Nowadays, the concept of low-carbon environmental protection is deeply rooted in people's hearts, whether it is buying furniture, or doing decoration, it is on the basis of budget enough, how to environmental protection. Like environmentally friendly waterproof coatings, there are two types, one is water-soluble coatings (water-based coatings), and the other is solvent-based coatings. Today Xiaobian will tell you what are the differences between the two, let's take a look!

What is solvent-based paint

Solvent-based coatings are actually what we call solvent-based coatings, and solvent-based coatings are architectural coatings made of organic solvents as dispersing media. Although solvent-based coatings have the problems of environmental pollution, energy waste and high cost, solvent-based coatings still have a certain range of applications, and their own obvious advantages.

First of all, from the performance comparison, solvent-based coatings still have a great advantage. Coating solvents mainly include three categories of products, the first category is hydrocarbon solvents, according to different boiling points for classification; The second category, which is also the most widely used and the most mainstream category, is the oxygen-containing solvent; The third is the most unique solvent of all - water.

Advantages of solvent-based coatings

1, can dissolve and disperse the film forming material in the coating, form liquid coating, adjust the viscosity and rheology of the coating, suitable for the selected various coating methods. In the spraying process, the atomization performance of solvent coatings can be improved.

2, during the storage process, the solvent is conducive to increasing the storage stability of the paint and preventing the coating from caking.

3. Increase the wettability of the coating to the coated material and improve the adhesion.

4, can effectively give the film fluidity and leveling, to ensure that the paint leveling at the same time does not produce flow.

5, improve the mechanical properties and appearance of the film.

The difference between waterborne coatings and solvent-based coatings

First, the coating system is different

① Different resin. The resin of water-based coatings is water-soluble and can be dispersed (dissolved) in water, while the resin of solvent-based coatings is insoluble in water.

② Diluent (solvent) is different. Waterborne coatings can be diluted with deionized water in any proportion, and solvent-based coatings can only be diluted with organic solvents (odorless kerosene, light white oil, etc.).

Second, the paint construction requirements are different

① As far as the construction environment is concerned, the freezing point of water is 0 ° C, so the water-based coating can not be constructed below 5 ° C, but the solvent-based coating can be constructed above -5 ° C, but the drying speed will be slowed down, and the interval between roads will be elongated;

(2) In terms of construction viscosity, the viscosity reduction effect of water is poor, and water-based coatings will be more troublesome when adding dilution and viscosity reduction agents, solvent type is more convenient to adjust the viscosity, viscosity limits will also affect the choice of construction methods;

(3) For drying and curing, water-based paint is more "delicate", when the humidity is high and the temperature is low, the curing is not good and the drying time is prolonged. However, if the temperature rises and heats up, water-based coatings also need to be heated up in a gradient and immediately enter a high-temperature environment. After the surface of the water-based paint is dried, the internal water vapor overflow will produce pinholes, and even large areas of bubbling. This is because water-based coatings have only water as a diluent, and there is no volatilization gradient. In solvent-based coatings, the diluent is composed of organic solvents with different boiling points and has multiple volatilization gradients. Flash steaming (after the completion of construction to the drying period before entering the oven) after entering the high temperature area baking will not appear similar phenomenon.

Third, the difference in coating decoration after film formation

1, different gloss performance

① Solvent-based coating can control the fineness of the pigment filler according to the grinding situation, and it is not easy to coarsene when stored. Changes in film gloss can be achieved by adding resin to control coated PVC (face base ratio) and auxiliaries (such as matting agent). Gloss can be matt, matte, semi-matte, highlight. The gloss of automotive paint can reach more than 90%;

② The gloss performance of water-based coatings is not as wide as that of oil-based coatings, and the high gloss performance is poor. This is because the water in water-based coatings acts as a diluent. The volatile properties of water make it difficult for water-based coatings to show more than 85% high gloss.

2, color expression is different

A wide range of solvent-based coating fillers, whether inorganic or organic, so you can tune out a variety of colors, with excellent color performance;

② The selection range of fillers for water-based coatings is small, and most organic pigments cannot be used. Due to the incomplete tone, it is difficult to produce as rich a color as solvent-based coatings.

Fourth, the difference between storage and transportation

Water-based coatings do not contain flammable organic solvents and are therefore relatively safe to store and transport. If contaminated, it can also be washed and diluted with plenty of water. However, the storage and transportation of water-based coatings have temperature requirements, and the thermal insulation transportation and storage are required to be carried out at -5 ° C, otherwise there will be drawbacks such as breaking milk.

Five, functional differences

Solvent-based coatings are mostly organic. Organic products will have a series of problems such as chain breaking and carbonization at high temperatures. At present, the maximum temperature resistance of organic products does not exceed 400℃.

Waterborne coatings contain special inorganic resins, which can withstand the temperature of thousands of degrees, which is impossible to reach the height of solvent-based coatings.

6. Differences in safety and environmental protection

Solvent-based coatings have safety hazards of fire and explosion in the process of production, transportation, storage and use, especially in the construction of confined space, which is easy to cause suffocation and explosion. At the same time, organic solvents can also cause certain harm to the human body. The most famous case is the carcinogenic case of toluene, which is no longer allowed to be used. The VOC of solvent-based coatings is high, and the conventional products are even as high as more than 400, and the environmental protection and safety pressure of enterprises is greater when producing and using solvent-based coatings.

Water-based coatings are environmentally safe in production, transportation, storage and use (except for pseudo-water-based coatings produced by some informal manufacturers), and have made great contributions to energy conservation, emission reduction, safety and environmental protection in the corresponding national policies.

All in all, the two have advantages and disadvantages, because the performance of water-based coatings is not comprehensive, can not fully meet the needs of society, so solvent-based coatings are still necessary, we can analyze according to their own needs when choosing.

Article source: Lumbi waterproof, Qijia network, the United States BNK additives