PURPOSE: To produce pulp having novel physical properties at a low cost regardless of broadleaf trees or needle-leaf trees without using sulfur and chlorine by using a specific cellulose derivative as an active component.
CONSTITUTION: Wood chips are pretreated by immersing in a digestion solution comprising 80-97% aqueous solution of propionic acid containing a small amount of hydrochloric acid at 50-70°C for 1-3hr and further digested in the digestion solution at 100-130°C, while the digestion solution is successively supplied. The digested wood chips are heated and washed with water-containing acetone. The washed chips are opened and screened to produce pulp containing as an active component a derivative of formula I (n>1500) having a crystallinity of ≤ approximately 52% and an ester content of 0.3-0.4 per pyranose ring. The compound of formula I has an estimated structure of formula II in which the hydroxyl groups are partially substituted with propionyl groups.
SHIMADA KINJI
HAYASHI NORIKO
HOSOYA SHUJI
TOMIMURA YOICHI
