Coated optical fibers

Primary coating composition when cured having an equilibrium modulus of 1.2 MPa or less, a storage modulus at 23° C. (E′23) and a cavitation strength at which a tenth cavitation appears (σ10cav) of at least about 1.0 MPa as measured at a deformation rate of 0.20% min−1, said cavitation strength being at least about 1.4 times said storage modulus at 23° C., wherein said primary coating composition comprises:

• (a) 20–98% by wt, relative to the total weight of components (a) through (d), of at least two oligomers at least one of said oligomers having an average molecular weight that is at least twice the average molecular weight of another of said at least two oligomers, at least one oligomer having a number average molecular weight of about 1000 or higher;
• (b) 0–80% by wt, relative to the total weight of components (a) through (d), of one or more reactive diluents;
• (c) 0.1–20% by wt, relative to the total weight of components (a) through (d), of one or more photoinitiators for initiation of a radical polymerization reaction;
• and
• (d) optionally, one or more additives selected from the group consisting of amines, antioxidants, UV absorbers, light stabilizers, silane coupling agents, coating surface improvers, heat polymerization inhibitors, leveling agents, surfactants, colorants, preservatives, plasticizers, lubricants, solvents, fillers, aging preventives, and wettability improvers.

Method for curing a primary coating composition comprising the steps of

• (i) preparing said primary coating composition, which when cured without preflash has an equilibrium modulus of 1.2 MPa or less and a cavitation strength at which a tenth cavitation appears (σ10cav) of at least about 0.9 MPa as measured at a deformation rate of 0.20% min−1, said cavitation strength being about 1.0 times or less of its storage modulus at 23° C. (E′23), and
• (ii) curing said composition with a first dose comprising at least one flash of UV-light of a total energy between about 5 and 50 mJ/cm2, and
• (iii) subsequently curing the pre-cured coating with such a second UV-dose that the pre-cured coating attains at least 85% of its maximum attainable equilibrium modulus;
• wherein said primary coating composition comprises
• (a) 20–98% by wt, relative to the total weight of components (a) through (d), of at least one oligomer having a number average molecular weight of about 1000 or higher;
• (b) 0–80% by wt, relative to the total weight of components (a) through (d), of one or more reactive diluents;
• (c) 0.1–20% by wt, relative to the total weight of components (a) through (d), of one or more photoinitiators for initiation of a radical polymerization reaction;
• and
• (d) optionally, additives.

A coated optical fiber comprising a glass optical fiber, a primary coating applied thereon, a secondary coating, and optionally an ink composition subsequently applied thereon,

• wherein said primary coating is obtained by curing a primary coating composition comprising:
• (a) 20–98% by wt, relative to the total weight of components (a) through (d), of at least two oligomers at least one of said oligomers having an average molecular weight that is at least twice the average molecular weight of another of said at least two oligomers, at least one oligomer having a number average molecular weight of about 1000 or higher;
• (b) 0–80% by wt, relative to the total weight of components (a) through (d), of one or more reactive diluents;
• (c) 0.1–20% by wt, relative to the total weight of components (a) through (d), of one or more photoinitiators for initiation of a radical polymerization reaction;
• wherein the primary coating has a storage modulus at 23° C. (E′23), has an equilibrium modulus of 1.2 MPa or less, and a cavitation strength at which a tenth cavitation appears (σ10cav) of at least about 1.0 MPa as measured at a deformation rate of 0.20% min−1, said cavitation strength being at least about 1.4 times said storage modulus at 230C.

A coated optical fiber comprising a glass optical fiber, a primary coating applied thereon, a secondary coating, and optionally an ink composition subsequently applied thereon,

• wherein said primary coating is obtained by curing a primary coating composition comprising:
• (a) 20–98% by wt, relative to the total weight of components (a) through (d), of at least one oligomer having a number average molecular weight of about 1000 or higher;
• (b) 5–80% by wt, relative to the total weight of components (a) through (d), of two or more reactive diluents, of which at least two reactive diluents are di- or multifunctional;
• (c) 0.1–20% by wt, relative to the total weight of components (a) through (d), of one or more photoinitiators for initiation of a radical polymerization reaction;
• wherein the primary coating has a storage modulus at 23° C. (E′23), has an equilibrium modulus of 1.2 MPa or less, and a cavitation strength at which a tenth cavitation appears (σ10cav) of at least about 1.0 MPa as measured at a deformation rate of 0.20% min1, said cavitation strength being at least about 1.4 times said storage modulus at 23° C.

