Process for preparing a biphenol dianhydride composition, process for purifying a biphenol dianhydride, and poly(etherimide) derived from a biphenol dianhydride

Abstract

A method for preparing a biphenol dianhydride composition, comprising heating a first solution, the first solution comprising a biphenol tetracarboxylic acid of formula (I), wherein Ra, Rb, p and q are as defined herein; at least one of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, iron ions, phosphate ions, sulfate ions, chloride ions, nitrate ions and nitrite ions; and a non-halogenated solvent. The first solution is heated under conditions effective to provide a second solution, the second solution comprising: the corresponding biphenol dianhydride; at least one of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, iron ions, phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions; and a non-halogenated solvent.

Description

[0001] Citation of Related Applications

[0002] This application claims the benefit of European Patent Application No. 19154911.2, filed on January 31, 2019, the entire content of which is incorporated herein by reference. Background Art

[0003] Poly(imides), and in particular poly(ether imides) (PEI), are high-performance polymers having a glass transition temperature (Tg) greater than 180 °C. These polymers also have high strength, heat resistance, modulus, and a broad chemical resistance. Poly(ether imides) are widely used in a variety of applications such as automotive and electrical / electronic applications because these compositions provide good mechanical and thermal properties.

[0004] Poly(ether imides) can be prepared, for example, by polycondensation of dianhydrides with diamines. To obtain good reaction kinetics, achieve high molecular weight, and provide a stable and processable polymer product, high-purity monomer components are required. In addition, some applications may require the polymer to have good optical transparency as well as good thermal and mechanical properties. The haze level exhibited by articles may be related to the method of preparing the polymer. In fact, it may be difficult to produce the desired dianhydrides that are substantially free of alkali metals and their salts.

[0005] Accordingly, there is a need in the art for dianhydride monomers that are substantially free of residual phase transfer agents, sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, iron ions, phosphate ions, nitrate ions, nitrite ions, sulfate ions, and chloride ions. A further advantage is to provide poly(ether imides) that have low levels of such contaminants and exhibit low haze, high optical clarity, good reaction kinetics during polymerization, high molecular weight, and are stable and processable polymers. Summary of the Invention

[0006] A method for preparing a biphenol dianhydride composition, the method comprising: heating a first solution under conditions effective to provide a second solution, the first solution comprising: a biphenol tetracarboxylic acid of the formula

[0007]

[0008] wherein R a and R b are each independently a halogen or a monovalent C 1-6an alkyl group, and p and q are each independently an integer from 0 to 4, preferably, wherein p and q are each 0; at least one of sodium ion, potassium ion, calcium ion, zinc ion, aluminum ion, titanium ion, phosphorus ion, iron ion, phosphate ion, sulfate ion, chloride ion, nitrate ion, nitrite ion, and sulfite ion; and a non-halogenated solvent, the non-halogenated solvent including ethyl benzoate, diphenyl ether, phenetole, triglyme, benzonitrile, sulfolane, m-cresol, o-cresol, p-cresol, 1-nitrotoluene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethylacetamide, or a combination thereof; the second solution includes: the corresponding biphenol dianhydride; and at least one of sodium ion, potassium ion, calcium ion, zinc ion, aluminum ion, titanium ion, phosphorus ion, iron ion, phosphate ion, sulfate ion, chloride ion, nitrate ion, nitrite ion, and sulfite ion; and a solvent.

[0009] Also described is a biphenol dianhydride prepared by the above method.

[0010] Also described is a poly(etherimide) derived from a biphenol dianhydride and an organic diamine.

[0011] A method for preparing a poly(etherimide) includes: contacting a biphenol dianhydride with an organic diamine in the presence of an aromatic non-halogenated solvent under conditions effective to provide the poly(etherimide).

[0012] An article includes a poly(etherimide).

[0013] The above and other features are illustrated by the following specific embodiments. Specific Embodiments

[0014] The inventors have unexpectedly found that biphenol dianhydrides with low levels of residual contaminants can be prepared, particularly by using non-halogenated solvents. The inventors have also discovered a method for preparing biphenol dianhydrides from the corresponding tetra-acid precursors using non-halogenated solvents, and advantageously, the biphenol dianhydrides can be directly used for polymerization with diamines without first separating the dianhydrides. Thus, the disclosed biphenol dianhydrides can also be advantageously used to prepare poly(etherimides) with low levels of residual contaminants, thereby providing the desired properties for the polymers, particularly good optical transparency and low haze. It has been found that poly(etherimides) having a rigid backbone based on biphenyl moieties achieve high molecular weights when prepared using non-halogenated solvents.

[0015] Accordingly, one aspect of the present disclosure is a method for preparing a biphenol dianhydride composition. The method includes heating a first solution that contains: biphenol tetracarboxylic acid; at least one of sodium ion, potassium ion, calcium ion, zinc ion, aluminum ion, iron ion, phosphate ion, sulfate ion, chloride ion, nitrate ion, and nitrite ion; and a non-halogenated solvent.

[0016] The biphenol tetracarboxylic acid has the following formula

[0017]

[0018] wherein, R a and R b are each independently a halogen or a monovalent C 1-6 alkyl group, and p and q are each

[0019] independently an integer from 0 to 4. Preferably, wherein p and q are each 0. In some embodiments, p, q, or both can be 1 to 4, preferably 1 to 2, more preferably 1. In some embodiments, R a and R b can each independently be a C 1-3 alkyl group, such as a methyl group. The double bond of the biphenyl group can be in the 3,3'-position, 3,4'-position, or 4,4'-position. Preferably, the double bond of the biphenyl group can be in the 3,3'-position. The biphenol tetracarboxylic acid can preferably contain less than 0.5 wt% of biphenyl as a contaminant.

[0020] The non-halogenated solvent is preferably an aromatic non-halogenated solvent. The non-halogenated solvent can include ethyl benzoate, diphenyl ether, phenetole, triglyme, benzonitrile, sulfolane, m-cresol, o-cresol, p-cresol, 1-nitrotoluene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide, or a combination thereof. In some embodiments, solvents other than the non-halogenated solvent are excluded from the method. For example, the method can be carried out in the absence of any halogenated solvent. For example, in some embodiments, the method can exclude halogenated solvents such as o-dichlorobenzene.

[0021] The first solution is heated under conditions effective to provide a second solution containing the corresponding biphenol dianhydride. The biphenol dianhydride can be of the following formula

[0022]

[0023] wherein, R a , R b, p and q are defined as above. The second solution may further comprise: at least one of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, iron ions, phosphate ions, sulfate ions, chloride ions, nitrate ions, nitrite ions, and sulfite ions; and a non-halogenated solvent. In some embodiments, the ionic species may include one or more inorganic salts, for example, NaHSO3, Na2SO4, KHSO3, K2SO4, NaNO3, NaNO2, KNO3, KNO2, NaCl, KCl, CaSO4, and Ca(NO3)2.

[0024] Conditions for effectively providing the second solution may include, for example: a temperature of 100 °C to 200 °C, preferably 120 °C to 180 °C, more preferably 150 °C to 180 °C; and a time of 5 minutes to 10 hours, preferably 1 hour to 10 hours, more preferably 3 hours to 5 hours. In one aspect, the time for providing the second solution may be less than 5 hours, or less than 4 hours, or less than 3 hours, or 0.5 hours to less than 5 hours, or 0.5 hours to 4 hours, or 0.5 hours to 3 hours, or 0.5 hours to 2 hours, or 0.5 hours to 1 hour. The heating may be carried out under pressure, under reduced pressure, or at atmospheric pressure. In some embodiments, the method is preferably carried out in the absence of a dehydrating agent (such as acetic acid, acetic anhydride, etc. or a combination thereof). In some embodiments, a phase transfer catalyst is excluded from the method.

[0025] In an advantageous feature, the method provided herein may exclude the addition of an acid. For example, the method does not require the addition of an acid such as, but not limited to, hydrochloric acid, acetic acid, formic acid, etc. or a combination thereof.

[0026] In some embodiments, the method may further optionally include cooling the second solution to a temperature effective for precipitating biphenol dianhydride, for example, cooling to a temperature of 10 °C to 70 °C, or 25 °C to 65 °C, or 25 °C to 50 °C, and separating biphenol dianhydride from the second solution. Biphenol dianhydride can be separated from the second solution by, for example, filtration, centrifugation, etc. or a combination thereof. The separated biphenol dianhydride can be further washed with a suitable solvent (for example, with 1-6 ethanol, water, or a combination thereof). Preferably, biphenol dianhydride can be washed with methanol, water, or a combination thereof. In some embodiments, before cooling the second solution, the method may further include filtering the second solution to remove ionic species. In some embodiments, the filtration may be carried out through a filter having a pore size of 2 microns or less. Filtering the second solution can provide a third solution with a higher purity than the second solution (i.e., the third solution contains a reduced amount of ionic species relative to the second solution).

[0027] The biphenol dianhydride can be a mixture of isomers. For example, 10 wt% to 100 wt% of the biphenol dianhydride can have a double bond of the biphenyl group of the biphenol dianhydride at the 3,3'-position. Preferably, 90 wt% to 100 wt% of the biphenol dianhydride can have a double bond of the biphenyl group of the biphenol dianhydride at the 3,3'-position. Thus, the biphenol dianhydride is preferably a mixture of isomers, wherein 90 wt% to 100 wt% of the biphenol dianhydride has the following formula

[0028]

[0029] The biphenol dianhydride prepared according to the method described herein can advantageously have a low level of residual contaminants. For example, the biphenol dianhydride can contain sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, and iron ions each less than 35 ppm. The biphenol dianhydride can contain a total of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, and iron ions less than 175 ppm. The biphenol dianhydride can contain phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions each less than 30 ppm. The biphenol dianhydride can contain a total of phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions less than 50 ppm. The biphenol dianhydride can contain NaHSO3, Na2SO4, KHSO3, K2SO4, NaNO3, NaNO2, KNO3, KNO2, NaCl, KCl, CaSO4, Ca(NO3)2 each less than 30 ppm.

[0030] Another aspect of the present disclosure is a method for purifying biphenol dianhydride. The method includes removing ionic substances from a solution comprising biphenol dianhydride and a non-halogenated solvent by adsorbing the ionic substances from the solution by an adsorbent, by crystallizing biphenol dianhydride from the solution, by filtering the solution to remove the ionic substances, or a combination thereof. The ionic substances can be one or more of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, iron ions, phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions. The adsorbent can include, for example, celite, diatomaceous earth, silica, alumina, etc., or a combination thereof. After contacting the biphenol dianhydride solution with the adsorbent, optionally with stirring, the solution can preferably be filtered through a filter having a pore size of less than 40 microns to 60 microns to provide a solution comprising biphenol dianhydride and substantially free of phase transfer agent, sodium, potassium, calcium, zinc, aluminum, iron, phosphate, nitrate, nitrite, sulfate, or chloride. As used herein, "substantially free of" can mean a solution comprising less than 25 ppm each of phase transfer agent, sodium, potassium, calcium, zinc, aluminum, iron, phosphate, nitrate, nitrite, sulfate, or chloride. The non-halogenated solvent can be as described above. In some embodiments, the method can further include adding an additional solvent having a lower boiling point than the non-halogenated solvent, such as toluene, xylene, benzene, etc., or a combination thereof.

[0031] Advantageously, biphenol dianhydride purified according to the above method can have a low level of residual contaminants and a low level of ionic substances. For example, biphenol dianhydride can contain less than 35 ppm each of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, and iron ions. Biphenol dianhydride can contain less than 175 ppm in total of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, and iron ions. Biphenol dianhydride can contain less than 30 ppm each of phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions. Biphenol dianhydride can contain less than 50 ppm in total of phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions.

[0032] Biphenol dianhydride prepared or purified by the method described herein can advantageously be used in a method for preparing poly(etherimide). The method for preparing poly(etherimide) can include contacting biphenol dianhydride with an organic diamine in the presence of a non-halogenated solvent under conditions effective to provide poly(etherimide).

[0033] Biphenol dianhydride can be prepared or purified according to the methods described herein and thus advantageously has low levels of contaminants. In some embodiments, the biphenol dianhydride can contain no more than 0.5 wt% of biphenyl impurities, such as 0 wt% to 0.5 wt% of biphenyl impurities. In a particularly advantageous feature, the solution containing the dianhydride can be used directly (i.e., without separation) in the synthesis of poly(etherimide).

