- Separation of 2,4′- and 4,4′-dihydroxydiphenyl sulfones
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To develop a procedure for separating 2,4′- and 4,4′- dihydroxydiphenyl sulfones, their acidity and solubility in water were studied. Pleiades Publishing, Inc., 2006.
- Belyaev,Vershinin,Gromov,Kuznetsov
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- Thermal recording material
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A thermal recording material having both of excellent coloring property and storage stability with a low cost is provided. The thermal recording material contains a leuco dye and a developer in a coloring layer, and the developer contains 2,4′-dihydroxydiphenylsulfone and 4,4′-dihydroxydiphenylsulfone with a specific ratio, and the above-mentioned two kinds of the dihydroxydiphenylsulfones are made a material obtained by sequentially undergoing a separating step for heightening the weight ratio of a 2,4′ material from a dichlorodiphenylsulfone mixture containing the 2,4′ material and a 4,4′ material, a reaction step of hydrolyzing the mixture to obtain a dihydroxydiphenylsulfone mixture, and a post-treatment step of subjecting to decolorization and purification.
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Page/Page column 18
(2016/09/26)
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- Liquid-crystal aromatic polyesters containing azo and sulfone units
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Two novel aromatic polyesters containing azo and sulfone units were synthesized by poly-condensation of 4,4′-azobenzene-dicarbonyl chloride with dihydroxydiphenyl sulfones at low temperature. The synthesized polymers exhibited good solubility, inherent viscosity (reaches 1.05 dL g-1), high glass transition temperature (above 200 °C) and thermal stability (≤ 5 % weight loss at 348 °C), which were characterized by Fourier transform infrared spectroscopy. The liquid crystalline and photoisomerization properties were observed by polarizing optical microscope and an ultraviolet-visible spectrophotometer.
- Qiu, Ming Yan,Niu, Yong Sheng,Yu, You Zhu,Guo, Yu Hua
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p. 7759 - 7762
(2015/02/02)
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- COLOR DEVELOPING COMPOSITION CONTAINING MOLECULAR COMPOUND, AND RECORDING MATERIAL
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Provided is a color-developing composition containing a molecular compound which has as a component compound a compound represented by formula (I) [wherein Y represents a C1-C12 hydrocarbon group which is chained or branched and saturated or unsaturated, or a C1-C8 hydrocarbon group which is chained or branched, saturated or unsaturated and has an ether or thioether bond; R1, R2, R3 and R4 each independently represent a C1-C6 alkyl group or C2-C6 alkenyl group; n, p, q and r each represents any integer of 0 to 4; and m represents any integer of 0 to 2]. Also provided is a recording material with a sufficient color-forming sensitivity, superior storage stability, and especially with an extremely little background fogging in a heat resistance test.
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- PROCESS FOR THE PRODUCTION OF A SULFONE MONOMER
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The present invention provides an economic and environmentally friendly method for the preparation of polymer grade 4,4'-dichlorodiphenyl sulfone which is substantially free of 2,4' and 3,4'-isomers of dichlorodiphenyl sulfone with yield of over 90%, with substantially reduced reaction times without the use of impregnated catalysts. Further no toxic byproducts such as dimethyl pyrosulfate are formed thereby reducing the load on effluent treatment with the added advantage of substantially recycling the reactants and byproducts. Further the present invention discloses a process is disclosed in which isomeric mixture of 4,4'-, 3,4'-, and 2,4'-dichlorodiphenyl sulfone produced during the preparation of 4,4'-dichlorodiphenyl sulfone is converted to value added products such as diphenyl sulfone, 2,4'- dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfone and 2-aminodiphenyl sulfone.
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Page/Page column 36
(2011/06/25)
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- Process for producing high-purity 4,4'-dihydroxydiphenyl sulfone
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The present invention provides a process for producing 4,4′-dihydroxydiphenylsulfone of very high purity. In particular, the present invention provides a process for producing 4,4′-dihydroxydiphenylsulfone of high purity comprising the steps of subjecting phenol in combination with a sulfonating agent or phenolsulfonic acid to a dehydration reaction in the presence of an aromatic nonpolar solvent while suspending the resulting dihydroxydiphenylsulfone therein, mixing the reaction suspension with a polar solvent to at least partially dissolve the dihydroxydiphenylsulfone, and precipitating 4,4′-dihydroxydiphenylsulfone.
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Page/Page column 5-6
(2008/06/13)
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- PROCESS FOR PRODUCING 4,4-BISPHENOL SULFONE
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A process for producing 4,4'-bisphenol sulfone by reacting phenol with sulfuric acid, which includes conducting a dehydration reaction in a mixed solvent including an aliphatic saturated hydrocarbon having a boiling point of 175°C or higher and mesitylene, and finally distilling off the mesitylene from the reaction system, or includes conducting the reaction in a solvent including an aliphatic saturated hydrocarbon in a reaction vessel equipped with a fractionating device. Thus, 4,4'-bisphenol sulfone can be produced in high yield with a high operating efficiency. Also, provided is a process for easily producing 4,4'-bisphenol sulfone having a high purity which includes conducting the reaction in a solvent containing an aliphatic saturated hydrocarbon, subsequently adding a C1-3 alcohol to the reaction mixture, separating an alcohol layer, and recrystallizing the 4,4'-bisphenol sulfone from the alcohol layer.
