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7557242 Multistage continuous preparation of cycloaliphatic disocyanates  
Cycloaliphatic diisocyanates can be prepared continuously and phosgene-free by reacting at least one cycloaliphatic diamine with at least one carbonic acid derivative and at least one alcohol to...
7179935 Method for producing isocyanates  
A process for the preparation of isocyanates from carbamic esters.
6992214 Integrated process for the preparation of aromatic isocyanates and procedures for effecting the relative intermediate phases  
Integrated process for the preparation of aromatic isocyanates comprising: the reaction between an aromatic amine and an organiccarbonate in the presence of a catalyst selected from organic and...
6781010 Non-phosgene route to the manufacture of organic isocyanates  
A phosgene-free process for producing organic isocyanates reacts an organic fomamide with a diorganocarbonate and thermolyzing the reaction product to obtain the corresponding organic isocyanate....
6639101 Isocyanate production procedure  
The procedure consists of the catalytic thermal decomposition of a carbamate in the presence of natural or synthetic carbamates as catalysts. Isocyanates with high yields and high reaction speeds...
6251625 Process for preparing peptides and N-carbamoyl-protected peptides  
The invention concerns a process for the enzymatic preparation of protected di- and oligopeptides and the separation of the protective groups used. The process according to the invention enables...
5990345 Process for preparation of ethylenically unsaturated isocyanates  
A process for the preparation of ethylenically unsaturated isocyanates is described, which process comprises silylating an appropriate ethylenically unsaturated urethane precursor at the urethane...
5951911 Low viscosity ethylenically unsaturated polyurethanes containing allophanate groups  
The present invention relates to ethylenically unsaturated polyurethanes which are substantially free from isocyanate groups and have a) a content of β,γ-ethylenically unsaturated ether groups...
5914428 Process for preparation of isocyanate compounds  
An aliphatic diisocyanate compound is prepared in a high yield by reacting dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to produce a corresponding urethane...
5906998 Method for decomposing polymer containing urethane linkage and/or urealinkage  
In the decomposition of a polymer containing a urethane linkage and/or urea linkage in the presence of a decomposing agent, the amount of evolved carbon dioxide is measured and the decomposition...
5883291 Heat exchange media for the thermal cracking of carbamic acid esters  
Inert, thermally stable high-boiling solvents which have a defined boiling point or which boil over a narrow range are used as heat exchange media during thermal cracking of carbamic acid esters...
5789614 Process for preparation of aliphatic diisocyanate compounds  
An aliphatic diisocyante compound is prepared in a high yield by reacting dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to produce a corresponding urethene...
5731458 Process for thermally cracking carbamic acid esters  
This present invention relates to a process for thermally cracking carbamic acid esters into the corresponding isocyanate and hydroxyl compounds in the liquid phase, wherein the reaction proceeds...
5672736 Polyisocyanates containing allophanate groups  
The present invention relates to a process for preparing polyisocyanates containing allophanate groups by reacting compounds a), which i) contain urethane groups, but which are substantially...
5654474 Aromatic diisocyanate and method of producing the same  
Novel aromatic diisocyanate and a method of producing the same. The method comprises reacting a diamine compound with a chloroformate to produce an urethane intermediate, and then reacting the...
5648445 Liquid 1,3-phenylene diisocyanate, 1,1'-biphenyl diisocyanate and 1,1'-oxy-bis-(isocyanato-benzene)  
Allophanate-modified 1,3-phenylene diisocyanates or 1,1-biphenyl diisocyanates or 1,1'-oxy-bis-(isocyanato benzenes) which are storage stable liquid at 25° C. are made by reacting the diisocyanate...
5646328 Process for removing by-products from diurethanes  
Low-boiling by-products are removed from diurethanes prepared by a phosgene-free process by carrier vapor distillation using alcohol vapor, preferably the vapor of the basic alcohol found in the...
5633336 Polyamines containing urea groups and process for their preparation  
Low-viscosity (cyclo)-aliphatic polyamines containing urea groups and having more than two amino groups may be prepared by reacting (cyclo)aliphatic diamines with polyisocyanates containing...
