Metal salt of crosslinked cellulose derivative
The invention provides a metal salt of a crosslinked cellulose derivative represented by the following formula (I), wherein the degree of substitution of the hydroxyl group of glucose unit of the crosslinked cellulose derivative by a functional group a is 1 or more. R—O—A (I) {In the formula (I), R represents a crosslinked cellulose residue and A represents a functional group a having cation-exchange ability.}
1. A metal salt of a crosslinked cellulose represented by the following formula (I), wherein the degree of substitution of the hydroxyl group of glucose unit of the crosslinked cellulose by a functional group “A” is 1 or more:
R—O—A (I)
wherein R represents a crosslinked cellulose residue and A represents —SO 3 H,
wherein the degree of crosslinking is 0.174-0.3, both inclusive, and
the degree of substitution n is calculated by the following equation:
n =(the molecular weight of one unit of crosslinked cellulose)* Y÷[y/m −((molecular weight of SO 3 H)−(atomic weight of one hydrogen))* Y]
Y: the elemental analysis value of sulfur,
y: the atomic weight of sulfur,
m: the atomic valence of sulfur.