KR20130082475A - Composition for photo-aligning layer - Google Patents

Abstract

PURPOSE: A photo aligning layer composite is provided to freely manufacture a liquid crystal film indicating a matter property proper for a purpose by adjusting an aligning direction of a liquid crystal. CONSTITUTION: A photo aligning substance of a photo aligning layer composite is an azo compound, a stilbene compound, a cyclobutane-tetracarboxylic dianhydride, aromatic polysilane, aromatic polyester, polystyrene, a cinnamate compound, a coumarin compound, a cinnamamide compound, a tetrahydrophthalimide compound, a maleimide compound, a benzophenone compound, a diphenylacetylen compound, a chalconyl compound, an anthracenyl compound, a benzoate compound, a benzoamide compound, a methacrylamidoaryl methacrylate compound, or a spiropyran compound. A polarity functional group of the composite having a vertical aligning property is acrylyl or methacryloyl.

Description

Composition for photo-alignment layer {Composition for photo-aligning layer}

The present application relates to a composition for a photoalignment layer, a substrate for a liquid crystal film, a liquid crystal film, a method for producing a liquid crystal film, and a liquid crystal display.

The liquid crystal compounds may be classified into rod type liquid crystals and discotic liquid crystals depending on their form. If the optical axis is defined as a direction in which no phase difference occurs upon incidence of linearly polarized light, in the case of a rod-shaped liquid crystal, the optical axis is parallel to the long axis direction of the liquid crystal and the optical axis of the discotic liquid crystal. Becomes parallel to the minor axis direction of the liquid crystal.

The alignment of the rod-shaped liquid crystals can be conventionally classified into homogeneous alignment, homeotropic alignment, tilted alignment, spray alignment, cholesteric alignment, and the like. Planar alignment is a case where the optical axis of a liquid crystal is parallel to a film plane, and vertical alignment is a case where the optical axis of a liquid crystal is perpendicular to a film plane. The tilted orientation is when the optical axis of the liquid crystal forms an angle between more than 0 degrees and less than 90 degrees with the plane of the film, and the spray orientation is continuously changed in at least a range within 0 to 90 degrees with the plane of the film. This is the case. In addition, the cholesteric orientation is a case where the optical axis is parallel to the plane of the film and the optical axis is rotating clockwise or counterclockwise when viewed in the normal direction of the film plane.

In the case of the vertical alignment liquid crystal may be used as a retardation film or a viewing angle compensation film in a liquid crystal display (LCD) of various modes, it can be applied to various applications. Thus, for example, Patent Documents 1 to 4 describe a method for forming a vertically aligned liquid crystal. However, the conventional system has many problems, such as the difficulty of controlling the alignment angle of the vertically aligned liquid crystal.

U.S. Patent 6,816,218 European Patent No.1376163 United States Patent Application Publication No. 200600278851 Japanese Laid-Open Patent No. 2006-126757

The present application provides a composition for a photoalignment layer, a substrate for a liquid crystal film, a liquid crystal film, a method for producing a liquid crystal film, and a liquid crystal display.

The present application relates to a composition for a photoalignment layer. The term photoalignment layer composition refers to a composition used to form the photoalignment layer. For example, the photoalignment layer may be formed by coating the composition or a coating solution prepared using the composition. The composition for the photoalignment layer may be used to form a vertically oriented photoalignment layer. The vertically oriented photoalignment layer may refer to a photoalignment layer exhibiting properties capable of vertically aligning the liquid crystal compound through appropriate treatment, for example, irradiation of light.

The composition for the photoalignment layer may include a photoalignment material. The term photo-orientation material is aligned in a predetermined direction through irradiation of light or the like, and in the aligned state, the adjacent liquid crystals can be oriented in a predetermined direction through interaction such as anisotropic interaction. Means a compound. Such photo-orientation materials may be present in alignment to have directivity in the alignment layer described below. The photo-orientation material may be a monomolecular compound, a monomeric compound, an oligomeric compound or a high molecular compound.

