Abstract: Vulcanizable, mercaptan- and/or xanthogen-disulfide-regulated polychloroprene rubber are produced by emulsion polymerization of chloroprene and, based on polymerizable monomer used, 0 to 30 parts by weight ethylenically unsaturated, other monomers copolymerizable with chloroprene in an alkaline medium by a process in which(1) 0.1 to 10 parts by weight of a tricyclic diterpene carboxylic acid containing at least two conjugated C.dbd.C double bonds per molecule, based on the polymerizable monomer used, and optionally(2) 0.1 to 5 parts by weight, based on polymerizable monomer used, fatty acid estersare used for their production.The polychloroprene produced in accordance with the invention may be used for the production of vulcanized rubber articles. The polychloroprene rubbers produced by the process according to the invention have a minimal tendency to foul metal molds. The pollution of wastewaters by the process according to the invention is minimal.

Abstract: This invention relates to mixtures of polychloroprene elastomers which are distinguished by their good processibility and excellent cold resistance.

Abstract: The polymerization of chloroprene leads to non-colored products when a mixture of 2.0 to 5.0% by weight of a salt of disproportionated abietic acid and 0.1 to 1.0% by weight, in each case relative to the total amount of monomer, of a compound of the formula ##STR1## in which R.sub.1 and R.sub.2, independently of one another, denote hydrogen or CH.sub.3,m denotes a number from 0 to 14,n denotes a number from 0 to 13,p denotes a number from 0 to 2, andy denotes hydrogen, Na or K, andthe total number of aliphatic carbon atoms is 11 to 15,is used as emulsifier, the emulsifiers having the advantage of being biologically degradable.

Abstract: The combination of unmodified resinic acids and direct peptization in the production of sulfur-modified polychloroprene leads to a favorable ratio of elasticity to viscosity.

Abstract: Toluene-soluble, sulphur-modified polychloroprene is obtained by emulsion copolymerization of chloroprene, sulphur and optionally further monomers which are copolymerizable with chloroprene and sulphur using a peroxy activator and subsequent working-up by stabilizing, stopping, degassing and isolating without separate peptization, in that polymerization is carried out in the presence of dithiocarbamates and/or xanthogenates and the activator is metered in continuously or batch-wise during the course of polymerization.

Abstract: The invention relates to a polychloroprene rubber which shows advantages over the prior art in the sum total of its performance properties, namely vulcanization rate, tensile strength, elongation at break, modulus, tear propagation resistance and thermal stability of the vulcanizate.

Abstract: Storage-stable polychloroprene is obtained, by aqueous emulsion polymerization, using xanthogen disulphides as molecular weight regulators, when a peptizing agent is added after the end of the polymerization.

Abstract: An improved process for the preparation of polychloroprene by the emulsion (co)polymerization of chloroprene and optionally other monomers capable of copolymerization with chloroprene, using a peroxo activator, and subsequent working up of the product by stopping the reaction, stabilizing, degassing and isolating the product, characterized in that polymerization is carried out in the presence of dithiocarbamates and/or xanthates and 0 to 0.5% by weight of sodium .beta.-anthraquinone sulphonate.

Abstract: Generation of monochromatic coherent electromagnetic radiation by application of Bose-Einstein condensation of electromagnetic radiation which is achieved by causing a sufficiently large, overcritical mean energy density of electromagnetic radiation in a suitable cavity for electromagnetic radiation.

Abstract: Gel-free polychloroprene is obtained, at high monomer conversions, using a polymerization initiator comprising sodium dithionite or a mixture of sodium dithionite with formamidinesulphinic acid or with potassium peroxydisulphate or with formamidinesulphinic acid and potassium peroxodisulphate or with potassium peroxodisulphate and sodium anthraquinon-.beta.-sulphonate or with formamidinesulphinic acid and potassium peroxodisulphate and sodium anthraquinone-.beta.-sulphonate, and in the presence of oxygen and a chain transfer agent when 30 to 90% of the initiator is present at the commencement of polymerization and the remainder is added in portions during the polymerization, only further sodium dithionite being added at a conversion >60% in the case of an initiator combination, and when 20 to 80% by weight of the total amount of chain transfer agents is present before or at the commencement of polymerization and the remaining amount is added in one or more parts at monomer conversions of greater than 20%.

Abstract: An elastomeric mass of polychloroprene sol and polychloroprene gel in proportions in the range of 95:5 to 25:75% by weight in which the polychloroprene sol is free from sulphur and the polychloroprene gel used is a sulphur-containing gel with xanthate or carbamate functions has better processing characteristics than the pure sol component without the expected deterioration in the mechanical properties of the vulcanisates prepared from the mass.

Abstract: Disclosed is a self-contained radiant unit in the form of a portal for use particularly as a drying and baking tunnel for the automobile industry which is equipped with a plurality of infrared lamps on its inner surfaces. Air inlet openings are provided in the roof and/or side walls of the portal, at least over the region midway along with their horizontal extension, for the turbulence-free removal of the vapors emanating from the surface of the object being treated as well as of suspended particles present in the drying and baking zone.

Abstract: Proposed is a method for the erection of structures, such as bridges, that display pre-fabricated concrete beams, according to which the individual pre-fabricated beams are produced, on the spot, on a feed rigging within the corresponding work area of the structure, in a heated and laterally tiltable form. After removal from the form, the thusly produced pre-fabricated beams are transferred sidewardly into their final position by means of gantry cranes. During concretizing of the individual pre-fabricated beams, flexure of the feed rigging carrying the form is equalized in continuous fashion, in correspondence with the progressing, concretizing process, by transfer pumping of ballast liquid.

Abstract: Proposed is a method for the erection of structures, such as bridges, that display pre-fabricated concrete beams, according to which the individual pre-fabricated beams are produced, on the spot, on a feed rigging within the corresponding work area of the structure, in a heated and laterally tiltable form. After removal from the form, the thusly produced pre-fabricated beams are transferred sidewardly into their final position by means of gantry cranes. During concretizing of the individual pre-fabricated beams, flexure of the feed rigging carrying the form is equalized in continuous fashion, in correspondence with the progressing, concretizing process, by transfer pumping of ballast liquid.

Abstract: Solid polychloroprene mixtures consisting of sol and gel polymer, wherein the sol component consists of a copolymer of chloroprene and from 0.75 to 0.32% by weight of sulphur, based on the total quantity of unsaturated compounds of the sol polychloroprene, and the gel component consists of a copolymer of chloroprene, from 0.4 to 1.0% by weight of sulphur, based on the total quantity of unsaturated compounds of the gel polychloroprene and from 7.5.times.10.sup.-3 to 3.0.times.10.sup.-2 mols, based on 100 g of the total quantity of monomer of the gel polychloroprene, of a compound corresponding to the general formula ##STR1## wherein R.sub.1 and R.sub.2 each represents a hydrogen atom or C.sub.1 -C.sub.4 alkyl group, and X represents a C.sub.2 -C.sub.10 alkylene group,are suitable for the production by extrusion and by calandering of rubber articles which may be subjected to high strains.

Abstract: Vulcanizable, elastomeric chloroprene/sulfur copolymers having viscosities of from 60 to 35 ME, strengths of greater than 20 MPa and sulfur contents of from about 0.3 to 0.45% by weight are obtained by polymerizing chloroprene in the presence of from 0.05 to 0.40% by weight of sulfur to form a latex I, polymerizing chloroprene in the presence of from 0.5 to 1.5% by weight of sulfur to form a latex II, mixing latices I and II, optionally together with other sulfur-modified polychloroprene latices, in a ratio of from 4:1 to 1:4 (based in each case on solids) and peptizing the mixture, followed by working up to form the solid rubber, the percentages quoted being based on the quantity of monomer.

Abstract: Vulcanisable, elastomeric chloroprene-sulphur copolymers having viscosities of from 60 to 35 MU, strengths of >20 MPa and sulphur contents of from about 0.5 to 0.7%, by weight, in the batch are obtained by polymerising chloroprene in the presence of from 0.10 to 0.35%, by weight, of sulphur to form a latex I, polymerising chloroprene in the presence of from 0.50 to 1.00% by weight, of sulphur to form a latex II, mixing latices I and II in a ratio of from 4:1 to 1:4 (based in each case on solids), optionally together with other sulphur-modified polychloroprene latices, the mixture is peptised and worked-up to form the solid rubber, the percentages quoted being based on the quantity of monomer.

Abstract: The properties of mortar and concrete are improved by the addition to the fresh mortar or concrete of an aqueous dispersion of a plastic obtained by the emulsion polymerization of olefinically unsaturated monomers, and of a polycondensate of formaldehyde and an amino-s-triazine modified with sulfite or sulfonic acid. A well-balanced relation between the compressive strength, the tensile strength in bending, and the adhesion to aged and hardened mortar or concrete is thus obtained.

Abstract: Process for the homopolymerisation and copolymerisation of conjugated dienes in inert organic solvents on alkali metal amides as catalysts in the presence of a solvating agent for the amide.