KR20180106212A - Polyimide Resin, Polyimide Film and Display Device Comprising Thereof - Google Patents

Abstract

The present invention relates to a polyimide resin, a polyimide film, and an image display device comprising the polyimide film. According to the present invention, the polyimide film has advantages suitable for using as a substrate material of a display device having excellent optical characteristics and heat resistance, and can secure excellent solvent resistance while maintaining the characteristics of a conventional transparent polyimide film.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a polyimide resin, a polyimide film,

TECHNICAL FIELD The present invention relates to a polyimide resin, a polyimide film and a display substrate module comprising the polyimide resin, and more specifically to a polyimide resin having excellent solvent resistance and excellent optical properties and heat resistance, To a video display device.

In general, a polyimide (PI) film is a film made of a polyimide resin, and a polyimide resin is produced by solution polymerization of an aromatic dianhydride and an aromatic diamine or aromatic diisocyanate to prepare a polyamic acid derivative, Refers to a high heat-resistant resin produced by imidization.

Such a polyimide film has excellent mechanical, heat resistance and electrical insulation properties and is used in a wide range of electronic materials such as a semiconductor insulating film, a substrate for a flexible printed wiring circuit of a TFT-LCD electrode protective film, and the like.

However, the polyimide resin is colored in brown and yellow due to its high aromatic ring density, and thus has low transmittance in the visible light region and yellowish color to lower the light transmittance and has a large birefringence, making it difficult to use the polyimide resin as an optical member have.

To solve this problem, a method of polymerizing a polyimide containing an alicyclic monomer or a fluorene structure has been attempted in order to obtain a highly transparent polyimide.

Japanese Patent Publication Nos. 2005-015629 and 2005-163012 and 2006-070096 disclose contents of polyimide polymerization containing alicyclic monomers and fluorene structures. In the case of using alicyclic monomers, charge transfer complex formation But it is not enough to be used as a display element material for OLED, TFT-LCD, and flexible display in terms of mechanical properties, heat resistance and birefringence in view of the result that thermal and mechanical properties are deteriorated .

In the case of the colorless transparent alicyclic polyimide which is being developed in this way, the solvent resistance characteristic of the resin is degraded. When it is used in the form of a film such as a display substrate, it is exposed to a developer such as polar solvent, acid, There is a limitation in that the surface is melted or swelled and its shape is changed, so that it is difficult to lose its function or to use it without a protective layer.

In the present invention, the present invention provides a polyimide resin and a film thereof suitable for use as a substrate material of a display device having excellent optical properties and heat resistance, which retains the characteristics possessed by the conventional transparent polyimide film and has excellent solvent resistance The purpose.

The present invention also provides an image display device comprising a film made of the polyimide resin.

A preferred embodiment of the present invention for solving the above-mentioned problems is a method for producing a polymer electrolyte membrane comprising a unit structure derived from bistrifluoromethyldiaminophenyl ether (6FODA) and a unit structure derived from one aromatic dianhydride monomer 1 block; And a second block comprising a unit structure derived from one kind of aromatic diamine-based monomer and a unit structure derived from 1,4-cyclohexanedicarbonyl dichloride (1,4-CHDC) And a polyimide resin.

And the second block is contained at a molar ratio of 2.3 to 4.0 with respect to 1 mole of the first block.

The aromatic dianhydride monomer may be selected from the group consisting of oxydiphthalic dianhydride (ODPA), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanediamine hydride (6FDA), biphenyltetracarboxylic dianhydride (BPDA), and 3,3'4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA).

The aromatic diamine-based monomer is one selected from the group consisting of bistrifluoromethylbenzidine (TFDB), bis (3-aminophenyl) sulfone (3DDS), and bis (4-aminophenyl) sulfone.

In another preferred embodiment of the present invention, a first block is formed by copolymerizing bistrifluoromethyldiaminophenyl ether (6FODA) and one kind of aromatic dianhydride monomer to form an aromatic diamine compound Monomer and 1,4-cyclohexanedicarbonyl dichloride to form a second block. The present invention also provides a method for producing a polyimide resin.

And then adding 1,4-cyclohexanedicarbonyl dichloride having a cis content of 70 wt% or more in the step of forming the second block.

The aromatic dianhydride monomer may be selected from the group consisting of oxydiphthalic dianhydride (ODPA), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanediamine hydride (6FDA), biphenyltetracarboxylic dianhydride (BPDA), and 3,3'4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA).

The aromatic diamine-based monomer is one selected from the group consisting of bistrifluoromethylbenzidine (TFDB), bis (3-aminophenyl) sulfone (3DDS), and bis (4-aminophenyl) sulfone.

Another preferred embodiment of the present invention is to provide a polyimide film comprising the polyimide resin according to the above embodiment.

The polyimide film has a transmittance of 90% or more as measured at 550 nm based on a film thickness of 10 to 15 탆, and has a measured solvent resistance index of 2.0% or less as measured by the following method.

