CN101824327B

CN101824327B - Alignment agent and liquid crystalline polyimide used therein

Info

Publication number: CN101824327B
Application number: CN201010111595XA
Authority: CN
Inventors: 田村典央; 小口雄二郎
Original assignee: JNC Corp; Chisso Petrochemical Corp
Current assignee: Changsha Dao'anjie New Materials Co ltd
Priority date: 2009-01-29
Filing date: 2010-01-28
Publication date: 2013-04-10
Anticipated expiration: 2030-01-28
Also published as: CN101824327A; KR101184319B1; KR20100088072A

Abstract

The invention relates to an alignment agent and liquid crystalline polyimide used therein. The invention provides an alignment film which has excellent alignment performance, high light sensitivity and stability. The alignment agent contains at least one polymer in the polyimide obtained from polyamic acid and by the dehydration reaction of the polyamic acid and the composition of the solvent. The concentration of the polymer in the composition is 0.1wt%-40wt%, the total amount of the film forming components contained in the composition is 50wt%-100wt% of the reference polymer proportionality, and the composition can be formed into a film having the liquid crystal temperature range between 100 DEG C and 300 DEG C by film forming of the composition.

Description

Employed liquid crystalline polyimide in orientation agent and this orientation agent

Technical field

The present invention relates to a kind of orientation agent of mainly in the manufacturing of liquid crystal display device, using.

Background technology

Liquid crystal display device is used to also be used to recently in the TV (television) with in the various liquid crystal indicators such as the view finder (view finder) of the pick up camera (video camera) headed by the watch-dog (monitor) of notebook computer (notebook personal computer) or desktop computer (desktop personal computer), projection display equipment (projectiondisplay).In addition, liquid crystal display device also is used as photoelectron (optoelectronics) related elements such as optical print head (optical printer head), optical Fourier transform element (optical Fourier transform device), light valve (light valve).The main flow of previous liquid crystal display device is the display element that has used nematic liquid crystal (nematic liquid crystal), and near the alignment direction of the liquid crystal the alignment direction that is positioned near the liquid crystal a side the substrate and the substrate that is positioned at the opposing party is with twisted-nematic (the Twisted Nematic of the angles distortion of 90 degree, TN) pattern and described alignment direction are usually just to be able to practical more than or equal to the supertwist of the angles distortion of 180 degree to the liquid crystal display device of row (Super TwistedNematic, STN) pattern etc.And, used the liquid crystal display device of so-called thin film transistor (Thin-film-transistor, the TFT) pattern of thin film transistor (transistor) also just being able to practical.

Yet these liquid crystal display device rightly visual angle of recognition image are narrow and small, the situation that exists brightness or contrast gradient (contrast) to descend during from oblique watching, and sometimes produce the brightness counter-rotating with middle tone.In recent years, the problem at this visual angle the TN type liquid crystal display device by using optical compensation films, and with multizone (the Multi-domainVertical Alignment arranged vertically of the technology of vertical orientation and protruding structure, MVA) plane conversion (In-Plane Switching, the IPS) pattern (such as with reference to patent documentation 2) of pattern (for example with reference to patent documentation 1) or Transverse electric-field type etc. obtains improvement.

The development of liquid crystal display device technology is not only reached by type of drive or the component structure of improveing these liquid crystal display device, and reaches by employed component parts in the improvement display element.Among the employed component parts, especially liquid crystal orienting film is one of important factor relevant with the display quality of liquid crystal display device in the display element, and along with high-qualityization of display element, it is important that the effect of liquid crystal orienting film becomes day by day.

For this kind liquid crystal orienting film, uniform display characteristic for liquid crystal display device, must control equably the molecular arrangement of liquid crystal, therefore require to make on the substrate liquid crystal molecule equably orientation from real estate, show in addition fixing inclination angle (tilt angle (pretiltangle)) in one direction.As mentioned above, the direction of the liquid crystal molecule on the substrate is arranged in consistent liquid crystal orienting film and becomes technology important and indispensable in the manufacturing step of liquid crystal display device.

Liquid crystal orienting film is prepared by crystal aligning agent.At present, the main crystal aligning agent that uses is to make the polyimide (polyimide) of polyamic acid (polyamic acid) or solubility be dissolved in the solution that forms in the organic solvent.After on the substrate, making its film forming form polyimide by methods such as heating is liquid crystal orienting film with this kind solution coat.Industry also is studied the various crystal aligning agents except polyamic acid, but with regard to the aspects such as thermotolerance, chemical-resistant (anti-liquid crystal liquid crystal property), coating, LCD alignment, electrical property, optical characteristics, display characteristic, almost not practical.

Industrial extensive utilization both easy and friction (rubbing) method that can carry out large-area high speed processing as the orientation facture.Rubbing manipulation is to use the cloth of implanting the fiber that nylon (nylon), artificial silk (rayon), polyester (polyester) etc. are arranged, processing along the surface of direction friction liquid crystal orienting film can obtain the consistent orientation of liquid crystal molecule thus.Yet rubbing manipulation is pointed out to exist problem points such as producing dust, static.

Up to now, as the orientation mechanism of the liquid crystal on the alignment film of implementing the orientation processing by friction treatment, proposing has following two kinds:

(1) by the surface shape effect of the caused liquid crystal orienting film of the microflute that utilizes friction treatment to produce (microgroove);

(2) carry out the molecular interaction of the liquid crystal unimolecular layer that the liquid crystal orienting film of single shaft orientation contacts with liquid crystal orienting film therewith by friction treatment.

In recent years, can confirm that the contribution of surface shape effect of (1) is less, the contribution of the molecular interaction of (2) is dominant.

Known when adopting this kind rubbing manipulation, usually can give the larger orientation restraint for liquid crystal (anchoring energy (anchoring energy)) to polyimide film.Yet when adopting this rubbing manipulation, there are the following problems, namely, if observe with molecular level (molecular level) by the direction that is implanted in the hair friction film in the friction cloth, so also inhomogeneous, the result causes the LCD alignment at alignment film interface to get muddled.In addition, exactly because also produce scar etc. by the contact of cloth at film, when making liquid crystal display device be black display (normally aobvious black formula (normallyblack mode)) when not applying voltage, black level (black level) is less than ideal situation, and this kind phenomenon is by known to the industry.

On the other hand, implement the light orientation method that orientation is processed about irradiation light, proposing has the multiple orientation mechanism such as photolysis method, photoisomerization method, photodimerization method, optical cross-linking method (for example with reference to non-patent literature 1, patent documentation 3 and patent documentation 4).Especially, it is generally acknowledged because light orientation method is the non-contacting alignment method different from rubbing manipulation therefore as the orientation mechanism of liquid crystal, only have the molecular interaction of (2) to play a role.

The known following phenomenon of dealer: the homogeneity of the orientation of light orientation facture is higher than rubbing manipulation, and is non-contacting orientation method, so can not produce scar on the film, and for rubbing manipulation, easier raising black level.And light orientation facture can reduce sends out dirt or static etc. produce unfavorable condition when making liquid crystal display device reason, and its advantage is more.Yet the anchoring energy of light orientation facture is less than rubbing manipulation, and this situation can cause decline or the trace of response speed, therefore need to be improved.

In order to overcome the shortcoming of this kind light orientation, the people such as present inventor have found following method: by the method that discloses in the patent documentation 3 for example, the crystal aligning agent that will comprise polyamic acid shines light after being coated on the substrate, then calcines.Can obtain to have the light alignment film of larger anchoring energy by this method, but in order to obtain to have the liquid crystal orienting film of sufficient anchoring energy, have to increase the rayed energy, and must further improve.

No. 2947350 communique of [patent documentation 1] Japanese Patent

No. 2940354 communique of [patent documentation 2] Japanese Patent

[patent documentation 3] Japanese Patent Laid-Open 2005-275364 communique

[patent documentation 4] Japanese patent laid-open 11-15001 communique

[non-patent literature 1] liquid crystal, the 3rd volume, No. 4, the 262nd page, 1999 years

Summary of the invention

The object of the present invention is to provide a kind of higher friction alignment film of homogeneity of orientation.And, the object of the present invention is to provide the light alignment film that a kind of light sensitivity is good and stability is higher.

The people such as present inventor are studied exploitation hardy, found that by friction or light and give after the anisotropy having the higher polyimide material of liquid crystal liquid crystal property and thermotolerance, heat until till the liquid crystal temperature of this polyimide, regiospecific increases by this, thereby finishes the present invention.Essence of the present invention is liquid crystalline polyimide as alignment film material.The present invention be by following [1] represented.

[1] a kind of orientation agent, it contains at least a polymkeric substance and the solvent composition thing that is selected from the polyimide that polyamic acid and the dehydration reaction by this polyamic acid obtain, it is characterized in that: the concentration of the polymkeric substance in this constituent is 0.1wt%～40wt% (weight percent), in this constituent the total amount of contained film forming component as the ratio of the described polymkeric substance of benchmark as 50wt%～100wt%, and can be formed on the film that has liquid crystal temperature range between 100 ℃～300 ℃ by making this constituent film forming.

[effect of invention]

If for example as crystal aligning agent, can provide so the higher friction alignment film of homogeneity of orientation with orientation agent of the present invention.And, the light alignment film that light sensitivity is good and stability is higher can be provided.

Description of drawings: nothing

Embodiment

The term that uses among the present invention is described.

Sometimes will be labeled as compound (I-1) by the represented compound of formula (I-1).Sometimes to also being noted by abridging in an identical manner by the represented compound of other formulas.

Employed term " arbitrarily " expression " not only the position can freely be selected, and quantity also can freely be selected " during chemical formula defined.For example the statement of " A can be replaced by B, C, D or E arbitrarily " can be by the implication of B, C, D or E replacement except an A, and any one of a plurality of A all can be by beyond the implication of any one replacement among B, C, D and the E, the A that also has the A that replaced by B, replaced by C, the A that is replaced by D and the A that replaced by E both can mix the implication of existence at least.Yet, when arbitrarily-CH ₂-in the time of can being replaced by other groups, precondition be continuous a plurality of-CH ₂-can't be replaced by other identical groups.

In chemical structural formula, surround the group (ring A) of the group representative ring structure of literal (for example A) by sexangle, Me represents methyl.

With the carbon that consists of ring any not clearly the substituting group of bond represent that its bond position is freely in the scope without the chemical problem.

In a plurality of formulas, use the situation of identical mark to represent that this group has the identical range of definition, must not be simultaneously identical group but be not illustrated in all formulas.When this kind situation, can in a plurality of formulas, select identical group, also can in each formula, select different groups.

The present invention be by described [1] with following [2]～[22] formation.

