What is the difference between epoxy paint and polyurethane paint?

The difference between epoxy paint and polyurethane paint is that they differ in composition and properties. Epoxy paint is composed of epoxy resin and curing agent, which has excellent corrosion resistance and wear resistance, and is suitable for coating substrates such as metal and concrete. Polyurethane paint, on the other hand, is composed of polyurethane resin and solvent, which has good weather resistance and chemical resistance, and is suitable for coating substrates such as wood and plastic.

In addition, polyurethane paint has good gloss and color stability.

Epoxy paint and polyurethane paint are products that customers have inquired about, and they are relatively widely used products.

Appearance of paint film: polyurethane paint: the paint film is plump, bright in color and good in decoration.

Epoxy paint: Although the color is diverse and adjustable, it is slightly less decorative than polyurethane paint compared to polyurethane paint.

Product performance: corrosion resistance: polyurethane paint has good acid resistance, epoxy paint has good alkali resistance, and the damp and heat resistance of epoxy paint is slightly better than that of polyurethane paint.

Design use: polyurethane paint: due to its plump paint film, adjustable color, good decoration and other properties, it is mostly used as a topcoat. However, polyurethane paint has poor weather resistance and is easy to yellow, and it is anti-corrosion coating for indoor steel structures and mechanical equipment.

Epoxy paint: Due to the poor weather resistance of epoxy paint and easy to pulverize, it is mostly used as a primer, such as indoor steel structure, mechanical equipment and other anti-corrosion coatings can also be used as topcoats. Epoxy primers are versatile and have excellent supporting properties.

Hello: polyester paint.

It is a thick paint made of polyester resin as the main film-forming material. The paint film of polyester paint is plump, and the layer is thick and the surface is hard. The same is true for polyester paint.

There are varnish varieties, called polyester varnish.

Polyester paints need to be cured during the construction process, and the amount of these curing agents accounts for one-third of the total paint weight. These curing agents are also known as hardeners, and their main ingredient is TDI (toluene diisocyanate). These free TDIs will turn yellow, which not only makes the furniture paint surface classic, but also makes the adjacent wall surface yellow, which is a major disadvantage of polyester paint.

At present, yellowing-resistant polyester paint has appeared on the market, but it can only be "yellow-resistant". It is not yet possible to completely prevent the canonization. In addition, free TDI beyond the standard can also cause harm to the human body.

Polyurethane paint. Polyurethane paint is polyurethane paint. It has a strong paint film, full luster, strong adhesion, water resistance, wear resistance, corrosion resistance, and is widely used in high-grade wood furniture, but also can be used on metal surfaces. Its disadvantages mainly include blistering in case of moisture, pulverization of paint film, etc.; with poly.

Like ester paint, there is also the problem of yellowing. The varnish variety of polyurethane paint is called polyurethane varnish.

I don't know if you're referring to just the field of furniture paint or wood paint or the classification in the coatings industry as a whole?

To understand this problem from the entire coating industry, polyester paint may be polyester amino paint, polyester isocyanate paint, polyester epoxy paint; Polyurethane paints may be polyester isocyanate paints, acrylic isocyanate paints, polyether isocyanates, epoxy isocyanate paints, one-component polyurethane paints and so on.

The polyester paint referred to in the home decoration paint is polyester isocyanate paint, which can also be called polyurethane paint, but polyurethane paint may be polyester isocyanate paint and acrylic isocyanate paint. Therefore, only in the field of home decoration paint, polyester paint is a kind of polyurethane paint.

1. The composition is different.

Epoxy paint is composed of epoxy resin, physique pigment and curing agent.

Polyurethane paint is polyurethane paint. It has a strong paint film, full gloss, strong adhesion, water resistance, wear resistance, and corrosion resistance.

2. The application is different.

Polyurethane lacquer is widely used in high-end wood furniture, but also on metal surfaces. Its shortcomings are mainly blistering in case of moisture, paint film powdering and other problems, and polyester paint, it also has the problem of yellowing. The varnish variety of polyurethane paint is called polyurethane varnish.

Epoxy paint is suitable for painting the inner wall of oil tanks, and can be widely used on the surface of various light metal and cement structures indoors and outdoors, and can be coated in railway bridges, high-voltage transmission towers, containers, offshore drilling and oil production equipment, various vehicle chassis, heavy machinery, ships, chemicals, equipment and pipelines, and gas engineering gas storage cabinets used in different environments.

3. The characteristics are different.

Polyester paint is characterized by the formation of non-cyclic and or annular hydrogen bonds between polymer molecules, which can be separated and absorb external energy (20 25kj per mole) under the action of external force. When the external force is removed, hydrogen bonds can be formed again. This reversible repetition of hydrogen bond cracking and re-formation gives the polyurethane paint film a high degree of mechanical wear resistance and toughness.

The outstanding advantages of cured epoxy resin are that it is chemically stable, alkali-resistant, air-resistant, and oil-resistant. This is because there are no ester bonds in the epoxy resin, and the aliphatic hydroxyl groups contained in it do not react with the alkali, and the paint cured product has a three-dimensional mesh structure. Therefore, epoxy resin coatings are often used as anticorrosive primers, oil baths and other inner walls.

However, the acid resistance of epoxy paints is generally poor.