Abstract: A process for producing a polycarbodiimide, comprising polymerizing a diisocyanate in the presence of a carbodiimidization catalyst in a reaction vessel in liquid phase at a temperature in the range of from 20 to 250° C., at a pressure in the range of from 20 to 800 mbar and in the presence of at least one inert gas, wherein the at least one inert gas is introduced into the liquid phase in the reaction vessel with a flow rate in the range of from 0.1 x/h to 100 x/h, x being the volume of the reaction vessel.

Abstract: A process for producing a polycarbodiimide, comprising polymerizing a diisocyanate in the presence of a carbodiimidization catalyst in a reaction vessel in liquid phase at a temperature in the range of from 20 to 250° C., at a pressure in the range of from 20 to 800 mbar and in the presence of at least one inert gas, wherein the at least one inert gas is introduced into the liquid phase in the reaction vessel with a flow rate in the range of from 0.1 x/h to 100 x/h, x being the volume of the reaction vessel.

Abstract: High-functionality polyisocyanates are prepared by a process which comprises (i) preparation of an addition product (A) which contains one group which is reactive toward isocyanate and at least two isocyanate groups by reacting (a) a diisocyanate or polyisocyanate I with (b1) compounds having at least three groups which are reactive toward isocyanate or (b2) compounds containing two groups which are reactive toward isocyanate or mixtures of (b1) and (b2), where at least one of the components (a) or (b) has functional groups having differing reactivities toward the functional groups of the other component and the reaction ratio is selected so that the addition product (A) contains an average of one group which is reactive toward isocyanate, (ii) if desired, intermolecular addition reaction of the addition product (A) to form a polyaddition product (P) containing an average of one group which is reactive toward isocyanate and an average of more than two isocyanate groups, and (iii) reaction of the addition

Abstract: Polyamides, oligomers thereof or mixtures thereof, if required with further reaction products, are prepared by reacting aminonitriles or dinitriles and diamines or a mixture containing aminonitrile, dinitrile and diamine, and, if required, further polyamide-forming monomers and/oligomers with water in a reactor (1) having a vertically oriented longitudinal axis, by a process in which, in the reactor (1), the reaction product is removed from the bottom and ammonia formed and any further low molecular weight compounds formed and water are taken off via the top (2), wherein the reactor (1) has at least two chambers (4) arranged one on top of the other in the longitudinal direction, the chambers (4) being separated from one another by liquid-tight trays (5), each chamber (4) being connected by a liquid overflow (6) to the chamber (4) directly underneath and a liquid product stream being taken off by the liquid overflow (6) of the lowermost chamber (4), the gas space (7) above the liquid level in each chambe

Abstract: Compounds of the formula 1 OCN—R1—NHCOX—R2—(Y)n??(1), where X is a covalent bond to R2 or is O, S or NR3, Y is a hydrogen atom or a free functional group and n is an integer from 1 to 20, can be used for functionalizing or modifying compounds or solid surfaces which have at least one group which is reactive toward isocyanate.

Abstract: The invention relates to polyurethane foams comprising (i) ethylenimine, polyethylenimine, polyvinylamine, polyvinylamine copolymers, carboxymethylated polyethylenimines, phosphonomethylated polyethylenimines, quarternized polyethylenimines and/or dithiocarbamatized polyethylenimines or (ii) alkali hydroxides and/or alkaline earth metal hydroxides or a mixture consisting of both (i) and (ii).

Abstract: The invention relates to polyurethane foams comprising

Abstract: The present invention relates to a mixture that contains (i) at least one isocyanate and (ii) at least one organic and/or inorganic acid anhydride.

Abstract: The invention relates to polyurethane foamed materials containing: (i) ethylene imine, polyethylene imine, polyvinylamine, polyvinylamine copolymers, carboxymethylated polyethylene imines, phosphonomethylated polyethylene imines, quarternized polyethylene imines and/or dithiocarbamatized polyethylene imines or; (ii) alkali hydroxides and/or alkaline-earth hydroxides or; a mixture consisting of both (i) and (ii).