The photo-alignment material may be a compound comprising a photosensitive moiety. Photo-alignment materials that can be used for the orientation of the liquid crystal compound are variously known. Photo-alignment materials include, for example, compounds aligned by trans-cis photoisomerization; Compounds that are aligned by photo-destruction such as chain scission or photo-oxidation; Compounds that are aligned by photo-crosslinking or photopolymerization such as [2 + 2] cycloaddition, [4 + 4] addition cyclization or photodimerization; A compound aligned by photo-Fries rearrangement or a compound aligned by ring opening / closure reaction can be used. Examples of the compounds that are aligned by trans-cis photoisomerization include azo compounds such as sulfonated diazo dye or azo polymer, stilbenes, etc. Examples of the compound which is aligned by photolysis include cyclobutane-1,2,3,4-tetracarboxylic dianhydride, aromatic polysilane or polyester, polystyrene or polyimide, and the like. The compounds that are aligned by photo-crosslinking or photopolymerization include cinnamate compounds, coumarin compounds, cinnamamide compounds, tetrahydrophthalimide compounds, maleimide compounds, (Hereinafter, referred to as an anthracenyl compound) having a chalconyl residue (hereinafter, referred to as a chalcone compound) or an anthracenyl residue (hereinafter referred to as an anthracenyl compound) as a benzophenone compound or a diphenylacetylene compound or a photo- Examples of the compounds that are aligned by optical freeze rearrangement include aromatic compounds such as benzoate compounds, benzoamide compounds, and methacrylamidoaryl methacrylate compounds, Examples of the compounds to be aligned by the ring-opening / ring closing reaction include spiropyran compounds and the like A [4 + 2] π electron system ([4 + 2] π electronic system), but may be exemplified by compounds such as sorting by a ring opening / ring-closure reaction of, without being limited thereto.

The photo-orientation material may be a monomolecular compound, a monomeric compound, an oligomeric compound or a high molecular compound, or may be in the form of a blend of the photo-orientation material and the polymer. In the above, the oligomeric or polymeric compound may have a residue derived from the photo-alignment material or the photosensitive residue described above in the main chain or in the side chain.

Polymers having a moiety or photosensitive moiety derived from a photo-orientation material or that may be mixed with the photo-alignment material include polynorbornene, polyolefin, polyarylate, polyacrylate, poly (meth) acrylate, poly Examples include mead, poly (amic acid), polymaleimide, polyacrylamide, polymethacrylamide, polyvinyl ether, polyvinyl ester, polystyrene, polysiloxane, polyacrylonitrile or polymethacrylonitrile It may be, but is not limited thereto.

Examples of the polymer that can be contained in the oriented compound include polynorbornene cinnamate, polynorbornene alkoxy cinnamate, polynorbornene allyloyloxycinnamate, polynorbornene fluorinated cinnamate, polynorbornene chlorinated cinnamate, or Polynorbornene dicinnamate, and the like, but are not limited thereto. When the oriented compound is a polymeric compound, the compound may have a number average molecular weight of, for example, from about 10,000 g / mol to about 500,000 g / mol, but is not limited thereto.

The composition for the photoalignment layer may include a vertically oriented polar functional group together with the photoalignment material. The term vertically oriented polar functional groups may include all kinds of functional groups capable of imparting the vertical alignment force to the alignment layer, for example, to vertically align the liquid crystal compound through interaction with the liquid crystal compound. As such a functional group, an acryloyl group, a methacryloyl group, etc. can be illustrated. For example, the vertically oriented polar functional group may be included in the composition by being bonded to the above-described photo-orienting material or bonded to the polar binder described later. The proportion of the vertically oriented polar functional groups in the photo-alignment layer composition is not particularly limited so long as the alignment layer formed by the composition is controlled to exhibit the vertical orientation force, and the ratio is the polarity or the desired vertical orientation force represented by the functional group. Subject to change.

In one example, the composition may include the photo-alignment material and the polar binder. In this case, the vertically oriented polar functional group may be introduced into the polar binder. As the polar binder, for example, an acrylate compound or the like can be used. As the acrylate compound, a monofunctional or polyfunctional compound may be used. As used herein, the term consistency means a compound including one of the aforementioned polar functional groups, for example, acryloyl group or methacryloyl group, and polyfunctionality refers to two or more functional groups, for example, two to eight groups. Or it may mean a compound containing about 2 to about 6. As said acrylate compound, methyl (meth) acrylate, ethyl (meth) acrylate, N, N- dimethylaminoethyl (meth) acrylate, or 2- (2-oxo- imidazolidinyl) ethyl (meth) Alkyl (meth) acrylates such as acrylate and the like; Hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate or hydroxypropyl (meth) acrylate; Alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate and the like; Carboxyalkyl (meth) acrylates such as carboxyethyl (meth) acrylate; Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipenta Risthritol hexa (meth) acrylate, triglycerol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, 1 , 6-hexanediol di (meth) acrylate, glycerol di (meth) acrylate, tris [2- (acryloyloxy) ethyl] isocyanurate, urethane acrylate, glycerol 1,3-diglycerol di Polyfunctional acrylates such as (meth) acrylate or tri (propylene glycol) glycerol diacrylate and the like, oligomeric or polymeric compounds derived therefrom It may be illustrated, but is not limited thereto. In addition, as the kind of the polar binder, compounds other than those mentioned above may be used as long as they are combined with the photo-alignment material to impart the desired vertical alignment force to the alignment layer. When the composition for the photo-alignment layer includes a polar binder, the polar binder is 30 parts by weight to 100 parts by weight, 30 parts by weight to 90 parts by weight, 30 parts by weight to 80 parts by weight, 30 parts by weight with respect to 100 parts by weight of the photo-alignment material. It may be included in the ratio of parts to 70 parts by weight or 40 parts by weight to 60 parts by weight. The ratio of the polar binder can be adjusted as above to impart appropriate vertical alignment force to the alignment layer. Unless otherwise specified, the unit weight portion in the present specification may mean a weight ratio between the components.

The composition for the photo-alignment layer may further include a radical initiator, for example, an optical radical initiator. As a radical initiator, an alpha-hydroxy ketone compound, an alpha-amino ketone compound, a phenyl glyoxylate compound, an oxime ester compound, etc. can be illustrated. The proportion of the reactive compound in the composition is not particularly limited and may be appropriately adjusted in view of the desired effect.

The composition for the photo-alignment layer may further include any additives known in the art, for example, a solvent, a surfactant, or a liquid crystal compound, etc., in addition to the above components.

The present application also relates to a substrate, for example a substrate for a liquid crystal film. The term substrate for a liquid crystal film may mean a substrate used to form a liquid crystal film. Exemplary the substrate, the base film; And an alignment layer formed on the substrate. The alignment layer may be a vertical alignment layer, that is, an alignment layer capable of vertically aligning the liquid crystal compound. The alignment layer may include the composition for the photoalignment layer described above. As previously described, the photo-alignment material may be present in an aligned state in the alignment layer. This alignment can be performed, for example, by irradiating the alignment layer with light as described below.

The base film contained in a board | substrate may be an optically isotropic film or an optically anisotropic film, for example, a retardation film, a viewing angle compensation film, etc., and may be a film with a polarizing function, such as a polarizing plate, a polarizer, etc.

The base film may be, for example, a glass film, a plastic film, or a liquid crystal film. Examples of the plastic film include cellulose resin films such as triacetyl cellulose (TAC) or diacetyl cellulose (DAC); Olefin films such as cyclo olefin polymer (COP), polyethylene (PE) or polypropylene (PP); Acrylic films such as poly (methyl methacrylate); PC (polycarbonate) films; polyvinyl alcohol (PVA) films; poly ether sulfone (PES) films; polyetheretherketon (PEEK) films; polyetherimide (PEI) films; polyethylenemaphthatlate (PEN) films A polyester film such as polyethylene terephtalate (PET) film, a polyimide (PI) film, a polysulfone (PSF) film, or a fluororesin film, etc. The films may be prepared by a conventional film production method. If necessary, the film may be provided with optical anisotropy by uniaxial or biaxial stretching or contraction, or may be optically isotropic, and as the base film, a liquid crystal film known in the art may be used if necessary. .

An orientation layer is formed on a base film. 1 shows an exemplary such substrate comprising an exemplary base film 10 and an alignment layer 20 formed thereon. The alignment layer may contain the composition for photoalignment layers described above. In the alignment layer, the photo-alignment material may exist in a state aligned in a predetermined direction, and the alignment layer may have a vertical alignment force, that is, a property of vertically aligning the liquid crystal compound. Such an alignment layer may be prepared by, for example, irradiating light after coating and drying the composition for the photoalignment layer or the coating solution prepared using the same, as in the manner described below.

The present application also relates to a liquid crystal film. An exemplary liquid crystal film may include a vertical alignment layer and a vertical alignment liquid crystal layer present on the vertical alignment layer. The vertically aligned liquid crystal layer may include the composition for the photoalignment layer described above. The photo-orientation material in the vertical alignment layer may be aligned in a predetermined direction. The liquid crystal film can be produced, for example, by forming a vertically aligned liquid crystal layer on the alignment layer of the substrate for a liquid crystal film described above.

