US4183887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing free flowing particles of elastomeric material
Assignee: DSM Copolymer Inc
•
Filing: 1977-04-28
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Granted: 1980-01-15
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Expires: 1997-04-28
Abstract
Abstract Elastomeric particles which are rendered free flowing by treatment with the combination of a finely divided partitioning agent and a fibrilatable polymer which has been fibrilated to form a network on the surface of the elastomeric material with retention of the partitioning agent thereby.
Inventors
- 👤 Rudolph F. Karg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:22
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/124; C08J2321/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
104 words
The method of producing free flowing elastomeric particles comprising mixing in the dry state the particles of elastomeric material with a fibrillating synthetic resinous material and a finely divided partitioning agent, moving the particles of elastomeric material and the fibrillating synthetic resin relative to each other in a dry mixing operation at elevated temperature and in the presence of the partitioning agent whereby the synthetic resinous material fibrillates to form a porous network on the surface of the particles of elastomeric material in which the partitioning agent becomes entrapped to be retained in position to maintain separation for free flow of the elastomeric particles.
Claim 2
Independent Claim
104 words
The method of producing free flowing elastomeric particles comprising mixing in the dry state the particles of elastomeric material with a fibrillating synthetic resinous material and a finely divided partitioning agent, moving the particles of elastomeric material and the fibrillating synthetic resin relative to each other in a dry mixing operation at elevated temperature and in the presence of the partitioning agent whereby the synthetic resinous material fibrillates to form a porous network on the surface of the particles of elastomeric material in which the partitioning agent becomes entrapped to be retained in position to maintain separation for free flow of the elastomeric particles.
Claim 3
Dependent Claim
43 words
The method as claimed in claim 1, in which the fibrilating synthetic resinous material is a polytetrafluoroethylene polymer and in which fibrilation is achieved by working with movement of the particles while at a temperature within the range of 100° to 125° C.
Claim 4
Dependent Claim
17 words
The method as claimed in claim 1, in which the partitioning agent is a synthetic calcium silicate.
Claim 5
Dependent Claim
30 words
The method as claimed in claim 1, in which the partitioning agent is present in an amount within the range of 0.5 to 5.0% by weight of the elastomeric material.
Claim 6
Dependent Claim
31 words
The method as claimed in claim 1, in which the fibrilating resinous material is present in an amount within the range of 0.01 to 1.0% by weight of the elastomeric material.
Claim 7
Dependent Claim
26 words
The method as claimed in claim 2, in which the polytetrafluoroethylene polymer is present in an amount of about 0.05% by weight of the elastomeric material.
Claim 8
Dependent Claim
26 words
The method as claimed in claim 1, in which working is carried out by movement of the material in a fluidized state while at elevated temperature.
Claim 9
Dependent Claim
34 words
The method as claimed in claim 1, in which the partitioning agent is added after the synthetic resinous material has been fibrilated to form a porous network on the surface of the elastomeric particles.
Claim 10
Dependent Claim
29 words
The method as claimed in claim 1, in which the fibrilating synthetic resinous material is selected from the group consisting of polyethylene, polypropylene and copolymers thereof or mixtures thereof.
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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) | 1983-01-14 | 1983-07-16 | 1984-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-14 | 1987-07-16 | 1988-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-14 | 1991-07-16 | 1992-01-15 | $7700.00 | Window Closed / Lapsed |