GB908191A - Processes and compositions for coating glass fibres - Google Patents

Abstract

A composition suitable for coating glass fibres or strands, yarns, mats or fabrics made therefrom comprises an aqueous emulsion containing a first polyester resin which cures to give a tough, rigid polymer formed by condensation of a glycol with dicarboxylic acids or ester-forming derivatives thereof consisting at least in part of an unsaturated dicarboxylic acid or ester forming derivative thereof and a second polyester resin which cures to give a flexible polymer formed by condensation of a glycol with dicarboxylic acids or ester-forming derivatives thereof consisting at least in part of a saturated dicarboxylic acid or ester-forming derivative thereof, the first resin being of high viscosity relative to the second. The high viscosity polyester may be the reaction product of diethylene glycol, maleic anhydride and phthalic acid and the low viscosity polyester may be the reaction product of diethylene glycol, maleic anhydride and succinic acid. The treating composition may also contain an anchoring agent for binding the polyesters to glass surfaces, e.g. organo-silicon compounds having attached directly to the silicon atom an aliphatic organic radical which contains less than 8 carbon atoms and preferably has ethylenic unsaturation such as gamma amino propyl triethoxy silane, vinyl triacetoxy silane, vinyl trichloro silane, vinyl tri[(beta-methoxy) ethoxy] silane, allyl dichloro-silane, allyl trichlorosilane and the sodium derivative of vinyl silanol, tri(diethyl ethanolamine hydrochloride) stearyl silane, Werner complex compounds such as stearato chromic chloride and titanium salts such as titanium lactate. Surface active agents mentioned are polyvinyl alcohol, the reaction product of a diamine, ethylene oxide and lauric acid, phenolic or nonionic fatty acid derivatives of polyethylene glycols, the reaction product of tetraethylene pentamine epichlorhydrin and a fatty acid, polyalkylene oxide derivatives of sorbitan mono-oleate or palmitate and a condensate of ethylene oxide with a hydrophobic base formed by condensing propylene oxide with propylene glycol. The hydrocarbon comonomer having an unsaturated carbon-carbon linkage specified is styrene. Specified catalysts are benzoyl peroxide and cobalt naphthenate. The composition which may be adjusted to an acid pH by the addition of acetic, formic, hydrochloric or sulphuric acid preferably contains polyvinyl alcohol and anchoring agent in the weight ratio in the range 1:3 to 1:6. The composition may be applied to the glass fibres as they are formed or on to a mat of the fibres on a conveyer belt. Alternatively the fibres may be treated with the anchoring agent during forming and then treated with the composition without any anchoring agent. On heating to 300 DEG to 400 DEG C. the water evaporates and the two polyesters and the styrene copolymerize. Specifications 719,466, 748,391, 755,957, 769,194 and U.S.A. Specification 2,273,040 are referred to.ALSO:Glass fibres or strands, yarns, mats or fabrics made therefrom are coated with an aqueous emulsion containing a first polyester resin which cures to give a tough, rigid polymer formed by condensation of a glycol with dicarboxylic acids or ester-forming derivatives thereof consisting at least in part of an unsaturated dicarboxylic acid or ester forming derivative thereof and a second polyester resin which cures to give a flexible polymer formed by condensation of a glycol with dicarboxylic acids or ester-forming derivatives thereof consisting at least in part of a saturated dicarboxylic acid or esterforming derivative thereof, the first resin being of high viscosity relative to the second, and then heated, e.g. to 300 DEG -400 DEG F., to obtain a hard protective coating thereon. The high viscosity polyester may be the reaction product of diethylene glycol, maleic anhydride and phthalic acid and the low viscosity polyester may be the reaction product of diethylene glycol, maleic anhydride and succinic acid. The treating composition may also contain an anchoring agent for binding the polyesters to glass surfaces, e.g. organosilicon compounds having attached directly to the silicon atom an aliphatic organic radical which contains less than 8 carbon atoms and preferably has ethylenic unsaturation such as gamma amino propyl triethoxy silane, vinyl triacetoxy silane, vinyl trichloro silane, vinyl tri[(beta-methoxy) ethoxy] silanol, tri(diethyl ethanolamine hydrochlosilane and the sodium derivative of vinyl silanol, tri(diethyl ethanolamine hydrochloride) stearyl silane, Werner complex compounds such as stearato chromic chloride and titanium salts such as titanium lactate, polyvinyl alcohol, surface active agents, e.g. the reaction product of a diamine, ethylene oxide and lauric acid, phenolic or nonionic fatty acid derivatives of polyethylene glycols, polyalkylene oxide derivatives of sorbitan mono-oleate or palmitate and a condensate of ethylene oxide with a hydrophobic base formed by condensing propylene oxide with propylene glycol. The hydrocarbon comonomer having an unsaturated carboncarbon linkage specified is styrene. Specified catalysts are benzoyl peroxide and cobalt naphthenate. The composition which may be adjusted to an acid pH by the addition of acetic, formic, hydrochloric or sulphuric acid preferably contains polyvinyl alcohol and anchoring agent in the weight ratio in the range 1 : 3 to 1 : 6. The composition may be applied to the glass fibres as they are formed or on to a mat of the fibres on a conveyer belt. Alternatively the fibres may be treated with the anchoring agent during forming and then treated with the composition without any anchoring agent. The coated glass fibres or strands, yarns, mats or fabrics made therefrom may be combined with polyester or epoxy resins to produce glass fibre reinforced synthetic resin products. Specifications 719,466, 748,391, 755,957, 769,194 and U.S.A. Specifications 2,273,040 are referred to.