- METHOD FOR PRODUCING BISPHENOL, AND METHOD FOR PRODUCING POLYCARBONATE RESIN
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PROBLEM TO BE SOLVED: To provide a method for producing bisphenol using hydrogen chloride gas or a hydrochloric acid as an acid catalyst, which produces bisphenol having good methanol dissolution color, melting color difference, thermal color tone stability and thermal decomposition stability, and produces a polycarbonate resin having a good color tone using the bisphenol. SOLUTION: A method for producing bisphenol includes a first step of condensing ketone or aldehyde and aromatic alcohol in the presence of hydrogen chloride to obtain a reaction liquid containing bisphenol, and a second step of mixing the reaction liquid and water, then phase-separating the mixture into a first organic phase containing bisphenol and a first aqueous phase, and removing the first aqueous phase to obtain the first organic phase. An acid concentration of the first aqueous phase in the second step is controlled to be 2.0 mmol-NaOH/g or more and 10.0 mmol-NaOH/g or less. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0123-0139
(2020/10/21)
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- Cyanate esters having flame resistant properties
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The present invention relates to novel aromatic cyanate ester compounds containing at least two rings linked by a group containing an unsaturated group. The present invention further relates to compositions and prepolymers of said novel aromatic cyanate ester compounds. The present invention further relates to a process for preparing said compounds and cured articles resulting from curable mixtures thereof.
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- Method for preparing aromatic bischloroformate compositions
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Bischloroformate oligomer compositions are prepared by passing phosgene into a heterogeneous aqueous-organic mixture containing at least one dihydroxyaromatic compound, with simultaneous introduction of a base at a rate to maintain a specific pH range and to produce a specific volume ratio of aqueous to organic phase. By this method, it is possible to employ a minimum amount of phosgene. The reaction may be conducted batchwise or continuously. The bischloroformate composition may be employed for the preparation of cyclic polycarbonate oligomers or linear polycarbonate, and linear polycarbonate formation may be integrated with bischloroformate composition formation in a batch or continuous process.
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- Bischoloroformate preparation method with phosgene removal and monochloroformate conversion
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Aqueous bischloroformates are prepared by the reaction of a dihydroxyaromatic compound (e.g., bisphenol A) with phosgene in a substantially inert organic liquid (e.g., methylene chloride) and in the presence of an aqueous alkali metal or alkaline earth metal base, at a pH below about 8. After all solid dihydroxyaromatic compound has been consumed, the pH is raised to a higher value in the range of about 7-12, preferably 9-11, and maintained in said range until a major proportion of the unreacted phosgene has been hydrolyzed. At the same time, any monochloroformate in the product may be converted to bischloroformate.
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- Cyclic monocarbonate bishaloformates
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Cyclic monocarbonate bischloroformates are prepared by the reaction of a carbonyl halide such as phosgene with a bridged substituted resorcinol or hydroquinone such as bis(2,4-dihydroxy-3-methylphenyl)methane or bis(2,5-dihydroxy-3,4,6-trimethylphenyl)methane in the presence of aqueous alkali metal hydroxide. The cyclic monocarbonate bischloroformates may be used for the preparation of linear or cyclic polycarbonates containing cyclic carbonate structural units, which may in turn be converted to crosslinked polycarbonates.
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- Polyetherimide bisphenol compositions
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Polyetherimide bisphenols and bischloroformates are prepared by the reaction of dianhydrides or certain bisimides with aminophenols or mixtures thereof with diamines. They are useful as intermediates for the preparation of cyclic heterocarbonates, which may in turn be converted to linear copolycarbonates. The bisphenols can also be converted to salts which react with cyclic polycarbonate oligomers to form block copolyetherimidecarbonates.
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- THE GENERATION AND REACTIONS OF SOME DIARYL-DIHALOMETHYLCARBONIUM IONS
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Previously unknown diaryl-dihalomethylcarbonium ions, formed in high yield from the respective alkenes in trifluoromethanesulfonic acid (triflic acid) undergo facile rapid equilibration of aryl groups in triflic acid with a second added aryl component.
- Campbell, John R.
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p. 3131 - 3134
(2007/10/02)
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