Abstract: A partially hydrophobic precipitated silica having a methanol wettability of 10 to 49%, in particular with a DBP uptake on a dry basis of greater than 250 g/100 g and a mean particle size of 1 to 12 &mgr;m and/or a carbon content of 0.3 to 1.85% and/or a loss on drying of 2.6 to 10.0% and/or a pH value of 5.5 to 10.0, is prepared by mixing the amount of water-repellent agent with the precipitated silica suspension at very short residence time and low pH value, filtering off the solid substance, washing free of salt, drying, post-treating thermally and milling. The partially hydrophobic precipitated silica can be used in active substance formulations and active substance formulations of hydrolysis-sensitive substance and in defoaming agents.

Abstract: A method for the production of D-pantothenic acid by the fermentation of microorganisms of the family Enterobacteriacae producing D-pantothenic acid which is characterized in that strains are used which a) Contain the plasmid pFV31 and/or pFV202 and that b) A panD gene and optionally other nucleotide sequences coding for aspartate-1-decarboxylase are enhanced, especially overexpressed in these microorganisms, c) The pantothenic acid is enriched in the medium or in the cells of the microorganisms and d) The pantothenic acid formed is isolated.

Abstract: A process for preparing crude dimethyl terephthalate, comprises oxidizing a mixture comprising para-xylene and methyl para-toluate, esterifying the oxidized mixture with methanol, separating the resulting crude ester into fractions. By separating the crude ester with a distillation column containing structured packing and using a lower bottom temperature, product yield is increased, and the process is made more economical.

Abstract: An alcoholic fluoroalkyl-functional group containing organosiloxane based composition is prepared by the controlled hydrolysis of at least one fluoroalkyl-functional group containing organosilane of formula I: R1—Y—(CH2)2SiHx(R2)y(OR)3−x−y  (I), in which R1 is a mono, oligo- or perfluorinated alkyl group having 1-9 C atoms or a mono-, oligo- or perfluorinated aryl group, Y is a CH2, O or S group, R2 and R are each independently a linear, branched or cyclic alkyl group having 1-8 C atoms or an aryl group and x=0, 1 or 2 and y=0, 1 or 2, where (x+y)≦2, at a temperature in the range of 0-120° C. over a period of 0.5-24 hours and with thorough mixing in an alcoholic medium which contains water and a weak mono- or polybasic acid or a weak base or a weak mono- or polybasic acid and a weak base or an acid or basic salt, the water employed and the alkoxysilane employed being in a molar ratio of 2-500:1.

Abstract: The present invention relates to a process for neutralizing and reducing the residual halogen content in alkoxysilanes and alkoxysilane-based compositions, which includes treating an alkoxysilane having a residual content of acidic halide, or a corresponding alkoxysilane-based composition, with metallic magnesium in the presence of an alcohol and separating off the resulting solids.

Abstract: Partially or totally blocked polyisocyanates comprising physical mixtures of individuala) urethane-functional and/orb) biuret-functional and/orc) isocyanurate-functionalaliphatic and (cyclo)aliphatic and/or cycloaliphatic diisocyanate whose isocyanate groups are blocked in such a way that there is from 0.5 to 1 mol, preferably from 0.8 to 1 mol, of 1,2,4-triazole per isocyanate equivalent.

Abstract: The invention relates to a novel method for preparing cyclopropanecarboxylic acids by acidolysis of the corresponding esters, using an alkylbenzenesulfonic acid represented by the formula: ##STR1## as the reaction catalyst, where m+n is 5 to 15. Process-engineering improvements and simplifications are achieved with this process.

Abstract: Composite comprising a polyamide-based molding composition and vulcanized fluoroelastomers. Composite articles comprising at least two subcomponents which are firmly joined to one another which comprise i) a vulcanizate and ii) a polyamide containing thermoplastic whereina) said polyamide containing thermoplastic comprises at least 30% by weight of polyamide and in said polyamide at least 30% of the end groups are amino end groups andb) said vulcanizate is produced by vulcanization of a fluororubber compound while in contact with said polyamide containing thermoplastic.

Abstract: A connector for connecting an assembly to a pipe, which is highly leakproof with respect to the medium to be transported and is secure against separation under axial load. The connector comprises two materials A and B which swell to different degrees. A part comprising the more strongly swelling material A has, at the junction with the material B, a peripheral connecting lip which is substantially enclosed by the less swelling material B, so that a positive connection is achieved.

