US3627733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for particularizing thermoplastic polyesters
Assignee: Asahi Kasei Corp
•
Filing: 1967-12-05
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Granted: 1971-12-14
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Expires: 1987-12-05
Abstract
Abstract A method for particulating a thermoplastic polyester which has a solubility parameter in water of at least 10, and which is insoluble in water at the boiling point of water at normal pressure, such as polyethylene terephthalate, said method comprising heating a mass of the polyester in an autoclave solely in the presence of water up to the temperature that is lower than the melting point of the polyester to dissolve said thermoplastic polyester in the water and cooling or spraying through a nozzle the contents of the autoclave to produce a powder of the polyester.
Inventors
- 👤 Akira Ioka
- 👤 Tsuneyuki Kato
- 👤 Yutaka Toyoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:18
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/122
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
14 words
A method as claimed in claim 1 wherein said thermoplastic polyester is polyethylene terephthalate.
Claim 2
Independent Claim
116 words
A method for particulating a thermoplastic polyester, said method comprising heating a thermoplastic polyester mass which is insoluble in water at temperatures up to the boiling poinT of water at normal pressure in an autoclave solely in the presence of water in an amount at least equal in weight to that of said thermoplastic polyester the thermoplastic polyester having a solubility parameter in water of at least 10, and the temperature in the autoclave being less than the melting point of the thermoplastic polyester to dissolve said thermoplastic polyester in the water and then spraying the contents of the autoclave under pressure through a nozzle while being heated to obtain the thermoplastic polyester in powder state.
Claim 3
Dependent Claim
14 words
A method as claimed in claim 3 wherein said thermoplastic polyester is polyethylene terephthalate.
Claim 4
Independent Claim
113 words
A method for particulating polyethylene terephthalate, said method comprising heating a mass of polyethylene terephthalate which is insoluble in water at temperatures up to the boiling point of water at normal pressure and has a solubility parameter in water of at least 10 in an autoclave solely in the presence of water in an amount at least equal in weight to that of said polyethylene terephthalate, at a temperature of at least 170* C. and less than the melting point of the polyethylene terephthalate to dissolve same in the water, cooling the solution to precipitate the polyethylene terephthalate in powder state, and filtering the solution to obtain the polyethylene terephthalate in powder state.
Claim 5
Independent Claim
114 words
A method for particulating polyethylene terephthalate, said method comprising heating a mass of polyethylene terephthalate which is insoluble in water at temperatures up to the boiling point of water at normal pressure and has a solubility parameter in water of at least 10 in an autoclave solely in the presence of water in an amount at least equal in weight to that of said polyethylene terephthalate, at a temperature of at least 170* C. and less than the melting point of the polyethylene terephthalate to dissolve same in the water, and then spraying the contents of the autoclave under pressure through a nozzle while being heated to obtain the polyethylene terephthalate in powder state.
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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) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |