US3937671A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of recovering constituents from polyester and cellulosic textile waste
Assignee: Textile Res Inst
•
Filing: 1974-11-18
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Granted: 1976-02-10
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Expires: 1994-11-18
Abstract
Abstract Textile wastes composed of blended polyester and cellulose fibers are subjected to the action of glacial acetic acid and acetic anhydride in the presence of a catalyst under conditions which serve to convert the cellulose component of the waste to cellulose acetate which is separated from the unreacted polyester component in the form of a solution adapted to be used in the manufacture of cellulose derivatives whereas the polyester is recovered in a form which may be garnetted to obtain a staple fiber for reuse.
Inventors
- 👤 Irving Gruntfest
- 👤 Rudolph Turner
- 👤 Ludwig Rebenfeld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:01
CPC Classifications
D; D06; D06Q; D06Q1/00; D06Q1/02; C; C08; C08J; C08J11/00; C08J11/04; Y; Y02; Y02P; Y02P20/00; Y02P20/141; Y02P20/143; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
58 words
A method of producing useful products from textile wastes containing blended polyester and cellulose fibers which comprises treating such wastes with an aqueous solution of glacial acetic acid and acetic anhydride under conditions which serve to acetylate the cellulose while leaving the polyester substantially unaffected and separating the unreacted polyester fiber from the cellulose acetate composition thereby produced.
Claim 2
Independent Claim
58 words
A method of producing useful products from textile wastes containing blended polyester and cellulose fibers which comprises treating such wastes with an aqueous solution of glacial acetic acid and acetic anhydride under conditions which serve to acetylate the cellulose while leaving the polyester substantially unaffected and separating the unreacted polyester fiber from the cellulose acetate composition thereby produced.
Claim 3
Dependent Claim
26 words
A method as defined in claim 1 wherein the textile waste is first treated with dilute acid to remove any additives carried by the waste treated.
Claim 4
Dependent Claim
26 words
A method as defined in claim 1 wherein the polyester fiber separated from the cellulose acetate produced is thereafter garnetted to form a loose fibrous product.
Claim 5
Dependent Claim
74 words
A method as defined in claim 1 wherein the textile waste is treated with dilute acid to activate the cellulose contained in the waste and is thereafter treated with glacial acetic acid and a catalyst followed by agitation in the presence of acetic anhydride, the unreacted polyester is separated from the resulting reaction mixture in which cellulose acetate is dissolved and water is added to the reaction mixture to precipitate the cellulose acetate therefrom.
Claim 6
Dependent Claim
50 words
A method as defined in claim 4 wherein the treatment of the textile waste with glacial acetic acid and acetic anhydride is carried out while agitating the mixture at ambient temperature until conversion of the cellulosic component to cellulose acetate is substantially complete and is dissolved in the reaction mixture.
Claim 7
Dependent Claim
25 words
A method as defined in claim 5 wherein the precipitated cellulose, acetate is separated from the reaction mixture and utilized to produced other cellulosic products.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-09 | 1979-08-11 | 1980-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-09 | 1983-08-11 | 1984-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-09 | 1987-08-11 | 1988-02-10 | $7700.00 | Window Closed / Lapsed |