Zinc oxide coating crosslinking agent

Zinc oxide coating crosslinking agent

The effect of the addition of zinc oxide coatings on the coating. When zinc oxide is added to the emulsion as a crosslinking agent, it is produced by the interaction of the carboxyl ion through the ionic bond, which is an ionic form.

Made after coating, in the process of film forming, with moisture to evaporate, the latex particle separation from each other's state to state closest packing, which melts into film, during this period of latex particle surface between the concentration of carboxyl can be through the chelation of zinc ions, formation of insoluble salt or complexes. As a result, the relative amount of zinc oxide and functional monomer will have a large effect on coating performance.

With the increase of ZnO content, i.e. n (ZnO) : n (- -) COO value increase, coating drying speed table dry time and work time significantly shortened, coating to burnish, at the same time as the amount of substance ratio increases, adhesion resistance of the coating is good, the hardness increases.

On the glass of water resistance than the increasing of the material first and better, but the amount of substance ratio is 0.5, and with that the increase of the ratio of the amount of weakened slightly, the reason may be that not all carboxyl is arranged on the surface of latex particles, some of the carboxyl group folded inside the colloidal particles, not distributed in the surface, therefore, when the quantity of the material after more than a certain value will be a part of the Zn2 + cannot happen complexation and is free, which affect the water resistance of coating.

Its film also gradually with the increase of the ratio of amount of substance difficult, may be n (ZnO) : n (- -) COO value increases, formation of ion pairs or ion cluster number increase, also enhanced the power of the block each other, have difficulty leads to film molecular chains extend, characterized by high minimum film-forming temperature change. The appropriate n (ZnO) : n (-coo -) value is 0.5 ~ 0.6.

Increases as the amount of acrylic acid is added, the viscosity increases gradually, also improve adhesion, hardness, burnish and antiblocking also increased with the increase of acrylic acid has the obvious enhancement, and on the glass of water resistance, first decreases with the increase of dosage of acrylic acid, and when the acrylic acid content of 7%, and improved slightly with the increase of dosage of acrylic acid.




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).


May be with the acrylic acid content increased, with the formation of zinc ions on or ion is, the more the number of clusters, the interaction between the macromolecular chain also strengthen, make the emulsion viscosity increased some, and due to the increase of crosslinking density, formation of the film in terms of hardness, burnish and antiblocking also gradually show the increase trend. Considering the water resistance of the adhesive film, the addition of acrylic should not be too much, for 7% ~ 9%.

Acrylic monomer addition. Acrylic acid monomer has the strong hydrophilicity, it is affecting - COO - way to add in the distribution of the latex particle surface, it will also affect its and the effect of zinc ion crosslinking.

Can be seen from table 2, acrylic acid used in the shell monomer to add, make its enrichment in the latex particle shell (surface), are more likely to be formed with zinc ions on, crosslinking and more sufficient, therefore has the obvious effect to improve the performance of the coating, its hardness, water resistance and adhesion resistance than the nuclear part of the add and even add increased. And the film temperature is slightly lower, helping to reduce VOC.

ZnO preemulsion added temperature. Using the ZnO preemulsion at room temperature, the ZnO's precipitate and the emulsion are unstable. When the temperature increases, the appearance and stability of the emulsion vary.

With the increase of preparation temperature, crosslinking emulsion appearance change, enhanced stability, appearance has no obvious change after 55 ℃. The coating hardness and with the increase of temperature is an obvious increase, increase is not obvious after more than 55 ℃.

Dry film on the glass of water resistance is poorer, when less than 55 ℃ could be zinc ions is not fully formed with carboxyl ion pair or ion clusters, easily lead to insufficient degree of crosslinking caused precipitation and water resistance, its good resistance to water at 65 ℃, thus optimum temperature of emulsion crosslinking between 55 ~ 65 ℃.

Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd 

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