摘要:
Mixtures of organic ammonium salts composed of 20 to 80% of a quaternary ammonium salt of the formula ##STR1## and 80 to 20% by weight of an amine salt of the formula ##STR2## where in both formulae R.sup.1 denotes C.sub.12 -C.sub.26 -alkyl, C.sub.12 -C.sub.26 -alkenyl, C.sub.12 -C.sub.26 -fluoroalkyl, C.sub.12 -C.sub.26 -fluoroalkenyl or a group of the formula ##STR3## R.sup.2 and R.sup.3 denote C.sub.1 -C.sub.3 -alkyl, preferably methyl, R.sup.4 denotes C.sub.1 -C.sub.4 -alkyl and, for the case where R.sup.1 =alkyl or alkenyl, also a group of the formula --(C.sub.2 H.sub.4 O).sub.z H,R.sub.f denotes C.sub.8 -C.sub.20 -fluoroalkyl or C.sub.8 -C.sub.20 -fluoroalkenyl,R.sup.5 denotes hydrogen, methyl or ethyl,B denotes oxygen or sulfur,x denotes an integer from 2 to 6,y denotes 0, 1 or 2, andz denotes numbers from 1 to 4, and additionally 30-70 mole %, preferably 40-60 mole %, particularly preferably 50 mol %, of alkali-metal salicylate calculated on the basis of the total amount of .beta.-hydroxynaphthoic acid.
摘要:
Flow accelerating with mixtures of organic ammonium salts composed of 20 to 80% of a quaternary ammonium salt of the formula ##STR1## 80 to 20% by weight of an amine salt of the formula ##STR2## where in both formulae R.sup.1 denotes C.sub.12 -C.sub.26 -alkyl, C.sub.12 -C.sub.26 -alkenyl, C.sub.12 -C.sub.26 -fluoroalkyl, C.sub.12 -C.sub.26 -fluoroalkenyl or a group of the formula ##STR3## R.sub.f --(CH.sub.2).sub.y B(CH.sub.2).sub.x --, R.sup.2 and R.sup.3 denote C.sub.1 -C.sub.3 -alkyl, preferably methyl, R.sup.4 denotes C.sub.1 -C.sub.4 -alkyl and, for the case where R.sup.1 =alkyl or alkenyl, also a group of the formula --(C.sub.2 H.sub.4 O).sub.z H,R.sub.f denotes C.sub.8 -C.sub.20 -fluoroalkyl or C.sub.8 -C.sub.20 -fluoroalkenyl,R.sup.5 denotes hydrogen, methyl or ethyl,B denotes oxygen or sulfur,x denotes an integer from 2 to 6,y denotes 0, 1 or 2,and z denotes numbers from 1 to 4, and additionally 30-70 mole %, preferably 40-60 mole %, particularly preferably 50 mol %, of alkali-metal salicylate calculated on the basis of the total amount of .beta.-hydroxynaphthoic acid.
摘要:
Quaternary ammonium compounds of the formula ##STR1## in which R.sub.1 denotes an alkyl or alkenyl radical with 12 to 22 carbon atoms; R.sub.2 and R.sub.3 are identical or different and denote an alkyl radical with 1 to 4 carbon atoms; x denotes an integral or non-integral number from 1 to 3; and A.sup..crclbar. denotes an alkyl- or alkenyl-sulfonate anion, an alkyl or alkenyl-carbonate anion or a benzoate, naphthoate or phenylsulfonate anion, the tosylate ion being excluded, a process for their preparation and their use as drag reducing agents in liquids with turbulent flow.
摘要:
Optically active 1,3-dioxolane derivatives which carry a mesogenic radical in the 4-position and have the general formula (I) ##STR1## are suitable for use as doping agents in liquid-crystal mixtures--in particular ferroelectric liquid-crystal mixtures. The symbols in the general formula have the following meanings:R.sup.1 is composed analogously to the part of the general formula on the right-hand side of X or is an alkyl or alkylene radical which can be substituted,R.sup.2, R.sub.3 and R.sup.4 are H or alkyl (R.sup.4 is also alkenyl) which can also be substituted [R.sup.2 and R.sup.3, together with the C(2) of the dioxolane ring are also a cycloaliphatic radical or a keto group], J, l and n are zero, 1 or 2 and k and m are zero or 1, subject to the proviso that, if k is zero n is zero and if n is zero m is zero and 1.ltoreq.J+l+n.ltoreq.3,--A.sup.1, --A.sup.2 and --A.sup.3 are an aromatic, heterocyclic or aliphatic ring system, --M.sup.1 and --M.sup.2 are --CO--O, --0--CO, --CH.sub.2 CH.sub.2, --CH.dbd.CH, --CH.sub.2 O, --OCH.sub.2 or --C.tbd.C andX is O, S or O--CO--O.
摘要:
Optically active, mesogenic 1,3-dioxolane-4-carboxylates are suitable as dopes in liquid-crystal mixtures. They result in liquid-crystalline ferroelectric phases having short switching times and in electroclinic phases having large electroclinic coefficients. Their particular advantage is that they induce a helix of very large pitch, meaning that helix compensation by further dopes is unnecessary. In addition, the 1,3-dioxolane-4-carboxylates exhibit high UV stability.
