Low temperature cure carboxyl terminated polyesters

A powder polymeric vehicle comprising:

• from about 85 to about 95 weight percent, based on the weight of the polymeric vehicle, of a carboxylated polyester resin which has an acid value in the range of from about 18 to about 60 and a number average molecular weight in the range of from about 2000 to about 5000, wherein the carboxylated polyester is the reaction product of a hydroxyl terminated polyester and a diacid selected from the group consisting of adipic acid, azelaic acid, chlorendic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, diglycolic acid, dimethyl terephthalic acid, dodecanedioic acid, fumaric acid, glutaric acid, hexahydrophthalic acid, isophthalic acid, maleic acid, succinic acid, tertiary butyl isophthalic acid, nadic acid, napthalene dicarboxylate, phthalic acid, sebacic acid, tetrachlorophthalic acid, corresponding anhydrides, corresponding anhydrides, and mixtures thereof,
• wherein the hydroxyl terminated polyester is the reaction product of an aromatic acid selected from the group consisting of isophthalic acid, terephthalic acid and mixtures thereof, with at least about 25 mole percent of the aromatic acid being isophthalic, from about 3 to about 10 mole percent of a nonaromatic diacid selected from the group consisting of 1,4-cyclohexane dicarboxylic acid, HHPA and mixtures thereof, from about 2 to about 5 mole percent of a polyacid selected from the group consisting of trimellitic anhydride, citric acid and mixtures thereof, a diol selected from the group consisting of neopentyl glycol, cyclohexane dimethanol, 1,6 hexane diol, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butane diol, pentane diol, hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 2-butyl-2-ethyl, 1,3-propanediol, 2,2,4-trimethyl-1,3-pentane diol, hydrogenated bisphenol A, 1,3-pentane diol, 3-hydroxy-2,2-dimethyl propyl 3-hydroxy-2,2-dimethyl-propanate, methyl propane diol, 2-methyl, 2-ethyl, 1,3-propane diol, vinyl cyclohexane diol and mixtures thereof, and from about 3 to about 10 mole percent of a polyol selected from the group consisting of trimethylolpropane, trimethylol ethane, pentaerythoritol, ditrimethylolpropane and mixtures thereof;
• from about 3 to about 15 weight percent based on the weight of the polymeric vehicle, of a polyepoxide which has an average epoxy functionality of not more than about 4 and an average epoxy equivalent weight in the range of from about 80 to about 300;
• and
• an onium catalyst in an amount effective for curing the polymeric vehicle at temperatures not more than about 121° C.,
• the polymeric vehicle having a Tg of from about 45° C. to about 60° C. and a viscosity of less than about 40 poise at 200° C., which polymeric vehicle when cured provides a coating binder having a pencil hardness of at least about HB, a direct impact resistance of at least about 50 inch-lbs. and a reverse impact resistance of at least about 10 inch-lbs. at a binder thickness of about 1.7-2.1 mils.

A process for preparing a formulated powdered coating composition which when applied to a substrate is effective for providing a coating binder having a Tg of about 45° C. to about 60° C., a pencil hardness of at least about HB, a direct impact resistance of at least about 50 in-lbs and a reverse impact resistance of at least about 10 in-lbs at a binder thickness of about 1.7-2.1 mils, the process comprising:

• mixing a carboxylated polyester resin with a polyepoxide compound and an onium catalyst to provide a polymeric vehicle,
• wherein the carboxylated polyester is the reaction product of a hydroxyl terminated polyester and a diacid selected from the group consisting of adipic acid, azelaic acid, chlorendic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, diglycolic acid, dimethyl terephthalic acid, dodecanedioic acid, fumaric acid, glutaric acid, hexahydrophthalic acid, isophthalic acid, maleic acid, succinic acid, tertiary butyl isophthalic acid, nadic acid, napthalene dicarboxylate, phthalic acid, sebacic acid, tetrachlorophthalic acid, corresponding anhydrides and mixtures thereof, corresponding anhydrides and mixtures thereof, and the hydroxyl terminated polyester is the reaction product of an aromatic acid selected from the group consisting of isophthalic acid, terephthalic acid and mixtures thereof, with at least about 25 mole percent of the aromatic acid being isophthalic, and a diol selected from the group consisting of neopentyl glycol, cyclohexane dimethanol, 1,6 hexane diol, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butane diol, pentane diol, hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 2-butyl-2-ethyl, 1,3-propanediol, 2,2,4-trimethyl-1,3-pentane diol, hydrogenated bisphenol A, 1,3-pentane diol, 3-hydroxy-2,2-dimethyl propyl 3-hydroxy-2,2-dimethyl-propanate, methyl propane diol, 2-methyl, 2-ethyl, 1,3-propane diol, vinyl cyclohexane diol and mixtures thereof,
• wherein the polyepoxide has an average epoxy functionality of not more than about 4 and an average epoxy equivalent weight in the range of from about 80 to about 300,
• wherein the onium catalyst is present in an amount effective for curing at temperatures not more than about 121° C.

A powder polymeric vehicle comprising:

• from about 85 to about 95 weight percent, based on the weight of the polymeric vehicle, of a carboxylated polyester resin which has an acid value in the range of from about 18 to about 60 and a number average molecular weight in the range of from about 2000 to about 5000, wherein the carboxylated polyester is the reaction product of a hydroxyl terminated polyester, and a diacid selected from the group consisting of adipic acid, azelaic acid, chlorendic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, diglycolic acid, dimethyl terephthalic acid, dodecanedioic acid, fumaric acid, glutaric acid, hexahydrophthalic acid, isophthalic acid, maleic acid, succinic acid, tertiary butyl isophthalic acid, nadic acid, napthalene dicarboxylate, phthalic acid, sebacic acid, tetrachlorophthalic acid, corresponding anhydrides and mixtures thereof;
• wherein the hydroxyl terminated polyester is a reaction product of an aromatic acid selected from the group consisting of isophthalic acid, terephthalic acid and mixtures thereof, with at least about 25 mole percent of the aromatic acid being isophthalic, and a diol selected from the group consisting of neopentyl glycol, cyclohexane dimethanol, 1,6 hexane diol, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butane diol, pentane diol, hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 2-butyl-2-ethyl, 1,3-propanediol, 2,2,4-trimethyl-1,3-pentane diol, hydrogenated bisphenol A, 1,3-pentane diol, 3-hydroxy-2,2-dimethyl propyl 3-hydroxy-2,2-dimethyl-propanate, methyl propane diol, 2-methyl, 2-ethyl, 1,3-propane diol, vinyl cyclohexane diol and mixtures thereof;
• and
• from about 3 to about 15 weight percent, based on the weight of the polymeric vehicle, of a β-hydroxyalkylamide,
• the polymeric vehicle having a Tg of from about 45° C. to about 60° C. and a viscosity of less than about 40 poise at 200° C., which polymeric vehicle when cured provides a coating binder having a pencil hardness of at least about HB, a direct impact resistance of at least about 50 in-lbs and a reverse impact resistance of at least about 10 in-lbs at a binder thickness of about 1.7-2.1 mils.

A powder polymeric vehicle comprising:

• from about 85 to about 95 weight percent, based on the weight of the polymeric vehicle, of a carboxylated polyester resin which has an acid value in the range of from about 18 to about 60 and a number average molecular weight in the range of from about 2000 to about 5000, wherein the carboxylated polyester is the reaction product of a hydroxyl terminated polyester and a diacid selected from the group consisting of adipic acid, azelaic acid, chlorendic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, diglycolic acid, dimethyl terephthalic acid, dodecanedioic acid, fumaric acid, glutaric acid, hexahydrophthalic acid, isophthalic acid, maleic acid, succinic acid, tertiary butyl isophthalic acid, nadic acid, napthalene dicarboxylate, phthalic acid, sebacic acid, tetrachlorophthalic acid, corresponding anhydrides, corresponding anhydrides, and mixtures thereof,
• wherein the hydroxyl terminated polyester is the reaction product of an aromatic acid selected from the group consisting of isophthalic acid, terephthalic acid and mixtures thereof, with at least about 25 mole percent of the aromatic acid being isophthalic, from about 3 to about 10 mole percent of a nonaromatic diacid selected from the group consisting of 1,4-cyclohexane dicarboxylic acid, HHPA and mixtures thereof, from about 2 to about 5 mole percent of a polyacid selected from the group consisting of trimellitic anhydride, citric acid and mixtures thereof, a diol selected from the group consisting of neopentyl glycol, cyclohexane dimethanol, 1,6 hexane diol, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butane diol, pentane diol, hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 2-butyl-2-ethyl, 1,3-propanediol, 2,2,4-trimethyl-1,3-pentane diol, hydrogenated bisphenol A, 1,3-pentane diol, 3-hydroxy-2,2-dimethyl propyl 3-hydroxy-2,2-dimethyl-propanate, methyl propane diol, 2-methyl, 2-ethyl, 1,3-propane diol, vinyl cyclohexane diol and mixtures thereof, and from about 3 to about 10 mole percent of a polyol selected from the group consisting of trimethylolpropane, trimethylol ethane, pentaerythoritol, ditrimethylolpropane and mixtures thereof;
• and
• from about 3 to about 15 weight percent based on the weight of the polymeric vehicle, based on the weight of the polymeric vehicle, of a β-hydroxyalkylamide,
• the polymeric vehicle having a Tg of from about 45° C. to about 60° C. and a viscosity of less than about 40 poise at 200° C., which polymeric vehicle when cured provides a coating binder having a pencil hardness of at least about HB, a direct impact resistance of at least about 50 inch-lbs. and a reverse impact resistance of at least about 10 inch-lbs. at a binder thickness of about 1.7-2.1 mils.

A process for preparing a formulated powdered coating composition which when applied to a substrate is effective for providing a coating binder having a Tg of about 45° C. to about 60° C., a pencil hardness of at least about HB, a direct impact resistance of at least about 50 in-lbs and a reverse impact resistance of at least about 10 in-lbs at a binder thickness of about 1.7-2.1 mils, the process comprising:

• mixing a carboxylated polyester resin with a β-hydroxyalkylamide to provide a polymeric vehicle,
• wherein the carboxylated polyester is the reaction product of a hydroxyl terminated polyester and a diacid selected from the group consisting of adipic acid, azelaic acid, chlorendic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, diglycolic acid, dimethyl terephthalic acid, dodecanedioic acid, fumaric acid, glutaric acid, hexahydrophthalic acid, isophthalic acid, maleic acid, succinic acid, tertiary butyl isophthalic acid, nadic acid, napthalene dicarboxylate, phthalic acid, sebacic acid, tetrachlorophthalic acid, corresponding anhydrides and mixtures thereof, corresponding anhydrides and mixtures thereof, and the hydroxyl terminated polyester is the reaction product of an aromatic acid selected from the group consisting of isophthalic acid, terephthalic acid and mixtures thereof, with at least about 25 mole percent of the aromatic acid being isophthalic, and a diol selected from the group consisting of neopentyl glycol, cyclohexane dimethanol, 1,6 hexane diol, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butane diol, pentane diol, hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 2-butyl-2-ethyl, 1,3-propanediol, 2,2,4-trimethyl-1,3-pentane diol, hydrogenated bisphenol A, 1,3-pentane diol, 3-hydroxy-2,2-dimethyl propyl 3-hydroxy-2,2-dimethyl-propanate, methyl propane diol, 2-methyl, 2-ethyl, 1,3-propane diol, vinyl cyclohexane diol and mixtures thereof.