Abstract:
The invention relates to a method for producing (meth) acrylic acid esters of polyhydric alcohols by reacting (meth) acrylic acid and the corresponding polyhydric alcohols in the presence of at least one acid catalyst and, optionally, of at least one polymerization inhibitor and, optionally, in the presence of a solvent, whereby the polyhydric alcohol that is used has a content of bound formaldehyde of less than 500 ppm.
Abstract:
The invention relates to novel mixtures of polyalkoxylated trimethylolpropane (meth)acrylate of formula (I), wherein AO independently represents EO, PO, or BO for each AO, EO representing O-CH2-CH2-, PO independently representing O-CH2-CH(CH3)- or O-CH(CH3)-CH2-, BO independently representing O-CH2-CH(CH2-CH3)- or O-CH(CH2-CH3)-CH2-, p1 + p2 + p3 equals 28, 29, 30, 31, 32, 33, 34,35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74. or 75, and R1, R2, R3 independently represent H or CH3. Also disclosed are a simplified method for producing said ester mixtures and the use of the obtained reaction mixtures.
Abstract:
The invention relates to a method for processing (meth)acrylic acid in the presence of at least one stabilising agent. A mixture which contains the stabilising agent and is essentially devoid of (meth)acrylic acid and arising from the processing is introduced into a distilling device, and a low boiling flow which contains the stabilising agent and which is obtained from mixture is reintroduced into the preparation.
Abstract:
The invention relates to a column for the thermal treatment of mixtures containing at least one polymerisable compound. Said column comprises dual flow plates which are provided with openings, the diameter of each opening being constant inside a dual flow plate. The diameter of the openings of said dual flow plates decreases as the distance of the plates from the inlet of the mixture to be treated increases.
Abstract:
A method for stabilizing chemical compounds containing at least one ethylenically unsaturated bond in order to prevent undesirable radical polymerization, whereby a nitroxyl radical and a chemical compound containing chemically bonded phosphorus are added to an unsaturated compound existing in the form of a pure substance or constituent in a mixture.
Abstract:
The invention relates to a clamp (1) for releasably connecting a column plate (4) to a supporting ring (5) in a column, comprising a bolt (2) and a bolt bottom part (3) that is connected to said bolt (2), wherein the bolt bottom part (3) has at least one opening (8) through which a liquid located inside the column can flow out.
Abstract:
A process is disclosed for preparing N-substituted pyrazoles having the general formula (I), in which R1 stands for C¿1? to C12 alkyl or C7 to C20 phenylalkyl, and R?2, R3, R4¿ represent independently from each other hydrogen, C¿1? to C12 alkyl, C7 to C20 phenylalkyl or optionally substituted aryl residues, by reacting pyrazoles having the general formula (II), in which R?2, R3 and R4¿ have above-said meanings, with an alcohol having the general formula (III) R1-O-H, in which R1 has above-said meanings, at temperatures from 50 to 400 °C in the presence of a catalyst. The reaction of pyrazole (II) with compound (III) is carried out in a molar ratio from 0.001:1 to 1:1 in the liquid phase at a slight negative pressure up to an overpressure of 250 bars. Acids, their alkyl esters and/or their anhydrides are used as catalysts in a molar ratio from 0.0001:1 to 0.5:1 in relation to pyrazole (II).
Abstract:
A process for rectificatively separating liquids containing (meth)acrylic monomers in a rectification column is provided, in which a stream is withdrawn from the rectification column and recycled into the rectification column as a molecular oxygen-enriched liquid phase.
Abstract:
The present invention relates to novel (meth)acrylic esters of polyalkoxylated trimethylolpropane of the formula where AO is for each AO independently at each instance EO, PO or BO where EO is O-CH2-CH2- PO is independently at each instance O-CH2-CH(CH3)- or O-CH(CH3)-CH2- BO is independently at each instance O-CH2-CH(CH2-CH3)- or O-CH(CH2-CH3)-CH2- p1+p2+p3 is 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 or 75, R1, R2 and R3 are independently H or CH3, a simplified process for preparing these esters and the use of reaction mixtures thus obtainable.