摘要:
The present invention relates to a mixture comprising itaconic acid or an itaconic acid derivative and a primary amine of the formula (I) R—NH2 (I) where the molar ratio of primary amine to itaconic acid or the itaconic acid derivative is in the range from 0.5:1 to 20:1, wherein the mixture comprises 50 mole percent or less of 4-carboxypyrrolidones of the formula (II), derivatives of the 4-carboxypyrrolidones of the formula (II) and 4-carbamidopyrrolidones of the formula (III) based on the itaconic acid used or the itaconic acid derivative used and in which R is a linear or branched saturated aliphatic radical having 1 to 24 carbon atoms or a saturated cycloaliphatic radical having 3 to 24 carbon atoms.The invention further provides for the use of the inventive mixtures for preparing 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones, and also a process for preparing 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones.In addition, the present invention relates to mixtures comprising 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones and 1,3-alkylmethylpyrrolidines, where the proportion of 1,3-alkylmethylpyrrolidines is in the range from 10 to 10 000 ppm, and to mixtures comprising 1,3-alkylmethylpyrrolidone and 1,4-alkylmethylpyrrolidone, wherein the molar ratio of 1,3-alkylmethylpyrrolidone to 1,4-alkylmethylpyrrolidone is in the range from 1:1 to 10:1.
摘要:
A process for preparing an N-alkyllactam with improved color quality, wherein from 0.01 to 10% by weight of a C1-10-alcohol or a compound which releases from 0.01 to 10% by weight of a C1-10-alcohol is added to the N-alkyllactam.A mixture comprising at least 99.0% by weight of an N-alkyllactam and in the range from 100 to 5000 ppm by weight of a C1-10-alcohol or of an acetal, aminal or of an Orthoester which releases in the range from 100 to 5000 ppm by weight of a C1-10-alcohol.
摘要:
The present invention relates to a mixture comprising itaconic acid or an itaconic acid derivative and a primary amine of the formula (I) R—NH2 (I) where the molar ratio of primary amine to itaconic acid or the itaconic acid derivative is in the range from 0.5:1 to 20:1, wherein the mixture comprises 50 mole percent or less of 4-carboxypyrrolidones of the formula (II), derivatives of the 4-carboxypyrrolidones of the formula (II) and 4-carbamidopyrrolidones of the formula (III) based on the itaconic acid used or the itaconic acid derivative used and in which R is a linear or branched saturated aliphatic radical having 1 to 24 carbon atoms or a saturated cycloaliphatic radical having 3 to 24 carbon atoms. The invention further provides for the use of the inventive mixtures for preparing 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones, and also a process for preparing 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones.In addition, the present invention relates to mixtures comprising 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones and 1,3-alkylmethylpyrrolidines, where the proportion of 1,3-alkylmethylpyrrolidines is in the range from 10 to 10 000 ppm, and to mixtures comprising 1,3-alkylmethylpyrrolidone and 1,4-alkylmethylpyrrolidone, wherein the molar ratio of 1,3-alkylmethylpyrrolidone to 1,4-alkylmethylpyrrolidone is in the range from 1:1 to 10:1.
摘要:
A process for preparing an N-alkyllactam with improved color quality, wherein from 0.01 to 10% by weight of a C1-10-alcohol or a compound which releases from 0.01 to 10% by weight of a C1-10-alcohol is added to the N-alkyllactam.A mixture comprising at least 99.0% by weight of an N-alkyllactam and in the range from 100 to 5000 ppm by weight of a C1-10-alcohol or of an acetal, aminal or of an orthoester which releases in the range from 100 to 5000 ppm by weight of a C1-10-alcohol.
摘要:
A process for preparing an N-alkyllactam with improved color quality, wherein from 0.01 to 10% by weight of a C1-10-alcohol or a compound which releases from 0.01 to 10% by weight of a C1-10-alcohol is added to the N-alkyllactam.A mixture comprising at least 99.0% by weight of an N-alkyllactam and in the range from 100 to 5000 ppm by weight of a C1-10-alcohol or of an acetal, aminal or of an orthoester which releases in the range from 100 to 5000 ppm by weight of a C1-10-alcohol.
