FLEXIBILIZED POLYASPARTIC ESTERS

摘要

Provided are a method for preparing polyaspartate which has a suitable reactivity to isocyanate and a low viscosity and can form a coated product having a low crosslinking density and an excellent physical property, its polyaspartate, and a coating composition containing the polyaspartate. The method comprises the steps of ester exchange reacting an alpha,beta -unsaturated ester represented by R1OOC-C(R3)=C(R4)-COOR2 and a hydroxyl functional compound containing n hydroxyl groups per a molecule and having a number average molecular weight of about 62-3,000 in a molar ratio of n to (n+8) : 1 (wherein n is 2-8); reacting the obtained product with at least 1 mol of a compound containing at least one primary amine group per the alpha,beta-unsaturated ester; and reacting an arbitrary first amine group with the alpha,beta-unsaturated ester of the formula 1, wherein R1 and R2 are identical or different each other and are an organic group inert to an isocyanate group at a temperature of 100 deg.C or less; and R3 and R4 are identical or different each other and are H or an organic group inert to an isocyanate group at a temperature of 100 deg.C or less.