Waterborne fluorocarbon coatings are widely used as durable decorative protective coatings for exterior walls, roofs and building materials of various buildings. Fluorocarbon coatings are widely used in the field of modern industrial anticorrosion, which can be divided into water-based and oil-based. Different types of products have different product characteristics and coating range. This article will introduce the differences between them.
The difference between water-based paint and oily paint can be said from the following angles:
A. Different coating systems
1. Different from resin, waterborne coating is a kind of protective coating with high weatherability, high film hardness and good stain resistance. Can be dispersed (dissolved) in water;
2. Different diluents (solvents). Water-based paints can be diluted with deionized water in any proportion, while oily paints can only be diluted with organic solvents (odorless kerosene, light white oil, etc. ).
3.VOC content is different. Waterborne coating is a kind of environmentally friendly and healthy coating. The VOC content is very low, which meets the environmental quality standards and will not affect people's health when used.
B. Different requirements for coating construction
1. For the construction environment, the freezing point of water is 0℃, so water-based paint can't be constructed below 5℃, and oily paint can be constructed above -5℃, but the drying speed will slow down and the road spacing will be lengthened;
2. For the construction viscosity, the viscosity reduction effect of water is poor, and the dilution of water-based paint will be relatively troublesome (viscosity reduction will greatly reduce the solid content of coating working fluid, affect the hiding power of coating and increase the number of construction times), the viscosity adjustment of oily paint is more convenient, and the viscosity limitation will also affect the choice of construction method;
3. For drying and curing, water-based paint is more delicate, curing is not good under the condition of high humidity and low temperature, and drying time is prolonged. However, if heated, water-based paint also needs gradient heating, which will instantly enter the high temperature environment. After the water-based paint is dried, the internal water vapor will overflow, resulting in pinholes and even large-scale bubbling. This is because only water is used as diluent in water-based paint, and there is no volatilization gradient. For oily paints, diluents are composed of organic solvents with different boiling points, and there are multiple volatilization gradients. After flash evaporation (the drying period from the completion of construction to before entering the furnace), similar phenomena will not appear when entering the high temperature area for baking.
C. Differences in decorative properties of coatings after film formation
C- 1。 Gloss is expressed differently.
1. Oily paint can control the fineness of pigments and fillers according to grinding, and it is not easy to coarsen when stored. By adding resin to control paint pvc (pigment base ratio) and additives (such as matting agent), the gloss of the coating film can be changed, which can be dull, matte, semi-dumb and high-gloss. The gloss of automobile paint surface can reach above 90%;
2. The gloss performance of water-based paint is not as wide as that of oily paint, and the high gloss performance is poor. This is because water in water-based paint is used as diluent, and the volatile nature of water makes it difficult for water-based paint to show a high gloss of more than 85%.
C2。 Different color expressive force
1. Oily coatings and fillers have a wide range of choices, both inorganic and organic, so they can be used in various colors with excellent color expression;
2. The selection range of water-based paints and fillers is small, and most organic pigments cannot be used. Due to the incomplete tone, it is difficult to bring out colors as rich as oil paints.
D. Storage and transportation
Waterborne paint does not contain flammable organic solvents, so it is relatively safe to store and transport. If there is pollution, it can also be washed and diluted with plenty of water. However, the storage and transportation of water-based paints have temperature requirements, and they need to be transported and stored at MINUS 5℃, otherwise there will be problems such as demulsification.
E. functional transcendence
Oily paints are mostly organic products, and organic products will have a series of problems such as chain breakage and carbonization at high temperature. At present, the highest temperature resistance of organic products does not exceed 400℃. Water-based paint is a special high-temperature resistant coating made of special inorganic resin, which can withstand thousands of degrees of high temperature. For example, Shanghai Hengfeng FC-W series waterborne fluorocarbon paint can resist high temperature for a long time, and the highest temperature is 3000℃, which is impossible for oily paint.
G. Differences between safety and environmental protection
There are hidden dangers of fire and explosion in the process of production, transportation, storage and use of oily coatings, especially in closed space construction, which is easy to cause suffocation and explosion. At the same time, organic solvents can also cause certain harm to human body. The most famous case is toluene carcinogenesis, which is now banned. The voc of oily paint is high, even higher than 400 for conventional products. When enterprises produce and use oily coatings, environmental protection and safety are under great pressure. Water-based paints are environmentally safe in the process of production, transportation, storage and use (except some pseudo-water-based paints from informal manufacturers), which has made great contributions to the corresponding national policies of energy conservation, emission reduction, safety and environmental protection.