol, Alternatively, it may have a number average molecular weight (Mn) of 310,000 to 430,000 g/mol.

Further, the weight average molecular weight (Mw) of the polyamideimide copolymer is 500,000 g/mol or more, or 550,000 g/mol or more, or 600,000 g/mol or more, or 650,000 g/mol or more, or 700,000 g/mol or more; And it may be 1,000,000 g/mol or less, or 950,000 g/mol or less, or 940,000 g/mol or less. Preferably, the polyamideimide copolymer is 500,000 to 1,000,000 g/mol, or 550,000 to 1,000,000 g/mol, or 600,000 to 950,000 g/mol, or 650,000 to 950,000 g/mol, or 700,000 to 940,000 g/mol It may have a weight average molecular weight (Mw).

As a non-limiting example, the number average molecular weight (Mn) and weight average molecular weight (Mw) of the polyamideimide copolymer were obtained using an Agilent PL-GPC 220 instrument equipped with a 300 mm long PolarGel MIXED-L column (Polymer Laboratories). Can be measured. The measurement temperature is 65°C, dimethylformamide is used as a solvent, and the flow rate is measured at a rate of 1 mL/min. The sample is prepared to a concentration of 10 mg/10 mL, and then supplied in an amount of 100 μL. The Mw value and Mn value are derived with reference to the calibration curve formed using the polystyrene standard. The molecular weight (g/mol) of the polystyrene standard is 580/ 3,940/ 8,450/ 31,400/ 70,950/ 316,500/ 956,000/ 4,230,000.

II. Optical film

According to another embodiment of the present invention, an optical film including the polyamideimide copolymer is provided.

As described above, the polyamideimide copolymer having the second repeating unit satisfying the conditions of the molar ratio and the molar fraction at the same time can have a high molecular weight and can provide an optical film having excellent mechanical properties.

The optical film including the polyamide-imide copolymer may be used as a material for various molded articles requiring excellent mechanical properties along with colorless transparency. For example, the optical film may be applied to a display substrate, a protective film for a display, a touch panel, or the like.

The optical film may be prepared by a conventional method such as a dry method or a wet method using the polyamideimide copolymer.

For example, the optical film may be obtained by coating a solution containing the polyamide-imide copolymer on an arbitrary support to form a film, and drying by evaporating a solvent from the film. If necessary, stretching and heat treatment may be performed on the optical film.

As the optical film is prepared using the polyamideimide copolymer, it may exhibit excellent mechanical properties.

Specifically, the optical film has an elasticity of 6.00 GPa or more, or 6.00 to 7.50 GPa, or 6.10 to 7.00 GPa, or 6.20 to 6.70 GPa, measured according to the standard test method of ASTM D882 for a film specimen having a thickness of 50 ± 5 μm. It can represent elastic modulus.

The elastic modulus is a value measured using a tensile property tester with reference to the standard test method of ASTM D882. The load cell used was 1.0 kN, and the measurement speed was 12.5 mm/min.

The polyamideimide copolymer according to the present invention can have a high molecular weight and makes it possible to provide an optical film having excellent mechanical properties.

1 is a ¹ H-NMR spectrum of a polyamideimide copolymer obtained in Example 1. FIG.
2 is a ¹ H-NMR spectrum of the polyamideimide copolymer obtained in Comparative Example 1.

Hereinafter, preferred embodiments are presented to aid in understanding the invention. However, the following examples are for illustrative purposes only, and the invention is not limited thereto.

Example 1

A 500 mL three-necked round bottomed flask equipped with a dean-stark trap, a nitrogen inlet and a mechanical stirrer was prepared. In the flask, 3.2344 g (10.100 mmol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine; TFMB ), 1.5888 g (5.400 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (3,3',4,4'-biphenyltetracarboxylic dianhydride; BPDA), 1.9991 g (4.500 mmol) ) Of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (4,4'-(hexafluoroisopropylidene)diphthalic anhydride; 6FDA), and 37.9 g of anhydrous N,N-dimethylacetamide (anhydrous N ,N-dimethylacetamide) was added and completely dissolved, and the polymerization reaction was carried out while stirring at a temperature of 40°C for 4 hours.

Then, for the formation of the second repeating unit, 7.4402 g (23.233 mmol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (2,2'-bis( trifluoromethyl)-4,4'-biphenyldiamine; TFMB), 4.7264 g (16.933 mmol) of 4,4'-biphenyldicarbonyl chloride (BPC), 1.4211 g (7.000 mmol) of Isophthaloyl chloride (IPC), and 68.3 g of anhydrous N,N-dimethylacetamide were added thereto, and the polymerization reaction was carried out while further stirring for 4 hours.

Thereafter, 5.5433 g of pyridine and 7.1545 g of acetic anhydride were added to the flask, and the reaction was carried out for 12 hours.

After completion of the reaction, a solid content was precipitated using an excess of ethanol, filtered, and dried under vacuum at 100° C. for 6 hours or more to obtain a polyamideimide copolymer (Mn 310,000 g/mol; Mw 720,000 g/mol).

¹ H-NMR (300 MHz, DMSO-d6, standard TMS) spectrum of the polyamideimide copolymer is shown in FIG. 1.

Referring to FIG. 1, no characteristic peak is observed in the range of 10.3 to 10.4 ppm of the ¹ H-NMR spectrum.

Comparative Example 1

A 500 mL three-necked round bottomed flask equipped with a dean-stark trap, a nitrogen inlet and a mechanical stirrer was prepared. In the flask, 3.2344 g (10.100 mmol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine; TFMB ), 1.5888 g (5.400 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (3,3',4,4'-biphenyltetracarboxylic dianhydride; BPDA), 1.9991 g (4.500 mmol) ) Of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (4,4'-(hexafluoroisopropylidene)diphthalic anhydride; 6FDA), and 37.9 g of anhydrous N,N-dimethylacetamide (anhydrous N ,N-dimethylacetamide) was added and completely dissolved, and the polymerization reaction was carried out while stirring at a temperature of 40°C for 4 hours.

Then, for the formation of the second repeating unit, 7.4402 g (23.233 mmol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (2,2'-bis( trifluoromethyl)-4,4'-biphenyldiamine; TFMB), 4.5869 g (16.433 mmol) of 4,4'-biphenyldicarbonyl chloride (BPC), 1.4211 g (7.000 mmol) Isophthaloyl chloride (IPC), and 60.1 g of anhydrous N,N-dimethylacetamide were added thereto, and the polymerization reaction was carried out while further stirring for 4 hours.

Thereafter, 5.5433 g of pyridine and 7.1545 g of acetic anhydride were added to the flask, and the reaction was carried out for 12 hours.

After completion of the reaction, a solid content was precipitated with an excess of ethanol, filtered, and dried under vacuum at 100° C. for 6 hours or more to obtain a polyamideimide copolymer (Mn 250,000 g/mol; Mw 410,000 g/mol).

¹ H-NMR (300 MHz, DMSO-d6, standard TMS) spectrum of the polyamideimide copolymer is shown in FIG. 2.

Referring to FIG. 2, characteristic peaks are observed in the range of 10.3 to 10.4 ppm in the ¹ H-NMR spectrum. It is confirmed that the characteristic peak is due to an amine group present at the end of the polyamideimide copolymer.

Example 2

The compound for the formation of the second repeating unit was 7.4402 g (23.233 mmol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB), 4.8660 g (17.433 mmol) of 4 ,4'-biphenyldicarbonyl chloride (BPC), 1.4211 g (7.000 mmol) of isophthaloyl chloride (IPC), except that the polyamideimide copolymer in the same manner as in Example 1 ( Mn 430,000 g/mol; Mw 940,000 g/mol) was obtained.

Example 3

The compound for the formation of the second repeating unit was 7.4402 g (23.233 mmol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB), 4.4008 g (15.767 mmol) of 4 ,4'-biphenyldicarbonyl chloride (BPC), 1.6580 g (8.167 mmol) of isophthaloyl chloride (IPC), except that the polyamideimide copolymer in the same manner as in Example 1 ( Mn 320,000 g/mol; Mw 700,000 g/mol) was obtained.

Comparative Example 2

The compound for the formation of the second repeating unit was 7.4402 g (23.233 mmol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB), 3.9356 g (14.100 mmol) of 4 ,4'-biphenyldicarbonyl chloride (BPC), 1.8949 g (9.333 mmol) of isophthaloyl chloride (IPC), except that the polyamideimide copolymer in the same manner as in Example 1 ( Mn 230,000 g/mol; Mw 400,000 g/mol) was obtained.

Reference example

The compound for the formation of the second repeating unit was 7.4402 g (23.233 mmol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB), 5.1451 g (18.433 mmol) of 4 ,4'-biphenyldicarbonyl chloride (BPC), 1.4211 g (7.000 mmol) of isophthaloyl chloride (IPC), except that the polyamideimide copolymer in the same manner as in Example 1 ( Mn 64,000 g/mol; Mw 108,000 g/mol) was obtained.

