US5310905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conversion of nylon 6 and/or nylon 6,6 to monomers
Assignee: Invista North America LLC
•
Filing: 1993-04-14
•
Granted: 1994-05-10
•
Expires: 2013-04-14
Abstract
Abstract Waste nylon 6 and/or nylon 6,6 are treated with aliphatic monocarboxylic acid to depolymerize the polymer to desirable monomer.
Inventors
- 👤 Edward F. Moran, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:09
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/02; C07D201/12; C07C; C07C51/00; C07C51/347; C07C55/00; C07C55/02; C07C55/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
89 words
A process for recovering caprolactam from waste polycaprolactam comprising supplying an acid of the formula ##STR5## where n is 0 to 4 and the polycaprolactam to an autoclave in the amount of at least one mole of acid for every two moles of repeat units of the polymer, heating the mixture at a temperature of at least 150° C. and at autogenous pressure or greater for a time sufficient to depolymerize the polymer and form a mixture of caprolactam and a 6-alkylamidohexanoic acid and separating caprolactam from the mixture.
Claim 2
Dependent Claim
89 words
A process for recovering caprolactam from waste polycaprolactam comprising supplying an acid of the formula ##STR5## where n is 0 to 4 and the polycaprolactam to an autoclave in the amount of at least one mole of acid for every two moles of repeat units of the polymer, heating the mixture at a temperature of at least 150° C. and at autogenous pressure or greater for a time sufficient to depolymerize the polymer and form a mixture of caprolactam and a 6-alkylamidohexanoic acid and separating caprolactam from the mixture.
Claim 3
Dependent Claim
16 words
A process according to claim 1 wherein the waste polycaprolactam is the pile fiber of carpets.
Claim 4
Dependent Claim
92 words
A process for recovering adipic acid from waste polyhexamethylene adipamide comprising supplying an acid of the formula ##STR6## where n is 0 to 4 and the polyhexamethylene adipamide to an autoclave in the amount of at least two moles of acid for every mole of repeat units of the polymer, heating the mixture at a temperature of at least 150° C. and at autogenous pressure or greater for a time sufficient to depolymerize the polymer and form a mixture of adipic acid and N,N'-hexamethylene bisalkylamide and separating adipic acid from the mixture.
Claim 5
Dependent Claim
92 words
A process for recovering adipic acid from waste polyhexamethylene adipamide comprising supplying an acid of the formula ##STR6## where n is 0 to 4 and the polyhexamethylene adipamide to an autoclave in the amount of at least two moles of acid for every mole of repeat units of the polymer, heating the mixture at a temperature of at least 150° C. and at autogenous pressure or greater for a time sufficient to depolymerize the polymer and form a mixture of adipic acid and N,N'-hexamethylene bisalkylamide and separating adipic acid from the mixture.
Claim 6
Dependent Claim
17 words
A process according to claim 3 wherein the waste polyhexamethylene adipamide is the pile fiber of carpets.
Claim 7
Dependent Claim
122 words
A process for recovering caprolactam and adipic acid from waste containing both polycaprolactam and polyhexamethylene adipamide comprising supplying an acid of the formula ##STR7## where n is 0 to 4 and the mixture of the polymers to an autoclave in the amount of at least one mole of acid for every two moles of repeat units of polycaprolactam and at least two moles of acid for every mole of repeat units of polyhexamethylene adipamide and heating the mixture to a temperature of at least 150° C. and at autogenous pressure or greater for a time sufficient to depolymerize both polymers and form a mixture of caprolactam, 6-alkylamidohexanoic acid, adipic acid and N,N'-hexamethylene bisalkylamide and separating caprolactam and adipic acid from the mixture.
Claim 8
Dependent Claim
122 words
A process for recovering caprolactam and adipic acid from waste containing both polycaprolactam and polyhexamethylene adipamide comprising supplying an acid of the formula ##STR7## where n is 0 to 4 and the mixture of the polymers to an autoclave in the amount of at least one mole of acid for every two moles of repeat units of polycaprolactam and at least two moles of acid for every mole of repeat units of polyhexamethylene adipamide and heating the mixture to a temperature of at least 150° C. and at autogenous pressure or greater for a time sufficient to depolymerize both polymers and form a mixture of caprolactam, 6-alkylamidohexanoic acid, adipic acid and N,N'-hexamethylene bisalkylamide and separating caprolactam and adipic acid from the mixture.
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) | 1997-05-09 | 1997-11-08 | 1998-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-09 | 2001-11-08 | 2002-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-09 | 2005-11-08 | 2006-05-10 | $7700.00 | Window Closed / Lapsed |