KR102251519B1 - Polyamic acid, And Polyimide Resin And Polyimide Film - Google Patents

Abstract

The present invention is a polymerization product of dianhydride and diamine, and (i) 2-bis[3-(3,4-dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA) is used as dianhydride. Including; (Ii) Trans(equatorial)4-amino-(1,1bicyclohexyl)4-amine (T-BCA) as diamine; Or (iii) 2-bis[3-(3,4-dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA) as dianhydride and Trans(equatorial)4-amino-(1) as diamine ,1bicyclohexyl)4-amine (T-BCA); It relates to a polyamic acid characterized in that it is any one of, and further relates to a polyimide resin and a polyimide film, which are imidized products thereof.

Description

Polyamic acid, polyimide resin and polyimide film {Polyamic acid, And Polyimide Resin And Polyimide Film}

The present invention relates to a polyamic acid, a polyimide resin prepared therefrom, and a colorless transparent polyimide film.

In general, a polyimide (PI) film is a film of a polyimide resin, and a polyimide resin is a solution polymerization of an aromatic dianhydride and an aromatic diamine or an aromatic diisocyanate to prepare a polyamic acid derivative, followed by ring closure dehydration at high temperature. It refers to a high heat-resistant resin prepared by imidization. Aromatic dianhydrides used to prepare polyimide resins include pyromellitic dianhydride (PMDA) or biphenyltetracarboxylic dianhydride (BPDA), and aromatic diamines include oxydianiline (ODA), p -Phenylene diamine (p-PDA), m-phenylene diamine (m-PDA), methylenedianiline (MDA), bisaminophenylhexafluoropropane (HFDA), and the like are typical.

Polyimide resin is an ultra-high heat-resistant resin that is insoluble and insoluble, and has excellent properties such as heat oxidation resistance, heat resistance, radiation resistance, low temperature characteristics, and chemical resistance.It is heat-resistant high-tech materials and insulating coatings such as automobile materials, aviation materials, and spacecraft materials. , Insulating films, semiconductors, TFT-LCD electrode protective films, etc. are used in a wide range of fields. Recently, display materials such as optical fibers or liquid crystal alignment films, and films containing conductive fillers or coated on the surface are also used for transparent electrode films.

However, the polyimide film is colored brown or yellow due to its high aromatic ring density, so it has a low transmittance in the visible light region and a yellowish color, making it difficult to use as an optical member due to its low light transmittance or high birefringence. have. In order to solve this problem, a method of polymerizing by purifying a monomer and a solvent with high purity was attempted, but the improvement in transmittance was not significant.

U.S. Patent No. 5053480 describes a method of using an aliphatic cyclic dianhydride component instead of an aromatic dianhydride. Compared to the purification method, transparency and color were improved when in solution or film, but the transmittance was also improved. The high transmittance was not satisfactory due to the limitation of the product, and also showed a result of deteriorating thermal and mechanical properties. In particular, in the case of a polyimide film with improved yellow color, the Tg (glass transition temperature) value was lowered, making it difficult to use in a field requiring a high temperature of 300°C or higher.

On the other hand, U.S. Patent Nos. 4595548, 463061, 4645824, 4895972, 5218083, 503453, 5218077, 5367046, 5338826. Nos. 5986036, 6232428 and Korean Patent Laid-Open Publication No. 2003-0009437 discloses _{a monomer having a curved structure connected to a linking group such as -O-, -SO 2} -, CH ₂ -and to the m-position rather than the p-position, or -There have been reports of producing a polyimide of a novel structure with improved transmittance and color transparency in the limit that thermal properties are not significantly deteriorated by using an aromatic dianhydride dianhydride having a substituent such as _{CF 3 and an aromatic diamine monomer.} Mechanical properties, yellowness and visible light transmittance showed insufficient results to be used as a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, and a base layer for a flexible display.

Accordingly, an object of the present invention is to provide a polyimide film that is colorless and transparent, has a relatively low birefringence, and has excellent heat resistance and mechanical properties.

Accordingly, a first preferred embodiment of the present invention for solving the above problem is a polymerization reaction product of dianhydride and diamine, (i) 2-bis[3-(3,4-) represented by the following formula (1) as dianhydride. Dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA); (Ii) Diamine containing Trans(equatorial)4-amino-(1,1bicyclohexyl)4-amine (T-BCA) represented by the following formula (2); Or (iii) 2-bis[3-(3,4-dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA) and diamine represented by the following formula (1) as a dianhydride by the following formula (2). Trans(equatorial)4-amino-(1,1bicyclohexyl)4-amine (T-BCA) as indicated; It is a polyamic acid characterized in that it is any one of.

<Formula 1>

<Formula 2>

At this time, when the compound represented by Formula 1 is included as dianhydride, its content is 10 to 100 mol% relative to the total moles of dianhydride, and when the compound represented by Formula 2 is included as a diamine, the content is total moles of diamine. It may be a standard 10 to 100 mol%.

The polyamic acid according to the first embodiment is a dianhydride containing the compound represented by Formula 1, and the diamine is bis trifluoromethylbenzidine (TFDB), oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), cyclohexanediamine (13CHD, 14CHD), bis aminohydroxy phenyl hexafluoropropane ( DBOH), bis aminophenoxy benzene (133APB, 134APB, 144APB), bis aminophenyl hexafluoro propane (33-6F, 44-6F), bis aminophenylsulfone (4DDS, 3DDS), bis amino phenoxy phenyl hexafluoro It may be one or more selected from the group consisting of roperophan (4BDAF), bis amino phenoxy phenylpropane (6HMDA) and bis aminophenoxy diphenyl sulfone (DBSDA).

Or it includes a compound represented by Formula 2 as a diamine, and the dianhydride is 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), cyclobutanetetracarboxylic Dianhydride (CBDA), biphenyltetracarboxylic dianhydride (BPDA), bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTA) ), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (TDA), pyromellitic acid Dianhydride (1,2,4,5-benzene tetracarboxylic dianhydride (PMDA), benzophenone tetracarboxylic dianhydride (BTDA), biscarboxyphenyl dimethyl silane dianhydride (SiDA), oxy Diphthalic dianhydride (ODPA), bis dicarboxyphenoxy diphenyl sulfide dianhydride (BDSDA), sulfonyl diphthalic anhydride (SO ₂ DPA) and isopropylidene diphenoxy bis phthalic anhydride ( 6HDBA) may be one or more selected from the group consisting of.

In addition, the second and third preferred embodiments of the present invention are a polyimide resin, which is an imide product of the polyamic acid of the first embodiment, and a polyimide film prepared by imidizing the polyamic acid.

In particular, the polyimide film according to the third embodiment may have a yellowness of 5 or less based on a film thickness of 10 to 50 μm, and an average light transmittance of 88% or more measured at 550 nm, and TE (transeverse Elictric)-TM ( Birefringence (Δn) defined as transverse magnetic) may be 0.01 or less.

Further, a fourth preferred embodiment of the present invention is an image display device including the polyimide film of the third embodiment.

After film formation, the polyimide resin and film according to the present invention are colorless and transparent and have low birefringence, so that they can be usefully used as a substrate or electronic material for a display.

The present invention is a polymerization product of dianhydride and diamine,

(I) a dianhydride containing 2-bis[3-(3,4-dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA) represented by the following formula (1);

(Ii) Diamine containing Trans(equatorial)4-amino-(1,1bicyclohexyl)4-amine (T-BCA) represented by the following formula (2); or

(Iii) 2-bis[3-(3,4-dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA) represented by the following formula 1 as a dianhydride and a diamine represented by the following formula 2 Trans(equatorial)4-amino-(1,1bicyclohexyl)4-amine (T-BCA) to be included;

It can provide a polyamic acid characterized in that any one of.

<Formula 1>

<Formula 2>

In the present invention, 2-bis[3-(3,4-dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA) represented by 1 in the above chemistry is linked to a -0- group, and the length of the monomer is Since it is long and _{has a substituent of -CF 3} -, it is possible to impart excellent mechanical properties as well as flexibility while improving transmittance and color transparency.

In addition, Trans (equatorial) 4-amino- (1,1 bicyclohexyl) 4-amine (4-amino- (1,1 bicyclohexyl) -4-amine, T-BCA) represented by Formula 2 is generally a substituent Depending on the position of the cis type and the trans type, and can be divided into axial and equatorial according to the binding direction.In the present invention, in particular, in the present invention, trans (equatorial) 4-amino-( By using 1,1 bicyclohexyl)-4-amine, the molecular weight is easy to increase, and as a result, a film can be easily formed, but due to the nature of the compound, the length is short and has an alicyclic structure, so it is colorless, transparent, and excellent heat resistance can be imparted. have.