Molar rain BPC
(mol%) IPC
(mol%) Mn
(g/mol) Mw
(g/mol) Example 1 1: 1.030 70.8 29.2 310,000 720,000 Example 2 1: 1.052 71.4 28.6 430,000 940,000 Example 3 1: 1.030 65.9 34.1 320,000 700,000 Comparative Example 1 1: 1.009 70.1 29.9 250,000 410,000 Comparative Example 2 1: 1.009 60.2 39.8 230,000 400,000 Comparative Example 3 1: 1.095 72.5 27.5 64,000 108,000

*The "molar ratio" is the molar ratio value of the dicarbonyl dichloride compound (sum of the number of moles of BPC and IPC) to 1 mole of the aromatic diamine compound (TFMB) used to form the second repeating unit.

*The "mol%" value of the BPC and IPC is the molar fraction value of BPC and IPC converted based on the total number of moles of the dicarbonyl dichloride compound.

Manufacturing Example 1

The polyamideimide copolymer obtained in Example 1 was dissolved in anhydrous N,N-dimethylacetamide to prepare a 20% (w/V) casting solution. The casting solution was bar-coated on a glass substrate to a thickness of 300 µm, and dried at 200°C. An optical film having a thickness of 50 ± 5 μm peeled off from the glass substrate was obtained.

Manufacturing Example 2

An optical film having a thickness of 50 ± 5 µm was obtained in the same manner as in Preparation Example 1, except that the polyamide-imide copolymer obtained in Example 2 was used instead of the polyamide-imide copolymer obtained in Example 1.

Manufacturing Example 3

An optical film having a thickness of 50 ± 5 μm was obtained in the same manner as in Preparation Example 1, except that the polyamide-imide copolymer obtained in Example 3 was used instead of the polyamide-imide copolymer obtained in Example 1.

Manufacturing Example 4

An optical film having a thickness of 50 ± 5 µm was obtained in the same manner as in Preparation Example 1, except that the polyamide-imide copolymer obtained in Comparative Example 1 was used instead of the polyamide-imide copolymer obtained in Example 1.

Manufacturing Example 5

An optical film having a thickness of 50 ± 5 μm was obtained in the same manner as in Preparation Example 1, except that the polyamide-imide copolymer obtained in Comparative Example 2 was used instead of the polyamide-imide copolymer obtained in Example 1 above.

Manufacturing Example 6

An optical film having a thickness of 50 ± 5 µm was obtained in the same manner as in Preparation Example 1, except that the polyamide-imide copolymer obtained in Reference Example was used instead of the polyamide-imide copolymer obtained in Example 1.

Test example

The following physical properties were measured for the polyamideimide copolymer obtained in Examples, Comparative Examples, and Reference Examples and the film obtained in Preparation Example, and the results are shown in Tables 1 and 2 below.

(1) Molecular weight of the copolymer

: Using an Agilent PL-GPC 220 instrument equipped with a 300 mm PolarGel MIXED-L column (Polymer Laboratories), the number average molecular weight (Mn, g/mol) of the polyamideimide copolymer obtained in the Examples and Comparative Examples The weight average molecular weight (Mw, g/mol) was measured.

The measurement temperature was 65 °C, dimethylformamide was used as a solvent, and the flow rate was measured at a rate of 1 mL/min. The sample is prepared to a concentration of 10 mg/10 mL, and then supplied in an amount of 100 μL. The values of Mw and Mn are derived with reference to the calibration curve formed using polystyrene standards. The molecular weight (g/mol) of the polystyrene standard is 580/ 3,940/ 8,450/ 31,400/ 70,950/ 316,500/ 956,000/ 4,230,000.

(2) Mechanical properties

: Using the Universal testing machine Z005 (Zwick/Roell Materials Testing Systems), the elastic modulus (GPa) of a film specimen having a thickness of 50 ± 5 µm was measured according to the standard test method of ASTM D882. The load cell used was 1.0 kN, and the measurement speed was 12.5 mm/min.

film Copolymer Mn
(g/mol) Mw
(g/mol) Elastic modulus
(GPa) Manufacturing Example 1 Example 1 310,000 720,000 6.33 Manufacturing Example 2 Example 2 430,000 940,000 6.72 Manufacturing Example 3 Example 3 320,000 700,000 6.05 Manufacturing Example 4 Comparative Example 1 250,000 410,000 5.74 Manufacturing Example 5 Comparative Example 2 230,000 400,000 5.49 Manufacturing Example 6 Reference example 64,000 108,000 3.78

Referring to Tables 1 and 2, it is confirmed that the films of Preparation Examples 1 to 3 can exhibit high elastic modulus as the copolymers of Examples 1 to 3 having a high molecular weight are applied.

