<p>The invention relates to a powder paint composition comprising a polymer that contains endomethylene tetrahydrophthalic acid units and a crosslinker. The polymer is obtained by preparing an unsaturated polymer in a first step, which then reacts with cyclopentadiene at a temperature between 160 ° C and 220 ° C in a second step. The polymer preferably contains more than 10 wt.% endomethylene tetrahydrophthalic acid units and is preferably an unsaturated polymer.</p>