The development of modern coatings technology
The coating is the development trend of low - high solid glue, in order to obtain:
Better performance of paper: improve the surface properties, such as intensity, the coverage and glossiness;
Better fuel economy, reduce the energy consumption of dry, improve the speed, the use of more cheap chemicals, such as calcium carbonate.
High solid content paint the following problems for a long time, has affected the development of high solid content paint:
Coating rheological property would decline. Paint viscosity, high shear viscosity rise, flow and pumping difficulties;
Paper disease increased. After coating solid content, coating of flocculation increase, increase coating streaks;
The coating weight control difficult. Coating of high shear viscosity increased rapidly under the high solid content, are likely to rise to the point of coating scraper is hard to control.
Therefore, urgent need to solve a chemical coating at high concentrations are faced with the problem. this
Chemicals is rheological modification agent.
Rheological modification agent by package in pigment particle surface, so as to achieve the following functions:
Scattered to prevent flocculation
The rheological effect;
Dynamic water.
Dahflow rheological modification agent, making the coating of the pigment particles dispersed in full, makes paint a very uniform dispersion. At the same time, to form a thick layer of protective layer on the outside of the pigment particles to the high solid content (> 70%) for coated paper coating of paint, reduces the paint flocculant poly, keep paint good dispersion;
Coating evenly dispersed, and can reduce the happening of the disease such as scratches, at the same time improve coating coverage and absorbent properties, which make the coated paper coverage, gloss, smoothness, opacity and print uniformity and a series of performance improvement;
Coating dispersed evenly, can make adhesive role into full play, thus improve the compressive strength, compressive strength if they remain unchanged, can reduce the dosage of adhesive.
Rheological modification agent on the outside of the pigment particles with a thick layer, high concentrations, flow coating reduces friction between the pigment particles, paint viscosity decreased;
Paint viscosity decline, so that we can make a higher solid content of coatings, in order to gain a better coating (such as scraper load is reduced, blade back flow reduce, etc.) and paper properties (luster, strength and to increase the coverage, etc.).
Rheological modification agent not only wrapped in pigment particle surface, keep the coating of pigment particles dispersed, but also between the pigment particles, forming a weak association with, to a certain extent, to prevent the flow of the water in the coatings. So has the capability of dynamic water;
The performance of rheological modification agent, enable it to thickening part, water retention agent.
