PRODUCTION OF AQUEOUS SOLUTION OF CATIONIC THERMOSETTING RESIN

摘要

PURPOSE:To obtain the titled aqueous solution having high solid concentration and excellent effect to improve paper strength in wet state, by reacting a polyalkylenepolyamine with an aliphatic dicarboxylic acid at a specific ratio and reacting the resultant polyamide polyamine with a specific amount of epichlorohydrin. CONSTITUTION:A polyalkylenepolyamine (e.g. diethylenetriamine) is mixed with an aliphatic dicarboxylic acid (e.g. oxalic acid) at a molar ratio of 1.0:(0.9-1.1) and subjected to dehydrative condensation by heating at 135-150 deg.C to obtain a polyamide polyamine having a viscosity of 300-600cps measured by Brookfield viscometer as 50% aqueous solution. An aqueous solution of the polyamide polyamine having a concentration of 20-50% is mixed with 1.2-2.0 equivalent of epichlorohydrin based on the amino group of the polyamide polyamine and the components are made to react with each other until the viscosity of 20% aqueous solution of the product reaches 30-200cps (measured under the above condition) to obtain the objective aqueous solution. The solution is useful as a fixing resin for wet paper strengthening agent, sizing agent and filler.