JP4640540B2

JP4640540B2 - Alignment film manufacturing method

Info

Publication number: JP4640540B2
Application number: JP2000282915A
Authority: JP
Inventors: 丈也酒井; 正雄植月; 喜弘川月
Original assignee: Hayashi Telempu Corp
Current assignee: Hayashi Telempu Corp
Priority date: 2000-09-19
Filing date: 2000-09-19
Publication date: 2011-03-02
Anticipated expiration: 2020-09-19
Also published as: JP2002090750A

Description

【０００１】
【発明の属する技術分野】
本発明は、感光性の重合体の膜に、直線偏光性または部分偏光性の光を照射することによって、液晶パネルに封入した液晶の配向を促進する膜を提供し、液晶表示装置の製造方法の改良に役立つものである。
【０００２】
【従来の技術】
従来、液晶パネルに封入した液晶を配向させるには、図２に示すような、基板（２１）に塗布したポリイミド、ポリビニルアルコール、ポリエチレンテレフタレートなどの高分子化合物の表面（２２）をナイロンやポリエステル繊維を植毛した布（２４）を巻きつけたドラム（２３）で擦り、これら高分子化合物を配向させるか、表面に極微細な溝を形成する方法、またはそれらフィルムを延伸配向させ異方性を付与する方法、更には、酸化珪素（ＳiＯ）を基板に対して斜めから蒸着して得られるＳiＯ斜方蒸着膜を利用する方法などにより作製された配向膜が利用されてきた。
【０００３】
【発明が解決しようとする課題】
このような、高分子化合物の表面を植毛した布で物理的に擦る方法は、微細な埃の発生による液晶製造ラインの汚染や静電気による放電が原因のＴＦＴ（薄膜トランジスタ）素子の破壊など、液晶パネルの製造工程において問題となっていた。また、ＳiＯの斜方蒸着法は、基板上での蒸着角や膜厚の均一性を保つことが難しいことやプロセスが大掛かりになってしまうなどの問題点があった。また、これらの従来法では、同一の基板内における液晶分子の配向は一定方向のみとなり、同一の基板内に配向方向が異なる領域を有する膜を作製できなかった。
【０００４】
【課題を解決する手段】
前記の問題に鑑み、本発明では、側鎖に少なくとも化学式１で表される構造を含み、主鎖が炭化水素、アクリレート、メタクリレート、マレイミド、Ｎ−フェニルマレイミド、シロキサンである化学式２で表される単位を含有する感光性の重合体であり、該単位の単独重合体、または共重合体、更には、アルキル基、アルコキシ基、アルケニル基、アルケニルオキシ基、シクロヘキシル基、シクロヘキセニル基およびそれらを弗化した基などを含む単位を少なくとも一つこれらに共重合した重合体を用いた配向膜およびその製造方法を提供する。
【化２】

但し、ｎ＝１〜１２、Ｘ＝ｎｏｎｅ、−ＣＯＯ、−ＯＣＯ−、−Ｎ=Ｎ−、−Ｃ=Ｃ−ｏｒ−Ｃ₆Ｈ₄−、−Ｒ₁〜−Ｒ₈＝−Ｈ、ハロゲン基、またはメトキシ基などのアルキルオキシ基、更に−Ｒ₉＝メチル基、エチル基などのアルキル基、またはそれらを弗化した基である。
該重合体は側鎖に感光性基を含み、該重合体の塗布膜に直線偏光性または部分偏光性の紫外線を照射することにより、感光性基の部分が反応し、配向膜を形成し得る。この解決手段によって微細な埃の発生や静電気による放電、大掛かりなプロセス、一方向のみの配向など、従来技術の問題点が解決される。
【０００５】
【発明の実施の形態】
以下に、本発明の詳細を説明する。前述の単独重合体または共重合体は、液晶性高分子のメソゲン成分として多用されているビフェニル、ターフェニル、フェニルベンゾエート、アゾベンゼンなどの置換基と感光性基からなる構造成分が、炭化水素、アクリレート、メタクリレート、マレイミド、Ｎ−フェニルマレイミド、シロキサンなどの主鎖にスペーサーを介して結合した液晶性を有する重合体である。また、該重合体に、液晶性を損なわない程度の低分子を添加することや、液晶性を損なうことなく液晶性を示さない共重合モノマーと共重合してもかまわない。該重合体の溶液を基板上に塗布（スピンコート）した重合体塗布膜を形成する。該重合体塗布膜は、製膜時には等方的であるが、該膜に直線偏光性または部分偏光性の紫外線を照射すると、照射光の電界振動方向または最も電界振動の強い方向に沿い配置されている感光性基の光反応が優先的に進行し、異方性の膜となる。この光反応を進めるには、化学式１の感光性の部分が反応し得る波長の直線偏光の照射を要する。この波長は、化学式１で示された−Ｒ₁〜−Ｒ₉の種類によっても異なるが、一般に２００−５００nmであり、中でも２５０−４５０nmの有効性が高い場合が多い。
