Water-dispersible polyester resins and process for their preparation

A process for the preparation of a polyester comprising

• (I) reacting the reactants (a), (b), (c), (d), and (e) under polycondensation conditions;
• (II) reacting the resultant polyester with about 1 to 15 weight % of at least one reactive oxirane containing compound wherein the reactants are:
• (a) at least one difunctional dicarboxylic acid which is not a sulfomonomer;
• (b) about 1 to 20 mol % of at least one dicarboxylic sulfomonomer containing at least one metallic sulfonate group or nitrogen-containing non-metallic sulfonate group attached to an aromatic or cycloaliphatic nucleus;
• (c) at least one difunctional reactant selected from a glycol or a mixture of a glycol and diamine having two --NRH groups, the glycol containing two --C(R.sup.1).sub.2 --OH groups wherein R in the reactant is hydrogen or an alkyl group of 1 to 6 carbon atoms, and R.sup.1 in the reactant is a hydrogen atom, an alkyl of 1 to 5 carbon atoms, or an aryl group of 6 to 10 carbon atoms;
• (d) about 0 to 40 mol % of difunctional reactant selected from hydroxycarboxylic acids having one --C(R).sub.2 --OH group, aminocarboxylic acids having one --NRH group, amino alcohols having one --C(R).sub.2 --OH group and one --NRH group, or mixtures of said difunctional reactants wherein R in the reactant is hydrogen or an alkyl group of 1 to 6 carbon atoms;
• and
• (e) 0 to 40 mol % of a multifunctional reactant containing at least three functional groups selected from hydroxyl, carboxyl, and mixtures thereof,
• wherein the resulting polyester has a predispersion pH greater than 4 with a substantial number of the carboxyl end groups attached to reactant (b) residue being capped and wherein all stated mol percentages are based on the total of all acid, hydroxyl and amino group containing reactants being equal to 200 mol %, and wherein the polymer contains proportions of acid-group containing reactants (100 mol % acid) to hydroxy- and amino-group containing reactants (100 mol % base) such that the value of EQ (base) divided by EQ (acid) is between about 1 and 1.6.

A process for the preparation of a polyester comprising reacting the following reactants under polycondensation conditions:

• (a) at least one difunctional dicarboxylic acid which is not a sulfomonomer;
• (b) about 1 to 20 mol % of at least one diol that is a diester adduct of a glycol and a dicarboxylic acid sulfomonomer containing at least one metallic sulfonate group or nitrogen-containing non-metallic sulfonate group attached to an aromatic or cycloaliphatic nucleus;
• (c) at least one difunctional reactant selected from a glycol or a mixture of a glycol and diamine having two --NRH groups, the glycol containing two --C(R.sup.1).sub.2 --OH groups wherein R in the reactant is hydrogen or an alkyl group of 1 to 6 carbon atoms, and R.sup.1 in the reactant is a hydrogen atom, an alkyl of 1 to 5 carbon atoms, or an aryl group of 6 to 10 carbon atoms;
• (d) about 0 to 40 mol % of difunctional reactant selected from hydroxycarboxylic acids having one --C(R).sub.2 --OH group, aminocarboxylic acids having one --NRH group, amino-alcohols having one --C(R).sub.2 --OH group and one --NRH group, or mixtures of said difunctional reactants wherein R in the reactant is hydrogen or an alkyl group of 1 to 6 carbon atoms;
• and
• (e) 0 to 40 mol % of a multifunctional reactant containing at least three functional groups selected from hydroxyl, carboxyl, and mixtures thereof,
• wherein the resulting polyester has a predispersion pH greater than 4 with a substantial number of the carboxyl end groups attached to reactant (b) residue being capped and wherein all stated mol percentages are based on the total of all acid, hydroxyl and amino group containing reactants being equal to 200 mol %, and wherein the polymer contains proportions of acid-group containing reactants (100 mol % acid) to hydroxy- and amino-group containing reactants (100 mol % base) such that the value of EQ (base) divided by EQ (acid) is between about 1 and 1.6.