KR100383869B1 - Polyimide resin - Google Patents

Abstract

The present invention relates to a novel polyimide resin, more specifically, dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride, 1 selected from the diamine group represented by the following formula (1) It relates to a polyimide resin prepared by reacting at least one diamine and at least one diamine selected from the group of diamines represented by the formula (2) to prepare a polyamic acid and imidize the same, and according to the present invention, printability, light transmittance and A new form of polyimide resin excellent in liquid crystal orientation can be provided.

[Formula 1]

[Formula 2]

Wherein X is a hydrogen atom, or R and R 'are each a hydrogen atom, an aliphatic or aromatic hydrocarbon having 1 to 18 carbon atoms, -O ₂ CR, -CO ₂ R, -NRR', -CONRR ', -NCOR, -OCO _{It is} 2R, -OR, or -R, R <_1> is a C6-C18 hydrocarbon, n and m are the integers of 1-16, respectively.

Description

Polyimide Resin

The present invention relates to a novel polyimide resin that can be used as a liquid crystal alignment film, and more particularly, to a new type of polyimide resin having excellent printability, light transmittance and liquid crystal alignment property, prepared by containing a new type of functional diamine monomer. will be.

In general, the polyimide resin refers to a high heat-resistant resin prepared by condensation polymerization of an aromatic tetracarboxylic acid or a derivative thereof with an aromatic diamine or an aromatic diisocyanate followed by imidization. Such polyimide resins may have various molecular structures depending on the type of monomer used. Generally, aromatic tetracarboxylic acid components include pyrometllitic dianhydride (PMDA), benzophenon tetracarboxylic dianhydride (BTDA) or biphthalic anhydride (BPDA), and aromatic diamine components are ODA (oxydianiline) or p-PDA (p-phenylene diamine) ) To polymerize to prepare a polyamic acid resin and to cure it to form a polyimide resin, which may be represented by the following Scheme 1.

The polyimide resin as described above is an insoluble, insoluble ultra high heat resistant resin, which has (1) excellent heat oxidation resistance, and (2) long service temperature is about 260 ℃, and short service temperature is about 480 ℃. It not only possesses heat resistance, but also has (3) excellent electrochemical and mechanical properties, (4) excellent radiation resistance, (5) low temperature, (6) intrinsic flame retardancy and (7) good chemical resistance. Due to these advantages, it is used in a wide range of fields such as automotive materials, aviation materials, spacecraft materials, and electronic materials, and recently, it is also used in display materials such as optical fibers and liquid crystal alignment films.

Due to these characteristics, polyimide resins have been applied to many applications in the electronic materials sector such as high rigidity, heat resistant structural materials, buffer buffers for semiconductors, and liquid crystal alignment films. The liquid crystal alignment film is a key material of the TFT-LCD driving, and serves to align the liquid crystal which serves as an optical shutter of the backlight during image realization. In order to be applied to the liquid crystal alignment layer, properties such as high strength, thermal stability, high printability, high transmittance, low temperature curing property, and liquid crystal alignment property are required, but general polyimide resins need to be compensated for because of poor permeability, low temperature curing property, and liquid crystal alignment property. In the case of permeability and low temperature curing, it has been controlled to the range that can be used by introduction of aliphatic monomers, and functional monomers having long alkyl groups have been used to obtain liquid crystal alignment enough to be used as liquid crystal alignment films, but the number of 1,3-diaminophenyl groups It was limited to a compound having a variety of applications was impossible.

The present invention solves the problems of the prior art as described above, to provide a polyimide resin excellent in printability, light transmittance and liquid crystal orientation using a novel functional diamine monomer that can improve the properties of the polyimide resin. .

That is, the present invention is dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride, at least one diamine selected from the diamine group represented by the following formula (1), and the diamine group represented by the formula (2) It relates to a polyimide resin prepared by reacting at least one diamine selected from to prepare a polyamic acid and imidize it.

