| 摘要 |
Waterborne polyurethane dispersions are prepared by reacting (1) at least one polyisocyanate; (2) at least one active hydrogen containing compound, such as a polyol or a polyamide; and (3) optionally, at least one water-dispersability enhancing compound having water-dispersion enhancing groups, in order to form an isocyanate terminated prepolymer. The prepolymer subsequently is (1) optionally neutralized by reaction with at least one neutralizing agent, (2) dispersed in water, and then (3) chain extended by reaction with at least one of water, inorganic or organic polyamine having an average of about 2 or more primary and/or secondary amine groups, or combinations thereof. At least one plasticizer is introduced into the reaction mixture at any time during prepolymer formation or before the prepolymer is dispersed in water. The plasticizer substantially or completely replaces other organic diluents or solvents. The compositions prepared by the process of the present invention are less hazardous, typically have lower modulus and higher solids than compositions of the prior art prepared using diluents such as N-methyl-2-pyrrolidone or solvents such as acetone, and are useful in applications such as surgical gloves. However, reaction components can be varied to include reactive plasticizers and other ingredients for preparation of harder materials useful in other articles, or to impregnate, saturate, spray or coat papers, non-woven materials, textiles, wood, metals, polymeric articles, and a variety of other substrates. Applications include gloves; papers and non-wovens; fibrous materials such as textiles; films, sheets, composites, and other articles; inks and printing binders; flock and other adhesives; and personal care products.
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