Paint is one of the most essential materials for renovation. It is painted on walls, ceilings, window frames, doors and even concrete coverings. Apply paint both indoors and on the facade. Today the market of paints and varnishes is one of the most extensive and diverse.
The secret of the durability of any paint lies in the components that were used in its manufacture. But not all paint manufacturers are ready to open their chemical formulas to consumers. Marketers, who often confuse terms and concepts for the sake of quick product implementation, also bring confusion to the ranks of buyers. Most paints and varnishes, which include not only varnishes and paints, but enamels, primers, putties, are made according to a single component scheme. They must contain: a binder base, that is, the material that leads to the formation of a film on the surface, a pigment that gives the material its original color, a filler that saves pigment and gives the product physical properties, such as strength, gloss, application properties, special additives – fire-resistant antifoam, fungicidal substances that protect the material from mold and mildew and solvent. The paint of a reputable manufacturer will contain from 8 to 16 components. The level of the product itself directly depends on how well the components are selected and mixed. It should be noted that good components are quite expensive for manufacturers, so they have to keep quite high prices. However, it would be incorrect to judge the quality of paint by its price. It is not uncommon for manufacturers to offer the buyer paints at inflated prices, relying on the exceptional quality of products. But the chemical composition and, as a result, the quality of the paint is not so “exceptional”.
All building paints have their own precisely defined formula, on which their properties depend. Therefore, in order to apply the paint correctly and strictly for its intended purpose, it is necessary to know its composition and understand how the components included in it affect the properties of the resulting coating. Paints and varnishes consist of a number of components, which are divided into four groups: film formers, pigments, fillers, solvents and additives.
Let’s start in order. The value of the film former is to bind all components of the paint and adhere it to the substrate. The main characteristics of the paint, its resistance and adhesion to the substrate depend, first of all, on the film former, or, more simply, on the binder. Most often used as a binder: oil, drying oil, emulsions or latexes. The binder influences the durability, the service life of the coating under different operating conditions, the gloss and drying time, as well as the paint properties. According to the chemical nature of binders, all paints are divided into four main types: oil, alkyd, epoxy, latex (acrylic, vinyl). The use of a high quality binder is essential. It is on him that the quality, manufacturability and environmental friendliness of the paint depend, and ultimately the appearance and quality of the finished coating. Immediately, we note that when choosing a paint, it is incorrect to compare materials made on the basis of different binders..
Pigments are fine-grained dyes that are “responsible” for the hiding power and color of the paint. Colored fillers are usually: flock particles, chips, natural and tinted stone chips or quartz sand, water-insoluble pigmented particles with colored dyes. Colored pigments are traditionally divided into organic and inorganic. Inorganic, as a rule, have a high hiding power, however, their coloring power is inferior to organic pigments.
Now let’s look at what solvents are. Conventionally, solvents can be divided into solvents and diluents. What is the fundamental difference? The solvent dissolves the binder and at the same time lowers the viscosity, i.e. the flowability of the paint. The thinner only lowers the viscosity. The manufacturer is obliged to indicate the solvent suitable for this type of paint in the technical description of the composition. Paints and varnishes are classified not only by the type of binder, but also by the solvent used. On this basis, paints are divided into two classes: water-dispersible and organic-soluble. In water-borne dispersion paints, small amounts of slowly evaporating solvents are used. Solvents soften the binder particles, promote their setting and the formation of a continuous film on the surface.
Various additives are used to improve the technological and operational characteristics of paints. These additives (stabilizers, emulsifiers, antiseptics, fungicidal additives, etc.) are contained in paints in very small quantities, but they can decisively improve certain properties of the coating. In addition, their cost significantly affects the price of the final product..
WHAT SHOULD BE PAINT?
Regardless of the composition of the paint, a number of general requirements are imposed on modern decorative coatings: they must be environmentally friendly, easy to apply, easy to dry or wet clean. In addition, many types of coatings have special requirements, such as increased wear resistance in rooms with high traffic, moisture resistance when used in bathrooms, kitchens, etc..
