KR20120033867A - Polyimide resin and film, alignment layer, substrate for display - Google Patents

Abstract

PURPOSE: A polyimide resin is provided to improve yellowness and light transmittance while not remarkably reducing physical properties, thermal stability, etc. CONSTITUTION: A polyimide resin comprises a unit structure originated from an aromatic dianhydride based monomer-aromatic diamine based monomer, and a unit structure originated from a cyclic dianhydride based monomer-cyclic diamine based monomer at the same time. The yellowness measured after forming membrane with the thickness of 50-100 micron is 30 or less, the light transmittance measured after forming membrane with the thickness of 50-100 micron by a UV spectrometer is 60% or more in the optical region of 500 nm. The polyimide resin comprises 20 mol% or more of the unit structure originated from the cyclic dianhydride based monomer-cyclic diamine based monomer.

Description

Polyimide resin and film, alignment layer, substrate for display

The present invention relates to a polyimide resin and a film, and more particularly, to a substrate for polyimide resin, a polyimide film, a polyimide alignment layer, and a polyimide display device having improved yellowness and light transmittance.

The general polyimide resin refers to a high heat resistant resin prepared by solution polymerization of an aromatic dianhydride and an aromatic diamine or an aromatic diisocyanate to prepare a polyamic acid derivative, and then imidation by ring dehydration at high temperature.

These polyimide resins are insoluble and insoluble ultra-high heat resistant resins, and have excellent properties such as heat oxidation resistance, heat resistance, radiation resistance, low temperature characteristics, chemical resistance, and the like. Heat-resistant advanced materials and insulation materials for automobile materials, aviation materials, and spacecraft materials BACKGROUND ART It is used in a wide range of fields for electronic materials such as coating agents, insulating films, semiconductors, electrode protective films of TFT-LCDs, and recently, it has been widely applied to display materials such as optical fibers and liquid crystal alignment films.

In order to manufacture such a polyimide resin, pyromellitic dianhydride (PMDA) or biphenyltetracarboxylic dianhydride (BPDA) is mainly used as an aromatic dianhydride component, and oxydianiline (Aromatic diamine component) is mainly used. ODA), p-phenylenediamine (p-PDA), m-phenylenediamine (m-PDA), methylenedianiline (MDA), bisaminophenylhexafluoropropane (HFDA), etc. are mainly used.

However, this polyimide resin has a problem in that it is difficult to manufacture in a solution state because of its low solubility after imidization has progressed, and thus it is difficult to use it for coating.In order to improve this, an aliphatic chain is mainly bonded to the side chain of diamine. Soluble polyimide was also prepared by the method, but the heat resistance was decreased due to the aliphatic chain, and due to the high aromatic ring density of the main chain of the polyimide, it was colored brown or yellow, and the yellowness was about 45 ~. It is so high that it is difficult to be used in the field where transparency is required as it is so high that it is about 95% and it is very low as about 30%.

The present invention provides a substrate for a polyimide resin, a film, an alignment film, and a display device having improved yellowness and light transmittance without significantly inhibiting physical properties such as mechanical and thermal stability of a general polyimide resin.

The polyimide resin of the present invention simultaneously contains a unit structure derived from an aromatic dianhydride monomer to an aromatic diamine monomer and a unit structure derived from an alicyclic dianhydride monomer to an alicyclic diamine monomer. After forming a film having a thickness of 100 μm, the measured yellowness is 30 or less after forming a film having a thickness of 50 to 100 μm that is 30 or less.

In addition, the polyimide resin of the present invention preferably forms a film having a thickness of 50 to 100 µm, and then the light transmittance measured by a UV spectrometer is preferably 60% or more in a 500 nm wavelength light region.

Further, the polyimide resin of the present invention is more preferably 20 mol% or more of the unit structure derived from an alicyclic dianhydride monomer or an alicyclic diamine monomer.

Here, the cycloaliphatic dianhydride monomer is 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride. Tide, Bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA) and 1,1'-bicyclohexane-3,3 ', 4,4'-tetracarboxylic dianhydride (H- BPDA), 1,2,4,5-cyclohexane-tetracarboxylic dianhydride (H-PMDA), Bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic2,3: 5,6 at least one selected from -dianhydride (7CI, 8CI), and the alicyclic diamine monomer is 2,2-bis (3-amino-4-hydroxy cyclohexyl) hexafluoropropane, 3,3'-dimethyl-4,4'- Diaminodicyclohexylmethane (MACM), 4,4'-methylenebicyclohexylamine (PACM), 1,3-bis (aminomethyl) cyclohexane (1,3-BAC ), 1,4-bis (aminomethyl) cyclohexane (1,4-BAC), cis-1,2-cyclohexanedimethanamine, trans-1,2-cyclohexanedimethanamine, bis (4-amino Cyclohexyl) ether (H-ODA), N- (4-aminocyclohexyl) -1,4-cyclohexanediamine.

The polyimide film, the orientation film, and the display element substrate of the present invention contain the polyimide resin.

The present invention provides a substrate for a polyimide resin, a film, an alignment layer, and a display device having improved yellowness and light transmittance without significantly inhibiting physical properties such as mechanical and thermal stability of a general polyimide resin.

The polyimide resin of the present invention is polymerized with a dianhydride monomer and a diamine monomer as main components, and has a unit structure derived from an aromatic dianhydride monomer or an aromatic diamine monomer, and an alicyclic dianhydride monomer to an alicyclic ring. By simultaneously including the unit structure derived from a group diamine type monomer, a polyimide resin can be adjusted low in the brown or yellow type color generate | occur | produced by aromatic.

At this time, the polyimide resin according to the present invention preferably has a yellowness of 30 or less after forming a film having a thickness of 50 to 100 µm. That is, if the yellowness is more than 30, there is a problem that the color reproduction and color reproducibility on the display are not good, and therefore, the yellowness is preferably adjusted to 30 or less, and such yellowness is lower as the numerical value is closer to zero. desirable.

In addition, the polyimide resin of the present invention preferably forms a film having a thickness of 50 to 100 μm, and then the light transmittance measured by a UV spectrometer is preferably 60% or more in a 500 nm wavelength light region. That is, if the transmittance in the 500 nm wavelength light region is less than 60% of the light wavelength in the visible light region, the brightness of the image on the implemented display screen is much lowered, so the sharpness of the image quality is lowered, so that the transmittance is adjusted to 60% or more. It is preferable that such transmittance is more preferable as the numerical value is close to 100%.

The polyimide resin of the present invention more preferably contains 20 mol% or more of a unit structure derived from an alicyclic dianhydride monomer or an alicyclic diamine monomer. That is, since the content of the unit structure derived from the alicyclic dianhydride monomer to the alicyclic diamine monomer is 20 mol% or more, the color of brown or yellow can be removed to adjust the yellowness to 30 or less. Physical properties such as mechanical properties and thermal stability, which are properties derived from the group dianhydride monomers to the alicyclic diamine monomers, may not be significantly impaired.

In order for the polyimide resin as described above to include a unit structure derived from a dianhydride monomer and a diamine monomer, i) the dianhydride monomer is an alicyclic dianhydride monomer, and the diamine monomer is an aliphatic diamine. Ii) the dianhydride monomer is an aliphatic dianhydride monomer, and the diamine monomer is an alicyclic diamine monomer, or iii) one of the dianhydride monomer or the diamine monomer is an aromatic monomer and an alicyclic monomer. It is a mixture of monomers, and the other is an aromatic monomer, or i) both dianhydride type monomer and a diamine type monomer can superpose | polymerize as a mixture of an aromatic monomer and an alicyclic monomer.

Here, as the alicyclic dianhydride monomer, preferably 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicar Cyclic Anhydride (TDA), Bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, Cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA) and 1,1'-bicyclohexane-3,3 ', 4,4'-tetracarboxylic dianhydride Lide (H-BPDA), 1,2,4,5-cyclohexane-tetracarboxylic dianhydride (H-PMDA), Bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic2,3 It may be at least one selected from: 5,6-dianhydride (7CI, 8CI).

