Patent · US Expired

Smectic A liquid crystal compositions

US4834906A · kind A · utility

8Cited by
11References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 22, 1986
Grant dateMay 30, 1989
Priority date
Expiry dateSep 22, 2006

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC09K19/42
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

Liquid crystal compositions comprising as a first part between 40 and 99% by weight in aggregate of one or more materials selected from one or more of the six compound classes (1) to (3'), wherein R is in every instance an alkyl chain containing between 2 and 18 carbon atoms and R' is in every instance an alkyl chain containing between 1 and 17 carbon atoms, wherein one or more non-adjacent CH.sub.2 -groups are replaced by oxygen atoms, and as a second part between 1 and 60% by weight of one or more materials of high birefringence and high positive dielectric anisotropy which raise the S.sub.A -N transition temperature, exhibit a smectic A phase of relatively low melting point and wide smectic range. Such compositions may be used in liquid crystal cells, not only in display or optical information processing applications, but also for instance in temperature sensing applications. The operation of such cells may involve laser addressing, thermal or electrical addressing. ##STR1##

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.