WO2008082417A1 - Procédé de purification de dianhydrides - Google Patents

Procédé de purification de dianhydrides Download PDF

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Publication number
WO2008082417A1
WO2008082417A1 PCT/US2007/000138 US2007000138W WO2008082417A1 WO 2008082417 A1 WO2008082417 A1 WO 2008082417A1 US 2007000138 W US2007000138 W US 2007000138W WO 2008082417 A1 WO2008082417 A1 WO 2008082417A1
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Prior art keywords
mixture
anhydride
oxybisphthalic anhydride
oxybisphthalic
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PCT/US2007/000138
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English (en)
Inventor
Albert Santo Stella
Qing Ye
David Winfield Woodruff
Paul Edward Howson
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Sabic Innovative Plastics Ip B.V.
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Priority to PCT/US2007/000138 priority Critical patent/WO2008082417A1/fr
Publication of WO2008082417A1 publication Critical patent/WO2008082417A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/54—Preparation of carboxylic acid anhydrides
    • C07C51/567—Preparation of carboxylic acid anhydrides by reactions not involving carboxylic acid anhydride groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/54—Preparation of carboxylic acid anhydrides
    • C07C51/573—Separation; Purification; Stabilisation; Use of additives

Definitions

  • This invention relates to a method for purifying a dianhydride. More particularly, the method relates to purifying an oxybisphthalic anhydride.
  • Oxybisphthalic anhydride a monomer prized as a component of a unique class of high temperature polyetherimides, may prepared from chlorophthalic anhydride by coupling two molecules of chlorophthalic anhydride in the presence of an inorganic carbonate, a solvent and a phase transfer catalyst.
  • the crude product of such a coupling reaction often includes the solvent, unreacted starting material(s), phase transfer catalyst, inorganic by-products, and other impurities, which must be separated from the oxybisphthalic anhydride prior to its use in polymer synthesis.
  • 3,338,923 discloses a method of purifying pyromellitic dianhydride by treatment with ketones. Furthermore, US Patent No. 3,338,923 discloses that the material can be purified by converting the dianhydride into the corresponding acid with water and recrystallizing the acid from water in the presence of activated carbon.
  • US Patent No. 4,906,760 discloses the removal of various metal ion impurities from aromatic anhydrides.
  • U.S. Patent No. 4,906,760 likewise discloses the removal of metal ion impurities from aromatic anhydrides.
  • US Patent No. 4,870,194 discloses a purification scheme for oxybisphthalic anhydride.
  • US Patent No. 5,145,971 likewise discloses a process for the preparation of purified oxybisphthalic acid from impure oxybisphthalic anhydride.
  • US Patent No. 5,336,788 discloses the conversion of oxybisphthalic acid to oxybisphthalic anhydride.
  • the present invention provides a method of preparing a purified oxybisphthalic anhydride, said method comprising steps (a) — (e):
  • a first mixture comprising at least one oxybisphthalic anhydride, at least one solvent, and at least one inorganic salt selected from the group consisting of alkali metal halide salts, alkaline earth metal halide salts, and mixtures thereof, said oxybisphthalic anhydride being present in said first mixture in an amount corresponding to at least 25 percent by weight of a total weight of said first mixture;
  • the present invention provides a method for the preparation of an oxybisphthalic anhydride having structure I, said method comprising steps (a)-(e)
  • X 1 is selected from the group consisting of fluoro, chloro, bromo, iodo, and nitro groups;
  • oxybisphthalic anhydride optionally crystallizing the oxybisphthalic anhydride from the homogeneous solution to provide a purified oxybisphthalic anhydride containing less than 100 ppm of alkali metal ions, alkaline earth metal ions, or mixtures thereof.
  • the present invention provides a method for preparing a polyetherimide, said method comprising:
  • step (ii) removing water from the polymerization mixture formed in step (i) to provide product polyetherimide
  • a first mixture comprising at least one oxybisphthalic anhydride, at least one solvent, and at least one inorganic salt selected from the group consisting of alkali metal halide salts, alkaline earth metal halide salts, and mixtures thereof, said oxybisphthalic anhydride being present in said first mixture in an amount corresponding to at least 25 percent by weight of a total weight of said first mixture; diluting said first mixture with at least one solvent, to provide a second mixture, wherein the oxybisphthalic anhydride is present in an amount corresponding to less than 25 percent by weight of a total weight of the second mixture;
  • the phrase “dissolving substantially all of the oxybisphthalic anhydride present” means dissolving at least 90 percent of the oxybisphthalic anhydride present.
  • aromatic radical refers to an array of atoms having a valence of at least one comprising at least one aromatic group.
  • the array of atoms having a valence of at least one comprising at least one aromatic group may include heteroatoms such as nitrogen, sulfur, selenium, silicon and oxygen, or may be composed exclusively of carbon and hydrogen.
  • aromatic radical includes but is not limited to phenyl, pyridyl, furanyl, thienyl, naphthyl, phenylene, and biphenyl radicals.
  • the aromatic radical contains at least one aromatic group.
  • the aromatic radical may also include nonaromatic components.
  • a benzyl group is an aromatic radical which comprises a phenyl ring (the aromatic group) and a methylene group (the nonaromatic component).
  • a tetrahydronaphthyl radical is an aromatic radical comprising an aromatic group (CeH 3 ) fused to a nonaromatic component -(CH 2 )4-.
  • aromatic radical is defined herein to encompass a wide range of functional groups such as alkyl groups, alkenyl groups, alkynyl groups, haloalkyl groups, haloaromatic groups, conjugated dienyl groups, alcohol groups, ether groups, aldehydes groups, ketone groups, carboxylic acid groups, acyl groups (for example carboxylic acid derivatives such as esters and amides), amine groups, nitro groups, and the like.
  • the 4-methylphenyl radical is a C 7 aromatic radical comprising a methyl group, the methyl group being a functional group which is an alkyl group.
  • the 2-nitrophenyl group is a C ⁇ aromatic radical comprising a nitro group, the nitro group being a functional group.
  • Aromatic radicals include halogenated aromatic radicals such as A- trifluoromethylphenyl, hexafluoroisopropylidenebis(4-phen-l-yloxy) (i.e., - OPhC(CF 3 ) 2 PhO-), 4-chloromethylphen-l-yl, 3-trifluorovinyl-2-thienyl, 3- trichloromethylphen-1-yl (i.e., 3-CCbPh-), 4-(3-bromoprop-l-yl)phen-l-yl (i.e., A- BrCH 2 CH 2 CH 2 Ph-), and the like.
  • aromatic radicals include A- allyloxyphen-1-oxy, 4-aminophen-l-yl (i.e., 4-H 2 NPh-), 3-aminocarbonylphen-l-yl (i.e., NH 2 COPh-), 4-benzoylphen-l-yl, dicyanomethylidenebis(4-phen-l-yloxy) (i.e., -OPhC(CN) 2 PhO-), 3-methylphen-l-yl, methylenebis(4-phen-l-yloxy) (i.e., - OPhCH 2 PhO-), 2-ethylphen-l-yl, phenylethenyl, 3-formyl-2-thienyl, 2-hexyl-5- furanyl, hexamethylene-l,6-bis(4 ⁇ phen-l-yloxy) (i.e., -OPh(CH 2 ) 6 PhO-), 4- hydroxymethylphen-1-yl (i.e
  • a C 3 — Cio aromatic radical includes aromatic radicals containing at least three but no more than 10 carbon atoms.
  • the aromatic radical 1-imidazolyl (C 3 H2N2-) represents a C 3 aromatic radical.
  • the benzyl radical (C 7 H 7 -) represents a C 7 aromatic radical.
  • cycloaliphatic radical refers to a radical having a valence of at least one, and comprising an array of atoms which is cyclic but which is not aromatic. As defined herein a “cycloaliphatic radical” does not contain an aromatic group.
  • a “cycloaliphatic radical” may comprise one or more noncyclic components.
  • a cyclohexylmethyl group (CeHnCH 2 -) is an cycloaliphatic radical which comprises a cyclohexyl ring (the array of atoms which is cyclic but which is not aromatic) and a methylene group (the noncyclic component).
  • the cycloaliphatic radical may include heteroatoms such as nitrogen, sulfur, selenium, silicon and oxygen, or may be composed exclusively of carbon and hydrogen.
  • cycloaliphatic radical is defined herein to encompass a wide range of functional groups such as alkyl groups, alkenyl groups, alkynyl groups, haloalkyl groups, conjugated dienyl groups, alcohol groups, ether groups, aldehyde groups, ketone groups, carboxylic acid groups, acyl groups (for example carboxylic acid derivatives such as esters and amides), amine groups, nitro groups, and the like.
  • the 4-methylcyclopent-l-yl radical is a C 6 cycloaliphatic radical comprising a methyl group, the methyl group being a functional group which is an alkyl group.
  • the 2-nitrocyclobut-l-yl radical is a C 4 cycloaliphatic radical comprising a nitro group, the nitro group being a functional group.
  • a cycloaliphatic radical may comprise one or more halogen atoms which may be the same or different. Halogen atoms include, for example; fluorine, chlorine, bromine, and iodine.
  • Cycloaliphatic radicals comprising one or more halogen atoms include 2-trifluoromethylcyclohex-l- yl ⁇ -bromodifluoromethylcyclooct-l-yl, 2-chlorodifluoromethylcyclohex-l-yl, hexafluoroisopropylidene-2,2-bis (cyclohex-4-yl) (i.e., -C 6 Hi 0 C(CFs) 2 CeHi 0 -), 2- chloromethylcyclohex-1-yl, 3- difluoromethylenecyclohex-1-yl, 4- trichloromethylcyclohex- 1 -yloxy, 4-bromodichloromethylcyclohex- 1 -ylthio, 2- bromoethylcyclopent-1-yl, 2-bromopropylcyclohex-l -yloxy (e.g.
  • cycloaliphatic radicals include 4-allyloxycyclohex-l-yl, 4-aminocyclohex-l-yl (i.e., H 2 NC 6 HiO-), 4- aminocarbonylcyclopent-1-yl (i.e., NH 2 COCsHs-), 4-acetyloxycyclohex-l-yl, 2,2- dicyanoisopropylidenebis(cyclohex-4-yloxy) (i.e., -OC 6 Hi O C(CNhC 6 Hi O O-), 3- methylcyclohex-1-yl, methylenebis(cyclohex-4-yloxy) (i.e., -OC 6 HIoCH 2 CeHiOO-), 1-ethylcyclobut-l-yl, cyclopropylethenyl, 3-formyl-2-terahydrofuranyl, 2-hexyl-5-
  • a C 3 — Cio cycloaliphatic radical includes cycloaliphatic radicals containing at least three but no more than 10 carbon atoms.
  • the cycloaliphatic radical 2-tetrahydrofuranyl (C 4 H 7 O-) represents a C 4 cycloaliphatic radical.
  • the cyclohexylmethyl radical (C 6 HnCH 2 -) represents .TC 7 cycloaliphatic radical.
  • aliphatic radical refers to an organic radical having a valence of at least one consisting of a linear or branched array of atoms which is not cyclic. Aliphatic radicals are defined to comprise at least one carbon atom. The array of atoms comprising the aliphatic radical may include heteroatoms such as nitrogen, sulfur, silicon, selenium and oxygen or may be composed exclusively of carbon and hydrogen.
  • aliphatic radical is defined herein to encompass, as part of the "linear or branched array of atoms which is not cyclic" a wide range of functional groups such as alkyl groups, alkenyl groups, alkynyl groups, haloalkyl groups , conjugated dienyl groups, alcohol groups, ether groups, aldehyde groups, ketone groups, carboxylic acid groups, acyl groups (for example carboxylic acid derivatives such as esters and amides), amine groups, nitro groups, and the like.
  • functional groups such as alkyl groups, alkenyl groups, alkynyl groups, haloalkyl groups , conjugated dienyl groups, alcohol groups, ether groups, aldehyde groups, ketone groups, carboxylic acid groups, acyl groups (for example carboxylic acid derivatives such as esters and amides), amine groups, nitro groups, and the like.
  • the 4-methylpent-l-yl radical is a C ⁇ aliphatic radical comprising a methyl group, the methyl group being a functional group which is an alky ⁇ group.
  • the 4-nitrobut-l-yl group is a C 4 aliphatic radical comprising a nitro group, the nitro group being a functional group.
  • An aliphatic radical may be a haloalkyl group which comprises one or more halogen atoms which may be the same or different. Halogen atoms include, for example; fluorine, chlorine, bromine, and iodine.
  • Aliphatic radicals comprising one or more halogen atoms include the alkyl halides trifluoromethyl, bromodifluoromethyl, chlorodifluoromethyl, hexafluoroisopropylidene, chloromethyl, difluorovinylidene, trichloromethyl, bromodichlorornethyl, bromoethyl, 2-bromotrimethylene (e.g. -CH 2 CHBrCH 2 -), and the like.
  • aliphatic radicals include allyl, aminocarbonyl (i.e., - CONH 2 ), carbonyl, 2,2-dicyanoisopropylidene (i.e., -CH 2 C(CN) 2 CH 2 -), methyl (i.e., - CH 3 ), methylene (i.e., -CH 2 -), ethyl, ethylene, formyl (i.e.-CHO), hexyl, hexamethylene, hydroxymethyl (i.e.-CH 2 OH), mercaptomethyl (i.e., -CH 2 SH), methylthio (i.e., -SCH 3 ), methylthiomethyl (i.e., -CH 2 SCH 3 ), methoxy, methoxycarbonyl (i.e., CH 3 OCO-) , nitromethyl (i.e., -CH2NO 2 ), thiocarbonyl, trimethylsilyl ( i.e.,
  • a Ci — Cio aliphatic radical contains at least one but no more than 10 carbon atoms.
  • a methyl group i.e., CH 3 -
  • a decyl group i.e., CH 3 (CH2) 9 -
  • a Cio aliphatic radical contains at least one but no more than 10 carbon atoms.
  • the present invention relates to a method for purifying an oxybisphthalic anhydride having structure I, said method comprising steps (a)-(e):
  • a first mixture comprising at least one oxybisphthalic anhydride, at least one solvent, and at least one inorganic salt selected from the group consisting of alkali metal halide salts, alkaline earth metal halide salts, and mixtures thereof, said oxybisphthalic anhydride being present in said first mixture in an amount corresponding to at least 25 percent by weight of a total weight of said first mixture; diluting said first mixture with at least one solvent, to provide a second mixture, wherein the oxybisphthalic anhydride is present in an amount corresponding to less than 25 percent by weight of a total weight of the second mixture;
  • the crystallized oxybisphthalic anhydride is isolated and washed with solvent, and then dried to provide oxybisphthalic anhydride containing less than 100 ppm of alkali metal ions, alkaline earth metal ions, or mixtures thereof.
  • the crystallized oxybisphthalic anhydride is isolated, resluurried in solvent, filtered and then dried to provide oxybisphthalic anhydride containing less than 100 ppm of alkali metal ions, alkaline earth metal ions, or mixtures thereof.
  • the crystallized oxybisphthalic anhydride is isolated by filtration, and then dried to provide oxybisphthalic anhydride containing less than 100 ppm of alkali metal ions, alkaline earth metal ions, or mixtures thereof.
  • the oxybisphthalic anhydrides represented by generic structure I are hereinafter sometimes referred to as "ODPA".
  • the oxybisphthalic anhydrides represented by structure I may also be referred to as "bisanhydrides".
  • the genus represented by structure I includes within it pure oxybisphthalic anhydrides such as 4,4'- oxybisphthalic anhydride; 3,3 '-oxybisphthalic anhydride; and 3,4'-oxybisphthalic anhydride.
  • the genus represented by structure I includes mixtures of oxybisphthalic anhydrides, for example a mixture of 4,4'-oxybisphthalic anhydride and 3,3'-oxybisphthalic anhydride.
  • structure I represents a bisanhydride consisting essentially of 3,3' -oxybisphthalic anhydride. In an alternate embodiment, structure I represents a bisanhydride consisting essentially of 3,4'- oxybisphthalic anhydride. In yet another embodiment, structure I represents a mixture of 3,3'-oxybisphthalic anhydride and 3,4' -oxybisphthalic anhydride.
  • minor amounts i.e., each of the "minor" components represents less than about 5 percent by weight of the total weight of the composition
  • minor amounts i.e., each of the "minor" components represents less than about 5 percent by weight of the total weight of the composition
  • minor amounts i.e., each of the "minor" components represents less than about 5 percent by weight of the total weight of the composition
  • minor amounts i.e., each of the "minor" components represents less than about 5 percent by weight of the total weight of the composition
  • minor amounts i.e., each of the "minor" components represents less than about 5 percent by weight of the total weight of the composition
  • minor amounts i.e., each of the "minor" components represents less than about 5 percent by weight of the total weight of the composition
  • minor amounts i.e., each of the "minor" components represents less than about 5 percent by weight of the total weight of the composition
  • minor amounts i.e., each of the "minor" components represents less than about 5 percent by
  • the present invention provides a method for the purification of an oxybisphthalic anhydride, the method comprising steps (a)-(e) in which a "first mixture" comprising at least one oxybisphthalic anhydride, at least one solvent and at least one inorganic salt, is provided in step (a).
