摘要:
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 (urethane cracking).
摘要:
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 as a reactive rectification in the stripping zone of a column and in an inert, high-boiling solvent, which acts as a buffer to keep the reaction away from the evaporator region of the column.
摘要:
A new process for the production of high purity (cyclo)aliphatic diurethanes from (cyclo)aliphatic diamines, alcohols and urea in a multistep reaction in which (1) urea is reacted with alcohol with elimination of ammonia, (2) diamine is then introduced into the reaction mixture, optionally in the form of a solution in alcohol, and reacted with continuous release of ammonia and (3) the reaction mixture is freed from volatile components by distillation. The diurethanes produced by this process are useful as starting materials for the production of the corresponding diisocyanates by thermal urethane cleavage.
摘要:
The present invention relates to a process for the production of aqueous dispersions which form powder coatings at room temperature, have an average particle size of 0.1 to 10 .mu.m, contain polyols and blocked polyisocyanate crosslinking agents, and, after stoving, yield coatings with improved water and solvent resistance, in particular on metallic substrates.
摘要:
The present invention relates to a process for the production of 1-amino-1-methyl-3(4)-aminomethylcyclohexane bya) simultaneously reacting 4(5)-aminomethyl-1-methylcyclohexene (CMA), hydrocyanic acid and aqueous sulphuric acid at temperatures of 60.degree. C. to 120.degree. C., preferably 80.degree. C. to 120.degree. C. to form 1-formamido-1-methyl-3(4)-aminomethylcyclohexane (FMA) in a first stage,b) adding water and hydrolyzing 1-formamido-1-methyl-3 (4)-aminomethylcyclohexane (FMA) and unreacted hydrocyanic acid in a second stage andc) adding a base and isolating 1-amino-1-methyl-3 (4)-aminomethylcyclohexane (AMCA) by extraction from the reaction mixture obtained in the second stage of the reaction, optionally after removing of formic acid.
摘要:
A process for the removal of at least one volatile compound from a reactive or unreactive mixture of substances with the aid of at least one micro-evaporator, the micro-evaporator displaying channels for carrying the mixture of substances having a hydraulic diameter of 5 to 1000 μm and a specific evaporator surface area of at least 103 m2/m3.
摘要翻译:借助于至少一个微型蒸发器从物质的反应性或非反应性物质中除去至少一种挥发性化合物的方法,所述微型蒸发器显示用于承载水力直径为5至1000的物质混合物的通道 妈妈和特定的蒸发器表面积至少为10 -3 m 2 / m 3。
摘要:
The present invention relates to a process for the preparation of 1-amino-1-methyl-3(4)-aminomethyl cyclohexane (AMCA) bya) catalytically hydrogenating 1-formamido-1-methyl-3(4)-cyano cyclohexane (FMC) in a first reaction stage to form 1-formamido-1-methyl-3(4)-aminomethyl cyclohexane (FMA), 1-amino-1-methyl-3(4)-formamidomethyl cyclohexane (AMF), 1-formamido-1-methyl-3(4)-formamidomethyl cyclohexane (FMF) and/or AMCA, andb) reacting FMA, AMF and/or FMF in a second reaction stage with an alkaline compound to from AMCA and a formic acid derivative, andc) separating the reaction mixture obtained in step b) into components by fractional distillation and/or by crystallization and filtration.The present invention is also relates to carrying the hydrogenation reaction of step a) in the presence of a formulating agent to form 1-formamido-1-methyl-3(4)-formamidomethyl cyclohexane (FMF).Finally, the present invention relates to the intermediate products 1-formamido-1-methyl-3(4)-aminomethyl cyclohexane (FMA) and 1-formamido-1-methyl-3(4)-formamidomethyl cyclohexane (FMF).
摘要:
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 diurethane, as the carrier vapor. The diurethanes freed of low-boiling by-products in this manner may be thermally decomposed to produce diisocyanates.
摘要:
A process for the removal of at least one volatile compound from a reactive or unreactive mixture of substances with the aid of at least one micro-evaporator, the micro-evaporator displaying channels for carrying the mixture of substances having a hydraulic diameter of 5 to 1000 μm and a specific evaporator surface area of at least 103 m2/m3.
摘要:
This invention relates to polyurethane compositions which cross-link via a silane polycondensation and contain at least one alkoxysilane-functional polyurethane, at least one basic filler, at least one reaction product of an aminosilane with a maleic or fumaric ester, at least one organometallic compound and optionally additional auxiliary substances, to a process for their preparation, and to their use.