[0034] The organic diamine can include 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 1,18-octadecanediamine, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 4-methylnonamethylenediamine, 5-methylnonamethylenediamine, 2,5-dimethylhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 2,2-dimethylpropylenediamine, N-methyl-bis(3-aminopropyl)amine, 3-methoxyhexamethylenediamine, 1,2-bis(3-aminopropoxy)ethane, bis(3-aminopropyl)sulfide, 1,4-cyclohexanediamine, bis(4-aminocyclohexyl)methane, m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, m-xylylenediamine, p-xylylenediamine, 2-methyl-4,6-diethyl-1,3-phenylenediamine, 5-methyl-4,6-diethyl-1,3-phenylenediamine, benzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 1,5-diaminonaphthalene, bis(4-aminophenyl)methane, bis(2-chloro-4-amino-3,5-diethylphenyl)methane, bis(4-aminophenyl)propane, 2,4-bis(p-amino-tert-butyl)toluene, bis(p-amino-tert-butylphenyl)ether, bis(p-methyl-o-aminophenyl)benzene, bis(p-methyl-o-aminopentyl)benzene, 1,3-diamino-4-isopropylbenzene, bis(4-aminophenyl)sulfide, bis(4-aminophenyl)sulfone (also known as 4,4'-diaminodiphenyl sulfone (DDS)), and bis(4-aminophenyl)ether. Any regioisomers of the foregoing compounds can be used. Any of the foregoing can be used in the C 1-4 alkylated or poly(C 1-4)Alkylated derivatives, such as, polymethylated 1,6-hexanediamine. Combinations of these compounds can also be used. In some embodiments, the organic diamine is m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-oxydianiline, 3,4'-oxydianiline, 3,3'-oxydianiline, or a combination thereof. In some embodiments, the organic diamine can comprise: sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, titanium ions, phosphorus ions, and iron ions, each less than 25 ppm; and phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions, each less than 30 ppm. In some embodiments, the organic diamine used can comprise NaHSO3, Na2SO4, KHSO3, K2SO4, NaNO3, NaNO2, KNO3, KNO2, NaCl, KCl, CaSO4, Ca(NO3)2, each less than 30 ppm.

[0035] The non-halogenated solvent can comprise benzonitrile, 3-nitrotoluene, m-cresol, p-cresol, N-methylpyrrolidone, sulfolane, and 1,3-dimethyl-2-imidazolidinone, or a combination thereof. In some embodiments, the method excludes any solvent other than the non-halogenated solvent. For example, the method can exclude halogenated solvents, such as o-dichlorobenzene.

[0036] Conditions effective to provide poly(etherimide) can include: a temperature of 170 °C to 380 °C; and a solids content of 1 wt% to 50 wt%, preferably 20 wt% to 40 wt%, more preferably 25 wt% to 35 wt%. The polymerization can be carried out for 2 hours to 36 hours, preferably 6 hours to 16 hours. The polymerization can be carried out under reduced pressure, atmospheric pressure, or high pressure.

[0037] In some embodiments, the method can also optionally include adding a low-boiling co-solvent to the polymerization. Preferably, the low-boiling solvent is used to remove water from the polymerization reaction by azeotropic distillation. Suitable low-boiling co-solvents can include, for example, toluene, benzene, xylene, etc., or a combination thereof.

[0038] The method may also optionally use various chain terminators or capping agents, and thus the poly(etherimide) may also optionally contain at least one chain end derived from a chain terminator. Chain terminators limit the rate of molecular weight growth and can thus be used to control the molecular weight in the poly(etherimide). Exemplary chain terminators include certain monoamines (e.g., aniline), monoanhydrides (e.g., phthalic anhydride), monophenol compounds, etc. In some embodiments, the chain terminator may preferably be a monoamine chain terminator or a monoanhydride chain terminator, more preferably aniline or phthalic anhydride. However, it should be understood that the poly(etherimide) disclosed herein can be produced to have any desired weight-average molecular weight (Mw) with any capping.

[0039] In some embodiments, the organic diamine, the chain terminator (when present), or both may have low levels of inorganic contaminants, e.g., phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions each less than 50 ppm or less than 25 ppm; and sodium ions, potassium ions, zinc ions, calcium ions, aluminum ions, iron ions, and phosphorus ions each less than 50 ppm or less than 35 ppm.

[0040] In some embodiments, no catalyst is used in the polymerization of the poly(etherimide).

[0041] Advantageously, the polymerization carried out according to the present invention can remain homogeneous throughout the polymerization process. This can facilitate the preparation of high molecular weight polymers. In some embodiments, the poly(etherimide) may have a weight-average molecular weight greater than 25,000 grams per mole, e.g., greater than 25,000 grams per mole to 35,000 grams per mole. The molecular weight can be determined by gel permeation chromatography (GPC) relative to a polystyrene standard, as further described in the following working examples.

[0042] The method of preparing poly(etherimide) may optionally include a devolatilization step. Devolatilization can achieve low levels of residual volatiles in the final polymer product, and devolatilization can also be used to complete the end groups in the polymer product. In some embodiments, by devolatilization, optionally under reduced pressure, most of any solvent can be removed and any residual volatiles can be removed from the polymer product. In other embodiments, the polymerization reaction is carried out in a solvent to a desired level of completion, and then the polymerization reaction is substantially completed in at least one devolatilization step after the initial reaction in solution. Devices for devolatilizing the polymer mixture and reducing the solvent and other volatiles to low levels required for good melt processability are generally capable of heating at high temperatures under vacuum and have the ability to quickly generate a high surface area for removing volatiles. The mixing section of such devices is generally capable of supplying sufficient power to pump, agitate, and stir the high-temperature amorphous polyphenylene ether sulfone and poly(etherimide) melts, which may be very viscous. Suitable devolatilization devices include, but are not limited to, wiped film evaporators and devolatilizing extruders, especially twin screw extruders having multiple venting sections. In some embodiments, the method may also optionally include devolatilizing the poly(etherimide) at 360 to 390 °C for 1 to 30 minutes.

[0043] Poly(etherimide) prepared according to the methods described herein and using biphenol dianhydride prepared or purified according to the present disclosure can advantageously have low levels of residual impurities. Specifically, the poly(etherimide) can contain: sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, and iron ions each less than 25 ppm; and phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions each less than 30 ppm.

[0044] The poly(etherimide) prepared by the method according to the present disclosure can be particularly useful for forming various articles. The poly(etherimide) can be formed into articles using suitable techniques (e.g., melt processing techniques). Melt molding methods can include injection molding, extrusion molding, blow molding, rotational molding, coining, and injection blow molding. For example, the melt molding method can be injection molding. The poly(etherimide) can be formed into sheets or films by casting, blowing, or extrusion. These sheets or films can also be thermoformed into articles and structures that can be oriented from the melt or at a later stage in the processing of the composition. The poly(etherimide) can be overmolded onto articles made of different materials or by different methods. Articles can also be formed using techniques such as compression molding or ram extruding. Articles can also be machined into other shapes. Exemplary articles include fibers, films, sheets, foams, filaments, molded articles, extruded articles, or powders. The poly(etherimide) of the present disclosure can also be particularly suitable for optoelectronic applications. Specifically, the poly(etherimide) can be used in optoelectronic articles such as emitters, receivers, connectors, lenses, waveguides, etc.

[0045] Accordingly, methods for preparing and purifying biphenol dianhydride having low levels of residual contaminants are provided herein. The biphenol dianhydride of the present disclosure can be used to prepare rigid, high molecular weight biphenyl-containing poly(etherimide) that can be particularly useful for various applications (e.g., in optical articles). Accordingly, the present disclosure provides significant improvements.

[0046] The present disclosure is further illustrated by the following examples, which are non-limiting.

[0047] Examples

[0048] The materials used in the following examples are described in Table 1.

[0049] Table 1

[0050]

[0051]

[0052]

[0053] The molecular weights of all polymers in the following examples were determined by gel permeation chromatography (GPC) analysis using a Waters 2695 separation module equipped with a Polymer Lab Plgel 5 micron MIXED-C column and a Waters 2487 PDA detector at 254 nm. Unless otherwise stated, elution was carried out with an isocratic solvent system of dichloromethane at 1 mL / min, and the polymer molecular weights were reported relative to polystyrene standards.

[0054] All ultra-high performance liquid chromatography (UPLC) analyses in the following examples were carried out at 35 °C on a Waters ACQUITY UPLC BEH C18 1.7 μm 2.1×50 mm column. PDA detection was carried out at 254 nm with a flow rate of 0.313 mL / min. The gradient method was used with a dual solvent system of acetonitrile and acidic water (4 LDI H2O + 3 mL 85% H3PO4). It should be noted that the UPLC analysis of BPoDA showed a small amount of BPo anhydride-diacid (“BpoAnhDA”), which was due to partial hydrolysis occurring during the analysis.

[0055] The residual levels of all metals (sodium, potassium, zinc, calcium, aluminum, iron, titanium, phosphorus) in the following examples were determined by inductively coupled plasma digestion (ICP-Dig) method using an ICP spectrometer equipped with axial and / or radial viewing, GemCone and / or ultrasonic nebulizer and a microwave digestion system equipped with an appropriate set of sample digestion vessels. Samples were prepared using concentrated nitric acid, hydrochloric acid, sulfuric acid, and / or hydrofluoric acid (ultrapure grade).

[0056] The residual levels of anions (sulfate, chloride, phosphate, nitrate, nitrite) present in BPoDA and poly(etherimide) samples were measured by extraction ion chromatography (IC-extract). The BPoDA samples were dissolved in dichloromethane, and the poly(etherimide) samples were dissolved in dichloromethane with the addition of hexafluoroisopropanol (HFIP) to aid dissolution. The solutions were then extracted with deionized water and the aqueous extracts were then analyzed using a calibrated Dionex ICS2000 instrument.

[0057] The residual levels of anions (sulfate, chloride, phosphate, nitrate, nitrite) present in BPoTA samples were measured by total ion chromatography combustion (IC-total) using a calibrated Dionex ICS2000 instrument.

[0058] Example 1 below uses BPoTA with the following curves: ICP-Dig: sodium (534 ppm), potassium (12.6 ppm), zinc (14 ppm), calcium (19 ppm), aluminum (217 ppm), iron (527 ppm), titanium (5.7 ppm), phosphorus (7.8 ppm), nickel (182 ppm); UPLC: 3,3'-BPoTA and isomers (97.8%).

[0059] Comparative Example 1

[0060] Add 3,3'-BPoTA (6 g, 11.66 mmol), toluene (100 g, 103 mL), and acetic anhydride (8.70 g, 8 mL) to a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, Dean-Stark separator, and condenser. Then heat the mixture to 140 °C in an oil bath under nitrogen. Fresh toluene was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. After 9 hours, UPLC analysis indicated that the reaction was complete, and a light gray precipitate in toluene was observed. Then cool the mixture to room temperature. Collect the product by filtration and then wash it successively with hot DI water (2 × 20 mL). Dry the product in a vacuum oven at 140 to 145 °C until a constant mass is obtained. In this way, 3.18 g of 3,3'-BPoDA product was collected, with a yield of 56.9%. UPLC: BPoDA isomers (97%); ICP-Dig: sodium (511 ppm), potassium (8.7 ppm), zinc (5.3 ppm), calcium (18.5 ppm), aluminum (12.9 ppm), iron (15.4 ppm), titanium (0 ppm), phosphorus (24 ppm).

[0061] Examples 2 to 10 below use BPoTA with the following curves: ICP-Dig: sodium (138 ppm), potassium (9 ppm), zinc (2 ppm), calcium (6 ppm), aluminum (2 ppm), iron (20 ppm), titanium (0 ppm), phosphorus (7 ppm); IC - total: sulfate (278.8 ppm), phosphate (2.4 ppm), chloride (1.2 ppm), fluoride (3 ppm), nitrite (1.5 ppm), nitrate (<0.5 ppm); UPLC: 3,3'-BPoTA and isomers (98.50%).