The term vertically aligned liquid crystal layer may mean a layer in which at least some liquid crystal present in the liquid crystal layer is homeotropically aligned. For example, the vertically aligned liquid crystal layer has a plane phase difference of 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, 5 nm or less, 4 nm or less, 3 nm or less, or about 2 nm or less. It may also mean a liquid crystal layer of about 0.5 nm or more, about 0.7 nm or more, about 1 nm or more, or about 1.2 nm or more. In addition, the vertically aligned liquid crystal layer may mean a liquid crystal layer having a thickness retardation of 50 nm or more, 60 nm or more, 70 nm or more, 80 nm or more, or 90 nm or more. The upper limit of the thickness direction phase difference of a liquid crystal layer is not specifically limited above. That is, the thickness direction retardation may be freely adjusted by, for example, adjusting the type of liquid crystal or adjusting the thickness of the liquid crystal layer in consideration of the application of the liquid crystal layer. For example, the thickness direction retardation may be about 500 nm or less.

In the present specification, the planar phase difference Rin of the liquid crystal layer is calculated by the following formula 1, and the phase difference Rth in the thickness direction is calculated by the following formula 2.

[Equation 1]

Rin = d × (Nx-Ny)

[Equation 2]

Rth = d × (Nz-Ny)

In Equations 1 and 2, Rin is a plane phase difference, Rth is a phase difference in the thickness direction, d is a thickness of the liquid crystal layer, and Nx, Ny, and Nz are refractive indexes in the x, y, and z axis directions of the liquid crystal layer, respectively.

In the above, x-axis, for example, as shown in Figure 2, means one direction on the plane of the liquid crystal layer 100, y-axis means the direction on the plane perpendicular to the x-axis, z-axis, It may mean a direction of a normal of the plane formed by the x-axis and the y-axis, for example, the thickness direction of the liquid crystal layer 100. In one example, the x axis may be a direction parallel to a slow axis of the liquid crystal layer, and the y axis may be a direction parallel to a fast axis of the liquid crystal layer. Unless otherwise specified, the term refractive index herein is a refractive index for light of about 550 nm wavelength.

In one example, the liquid crystal layer may include a region in which vertically oriented liquid crystals exist and a region in which spray oriented liquid crystals exist. In one example, the region in which the spray-oriented liquid crystal is present may be in a region in contact with the alignment layer of the liquid crystal layer. As described later, when polarized light, for example, linearly polarized light is irradiated to the alignment layer formed by the composition for the photo-alignment layer, and the vertical alignment liquid crystal is oriented thereon, the liquid crystal present in the interface portion in contact with the alignment layer. Is spray-oriented and the liquid crystal is orientated vertically in the other area | region. When the alignment layer is used, the thickness of the region in which the spray-oriented liquid crystal is present in the structure is very small, so that the phase retardation of the entire liquid crystal layer may be represented as a very small value as described above. 3 is a conceptual view of the shape of the liquid crystal layer in which the liquid crystal (the rod-shaped ellipsoid on the drawing) adjacent to the surface 300 of the liquid crystal layer in contact with the alignment layer as described above is spray-oriented and the liquid crystal in the remaining area is vertically aligned. The figure shows. In particular, in the case of using the alignment layer, the alignment of the vertically aligned liquid crystal can be easily adjusted according to the purpose according to the irradiation direction of the polarized light as described later.

The kind of vertically oriented liquid crystals included in the liquid crystal layer is not particularly limited, and any conventionally known vertically oriented liquid crystal compound or liquid crystal compound capable of spray alignment may be used. In one example, the vertically aligned liquid crystal compound may be a polymerizable liquid crystal compound. Such liquid crystal compounds may be polymerized in a vertically aligned state to form a liquid crystal layer. As used herein, the term polymerizable liquid crystal compound may mean a compound including a moiety capable of exhibiting liquid crystal, for example, a mesogen skeleton and the like, and also including one or more polymerizable functional groups. The liquid crystal layer may further include a polymerizable liquid crystal compound in a non-polymerized state, or may further include a known additive such as a polymerizable non-liquid crystal compound, a stabilizer, a non-polymerizable non-liquid crystal compound, or an initiator.

The polymerizable liquid crystal compound contained in the liquid crystal layer may contain a polyfunctional polymerizable liquid crystal compound and / or a monofunctional polymerizable liquid crystal compound.

