- 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.
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Paragraph 0367; 0369-0379; 0399; 0402-0403
(2021/06/22)
-
- 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.
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Paragraph 0175; 0185-0187; 0325; 0330-0335
(2021/06/22)
-
- 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.
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Paragraph 0419-0430; 0447-0451; 0454-0458; 0462
(2020/05/02)
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- 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.
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Paragraph 0023-0024; 0025-0026; 0027-0028; 0029-0044
(2020/11/09)
-
- 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.
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Paragraph 0036-0079; 0086-0087
(2019/11/19)
-
- 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)
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Paragraph 0027-0058
(2019/10/01)
-
- 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.
- Brutman, Jacob P.,Fortman, David J.,De Hoe, Guilhem X.,Dichtel, William R.,Hillmyer, Marc A.
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p. 1432 - 1441
(2019/02/24)
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- 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.
- Sheri, Madhu,Choudhary, Umesh,Grandhee, Sunitha,Emrick, Todd
-
supporting information
p. 4599 - 4602
(2018/03/28)
-
- 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.
- Duan,You,Liu,Ma,Zhou,Zhang,Zhang
-
p. 12243 - 12255
(2018/07/24)
-
- 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.
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-
Paragraph 0019
(2017/08/28)
-
- Syntheses of isocyanates via amines and carbonyl fluoride
-
Isocyanates are widely used in many different areas, but the most common synthesis route-phosgene route cannot fit the more and more rigorous restriction of safety and environment. Here, a facile synthesis method of isocyanates via amines and carbonyl fluoride is proven feasibly by expanding its applications to the syntheses of nine different isocyanates. And two differences with the phosgene route are proposed. The reaction could occur under milder conditions and afford isocyanates in good yields, especially for the isocyanates containing electron withdrawing groups. It is appealing for industrial application.
- Quan, Hengdao,Zhang, Ni,Zhou, Xiaomeng,Qian, Hua,Sekiya, Akira
-
-
- BIOLOGICAL SYNTHESIS OF P-AMINOBENZOIC ACID, P-AMINOPHENOL, N-(4-HYDROXYPHENYL)ETHANAMIDE AND DERIVATIVES THEREOF
-
The invention generally relates to biological engineering of microorganisms and production of chemical compounds therefrom. More particularly, the invention relates to novel genetically engineered microorganisms for the fermentative production of p-aminobenzoic acid and related compounds from fermentable carbon substrates. The biologically derived PABA and related compounds from fermentable carbon substrates can be used in a number of applications including as a food supplement or raw materials for the syntheses of other industrial chemicals or polymers.
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Page/Page column
(2015/01/06)
-
- Solvent-free thermal decomposition of methylenediphenyl di(phenylcarbamate) catalyzed by nano-Cu2O
-
Methylene di(phenylisocyanate) (MDI) was prepared by thermal decomposition of methylenediphenyl di(phenylcarbamate) (MDPC) under solvent-free conditions with a nano-Cu2O catalyst. The preparation of nano-Cu2O was investigated in deta
- Wang, Qingyin,Kang, Wukui,Zhang, Yi,Yang, Xiangui,Yao, Jie,Chen, Tong,Wang, Gongying
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p. 548 - 558
(2013/08/25)
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- PROCESSES FOR PRODUCING ARYL CARBAMATES, ISOCYNATES AND POLYUREAS USING DIARYL CARBONATE
-
A preparation of aryl carbamates can be achieved readily by carbonylation of an aromatic polyamine compound with diphenyl carbonate (DPC) using a combination of an organic acid and a tertiary amine as a catalyst. Aryl carbamate can be converted into 4,4′-diphenylmethane diisocyanate (MDI) by heating it at about 200 to about 230° C. in a non-polar solvent containing inhibitor such as benzoyl chloride. In another application, trans-ureation of biscarbamates with an amine or mixed amines is found to be extremely facile in a polar solvent such as dimethyl sulfoxide (DMSO) and tetramethylene sulfone (TMS) in absence of any catalyst to make polyurea polymers of high molecular weights. Thus, efficient green-chemistry processes based on biscarbamates in making isocyanate products as well as urea prepolymers, urea elastomers and urea plastics have been developed in all in excellent yields without using reactive phosgene or 4,4′-diphenylmethane diisocyanate separately in the trans-ureation polymerizations.
