US4952661A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermotropic liquid crystalline polyester from 2,5-dihydroxybenzophenone
Assignee: Montedison SpA
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Filing: 1989-12-06
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Granted: 1990-08-28
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Expires: 2009-12-06
Abstract
Abstract Thermotropic liquid crystalline polyesters which can be processed in the molten state containing moieties derived from a dicarboxylic aromatic acid and 2,5-dihydroxybenzophenone eventually in a mixture with a substituted hydroquinones.
Inventors
- 👤 Marco Foa'
- 👤 Francesco Casagrande
- 👤 Alfredo Coassolo
- 👤 L. Lawrence Chapoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:25
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/16; C08G63/18; C08G63/19; C08G63/193; C09; C09K; C09K19/00; C09K19/04; C09K19/38; C09K19/3804; C09K19/3809
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
66 words
Thermotropic liquid crystalline polyester optically anisotropic in the melted state comprising: (a) at least one moiety derived from a dicarboxylic aromatic acid; (b) one moiety derived from 2,5-dihydroxybenzophenone; and (c) optionally at least one moiety derived from substituted hydroquinones of the general formula: ##STR3## in which R represents an atom of halogen or an alkyl, aryl, or aralkyl radical containing from 1 to 18 carbon atoms.
Claim 2
Dependent Claim
66 words
Thermotropic liquid crystalline polyester optically anisotropic in the melted state comprising: (a) at least one moiety derived from a dicarboxylic aromatic acid; (b) one moiety derived from 2,5-dihydroxybenzophenone; and (c) optionally at least one moiety derived from substituted hydroquinones of the general formula: ##STR3## in which R represents an atom of halogen or an alkyl, aryl, or aralkyl radical containing from 1 to 18 carbon atoms.
Claim 3
Dependent Claim
25 words
A polyester according to claim 1, wherein at least 90 mole percent of the dicarboxylic aromatic acid moiety is present in the para isomeric from.
Claim 4
Dependent Claim
36 words
A polyester according to claim 1, wherein the dicarboxylic aromatic acid is terephthalic acid, optionally substituted by at least one halogen atom, methylterephthalic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid or 4,4-diphenyldicarboxylic acid.
Claim 5
Dependent Claim
38 words
A polyester according to claim 1, wherein the substituted hydroquinone when present is a chlorine or bromine substituted hydroquinone, methyl hydroquinone, ethylhydroquinone, propylhydroquinone, t-butylhydroquinone, 2-phenylhydroquinone, 2-phenethyl hydroquinone, 2-(1-methyl-1-phenethyl) hydroquinone, 2-(4-methylbenzyl) hydroquinone, (1-naphthyl-methyl) hydroquinone, (2-naphthylmethyl) hydroquinone, or (triphenylmethyl) hydroquinone.
Claim 6
Dependent Claim
42 words
A polyester according to claim 1, wherein the moieties derived from the dicarboxylic aromatic acid are in stoichiometric ratio with the diols of moieties (b) and (c) while the latter are used with a c/b molar ratio of from 0 to 2.4.
Claim 7
Dependent Claim
16 words
A polyester according to claim 5, wherein the c/b molar ratio is from 0.1 to 2.4.
Claim 8
Dependent Claim
33 words
A polyester according to claim 1, wherein the polyester contains the following repetitive moieties: ##STR4## in which the molar ratio II/III+IV) is 1, while the molar ratio II/IV varies from 0 to 2.4.
Claim 9
Dependent Claim
16 words
A polyester according to claim 1, wherein the molar ratio III/IV varies from 0.1 to 2.4.
Claim 10
Dependent Claim
48 words
Polyesters according to claim 1, wherein the polyester has a melting point of between 240° and 330° C. and an inherent viscosity of between 0.3 and 4 measured in a 1:1 mixture of acetic acid trifluoride and methylene chloride at 30° C. and a concentration of 2.5 g/l.
Claim 11
Dependent Claim
23 words
A fiber, film, injection- or extrusion-molded product, or matrix for fiber- or filler-based composites, when made of a polyester according to claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |