| 摘要 |
<p>1504087 Anhydrous Na 2 S 2 O 4 MITSUI TOATSU CHEMICALS Inc 19 May 1976 [21 May 1975 (2)] 20659/76 Heading C1A Anhydrous Na 2 S 2 O 4 is prepared in a cyclic process from HCOONa, NaOH and H 2 SO 3 (anhydride) in aqueous MeOH, separating the Na 2 S 2 O 4 and cooling the remaining reaction mixture to + 5‹ to -30‹ C. to precipitate Na 2 S 2 O 3 , which is removed by filtration, the filtrate being recycled to the reaction mixture for the preparation of further Na 2 S 2 O 4 .</p> |
