2190 results about "Optical anisotropy" patented technology

A retardation film that has an optical retardation layer whose alignment direction is controlled precisely and that is produced at a low cost, and also a method for producing the same, are provided. The explanation below relates to FIG. 1. First, a base-attached anisotropic layer 12 is prepared by laminating an optically anisotropic layer 11 on a transparent base 10. Next, on the optically anisotropic layer 11, a solution containing a polymer reacting with polarized ultraviolet light and a liquid crystalline compound is coated and dried. Then, it is irradiated with polarized ultraviolet light so as to align the liquid crystalline compound, and irradiated further with unpolarized ultraviolet light as required to crosslink the liquid crystalline compound, thereby forming a retardation film 1 having an optical retardation layer 13 that is directly formed on the optically anisotropic layer 11.

A circularly polarizing plate comprises a linearly polarizing membrane and a quarter wave plate. The quarter wave plate comprises an optically anisotropic layer A and an optically anisotropic layer B. The quarter wave plate has such an optical characteristic that a retardation value essentially is a quarter of a wavelength when the retardation value is measured at the wavelength of 450 nm, 550 nm and 650 nm. One of the optically anisotropic layers A and B is a layer made from liquid crystal molecules, and the other is a polymer film or a layer made from liquid crystal molecules.

There is disclosed a lightweight and small liquid crystal display which achieves low power consumption and in which the optical anisotropy of the liquid crystal material is compensated for in order to enhance the viewing angle characteristics and the response speed of the liquid crystal material. Display electrodes and a common electrode are formed on one of the substrates. The orientation of the liquid crystal material is of the HAN (hybrid alignment nematic) type. This compensates for the optical anisotropy of the liquid crystal material and improves the response speed.

A display panel includes (i) a first substrate and a second substrate, which face each other, (ii) a medium layer being sandwiched between the first and second substrate, and (iii) first electrodes and second electrodes being provided on that side of the first substrate which faces the second substrate, the display panel performing display operation by generating an electric field between the first and second electrodes. The display panel is configured such that the medium layer comprises a medium that is optically isotropic when no electric field is applied thereon, and whose optical anisotropy magnitude is changeable by and according to the electric field applied thereon; and the first and second electrodes are transparent electrodes, and a distance between the first and the second electrodes is shorter than a distance between the first substrate and second substrate. This configuration attains gives the display panel high response speed and high transmissivity.

A novel liquid crystal display is disclosed. The display comprises a pair of substrates disposed facing each other and at least one of which has an electrode, a liquid-crystal layer being sandwiched in between the pair of substrates and comprising liquid-crystal molecules aligned along with a first alignment axis and a second alignment axis respectively formed on facing surfaces of the first and second substrates, a pair of polarizing plates disposed sandwiching the liquid-crystal layer, and at least an optically anisotropic layer disposed between the liquid-crystal layer and either of the polarizing plates, and comprising at least one liquid crystal compound which is aligned along with a third alignment axis and is fixed in the alignment state. And their disposition satisfies at least one of Condition (1): the alignment axes of the substrates are not parallel to transmission axes of the polarizing plates; and Condition (2): the alignment axis of the substrate is not parallel to the alignment axis of the optically anisotropic layer.

A display element of the present invention includes: a pair of substrates at least one of which is transparent; a medium layer, made of a medium sandwiched between the substrates 1 and 2, whose magnitude of an optical anisotropy is changed by applying an electric field; and at least a pair of electrodes applying to the medium layer an electric field which is substantially parallel to the substrates. The electrodes are provided above the substrate via insulating layers each of which is formed in a convex shape. Therefore, a maximal electric field region generated by the electrodes is separated from interfaces of the substrates.

An optical compensatory sheet comprises an optically anisotropic layer formed of discotic liquid crystal molecules provided on a transparent substrate. The liquid crystal molecules are horizontally aligned in the optically anisotropic layer. An average inclined angle between discotic planes of the discotic liquid crystal molecules and a surface of the transparent substrate is less than 5°. The discotic liquid crystal molecules are fixed in the optically anisotropic layer while keeping the horizontal alignment.

An optically anisotropic cellulose ester film is disclosed. The film contains a discotic compound in an amount of 0.01 to 20 weight parts based on 100 weight parts of cellulose ester. The film has a Rth<550 >retardation value in the range of 60 to 1,000 nm. The cellulose ester film can be used in an optical compensatory sheet, an ellipsoidal polarizing plate and a liquid crystal display.

A polymerizable compound has a practical low melting point, excellent solubility in a general-purpose solvent, and can produce an optical film at low cost, exhibits low reflected luminance, and achieves uniform conversion of polarized light over a wide wavelength band, an optically anisotropic article. A carbonyl compound is useful as a raw material for producing the polymerizable compound. (In the formula (I), Y¹ to Y⁸ represent —C(═O)—O—, G¹ and G² represent a C_1-20 divalent linear aliphatic group, Z¹ and Z² represent a C_2-10 alkenyl group that is unsubstituted, or substituted with a halogen atom, A^x represents a C_2-30 organic group with at least one aromatic ring, A^y represents a hydrogen atom or C_1-20 alkyl group, A¹ represents a trivalent aromatic group, A² and A³ represent a C_3-30 divalent alicyclic hydrocarbon group, A⁴ and A⁵ represent a C_6-30 divalent aromatic group or the like, and Q¹ represents a hydrogen atom.)