Wherein X is a hydrogen atom, or R and R 'are each a hydrogen atom, an aliphatic or aromatic hydrocarbon having 1 to 18 carbon atoms, -O ₂ CR, -CO ₂ R, -NRR', -CONRR ', -NCOR, -OCO _{It is} 2R, -OR, or -R, R <_1> is a C6-C18 hydrocarbon, n and m are the integers of 1-16, respectively.

The polyimide resin of the present invention is selected from the dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride represented by the following formula (3) and the diamine group represented by the formula (2) in the structural formula It is characterized by including necessarily diamine or more of species.

The polyimide resin of the present invention is represented by formula (2) and at least one diamine selected from dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride and the diamine group represented by the formula (1). A mixture of one or more diamines selected from the diamine group is added in a solvent so that the content of tetracarboxylic dianhydride and diamine monomer in the total reaction solution is 2-40 wt%, and then 10-48 at 0-40 캜. By reaction for a time, a polyamic acid is obtained which is obtained by imidization.

In this case, in addition to the dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride, one or more tetracarboxylic dianhydride selected from the group represented by the following Formula 4 may be further included.

The organic solvent used in the polyamic acid polymerization is not particularly limited as long as it can dissolve the unique diamine component of the present invention and does not interfere with the reaction. N-methyl-2-pyrrolidone (NMP), N, N-dimethyl form Amide (DMF), N, N-dimethyl acetamide (DMAc), dimethyl sulfoxide (DMSO), and the like can be used. In addition, THF, chloroform and the like can be used as a solvent. Among the solvents that can be used, NMP, DMAc, and DMF are preferable because they catalyze the polymerization reaction during the polymerization of the polyamic acid and promote imidization in the subsequent imidization process.

Specifically, the imidization of the polyamic acid is performed by heating at 100 to 120 ° C. using a heating plate or an oven, gradually increasing the temperature in an oven under a nitrogen atmosphere, and heating the temperature to a temperature range of 250 to 350 ° C. for about 30 minutes to 2 hours. Can be done.

Polyimide resin of the present invention prepared by the above method has a structure as shown in the following formula (5).

In the above formula May be one or more structures selected from dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride and / or a structure represented by Formula 4, May be one or more structures selected from the structures represented by Formulas 1 and 2.

Polyimide resin according to the present invention has a weight average molecular weight (Mw) of about 2,000 ~ 150,000g / mole and maintains the intrinsic viscosity in the range of 0.2 ~ 1.5dL / g, and has a glass transition temperature of 230 ~ 350 ℃. In addition, the polyimide resin of the present invention is easily dissolved at room temperature with respect to organic solvents such as m-cresol, including polar solvents such as DMAc, DMF, and NMP. In addition, it exhibits high solubility of 10% by weight or more at room temperature for tetrahydrofuran (hereinafter referred to as THF), low boiling point solution such as chloroform, and low hygroscopic solvent such as γ-butyrolactone. Moreover, high solubility is shown also about these mixed solvents.

Although the present invention will be described in more detail with reference to the following examples, the following examples are for the purpose of explanation and are not intended to limit the present invention.

Preparation Example 1 : Preparation of diamine compound using 4-nitrophthalic anhydride and dodecanoic acid 1,1'-di (aminomethyl) methyl ester

Dissolve 27.2 g (0.1 mole) of dodecanoic acid 1,1'-di (aminomethyl) methyl ester in 150 ml of dimethylacetamide as a reaction solvent while slowly passing nitrogen gas through a 500 ml reactor equipped with a stirrer and a nitrogen injection device. 42.5 g (0.22 mole) of solid nitrophthalic anhydride was added over 30 minutes while passing through nitrogen gas. After the reaction was completed, the reaction mixture was precipitated in excess distilled water, and the filtered solid was bicarbonate. After washing several times with an aqueous sodium solution and diluted aqueous hydrochloric acid solution, the dinitro compound was prepared by drying under reduced pressure at a temperature of 60 ℃. At this time, the reaction yield was 97%.

