Process for modifying unsaturated polyester systems

Abstract

Unsaturated polyester resin systems are modified to provide a curable, stable water-in-oil emulsion by reacting the resin system with a hydrolized source of hypochlorite ion, while maintaining during the reaction a pH of at least 4, whereby the reaction is predominantly one of chlorohydration. The hypochlorite ion may be provided by addition of an aqueous solution of an inorganic salt of hypochlorous acid, e.g. by an aqueous solution of sodium, potassium, lithium, or calcium hypochlorite; or by an aqueous solution of a suitable chloramine; or the additive may comprise the reaction product of a chloramine with an aqueous solution of an inorganic salt of hypochlorous acid. The modified resin system yielded by the invention may include over 50% by weight of water; and high quantities of conventional fillers may be added without disrupting the emulsion. The cured products yielded from the modified resin systems have excellent mechanical characteristics, and are highly flame-retardant.

Dependencies are inferred from the claim text.