JP6192710B2 - Surface director alignment layer and liquid crystal device including the layer - Google Patents

Description

  The present invention relates to a polymer compound used for a surface director alignment layer, and a liquid crystal device using the surface director alignment layer.

  A liquid crystal device typically includes a liquid crystal material layer arranged on a substrate or sandwiched between a pair of substrates.

  Liquid crystal molecules are typically relatively fixed molecules that exhibit shape anisotropy that has the ability to self-assemble along the long axis of a particular preferred direction. The average direction of the molecule is specified by the vector quantity and is called the director.

  In liquid crystal displays (LCDs), the desired initial alignment of liquid crystal molecules in the absence of an external field, such as an electric field, is generally appropriate surface treatment of the confined solid substrate, typically a confined substrate facing the liquid crystal bulk. This is achieved by applying a so-called alignment layer on the surface of the substrate. The initial liquid crystal orientation is defined by the solid surface / liquid crystal interaction at the interface between the liquid crystal layer and the alignment layer.

  The orientation of the liquid crystal molecules adjacent to the confining surface is transferred to the liquid crystal molecules in the bulk by elastic forces, thus giving essentially the same alignment to all liquid crystal bulk molecules.

  A director of liquid crystal molecules (also referred to herein as a surface director) near the interface between the liquid crystal layer and the alignment layer is perpendicular to the confined substrate surface and is also referred to as homeotropic alignment or vertical alignment (VA) or closed Parallel to the substrate surface, the so-called homogeneous or planar orientation (PA), or a pre-defined tilt angle, also referred to as the pretilt angle relative to the confined substrate surface, approximate vertical orientation and planar spacing, tilt angle (TA ), And so on. The type of alignment desired in a liquid crystal display depends on the intended use of the device.

  Known methods for setting the alignment layer are, for example, an organic film rubbing method and an inorganic film vapor deposition method.

  According to the organic film rubbing method, an organic coating such as polyimide is formed on the substrate surface. The organic coating is then rubbed in a predetermined direction using a fabric such as cotton, nylon or polyester. As a result, the liquid crystal molecules in contact with the organic layer are aligned along the rubbing direction. However, the rubbing method has the problem that scratches may occur on the surface of the alignment film due to mechanical rubbing, and that static electricity that may cause damage to thin film transistors in the liquid crystal display device may occur.

  In the inorganic film deposition method, the inorganic film is formed on the substrate surface obliquely with respect to the confined substrate by vapor deposition of an inorganic substrate such as a silicon oxide substrate, so that the liquid crystal molecules depend on the inorganic material and the deposition conditions. The film is oriented in a specific direction by the inorganic film. Due to the high manufacturing costs, this method is not suitable for mass production and therefore this method is not used in practice.

A more recent technique for setting the alignment layer is photo-alignment, which involves exposing the alignment layer to light, which in turn leads to the physical properties of the alignment layer surface inducing a specific alignment direction of the liquid crystal. Causes anisotropy. One advantage of the photo-alignment method is that it is a non-contact process,
And thereby avoiding the above problems associated with organic film rubbing processes.

  Vertical (homeotropic) alignment (VA) and planar alignment (PA) are the two main types of liquid crystal alignment employed in LCDs. Vertical alignment is particularly advantageous in LCD TVs as a very low transmission dark state with excellent contrast ratio. In many cases, for example, a given tilt angle (TA) that can shorten the response time of the liquid crystal material when an electric field is applied and / or promote more uniform reorientation of liquid crystal molecules when an electric field is applied. Thus, it is advantageous to direct the liquid crystal molecules. By inducing a slight pretilt and nearly perpendicular orientation of the liquid crystal molecules with respect to the normal of the substrate surface (e.g. 85-88 ° calculated with respect to the substrate surface), the fast switching of the liquid crystal molecules of the LCD is Can be achieved without significant degradation of contrast.

  European Patent No. 213133 describes a liquid crystal display in which an alignment film can be adapted by light irradiation in order to control the alignment of the liquid crystal molecules so that the average pretilt angle of the liquid crystal molecules is 87 to 89.5 °. Disclosed are polymers for alignment film materials used in devices. The polymer includes a photofunctional group selected from groups consisting of cinnamate groups, azobenzene groups, stilbene groups, cinnamoyl groups, and coumarin groups. However, these photofunctional groups can react non-specifically in many conventional polymerization methods such as radical polymerization, and as a result, the production of polymers according to EP 213133 is for example The polymerization method is limited to a time-consuming polymerization method such as the production of polyimide including the first step of the condensation reaction and the subsequent curing step. As a result, the selection of suitable monomers for use in the polymer backbone according to EP 213133 is also limited.

European Patent No. 213133

  In view of the above and other shortcomings of the prior art, the general object of the present invention is to provide a polymer for a surface director alignment layer that can be easily configured to achieve the desired pretilt angle of the liquid crystal material. It is to provide.

  The present inventors have found that this and other objects can be achieved by utilizing the polymer compound according to the present invention. The present invention provides that a benzophenone moiety or derivative thereof as a photofunctional site in a polymer compound in a surface director alignment layer for very precise control of the desired pretilt angle of liquid crystal molecules in a liquid crystal device by light irradiation of the polymer. Based on the understanding that it can be used to advantage. In particular, the present inventors have shown that the benzophenone moiety or a derivative thereof exhibits excellent optical functional properties of promoting high light stability and thermal stability, and in addition, a polymer compound containing the benzophenone moiety according to the present invention. Has been found to be easily manufactured using radical polymerization methods. According to the present invention, it is possible to obtain an alignment layer that induces a desired pretilt angle of a liquid crystal material distributed non-uniformly over the entire liquid crystal device region.

  According to a first embodiment, the present invention provides a polymer compound for use in a surface director alignment layer. The polymer compound comprises a polymer backbone comprising repeating units; the first side group comprising a photofunctional moiety comprising at least one benzophenone moiety or derivative thereof bonded to at least some of the repeating units. And a second side group bonded to at least some of the repeating units; a second side group having significant shape anisotropy capable of inducing vertical alignment of the liquid crystal material.

  The polymeric compound also optionally includes other functional side groups such as anchor side groups, alkyl side chains or ion transfer inhibiting side groups.

  As used herein, the term “side group with significant shape anisotropy” refers to a molecule with significant shape anisotropy in the actual environment. Side groups with significant anisotropy show a distinct difference between their short axis (axis) and their long axis (axis) and are relatively fixed in the structure.

  When the polymer compound of the present invention is used in a surface director alignment layer, the second side group of the polymer is typically oriented substantially perpendicular to the plane of the alignment layer (and substrate). Thus inducing the vertical alignment of adjacent liquid crystal materials. To achieve the desired pretilt of the liquid crystal material, the polymer compound of the present invention further comprises a first side group comprising at least one photofunctional benzophenone moiety or derivative thereof that is orientationally controllable by light emission. . Light irradiation of the polymer compound leads to the introduction of tilt orientation into the first side group. However, depending on, for example, the molecular structure of the first and second side groups and / or the photoreactive properties of the photofunctional moiety (further described below), the light irradiation can be in addition to the reorientation of the second side group. Or alternatively it may result in reorientation of the first side group. In either case, the light irradiation is performed to achieve the overall orientation of the first and second side groups, resulting in steric and polar interactions between the liquid crystal molecules and the first and second side groups. As a result, the desired pretilt angle of the liquid crystal molecules is promoted.

  Typically, the photofunctional moiety of the present invention is photoreactive. “Photoreactive” means capable of undergoing a chemical reaction in response to irradiation. Such chemical reactions include, for example, dimerization reaction, polymerization reaction, isomerization reaction and the like. The reaction includes a reaction in the first side group, between two or more of the first side groups, between the first side group and the second side group, and / or between the first side group and the polymer backbone. obtain. Therefore, when the polymer compound according to the present invention is used as a surface director alignment layer or in a surface director alignment layer, the orientation property of the first side group including the photoreactive portion and / or the orientation property of the other side group is Providing the desired pretilt angle of the liquid crystal molecules in contact with the surface director alignment layer can be controlled. Through the elastic force, the liquid crystal bulk adopts the same pretilt angle.

