Provided is a coated optical fiber excellent in both characteristics of the microbending loss resistance and the low-temperature characteristic. The coated optical fiber 1 comprises an optical fiber 10 that has a cladding layer composed of glass formed on an outer periphery of a glass core, a primary coating layer 20 that coats an outer periphery of the optical fiber 10, and a secondary coating layer 30 that coats an outer periphery of the primary coating layer 20, wherein the primary coating layer 20 has a Young's modulus of 1.2 MPa or less, the secondary coating layer 30 has a Young's modulus of 700 MPa or more, and the primary coating layer 20 contains tin in a content of 70 ppm or less.

Provided is a coated optical fiber excellent in both characteristics of the microbending loss resistance and the low-temperature characteristic. The coated optical fiber 1 comprises an optical fiber 10 that has a cladding layer composed of glass formed on an outer periphery of a glass core, a primary coating layer 20 that coats an outer periphery of the optical fiber 10, and a secondary coating layer 30 that coats an outer periphery of the primary coating layer 20, wherein the primary coating layer 20 has a Young's modulus of 1.2 MPa or less, the secondary coating layer 30 has a Young's modulus of 700 MPa or more, and the primary coating layer 20 contains tin in a content of 70 ppm or less.

A coated optical fiber, including a coating layer with a high elastic modulus even when a glass optical fiber is coated with resin by using an ultraviolet semiconductor light emitting element as a light source for curing resin and using a Wet-on-Wet method, is provided. A manufacturing method of the coated optical fiber includes: applying a first ultraviolet curable resin to a glass optical fiber; applying a second ultraviolet curable resin to the periphery of the first ultraviolet curable resin before curing the first ultraviolet curable resin; and irradiating the first and second ultraviolet curable resins with light in a wavelength range of 350 to 405 nm emitted from an ultraviolet semiconductor light emitting element, wherein the second ultraviolet curable resin contains a photopolymerization initiator that absorbs the light from the ultraviolet semiconductor light emitting element to generate radicals, and the photopolymerization initiator has photobleaching properties.

A resin composition for primary coating of the optical fiber according to the present disclosure is a resin composition containing a photopolymerizable compound, a photopolymerizable initiator, and a polymerization inhibitor, wherein the photopolymerizable compound contains a photopolymerizable compound having a urethane bond and a photopolymerizable compound not having a urethane bond, the polymerization inhibitor contains 4-methoxyphenol, and the total content of the polymerization inhibitor is 200 ppm or more and 800 ppm or less.

A resin composition for primary coating of the optical fiber according to the present disclosure is a resin composition containing a photopolymerizable compound, a photopolymerizable initiator, and a polymerization inhibitor, wherein the photopolymerizable compound contains a photopolymerizable compound having a urethane bond and a photopolymerizable compound not having a urethane bond, the polymerization inhibitor contains 4-methoxyphenol, and the total content of the polymerization inhibitor is 200 ppm or more and 800 ppm or less.

The present invention provides a two-layer structure colored optical fiber which includes a colored secondary coating layer improved in collectability and separability. The two-layer structure colored optical fiber in an embodiment of the present invention includes a glass optical fiber, a primary coating layer coating the glass optical fiber, and a colored secondary coating layer coating the primary coating layer. The secondary coating layer has such characteristics that a surface cure percentage is 99% or more at an infrared absorption peak of a wave number of 1407 cm.sup.1 and a surface kinetic friction force in Knot Test is less than 0.075 N.

A curable formaldehyde-free binding composition for use with fiberglass is provided. Such curable composition comprises an aldehyde or ketone and an amine salt of an inorganic acid. The composition when applied to fiberglass is cured to form a water-insoluble binder which exhibits good adhesion to glass. In a preferred embodiment the composition when applied to fiberglass provides a sufficient blackness required in facer products.

A curable formaldehyde-free binding composition for use with fiberglass is provided. Such curable composition comprises an aldehyde or ketone and an amine salt of an inorganic acid. The composition when applied to fiberglass is cured to form a water-insoluble binder which exhibits good adhesion to glass. In a preferred embodiment the composition when applied to fiberglass provides a sufficient blackness required in facer products.

The invention relates to a process for the preparation of a shaped composite, comprising the preparation of a mixture into which fragments of mineral wool comprising a size comprising a sugar, a non-cement silica carrier distinct from the wool, a non-cement alkali metal carrier distinct from the wool, and water, are introduced, the non-cement silica carrier and the non-cement alkali metal carrier forming, with the water, a mineral binder which gradually solidifies around the solid particles present in the mixture, and then the shaping of the mixture into a shaped composite, in particular into briquettes. The invention also relates to a process for the manufacture of mineral wool, in which a molten mass is produced which is converted into mineral wool by means of a fiberizing device, the shaped composite being introduced as vitrifiable charge into a melting chamber, such as a cupola furnace.

The present invention provides a two-layer structure colored optical fiber which includes a colored secondary coating layer improved in collectability and separability. The two-layer structure colored optical fiber in an embodiment of the present invention includes a glass optical fiber, a primary coating layer coating the glass optical fiber, and a colored secondary coating layer coating the primary coating layer. The secondary coating layer has such characteristics that a surface cure percentage is 99% or more at an infrared absorption peak of a wave number of 1407 cm.sup.1 and a surface kinetic friction force in Knot Test is less than 0.075 N.