<Method of measuring solvent resistance index>

The polyimide film was taken in a 5 cm × 5 cm sample, dried in a vacuum oven at 80 ° C. for 1 hour, and the average thickness was measured from five arbitrary points on the film, and this value was defined as T ₀ . Then, the film was washed with DI Water, dried in a vacuum oven at 80 ° C for 1 hour, and an average thickness was measured from five arbitrary points on the film. The value was defined as T ₁ .

Using the values of T ₀ and T ₁ obtained above, the solvent resistance index was calculated from the following Equation 1, which is defined as the thickness deviation before and after immersion.

<Formula 1>

(T ₀ - T ₁ ) / T ₀ × 100 (%)

Another preferred embodiment of the present invention provides an image display device including the polyimide film according to the above embodiment.

According to the present invention, there is provided a polyimide resin suitable for use as a substrate material of a display element having excellent optical properties and heat resistance while retaining characteristics of a conventional transparent polyimide film while ensuring solvent resistance, and polyimide A film can be provided.

According to an aspect of the present invention, there is provided a process for producing a polymer electrolyte membrane comprising: a first block comprising a unit structure derived from bistrifluoromethyldiaminophenyl ether (6FODA) and a unit structure derived from one aromatic dianhydride monomer; And a second block comprising a unit structure derived from an aromatic diamine-based monomer of one kind and a unit structure derived from 1,4-cyclohexanedicarbonyl dichloride (1,4-CHDC) Resin can be provided. .

The polyimide resin is a block copolymer including the first block and the second block. The second block having a high elongation, a low CTE and a high permeability but no solvent resistance has a solvent resistance and a high permeability And the second block having the second block has a copolymer structure, it is possible to obtain the effect of compensating for the weakness of each block. That is, the polyimide block copolymer resin of the present patent can be divided into a block having no solvent resistance and a block having a solvent resistance, and in the case of the second block having no solvent resistance, an alicyclic monomer is used, In order to minimize the deterioration of the optical characteristics and elongation properties of the second block when the first block having solvent resistance exhibits a property using a diamine having a high elongation and a low CTE and forms a copolymer structure with the second block 6FODA monomers having ether groups and -CF ₃ groups at the same time.

Specifically, when 1,4-cyclohexanedicarbonyl dichloride (1,4-CHDC) is an alicyclic monomer, when an alicyclic monomer is used, the permeability is improved, but mechanical properties, heat resistance, There is a problem that the chemical properties are deteriorated.

Among alicyclic monomers, 1,4-CHDC has an isomer structure, so that it is applied to a polyimide resin together with dianhydride and diamine, and the degree of polymerization is lower than that of some monomers, so that a resin having sufficient high molecular weight may not be obtained have.

In the present invention, cyclohexane-1,4-dicarbonyl dichloride, which is an alicyclic monomer, is introduced into the second block together with an aromatic diamine-based monomer, and bistrifluoromethyldiaminophenyl ether ( 6FODA) and an aromatic dianhydride-based monomer, and has a high elongation and low linear thermal expansion coefficient (CTE) characteristics sufficient for use in a transparent substrate of an image display device while remarkably improving transparency. Can be secured.

The second block is preferably contained in a molar ratio of 2.3 to 4.0, preferably 3.0 to 3.5, to 1 mole of the first block. If the content of the second block is less than 2.3, the content of the first block having chemical resistance but lower in optical characteristics is higher than that of the second block, so that the optical characteristic may be lowered. On the other hand, The content of the first block, which is a structure, is lowered, causing swelling and clouding, which may make it difficult to apply it to substrate applications.

The aromatic dianhydride monomer may be selected from the group consisting of oxydiphthalic dianhydride (ODPA), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanediamine hydride (6FDA), biphenyltetracarboxylic dianhydride (BPDA), and 3,3'4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA).

The aromatic diamine-based monomer is preferably one selected from bistrifluoromethylbenzidine (TFDB), bis (3-aminophenyl) sulfone (3DDS), and bis (4-aminophenyl) sulfone.

The polyimide resin comprising the first block and the second block may be a copolymer including a block structure represented by the following general formula (1).

&Lt; Formula 1 >

(In the above formula, x means a molar fraction of 0.75.)

The repeating unit of 1-x in the above formula (1) corresponds to the first block, and includes a unit structure derived from 6FODA and an aromatic dianhydride-based monomer having a unit structure derived from BPDA, 2 block. The aromatic diamine-based monomer has a unit structure derived from bistrifluoromethylbenzidine (TFDB) and a unit structure derived from 1,4-CHDC.

In another embodiment of the present invention, the above-mentioned polyimide resin is copolymerized with bistrifluoromethyldiaminophenyl ether (6FODA) and an aromatic dianhydride monomer to form a first block, and then an aromatic diamine series resin Monomer and 1,4-CHDC to form a second block.

The step of copolymerizing the first block and the second block may be carried out in such a manner that the equivalent ratio of the diamine and the dianhydride monomer, that is, bistrifluoromethyldiaminophenyl ether (6FODA) and the aromatic dianhydride monomer is 1: 1, Based monomer and 1,4-CHDC in an equivalent ratio of 1: 1, and the mixture is polymerized in a nitrogen or argon atmosphere at a reaction temperature of -10 to 100 ° C and a reaction time of 2 to 48 hours to prepare a polyamic acid.

