摘要:
A cable having one or more electrical conductors or a core of electrical conductors, each electrical conductor or core being surrounded by an insulating composition, essentially free from water tree growth inhibitors, having (i) a polyethylene having a density in the range of 0.860 to 0.940 gram per cubic centimeter; and, based on 100 parts by weight of component (i), (ii) about 0.2 to about 1 part by weight of a homopolymer of propylene with the proviso that the insulating composition is extruded at a temperature below the melting point of the homopolymer of propylene.
摘要:
Scorch is inhibited during the free-radical crosslinking of a crosslinkable polymer, e.g., an EPDM, by incorporating into the polymer before melt processing and crosslinking a scorch inhibiting amount of a derivative, preferably an ether, ester or urethane derivative, of a TEMPO compound, e.g., 4-hydroxy-tetrahydrocarbylpiperidin-1-oxyl. The scorch inhibitors of this invention perform as well, if not better, than their 4-hydroxy-tetrahydrocarbylpiperidin-1-oxyl counterparts in similar polymer compositions and under similar conditions in terms of scorch inhibition and ultimate degree of crosslinking, but exhibit less volatility and less migration within the polymer composition.
摘要:
The present invention is a communication cable comprising a plurality of twisted pair conductors, a separator, and a communication cable jacket enclosing the plurality of twisted pair conductors and the separator. The communication cable passes the requirements of NFPA-262. In particular, the separator is polyolefin-based and achieves the desired electrical and flame retardant properties. The present invention is also a method for selecting a composition for preparing the separator and a method for preparing a communications cable therefrom.
摘要:
For a flame retardant came, it has been surprisingly found that an insulated conductor, having at least two insulation layers, a composite dielectric constant less than or equal to 2.6, and a composite dissipation factor less than or equal to 0.005, can be prepared even though one of the insulation layers has a dielectric constant greater than 2.6 or a dissipation factor greater than 0.005. It has also been surprisingly found that an insulated conductor, having a composite dielectric constant less than or equal to 2.6 and a composite dissipation. factor less than or equal to 0.005, can be prepared with a non-halo-enated polyolefin as an insulation layer polymer, where the polyolefin having relatively poor dielectric/dissipative properties and the insulation layer composition being substantially free of halogenated or antimony trioxide flame retardant additives.
摘要:
The present invention is a flame retardant composition comprising (a) a first ethylene polymer; (b) a second ethylene polymer having a density less than 0.95 grams/cubic centimeter and being modified with an unsaturated aliphatic diacid anhydride; (c) a flame retardant; and (d) an ultra high molecular weight polysiloxane. The invention also includes a coating prepared from the flame retardant composition as well as a wire-and-cable construction made by applying the coating over a wire or a cable. The invention also includes articles prepared from the flame retardant composition, such as extruded sheets, thermoformed sheets, infection-molded articles, coated fabrics, construction materials and automotive materials.
摘要:
A high-voltage direct current cable insulation is made from a blend which includes an ethylene copolymer, such as ethylene-alpha olefin copolymer, with low crystallinity to reduce physical space charge trapping sites, a polar polymer modifier in an effective amount to enhance local conductivity to leak space charge quickly when local stress is enhanced, and an ion scavenger to stabilize or neutralize the space charge to provide a composition which is an effective high-voltage DC cable insulation. A high-voltage direct current cable semiconductive shield is made from a blend that includes an ethylene copolymer, a carbon black having a low level of ionic species, a polar polymer modifier, and an ion scavenger.
摘要:
A composition comprising:(a) one or more crosslinked ethylene/vinyl acetate copolymers, each copolymer having a vinyl acetate content in the range of about 10 to about 40 percent by weight based on the weight of the copolymer and an average melt index in the range of about 1 to about 50 grams per 10 minutes; and, for each 100 parts by weight of component (a),(b) as a coupling agent, about 5 to about 85 parts by weight of an olefin-acrylate terpolymer containing about 0.5 to about 5 parts by weight of an anhydride of an unsaturated diacid per 100 parts by weight of polyolefin incorporated into the polyolefin through copolymerization; and(c) about 135 to about 370 parts by weight of a hydrated inorganic flame retardant filler.
摘要:
The invention provides an article comprising a first layer and a second layer, and wherein the first layer is formed from a first composition comprising an ethylene/α-olefin/diene interpolymer, an isoprene rubber (synthetic), a natural rubber, a butadiene rubber, a styrene butadiene rubber, a chloroprene rubber, a nitrile rubber, a hydrogenated nitrile rubber, a chlorinated polyethylene, a chlorosulfonated polyethylene, an ethylene/propylene rubber, an ethylene/diene copolymer, a fluoro rubber, a polyurethane, a silicone rubber, or a combination thereof; and wherein the second layer is formed from a second composition comprising a butyl rubber, a halobutyl rubber, polyvinylidene chloride, a brominated polymer derived from a copolymer of isobutylene and p-methyl styrene, a nitrile rubber, a chloroprene rubber, a chlorosulfonated polyethylene, a chlorinated polyethylene, a polyurethane, a fluoro rubber, or a combination thereof.
摘要:
Scorch is inhibited during the free-radical crosslinking of a crosslinkable polymer, e.g., an EPDM, by incorporating into the polymer before melt processing and crosslinking a scorch inhibiting amount of a derivative, preferably an ether, ester or urethane derivative, of a TEMPO compound, e.g., 4-hydroxy-tetrahydrocarbylpiperidin-1-oxyl. The scorch inhibitors of this invention perform as well, if not better, than their 4-hydroxy-tetrahydrocarbylpiperidin-1-oxyl counterparts in similar polymer compositions and under similar conditions in terms of scorch inhibition and ultimate degree of crosslinking, but exhibit less volatility and less migration within the polymer composition.