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 in the presence of an ortho directing catalyst at a mole ratio of formaldehyde to phenol ranging from about 0.7:1 to about 3:1 and (b) a water-soluble borate, wherein the composition contains at least about 0.02 equivalent of the ortho directing catalyst per mole of phenol, has a pH at least about 7 and contains from about 0.02 to about 0.5 mole borate per mole of phenol. When the ortho directing catalyst has a cation that forms an insoluble material with a borate anion, the cation is removed after the resole is formed and prior to adding the water-soluble borate.