摘要 |
A curable vinyl ester resin composition capable of undergoing B-staging at room temperature comprises (a) an unmodified vinyl ester resin; (b) a reactive diluent consisting of an ethylenically unsaturated monomer; (c) a free-radical curing agent; (d) a B-staging agent comprising a Group II metal oxide or hydroxide, or a mixture thereof; and (e) a thickening agent comprising an ester, a ketone, an aldehyde or a mixture thereof. The thickening agent coacts with the B-staging agent to cause B-staging of the vinyl ester resin at room temperature. The vinyl ester resin composition according to the invention is particularly useful for impregnating a fibrous material such as a woven fabric material. The fibrous material impregnated with the vinyl ester resin composition of the invention has a shelf life of up to 12 months. B-stage is generally reached in about two weeks following mixture of the various components and impregnation of the fibrous material.
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