Method for combined production of TDI and stabilized tar and utilization method of stabilized tar

A stabilizing and tar technology, applied in chemical instruments and methods, tar refining by chemical methods, and preparation of organic compounds, etc., can solve the problems of complex treatment process, large molecular weight, poor stability, etc. high rate effect

Active Publication Date: 2021-11-30
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The traditional technology treats the liquid tar produced in the TDI synthesis process through a disc dryer to recover TDI and directly incinerates the remaining tar residue, but the accompanying disadvantages are: (1) need to add expensive disc dryer equipment and high-temperature incinerator ( 1000°C or higher); (2) The tar is partially cracked during the drying process, producing by-products, which affects the quality of TDI products; (3) The high-temperature combustion process produces a large amount of carbon emissions, and at the same time generates secondary pollutants, including nitrogen oxides (NO x ), sulfur oxides (SO x ), dioxins, etc., and other equipment is required to remove them
Among them, it is a well-known technology to hydrolyze TDI tar residue foam to prepare TDA by add

Method used

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  • Method for combined production of TDI and stabilized tar and utilization method of stabilized tar

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] [Preparation Example 1] Preparation of Cyclopolyamine A

[0047] Aniline, formaldehyde, and hydrochloric acid were mixed at a molar ratio of 2:1:1, stirred at 50°C for 0.8h, and then stirred at 120°C for 2.2h. After the reaction was completed, 32% NaOH solution was added for neutralization, so that the remaining NaOH concentration in the solution after neutralization was 2%. Stand to separate and separate, take the upper oil phase, remove aniline and water by steam stripping, and obtain the cyclic polyamine product, which is recorded as cyclic polyamine A.

[0048] Cyclic polyamine A was analyzed by liquid chromatography, and the number of single-molecule aromatic rings was 2.

Embodiment 2

[0049] [Preparation Example 2] Preparation of Cyclopolyamine B

[0050] Aniline, formaldehyde, and 50% sulfuric acid were mixed at a molar ratio of 6:5:1, stirred at 40° C. for 1 h, and then stirred at 180° C. for 0.6 h. After the reaction was completed, 32% NaOH solution was added for neutralization, so that the remaining NaOH concentration in the solution after neutralization was 4%. Stand to separate and separate, take the upper oil phase, remove aniline and water by steam stripping, and obtain the cyclic polyamine product, which is recorded as cyclic polyamine B.

[0051] Cyclic polyamine A was analyzed by liquid chromatography, and the number of aromatic rings in the single molecule was 6.

Embodiment 3

[0052] [Preparation Example 3] Preparation of Cyclopolyamine C

[0053] Aniline, formaldehyde, and 50% sulfuric acid were mixed at a molar ratio of 4:3:0.5, stirred at 75°C for 0.5h, and then stirred at 160°C for 0.8h. After the reaction was completed, 32% NaOH solution was added for neutralization, so that the remaining NaOH concentration in the solution after neutralization was 1%. Stand to separate and separate, take the upper oil phase, remove aniline and water by steam stripping, and obtain the cyclic polyamine product, which is recorded as cyclic polyamine C.

[0054] Cyclic polyamine A was analyzed by liquid chromatography, and the number of aromatic rings in the single molecule was 4.

[0055] 【Example 1】

[0056] Mix toluenediamine, o-dichlorobenzene (ODCB), and cyclopolyamine A at a mass ratio of 1:2:0.2, and the mixing temperature is 100°C. The above mixed material was jet-mixed with a phosgene solution with a mass concentration of 50%, wherein the mass of phosge...

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Abstract

The invention discloses a method for combined production of TDI and stabilized tar and a utilization method of the stabilized tar. The method for combined production of TDI and stabilized tar comprises the following steps: 1) carrying out phosgenation reaction on amine in the presence of an inert solvent to generate crude TDI, wherein the amine is a mixture of toluenediamine and cyclic polyamine; and 2) removing phosgene and an inert solvent from the crude TDI, and further performing rectification separation to respectively obtain the product TDI and the stabilized tar. According to the invention, the cyclic polyamine and toluenediamine are mixed and fed to produce TDI and co-produce the stabilized tar at the same time, so that the tar can be used as a raw material of an adhesive for resource reutilization favourably, the process is simple and safe, and the waste utilization rate is high.

Description

technical field [0001] The invention relates to a co-production method, in particular to a method for TDI co-production of stabilized tar and a utilization method of the stabilized tar. Background technique [0002] TDI (toluene diisocyanate) is an important raw material for polyurethane production, mainly used for raw materials and intermediates of polyurethane soft foam, hard foam, adhesives, coatings, sealants and a series of elastomers. At the end of the TDI synthesis process, TDI is usually separated from the product mixture by rectification. The high-boiling distillation residue discharged after the bottom fraction of the rectification tower is dried is commonly known as liquid tar. Liquid tar contains 30-70% TDI, and other substances are mainly CDI and UTI. The formation reaction is as follows: [0003] MTDA+TDI→urea [0004] MTDA+carbamoyl chloride→urea [0005] TDI+urea→urea [0006] Urea / urea+phosgene→CDI [0007] CDI+TDI→UTI [0008] The traditional technolo...

Claims

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Application Information

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IPC IPC(8): C07C263/10C07C263/20C07C265/14C10C1/20C09J187/00C08G81/00C07D245/04C07D487/22C07D487/14
CPCC07C263/10C07C263/20C10C1/20C09J187/005C08G81/00C07D245/04C07D487/22C07D487/14C07C265/14
Inventor 胡淼张钊滟魏立彬邓如雷吴雪峰张宏科
Owner WANHUA CHEM GRP CO LTD
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