Water dispersible, modified polyurethane and a thickened aqueous composition containing it

A water dispersible, modified polyurethane which is the product of a reaction conducted under substantially anhydrous conditions of:

• (a) polyisocyanate selected from the group consisting of 1,6-hexamethylene diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate and mixtures thereof;
• (b) polyether polyol in an amount ranging from about 0.10 to about 10.00 moles per mole of polyisocyanate, said polyether polyol having an average molecular weight in the range of from about 4,000 to about 20,000 and having the repeating unit ##STR3## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from the group consisting of H, CH.sub.3 and C.sub.2 H.sub.5 ;
• (c) modifying agent in an amount ranging from about 0.015 to about 3,400 moles per mole of polyisocyanate, said modifying agent being selected from the group consisting of .alpha., .omega.-diaminoalkanes, dicarboxylic acids, aminocarboxylic acids, and mixtures thereof;
• and
• (d) capping agent which is reactive with the reaction product of the polyisocyanate, the polyether polyol and the modifying agent and which is present in an amount sufficient to cap the reaction product of the polyisocyanate, the polyether polyol and the modifying agent.

A thickened aqueous composition comprising:

• (a) water;
• and
• (b) from about 0.005 to about 10.00% by weight of a water dispersible, modified polyurethane which is the product of a reaction conducted under substantially anhydrous conditions of:
• (i) polyisocyanate;
• (ii) polyether polyol in an amount ranging from about 0.10 to about 10.00 moles per mole of polyisocyanate;
• (iii) modifying agent in an amount ranging from about 0.015 to about 3.400 moles per mole of polyisocyanate, said modifying agent having the formula
• X.sub.x --R--Y.sub.y
• wherein R represents a group containing from 0 to 10 carbon atoms, X is a group containing at least one active hydrogen moiety selected from the group consisting of primary amino, secondary amino, carboxyl and mixtures thereof, Y is a group containing at least one active hydrogen moiety selected from the group consisting of primary amino, secondary amino, carboxyl, hydroxyl, mercapto and mixtures thereof, the sum of (x+y) is an integer greater than 1 and x is at least 1 wherein the modifying agent is composed of less than about 20 mole % of compounds wherein the sum of (x+y) is at least 3 and wherein the polyisocyanate, the polyether polyol and the modifying agent are used to form the polymer chain;
• and
• (iv) capping agent which is reactive with the reaction product of the polyisocyanate, the polyether polyol and the modifying agent and which is present in an amount sufficient to cap the reaction product of the polyisocyanate, the polyether polyol and the modifying agent.

A method of increasing the viscosity and improving the leveling characteristics of an aqueous composition comprising mixing the aqueous composition with from 0.005 to about 10.000% by weight of a water dispersible, modified polyurethane which is the product of a reaction conducted under substantially anhydrous conditions of

• (a) polyisocyanate;
• (b) polyether polyol is an amount ranging from about 0.10 to about 10.00 moles per mole of polyisocyanate;
• (c) modifying agent in an amount ranging from about 0.015 to about 3.400 moles per mole of polyisocyanate, said modifying agent having the formula
• X.sub.x --R--Y.sub.y
• wherein R represents a group containing from 0 to 10 carbon atoms, X is a group containing at least one active hydrogen moiety selected from the group consisting of primary amino, secondary amino, carboxyl and mixtures thereof, Y is a group containing at least one active hydrogen moiety selected from the group consisting of primary amino, secondary amino, carboxyl, hydroxyl, mercapto and mixtures thereof, the sum of (x+y) is an integer greater than 1 and x is at least 1 wherein the modifying agent is composed of less than about 20 mole% of compounds wherein the sum of (x+y) is at least 3 and wherein the polyisocyanate, the polyester polyol and the modifying agent are used to form the polymer chain;
• and
• (d) capping agent which is reactive with the reaction product of the polyisocyanate, the polyether polyol and the modifying agent and which is present in an amount sufficient to cap the reaction product of the polyisocyanate, the polyether polyol and the modifying agent.

A method of preparing a water dispersible modified polyurethane comprising:

• (a) reacting at a temperature in the range of from about 20 to about 150.degree. C. for from about 0.1 to about 48 hours under substantially anhydrous conditions
• (i) polyisocyanate,
• (ii) polyether polyol in an amount ranging from about 0.10 to about 10.00 moles per mole of polyisocyanate, and
• (iii) modifying agent in an amount ranging from about 0.015 to about 3.400 moles per mole of polyisocyanate, said modifying agent having the formula
• X.sub.x --R--Y.sub.y
• wherein R represents a group containing from 0 to 10 carbon atoms, X is a group containing at least one active hydrogen moiety selected from the group consisting of primary amino, secondary amino, carboxyl and mixtures thereof, Y is a group containing at least one active hydrogen moiety selected from the group consisting of primary amino, secondary amino, carboxyl, hydroxyl, mercapto and mixtures thereof, the sum of (x+y) is an integer greater than 1 and x is at least 1 wherein the modifying agent is composed of less than about 20 mole % of compounds wherein the sum of (x+y) is at least 3 and wherein the polyisocyanate, the polyether polyol and the modifying agent are used to form the polymer chain;
• (b) reacting with the reaction product of step a), at a temperature in the range of from about 20.degree. to about 150.degree. C. for from about 1 to about 48 hours and under substantially anhydrous conditions, capping agent in an amount sufficient to cap the reaction product of step (a) to thereby form the water dispersible modified polyurethane;
• and
• (c) recovering the water dispersible, modified polyurethane.