| abstract |
The instant invention is an ultra-high solid content polyurethane dispersion, and a continuous process for producing ultra-high solid content polyurethane dispersions. The ultra-high solid content polyurethane dispersion includes the reaction product of: (1) a first component, wherein the first component is a first polyurethane prepolymer or a first polyurethane prepolymer emulsion; (2) a second component, wherein the second component is a second polyurethane prepolymer, a second polyurethane prepolymer emulsion, a low solid content polyurethane dispersion, a seed latex, or combinations thereof; (3) and a chain extender. The ultra-high solid content polyurethane dispersion has a solid content of at least 60 percent by weight of the solid, based on the total weight of the ultra-high solid content polyurethane dispersion, and a viscosity in the range of less than 5000 cps at 20 rpm at 21° C using spindle #4 with Brookfield viscometer. The method for producing a high-solid content polyurethane dispersion includes the following steps: (1) providing a first stream, wherein said first stream comprising a first polyurethane prepolymer or a first polyurethane prepolymer emulsion; (2) providing a second stream, wherein said second stream being a media phase selected from the group consisting of a second polyurethane prepolymer, a second polyurethane prepolymer emulsion, a polyurethane prepolymer dispersion, a seed latex emulsion, or combinations thereof; (3) continuously merging said first stream with said second stream in the presence of a chain extender; and (4) thereby forming a polyurethane dispersion having a solid content of at least 60 percent by weight of the solid, based on the total weight of the ultra-high solid content polyurethane dispersion, and a viscosity in the range of less than 5000 cps at 20 rpm at 21° C using spindle #4 with Brookfield viscometer. |