TWI343412B - - Google Patents

Description

1343412 (1) Field of the Invention The present invention relates to a liquid crystal alignment agent for obtaining a liquid crystal alignment film, and more particularly, to obtain a pretilt angle (pret丨11 ang丨e) ), and a liquid crystal alignment agent for a liquid crystal alignment film excellent in liquid crystal alignment. [Prior Art] In recent years, liquid crystal display elements have been actively developed due to their excellent display characteristics, and display performance is further improved. With the subsequent demand for liquid crystal alignment films, it is also necessary to enhance various characteristics. The general characteristics required for the liquid crystal alignment film include, for example, controlling the pretilt angle 'voltage holding ratio' of the liquid crystal molecules and the charge accumulation characteristics of the direct current voltage. However, among these characteristics, the pretilt angle is controlled to uniformly drive the liquid crystal display. A very important feature of components. Nowadays, a general liquid crystal alignment film uses a polymer such as a polyimide or a polyimide precursor, and the characteristics of the liquid crystal alignment film are greatly affected by the polymer structure. The liquid crystal pretilt angle ' obtained by such a polymer-based liquid crystal alignment film is generally about 1 to 2 degrees, but it is known that a higher pretilt angle can be obtained when an appropriate branch is introduced into the polymer. As a branch having an effect of improving the liquid crystal pretilt angle, it is known that an alkyl group having a carbon number of 4 to 20 or a fluorinated alkyl group (for example, refer to JP-A-2-282 "7 2 6) has a benzene ring Or a cyclic group such as a cyclohexane ring or a cyclic group such as an alkyl group (for example, refer to JP-A-3-37 3 3 3) and a group having a steroid skeleton (for example, refer to JP-A-4-28) No. -5 (2) (2) 1343412), etc. The above method is designed to separate the pretilt angle controlled by the branch and other properties obtained from the polymer backbone, and in addition, to change the structure of the branch or The introduction amount is advantageous in that the pretilt angle 任意 can be arbitrarily changed. However, the introduction of such a branch-chain disorder is caused by a liquid crystal alignment element of a polymer main chain, and the liquid crystal display element produced by the liquid crystal display element may have a problem of lowering the liquid crystal alignment property. The disorder causing the alignment of the liquid crystal 'is easily lowered by the heating. The reliability of the liquid crystal display element is greatly reduced due to a decrease in the pretilt angle of heating. Such a decrease in liquid crystal alignment is remarkable when the rubbing treatment conditions are weak. The rubbing treatment of the liquid crystal alignment film is an important step for specifying the alignment direction of the liquid crystal, but there is a problem that display defects occur due to dust generated at this time. In order to suppress the occurrence of this dust, the rubbing treatment conditions tend to be weaker and weaker in recent years. Further, the liquid crystal alignment film which is usually subjected to the rubbing treatment is washed with ultrapure water or the like in order to remove the adhered dust. However, in order to improve the cleaning efficiency, an organic solvent such as isopropyl alcohol is also used. A liquid crystal alignment film having a weak liquid crystal alignment property causes a disorder of liquid crystal alignment or a decrease in pretilt angle even in accordance with such an organic solvent. As described above, the introduction of the pretilt occurs because the polymer-branched liquid crystal alignment film system easily controls the pretilt angle, but relatively has a problem of lowering the liquid crystal alignment. Especially for weak rubbing or organic solvent washing, it will be difficult to impart good liquid crystal alignment and stable pretilt angle. [Claim of the Invention] -6 - (4) (4) 1343412 A branched polymer having a repeating unit of polyamine (ρ 〇 1 ya ni icacid) represented by the following general formula (5), or The polyaminic acid is dehydrated and closed to the polyimine.

(In the formula, A represents a tetravalent organic group, and B represents a divalent organic group.) 5. The liquid crystal alignment agent according to the above 4, which is repeated for the repeating unit represented by the general formula (5) One of the structures has a structure represented by the following formula (6)

(wherein Y1 represents a tetravalent organic group, k represents an integer of 4 to 6). ό A liquid crystal alignment agent according to the above 4 or 5, which is a repeating unit represented by the general formula ($) One of the repeated structures has a structure represented by the following formula (7).

(In the formula, '2彳糸 indicates an organic group of 4 valence' Υ3 indicates a trivalent (5) 1343412 organic group, X represents a single bond or a divalent bond group, and R is a species. a fluorinated alkyl group having from 4 to 20 carbon atoms and having 20 carbon atoms, having one to three benzene rings or cyclohexanes, and a group having a steroid skeleton 7. The liquid crystal alignment agent according to the above 4 or 6, wherein the repeating structure is represented by a general structure, wherein the structure of the formula (6) η is 20 to 95%, (7) The structure indicated is 5%. 8. The liquid crystal alignment agent according to any one of the above 5 to 7, wherein Υ1 or Υ2 of the formula (7) is a group of at least 4 to I represented by the following (8) or (9) (5) ί means to 30 (6: structure

