Storage-stable liquid pure MDI composition as well as preparation method and application thereof

A technology with stable storage and composition, applied in the field of isocyanates, can solve the problems affecting the quality of polyurethane products, prolong the shelf life, and reduce the effective components, so as to improve the oxidation resistance and yellowing, improve the resistance to low temperature crystallization, and have no impact on product quality. Effect

Active Publication Date: 2021-11-23
WANHUA CHEMICAL (NINGBO) CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002]Diphenylmethane diisocyanate (MDI) is an important raw material for the preparation of polyurethane materials. Due to the high reactivity of the isocyanate group, it has a strong tendency to self-polymerize. It is easy to self-polymerize and form a ring to form a dimer, resulting in a decrease in active ingredients and a decrease in activity. After the dimer is precipitated, the turbidity of the product will increase, which will obviously affect the quality of polyurethane products. However, in many downstream applications, the dimer of isocyanate Content requirements are stringent, so downstream applications may be compromised
[0003] Currently known methods to control the dimer generation of MDI series products mainly include controlling the temperature of the storage process and the method of rectification and crystallization process, but the operation is complicated and there is no obvious method to extend the shelf life for the storage period of liquid pure MDI
Therefore, there is an urgent need for a preparation method of liquid pure MDI with a long storage period, which can improve the storage shelf life of liquid materials, and suppress the phenomenon that the dimer precipitation during the long-term storage of liquid pure MDI leads to turbidity and turbidity of liquid pure MDI.

Method used

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  • Storage-stable liquid pure MDI composition as well as preparation method and application thereof
  • Storage-stable liquid pure MDI composition as well as preparation method and application thereof
  • Storage-stable liquid pure MDI composition as well as preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0069] To prepare a storage-stable liquid pure MDI composition:

[0070] To 500 g of fresh diphenylmethane diisocyanate (2,4-MDI 1 wt%, 4,4-MDI 99 wt%), add 0.4 g BHT and 0.2 g TPP, and add 0.5 g 1-(4,4'-diphenyl Methyl methane isocyanate)-3-(6-hexylidene isocyanate)-1,3-diazacyclo-2,4-butanedione (A-1), stirred at 55°C for 2h to obtain a transparent and clear solid-free 200g of the liquid pure MDI composition were packaged in 250ml transparent glass bottles, and then placed in ovens at 40°C and 45°C respectively, and stored for more than 100 days. The composition remained liquid and clear, and the liquid pure MDI composition The performance test data are shown in Table 1.

[0071] Preparation of isocyanate prepolymers resistant to low temperature crystallization:

[0072] The above 100g liquid pure MDI composition was reacted with 65g CMA254 at 70°C for 3h, then 15g liquefied MDI was added and stirred at 55°C for 0.5h to obtain an isocyanate prepolymer. No crystallization occ...

Embodiment 2

[0074] To prepare a storage-stable liquid pure MDI composition:

[0075] To 500 g of fresh diphenylmethane diisocyanate (2,4-MDI 1 wt%, 4,4-MDI 99 wt%), add 1.0 g BHT and 0.5 g TPP, and add 5 g 1-(4,4'-diphenyl Methane isocyanate)-3-(6-hexylidene isocyanate)-1,3-diazacyclo-2,4-butanedione (A-1), stirred at 55°C for 2h to obtain a transparent and clear solid-free Liquid pure MDI composition, respectively package 200g in 250ml transparent glass bottles, and then place them in ovens at 40°C and 45°C respectively, and store them for more than 180 days. The test data are shown in Table 1.

[0076] Preparation of isocyanate prepolymers resistant to low temperature crystallization:

[0077] React the above 100g liquid pure MDI composition with 65g polyethylene adipate at 80°C for 2h, then add 20g liquefied MDI and stir at 55°C for 0.5h to obtain an isocyanate prepolymer, and place it at 25°C No crystallization occurred within 137h.

Embodiment 3

[0079] To prepare a storage-stable liquid pure MDI composition:

[0080] To 500 g of fresh diphenylmethane diisocyanate (2,4-MDI 1 wt%, 4,4-MDI 99 wt%), add 0.4 g BHT and 0.2 g TPP, and add 5 g 1-(4,4'-diphenyl Methaneisocyanate)-3-(3-isocyanatomethylene-3,5,5-trimethylcyclohexyl)-1,3-diazacyclo-2,4-butanedione (A-2), Stir at 55°C for 2 hours to obtain liquid pure MDI compositions with transparent, clear and solid-free color, respectively package 200g in 250ml transparent glass bottles, and then place them in ovens at 40°C and 45°C respectively, and store them for more than 260 days. Still keep liquid state and clear and transparent, the performance test data of liquid pure MDI composition are as shown in table 1.

[0081] Preparation of isocyanate prepolymers resistant to low temperature crystallization:

[0082] The above 100g liquid pure MDI composition was reacted with 60g polyethylene glycol-1,4-butanediol adipate at 75°C for 2.5h, then 15g liquefied MDI was added and s...

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Abstract

The invention discloses a storage-stable liquid pure MDI composition as well as a preparation method and application of the liquid pure MDI composition. The liquid pure MDI composition is prepared from diphenylmethane diisocyanate, diazacyclobutanedione (formula 1) and/or an isocyanurate six-membered heterocyclic compound (formula 2) and an antioxidant. According to the present invention, the diazacyclobutanedione or isocyanurate six-membered heterocyclic compound having the specific structure is added to the liquid pure MDI, such that the solubility of the liquid pure MDI on the dimer is improved, the storage period of the liquid pure MDI at the temperature of 40-45 DEG C can be prolonged to 100 days or more, and the turbidity increase in the storage period is less than 0.1 NTU. When being used for preparing the isocyanate prepolymer, the compound can also improve the crystallization property of the isocyanate prepolymer and enhance the crystallization resistance of the prepolymer.

Description

technical field [0001] The invention belongs to the technical field of isocyanate, relates to a liquid pure MDI composition, in particular to a storage-stable liquid pure MDI composition and its preparation method and application. Background technique [0002] Diphenylmethane diisocyanate (MDI) is an important raw material for the preparation of polyurethane materials. Due to the high reactivity of the isocyanate group, it has a strong tendency to self-polymerize. Decreased activity, decreased product turbidity after dimer precipitation will obviously affect the quality of polyurethane products, and many fields in downstream applications have strict requirements on the dimer content of isocyanate, so downstream applications may be affected. Diphenylmethane diisocyanate (MDI) has 3 isomers, namely 2,2'-MDI, 2,4'-MDI and 4,4'-MDI, more than 98% of 4,4'-MDI is MDI -100, that is, pure MDI; MDI-50 is composed of 2,4'-MDI and 4,4'-MDI each accounting for 50% by mass. There are d...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G18/76C08G18/79C08G18/42C08G18/10C08G18/12
CPCC08G18/725C08G18/7671C08G18/791C08G18/798C08G18/42C08G18/10C08G18/12
Inventor 朱梦雅陈盟王伟包金鹏肖应鹏王文博张宏科
Owner WANHUA CHEMICAL (NINGBO) CO LTD
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