Although the content of the solvent is not particularly limited, the content of the solvent for polymerization (first solvent) in the polyamic acid solution is preferably 50 to 95% by weight, more preferably, More preferably 70 to 90% by weight. The polyamic acid solution thus prepared can be imidized to produce a polyimide resin.

At this time, it is preferable to add 1,4-CHDC having a cis content of 70 wt% or more in the step of forming the second block.

Specifically, 1,4-CHDC used to form the second block can be used as a mixture having a cis and trans structure. The content of 1,4-CHDC having a cis structure of 1,4-CHDC The higher the 1,4-CHDC, the higher the degree of polymerization of the resin as a whole, and the higher the degree of polymerization of the whole resin. The higher the 1,4-CHDC, the more preferably 80 to 100% %, It may have an effect of reducing the intra-chain steric hindrance which lowers the degree of polymerization.

When the 1,4-CHDC monomer used in the form of a mixture having the cis and trans structures forms the second block, the structure of the second block of the polyimide resin as the final material also has a unit structure derived from 1,4-CHDC May have a structure of cis and trans, and the unit structure derived from 1,4-CHDC contained in the second block may have a structure of at least 70% by weight or more By weight, preferably 80 to 90% by weight, and more preferably 90 to 100% by weight, to obtain a resin having a sufficient molecular weight to be utilized as a substrate.

Then, in the preparation of the polyimide resin by imidizing the polyamic acid solution, the imidization method to be applied is a thermal imidization method, a chemical imidization method, a thermal imidization method or a chemical imidation method in combination Can be applied.

According to another embodiment of the present invention, there is provided a polyimide film comprising the above-mentioned polyimide resin.

In the method for producing a polyimide film according to the present invention, in the step of casting and polymerizing the above-mentioned polymerized polyamic acid in a support, a known method such as a thermal imidation method, a chemical imidation method, The chemical imidation method can be used in combination.

The thermal imidation method is a method in which a polyamic acid solution is cast on a support and heated for 1 to 8 hours while gradually heating the solution in a temperature range of 40 to 280 ° C to obtain a polyimide film.

In the chemical imidation method, a dehydrating agent represented by an acid anhydride such as acetic anhydride and a imidation catalyst represented by tertiary amines such as isoquinoline, β-picoline, and pyridine are added to the polyamic acid solution. When the thermal imidation method or the thermal imidization method is used in combination with the chemical imidation method, the heating conditions of the polyamic acid solution may be varied depending on the type of the polyamic acid solution, the thickness of the polyimide film to be produced, and the like.

More specifically, a polyimide film production example in which the thermal imidation method and the chemical imidization method are used in combination is described. More specifically, a polyimamic acid solution is loaded with a dehydrating agent and an imidation catalyst, cast on a support, Preferably 100 to 180 占 폚 to activate the dehydrating agent and the imidation catalyst to partially cure and dry it, and then heated at 200 to 280 占 폚 for 5 to 400 seconds to obtain a polyimide film.

In the present invention, a polyimide film may be prepared from the polyamic acid solution as follows. Namely, after the obtained polyamic acid solution is imidized, the imidized solution is put into a second solvent, followed by precipitation, filtration and drying to obtain a solid content of the polyimide resin, and the solid content of the obtained polyimide resin is added to the first solvent Can be obtained through a film-forming process using a dissolved polyimide solution.

The first solvent may be the same solvent as that used in the polymerization of the polyamic acid solution. The second solvent may be one having a lower polarity than the first solvent in order to obtain the solid content of the polyimide resin, Alcohols, ethers, and ketones. At this time, the content of the second solvent is not particularly limited, but is preferably 5 to 25% by weight based on the weight of the polyamic acid solution.

It is preferable that the polyimide resin solids obtained as described above are filtered and dried by considering the boiling point of the second solvent at a temperature of 50 to 120 ° C and a time of 3 to 24 hours. Thereafter, the polyimide solution in which the polyimide resin solids are dissolved is cast on a support and heated at a temperature in the range of 40 to 280 DEG C for 10 minutes to 8 hours to obtain a polyimide film.

The polyimide film obtained by the method as described above has such characteristics that no phenomenon such as decomposition, swelling, and cloudiness occurs when immersed in a polar solvent for 5 minutes, and there is no change in thickness or haze before and after immersion .

That is, the polyimide film is preferably as low as 2.0% or less as measured according to the following method, and has a solvent resistance index below 1.90%, 0.58%, 0.49%, 0.48%, 0.45% have.

<Method of measuring solvent resistance index>

The polyimide film was taken in a 5 cm × 5 cm sample, dried in a vacuum oven at 80 ° C. for 1 hour, and the average thickness was measured from five arbitrary points on the film, and this value was defined as T ₀ . Then, the film was washed with DI Water, dried in a vacuum oven at 80 ° C for 1 hour, and an average thickness was measured from five arbitrary points on the film. The value was defined as T ₁ .

