GB364304A - Improvements in and relating to resinous compositions - Google Patents

Abstract

Phenol-aldehyde condensation products.--A phenolaldehyde condensation product, which is permanently liquid at ordinary temperature but which solidifies on heating, is produced by condensing a phenol and an aldehyde in presence of an ethanolamine, such as mono-, di- or triethanolamine, a dispersing agent, and urea the reaction mixture being rapidly heated and subsequently rapidly cooled. As dispersing agents are mentioned alkali iodides, bromides, chlorides, nitrates and sulphates, sodium benzoate, salicylate formate and citrate, potassium tartrate and calcium chloride. The aldehyde is preferably used in the solid form, but the commercial liquid can also be used. In an example 30 parts of cresol, 18 parts of paraformaldehyde, 2 parts of triethanolamine, 1 part of potassium bromide, 0,5 part of urea and 0,5 part of guanidine carbonate are rapidly heated to 95-100 DEG C. and then rapidly chilled to room temperature. The liquid product, to which fillers may be added, is stable, but gels at 80 DEG C. in an hour and is fully hardened at 105 DEG C. or higher in 20 hours. The liquid product may be used to impregnate an article such as an electric coil, which is warmed, dipped into the cold or warmed liquid and finally heated; the impregnation may be effected in an evacuated chamber, pressure being applied after the liquid is admitted. Specification 302,609, [Class 2 (iii), Dyes &c.], is referred to. The Specification as open to inspection under Sect. 91 (3) (a) refers to guanidine carbonate as an alternative to urea and uses the expression "a urea body." This subject-matter does not appear in the Specification as accepted.ALSO:A phenol-aldehyde condensation product which is permanently liquid at ordinary temperature but which solidifies on heating, is produced by condensing a phenol such as mono-, di- or triethanolamine and an aldehyde in presence of an ethanolamine, a dispersing agent, and urea, the reaction mixture being rapidly heated and subsequently rapidly cooled. As dispersing agents are mentioned alkali iodides, bromides, chlorides, nitrates and sulphates, sodium benzoate, salicylate, formate, and citrate potassium tartrate and calcium chloride. The aldehyde is preferably used in the solid form but the commercial liquid can also be used. In an example 30 parts of cresol, 18 parts of paraformaldehyde, 2 parts of triethanolamine, 1 part of potassium bromide, 0,5 part of urea, and 0,5 part of guanidine carbonate are rapidly heated to 95-100 DEG C. and then rapidly chilled to room temperature. The liquid product to which fillers may be added is stable, but gels at 80 DEG C. in an hour and is fully hardened at 105 DEG C. or higher in 20 hours. The liquid product may be used to impregnate an article such as an electric coil, which is warmed, dipped into the cold or warmed liquid and finally heated; the impregnation may be effected in an evacuated chamber, pressure being applied after the liquid is admitted. Specification 302,609, [Class 2 (iii), Dyes &c.], is referred to. The Specification as open to inspection under Sect. 91 (3) (a) mentions guanidine carbonate as an alternative to urea, and uses the expression "a urea body." This subject-matter does not appear in the Specification as accepted.