Methods for the manufacture of an aromatic bisimide and a polyetherimide

1. A method for producing an aromatic bisimide, the method comprising

reacting a dialkali metal salt of a dihydroxy aromatic compound with an N-alkyl nitrophthalimide composition in the presence of 0.5 to 2 mole percent of a phase transfer catalyst based on the total moles of the dialkali metal salt of the dihydroxy aromatic compound under conditions effective to form a product mixture comprising the aromatic bisimide,

wherein the N-alkyl nitrophthalimide composition is prepared by contacting an N—(C 1-13 alkyl)phthalimide with nitric acid and sulfuric acid to provide a nitration product mixture comprising

4-nitro-N—(C 1-13 alkyl)phthalimide, 3-nitro-N—(C 1-13 alkyl)phthalimide, or a combination comprising at least one of the foregoing; and

4-hydroxy-3,5-dinitro-N—(C 1-13 alkyl)phthalimide in an amount of 500-6400 ppm; and

wherein the phase transfer catalyst is a hexa(C 1-12 alkyl)guanidinium salt, a tetra(C 1-12 alkyl)ammonium salt, or a bis-quaternary salt of the formula (R 4 ) 3 Q + (R 3 ) + Q(R 4 ) 3 (Br) 2 , wherein each R 4 is a C 1-4 n-alkyl group and R 3 is a divalent C 1-18 alkylene group,

wherein the aromatic bisimide is obtained in a yield of greater than 75%.

2. The method of claim 1 , wherein the N-alkyl nitrophthalimide composition comprises 4-nitro-N—(C 1-13 alkyl)phthalimide.

3. The method of claim 1 , wherein the N-alkyl nitrophthalimide composition comprises 4-nitro-N—(C 1-13 alkyl)phthalimide and 3-nitro-N—(C 1-13 alkyl)phthalimide, wherein the ratio of 4-nitro-N—(C 1-13 alkyl)phthalimide to 3-nitro-N—(C 1-13 alkyl)phthalimide is 0.001:99.999 to 99.999:0.001.

4. The method of claim 1 , wherein

the dialkali metal salt of a dihydroxy aromatic compound is of the formula

M +− O—Z—O −+ M;

the N-alkyl nitrophthalimide composition comprises a compound of the formula

and

the aromatic bisimide is of the formula

wherein in the foregoing formulas,

M is an alkali metal;

Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1-6 C 1-8 alkyl groups, 1-8 halogen atoms, or a combination comprising at least one of the foregoing; and

R 1 is a monovalent C 1-13 organic group.

5. The method of claim 4 , wherein M is sodium.

6. The method of claim 4 , wherein Z is a divalent group of the formula

wherein Q is —O—, —S—, —C(O)—, —SO 2 —, —SO—, or —C y H 2y — wherein y is an integer from 1-5 or a halogenated derivative thereof.

7. The method of claim 1 wherein the aromatic bisimide comprises 4,4′-bisphenol-A-bis-N-methylphthalimide, 3,4′-bisphenol-A-bis-N-methylphthalimide, 3,3′-bisphenol-A-bis-N-methylphthalimide, or a combination comprising at least one of the foregoing.

8. The method of claim 1 , wherein the product mixture further comprises a nonpolar organic solvent.

9. The method of claim 1 , wherein the product mixture further comprises a dipolar aprotic solvent.

10. The method of claim 1 , wherein the method further comprises extracting the aromatic bisimide from the product mixture to provide an isolated aromatic bisimide, wherein the extracting is with an aqueous alkali solution comprising 0.1-10 wt % by weight alkali metal hydroxide.

11. The method of claim 10 , wherein the isolated aromatic bisimide has a yellowness index of less than 75, as determined according to ASTM D-1925.

12. A method for the manufacture of a polyetherimide, the method comprising

preparing an aromatic bisimide according to the method of claim 1 ;

contacting the aromatic bisimide with a phthalic anhydride in the presence of a catalyst and under conditions effective to provide an aromatic bis(ether phthalic anhydride) of the formula

wherein Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1-6 C 1-8 alkyl groups, 1-8 halogen atoms, or a combination comprising at least one of the foregoing; and

contacting the aromatic bis(ether phthalic anhydride) with an organic diamine of the formula

H 2 N—R—NH 2

wherein R is a C 6-20 aromatic hydrocarbon group or a halogenated derivative thereof, a straight or branched chain C 2-20 alkylene group or a halogenated derivative thereof, a C 3-8 cycloalkylene group or halogenated derivative thereof, or a combination comprising at least one of the foregoing; and

wherein the polyetherimide has a yellowness index of less than 120, as determined according to ASTM D1925 at a thickness of 3.2 millimeters.

13. A method for the manufacture of a polyetherimide, the method comprising,

preparing an aromatic bisimide according to the method of claim 1 ;

hydrolyzing the aromatic bisimide under conditions effective to provide the corresponding tetraacid;

condensing the tetraacid under conditions effective to provide an aromatic bis(ether phthalic anhydride) of the formula

wherein Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1-6 C 1-8 alkyl groups, 1-8 halogen atoms, or a combination comprising at least one of the foregoing; and

contacting the aromatic bis(ether phthalic anhydride) with an organic diamine of the formula

H 2 N—R—NH 2

wherein R is a C 6-20 aromatic hydrocarbon group or a halogenated derivative thereof, a straight or branched chain C 2-20 alkylene group or a halogenated derivative thereof, a C 3-8 cycloalkylene group or halogenated derivative thereof, or a combination comprising at least one of the foregoing; and

wherein the polyetherimide has a yellowness index of less than 120, as determined according to ASTM D1925 at a thickness of 3.2 millimeters.