【０００６】
この直線偏光性または部分偏光性の光を照射することにより発現する膜の異方性は、照射する直線偏光性または部分偏光性の光の照射エネルギが低い場合と高い場合では異方性の発現する方向が９０度変化することが実験的に確認されている。化学式２において、ｎ＝６、Ｘ＝−ＣＯＯ、−Ｒ₁〜−Ｒ₈＝−Ｈ、−Ｒ₉＝メチル基、主鎖がメタクリレートである重合体を用いた場合、照射する直線偏光の照射エネルギを１５０ｍＪ／ｃｍ²とし、照射後１３０℃で５分間熱処理すると、図３に示すように照射した直線偏光の電界振動と平行方向と垂直方向で紫外光域の吸光度に差が生じる。照射した直線偏光の電界振動と平行方向の２７５ｎｍにおける吸光度をＡ//、垂直方向の２７５ｎｍにおける吸光度をＡ⊥とすると、二色比ＤＲ〔＝（Ａ//−Ａ⊥）／（Ａ//＋Ａ⊥）〕は−０．４７と求められ、Ａ⊥＞Ａ//となることが確認された。これに対し、照射する直線偏光の照射エネルギを５００ｍＪ／ｃｍ²まで増加し、照射後１３０℃で５分間熱処理すると、図４に示すように照射した直線偏光の電界振動と平行な方向と垂直な方向で紫外光域の吸光度に差が生じ、そのときの２７５ｎｍにおける二色比ＤＲは０．４９と求められ、Ａ⊥＜Ａ//となることが確認された。このように本発明の感光性化合物では照射した直線偏光の照射エネルギにより膜の異方性が９０度変化することが確認されている。異方性の膜に、液晶分子が接触した場合、液晶分子は膜との相互作用により、一定方向に配向するようになる。本発明の感光性化合物でも、このような液晶配向性が確認されており、膜の異方性が直線偏光の照射エネルギにより９０度変化するのに合わせて、液晶配向方向も直線偏光の照射エネルギにより９０度変化することが確認されている。
【０００７】
また、本発明の重合体において、低い照射エネルギの時に発現するに二色性は、１６０℃程度の加熱により比較的容易に解消できることが確認されており、熱と光による書き込み消去型の光記録材料として、また、直線偏光の光照射により、電界振動と平行方向の感光性基が選択的に反応するが、続く熱処理により感光部位が方向性なく可逆的に戻ることから、光照射と熱処理を繰り返すことにより異方性が増加し、高度に配向したフィルムとなり、位相差フィルムとしても利用可能である。
【０００８】
このようなことから、本発明の感光性の重合体は、基板に塗布（スピンコート）して製膜し、同一の基板内の領域毎に直線偏光性または部分偏光性の光の照射エネルギを変化させることによって、同一の基板内に液晶配向方向のことなる領域を付与することができることから、物理的に基板表面を擦るなどの工程が不要で、静電気、埃などを発生することなく、液晶パネルにおいて液晶配向方向を画素毎に制御した液晶表示装置を提供できる。更には、光照射と熱処理という比較的簡便な手法により書き込み消去型の光記録材料、位相差フィルムを提供できる。
【０００９】
【実施例】
図１には、本発明の重合体を用いた液晶配向膜の製造方法（装置）を示す。電源（１２）によって励起された紫外線ランプ（１１）で発生した非偏光（１６）を、光学素子（１３）（例えばグランテーラープリズム）を介して、偏光紫外線（１７）に変換し、基板（１５）上に塗布された樹脂膜（１４）に照射する（基板法線方向から照射すると限定するものではない）。
【００１０】
（実施例１）化学式３で示される重合体１は、昇温過程で３５℃と２１０℃に吸熱ピークが認められ、偏光顕微鏡で観察すると、該温度領域で複屈折性の光学模様を発現する液晶性の材料である。該重合体をクロロホルムに溶解し、ＩＴＯ（インジウム錫酸化物）で覆った基板上に約１００nmの厚さでスピンコートした。該基板にグランテーラープリズムを用いて直線偏光に変換した紫外線（５０ｍＷ／ｃｍ²）を、水平面に対し垂直方向から室温で３秒間照射した。この基板２枚を、直線偏光を照射したときの電界振動方向が平行になるよう対向させて液晶セルを作製し、この液晶セルに２色性色素ＤｉｓｐｅｒｓｅＢｌｕｅ１４（アルドリッチ社製）を分散させた液晶Ｅ７（メルクジャパン社製）を充填し、８０℃まで加熱し液晶を等方相としたのち室温まで冷却した。偏光顕微鏡でこの液晶セルを観察したところ液晶の配向方向は照射した直線偏光の電界振動と垂直方向であることが確認された。更に、片方の基板を９０度回転したセルを組み立て、液晶Ｅ７を充填し、ＴＮ型セルを作製したところ、両基板間への電圧印加により液晶セルの駆動が確認された。