The dinitro compound (10 g) prepared above was dissolved in 200 ml of ethanol, and then placed in a hydrogen reactor with 1.5 g of Pd / C (5%), followed by a reduction reaction at 40 ° C. for 3 hours. After completion of the reaction, the reaction mixture was filtered using Celite, and the reaction solvent was distilled under reduced pressure. After recrystallization in an ethyl acetate / hexane (1: 1) co-solvent to give a diamine compound of formula 6 having a molecular weight of 598 in 83.4% yield.

Wherein X is -O (CH ₂ ) ₁₁ CH ₃ .

Preparation Example 2 : Preparation of diamine compound using 4-nitrophthalic anhydride having an imide ring and dodecanoic acid (1,1'-di (aminomethyl) methyl ester

27.2 g (0.1 mole) of dodecanoic acid 2- (1,3-diaminopropyl) ester was dissolved in 150 ml of dimethylacetamide as a reaction solvent while slowly passing nitrogen gas through a 500 ml reactor equipped with a stirrer and a nitrogen injection device. After passing through nitrogen gas, 38.6 g (0.2 mole) of solid 4-nitrophthalic anhydride was added over 30 minutes. After reacting for another 2 hours, 0.3 mole of acetic anhydride was added thereto. After 3 minutes, pyridine 0.5mole was added and the reaction temperature was raised to 100 ° C. for 3 hours. After the reaction was completed, the reaction mixture was precipitated in excess distilled water, and the filtered solid was washed several times with an aqueous sodium bicarbonate solution and a diluted hydrochloric acid solution, and then dried under reduced pressure at a temperature of 60 ° C. to prepare a dinitro compound. At this time, the reaction yield was 78%.

The dinitro compound (10 g) prepared above was dissolved in 200 ml of ethanol, and then placed in a hydrogen reactor with 1.5 g of Pd / C (5%), followed by a reduction reaction at 40 ° C. for 3 hours. After completion of the reaction, the reaction mixture was filtered using Celite, and the reaction solvent was distilled under reduced pressure. After recrystallization in ethyl acetate / hexane (1: 1) cosolvent to obtain a diamine compound of formula 7 having a molecular weight of 562 in 58.5% yield.

Wherein X is -O (CH ₂ ) ₁₁ CH ₃ .

Preparation Example 3 Preparation of Diamine Compound Using 4-nitrobenzoic Acid and Dodecanoic Acid 1,1′-di (aminomethyl) methyl Ester

27.2 g (0.1 mole) of dodecanoic acid 2- (1,3-diaminopropyl) ester and 25 g (0.25 mole) of triethylamine were added while slowly passing nitrogen gas through a 500 ml reactor equipped with a stirrer and a nitrogen injection device. After dissolving in 150 ml of dimethylacetamide as a reaction solvent, 40.6 g of nitrobenzoic chloride (0.22 mole) dissolved in 50 ml of dimethylacetamide while passing through nitrogen gas was added over 30 minutes. After the reaction was completed, the reaction mixture was precipitated in excess distilled water, and the filtered solid was washed several times with an aqueous sodium bicarbonate solution and a diluted hydrochloric acid solution, and then dried under reduced pressure at a temperature of 60 ° C. to prepare a dinitro compound. The reaction yield was 85%.

The dinitro compound (10 g) prepared above was dissolved in 200 ml of ethanol, and then placed in a hydrogen reactor with 1.5 g of Pd / C (5%), followed by a reduction reaction at 40 ° C. for 3 hours. After completion of the reaction, the reaction mixture was filtered using Celite, and the reaction solvent was distilled under reduced pressure. After recrystallization in an ethyl acetate / hexane (1: 1) cosolvent to obtain a diamine compound of formula 8 having a molecular weight of 508 in 78.2% yield.

