A process for effectively producing a 4-(4-alkylcyclohexyl)benzaldehyde, 4-(cyclohexyl)benzaldehyde, a 4-(trans-4-alkylcyclohexyl)benzaldehyde and a (trans-4-alkylcyclohexyl)benzene useful for electronic material applications such as liquid crystals and for pharmaceutical and agrochemical applications, etc., are disclosed. The present invention provides (1) a process for producing a 4-(4-alkylcyclohexyl)benzaldehyde or 4-(cyclohexyl)benzaldehyde by formylating a (4-alkylcyclohexyl)benzene or cyclohexylbenzene with carbon monoxide, (2) a process for producing a 4-(trans-4-alkylcyclohexyl)benzaldehyde by formylating a (4-alkylcyclohexyl)benzene having a cis/trans molar ratio of 0.3 or less with carbon monoxide, and (3) a process for producing a (trans-4-alkylcyclohexyl)benzene by isomerizing a mixture of the cis and trans isomers of a (4-alkylcyclohexyl)benzene, all of the processes being performed in the presence of HF and BF
3
.
A liquid crystal compound and a mixture containing the same
申请人:Chisso Corporation
公开号:EP0325796A1
公开(公告)日:1989-08-02
A liquid crystalline compound and a liquid crystal composition containing the compound usable for liquid crystal display devices are provided, which liquid crystalline compound is expressed by the formula
wherein R1 is H or 1-20C alkyl or alkenyl wherein one -CH2- group or two -CH2- groups not adjacent to each other may be substituted by -0-; the position and number of the double bond may be optionally chosen; A1, A2 and A3 each are
and the H of the
may be substituted by F, Cℓ or methyl; B1 and B2 each are -CH2CH2-, -CH20-, -OCH2 or a single bond; n is 0 or 1; and m is 0-20.
Flüssigkristalline Derivate von stickstoffhaltigen heterocyclischen Systemen als Komponenten eines flüssigkristallinen Materials und ein flüssigkristallines Material
申请人:PAVLJUCHENKO, Assya Iosifovna
公开号:EP0374849A2
公开(公告)日:1990-06-27
Vorgeschlagen werden neue flüssigkristalline Derivate von stickstoffhaltigen heterocyclischen Systemen der allgemeinen Formel R1-A1-Z-A2-R2 (1) worin R1 und R2 gleichzeitig oder unabhängig CnH2n+1, -CmH2m+1, CnH2n+1O-, CmH2m+1O-, CH2=CH(CH2)k-,-CN, -N=C=S,-Hal,
bei k = 0-3, 1 = 0-2: m, n = 1-15 sind: Z = -CH2-CH2-, -CH=CH-, -C≡C, -COO-, Einfachbindung ist; wobei falls
ist, so A2
ist; falls A2
ist, so A1
darstellt. R - CH3,-CN, -CI, -F ist, 1 0 bis 2 beträgt, als Komponenten eines flüssigkristallinen Materials. Das erfindungsgemäße flüssigkristalline Material enthält wenigstens zwei Komponenten, von denen wenigstens die eine ein flüssigkristallines Derivat des stickstoffhaltigen heterozyklischen Systems der allgemeinen Formel 1 in einer Menge von 1 bis 50 Masse-% darstellt.
A liquid crystal compound having a relatively low viscosity, a superior compatibility with other liquid crystalline compounds and suitable for preparing a liquid crystal device having a high response rate, and a superior liquid crystal composition containing the compound are provided, which compound is expressed by the formula
wherein R¹ is H, F, Cℓ, CN or 1-20C alkyl or alkenyl in which alkenyl one -CH₂- group or two not-adjacent -CH₂- groups may be replaced by -O- and in which alkenyl the position and number of the double bond may be optionally chosen; A¹, A² and A³ are
the H atom(s) of which
may be replaced by F, Cℓ or methyl; B¹ and B² are -CH₂CH₂-, -CH₂O-, -OCH₂- or single bond; n is 0 or 1; and m is 0 to 20.
Tolan derivatives, liquid crystal compositions containing them, and liquid crystal elements using them
申请人:SEIKO EPSON CORPORATION
公开号:EP0442266A1
公开(公告)日:1991-08-21
The present invention resides in novel compounds represented by the general formula:
wherein R indicates a straight chain alkyl group having 1 to 10 carbon atoms, A represents either
or single bond, and X represents hydrogen or fluorine, provided that the cyclohexane ring has the trans configuration, and liquid crystal compositions containing them. The compounds of the present invention have the following characteristics.
1. The anisotropy of dielectric constant Δε is positive and very large.
2. The anisotropy of double refraction Δn is large.
3. The nematic-isotopic liquid transition point (N-I point) is high.
Therefore, the use of a liquid crystal composition containing the compound of the present invention can provide a liquid crystal display device having the following characteristics.
1. The driving voltage is low.
2. The response speed is high.
3. The temperature range for practical use is wide.