The coating industry will focus on the development of four types of coatings in the future

At present, the primary task of the coatings industry is to develop four types of environmentally friendly coatings.
Secondly, it will take time to achieve this goal.
Solvent-based coatings still occupy a considerable proportion of the transitional stage.
It is also important to replace toxic solvents with efficient and non-toxic solvents.
An important current work
.
Starting from the concept of sustainable development, the development of renewable organic solvent resources is the third task facing paint workers
.

The four types of environmentally friendly coatings that the coatings industry will focus on in the future include:
high-solids coatings and

high-solids solvent-based coatings (HSSC), also known as VOC solvent-based coatings
.
The volume (NVV) solid content of traditional solvent-based thermosetting coatings is usually about 25-35%, and some thermoplastic coatings will be lower
.


There is no unified statement about the definition of high-solid coatings.
There is a formulation in China that high-solid coatings refer to coatings with a solid content greater than or equal to 70% during spraying
.
Some international formulations are that for automotive flash metallic paint (or topcoat base paint), its high solids refers to about 45NVV; for high-pigment primers, its high solids may be 50NVV
.
This requires that the molecular weight of the synthetic resin used in the coating and the average functionality of each molecule must be reduced, and the molecular weight distribution must be narrowed
.
In this case, it is difficult to maintain the function of the coating film at the same time
.
Therefore, research and development of new crosslinkable resin synthesis technology and strict control of the curing conditions of the coating film have become the key to the problem
.
At the same time, the realization of such coatings only reduces the amount of organic solvents
.

Solvent

-free paint The so-called solvent -free paint is the use of an organic solvent called a reactive solvent or reactive diluent in the paint
.
It can not only dissolve or disperse the film-forming substance, but also chemically react with the film-forming substance during the film-forming process of the coating film, forming a non-volatile component and staying in the coating film
.
Since the organic solvent does not overflow during the coating and film forming process, the pollution to the environment and the toxicity to the human body are reduced
.


The solvent-free products currently used mainly include two-component (two-component) epoxy-based solvent-free coatings and acrylic-based light-curing coatings
.
The development direction of solvent-free coatings is to expand the variety, increase the adaptability to coating methods and develop thin coating products
.

Water-based paint is a

colorless, transparent, non-toxic and odorless liquid with abundant resources
.
The use of water instead of organic solvents as the dispersion medium of the coating resin will undoubtedly completely avoid the above-mentioned three hazards caused by the use of organic solvents
.
Therefore, it has become an important product of the developing environment-friendly coatings
.


Water-based coatings can be divided into latex coatings (Latexcoatings) and water-reducible coatings (water-reducible) two categories
.
At present, the mature latex coating products are mainly architectural latex paints, and the water-thinning coatings are mainly industrial water-based electrophoretic primers
.
The reporter learned that with the Chinese government GB18581-2001 "Interior Decoration Materials: Limits of Hazardous Substances in Solvent-based Wood Coatings" and GB18582-2001 "Interior Decoration Materials: Limits of Hazardous Substances in Interior Wall Coatings" and other national standards promulgated, water-based wood coatings have also been issued.
Began to apply, and the technology matures day by day
.


However, water-based industrial coatings are affected by the need to improve the performance of water-based coatings compared with the corresponding solvent-based coatings, the relatively high cost, and the specific requirements for the coating environment.
Therefore, it is still necessary to expand the scope of products and applications.
Work
.

Powder coating (powder coating)

theoretically does not contain any volatile substances, it is an absolute zero VOC coating, and one of the most important products for the development of environmentally friendly coating products.

.
However, powder coatings are subject to certain restrictions in expanding their applications, and further improvements are needed
.
For example, its manufacturing cost is relatively high; it needs to be baked at high temperature to form a film; it is difficult to obtain a thin film coating
.
Since the toner coatings paints difficult process determined; poor in the uniform coating of an irregular surface of an object
.
These all need further research and development
.


Based on the above, the development of the above four types of environmentally friendly coatings is not only the unswerving work direction of Chinese paint workers, but also should be aware that it will take time to achieve this goal
.