摘要:
A cable including at least one core having at least one transmissive element and at least one coating layer made from a coating material, wherein the coating material has at least a first polyethylene having a density not higher than 0.940 g/cm3, preferably not lower than 0.910 g/cm3, more preferably 0.915 g/cm3 to 0.938 g/cm3, and a Melt Flow Index (MFI), measured at 190° C. with a load of 2.16 Kg according to ASTM D1238-00 standard, of 0.05 g/10′ to 2 g/10′, preferably 0.1 g/10′ to 1 g/10′; the first polyethylene being obtained from a waste material; at least a second polyethylene having a density higher than 0.940 g/cm3, preferably not higher than 0.970 g/cm3, more preferably 0.942 g/cm3 to 0.965 g/cm3. Preferably, the coating layer is a cable external layer having a protective function.
摘要翻译:一种电缆,包括至少一个具有至少一个透射元件的芯和由涂层材料制成的至少一个涂层,其中所述涂料至少具有密度不高于0.940g / cm 3的第一聚乙烯,优选不低于 0.910g / cm 3,更优选0.915g / cm 3至0.938g / cm 3,以及根据ASTM D1238-00标准,在190℃,2.16Kg负荷下测量的熔体流动指数(MFI)为0.05g / 10'至2g / 10',优选0.1g / 10'至1g / 10'; 所述第一聚乙烯是从废料获得的; 至少第二聚乙烯的密度高于0.940g / cm3,优选不高于0.970g / cm3,更优选为0.942g / cm3至0.965g / cm3。 优选地,涂层是具有保护功能的电缆外层。
摘要:
A method for monitoring deformations in a tyre of a vehicle wheel, the wheel including the tyre and a rim, the method including: providing the wheel with at least two magnetic-field emitters mutually disposed so as to yield a composite magnetic field having one or more space portions where at least one component of the composite magnetic field is substantially null; disposing at least one main magnetic-field sensor substantially in one of the one or more space portions; monitoring variation of the at least one component of the composite magnetic field; and correlating the variation with tyre deformations. At least one of the magnetic-field emitters is disposed in contact with the tyre. A system for monitoring deformations in a tyre of a vehicle wheel includes the wheel, the at least two magnetic-field emitters, and the at least one main magnetic-field sensor.
摘要:
A polymeric surfactant obtained by the reaction of: (i) a polyolefin oligomer functionalized with at least one group deriving from a dicarboxylic acid, or a derivative thereof; and (ii) a polyoxyalkylene of linear oxyalkylene units. The polyoxyalkylene is linked to a long-chain alkyl group optionally containing one or more ethylenic unsaturations. The polymeric surfactant may be utilized to stabilize a fuel of an emulsion between water and a liquid hydrocarbon. The fuel has high stability over time, without forming carbonaceous deposits which adhere to metal surfaces.
摘要:
A cable includes at least one conductor and at least one covering layer. The at least one covering layer includes a thermoplastic polymer material. The polymer material includes a propylene homopolymer or a copolymer of propylene with an olefin comonomer. The olefin comonomer is ethylene, one or more α-olefins other than propylene, or ethylene and one or more α-olefins other than propylene. The homopolymer or copolymer has a melting point between 140° C. and 165° C., a melting enthalpy between 30 J/g and 80 J/g, a boiling diethyl ether soluble fraction less than or equal to 12 wt % and melting enthalpy less than or equal to 4 J/g, a boiling n-heptane soluble fraction between 15 wt % and 60 wt % and melting enthalpy between 10 J/g and 40 J/g, and a boiling n-heptane insoluble fraction between 40 wt % and 8 wt % and melting enthalpy greater than or equal to 45 J/g.
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:
Supported catalysts for the polymerization of olefins comprise the following components: (A) a porous organic support functionalised with groups having active hydrogen atoms; (B) an organo-metallic compound of aluminium containing heteroatoms selected from oxygen, nitrogen and sulphur; and (C) a compound of a transition metal selected from those of groups IVb, Vb or VIb of the Periodic Table of the Elements, containing ligands of the cyclopentadienyl type. These supported catalysts, obtainable in the form of spherical particles, can be used in the polymerization reaction of olefins either in liquid or in gas phase, thus producing polymers endowed with a controlled morphology and with a high bulk density.
摘要:
A cable, in particular for power transmission, for telecommunications or for data transmission, or also combined power/telecommunications cables, wherein at least one coating layer is comprised of a recyclable material which is halogen-free and has superior mechanical and electrical properties. This material comprises a polymer mixture of a crystalline propylene homopolymer or copolymer and an elastomeric copolymer of ethylene with at least one alpha-olefin having from 3 to 12 carbon atoms, and optionally containing a diene. The copolymer is characterized by a 200% tension set value of lower than 30% (measured at 20° C. for 1 minute according to ASTM standard D 412). The cable also includes a flame-retardant polymer composition.
摘要:
The present invention relates to a solid catalyst component for the polymerization of olefins CH.sub.2 .dbd.CHR in which R is hydrogen or a hydrocarbyl radical with 1-12 carbon atoms, comprising a titanium compound, having at least a Ti-halogen bond and an electron donor compound supported on a Mg halide, in which said electron donor compound is selected from esters of malonic acids of formula (I): ##STR1## wherein R.sub.1 is a C.sub.5 -C.sub.20 linear or branched alkyl, a C.sub.5 -C.sub.20 cycloalkyl, a C.sub.7 -C.sub.20 arylalkyl or alkylaryl group; R.sub.2 and R.sub.3, equal to or different from each other, are C.sub.1 -C.sub.3 alkyl, cycloalkyl. Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give high yields and polymers having high insolubility in xylene.
摘要:
Process for the preparation of a solid catalyst component for olefins polymerization including (1) a magnesium halide in active form, (2) a titanium compound, and (3) an electron-donor compound selected from particular 1,3-diethers, the process being carried out by reaction between the compounds from (1) to (3), and including at least two additions of electron-donor (3) in the following order: a) one addition prior to or during a reaction with the titanium compound or with a halogenated compound, and then b) one addition prior to or during a further reaction with the titanium compound.
摘要:
Crystalline propylene polymers having P.I. values lower than or equal to 3.7, and having, at an MFR (Melt Flow Rate) ranging from 600 to 1000 g/10 min., an Mw value from 100,000 to 60,000, and at a MFR ranging from 1000 to 2000 g/10 min., an Mz value higher than or equal to 140,000, are obtained by way of polymerization with specific supported catalysts.