Abstract: A process and device are disclosed for manufacturing foam moldings. The parting plane of the mold has a circumferential vacuum channel, the top mold half has a suction channel for quickly evacuating the mold and self-closing expansion channels are arranged at the highest points of the inner cavity of the mold.

Abstract: Azeotropic compositions made up of (a) from about 4 to about 50% by weight 1,3-dioxolane and (b) one compound selected from (1) about 75 to about 96% by weight cyclopentane, (2) about 60 to about 79% by weight 2-methyl pentane, (3) about 59 to about 77% by weight 3-methyl pentane, and (4) about 50 to about 69% by weight n-hexane in which the sum of the weight percent of (a) plus weight percent of (b) is approximately 100 percent are used as blowing agents in the production of polyurethane/polyurea foams.

Abstract: A mixture of materials having different boiling points is separated into fractions having different boiling points. The separated fraction containing the desired product is stripped using the vapors of a lower boiling fraction. The process of the present invention is particularly useful for recovering a desired isomer or isomer mixture from a technical mixture obtained during production of an aromatic amine such as toluenediamine. Little or no unwanted isomer or by-product is present in the isomer or isomer mixture product of this process.

Abstract: A process for concentrating spent sulphuric acids particularly sulphuric acids which arise during the nitration of hydrocarbons with nitric acid in the presence of sulphuric acid, wherein single- or multi-stage concentration is effected under vacuum.

Abstract: In accordance with the invention, a reinforcing agent is added to the polyol side before the Reaction Injection Molding (RIM) process. The agent of the invention comprise particulate flakes which are characterized by their fine particle size and high aspect ratio. It was surprisingly found that the incorporation of the agent of the invention in the RIM process yields molded parts with a good combination of properties including flexural and tensile modulus heat sag and reduction in the coefficient of linear thermal expansion and high Distinctness Of Image (DOI) values.

Abstract: A vacuum panel composed of two foam slabs positioned one on top of the other which slabs are covered with a film in which the panel has been evacuated and sealed with a gas-tight seal. One of the foam slabs is an open-pored polystyrene foam. The other foam slab is an open-pored polyurethane foam. These vacuum insulating panels are useful for the production of insulating elements that are used as external walls in refrigerators.

Abstract: The reactivity of isocyanate formulations is controlled by including a chain extender corresponding to the formula HO—R1—NR2—X—NR3—R4—OH  (I) in which R1, R2, X, R3 and R4 represent specified groups is included in the isocyanate formulation.

Abstract: An in-line spectrometric method for determining the distillation residue content in an opaque, dark-colored mixture containing an isocyanate and tar-like materials (residue) during the isocyanate production process. A probe capable of directing light at wavelengths of from 1050 to 2150 nm is inserted in a stream of the residue-containing mixture and light is transmitted through the stream. Light absorption data is collected and a near-infrared spectrum is generated. The residue content is then determined using a chemometric model. Knowledge of the residue content makes it possible to control and optimize the distillation process.

Abstract: Molded, soft composite articles such as seat cushions are made by (a) applying a composition which forms a soft elastomer to all interior walls of an open mold, (b) introducing a composition which will react to form a low density, high resiliency, flexible foam under molding conditions into the mold in a manner such that the foam-forming composition will be substantially completely within the elastomer-forming composition; (c) closing the mold (i) prior to introduction of the foam-forming composition or (ii) at some point during or subsequent to introduction of the foam-forming mixture but before foam formation is completed and (d) allowing the foam-forming mixture to form a foam. The composite articles produced by this simple one-step process are characterized by good cushioning characteristics, good abrasion resistance and good mold reproducibility. This molding process generates less waste and requires less labor and equipment than current commercial processes.

Abstract: A process is described for obtaining pure isocyanate isomers from a mixture of isocyanate isomers by suspension crystallization and the isolation of isomerically pure crystals, which is characterized in that, prior to the isolation of the crystals, 5 to 40% by weight of the crystals produced are remelted while simultaneously increasing the temperature of the crystal slurry by 4.5 to 9° C.

