| 摘要 |
<p>1409821 Phosphate-buffered high-formaldehyde UF solutions WEST POINT PEPPERELL Inc 1 Sept 1972 [2 Sept 1971] 40530/72 Heading C3R [Also in Division D1] An aqueous urea-formaldehyde solution contains at least 3 mols. of formaldehyde per mol. of urea and a water-soluble inorganic phosphate as buffer. The pH is preferably 6-7.5 and suitable buffers are mono- and di-sodium or potassium phosphate; these may be added as such, or be formed in situ. Formaldehyde evolution may be further reduced by addition of a sulphite. The solution may be used to treat textiles having reactive hydrogen atoms and may contain additives conventional for this purpose. In examples urea is condensed with paraformaldehyde in 1: 4 molar ratio in the presence of Na 3 FO 4 and the solution is cooled and acidified to pH 6-6.5 with NaH 2 PO 4 ; cotton treating compositions are prepared by adding to this sodium bisulphite, alone or with acetone, NH 4 Cl or MgCl 2 or Zn(NO 3 ) 2 , and in some cases a surfactant (deca-oxyethylenated dodecanol) and softeners (polyethylene emulsion and a high ester or imidazoline emulsion) or a humectant (hydrogenated glucose), with water as necessary.</p> |