In addition, the alicyclic diamine monomers are 2,2-bis (3-amino-4-hydroxy cyclohexyl) hexafluoropropane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (MACM), 4,4 '-Methylenebicyclohexylamine (PACM), 1,3-bis (aminomethyl) cyclohexane (1,3-BAC), 1,4-bis (aminomethyl) cyclohexane (1,4-BAC), cis -1,2-cyclohexanedimethanamine, trans-1,2-cyclohexanedimethanamine, bis (4-aminocyclohexyl) ether (H-ODA), N- (4-aminocyclohexyl) -1, It may be at least one selected from 4-cyclohexanediamine.

The aromatic anhydride monomers contained in the polyimide resin of the present invention may be pyromellitic dianhydride (PMDA), 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride (BPDA), Bis (3,4-dicarboxyphenyl) sulfone dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride Water, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,4-oxydiphthalic dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride , Bis (3,4-dicarboxyphenyl) methane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride , 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 1,3-bis (3,4-dicarboxyphenyl Propane dianhydride, 4,4'-hexafluoroisopropylidenediphthalic anhydride, 1, 2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, p-phenyl Lenbis (trimelitic acid monoester acid anhydride), ethylenebis (trimelitic acid monoester acid anhydride), bisphenol A bis (trimelitic acid monoester acid anhydride), 4,4 '-(4,4'-isopropyl It may be one containing at least one selected from lidene diphenoxy) bis (phthalic anhydride), p-phenylenediphthalic anhydride.

In addition, the aromatic diamine monomers include 1,4-diaminobenzene (p-phenylenediamine) (p-PDA), 1,3-diaminobenzene, 1,2-diaminobenzene, benzidine, 3,3'- Dichlorobenzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 3,3'-dihydroxybenzidine, 3,3 ', 5,5'-tetramethylbenzidine, 4,4'-dia Minodiphenylpropane, 4,4'-diaminodiphenylhexafluoropropane, 1,5-diaminonaphthalene, 4,4'-diaminodiphenyldiethylsilane, 4,4'-diaminodiphenylsilane , 4,4'-diaminodiphenylethylphosphine oxide, 4,4'-diaminodiphenyl N-methylamine, 4,4'-diaminodiphenyl N-phenylamine, 4,4'-dia Minodiphenyl ether (4,4'-ODA), 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl thioether, 3,4 '-Diaminodiphenyl thioether, 3,3'-diaminodiphenyl thioether, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diamino Diphenylmethane, 4,4 '-Diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzanilide, 3,4'-diaminobenzanilide, 3,3'-diaminobenzanilide, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, bis [4- (3-aminophenoxy ) Phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4- Aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 2,2- Bis [4- (3-aminophenoxy) phenyl] propane, 2, 2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl ] Butane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-amino Phenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene , 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-amino Phenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl ] Ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy C) benzoyl] benzene, 4,4'-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4'-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy ] Diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy)- , α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 4,4'-diaminodiphenylethylphosphine oxide, 1, 3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-Bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2'-bis (trifluoromethyl ) -4,4'-diaminobiphenyl (2,2'-TFDB), 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (MACM), 4,4'-methylenebicyclohexylamine ( PACM), 1,3-bis (aminomethyl) cyclohexane (1,3-BAC), 1,4-bis (aminomethyl) cyclohexane (1,4-BAC), cis-1,2-cyclohexanedi Methaneamine, trans-1,2-cyclohexanedimethanamine, bis (4-aminocyclohexyl) ether, N- (4-aminocyclohexyl) -1,4-cyclohexanediamine, M-Xylenediamine (MXDA) ( Cas no. 1477-55-0), P-Xylenediamine (PXDA) (Cas no. 539-48-0), 3,5-diaminobenzoic acid (DABA), BIS-AP-AF (83558-87-6) It may be included above.

As such, the polyimide resin of the present invention has a yellowness of 30 or less and a light transmittance of 60% or more in a 500 nm wavelength light region, thereby limiting its use due to the yellow color of the existing polyimide film, that is, Can be used in applications requiring transparency such as interlayers, gate insulators and liquid crystal alignment films in diffusion films and coating films in protective films or TFT-LCDs, such as TFT-LCDs, and when the transparent polyimide is applied as a liquid crystal alignment film, the aperture ratio is increased. By contributing to the high-contrast TFT-LCD, it is possible to manufacture. In addition, the present invention can be used for flexible electronic substrates such as flexible display substrates, solar cell lower or upper substrates, and transparent FPCBs.