[0062] Comparative Example 2

[0063] 3,3’-BPoTA (30 g, 58.31 mmol), acetic acid (55 g, 52 mL), and acetic anhydride (55 g, 51 mL) were added to a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser. The flask was then placed in an oil bath and heated to 130 °C under nitrogen. After 5 to 6 h, UPLC analysis indicated completion of the reaction, and a light gray precipitate was observed in the solvent mixture. The mixture was then cooled to room temperature. The product was collected by filtration and then washed successively with hot DI water (2 × 35 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this manner, 22.60 g (81% yield) of 3,3’-BPoDA product was collected. UPLC: BPoDA isomer (97.8%); ICP-Dig: sodium (5 ppm), potassium (12 ppm), zinc (1 ppm), calcium (13 ppm), aluminum (4 ppm), iron (11 ppm), titanium (0 ppm), phosphorus (6 ppm); IC-extract: sulfate (21.0 ppm), chloride (<0.5 ppm), phosphate (1.6 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0064] Example 3

[0065] In a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser, the above 3,3’-BPoTA (15 g, 29.15 mmol) and NMP (56 g, 55 mL) were placed. Then the flask was placed in an oil bath at 160 °C under nitrogen. Fresh NMP was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. After 3 to 4 hours, UPLC analysis indicated that the reaction was complete. Then the mixture was cooled to 50 °C. DI water (100 mL) was added to the homogeneous solution of 3,3’-BPoDA in NMP to form an orange precipitate. The product was collected by filtration and then washed with methanol (50 °C, 3 × 20 mL), followed by washing with DI water (60 to 70 °C, 2 × 20 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, 13.37 g of the 3,3’-BPoDA product was collected, with a yield of 95.90%. UPLC: BPoDA isomer (98.99%); ICP-Dig: sodium (33 ppm), potassium (15 ppm), zinc (3 ppm), calcium (22 ppm), aluminum (4 ppm), iron (22 ppm), titanium (0 ppm), phosphorus (7 ppm); IC-extract: sulfate (3 ppm), phosphate (<0.5 ppm), nitrite (<0.5 ppm), nitrate (<0.5 ppm), chloride (<0.5 ppm), fluoride (0.8 ppm).

[0066] Example 4

[0067] 3,3’-BPoTA (15 g, 29.15 mmol) and DMZ (56 g, 53 mL) were added to a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser. The flask was then placed in an oil bath at 160 °C under nitrogen. Fresh DMZ was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. After 3 to 4 hours, UPLC analysis indicated that the reaction was complete. The mixture was then cooled to 50 °C to form a light white precipitate in DMZ. The product was collected by filtration and then washed with methanol (50 °C, 3 × 20 mL), followed by washing with DI water (60 to 70 °C, 2 × 20 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, 11.82 g of 3,3’-BPoDA product was collected, with a yield of 84.80%. UPLC: BPoDA isomer (99.15%); ICP-Dig: sodium (10 ppm), potassium (28 ppm), zinc (0 ppm), calcium (6 ppm), aluminum (4 ppm), iron (7 ppm), titanium (0 ppm), phosphorus (8 ppm); IC-extract: sulfate (1.5 ppm), phosphate (<0.5 ppm), nitrite (6.1 ppm), nitrate (<0.5 ppm), chloride (<0.5 ppm), fluoride (1.2 ppm).

[0068] Example 5

[0069] 3,3’-BPoTA (15 g, 29.15 mmol) and m-cresol (56 g, 54 mL) were added to a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser. The flask was then placed in an oil bath at 160 °C under nitrogen. Fresh m-cresol was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. After 3 to 4 hours, UPLC analysis indicated that the reaction was complete. The mixture was then cooled to 50 °C to form an off-white precipitate in m-cresol. The product was collected by filtration and then washed with methanol (50 °C, 3 × 20 mL), followed by washing with DI water (60 to 70 °C, 2 × 20 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, 12.31 g of 3,3’-BPoDA product was collected, with a yield of 88.26%. UPLC: BPoDA isomer (98.70%); ICP-Dig: sodium (15 ppm), potassium (13 ppm), zinc (3 ppm), calcium (15 ppm), aluminum (2 ppm), iron (5 ppm), titanium (0 ppm), phosphorus (8 ppm); IC-extract: sulfate (4.3 ppm), phosphate (<0.5 ppm), nitrite (<0.5 ppm), nitrate (<0.5 ppm), chloride (<0.5 ppm), fluoride (1.3 ppm).

[0070] Example 6

[0071] 3,3’-BPoTA (15 g, 29.15 mmol) and benzonitrile (56 g, 56 mL) were added to a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser. The flask was then placed in an oil bath at 160 °C under nitrogen. Fresh benzonitrile was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. After 3 to 4 hours, UPLC analysis indicated that the reaction was complete. The mixture was then cooled to 50 °C to form a light grayish-white precipitate in benzonitrile. The product was collected by filtration and then washed with methanol (50 °C, 2 × 30 mL), followed by washing with DI water (60 to 70 °C, 2 × 20 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, 12.67 g of the 3,3’-BPoDA product was collected, with a yield of 90.80%. UPLC: BPoDA isomer (99.16%); ICP-Dig: sodium (9 ppm), potassium (14 ppm), zinc (2 ppm), calcium (7 ppm), aluminum (3 ppm), iron (59 ppm), titanium (0 ppm), phosphorus (11 ppm); IC extract: sulfate (5.1 ppm), phosphate (<0.5 ppm), nitrite (<0.5 ppm), nitrate (<0.5 ppm), chloride (<0.5 ppm), fluoride (<0.5 ppm).

[0072] Example 7

[0073] 3,3’-BPoTA (60 g, 116.63 mmol) and benzonitrile (504 g, 504 mL) were added to a 1000 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser. The flask was then placed in an oil bath at 160 °C under nitrogen. Fresh benzonitrile was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. After 3 hours, UPLC analysis indicated that the reaction was complete. The homogeneous solution was then heated to 170 °C. The solution was transferred to a Mott filter (preheated to 170 °C, 2-μm filter medium), and the solution was held at this temperature for 15 to 20 minutes, followed by filtration under pressure (10 to 20 psig) to collect the BPoDA solution in benzonitrile. UPLC: BPoDA isomers (98.90%); Metal / anion curve after Mott filtration: ICP-Dig: sodium (7 ppm), potassium (14 ppm), zinc (2 ppm), calcium (9 ppm), aluminum (0 ppm), iron (4 ppm), titanium (0 ppm), phosphorus (8 ppm), chromium (1 ppm), copper (0 ppm), nickel (0 ppm), magnesium (0 ppm), manganese (0 ppm); IC extract: sulfate (12 ppm), phosphate (<0.5 ppm), nitrite (<0.5 ppm), nitrate (<0.5 ppm), chloride (<0.5 ppm), fluoride (<0.5 ppm), bromide (<0.5 ppm).

[0074] Example 8

[0075] The solution from above (Example 7) was then concentrated to 15 to 20 wt% solids and cooled to 50 °C to form a light grayish-white precipitate in benzonitrile. The product was collected by filtration and then washed with methanol (50 °C, 3 × 35 mL), followed by washing with DI water (60 to 70 °C, 2 × 50 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, 37.94 g of the 3,3’-BPoDA product was collected, with a yield of 68%. Isolated DA: UPLC: Metal / anion curve of BPoDA isomers (99.30%); ICP-Dig: sodium (7 ppm), potassium (17 ppm), zinc (2 ppm), calcium (11 ppm), aluminum (0 ppm), iron (1 ppm), titanium (0 ppm), phosphorus (7 ppm), chromium (1 ppm), copper (0 ppm), magnesium (0 ppm), nickel (0 ppm), manganese (0 ppm); IC extract: sulfate (12.1 ppm), phosphate (<0.5 ppm), nitrite (<0.5 ppm), nitrate (<0.5 ppm), chloride (<0.5 ppm), fluoride (<0.5 ppm), bromide (<0.5 ppm).

[0076] Example 9 used BPoDA with the following curves: ICP-Dig: sodium (157 ppm), potassium (<10 ppm), zinc (12.2 ppm), calcium (12.9 ppm), aluminum (7.2 ppm), iron (20.8 ppm), titanium (<1 ppm), phosphorus (0 ppm); IC extract: sulfate (314.6), chloride (1.3), nitrate (<0.5), nitrite (0.5), phosphate (<0.5); UPLC: 3,3'-BPoDA (92.15%), BPoAnhDA (7.47%).

[0077] Example 9

[0078] A mixture of crude 3,3'-BPoDA (1.5 g, 3.13 mmol) and m-cresol (15 mL) was charged into a 100 mL three-necked round-bottom flask equipped with a magnetic stir bar, a Dean-Stark separator, and a condenser. The flask was heated to 200 °C, and then the solution was quickly transferred to a preheated (150 °C) glass syringe fitted with a 0.45 micron PTFE filter. The solution was filtered onto a watch glass, and the solvent was removed on a hot plate in a fume hood until the solid dianhydride was dry. UPLC: 3,3'-BPoDA + BPoAnhDA (100%); ICP-Dig: sodium (23.4 ppm), potassium (<10 ppm), zinc (16.3 ppm), calcium (17.8 ppm), aluminum (7.9 ppm), iron (12.5 ppm), titanium (<1 ppm), phosphorus (0 ppm); IC extract: sulfate (<0.5), chloride (1.3), nitrate (<0.5), nitrite (<0.5), phosphate (<0.5).

[0079] Example 10

[0080] Charge a 1 L round-bottom flask with 3,3’-BPoTA (20.08 g) and m-cresol (168 g). Stir the mixture with a overhead stirrer at 150 rpm and heat to 180 °C. Once the UPLC indicates that the BPoTA peak has completely disappeared, maintain the reaction mixture at 180 °C for an additional 30 minutes. Then prepare a coarse sintered glass filter funnel with 3 inches of Celite 545. Then filter the 3,3’-BPoDA solution through Celite at 180 °C using vacuum. Then pass the filtrate through Celite again and then allow it to cool to ambient temperature. Collect the resulting 3,3’-BPoDA solid on a #4 Whatman filter paper. Wash the solid cake with MeOH (2 x 50 mL), followed by DI water (2 x 50 mL). Then dry the purified 3,3’-BPoDA in a vacuum oven at 90 °C until a consistent mass is obtained to afford 5.46 g of the dianhydride as a white solid (29.24% yield). UPLC: BPoDA isomers + BPoAnhDA (98.91%); ICP-Dig: sodium (31.3 ppm), potassium (6.98 ppm), zinc (5.34 ppm), calcium (11.3 ppm), aluminum (4.34 ppm), iron (7.78 ppm), titanium (<1 ppm), phosphorus (<1 ppm); IC extract: sulfate (15.1 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm), chloride (5.4 ppm).

[0081] Multiple conditions were used to determine which were most effective in purifying BPoDA from organic and inorganic contaminants. The different conditions evaluated included using different organic solvents / reagents followed by purification steps which included crystallization, Mott filtration, Mott filtration followed by crystallization, filtration alone or filtration through an adsorbent (such as Celite diatomaceous earth) followed by crystallization. The results are summarized in Table 2 which shows that cyclization of BPoTA to BPoDA in non-halogenated solvents (such as, NMP, DMZ, m-cresol and benzonitrile) provides homogeneous solutions and purification of these homogeneous solutions using the methods described above yields dianhydrides with high purity and very low levels of inorganic contaminants (especially sodium ions and sulfate ions). Further, the use of these solvents allows for a higher weight percentage of solids which will contribute to achieving higher throughput and improved efficiency. On the other hand, comparative examples involving the use of low-boiling toluene and acetic acid / acetic anhydride form slurries even at lower weight percentages of solids. Further, the use of toluene (Example 1) provides the dianhydride product especially with very high levels of sodium ions. When using a mixture of acetic acid and acetic anhydride (Example 2), the resulting product shows lower levels of metal ions and sulfates. However, this method involves the use of highly corrosive chemicals. Further, the presence of residues of these chemicals will have an adverse effect on the polymerization step and does not allow for the construction of high molecular weights. It was found that the use of non-halogenated solvents in combination with different purification methods performs very effectively.

[0082] Table 2

[0083]

[0084]

[0085] * Denotes comparative examples

[0086] ** From BPoDA starting material

[0087] The following examples describe the preparation of poly(etherimide) in non-halogenated solvents. Examples 11 to 26 used 3,3’-BPoDA with the following profiles: ICP-Dig: sodium (5 ppm), potassium (41 ppm), zinc (2 ppm), calcium (4 ppm), aluminum (3 ppm), iron (9 ppm), titanium (0 ppm), phosphorus (10 ppm); IC extract: sulfate (4.6 ppm), chloride (<0.5 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); UPLC: 3,3’-BPoDA (96.26%), BPoAnhDA (3.74%).

[0088] Examples 11 to 26 used m-PD with the following curves: ICP-Dig: sodium (1 ppm), potassium (12 ppm), zinc (0 ppm), calcium (3 ppm), aluminum (3 ppm), iron (0 ppm), titanium (0 ppm), phosphorus (5 ppm); IC extract: sulfate (<0.5 ppm), chloride (130.7 ppm), phosphate (<0.5 ppm), nitrate (1.9 ppm), nitrite (<0.5 ppm).

[0089] Example 11

[0090] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (20.81 g, 43.49 mmol), phthalic anhydride (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4’-DDS (5.08 g, 20.5 mmol), and benzonitrile (109 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0091] After 23 minutes, the oil bath temperature reached 140 °C, and the glue-ball stage (a biphasic mixture containing a prepolymer of solid matter) was observed, at which point the stirring was reduced to 80 to 100 rpm. After an additional 4 minutes, the oil bath temperature reached 148 °C, and the mixture became a homogeneous yellow-orange solution, at which point the stirring was increased to 200 rpm. The target oil bath temperature of 200 °C was obtained within 40 to 45 minutes of heating. After a total of 2 hours 45 minutes, 46 g of distillate was removed from the separator to obtain a 30 wt% solid solution, and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours, the homogeneous yellow-orange polymer solution was poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. ICP-Dig: sodium (14 ppm), potassium (14 ppm), zinc (12 ppm), calcium (14 ppm), aluminum (11 ppm), iron (8 ppm), titanium (0 ppm), phosphorus (16 ppm); IC extract: sulfate (10.7 ppm), chloride (3 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0092] Example 12

[0093] In a 250 mL three-neck round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (20.81 g, 43.49 mmol), m-PD (2.70 g, 25.0 mmol), 4,4’-DDS (5.08 g, 20.5 mmol), and benzonitrile (109 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 120 to 150 rpm.

[0094] After 18 minutes, the oil bath temperature reached 159 °C, and the gum ball stage (a biphasic mixture containing a prepolymer of solid material) was observed. After an additional 2 minutes, the temperature was raised to 169 °C, and a homogeneous yellow solution was obtained. At this point, the stirring was increased to 200 rpm. After a total heating of 60 minutes, the target oil bath temperature of 200 °C was reached, and 46 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids. The nitrogen purge was reduced to 0.5 scfh. After a total of 2 hours 10 minutes, PA (0.726 g, 4.90 mmol) and benzonitrile (10 mL) were added to the mixture and the nitrogen flow was increased. After an additional 40 minutes, 13 g of distillate was removed from the separator, and the nitrogen flow was reduced to 0.5 scfh. After a total heating of 7 hours 30 minutes, a large sample was removed, and devolatilization was carried out under nitrogen at 380 to 385 °C (hot block) for 20 minutes. GPC: weight average Mw = 28,005 g / mol; Mn = 13,348 g / mol; PDI = 2.10; Mz / Mw = 1.35; DSC (Tg) = 280.6 °C.

[0095] The remaining portion of the polymer solution was heated for a total of 24.5 hours and then poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. GPC: weight average Mw = 28,401 g / mol; Mn = 13,566 g / mol; PDI = 2.09; Mz / Mw = 1.36. ICP-Dig: sodium (5.1 ppm), potassium (7.1 ppm), zinc (22.7 ppm), calcium (9.9 ppm), aluminum (<0.1 ppm), iron (<0.1 ppm), titanium (0 ppm), phosphorus (11 ppm); IC extract: sulfate (6.5 ppm), chloride (7.6 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); DSC (Tg) = 278.6 °C.

[0096] Example 13

[0097] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (20.81 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4’-DDS (5.08 g, 20.5 mmol), and 3-nitrotoluene (109 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0098] After 22 minutes, the oil bath temperature reached 178 °C, and the gum ball stage (a biphasic mixture containing a prepolymer of solid material) was observed, at which point the stirring was reduced to 100 to 120 rpm. Within a few minutes, the oil bath temperature reached 181 °C, and the mixture became a homogeneous orange solution, at which point the stirring was increased to 200 rpm. The target oil bath temperature of 200 °C was obtained within 40 to 45 minutes of heating. After a total of 3 hours, 46 g of distillate was removed from the separator to obtain a 30 wt% solid solution, and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours, the homogeneous orange polymer solution was poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. ICP-Dig: sodium (8 ppm), potassium (6 ppm), zinc (27 ppm), calcium (12 ppm), aluminum (4 ppm), iron (9 ppm), titanium (0 ppm), phosphorus (12 ppm); IC extract: sulfate (8.8 ppm), chloride (<0.5 ppm), phosphate (<0.5 ppm), nitrate (2 ppm), nitrite (<0.5 ppm).

[0099] Example 14

[0100] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (20.81 g, 43.49 mmol), phthalic anhydride (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4’-DDS (5.08 g, 20.5 mmol), and p-cresol (109 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 120 rpm.

[0101] After 22 minutes, the oil bath temperature reached 147 °C and the mixture became a homogeneous yellow solution, at which point the stirring was increased to 200 rpm. The target oil bath temperature of 200 °C was obtained within 45 minutes of heating. After an additional 75 minutes, 46 g of distillate was removed from the separator to obtain a 30 wt% solid solution, and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours and 35 minutes, the homogeneous yellow polymer solution was poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. ICP - Dig: Sodium (11.9 ppm), Potassium (10.8 ppm), Zinc (9.1 ppm), Calcium (15.3 ppm), Aluminum (20.9 ppm), Iron (11.5 ppm), Titanium (3.9 ppm), Phosphorus (11 ppm); IC extract: Sulfate (16 ppm), Chloride (<0.5 ppm), Phosphate (<0.5 ppm), Nitrate (4.3 ppm), Nitrite (<0.5 ppm).

[0102] Example 15

[0103] In a 250 mL three - necked round - bottom flask equipped with a Dean - Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’ - BPoDA (20.81 g, 43.49 mmol), phthalic anhydride (0.726 g, 4.90 mmol), m - PD (2.70 g, 25.0 mmol), 4,4’ - DDS (5.08 g, 20.5 mmol), and m - cresol (109 g) were added. The flask was placed in an oil bath at 25 °C and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0104] After 27 minutes, the oil bath temperature reached 135 °C and the mixture became a homogeneous orange solution, at which point the stirring was increased to 200 rpm. The target oil bath temperature of 200 °C was obtained within 40 to 45 minutes of heating. After a total of 3 hours, 46 g of distillate was removed from the separator to obtain a 30 wt% solid solution, and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours, the homogeneous orange polymer solution was poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. ICP - Dig: Sodium (20 ppm), Potassium (13 ppm), Zinc (20 ppm), Calcium (26 ppm), Aluminum (11 ppm), Iron (11 ppm), Titanium (0 ppm), Phosphorus (14 ppm); IC extract: Sulfate (7.6 ppm), Chloride (2.8 ppm), Phosphate (<0.5 ppm), Nitrate (<0.5 ppm), Nitrite (<0.5 ppm).

[0105] Example 16

[0106] In a 500 mL three-necked round-bottom flask equipped with a Dean-Stark separator, a condenser, a mechanical stirrer, and a nitrogen inlet (2 scfh), 3,3'-BPoDA (41.61 g, 86.98 mmol), m-PD (5.408 g, 50.01 mmol), 4,4'-DDS (10.16 g, 40.91 mmol), and sulfolane (99.4 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 240 °C with stirring at 150 to 200 rpm.

[0107] After 15 minutes, the oil bath temperature reached 160 °C, and a homogeneous orange-yellow solution was observed. After an additional 5 minutes, the temperature reached 193 °C, and the stirring was increased to 250 rpm. After heating for a total of three hours, the oil bath temperature reached 240 °C, and then phthalic anhydride (1.452 g, 9.803 mmol) was added. After an additional 3 hours, a sample was taken for analysis. GPC: weight-average Mw = 27,680 g / mol; Mn = 11,951 g / mol; PDI = 2.32; Mz / Mw = 1.38; IC extract: sulfate (13.7 ppm), chloride (2.9 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0108] Example 17

[0109] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, a condenser, a mechanical stirrer, and a nitrogen inlet (2 scfh), 3,3'-BPoDA (20.81 g, 43.49 mmol), phthalic anhydride (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4'-DDS (5.08 g, 20.5 mmol), and NMP (109 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0110] After 10 minutes, the oil bath temperature reached 125 °C, and the mixture became a homogeneous yellow-orange solution, at which point the stirring was increased to 200 rpm. The target oil bath temperature of 200 °C was obtained within 77 minutes of heating, after which 46 g of distillate was removed from the separator to obtain a 30 wt% solid solution, and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours 35 minutes, the homogeneous light orange polymer solution was poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (hot block) for 20 minutes. ICP-Dig: sodium (16.1 ppm), potassium (12.5 ppm), zinc (47.3 ppm), calcium (24.6 ppm), aluminum (2.6 ppm), iron (16.1 ppm), titanium (2.5 ppm), phosphorus (9.2 ppm); IC extract: sulfate (22.2 ppm), chloride (26.4 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0111] Example 18

[0112] In a 250 mL three-neck round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3'-BPoDA (20.81 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4'-DDS (5.08 g, 20.5 mmol), and DMZ (109 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0113] After 10 minutes, the oil bath temperature reached 128 °C, and the mixture became a homogeneous orange solution, at which point the stirring was increased to 200 rpm. The target oil bath temperature of 200 °C was obtained within 40 to 45 minutes of heating. After a total of 3.5 hours, 46 g of distillate was removed from the separator to obtain a 30 wt% solid solution, and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours 35 minutes, the homogeneous orange polymer solution was poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (hot block) for 20 minutes. ICP-Dig: sodium (9.9 ppm), potassium (10.1 ppm), zinc (32.8 ppm), calcium (19.4 ppm), aluminum (2.1 ppm), iron (8.5 ppm), titanium (1.7 ppm), phosphorus (8.8 ppm); IC extract: sulfate (12.6 ppm), chloride (4.9 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0114] Example 19

[0115] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3'-BPoDA (20.81 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4'-DDS (5.08 g, 20.5 mmol), and DMA (109 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0116] After 27 minutes, the oil bath temperature reached 112 °C, and the mixture became a homogeneous orange solution, at which point the stirring was increased to 200 rpm. The target oil bath temperature of 200 °C was obtained within 75 minutes of heating, after which 46 g of distillate was removed from the separator to obtain a 30 wt% solid solution, and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours and 25 minutes, the homogeneous orange polymer solution was poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. ICP-Dig: sodium (10 ppm), potassium (7 ppm), zinc (49 ppm), calcium (13 ppm), aluminum (4 ppm), iron (10 ppm), titanium (0 ppm), phosphorus (10 ppm); IC extract: sulfate (7.7 ppm), chloride (6.1 ppm), phosphate (<0.5 ppm), nitrate (2.4 ppm), nitrite (<0.5 ppm).

[0117] Example 20

[0118] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3'-BPoDA (20.81 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4'-DDS (5.08 g, 20.5 mmol), and ethyl benzoate (110 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0119] After 40 minutes, the oil bath temperature reached 170 °C and the gum ball stage was observed. After an additional 5 minutes, the oil bath temperature reached 179 °C and the mixture became a homogeneous orange solution, at which point the stirring was increased to 200 rpm. The target oil bath temperature of 200 °C was obtained within 77 minutes of heating, after which 46 g of distillate was removed from the separator to obtain a 30 wt% solid solution, and then the nitrogen purge was reduced to 0.5 scfh. After an additional 1 hour of heating at 200 °C, the mixture became biphasic and a doughy polymer was observed. After a total of 7 hours 20 minutes, the mixture was poured and scraped into a foil pan and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. ICP-Dig: sodium (16 ppm), potassium (10 ppm), zinc (11 ppm), calcium (18 ppm), aluminum (8 ppm), iron (32 ppm), titanium (0 ppm), phosphorus (13 ppm); IC extract: sulfate (6.2 ppm), chloride (1.7 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0120] Example 21

[0121] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (20.81 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4’-DDS (5.08 g, 20.5 mmol), and diphenyl ether (109 g) were added. The flask was placed in an oil bath at 25 °C and the oil bath was heated to 200 °C with stirring at 120 rpm.