Wherein X is -O (CH ₂ ) ₁₁ CH ₃ .

Preparation Example 4 Preparation of Diamine Compound Using 4-nitrobenzoic Acid and Dodecanoic Acid 1,1′-di (hydroxymethyl) methyl Ester

11.8 g (0.1 mole) of 1,6-hexanediol and 25 g (0.25 mole) of triethylamine were dissolved in 150 ml of dimethylacetamide as a reaction solvent while slowly passing nitrogen gas through a 500 ml reactor equipped with a stirrer and a nitrogen injection device. Thereafter, 40.6 g of nitrobenzoic chloride (0.22 mole) dissolved in 50 ml of dimethylacetamide was added over 30 minutes while passing through nitrogen gas. After the reaction was completed, the reaction mixture was precipitated in excess distilled water, and the filtered solid was washed several times with an aqueous sodium bicarbonate solution and a diluted hydrochloric acid solution, and then dried under reduced pressure at a temperature of 60 ° C. to prepare a dinitro compound. At this time, the reaction yield was 83%.

The dinitro compound (10 g) prepared above was dissolved in 200 ml of ethanol, and then placed in a hydrogen reactor with 1.5 g of Pd / C (5%), followed by a reduction reaction at 40 ° C. for 3 hours. After completion of the reaction, the reaction mixture was filtered using Celite, and the reaction solvent was distilled under reduced pressure. After recrystallization in ethyl acetate / hexane (1: 1) cosolvent to obtain a diamine compound of formula 9 having a molecular weight of 506 in 77.2% yield.

Wherein X is -O (CH ₂ ) ₁₁ CH ₃ .

Preparation Example 5 Preparation of Diamine Compound Using 4,4'-Diaminobenzene and 5-dodecoxyisophthalic Acid

While slowly passing nitrogen gas through a 500 ml reactor equipped with a stirrer and a nitrogen injection device, 35 g (0.1 mole) of 5-dodecoxyisophthalic acid was dissolved in 150 ml of N-methylpyrrolidinone as a reaction solvent, followed by nitrogen gas. While passing through, 10.8 g (0.2 mole) of solid 4,4'-diaminobenzene was added over 5 minutes, and then 30 g of xylene was added to raise the temperature to 180 ° C and react for 4 hours to completely remove the produced water. . After removing the solvent from the reaction mixture and recrystallized in hexane-ethyl acetate solvent to dry under reduced pressure at a temperature of 60 ℃ to prepare a dinitro compound. At this time, the reaction yield was 48%.

The dinitro compound (10 g) prepared above was dissolved in 200 ml of ethanol, and then placed in a hydrogen reactor with 1.5 g of Pd / C (5%), followed by reduction for 3 hours at 40 ° C. After completion of the reaction, the reaction mixture was filtered using Celite, and the reaction solvent was distilled under reduced pressure. After recrystallization in ethyl acetate / hexane (1: 1) co-solvent to obtain a diamine compound of formula 10 having a molecular weight of 430 in 48% yield.

Wherein X is -O (CH ₂ ) ₁₁ CH ₃ .

Preparation Example 6

P-PDA (9.72 g, 0.09 mole) and modified diamine of Preparation Example 1 (5.98 g, 0.01) while slowly passing nitrogen gas through a 500 mL reactor equipped with a stirrer, a temperature controller, a nitrogen injection device, a dropping funnel and a cooler. 26.4 g of dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride (hereinafter referred to as DOCDA) in solid form while dissolving mole) in a reaction solvent NMP (169.5 ml) and passing nitrogen gas. (0.1 mole) was added slowly. At this time, the solid content concentration was fixed at 20% by weight and the reaction was performed at 25 ° C for 10 hours. After the reaction was completed, a new polyamic acid resin (hereinafter referred to as PA-1) was synthesized by adding a solvent in a desired composition. The yield of polymerization was quantitative.

