KR100491944B1 - Polyimide derivatives with pendant imide group and method for preparing them - Google Patents

Abstract

The present invention relates to a polyamic acid derivative for a liquid crystal alignment film having an imide ring-containing side chain group and a method for preparing the same, and more particularly to an aromatic having an acid dianhydride and an imide ring-containing side chain group containing an aliphatic ring acid dianhydride in an appropriate ratio or more. By solution-polymerizing aromatic diamines containing at least a proper ratio of diamine, the polyamic acid thus prepared has an imide ring as a side chain, and a polyimide resin having excellent mechanical properties such as heat resistance and surface strength properties, transparency, and vertical alignment of liquid crystals is obtained. It relates to a novel polyamic acid derivative that can be produced and a method for producing the same.

Description

Polyimide derivatives with pendant imide group and method for preparing them}

The present invention relates to a polyamic acid derivative for a liquid crystal alignment film having an imide ring-containing side chain group and a method for producing the same, and more particularly, to an acid dianhydride and an imide ring-containing side chain group containing an aliphatic ring acid dianhydride in an appropriate ratio or more. By solution-polymerizing aromatic diamines containing an aromatic diamine in an appropriate ratio or more, the polyamic acid thus prepared has an imide ring as a side chain, and thus the polyimide resin having excellent mechanical properties such as heat resistance and surface strength properties, transparency, and vertical alignment of liquid crystals. It relates to a novel polyamic acid derivative which can be prepared and a preparation method thereof.

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.

The polyimide resin may have various molecular structures according to the type of monomers used, and in general, aromatic tetracarboxylic acid components use pyromellitic dianhydride (PMDA) or nonphthalic anhydride (BPDA). As the diamine component, para-phenylenediamine ( p- PDA), meta-phenylenediamine ( m- PDA), 4,4-oxydianiline (ODA), 4,4-methylenedianiline (MDA), 2,2 -Bisaminophenylhexafluoropropane (HFDA), metabisaminophenoxydiphenylsulfone ( m- BAPS), parabisaminophenoxydiphenylsulfone ( p- BAPS), 1,4-bisaminophenoxybenzene (TPE -Q), 1,3-bisaminophenoxybenzene (TPE-R), 2,2-bisaminophenoxyphenylpropane (BAPP), 2,2-bisaminophenoxyphenylhexafuluropropane (HFBAPP) It manufactures by polycondensing using aromatic diamines, such as these.

Most polyimide resins are insoluble, fusible, ultra-high temperature resistant resins with the following characteristics:

(1) excellent thermal oxidation resistance, (2) high usable temperature, (3) excellent heat resistance indicating long term usable temperature of about 260 ° C and short term available temperature of about 480 ° C, (4) radiation resistance, (5 ) Excellent low temperature property, (6) Good chemical resistance.

However, although polyimide resins have the characteristics described above, they are very difficult to be applied to applications requiring transparency due to low light transmittance in the visible region due to the formation of charge transfer complexes. There are disadvantages. Accordingly, various kinds of main chain aliphatic polyimide resins have been prepared and applied to fields requiring excellent light transmittance such as liquid crystal alignment films. Polyimide resins for liquid crystal alignment films in which aliphatic ring groups have been introduced into the main chain have been used in which long alkyl chains are introduced as side chains for the expression of the pretilt angles, but the pretilt angles are not sufficient for use as vertical alignment liquid crystal alignment films. I have a problem.

Accordingly, the inventors of the present invention have tried to solve the above problems, as a result, 1,2,3,4-cyclobutane tetracarboxylic dianhydride (CBDA), 1,2,3,4 which is an aliphatic ring-based acid dianhydride -Cyclopentane tetracarboxylic dianhydride (CPDA), 5- (2,5-dioxotetrahydrofuryl) -3-methylcyclohexane-1,2-dicarboxylic dianhydride (DOCDA), 4- (2, 5-dioxotetrahydrofuryl-3-yl) -tetraline-1,2-dicarboxylic dianhydride (DOTDA), bicyclooctene-2,3,5,6-tetracarboxylic dianhydride (BODA) And mixtures of aromatic tetracarboxylic dianhydrides such as pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, oxydiphthalic dianhydride, nonphthalic dianhydride and hexafluoroisopropylidenediphthalic dianhydride and imide groups A novel structure of vertically oriented polyamic acids was prepared from aromatic diamines having side chain groups. It said, to those cured polyimide derivatives produced by that determine the excellent heat resistance, transparency, and represents the vertical alignment of the liquid crystal, thereby completing the present invention.

