FI65449C - FOERFARAND RAMSTAELLNING AV ETT TITANGARVMEDEL OCH FOERFARANDE FOER GARVNING AV LAEDER UNDER ANVAENDNING AV TITANGARVMEDEL - Google Patents

Description

2 65449

One known method for preparing titanyl sulfate involves treating the titanium-containing starting material with sulfuric acid, whereby the titanium is introduced into a sulfuric acid solution from which the titanyl sulfate is recovered by neutralizing the solution with lime, filtering off calcium sulfate and evaporating the filtrate to dryness (cf. DE patent no.

However, this prior art method is complicated, it is difficult to obtain the product in a form suitable for use as a tanning agent, and in addition, the tanning agent thus obtained does not have strong tanning properties.

A method for preparing a titanium tanning agent from solutions containing titanium and ferric ferrions is known in the art. This method involves introducing an oxidant into a starting sulfate solution containing titanium and ferric ferrions, followed by the addition of ammonium sulfate and sulfuric acid to precipitate the double salt of titanyl and ammonium sulfate as a monohydrate (NH 4) 2 TiO (SO 4) 2 · Η20, which is then stabilized by washing SU Inventor's Certificate No. 668 878, 1979). However, the tanning agent prepared by this method still contains an undesired amount of impurities.

A process is also known in which this titanylammonium double salt is used for tanning hides which have been descaled and pickled and chromed (cf. U.S. Patent No. 3,938,951, 1976). However, the resulting leather does not have the required quality properties.

It is an object of the present invention to improve the quality of a titanium tanning agent as well as to improve the tanning method so as to obtain a leather with better quality parameters.

The process for preparing a titanium tanning agent according to the invention is characterized in that the sulphate solution of the peroxytitanium complex is added to the starting sulphate solution as an oxidant so that the residual concentration of the complex in the starting solution is 0.01-2 g / l, calculated as titanium dioxide.

The use of a peroxy-titanium complex solution allows a slight oxidation and thus makes it possible to avoid over-oxidation of the starting solution and under-oxidation of the Ferro-iron contained therein. Thus, the 65449 3 peroxy-titanium complex solution ensures an efficient iron oxidation process under mild conditions, thus improving the quality properties of the resulting tanning agent. The peroxy-titanium complex solution should be added in an amount that ensures that the residual concentration of the complex in the starting solution will be 3.01-2 g / l calculated as titanium dioxide. In this case, all Ferro-iron present in the solution is converted to Ferri-iron. Increasing the residual concentration of the peroxy-titanium complex in the solution above 2 g / l calculated as titanium dioxide is undesirable because it gives a lower titanium yield to the final result, while reducing its concentration below 0.01 g / l calculated as titanium dioxide is technologically unsuitable. In addition, the use of a solution of peroxy-titanium complex improves working conditions because this product is neither dangerous nor toxic.

According to the present invention, the precipitation of titanyl ammonium bisulfate is carried out until 75-85%, calculated as titanium dioxide, is formed, after which the precipitated salt is separated and washed; the resulting filtrate and washings are combined and treated with ammonium sulfate to ensure post-precipitation of the salt, which is then separated and returned to the starting solution. This method of precipitation contributes to the further purification of the salt from impurities that may be present in the solution.

Thus, the advantage of the process according to the invention is that it makes it possible to prepare a tanning agent with a minimum content of iron (0.05% less Fö2®3) as well as other impurities. The process according to the invention makes it possible to use a sulfuric acid titanium-ferriferrol solution with an iron content higher, namely greater than 10 g / l FeO, while obtaining a high-quality tanning agent. These advantages make this method more commercially promising compared to prior art methods, while the use of a tanning agent made by the method of the present invention makes it possible to improve the quality of tanned leather.

This object is also achieved by a method for tanning descaled hides using a tanning agent prepared by the method described above, the method comprising treating the hides with tanning agents selected from the group consisting of disulfodinaphthylmethane sodium salt, phthalic anhydride, aluminum alum, urinalium 4, aluminum alum ammonium titanyl sulfates and phenolic oligomers dispersed in lignosulfonic acids, followed by treating the bed with the titanium tanning agent of this invention.

The sodium salt of disulfodinaphthylmethane is added 1.5 to 2.5% by weight per year, phthalic anhydride 1.2 to 2.2% by weight per year, aluminum alum 1.0 to 3.0% by weight per year, a mixture of aluminum alum with urotropin 1, 8 to 5.0% by weight per year, with a mixture ratio of 0.5: 1 to 3.4: 1, ammonium titanyl sulphate 5 to 15% by weight per year and phenolic oligomers dispersed in lignosulphonic acids 2.5 to 5.0% by weight calculated from years.

When using phenolic oligomers dispersed in lignosulfonic acids, the skins are preliminarily chromated.