The polyimide film, the orientation film, and the display element substrate of the present invention include the polyimide resin, and a method of manufacturing the same is as follows.

First, the dianhydride monomer and the diamine monomer are made into equimolar amounts, dissolved in an organic solvent, and reacted to prepare a polyamic acid solution.

The polyamic acid solution is reacted. The reaction conditions are not particularly limited, but the reaction temperature is preferably -20 to 80 ° C, the reaction time is preferably 2 to 48 hours, and the atmospheric conditions at the time of reaction are argon or It is more preferable that it is inert atmosphere, such as nitrogen.

The organic solvent which dissolves a dianhydride type monomer and a diamine type monomer will not be specifically limited if it is an organic solvent which can melt a polyamic acid. Known reaction solvents are selected from m-cresol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), acetone, diethyl acetate One or more polar solvents may be used, and in addition, a low boiling point solution such as tetrahydrofuran (THF), chloroform or a low absorbing solvent such as γ-butyrolactone may be used. The content of the organic solvent is not particularly limited, but in order to obtain the molecular weight and viscosity of the appropriate polyamic acid solution, 50 to 95% by weight of the total polyamic acid solution is preferable, and more preferably 70 to 90% by weight. desirable.

In addition, when preparing a polyimide film using a polyamic acid solution, a filler may be added to the polyamic acid solution for the purpose of improving various properties such as the slidability, thermal conductivity, conductivity, and corona resistance of the polyimide film. Although it does not specifically limit as a filler, As a preferable specific example, a silica, titanium oxide, layered silica, carbon nanotube, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica, etc. are mentioned. The particle diameter of the filler may vary depending on the characteristics of the film to be modified and the type of filler to be added, but is not particularly limited, but the average particle diameter is preferably 0.001-50 μm, more preferably 0.005-25 μm, More preferably, it is 0.01-10 micrometers. In this case, the modification effect of a polyimide film tends to appear, and favorable surface property, electroconductivity, and a mechanical characteristic can be acquired in a polyimide film. The amount of the filler added may vary depending on the film properties to be modified, the particle size of the filler, and the like, but it is preferably 0.001 to 20 parts by weight, more preferably 0.01 to 20 parts by weight of the polyamic acid solution. It is good that it is -10 weight part. The addition method of a filler is not specifically limited, For example, the method of adding to a polyamic-acid solution before superposition | polymerization or after superposition | polymerization, the method of kneading a filler using 3 rolls etc. after completion | finish of polyamic acid polymerization, the dispersion liquid containing filler The method of preparing and mixing this into a polyamic-acid solution, etc. are mentioned.

In the method for producing a polyimide film from the obtained polyamic acid solution, the polyamic acid solution can be cast on a support to imide to obtain a film.

As an imidation method applied at this time, the thermal imidation method, the chemical imidation method, the method of using together the thermal imidation method, and the chemical imidation method, etc. are applicable.

The chemical imidization method is a method of injecting an imidization catalyst represented by a dehydrating agent represented by an acid anhydride such as acetic anhydride and tertiary amines such as isoquinoline, β-picolin and pyridine into a polyamic acid solution.

The thermal imidization method is a method of applying heating conditions to a polyamic acid solution by varying the type of polyamic acid, the thickness of a polyimide film to be produced, and the like.

When explaining the production example of the polyimide film in the case of using the thermal imidation method and the chemical imidation method more specifically, 80-200 degreeC, after casting a dehydrating agent and an imidation catalyst in a polyamic-acid solution, and casting on a support body, Preferably, by heating at 100-180 ° C. to activate the dehydrating agent and the imidization catalyst, partially curing and drying the polyamic acid film in the gel state are obtained from the support, and the film in the gel state at 200-400 ° C. The polyimide film can be obtained by heating for 5 to 400 seconds.