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The liquid crystal alignment of the present invention contains a solution of a polymer for forming a liquid crystal alignment film, which has an alkylene group having 4 to 16 carbon atoms in the main chain J and has a branch for increasing the liquid crystal pretilt angle. The polymer of the chain can obtain a liquid crystal alignment film with a pre-tilt angle of 5 and stable. Here, the polymer has a carbon number of 4 to 16 based on the main chain, and has a continuous 4 to 16 methylene group in the polymer main chain. The hydrogen on this continuous methylene group may be methyl or ethyl. Further, the branching system for increasing the pretilt angle of the liquid crystal indicates that the liquid crystal pretilt angle is increased by the substitution branch (6) (6) 1334112 which is introduced into the poly-alkylene. The branch in the polymer may be a species or a plurality of species. The branch which increases the pretilt angle of the liquid crystal may, for example, be an alkyl group having 4 to 20 carbon atoms, a fluorinated alkyl group having 4 to 2 carbon atoms, or 1 to 3 benzene rings or cyclohexanes. a group of an alkane ring, a group having a steroid skeleton, and the like. Among them, the 'alkyl group and the fluorinated alkyl group are preferably from 8 to 20 carbon atoms. The carbon number is preferably from 12 to 20, more preferably from 16 to 18 carbon atoms. A group having 1 to 3 benzene rings or a cyclohexane ring or a group having a steroid skeleton is preferably a carbon having a carbon number of from -16 to 16 in addition to the cyclic structures. It is especially preferred that the number of atoms is 4 to 8 alkyl groups. These branched organic groups may be bonded directly to the polymer backbone or may be bonded via a divalent linkage. Examples of the bonding group include a group in which an ether, an ester 'melamine, an imido group, a complex such a group and an alkylene group having 1 to 3 carbon atoms, or 1 to 3 carbon atoms. Alkyl and the like. The branch system containing these bond groups is represented by the following formula (1). —XR (1) (wherein X represents a single bond or a divalent bond group, and R represents at least one selected from the group consisting of an alkyl group having 4 to 20 carbon atoms and a carbon number of 4 to 20) a fluorinated alkyl group, an organic group having a group of benzene rings or a cyclohexane ring of [up to 3], and a group having a steroid skeleton. The branch represented by the above formula (1) Specific examples are suitable as shown in the following formula (2) or (3). -10- (7) 1343412 -X1-R1 (7) (wherein, X) represents a single bond of any one, and R] represents an alkyl group having 8 to 20 carbon atoms—X2-R2—X3- R3 (wherein X2 represents any one of a single bond '-0' 'CH2' and -CH2〇-, R2 means (4), X3 means a single bond, -〇-, and a C00 - R3 system An alkyl group having 1 to 16 carbon atoms - and -C00 0 ) (3) a C00-, - any one of the following formulas'

(4b)

(4c) (4) oo (4d) Particularly suitable in the above formula (2) is the above formula -0-, R1 is an alkane having 12 to 18 carbon atoms; a particularly suitable example in the formula (3) X2 is any one of them, R2 is the above 4b, X3 is a single bond, and R3 is a 12-membered alkyl group. In the present invention, as a liquid crystal alignment film for forming a polybenzazole, a polyaminic acid, a polyimine, a polyamidamine, a polyether, a polyetheretherketone, a polyester, a polyphenylene carbonate polybenzoate Imidazole, polybenzoxazole 'polyester quinone imine and aryl ARAMID) and the like. Among them, polyphosphoric acid or polyimide is particularly preferred because it is a liquid crystal alignment film. -11 - (2) X] is . Further, the above 0- and -ch2o atoms are 4 to a compound, and examples thereof include an imine, a polyurea', a polysulfide, and a fragrant polyamine. (The reliability is excellent (8) 1343412 has a carbon number of 4 To 6 alkylene groups, and a high liquid crystal pretilt branched branched polyamic acid can be obtained by reacting a diamine component dianhydride component. Specifically, (a) is used as one of the above components. a diamine having a carbon number of 4 to an alkylene group in the main skeleton, as the above-mentioned tetracarboxylic acid dianhydride component, b) having a branched tetracarboxylic acid dianhydride having a liquid crystal pretilt angle as the above diamine component One is a method of using a diamine having a branching liquid of an increasing liquid as the above-mentioned tetracarboxylic acid dianhydride component for an alkanoic acid dianhydride having 4 to 16 carbon atoms on the main skeleton, (c) Among the above diamine components, a diamine having a dialkyl group having 4 to 16 carbon atoms on a truss to increase the pre-tilt angle of the liquid crystal, and (d) a component of the upper diacid anhydride倂 used for tetracarboxylic dianhydrides having 6 carbon atoms in the main skeleton, and having Four branched _ a method of liquid acid anhydride. This polyaminic acid has a repeating unit represented by the following general formula (5), which has a combination with a tetracarboxylic acid diamine: 16 methods, (crystal pretilt angle -, The tetracarboxylic acid is used for the main bone 'and the pretilt angle of 4 to crystal with the tetracarboxylic acid can be expressed as lysine.

(In the formula, A represents a tetravalent organic group, and B represents a mechanical group.) In the above polylysine, a diamine compound having 4 to 16 alkylene groups on the main skeleton is used. It is preferred that the diamine compound having a branched chain which increases the pretilt angle of the liquid crystal is preferably a divalent carbon atom. -12 - (9) 1343412 The outer polyalkylene group having an alkylene group having 4 to 6 carbon atoms and having a branching angle for increasing the liquid crystal pretilt angle in the main chain is closed to the above polyamine water. Get it. The diamine compound having an alkylene group having 4 to 16 carbon atoms in the main bone may, for example, be 4-bis(4-monoaminophenoxy) or -bis(4-aminophenoxy). Pentane, 1^-bis(4-aminooxy)hexane, I,7-bis(4-aminophenoxy)heptane,],8 (4-aminophenoxy)octane, 1 , 9-bis(4-monoaminophenoxyalkane, anthracene, 10-bis(4-aminophenoxy)decane, M1_bis(4-phenoxy)undecane,],]2- Bis(4-aminophenoxy)deca,], 13-bis(4-aminophenoxy)tridecane, iota, 14-bis(4 basic oxy)tetradecane, 1,15 - Bis(4-monoaminophenoxy)decene and ],]6-bis(4-monoaminophenoxy)hexadecane, etc. Further, the aliphatic diamine may, for example, be a 4-diamine group. Butane, I, 5-diamine,], 6-diaminohexane, 7-diaminoheptane, 8-diamine, 1,9-diaminodecane, i , 〇-diamino decane,], 6_di-2,5-dimethyl hexane, L7-diamino 2,5-dimethylheptene U-diamine — 4,4 Dimethyl heptane, ι 7-diamino-3_heptane, 1,9-diamino-5-methylindole, 2,n-diamino-dodecyl M2-diaminooctadecane, and 1:2~ hospital. Among the polylysines obtained by using such a diamine compound as a raw material, the polyamic acid having a structure represented by the following formula in the main chain is such a polyaminic acid type, and the above aromatic diamine compound can be used. Further, it is preferred to have a butyrylbenzene bis(1) oxime monoamine-icir-A7T:-amine pentadecane as the amylpentylaminoalkane 'methyldialkyl). -Aminopropoxy ft -13- (10) (10)1343412

