Patent US4324880A successfully refreshed from Google Patents.
US4324880A
Expired / Lapsed
US
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β-Hydroxybutyric acid polyesters, a process for their production and their use as starting materials for lacquers
Assignee: Bayer AG
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Filing: 1980-11-24
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Granted: 1982-04-13
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Expires: 2000-11-24
Abstract
Abstract Polyesters having a hydroxyl number of from 50 to 400 and containing 20 to 90% by weight of co-condensed beta -hydroxybutyric acid units have proved to yield transparent, glossy, elastic and hard coatings.
Inventors
- 👤 Rolf Dhein
- 👤 Knud Reuter
- 👤 Hans Rudolph
- 👤 Jorg Pfitzner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:52
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/42; C08G18/4266; C08G18/4283; C08G18/4269; C08G63/00; C08G63/02; C08G63/60; C09; C09D; C09D167/00; C09D167/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
71 words
Polyesters having a hydroxyl number of from 50 to 400 and containing co-condensed β-hydroxycarboxylic acid units, characterised in that the polyesters contain from 20 to 90% by weight of co-condensed units corresponding to the following formula ##STR2## in which n has an average value of from 1 to 15, and from 80 to 10% by weight of co-condensed residues of polyols and optionally monohydric alcohols, mono- or polycarboxylic acids and diisocyanates.
Claim 2
Dependent Claim
71 words
Polyesters having a hydroxyl number of from 50 to 400 and containing co-condensed β-hydroxycarboxylic acid units, characterised in that the polyesters contain from 20 to 90% by weight of co-condensed units corresponding to the following formula ##STR2## in which n has an average value of from 1 to 15, and from 80 to 10% by weight of co-condensed residues of polyols and optionally monohydric alcohols, mono- or polycarboxylic acids and diisocyanates.
Claim 3
Dependent Claim
19 words
Polyesters as claimed in claim 1, characterised in that they have a hydroxyl number of from 100 to 350.
Claim 4
Dependent Claim
50 words
Polyesters as claimed in claim 1 or 2, characterised in that they contain from 40 to 70% by weight of the co-condensed units corresponding to the following formula: ##STR3## and from 60 to 30% by weight of co-condensed residues of polyols and/or monohydric alcohols, mono- or poly-carboxylic acids and diisocyanates.
Claim 5
Dependent Claim
21 words
Polyesters as claimed in claims 1 or 2, characterised in that n has an average value of from 3 to 9.
Claim 6
Dependent Claim
41 words
A process for producing the polyesters as claimed in claims 1 or 2, characterised in that poly-β-hydroxybutyric acid and polyols and optionally monohydric alcohols, mono- or poly- carboxylic acids and diisocyanates are transesterified with one another at 150° to 190° C.
Claim 7
Dependent Claim
40 words
A process as claimed in claim 5, characterised in that, in the first stage of the reaction, poly-β-hydroxybutyric acid is transesterified with polyalcohol after which the reaction mixture obtained is esterified with mono- or poly-carboxylic acids, diisocyanates and/or monohydric alcohols.
Claim 8
Dependent Claim
10 words
A lacquer containing the polyester of claims 1 or 2.
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) | 1985-04-12 | 1985-10-12 | 1986-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-12 | 1989-10-12 | 1990-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-12 | 1993-10-12 | 1994-04-13 | $7700.00 | Window Closed / Lapsed |