Patent US3928263A successfully refreshed from Google Patents.
US3928263A
Expired / Lapsed
US
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Process for producing polyolefin powders with grinding aids and powder composition of grinding aids and polyolefins
Assignee: Eastman Kodak Co
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Filing: 1974-03-29
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Granted: 1975-12-23
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Expires: 1994-03-29
Abstract
Abstract A powder composition of a crystalline polyolefin material and 5 to 35 percent by weight of a grinding aid that is a dissimilar and incompatible polymeric material with respect to the polyolefin, the polymeric material having a softening point below 450*F. and a greater grindability than the polyolefin, and process for preparing polyolefin powder by introducing a grinding aid into a crystalline polyolefin, as by melt compounding, extruding into pellets and then grinding the polyolefins in the presence of the grinding aid. The product yield in one pass through a grinder is increased significantly over that of a polyolefin that has no such grinding aid, as disclosed herein.
Inventors
- 👤 Peter M Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:30
CPC Classifications
B; B02; B02C; B02C23/00; B02C23/06; B02C19/00; B02C19/18; Y; Y10; Y10S; Y10S241/00; Y10S241/14
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
64 words
A PROCESS FOR PREPARING POLYOLEFIN POWDERS WHICH COMPRISES INTRODUCING A GRINDING AID INTO A CRYSTALLINE POLYOLEFIN BY MELT COMPOUNDING THE GRINDING AID TOGETHER WITH THE CRYSTALLINE POLYOLEFIN, EXTRUDING INTO PELLETED FORM AND GRINDING THE PELLETS TO FORM SAID POLYOLEFIN POWDERS, THE INTRODUCED GRINDING AID BEING A DISSIMILAR AND INCOMPATINLE POLYMERIC MAMATERIAL HAVING A SOFTENING POINT BELOW 450*F. AND A GREATER GRINDABILITY THAN SAID POLYOLEFIN.
Claim 2
Dependent Claim
64 words
A PROCESS FOR PREPARING POLYOLEFIN POWDERS WHICH COMPRISES INTRODUCING A GRINDING AID INTO A CRYSTALLINE POLYOLEFIN BY MELT COMPOUNDING THE GRINDING AID TOGETHER WITH THE CRYSTALLINE POLYOLEFIN, EXTRUDING INTO PELLETED FORM AND GRINDING THE PELLETS TO FORM SAID POLYOLEFIN POWDERS, THE INTRODUCED GRINDING AID BEING A DISSIMILAR AND INCOMPATINLE POLYMERIC MAMATERIAL HAVING A SOFTENING POINT BELOW 450*F. AND A GREATER GRINDABILITY THAN SAID POLYOLEFIN.
Claim 3
Dependent Claim
18 words
A process for preparing polyolefin powders as defined in claim 1, said pellets being ground under cryogenic conditions.
Claim 4
Dependent Claim
28 words
A process for preparing polyolefin powders according to claim 1 wherein the polyolefin is a member selected from the group consisting of crystalline polyolefins or carboxylated crystalline polyolefins.
Claim 5
Dependent Claim
26 words
A process for preparing polyolefin powders according to claim 1 wherein the introduced grinding aid is a member selected from the group consisting of linear polyesters.
Claim 6
Dependent Claim
27 words
A process for preparing polyolefin powders according to claim 1 wherein the introduced grinding aid is a member selected from the group consisting of cellulose acetate esters.
Claim 7
Dependent Claim
39 words
A process for preparing polyolefin powders according to claim 5 wherein the introduced grinding aid is cellulose acetate butyrate having 25 to 55 percent butyryl and 20 to 1 percent acetyl and a viscosity from 0.01 to 10 seconds.
Claim 8
Dependent Claim
37 words
A process for preparing polyolefin powders according to claim 5 wherein the introduced grinding aid is cellulose acetate propionate having 39-47 percent propionyl and 5 to 1 percent acetyl and a viscosity from 0.01 to 10 seconds.
Claim 9
Dependent Claim
18 words
A process for preparing polyolefin powders according to claim 3 wherein the carboxylated crystalline polyolefin is poly(propylenegraft-acrylic acid).
Claim 10
Dependent Claim
57 words
A powder composition comprising a crystalline polyolefin and 5 to 35 percent by weight of a grinding aid having been introduced in the crystalline polyolefin by melt compounding, said grinding aid being a dissimilar and incompatible, polymeric material with respect to said polyolefin and having a softening point below 450*F. and a greater grindability than said polyolefin.
Claim 11
Dependent Claim
57 words
A powder composition comprising a crystalline polyolefin and 5 to 35 percent by weight of a grinding aid having been introduced in the crystalline polyolefin by melt compounding, said grinding aid being a dissimilar and incompatible, polymeric material with respect to said polyolefin and having a softening point below 450*F. and a greater grindability than said polyolefin.
Claim 12
Dependent Claim
21 words
A powder composition as defined in claim 9, the composition comprising 10 to 25 percent by weight of said grinding aid.
Claim 13
Dependent Claim
25 words
A powder composition as defined in claim 9, the polyolefin being a member selected from the group consisting of crystalline polyolefins or carboxylated crystalline polyolefins.
Claim 14
Dependent Claim
23 words
A powder composition as defined in claim 9 wherein said grinding aid is a member selected from the group consisting of linear polyesters.
Claim 15
Dependent Claim
23 words
A powder composition as defined in claim 9 wherein said grinding aid is a member selected from the group of cellulose acetate esters.
Claim 16
Dependent Claim
36 words
A powder composition as defined in claim 13 wherein said grinding aid is cellulose acetate butyrate having 25 to 55 percent butyryl and 20 to 1 percent acetyl, and a viscosity from 0.01 to 10 seconds.
Claim 17
Dependent Claim
34 words
A powder composition as defined in claim 13 wherein said grinding aid is cellulose acetate propionate having 39-47 percent propionyl and 5 to 1 percent acetyl, and a viscosity from 0.01 to 10 seconds.
Claim 18
Dependent Claim
16 words
A powder composition as defined in claim 11 wherein said carboxylated crystalline polyolefin is poly(propylene-graft-acrylic acid).
Claim 19
Dependent Claim
36 words
A powder composition as defined in claim 13 wherein said grinding aid is cellulose acetate butyrate having 25 to 55 percent butyryl and 20 to 1 percent acetyl, and a viscosity from 0.01 to 10 seconds.
Claim 20
Dependent Claim
34 words
A powder composition as defined in claim 13 wherein said grinding aid is cellulose acetate propionate having 39-47 percent propionyl and 5 to 1 percent acetyl, and a viscosity from 0.01 to 10 seconds.
Claim 21
Dependent Claim
15 words
A powder composition as defined in claim 9 wherein said grinding aid is substantially amorphous.
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) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |