In the production of the powder water absortion power resin with the converse suspension polymerization of acrylic monomer the improvement

摘要

PURPOSE: To industrially obtain the subject product having a large particle size and excellent in water absorbing performance in high productivity by using a specified suspending agent in a first stage of polymn. when acryl monomers are subjected to a two-stage radical polymn. in an inverse suspension liquid. ;CONSTITUTION: First, a surfactant expressed by the formula which is radically polymerizable and disappears from its medium by copolymn. when the first stage polymn. is completed is used to introduce an aq. phase containing water- soluble unsatd. monomers (preferably acrylic acid) in a hydrocarbon solvent phase to carry out the first stage polymn. In the formula, R₁ is a ≥9C hydrocarbon chain; R₂ is (meth)acryloyl or maleoyl; (n) is 30 to 70. Then the produced gel is made to absorb the aq. phase of water-soluble unsatd. monomers to carry out the second stage polymn. The produced polymer is separated, and usually, the polymer is dried to obtain the objective product. As for the surfactant expressed by the formula, a maleic acid monoester of nonylphenol or the like which is converted into an oxyethylene with 50 molecules of ethylene oxide is preferably used.;COPYRIGHT: (C)1994,JPO