Polymer coating system for improved tribological performance

A method of coating a substrate with an aromatic thermosetting copolyester, comprising:

• preparing a powder comprising an aromatic thermosetting copolyester;
• electrostatically spraying the powder onto a surface of a substrate to form a coating on the surface of the substrate;
• and
• heating the surface of the substrate, and
• wherein the aromatic thermosetting copolyester is selected from the group consisting of:
• an aromatic thermosetting copolyester comprising a first oligomer having a carboxylic acid end group and a second oligomer having an acetoxy end group, wherein the ratio of carboxylic acid end groups to acetoxy end groups is greater than 1:1, and wherein the first and/or the second oligomers are formed from at least five monomers, and one of the at least five monomers is perfluorosebacic acid (PFSA) to form a perfluorinated oligomer, and
• an aromatic thermosetting copolyester comprising a first oligomer having a carboxylic acid end group and a second oligomer having an acetoxy end group, wherein the ratio of carboxylic acid end groups to acetoxy end groups is smaller than 1:1, and wherein the first and/or the second oligomers are formed from at least five monomers, and one of the at least five monomers is perfluorosebacic acid (PFSA) to form a perfluorinated oligomer, and
• wherein at least one of the first oligomer and the second oligomer is formed from:
• a first monomer chosen from the group consisting of biphenol diacetate, 1,4-phenylene diacetate;
• 1,3-phenylene diacetate;
• [1,1′-biphenyl]-4,4′-diyl diacetate;
• propane-2,2-diylbis(4,1-phenylene) diacetate;
• sulfonylbis(4,1-phenylene) diacetate (1:1:1:1:1);
• phenyl acetate;
• nonane-1,9-diyl diacetate;
• decane-1,10-diyl diacetate;
• 4,4′-oxydianiline;
• benzene-1,4-diamine;
• and benzene-1,3-diamine;
• a second monomer chosen from the group consisting of 4-acetoxybenzoic acid, 3-acetoxybenzoic acid, and 6-acetoxy-2-napthoic acid;
• a third monomer chosen from the group consisting of trimesic acid (TMA), 1-hydroxypropane-1,2,3-tricarboxylic acid, 3,5-diacetoxybenzoic acid, 5-acetoxyisophthalic acid, [1,1′-biphenyl]-3,3′,5,5′-tetracarboxylic acid, propane-1,2,3-tricarboxylic acid, 2,2-bis(acetoxymethyl)propane-1,3-diyl diacetate, benzene-1,3,5-triyl triacetate, dimethyl 3,3-bis(2-methoxy-2-oxoethyl)pentanedioate, and
• pyromellitic dianhydride;
• and
• a fourth monomer chosen from the group consisting of isophthalic acid (IPA),
• 4,4′-oxydibenzoic acid, [1,1′-biphenyl]-4,4′-dicarboxylic acid, benzoic acid,
• cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, terephthalic acid, azelaic acid acid, sebacic acid, perfluoroazelaic acid, and perfluorosebacic acid.

A method of preparing a coating, comprising:

• preparing a coating precursor comprising an aromatic thermosetting copolyester dissolved in a solvent, and applying the coating precursor onto a surface of a substrate to form a coating on the surface of the substrate, and wherein the aromatic thermosetting copolyester is selected from the group consisting of:
• an aromatic thermosetting copolyester comprising a first oligomer having a carboxylic acid end group and a second oligomer having an acetoxy end group,
• wherein the ratio of carboxylic acid end groups to acetoxy end groups is greater than 1:1, and wherein the first and second oligomers are both formed from at least four monomers and wherein one of the at least four monomers in both the first and second oligomers is biphenol diacetate (BPDA), and
• an aromatic thermosetting copolyester comprising a first oligomer having a carboxylic acid end group and a second oligomer having an acetoxy end group,
• wherein the ratio of carboxylic acid end groups to acetoxy end groups is smaller than 1:1, and wherein the first and second oligomers are both formed from at least four monomers and wherein one of the at least four monomers in both the first and second oligomers is biphenol diacetate (BPDA),
• wherein at least one of the first oligomer and the second oligomer is formed from:
• a second monomer chosen from the group consisting of 4-acetoxybenzoic acid, 3-acetoxybenzoic acid, and 6-acetoxy-2-napthoic acid;
• a third monomer chosen from the group consisting of trimesic acid (TMA), 1-hydroxypropane-1,2,3-tricarboxylic acid, 3,5-diacetoxybenzoic acid, 5-acetoxyisophthalic acid, [1,1′-biphenyl]-3,3′,5,5′-tetracarboxylic acid,
• propane-1,2,3-tricarboxylic acid, 2,2-bis(acetoxymethyl)propane-1,3-diyl diacetate, benzene-1,3,5-triyl triacetate, dimethyl 3,3-bis(2-methoxy-2-oxoethyl)pentanedioate, and pyromellitic dianhydride;
• and
• a fourth monomer chosen from the group consisting of isophthalic acid (IPA),
• 4,4′-oxydibenzoic acid, [1,1′-biphenyl]-4,4′-dicarboxylic acid, benzoic acid,
• cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid,
• terephthalic acid, azelaic acid acid, sebacic acid, perfluoroazelaic acid, and perfluorosebacic acid, and
• wherein either the first or second oligomer is further formed with a fifth monomer selected from perfluorosebacic acid (PFSA) to form a perfluorinated oligomer.

A method of coating a substrate with an aromatic thermosetting copolyester, comprising:

• preparing a powder comprising an aromatic thermosetting copolyester;
• electrostatically spraying the powder onto a surface of a substrate to form a coating on the surface of the substrate;
• and
• heating the surface of the substrate, and
• wherein the aromatic thermosetting copolyester is selected from the group consisting of:
• an aromatic thermosetting copolyester comprising a first oligomer having a carboxylic acid end group and a second oligomer having an acetoxy end group, wherein the ratio of carboxylic acid end groups to acetoxy end groups is greater than 1:1, and wherein the first and second oligomers are both formed from at least four monomers and wherein one of the at least four monomers in the first and/or second oligomers is biphenol diacetate, and
• an aromatic thermosetting copolyester comprising a first oligomer having a carboxylic acid end group and a second oligomer having an acetoxy end group, wherein the ratio of carboxylic acid end groups to acetoxy end groups is smaller than 1:1, and wherein the first and second oligomers are both formed from at least four monomers and wherein one of the at least four monomers in the first and/or second oligomers is biphenol diacetate,
• wherein at least one of the first oligomer and the second oligomer is formed from:
• a first monomer chosen from the group consisting of 1,4-phenylene diacetate;
• 1,3-phenylene diacetate;
• [1,1′-biphenyl]-4,4′-diyl diacetate;
• propane-2,2-diylbis(4,1-phenylene) diacetate;
• sulfonylbis(4,1-phenylene) diacetate (1:1:1:1:1);
• phenyl acetate;
• nonane-1,9-diyl diacetate;
• decane-1,10-diyl diacetate;
• 4,4′-oxydianiline;
• benzene-1,4-diamine;
• and benzene-1,3-diamine;
• a second monomer chosen from the group consisting of 4-acetoxybenzoic acid, 3-acetoxybenzoic acid, and 6-acetoxy-2-napthoic acid;
• a third monomer chosen from the group consisting of trimesic acid (TMA), 1-hydroxypropane-1,2,3-tricarboxylic acid, 3,5-diacetoxybenzoic acid, 5-acetoxyisophthalic acid, [1,1′-biphenyl]-3,3′,5,5′-tetracarboxylic acid, propane-1,2,3-tricarboxylic acid, 2,2-bis(acetoxymethyl)propane-1,3-diyl diacetate, benzene-1,3,5-triyl triacetate, dimethyl 3,3-bis(2-methoxy-2-oxoethyl)pentanedioate, and
• pyromellitic dianhydride;
• and
• a fourth monomer chosen from the group consisting of isophthalic acid (IPA),
• 4,4′-oxydibenzoic acid, [1,1′-biphenyl]-4,4′-dicarboxylic acid, benzoic acid,
• cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, terephthalic acid, azelaic acid acid, sebacic acid, perfluoroazelaic acid, and perfluorosebacic acid, and
• wherein either the first or second oligomer is further formed with a fifth monomer selected from perfluorosebacic acid (PFSA) to form a perfluorinated oligomer.