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A kind of isocyanate prepolymer and preparation method thereof

A technology of isocyanate prepolymerization and isocyanate, applied in the field of isocyanate prepolymer and its preparation, can solve the problems of increasing production cost and technical difficulty, large investment in thin film evaporation method, large loss in reaction process, etc., and achieves excellent transparency and low cost. , good stability

Active Publication Date: 2021-06-25
WANHUA CHEM BEIJING +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the film evaporation method can reduce the isocyanate monomer to below 0.5wt%, there are the following problems: (1) to obtain the isocyanate prepolymer of low monomer content, a certain amount of high boiling point entrainer must be used, and the entrainer contains isocyanate It is difficult to recycle the monomer; in addition, there will be a certain amount of entrainer remaining in the product. Due to the high boiling point and difficulty in volatilization of the entrainer, the application performance of the product will be affected in the actual use of isocyanate prepolymer , (2) Thin film evaporation method has large investment, high energy consumption, complex control process, large loss in the reaction process, and the 2,6 body in the evaporated TDI monomer is greatly increased, it is difficult to recycle and directly use it in the preparation of isocyanate prepolymer , which will greatly increase the production cost and technical difficulty, which is unbearable for ordinary enterprises and technologies

Method used

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  • A kind of isocyanate prepolymer and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0066] 1) Add 579.0g TDI80, 1.0g antioxidant 168, 259.4g ethyl acetate to the 1000ml reactor equipped with stirring paddle, thermometer and nitrogen protection, and open the stirring paddle;

[0067] 2) Add 11.4g polyether 1C, 5.7g polyether 2A and 143.0g neopentyl glycol in two batches, raise the temperature to 80°C, react at constant temperature for 2 hours, and lower the temperature to 45°C;

[0068] 3) Detect the percentage of NCO. At this time, the percentage of NCO is 16.28wt%. Add 0.1g of BDMA and 0.1g of DMP-30, react at 45°C for 4h, and detect the content of isocyanate monomer. At this time, the content of isocyanate monomer is 0.43wt%. , add 0.3g of phosphoric acid, continue stirring for 30min and then cool down to 30°C to obtain 1# prepolymer.

Embodiment 2

[0070] 1) Add 571.3gTDI80, 2gBHT, 260.2g ethyl acetate to the 1000ml reactor equipped with stirring paddle, thermometer and nitrogen protection, and open the stirring paddle;

[0071] 2) Add 28.2g of polyether 1A, 10.2g of polyether 2C and 128.0g of methyl propylene glycol in 4 batches, raise the temperature to 65°C, react at constant temperature for 6 hours, and lower the temperature to 52°C;

[0072] 3) Detect the percentage of NCO. At this time, the percentage of NCO is 15.04wt%. Add 0.06g of DMP-30, react at 52°C for 5h, and detect the content of isocyanate monomer. At this time, the content of isocyanate monomer is 0.17wt%. Add 0.06 g benzoyl chloride, continue to stir for 30 minutes and then cool down to 35°C to obtain 2# prepolymer.

Embodiment 3

[0074] 1) Add 435.3gTDI80, 105.7gTDI100, 3g triphenyl phosphite, 251.3g butyl acetate to a 1000ml reactor equipped with stirring paddle, thermometer and nitrogen protection, and start the stirring paddle;

[0075] 2) Add 20.4g of polyether 1B, 8.8g of polyether 2A and 175.3g of dipropylene glycol in 3 batches, raise the temperature to 70°C, react at constant temperature for 4 hours, and lower the temperature to 55°C;

[0076] 3) Detect the percentage content of NCO. At this time, the percentage content of NCO is 14.85wt%. Add 0.1g of triethylenediamine, react at 52°C for 4.5h, and detect the content of isocyanate monomer. At this time, the content of isocyanate monomer is

[0077] 0.40wt%, add 0.12g of benzoyl chloride, continue to stir for 30min and then lower the temperature to 30°C to obtain 3# prepolymer.

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Abstract

The invention discloses an isocyanate prepolymer and a preparation method thereof. The adduct is prepared by reacting a specific combination of polyols and isocyanates, and then a catalyst is added to the adduct to react to generate isocyanurate, while reducing the isocyanate monomer content of the system, and the final isocyanate prepolymerization The solid content is 70-80wt%, preferably 75-77wt%, and the isocyanate monomer content is <0.5wt%. The isocyanate monomer content in the isocyanate prepolymer prepared by the invention is low, and compared with the traditional film evaporator method and solvent extraction method, the process is simple and the cost is low; the isocyanate prepolymer prepared by the invention can be used for primers and matte surfaces Paint with fast drying and good matting properties.

Description

technical field [0001] The invention relates to an isocyanate prepolymer and a preparation method thereof. Background technique [0002] Due to its excellent performance, polyurethane two-component coatings are widely used in surface coating industries such as wood furniture, indoor and outdoor decoration, and mechanical instruments. An important component of two-component polyurethane coatings is the isocyanate prepolymer containing -NCO groups, among which toluene diisocyanate (TDI) and trimethylolpropane (TMP) adducts are currently the most widely used aromatic family of isocyanate prepolymers. The high content of isocyanate monomer can react with the protein in the human body, denature the protein, and cause serious harm to the human body; at the same time, its vapor has a strong tear-jerking effect, which will stimulate the respiratory system after inhalation, causing dry cough, sore throat and other injuries . Therefore, it is very important and necessary to reduce ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G18/76C08G18/66C08G18/48C08G18/12
CPCC08G18/12C08G18/4804C08G18/4833C08G18/6674C08G18/7614
Inventor 文振广朱芸林张啸王凯
Owner WANHUA CHEM BEIJING