The term polyfunctional polymerizable liquid crystal compound may mean a compound including two or more polymerizable functional groups in the liquid crystal compound. In one example, the multifunctional polymerizable liquid crystal compound has 2 to 10, 2 to 8, 2 to 6, 2 to 5, 2 to 4, 2 to 3 polymerizable functional groups Or two. In addition, the term monofunctional polymerizable liquid crystal compound may mean a compound including one polymerizable functional group among the liquid crystal compounds.

For example, the polymerizable liquid crystal compound may be a compound represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, A is a single bond, -COO- or -OCO-, and R ₁ to R ₁₀ are each independently hydrogen, halogen, alkyl group, alkoxy group, alkoxycarbonyl group, cyano group, nitro group, -OQP or A substituent of Formula 2 or a pair of two adjacent substituents of R ₁ to R ₅ or a pair of two adjacent substituents of R ₆ to R ₁₀ are connected to each other to form a benzene substituted with -OQP, wherein R ₁ to At least one of R ₁₀ is -OQP or a substituent of the formula (2) or R ₁ to R ₅ Of adjacent two substituents or at least one pair of two adjacent substituents of R ₆ to R ₁₀ are connected to each other to form a benzene substituted with -OQP, wherein Q is an alkylene group or an alkylidene group, and P Is a polymerizable functional group such as an alkenyl group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group or a methacryloyloxy group.

[Formula 2]

And R ₁₁ to R ₁₅ are each independently hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group or -OQP, The pair of adjacent two substituents R ₁₁ to R ₁₅ are connected to each other to form benzene substituted with -OQP, wherein at least one of R ₁₁ to R ₁₅ is -OQP, or two adjacent R ₁₁ to R ₁₅ P is an alkylene group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, or a methacryloyl group. A diacrylate group, a acryloyloxy group or a methacryloyloxy group.

In Formulas 1 and 2, two adjacent substituents may be linked to each other to form a benzene substituted with -OQP, which may mean that two adjacent substituents are connected to each other to form a naphthalene skeleton substituted with -OQP as a whole. .

"-" On the left side of B in Formula 2 may mean that B is directly connected to benzene of Formula 1.

The term single bond in the formulas (1) and (2) means a case where no separate atom is present in the moiety represented by A or B. For example, when A is a single bond in Formula 1, benzene on both sides of A may be directly connected to form a biphenyl structure.

As the halogen in the formula (1) and (2), for example, chlorine, bromine or iodine and the like can be exemplified.

As used herein, unless otherwise specified, the term alkyl group means a straight or branched chain alkyl group having, for example, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Alternatively, for example, it may mean a cycloalkyl group having 3 to 20 carbon atoms, 3 to 16 carbon atoms, or 4 to 12 carbon atoms. The alkyl group may be optionally substituted by one or more substituents.

The term alkoxy group used herein may mean, for example, an alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, unless otherwise specified. The alkoxy group may be linear, branched or cyclic. In addition, the alkoxy group may be optionally substituted by one or more substituents.

In addition, in the present specification, the term alkylene group or alkylidene group may mean, for example, an alkylene group or alkylidene group having 1 to 12 carbon atoms, 4 to 10 carbon atoms or 6 to 9 carbon atoms, unless otherwise specified. The alkylene group or alkylidene group may be, for example, straight-chain, branched-chain or cyclic. In addition, the alkylene group or the alkylidene group may be optionally substituted with one or more substituents.

In the present specification, unless otherwise specified, for example, an alkenyl group may mean an alkenyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms. . The alkenyl group may be, for example, linear, branched or cyclic. In addition, the alkenyl group may be optionally substituted with one or more substituents.

In Formulas 1 and 2, P may be, for example, acryloyl group, methacryloyl group, acryloyloxy group or methacryloyloxy group, may be acryloyloxy group or methacryloyloxy group, and in another example It may be an acryloyloxy group.

Examples of the substituent which may be substituted in the specific functional group in the present invention include alkyl groups, alkoxy groups, alkenyl groups, epoxy groups, oxo groups, oxetanyl groups, thiol groups, cyano groups, carboxyl groups, acryloyl groups, methacryloyl groups, Acryloyloxy group, methacryloyloxy group, aryl group, and the like, but the present invention is not limited thereto.

The -OQP, which may be present in at least one of the formulas (1) and (2) or the moiety of the formula (2), may for example be present at the position of R ₃ , R ₈ or R ₁₃ . In addition, the substituents connected to each other to constitute benzene substituted with -OQP may be, for example, R ₃ and R ₄ or R ₁₂ and R ₁₃ . Further, substituents other than -OQP or residues of the formula (2) or substituents other than the substituents connected to each other to form benzene in the compound of the formula (1) or the formula (2), for example, hydrogen, halogen, straight chain of 1 to 4 carbon atoms Or an alkoxycarbonyl group including a branched alkyl group, a straight or branched alkoxy group having 1 to 4 carbon atoms, a cycloalkyl group having 4 to 12 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and in another example Alkoxycarbonyl group or cyano group including chlorine, a linear or branched alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 4 to 12 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a straight or branched chain alkoxy group having 1 to 4 carbon atoms Can be.

In addition to the polymerizable liquid crystal compound, the liquid crystal layer may further include a known additive commonly used in the manufacture of a liquid crystal film, for example, a surfactant, a radical initiator, and the like.

The thickness of the liquid crystal layer is not particularly limited and can be appropriately selected in consideration of, for example, a phase difference in the desired thickness direction.

The present application also relates to a method for producing a liquid crystal film. An exemplary manufacturing method may include irradiating light, for example, linearly polarized light, to an alignment layer, for example, an alignment layer including the composition for the photoalignment layer.

The alignment layer may be formed by, for example, coating the composition for the photoalignment layer described above or a coating solution prepared using the same, and drying the same. The method of carrying out the coating and the thickness of the coating layer formed thereby are not particularly limited. For example, the coating may be performed by a bar coating, a comma coating, a spin coating, or the like, and may be performed such that a dry thickness of the coating layer is about 800 kPa to 5,000 kPa.

When the coating liquid contains a solvent, the alignment layer may be formed through the coating and then drying. In this case, the conditions for drying are not particularly limited, and for example, the drying may be performed under conditions such that the solvent present in the coating liquid can be removed to an appropriate level. For example, drying is about 25? To 150? It may be performed at a temperature within the range of about 30 seconds or more, but is not limited thereto.

After formation of the alignment layer, light, for example, linearly polarized light, may be irradiated to align the photo-alignment material and impart orientation force. In this case, for example, by adjusting the intensity and irradiation angle of the irradiated light, it is possible to adjust the alignment direction of the liquid crystal subsequently formed, and to form the liquid crystal layer including the spray-oriented region and the vertically aligned region. This is possible. For example, in the case of adjusting the irradiation amount high at the time of irradiation of light, the irradiation of light, for example, the irradiation direction is about 1 to 40 degrees, about 2 to 40 degrees, About 3 to 40 degrees, about 4 to 40 degrees, about 5 to 40 degrees, about 7 to 40 degrees, about 9 to 40 degrees, about 10 to 40 degrees, about 15 to 40 degrees, or about It can adjust so that it may be about 15 to 35 degrees. Through such adjustment, it is possible to form the liquid crystal layer as described above. The irradiation amount of the light irradiated above is set high, for example, the irradiation amount is 45 mJ / cm ² or more or 50 mJ / cm ² It means to do more than enough. In addition, the upper limit of the said irradiation amount is not specifically limited, For example, about 70 mJ / cm <^2> Or less than or about 60 mJ / cm ² . Also, the angle formed by the normal line and the irradiation direction may mean a minimum angle formed by the normal line and the irradiation direction with respect to the alignment layer surface. The irradiation amount may be, for example, an irradiation amount when the wavelength of the irradiated light is in the UVB range, for example, about 280 nm to 320 nm.

On the other hand, when the intensity of the irradiated light is weakened, the above-mentioned liquid crystal layer can be formed by irradiating such that the irradiation direction is substantially parallel to the normal of the surface of the alignment layer. In this case, that the intensity of the irradiated light becomes weak is that the amount of irradiated light is 40 mJ / cm ^2. Or less than 35 mJ / cm ² This may mean the following. In addition, the upper limit of the said irradiation amount is not specifically limited, For example, about 20 mJ / cm <^2> Or at least about 25 mJ / cm ² . The irradiation amount may be, for example, an irradiation amount when the wavelength of the irradiated light is in the UVB range, for example, about 280 nm to 320 nm.

After the light is irradiated to the alignment layer as described above, the liquid crystal coating liquid may be coated on the upper portion thereof to form a liquid crystal layer. The liquid crystal coating liquid can be prepared by conventional methods known in the art. For example, the above-mentioned polymerizable liquid crystal compound and other required additives may be mixed in an appropriate solvent to prepare a liquid crystal coating liquid. The liquid crystal coating liquid may be coated on the alignment layer through a suitable technique, and if necessary, after passing through a drying process, the liquid crystal compound may be aligned to form a liquid crystal layer. If necessary, a step of polymerizing the liquid crystal compound through irradiation of light or the like may also be performed. The manner in which the alignment and / or polymerization of the liquid crystal compound is performed is not particularly limited, and a method known in the art may be applied.

