Abstract: A fibrous cellulose composite resin having high strength, and a method for producing the same is provided. The fibrous cellulose composite resin contains a fibrous cellulose and resin, wherein the fibrous cellulose is carbamated microfiber cellulose having hydroxy groups partially or fully substituted with carbamate groups, and having a Fines A of 25% or higher and a percentage of fibrillation of 1.0% or lower. The method for producing the fibrous cellulose composite resin includes subjecting raw material pulp to papermaking to obtain a strip-shaped pulp sheet, coating the pulp sheet with at least either of urea and a derivative thereof, followed by heating, to prepare a carbamated pulp sheet, defibrating the carbamated pulp sheet into carbamated microfiber cellulose having a Fines A of 25% or higher and a percentage of fibrillation of 1.0% or lower, and kneading the carbamated microfiber cellulose and resin.

Abstract: A method for preparing carbamated cellulose fibers applicable to mass production is provided. The method for preparing carbamated cellulose fibers in which hydroxyl groups of cellulose fibers have partially or fully been modified with carbamate groups, includes heating a pulp sheet which has been formed into a strip shape by subjecting a raw material pulp to papermaking and contains urea or a derivative thereof, between a pair of rolls while passing therebetween, to cause the modification.

Abstract: Provided is a method for preparing carbamated cellulose fibers or carbamated cellulose fine fibers, having a higher brightness, without impairing reinforcing effect of the fibers on resin. The method includes adding a bleaching agent to carbamated cellulose fibers, and bleaching the carbamated cellulose fibers with the bleaching agent at a reaction temperature of 90 degrees or lower at pH 7 or lower. Carbamated cellulose fibers obtained from this method and having 0.5 mmol/g or more carbamate groups introduced therein are made finer so that the resulting carbamated cellulose fine fibers have an average fiber width of 0.1 to 20 ?m, an average fiber length of 0.1 to 2.0 mm, and a fine percentage A of 10 to 90%.

Abstract: A method for producing a cellulose fiber-containing material, a method for producing reacted cellulose fibers, and a method for producing reacted fine fibers, applicable to mass production, are provided. The method for producing cellulose fiber-containing material P2 for use as cellulose fibers containing a reaction agent for obtaining reacted cellulose fibers P3 from cellulose fibers containing the reaction agent, includes subjecting raw material pulp to papermaking to obtain a strip-shaped pulp sheet having a Cobb sizing degree of 10 to 600 g/m2 as measured in accordance with JIS P 8140, and coating the pulp sheet with the reaction agent. Using the cellulose fiber-containing material P2 thus obtained, reacted cellulose fibers P3 are produced by reacting the reaction agent with the cellulose fibers. Reacted fine fibers P4 are produced by making the ash content of raw material pulp P1 to 20 mas % or lower and defibrating the reacted cellulose fibers P3.

Abstract: A method for preparing carbamated cellulose fibers applicable to mass production is provided. The method for preparing carbamated cellulose fibers in which hydroxyl groups of cellulose fibers have partially or fully been modified with carbamate groups, includes heating a pulp sheet which has been formed into a strip shape by subjecting a raw material pulp to papermaking and contains urea or a derivative thereof, between a pair of rolls while passing therebetween, to cause the modification.

Abstract: A fibrous cellulose-containing material having excellent dispersibility even when dried, a method for preparing the same, and a fibrous cellulose composite resin having excellent strength. The fibrous cellulose-containing material is for addition to resin, and contains fibrous cellulose having an average fiber width of 0.1 to 19 ?m and having hydroxyl groups partially or fully substituted with carbamate groups, and interactive powder that is interactive with the fibrous cellulose. The fibrous cellulose composite resin contains the fibrous cellulose-containing material as fibrous cellulose. The method for preparing a fibrous cellulose-containing material includes defibrating fibrous cellulose having hydroxyl groups partially or fully substituted with carbamate groups to have an average fiber width of 0.1 to 19 ?m, and mixing with interactive powder that is interactive with the fibrous cellulose to obtain a mixed liquid, and drying the mixed liquid.