... Water Treatment Chemicals. Amino Trimethylene Phosphonic Acid (ATMP)2-Phosphonobutane -1,2,4-Tricarboxylic Acid(PBTCA)CAS No. 37971-36- ... 0.8 maxPhosphorous acid(as PO43-)%0.5 maxDensity (20°C) g/cm31.27 minpH(1% water solution)1.5~2.0Fe ... ;PHOSPHONOBUTANE TRICARBOXYLIC ACID;2-Phosphonobutane -1,2,4-Tricarboxylic Acid;2-Phosphonobutane-1,2,4-tricarboxylic acid PBTC; 2-Phosphonobutane -1,2,4 ...