Accordingly, an object of the present invention is to provide a polyamic acid derivative for a vertical liquid crystal alignment film having an imide group-containing side chain group having excellent heat resistance, transparency and vertical alignment of liquid crystals.

The present invention is characterized by a polyamic acid derivative for a liquid crystal alignment film represented by the following formula (1).

here :

silver , , , , , , , , , And 1 type or 2 or more types of tetravalent groups chosen from these, Comprising: 1 or 2 or more types selected from (a), (b), (c), (d), and (e) must be included;

Is , , , , , , , , , , And

1 type, or 2 or more types of divalents selected from those necessarily containing (f);

n is a natural number ranging from 1 to 300, and m represents a natural number ranging from 1 to 30.

In addition, the present invention includes a monomer for producing a polyamic acid for liquid crystal alignment film represented by the following formula (2).

Here m represents a natural number in the range of 1 to 30.

Referring to the present invention in more detail as follows.

The polyamic acid derivative for a liquid crystal alignment film having an imide ring-containing side chain represented by Chemical Formula 1 according to the present invention is prepared by solution polymerization of a tetracarboxylic dianhydride monomer and a diamine monomer.

As the tetracarboxylic dianhydride monomer, 1,2,3,4-cyclobutane tetracarboxylic dianhydride [CBDA; (a)], 1,2,3,4-cyclopentane tetracarboxylic dianhydride [CPDA; (b)], 5- (2,5-dioxotetrahydrofuryl) -3-methylcyclohexane-1,2-dicarboxylic dianhydride [DOCDA; (c)], 4- (2,5-di Oxotetrahydrofuryl-3-yl) -tetraline-1,2-dicarboxylic dianhydride [DOTDA; (d)], and bicyclooctene-2,3,5,6-tetracarboxylic dianhydride [BODA; One or two or more aliphatic dianhydrides selected from (e)] are included as essential ingredients. At the same time, the polyamic acid derivative of the present invention may be selected from the group consisting of pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, oxydiphthalic dianhydride, nonphthalic dianhydride and hexafluoroisopropylidene diphthalic dianhydride. More than one aromatic tetracarboxylic dianhydride may be included.

As a diamine monomer, aromatic diamine which can introduce | transduce the substituent of said (f) is contained as an essential component, In addition, para-phenylenediamine ( p- PDA), meta-phenylenediamine ( m- PDA), 4, 4- jade Cydianiline (ODA), 4,4-methylenedianiline (MDA), 2,2-bisaminophenylhexafuluropropane (HFDA), metabisaminophenoxydiphenylsulfone ( m- BAPS), parabisaminophenoxy Sidiphenylsulfone ( p- BAPS), 1,4-bisaminophenoxybenzene (TPE-Q), 1,3-bisaminophenoxybenzene (TPE-R), 2,2-bisaminophenoxyphenylpropane ( BAPP), 2, 2-bisaminophenoxyphenylhexafuluropropane (HFBAPP), etc. can be used 1 type or 2 or more types of aromatic diamine.

That is, the present invention, in the preparation of a polyamic acid derivative, by using an aliphatic tetracarboxylic dianhydride represented by the above (a) to (e) as an appropriate ratio as a tetracarboxylic dianhydride monomer, mechanical properties and heat resistance is lowered A polyamic acid derivative having improved printability can be prepared with a minimum, and a polyamic acid having excellent heat resistance, light transmittance and vertical alignment of liquid crystals by containing as an essential component an aromatic diamine represented by the above (f) as a diamine monomer. Derivatives could be provided.

