New dichroic dyes having a composition with slave materials. The dyes may be used for a dichroic polymer network, a dichroic liquid crystalline polymer film (LCP film) or a dichroic liquid crystalline polymer gel, which for instance find application as electro-optical or optical devices.

The present application relates to a liquid-crystalline material which comprises at least one dye compound and at least one compound of a formula (IA) or (IB). The liquid-crystalline material is suitable for use in optical switching devices, in particular in devices for the homogeneous regulation of the passage of light through an area.

The present invention provides, as a composition containing a smectic liquid crystal compound which can be used for production of a homogeneous optical film at a temperature around room temperature, a composition containing a smectic liquid crystal compound having a 1,4-cyclohexyl group, which smectic liquid crystal compound having the 1,4-cyclohexyl group contains (i) 100 parts by mass of a smectic liquid crystal compound having a trans-1,4-cyclohexyl group and (ii) 0.1 parts by mass to 10 parts by mass of a smectic liquid crystal compound having a cis-1,4-cyclohexyl group.

A liquid crystal element includes two substrates with a transparent conductive film, the substrates being arranged such that transparent conductive films face each other, and a liquid crystal-polymer composite film which is sandwiched between the two substrates with a transparent conductive film, in which the liquid crystal-polymer composite film contains an acetylene alcohol.

Liquid-crystal composition comprising (A) dye compounds and (B) a liquid crystal material, wherein the dye compounds (A) include an anthraquinone compound represented by general formula (1) and an anthraquinone compound represented by general formula (2) in a specific proportion and further include a dye compound which is neither the anthraquinone compound represented by general formula (1) nor the anthraquinone compound represented by general formula (2), The liquid-crystal composition also may include the (A) and (B) components and further containing (C) a photocurable compound and (D) a photopolymerization initiator A cured object obtained from the liquid-crystal composition, and a light-modulating element in which the liquid-crystal composition or the cured object is sandwiched therein are also set forth. ##STR00001##

The present invention is an anthraquinone compound represented by formula (1) (in the formula, R.sub.1 represents a hydrogen atom, a straight chain or branched chain alkyl group having a carbon count of 1-12, or a straight chain or branched chain alkoxy group having a carbon count of 1-12. R.sub.2 represents a hydrogen atom, a straight chain or branched chain alkyl group having a carbon count of 1-8, or a straight chain or branched chain alkoxy group having a carbon count of 1-8). R.sub.2 may be a straight chain or branched chain alkyl group having a carbon count of 1-8. R.sub.1 may be a straight chain or branched chain alkoxy group having a carbon count of 1-8, or may be a straight chain or branched chain alkyl group having a carbon count of 1-4. The present invention also relates to a dimming liquid crystal composition containing this anthraquinone compound and a liquid crystal material. The present invention also relates to a dimming element obtained by sandwiching the dimming liquid crystal composition or a photocured product thereof between a pair of substrates disposed facing each other, at least one among which is a transparent substrate having a transparent electrode.

##STR00001##

An optical system that includes a cholesteric glassy liquid crystal film doped with a dye and configured to preferentially absorb light of a first handedness, such as left-hand circularly polarized (LCP) light, but pass light of the opposite handedness, such a right-hand circularly polarized (RCP) light. Adding an anti-reflection coating can further increase the transmission-to-reflection ratio.

A liquid crystal element including: two substrates having a transparent conductive layer formed thereon, the substrates being arranged so that the transparent conductive layers face each other, and a liquid crystal-polymer composite film sandwiched between the two substrates having a transparent conductive layer, wherein the liquid crystal-polymer composite film includes a polymer matrix and a liquid crystal composition surrounded by the polymer matrix, the liquid crystal composition contains a liquid crystal component and a dichroic dye, the liquid crystal component has positive dielectric constant anisotropy, and has an NI point of 110 C. or higher and 150 C. or lower, the liquid crystal component has a refractive index anisotropy of 0.01 or more and 0.1 or less, and the liquid crystal-polymer composite film can be switched between a transparent state and a colored state by applying a voltage.

The present invention provides a liquid crystal dimming device. The liquid crystal dimming device of the present application sequentially comprises, from bottom to top, a lower substrate, a lower conductive layer, a lower alignment layer, a guest-host liquid crystal composition layer, an upper alignment layer, an upper conductive layer, and an upper substrate; alignment directions of the upper alignment layer and the lower alignment layer are parallel alignment; the guest-host liquid crystal composition layer comprises at least one dichroic dye, at least one chiral agent and at least one liquid crystal composition; wherein, the liquid crystal composition comprises at least one compound of general formula N. The liquid crystal dimming device of the present invention has an appropriate transmittance (T.sub.r0, T.sub.r255), an appropriate contrast rate, a higher VHR (initial), a higher VHR (Ra) and a wider operation temperature range. The dimming device of the present invention has a better display effect at the moment of power-off after applying power on it for 2 h, and can effectively avoid the problems of display mura and image sticking.

A liquid crystal element includes two substrates with a transparent conductive film, the substrates being arranged such that transparent conductive films face each other, and a liquid crystal-polymer composite film which is sandwiched between the two substrates with a transparent conductive film, in which the liquid crystal-polymer composite film contains an acetylene alcohol.