US4132633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for separating mixture of plastics
Assignee: Mitsui Kinzoku Co Ltd
•
Filing: 1975-03-14
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Granted: 1979-01-02
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Expires: 1995-03-14
Abstract
Abstract A method for separating a mixture of plastics of at least two components selected from the group consisting of polyethylene, polypropylene and a polystyrene, which comprises placing the mixture of plastics in a separation cell containing an aqueous liquid medium containing at least one wetting agent, and introducing gas bubbles into the cell thereby to cause the gas bubbles to selectively adhere to the surface of the polypropylene and/or polyethylene and float the polypropylene and/or polyethylene when the mixture of plastics comprises a polystyrene and polypropylene and/or polyethylene or to selectively adhere to the surface of the polypropylene and float the polypropylene when the mixture of plastics comprises polypropylene and polyethylene with the polypropylene and/or the polyethylene being recovered as a float and the polystyrene being recovered as a residue when the mixture of plastics comprises a polystyrene and polypropylene and/or polyethylene, and with the polypropylene being recovered as a float and the polyethylene being recovered as a residue when the mixture of plastics comprises polypropylene and polyethylene.
Inventors
- 👤 Kozo Saitoh
- 👤 Sumio Izumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:53
CPC Classifications
B; B03; B03D; B03D1/00; B03D1/02; B29; B29B; B29B17/00; B29B17/02; B03D1/14; B03D1/1431; B29B2017/0203; B29B2017/0213; B29B2017/0217; B29B2017/0248; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/10; B29K2023/12; B29K2025/00; B29K2033/00; B29K2033/18; B29K2055/00; B29K2055/02; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
118 words
A method for separating polyethylene and/or polypropylene from a mixture of plastics consisting of a polystyrene and at least one of polyethylene and polypropylene, which comprises dispersing a mixture of said plastics in an aqueous liquid medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polystyrene more hydrophilic than that of the polypropylene and/or polyethylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polypropylene and/or polyethylene and float the polypropylene and/or polyethylene; and recovering the polyethylene and/or polypropylene as a float and leaving the polystyrene as a residue.
Claim 2
Independent Claim
118 words
A method for separating polyethylene and/or polypropylene from a mixture of plastics consisting of a polystyrene and at least one of polyethylene and polypropylene, which comprises dispersing a mixture of said plastics in an aqueous liquid medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polystyrene more hydrophilic than that of the polypropylene and/or polyethylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polypropylene and/or polyethylene and float the polypropylene and/or polyethylene; and recovering the polyethylene and/or polypropylene as a float and leaving the polystyrene as a residue.
Claim 3
Dependent Claim
17 words
The method of claim 1, wherein said polystyrene is polystyrene, an acrylonitrile-butadiene-styrene resin or an acrylonitrile-styrene resin.
Claim 4
Dependent Claim
35 words
The method of claim 1, wherein the proportion of said mixture in said aqueous liquid medium ranges from about 1 to 10 parts by weight per 100 parts by weight of said aqueous liquid medium.
Claim 5
Dependent Claim
25 words
The method of claim 1, wherein said wetting agent is sodium lignin sulfonate, calcium lignin sulfonate, tannic acid, a quebracho extract, gelatin, glue or saponin.
Claim 6
Dependent Claim
30 words
The method of claim 4, wherein the proportion of said wetting agent in said aqueous liquid medium ranges from about 1 to 500g per ton of said mixture of plastics.
Claim 7
Dependent Claim
21 words
The method of claim 1, wherein said separation is carried out at a temperature of from about 20° to 60° C.
Claim 8
Dependent Claim
15 words
The method of claim 1, wherein said aqueous liquid medium is water or salt water.
Claim 9
Dependent Claim
27 words
The method of claim 7, wherein said salt water is sea water, brine, bittern-containing water or an aqueous solution of a halide, a sulfate or a bicarbonate.
