Hydrosilylation crosslinking of polyolefin cable components
A method of crosslinking a polyolefin resin with a silyl hydride crosslinking agent is disclosed. Crosslinkable compositions containing a polyolefin resin having about 0.9% to about 10% diene groups and a silyl hydride crosslinking agent are also disclosed.
1. A cable comprising a covering formed from a composition, the composition comprising:
a polyolefin resin comprising about 1% to about 7% by weight of diene groups, wherein the polyolefin resin comprises about 50% by weight or more of one or more of low-density polyethylene, linear low-density polyethylene, high-density polyethylene, and polypropylene;
a silyl hydride crosslinking agent;
a catalyst; and
2.5 to 5 parts by weight of a filler; and
wherein the diene groups are crosslinked with the silyl hydride crosslinking agent.
2. The cable of claim 1 , wherein the polyolefin resin comprises about 50% by weight or more of one or more of low density polyethylene and linear low density polyethylene; and
wherein the diene groups comprise grafted diene groups; and
wherein the diene groups comprise vinyl functional groups.
3. The cable of claim 2 , wherein the polyolefin resin further comprises about 5% to about 40% by weight of ethylene propylene diene terpolymer.
4. The cable of claim 1 , wherein the composition further comprises a stabilizer, the stabilizer comprising one or more of an antioxidant, a UV stabilizer, a heat stabilizer, a lead stabilizer, and a metal deactivator.
5. The cable of claim 1 , wherein the filler comprises one or more of talc, silica, and calcined clay.
6. The cable of claim 1 , wherein the composition comprises about 2 parts to about 10 parts by weight of the silyl hydride crosslinking agent; and
wherein the silyl hydride crosslinking agent comprises one or more of hydride terminated polydimethyl siloxane, hydride terminated polymethyl siloxane, tris(dimethylsiloxy)phenyl silane, and 1,10 disiladecane.
7. The cable of claim 1 , wherein the catalyst comprises a Column VIII metal, cobalt, iron, nickel, or a metal complex thereof; and
wherein the catalyst comprises a concentration of the metal content from about 1 part-per-million (ppm) to about 1,000 ppm.
8. The cable of claim 7 , wherein the catalyst comprises a platinum complex.
9. The cable of claim 1 , wherein the covering exhibits a TS5 Mooney Scorch (TS5) of about 15 or more when measured at 121° C.
10. The cable of claim 1 , wherein the covering has an elongation at break of about 150% or more.
11. The cable of claim 1 , wherein the covering passes the Hot Creep Test at 150° C.
12. The cable of claim 1 , wherein the covering has a tan delta at about 23° C. of about 0.3% or less.
13. The cable of claim 1 , wherein the covering has a gel content of about 50% or more when measured in accordance to ASTM D2765.
14. The cable of claim 1 , wherein the covering is one or more of an insulation layer and a jacket layer.