Abstract: The invention relates to a process for preparing phthalic anhydride, in which the catalytic gas-phase oxidation of o-xylene and/or naphthalene is carried out over at least three zones of catalysts of increasing activity, with only the last zone of the catalyst system containing phosphorus and the last zone also comprising at least 10% by weight of vanadium (calculated as V2O5) based on the active composition of the catalyst and having a ratio of vanadium (calculated as V2O5) to phosphorus of greater than 35.

Abstract: Process for preparing high-concentration gaseous formaldehyde having a molar CH2O:H2O ratio of ?0.6 from an aqueous formaldehyde solution by evaporation of at least part of the solution, in which the aqueous formaldehyde solution is heated to a vaporization temperature T and the gas phase formed is taken off, wherein the evaporation temperature T obeys the relationship: T[° C.]?T?min[° C.] where T?min(c)=A+B×(c/100)+C×(c/100)2+D×(c/100)3 and A=+68.759, B=+124.77, C=?12.851, D=?10.095, where c is the instantaneous CH2O content of the aqueous formaldehyde solution during the evaporation in percent by weight and is from 20 to 99% by weight.

Abstract: The invention relates to isocyanate adducts which can be prepared by reacting at least one polyisocyanate with compounds having at least two hydrogen atoms which are reactive toward isocyanate groups and have a crystalline content of less than 10 J/g determined by differential scanning calorimetry in accordance with DIN 51 004 at 20 K/min from room temperature to 250° C. using a nitrogen flow of 3 l/h as carrier gas and an aromatics content reported as carbon atoms in aromatic rings of less than 31% by weight, based on the total weight of the isocyanate adducts.

Abstract: A composition for the treatment of metal surfaces and for the deposition of metals or metal alloys on plastics surfaces contains a) at least one polymer as component A, composed of the structural element (1) and at least three structural elements selected from the group consisting of b) water or another solvent which is suitable for dissolving, dispersing, suspending or emulsifying the polymer, as component B; c) if required, surface-active compounds, dispersants, suspending media and/or emulsifiers as component C. In a process for the treatment of a metal surface and a process for the deposition of metals or metal alloys on a plastics surface, the metal or plastics surface is brought into contact with a polymer (component A). Furthermore, polymers (component A) are used for the treatment of metal surfaces and for the deposition of metals or metal alloys on a plastics surface, and polymers composed of special components A?a, A?b and A?c.

Abstract: Process for removal of residual styrene monomers from polystyrene and from blends comprising water-insoluble, crosslinked polyvinylpyrrolidone, via treatment with water, which comprises carrying out the treatment on a particulate solid blend.

Abstract: An aqueous dispersion comprising a polyurethane synthesized from a) organic diisocyanates b) dihydroxy compounds having a molar weight of 500 to 5000 g/mol and comprising no ionic group or group that can be converted to an ionic group c) mono- to trihydric alcohols which additionally comprise an ionic group d) if appropriate, further compounds, different from a) to c), wherein the polyurethane comprises less than 0.6% by weight of urea groups (calculated with a molar weight of 56 g/mol), the ionic group of c) is at least partly neutralized with ammonia, and the reaction of compounds a), b), c), and d) does not take place in the presence of an organometallic catalyst.

Abstract: Process for production of polymer blends which are suitable as filter aids and are composed of polystyrene and of crosslinked water-insoluble polyvinylpyrrolidones via processing of the two components in an extruder, which comprises melting polystyrene in an extruder and then treating it with the polyvinylpyrrolidone, and adding, to the mixture of the components, from 0.1 to 10% by weight of water, based on the total amount of polystyrene and popcorn polymer, and extruding and comminuting the mixture.

Abstract: Method for producing tertiary phosphines by reacting a compound of the general formula (I) in which A is R1 or L2, B is R2 or L3, the R1 and R2 radicals are each independently an organic radical having in each case from 1 to 30 carbon atoms, where the R1 and R2 radicals may also be joined together; and the leaving groups L1 to L3 are each independently halogen, alkyloxy having from 1 to 10 carbon atoms or aryloxy having from 6 to 10 carbon atoms (a) with an alkali metal in an organic aprotic solvent and (b) a compound of the general formula (II) L4-R3 ??(II) in which the R3 radical is an organic radical having in each case from 1 to 30 carbon atoms; and the leaving group L4 is halogen, alkyloxy having from 1 to 10 carbon atoms or aryloxy having from 6 to 10 carbon atoms, in which the resulting reaction mixture is hydrolyzed with an aqueous base which has a pH of ?10 and the organic phase is removed from the aqueous phase.

Abstract: The present invention relates to substituted 5-phenyl pyrimidines I, which carry a radical X in the 4-position of the pyrimidine ring, a radical Y in the 6-position of the pyrimidine ring, the radical X denoting a group of the formula NR1R2, OR1a or SR1a, in which R1, R2, independently of each other, denote hydrogen, C1-C10-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, C1-C10-haloalkyl, C3-C8-cycloalkyl, C3-C8-halocycloalkyl, phenyl, or 5- or 6-membered heteroaryl or 5- or 6-membered heterocyclyl, containing 1, 2, 3 or 4 nitrogen atoms or 1, 2 or 3 nitrogen atoms and one sulfur or oxygen atom as ring members, which radicals may be unsubstituted or may carry 1, 2, 3 or 4 radicals Ra1; or the radical NR1R2 may also form a 5- or 6-membered optionally substituted heterocyclic ring, containing 1, 2, 3 or 4 nitrogen atoms or 1, 2 or 3 nitrogen atoms and one sulfur or oxygen atom as ring members, which are non-adjacent to the nitrogen of NR1R2, in which two adjacent C atoms or one N atom and one adjacent C atom can be linked

