Waterborne paint crosslinking agent unsealed

Waterborne paint crosslinking agent unsealed.Han-qing zhang with isocyanate trimer and DMPA as a raw material for chain extension reaction, again with 3, 5 - dimethyl pyrazole (DMP) for sealants, the remaining NCO group closed, with 2 methyl diethanolamine (activity) and finally into a salt, of water crosslinking agent can implement unsealed at lower temperatures.

Non-ions and ions are mixed. At present, polyurethane crosslinking agent is based on non-ionic modification, but the modified crosslinking agent is water-resistant and has crystallization tendency. It is possible to overcome the above defects by improving the ability of the anionic ion to improve the water resistance but the higher requirements for the pH, not the mixing of ions and ions.

Laas etc with HDI trimer, dihydroxy methyl propionic acid (DMPA), poly (ethylene glycol, propylene glycol) butyl ether reaction made with storage stability of aqueous polyurethane crosslinking agent, the crosslinking agent can not only reduce the crystallization tendency, also can improve the water resistance of coating film, has a good coating performance.

Sulfite sealant. Sodium sulphate is cheap and pollution-free, and the enclosed polyurethane crosslinking agent has a low temperature and high application value.

Zhang to polyether diol (N210), IPDI as main raw material, sodium bisulfite as closed agent synthesis of waterborne polyurethane crosslinker, the results showed that the optimal condition was closed for: 45 min 20 ℃ response, n (NaHSO3) : n (NCO) = 1.1, deblocking temperature 76 ~ 130 ℃.

Hu Peng etc with TDI and PEG - 400 as the main raw material to synthesize polyurethane pre polymers, NaHSO3 as sealants closed to pre polymers, the results show that under the optimal conditions, NaHSO3 of isocyanate base sealing effect is good, the product of the deblocking temperature between 56.3 ~ 68.4 ℃.




Chinese name: Diethyl toluene diamine(DETDA)

Diethyltoluenediamine Raw material ：

TDA industrial, Sichuan production

Ethylene (Et) polymer grade, Shanghai production

TEA industrial imports

A reagent grade additives


But NaHSO3 blocker has poor stability, low rate of closed defects, and NaHSO3 not well compatible with isocyanate, if NaHSO3 was achieved by organic solvent and the compatibility of polyurethane crosslinker, cause necessarily volatile organic compounds (VOC) content is higher, has certain pollution to the environment.

Yang Yongjiang by IPDI, DMPA, poly (ether such as multivariate alcohol and active base nonionic hydrophilic compounds (AD) as the main raw material, NaHSO3 as sealants, into salt before sealing side, avoid the use of organic solvents, low VOC content was synthesized, the closed rate high water-based polyurethane crosslinking agent. The results showed that the isocyanate group is completely closed, the product of the deblocking temperature between 97.5 ~ 130 ℃.

Amide, imide, and lactam are also commonly used as sealing agents, such as caprolactam, acetanilide, n-methylamide, etc. Malonic diethyl ester, ethyl acetoacetate, acetyl acetone containing active methylene material such as hydrogen by means of the active methylene react with isocyanate to also can have the effect of blocking agent.

With the development of water-based polyurethane, water-based polyurethane crosslinking agent has also been developed rapidly. But waterborne polyurethane crosslinker still faces some problems, such as isocyanate NCO groups, easy to react with water to generate CO2 residue in the film influence on the performance of the coating appearance and reduce the decoration;

The excessive introduction of hydrophilic groups can result in water-resistant, chemical resistance and short duration of coating. The sealing agent of the sealing agent is higher in the process of construction. Therefore, the high performance water-based polyurethane crosslinking agent, which is good for the preparation of water dispersion and low temperature, is the important research direction in the future.

In the N, N - dimethyl cyclohexylamine and molar ratio of amino sulfonic acid was 1.05, the temperature is 100 ℃, reaction time was 4 h, amino sulfonic acid dosage was 2.5% ~ 3.0% under the condition of preparation of high performance, easy to spread to water-based polyurethane crosslinking agent.

Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd 

Diethyl toluene diamine(DETDA)  http://www.yaruichem.com