Lignin modified phenol-formaldehyde resins
AssigneeGeorgia-Pacific Resins, Inc.
InventorGlen A. Doering
Life of this patent
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Abstract
A modified resole resin and an adhesive composition containing the resin wherein the resin is prepared by first reacting formaldehyde and a phenol at a mole ratio of formaldehyde to phenol of less than about 1.0 in the presence of alkaline in an amount sufficient to provide a mole ratio of said alkaline material to phenol between about 0.04 and 0.08 to form a precursor resin; reacting the precursor resin with lignin to form a lignin-modified phenol-formaldehyde precursor resin, and then reacting the lignin-modified phenol-formaldehyde precursor with additional formaldehyde sufficient to provide a cumulative formaldehyde to phenol mole ratio of between about 2.0 and about 3.0. The adhesive composition is useful in bonding wood chips, veneers and sheets of plywood.
Claims45
A lignin-modified resole resin prepared by:
- (a) reacting formaldehyde and a phenol at a mole ratio of formaldehyde to phenol of less than about 1.0 at a low level of alkalinity to form a precursor resin;
- (b) reacting precursor resin with lignin to form a lignin-modified phenolformaldehyde precursor resin;
- and
- (c) then reacting the lignin-modified phenol-formaldehyde precursor resin with additional formaldehyde sufficient to provide a cumulative formaldehyde to phenol mole ratio of between about 2.0 and about 4.0.
A method of making a lignin-modified resole resin comprising:
- (a) reacting formaldehyde and a phenol at a mole ratio of formaldehyde to phenol of less than about 1.0 in the presence of an alkaline material in an amount sufficient to provide an alkaline material to phenol mole ratio of between about 0.04 and 0.08 to form a precursor resin;
- (b) reacting precursor resin with lignin to form a lignin-modified phenolformaldehyde precursor resin;
- and
- (c) then reacting the lignin-modified phenol-formaldehyde precursor resin with additional formaldehyde sufficient to provide a cumulative formaldehyde to phenol mole ratio of between about 2.0 and about 4.0.
A lignin-modified phenol-formaldehyde precursor resin prepared by:
- (a) reacting formaldehyde and a phenol at a mole ratio of formaldehyde to phenol of less than about 1.0 at a low level of alkalinity to form a precursor resin;
- and
- (b) reacting precursor resin with lignin to form a lignin-modified phenolformaldehyde precursor resin.
The method of making a lignin-modified phenol-formaldehyde precursor resin comprising:
- (a) reacting formaldehyde and a phenol at a mole ratio of formaldehyde to phenol of less than about 1.0 in the presence of an alkaline material in an amount sufficient to provide an alkaline material to phenol mole ratio between about 0.04 and 0.08 to form a precursor resin;
- and
- (b) reacting precursor resin with lignin to form a lignin-modified phenol-formaldehyde precursor resin.
Dependencies are inferred from the claim text.