摘要:
Para-coupled products of the 1-naphthol series can be destroyed in the presence of the ortho-coupled product by reduction with salts of dithionous acid or of hydroxymethanesulphinic acid or with hydrazine optionally in the presence of redox-catalysts.
摘要:
Stable, concentrated solutions of anionic dyestuffs are prepared by reacting the alkali metal or ammonium salts of anionic dyestuffs and brighteners, which are usually obtained from the industrial preparation process, in water-soluble organic solvents, optionally in the presence of water, with salts of nitrogen bases which impart hydrophilic properties, in accordance with the reaction equationMe.sub.n F + nB.multidot.A.fwdarw.Bn.multidot.F + nMeAin whichMe denotes an alkali metal or ammonium ion,B denotes a protonated or quaternized nitrogen base,A denotes the anion of an acid,N denotes an integer from 1 to 4 andF denotes the anion of a dyestuff acid,And separating the resulting solutions from the salt n.multidot.MeA, which is insoluble in the reaction mass.
摘要:
The invention relates to cleaning compositions comprising (a1) a phenolic antioxidant of the formula (1) and/or (2); and/or (a2) an antioxidant of the formula (3); and (b) a surfactant comprising a long alkyl or alkenyl chain. The antioxidants used according to the invention have excellent reactivity, good stability to hydrolysis, particularly in an alkaline medium, and, because of their solubility, can be easily incorporated into the soap formulations.
摘要:
A method of and apparatus for supplying pulverulent material includes a fluidizing unit which is introduced into a transport container containing the pulverulent material. The fluidizing unit causes suspension or floating of the pulveulent material in the transport container. A suction unit and a discharge unit such as an injector withdraws fluidized pulverulent material and conveys it to the processing device. The fluidizing unit and the discharge unit are preferably combined to a constructional unit which is adjustable relative to the fluidizing unit. Thus, the use of separate powder containers is avoided as the transport container in which the pulverulent material is contained is directly used as a powder container.
摘要:
The invention relates to the preparation of storage-stable, concentrated solutions of urea compounds of the formulaF.sub.1 --HN--CO--NH--F.sub.2wherein F.sub.1 and F.sub.2 denote radicals of dyestuffs or dyestuff intermediates containing acid groups by reacting 2 equivalents of amines of the formulaF.sub.1,2 --NH.sub.2with one equivalent of a compound of the formulaCl--CO--Xwherein X is chlorine or an aryloxy radical in the presence of alkaline earth metal ions in the pH range of 4.0 to 8.0, separating off the sparingly soluble alkaline earth metal salt of the resulting urea compounds, adding -- for example -- a salt of lithium of which the anion forms a salt, which is sparingly soluble in the reaction medium, with the alkaline earth metal cation of the urea compound to the suspension of these urea compounds and separating off the alkaline earth metal salt which has precipitated.
摘要:
A method for cleaning a cyclone which separates excess powder aspirated from a powder coating cabin, and cyclones for carrying out this cleaning method are created, with cleaning air being aspirated during the cleaning operation from the lower end of the cyclone via the cyclone interior, the immersion tube and the clean gas channel, and at least the outer surface of the immersion tube and the cyclone interior facing surface of the bottom of the clean gas channel is cleansed by means of compressed air blasts which exit from nozzles and directly impact these surfaces.
摘要:
A method and an apparatus for electrostatic coating of workpieces with powdered material includes a plurality of successively arranged spray guns which are passed by the workpieces. At least the spray gun which is passed first by the workpieces is charged with recycled powder while at least the spray gun which is passed last by the workpieces is charged with fresh powder in form of a powder-air mixture containing a low amount of air and supplied at low velocity.
摘要:
New disazo and polyazo dyestuffs which, in the form of the free acid, correspond to the general formula ##STR1## wherein K, R, m and n have the meaning indicated in the description,the use of these dyestuffs for dyeing and printing cellulose fibre materials and leather, and concentrated solutions containing azo dyestuffs according to formula (I).