2,2-bis(hydroxymethyl)butyric acid is a good crosslinking agent and hydrophilic agent, or used to produce water-based high molecule system, is widely used in water soluble PU system, polyester resin and epoxy ester. With good solubility, it also is widely used in coating of water soluble PU system, adhesive and leather coating agent.. It will become a new kind of environment-friendly substitute of 2,2-Bis(hydroxymethyl)propionic acid.
In a 1000 ml four-necked flask add 96 grams of paraformaldehyde, 96 grams of water, start stirring, temperature, at about 50 degrees dropwise addition of 80 grams of content of 5
% liquid alkali, control pH between 9-10 in 2 hours dropwise addition is completed, continue to hold the reaction for 4 hours, raise the temperature to 80 C to recover not fully reacted n-butyraldehyde, as well as a small amount of formaldehyde solution, endothermic steaming to 100 degrees Celsius, stop the distillation, lower the temperature, control at about 50 degrees Celsius, and slowly dropwise addition of 220 grams content of 27
% of hydrogen peroxide, control the completion of the drop in 2 hours, after the completion of the drop, insulation reaction for 6 hours, add concentrated sulfuric acid acid, reduce pressure to 12 kPa evaporation of water, evaporation, add methyl isobutyl ketone 200 grams of reflux to 100 reflux division of water, after the division of water, lower the temperature, filtration of solid salts while hot, the filtrate is further cooled down, precipitation of crystals, get crude, the crude is added to the solvent to carry out a further The crude product was added into the solvent and recrystallized to obtain white crystals, and the total yield of 2,2-dihydroxymethylbutyric acid was 41%.