In addition, in this invention, a polyimide film can also be manufactured from the obtained polyamic-acid solution as follows. That is, after imidating the obtained polyamic acid solution, the imidized solution is added to the second solvent, filtered and dried to obtain a solid content of the polyimide resin, and the obtained polyimide resin solid content is dissolved in the first solvent. It can obtain through a film forming process using a polyimide solution.

When imidating the said polyamic-acid solution, it can apply in combination with the thermal imidation method, the chemical imidation method, the thermal imidation method, and the compound imidation method similarly to the above-mentioned. Examples of specific imidization in the case of using the thermal imidization method and the chemical imidization method together include adding a dehydrating agent and an imidization catalyst to the obtained polyamic acid solution, and heating at 20 to 180 ° C. for 1 to 12 hours. Can be mad.

The first solvent may be the same solvent as the organic solvent used in the polymerization of the polyamic acid solution, the second solvent is solubility using a solvent that cannot dissolve the polyamic acid polymer obtained to obtain a solid content of the polyimide resin Among the solvents to which the principle of precipitation as a solid by tea is applicable, a polarity lower than that of the first solvent may be used. Specifically, the solvent may be one or more selected from water, alcohols, ethers, and ketones. At this time, the content of the second solvent is not particularly limited, but it is preferable to use 5 to 20 weight times the weight of the prepared polyamic acid solution.

The conditions of drying after filtering the obtained polyimide resin solid content are preferable to dry at a temperature of 50-150 degreeC for 2 to 24 hours considering the boiling point of the 2nd solvent and the 1st solvent which will remain in solidified resin.

After the film forming process, the polyimide solution in which the polyimide resin solids are dissolved is cast on a support, and the polyimide resin is heated at a temperature rising rate of 1 to 10 ° C./min in a temperature range of 40 to 400 ° C., and heated for 1 minute to 8 hours. Obtain a mid film.

The polyimide film thus prepared may have a lower yellowness, a higher whiteness, and an improved transmittance.

Although the thickness of the polyimide film obtained in this way is not specifically limited, It is preferable that it is the range of 10-250 micrometers, More preferably, it is 25-150 micrometers.

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

≪ Example 1 >

The reactor was filled with 20.02 g of N, N-dimethylacetaamide (DMAc) while passing nitrogen through a 100 ml 3-Neck round bottom flask equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a cooler. After lowering the temperature to 0 ° C., 2.0024 g (0.01 mol) of 4,4′-ODA was dissolved to maintain the solution at 0 ° C. To this was added 3.0026 g (0.01 mol) of H-BPDA (4,4'-tetracarboxylicdianhydride) and stirred for 1 hour to completely dissolve H-BPDA. At this time, the concentration of the solid was 20% by weight, after which the solution was left at room temperature and stirred for 8 hours.

After adding 3 equivalents of acetic anhydride (Acetic oxide; tritran) and pyridine (Priridine) as a chemical hardener to the polyamic acid solution, the polyamic acid solution was added at a rate of 10 ° C./min at 80 ° C. After heating for 10 hours while raising the temperature to imidize the polyamic acid solution, 30 g of the imidized solution was added to 300 g of water to precipitate, and the precipitated solid was finely powdered through filtration and grinding, followed by vacuum at 100 ° C. It dried in the drying oven for 6 hours and obtained about 8g of resin solid powder. The obtained resin solid was dissolved in 32 g of DMAc or DMF, which is a polymerization solvent, to obtain a 20 wt% polyimide solution. This was first dried for 2 hours while raising the temperature of 150 ° C. at a rate of 10 ° C./min, and then secondary drying for 2 hours while the temperature of 350 ° C. was raised at a rate of 10 ° C./min, and the thickness was 50 μm and 100. A polyimide film of μm was obtained.

<Example 2>

A polyimide film having a thickness of 50 μm and 100 μm was obtained in the same manner as in Example 1 except that 4,4′-ODA was replaced with p-PDA (p-Phenylenediamine) in Example 1.

