A kind of preparation method of polyurethane curing agent

A technology of polyurethane curing agent and polyurethane prepolymer, which is applied in the preparation of toluene diisocyanate polyurethane curing agent and the field of polyurethane curing agent. The effect of increasing consumption and feeding speed

Active Publication Date: 2017-12-26
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to provide a kind of preparation method of polyurethane curing agent, in this method, the inorganic salt as hydrogen bond complexing agent effectively solves the difficult problem of isocyanate monomer caused by the increase of viscosity of polyurethane prepolymer in the thin film evaporation separation process. There is a problem of complete evaporation. At the same time, the inorganic salt is cooled and precipitated after the solvent is diluted to obtain the product. It can be separated and recovered by filtration. The whole process does not produce three wastes, which is environmentally friendly and energy-saving. Environmentally friendly, non-toxic and high-quality products are obtained.

Method used

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  • A kind of preparation method of polyurethane curing agent
  • A kind of preparation method of polyurethane curing agent
  • A kind of preparation method of polyurethane curing agent

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] 1kg of diethylene glycol and 2.2kg of trimethylolpropane are used to form a mixed alcohol and heated at 70°C for stand-by; 2,6-TDI composition) into the reaction kettle, heated and stirred at 50°C, then added the mixed alcohol dropwise into the reaction kettle for 1 hour; after the dropwise addition, continued to stir and react at 50°C for 1 hour , the obtained polyurethane prepolymer reaction solution enters the polyurethane prepolymer tank at 60°C and keeps warm for use;

[0047] To the obtained polyurethane prepolymer reaction solution containing free toluene diisocyanate monomer, the temperature was raised to 100° C., 2 g of calcium chloride dehydrated at high temperature was added and stirred for 15 minutes, and then separated by a thin-film evaporator with a vacuum of 0.1 mbar. The separated prepolymer enters the dilution kettle and dilutes with ethyl acetate to obtain a product with a solid content of 75wt%. After the product is cooled to room temperature and the...

Embodiment 2

[0049] 700g of ethylene glycol and 1.5kg of trimethylolethane are used to form a mixed alcohol and heated and kept warm at 70°C for use; 2,6-TDI composition) into the reaction kettle, heated and stirred at 55°C, then added the mixed alcohol dropwise into the reaction kettle for 2 hours; after the dropwise addition, continued to stir and react at 55°C for 2 hours Finally, the resulting polyurethane prepolymer reaction solution enters the polyurethane prepolymer tank at 70°C and is kept warm for use;

[0050] The resulting polyurethane prepolymer reaction solution containing excess toluene diisocyanate monomer was heated up to 100°C, 10 g of sodium chloride dehydrated at high temperature was added and stirred for 15 minutes, and then separated by a thin film evaporator with a vacuum of 2 mbar. The separated prepolymer enters the diluting tank and dilutes with ethyl acetate to obtain a product with a solid content of 50wt%. After the product is cooled to room temperature and the ...

Embodiment 3

[0052] 1kg of 1,4-butanediol and 1kg of glycerol are used to form a mixed alcohol and heated at 70°C for use; under nitrogen protection, 20kg of toluene diisocyanate 70 / 30 (70wt% of 2,4-TDI and 30wt% 2,6-TDI composition) into the reaction kettle, heated and stirred at 60°C, then added the mixed alcohol dropwise into the reaction kettle for 2 hours; after the dropwise addition, continued to stir and react at 60°C for 1 hour Finally, the resulting polyurethane prepolymer reaction solution enters the polyurethane prepolymer tank at 70°C and is kept warm for use;

[0053] To the obtained polyurethane prepolymer reaction solution containing excess toluene diisocyanate monomer, the temperature was raised to 90° C., 200 g of sodium sulfate dehydrated at high temperature was added and stirred for 20 minutes, and then separated by a thin-film evaporator with a vacuum of 1 mbar. The separated prepolymer enters the diluting tank and dilutes with butyl acetate to obtain a product with a s...

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Abstract

The invention relates to a preparation method of a polyurethane curing agent. In the first step, under the protection of nitrogen, the mixed alcohol is added to a reaction kettle equipped with toluene diisocyanate (TDI) for reaction, and after the reaction is completed, it is kept warm for use; the second step , add hydrogen bond complexing agent based on toluene diisocyanate 0.01wt%-1wt% to the prepolymer reaction solution, stir and dissolve, then use a thin film evaporator to separate, the separated prepolymer is diluted to obtain a polyurethane curing agent, and cool After stirring, the hydrogen bond complexing agent is precipitated, and after filtration, a polyurethane curing agent product with a solid content of 50-80wt% and a free TDI content of 0-0.1wt% is obtained. The advantages of the present invention are that the content of free isocyanate monomers in the product is extremely low, and it is environmentally friendly and non-toxic; it reduces energy consumption and improves separation efficiency, effectively recovers TDI monomers and inorganic salts, improves their utilization rate, realizes clean production and reduces production cost.

Description

technical field [0001] The invention relates to a preparation method of a polyurethane curing agent, in particular to a preparation method of a toluene diisocyanate polyurethane curing agent with an ultra-low free content, and belongs to the field of coating curing agents. Background technique [0002] The coating film of polyurethane coating has excellent properties such as high hardness, good toughness, strong chemical resistance, and fast drying. It is one of the coatings with excellent performance and large dosage in solvent-based coatings, and occupies a dominant position in furniture wood coatings. Polyurethane coatings are composed of two components. One component is based on hydroxyl substances such as alkyd resin, polyester resin and acrylic resin, and the other key component is formed by preliminary polymerization of isocyanate monomer and alcohol, or by Polyurethane prepolymer formed by self-polymerization of isocyanate monomer. [0003] Since the polyurethane cu...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C08G18/76C08G18/32C08G18/12C09D175/04
CPCC08G18/8035C09D175/04
Inventor王玉启尚永华何勇刘伟王暖程华卫琦黎源
OwnerWANHUA CHEM GRP CO LTD