Thus, in the present invention, the aliphatic tetracarboxylic acid represented by the above (a) to (e) is used in the range of 10 to 90 mol% with respect to the total amount of the acid dianhydride, and the aromatic diamine represented by the above (f) is used as the total diamine It is characterized by using in the range of 3-99 mol% with respect to the usage-amount.

The polyamic acid derivative represented by Chemical Formula 1 according to the present invention prepared using the essential monomers as described above is a novel material that has not been prepared in the prior art, and has transparency and mechanical properties by introducing an imide group-containing side chain group. It is a novel polymer in which the electro-optical properties of liquid crystal cells produced by the application of these materials are particularly improved.

Such a polyamic acid derivative of the present invention has a weight average molecular weight (Mw) of about 10,000 to 150,000 g / mol, intrinsic viscosity range 0.3 to 1.5 dL / g, glass transition temperature range 230 to 400 ℃, imidization temperature range 200 to 300 ℃ , The pretilt angle has a characteristic in the range of 85 to 89.9 degrees. In addition, the polyamic acid derivatives according to the present invention include aprotic polar solvents such as dimethylacetamide (DMAc), dimethylformamide (DMF), N -methyl-2-pyrrolidone (NMP), acetone, and ethyl acetate. Easily dissolved at room temperature with respect to organic solvents such as meta-cresol. In particular, low solubility solvents such as tetrahydrofuran (THF), chloroform and low absorption solvents such as gamma-butyrolactone exhibit high solubility of 10% by weight or more at room temperature. Moreover, high solubility is shown also about these mixed solvents.

The polyamic acid derivative according to the present invention can be used as a core heat-resistant material of high-tech industries such as various electric, electronic, aerospace and aviation because it shows excellent solubility and liquid crystal alignment characteristics while maintaining the properties of the existing polyimide resin.

Such a present invention will be described in more detail based on the following examples, but the present invention is not limited thereto.

Example 1 Preparation of 1- (3,5-Dinitrophenyl) -3- (1-hexene) -succinicimide (DN-IM-6)

While slowly passing nitrogen gas through a 250 mL reactor equipped with a stirrer and a nitrogen injection device, 9.2 g (0.05 mole) of 3,5-dinitroaniline was dissolved in 50 mL of acetic acid as a reaction solvent, and then passed through nitrogen gas. 9.1 g (0.05 mole) of 2-hexen-1-yl succinic anhydride was added and refluxed for 24 h. After the reaction solution was cooled to room temperature, a precipitated solid was obtained. The obtained solid was recrystallized in methanol to prepare 12.7 g of 1- (3,5-dinitrofenyl) -3- (1-hexene) -succinicimide (DN-IM-6) (yield 73%) ).

Example 2: Preparation of 1- (3,5-Dinitrophenyl) -3- (1-octene) -succinicimide (DN-IM-8)

The reaction was carried out in the same manner as in Example 1, except that 10.5 g (0.05 mole) of 2-octen-1-yl succinic anhydride was used instead of 2-hexen-1-yl succinic anhydride. -Dinitrofenyl) -3- (1-octene) -succinimide (DN-IM-8) was obtained.

   The obtained solid was recrystallized in methanol to prepare 13.1 g of 1- (3,5-dinitrofenyl) -3- (1-octene) -succinicimide (DN-IM-8) (yield 70%). It was.

Example 3: Preparation of 1- (3,5-dinitrophenyl) -3- (1-decene) -succinicimide (DN-IM-10)

The reaction was carried out in the same manner as in Example 1, except that 11.9 g (0.05 mole) of 2-decen-1-yl succinic anhydride was used instead of 2-hexen-1-yl succinic anhydride 1- (3,5 -Dinitrofenyl) -3- (1-decene) -succinimide (DN-IM-10) was obtained.

   The obtained solid was recrystallized in methanol to prepare 14.5 g of 1- (3,5-dinitrofenyl) -3- (1-decene) -succinicimide (DN-IM-10) (yield 70%). It was.

