Rosin

Rosin is a yellow to brownish-black tree resin with conchoidal fracture and vitreous luster. The name is derived from the Lydian city of Colophon, which is considered ancient trading center for rosin. In modern times, the import was mainly from North America. It is a natural resin from the balsam of pine, spruce and fir trees ( conifers) or the tall oil obtained in paper production is produced. As rosin, the solid constituents of this tree resins are referred to, which remain after the removal of the volatile components ( turpentine ) by distillation. The resin content is about 70 %, the remaining ingredients are made up of about 20 % turpentine and 10% water together.

Rosin is also produced in the processing of fossil resins, in particular Baltic amber. This was for waste and is processed to Amber oil and succinic acid. After approximately 60 % of the initial mass remaining as rosin, which is mostly used in paint manufacture. Occasionally rosin is found on beaches of the North and Baltic Seas. There are mostly remnants of the cargo of sunken ships in storms or lost shipments, mainly from the 19th and early 20th century. These pieces are easily confused with amber (in this case the variety Gedanit ) or copal.

Properties

Rosin is brownish- transparent and splinter easily when cold. The main components are easily oxidized resin acids such as abietic and pimaric. Due to its amorphous structure has no definite melting point rosin. The softening temperature of this high quite different natural resin is generally 80-125 ° C.

Rosin is insoluble in water but readily soluble in alcohol and many other organic solvents.

Rosin can quite often cause allergic reactions, asthma, and severe eczema.

The fumes from rosin are considered as harmful.

Use

Electronics / soldering

Rosin was used earlier in the electronics manufacturing as an activator and a flux for soldering, has been largely superseded in this application, by flux on alcohol or water base with halogen-free activation additives such as stearic acid, salicylic acid and adipic acid.

The organic acids present in rosin have a reducing effect at high temperatures and eliminate the oxide layers of the metallic joining partner. Furthermore, it results in a smooth surface of the solidified solder, since it is also here avoided by its presence, an oxidation of the melt. It can remain as a thin layer on the solder joint, since, in contrast to soldering paste or fluid does not cause corrosion - it protects them from the influence of oxygen and subsequent electrolytic corrosion. However, it is often washed off for aesthetic reasons and replaced by a protective coating.

It is included in the flux core of cored solder pastes and also in surface mount technology ( SMT ). Rosin also served as a flux for wave soldering. Löttinktur for electronics soldering consists of alcohols dissolved in rosin, in turn, also function as reducing agents.

Rosin

Geigenkolophonium is a refined with various substances rosin. It is also called a sheet or rosin. The horsehair bows of string instruments are regularly rubbed with a piece of resin to obtain a strong stick-slip. When painting the string provides this rapid change of static friction and movement between bow hair and string the string to vibrate.

There are different qualities, ranging from easy playability for beginners to artists rosin, which allows a greater dynamic and tone scale. In general, a softer resin is used as for the thicker strings a larger static friction is required for Double Bass.

Paints / Coatings

Rosin is sputtered as grated dust on etching plates and then heated briefly. This creates a fine grid of rosin - beads that help in the artistic gravure surface colorations are possible. We call this technique aquatint.

Rosin was used along with other natural resins, such as mastic, copal, dammar, amber and Sandarak in mixtures for paint production. As a violin varnish was replaced since the material is too brittle, and generates a low -resistant paint film. In natural colors and wood oils, it is used as a desiccant.

Rosin is included in solderable protective coatings for printed circuit boards.

Furthermore, rosin may be part of certain seal coatings.

Other applications

Rosin is also suitable as an aromatic incense, it acts antiseptic and stimulates blood circulation. But for no rosin should be used, which was produced for technical applications such as soldering, since this can contain undesirable additives.

In sports, especially handball, rosin dissolved in alcohol is rubbed as an adhesive on the ball. Thus, the ball sticks literally by the hand of the athlete. However, this is prohibited in many halls of cleanliness reasons. When climbing rosin is ( which is there referred to as Pof ) applied mainly in the sandstone on the hands to improve the adhesion on the rocks. Usually magnesia is used, but this is illegal in some areas. Dancers and weightlifters use rosin for their shoes and that they are less slippery.

Another use of rosin in the manufacture of pyrotechnic Zündlichter. Similarly with shellac can be prepared using a rosin moldable material.

Greek fire consisted of a varying depending on the tradition source proportion of rosin.

Rosin is also used in some adhesives and may be a component of the tree wax.

With alkalis rosin forms salts, (so-called resin soaps), find use as emulsifiers and for sizing paper.

As Brühpech (also butcher resin Saupech or Brühharz ) it is used for dehairing of pigs and poultry. The slaughtered animal is dusted it and scalded with 70 ° C hot water. By the resin, the hair can be scraped off more.

Rosin is also used as a filler in the rolling of aluminum hollow profiles, in order to prevent the rolling material occurring during compression of folds on the inner radius and the outer radius Dehnungseindellungen low to completely (depending on the rolling radius ). The rosin is heated, liquefied and is filled in by the one-sided closed hollow profile. After solidification, it can be rolled using a rolling machine and adapted to the einzurollende Profile Profile rollers to the desired radius. To empty the rolled profile to liquefaction of the rosin must be reheated.

Heated and dissolved in a non-drying oil such as olive oil can be produced from a rosin Leimring for trees produce, the year-round remain on the bark and at any time can be renewed. The ring remains sticky and prevents the infestation of the tree with crawling and running insects, such as ants.

A mixture of 60 % rosin, 15 % sulfur and 25 % iron filings called Silberkitt. This was particularly Silberkitt used in the past for filling hollow silver devices.