News Details
Imidazole and its derivative crosslinking agents
2017-5-3 16:27:35
Imidazole and its derivative crosslinking agents. A simple substitution of imidazole for powder coatings, mainly 2-methyl-imidazole, 2-phenylediazole, and long chains, etc. Although these simple imidazole can provide high crosslinking activity, but as a result of its melting point is generally higher, difficulty and epoxy evenly dispersed, low activation temperature (82-87 ℃) and epoxy resin blend to storage period is shorter, therefore, this kind of imidazole is usually not as a single crosslinking agent used in low temperature crosslinking system,, usually as a crosslinking agent and crosslinking agent used in combination with other. For example and added in the system of epoxy/dicyandiamide 0.1% - 0.3% of the weight of the 2 - methyl imidazole, can make the crosslinking temperature down to about 160 ℃.
In order to overcome the disadvantage of simple imidazole epoxy crosslinking agent and the insufficiency, the simple modification, imidazole compounds of active point on the imidazole molecule (secondary amine and tertiary amine) passivation, appropriate to reduce the reactivity, improve its compatibility with epoxy resin, at the same time also can give other special performance.
There are several types of imidazole derivatives that have been applied in powder coatings.
Most typical can be used in powder coating imidazole derivatives of Japan into a corporation Curezol series of imidazole derivatives, such products of imidazole 1 bit is a passivation, such as - CN instead of the group. Usually these replace groups will reduce the reactivity of such compounds and melting point, improve applicable period/pot life of the product, so when applied to the powder coatings can improve its storage stability.
Further polybasic acid reaction, with the CN series products can get imidazole polybasic acid (generally USES partial third benzene anhydride) adduct (CNS) series products, its counterpart trade names respectively C11Z - CNS and 2 p z - CNS.
The imidazole can also be derived from the series of melamine compounds. The typical product in this series is 2, 4-diamine-6 - [2] -methyl-p-triazine.
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
Other Curezol products and basic properties that can be used in powder coatings. These products are provided by four countries and applied in the field of insulating powder coatings, such as embalming and electronic irrigation.
Curezol series products most starting point and the activity of epoxy resin reaction temperature is lower than 150 ℃, thus has good low temperature crosslinking properties, but in order to guarantee system of powder processing and storage stability, had better choose the variety of the initial activation temperature greater than 90 ℃. Of course these imidazole compounds can be used as crosslinked promoters and other crosslinking agents to reduce the crosslinking temperature or shorten the crosslinking time.
In the case of powder coating, the viscosity of the system is very large due to the lack of solvent. This is due to the fact that the vortices of viscosity and temperature are negligible, and the gradient of surface tension will be an important driver of the vortex. Therefore, in order to reduce the phenomenon of orange peel, the surface tension gradient should be reduced to reduce the vortex amplitude.
Shrinkage cavity formation is the main reason of the low surface tension of the material (shrinkage cavity body) in the molten fluid surface spreading, the size of the shrinkage cavity is associated with the difference of surface tension, as shown in the figure below, the gap between surface tension, the shrinkage cavity body rapidly spreading in the molten powder coating surface, surface area rapidly expand, and because the lower fluid viscosity resistance cannot quickly fill enlarge the volume of below the surface, causing surface subsidence.
It is also partly because of the low surface tension material that is rapidly expanding, and the viscosity of the surrounding fluid has a blocking effect on its expansion. Finally, the shrinkage cavity high in part because of shrinkage cavity at the bottom of the body with some particles inside, the substance is high surface tension, low surface tension surrounding material to its spreading.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
In order to overcome the disadvantage of simple imidazole epoxy crosslinking agent and the insufficiency, the simple modification, imidazole compounds of active point on the imidazole molecule (secondary amine and tertiary amine) passivation, appropriate to reduce the reactivity, improve its compatibility with epoxy resin, at the same time also can give other special performance.
There are several types of imidazole derivatives that have been applied in powder coatings.
Most typical can be used in powder coating imidazole derivatives of Japan into a corporation Curezol series of imidazole derivatives, such products of imidazole 1 bit is a passivation, such as - CN instead of the group. Usually these replace groups will reduce the reactivity of such compounds and melting point, improve applicable period/pot life of the product, so when applied to the powder coatings can improve its storage stability.
Further polybasic acid reaction, with the CN series products can get imidazole polybasic acid (generally USES partial third benzene anhydride) adduct (CNS) series products, its counterpart trade names respectively C11Z - CNS and 2 p z - CNS.
The imidazole can also be derived from the series of melamine compounds. The typical product in this series is 2, 4-diamine-6 - [2] -methyl-p-triazine.
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
Other Curezol products and basic properties that can be used in powder coatings. These products are provided by four countries and applied in the field of insulating powder coatings, such as embalming and electronic irrigation.
Curezol series products most starting point and the activity of epoxy resin reaction temperature is lower than 150 ℃, thus has good low temperature crosslinking properties, but in order to guarantee system of powder processing and storage stability, had better choose the variety of the initial activation temperature greater than 90 ℃. Of course these imidazole compounds can be used as crosslinked promoters and other crosslinking agents to reduce the crosslinking temperature or shorten the crosslinking time.
In the case of powder coating, the viscosity of the system is very large due to the lack of solvent. This is due to the fact that the vortices of viscosity and temperature are negligible, and the gradient of surface tension will be an important driver of the vortex. Therefore, in order to reduce the phenomenon of orange peel, the surface tension gradient should be reduced to reduce the vortex amplitude.
Shrinkage cavity formation is the main reason of the low surface tension of the material (shrinkage cavity body) in the molten fluid surface spreading, the size of the shrinkage cavity is associated with the difference of surface tension, as shown in the figure below, the gap between surface tension, the shrinkage cavity body rapidly spreading in the molten powder coating surface, surface area rapidly expand, and because the lower fluid viscosity resistance cannot quickly fill enlarge the volume of below the surface, causing surface subsidence.
It is also partly because of the low surface tension material that is rapidly expanding, and the viscosity of the surrounding fluid has a blocking effect on its expansion. Finally, the shrinkage cavity high in part because of shrinkage cavity at the bottom of the body with some particles inside, the substance is high surface tension, low surface tension surrounding material to its spreading.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
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