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Paint crosslinking agent for epoxy resin
2017-8-11 23:48:32
Paint crosslinking agent for epoxy resin
Epoxy resin itself is linear structure of the thermoplastic, and cannot be directly used to application, must add the second component in the resin, under certain conditions, such as temperature or humidity, and the epoxy groups of epoxy resin in addition polymerization, or catalytic polymerization reaction, generating three-dimensional network structure (size) of the crosslinking network structure to use. The compound or resin that ACTS as a second component is the crosslinking agent used in epoxy resins.
Dicyandiamide, also called dicyandiamide, has long been used in the crosslinking agent of epoxy resin and applied to powder coatings, adhesives and other fields. It can be stored at room temperature for up to six months after mixed with epoxy resin. The crosslinking mechanism of dicyandiamide is more complex, and besides the four hydrogenation of dicyandiamide, the cyanide has a certain reaction activity.
Dicyandiamide separately for crosslinking agent of epoxy resin crosslinking temperature is very high, generally between 150 ~ 150 ℃, the temperature of many devices and materials due to the temperature of cannot bear such cannot be used, or because the requirements of production process and must reduce one-component epoxy cross-linking temperature. There are two ways to solve this problem. One is to add the accelerant to reduce the crosslinking temperature without excessively damaging the storage period and performance of dicyandiamide.
Such a lot of accelerator, imidazoles main compounds and their derivatives and salt, urea derivative, organic guanidine derivatives, phosphorus compounds, transition metal complexes and compound accelerator, etc., the accelerator can make dicyandiamide crosslinking temperature decrease, the ideal crosslinking temperature can drop to about 120 ℃, but at the same time can make the storage period shorten, and will be affected by a certain water resistance.
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
Another effective way to reduce the crosslinking temperature of single component epoxy resins is chemical modification of dicyandiamide through molecular design. The introduction of amines in dicyanide molecules, especially aromatic amines, to prepare dicyandiamide derivatives, such as HT 2833, HT 2844, is a chemical dicyandiamide derivative modified with 3, 5, 2 substituted aniline.
According to the report, the crosslinking agent has good intermiscibility with epoxy resin, long storage period, crosslinking speed, crosslinking 1 h under 100 ℃, the shear strength can be up to 25 mpa, 150 ℃ crosslinking 30 min, shear strength can be up to 27 mpa.
In addition, there are the aromatic diamine as 4, 4 'diamino diphenyl methane (DDM), 4, 4' diamino diphenyl ether (DDE), 4, 4 'diamino diphenyl sulfone (DDS), the dimethyl aniline reaction with dicyandiamide (DMB) respectively made its derivatives. After the introduction of benzene ring of dicyandiamide derivative with the intermiscibility of bisphenol A type epoxy resin with dicyandiamide increased significantly, compared with 44 E one-component system consisting of epoxy resin at room temperature storage period for half A year, crosslinking temperature were lower than that of dicyandiamide.
Domestic related to chemical dicyandiamide modified dicyandiamide derivative less reported, using epoxy propane and dicyandiamide reaction with dicyandiamide MD 02, the melting point of 154 ~ 162 ℃, melting point than dicyandiamide (207 ~ 210 ℃) low about 45 ℃, using 100 E 44 epoxy resin, 15 MD 02 and 0 5 2 methyl imidazole formula, gel time under 150 ℃ for 4 min. Using modified dicyandiamide formaldehyde from aniline derivatives with bisphenol A type epoxy resin mixed solubility increases, in A mixture of acetone and alcohol solution has good solubility, and increase the reactivity, storage is longer.
Imidazole, 2 - methyl imidazole, 2 - ethyl - 4 - methyl imidazole, 2 - phenyl imidazole imidazoles crosslinking agent is a kind of highly active crosslinking agent, the temperature in a short time can make epoxy crosslinking, therefore its single component system with epoxy resin composition storage period is shorter, the modification must be, the introduction of large substituent in its molecular form has the space steric hindrance imidazoles derivatives, Cu, Ni, Co or and transition metals, zinc and other inorganic salt reaction to generate the corresponding imidazole salt complex, to become a certain storage period at room temperature latent sexual coupling agent.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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