GB878168A - Method of and compositions for reducing foaming of aqueous liquids when boiled - Google Patents

Abstract

Condensation products are prepared by condensing 5-30 molecular proportions of ethylene oxide with one molecular proportion of a dioxide with one molecular proportion of a diamide R CO NH (CH2)n N CO R1 or R NH CO (CH2)n CO NH R where R and R1 are straightchain alkyl groups of 10-30 carbon atoms and n is a positive integer from 2-15. Exemplified diamides are N, N1-bisoctadecanyl sebacamide, N, N1 bis stearoyl ethylene diamine, N, N1-bispalmitoyl ethylenediamine, N, N1-bis-stearoyl hexamethylene diamine. The product can be used alone or mixed with the sodium salt of a condensation product of naphthalene sulphonic acid with formaldehyde, ethylene diamine tetra-acetic acid, or nitrilo triacetic acid as a defoaming agent.ALSO:The condensation product of 5 to 30 molecular proportions of ethylene oxide with one molecular proportion of a diamide RCONH(CH2)nNHCOR1 or RNHCO(CH2)nCONHR1 where R and R1 are straight-chain alkyl groups of 10 to 30 carbon atoms and n is a positive integer from 2 to 15 is a water defoamant useful in quantities of from 0.1 to 50 parts/million. Exemplified diamides are N,N1 - bisoctadecanyl sebacamide, N,N1 - bis - stearoy ethylenediamine, N,N1-bispalmutoyl ethylenediamine, N,N1 - bis - stearoyl hexamethylene diamine. The product may be admixed with the sodium salt of a condensation product of naphthalene sulphonic acid with formaldehyde, ethylene diamine tetraacetic or nitrils triacetic acid.