Abstract:
The invention relates to a method for producing polyether alcohols by catalytically attaching ethylene oxide and propylene oxide to H-functional starting substances. Said method is characterized in that at least one multimetal cyanide compound is used as a catalyst, and a block comprised of an alkylene oxide having at least three carbon atoms in the molecule is attached to the chain end.
Abstract:
A process for preparing polyether polyols comprises A) preparing a polyether polyol precursor, B) preparing a suspension of a DMC catalyst in a polyol, C) activating the DMC catalyst by bringing it into contact with an alkylene oxide, giving an activated DMC catalyst suspension, D) adding the activated DMC catalyst suspension from step C) to the polyether polyol precursor, E) reacting the polyether polyol precursor with alkylene oxide and, if appropriate, an H-functional starter substance in the presence of the activated DMC catalyst.
Abstract:
The invention relates to a method for the production of low-emission polyurethane soft foams with reduced odour and reduced fogging by reaction of a) polyisocyanates with b) compounds with at least two hydrogen atoms reactive to isocyanate groups and c) blowing agents. The compounds with at least two hydrogen atoms reactive to isocyanate groups b) are represented by polyether alcohols, produced by the addition of alkylene oxides to compounds made from post-expanded raw materials using DMC catalysts.
Abstract:
The invention relates to a method for the continuous production of polyether alcohols by reacting alkene oxides with H-functional initiation substances in the presence of DMC catalysts. According to said method: a) a preliminary product and a DMC catalyst are first provided in a reactor, b) alkene oxide is added in such a way that the dosing speed, which is maintained for the continuous operation of the reactor, is reached within 100 to 3000 seconds, c) during or after step b) the initiation substance is added in such a way that the dosing speed, which is maintained for the continuous operation of the reactor, is reached within 5 to 500 seconds, d) once the contents of the reactor have reached the desired level for the continuous operation of said reactor, the product is continuously removed. The initiation substance and alkene oxide are added simultaneously in quantities that enable the level of the contents in the reactor to remain constant and the DMC catalyst is added in such a way that the catalyst concentration required for the continuous operation of the reactor is maintained.
Abstract:
The invention relates to a method for producing polyether alcohols by attaching alkylene oxides to H-functional initial substances, using multimetal cyanide compounds as catalysts, characterized by the fact that the multimetal cyanide compound is produced by a method comprising the following steps: a) a metal salt solution is added to a cyano-metal solution at a specific stirring rate e ranging between 0.05 and 10 W/l, preferably between 0.4 and 4W/l, and at a temperature ranging between 0 °C and 100 °C, preferably between 20 °C and 60 °C, during an addition time lasting between 5 and 120 minutes; b) the specific stirring rate e is reduced to between 0.03 and 0.8 W/l while a surface-active substance is added; c) the solution is heated to a maximum temperature of 100 °C, preferably between 55 °C and 75 °C, while being stirred at a specific stirring rate e ranging between 0.03 and 0.8 W/l; d) an additional amount of the metal salt solution is added and stirred at a specific stirring rate e of 0.03 to 0.8 W/l; e) the solid substance is dispersed, e.g. by stirring at an increased specific stirring rate e of > 0.7 W/l or by incorporating a transfer pump circuit comprising a corresponding pump or a dissolver, when the conductivity begins dropping; f) stirring at the specific stirring rate e used in step e) until the conductivity or the pH value remains stable; g) the multimetal cyanide compound is isolated and washed with water; and h) the catalyst is optionally dried.
Abstract:
The invention relates to a method for producing polyether alcohols by adding alkylene oxides to H-functional starting substances by means of multi-metal cyanide catalysts. The inventive method is characterized in that the multi-metal cyanide catalysts are microporous and have a specific surface of greater than 100 m2/g defined by nitrogen adsorption at 77K.
Abstract:
The invention relates to a method for producing multimetal cyanide compounds by converting a metallic salt with a cyanometallate compound. The inventive method comprises the steps: a) precipitating the multimetal cyanide compound by converting a metallic salt with a cyanometallate compound and b) recrystallising the multimetal cyanide compound precipitated in step a).
Abstract:
The invention relates to a method for producing polyetherols that involves the reaction of at least one alkylene oxide with at least one starter compound in the presence of at least one double metal cyanide compound to form a polyetherol and the treatment of the obtained polyetherol with steam or with an inert gas and steam. The invention also relates to the polyetherols themselves that can be obtained according to a method of the aforementioned type and to the use of these compounds for synthesizing polyurethanes.