摘要:
Storage stable heterogeneous systems which may be processed at low temperatures to form polyurethanes are made by mixing a specific quantity of a high molecular weight polyhydroxyl compound with a specified quantity of a 4,4'-diphenyl methane uret dione diisocyanate corresponding to a specified formula or a corresponding modified diisocyanate. A lead and/or tin catalyst is also included.
摘要:
The invention relates to polyisocyanates corresponding to the following general formula: ##STR1## wherein X represents a radical of the type obtained by removing the more reactive isocyanate group from an organic diisocyanate containing isocyanate groups of different reactivity; andY represents a chlorine, bromine, C.sub.1 -C.sub.8 alkyl, C.sub.1 -C.sub.8 alkoxy, C.sub.6 -C.sub.10 aryl, C.sub.6 -C.sub.10 aroxy radical or a radical corresponding to the general formula: --NH--CO--NH--X.These polyisocyanates are produced by reacting polyamines corresponding toX as shown above;Y represents --NH--CO--NH--X.
摘要:
The instant invention relates to a process for the production of isocyanates in which tert.-alkyl urethanes are reacted with phosgene and to isocyanatoaryl sulphonic acid esters obtainable for the first time by this process.
摘要:
The present invention thus relates to new compounds containing aminophenoxy end groups corresponding to the formula ##STR1## wherein R.sub.1 denotes an n-valent group as obtained by the removal of hydroxyl groups from an n-valent polyhydroxyl compound having a molecular weight of about 400 to about 12,000, preferably 400 to about 6,000,R.sub.2 denotes an integer with a value from 2 to 8, preferably from 2 to 4.The present invention also relates to a process for the preparation of these compounds containing aminophenoxy end groups by reacting a polyhydroxyl compound with a halogenated nitrobenzene in the presence of an alkaline compound and subsequently hydrogenating the nitrophenoxy adducts obtained to form the corresponding aminophenoxy adducts.Lastly, the present invention relates to the use of the compounds containing aminophenoxy end groups as starting components for the production of polyurethane plastics by the isocyanate polyaddition process.
摘要:
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.
摘要:
The invention is directed to suspensions of isocyanato ureas in isocyanate prepolymers; to a process for their production by reacting mixtures of aromatic diisocyanates containing isocyanate groups of different reactivities and prepolymers containing terminal isocyanate groups, with water; and to the use of the suspensions as synthesis components in the production of polyurethane plastics.
摘要:
A polyurethane is made by reacting a polyisocyanate with a compound having at least two isocyanate-reactive hydrogen atoms and having a molecular weight of from 400 to 10,000 in the presence of a catalyst. The catalyst employed is a cyclic N-hydroxyalkyl-substituted compound containing an amidine group. Polyurethanes made in accordance with this process are useful as shoe soles, upholstery material, sound insulating materials, coating compositions, packaging materials and mattresses.
摘要:
This invention relates to new diisocyanates containing urea groups which are liquid at room temperature or can be liquefied by heating to a temperature of up to 80.degree. C. These novel diisocyanates may be in the form of solutions in isocyanate prepolymers. The invention also is directed to a process for preparation of these new diisocyanates by the reaction of special diisocyanate starting materials and water and to their use as components for the production of polyurethanes.
摘要:
The instant invention is directed to polyurethane plastics which may be cellular, produced by reaction of polyisocyanates with relatively high molecular weight polyhydroxyl compounds and, optionally, low molecular weight polyhydroxyl compounds, and diamines, said polyurethane plastic containing structural units corresponding to the general formula ##STR1## in which R' represents a straight or branched divalent aliphatic, cycloaliphatic or aromatic radicals containing from 2 to 20 carbon atoms andR" represents hydrogen, a straight or branched alkyl radical containing from 1 to 6 carbon atoms, an aryl radical containing from 6 to 15 carbon atoms, a cycloalkyl radical containing from 4 to 12 carbon atoms, halogen, --NO.sub.2, --CN, --OR'" or a radical ##STR2## where R"' represents a straight or branched alkyl radical containing from 1 to 6 carbon atoms.
摘要:
The instant invention is directed to a process for the production of weather-resistant rigid molded foams based on polyurethanes having a dimensional stability under heat according to DIN 53 432 of at least 70.degree. C. and a compact surface, a cellular core and an integral density distribution throughout the cross-section of the moldings, comprising foaming a foamable reaction mixture of polyisocyanates, polyhydroxyl compounds, blowing agents and, optionally, other isocyanate-reactive compounds, activators and other auxiliaries in a closed mold under the conditions of in-mold foaming, the improvement wherein the polyisocyanates used are reaction products containing isocyanate groups and urethane groups, said reaction products formed by reacting diisocyanates containing at least one cycloaliphatically bound isocyanate group and no more than one aliphatically bound isocyanate group with sub-stoichiometric quantities of organic polyhydroxyl compounds.