[2] according to [1] described orientation agent, polyamic acid is the polyamic acid that has photosensitive group on the main chain.

[3] according to [2] described orientation agent, photosensitive group is at least a by the represented group of formula (I)～formula (VI):

-R ¹-C≡C-R ²- (I)

-R ¹-C≡C-C≡C-R ²- (II)

-R ¹-C≡C-CH＝CH-R ²- (III)

-R ¹-C≡C-R ²-C≡C-R ³- (IV)

-R ¹-C≡C-R ²-CH＝CH-R ³- (V)

-N＝N- (VI)

Herein, R ¹, R ²And R ³Independent is aromatic divalent group.

[4] according to [2] described orientation agent, the polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, that is, make by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a with by formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and represented at least a of tetracarboxylic dianhydride of formula (VIII-8) react:

Herein, R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group (alkylene).

[5] according to [2] described orientation agent, the polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, that is, make by at least a of the represented tetracarboxylic dianhydride with photosensitive group of formula (IV-4) and formula (VI-8) with reacted by represented at least a of diamines of formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6):

Herein, R ⁴That carbon number is 6～20 alkylidene group; R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group.

[6] according to [2] described orientation agent, the polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, that is, make disclose in [4] by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a with by disclose among at least a mixture of the represented diamines of formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6) and [4] by formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and represented at least a of tetracarboxylic dianhydride of formula (VIII-8) react:

H ₂N-R ⁴-NH ₂ (VII-1)

[7] according to [2] described orientation agent, the polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, that is, make disclose in [5] by at least a of the represented tetracarboxylic dianhydride with photosensitive group of formula (IV-4) and formula (VI-8) with by formula (VII-4), formula (VII-5), that discloses among the tetracarboxylic dianhydride's that formula (VIII-7) and formula (VIII-8) are represented at least a mixture and [5] is reacted by formula (VII-1)～formula (VII-3) and formula (VIII-1)～represented at least a of diamines of formula (VIII-6):

Herein, R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group.

[8] according to [2] described orientation agent, the polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, that is, make disclose in [4] by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a with select disclose among at least a mixture in the represented diamines of free style (2)～formula (4) and [4] by formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and represented at least a of tetracarboxylic dianhydride of formula (VIII-8) react:

Herein, A ¹, A ², A ³And A ⁴Independent of stretching cyclohexyl (cyclohexylene) or inferior benzene (phenyl); X ³And X ⁴Independent for singly-bound, carbon number be 1～5 alkylidene group or-O-; X ⁵And X ⁶Independent be singly-bound ,-CH ₂-,-CH ₂CH ₂-,-O-or-S-; Y ¹Be-CH ₂-,-C (R ¹¹) (R ¹²)-,-CO-or-SO ₂-, R ¹¹And R ¹²Independent for hydrogen, carbon number be that 1～12 alkyl or carbon number are 1～12 fluorinated alkyl; M1, m2, m3, m4 and n independently represent 0 or 1.And, stretch in cyclohexyl and the inferior benzene described, hydrogen can be 1～4 alkyl or benzyl replacement by carbon number arbitrarily, these substituent bond positions are arbitrarily; But, work as A ¹, A ², A ³And A ⁴When all being Isosorbide-5-Nitrae-Ya benzene, X ³, X ⁴, X ⁵And X ⁶All be not singly-bound:

Herein, X ¹And X ²Be singly-bound ,-O-,-COO-,-OCO-,-NH-,-CONH-or carbon number are 1～12 alkylidene group; G ¹And G ²That to be selected from carbon number be that 6～12 aromatic ring and carbon number are the divalent group of 1～3 rings in 3～12 the ester ring type ring for singly-bound or contain; R ⁶Be hydrogen, fluorine ,-CN ,-OH, carbon number are that 1～30 alkyl, carbon number are that 1～30 fluorinated alkyl or carbon number are 1～30 alkoxyl group; And, work as X ¹, G ¹, X ²And G ²When all being singly-bound, R ⁶Be that carbon number is that 3～30 alkyl, carbon number are that 3～30 fluorinated alkyl or carbon number are 3～30 alkoxyl group, work as G ²Singly-bound and X ²Neither when singly-bound neither alkylidene group, R ⁶Be that hydrogen or carbon number are 3～30 alkyl, work as G ¹And G ²When being singly-bound, X ¹, X ²And R ⁶The total carbon number more than or equal to 3:

Herein, R ⁷That hydrogen or carbon number are 1～12 alkyl; Ring B be arbitrarily hydrogen can by carbon number be the Isosorbide-5-Nitrae that replaces of 1～4 alkyl-Ya benzene or arbitrarily hydrogen can be the Isosorbide-5-Nitrae that replaces of 1～4 alkyl-stretch cyclohexyl by carbon number; X ⁰Be that singly-bound or carbon number are 1～5 alkylidene group, and s is 0～3 integer; When s was 2 or 3, a plurality of ring B can all be identical ring, also can be made of a plurality of X at least 2 different rings ⁰Can all be identical group, also can be consisted of by at least 2 different groups; Z ¹And Z ²Independent be singly-bound ,-CH ₂-,-CH ₂CH ₂-or-O-, t1 and t2 independently are 0～3 integer; When t1 is 2 or 3, a plurality of Z ¹Can all be identical group, also can be consisted of by at least 2 different groups; When t2 is 2 or 3, a plurality of Z ²Can all be identical group, also can be consisted of by at least 2 different groups.

[9] according to [2] described orientation agent, the polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, namely, make that [4] middle term discloses by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a, at least a by the represented diamines of formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6) of disclosing in [6], and selecting of disclosing in [8] disclose among at least a mixture in the represented diamines of free style (2)～formula (4) and [4] by formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and represented at least a of tetracarboxylic dianhydride of formula (VIII-8) react.

[10] according to [1] described orientation agent, polyamic acid is by making by at least a of the represented diamines of formula (VII-1)～formula (VII-3) and at least a polyamic acid that obtains that reacts by the represented tetracarboxylic dianhydride of formula (VIII-7) and formula (VIII-8), or by making by at least a of the represented diamines of formula (VIII-1)～formula (VIII-6) and at least a polyamic acid that obtains that reacts by the represented tetracarboxylic dianhydride of formula (VII-4) and formula (VII-5):

H ₂N-R ⁴-NH ₂ (VII-1)

Herein, R ⁴That carbon number is 6～20 alkylidene group; And, R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group.

[11] a kind of liquid crystal orienting film, it is to obtain in the following way, that is, give anisotropy by friction or rayed to being coated on the film that obtains on the substrate according to [1] described orientation agent, then be heated to till the liquid crystal temperature range of film and make the anisotropy increase of film.

[12] a kind of liquid crystal orienting film, it is to obtain in the following way, namely, give anisotropy by rayed to being coated on the film that obtains on the substrate according to each described orientation agent in [2] to [9], then be heated to till the liquid crystal temperature range of film and the anisotropy of film is increased.

[13] a kind of liquid crystal orienting film, it is to obtain in the following way, that is, give tribological anisotropy to being coated on the film that obtains on the substrate according to [10] described orientation agent, then be heated to till the liquid crystal temperature range of film and the anisotropy of film is increased.

[14] a kind of liquid crystal display device has according to [11] described liquid crystal orienting film.

[15] a kind of liquid crystal display device has according to [12] described liquid crystal orienting film.

[16] a kind of liquid crystal display device has according to [13] described liquid crystal orienting film.

[17] a kind of polyimide or as the polyamic acid of its precursor comprises by the represented Component units of formula (IX), and have liquid crystal temperature range in 100 ℃～300 ℃:

Herein, R ⁵That carbon number is 6～12 alkylidene group; R ⁹By any one the residue in the represented diamines of formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), formula (V-1) and formula (VI-1)～formula (VI-7).

[18] a kind of polyimide or as the polyamic acid of its precursor comprises by the represented Component units of formula (X), and have liquid crystal temperature range in 100 ℃～300 ℃:

[19] according to [17] described polyimide or as the polyamic acid of its precursor, R ⁹By any one the residue in the represented diamines of formula (VIII-1)～formula (VIII-6).

[20] according to [18] described polyimide or as the polyamic acid of its precursor, R ⁹By any one the residue in the represented diamines of formula (VIII-1)～formula (VIII-6).

[21] a kind of polyimide or as the polyamic acid of its precursor comprises by the represented Component units of formula (IX) and by the represented Component units of formula (XI), and have liquid crystal temperature range in 100 ℃～300 ℃:

Herein, R ⁵That carbon number is 6～12 alkylidene group; R ⁹By any one the residue in the represented diamines of formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), formula (V-1) and formula (VI-1)～formula (VI-7); R ¹⁰By any one the residue in the represented diamines of formula (VIII-1)～formula (VIII-6).

[22] a kind of polyimide or as the polyamic acid of its precursor comprises by the represented Component units of formula (X) and by the represented Component units of formula (XII), and have liquid crystal temperature range in 100 ℃～300 ℃:

Orientation agent of the present invention is to contain the constituent that is selected from least a polymkeric substance in the polyimide that polyamic acid and the dehydration reaction by this polyamic acid obtain, and in this constituent contained film forming component total amount as the ratio of the described polymkeric substance of benchmark as 50wt%～100wt%.And, by making this constituent film forming, can be formed on the film that has liquid crystal temperature range between 100 ℃ to 300 ℃.That is, this orientation agent is coated on the substrate and makes its film forming, and by friction or irradiation light film is given after the anisotropy, heat until till the liquid crystal temperature range of this film, can form by this regiospecific and increase, and have the alignment film of higher regiospecific.Contain described polymkeric substance as the orientation agent of principal constituent by use, can make the higher film of thermostability and chemical stability.

Glass transition point (glasstransition point) when employed polyamic acid is made polyimide among the present invention is mobile less than common polyimide easily because of main polymer chain, and less than or equal to liquid crystal temperature.Therefore, utilize the orientation agent of the present invention take this kind polyamic acid as principal constituent, even if be the calcining of lower temperature, also can obtain the higher film of imide rate.In the following description, as long as in advance without specifying, just " employed polyamic acid among the present invention " only is expressed as " polyamic acid ".

As mentioned above, alignment film of the present invention is by bringing into play its performance till the liquid crystal temperature range that is heated to material.When giving anisotropy by rubbing manipulation to film, in order to prevent the fracture of film, generally be handled as follows, that is, the orientation agent is coated on the substrate, remove after the solvent by precalcining, under about 200 ℃, calcine, then rub.Yet, if can prevent the fracture of film by the selection of material, even if after precalcining, rub so, then about 200 ℃, calcine simultaneously with also harmless in order to increase anisotropic heat treated down.

Because light orientation method can be given anisotropy to alignment film with cordless, therefore needn't worry the film fracture.That is, because light orientation method can be carried out hot-imide and heat treated simultaneously after the use polyamic acid carries out the light orientation, therefore better as alignment film of the present invention being given anisotropic method.According to this reason, be preferably the temperature of selecting hot-imide and be in the interior material of liquid crystal temperature range.

Sometimes according to the kind of base material, the ultimate temperature of heat treated is restricted, but the orientation agent of the application of the invention, can be formed on the film that has liquid crystal temperature range in 100 ℃～300 ℃ the scope.At this moment, when forming the alignment film with respect to employed nematic liquid crystal, in order to keep the stability of orientation, comparatively ideal being selected at is preferably 150～300 ℃, is more preferably the material that has liquid crystal temperature range in 180 ℃～300 ℃ the scope.

In order to utilize described smooth orientation method, orientation agent of the present invention is preferably and contains the polymkeric substance with photosensitive group.As this photosensitive group, can select to have well-known all photosensitive groups of light orientation ability.Yet, if use the photosensitive group that shows the orientation ability by photodimerization or photolysis, follow so the rayed condition and the possibility that causes the liquid crystal temperature range of material to change is higher.Therefore, in the present invention, be preferably the photosensitive group that uses the photoisomerization type.

That is, in the present invention, be preferably and use at least a polymkeric substance that has following photosensitive group on the main chain.

-R ¹-C≡C-R ²- (I)

-R ¹-C≡C-C≡C-R ²- (II)

-R ¹-C≡C-CH＝CH-R ²- (III)

-R ¹-C≡C-R ²-C≡C-R ³- (IV)

-R ¹-C≡C-R ²-CH＝CH-R ³- (V)

-N＝N- (VI)

R ¹, R ²And R ³Independent is aromatic divalent group, and the better example of aromatic series divalent group is Isosorbide-5-Nitrae-Ya benzene, 1, the inferior benzene, 4,4 of 3-'-Lian Ya benzene and ditan-4,4 '-two bases.The arbitrarily hydrogen of these rings can be replaced by methyl, methoxyl group, trifluoromethyl, methoxycarbonyl, fluorine or chlorine.And, among these groups, be more preferably the inferior benzene of Isosorbide-5-Nitrae-Ya benzene and 1,3-, best is Isosorbide-5-Nitrae-Ya benzene.

By selecting by formula (I)～represented photosensitive group of formula (VI), light regiospecific characteristic large and the of the present invention smooth orientation agent that light sensitivity is higher is manifested to greatest extent.Two kinds of isomer that in two keys of the photosensitive group of formula (III) and formula (V), have cis (cis) or trans (trans), but smooth orientation agent of the present invention can be used in these isomer any.

In order to obtain to have on the main chain at least a polyamic acid by the represented photosensitive group of formula (I)～formula (VI), be used as raw material as long as will have diamines or the carboxylic acid dianhydride of this kind photosensitive group.Especially, in order to obtain higher light regiospecific, be preferably and use the raw material that has photosensitive group in the diamines.

Having the diamines of this kind photosensitive group and tetracarboxylic dianhydride's better example is compound (I-1)～compound (I-3), compound (II-1)～compound (II-3), compound (III-1), compound (IV-1)～compound (IV-4), compound (V-1) and compound (VI-1)～compound (VI-8).In addition, in the following description, sometimes with the tetracarboxylic dianhydride referred to as acid anhydrides.

When making polyamic acid, can will not have diamines or acid anhydrides and the described compound of photosensitive group and use.At this moment, the Tg of the polyimide that obtains for the dehydration reaction that reduces easily by this polyamic acid is preferably selection and can is with carbon number diamines or acid anhydrides on the main chain that 6～20 alkylidene group imports to polymkeric substance.In order further to reduce Tg, this alkylidene group arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-the COO-replacement.As this kind diamines and acid anhydrides, particularly preferred is by following formula (VII-1)～represented compound of formula (VII-5).

H ₂N-R ⁴-NH ₂ (VII-1)

Herein, R ⁴Be that carbon number is 6～20 alkylidene group, carbon number is preferably 6～12.R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group.R preferably ⁵One-CH ₂-the carbon number that can be replaced by-O-is 6～12 alkylidene group.And, R ⁵Better example be do not exist with group in-CH ₂The carbon number of-relevant replacement is 6～12 alkylidene group, that is-C ₆H ₁₂The C of-～- ₁₂H ₂₄-.

And, in order easily to show liquid crystal liquid crystal property, and use that the diamines or the acid anhydrides that form of straight line bond is also better as much as possible with aromatic nucleus aggregate and 2 amidos or 2 carboxyls.As this kind diamines and acid anhydrides, particularly preferred is by following formula (VIII-1)～represented compound of formula (VIII-8).

In the present invention, also may be used diamines the diamines that in explanation so far, has listed.For example, when the alignment film in the liquid-crystal display purposes, alignment film used as the nematic liquid crystal constituent, can use expression voltage retention (Voltage Holding Ratio, VHR) higher and be difficult to produce the well-known diamines of the so-called electrical property excellence of the characteristic such as trace.

As the better example of the well-known diamines of this kind, can enumerate by the represented diamines of formula (2).

In formula (2), A ¹, A ², A ³And A ⁴Independent of stretching cyclohexyl or inferior benzene; X ³And X ⁴Independent for singly-bound, carbon number be 1～5 alkylidene group or-O-; X ⁵And X ⁶Independent be singly-bound ,-CH ₂-,-CH ₂CH ₂-,-O-or-S-; Y ¹Be-CH ₂-,-C (R ¹¹) (R ¹²)-,-CO-or-SO ₂-, R ¹¹And R ¹²Independent of hydrogen, carbon number are that 1～12 alkyl or carbon number are 1～12 fluorinated alkyl, be preferably hydrogen, methyl or-CF ₃M1, m2, m3, m4 and n independently represent 0 or 1.And, stretch in cyclohexyl and the inferior benzene described, hydrogen can be 1～4 alkyl or benzyl replacement by carbon number arbitrarily, these substituent bond positions are freely in the scope without the chemical problem.But, work as A ¹, A ², A ³And A ⁴During for Isosorbide-5-Nitrae-Ya benzene, X ³, X ⁴, X ⁵And X ⁶It or not singly-bound.

Below expression is by the better example of the represented diamines of formula (2).

Among these diamines, with regard to the viewpoint of liquid crystal orienting film being given higher VHR and inhibition trace phenomenon, be more preferably by formula (2-6)～formula (2-24), formula (2-36), formula (2-42), formula (2-43) or formula (2-48)～represented diamines of formula (2-52), and then be more preferably by formula (2-6), formula (2-11), formula (2-12), formula (2-13), formula (2-17), formula (2-22), formula (2-23), formula (2-24), or the represented diamines of formula (2-49).

The usage ratio of the diamines of the described formula (2) among the present invention can be according to as the regiospecific of target, electrical property and selected arbitrarily.Yet, if the usage ratio of these diamines is larger, liquid crystal liquid crystal property can descend so, so the usage ratio of these diamines is preferably the scope of the 0mol%～30mol% (molar percentage) in synthesizing polyamides employed total diamines amount of when acid, is more preferably 0mol%～10mol%.

Other examples that can be used for preferably making the diamines that does not have photosensitive group of polyamic acid are by formula (3) or the represented diamines with side-chain radical of formula (4).

In formula (3), X ¹And X ²Independent for singly-bound ,-O-,-COO-,-OCO-,-NH-,-CONH-or carbon number are 1～12 alkylidene group; G ¹And G ²Independent for singly-bound or comprise that to be selected from carbon number be that 6～12 aromatic ring and carbon number are the divalent group of 1～3 rings in 3～12 the ester ring type ring; R ⁶Expression hydrogen, fluorine ,-CN ,-OH, carbon number are that 1～30 alkyl, carbon number are that 1～30 fluorinated alkyl or carbon number are 1～30 alkoxyl group.But, work as X ¹, G ¹, X ²And G ²When all being singly-bound, R ⁶That carbon number is that 3～30 alkyl, carbon number are that 3～30 fluorinated alkyl or carbon number are 3～30 alkoxyl group; Work as G ²Singly-bound and X ²Neither when singly-bound neither alkylidene group, R ⁶It is hydrogen or alkyl; And, work as G ¹And G ²When being singly-bound, X ¹, X ²And R ⁶The total carbon number more than or equal to 3.

In described formula (3), 2 amidos are binding on the carbon of phenyl ring, position (meta position) or contraposition (para position) between the bond position relationship of 2 amidos is preferably.And, when with X ¹Bond position when being made as 1, be preferably 2 amidos be binding on respectively 3 with 5 or 2 with 5, particularly preferred be binding on 3 with 5.

In formula (4), R ⁷That hydrogen or carbon number are 1～12 alkyl; Ring B be arbitrarily hydrogen can by carbon number be the Isosorbide-5-Nitrae that replaces of 1～4 alkyl-Ya benzene or arbitrarily hydrogen can be the Isosorbide-5-Nitrae that replaces of 1～4 alkyl-stretch cyclohexyl by carbon number; X ⁰Be that singly-bound or carbon number are 1～5 alkylidene group, and s is 0～3 integer; When s was 2 or 3, a plurality of ring B can all be identical ring, also can be made of a plurality of X at least 2 different rings ⁰Can all be identical group, also can be consisted of by at least 2 different groups; Z ¹And Z ²Independent be singly-bound ,-CH ₂-,-CH ₂CH ₂-or-O-, t1 and t2 independently are 0～3 integer; When t1 is 2 or 3, a plurality of Z ¹Can all be identical group, also can be consisted of by at least 2 different groups; When t2 is 2 or 3, a plurality of Z ²Can all be identical group, also can be consisted of by at least 2 different groups.

Below expression is by the better example of the represented diamines of formula (3).

In formula (3-1)～formula (3-25), R ²⁰Be that carbon number is 1～20 alkyl or alkoxyl group, be preferably carbon number and be 5～16 alkyl.R ²¹Be that carbon number is 1～20 alkyl or alkoxyl group, be preferably carbon number and be 3～10 alkyl.R ²²Be that carbon number is 4～20 alkyl, be preferably carbon number and be 6～16 alkyl.R ²³Be that carbon number is 6～20 alkyl, be preferably carbon number and be 8～20 alkyl.R ²⁴Be that carbon number is 3～20 alkyl or alkoxyl group, be preferably carbon number and be 5～12 alkyl.R ²⁵Be that carbon number is 1～20 alkyl or alkoxyl group, be preferably carbon number and be 3～10 alkyl.

