Low density, polybutadiene based, wet filament winding resin

Claim 1

A wet filament winding resin having a viscosity which is between about 1,000 and 5,000 centipoise at a temperature in a range between about 20° and 60° C., a density below about 1.05 grams/cubic centimeter at 25° C. after cure and a pot life which is up to about four months or more at 25° C. where pot life is defined as the time for a winding resin to reach a viscosity of 5,000 centipoise at the winding temperature, said wet filament winding resin being an intimate admixture of components consisting essentially of: (a) a crosslinkable polymer component in an amount at least about 30% by weight of said resin, said polymer component consisting essentially of unsaturated polybutadiene polymers essentially free of crosslinkable functionality other than the unsaturation thereof, 100 parts by weight of said unsaturated polybutadiene polymers being a first polybutadiene having a number average molecular weight between about 10,000 and 40,000 and a 1,2 vinyl content between 50 and 95% based on total unsaturation present in said first polybutadiene and between about 5 and 100 parts by weight of a second polybutadiene having a number average molecular weight lower than said first polybutadiene and between about 1000 and 2500 and a 1,2 vinyl content between about 1 and 95% based on total unsaturation present in said second polybutadiene; (b) between about 5 and 150 parts by weight per 100 parts by weight of said first polybutadiene of an unsaturated monomer component that has a lower viscosity than said crosslinkable polymer component, said unsaturated monomer component comprising a monomer having a carbon carbon double bond; and (c) between about 1 and 10 parts by weight per 100 parts by weight of said first polybutadiene of an initiator component comprising a peroxide-free radical initiator having a 10 hour half life at a temperature greater than 55° C.