When choosing paint and varnish or decorative coatings for the consumer, the decorative properties of the coating (structure, color, degree of gloss) are most important; and operational properties of the coating, as well as the cost of one square meter of coating.
Decorative properties of the coating
Modern paints and varnishes can have thousands of all kinds of shades that can be obtained within a few minutes using special tinting machines. According to the degree of hiding power, the paints lie in a wide range – from glazing (transparent) to opaque. According to the degree of gloss, paints are also divided into high-gloss, glossy, etc. – to matte and deep matt. Currently, the most popular are matte finishes. However, it should be borne in mind that the performance properties of coatings (resistance to washing and abrasion, ease of cleaning, the possibility of using detergents, etc.) are higher for glossy paints. The surface of the decorative coating can be either smooth or have a certain texture. The texture can be obtained both due to the properties of the material itself, and with the help of special tools and application technologies. It is also possible to obtain various optical effects – color change, depending on the illumination and angle of view, the creation of fluorescent coatings.
Performance properties of the coating
The operational properties of coatings include: resistance to washing and abrasion, color fastness, chemical and biological resistance (resistance to fungal growth).
Finnish standards, for example, classify interior paints into the following four classes, according to the requirements for the painted surface and the operating conditions of the coatings:
To grade 1 refers to surfaces in dry rooms that are subject to slight external influences and the requirements for a decorative appearance are low. These are, for example, walls in dry basements and archive rooms. The most important requirement for a paint is good hiding power. Often, coatings made from such paints are completely matte..
2nd grade covers surfaces in dry rooms and areas with normal room conditions and moderate requirements for the appearance of coatings, such as walls in bedrooms and living rooms. The main requirements are for the hiding power of paints and the resistance of coatings to washing. The surface must withstand mechanical wear and wet cleaning.
To grade 3 refers to surfaces in dry and damp rooms that are exposed to intense external influences and to which strict operational requirements are imposed. These are, for example, walls and ceilings in kitchens, toilets, stairwells and public areas. Paints of this class can also be used for repair painting. The painted surface must be waterproof and withstand heavy mechanical stress..
4th grade – these are areas that are particularly stressed and the requirements for which are particularly stringent, for example, washrooms, public and industrial kitchens, baths and staircases subject to increased wear and tear. Coatings in this class must withstand particularly strong mechanical stress, water and chemicals, and, in addition, must resist the formation of mold..
Resistance to washing and abrasion is characterized by the number of strokes with a brush of a certain hardness in a wet or dry state before the paint layer is broken. This indicator is decisive when choosing a paint for specific operating conditions. As mentioned above, glossy paints are washable. However, it should be remembered that a glossy film emphasizes all the unevenness of the base. When choosing a matte finish, it is necessary to correctly assess the operational loads in order to select a coating with the required durability (matte coatings can be either washable or not).
Obviously, paints used in damp and humid rooms must have increased biological resistance (for this, special additives are introduced into the composition of paints). Chemically resistant paints are recommended for use in hospitals, industrial premises, laboratories and washing shops where surfaces are exposed to splashes of chemicals and where disinfectants are used.
Colorful coatings can have various special properties, according to the purpose of the room where they will be used. The following coatings are produced: heat-resistant and temperature-regulating, electrical insulating, resistant to X-ray radiation, as well as coatings, which were already mentioned above, resistant to chemicals, with bactericidal properties, and others..
The technological properties of paints and varnishes are extremely important for the performers. These properties include: hiding power, drying time, adhesion, ease of application, thixotropy of the paint composition, etc. Opacity determines the number of coats of paint required to cover a contrasting (black and white) substrate. There are materials that allow you to cover a contrasting substrate in 1 layer. They are distinguished by a higher price, but lower consumption. To cover a contrasting picture with cheap vein coverings, much more is required. Usually good quality materials should be applied in two coats.
When buying paint, you should remember that it is not a liter of paint that is purchased, but the area painted with this liter. Moreover, when comparing paints, it should be about liters, not kilograms, since paints of the latest generations weigh less than their old counterparts. Thus, very often it turns out that a more expensive and high-quality paint is more profitable than a cheap one with a low covering ability..