In the present invention, 2-bis[3-(3,4-dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA) represented by Formula 1 is dianhydride in its content when it is included as dianhydride. It is 10 to 100 mol% based on the total mole of ride, and the content of Trans(equatorial)4-amino-(1,1bicyclohexyl)4-amine (T-BCA) represented by Chemical Formula 2 is diamine when it is included as a diamine. It may be 10 to 100 mol% based on the total mole. At this time, in the case of the former, if the BPFDA is less than 10 mol% of the total moles of dianhydride, mechanical properties (elongation at break) cannot be improved, and in the latter case, if the T-BCA is less than 10 mol% of the total moles of diamine, the color And improvement in transmittance may not be achieved.

In addition, in the present invention, the BPFDA and T-BCA are each independently included as a dianhydride or a diamine, but may be used at the same time, and when used at the same time, color and birefringence properties are improved, and heat resistance can be improved. There is this. However, when used at the same time, there may be some possibility of lowering the glass transition temperature.

On the other hand, when the polyamic acid of the present invention contains BPFDA as a dianhydride, the diamine is bis trifluoromethylbenzidine (TFDB), oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylene. Diamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), cyclohexanediamine (13CHD, 14CHD), bis aminohydroxy phenyl hexafluoropropane (DBOH), bis aminophenoxy benzene (133APB, 134APB, 144APB), bis aminophenyl hexafluoro propane (33-6F, 44-6F), bis aminophenylsulfone (4DDS, 3DDS), bis amino phenoxy phenyl hexafluoropropane (4BDAF), bis amino It may be one or more selected from the group consisting of phenoxy phenylpropane (6HMDA) and bis aminophenoxy diphenyl sulfone (DBSDA), and when T-BCA is included as a diamine, dianhydride is 2,2-bis(3 ,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), cyclobutanetetracarboxylic dianhydride (CBDA), biphenyltetracarboxylic dianhydride (BPDA), bicyclo[2.2.2 ]Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTA), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3, 4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (TDA), pyromellitic acid dianhydride (1,2,4,5-benzene tetracarboxylic dianhydride (PMDA), benzophenone Tetracarboxylic dianhydride (BTDA), biscarboxyphenyl dimethyl silane dianhydride (SiDA), oxydiphthalic dianhydride (ODPA), bis dicarboxyphenoxy diphenyl sulfide dianhydride (BDSDA), sulfonyl It may be one or more selected from the group consisting of diphthalic anhydride (SO _{2 DPA) and isopropylidene diphenoxy bisphthalic anhydride (6HDBA).}

The solvent (polymerization solvent) for the polymerization reaction of the dianhydride and diamine is not particularly limited as long as it dissolves the polyamic acid. As a known reaction solvent, selected from m-cresol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), acetone, and diethylacetate. One or more polar solvents are used. In addition, a low-boiling solution such as tetrahydrofuran (THF) or chloroform, or a low-absorption solvent such as γ-butyrolactone may be used. In addition, a low-boiling solution such as tetrahydrofuran (THF) or chloroform, or a low-absorption solvent such as γ-butyrolactone may be used.

The content of the solvent is not particularly limited, but in order to obtain an appropriate molecular weight and viscosity of the polyamic acid solution, the content of the polymerization solvent (first solvent) is preferably 50 to 95% by weight of the total polyamic acid solution, and more preferably It is more preferably 70 to 90% by weight.

According to the present invention, the polyamic acid obtained by polymerizing the monomer can be appropriately selected and imidized by a known imidation method, and examples thereof include a thermal imidation method, a chemical imidation method, a thermal imidation method, and It can be applied in combination with a chemical imidization method.

The chemical imidization method is a method in which a dehydrating agent typified by acid anhydrides such as acetic anhydride and an imidization catalyst typified by tertiary amines such as isoquinoline, β-picoline, and pyridine are added to the polyamic acid. The chemical method is a method in which polyamic acid is gradually heated in a temperature range of 40 to 300°C and heated for 1 to 8 hours. In addition, the thermal imidization method may be used in combination with the chemical imidization method, and the heating condition may vary depending on the type of the polyamic acid solution, the thickness of the film, and the like.