[0122] After 50 minutes, the oil bath temperature reached 180 °C and the glue ball stage (a biphasic mixture containing a prepolymer of solid matter) was observed. After an additional 7 minutes, the oil bath temperature reached 192 °C and the reaction became a biphasic mixture, at which point the stirring was increased to 200 rpm. After heating for a total of 3 hours, the mixture became a viscous opaque mixture and the water distillate was removed from the separator. After a total of 7 hours and 35 minutes, the mixture was scraped into a foil dish with a metal spatula and cooled to ambient temperature. The sample was devolatilized for 20 minutes at 380 to 385 °C under nitrogen (using a hot block). ICP-Dig: sodium (8.6 ppm), potassium (8.4 ppm), zinc (28.1 ppm), calcium (18.6 ppm), aluminum (2 ppm), iron (23.4 ppm), titanium (1.7 ppm), phosphorus (11.1 ppm); IC extract: sulfate (3.1 ppm), chloride (1.9 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0123] Example 22

[0124] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3'-BPoDA (20.81 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4'-DDS (5.08 g, 20.5 mmol), and phenyl ethyl ether (109 g) were added. The flask was placed in an oil bath at 25 °C and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0125] After 25 minutes, the oil bath temperature reached 190 °C and the reaction became a biphasic mixture. After an additional 3 minutes, the oil bath temperature reached 195 °C. After another 12 minutes, the mixture thinned and the stirring was increased to 200 rpm. After an additional 2 minutes, the target oil bath temperature of 200 °C was reached and 46 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids.

[0126] After heating for a total of 3.5 hours, the mixture became a viscous taffy-like thick mixture. Heating was continued, and it was observed that the polymer solid climbed up the stirrer shaft. After a total of 7 hours and 45 minutes, the mixture was scraped into a foil dish with a metal spatula and cooled to ambient temperature. The sample was devolatilized for 20 minutes at 380 to 385 °C under nitrogen (using a hot block). ICP-Dig: sodium (16 ppm), potassium (12 ppm), zinc (13 ppm), calcium (27 ppm), aluminum (7 ppm), iron (27 ppm), titanium (0 ppm), phosphorus (16 ppm); IC extract: sulfate (7.7 ppm), chloride (1.2 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0127] Example 23

[0128] In a 250 mL three-neck round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (20.81 g, 43.49 mmol), phthalic anhydride (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4’-DDS (5.08 g, 20.5 mmol), and triglyme (108 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 120 rpm.

[0129] After 35 minutes, the oil bath temperature reached 185 °C, and a homogeneous mixture was observed. After an additional 5 minutes, the stirring was increased to 200 rpm. After heating for a total of 45 minutes, the mixture became opaque and reached the target oil bath temperature of 200 °C. After an additional 1 hour of heating, 46 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids. The nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours and 20 minutes, the mixture was poured and scraped onto a foil dish with a metal spatula and cooled to ambient temperature. The sample was devolatilized for 20 minutes at 380 to 385 °C under nitrogen (using a hot block). ICP-Dig: sodium (17 ppm), potassium (31 ppm), zinc (17 ppm), calcium (24 ppm), aluminum (9 ppm), iron (26 ppm), titanium (0 ppm), phosphorus (13 ppm); IC extract: sulfate (3.4 ppm), chloride (0.7 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0130] Comparative Example 24

[0131] In a 250 mL three-neck round bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3'-BPoDA (20.81 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.70 g, 25.0 mmol), 4,4'-DDS (5.08 g, 20.5 mmol), and o-DCB (109 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 120 rpm.

[0132] After 35 minutes, the oil bath temperature reached 155 °C, and the gel ball stage (a biphasic mixture containing a prepolymer of solid material) was observed, during which the stirring was reduced to 80 to 100 rpm. After an additional 8 minutes, the oil bath temperature reached 173 °C, and the mixture became a homogeneous yellow solution. Then the stirring was increased to 200 rpm.

[0133] After heating for a total of 75 minutes, the target oil bath temperature of 200 °C was reached. At this time, 46 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids, and the nitrogen purge was reduced to 0.5 scfh. After a total of 6 hours and 45 minutes, the polymerization became a viscous biphasic mixture. After an additional 70 minutes, the mixture was poured and scraped onto a foil tray with a metal spatula and cooled to ambient temperature. The sample was devolatilized at 380 to 385 °C (using a hot block) under nitrogen for 20 minutes. ICP-Dig: sodium (16 ppm), potassium (11 ppm), zinc (7 ppm), calcium (25 ppm), aluminum (6 ppm), iron (15 ppm), titanium (0 ppm), phosphorus (12 ppm); IC extract: sulfate (4.6 ppm), chloride (1.4 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0134] Comparative Example 25

[0135] In a 250 mL three-neck round bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3'-BPoDA (20.8 g, 43.6 mmol), PA (0.691 g, 4.67 mmol), m-PD (2.70 g, 25.0 mmol), 4,4'-DDS (5.08 g, 20.5 mmol), and DMSO (57.1 mL) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 to 205 °C with stirring at 150 to 200 rpm.

[0136] After 21 minutes, the oil bath temperature reached 106 °C and a homogeneous yellow-orange solution was observed. After a total of 102 minutes, the target temperature was reached and 21 g of distillate was removed from the separator to obtain a 40 wt% solid mixture in the form of a viscous orange gel. An additional DMSO (20 mL) was added and the oil bath temperature was lowered to 200 °C. A sample taken after 18 minutes showed a molecular weight of 4,657 g / mol. After reheating for three hours, the mixture became a dark orange solution and the molecular weight decreased to 3,616 g / mol.

[0137] Comparative Example 26

[0138] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3'-BPoDA (20.8 g, 43.6 mmol), PA (0.691 g, 4.67 mmol), m-PD (2.70 g, 25.0 mmol), 4,4'-DDS (5.08 g, 20.5 mmol), and formamide (55.7 mL) were added. The flask was placed in an oil bath at 25 °C and the oil bath was heated to 170 °C with stirring at 150 to 200 rpm.

[0139] After 30 minutes, the oil bath temperature reached 169 °C and a homogeneous orange-yellow solution was observed. After 5 minutes, the mixture became cloudy with a white precipitate. Ammonia and water were noted to distill at the top. After a total of two hours, a fine light yellow slurry was observed and GPC analysis showed decomposition products.

[0140] A variety of non-halogenated solvents were also tested to evaluate their performance for the condensation polymers of BPoDA with various diamines (e.g., m-PD and 4,4'-DDS) and using phthalic anhydride as a chain terminator. The results are summarized in Table 3. In most cases, all reagents were added at the start of the polymerization. Example 12 was carried out to determine the effect of adding the phthalic anhydride chain terminator at a later stage of the polymerization.

[0141] Table 3

[0142]

[0143]

[0144] * Indicates a comparative example

[0145] The results show that benzonitrile, 3-nitrotoluene, m-cresol, p-cresol, sulfolane, NMP, and DMZ solvents provide homogeneous polymerization and the construction of high molecular weight poly(etherimide). In contrast, DMA also provides homogeneous polymerization, but the constructed molecular weight is slightly reduced. Ethyl benzoate, diphenyl ether, phenyl ethyl ether, and triglyme solvents do yield high molecular weight poly(etherimide), but they are biphasic mixtures, similar to the results from the control polymerization using o-DCB as the solvent. DMSO and formamide solvents result in decomposition products. Examples 11 to 24 provide poly(etherimides) having a Tg greater than 253 °C. Unexpectedly, the delayed addition (2 hours) of the chain terminator (Example 12) results in a significant increase in the Tg (280.6 °C) of the chain terminator relative to the earlier addition (Example 11).

[0146] Examples 11 to 24 were devolatilized at 380 to 385 °C for 20 minutes to complete the end groups. Table 4 shows that all poly(etherimide) samples have less than 25 ppm of sodium and potassium as determined by ICP digestion analysis. Similarly, all poly(etherimide) samples have less than 27 ppm of sulfate and chloride as determined by IC extract analysis.

[0147] Table 4

[0148] Example Solvent Sodium (ppm) Potassium (ppm) Sulfate (ppm) Chloride (ppm) 11 Benzonitrile 14 14 10.7 3 12 Benzonitrile 5.1 7.1 6.5 7.6 13 3-Nitrotoluene 8 6 8.8 <0.5 14 p-Cresol 17 10 16 <0.5 15 m-Cresol 20 13 7.6 2.8 16 Sulfolane ND ND 13.7 2.9 17 NMP 24 19 22.2 26.4 18 DMZ 18 13 12.6 4.9 19 DMA 10 7 7.7 6.1 20 Ethyl benzoate 16 10 6.2 1.7 21 Diphenyl ether 15 13 3.1 1.9 22 Phenetole 16 12 7.7 1.2 23 Triglyme 17 31 3.4 0.7 <![CDATA[24 * > o-DCB 16 11 4.6 1.4

[0149] * Indicates comparative examples

[0150] Examples 27 and 30 used 3,3’-BPoDA having the following profiles: ICP-Dig: sodium (20 ppm), potassium (7 ppm), zinc (0 ppm), calcium (2.6 ppm), aluminum (0 ppm), iron (3 ppm), titanium (0 ppm), phosphorus (8 ppm); IC extract: sulfate (1.2 ppm), chloride (<0.5 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); UPLC: 3,3’-BPoDA (94.20%), BPoAnhDA (4.91%).

[0151] Examples 28 and 29 used 3,3’-BPoDA with the following curves: ICP-Dig: sodium (5 ppm), potassium (41 ppm), zinc (2 ppm), calcium (4 ppm), aluminum (3 ppm), iron (9 ppm), titanium (0 ppm), phosphorus (10 ppm); IC extract: sulfate (4.6 ppm), chloride (<0.5 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); UPLC: 3,3’-BPoDA (96.26%), BPoAnhDA (3.74%).

[0152] Example 27

[0153] In a 250 mL three-neck round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (29.26 g, 61.16 mmol), PA (1.08 g, 7.30 mmol), p-PD (6.98 g, 64.5 mmol), and benzonitrile (137 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 180 °C with stirring at 150 rpm.

[0154] After 2 hours, the mixture became a fine slurry, and 56.4 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids. The nitrogen purge was reduced to 0.5 scfh and heating was continued overnight. After a total of 22.5 hours, the slurry was poured into a jar and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. GPC: weight average Mw = 14,292 g / mol; Mn = 2,763 g / mol; PDI = 5.17; Mz / Mw = 18.03; ICP-Dig: sodium (10.4), potassium (<5 ppm), zinc (<1 ppm), calcium (5.0 ppm), aluminum (1.3 ppm), iron (2.7 ppm), titanium (<1 ppm), phosphorus (<10 ppm); IC extract: sulfate (11.3 ppm), chloride (6.6 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0155] Example 28

[0156] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, a condenser, a mechanical stirrer, and a nitrogen inlet (2 scfh), 3,3'-BPoDA (29.27 g, 61.18 mmol), PA (1.08 g, 7.30 mmol), p-PD (6.98 g, 64.6 mmol), and m-cresol (133 mL) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0157] After 17 minutes, the oil bath temperature reached 103 °C, and the gel ball stage was observed. After an additional 5 minutes, the stirring was increased to 300 rpm. After a total of 40 minutes, the oil bath temperature reached 172 °C, and a homogeneous clear orange solution was obtained. After a total of 1 hour, a thick yellow slurry was observed, then additional m-cresol (50 mL) was added and the solid was broken up with a metal spatula. After an additional 90 minutes, the yellow slurry was transferred to a 500 mL three-necked round-bottom flask equipped with a Dean-Stark separator, a condenser, a mechanical stirrer, and a nitrogen inlet. The transfer was completed with additional m-cresol (150 mL). The yellow slurry of 9 wt.% solids was continued to be heated in a 200 °C oil bath. After a total heating time of 6 hours, the stirring of the viscous slurry was increased to 520 rpm. After an additional 90 minutes, the mixture was filtered through a medium-fritted glass funnel to collect the polymer solid. The sample was devolatilized under nitrogen at 380 to 385 °C (using a heating block) for 20 minutes. GPC: weight-average Mw = 10,722 g / mol; Mn = 4,813 g / mol; PDI = 2.23; Mz / Mw = 1.59.

