Chloro-substituted polyetherimides having improved relative thermal index

1. A polyetherimide comprising a structural unit of Formula (I):

wherein R and R′ can be a linear or cyclic C 2 to C 20 alkyl group or a substituted or unsubstituted C 6 to C 30 aryl group, n has a value of 1 to 40,

wherein the polyetherimide has an OH content that is greater than 0 and less than or equal to 100 parts per million by weight (ppm);

wherein the polyetherimide has a Relative Thermal Index that is greater than or equal to 170° C. measured using the protocol UL746B; and

wherein the polyetherimide has a chlorine content that is greater than 0 ppm.

2. The polymer of claim 1 , wherein chlorine content is present in an amount greater than 0 to 4,000 ppm.

3. The polymer of claim 1 , wherein the polyetherimide has a flame retardant rating of V0 at 1.5 mm.

4. The polymer of claim 3 , wherein the polyetherimide has a flame retardant rating of V0 at 0.8 mm.

5. A composition comprising the polyetherimide of claim 1 and an additional polymer.

6. The composition of claim 5 , wherein the additional polymer is selected from the group consisting of polyesters, polycarbonates, polyolefins, polysulfones, polyphenylene sulfides, polyetheretherketones, polyethersulfones, polyamides, polyamideimides, and combinations thereof.

7. The polyetherimide of claim 1 having the structural unit of Formula (III):

wherein n is an integer having a value of 1 to 40.

8. A composition comprising the polyetherimide of claim 7 and an additional polymer.

9. The composition of claim 8 , wherein the additional polymer is selected from the group consisting of polyesters, polycarbonates, polyolefins, polysulfones, polyphenylene sulfides, polyetheretherketones, polyethersulfones, polyamides, polyamideimides, and combinations thereof.

10. A method for preparing the polyetherimide of claim 1 , which comprises

contacting, in o-dichlorobenzene or anisole as diluent, substantially equimolar amounts of

a disodium salt of a dihydroxy compound of formula HO—R′—OH, and

a slurry of a bisimide, in the presence of a catalytically active amount of a phase transfer catalyst, thereby polymerizing the bisimide and the disodium salt;

wherein the bisimide and the disodium salt are polymerized in the presence of a base selected from alkali metal carbonates, alkyl hydrides, alkali metal hydroxides, alkali metal phosphates, alkali metal bicarbonates, alkali metal acetates, and combinations thereof;

wherein said slurry of bisimide comprises the reaction product of a mixture comprising a diamine of formula H 2 N—R—NH 2 ; chlorophthalic anhydride; and o-dichlorobenzene or anisole; and an optional imidization catalyst, said mixture having a solids content of greater than or equal to about 5% by weight;

wherein the base is added in an amount that is sufficient to produce the polyetherimide of claim 1 .

11. The method of claim 10 , wherein the bisimide is made by reacting chlorophthalic anhydride and excess amount of diamine or a stoichiometric amount of diamine.

12. The method of claim 10 , wherein the method further comprises adding a capping agent and capping amine groups.

13. The method of claim 12 , wherein the capping agent is selected from the group consisting of chlorophthalic anhydrides, phthalic anhydrides, substituted phthalic anhydrides, alkyl anhydrides, cyclic alkyl anhydrides, substituted aryl anhydrides, acyl alkyl halides, acyl aryl halides, aldehydes, ketones, esters, isocyanates, chloroformates, sulfonyl chlorides, and combinations thereof.

14. The method of claim 10 , wherein the disodium salt has excess sodium hydroxide and is caustic rich.

15. The method of claim 10 , wherein the base is K 3 PO 4 .

16. The method of claim 15 , wherein the K 3 PO 4 is added in the form of solid or an aqueous solution.

17. The method of claim 16 , wherein the K 3 PO 4 is added in an aqueous solution and the K 3 PO 4 is dried with bisphenol A disodium salt or 1,3-bis[N-(4-chlorophthalimido)]benzene prior to addition to the slurry.

18. The method of claim 16 , wherein the K 3 PO 4 is added as a solid.

19. The method of claim 18 , wherein the K 3 PO 4 added has a particle size of greater than 0 to 400 microns.

20. The method of claim 19 , wherein the K 3 PO 4 added has a particle size ranging greater than 0 to less than 75 microns.

21. The method of claim 13 , wherein the alkali metal hydroxide is sodium hydroxide.

22. The method of claim 10 , wherein the disodium salt is a bisphenol A disodium salt, the bisimide slurry is a slurry of 1,3-bis[N-(4-chlorophthalimido)]benzene, and the phase transfer catalyst is hexaalkylguanidinium chloride wherein said slurry of 1,3-bis[N-(4-chlorophthalimido)]benzene comprises the reaction product of a mixture comprising m-phenylenediamine; 4-chlorophthalic anhydride; and o-dichlorobenzene or anisole; and an optional imidization catalyst, said mixture having a solids content of greater than or equal to about 5% by weight.

23. A polymer comprising a polyetherimide having the structure of Formula (III):

wherein the polyetherimide has an OH content that is greater than 0 and equal or less than 100 ppm;

wherein the polyetherimide has a Relative Thermal Index that is greater than or equal to 170° C. measured using the protocol UL746B; and

wherein the polyetherimide has a chlorine content that is greater than 0 and less than or equal to 4000 ppm;

wherein the polyetherimide is made by a method comprising

contacting, in o-dichlorobenzene or anisole as diluent, substantially equimolar amounts of bisphenol A disodium salt and a slurry of 1,3-bis[N-(4-chlorophthalimido)]benzene, in the presence of a catalytically active amount of a hexaalkylguanidinium chloride as a phase transfer catalyst, thereby polymerizing the 1,3-bis[N-(4-chlorophthalimido)]benzene and the bisphenol A disodium salt;

wherein the 1,3-bis[N-(4-chlorophthalimido)]benzene and the bisphenol A disodium salt are polymerized in the presence of a base selected from the group consisting of alkali metal carbonates, alkyl hydrides, alkali metal phosphates, alkali metal bicarbonates, alkali metal hydroxides, alkali metal acetates, and combinations thereof;

wherein said slurry of 1,3-bis[N-(4-chlorophthalimido)]benzene comprises the reaction product of a mixture comprising m-phenylenediamine; 4-chlorophthalic anhydride; and o-dichlorobenzene or anisole; and an optional imidization catalyst, said mixture having a solids content of greater than or equal to about 5% by weight

wherein the base is added in an amount that is sufficient to produce the polyetherimide of claim 1 .

24. An article comprising the polymer of claim 1 .

25. An article comprising the polymer of claim 7 .

26. An article comprising the composition of claim 5 .

27. An article comprising the composition of claim 8 .

28. A composition comprising the polyetherimide of claim 1 and a polyimide other than the polyetherimide of claim 1 .

29. A composition comprising the polyetherimide of claim 7 and a polyimide other than the polyetherimide of claim 7 .