5616784 Thermal cleavage of carbamic esters  
In a reactor for the thermal cleavage of mono- and polyfunctional carbamic esters into the corresponding isocyanates and the hydroxyl component in the liquid phase, the geometry of the reactor,...
5502244 Process for producing isocyanates  
Provided is a process for producing isocyanates from carbamic acid esters which comprises thermally decomposing carbamic acid esters in the presence of a catalyst containing at least one compound...
5457229 Process for preparing isocyanates from urethanes by a novel technique  
Urethanes are converted to isocyanates by reaction with a chloro-, bromo- or iodo-borane compound and a tertiary amine in a nonpolar solvent. With the preferred borane compound,...
5453536 Polycarbamates, process for preparing polycarbamates, and process for preparing polyisocyanates  
Polycarbamates of a polyisocyanate and secondary alcohols are disclosed. These carbamates are characterized in being readily pyrolyzed to form the corresponding polyisocyanate and alcohol with low...
5451697 Process for preparing isocyanates  
A process for preparing isocyanates comprising contacting carbon dioxide and a primary amine in the presence of an aprotic organic solvent and a base selected from the group consisting of a...
5449817 Process for the preparation of organic isocyanates  
The preparation of organic isocyanates of formula by the thermal decomposition of the corresponding carbamates in an inert solvent, is improved by thermally treating the dissolved carbamate in...
5386053 Multistep, continuous preparation of organic polyisocyanates  
A multistep process for the continuous preparation of organic polyisocyanates, preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic...
5386057 Process for the preparation of acyl isocyanates  
The invention concerns a process for the preparation of acyl isocyanates which consists of reacting oxalyl chloride with a salt selected from the group consisting of hydrohalides and sulphates of...
5360931 Continuous multi-stage process for the preparation of (cyclo) aliphatic diisocyanates  
A continuous multistage process for the preparation of (cyclo)aliphatic diisocyanates comprising a) condensing urea with a (cyclo)aliphatic diamine in the presence of an alcohol solvent to make a...
5344965 Preparation of a novel diisocyanate from norbornadiene  
Novel bicyclic alkyl dicarbamates are prepared from norbornadiene and other simple starting materials, and these are subsequently thermally cracked to novel diisocyanate norbornyl derivatives,...
5326903 Process for preparing isocyanates using sintered oxides  
A method for preparing isocyanates by the thermal decomposition of carbamates in the presence of a sintered oxide as catalyst under gaseous phase condition. The sintered oxide is composed of at...
5298651 Process for preparing isocyanates using phosphazine catalysts  
A process for preparing isocyanates comprising (a) contacting carbon dioxide and a primary amine in the presence of an aprotic organic solvent and a phosphazene compound or a mixture of a...
5284969 Process for the production of polyisocyanates  
A process for the continuous catalyst-free production of polyisocyanates by thermal decomposition of the N-substituted carbamic acid esters corresponding to the polyisocyanates, in which the...
5233010 Process for preparing isocyanate and carbamate ester products  
A process for preparing an isocyanate having at least two --NCO groups is provided which comprises preparing a substituted aromatic amine having at least two --NH 2 groups, recovering the...
5220069 Processes for the preparation of carbamates  
A process for preparing nitrogen-containing compounds which comprises contacting a carboxylated N-monosubstituted nitrogen-containing compound or a carboxylated N,N-disubstituted...
5210284 Continuous process for the preparation of isocyanates from urethanes  
Organic mono- or di-isocyanates are prepared by the decomposition of the corresponding urethanes, by means of a continuous process in which: (a) an urethane flow is continuously fed to a...
5196572 Process for producing xylylene diisocyanate  
Xylylene diisocyanate is produced in higher space-time yield with higher selectivity by thermal decomposition of xylylene dicarbamate as an urethane compound, i.e. by subjecting the urethane...
5166414 Process for producing isocyanate compound  
There is disclosed a process for producing an isocyanate compound from a formamide compound or an amine compound which comprises (a) the first reaction step of reacting a formamide compound with...