【化３】

【００１１】
（実施例２）重合体１をクロロホルムに溶解し、ＩＴＯ（インジウム錫酸化物）で覆った基板上に約１００nmの厚さでスピンコートした。該基板にグランテーラープリズムを用いて直線偏光に変換した紫外線（５０ｍＷ／ｃｍ²）を、水平面に対し垂直方向から室温で１０秒間照射した。この基板２枚を、直線偏光を照射したときの電界振動方向が平行になるよう対向させて液晶セルを作製し、この液晶セルに２色性色素ＤｉｓｐｅｒｓｅＢｌｕｅ１４（アルドリッチ社製）を分散させた液晶Ｅ７（メルクジャパン社製）を充填し、８０℃まで加熱し液晶を等方相としたのち室温まで冷却した。偏光顕微鏡でこの液晶セルを観察したところ液晶の配向方向は照射した直線偏光の電界振動と平行方向であることが確認された。更に、片方の基板を９０度回転したセルを組み立て、液晶Ｅ７を充填し、ＴＮ型セルを作製したところ、両基板間への電圧印加により液晶セルの駆動が確認された。
【００１２】
（実施例３）重合体１をクロロホルムに溶解し、ＩＴＯ（インジウム錫酸化物）で覆った基板上に約１００nmの厚さでスピンコートした。該基板にグランテーラープリズムを用いて直線偏光に変換した紫外線（５０ｍＷ／ｃｍ²）を、水平面に対し垂直方向から室温で７秒間照射した。次いで、マスクパターンを用い、マスクされた領域以外のみ電界方向の揃った直線偏光の紫外線を更に３秒間照射した。この基板とマスクを用いず直線偏光の紫外線を１０秒間照射した基板とを用い、直線偏光を照射したときの電界振動方向が平行になるよう対向させて液晶セルを作製し、この液晶セルにメルクジャパン（株）製の液晶Ｅ７を充填し、８０℃まで加熱し液晶を等方相としたのち室温まで冷却した。偏光顕微鏡の直交ニコル、平行ニコルで観察したところマスクパターンと合致した明暗反転が観察された。
【００１３】
【発明の効果】
以上に記述したように、本発明によれば、感光性の重合体への直線偏光性または部分偏光性の光の照射によって配向膜が得られると共に、この膜を液晶表示装置用の配向膜に応用できる。更に、照射量により液晶分子の配向が９０度変化することから、１つのマスクパターンで液晶の配向を２方向に制御できるので、マスクパターンを２つ必要とせず位置合わせも不要とすることができる。また、ラビングなど、液晶分子を配向させる操作が不要な配向膜が調製されるので、液晶表示装置の組立工程で生じる欠陥が著しく低減される。
【００１４】
【図面の簡単な説明】
【図１】本発明の配向膜の製造方法を示す概念図
【図２】従来の配向膜の製造方法を示す例図
【図３】本発明の重合体に直線偏光性の紫外光を１５０ｍＪ／ｃｍ²照射し、照射後１３０℃で５分間熱処理したときの偏光紫外吸収スペクトル
【図４】本発明の重合体に直線偏光性の紫外光を５００ｍＪ／ｃｍ²照射し、照射後１３０℃で５分間熱処理したときの偏光紫外吸収スペクトル
【符号の説明】
１１・・・紫外線ランプ
１２・・・電源
１３・・・光学素子（グランテーラープリズム）
１４・・・樹脂膜（感光性の重合体）
１５・・・基板
１６・・・非偏光（紫外線）
１７・・・偏光（紫外線）[0001]
BACKGROUND OF THE INVENTION
The present invention provides a film for accelerating alignment of liquid crystal sealed in a liquid crystal panel by irradiating a photosensitive polymer film with linearly polarized light or partially polarized light, and a method for manufacturing a liquid crystal display device It is useful for improvement.
[0002]
[Prior art]
Conventionally, in order to align the liquid crystal sealed in the liquid crystal panel, the surface (22) of a polymer compound such as polyimide, polyvinyl alcohol, polyethylene terephthalate, etc. applied to the substrate (21) as shown in FIG. Rubbing with a drum (23) wound with a cloth (24) wound with hair, orienting these polymer compounds, or forming ultrafine grooves on the surface, or stretching and orienting these films to impart anisotropy In addition, an alignment film produced by a method using a SiO oblique deposition film obtained by obliquely depositing silicon oxide (SiO) on a substrate has been used.
[0003]
[Problems to be solved by the invention]
Such a method of physically rubbing the surface of a polymer compound with a flocked cloth is a liquid crystal panel, such as contamination of a liquid crystal production line due to generation of fine dust or destruction of a TFT (thin film transistor) element due to electrostatic discharge. This has been a problem in the manufacturing process. Further, the oblique deposition method of SiO has problems that it is difficult to maintain the uniformity of the deposition angle and the film thickness on the substrate and that the process becomes large. In these conventional methods, the alignment of liquid crystal molecules in the same substrate is only in a certain direction, and a film having regions with different alignment directions in the same substrate cannot be produced.
[0004]
[Means for solving the problems]
In view of the above problems, in the present invention, the side chain includes at least a structure represented by Chemical Formula 1, and the main chain is represented by Chemical Formula 2 in which the main chain is hydrocarbon, acrylate, methacrylate, maleimide, N-phenylmaleimide, or siloxane. A photosensitive polymer containing a unit, a homopolymer or copolymer of the unit, an alkyl group, an alkoxy group, an alkenyl group, an alkenyloxy group, a cyclohexyl group, a cyclohexenyl group, and a fluoropolymer thereof. Provided are an alignment film using a polymer obtained by copolymerizing at least one unit containing a group containing a group and the like, and a method for producing the alignment film.
