Abstract: The invention relates to aliphatic, cycloaliphatic or (cyclo)aliphatic diisocyanates, in addition to a method for their production.

Abstract: The present invention concerns a process for producing low-viscosity polyisocyanates or secondary products thereof, which carry activated, radiation-curable double bonds and can optionally also cure thermally, and low-viscosity polyisocyanate mixtures or secondary products thereof and their use in coating compounds.

Abstract: The pot life of an isocyanate formulation is controlled by including a chain extender having (a) at least two secondary amine groups, (b) no primary amine groups, and (c) a reactivity low enough that the chain extender will not react sufficiently with isocyanate groups present in the isocyanate formulation to increase the viscosity of the isocyanate formulation to more than 2000 mPa·s within 5 seconds in the isocyanate formulation.

Abstract: The present invention relates to (cyclo)aliphatic polyisocyanates which have a content of blocked and unblocked isocyanate groups (calculated a NCO) of 5 to 25 wt. %, in which at least 95% of the isocyanate groups are present in a form blocked with blocking agents, and which also contain 0.1 to 5.0 wt. % of amines having a structural unit corresponding to formula (I) The present invention also relates to the use of the blocked polyisocyanates according to the invention as crosslinking agents for organic polyhydroxyl compounds in 1C-PUR stoving lacquers, especially for automotive clearcoats and coil coating lacquers.

Abstract: Non-crystallizing N,N′-disubstituted N-(2-hydroxyalkyl)-ureas are used as hydrolysis protection agents in plastics containing ester groups. These disubstituted hydroxy-alkylureas impart excellent protection from hydrolysis to plastics containing ester groups and can be added directly to the plastics to be stabilized without the addition of special solvents.

Abstract: A process for the production of polymethylene polyphenyl polyisocyanates is disclosed. The process comprises phosgenating the corresponding polyamines in solution in an inert organic solvent, removing excess phosgene, and stripping the solvent, the improvement wherein at least 0.00015 percent by weight of hydrazine or hydrazine derivative per 100 percent by weight of polyamine are added to the polyamines at any time prior to the stripping step.

Abstract: (Cyclo)aliphatic polyisocyanate compositions which have a long shelf life, are obtainable by phosgene-free methods, preferably by thermal cleavage of (cyclo)aliphatic polycarbamates, and, for stabilization, contain at least one primary stabilizer (2a), preferably a sterically hindered phenol and/or an aromatic amine, or at least one secondary stabilizer (2b), preferably an organic phosphite and/or a thioether, or at least one acidic stabilizer (2c), preferably a carboxylic acid, an acyl chloride, an inorganic acid, an inorganic acid chloride and/or a diester of phosphoric acid, or a stabilizer system comprising at least 2 of the stabilizers (2a) to (2c), a process for the preparation of the (cyclo)aliphatic polyisocyanate compositions and their preferred use for the preparation of isocyanurate-containing polyisocyanates.

Abstract: Monofunctional or multifunctional isocyanates having the general formulaR--(N.dbd.C.dbd.O).sub.xwhere R is any organic remainder, x.gtoreq.1,or compounds which form such isocyanates under the influence of temperature are used in elastomeric compounds to be vulcanized as inhibitors for amines.

Abstract: A primary object of the invention is to provide a method of producing rigid polyurethane foams using 1,1-dichloro-1-fluoroethane (HCFC-141b) as the blowing agent while substantially avoiding the formation of decomposition products from HCFC-141b. The above object can be achieved by a method of producing rigid polyurethane foams which comprises reacting a polyol with an organic polyisocyanate for foaming in the presence of HCFC-141b and a stabilizer therefor and in the presence of an organic metal catalyst and/or an imidazole compound catalyst and by the thus-produced rigid polyurethane foams.

Abstract: A method for preventing the coloration of a diphenylmethane diisocyanate compound, which comprises adding, to the diphenylmethane diisocyanate compound, a hindered amine compound of the formula: ##STR1## wherein R.sup.1 and R.sup.3 are, the same or different, each a hydrogen atom or a C.sub.1 -C.sub.8 hydrocarbon group,R.sup.2 and R.sup.4 are, the same or different, each a C.sub.1 -C.sub.8 hydrocarbon group,R.sup.5 is a hydrogen atom, a methyl group, an ethyl group, a phenoxymethyl group or a phenyl group, andm is 0, 1 or 2,in an amount of 0.001 to 1.0 parts by weight per 100 parts by weight of the diphenylmethane diisocyanate compound.An excellent effect of preventing the coloration can be achieved only by the addition of a small amount of the hindered amine compound of the formula (I).

Abstract: Ingredients or precursor for synthesizing or formulating urethane polymers and prepolymers are dried by admixing therewith an enamine which reacts with the water. While some ingredients, such as polyols and solvents, can be individually dried in this manner, the enamine preferably is added after the polyol(s), solvent(s) and additives have been blended. When prepolymers having a relatively low free isocyanate content are to be synthesized or admixed with other ingredients, a sufficient amount of an isocyanate, preferably the same one used for synthesis, is added to react with amines liberated by the enamine-water reaction to produce an inert urea derivative.

Abstract: The invention relates to elimination of discoloration in polyurethanes, particularly thermoplastic polyurethanes, by the addition to the reaction mixture from 0.

Abstract: The present invention relates to a process for the production of aliphatic and/or cycloaliphatic diisocyanates which are color stable to heat, which is characterized in that a diisocyanate with aliphatically-and/or cycloaliphatically-bound isocyanate groups is heated in the presence of about 0.1 to 3% by weight, based on the diisocyanate, of at least one compound which is soluble in the diisocyanate and contains at least 3% by weight of structural units corresponding to the formula: ##STR1## for up to about 5 hours at a temperature of about 100.degree. to 220.degree. C. and the diisocyanate which has been treated in this way is subsequently purified by distillation.The present invention also relates to the use of the products of the present process for the production of modified polyisocyanates having improved coloration.

Abstract: Hydrazine is utilized for preventing side reactions during the preparation and storage of polyisocyanates partially blocked with hydroxy amines which are utilized for the introduction of basic functional groups into organic coating compositions which are deposited cathodically in an electrodeposition process. The inhibiting compound is used in the form of hydrazine hydrate at a level of from about 50 to 5000 ppm calculated on the amine used in the reaction.