Abstract: An isocyanate-reactive composition containing a blowing agent that is generally a gas at ambient temperature and pressure which is storage stable is produced by including a phenol or alkylphenol having at least one phenolic hydroxyl group in the isocyanate-reactive composition in an amount sufficient to promote the solubility of the blowing agent. The isocyanate-reactive composition may be stored at ambient conditions rather than under pressure. The isocyanate-reactive composition containing blowing agent may be used to produce foams having good physical properties after storage at ambient temperature and pressure for periods as long as 3 months.

Abstract: A method for making an energy-absorbing foam with polyurethane fillers that produces an energy-absorbing foam with properties that are comparable to a foam made without fillers.

Abstract: Dinitrotoluene is produced by nitrating toluene with nitrating acid under adiabatic conditions in a manner such that some mononitrotoluene is present in reaction mixture. The nitration reaction mixture is then treated to remove at least 5% by weight of water before the reaction mixture is separated into an acid phase and an organic phase. The product dinitrotoluene is recovered from the organic phase. The acid phase may be recycled after nitric acid has been added to replace that which was used in the nitration reaction.

Abstract: A process for producing a mixture of isomers of dinitronaphthalene by nitration of nitronaphthalene, in which nitronaphthalene, optionally in an inert organic solvent, is reacted with 1 to 20 times the equivalent quantity, based on the quantity of nitronaphthalene, of 50% to 100% nitric acid in the presence of a solid, perfluorinated, strongly acidic ion exchanger.

Abstract: A continuous process for the preparation of aromatic di- and/or polyamines by catalytic hydrogenation of the corresponding aromatic di- and/or polynitro compounds with hydrogen, characterized in that, in a reactor with a catalytic fixed bed or trickle bed at a pressure between 5 and 100 bar and a reaction temperature of from 100 to 220° C. a) the aromatic di- and/or polynitro compounds, optionally in the presence of a solvent, are introduced into a product stream comprising essentially recycled hydrogenated product, water and hydrogen, and b) a part of the product stream is removed continuously from the reactor system.

Abstract: The invention relates to a process for the electrolysis of sodium chloride-containing brine with parallel operation of amalgam electrolysis units (5) and membrane electrolysis units (4) with a common brine circuit using a mercury-resistant oxygen consumable cathode in the membrane electrolysis unit (4).

Abstract: A process for rapidly mixing phosgene and an amine in the gas phase to produce the corresponding isocyanate. Micro-structure mixers are used for the rapid mixing. The educts emerge from the micro-structure mixer in the form of thin free jets which mix very rapidly by diffusion and/or turbulence. As a result, the mixing operation is accelerated substantially as compared with conventional reactors. The isocyanate yield is also increased.

Abstract: A process for the purification of organic isocyanates or isocyanate mixtures in which the amount of chlorine compound(s) present is reduced by mixing the isocyanate(s) or isocyanate mixtures with a gel-type or macroporous, anion-exchanging organic material having tertiary and/or quaternary amino groups. The process renders possible a purification of the isocyanates from chlorine-containing compounds which is milder than in conventional processes and is therefore particularly suitable for temperature-sensitive isocyanates.

Abstract: Compositions made up of an aromatic polyisocyanate and a polyester having an average molecular weight of from about 600 to about 5000, obtainable by self-condensation of ricinoleic acid, optionally with co-utilization of a C2-C20 starter polyol and optional additives. These compositions are useful as binders for the production of composite materials.

Abstract: Improved double metal cyanide (DMC) catalysts are disclosed. The catalysts comprise a DMC compound, an organic complexing agent, from about 0.1 to about 10 wt. % of an organophosphine oxide, and optionally, a polyether. Compared with other DMC catalysts prepared in the absence of the organophosphine oxide, those of the invention have higher activity for epoxide polymerization, and they give polyols having reduced unsaturation even at high epoxide polymerization temperatures.