Polyurethane resin containing a phosphoric acid group

A polyurethane resin, comprising:

• a urethane resin synthesized from a reactant mixture of at least one phosphorus compound, an epoxy compound having at least two epoxy groups, one epoxy group and at least one hydroxyl group, or combinations thereof,
• a polyisocyanate, and
• a polyfunctional hydroxyl compound having a molecular weight by end group analysis of from about 300 to about 10,000, and
• optionally, a chain extender,
• said urethane resin containing one phosphoric acid group or one residual group derived from phosphoric acid per 3,000 to about 200,000 number average molecular weight of said urethane resin, said urethane resin having a weight average molecular weight of from about 10,000 to about 350,000;
• said phosphorus compound being a phosphorus compound (a) represented by the structural formula set forth below, or a phosphorus compound (b) represented by the structural formula set forth below, or a phosphorus compound (c) set forth by the structural formula set forth below,
• said phosphorus compound (a) being a compound (a.sub.1) alone or a mixture of the compound (a.sub.1 and another compound (a.sub.2):
• Compound (a.sub.1):
• ##STR10## wherein R.sup.1 is a hydrogen atom, a phenyl group, an alkyl group having 1-40 carbon atoms, or an alkylphenyl group having 1-40 carbon atoms, and n is an integer of 0-30. ##STR11## wherein R.sup.2 is a phenyl group, an alkyl group having 1-40 carbon atoms, or an alkylphenyl group having 1-40 carbon atoms;
• and wherein phosphorus compound (c) is ##STR12## where R.sup.3 is an aromatic or an alkyl substituted aromatic having from 6 to 40 carbon atoms, and R.sup.4 is a disubstituted alkyl having from 1 to 12 carbon atoms.