| 摘要 |
1478683 Preparing bis - [tetrakis - (hydroxymethyl)]phosphonium oxalate AMERICAN CYANAMID CO 17 Sept 1974 [18 Oct 1973] 40541/74 Heading C2P [Also in Division D1] Bis - [tetrakis - (hydroxymethyl)]phosphonium oxalate is obtained by reacting in the absence of a catalyst, at least a stoichiometric quantity of formaldehyde with substantially stoichiometric amounts of phosphine and oxalic acid at 40-75‹ C., the reaction being carried out with intimate contact of the reactants. Intimate contact may be achieved by vigorous agitation of the reactants or by using a columnar reactant and passing the phosphine in at the bottom of the column countercurrent to a liquid containing oxalic acid and aqueous formaldehyde flowing from the top of the column. An example is given in which the oxalic acid is used in its dihydrate form and the process is conducted in the defined countercurrent manner. The product is useful as a flame-retardant for cellulosic fabrics.
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