Glasfasern

A composition suitable for coating glass fibres used as constituents of moulding compositions comprises a saturated polyester resin which is a reaction product of a saturated dicarboxylic acid and a saturated dihydric alcohol, a plurality of discrete particles of inert material which is insoluble in the resin and of which the diameters are less than the diameters of the glass fibres to be treated and a resin-to-glass coupling agent. The polyester resin is preferably produced by the reaction of propylene glycol with succinic and phthalic anhydrides in a closed reactor in the presence of triphenyl phosphite with nitrogen bubbled through the reactor mixture, although other polyesters produced from adipic, oxalic, malonic or glutaric acids or their anhydrides and ethylene glycol, triethylene glycol, butylene glycol or polyethylene glycol may be used. The particulate material may be dioctadecyl ammonium bentonite, boehmite alumina fibres, silica, calcium carbonate, clay or a pigment. The resin-to-glass coupling agent may be an organosilane having the formula RnSiX4- n in which R is a carbocy, carboxy-alkoxy, alkenyl or alkyl group, e.g. an acrylate, methacrylate, vinyl, allyl, methallyl, crotyl, or ethyl group, X is a hydrolysable group, e.g. a halogen, alkoxy, aryloxy or amino group, and n is an integer having a value of 1-3, or a Werner chromium complex compound having a carboxylate group co-ordinated with a trivalent nuclear chromium atom. The composition which may be applied to the fibres in the form of an aqueous dispersion, may also contain lubricants, e.g. condensates of amines with fatty acids such as stearic and pelargonic acids, vegetable, animal or mineral oils and polyalkylene glycols, emulsifiers, e.g. ammonium hydroxide, protective colloids, e.g. polyvinyl alcohol, and plasticizers.ALSO:Glass fibres are coated with a composition comprising a saturated polyester resin which is a reaction product of a saturated dicarboxylic acid and a saturated dihydric alcohol, a plurality of discrete particles of inert material which is insoluble in the resin and of which the diameters are less than the diameters of the glass fibres and a resin-to-glass coupling agent, and are then grouped together into substantially parallel relationship to form a structure. The saturated polyester resin may be made from propylene glycol, ethylene glycol, triethylene glycol, butylene glycol or polyethylene glycol and succinic anhydride and phthalic anhydride or adipic, osalic, ma