Method of making thermally curable wet-impregnated rovings
AssigneeDeSoto, Inc.
InventorsMark R. Zentner, Orvid R. Cutler
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Abstract
Thermally curable wet-impregnated rovings are disclosed in which the fibers of the roving are impregnated with a liquid polyepoxide having dispersed therein a latent heat-activatable epoxy curing catalyst, such as dicyandiamide, the polyepoxide dispersion having a room temperature viscosity of from 2000 to 5000 centipoises and a tack of less than about 6 on a Thwing-Albert inkometer. The rovings are produced without organic solvent by passing a dry multifillament roving through an elevated temperature bath of the polyepoxide dispersion, this elevated temperature being insufficient to activate the curing catalyst and functioning to lower the viscosity to enable uniform impregnation. The wet rovings are stored in a supply package.
Claims5
A method of producing a thermally curable wet-impregnated roving which can be wound into a wet supply package in which the impregnant does not run and from which the wet-impregnated roving can be withdrawn, comprising impregnating untwisted dry multifilament roving with a heated liquid polyepoxide having dispersed therein a latent heat-activatable epoxy curing catalyst, said polyepoxide dispersion having a room temperature viscosity of from 2000 to 5000 centipoises and a tack of less than about 6 on a Thwing-Albert inkometer, said liquid being heated to an elevated temperature which is insufficient to activate said curing catalyst and functioning to lower the viscosity to enable uniform impregnation of the roving in the absence of volatile organic solvent, and then removing any excess impregnant which may be present.
Dependencies are inferred from the claim text.