Powder paint binder composition

Abstract

The invention relates to a powder paint binder-composition comprising a polymer that contains endomethylene tetrahydrophthalic acid units and a crosslinker. The polymer has been 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 polyester.

1 . A curable powder paint binder composition comprising a polymer comprising endomethylene tetrathydrophthalic acid units and a crosslinker.  
     
     
         2 . A composition according to  claim 1 , characterized in that the polymer has been obtained by first preparing an unsaturated polymer which is subsequently reacted with cyclopentadiene at a temperature between 160° C. and 220° C.  
     
     
         3 . A composition according to any one of claims  1 - 2 , characterized in that the polymer contains at least 10 wt. % endomethylene tetrathydrophthalic acid units.  
     
     
         4 . A composition according to any one of claims  1 - 3 , characterized in that the polymer is an unsaturated polyester.  
     
     
         5 . A composition according to  claim 4 , characterized in that the unsaturated polyester is built up of fumaric acid units, maleic acid units and/or terephthalic acid units and of ethylene glycol units; polypropylene glycol units and/or neopentyl glycol units.  
     
     
         6 . A composition according to any one of claims  1 - 5 , characterized in that the crosslinker is triglycidyl isocyanurate or bisphenol-A epoxy resin.  
     
     
         7 . A compositions according to any one of claims  1 - 6 , characterized in that the endomethylene, tetrahydrophtalic acid units containing polymer contains virtually no lineair alkyl chains with more than 5 carbon atoms.  
     
     
         8 . A powder paint composition comprising a binder composition according to any one of claims  1 - 7  and optionally pigment, catalyst, fillers and additives.  
     
     
         9 . A powder coating obtained after curing of a powder paint composition according to  claim 8 .  
     
     
         10 . Wholly or partly coated substrate, characterized in that as coating a powder coating according to  claim 9  has been used.