EXTRACT FROM "CHEMICALLY PROCTECTING CELLULOSIC STRING FROM MICROBIAL ATTACK" OREGON STATE UNIVERSITY 1994.
The ability of various biocides to protect cellulosic string from decay was investigated by measuring tensile strength after various periods of soil burial. Copper Napthenate, the biocide normally used in this process, provided little protection. Several chemicals including Copper 8 hydroxyquinolinolate provided good protection over a 10-19 week period. Below is a summary of the results comparing Copper 8 hydroxyquinolinolate with Copper Napthenate.
The treatment level are given in percentages of the chemical used by weight with the metallic copper % given in brackets. The original breaking strain of the strings was an average of 47.5kgs with a range from 51kgs to 54kgs.
Copper Napthenate versus Copper 8 hydroxyquinolinolate
Copper 8 hydroxyquinolinolate can be used effectively at much lower dosage than Copper Napthenate. Particularly in relation to the metallic Copper levels needed. Neither biocide can be easily used in its pure form so preparations such as Neptune products are made based on the actives. For example Neptune Copper Napthenate Cordage Treatment is a blend of 75% Copper Napthenate / 25% cordage lubricant and emulsifier. Neptune Copper 8 30% OE is a suspension of 30% Copper 8 hydroxyquinolinolate in cordage lubricant and emulsifier.
The metallic Copper content of the raw biocides is as follows:
Copper 8 hydroxyquinolinolate - 18%
Copper Napthenate 8%
The Metallic Copper content of Neptune products is:
Copper 8 30% OE 5.4%
Copper 8 10% OE 1.8%
Copper Napthenate 6.0%
To meet international standards the metallic Copper content required on ropes is about 10 times higher using Copper Napthenate as opposed to Copper 8 hydroxyquinolinolate.
Eg.
BS 2087
Copper Napthenate 0.5%-1.2% metallic Copper required on rope
Copper 8 hydroxyquinolinolate 0.03%-0.14% metallic Copper required on rope
Since the ratio of the price of Copper Napthenate (6%Cu) to Copper 8 30% OE (5.4% Cu) is approximately 1 : 3 it follows from the above that a sinilar level of protection can be had using Copper 8 hydroxyquinolinolate at about one third of the cost of using Copper Napthenate.
Our "Diamond VR" baler twine emulsifier is, in fact, Copper 8 30% OE. Tests on
sisal twines in the USA have shown that Copper 8 hydroxyquinolinolateis effective down as low as 0.008% metallic Copper content. (ie using 1% of Neptune Copper 8 30% OE to make the batching emulsionThis makes the product a viable, and more effective, alternative to standard baler twine treatments.
Other considerations.
1. Copper 8 hydroxyquinolinolate is not soluble in water whereas Copper Napthenate is. Therefore Copper 8 hydroxyquinolinolate is much more resistant to leaching by water.
2. The hydroxyquinolinolate part of the molecule acts synergistically with the Copper and increases the effectiveness - this is why lower metallic Copper levels can be used.
3. The spectrum of fungicical activity is much wider for Copper 8 hydroxyquinolinolate.
4. The lower Copper levels when using Copper 8 hydroxyquinolinolate are environmentally preferable.
5. Copper 8 hydroxyquinolinolate has food contact approvals in the USA and Europe.
We can't understand why anybody uses Copper Napthenate except for the nice colour!