turpentine
As turpentine are (balsam oil, pine oil, also known as gum rosin) fresh Harzausflüsse various conifers , especially pines ( spp Pinus. ) And larch ( Larix spp. And then used to be Gloriet and Loriet ), respectively. They are mixtures of resin and essential oils and belong to the group of balms . They only change into resin when they dry out, with the loss of volatile substances.
Turpentine is a colorless to yellowish, mostly creamy liquid, the main components of which are resin acids . The volatile constituents mainly found 2- pinene , 2 (10) -pinene , 3-carene and other (monocyclic) monoterpenes in very different proportions depending on their origin. Turpentine is harmful to health and the environment. The CAS number for the mixture is 9005-90-7.
Oil of turpentine (also turpentine spirit or turpentine ) is obtained from turpentine by distillation . It is a very volatile, oil and resin dissolving agent. The CAS number for this is 8006-64-2. The distillation residue is called rosin .
properties
Turpentine is a viscous, cloudy, almost white or white-yellow mass. The resin is insoluble in water, but can be dissolved in oils , ethanol and alkalis . The harmfulness to health and environmental hazard of the mixture are strongly dependent on the pinene and 3-carene content. The resin acids or rosin can cause allergies .
Extraction
To obtain the excretions formed between the wood and the bark or in special cavities in the tree, the bark is incised vertically like a channel and the mass is collected in special depressions or containers placed underneath at the bottom of the incisions. Another option is to drill into the trunks. The holes are closed with a plug and the balm is allowed to flow out from time to time. The extraction begins in spring and lasts until autumn. Trees with thick bark that are exposed to the sun have the greatest yield.
cleaning
The collected mass, often contaminated by earth, sand, needles and bits of bark, is liquefied by melting at low temperature, strained through coarse cloths or a layer of straw and then poured into barrels. In the United States, they are simply exposed to the heat of the sun in drums with a perforated bottom, whereupon the pure turpentine drips off by itself. Turpentine is also purified in this way in France. The thick variety there is called Pâte de térébenthine au soleil , the thin one à la chaudière .
species
The turpentines are honey-thick, very viscous, depending on their origin, clear or cloudy, aromatic smelling and tasting masses, which, despite their largely identical composition, show deviations in consistency, color, smell and oil content. According to the countries of origin, they are divided into the following commercial varieties, the high-quality also being called "noble turpentine":
- The common, common or German turpentine (lat. Terebinthina communis ) is obtained mainly from the Scots pine ( Pinus sylvestris ), less often from the white spruce ( "Strasbourg turpentine") and red spruce ( Picea abies ). It has a tough, somewhat grainy consistency, is yellowish-white in color and cloudy and has a strong resinous odor and bitter-spicy taste. Austrian turpentine (Latin: Terebinthina austriaca ) comes from the black pine ( Pinus nigra ), which is particularly widespread in the Vienna Woods , and is shipped from Lower Austria in so-called Lägeln, small oval barrels. French turpentine is particularly called the deposit of the maritime pine ( Pinus pinaster ), which forms forests in various areas of southern France. It is thinner and finer and has a pleasant smell. The American turpentine of the bog pine ( Pinus palustris ) does not differ much from the common one and therefore falls into the same group.
- The best variety of turpentine is the Venetian or larch turpentine (lat.Terebinthina veneta or Terebinthina laricina ), which is obtained mainly in Tyrol , Carinthia , Styria and further east to Hungary from the European larch ( Larix decidua ). But there are also larch forests in Provence that provide real Venetian turpentine. The thick, sticky, rather transparent mass is only slightly yellow in color, strongly stringy and slowly drying. It has a resinous-spicy, somewhat lemon-like odor. Turpentine boiled from larch cones is inferior. The resin that remains is splintery and attacked by atmospheric influences.
- North America produces the finest of all types of turpentine, Canadian turpentine , known as Canada balsam .
- The other turpentines such as Hungarian and Cypriot turpentine from the turpentine pistachio ( Pistacia terebinthus ) are of little importance. Italian turpentine (Latin: Terebinthina italica ) comes from the same areas as Venetian, but is darker in color.
use
Turpentine is mainly used resins softer and more pliable, and therefore as an additive for sealing lacquers , Harzfirnisse , varnishes , putties and Ätzgründe used. Only the water-free Venetian variety can be used for the production of varnish, otherwise cloudy varnishes will result. In contrast to ordinary water-containing turpentine, it burns without a crackling noise. Turpentine is also often used as an additive to ointments , plasters , soaps and hoof putty . It is also the raw material for the production of turpentine oil and rosin . In addition, it is used as an important binding and thinning agent in oil painting . Previously, for example, were marble washbasins and -floor with a mixture of beeswax and turpentine entered. In the restoration of this method is still used. It was also processed into lubricants , mostly with wood tar and the like. a. mixed. See also: lubricator
See also
Individual evidence
- ↑ Eva Shenia Shemyakova: 'Des Juden buch von kreuczenach'. Investigation and edition of the recipe part of the Heidelberg Cpg 786. In: Fachproseforschung - Grenzüberreitungen. Volume 8/9, 2012/13, pp. 207–265, here: p. 230.
- ↑ Jürgen Martin: The 'Ulmer Wundarznei'. Introduction - Text - Glossary on a monument to German specialist prose from the 15th century. Königshausen & Neumann, Würzburg 1991 (= Würzburg medical historical research. Volume 52), ISBN 3-88479-801-4 (also medical dissertation Würzburg 1990), p. 148 ( Loriet : Lärchenharz, Harz from Larix decidua Mill. Or from others Pinus or Larix species).
- ↑ Entry on turpentine oil. In: Römpp Online . Georg Thieme Verlag, accessed on June 13, 2014.
- ^ Entry on turpentine. In: Römpp Online . Georg Thieme Verlag, accessed on June 13, 2014.
