Patent US985910A successfully refreshed from Google Patents.
Patent US5264640A successfully refreshed from Google Patents.
US5264640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Depolymerization method for resource recovery from polymeric wastes
Assignee: SP Reclamation Inc
•
Filing: 1992-04-06
•
Granted: 1993-11-23
•
Expires: 2012-04-06
Abstract
Abstract Scrap rubber chunks from used tires are processed and the monomeric chemicals from which the tire rubber was synthesized are recovered. Rubber chunks reduced to a finely divided size are exposed to gaseous ozone to break down the cross-linked structure of the rubber. Subsequent thermal depolymerization occurs in a reactor chamber. Finely divided silica is introduced within the reactor to prevent agglomeration of rubber particles and to enhance the maintenance of a uniform reactor temperature. Reduced pressure within the reactor permits rapid removal of monomer vapors. Once the monomer vapors are separated, silica and carbon residues are recovered separately for either recycle or disposal.
Inventors
- 👤 Gerald M. Platz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:48
CPC Classifications
C; C07; C07B; C07B63/00; C07B63/02; B; B29; B29B; B29B17/00; B29B17/04; B29B17/0404; B29B17/0408; C07C; C07C4/00; C07C4/22; B29L; B29L2030/00; C07C2527/00; C07C2527/20; C07C2527/232; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62; Y10; Y10S; Y10S241/00; Y10S241/37; Y10S264/00; Y10S264/911; Y10S264/912; Y10S425/00; Y10S425/044
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
104 words
A process for recovering a monomer from a vulcanized addition polymer feedstock formed from the monomer, comprising the steps of: (a) exposing the addition polymer feedstock to gaseous ozone under conditions sufficient to rupture chemical bonds formed during the vulcanization process of the addition polymer feedstock and thereby form one or more intermediate products; (b) mixing the intermediate products of step (a) with silica to form a mixture; (c) heating the mixture formed in step (b) to a temperature and for a time sufficient to depolymerize the addition polymer and form the monomer; and (d) removing the monomer following its formation from the mixture.
Claim 2
Dependent Claim
104 words
A process for recovering a monomer from a vulcanized addition polymer feedstock formed from the monomer, comprising the steps of: (a) exposing the addition polymer feedstock to gaseous ozone under conditions sufficient to rupture chemical bonds formed during the vulcanization process of the addition polymer feedstock and thereby form one or more intermediate products; (b) mixing the intermediate products of step (a) with silica to form a mixture; (c) heating the mixture formed in step (b) to a temperature and for a time sufficient to depolymerize the addition polymer and form the monomer; and (d) removing the monomer following its formation from the mixture.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the addition polymer feedstock is exposed to a mixture of gaseous ozone and air.
Claim 4
Dependent Claim
22 words
The process of claim 2 wherein the mixture of gaseous ozone and air comprises about 0.01 percent by weight of gaseous ozone.
Claim 5
Dependent Claim
26 words
The process of claim 1 wherein the addition polymer feedstock is exposed to gaseous ozone under conditions to rupture cross-linked bonds of the addition polymer feedstock.
Claim 6
Dependent Claim
22 words
The process of claim 1 wherein the addition polymer feedstock comprises particles ranging in size from about -6 to about +25 mesh.
Claim 7
Dependent Claim
26 words
The process of claim 1 wherein the mixture formed in step (b) is heated to a temperature of between about 250° C. and about 600° C.
Claim 8
Dependent Claim
26 words
The process of claim 1 wherein the mixture formed in step (b) is heated to a temperature of between about 450° C. and about 600° C.
Claim 9
Dependent Claim
29 words
The process of claim 1 wherein the mixture formed in step (b) is heated within a reaction zone having a pressure of from about 0.05 to about 0.25 atmospheres.
Claim 10
Dependent Claim
41 words
The process of claim 1 wherein the intermediate products of step (a) are mixed with silica and with a catalyst which is a salt selected from the group consisting of potassium carbonate, magnesium carbonate, calcium carbonate, sodium carbonate, and mixtures thereof.
Claim 11
Dependent Claim
37 words
The process of claim 1 wherein the intermediate products of step (a) are mixed with silica in a range from about a one to one ratio by volume to about a one to one-fourth ratio by volume.
