Patent GB-345276-A (GB)
Title: Improvements in and relating to synthetic resin varnishes and synthetic resins
IPC: C08G8/08
Filed: 1929-09-13
Abstract: Phenol-aldehyde condensation products soluble not only in alcohols and ketones but also in hydrocarbons, esters including fatty-acid esters and turpentine are made by causing metaxylenol or its isomers or mixtures of the same, or the distillates from the phenolic fraction of coal-tar boiling from 215-224 DEG  C. to react with formaldehyde by heating the reactants in the presence or absence of an acid condensing agent, but avoiding the use of alkali.  Preferably a substantial quantity of a volatile organic solvent of a non-film-forming character is present as a restrainer of the vigorous exothermic reaction.  The solvent is removed by distillation and the residue heated up to 120 DEG  C. until a test portion cools to a hard residuous bead.  This product may be dissolved in solvent naphtha or other solvent or in a fatty-acid ester and the product mixed into driers to form a varnish.  The resinous product may also be heated with drying oils to form varnishes containing also driers and suitable solvents.  According to the examples, the parts being by weight, (1) 976 parts of mixed xylenols, 150 parts of formaldehyde and 30 parts of concentrated hydrochloric acid are mixed in 1,000 parts of methyl alcohol and the mixture boiled for 20 hours.  The product is distilled until the temperature in the liquid is about 120 DEG  C., the distillation being continued until the residue forms a hard resin on cooling. The resin may be dissolved in alcohol, or solvent naphtha or other organic solvent or in a drying oil and used as a varnish. (2) 30 grams of mixed xylenols, 4,6 grams of aqueous formaldehyde, and 0,9 grams of concentrated hydrochloric acid are mixed in 25 ccs. of methylated spirit, the mixture boiled, then distilled and dissolved in a solvent or drying oil according to the preceding example.  (3) and (4) a resin prepared as in either of the previous examples is dissolved in an equal weight of raw tung oil or thickened linseed oil and the solvent heated for two hours.  The product is a plastic resin which may be dissolved in naphtha or other solvent and driers added to form an air-drying varnish.ALSO:Phenol-aldehyde condensation products soluble not only in alcohols and ketones but also in hydrocarbons, esters including fatty acid esters, and turpentine are made by causing metaxylenol or its isomers or mixtures of the same, or the distillates from the phenolic fraction of coal-tar boiling from 215-224 DEG  C. to react with formaldehyde by heating the reactants in the presence or absence of an acid condensing agent, but avoiding the use of alkali. Preferably a substantial quantity of a volatile organic solvent of a non-film-forming character is present as a restrainer p  of the vigorous exothermic reaction.  The solvent is removed by distillation and the residue heated up to 120 DEG  C. until a test portion cools to a hard residuous bead.  This product may be dissolved in solvent naphtha or other solvent or in a fatty acid ester and mixed into driers to form a varnish.  The resinous product may also be heated with drying oils to form varnishes containing also driers and suitable solvents.  According to the examples, the parts being by weight, (1) 976 parts of mixed xylenols, 150 parts of formaldehyde and 30 parts of concentrated hydrochloric acid are mixed in 1,000 parts of methyl alcohol and the mixture boiled for 20 hours.  The product is distilled until the temperature in the liquid is about 120 DEG  C., the distillation being continued until the residue forms a hard resin on cooling. The resin may be dissolved in alcohol, or solvent naphtha or other organic solvent or in a drying oil and used as a varnish.  (2) 30 grams of mixed xylenols, 4-6 grams of aqueous formaldehyde, and 0,9 grams of concentrated hydrochloric acid are mixed in 25 c.c. of methylated spirit, the mixture boiled, then distilled, and dissolved in a solvent or drying oil according to the preceding example.  (3) and (4) a resin prepared as in either of the preceding examples is dissolved in an equal weight of raw tung oil or thickened linseed oil and the solvent heated for two hours. The product is a plastic resin which may be dissolved in naphtha or other solvent and driers added to form an air-drying varnish.