Alkyd resin paint
Drying alkyd paints (or short alkyd paints or colors ) are classic decorative paints , up to the widespread use of water- acrylic paints in the DIY sector as a universal paints were used. They are particularly suitable for painting wood and metals indoors and outdoors.
The term alkyd was introduced in 1927 by RH Kienle and is made up of alcohol and acid . To distinguish it from the oil paints based on hardening oils and natural resins that have been used to date , alkyd resin paints are also referred to as synthetic resin paints . Compared to classic oil varnishes, more predictable properties, as well as a higher degree of gloss, faster drying and better color fastness can be achieved with alkyd resin varnishes.
The basis of the manufacturing process is the esterification of polyhydric alcohols with fatty acids or oils . Depending on the size of the oil content, one subdivides into short, medium and long oil alkyd resins and furthermore into drying and non-drying alkyd resins. Non-drying alkyd resins are the basis for paint systems in which they are reactants ( e.g. stoving paints in the automotive sector).
Known oils such as linseed oil , castor oil or olive oil are used as esterification partners for the polyalcohols ( e.g. glycerine , trimethylolpropane , pentaerythritol and sorbitol ) and the acid anhydrides (polybasic carboxylic acids such as phthalic , isophthalic , adipic and sebacic acid ) . The unsaturated fatty acids are esterified with the remaining free hydroxyl groups of the polyhydric alcohols.
In order to adapt the alkyd resin paints even further to the requirements, they are subjected to the so-called modification. Reaction partners such as polyamides are incorporated, which influence the subsequent crosslinking in the desired direction. The drying time is reduced by adding oleates or naphthenates of cobalt , lead and manganese . The latest development steps are in the direction of water-based systems and high- solid paints.
Alkyd resin varnishes can usually be mixed with oil paints , oil varnishes and nitrocellulose (cellulose nitrate) in any ratio. Combinations with many other film formers are also possible, for example with phenolic resins and epoxy resins .
As a rule, white spirit ( white spirit ) or universal thinner are used as solvents .
See also
Individual evidence
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