Paints and varnishes are still one of the most popular means for decorating the internal and external surfaces of various structures. Moreover, the scope of these products is constantly expanding, which is confirmed by regularly updated protective properties of the compounds. There are special types of paints and varnishes to prevent corrosion of surfaces, increase fire resistance and biological resistance. Along with this, the decorative qualities of coatings are also developing, also causing the emergence of new segments in the construction chemistry market.
General structure of paint mixes
To obtain multifunctional, durable and aesthetically attractive coatings, technologists of paint and varnish mixtures develop complex formulations involving the use of several components. The basis of most mixtures is formed by a filler - a component that gives the mixture sufficient viscosity and optimal film thickness. Active components are responsible for the “working” qualities, which in many respects determine the signs of classification of different types of paints and varnishes. The composition of a typical mixture includes additives, solvents, pigment chemicals and a binder base. For example, additives act as a kind of modifiers of operational properties - they increase spreadability, provide dullness, form insulating films, etc.
Pigment elements are responsible for color, and solvents make it possible to achieve the desired consistency of the mixture without additional inclusions. As for the binder, this is one of the most critical components of the composition, which enters into activity after the material has dried. It is he who ultimately contributes to the formation of a hard, elastic or loose coating with certain technical and physical qualities.
Silicone Binder Compounds
The most extensive group of paints and varnishes, whose popularity is due to attractive performance. Polycondensation mixtures represent the main types of paints and varnishes based on silicone resins - about 40%. In particular, alkyd, epoxy, polyurethane and other coatings with a universal set of characteristics have gained distribution. Such materials are designed for use both indoors and outdoors - as facade paint. The susceptibility to modification and film-forming flexibility allow the use of silicone mixtures for highly specialized purposes. So, in addition to household needs, this type of paint is involved in the processing of devices and special equipment. Thanks to electrodeposition, the material can be applied on the surface of non-ferrous metals by the innovative electrophoresis method.
Bituminous formulations
Today, varnishes, paints, enamels and various oils with solvent effects are made from bitumen. Some manufacturers form entire lines of paints manufactured on natural resins. Bitumen itself may contain natural rosins, vegetable oils, white spirit and solvent. On the same basis, a group of amber varnishes is also used, which are used in the national economy. If we talk about operational properties, then almost all types of paints and varnishes from bitumen are characterized by a high degree of viscosity, effective insulating property and mechanical strength. In some areas of application, a special technique is applied for applying such materials - by deposition. Thanks to this laying method, a complete surface sealing with physical protection is ensured. Also, unlike roll and film coatings, heavy bitumen paints are less environmentally harmful.
Cellulose Ether Compositions
This product is obtained by mixing cellulose with solvents - alcohols and acids. It turns out solid film-forming materials, which, although not directly related to polymers, but in terms of performance, fit perfectly into the ideas about synthetic types of paints and varnishes and their characteristics like thermoplasticity, solubility in organic fillers and chemical resistance. However, there are also exceptions - for example, cellulose esters give the coating a low ability to withstand acids and alkalis, while simple ones withstand high temperatures without releasing free acids. In both groups, mixtures with dielectric properties can occur.
In practice, paints and enamels from cellulose ethers are used as modifiers that provide the effects of thickeners, stabilizers and plasticizers. In the form of an independent tool, these products are used as a coating material, a wellbore solution and a dye.
Industrial types of paints and varnishes
Due to economic constraints and established technical and physical qualities, special requirements are imposed for this category of products. Since large volumes of material are often used, technologists are tasked with optimizing the production process in order to obtain a high-quality, but also inexpensive product. In industrial types of paints and varnishes, the properties of chemical and physical protection come first, since engineering structures and structures operating in harsh conditions are usually treated with such coatings. For example, varnishes based on fatty acids and harpius ester are suitable for coating lithographed tin. Paints from rosin-glyphthalic resins are more often used as a means of durable marking of aluminum and magnesium alloys.
Amber varnish made from fused resin is also used in industry. The raw materials are initially modified with vegetable oils with the addition of desiccants, and later on, auxiliary additives may be added to the composition depending on the purpose. As a rule, amber varnish is used in the coating of canned tinplate.
Powder paints
These are multicomponent compositions of the dispersed group of paints and varnishes. The function of the film-forming substance in this case is performed by solid particles separated by air currents. Powder materials have one important requirement - they must be evenly distributed across the work site. As already noted, the dispersed medium for such types of coatings and materials is formed by the air itself, and not water with solvents. On the one hand, this gives economic and organizational advantages, since the painter gets rid of the hassle of preparing raw materials for diluting the components. On the other hand, the processing is carried out using a compressor unit and a spray gun. Spraying is performed, which also requires some organizational investments, but due to the effectiveness of the spray gun, the basic costs can be easily compensated.
Construction varnishes
The main difference between varnish and paints is its ability to form hard coatings after drying. An exception can be called bitumen insulating compounds, which form an airtight film and are not designed for protective mechanical functions. The role of a binder is usually performed by resins (artificial or natural), as well as vegetable oils. As solvents use special organic components or water. By the way, water-soluble types of paints and varnishes and their characteristics are optimally suited for individual use in everyday life - varnishes of this type are environmentally friendly, so they can be used openly in residential premises. Manufacturers themselves seek to orientate a particular recipe for specific tasks. So, there are special tools for varnishing facade surfaces, parquet floors, plastic parts, metal structures, etc.
Enamel coatings
In fact, these are oxidative paints or epoxy liquid coatings, which are distinguished by their insulating effect and resistance to abrasion. Due to their mechanical stability, enamel compositions are widely used in the treatment of floor surfaces. After hardening, the coating withstands cyclic and static loads, resists abrasive influences and does not lose aesthetic characteristics. Use enamel as a paintwork material and for facade design. Exterior decoration of walls, roofs and even parking areas with paths may well be carried out with the corresponding enamel compounds suitable for external use. For example, there are perchlorovinyl, furyl, and epoxy materials that provide a protective barrier against ultraviolet radiation, weathering, etc.
Primers
A special group of paints and varnishes that are not included in the segments of building putty mortars, but partly perform their functions. Mostly these are water-dispersed types of paints and varnishes, the main properties of which are to provide a leveling effect, insulation and increase adhesion. In general, these are preparatory mixtures that eliminate defects in the rough surface, on which it is planned to apply decorative paint in the future. Individual modifications of primers can perform the tasks of antiseptic treatment, biological and anticorrosive protection.
Intended classification
Since the range of tasks that paint and varnish materials perform is very wide, manufacturers use several markings to indicate the nature of use of a particular product. At a basic level, the following types and purposes of paints and varnishes can be distinguished:
- Weatherproof compounds. For exterior decoration of houses and structures. Also called facade paints.
- Limited weather resistant compounds. Designed for indoor use, as well as for use in sheltered places in the open air.
- Preservation products. Protective coatings, which are intended for temporary insulation of surfaces of machinery, equipment or building structures.
- Water resistant compounds. Tolerant materials to moisture, steam and direct contact with water. They can be used in rooms with a high coefficient of humidity.
- Specialized paints and varnishes. Materials that are suitable for special operating conditions - they can be distinguished by high chemical resistance, temperature protection, sound insulation and electrical conductivity.
Conclusion
A properly selected outer coating can not only ennoble the appearance of the surface, but also extend the life of the base material. Given the protective and decorative properties of different types of paints and varnishes, you can choose the best option for external processing for each case. But also do not ignore the secondary performance of coatings. These include environmental cleanliness, adhesive compatibility with the base material and maintenance requirements.