[Chemical 2]

However, n = 1 to 12, X = none, —COO, —OCO—, —N═N—, —C═C—or—C ₆ H ₄ —, —R ₁ to —R ₈ = —H, halogen Or an alkyloxy group such as a methoxy group, -R ₉ = an alkyl group such as a methyl group or an ethyl group, or a group obtained by fluorinating them.
The polymer contains a photosensitive group in the side chain. By irradiating the coating film of the polymer with linearly polarized light or partially polarized light, the photosensitive group part can react to form an alignment film. . This solution solves the problems of the prior art such as generation of fine dust, discharge due to static electricity, large-scale processes, and orientation in only one direction.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Details of the present invention will be described below. The above-mentioned homopolymer or copolymer has a structural component composed of a substituent and a photosensitive group such as biphenyl, terphenyl, phenylbenzoate and azobenzene, which are frequently used as a mesogenic component of a liquid crystalline polymer, and is composed of a hydrocarbon or an acrylate. , Methacrylate, maleimide, N-phenylmaleimide, siloxane and the like, and a polymer having liquid crystallinity bonded to the main chain through a spacer. Further, a low molecular weight that does not impair the liquid crystallinity may be added to the polymer, or it may be copolymerized with a copolymerization monomer that does not exhibit liquid crystallinity without impairing the liquid crystallinity. A polymer coating film is formed by applying (spin coating) the polymer solution onto a substrate. The polymer coating film is isotropic at the time of film formation. However, when the film is irradiated with linearly polarized light or partially polarized ultraviolet light, the polymer coated film is disposed along the direction of electric field vibration of the irradiated light or the strongest electric field vibration. The photoreaction of the photosensitive group that has proceeded preferentially, resulting in an anisotropic film. In order to proceed with this photoreaction, it is necessary to irradiate linearly polarized light having a wavelength with which the photosensitive portion of Chemical Formula 1 can react. This wavelength varies depending on the type of —R ₁ to —R ₉ represented by Chemical Formula 1, but is generally 200 to 500 nm, and in particular, the effectiveness of 250 to 450 nm is often high.
[0006]
The anisotropy of the film that is manifested by irradiating the linearly or partially polarized light is manifested when the irradiation energy of the irradiating linearly or partially polarized light is low and high. It has been experimentally confirmed that the direction of movement changes by 90 degrees. Irradiation with linearly polarized light when using a polymer in which n = 6, X = —COO, —R ₁ to —R ₈ = —H, —R ₉ = methyl group, and the main chain is methacrylate. When the energy is 150 mJ / cm ² and heat treatment is performed at 130 ° C. for 5 minutes after irradiation, there is a difference in the absorbance in the ultraviolet region between the vertical direction and the electric field vibration of the linearly polarized light irradiated as shown in FIG. When the absorbance at 275 nm in the direction parallel to the electric field vibration of the linearly polarized light irradiated is A //, and the absorbance at 275 nm in the vertical direction is A⊥, the dichroic ratio DR [= (A // − A⊥) / (A // + A⊥)] was determined to be −0.47, and it was confirmed that A⊥> A //. On the other hand, when the irradiation energy of the linearly polarized light to be irradiated is increased to 500 mJ / cm ² and heat-treated at 130 ° C. for 5 minutes after irradiation, as shown in FIG. 4, it is perpendicular to the direction parallel to the electric field vibration of the irradiated linearly polarized light. A difference in the absorbance in the ultraviolet region occurs depending on the direction, and the dichroic ratio DR at 275 nm at that time was found to be 0.49, and it was confirmed that A⊥ <A //. Thus, it has been confirmed that in the photosensitive compound of the present invention, the anisotropy of the film changes by 90 degrees depending on the irradiation energy of the linearly polarized light irradiated. When liquid crystal molecules are in contact with the anisotropic film, the liquid crystal molecules are aligned in a certain direction due to the interaction with the film. Even in the photosensitive compound of the present invention, such liquid crystal orientation has been confirmed. As the anisotropy of the film changes by 90 degrees depending on the irradiation energy of the linearly polarized light, the liquid crystal alignment direction also changes the irradiation energy of the linearly polarized light. Has been confirmed to change by 90 degrees.
[0007]
In the polymer of the present invention, it has been confirmed that the dichroism developed at low irradiation energy can be eliminated relatively easily by heating at about 160 ° C. As a material and by irradiation with linearly polarized light, the photosensitive group in the direction parallel to the electric field vibration selectively reacts, but the photosensitive part returns reversibly without directionality by the subsequent heat treatment. By repeating, the anisotropy increases, and a highly oriented film can be obtained, which can also be used as a retardation film.
[0008]
Therefore, the photosensitive polymer of the present invention is coated (spin coated) on a substrate to form a film, and the irradiation energy of linearly polarized light or partially polarized light is applied to each region in the same substrate. By changing, it is possible to provide a region having a different liquid crystal alignment direction in the same substrate, so that a process such as physically rubbing the surface of the substrate is unnecessary, and the liquid crystal is generated without generating static electricity or dust. In the panel, a liquid crystal display device in which the liquid crystal alignment direction is controlled for each pixel can be provided. Furthermore, a write / erase optical recording material and a retardation film can be provided by a relatively simple method of light irradiation and heat treatment.
[0009]
【Example】
In FIG. 1, the manufacturing method (apparatus) of the liquid crystal aligning film using the polymer of this invention is shown. The non-polarized light (16) generated by the ultraviolet lamp (11) excited by the power source (12) is converted into polarized ultraviolet light (17) through the optical element (13) (for example, a Grand Taylor prism), and the substrate (15 ) Irradiate the resin film (14) applied thereon (it is not limited to the irradiation from the substrate normal direction).
[0010]
(Example 1) The polymer 1 represented by Chemical Formula 3 has endothermic peaks at 35 ° C and 210 ° C during the temperature rising process, and exhibits a birefringent optical pattern in the temperature region when observed with a polarizing microscope. It is a liquid crystalline material. The polymer was dissolved in chloroform and spin-coated at a thickness of about 100 nm on a substrate covered with ITO (indium tin oxide). The substrate was irradiated with ultraviolet light (50 mW / cm ² ) converted into linearly polarized light using a Grand Taylor prism at room temperature for 3 seconds from a direction perpendicular to the horizontal plane. A liquid crystal cell is prepared by making these two substrates face each other so that the direction of electric field vibration when irradiated with linearly polarized light is parallel. A liquid crystal in which a dichroic dye Disperse Blue 14 (manufactured by Aldrich) is dispersed in the liquid crystal cell. E7 (Merck Japan Co., Ltd.) was charged, heated to 80 ° C. to make the liquid crystal isotropic phase, and then cooled to room temperature. When this liquid crystal cell was observed with a polarizing microscope, it was confirmed that the alignment direction of the liquid crystal was perpendicular to the electric field vibration of the irradiated linearly polarized light. Further, a cell in which one substrate was rotated by 90 degrees was assembled, filled with liquid crystal E7, and a TN type cell was fabricated. As a result, driving of the liquid crystal cell was confirmed by voltage application between both substrates.
[Chemical 3]

[0011]
(Example 2) Polymer 1 was dissolved in chloroform and spin-coated at a thickness of about 100 nm on a substrate covered with ITO (indium tin oxide). The substrate was irradiated with ultraviolet rays (50 mW / cm ² ) converted into linearly polarized light using a Grand Taylor prism at room temperature for 10 seconds from a direction perpendicular to the horizontal plane. A liquid crystal cell is prepared by making these two substrates face each other so that the direction of electric field vibration when irradiated with linearly polarized light is parallel. A liquid crystal in which a dichroic dye Disperse Blue 14 (manufactured by Aldrich) is dispersed in the liquid crystal cell. E7 (Merck Japan Co., Ltd.) was charged, heated to 80 ° C. to make the liquid crystal isotropic phase, and then cooled to room temperature. When this liquid crystal cell was observed with a polarizing microscope, it was confirmed that the alignment direction of the liquid crystal was parallel to the electric field vibration of the irradiated linearly polarized light. Further, a cell in which one substrate was rotated by 90 degrees was assembled, filled with liquid crystal E7, and a TN type cell was fabricated. As a result, driving of the liquid crystal cell was confirmed by voltage application between both substrates.