In contrast, it was confirmed that the films of Preparation Examples 4 to 6 exhibit poor elastic modulus as a copolymer that does not meet the desirable properties according to the present invention is applied.

Claims (9)

An image of a polyamic acid having a first repeating unit derived from copolymerization of a first aromatic diamine compound and an aromatic dianhydride compound, and a second repeating unit derived from copolymerization of a second aromatic diamine compound and an aromatic dicarbonyl dichloride compound. As dehydrate;
The dicarbonyl dichloride compound is copolymerized in a molar ratio of more than 1.01 mol to 1 mol of the second aromatic diamine compound;
The dicarbonyl dichloride compound is 65 mol% or more of 4,4'-biphenyldicarbonyl chloride and 35 mol% or less of isophthaloyl chloride or terephthaloyl. Consisting of terephthaloyl chloride,
Polyamideimide copolymer.
The method of claim 1,
The dicarbonyl dichloride compound is copolymerized in a molar ratio of more than 1.01 and not more than 1.09 with respect to 1 mol of the second aromatic diamine compound, a polyamideimide copolymer.
The method of claim 1,
The dicarbonyl dichloride compound is 65 to 85 mol% of 4,4'-biphenyldicarbonyl chloride and 15 to 35 mol% of isophthaloyl chloride Or terephthaloyl chloride (terephthaloyl chloride) consisting of, polyamide-imide copolymer.
The method of claim 1,
The molar ratio of the first repeating unit and the second repeating unit is 1:2 to 1:3, a polyamide-imide copolymer.
The method of claim 1,
The first and second aromatic diamine compounds are each independently 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (2,2'-bis(trifluoromethyl)-4,4'- biphenyldiamine), 4,4'-diaminodiphenyl sulfone, 4,4'-(9-fluorenylidene)dianiline (4,4'-(9-fluorenylidene)dianiline ), bis(4-(4-aminophenoxy)phenyl) sulfone (bis(4-(4-aminophenoxy)phenyl)sulfone), 2,2',5,5'-tetrachlorobenzidine (2,2', 5,5'-tetrachlorobenzidine), 2,7-diaminofluorene (2,7-diaminofluorene), 4,4-diaminooctafluorobiphenyl, m-phenylenediamine (m- phenylenediamine), p-phenylenediamine, 4,4'-oxydianiline, 2,2'-dimethyl-4,4'-diaminobiphenyl (2, 2'-dimethyl-4,4'-diaminobiphenyl), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (2,2-bis[4-(4-aminophenoxy)phenyl]propane), In the group consisting of 1,3-bis(4-aminophenoxy)benzene (1,3-bis(4-aminophenoxy)benzene), and 4,4'-diaminobenzanilide (4,4'-diaminobenzanilide) Polyamideimide copolymer, which is one or more compounds selected.
The method of claim 1,
The aromatic dianhydride compound is 3,3',4,4'-biphenyltetracarboxylic dianhydride (3,3',4,4'-biphenyltetracarboxylic dianhydride), 4,4'- (hexafluoro Isopropylidene)diphthalic anhydride (4,4'-(hexafluoroisopropylidene)diphthalic anhydride), 2,2'-bis-(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (2,2' -bis-(3,4-dicarboxyphenyl)hexafluoropropane dianhydride), benzophenone tetracarboxylic dianhydride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride ( benzophenone tetracarboxylic dianhydride), oxydiphthalic anhydride, cyclobutane-1,2,3,4-tetracarboxylic dianhydride (cyclobutane-1,2,3,4-tetracarboxylic dianhydride), cyclo At least one compound selected from the group consisting of pentane tetracarboxylic dianhydride, and bis(3,4-dicarboxyphenyl)sulfone dianhydride (bis(3,4-dicarboxyphenyl)sulfone dianhydride) Phosphorus, polyamideimide copolymer.
The method of claim 1,
The polyamideimide copolymer has a number average molecular weight (Mn) of 250,000 g/mol or more and a weight average molecular weight (Mw) of 500,000 g/mol or more.
An optical film comprising the polyamideimide copolymer of claim 1.
The method of claim 8,
The optical film has an elastic modulus of 6.00 GPa or more, measured according to the standard test method of ASTM D882 for a film specimen having a thickness of 50 ± 5 µm.

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