Abstract: The invention relates to a process for preparing nitrogen-containing catalysts, comprising: a) preparation of an oxidic species comprising the following components: at least one metal M selected from groups Ib to VIIb and VIII of the Periodic Table of the Elements, it being possible for the same metal to be present in different oxidation states; if appropriate one or more promoters P selected from groups Ib to VIIb and VIII of the Periodic Table of the Elements, the lanthanides, and from groups IIIa to VIa of the Periodic Table of the Elements, excluding oxygen and sulfur; if appropriate one or more elements R selected from hydrogen, alkali metals and alkaline earth metals; if appropriate one or more elements Q selected from chloride and sulfate; oxygen, the molar proportion of oxygen being determined by the valency and frequency of the elements in the oxidic species other than other oxygen; b) reaction of the oxidic species with an amine component selected from ammonia, primary and secondary amines and

Abstract: The present invention relates to an aqueous dispersion comprises a pigment (B) at least partially enveloped by at least one radiation-curable polyurethane (A), at least one radiation-curable polyurethane (A) being obtainable by reaction of (a) at least one diisocyanate with (b) at least one compound having at least two isocyanate-reactive groups and (c) at least one compound of the general formula I where R1 and R2 are the same or different and are independently selected from hydrogen and C1-C10-alkyl, X1 is selected from oxygen and N—R3, A1 is selected from C1-C20-alkylene which is unsubstituted or singly or multiply substituted by C1-C4-alkyl, phenyl or O—C1-C4-alkyl, and in which one or more nonadjacent CH2 groups may be replaced by oxygen; X2 is selected from hydroxyl and NH—R3, R3 is in each occurrence the same or different and selected from hydrogen, C1-C10-alkyl and phenyl.

Abstract: The invention relates to a method for producing 5-halo-2,4,6-tifluoroisophthalic acid of formula (I), wherein X represents F, Cl, Br, or I, by hydrolysis of 5-halo-2,4,6-trifluoroisophthalodinitrile of formula (II). Said invention is characterised in that in a first step, isophthalodinitrile (II) or a solution containing isophthalodinitrile (II) is reacted with a concentrated sulphuric acid at room temperature in order to form a 5-halo-2,4,6-trifluoroisophthalodiamide of general formula (III), and is, subsequently, heated and in a second step, isophthalic acid (I) is produced after additional heating and addition of water.

Abstract: Aqueous polymer dispersions comprising effect substances with a mean particle size of the dispersed particles of <1000 nm, in which the polymer particles comprise a polymer matrix of at least one ethylenically unsaturated monomer, at least 0.

Abstract: The present invention relates to the use of an aqueous polymer dispersion comprising methacrylic acid and N-methylolacrylamide as a binder for producing filter materials and for base paper for decorative sheets.

Abstract: Water-absorbent crosslinked polymers bearing acid groups, some or all of the acid groups being present as carboxylate groups having at least two different types of cations as counterions, processes for their preparation and mixtures of water-absorbent crosslinked polymers.

Abstract: A continuous process is proposed for preparing cyclohexyl (meth)acrylate by acid-catalyzed esterification of cyclohexanol with glacial (meth)acrylic acid in the presence of an azeotroping agent for the water of esterification and of a polymerization inhibitor, comprising the following process steps: esterification of the (meth)acrylic acid (1) with cyclohexanol (2) in the presence of the acidic catalyst (3), of the polymerization inhibitor (4) and of the azeotroping agent for the water of esterification (5) in a reaction zone (A), in which the water of esterification is removed as an azeotrope with the azeotroping agent in a distillation zone attached to the reaction zone (A) to obtain a reaction effluent (process stage A) which is fed to a neutralization in which the acidic catalyst (3) and unconverted (meth)acrylic acid (1) from the reaction effluent from the esterification are neutralized by means of an alkaline solution to obtain crude cyclohexyl (meth)acrylate (process stage B); washing of the crude c

Abstract: A reactor (1) for carrying out a reaction between two fluid starting materials (2, 3) over a catalyst bed (4) with premixing of the fluid starting materials (2, 3) before introduction into the catalyst bed within a delay time of less than 150 ms in a mixing-in device (5), wherein the mixing-in device (5) is made up of the following elements which are arranged essentially transverse to the inflow direction of the first fluid starting material stream (2): two or three rows arranged behind one another of tubes (6) which have turbulence generators on the outside and constrict the flow cross section for the first fluid starting material stream (2) to from ½ to 1/10, with the second fluid starting material stream (3) being passed through the interiors of the tubes (6) and injected via openings (7) in the tubes (6) into the first fluid starting material stream (2), and a perforated plate (10) upstream of the tubes (6) and a perforated plate (11) downstream of the tubes (6), is proposed.

Abstract: The present invention relates to UV-curable polyurethane dispersions, to a process for preparing them, and to their use.

Abstract: The invention relates to a process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, in which a fluid reaction mixture which comprises amines and from which the catalysts are separated off is formed in a reactor. After the catalysts have been separated off, a measurement of the absorption of UV/VIS radiation by the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.

Abstract: A process for preparing acrolein or acrylic acid or a mixture thereof from propane, in which propane is dehydrogenated under heterogeneous catalysis in a reaction zone A and the propylene formed is partially oxidized heterogeneously in a reaction zone, reaction zone A being operated in loop mode and reaction gas mixture input stream A fed to the reaction zone A comprising added molecular hydrogen which is added to this input stream as late as possible.