EP0350842A2
Expired / Lapsed
EP
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Pyramidal liquid crystals
Assignee: Montedison SpA
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Filing: 1989-07-10
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Granted: —
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Expires: 2009-07-10
Abstract
Abstract Dodeca-substituted derivatives of macrocyclic tetramers, obtained by acid-catalyzed condensation of pyrogallol and an aliphatic aldehyde, wherein the substituents are alkanoyl groups, are described. These substituted tetramers are optically anisotropic in the molten state and, in particular, show mesophases of the pyramidal type.
Inventors
- 👤 Enrico Dalcanale
- 👤 Stefanio Bonsignore
- 👤 Giuseppe Cometti
- 👤 Annick Du Vosel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 12:55
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/06; C09K19/32; C07; C07C; C07C37/00; C07C37/11; C07C37/115; C07C2603/00; C07C2603/92
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
55 words
Thermotropic dodeca-substituted macrocyclic tetramers of the general formula: wherein the groups R are alkyl radicals containing 1 or 2 carbon atoms and the groups R′, the same or different from each other, represent a radical of the general formula -CO-C n H 2n+1 (II) wherein n is an integer greater than or equal to 12.
Claim 2
Dependent Claim
55 words
Thermotropic dodeca-substituted macrocyclic tetramers of the general formula: wherein the groups R are alkyl radicals containing 1 or 2 carbon atoms and the groups R′, the same or different from each other, represent a radical of the general formula -CO-C n H 2n+1 (II) wherein n is an integer greater than or equal to 12.
Claim 3
Dependent Claim
15 words
Tetramers according to claim 1, wherein n is an integer of from 12 to 30.
Claim 4
Dependent Claim
16 words
Tetramers according to claim 1 or 2, wherein all of the radicals R′ are the same.
Claim 5
Dependent Claim
35 words
Tetramers according to any one of the preceding claims having melting temperatures of from about 30°C to about 100°C and isotropization temperatures in the molten state (clearing points) of from about 60°C to about 120°C.
Claim 6
Dependent Claim
22 words
Tetramers according to any one of the preceding claims, wherein the monophase is of the hexagonal column shaped type with pyramidal arrangement.
Claim 7
Dependent Claim
32 words
Use of the tetramers according to any one of the preceding claims as components of "memory devices", in optoelectronic displays and in the field of phototonics as components of non-linear optical devices.
Claim 8
Dependent Claim
49 words
Process for the preparation of macrocyclic tetramers of the general formula: wherein R is defined as in claim 1, comprising the reaction, at room temperature, of pyrogallol and an acetal of an aliphatic aldehyde in the presence of an acidic catalyst and in a polar solvent, preferably an alcohol.
Claim 9
Dependent Claim
40 words
Process according to claim 7, wherein the acetal of the aliphatic aldehyde has the general formula: wherein R is a C₁-C₂ alkyl radical and R˝ is an alkyl, cycloalkyl, aryl or alkylaryl radical containing from 1 to 30 carbon atoms.
Claim 10
Dependent Claim
23 words
Process according to claim 7 or 8, wherein the catalyst is selected from hydrochloric acid, sulfonic acid, phosphoric acid and p-toluene sulfonic acid.
References Cited (Backward Citations)
No citation records indexed.
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