GB1569710A - Liquid crystal arrangements - Google Patents
Liquid crystal arrangements Download PDFInfo
- Publication number
- GB1569710A GB1569710A GB4098376A GB4098376A GB1569710A GB 1569710 A GB1569710 A GB 1569710A GB 4098376 A GB4098376 A GB 4098376A GB 4098376 A GB4098376 A GB 4098376A GB 1569710 A GB1569710 A GB 1569710A
- Authority
- GB
- United Kingdom
- Prior art keywords
- styryl
- general formula
- composition
- liquid crystal
- butyl
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000004973 liquid crystal related substance Substances 0.000 title claims description 18
- 150000001875 compounds Chemical class 0.000 claims description 23
- 239000000975 dye Substances 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 16
- 239000000126 substance Substances 0.000 claims description 15
- 239000000203 mixture Substances 0.000 claims description 14
- 125000000217 alkyl group Chemical group 0.000 claims description 13
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 claims description 12
- 125000004432 carbon atom Chemical group C* 0.000 claims description 9
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 8
- 238000002360 preparation method Methods 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 230000005684 electric field Effects 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 6
- RGHHSNMVTDWUBI-UHFFFAOYSA-N 4-hydroxybenzaldehyde Chemical compound OC1=CC=C(C=O)C=C1 RGHHSNMVTDWUBI-UHFFFAOYSA-N 0.000 claims description 4
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 4
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 4
- NQRYJNQNLNOLGT-UHFFFAOYSA-N Piperidine Chemical compound C1CCNCC1 NQRYJNQNLNOLGT-UHFFFAOYSA-N 0.000 claims description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 125000004430 oxygen atom Chemical group O* 0.000 claims description 4
- 239000000047 product Substances 0.000 claims description 4
- BJDYCCHRZIFCGN-UHFFFAOYSA-N pyridin-1-ium;iodide Chemical compound I.C1=CC=NC=C1 BJDYCCHRZIFCGN-UHFFFAOYSA-N 0.000 claims description 4
- XPLFVKSOXUQPIQ-UHFFFAOYSA-N 6-[2-(1-butylpyridin-4-ylidene)ethylidene]cyclohexa-2,4-dien-1-one Chemical compound C(CCC)N1C=CC(C=C1)=CC=C1C=CC=CC1=O XPLFVKSOXUQPIQ-UHFFFAOYSA-N 0.000 claims description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical group [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 3
- 239000005864 Sulphur Chemical group 0.000 claims description 3
- 230000001747 exhibiting effect Effects 0.000 claims description 3
- 239000003495 polar organic solvent Substances 0.000 claims description 3
- 125000005504 styryl group Chemical group 0.000 claims description 3
- RSJCFBORABJFGA-UHFFFAOYSA-M 1-butyl-4-methylpyridin-1-ium;iodide Chemical compound [I-].CCCC[N+]1=CC=C(C)C=C1 RSJCFBORABJFGA-UHFFFAOYSA-M 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 238000001816 cooling Methods 0.000 claims description 2
- 239000012043 crude product Substances 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 claims description 2
- 238000010992 reflux Methods 0.000 claims description 2
- 230000000694 effects Effects 0.000 description 5
- XLMUTJIBIFYYNN-UHFFFAOYSA-N 4-[5-(4-butylphenyl)-1,3,2-dioxaborinan-2-yl]benzonitrile Chemical compound C1=CC(CCCC)=CC=C1C1COB(C=2C=CC(=CC=2)C#N)OC1 XLMUTJIBIFYYNN-UHFFFAOYSA-N 0.000 description 2
- FKNQCJSGGFJEIZ-UHFFFAOYSA-N 4-methylpyridine Chemical compound CC1=CC=NC=C1 FKNQCJSGGFJEIZ-UHFFFAOYSA-N 0.000 description 2
- HUMNYLRZRPPJDN-UHFFFAOYSA-N benzaldehyde Chemical compound O=CC1=CC=CC=C1 HUMNYLRZRPPJDN-UHFFFAOYSA-N 0.000 description 2
- 210000004027 cell Anatomy 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- KJPRLNWUNMBNBZ-QPJJXVBHSA-N (E)-cinnamaldehyde Chemical compound O=C\C=C\C1=CC=CC=C1 KJPRLNWUNMBNBZ-QPJJXVBHSA-N 0.000 description 1
- 239000004988 Nematic liquid crystal Substances 0.000 description 1
- 239000004990 Smectic liquid crystal Substances 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- -1 alkyl salt Chemical class 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000003098 cholesteric effect Effects 0.000 description 1
- 229940117916 cinnamic aldehyde Drugs 0.000 description 1
- KJPRLNWUNMBNBZ-UHFFFAOYSA-N cinnamic aldehyde Natural products O=CC=CC1=CC=CC=C1 KJPRLNWUNMBNBZ-UHFFFAOYSA-N 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 210000002858 crystal cell Anatomy 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- QNGNSVIICDLXHT-UHFFFAOYSA-N para-ethylbenzaldehyde Natural products CCC1=CC=C(C=O)C=C1 QNGNSVIICDLXHT-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000003381 solubilizing effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K19/00—Liquid crystal materials
