What Is a Lacquer?
Lacquers are important paints widely used in industry and everyday life.
It refers to paint made by dissolving a synthetic resin such as acrylic in a volatile solvent called toluene or acetone. Originally, lacquers were made by dissolving nitrocellulose in an organic solvent.
Today, however, it is used as a generic term for quick-drying paints that use volatile solvents. Because it dries very quickly and is easy to handle, it is commonly used in spray cans.
Uses of Lacquers
1. Protection and Decoration of Wood
Lacquers are applied to wood surfaces to improve durability and provide a beautiful finish. They are used on furniture, flooring, and building materials to effectively protect wood and enhance its decorative qualities.
2. Rustproofing and Maintaining the Aesthetic Appearance of Metals
Lacquers, when applied to metal surfaces, serve to prevent oxidation and rusting. They are also used to paint automobiles and bicycles and to decorate metal products because of their beautiful luster and color.
3. Protection and Modification of Plastics
Lacquers also provide a protective layer for plastic products, preventing fading and deterioration. They are also used to modify the surface of plastics to add specific properties.
4. Imparting Color and Design
Lacquers are used for design and artistic purposes because of their versatile colors and sheen. They are applied to furniture, crafts, and artwork to achieve a unique appearance.
5. Aircraft and Ship Painting
Aircraft and ship exteriors require durability and resistance to weather conditions. Lacquers are used as paints that meet these requirements and continue to protect the appearance of ships and aircraft.
6. Industrial Product Finishing
Lacquers are also used in the finishing process of industrial products to ensure their appearance and durability. They are applied to metal parts and machine surfaces to enhance the quality of the product.
7. Improved High-Temperature Resistance
Some lacquer types have high-temperature resistance and are applied to parts and structures that are used in environments subject to heat. This improves safety and durability.
8. Arts and Crafts
Lacquers are also used to finish traditional crafts and artwork. They are applied to works of art and sculptures to beautify and protect them.
Principle of Lacquers
When lacquers are applied in a liquid state, their main component, the solvent, evaporates in the atmosphere. The evaporation of the solvent causes the paint to dry rapidly and change to a solid form.
As the solvent evaporates, the solid components in the paint gradually begin to migrate to the surface. This creates a thin film of paint, and the thickness and uniformity of the film are adjusted according to the properties of the paint.
The film formed on the surface undergoes chemical reactions such as oxidation and polymerization upon reaction with oxygen. This causes the paint film to solidify, forming a uniform, hard film. The properties of the film formed by chemical reactions are determined by the paint’s composition and additives. The properties of the film, such as hardness, gloss, weather resistance, and chemical resistance, vary depending on the type of Lacquers and the application.
Lacquer films also adhere to the substrate surface and are characterized by chemical or physical adhesion. In this way, Lacquers protect the surface of the substrate to which they are applied and provide resistance to external forces.
Types of Lacquers
1. Nitrocellulose Lacquers
Nitrocellulose lacquers are paints based on nitrocellulose. They dry quickly and provide uniform gloss and protection to wood and metal surfaces. Often used on musical instruments and furniture, they form a thin film and provide a beautiful finish.
2. Acrylic Lacquer
Acrylic lacquers are paints based on acrylic resin. They are characterized by high weather resistance and resistance to discoloration of the paint film. They are used for car exteriors, plastic products, furniture, etc., and provide durability and a beautiful finish.
3. Urethane Lacquers
Urethane lacquers are paints that use urethane resin as their main ingredient. They have excellent abrasion and chemical resistance and are widely used on wood, metals, and plastics. They are used for furniture, flooring, automobile interiors, etc., and provide long-term protection by forming a hard film.
4. Enamel Lacquer
Enamel lacquers are paints that combine hard resins and pigments. They are highly durable and are used on metals, ceramics, glass, and other materials. Widely used in models, industrial products, and decorative items, they provide a beautiful finish and protection.
5. Shellac
Shellac is a natural lacquer composed mainly of insect secretions. It serves to protect wood and furniture surfaces, adding luster and depth. It is used for food and pharmaceutical coatings and for finishing musical instruments.