| 摘要 |
Higher (meth)acrylates are prepared by reacting (meth)acrylic acid and the alcohol in the presence of at least one acidic catalyst and at least one polymerization inhibitor and in the presence of a solvent which forms an azeotropic mixture with water and distilling off and condensing the azeotropic mixture, the condensate separating into an aqueous phase and an organic phase, by a process in which a) the esterification is carried out in a reactor having a circulation evaporator and b) in the presence of at least 10% by weight, based on the reaction mixture, of solvent, and either c1) at least a part of the solvent, if required a part of the catalyst (mixture) and, if required, at least a part of the polymerization inhibitor (mixture) are initially taken in the esterification reactor and heated to the boiling point of the component having the lowest boiling point in the system and, as soon as the circulation is in operation, (meth)acrylic acid and alcohol and, if required, residual catalyst, polymerization inhibitor and solvent are metered in together or separately, or c2) at least a part of the solvent, if required a part of the catalyst (mixture), if required at least a part of the polymerization inhibitor (mixture) and at least a part of the alcohol are initially taken in the esterification reactor and heated to the boiling point of the component having the lowest boiling point in the system and, as soon as the circulation is in operation, (meth)acrylic acid and, if required, the remaining alcohol and, if required, residual catalyst, polymerization inhibitor and solvent are metered in together or separately, or c3) at least a part of the solvent, at least a part of the catalyst (mixture), at least a part of the polymerization inhibitor (mixture) and at least a part of the (meth)acrylic acid are initially taken in the esterification reactor and heated to the boiling point of the component having the lowest boiling point in the system and, as soon as the circulation is in operation, the alcohol and, if required, the remaining (meth)acrylic acid and, if required, residual catalyst, polymerization inhibitor and solvent are metered in together or separately, or c4) at least a part of the solvent, at least a part of the catalyst (mixture), at least a part of the polymerization inhibitor (mixture), at least a part of the alcohol and a part of the (meth)acrylic acid are initially taken in the esterification reactor and heated to the boiling point of the component having the lowest boiling point in the system and, as soon as the circulation is in operation, if required the remaining alcohol and the remaining (meth)acrylic acid and, if required, residual catalyst, polymerization inhibitor and solvent are metered in together or separately.
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