POWDER COMPOSITIONS

There is described a thermosetting and/or radiation curable powder with a binder prepared from a polyester (PE) obtained from a polyol with lower amounts of neopentyl glycol (NPG). The powder forms smooth defect free coats and is resistant to contamination from conventional NPG-rich PE. The powder comprises a binder of a co-reactable blend of (i) 40-98% by weight (w/w) at least one OH, COOH or ethylenically functional (fn) PE having acid or OH number 10-100 mg KOH/g, T9>40° C., where the PE is obtained from reacting a polyacid comprising 70-100% weight of terephthalic acid (TPA) and/or isophthalic acid (IPA) and 0-30% w/w another polyacid; with a polyol comprising 0-85% w/w NPG and 15-100% w/w another polyhydric polyol; (ii) 2-60% w/w at least one glycidyl or isocyanate fn polyphenoxy resin; polyepoxy and/or β-hydroxyalkylamide crosslinker or ethylenically functional oligomer; and (iii) 0.2-5 % w/w of at least one COOH or OH fn acrylic copolymer with a value of 10-100 mg KOH/g; T9>400 C ...

Branched polyester for powder coatings

The present invention relates to a carboxylic acid functional branched polyester, having an acid number of at least 77 mg KOH/g, said carboxylic acid functional branched polyester being the reaction product of a polybasic organic carboxylic acid or its anhydride, preferably trimellitic anhydride, and a branched hydroxyl functional polyester obtained from70 to 100 mole% of terephthalic acid and/or isophtalic acid and, optionally, from 0 to 30 mole% of another polycarboxylic acid, referring to the polyacid constituents, from 10 to 50 mole% of ethylene glycol, from 50 to 87.5 mole% of at least one other aliphatic or cycloaliphatic diol and from 1.5 to 15 mole % of at least one polyol, referring to the polyol constituents, as well as to the use of this polyester to prepare powder coating compositions which present a low gloss, especially of below 35 % (at 60°), when used in combination with standard powder coating polyesters and crosslinkers.

Powder compositions

There is described a thermosetting and/or radiation curable powder with a binder prepared from a polyester (PE) obtained from a polyol with lower amounts of neopentyl glycol (NPG). The powder forms smooth defect free coats and is resistant to contamination from conventional NPG-rich PE. The powder comprises a binder of a co-reactable blend of (i) 40 - 98 % by weight (w/w) at least one OH, COOH or ethylenically functional (fn) PE having acid or OH number 10 - 100 mg KOH/g, T9 > 400C, where the PE is obtained from reacting a polyacid comprising 70 - 100 % weight of terephthalic acid (TPA) and/or isophthalic acid (I PA) and 0 - 30 % w/w another polyacid; with a polyol comprising 0 - 85 % w/w NPG and 15 - 100 % w/w another polyhydric polyol; (ii) 2 - 60 % w/w at least one glycidyl or isocyanate fn polyphenoxy resin; polyepoxy and/or β-hydroxyalkylamide crosslinker or ethylenically functional oligomer; and (iii) 0.2 - 5 % w/w of at least one COOH or OH fn acrylic copolymer with a value of 10 - 100 mg KOH/g; T9 > 400C and a number average molecular weight (Mn) 1000 - 15000 and/or at least one glycidyl or isocyanate fn acrylic copolymer having an fn equivalent weight of from 150 to 1000 g of acrylic copolymer per equivalent of fn group, T9 > 40°C and Mn 1000 to 15000 and/or a non functional acrylic copolymer having Tg > 400C and Mn 1000 to 15000.

Powder compositions

There is described a thermosetting and/or radiation curable powder with a binder prepared from a polyester (PE) obtained from a polyol with lower amounts of neopentyl glycol (NPG). The powder forms smooth defect free coats and is resistant to contamination from conventional NPG-rich PE. The powder comprises a binder of a co-reactable blend of (i) 40 - 98 % by weight (w/w) at least one OH, COOH or ethylenically functional (fn) PE having acid or OH number 10 - 100 mg KOH/g, T 9 > 40 0 C, where the PE is obtained from reacting a polyacid comprising 70 - 100 % weight of terephthalic acid (TPA) and/or isophthalic acid (I PA) and 0 - 30 % w/w another polyacid; with a polyol comprising 0 - 85 % w/w NPG and 15 - 100 % w/w another polyhydric polyol; (ii) 2 - 60 % w/w at least one glycidyl or isocyanate fn polyphenoxy resin; polyepoxy and/or β-hydroxyalkylamide crosslinker or ethylenically functional oligomer; and (iii) 0.2 - 5 % w/w of at least one COOH or OH fn acrylic copolymer with a value of 10 - 100 mg KOH/g; T 9 > 400C and a number average molecular weight (M n ) 1000 - 15000 and/or at least one glycidyl or isocyanate fn acrylic copolymer having an fn equivalent weight of from 150 to 1000 g of acrylic copolymer per equivalent of fn group, T 9 > 40°C and M n 1000 to 15000 and/or a non functional acrylic copolymer having T g > 400C and M n 1000 to 15000.

Powder compositions

Verzweigter polyester für pulverlacke