Preparation Example 7

p-PDA (9.72 g, 0.09 mole), modified diamine (5.62 g, 0.01 mole) and DOCDA (26.4 g, 0.1 mole) according to Preparation Example 2 were dissolved in NMP (168.1 ml), and In the same manner, a new polyamic acid resin (hereinafter referred to as PA-2) was synthesized.

Preparation Example 8

p-PDA (9.72 g, 0.09 mole), modified diamine (5.08 g, 0.01 mole) according to Preparation Example 3 and DOCDA (26.4 g, 0.1 mole) were dissolved in NMP (164.8 ml), and then Preparation Example 6 and In the same manner, a new polyamic acid resin (hereinafter referred to as PA-3) was synthesized.

Preparation Example 9

p-PDA (9.72 g, 0.09 mole), modified diamine (3.56 g, 0.01 mole) and DOCDA (26.4 g, 0.1 mole) according to Preparation Example 4 were dissolved in NMP (158.7 ml), and In the same manner, a polyamic acid resin (hereinafter referred to as PA-4) was synthesized.

Preparation Example 10

p-PDA (9.72g, 0.09mole), modified diamine (4.3g 0.01mole) according to Preparation Example 5 and DOCDA (26.4g, 0.1mole) was dissolved in NMP (158.7 ml), the same as in Preparation Example 6 Polyamic acid resin (hereinafter referred to as PA-5) was synthesized by the method.

Comparative Production Example 1

P-PDA (9.72 g, 0.09 mole) and modified diamine DA-L-4M (2.07 g, 0.01) while slowly passing nitrogen gas through a 50 mL reactor equipped with a stirrer, temperature controller, nitrogen injector, dropping funnel and cooler. After dissolving mole) in the reaction solvent methacresol, a solid DOCDA (26.4 g, 0.1 mole) was slowly added while passing through nitrogen gas. At this time, the solid content concentration (solid content) was fixed to 15% by weight and the reaction temperature was raised to 70 ℃ and then the reaction was carried out for 2 hours. The temperature was then raised to reflux and stirred for 6-12 hours. At this time, isoquinoline (1-5 weight percent) was used as the imidization catalyst. After the reaction was completed, the reaction mixture was precipitated in excess methanol using a waring blender, the filtered polymer was washed several times with water and methanol, and then dried under reduced pressure at a temperature of 120 ° C to form a polyimide resin. (Hereinafter referred to as PI-1) were synthesized. The yield of polymerization was quantitative. The intrinsic viscosity measured at 30 ° C at a concentration of 0.5 g / dL using methacresol as a solvent was 1.31 dL / g.

Comparative Production Example 2

P-PDA (9.72g, 0.09mole) and modified diamine DAP-12 (2.72g, 0.01mole) while slowly passing nitrogen gas through 500mL reactor equipped with stirrer, temperature controller, nitrogen injector, dropping funnel and cooler Was dissolved in reaction solvent NMP (157.8 ml) and slowly added DOCDA (26.4 g, 0.1 mole) as a solid while passing through nitrogen gas. At this time, the solid content (solid content) was fixed at 20% by weight and the reaction temperature was carried out for 10 hours at 25 ℃. After the reaction was completed, a new polyamic acid resin (hereinafter referred to as PA-6) was synthesized by adding a solvent with a desired composition. The yield of polymerization was quantitative.

Example 1 Properties of Polyimide Resin

Characteristics of the polyamic acid and polyimide resin prepared in Preparation Examples 6 to 10 and Comparative Examples 1 and 2 were measured, and the properties such as glass transition temperature are shown in Table 1 below.

