Abstract: The present invention concerns an optical fibre comprising: an optical waveguide comprising a glass core surrounded by a glass cladding; a coating surrounding said optical waveguide comprising a cured polymer material comprising a polyester obtained by esterification of: a reactant A selected from an acid, a triglyceride, or a mixture of triglycerides having a C16-C24 aliphatic chain comprising at least two conjugated double bonds; and a polyol made of at least one monomer comprising at least 3 hydroxyl groups, the polyol being thermally stable up to 300° C. (reactant B). The present invention concerns also the above said polyester coating, a method for coating an optical fibre with said polyester coating and a method for obtaining predetermined mechanical properties of a coating for an optical fibre. The cured polymer forming the coating can be prepared by curing the polyester of the invention either thermally or by radiation.

Abstract: An optical fibre comprising: an optical waveguide comprising a glass core surrounded by a glass cladding; a coating surrounding said optical waveguide comprising a polymer material comprising a cured polyester obtained by: (a) esterification of a reactant (A) selected from carboxylic acids, triglycerides, and mixtures thereof, having a C16-C24 aliphatic chain comprising at least two conjugated double bonds, with a reactant (B) selected from polyols having at least 3 hydroxyl groups, the polyols being thermally stable up to 300° C.; (b) curing of the 10 so obtained polyester, in the presence of a transition metal salt, the transition metal being selected from Mn, Fe, Co, Cu, and Ni. Preferably, the step of curing is a thermal curing, preferably up to 300° C. The transition metal salt acts as curing accelerator, i.e.

Abstract: An optical fibre comprising: an optical waveguide comprising a glass core surrounded by a glass cladding; a primary coating surrounding the optical waveguide; a secondary coating, surrounding the primary coating, comprising a cured polymer material obtained by curing a curable coating composition comprising: (a) a polyester obtained by esterification of a reactant A selected from carboxylic acids, triglycerides, and mixtures thereof, having a C16-C24 aliphatic chain comprising at least two double bonds spaced by one carbon atom at most, with a reactant B selected from polyols having at least 3 hydroxyl groups, the polyols being thermally stable up to 300° C.; (b) an aromatic glycidyl epoxy resin; (c) an aliphatic polyether hardener containing from 8 to 64 hydroxy groups and/or from 2 to 4 epoxy groups; and (d) a secondary amine compound as curing agent. Preferably, the step of curing is a thermal curing, preferably up to 300° C.

Abstract: An optical fibre comprising: an optical waveguide comprising a core surrounded by a cladding; a primary coating surrounding the optical waveguide; and a coating, surrounding the primary coating, comprising a polymer material obtained by radiation curing a polymerizable composition, the polymer material having a degree of crystallinity of at most 12. The coating of the optical fiber according to the present invention exhibits enhanced resistance upon exposure to high temperature, preferably a temperature over 250° C., while endowed with required features such as protective capability, elasticity, adhesion to underlying layer and simple manufacturing.

Abstract: An optical fibre comprising: an optical waveguide comprising a glass core surrounded by a glass cladding; a primary coating surrounding the optical waveguide; a secondary coating, surrounding the primary coating, comprising a cured polymer material obtained by curing a curable coating composition comprising: (a) a polyester obtained by esterification of a reactant A selected from carboxylic acids, triglycerides, and mixtures thereof, having a C16-C24 aliphatic chain comprising at least two double bonds spaced by one carbon atom at most, with a reactant B selected from polyols having at least 3 hydroxyl groups, the polyols being thermally stable up to 300° C.; (b) an aromatic glycidyl epoxy resin; (c) an aliphatic polyether hardener containing from 8 to 64 hydroxy groups and/or from 2 to 4 epoxy groups; and (d) a secondary amine compound as curing agent. Preferably, the step of curing is a thermal curing, preferably up to 300° C.