摘要:
A process for preparing 1,6-hexanediol from a carboxylic acid mixture which comprises adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols and is obtained as a by-product of the oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or oxygen-comprising gases by water extraction of the reaction mixture, by esterification and hydrogenation to hexanediol, which comprises a) the mono- and dicarboxylic acids present in the aqueous reaction mixture are reacted with a low molecular weight alcohol to give the corresponding carboxylic esters, b) the resulting esterification mixture is freed of excess alcohol and low boilers in a first distillation stage, c) in a second distillation stage, a separation is performed of the bottom product into an ester fraction essentially free of 1,4-cyclohexanediols and a fraction comprising at least the majority of the 1,4-cyclohexanediols, d) the ester fraction from (c) is catalytically hydrogenated and 1,6-hexanediol is obtained in a manner known per se by distilling the hydrogenation product, e) optionally the bottom product of stage c) is subjected to a further esterification reaction with a low molecular weight alcohol, the low molecular weight alcohol is distillatively removed on completion of the esterification reaction, then adipic diesters and 6-hydroxycaproic esters are substantially separated from 1,4-cyclohexanediols and high boilers in the remaining bottom stream by distillation and said adipic diesters and 6-hydroxycaproic esters are fed to stage c), which comprises performing at least one of the esterification reactions with a catalyst which comprises at least one element of groups 3-14, and adding a monomeric or oligomeric polyol with at least 3 hydroxyl functions after the esterification reaction. After step c) of the process according to the invention, in a third distillation stage, a stream comprising essentially methyl 6-hydroxycaproate can be at least partly removed and heated to temperatures above 200° C. under reduced pressure, which cyclizes 6-hydroxycaproic ester to caprolactone, and pure ε-caprolactone can be obtained from the cyclization product by distillation.
摘要:
The invention relates to an apparatus for separating a liquid substance mixture by distillation, a method for producing a tetrahydrofuran homopolymer and copolymer in which the oligomers in a liquid starting mixture containing oligomers are separated by distillation in such an apparatus, tetrahydrofuran homopolymers and copolymers which can be obtained using said method and have a narrow distribution of the relative molar mass, and the use thereof.
摘要:
The present invention relates to a process for preparing polytetrahydrofuran or tetrahydrofuran copolymers by polymerization of tetrahydrofuran in the presence of a telogen and/or a comonomer over a fixed bed of an acid catalyst, in which the temperature of the polymerization mixture increases in the direction of flow through the catalyst bed.
摘要:
The present invention provides a process for changing the given mean molecular weight Mn in the continuous preparation of polytetrahydrofuran or tetrahydrofuran copolymers, the mono- or diesters of polytetrahydrofuran or of tetrahydrofuran copolymers by polymerizing tetrahydrofuran in the presence of a telogen and/or of a comonomer over an acidic catalyst, wherein a) the molar ratio of telogen to tetrahydrofuran or to tetrahydrofuran and comonomer is changed, b) then the mean molecular weight of at least one sample is determined, c) until the mean molecular weight thus determined differs from the molecular weight to be achieved by the change, the already formed polytetrahydrofuran or the tetrahydrofuran copolymers, the mono- or diesters of polytetrahydrofuran or tetrahydrofuran copolymer is at least partly depolymerized over an acidic catalyst and d) the tetrahydrofuran recovered by depolymerization is recycled at least partly into the polymerization.
摘要:
The present invention provides a process for changing the given mean molecular weight Mn in the continuous preparation of polytetrahydrofuran or tetrahydrofuran copolymers, the mono- or diesters of polytetrahydrofuran or of tetrahydrofuran copolymers by polymerizing tetrahydrofuran in the presence of a telogen and/or of a comonomer over an acidic catalyst, wherein a) the molar ratio of telogen to tetrahydrofuran or to tetrahydrofuran and comonomer is changed, b) then the mean molecular weight of at least one sample is determined, c) until the mean molecular weight thus determined differs from the molecular weight to be achieved by the change, the already formed polytetrahydrofuran or the tetrahydrofuran copolymers, the mono- or diesters of polytetrahydrofuran or tetrahydrofuran copolymer is at least partly depolymerized over an acidic catalyst and d) the tetrahydrofuran recovered by depolymerization is recycled at least partly into the polymerization.