摘要:
The invention relates to starting compounds which can be used for the preparation of polyurethanes and can be prepared by reaction of hydroxyl-containing oligomers of formaldehyde.
摘要:
The invention relates to starting compounds which can be used for the preparation of polyurethanes and can be prepared by reaction of hydroxyl-containing oligomers of formaldehyde.
摘要:
Catalyst suspensions for the ring-opening polymerization of alkylene oxides comprise a) at least one multimetal cyanide compound having a crystalline structure and a content of platelet-shaped particles of at least 30% by weight, based on the multimetal cyanide compound, and b) at least one organic complexing agent c) water and/or d) at least one polyether and/or e) at least one surface-active substance, with the proviso that at least component a) and at least two of the components b) to e) have to be present.
摘要:
A process for the preparation of polyether alcohols by reacting at least one alkylene oxide with at least one unsaturated starter having at least one active hydrogen atom per molecule under basic catalysis, that the alkoxylation is carried out in at least two stages, in stage (I) the alkoxylation of the starter or starters being carried out with not more than 10 mol of alkylene oxide per mole of starter with a catalyst concentration of not more than 0.0085 mol of basic catalyst per mole and in stage (II) and the optionally following stages, the alkoxylated starter or starters from stage (I) being reacted with further alkylene oxide at a catalyst concentration of at least 0.01 mol of basic catalyst per mole of starter.
摘要:
A process for the preparation of polyetherols, comprising the following steps: a) reaction of at least one starter compound with at least one alkylene oxide and a catalyst to give a crude polyetherol and b) removal of low molecular weight byproducts from the crude polyetherol from step a), wherein the crude polyetherol is treated with a stripping gas in a column having internals.
摘要:
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.
摘要:
The invention relates to a process for the continuous preparation of polyether alcohols by reaction of alkylene oxides with H-functional starter substances in the presence of DMC catalysts, which comprises, at the beginning of the process a) firstly placing initial charge material and DMC catalyst in a reactor, b) metering in alkylene oxide so that the metering rate which is maintained for continuous operation of the reactor is reached in a time of from 100 to 3 000 seconds, c) metering in starter substance during or after step b) so that the metering rate which is maintained for continuous operation of the reactor is reached in a time of from 5 to 500 seconds, d) after the fill level in the reactor which is desired for continuous operation of the reactor has been reached, taking product off continuously from the reactor while at the same time metering in starter substance and alkylene oxides in such an amount that the fill level in the reactor remains constant and metering in DMC catalyst so that the catalyst concentration necessary for continuous operation of the reactor is maintained in the reactor.
摘要:
In multimetal cyanide complexes, more than 30% by weight of the primary particles have a platelet-like habit, i.e. the length and width of the primary particles is at least three times the thickness of the particles.
摘要:
A process for the preparation of polyetherpolyols by reacting diols or polyols with ethylene oxide, propylene oxide, butylene oxide or a mixture thereof in the presence of a multimetal cyanide complex catalyst is proposed, the reaction being carried out in a stirred kettle reactor and the reaction mixture being circulated via an external heat exchanger by means of a pump.
摘要:
Water-soluble, hydrophobically associating copolymers which comprise new types of hydrophobically associating monomers. The monomers comprise an ethylenically unsaturated group and a polyether group with block structure comprising a hydrophilic polyalkylene oxide block which consists essentially of ethylene oxide groups, and a terminal, hydrophobic polyalkylene oxide block which consists of alkylene oxides with at least 4, preferably at least 5 carbon atoms.