Example 4: Preparation of 1- (3,5-dinitrophenyl) -3- (1-dodecene) -succinicimide (DN-IM-12)

The reaction was carried out in the same manner as in Example 1, except that 13.3 g (0.05 mole) of 2-dodecen-1-yl succinic anhydride was used instead of 2-hexen-1-yl succinic anhydride. 5-Dinitrofenyl) -3- (1-dodecene) -succinimide (DN-IM-12) was obtained.

   The obtained solid was recrystallized in methanol to give 14.0 g of 1- (3,5-dinitrofenyl) -3- (1-dodecene) -succinicimide (DN-IM-12) (yield 65%). Prepared.

Example 5 Preparation of 1- (3,5-Dinitrophenyl) -3- (1-tetradecene) -succinicimide (DN-IM-14)

Except for using 14.7 g (0.05 mole) of 2-tetradecen-1-yl succinic anhydride in place of 2-hexen-1-yl succinic anhydride was carried out in the same manner as in Example 1 except that 1- (3,5- Dinitrofenyl) -3- (1-tetradecene) -succinimide (DN-IM-14) was obtained.

   The obtained solid was recrystallized in methanol to give 14.9 g of 1- (3,5-dinitrofenyl) -3- (1-tetradecene) -succinicimide (DN-IM-14) (yield 65%). Prepared.

Example 6 Preparation of 1- (3,5-Dinitrophenyl) -3- (1-hexadecene) -succinicimide (DN-IM-16)

Except for using 16.1 g (0.05 mole) 2-hexadecen-1-yl succinic anhydride in place of 2-hexen-1-yl succinic anhydride was carried out in the same manner as in Example 1 except that 1- (3,5- Dinitrofenyl) -3- (1-hexadecene) -succinimide (DN-IM-16) was obtained.

   The obtained solid was recrystallized in methanol to give 15.4 g of 1- (3,5-dinitrofenyl) -3- (1-hexadecene) -succinicimide (DN-IM-16) (yield 63%). Prepared.

Example 7 Preparation of 1- (3,5-Dinitrophenyl) -3- (1-octadecene) -succinicimide (DN-IM-18)

Except for using 17.5 g (0.05 mole) 2-octadecen-1-yl succinic anhydride in place of 2-hexen-1-yl succinic anhydride was carried out in the same manner as in Example 1 except that 1- (3,5- Dinitrofenyl) -3- (1-octadecene) -succinicimide (DN-IM-18) was obtained.

   The obtained solid was recrystallized in methanol to give 16.2 g of 1- (3,5-dinitrofenyl) -3- (1-octadecene) -succinicimide (DN-IM-18) (yield 63%). Prepared.

Example 8 Preparation of 1- (3,5-Diaminophenyl) -3-hexyl-succinicimide (DA-IM-6)

After dissolving 6.9 g (0.02 mole) of DN-IM-6 in 100 mL of NMP and ethanol (1/3 volume ratio), Pd / C (5%) catalyst (metal palladium on the surface of the carbon particles in an amount of 5%) After applying the catalyst) 0.5 g with a hydrogen reactor, a reduction reaction was carried out at 60 ℃ for 2 hours. After filtering the reaction mixture, the reaction solvent was distilled under reduced pressure. Recrystallization in hexane / ethyl acetate cosolvent gave 3.18 g of 1- (3,5-diaminophenyl) -3-hexyl-succinicimide (DA-IM-6) (yield 55%).

Example 9: Preparation of 1- (3,5-diaminophenyl) -3-oxyl-succinicimide (DA-IM-8)

1- (3,5-diaminophenyl) -3-oxyl- in the same manner as in Example 8 except that 7.5 g (0.02 mole) of DN-IM-8 was used instead of DN-IM-6 Succinicimide (DA-IM-8) was obtained. Recrystallization in hexane / ethyl acetate cosolvent gave 3.68 g of 1- (3,5-diaminophenyl) -3-oxyl-succinicimide (DA-IM-8) (yield 58%).

Example 10 Preparation of 1- (3,5-diaminophenyl) -3-decyl-succinicimide (DA-IM-10)

1- (3,5-diaminophenyl) -3-decyl- in the same manner as in Example 8 except that 8.1 g (0.02 mole) of DN-IM-10 was used instead of DN-IM-6 Succinicimide (DA-IM-10) was obtained. Recrystallization in hexane / ethyl acetate cosolvent yielded 4.15 g of 1- (3,5-diaminophenyl) -3-decyl-succinicimide (DA-IM-10) (yield 60%).

Example 11 Preparation of 1- (3,5-Diaminophenyl) -3-dodecyl-succinicimide (DA-IM-12)

1- (3,5-diaminophenyl) -3-dodecyl in the same manner as in Example 8 except for using 8.6 g (0.02 mole) of DN-IM-12 instead of DN-IM-6 -Succinicimide (DA-IM-12) was obtained. Recrystallization in hexane / ethyl acetate cosolvent yielded 4.48 g of 1- (3,5-diaminophenyl) -3-dodecyl-succinicimide (DA-IM-12) (yield 60%).

Example 12 Preparation of 1- (3,5-diaminophenyl) -3-tetradecyl-succinicimide (DA-IM-14)

1- (3,5-diaminophenyl) -3-tetradecyl in the same manner as in Example 8 except for using 9.2 g (0.02 mole) of DN-IM-14 instead of DN-IM-6 -Succinicimide (DA-IM-14) was obtained. Recrystallization in hexane / ethyl acetate cosolvent gave 5.6 g of 1- (3,5-diaminophenyl) -3-tetradecyl-succinicimide (DA-IM-14) (yield 70%).

Example 13: Preparation of 1- (3,5-diaminophenyl) -3-hexadecyl-succinicimide (DA-IM-16)

1- (3,5-diaminophenyl) -3-hexadecyl in the same manner as in Example 8 except for using 9.8 g (0.02 mole) of DN-IM-16 instead of DN-IM-6 -Succinicimide (DA-IM-16) was obtained. Recrystallization in hexane / ethyl acetate cosolvent yielded 6.01 g of 1- (3,5-diaminophenyl) -3-oxyl-succinicimide (DA-IM-16) (yield 70%).

Example 14 Preparation of 1- (3,5-diaminophenyl) -3-octadecyl-succinicimide (DA-IM-18)

1- (3,5-diaminophenyl) -3-octadecyl in the same manner as in Example 8 except for using 10.3 g (0.02 mole) of DN-IM-18 instead of DN-IM-6 -Succinicimide (DA-IM-18) was obtained. 6.87 g of 1- (3,5-diaminophenyl) -3-octadecyl-succinimide (DA-IM-18) (yield 75%) was prepared by recrystallization in a hexane / ethyl acetate cosolvent.

As the diamine monomer having the imide ring-containing side chains prepared in Examples 8 to 14, DA-IM-6-18 was able to be produced with a yield of 50% or more after recrystallization, and relatively good storage stability in air. Indicated.

Example 15

Modified diamine with 17.8 g (0.09 mole) of methylene dianiline and an imide ring containing side chain while slowly passing nitrogen gas through a 50 mL reactor equipped with a stirrer, temperature controller, nitrogen injector, dropping funnel and cooler. g (0.01 mole) of DA-IM-16 was dissolved in reaction solvent N -methyl-2-pyrrolidone, and then passed through nitrogen gas to solid dioxotetrahydrofuryl-3-methylcyclohexane-1,2. -A mixture of 13.2 g (0.05 mole) dicarboxylic dianhydride and 10.9 g (0.05 mole) pyromellitic dianhydride was slowly added. At this time, the solid content (solid content) was fixed to 10% by weight, and stirred for 24 hours while maintaining the reaction temperature below 10 ℃ to obtain a polyamic acid solution (DPAA-1).

Example 16

Except for using 9.9 g (0.05 mole) and 21.48 g (0.05 mole) DA-IM-16 of methylene dianiline was carried out in the same manner as in Example 15 to obtain a polyamic acid resin (DPAA-2).

