GB357259A - Improvements in or relating to compositions of matter and moulding mixtures prepared therefrom - Google Patents

Abstract

Phenol-aldehyde condensation products are made by heating a non-reactive or permanently fusible phenol-aldehyde condensation product with a neutralizing agent in solid condition, e.g. a basic oxide or hydroxide such as lime or a carbonate such as of magnesium, iron, zinc, sodium, or potassium. Sufficient amount of the agent to neutralize all free phenol is added and the heating continued till the phenolate is formed or an amount sufficient to combine with the hydroxyl groups of the resin molecule in addition may be added. The products have improved moulding properties, and moulding compounds may be produced without plasticizing the compound on the differential rolls. Asbestos may be successfully incorporated yielding a fireproof product. In an example, calcium hydroxide is boiled with a mass containing the resin and free phenol (1,25 phenolic groups to each methylene), cooled and heated with hexamethylenetetramine (paraformaldehyde, trioxymethylene, furfural, or anhydro-formaldehydeaniline) to convert to the infusible state; the pulverized product is incorporated with a fibrous filler and may be moulded in a hot press. Fats, waxes, resins, casein, pigments, &c., or a small amount of a plasticizing agent, e.g. creosote oil or furfural may be added if desired. Another example is given in which the hydroxyl groups of the resin molecule are also reacted with lime. Specifications 128,477 and 326,545, [both in Class 2 (iii), Dyes &c.], are referred to.