| 摘要 |
<p>A substantially boron-free method for making a cationic guar comprises reacting particles of polysaccharide with a derivatizing agent to produce derivatized polysaccharide particles, washing the derivatized polysaccharide particles, and contacting, prior to or after the washing step, the particles with a glyoxal compound in order to crosslink the derivatized polysaccharide particles. Also disclosed are methods for making crosslinked derivatized polysaccharides, comprising (a) contacting particles of a polysaccharide with a titanium compound in an aqueous medium having an alkaline pH under conditions appropriate to intra-particulately crosslink the particles; (b) reacting, prior to or after the step of contacting the particles of polysaccharide with the titanium compound, the particles of polysaccharide with a derivatizing agent under conditions appropriate to produce derivatized polysaccharide particles; (c) washing the titanium crosslinked and derivatized particles; (d) contacting, concurrently with or after the step of washing the titanium crosslinked and derivatized particles, such particles with an aqueous medium having an acidic pH under conditions appropriate to substantially de-crosslink the particles; and (e) contacting, concurrently with or after step (d), the de-crosslinked particles with a glyoxal compound under conditions appropriate to intra-particulately crosslink the particles. The crosslinked cationic guar of the present invention is especially useful in home and personal care formulations, especially formulations comprising silicone since it improves silicone deposition.</p> |
