Method for the manufacture of halophthalic acids and anhydrides

A method for the manufacture of halophthalic anhydride comprising:

• forming a reaction mixture comprising:
• a mixture of about 7 to about 3 parts by weight of acetic acid to 1 part by weight of a halo-ortho-xylene,
• about 0.25 to about 2 mole percent, based on said halo-ortho-xylene, of a cobalt source,
• about 0.1 to about 1 mole percent, based on said halo-ortho-xylene, of a manganese source,
• about 0.01 to about 0.1 mole percent, based on said halo-ortho-xylene, of a source of a metal selected from zirconium, hafnium and mixtures thereof,
• about 0.02 to about 0.05 mole percent, based on said halo-ortho-xylene, of a bromide source,
• maintaining said reaction mixture at a pressure of at least about 1600 Kpa and at a temperature of about 150° C. to about 170° C.;
• introducing a molecular oxygen containing gas to said reaction mixture at a rate of at least about 0.5 normal m3 of gas/kg of halo-ortho-xylene in said reaction mixture to create an oxygen containing off gas from said reaction mixture, wherein said oxygen concentration of said off gas is less than about three percent by volume of said off gas;
• maintaining said introduction of said molecular oxygen containing gas until the oxygen concentration in said off gas exceeds about 3 percent by volume of said off gas and then stopping the introduction of said molecular oxygen containing gas;
• and
• modifying the introduction of said molecular oxygen containing gas to maintain the oxygen concentration in said off gas at a concentration below about 5 percent by volume of said off gas and maintaining the modified introduction of molecular oxygen containing gas for a time sufficient to provide at least about 90 percent conversion of said halo-ortho-xylene to halophthalic acid with less than about 600 parts per million (ppm) of halophthalide;
• removing said acetic acid and any water formed as a result of the reaction by distillation;
• dehydrating said halophthalic acid to form halophthalic anhydride.

A method for the manufacture of halophthalic acid comprising:

• forming a reaction mixture comprising:
• a mixture of about 7 to about 3 parts by weight of acetic acid to 1 part by weight of a halo-ortho-xylene,
• about 0.8 to about 1.2 mole percent,l based on said halo-ortho-xylene, of a cobalt source, about 0.4 to about 0.6 mole percent, based on said halo-ortho-xylene, of a manganese source,
• about 0.04 to about 0.06 mole percent, based on said halo-ortho-xylene, of a source of a metal selected from zirconium, hafnium and mixtures thereof,
• less than about 0.04 mole percent, based on said halo-ortho-xylene, of a bromide source,
• maintaining said reaction mixture at a pressure of at least about 1600 Kpa and at a temperature of about 150° C. to about 170° C.;
• introducing air to said reaction mixture at a rate of at least about 1.0 normal m3 of gas/kg of halo-ortho-xylene in said reaction mixture to create an oxygen containing off gas from said reaction mixture, wherein said oxygen concentration of said off gas is less than about 3 percent by volume of said off gas;
• maintaining said introduction of said air until the oxygen concentration in said off gas exceeds about 3 percent by volume of said off gas;
• and
• modifying the introduction of said air to maintain the oxygen concentration in said off gas at a concentration below about 5 percent by volume of said off gas and maintaining the modified introduction of air for a time sufficient to provide at least about 90 percent conversion of said halo-ortho-xylene to halophthalic acid.

A method for the manufacture of halophthalic anhydride comprising:

• forming a reaction mixture comprising:
• a mixture of about 7 to about 3 parts by weight of acetic acid to 1 part by weight of a halo-ortho-xylene,
• about 0.8 to about 1.2 mole percent based on said halo-ortho-xylene, of cobalt acetate or cobalt acetate hydrate,
• about 0.4 to about 0.6 mole percent, based on said halo-ortho-xylene, of manganese acetate or manganese acetate hydrate,
• about 0.04 to about 0.06 mole percent, based on said halo-ortho-xylene, of zirconium acetate or zirconium acetate hydrate,
• less than about 0.04 mole percent, based on said halo-ortho-xylene, of sodium bromide;
• maintaining said reaction mixture at a pressure of at least about 1600 Kpa and at a temperature of about 150° C. to about 170° C.;
• introducing air to said reaction mixture at a rate of at least about 0.5 normal m3 of gas/kg of halo-ortho-xylene in said reaction mixture to create an oxygen containing off gas from said reach on mixture, wherein said oxygen concentration of said off gas is less than about one percent by volume of said off gas;
• maintaining said introduction of said air until the oxygen concentration in said off gas exceeds about 3 percent by volume of said off gas;
• and
• modifying the introduction of air to maintain the off gas oxygen concentration below about 5 percent by volume of said off gas and maintaining the modified introduction of air for a time sufficient to provide at least about 90 percent conversion of said halo-ortho-xylene to halophthalic acid;
• removing said acetic acid aid and any water formed as a result of the reaction by distillation;
• recycling said acetic acid;
• dehydrating said halophthalic acid to form halophthalic anhydride.

A method for the manufacture of polyetherimide comprising:

• forming a reaction mixture comprising:
• a mixture of about 7 to about 3 parts by weight of acetic acid to 1 part by weight of a halo-ortho-xylene,
• about 0.25 to about 2 mole percent based on the halo-ortho-xylene, of a cobalt source, about 0.1 to about 1 mole percent, based on the halo-ortho-xylene, of a manganese source,
• about 0.01 to about 0.1 mole percent, based on the halo-ortho-xylene, of a source of a metal selected from zirconium, hafnium and mixtures thereof,
• about 0.02 to about 0.05 mole percent, based on the halo-ortho-xylene, of a bromide source;
• maintaining the reaction mixture at a pressure of at least about 1600 Kpa and at a temperature of about 150° C. to about 170° C.;
• introducing a molecular oxygen containing gas to the reaction mixture at a rate of at least about 1.0 normal m3 of gas/kg of halo-ortho-xylene in the reaction mixture to create an oxygen containing off gas, wherein the off gas oxygen concentration is less than about 3 percent by volume of the off gas;
• maintaining the introduction of the, molecular oxygen containing gas until the off gas oxygen concentration exceeds about 3 percent by volume of the off gas;
• modifying the introduction of the molecular oxygen containing gas so as to maintain the off gas oxygen concentration at a concentration below about 5 percent by volume of the off gas and maintaining the modified introduction of molecular oxygen containing gas for a time sufficient to provide at least about 90 percent conversion of the halo-ortho-xylene to halophthalic acid with less than about 600 parts per million (ppm) of halophthalide;
• removing the acetic acid and any water formed as a result of the reaction by distillation;
• dehydrating the halophthalic acid to, form halophthalic anhydride;
• reacting the halophthalic anhydride with 1,3-diaminobenzene to form bis(halophthalimide) (II)
• wherein X is a halogen;
• and
• reacting bis(halophthalimide) (II) with an alkali metal salt of a dihydroxy substituted aromatic hydrocarbon having the formula (IV)
• OH—A2OH (IV)
• wherein A2 is a divalent aromatic hydrocarbon radical to form the polyetherimide.