Using the values of T ₀ and T ₁ obtained above, the solvent resistance index was calculated from the following Equation 1, which is defined as the thickness deviation before and after immersion.

<Formula 1>

(T ₀ - T ₁ ) / T ₀ × 100 (%)

The polyimide film according to the present invention has a linear thermal expansion coefficient (CTE) of 50 ppm / ° C, measured repeatedly at 50 to 250 ° C twice by a thermal deformation analysis method (TMA-Method) And has a coefficient of thermal expansion of not higher than 41.2 ppm / ° C, 43.3 ppm / ° C, 45.5 ppm / ° C, 45.7 ppm / ° C, 47.2 ppm / ° C, 47.8 ppm / .

Also, the polyimide film according to the present invention preferably has a transmittance of at least 90%, preferably 90.1%, 90.3%, 90.5% and 90.7% It can have transparency.

The polyimide film according to the present invention preferably has a yellowing degree of less than 4.0 and a yellowing degree of 1.98, 2.41, 2.62, 2.77, 2.91, 2.94, 2.95, Lt; / RTI &gt;

Also, the polyimide film according to the present invention is preferred as the elongation measured with ASTM D882 (film thickness 10 to 50 탆) as high as 10% or more, 15.7%, 17.2%, 17.5%, 18.1%, 21.8% , 22.7%, and 25.2%, respectively.

The physical properties such as transmittance, yellowness, thermal expansion coefficient, and the like are measured when the film has a thickness in the range of 10 to 15 mu m, for example, 11 mu m, 12 mu m, 13 mu m, 15 [mu] m, and the film within the thickness can be measured to satisfy all of the physical properties. Similarly, the physical properties of the elongation described above can be measured by measuring a film having a thickness in the range of 10 to 15 mu m, for example, 11 mu m, 12 mu m, 13 mu m, 15 [mu] m, and the film within the thickness can be measured to satisfy all of the physical properties. At this time, the thickness range of the film corresponds to a measuring method for measuring the physical properties, and does not mean to limit the thickness of the film unless specifically mentioned.

In addition, the polyimide film according to the present invention is characterized by satisfying all of the above physical properties, that is, the solvent resistance, the transmittance, the yellowness degree, the thermal expansion coefficient and the elongation.

By applying the polyimide film of the present invention to a substrate for an image display device such as a flexible display, it is possible to obtain a colorless transparent substrate having excellent solvent resistance, easy processability, excellent optical characteristics and high heat resistance high- There is a good advantage.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for the purpose of illustrating the present invention more specifically, and the present invention is not limited thereto.

< Example  1>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 299.489 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.070 g (0.024 mol) of 6FODA, . After 6FODA dissolution was completed, 6.991g (0.02376mol) of BPDA was added, dissolved and allowed to react for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.758 g (0.05624 mol) of 14CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 ° C., and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid content of 13% by weight and a viscosity of 240 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Example  2>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 294.073 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 5.380 g (0.016 mol) of 6FODA, . After the dissolution of 6FODA was completed, 4.637g (0.01576mol) of BPDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 20.495 g (0.064 mol) of TFDB was added and 13.431 g (0.06424 mol) of 14CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 ° C., and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13% by weight and a viscosity of 290 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Example  3>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 282.927 g of dimethylacetamide (DMAc) was charged while passing nitrogen through the reactor, and 9.061 g (0.021 mol) of 6FODA, . After 6FODA dissolution was completed, 9.236g (0.02079mol) of 6FDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 15.691 g (0.049 mol) of TFDB was added, and 10.288 g (0.04921 mol) of 14 CHDC was added after the completion of TFDB dissolution. Thereafter, the temperature of the solution was maintained at 25 DEG C, and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13 wt% and a viscosity of 180 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 11 탆 was prepared.

< Example  4>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 302.030 g of dimethylacetamide (DMAc) was charged while passing nitrogen through the reactor, and 8.070 g (0.024 mol) of 6FODA, . After the dissolution of 6FODA was completed, 7.370 g (0.02376 mol) of 44 ODPA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.758 g (0.05624 mol) of 14CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 DEG C and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid content of 13 wt% and a viscosity of 210 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Example  5>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 309.675 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.070 g (0.024 mol) of 6FODA, . After 6FODA dissolution was completed, 8.513g (0.02376mol) of DSDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.758 g (0.05624 mol) of 14CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 DEG C, and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13 wt% and a viscosity of 110 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Example  6>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 272.531 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.070 g (0.024 mol) of 6FODA, . After 6FODA dissolution was completed, 6.991g (0.02376mol) of BPDA was added, dissolved and allowed to react for 24 hours. After 24 hours, 13.905 g (0.056 mol) of 3DDS was added, and after dissolution of 3DDS, 14.758 g (0.05624 mol) of 14CHDC was added. Thereafter, the temperature of the solution was maintained at 25 DEG C and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid content of 13 wt% and a viscosity of 70 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Example  7>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 272.531 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.070 g (0.024 mol) of 6FODA, . After 6FODA dissolution was completed, 6.991g (0.02376mol) of BPDA was added, dissolved and allowed to react for 24 hours. After 24 hours, 13,905 g (0.056 mol) of 4DDS was added, and after dissolution of 4 DDS was completed, 14 CHDC (11.758 g, 0.05624 mol) was added. Thereafter, the temperature of the solution was maintained at 25 DEG C, and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13 wt% and a viscosity of 95 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  1>

