| 摘要 |
PURPOSE:To obtain the title water-retentive agent which exhibits an excellent effect of retaining water and a liquid and can be efficiently absorbed by a plant, by polymerizing a mixture of a (meth)acrylic ester monomer and a carboxylated unsaturated monomer. CONSTITUTION:A monomer mixture comprising 20-80wt.% (meth)acrylic ester monomer (A) of the formula (wherein R is H or CH3; C is 2-4C oxyalkylene having a mol fraction of oxyethylene to total oxyalkylene of at least 50%; Y is 1-5C alkoxy, phenoxy, or oxyalkylphenyl having one to three 1-9C alkyl groups as substituents; and n is 3 to 100 on average) and 20-80wt.% water-soluble carboxylated unsaturated monomer (B) is polymerized in the presence or absence of a crosslinking agent to give a water-retentive agent comprising a crosslinked polymer used for agriculture and horticulture. This water-retentive agent has a sufficient water absorption even when used in a soil containing a relatively large amount of salt, also shows a high absorption of a liquid fertilizer, and does not impair the growth of the root of a plant; therefore, the absorbed water and fertilizer can be efficiently absorbed by a plant. |
