PREVENTION DEPOSITION OF FUMARIC ACID IN AQUEOUS SOLUTION OF MALIC ACID

摘要

PURPOSE: To prevent deposition of fumaric acid in an aqueous solution of malic acid over a long period even at low temperature so as to enable preferable utilization of the aqueous solution of malic acid to a liquid toiletry commercial product, etc., by adding a small amount of specific base to a high concentration aqueous solution of malic acid containing fumaric acid. ;CONSTITUTION: A small amount of (B) a base [e.g. sodium hydroxide, ammonium hydroxide, sodium (hydrogen) carbonate or ammonium (hydrogen) carbonate] capable of forming a water-soluble salt of a component (A) an aqueous solution of a high concentration of malic acid (A₃) containing maleic acid (A₂) and fumaric acid (A₁) in a concentration capable of readily being deposited during storage from ordinary temperature to a low temperature, e.g. a solution of the A₃ obtained by carrying out a hydration reaction of the A₁ or the A₂ followed by chilling to remove deposited A₁ crystals, to prevent the deposition of fumaric acid (A₁) in the solution A. Furthermore, A₃ concentration in the component A is preferably 30-55wt.% and the amount of the component B added is ≥0.5 equivalent based on an amount necessary for the neutralization of A₁ and A₂ and corresponds to an amount by which a monosalt of the component A₃ does not cause deposition.;COPYRIGHT: (C)1996,JPO