[0012]
(Example 3) Polymer 1 was dissolved in chloroform and spin-coated at a thickness of about 100 nm on a substrate covered with ITO (indium tin oxide). The substrate was irradiated with ultraviolet rays (50 mW / cm ² ) converted into linearly polarized light using a Grand Taylor prism at room temperature for 7 seconds from a direction perpendicular to the horizontal plane. Next, using a mask pattern, linearly polarized ultraviolet rays having a uniform electric field direction were irradiated for another 3 seconds except for the masked region. Using this substrate and a substrate irradiated with linearly polarized UV light for 10 seconds without using a mask, a liquid crystal cell was fabricated so that the electric field oscillation directions when irradiated with linearly polarized light were parallel to each other. Liquid crystal E7 manufactured by Japan Co., Ltd. was filled, heated to 80 ° C. to make the liquid crystal isotropic phase, and then cooled to room temperature. When observed with crossed Nicols and parallel Nicols with a polarizing microscope, inversion of light and darkness that matched the mask pattern was observed.
[0013]
【The invention's effect】
As described above, according to the present invention, an alignment film can be obtained by irradiating a photosensitive polymer with linearly or partially polarized light, and this film can be used as an alignment film for a liquid crystal display device. Can be applied. Furthermore, since the orientation of the liquid crystal molecules changes by 90 degrees depending on the irradiation amount, the orientation of the liquid crystal can be controlled in two directions with one mask pattern, so that two mask patterns are not required and alignment is not required. . In addition, since an alignment film that does not require an operation for aligning liquid crystal molecules such as rubbing is prepared, defects generated in the assembly process of the liquid crystal display device are significantly reduced.
[0014]
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a method for producing an alignment film of the present invention. FIG. 2 is an example showing a method for producing a conventional alignment film. FIG. 3 is a polymer of the present invention. Polarized ultraviolet absorption spectrum when irradiated with cm ² and heat-treated at 130 ° C. for 5 minutes after irradiation. FIG. 4 The polymer of the present invention was irradiated with 500 mJ / cm ² of linearly polarized ultraviolet light and irradiated at 130 ° C. Polarized UV absorption spectrum after heat treatment for minutes [Explanation of symbols]
11 ... UV lamp 12 ... Power supply 13 ... Optical element (Grant Taylor prism)
14 ... Resin film (photosensitive polymer)
15 ... Substrate 16 ... Non-polarized light (ultraviolet light)
17 ... Polarized light (ultraviolet light)

Claims

A step of coating a photosensitive polymer containing a structure represented by Chemical Formula 1 on the side chain on the substrate, and a step of irradiating the coated polymer with linearly polarized light or partially polarized light; Irradiation of light having polarization or partial polarization includes an operation performed on the polymer coated on the substrate at a different dose depending on a region, and heating the substrate coated with the photosensitive polymer, and A method for producing an alignment film, characterized in that, by a cooling step, regions having orientation directions different from each other by 90 degrees are formed in a plane of a polymer coated on the substrate .

However, n = 1 to 12, X = none, —COO, —OCO—, —N = N—, —C═C—or—C ₆ H ₄ —, —R ₁ to —R ₈ = —H, halogen Or an alkyloxy group such as a methoxy group, -R ₉ = an alkyl group such as a methyl group or an ethyl group, or a group obtained by fluorinating them.