Production process for water-absorbent resin
AssigneeNippon Shokubai Co., Ltd.
InventorsYukihiro Matsumoto, Kunihiko Ishizaki, Teruyuki Kanto
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Abstract
The present invention provides a process for producing a water-absorbent resin of which the residual monomer content and the extractable content are low. The process for producing a water-absorbent resin comprises the step of polymerizing at least one monomer component including acrylic acid and/or its salt as major components to produce a water-absorbent resin that is a neutralized salt, and this process is characterized in that the acrylic acid is a product obtained by catalytic gas phase oxidation of propylene and/or propane and has a protoanemonin content of not more than 10 ppm, and in that the resultant water-absorbent resin has a neutralization ratio of not less than 50 mol %.
Claims9
A process for producing a water-absorbent resin, which comprises the step of polymerizing at least one monomer component including acrylic acid and/or its salt as major components to produce a water-absorbent resin that is a neutralized salt, with the process being characterized in that the acrylic acid is a product obtained by catalytic gas phase oxidation of propylene and/or propane and has a protoanemonin content of not more than 10 ppm, and in that the resultant water-absorbent resin has a neutralization ratio of not less than 50 mol %.
A process for producing a water-absorbent resin, which comprises the step of polymerizing at least one monomer component including acrylic acid and/or its salt as major components to produce a water-absorbent resin that is a neutralized salt, with the process being characterized in that the acrylic acid used as a raw material is a product being obtained by catalytic gas phase oxidation of propylene and/or propane and containing an aldehyde, and further characterized by further comprising the step of subjecting the raw acrylic acid to a strong-alkali treatment followed by the polymerization step.
Dependencies are inferred from the claim text.