(wherein Y1 represents a tetravalent organic group, and k represents an integer of 4 to 16), that is, in the repeating unit represented by the general formula (5), as one of the repeated unit structures, the above The polylysine of the structure represented by the formula (6) or the polyimine which dehydrates the polyamine is preferably used. In the above, since the liquid crystal alignment property and the pretilt angle are excellent in heat resistance when used as a liquid crystal alignment film, a polymer of 1·. 5 -bis(4-aminophenoxy)pentane is used, that is, k of the formula (6) It is especially suitable for 5 o'clock. A diamine compound having a branched chain for increasing the pretilt angle of the liquid crystal is bonded to a diamine main skeleton having two first-order amine groups, and a branched diamine which enhances the liquid crystal pretilt angle described above is bonded. The branch of the diamine may, for example, be a structure of the above formula (I), and as a suitable branch, for example, those represented by the above formula (2) or (3). With regard to the formula (2), it is particularly preferable that the XI is -0-, and the R] is an alkyl group having 12 to 18 carbon atoms. Further, with respect to the formula (3), X2 is any of -0 - and -CH20-, R2 is the above 4b, X3 is a single bond, and R3 is an alkyl group having 4 to 2 carbon atoms. The structure of the diamine main skeleton is not particularly limited, but from the viewpoint of improving the pretilt efficiency, diaminobenzene, diaminobiphenyl 'diaminodiphenyl ether, diaminodiphenyl group Methane, and diaminodiphenylamine are preferably -14(11)(11)1343412', of which a diaminobenzene skeleton is preferred. Suitable specific examples of the diamine compound as described above include, for example, 4-(dodecylhydroxy)-indole, 3-diaminobenzene, 4-monohexadecyl group-1, 3-2. Aminobenzene, 4-mono(octadecylhydroxy)~1,3-diaminobenzene'4-[4-(4-heptylcyclohexyl)phenoxy]-1,3-diaminobenzene, And 5 - {[4-(4-heptylcyclohexyl)phenoxy]methylhydrazine_], 3-diaminobenzene, and the like. The diamine compounds as the pretilt angle generating components of these may, of course, be used singly or in combination. The polyamic acid obtained by using a branched diamine compound having a liquid crystal pretilt angle as a raw material has a polylysine which is represented by the following formula (7) and which is structurally arranged in the main chain. In other words, in the repeating unit represented by the general formula (5), one of the repeating unit structures is a polylysine containing a structure represented by the following formula (7) or dehydrating the polyamine. A closed-loop polyimine is preferred.

