摘要:
Disclosed is a method for jointly producing (i) formic acid (III); (ii) a carboxylic acid comprising at least two carbon atoms (II) and/or the derivatives thereof; and (iii) a carboxylic acid anhydride (VII). According to said method, (a) a formic acid ester (I) is transesterfied to formic acid (III) and the corresponding carboxylic acid ester (IV) by means of a carboxylic acid comprising at least two carbon atoms (II); (b) at least one portion of the carboxylic acid ester (IV) formed in step (a) is carbonylated in order to obtain the carboxylic acid anhydride (V); and (c) at least one portion of the carboxylic acid anhydride (V) formed in step (b) is further dehydrated by means of a carboxylic acid (VI) so as to form a carboxylic acid anhydride (VII) and the carboxylic acid (II).
摘要:
Disclosed is a process for postcrosslinking a water absorbing polymer by the polymer being treated with at least one postcrosslinker and postcrosslinked and dried during or after the treatment by raising the temperature, the at least one postcrosslinker being a cyclic carbamate or a cyclic urea, wherein the cyclic carbamate or the cyclic urea was obtained by reacting respectively an aminoalcohol or a diamine with a cyclic carbonate.
摘要:
A process for postcrosslinking a water-absorbing polymer comprises said polymer being treated with a postcrosslinker and, during or after said treating, being postcrosslinked and dried by temperature elevation, said postcrosslinker being a compound of the formula I where R1, R2, R3, R4, R5, R6, R7, R8 and R9 are each independently hydrogen, C1-C12-alkyl, C2-C12-alkenyl or C6-C12-aryl, wherein C1-C12-alkyl, C2-C12-alkenyl or C6-C12-aryl may be halogen substituted. The liquid-absorbing polymers are useful in hygiene articles and packaging materials.
摘要:
The present invention relates to a process for preparing compounds of the formula (I) by reacting compounds of the formula (II) with thiolates (RS)nM.The present invention further relates to a process for preparing compounds of the formula (II) from γ-butyrolactone.
摘要:
Disclosed is a process for postcrosslinking a water absorbing polymer by the polymer being treated with at least one postcrosslinker and postcrosslinked and dried during or after the treatment by raising the temperature, the at least one postcrosslinker being a cyclic carbamate or a cyclic urea, wherein the cyclic carbamate or the cyclic urea was obtained by reacting respectively an aminoalcohol or a diamine with a cyclic carbonate.
摘要:
Processes are described comprising: (i) providing a reactant comprising 1,2-dichloroethane; and (ii) reacting the reactant with ammonia to form a reaction product comprising one or more ethylene amines and hydrogen chloride, wherein the reaction is carried out in the presence of an organic, nitrogen- or phosphorus-containing compound which reacts with the hydrogen chloride to form an ionic liquid.
摘要:
The invention relates to a dispersion or solution of a polymer in water, organic solvents or mixtures thereof. The invention is characterised in that the polymer contains at least 0.001 mols of 3,4 dihydroxyphenyl groups (calculated at 109 g/mol) for 100 g polymer.
摘要:
The present invention relates to a process for preparing quaternary phosphonium salts by reacting a ternary phosphine with an optionally substituted, saturated or monounsaturated or polyunsaturated electrophile having from 3 to 25 carbon atoms in ternary solvent mixtures.
摘要:
The present invention relates to a process for preparing vitamin A acetate by reacting β-vinylionol with triphenylphosphine in the presence of sulfuric acid in a solvent mixture consisting of 60 to 80% by weight methanol, 10 to 20% by weight water and 10 to 20% by weight aliphatic, cyclic or aromatic hydrocarbons having 5 to 8 carbon atoms to give β-ionylideneethyltriphenylphosphonium salts and subsequent Wittig reaction with 4-acetoxy-2-methylbut-2-enal.
摘要:
A process for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of an n-butene-containing hydrocarbon stream by means of oxygen-containing gases in a shell-and-tube reactor having two successive reaction zones, where the first, feed-side reaction zone contains at least one catalyst which is suitable for the oxydehydrogenation of n-butenes to 1,3-butadiene and the second, product-side reaction zone contains at least one catalyst which is suitable for the oxidation of 1,3-butadiene to maleic anhydride, is carried out using a shell-and-tube reactor which has at least one heat transfer medium circuit in the region of the first, feed-side reaction zone and at least one further heat transfer medium circuit in the region of the second, product-side reaction zone.