Patent GB-698353-A (GB)
Title: Synthetic resins capable of binding organic atom complexes and process for preparing same
IPC: C13B20/14
Filed: 1951-02-13
Abstract: A synthetic adsorption resin is prepared by condensing meta-phenylene diamine, either alone or with other condensable substances such as resorcinol and amino-compounds, with an aldehyde in aqueous acid medium, the proportions of the reactants and acid and the quantity of water being such that the volume of the resin when dried to constant weight is at least 25 per cent, preferably 30-70 per cent of the volume of the freshly condensed undried resin, the volume ratio being determined by the method described in the Specification.  After condensation the resins need not but are preferably dried to reduce their bulk as far as possible.  The resins have little or no ion-exchange properties. Acids specified are nitric, sulphuric, phosphorus, hydrohalic, trichloroacetic and phthalic.  Figures are given for the requisite proportions of formaldehyde and water per gram mole. of meta-phenylene diamine when using hydrochloric, nitric, sulphuric and phosphoric acids.  If a modifying reactant is present, this should not exceed one gram mole. per gram mole. of meta-phenylene diamine.  Specified modifying agents are polyethylene amines, resorcinol, melamine, toluidine, dicyandiamide, triethanolamine, aniline, urea.  In examples (1) metaphenylene diamine and formaldehyde are condensed in aqueous nitric acid in varying proportions to give (a) a resin of volume ratio 17.8 per cent and (b) a resin of volume ratio 43 per cent. The decolourizing of sugar solutions by the two resins are compared; (2) meta-phenylene diamine, resorcinol and formaldehyde were condensed in hydrochloric acid to give a resin of volume ratio 22 per cent.  A similar resin of volume ratio 57 per cent was also prepared and the decolourizing properties compared using sugar syrups.  The Specification also describes resins from (a) m-phenylene diamine, m-toluidine and formaldehyde in nitric acid and in sulphuric acid with varying quantities of water; (b) m-phenylene diamine, acetaldehyde and formaldehyde in nitric acid; (c) m-phenylene diamine and crotonaldehyde in nitric acid; (d) m-phenylene diamine and formaldehyde in aqueous tri-chloracetic acid; (e) m-phenylene diamine and formaldehyde in aqueous phthalic acid.  For comparison the volume ratios of certain resins described in U.S.A. Specifications 2,106,486, 2,261,021 and 2,290,345 and French Specification 875,743 are given.ALSO:The Specification refers to the complete absorption of n-propyloxy-1-amino-2-nitro-4-benzene from aqueous solution by an adsorption resin gel prepared from metaphenylene diamine, formaldehyde and nitric acid; (see Group IV (a)).  The compound could easily be eluted from the resin with benzene or ether.ALSO:Sugar solutions are decolorised by percolation through an absorption resin which is the reaction product of metaphenylene diamine (with or without other condensible substances such as phenols and amino compounds) with an aldehyde condensed in an aqueous acid medium, the proportions of the reactants being such that the volume of the resin dried to constant weight is at least 25 per cent, preferably 30-70 per cent of the volume of the freshly condensed undried resin (see Group IV (a)).  The regeneration of the resins is effected in the usual way with bases and acids.  In example (1) two samples of syrup with a colour of 433.8 per 100 grams of dry substance (Lovibond tintometer) were separately percolated through a metaphenylene diamineformaldehyde resin according to the invention having a volume ratio of 43 per cent and a similar resin of volume ratio 17.8 per cent.  In the first case 98.53 per cent of colour was eliminated and in the second 26.53 per cent.  Example (2) is similar to example (1) using resins from metaphenylene diamine, resorcinol and formaldehyde, with decolorisations of 99.8 per cent and 24.1 per cent.  Further examples describe other resins according to the invention.