In the above formula (7), Y2 represents a tetravalent organic group, Y3 represents a trivalent organic group, and X and R are the same as defined in the above formula (1). Further, Y3 is preferably a skeleton selected from the group consisting of benzene 'biphenyl, diphenyl ether, diphenylethane, diphenylmethane and diphenylamine, and particularly preferably benzophenone. The diamine component in the case of polymerizing the polyamic acid used in the present invention is a diamine compound having a carbon number of 4 to 16 alkylene groups on the main skeleton and a branch having a liquid crystal pretilt angle. The amine compound may also be combined with an additional diamine compound -15 - (12) (12) 1343412. Specific examples of the additional diamine compound are shown below. The alicyclic diamine may, for example, be 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'- Diamino-3,3'-dimethyldicyclohexylamine, and isophoronediamine. Further, examples of the carbocyclic aromatic diamines include o-phenylenediamine, an exophenylene diamine, p-phenylenediamine, and diaminotoluene (for example, 2,4-diamino group). Toluene), hydrazine, 4-diamino 2-methoxybenzene, 2,5-diaminoxylene, 1,3-diamino-4-chlorobenzene' 1,4-diamino 2,5-dichlorobenzene']/-diamino-3-triisopropylbenzene, 2,2-bis(4-monophenyl)propane '4〆'-diaminodiphenylmethane, 2 , 2'-diaminostilbene, 4,4'-diaminostilbene, 4,4,-diaminodiphenyl ether '4,4'-diphenyl sulfide, 4,4 '-Diaminodiphenyl milling, 3:3'-diaminodiphenyl milling '4:4'-diaminobenzoic acid phenyl ester, 2,2 '-diaminobenzophenone, 4, 4'-Diaminodiphenylethanedione' bis(4-aminophenyl)methylphosphine oxide, bis(3-aminophenyl)thene, bis(4-aminophenyl)benzene Scale oxide, bis(4-aminophenyl)cyclohexylphosphine oxide, 4,4'-diaminodiphenylurea, 1,8-diaminonaphthalene, 1:5-diaminonaphthalene, 1,5 _diamino hydrazine, diamine Anthraquinone, bis(4-aminophenyl)diethyldecane, bis(4-aminophenyl)dimethyloxane, bis(4-aminophenyl)tetramethyldioxane, 3, 4'-Diaminodiphenyl ether, benzidine, 2:2'-dimethylbenzidine, 2:2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4 One (4-aminophenoxy)phenyl] code, 4:4'-bis(4-aminophenoxy)biphenyl' 2,2-bis-16-(13) (13)1343412 [4 - (4 -aminophenoxy)phenyl]hexafluoropropane, 1,4 bis(4-aminophenoxy)benzene, and 1,3-bis(4-aminophenoxy)benzene, In addition, as a heterocyclic diamine, 2,6-diaminopyridine ' 2,4-diaminopyridine, 2,4-diamino-s-triamine, 2,7-diaminodiphenyl And furan, 2,7-diaminocarbazole, 3,7-diaminophenothiazine 2,5-diamino-1,3,4-thiadiazole ring, and 2,4-diamine Base-6-phenyl-s-triamine and the like. The polyamine component having the structural unit represented by the above general formula (5) can be produced by reacting the above diamine component with tetracarboxylic acid dianhydride. In the present invention, the structure represented by the above formula (6) is preferably 20 to 95% of the structural unit represented by the general formula (5), particularly preferably 50 to 95 mol%, and 70 to 95%. better. Further, the structure represented by the above formula (7) is preferably 5 to 30% of the structural unit represented by the general formula (5), and may be 5 to 20% or 5 to 1 in accordance with the pretilt angle of the object. 〇%. In order to obtain the polylysine of such a structure, among the diamine components which are reacted with the tetracarboxylic acid dianhydride, the above-mentioned diamine compound having an alkylene group having 4 to 16 carbon atoms on the main skeleton, A branched diamine compound which increases the pretilt angle of the liquid crystal and, if necessary, an additional diamine compound, can be used in a respective ratio. There is no particular limitation on the tetracarboxylic acid dianhydride which is reacted with the above diamine component. Specific examples of the aromatic dianhydride include pyromellitic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, and 2,2':3,3'. -biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2 , 3,3',4'-dibenzophenone tetracarboxylic acid dianhydride, bis(3:4-dicarboxy-17-(14)(14)1343412 phenyl)ether dianhydride, double (3,4 Dicarboxyphenyl)disulfonic anhydride, 2,5,6-naphthalenetetracarboxylic acid dianhydride, and 2,3,6,7-naphthalenetetracarboxylic acid dianhydride. Further, examples of the alicyclic dianhydride include 1,2,3,4-cyclobutane tetraacid dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, and 2,3. 4,5-tetrahydrofurancarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, and 3,4-dicarboxyl 1,2,3,4 - tetrahydro-1-mononaphthalene succinic acid dianhydride, and the like. Of course, these dianhydrides can be used singly or in combination. Further, when Y1 of the above formula (6) or Y2 of the formula (7) is a structure of the following formula (8) * (8), it is preferable because the liquid crystal alignment property at the time of introducing a plurality of pretilt angle generating groups is excellent. Such a polyamic acid can be obtained by using pyromellitic dianhydride as a dianhydride. Further, when γι of the above formula (6) or Y2 of the formula (7) is a structure of the following formulas (9) and (9), a stable inclination angle can be obtained without depending on the friction condition, which is preferable. Such a polyamine acid can be obtained by using 1,2,3,4~~cyclobutylene tetracarboxylic acid dianhydride as a dianhydride. The poly-branched acid used in the present invention can be obtained by using the above-mentioned diamine and dianhydride in the presence of an organic solvent at a temperature of from 20 ° C to 150 ° C, preferably from 8 ° C to 8 ° C. '30 minutes to 24 hours' to] to 〇 hours is suitable for synthesis. -18- (15) (15) 133412 The molar ratio of the diamine to the dianhydride used in the reaction. If the amount of the diamine is too large, the molecular weight does not rise, and when the amount is too small, the acid anhydride remains and the storage stability deteriorates. Diamine / dianhydride = 0.5 to 3 · 〇 / 〇 莫 (Morby ratio) is preferred, diamine / dianhydride = 0.8 to 2.0 / 1.0 (mole ratio) is particularly good, of which diamine / two Anhydride = 1.0 to 1.2/1, preferably 0 (mole ratio). The solvent used in the polymerization reaction is not particularly limited, but hydrazine, hydrazine-dimethylformamide, hydrazine, hydrazine-dimethylacetamide 'N-methyl-2-pyrrolidone, hydrazine- When the methyl caprolactam 'dimethyl meth", tetramethyl urea, pyridine and butyrolactones have a high solubility in the poly-proline, it is suitable when the concentration of the solution in the polymerization reaction is too high. The workability of the obtained polyaminic acid solution is deteriorated, and when it is too low, the 'molecular weight does not rise' is preferably from 1 to 50% by weight, particularly preferably from 5 to 30% by weight, more preferably from 8 to 20% by weight. Further, in the range in which the polymer is dissolved, it is of course not necessary to add a butyl cellosolve or a poor solvent such as toluene or methanol. In the case of a polymerization reaction, when the reaction system is a nitrogen atmosphere or a solvent in a reaction system and a reaction is carried out in a nitrogen bubble, the molecular weight of the poly-proline is likely to increase, which is suitable. The polyimine is obtained from polyamic acid, and examples thereof include a method in which ruthenium is imidized by heating, or a method in which a chemical hydrazine imidization is carried out using a catalyst. Among them, in order to facilitate the reaction, it is difficult to cause a side reaction, and it is preferred to use a polyimine obtained by chemical imidization of a catalyst. The chemical imidization is carried out in a solution of polyamic acid, adding 2 to 20 moles of basic catalyst of lysine and 3 to 30 moles of acid anhydride of lysine, at 20 to 300 t:, 〇 to 25 ° ° C is suitable temperature, the reaction] to 00 hours is appropriate. -19 - (16) (16) 1343412 In this case, when the amount of the basic catalyst or the acid anhydride is small, the reaction does not proceed sufficiently. When the reaction is completed, it is difficult to completely remove the alkaline catalyst or the acid. The initiating catalyst may, for example, be pyridyl, triethylamine, trimethylamine, tributylamine or trioctylamine. Among them, pyridine is suitable because it has an appropriate basicity for carrying out the reaction. Further, examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, when acetic anhydride is used, it is preferable since the purification after the completion of the reaction becomes easy. A solution of polyaminic acid or polyimine which can be precipitated and recovered by injecting a poor solvent. In particular, when a catalyst is used to synthesize a polymer, when unreacted monomers remain in the solution, and when the solvent used in the synthetic polymer is not suitable for the component of the liquid crystal alignment agent, it is preferred to use the liquid crystal alignment agent after recovering the polymer. . The poor solvent used for the precipitation and recovery of the polymer