Non metallic mineral powder filler modification application in architectural coatings-Iota

Products

News

Office Address:	Sunmoon Science Park, 985 Xingzhong Road, High-Tech Zone, Bengbu, China
Factory Address:	Mohekou Industrial Park, Huaishang District, Bengbu, Anhui, China
Contact:	Nathan Zhang
Phone:	0086-552-19805521900
FAX:	0086-552-3822922
Mobile:	19805521900/18119733779
WebSite:	www.siliconeoil.cn www.siliconeoil.net
Email:
QQ:	729118868

Service > Non metallic mineral powder filler modification application in architectural coatings

Non metallic mineral powder filler modification application in architectural coatings

REVIEW
Architectural Coatings as a decoration of the building, protected by brushing the surface of the building material, requires a certain degree of fineness, adhesion, hiding power, stain resistance, abrasion resistance, aging resistance, heat resistance, leveling, shorter Properties of drying time, the appropriate minimum film-forming temperature. When a conventional formulations prepared mainly the performance architectural coatings would require its modification.

Because of non-metallic mineral having other mineral materials do not have the variety of features, such as plasticity, viscosity, high strength and chemical stability, so people in the preparation of architectural coatings, often adding a variety of non-metallic mineral materials for improving or Enhanced Performance Coatings certain aspects, but also can reduce the cost of paint.
Preparation of modified architectural coatings, commonly used several non-metallic minerals are bentonite, diatomite, kaolin and rectorite like. Bentonite is a montmorillonite as a main component, and many minerals such as kaolinite, allophane and associated chlorite clay minerals an extremely important; a hydrated clay, diatomaceous earth is magnesium, aluminum, silicon, ore, the main ingredient is mainly kaolinite, water mica, smectite and a small amount of quartz, feldspar and organic matter; kaolin is kaolinite as the main body by a variety of aqueous aluminum silicate clay mineral composition of the mixture; tired Tropsch stone is a kind of mica by a montmorillonite unit cell layer and layer-ordered mixed layer clay minerals rare structure in special natural conditions. Several more non-metallic minerals in architectural coating modified mainly in the following aspects.
1 improve the coating dispersion, stability
Bentonite-layered silicate mineral, with excellent hydrophilic, and the amount of water combined into a gel-like, in the water can release charged particles, electrical exclusion of such particles so that it has good dispersion in the paint, suspension , stability and other characteristics, so often used as a dispersing agent in coatings. Bentonite, sodium silicate and water as raw materials for preparing aqueous inner coating, tests showed that adding the right amount of bentonite in the aqueous interior wall paint coating system out more evenly dispersed than normal paint (not easy to precipitation), more water, more smooth paint film smooth and uniform color retention, better weather resistance.
Mineral montmorillonite type crystal structure belongs 2:1 layered silicate, the two structural units layer (Si-A l) -O tetrahedral intermediate of a [Al (Mg, Fe) - (O, OH) ] octahedra, the existence of a structural unit layer cation aliovalently isomorphous replacement, so montmorillonite cell like a live "big anion" has the ability to adsorb cations, but the binding force between the weak anion and cation These cations can be exchanged. For this reason, montmorillonite coating film-forming material may generate organic molecule polarity genes "montmorillonite - organic molecules" complexes, such complexes generate irreversible once, after dehydration becomes hydrophobic substance thereby increasing the water resistance of the coating.
Polyvinyl alcohol (PVA), precipitated calcium carbonate, talc, bentonite, amount of aid for the raw material of the coating. The results showed that the addition of bentonite paints and coatings compared not add bentonite, water resistance becomes the 1d 7d, the film can not afford to become the dusting powder. Kaolin industry as a paint additive can improve the storage stability of the coating system, brushing resistance, moisture absorption and impact resistance and other mechanical properties, but also to improve the pigment of the anti-flooding and floating.
Washed with water and kaolin, titanium dioxide, calcium carbonate, and so many coalescent prepared architectural coatings, tests found that the use of kaolin coating obtained after long-term storage, the surface did not find other latex paint common watershed phenomenon. Test also measured: containing 15% kaolin latex paint thixotropic index of 3.8, while the same amount of calcium carbonate, kaolin replace obtained after latex paint thixotropic index of 2.5, indicating that contain kaolin Coatings having good thixotropy, storage stability. This will not sag in the construction, also has a good leveling. Using kaolin as additives to help meet the increasingly stringent performance and durability requirements of many of the proposed coating. When asked to preparation of low VOC, high solids coatings and requires thinner and unblemished smooth, shiny coating, especially when the case.
Since rectorite fine clay particles which aluminum silicate mineral structure Si-O tetrahedron and Al-O octahedral hydroxyl group or an oxygen atom and a silicone resin sheet in alkoxy or epoxy resin hydroxy with an epoxy group to form hydrogen bonds, forming interwoven mesh structure so rectorite mineral and organic coatings coupled to each other, so that the viscosity and increase the consistency of the system, serve to prevent or slow down the paint to fill mineral pigment sedimentation.
In silicone resin, titanium dioxide and other raw materials, calcium RECTORITE replace part silicone resin coating filler material, after the dry film coating system, bake at 200 ℃ 3h, tests showed that calcium-based Pareto stone for high temperature coatings, coating firmly attached, no blistering off phenomenon, and placed no precipitation agglomeration process is relatively stable, appearance of the coating quality improved significantly. After sodium modification rectorite dispersed in water, the electric potential is increased, the particle is not easy to have a good suspension flocculation effect.
