摘要:
Ferroelectric liquid-crystal display of high contrast and brightness. The use of alignment layers containing compounds having an amphiphilicity-providing effect increases the contrast and brightness of the image in FLC displays.
摘要:
A liquid crystal mixture composed of at least two components containing as one component a macrocyclic compound of the general formula (1) ##STR1## in which a, b, c, d, e, f, independently of one another, are an integer from zero to 4, a+b+c+d+e+f being greater than 7, and--A--, --B--, --C--, --D--, --E--, --F--, identical or different, are, for example, --CH.sub.2 --, --CH.dbd.CH--, --CO-- or --COO--, leads in FLC displays to the formation of a uniform alignment and avoids twist states, which is reflected in a significantly improved contrast.
摘要翻译:由至少两种组分组成的液晶混合物,其中a,b,c,d,e,f彼此独立地为一个组成的通式(1)的大环化合物,其中a,b,c,d,e,f为 一个从零到四的整数,a + b + c + d + e + f大于7,和-A-,-B-,-C-,-D-,-E-,-F-,相同或 不同的是例如-CH 2 - , - CH = CH - , - CO-或-COO-,在FLC显示器中导致形成均匀的排列并避免扭曲状态,其反映在明显改善的对比度中。
摘要:
An alignment layer for liquid-crystal displays which contains at least one compound containing, as structural element, a mediocyclic or macrocyclic carbon ring, results, in displays, in significantly increased contrast, inter alia.The mediocyclic or macrocyclic structural elements may also contain heteroatoms, such as, for example, O, N and S atoms.
摘要:
An alignment film for liquid crystals comprising a quasi-monomolecular layer of compounds of the formula II C.sub.y --S.sub.p --A.sub.n (II) in which C .sub.y is a mediocyclic or macrocyclic carbon ring having 8 or more ring members, it also being possible for this ring to contain fused benzene rings and --O--, --N--, --S--, --Si-- and --B-- as heteroatoms; S.sub.p is an alkyl group having from 1 to 20 carbon atoms, in which one or more non-adjacent --CH.sub.2 --groups may be replaced by --O--, --S--, --CO--, --O--CO--, --NH--CO--, --O--COO--, --NH--CO--NH--, --NH--CO--O--, --SO.sub.2 --, --Si(CH.sub.3).sub.2 --, --CH.dbd.CH-- or --C.tbd.C--; A.sub.n is SiX.sup.1 X.sup.2 X.sup.3, where X.sup.1 is a single bond, and X.sup.2 and X.sup.3, independently of one another, are a single bond or an alkyl or alkoxy group, where the compound of the formula (II) is bonded to an oxidic layer via the single bond(s) of the group A.sub.n. The alignment films according to the invention are highly suitable for the alignment of liquid crystals, in particular ferroelectric liquid crystals. The low thickness of the alignment film prevents dielectric losses in the display. The occurrence of ghost images is substantially suppressed.
摘要:
Use of a polymer containing maleimide units of the formula I ##STR1## in which R.sup.1 is hydrogen, an acyclic or cyclic, aliphatic, aromatic or araliphatic radical which is chiral or achiral, can be monosubstituted or polysubstituted by functional groups and in which one or more CH.sub.2 groups can be replaced by functional groups, as alignment layer in liquid-crystal displays.Alignment layers containing a polymer conforming to the formula I effect, in particular, a suppression of twist states and ghost images and thus an improvement in the optical contrast.
摘要:
Selectively dehalogenated thiophene derivatives are obtained from compounds of the formula II ##STR1## by an electrochemical reaction in a divided electrolysis cell in the presence of a suitable solvent, an onium compound or a compound which is converted into an onium compound in the electrolyte, and a conducting salt. Thiophene derivatives are important intermediates in the production of pharmaceuticals and plant protection agents.
摘要:
An ultrasound apparatus has a transducer array which includes a number of individual transducer, each transducer having a channel exclusively associated therewith. In an input stage for the ultrasound apparatus, an analog stage is provided in each channel to which the echo signals for a transducer associated with that channel are supplied. This analog stage concludes with an analog-to-digital converter in each channel. The output of the analog-to-digital converter is connected to a further processing circuit in each channel for the acquisition of Doppler signals of moving target echoes. A combined ultrasound imaging device and Doppler device is thus achieved, which allows the acquisition of Doppler signals with the digital input technology of the ultrasound imaging processing circuit. This permits expansion of digital operating RF input components of imaging devices to include Doppler signal processing.
摘要:
The invention relates to a process for the production of chloroalkylsulfonyl isocyanates of the formula ##STR1## by a catalytically induced reaction of chlorosulfonyl isocyanate with one or more C.sub.2 -C.sub.4 -olefins. The reaction is carried out in a continuous manner in a tubular reactor.
摘要:
The invention relates to intrinsically electrically conductive polymers, preferably oligomers, which, in the oxidized form, are completely soluble in dipolar aprotic solvents at room temperature and which contain structural units which are derived from at least one monomer of the formula (I) ##STR1## in which R.sup.1 is a C.sub.1 -C.sub.2 -alkoxy group or --O(CH.sub.2 CH.sub.2 O).sub.n CH.sub.3 with n=1 to 4 and R.sup.2 is a hydrogen atom, a C.sub.1 -C.sub.12 -alkyl group, a C.sub.1 -C.sub.12 -alkoxy group or --O(CH.sub.2 CH.sub.2 O).sub.n CH.sub.3 with n=1 to 4, or R.sup.1 and R.sup.2 together are --O(CH.sub.2).sub.m --CH.sub.2 or --O(CH.sub.2).sub.m --O-- with m=1 to 12. The invention also relates to a process for the preparation of these polymers by electrochemical polymerization of at least one monomer of this formula (I) in the presence of a conductive salt, the anode having a specific surface area of at least 0.01 m.sup.2 /g and preferably a gauze, sponge, fabric or felt structure, the electrolyte solvent being dipolar and aprotic and the electrolyte system being moved only slightly or not at all relative to the anode. The polymers according to the invention can readily be used especially for coating purposes.
摘要:
Thiophene ethers having relatively large side chains can be easily obtained by reacting 2-, 3-, 2,3-, 2,4- or 3,4-C.sub.1 -C.sub.3 -alkoxythiophenes in the presence of an acid catalyst with a compound containing an OH group. The novel thiophene ethers are suitable as monomers for electrically conducting polymers.