Abstract: An ankle-joint orthosis which comprises a U-shaped supporting yoke consisting of flexible material, the arms of which meet in a web below the foot, extend above the malleoli and are held together in their end region by a fastening strap wrapping round the leg. The outer arm is taken upwards at the side in front of its malleolus and the inner arm is taken up opposite the outer arm, in front of the Achilles tendon. The arms are taken towards the web as far as a position in front of the heel and extend upwards towards their ends in such a manner that they rise upwards laterally beside the edges of the shinbone, substantially parallel to these. Fitted in the lower region of the arms is a supporting strap, particularly a self-gripping strap, which extends from the one arm, over the instep obliquely upwards to the other arm on which it can be fixed, engages round the Achilles tendon above the malleolus and, crossing over itself on the instep, ends in a holding member on the other arm.

Abstract: Polyurethanes containing uretdione rings are produced by reacting a polyisocyanate containing a uretdione ring with a relatively high molecular weight dihydroxyl compound in the presence of a bismuth salt of an organic carboxylic acid and a low molecular weight aromatic diamine. The low molecular weight aromatic diamine is used in a quantity which is 5 to 10 times the quantity of bismuth salt used. These solid polyurethanes are formed in relatively short reaction times and possess outstanding mechanical properties.

Abstract: The present invention relates to a process for the production of polyurethane urea elastomers from(a) NCO-terminated prepolymers based on polyisocyanates and polyethers having a molecular weight of 400 to about 10,000 and an ethylene oxide content of about 10 to 60 mole-% and(b) solid diaminodiphenyl ureas corresponding to the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 may be the same or different and represent hydrogen or C.sub.1 -C.sub.6 alkyl radicals and wherein the amino groups are in the m-and/or p-position to the urea group,characterized in that the NCO prepolymers are reacted with the diaminodiphenyl ureas in powder-form in a heterogeneous phase at temperatures of about 5.degree. to 40.degree. C.The present invention is also directed to the polyurethane urea elastomers prepared by this process.

Abstract: The present invention is directed to a process for the production of a polyurethane urea elastomer which comprises preparing a heterogeneous mixture of(a) a diaminodiphenylurea corresponding to the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, represent hydrogen or a C.sub.1 -C.sub.6 alkyl radical and wherein the amino groups are in the meta and/or para position to the urea group and(b) polyisocyanates and NH.sub.2 -or OH-groups containing compounds or a NCO-terminated prepolymer prepared from a polyisocyanate and a polyhydroxyl compound having a molecular weight of 400 to about 10,000, and subsequently reacting the heterogeneous system to form a polyurethane urea elastomer by heating the mixture to a temperature below the melting point of said diaminodiphenylurea.The present invention is also directed to heterogeneous reaction mixtures based on the above diaminodiphenylureas suspended in the above NCO-terminated prepolymers.

Abstract: High molecular weight amines having reduced low molecular weight amine contents are obtained by reacting a mixture of (1) a high molecular weight amine and (2) a low molecular weight amine with (3) an isocyanate in quantities such that from 0.5 to 10 equivalents of isocyanate are present for each equivalent of low molecular weight amine. The product of high molecular weight amines is particularly useful in the production of isocyanate addition products such as polyurethane plastics and foams.

Abstract: This invention relates to N,N'-bis(5-isocyanatonaphthyl)urea and a process for its preparation by hydrolysis of naphthalene-1,5-diisocyanate. This invention also relates to a method for preparing a polyurethane or polyurea comprising reacting N,N'-bis(5-isocyanatonaphthyl)urea with an NCO-reactive compound.

Abstract: The present invention relates to a process for the production of storable thermosetting polyurethane-polyurea compositions wherein a storable isocyanate component stabilized by a surface coating and a polyol and/or polyamine component are separately prepared. A one-component polyurethane-polyurea reactive mixture is formed by mixing just before the intended use the separate components under mild shear forces at a temperature below the thickening temperature of the final reactive mixture.

