Research progress of water-based auto parts coatings

Author of this article: Shu Shujun

Source of this article: Issue 4 of "Coating Industry" in 2021

Auto parts refer to all parts and components that make up a car.

1.

An ordinary passenger car is composed of about 10,000 parts and components, which are various and complex.

Figure 1 shows the results of classifying and counting the number of auto parts according to the types of materials used

Figure 1 Summary of auto parts according to the proportion of base materials used

It can be seen from Figure 1 that in the classification of auto parts, metal parts account for a relatively large number of parts, more than half of the share, followed by plastics (such as electronic appliances) and accessories

Table 1 Classification of substrates for auto parts and types of coatings used

2.

In the "Thirteenth Five-Year Plan", the government encourages the environmental protection of automotive coatings and component coatings

According to relevant data, from 2014 to 2018, with the increase in car sales, the sales of auto parts coatings increased accordingly.

Figure 2 Market share of China's automotive metal parts coatings segment in 2018

The amount of coatings used for axles and wheels ranks the top two, and the total proportion of the two coatings is more than 60%.

Aiming at the current vigorous trend and progress of water-based coatings for auto parts, this article summarizes the traditional coating systems and water-based coating systems of some important auto parts on the market, as shown in Table 2

Table 2 Coating Coating System for Auto Parts

It can be seen from Table 2 that most of the auto parts already have related supporting water-based coating solutions, some have been mature applications, and some performances are still being continuously improved and perfected

3.

Aiming at different water-based coating solutions for auto parts, this article shares two more characteristic water-based coating solutions

3.
1 Auto parts protection solution-water-based acrylic epoxy hybrid system bottom surface all-in-one coating

Diesel engine coatings are generally a matching form of solvent-based epoxy primer and polyurethane topcoat.
Due to the complexity of construction, and the polyurethane topcoat is easy to foam, and the bottom surface is combined with a water-based acrylic epoxy hybrid system to form a film of 60~80μm at a time , The coating film has good salt spray resistance, hardness and weather resistance, and meets the coating performance requirements of diesel engines.
It has been successfully applied to diesel engines; while meeting performance requirements, the coating film can reduce the complexity of construction.
It can also reduce costs and reduce VOC emissions, an economical and environmentally friendly water-based solution
.

3.
2 Temporary protection solutions for auto parts-water-based peelable coatings

In the production, transportation and handling of auto parts after coating, the coating film is easily affected by bumps, scratches, dust, dirt, fingerprints, etc.
In order to avoid such effects, the temporary protection of water-based peelable coatings provides effective The solution has a wide range of applications
.
A water-based solution that provides temporary protection based on water-based peelable emulsions can be used for temporary protection applications of auto parts, such as the protection or color change of wheels, the protection of car bumper coatings, the protection of car door coatings, auto 4S shop paint room wall protection
.
After the protection is over, it can be easily peeled off to solve the worries of customers
.

4.
Conclusion

The environmental protection trend of auto parts coatings is becoming more and more obvious, and the environmental protection coating represented by water-based coatings is one of the directions of future development
.
From the current point of view, the water-based automotive parts coatings have a long way to go, and there are still many problems that require close cooperation between raw material companies and coating companies to develop water-based solutions with better environmental protection, better performance, and better cost performance.
Promote the water-based process of auto parts
.