摘要:
A method for recovering substantially pure p,p-bisarylols from a mixture comprising the same by subjecting the mixture to vacuum distillation and melt crystallization in the absence of an adduct crystallization and the generation of a reaction recycle stream.
摘要:
Hydroxyaromatic compounds such as phenol are converted to diaryl carbonates by reaction with oxygen and carbon monoxide in the presence of a catalyst package which comprises a Group VIIIB metal, preferably palladium, salt of at least one aliphatic .beta.-diketone such as 2,4-pentanedione. The catalyst package also preferably comprises an inorganic cocatalyst, an organic cocatalyst and a bromide or chloride, preferably bromide, source such as a hexaalkylguanidinium bromide. The use of the .beta.-diketone salt confers such advantages as long shelf life under normal storage conditions, high activity upon recycle and capability of carbonylation at relatively low temperatures.
摘要:
Catalytic materials including divalent palladium compounds, divalent cobalt compounds and bromide sources such as tetraalkylammonium and hexaalkylguanidinium bromides are removed from organic carbonylation reaction mixtures comprising said materials in combination with diaryl carbonate and hydroxyaromatic compound. The removal steps include extraction with an aqueous complexing solution for palladium, extraction with an aqueous non-basic and preferably ionic extractant for cobalt, and extraction with water to remove bromide source. These steps may be combined into an integrated process. Further steps of recycle of the palladium by reduction to elemental palladium and conversion to a catalytically active species, and conversion of cobalt to a catalytically active species, may be included in the integrated process.
摘要:
Hydroxyaromatic compounds such as phenol are converted to diaryl carbonates by reaction with oxygen and carbon monoxide in the presence of a catalyst package which typically comprises a group VIIIB metal or compound thereof, an inorganic cocatalyst, an organic cocatalyst and a hexaalkylguanidinium bromide or chloride, preferably bromide. The use of the hexaalkylguanidinium salt causes an increase in the yield of diaryl carbonate without a decrease in selectivity.
摘要:
Hydroxyaromatic compounds such as phenol are converted to diaryl carbonates by reaction with oxygen and carbon monoxide in the presence of a catalyst package and an added diluent free from active hydrogen. The preferred catalyst packages comprise a Group VIIIB metal or salt thereof, an inorganic cocatalyst, and organic cocatalysts and a bromide or chloride source. The amount of added diluent is an effective amount to improve selectivity to diaryl carbonate. Preferred diluents are diphenyl carbonate and N-methylpyrrolidone.
摘要:
Adducts of hydroxyaromatic compounds such as phenol and diaryl carbonates such as diphenyl carbonate are washed with a washing composition comprising a major proportion, typically about 90%, of the hydroxyaromatic compound and a minor proportion, typically about 10%, of the diaryl carbonate.
摘要:
Phenol and isopropenylphenol are recovered from BPA tars by sparging the fluidized BPA tar while heating in the presence of a basic catalyst. Sparging dramatically increases the efficiency of phenol and isopropenylphenol recovery. Recovered isopropenylphenol may be converted to bisphenol A in the distillate by reaction with phenol and an acidic catalyst.
摘要:
Hydroxyaromatic compounds such as phenol are converted to diaryl carbonates by reaction with oxygen and carbon monoxide in the presence of a catalyst package which typically comprises a group VIIIB metal or compound thereof, an inorganic cocatalyst, an organic cocatalyst and a hexaalkylguanidinium bromide or chloride, preferably bromide. The use of the hexaalkylguanidinium salt causes an increase in the yield of diaryl carbonate without a decrease in selectivity.
摘要:
A polyetherimide resin is described herein. The resin includes a structure of repeating units of the formula (I) wherein each aromatic ring in the structure can be substituted with at least one halogen atom, nitro group, cyano group, alkyl group, cycloalkyl group, or aryl group. Another embodiment relates to a method for preparing a polyetherimide polymer. The method includes the step of reacting metaphenylenediamine bis(4-nitrophthalimide) with a bisphenolic mixture of a salt of bisphenol A and a salt of an arylcyano-modified bisphenol.
摘要:
A monomer and polycarbonate resin are provided, as are methods of making the monomer. The resin may be used to provide a thin film that has a higher dielectric constant and higher glass transition temperature, and similar breakdown strength and similar dissipation factor to films prepared from polycarbonate resins not so modified. The thin films, in turn, may advantageously be used to form, wholly or in part, articles such as capacitors, sensors, batteries, flexible printed circuit boards, keyboard membranes, motor/transformer insulations, cable wrappings, industrial tapes, interior coverage materials, and the like. In particular, a capacitor comprising the polycarbonate resin is also provided.