Nowadays, environmental protection requirements are increasing day by day, and water-based aluminum paste is the future development trend. Sunflower Chemical Group has also made major breakthroughs in the research and development of water-based aluminum paste.
Aqueous aluminum paste usually has three forms, namely scale-like, silver-dollar-like and irregular; sunflower chemical is silver-dollar-like (shape under the microscope).
The appearance is silver and paste-like, and the solid content is generally about 65%. The aluminum slurry is coated with silica and then heated and reacted in the reactor, and then the residual liquid is separated out by a centrifuge or a filter press.
Silica coating is a chemical coating method. The coating of silica and aluminum sheets is relatively close, the stability is good, and the coating is tight and uniform.
Relatively does not reduce the gloss of the surface of aluminum powder, and at the same time has good acid and alkali resistance.
1: The basic composition of water-based wood paint
(1) Polymer emulsion or dispersion. This is the base material for film formation. Determines the main properties of the paint film.
(2) Coalescence aids. After the water volatilizes, the emulsion or dispersion particles form a uniform and dense film, and the film-forming property at low temperature can be improved.
(3) Foam inhibitor and defoamer. And the bubbles generated in the paint liquid during the production process can make the generated bubbles escape from the liquid surface and break the bubbles.
(4) Leveling agent. Improve paint workability to form a smooth, glossy finish.
(5) Wetting agent. Improve the wetting performance of the paint liquid to the substrate, improve the leveling, and increase the adhesion of the paint film to the substrate.
(6) Dispersant. Promote the dispersion of pigments and fillers in the paint liquid.
(7) Rheological additives. Provides good fluidity and leveling to the paint, reducing the ills in the milking process.
(8) Thickener. It increases the viscosity of the paint liquid, increases the wet film thickness of one coating, and has the effect of preventing precipitation and delamination for imparting and solid color paint.
(9) Preservatives. Leave the paint solution mildewed during storage.
(10) ESSENTIALS. Gives the lacquer a pleasant smell.
(11) Colorants. Mainly for colored paints, making water-based paints have the desired color. Colorants include pigments and dyes. Pigments are used for solid paints (painting that does not reveal wood grains), and fuels are used for transparent paints (paintings that reveal wood grains).
(12) Packing. Mainly used in putty and solid paint to increase solid content and reduce cost.
(13) Ph regulators. Adjust the pH value of the paint liquid to make the paint liquid stable.
Two: Adjustment of water-based wood silver paint
(1) The resin and base material of the silver paint are also very important. Generally, acrylic resin can be used for low requirements, and polyurethane resin is used for high requirements. The former is the main component of water-based wood paint, which is mainly characterized by good adhesion and no deepening. The color of the wood, but the wear resistance and chemical resistance are poor, and the hardness of the paint film is soft. , The fullness is good, and the comprehensive performance is close to that of oil-based paint. What we want to talk about here is mainly wood paint made of polyurethane. Polyurethane is divided into one-component and two-component, mainly according to its own situation. Of course, there are also companies that use polyurethane and acrylic together. Good use will reflect the characteristics of both products, and poor use may be counterproductive. Why do high-end wood paints use polyurethane? As mentioned above, because of the good hardness of polyurethane, we all know that there are often bumps in the transportation of furniture. If the hardness is not good, you can imagine. The disadvantage is that when it is made into silver paint, the brightness of the aluminum paste itself will be blocked.
(2) After we know the above steps, we will have a general idea. The addition of aluminum paste to the paint is usually 10%-20%. Of course, there are special cases, which should be adjusted repeatedly according to their own formula. Explain the problem of adding amount. Aluminum paste is divided into leafing type and non-leafing type. Non-leafing aluminum paste is in the form of (/-/-), and leafing aluminum paste is (----). Therefore, the coverage area of non-leafing aluminum paste and leafing aluminum paste is higher than that of non-leafing type, that is to say, the same formula and ratio are used to calculate the addition amount of leafing type aluminum paste is less than that of non-leafing type. Leafing aluminum paste will also have a strong sense of metal due to its flat arrangement. The disadvantage is that it will drop powder if it is not handled properly.