Claim 12
Dependent Claim
17 words
The process of claim 1 wherein the addition polymer feedstock is rubber polymer recovered from used tires.
Claim 13
Dependent Claim
14 words
The process of claim 1 wherein the addition polymer feedstock is of polyolefin origin.
Claim 14
Dependent Claim
116 words
A process for the recovering more than one monomer from a vulcanized addition copolymer feedstock formed from multiple monomers, comprising the steps of: (a) exposing the addition copolymer feedstock to gaseous ozone under conditions sufficient to rupture chemical bonds formed during the vulcanization process of the addition copolymer feedstock and thereby form one or more intermediate products; (b) mixing the intermediate products of step (a) with silica to form a mixture; (c) consecutively heating within a series of close coupled reaction zones the mixture formed in step (b) to temperatures and for times sufficient to depolymerize the addition copolymer and form more than one monomer; and (d) removing each monomer following its formation from the mixture.
Claim 15
Dependent Claim
116 words
A process for the recovering more than one monomer from a vulcanized addition copolymer feedstock formed from multiple monomers, comprising the steps of: (a) exposing the addition copolymer feedstock to gaseous ozone under conditions sufficient to rupture chemical bonds formed during the vulcanization process of the addition copolymer feedstock and thereby form one or more intermediate products; (b) mixing the intermediate products of step (a) with silica to form a mixture; (c) consecutively heating within a series of close coupled reaction zones the mixture formed in step (b) to temperatures and for times sufficient to depolymerize the addition copolymer and form more than one monomer; and (d) removing each monomer following its formation from the mixture.
Claim 16
Dependent Claim
20 words
The process of claim 13 wherein the addition copolymer feedstock is exposed to a mixture of gaseous ozone and air.
Claim 17
Dependent Claim
22 words
The process of claim 14 wherein the mixture of gaseous ozone and air comprises about 0.01 percent by weight of gaseous ozone.
Claim 18
Dependent Claim
26 words
The process of claim 13 wherein the addition copolymer feedstock is exposed to gaseous ozone under conditions to rupture cross-linked bonds of the addition copolymer feedstock.
Claim 19
Dependent Claim
22 words
The process of claim 13 wherein the addition copolymer feedstock comprises particles ranging in size from about -6 to about +25 mesh.
Claim 20
Dependent Claim
25 words
The process of claim 13 wherein the mixture formed in step (b) is heated to temperatures of between about 250° C. and about 600° C.
Claim 21
Dependent Claim
25 words
The process of claim 13 wherein the mixture formed in step (b) is heated to temperatures of between about 450° C. and about 600° C.
Claim 22
Dependent Claim
27 words
The process of claim 13 wherein the mixture formed in step (b) is heated within reaction zones having pressures of from about 0.05 to about 0.25 atmospheres.
Claim 23
Dependent Claim
41 words
The process of claim 13 wherein the intermediate products of step (a) are mixed with silica and with a catalyst which is a salt selected from the group consisting of potassium carbonate, magnesium carbonate, calcium carbonate, sodium carbonate, and mixtures thereof.
Claim 24
Dependent Claim
37 words
The process of claim 13 wherein the intermediate products of step (a) are mixed with silica in a range from about a one to one ratio by volume to about a one to one-fourth ratio by volume.
Claim 25
Dependent Claim
17 words
The process of claim 13 wherein the addition copolymer feedstock is rubber copolymer recovered from used tires.
Claim 26
Dependent Claim
14 words
The process of claim 13 wherein the addition copolymer feedstock is of polyolefin origin.
References Cited (Backward Citations)
US4029550A
Cited
US4098649A
Cited
US4051212A
Cited
US4025990A
Cited
US4240587A
Cited
US4250158A
Cited
US4458095A
Cited
US4515659A
Cited
US4746406A
Cited
US4740270A
Cited
US5084141A
Cited
US4863106A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-22 | 1997-05-24 | 1997-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-22 | 2001-05-24 | 2001-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-22 | 2005-05-24 | 2005-11-23 | $7700.00 | Window Closed / Lapsed |