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JKTAN  N
Safety neutralizing agent for chrome leather

Jktan N is almost neutral in reaction and does not cause any precipitation of chrome.  It neutralizes very evenly and thus has many advantages over conventional neutralizing agents with regard to the quality of the resulting leather.

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Over neutralization with its well-known adverse effects for the leather quality is impossible with Jktan N.  Excessive amounts will even improve the leather quality by conversion of any unfixed chromium salts into tanning complexes.  Thus, in neutralizing with Jktan N, the leathers need, if any, only a light rinsing, and this alone is an advantage, all the more so since chrome tanning agent is also saved in this way.  In contrast to neutralizing agents with alkaline reaction, Jktan N causes no precipitation in chrome liquors, so that formation of undesirable chrome stains is unlikely.

Jktan N lowers the positive charge of the collagen – chromium complexes and thus levels out the pronouncedly positive charge of the chrome leather surface.  This is beneficial for applying anionic dyes and fatliquors, because very uniformly dyed and fatliquored leathers are thus obtained.

Vegetable and synthetic retannages have a mild and uniform effect after a preceding Jktan N neutralization; drawn grain and overtannage are avoided and a full leather with fine and tight grain and exceptionally good dyeing properties is obtained.

The properties of the product described above are particularly beneficial, if the soda bi carb, normally used, is replaced wholly or atleast partially by Jktan N already in basification of the chrome liquor.

The product can also be used in combination with other commonly used neutralizing agents, e.g. sodium bicarbonate.  In such cases, neutralization is commenced with Jktan N and the other neutralizing agent is added subsequently.

Without previous rinsing, the shaved leathers are drummed for 30-50 minutes with 1.5-3& of Jktan N.  the drumming time depends on the float length, the chromium oxide content and the thickness of the leathers which are subsequently thoroughly rinsed and further processed according to the standard method.

Neutralization of chrome leathers to be retanned.

Before retannage with vegetable or synthetic tannins, the shaved leather are drummed for 30-45 minutes with 0.5 – 0.8% of Jktan N, followed by thorough rinsing and further processing according to the standard method.

Basification in chrome tannage.

For basification in chrome tannage, replace 100 parts of soda ash by 170 parts of Jktan N.  the Jktan N solution can be added at once to the revolving drum without causing precipitation or chrome stains.

Testing the degree of neutralization.

The degree of neutralization is determined by spotting the cross-section of the leather with 0.1% bromocresol green solution which turns yellow in the stronger acid range (up to pH 3) and changes over pale green (pH 4) and blue green (pH 5) to blue (pH 6).  The inner zones of a properly neutralized upper leather should then be medium to dark green and the outer zones blue-green to blue.  For chrome leathers to be retanned, however, such an extensive neutralization is inadvisable, it will then suffice if the inner zones show a yellow green and the outer zones a medium green shade.