Polyetherimides with improved melt stability

1. A method for the manufacture of a polyetherimide composition having improved melt stability, the method consisting of catalyzing imidization of a 3-substituted phthalic anhydride of the formula

with a sulfone diamine selected from 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone, and combinations thereof with a hexa(C 1-6 )alkylguanidinium salt catalyst, a α,ω-bis(penta(C 1-6 )alkylguanidinium)(C 1-6 )alkane salt catalyst or a combination thereof in the presence of a solvent, to provide a bis(phthalimide) composition comprising a residue of the catalyst and a 3,3′-bis(phthalimide) of the formula

wherein the 3-substituted phthalic anhydride and the sulfone diamine convert to the 3,3′-bis(phthalimide) to at least 99% completion, and

catalyzing polymerization of the 3,3′-bis(phthalimide) and an alkali metal salt of a dihydroxy aromatic compound of the formula

MO—Z—OM

in the presence of the catalyst that catalyzes the imidization of the 3-substituted phthalic anhydride and the sulfone diamine to form the polyetherimide composition consisting of

a residue of the catalyst and

a polyetherimide of the formula

wherein in the foregoing formulae

X is selected from fluoro, chloro, bromo, iodo, and combinations thereof;

R is selected from 3,3′-diphenylene sulfone, 3,4′-diphenylene sulfone, 4,4′-diphenylene sulfone, and combinations thereof;

M is an alkali metal;

Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C 1-8 alkyl groups, 1 to 8 halogen atoms, or combinations thereof; and

n is an integer greater than 1;

wherein the polyetherimide has a Tg that is more than 247° C., no detectable amount of sodium aryl phosphinate salt, and,

wherein the polyetherimide, in molten form, has a viscosity that is the same viscosity as the initial viscosity or less than the initial viscosity after the polyetherimide is exposed to a temperature that is at least 400° C. for at least 5 minutes, the initial viscosity being the viscosity the polyetherimide has after the polyetherimide has been exposed to at least 400° C. for six minutes.

2. The method of claim 1 , wherein the polyetherimide is exposed to a temperature of 770° F. (410° C.).

3. The method of claim 1 , wherein the 3-substituted phthalic anhydride and the sulfone diamine converts to the 3,3′-bis(phthalimide) in a conversion of at least 99.5%.

4. The method of claim 1 , wherein the polyetherimide has a glass transition temperature, Tg, that is at least 260° C.

5. The method of claim 4 , wherein X is chloro, and Z is 2,2-(4-phenylene) isopropylidene.

6. The method of claim 1 , wherein the polyetherimide retains a melt stability that is at least 95% when the polyetherimide is exposed to a temperature of 770° F. (410° C.) for 9 minutes.

7. The method of claim 1 , wherein the catalyst is present in an amount ranging from 0.05 to 1 mole % based on the moles of the sulfone diamine during the imidization, and a second catalyst is added before the polymerization, wherein the second catalyst is the same catalyst used for the imidization.

8. The method of claim 1 , wherein the catalyst is hexaethylguanidinium chloride.

9. The method of claim 1 , wherein the 3,3′-bis(phthalimide) composition and the polyetherimide composition are manufactured in the same vessel.

10. The method of claim 1 , wherein X is chloro, fluoro, or bromo, and

Z is a divalent group of formula

wherein

R a and R b are each a halogen atom or a monovalent hydrocarbon group and can be the same or different;

X a is a single bond, —O—, —S—, —S(O)—, —S(O) 2 —, —C(O)—, or a C 1-18 organic group;

p and q are each independently integers of 0 to 4; and

c is 0 or 1.

11. The method of claim 1 , wherein less than 1000 ppm of the residue of the catalyst, based on the weight of the polyetherimide is present in the polyetherimide composition.

12. An article comprising the polyetherimide composition manufactured by the method of claim 1 .

13. The article of claim 12 , selected from a sheet, film, multilayer sheet, multilayer film, molded part, extruded shape, coated part, molded shape, pellet, powder, foam, fiber, fibrid, flaked fiber, and combinations thereof.

14. The article of claim 12 , wherein the article is a molded part.

15. The article of claim 14 , wherein the molded part is an injection molded part.

16. The article of claim 12 , wherein the article is a sheet or film and further comprises a conductive metal layer disposed on a side thereof.