is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, and ethanol. Toluene and benzene. The polymer obtained by precipitation is recovered by filtration, and dried at room temperature or under reduced pressure or under reduced pressure to form a powder. When the powder is redissolved in an excellent solvent and the reprecipitation operation is repeated for 2 to 10 times, the amount of impurities in the polymer is small, and the electrical properties of the liquid crystal alignment film are excellent, which is preferable. In addition, when three or more kinds of poor solvents such as alcohols, ketones, and hydrocarbons are used as the poor solvent, the purification efficiency can be further improved, which is suitable. Regarding the polymer other than polyglycine and polyimine, a monomer having an alkylene group having 4 to 16 carbon atoms in the main chain may be subjected to a monomer having a branch having an increased liquid crystal pretilt angle. Copolymerization method, or on a polymer of -20-(17)(17)1343412 having an alkylene group having 4 to 16 carbon atoms in the main chain, adding a branch of a liquid crystal pretilt angle, etc. The general method is derived. In the present invention, the reduction viscosity of the polymer for forming the liquid crystal alignment film is not particularly limited as long as it can form a uniform coating film, but it is preferably from 5 to 3.0 dl/g to 2 5 dl. /g is especially good, preferably 〇3 to]-5dl/g. If the reduction viscosity of the polymer is too high, the operation of the liquid crystal alignment agent becomes difficult. When the liquid crystal alignment film is produced when the liquid crystal alignment film is too low, the characteristics are unstable. c The alkylene having 4 to 16 carbon atoms as obtained above is obtained. A liquid crystal alignment agent of the present invention is formed based on a polymer having a branch on the main chain and having a pre-tilt angle for increasing the liquid crystal according to a solution which is suitable for application to a substrate. In this case, the polymer component contained in the liquid crystal alignment agent may be a mixture of two or more. Further, when two or more kinds of polymers are contained in the liquid crystal alignment agent, at least one of the alkylene groups having 4 to 6 carbon atoms is contained in the main chain, and the polymerization of the branch having an increase in the liquid crystal pretilt angle is obtained. Things can be. The solvent used in the liquid crystal alignment agent of the present invention is not particularly limited as long as it can uniformly dissolve the components contained therein, and examples thereof include N,N-dimethylformamide, ν, Ν- An excellent solvent for dimethylacetamide 'N-methyl-2-pyrrolidone, Ν-methyl caprolactam' dimethyl methacrylate, tetramethyl urea, pyridine and butyrolactone. Among them, when a guanamine-based solvent is contained, since the solubility of the polymer is high, it is suitable, and in particular, when yttrium-methyl-2-pyrrolidone or hydrazine or hydrazine-dimethylacetamide is contained, the printability of the liquid crystal alignment agent can be improved. So suitable. Further, butyl cellosolve or alkylene glycol monoalkyl ether such as propylene glycol monobutyl-21-(18)(18)1343412 ether, dialkylene glycol such as ethyl carbitol or dipropylene glycol monomethyl ether a dialkyl glycol dialkyl ether such as an alkyl ether, diethylene glycol dimethyl ether or diethylene glycol diethyl ether, an alkyl lactic acid such as ethyl lactate, or an alcohol such as methanol or ethanol Although the solubility of the polymer is low, the effect of improving the uniformity or smoothness of the coating film during printing is included in the liquid crystal alignment agent, so that such a poor solvent is mixed in a range in which the polymer component is not precipitated. It is appropriate. Specifically, it is preferred to use a solvent containing 30 to 99.9% by weight of an excellent solvent and 0.1 to 70% by weight of the above-mentioned poor solvent. When the solution concentration of the liquid crystal alignment agent of the present invention is too low, the liquid crystal alignment film becomes thin, and the reliability as a liquid crystal display element is deteriorated. When the liquid crystal display element is too high, the film thickness uniformity when applied to the substrate is impaired. The concentration of the resin component is preferably from 0.1 to 30% by weight, particularly preferably from 10 to 10% by weight. The liquid crystal alignment agent of the present invention thus obtained may of course be used by adding various additives such as a coupling agent and a crosslinking agent. When the coupling agent is added, the adhesion between the liquid crystal alignment film and the substrate is improved. Here, the term "coupler" means a compound having at least one or more kinds of elements selected from the group consisting of ruthenium and all of the typical metal elements to which the group 1 to group 3 belongs and all of the transition metal elements are covalently bonded to the oxygen atom. Among them, a coupling agent having an alkoxydecane, an alkoxy aluminum 'alkoxy zirconium and an alkoxytitanium structure is suitable because it is easy to obtain and excellent in cost. In particular, 3-aminopropyltrimethoxydecane is most suitable because it can improve the electrical characteristics when a liquid crystal display element is produced. Further, when the amount of the coupling agent added is large, the strength of the alignment film is weak, and when the amount is small, the effect of improving the adhesion is low, so the solid content in the liquid crystal compounding agent-22-(19)(19)1343412 is From 0.01 to 30% by weight, preferably from 0.1 to 20% by weight, particularly preferably from 0.5 to 10% by weight. With respect to the coupling agent described above, the coupling agent is diluted with a solvent in advance, and when it is injected into the liquid crystal alignment agent at a temperature of from 5 to 80 t, it is less likely to cause tackiness or uniformity of resin insolubilization. Liquid crystal alignment agent, so it is suitable. Further, the solvent and concentration of the diluted coupling agent are not particularly limited. For example, a solvent used in a polymer solution of N_methyl-2-pyrrolidone, dimethylacetamide, dimethylformamide, toluene, hexane, and 7-butyrolactone is used to dilute to 1 to 50% by weight, preferably used at a concentration of 3 to 3% by weight. After the liquid crystal alignment agent of the present invention is filtered, a coating film is formed on the substrate, and a liquid crystal alignment film can be formed by rubbing. In this case, the substrate to be used is not particularly limited, and a plastic substrate such as a glass substrate, a polyacrylate substrate or a polycarbonate substrate can be used. Further, a substrate formed using an I TO (indium tin oxide) electrode for liquid crystal driving or the like is of course suitable from the viewpoint of simplifying the flow. The liquid crystal alignment agent can be applied by a method such as a spin coating method, a printing method, or an inkjet method. In addition, after the coating film-coated liquid crystal alignment agent is formed, it is 50 to 300 ° C and 80 to 250 1: It is formed by drying at a suitable temperature for 1 to 1 minute. If the thickness of the formed film is too thick, it is disadvantageous in terms of cost. If the thickness of the liquid crystal display element is too thin, the reliability of the liquid crystal display element is lowered, so it is preferably 5 to 300 nm, preferably 7 to 100 nm, and preferably 1 to 80 nm. The rubbing treatment of the coating film is carried out by rubbing the surface of the film in the same direction by -23-(20) (20) 1343412 using a cloth such as nylon, rayon or cotton. At this time, the amount of rubbing of the rubbing cloth is preferably 〇1 to ]mm' of 0.1 to 0.7 mm, and in order to suppress the occurrence of dust, the amount of rubbing of the rubbing cloth is preferably small. After rubbing, the liquid crystal alignment film substrate is attached, and is washed with water, methanol, ethanol 'and isopropyl alcohol, etc.' to remove dust generated during rubbing. As a method of washing, the substrate is immersed in the liquid, and when ultrasonic waves are applied, dust can be efficiently removed, which is preferable. As the washing liquid, water, isopropyl alcohol or a water/isopropyl alcohol mixture is preferred. Especially for washing liquid containing isopropyl alcohol, it is preferable to perform ultrasonic cleaning for 1 minute or more. The thus obtained liquid crystal alignment film substrate-based dry cleaning liquid can be used for producing a liquid crystal display element. The present invention will now be described in more detail by way of examples, but the invention is not limited thereto. Further, in the examples, 5-indole [4-(4-heptylcyclohexyl)phenoxy]methyl}-, 3-diaminobenzene was synthesized by the following reaction route.

