摘要:
A process for the preparation of iminodisuccinic acid alkali metal salts by reaction of maleic acid and ammonia in an aqueous medium in the presence of alkali metal hydroxides and working up thereof.
摘要:
A process for the preparation of iminodisuccinic acid alkali metal salts by reaction of maleic acid and ammonia in an aqueous medium in the presence of alkali metal hydroxides and working up thereof.
摘要:
Polymers with recurring succinyl units are prepared by reaction of maleic anhydride, maleic acid or fumaric acid with condensed liquid ammonia and polymerization of the resulting reaction product.
摘要:
Polymers having recurring succinyl units are obtained by an improved process by reaction of A, an unsaturated C.sub.4 -dicarboxylic acid or a derivative thereof, with B, a nitrogen-donating compound, in a first reaction step to give a reaction mixture comprising at least one low molecular weight reaction product, and subsequent continuous feeding of the reaction mixture into a continuously operated reactor to give the polymer in a second reaction step. In a further embodiment the invention refers to polymers having recurring succinyl units prepared by reaction of an unsaturated C.sub.4 -dicarboxylic acid or a derivative thereof with a nitrogen-donating compound in a first reaction step and subsequent feeding of the reaction mixture, without intermediate isolation, into an optionally continuously operated reactor, with removal of water, and treatment of the reaction mixture at a temperature of 140 to 350.degree. C.
摘要:
The invention relates to a method for carrying out polycondensation reactions, according to which the polycondensation of a monomeric starting material is carried out with external supply of heat in a reactor combination which has at least two stages and is composed of a pre-reactor and a high-viscosity reactor, where the low-molecular-weight elimination products produced are removed by evaporation. In the pre-reactor, the reaction product is concentrated to give a high-viscosity preliminary product. The high-viscosity preliminary product is then fed to the high-viscosity reactor, in which it reacts to completion with simultaneous introduction of thermal and mechanical energy and with a residence time of from 20 s to 60 min to give a polycondensation product.
摘要:
Textiles are washed with a liquid washing agent, softened water, and salts of at least one polycarboxylic acid. The polycarboxylic acids are present in part as sodium salt and in part as calcium or magnesium salt.
摘要:
Polyaspartic acid is prepared by reacting maleic anhydride and ammonia to give maleamic acid, polymerizing the maleamic acid and subsequently hydrolyzing the product to give polyaspartic acid or a salt thereof.
摘要:
Molten maleic anhydride is introduced in the form of fine droplets at 53.degree. C. to 250.degree. C. and preferably at 60.degree. C. to 120.degree. C. into a gas atmosphere which consists either of pure gaseous ammonia or of a gas mixture of ammonia and at least one other gas and of which the temperature is between 20.degree. C. and 500.degree. C. The process is carried out at a temperature of 120.degree. C. to 180.degree. C. for the production of polysuccinimide and at a temperature of 10.degree. C. to 120.degree. C. for the production of maleic amide acid.
摘要:
In a process for the continuous preparation of polymers with repeating succinyl units, maleic anhydride or a derivative thereof as educt A is mixed with ammonia or an ammonia-producing compound or amides of carbonic acid as educt B and in a first reaction stage these are reacted to give an N-containing low molecular derivative of maleic acid. This derivative is then polymerized in a subsequent second reaction stage. Reaction of the educts (A,B) takes place largely adiabatically in the first reaction stage. The heat of reaction thereby released is used to take the reaction mixture to the polymerization temperature and in the second reaction stage at least partially to polymerize the N-containing low molecular derivative to obtain a polymer with repeating succinyl units.