[0158] Example 29

[0159] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, a condenser, a mechanical stirrer, and a nitrogen inlet (2 scfh), 3,3'-BPoDA (20.81 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), p-PD (3.69 g, 34.1 mmol), 4,4'-ODA (2.28 g, 11.4 mmol), and benzonitrile (102 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 120 rpm.

[0160] After 12 minutes, the oil bath temperature reached 111 °C and a suspension was observed. After an additional 13 minutes, a rubber ball stage was observed between 148 and 152 °C (oil bath temperature). The mixture became a homogeneous orange solution and then the stirring was increased to 200 rpm. After heating for a total of 1 hour 50 minutes, the target oil bath temperature of 200 °C was reached and the mixture became an opaque yellow slurry. At this point, 46 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours 35 minutes, the yellow slurry was poured into a foil dish and cooled to ambient temperature. The sample was devolatilized under nitrogen at 380 - 385 °C (hot block) for 20 minutes. GPC: weight average Mw = 24,030 g / mol; Mn = 9,873 g / mol; PDI = 2.43; Mz / Mw = 1.54. ICP-Dig: sodium (11 ppm), potassium (7 ppm), zinc (17 ppm), calcium (12 ppm), aluminum (2 ppm), iron (7 ppm), titanium (0 ppm), phosphorus (8 ppm); IC extract: sulfate (4.1 ppm), chloride (<0.5 ppm), phosphate (<0.5 ppm), nitrate (2.6 ppm), nitrite (<0.5 ppm). DSC (Tg) = 280.7 °C.

[0161] Example 30

[0162] In a 250 mL three-neck round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (60.02 g, 125.5 mmol), PA (2.30 g, 15.5 mmol), p-PD (10.92 g, 101.0 mmol), 4,4’-ODA (6.66 g, 33.3 mmol), and m-cresol (214.6 g) were added. The flask was placed in an oil bath at 25 °C and the oil bath was heated to 180 °C with stirring at 120 rpm.

[0163] After 45 minutes, the oil bath temperature reached 112 °C and the reaction mixture solidified. Additional m-cresol (70 g) was added. After an additional 25 minutes, the target oil bath temperature of 180 °C was reached and the mixture was observed to be a homogeneous gel. Additional m-cresol (60 g) was added and the oil bath temperature was adjusted to 210 °C. After heating for an additional 1 hour, 80 g of distillate was removed from the separator and then the nitrogen purge was reduced to 0.5 scfh. After a total of 7 hours 30 minutes, the homogeneous gel was poured and scraped with a metal spatula into a foil dish and cooled to ambient temperature. The sample was devolatilized at 380 to 385 °C (using a hot block) under nitrogen for 20 minutes. GPC: weight average Mw = 23,792 g / mol; Mn = 10,253 g / mol; PDI = 2.32; Mz / Mw = 1.65; ICP-Dig: sodium (10.2 ppm), potassium (9.6 ppm), zinc (3.2 ppm), calcium (13.1 ppm), aluminum (1.3 ppm), iron (10.1 ppm), titanium (1.5 ppm), phosphorus (11.5 ppm); IC extract: sulfate (2.4 ppm), chloride (0.9 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); DSC (Tg) = 275.4 °C.

[0164] Four examples were conducted to show that the poly(etherimide) polymerization carried out in the preferred solvents (benzonitrile and m-cresol) did not all remain homogeneous (Table 5). Under similar polymerization conditions, certain rigid poly(etherimides) would become insoluble, resulting in a biphasic polymerization mixture. Different from the polymerization of 3,3'-BPoDA with m-PD and 4,4'-DDS that remained homogeneous, the poly(etherimides) formed from 3,3'-BPoDA and p-PD (Examples 27 and 28) became insoluble in benzonitrile and m-cresol. In addition, when benzonitrile was used, the polymerization of 3,3'-BPoDA with p-PD and 4,4'-ODA (Example 29) also resulted in a biphasic mixture, but remained homogeneous in m-cresol (Example 30). This highlights the non-obviousness of using these and similar solvents to prepare poly(etherimides) (the aim is to maintain a homogeneous polymer solution, which can then be directly devolatilized with an extruder).

[0165] Table 5

[0166]

[0167] In the following Examples 31 and 32, 3,3’-BPoDA having the following curves was used: ICP-Dig: sodium (5 ppm), potassium (41 ppm), zinc (2 ppm), calcium (4 ppm), aluminum (3 ppm), iron (9 ppm), titanium (0 ppm), phosphorus (10 ppm); IC extract: sulfate (4.6 ppm), chloride (<0.5 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); UPLC: 3,3’-BPoDA (96.26%), BPoAnhDA (3.74%).

[0168] Example 31

[0169] Into a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (20.806 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.704 g, 25.00 mmol), 4,4’-DDS (5.079 g, 20.45 mmol), benzonitrile (92 g), and toluene (18.2 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 200 rpm.

[0170] After 37 minutes, the oil bath temperature reached 145 °C, and a homogeneous yellow solution was observed. After a total of 1 hour and 40 minutes, the distillate (46 g) was discharged from the separator to demonstrate that the reaction mixture was 30 wt% solids. The nitrogen purge was reduced to 0.5 scfh, and after an additional six hours, the sample was devolatilized under nitrogen at 380 to 385 °C (using a hot block) for 20 minutes. GPC: weight-average Mw = 27,238 g / mol; Mn = 12,829 g / mol; PDI = 2.12; Mz / Mw = 1.38. ICP-Dig: sodium (8.5 ppm), potassium (<5.0 ppm), zinc (14.6 ppm), calcium (9.9 ppm), aluminum (3.0 ppm), iron (7.3 ppm), titanium (<1.0 ppm), phosphorus (<10 ppm); IC extract: sulfate (18.1 ppm), chloride (16.8 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); DSC (Tg) = 272.7 °C.

[0171] Example 32

[0172] In a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (20.806 g, 43.49 mmol), PA (0.726 g, 4.90 mmol), m-PD (2.704 g, 25.00 mmol), 4,4’-DDS (5.079 g, 20.46 mmol), m-cresol (91 g), and toluene (18.2 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 150 to 200 rpm.

[0173] After 10 minutes, the oil bath temperature reached 114 °C, and a homogeneous yellow-orange solution was observed. At this time, the stirring was increased to 250 rpm. After a total of 55 minutes, 48 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids. The nitrogen purge was reduced to 0.5 scfh. After a total of 7.5 hours, the solution turned yellow. A sample was taken and devolatilized under nitrogen (using a hot block) at 380 to 385 °C for 20 minutes. GPC: weight-average Mw = 17,625 g / mol; Mn = 6,987 g / mol; PDI = 2.52; Mz / Mw = 1.48. DSC (Tg) = 258.3 °C.

[0174] The remaining polymer solution was heated overnight. After a total of 24 hours, the sample was devolatilized under nitrogen (using a hot block) at 380 to 385 °C for 20 minutes. GPC: weight-average Mw = 13,671 g / mol; Mn = 5,033; PDI = 2.72; Mz / Mw = 1.56. ICP-Dig: sodium (14.8 ppm), potassium (7.1 ppm), zinc (1.7 ppm), calcium (9.6 ppm), aluminum (9.6 ppm), iron (7.8 ppm), titanium (<0.5 ppm), phosphorus (7.9 ppm); IC extract: sulfate (14.4 ppm), chloride (11.7 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); DSC (Tg) = 252.3 °C.

[0175] Two examples were carried out using a dual solvent system to prepare poly(etherimide) from 3,3’-BPoDA, m-PD, and 4,4’-DDS (Table 6). In these examples, the lower boiling point solvent toluene was used together with benzonitrile (Example 31) and m-cresol (Example 32) to help remove water from the system as the polycondensation proceeded. As with the examples without toluene additive (Examples 11 and 15), the resulting poly(etherimide) polymers obtained high Tg values (>250 °C).

[0176] Table 6

[0177] Example Solvent mol% PA Mw PDI Tg (°C) 31 Benzonitrile / Toluene (5:1, m / m) 5.25％ 27,238 2.12 272.7 32 m-Cresol / Toluene (5:1, m / m) 5.25％ 17,625 2.52 258.3 11 Benzonitrile 5.25％ 29,269 2.16 275.8 15 m-Cresol 5.25％ 23,712 2.32 266.0

[0178] Comparative Example 33

[0179] In the following example, 3,3’-BPoTA with the following curves was used: ICP-Dig: sodium (138 ppm), potassium (9 ppm), zinc (2 ppm), calcium (6 ppm), aluminum (2 ppm), iron (20 ppm), titanium (0 ppm), phosphorus (7 ppm), chromium (10 ppm), magnesium (19 ppm), nickel (2 ppm); IC extract: sulfate (301 ppm), chloride (919 ppm), phosphate (<20 ppm); UPLC: 3,3’-BPoTA and isomers (98.50%).

[0180] In a 1000 mL three-neck round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoTA (64.48 g, 125.42 mmol), PA (1.991 g, 13.44 mmol), m-PD (7.812 g, 72.24 mmol), 4,4’-DDS (14.791 g, 59.57 mmol), and benzonitrile (235 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 170 to 200 rpm.

[0181] After approximately 35 minutes, the oil bath temperature reached 200 °C, and a homogeneous light amber solution was observed. At this time, the stirring was increased to 225 to 250 rpm. After a total of 65 minutes, 51 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids. The nitrogen purge was reduced to 0.5 scfh. After a total of 14 hours, the solution remained light amber. A sample was taken and devolatilized under nitrogen (using a hot block) at 380 to 385 °C for 20 minutes. GPC: weight-average Mw = 8,075 g / mol; Mn = 3,379 g / mol; PDI = 2.31; Mz / Mw = 1.54, DSC (Tg) = 178.6 °C. ICP-Dig: sodium (116 ppm), potassium (10.9 ppm), zinc (2.2 ppm), calcium (6.1 ppm), aluminum (3.8 ppm), iron (11.4 ppm), titanium (<1.0 ppm), phosphorus (<10 ppm); IC extract: sulfate (73.3 ppm), chloride (3.5 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0182] Comparative Example 34

[0183] The following examples use 3,3’-BPoTA with the following curves: ICP-Dig: sodium (52 ppm), potassium (10 ppm), zinc (1 ppm), calcium (1.3 ppm), aluminum (1.6 ppm), iron (0 ppm), titanium (0 ppm), phosphorus (8 ppm); IC-total: sulfate (1031 ppm), chloride (579 ppm), fluoride (<20 ppm), bromide (<20 ppm), phosphate (<20 ppm), nitrate (224 ppm), nitrite (117 ppm); UPLC: 3,3’-BPoTA and isomers (95.47%), 4,4’-biphenol (4.53%).

[0184] In a 1000 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), 3,3’-BPoDA (64.51 g, 125.42 mmol), PA (1.993 g, 13.44 mmol), m-PD (7.814 g, 72.24 mmol), 4,4’-DDS (14.798 g, 59.57 mmol), and benzonitrile (235 g) were added. The flask was placed in an oil bath at 25 °C, and the oil bath was heated to 200 °C with stirring at 170 to 200 rpm.

[0185] After approximately 40 minutes, the oil bath temperature reached 200 °C, and a homogeneous dark amber solution was observed. At this time, the stirring was increased to 225 to 250 rpm. After a total of 50 minutes, 49 g of distillate was removed from the separator to provide a reaction mixture with 30 wt% solids. The nitrogen purge was reduced to 0.5 scfh. After a total of 16 hours, the solution remained dark amber. A sample was taken and devolatilized for 20 minutes at 380 to 385 °C under nitrogen (using a heating block). GPC: weight-average Mw = 25,851 g / mol; Mn = 11,214 g / mol; PDI = 2.30; Mz / Mw = 1.42, DSC (Tg) = 200.9 °C. ICP-Dig: sodium (85.9 ppm), potassium (10.2 ppm), zinc (2.9 ppm), calcium (16.5 ppm), aluminum (6.7 ppm), iron (12.7 ppm), titanium (<1 ppm), phosphorus (<10 ppm); IC extract: sulfate (5.5 ppm), chloride (<0.5 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0186] Comparative Example 35

[0187] The following examples use 3,3’-BPoDA with the following profiles: ICP-Dig: sodium (7 ppm), potassium (22 ppm), zinc (2 ppm), calcium (6 ppm), aluminum (4 ppm), iron (15 ppm), titanium (1 ppm), phosphorus (11 ppm); IC extract: sulfate (8.2 ppm), chloride (<0.5 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm); UPLC: 3,3’-BPoDA (91.75%), BPoAnhDA (6.78%).