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Page column 15
(2008/06/13)
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- PROCESS FOR PRODUCING MIXTURE OF DIHYDROXYDIPHENYLSULFONE ISOMERS
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The present invention provides a process for producing a mixture of dihydroxydiphenylsulfone isomers containing 2,4'-dihydroxydiphenylsulfone, the process comprising heating 4,4'-dihydroxydiphenylsulfone or a mixture of dihydroxydiphenylsulfone isomers containing at least 85 wt.% of 4,4'-dihydroxydiphenylsulfone in the presence of phenol and sulfuric or sulfonic acid.
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- PROCESS FOR PRODUCING MIXTURE OF DIHYDROXYDIPHENYLSULFONE ISOMERS
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The present invention provides a process for producing a mixture of 4,4'- and 2,4'-dihydroxydiphenylsulfones comprising heating trihydroxytriphenyldisulfone or a mixture of dihydroxydiphenylsulfone isomers containing trihydroxytriphenyldisulfone in the presence of phenol and an acid catalyst.
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- PROCESS FOR PRODUCING 2,4'-DIHYDROXYDIPHENYL SULFONE
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A process for producing 2,4'-dihydroxydiphenylsulfone which comprises separating 4,4'-dihydroxydiphenylsulfone by crystallization from a mixture containing 4,4'-dihydroxydiphenylsulfone, 2,4'-dihydroxydiphenylsulfone, phenolsulfonic acid and phenol which is obtained by dehydration of phenol and sulfuric acid or phenolsulfonic acid to obtain a mixture having a content of 2,4'-dihydroxydiphenylsulfone greater than the content of 4,4'-dihydroxydiphenylsulfone, crystallizing 2,4'-dihydroxydiphenylsulfone by adjusting the composition of the solvent of the obtained mixture so that the ratio of the amounts by weight of phenol to water is 10:90 to 90:10, and separating 2,4'-dihydroxydiphenylsulfone by filtration; and a process as described above in which the filtrate obtained by the filtration is used as the raw material for the hydration.
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- Process for producing a high purity 2,4-dihydroxydiphenylsulfone
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A process for producing a high purity 2,4'-dihydroxydiphenylsulfone (2,4'-isomer) comprising separating 2,4'-isomer from 4,4'-dihydroxydiphenylsulfone (4,4'-isomer) by adding a hydroxide of an alkali metal in an amount which is the total of an amount by mol 1.6 to 2.2 times as great as the amount by mol of 2,4'-isomer and an amount by mol 0.8 to 1.2 times as great as the amount by mol of 4,4'-isomer to a solution of a mixture of 2,4'-isomer and 4,4'-isomer containing 15% by weight or more of 2,4'-isomer in water, to allow 2,4'-isomer to remain dissolved in water in the form of a dialkali metal salt thereof and 4,4'-isomer to be precipitated from the solution in the form of a monoalkali metal salt thereof. A carbonate of an alkali metal may also be used. In order to accelerate the operation, an excess amount of the alkali may be added, which is subsequently neutralized. A high purity 2,4'-isomer having a purity of 95 to 99.5% by weight can be obtained easily with a high yield from a mixture of the isomers containing 15% by weight or more of 2,4'-isomer.
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- Method of producing A 2,4'-dihydroxydiphenylsulfone
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High purity 2,4'-dihydroxydiphenylsulfones useful as developers for thermal recording paper can be produced efficiently and with high selectivity by reacting one or more phenols and sulfuric acid in the presence as of at least one of phosphonic acid, phosphinic acid and salts thereof, in the absence of a solvent or in the presence of an aromatic hydrocarbon solvent having a boiling point at atmospheric pressure of 130° to 200° C., and then purifying the thus-produced crude 2,4'-dihydroxydiphenylsulfones using a mixed solvent containing (1) 5 to 20 weight % of at least one lower aliphatic alcohol and 95 to 80 weight % of at least one aromatic hydrocarbon which does not contain halogen, (2) 10 to 40 weight % of at least one ketone and 90 to 60 weight % of at least one aromatic hydrocarbon which does not contain halogen or (3) 10 to 40 weight % of at least one ester of acetic acid and 90 to 60 weight % of at least one aromatic hydrocarbon which does not contain halogen.
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- Preparation of 4,4'-dihydroxydiphenylsulfones
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A phenol is reacted with sulphur trioxide in the presence of liquid hydrogen fluoride to form a 4,4'-dihydroxydiphenylsulphone. A molar excess of hydrogen fluoride and stoichiometric proportions of sulphur trioxide and phenol or a slight excess of sulphur trioxide over phenol are preferred.
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- Bisfluoran chromogenic compounds, preparation thereof, and pressure-sensitive copy systems employing same
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A substantially colorless bisfluoran chromogenic material having the structural formula STR1 wherein R1 and R2 each represent an alkyl group; X and Y each represent a hydrogen atom, a halogen atom, an hydroxyl group, an alkyl group, a nitro group, an amino group, an acyl group, or a carboalkoxy group; Z represents an oxy radical, a carbonyl group, an alkylene group, an alkylidene group, a sulfonyl group, or a thio radical; and n represents an integer from 0 to 1. The bisfluoran compounds are produced by reacting a 4-dialkylamino-2-hydroxy-2'-carboxybenzophenone with a diphenol wherein the diphenol is unsubstituted in at least one of the positions ortho to an hydroxyl group in each of the phenyl rings. The bisfluorans are used in pressure-sensitive copy systems comprising a support bearing microcapsules containing the bisfluorans, alone, or in combination with other color-forming materials.
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