Binders containing an aldehyde-based resin and an isocyanate-based resin and methods for making composite lignocellulose products therefrom

A binder for making composite lignocellulose products, comprising:

• about 32 wt % to about 38 wt % of solids comprising a urea-modified aldehyde-based resin, wherein the urea-modified aldehyde-based resin comprises a urea-modified phenol-formaldehyde resin having a formaldehyde to phenol molar ratio of about 1.8:1 to about 2.6:1;
• about 1 wt % to about 2 wt % of solids comprising an isocyanate-based resin;
• about 2.9 wt % to about 5.2 wt % of an extender;
• about 0.01 wt % to about 0.5 wt % of a surfactant, wherein the surfactant comprises an acetylenic diol compound, ethylene glycol, or a mixture thereof;
• and
• about 53 wt % to about 58 wt % of a liquid medium, wherein the binder comprises 4 wt % to about 9.5 wt % of free urea, mono-methylol urea, di-methylol urea, tri-methylol urea, urea covalently bonded with a carbon atom derived from an aldehyde during synthesis of the urea-modified aldehyde-based resin, or a mixture thereof, wherein all weight percent values are based on a total weight of the binder, and wherein the binder has a sodium hydroxide equivalent weight alkalinity of about 4.5 wt % to about 7.5 wt %.

A method for making a composite product, comprising:

• combining a plurality of lignocellulose substrates and a binder to produce a resinated furnish, wherein the binder comprises:
• about 32 wt % to about 38 wt % of solids comprising a urea-modified aldehyde-based resin, wherein the urea-modified aldehyde-based resin comprises a urea-modified phenol-formaldehyde resin having a formaldehyde to phenol molar ratio of about 1.8:1 to about 2.6:1;
• about 1 wt % to about 2 wt % of solids comprising an isocyanate-based resin;
• about 2.9 wt % to about 5.2 wt % of an extender;
• and
• about 53 wt % to about 58 wt % of a liquid medium, wherein the binder comprises 4 wt % to about 9.5 wt % of free urea, mono-methylol urea, di-methylol urea, tri-methylol urea, urea covalently bonded with a carbon atom derived from an aldehyde during synthesis of the urea-modified aldehyde-based resin, or a mixture thereof, wherein all weight percent values are based on a total weight of the binder, wherein the binder has a sodium hydroxide equivalent weight alkalinity of about 4.5 wt % to about 7.5 wt %, and wherein the binder is free of a surfactant;
• and
• heating the resinated furnish to a temperature of about 60° C. to about 300° C. to at least partially cure the binder to produce a composite lignocellulose product.