Pultrusion systems and process
AssigneeHuntsman International LLC
InventorsRavi R. Joshi, Evan H. Cheolas
Life of this patent
Estimating the term…
Abstract
Polyisocyanate-based reaction systems, a pultrusion process of those systems to produce reinforced matrix composites, and to composites produced thereby. The polyisocyanate-based systems are mixing activated reaction systems that include a polyol composition, an optional chain extender or crosslinker, and a polyisocyanate. The polyisocyanate-based systems exhibit improved processing characteristics in the manufacture of fiber reinforced thermoset composites via reactive pultrusion.
Claims34
A reaction system for the preparation of a fiber reinforced composite according to the pultrusion process comprising:
- a. a reaction mixture comprising an isocyanate reactive composition, a polyisocyanate composition, and optionally one or more additives;
- and
- b. a continuous fiber reinforcing material, wherein the reaction mixture initially contains both free isocyanate groups and free alcoholic OH groups, has a gel time greater than 768 seconds at 25° C., and a gel time less than 120 seconds at 175° C.
A pultrusion process for preparing a fiber reinforced composite comprising the steps of:
- (a) pulling continuous fibers through an impregnation die while contacting the fibers with a reaction mixture comprising an isocyanate reactive composition, a polyisocyanate composition, and optionally one or more additives, sufficient to cause substantial polymerization of the reaction mixture within the impregnation die to produce a composite of fibers coated by the reaction mixture, which is not fully cured,
- (b) directing the composite of fibers coated by the reaction mixture through a heated curing die to further advance the cure of the reaction mixture so as to produce a solid fiber reinforced composite, and
- (c) withdrawing the solid fiber reinforced composite from the curing die;
- wherein the reaction mixture initially contains both free alcoholic —OH groups and free isocyanate (—NCO) groups, has a gel time of greater than 768 seconds at 25° C., and a gel time of less than 120 sec at 175° C.
Dependencies are inferred from the claim text.