The present disclosure relates to a glass cloth, prepreg, and printed circuit board.

There is provided a glass cloth including woven glass yarns each containing a plurality of filaments, wherein a bulk dissipation factor of a glass in the glass yarns is 0.0010 or less, a tensile strength of warp yarns per thickness of the glass cloth as represented by the following formula (A) is in the range of 0.50 to 6.0:

warp direction tensile strength (N/25 mm) of the glass cloth/thickness of the glass cloth (m)(A) a coefficient of variation of the warp direction tensile strength of the glass cloth is in the range of 15% or less, and a dissipation factor of the glass cloth at 10 GHz is in the range of greater than 0 and 0.0010 or less.

A fibre optic cable (500, 700, 1420) comprises one or more fibre units (502, 1302). Each fibre unit comprises two or more optical fibres (506, 1306) embedded in a solid resin material (520, 1320) to form a coated fibre bundle and an extruded polymer sheath (524, 1324). The sheath (524, 1324) of each fibre unit is primarily polybutylene terephthalate (PBT), with a friction reducing additive such as polydimethylsiloxane (PDMS). The additive may be polythene based and/or polyacrylate based. The fibre unit may be applied in a pullback cable (500, 800, 1100), as a cable for pulling or pushing or as a blown fibre cable (502, 1302).

A fibre optic cable (500, 700, 1420) comprises one or more fibre units (502, 1302). Each fibre unit comprises two or more optical fibres (506, 1306) embedded in a solid resin material (520, 1320) to form a coated fibre bundle and an extruded polymer sheath (524, 1324). The sheath (524, 1324) of each fibre unit is primarily polybutylene terephthalate (PBT), with a friction reducing additive such as polydimethylsiloxane (PDMS). The additive may be polythene based and/or polyacrylate based. The fibre unit may be applied in a pullback cable (500, 800, 1100), as a cable for pulling or pushing or as a blown fibre cable (502, 1302).

The present disclosure relates to silicone-coated mineral wool insulation materials, methods for making them using specific coating methods, and methods for using them. One aspect of the disclosure is a method for making a silicone-coated mineral wool, the method comprising: providing a mineral wool comprising a collection of mineral wool fibers; applying to the mineral wool a solvent-borne coating composition comprising a silicone, the silicone of the coating composition having a number-average molecular weight of at least 25 kDa; and allowing the solvent to evaporate to provide silicone-coated mineral wool.

The present disclosure relates to silicone-coated mineral wool insulation materials, methods for making them using specific coating methods, and methods for using them. One aspect of the disclosure is a method for making a silicone-coated mineral wool, the method comprising: providing a mineral wool comprising a collection of mineral wool fibers; applying to the mineral wool a solvent-borne coating composition comprising a silicone, the silicone of the coating composition having a number-average molecular weight of at least 25 kDa; and allowing the solvent to evaporate to provide silicone-coated mineral wool.

A curable aqueous composition is disclosed comprising a carbohydrate, a crosslinking agent, and an amine base, wherein the curable aqueous composition has a pH adjusted by the amine base. Further disclosed is a method of forming a curable aqueous solution.

A porous body including an inorganic fiber and an organic binder, wherein the average fiber diameter of the inorganic fiber is 2.0 μm or less, the amount of the inorganic fiber is 90% by mass or more, the amount of the organic binder is 0.5% by mass or more and 10% by mass or less, the organic binder contains an elastomer, and the bulk density of the porous body is 30 kg/m.sup.3 or less.

A glass filler of the present invention includes: a glass substrate; and a coating film including a surface treatment agent, the coating film covering at least a portion of a surface of the glass substrate. The glass substrate is a glass fiber having a flat cross-sectional shape. For the glass substrate, when a length corresponding to a minor axis of the flat cross-section of the glass fiber is represented by L1, a length corresponding to a major axis of the flat cross-section of the glass fiber is represented by L2, and a length corresponding to a fiber length of the glass fiber is represented by L3, a ratio of an average of L2 to an average of L1, (average of L2)/(average of L1), is 1.5 or more and 8 or less, the average of L1 is 1.0 μm or more and 10 μm or less, and an average of L3 is 80 μm or more and 160 μm or less. The surface treatment agent includes a silane coupling agent. A proportion of the coating film in the glass filler is 0.05 mass % or more and 2.5 mass % or less.

A glass filler of the present invention includes: a glass substrate; and a coating film including a surface treatment agent, the coating film covering at least a portion of a surface of the glass substrate. The glass substrate is a glass fiber having a flat cross-sectional shape. For the glass substrate, when a length corresponding to a minor axis of the flat cross-section of the glass fiber is represented by L1, a length corresponding to a major axis of the flat cross-section of the glass fiber is represented by L2, and a length corresponding to a fiber length of the glass fiber is represented by L3, a ratio of an average of L2 to an average of L1, (average of L2)/(average of L1), is 1.5 or more and 8 or less, the average of L1 is 1.0 μm or more and 10 μm or less, and an average of L3 is 80 μm or more and 160 μm or less. The surface treatment agent includes a silane coupling agent. A proportion of the coating film in the glass filler is 0.05 mass % or more and 2.5 mass % or less.

A curable aqueous composition is disclosed comprising a carbohydrate, a crosslinking agent, and an amine base, wherein the curable aqueous composition has a pH adjusted by the amine base. Further disclosed is a method of forming a curable aqueous solution.