Search results
Results from the WOW.Com Content Network
Related to the terpenes, resin acid is oxidized terpenes. Resin acids dissolve in alkalis to form resin soaps, from which the resin acids are regenerated upon treatment with acids. Examples of resin acids are abietic acid (sylvic acid), C 20 H 30 O 2, plicatic acid contained in cedar, and pimaric acid, C 20 H 30 O 2, a constituent of galipot ...
Structure of abietic acid, a component of rosin. Rosin is the principal component has been used for centuries as a flux for soldering. (Abietic acid in the flux removes oxidation from the surfaces of metals, increasing their ability to bond with the liquified solder.) Is approved by the US FDA as a miscellaneous food additive. [7]
Resin acids occur in nature as tacky, yellowish gums consisting of several compounds. They are water-insoluble. A common resin acid is abietic acid. [1] Resin acids are used to produce soaps for diverse applications, but their use is being displaced increasingly by synthetic acids such as 2-ethylhexanoic acid or petroleum-derived naphthenic acids.
The artist applies a ground that will resist acid. Ground is applied by dissolving powdered resin in spirits, by applying the powder directly to the surface of the plate, or by using a liquid acrylic resist. In all forms of etching the acid resist is commonly referred to as "the ground." An aquatint box is used to apply resin powder.
The plate's ground side is then dipped into acid, or the acid poured onto it. The acid bites into the surface of the plate where it was exposed. Biting is a printmaking term to describe the acid's etching, or incising, of the image; its duration depends on the acid strength, metal's reactivity, temperature, air pressure and the depth desired. [8]
Acid anhydride is added to the resulting mixture to build the molecular weight of the resin into roughly the same product as with the fatty acid process. However, the alcoholysis process produces a more randomly oriented structure. To remove the water produced as a by-product and to increase the reaction rate, surplus phthalic anhydride is added.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Pitch produced from petroleum may be called bitumen or asphalt, while plant-derived pitch, a resin, is known as rosin in its solid form. Tar is sometimes used interchangeably with pitch, but generally refers to a more liquid substance derived from coal production, including coal tar, or from plants, as in pine tar. [2]