283.379 g of dimethylacetamide (DMAc) was charged into a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser while passing nitrogen, and 25.618 g (0.08 mol) of TFDB, . After the dissolution of TFDB was completed, 16.726 g (0.08 mol) of 14CHDC was added and dissolved, and the temperature of the solution was maintained at 25 ° C for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13% by weight and a viscosity of 355 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  2>

Into a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 303.667 g of dimethylacetamide (DMAc) was charged while passing nitrogen, 28.580 g (0.085 mol) of 6FODA, . After completion of 6FODA dissolution, 25.009g (0.085mol) of BPDA was added and dissolved. The temperature of the solution was maintained at 25 ° C and the reaction was allowed to proceed for 24 hours. As a result, a polyamic acid solution having a solid concentration of 15% by weight and a viscosity of 385 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  3>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 309.590 g of dimethylacetamide (DMAc) was charged while passing nitrogen, 23.536 g (0.070 mol) of 6FODA, . After 6FODA dissolution was completed, 31.098g (0.070mol) of 6FDA was added and dissolved, and the temperature of the solution was maintained at 25 ° C and reacted for 24 hours. As a result, a polyamic acid solution having a solid concentration of 15% by weight and a viscosity of 143 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  4>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 312.345 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 5.405 g (0.027 mol) of 44ODA, . After completion of the dissolution of 44 ODA, 7.865 g (0.02673 mol) of BPDA was added, dissolved, and reacted for 24 hours. After 24 hours, 20.174 g (0.063 mol) of TFDB was added, and 13.228 g (0.06327 mol) of 14 CHDC was added after the completion of TFDB dissolution. Thereafter, the temperature of the solution was maintained at 25 ° C., and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13% by weight and a viscosity of 720 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 11 탆 was prepared.

< Comparative Example  5>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 301.496 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 4.805 g (0.024 mol) of 44ODA, . After completion of the dissolution of 44ODA, 10.555g (0.02376mol) of 6FDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.758 g (0.05624 mol) of 14CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 DEG C and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid content of 13 wt% and a viscosity of 327 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  6>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 285.366 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and then 5.959 g (0.024 mol) of 4DDS, . After dissolution of 4DDS was completed, 6.991 g (0.02376 mol) of BPDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.758 g (0.05624 mol) of 14CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 degrees, and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid content of 13 wt% and a viscosity of 113 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  7>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 309.222 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and then 5.959 g (0.024 mol) of 4DDS, . After dissolution of 4DDS was completed, 10.555g (0.02376mol) of 6FDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.758 g (0.05624 mol) of 14CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 DEG C, and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid content of 13 wt% and a viscosity of 72 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  8>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 296.804 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and then 3.083 g (0.027 mol) of tCHD, . After completion of the tCHD dissolution, 7.865 g (0.02673 mol) of BPDA was added, dissolved and reacted for 24 hours. After 24 hours, 20.174 g (0.063 mol) of TFDB was added, and 13.228 g (0.06327 mol) of 14 CHDC was added after the completion of TFDB dissolution. Thereafter, the temperature of the solution was maintained at 25 DEG C, and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13 wt% and a viscosity of 395 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 11 탆 was prepared.

< Comparative Example  9>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 287.682 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 2.741 g (0.024 mol) of tCHD, . After the tCHD dissolution was completed, 10.555 g (0.02376 mol) of 6FDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.758 g (0.05624 mol) of 14CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 ° C., and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13% by weight and a viscosity of 105 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  10>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 297.211 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.070 g (0.024 mol) of 6FODA, . After 6FODA dissolution was completed, 6.991g (0.02376mol) of BPDA was added, dissolved and allowed to react for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.418 g (0.05624 mol) of TPC was added after completion of TFDB dissolution. Thereafter, the temperature of the solution was maintained at 25 DEG C, and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13 wt% and a viscosity of 557 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  11>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 297.211 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.070 g (0.024 mol) of 6FODA, . After 6FODA dissolution was completed, 6.991g (0.02376mol) of BPDA was added, dissolved and allowed to react for 24 hours. After 24 hours, 17.933 g (0.056 mol) of TFDB was added, and 11.418 g (0.05624 mol) of IPC was added after TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 DEG C and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid content of 13 wt% and a viscosity of 210 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 11 탆 was prepared.

< Comparative Example  12>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 299.625 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.070 g (0.024 mol) of 6FODA, And 17.933 g (0.056 mol) of TFDB were added and dissolved. After the dissolution of 6FODA and TFDB was completed, 7.061g (0.024mol) of BPDA and 11.708g (0.056mol) of 14CHDC were added and reacted for 24 hours while maintaining 25 ° C. As a result, a polyamic acid solution having a solid concentration of 13 wt% and a viscosity of 172 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 11 탆 was prepared.