Claim 10
Dependent Claim
109 words
The method of claim 1, wherein said mixture of plastics consists of a mixture of polyethylene, polypropylene and a polystyrene and wherein said method includes dispersing the polyethylene and the polypropylene recovered as a float in an aqueous liquid medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polyethylene more hydrophilic than that of the polypropylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polypropylene and recovering the polypropylene as a float and leaving the polyethylene as a residue.
Claim 11
Independent Claim
101 words
A method of separating polypropylene from a mixture of plastics consisting of polypropylene and a polystyrene, which comprises dispersing a mixture of said plastics in an aqueous medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polystyrene more hydrophilic than that of the polypropylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polypropylene and float the polypropylene, and recovering the polypropylene as a float and leaving the polystyrene as a residue.
Claim 12
Independent Claim
101 words
A method of separating polypropylene from a mixture of plastics consisting of polypropylene and a polystyrene, which comprises dispersing a mixture of said plastics in an aqueous medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polystyrene more hydrophilic than that of the polypropylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polypropylene and float the polypropylene, and recovering the polypropylene as a float and leaving the polystyrene as a residue.
Claim 13
Dependent Claim
25 words
The method of claim 10, wherein said wetting agent is sodium lignin sulfonate, calcium lignin sulfonate, tannic acid, a quebracho extract, gelatin, glue or saponin.
Claim 14
Dependent Claim
31 words
The method of claim 11, wherein the proportion of said wetting agent in said aqueous liquid medium ranges from about 1 to 500 g per ton of said mixture of plastics.
Claim 15
Independent Claim
101 words
A method of separating polyethylene from a mixture of plastics consisting of polyethylene and a polystyrene, which comprises dispersing a mixture of said plastics in an aqueous medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polystyrene more hydrophilic than that of the polyethylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polyethylene and float the polyethylene; and recovering the polyethylene as a float and leaving the polystyrene as a residue.
Claim 16
Independent Claim
101 words
A method of separating polyethylene from a mixture of plastics consisting of polyethylene and a polystyrene, which comprises dispersing a mixture of said plastics in an aqueous medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polystyrene more hydrophilic than that of the polyethylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polyethylene and float the polyethylene; and recovering the polyethylene as a float and leaving the polystyrene as a residue.
Claim 17
Dependent Claim
25 words
The method of claim 13, wherein said wetting agent is sodium lignin sulfonate, calcium lignin sulfonate, tannic acid, a quebracho extract, gelatin, glue or saponin.
Claim 18
Dependent Claim
31 words
The method of claim 14, wherein the proportion of said wetting agent in said aqueous liquid medium ranges from about 1 to 500 g per ton of said mixture of plastics.
Claim 19
Independent Claim
100 words
A method of separating polypropylene from a mixture of plastics consisting of polypropylene and polyethylene, which comprises dispersing a mixture of said plastics in an aqueous medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polyethylene more hydrophilic than that of the polypropylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polypropylene and float the polypropylene; and recovering the polypropylene as a float and leaving the polyethylene as a residue.
Claim 20
Independent Claim
100 words
A method of separating polypropylene from a mixture of plastics consisting of polypropylene and polyethylene, which comprises dispersing a mixture of said plastics in an aqueous medium along with at least one wetting agent in an amount sufficient and continuing the dispersing for a time sufficient to make the surface of the polyethylene more hydrophilic than that of the polypropylene; discontinuing the dispersing while introducing gas bubbles into the mixture, whereby the gas bubbles selectively adhere to the surface of the polypropylene and float the polypropylene; and recovering the polypropylene as a float and leaving the polyethylene as a residue.
Claim 21
Dependent Claim
25 words
The method of claim 16, wherein said wetting agent is sodium lignin sulfonate, calcium lignin sulfonate, tannic acid, a quebracho extract, gelatin, glue or saponin.
Claim 22
Dependent Claim
31 words
The method of claim 17, wherein the proportion of said wetting agent in said aqueous liquid medium ranges from about 1 to 500 g per ton of said mixture of plastics.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-01 | 1982-07-03 | 1983-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-01 | 1986-07-03 | 1987-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-01 | 1990-07-03 | 1991-01-02 | $7700.00 | Window Closed / Lapsed |