Abstract: The present invention provides a novel water-soluble acid-type carboxymethyl cellulose characterized by:(a) having a total degree of substitution "x" by carboxymethyl group of 0.42 to 3.00 per anhydrous glucose unit, the degree of substitution "y" by acid-type carboxymethyl groups being to 100% of the total degree of substitution, provided that when "x" is less than 2.0, "y" shall be less than (1.25.times.-0.5), the remaining carboxymethyl group being of the alkali salt type,(b) having an average degree of polymerization of 50 to 1500, and(c) being soluble in water,which is useful as dispersant, carrier, coating agent and various other materials and also as an intermediate for carboxymethyl cellulose derivatives; and a process for preparing them.

Abstract: New esterified carboxymethyl celluloses in which DS by carboxymethyl group per anhydroglucose unit is 2.0 or more, the ester group is a hydrocarbon residue having 1-8 carbon atoms such as methyl, ethyl, n-octyl or benzyl group, DS by esterified carboxymethyl group per anhydroglucose unit is 1.50 or more and the remaining unsubstituted carboxymethyl groups are in the form of free acid and which are soluble in various polar or non-polar organic solvents and are useful as ingredients of paints of enteric coating materials.

Abstract: A process is disclosed for the preparation of an alkali salt of a carboxymethylcellulose ether by reacting a cellulosic material with an etherifying agent, in the presence of an alkali, in an aqueous organic solvent, wherein the improvement comprises adding the etherifying agent and only part of the entire amount of said alkali in the initial stage of the reaction, thereby initiating the etherification reaction in the presence of an excess amount of the etherifying agent such that the molar ratio of ##EQU1## is in the range of 0.10 to 0.99; and subsequently adding the remainder of said alkali in one or more portions in a second stage and carrying out the etherification reaction in such a manner that said molar ratio of alkali etherifying agent in the final stage becomes at least 1.00.