< Comparative Example  13>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 323.722 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.070 g (0.024 mol) of 6FODA, And 17.933 g (0.056 mol) of TFDB were added and dissolved. After dissolution of 6FODA and TFDB was completed, 10.662g (0.024mol) of 6FDA and 11.708g (0.056mol) of 14CHDC were added and reacted for 24 hours while maintaining 25 ° C. As a result, a polyamic acid solution having a solid concentration of 13% by weight and a viscosity of 115 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  14>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 292.449 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 4.573 g (0.0136 mol) of 6FODA, . After 6FODA dissolution was completed, 3.931 g (0.01336 mol) of BPDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 21.263 g (0.0664 mol) of TFDB was added and 13.932 g (0.06664 mol) of 14 CHDC was added after the TFDB dissolution was completed. Thereafter, the temperature of the solution was maintained at 25 DEG C and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13 wt% and a viscosity of 315 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

< Comparative Example  15>

In a 500 ml reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser, 301.113 g of dimethylacetamide (DMAc) was charged while passing nitrogen, and 8.876 g (0.0264 mol) of 6FODA, . After 6FODA dissolution was completed, 7.697g (0.02616mol) of BPDA was added and dissolved, followed by reaction for 24 hours. After 24 hours, 17.164 g (0.0536 mol) of TFDB was added, and 11.256 g (0.05384 mol) of 14CHDC was added after the completion of TFDB dissolution. Thereafter, the temperature of the solution was maintained at 25 DEG C, and the reaction was carried out for 24 hours. As a result, a polyamic acid solution having a solid concentration of 13 wt% and a viscosity of 218 poise was obtained. After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast to 10 to 20 占 퐉, dried by hot air at 80 占 폚 for 20 minutes, at 120 占 폚 for 20 minutes and at 280 占 폚 for 10 minutes by hot air, And a polyimide film having a thickness of 10 탆 was prepared.

The properties of the polyimide films prepared in Examples and Comparative Examples were evaluated by the following methods. The results are shown in Tables 1 and 2 below.

How to measure

The properties of the polyimide films prepared in Examples and Comparative Examples were evaluated by the following methods. The results are shown in Tables 1 and 2 below.

(1) Measurement of permeability

The transmittance was measured three times at 550 nm using a UV spectrometer (Kotikaminolta CM-3700d) and the average values are shown in Table 1.

(2) Haze measurement

The mean value was measured three times using Hazemeter (Murakami Color Research Laboratory, HM-150).

(3) Yellowness (Y.I.) measurement

Yellowness was measured according to ASTM E313 standard using a UV spectrometer (Konita Minolta, CM-3700d).

(4) Coefficient of thermal expansion (CTE) measurement

Using TMA (TA Instrument, Q400), linear thermal expansion coefficients were measured twice at 50 ~ 250 according to the TMA-method. The size of the specimen was 4 mm × 24 mm, the load was 0.02 N, and the rate of temperature rise was 10 / min.

Since the residual stress may remain in the film through the film formation and heat treatment, the residual stress is completely removed in the first run and the second value is presented as the measured value.

(5) elongation (%) measurement

Measured according to ASTM-D882 standard using 5967 from Instron. The size of the specimen was measured as 15 mm × 30 mm, Load cell 1 KN, and Tension rate 10 mm / min.

(6) Solvent resistance measurement

The polyimide films prepared in Examples and Comparative Examples were taken with a 5 cm × 5 cm sample, dried in a vacuum oven at 80 ° C. for 1 hour, and the average thickness was measured from five arbitrary points on the film, and this value was defined as T ₀ . Subsequently, the film was dipped in a 100% DMAC solution for 5 minutes to confirm the decomposition of the film. The film was washed with DI Water only for the undissolved film, and then dried in a vacuum oven at 80 ° C for 1 hour. And this value was defined as T ₁ .

Using the values of T ₀ and T ₁ obtained above, the solvent resistance index was calculated from the following Equation 1, which is defined as the thickness deviation before and after immersion.

&Lt; Visually inspected result of film after immersion >

O: No decomposition, swelling or clouding of the film occurs.

X: The film is decomposed, swelling or clouding occurs.

<Formula 1>

(T ₀ - T ₁ ) / T ₀ × 100 (%)

