Liquid crystal materials and devices

US6277451A · kind A · utility

Assignee

• The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland · GB

Inventors

• Georg Mehl · Hull, GB
• John William Goodby · Hope, GB

Key dates

• Filing date: Aug 21, 1998
• Grant date: Aug 21, 2001
• Expiry date: Aug 21, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K2323/00
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Materials of formula (I): [G].sub.g (SiO.sub.1/2).sub.x are described where G is R.sub.3 SiR.sub.1 R.sub.2 (O).sub.k ; R.sub.1, R.sub.2, R.sub.3 are independently a C.sub.1-16 alkyl which may be partly or fully halogenated, H and formula (IA), wherein Y is selected from COO, OCO, O, S, CHOH, CHF, CH.sub.2 ; Q=(CH.sub.2).sub.n where one or more non-adjacent methylenes may be replaced by O and n=1=20; Z is O, S, a single covalent bond, COO, OCO; when Y is CH.sub.2, then n may also be 0; ##STR1## PA1 (a) represents any mesogenic group; provided that at least one of R.sub.1, R.sub.2, R.sub.3, is selected from formula (IA): ##STR2## PA1 k=0 or 1; g=4 or 6 or 8 or 10 or 12; 1=3 or 8 provided that: if k=1, 1=3 and x is selected form 6, 8, 10, 12 then g=x; if k=0, 1=8 and g=4 then x=1; and further provided that G may have up to g different structures for any single compound. Pyroelectric and piezoelectric devices, liquid crystal electro-optical display devices and optical recording media containing the adsorbed liquid crystals mixed with other liquid crystal materials are described.