Abstract: Optical fiber having a glass portion; at least one protective coating of thermoplastic material having at least one thermoplastic elastomer; the thermoplastic material having the following characteristics: a modulus of elasticity value at +25° C. lower than 150 MPa, preferably at least 10 Mpa, more preferably higher than 20 Mpa, and a Vicat point higher than 85° C., preferably higher than 120° C., more preferably lower than 350° C. Preferably, the coating is a single protective coating directly positioned onto the glass portion.

Abstract: A cable having at least one conductor and at least a fire resistant coating layer. The fire resistant coating has (a) at least an organic polymer having a combustion temperature range between a minimum value T1 and a maximum value T2; (b) at least a glass frit; and (c) at least an inert compound. The inert compound (c) has a softening point or a melting temperature of not less than 1000° C.; the glass frit (b) reaches a viscosity of between 107 poise and 108 poise in a selected temperature range including the combustion temperature range of the organic polymer (a). The selected temperature range is such that the glass frit (b) flows over the inert compound (c) and the burned organic polymer (a) so as to form a solid char fire resistant coating layer.

Abstract: Self-extinguishing cable coated with a flame-retardant composition having: (a) an ethylene homopolymer or copolymer having a density of from 0.905 to 0.970 g/cm3, and being selected from: ethylene homopolymers: copolymers of ethylene with an alpha-olefin; copolymers of ethylene with an ethylenically unsaturated ester; or mixtures thereof; (b) a copolymer of ethylene with at least one alpha-olefin, and optionally with a diene, said copolymer (b) having a density of from 0.860 to 0.904 g/cm3, and having a composition distribution index greater than 45%; (c) natural magnesium hydroxide in an amount such as to impart flame-retardant properties; wherein at least one of the polymeric components (a) and (b) contains hydrolyzable organic silane groups grafted onto the polymer chain. The silane groups are preferably introduced during compounding of the flame-retardant composition by adding to the polymer mixture a suitable silane compound and a radical initiator.

Abstract: Process for producing cables, in particular electrical cables for low-voltage power transmission or for telecommunications, which have self-extinguishing properties and produce a low level of fumes, in which the flame-retardant coating layer is obtained by extruding a flame-retardant composition comprising a polymer base, an inorganic flame-retardant filler and a dehydrating agent. The presence of the dehydrating agent makes it possible to obtain a smooth and uniform flame-retardant layer which is virtually free of pores.

Abstract: The present invention is an improved electric insulation composition of a polymer and an additive that reduces water treeing due to electrical aging in water. The polymer additive is a hydrophobic/hydrophilic material with good compatibility with the polymer. The present invention is also a method of preventing electrical breakdown due to the formation of water trees by forming electrical cables with the insulation containing the disclosed anti-treeing additives.

Abstract: Electrical cable having at least one conducting element, at least one polyolefin-based insulating covering layer, in which said insulating covering layer has at least one voltage stabilizer, said voltage stabilizer being a benzophenone substituted with at least one group selected from alkyl, arylalkyl and alkylaryl wherein said group: a) is linked to a phenyl ring of the benzophenone directly or via an oxygen bridge (-O-); b) contains, optionally, one or more oxygen bridges (-O-); and c) is optionally linked to a phenyl ring of at least one or other benzophenone group, provided that when said at least one group is an alkyl, optionally substituted, the carbon atom of said alkyl which is directly linked to a phenyl ring of said benzophenone is tertiary. A polyolefin-based insulating composition having at least one voltage stabilizer as described above.

Abstract: A flame-retardant composition includes a crystalline propylene homopolymer or copolymer, a copolymer of ethylene with at least one alpha-olefin having from 3 to 12 carbon atoms, and optionally with a diene, the copolymer of ethylene being characterized by a composition distribution index greater than 45%, the index being defined as a weight percentage of copolymer molecules having an alpha-olefin content within 50% of an average total molar content of alpha-olefin, and natural magnesium hydroxide in amounts such as to impart flame-retardant properties. A related cable with self-extinguishing properties includes a conductor and a flame-retardant coating. The flame-retardant coating includes the flame-retardant composition.

Abstract: A self-extinguishing cable and the flame-retardant composition used therein are disclosed. The cable comprises at least one flame-retardant coating comprising a) at least one polymer material; b) at least one inorganic hydrated flame-retardant filler; and c) at least one silane substituted with at least one C10-C40 hydrocarbon group and with at least one hydrolysable group. The self-extinguishing cable shows improved insulating properties in water or in the presence of a moist environment without adversely affecting self-extinguishing properties.

