Abstract: The present invention describes a process wherein dimethyldichlorosilane is reacted, in a first step, with water present in hydrochloric acid to give a crude hydrolysate comprising cyclic and linear, chlorine-containing polydimethylsiloxanes and gaseous hydrogen chloride and, in a second step, the crude hydrolysate is treated with steam to reduce the chlorine content and form hydrochloric acid, with the hydrochloric acid formed in the second step being used in the first step.

Abstract: The invention relates to a method of using aqueous polymer dispersions based on acrylate-methacrylate copolymers as lamination adhesives for heat sealed glossy films, where the aqueous polymer dispersions have a solids content of from 20 to 65% by weight, the copolymer has a glass transition temperature of from -35.degree. to -10.degree. C., a K value of from 40 to 100 and a mean particle size of less than 200 nm, and the copolymer is obtainable by free-radical emulsion polymerization of:a) from 50 to 80 parts by weight of one or more comonomers from the group consisting of alkyl acrylates of alcohols having 2 to 10 carbon atoms,b) from 10 to 25 parts by weight of one or more comonomers from the group consisting of alkyl methacrylates of alcohols having 1 to 10 carbon atoms, andc1) from 0 to 10 parts by weight of one or more vinyl-aromatic comonomers,c2) from 0.1 to 4.0 parts by weight of one or more .alpha.,.beta.-unsaturated, monoolefinic carboxylic acids,c3) from 0 to 4.0 parts by weight of one or more .

Abstract: The invention relates to organo(poly)siloxane compositions which have long shelf life in the absence of water, but can be crosslinked in the presence of water, even at room temperature, to give elastomers with elimination of alcohols, and to a process for the preparation of such compositions.

Abstract: A process for defoaming and/or degassing organic systems by addition of an organopolysiloxane-containing anti-foaming agent to the organic system is characterized by the fact that the organopolysiloxane used is one composed of siloxane units having the general formulae (I) and (II), in which R is a univalent hydrocarbon residue with 1 to 18 carbon atoms per residue; A is a residue having the general formula (a), in which R.sup.1 is a residue having the formula --CR.sup.3 H--, where R.sup.3 stands for a hydrogen atom or a univalent organic residue; R.sup.2 is a residue having the formulae --CR.sup.4 H--CH.sub.2 -- or --CH.sub.2 CH.sub.2 CH.sub.2 -- where R.sup.4 stands for a hydrogen atom or a univalent organic residue; v and w represent each O or an integer, the sum of v+w being in average 0 to 16; x and y represent each 0 or 1, the sum x+y being 1 or 2; a equals 1,2 or 3; b equals 0, 1 or 2 and c equals 1 or 2, the sum b+c not exceeding 3.

Abstract: The invention concerns iodonium salts of the general formula A-I.sup.+ --B X.sup.-, in which A is a group of the general formula ##STR1## in which C is a monovalent aromatic hydrocarbon group with 6 to 14 carbon atoms or a monovalent aromatic hydrocarbon group containing at least one oxygen and/or sulphur atom and with 5 to 14 atoms in the aromatic ring, D, E and F are each substituents of C, D being a group of the formula --(O).sub.x --(R).sub.y --SiR1/3, E being a group of the formula --OR.sup.2, F being a group of the formula --R.sup.3, a being 1, 2, or 3, b being 0, 1 or 2, c being 0, 1 or 2, x being 0 or 1 and y being 0 or 1, and R, R.sup.1, R.sup.2 and R.sup.3 are as defined in claim 1; B is a group of the formula ##STR2## in which E and F, which are as defined above, may each be bound to the 2, 3, 4, 5 or 6 position in the benzene ring, d is 0, 1 or 2, e is 0, 1 or 2 and X.sup.- is a tosylate anion or a weakly nucleophilic or non-nucleophilic anion Y.sup.- selected from the group comprising CF.sub.

Abstract: The present invention provides photoactive sulfonium salts which can be employed as photoinitiators for the polymerization of cationically polymerized organic substances and are soluble in these substances.

Abstract: The aqueous emulsions based on(a) 100 parts by weight of organopolysiloxanes which contain polar groups on Si--C-bonded hydrocarbon radicals and(b) not more than 50 parts by weight of alkyl polyglycosides which are stable toward high concentrations of foreign electrolytes.

Abstract: A process for continuously rendering finely divided, pyrogenic silica hydrophobic at low temperatures in the presence of a hydrophobicizing aid such as aliphatic alcohols having from 1 to 3 carbon atoms. The process of rendering silica hydrophobic is conducted at temperatures of from 60.degree. to 350.degree. C., and more preferably from 80.degree. to 150.degree. C., over a period of from 2 to 5 hours, and more preferably from 3 to 4 hours. The hydrophobicizing agents are known organohalosilanes and the preferred hydrophobicizing aid is methanol. The hydrophobicizing aid is used in amounts of from 2% to 15% by weight, and more preferably in amounts of from 2% to 10% by weight, based on the weight of silica used.

Abstract: The invention relates to a process for preparing ketene acetals by dehydrohalogenation of 2-haloaldehyde acetals. If the 2-haloaldehyde acetal is open chain, the dehydrohalogenation is carried out in the presence of an alkali metal hydroxide or alkaline earth metal hydroxide and a phase transfer catalyst and/or a secondary or tertiary alcohol or a secondary or tertiary diol. If the 2-haloaldehyde acetals is cyclic, the dehydrohalogenation is carried out in the presence of an alkali metal hydroxide or alkaline earth metal hydroxide and a phase transfer catalyst and with or without a secondary or tertiary alcohol or a secondary or tertiary diol, or carried out in the presence of an alkali metal hydroxide or alkaline earth metal hydroxide and a secondary or tertiary diol. The ketene acetals which can be prepared by the process of the invention serve as intermediates in organic synthesis and are suitable as monomers or comonomers in free radical polymerization for the production of biodegradable plastics.

