Patent US165561A successfully refreshed from Google Patents.
Patent US4543364A successfully refreshed from Google Patents.
US4543364A
Expired / Lapsed
US
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Recovery of polyethylene terephthalate (PET)
Assignee: Dow Chemical Co
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Filing: 1984-12-13
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Granted: 1985-09-24
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Expires: 2004-12-13
Abstract
Abstract A method of reclaiming clear PET resin from bottles and other containers is disclosed. PET resin contaminated with a hot melt type polyethylene copolymer based glue is treated with a chlorinated solvent and optionally subjected to azeotropic drying.
Inventors
- 👤 Robert J. Nankee
- 👤 Thomas A. Vivian
- 👤 Kenneth O. Groves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:54
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; C08J11/08; C08J2367/00; C08J2367/02; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
49 words
A process of recovering clear polyethylene terephthalate (PET) resin in particulate form substantially free from contaminating glue and paper which comprises: contacting glue- and paper-contaminated PET particles with a sufficient quantity of a chlorinated solvent to dissolve the glue from the PET and separating the solvent from the particles.
Claim 2
Dependent Claim
49 words
A process of recovering clear polyethylene terephthalate (PET) resin in particulate form substantially free from contaminating glue and paper which comprises: contacting glue- and paper-contaminated PET particles with a sufficient quantity of a chlorinated solvent to dissolve the glue from the PET and separating the solvent from the particles.
Claim 3
Dependent Claim
24 words
The process of claim 1 including the additional step of azeotropic drying of the PET resin following treatment with the chlorinated solvent employing water.
Claim 4
Dependent Claim
21 words
The process of claim 2 including the step of recovering the solvent from the azeotrope formed in the azeotropic drying step.
Claim 5
Dependent Claim
21 words
The process of claim 3 including the step of returning the recovered solvent to the glue removing step of the process.
Claim 6
Dependent Claim
27 words
The process of claim 1 wherein the solvent is selected from the group consisting of chloroform, CCl 4 , 1,1,1-trichloroethane, methylene chloride, perchloroethylene, trichloroethylene or mixtures thereof.
Claim 7
Dependent Claim
20 words
The process of claim 5 wherein the contaminated PET is first washed with water prior to contact with the solvent.
Claim 8
Dependent Claim
28 words
The process of claim 5 wherein the PET is contacted with the solvent in liquid form maintained at a temperature up to the boiling point of the solvent.
Claim 9
Dependent Claim
15 words
The process of claim 5 wherein the PET is contacted with vapors of the solvent.
Claim 10
Dependent Claim
113 words
A process of removing paper and glue from scrap particulate polyethylene terephthalate (PET) resin which comprises: (a) rinsing the scrap PET with water to thereby form a float of paper and a sink of PET containing less paper and glue; (b) separating the PET from the water and float; (c) contacting the recovered PET from step (b) with a sufficient amount of a chlorinated solvent maintained at a temperature up to the boiling point of the solvent to dissolve substantially all glue in the PET and floating additional paper; (d) separating the PET from the solvent and floated paper; and (e) removing solvent remaining on the particulate PET by azeotropic distillation employing water.
Claim 11
Dependent Claim
113 words
A process of removing paper and glue from scrap particulate polyethylene terephthalate (PET) resin which comprises: (a) rinsing the scrap PET with water to thereby form a float of paper and a sink of PET containing less paper and glue; (b) separating the PET from the water and float; (c) contacting the recovered PET from step (b) with a sufficient amount of a chlorinated solvent maintained at a temperature up to the boiling point of the solvent to dissolve substantially all glue in the PET and floating additional paper; (d) separating the PET from the solvent and floated paper; and (e) removing solvent remaining on the particulate PET by azeotropic distillation employing water.
Claim 12
Dependent Claim
27 words
The process of claim 9 wherein the solvent is selected from the group consisting of chloroform, CCl 4 , methylene chloride, 1,1,1-trichloroethane, trichloroethylene, perchloroethylene or mixture thereof.
Claim 13
Dependent Claim
24 words
The process of claim 1 wherein as an additional step, separating the solvent from the azeotropic mixture and reusing the solvent in the process.
Claim 14
Dependent Claim
24 words
The process of claim 10 including as an additional step, separating the solvent from the azeotropic mixture and reusing the solvent in the process.
References Cited (Backward Citations)
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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) | 1988-09-23 | 1989-03-25 | 1989-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-23 | 1993-03-25 | 1993-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-23 | 1997-03-25 | 1997-09-24 | $7700.00 | Window Closed / Lapsed |