（式中、Ｌ_１は、前記繰返し単位に結合した連結基を表し、Ｌ_１は３乃至３０の結合原子、例えば５乃至１５の結合原子を含み；
Ｒ_１は、水素原子、ハロゲン原子、炭素原子数１乃至２０のアルキル基、置換された炭素原子数１乃至２０のアルキル基、炭素原子数１乃至２０のアルコキシ基、置換された炭素原子数１乃至２０のアルコキシ基、炭素原子数１乃至２０のアルケニル基、置換された炭素原子数１乃至２０のアルケニル基、炭素原子数１乃至２０のアルキニル基、置換され
た炭素原子数１乃至２０のアルキニル基、炭素原子数１乃至２０のアミノアルキル基、置換された炭素原子数１乃至２０のアミノアルキル基を表し、典型例としては水素原子、又は炭素原子数１乃至１１のアルキル基又は炭素原子数１乃至１１のアルコキシ基を含み；
ｎは０乃至４であり、
Ｒ_２及びＲ_３は、互いに独立して、水素原子、ハロゲン原子、炭素原子数１乃至３のアルキル基、置換された炭素原子数１乃至３のアルキル基、炭素原子数１乃至３のアルコキシ基、置換された炭素原子数１乃至３のアルコキシ基、炭素原子数１乃至３のアミノアルキル基、置換された炭素原子数１乃至３のアミノアルキル基を表す。）を有し得る。 Advantageously, in an embodiment of the invention, the first side group is represented by the following general formula (I):

(Wherein, L ₁ represents a linking group attached to the repeat units, L ₁ comprises 3 to 30 bonding atoms, such as 5 to 15 binding atoms;
R ₁ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a substituted carbon atom of 1 Alkyl group having 1 to 20 carbon atoms, Alkenyl group having 1 to 20 carbon atoms, Substituted alkenyl group having 1 to 20 carbon atoms, Alkynyl group having 1 to 20 carbon atoms, Alkynyl having 1 to 20 carbon atoms substituted Group, an aminoalkyl group having 1 to 20 carbon atoms, a substituted aminoalkyl group having 1 to 20 carbon atoms, typically a hydrogen atom, an alkyl group having 1 to 11 carbon atoms, or the number of carbon atoms Contains 1 to 11 alkoxy groups;
n is 0 to 4,
R ₂ and R ₃ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, a substituted alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. And a substituted alkoxy group having 1 to 3 carbon atoms, an aminoalkyl group having 1 to 3 carbon atoms, and a substituted aminoalkyl group having 1 to 3 carbon atoms. ).

  In an embodiment of the invention, the second side group has a linear shape anisotropy having a major axis extending along the major extension of the second side group and a minor axis perpendicular to the major axis, and in repeating units. Bonded end-on.

（式中、Ｌ_２は上記繰返し単位に結合した連結基した連結基を表し、Ｌ_２は３乃至３０結合原子、例えば５乃至１５結合原子を含み；
ｍは、０又は１であり、
Ｘは、−ＣＯＯ−、−ＣＨ＝ＣＨ−、又は−Ｃ≡Ｃ−を表し、
Ｒ_４は、水素原子、ハロゲン原子、炭素原子数１乃至２０のアルキル基、置換された炭素原子数１乃至２０のアルキル基、炭素原子数１乃至２０のアルコキシ基、置換された炭素原子数１乃至２０のアルコキシ基、炭素原子数１乃至２０のアルケニル基、置換された炭素原子数１乃至２０のアルケニル基、炭素原子数１乃至２０のアルキニル基、置換された炭素原子数１乃至２０のアルキニル基、炭素原子数１乃至２０のアミノアルキル基、置換された炭素原子数１乃至２０のアミノアルキル基を表し、典型例としてはハロゲン原子、又は炭素原子数１乃至１１のアルキル基又は炭素原子数１乃至１１のアルコキシ基を含み；
ｎは、０乃至４であり、
Ｒ_５及びＲ_６は、互いに独立して、水素原子、ハロゲン原子、炭素原子数１乃至３のアルキル基、置換された炭素原子数１乃至３のアルキル基、炭素原子数１乃至３のアルコキシ基、置換された炭素原子数１乃至３のアルコキシ基、炭素原子数１乃至３のアミノアルキル基、置換された炭素原子数１乃至３のアミノアルキル基を表す。）を有し得る。 Advantageously, in an embodiment of the invention, the second side group has the formula (II)

(Wherein, L ₂ represents a linking group linking group attached to the repeat units, L ₂ comprises 3 to 30 bonding atoms, for example, 5 to 15 bonding atoms;
m is 0 or 1,
X represents —COO—, —CH═CH—, or —C≡C—,
R ₄ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a substituted carbon atom of 1 Alkyl group having 1 to 20 carbon atoms, Alkenyl group having 1 to 20 carbon atoms, Substituted alkenyl group having 1 to 20 carbon atoms, Alkynyl group having 1 to 20 carbon atoms, Alkynyl having 1 to 20 carbon atoms substituted Group, an aminoalkyl group having 1 to 20 carbon atoms, a substituted aminoalkyl group having 1 to 20 carbon atoms, typically a halogen atom, an alkyl group having 1 to 11 carbon atoms, or the number of carbon atoms Contains 1 to 11 alkoxy groups;
n is 0 to 4,
R ₅ and R ₆ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, a substituted alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. And a substituted alkoxy group having 1 to 3 carbon atoms, an aminoalkyl group having 1 to 3 carbon atoms, and a substituted aminoalkyl group having 1 to 3 carbon atoms. ).

When a polymer compound is used as the surface director alignment layer, it is desirable that the liquid crystal molecules of the liquid crystal material be affected by the alignment of both the first and second bases. To accomplish this, advantageously the first side group and the second side group may be the same length. Accordingly, in an embodiment of the present invention, the linking group L ₁ may contain up to 10 more linking atoms than the linking group L ₂ , eg up to 6 more linking atoms.

For example, in an embodiment of the invention, L ₁ may contain up to 6 or more linking atoms than L ₂ and in the above formula, R ₁ may represent a hydrogen atom or a halogen atom, and R ₄ is carbon It may represent an alkyl group having 3 to 6 atoms or an alkoxy group having 3 to 6 carbon atoms, such as a hexyloxy group. In this embodiment, the first and second side groups have similar extensions from the polymer backbone.

The linking groups L ₁ and L ₂ are each optionally substituted with a saturated or unsaturated hydrocarbon chain such as an alkyl group, an alkenyl group, an aryl group, an alkylaryl group, an alkoxy group or a polyether group, an aryloxy group. May contain siloxane chains. For example, L ₁ and L ₂ are independently of each other an alkyl group having 1 to 30 carbon atoms, a substituted alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or a substituted group. An alkoxy group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, a substituted alkenyl group having 1 to 30 carbon atoms, an alkynyl group having 1 to 30 carbon atoms, a substituted carbon atom of 1 It may be an alkynyl group having 1 to 30 carbon atoms, an aminoalkyl group having 1 to 30 carbon atoms, or a substituted aminoalkyl group having 1 to 30 carbon atoms. Typical examples include an alkyl group having 1 to 15 carbon atoms or an alkoxy group having 1 to 15 carbon atoms, such as an alkyl group having 3 to 11 carbon atoms or an alkoxy group having 3 to 11 carbon atoms.

In embodiments where the embodiment of the present invention, the repeating units of the polymer backbone represents maleimide, L ₁ represents an alkoxy group having a carbon number of 11; R _1, R ₂ and R ₃ represent a hydrogen atom; L ₂ and R ₄ represents an alkoxy group having 6 carbon atoms, R ₅ represents a hydrogen atom or an N-alkylamide group, R ₆ represents a hydrogen atom or an N-alkylamide group, m is 1, and X is -COO- is represented.

In another exemplary embodiment of the present invention, the repeating unit of the polymer backbone represents hexyl acrylate, L ₁ represents an alkoxy group having 11 carbon atoms; R ₁ , R ₂ and R ₃ represent a hydrogen atom; L ₂ and R ₄ represent an alkoxy group having 6 carbon atoms, R ₅ represents a hydrogen atom or an N-alkylamide group, R ₆ represents a hydrogen atom or an N-alkylamide group, and m is 1. X is —COO—.

  In an embodiment of the invention, the ratio of the number of first side groups to the number of second side groups in the polymer compound is in the range of 10: 1 to 1: 100, for example 2: 1 to 1:10, for example 1 : 1 range. Using these ratios, the desired degree of reorientation of the first and / or second side groups can be achieved by light irradiation of the polymer.

  In an embodiment of the invention, the ratio of the number of first side groups and the total number of repeating units of the polymer compound is in the range of 1: 1 to 1: 100, for example 1:10.

  The number of first and second side groups relative to the total number of repeating units is typically the appropriate solid surface / liquid crystal interaction at the interface between the liquid crystal layer and the alignment layer containing the polymer, when a polymer is used as the alignment layer. The desired distribution of side groups along the length of the polymer backbone so that there are enough side groups along the polymer backbone to achieve the action and the liquid crystal molecules of the liquid crystal material are oriented with the desired pretilt angle. Can be configured to provide

  The ratio of the number of first side groups to the second side group in the polymer, and the ratio of the number of first and / or second side groups to the total number of repeat units is advantageously the desired pretilt upon irradiation of the polymer. Can be adapted to give corners. The optimum ratio will typically depend on the method used for light irradiation, depending on, for example, the direction of linearly polarized electromagnetic radiation and / or its wavelength, and / or exposure time, temperature, and ambient atmosphere. Let's go. However, the optimal ratio to achieve the desired pretilt can also depend on the structure of each of the first and second side groups.

  In an embodiment of the present invention, the repeating unit can be obtained from at least one of maleimide, acrylate, methacrylate, vinyl, styrene, and N-vinyl lactam monomers, and derivatives thereof, and mixtures thereof.

  In an embodiment of the invention, the polymer backbone comprises a first type of repeating unit, also referred to as a “first repeating unit”, in addition to a second type of repeating unit, referred to herein as a “second repeating unit”. obtain. Each of the first and second repeating units may be selected from maleimide, acrylate, methacrylate, vinyl, styrene, and N-vinyl lactam monomers, and derivatives thereof, and mixtures thereof. The first repeat unit is typically different from the second repeat unit.

  In some embodiments, at least some of the first repeat units can be functionalized with a first side group or a second side group, and at least some of the second repeat units are also optionally first or second. It can be functionalized with a bifunctional group. In other embodiments, some of the second repeat units are functionalized with a first side group and / or at least some of the second repeat units are functionalized with a second side group and The repeat unit may optionally lack the first and second side groups. In still other embodiments, at least some of the first repeat units can be functionalized with a first side group, and at least some of the second repeat units can be functionalized with a second side group, and vice versa. The same is true.

  In an embodiment of the invention, at least some of the repeating units, for example some of the first and / or second repeating units, are typically alkyl groups of 2 to 20 carbon atoms or substituted carbon atoms. It can be functionalized with a third side group which can be an alkyl group of 2 to 20, for example an alkyl group of 2 to 11 carbon atoms, for example an alkyl group of 8 carbon atoms. For example, the third side group can comprise an N-alkylmaleimide.

  Furthermore, in a second aspect, the present invention relates to a surface director alignment layer comprising a polymer compound as a coating as described above on the surface.

In a third aspect, the present invention provides a step of preparing a substrate; applying the above-described polymer compound on the surface of the substrate to prepare a surface director alignment layer; and 1 ° to 89 with respect to the normal of the substrate. Irradiating the surface director alignment layer with electromagnetic radiation, with electromagnetic radiation having an incident angle in the range of °, linearly polarized at the incident surface, and having a wavelength in the range of 200 nm to 400 nm, for example 250 to 320 nm. The present invention relates to a method for photo-alignment of a surface director alignment layer. The incident surface is defined as the surface containing the incident light and the normal of the substrate.

  In a fourth aspect, the invention comprises at least one confinement substrate; a liquid crystal bulk material; and a surface director alignment layer disposed between the at least one confinement substrate and the liquid crystal bulk material, the liquid crystal bulk material comprising A liquid crystal device comprising a surface director alignment layer in contact with the surface of a liquid crystal bulk material, which causes liquid crystal molecules to form a desired pretilt angle with respect to the surface of the surface director alignment layer in the absence of an applied electric field. Here, the surface director alignment layer includes the polymer compound described above.

  In the embodiment of the present invention, the pretilt angle can be adjusted by irradiating the surface director alignment layer with light.

In embodiments of the present invention, the pretilt angle can range from 85 to 89.5 °, such as from 87 to 89.5 °, such as from 87.5 to 88.5 °. Such a small deviation from the vertical alignment (pretilt) reduces the response time of the liquid crystal material and / or promotes a more uniform reorientation of the liquid crystal molecules by the application of an electric field.

In a fifth aspect, the present invention relates to a method for manufacturing the above-described liquid crystal device. The method comprises the steps of preparing a substrate;
Providing a first electrode layer on a substrate;
Applying the polymer compound described herein on the surface of the first electrode layer to prepare a surface director alignment layer;
Electromagnetic radiation at an incident angle in the range of 1 to 89 ° with respect to the normal of the substrate, linearly polarized on the incident surface, and the surface using electromagnetic radiation having a wavelength in the range of 200 to 400 nm, for example 250 to 320 nm Irradiating a director alignment layer; and aligning a liquid crystal material in contact with the alignment layer;
including.

  In a sixth aspect, the present invention relates to the use of the above-described polymer compound in an alignment layer for a liquid crystal device.

  In a seventh aspect, the present invention relates to a liquid crystal display including the liquid crystal device described above or manufactured by the method of manufacturing a liquid crystal device described above.

  These and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the invention:

FIG. 1 is a flowchart for explaining a method for producing a surface director alignment layer according to the present invention. 2a-c are schematic views of a surface director alignment layer produced according to the method of FIG. 1, corresponding to the method steps in the following states; and FIG. 3 is a diagram for explaining the direction of incident electromagnetic wave radiation during light irradiation according to the present invention, and shows the incident surface P and the normal line N of the surface. FIG. 4 is a diagram showing an example liquid crystal device according to an embodiment of the present invention.

  In the following description, the present invention relates to a polymer compound suitable for use in a surface director alignment layer, the synthesis of such a polymer compound, and a liquid crystal device such as a liquid crystal display as a surface director alignment layer or as a surface director. The use of such a polymer in the alignment layer will be described.

  The inventors have surprisingly found that benzophenone moieties or derivatives thereof can be advantageously used as photofunctional moieties in the pendant groups of polymer compounds for use in surface director alignment layers. It was. Because of the photofunctionalization properties of benzophenone or benzophenone derivatives, the polymer compound can be easily controlled to promote the desired pretilt angle of the liquid crystal molecules when used in the surface director alignment layer. Such control is performed by irradiating a polymer compound containing a benzophenone moiety using electromagnetic wave irradiation.

  Embodiments of the surface director alignment layer and the method for photorealignment of this surface director alignment layer according to the present invention will now be described with reference to FIG. 1, which is a flow chart illustrating the method, and a method corresponding generally to FIG. The surface director alignment layer in a state following the process will be described with reference to FIG.

  As a first step, a substrate 201 was prepared. For example, the substrate can be a glass substrate. Typically, an electrode layer is already provided on the surface of the substrate, but if not, a conventional electrode layer can be applied onto the substrate 201 before applying the alignment layer.

  As a second step, the polymer compound according to an embodiment of the present invention is applied onto the substrate 201. This polymer is typically made by first polymerizing a monomer mixture in solution before being dissolved, dispersed or suspended in a solvent, such as a volatile solvent, and the solution / dispersion thereof. The liquid / suspension is coated on the substrate surface and then the solvent is removed. Suitable coating methods include, but are not limited to, conventional methods such as spin coating, spray coating, doctor blade coating, roll coating, flex printing, ink jet printing, dipping methods and the like. Alternatively, in other embodiments of the invention, a reaction mixture comprising a mixture of monomers and / or prepolymers can be coated on the substrate surface, followed by polymerization of the reaction mixture directly on the substrate surface.

  As shown in FIG. 2b, the polymer compound includes a polymer backbone 209 that includes repeat units 204, 205, some of the repeat units 204 have first side groups 206 attached thereto, and other repeat units 205 include it. It has a second side group 207 attached. The first side group 206 includes at least one photofunctional moiety 208 that includes a benzophenone moiety or derivative thereof.

  In FIG. 2b, both the first side group 206 and the second side group 207 have significant shape anisotropy, ie the first and second side groups have a major axis and length extending along the main extension of the second side group. Has linear anisotropy with a minor axis perpendicular to the axis. Both the first and second side groups are end-on bonded to the repeat unit. Thus, as illustrated in FIG. 2a, both the first side group and the second side group are relative to the plane of the surface director alignment layer when no electric field is applied and without exposure of the alignment layer to electromagnetic radiation. It has a substantially vertical orientation.

