Phenolic resins for reinforced composites

A method of making a reinforced composite which comprises:

• (1) coating reinforcing components with an aqueous binder composition having a pH at least about 7 comprising an aqueous mixture of:
• (i) 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
• (ii) a water-soluble borate,
• wherein said 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 and about 0.5 mole borate per mole of phenol;
• (2) drying said coated reinforcing component with minimal curing of said binder to form a prepreg;
• (3) forming a structure with at least one of said prepregs;
• and
• (4) applying pressure and heat to said structure to cure said dried binder into a matrix forming said composite.

A method of making a reinforced composite which comprises:

• (1) coating a honeycombed reinforcing component with an aqueous binder composition having a pH at least about 7 comprising an aqueous mixture of:
• (i) 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
• (ii) a water-soluble borate,
• wherein said 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 and about 0.5 mole borate per mole of phenol;
• (2) curing the binder coating on said coated reinforcing component;
• and
• (3) repeating steps (1) and (2) until a desired cured binder content in said honeycombed reinforcing member is achieved forming said composite.

A method for preparing a phenolic resole resin composition comprising:

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