US5332520A
Expired / Lapsed
US
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Liquid-crystalline polymers of virtually uniform molecular weight
Assignee: BASF SE
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Filing: 1992-05-08
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Granted: 1994-07-26
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Expires: 2012-05-08
Abstract
Abstract A liquid-crystalline polymer of virtually uniform molecular weight, obtainable by polymerizing identical or different monomers of the formula I ##STR1## where R is hydrogen, chlorine or methyl, A is a flexible, long-chain moiety which acts as a spacer, is a mesogenic moiety built up from at least two aromatic rings which are linked to one another in a linear or approximately linear manner, and C is an optically active, chiral moiety, in from 0.01 to 0.1 molar solution in an inert organic solvent in the presence of from 1 to 40 mol %, based on the monomers, of a free-radical initiator, at from 40° to 60° C. for from 100 to 140 hours, and subsequently isolating the polymerization product from the reaction mixture, and the use thereof for building up recording layers for laser-optical and electrical recording elements and for electrophotography and for building up liquid-crystalline display elements.
Inventors
- 👤 Volker Bach
- 👤 Karl-Heinz Etzbach
- 👤 Karl Siemensmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:04
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/38; C09K19/3833; C09K19/3842; C09K19/3852; C09K19/3857; C08; C08F; C08F20/00; C08F20/02; C08F20/10; C08F20/26; C08F20/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
124 words
A liquid-crystalline polymer of virtually uniform molecular weight, obtained by polymerizing identical or different monomers of the formula I ##STR16## where R is hydrogen, chlorine or methyl, A is a flexible, long-chain moiety which acts as a spacer, B is a mesogenic moiety built up from at least two aromatic rings which are linked to one another in a linear or approximately linear manner, and C is an optically active, chiral moiety, in from 0.01 to 0.1 molar solution in an inert organic solvent in the presence of from 1 to 40 mol %, based on the monomers, of a free-radical initiator, at from 40° to 60° C. for from 100 to 140 hours, and subsequently isolating the polymerization product from the reaction mixture.
Claim 2
Dependent Claim
124 words
A liquid-crystalline polymer of virtually uniform molecular weight, obtained by polymerizing identical or different monomers of the formula I ##STR16## where R is hydrogen, chlorine or methyl, A is a flexible, long-chain moiety which acts as a spacer, B is a mesogenic moiety built up from at least two aromatic rings which are linked to one another in a linear or approximately linear manner, and C is an optically active, chiral moiety, in from 0.01 to 0.1 molar solution in an inert organic solvent in the presence of from 1 to 40 mol %, based on the monomers, of a free-radical initiator, at from 40° to 60° C. for from 100 to 140 hours, and subsequently isolating the polymerization product from the reaction mixture.
Claim 3
Dependent Claim
131 words
A process for the preparation of a liquid-crystalline polymer of virtually uniform molecular weight, which comprises polymerizing identical or different monomers of the formula I ##STR17## where R is hydrogen, chlorine or methyl, A is a flexible, long chain moiety which acts as a spacer, B is a mesogenic moiety built up from at least two aromatic rings which are linked to one another in a linear or approximately linear manner, and C is an optically active, chiral moiety, in from 0.01 to 0.1 molar solution in an inert organic solvent in the presence of from 1 to 40 mol %, based on the monomers, of a free-radical initiator, at from 40° to 60° C. for from 100 to 140 hours, and subsequently isolating the polymerization product from the reaction mixture.
Claim 4
Dependent Claim
131 words
A process for the preparation of a liquid-crystalline polymer of virtually uniform molecular weight, which comprises polymerizing identical or different monomers of the formula I ##STR17## where R is hydrogen, chlorine or methyl, A is a flexible, long chain moiety which acts as a spacer, B is a mesogenic moiety built up from at least two aromatic rings which are linked to one another in a linear or approximately linear manner, and C is an optically active, chiral moiety, in from 0.01 to 0.1 molar solution in an inert organic solvent in the presence of from 1 to 40 mol %, based on the monomers, of a free-radical initiator, at from 40° to 60° C. for from 100 to 140 hours, and subsequently isolating the polymerization product from the reaction mixture.
Claim 5
Dependent Claim
12 words
A liquid-crystalline polymer according to claim 1 having a non-uniformity of ≦0.1.
Claim 6
Dependent Claim
18 words
A laser-optical decoding element containing as a recording layer a layer of a polymer according to claim 1.
Claim 7
Dependent Claim
18 words
An electrophotographic recording element containing as a recording layer a layer of a polymer according to claim 1.
Claim 8
Dependent Claim
18 words
An electrical recording element containing as a recording layer a layer of a polymer according to claim 1.
Claim 9
Dependent Claim
20 words
A liquid crystalline display element containing as the required crystalline layer a layer of a polymer according to claim 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-07-25 | 1998-01-24 | 1998-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-25 | 2002-01-24 | 2002-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-25 | 2006-01-24 | 2006-07-26 | $7700.00 | Window Closed / Lapsed |