Among these diamines, better example is by formula (3-1), formula (3-2), formula (3-4), formula (3-5) and formula (3-6) represented diamines separately, and then better example is by formula (3-1) and formula (3-2) represented diamines separately.

Below expression is by the better example of the represented diamines of formula (4).

In formula (4-1)～formula (4-16), R ²⁶Be that hydrogen or carbon number are 1～12 alkyl or alkoxyl group, be preferably carbon number and be 4～7 alkyl.

The usage ratio of the described formula (3) among the present invention or the diamines with side-chain radical of formula (4) can be according to as regiospecific, electrical property or the tilt angle of target and selected arbitrarily.Especially in order to show the tilt angle more than or equal to 2 degree, the usage ratio that is preferably these diamines is made as the 1mol%～50mol% in the employed diamines total amount when making polyamic acid, is more preferably and is made as 5mol%～30mol%.Yet if the usage ratio of the diamines with side-chain radical of described formula (3) or (4) is larger, liquid crystal liquid crystal property can descend so, therefore is preferably and is made as necessary inferior limit.

Among the diamines with side-chain radical of described formula (3) or formula (4), for the liquid crystal liquid crystal property that keeps alignment film of the present invention to have, be preferably the diamines of selecting type (3-5), formula (3-6) or formula (3-10).

In the present invention, except described diamines, also can use at least a of siloxane-based diamines.As the better example of this siloxane-based diamines, can enumerate by the represented diamines of formula (15).

In formula (15), R ³⁰And R ³¹Independent of carbon number is 1～3 alkyl or phenyl respectively, R ³²Be that carbon number is 1～6 alkylidene group, inferior benzene or the inferior benzene that replaces through alkyl, y is 1～10 integer.

As the concrete example by the represented diamines of formula (15), can enumerate following compound or polymkeric substance.

In these formulas, Me is methyl, and the molecular weight of the polymkeric substance of formula (15-2) is 850～3000.

In order to show described effect and to prevent the deterioration of other characteristics, the addition of these siloxane-based diamines as the total amount of the diamines of raw material, is preferably 0.5mol%～30mol% when making polyamic acid, is more preferably 1mol%～10mol%.

According to the characteristic that requires of alignment film, when making polyamic acid, can use expression voltage retention (VHR) higher and be difficult to produce the well-known acid anhydrides of the so-called electrical property excellence of the characteristic such as trace.

As the acid anhydrides of the manufacturing raw material of polyamic acid, can from well-known compound, unrestrictedly select.Acid anhydrides can be the acid anhydrides that belongs to any one cohort in the acid anhydrides of the acid anhydrides of fragrant family (comprising assorted aromatic ring) and fatty family (comprising heterocycle system).Polyimide or polyamic acid are preferably the oxygen of ester bond with the decrease reason that does not comprise the electrical property that becomes easily liquid crystal display device or ehter bond etc. or the structure of sulphur.Therefore, acid anhydrides also is to have the structure that does not comprise oxygen or sulphur preferably.Yet, even if can not cause amount in the dysgenic scope to electrical property if having this kind structure, so without any problem yet.

Acid anhydrides is to be represented by formula (20).

R in the formula (20) ⁴⁰Better example be by formula (21)～represented quaternary groups of formula (29).

G ³That singly-bound, carbon number are 1～12 alkylidene group, Isosorbide-5-Nitrae-Ya benzene or Isosorbide-5-Nitrae-stretch cyclohexyl, X ⁷Independent be singly-bound or-CH ₂-.

R ⁴¹, R ⁴², R ⁴³And R ⁴⁴Independent is hydrogen, methyl, ethyl or phenyl.

Ring D ¹Cyclohexane ring or phenyl ring.

G ⁴Be singly-bound ,-CH ₂-,-CH ₂CH ₂-,-O-,-CO-,-S-,-C (CH ₃) ₂-or-C (CF ₃) ₂-, ring D ²Independent is cyclohexane ring or phenyl ring.

R ⁴⁵Hydrogen or methyl.

X ⁸Independent be singly-bound or-CH ₂-, v is 1 or 2.

X ⁶Be singly-bound or-CH ₂-.

R ⁴⁶Hydrogen, methyl, ethyl or phenyl, ring D ³Cyclohexane ring or phenyl ring.

W1 and w2 independently are 0 or 1.

The concrete example that below represents described acid anhydrides.

In these acid anhydrides, in order to keep the liquid crystal liquid crystal property of polyamic acid, be preferably the compound of use formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21) or formula (A-37).And, with regard to the viewpoint of the light orientation ability that improves alignment film, be preferably the compound of use formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-28), formula (A-30), formula (A-37) or formula (A-40), particularly preferred is the compound of use formula (A-1), formula (A-12), formula (A-14) or formula (A-18).In addition, with regard to the VHR that improves liquid crystal orienting film or alleviate with regard to the painted viewpoint, be preferably use formula (A-14), formula (A-18), formula (A-19), formula (A-20), formula (A-21), formula (A-28), formula (A-29), formula (A-30), formula (A-32), formula (A-39), formula (A-40), formula (A-41), formula (A-43), or the compound of formula (A-44), particularly preferred is use formula (A-14), formula (A-18), formula (A-21), or the compound of formula (A-44).Acid anhydrides is not limited to these compounds, also can use other well-known compounds in reaching the scope of the object of the invention.And these acid anhydrides can use separately, perhaps two or more compound combination can be used.

In the present invention, by described diamines and acid anhydrides appropriate combination are reacted to make polyamic acid.The 1st good example of this polyamic acid is the polyamic acid that obtains in the following way, that is, at least a and acid anhydrides as the compound (I-1) with diamines of photosensitive group～compound (I-3), compound (II-1)～compound (II-3), compound (III-1), compound (IV-1)～compound (IV-3), compound (V-1) and compound (VI-1)～compound (VI-7) is reacted.

This moment, the better example of employed acid anhydrides was the acid anhydrides that is selected from compound (A-1), compound (A-2), compound (A-12), compound (A-14), compound (A-18), compound (A-20), compound (A-21), compound (A-37), compound (VII-4), compound (VII-5), compound (VIII-7) and the compound (VIII-8).And particularly preferred is compound (VII-4) and compound (VII-5).

Herein, R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group.And, R ⁵Be preferably carbon number and be 6～12 alkylidene group, that is-C ₆H ₁₂The C of-～- ₁₂H ₂₄-in any one.

The 2nd good example of polyamic acid is the polyamic acid that obtains in the following way, that is, at least a and diamines by the represented acid anhydrides of formula (IV-4) and formula (VI-8) as described acid anhydrides with photosensitive group is reacted.

This moment, the better example of employed diamines was the diamines that selects in the represented compound of free style (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6).

H ₂N-R ⁴-NH ₂ (VII-1)

Herein, R ⁴Be that carbon number is 6～20 alkylidene group, carbon number is preferably 6～12.R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group.And, R ⁵Be preferably-C ₆H ₁₂The C of-～- ₁₂H ₂₄-in any one.

The 3rd good example of polyamic acid is the polyamic acid that obtains in the following way, that is, make and be selected from described compound (I-1)～compound (I-3), compound (II-1)～compound (II-3), compound (III-1), compound (IV-1)～compound (IV-3), at least a at least a mixture and the acid anhydrides with being selected from the diamines in described compound (VII-1)～compound (VII-3) and compound (the VIII-1)～compound (VIII-6) of the diamines in compound (V-1) and compound (VI-1)～compound (VI-7) reacts.The better example of this acid anhydrides is the acid anhydrides that is selected from described compound (A-1), compound (A-2), compound (A-12), compound (A-14), compound (A-18), compound (A-20), compound (A-21), compound (A-37), compound (VII-4), compound (VII-5), compound (VIII-7) and the compound (VIII-8).And, when diamines that selection from compound (VII-1)～compound (VII-3) can be made up with the diamines with photosensitive group, particularly preferred acid anhydrides is compound (VIII-7) or compound (VIII-8), when diamines that selection from compound (VIII-1)～compound (VIII-6) can be made up with the diamines with photosensitive group, particularly preferred acid anhydrides is compound (VII-4) or compound (VII-5).

The 4th good example of polyamic acid is the polyamic acid that obtains in the following way, that is, described at least a mixture and diamines at least a and by the represented acid anhydrides of formula (VII-4), formula (VII-5), formula (VIII-7) and formula (VIII-8) by the represented acid anhydrides with photosensitive group of formula (IV-4) and formula (VI-8) reacted.The better example of this diamines be selected from described by the diamines in the represented compound of formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6).

(the R in these formulas ⁵Implication as mentioned above)

The 5th good example of polyamic acid is the polyamic acid that obtains in the following way, that is, make and describedly describedly reacted by at least a mixture and acid anhydrides in the represented diamines of formula (2)～formula (4) with being selected from by at least a of the represented diamines with photosensitive group of formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), formula (V-1) and formula (VI-1)～formula (VI-7).The better example of this acid anhydrides be selected from described by the acid anhydrides in the represented compound of formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and formula (VIII-8).And this acid anhydrides is particularly preferred to be compound (VII-4) and compound (VII-5).

The 6th good example of polyamic acid is the polyamic acid that obtains in the following way, that is, make described by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a, described by at least a of the represented diamines of formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6) and be selected from and describedly reacted by at least a mixture and acid anhydrides in the represented diamines of formula (2)～formula (4).The better example of this acid anhydrides be selected from described by the acid anhydrides in the represented compound of formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and formula (VIII-8).

The 7th good example of polyamic acid be by make by at least a of the represented diamines of formula (VII-1)～formula (VII-3) with by formula (VIII-7) and the represented tetracarboxylic dianhydride of formula (VIII-8) at least a, reacted the polyamic acid that obtains or by making by at least a of the represented diamines of formula (VIII-1)～formula (VIII-6) and at least a polyamic acid that obtains that reacts by formula (VII-4) and the represented tetracarboxylic dianhydride of formula (VII-5).

H ₂N-R ⁴-NH ₂ (VII-1)

(the R in these formulas ⁴And R ⁵Implication for as mentioned above).

And, the better example of orientation agent of the present invention is the orientation agent that contains the polyimide that a kind of polyamic acid of being selected from described 7 kinds of better polyamic acids or the dehydration reaction by this polyamic acid obtain, but selected polyamic acid also can be two or more.In addition, if do not hinder in the scope of effect of the present invention, orientation agent so of the present invention also can contain the general polyamic acid except described example except comprising described 7 kinds of polyamic acids at least a.That is, in the present invention, as long as satisfy the condition that has the film of liquid crystal temperature range between 100 ℃ to 300 ℃ that is formed on, just can be except described polyamic acid, and maybe can't be formed on polyamic acid of the film that has liquid crystal temperature range between 100 ℃ to 300 ℃ etc. with the polyamic acid that does not have photosensitive group on the main chain.When the polyamic acid that uses this kind except described example, the ratio of this polyamic acid is preferably less than 20wt% less than the 50wt% in the film forming component total amount in the orientation agent.

Just regulate alignment film for regard to the viewpoint of the adhesion of glass substrate, orientation agent of the present invention also can further include organic silicon compound.The example of silicoorganic compound is aminopropyl trimethoxysilane (aminopropyltrimethoxysilane), aminopropyl triethoxysilane, vinyltrimethoxy silane, N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, vinyltriethoxysilane, the 3-methacryloxypropyl trimethoxy silane, the 3-glycidoxypropyltrimewasxysilane, 3-glycidoxypropyl methyl dimethoxysilane, 2-(3,4-epoxy group(ing) cyclohexyl) silane coupling agent such as ethyl trimethoxy silane, and dimethyl polysiloxane (dimethylpolysiloxane), polydimethylsiloxane, the silicone oil such as polydiphenylsiloxane (silicone oil).

The adding proportion of these silicoorganic compound in the orientation agent is so long as can obtain the scope of effect of the present invention, and there is no particular restriction so.Yet, if add a large amount of described silicoorganic compound, have so the bad situation of orientation that produces liquid crystal when making alignment film.Therefore, when being added with organic silicon compound, the total amount of the relative concentration of these silicoorganic compound contained component of polymer in the orientation agent is preferably the scope of 0.01wt%～5wt%, and particularly preferred is the scope of 0.1wt%～3wt%.

Deteriorated or for the caused deteriorated viewpoint of environment with regard to preventing the characteristic temporal evolution, orientation agent of the present invention also can further contain the compound with the functional group who reacts with the carboxylic acid residues of polyamic acid more than 2 or 2, i.e. so-called linking agent.As the example of this kind linking agent, can enumerate: such as multi-functional epoxy's compound of disclosing in No. 3049699 communique of Japanese Patent, Japanese Patent Laid-Open 2005-275360 communique, the Japanese patent laid-open 10-212484 communique etc., isocyanic ester (isocyanate) material etc.

And, react and become cancellated polymkeric substance such as linking agent itself, thereby the linking agent that improves the film toughness of polyamic acid or polyimide also can be used for the purpose identical with described purpose.As this kind linking agent, can enumerate: such as multifunctional Vinyl Ether (vinyl ether), maleimide (maleimide) or diallyl Na Dike imide (bis-allyl-nadi-imide) derivative etc. that disclose in Japanese patent laid-open 10-310608 communique, the Japanese Patent Laid-Open 2004-341030 communique etc.The ratio of these linking agents is preferably 0wt%～50wt% with respect to the total amount of component of polymer, is more preferably 0wt%～30wt%.

Orientation agent of the present invention contains the solvent of the ability with dissolving polyamic acid.Described solvent widely be included in the manufacturing of polyamic acid or derivatives thereof or use in the solvent that generally uses, can suitably select according to application target.If enumerate these solvents, so as follows.

As for polyamic acid, being the example of the non-proton property polar organic solvent of good solvent (good solvent), can enumerate: METHYLPYRROLIDONE (N-Methyl-2-pyrrolidinone, NMP), dimethyl-imidazolinone (dimethylimidazolidinone), N-methyl caprolactam (N-Methyl caprolactam), N-methyl propanamide (N-methyl propionamide), N, N-N,N-DIMETHYLACETAMIDE (N, N-dimethylacetamide), dimethyl sulfoxide (DMSO) (dimethyl sulfoxide), N, dinethylformamide (N, N-dimethyl formamide, DMF), N, N-diethylformamide (N, N-diethyl formamide), N, N-diethyl acetamide (N, N-diethylacetamide, DEAc), and the lactone (lactone) such as gamma-butyrolactone (γ-butyrolactone, GBL).

As except described solvent to improve coating etc. as the example of other solvents of purpose, can enumerate: lactic acid alkyl ester (alkyl lactate), 3-methyl-3-methoxybutanol (3-methyl-3-methoxybutanol), tetraline (tetralin), isophorone (isophorone), ethylene glycol monobutyl ether (ethylene glycol monobutyl ether, the ethylene glycol monoalkyl ether such as BCS), the Diethylene Glycol monoalky lethers such as diethylene glycol monoethyl ether, ethylene glycol monoalkyl ether acetate and ethyleneglycol monophenylether acetic ester, the triethylene glycol monoalky lether, the propylene-glycol monoalky lethers such as propylene glycol monobutyl ether, the dialkyl malonates such as diethyl malonate, the dipropylene glycol monoalky lethers such as dipropylene glycol monomethyl ether, and the ester cpds of these glycol monoethers etc.Among these compounds, can in described solvent, use particularly well NMP, dimethyl-imidazolinone, GBL, BCS, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether etc.

Orientation agent of the present invention also can be according to required and further contain various additives.For example, when expectation further improves coating, the tensio-active agent according to described purpose can be contained in right amount, when needs further improve antistatic effect, static inhibitor can be contained in right amount.

The concentration of the polyamic acid in the orientation agent of the present invention is preferably 0.1wt%～40wt%.When being coated on this orientation agent on the substrate, in order to adjust thickness, sometimes must carry out diluting by solvent in advance the operation of contained polyamic acid.

Be not particularly limited for the solid component concentration in the orientation agent of the present invention, as long as select optimum value according to following various coating methods.Usually, the inequality in order to suppress to be coated with or hole (pinhole) etc., solid component concentration is preferably 0.1wt%～30wt% with respect to varnish (varnish) weight, is more preferably 1wt%～10wt%.

Alignment film of the present invention is to obtain in the following way,, gives anisotropy by friction or rayed to described orientation agent is coated on the film that obtains on the substrate that is, the anisotropy of film is increased till then being heated to the liquid crystal temperature range of film.

With regard to the viewpoint that shows sufficient regiospecific this moment, be preferably according to following order manufacturing:

(1) by hairbrush coating method, pickling process, method of spin coating, spray method, print process etc., described varnish is coated on the substrate;

(2) 50 ℃～120 ℃, be preferably formed film on 80 ℃～100 ℃ lower heated substrates, and make solvent evaporation;

(3) described film irradiation light is made polyamic acid orientation in the described film;

(4) 150 ℃～300 ℃, be preferably 180 ℃～250 ℃ lower heating and make the described film of polyamic acid orientation, and make described film imidization.

In addition, when wanting in the liquid crystal display device of use alignment film, to show the tilt angle of regulation, can carry out by the following method, namely in the irradiation light time, from angle arbitrarily substrate is shone rectilinearly polarized light, perhaps will to substrate carry out from the rectilinearly polarized light irradiation of vertical direction with made up from the arbitrarily non-polarized light irradiation of angle.

In the manufacturing of alignment film of the present invention, when the orientation of described polyamic acid, use rectilinearly polarized light.The polyamic acid main chain is because of irradiation orientation on the direction vertical with the direction of polarized light of rectilinearly polarized light of rectilinearly polarized light.Described rectilinearly polarized light is not particularly limited so so long as can make the light of the polyamic acid orientation in the described film.Alignment film of the present invention can make the film orientation by low-energy rayed.The irradiation dose of the rectilinearly polarized light during therefore, the light orientation of described polyamic acid is processed is preferably 0.5J/cm ²～10J/cm ²And the wavelength of rectilinearly polarized light is preferably 300nm～400nm.The irradiating angle for the film surface of rectilinearly polarized light is not particularly limited, but when the stronger orientation restraint wanting to show for liquid crystal, and with regard to the viewpoint that shortens the orientation treatment time, irradiating angle is preferably as far as possible and the film Surface Vertical.

And in the manufacturing of alignment film of the present invention, the light that shines described film when wanting to show tilt angle both can be that polarized light can be non-polarized light.The irradiation dose that shines the light of described film when wanting to show tilt angle is preferably 0.5J/cm ²～10J/cm ², this light wavelength is preferably 300nm～400nm.The irradiating angle for described film surface that shines the light of described film when wanting to show tilt angle is not particularly limited, but with regard to the viewpoint that shortens the orientation treatment time, is preferably 30 degree～60 degree.

Alignment film of the present invention is characterised in that the anisotropy with king-sized orientation.The anisotropic size of this kind can be estimated by the method for the use polarized light infrared rays (Infra-red, IR) that discloses among Japanese Patent Laid-Open 2005-275364 etc.And, shown in following examples, also can estimate by the method for utilizing ellipsometry (ellipsometry).When alignment film of the present invention is used alignment film as liquid-crystal composition, it is generally acknowledged that the anisotropic material with larger film has larger orientation restraint for liquid-crystal composition.

The orientation purposes of the liquid-crystal composition that alignment film of the present invention is used except liquid-crystal display, can be used for the orientation of control optical compensation material or other all liquid crystal materials.And, because alignment film of the present invention has larger anisotropy, therefore can be used for separately the optical compensation material applications.

The invention provides a kind of liquid crystal display device, this liquid crystal display device comprise subtend configuration a pair of substrate, one or both formed electrode of the face of described a pair of substrate subtend separately, the formed liquid crystal orienting film of face of described a pair of substrate subtend separately and between described a pair of substrate formed liquid crystal layer, described liquid crystal orienting film is alignment film of the present invention.

Described electrode is so long as at the formed electrode of the one side of substrate, be not particularly limited so.This kind electrode for example can be enumerated the vapor-deposited film of tin indium oxide (Indium Tin Oxide, ITO) or metal etc.And electrode also can be formed on whole of one side of substrate, for example can form patterned required shape.The described required shape of electrode is such as enumerating interdigitated electrode structure or broached-tooth design etc.Electrode can be formed on the substrate in a pair of substrate, also can be formed on two substrates.The formation form of electrode is according to the kind of liquid crystal display device and different, and for example when IPS type liquid crystal display device, configured electrodes on the one of described a pair of substrate when other liquid crystal display device, is configured in described a pair of substrate on both with electrode.Form described liquid crystal orienting film at described substrate or electrode.

Described liquid crystal layer is with by the form of the described a pair of substrate clamping liquid-crystal composition of the face institute subtend that is formed with liquid crystal orienting film and form.When forming liquid crystal layer, can use as required micropartical or resin sheet etc. between described a pair of substrate and form the spacing piece (spacer) of appropriate intervals.Be not particularly limited for described liquid-crystal composition, can use well-known liquid-crystal composition.

When alignment film of the present invention forms liquid crystal display device as liquid crystal orienting film, with respect to well-known all liquid-crystal compositions, can improve the characteristic of liquid crystal display device, but adopt the alignment film of the present invention of described method manufacturing, especially to the orientation defective of the large view display that is difficult to carry out friction treatment to improve effect larger.The large view display of this kind is to drive control by TFT.And employed liquid-crystal composition discloses in No. 3086228 communique of Japanese Patent, No. 2635435 communiques of Japanese Patent, the special flat 5-501735 communique of table of Japanese Patent and Japanese patent laid-open 9-255956 communique to some extent in this kind TFT type liquid crystal display device.Therefore, alignment film of the present invention be preferably with these communiques in the liquid-crystal composition that discloses be used in combination.

Tilt angle in the liquid crystal display device of the present invention can use for example liquid crystal characteristic evaluating apparatus OMS-CA3 type of central smart machine manufacturing, and employing Journal of Applied Physics, Vol.48, No.5, the crystal rotation method that p.1783-1792 discloses in (1977) (Crystal rotationmethod) is measured.

Liquid crystal display device of the present invention is more excellent aspect the electrical property relevant with the reliability of liquid crystal display device.As this kind electrical property, can enumerate voltage retention and ion density (iondensity).

Voltage retention (VHR) is that the voltage that is applied to liquid crystal display device during the frame period (frame period) remains in the ratio in the liquid crystal display device, and this voltage retention represents the display characteristic of liquid crystal display device.With regard to preventing from showing bad viewpoint, liquid crystal display device of the present invention is preferably and uses 5V and frequency to be the square wave of 30Hz, and the voltage retention of measuring under 60 ℃ temperature condition is more than or equal to 90.0%, perhaps use 5V and frequency to be the square wave of 0.3Hz, and the voltage retention of measuring under 60 ℃ temperature condition is more than or equal to 85.0%.

Ion density be produce when liquid crystal display device is applied voltage except by the transient current the caused electric current of liquid crystal drive (transient current), this ion density represents the size of the concentration of ionic impurity contained in the liquid crystal in the liquid crystal display device.With regard to the viewpoint of the trace that prevents liquid crystal display device, the ion density of liquid crystal display device of the present invention is preferably less than or equal to 500pC.

[embodiment]

Below, the present invention will be described by embodiment and comparative example, but the present invention is not limited to these embodiment.Pyromellitic acid anhydride (pyromellitic anhydride, PMDA, compound (A-1)), 1,2,3,4-tetramethylene tetracarboxylic acid (1,2,3,4-cyclobutanetet racarboxylic acid, CBTA, compound (A-14)) and compound (2-13) be to be used for experiment by recrystallize after with commercially available compound purifying.1,8-octamethylenediamine (1,8-Diaminooctane, DAO, compound (VII-1-1)) is to use after the commercially available product distillation.Compound (II-1), compound (A-21) are respectively according to Japanese Patent JP 5-65530 communique and the clear 58-109479 communique of Japanese Patent Laid-Open and synthesize.Following compound (VII-2-1), compound (VII-2-2) and compound (VII-5-1) are according to Japanese patent laid-open 11-160712 communique and Bulletin de la Societe Chimique de France, 9-10, Pr.2, the method that discloses in 2195 (1975) and synthesizing.Compound (VIII-5) and compound (VIII-6) are commercially available product not to be carried out purifying and it is directly used in the experiment.Compound (VIII-8) is to be used for experiment by ethanol after with the commercially available product recrystallize.Compound (2-22) and compound (3-5-1) are to adopt and Journal of Polymer Science Part A:PolymerChemistry, 30 (6), 1099 (1992), the method that the method that discloses in the Japanese Patent Laid-Open 2002-162630 communique is identical is synthetic.Compound (A-21) is to synthesize according to the clear 58-109479 communique of Japanese Patent Laid-Open.The preparation of polymkeric substance is to carry out in nitrogen gas stream.

Rayed is to use to contain the 250W high pressure mercury vapour lamp that flourish hall is sold in the well, and illumination wavelength is the ultraviolet ray about 300nm～380nm.Irradiation is to carry out in room temperature, air.

The evaluation assessment that below represents employed liquid crystal display device among the embodiment.

The delay of＜alignment film (retardation) and determining film thickness 〉

Use elliptic polarization spectrometer (spectroscopic ellipsometer) M-2000U (J.A.Woollam Co.Inc. manufacturing) to obtain.In the present embodiment, the orientation degree of the length of delay of film and main polymer chain increases pro rata.That is the film with larger length of delay has larger orientation degree.

The mensuration of＜ultraviolet-visible (ultraviolet-visible spectrum, UV-Vis) spectrum 〉

Use UV-Vis spectrometer (Japanese light splitting V-660), take the glass substrate that is not formed with alignment film as measuring with reference to (reference).

＜voltage retention 〉

Adopt the method that discloses in " water island etc., the 14th liquid crystal discussion preliminary draft collection p78 (1988) " to measure.Mensuration is unit (cell) to be applied wave height carry out for the square wave of ± 4.5V.Mensuration is to carry out under 60 ℃.This value is the index that the voltage that applies of expression with which kind of degree was maintained after the frame period, if this value reaches 100%, represents that so whole electric charges all are maintained.

Ionic weight in the＜liquid crystal is measured (ion density) 〉

According to the method that discloses in the Applied Physics, the 65th volume, No. 10,1065 (1996), liquid crystal physical property measurement system 6254 types that use Toyo Corporation company to make are measured.Frequency of utilization is the choppy sea of 0.01Hz, measures under 60 ℃ temperature with the voltage range of ± 10V.If ion density is larger, produce by unfavorable conditions such as the caused traces of ionic impurity so easily.That is ion density is the physics value that becomes the index of prediction trace generation.

＜viscosity 〉

Use rotational viscosimeter (TV-22L, eastern machine industry (TOKI SANGYO) company makes) to measure.

＜weight average molecular weight (weight-average molecular weight, Mw) 〉

The weight average molecular weight of the polyamic acid in the crystal aligning agent (Mw) is utilized gel permeation chromatograph (Gel Permeation chromatography, GPC), and use that 0.6wt%'s contain phosphoric acid DMF as dissolution fluid, under 50 ℃ tubing string temperature, polystyrene is measured as standardized solution.Tubing string uses Shodex GF-7M HQ (clear and electrician company makes).

The affirmation of＜high molecule liquid crystal 〉

Under 230 ℃ to the film (the about 70nm of thickness) of film forming on substrate calcining 10 minutes after, utilize polarization microscope to observe.In addition, heat-up rate is made as 3 ℃/min.

＜glass tansition temperature 〉

Use differential scanning calorimetric measurement device (Differential Scanning Calorimet ry, DSC) to measure.Heat-up rate is made as 8 ℃/min.

The black level of＜unit (black level) is confirmed 〉

Unit to made carries out polarized light microscope observing, and judges according to following table.

[synthesis example 1]

Synthesizing of＜compound (VII-2-3) 〉

To synthesize with the Compound Phase mode together of (VII-2-2).Fusing point: 98.0 ℃～99.2 ℃.

[synthesis example 2]

Synthesizing of＜compound (VII-4-1) 〉

With 4-phthalate bromine diethyl ester (50g, 166mmol), 1, hot diine (the 8.7g of 7-, 82mmol), triphenylphosphine palladium chloride (II) (290mg, 0.41mmol) and cupric iodide (158mmol, 0.83mmol) mixture under nitrogen gas stream, in triethylamine (200ml), refluxed 4 hours.After question response finishes, add toluene (500ml) and pure water (500ml) and extract.After cleaning once with pure water (300ml) organic layer, utilize anhydrous magnesium sulfate to carry out drying.Filter and solvent is removed in underpressure distillation, thereby obtain Isosorbide-5-Nitrae-two (3,4-dicarboxyl phenyl) ethynyl butane tetra-ethyl ester as target compound.Output is 42g, and productive rate is 95%.This compound is purified and be directly used in the next reaction.

1,4-two (3,4-dicarboxyl phenyl) ethynyl butane tetra-ethyl ester (42g, add the palladium-carbon catalyst (Pd/C) of 5wt% 77mmol) (2.1g), then in toluene/ethanol mixed solvent (300ml/300ml), carry out hydrogenation with the hydrogen pressure of 720MPa.After question response finishes, filter and remove catalyzer, and solvent is removed in underpressure distillation.With residue utilization tubing string chromatography (columnchromatography) (silica gel/toluene: vinyl acetic monomer=10: 1v/v) carry out purifying, thereby obtain as 1 of target compound, two (3,4-dicarboxyl phenyl) the octane tetra-ethyl esters of 8-.Output is 43g, and productive rate is 100%.

Two (3,4-dicarboxyl phenyl) the octane tetra-ethyl esters (43g, 77mmol) of 1,8-are dissolved in the ethanol (250ml), and add 5.7% aqueous sodium hydroxide solution (250ml), then refluxed 2 hours.Behind the question response, solvent is removed in underpressure distillation, then adds concentrated hydrochloric acid until the pH value reaches till 1.Filter after the throw out that produces, throw out is cleaned 3 times with pure water (200ml).Drying under reduced pressure is carried out in the crystallization that obtains, obtain thus two (3, the 4-dicarboxyl phenyl) octanes of 1,8-.Output is 31g, and productive rate is 90%.

In two (3, the 4-dicarboxyl phenyl) octanes (10g, 23mmol) of 1,8-, add acetic anhydride (50ml), then refluxed 2 hours.Underpressure distillation is removed after the acetic anhydride, adds hexanaphthene (50ml) in residuum, filters the throw out that produces.Drying under reduced pressure is carried out in the crystallization that obtains, obtain thus compound (VII-4-1).Output is 9.2g, and productive rate is 97%.Fusing point: 109.7～111.2 ℃.

¹H NMR(500Hz，CDCl ₃)；δ(ppm)7.92(d，4H，J＝7.80Hz)，7.70(d，4H，J＝8.1Hz)，2.82(t，4H，J＝7.65Hz)，1.3-1.7(m，12H).

[synthesis example 3]

The preparation of＜polyamide acid varnish A 〉

With compound (II-1) (0.1818g, 0.7827mmol) be dissolved in the METHYLPYRROLIDONE (NMP, 3.0g), one side is with compound (VII-4-1) (0.3182g, 0.7829mmol) remaining in room temperature or below the room temperature, one side is added.After stirring an evening, add NMP (3.5g) and ethylene glycol monobutyl ether (BSC, 3.0g) and preparation varnish A.The viscosity of varnish A is 49.8mPas.The weight average molecular weight of the polyamic acid of this varnish is 74,000, has mesomorphic phase in 200 ℃～300 ℃ scope.

[synthesis example 4～14]

The preparation of＜polyamide acid varnish B～L 〉

Press the raw material shown in the table 1 and form, adopt the method identical with synthesis example 1 to prepare the varnish B of polyamic acid～varnish L, and measure physical property in the mode identical with synthesis example 1.Expression mol% in the bracket.In addition, according to described assay method these all varnish are carried out the affirmation of mesomorphic phase, there is mesomorphic phase in the result in 170 ℃～250 ℃ scope.

＜table 1 〉

Synthesis example No.	The varnish title	Diamines	Acid anhydrides	Viscosity (mPa.s)	Weight average molecular weight
						3	A	II-1	VII-4-1	49.8	74,000
4	B	VI-1	VII-4-1	25.8	48,000
						5	C	VII-1-1(80) I-1(20)	VIII-8	33.3	55,000
6	D	VII-1-1(80) VI-1(20)	VIII-8	28.3	50,000
						7	E	VII-1-1(80) VI-1(20)	VIII-8(90) A-14(10)	37.9	68,000
8	F	II-1(40) VI-1(40) (2-22)(20)	VII-4-1	30.8	51,000
						9	G	VII-2	VIII-8	30.4	60,000
10	H	VIII-1	VII-4-1	27.6	48,000
						11	I	VIII-5	VII-4-1	34.2	54,000
12	J	VIII-6	VII-4-1	37.1	62,000
						13	K	VIII-6	VII-5-1	19.2	28,000
14	L	VI-1	VII-4-1(90) A-21(10)	28.7	49,000

[embodiment 1]

In sample bottle, take by weighing the varnish A of 1.0g, and add NMP/BC=1/1 (weight ratio) and reach 1.67g.On transparent glass substrate, drip the polyamic acid solution of this about 3wt%, and adopt method of spin coating to be coated with (2,000rpm, 15 seconds).After to be coated, 80 ℃ of lower heated substrates 3 minutes, make after the solvent evaporation, being situated between, (365nm and energy are about 1.3J/cm every polarization plate irradiation rectilinearly polarized light ²).In baking oven (oven), with 210 ℃ the substrate after the rayed is carried out 15 minutes heat treated, thereby obtain the alignment film A that thickness is about 100nm.Measure the delay of this alignment film A, the result is 12.9nm.

[embodiment 2～embodiment 6]

Use the varnish shown in the table 2, obtain alignment film B～alignment film F in the mode identical with embodiment 1.Represent in the lump measuring the result of delay gained and the result of embodiment 1.

＜table 2 〉

Embodiment No.	The varnish title	The alignment film title	Postpone (nm)
				1 2 3 4 5 6	A B C D E F	A B C D E F	12.9 27.8 13.7 7.9 5.6 24.0

[embodiment 7]

Use respectively mixes respectively the varnish M that 0.5g forms with varnish A and varnish B and replaces varnish A, in addition, makes alignment film M according to the method identical with embodiment 1.The length of delay of this alignment film M is 30.5nm.

[comparative example 1]

With compound (II-1) (2.6432g, 11.38mmol) be dissolved among the NMP (35.0g), one side is with PMDA (1.2410g, 5.690mmol) and CBTA (1.1158g, 5.690mmol) remaining in room temperature or below the room temperature, one side is added.After at room temperature stirring an evening, add NMP (35g) and BSC (25g).The viscosity of this solution is 120mPas.60 ℃ of lower stir abouts 4 hours, be the varnish N of 28.0mPas thereby obtain viscosity with this solution.The weight average molecular weight of the polyamic acid of this varnish is 37,000, and glass tansition temperature (Tg) is above 300 ℃.

Use varnish N, obtain alignment film N in the mode identical with embodiment 1, and measure the delay of this alignment film N.The result is 0.4nm.

[comparative example 2]

Use compound (VI-1) to replace compound (II-1), in addition, obtain viscosity as the varnish P of 34.0mPas in the mode identical with comparative example 1.The weight average molecular weight of the polyamic acid of this varnish is 54,000, and glass tansition temperature (Tg) is above 300 ℃.

Use varnish P, obtain alignment film P in the mode identical with embodiment 1, and measure the delay of this alignment film P.The result is 0.8nm.

If embodiment and comparative example 1 and comparative example 2 are compared, use so as can be known alignment film of the present invention that polymkeric substance of the present invention obtains than the alignment film by the polymkeric substance made that does not have liquid crystal liquid crystal property, even if with less irradiation energy, also has very large length of delay.

[embodiment 8]

Glass substrate replaced in one side be provided with the transparent glass substrate of ITO electrode, in addition, obtain the alignment film A that thickness is about 100nm in the mode identical with embodiment 1.2 substrates that are formed with these alignment films at I TO electrode are fitted as follows: make the direction of polarized light of the rectilinearly polarized light that shines each alignment film parallel, and make be formed with alignment film face relatively to, and then relatively to alignment film between be formed for injecting the space of liquid-crystal composition, thereby be assembled into the liquid crystal cells A (liquid crystal display device) that element thickness is 7 μ m.And, liquid-crystal composition A shown below is injected in these unit.

＜liquid-crystal composition A 〉

By this liquid crystal cells of visual observation A, the result does not observe the mobile orientation of what is called that liquid crystal is arranged along the mobile direction of liquid crystal fully.If polarization microscope is made as crossed polarized light (crossnicol) state, and make liquid crystal cells A rotation, observe so clearly bright attitude (light state) and dark attitude (dark state).The tilt angle of this liquid crystal cells A is 0.0 °.And VHR (voltage retention) is 99.0% (30Hz), 85.0% (0.3Hz), and ion density is 120pC.

And, observe the result of the black level of this liquid crystal cells A, in observed all zones, see less particulate state spot, but still be good black level.

[embodiment 9]

Employed varnish is replaced to varnish B, in addition, make liquid crystal cells B in the mode identical with embodiment 8.The tilt angle of this liquid crystal cells B is 0.0 °.And VHR (voltage retention) is 92.2% (30Hz), 76.3% (0.3Hz), and ion density is 340pC.

And, observe the result of the black level of this liquid crystal cells B, in observed all zones, can't see the particulate state spot fully, this black level is very good black level.

[embodiment 10]

Employed varnish is replaced to varnish F, in addition, make liquid crystal cells F in the mode identical with embodiment 8.The tilt angle of this liquid crystal cells F is 0.0 °.And VHR (voltage retention) is 99.2% (30Hz), 85.3% (0.3Hz), and ion density is 80pC.

Observe the result of the black level of this liquid crystal cells F, can't see the particulate state spot fully in observed all zones, this black level is very good black level.

[embodiment 11]

Employed varnish is replaced to varnish L, in addition, make liquid crystal cells L in the mode identical with embodiment 8.The tilt angle of this liquid crystal cells L is 0.0 °.And VHR (voltage retention) is 99.4% (30Hz), 88.2% (0.3Hz), and ion density is 35pC.

And, observe the result of the black level of this liquid crystal cells L, in observed all zones, can't see the particulate state spot fully, this black level is very good black level.

[embodiment 12]

Employed varnish is replaced to varnish M, in addition, make liquid crystal cells M in the mode identical with embodiment 8.The tilt angle of this liquid crystal cells M is 0.1 °.And VHR (voltage retention) is 99.0% (30Hz), 82.1% (0.3Hz), and ion density is 120pC.

And, observe the result of the black level of this liquid crystal cells M, in observed all zones, can't see the particulate state spot fully, this black level is very good black level.

[comparative example 3]

Employed varnish is replaced to varnish N, in addition, make liquid crystal cells N in the mode identical with embodiment 8.The tilt angle of this liquid crystal cells N is 0.1 °.And VHR (voltage retention) is 99.1% (30Hz), 76.0% (0.3Hz), and ion density is 300pC.

And, observe the result of the black level of this liquid crystal cells N, in observed all zones, see larger particulate state spot, comparing with the liquid crystal display device that uses alignment film of the present invention is the black level of non-constant.

[comparative example 4]

Employed varnish is replaced to varnish P, in addition, make liquid crystal cells P in the mode identical with embodiment 8.The tilt angle of this liquid crystal cells P is 0.0 °.And VHR (voltage retention) is 92.4% (30Hz), 85.3% (0.3Hz), and ion density is 110pC.

And, observe the result of the black level of this liquid crystal cells P, in observed all zones, see larger particulate state spot, comparing with the liquid crystal display device that uses alignment film of the present invention is relatively poor black level.

[embodiment 13]

In the mode identical with embodiment 1, be provided with rotary coating varnish A on the transparent glass substrate of ITO electrode in one side, then with substrate 80 ℃ of lower heating 3 minutes and after making solvent evaporation, in baking oven with 210 ℃ of heating and calcinings that carry out 15 minutes.The polyimide film that the thickness that obtains is about 100nm carries out friction treatment (amount of being pressed into: 0.3mm, platform transfer rate: 60m/s, rotating speed: 1000rpm, friction cloth: YA-18-R (artificial silk)).Then, in ultrapure water, alignment film is carried out after 5 minutes the ultrasonic cleaning, in baking oven with 200 ℃ of dryings 15 minutes.

2 substrates that are formed with these alignment films at the ITO electrode are fitted as follows: make for the frictional direction of each alignment film antiparallel, and make be formed with alignment film face relatively to, and then relatively to alignment film between be formed for injecting the space of liquid-crystal composition, thereby be assembled into the liquid crystal cells Ar that element thickness is 7 μ m.And, described liquid-crystal composition A is injected in these unit.

The tilt angle of this liquid crystal cells Ar is 0.3 °, and VHR (voltage retention) is 98.7% (30Hz), 80.2% (0.3Hz), and ion density is 230pC.And, observe the result of the black level of this liquid crystal cells Ar, in observed all zones, can't see the scar that is produced by friction fully, this black level is and then very good black level.

[embodiment 14]

Use varnish J to replace varnish A, in addition, be assembled into element thickness as the liquid crystal cells Jr of 7 μ m in the mode identical with embodiment 13.The tilt angle of this liquid crystal cells Jr is 0.5 degree, and VHR (voltage retention) is 99.1% (30Hz), 87.5% (0.3Hz), and ion density is 78pC.

And, observe the result of the black level of this liquid crystal cells Jr, in observed all zones, can't see the scar that is produced by friction fully, this black level is and then very good black level.

As mentioned above, when alignment film of the present invention is applied to the alignment film of used for liquid crystal display element, can increase substantially black level.And, as can be known alignment film of the present invention have can be durable sufficient electrical property.

Claims

1. orientation agent, it is to contain at least a polymkeric substance that is selected from the polyimide that polyamic acid and the dehydration reaction by this polyamic acid obtain and the constituent of solvent, it is characterized in that:

The concentration of the polymkeric substance in this constituent is 0.1wt%～40wt%, in this constituent the total amount of contained film forming component as the ratio of the described polymkeric substance of benchmark as 50wt%～100wt%, and can be formed on the film that has liquid crystal temperature range between 100 ℃～300 ℃ by making this constituent film forming, polyamic acid is the polyamic acid that has photosensitive group on the main chain.

2. orientation agent according to claim 1 is characterized in that:

Photosensitive group is at least a by the represented group of formula (I)～formula (VI):

Herein, R ¹, R ²And R ³Independent is aromatic divalent group.

3. orientation agent according to claim 1 is characterized in that:

The polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, makes by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a with by formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and represented at least a of tetracarboxylic dianhydride of formula (VIII-8) react:

4. orientation agent according to claim 1 is characterized in that:

The polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, make by at least a of the represented tetracarboxylic dianhydride with photosensitive group of formula (IV-4) and formula (VI-8) with by formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6)

At least a of represented diamines reacts:

H ₂N-R ⁴-NH ₂ (VII-1)

Herein, R ⁴That carbon number is 6～20 alkylidene group; R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group;

5. orientation agent according to claim 1 is characterized in that:

The polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, makes by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a with by at least a mixture of the represented diamines of formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6) with by formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and represented at least a of tetracarboxylic dianhydride of formula (VIII-8) react:

H ₂N-R ⁴-NH ₂ (VII-1)

6. orientation agent according to claim 1 is characterized in that:

The polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, make by at least a of the represented tetracarboxylic dianhydride with photosensitive group of formula (IV-4) and formula (VI-8) with react by the represented tetracarboxylic dianhydride's of formula (VII-4), formula (VII-5), formula (VIII-7) and formula (VIII-8) at least a mixture with by represented at least a of diamines of formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6):

Herein, R ⁵Be arbitrarily-CH ₂-can by-O-,-NH-,-N (CH ₃)-,-Si (CH ₃) ₂OSi (CH ₃) ₂-or-carbon number that COO-replaces is 6～20 alkylidene group;

H ₂N-R ⁴-NH ₂ (VII-1)

7. orientation agent according to claim 1 is characterized in that:

The polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, makes by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a with select in the represented diamines of free style (2)～formula (4) at least a mixture and by formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and represented at least a of tetracarboxylic dianhydride of formula (VIII-8) react:

Herein, A ¹, A ², A ³And A ⁴Independent of stretching cyclohexyl or inferior benzene; X ³And X ⁴Independent for singly-bound, carbon number be 1～5 alkylidene group or-O-; X ⁵And X ⁶Independent be singly-bound ,-CH ₂-,-CH ₂CH ₂-,-O-or-S-; Y ¹Be-CH ₂-,-C (R ¹¹) (R ¹²)-,-CO-or-SO ₂-, R ¹¹And R ¹²Independent for hydrogen, carbon number be that 1～12 alkyl or carbon number are 1～12 fluorinated alkyl; M1, m2, m3, m4 and n independently represent 0 or 1; And, stretch in cyclohexyl and the inferior benzene described, hydrogen can be 1～4 alkyl or benzyl replacement by carbon number arbitrarily, those substituent bond positions are arbitrarily; But, work as A ¹, A ², A ³And A ⁴When all being Isosorbide-5-Nitrae-Ya benzene, X ³, X ⁴, X ⁵And X ⁶It all not singly-bound;

Herein, X ¹And X ²Be singly-bound ,-O-,-COO-,-OCO-,-NH-,-CONH-or carbon number are 1～12 alkylidene group; G ¹And G ²That to be selected from carbon number be that 6～12 aromatic ring and carbon number are the divalent group of 1～3 rings in 3～12 the ester ring type ring for singly-bound or comprise; R ⁶Be hydrogen, fluorine ,-CN ,-OH, carbon number are that 1～30 alkyl, carbon number are that 1～30 fluorinated alkyl or carbon number are 1～30 alkoxyl group; And, work as X ¹, G ¹, X ²And G ²When all being singly-bound, R ⁶Be that carbon number is that 3～30 alkyl, carbon number are that 3～30 fluorinated alkyl or carbon number are 3～30 alkoxyl group, work as G ²Singly-bound and X ²Neither when singly-bound neither alkylidene group, R ⁶Be that hydrogen or carbon number are 3～30 alkyl, work as G ¹And G ²When being singly-bound, X ¹, X ²And R ⁶The total carbon number more than or equal to 3;

Herein, R ⁷That hydrogen or carbon number are 1～12 alkyl; Ring B be arbitrarily hydrogen can by carbon number be the Isosorbide-5-Nitrae that replaces of 1～4 alkyl-Ya benzene or arbitrarily hydrogen can be the Isosorbide-5-Nitrae that replaces of 1～4 alkyl-stretch cyclohexyl by carbon number; X ⁰Be that singly-bound or carbon number are 1～5 alkylidene group, and s is 0～3 integer; When s was 2 or 3, a plurality of ring B can all be identical ring, also can be made of a plurality of X at least 2 different rings ⁰Can all be identical group, also can be consisted of by at least 2 different groups; Z ¹And Z ²Independent be singly-bound ,-CH ₂-,-CH ₂CH ₂-or-O-, t1 and t2 independently are 0～3 integer; When t1 is 2 or 3, a plurality of Z ¹Can all be identical group, also can be consisted of by at least 2 different groups; When t2 is 2 or 3, a plurality of Z ²Can all be identical group, also can be consisted of by at least 2 different groups;

8. orientation agent according to claim 1 is characterized in that:

The polyamic acid that has photosensitive group on the main chain is the polyamic acid that obtains in the following way, make by formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), the diamines with photosensitive group that formula (V-1) and formula (VI-1)～formula (VI-7) is represented at least a, at least a by the represented diamines of formula (VII-1)～formula (VII-3) and formula (VIII-1)～formula (VIII-6), and select in the represented diamines of free style (2)～formula (4) at least a mixture and by formula (A-1), formula (A-2), formula (A-12), formula (A-14), formula (A-18), formula (A-20), formula (A-21), formula (A-37), formula (VII-4), formula (VII-5), formula (VIII-7) and represented at least a of tetracarboxylic dianhydride of formula (VIII-8) react:

H ₂N-R ⁴-NH ₂ (VII-1)

Herein, X ¹And X ²Be singly-bound ,-O-,-COO-,-OCO-,-NH-,-CONH-or carbon number are 1～12 alkylidene group; G ¹And G ²That to be selected from carbon number be that 6～12 aromatic ring and carbon number are the divalent group of 1～3 rings in 3～12 the ester ring type ring for singly-bound or comprise; R ⁶Be hydrogen, fluorine ,-CN ,-OH, carbon number are that 1～30 alkyl, carbon number are that 1～30 fluorinated alkyl or carbon number are 1～30 alkoxyl group; And, work as X ¹, G ¹, X ²And G ²When all being singly-bound, R ⁶Be that carbon number is that 3～30 alkyl, carbon number are that 3～30 fluorinated alkyl or carbon number are 3～30 alkoxyl group, work as G ²Singly-bound and X ²Neither when singly-bound neither alkylidene group, R6 was that hydrogen or carbon number are 3～30 alkyl, works as G ¹And G ²When being singly-bound, X ¹, X ²And R ⁶The total carbon number more than or equal to 3;

Herein, R ⁷That hydrogen or carbon number are 1～12 alkyl; Ring B be arbitrarily hydrogen can by carbon number be the Isosorbide-5-Nitrae that replaces of 1～4 alkyl-Ya benzene or arbitrarily hydrogen can be the Isosorbide-5-Nitrae that replaces of 1～4 alkyl-stretch cyclohexyl X by carbon number ⁰Be that singly-bound or carbon number are 1～5 alkylidene group, and s is 0～3 integer; When s was 2 or 3, a plurality of ring B can all be identical ring, also can be made of a plurality of X at least 2 different rings ⁰Can all be identical group, also can be consisted of by at least 2 different groups; Z ¹And Z ²Independent be singly-bound ,-CH ₂-,-CH ₂CH ₂-or-O-, t1 and t2 independently are 0～3 integer; When t1 is 2 or 3, a plurality of Z ¹Can all be identical group, also can be consisted of by at least 2 different groups; When t2 is 2 or 3, a plurality of Z ²Can all be identical group, also can be consisted of by at least 2 different groups;

9. liquid crystal orienting film, it is characterized in that: it is to obtain in the following way, by rayed to will be according to claim 1 in 8 each described orientation agent be coated on the film that obtains on the substrate and give anisotropy, then be heated to till the liquid crystal temperature range of film and the anisotropy of film increased.

10. a liquid crystal display device is characterized in that: comprise liquid crystal orienting film according to claim 9.

11. a polyimide or as the polyamic acid of its precursor is characterized in that:

Comprise by the represented Component units of formula (IX), and have liquid crystal temperature range at 100 ℃～300 ℃:

Herein, R ⁵That carbon number is 6～12 alkylidene group; R ⁹By any one the residue in the represented diamines of formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), formula (V-1) and formula (VI-1)～formula (VI-7):

12. a polyimide or as the polyamic acid of its precursor is characterized in that:

Comprise by the represented Component units of formula (X), and have liquid crystal temperature range at 100 ℃～300 ℃:

13. polyimide according to claim 11 or as the polyamic acid of its precursor is characterized in that:

R ⁹By any one the residue in the represented diamines of formula (VIII-1)～formula (VIII-6):

14. polyimide according to claim 12 or as the polyamic acid of its precursor is characterized in that:

15. a polyimide or as the polyamic acid of its precursor is characterized in that:

Comprise by the represented Component units of formula (IX) and by the represented Component units of formula (XI), and have liquid crystal temperature range at 100 ℃～300 ℃:

Herein, R ⁵That carbon number is 6～12 alkylidene group; R ⁹By any one the residue in the represented diamines of formula (I-1)～formula (I-3), formula (II-1)～formula (II-3), formula (III-1), formula (IV-1)～formula (IV-3), formula (V-1) and formula (VI-1)～formula (VI-7); R ¹⁰By any one the residue in the represented diamines of formula (VIII-1)～formula (VIII-6):

16. a polyimide or as the polyamic acid of its precursor is characterized in that:

Comprise by the represented Component units of formula (X) and by the represented Component units of formula (XII), and have liquid crystal temperature range at 100 ℃～300 ℃: