Abstract: The invention relates to a composition based on alkoxysilane-functional polyurethane prepolymers suitable for a reactive hot-melt adhesive which is stable to storage at a high temperature but cures very rapidly under the action of moisture from the atmosphere or from the materials glued to one another and which is suitable for joining the most diverse materials. The invention also relates to the process for gluing the most diverse substrates using the reactive hot-melt adhesive according to the invention.

Abstract: The present invention relates to a process for the production of MDI fractions containing 2,4?-MDI, and in which the 2,2?-MDI component from the MDA production is largely removed from the isomer mixture. Highly reactive monomeric MDI products can be produced in this way. These MDI products are characterised in their processing by significantly reduced emissions of MDI monomers.

Abstract: The invention relates to moisture-curable adhesive or sealant compositions comprising a) prepolymers based on aliphatic polyisocyanates and having isocyanate contents of 2 to 20 wt. %, and b) bis(dimethylaminoethyl)ether as catalyst. The compositions exhibit good storability, processability can be adjusted within wide limits and also provide rapid through-hardening.

Abstract: Reactive polyurethane hotmelts comprising crystallizing polyesterpolyols based on fumaric acid and 1,6-hexanediol. These hotmelts exhibit good pressure-sensitive adhesive (PSA) properties over a very broad temperature range. The reactive polyurethane hotmelts are prepared by mixing a polyol mixture containing at least on crystallizing polyesterpolyol with an excess of polyisocyanates.

Abstract: The present invention relates to the use of compositions based on special isocyanate-terminated prepolymers as wood adhesives. The composition comprises at least one isocyanate-terminated prepolymer obtained by reacting at least one organic polyisocyanate and a mixture of at least two organic polyhydroxyl compounds containing at least 20 wt. % of fatty acid triglycerides containing hydroxyl groups, and at least 20 wt. % of polyethers having an average of at least two hydroxyl groups, and optionally auxiliary substances and additives.

Abstract: The invention relates to a composition based on alkoxysilane-functional polyurethane prepolymers suitable for a reactive hot-melt adhesive which is stable to storage at a high temperature but cures very rapidly under the action of moisture from the atmosphere or from the materials glued to one another and which is suitable for joining the most diverse materials. The invention also relates to the process for gluing the most diverse substrates using the reactive hot-melt adhesive according to the invention.

Abstract: The present invention relates to a process for bonding two or more wood substrates by using as the adhesive isocyanate-terminated prepolymers having an isocyanate content of 8 to 20 wt. % and containing the reaction product of a) at least one organic polyisocyanate with b) at least one organic polyhydroxyl compound containing the reaction products of i) organic polyisocyanates with ii) polyamines, hydrazines and/or hydrazides having primary and/or secondary amino groups dispersed in a iii) polyethers having at least two hydroxyl groups and a number average molecular weight of 500 to 12,000; and, the present invention also relates to the bonded substrates obtained by this process.

Abstract: The present invention relates to reactive compositions containing A) one or more blocked polyurethane prepolymers which have a content of blocked isocyanate groups (calculated as NCO) of 0.1 to 20 wt. % and are prepared from i) at least one aromatic, aliphatic, araliphatic and/or cycloaliphatic diisocyanate having a content of free NCO groups of 5 to 60 wt.

Abstract: The present invention relates to low-viscosity polyurethane prepolymers (PU prepolymers) based on 2,4?-MDI, to a process for preparing them and to their use.

Abstract: The present invention relates to a process for the production of MDI fractions containing 2,4?-MDI, and in which the 2,2?-MDI component from the MDA production is largely removed from the isomer mixture. Highly reactive monomeric MDI products can be produced in this way. These MDI products are characterised in their processing by significantly reduced emissions of MDI monomers.

Abstract: Reactive polyurethane hotmelts comprising crystallizing polyesterpolyols based on fumaric acid and 1,6-hexanediol. These hotmelts exhibit good pressure-sensitive adhesive (PSA) properties over a very broad temperature range. The reactive polyurethane hotmelts are prepared by mixing a polyol mixture containing at least on crystallizing polyesterpolyol with an excess of polyisocyanates.

Abstract: The present invention relates to a process for bonding two or more wood substrates by using as the adhesive isocyanate-terminated prepolymers having an isocyanate content of 8 to 20 wt.

Abstract: Hydroxyfunctional compounds suitable for use in the polyisocyanate polyaddition process are obtained from polyurethane and/or polyurethane polyurea waste by decomposition with an alcohol and subsequent reaction of the alcoholysis products to reduce their content of low molecular weight, sterically unhindered aromatic amines. In this process, polyurethane and/or polyurethane polyurea waste is first treated with a low molecular weight diol or polyol at a temperature of from about 160 to 260.degree. C. The resultant alcoholysis product may then either be further heated at a temperature lower than that used in the first step within the ranger of from about 50 to 180.degree. C. or reacted with a dialkyl carbonate and/or 1,3-dicarbonyl compound.

Abstract: The present invention relates to solvent-free two-component polyurethane adhesive systems with high initial strengths and low levels of migration derived from a select reactants comprising a hydroxyl polyester and an isocyanate containing prepolymer.

Abstract: Polyurethane elastomers with reduced gas permeability are prepared by reaction of:a) diisocyanates,b) compounds with a molecular weight of 500 to 10,000 having at least two hydrogen atoms that are reactive towards isocyanates,c) compounds with a molecular weight of 61 to 499 having at least two hydrogen atoms that are reactive towards isocyanates, and optionallyd) further auxiliaries and additives,characterized in thati) the ratio of the isocyanate groups in a) to the sum of the isocyanate-reactive groups in b) and c) is between 1:0.80 and 1:1.05 (isocyanate:isocyanate-reactive), andii) the compound b) contains 3 to 15% by wt.

Abstract: The present invention relates to a process for the production of hydroxyl-group-containing compounds suitable for the polyisocyanate polyaddition process from polyurea and/or polyurethane polyurea wastes by treating polyurea and/or polyurethane polyurea wastes with diols and/or polyols at temperatures from 160.degree. to 260.degree. C., the water present in the reaction vessel preferably being removed by distillation during the heating-up phase, characterized in that 1,3-dicarbonyl compounds are added to the reaction mixture before or during the reaction.

Abstract: A process for the decomposition of polyurethane plastic waste materials in which a compound containing at least two isocyanate-reactive hydrogen atoms (e.g., glycol) and polyurethane plastic, together with 2 to 20 times the amount of previously regenerated material, are treated in a mixing and comminution device.

Abstract: Compounds containing hydroxyl groups, which are suitable for the polyisocyanate addition polymerization process, are prepared from polyurethane-polyurea and/or polyurea waste materials. These compounds are produced by reacting a finely divided polyurethane-polyurea and/or polyurea waste material with a low molecular weight diol and/or polyol (and optionally a higher molecular weight polyol) and a low molecular weight urea and/or carbamic acid ester. This reaction may be carried in either one stage or two stages. In the two stage process, the waste material and diol/polyol are reacted in a first stage at a temperature of from about 100 to about 260.degree. C. In the second stage, the amine-containing alcoholysis product obtained in the first stage is reacted with a low molecular weight urea and/or carbamic acid ester.

Abstract: Aqueous solutions and dispersions of polyisocyanate polyaddition products containing 2 to 200 milliequivalents chemically incorporated carboxylate and/or sulfonate groups per 100 g solids and 0 to 25% by weight, based on solids, of incorporated ethylene oxide units arranged within terminal and/or lateral polyether chains, in the production of which primary and/or secondary monoamino compounds are usd, a process for their production and their use as adhesives.

Abstract: The invention relates to a process for bonding surfaces with isocyanate-containing prepolymers having an isocyanate group content of less than 1.8% by weight, based on the prepolymer, and an average molecular weight MW.sub.n of at least 4,500 in which (a) the prepolymers are prepared by the reaction of (i) polyester diols prepared from dodecanedioic acid and even-numbered alkane diols containing at least 6 carbon atoms and (ii) diisocyanates; (b) the prepolymer is applied as a hotmelt adhesive at a temperature of 80 to 160.degree. C. by spin-spraying onto at least one surface to be bonded; and (c) the treated surface is brought into intimate contact with a second surface to be bonded.