  • step (b) additional steps (diluting the first mixture with a solvent to provide a "second mixture” (step (b)), dissolving the oxybisphthalic anhydride present in the second mixture to provide a "third mixture” (step (c)), filtering the third mixture to provide a homogeneous solution of the oxybisphthalic anhydride (step(d)), and crystallizing the oxybisphthalic anhydride (step(e))) are carried out to provide the purified oxybisphthalic anhydride.
  • steps (a)-(e) the presence of at least one solvent is required.
  • Suitable solvents include non-polar solvents and polar aprotic solvents.
  • the "first mixture” (step (a)) comprises an aromatic solvent, for example an aromatic hydrocarbon solvent or chloroaromatic solvent.
  • the solvent has a boiling point above about 120° C, preferably above about 150° C, and more preferably above about 180 0 C.
  • Suitable aromatic solvents include, but are not limited to, toluene, xylene, mesitylene, chlorobenzene, orthodichlorobenzene (ODCB), para-dichlorobenzene, dichlorotoluene; 1,2,4- trichlorobenzene; diphenylether, dimethylsulfone, diphenyl sulfone, sulfolane, phenetole, anisole, veratrole, and mixtures thereof.
  • ODCB orthodichlorobenzene
  • diphenylether dimethylsulfone, diphenyl sulfone, sulfolane, phenetole, anisole, veratrole, and mixtures thereof.
  • one or more chlorinated aromatic solvents are employed.
  • Suitable chlorinated aromatic solvents include, but are not limited to, chlorobenzene, orthodichlorobenzene (ODCB); 2,4-dichlorotoluene; and 1,2,4-trichlorobenzene. In one embodiment 2,4-dichlorotoluene is employed. In an alternate embodiment orthodichlorobenzene is employed.
  • a relatively high boiling solvent such as the aromatic solvents exemplified here, allows for example the dissolving step (c) to be carried out at temperatures which exceed the boiling point of the solvent at relatively modest superatmospheric pressures and correspondingly higher rates of dissolution.
  • solvents provide for azeotropic distillation of water present in the mixture.
  • suitable solvents which form azeotropes with water include but are not limited to, toluene and orthodichlorobenzene.
  • solvent is distilled from the second mixture at superatmospheric pressure in order to remove water.
  • solvent is distilled from the third mixture prior to the filtration step (d).
  • solvent is distilled from the homogeneous solution of the oxybisphthalic anhydride formed in step (d) to, for example, enhance the rate and extent of crystallization in step (e).
  • solvent removal by distillation may be carried out at any point during the process and may be conducted at atmospheric pressure, subatmospheric pressure, or superatmospheric pressure.
  • the present invention provides a method for purifying an oxybisphthalic anhydride comprising as a contaminant at least one inorganic salt.
  • the origin of the inorganic salt is not limited to a particular source.
  • the at least one inorganic salt may be present as the by-product of the reaction used to form the oxybisphthalic anhydride, or the inorganic salt may be present as a contaminant from another source, for example the adventitious contamination of an oxybisphthalic anhydride by potassium chloride during handling.
  • the inorganic salt is the by-product of the reaction used to prepare the oxybisphthalic anhydride itself.
  • the sodium chloride formed as a by-product in the reaction of sodium carbonate with 4-chlorophthalic anhydride in orthodichlorobenzene at elevated temperature e.g.
  • the product of this reaction being a first mixture comprising orthodichlorobenzene solvent, solid oxybisphthalic anhydride, solid sodium chloride, and the phase transfer catalyst (PTC) hexaethylguanidium chloride.
  • an organic phase transfer catalyst such as hexaethylguanidium chloride
  • the product of this reaction being a first mixture comprising orthodichlorobenzene solvent, solid oxybisphthalic anhydride, solid sodium chloride, and the phase transfer catalyst (PTC) hexaethylguanidium chloride.
  • the at least one inorganic salt is an alkali metal halide, an alkaline earth metal halide, or a mixture thereof.
  • alkali metal halides and alkaline earth metal halides the term “mixtures thereof includes mixtures of two or more alkali metal halides, mixtures of two or more alkaline earth metal halides, and mixtures of at least one alkali metal halide with at least one alkaline earth metal halide.
  • Alkali metal halides are illustrated by sodium chloride, potassium chloride, potassium bromide, potassium fluoride, lithium bromide, cesium chloride, and lithium fluoride.
  • Alkaline earth metal halides are illustrated by, magnesium chloride, calcium chloride, calcium bromide, and barium chloride.
  • the inorganic salt present as a contaminant in the first mixture is potassium chloride.
  • the first mixture and the second mixture are substantially anhydrous, the term "substantially anhydrous" denoting a total water content of less than about 50 parts per million (ppm).
  • the first mixture is not substantially anhydrous (i.e., has a water content of more than 50 ppm, for example 500 ppm) and must be dried in either of steps (a)-(c) in order to achieve a water content of less than 25 ppm in step (c).
  • drying may be carried out conveniently by distillation of water and solvent as part of any or all of steps (a)-(c).
  • the oxybisphthalic anhydride is present in the first mixture in an amount corresponding to at least 25 percent by weight of a total weight of the first mixture. In another embodiment, the oxybisphthalic anhydride is present in the first mixture in an amount corresponding to at least 35 percent by weight of a total weight of the first mixture. In yet another embodiment, the oxybisphthalic anhydride is present in the first mixture in an amount corresponding to at least 50 percent by weight of a total weight of the first mixture.
  • the first mixture is a slurry in which a portion of the oxybisphthalic anhydride is dissolved in the solvent and a portion of the oxybisphthalic anhydride is present as a solid phase of the slurry. Owing to their generally poor solubility, the alkali metal halides and alkaline earth metal halides typically remain as solids within the first mixture.
  • the word “mixture” as used herein refers to a combination of at least two components at least one of which is at least partially insoluble in the other. Thus each of the "first mixture", the "second mixture” and the “third mixture” comprises at least one component which is at least partially insoluble.
  • the inorganic salt in the "third mixture", although substantially all of the oxybisphthalic anhydride has been dissolved in the solvent, at least a portion of the inorganic salt remains insoluble and is present as a solid phase component of the mixture.
  • the inorganic salt is highly insoluble in the "third mixture” allowing separation of the inorganic and organic components of the mixture by filtering off the inorganic salt.
  • a first mixture provided in step (a) is diluted with at least one solvent in step (b) to provide a second mixture wherein the oxybisphthalic anhydride is present in an amount corresponding to less than 25 percent by weight of the total weight of the second mixture.
  • the oxybisphthalic anhydride is present in an amount corresponding to less than 15 percent by weight of the total weight of the second mixture.
  • the oxybisphthalic anhydride is present in an amount corresponding to less than 10 percent by weight of the total weight of the second mixture.
  • the solvent employed in diluting the first mixture is orthodichlorobenzene.
  • the solvent employed is at least one solvent selected from the group consisting of para-dichlorobenzene, dichlorotoluene, 1,2,4-trichlorobenzene, diphenyl sulfone, phenetole, anisole, veratrole, toluene, xylene, mesitylene and mixtures thereof.
  • the solvent employed comprises orthodichlorobenzene and at least one other aromatic solvent.
  • substantially all of the oxybisphthalic anhydride present in the second mixture is dissolved in the solvent to form a third mixture (step (c)).
  • at least 90 percent of the oxybisphthalic anhydride is dissolved.
  • at least 95 percent of the oxybisphthalic anhydride is dissolved.
  • at least 98 percent of the oxybisphthalic anhydride is dissolved.
  • Suitable solvents include those discussed herein, for example anisole and chlorobenzene. Typically, a single solvent is employed in each of steps (a)-(e). Orthodichlorobenzene is in certain instances a preferred solvent.
  • the dissolving of the oxybisphthalic anhydride is effected by heating the second mixture to a temperature in the range from about 80 0 C to about 220 0 C. In one embodiment, the dissolving of the oxybisphthalic anhydride is effected by heating the second mixture to a temperature in the range from about 100 0 C to about 200 0 C. In another embodiment, the dissolving of the oxybisphthalic anhydride is effected by heating the second mixture to a temperature in the range from about 13O 0 C to about 180 0 C. Upon dissolution of substantially all of the oxybisphthalic anhydride the "third mixture" is formed. Typically this third mixture comprises less than 25 ppm water.
  • the third mixture comprises less than 15 ppm water. In yet another embodiment the third mixture comprises less than 5 ppm water. It is believed that it is generally preferable that the third mixture contain as little water as possible.
  • the presence of water in any of steps (a)-(e) is thought to contribute to water in the final oxybisphthalic anhydride product. Higher concentrations of water are thought to be the source of higher than desired levels of alkali metal ions in the product oxybisphthalic anhydride.
  • step (d) the third mixture is filtered to separate the insoluble inorganic salt from the dissolved oxybisphthalic anhydride.
  • the filtration is carried out at a temperature above the crystallization point temperature of the oxybisphthalic anhydride in order to avoid crystallization within the device used to effect the filtration.
  • the crystallization point temperature is a function of a number of parameters including the concentration of the dissolved oxybisphthalic anhydride in the solvent, the properties of the solvent, the structure of the oxybisphthalic anhydride, and the state of purity of the oxybisphthalic anhydride (e.g. mixtures of isomeric oxybisphthalic anhydrides versus single isomer oxybisphthalic anhydrides).
  • the crystallization point temperature is typically in a range from about - 15°C to about 200 0 C.
  • the filtration device is a porous filter which can be heated to maintain a temperature above the crystallization point temperature of the oxybisphthalic anhydride.
  • the filtration step yields a filtrate which is a homogenous solution of the oxybisphthalic anhydride in the solvent, and a filter cake, the filter cake being comprised of the solid components of the third mixture.
  • the filter cake typically contains the inorganic salt as the major component together with a lesser amount of the oxybisphthalic anhydride.
  • the data in Table 3 illustrate embodiments of the invention in which from about 8.75 to about 10.72 percent of the total amount of oxybisphthalic anhydride present initially in the first mixture form part of the filter cake produced in step (d).
  • the filtering is carried out at a temperature in a range from about 50 0 C to about 250 0 C, in another embodiment from about 100 0 C to about 225°C, and in yet another embodiment from about 125°C to about 190 0 C.
  • the filtering is carried out at (0 PSIG) or near (5-25 PSIG) atmospheric pressure under an inert atmosphere, for example under a nitrogen atmosphere. Filtering may be carried out employing methods known in the art.
  • the filtering is carried out in a metal filter.
  • the filtering is carried out in a ceramic filter.
  • the filter is a sintered metal filter.
  • the filter is a metal filter having a pore size in a range from about 0.5 microns to about 5 microns.
  • the filter employed has a pore size in a range from about 0.1 microns to about 10 microns, alternately from about 0.2 microns to about 5 microns.
  • the filter cake is washed with hot solvent to recover product oxybisphthalic anhydride trapped in the filter cake thereby improving the yield of the product.
  • step (e) crystallization of the oxybisphthalic anhydride from the homogenous solution is effected.
  • the crystallization is effected using conventional techniques that are well known in the art at a temperature corresponding to the crystallization point temperature or a lower temperature.
  • crystallization of the oxybisphthalic anhydride from the homogenous solution is typically effected at a temperature in a range from about -15°C to about 200°C.
  • the crystallization is effected at a temperature in a range of from about -10 0 C to about 120 0 C.
  • crystallization is effected at a temperature in a range from about 0 0 C to about 80 0 C.
  • the crystallization is effected in a vessel equipped with an agitator.
  • the product of the crystallization step is a slurry of the crystallized oxybisphthalic anhydride in the solvent.
  • the crystallized oxybisphthalic is typically of significantly higher purity than the oxybisphthalic anhydride initially provided in step (a).