Abstract: The present invention concerns an optical fibre comprising: an optical waveguide comprising a glass core surrounded by a glass cladding; a coating surrounding said optical waveguide comprising a cured polymer material comprising a polyester obtained by esterification of: a reactant A selected from an acid, a triglyceride, or a mixture of triglycerides having a C16-C24 aliphatic chain comprising at least two conjugated double bonds; and a polyol made of at least one monomer comprising at least 3 hydroxyl groups, the polyol being thermally stable up to 300° C. (reactant B). The present invention concerns also the above said polyester coating, a method for coating an optical fibre with said polyester coating and a method for obtaining predetermined mechanical properties of a coating for an optical fibre. The cured polymer forming the coating can be prepared by curing the polyester of the invention either thermally or by radiation.

Abstract: The present invention concerns an optical fibre comprising: an optical waveguide comprising a glass core surrounded by a glass cladding; a coating surrounding said optical waveguide comprising a cured polymer material comprising a polyester obtained by polymerization of a monomer selected from an acid, a triglyceride, or a mixture of triglycerides having a C16-C24 aliphatic chain comprising at least two conjugated double bonds. The present invention concerns also a method for coating an optical fibre with said polyester coating. The cured polymer material forming the coating can be prepared by curing the polyester of the invention either thermally or by radiation.

Abstract: A power cable having a metallic electrical conductor surrounded by one or more semiconductive layer and more or more insulating layer, wherein the cable has at least one metallic element made of aluminum, having a corrosion inhibitor provided in direct contact with the at least one metallic element made of aluminum.

Abstract: An optical fibre comprising: an optical waveguide comprising a core surrounded by a cladding; a primary coating surrounding the optical waveguide; and a coating, surrounding the primary coating, comprising a polymer material obtained by radiation curing a polymerizable composition, the polymer material having a degree of crystallinity of at most 12. The coating of the optical fiber according to the present invention exhibits enhanced resistance upon exposure to high temperature, preferably a temperature over 250° C., while endowed with required features such as protective capability, elasticity, adhesion to underlying layer and simple manufacturing.

Abstract: The present invention relates to a power cable comprising a metallic electric conductor surrounded by one or more semiconductive layer and one or more insulating layer, said cable having at least one metallic element made of aluminium, wherein a corrosion inhibitor is provided in direct contact with said at least one metallic element made of aluminium, and wherein said corrosion inhibitor is a corrosion inhibitor of formula (I).

Abstract: A method of manufacturing an optical fiber preform includes: producing a core rod having a core rod diameter; inserting the core rod into a glass fluorine-doped intermediate cladding tube so as to form a core assembly, the intermediate cladding tube having an inner diameter and an outer diameter, wherein the inner diameter is larger than the core rod diameter, the radial difference between the inner diameter and the core rod diameter defining an annular gap; and applying a negative pressure inside the annular gap; and forming a core preform by heating the core assembly to collapse the intermediate cladding tube around the core rod while maintaining the negative pressure, wherein heating includes moving a heater outside the intermediate cladding tube and along an axial direction of the same, and forming an overcladding region surrounding the core preform so as to form an optical fiber preform.

Abstract: A single-mode transmission optical fiber includes a central core region radially outwardly from a centerline to a radius r1 and having a positive relative refractive index ?1; a first inner cladding region extending radially outwardly from the central core to a radius r2 and having a negative relative refractive index ?2; a second inner cladding region extending radially outwardly from the first inner cladding region to a radius r3 and having a non-negative relative refractive index ?3; an intermediate cladding region extending radially outwardly from the second inner cladding region to a radius r4 having a negative relative refractive index ?4 larger in absolute value than the relative refractive index ?2; and an outer cladding region extending radially outwardly from the intermediate cladding region and having a non-negative relative refractive index ?5; wherein the relative refractive index ?2 of the first inner cladding region is ?0.1·10?3 to ?1.

Abstract: A method of coloring optical fibers during the optical fiber drawing that includes the steps of feeding a natural fiber coating material and a colorant to a mixer; mixing the natural fiber coating material and the colorant in the mixer to obtain a colored coating material; and supplying the colored coating material to a coating die. The feeding step includes exerting on the natural fiber coating a first gas pressure variable with at least one fiber drawing parameter; and exerting on the colorant a second gas pressure variable with at least one fiber drawing parameter.

