Method for producing modified cellulose fiber

A method for producing modified cellulose fibers comprising introducing one or more compounds selected from unsaturated group-containing alkylene oxide compounds and unsaturated group-containing glycidyl ether compounds and one or more compounds selected from an alkylene oxide compound represented by a general formula (3A) and a glycidyl ether compound represented by a general formula (4A) to a cellulose-based raw material in the presence of a base, via an ether bonding,

• wherein the modified cellulose fibers comprise cellulose fibers bound to one or more substituents, via an ether bonding, selected from substituents represented by the following general formula (1) and substituents represented by the following general formula (2):
• —CH2—CH(OH)—R1 (1)
• —CH2—CH(OH)—CH2—(OA)n—O—R1 (2)
• wherein each of R1 in the general formula (1) and the general formula (2) is independently a linear or branched, unsaturated alkyl group having 2 or more carbon atoms and 30 or less carbon atoms;
• n in the general formula (2) is a number of 0 or more and 50 or less;
• and
• A is a linear or branched, divalent saturated hydrocarbon group having 1 or more carbon atoms and 6 or less carbon atoms, and
• one or more substituents, via an ether bonding, selected from substituents represented by the following general formula (3) and substituents represented by the following general formula (4):
• wherein each of R2 in the general formulas (3), (3A), (4), and (4A) is independently a hydrogen, a saturated alkyl group having 1 or more carbon atoms and 30 or less carbon atoms, an aromatic group having 6 or more carbon atoms and 30 or less carbon atoms, or a saturated hydrocarbon group having an aromatic ring having 7 or more carbon atoms and 30 or less carbon atoms;
• n in the general formula (4) and (4A) is a number of 0 or more and 50 or less;
• and A is a linear or branched, divalent saturated hydrocarbon group having 1 or more carbon atoms and 6 or less carbon atoms,
• wherein the modified cellulose fibers have cellulose I crystal structure.

Modified cellulose fibers having an average fiber diameter of 5μm or more, wherein the modified cellulose fibers comprise cellulose fibers hound to one or more substituents, via an ether bonding, selected from substituents represented by the following general formula (1) and substituents represented by the following general formula (2):

• —CH2—CH(OH)—R1 (1)
• —CH2—CH(OH)—CH2—(OA)n—O—R1 (2)
• wherein each of R1 in the general formula (1) and the general formula (2) is independently a linear or branched, unsaturated alkyl group having 2 or more carbon atoms and 30 or less carbon atoms;
• n in the general formula (2) is a number of 0 or more and 50 or less;
• and A is a linear or branched, divalent saturated hydrocarbon group having 1 or more carbon atoms and 6 or less carbon atoms,
• wherein the modified cellulose fibers have cellulose I crystal structure.