US4927883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of crosslinked poly β-alanine in the form of microspheres
Assignee: L'Oréal SA
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Filing: 1988-12-13
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Granted: 1990-05-22
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Expires: 2008-12-13
Abstract
Abstract A process for preparing crosslinked poly beta -alanine in the form of microspheres comprises (a) polymerizing acrylamide in a tert. butanol/toluene solvent mixture in the presence of a polymerization initiator and an octadecene-maleic anhydride copolymer as a suspension agent; (b) submitting the resulting suspension of poly beta -alanine to a crosslinking reaction using a dialdehyde as the crosslinking agent; and (c) isolating the crosslinked poly beta -alanine microspheres. These microspheres exhibit a low size dispersity.
Inventors
- 👤 Claudine Lapoiriere
- 👤 Claude Mahieu
- 👤 Christos Papantoniou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:30
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/48; C08G69/50; C08F; C08F8/00; C08F8/28; C08F8/48; C08F2810/00; C08F2810/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
88 words
A process for preparing crosslinked poly β- alanine in the form of microspheres having a low size dispersity comprising (a) polymerizing acrylamide in a tert. butanol/toluene solvent mixture, wherein the ratio of tert. butanol to toluene ranges from 1.24 to 10:1, in the presence of a polymerization initiator and an octadecene-maleic anhydride copolymer as a suspension agent; (b) submitting the resulting suspension of poly β- alanine microspheres to a crosslinking reaction using a dialdehyde as the crosslinking agent; and (c) isolating the resulting crosslinked poly β- alanine microspheres.
Claim 2
Dependent Claim
88 words
A process for preparing crosslinked poly β- alanine in the form of microspheres having a low size dispersity comprising (a) polymerizing acrylamide in a tert. butanol/toluene solvent mixture, wherein the ratio of tert. butanol to toluene ranges from 1.24 to 10:1, in the presence of a polymerization initiator and an octadecene-maleic anhydride copolymer as a suspension agent; (b) submitting the resulting suspension of poly β- alanine microspheres to a crosslinking reaction using a dialdehyde as the crosslinking agent; and (c) isolating the resulting crosslinked poly β- alanine microspheres.
Claim 3
Dependent Claim
24 words
The process f claim 1 where in said tert. butanol/toluene solvent mixture, the ratio of tert. butanol to toluene ranges from 1.6 to 6:1.
Claim 4
Dependent Claim
27 words
The process of claim 1 wherein said polymerization initiator is sodium tert. butylate present in an amount of 0.1 to 2 moles/percent in regard to said acrylamide.
Claim 5
Dependent Claim
33 words
The process of claim 1 wherein said dialdehyde is glutaraldehyde, in a 20-25 percent aqueous solution, and employed in an amount ranging from 1 to 15 weight percent relative to the initial acrylamide.
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) | 1993-05-21 | 1993-11-20 | 1994-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-21 | 1997-11-20 | 1998-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-21 | 2001-11-20 | 2002-05-22 | $7700.00 | Window Closed / Lapsed |