17. The article of claim 12 , wherein the article is an optical lens.

18. The article of claim 12 , wherein the article is an optical fiber connector, an electrical connector, an LED reflector, a printed circuit board substrate, or a reflector for automotive headlamp.

19. A polyetherimide composition consisting of

(i) a polyetherimide of the formula

and

(ii) a residue of a guanidinium catalyst and optionally, a residue of a catalyst selected from quaternary ammonium salts, quaternary phosphonium salts, pyridinium salts, imidazolium salts, and combinations thereof, wherein the guanidinium catalyst comprises hexa(C 1-6 )alkylguanidinium salt catalyst, a α,ω-bis(penta(C 1-6 )alkylguanidinium)(C 1-6 )alkane salt catalyst or a combination thereof, wherein the guanidinium catalyst residue is present in an amount less than 1000 ppm, based on the weight of the polyetherimide,

the polyetherimide being a catalyzed polymerization reaction product of (1) a 3,3′-bis(phthalimide) composition comprising a catalyzed imidization product of a 3-substituted phthalic anhydride and a sulfone diamine selected from 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone, and combinations thereof, and (2) an alkali metal salt of a dihydroxy aromatic compound, the imidization product being catalyzed by the guanidinium catalyst;

wherein

the substituted 3-phthalic anhydride has a formula

the sulfone diamine has a formula

H 2 N—R—NH 2 ,

the 3,3′-bis(phthalimide) has a formula

and

the alkali metal salt of the dihydroxy aromatic compound has a formula

MO—Z—OM,

wherein in the foregoing formulae,

X is selected from fluoro, chloro, bromo, iodo, and combinations thereof;

R is selected from 3,3′-diphenylene sulfone, 3,4′-diphenylene sulfone, 4,4′-diphenylene sulfone, and combinations thereof;

M is an alkali metal;

Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C 1-8 alkyl groups, 1 to 8 halogen atoms, or combinations thereof; and

n is an integer greater than 1;

wherein the polyetherimide has a Tg that is more than 247° C., no detectable amount of sodium aryl phosphinate salt, and,

wherein the polyetherimide, in molten form, has a viscosity that is the same viscosity as the initial viscosity or less than the initial viscosity after the polyetherimide is exposed to a temperature that is at least 400° C. for at least 5 minutes, the initial viscosity being the viscosity the polyetherimide has after the polyetherimide has been exposed to at least 400° C. for six minutes.

20. The polyetherimide composition of claim 19 , wherein the polymerization is catalyzed by the same catalyst that catalyzes the imidization.

21. The polyetherimide composition of claim 19 , wherein the imidization catalyst is hexaethylguanidinium chloride.

22. The polyetherimide composition of claim 19 , wherein

X is chloro, fluoro, or bromo, and

Z is a divalent group of formula

wherein

R a and R b are each a halogen atom or a monovalent hydrocarbon group and can be the same or different;

X a is a single bond, —O—, —S—, —S(O)—, —S(O) 2 —, —C(O)—, or a C 1-18 organic group;

p and q are each independently integers of 0 to 4; and

c is 0 or 1.

23. The polyetherimide composition of claim 22 , wherein

X is chloro, and

Z is 2,2-(4-phenylene)isopropylidene.

24. An article comprising the polyetherimide composition of claim 19 .

25. The article of claim 24 , selected from a sheet, film, multilayer sheet, multilayer film, molded part, extruded shape, molded shape, coated part, pellet, powder, foam, fiber, fibrid, flaked fiber, and combinations thereof.

26. The article of claim 25 , wherein the article is a sheet or film and further comprises a conductive metal layer disposed on a side thereof.

27. The article of claim 24 , wherein the article is selected from an extruded sheet, extruded film, extruded fiber, and extruded stockshape.

28. The article of claim 24 , wherein the article is a molded part.

29. The article of claim 28 , wherein the molded part is an injection molded part.

30. The article of claim 24 , wherein the article is an optical lens.

31. The article of claim 24 , wherein the article is an optical fiber connector, an electrical connector, an LED reflector, a printed circuit board substrate, or a reflector for automotive headlamp.

32. A method of forming an article, comprising shaping, extruding, blow molding, or injection molding the polyetherimide composition of claim 19 to form the article.