Preparation of solid polyurethane particles
AssigneeW. R. Grace & Co.
InventorsNelson S. Marans, Clifton L. Kehr
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Abstract
This invention relates to novel hydrophilic, crosslinked, polyurea-urethane, solid, discrete particles formed by adding in droplet form a hydrophilic prepolymer comprising an isocyanate-capped polyol or mixtures thereof wherein said polyol or mixture of polyols has a reaction functionality greater than two, the total of said polyol present having an ethylene oxide content of at least 40 weight percent, before capping to a large excess of a stirred aqueous reactant. The resultant solid particles can be molded into various shapes as desired or used for coating or adhesive applications.
Claims3
A process for forming solid, discrete, hydrophilic, crosslinked polyurea-urethane particles having an average diameter in the range 0.1-100 mils consisting of adding a droplet form and in the absence of an emulsifying agent
- (a) a hydrophilic prepolymer comprising an isocyanate-capped polyol or mixtures thereof wherein said polyol or mixture of polyol has a reaction functionality greater than two, the total of said polyol present having an ethylene oxide content of at least 40 weight percent before capping, to
- (b) an agitated water reactant, the volume ratio of (b):(a) being at least 2:1 and thereafter recovering the thus formed polyurea-urethane particles therefrom.
Dependencies are inferred from the claim text.