Copal

Fossil copal Fossil flour Fossil-fuel furnaces Fossil fuel prices Fossil fuels Fotoform/Fotoceram Fougere Royal Foundry alloys Foundry core binders Foundry furnaces Foundry resins Fountains Fourcault process... 

Manila copal [9000-14-0] Manila hemp Manioc Manjak... 

A varnish is often appHed on top of the paint layers. A varnish serves two purposes as a protective coating and also for an optical effect that enriches the colors of the painting. A traditional varnish consists of a natural plant resin dissolved or fused in a Hquid for appHcation to the surface (see Resins, natural). There are two types of varnish resins hard ones, the most important of which is copal, and soft ones, notably dammar and mastic. The hard resins are fossil, and to convert these to a fluid state, they are fused in oil at high temperature. The soft resins dissolve in organic solvents, eg, turpentine. The natural resin varnishes discolor over time and also become less soluble, making removal in case of failure more difficult (see Paint and FINNISH removers). Thus the use of more stable synthetic resins, such as certain methacrylates and cycHc ketone resins, has become quite common, especially in conservation practice. 

IManila Copal. The Manilas are collected in Indonesia and the Philippines. They are soluble in alcohols and ketones, and insoluble in hydrocarbons and esters. The resins soften between 81—90°C and have acid numbers of 110—141. Principal uses are in coatings and varnishes. 

Pontia.na.k. This resin is a copal and is similar to the alcohol-soluble Manilas. It is partially fossilized, so it melts at a higher temperature. Softening points range from 99—135°C, and acid numbers from about 112—120. Pontianak [9000-14-0] is used in specialty coatings and adhesives. 

Ka.un. This fossil resin, classified as a copal, is found in the South Pacific, primarily in New Zealand. It formerly was used in protective coatings. It is still used in the Kauri-butanol test (ASTM D1133) to determine the volume of thinner that can be added to a varnish formulation without causing turbidity. 

Natural resins such as dammar and Manila copal have been described in U.S. FDA Regulations (3). The Material Safety Data Sheets for these products issued by the importer describe them as nontoxic and nonaUergenic. 

In addition to shellac a number of other natural resins find use in modem industry. They include rosins, copals, kauri gum and pontianak. Such materials are either gums or very brittle solids and, although suitable as ingredients in surface coating formulations and a miscellany of other uses, are of no value in the massive form, i.e. as plastics in the most common sense of the word. 

Kopal-baum, m. copal tree, -brecher, m. copal disintegrator. -fimis, m. copal varnish, -harz, -gummi, n. copal resin, copal, -in-saure, /. copalinic acid. 

Kopolkerinde. /. copalche (or copalchi) bark. Kopal-lack, m. copal varnish, -luftlack, m. airproof copal varnish, -mattlack, m. dull copal varnish, -bl, n. copal oil. -saure, /, copalic acid. 

Lack-farbstoff, m. dye for lake making, -firms, m. lac varnish, lacquer lake varnish varnish. -fimislack, m. lac lake, -fiache, /. varnish surface lacquer coat, -harz, n. varnish gum, varnishing resin, esp. copal gum lac. -haut,/. lacquer (or varnish) film. 

The term synthetic resin was coined originally to distinguish these resins from natural resins such as rosin, shellac and the copals. Nowadays nearly all resins used in paint are synthetic, so the first term is often dropped. 

Morse s Powder (or Explosive). Inexpensive expl mixts, invented by C.A. Morse in 1880, consisting of NG and resin (colophony, copal, shellac, sandarac), with or without the addition of a nitrate or chlorate. The ingredients were disd in a common solvent, such as methanol, grained as the solvent distd off. Typical examples are 1)NG 25, rosin 75%(mixed with 50p methanol) 2) NG 10, rosin 22, K nitrate 68% (mixed with 20p methanol)... 

Natural resins Burgundy pitch Copal Dammar Japanese lacquer Pine rosin Wood rosin... 

In addition to the minerals, there are also some rock-forming homogeneous materials that have neither the definite chemical composition nor the distinctive crystal structure characteristic of minerals. Such materials cannot, therefore, be considered as minerals and are known as mineraloids. Obsidian, for example, a natural material that has been widely used since prehistoric times for making lithic tools and decorative objects, is a mineraloid. Obsidian has neither a definite chemical composition nor a characteristic crystal structure and is not, therefore, a mineral. Copal and amber are other mineraloids that since antiquity have been treasured as semiprecious gemstones. 

Natural resins Pine resins, sandarac, copals, mastic, dammar, amber, frankincense, benzoe, styrax, myrrh, (plant resins) shellac (animal resin) tar and pitch (from thermal treatment of plant resins or wood) Varnishes, coatings, waterproofing materials, paint binders, ingredients of cosmetic and pharmaceutical preparations... 

Resins older than 40 000 years are considered to be fossil resins. The fossilization of resins begins with polymerisation and forms ambers and copals. Most of the ambers are derived from components of diterpenoid resins with a labdanoid structure other ambers are based on polymers of sesquiterpene hydrocarbons such as cadinene, and may include triterpenoids less common ambers from phenolic resins derive from polymers of styrene. Figure 1.4 shows the skeletal structures of the components which make up the polymers occurring in fossil resins [141]. 

Copals, sometimes referred to as immature amber, originate from Africa, Asia or central American countries and derive from the Araucariaceae and Leguminosae families. Polymerised communic acid and agathic acid are found as the main compounds in these fossil resins. The extreme hardness of copal results from polymers of resin acids such as ozoic acid, an enantiomer of communic acid that can polymerize and thus enable fossilization [86]. They are still commonly used today for varnishing and protecting wood. 

Pyrolysis in the presence of tetramethylammonium hydroxide (THM)-GC/MS allowed the identification of high- and low-molecular weight components in manila Copal and sandarac fresh and artificially aged samples. The pyrograms showed signals due to the polymer fraction and to free diterpenoids [43]. THM-GC/MS has also been used to determine the molecular composition of Pinaceae resins, allowing the study of fresh, naturally and artificially aged samples [16, 44 46]. 

Py-GC/MS characterisation of diterpenoid resins using online trimethilsilylation with HMDS has been performed on fresh Pinaceae resins, manila Copal, sandarac, and Copaiba... 

D. Scalarone, M. Lazzari and O. Chiantore, Ageing behaviour and analytical pyrolysis char acterisation of diterpenic resins used as art materials Manila copal and sandarac, J. Anal. Appl. Pyrol.,68 69, 115 136(2003). 

---