The liquid crystal film manufactured as described above may be applied to various applications including, for example, a retardation film or a viewing angle compensation film for a display device, a protective film of a polarizer, and the like.

The present application also relates to a liquid crystal display. An exemplary liquid crystal display can include the liquid crystal film. The liquid crystal film may be included in the liquid crystal display, for example, as a retardation film or a viewing angle compensation film.

The liquid crystal film includes a spray oriented region and a vertically oriented region as described above, and can be produced by freely adjusting the alignment direction of the liquid crystal in each oriented region, and thus can be suitably used in a wide variety of applications.

An example in which such a liquid crystal film may be effectively applied may be a liquid crystal display of an in-plane switching method. Typically, the liquid crystal in the liquid crystal cell of the transverse electric field type liquid crystal display is not in a perfect horizontal alignment, but exists in a slightly tilted horizontal alignment state. Therefore, when optical compensation is performed using a conventional vertically aligned liquid crystal film, left and right asymmetry may occur. However, in the case of the liquid crystal film, it can be applied by adjusting the alignment direction of the liquid crystal vertically aligned in accordance with the inclination direction of the liquid crystal in the liquid crystal cell of the transverse electric field type liquid crystal display, in this case can solve the above-mentioned left and right asymmetry problem have.

The method of including the liquid crystal film in the liquid crystal display is not particularly limited, and the liquid crystal film may be applied in accordance with a conventional method of using a retardation film or a viewing angle compensation film.

The present application provides a composition for a photo-alignment layer that implements an alignment layer that can effectively form an alignment layer having a vertical alignment force. When the composition for photo-alignment layer is used, the orientation direction of a liquid crystal can be adjusted easily, and the liquid crystal film which shows suitable physical properties according to a use can be manufactured freely.

1 is a conceptual diagram of an exemplary liquid crystal film substrate.
2 is a conceptual diagram for explaining the x-axis, y-axis and z-axis of the liquid crystal layer.
3 is a view conceptually showing the alignment state of the liquid crystal in the liquid crystal layer.

Hereinafter, the present application will be described in more detail with reference to examples according to the present application and comparative examples according to the present application, but the scope of the present application is not limited thereto.

Example  One.

2 parts by weight of poly (5-norbornene-2-methyl- (4-methoxy cinnamate)) as a photo-alignment substance, 1 part by weight of dipentaerythritol hexaacrylate as a polar binder and a photoinitiator (Irgacure 907, Ciba- 0.5 parts by weight of Geigy, Switzerland) was dissolved in about 96.8 parts by weight of a solvent (cyclopentanone) to prepare a coating solution for an alignment layer. Thereafter, the prepared coating solution was applied onto a TAC (Triacetyl cellulose) film so as to have a thickness of about 0.1 μm after drying, and 70? It dried in the oven of the grade and formed the oriented film. Subsequently, the polarization direction is adjusted in a direction perpendicular to the advancing direction of the film while moving the TAC film on which the alignment layer is formed in a predetermined direction, using a high pressure mercury lamp (80 W / cm) and a wire grid polarizer. (Irradiation: about 30 mJ / cm ² , irradiation wavelength: UVB (about 280 nm to about 320 nm), where the irradiation direction was parallel to the normal of the surface of the alignment film, and the film was about 10 m / The light was irradiated at a speed of about min, followed by dissolving 95 parts by weight of a spray-alignable nematic rod-like polymerizable liquid crystal compound and 5 parts by weight of a photoinitiator (Irgacure 907, manufactured by Ciba-Geigy, Switzerland) in toluene. The liquid crystal coating liquid (about 25 wt% of solid content in the coating liquid) was applied onto the alignment film so that the thickness after drying was about 1 μm, and dried by hot air for about 2 minutes in an oven of about 60 °. For curing upon irradiation with ultraviolet rays by a high pressure mercury lamp (80 W / cm) to form a vertical alignment liquid crystal layer.

Test Example  One.

