Application of calcium carbonate powder in painting industry
Application of calcium carbonate powder inpainting industry
The role of calcium carbonate in latex paint:
As an extender pigment, calcium carbonate has a filling effect to make it delicate, uniform and high whiteness.
Calcium carbonate has a certain degree of dry covering power. Generally, ultra-fine calcium carbonate powder are used. When the particle size is close to that of titanium dioxide, the covering effect of titanium dioxide can be improved.
It can improve the strength, waterresistance, dryness and scrub resistance of the paint film.
Reduce costs and use 10%-50%.
For example, ultrafine heavy calcium carbonate powder materials have significant effects on shortening the dispersion and sanding time in the production process of latex paint, increasing hiding power, improving latex viscosity, reducing the amount of titanium dioxide and improving the polishing performance of putty.
When designing paint formulations,high-performance latex paint uses ultrafine calcium carbonate, and low-gradelatex paint selects heavy calcium with relatively coarse particle size and lowoil absorption.
At present, the application effect of heavy calcium carbonate powder in interior wall latex paint is better. Its particle size control d97<10μm, d50 is about 1.5μm, whiteness>95%, CaCO3≥98%.
Calcium carbonate for car paint
When a car is driving, the bottom of thecar and the wheel fenders are often impacted by sand, gravel and sewage.Therefore, the coating applied on the surface of the substrate is easilydamaged and loses its anti-corrosion ability. Quickly rust and wear out.
In order to solve this problem, it isnecessary to coat undercarriage with sand and gravel resistance and corrosionresistance on these parts. PVC plastisol is a kind of automobile chassis paint,which is mainly composed of PVC paste resin, plasticizer, filler (calciumcarbonate), stabilizer, tackifier, solvent and other additives.
The amount of calcium carbonate accounts for nearly 30% of the total components (the specific amount depends on the formula), and the addition of nano-calcium carbonate will greatly improve the rheological properties of the system and the membrane performance compared to ordinary calcium carbonate. Impact resistance.
Automobile chassis paint is required to beeasy to spray, low viscosity, and good fluidity during the construction andspraying process. After construction, the viscosity is required to be large toprevent sticking and sagging. This requires that the viscosity of the paint becomessignificantly lower at high shear speeds, and it can be easily sprayed andleveled; and at low shear speeds or at a static state, it has high viscosity,which can prevent the paint from sinking and sagging. This kind of performanceis called thixotropy, and nano calcium carbonate products can meet thisrequirement well in terms of construction performance and structuralperformance