The use of the tanning agents according to the invention speeds up the tanning process, increases the temperature resistance of the semi-finished products, thus giving a better quality final leather, for example the wear resistance of leather under dry conditions is increased by 10-20% compared to the prior art.

The tanning agent according to the invention is also suitable for the tanning of descaled hides and for the tanning of descaled and pickled hides, as well as for the tanning of descaled hides which have been pickled and chromed, in which case the tanning agent is titanium. a tanning agent in the presence of a substance selected from the group consisting of lactic acid, aluminum alum and condensation products of synthetic fatty acids with triethanolamine. These substances are added to the tanning bath in an amount of 0.5 to 2.5% by weight, based on the year. The resulting semi-finished leather should preferably be treated with chloroprene rubber latex, which is used in an amount of 1.0 to 6.0% by dry weight (years by weight) to improve the final wear resistance of the leather.

The use of these substances in tanning with a titanium tanning agent makes it possible to increase the volume yield of the leather and reduce its water absorption.

The method of the present invention makes it possible to produce a lightweight elastic leather with improved wear properties, water absorption and hydrothermal stability.

65449 The titanium tanning agent of this invention is prepared as follows.

The titanium-ferriferro concentrate is treated with sulfuric acid. The treatment conditions, namely: temperature, duration and acid concentration depend on the composition of the concentrate used. The cake obtained from the treatment is extracted with water using recovery solutions; titanium enters the solution while being freed from residual insoluble impurities. The precipitate is filtered off, washed with water, which is then used for extraction as a recovery liquid.

An oxidizing agent is added to the titanium-ferric ferrous sulfate solution obtained from the cake extraction; a sulfuric acid solution of the peroxy-titanium complex is used as such an oxidant.

The peroxy-titanium complex is obtained by oxidizing a portion of the stock solution obtained after extraction of the cake. The oxidation can be carried out with any known oxidizing agent, such as ozone, hydrogen peroxide, ammonium persulfate or electrolytically, etc. An excess of 0.01 to 0.2 g / l, calculated as TiCl 4, of the peroxide-titanium complex is added in a stoichiometric amount needed to convert Ferro iron to Ferri iron.

After the peroxy-titanium complex is introduced into the starting solution, ammonium sulfate and sulfuric acid are added thereto to a total concentration of free ammonium sulfate and sulfuric acid of 450 to 600 g / l. From the solution thus prepared, double sulphate of titanyl and ammonium monohydrate is precipitated in the form of (NH4) 2TiO. (SO4) 2 «BjOrn. The duration of precipitation under discontinuous process conditions is 5-20 hours. The precipitation temperature of the salt is 12 to 30 ° C. At temperatures above 30 ° C, anhydrous double sulphate of thianyl and ammonium may precipitate, making it unsuitable for use as a tanning agent. The residual titanium content in the solution after salt precipitation is 3-10 g / l TiO 2 · The recovery rate of titanium from the starting material to the salt varies from 55 to 90% depending on the concentrate used.

The salt obtained is filtered off and washed with a solution containing 300 to 450 g / l of sulfuric acid and 180 to 300 g / l of NH4 ^ SO2 and used in an amount of 0.4 to 0.7 m ^ per tonne of salt. In this way the salt is purified of impurities The filtered and washed salt is treated with a solution containing 300 to 400 g / l of ammonium sulphate and consuming between 0.4 and 0.7 m / tonne of salt to stabilize the monohydrate form of the salt, the titanium salt being a white powder. is the form of isotropic crystal quadrilaterals The composition of the salt is as follows, in weight percent: TiO 2 to 19.21, SO 3 to 44.48, (NH 4) 20 to 15-17, Fe 2 O 3 to 0.05, insoluble not more than 0.3 of the residue, the remainder being moisture.

Another embodiment of the process of this invention may be used to prepare a titanium tanning agent from sulfate-titanium-ferriferrol solutions containing more than 15 g / L FeO, wherein after introduction of the sulfuric acid solution of the peroxytitanium complex into the starting solution, the titanium salt is precipitated with ammonium sulfate and sulfuric acid until formed 75-85% calculated as titanium dioxide. The total content of free ammonium sulphate and sulfuric acid is 300 to 400 g / l. The precipitated salt is separated off and washed with a solution containing 350-450 g / l of ammonium sulphate. The content of impurity iron in the titanium salt is 0.03 to 0.05%. The filtrate and washings obtained are combined and treated with ammonium sulphate for post-precipitation of the salt to a total ammonium sulphate and sulfuric acid content of 450-600 g / l. The salt is separated and returned to the starting solution because it has an iron content of 2-3%. The degree of precipitation of titanium in this case is 13-22% of its initial content. The yield of the titanium double salt using the recovered product after three recoveries is 95-98%.