Abstract: A two-component polyurethane coating composition essentially comprising (A) a polyols component, (B) a polyisocyanate component, wherein the polyisocyanate component (B) comprises at least 30% by weight of a polyisocyanate based on 2-methylpentane-1,5-diisocyanate and a polyisocyanate based on isophorone diisocyanate, the sum of the two polyisocyanates being 100% by weight.

Abstract: A urea- and uretdione-functional polyaddition compound having free, partially or totally blocked isocyanate groups and having the following structure: ##STR1## wherein the substituents are defined as follows: ##STR2## n: 1-20; R.sub.1 is R or a linear, branched or cyclic alkylene or phenylene radicals having 2-16 carbon atoms;R.sub.2, R.sub.3 are each H, R.sub.4 or a ##STR3## R.sub.4, R.sub.5 are each identical or different hydrocarbon radicals having 1-14 carbon atoms;prepared by reacting isophorone diisocyanate-uretdione with diamine mixtures comprising 1-60 mol % diprimary diamines, 1-98 mol % primary/secondary diamines and 1-98 mol % disecondary diamines.

Abstract: A three-stage process for removing mercury contaminants from alcoholic alkali metal alkoxide solutions is provided, in which mercury is depleted in a first filtration through inert fibrous material, followed by a second filtration through pulverized coal, and then by concentration by distillation, to preferably provide a mercury content below 0.1 ppm.

Abstract: A process for preparing an alkali metal alkoxides by reacting an alkali metal amalgams and alcohols in the presence of a catalysts comprising a transition metal carbide, nitride or carbonitride, where the catalyst is in the form of a powder.

Abstract: A process for preparing alkoxysilanes by reacting alcohols with halosilanes which are dissolved in a nonpolar solvent that is immiscible with the alcohol.

Abstract: Liquid melts of dicarboxylic acid have a tendency to undergo unwanted discoloration on prolonged storage. By means of a solution of the dicarboxylic acids in a lactam of an aliphatic .alpha.,.omega.-aminocarboxylic acid, the discoloration can be avoided.

Abstract: A process for preparing an alkoxysilane with an acidic chloride content of less than 10 ppm by weight, comprising:reacting a chlorosilane with an alcohol in a water-free and solvent-free phase to form a product mixture containing alkoxysilane and residual acidic chloride, with removal of resultant hydrogen chloride from the product mixture,then adding liquid or gaseous ammonia, in an amount corresponding to a stoichiometric excess, based on the content of acidic chloride, to form an ammonia-containing product mixture,treating the ammonia-containing product mixture at a temperature between 10 and 50.degree. C., wherein the ammonia and acidic chloride undergo neutralization, to form a crude product, and optionally, then separating off a salt formed in the course of neutralization, from the crude product, andrecovering the alkoxysilane by distilling the crude product.

Abstract: The invention relates to a process for preparing N,N'-disubstituted p-quinonediimines of general formula I ##STR1## wherein a corresponding N,N'-disubstituted p-phenylenediamine is oxidized in alkaline/alcoholic solution, and also their use. The invention further provides organosilanes containing methacryloxy or acryloxy groups and having general formula II ##STR2## where R.sup.3 is a hydrogen atom or a methyl group and R.sup.4 and R.sup.5 are identical or different alkyl groups having from 1 to 4 carbon atoms and m is equal to 0 or 1 or 2, which organosilanes contain N,N'-disubstituted p-quinonediimines. Processes for preparing and stabilizing organosilanes of general formula II are described.

Abstract: The invention relates to a process for the preparation of methoxyacetic acid esters in which a chloroacetic acid ester is reacted with an alkali metal methoxide to give the methoxyacetic acid ester.

Abstract: A coating formulation comprises (A) a base polyester consisting of the copolymerization product of at least one aliphatic, cycloaliphatic and/or aromatic polybasic acid and/or anhydride thereof or at least one hydroxycarboxylic acid or derivative thereof and at least one diol, and (B) an additive polyester resin prepared by condensing at least one unsaturated dicarboxylic acid and optionally at least one saturated dicarboxylic acid monomer with at least one diol and/or triol, wherein the proportion of unsaturated additive polyester to base polyester ranges from 0.1-15 parts to 99.9-85 parts.

Abstract: A process for the preparation of macrocyclic esters or lactones in a two-stage reaction, which entails effecting linear oligomerization of monomers having a number of carbon atoms corresponding to the macrocycle and effecting cyclizing deoligomerization, wherein both steps are conducted in the presence of a complex compound of trivalent iron.