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Use of epoxy resin paint crosslinking agent
2017-8-13 19:23:40
Use of epoxy resin paint crosslinking agent
For the cross-linking agent and acid anhydride agent, the optimal dosage and optimal crosslinking condition are present in the application.
The optimum dosage is the best crosslinking agent for the performance of epoxy resin. This is determined by the structure of the crosslinking agent itself and the reaction history of the formation of the reticular structure. The optimum amount of crosslinking agent is different. The crosslinking agent is too much or too little, and the nature of the crosslinking is worse than the best use.
1. Optimum dosage of the crosslinking agent of polyamine and solid epoxy resin
For the multi-amine crosslinking agent, the crosslinking mechanical properties and electrical properties reached the highest level in the optimal dosage. The optimum amount is calculated by chemical theory. Take DETA as an example, the molecular weight of the molecule is 103, and the equivalent of the epoxy resin used is 190 (equivalent to 0.526 of the epoxy value), and the theoretical dosage of DETA is (a % = 100%) :
If there are no M and n values, then the maximum heating temperature of different crosslinking agent should be measured by the crosslinking heat curve to determine the better dosage.
For most of the modified amine crosslinking agent, the ratio of the application of epoxy resin are relatively broad, if the crosslinking performance requirement is very strict, can according to the dosage of amine value size to choose matching. In general, the amount of crosslinking agent with high amine value is relatively low, and the amount of crosslinking agent with low amine value is higher.
Acid anhydride epoxy resin crosslinking agent
The addition of acid anhydride cross-linking agent is more complex than amines. Acid anhydride is used alone, unlike using stimulants at the same time. When using accelerator, is due to the reaction mechanism of epoxy resin and anhydride carboxylic acid anion alternating addition polymerization, and hydroxyl of the epoxy group and generated in the reaction of parallel reaction, so the best dosage general for theoretical calculation of the amount of 0.85 times. There's an empirical coefficient here. If the acid anhydride (such as HET) with chlorine is used, the general coefficient is 0.6.
Chinese name: Diethyl toluene diamine(DETDA)Chinese alias: aryl, aryl diethyl - aryl - methyl-p-phenylenediamine
English name: Benzenediamine, ar, ar-diethyl-ar-methyl-English aliases:Diethyltoluenediamine; ar, ar-Diethyl-ar-methylbenzenediamine;Diethylmethylbenzenediamine;
CAS No. :68479-98-1
EINECS No. :270 -877-4
Molecular formula: C11H18N2
Molecular Weight: 178.28
Boiling point: 310 ℃
Refractive index: 1.581
Flash Point: > 140 ℃
Inchi: InChI = 1/C11H18N2/c1-4-8-6-7 (3) 10 (12) 11 (13) 9 (8) 5-2/h6H ,4-5,12-13H2 ,1-3H3 density : 1.022
Risk Codes: R10; R35
RIDADR: UN 3082
Safety instructions: S2; S26; S39; S61
Packing Group: III
Hazard Class: 6.1
The effect of the amount of the epoxy resin crosslinking agent on the performance of the crosslinking agent
The limit of optimum dosage is usually chemical dosage. Due to the low reaction efficiency of crosslinking reaction, the end of the reaction is indefinite. The ideal cross-linking state can be studied by observing the relationship between the addition of crosslinking agent and the performance of crosslinking. Firstly, the relationship between the dosage of amines crosslinking agent and HDT is lower before and after the chemical theory and the highest level of chemical theory.
As crosslinking agent does not have sufficient, epoxy reaction efficiency is low, such as more than when the crosslinking agent reaction efficiency is low, the result is the same low crosslinking density, crosslinking content failed to form the ideal state of network crosslinking, so HDT value is low. This tendency is also applicable to acid anhydride crosslinking agents.
It is not only the HDT, but also the tensile strength and shear strength are the highest in chemical theory. The relationship between DDM and dielectric constant is also true.
The actual use is different, the property requirement is also different. The optimal dosage of HDT is not necessarily the highest. For example, the requirement for thermal shock strength is this: the amount of crosslinking agent is reduced from the optimal dosage, the crosslinking density decreases, and the HDT decreases, but the thermal shock strength rises.
Is a linear thermoplastic resin, epoxy resin itself does not harden, and do not have any performance, only to join the crosslinking agent, to make it by the linear structure/couplet net or body structure, the formation of insoluble molten material, not only has good performance; And the performance of the crosslinking products is largely dependent on cross-linking agents, so. Crosslinking agent is an important component of epoxy resins.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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