The main varieties of fillers used in coatings are: calcite powder (heavy calcium), talcum powder, calcined kaolin, washed kaolin, silica ashstone, mica powder, sulphate, quartz powder, dolomite, bump bar soil, synthetic aluminum silicate and so on.
oil absorption: 25-50
characteristics: high whiteness, low cost, stable performance.
use: too broad to
. In the coatings industry, a large number of fillers are used. For primers, it enhances the precipitation and permeability of primers to the base surface, thickens, fills and flattens thickening coatings, thickens, fills and flattens in thick paints, is an ideal anti-light filler in semi-gloss or lightless paints, and in metal rust-proof coatings, hydrolysis produces calcium hydroxide, which can be formed with iron surfaces. Hydrogen bond and enhance the adhesion of the coating film, but also absorb H-plus, used in architectural coatings, low oil absorption, low demand for emulsion, can not only reduce the cost of latex paint, but also play a skeleton role, increase the thickness of the coating film, improve mechanical strength, wear resistance, and so on, and thus become the most commonly used filler latex paint.
Relative to the advantages and disadvantages of light calcium: light calcium oil absorption is large, need a lot of lotion, increased costs;
Mohs hardness: 1
coating: extensive. In the inner wall coating, can improve scrub resistance and construction, for anti-corrosion coatings, because of the extension of the diffusion path of corrosive substances, can improve the protection effect, similar to precipitation silicate, talcum powder can also act as an isolator of pigments, improve the coloring effect of pigments.
: easy to powder, recommended dosing appropriate.
Mohs hardness: 3-4
oil absorption: 50-95
ratio surface area: 8-16
features: can improve paint tentacles and precipitation resistance, no effect on deflow degeneration, has a light-eliminating effect, increase whiteness and cover.
: water absorption is larger, not suitable to improve the tentacles of the coating, not suitable for the preparation of water-repugnance coating.
needle or fibrous structure
fold rate: 1.62
mohs hardness: 4.5-5.0
with enhanced, reduced crack sensitivity, a certain amount of thickening and tentacles.
In the coating industry: can be used as a system pigment and incremental agent practical, it can increase the bright color of white paint, without reducing the whiteness of the coating and cover, can replace part of the titanium white, and can maintain this tone for a long time.
Silica ash oil absorption is low, has a good filling capacity, can reduce the cost of coating
silica ash needle crystallization makes it a good paint suspension agent, so that the precipitation of color paint is soft and easy to disperse;
In addition to water-based coatings, can also be used for primers, intermediate coatings, oily coatings, road sign coatings, etc.;
in asphalt coatings to replace asbestos;
silica ash used in coatings, can improve the wear resistance and weather resistance of coatings, the reason is in contrast with its needle and fiber structure, in the coating, in addition to increasing the shielding of the coating film, there is a strong UV resistance.
: Replacing 20% titanium with it does not change the opacity and other properties of the coating film; Water is much easier to diffuse into these pigment particles than to latex particles, and after drying, a subtle air/silicon dioxide interface is formed in the fused emulsion coating film, which improves the opacity of the coating film.
off-topic: most of the so-called silica ash on the market today is mainly a mixture of heavy calcium and silica ash.
to do an experiment: take out some silica ash, drop hydrochloric acid into it,
out a large number of bubbles, indicating that it is mixed with a large amount of heavy calcium.
the gas emitted by the caCO3-2HCl-CaCl2-H2O-CO2
is carbon dioxide.
glassed paste, indicating that it is silica ash.
main component of silica ash is calcium silicate, which
H2SiO3 is silicate, glassy.
Sulphate (heavy crystalline powder)
refractive index: 1.63-1.65
oil absorption: 9
sulphate acid resistance, alkali resistance, light resistance, heat resistance, melting point of up to 1500 degrees C, insoluble in water, low oil absorption.
: high density, easy to precipitate, appropriate selection of a higher fine, do a good job of thickening system. OK
is mainly used in the coating industry primer, the use of its low oil absorption, low paint consumption, can be made into a thick film primer, good filling, smoothness, non-permeability, increase the hardness and wear resistance of the coating film.
high refractive index of radon sulfate, which is mainly used in ton paint, can save a lot of expensive slurry costs.
mica is a fine-grained white cloud mother, a silicate of a layered structure consisting of two layers of silicon-oxygen tetrys sandwiched with a layer of aluminum-oxygen octa-faceted layer. Chemical K2O3Al2O3.6SiO2.2H2O, the crystal is scaly, elastic and bendable.
oil absorption: 20-50
mica has good acid resistance, alkaline resistance, good chemical stability, moderate dry cover and good suspension.
can be used in coatings to improve the weather resistance of the coating, prevent water vapor penetration, prevent cracking, delay powdering.
addition of mica to the formula containing talc powder, the corrosion resistance of the coating is improved, the surface hardness is increased, the resistance to scrubs is improved, and the pigment efficiency is improved.
synthetic aluminum silicate
synthetic aluminum silicate is actually a kind of aluminum silicate sodium, is a non-fixed-shaped highly dispersed institutional pigment.
Average particle size: 1.5 m
oil absorption: 75-150
small particle size, narrow particle size distribution, no Precipitation layering phenomenon, is the suspension of the paint greatly improved, is the paint color purity, color strength, cover force improvement, can improve the dispersion and fineness of the paint indicators, the appearance of the paint, gloss, fullness, hardness have a good effect.
synthetic aluminum silicate does not act with phosphate dispersants, latex paint has good dispersion stability. The ultra-fine properties and high dispersion of synthetic aluminum silicate can make latex paint slightly thicken to prevent pigment precipitation and surface layering.
the film resistance and weather resistance of the other latex paint will not be reduced by the addition of ultra-fine aluminum silicate, replacing 10-20% of the amount of titanium dioxide, the coating cover will not be weakened.
Reasonable use of aluminum silicate instead of some titanium production of latex paint will have the following characteristics:
due to small particle size, narrow particle size distribution, no precipitation layering phenomenon, filler suspension greatly improved, good can opening effect.
paint color pure, strong coloring force, cover force increased.
the coating's dispersion and fineness indicators have improved the appearance, gloss, fullness, hardness and dispersion of the coating have a good effect.
the production cost of coatings by saving 10-20% on titanium dioxide.
In addition, synthetic aluminum silicate is alkaline, which acts as a buffer against acid alkalinity in coatings, especially in the latex paint system of ethylene acetate, which can prevent the pH of latex paint from decreasing due to hydrolysing of vinyl acetate in the storage process.
disadvantages: because it is larger than the surface area, high oil absorption, and must be completely dispersed in order to play its efficiency, otherwise it is easy to cause post-thickening. In addition, it has a de-lighting effect and should not be used in highlight paint.