| 摘要 |
1,272,016. Curing phenolic resins. DYNAMIT NOBEL A.G. 6 June, 1969 [6 June, 1968], No. 28893/69. Headings C3C and C3R. A curing agent for a liquid resole comprises a free-flowing mixture of (a) a solid organic sulphonic acid or a solid strong halogen-substituted organic acid and (b) a finely divided inert solid diluent, which mixture has an average particle size of 10-50 mÁ. The acid may be propyl sulphonic, butyl sulphonic, hexyl sulphonic, benzene sulphonic, p-toluene sulphonic, o-, m- or p-cresol sulphonic, bromobenzene-4-sulphonic, naphthol sulphonic, a polynuclear aromatic sulphonic acid, chlorobenzene-3,5-disulphonic or trichloroacetic acid. The diluent may be silica, activated charcoal, bentonite, boric acid or boric oxide. The resole may be prepared from phenol, a cresol, a xylenol, resorcinol or pyrocatechol and formaldehyde, paraformaldehyde, trioxane, hexamethylene tetramine, acetaldehyde or furfural in the presence of NaOH. The curing reaction may be conducted at elevated temperature. In examples foamable resoles are cured in the presence of n-pentane and ethoxylated castor oil as pore-regulator. |
