Methods for purifying 2-aryl-3,3-bis(hydroxyaryl)phthalimidines
View Patent ↗A method for purifying a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine comprises contacting a crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine with a purification agent, removing a 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound from the crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine, and producing a purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product comprising less than 200 parts per million of the 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound. The purification agent is selected from the group consisting of an acidic material, an organic acid chloride, an organic anhydride, or a combination thereof. The 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound has a formula: wherein each R 1 is independently selected from a group consisting of a hydrocarbyl radical, a nitro radical, and a halogen atom; “a” is an integer from 0 to 4; and Ar 1 and Ar 2 are independently at each occurrence an aromatic radical. The purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidines have low color, and are useful for preparing polymers, such as polycarbonates having a low color. The polycarbonates are useful for producing articles.
1. A method for purifying a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound, the method comprising:
contacting a crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound with a solid acidic material, an organic acid chloride, an organic anhydride, a solution of a mineral acid in a polar organic solvent, a solution of an organosulfonic acid having 2 or more carbon atoms in an organic solvent, acetic acid, or a combination thereof, to remove a 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound having a formula:
wherein each R 1 is independently selected from the group consisting of a hydrocarbyl radical, a nitro radical, and a halogen atom; “a” is an integer from 0 to 4; and Ar 1 and Ar 2 are independently at each occurrence an aromatic radical; and
producing a purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product comprising less than 200 parts per million of the 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound.
2. The method of claim 1 , further comprising treating the purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product with a polar organic solvent and reducing an APHA value of the product to less than 20 as measured using test method ASTM D1209.
3. The method of claim 1 , wherein the solid acidic material comprises an acidic metal oxide, an acidic organic polymer, or a combination of the acidic metal oxide and the acidic organic polymer.
4. The method of claim 3 , wherein the acidic metal oxide comprises an acidic silica, an acidic alumina, an acid-washed carbon, or a sulfated zirconia.
5. The method of claim 3 , wherein the acidic organic polymer is selected from the group consisting of a poly(vinylsulfonic acid), a poly(vinylphosphonic acid), and an acidic ion exchange resin.
6. The method of claim 5 , wherein the acidic ion exchange resin is a sulfonated polystyrene-divinylbenzene copolymer crosslinked with up to 20 weight percent of divinylbenzene relative to an overall weight of the acidic ion exchange resin.
7. The method of claim 3 , wherein the organosulfonic acid having 2 or more carbon atoms is selected from the group consisting of ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, octanesulfonic acid, dodecylbenzenesulfonic acid, and a combination of the foregoing organosulfonic acids.
8. The method of claim 1 , wherein the acid in a polar organic solvent is an alcoholic mineral acid, wherein the mineral acid is selected from the group consisting of phosphoric acid, hydrochloric acid, and a combination of the foregoing mineral acids.
9. The method of claim 1 , wherein the organic anhydride is phthalic anhydride.
10. The method of claim 1 , further comprising recycling the purification agent, wherein the purification agent is an acidic ion exchange resin.
11. The method of claim 1 , further comprising contacting the purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product with a metal oxide for a period of time effective to reduce one more metal impurity concentrations to less than 500 parts per billion of each metal and produce an ultra-pure 2-aryl-3,3-bis(hydroxyaryl)phthalimidine.
12. The method of claim 11 , wherein the metal oxide comprises a basic metal oxide, a neutral metal oxide, or an acidic metal oxide.
13. The method of claim 11 , wherein the metal oxide is selected from the group consisting of an acidic silica and an acidic alumina.
14. The method of claim 11 , further comprising washing the metal oxide with an aqueous mineral acid prior to contacting the purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product with the metal oxide.
15. The method of claim 14 , wherein the aqueous mineral acid is hydrochloric acid.
16. The method of claim 11 , wherein the one or more metal impurities is selected from the group consisting of iron, calcium, zinc, aluminum, and sodium.
17. The method of claim 1 , wherein the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine is 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine.
18. A polymer comprising structural units derived from the purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product of claim 1 .
19. A polycarbonate comprising structural units derived from the purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product of claim 2 and having an APHA value of less than 20 as measured using test method ASTM D1209, and
wherein the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine has the structure of formula (I):
wherein R 1 is independently selected from a group consisting of a hydrocarbyl radical, a nitro radical, and a halogen atom; “a” is an integer from 0-4; and Ar 1 and Ar 2 are independently at each occurrence an aromatic radical.
20. A method for preparing an ultra-pure 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product, the method comprising:
contacting a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine with a solid acidic material, an organic acid chloride, an organic anhydride, a solution of an acid in a polar organic solvent, a solution of an organosulfonic acid having 2 or more carbon atoms in an organic solvent, acetic acid, or a combination thereof, to produce a purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product comprising one or more metal impurities at a concentration of greater than 500 parts per billion of each metal, and less than 200 parts per million of a 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine having a formula:
wherein each R 1 is independently selected from the group consisting of a hydrocarbyl radical, a nitro radical, and a halogen atom; “a” is an integer from 0 to 4; and Ar 1 and Ar 2 are independently at each occurrence an aromatic radical; and
contacting the purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product with a metal oxide adsorbent to produce the ultra-pure 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product wherein at least one of the metal impurities has been reduced to less than 500 parts per billion of the metal.
21. The method of claim 20 , further comprising treating the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine with a polar organic solvent prior to contacting with the metal oxide adsorbent, to produce a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine having an APHA value of less than 10 as measured using test method ASTM D1209.
22. A method for preparing a polycarbonate polymer comprising structural units derived from a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound, the method comprising:
reacting a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound with a carbonate precursor to produce the polycarbonate polymer, wherein the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound has less than 200 parts per million of a 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine having a formula:
wherein each R 1 is independently selected from a group consisting of a hydrocarbyl radical, a nitro radical, and a halogen atom; “a” is an integer from 0 to 4; and Ar 1 and Ar 2 are independently at each occurrence an aromatic radical.
23. The method of claim 22 , wherein the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound has less than 500 parts per billion of at least three of iron, calcium, sodium, aluminum, and zinc.
24. The method of claim 22 , wherein the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound has an APHA value of less than 20 as measured using test method ASTM D1209.
25. The method of claim 22 , wherein the polycarbonate has a yellowness index of less than 10 as measured using test method ASTM E313-00.
26. A polycarbonate comprising structural units derived from an ultra-pure 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine product, wherein the ultra-pure 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine product comprises less than 200 parts per million of 2-phenyl-3-(4-aminophenyl)-3-(4-hydroxyphenyl)phthalimidine; and less than 500 parts per billion of at least three of iron, calcium, sodium, aluminum, and zinc individually.
27. The method of claim 16 , wherein the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound has less than 500 parts per billion of each of iron, calcium, sodium, aluminum, and zinc individually.
28. The method of claim 20 , wherein the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound has less than 500 parts per billion of each of iron, calcium, sodium, aluminum, and zinc individually.
29. The method of claim 22 , wherein the 2-aryl-3,3-bis(hydroxyaryl)phthalimidine compound has less than 500 parts per billion of each of iron, calcium, sodium, aluminum, and zinc individually.
30. The polycarbonate of claim 26 , wherein the 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine compound has less than 500 parts per billion of each of iron, calcium, sodium, aluminum, and zinc individually.