Abstract: In a process for preparing linear oligourethanes and polyurethanes by reacting 1 mole of a) diisocyanate with 1 mole of b) a compound having two groups which are reactive toward isocyanates, the functional groups of a) and/or b) have differing reactivities toward the functional groups of the other reactant and the reaction conditions are selected so that in each case only particular functional groups of a) and b) react with one another.

Abstract: Polyisocyanates are prepared by a process which comprises (i) preparation of an addition product (A) which contains one group which is reactive toward isocyanate and one isocyanate group by reacting (a) a diisocyanate I with (b) compounds containing two groups which are reactive toward isocyanate, where at least one of the components (a) or (b) has functional groups having differing reactivities toward the functional groups of the other component, (ii) if desired, intermolecular addition reaction of the addition product (A) to form a polyaddition product (P) which contains one group which is reactive toward isocyanate and one isocyanate group and (iii) reaction of the addition product (A) and/or the polyaddition product (P) with a diisocyanate or polyisocyanate II which is different from diisocyanate I.

Abstract: In a process for preparing dendritic or highly branched polyurethanes by reacting diisocyanates and/or polyisocyanates with compounds containing at least two groups which are reactive toward isocyanates, at least one of the reactants contains functional groups having a different reactivity compared to the other reactant and the reaction conditions are selected so that only certain reactive groups react with one another in each reaction step.

Abstract: High-functionality polyisocyanates are prepared by a process which comprises

Abstract: In a process for preparing polyisocyanate polyaddition products by reacting isocyanates with compounds which are reactive toward isocyanates, in the presence or absence of blowing agents, catalysts, auxiliaries and/or additives, the reaction is carried out in the presence of (i) particles which have a size of <200 &mgr;m and a melting point in a range from 50 to 300° C., or in the presence of thermoset particles (ii) or in the presence of particles (i) and (ii).

Abstract: A crystalline multimetal cyanide complex of the formula (I) M1a[M2(CN)bL1c]d*e(M1fXg)*hL2′iH2O  (I) where M1 is at least one element from the group consisting of Zn(II), Fe(II), Co(III), Ni(II), Mn(II), Co(II), Sn(II).

Abstract: Polyisocyanates are prepared by a process which comprises

Abstract: Compounds of the formula 1

Abstract: In a process for preparing polyisocyanate polyaddition products by reacting isocyanates with compounds which are reactive toward isocyanates, in the presence or absence of blowing agents, catalysts, auxiliaries and/or additives, the reaction is carried out in the presence of (i) particles which have a size of <200 &mgr;m and a melting point in a range from 50 to 300° C., or in the presence of thermoset particles (ii) or in the presence of particles (i) and (ii).

Abstract: Compact, transparent polyisocyanate polyaddition products are produced in a process by reacting (a) isocyanates with (b) compounds reactive to isocyanates, if desired in the presence of (c) catalysts and (d) auxiliaries and/or additives, which comprises using as (b) compounds reactive to isocyanates a mixture (i) which has an average functionality of >3 and an average hydroxyl number of from 300 to 950 mg KOH/g.

Abstract: A process for the preparation of foamed plastics materials based on polyisocyanate polyaddition products by the reaction of isocyanates with isocyanate-reactive compounds in the presence of catalysts and, optionally, auxiliaries and/or additives, wherein i) isocyanates having isocyanurate and/or biuret structures are used, the isocyanate-reactive compounds used are ii) at least one diol and/or polyol having a molecular weight of from 400 to 8000 and containing at least 50% of primary hydroxyl groups based on all of the hydroxyl groups present in the compound, iii) at least one compound having at least one primary amine group, and diols and/or triols having molecular weights of less than 400 are optionally used as chain-extending and/or crosslinking agents, the reaction being carried out in the presence of iv) at least one tertiary amine acting as catalyst and/or v) at least one metal salt acting as catalyst and vi) water.