Process for preparing TDI isocyanurate

Patent metadata

Field	Value
Publication number	US-9593089-B2
Application number	US-201414652242-A
Country	US
Kind code	B2
Filing date	Feb 11, 2014
Priority date	Mar 19, 2013
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

The present invention relates to a method for preparing TDI (toluene diisocyanate) isocyanurate by using TDI, monohydric alcohol, solvent, antioxidant, catalyst and termination agent as the raw materials. The properties of the isocyanurate are improved by the process comprising the modification by monohydric alcohol and addition of the catalyst and solvent in several stages at an appropriate temperature. By adding the catalyst and solvent in batches at the condition of controlling both NCO % and the viscosity in the preparation process, and adjusting the solid content at each step, the resulting TDI isocyanurate has low content of free TDI, high xylene tolerance, small product color number, and high performance stability, which makes the product obtained by the isocyanurate have good application properties such as the drying, polishing and extinction properties of coating film, and such isocyanurate has good compatibility with other components.

First claim

What is claimed is:

1. A process for preparing TDI isocyanurate, characterized in that said TDI isocyanurate is prepared by addition reaction using TDI, monohydric alcohol, solvent, antioxidant, catalyst and termination agent as the raw materials wherein the catalyst and the solvent are added in several stages, said process comprises:
1) The total amount of TDI, the total amount of the antioxidant and the total amount of the monohydric alcohol are placed into a reactor, and thereto a first portion of solvent is added, such that the solid content of the raw materials in the reactor is 59˜100%, and the reactor is heated to the temperature of 30˜60° C. and the reaction is conducted for 20˜30 min;
2) 60˜80% of the total amount of the catalyst is added into the reactor, and the reaction is further conducted at the controlled temperature of 40˜70° C.;
3) When NCO % is 25˜30 wt % and the viscosity measured at 25° C. is ≧200 mPa.s, 10˜20% of the total amount of the catalyst and a second portion of solvent are added into the reactor, such that the solid content of the reaction liquid in the reactor is 59˜90%, and the reaction temperature is controlled at 40˜70° C.;
4) When NCO % is 13˜17 wt % and the viscosity measured at 25° C. is ≧5000 mPa.s, the remaining portion of the catalyst and a third portion of solvent are added into the reactor, such that the solid content of the reaction liquid in the reactor is 59˜75%, and the reaction temperature is controlled at 40˜70° C.;
5) When NCO % is 9˜12 wt % and the viscosity measured at 25° C. is ≧5000 mPa.s, a fourth portion of solvent are added into the reactor, such that the solid content of the reaction liquid in the reactor is 38˜59%, the reaction temperature is controlled at 40˜70° C., and the reaction is continued; and when NCO % is 7.0˜8.8 wt %, the termination agent is added, the temperature is lowered to 25˜30° C. after stirring for 20˜30 min, and then the preparation is completed and the product is discharged.

2. The process as claimed in claim 1 , characterized in that said process comprises:
1) The total amount of TDI, the total amount of the antioxidant and the total amount of the monohydric alcohol are placed into a reactor, and thereto a first portion of solvent is added, such that the solid content of the raw materials in the reactor is 80˜90%, and the reactor is heated to the temperature of 50˜55° C. and the reaction is conducted for 20˜30 min;
2) 60˜80% of the total amount of the catalyst is added into the reactor, and the reaction is further conducted at the controlled temperature of 55˜60° C.;
3) When NCO % is 25˜30 wt % and the viscosity measured at 25° C. is ≧200 mPa.s, 10˜20% of the total amount of the catalyst and a second portion of solvent are added into the reactor, such that the solid content of the reaction liquid in the reactor is 70˜75%, and the reaction temperature is controlled at 50˜65° C.;
4) When NCO % is 13˜17 wt % and the viscosity measured at 25° C. is ≧5000 mPa.s, the remaining portion of the catalyst and a third portion of solvent are added into the reactor, such that the solid content of the reaction liquid in the reactor is 60˜65%, and the reaction temperature is controlled at 50˜65° C.;
5) When NCO % is 9˜12 wt % and the viscosity measured at 25° C. is ≧5000 mPa.s, a fourth portion of solvent are added into the reactor, such that the solid content of the reaction liquid in the reactor is 48˜52%, the reaction temperature is controlled at 50˜65° C., and the reaction is continued; and when NCO % is 7.0˜8.8 wt %, the termination agent is added, the temperature is lowered to 25˜30° C. after stirring for 20˜30 min, and then the preparation is completed and the product is discharged.

3. The process as claimed in claim 1 , characterized in that said TDI is chosen from the group consisting of TDI-65 having the molar ratio of toluene-2,4-diisocyanate and toluene-2,6-diisocyanate of 65:35, TDI-80 having the molar ratio of toluene-2,4-diisocyanate and toluene-2,6-diisocyanate of 80:20, TDI-100 consisting of toluene-2,4-diisocyanate or any combination thereof.

4. The process as claimed in claim 1 , characterized in that said antioxidant is chosen from the group consisting of pentaerythritol tetra[β-(3,5-ditertbutyl-4-hydroxyphenyl)-propionate], ditertbutyl-4-methylphenol, triphenyl phosphite, trioctyl phosphite, tridecyl phosphite, and tri(2,4-ditertbutyl-phenyl) phosphite or any combination thereof.

5. The process as claimed in claim 1 , characterized in that said solvent is one or two chosen from the group consisting of ethyl acetate and butyl acetate, and the amount of said solvent is 41˜62% based on the total weight of the raw materials.

6. The process as claimed in claim 1 , characterized in that said catalyst is chosen from the group consisting of tri(n-butyl) phosphine, triethylene diamine, 2,4,6-tri(dimethylaminomethyl) phenol, N,N-dimethyl benzyl amine and any combination thereof, and the amount of said catalyst is 0.03˜0.3% based on the total weight of the raw materials.

7. The process as claimed in claim 1 , characterized in that said termination agent is one or two chosen from the group consisting of phosphoric acid and benzoyl chloride, and the termination agent is 0.01˜0.2% based on the total weight of the raw materials.

8. The process as claimed in claim 1 , characterized in that said monohydric alcohol is chosen from the group consisting of diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, butyl alcohol, amyl alcohol, octyl alcohol, or any combination thereof.

9. The process as claimed in claim 1 , characterized in that: based on the total weight of the all the starting materials, the amount of the starting materials is shown as:

Toluene diisocyanate (TDI)
36~55%

Monohydric alcohol
0.3~12%

Solvent
41~62%

Antioxidant
0.1~1%

Catalyst
0.03~0.3%

Termination agent
0.01~0.2%.

10. The process as claimed in claim 3 , characterized in that said TDI is one or both chosen from TDI-80 and TDI-100, and the amount of TDI is 36˜55% based on the total weight of the starting materials.

11. The process as claimed in claim 4 , characterized in that said antioxidant is chosen from pentaerythritol tetra[β-(3,5-ditertbutyl-4-hydroxyphenyl)-propionate]), ditertbutyl-4-methylphenol, triphenyl phosphite, tri(2,4-ditertbutyl-phenyl) phosphite or any combination thereof, and the amount of said antioxidant is 0.1˜1% based on the total weight of the starting materials.

12. The process as claimed in claim 8 , characterized in that said monohydric alcohol is chosen from the group consisting of diethylene glycol monobutyl ether, ethylene glycol mon

Assignees

• Wanhua Chemical (Beijing) Co Ltd
• Wanhua Chemical Group Co Ltd
• Wanhua Chemical (Ningbo) Co Ltd

Inventors

• Zhang Xiao
• Zhu Yulin
• Wen Zhenguang
• Wang Kai

Classifications

• C07D251/34 Primary

  Cyanuric or isocyanuric esters · CPC title

• C08G18/092

  oligomerisation to isocyanurate groups · CPC title

• C08G18/022

  the polymeric products containing isocyanurate groups · CPC title