US4118187A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fabric dye stripping, separation and recovery of polyester
Assignee: Monsanto Co
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Filing: 1976-12-09
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Granted: 1978-10-03
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Expires: 1996-12-09
Abstract
Abstract Polyester polymer is recovered from mixed collections of fibers in the form of fibers, filaments, yarns, or fabrics (including dyed or undyed fibers other than polyester fibers as well as dyed polyester fibers) and used in the production of new undyed fibers, by solvent stripping the dye from the polyester fibers without dissolving the fibers, and with additional solvent, selectively dissolving the polyester fibers in successive but functionally integrated steps; separating the dissolved fibers from an undissolved impurities and thereafter separating the residual dye-stripping solvent and the additional solvent from the polyester component without precipitiating the polyester component from solution by evaporating the solvent, preferably by atmospheric boiling and vacuum finishing of the molten solution.
Inventors
- 👤 Norman C. Sidebotham
- 👤 Paul D. Shoemaker
- 👤 Clarence W. Young, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:59
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; C08J11/08; B; B29; B29B; B29B17/00; B29B17/02; D; D06; D06P; D06P5/00; D06P5/13; D06P5/137; B29B2017/0213; B29B2017/0293; B29K; B29K2067/00; B29K2067/003; B29K2105/00; B29K2105/0005; B29K2105/0032; B29K2995/00; B29K2995/0018; B29K2995/002; B29L; B29L2031/00; B29L2031/726; C08J2367/00; C08J2367/02; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62; Y10; Y10S; Y10S264/00; Y10S264/911; Y10S264/913
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
174 words
A process for separation, recovery and reuse in production, of polyester polymer from a collection of materials comprising a first polyester component comprising dyed polyester fibers and a second component comprising materials other than polyester fibers, said process comprising: (1) stripping the dye from said dyed polyester fibers by contacting the collection with a dye-stripping solvent at a temperature below which the polyester dissolves and above which the crystalline lattice of the polyester fiber swells so as to release the dye; (2) removing the excess of the dye-containing dye-stripping solvent which is not absorbed by the collection; (3) contacting the residual dye-containing dye-stripping solvent-laden fibers with sufficient addition of a primary dissolution solvent which is not a solvent for the second component to dissolve the polyester component under selective dissolution conditions for the polyester component; (4) separating the dissolved polyester component from the undissolved second component; and (5) separating the residual dye-stripping solvent and the primary dissolution solvent from the polyester component by evaporation of the solvent without precipitating the polyester component from solution.
Claim 2
Dependent Claim
174 words
A process for separation, recovery and reuse in production, of polyester polymer from a collection of materials comprising a first polyester component comprising dyed polyester fibers and a second component comprising materials other than polyester fibers, said process comprising: (1) stripping the dye from said dyed polyester fibers by contacting the collection with a dye-stripping solvent at a temperature below which the polyester dissolves and above which the crystalline lattice of the polyester fiber swells so as to release the dye; (2) removing the excess of the dye-containing dye-stripping solvent which is not absorbed by the collection; (3) contacting the residual dye-containing dye-stripping solvent-laden fibers with sufficient addition of a primary dissolution solvent which is not a solvent for the second component to dissolve the polyester component under selective dissolution conditions for the polyester component; (4) separating the dissolved polyester component from the undissolved second component; and (5) separating the residual dye-stripping solvent and the primary dissolution solvent from the polyester component by evaporation of the solvent without precipitating the polyester component from solution.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the dye-stripping solvent is compatible with the primary dissolution solvent.
Claim 4
Dependent Claim
17 words
The process of claim 1 wherein the dye-stripping solvent is the same as the primary dissolution solvent.