Abstract: The present invention is an improved electric insulation composition of a polymer and an additive that reduces water treeing due to electrical aging in water. The polymer additive is a hydrophobic/hydrophilic material with good compatibility with the polymer. The present invention is also a method of preventing electrical breakdown due to the formation of water trees by forming electrical cables with the insulation containing the disclosed anti-treeing additive.

Abstract: Cables, in particular electrical cables for low-voltage power transmission or for telecommunications, or alternatively for data transmission or mixed power/telecommunications cables, which have self-extinguishing properties and produce a low level of fumes, wherein a coating layer based on a polymer material and on a flame-retardant inorganic filler is present. The polymer material includes a heterophase copolymer having an elastomeric phase based on ethylene copolymerized with an &agr;-olefin and a thermoplastic phase based on propylene. The elastomeric phase is at least 45% by weight relative to the total weight of the heterophase copolymer and the heterophase copolymer is substantially devoid of crystallinity deriving from polyethylene sequences.

Abstract: Electrical cable having at least one conducting element, at least one polyolefin-based insulating covering layer, in which said insulating covering layer has at least one voltage stabilizer, said voltage stabilizer being a benzophenone substituted with at least one group selected from alkyl, arylalkyl and alkylaryl wherein said group: a) is linked to a phenyl ring of the benzophenone directly or via an oxygen bridge (—O—); b) contains, optionally, one or more oxygen bridges (—O—); and c) is optionally linked to a phenyl ring of at least one or other benzophenone group, provided that when said at least one group is an alkyl, optionally substituted, the carbon atom of said alkyl which is directly linked to a phenyl ring of said benzophenone is tertiary. A polyolefin-based insulating composition having at least one voltage stabilizer as described above.

Abstract: A polymeric composition for coating electric cables for power transmission at medium/high voltage, having an improved resistance against the formation of the so-called water trees, comprises a polymeric polyolefin base including, in parts by weight to the total weight thereof, from 0.5 to 15 parts of ester groups and from 0.01 to 5 parts of epoxy groups. Electric cables according to the invention comprise at least one electrically conducting core (2) and an insulation coating (5) comprising the aforementioned polymeric composition.

Abstract: Mass-impregnated electrical cable, particularly for carrying high voltage direct current, having an insulation in which, around the insulating layer impregnated with an insulating fluid, a containing layer is provided broadly includes at least one winding of a tape of a semiconducting elastomeric material, which exerts an effective action of containing the insulating fluid, while preventing formation of micro-cavities within the impregnated insulating layer. The material constituting the tape has high physical-chemical resistance to the degrading action of the components of the insulating fluid, both in the cold state and, in particular, at the operating temperature of the cable.

Abstract: A polymeric composition for coating electric cables for power transmission at medium/high voltage, having an improved resistance against the formation of the so-called water trees, comprises a polymeric polyolefin base including, in parts by weight to the total weight thereof, from 0.5 to 15 parts of ester groups and from 0.01 to 5 parts of epoxy groups. Electric cables according to the invention comprise at least one electrically conducting core (2) and an insulation coating (5) comprising the aforementioned polymeric composition.

Abstract: Self-extinguishing cable coated with a flame-retardant composition having: (a) an ethylene homopolymer or copolymer having a density of from 0.905 to 0.970 g/cm3, and being selected from: ethylene homopolymers: copolymers of ethylene with an alpha-olefin; copolymers of ethylene with an ethylenically unsaturated ester; or mixtures thereof; (b) a copolymer of ethylene with at least one alpha-olefin, and optionally with a diene, said copolymer (b) having a density of from 0.860 to 0.904 g/cm3, and having a composition distribution index greater than 45%; (c) natural magnesium hydroxide in an amount such as to impart flame-retardant properties; wherein at least one of the polymeric components (a) and (b) contains hydrolyzable organic silane groups grafted onto the polymer chain. The silane groups are preferably introduced during compounding of the flame-retardant composition by adding to the polymer mixture a suitable silane compound and a radical initiator.

Abstract: A polymeric composition for coating electric cables for power transmission at medium/high voltage, having an improved resistance against the formation of the so-called water trees, comprises a polymeric polyolefin base including, in parts by weight to the total weight thereof, from 0.5 to 15 parts of ester groups and from 0.01 to 5 parts of epoxy groups. Electric cables according to the invention comprise at least one electrically conducting core (2) and an insulation coating (5) comprising the aforementioned polymeric composition.

Abstract: A polymeric composition for coating electric cables for power transmission at medium/high voltage, having an improved resistance against the formation of the so-called water trees, comprises a polymeric polyolefin base including, in parts by weight to the total weight thereof, from 0.5 to 15 parts of ester groups and from 0.01 to 5 parts of epoxy groups. Electric cables according to the invention comprise at least one electrically conducting core (2) and an insulation coating (5) comprising the aforementioned polymeric composition.