摘要:
A process for preparing a diaryl carbonate from a diaryl oxalate in a liquid phase by decarbonylation is conducted by the steps of:1) performing a decarbonylation reaction of a diaryl oxalate in the presence of an organic phosphorus compound catalyst to give a reaction mixture of a diaryl carbonate and the organic phosphorus compound catalyst;2) recovering the diaryl carbonate from the reaction mixture; and3) performing a decarbonylation reaction of a diaryl oxalate in the presence of the reaction mixture from which the diaryl carbonate has been recovered and to which a halogen atom-containing compound is added, to give a reaction mixture of a diaryl carbonate and the organic phosphorus compound catalyst.
摘要:
A diaryl carbonate with a high degree of purity is produced at a high yield by (A) subjecting (a) a diaryl oxalate and a phenol compound or (b) an alkylaryl oxalate to transesterification reaction in one or two stages in the presence of a catalyst to prepare a diaryl oxalate, while removing a by-product from the reaction system; (B) collecting the diaryl oxalate from the resultant reaction product mixture of the step (A); (C) subjecting the diaryl oxalate to a decarbonylation reaction, preferably in the presence of a phosphorous compound-containing catalyst, to convert the diaryl oxalate to a corresponding diaryl carbonate, while removing a reaction by-product comprising carbon monoxide from the reaction system; and (D) collecting the diaryl carbonate from the reaction product mixture of the step (C).
摘要:
A composition consisting essentially of a diaryl carbonate and contains a furan ring-containing compound in an amount of not more than 1 ppm is favorably employable for producing less colored polycarbonate.
摘要:
An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactor 2, which aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column 1.
摘要:
An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactor 2, which aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column 1.
摘要:
An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactor 2, which aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column 1.
摘要:
A novel crystalline adduct of diphenyl oxalate and phenol in a molar ratio of 1:2 and having a high purity is produced by melting a mixture containing diphenyl oxalate and phenol at a temperature of 100.degree. C. or more; cooling the melt to a temperature of less than 100.degree. C. to allow a resultant adduct of diphenyl oxalate and phenol in a molar ratio of 1:2 to crystallize and deposit from the melt; and collecting the crystalline adduct. Diphenyl oxalate with a high purity is produced by melting the crystalline adduct to dissociate it into diphenyl oxalate and phenol, and evaporating away the dissociated phenol from the melt to collect the dissociated diphenyl oxalate.
摘要:
Disclosed is a process for preparing a diaryl oxalate which comprises the step of transesterifying a dialkyl oxalate or/and an alkylaryl oxalate with an aryl alcohol in the presence of a tetra(aryloxy)titanium as a catalyst, wherein the tetra(aryloxy)titanium is fed into a reaction system of the transesterification as an aryl alcohol solution of the tetra(aryloxy)titanium which is prepared by reacting a tetraalkoxy titanium and an excess amount of the aryl alcohol and removing a by-producing alkyl alcohol.
摘要:
There is provided a process for preparing 1,6-hexanediol by esterifying a carboxylic acid mixture resulted from oxidation of cyclohexane with oxygen, and then hydrogenating the esters, which substantially does not contain a compound leading to a high ester value.A process for preparing 1,6-hexanediol from a carboxylic acid mixture containing adipic acid and 6-hydroxycaproic acid, the carboxylic acid mixture is obtained as a by-product in oxidization of cyclohexane to cyclohexanone/cyclohexanol using oxygen or an oxygen-containing gas, the process comprises esterifying the acids with an alcohol, followed by hydrogenation, and the process is characterized by comprising the following steps of: a) separating a component having a boiling point lower than that of water and the alcohol used in the esterification from a mixture obtained by the hydrogenation in a first distillation step; b) separating an EV component having a boiling point higher than that of 1,6-hexanediol further in a second distillation step; c) separating an EV component having a boiling point lower than that of 1,6-hexanediol further in a third distillation step; and then d) obtaining 1,6-hexanediol in a fourth distillation step, in this order.
摘要:
A method is provided for producing highly pure 1,6-hexanediol in which the contents of impurities such as 1,4-cyclohexanediol, 1,5-hexanediol, 1,2-cyclohexanediol, 1,7-pentanediol, 1,5-pentanediol and high boiling point components are significantly reduced. The process contains the steps of (1) treating an aqueous extraction concentrate of a reaction mixture obtained by oxidation of cyclohexane with a lower alcohol to esterify monocarboxylic acids and dicarboxylic acids contained in the extract, and simultaneously removing and separating by distillation water, excess lower alcohols and carboxylic acid esters; (2) converting oligomer esters contained in the bottom liquid to carboxylic acid esters by depolymerizing the oligomer esters at a high temperature and high pressure in the presence of a lower alcohol and a catalyst; and (3) hydrogenating the carboxylic acid esters distilled off in step (1) and the carboxylic acid esters obtained in step (2) either respectively or collectively to convert to 1,6-hexanediol.