Abstract: Copolymers of ethylene have from 1 to 30 mol % of alkyl(meth)acrylates and, if desired, other comonomers, and have a residual comonomer content of less than 0.5% by weight in the copolymer. A process for preparing copolymers of this type in a combination of stirred autoclave and tubular reactor is described, as is the use of the copolymers for preparing polyamide molding compositions.

Abstract: The invention provides a process for preparing an aqueous polymer dispersion of a copolymer CP of at least two different monomers M1 and M2 by free-radical aqueous emulsion polymerization of the monomers M in the presence of at least one initiator, at least 80% of the monomers M and at least 75% of the initiator being supplied continuously to the polymerization reaction during its course, which comprises changing the rate at which the initiator is supplied to the polymerization reaction a number of times, or continuously, during the polymerization reaction. The invention further provides the polymer dispersions obtainable by this process, polymer powders prepared therefrom, and for the use of the dispersions and/or of the polymer powders to prepare pressure sensitive adhesives.

Abstract: The present invention relates to a process for the preparation of tetrahydrogeraniol, wherein the product mixtures and distillation residues from linalool, citronellal, citronellol or geraniol/nerol synthesis are fed directly to catalytic hydrogenation.

Abstract: Alkali metal methoxides are prepared from aqueous alkali metal hydroxide, which may have been admixed with methanol, and methanol in a reaction column having at least 5, preferably from 15 to 30, theoretical plates between the feed point for the aqueous alkali metal hydroxide and the feed point for the methanol. The gaseous methanol/water mixture formed in the reaction is fractionated in a rectification column. In one variant of the invention, the trays chosen for the reaction column configured as a bubble cap tray, valve tray or sieve tray column are trays in which not more than 5%, preferably <1%, of the liquid rains through the respective trays. In another variant of the process of the present invention, the double-wall reaction column has a temperature in the double wall which is from 3 to 10° C.

Abstract: A process for the preparation of creatine or creatine monohydrate by reaction of sodium or potassium sarcosinate with cyanamide at a temperature from 20 to 150° C. and a pH from 7.0 to 14.0 comprises carrying out the pH adjustment with carbonic acid.

Abstract: A process for working up hydroxylamine-containing solutions as obtained in particular in the electronics industry during the cleaning of electronic components is described. According to the invention, the hydroxylamine is stripped from the wastewater with steam. The products obtained are aqueous hydroxylamine and an aqueous solution of the amines. Both product streams can be purified in further process steps to give a saleable product.

Abstract: Hydroxylamine solutions stabilized using tri(4-(2,3-dihydroxyphenyl)-4-oxabutyl)amine, tri(4-(2,3-dihydroxyphenyl)-4-keto-3-azabutyl)amine or salts thereof, and methods of stabilizing hydroxylamine solutions using these compounds.

Abstract: A process for preparing an aqueous dispersion of composite particles composed of addition polymer and finely divided inorganic solid, in which process at least one ethylenically unsaturated monomer is dispersely distributed in aqueous medium and is polymerized by the method of free-radical aqueous emulsion polymerization by means of at least one free-radical polymerization initiator in the presence of at least one dispersely distributed, finely divided inorganic solid and at least one dispersant.

Abstract: An apparatus (1) is proposed for drying and heat-treating pellets with a stream of inert gas, wherein the apparatus has a cuboid base unit (2) with a feed (3) for the pellets in its upper part and an outlet (4) in its lower part, with a feed (5) on one lateral surface and with an exhaust base (6) on the opposite lateral surface of the cuboid base unit (2) for the stream of inert gas, and also with distribution and retention equipment (7, 8) in the region of the feed (5) and, respectively, of the exhaust (6) for the stream of inert gas, where each of these extends essentially over the entire vertical cross section of the cuboid base unit (2).

Abstract: The tert-butyl ester of an aliphatic C1-C4-carboxylic acid is prepared by reacting the carboxylic acid with isobutene in the liquid phase in the presence of an acidic catalyst by a continuous process in which the reaction is carried out in a reactor divided into a plurality of sections, the carboxylic acid, the isoolefin and the catalyst are fed into the first section of the reactor, the reaction mixture obtained is removed from the last section of the reactor and the ester is isolated therefrom, the reaction temperature in the reactor being controlled so that it is from 10 to 40° C. and is highest in the first section of the reactor. The novel process permits the technically simple, economical and environmentally friendly preparation of tertiary butyl esters of saturated and unsaturated C1-C4-carboxylic acids.

Abstract: Continuous process for preparing polyoxymethylene homo- or copolymers by bulk polymerization of the monomers in the presence of cationic initiators, and also, if desired, in the presence of regulators, where during the polymerization both the monomers and the polymer are present in molten form and, if desired, the polymer is then deactivated, and the melt is discharged, cooled and pelletized, which comprises discharging, cooling and pelletizing the polymer at an elevated pressure and in the presence of a liquid.

Abstract: The invention proposes a reactor (1) having a contact tube bundle (2) through whose space surrounding the contact tubes a heat-exchange medium circuit is passed, with ring lines (3, 4) at both ends of the reactor with jacket apertures (5, 6) for the supply and discharge of a heat-exchange medium by means of a pump via an external heat exchanger, where the heat-exchange medium is fed to the lower ring line (4) and is discharged to the heat exchanger via the upper ring line (3), and with baffle plates (7) which leave a passage cross section alternately in the reactor center and at the reactor edge.

Abstract: A process for the preparation of propylene oxide in which (i) propene is reacted with hydrogen peroxide in the presence of methanol to give propylene oxide, giving a mixture (Gi) comprising propylene oxide, methanol, water and unreacted hydrogen peroxide, (ii) a mixture (Gii) comprising methanol, water and hydrogen peroxide is separated off from the mixture (Gi), giving a mixture (Ga) comprising propylene oxide, and (iii) water is separated off from the mixture (Gii), giving a mixture (Giii) comprising methanol and methyl formate.

Abstract: The present invention relates to the use of compositions comprising reaction products of low molecular mass dicarboxylic or tricarboxylic acids with ammonia to produce moldings comprising finely divided materials.

Abstract: An essentially anhydrous dithiocarbamate liquid formulation comprises: a) 10 to 70% by weight of at least one active ingredient from the class of the dithiocarbamates, b) 10 to 89% by weight of an essentially anhydrous oil phase, c) 1 to 40% by weight of a polyhydroxystearic acid or a derivative thereof and/or an alkyl or alkenyl glycerin ether ethoxylate, d) 0 to 40% by weight of at least one anionic surfactant.

Abstract: Polyester-polyether block copolymers can be prepared by catalytic addition of alkylene oxides onto H-functional initiator substances, using polyester alcohols as H-functional initiator substances and multimetal cyanide compounds as catalysts.

Abstract: The invention relates to a process for the preparation of aldehydes in which at least one compound containing a vinyl or vinylidene group is reacted with carbon monoxide and hydrogen in the presence of a source of a metal from sub-group VIII and in the presence of a bidentate diphosphine ligand, where the diphosphine ligand has the general formula I in which A together with the phosphorus atom to which it is bonded, in each case forms a 2-phosphatricyclo[3.3.1.1{3,7}]decyl radical, in which one or more non-adjacent carbon atoms may be replaced by oxygen atoms and which is substituted or unsubstituted, and X is a bridging chain having 1 to 10 carbon atoms, and the molar ratio between the diphosphine ligand and the metal is at least 5. The process gives predominantly n-aldehydes.

Abstract: Polyisobutene is prepared by cationic polymerization of isobutene and/or isobutene-containing hydrocarbons in the liquid phase in the presence of a complex of BF3 and at least one cocatalyst which is preferably chosen from oxygen-containing compounds, the BF3/cocatalyst complex being produced in situ by adding BF3 and cocatalyst to a reaction stream, wherein BF3 and oxygen-containing cocatalyst are added to the reaction stream via a common binary nozzle comprising an outlet for BF3 and an outlet for the oxygen-containing cocatalyst. The invention also describes a binary nozzle having a centrally arranged outlet for the catalyst.

Abstract: A process for preparing chlorine by gas-phase oxidation of hydrogen chloride by means of a gas stream comprising molecular oxygen in the presence of a fixed-bed catalyst, which is carried out in a reactor (1) having a bundle of parallel catalyst tubes (2) which are aligned in the longitudinal direction of the reactor and are fixed at their ends into tube plates (3), with a cap (4) at each end of the reactor (1) and with one or more deflection plates (6) which are arranged perpendicular to the longitudinal direction of the reactor in the intermediate space (5) between the catalyst tubes (2) and leave passages (7) located alternately on opposite sides of the reactor free next to the interior wall of the reactor (1), with the catalyst tubes (2) being charged with the fixed-bed catalyst, the hydrogen chloride and the gas stream comprising molecular oxygen being passed from one end of the reactor via a cap (4) through the catalyst tubes (2) and the gaseous reaction mixture being taken off from the opposite end of

Abstract: A process for preparing chlorine by gas-phase oxidation of hydrogen chloride by means of a gas stream comprising molecular oxygen in the presence of a fixed-bed catalyst, which is carried out in a reactor (1) having a bundle of parallel catalyst tubes (2) which are aligned in the longitudinal direction of the reactor and are fixed at their ends into tube plates (3), with a cap (4) at each end of the reactor (1) and with one or more annular deflection plates (6) which are arranged perpendicular to the longitudinal direction of the reactor in the intermediate space (5) between the catalyst tubes (2) and leave circular passages (8) free in the middle of the reactor and one or more disk-shaped deflection plates (7) which leave annular passages (9) free at the edge of the reactor, with an alternating arrangement of annular deflection plates (6) and disk-shaped deflection plates (7) with the catalyst tubes (2) being charged with the fixed-bed catalyst, the hydrogen chloride and the gas stream comprising molecular o