| abstract |
A method for preparing pimaric acid type resin acids includes: step (1) adding refined resin acid, turpentine, or rosin along with maleic anhydride at a mass ratio of 1:0.3-1.5 into a reaction bottle, dissolving the ingredients into a C 1 -C 10 lower fatty acid solvent, the mass ratio of the C 1 -C 10 low fatty acid to refined resin acid is 0.05-30:1, then carrying out additional reaction by heating directly or with assistance of a microwave, subsequently cooling, crystallizing, filtering, and washing; and step (2) combining the filtrates collected in step (1), stripping the solvent by vacuum distillation to obtain pimaric acid type resin acid coarse product, dissolving the resulting coarse product in NaOH aqueous solution to prepare aqueous solution of pimaric acid type resin acid salt, adjusting the pH to 6-14 with a mineral acid or an organic acid, and either directly purifying or acidifying followed by purifying to obtain the final product. |