A coated optical fiber comprising a glass optical fiber, a primary coating applied thereon, a secondary coating, and optionally an ink composition subsequently applied thereon,

• wherein said primary coating is obtained by curing a primary coating composition comprising:
• (a) 20–98% by wt, relative to the total weight of components (a) through (d), of at least one oligomer having a number average molecular weight of about 1000 or higher;
• (b) 0–80% by wt, relative to the total weight of components (a) through (d), of one or more reactive diluents;
• (c) 0.1–20% by wt, relative to the total weight of components (a) through (d), of one or more photoinitiators for initiation of a radical polymerization reaction;
• the composition comprising at least about 1 wt. % and less than about 10 wt. % of monofunctional acrylate having a molecular weight below 500;
• wherein the primary coating has a storage modulus at 23° C. (E′23), has an equilibrium modulus of 1.2 MPa or less, and a cavitation strength at which a tenth cavitation appears (σ10cav) of at least about 1.0 MPa as measured at a deformation rate of 0.20% min−1, said cavitation strength being at least about 1.4 times said storage modulus at 23° C.

Coating system for an optical glass fiber comprising a

• (A) primary coating composition when cured having an equilibrium modulus of 1.2 MPa or less, a storage modulus at 23° C. (E′23) and a cavitation strength at which a tenth cavitation appears (σ10cav) of at least about 1.0 MPa as measured at a deformation rate of 0.20% min−1, said cavitation strength being at least about 1.4 times said storage modulus at 23° C., wherein said primary coating composition comprises:
• (a) 20–98% by wt, relative to the total weight of components (a) through (d), of at least one oligomer having a number average molecular weight of about 1000 or higher;
• (b) 0–80% by wt, relative to the total weight of components (a) through (d), of one or more reactive diluents;
• (c) 0.1–20% by wt, relative to the total weight of components (a) through (d), of one or more photoinitiators for initiation of a radical polymerization reaction;
• and
• (d) optionally, one or more additives selected from the group consisting of amines, antioxidants, UV absorbers, light stabilizers, silane coupling agents, coating surface improvers, heat polymerization inhibitors, leveling agents, surfactants, colorants, preservatives, plasticizers, lubricants, solvents, fillers, aging preventives, and wettability improvers;
• and
• (B) a secondary coating composition when cured having a volumetric thermal expansion coefficient α23 of at least about 3.15×10−4 K−1.

Primary coating composition when cured having an equilibrium modulus of 1.2 MPa or less, a storage modulus at 23° C. (E′23) and a cavitation strength at which a tenth cavitation appears (σ10cav) of at least about 1.0 MPa as measured at a deformation rate of 0.20% min−1, said cavitation strength being at least about 1.4 times said storage modulus at 23° C., wherein said primary coating composition comprises:

• (a) 20–98% by wt, relative to the total weight of components (a) through (d), of at least one oligomer having a number average molecular weight of about 1000 or higher;
• (b) 5–80% by wt, relative to the total weight of components (a) through (d), of two or more reactive diluents, of which at least two reactive dilutents are di- or multifunctional;
• (c) 0.1–20% by wt, relative to the total weight of components (a) through (d), of one or more photoinitiators for initiation of a radical polymerization reaction;
• and
• (d) optionally, one or more additives selected from the group consisting of amines, antioxidants, UV absorbers, light stabilizers, silane coupling agents, coating surface improvers, heat polymerization inhibitors, leveling agents, surfactants, colorants, preservatives, plasticizers, lubricants, solvents, fillers, aging preventives, and wettability improvers.

Primary coating composition when cured having an equilibrium modulus of 1.2 MPa or less, a storage modulus at 23° C. (E′23) and a cavitation strength at which a tenth cavitation appears (σ10cav) of at least about 1.0 MPa as measured at a deformation rate of 0.20% min−1, said cavitation strength being at least about 1.4 times said storage modulus at 23° C., wherein said primary coating composition comprises:

• (a) 20–98% by wt, relative to the total weight of components (a) through (d), of at least one oligomer having a number average molecular weight of about 1000 or higher;
• (b) 0–80% by wt, relative to the total weight of components (a) through (d), of one or more reactive diluents;
• (c) 0.1–20% by wt, relative to the total weight of components (a) through (d), of one or more photoinitiators for initiation of a radical polymerization reaction;
• (d) optionally, one or more additives selected from the group consisting of amines, antioxidants, UV absorbers, light stabilizers, silane coupling agents, coating surface improvers, heat polymerization inhibitors, leveling agents, surfactants, colorants, preservatives, plasticizers, lubricants, solvents, fillers, aging preventives, and wettability improvers;
• the composition comprising at least about 1 wt % and less than about 10 wt % of monofunctional acrylate having a molecular weight below 500.