One of the most important technological parameters that determine the speed of work is the drying time. Usually this parameter is written on the packaging. However, it is indicated for very specific (normalized) conditions, and the actual drying time is influenced by many factors, such as the temperature of the air and the substrate, the humidity in the room, etc..
High adhesion (adhesion of paint to the substrate) is a prerequisite for the formation of a high quality paintwork. Proper preparation of the substrate and adherence to the application technology is of great importance for improving adhesion..
In order for the paint and varnish material to be well applied to the surface, it must have a certain consistency, determined by the viscosity parameter. Too viscous material will be difficult to apply. Otherwise, smudges are possible, especially on vertical surfaces. Viscosity is of particular importance when coating with a spray gun.
To make the material convenient to apply, but at the same time to avoid smudges, special thixotropic additives are introduced into the paints. Thixotropy of a paint is its property to increase its fluidity when mixed. Thixotropic paint, when applied with a roller or brush, does not flow or drip from the tool, but at the same time it spreads well over the surface to be painted, forming an even film.
Finally, sustainability means harmlessness to health and the environment. When working with paints and varnishes, it is necessary to apply the precautions indicated on the packaging.
COLORING WITH THE EYES OF THE BUYER
Today, water dispersion paints are winning the consumer’s love. They appeared relatively recently. If the history of oil paints goes back several centuries, then water dispersion paints have existed for not much more than half a century. At least in our country, they began to be used only at the end of the 50s of this century. Their composition is a suspension of polymers in water, combined with a dye. First of all, it should be noted the ease of use of this material. These paints do not need a solvent, they are diluted with ordinary water. Paint splattered hands and tools can be cleaned quickly and easily with water. The paint has an aesthetic appearance, it can be tinted, that is, give it the desired color. In addition, the chemical structure of some of this material is such that it allows the painted surface to “breathe”. This has a positive effect on the indoor microclimate. However, like any other material, it has its drawbacks. Its surface gets dirty a little faster than that of alkyd enamels. But for paints with high moisture resistance, this is not a problem – they can be washed. Another advantage of water-based paint is its drying speed: from 30 to 60 minutes before tack (when the dust does not stick to the surface) and about 12 hours until ready.
But because of the insufficient durability of “water emulsion” floors, for example, you cannot paint with such paints. Another disadvantage is that manufacturers mainly produce white water-based paints. To solve the color problem, you can use special pigment concentrates of the desired shade and intensity..
The richest range of colors and shades and higher than that of water-dispersion paint, resistance to aggressive environments attract the consumer less environmentally friendly, but more familiar alkyd enamels. Forming a sufficiently strong film after drying, they are easy to clean when dirty. The undoubted, albeit subjective, advantage of this type of paint is that it can be both glossy and matte in terms of the degree of gloss. The disadvantages of this material include low parapermeability, the presence of odor (until it dries up) and a longer drying time – about 3 hours before tack and about a day until ready for use..
The enamel contains as a binder alkyd varnish – either pentaphthalic or glyphtalic, – a solvent (white spirit), desiccants (drying accelerator) and pigments.
The main indicators of the material are hiding power, that is, paint consumption per square meter of surface, and working viscosity. The latter affects the color quality. For example, if the paint is liquid, then smudges remain on the surface, if it is thick, there are brush marks. Therefore, thick enamel is diluted with a solvent. However, it must be borne in mind that the tone of the paint will change. To avoid this, two layers are applied: the first with diluted paint, the second with ordinary paint. Alkyd enamels can be painted on almost any material, having previously prepared the surface with a primer and putty.
Despite the low price, oil paints are significantly inferior to both alkyd enamels in terms of film hardness, aesthetics and color purity, and water dispersion paints in terms of water resistance and abrasion resistance, moreover, they dry longer. The structure of this material is similar to the structure of alkyd paints, only drying oil is used as a binder in oil paints. It is made on the basis of natural oils (for example, sunflower). The quality of the paint itself largely depends on the quality of the drying oil. However, drying oil that is not resistant to ultraviolet light cannot be a durable binder, sooner or later the sun’s rays will “destroy” the coating.
The binder of oil paint is oil, which dries out during the oxidation process. It can be linseed oil, linseed oil varnish, oil-saturated alkyd resin, or a mixture of various oils. Linseed oil is a low molecular weight binder that perfectly penetrates wood, forming a dense waterproof film. Linseed oil paints have a high solids content. This is due to the fact that linseed oil does not need solvents as a binder and, therefore, contains a minimum amount of volatile compounds..
The advantage of oil materials is a high degree of filling and low consumption. They are excellent as primers, e.g. for treating boards before painting.
According to GOSTs, oil paints of the following brands are produced (depending on the type of film-forming substance):
MA-021 – on natural drying oil;
MA-025 – on the combined drying oil;
GF-023 – on glyphtal oil;
PF-024 – on pentaphthalic varnish.
In cases where oil paints contain only one coloring pigment in their composition, the words “paint” are replaced by the name of the dye, for example, “ocher”, “red lead”, etc. To designate a number of materials between the abbreviation of the film-forming base and the code that determines the purpose and conditions of use additional indices are used:
B – no volatile solution
IN – for water-diluting
VD – for water-dispersed (water-based)
OD – for organodispersed
P – for powder
For oil paints, instead of a serial number, a number is put, indicating which drying oil it is made of:
1 – natural
2 – “Oksol”
3 – glyphthalic
4 – pentaphthalic
five – combined
Ready-to-use paints are sold packaged in containers of 0.5-3 liters. The labels indicate the purpose of the paint, color, consumption per 1 sq. surfaces with one-layer and two-layer coating, used thinners and other characteristics. These guidelines should be strictly followed..
Before proceeding with the description of some types of oil paint, we note that this paint and varnish material is subject to a rather strict classification according to the standards of GOST. Therefore, oil paints do not have individual names. Depending on the scope of their application, they are designated by the abbreviation of the letters and numbers that we talked about above. The choice of oil paint is usually done as follows. First, the purpose of the paint is determined, then they make a choice in favor of one or another manufacturer, taking into account, of course, the price factor.
HOW TO DECODE THE ENAMEL?
The binder for alkyd materials is an alkyd resin. Alkyd resins are mainly made by cooking vegetable oils – linseed, tall oil, soybean, and others – together with alcoholic and organic acids or acid anhydrides. Like oils, alkyd resins dry out by oxidation. The higher the fat content (oil percentage) of the alkyd resin, the more elastic the paintwork. The drying speed of alkyd resins is regulated by special additives – desiccants.
The selection of the type of oil can influence the drying time, color and gloss of the alkyd varnish. As a rule, paints and varnishes on alkyd varnish are characterized by ease of application and higher weather resistance compared to oil paints. Alkyd materials dry faster, do not shrink when dry, do not turn yellow and, unlike oil paints, practically do not chalk.
Alkyd paints traditionally protect all kinds of surfaces from wear and tear both inside and outside the building (doors, window frames, furniture, radiators, etc.). Alkyd paints can withstand wet cleaning with conventional detergents. They are used to paint walls and ceilings in kitchens and bathrooms. If you want to get a glossy finish, these paints are also chosen..
But still, paints based on organic solvents are used quite rarely in the interior. This is due to the fact that, although low-toxic white spirit is used as a solvent in modern solvent-borne paints, they are all inferior to water-based paints in terms of environmental friendliness. By tradition, they are also used because of their low price, especially as an enamel for metal. The use of alkyd paints in the interior is justified when it is necessary to obtain bright, saturated colors. They often paint the walls in kitchens, bathrooms and other rooms with high humidity..
It is quite simple to understand the products of Russian (including the CIS countries) manufacturers. The fact is that enamels are strictly classified according to GOSTs. Each gets a specific name in the form of a cipher, for example, “Enamel PF-120 white matt”. The first word directly indicates the type of material and no special decoding is required here (varnish, enamel, primer, etc.). The next two sometimes three capital letters are the abbreviation of the film-forming agent used as the base. In our case, PF means “pentaphthalic”. GOST defines about 40 names of various film-formers, consider the most “popular”.