- C09K19/52—Liquid crystal materials characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
- C09K19/60—Pleochroic dyes
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
- C09B23/00—Methine or polymethine dyes, e.g. cyanine dyes
- C09B23/0091—Methine or polymethine dyes, e.g. cyanine dyes having only one heterocyclic ring at one end of the methine chain, e.g. hemicyamines, hemioxonol
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Liquid Crystal (AREA)
Description
(54) IMPROVEMENTS IN OR RELATING TO LIQUID CRYSTAL
ARRANGEMENTS
(71) We, THE MARCONI COMPANY LIMITED, a British Company, of
Marconi House, New Street, Chelmsford, Essex, CMl 1PL, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to liquid crystal arrangements, and concerns in particular novel compounds useful as guest materials in liquid crystal substances of the positive nematic type.
It is well known that certain organic substances (mostly substances the molecules of which are highly polar and show a considerable difference in their length/breadth dimensions and physical properties) can behave, with regard to some of their physical properties, as though they were a state of matter intermediate that of the anisotropic solid (usually crystalline) and the isotropic liquid states. This state of matter is known as the mesophase, and the substances in it are called mesogens -- or, loosely, liquid crystals.
Liquid crystal substances can be of the nematic, smectic or cholesteric class (depending on the degree of order exhibited by their molecules when in the mesophase), and the nematic materials in particular have proved of especial interest as a result of their ability to transmit or to scatter light in a manner dependent on how the molecules arrange themselves in the presence (or in the absence) of an appropriate electric field.This ability has enabled nematic liquid crystal substances to be used, in a variety of ways, as a light switch - for example, a cell of the substance in the absence of the electric field might transmit light, and in the presence of the field might block it - and this effect is particularly available when constructing the cell using as the liquid crystal substance a positive nematogen (that is, a nematic substance which orders itself lined up along the applied field, and thus displays positive dielectric anisotropy)
In a number of these switching applications it is desirable for the liquid crystal cell to exhibit a colour change effect; one way of obtaining such an effect is to disperse within the liquid crystal substance a suitable dichroic dye (a dye the molecules of which, because of their configuration, are capable upon being oriented -- rather like the mesogen/liquid crystal substance itself - of displaying effects with regard to the dye's transmission or reflection of light which are dependent upon the mode of polarisation of that light).These dichroic dyes are known, in this context, as "guest materials" (the liquid crystal substance is the "host material") and, as is well appreciated, for any particular dichroic dye to be of value as a guest material it should meet the following criteria: a) It should have a high dichroic ratio (that is to say, there should be a considerable difference in the dye molecule's capability to absorb or transmit light passing along the length of the molecule as compared with light passing across the molecule).
b) Its order parameter, S, should be high (S is a measure of the molecule's ability to remain aligned in an electric field despite thermal agitation effects acting to destroy that alignment).
c) It must have sufficient solubility in the positive nematogen used.
d) It should exhibit a long-term stability towards the application of strong electric fields.
At the present time the guest dichroic dyes in common usage have been mostly of the azo class, but for a number of reasons they have not proved entirely acceptable. We have now found that certain compounds belonging to a different class of dyes - the styryl dyes -- appear to be more satisfactory. These styryl-type compounds are those of the general formula:
(wherein:
R and R1 each represents a straight-chain alkyl group,
n represents zero or an integer; and
X represents an oxygen or sulphur atom or a group
wherein Y is an oxygen or sulphur atom).
In one aspect, therefore, this invention provides a liquid crystal composition comprising a liquid crystal substance, capable of exhibiting the electric field switching phenomenon associated with positive nematic "guest-host" phase change systems, having dispersed therein as a guest material one or more styryltype dichroic dye of the general formula I or II as defined herein.
The liquid crystal component of the compositions of the invention may be any of those positive nematogens used or suggested for use in this field, and there is no need here to discuss the matter further.
The particular significance of the choice of styryl-type dichroic dye compounds I or II - the other component of the compositions of the invention lies in the solubilizing effect of the alkyl groups and the value of n combined with the high value of their dichroic ratio and order parameter S. Most preferably the alkyl groups R and R1 are each such groups having at least 4, and perhaps as many as 20, carbon atoms in the chain, while n is conveniently 0, 1 or 2.
An example of such a styryl-type dichroic dye is l-n-butyl-4-([4- oxocyclohexadienylidene]-ethylidene)-1,4-dihydropyridine; this is a compound of formula I wherein R is n-butyl, n, is zero, and X is oxygen.
The styryl-type dichroic dye I or II may be prepared by any suitable process used, or suggested for use, for the preparation of such compounds. One such process involves a two-stage reaction, in which:
a) an appropriate 4-methyl-N-alkyl-pyridinium salt (conveniently prepared in a preliminary stage by quaternising 4-methyl-pyridine with an appropriate alkyl salt), or the appropriate 2-methyl-N-alkyl-benzthiazole, is condensed with the appropriate 4-substituted-phenyl-polyenal to give as an intermediate the quaternised version of the desired final compound I or II; and
b) the formed intermediate is then dequaternised to give the desired final compound I or II.
The 4-methyl-N-alkyl-pyridinium salt is conveniently the iodide.
The exact nature of the 4-substituted-phenyl-polyenal depends, of course, upon the value of n. For n =0 the phenyl-polyenal is a benzaldehyde, while for n = is is a cinnamaldehyde.
The condensation reaction is effected in the presence of a strong base (for example, an organic nitrogenous base such as triethylamine or piperidine), and in the presence of a polar organic solvent (for example, an alkanol such as ethanol), with heating (preferably at reflux).
The subsequent dequaternisation reaction is conveniently effected using concentrated aqueous ammonia as the dequaternising agent.
The compounds of general formula I or II are novel; these novel compounds are claimed herein per se together with the processes described herein for their preparation. Naturally, the invention also exends to the compounds when thus prepared.
The following Example is now given, though only by way of illustration, to show details of one embodiment of the invention.
Example.
Preparation of 1 -n-butyl-4-([4-oxo-cyclohexadienylidene] -ethylidene)- 1,4dihydropyridine
Stage A: 2.8g of 4-methyl-N-n-butyl-pyridinium iodide (0.1 mole) and 1.22g of 4-hydroxy-benzaldehyde (0.1 mole) were refluxed in 20ml of ethanol in the presence of 5 mole per cent triethylamine. After cooling, the pyridinium iodide product was filtered off, and washed with a minimum of ether.
Stage B: The formed pyridinium iodide was treated with concentrated aqueous ammonia, and the crude product was recrystallised first from aqueous methanol, and then from ligroin (l000-l200C), to give the desired l-n-butyl-4-([4 oxocyclohexadienylidene]-ethylidene)- 1 ,4-dihydropyridine.
In British patent Specification No. 1,370,263 there are disclosed a number of styryl-pyridines and styryl-benzthiazoles, some of which fall within general formula
I or II as defined herein. Accordingly, no per se claim is made herein to any compound of general formula I wherein R represents a straight-chain alkyl group having from 1 to 6 carbon atoms, n is zero and X represents an oxygen atom, nor is any per se claim made herein to any compound of general formula II wherein Rl represents a straight-chain alkyl group having from 1 to 3 carbon atoms, n is zero and X represents an oxygen atom. In addition, no claim is made herein to the process defined herein for the preparation of any of these disclaimed compounds, or to the product of such a process.
Subiect to the foregoing disclaimer, WHAT WE CLAIM IS:
1. A liquid crystal composition comprising a liquid crystal substance, capable of exhibiting the electric field switching phenomenon associated with positive nematic "guest-host" phase change systems, having dispersed therein as a guest material one or more styryl-type dichroic dye of the general formula
(wherein:
R and R' each represents a straight-chain alkyl group;
n represents zero or an integer; and
X represents an oxygen or sulphur atom, or a group
wherein Y is an oxygen or sulphur atom).
2. A composition as claimed in claim 1, wherein the styryl-type dyes I or II are those where the alkyl groups R and R' are each such groups having at least 4 carbon atoms in the chain.
3. A composition as claimed in claim 2, wherein the alkyl groups R and R1 contain up to 20 carbon atoms in the chain.
4. A composition as claimed in any of the preceding claims, wherein the styryltype dyes are such that n is 0,1 or 2.
5. A composition as claimed in any of the preceding claims, wherein the styryl
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (14)
1. A liquid crystal composition comprising a liquid crystal substance, capable of exhibiting the electric field switching phenomenon associated with positive nematic "guest-host" phase change systems, having dispersed therein as a guest material one or more styryl-type dichroic dye of the general formula
(wherein:
R and R' each represents a straight-chain alkyl group;
n represents zero or an integer; and
X represents an oxygen or sulphur atom, or a group
wherein Y is an oxygen or sulphur atom).
2. A composition as claimed in claim 1, wherein the styryl-type dyes I or II are those where the alkyl groups R and R' are each such groups having at least 4 carbon atoms in the chain.
3. A composition as claimed in claim 2, wherein the alkyl groups R and R1 contain up to 20 carbon atoms in the chain.
4. A composition as claimed in any of the preceding claims, wherein the styryltype dyes are such that n is 0,1 or 2.
5. A composition as claimed in any of the preceding claims, wherein the styryl
type dye is 1 - n - butyl - 4 ([4 - oxocyclohexadienylidene] - ethylidene) - 1,4 dihydropyridine.
6. A composition as claimed in any of the preceding claims and substantially as described hereinbefore.
7. A styryl-type dye, having the general formula I or II as defined in any of the preceding claims.
8. A process for the preparation of a styryl-type dye I or II as claimed in claim 7, in which:
a) an appropriate 4-methyl-N-alkyl-pyridinium salt, or the appropriate 2methyl-N-alkyl-benzthiazole, is condensed, with heating in a polar organic solvent and in the presence of a strong base, with the appropriate 4-substituted-phenylpolyenal to give as an intermediate the quaternised version of the desired final compound I or II; and
b) the formed intermediate is then dequaternised to give the desired final compound I or II.
9. A process as claimed in claim 8, in which the 4-methyl-N-alkyl-pyridinium salt is the iodide.
10. A process as claimed in either of claims 8 and 9, in which the strong base is triethylamine or piperidine.
11. A process as claimed in any of claims 8 to 10, in which the polar organic solvent is ethanol, and the reaction is effected at reflux.
12. A process as claimed in any of claims 8 to 11, in which the subsequent dequaternisation reaction is effected using concentrated aqueous ammonia as the dequaternising agent.
13. A process as claimed in any of claims 8 to 12 and substantially as described hereinbefore.
14. A styryl-type compound I or II whenever prepared by a process as claimed in any of claims 8 to 13.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4098376A GB1569710A (en) | 1977-08-05 | 1977-08-05 | Liquid crystal arrangements |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4098376A GB1569710A (en) | 1977-08-05 | 1977-08-05 | Liquid crystal arrangements |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1569710A true GB1569710A (en) | 1980-06-18 |
Family
ID=10417563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4098376A Expired GB1569710A (en) | 1977-08-05 | 1977-08-05 | Liquid crystal arrangements |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1569710A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4324455A (en) * | 1979-09-11 | 1982-04-13 | Mitsubishi Chemical Industries Limited | Liquid crystal composition |
| US4448492A (en) * | 1982-12-23 | 1984-05-15 | Minnesota Mining And Manufacturing Company | Cycloalkyl-type isotropic dyes for liquid crystal display devices |
| US4452511A (en) * | 1982-12-30 | 1984-06-05 | Minnesota Mining And Manufacturing Company | Substituted anthracene-type isotropic dyes for liquid crystal display devices |
-
1977
- 1977-08-05 GB GB4098376A patent/GB1569710A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4324455A (en) * | 1979-09-11 | 1982-04-13 | Mitsubishi Chemical Industries Limited | Liquid crystal composition |
| US4448492A (en) * | 1982-12-23 | 1984-05-15 | Minnesota Mining And Manufacturing Company | Cycloalkyl-type isotropic dyes for liquid crystal display devices |
| US4452511A (en) * | 1982-12-30 | 1984-06-05 | Minnesota Mining And Manufacturing Company | Substituted anthracene-type isotropic dyes for liquid crystal display devices |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |