| abstract |
Poly(p-phenylene-2,6-benzobisoxazole) ("PBO") yarn or cord is first coated with a subcoat of a mixture of (a) an aliphatic polyglycidyl ether having a flash point greater than 150° C. with enough OH-groups to be substantially water-soluble and (b) a vinyl pyridine-styrene-butadiene rubber latex (VPSBRL), then coated in a conventional RFL dip, yields a twice-coated PBO yarn; this yarn provides adhesive strength in sulfur-vulcanizable rubber which is substantially the same as, or better than, that provided by aramid yarn having the same physical dimensions and construction, and coated with an aromatic polyglycidyl ether. |