TWI836096B

Carboxymethyl cellulose or a salt thereof is adjusted to a form such that D10 is 90 μm or higher, D50 is 120-470 μm, and D90 is 500 μm or lower, where D10, D50, and D90 are, respectively, the 10% cumulative, 50% cumulative, and 90% cumulative grain sizes from the small-grain-size side in the volume-based cumulative grain size distribution. D10 may be about 100 μm or higher, D50 may be about 150-200 μm, and D90 may be about 250 μm or lower. In granular carboxymethyl cellulose or a salt thereof, the proportion of particles having a roundness of 50% or higher may be about 90 vol% or higher with respect to the whole, and the proportion of particles having a roundness of 70% or higher may be about 70 vol% with respect to the whole. The carboxymethyl cellulose or salt thereof can be dissolved efficiently in water even with gentle stirring.