[0188] This example also uses m-PD with the following profiles: ICP-Dig: sodium (485 ppm), potassium (13 ppm), zinc (1 ppm), calcium (11 ppm), aluminum (0 ppm), iron (0 ppm), titanium (0 ppm), phosphorus (8 ppm); IC extract: sulfate (<0.5 ppm), chloride (153.8 ppm), phosphate (<0.5 ppm), nitrate (<0.5 ppm), nitrite (<0.5 ppm).

[0189] Into a 250 mL three-necked round-bottom flask equipped with a Dean-Stark separator, condenser, mechanical stirrer, and nitrogen inlet (2 scfh), add 3,3’-BPoDA (20.59 g, 43.0 mmol), PA (0.762 g, 5.14 mmol), m-PD (2.70 g, 25.0 mmol), 4,4’-DDS (5.08 g, 100 mass%, 20.5 mmol), and benzonitrile (63 mL). Place the flask in an oil bath at 25 °C and start heating the oil bath to 205 °C with stirring at 150 to 200 rpm.

[0190] After 20 minutes, the oil bath temperature reached 176 °C and a homogeneous orange-yellow solution was observed. After a total of 65 minutes, the target temperature was reached and 22.5 g of distillate was removed from the separator to obtain a 40 wt% solid solution. The nitrogen purge was reduced to 0.5 scfh and after 23 hours at 200 to 205 °C, the polymer solution was poured into a foil dish and then cooled to ambient temperature. The sample was devolatilized at 380 °C under nitrogen (using a hot block) for 20 minutes. GPC: weight average Mw = 29,037 g / mol; Mn = 12,818 g / mol; PDI = 2.27; Mz / Mw = 1.50. ICP-Dig: sodium (171 ppm), potassium (9 ppm), zinc (34 ppm), calcium (12 ppm), aluminum (3 ppm), iron (4 ppm), titanium (0 ppm), phosphorus (57 ppm); IC extract: sulfate (63.5 ppm), chloride (12.2 ppm), phosphate (5.4 ppm), nitrate (2.5 ppm), nitrite (3.5 ppm); DSC (Tg): 275.8 °C.

[0191] Table 7 shows some comparative examples of poly(etherimide) formed by the polycondensation of 3,3'-BPoDA with m-PD and 4,4'-DDS in the presence of phthalic anhydride as a chain terminator. The 3,3'-BPoTA used in Example 33 had a high level of metals and anions, which produced a poly(etherimide) with low molecular weight, low Tg (178.6 °C) and high sodium content. Examples 34 and 35 relate to the cyclization of 3,3'-BPoTA to 3,3'-BPoDA, which was then reacted with diamine (in situ) in benzonitrile to obtain the resulting poly(etherimide). The 3,3'-BPoTA used in Example 34 also had a high level of sodium and an elevated level of 4,4'-biphenol (organic contaminant) bound to the anion. This material produced a poly(etherimide) with higher molecular weight but with low Tg (200.9 °C) and high sodium content. Example 35 used a diamine precursor with a high sodium content. This produced a poly(etherimide) with high molecular weight, high Tg (275.8 °C) and high sodium content (171 ppm). All comparative Examples 33 to 35 showed elevated levels of inorganic contaminants and the polymer films obtained after hot pressing at 380 to 385 °C were brittle and darker in color. This would have an adverse effect on the transparency and thermal stability required for the end-use applications. Further, the results showed that the properties of the resulting polymers were not comparable to those of the polymers obtained by the process used in the examples of the present invention.

[0192] Table 7

[0193]

[0194]

[0195] * Represent comparative examples

[0196] The transmissivity of films prepared from several poly(etherimide) examples of the present invention and comparative poly(etherimides) is shown in Table 8 below. Using a melt temperature of 380 to 400 °C and a mold temperature of 150 to 200 °C, these examples were injection molded into optical sheets having dimensions of 50 mm x 75 mm x 1 mm. The term "percent light transmission" or "%T" refers to the ratio of transmitted light to incident light and can be measured according to ASTM D 1003-07. These measurements can be made on molded articles between 0.1 mm and 0.3 mm thick films that can be prepared on a hot press at 380 to 400 °C. Polymer film Examples 11, 15, 16, and 18 were prepared from non-halogenated solvents and contain 20 ppm or less of sodium. At both visible light (630 nm) and infrared light (850 nm, 1310 nm, 1550 nm) wavelengths, each has transmissivity similar to or better than that of the film prepared with oil o-DCB (Example 24). In contrast, Example 35 is a poly(etherimide) film prepared from benzonitrile and contains a high content of sodium (171 ppm). This example has significantly reduced transmissivity at all wavelengths tested.

[0197] Table 8

[0198]

[0199] * Represent comparative examples

[0200] Comparative Example 36

[0201] To a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, Dean-Stark separator, and condenser, 3,3'-BPoTA (15 g, 29.2 mmol) and cyclohexanone (58.5 mL) were added to prepare a 20 wt% mixture. The flask was then placed in an oil bath at 160 °C under nitrogen. Fresh cyclohexanone was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. Samples were taken from the heterogeneous yellow solution every hour to monitor the progress of the reaction by UPLC analysis. Sometimes, solids were scraped from the stirrer blades and shaft with a metal spatula. After 8 hours, UPLC analysis indicated that the reaction was substantially complete. The mixture was then cooled to 50 °C to form a light grayish-white precipitate in cyclohexanone. The product was collected by filtration on a medium sintered glass funnel and then washed with methanol (125 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, 10.57 g of 3,3'-BPoDA product was collected.

[0202] Example 37

[0203] 3,3'-BPoTA (15 g, 29.2 mmol) and m-cresol (53.7 mL) were added to a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser to prepare a 20 wt% mixture. The flask was then placed in an oil bath at 160 °C under nitrogen. Fresh m-cresol was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. Samples were taken from the homogeneous yellow solution every hour to monitor the progress of the reaction by UPLC analysis. After 3 hours, UPLC analysis indicated that the reaction was complete. The mixture was then cooled to 50 °C to form a light grayish-white precipitate in m-cresol. The product was collected by filtration on a medium sintered glass funnel and then washed with methanol (125 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, 13.09 g of 3,3'-BPoDA product was collected.

[0204] Example 38

[0205] 3,3'-BPoTA (15 g, 29.2 mmol) and m-cresol (53.7 mL) were added to a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser to prepare a 20 wt% mixture. The flask was then placed in an oil bath at 210 °C under nitrogen. Fresh m-cresol was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. Samples were taken from the homogeneous yellow solution every half hour to monitor the progress of the reaction by UPLC analysis. After 0.5 to 1 hour, UPLC analysis indicated that the reaction was complete. The mixture was then cooled to 50 °C to form a light grayish-white precipitate in m-cresol. The product was collected by filtration on a fine sintered glass funnel and then washed with methanol (50 °C, 3 × 20 mL), and then washed with DI water (60 to 70 °C, 2 × 20 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, the 3,3'-BPoDA product as a white solid was collected.

[0206] Example 39

[0207] 3,3’-BPoTA (15 g, 29.2 mmol) and sulfolane (44 mL) were added to a 250 mL three-necked round-bottom flask equipped with a mechanical stirrer, a Dean-Stark separator, and a condenser to prepare a 20 wt% mixture. The flask was then placed in an oil bath at 220 °C under nitrogen. Fresh sulfolane was added to the reaction flask to replenish the solvent loss in the Dean-Stark separator. Samples were taken from the homogeneous yellow solution every half hour to monitor the progress of the reaction by UPLC analysis. After 0.5 to 1 hour, UPLC analysis indicated that the reaction was complete. The mixture was then cooled to 50 °C to form a light grayish-white precipitate in sulfolane. The product was collected by filtration on a medium sintered glass funnel and then washed with methanol (125 mL). The product was dried in a vacuum oven at 140 to 145 °C until a constant mass was obtained. In this way, 15.06 g of 3,3’-BPoDA product as a white solid was collected.

[0208] Table 9 below shows the comparison of the ring closures of cyclohexanone, m-cresol, and sulfolane at various temperatures. Comparative Example 36 required 8 hours to complete at 160 °C (oil bath temperature, solvent boiling point = 155.65 °C) and remained heterogeneous throughout the reaction. Examples 37 and 38 show that m-cresol is superior to cyclohexanone as the cycle time was reduced to three hours (at 160 °C) and 0.5 to 1 hour (at 210 °C). Since m-cresol is a polar aprotic solvent with a higher boiling point (202.8 °C) than cyclohexanone, the reaction remained homogeneous. In a similar manner, Example 39 required only 0.5 to 1 hour at 220 °C in sulfolane to complete (oil bath temperature, solvent boiling point = 285 °C). Additionally, both m-cresol and sulfolane provided higher conversions (96.4% to 96.9%) compared to cyclohexanone (93.0%) as fewer impurities were observed in their reaction mixtures.

[0209] Table 9

[0210] Example Solvent Temperature (°C) Cycle time (hours) Observation % Product <![CDATA[36 * > Cyclohexanone 160 8 Heterogeneous 93.0％ 37 m-Cresol 160 3 Homogeneous 96.4％ 38 m-Cresol 210 0.5-1 Homogeneous 96.8％ 39 Sulfolane 220 0.5-1 Homogeneous 96.9％

[0211] * Indicates comparative examples

[0212] The present disclosure also encompasses the following aspects.

[0213] Aspect 1: A method for preparing a biphenol dianhydride composition, the method comprising: heating a first solution under conditions effective to provide a second solution, the first solution comprising: a biphenol tetraacid of the following formula

[0214]

[0215] wherein, R a and R bEach independently is a halogen or a monovalent C 1-6 alkyl group, and p and q are each independently an integer from 0 to 4, preferably, wherein p and q are each 0; at least one ionic substance, the ionic substance including sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, titanium ions, phosphorus ions, iron ions, phosphate ions, sulfate ions, chloride ions, nitrate ions, nitrite ions, and sulfite ions; and a non-halogenated solvent, the non-halogenated solvent including ethyl benzoate, diphenyl ether, phenyl ethyl ether, triglyme, benzonitrile, sulfolane, m-cresol, o-cresol, p-cresol, 1-nitrotoluene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethylacetamide, or a combination thereof; the second solution includes: the corresponding biphenol dianhydride; at least one of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, titanium ions, phosphorus ions, iron ions, phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions; and a solvent.

[0216] Aspect 2: The method according to aspect 1, further comprising cooling the second solution to a temperature effective for precipitating the biphenol dianhydride; separating the biphenol dianhydride from the second solution; and optionally washing the separated biphenol dianhydride with an organic solvent, water, or a combination thereof.

[0217] Aspect 3: The method as described in aspect 2, the method further comprising filtering the second solution to remove ionic substances before cooling the second solution or filtering the second solution to remove ionic substances before polymerization.

[0218] Aspect 4: A method for purifying biphenol dianhydride, the method comprising: removing ionic substances from a solution comprising biphenol dianhydride and a non-halogenated solvent, the non-halogenated solvent including ethyl benzoate, diphenyl ether, phenyl ethyl ether, triglyme, benzonitrile, sulfolane, m-cresol, o-cresol, p-cresol, 1-nitrotoluene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethylacetamide, or a combination thereof, the method comprising: adsorbing ionic substances from the solution by an adsorbent comprising Celite diatomaceous earth, diatomaceous earth, silica, alumina, or a combination thereof; crystallizing the biphenol dianhydride from the solution; filtering the solution to remove ionic substances; or a combination thereof.

