摘要:
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.
摘要:
A thermoplastic material has a) from 5% weight to 95% by weight, preferably from 10% by weight to 60% by weight, of vulcanized rubber in a subdivided form; b) from 5% by weight to 95% by weight, preferably from 40% by weight to 90% by weight, of at least one heterophase copolymer having a thermoplastic phase made from a propylene homopolymer or copolymer and an elastomeric phase made from a copolymer of ethylene with an α-olefin, preferably with propylene; c) from 0% by weight to 90% by weight, preferably from 0% by weight to 50% by weight, of at least one α-olefin homopolymer or copolymer different from b); the amounts of a), b) and c) being expressed with respect to the total weight of a)+b)+c). The thermoplastic material shows improved mechanical properties, in particular, improved elongation at break.
摘要:
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.
摘要:
A thermoplastic material has a) from 5% weight to 95% by weight, preferably from 10% by weight to 60% by weight, of vulcanized rubber in a subdivided form; b) from 5% by weight to 95% by weight, preferably from 40% by weight to 90% by weight, of at least one heterophase copolymer having a thermoplastic phase made from a propylene homopolymer or copolymer and an elastomeric phase made from a copolymer of ethylene with an α-olefin, preferably with propylene; c) from 0% by weight to 90% by weight, preferably from 0% by weight to 50% by weight, of at least one α-olefin homopolymer or copolymer different from b); the amounts of a), b) and c) being expressed with respect to the total weight of a)+b)+c). The thermoplastic material shows improved mechanical properties, in particular, improved elongation at break.
摘要:
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.
摘要翻译:涂有阻燃组合物的自熄电缆,其具有:(a)密度为0.905至0.970g / cm 3的乙烯均聚物或共聚物,并且选自:乙烯均聚物:共聚物 的乙烯与α-烯烃; 乙烯与烯属不饱和酯的共聚物; 或其混合物; (b)乙烯与至少一种α-烯烃和任选与二烯的共聚物,所述共聚物(b)的密度为0.860-0.904g / cm 3,并且具有组成 分布指数大于45%; (c)赋予阻燃性能的量的天然氢氧化镁; 其中聚合物组分(a)和(b)中的至少一种包含可接枝到聚合物链上的可水解的有机硅烷基团。 优选在混合阻燃剂组合物期间通过向聚合物混合物中加入合适的硅烷化合物和自由基引发剂来引入硅烷基团。
摘要:
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. A related method for manufacturing a cable having improved mechanical properties and enhanced fire resistance includes the steps of preparing a polymer mixture with flame-retardant properties and extruding the mixture on a conductor optionally pre-coated with an insulating layer, in order to obtain a flame-retardant coating.
摘要:
A process for producing a rubber powder from a vulcanized rubber material by the steps of: a) feeding a grinding device with the vulcanized rubber material; b) contacting the vulcanized rubber material with at least one liquid coolant; c) introducing at least one grinding aid additive into the grinding device; d) operating the grinding device so as to grind the vulcanized rubber material to form a rubber powder, and e) discharging the rubber powder from the extruder.
摘要:
A tire for vehicle wheels, includes at least one structural element obtained by crosslinking a crosslinkable elastomeric composition including at least one vulcanized rubber in a subdivided form surface treated with at least one oxidizing agent; at least one diene elastomeric polymer, and at least one sulfur-based vulcanizing agent. A surface treatment process of vulcanized rubber and crosslinkable elastomeric composition is obtained with the vulcanized rubber in a subdivided form surface treated with at least one oxidizing agent.
摘要:
Cable comprising at least one conductor and at least a fire resistant coating layer including a composition comprising: (a) at least an organic polymer having a combustion temperature range comprised between a minimum value T1 and a maximum value T2; (b) at least a glass frit; (c) at least an inert compound; wherein:—said inert compound (c) has a softening point or a melting temperature of not less than 1000° C.;—said glass frit (b) reaches a viscosity of between 107 poise and 108 poise in a selected temperature range including the combustion temperature range of said organic polymer (a), said selected temperature range being such that said glass frit (b) flows over said inert compound (c) and the burned organic polymer (a) so as to form a solid char fire resistant coating layer.
摘要:
A thermoplastic elastomeric material includes a vulcanized rubber in a subdivided form surface-grafted with at least one vinyl polymer, wherein the amount of the surface-grafted vinyl polymer is not lower than 60% by weight, preferably not lower than 70% by weight, more preferably not lower than 80% by weight, with respect to the total weight of the surface-grafted vinyl polymer and the vulcanized rubber in a subdivided form.