Isobutyraldehyde-phenol! resins - made by condensing the components using an acid catalyst and distilling off the unused aldehyde

摘要

Isobutyraldehyde-phenol polycondensates are made by condensing isobutyraldehyde (I) with a phenol (II) in a ratio (I)/(II) of 0.6-0.9:1, in the presence of an acid catalyst comprising a phosphorus halide, H2SO4, an aromatic acid or HCl. Excess (I) is then distilled off. The reaction is carried out either by adding the (I) gradually to the (II) according to the conversion, until excess (I) has been added, or the (I) and anII) are added simultaneously to the reactor or are previously mixed. Use of the stated catalysts and conditions allows poly-condensates of (I) and (II) to be made without the formation of large amts. of low molecular material, as in previous processes. The prods. are useful tackifiers in unvulcanised (natural)rubber, as components in adhesives, as sand core binders and as binders for wood fibre boards.