Kauri-butanol
5495176
141375821
2007-06-29T11:57:22Z
Jlittlenz
2916973
link to NZ kauri,
The '''Kauri-butanol value ("Kb value")''' is an international, standardized measure of [[solvent]] power for a [[hydrocarbon]] solvent, and is governed by an [[ASTM International|ASTM]] standardized test, ASTM D1133. The result of this test is a scaleless index, usually referred to as the "Kb value". A higher Kb value means the cleaner is more aggressive or active. Mild cleaners have low scores in the tens and twenties; powerful cleaners like the old chlorinated solvents have ratings in the low hundreds.
This contrasts with the cleaning "horsepower" measurement of water-based cleaners and degreasers, which is the [[pH]] and which is the concentration of hydrogen ions in such a solution. Since solvent-based cleaners do not use water, they cannot have a pH. So they are commonly classified by their Kb value.
In terms of the test itself, the kauri-butanol value (Kb) of a chemical shows the maximum amount of the hydrocarbon that can be added to a solution of [[Agathis australis#Uses|kauri resin]] (a thick, gum-like material) in butyl alcohol without causing cloudiness. Since kauri resin is readily soluble in [[butyl alcohol]] but not in most hydrocarbon solvents, the resin solution will tolerate only a certain amount of dilution. "Stronger" solvents such as [[benzene]] can be added in a greater amount (and thus have a higher Kb value) than "weaker" solvents like mineral spirits.
[[Category:Standards]]
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