  As used herein, the term “end-on linked” means the attachment of a side group to the polymer backbone at or near the end of the long axis of the side group molecule. For example, in a rod-like side group, such as a calamitic mesogenic group, the point of attachment is at or near one of the terminal ends of the side group.

  The third step of the method illustrated in FIG. 2c also includes irradiating the polymer compound with linearly polarized electromagnetic radiation 210 having a wavelength in the range of 200 to 400 nm, for example 250 to 320 nm. The polymer compound may be irradiated at an incident angle in the range of 1 ° to 89 °, for example 20 ° to 70 °, for example 30 ° to 60 °, from the normal N of the substrate. The polarization direction of the light is in the incident plane P (see FIG. 3). The normal N of the substrate, the light incident angle α and the incident plane P are shown in FIG.

  Irradiation may be performed for at least 30 seconds, such as at least 40 seconds, such as at least 1 minute. Irradiation may occur for up to 5 and 10 minutes, for example up to 3 minutes, or up to 2 minutes.

As a result of light irradiation, a tilt orientation of at least the first side group 206, and optionally also the second side group 207, as shown in FIG. 2c, was typically achieved. Upon exposure to light irradiation, the photofunctional moiety derived from benzophenone is initiated to undergo a chemical reaction. The chemical reaction is, for example, an irreversible covalent bond (not shown) between the first side group and the adjacent first side group and / or second side group and / or one or more polymer backbone repeat units. Any type of cross-linking reaction that results in formation may be included. It should be noted that such a reaction can result in a change in the orientation of the second side group, as shown in FIG. 2c. However, in an alternative embodiment of the present invention (not shown in FIG. 2c), it imposes an inhomogeneous distribution of pretilt of liquid crystal molecules at the interface between the alignment layer and the liquid crystal layer, all having a tilt alignment. There can be a mixture of non-limiting first and second side groups. However, due to the elastic properties of liquid crystals, such a non-uniform surface distribution of pretilt of liquid crystal molecules becomes uniform in the liquid crystal bulk at a certain distance from the alignment layer, typically less than 100 nm, and the desired pretilt is achieved. The orientation of the liquid crystal layer provided is produced.

  A surface director alignment layer capable of causing alignment of a pretilt angle in the range of 85 ° to 89.5 °, for example, 87.5 ° to 89.5 ° with respect to the surface of the surface director alignment layer on a liquid crystal molecule of the liquid crystal material. Achieving is typically desirable. Thus, if the polymer irradiation produces all or most of the tilt orientation of the first and second side groups, the overall orientation is also determined by the surface director alignment layer to achieve the desired pretilt angle of the liquid crystal molecules. Should be in the range of 85 ° to 89.5 ° to the surface. However, if only the first side group is reoriented during light irradiation of the polymer compound, the orientation of the first side group is compensated for the fact that the second side group may still be oriented to promote vertical orientation. In order to achieve the desired pretilt of the liquid crystal material (range 85 ° to 89.5 °), the final orientation of the individual first side groups is typically less than 85 ° For example, 80 to 85 °. The final pretilt angle can also be affected by irradiation conditions (including the light irradiation angle α), temperature, ambient atmosphere, and the like. The degree of side group reorientation can be adapted, for example, by adapting the direction of the linearly polarized electromagnetic radiation and / or its wavelength and the exposure time of the light irradiation. However, the results from light irradiation also depend on, for example, the number of photofunctional moieties, the chemical structure of the first and second side groups and the chemical structure of the photofunctional part (ie different benzophenone derivatives) and the structure of the polymer backbone Can do.

  The polymer compound of the present invention has a repeating unit having a first side group bonded thereto, a repeating unit having a second side group bonded thereto, and a repeating unit not sufficiently having the first and second side groups. It may be a random copolymer containing units. The repeating units may be of the same type except for the side groups.

  “Random copolymer” means a polymer comprising at least two or more different monomer units randomly distributed along the length of the polymer backbone. Examples include a first repeating unit having a first side group attached thereto and another repeating unit of the same type but having a second side group attached thereto instead of the first side group. Containing copolymer. Another example is a copolymer comprising a first repeat unit having a first side group attached thereto and a second repeat unit having a second side group attached thereto.

  Random copolymers can be obtained by polymerization of a mixture of at least two different monomer units by methods well known in the art, such as radical addition polymerization.

  The radical polymerization method does not require the polymer product of radical polymerization to be cured, and the alignment layer can be easily formed by simply evaporating the solvent after coating on the substrate, so that the alignment material It is particularly advantageous as a method for producing polymers for use therein. This allows the use of a temperature sensitive substrate, such as a plastic substrate, since no excessive heating is required to produce the alignment layer. Furthermore, since the polymer does not require curing after coating, the total time to form the alignment layer on the substrate is reduced—it is simply a very thin alignment film from a solution containing the polymer compound according to the invention. Coating followed by evaporation of the solvent. Moreover, thanks to the small amount of solvent used, this method is low cost and more environmentally friendly. In addition, the use of a method of radical polymerizing a blend of many different monomers can be easily polymerized to give the desired copolymer compound.

  In an embodiment of the present invention, the polymer compound includes a first type of repeating unit (also referred to as “first repeating unit”) and a second type of repeating unit (also referred to as “second repeating unit”). Wherein the first repeat unit is different from the second repeat unit. For example, in an embodiment of the present invention, the polymer compound comprises a first repeat unit that may be at least some functionalized with a first side group, and further at least some functionalized with a second side group. It may be a random copolymer comprising a second repeating unit that may be present. Alternatively, the first and second repeat units can be functionalized with first and second functional groups. In other embodiments of the invention, only one of the first and second repeat units may be functionalized with a first side group and / or a second side group.

  Typically, the first repeat unit and / or the second repeat unit is independently at least one of maleimide, acrylate, methacrylate, vinyl, styrene and N-vinyl lactam monomers, and derivatives thereof, and mixtures thereof. Can be derived from

  For example, in an embodiment of the present invention, the polymeric compound comprises a first repeat unit of maleimide functionalized with either a first side group, or a second side group, or a third or further side group. And a random copolymer containing a second repeating unit of N-vinylpyrrolidone.

  For example, in an embodiment of the present invention, the polymer compound is a random copolymer comprising a first repeat unit of an acrylate functionalized with a first side group, or a second side group, or a third or further side group. It is.

（式中、Ｌ_１は第一繰返し単位に結合した連結基を表し、該Ｌ_１は３乃至３０結合原子、例えば５乃至１５結合原子を含み；
Ｒ_１は、水素原子、ハロゲン原子、炭素原子数１乃至２０のアルキル基、置換された炭素原子数１乃至２０のアルキル基、炭素原子数１乃至２０のアルコキシ基、置換された炭素原子数１乃至２０のアルコキシ基、炭素原子数１乃至２０のアルケニル基、置換された炭素原子数１乃至２０のアルケニル基、炭素原子数１乃至２０のアルキニル基、置換された炭素原子数１乃至２０のアルキニル基、炭素原子数１乃至２０のアミノアルキル基、置換された炭素原子数１乃至２０のアミノアルキル基、典型例としてはハロゲン原子、又は炭素原子数１乃至１１のアルキル基もしくは炭素原子数１乃至１１のアルコキシ基を表し；
ｎは０乃至４であり；
Ｒ_２及びＲ_３は、互いに独立して、水素原子、ハロゲン原子、炭素原子数１乃至３のアルキル基、置換された炭素原子数１乃至３のアルキル基、炭素原子数１乃至３のアルコキ
シ基、置換された炭素原子数１乃至３のアルコキシ基、炭素原子数１乃至３のアミノアルキル基、置換された炭素原子数１乃至３のアミノアルキル基を表す。）を有し得る。 According to an embodiment of the invention, the first side group is also denoted by S ¹ and is advantageously of the following formula (I):

(Wherein, L ₁ represents a linking group attached to the first repeat unit, wherein L ₁ comprises 3 to 30 bonding atoms, for example, 5 to 15 bonding atoms;
R ₁ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a substituted carbon atom of 1 Alkyl group having 1 to 20 carbon atoms, Alkenyl group having 1 to 20 carbon atoms, Substituted alkenyl group having 1 to 20 carbon atoms, Alkynyl group having 1 to 20 carbon atoms, Alkynyl having 1 to 20 carbon atoms substituted Groups, aminoalkyl groups having 1 to 20 carbon atoms, substituted aminoalkyl groups having 1 to 20 carbon atoms, typically halogen atoms, alkyl groups having 1 to 11 carbon atoms, or 1 to 1 carbon atoms 11 represents an alkoxy group;
n is 0 to 4;
R ₂ and R ₃ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, a substituted alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. And a substituted alkoxy group having 1 to 3 carbon atoms, an aminoalkyl group having 1 to 3 carbon atoms, and a substituted aminoalkyl group having 1 to 3 carbon atoms. ).