General purpose enamel GF-230 (glyphthalic) intended for interior work, except for painting floors. Before use, it is diluted to a paint consistency with white spirit, turpentine or their mixture. It is produced in 21 colors: ivory, cream, lemon, etc. Opacity depends on the color and ranges from 30 to 130 g / m2. Apply by brush, roller or spray gun. Drying time – 24 hours. Shelf life – 12 months from the date of manufacture.
Enamel PF-133 (pentaphthalic) It is used for painting pre-primed or metal surfaces in 2 layers. In temperate climates, it retains its protective properties for at least five years. Before use, it is diluted to a paint consistency with solvent, xylene or a mixture of one of them with solvent gasoline. Produced in 15 colors: cream, green, blue, etc. It is applied with a brush or spray gun. Coverage depends on the color and ranges from 20 to 120 g / m2. Drying time – 2 hours.
Enamel PF-115 used for painting metal, wood and other materials that are exposed to weathering. It is applied in 2 layers. Retains protective properties in temperate climates for at least five years. Before use, it is diluted to a paint consistency with white spirit, turpentine or their mixture in a 1: 1 ratio. Manufactured in 24 colors: white, beige, yellow, etc. The opacity of the enamel depends on the color and ranges from 30 to 120 g / m2. Apply by brush or spray gun. Drying time from 8 to 24 hours. Shelf life – 12 months from the date of manufacture.
Enamel PF-223 It is used for painting wood and metal indoors on the ground and without it. Diluted to paint consistency with solvent gasoline, xylene, solvent or their mixture. Enamel is produced in 17 colors. Its coverage depends on the color and ranges from 20 to 240 g / m2. The drying time for this enamel is from 30 to 36 hours. Shelf life – 6 months from the date of manufacture.
Enamel PF-253 intended for covering floors on prepared surfaces in 2 layers using a brush. Diluted with solvent gasoline or turpentine. Drying times are different, depending on the thickness of the applied layer and temperature conditions.
Enamel PF-126 sold complete with a desiccant NF-1 (for 100 hours of paint weight 4 hours of a drying agent that accelerates hardening). It is applied with a brush or roller in 2 layers with intermediate drying in 30 minutes. The surface is pre-primed with diluted enamel, thinner – white spirit.
Enamels GF-230 and PF-560 available in different colors. The conditions for surface preparation and exposure are the same as for PF-126 enamel. Diluents – white spirit, turpentine, RS-2. You can add up to 5% desiccant (# 64).
Enamel for floor PF-226 over paints of this type (PF-253) has advantages in terms of hardness, water resistance, wear resistance, hiding power and drying time of the film. Enamel gives a shiny surface and dries completely in 24 hours.
Enamel FL-254 produced on phenolic oil varnish and used for floor painting. Has higher quality indicators in comparison with pentaphthalic floor enamels in terms of drying speed, hardness, gloss, wear resistance.
White enamel PF-14 is produced especially for painting joinery (door windows). Its advantage is that the paint does not drip from vertical surfaces, it is easily applied with a brush or roller in 1 layer and dries at room temperature for 30 minutes.
The next code is the first digit after the dash. It indicates the purpose and preferential operating conditions for paints and varnishes. The numbers from 1 to 9 are deciphered as follows:
1 – weatherproof
2 – limited weather resistance (operated under a canopy and indoors, both heated and unheated)
3 – protective preservation (intended for the so-called preservation coatings, which serve to protect metal products from corrosion for a short period, for example, during transportation from the manufacturer to the place of operation, the preservation coating is usually removed before putting the product into operation)
4 – waterproof (the coating formed from this material is resistant to hot water)
five – special (for example, coatings of which glow in the dark or scare off rodents) 6 – oil and petrol resistant (shows resistance to petroleum products)
7 – chemically resistant (resistance to aggressive gases and liquids)
8 – heat-resistant (the coating formed from the corresponding paintwork material will “work” at elevated temperatures)
nine – electrical insulating (high dielectric constant)
Text: Vitaly Lvova