In order to prepare the coating rectorite field test confirmed suspensions, rectories in coating suspension and thixotropy, leveling coating, brushing type, anti-crack resistance, strength and temperature resistance coating surface and other indicators are better than bentonite suspensions formulated coating.
2 improve the coating hiding
As a white filler, kaolin itself does not hiding, but with a certain ratio is added to the coating, can act as brightening agents to improve the coating hiding power. Kaolin additive has been in almost all types of water-based and solvent-based coatings are used for a wide variety of pigments extended. There is a manufacturer in a building with an alkyd paint to a high-brightness fine kaolin additive replaces the 8% to 10% of the colored pigment, the results paint performance is almost nothing changes.
US Enge Lhard company in a brilliant fine kaolin products to replace 17% of phthalocyanine green pigment and 14% of titanium dioxide, the resulting coating has a high reflectivity and color intensity. This is because the kaolin particles improves the spacing between the pigment particles. Kaolin based pigments having hiding power without sacrificing gloss, pencil hardness, flexibility and other properties, but also its ability to improve the performance.
Choose from a mineral source, processing methods, recipes and other aspects to improve, to do a series of tests, kaolin and calcium carbonate were used instead of 15% of titanium dioxide in waterborne coatings, the final results show, in great contrast to the pigment volume concentration in the range of , substituted kaolin 15% titanium dioxide, hiding power of coating system substantially unchanged; at the same dosage, kaolin has better hiding power than calcium carbonate.
3 Preparation of special functional coatings
Due to the porous diatomite, which has moisture absorption and desorption respiratory function and excellent adsorption properties of synthetic resin, and diatomaceous earth coating, the coating surface when the temperature is below the dew point, it can rapidly absorb large amounts of moisture or knot dew; and when above the dew point, can rapidly absorb moisture release, which can effectively prevent the wall and ceiling, etc. produce condensation, played the role of automatic air-conditioning, protect the goods.
Japan reported the successful use of diatomaceous earth developed several "green" building materials: First, high temperature combustion of porous diatomite powder, heating and drying, after classifying prepared interior wall paint, can effectively regulate indoor air humidity ; the second is a modified cement by mixing the molten processed diatomite, according to 0.3% to 0.5% of the ratio of water is added to the mixture made, smear it on the wall, including in particular the toilet wall on a clear deodorizing effect. Swedish Fren high-tech companies also use diatomaceous earth itself thousands of times the number of activated carbon ultrafine pores developed into a can absorb odor paint the walls, the diatomaceous earth was added stucco, painting on the wall, It has the effect of withdrawing foul.
In addition to the above effect, adding diatomaceous earth in the paint, the paint can also control the color brightness. Kunming, a research unit developed into a diatomaceous earth interior wall paint, which is characterized by non-reflecting wall, indoor light, soft, and interior color can change with temperature change.
4 to reduce the cost of paint
For puerile coatings industry, people have been looking for alternatives to paint part of the base and other fillers to achieve the objective of reducing the cost of paint. For example, current research interests include the water-soluble polyvinyl alcohol interior paint is seeking polyvinyl alcohol substitutes, and in order to reduce the amount of polyethylene in the paint. Experiments show that after adding bentonite in polyvinyl alcohol (PVA) as the main film was water-based paints, polyvinyl alcohol and greatly reduce the amount of calcium carbonate: polyvinyl alcohol in an amount ranging from 3.0 to 3.5 is reduced to 2.0 to 2.5; precipitated calcium carbonate in an amount ranging from 15.0 to 20.0 was reduced from 13.0 to 15.0, the film-forming properties of the coating film is almost no change, but also to avoid the presence of winter usually polyvinyl alcohol coating agglomeration, and alone, the cost of paint will drop 150 yuan / t.
Adding an appropriate amount in coatings modified calcium bentonite and found that the amount of coating binders reduced by 1/3 ~ 1/2, thus greatly reducing the cost of paint.
Adding a certain amount of kaolin in the coating replace the expensive titanium dioxide to increase the hiding power coatings can also reduce the cost of paint. In the polyvinyl alcohol (PVA) as the main film of the aqueous coating composition, since the polymerization kaolin and polyvinyl alcohol film strength can be increased, thus reducing the amount of polyvinyl alcohol, the coating reduces the cost of $ 400 per ton .
5 Conclusion and Outlook
With the development of real estate industry, global demand for architectural coatings is growing, people quality architectural coatings, functional requirements have become more sophisticated, high-performance, high-quality, cost-effective coatings increasingly popular. For instance, to improve the environmental protection requirements, the need to develop architectural coatings have anti-pollution and contamination control performance.
Non-metallic mineral material because of its unique nature in the crystal structure, physical and chemical properties, it has a large application in terms of architectural coatings to improve performance, such as on a substrate such as bentonite covering reactive material to make architectural coatings It has antibacterial properties and removal properties of organic pollutants and so on.
With the development of technology, bentonite, diatomite, kaolin, rectories, etc. These types of non-metallic mineral resources, the gradual deepening of the study, its use will continue to be to improve the development, which has a more architectural coatings will be modified in the broad application prospects.

Feedback to "Iota Silicone Oil (Anhui) Co., Ltd."