（式中、Ｌ_２は、第一繰返し単位に結合した連結基を表し、該Ｌ_２は３乃至３０の連結原子、例えば５乃至１５の連結原子を含み；
ｍは、０又は１であり、
Ｘは、−ＣＯＯ−、−ＣＨ＝ＣＨ−、又は−Ｃ≡Ｃ−を表し；
Ｒ_４は、水素原子、ハロゲン原子、炭素原子数１乃至２０のアルキル基、置換された炭素原子数１乃至２０のアルキル基、炭素原子数１乃至２０のアルコキシ基、置換された炭素原子数１乃至２０のアルコキシ基、炭素原子数１乃至２０のアルケニル基、置換された炭素原子数１乃至２０のアルケニル基、炭素原子数１乃至２０のアルキニル基、置換された炭素原子数１乃至２０のアルキニル基、炭素原子数１乃至２０のアミノアルキル基、置換された炭素原子数１乃至２０のアミノアルキル基、典型例としては水素原子、又は炭素原子数１乃至１１のアルキル基もしくは炭素原子数１乃至１１のアルコキシ基を表し；
ｎは、０乃至４であり、
Ｒ_５及びＲ６は、互いに独立して、水素原子、ハロゲン原子、炭素原子数１乃至３のアルキル基、置換された炭素原子数１乃至３のアルキル基、炭素原子数１乃至３のアルコキシ基、置換された炭素原子数１乃至３のアルコキシ基、炭素原子数１乃至３のアミノアルキル基、置換された炭素原子数１乃至３のアミノアルキル基を表す。）を有し得る。 According to an embodiment of the invention, the second side group is also represented by S ² and is advantageously represented by the following general formula (II):

(Wherein, L ₂ represents a linking group attached to the first repeat unit, said L ₂ comprises 3 to 30 linked atoms, for example, 5 to 15 linked atoms;
m is 0 or 1,
X represents —COO—, —CH═CH—, or —C≡C—;
R ₄ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a substituted carbon atom of 1 Alkyl group having 1 to 20 carbon atoms, Alkenyl group having 1 to 20 carbon atoms, Substituted alkenyl group having 1 to 20 carbon atoms, Alkynyl group having 1 to 20 carbon atoms, Alkynyl having 1 to 20 carbon atoms substituted Group, an aminoalkyl group having 1 to 20 carbon atoms, a substituted aminoalkyl group having 1 to 20 carbon atoms, typically a hydrogen atom, an alkyl group having 1 to 11 carbon atoms, or 1 to 1 carbon atom 11 represents an alkoxy group;
n is 0 to 4,
R ₅ and R 6 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, a substituted alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, A substituted alkoxy group having 1 to 3 carbon atoms, an aminoalkyl group having 1 to 3 carbon atoms, and a substituted aminoalkyl group having 1 to 3 carbon atoms; ).

In embodiments of the present invention, L ₁ may contain up to 10 more connecting atoms than L ₂ , for example up to 6 more connecting atoms. The linking groups L ₁ and L ₂ are optionally substituted, saturated or unsaturated hydrocarbon chains such as alkyl groups, alkenyl groups, aryl groups, alkylaryl groups, alkoxy groups or polyether groups, aryloxy groups. Further, it may contain a siloxane chain or the like. For example, L ₁ and L ₂ are each independently an alkyl group having 1 to 30 carbon atoms, a substituted alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or the number of carbon atoms An alkoxy group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, a substituted alkenyl group having 1 to 30 carbon atoms, an alkynyl group having 1 to 30 carbon atoms, a substituted carbon atom having 1 to 30 carbon atoms It may be an alkynyl group, an aminoalkyl group having 1 to 30 carbon atoms, or a substituted aminoalkyl group having 1 to 30 carbon atoms. Typical examples include an alkynyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, such as an alkyl group having 3 to 11 carbon atoms or an alkoxy group having 3 to 11 carbon atoms.

  In an embodiment of the invention, the ratio of the number of first side groups to the number of second side groups in the polymer compound is advantageously 10: 1 to 1: 100, for example 2: 1 to 1:10, For example, it can be 1: 1.

  In an embodiment of the invention, the ratio between the number of first side groups and the total number of first repeating units in the polymer compound can advantageously range from 1: 1 to 1: 100, for example 1:10. .

  The ratio between the number of first and second side groups in the polymer and the ratio between the number of first and / or second side groups relative to the total number of first repeat units is advantageously The overall (tilt) orientation of the side groups can be adapted so that when used as an alignment layer, the liquid crystal molecules of the liquid crystal material can be aligned at the desired pretilt angle. Any proportion will typically depend on the method used for light irradiation, for example depending on the direction of the linearly polarized electromagnetic wave irradiation and / or its wavelength, temperature and / or dose of light irradiation. Let's go. However, any ratio to achieve the desired pretilt can also depend on the individual structure of the first and second side groups.

  In an embodiment of the present invention, the first and / or second repeat unit is typically an alkyl group having 2 to 20 carbon atoms, or a substituted alkyl group having 2 to 20 carbon atoms, such as carbon. It may be functionalized with a third type of side group, which may be an alkyl group of 2 to 11 atoms, for example an alkyl group of 8 carbon atoms. For example, the third side group can comprise an N-alkylmaleimide.

In an embodiment of the present invention, in addition to the first side group and the second side group, the optional polymer compound may further include one or more of the following types of side groups:
- the third kind of side group selected from aliphatic groups and aromatic groups S ^3;
A fourth group of side groups S ⁴ (also referred to herein as anchor side groups) that form pendant side groups capable of anchoring the polymer compound to the substrate;
The fifth species S ⁵ of the side group forming the ion migration inhibiting side group.

The side groups S ³ and S ⁴ can each be bonded to the polymer backbone by a linking group L as described above, if necessary.

  Note that the polymeric compound may include repeat units that do not include any side groups. The inclusion of repeating units of the polymer backbone without side groups attached to the backbone can give rise to regular or irregular spaces between the side groups mentioned above.

Physicochemical properties of polymer compounds according to embodiments of the present invention, such as glass transition temperature T _g , elastic modulus, volume film coherence, film smoothness, wettability, surface energy, etc. Polyethers, siloxanes, or halogenated, such as fluorinated, optionally substituted with branched or straight chain aliphatic and aromatic groups such as alkyl groups, aryl groups or alkylaryl groups, etc. by incorporating in the polymer backbone repeat unit comprising a side group S ³ is selected from an alcohol, it can be adjusted to a desired value.

Typical examples of S ³ side groups are optionally fluorinated, eg perfluorinated, alkyl groups having 1 to 18 carbon atoms, eg alkyl or alcohol groups having 4 to 12 carbon atoms, spacers L includes those groups defined above. For example, an S ³ group consisting of an alkyl chain generally decreases the T _g of the polymer, while an S ³ group consisting of an aryl group generally increases the T _g of the polymer. Side group S ³ is preferably linear. In the embodiment of the present invention, the side group S can contribute to the vertical alignment of the liquid crystal material.

In an embodiment of the present invention, the anchor side groups S ⁴ may preferably be used to anchor the polymer to the underlying substrate. Anchor side groups S ⁴ typically has a functional group at a removed during end or ends of the polymer backbone, have been carbon atoms 2 to 20 optionally substituted, for example, carbon atom number of 2 to 8 The functional group is, for example, but not limited to, a free hydroxyl group on the glass surface or an epoxy group, an amino group, a thiol group derived by preactivation of the substrate surface. Alternatively, a bond such as a covalent bond, an ionic bond, or a hydrogen bond can be formed with a chemical group on the surface of the substrate, such as an isocyano group.

  Non-limiting examples of such functional groups suitable for anchor side groups include amino groups, hydroxy groups, isocyano groups, and glycidyl groups. One skilled in the art will be able to select a suitable functional group for the anchor side group depending on the substrate material.