division ingredient rescue 14CHD
Cis content
(weight%) The mole ratio of the second block to one mole of the first block film
thickness
(탆) Y.I. 550 nm
Permeability CTE
(ppm / DEG C) Elongation
(%) The first block The second block Example
One 6FODA-BPDA TFDB-14CHDC Block 70 2.3 10 2.95 90.1 43.3 22.7 Example
2 6FODA-BPDA TFDB-14CHDC Block 70 4.0 10 2.41 90.5 41.2 25.2 Example
3 6FODA-6FDA TFDB-14CHDC Block 70 2.3 11 1.98 90.7 48.7 17.5 Example
4 6FODA-4,4'ODPA TFDB-14CHDC Block 70 2.3 10 2.77 90.3 45.5 21.8 Example
5 6FODA-DSDA TFDB-14CHDC Block 70 2.3 10 2.62 90.3 47.8 18.1 Example
6 6FODA-BPDA 3DDS-14CHDC Block 70 2.3 10 2.91 90.1 47.2 15.7 Example
7 6FODA-BPDA 4DDS-14CHDC Block 70 4.0 10 2.94 90.1 45.7 17.2 Comparative Example
One - TFDB-14CHDC - 70 - 10 1.01 90.8 28.5 35.7 Comparative Example
2 6FODA-BPDA - - - - 10 6.90 88.8 56 18.1 Comparative Example
3 6FODA-6FDA - - - - 10 2.70 89.8 67.8 9.57 Comparative Example
4 44ODA-BPDA TFDB-14CHDC Block 70 2.3 11 5.88 88.5 43.1 24.5 Comparative Example
5 44ODA-6FDA TFDB-14CHDC Block 70 2.3 10 5.31 88.6 47.5 18.2 Comparative Example
6 4DDS-BPDA TFDB-14CHDC Block 70 2.3 10 5.12 88.5 44.2 13.5 Comparative Example
7 4DDS-6FDA TFDB-14CHDC Block 70 2.3 10 4.98 88.5 48.7 11.2 Comparative Example
8 tCHD-BPDA TFDB-14CHDC Block 70 2.3 11 1.15 90.4 28.8 34.3 Comparative Example
9 tCHD-6FDA TFDB-14CHDC Block 70 2.3 10 1.02 90.8 42.5 28.1 Comparative Example
10 6FODA-BPDA TFDB-TPC Block - 2.3 10 2.30 90.2 33.5 27.5 Comparative Example
11 6FODA-BPDA TFDB-IPC Block - 2.3 11 2.12 90.5 56.7 14.7 Comparative Example
12 6FODA 3: TFDB 7 -
BPDA 3: 14CHDC 7 Random 70 - 11 6.27 88.3 41.2 11.5 Comparative Example
13 6FODA 3: TFDB 7 -
6FDA 3: 14CHDC 7 Random 70 - 10 4.45 89.5 48.7 9.8 Comparative Example
14 6FODA-BPDA TFDB-14CHDC Block 70 4.88 10 2.27 90.5 40.9 25.4 Comparative Example
15 6FODA-BPDA TFDB-14CHDC Block 70 2.03 10 3.21 89.5 45.7 20.5

division ingredient Before immersion
Haze (%) After immersion
Haze (%) Solvent resistance The first block The second block Decomposition swelling cloudiness Solvent resistance index Example
One 6FODA-BPDA TFDB-14CHDC 0.6 0.6 O 0.49 Example
2 6FODA-BPDA TFDB-14CHDC 0.8 0.8 O 1.90 Example
3 6FODA-6FDA TFDB-14CHDC 0.5 0.5 O 0.45 Example
4 6FODA-4,4'ODPA TFDB-14CHDC 0.6 0.6 O 0.48 Example
5 6FODA-DSDA TFDB-14CHDC 0.6 0.6 O 0.48 Example
6 6FODA-BPDA 3DDS-14CHDC 0.5 0.5 O 0.48 Example
7 6FODA-BPDA 4DDS-14CHDC 0.5 0.5 O 0.58 Comparative Example
One - TFDB-14CHDC 1.5 -
(Measurement impossible) X
(decomposition) 100 Comparative Example
2 6FODA-BPDA - 0.4 0.4 O 0.47 Comparative Example
3 6FODA-6FDA - 0.3 0.3 O 0.95 Comparative Example
4 44ODA-BPDA TFDB-14CHDC 0.6 0.6 O 0.63 Comparative Example
5 44ODA-6FDA TFDB-14CHDC 0.6 0.6 O 0.96 Comparative Example
6 4DDS-BPDA TFDB-14CHDC 0.5 5.7 X
(Cloudiness, swelling) 9.52 Comparative Example
7 4DDS-6FDA TFDB-14CHDC 0.5 4.5 X
(Cloudiness, swelling) 17.75 Comparative Example
8 tCHD-BPDA TFDB-14CHDC 1.1 20.1 X
(Cloudiness, swelling) 61.26 Comparative Example
9 tCHD-6FDA TFDB-14CHDC 0.9 -
(Measurement impossible) X
(decomposition) 100 Comparative Example
10 6FODA-BPDA TFDB-TPC 1.4 -
(Measurement impossible) X
(decomposition) 100 Comparative Example
11 6FODA-BPDA TFDB-IPC 1.3 1.3 O 0.89 Comparative Example
12 6FODA 3: TFDB 7 -
BPDA 3: 14CHDC 7 0.9 0.9 O 1.80 Comparative Example
13 6FODA 3: TFDB 7 -
6FDA 3: 14CHDC 7 1.1 1.1 O 2.77 Comparative Example
14 6FODA-BPDA TFDB-14CHDC 1.0 2.7 X
(Cloudiness, swelling) 5.76 Comparative Example
15 6FODA-BPDA TFDB-14CHDC 0.6 0.6 O 0.66

As shown in Tables 1 and 2, when the polyimide films of Examples 1 to 5 were compared with Comparative Examples 1 to 15, when the block ratio of the unit block of the high elongation low CTE and the unit block having the solvent resistance was proper Heat resistance, mechanical properties and solvent resistance suitable for use as a substrate of an image display device.

