Phenolic resins for reinforced composites

摘要

The present invention is directed to a phenolic resin composition useful for preparing a binder for reinforced composites, to a binder for reinforced composites made using the phenolic resin composition, and to a reinforced composite made using the binder. The phenolic resin composition of the present invention contains an aqueous mixture of: (a) a resole formed by reacting phenol with formaldehyde at a mole ratio of formaldehyde to phenol ranging from about 0.6:1 to about 4:1 and (b) a sulfite or bisulfite, wherein the resole has a pH at least about 7 and less than 9.5 and the composition contains from about 0.007 to about 0.4 mole equivalent of sulfur per mole of phenol.