Abstract: The present invention is directed to a process for the production of a thixotropic agent by reacting a polyisocyanate containing a uretdione group with a polybasic carboxylic acid containing at least one carboxyl group and, optionally, OH groups. The present invention is also directed to thixotropic high molecular weight polyols containing the above thixotropic agent. Finally, the present invention is directed to storable, reactive polyurethane systems comprising thixotropic polyols and polyisocyanates which are essentially unreactive with the polyols at room temperature.

Abstract: A composite plastic molding made up of a plastic foam and having a polyurethane skin is made by heating a reactive one-component system to form a polyurethane skin and then joining the polyurethane skin to the plastic foam. The one-component system is composed of a finely divided polyisocyanate in which from 0.1 to 25 equivalent percent of the isocyanate groups have been deactivated, a polyamine and/or polyol having a molecular weight of from 400 to 8000 and optionally a chain extending agent, a catalyst and known auxiliaries and additives.

Abstract: Polyurethanes containing uretdione rings are produced by reacting a polyisocyanate containing a uretdione ring with a relatively high molecular weight dihydroxyl compound in the presence of a bismuth salt of an organic carboxylic acid and a low molecular weight aromatic diamine. The low molecular weight aromatic diamine is used in a quantity which is 5 to 10 times the quantity of bismuth salt used. These solid polyurethanes are formed in relatively short reaction times and possess outstanding mechanical properties.

Abstract: The invention relates to a process for the in situ production of dispersions or solutions of urea group-containing aromatic isocyanates by the low temperature reaction of aromatic diisocyanates and/or polyisocyanates (the NCO groups of which preferably exhibit different reactivities) with from 0.15 to 0.4 mols of water per NCO equivalent in relatively high molecular weight polyols and in the presence of catalysts accelerating the NCO/water reaction. Such catalysts are preferably selected from peralkylaminoalkyl ethers, peralkylamino-polyalkylene ethers and/or peralkyl-polyalkylene-polyamines. The present invention also relates to the resulting metastable solutions or dispersions and to the use thereof, optionally with the further addition of relatively high and low molecular weight compounds having hydroxyl, amino or hydrazide groups and with the optional addition of other polyisocyanates in polyurethane-forming ratios for the production of polyurethanes.

Abstract: The present invention is directed to a process for the preparation of finely divided solid polyisocyanates containing urea groups by reacting organic polyisocyanates which are free from urea groups with water in an aqueous emulsion, characterized in that the reaction is carried out in the presence of an emulsion- and dispersion-stabilizing compound.

Abstract: The present invention relates to a process for the dimerization of 4,4'-diisocyanatodiphenylmethane from emulsion in apolar solvents with the formation of complexes and to the complexes obtainable for the first time by this process. The complexes consist of one mol of low molecular weight 4,4'-diisocyanato-diphenylmethane-uretdione or its low oligomers corresponding to the idealized formula (I) ##STR1## (n=0 to 0.5, where n is the average degree of oligomerization of the dimer) and 2 to 3 mol of 4,4'-diisocyanatodiphenylmethane (MDI) ##STR2## In the process according to the invention, 4,4'-diisocyanatodiphenylmethane (II) in the molten form is emulsified in apolar solvents. Dimerization is started in the presence of conventional dimerization catalysts at temperatures above the melting point of MDI, preferably up to an upper temperature limit of 50.degree. to 60.degree. C. The temperature is then lowered to <40.degree. C. If desired, dimerization can be stopped when an isocyanate content of from 22.4 to 26.

Abstract: The present invention relates to cold setting compositions of (A) suspensions of solid polyisocyanates with retarded reactivity in aliphatic polyamines, and which are stable under storage due to a polyadduct covering, and (B) polyols and/or water. The activation of the composition is caused by the polyol or water. Additional activating materials can also be added for hardening. Such compositions, which already harden at ambient temperature, are stable under storage, have a long potlife for processing and, in relation to the potlife, have a very short hardening time to the final reaction product.

Abstract: The present invention is directed to a process for the production of urea group-containing, finely divided solid polyisocyanates by emulsifying or suspending a urea group-free organic polyisoycanate in an excess of water so that said organic polyisocyanate amounts to about 1 to 65% by weight of the reaction mixture, said water containing about 0.01 to 5% by weight, based on the aqueous phase, of a protective colloid and reacting the organic polyisocyanate with water to yeild a urea group-containing polyisocyanate.

