摘要:
A process for the preparation of urethanes. Urethanes having the general formula R.sub.1 (NHCOOR.sub.2).sub.n are reacted with an alcohol at a temperature of 120.degree. to 400.degree. C. in amounts such that, for every mol of the urethane, at least one mol of the alcohol is present. R.sub.1 is a radical obtained by removing the isocyanate groups from an n-functional organic isocyanate, which isocyanate has a boiling point greater than 100.degree. C. at atmospheric pressure. R.sub.2 is a radical obtained by removing the hydroxyl group from a monohydric alcohol which has a boiling point greater than 140.degree. C. at atmospheric pressure.
摘要:
A process for the preparation of N,O-disubstituted urethanes. Urea or polyurets, primary amines and alcohols are reacted at 120.degree.-350.degree. C. in the presence of N-substituted urethanes and/or N-mono- or N,N'-disubstituted ureas or polyureas. In a preferred embodiment, the reactants further include catalysts known to be useful in esterification of carboxylic acids. The urethanes produced in accordance with this process are particularly useful as starting materials for preparation of isocyanates.
摘要:
A process for the preparation of N,O-disubstituted urethanes. Primary amines and alcohols are reacted with organic compounds having carbonyl groups at 120.degree. to 350.degree. C. Suitable carbonyl-containing compounds include N-unsubstituted urethanes. N-mono-substituted, N,N'-disubstituted ureas, or polyureas may be used in combination with the N-unsubstituted urethane. The product urethanes are particularly suitable for the preparation of isocyanates.
摘要:
This disclosure relates to a process for the preparation of alkoxymethylisocyanates by reacting alkoxylmethyl tri-substituted ureas with isocyanates which have higher boiling points than the alkoxy methyl isocyanates produced. The process is also applicable to alkenoxy methyl tri-substituted ureas to make the corresponding isocyanates. Ureas of commercial purity may be used to obtain good yields of isocyanate when between about 0.03 and 0.2 mol of carbodiimide groups are present per mol of urea group. The carbodiimide containing compounds may also carry free isocyanate groups, in which case they should have a boiling point above that of the isocyanate product.
摘要:
A process for the preparation of 4-amino-1,2,4-triazol-5-one of the formula ##STR1## in which R is alkyl, comprising in a first step reacting phosgene with an acylhydrazide of the formula ##STR2## to produce an oxadiazolinone of the formula ##STR3## and in a second step reacting the oxadiazolinone with hydrazine hydrate.
摘要:
A carbamic acid ester corresponding to the formula R.sup.1 --NH--CO--OR.sup.2 is thermally cleaved to form isocyanate R.sup.1 --NCO and alcohol R.sup.2 --OH fractions. This cleavage is accomplished by boiling the carbamic acid ester, condensing the vapor given off in a first fractionation column, and condensing the vapor from the first fractionation column in a second fractionation column. The boiling of the carbamic acid ester is carried out in a manner such that the average dwell time in the reaction vessel is from 1 to 20 hours, the temperature is from 160.degree. to 260.degree. C. and the pressure is from 0.001 to 2 bar. The isocyanate fraction obtained by this cleavage process may be used as a starting material for a transurethanation reaction in which a lower boiling isocyanate R.sup.3 --NCO is produced. The radicals R.sup.1, R.sup.2, and R.sup.3 are defined herein.
摘要:
Fungicidal substituted aminophenyl carbamates of the formula ##STR1## in which X represents --CO--NR.sup.8 R.sup.9 ; --CO--OR.sup.9 ; --CO--SR.sup.9 ; --CO--R.sup.10 ; --SO.sub.2 R.sup.9 or hydrogen, in whichR.sup.8 represents hydrogen or alkyl,R.sup.9 represents optionally substituted aryl, optionally substituted aralkyl, optionally substituted alkyl, alkenyl, halogenoalkenyl, or in each case optionally substituted cycloalkyl, cycloalkenyl or cycloalkylalkyl, and R.sup.10 has the meaning of R.sup.9 or represents an optionally substituted heterocyclic ring,Y.sup.1 to Y.sup.4 are identical or different and represent hydrogen, halogen, nitro, cyano, alkyl, halogenoalkyl, alkoxy, halogenoalkoxy, alkylthio, alkylsulfonyl or halogenolkylthio,R.sup.1 to R.sup.7 are identical or different and represent hydrogen, alkyl, halogenoalkyl or alkoxyalkyl,n represents 0 or 1, andZ represents alkyl, halogenoalkyl or a ##STR2## radical
摘要:
.alpha.-(4-isocyanatophenoxy)-.psi.-(4-isocyanato-3-methyl-phenoxy)-alkanes and mixtures thereof with the corresponding methyl-free and/or dimethyl substituted diisocyanates are made by phosgenating the corresponding diamine(s). These diisocyanates do not form a precipitate when reacted with a polyol and produce polyurethanes having outstanding properties.
摘要:
The present invention is directed to 4,4'-diisocyanato phenylbenzylether, its method of production by reaction of the corresponding diamine with phosgene and the use of the diisocyanate for the production of polyisocyanate polyaddition products, preferably polyurethane plastics.
摘要:
Bis-(4-isocyanatophenoxy)-alkanes corresponding to the formula ##STR1## in which R represents a divalent, saturated aliphatic hydrocarbon radical having from 2 to 6 carbon atoms with at least two carbon atoms between the two ether oxygen atoms, andR' represents hydrogen or a methyl group with R' being the same on both rings,are produced by phosgenating the corresponding diamine or an adduct of the corresponding diamine. These diisocyanates are particularly useful in the production of isocyanate addition products having outstanding physical and mechanical properties.