In the present invention, a composite imidization method in which a thermal imidation method and a chemical imidization method are used in combination may be applied as an example of preparing a polyamic acid. In more detail, a dehydrating agent and an imidation catalyst are added to the polyamic acid solution, cast on a support, and heated at 80 to 200°C, preferably 100 to 180°C to activate the dehydrating agent and the imidation catalyst, and partially After curing and drying, a polyimide film can be obtained by heating at 200 to 400° C. for 5 to 400 seconds.

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

The first solvent may be the same solvent as the solvent used in the polymerization of the polyamic acid solution, and the second solvent may be used with a polarity lower than that of the first solvent in order to obtain a solid content of the polyamic acid resin, specifically water, It may be one or more selected from alcohols, ethers and ketones. At this time, the content of the second solvent is not particularly limited, but it is preferably 5 to 20 times the weight of the polyamic acid solution.

The film applied to the support is gelled on the support by dry air and heat treatment. The gelling temperature condition of the applied film is preferably 100 to 250°C, and a glass plate, aluminum foil, circulating stainless steel belt, stainless drum, etc. may be used as a support. The treatment time required for gelation depends on the temperature, the type of the support, the amount of the applied polyamic acid solution, and the mixing conditions of the catalyst, and is not limited to a certain time, but it can be carried out in the range of preferably 5 to 30 minutes. have.

The gelled film is heat-treated away from the support to complete drying and imidization, and the temperature during the heat treatment is preferably between 100 and 500°C, and the treatment time is preferably between 1 and 30 minutes. It is preferable that the heat-treated film is heat-treated under a certain tension to remove the residual stress in the film generated in the film formation, and by solving the thermal history and residual stress, more stable thermal properties can be obtained. In particular, if the last heat treatment is not performed, since the residual stress to be contracted in the film reduces thermal expansion, the value of the thermal expansion coefficient may be significantly lowered. At this time, since the tension and temperature conditions are correlated with each other, the tension conditions may vary depending on the temperature, but the temperature is preferably 300 to 500°C, the heat treatment time is preferably 1 minute to 3 hours, and the remaining film after the heat treatment The volatile component may be 5% or less, preferably 3% or less.

The thickness of the polyimide film thus obtained is not particularly limited, but it is preferably in the range of 10 to 250 µm, more preferably 10 to 100 µm.

The polyimide film according to the present invention may have a yellowness of 5 or less based on a film thickness of 10 to 50 µm, and an average light transmittance of 88% or more measured at 550 nm, and a transeverse lic (TE)-TM (transverse magnetic) Birefringence (Δn) defined as is 0.01 or less, and may be used as a display substrate or an electronic material. Accordingly, the present invention can provide an image display device including a polyimide film exhibiting the above-described characteristics.

Example

Hereinafter, the present invention will be described in more detail through examples. These examples are only for describing the present invention in more detail, and the present invention is not limited thereto.

Example One

As a reactor, a 500ml reactor equipped with a stirrer, nitrogen injection device, dropping funnel, temperature controller, and cooler was charged with 341.514 g of N-methyl-2-pyrrolidone (NMP) while passing nitrogen, and then 28.821 g (0.09 mol) of TFDB was added. Dissolved. BPFDA 56.558 g (0.09 mol) was added thereto and reacted for 18 hours to obtain a polyamic acid solution having a solid content of 20 wt% and a viscosity of 134 poise.

After the reaction was completed, the obtained solution was applied to a stainless steel plate, cast and dried with hot air at 80°C for 30 minutes, 150°C for 30 minutes, 250°C for 30 minutes, and 300°C for 30 minutes, and then cooled slowly. Separated from the sea plate, a polyimide film having a thickness of 30 μm was prepared.

Example 2

As a reactor, 307.478 g of N-methyl-2-pyrrolidone (NMP) was charged while passing nitrogen through a 500 ml reactor equipped with a stirrer, nitrogen injection device, dropping funnel, temperature controller, and cooler, and then 23.56 g (0.12 mol) of T-BCA. ) Was dissolved. After maintaining the temperature of the reactor at 80° C., 53.31 g (0.12 mol) of 6FDA was added thereto and reacted for 1 hour, and then lowered to 25° C. After the reaction for 18 hours, a polyamic acid solution having a solid content of 20% by weight and a viscosity of 256 poise was obtained.

Thereafter, a polyimide film was prepared in the same manner as in Example 1.

< Measurement example >

(1) Measurement of transmittance: The transmittance was measured three times at 550 nm using a UV spectrometer (Cotica Minolta CM-3700d), and the average value is shown in Table 1.

(2) Viscosity: A Brookfield viscometer (RVDV-II+P) was measured twice at 50 rpm using 6 scandals at 25°C to measure the average value.

(3) Yellowness (Y.I.) Measurement: Using a UV spectrometer (Konita Minolta, CM-3700d), the yellowness was measured according to ASTM E313 standard.

(4) Birefringence measurement: Using a birefringence analyzer (Prism Coupler, Sairon SPA4000), the average value was measured by measuring three times each in TE (Transeverse Elictric) mode and TM (Transverse magnetic) mode at 532 nm, and (TE mode)-(TM Mode) was reflected as a birefringence value.

division ingredient Molar ratio Film thickness
(㎛) 550nm transmittance
(%) Y.I. Prism Coupler TE
(transverse electric)
mode TM
(transverse magnetic)
mode Birefringence Example 1 TFDB/BPFDA 100:100 30 88.65 3.86 1.5953 1.5898 0.0055 Example 2 T-BCA/6FDA 100:100 25 88.25 4.5 1.5507 1.549 0.0017

The results of Table 1 show that the embodiment according to the present invention has excellent birefringence and, in particular, has excellent transmittance and yellowness for use as an optical material.

Claims (9)

It is a polymerization product of dianhydride and diamine,
(I) Trans(equatorial)4-amino-(1,1bicyclohexyl)4-amine (T-BCA) represented by the following formula (2) as diamine; or
(Ii) 2,2`-bis[3-(3,4-dicarboxyphenoxy)phenyl]hexafluoroisopropane dianhydride (BPFDA) represented by the following Formula 1 as a dianhydride and the following formula as a diamine Trans(equatorial)4-amino-(1,1bicyclohexyl)4-amine (T-BCA) represented by 2; Polyamic acid, characterized in that any one of.
<Formula 1>

<Formula 2>

The method of claim 1, wherein when the compound represented by Formula 1 is included as dianhydride, the content is 10 to 100 mol% based on the total mol of dianhydride,
Polyamic acid, characterized in that when the compound represented by Formula 2 is included as a diamine, the content is 10 to 100 mol% based on the total mol of diamine.
delete The method of claim 1, wherein the polyamic acid includes a compound represented by Formula 2 as a diamine,
Dianhydride is 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), cyclobutanetetracarboxylic dianhydride (CBDA), biphenyltetracarboxylic dianhydride Ride (BPDA), bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTA), 4-(2,5-dioxotetrahydrofuran- 3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (TDA), pyromellitic acid dianhydride (1,2,4,5-benzene tetracar) Boxylic dianhydride (PMDA), benzophenone tetracarboxylic dianhydride (BTDA), biscarboxyphenyl dimethyl silane dianhydride (SiDA), oxydiphthalic dianhydride (ODPA), bisdicarboxyphenoxydi Polya, characterized in that it is at least one selected from the group consisting of phenyl sulfide dianhydride (BDSDA), sulfonyl diphthalic anhydride (SO _{2 DPA) and isopropylidene diphenoxy bisphthalic anhydride (6HDBA)} Micsan.
A polyimide resin which is an imidized product of the polyamic acid according to any one of claims 1, 2, and 4.
A polyimide film produced by imidizing the polyamic acid according to any one of claims 1, 2 and 4.
The polyimide film of claim 6, wherein the polyimide film has a yellowness of 5 or less based on a film thickness of 10 to 50 μm, and an average light transmittance of 88% or more measured at 550 nm.
The polyimide film according to claim 6, wherein the polyimide film has a birefringence (Δn) of 0.01 or less, which is defined as transeverse lictric (TE)-TM (transverse magnetic).
An image display device comprising the polyimide film of claim 6.