Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a single packed extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent and converting to the corresponding aromatic dianhydride. The extracting is carried out in an extraction column including a high specific surface area metal packing material and having an interface between the aqueous reaction mixture and the organic solvent that is at a level that is 14 to 85% of the height of the extraction column.

Abstract: A method for producing an aromatic dianhydride includes re-acting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent and converting to the corresponding aromatic dianhydride. The extracting is carried out in an extraction column including a high specific surface area metal packing material and having an interface between the aqueous reaction mixture and the organic solvent that is at a level that is 14 to 85% of the height of the extraction column.

Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a single packed extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Abstract: A seal nut assembly includes a locking member, a bearing member, and a resilient member. The locking member defines a threaded aperture. The bearing member has an inner annular portion and an outer annular portion which radially circumscribes the inner annular portion. The inner annular portion comprises a first lower surface and defines an opening. The outer annular portion comprises a second lower surface which is stepped with respect to the first lower surface. The bearing member is disposed adjacent to the locking member such that the opening is aligned with the threaded aperture. The resilient member is attached to the second lower surface of the bearing member adjacent to the outer perimeter. A vehicle including a seal nut assembly and a method of manufacturing a seal nut assembly are also provided.

Abstract: A retention cable arrangement for retaining a cargo closure assembly in association with a storage compartment of a vehicle includes a cargo lid door having at least one hinge for pivotally connecting the cargo door to the vehicle. A retention cable is connected to the at least one hinge and to the cargo door distal to the at least one hinge.

Abstract: A cargo protecting system for a pickup truck includes a metal support structure that is in a fixed position relative to a pickup truck. A bed floor is fixedly supported by the metal support structure, and the bed floor includes a first support surface for directly supporting cargo, wherein the first support surface is substantially coplanar with a plane. A first chamber is disposed substantially beneath the plane and can be defined by a first shell having first and second openings. The first chamber is accessible from above the plane through the first opening, and the first and second openings can be of sufficient size and dimension to allow the passage of a spare tire. Exemplary embodiments can include a second chamber disposed substantially directly beneath the bed floor and adjacent to the second opening, wherein the second chamber is separate from the first chamber and accessible from the first chamber through the second opening.