GB613073A - Improvements in or relating to moulding compositions and to moulded articles made therefrom - Google Patents

Abstract

A moulding composition is produced by heating a mixture of blown drying or semidrying oil and heat-reactive phenolic resin until the viscosity begins to increase rapidly and then inhibiting gelation by incorporating a plasticizer and/or a non-heat reactive resin. Fillers or pigments may be added and the product moulded, e.g. to form building construction units such as flooring tiles. The reaction of the oil with the resin may be catalysed by a mixture of boric and oxalic acid, metal resinates, oleates, benzoyl peroxide, a metal such as cobalt colloidally dispersed in an oil-miscible medium, maleic acid, boric acid, benzoic acid, citric acid, oxalic acid, tartaric acid, succinic acid or lactic acid. Suitable oils are linseed, tung, dehydrated castor, soybean, or china wood oil. Suitable heat-reaction resins are obtained by alkaline condensation of formaldehyde with a p-alkyl phenol. Examples are described in Specification 507,770. Suitable non-heat-reactive resins are colophony, coumarone resins, indene-type resins, ester gums, hard petroleum residues and residue pitches. Suitable plasticizers are butyl phthalate, tri-cresyl phosphate, soft petroleum residues, whale oil pitch and residue pitches. Fibrous fillers are, for example, sawdust or asbestos fibres. Other suitable fillers are whiting, ground limestone, slate dust, silica flour, titanium dioxide or iron oxides. In example (1), blow linseed oil was heated, a heat-reactive phenol-formaldehyde resin added followed by a mixture of oxalic and boric acids, and heating continued until viscosity increased. A molten mixture of coumarone-indene resin and a petroleum aromatic residue was stirred in, followed by short asbestos fibre, whiting, titanium dioxide and pigment. The mixture was formed into sheets. Examples (2), (3) are similar, using a mixture of coumarone-indene resin and stearin pitch to stop gelation and using hardwood sawdust in place of asbestos fibres.