<Example 3>

After filling N.N-dimethylacetaamide (DMAc) 18.372 in Example 1, the temperature of the reactor was lowered to 0 ° C. and 2.0024 g (0.01 mol) of 4,4′-ODA was dissolved to dissolve the solution at 0 ° C. Maintained. 1.0906 g (0.005 mol) of PMDA (pyromeliticdianhydride) was added thereto, followed by stirring for 1 hour, and then 1.50013 g (0.005 mol) of H-BPDA was added and stirred to dissolve completely. At this time, the concentration of the solid was 20% by weight, after which the solution was left at room temperature and stirred for 8 hours. Thereafter, a polyimide film having a thickness of 50 μm and 100 μm was obtained in the same manner as in Example 1.

<Example 4>

In Example 1, 4,4'-ODA was replaced with 2,2'-TFDB (2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl) except that the thickness was 50 in the same manner as in Example 1. Polyimide films of 100 μm and 100 μm were obtained.

Example 5

A polyimide film having a thickness of 50 μm and 100 μm was prepared in the same manner as in Example 1, except that 4,4′-ODA was replaced with a 1: 1 mixture of 2,2′-TFDB and p-PDA in Example 1. Got it.

<Example 6>

In Example 1, 1.0012 g (0.005 mol) of 4,4′-ODA was dissolved in 18.6164 g of N, N-dimethylacetaamide (DMAc), and the solution was maintained at 0 ° C. Subsequently, 0.7107 g (0.005 mol) of 1,4-BAC was added thereto, followed by stirring for 1 hour. Then, 2.9422 g (0.01 mol) of BPDA was added and stirred for 1 hour to completely dissolve BPDA. At this time, the concentration of the solid was 20% by weight, after which the solution was left at room temperature and stirred for 8 hours. Thereafter, a polyimide film having a thickness of 50 μm and 100 μm was obtained in the same manner as in Example 1.

<Example 7>

A polyimide film having a thickness of 50 μm and 100 μm was obtained in the same manner as in Example 1 except that BPDA was replaced with PMDA in Example 6.

<Example 8>

In Example 1, 2.0628 g (0.01 mol) of H-ODA (please write full name) was dissolved in 16.976 g of N, N-dimethylacetaamide (DMAc), and the solution was maintained at 0 ° C. PMDA 2.1812g (0.01mol) was added thereto and stirred for 1 hour to completely dissolve PMDA. At this time, the concentration of the solid was 20% by weight, after which the solution was left at room temperature and stirred for 8 hours. Thereafter, a polyimide film having a thickness of 50 μm and 100 μm was obtained in the same manner as in Example 1.

Comparative Example 1

In Example 1, 2.0024 g (0.01 mol) of 4,4'-ODA was dissolved in 19.7784 g of N, N-dimethylacetaamide (DMAc), and 2.9422 g (0.01 mol) of BPDA was added thereto, followed by stirring for 1 hour. BPDA was completely dissolved. At this time, the concentration of the solid was 20% by weight, after which the solution was left at room temperature and stirred for 8 hours.

After completion of the reaction, the obtained polyamic acid solution was cast to a thickness of 550㎛ ~ 1000㎛ using a doctor blade on a glass plate, and then dried in a vacuum oven for 1 hour at 40 ° C and 2 hours at 60 ° C to obtain a self standing film. A polyimide film having a thickness of 35 μm was obtained by heating at 80 ° C. for 3 hours at 100 ° C., 1 hour at 100 ° C., 1 hour at 200 ° C., and 30 minutes at 300 ° C. in a high temperature furnace oven.

Comparative Example 2

A polyimide film having a thickness of 35 μm was obtained in the same manner as in Comparative Example 1 except that 4,4′-ODA was brought into p-PDA in Comparative Example 1.

Comparative Example 3

In Example 1, 4,4′-ODA 2.0024 g (0.01 mol) was dissolved in 16.7344 g of N, N-dimethylacetaamide (DMAc), and 2.1812 g (0.01 mol) of PMDA was added thereto, followed by stirring for 1 hour. PMDA was completely dissolved. At this time, the concentration of the solid was 20% by weight, after which the solution was left at room temperature and stirred for 8 hours. Thereafter, a polyimide film having a thickness of 25 μm was obtained in the same manner as in Comparative Example 1.