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Paragraph 0111-0114
(2013/04/10)
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- PROCESS FOR THE PRODUCTION OF POLYISOCYANATES
-
The invention provides a multistage process for continuously preparing organic polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic polyamines with carbonic acid derivatives and alcohols into monomeric polyurethanes of low molecular mass, and the dissociation of said polyurethanes. The invention further provides an associated preparation process in which at certain reaction stages the polyisocyanates prepared and unutilizable residues are removed and reusable by-products and intermediates are recycled to preliminary stages.
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Page/Page column 7
(2013/02/28)
-
- PROCESS FOR PRODUCING ISOCYANATES USING DIARYL CARBONATE
-
An object of the present invention is to provide a process that enables isocyanate to be produced stably over a long period of time and at high yield without encountering problems of the prior art during production of isocyanate without using phosgene. The present invention provides an isocyanate production process including the steps of: obtaining a reaction mixture containing an aryl carbamate having an aryl group originating in a diaryl carbonate, an aromatic hydroxy compound originating in a diaryl carbonate, and a diaryl carbonate, by reacting a diaryl carbonate and an amine compound in the presence of a reaction solvent in the form of an aromatic hydroxy compound; transferring the reaction mixture to a thermal decomposition reaction vessel; and obtaining isocyanate by applying the aryl carbamate to a thermal decomposition reaction, wherein the reaction vessel in which the reaction between the diaryl carbonate and the amine compound is carried out and the thermal decomposition reaction vessel for the aryl carbamate are different.
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Page/Page column 39
(2011/04/14)
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- PROCESS FOR PRODUCING ISOCYANATE USING DIARYL CARBONATE
-
An object of the present invention is to provide a process that enables isocyanate to be produced stably over a long period of time and at high yield without encountering problems of the prior art during production of isocyanate without using phosgene. The present invention provides an isocyanate production process including the steps of: obtaining a reaction mixture containing an aryl carbamate having an aryl group originating in a diaryl carbonate, an aromatic hydroxy compound originating in a diaryl carbonate, and a diaryl carbonate, by reacting a diaryl carbonate and an amine compound in the presence of a reaction solvent in the form of an aromatic hydroxy compound; transferring the reaction mixture to a thermal decomposition reaction vessel; and obtaining isocyanate by applying the aryl carbamate to a thermal decomposition reaction, wherein the reaction vessel in which the reaction between the diaryl carbonate and the amine compound is carried out and the thermal decomposition reaction vessel for the aryl carbamate are different.
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Page/Page column 50
(2011/02/18)
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- PROCESS FOR THE PREPARATION OF N-SUBSTITUTED CARBAMIC ACID ESTER AND PROCESS FOR THE PREPARATION OF ISOCYANATE USING THE N-SUBSTITUTED CARBAMIC ACID ESTER
-
The present invention provides a method for producing N-substituted carbamic acid-O-aryl ester derived from a compound having an ureido group, the method comprising the step of carrying out esterification or esterification and transesterification from the compound having the ureido group and a hydroxy composition containing one type or a plurality of types of hydroxy compounds.
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-
-
- METHOD FOR PREPARING ISOCYANATES BY LIQUID-PHASE THERMAL CRACKING
-
The present invention discloses a method for preparing isocyanates by liquid-phase catalytic thermal cracking. In this method, in a reaction-rectification thermal cracking reactor, using a catalyst composition comprising a superfine powder metal oxide catalyst and an ionic liquid, an alkyl or aryl dialkylurethane, or multialkylurethane being a reactant is liquid-phase thermal cracked for a reaction time of 0.5-3 h under a reaction temperature of 160-220° C. and an absolute pressure of 1000-8000 Pa so as to prepare the corresponding isocyanate. The invention has the characteristics of low thermal cracking temperature, high yield of target products, relatively simple reaction apparatus and good universality for substrates (the yields of HDI, MDI, TDI, HMDI, NDI and IPDI or the like are all >85%) and the like.
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Page/Page column 4
(2011/02/18)
-
- PROCESS FOR PREPARING AROMATIC ISOCYANATES
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The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the liquid phase, if appropriate in the presence of at least one inert medium, in which the amine and the phosgene are first mixed in a mixing chamber (1) to give a reaction mixture and the reaction mixture is fed to a reactor, the amine being added through an orifice (3) arranged coaxially to the mixing chamber (1) and the phosgene being added through feed orifices (5) in at least two planes (7, 9) arranged at right angles to the axis (11) of the mixing chamber (1), or the phosgene being added through the orifice (3) arranged coaxially to the mixing chamber and the amine through the feed orifices (5) in at least two planes (7, 9) arranged at right angles to the axis (11) of the mixing chamber (1). At least one plane (9) is arranged upstream and at least one plane (7) downstream of the orifice (3) arranged coaxially to the mixing chamber (1) in main flow direction of the reaction mixture. The mean residence time of the reaction mixture in the mixing chamber (1) is not more than 20 ms.
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Page/Page column 4
(2011/10/19)
-
- PROCESS FOR PRODUCING ISOCYANATE
-
An object of the present invention is to provide a process that enables isocyanate to be produced stably over a long period of time and at high yield without encountering problems of the prior art during production of isocyanate without using phosgene. The present invention discloses a process for producing an isocyanate by subjecting a carbamic acid ester to a thermal decomposition reaction, including the steps of: recovering a low boiling point component in a form of a gaseous phase component from a thermal decomposition reaction vessel in which the thermal decomposition reaction is carried out; recovering a liquid phase component containing a carbamic acid ester from a bottom of the thermal decomposition reaction vessel; and supplying all or a portion of the liquid phase component to an upper portion of the thermal decomposition reaction vessel.
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Page/Page column 49-50
(2011/02/18)
-
- ISOCYANATE PRODUCTION PROCESS
-
An object of the present invention is to provide a process that enables isocyanate to be produced stably over a long period of time and at high yield without encountering problems of the prior art during production of isocyanate without using phosgene. The present invention discloses a process for producing an isocyanate by subjecting a carbamic acid ester to a thermal decomposition reaction, including the steps of: recovering a low boiling point component in a form of a gaseous phase component from a thermal decomposition reaction vessel in which the thermal decomposition reaction is carried out; recovering a liquid phase component containing a carbamic acid ester from a bottom of the thermal decomposition reaction vessel; and supplying all or a portion of the liquid phase component to an upper portion of the thermal decomposition reaction vessel.
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Page/Page column 40
(2011/05/03)
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- METHOD FOR PRODUCTION OF ISOCYANATE USING COMPOSITION COMPRISING CARBAMIC ACID ESTER AND AROMATIC HYDROXY COMPOUND, AND COMPOSITION FOR TRANSPORT OR STORAGE OF CARBAMIC ACID ESTER
-
An object of the present invention is to provide an isocyanate production process, which is free of the various problems found in the prior art, and which uses a composition containing a carbamic acid ester and an aromatic hydroxy compound when producing isocyanate without using phosgene, as well as a carbamic acid ester composition for transferring or storing carbamic acid ester. The present invention discloses an isocyanate production process including specific steps and using a composition containing a carbamic acid ester and an aromatic hydroxy compound, as well as a composition for transfer or storage of carbamic acid ester comprising the carbamic acid ester and the specific aromatic hydroxy compound.
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Page/Page column 69
(2010/02/17)
-
- COSMETIC OR DERMATOLOGICAL COMPOSITION COMPRISING A POLYMER BEARING JUNCTION GROUPS, AND COSMETIC TREATMENT PROCESS
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The present patent application relates to a cosmetic or dermatological composition comprising, in a cosmetically or dermatologically acceptable medium, a polymer comprising: (a) a polymer backbone that may be obtained by reaction: of a polyol comprising 3 to 6 hydroxyl groups;of a monocarboxylic acid containing 6 to 32 carbon atoms;of a polycarboxylic acid comprising at least two carboxylic groups COOH, and/or of a cyclic anhydride such as a polycarboxylic acid and/or of a lactone comprising at least one carboxylic group COOH; and(b) at least one junction group linked to the said polymer backbone and capable of establishing H bonds with one or more partner junction groups, each pairing of a junction group involving at least three H (hydrogen) bonds. The patent application also concerns a cosmetic treatment process using the said composition.
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-
-
- PROCESS FOR PRODUCING DIAMINES AND POLYAMINES OF THE DIPHENYLMETHANE SERIES
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The present invention relates to a process for producing diamines and polyamines of the diphenylmethane series (MDA) by reacting aniline and formaldehyde in the presence of an acid catalyst, wherein the aniline contains in total less than 0.5 wt. %, based on the total weight of aniline, of one or more compounds which contain at least one carbonyl group or of one or more compounds that are formed by reaction of these compounds which contain at least one carbonyl group with aniline.
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Page/Page column 6-7
(2009/10/01)
-
- METHOD FOR PRODUCING ISOCYANATES
-
The invention provides a process for preparing isocyanates by reacting amines with phosgene, wherein the amine or a mixture of amine and a solvent is mixed in the form of an aerosol with gaseous phosgene and the amine is subsequently reacted with phosgene.
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Page/Page column 3-4
(2009/12/04)
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- PROCESS FOR PRODUCING ISOCYANATE
-
An object of the present invention is to provide a process allowing long-term, stable production of isocyanates at a high yield without the various problems found in the prior art during production of isocyanates without using phosgene. The present invention discloses a process for producing an isocyanate by subjecting a carbamic acid ester to a decomposition reaction in the presence of a compound having an active proton and a carbonic acid derivative.
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Page/Page column 53
(2009/09/05)
-
- METHOD FOR PRODUCING ISOCYANATE
-
An object of the present invention is to provide a process that enables isocyanates to be stably produced over a long period of time at high yield without encountering various problems as found in the prior art when producing isocyanates without using phosgene. The present invention discloses a process for producing an isocyanate, comprising the steps of: reacting a carbamic acid ester and an aromatic hydroxy compound to obtain an aryl carbamate having a group derived from the aromatic hydroxy compound; and subjecting the aryl carbamate to a decomposition reaction, wherein the aromatic hydroxy compound is an aromatic hydroxy compound which is represented by the following formula (1) and which has a substituent R1 at at least one ortho position of a hydroxyl group: (wherein ring A represents an aromatic hydrocarbon ring in a form of a single or multiple rings which may have a substitute and which have 6 to 20 carbon atoms; R1 represents a group other than a hydrogen atom in a form of an aliphatic alkyl group having 1 to 20 carbon atoms, an aliphatic alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or an aralkyloxy group having 7 to 20 carbon atoms, the group containing an atom selected from a carbon atom, an oxygen atom and a nitrogen atom; and R1 may bond with A to form a ring structure).
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Page/Page column 41
(2009/09/05)
-
- Aqueous Dispersions Of Polyorganosiloxanes Containing Urea Groups
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Polyorganosiloxanes containing urea groups can be obtained in the form of aqueous dispersions by firstly dissolving them in an organic solvent, then dispersing this solution with water with co-use of auxiliaries, subjecting the mixture to homogenization and then at least partially removing the organic solvent. The aqueous dispersions prepared in this way are suitable as additive for detergents, fabric softeners, haircare compositions, shampoos and for textile finishing.
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-
-
- Comparison of base-promoted and self-catalyzed conditions in the synthesis of isocyanates from amines using triphosgene
-
Comparison of base-promoted and self-catalyzed conditions for the synthesis of isocyanates from amines and triphosgene shows no advantage in using an amine base in the majority of cases. The workup and isolation of the product is simplified under base-free conditions. Yields of between 50 and 90% after distillation were common. Only acid-sensitive substrates need a base catalyst. Copyright Taylor & Francis Group, LLC.
- Charalambides, Yiannis C.,Moratti, Stephen C.
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p. 1037 - 1044
(2007/10/03)
-
- Process for the production of 4,4'-diphenylmethane diisocyanate
-
The present invention relates to a process for the production of 4,4′-diphenylmethane diisocyanate (4,4′-MDI) by acid-catalyzed condensation of aniline with formaldehyde, reaction of the mixtures of di- and polyamines obtained with phosgene to form the corresponding mixture of MDI isomers and homologues (di- and polyisocyanates of the diphenylmethane series) and subsequent separation of the mixture by distillation to form 4,4′-MDI and polymeric MDI.
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Page/Page column 3-4
(2008/06/13)
-
- Process for the production of isocyanates
-
Isocyanates, preferably diisocyanates and polyisocyanates of the diphenylmethane series (MDI), are produced by reaction of amines dissolved in a solvent with phosgene in the same solvent to form the corresponding isocyanates. Hydrogen chloride and excess phosgene are subsequently removed from the reaction mixture to obtain a crude isocyanate-containing solution. Subsequently, the crude isocyanate-containing solution is separated by distillation into isocyanates and solvent. The solvent is recycled and used for the production of solutions of the amines and of phosgene. The solvent being recycled is treated to reduce the phosgene and diisocyanate contents before being used for the production of the solution of the amine.
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Page/Page column 4-5
(2008/06/13)
-
- Process for the preparation of 4,4'-diphenylmethane diisocyanate
-
4,4'-diphenylmethane diisocyanate is produced at two different sites by a) reacting aniline and formaldehyde in the presence of an acid catalyst to produce a mixture of diamines and polyamines of the diphenylmethane series at a first production site, b) these diamines and polyamines are then reacted with phosgene to give the corresponding diisocyanates and polyisocyanates of the diphenylmethane series, which may optionally be separated by distillation to give a mixture of diisocyanates and polyisocyanates containing from 50 to 80 wt.% of 4,4'-diphenylmethane diisocyanate, from 1 to 12 wt.% of 2,4'- and/or 2,2'-diphenylmethane diisocyanate taken together, and from 10 to 45 wt.% of trifunctional and higher-functional polyisocyanates, based on the weight of the mixture of diisocyanates and polyisocyanates, c) transferring the mixture of diisocyanates and polyisocyanates to transport containers and transporting these isocyanate-containing containers to a second production site remote from the first, and d) separating the mixture of diisocyanates and polyisocyanates by distillation and/or crystallization to give a pure 4,4'-diphenylmethane diisocyanate containing at least 97 wt.% of 4,4'-diphenylmethane diisocyanate and a maximum of 3 wt.% of 2,4'-diphenylmethane diisocyanate.
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Page/Page column 5-6
(2008/06/13)
-
- Process for distilling a mixture of isomeric diisocyanatodiphenylmethanes
-
Preparation of 2,4'-methylene diphenylene diisocyanate (MDI) comprises distillation of a diisocyanatodiphenylmethane isomer mixture from 2,2'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane and 4,4'-diisocyanatodiphenylmethane to give a mixture comprising 2,4'-diisocyanatodiphenylmethane (85-99 wt.%), 4,4'-diisocyanatodiphenylmethane (up to 15 wt.%) and 2.2'-diisocyanatodiphenylmethane (up to 0.2 wt.%). Preparation of 2,4'-methylene diphenylene diisocyanate (MDI) (with less production of 2,4'-MDI) comprises distillation of a diisocyanatodiphenylmethane isomer mixture from 2,2'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane and 4,4'-diisocyanatodiphenylmethane to give a mixture comprising 2,4'-diisocyanatodiphenylmethane (85-99 wt.%), 4,4'-diisocyanatodiphenylmethane (up to 15 wt.%) and 2.2'-diisocyanatodiphenylmethane (up to 0.2 wt.%) (where: distillation is carried out in a single-step; a partition column is used in at least one distillation stage; a destillative before separation is upstreamed to the partition column before distillation to give a mixture (comprising 2,2'-diisocyanatodiphenylmethane (0-15 wt.%), 2,4'-diisocyanatodiphenylmethane (12-60 wt.%) and 4,4'-diisocyanatodiphenylmethane (25-88 wt.%)), which is used as feed stream to the partition column; and the vapor at the top of the partition column is condensed and 98-99.6% of it returns to the top zone).
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Page/Page column 5-6
(2008/06/13)
-
- Process for the preparation of mixtures of di- and polyisocyanates of the diphenylmethane series with a high amount of 4,4'-methylenediphenyldiisocyanate and 2,4'-methylenediphenyldiisocyanate
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A fraction of diisocyanates of the diphenylmethane series is produced by reacting aniline and formaldehyde in the presence of an acid catalyst; phosgenating diamines and polyamines of diphenylmethane series containing binuclear methylenediphenyl diamine to produce a crude diisocyanate and polyisocyanate; and separating from crude diisocyanate and polyisocyanate, a fraction containing >=95 wt.% binuclear methylenediphenyl diisocyanate. Production of a fraction of diisocyanates of the diphenylmethane series containing >=95 wt.% binuclear methylenediphenyl diisocyanate by: (1) reacting aniline and formaldehyde in the presence of an acid catalyst to produce diamines and polyamines of the diphenylmethane series containing binuclear methylenediphenyl diamine; (2) phosgenating the diamines and polyamines of the diphenylmethane series containing binuclear methylenediphenyl diamine to produce a crude diisocyanate and polyisocyanate; and (3) separating from the crude diisocyanate and polyisocyanate, a fraction containing >=95 wt.% binuclear methylenediphenyl diisocyanate comprising greater than 60 wt.% 4,4'-methyl diisocyanate (MDI), 4-35 wt.% 2,4'-MDI, 0.01-10 wt.% 2,2'-MDI relative to the mass of the fraction; and not >20 ppm phenyl isocyanate in a single distillation step. Independent claims are also included for: (1) production of a diphenylmethane diisocyanate mixture comprising blending the separated fraction with a mixture containing an aromatic isocyanate; and (2) production of a polymer comprising reacting the separated fraction and/or the blend of separated fraction with a mixture containing an aromatic isocyanate with a polyol.
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Page/Page column 8
(2008/06/13)
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- METHOD FOR PRODUCING VERY PURE 2,4'-METHYLENE DIPHENYL DIISOCYANATE
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PROBLEM TO BE SOLVED: To produce a mixture of methylene diphenyl diisocyanate (MDI) isomers having a high 2,4'-MDI content, while being decreased in amounts of components, such as 2,2'-MDI, a residual solvent, and phenyl isocyanate, to such an extent as not to disturb production of a polyurethane. SOLUTION: In a method for producing a fraction of diphenylmethane-based diisocyanates, the fraction contains at least binuclear methylene diphenyl diisocyanates in an amount of at least 99 wt% based on a total amount of the fraction.
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Page/Page column 14
(2008/06/13)
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- Distillation process for separating diisocyanatodiphenylmethane isomers
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Distillation of an isomeric mixture of diisocyanatodiphenylmethanes containing at least the 2,2'-, 2,4' and 4,4'-isomers is such that at least in one step a partitioned column is used.
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- A new and efficient catalytic method for synthesizing isocyanates from carbamates
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Operationally simple, recyclable and environmentally friendly montmorillonite efficiently catalyses dealcoholysis of a wide range of mono- and dicarbamates to isocyanates.
- Uriz, Pedro,Serra, Marc,Salagre, Pilar,Castillon, Sergio,Claver, Carmen,Fernandez, Elena
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p. 1673 - 1676
(2007/10/03)
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- Synthesis of isocyanates from carbamate esters employing boron trichloride
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The conversion of carbamate esters to isocyanates and diisocyanates of industrial importance is possible using BCl3 in the presence of Et3N; the reaction is simple in execution and work-up, occurring under mild conditions and affording isocyanates in excellent yields.
- Butler,Alper
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p. 2575 - 2576
(2007/10/03)
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- Fluorine rubber composition
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A fluorine rubber composition comprising a fluorine rubber and a polyfluoroalkyl group-containing block isocyanate compound represented by the following general formula: where Rf is a polyfluoroalkyl group having 4 to 20 carbon atoms; R is a divalent organic group; R1 is a lower alkyl group or phenyl group; R2 is a lower alkyl group; X is NH or O; n is an integer of 1 to 4 and m is 0 or 1, has a good vulcanization bond to metals without any substantial decrease in the rubber stretchability properly owned by the fluorine rubber.
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- Thermochemical Study of Complexation of Carbamates with Isocyanates in Solution
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Complexation of alkyl phenylcarbamates with isocyanates was studied calorimetrically. The compositions, stability constants, and enthalpies of formation of the complexes were determined. The stability of the complexes regularly increases with increasing electron-donor power of substituents in carbamates and electron-acceptor power of isocyanates.
- Gorbatov,Yablokova,Kheidorov
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p. 1838 - 1839
(2007/10/03)
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- Impregnated porous granules and a polyurethane matrix held within the pores thereof and holding a liquid material for controlled release of liquid material and process therefor
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A composition of matter having a clay porous granule and a polyurethane matrix formed from the polymerization of a polyol and a polyisocyanate and held within the pores of the granule and having uniformly distributed throughout the polyurethane matrix a liquid material, for example, a pesticide and a method for loading a porous granule with the polyurethane and the liquid material by: (a) spraying a porous granule with a liquid composition comprising a polyol, a polyisocyanate and a liquid material to be retained in the porous granule, and (b) polymerizing the polyol and the polyisocyanate to form a polyurethane matrix polymer which has the liquid materials uniformly distributed throughout the polyurethane matrix.
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- Method of preparation of cyclic nitrile sulfites
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Cyclic nitrile sulfites are prepared by reacting the corresponding amide with sulfur dioxide in a solvent and in the presence of an oxidizing agent, e.g., lead tetraacetate, and a catalyst, e.g., triethylamine.
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- Ethylenic silicon compounds and thermoplastic elastomers obtained therefrom
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The invention provides organosilicon compounds of the formula: STR1 in which: N IS 1, 2 OR 3; Each R, which may be identical or different, is a monovalent organic group which contains a carbon-carbon double bond and from 2 to 10 carbon atoms; Each R1, which may be identical or different, is a straight or branched alkyl radical optionally substituted by one or more halogen atoms or cyano groups; an aryl radical or an alkylaryl radical optionally substituted by one or more halogen atoms; R2 is a straight or branched divalent alkylene or alkylidene radical possessing up to 4 carbon atoms; X is a divalent radical consisting of, or containing, at least one hetero-atom selected from oxygen, sulphur and nitrogen atoms, the radical being attached to the radical R2 via a said hetero-atom; G is an organic radical of valency (m+ l) possess from 1 to 30 carbon atoms; m is 1, 2 or 3; And each Y, which may be identical or different, is a functional group selected from: --NO2, STR2 --COOM (where M represents a sodium, potassium or lithium atom); --COOR4 ; STR3 --COCl; --OH; --OR4 ; STR4 --SH; --SR4 ; STR5 --CONH2 ; --CSNH2 ; --CN; --CH2 --NH2 ; --CHO; STR6 --NCO; STR7 wherein R3 represents a hydrogen atom or a straight or branched alkyl radical possessing up to 6 carbon atoms and R4 represents an alkyl radical possessing up to 4 carbon atoms, with the proviso that two Y groups can together constitute an imide group STR8 wherein R5 represents a hydrogen atom or a straight or branched alkyl radical possessing up to 4 carbon atoms. These are useful intermediates in the preparation of disilanes and silicon polymers, in particular of polyethylenic silicon compounds which can be polymerized with an α, ω-dihydrogenopolysiloxane to give thermoplastic elastomers.
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- Amide waxes
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Organic amide waxes having at least two amide groups per molecule are prepared by reacting monocarboxylic acids preferably fatty acids with organic di- or poly-isocyanates; the wax products are useful particularly as lubricants.
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