Water-based paints have long entered our lives. Their latest variety - acrylic paintwork is very popular due to its advanced properties. The difference in the compositions determines the breadth of application of the types of water-dispersible material.
The German chemist Fritz Klatte in 1912 invented PVA glue. Three types of dispersion were discovered in series for water-dispersion paints in the first half of the 20th century: PVA dispersion is the first base, synthetic rubber is the second dispersion base, and the last dispersion is acrylic.
Reference: a homogeneous substance from liquids that do not initially interact is called dispersion. In the resulting emulsion paints there is a solvent (here - water) and a coloring part with various additives. Due to the fact that these 2 parts of the dispersion do not interact, they cannot mix forever - they will eventually fall into the original layers.
Any paintwork for this reason requires thorough mixing.
Two American artists in the 50s released the first acrylic paints that could not yet be dissolved in water, but were dissolved, for example, with turpentine. They were intended exclusively for a narrow scope - artistic.
One decade passed and in 1960, one of these two artists, Leonard Boku, created a completely water-soluble acrylic paint.
A little less than 30 years ago, Russia began to import acrylic water-based paints, which we did not produce then. Now their production is being established on the territory of our country, and we produce quite competitive products.
As can be seen from the history of the origin of water-dispersion materials, their types differ depending on the basis of dispersion.
The cheapest emulsion paints are based on PVA , as they dissolve with water and are unstable to it. But they retain color and are resistant to UV radiation.
They can be used only in indoor dry rooms (bathroom and kitchen are excluded) and on surfaces that do not require frequent and thorough wet cleaning.
The next type - styrene-butadiene quality is higher . Paints of this type are also applicable in interior decoration, they are more resistant to wear, but not to sunlight. They are not frost resistant.
The last and most high-quality variety of water-dispersion paint is acrylic . Belongs to the most expensive species due to the complex improved composition. It is almost universal and is intended for any internal and external surfaces on which it forms an elastic, abrasion-resistant film. This paint and varnish material is completely waterproof, has a temperature, UV resistance.
The solvent in water-dispersion paints is demineralized water, purified from mineral salts.
The copolymers forming a film on a painted surface occupy about 1/2 of the total mass. These will be:
- polyvinyl acetate , its emulsion in water - the well-known PVA glue;
- styrene butadiene - or synthetic rubber, resistant to water, unlike the first option, but unstable to UV radiation;
- styrene-acrylate , its smallest particles provide good adhesion, paints with this polymer have higher quality characteristics than paints with the first 2 polymers;
- acrylate forms a very strong bond to the surface, providing high protection from sunlight, paints based on it are one of the most expensive - they are widely used in exterior decoration;
- versatat , a new film-forming agent (it is also a copolymer) that has recently begun to be used in water-based paints, the paint with which has excellent qualities, but is cheaper than acrylate paint, is comparable in price to styrene-acrylate.
The following are various additives, which are also responsible for the properties and qualities of the paint, its scope:
- pigments themselves are the coloring base;
- thickeners (most often - CMC glue, or carboxymethyl cellulose) and preservatives;
- frost protection antifreezes;
- substances that reduce foaming, and those that improve the viscosity of the composition;
- anticorrosive additives;
- dispersants, the role of which in the composition is difficult to overestimate - they are responsible for preventing the separation of paint and varnish materials into components, in other words, they prevent particles from sticking together.
The cheapest white water based paint is made on the basis of chalk, has the appropriate qualities and purpose. The best quality white pigments are zinc oxide and titanium dioxide. Fillers can be several minerals at once: talc, mica, calcite.
Depending on the composition, the paint has certain technical characteristics. This means requirements for:
- drying speed of 1 layer;
- hiding power - is responsible for the consumption of paint;
- type of surface formed - its uniformity;
- pH level - neutral, low alkaline;
- degree of opposition to UV rays;
- wear resistance;
- possibility of use at low temperatures.
LC material for finishing work is selected taking into account these characteristics. Thanks to the right choice, he will fully comply with the conditions of use, will last a long time, showing his best performance.
The quality of the water-dispersion material depends on the copolymer of dispersion, from one of the 5 listed in the "Composition":
- polyvinyl acetate;
- styrene butadiene;
- styrene acrylate;
Let us consider in turn the properties of water-based paints containing one of them in the base:
- yellowing , lack of resistance to water, for this reason a narrow scope - only in rooms with a normal level of humidity, on surfaces that do not require wet cleaning, not exposed to mechanical stress;
- good water resistance, but exposure to UV radiation, the application is slightly wider, but still limited to indoor surfaces;
- porosity of the coating, which forms vapor permeability, resistance to light fading, tight adhesion to many surfaces - high adhesion, as a result of wider use, on internal and some external surfaces;
- the highest resistance to light, all the advantages are improved and allow you to actively use this type of acrylic water-dispersion paint in unprotected conditions of the natural environment - outdoors, that is, in the exterior decoration (facades from different materials - wood, plaster);
- excellent quality characteristics comparable with all the advantages of the listed acrylic paints.
Latex acrylic paints based on synthetic rubber - styrene-butadiene, with silicone additives, have several advantages:
- resistance to water - form a washable surface, applicable in rooms with high humidity;
- elasticity - will not crack;
- vapor permeability, but from a fungus it is better to use a preliminary primer;
- wear resistance - for rooms with intensive loads;
- variety of decorative effects;
Like all water-based paints, it is environmentally friendly, as it does not contain toxic organic solvents, it dries quickly, and is odorless.
All water-dispersible materials can be tinted, they are easy to use, resistant to alkali.
Acrylic paints retain their color, serve for a long time - 10-20 years, easy to clean, can be used for painting furniture.
Aqueous emulsion paints compares favorably with coatings based on organic solvents - enamels, varnishes as safe for health, non-combustible, quick-drying.
Water-dispersion paints have differences in compositions that determine their purpose, scope. Acrylic types are an advanced version of water-based paints. The difference between the first water-based paints and their modern compositions is significant. Progress brought them to a new level of application, and now they are one of the best multi-field coatings.
Minor disadvantages: you can paint at t from + 50C, you can not freeze this type of paintwork.
Acrylic is more expensive, but the price is justified by its qualities.
The wooden surface is time consuming to paint with water-based paint due to the high surface tension of the paint.
Scope of application
Artistic work, finishing works - internal, front. Water-based acrylic paints are used on wooden, concrete, brick, plastered, metal surfaces. Designers and artists make extensive use of these colors in their work.
See the following video for more information on the types of paints.