Abstract: This invention relates to the production of polymer-coated, finely divided polyisocyanates by mixing(A) solid, finely divided polyisocyanates (preferably dimeric diisocyanates or urea diisocyanates) with(B) polyisocyanates differing in composition from those mentioned under (A) (preferably (cyclo) aliphatic polyisocyanates, such as biuretized diisocyanates or trimers or NCO-prepolymers),in quantities of from 0.05 to 50 parts by weight, and preferably in quantities of from 0.2 to 25 parts by weight, of (B) per 100 parts by weight of (A). The solid polyisocyanate particles surface-modified by covering with polyisocyanates (B) and then reacted with(D) isocyanate-reactive compounds containing reactive hydrogen atoms or with compounds free from active hydrogen atoms which form polymers with isocyanates in sub-equivalent to substantially equivalent quantities (preferably 0.5 to 1.

Abstract: This invention relates to a process for the production of solid polyamines stabilized by a polyadduct covering and showing retarded reactivity comprising reacting(1) one or more solid organic polyamines in particulate form, said polyamines containing at least two primary and/or secondary amino groups and having melting points above 50.degree. C., and(2) from 0.1 to 25 equivalent % of isocyanate per amine equivalent of a water insoluble, difunctional and/or higher functional polyisocyanate,said reaction being conducted at a temperature below the melting point of said solid polyamine, and being conducted in the presence of(3) a liquid medium selected from the group consisting of(a) organic compounds containing two or more hydroxy groups and having molecular weights of from 62 to 10,000,(b) plasticizers,(c) water, and(d) mixtures thereofto form a suspension of polyadduct-covered stabilized polyamines in the liquid medium.

Abstract: The invention relates to novel compositions for coating purposes comprising(A) polyvinyl plastisols,(B) surface modified, finely divided, stabilized polyisocyanates with retarded reactivity, in which 0.1 to 25 equivalents-% of the isocyanate groups of the unstabilized polyisocyanate have been deactivated on the surface, preferably by a reaction with polyamines, hydrazine, alkylhydrazines, polyhydrazide compounds and/or selected amidine and/or guanidine compounds; and(C) plasticizers and/or lightly branched, relatively high molecular weight polyhydroxyl compounds having melting points below 60.degree. C. and compatible with PVC plastisol.The invention also relates to the use of these storage stable but heat curable mixtures as primers for PVC coatings on plastics, foils, textile sheet products or filaments and as primer coats for flocking.

Abstract: The present invention is directed to a process for the production of suspensions of finely-divided polyisocyanates which are obtainable by the surface reaction with from 0.1 to 25 equivalent percent of reactive group per NCO of stabilizers in relatively high molecular weight polyols and/or relatively high molecular weight polyamines having molecular weights from 400 to 6,000 optionally with addition of lower molecular weight polyols and/or aromatic amines having molecular weights of from 60 to 399, which are characterized in that unreacted quantities of stabilizers in the suspension are subsequently partially or completely deactivated by addition of substances having an acylating and/or neutralizing and/or alkylating effect and/or adsorbing effect as "deactivators". In particular, mono- and/or polyisocyanates are used as "deactivators".

Abstract: The invention relates to a process for the in situ production of dispersions or solutions of urea group-containing aromatic isocyanates by the low temperature reaction of aromatic diisocyanates and/or polyisocyanates (the NCO groups of which preferably exhibit different reactivities) with from 0.15 to 0.4 mols of water per NCO equivalent in relatively high molecular weight polyols and in the presence of catalysts accelerating the NCO/water reaction. Such catalysts are preferably selected from peralkylaminoalkyl ethers, peralkylamino-polyalkylene ethers and/or peralkyl-polyalkylene-polyamines. The present invention also relates to the resulting metastable solutions or dispersions and to the use thereof, optionally with the further addition of relatively high and low molecular weight compounds having hydroxyl, amino or hydrazide groups and with the optional addition of other polyisocyanates in polyurethane-forming ratios for the production of polyurethanes.