（式中、Ｚは、ポリマー骨格部分を表し、そしてＬは、好ましくは１乃至１０、例えば１乃至５のスペーサ原子長を有するスペーサ基、例えばアルキルスペーサ基を表す。）に開示されている。 Non-limiting examples of the anchor side group S ⁴ include the following structural formulas (III) to (VI):

Wherein Z represents a polymer backbone and L is preferably a spacer group having a spacer atom length of 1 to 10, for example 1 to 5, for example an alkyl spacer group.

Ion migration inhibiting groups S ^5, when the polymer compound is used as an orientation layer, in order to reduce the concentration of mobile ions in the liquid crystal bulk material, obtained is utilized in the polymer, therefore, conduction of the liquid crystal bulk material Reduce sex. The ion migration inhibiting group is typically a strongly polar group or nonionic group that attracts ions. Examples of ion transfer inhibiting groups are hydroxyl groups and others, including materials known as conventional ion traps such as coronands.

In an embodiment of the present invention, the polymer compound has a glass transition temperature (T _g ) of at least 180 ° C. A polymer with a high Tg results in a more temperature stable liquid crystal alignment.

  FIG. 4 shows a double-sided liquid crystal device according to the present invention. The liquid crystal device 300 includes a first confinement substrate 301 and a second confinement substrate 302 that are spaced apart from each other. In the space between the substrates 301 and 302, the liquid crystal material 303 is disposed between the substrates 301 and 302.

  A surface director alignment layer 304 is disposed on the first substrate 301 in contact with the liquid crystal material 303. Depending on the presence of anchor side groups on the polymer of the present invention, the top director alignment layer 304 can be chemically bonded to the substrate 301.

  The surface director alignment layer 304 includes at least one polymer according to an embodiment of the present invention. Accordingly, the surface director alignment layer 304 promotes homeotropic alignment with a small pretilt of the liquid crystal material 303 at the interface toward the surface director alignment layer 304 at least or close thereto.

  One skilled in the art will recognize that the liquid crystal device 300 of the present invention may include means for generating an electric field in the liquid crystal material 303. The change in electric field typically causes the liquid crystal to re-orientate, i.e., switch the liquid crystal director. For example, such a technique can be represented by a pair of electrodes. According to the embodiment shown in FIG. 4, the first electrode 305 is disposed between the alignment layer 304 and the substrate 301, and the second electrode 307 is disposed on the second substrate 302.

  The surface director alignment layer 304 induces the pretilt alignment of the surface director of the liquid crystal material 303 in the absence of an applied electric field.

  The second alignment layer 306 was disposed between the second substrate and the liquid crystal material 303. This second alignment layer may comprise the polymer of embodiments of the present invention, or alternatively may be other types of alignment layer materials.

  In addition, variations disclosed in the embodiments can be understood and achieved by those skilled in the art from a study of the drawings, the specification, and the appended claims, to the practice of the claimed invention.

  The invention will now be described with reference to the following examples which further illustrate the invention. It should be noted that the examples are provided to illustrate the invention and do not limit the scope of the invention. The scope of the present invention is defined only by the appended claims.

  All examples were performed at room temperature and normal atmospheric conditions, except where otherwise indicated.

Commercially available chemical compounds were used with the following exceptions:
i) N-vinyl-pyrrolidone (NVP) and N-vinyl-caprolactam are passed through aluminum oxide before use to remove added stabilizer,
ii) When dry THF was required, normal THF was dried by passing it through aluminum oxide before use. Active, neutral, Brockman 1.58Å aluminum oxide (CAS 1344-28-1) was used for THF drying and NVP purification.

In all the examples below, standard reactions well known to those skilled in the art were used for the synthesis of the polymers. The polymer alignment material can be produced, for example, by copolymerization of a functionalized maleimide and N-pyrrolidone. The production of these materials and the side groups used are shown below.

N-octylmaleimide (VIII) : Octylamine was dissolved in chloroform and an equivalent of maleic anhydride was added. After stirring for 2 hours at room temperature, the solvent was removed. The amic acid formed was dissolved in acetic anhydride without purification and an equivalent of sodium acetate was added. The mixture was refluxed for 6-8 hours and then the solvent was removed in vacuo. The residue was passed through a short silica gel column using petroleum ether / ethyl acetate 2/1 or 4/1 as eluent. The maleimide was then recrystallized from ethanol or methanol. This procedure works well for amine octyl groups or at least hexadecyl groups. The imides from hexyl groups and shorter ones are liquids and must be more carefully separated by chromatography using the same conditions as described above.

Maleimide (XI): II 4.2 g (9.55 mmol), maleimide 0.93 g (9.55 mol), and triphenyl phosphite 2.5 g (9.55 mmol) were dissolved in 40 mL of dry tetrahydrofuran. 9.55 mmol of diethyl azodicarboxylate (DEAD) (4.4 mL of 40% solution in toluene) was added dropwise to the reaction mixture. The mixture was stirred for 3 hours at room temperature and evaporated to dryness. The residue was taken up in petroleum ether / ethyl acetate 2/1 and purified by chromatography on silica gel. Yield: 2.8 g, 56%. ¹ H NMR (CDCl ₃ , δ, pattern, number of protons; 1.0, t, 3; 1.1-1.63 around m, 20; 1.8, m, 4; 3.5, t, 2 4, t, 2; 4.4, t, 2; 6.7, s, 2; 7.0, d, 2; 7.6, 2d, 4; 8.1, d, 2.

Maleimide (XIII): 6.5 g (13 mmol) of IX, 1.26 g (13 mmol) of maleimide, and 3.4 g (13 mmol) of triphenylphosphine were dissolved in 100 mL of dry tetrahydrofuran. 13 mmol of diethyl azodicarboxylate (5.9 mL of 40% solution in toluene) was added dropwise to the reaction mixture. The mixture was stirred for 3 hours at room temperature and evaporated to dryness. The residue was taken up in toluene / ethyl acetate 4/1 and purified by chromatography on silica gel. Yield: 4.0 g 53%. ¹ H NMR (CDCl ₃ , δ, pattern, proton number; 0.9, t, 3; 1.1-1.6, 3 m; 1.8, m, 4; 3.5, t, 2; 3. 9, t, 2; 4.1, t, 2; 6.7, s, 2; 6.9, 2d, 4; 7.1, d, 2; 8.1, d, 2.

Maleimide (XV): XIV 1.5 g (4 mmol), maleimide 0.40 g (4.1 mmol) and triphenylphosphine 1.13 g (4.1 mmol) are dissolved in 20 mL of dry THF and diethylazodicarboxylate 0.1. 72 g (4.1 mmol) was added as a 2.19 M solution. The reaction mixture was stirred for 5 hours at room temperature. The solvent was removed and the residue was refluxed in petroleum ether / ethyl acetate 2/1 and filtered hot. The solvent was removed under reduced pressure and the residue was recrystallized from methanol to give an impure product. Chromatography using petroleum ether / ethyl acetate 2/1 as the extract gave a low yield of pure product due to losses during the recrystallization experiment. Yield: 0.3 g, 0.6 mmol, 17%. ¹ H NMR (CDCl ₃ , δ, pattern, proton number; 0.9, t, 3; 1.3, −1.7, 3 m, 12; 1.8, m, 4; 3.6, t, 2 4, t, 4; 6.7, s, 2; 6.93, m, 4; 7.45, m, 4.

4- (11-hydroxyundecyloxy) -benzophenone (XX) : 4-hydroxybenzophenone 20 mmol (4 g), 11-bromo-1-undecanol 20 mmol (5 g) and anhydrous potassium carbonate 25 mmol (3.4 g) in 100 mL of butanone Added and heated at 80 ° C. for 6 days. The mixture was filtered hot, the solvent was removed, and the residue was recrystallized from methanol. Yield: 4.8 g (64%). ¹ H NMR (CDCl ₃ , δ, pattern, number of protons; 1.3bs, 12; 1.4-1.6, 2m, 4; 1.8,
m, 2; 3.65, t, 2; 4.05, t, 2; 6.95, d, 2; 7.47, m, 2; 7.58, m, 1; 7.75, d, 2; 7.82, d, 2.

