Polyacrylic acid (salt), polyacrylic acid (salt) -based water absorbent resin and a production method thereof

Using consumer from the production process of the water absorbing resin, a polyacrylic acid (salt including the trouble of Possible various water-absorbent resin before being discarded, and go back to the production process of the water absorbent resin a verifiable way tracers ) in particular, it provides a polyacrylic acid (salt) -based water absorbent resin. The present invention is less than -20 ‰ carbon isotope ratios measured by accelerator mass spectrometry, and radiocarbon is 1.0 × 10 (1) CRC is 10 [g / g] or more, (2) AAP is 20 [g / g] or more, (3) Ext 35 wt% or less, (4) Residual Monomers is 1000ppm or less, according to (5) PSD particle size 150μm or 850μm of particles smaller than 90 weight or more, (6) FSR is 0.15 [g / g / s] or more.