摘要:
According to the process according to the invention for the preparation of anion exchange resins of the poly(meth)acrylamide type by aminolysis of bead polymers of cross-linked poly(meth)acrylic acid esters with excess polyamine, subsequent separation of the anion exchange resins from the liquid phase containing the unreacted polyamine, washing the anion exchangers free of amine with water and recovering the polyamines from the washing waters, the liquid phase containing the unreacted polyamine and the polyamine-containing washing waters are immediately mixed with the bead polymer of cross-linked poly(meth)acrylic acid ester to be subjected to aminolysis, the amount of fresh polyamine necessary for the establishment of the desired polyamine excess is added to the mixture, the mixture thus obtained is distillatively dewatered until its water content has fallen to a value of
摘要:
The invention relates to an environment-friendly process for the preparation of weakly acid cation exchange resins by hydrolysis of crosslinked acrylonitrile bead polymers with an alkaline hydrolizing agent at elevated temperature, according to which the bead polymer and alkaline hydrolizing agent are brought together at elevated temperature only.
摘要:
A process for the preparation of a bifunctional anion exchange resin by partial quaternization of a weakly basic anion exchanger containing tertiary amino groups which process comprises (a) partially loading the weakly basic anion exchanger with a strong acid and (b) quaternizing the partially loaded anion exchanger by means of a customary alkylating agent.
摘要:
A rail vehicle has a longitudinal direction and includes an undercarriage, a crossbeam held against the undercarriage, extending transversely to the longitudinal direction of the superstructure and adapted for being seated on a bogie or similar structure. A mechanism is provided for elastically holding the crossbeam to the undercarriage.
摘要:
An energy-absorbing device, particularly for rolling stock to provide protection therefor when potentially damaging impact occurs, includes first and second tubular elements which are fitted into one another and which are of unlike material.
摘要:
2,4,6-Trichloroaniline is prepared by reaction of aniline, which is optionally substituted by halogen, with a chlorinating agent in the presence of inert organic solvents and/or diluents at elevated temperatures.
摘要:
A static casting method for a hollow cast product using a mold with bottom comprising a top lid, a core and an outer mold section, the core being attached to the top lid and disposed inside the outer mold section. The outer mold section includes a lateral mold section and a lower mold section. The lateral mold section is formed at its inner peripheral wall portion with a composite cooling section by stacking chiller blocks and interposing therebetween refractory sands and at its outer wall portion with refractory sands. Cooling pipes include first and second pipes. A first pipe extends longitudinally through the refractory sands at the outer wall portion and a second pipe extends longitudinally through the inner wall portion in contact with at least a part of each of the chiller blocks, the first and second pipes being connected at their lower portions through the bend portion. The chiller blocks are cooled by water flowing in the second pipes. The entire casting cavity is first filled with molten metal. Then cooling water is passed through the cooling pipes until solidification of the metal is complete. Thereafter the supply of water is stopped and water remaining in the pipes is discharged.
摘要:
A process for the preparation of neopentylamine which is virtually free from amines with a higher degree of alkylation which comprises contacting neopentanol with ammonia at a temperature of 200.degree. to 300.degree. C. in the presence of a hydrogenation catalyst. The process can be carried out under increased pressure and in the presence of catalytic amounts of hydrogen.
摘要:
A process for the preparation of a 2-hydroxycarbazole of the formula ##STR1## wherein R.sup.1 represents hydrogen, halogen or an optionally substituted alkyl, aryl or alkoxy radicalWhich comprises contacting a diphenylamine of the formula ##STR2## wherein R.sup.1 has the above-described meaning andR.sup.2 represents halogenWith a base at an elevated temperature in water and/or an organic solvent or diluent.
摘要:
An improved process for the preparation of pivaloylpyruyic acid ester by reaction of pinacolin with an oxalic acid dialkyl ester followed by neutralization of the reaction mixture is disclosed, wherein the reactants are mixed at a temperature of -50.degree. to +50.degree. C. and the reaction completed at a temperature of 35.degree. to 200.degree. C.