4- (11-maleimidoundecyloxy) -benzophenone (XVI) : XX 1.5 g (4.0 mmol), maleimide 0.40 g (4.1 mmol) and triphenylphosphine 1.13 g (4.1 mmol) in dry THF 20 mL. Dissolved and 0.72 g (4.1 mmol) of diethyl azodicarboxylate was added as a 2.19 M toluene solution. The reaction mixture was stirred overnight at room temperature. The solvent was removed and the residue was taken up in heated petroleum ether / ethyl acetate 2/1 and filtered. The solvent was removed under reduced pressure to an appropriate amount and subjected to column chromatography using petroleum ether / ethyl acetate 2/1 as the extract. Yield: 1.2 g, 67%. ¹ H NMR (CDCl ₃ ): δ, pattern, number of protons: 1.2-1.65, ₃ m, 16; 1.8, m, 2; 3.5, t, 2; 4.05, t, 2 6.7, s, 2; 7, d, 2; 7.47, m, 2; 7.58, m, 1; 7.75, d2; 7.82, d, 2.

XVIII : maleimide XVII 0.3 mmol (150 mg), XVI 0.2 mmol (90 mg), N-octylmaleimide 1.5 mmol (313 mg), N-vinylpyrrolidone 2.0 mmol (222 mg) and 2,2′-azobis (2- 15 mg of methylpropionitrile) (AIBN) was dissolved in 15 mL of benzene. The polymerization was carried out in a 60 ° C. water bath for 18 hours. Purification was carried out by reprecipitation from several mL of chloroform into methanol three times. Yield 66%. Add relative side group proportions according to NMR, consistent with fair proportions. The ratio of the first side group (benzophenone) to the second side group was 2: 3.

11- (4-Benzoylphenoxy) undecylprop-2-enoate) (XIX) : ([4- (11-hydroxyundecoxy) benzophenone] (XX ) 1.84 g (5 mmol) is dissolved in 25 mL of chloroform, and 2 g (28 mmol) of triethylamine was added, the mixture was cooled in an ice bath, and 0.5 g (5.1 mmol) of acryloyl chloride was added via syringe, the mixture was stirred for 2 hours with cooling and 2 at room temperature. The reaction mixture was poured into water and acidified with hydrochloric acid, then the two phases were separated, the aqueous layer was extracted with chloroform, and the combined organic layers were washed with water and brine. The product is evaporated to a silica gel chromatograph using petroleum ether / ethyl acetate 1/2 as the extract. The yield was 1.0 g 47%, and the ¹ H-NMR spectrum was consistent with the structure.

(4-Hexoxyphenyl) 4- (6-prop-2-noyloxyhexoxy) benzoate (XXI) : (4-hexoxyphenyl) 4- (6-hydroxyhexoxy) benzoate 1.6 g (3. 9 mmol), 0.9 g (12.7 mmol) of triethylamine and 0.36 g (4 mmol) of acryloyl chloride were reacted in 25 mL of chloroform. The mixture was stirred overnight. The same work-up procedure as XIX was used, except that petroleum ether / ethyl acetate 4/1 was used as the extract. Yield: 1.14 g 62%. ^{The 1} H-NMR spectrum was consistent with the structure.

Acrylate polymer (XXII) : XXI 140 mg (0.3 mmol), hexyl acrylate 218 mg (1.4 mmol) and AIBN 9 mg (0.06 mmol) were dissolved in 10 mL of benzene. The stabilizer in hexyl acrylate was removed by passing through aluminum oxide. The reaction mixture was degassed by applying vacuum and nitrogen injection 10 times. The stirred mixture was polymerized at 80 ° C. for 18 hours. Then most of the solvent was removed and the residue was precipitated in methanol. The polymer was reprecipitated from chloroform to methanol three times. Yield 0.20 g 41%. 1H-NMR spectrum indicated that the polymer composition was consistent with the proportion of components added. The ratio of the first side group (benzophenone) to the second side group was 1: 1.

High Tg photo alignment material that imparts tilt

XXIII : VA maleimide XV 0.1 mmol (45 mg), benzophenone XVI 0.1 mmol (45 mg), phenylmaleimide 0.3 mmol (52 mg), N-vinylpyrrolidone 0.5 mmol (56 mg) and 2,2′-azobis (2- 4 mg of methylpropionitrile) (AIBN) was dissolved in 4 mL of benzene. The polymerization was carried out in a hot water bath at 60 ° C. for 47 hours. It was purified by recrystallizing twice from several mL chloroform into methanol. Yield 55%. 110 mg. The ratio of the first side group (benzophenone) to the second side group was 2: 3.

XXIV : VA maleimide XV 0.1 mmol (45 mg), benzophenone XVI
0.05 mmol (23 mg), phenylmaleimide 0.35 mmol (60 mg), N-vinylpyrrolidone 0.5 mmol (56 mg) and 2,2′-azobis (2-methylpropionitrile) (AIBN) 4 mg were added to 4 mL of benzene. Dissolved. The polymerization was carried out in a 60 ° C. oil bath for 48 hours. Purification was performed by reprecipitation twice from several mL of chloroform into methanol. Yield 22%, 40 mg. The ratio of the first side group (benzophenone) to the second side group was 1: 1.

General manufacturing method for liquid crystal cells a) Preparation of polymer solution: An alignment layer made from the copolymer of the present invention is coated from a 0.2-5% solution of the copolymer in a solvent such as NMP and PGMEA. The copolymer solution was first filtered through a 0.2 μm filter.
b) Copolymer coating: The copolymer solution is spread on a clean glass substrate with a preformed transparent conductive electrode made of ITO, for example by the spinner method (speed 3000 rps). The substrate is maintained for several hours at room temperature to evaporate the solvent. This process can be shortened if the substrate is maintained at an elevated temperature (eg, 80-120 ° C.).
c) Photo-orientation of the copolymer: UV irradiation of an experimental substrate coated with a light-sensitive copolymer gives a standard U, 5 mW / cm ² linear polarization from an unfiltered high-pressure mercury UV lamp.
It was carried out with a SHIO apparatus (typical UV rough stem USHIO DEEP, model number: UIS-S2511KK-AKB01). The lamp used in the present invention has an effective light wavelength of 250 nm to 320 nm and 365 nm, respectively. The sample was irradiated through a UV filter that cuts all wavelengths below 290 nm. The light polarization direction is in the plane of incidence.
d) Cell manufacture: The experimental liquid crystal cell consists of two substrates assembled in parallel to each other and separated by a distance of several μm. The distance between the substrates is usually fixed by glass or a polymer spacer. The substrates face each other with the surfaces coated with the alignment layer. The cell gap formed by them is filled with liquid crystal by capillary force.
e) Evaluation of the orientation of the copolymer: Evaluation of the orientation of the liquid crystals in the experimental cell, facilitated by an alignment layer made from the copolymer of the present invention, can be carried out using an optical polarization microscope and / or a Muller matrix spectrometer (Muller matrix spectrometer). (I. Dahl, Meas. SCI. Technol. Vol. 12, 1938, 2001).

Preparation for cell and tilt angle studies using compounds XVIII and XXIII as alignment layers
Use of 1% XVIII in PGMEA: 1 wt% XVIII in PGMEA was spin coated onto the substrate (2000 rpm for 30 seconds) and maintained at 100 ° C for 15 minutes. The substrate was irradiated at 45 ° (oblique incidence angle) with linearly polarized UV light (290 nm filter was used to remove UV light below 290 nm). The light polarization was the incident surface. The two substrates produced in this way were assembled into conventional sandwich cells parallel to each other with alignment films covering the surfaces facing each other. The substrate was arranged with a gap of about 4 μm filled with liquid crystal. The substrate was accurately placed so that the irradiation direction of the substrate was non-parallel, forming so-called non-parallel liquid crystal cells. A liquid crystal material, MLC6608 (Merck) (Δε <0) was injected into the cell gap at an isotropic temperature.

  It was found that the pretilt of the liquid crystal molecules increased with the exposure time (see Table 1).

Use of 1% XXIII in PGMEA: 1 wt% XXIII in PGMEA was spin coated onto the substrate (2000 rpm for 30 seconds) and maintained at 100 ° C for 15 minutes. The substrate was irradiated at 45 ° (oblique incidence angle) with linearly polarized UV light (290 nm filter was used to remove UV light below 290 nm). The light polarization was the incident surface. The two substrates produced in this way were assembled into conventional sandwich cells parallel to each other with alignment films covering the surfaces facing each other. The substrate was placed with a gap of about 4 μm filled with liquid crystal. The substrate was correctly placed so that the irradiation direction of the substrate was non-parallel, forming so-called non-parallel liquid crystal cells. A liquid crystal material, MLC6608 (Merck) (Δε <0) was injected into the cell gap at an isotropic temperature.

