Claims
- 1. A composition which comprises
- (a) a continuous matrix comprising a first organic polymer, and
- (b) a first particulate conductive filler (i) which is distributed in the matrix and maintains its identity therein; (ii) each particle of which comprises a crosslinked second organic polymer, and a second particulate conductive filler which is distributed in the second polymer, and (iii) which has been prepared by a process which comprises cross-linking the second organic polymer under dynamic mixing conditions in the presence of the second particulate filler.
- 2. A composition according to claim 1 wherein the second polymer is polyethylene.
- 3. A composition according to claim 2 wherein the first polymer is polyethylene.
- 4. A composition according to claim 1 wherein the first particulate conductive filler has been crosslinked by means of a chemical cross-linking agent.
- 5. A composition according to claim 4 wherein the chemical cross-linking agent comprises peroxide.
- 6. A composition according to claim 4 wherein the first particulate conductive filler has been prepared by a process in which there is used at least 3% by weight of the cross-linking agent, the percentage being based on the total weight of the composition being crosslinked.
- 7. A composition according to claim 6 wherein at least 4% of the chemical cross-linking agent is used.
- 8. A composition according to claim 7 wherein at least 5% of the chemical cross-linking agent is used.
- 9. A process for the preparation of a composition which comprises
- (a) a continuous matrix comprising a first organic polymer, and
- (b) a first particulate conductive filler which is distributed in the matrix and maintains its identity therein, and each particle of which comprises a crosslinked mixture of a second organic polymer and a second particulate conductive filler which is distributed in the second polymer;
- which process comprises
- (1) mixing the second organic polymer with the second particulate conductive filler and a chemical cross-linking agent under a dynamic mixing condition which (i) disperses the second particulate conductive filler in the second organic polymer, (ii) crosslinks the second organic polymer, and (iii) results in the formation of the first particulate conductive filler; and
- (2) dispersing the crosslinked first particulate conductive filler from step (1) in the first organic polymer.
- 10. A process according to claim 9 wherein the particulate filler from step (1) is further comminuted prior to dispersion in step (2).
- 11. A process according to claim 9 wherein there is used at least 3% by weight of the cross-linking agent, the percentage being based on the total weight of the composition being crosslinked.
- 12. A process according to claim 11 wherein at least 4% of the chemical cross-linking agent is used.
- 13. A process according to claim 12 wherein at least 5% of the chemical cross-linking agent is used.
- 14. A process according to claim 9 wherein the mixing under dynamic mixing conditions in step (1) is achieved by means of high shear mixing equipment.
- 15. A process for the preparation of a composition which comprises
- (a) a continuous matrix comprising a first organic polymer, and
- (b) a first particulate conductive filler which is distributed in the matrix and maintains its identity therein, and each particle of which comprises a crosslinked mixture of a second organic polymer and a second particulate conductive filler which is distributed in the second polymer;
- which process comprises
- (1) dispersing the second particulate conductive filler in the second organic polymer;
- (2) forming the dispersion of step (1) into pellets;
- (3) blending the pellets of step (2) with a chemical cross-linking agent and mixing the blend under dynamic mixing conditions which crosslink the second organic polymer and result in the formation of the first particulate conductive filler; and
- (4) dispersing the crosslinked first particulate conductive filler from step (3) in the first organic polymer.
- 16. A process according to claim 15 wherein there is used at least 3% by weight of the cross-linking agent, the percentage being based on the total weight of the composition being crosslinked.
- 17. A process according to claim 16 wherein at least 4% of the chemical cross-linking agent is used.
- 18. A process according to claim 17 wherein at least 5% of the chemical cross-linking agent is used.
- 19. A process for the preparation of a composition which comprises
- (a) a continuous matrix comprising a first organic polymer, and
- (b) a first particulate conductive filler which is distributed in the matrix and maintains its identity therein, and each particle of which comprises a mixture of (i) a second organic polymer, (ii) a second particulate conductive filler which is distributed in the second polymer, and (iii) an inert particulate filler which is distributed in the second polymer;
- which process comprises
- (1) dispersing the second particulate conductive filler and the inert particulate filler in the second organic polymer;
- (2) melt-blending the dispersion from step (1);
- (3) cross-linking and comminuting the mixture from step (2) to form the first particulate conductive filler; and
- (4) dispersing the comminuted mixture from step (3) in the first organic polymer.
- 20. A process according to claim 17 wherein the inert particulate filler comprises titanium dioxide.
- 21. A process according to claim 17 wherein the inert particulate filler comprises zinc oxide.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. equivalent of copending, commonly assigned International Application No. PCT/US88/02484, filed Jul. 21, 1988 by Barma, Chan, Mohebban, Rosenzweig, and Kurjatko, which is a continuation-in-part of copending, commonly assigned application Ser. No. 75,929 filed Jul. 21, 1987 by Barma, Chan, Mohebban and Rosenzweig, now U.S. Pat. No. 5,106,540, which is itself a continuation-in-part of copending commonly assigned application Ser. No. 818,846 filed Jan. 14, 1986 by Pradeep Barma now abandoned and of commonly assigned application Ser. No. 818,845 filed Jan. 14, 1986, by Nachum Rosenzweig, now abandoned. The entire disclosure of each of those applications is incorporated herein by reference.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/US88/02484 |
7/21/1988 |
|
|
1/11/1990 |
1/11/1990 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO89/00755 |
1/26/1989 |
|
|
US Referenced Citations (11)
Foreign Referenced Citations (19)
Number |
Date |
Country |
038718 |
Oct 1981 |
EPX |
138424 |
Apr 1985 |
EPX |
179265 |
Apr 1986 |
EPX |
181587 |
May 1986 |
EPX |
189128 |
Jul 1986 |
EPX |
231068 |
Aug 1987 |
EPX |
1810829 |
Jul 1969 |
DEX |
3107489A |
Sep 1982 |
DEX |
2238733 |
Jul 1974 |
FRX |
51-32983 |
Mar 1976 |
JPX |
59-122524 |
Jul 1984 |
JPX |
60-115678 |
Jun 1985 |
JPX |
63-123665 |
Jun 1986 |
JPX |
62-37903 |
Feb 1987 |
JPX |
WO8900098 |
Jan 1989 |
WOX |
435003 |
Aug 1984 |
SEX |
1195076 |
Jun 1970 |
GBX |
1457157 |
Dec 1976 |
GBX |
2065430A |
Jun 1981 |
GBX |
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
75929 |
Jul 1987 |
|
Parent |
818846 |
Jan 1986 |
|