PROCESS FOR PRODUCING ACRYLIC ACID, AND PROCESS FOR PRODUCING HYDROPHILIC RESIN AND PROCESS FOR PRODUCING WATER ABSORPTIVE RESIN USING THE PROCESS

摘要

[Problem];There is provided, in a process for producing acrylic acid having a catalytic gas-phase oxidation reaction step, a condensation step, a collection step, a distillation step, a crystallization step, an acrylic acid recovering step or the like, a production method for acrylic acid, in which contamination of acrylic acid with protoanemonin without providing any additional purification treatment to the resultant purified acrylic acid can be reduced.;[Solution];The problems described above can be solved by providing the production method for acrylic acid comprising A) a step obtaining an acrylic acid-containing gas by a catalytic gas-phase oxidation reaction of gas containing a acrylic acid raw material; B) a step of obtaining the acrylic acid-containing solution by introducing the acrylic acid-containing gas to the collection column or the condensation column and performing collection or condensation; C) a step of obtaining the crude acrylic acid by introducing the acrylic acid-containing solution to the distillation column or the crystallizer and performing distillation or crystallization, wherein a step of heat treating the acrylic acid-containing solution or the crude acrylic acid containing 100 ppm by mass or more of protoanemonin, under the condition of 100°C or more of temperature, 1 hour or more of time and a step of introducing the heat-treated acrylic acid-containing solution or the crude acrylic acid to the collection column, the condensation column, the distillation column or the crystallizer, are included.