The copolymerization of ethylene (E) and methoxy polyethylene glycol methacrylate (MPEGMA) produces the copolymer co-E-MPEGMA. These copolymers are distinct from polyethylene, e.g., low density polyethylene (LDPE) grafted with MPEGMA, i.e., g-E-MPEGMA, and are useful in the preparation of insulation sheaths for medium, high and extra-high voltage cables. Such cables exhibit good water tree retardance.

A cable accessory for injecting fluid into a cable. The accessory has first and second ends configured to be coupled to the cable and an external cable accessory, respectively. The accessory has an injection port configured to introduce the fluid to a stranded conductor of the cable. The accessory may include a body and conductive rod. The body defines a through-channel configured to receive the conductor. The rod has a first portion that extends outwardly from the second end to be received inside the external cable accessory and to form an electrical connection therewith. The rod has a second portion configured to be coupled to the conductor and form an electrical connection therewith. The second portion (with the conductor coupled thereto) is positionable inside the through-channel with the first portion extending outward from the second end. The fluid is injectable into the conductor through injection port, which extends into the through-channel.

An assembled wire has a substantially rectangular cross section, and is formed by assembling a plurality of strands. Each strand has a conductor portion and a strand insulating layer covering the conductor portion. At least a part of the assembled plurality of strands in the longitudinal direction is covered with an outer insulating layer. The strand is formed as follows. First, the strand insulating layer is coated on the outer periphery of the conductor portion. At this time, a large number of voids are formed in a resin constituting the strand insulating layer. From this state, the strand is formed, for example, by collapsing the strand insulating layer by heating and pressurizing. At this time, it is possible to uniformly collapse the strand insulating layer by crushing the internal voids. Therefore, the voids in the strand are crushed and flattened in the thickness direction of the strand insulating layer over the entire periphery.

An insulated wire according to one embodiment of the present invention includes a linear conductor, and one or a plurality of insulating layers that are laminated on an outer peripheral surface of the conductor, wherein at least one layer of the one or plurality of insulating layers includes a plurality of pores, and a closed porosity within the plurality of pores is 80% by volume or higher.

A thin micro-multilayer electrical insulator having a plurality of layers of polymeric materials is high performance and lightweight. The insulator provides a structured material with improved dielectric strength and partial corona discharge resistance that can be used in high voltage and high temperature applications. The durable insulator is well suited for use in insulating high voltage aircraft wiring and power transmission composites in hybrid and all electric airplanes. The insulator can have multiple layers of different polymeric materials such as fluorine-containing polymers and polyimides.

A cable accessory for injecting fluid into a cable. The accessory has first and second ends configured to be coupled to the cable and an external cable accessory, respectively. The accessory has an injection port configured to introduce the fluid to a stranded conductor of the cable. The accessory may include a body and conductive rod. The body defines a through-channel configured to receive the conductor. The rod has a first portion that extends outwardly from the second end to be received inside the external cable accessory and to form an electrical connection therewith. The rod has a second portion configured to be coupled to the conductor and form an electrical connection therewith. The second portion (with the conductor coupled thereto) is positionable inside the through-channel with the first portion extending outward from the second end. The fluid is injectable into the conductor through injection port, which extends into the through-channel.

A fitting for injecting a first fluid into an injection port of a cable accessory. The fitting includes at least one seal positioned on an injection nozzle. The nozzle is configured to be inserted into the port and has an internal fluid passageway through which the first fluid is injected into the accessory. The seal forms at least one fluid tight seal between the nozzle and the port. The fluid tight seal prevents the first fluid from exiting the accessory and flowing into an outer portion of the port and prevents a second fluid from flowing into an inner portion of the port. The first and second fluids have first and second voltage potentials, respectively. The second voltage potential is different from the first voltage potential. The seal isolates the first and second voltage potentials by isolating the first fluid from the second fluid.

A polyolefin-and-poly (2-alkyl-2-oxazoline) formulation comprising (A) an olefin-based (co) polymer, (B) a poly (2-alkyl-2-oxazoline) (co) polymer, and (C) an antioxidant. Also a method of making the composition; a crosslinked polyolefin product made by curing the composition; manufactured articles comprising a shaped form of the inventive formulation or product; and methods of using the inventive formulation, product, or articles.

The present invention relates to stabilising compositions, particularly stabilising compositions which can be used to stabilise insulation or semi-conductive compositions, such as are used for electrically insulating wires and cables. The stabilising composition comprises: a first stabilising component comprising at least one fully hindered phenolic antioxidant; a second stabilising component comprising at least one partially hindered phenolic antioxidant; and a third stabilising component comprising at least one sulphur-containing antioxidant.

An insulated wire according to one embodiment of the present invention includes a linear conductor, and one or a plurality of insulating layers that are laminated on an outer peripheral surface of the conductor, wherein at least one layer of the one or plurality of insulating layers includes a plurality of pores, and a closed porosity within the plurality of pores is 80% by volume or higher.