2536-05-2

Basic information

• Product Name: 2,2'-methylenediphenyl diisocyanate
• Synonyms: 2,2'-methylenediphenyl diisocyanate;Benzene, 1,1-methylenebis2-isocyanato-;22MDI;1,1'-Methylenebis(2-isocyanatobenzene);Bisphenol F diisocyanate;Diphenylmethane-2,2'-diisocyanate;1,1'-Methylenebis[2-isocyanatobenzene], 2,2'-methylenediphenyl diisocyanate, diphenylmethane-2,2'-diisocyanate;3-amino-6-chloropyridine-2-thiol
• CAS NO: 2536-05-2
• Molecular Formula: C₁₅H₁₀N₂O₂
• Molecular Weight: 334.2857
• EINECS: 219-799-4
• Mol File: 2536-05-2.mol

Chemical Properties

• Boiling Point: 379.3°Cat760mmHg
• Flash Point: 156.5°C
• Appearance: /
• Density: 1.13g/cm³
• Vapor Pressure: 5.92E-06mmHg at 25°C
• Refractive Index: 1.587
• CAS DataBase Reference: 2,2'-methylenediphenyl diisocyanate(CAS DataBase Reference)
• NIST Chemistry Reference: 2,2'-methylenediphenyl diisocyanate(2536-05-2)
• EPA Substance Registry System: 2,2'-methylenediphenyl diisocyanate(2536-05-2)

Safety Data

• Hazardous Substances Data: 2536-05-2(Hazardous Substances Data)

Usage

Uses

Used in Polyurethane Industry:
2,2'-Methylenediphenyl diisocyanate is used as a key ingredient in the production of polyurethane. It serves as a starting material for the synthesis of polyurethane polymers, which are versatile materials with a wide range of applications due to their unique properties, such as flexibility, durability, and resistance to various environmental factors.
Polyurethane is commonly used in the manufacturing of various products, including foams, coatings, adhesives, sealants, and elastomers. The use of 2,2'-methylenediphenyl diisocyanate in polyurethane production allows for the creation of materials with specific characteristics tailored to the needs of different industries and applications.

InChI:InChI=1/C15H10N2O2/c18-10-16-14-7-3-1-5-12(14)9-13-6-2-4-8-15(13)17-11-19/h1-8H,9H2

Upstream product

• 75-44-5 phosgene 
• 6582-52-1 2,2'-methylenedianiline 
• 101-77-9 4,4'-diamino diphenyl methane 
• 1208-52-2 2,4'-diaminodiphenylmethane 
• 50-00-0 formaldehyd 

Downstream Products

• 47636-24-8 dibutyl diphenyl methane-4,4’-dicarbamate 

Relevant articles and documents

PROCESS FOR PRODUCING DIAMINES AND POLYAMINES OF THE DIPHENYLMETHANE SERIES

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.

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.

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.

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.

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).

METHOD FOR PRODUCING VERY PURE 2,4'-METHYLENE DIPHENYL DIISOCYANATE

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.

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

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.