5126476 Process for the preparation of aryl-, heteroaryl-, or cycloalkyl-substituted alkyl urethanes and isocyanates  
A process for making aryl-, heteroaryl-, or cycloalkyl-substituted alkyl urethanes is disclosed. The urethanes are prepared by electrophilic carbamylation of aromatic compounds with alkylene...
5087739 Circulation process for the production of aliphatic and cycloaliphatic diisocyanates  
A circulation process for the production of (cyclo)aliphatic diisocyanates, in which the biscarbamate is produced from diamines, by-products from the thermal cracking, urea, and alcohol in the...
5043471 Process for the preparation of polyisocyanates  
The present invention relates to a process for the preparation of a polyisocyanate comprising (a) thermally decomposing in a tube reactor a solution of an N-substituted carbamic acid ester...
5039801 Thermal fragmentation of methylbenzylurea disastereomers or secondary amines and preparation of optically active secondary amines  
The invention provides an improved method for obtaining optically active amines, carbamates, and isocyanates by thermal fragmentation of optically active ureas through refluxing the ureas in C 3 ...
4879410 Preparation of primary aralkyl urethanes and ureas and isocyanates derived therefrom  
A process is disclosed for the preparation of aralkyl mono- and diurethanes or ureas by carbamylmethylation, or acid-catalyzed addition at a temperature of 40° C. to about 100° C. of formaldehyde...
4788329 Preparation of cyclohexyl mono- and diurethanes and isocyanates derived therefrom by addition of methylcarbamate to limonene, process and compositions  
A process is disclosed whereby mono- and diurethane cyclohexyl derivatives are obtained corresponding to the Lewis acid-catalyzed addition reaction of dipentene and methyl carbamate at a...
4748226 Method of preparation of novel 2-(alkoxymethyl)-pentane-1,5-diisocyanates, 2-(alkoxymethyl)-pentane-1,5-diurethanes, and 2-(alkoxymethyl)-pentane-1,5-dicarbamic acid chlorides and their uses  
This invention relates to novel 2-(alkoxymethyl) pentane-1,5-diisocyanates, 2-(alkoxymethyl)-pentane-1,5-diurethanes, and 2-(alkoxymethyl)-pentane 1,5-dicarbamic acid chlorides having the...
4692550 Continuous process for thermal splitting of carbamic acid esters  
N-monosubstituted carbamic acid esters are thermally split on a continuous basis in a tube reactor. The carbamic acid ester which is flowed down or passed over the inner wall of a tube reactor is...
4659845 Process for the production of N-methylcarbamates  
Process for the production of N-methylcarbamates: ##STR1## (wherein RO- is the radical of a substituted phenol or of a naphthol), wherein: in a first reaction step methylamine and diphenyl...
4572804 Preparation of unsaturated isocyanates  
Prepare α,β-unsaturated monoisocyanates by pyrolyzing α,β-saturated geminal bis-carbamates.
4570012 Urethanes from tertiary aralkyl diols  
Production of tertiary aralkyl urethanes, such as tetramethyl xylylene diurethanes, by addition of corresponding diols and carbamic acid esters at moderate temperatures and in the presence of acid...
4547322 Method for manufacture of diphenylmethane diisocyanates  
Manufacture of a diphenylmethane diisocyanate for an N-phenylcarbamate is economically accomplished in high yield with high selectivity by a method which comprises (A) a process of methylenation...
4530796 Process for the preparation of isocyanates through the thermal cleavage of urethanes  
A process for the pyrolysis of mono-, di-, and polyurethanes to the corresponding mono-, di-, and polyisocyanates wherein the urethane to be cleaved is heated under pressure and sprayed through a...
4514339 Process for preparing alkyl isocyanates  
Process for the production of alkyl isocyanates which can be defined by the general formula: R--NCO wherein R is an alkyl radical having from 1 to 4 carbon atoms by thermal decomposition of...
Matches 1 - 50 out of 94 1 2 >