Preparation method of polyurethane trimer curing agent of low free isocyanate monomer

A polyurethane trimer, isocyanate technology, applied in polyurea/polyurethane coatings, organic chemistry, coatings, etc., can solve the problems of incompatible resins, low xylene dilution rate, limited application scope, etc. Stable gloss, excellent resistance to yellowing, and increased steric hindrance

Active Publication Date: 2012-10-10
SOUTH CHINA UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In addition, due to the strong polarity of the six-membered isocyanate ring of the existing trimer curing agent, the polyurethane trimer is selective when matching with the resin, and cannot be well compatible with most resins, so its application range has been restricted to a certain extent. limit
Poor compatibility, low dilution rate of xylene, when mixing paint, need to use a lot of real solvent, high cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] The preparation method of the polyurethane trimer curing agent of low free isocyanate monomer comprises the steps:

[0030](1) Under nitrogen protection, first put TDI 80 (2,4-TDI mass fraction accounts for 80%, 2,6-TDI mass fraction accounts for 20%) 108g and n-butyl acetate 95g into the reaction vessel and stir evenly, The temperature was maintained at 70°C, and then 4.8g of 1,4-butanediamine was added dropwise into the reaction vessel under stirring conditions, and the dropwise addition time was 1 hour; after the dropwise addition was completed, 0.3g of tri-n-butyl The phosphine was stirred and reacted at 85° C. for 4 hours. When the NCO group content was reduced to 22.6%, 0.5 g of benzoyl chloride was added immediately, kept for 1 hour, cooled and discharged immediately to obtain a polyurethane trimer curing agent.

[0031] (2) Put the polyurethane curing agent obtained in step (1) at a feed rate of 8g / min, and enter the internal cooling molecular still through the ...

Embodiment 2

[0033] The preparation method of the polyurethane trimer curing agent of low free isocyanate monomer comprises the steps:

[0034] (1) Under the protection of nitrogen, first put TDI 80 115g and ethyl acetate 100g into the reaction vessel and stir evenly. The temperature was maintained at 50°C, and then 13.5g of trimethylhexamethylenediamine was added dropwise to the reaction vessel under stirring condition. In the above-mentioned reaction vessel, the dropwise addition time was 1.5 hours; after the dropwise addition was completed, 0.5g of tertiary amine was added at one time, and the stirring reaction was continued at 70°C for 5 hours. When the NCO group content was reduced to 20.3%, 0.1g of phosphoric acid was added immediately, Insulated for 2 hours, immediately cooled and discharged to obtain a polyurethane trimer curing agent.

[0035] (2) Put the polyurethane curing agent obtained in step (1) at a feed rate of 3g / min, and enter the internal cooling molecular still through...

Embodiment 3

[0037] The preparation method of the polyurethane trimer curing agent of low free isocyanate monomer comprises the steps:

[0038] (1) Under the protection of nitrogen, first put 220g of TDI 100 (all composed of 2,4-TDI) and 210g of isopropyl acetate into the reaction vessel and stir evenly, keeping the temperature at 90°C, then add 4.7g of ethylenediamine Add dropwise in the described reaction container under stirring condition, dropwise time 1.5 hours; When its value is reduced to 24.2%, add 2.2g dimethyl sulfate immediately, keep warm for 2 hours, cool and discharge immediately to obtain polyurethane curing agent.

[0039] (2) The polyurethane curing agent obtained in step (1) is fed into the external cooling thin film evaporator through the distributor at a feed rate of 10g / min. The temperature of the primary separation is controlled at 200°C, and the temperature of the primary cold trap is controlled at 33 ℃, the vacuum degree is controlled at 2000Pa; the temperature of ...

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PUM

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Abstract

The invention discloses a preparation method of a polyurethane trimer curing agent of a low free isocyanate monomer, comprising the following steps of: under the protection of nitrogen, firstly putting an isocyanate monomer and an esters solvent into a reaction container to evenly stir, wherein the temperature is kept at 50-90DEG C; dropwise adding diamine into the reaction container under the condition of stirring, wherein the dropwise adding time is 1-1.5 hours; and after dropwise adding, adding a catalyst of which the mass is 0.1-0.5% of that of the isocyanate monomer once, continuing stirring and reacting at the temperature of 70-100DEG C for 3-6hours, when the NCO base content is 20%-25%, immediately adding the polymerization inhibitor of which the mass is 0.1-1% of that of the isocyanate monomer, keeping the temperature for 1-2hours, and discharging in a cooling way. The polyurethane trimer curing agent prepared by the preparation method can be better compatible with the resin, can be quickly solidified under normal temperature, and has the advantages of being higher in mechanical strength, modulus, adhesion, etc.

Description

technical field [0001] The invention relates to a polyurethane trimer curing agent, in particular to a method for preparing a highly compatible low-free polyurethane trimer curing agent whose free isocyanate monomer content is less than 0.5 percent and NCO group-terminated. Background technique [0002] Polyurethane is an important material involved in industries such as building materials, furniture, coatings, plastics, leather and adhesives. The performance of polyurethane is related to the quality of hundreds of billions of products such as wood furniture, toys, automobiles, leather, shoes and composite films. The coating film of polyurethane coating has the advantages of high hardness, good toughness, strong chemical resistance and fast drying speed. It is one of the most widely used solvent-based coatings with excellent performance. Polyurethane coating is composed of two components, one component is based on alkyd resin, polyester resin and amino resin, and the other ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G18/79C07D251/32C09D175/12
Inventor 张心亚张鑫芳何勇黄洪殷代武王代民曹树潮梅慈云陈焕钦
Owner SOUTH CHINA UNIV OF TECH
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