Cement mortar additive for extrusion molding, cement mortar for extrusion molding, and extrusion-molded product

A cement mortar for extrusion molding comprising a cement and a cement mortar additive for extrusion molding comprising hydrogelated cellulose ether:

• wherein the hydrogelated cellulose ether is formed via chemical reaction between water-soluble cellulose ether or raw materials of the water-soluble cellulose ether and at least one of an association agent and a crosslinking agent,
• wherein the water-soluble cellulose ether is selected from methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, carboxymethylcellulose, and a mixture of at least two thereof,
• wherein the association agent is a C10-C24 alkyl glycidyl ether, a C10-C24 alkyl halide, a halo hydride, or a mixture thereof,
• wherein the crosslinking agent is selected from 1,2-dichloroethane, 1,3-dichloropropane, 1,4-dichlorobutane, 2,2′-dichlorodiethylether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, polyglycerol polyglycidyl ether, digylcerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylpropane polyglycidyl ether, 1,2-(bis(2,3-epoxypropoxy)ethylene, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether, divinyl sulfone, glycidyl methacrylate, epichlorohydrin, epibromohydrin, or a mixture of at least two thereof,
• wherein, when mixed with water, the hydrogelated cellulose ether forms a colloidal gel instead of being dissolved in water.