Method for producing modified cellulose fibers

A method of using modified cellulose fibers as an additive for a rubber composition, the modified cellulose fibers obtainable by introducing one or more compounds selected from unsaturated group-containing alkylene oxide compounds and unsaturated group-containing glycidyl ether compounds to cellulose-based raw materials in the presence of a base, via an ether bonding, and thereafter carrying out a finely fibrillating treatment,

• wherein the modified cellulose fibers are 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,
• wherein the modified cellulose fibers have cellulose I crystal structure.

A rubber composition comprising modified cellulose fibers obtainable by introducing one or more compounds selected from unsaturated group-containing alkylene oxide compounds and unsaturated group-containing glycidyl ether compounds to cellulose-based raw materials in the presence of a base, via an ether bonding, and thereafter carrying out a finely fibrillating treatment, and a rubber,

• wherein the modified cellulose fibers are 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,
• wherein the modified cellulose fibers have cellulose I crystal structure.