Abstract: An optical fiber includes a glass core and a protective coating consisting of a single coating layer disposed to surround the glass core, wherein the single coating layer is formed from a cured polymeric material obtained by curing a radiation curable composition including: (i) a radiation curable urethane (meth)acrylate oligomer, preferably including a backbone derived from polyoxytetramethylene glycol, (ii) at least one monofunctional reactive monomer, (iii) at least one multifunctional reactive monomer, and (iv) an adhesion promoter.

Abstract: A method of coloring optical fibers during the optical fiber drawing that includes the steps of feeding a natural fiber coating material and a colorant to a mixer; mixing the natural fiber coating material and the colorant in the mixer to obtain a colored coating material; and supplying the colored coating material to a coating die. The feeding step includes exerting on the natural fiber coating a first gas pressure variable with at least one fiber drawing parameter; and exerting on the colorant a second gas pressure variable with at least one fiber drawing parameter.

Abstract: An optical fiber includes an optical waveguide, a first coating layer disposed to surround the optical waveguide and a second coating layer disposed to surround the first coating layer, wherein the first coating layer is formed by a cured polymeric material obtained by curing a radiation curable composition including at least one (meth)acrylate monomer esterified with at least one branched alcohol having from 9 to 12 carbon atoms, and the second coating layer is formed by a cured polymeric material obtained by curing a radiation curable (meth)acrylate composition including from 0.8% to 1.5% by weight of silica, based on the total weight of the composition.

Abstract: The present invention relates to a radiation curable coating composition comprising a radiation curable oligomer comprising a backbone derived from polypropylene glycol and a dimer acid based polyester polyol, wherein said coating composition, when cured, is having: a) a hardening temperature (Th) of from ?10° C. to about ?20° C. and a modulus measured at said Th of lower than 5.0 MPa; or b) a hardening temperature (Th) of from ?20° C. to about ?30° C. and a modulus measured at said Th of lower than 20.0 MPa; or c) a hardening temperature (Th) of lower than about ?30° C. and a modulus measured at said Th of lower than 70.0 MPa.

Abstract: An apparatus for coloring optical fibers, includes: a first reservoir for containing a natural coating material to be applied onto an optical fiber being drawn; a second reservoir for containing a colorant to be mixed with the natural coating material; a mixer in fluid communication with the first and second reservoirs to receive a first flow of natural coating material and a second flow of colorant and to mix the first and second flows to obtain a colored coating material; a coating die in fluid communication with the mixer to receive the flow of colored coating material and to apply it onto the optical fiber being drawn.

Abstract: A method of manufacturing an optical fibre preform includes: producing a core rod having a core rod diameter; inserting the core rod into a glass fluorine-doped intermediate cladding tube so as to form a core assembly, the intermediate cladding tube having an inner diameter and an outer diameter, wherein the inner diameter is larger than the core rod diameter, the radial difference between the inner diameter and the core rod diameter defining an annular gap; and applying a negative pressure inside the annular gap; and forming a core preform by heating the core assembly to collapse the intermediate cladding tube around the core rod while maintaining the negative pressure, wherein heating includes moving a heater outside the intermediate cladding tube and along an axial direction of the same, and forming an overcladding region surrounding the core preform so as to form an optical fibre preform.

Abstract: A single-mode transmission optical fibre includes a central core region radially outwardly from a centerline to a radius r1 and having a positive relative refractive index ?1; a first inner cladding region extending radially outwardly from the central core to a radius r2 and having a negative relative refractive index ?2; a second inner cladding region extending radially outwardly from the first inner cladding region to a radius r3 and having a non-negative relative refractive index ?3; an intermediate cladding region extending radially outwardly from the second inner cladding region to a radius r4 having a negative relative refractive index ?4 larger in absolute value than the relative refractive index ?2; and an outer cladding region extending radially outwardly from the intermediate cladding region and having a non-negative relative refractive index ?5; wherein the relative refractive index ?2 of the first inner cladding region is ?0.1·10?3 to ?1.