Dsm IP Assets B.v.

Juul Cuijpers

Paulus Franciscus Anna Buijsen

Johannes Albertus Hettinga

Jurjen Bolks

Rubin Huang

Jean-Paul Van Bregt

Paulus Franciscus Anna Buijssen

Johannes Marius Paauwe

Cinderella Posthuma-Van-Tent

Hendrik Johannes Verhoef

Marcellinus Hermanus Johannes Schutte

Van Jean-Paul Bregt

Cornelis Johannes Barthelomeus Van Bergt

Cinderella Posthuma Van Tent

The invention relates to a resin composition comprising at least an organophosphorous compound and a branched amorphous carboxylic acid functional polyester, said polyester having a Tof at least 40&#xb0; C., said polyester comprising at least 1 to 45% mol of 2,2-dimethyl-1,3-propanediol; a Cto Caliphatic diol AD1 not including 2,2-dimethyl-1,3-propanediol; a Cto Caliphatic or cycloaliphatic diol AD2; 0.1 to 10% mol of an at least trifunctional monomer; 1 to 55% mol of terephthalic acid, wherein the % mol is based on the polyester. The powder coatings of the present invention derived upon curing at low temperature of the thermosetting powder coating compositions of the invention that were storage stable and comprised said resin composition and a crosslinker having functional groups that are reactive with the carboxylic acid groups of the polyester, have limited or no blooming, good smoothness sufficient reverse impact resistance and preferably have also good degassing limit.

Resin compositions for thermosetting powder coating compositions

The invention relates to a thermosetting powder coating composition comprising a crosslinker and a polyester, wherein the polyester has functional groups which functional groups are capable of reacting with &#x3b2;-hydroxyalkylamide groups, wherein the polyester is prepared from at least the following monomers: neopentylglycol, a difunctional alcohol other than neopentylglycol; isophthalic acid, terephthalic acid, optionally adipic acid and a branching monomer chosen from the group of an at least trifunctional carboxylic acid, an at least trifunctional alcohol, an at least trifunctional hydroxy carboxylic acid and mixtures thereof, wherein the amount of difunctional alcohol other than neopentylglycol in the polyester ranges from 1 to 50% w/w based on the polyester, wherein the amount of isophthalic acid in the polyester ranges from 6 to 35% w/w based on the polyester, wherein the polyester has a functionality of at least 2.1, wherein the crosslinker is a compound having &#x3b2;-hydroxyalkylamide groups. This thermosetting powder coating composition has the ability to be cured at low temperature, while at the same time being able provide powder coatings having at least two of the following three properties: limited blooming to no blooming, an acceptable smoothness, sufficient impact resistance.

Powder coating composition comprising a polyester and a &#x3b2;-hydroxyalkylamide as crosslinker

The invention relates to a carboxylic acid functional branched polyester for thermosetting powder coating composition, wherein said polyester is prepared from at least the following monomers: a difunctional aromatic acid, the difunctional aromatic acid being a combination of terephthalic acid (TPA), isophthalic acid (IPA), an at least trifunctional monomer and a difunctional alcohol, the difunctional alcohol being a combination of at least ethylene glycol (EG) and/or diethylene glycol (DEG) and neopentyl glycol (NPG), the molar ratio of TPA to IPA in the carboxylic acid functional branched polyester is at most 12.4, and the functionality of the carboxylic acid functional branched polyester is from 2.15 to 4.0, and the carboxylic acid functional branched polyester has an acid value of from 14 to 80 mg KOH/g resin, and the carboxylic acid functional branched polyester has a glass transition temperature of at least 40C. The powder coating compositions of the present invention derived upon curing of the thermosetting powder coating compositions which comprise the polyester according to the invention together with a crosslinker with oxirane groups and an epoxy cure catalyst present good corrosion resistance to steel substrates. Furthermore, said low cost and corrosion resistant powder coatings may present good reverse impact resistance (RIR) and/or good smoothness.

Powder coating composition comprising a polyester and a crosslinker with oxirane groups providing improved corrosion resistance to a substrate coated therewith

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Zwolle, Netherlands

Juul Cuijpers