Moisture-cured wire and cable constructions
Articles made from a moisture-crosslinkable, polymeric composition comprising in weight percent based on the weight of the composition: (A) 10 to 99.99 wt % of a nonpolar ethylenic polymer grafted with silane functionality (Si-g-npPE), the npPE having the following properties before grafting: (1) a vinyl content of 0.2 to 0.7 per 1,000 carbon atoms, (2) a melt index of 1.5 to 7.0 dg/min, (3) a density of 0.913 to 0.965 g/cc, and (4) a molecular weight distribution (Mw/Mn) of equal to or less than 8; (B) 0.01 to 20 wt % of a silanol condensation catalyst; and (C) 0 to 70 wt % of a flame retardant additive; exhibit one or more of desirable (a) silane grafting efficiency; (b) hot creep performance as a cable jacket/insulation after moisture crosslinking; (c) retained dielectric strength after glancing impact as a moisture crosslinked cable construction; and (d) crush resistance as a moisture crosslinked cable construction.
1. A moisture-crosslinkable, polymeric composition comprising in weight percent (wt %) based on the weight of the composition:
(A) 10 to 99.99 wt % of a nonpolar ethylenic polymer grafted with silane functionality (Si-g-npPE), the npPE having the following properties before grafting:
(1) a vinyl content of 0.2 to 0.7 per 1,000 carbon atoms,
(2) a melt index (MI or I 2 ) of 1.5 to 7.0 decigrams per minute (dg/min),
(3) a density of 0.913 to 0.965 grams per cubic centimeter (g/cc), and
(4) a molecular weight distribution (MWD or Mw/Mn) of equal to or less than (≤)8;
(B) 0.01 to 20 wt % of a silanol condensation catalyst; and
(C) 0 to 70 wt % of a flame retardant additive.
2. The composition of claim 1 in which nonpolar ethylenic polymer is made in an uncatalyzed process.
3. The composition of claim 2 in which the nonpolar ethylenic polymer component of the Si-g-npPE is at least one of a high density polyethylene (HDPE); medium density polyethylene (MDPE); linear low density polyethylene (LLDPE); low density polyethylene (LDPE); very low density polyethylene (VLDPE); a homogeneously branched, linear ethylene/α-olefin copolymer; and a homogeneously branched, substantially linear ethylene/α-olefin polymer.
4. The composition of claim 3 further comprising a silane-grafted ethylene plastomer/elastomer.
5. The composition of claim 1 in which the silane-containing component of the Si-g-npPE is derived from a compound of the formula:
in which R′ is a hydrogen atom or methyl group; x and y are 0 or 1 with the proviso that when x is 1, y is 1; n is an integer from 1 to 12 inclusive, and each R″ independently is a hydrolyzable organic group having from 1 to 12 carbon atoms with the proviso that not more than one of the three R″ groups is an alkyl.
6. A moisture-crosslinkable, polymeric composition comprising in weight percent based on the weight of the composition:
(A) 4.00 to 99.67 wt % of a nonpolar ethylenic polymer (npPE) having:
(1) a vinyl content of 0.2 to 0.7 per 1,000 carbon atoms,
(2) an I 2 of 1.5 to 7.0 dg/min,
(3) a density of 0.913 to 0.965 g/cc, and
(4) MWD of equal to or less than (≤)8;
(B) 0.3 to 5 wt % of an alkoxysilane;
(C) 0.01 to 20 wt % of a silanol condensation catalyst;
(D) 0.02 to 1.0 wt % peroxide initiator; and
(E) 0 to 70 wt % of a flame retardant additive.
7. The composition of claim 6 in which nonpolar ethylenic polymer is made in an uncatalyzed process.
8. The composition of claim 6 in which the npPE is at least one of a high density polyethylene (HDPE); medium density polyethylene (MDPE); linear low density polyethylene (LLDPE); low density polyethylene (LDPE); very low density polyethylene (VLDPE); a homogeneously branched, linear ethylene/α-olefin copolymer; and a homogeneously branched, substantially linear ethylene/α-olefin polymer.
9. The composition of claim 8 further comprising an ethylene plastomer/elastomer.
10. The composition of claim 9 in which the silane-containing compound is of the formula:
in which R′ is a hydrogen atom or methyl group; x and y are 0 or 1 with the proviso that when x is 1, y is 1; n is an integer from 1 to 12 inclusive, and each R″ independently is a hydrolyzable organic group having from 1 to 12 carbon atoms with the proviso that not more than one of the three R″ groups is an alkyl.
11. The composition of claim 10 in which the flame retardant additive is a halogenated flame retardant is at least one of perchloropentacyclodecane; a Diels-Alder adduct of hexachlorocyclopentadiene with maleic anhydride; hexabromobenzene; pentabromoethylbenzene 2,4,6-tribromophenol; tribromophenyl allyl ether; ethylene-1,2-bis(pentabromophenyl); octaobromodiphenyl; poly(pentabromobenzyl)acrylate; pentabromodiphenyl ether; octabromodiphenyl ether; decabromodiphenyl ether; tetrachlorobisphenol A; tetrabromobisphenol A; bis(dibromopropyl)ether of tetrabromobisphenol A; tetrachlorophthalic anhydride; tetrabromophthalic anhydride; hexachloroendomethylenetetrahydrophthalic acid; ethylene-bis(tetrabromophthatmide); and hexabromocyclododecane.
12. The composition of claim 11 further comprising an inorganic antimony flame retardant.
13. The composition of 10 in which the flame retardant additive is halogen-free.
14. The composition of claim 6 in which the silanol condensation catalyst is at least one of an organic titanate and complexes or carboxylates of lead, cobalt, iron, nickel, zinc and tin.
15. An article made from a composition of claim 6 in which the article has an ACBD value of ≥20% after a glancing impact as measured by the UL 2556 Section 7.14, Edition Number: 4, Edition Date: Dec. 15, 2015 glancing impact test.
16. The article of claim 15 as a wire or cable coating.