Claim 5
Dependent Claim
49 words
The process of claim 1 wherein the primary dissolution solvent is selected from the group consisting of: para-chloroanisole, nitrobenzene, acetophenone, propylene carbonate, dimethyl sulfoxide, 2,6 xylenol, quinoline, naphthalene, meta-cresol, phenol, tetrahydronaphthalene, ortho-phenylphenol, para-phenylphenol, trifluoroacetic acid, ortho-chlorophenol, trichlorophenol, diphenyl, diphenyl ether, methyl naphthalene, benzophenone, diphenyl methane, para-dichlorobenzene, acenaphthene and phenanthrene.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the primary dissolution solvent is naphthalene.
Claim 7
Dependent Claim
37 words
The process of claim 1 wherein the primary dissolution solvent is naphthalene and the second component comprises fibers selected from the group consisting of cotton, rayon, silk, nylon-6, nylon-66, acrylic, acetate, wool, flax, glass and metallic fibers.
Claim 8
Dependent Claim
26 words
The process of claim 1 wherein evaporation is achieved by boiling at atmospheric pressure and then by applying a vacuum to complete removal of the solvents.
Claim 9
Dependent Claim
29 words
The process of claim 1 wherein dye-stripping solvent and the primary dissolution solvent is naphthalene, and the vacuum removal of solvent is conducted at a pressure below 150mm Hg.
Claim 10
Dependent Claim
12 words
The process of claim 1 wherein the second component comprises cotton fibers.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein the second component comprises polyamide fibers.
Claim 12
Dependent Claim
12 words
The process of claim 1 wherein the second component comprises wool fibers.
Claim 13
Dependent Claim
12 words
The process of claim 1 wherein the second component comprises acrylic fibers.
Claim 14
Dependent Claim
24 words
The process of claim 1 wherein the second component comprises a member of the group consisting of rayon fibers, acetate fibers and polypropylene fibers.
Claim 15
Dependent Claim
22 words
The process of claim 1 wherein the second component comprises a member of the group consisting of paper, metal scraps and glass.
Claim 16
Dependent Claim
33 words
The process of claim 1 wherein the primary dissolution solvent is benzophenone, and the second component comprises fibers selected from the group consisting of acrylic, cotton, wool, nylon 6, nylon 66 and rayon.
Claim 17
Dependent Claim
29 words
The process of claim 1 wherein the primary dissolution solvent is 1,1,1,3,3,3-hexafluoro-isopropanol and the second component comprises fibers selected from the group consisting of cotton, wool, polypropylene and rayon.
Claim 18
Dependent Claim
34 words
The process of claim 1 wherein the primary dissolution solvent is biphenyl, and the second component comprises fibers selected from the group consisting of acetate, acrylic, cotton, wool, nylon 6, nylon 66, and rayon.
Claim 19
Dependent Claim
34 words
The process of claim 1 wherein the primary dissolution solvent is acenaphthene and the second component comprises fibers selected from the group consisting of acetate, acrylic, cotton, wool, nylon 6, nylon 66, and rayon.
Claim 20
Dependent Claim
34 words
The process of claim 1 wherein the primary dissolution solvent is phenanthrene and the second component comprises fibers selected from the group consisting of acetate, acrylic, cotton, wool, nylon 6, nylon 66 and rayon.
Claim 21
Dependent Claim
34 words
The process of claim 1 wherein the primary dissolution solvent is diphenylmethane and the second component comprises fibers selected from the group consisting of cotton, nylon 6, nylon 66, rayon, wool, acetate and acrylic.
Claim 22
Dependent Claim
30 words
The process of claim 1 wherein the primary dissolution solvent is meta-cresol and the second component comprises fibers selected from the group consisting of acrylic, cotton, wool, polypropylene and rayon.
Claim 23
Dependent Claim
12 words
The process of claim 1 wherein the polyester polymer comprises polyethylene terephthalate.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1981-10-02 | 1982-04-03 | 1982-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-02 | 1986-04-03 | 1986-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-02 | 1990-04-03 | 1990-10-03 | $7700.00 | Window Closed / Lapsed |