JP-2022508013-A5 -

Dates

Publication Date

20221201

Application Date

20180921

Description

In the first aspect, the present invention is (A) An aqueous dispersion comprising an emulsion polymer and a surfactant selected from the group consisting of a sulfate surfactant, a sulfonate surfactant that does not contain either a carboxyl group or a carboxylate group, or a mixture thereof, wherein the emulsion polymer having a weight-average molecular weight of 70,000 g/mol or less is determined by weight basis based on the weight of the emulsion polymer. The two-component polyurethane composition comprises (B) a water-dispersible polyisocyanate, an aqueous dispersion containing more than 0.25% of structural units of phosphorus-containing acid monomers and/or their salts, more than 15% of structural units of hydroxy-functional alkyl (meth)acrylates and monoethylene-unsaturated nonionic monomers, and 0 to 10% of structural units of additional acid monomers and/or their salts. In a second aspect, the present invention is a process for preparing the two-component polyurethane composition of the first aspect. This method is (i) To provide an aqueous dispersion comprising an emulsion polymer having a weight-average molecular weight of 70,000 g/mol or less, and a surfactant selected from the group consisting of a sulfate surfactant, a sulfonate surfactant that does not contain either a carboxyl group or a carboxylate group, or a mixture thereof, wherein the emulsion polymer prepared by emulsion polymerization in the presence of a chain transfer agent is weight-based on the weight of the emulsion polymer, To provide an aqueous dispersion containing more than 0.25% of structural units of phosphorus-containing acid monomers and/or their salts, more than 15% of structural units of hydroxy-functional alkyl (meth)acrylates and monoethylenically unsaturated nonionic monomers, and 0 to 10% of structural units of additional acid monomers and/or their salts. (ii) Mixing the aqueous dispersion from step (i) with a water-dispersible polyisocyanate. The aqueous dispersions useful in the present invention also include one or more surfactants selected from sulfate surfactants, sulfonate surfactants that do not contain carboxyl or carboxylate groups , or mixtures thereof. The surfactants useful in the present invention may have the structure of formula (I) or (II), In the formula, R1 and R2 are each independently a substituted or unsubstituted linear, branched or cyclic alkyl group having 8 to 18 carbon atoms, 10 to 14 carbon atoms, or 10 to 12 carbon atoms, or a substituted or unsubstituted arylalkyl group having 6 to 30 carbon atoms, 14 to 24 carbon atoms, or 16 to 20 carbon atoms, and OA represents an ethoxy, propoxy or butoxy group, or a combination thereof, preferably an ethoxy group. X + and M + are each independently an ammonium ion or an alkali metal ion, such as a sodium ion and a potassium ion, preferably a sodium ion. m is in the range of 0 to 60. n is either 0 or 1.