Unsaturated Polyester Resins Particularly Adapted for the Manufacture of Buttons

摘要

A process for the preparation of solid, non compactable unsaturated polyester resins comprises reacting, in a first stage, neopentylglycol or 1,4- butanediol or a mixture thereof, with dimethylterephthalate at 140- 190 DEG C, until the reaction is completed and in a second stage, the product thus obtained is reacted with fumaric acid or maleic anhydride in the presence of a solvent at about 200 DEG C until an acid number of preferably 12-13 is reached. The alkyd is milled and mixed with diallylphthalate and conventional accelerators and catalysts.