Mp: 153 - 157 °C > lH-NMR (CDC13' oppm) 7.09 ( 2H > d ) , 6.88 (2H, d) , 5.84 (2H, s) ’5.74

(lH, s), 4.74 (4H, s), 3.33 (2H's), 2.36 (1H, butyl), 1.77 (4H, m) &gt; 1.17 - 1.41 ( 16H &gt; m) , 1.01 ( 2 H &gt; m ) &gt; 0.8 8 ( 3 H &gt; t ). -24- (21) 1343412 [Examples] Examples <Example 1> Dissolve 7.47 g (26.09 mmol) of the 5-, 4-bis(4-amino)pentan and 1.09 g (2-89 mmol) of 4 - (18) Y-1,3-diaminobenzene in 80 g of N-methyl-2-pyrrolidine is abbreviated as NMP. 5.70 g (26.13 mm 〇I tetracarboxylic dianhydride was added thereto, and reacted at room temperature for 4 hours to obtain a reduction of 0.8 d/g (in a NMP having a concentration of 〇5 g/d ,, at 30 ° C Proline (a-1). The solution of polylysine (a-1) is diluted with NMP and butyl (hereinafter referred to as BCS), and the concentration of polyglycine is 5 BCS concentration of 20% by weight. Liquid crystal alignment of the present invention [Evaluation of pretilt angle] The above liquid crystal alignment agent was spin-coated on a glass substrate with a transparent electrode, 205 m of a filter of 0.25 m to form a film. A coating film having a thickness of 70 nm. In addition, the rayon cloth having a coating degree of 2 mm was impregnated to a volume of 〇.5 mm, and the roller was conveyed at a speed of 20 nim/s at a roller speed of 300 rpm, and the alignment film was attached. a liquid crystal alignment film substrate, which is applied in water for a minute to be washed, and then water droplets are blown off by an air gun, and then the base cellosolve of the aminophenoxy hydroxy) ketone (hereinafter referred to as the benzene viscosity) is determined. % by weight, calcined 1 minute after the test, and made a liquid crystal ultrasonic wave with a length of hair rotation, 8 (TC, dry -25 - (22) (22) 1343412 Dry for 1 〇 minutes. The substrate is grouped in groups of 2, and the gap of 5 Ο μ m is combined into the inner side of the alignment film surface, and the rubbing direction is reverse parallel, and liquid crystal is injected (MLC-2003, manufactured by Merck). A liquid crystal cell was formed, and the alignment state of the liquid crystal cell was confirmed to be a uniform alignment without defects when observed by a polarizing microscope. The liquid crystal cell was measured for the pretilt angle of the liquid crystal according to the crystal rotation method. The pretilt angle was first measured without liquid crystal. After the heat treatment after the injection, the heat treatment was carried out in the order of 105 ° C / 5 minutes, 120 ° C / 60 minutes, and the pretilt angle after each heat treatment was measured at room temperature. The result was based on the heat treatment before 1 ' 0 5 °C / 5 minutes after 'and' 2 0 °C / 6 0 minutes after the order, 4.8 degrees, 4.6 degrees, and 4.7 degrees, each condition has a high pretilt angle, and almost no heat treatment Pretilt angle change. <Example 2> Dissolve 7.47 g (26.09 mmo丨)], 5-bis(4-aminophenoxy)pentane and ll〇g (2.89 mmo)) 4 - [4~ ( 4-Heptylcyclohexyl)phenoxy]-1,3-diaminobenzene in 80 g of NMP. 5.70 g (26.13 mmol) of pyromellitic dianhydride was added and reacted at room temperature for 4 hours to obtain a reducing viscosity of about 9.9 dl/g (in a concentration of 〇.5 g/di Ν Μ P, Polyamine (a - 2 ) measured at 30 ° C. The solution of poly-proline (a - 2) was diluted with NMP and BCS, and the concentration of poly-proline was 5% by weight. The concentration of BCS was 20%. The liquid crystal alignment agent of the present invention is obtained in % by weight. The pretilt angle was evaluated using the above liquid crystal alignment agent' and the liquid crystal alignment agent of Example 1 in the same manner as -26-(23) (23) 1334112. As a result, the pretilt angle of the liquid crystal is 3.8 degrees, 3.9 degrees, and 4.2 degrees in order of heat treatment, after 105 ° C / 5 minutes, and after 12 〇 t / 60 minutes, and each condition has a high pretilt angle. Moreover, almost no change in the pretilt angle to the heat treatment was found. <Comparative Example 1> 4-(4'-diaminodiphenyl mystery of 3.06 g (15.28 mmol) of glutamic acid and 4-(octadecylhydroxy)-1 of 0.64 g (].70 mm〇l), 3~ Diaminobenzene in 47 g of NMP. 3.40 g (15.59 mmol) of pyromellitic dianhydride was added thereto and reacted at room temperature for 4 hours to obtain a reducing viscosity of about 0.7 d丨/g (in a concentration of 0.5 g/d Ν Μ P) Polyalginic acid (a-3) measured at 30 °C » A solution of polylysine (a-3) diluted with NMP and BCS, concentration of poly-aracine acid of 5% by weight, BCS concentration It is 20% by weight, and it is used as a liquid crystal alignment agent. The pretilt angle was evaluated in the same manner as the liquid crystal alignment agent of Example 1 using the above liquid crystal alignment agent. As a result, the pretilt angle of the liquid crystal is in the order of "6 · 3 degrees '6.0 degrees, and 5.6 degrees" before the heat treatment, after 1 0 5 / 5 minutes, and after 1 20 ° C / 60 minutes. Both showed a high pretilt angle 'but found a decrease in the pretilt angle for heat treatment. <Comparative Example 2> Dissolved 3.06 g (15.28 mmol) of 4,4'-diaminodiphenyl ether and 0.65 g (1.71 mmol) —[4-(4-Heptylcyclohexyl)benyloxy-27-(24) (24)1343412-yl]-1,3-diaminobenzene is at 478&gt;^1^?. 3.406 (1 5.59 mmol) of pyromellitic dianhydride was added thereto and reacted at room temperature for 4 hours to obtain a reducing viscosity of about 0.88 dl/g (in NMP at a concentration of 0.5 g/dl). , polyamine (a _ 4 ) measured at 30 ° C). A liquid crystal alignment agent for comparison was obtained by diluting a solution of poly-proline (a-4) with NMP and BCS, and having a polyamine concentration of 5% by weight and a BCS concentration of 20% by weight. The pretilt angle was evaluated in the same manner as the liquid crystal alignment agent of Example 1 using the above liquid crystal alignment agent. As a result, the pretilt angle of the liquid crystal is 5.6 degrees '5.4 degrees, and 5.0 degrees in the order of '1 05 ° C / 5 minutes before heat treatment and 1 20 ° C / 60 minutes, and the conditions are high. Pretilt angle, but found that the pretilt angle for heat treatment is reduced. <Example 3 &gt; 6.80 g (23.75 mmol) of I,5-bis(4-aminophenoxy)pentane and 47.47 g (].25 mmol) of 4-(octadecylhydroxy)- 1,3 -diaminobenzene in 68 g of NMP. 4.66 g (23.7 6mmo丨)], 2,3,4-cyclobutanetetracarboxylic acid dianhydride was added thereto, and reacted at room temperature for 4 hours to obtain a reducing viscosity of about 7.7 dl/g (at a concentration) Polyamine (a-5) measured at 30 ° C in an NMP of 0.5 g/dl. A solution of polyglycine (a-5) was diluted with NMP and BCS to have a polyglycine concentration of 5% by weight and a BCS concentration of 20% by weight to obtain a liquid crystal alignment agent of the present invention. Using the liquid crystal alignment agent described above, the liquid crystal alignment agent of Example 280 - (25) (25) 1334112 was used to evaluate the pretilt angle. The result is that the pretilt angle of the liquid crystal is before the heat treatment, l 〇 5 ° C / After 5 minutes, and after 120 ° C / 60 minutes, the order was 8.9 degrees, 8 · 8 degrees ' and 8.9 degrees. Each condition had a high pretilt angle, and almost no change in the pretilt angle to the heat treatment was observed. <Example 4> Dissolved 6.80 g (23.75 mmol) of 5-[4-(4-heptyl) ring of 5-bis(4-aminophenoxy)pentane and 48.48g (]_26mmo]) Hexyl)phenoxy]-1,3-diaminobenzene is 80 g of NMP. 4.66 g (2 3.76 mmol) of 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride was added thereto, and reacted at room temperature for 4 hours to obtain a reducing viscosity of about 0.8 dl/g (at a concentration of 〇.5g/dl of NMP, measured at 30 ° C) poly-proline (a - 6) 0 solution of poly-proline (a - 6 ), diluted with NMP and BCS, poly-proline concentration The liquid crystal alignment agent of the present invention was obtained in an amount of 5% by weight and a BCS concentration of 20% by weight. The pretilt angle was evaluated in the same manner as the liquid crystal alignment agent of Example 1 using the above liquid crystal alignment agent. As a result, the pretilt angle of the liquid crystal is 6.9 degrees, 6.8 degrees, and 7.2 degrees in the order of before the heat treatment, after 0 5 ° C / 5 minutes, and after 1 20 ° C / 60 minutes, and each condition has A high pretilt angle, and almost no change in the pretilt angle to the heat treatment was found. <Example 5> Dissolve 7.47 g (26.09 mmol) of 1,5-bis(4-aminophenoxy-29-(26)(26)1343412) pentene and 1.14 g (2.89 mmol) of 5 - {[4-(4-Heptylcyclohexyl)phenoxy]methyl}-1,3-diaminobenzene in 98 g of NMP. 6.14 g (28.15 mmol) of pyromellitic dianhydride was added thereto and reacted at room temperature for 4 hours to obtain a reducing viscosity of about 1.1 d丨/g (in NMP at a concentration of 0.5 g/dl, The poly(proline) acid (a-7) was titrated with Ν Μ P and BCS at a concentration of 30% by weight, and the concentration of BCS was 20% by weight, the liquid crystal alignment agent of the present invention is obtained. Using the liquid crystal alignment agent described above, the pretilt angle was evaluated in the same manner as the liquid crystal alignment agent of Example 1. The result was a pretilt angle of the liquid crystal before heat treatment, 1 〇 5 ° C / 5 minutes, and I 2 0 ° C / The order after 60 minutes, the conditions of 8.3 degrees '8.0 degrees, and 8.2 degrees' have high pretilt angles, and almost no change in the pretilt angle to the heat treatment. <Example 6> 20.02 g (100 μm) of diaminodiphenylmethane was dissolved with 115 g of hydrazine, hydrazine-dimethylacetamide at 115 g of 27-butyrolactone. 9.60 g (49 mmol) of 1:2,3,4-cyclobutanetetracarboxylic acid dianhydride and]0.90 g (50 mmol) of pyromellitic dianhydride were added thereto, and reacted at room temperature for 4 hours. The reduced viscosity is about 2. 2 dl / g (measured at 30 ° C in a concentration of 0.5 g / dl) of poly-proline (a - 8). In the solution of poly-proline (a-8), add 3% aminopropyltrimethoxydecane diluted with hydrazine and N-dimethylacetamide (LS-3150 -30- (27) (27) 1334312: manufactured by Shin-Etsu Chemical Co., Ltd.) 'Made 3-aminopropyltrimethoxydecane to 1% by weight relative to polyglycolic acid, then dilute with 7-butyrolactone, polyglycine concentration It is a 5% by weight solution. Mixing the above prepared lysine (a-8) 5% solution with the 5% solution of the polylysine (a-1) prepared in Example 1 to form a weight of pyridyl (a-8) / ( a - 1 ) = 4/1 'The liquid crystal alignment agent of the present invention is obtained by thorough stirring. The pretilt angle was evaluated in the same manner as the liquid crystal alignment agent of Example 1 using the above liquid crystal alignment agent. The result is that the pretilt angle of the liquid crystal is 4.0 degrees, 4.1 degrees, and 4.3 degrees in the order of: before, after, after, after, after, after, after,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, And almost no change in the pretilt angle to the heat treatment was found. <Example 7> The liquid crystal alignment agent obtained in Example was filtered by a filter of 〇·5 // ηι, and then spin-coated on a glass substrate with a transparent electrode, and calcined at 200 ° C / 30 minutes. A film having a film thickness of 70 nm was formed. Further, this coating film was rubbed with a rayon cloth having a hair length of 2 mm, and the amount of impregnation was 〇.3nim', the number of rotation of the roller was 300 rpm, and the speed of the roller was 40 mm/s to form a liquid crystal alignment film. The substrate to which the liquid crystal alignment film was attached after rubbing was subjected to ultrasonic cleaning in isopropyl alcohol for a minute, and then water droplets were blown off with an air gun, and dried at 80 ° C for 10 minutes. The substrate is grouped into two sheets, and the gap is formed by a gap of 50 Am, and the inner surface of the alignment film is combined, and the rubbing direction is reverse-flat-31 - (28) (28) 1343412 lines, and liquid crystal is injected (Merck MLC - 2003), in the liquid crystal cell, the liquid crystal pretilt angle measured by the crystal rotation method was 9.9 degrees with respect to the above liquid crystal cell. When the alignment state of the liquid crystal cell was observed by a polarizing microscope, it was confirmed that the liquid crystal was uniformly distributed without defects, and although it had weak rubbing conditions and washing with an organic solvent, it had good alignment and high pretilt angle. <Example 8> Using the liquid crystal alignment agent obtained in Example 2, the same evaluation as in Example 7 was carried out. As a result, the pretilt angle of the liquid crystal was 8.7 degrees, and it was confirmed that the liquid crystal was uniform without defects, and although it had weak friction conditions and washing with an organic solvent, it had good alignment and high pretilt angle. <Example 9> Using the liquid crystal alignment agent obtained in Example 3, the same evaluation as in Example 7 was carried out. As a result, the pretilt angle of the liquid crystal was 8.7 degrees, and it was confirmed that the liquid crystal was uniform without defects, and although it had weak friction conditions and washing with an organic solvent, it had good alignment and high pretilt angle. <Example 1 〇> Using the liquid crystal alignment agent obtained in Example 4, the same evaluation as in Example 7 was carried out. As a result, the pretilt angle of the liquid crystal was 7.3 degrees, and it was confirmed that the liquid crystal was uniform without defects, and although it had weak friction conditions and washing with an organic solvent, it had good alignment and high pretilt angle. -32 - (29) 1343412 The liquid crystal display element produced by using the liquid crystal alignment agent of the present invention has a high pretilt angle, and does not cause a decrease in the pretilt angle when the display element is thermally aged. Liquid crystal display element. Further, the liquid crystal alignment film produced by using the liquid crystal alignment agent of the present invention has good alignment property and high pretilt angle despite the weak rubbing conditions and the washing of an organic solvent such as isopropyl alcohol. -33-

