Nippon Soken, Inc.

Denso Corporation

Hitoshi Hayashi

Kenji Takigawa

Katsuhide Kikuchi

Yoshimasa Hijikata

Akira Takeuchi

Tetsuo Toyama

Naohisa Oyama

An air conditioning system comprising a gas-impermeable wall defining a space for air conditioning, and a selective separating member disposed in the wall as a part of the wall, having a function of allowing preferential permeation of oxygen and carbon dioxide and at the same time, blocking the permeation of hydrocarbon, nitrogen oxide, sulfur oxide and a fine solid component, in which the selective separating member comprises an organic polymer and satisfies the relationship of P1/P2&#x3e;10 wherein P1 is the permeation coefficient of oxygen and carbon dioxide and P2 is the permeation coefficient of hydrocarbon, nitrogen oxide, sulfur oxide and a fine solid component.

Air conditioning system

An antiferroelectric liquid crystal composition having a chiral smectic C,* phase composed by blending liquid crystal composition-constituting compounds having the same direction of inclination of optic axis produced by application of an electric field and/or comprised of a mixture of two enantiomers of a liquid crystal material; one having the stereosense (&plus;) and the other having the stereosense (&minus;). The stereosense is defined so that, when the molecule is viewed so that the bond between the core group and the asymmetric carbon is behind the asymmetric carbon atom, the stereosense is (&plus;) if the remaining three groups (or atoms) are arranged clockwise in order of length of the groups (or, if the groups are the same length, in order of their volume), and the stereosense is (&minus;) if the groups are arranged counter clockwise.

Antiferroelectric liquid crystal composition

The present invention discloses an antiferroelectric liquid crystal composition respectively containing the compounds of formula (1), (2), (3) or (4), wherein R.sub.1, R.sub.3, R.sub.5 and R.sub.7 are alkyl groups having 7-13 carbon atoms, R.sub.2, R.sub.4, R.sub.6 and R.sub.8 are alkyl groups having 4-8 carbon atoms, any of the four hydrogen atoms in each of the phenyl groups of the formulas may be substituted with a halogen atom such as F, Cl or Br, or a CH.sub.3 group, and X indicates --O-- or --. ##STR1##

An antiferroelectric composition comprising 70 wt % or more of a mixture consisting of two groups of compounds represented by the following general formula (I): ##STR1## wherein each of R, R.sup.1, R.sup.2 and R.sup.3 are an atom or an atomic group, R is an atomic group having the most carbon atoms, C* represents an asymmetric carbon, R.sup.1, R.sup.2, and R.sup.3 are numbered in order of increasing number of carbon atoms (i.e. R.sup.1 &lt;R.sup.2 &lt;R.sup.3), or, if two or more groups have the same number of carbon atoms, they are numbered in order of increasing atomic group weight or increasing atomic weight, and wherein one component of the mixture has R.sup.1, R.sup.2 and R.sup.3 arranged clockwise when the molecule is viewed along the R--C bond, with the C* atom in front, and the other, counterclockwise. The composition provides an antiferroelectric liquid crystal composition having a lower crystal temperature and a wide liquid crystal temperature range with a small number of component compounds.

Antiferroelectric liquid crystal composition and liquid crystal

Antiferroelectric liquid crystal compositions which employ mixtures of antiferroelectric liquid crystal compounds represented by general formulas (1) and (2), and also antiferroelectric liquid crystal compounds represented by general formula (3). ##STR1## wherein R.sub.1 -R.sub.6 are alkyl groups, and one or more of the 4 hydrogen atoms of each of the phenyl groups in the formulas may be replaced with a fluorine atom.

An antiferroelectric liquid crystal composition comprising a liquid crystal composition having the chiralsmectic C.sub.A phase and a compound represented by the formula (I) shown below: ##STR1## wherein X is --CH.sub.3, --CF.sub.3 or --C.sub.2 H.sub.5 ; R.sup.1 and R.sup.2 are straight-chain or branched alkyl radicals having 3 to 14 and 3 to 10 carbon atoms respectively; Y represents a single bond, or --O--, --CO--, --COO-- or --OCO-- radical; Z represents --COO--, --C.tbd.C-- or --CH.sub.2 CH.sub.2 -- radical; and A.sup.1, A.sup.2 and A.sup.3 independently represent a six membered ring including benzene rings, cyclohexane rings, pyridine rings, and pyrimidine rings, at least one hydrogen of which six membered rings may be replaced by a fluorine atom, chlorine atom, bromine atom, cyano group, nitro group, methyl group, ethyl group or methoxy group.

Antiferroelectric liquid crystals represented by the following formula (1) and (2). ##STR1## In the formula (1), each of m and n is an integer satisfying 6.ltoreq.m.ltoreq.14 and 2.ltoreq.n.ltoreq.10, and each of Z.sub.1, Z.sub.2 and Z.sub.3 is independently a substituent selected from the group consisting H, F, Cl, Br, CN and CH.sub.3. ##STR2## In the formula (2), each of m and n is an integer satisfying 6.ltoreq.m.ltoreq.14 and 3.ltoreq.k.ltoreq.10, and each of Z.sub.1, Z.sub.2 and Z.sub.3 is independently a substituent selected from the group consisting H, F, Cl, Br, CN and CH.sub.3.

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Okazaki, Japan

Hitoshi Hayashi