CS213869B1 - Process for the production of bleaching and filling tanning agents - Google Patents

Abstract

Method for producing bleaching and filling tannin from naphthalenesulfonic acids, formaldehyde and urea. The invention relates to the field of production of synthetic tanning auxiliaries. It solves the production of bleaching and filling tannin from a mixture of naphthaleneone, di and trisulfonic acids by condensation with formaldehyde and subsequent condensation in the presence of urea. The addition of aluminum or zirconium salts achieves a higher bleaching and filling effect. The invention can be used in all production plants of tannins and products in the tanning industry.

Description

SUMMARY OF THE INVENTION The present invention relates to a process for the production of bleaching jaws from naphthalene mono, dl and trisulfonic acids condensed in an acidic medium having an acidity of 200 to 500 mg KQH, where the filling performance is achieved by additional condensation in the presence of formaldehyde and urea.

In the treated condensate ae, it achieves an increased filling and bleaching effect on the leather by the addition of aluminum, magnesium, zirconium or trivalent chromium salts.

The original author's certificates protected the production of tanning substances from a mixture of naphthalene mono, di and trlaulfonic acids in a strongly acidic environment by condensation with formaldehyde. The condensates thus prepared have excellent dispersing effects on tannins and, when applied during the tanning process, substantially speed up the process. When applied to chromium tanning wounds, their effect on better use of chromium tanning baths as well as on better filling of leather and certain bleaching effects on the color of the resulting leather was found.

The improvement of the bleaching performance 1 was achieved by the process according to the invention, in which the condensation medium of the naphthalene sulfoacid mixture is subjected to additional condensation and urea using both unreacted formaldehyde residues from the first condensation and additional formaldehyde. 5 to 3 hours at 50 to 80 ° C. The molar ratio of naphthalene to urea is 1: 0.01 to 1: 0.05, and the molar ratio of formaldehyde to urea is 1: 1 to 1: 2.

Further improvement of the filler and especially the bleaching properties of the so produced tanning agent was achieved by the addition of zirconium salts, chromium, aluminum or magnesium, either in the form of common salts or basic salts, eventually it is possible to use water-insoluble forms. in the reaction mixture. The amounts thereof vary depending on the desired properties of the final product and are in moles. ratio to naphthalene in the range of 0.01 to 0.1. Mixtures of these salts may also be used depending on the desired properties. The aforesaid salts can also be added before condensation with urea, possibly after neutralization. The resulting product can be used in the liquid state or after drying in a spray drier.

The process according to the invention is illustrated by the following application examples, which are only a few of many possible variants:

Example 1

Into an autoclave equipped with stirrer and cooling, add 38 kg of sulfuric acid, heat to 80 ° C and add 35 kg of naphthalene. Sulfonate in a sealed reactor for 6 to 6 hours at 120 to 160 ° C. After completion of the sulfonation, add 40 kg of water to the autoclave and gradually add 15 kg of 36% formaldehyde while stirring. We maintain the temperature in the range of 100 to

120 ®qp ₀ <j _O b _U 2 hours Do not dilute the condensate by adding 10 kg of water and add 3 kg of urea while stirring and gradually add 5 kg of Formaldehyde 36%. Maintain the temperature at 60 to 70 ° C for 30 to 45 min. The resulting product is neutralized with ammonia water. pB 3,2 to 3,6 and dry in spraying room ·

Example, 2

To the acidic condensate and urea of Example 1, add a solution of 5.3 kg of basic aluminum sulphate in 10 kg of water with stirring, neutralize with caustic soda to pH 3.4 - 3.8 and dry in a spray drier.

and

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Example 3

Add 100% of water to the tanning drum, calculated on the weight of the wort, add the wort, wash and decalcify according to common practice. Acidate with formic acid to pH 6.5 to 7.0, wash with 100% water 25 ° C. To the new bath of 50% water add 3% of naphthalene sulfoacid condensate on the move and after 30 minutes of movement, gradually acidify 0.4% of the sulfuric acid and formic acid mixture to the pH of 3.8 to 4.5 over 60 minutes. To this bath, add 6% basic chromium (II) sulfate and a CrgO 3 content of 26% and allow to stand overnight after 240 minutes of movement. Add 50% water at 35 ° C and neutralize with 0.1% sodium bicarbonate to pH 4.8 to 5.2.

Then add 10% of the product produced according to Example 2 and after 120 min. tanning 5% anionic liqueur. Other operations according to operating conventions.

Claims (2)

PÍEíMĚIVINÍLEZH Process for the production of a filler and bleaching tanning agent from naphthalene acids by mono-, di- and trisulfonic acid condensations with an acidity of 200 to 500 mg KOH (g of a sulfonation mixture, characterized in that the condensation of naphthalenesulfo acids with formaldehyde is completed 50 to 80 ° C using urea with additional formaldehyde at mol. urea to naphthalene sulfoacids ratio of 0.01 to 0.05 and formaldehyde to urea molar ratio of 1: 1 to 2: 1, the second condensation time being in the range of 0.5 to 2 hours · 2. A process according to claim 1, wherein aluminum or zirconium salts of aluminum or zirconium are added to the resulting naphthalene sulfo acid and urea condensate in a molar ratio of these cations to naphthalene sulfo acids of from 0.01 to 0.1 l.