Penetrating stains and sealants from polyurethane dispersions

A method of applying a waterborne, penetrating composition to a porous substrate comprising applying to the surface of a porous substrate a waterborne penetrating composition which penetrates into said substrate and does not form an appreciable film on said substrate, said waterborne penetrating composition comprising an aqueous dispersion of a polyurethane-urea having a particle size diameter of less than about 0.4 micron;

• wherein the polyurethane-urea comprises the dispersion in an aqueous media of the reaction product of:
• i) at least two active-hydrogen containing compounds with
• ii) at least one diisocyanate-functional material;
• wherein the reaction between i) and ii) takes place in the presence of between about 0.01% to about 0.06% by weight of a catalyst;
• wherein one of the active-hydrogen containing compounds is difunctional with respect to isocyanate groups;
• wherein one of the active-hydrogen containing compounds is monofunctional with respect to isocyanate groups and also contains a C6 or greater aliphatic chain and imparts water resistance to the substrate;
• wherein the ratio of i) to ii) is such that the ratio of isocyanate functionality to total active-hydrogen functionality is in the range of between about 1.01:1 to about 2.0:1;
• wherein between about 1% to about 50% of the molar equivalents of the total active-hydrogen functionality is contributed by the monofunctional active-hydrogen containing compound;
• wherein between about 1% and about 10% of the total polymer weight solids is contributed by active-hydrogen containing compounds having the ability to contribute ionic or hydrophilic groups to the polyurethane-urea;
• and wherein the reaction product of i) and ii) is at least about 80% neutralized with a weak base prior to dispersion in said aqueous media.

A waterborne, penetrating wood stain comprising:

• a) an aqueous dispersion of a polyurethane-urea having a particle size diameter of less than about 0.4 micron;
• wherein the polyurethane-urea comprises the dispersion in an aqueous media of the reaction product of:
• i) at least two active-hydrogen containing compounds with
• ii) at least one diisocyanate-functional material;
• wherein the reaction between i) and ii) takes place in the presence of between about 0.01% to about 0.06% by weight of a catalyst;
• wherein one of the active-hydrogen containing compounds is difunctional with respect to isocyanate groups;
• wherein one of the active-hydrogen containing compounds is monofunctional with respect to isocyanate groups and also contains a C6 or greater aliphatic chain;
• wherein the ratio of i) to ii) is such that the ratio of isocyanate functionality to total active-hydrogen functionality is in the range of between about 1.01:1 to about 2.0:1;
• wherein between about 1% to about 50% of the molar equivalents of the total active-hydrogen functionality is contributed by the monofunctional active-hydrogen containing compound;
• wherein between about 1% and about 10% of the total polymer weight solids is contributed by active-hydrogen containing compounds having the ability to contribute ionic or hydrophilic groups to the polyurethane-urea;
• and wherein the reaction product of i) and ii) is at least about 80% neutralized with a weak base prior to dispersion in said aqueous media.

A waterborne, penetrating water sealant composition comprising:

• a) an aqueous dispersion of a polyurethane-urea having a particle size diameter of less than about 0.4 micron;
• wherein the polyurethane-urea comprises the dispersion in an aqueous media of the reaction product of:
• i) at least two active-hydrogen containing compounds with
• ii) at least one diisocyanate-functional material;
• wherein the reaction between i) and ii) takes place in the presence of between about 0.01% to about 0.06% by weight of a catalyst;
• wherein one of the active-hydrogen containing compounds is difunctional with respect to isocyanate groups;
• wherein one of the active-hydrogen containing compounds is monofunctional with respect to isocyanate groups and also contains a C6 or greater aliphatic chain;
• wherein the ratio of i) to ii) is such that the ratio of isocyanate functionality to total active-hydrogen functionality is in the range of between about 1.01:1 to about 2.0:1;
• wherein between about 1% and about 50% of the molar equivalents of the total active-hydrogen functionality is contributed by the monofunctional active-hydrogen containing compound;
• wherein between about 1% and about 10% of the total polymer weight solids is contributed by active-hydrogen containing compounds having the ability to contribute ionic or hydrophilic groups to the polyurethane-urea;
• and wherein the reaction product of i) and ii) is at least about 80% neutralized with a weak base prior to dispersion in said aqueous media;
• and
• b) at least one paraffin or wax.