| 摘要 |
PURPOSE:To obtain the titled compound, by making a slightly soluble basic alkaline earth metallic compound into finely divided solid or alcoholic suspension and adding the solid or the alcoholic suspension to a concentrated aqueous solution of formaldehyde or slurry just before solidification under cooling or during solidification under cooling and drying the solution or the slurry. CONSTITUTION:A concentrated aqueous solution of formaldehyde having <=75-<85wt% concentration is solidified under cooling and dried to give paraformaldehyde having high formaldehyde content. In the production, slightly soluble alkaline earth metallic compound (0.01-0.1wt% solubility in water) such as magnesium oxide, calcium oxide or calcium carbonate is processed into finely divided solid or suspension in a lower alcohol as a liquid medium and a small amount (about 20-100ppm, especially 40-60ppm based on paraformaldehyde) is added to the concentrated aqueous solution of formaldehyde or slurry just before solidification under cooling or during solidification under cooling and the solution or the slurry is dried.
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