In Comparative Examples 1 to 3, a thick film having a thickness of 50 μm or more was not well formed at the time of film forming, thereby preparing a film having a thickness of 25 to 35 μm.

The physical properties of the polyimide films prepared in Examples and Comparative Examples were measured as follows and are shown in Table 1 below.

(1) transmittance

The prepared film was measured for visible light transmittance using a UV spectrometer (Varian, Cary 100).

(2) color coordinates

division thickness
(Μm) Transmittance
500 nm Color coordinates
b Yellow road Tg
(℃) CTE
(ppm / ℃) Example One 50 80 19.8 18.6 275 22 100 79.5 20.4 20.8 275 22 2 50 84.6 10.4 9.2 290 15 100 81.7 11.1 11.5 290 15 3 50 67 29.4 28 310 29 100 64.1 30.2 29.8 310 29 4 50 86.8 15.6 16.2 265 30 100 83.1 16.1 18.4 265 30 5 50 83.2 16.4 17.1 280 33 100 81.5 17.9 19.3 280 33 6 50 75 23.8 22 262 21.5 100 71.2 24.2 24.7 262 21.5 7 50 72 25.7 20.1 272 27.3 100 66.7 27.2 23.9 272 27.3 8 50 68.5 28.1 27.1 294 20 100 62.3 29.5 29.4 294 20 Comparative example One 35 35 40 47.8 270 20 2 35 35 42 48 none 12 3 25 35 90.08 91.7 none 26

As a result of the physical property evaluation, in the case of Comparative Examples 1 to 3 as an example of the conventional polyimide film, the CTE exhibited excellent properties of 12 to 26, while exhibiting very poor yellowness and transmittance.

In contrast, the polyimide film of the present invention had a yellowness of 30 or less at a film thickness of 50 μm and 100 μm, a transmittance of 60% or more at 500 nm, and a color coordinate measurement b value of 30 or less, while showing a Tg of 260 ° C. Maintaining the above, the CTE also indicates that about 33 or less, it can be seen that the polyimide film of the present invention is significantly improved in color and light transmittance compared to the conventional polyimide.

Claims (7)

A unit structure derived from an aromatic dianhydride monomer to an aromatic diamine monomer and a unit structure derived from an alicyclic dianhydride monomer to an alicyclic diamine monomer;
A polyimide resin having a yellowness of 30 or less after forming a film having a thickness of 50 to 100 μm after forming a film having a thickness of 50 to 100 μm and a thickness of 30 or less. The polyimide resin according to claim 1, wherein after forming a film having a thickness of 50 to 100 μm, the light transmittance measured by a UV spectrometer is 60% or more in a light region having a wavelength of 500 nm. The polyimide resin according to claim 1, comprising 20 mol% or more of a unit structure derived from the alicyclic dianhydride monomer to the alicyclic diamine monomer. According to claim 1, wherein the alicyclic dianhydride monomer is 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dica Leboxic Anhydride (TDA), Bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, Cyclobutane-1,2,3,4-tetracarboxylic dianhydride Ride (CBDA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA) and 1,1'-bicyclohexane-3,3 ', 4,4'-tetracarboxylic diane Hydride (H-BPDA), 1,2,4,5-cyclohexane-tetracarboxylic dianhydride (H-PMDA), Bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic2, 3: 5,6-dianhydride (7CI, 8CI) is one or more selected from,
The alicyclic diamine monomers are 2,2-bis (3-amino-4-hydroxy cyclohexyl) hexafluoropropane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (MACM), 4,4 ' Methylenebicyclohexylamine (PACM), 1,3-bis (aminomethyl) cyclohexane (1,3-BAC), 1,4-bis (aminomethyl) cyclohexane (1,4-BAC), cis- 1,2-cyclohexanedimethanamine, trans-1,2-cyclohexanedimethanamine, bis (4-aminocyclohexyl) ether (H-ODA), N- (4-aminocyclohexyl) -1,4 At least one polyimide resin selected from cyclohexanediamine. The polyimide film containing the polyimide resin of any one of Claims 1-4. The polyimide alignment film containing the polyimide resin of any one of Claims 1-4. The board | substrate for polyimide display elements containing the polyimide resin of any one of Claims 1-4.