A liquid crystal display device of the present invention is a liquid crystal display device having a first substrate, a second substrate, a liquid crystal layer disposed between the first and second substrates, and a plurality of pixels each having a display region, in that: the liquid crystal layer is optically isotropic when an selective electric field is not applied and optically aisotropic when an electric field is applied and includes a material whose refractive index changes depending on the strength of the electric field; and the plurality of pixels include first and second pixels different in the electric field strength.

A process of readily producing a patterned birefringent product excellent in resolution and heat-resistance is provided. Said process comprises at least the following steps [1] to [3] in order:

• • [1] preparing a birefringence pattern builder which comprises an optically anisotropic layer comprising a polymer, and said optically anisotropic layer has a retardation disappearance temperature in the range higher than 20° C.,
  • at said retardation disappearance temperature in-plane retardation becomes 30% or lower of the retardation at 20° C. of the same optically anisotropic layer, and
  • said retardation disappearance temperature rises by light exposure;
  • [2] subjecting the birefringence pattern builder to patterned light exposure;
  • [3] heating the laminated structure obtained after the step [2] at 50° C. or higher and 400° C. or lower.

A method for producing an optical film including: laminating a hard coat layer on one side of an optical substrate in roll form, the hard coat layer having a transparent support and an optical anisotropic layer. The transparent support is laminated on the optical anisotropic layer, the one side is a transparent support-side of the optical substrate, the hard coat layer is obtained by coating, drying and curing a composition for forming a hard coat layer containing a curable monomer, a photo-polymerization initiator, and a solvent. The solvent is a mixture of at least one solvent selected from (S-1) and (S-2) and at least one solvent selected from (S-3), or a mixture of at least one solvent selected from (S-1) and at least one solvent selected from (S-2): (S-1) solvents dissolving the transparent support; (S-2) solvents swelling the transparent support; and (S-3) solvents neither dissolving nor swelling the transparent support.

The present invention relates to a polymerizable compound represented by a formula (I). The present invention provides a polymerizable compound, a polymerizable composition, a polymer, and an optically anisotropic article that are capable of obtaining an optical film having a low melting point, having excellent solubility, capable of being manufactured at low cost, and capable of uniform polarized light conversion across a broad wavelength region. [In formula: Y¹ to Y⁶ are independently a chemical single bond, —O—, —O—C(═O)—, —C(═O)—O— etc.; G¹ and G² are independently a divalent C1-C20 aliphatic group etc.; Z¹ and Z² are independently C2-C10 alkenyl group that is substituted with a halogen atom etc.; A^x is a C2-C30 organic group that includes at least one aromatic ring selected from a group consisting of an aromatic hydrocarbon ring and an aromatic hetero ring; A^y is a hydrogen atom, a C1-C20 alkyl group, a C2-C20 alkenyl group, a C3-C12 cycloalkyl group etc.; A¹ is a trivalent aromatic group etc.; A² and A³ are independently a divalent C6-C30 aromatic group etc.; and Q¹ is a hydrogen atom, or a C1-C6 alkyl group etc.]

Provided is a liquid-crystalline, polymerizable vinyl ketone compound of formula (1):

Preferably, R¹ is hydrogen, halogen, —CN, —CF₃, —CF₂H, —CFH₂, —OCF₃, —OCF₂H, or alkyl, alkoxy, alkoxyalkyl or alkenyl having from 1 to 10 carbon atoms; R², R³ and R⁵ are hydrogen; A¹ to A⁴ are independently 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene where any hydrogen may be substituted with halogen; Z¹ to Z³ are independently a single bond, —(CH₂)₂—, —CH═CH—, —CF═CF—, —OCF₂— or —CF₂O—; Z⁴ is a single bond, —(CH₂)₃— or —(CH₂)₄—; m, n and q are independently 0, 1 or 2. The uppermost temperature of the liquid crystalline phase of the compound is high, and the compound has good compatibility with other compounds and has the necessary characteristics such as optical anisotropy. Also provided are a polymer having many good characteristics of transparency, mechanical strength, coatability, solubility, crystallinity, shrinkage, water permeability, water absorption, melting point, glass transition point, clearing point and chemical resistance; an optically-anisotropic material of the polymer; a liquid-crystal display device that comprises the polymer; and a method for producing the liquid-crystalline compound.

A liquid crystal composition is provided that satisfies at least one characteristic among the characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a large optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or is properly balanced regarding at least two characteristics. An AM device is provided that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The liquid crystal composition contains a specific tricyclic compound having a large optical anisotropy as the first component and a specific tetracyclic compound having a large dielectric anisotropy as the second component, and may contain a specific bicyclic compound having a particularly small viscosity as the third component. The liquid crystal composition has a nematic phase. The liquid crystal display device contains the liquid crystal composition.

