In the multistage embodiment, the abovementioned evaporators are preferably bottom evaporators of a distillation column. A conventional flexible polyurethane foam, made using methylene diphenyl diisocyanate (MDI), having a bulk foam density in the range of 2.5 pounds per cubic foot or lower and having a foam hardness or IFD in the range of 10 to 90 lb/50 in 2.The present invention … 1992), the court overturned OSHA’s 1989 Air Contaminants Rule, including the Ref document number: One usually distinguishes three types of separating elements. The distillative separation can in principle be carried out in various devices. The condensation can be carried out technically both continuously and discontinuously. Packed columns can be filled with different packing, which cause a good distribution of the liquid and turbulence of the gas flow. The storage temperature controls the kinetics of the formation of uretdiones and uretonimines. "Storage" means in particular the temporary storage of a substance or mixture of substances for a period of at least 1 day. MDI reacts with polyols in the manufacture of polyurethane. The mass flow (6) was 0.79 kg / h. On stream (3k), a mixture of 47% by weight of 4,4'-MDI and 53% by weight of 2,4'-MDI was withdrawn. Subscribers to our Specialty Price Trends have access to price trend estimates for as many as 153 specialties, as well as an online specialty price estimator, through which current specialty prices can be easily calculated, using past prices. 1 was used. However, compound A is more preferably 4,4'-methylene diphenyl diisocyanate. The method according to one or more of claims 1 to 5, wherein the recycling of the stored mixtures F and / or P takes place in the context of a batch process, preferably when a content of at least 0.3 wt .-% uretdione calculated as dimeric Methylendiphenyldiisocyanat unit based on the total weight of the stored methylene diphenyl diisocyanate. Corresponding methods are described in EP 1475367 A1 in paragraphs [0024] to [0031]. 7. According to the invention, the storage of the mixture F or mixtures F obtained in step (c) and the mixture P obtained in step (b) is carried out in step (d), wherein a part of at least one of the stored mixtures F and / or P by means of recycling again in at least one of the steps (b) or (c) is used. The pilot phase should be completed in about 12 months’ time. Step (c). 11782610, Country of ref document: Before further processing, the methylene diphenyl diisocyanate products prepared in liquid form must be temporarily stored and / or stored. In a first stage, an acid-catalyzed condensation of aniline with formaldehyde is first carried out to produce the corresponding MDA mixture. As a result, future MDI production plants based on AdiP technology can be smaller than in the past. MarketsandResearch.biz has announced the addition of a new report entitled Global Pure Methylene Diphenyl Diisocyanate(Pure MDI) Market 2020 by Manufacturers, Regions, Type and Application, Forecast to 2025 A device for storage is any device that is provided for temporarily receiving the substance or mixture to be stored, for example, a container, in particular a storage tank. The formation of uretdiones is also uncatalyzed in aromatic isocyanates. The content in ppm in the context of the present invention generally refers to parts by weight based on the total weight of a mixture. 5,346,958, EP 0133538, JP 06345707, DD 288598, DD 288593, EP 0524507 and EP 0866057. The first quarter of 2020, COVID-19 spread in different global countries, affecting a large number aspect of Polymeric Methylene Diphenyl Diisocyanate market such as an unexpected pause in production process, financial and manufacturing activities in various business sectors. Detection Limits (mg/M3)a Examples of Manufacturing Processes Methylene Diphenyl Diisocyanate (MDI) 101-68-8 200 Pressed Board Production Headliner Production The embodiment with a second side take-off above the first side take-off is preferred, since in this way a high purity of the desired dinuclear isomers is obtained. The original technology-based rule, issued in 1998, controlled emission of methylene chloride, 2,4-toluene diisocyanate (TDI), methyl chloroform, methylene diphenyl diisocyanate (MDI), propylene oxide, diethanolamine, methyl ethyl ketone, methanol and toluene. Method according to one or more of claims 1 to 4, wherein the return of the stored mixtures F and / or P takes place in the context of a continuous process. A stream (4) containing a mixture of binuclear isomers of the M DI is fed to the column K2 (1). The effectiveness of the contacting is particularly dependent on a uniform, area-wide fluid task. "Storage" means the temporary storage of a substance or mixture for later use and / or removal. For this purpose, the liquid A must be distributed in a suitable manner. For example, the phosgenation can be carried out by a two-step reaction in the presence of at least one inert organic solvent, wherein the first stage of the phosgenation takes place in a static mixer and the second stage of the phosgenation in a residence time apparatus. Of course, the mixtures P and F obtained can be recycled independently of one another, in particular fed into different apparatus or used again in different process steps. The column was equipped with structured packings which had a low pressure drop. Step (b). Polyurethanes (PU) are polymers made with diisocyanates such as MDI (4,4'-methylene diphenyl diisocyanate) and TDI (2,4-toluene diisocyanate and 2,6-toluene diisocyanate).