Process for preparing polyisocyanate by solid phosgene

A polyisocyanate and solid phosgene technology, which is applied in the preparation of isocyanate derivatives, chemical instruments and methods, and the preparation of organic compounds, etc., can solve the problems of cumbersome process, complicated post-treatment and purification process, and insufficient color and mechanical properties of isocyanate polyurethane. Meet the use requirements and other issues

Inactive Publication Date: 2006-09-06
北京金源化学集团有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These methods are to control the condensation reaction process of amine and solid phosgene by adding materials at low temperature, and then heating for elimination reaction. The reaction needs to be cooled first and then heated, and the process is more cumbersome.
Moreover, in the patent CN1394851, the phosgenation reaction is carried out under pressurized conditions, and the requirements for the reaction equipment are relatively high. At the same time, the HCl formed in the reaction cannot be discharged, so that the HCl content in the final product increases.
In addition, the 1,5-diaminonaphthalene solution is added to the solid phosgene solution at a faster rate, which may cause local overheating, increase side reactions, and may form a large amount of tarry products
The increase in the number of by-products in the final product makes the post-treatment purification process of the reaction more complicated and greatly reduces the purity of the product
All of these will cause the obtained isocyanate to fail to meet the use requirements in terms of color and mechanical properties when preparing polyurethane.
[0007] The above methods for preparing isocyanates using solid phosgene are limited to primary amines and diamines, and the phosgenation reactions of polyamines above triamines and salts of amines and acids are not discussed.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Lysine Triisocyanate (LTI):

[0019] Add 449.6g (4.31mol) 35% HCl solution in 1L four-necked flask and dropwise add 167.2g (2.74mol) ethanolamine in 30 minutes, add 250.0g (1.37mol) lysine hydrochloride after dropwise addition, and The reaction was stirred at 45°C for 10 minutes. The temperature was raised to 110°C, the pressure was reduced to 4KPa, and the water in the reaction system was evaporated. After returning to normal pressure, HCl gas was passed through to react for 3 hours, and then the water was evaporated under reduced pressure. This process is repeated several times, and the reaction is stopped after lysine hydrochloride is consumed, and o-dichlorobenzene (ODCB) and methanol are added to crystallize, and the crystal is washed several times with ODCB to obtain lysine aminoethyl ester trihydrochloride (LAET) .

[0020] The 2500ml reactor is equipped with mechanical stirring and two sets of dripping devices. Add 100ml o-dichlorobenzene (ODCB) in the react...

Embodiment 2

[0022] Lysine Triisocyanate (LTI):

[0023] Except that bis-(trichloromethyl)carbonate is changed into 445.5g (1.5mol), other reaction conditions are the same as embodiment 1, obtain LTI content 68.6% (HPLC) in the product, NCO content 40.3wt% (theoretical value 47.2wt%) %), HCl content 0.70wt%, ODCB content 0.81wt%.

Embodiment 3

[0025] Lysine Triisocyanate (LTI):

[0026] Except that bis-(trichloromethyl) carbonate is changed to 891g (3mol), other reaction conditions are the same as in Example 1, and LTI content 86.3% (HPLC) is obtained in the product, NCO content 43.6wt% (theoretical value 47.2wt%) , HCl content 0.35wt%, ODCB content 0.31wt%.

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PUM

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Abstract

The invention relates to a method for preparation of 1, 2-dialkoxy-3-fluorobenzene by an intermediate of 2-fluorin-6-halogenated phenol. The said method consists of selecting 2-fluorophenol as its stock, and obtaining the intermediate of 2-fluorin-6-halogenated phenol; afterwards, performing multiple steps such as etherifing the said intermediate and etherifing again by introducing the hydroxyl group, alternatively, hydroxylating and etherifing the said intermediate; finally, obtaining the said 1, 2-dialkoxy-3-fluorobenzene. The method is of low cost, high yield rate, so it is suitable for the industrial production.

Description

technical field [0001] The invention relates to a method for preparing polyisocyanate by using solid phosgene and polyamine or its salt. Background technique [0002] Isocyanates are commonly used in the preparation of polyurethane resins, coatings and adhesives. As we all know, polyurethane has a wide range of applications in optical materials, automotive and construction materials, sealing materials, and daily necessities due to its good mechanical properties. In addition, polyisocyanates and polyurethane resins prepared from amino acids, such as lysine, can be used in biomedicine due to their good biocompatibility. [0003] Current methods for preparing isocyanates generally utilize the reaction of phosgene with amines. In patents US5,136,086, US4,419,295, JP2002-003462, JP06-234722, CN1125718A, CN1197793A, CN1516688A and EP424836, phosgene is used to phosgenate amines to prepare isocyanates. However, there are many problems in this method due to the use of phosgene. F...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C265/14C07C263/10
Inventor 邱明建张炜陈朝晖张春山张雅丽
Owner 北京金源化学集团有限公司
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