Provided is an ultrathin low-voltage electric wire for an automobile that includes a conductor part and an insulating layer covering the outer periphery of the conductor part, wherein the insulating layer includes a resin composition containing 100 parts by mass of a vinyl chloride resin, 29 to 31 parts by mass of a trimellitic acid-based ester plasticizer, 0.3 to 1.0 parts by mass of a processing aid, and 7 to 11 parts by mass of a thermal stabilizer, the conductor part has a cross-sectional area of 0.13±0.02 mm.sup.2, and the insulating layer has a thickness of 0.16 to 0.25 mm.

A heat-resistant electric wire including a core wire and a coating that covers the core wire. The coating is formed from a modified fluorine-containing copolymer that is obtained by irradiating a copolymer with radiation at an exposure of 250 kGy or lower at a temperature of not higher than the melting point of the copolymer. The copolymer is at least one copolymer selected from a copolymer including a tetrafluoroethylene unit and a perfluoro(alkyl vinyl ether) unit and a copolymer including a tetrafluoroethylene unit and a hexafluoropropylene unit.

The invention belongs to the field of polymers, and relates to an anhydride group-containing polypropylene graft for an insulating material and preparation method thereof. The anhydride group-containing polypropylene graft comprises structural units derived from a polypropylene copolymer, structural units derived from an anhydride monomer and structural units derived from an alkenyl-containing polymerizable monomer; the content of the structural units derived from the anhydride monomer and the alkenyl-containing polymerizable monomer and in a grafted state in the anhydride group-containing polypropylene graft is 0.1 to 5 wt %, based on the weight of the anhydride group-containing polypropylene graft; and, the molar ratio of the structural units derived from the anhydride monomer to the structural units derived from the alkenyl-containing polymerizable monomer in the anhydride group-containing polypropylene graft is 1:1-20; the polypropylene copolymer has at least one of the following characteristics: the comonomer content is 0.5 to 40 mol %; the content of xylene solubles is 2 to 80 wt %; the comonomer content in the xylene solubles is 10 to 70 wt %; the intrinsic viscosity ratio of the xylene solubles to the polypropylene copolymer is 0.3 to 5. The anhydride group-containing polypropylene graft of the invention can give consideration to both mechanical property and electrical property at a higher working temperature.

The invention discloses a carbon nanotube/polyetherimide/thermosetting resin dielectric composite and a preparation method therefor. 100 parts by weight of polyetherimide and 1-7 parts by weight of carbon nanotube are mixed uniformly in an Haake torque melt cavity to obtain a carbon nanotubes/polyetherimide composite; 20 parts of the carbon nanotube/polyetherimide composite are dissolved in 100-150 parts of dichloromethane, then the mixed solution is added in 100 parts of molten thermocurable thermosetting resin, mixing, and heat preserving, stirring are performed until a mixture is formed in a uniform state, and curing and post-treating are performed to obtain a carbon nanotube/thermosetting resin dielectric composite, wherein the substrate thereof has a typical reverse phase structure, while the carbon nanotubes are dispersed in a polyetherimide phase. The composite has a relatively low percolation threshold, a high dielectric constant and a low dielectric loss. The preparation method of the present invention has a simple process and is suitable for large-scale production.

A copolymer of ethylene with silane groups containing comonomer that is produced in a high pressure radical polymerisation process comprising the steps of: (a) compressing ethylene together with the silane groups containing comonomer under pressure in a compressor, wherein a compressor lubricant is used for lubrication, (b) polymerising ethylene together with the silane groups containing comonomer in a polymerisation zone, (c) separating the obtained ethylene from the unreacted products and recovering the separated ethylene copolymer in a recovery zone, wherein in step a) the compressor lubricant comprises a mineral oil and ethylene copolymer has a silane groups containing comonomer content of 0.5 to 3 wt % and an MFR2 of 0.3 to 10 g/10 min. The co polymer of ethylene with silane groups containing comonomer can be used.

A halogen-free crosslinked resin composition includes a base polymer including as a main component (a) an ethylene vinyl acetate copolymer and (b) an acid modified polyolefin resin having a differential scanning calorimetry glass transition temperature Tg of not higher than −55 degrees Celsius in a mass ratio (a):(b) of 70:30 to 100:0, the base polymer including 50 to 70% by mass of vinyl acetate, 0.5 to 10 parts by mass of a silicone rubber with respect to 100 parts by mass of the base polymer, and 100 to 250 parts by mass of a metal hydroxide with respect to 100 parts by mass of the base polymer.

Provided are a core electric wire for a multi-core cable superior in flex resistance at low temperature, and a multi-core cable employing the same. The core electric wire for a multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer covering the conductor, a principal component of the insulating layer being a copolymer of ethylene and an α-olefin having a carbonyl group; the α-olefin content in the copolymer being 14% to 46% by mass; and a mathematical product C*E being 0.01 to 0.9, wherein C is a linear expansion coefficient of the insulating layer at from 25° C. to −35° C., and E is a modulus of elasticity thereof at −35° C. Average area of the conductor in the transverse cross section is 1.0 to 3.0 mm.sup.2. Average diameter of the element wires in the conductor is 40 to 100 μm, and number of the element wires is 196 to 2,450.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 μm to 100 μm, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an α-olefin having a carbonyl group.

A fire retardant composition is disclosed. The composition includes polyvinyl chloride, a plasticizer, a brominated fire retardant additive, a fire retardant synergist, and a metal stabilizer. Cable separators formed of the fire retardant composition are also disclosed.

Oxacycloolefinic polymers as typically obtained by metathesis polymerization using Ru-catalysts, show good solubility and are well suitable as dielectric material in electronic devices such as capacitors and organic field effect transistors.