Claims (1)

1343412 Patent Application No. 093 1丨2675 Revised Patent Application Scope Amendment of the Chinese Patent Application March 18, 100. The liquid crystal alignment agent has a carbon number of 4 to 16 in the main chain. The alkylene group and the polymer having a branch which increases the pretilt angle of the liquid crystal have a polyamic acid having a repeating unit represented by the general formula (5), or dehydrating the polyamic acid. Closed-loop polyimine, (In the formula, A represents a tetravalent organic group, and B represents a divalent organic group). 2. The liquid crystal alignment agent of claim 1, wherein, for the repeating unit represented by the general formula (5), one of the repetitive structures has a structure as shown in the formula (6). (wherein Y1 represents a tetravalent organic group, and k represents an integer of 4 to 16). 3. The liquid crystal alignment agent of claim 1, wherein one of the repetitive structures represented by the general formula (5) has (7) m3412 (wherein Y2 represents a tetravalent organic group, Y3 represents a trivalent organic group, and X represents a single bond or a divalent bond group] R represents at least one selected from the group consisting of 4 to 4 carbon atoms 20 alkyl groups, a fluorinated alkyl group having 4 to 20 carbon atoms, a group having 1 to 3 benzene rings or a cyclohexane ring, and an organic group in which groups having a steroid skeleton are grouped. 4. The liquid crystal alignment agent of claim 2, wherein, for the repeating unit represented by the general formula (5), one of the repetitive structures has a structure as shown in the formula (7). (7) (wherein Υ2 represents a tetravalent organic group, Υ3 represents a trivalent organic group, X represents a single bond or a divalent bond group, and R represents at least one selected from the group consisting of carbon atoms a group of 4 to 20 alkyl groups, a fluorinated alkyl group having 4 to 20 carbon atoms, a group having 1 to 3 benzene rings or a cyclohexane ring, and a group having a steroid skeleton Organic base). 5. The liquid crystal alignment agent of claim 4, wherein for the repeated unit shown in the general formula (5), the structure represented by the formula (6) in the repeated structure is 20 to 95%, 7) The structure shown is 5 to -2- 30% 1343412. 6. The liquid crystal alignment agent according to any one of claims 2 to 5, wherein Y1 or (7) of the formula (6) Y2 is a structure as shown in (8) or (9), -3-