Paints
Paints , also called paints or paints , are liquid to paste-like and, more rarely, powder-like substances or mixtures which, when applied to surfaces, result in a physically drying or chemically hardening coating . According to DIN 55945, a coating material is a "liquid to paste-like coating material that is mainly applied by brushing or rolling."
Structure and composition
A coating material is basically made up of: binding agent , colorant ( pigment or soluble dye ), filler , solvent , as well as any additives such as thickeners , dispersants and preservatives .
Paints or stains are paints, pigments (list of pigments included).
Classification
Paints are classified according to their film-forming binders . These in turn can be divided primarily into organic and inorganic binders and result in the product classes.
- Lacquer , glaze and oil paints
- Emulsion paints
- Lime paints
- Silicate paints
- Liquid plasters
Organic binders
Organic binders include
- Hardening oils (also known as " drying " oils) and resins crosslink oxidatively and are used in oil painting as well as in industrial colorants and varnishes .
- Natural , alkyd , acrylic , polyester and epoxy resins form the basis for lacquers or varnishes .
- Plastic dispersions made from acrylate polymers or vinyl acetate copolymers are part of commercially available emulsion paints.
- Casein is a special binder for lime casein paint and is still primarily used in restoration .
- Cellulose and other Leimgrundstoffe ( paste )
- Gum arabic has its role in watercolor painting
- Waxes are binders in encaustic
Inorganic binders
The inorganic binders include building lime , cement , anhydrite , ettringite and potassium silicate , which are used in construction and wall painting .
Natural colors
In the trade, paints are referred to as natural paints as soon as they consist predominantly of "natural" (what is meant is natural) materials . In contrast, “mineral paints” are those that contain mostly mineral components, such as marble flour or chalk. In the technical sense, only paints with mineral binders are considered mineral paints .
However, such trade names generally say nothing about the binders - which can certainly be acrylic resins - nor the pigments used to give the paint its color and opacity. The reason for the prominent designation natural color is the increasing understanding of the environment - although the connection between environmental protection and materials of natural origin is controversial. An essential aspect is the marketing in which the association of lay people with lime, glue, clay paint as natural paint or the "good reputation" of the Keim mineral paint is exploited.
Differentiation according to function
On the other hand, paints can be distinguished according to their function and use,
- Artist's paint : are mainly used in art painting of particularly high quality: oil paint , acrylic paint , tempera , water color , or ink and Indian ink .
- Wall paint: is intended for painting large areas with a corresponding price adjustment: usually emulsion paints , but also lime paints , silicate paint or glue paints . These are in turn divided into exterior and interior colors according to their weather resistance .
- Undercoat: should structure the work process in the area of wall paints: this also includes opaque paints or it is brushed or liquid plaster.
- Printing inks used in polygraphy are used for newspapers, books or packaging.
- Coating color is used to refine surfaces in the paper industry.
Differentiation according to the degree of coverage
It is expected that paints, colloquially referred to as paint , will cover the surface so that they are opaque. Multiple orders may be required for this.
Clear lacquer, stain , varnish and glaze , on the other hand, should allow the substrate to show through completely or partially. Stain, varnish and glaze can make the structure of the substrate stand out in different ways. They are often colored in order to change the color.
Preservation
In the case of liquid paints and pasty coating materials, such as roll-on or brush-on plaster, a distinction is made between container or in-can preservation and film preservation.
The former is a biocidal setting of the coating material in the container, i.e. in the packaging container, so that the product is not attacked and destroyed by microorganisms such as bacteria before it is used.
The film preservation is the biocidal finish for the finished coating after use. This is to prevent a biogenic attack on the hardened and dried state. This prevents the surface from being attacked by microorganisms such as algae or fungi. These active ingredients, such as fungicides, algicides and bactericides, have only limited water solubility so that they are not washed out when exposed to weathering. However, their effectiveness is often reduced or lost after a few years. If the surface is discolored due to microbiotic infestation (such as mold), the paint must be renewed.
literature
- Entry to paints. In: Römpp Online . Georg Thieme Verlag, accessed on June 20, 2014.
- Rudolf Karsten: Construction chemistry. Manual for study and practice . 9th edition. Müller CF, 1992, ISBN 3-7880-7438-8 .
