As an important part of the chemical industry, paint plays a major role in daily production and application. In 1915, Shanghai Kailin Paint Factory was founded, which kicked off the development of my country's paint industry. After a century of twists and turns, our country has gradually become the world's largest paint producer, and its annual output has accounted for more than 20% of the world's total output.
The overall development goal of the "14th Five-Year Plan" points out that during the "14th Five-Year Plan", the total economic volume of our country's paint industry should maintain steady growth, with an average annual growth rate of about 4% in total output value. By 2025, the total output of the paint industry is expected to grow to about 30 million tons.
It can be seen that our country's paint industry still has a large room for development, and paint involves many industries, so it has always maintained a huge demand scale. So, let us go deeper into the paint industry in this issue to understand its production and application.
Introduction to paint
Paint is a kind of material with a wide range of applications. Because most of them used vegetable oil as the main raw material in the early days, it is also called paint, but at present, the vegetable oil in paint has been basically replaced by synthetic resin.
Only when the coating is applied to the surface of an object and forms a continuous coating film can it show its function, which is generally anti-corrosion, anti-mildew, decoration, insulation and marking.
Composition materials
Coatings are generally composed of film-forming substances (resins), pigments, fillers, solvents and additives.
Film-forming substances (resins):
Film-forming substances (resins) are the basis of coatings. They have the function of bonding other components in coatings to form coating films, and play a decisive role in the performance of coatings and coating films.
There are two main types of film-forming substances, namely conversion film-forming substances and non-conversion film-forming substances. The difference between the two is mainly reflected in the molecular structure. Non-conversion film-forming substances are also called thermoplastic resins, that is, the spatial structure of resin molecules is linear or T-shaped; conversion film-forming substances are also called thermosetting resins, that is, the spatial structure of resin molecules is a network.
Pigments and fillers:
Pigments and fillers are mainly used for coating film coloring and improving coating film performance, enhancing the protection, decoration and anti-rust effect of coating films, but some pigments and fillers can provide coating films with specific functions such as anti-flammability, conductivity and anti-camouflage. According to the role they play in the paint, they can be divided into coloring pigments, anti-rust pigments, and body pigments.
Solvents:
The solvents involved in the production of paint are mainly volatile organic solvents or water, which can disperse the film-forming substances and pigments to form a viscous liquid and improve certain properties of the coating. However, the solvent itself does not constitute a coating and should not remain in the coating.
Additives:
Additives cannot form a coating alone. Their role is to exist in the coating as a component after the coating is formed. According to the different effects produced in different links in the production of paint, additives can be divided into four types, namely additives that act on the coating production process; additives that act on the coating storage process; additives that act on the coating construction film-forming process; additives that act on the coating performance.
Classification and application
There are many ways to classify coatings, including classification by purpose, state, film-forming substance (resin), usage, coating application, pigments and fillers, etc.
But generally speaking, the main classification method of coatings is mainly based on purpose and supplemented by the main film-forming substance. According to the purpose, it can be divided into three categories: architectural coatings, industrial coatings, and general coatings (including auxiliary materials), covering sub-sectors such as construction, ships, automobiles, and furniture; according to the main film-forming substances, it can be divided into epoxy coatings, polyurethane coatings, acrylic coatings, alkyd coatings, nitro coatings and other categories.