摘要:
The novel liquid-crystalline mixtures (in the case of ferroelectric behavior they additionally contain an optically active compound as dope) are constructed from at least 2 mixture components of the general formula (I): ##STR1## wherein n=6 to 14 and x=2 to 14. In addition, the mixtures may also contain cyclohexanecarboxylates of the general formula (II) ##STR2## where R.sup.1 =(C.sub.10 -C.sub.16) or (C.sub.8 -C.sub.14)alkoxy and R.sup.2 =(C.sub.2 -C.sub.9)alkyl, alkenyloxyphenylpyrimidine derivatives of the general formula (III) ##STR3## where R.sup.3 =(C.sub.7 -C.sub.16)alkyl or (C.sub.6 -C.sub.14)alkoxy and y=4-14, and/or alkoxyphenyl derivatives of alkylpyrimidine, of the general formula (IV) ##STR4## where m and p=6 to 14.
摘要:
Liquid-crystal 5-phenylpyrmidine derivatives having S.sub.c or S.sup.*.sub.c phases and a process for preparing them. The new liquid-crystal 5-phenylpyrimidine derivatives have an S.sub.c or S.sup.*.sub.c phase and are described by the general formula (I) ##STR1## in which the symbols have the following meaning: R.sup.1 and R.sup.2 denote identical or different, straight-chain or branched alkyl or alkenyl groups having from k to 16 carbon atoms, with or without an asymmetric carbon atom, in which one or more non-adjacent --CH.sub.2 -- groups can be replaced by --O-- and /or --S----A and --B each denote ##STR2## in which the radicals R.sup.1, R.sup.2, in each case, are situated at the phenylene part of --A, --B and m and n denote 0 or 1, but m and n do not simultaneously denote 1, with the following provisos:(a) if m=n=0, k is 8, and in R.sup.2 the --CH.sub.2 -- group adjacent to the phenyl nucleus is replaced by --O--;(b) if m=1 and n=0, k is 2, and(c) if m=0 and n=1, k is 2 and in R.sup.2 the --CH.sub.2 -- group adjacent to the phenyl nucleus is replaced by --O--.
摘要:
Disclosed and claimed are liquid-crystalline cyclopropylalkyl or -alkenyl or heterocyclic compounds, process for their preparation, and their use in liquid-crystalline mixtures. The novel cyclopropylalkyl or -alkenyl or heterocyclic compounds are of the general formula ##STR1## In this formula A.sup.1, A.sup.2 and A.sup.3 are unsubstituted or substituted, aromatic or heteroaromatic molecular components such as 1,4-phenylene or pyrimidine-2,5-diyl which are linked via a single bond (in the case where k and m=0) or via functional groups M.sup.1 and M.sup.2, such as CO--O or CH.sub.2 --O; j, k, l, m and n are zero, 1 or 2. The radicals R.sup.2, R.sup.3 and R.sup.4 are H or alkyl/alkenyl, R.sup.1 is alkyl/alkenyl or one of the substitutents known from LC chemistry such as an .alpha.-haloalkanoic acid radical. At least one of the components A.sup.1, A.sup.2 and A.sup.3 can be heteroaromatic, and G is alkylene or alkenylene.
摘要:
The use of optically active tetrahydrofuran-2-carboxylic acid esters as dopants in liquid-crystal mixtures, liquid-crystal mixtures containing same and novel optically active tetrahydrofuran-2-carboxylic acid esters.Optically active tetrahydrofuran-2-carboxylic acid esters containing a mesogenic molecular building unit are suitable as dopants in liquid-crystal mixtures. They result in liquid-crystalline ferroelectric phases having short switching times and in electroclinic phases having large electroclinic coefficients. A further advantage is that they induce a helix having a very small pitch so that they are also suitable for helix compensation in LC mixtures.The compounds are symbolized by the general formula: ##STR1## in which the symbols and indices essentially denote: R.sup.1 =alkyl/alkenyl or tetrahydrofurancarbonyloxy or -thio; j, l, n=zero, 1 or 2; k, m=zero or 1; --A.sup.1, --A.sup.2, --A.sup.3 =phenylene, cycloalkylene or corresponding heterocyclates containing nitrogen, oxygen or sulfur; --M.sup.1, --M.sup.2 =bridges such as --CO--O, --OCH.sub.2 or --CH.dbd.CH; X=oxygen or sulfur.
摘要:
A process for producing a liquid-crystal cell which comprises the steps of:(a) providing a curable sealant portion in the periphey of the side of an electrode plate that has an electrode or electrodes;(b) (i) coating a ferroelectric liquid-crystal composition on the portion surrounded by said sealant portion, with a spacer being preliminarily provided in said portion;(ii) coating spacer-containing ferroelectric liquid-crystal composition on the portion surrounded by said sealant portion; or(iii) coating a ferroelectric liquid-crystal composition on the portion surrounded by said sealant portion and thereafter providing a spacer over said composition;(c) defoaming the coated layer of the liquid-crystal composition by heating during or after evacuation;(d) placing the other electrode plate in such a way that the side of said other electrode plate which has an electrode or electrodes faces the side of said one electrode plate containing the thermally defoamed coated layer of the liquid-crystal composition and compressing the two electrode plates together; and(e) curing said sealant.