25686-28-6

Usage

Flammability and Explosibility

Notclassified

Upstream product

• 7450-63-7 dimethyl 4,4'-methylenebis(1,4-phenylene)diurethane 
• 10097-16-2 (methylenedi-4,1-phenylene)bis-carbamic acid diethyl ester 
• 60483-67-2 N,N'-(4,4'-methanediyl-di-phenyl)-bis-carbamic acid dipropyl ester 
• 75-44-5 phosgene 
• 1208-52-2 2,4'-diaminodiphenylmethane 
• 6582-52-1 2,2'-methylenedianiline 
• 101-77-9 4,4'-diamino diphenyl methane 
• 101-65-5 N,N'-(4,4'-methanediyl-di-phenyl)-bis-carbamic acid diphenyl ester 
• 67-56-1 methanol 
• 124-38-9 carbon dioxide 
• 59255-81-1 O,O'-di-tert-butyl 4,4'-methylenebis(4,1-phenylene)dicarbamate 
• 24731-90-6 N,N'-(4,4'-methanediyl-di-phenyl)-bis-carbamic acid diisopropyl ester 
• 20723-73-3 C₂₁H₁₈N₂O₄ 
• 216142-79-9 C₂₅H₃₆N₄O₂ 

Downstream Products

• 124161-58-6 N,N'-(4,4'-methanediyl-di-phenyl)-bis-carbamic acid bis-(2-trimethylammonio-ethyl ester); diiodide 
• 100914-59-8 chloro-bis-(4-isocyanato-phenyl)-methane 
• 56360-75-9 C₂₉H₃₀N₆O₂ 
• 21649-23-0 4,4'-Bis--diphenylmethan 
• 56360-74-8 C₂₁H₃₀N₆O₂ 
• 53050-39-8 C₂₁H₃₀N₆O₂ 
• 56360-76-0 C₂₁H₃₀N₆O₄ 
• 53050-40-1 C₂₁H₂₆N₆O₂ 
• 30094-81-6 C₂₇H₃₆N₂O₁₂P₂ 
• 16167-28-5 2-anilino-1,5-bis-[4-(4-isocyanato-benzyl)-phenyl]-3-methyl-[1,3,5,2]triazaborinane-4,6-dione 
• 56360-77-1 C₂₁H₂₆N₆O₆ 
• 63761-07-9 (CH₃NHC(O)NHC₆H₄)2CH₂ 
• 1421687-07-1 C₂₁H₂₈N₄O₆ 
• 80284-64-6 4,4’-diphenylmethane-bis(methyl)carbamate 

Relevant academic research and scientific papers

METHOD FOR PRODUCING CARBAMATE AND METHOD FOR PRODUCING ISOCYANATE

The present invention provides a method for producing a carbamate that includes a step (1) and a step (2) described below: (1) a step of producing a compound (A) having a urea linkage, using an organic primary amine having at least one primary amino group per molecule and at least one compound selected from among carbon dioxide and carbonic acid derivatives, at a temperature lower than the thermal dissociation temperature of the urea linkage; and(2) a step of reacting the compound (A) with a carbonate ester to produce a carbamate.

FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES

The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.

ISOCYANATE PRODUCTION METHOD

An isocyanate production method according to the present invention is a method in which an isocyanate is produced by subjecting a carbamate to thermal decomposition, and includes: a step of preparing a mixture liquid containing the carbamate, an inactive solvent and a polyisocyanate compound; a step of conducting a thermal decomposition reaction of the carbamate by continuously introducing the mixture liquid into a thermal decomposition reactor; a step of collecting a low-boiling decomposition product by continuously extracting the low-boiling decomposition product in a gaseous state from the reactor, the low-boiling decomposition product having a boiling point lower than the polyisocyanate compound; and a step of collecting a high-boiling component by continuously extracting, from the reactor, a liquid phase component which is not collected in a gaseous state at the step of collecting the low-boiling decomposition product.

Method for preparing diphenylmethane diisocyanate through efficient catalysis by polyoxometallate

The invention discloses a method for preparing 4,4'-diphenylmethane diisocyanate from 4,4'-diaminodiphenylmethane and methanol under the catalysis of a polyoxometallate (wherein the polyoxometallate is one of six basic configurations of a Keggin type, a Wells-Dawson type, a Lindeqvist type, a Waugh type Anderson type and a Silverton type, and the Anderson type configuration is mainly adopted). Themethod comprises the following specific steps: adding M-Anderson type heteropolyacid (M is Mn, Fe, Al, Cr, Co, Ni, Cu, Zn and the like) as a catalyst, 4,4'-diaminodiphenylmethane, methanol, hydrogenperoxide, an acid-binding agent, a dehydrating agent and an anhydrous acetonitrile solvent into a clean reaction tube; and finally sleeving an oxygen ball above a reactor, and carrying out a completestirring reacting for a period of time by air magnetic force at a certain temperature to obtain a target compound. According to the method disclosed by the invention, M-Anderson type heteropolyacid isused as the catalyst, and the catalyst has extremely high reaction activity, takes common non-noble metals as the center, further has popularization and utilization values and can be recycled after simple treatment, so that the cleanness of industrial reaction is improved, and the environmental protection pressure is reduced.

Preparation method for diphenylmethane diisocyanate

The invention provides a preparation method for diphenylmethane diisocyanate. The preparation method comprises a step of subjecting diphenylmethane dicarbamate to a pyrolysis reaction in an inert solvent having a boiling point lower than the boiling point of diphenylmethane diisocyanate in the presence of a catalyst so as to produce diphenylmethane diisocyanate. The preparation method provided bythe invention has the advantages of high reaction conversion rate, high yield, simple equipment and process and mild reaction conditions, and can meet the demands of industrial production.

Preparation method 4, 4' diphenyl methane diisocyanate (by machine translation)

The invention relates to 4. In 4 'diphenyl methane diisocyanate preparation method, catalyst polyoxometallate, solvent are added to the reaction vessel, raw materials 4, 4' - diaminodiphenylmethane and benzene silane, acid binding agent and dehydrating agent, are uniformly mixed, and gaseous carbon dioxide, which is stirred sufficiently at certain temperature, is added to obtain the product. M-Anderderson type heteropoly acid is adopted as a catalyst, and the catalyst needs mild reaction conditions, and is high in specificity and high, and is high in specificity. The recyclable environment-friendly, recyclable and environmentally friendly, improves the cleanliness, improves the process economy, reduces the manufacturing cost and the generation, reduces the environment-friendly pressure, and is beneficial to industrial production. (by machine translation)

Mechanistic Study of Stress Relaxation in Urethane-Containing Polymer Networks

Cross-linked polymers are used in many commercial products and are traditionally incapable of recycling via melt reprocessing. Recently, tough and reprocessable cross-linked polymers have been realized by incorporating cross-links that undergo associative exchange reactions, such as transesterification, at elevated temperatures. Here we investigate how cross-linked polymers containing urethane linkages relax stress under similar conditions, which enables their reprocessing. Materials based on hydroxyl-terminated star-shaped poly(ethylene oxide) and poly((±)-lactide) were cross-linked with methylene diphenyldiisocyanate in the presence of stannous octoate catalyst. Polymers with lower plateau moduli exhibit faster rates of relaxation. Reactions of model urethanes suggest that exchange occurs through the tin-mediated exchange of the urethanes that does not require free hydroxyl groups. Furthermore, samples were incapable of elevated-temperature dissolution in a low-polarity solvent (1,2,4-trichlorobenzene) but readily dissolved in a high-polarity aprotic solvent (DMSO, 24 to 48 h). These findings indicate that urethane linkages, which are straightforward to incorporate, impart dynamic character to polymer networks of diverse chemical composition, likely through a urethane reversion mechanism.

Fluoride-Catalyzed Deblocking: A Route to Polymeric Urethanes

We report a fluoride-catalyzed deblocking of urethanes as “blocked” isocyanates. Organic and inorganic sources of fluoride ion proved effective for deblocking urethanes and for converting polyurethanes to small molecules. Distinct from conventional deblocking chemistry involving organometallic compounds and high temperatures, the method we describe is metal-free and operates at or slightly above room temperature. The use of fluorescent blocking agents enabled visual and spectroscopic monitoring of blocking/deblocking reactions, and the selected conditions proved applicable to urethanes containing a variety of blocking groups. The method additionally enabled a one pot deblocking and polymerization with α,ω-diols. Overall, this deblocking/polymerization strategy offers a convenient and efficient solution to problems that have limited the breadth of applications of polyurethane chemistry.

Ionic liquid-mediated solvothermal synthesis of 4,4′-methylenediphenyl diisocyanate (MDI): An efficient and environment-friendly process

4,4′-Methylenediphenyl diisocyanate (4,4′-MDI) is an immensely important intermediate employed in the manufacturing of polyurethanes. Many synthetic routes have been developed over the decades for the synthesis of 4,4′-MDI compounds on a large scale; these compounds are highly toxic and hazardous in nature. In this study, an environment-friendly route is proposed for the synthesis of 4,4′-MDI using 4,4′-diaminodiphenylmethane and dimethyl carbonate (DMC) as starting materials, which are nontoxic in nature. The synthesis of ionic liquids (ILs) and their utilization in the decomposition reaction are systematically investigated. Imidazole-functionalized ionic liquids were prepared for the synthesis of 4,4′-MDI, and their thermal performances were evaluated by TGA. We found that in comparison with other imidazole-functionalized ionic liquids, 1-ethoxycarbonylmethyl-3-methylimidazolium tetrafluoroborate ([EAmim]BF4) exhibited preferable thermal activity for the decomposition of 4,4′-methylenediphenyl dimethylcarbamate (4,4′-MDC). Moreover, these ILs were more effective when they were combined with zinc as a catalyst, which enhanced the decomposition of MDC. Under optimal conditions, the yield of MDI compared to that of Zn(OAc)2-[EAmim]BF4 catalyst increased up to 96%. The mechanism of the enhanced performance of ionic liquids by catalytic activity of zinc acetate was also investigated.

Preparing method of MDI

The invention discloses a preparing method of MDI. The method comprises the steps of dissolving diphenylmethane toluene diamine in an organic solvent, introducing acid gas into the solvent to salify, conducting phosgenation reaction on the solvent under the action of a catalyst to obtain a MDI solution, and then conducting distilling, desolventizing and rectification on the MDI solution to obtain MDI with a high purity. According to the method, a phosgenation method is adopted to prepare MDI, firstly diphenylmethane toluene diamine is made into hydrochloride, and thus the situation that isocyanate and acyl chloride generated in the photochemical reaction react with amine again and generate a polymer compound is avoided; meanwhile, the catalyst is added, thus the reaction temperature is lowered and the reaction rate is quickened; in addition, gradient temperature raising is adopted to conduct the photochemical reaction, thus the disadvantages that in a traditional phosgenation method, side reactions are easily generated when the temperature is too high, and the reaction time is too long when the temperature is too low are avoided, not only the production phase is shortened, but also MDI with high purity can be obtained. According to the preparing method of MDI, MDI monomer can be directly obtained in the photochemical reaction, and purified MDI can be obtained without flow separating.