Curing agent methylene diphenyl diisocyanate tripolymer and method for preparing same

A technology of diphenylmethane and diisocyanate, which is applied in the field of diphenylmethane diisocyanate trimer curing agent and its preparation, can solve the problems of harming the health of production workers, trimer application, and low production efficiency. Fast curing speed at room temperature, good storage stability and high production efficiency

Active Publication Date: 2012-11-07
J&H XIANGYANG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Diphenylmethane diisocyanate and its homologues (MDI for English abbreviation) are raw materials widely used in the polyurethane industry. Among them, 4,4'-MDI, which accounts for the main output, has excellent strength and fast curing at room temperature, but its symmetry and regularity , The rigid structure prevents the existing manufacturing technology from making trimers into coatings and adhesives. MDI is mainly used as polyurethane foaming and potting materials
The biggest disadvantage of TDI trimer is that there are many residual free monomers, which are difficult to remove, require technically difficult and expensive thin film evaporation, solvent extraction and other processes, low production efficiency, and large energy consumption. This removal process was not performed
Free TDI will pollute the environment and damage the health of production workers, which is not allowed by the national environmental protection law

Method used

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  • Curing agent methylene diphenyl diisocyanate tripolymer and method for preparing same
  • Curing agent methylene diphenyl diisocyanate tripolymer and method for preparing same
  • Curing agent methylene diphenyl diisocyanate tripolymer and method for preparing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] a. Add 200 grams of MDI-50 (that is, a mixture of 50% by weight of 4,2'-MDI and 50% by weight of 4,4'-MDI) liquid and 60 grams of butyl acetate into the reaction kettle, and heat up to 60°C Dissolve it and stir evenly, cool down to 50°C, add 52 grams of alkyd resin polyol, react at 60-70°C for 2 hours, and react at 80-90°C for 2 hours; The mixed solution composed of butylphosphine and 20 grams of ethyl acetate was reacted at 35-40°C for 1 hour, then heated to 50-55°C for reaction, and the NCO percentage content was detected by sampling every 1 hour. When the NCO content dropped to 11.0% (when the degree of trimerization of MDI reaches 95%, the theoretical NCO% of the system is 11.1%), add a mixed solution of 0.03 gram of benzoyl chloride and 4 gram of ethyl acetate, heat up to 70 ℃ for 0.5 hour, and then Cool down to 50° C.; c, discharge to obtain 336 grams of light yellow transparent MDI trimer curing agent with a solid content of 75%. The NCO percentage of the curing...

Embodiment 2

[0053] a. Add 200 grams of MDI-50 liquid and 170 grams of butyl acetate into the reaction kettle, heat up to 40°C, add 18.3 grams of dehydrated ethyl hexanediol, react at 40-50°C for 1.5 hours, and react at 60-75°C 2 hours; b. Cool down to 45°C, add dropwise a mixture of 0.3g of lithium acetate and 30g of ethyl acetate, react at 45-55°C for 1 hour, then raise the temperature to 60-70°C for reaction, and take samples every 1 hour Detect the NCO percentage content, when the NCO content drops to 8.4% (set when the degree of MDI trimerization reaches 98%, the theoretical NCO% with a solid content of 52% is 8.2%), add 0.04 gram of phosphoric acid and 19 gram of ethyl acetate The mixed solution of ester is heated up to 80 DEG C and is incubated for 1 hour, and then cooled to 50 DEG C; c, discharging, to obtain 437 grams of MDI trimer curing agent with a solid content of 50%. The NCO percentage of the curing agent was detected to be 7.6%. (219 grams of solvent, 218.6 grams of reacta...

Embodiment 3

[0055] a. Add 100 grams of molten MDI-100 (i.e. pure 4,4'-MDI), 100 grams of MDI-50 liquid and 100 grams of butyl acetate into the No. 1 reaction kettle, heat up to 60°C, dissolve and stir evenly, Cool down to 40°C, add 5 grams of dehydrated neopentyl glycol and 6 grams of butyl ethyl propylene glycol, react at 50-60°C for 1 hour, and react at 70-80°C for 1 hour to obtain a modified MDI solution; b. In the No. 2 reaction kettle, add a mixed solution composed of 100 grams of ethyl acetate and 0.1 grams of tri-n-butylphosphine, raise the temperature to 40 ° C, and then add the MDI modified product solution prepared in the No. In the kettle, control the temperature during the feeding process to be uniform and rise slowly. After adding the material in 3 hours, react at 40-45°C for 1 hour, then raise the temperature to 50-55°C for reaction, and take samples every 1 hour to detect the percentage of NCO. When NCO When content drops to 8.4%, add the mixed solution that 0.04 gram benzo...

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Abstract

The invention discloses a curing agent, namely a methylene diphenyl diisocyanate (MDI) tripolymer and a method for preparing the same. The method comprises the following steps of: adding the MDI and an organic solvent into a reaction kettle, raising the temperature, dissolving the MDI, stirring uniformly, adding dehydrated polyol, and reacting for 1 to 6 hours at the temperature of between 40 and90 DEG C to obtain modified MDI; reducing the temperature to 40 DEG C, dripping mixed solution of a trimerization catalyst and an organic solvent, reacting at the temperature of between 30 and 80 DEGC, and adding a polymerization inhibitor when the percentage of isocyanate group (NCO) reaches a preset value; and reducing the temperature to obtain the MDI tripolymer curing agent. The invention provides the method for preparing the tripolymer curing agent by using the MDI. The process is simple, the requirements of equipment are low, the content of the tripolymer is high, and the curing agent is well soluble in resins and can substitute a tolylene diisocyanate (TDI) tripolymer with similar performance. The curing agent is mainly used for being matched with two-component polyurethane coatings and main agents of adhesives, and can also be used for other fields.

Description

technical field [0001] The invention relates to a polyurethane coating, an adhesive curing agent and a preparation method thereof, in particular to a diphenylmethane diisocyanate trimer curing agent and a preparation method thereof. Background technique [0002] Diphenylmethane diisocyanate and its homologues (MDI for English abbreviation) are raw materials widely used in the polyurethane industry. Among them, 4,4'-MDI, which accounts for the main output, has excellent strength and fast curing at room temperature, but its symmetry and regularity 1. The rigid structure prevents the existing manufacturing technology from being able to make trimers into coatings and adhesives. MDI is mainly used as polyurethane foaming and potting materials. [0003] After reviewing relevant patent documents, there is currently no patent report on the manufacture of 4,4'-MDI trimer products in the world. Only some MDI isomers are used in the published instructions of invention patent applicatio...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G18/76C08G18/09C09D175/04C09J175/04
Inventor 周建明何绍群
Owner J&H XIANGYANG CHEM
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