Abstract: Disclosed are spherical calcium carbonate particles that have an average diameter ranging from 0.05 ?m to 2.0 ?m and a maximum water content of 5.0 percent by weight relative to the total weight thereof. Said calcium carbonate particles are preferably obtained by reacting calcium chloride with dialkyl carbonate in the presence of an alkali metal hydroxide in aqueous solution. The components are advantageously used at the following concentrations: a) CaCl2: >10 mmol/l to 50 mmol/l; b) dialkyl carbonate: >10 mmol/l to 50 mmol/l; c) alkali metal hydroxide: 20 mmol/l to 100 mmol/l. The disclosed particles are particularly suitable as an additive or modifying agent in paper, paints, plastics, inks, adhesives, and pharmaceuticals.

Abstract: In a process for the preparation of an aqueous polymer dispersion by the free radical aqueous emulsion polymerization method, the polymerization is carried out in the presence of frozen micelles of amphiphilic substances.

Abstract: A composition of inorganic powders comprises inorganic powder, dispersant and binder. The dispersant and/or binder used is a block copolymer of the units methacrylic acid and alkyl methacrylate in which the alkyl radical can comprise from 1 to 8 carbon atoms. The individual blocks of alkyl methacrylate possess an average molecular weight of at least 4000 and the total block copolymer has an average molecular weight of up to 150,000, in each case expressed as number average (M.sub.n).

Abstract: The invention relates to a casting composition comprising a ceramic powder, an organic solvent, binder, plasticizer and a dispersant, which composition is suitable for producing green ceramic sheets by the tape casting process. The dispersant present in the casting composition of the invention is a polyvinyl alcohol/fatty acid ester having a degree of conversion in the range from 50 to 100%. The invention also relates to the use of such a casting composition for producing ceramic green sheets and a process for producing ceramic substrates using a green sheet thus produced.

Abstract: In a miniaturizable, capacitively measuring chemical semiconductor-based sensor system consisting of a sensor and a reference element which are to be brought into contact with the electrolyte to be measured, the reference element being connected in series with the sensor, the reference element consists of a highly doped semiconductor substrate or metal/semiconductor substrate which is covered with a membrane, and the sensor consists of an insulator/semiconductor substrate which is coated with a sensitive membrane, and the sensitive membrane of the sensor is more sensitive than that of the reference element.The sensor and the reference element of this sensor system may either be applied to one and the same chip or consist of individual components which are readily interchangeable with one another.

Abstract: The invention relates to a reference electrode for chemical sensors based on ion-selective field-effect transistors (CHEMFETs) in an electrolyte/insulator/semiconductor system. The reference electrode is essentially composed of a polyglutamate-coated insulator/semiconductor substrate or of a polyglutamate-coated phthalocyaninato-polysiloxane polymer film applied to an insulator/semiconductor substrate.

Abstract: Novel polymers contain phthalocyanine ring systems bonded via axial bonds to a central metal atom in the polymer chain and consist of repeating units of the general formula (I) ##STR1## In the general formula (I), Pc.sup.s is a phthalocyanine ring system having peripheral substituents, Me is the central atom of the phthalocyanine ring system, which atom is bonded in the polymer main chain, suitable central metal atoms Me being silicon and germanium, R is alkylene, R' and R" are each alkyl, cycloalkyl, aryl or alkoxy and Z is a silicon-carbon bond or further Si-containing groups. The novel polymers can be particularly advantageously used for the production of ultrathin layers by the LB technique, optically transparent films having high optical anisotropy and a high volume concentration of phthalocyanine radicals being formed.

Abstract: Information stored in a thin polymer layer is read out in a process wherein information introduced into a thin polymer layer on a metallic or semiconductor layer by electromagnetic or particle rays which produce a permanent change in the properties of the polymer layer in the irradiated areas is read out using surface plasmons.

Abstract: Thin films are produced by a process in which organic polymers having long-chain side groups are dissolved in an organic solvent, the solution is spread at the water/air interface by the Langmuir-Blodgett technique and the film is transferred onto a solid base material after evaporation of the organic solvent, and the organic polymers used are those which contain long-chain n-alkyl side groups bonded to the main chain of the polymer via polar groups, and some of these long-chain n-alkyl side groups are replaced by shorter-chain n-alkyl side groups, by branched alkyl side groups having the same or a smaller number of carbon atoms or by equally long or shorter side groups having one or more C-C multiple bonds.This process can be used to produce film elements, for example for optical filters.

Abstract: Thin films which contain a defined concentration of dye per unit area and are useful as layer elements, e.g. for optical filters, are prepared by spreading an oleophilic dye which is soluble in an organic water-immiscible solvent and an organic polymer dissolved in an organic solvent as a thin film at the water/air interface and, after the solvent has evaporated, transferring said film by the Langmuir-Blodgett technique to a solid base material.

Abstract: This invention relates to a process, which comprises spreading a metallomacrocyclic polymer dissolved in an organic, water-immiscible solvent on a water surface, removing the solvent to form a monomolecular, uniformly oriented film of said polymer on the surface of the water, immersing a substrate in the water, and withdrawing the substrate from the water, whereby said polymer film is transferred from the water surface to the substrate.

Abstract: A layer element comprises a base having a hydrophobic surface and, applied on this, one or more solid, thin, ordered layers of defined uniform and regular structure, in particular monolayers or multilayers, having a uniform orientation of the layer-forming molecules in one direction. The said layers are formed from a metallomacrocyclic polymer which is fusible and/or soluble in an organic, water-immiscible solvent and is of the general formula [M(Pcyc)O].sub.n, where M is Si, Ge or Sn, (Pcyc) is a complex-forming centrosymmetric polycyclic ring system, in particular a phthalocyanine ring system having hydrophobic substituents, and n is the mean degree of polymerization and is equal to or greater than 3. The novel layer elements can advantageously be produced by the Langmuir-Blodgett technique, in which a solid-like monolayer produced on a water surface from the metallomacrocyclic polymers is transferred to a substrate having a hydrophobic surface by immersion and withdrawal of the said substrate.

Abstract: In the production of resist images by application of a radiation-sensitive positive-working resist layer based on degradable polymers onto a substrate, imagewise exposure of the resist layer to actinic radiation and removal of the irradiated parts of the layer with development of the resist image, the radiation-sensitive resist layer used is composed of poly(diacetylenes), in particular soluble ones. Preferably, the radiation-sensitive resist layer based on the poly(diacetylenes) contains sensitizers which can be activated by actinic radiation and which, after being activated, induce or accelerate molecular degradation of the poly(diacetylenes). Dry film resists comprise a temporary dimensionally stable base and a radiation-sensitive resist layer which is applied on the base, can be degraded by exposure to actinic radiation and is based on poly(diacetylenes), in particular soluble ones, with or without a cover sheet on top of the said resist layer.

Abstract: In the production of resist images by application of a radiation-sensitive positive-working resist layer based on degradable polymers onto a substrate, imagewise exposure of the resist layer to actinic radiation and removal of the irradiated parts of the layer with development of the resist image, the radiation-sensitive resist layer used is composed of poly(diacetylenes), in particular soluble ones. Preferably, the radiation-sensitive resist layer based on the poly(diacetylenes) contains sensitizers which can be activated by actinic radiation and which, after being activated, induce or accelerate molecular degradation of the poly(diacetylenes). Dry film resists comprise a temporary dimensionally stable base and a radiation-sensitive resist layer which is applied on the base, can be degraded by exposure to actinic radiation and is based on poly(diacetylenes), in particular soluble ones, with or without a cover sheet on top of the said resist layer.

Abstract: Molecular degradation of poly(diacetylenes), in particular with production of poly(diacetylenes) having selected molecular weights, is carried out by a process in which the poly(diacetylenes), for example in solution or as solid or liquid layers, are present as a homogeneous mixture with sensitizers or sensitizer systems which can be activated chemically, those which can be activated by heat and/or those which can be activated by actinic light, and degradation of the poly(diacetylenes) is induced, in particular via free radical reactions, by appropriate activation of these sensitizers or sensitizer systems.

Abstract: Poly(heteroaromatics) are prepared by electrochemical polymerization, in particular anodic oxidation, of a monomeric heteroaromatic compound in an aqueous electrolyte solvent in which the monomeric heteroaromatic compound is dispersed, in the presence of a conductive salt and a dispersant. The films obtained by the process have good mechanical properties and high electrical conductivities.