  Again, it was found that the tilt of the liquid crystal molecules increased with exposure time (see Table 2).

  The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the other hand, many modifications and variations are possible within the scope of the appended claims.

  In the claims, the term “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The fact that certain measures are recited in mutually different dependent claims does not indicate that these measures cannot be used to advantage.

Claims (18)

A surface director alignment layer comprising at least one polymer compound capable of promoting vertical alignment of liquid crystal molecules with respect to the alignment layer surface,
The polymer compound is:
A polymer backbone (209) comprising repeating units (204, 205);
A first side group (206) attached to at least some of the repeating units, the first side group comprising a photofunctional moiety (208) comprising at least one benzophenone moiety or derivative thereof;
A second side group attached to at least some該繰-back unit (207); end to the repetitive unit - ON bond, remarkable shape anisotropy capable of inducing homeotropic alignment of the liquid crystal material Second side group having (207)
Including
The first side group is represented by the following general formula (I):

(Wherein L ₁ represents a linking group bonded to the repeating unit, and L ₁ contains 5 to 15 bonding atoms;
R ₁ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a substituted carbon atom of 1 Alkyl group having 1 to 20 carbon atoms, Alkenyl group having 1 to 20 carbon atoms, Substituted alkenyl group having 1 to 20 carbon atoms, Alkynyl group having 1 to 20 carbon atoms, Alkynyl having 1 to 20 carbon atoms substituted A group, an aminoalkyl group having 1 to 20 carbon atoms, or a substituted aminoalkyl group having 1 to 20 carbon atoms;
n is 0 to 4,
R ₂ and R ₃ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, a substituted alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. Represents a substituted alkoxy group having 1 to 3 carbon atoms, an aminoalkyl group having 1 to 3 carbon atoms, and a substituted aminoalkyl group having 1 to 3 carbon atoms. )
The second side group has the following general formula (II):

(Wherein L ₂ represents a linking group bonded to the repeating unit, and L ₂ contains 5 to 15 linking atoms;
m is 0 or 1,
X represents —COO—, —CH═CH—, or —C≡C—,
R ₄ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a substituted alkyl group having 1 to 20 carbon atoms, and 1 to 20 carbon atoms. Alkoxy groups, substituted alkoxy groups having 1 to 20 carbon atoms, alkenyl groups having 1 to 20 carbon atoms, substituted alkenyl groups having 1 to 20 carbon atoms, carbon An alkynyl group having 1 to 20 carbon atoms, a substituted alkynyl group having 1 to 20 carbon atoms, an aminoalkyl group having 1 to 20 carbon atoms, a substituted carbon atom having 1 to Represents an aminoalkyl group having 20 carbon atoms,
n is 0 to 4,
R ₅ and R ₆ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, a substituted alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. Represents a substituted alkoxy group having 1 to 3 carbon atoms, an aminoalkyl group having 1 to 3 carbon atoms, and a substituted aminoalkyl group having 1 to 3 carbon atoms. )
Surface director alignment layer.   The surface director alignment layer of claim 1, wherein the photofunctional moiety is photoreactive and capable of photocrosslinking. The surface director alignment layer according to claim 1, wherein the L ₁ includes a maximum of 10 linking atoms more than the L ₂ . L ₁ contains at most 6 linking atoms more than L ₂ , and R ₁ represents a hydrogen atom or a halogen atom, and R ₄ represents an alkyl group or carbon atom having 3 to 6 carbon atoms. The surface director alignment layer according to claim 1 or 2, which represents an alkoxy group of formulas 3 to 6. L ₁ and L ₂ are each independently an alkyl group having 5 to 15 carbon atoms, a substituted alkyl group having 5 to 15 carbon atoms, an alkoxy group having 5 to 15 carbon atoms, or a substituted carbon. An alkoxy group having 5 to 15 atoms, an alkenyl group having 5 to 15 carbon atoms, a substituted alkenyl group having 5 to 15 carbon atoms, an alkynyl group having 5 to 15 carbon atoms, a substituted carbon atom having 5 to 15 carbon atoms The surface director alignment layer according to any one of claims 1 to 3, which represents a 15 alkynyl group, an aminoalkyl group having 5 to 15 carbon atoms, or an aminoalkyl group having 5 to 15 carbon atoms.   6. The ratio of the number of the first side groups to the number of the second side groups in the polymer compound is in the range of 10: 1 to 1: 100. 6. The surface director alignment layer described in 1.   The ratio of the number of said 1st side groups and the total number of the said repeating unit in the said polymer compound exists in the range of 1: 1 thru | or 1: 100, In any one of Claims 1 thru | or 6. The surface director alignment layer as described.   8. The repeat unit of any one of claims 1 to 7, wherein the repeat unit comprises a first repeat unit selected from maleimide, acrylate, methacrylate, vinyl, styrene, N-vinyl lactam monomers, and derivatives thereof, and mixtures thereof. A surface director alignment layer according to claim 1. The first repeating unit represents maleimide, L ₁ represents an alkoxy group having 11 carbon atoms, R ₁ , R ₂ and R ₃ represent a hydrogen atom, and L ₂ and R ₄ represent an alkoxy group having 6 carbon atoms. 9. R ₅ represents a hydrogen atom or an N-alkylamide group, R6 represents a hydrogen atom or an N-alkylamide, m is 1, and X represents —COO—. Surface director alignment layer. The first repeating unit represents an acrylate, L ₁ represents an alkoxy group having 11 carbon atoms, R ₁ , R ₂ and R ₃ represent a hydrogen atom, and L ₂ and R ₄ represent an alkoxy group having 6 carbon atoms. 9. R ₅ represents a hydrogen atom or an N-alkylamide group, R6 represents a hydrogen atom or an N-alkylamide group, m is 1, and X represents —COO—. Surface director alignment layer. The repeating unit is a second type of repeating unit selected from at least one of maleimide, acrylate, methacrylate, vinyl, styrene, N-vinyl lactam monomer or mixtures thereof, and derivatives thereof, and mixtures thereof. Including
The second type of repeating unit is different from the first repeating unit, and at least some of the second type of repeating unit is functionalized with the first side group and / or the repeating unit. At least some of the second type of units are functionalized with said second side group;
The surface director alignment layer according to claim 8. At least one confinement substrate (301, 302);
A liquid crystal bulk material (303); and a surface director alignment layer (304) according to any one of claims 1 to 11 disposed between the at least one confining substrate and the liquid crystal bulk material. The liquid crystal molecules contained in the liquid crystal bulk material are in contact with the surface of the liquid crystal bulk material, forming a desired pretilt angle with respect to the surface of the surface director alignment layer in the absence of an applied electric field. The surface director alignment layer comprising:
A liquid crystal device (300) comprising:   The liquid crystal device according to claim 12, wherein the pretilt angle can be adjusted by light irradiation of the surface director alignment layer.   The liquid crystal device according to claim 12, wherein the pretilt angle is in a range of 85 ° to 89.5 ° with respect to a plane of the surface director alignment layer. Preparing a substrate;
Providing a surface director alignment layer according to any one of claims 1 to 11 on the surface of the substrate; and at an angle of incidence in the range of 1 ° to 89 ° with respect to the normal of the substrate. step a electromagnetic radiation becomes linearly polarized in the incidence plane, and irradiating said surface-director alignment layer using the electromagnetic radiation having a wavelength in the range of 200nm to 400 nm,
including,
Method of photo-alignment of surface director alignment layer. Preparing a substrate;
Providing a first electrode layer on the substrate;
Preparing a surface director alignment layer according to any one of claims 1 to 11 on the surface of the first electrode layer;
A electromagnetic radiation at an incident angle in the range of 1 ° to 89 ° to the normal of the substrate, becomes linearly polarized in the incidence plane, and, using the electromagnetic radiation having a wavelength in the range of 200nm to 400nm Irradiating the surface director alignment layer; and
Aligning the liquid crystal material in contact with the alignment layer;
The manufacturing method of the liquid crystal device of Claim 12 containing this.   Use of a surface director alignment layer according to any one of claims 1 to 11 for a liquid crystal device.   A display comprising the liquid crystal device according to claim 12.

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