The present invention provides a liquid crystal composition with positive dielectric anisotropy, comprising: one or more compounds selected from compounds expressed in general formula I, general formula II, and general formula III, and a combination thereof as a first component; one or more compounds selected from compounds expressed in general formula IV, general formula V, and general formula VI, and a combination thereof as a second component, the dielectric anisotropy of the first component being positive, and the dielectric anisotropy of the second component being negative. The liquid crystal composition not only maintains advantages such as fast response, a low drive voltage, a high clearing point, low rotary viscosity, appropriate optical anisotropy and appropriate dielectric anisotropy of IPS liquid crystal, but also significantly improves the transmittance of the liquid crystal display. Compared with existing IPS liquid crystal with positive dielectric anisotropy, the liquid crystal composition can improve the transmittance by 5 to 20%. The present invention further provides a liquid crystal display including the liquid crystal composition of the present invention and having an IPS display mode.

Each of a pair of substrates respectively comprises an electrode and a rubbed alignment film on one surface, while the other surface is provided with a polarizer. The substrates are placed so that the surfaces provided with the alignment films are opposed to each other, and the area between the substrates is filled with a medium to form a material layer. Then, a medium made of a negative-type liquid crystalline compound sing a photopolymerizable monomer and a polymerization initiator is injected into the material layer held between the substrates. Further, ultra violet irradiation is performed with the medium exhibiting a liquid crystal phase, so that the photopolymerized monomer is polymerized, thus forming a polymer chain. In this manner, obtained is a display element, that causes change in degree of optical anisotropy in response to application of electric (external) field, which display element can be driven by a lower intensity electric (external) field.

Such a liquid crystal compound is provided that has stability to heat, light and so forth, has a nematic phase in a wide temperature range, has a small viscosity, a suitable optical anisotropy, and suitable elastic constants K₃₃ and K₁₁ (K₃₃: bend elastic constant, K₁₁: splay elastic constant), and has suitable negative dielectric anisotropy and excellent compatibility with other liquid crystal compounds. A liquid crystal composition containing the liquid crystal compound, and a liquid crystal display device containing the liquid crystal composition are also provided.

The liquid crystal compound is represented by one of formulas (a) to (d), the liquid crystal composition contains the liquid crystal compound, and the liquid crystal display device contains the liquid crystal composition:

wherein Ra and Rb are independently linear alkyl or linear alkoxy, rings A¹, A², B and C are independently trans-1,4-cyclohexylene or 1,4-phenylene, Z¹¹, Z¹², Z² and Z³ are independently a single bond or alkylene, and one of X₁ and X₂ is fluorine, and the other thereof is chlorine.

The subject is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or that is suitably balanced regarding at least two characteristics. The subject is to provide an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The invention provides a liquid crystal composition having a negative dielectric anisotropy that contains a specific compound having negatively large dielectric anisotropy as the first component, and has a specific two ring compound having a low viscosity as the second component, and provides a liquid crystal display device containing the composition.

Provided is a retardation film comprising a polymer film, and, disposed thereon, an optically-anisotropic layer, of which thickness is equal to or less than 5 μm, of which in-plane retardation at a wavelength of 550 nm, Re(550), is from 0 to 10 nm, and of which thickness-direction retardation at the same wavelength, Rth(550), is from 250 to 450 nm; and satisfying the following formula: 1.00≦Rth(450)/Rth(550)≦1.07 or 1.04≦Rth(450)/Rth(550)≦1.09.

A liquid crystal composition is provided that satisfies at least one characteristic among the characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a large optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or is properly balanced regarding at least two characteristics. An AM device is provided that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The liquid crystal composition contains a specific compound having especially negatively large dielectric anisotropy as the first component,a specific bicyclic compound having a small viscosity as the second component, a specific compound having a high maximum temperature as the third component, a specific compound having a negatively large dielectric anisotropy, a low minimum temperature as the fourth component. The liquid crystal composition has a negative dielectric anisotropy. The liquid crystal display device contains the liquid crystal composition.

The subject is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, a high stability to heat and a large elastic constant, or that is suitably balanced regarding at least two of the characteristics. The subject is to provide an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The invention provides a liquid crystal composition that has a nematic phase and includes a four-ring compound containing a dioxane ring and having a high maximum temperature and a large dielectric anisotropy as a first component, a specific two-ring compound having a small viscosity as a second component, a specific three-ring compound having a large dielectric anisotropy as a third component and a specific four-ring compound having a high maximum temperature and a large dielectric anisotropy, and also provides a liquid crystal display device containing this composition.

The invention discloses a negative dielectric anisotropic liquid crystal composition, which contains the following components by weight: 1-60% of a component A represented by a formula I, 1-70% of component B represented by a formula II or/and a formula III, and 0-40% of component C represented by a formula IV. The liquid crystal composition has characteristics of wide optical anisotropic range, large absolute value negative dielectric anisotropy, high resistivity and high clearing point, is very suitable for manufacturing an optical element and an LCD of a VA mode, and is especially suitable for a low-voltage-driven vehicle-mounted VA-LCD.