(3) After adding various additives to the diluted polyurethane and stirring well, add 15% of the aluminum paste and stir with the resin, so that the aluminum paste is fully dispersed in the resin, and the speed needs to be lowered during stirring to avoid foaming. A common problem here may be that the aluminum paste does not disperse in the resin or foams. There are many reasons for the poor dispersion. For example, the aluminum paste itself is not well dispersed, or it conflicts with the resin system. It may also be that the improper use of additives will cause the phenomenon of inability to disperse or flocculate. The reason for the bubbles may be that the air enters the paint after stirring too fast, and let it sit for a while, if the bubbles disappear, it can be used normally. As for why aluminum paste foams in the paint, aluminum itself is active and will react with water to generate hydrogen, so we should do a test first when choosing aluminum paste. You can put the aluminum paste into a sealed bag and remember to release the gas. , put it in 50% warm water for two days, and observe whether the silver paste in the bag has flatulence or discoloration after two days. If there is flatulence or discoloration, it means that the quality of the aluminum paste is very general. Good aluminum paste processing must have temperature resistance. , acid and alkali resistance, not easy to be oxidized, strong sense of metal, etc.
(4) After the above steps are completed, first take a small sample, take a piece of wood that needs to be painted, and use a brush to brush a thin layer of paint on the wood. Polyurethane is generally self-drying, and it should be noted that it should be evenly painted when brushing. No matter how cramped and limited the space environment, it must be clean and free of dust, fly ash and clutter. The best state of the coating environment is room temperature, and the temperature is constant, the humidity is below 70%, and there is gentle ventilation. Under this condition, it can ensure the rapid evaporation of water, and reduce or eliminate the phenomenon of wood grain particles and long burrs. The coating environment temperature is lower than 15 ℃, or higher than 30 ℃ will affect the coating effect. The painting should be carried out in fine weather. Before spraying, the areas that do not need to be painted must be covered tightly, and one side of the paint mist will be contaminated. A soft brush should be used for brushing, which requires no shedding, softness, and strong water absorption. Before use, remove the hairs that are not fixed firmly, wash them with water, and dry them before use. It must be noted that the brush must be wetted with water before dipping the paint, but there must be no dripping water, otherwise the paint brush will quickly dry and solidify and scrap, or the paint in the paint brush will dry and slag, which will affect the painting effect. , After drying, brush the second pass to complete. Here you can simply test the hardness and adhesion by yourself. Take a roll of transparent glue and pull two on the painted wood to see if the glue sticks to the powder. The hardness can be scratched with your fingernails a few times. In fact, everyone The concern should be the issue of white brightness and hue. I should focus on this issue.
Oil-based paint has higher hardness and better plumpness, but it goes without saying that water-based paint is environmentally friendly. Friends who have used water-based aluminum paste must know that no matter how water-based paint is adjusted, it cannot achieve the oil-based effect, and the oil-based paint is shiny on wood. Oily, with a silver feel. After the water-based aluminum paste is made, the contrast is dead color and no metallic feeling. In fact, our company has been developing water-based aluminum paste for high-end woodware, and now we have made some breakthroughs. In fact, the main reason is that water-based products are still in China. It is immature, and some supporting things have not kept up, such as resin covering the metallic feel of aluminum paste, and some additives are difficult to find or use. What I am talking about here is for silver paint on high-end furniture. We can still solve ordinary silver paint.
developmental disorder
1. Price factor
The price of a single tank of ordinary water-based wood paint is higher than that of traditional paint, almost 2-5 times that of oil-based paint. The price of water-based paint has been high for a long time, making it difficult for consumers to accept it in a short time, so the market promotion speed is extremely slow;
2. Performance factors
Compared with traditional paints, water-based paints still lag behind in terms of fullness, hardness, wear resistance and hand feel of the paint film. Although the market share of water-based wood paints is expanding, its application in high-end furniture has been limited. limit;
3. Habit factor
As mentioned above, workers who are used to traditional paints are skeptical about water-based paints, have a mentality of rejection, and the immature construction technology hinders the promotion of water-based paints. Weak follow-up in the case of poor returns;
4. Brand factor
At present, the big brands of wood paint on the market are doing well in traditional paint, and they have stable channels and users. They are not willing to vigorously promote water-based wood paint. Without the echo of the big brands in the market, the promotion of water-based paint in the world is vigorous. not enough. The water-based paint is suppressed by the big brands of oil-based paint, and it still needs to accumulate stamina to get rid of the fetters and hit the market;
5. Policy Factors
Although the use of environmentally friendly and healthy coatings is advocated, there is no explicit prohibition on the production of solvent-based wood coatings, nor the use of water-based wood coatings, which also leaves room for oil-based paints to survive for a long time.