Coating composition comprising a thermoset resin and a thermoplastic resin
A powder coating composition comprising: a) a thermoset resin comprising an acid functional polyester material, b) a thermoplastic resin and c) a crosslinker material, wherein the coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidylether (BADGE) and bisphenol F diglycidyl ether (BFDGE).
1. A powder coating composition comprising:
a) a thermoset resin comprising an acid functional polyester material,
b) a thermoplastic resin, and
c) a crosslinker material,
wherein the coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).
2. A powder coating composition according to claim 1 , wherein the acid functional polyester material has an acid number (AN) of at least 25 mg KOH/g.
3. A powder coating composition according to claim 1 , wherein the crosslinker material comprises a hydroxyalkylamide material and/or a hydroxy functional alkyl polyurea material and/or a carbodiimide resin.
4. A powder coating composition according to claim 1 , wherein the acid functional polyester material comprises the reaction product of a polyacid and a polyol.
5. A powder coating composition according to claim 4 , wherein the polyacid comprises at least 50 mol % terephthalic acid and/or isophthalic acid based on the total number of moles of polyacid.
6. A powder coating composition according to claim 4 , wherein the acid functional polyester is formed from a polyacid comprising succinic acid, glutaric acid, adipic acid, heptanoic acid, dodecanedioic acid or combinations thereof.
7. A powder coating composition according to claim 4 , wherein the polyol comprises at least 10 mol % of neopentyl glycol based on the total number of moles of polyol.
8. A powder coating composition according to claim 1 , wherein the thermoplastic resin comprises epoxy resin, polyester resin, polyolefin resin, polyurethane resin, polysiloxane resin, acrylic resin, hydrocarbon resin or combinations thereof.
9. A powder coating composition according to claim 8 , wherein the thermoplastic resin comprises polyolefin resin, acrylic resin or a combination thereof.
10. A powder coating composition according to claim 8 , wherein the thermoplastic resin is provided in the form of a powder or in the form of a dispersion in a liquid carrier.
11. A powder coating composition according to claim 10 , wherein the liquid carrier comprises water.
12. A method for producing a powder coating composition comprising:
a) a thermoset resin comprising an acid functional polyester material,
b) a thermoplastic resin and
c) a crosslinker material,
the method comprising the steps of:
i) dispersing components (a), (b) and (c) in a liquid carrier,
ii) drying the dispersion of step (i) to form a powder, and
iii) grinding the powder of step (ii) to a particle size of 5 to 300 micron (μm),
wherein the coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).
13. A metal substrate coated on at least a portion thereof with a thermoset powder coating composition, the powder coating composition comprising:
a) a thermoset resin comprising an acid functional polyester material,
b) a thermoplastic resin and
c) a crosslinker,
wherein the coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).
14. The metal substrate of claim 13 , wherein the substrate is a food and/or beverage packaging.
15. The metal substrate of claim 13 , wherein the substrate is a monobloc aerosol can and/or tube.