A tire whose tread consists totally or partly of a rubber composition which comprises at least 80 phr of a copolymer of ethylene and of a 1,3-diene which contains at least 70 mol % of ethylene units, between 25 phr and 55 phr of a carbon black, less than 1 phr of sulfur and a vulcanization accelerator is provided. The carbon black representing more than 60% by mass of the reinforcing filler of the rubber composition, the mass ratio between the sulfur content and the amount of vulcanization accelerator in the rubber composition being less than 1. The vulcanization accelerator is a primary accelerator or a mixture of a primary accelerator and of a secondary accelerator. Such a composition has good cohesion properties.

A polyolefin composition is described which comprises poly-(alpha-olefin) and 10 to 45% by weight, based on the total weight of the composition, of cycloolefin polymer having a glass transition temperature of at least 30° C. This polyolefin composition has domains of cycloolefin polymer in a matrix of poly-(alpha-olefin) in the form of plates.

These polyolefin compositions and the moulded articles made therefrom exhibit excellent barrier properties to gases and vapors and excellent dielectric properties.

A polyolefin composition is described which comprises poly-(alpha-olefin) and 10 to 45% by weight, based on the total weight of the composition, of cycloolefin polymer having a glass transition temperature of at least 30° C. This polyolefin composition has domains of cycloolefin polymer in a matrix of poly-(alpha-olefin) in the form of plates.

These polyolefin compositions and the moulded articles made therefrom exhibit excellent barrier properties to gases and vapors and excellent dielectric properties.

The copolymerization of ethylene with a cyclic mono olefin (such as norbornene) is conducted in the presence of a catalyst system comprising a bridged hafnocene catalyst and a three part activator. The catalyst system provides excellent activity at high polymerization temperatures. Copolymers produced according to this invention have unique microstructure (with methyl branching being observed) and unique rheology.

A polymer optical fibre (POF) (30) for transmitting light of wavelength, λi, between two separate elements of an active implantable medical device (AIMD), includes a core (31) which is cylindrical and made of a cyclic olefin polymer (COP) or copolymer (COC), having a core refractive index at the wavelength, λi, n_core, A cladding (32) which has a cladding refractive index at the wavelength, λi, n_clad<n_core, and which is made of a cladding copolymer including monomers of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride. The cladding being itself enclosed in a coating (33) which is made of a coating polymer formed of one of the monomers of the cladding copolymer. The POF has a numerical aperture, NA, at the wavelength, λi, of at least 0.5.

A polymer optical fibre (POF) (30) for transmitting light of wavelength, λi, between two separate elements of an active implantable medical device (AIMD), includes a core (31) which is cylindrical and made of a cyclic olefin polymer (COP) or copolymer (COC), having a core refractive index at the wavelength, λi, n_core, A cladding (32) which has a cladding refractive index at the wavelength, λi, n_clad<n_core, and which is made of a cladding copolymer including monomers of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride. The cladding being itself enclosed in a coating (33) which is made of a coating polymer formed of one of the monomers of the cladding copolymer. The POF has a numerical aperture, NA, at the wavelength, λi, of at least 0.5.

A resin composition of the present invention contains an ethylene-cyclic olefin copolymer (A) that includes repeating units including ethylene units and norbornene units having a substituent R.sup.1 and is represented by Formula (I) below, and a transition metal catalyst (B). In the formula, R.sup.1 represents an ethylene group or an ethylene group that is subjected to substitution with an aliphatic hydrocarbon group having 1 to 3 carbon atoms, l and n represent the content ratios of the ethylene units and the norbornene units having a substituent R.sup.1, respectively, and the ratio of l to n (l/n) is 4 or more and 2,000 or less.

##STR00001##

A resin composition of the present invention contains an ethylene-cyclic olefin copolymer (A) that includes repeating units including ethylene units and norbornene units having a substituent R.sup.1 and is represented by Formula (I) below, and a transition metal catalyst (B). In the formula, R.sup.1 represents an ethylene group or an ethylene group that is subjected to substitution with an aliphatic hydrocarbon group having 1 to 3 carbon atoms, l and n represent the content ratios of the ethylene units and the norbornene units having a substituent R.sup.1, respectively, and the ratio of l to n (l/n) is 4 or more and 2,000 or less.

##STR00001##

To provide a resin composition comprising a cyclic polyolefin and an ethylene polymer, having excellent impact resistance and having high transparency maintained. A resin composition comprising from 5 to 95 parts by weight of a cyclic polyolefin (A) and from 5 to 95 parts by weight of an ethylene polymer (B) which satisfies the following requirements (a) to (d) (the total amount of (A) and (B) is 100 parts by weight): (a) the density is from 930 to 960 kg/m.sup.3; (b) MFR is from 0.1 to 15.0 g/10 min; (c) in molecular weight measurement by gel permeation chromatography, two peaks are observed, and the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is within a range of from 3.0 to 7.0; and (d) a fraction having Mn of at least 100,000 as obtained by molecular weight fractionation, has at least 0.15 long-chain branches per 1,000 carbon atoms of the main chain.

To provide a resin composition comprising a cyclic polyolefin and an ethylene polymer, having excellent impact resistance and having high transparency maintained. A resin composition comprising from 5 to 95 parts by weight of a cyclic polyolefin (A) and from 5 to 95 parts by weight of an ethylene polymer (B) which satisfies the following requirements (a) to (d) (the total amount of (A) and (B) is 100 parts by weight): (a) the density is from 930 to 960 kg/m.sup.3; (b) MFR is from 0.1 to 15.0 g/10 min; (c) in molecular weight measurement by gel permeation chromatography, two peaks are observed, and the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is within a range of from 3.0 to 7.0; and (d) a fraction having Mn of at least 100,000 as obtained by molecular weight fractionation, has at least 0.15 long-chain branches per 1,000 carbon atoms of the main chain.