Used resin Intrinsic viscosity Glass transition temperature Film properties Hardening rate Preparation Example 6 PA-1 0.71 265 Chewy 94% Preparation Example 7 PA-2 1.00 265 Chewy 98% Preparation Example 8 PA-3 0.91 248 Chewy 98% Preparation Example 9 PA-4 0.73 240 Chewy 98% Preparation Example 10 PA-5 0.52 258 Chewy 99% Comparative Production Example 1 PI-1 1.31 330 Chewy 100% Comparative Production Example 2 PA-6 0.97 255 Chewy 93%

[Measurement of physical properties]

Intrinsic viscosity: The polyamic acid resin or the polyimide resin was dissolved at a concentration of 0.5 g / dL using NMP as a solvent, and measured at 30 ° C.

* Glass transition temperature: Measured using a differential scanning calorimeter (differential scanning calorimeter).

* Curing rate: The polyimide resin was applied to a thickness of 2 micrometers, and then cured for 180 ° C./10 minutes on a hot plate, and then the curing rate was measured using IR (Infrared Spectroscopy).

Example 2 :

The polyamic acids of Preparation Examples 6 to 10 and Comparative Preparation Examples 1 and 2 were applied to a glass substrate with a transparent electrode by spin coating, and then baked at 180 ° C. for 1 hour to form a coating film having a thickness of about 700 mm 3. After rubbing the formed coating surface with a rubbing machine, and observing whether or not peeling after rubbing under a microscope, the two substrates were bonded by a gap of 5㎛, the liquid crystal (Mark ZLI-5081) is injected to prepare a TN liquid crystal cell It was. The orientation characteristic was observed using this, and the result is shown in Table 2.

Pretilt VHR Contrast Preparation Example 6 3.4 97.5 242 Preparation Example 7 3.3 99.5 291 Preparation Example 8 4.6 98.8 278 Preparation Example 9 4.4 99.1 292 Preparation Example 10 4.4 99.0 314 Comparative Production Example 1 2.3 96.9 198 Comparative Production Example 2 4.1 97.3 221

Example 3 Measurement of Printing Properties

The polyamic acid resins of Preparation Examples 6 to 10 and Comparative Preparation Examples 1 and 2 were diluted to 5% by weight with a general organic solvent, printed using a roll coater, heated on a hot plate, and then coated. Was observed. As shown in Table 3, the polyimide resins of the present invention have excellent film uniformity and significantly reduce the occurrence of pinholes, compared to conventional resins.

Membrane uniformity Pin Holes (pcs / ㎠) Preparation Example 6 Great 0 Preparation Example 7 Great 0 Preparation Example 8 Great 0 Preparation Example 9 Great 0 Preparation Example 10 Great 0 Comparative Production Example 1 Bad 100 Comparative Production Example 2 usually 20

When manufacturing a liquid crystal aligning film using the polyimide resin by this invention, the liquid crystal aligning film excellent in printability, light transmittance, and liquid crystal orientation can be provided.

Claims (3)

1 selected from dioxytetrahydrofuran-3-methylcyclohexane-1,2-dicarboxylic dianhydride, at least one diamine selected from the diamine group represented by the following formula (1), and the diamine group represented by the formula (2) A polyimide resin prepared by reacting more than one diamine to produce a polyamic acid and imidating it. [Formula 1] [Formula 2] Wherein X is a hydrogen atom, or R and R 'are each a hydrogen atom, an aliphatic or aromatic hydrocarbon having 1 to 18 carbon atoms, -O ₂ CR, -CO ₂ R, -NRR', -CONRR ', -NCOR, -OCO _{It is} 2R, -OR, or -R, R <_1> is a C6-C18 hydrocarbon, n and m are the integers of 1-16, respectively. The polyimide resin according to claim 1, further comprising at least one tetracarboxylic dianhydride selected from the group of tetracarboxylic dianhydrides represented by the following formula (4) when preparing the polyimide resin. [Formula 4] The intrinsic viscosity measured at 30 ° C., dissolved in NMP solvent at a concentration of 0.5 g / dL, is 0.5-1.5 dL / g, the glass transition temperature is 230-350 ° C., and the pretilt angle is 1-15 °. Polyimide resin, characterized in that.