The liquid crystal film produced in Example 1 was compared with a conventionally known vertically oriented liquid crystal film (control group, Δn = 0.1, liquid crystal layer thickness: 1 μm). Specifically, the retardation (Rin) according to the inclination angle of each film was compared, and the retardation was evaluated in a known manner using the Axoscan equipment using the fast axis of the liquid crystal layer as the rotation axis. The phase difference according to the inclination angle is shown in Table 1 below. The results shown in Table 1 below are in-plane retardation according to the inclination angle of each film, and the thickness direction retardation of each film was the same at 100 nm.

Example 1 Control group Tilt angle in degrees Phase difference in nm Phase difference in nm -50 31.5 27.7 -40 22.0 18.7 -30 14.0 10.9 -20 7.7 4.9 -10 3.5 1.2 0 1.7 0.0 10 2.3 1.2 20 5.2 4.9 30 10.5 10.9 40 17.6 18.7 50 26.0 27.7

From the results of the above table, the conventional vertically oriented liquid crystal film (optical axis: 90 degrees) (control) shows the same phase difference at an inclination angle of +50 degrees and -50 degrees, whereas the liquid crystal film of Example 1 (optical axis: about 88 degrees) has an inclination angle + It can be seen that the asymmetrical phase difference at 50 degrees and -50 degrees. In addition, it was confirmed that the optical axis of the liquid crystal film of Example 1 was inclined by about 2 degrees in the direction in which the phase difference value was measured small. This confirmed that the liquid crystal layer having the spray oriented region and the vertically oriented region was effectively formed.

10: substrate film
20: orientation layer
100: liquid crystal layer
300: surface in contact with the alignment layer of the liquid crystal layer

Claims (21)

Composition for forming a vertically oriented photoalignment layer comprising a photo-alignment material and a vertically oriented polar functional group. The photo-alignment material according to claim 1, wherein the photo-alignment material is an azo compound, stilbene compound, cyclobutane tetracarboxylic dianhydride, aromatic polysilane, aromatic polyester, polystyrene, cinnamate compound, coumarin compound, cinnamic amide compound, tetrahydrophthalimide Vertically oriented photoalignment which is a compound, a maleimide compound, a benzophenone compound, a diphenylacetylene compound, a chalcone compound, an anthracenyl compound, a benzoate compound, a benzoamide compound, a methacrylamidoaryl (meth) acrylate compound or a spiropyrane compound Layer forming composition. The composition for forming a vertically oriented photoalignment layer according to claim 1, wherein the vertically oriented polar functional group is acryloyl group or methacryloyl group. The composition of claim 1, wherein the vertically oriented polar functional group is bonded to the photo-alignment material. The composition of claim 1, further comprising a polar binder comprising a photoalignable material and a vertically oriented polar functional group. The composition for forming an optical alignment layer according to claim 5, wherein the polar binder is an acrylate compound. The composition of claim 5, wherein the composition comprises 30 to 100 parts by weight of a polar binder based on 100 parts by weight of the photoalignable material. A base film; And a vertical alignment layer formed on the substrate and comprising the composition of claim 1. A vertical alignment layer comprising the composition of claim 1; And a liquid crystal layer formed on the vertical alignment layer, the liquid crystal layer comprising a vertically aligned liquid crystal. 10. The liquid crystal film according to claim 9, wherein the liquid crystal layer comprises a region in which vertically oriented liquid crystals exist and a region in which spray oriented liquid crystals exist. The liquid crystal film according to claim 10, wherein the plane retardation of the liquid crystal layer is 0.5 nm to 10 nm. The liquid crystal film according to claim 10, wherein the thickness direction retardation of the liquid crystal layer is 50 nm or more. A method for producing a liquid crystal film comprising irradiating linearly polarized light to a vertical alignment layer comprising the composition of claim 1. The manufacturing method of Claim 13 which adjusts the irradiation direction of the linearly polarized light so that it may become 1 degree-40 degree with the normal of the surface of an orientation layer. The manufacturing method of Claim 14 which adjusts the irradiation amount of the linearly polarized light to 45 mJ / cm <^2> or more. The production method according to claim 15, wherein the wavelength of the irradiated light is adjusted to 280 nm to 320 nm. The manufacturing method of Claim 13 which adjusts the irradiation direction of linearly polarized light so that it may be parallel with the normal line of the surface of an orientation layer. The manufacturing method of Claim 17 which adjusts the irradiation amount of the linearly polarized light to 40 mJ / cm <^2> or less. The method of claim 18, wherein the wavelength of the irradiated light is adjusted to between 280 nm and 320 nm. A liquid crystal display comprising the liquid crystal film of claim 9. The liquid crystal display according to claim 20, comprising a transverse electric field type liquid crystal cell.

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