It can be seen from the results of Comparative Examples 1 to 3 that the TFDB-14 CHDC unit block can not be used solely because of the solvent resistance problem, and the unit Blcok of the 6FODA-aromatic dianhydride can not be used alone due to the problem of optical and heat resistance. The results of Comparative Examples 14 and 15 show that when the Block ratio does not have an appropriate value, the solvent resistance of the final film is lowered (in the case of Comparative Example 14), or the optical and heat resistance is lowered (in the case of Comparative Example 15) Respectively.

Also, the results of Comparative Examples 4 to 9 show that when 6FDOA, which is an aromatic diamine monomer of a solvent block having solvent resistance, is replaced by a raw material such as 44ODA, 4DDS, tCHD, which is a raw material without -CF ₃ Group, As shown in Fig. In particular, when a DDS-based aromatic diamine monomer having a sulfone group or an alicyclic diamine-based monomer is used, the solvent resistance of the final film can not be ensured. In the case of 6FODA raw materials, since the ether group has a bent structure and -CF ₃ Group is included, it has advantages in improving the solvent resistance, optical properties and elongation, so that it can be confirmed once again by comparison with the comparative example .

The results of Comparative Examples 12 to 13 show that the polyimide films polymerized in a block structure and a random structure can be compared with each other. In the case of a random structure, the solvent resistance of the final film is the same, but all properties such as yellowness, light transmittance, heat resistance and elongation Is lower than that of the block structure. This is a result of random arrangement of the structure because the desired block structure can not be created due to the difference in reactivity between the raw materials.

The results of Comparative Examples 10 to 11 show that when the dicarbonyl dichloride monomer having a high elongation CTE structure is changed from alicyclic to aromatic, there is a decrease in solvent resistance (in the case of Comparative Example 10) or a decrease in heat resistance 11), and the like.

Claims (11)

A first block comprising a unit structure derived from bistrifluoromethyldiaminophenyl ether (6FODA) and a unit structure derived from one aromatic dianhydride monomer; And
A second block comprising a unit structure derived from one kind of aromatic diamine monomer and a unit structure derived from cyclohexanedicarbonyl dichloride (1,4-CHDC).
The polyimide resin according to claim 1, wherein the second block is contained at a molar ratio of 2.3 to 4.0 with respect to 1 mole of the first block.
The method of claim 1, wherein the aromatic dianhydride monomer is selected from the group consisting of oxydiphthalic dianhydride (ODPA), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanediamine hydrate (6FDA) Wherein the polyimide resin is one selected from the group consisting of phenyltetracarboxylic dianhydride (BPDA) and 3,3'4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA).
The method of claim 1, wherein the aromatic diamine monomer is one selected from the group consisting of bistrifluoromethylbenzidine (TFDB), bis (3-aminophenyl) sulfone (3DDS), and bis And a polyimide resin.
(6FODA) and one aromatic dianhydride-based monomer to form a first block, and then one aromatic diamine-based monomer and a cyclohexane-1,4- (1,4-CHDC) to form a second block. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt;
6. The method according to claim 5, wherein 1,4-cyclohexanedicarbonyl dichloride (1,4-CHDC) having a cis content of not less than 70% by weight is added in the step of forming the second block By weight based on the total weight of the polyimide resin.
The method of claim 5, wherein the aromatic dianhydride monomer is selected from the group consisting of oxydiphthalic dianhydride (ODPA), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanediamine hydrate (6FDA) Wherein the polyimide resin is one selected from the group consisting of phenyltetracarboxylic dianhydride (BPDA) and 3,3'4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA).
6. The method of claim 5, wherein the aromatic diamine-based monomer is one selected from the group consisting of bistrifluoromethylbenzidine (TFDB), bis (3-aminophenyl) sulfone (3DDS), and bis &Lt; / RTI &gt;
A polyimide film comprising a polyimide resin according to any one of claims 1 to 4.
The polyimide film according to claim 9, wherein the polyimide film has a transmittance of 90% or more measured at 550 nm on the basis of a film thickness of 10 to 15 占 퐉 and a measured solvent resistance index of not more than 2.0% .
<Method of measuring solvent resistance index>
The polyimide film was taken in a 5 cm × 5 cm sample, dried in a vacuum oven at 80 ° C. for 1 hour, and the average thickness was measured from five arbitrary points on the film, and this value was defined as T ₀ . Then, the film was washed with DI Water, dried in a vacuum oven at 80 ° C for 1 hour, and an average thickness was measured from five arbitrary points on the film. The value was defined as T ₁ .
Using the values of T ₀ and T ₁ obtained above, the solvent resistance index was calculated from the following Equation 1, which is defined as the thickness deviation before and after immersion.
<Formula 1>
(T ₀ - T ₁ ) / T ₀ × 100 (%)
An image display device comprising the polyimide film according to any one of claims 9 to 10.