Example 17

A polyamic acid resin (DPAA-3) was obtained in the same manner as in Example 15 except that 1.98 g (0.01 mole) of methylene dianiline and 38.7 g (0.09 mole) of DA-IM-16 were used.

Example 18

9.8 g (0.05 mole) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was used instead of DOCDA, and NMP and γ-butyrolactone (5/5 by volume) were used as the reaction solvent. Except that was carried out in the same manner as in Example 15 to obtain a polyamic acid resin (CPAA-1).

Example 19

A polyamic acid resin (CPAA-2) was obtained in the same manner as in Example 16, except that 9.8 g (0.05 mole) of CBDA was used instead of DOCDA.

Example 20

A polyamic acid resin (CPAA-3) was obtained in the same manner as in Example 17, except that 9.8 g (0.05 mole) of CBDA was used instead of DOCDA.

Comparative Example 1

A polyamic acid solution (DPAA-0) was obtained in the same manner as in Example 15, except that 19.8 g (0.1 mole) of methylene dianiline was used as the diamine monomer.

Comparative Example 2

A polyamic acid solution (CPAA-0) was obtained in the same manner as in Example 18, except that 19.8 g (0.1 mole) of methylene dianiline was used as the diamine monomer.

Physical properties of the polyamic acid polymer prepared according to Examples 15 to 20 and Comparative Examples 1 and 2. Physical properties of the polyimide derivative thin film obtained by spin coating the prepared polyamic acid solution to a thickness of 0.05 to 0.2 μm on an ITO glass plate and then thermosetting at 230 ° C. for 30 minutes are shown in Table 1 below.

division Polyamic acid polymer Polyimide derivative Polyamic acid Intrinsic viscosity ^*) (dL / g) Polyimide Glass transition temperature (℃) Surface tension (dyne / cm) Pencil hardness Example 15   DPAA-1 0.94  DPI-1  331   45 4H Example 16   DPAA-2 0.72  DPI-2  318   43 3H Example 17   DPAA-3 0.85  DPI-3  305   39 3H Example 18   CPAA-1 0.92  CPI-1  270   34 5H Example 19   CPAA-2 0.87  CPI-2  265   32 4H Example 20   CPAA-3 0.91  CPI-3  260   30 4H Comparative Example 1   DPAA-0 1.15  DPI-0  330    50 B Comparative Example 2   CPAA-0 1.30  CPI-0  275   41 HB ^*) Measured at 30 ° C. at a concentration of 0.5 g / dL using NMP as a solvent.

As shown in Table 1, the polyamic acid derivative solutions according to the present invention are all bright amber transparent resin, it was confirmed to have an intrinsic viscosity of 0.3 to 1.5 dL / g, film formation and mechanical properties by the solvent template This appeared to be very excellent.

In addition, as shown in Table 1, the pencil hardness of the polyimide thin film prepared from the polyamic acid derivatives according to the present invention in which the imide ring-containing ring-based side chain group was introduced is about H ~ 5H, Comparative Example 1 Compared with the polyimide of 2 and 2, the surface hardness was significantly improved. The surface tension of the polyimide thin film showed a tendency to decrease as the content of the monomer into which the imide ring-containing ring-based side chain was introduced increased. Examples 18 to 20 using CBDA as a monomer showed Example 15 using DOCDA. Values lower than 18 were shown.

In addition, the polyamic acid solutions according to the present invention obtained in Examples 15 to 20 were diluted with gamma-butyrolactone to maintain the solution viscosity at room temperature of 20 to 40 cp, followed by thin film coating (coating condition; 400 ~ 4,000 rpm, 25 seconds), the characteristics of the produced liquid crystal cell are shown in Table 2, respectively. The alignment state of the liquid crystal was visually observed using a polarizing microscope, and the pretilt angles of the liquid crystal cells were measured using a crystal rotation method.