  • the purified oxybisphthalic anhydride contains less than about 100 ppm, in another embodiment less than about 50 ppm, in yet another embodiment less than about 30 ppm, and in still yet another embodiment less than about 10 ppm of alkali metal ions, alkaline earth metal ions or mixtures thereof.
  • the product of the purification method is a purified slurry of oxybisphthalic anhydride in at least one solvent , said slurry containing less than about 100 ppm, in another embodiment less than about 50 ppm, in yet another embodiment less than about 30 ppm, and in still yet another embodiment less than about 10 ppm of alkali metal ions, alkaline earth metal ions or mixtures thereof.
  • the present invention provides a method of preparing a purified oxybisphthalic anhydride.
  • at least one substituted phthalic anhydride IH is substituted phthalic anhydride
  • X 1 is selected from the group consisting of fluoro, chloro, bromo, iodo, and nitro groups; is contacted in a reaction mixture comprising at least one aprotic solvent, at least one phase transfer catalyst, and at least one inorganic carbonate to provide a product mixture comprising a product oxybisphthalic anhydride I in an amount corresponding to at least 25 percent by weight of the total weight of the product mixture.
  • Suitable substituted phthalic anhydrides include, 3-chlorophthalic anhydride, 4- chlorophthalic anhydride, 3-fluorophthalic anhydride, 4-fluorophthalic anhydride, 4- nitrophthalic anhydride, 3-nitrophthalic anhydride, and mixtures thereof.
  • Phase transfer catalysts are known in the art; reference is made, for example, to U.S Patent 5,081,298.
  • Typical catalysts include hexaalkylguanidinium halides, pyridinium halides, phosphazenium salts and the like.
  • Representative hexaalkylguanidinium halides are illustrated by formula IV; while representative pyridinium halides are shown in formula V; and representative phosphazenium catalysts are shown in formula VI.
  • R'-R independently represent a Cj- C20 aliphatic radical, a C 3 - C 40 aromatic radical, or a C 3 - C 20 cycloaliphatic radical; and X ' is a monovalent inorganic anion, a monovalent organic anion, a polyvalent inorganic anion, polyvalent organic anion, or a mixture thereof.
  • p is an integer from zero to 10.
  • two or more of the groups represented by R'-R 11 when present in the same structure, may be linked together form a cyclic structure comprising at least one nitrogen atom.
  • Suitable phase transfer catalysts having general structure IV are illustrated by hexaethylguanidium mesylate, hexaethylguanidium chloride, hexaethylguanidium bromide, hexaethylguanidium acetate, and combinations thereof.
  • phase transfer catalysts having general structure V are illustrated by l-neopentyl-4-(N,N-dibutylamino)-pyridinium chloride, l-neopentyl-4- ⁇ iperidin-l-ylpyridinium chloride, l-neopentyl-4-piperidin-l- ylpyridinium mesylate, l-3-methylheptyl-4-(4-methyl)-piperidin-l-ylpyridinium chloride, and combinations thereof.
  • the amount of phase transfer catalyst is typically used in an amount corresponding to from about 0.1 mole percent to about 10 mole percent based on the total number of moles of substituted phthalic anhydride employed.
  • the phase transfer catalyst is a guanidinium salt comprising the structure VII
  • each of R 12 , R 13 , R 14 , R 15 , R 16 and R 17 is independently Ci- C 20 aliphatic radical, a C 3 - C40 aromatic radical, or a Cj- C 20 cycloaliphatic radical.
  • at least two or more of R 12 , R 13 , R 14 , R 15 , R 16 and R 17 may together form a cycloaliphatic radical or an aromatic radical comprising at least one nitrogen atom.
  • the anionic species, X ' represents one or more monovalent inorganic anions, monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions, and mixtures thereof, "n" is 1 or 2.
  • Suitable phase transfer catalysts having structure VII include the bisguanidinium salt wherein R 12 , R 13 , R 14 , R 15 , R 16 are methyl groups, R 17 is a 1,3- propanediyl radical (i.e., -CH 2 CH 2 CH 2 -), "n" is 2, and X " represents two chloride anions.
  • M is a metal ion selected from the group consisting of alkali metal ions, alkaline earth metal ions, and mixtures thereof, and Y is OM or OH.
  • the metal ion M is lithium, sodium, potassium, or a mixture thereof.
  • Suitable inorganic carbonates include potassium carbonate, sodium carbonate, potassium sodium carbonate, lithium carbonate, potassium lithium carbonate, sodium lithium carbonate, potassium bicarbonate, sodium bicarbonate, lithium bicarbonate, and mixtures thereof.
  • the amount of inorganic carbonate and said substituted phthalic anhydride III are employed in amounts corresponding to a ratio of the inorganic carbonate to substituted phthalic anhydride in a range from about 1.0 moles to about 1.5 moles of inorganic carbonate to about 1 mole of substituted phthalic anhydride.
  • the reaction sometimes referred to herein as "contacting", of the substituted phthalic anhydride III in an aprotic solvent, at least one inorganic carbonate and said phase transfer catalyst is typically carried out by heating the reactants and solvent in a stirred reactor.
  • the reaction mixture is heated to a temperature in a range from about 50 0 C to about 250 0 C.
  • the reactor can be equipped with a means for removing solvent by distillation, such as a distillation head, condenser and receiver. Solvent may be distilled from the reaction mixture during the reaction or upon its completion as a means for removing adventitious water or water produced during the reaction.
  • the reaction results in a product mixture comprising the oxybisphthalic anhydride product and solvent together with an inorganic salt byproduct of the reaction.
  • the identity of the salt by-product is determined by the inorganic carbonate employed as well as the nature of the substituent leaving group in the substituted phthalic anhydride (X 1 in structure ITI).
  • the substituted phthalic anhydride is 4-nitrophthalic anhydride and the inorganic carbonate, is sodium carbonate
  • the salt by-product is sodium nitrite.
  • the substituted phthalic anhydride is 4-chlorophthalic anhydride and the inorganic carbonate is potassium carbonate
  • the salt by-product is potassium chloride.
  • the oxybisphthalic anhydride product is present in the product mixture in an amount corresponding to at least 25 percent by weight of the total weight of the product mixture.
  • the product mixture typically comprises less than about 100 ppm water.
  • the oxybisphthalic anhydride is then purified by diluting said product mixture with at least one solvent, to provide a second mixture wherein the oxybisphthalic anhydride is present in an amount corresponding to less than 25 percent by weight of a total weight of the second mixture.
  • the reaction mixture is then either heated or further diluted to dissolve substantially all of the oxybisphthalic anhydride present in the second mixture thereby providing a third mixture comprising less than 25 ppm water, and wherein the oxybisphthalic anhydride is present in an amount corresponding to less than 25 percent by weight of a total weight of the third mixture.
  • the third mixture is then filtered to remove the inorganic salt by-product. This filtration is carried out at a temperature above the crystallization point temperature of the oxybisphthalic anhydride and provides in addition to a filter cake comprising the inorganic salt by-product, a filtrate. In one embodiment, the filtration is carried out at a temperature in a range between about 100 0 C and about 180 0 C.
  • the filtrate is initially a homogeneous solution comprising the oxybisphthalic anhydride product and solvent.
  • the oxybisphthalic anhydride is crystallized from the homogeneous solution to provide a purified oxybisphthalic anhydride containing less than 100 ppm of alkali metal ions, alkaline earth metal ions, or mixtures thereof.
  • the present invention provides a method for preparing a polyetherimide.
  • the method comprises combining at least one solvent, at least one oxybisphthalic anhydride purified by the method of the instant invention, and at least one diamine aromatic compound to form a polymerization mixture under art recognized conditions suitable for the condensation polymerization of an oxybisphthalic anhydride with an aromatic diamine.
  • such conditions involve heating a solution of roughly equal molar amounts of the oxybisphthalic anhydride and diamine in the presence of an imidization catalyst such as sodium phenyl phosphinate (SPP, CeHsPO 2 Na).
  • SPP, CeHsPO 2 Na sodium phenyl phosphinate
  • the polymerization reaction is generally conducted under conditions such that the solvent is continuously refluxing.
  • a trap such as a Dean-Stark trap is may be employed to separate water formed during the condensation polymerization.
  • the polymerization reaction is most efficient and higher molecular weight polyetherimide product is obtained when as much water as possible is
  • the at least one diamino aromatic compound may be represented by formula (IX)
  • B is a C 3 - C3 0 divalent organic radical.
  • B is a monocyclic divalent aromatic radical, for example paraphenylene.
  • B is a polycyclic divalent aromatic radical, for example 4,4'-biphenylene or 1,4- naphtahlene.
  • B is a C 3 - C 30 divalent aromatic radical having structure (X)
  • O CF 3 a covalent bond, an alkylene group of the formula C y H 2y , or an alkylidene group of the formula C y H 2y ; wherein "y" is an integer from 1 to 5 inclusive. In some particular embodiments "y” has a value of one or two.
  • Illustrative alkylene and alkylidene linking groups Q include, but are not limited to, methylene, ethylene, ethylidene, propylene, and isopropylidene. In other particular embodiments the unassigned positional isomer about the aromatic ring in formula (X) is para to Q.
  • the two amino groups present in diamino aromatic compound IX are separated by at least two and sometimes by at least three ring carbon atoms.
  • the amino group or groups are located in different aromatic rings of a polycyclic aromatic moiety, they are often separated from the linking group between any two aromatic rings by at least two and sometimes by at least three ring carbon atoms.
  • Diamino aromatic compounds IX are illustrated by 2-methyl-l,3-.diaminobenzene; 4- methyl-l,3-diaminobenzene; 2,4,6-trimethyl-l,3-diaminobenzene; 2,5-dimethyl-l,4- diaminobenzene; 2,3,5,6-tetramethyl-l,4-diaminobenzene; l,2-bis(4- aminoanilino)cyclobutene-3,4-dione, bis(4-aminophenyl)-2,2-propane; bis(2-chloro-4-amino-3,5-diethylphenyl)methane, 4,4'-diaminodiphenyl, 3,4'- diaminodiphenyl, 3,3'-diaminodiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenyl, 3,3'- dimethoxy-4,4'-
  • two or more diamino aromatic compounds can also be used.
  • the ETHACURE diamines available from Albemarle Corporation, Baton Rouge, Louisiana, such as ETHACURE 100, which is a 80 : 20 weight ratio combination of 2,6-diethyl-4-methyl-l,3-phenylene diamine and 4,6-diethyl-2- methyl-l,3-phenylene diamine, respectively; and ETHACURE 300 which is a 80 : 20 weight ratio combination of 2,6-bis(mercaptomethyl)-4-methyl-l,3-phenylenediamine and 4,6-bis(mercaptomethyl)-2- methyl- 1,3-phenylene diamine, respectively, can also be used.
  • Perfluorinated alkyl or partially fluorinated alkyl analogs of said diamines are also suitable for use.
  • a laboratory scale hot filtration unit comprising a sintered metal (316 Stainless Steel) filter (Mott Corporation), a pressurized feed tank and a heated collection vessel.
  • Oxybisphthalic anhydride (ODPA) / potassium chloride (KCl) slurry in orthodichlorobenzene (ODCB) from ODPA synthesis comprising about 47.19 weight percent (wt%) solids was used. Based on ash analysis, the solids present in the slurry contained 38.4% KCl and 61.6% ODPA. Approximately 100 g of this slurry was then diluted with ODCB containing 57 PPM water as determined by Karl Fischer analysis. The resultant slurry was between 6 and 8-wt% ODPA.
  • the total water content of the slurry was estimated to be about 46 ppm.
  • the slurry of ODPA in ODCB was then heated to 170 0 C for 3-4 hours with agitation to dissolve the ODPA. The heating further reduced the concentration of water present in the mixture following dilution with ODCB. The concentration of water in the final heated solution was less than 25 ppm. In subsequent experiments the concentration of water present at this point was typically about 15 ppm.
