To provide a glass composition for glass fiber having a low dielectric loss tangent, suppressing the occurrence of phase separation, having a reduced viscosity at high temperatures, and reducing the occurrence of striae. The glass composition for glass fiber includes 52.0 to 57.5% by mass of SiO.sub.2, 19.5 to 25.5% by mass of B.sub.2O.sub.3, 8.0 to 13.0% by mass of Al.sub.2O.sub.3, 0 to 2.0% by mass of MgO, 0 to 6.0% by mass of CaO, 0.5 to 6.5% by mass of SrO, and 0.1 to 3.0% by mass of TiO.sub.2, the ratio of Al.sub.2O.sub.3 to B.sub.2O.sub.3 is 0.35 to 0.54, and the content SI of SiO.sub.2, the content B of B.sub.2O.sub.3, the content M of MgO, the content C of CaO, the content SR of SrO, and the content T of TiO.sub.2 satisfy the following formula (1): 6.90≤100×(B/SI).sup.2×{SR/(C+SR)}.sup.2/3×{T/(M+T)}.sup.1/2≤12.30 (1).

An optical fiber comprises a glass fiber comprising a core and a cladding, a primary resin layer being in contact with the glass fiber and covering the glass fiber, and a secondary resin layer covering the primary resin layer, wherein the secondary resin layer consists of a cured product of a resin composition comprising a base resin containing a urethane (meth)acrylate oligomer, a monomer, and a photopolymerization initiator and hydrophobic inorganic oxide particles, the content of the inorganic oxide particles is 1% by mass or more and 60% by mass or less based on the total amount of the resin composition, and the glass transition temperature of the secondary resin layer is 60° C. or more and 120° C. or less.

An optical fiber comprises a glass fiber comprising a core and a cladding, a primary resin layer being in contact with the glass fiber and covering the glass fiber, and a secondary resin layer covering the primary resin layer, wherein the secondary resin layer consists of a cured product of a resin composition comprising a base resin containing a urethane (meth)acrylate oligomer, a monomer, and a photopolymerization initiator and hydrophobic inorganic oxide particles, the content of the inorganic oxide particles is 1% by mass or more and 60% by mass or less based on the total amount of the resin composition, and the glass transition temperature of the secondary resin layer is 60° C. or more and 120° C. or less.

A resin composition for secondary coating of an optical fiber is a resin composition comprising: a non-reactive urethane compound having a number average molecular weight of 10000 or more and 40000 or less, a photopolymerizable compound, and a photopolymerization initiator, wherein the content of the non-reactive urethane compound is 0.05 parts by mass or more and 10 parts by mass or less based on the total amount of the resin composition of 100 parts by mass, and the non-reactive urethane compound is a reaction product of a polyol having a number average molecular weight of 1800 or more and 4500 or less, a diisocyanate, and a compound having active hydrogen.

A resin composition for secondary coating of an optical fiber is a resin composition comprising: a non-reactive urethane compound having a number average molecular weight of 10000 or more and 40000 or less, a photopolymerizable compound, and a photopolymerization initiator, wherein the content of the non-reactive urethane compound is 0.05 parts by mass or more and 10 parts by mass or less based on the total amount of the resin composition of 100 parts by mass, and the non-reactive urethane compound is a reaction product of a polyol having a number average molecular weight of 1800 or more and 4500 or less, a diisocyanate, and a compound having active hydrogen.

Crosslinkable polymeric compositions comprising an ethylene-based polymer, an organic peroxide, and an amine-functionalized interpolymer. Such crosslinkable polymeric compositions and their crosslinked forms can be employed as polymeric layers in wire and cable applications, such as insulation in power cables.

Crosslinkable polymeric compositions comprising an ethylene-based polymer, an organic peroxide, and an amine-functionalized interpolymer. Such crosslinkable polymeric compositions and their crosslinked forms can be employed as polymeric layers in wire and cable applications, such as insulation in power cables.

A resin composition for the secondary coating of an optical fiber is a resin composition containing a non-reactive urethane compound having a number average molecular weight of 10000 or more and 50000 or less, a photopolymerizable compound, and a photopolymerization initiator, the content of the non-reactive urethane compound is 0.05 parts by mass or more and 5 parts by mass or less based on the total amount of the resin composition, and the non-reactive urethane compound is a reaction product of a polyol having a number average molecular weight of 8000 or more and 20000 or less, a diisocyanate, and a compound having active hydrogen.

A resin composition for the secondary coating of an optical fiber is a resin composition containing a non-reactive urethane compound having a number average molecular weight of 10000 or more and 50000 or less, a photopolymerizable compound, and a photopolymerization initiator, the content of the non-reactive urethane compound is 0.05 parts by mass or more and 5 parts by mass or less based on the total amount of the resin composition, and the non-reactive urethane compound is a reaction product of a polyol having a number average molecular weight of 8000 or more and 20000 or less, a diisocyanate, and a compound having active hydrogen.

Mineral wool insulation products are provided. The mineral wool insulation includes a plurality of mineral wool fibers and a wax emulsion applied to the mineral wool fibers. The wax emulsion imparts excellent water resistance and thermal performance properties to the mineral wool insulation.