division Alignment film Pretilt angle (°) VHR (%) (room temperature) Example 15 DPI-1 89.0 98 Example 16 DPI-2 89.8 98 Example 17 DPI-3 89.9 98 Example 18 CPI-1 88.0 99 Example 19 CPI-2 88.0 99 Example 20 CPI-3 89.5 99 Comparative Example 1 DPI-0 2.0 98 Comparative Example 2 CPI-0 2.5 99

As shown in Table 2, the liquid crystal cell prepared using the polyamic acid derivative according to the present invention showed very excellent liquid crystal orientation and time stability. The pretilt angle was about 85 to 89.9 °, which was larger than that of Comparative Examples 1 and 2, and showed a tendency to increase with increasing flexibility of the polymer main chain. That is, it was confirmed that the polyimide resins of Examples 15 to 20 exhibited vertical alignment characteristics, and the voltage holding ratios were all 98% or more, and were suitable for use as liquid crystal alignment films for vertical alignment TFT-TN and STN LCD. .

As described above, a novel vertically oriented liquid crystal alignment film has been produced by the present invention, which has not only excellent heat resistance and mechanical properties but also excellent light transmittance and high pretilt angle, and these require TFT- which requires difficult electro-optic properties. It has been found to be useful as a liquid crystal alignment film for TN and STN LCDs and various advanced heat-resistant structural materials.

In the present invention described above in detail only for the embodiments described, it will be apparent to those skilled in the art that various modifications and changes are possible within the technical spirit of the present invention, and such modifications and modifications belong to the appended claims.

1 is a ¹ H-NMR spectrum of 1- (3,5-diaminophenyl) -3-dodecyl-succinicimide (DA-IM-12) prepared according to Example 11 of the present invention.

2 is a ¹ H-NMR spectrum of DPAA-1 prepared according to Example 15 of the present invention.

3 is a DSC curve of DPI-1 prepared according to Example 15 of the present invention.

4 is a ¹ H-NMR spectrum of CPAA-1 prepared according to Example 18 of the present invention.

Claims (8)

A polyamic acid derivative for a liquid crystal alignment film, which is represented by the following Chemical Formula 1; [Formula 1] In Formula 1 above: silver , , , , , , , , , And 1 type or 2 or more types of tetravalent groups chosen from these, Comprising: 1 or 2 or more types selected from (a), (b), (c), (d), and (e) must be included; Is , , , , , , , , , , And 1 type, or 2 or more types of divalents selected from those necessarily containing (f); n is a natural number ranging from 1 to 300 and m is a natural number ranging from 1 to 30. The polyamic acid derivative for liquid crystal alignment film according to claim 1, wherein the intrinsic viscosity of the polyamic acid derivative represented by Chemical Formula 1 is in the range of 0.3 to 1.5 dL / g. The polyamic acid derivative for liquid crystal alignment film according to claim 1, wherein the polyamic acid derivative represented by Chemical Formula 1 has a molecular weight ranging from 10,000 to 150,000 g / mol. The polyamic acid derivative for liquid crystal alignment film according to claim 1, wherein the glass transition temperature of the polyamic acid derivative represented by Chemical Formula 1 is in the range of 230 to 400 ° C. The polyamic acid derivative for a liquid crystal alignment film according to claim 1, wherein the pretilt angle of the polyamic acid derivative represented by Chemical Formula 1 is in a range of 85 to 89.9 degrees. The method of claim 1, wherein the polyamic acid derivative represented by Formula 1 is dimethylacetamide, dimethylformamide, N -methyl-2-pyrrolidone, tetrahydrofuran, chloroform, acetone, ethyl acetate and gamma-butyrolactone A polyamic acid derivative for a liquid crystal alignment film, characterized in that it has dissolution characteristics with respect to a solvent selected from among them. The polyamic acid derivative for a liquid crystal alignment film according to claim 1, wherein the imidation temperature range of the polyamic acid derivative represented by Chemical Formula 1 is 200 to 300 ° C. A monomer for producing a polyamic acid for liquid crystal alignment film, characterized in that represented by the following formula (2). [Formula 2] Here m represents a natural number in the range of 1 to 30.