Abstract: The invention relates to a method for the automatic control of batch processes by means of a process control in which the automatic control programs access individual control modules, wherein a) the control instructions and parameter definitions contained in the partial formulations or phases of the formulation program are stored in a separate program level for the activation, interlocking and switch-on blocking of actuators in the field, b) in the separate program level, the control instructions and parameter definitions for each actuator to be activated are collected actuator by actuator and, if appropriate, logically combined, and c) the currently effective activations, interlockings and switch-on blockings are output, actuator by actuator, to the process operating and monitoring system.

Abstract: Organopolysiloxanes which contain ester groups and comprise units of the formula ##EQU1## in which R may be an identical or different monovalent, SiC-bonded hydrocarbon radical having 1 to 18 carbon atoms,A may be an identical or different radical of the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, c, v, w, s, t,is 0 or an integer, the sum of s and tbeing an integer from 1 to 20,x is 0 or 1,y is 0 or 1, the sum of x and y being 1 or 2,a is 0, 1, 2 or 3, andb is 0, 1 or 2,with the proviso that the sum of a and b is less than or equal to 3 and the organopolysiloxane contains at least one radical A per molecule.

Abstract: The invention concerns aqueous emulsions of (A) organopolysiloxane free from basic nitrogen and (B) alkyltrialkoxysilane which contain (C) an emulsifier and (D) water. Organopolysiloxane (A) has formula R.sub.a Si(OR.sup.1).sub.b O.sub.4-a-b/2 wherein R has identical or different, monovalent, optionally substituted C.sub.1 -C.sub.18 hydrocarbon residues bonded by SiC, R.sup..sup.1 has identical or different, monovalent, optionally substituted C.sub.1 -C.sub.6 hydrocarbon residues, a is equal to 0, 1, 2 or 3, on average 0.75 to 1.5, and b is equal to 1, 2 or 3, on average 0.2 to 2.0, and has a molecular weight of at least 600 g/mol. Also disclosed are a method for preparing said emulsions and their use for water-repellent impregnation of cement-bonded fibrous building components.

Abstract: The description relates to novel organo(poly)siloxanes of the general formula (I): (R.sup.1 O).sub.a HSiR.sub.2-a O[SiR .sub.2 O].sub.n SiR.sub.2 R.sup.2, in which R and R.sup.2 are the same or different and represent a monovalent, possibly substituted hydrocarbon radical; R.sup.1 is the same or different and represents a monovalent, possibly substituted hydrocarbon radical; n is a whole number of at least 2; and a is 1 or 2. The organo(poly)siloxanes are used as additives in materials which can be cross-linked to form organopolysiloxane elastomers.

Abstract: A process is described for the preparation of dimethylchlorosilane by redistribution of dimethyldichlorosilane with methylchlorosilane and/or methylsilane in the presence of a catalyst. The catalyst may be shapeless or in the form of spheres and is a polymeric, optionally crosslinked organosiloxane-ammonium compound having a silica-type backbone.

Abstract: Organosiloxanes comprising at least one chemically bonded transition metal complex of Pt, Pd, Rh, Ru, Os or Ir, having a triazene, tetrazene, tetrazdiene, pentazdiene or triazene oxide ligand and are used as hydrosilylation catalysts that can be activated by light and/or heat.

Abstract: A method for the extraction of organic pollutants from contaminated soils without further contaminating the soil with organic solvents comprises the step of mixing aqueous solutions of cyclodextrins or their derivatives with the contaminated soil.

Abstract: The present invention relates to oxygen-containing chlorophosphazenes containing organosilicon radicals, in particular those of the formulaZ-PCl.sub.2 =N(-PCl.sub.2 =N).sub.n -PCl.sub.2 O (I)in whichZ is an organosilicon radical bonded to phosphorus via oxygen andn is from 0 to 6, processes for their preparation and their use in processes for the condensation and/or equilibration of organosilicon compounds.

Abstract: Disclosed are organopolysiloxane preparations containing: A) units of the formula (I): (R.sup.1 O).sub.a SiHR.sup.2.sub.2-a O1/2, in which R.sup.1 and R.sup.2, which may be the same or different, are each, independently of each other, an optionally substituted monovalent hydrocarbon group and a is 1 or 2, B) siloxane units which can be cross-linked by irradiating and, optionally, C) siloxane units acting as photo-initiators. These preparations are useful for the production of coatings.

Abstract: In the method for coating substrate surfaces which are not water-absorbent, the substrate surfaces are coated with an aqueous composition which comprises an aqueous solution, dispersion and/or emulsion of film-forming substances and water-repellent substances, in which the coating can be removed by treatment with water. The method is also suitable for coating porous, water-absorbent substrates if the substrates are treated with a water-repellent prior to coating with the aqueous composition.

Abstract: Sealing compositions containing dispersions of polymers of ethylenically unsaturated monomers comprising(a) polymers of ethylenically unsaturated monomers,(b) 0.1 to 5% by weight of branched organopolysiloxanes, based on the total weight of the sealing compositions,(c) dispersing agent,(d) filler and(e) water.