Abstract: In a process for the polymerization of isobutene or mixtures of isobutene with ethylenically unsaturated comonomers under the conditions of living cationic polymerization, the initiator system additionally comprises at least one nonpolymerizable, aprotic organosilicon compound having at least one Si—O bond.

Abstract: ?-Chloroisopropyl-substituted aromatics are obtained in high yield by treating isopropenyl-substituted aromatics with hydrogen chloride gas in the absence of a solvent. The ?-chloroisopropyl-substituted aromatics serve as initiators for the cationic polymerization of isobutene.

Abstract: The present invention relates to C4–C6-polymercaptopolyols as regulators in the free-radically initiated solution and precipitation polymerization of ethylenically unsaturated monomers.

Abstract: A formulation for use in chrome-free or chrome tanning is proposed, comprising a clay mineral which, after vigorous stirring for 30 minutes in water at 50° C., has a number average particle diameter of less than 2 ?m or a bimodal size distribution with a first, finely divided fraction whose number average particle diameter is less than 0.5 ?m and a second, coarser fraction whose number average particle diameter is less than 5 ?m, determined in each case by the method according to ISO 13320-1, by combined laser light diffraction and light scattering, the amount of the first, finely divided fraction being from 10 to 90% by weight, and one or more substances from one or more of the following groups: organic polymers, aldehyde tanning agents, sulfone tanning agents, resin tanning agents, phenol tanning agents, fatliquoring agents, vegetable tanning agents, dyes and pigments.

Abstract: Propylene homopolymers, wherein, in their separation according to tacticity by first dissolving the polymers in boiling xylene, then cooling the solution to 25° C. at a cooling rate of 10° C./h and then, with ascending temperature, separating the propylene homopolymers into fractions of different tacticity, either one or more of the conditions that i) the fraction of propylene homopolymers which remains undissolved on heating the cooled propylene homopolymer solution to 112° C. is greater than 20% by weight or ii) the fraction of propylene homopolymers which remains undissolved on heating the cooled propylene homopolymer solution to 117° C. is greater than 8% by weight or iii) the fraction of propylene homopolymers which remains undissolved on heating the cooled propylene homopolymer solution to 122° C. is greater than 1% by weight, are satisfied.

Abstract: The invention relates to a tanning agent that is produced by reacting at least one aldehyde of general formula (I) with at least another identical or different aldehyde of formula (I), wherein the variables are defined as follows: Z is a single chemical bond, an optionally substituted C1-C12-alkyl, an optionally substituted C5-C12-cycloalkyl or an optionally substituted C6-C14-aryl, wherein the reaction is carried out in the presence of an acid catalyst and optionally in the presence of at least another carbonyl compound of formula (II), R1 to R4 represent, independent of one another, hydrogen, optionally substituted C1-C12-allyl, optionally substituted C3-C12-cycloalkyl, optionally substituted C7-C13-aralkyl or optionally substituted C6-C14-aryl, provided that at least another aldehyde of formula (I) in which the radical of Z contains ? hydrogen atoms or at least another carbonyl compound of formula (I) is present when Z is a single chemical bond or a radical without any hydrogen atoms.

Abstract: Homo- and copolymers of isobutene are prepared by continuous cationic polymerization of isobutene or mixtures of isobutene with ethylenically unsaturated comonomers in the presence of an initiator system comprising: i) a Lewis acid selected from covalent metal-halogen compounds and covalent semimetal-halogen compounds and ii) at least one aprotic organic compound I having at least one functional group FG which forms a carbocation or a cationic complex with the Lewis acid under polymerization conditions in an organic solvent inert with respect to the Lewis acid, by a process in which the polymerization is carried out in a tubular flow-through reactor which has a plurality of curves having an alternating direction of curvature.

Abstract: The surfaces of apparatuses and apparatus parts for chemical plant construction, including, for example, apparatus, container and reactor walls, discharge apparatuses, fittings, pumps, filters, compressors, centrifuges, columns, heat exchangers, dryers, comminuting machines, internals, packings and mixing elements, are coated by a process wherein protuberances having a mean height of from 100 nm to 50 &mgr;m with a mean spacing of from 100 nm to 100 &mgr;m are produced on the surface to be coated and the coating is applied thereon by currentless deposition of a metal layer or of a metal-polymer dispersion layer with the aid of a plating bath which contains a metal electrolyte, a reducing agent and optionally a polymer or polymer blend to be deposited, in dispersed form.

Abstract: Compounds, in particular those based on polyisobutyleneamines, are suitable as emulsifiers for water-in-oil emulsions and are used in particular as additives for fuels and lubricants.

Abstract: Fuel-water emulsions in which an alkoxylated, preferably an ethoxylated, polyisobutene is used as an emulsifier are described. Stable emulsions, in particular of diesel-water mixtures, which have advantageous properties when used as fuel in internal combustion engines can be prepared in this manner.

Abstract: Catalyst systems of the Ziegler-Natta type, which are suitable for the polymerization of olefins are prepared by: A) bringing an inorganic metal oxide on which a magnesium compound has been deposited into contact with a tetravalent titanium compound, B) if desired, bringing the intermediate obtained in this way into contact with an electron donor compound and C) bringing the intermediate obtained in step A) or B) into contact with a polysiloxane.

Abstract: The present invention provides a coating composition for producing difficult-to-wet surfaces, comprising i) at least one finely divided powder whose particles have a hydrophobic surface and a porous structure characterized by a BET surface area (determined in accordance with DIN 66131) of at least 1 m2/g, and ii) at least one film-forming binder characterized by a surface tension <50 mN/m, the weight ratio of powder to binder being at least 1:4. It also provides a process for producing difficult-to-wet surfaces, and provides for the use of the coating compositions for producing surfaces having a self-cleaning effect and for reducing the flow resistance for liquids in pipes.

Abstract: The present invention relates to a process for coating apparatuses and apparatus parts for chemical plant construction—which are taken to mean, for example, apparatus, tank and reactor walls, discharge devices, valves, pumps, filters, compressors, centrifuges, columns, dryers, comminution machines, internals, packing elements and mixing elements—wherein a metal layer or a metal/polymer dispersion layer is deposited in an electroless manner on the apparatus(es) or apparatus part(s) to be coated by bringing the parts into contact with a metal electrolyte solution which, in addition to the metal electrolyte, comprises a reducing agent and optionally the polymer or polymer mixture to be deposited in dispersed form, where at least one polymer is halogenated.

Abstract: Catalyst systems of the Ziegler-Natta type comprise as active constituents a) a solid component comprising a compound of titanium or vanadium, a compound of magnesium, a particulate inorganic oxide as support and an internal electron donor compound, and as cocatalyst b) an aluminum compound and c) if desired, a further, external electron donor compound, wherein the particulate, inorganic oxide used has a specific surface area of from 350 to 1000 m2/g and a mean particle diameter {overscore (D)} in the range from 5 to 60 &mgr;m and comprises particles which are composed of primary particles having a mean particle diameter {overscore (d)} in the range from 1 to 10 &mgr;m and contain voids or channels between the primary particles, where the macroscopic proportion of voids or channels having a diameter of greater than 1 &mgr;m in the particles of the inorganic oxides is in the range from 5 to 30% by volume and the molar ratio of the compound of magnesium to the particulate, inorganic oxide is from 0.

Abstract: The invention relates to a process for the production of a heat transfer device, which comprises electroless chemical deposition of a metal/polymer dispersion layer, in which the polymer is halogenated, on a heat transfer surface. The invention furthermore relates to a process for the production of a heat transfer device, wherein a metal/phosphorus layer with a thickness of from 1 to 15 &mgr;m is applied by electroless chemical deposition before application of the metal/polymer dispersion layer. The invention furthermore relates to a heat transfer device which can be produced by a process according to the invention, and to the use of a coating, produced by electroless chemical deposition of a metal/polymer dispersion layer, in which the polymer is halogenated, for reducing the tendency of the coated surfaces to accumulate solids from fluids, causing fouling.

Abstract: A process for coating a reactor, which comprises depositing a metal layer or a metal/polymer dispersion layer on the internal surface of the reactor in an electroless manner by bringing the surfaces into contact with a metal electrolyte solution which, besides the metal electrolyte, comprises a reducing agent and optionally a halogenated polymer to be deposited in dispersed form.

Abstract: Propylene polymers containing a matrix of a propylene homopolymer and a copolymer of propylene and other alkenes, wherein, during the separation of the propylene polymers according to tacticity and comonomer distribution of the polymer chains, by first dissolving the propylene polymers in boiling xylene, then cooling the solution at a cooling rate of 10° C./h to 25° C. and thereafter, increasing the temperature, separating the propylene polymers into fractions of different solubility, either one or more of the conditions that i) more than 20% by weight of the matrix remain undissolved on further heating to 112° C. or ii) more than 8% by weight of the matrix remain undissolved on further heating to 117° C. or iii) more than 1% by weight of the matrix remain undissolved on further heating to 122° C. are fulfilled by the matrix which remains undissolved on heating the cooled propylene polymer solution to 80° C.

Abstract: A process for coating surfaces in apparatuses or apparatus parts for plant construction, preferably for chemical plant construction, involves optionally first hydrophobicizing a polymer film having a microstructured and optionally additionally macrostructured surface and then fixing it on the apparatus or apparatus part to be coated, and also apparatuses and apparatus parts thus coated.

Abstract: The catalyst systems comprise as active constituents a) a titanium-containing solid component comprising a compound of titanium, a compound of magnesium, a halogen, an inorganic oxide as support and a carboxylic ester as electron donor compound, and also, as cocatalyst, b) an aluminum compound and c) optionally a further electron donor compound, wherein the inorganic oxide used has a pH of from 1 to 6, an average particle diameter of from 5 to 200 &mgr;m, an average primary particle diameter of from 1 to 20 &mgr;M and voids or channels having an average diameter of from 0.1 to 20 &mgr;m and a macroscopic share of the volume of the overall particle within the range from 5 to 30%.