US5151452A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of polycarbonate and polyester carbonate waste
Assignee: Bayer AG
•
Filing: 1991-09-17
•
Granted: 1992-09-29
•
Expires: 2011-09-17
Abstract
Abstract A process is disclosed for the purification of lacquer-and optionally dye and metal- containing waste of thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyester carbonates. The waste which result upon the production of moldings, such as audio compact discs, lenses for spectacles or head-lamp reflectors is processed in accordance with the invention to yield useful resin suitable for reprocessing as a molding resin. In accordance with the process, the waste is first size-reduced and then heated with acid to the reflux temperature while stirring. After a water wash there is followed a drying step. In accordance with the process, in instances where the waste does not originally contain metal, the metal in powder form is added before the acid treatment.
Inventors
- 👤 Gerhard Fennhoff
- 👤 Wolfgang Jakob
- 👤 Manfred Ehlert
- 👤 Dieter Freitag
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:07
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; B; B29; B29B; B29B13/00; B29B13/10; B29B17/00; B29B17/02; B29K; B29K2067/00; B29K2069/00; B29K2705/00; B29L; B29L2009/00; B29L2009/005; B29L2011/00; B29L2011/0016; B29L2017/00; B29L2017/001; B29L2017/003; B29L2017/005; C08J2369/00; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
130 words
A process for the purification of resinous waste of at least one polycondensate selected from the group consisting of thermoplastic aromatic polycarbonates and thermoplastic aromatic polyester carbonates which waste contains lacquers and optionally dyes and/or metal contaminants comprising in sequence (i) size-reducing the waste to fragments having an average particle size of 0.1 to 5.0 cm, (ii) refluxing said fragments with an aqueous mineral acid while stirring to effect removing of said lacquer and/or dye from said polycondensate, (iii) water-washing while stirring until neutral and until all the lacquer and/or dye components removed from the polycondensate have been rinsed out, (iv) filtering the remaining liquids and drying the resultant fragments, with the proviso where said waste contains no metal contaminants, added metal is introduced to the process before said (ii).
Claim 2
Dependent Claim
130 words
A process for the purification of resinous waste of at least one polycondensate selected from the group consisting of thermoplastic aromatic polycarbonates and thermoplastic aromatic polyester carbonates which waste contains lacquers and optionally dyes and/or metal contaminants comprising in sequence (i) size-reducing the waste to fragments having an average particle size of 0.1 to 5.0 cm, (ii) refluxing said fragments with an aqueous mineral acid while stirring to effect removing of said lacquer and/or dye from said polycondensate, (iii) water-washing while stirring until neutral and until all the lacquer and/or dye components removed from the polycondensate have been rinsed out, (iv) filtering the remaining liquids and drying the resultant fragments, with the proviso where said waste contains no metal contaminants, added metal is introduced to the process before said (ii).
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said added metal is a metal salts.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein said particle size is about 0.5 to 1.5 cm.
Claim 5
Dependent Claim
23 words
The process of claim 1 wherein any lacquer residue still adhering to the fragments are removed by air separation subsequent to said (iv).
Claim 6
Dependent Claim
24 words
The process of claim 1 wherein said metal is at least one member selected from the group consisting of aluminum, iron, zinc and tin.
Claim 7
Dependent Claim
28 words
The process of claim 1 wherein said acid is at least one member selected from the group consisting of hydrohalic acid, perchloric acid, phosphoric acid and sulfuric acid.
Claim 8
Dependent Claim
16 words
The process of claim 1 wherein said added metal is added in combination with said acid.
Claim 9
Dependent Claim
19 words
The process of claim 7 wherein said combination is a solution of aluminum (III) halides in aqueous hydrohalic acid.
Claim 10
Dependent Claim
18 words
The process of claim 7 wherein said combination is a solution of aluminum powder in aqueous hydrohalic acid.
Claim 11
Dependent Claim
28 words
The process of claim 1 wherein said lacquers are based on a member selected from the group consisting of polyacrylonitrile, polyacrylate, polymethacrylate, polyvinyl chloride, polysiloxane and melamine resin.
Claim 12
Dependent Claim
14 words
A thermoplastic molding composition comprising the product prepared by the process of claim 1.
References Cited (Backward Citations)
US3070553A
Cited
US3098046A
Cited
DE1422813A1
Cited
US3565852A
Cited
US3652466A
Cited
US4143001A
Cited
DE2814908A1
Cited
US4212774A
Cited
US4118346A
Cited
US4602046A
Cited
DE3511711A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-29 | 1996-03-30 | 1996-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-29 | 2000-03-30 | 2000-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-29 | 2004-03-30 | 2004-09-29 | $7700.00 | Window Closed / Lapsed |