[0219] Aspect 5: The method according to any one of aspects 1 to 4, wherein the biphenol dianhydride is a mixture of isomers, preferably, wherein 10 wt% to 100 wt% of the biphenol dianhydride has a double bond of the biphenol group of the biphenol dianhydride at the 3,3' position, more preferably, wherein 90 wt% to 100 wt% of the biphenol dianhydride has a double bond of the biphenol group of the biphenol dianhydride at the 3,3' position.

[0220] Aspect 6: The method according to any one of Aspects 1 to 5, wherein the purified biphenol dianhydride contains sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, titanium ions, phosphorus ions, and iron ions each less than 25 ppm; sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, titanium ions, phosphorus ions, and iron ions in total less than 110 ppm; phosphate ions, sulfate ions, sulfite ions, chloride ions, nitrate ions, and nitrite ions each less than 20 ppm, and preferably, NaHSO3, Na2SO4, KHSO3, K2SO4, NaNO3, NaNO2, KNO3, KNO2, NaCl, KCl, CaSO4, Ca(NO3)2 each less than 45 ppm; and phosphate ions, sulfate ions, chloride ions, nitrate ions, and nitrite ions in total less than 50 ppm.

[0221] Aspect 7: A biphenol dianhydride prepared by the method according to any one or more of Aspects 1 to 6.

[0222] Aspect 8: A poly(etherimide) derived from the biphenol dianhydride according to Aspect 7 and an organic diamine, and preferably, wherein the organic diamine is 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, 4,4'-oxydianiline, 3,3'-oxydianiline, 3,4'-oxydianiline, or a combination thereof.

[0223] Aspect 9: The poly(etherimide) according to Aspect 8, wherein the poly(etherimide) contains: sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, titanium ions, phosphorus ions, and iron ions each less than 25 ppm; and phosphate ions, sulfate ions, sulfite ions, chloride ions, nitrate ions, and nitrite ions each less than 20 ppm.

[0224] Aspect 10: A method for preparing the poly(etherimide) according to any one of Aspects 8 to 9, the method comprising: contacting the biphenol dianhydride with an organic diamine in the presence of an aromatic non-halogenated solvent under conditions effective to provide the poly(etherimide).

[0225] Aspect 11: The method according to Aspect 10, wherein the aromatic non-halogenated solvent includes benzonitrile, 1-nitrotoluene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, m-cresol, o-cresol, p-cresol, N-methylpyrrolidone, sulfolane, triethylene glycol dimethyl ether, phenetole, ethyl benzoate, dimethylacetamide, diphenyl ether, and 1,3-dimethyl-2-imidazolidinone, or a combination thereof.

[0226] Aspect 12: The method according to aspect 10 or 11, further comprising devolatilizing the poly(etherimide).

[0227] Aspect 13: An article comprising the poly(etherimide) according to any one of aspects 8 to 9.

[0228] Aspect 14: The poly(etherimide) according to any one of aspects 8 to 9, wherein an article molded from the poly(etherimide) or a pressed film comprising the poly(etherimide) has a percent transmittance of 65% measured at 630 nm, 850 nm, 1310 nm, and 1550 nm at a thickness of 0.16 mm according to ASTM D 1003-07.

[0229] Aspect 15: The article according to aspect 14, wherein the article is an optical component, preferably a lens.

[0230] The compositions, methods, and articles may alternatively comprise, consist of, or consist essentially of any suitable materials, steps, or components disclosed herein. The compositions, methods, and articles may additionally or alternatively be formulated to be free or substantially free of any materials (or substances), steps, or components that are unnecessary for achieving the functions or objectives of these compositions, methods, and articles.

[0231] All ranges disclosed herein include the endpoints, and the endpoints can be combined with each other independently. "Combination" includes blends, mixtures, alloys, reaction products, etc. The terms "first", "second", etc. do not denote any order, quantity, or importance, but are used to distinguish one element from another. The terms "a", "an", and "the" do not denote a limitation of quantity and are understood to include both the singular and the plural, unless otherwise indicated herein or the context clearly dictates the contrary. Unless otherwise explicitly stated, "or" means "and / or". Throughout the specification, references to "some embodiments", "embodiments", etc. mean that the specific elements described in connection with the embodiments are included in at least one embodiment herein and may or may not be present in other embodiments. As used herein, the term "combinations thereof" includes one or more of the listed elements and is open-ended, allowing for the presence of one or more additional, unlisted elements of a similar nature. In addition, it should be understood that the described elements can be combined in any suitable manner in various embodiments.

[0232] Unless otherwise stated to the contrary herein, all test standards are the latest standards effective as of the filing date of the present application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0233] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. All patents, patent applications, and other references cited are incorporated herein by reference in their entirety. However, if a term in this application contradicts or conflicts with a term in the incorporated references, the term from this application prevails over the conflicting term from the incorporated references.

[0234] Compounds are described using standard nomenclature. For example, any position not substituted with any indicated group should be understood to have its valency filled with a bond or hydrogen atom as indicated. A hyphen (“-”) not between two letters or symbols is used to indicate the point of attachment of a substituent. For example, -CHO is attached through the carbon of the carbonyl group.

[0235] As used herein, the term “hydrocarbyl,” whether used alone or as a prefix, suffix, or fragment of another term, refers to a residue containing only carbon and hydrogen. The residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight-chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. However, when a hydrocarbyl residue is described as substituted, it can optionally contain heteroatoms on and above the carbon and hydrogen members of the substituent residue. Thus, when specifically described as substituted, a hydrocarbyl residue can also contain one or more carbonyl, amino, hydroxy, etc., or it can contain heteroatoms within the backbone of the hydrocarbyl residue. The term “alkyl” refers to a branched or straight-chain, unsubstituted aliphatic hydrocarbyl group, e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl, and n-hexyl and sec-hexyl. “Alkenyl” refers to a straight-chain or branched monovalent hydrocarbyl group having at least one carbon-carbon double bond (e.g., vinyl (-HC═CH2)). “Alkoxy” refers to an alkyl group attached through oxygen (i.e., alkyl-O-), e.g., methoxy, ethoxy, and sec-butoxy groups. “Alkylene” refers to a straight-chain or branched, saturated divalent aliphatic hydrocarbyl group (e.g., methylene (-CH2-) or propylene (-(CH2)3-)). “Cycloalkylene” refers to a divalent cyclic alkylene group, -C n H 2n-x, wherein x is the number of hydrogens replaced by cyclization. "Cycloalkenyl" means a monovalent group having one or more rings and one or more carbon-carbon double bonds in the ring, wherein all ring members are carbon (e.g., cyclopentyl and cyclohexyl). "Aryl" means an aromatic hydrocarbon group containing a specified number of carbon atoms, such as phenyl, tropone, indanyl, or naphthyl. "Arylene" means a divalent aryl. "Alkylarylene" means an arylene substituted by an alkyl. "Arylalkylene" means an alkylene substituted by an aryl (e.g., benzyl). The prefix "halo" means a group or compound containing one or more fluoro, chloro, bromo, or iodo substituents. Combinations of different halo groups (e.g., bromo and fluoro) or only chloro groups may be present. The prefix "hetero" means a compound or group containing at least one ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatoms), wherein the heteroatoms are each independently N, O, S, Si, or P. "Substituted" means that a compound or group is substituted by at least one (e.g., 1, 2, 3, or 4) substituent, which may each independently be C 1-9 alkoxy, C 1-9 haloalkoxy, nitro (-NO2), cyano (-CN), C 1-6 alkylsulfonyl (-S(=O)2-alkyl), C 6-12 arylsulfonyl (-S(=O)2-aryl), mercapto (-SH), thiocyanato (-SCN), toluenesulfonyl (CH3C6H4SO2-), C 3-12 cycloalkyl, C 2-12 alkenyl, C 5-12 cycloalkenyl, C 6-12 aryl, C 7-13 arylalkylene, C 4-12 heterocycloalkyl, and C 3-12 heteroaryl in place of hydrogen, provided that the normal valence of the substituted atoms is not exceeded. The number of carbon atoms indicated in the group does not include any substituents. For example, -CH2CH2CN is a C2 alkyl substituted by a nitrile.

[0236] Although specific embodiments have been described, alternative, modifications, variations, improvements, and substantial equivalents that are presently unforeseen or may not have been foreseen by the applicant or other skilled artisans in the art may be contemplated. Accordingly, the appended claims, as filed and as they may be amended, are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. A method for preparing a biphenol dianhydride composition, the method comprising: heating a first solution under conditions effective to provide a second solution, the first solution comprising a biphenol tetracarboxylic acid of the following formula wherein, R a and R b are each independently halogen or a monovalent C 1-6 alkyl group, and p and q are each independently an integer from 0 to 4; at least one ionic substance selected from sodium ion, potassium ion, calcium ion, zinc ion, aluminum ion, titanium ion, phosphorus ion, iron ion, phosphate ion, sulfate ion, chloride ion, nitrate ion, nitrite ion, and sulfite ion; and a non-halogenated solvent selected from benzonitrile, sulfolane, m-cresol, o-cresol, p-cresol, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, or a combination thereof; the second solution comprising: the corresponding biphenol dianhydride; at least one of sodium ion, potassium ion, calcium ion, zinc ion, aluminum ion, titanium ion, phosphorus ion, iron ion, phosphate ion, sulfate ion, chloride ion, nitrate ion, and nitrite ion; and the solvent.

2. The method according to claim 1, further comprising cooling the second solution to a temperature effective to precipitate the biphenol dianhydride; separating the biphenol dianhydride from the second solution; and optionally washing the separated biphenol dianhydride with an organic solvent, water, or a combination thereof.

3. The method according to claim 2, further comprising filtering the second solution to remove ionic substances before cooling the second solution or filtering the second solution to remove ionic substances before polymerization.

4. A method for purifying a biphenol dianhydride, the method comprising: removing ionic substances from a solution comprising a biphenol dianhydride and a non-halogenated solvent, the non-halogenated solvent including benzonitrile, sulfolane, m-cresol, o-cresol, p-cresol, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, or a combination thereof, the method comprising: adsorbing the ionic substances from the solution by an adsorbent including Celite diatomaceous earth, diatomaceous earth, silica, alumina, or a combination thereof; crystallizing the biphenol dianhydride from the solution; filtering the solution to remove the ionic substances; or a combination thereof.

5. The method according to any one of claims 1 to 4, wherein, The biphenol dianhydride is a mixture of isomers.

6. The method according to any one of claims 1 to 4, wherein The biphenol dianhydride comprises sodium ion, potassium ion, calcium ion, zinc ion, aluminum ion, titanium ion, phosphorus ion, and iron ion each less than 25 ppm; sodium ion, potassium ion, calcium ion, zinc ion, aluminum ion, titanium ion, phosphorus ion, and iron ion in total less than 110 ppm; phosphate ion, sulfate ion, sulfite ion, chloride ion, nitrate ion, and nitrite ion each less than 20 ppm; and phosphate ion, sulfate ion, chloride ion, nitrate ion, and nitrite ion in total less than 50 ppm.

7. A biphenol dianhydride prepared by the method according to any one of claims 1 to 4.

8. A poly(etherimide) derived from the biphenol dianhydride according to claim 7 and an organic diamine.

9. The poly(etherimide) according to claim 8, wherein, The poly(etherimide) comprises: sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, titanium ions, phosphorus ions, and iron ions, each less than 25 ppm; and phosphate ions, sulfate ions, sulfite ions, chloride ions, nitrate ions, and nitrite ions, each less than 20 ppm.

10. A method for preparing the poly(etherimide) of claim 8, the method comprising: contacting the biphenol dianhydride with the organic diamine in the presence of an aromatic non-halogenated solvent under conditions effective to provide the poly(etherimide).

11. The method according to claim 10, wherein, The aromatic non-halogenated solvent includes benzonitrile, m-cresol, o-cresol, p-cresol, N-methylpyrrolidone, sulfolane, or a combination thereof.

12. The method according to claim 10, further comprising devolatilizing the poly(etherimide).

13. An article comprising the poly(etherimide) of claim 8.

14. The poly(etherimide) according to claim 8, wherein, Measured at a thickness of 0.16 mm according to ASTM D 1003-07, articles molded from the poly(etherimide) or a pressed film comprising the poly(etherimide) have a percent transmittance greater than 65% at 630 nm, 850 nm, 1310 nm, and 1550 nm.

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