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Cobalt Octoate Driers
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| Cobalt is an extremely active & most widely used drier in coatings
& capable of being used even as a single Drier. It is primarily an oxidation catalyst & acts as a " Surface
Drier ". It may have a tendency to cause surface wrinkling, hence to provide uniform drying. Cobalt is generally used in
combination with other metals, such as Manganese, Zirconium, Calcium & Combinations of these metals. As quantity of Cobalt Drier used is very small, it minimizes
discoloration in paints & enamels as compared with other Driers. Cobalt does not discolor white paints as the deep blue color
of the cobalt counteracts the yellow of the oils & resins & thereby enhances the whiteness of the paint. The unique
feature of cobalt is that it is least affected by atmospheric
humidity. Cobalt is an effective accelerator for polyester.
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Manganese
Octoate Driers |
Manganese driers are intermediate in activity & they have both
oxidizing & polymerizing properties. When manganese used alone it may produce too hard & too brittle films. When used
in combination with Lead, hard tough & durable films are produced.
One disadvantage in use of manganese driers is their relative dark
color, which has a tendency to discolor white or light finishes. |
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Lead Octoate Driers |
| Lead is a through drier & is always used with cobalt &/or
manganese. Lead drier improves the drying time of double boiled linseed oil & yields very pale & clear boiled
oil. Lead in combination with cobalt & calcium are suggested,
particularly for long oil alkyds lead is the most important drier. However some of the problems connected with lead
driers such as Sulphur staining & reaction with polybasic acids are overcome by inclusion of calcium
drier. As lead is toxic in nature its usage in toys & edible film packaging is to be avoided. |
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Calcium Octoate Driers |
| Calcium being an auxiliary drier, has little drying action in
itself but is very useful in combination with active driers. In vehicles that show poor tolerance for lead, calcium can replace
part of the lead with a larger amount of calcium to prevent the precipitation of the lead & maintain drying efficiency. Calcium is also useful as pigment wetting & dispersing agents & help to improve hardness & gloss &
reduce "Silkins". When ground with drier adsorbing pigments,
Calcium minimizes loss of dry by being preferentially absorbed. |
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Zinc Octoate Driers |
| Zinc being an auxiliary drier, used in conjunction with redox metals.
The primary function of zinc is to keep the film "Open" by retarding Surface dry, thus permitting
hardening through out & preventing surface wrinkling, particularly in Cobalt containing films & enamels. Zinc is a powerful wetting & dispersing agent, & when
incorporated early in formulation, it greatly reduces the time of mixing & grinding. Because of the extremely light colour, Zinc can
be added without discoloring the film. |
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Zirconium Octoate Driers |
Zirconium is a most useful & efficient auxiliary drier.
Zirconium like lead serves as a through drier & is generally used in combination with Cobalt, Manganese & Calcium. Unlike Lead,
Zirconium is a poor pigment wetting & dispersing agent.
Zirconium is an active cross-linking agent & as such improves
hardness of stoved films as well as their adhesions.
Zirconium is not as effective in Phenolic resin based media it is
recommended as a catalyst for epscy esters. Use
of Lead driers in combination with Zirconium is to be avoided totally. |
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| Copper Octoate Driers |
Copper is an anti fouling agent. It is used in ship bottoms
paints. Copper Octoate Hydrolyses gradually in to Copper Hydroxide & Octoic Acid in the presence of seawater, Copper
Hydroxide is an active toxicant.
It is used as a rot proofing agent in
textiles, cordage etc. & to prevent dry rot & mildew growth in
timber, its insecticidal property is taken advantage of import a long
lasting protection against termites, beetle & ambrosia & many other insects attacking timber/lumber, Copper may be
applied on textile fabrics by dipping, spraying or impregnation. The recommended dosage is 2% to 2.5% as
metal. |
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| Iron Octoate Driers |
| Iron is used backing finishes since it promotes rapid drying by
polymersisatoin. It is an excellent wetting agent for Carbon black & iron oxide. It prevents adsorption of driers on
the surface of the pigment & increases gloss. In air dry finishes it is useful in eliminating film tackiness of
paints containing a high percentage of non drying oil component such
as fish oil. |
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