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US 7,741,424 B2Granted
Phosphoric ester of cellulose derivative and metal adsorbent comprising the same
AssigneeKowa Company, Ltd.
InventorsMing Lu, Katsumi Yabusaki
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AssigneeKowa Company, Ltd.
InventorsMing Lu, Katsumi Yabusaki
Estimating the term…
The present invention is directed to a phosphoric ester of 2,3-dihydroxypropyl cellulose or 3-(2,3-dihydroxypropoxy)-2-hydroxypropyl cellulose, the cellulose having optionally undergone partial carbamidation, and to a metal absorbent employing the ester, and to a metal-absorbing apparatus employing the metal adsorbent. The cellulose derivative phosphoric ester serves as a metal adsorbent which exhibits high metal adsorption performance and metal adsorption rate per unit weight; has high mechanical strength; effectively soften water or a similar liquid; removes heavy metals from wastewater or a similar liquid at remarkably high efficiency; has excellent processability and can be formed into a variety of shapes and thus is applicable within a wide range; and can readily be reutilized.
A phosphoric ester of 2,3-dihydroxypropyl cellulose or a phosphoric ester of 2,3-dihydroxypropyl cellulose that has undergone carbamidation wherein the phosphoric ester has a phosphorous content of 10.0 to 15.7 wt. % and a nitrogen content of 0 to 8.0 wt. %.
The method as described in 2, wherein 0.0007 to 0.4 moles of said at least one of a phosphorus oxide, a phosphoryl halide, a phosphoric acid or a salt of the phosphoric acid is present relative to 1 gram of said 2,3-dihydroxypropyl cellulose.
The metal-adsorbing apparatus as described in 8, wherein the metal adsorbent is formed into a tube or a fabric and is placed in a water reservoir tank.
A phosphoric ester of 3-(2,3-dihydroxypropoxy)-2-hydroxypropyl cellulose or a phosphoric ester of 3-(2,3-dihydroxypropoxy)-2-hydroxypropyl cellulose that has undergone carbamidation.
Dependencies are inferred from the claim text.