Polyester process
View Patent ↗The present disclosure provides processes for the preparation of unsaturated polyesters. In embodiments, a process of the present disclosure includes reacting an organic diol with a cyclic alkylene carbonate in the presence of a first catalyst to thereby form a polyalkoxy diol, optionally adding thereto a further amount of cyclic alkylene carbonate in the presence of a second catalyst, and subsequently polycondensing the resulting mixture with a dicarboxylic acid in combination with an anhydride.
1. A process comprising:
reacting an organic diol selected from the group consisting of 1,2-propanediol, 1,3-propanediol, 1,3-butane diol pentylene glycol, hexylene glycol, diphenol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2-bis-(4-hydroxy phenyl) propane, 2,2-bis-(3-hydroxy phenyl)propane, 2,2-bis-(2-hydroxy phenyl)propane, 2,2-bis-(3-hydroxy phenyl)propane, 2,2-bis(5-hydroxy phenyl)propane, Bisphenol A, ethoxylated Bisphenol-A, bis-(4-hydroxy phenyl)methane, 1,1-bis-(4-hydroxy phenyl)ethane, cis-1,4-dihydroxy-cyclohexane, trans-1,4-dihydroxy cyclohexane, cis-1,2-dihydroxy-cyclohexane, trans-1,2-dihydroxy-cyclohexane, trans-1,3-dihydroxy-cyclohexane, cis-1,3-dihydroxy-cyclohexane, and combinations thereof, with a cyclic alkylene carbonate selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, and combinations thereof, in the presence of a first catalyst of an alkali carbonate to form a polyalkoxy diol;
contacting the polyalkoxy diol with an additional amount of cyclic alkylene carbonate in the presence of a second catalyst of an alkali alkoxide to form a mixture;
polycondensing the resulting mixture with a dicarboxylic acid and an anhydride selected from the group consisting of maleic anhydride, trimellitic anhydride, n-dodecenylsuccinic anhydride, 2-dodecenylsuccinic anhydride, 2-undecenylsuccinic anhydride, and combinations thereof, the diacid and the anhydride utilized in a combined amount of from about 0.90 mole equivalents to about 1.1 mole equivalents; and
recovering an unsaturated polyester.
2. The process according to claim 1 , wherein the diol is utilized in an amount of from about 0.90 mole equivalents to about 1.1 mole equivalents, based on about 1 mole equivalent of dicarboxylic acid utilized, and wherein the cyclic alkylene carbonate is utilized in an amount of from about 1.90 mole equivalents to about 2.45 ma equivalents, based an about 1 mole equivalent of organic diol utilized.
3. The process according to claim 1 , wherein the first catalyst comprises an alkali carbonate selected from the group consisting of potassium carbonate, sodium carbonate, rubidium carbonate, cesium carbonate, beryllium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, manganese carbonate, barium carbonate, and combinations thereof, utilized in an amount of from about 0.001 mole equivalents to about 0.1 mole equivalents, based on about 1 mole equivalent of organic diol utilized, and wherein the second catalyst comprises an alkali alkoxide selected from the group consisting of lithium methoxide, lithium ethoxide, lithium propoxide, lithium butoxide, isopropoxide, lithium isobutoxide, lithium t-butoxide, potassium methoxide potassium ethoxide, potassium propoxide, potassium butoxide, potassium isopropoxide, potassium isobutoxide, potassium t-butoxide, sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, sodium isopropoxide, sodium isobutoxide, sodium t-butoxide, and combinations thereof, utilized in an amount of from about 0.001 mole equivalents to about 0.1 mole equivalents, based on about 1 mole equivalent of organic diol utilized.
4. The process according to claim 1 , wherein the dicarboxylic acid is selected from the group consisting of fumaric acid, malonic acid, itaconic acid, 2-methylitaconic acid, maleic acid, trimelitic acid, adipic acid, succinic acid, suberic acid, 2-ethyl succinic acid, glutaric acid, dodecylsuccinic acid, 2-methyladipic acid, pimelic acid; azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,2-cyclohexanedioic acid, 1,3-cyclohexanedioic acid, 1,4-cyclohexanedioic acid; dialkyl esters wherein alkyl contains from about 2 to about 18 carbon atoms, and are esters of malonate, succinate, fumarate, itaconate, terephthalate, isophthalate, phthalate, cyclohexanedioate, and combinations thereof.
5. The process according to claim 1 , wherein said reacting is accomplished by heating at a temperature of from about 160° C. to about 215° C., and wherein said polycondensing is accomplished by heating at a temperature of from about 185° C. to about 225° C. for a duration of from about 1 hour to about 5 hours, followed by reducing pressure of the mixture from about 760 Torr to about 1 Torr over a period of from about 1 hour to about 6 hours.
6. The process according to claim 1 , wherein the unsaturated polyester resin is selected from the group consisting of poly(propoxylated bisphenol co-fumarate), poly(ethoxylated bisphenol co-fumarate), poly(butoxylated bisphenol co-fumarate), poly(co-propoxylated bisphenol co ethoxylated bisphenol co-fumarate), poly(1,2-propylene fumarate), poly(propoxylated co-maleate), poly(ethoxylated bisphenol co-maleate), poly(butyloxylated bisphenol co-maleate), poly(co-propoxylated bisphenol co ethoxylated bisphenol co-maleate), poly(1,2-propylene maleate, poly(propoxylated bisphenol co-itaconate), poly(ethoxylated bisphenol co-itaconate), poly(butyloxylated bisphenol co-itaconate), poly(co-propoxylated bisphenol co ethoxylated bisphenol co-itaconate), poly(1,2-propylene itaconate), and combinations thereof.