US5214072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of polycarbonate, polyester carbonate or polyester waste
Assignee: Bayer AG
•
Filing: 1992-10-08
•
Granted: 1993-05-25
•
Expires: 2012-10-08
Abstract
Abstract A process for the purification of waste of thermoplastic resins containing at least one member selected from among aromatic polycarbonates, aromatic polyester carbonates and aromatic polyesters and at least one of aluminum, lacquers and dyes which waste accumulates in the production of optical moldings is disclosed. The process which entails size reduction of the waste, chemical wash and filtering steps yields purified resins suitable for thermoplastic processing.
Inventors
- 👤 Gerhard Fennhoff
- 👤 Wolfgang Jakob
- 👤 Manfred Ehlert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:21
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; B; B29; B29B; B29B17/00; B29B17/02; B29B2017/0203; B29B2017/0213; B29B2017/0286; B29B2017/0289; B29B2017/0293; B29B2017/0296; B29K; B29K2027/00; B29K2027/06; B29K2033/00; B29K2033/04; B29K2067/00; B29K2069/00; B29K2105/00; B29K2105/06; B29K2105/065; B29K2705/00; B29K2705/02; B29L; B29L2009/00; B29L2009/005; B29L2017/00; B29L2017/001; B29L2017/003; B29L2017/005; Y; Y02; Y02P; Y02P20/00; Y02P20/141; Y02P20/143; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
152 words
A process for the purification of waste thermoplastic aromatic resin comprising in sequence the steps of (i) size-reducing said waste to obtain fragments having a mean diameter of 0.1 to 5 cm, (ii) stirring said fragments with a base for 20 to 300 minutes at temperatures of 10° to 100° C., (iii) removing said base to obtain second fragments, (iv) washing said second fragments with a dilute acid to obtain acid-washed fragments, (v) washing said acid-washed fragments with water to obtain electrolyte-free fragments, (vi) washing said electrolyte-free fragments with water while gently stirring to effect separation of all contaminants to obtain pure fragments, (vii) rinsing said pure fragments with water and filtering to obtain rinsed-fragments, (viii) drying said rinsed fragments, said waste thermoplastic aromatic resin containing (a) at least one of polycarbonate, polyester or polyestercarbonate and (b) at least one contaminant selected from the group consisting of aluminum, lacquers, pigments and dyes.
Claim 2
Dependent Claim
152 words
A process for the purification of waste thermoplastic aromatic resin comprising in sequence the steps of (i) size-reducing said waste to obtain fragments having a mean diameter of 0.1 to 5 cm, (ii) stirring said fragments with a base for 20 to 300 minutes at temperatures of 10° to 100° C., (iii) removing said base to obtain second fragments, (iv) washing said second fragments with a dilute acid to obtain acid-washed fragments, (v) washing said acid-washed fragments with water to obtain electrolyte-free fragments, (vi) washing said electrolyte-free fragments with water while gently stirring to effect separation of all contaminants to obtain pure fragments, (vii) rinsing said pure fragments with water and filtering to obtain rinsed-fragments, (viii) drying said rinsed fragments, said waste thermoplastic aromatic resin containing (a) at least one of polycarbonate, polyester or polyestercarbonate and (b) at least one contaminant selected from the group consisting of aluminum, lacquers, pigments and dyes.
References Cited (Backward Citations)
US5151452A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-24 | 1996-11-23 | 1997-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-24 | 2000-11-23 | 2001-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-24 | 2004-11-23 | 2005-05-25 | $7700.00 | Window Closed / Lapsed |