News Details
Replacement of dicyandiamide paint crosslinking agent
2017-8-29 12:21:41
Replacement of dicyandiamide paint crosslinking agent
The representative varieties that replace the crosslinking agent of dicyandiamide are o-tolyl-biguanide.
The replacement of dicyandiamide crosslinking agent was obtained through the presence of dicyandiamide and o-toluidine in hydrochloric acid. Neighbors - cresyl two guanidine has about 136 ℃, melting point introduction of adjacent cresyl was improved and the compatibility of bisphenol A epoxy resin, and it has the very high functionality, so compared with dicyandiamide crosslinking performance is greatly improved, recommended by the crosslinking temperature is 160 ℃ / 20-180 ℃ for 10 minutes. However, in order to further achieve lower crosslinking temperature, it is better to use the accelerant, such as 2-methylimidazole. Its chemical equivalent approximately 37, the recommended dosage of resin per hundred of E - 12 meter about 4 to 5, if further add 0.1-0.3-2 - methyl imidazole, can make the crosslinking temperature below 140 ℃.
With adjacent - methyl benzene guanidine (OTB) preparation of pure epoxy system has excellent resistance to yellowing, flexibility and electrical insulating properties, so the coating system is recommended for decorative purposes and some corrosion such as spring and other electrical insulating powder.
Dicyandiamide, also known as dicyanide, has long been used as a potential coupler. Applied to powder coating, adhesive 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 alone when used as a 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.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine Raw material ：
TDA industrial, Sichuan production
Ethylene (Et) polymer grade, Shanghai production
TEA industrial imports
The representative varieties that replace the crosslinking agent of dicyandiamide are o-tolyl-biguanide.
The replacement of dicyandiamide crosslinking agent was obtained through the presence of dicyandiamide and o-toluidine in hydrochloric acid. Neighbors - cresyl two guanidine has about 136 ℃, melting point introduction of adjacent cresyl was improved and the compatibility of bisphenol A epoxy resin, and it has the very high functionality, so compared with dicyandiamide crosslinking performance is greatly improved, recommended by the crosslinking temperature is 160 ℃ / 20-180 ℃ for 10 minutes. However, in order to further achieve lower crosslinking temperature, it is better to use the accelerant, such as 2-methylimidazole. Its chemical equivalent approximately 37, the recommended dosage of resin per hundred of E - 12 meter about 4 to 5, if further add 0.1-0.3-2 - methyl imidazole, can make the crosslinking temperature below 140 ℃.
With adjacent - methyl benzene guanidine (OTB) preparation of pure epoxy system has excellent resistance to yellowing, flexibility and electrical insulating properties, so the coating system is recommended for decorative purposes and some corrosion such as spring and other electrical insulating powder.
Dicyandiamide, also known as dicyanide, has long been used as a potential coupler. Applied to powder coating, adhesive 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 alone when used as a 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.
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
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.
Another effective way to reduce the crosslinking temperature of single component epoxy resins is chemical modification of dicyandiamide through molecular design. Introduction of amine in the dicyandiamide molecules, especially the structure of aromatic amine, in the preparation of dicyandiamide derivative, such as Switzerland Ciba Geigy company development of HT 2833, HT 2844 is a 3, 5 two to replace aniline modified dicyandiamide derivative, its chemical formula is as follows:
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. There were reports of the use of aromatic diphenylenediamine (DDM), 4, 4 'diaminodiphenyl ether (DDS), 4, 4' diaminodiphenyl sulfone (DDS), and the reaction of dimethyl aniline (DMB) and 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.
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 of formula, the gel time under 150 ℃ for 4 min. Using aniline and formaldehyde of the modified dicyandiamide derivative 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.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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.
Another effective way to reduce the crosslinking temperature of single component epoxy resins is chemical modification of dicyandiamide through molecular design. Introduction of amine in the dicyandiamide molecules, especially the structure of aromatic amine, in the preparation of dicyandiamide derivative, such as Switzerland Ciba Geigy company development of HT 2833, HT 2844 is a 3, 5 two to replace aniline modified dicyandiamide derivative, its chemical formula is as follows:
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. There were reports of the use of aromatic diphenylenediamine (DDM), 4, 4 'diaminodiphenyl ether (DDS), 4, 4' diaminodiphenyl sulfone (DDS), and the reaction of dimethyl aniline (DMB) and 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.
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 of formula, the gel time under 150 ℃ for 4 min. Using aniline and formaldehyde of the modified dicyandiamide derivative 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.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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