Modified epoxy coating crosslinking agent

Modified epoxy coating crosslinking agent

The synthesis of acrylic modified epoxy resin is a radical polymerization mechanism. Epoxy resin is unsaturated double bond, but contains ether bond, its alpha H ortho carbon atoms and the H atoms on the tertiary carbon atom is relatively more lively, can be formed under the effect of the initiator free radicals, triggering grafting reaction. An alpha-h in one chain of epoxy resin is an example of the possible mechanism of reaction.

Take a certain amount of epoxy resin soluble in propylene glycol monomethyl ether and n-butyl alcohol in the mixed solvent, dissolves to join with a thermometer, mixer, condenser pipe flask, four under N2 protection, the system temperature up to 110 ℃; Then according to the formula of methyl acrylic acid, butyl acrylate, styrene, vinyl three (beta - methoxy) ethoxy silane and BPO mixed monomer droplets to the reaction system, 2 h and complete; 3 h temperature to 116 ℃, the heat preservation; Temperature to 80 ℃, add a certain proportion of N, N - dimethyl ethanolamine and salt, then add a certain amount of deionized water, fast mixing, waterborne epoxy emulsion.

Preparation:

(1) the dispersant, dispersant, wetting agent, defoaming agent, bentonite, pigment, anti-rust pigment, and fillings in the dispersing cauldron are put in sequence.

(2) grind the above slurry through the grinder until it is less than or equal to 30um.

(3) mixing epoxy emulsion, leveling agent, antifoaming agent and antirust agent into the ground paste.

(4) measure PH, add a moderate amount of PH, and PH between 8 and 9.

(5) the curing agent should be added in proportion, stir well, and be ready for construction after 20 minutes.




Chinese name: Diethyl toluene diamine(DETDA)

Diethyltoluenediamine packing： net weight 200KG/ galvanized iron drum (a small cabinet pallet loaded 16 tons), 1000KG/IB barrels (a small cabinet loaded 18 tons or 23 tons of ISOTANK).


The effect of organic silicon on performance. Organic silicon has good thermal stability, oxidation resistance, weather resistance, good low temperature performance, low surface energy, high dielectric strength, etc. The organic silicone modified epoxy resin is developed in recent years can not only reduce the internal stress of epoxy resin, and can increase the toughness of epoxy resin, such as resistance to high temperature performance of the effective way. In this experiment, the effects of organosiloxane on the properties of emulsion stability were compared.

With experiment shows that when using vinyl three (beta - methoxy) ethoxy silane than emulsion dispersed more even when not in use, and with amine propyl methyl 2 ethoxy silane, emulsion performance improvement is not obvious, but it consumes epoxide group, impact on the performance of the late film, therefore, all classes amino silane should not be used, so choose vinyl silane, from price and late, and therefore consider comprehensive performance of vinyl choose three (beta - methoxy) ethoxy silane as a modifier.

The results show that when organosiloxane is less than 3%, it is not very different from non-performance. When the dosage is greater than 4%, the size of the emulsion is wider and less stable.

Therefore, the dosage of organosiloxane should be controlled between 3-4%.
Introducing carboxyl functional groups in epoxy resin has the water soluble, acid value, the higher the spread more easily, but poor water resistance of the resin, acid value is too low, scattered difficult, preparation of the emulsion is unstable. In the experiment, a series of comparison experiments were made for acid value, and the numerical value was 0-5, and the higher the numerical value, the better the performance.

The results showed that when the acid was less than 45 (KOH) mg/g, the size of the emulsion was wide and unstable. And when the acid value of more than 90 mg/g (KOH), the stability of the emulsion and particle size distribution of basic stable, little change, but the acid value is too large, the late film had a greater influence on the resistance to water, so the appropriate control acid value in 60-90 mg/g (KOH).

Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd 

Diethyl toluene diamine(DETDA)  http://www.yaruichem.com