Use of mixtures of monoperoxycarbonate peroxides for the cross-linking and composition of cross-linkable polymers
The use of peroxide(s) for cross-linking at least one polymer, the polymer having a homopolymer or copolymer of ethylene and especially the ethylene-vinyl acetate copolymer (EVA) or a mixture of the EVA with another homopolymer or copolymer of ethylene, and at least one peroxide, wherein the peroxide includes OO-tert-butyl O-isopropyl monoperoxycarbonate or OO-tert-amyl O-isopropyl monoperoxycarbonate and OO-tert-butyl-O-2-ethyl hexyl monoperoxycarbonate or OO-tert-amyl-O-2ethyl hexyl monoperoxycarbonate. Also, a cross-linkable composition including the peroxide and to a method for producing a cross-linked polymer as a result of the peroxide.
1. A crosslinkable composition comprising at least one ethylene-vinyl acetate (EVA) copolymer and a combination of peroxides, wherein the combination of peroxides comprises:
(i) O,O-tert-butyl O-isopropyl monoperoxycarbonate or O,O-tert-amyl O-isopropyl monoperoxycarbonate; and
(ii) O,O-tert-butyl O-2-ethylhexyl monoperoxycarbonate or O,O-tert-amyl O-2-ethylhexyl monoperoxycarbonate,
in a mass ratio of 40%/60% to 60%/40% of peroxide (i)/peroxide (ii),
wherein the total amount of peroxide (i) and peroxide (ii) represents between 0.2% and 4% of the mass amount of the polymer present in the composition.
2. The crosslinkable composition according to claim 1 , wherein the peroxide consists of a mixture of:
(a)
(i) O,O-tert-butyl O-isopropyl monoperoxycarbonate, or
(ii) O,O-tert-amyl O-isopropyl monoperoxycarbonate; and
(b)
(i) O,O-tert-butyl O-2-ethylhexyl monoperoxycarbonate, or
(ii) O,O-tert-amyl O-2-ethylhexyl monoperoxycarbonate (TAEC).
3. The crosslinkable composition according to claim 2 , wherein the mixture represents between 0.5% and 2.5% of the mass amount of the polymer present in the composition.
4. The crosslinkable composition according to claim 1 , wherein the ethylene-vinyl acetate (EVA) copolymer is present in the composition in a content ranging from 70% to 99.9% by weight relative to the weight of the composition.
5. The crosslinkable composition according to claim 1 , wherein the composition further comprises one or more crosslinking coagents or promoters.
6. The crosslinkable composition according to claim 1 , wherein a functional agent is present in the composition in a content ranging from 0.05% to 30% by weight relative to the weight of the composition.
7. A process for manufacturing a film of crosslinked polymer, wherein it comprises at least the following steps:
(a) extrusion in the form of a film of a crosslinkable composition according to claim 1 , and
(b) crosslinking of the crosslinkable composition after the extrusion step (a) for a time of not more than twenty minutes.
8. The crosslinkable composition according to claim 1 , wherein the mass ratio is 45%/55% to 55%/45% of these peroxide (i)/peroxide (ii).
9. The crosslinkable composition according to claim 1 , wherein the peroxide comprises O,O-tert-butyl O-isopropyl monoperoxycarbonate and O,O-tert-butyl O-2-ethylhexyl monoperoxycarbonate.
10. The crosslinkable composition according to claim 1 , wherein the peroxide comprises O,O-tert-butyl O-isopropyl monoperoxycarbonate and O,O-tert-amyl O-2-ethylhexyl monoperoxycarbonate.
11. The crosslinkable composition according to claim 1 , wherein the peroxide comprises O,O-tert-amyl O-isopropyl monoperoxycarbonate and O,O-tert-butyl O-2-ethylhexyl monoperoxycarbonate.
12. The crosslinkable composition according to claim 1 , wherein the peroxide comprises O,O-tert-amyl O-isopropyl monoperoxycarbonate and O,O-tert-amyl O-2-ethylhexyl monoperoxycarbonate.
13. The crosslinkable composition according to claim 1 , wherein the peroxide consists of O,O-tert-butyl O-isopropyl monoperoxycarbonate and O,O-tert-butyl O-2-ethylhexyl monoperoxycarbonate.
14. The crosslinkable composition according to claim 1 , wherein the peroxide consists of O,O-tert-butyl O-isopropyl monoperoxycarbonate and O,O-tert-amyl O-2-ethylhexyl monoperoxycarbonate.
15. The crosslinkable composition according to claim 1 , wherein the peroxide consists of O,O-tert-amyl O-isopropyl monoperoxycarbonate and O,O-tert-butyl O-2-ethylhexyl monoperoxycarbonate.
16. The crosslinkable composition according to claim 1 , wherein the peroxide consists of O,O-tert-amyl O-isopropyl monoperoxycarbonate and O,O-tert-amyl O-2-ethylhexyl monoperoxycarbonate.
17. The crosslinkable composition according to claim 1 , wherein, after crosslinking, the composition possesses an electrical resistivity by volume of 8.0E+15 ohm·cm to 1.0E+16 ohm·cm.
18. A crosslinkable composition comprising at least one ethylene-vinyl acetate (EVA) copolymer and at least one peroxide, wherein the peroxide comprises:
(i) O,O-tert-butyl O-isopropyl monoperoxycarbonate or O,O-tert-amyl O-isopropyl monoperoxycarbonate; and
(ii) O,O-tert-butyl O-2-ethylhexyl monoperoxycarbonate or O,O-tert-amyl O-2-ethylhexyl monoperoxycarbonate,
in a mass ratio of 40%/60% to 60%/40% of peroxide (i)/peroxide (ii),
wherein, after crosslinking, the composition possesses an electrical resistivity by volume of 8.0E+15 ohm·cm to 1.0E+16 ohm·cm, and
wherein the total amount of peroxide (i) and peroxide (ii) represents between 0.2% and 4% of the mass amount of the polymer present in the composition.