Abstract:
A process for mixing a liquid or mixture of a liquid and a fine solid present in a vessel, in which the vessel is supplied with the same liquid or the same mixture as a motive jet of a jet nozzle which is present in the vessel and has a motive jet and a momentum exchange chamber, the suction region between motive nozzle and momentum exchange chamber being provided with a sheath which has a suction orifice below the central jet leading from the motive nozzle into the momentum exchange chamber.
Abstract:
The invention relates to processes for preparing water absorbing polymers by polymerization of a monomer solution comprising allyl acrylate and/or allyl alcohol, the solution comprising not more than 0.002% by weight of allyl acrylate and/or allyl alcohol, based on acrylic acid, to aqueous monomer solutions for producing water absorbing polymers, to water absorbing polymers, to processes for producing hygiene articles and also to hygiene articles.
Abstract:
Polymetal oxide materials of the general formula I �A!.sub.p �B!.sub.q (I), where ##STR1## X.sup.1 is W, Nb, Ta, Cr and/or Ce, X.sup.2 is Cu, Ni, Co, Fe, Mn and/or Zn, X.sup.3 is Sb and/or Bi, X.sup.4 is Li, Na, K, Rb, Cs and/or H, X.sup.5 is Mg, Ca, Sr and/or Ba, X.sup.6 is Si, Al, Ti and/or Zr, X.sup.7 is Mo, W, V, Nb and/or Ta, a is from 1 to 8, b is from 0.2 to 5, c is from 0 to 23, d is from 0 to 50, e is from 0 to 2, f is from 0 to 5, g is from 0 to 50, h is from 4 to 30, i is from 0 to 20, x and y are each a number which is determined by the valency and frequency of the elements other than oxygen in I and p and q are non-zero numbers whose ratio p/q is from 160:1 to 1:1, and their use as catalysts.
Abstract:
Multimetal oxide compositions having a two-phase structure and comprising molybdenum, hydrogen, one or more of the elements phosphorus, arsenic, boron, germanium and silicon, and copper, and their use for the preparation of methacrylic acid by gas-phase catalytic oxidation.
Abstract:
A process for inhibiting unwanted free-radical polymerization of acrylic acid present in a liquid phase P whose acrylic acid content is at least 10% by weight and which, based on the weight of the acrylic acid present therein, additionally comprises at least 100 ppm by weight of propionic acid and at least 100 ppm by weight of glyoxal, in which at least one chemical compound of the element copper is added to the liquid phase P, and the resulting liquid phases P to which a chemical compound of the element copper has been added.
Abstract:
In the preparation of esters of acrylic or methacrylic acid by esterification with alcohols, the interfering deposits formed on the apparatus parts by relatively high molecular weight by-products can be avoided, removed or lessened by allowing a liquid partly or wholly consisting of the alcohol used for the esterification to act on the deposits, fouled apparatus parts or on the surfaces of the apparatus parts on which deposits are easily formed, with preference being given to wetting the deposits or surfaces using suitable nozzles or cleaning sprayers.
Abstract:
A process for inhibiting unwanted free-radical polymerization of acrylic acid present in a liquid phase P whose acrylic acid content is at least 10% by weight and which, based on the weight of the acrylic acid present therein, additionally comprises at least 100 ppm by weight of propionic acid and at least 100 ppm by weight of glyoxal, in which at least one chemical compound of the element copper is added to the liquid phase P, and the resulting liquid phases P to which a chemical compound of the element copper has been added.
Abstract:
A process for mixing a liquid stored in a vessel, in which gas is sucked in from the gas phase present above the liquid interface with a suction apparatus present in the liquid, and released into it again for the gas-induced mixing of the liquid.
Abstract:
A process for mixing a liquid stored in a vessel, in which gas is sucked in from the gas phase present above the liquid interface with a suction apparatus present in the liquid, and released into it again for the gas-induced mixing of the liquid.
Abstract:
A process for inhibiting unwanted free-radical polymerization of acrylic acid present in a liquid phase P whose acrylic acid content is at least 10% by weight and which, based on the weight of the acrylic acid present therein, additionally comprises at least 100 ppm by weight of propionic acid and at least 100 ppm by weight of glyoxal, in which at least one chemical compound of the element copper is added to the liquid phase P, and the resulting liquid phases P to which a chemical compound of the element copper has been added.