  • the sintered metal filter was heated electrically to between 17O 0 C and 18O 0 C in order to keep the ODPA from crystallizing during filtration. The hot solution was then charged to the filter, and the filter was then sealed and pressurized with nitrogen gas to the pressures indicated in Table 1.
  • the filtered solution was then allowed to cool and crystallize.
  • the ODPA crystallized from the filtered solution.
  • the cool slurry was then filtered on a Buchner funnel to separate the solid ODPA from the mother liquor.
  • Fresh ODCB was used to wash the ODPA crystals of any residual mother liquor.
  • the isolated ODPA was then dried at 180°C and analyzed for potassium and other metals by ICP (Inductively-Coupled Plasma).
  • the filter cake solids resulting from the initial filtration of hot mixture of ODCB, ODPA and KCl were collected separately, weighed and then dried to remove ODCB solvent. These solids were then analyzed by ash analysis to determine the relative amounts of ODPA and KCl present. Examples 2-6 were carried out as in Example 1. Conditions selected for the filtration; low or high pressure, and low or high filter porosity, formed the basis of a design set of experiments (DOE) indicated in Table 1.
  • DOE design set of experiments
  • Example 2 The product purity for each of Examples 1-6 is shown in Table 2, where the relative amounts of each residual metal are given in parts per million (PPM) based on ICP analysis. For each Example, potassium levels below about 10 PPM were observed (Table 2). The use of the low porosity filter produced the lowest potassium levels observed, (about 1 PPM).
  • Tables 2-3 illustrate the effectiveness of the method of the present invention in the efficient purification of ODPA.
  • the diluted slurry was then heated to about 165°C in an agitated vessel to provide a solution of ODPA in ODCB containing undissolved potassium chloride.
  • the vessel was then pressurized with nitrogen to between 10 and 25 PSIG. This solution was then passed through the filter in several cycles. Each cycle ended when the pressure drop across the filter reached about 10-15 PSIG. This indicated that a significant amount of KCl solid had built up on the filter and had to be removed prior to attempting any further filtration.
  • a further dilution occurred as hot, dry ODCB was passed through the filter feed in order to dissolve any ODPA that may have crystallized on the KCl filter cake.
  • the filter was then back-flushed with hot, dry ODCB to dislodge the collected KCl from the filter. Additionally, nitrogen gas was used to force the KCl solids off the filter element and into a waste collection tank.
  • the filtrate was concentrated back to about 15 wt% ODPA from the approximately 5 wt% ODPA solution resulting from hot filtration.
  • the filtrate was then cooled and crystallized in an agitated vessel.
  • the solid ODPA was then isolated on a centrifuge.
  • the resultant ODPA crystals were then re- suspended in fresh ODCB to provide a slurry of ODPA in ODCB having a concentration of ODPA of about 15 wt%.
  • the slurry was then heated to 165°C to dissolve the ODPA.
  • the ODPA was then recrystallized by cooling.
  • the recrystallized ODPA was then isolated on a centrifuge.

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Abstract

La présente invention concerne un procédé de purification d'anhydrides oxybisphthaliques. Un premier mélange comprenant au moins un anhydride oxybisphthalique, au moins un solvant, et au moins un sel inorganique est dilué avec un solvant de sorte que la concentration d'anhydride oxybisphthalique soit inférieure à 25 pour cent en poids. Ce second mélange est ensuite chauffé pour dissoudre l'anhydride oxybisphthalique afin de fournir un troisième mélange. Le troisième mélange est ensuite filtré à une température située au-dessus de la température de cristallisation de l'anhydride oxybisphthalique. L'anhydride oxybisphthalique présent dans le filtrat est ensuite cristallisé afin de fournir un équivalent purifié en tant que bouillie. L'application de la présente invention comprend aussi un procédé de préparation d'anhydrides oxybisphthaliques et un procédé de préparation de polyétherimides comprenant des unités structurelles dérivées de l'anhydride oxybisphthalique purifié par le procédé de la présente invention.
PCT/US2007/000138 2007-01-04 2007-01-04 Procédé de purification de dianhydrides WO2008082417A1 (fr)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4870194A (en) * 1987-09-28 1989-09-26 Occidental Chemical Corporation Process for the preparation and recovery of oxdiphthalic anhydrides
US5021168A (en) * 1987-09-28 1991-06-04 Occidental Chemical Corporation Process for the preparation and recovery of oxydiphthalic anhydrides
EP0460687A2 (fr) * 1990-06-08 1991-12-11 Occidental Chemical Corporation Procédé pour la préparation d'anhydrides oxydiphtaliques et d'anhydrides acyloxyphtaliques
WO1998027047A1 (fr) * 1996-12-19 1998-06-25 Bromine Compounds Ltd. Procede de preparation de dianhydride 4,4'-oxybisphthalique
US6204394B1 (en) * 1997-12-02 2001-03-20 Manac Inc. Method for preparing oxy-diphthalic anhydrides

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4870194A (en) * 1987-09-28 1989-09-26 Occidental Chemical Corporation Process for the preparation and recovery of oxdiphthalic anhydrides
US5021168A (en) * 1987-09-28 1991-06-04 Occidental Chemical Corporation Process for the preparation and recovery of oxydiphthalic anhydrides
EP0460687A2 (fr) * 1990-06-08 1991-12-11 Occidental Chemical Corporation Procédé pour la préparation d'anhydrides oxydiphtaliques et d'anhydrides acyloxyphtaliques
WO1998027047A1 (fr) * 1996-12-19 1998-06-25 Bromine Compounds Ltd. Procede de preparation de dianhydride 4,4'-oxybisphthalique
US6204394B1 (en) * 1997-12-02 2001-03-20 Manac Inc. Method for preparing oxy-diphthalic anhydrides

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