News Details
Polyurethane paint for crosslinking agent
2017-3-7 22:57:57
Polyurethane paint for crosslinking agent and non-ionic and ionic blending modification.
At present, the polyurethane crosslinker hydrophilic modification methods is given priority to with non-ionic modification, but the method of modified crosslinking agent water resistance is poor, crystallization and orientation; Anion to improve the water resistance performance but have higher request for pH, rather than ion and ion mixing modification, can overcome the above defects.
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.
With the development of water-borne polyurethane, waterborne polyurethane crosslinking agent also got rapid development. 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 hydrophilic group introduced too much can lead to coating poor water resistance, chemical resistance, applicable period short; In the construction process of blocking agent deblocking temperature is higher.
As a result, the preparation of water dispersion of good performance, low deblocking temperature high-performance water-based polyurethane crosslinking agent is the key research direction in the future.
Bisulfite salt blocking agent
Sodium bisulfite prices are lower and environmental protection free from contamination, closed by polyurethane crosslinker deblocking temperature is low, a 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, lactam type is also commonly used sealants, such sealants are mainly caprolactam, acetanilide, N - methyl ethyl amide, and so on. 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.
Polyurethane as the main chain containing - NHCOO - repeating structural unit of polymer, PU abbreviations, including rigid polyurethane plastics, soft polyurethane plastics, polyurethane elastomer, a variety of forms, and divided into two major categories of thermoplastic and thermosetting. The status of raw material with resin commonly present.
As well as the component from a single material, polyurethane can also generate composite materials and other materials.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
At present, the polyurethane crosslinker hydrophilic modification methods is given priority to with non-ionic modification, but the method of modified crosslinking agent water resistance is poor, crystallization and orientation; Anion to improve the water resistance performance but have higher request for pH, rather than ion and ion mixing modification, can overcome the above defects.
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.
With the development of water-borne polyurethane, waterborne polyurethane crosslinking agent also got rapid development. 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 hydrophilic group introduced too much can lead to coating poor water resistance, chemical resistance, applicable period short; In the construction process of blocking agent deblocking temperature is higher.
As a result, the preparation of water dispersion of good performance, low deblocking temperature high-performance water-based polyurethane crosslinking agent is the key research direction in the future.
Bisulfite salt blocking agent
Sodium bisulfite prices are lower and environmental protection free from contamination, closed by polyurethane crosslinker deblocking temperature is low, a 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, lactam type is also commonly used sealants, such sealants are mainly caprolactam, acetanilide, N - methyl ethyl amide, and so on. 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.
Polyurethane as the main chain containing - NHCOO - repeating structural unit of polymer, PU abbreviations, including rigid polyurethane plastics, soft polyurethane plastics, polyurethane elastomer, a variety of forms, and divided into two major categories of thermoplastic and thermosetting. The status of raw material with resin commonly present.
As well as the component from a single material, polyurethane can also generate composite materials and other materials.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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