摘要:
The present invention relates to N,N'-bis-(4-isocyanatocyclohexyl)urea obtained from the reaction with water of cyclohexane-1,4-diisocyanate having a high trans isomer content. This invention further relates to the process for preparing the N,N'-bis(4-isocyanatocyclohexyl)urea and to its use in the synthesis of polyurethanes.
摘要:
The present invention relates to a process for the preparation of a modified 1,5-naphthylene diisocyanate containing urea and biuret groups comprising reacting(a) 1,5-naphthylene diisocyanate in molten form with(b) a mixture comprising about 0.02 to about 0.5 mole of water per mole of 1,5-naphthylene diisocyanate and about 1 to about 10 parts for each part of water of an organic solvent.The present invention further relates to a process for the preparation of elastomeric moldings comprising reacting by the one-shot or prepolymer process at an isocyanate index of 70 to 130 a modified 1,5-naphthylene diisocyanate containing urea and biuret groups with compounds containing at least two isocyanate-reactive groups and having a molecular weight in the range from about 500 to about 10,000 and, optionally, organic compounds containing isocyanate-reactive groups and having a molecular weight in the range from 60 to 499.
摘要:
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.
摘要:
This invention relates to a process for preparing polyurethane urea elastomers by reacting (a) compounds containing at least two isocyanate-reactive groups and having a molecular weight in the range from about 400 to about 10,000; (b) polyisocyanates; and (c) aromatic diamines corresponding to the formula ##STR1## wherein R.sup.1 and R.sup.2 are independently hydrogen or alkyl.
摘要:
The present invention is directed to a process for the preparation of N,N'-bis-(3-aminophenyl)-ureas corresponding to formula (I) ##STR1## wherein R represents a linear or branched C.sub.1 -C.sub.6 alkyl group which is in the 2-, 4- and/or 6-position,characterized in that the corresponding phenylene diamines are reacted with urea in a molar ratio of greater than 2:1 in chlorobenzene as solvent.
摘要:
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.
摘要:
The present invention is directed to a process for the production of compact or cellular, elastomeric moldings having a compact skin based on polyurethane urea elastomers prepared from(a) organic polyisocyanates,(b) relatively high molecular weight polyhydroxyl or polyamino compounds containing at least two reactive hydrogen atoms,(c) diaminodiphenyl ureas as chain-extending agents and optionally,(d) catalysts,(e) small quantities of ethylene glycol,(f) other chain-extending agents and/or cross-linking agents,(g) blowing agents and(h) auxiliaries and/or additives, which is characterized in that the chain-extending agents (c) are diaminodiphenyl ureas corresponding to formula I ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be the same or different and represent hydrogen or a C.sub.1 -C.sub.6 alkyl radical and wherein the NH.sub.2 groups are in the m- and/or p-position to the urea group.The present invention is also directed to the RIM elastomers produced by this 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:
Polyamines are produced by hydrolyzing isocyanate compounds having an NCO content of from 0.5 to 40 wt. % with from 0.75 to 40 moles of water per equivalent of NCO groups in the presence of from 0.021 to 0.099 wt. % sodium hydroxide and at least 10 wt. % water-miscible polar organic solvent containing nitrile, ketone, sulfoxide or ether groups having a boiling point of from 56.degree. to 250.degree. C. The reaction mixture is maintained in a homogeneous phase. The reaction is carried out at 40.degree. to 170.degree. C. These polyamines are useful in the production of polyurethane(urea)s.
摘要:
Polyamines containing primary amino groups are made by a one-shot process for the hydrolysis of prepolymers containing isocyanate end groups and having an isocyanate content of from 0.5 to 40 weight % with 0.75 to 40 mol of water per equivalent of isocyanate groups in the presence of very small quantities of sodium hydroxide in certain organic, polar solvents. The compounds containing isocyanate groups used for this process are isocyanate prepolymers (preferably containing urethane groups). Hydrolysis according to this process leads directly to the polyamines with elimination of carbon dioxide. These polyamines may be isolated by the usual methods and the removal of the small quantities of catalyst may advantageously be omitted. These polyamines are useful for the preparation of polyurethane(urea)s.