Abstract:
The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles by coating of water-absorbent polymer particles having a content of residual monomers in the range from 0.03 to 15% by weight with at least one surface-post-crosslinker and thermal surface-postcrosslinking at temperatures in the range from 100 to 180°C.
Abstract:
The invention provides a process for preparing polyether carbonate polyols by addition of alkylene oxides and carbon dioxide onto H-functional starter substances using DMC catalysts, characterized in that one or more starter substances are initially charged in the reactor and one or more starter substances are metered continuously into the reactor during the reaction.
Abstract:
The invention relates to a method for producing open-cell viscoelastic soft polyurethane foams based on renewable raw materials by reacting a) polyisocyanates with b) a polyol mixture composed of bi) compounds which contain at least two hydrogen atoms that react with isocyanate groups and which have a hydroxyl number ranging from 20 to 100mgKOH/g, and bii) compounds which contain at least two hydrogen atoms that react with isocyanate groups and which have a hydroxyl number ranging from 100 to 800 mgKOH/g, and biii) compounds which contain a minimum of one and a maximum of two hydrogen atoms that react with isocyanate groups and which have a hydroxyl number ranging from 100 to 800 mgKOH/g, and c) foaming agents. The inventive method is characterized in that each of component bi) and bii) contains at least one compound which comprises renewable raw materials or the reaction products thereof.
Abstract:
The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles comprising polymerizing droplets of a monomer solution, wherein water-absorbent polymer particles having an average particle diameter from 150 to 400 μηη, an amount of water-absorbent polymer particles having a particle size of less than 100 μηη of less than 5% by weight and an amount of water-absorbent polymer particles having a particle size of more than 500 μηη of less than 5% by weight are coated with at least one surface-postcrosslinker and thermal surface-postcrosslinked.
Abstract:
The invention relates to a method for producing polyetherpolyols by reacting diols or polyols with ethylene oxide, propylene oxide, butylene oxide or mixtures thereof in the presence of a multi-metal cyanide complex catalyst. The reaction is performed in stirred-tank reactor and the reaction mixture is circulated via an externally located heat exchanger, using a pump.
Abstract:
The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution in a surrounding heated gas phase in a reactor comprising a gas distributor (3), a reaction zone (5) and a fluidized bed (27), the gas leaving the reactor is treated in a condenser column (12) with an aqueous solution, the treated gas leaving the condenser column (12) is recycled at least partly to the fluidized bed (27), wherein the gas leaving the condenser column (12) comprises from 0.05 to 0.3 kg steam per kg dry gas and the steam content of the gas entering the gas distributor (3) is less than 80% of the steam content of the gas leaving the condenser column (12).