The titanium tanning agent prepared by the method described above can be used for tanning hides. The parking method is as follows. Hides from large horns (slag, bleed waste) are placed in a drum, poured into water at a temperature of 23-26 ° C, a water / leak ratio of 1.2 and then tanning aids are added to the drum (% by weight of the hides): disulfonaphthylmethane sodium salt 1.5 -2.5%, or phthalic anhydride 1.2-2.2%, or aluminum alum 1-3%, 7 65449 or a mixture of aluminum alum and urotropin 1.8-5.0% with a ratio of 0.5-3 , 4: 1, or ammonium titanyl sulfate 5-15%.

These activating agents make it possible to speed up the tanning process and improve the bonding between the titanium tanning agent and the collagen. This results in an increased concentration of tanning agent in the leather, which improves the quality of the leather: its volume-to increases with better water resistance; water absorption decreases.

After treatment with activating agents, titanium tanning is performed. For this purpose, titanium tanning agent is added in an amount of 4-6% by weight per year, calculated as TiO2, and ammonium sulphate in an amount of 4-6% by weight per year. The amount of tanning agent and ammonium sulfate depends on the density and thickness of the skins. When the drum rotates for 18-20 hours, the tanning takes place. The resulting semi-finished leather is then neutralized with sodium sulfite and urotropin, which are also added at 3.5% by weight of the comb.

Neutralization is stopped when the pH of the semi-finished leather is 4.0-4.5. The semi-finished product is rinsed and post-tanned with synthetic tanning agents using 15-17% tannins by weight of the hides. Post-tanning is performed with a water-flow ratio of 1.2-1.4, at a temperature of 38-43 ° C for 2-3 days.

The semi-finished product thus prepared is rinsed, water is squeezed out, it is compacted by dipping in a filler and greased. Magnesium sulphate 5-10% and molasses 5-10% are used for dipping compaction. Skin degreasing is performed using solid synthetic skin degreasers. The other finishing steps are performed in the usual way.

When descaled and pickled and chromed hides are used, the pickling process is carried out with sulfuric acid in the presence of sodium chloride or ammonium sulphate. The amount of acid consumed is 0.9-1.0% by weight per year, the consumption of sodium chloride and ammonium sulfate is 6-7% by weight of the years; the water / leakage ratio is 0.8-1.0, the temperature is 18-20 ° C and the pH of the semi-finished product after pickling is 3.8-4.5 (outer layer) and 5.0-6.0 (inner layer).

The chromium treatment is performed using a chromium extract in the pickling bath used. The consumption of chromium tanning agent is 0.4-0.5% by weight of 8 65449 years. Titanium tanning is performed using a fresh bath in the presence of phenol oligomers dispersed in lignosulfonic acids and is used at 2.5-5.0% by weight per year. The other steps are performed as described above.

Lactic acid, aluminum alum and the condensation product of synthetic fatty acids with triethanolamine are added when tanning, descaling and pickling hides or descaling and pickling hides, 0,5 to 2% by weight -% of years. These additives improve the quality of the leather; in particular, they increase the abrasion resistance of the leather and reduce its water absorption. After tanning, the semi-finished leather product is treated in a drum with Nairit latex, which is used in an amount of 1-6% by weight per year, based on the dry matter.

Example 1

Preparation of titanium tanning agent Use a 1 000 l solution of titanium ferric ferrosulphate having a composition of g / l: TiO2 to 100, H2SO4 to 300, FeO to 15 and obtained by extracting the cake. To this solution is added a sulfuric acid solution containing 100 g / l of peroxytitanium complex, calculated as TiO2 to a residual content of 0.01 g / l of TiO2, followed by precipitation of the salt by adding ammonium sulfate and sulfuric acid to the solution of free sulfuric acid and to a total ammonium sulphate content of 500 g / l. From the solutions, a double sulphate of titanyl and ammonium is precipitated in the form of the monohydrate (NH4) 2TiO (SO4) 2.H2O. The salt precipitation is 97% calculated for TiO2.

The precipitate is filtered off, washed with a solution containing 300 g / l H2SO4 and 200 g / l (NH4) 2SO4 and using 0.3 m3. The precipitate is then treated with a solution containing 400 g / l of ammonium sulphate; 0.25 m of solution is used. The yield of the final product is 480 kg. It contains, by weight: TiO 2 to 20; SO3 - 46; (NH4) 20-16; Fe 2 O 3 - 0.045; insoluble residue - 0.25; the rest being moisture.

Example 2

A volume of 1 000 l of titanium-ferriferro-sulfuric acid solution is used; it has the following composition, g / l: TiO 2 - 120, H 2 SO 4 - 400, 9 65449

FeO - 20. To this solution is added a sulfuric acid solution containing 100 g / l of peroxy-titanium complex. calculated as titanium dioxide, to a residual content of 2 g / l in solution calculated as TiCl2. The precipitation of the salt is carried out by adding ammonium sulphate until it is 80% calculated as titanium dioxide. The total content of free ammonium sulphate and free sulfuric acid is 400 g / l. The precipitated salt is separated off and washed with a solution containing 400 g / l of ammonium sulphate, used at 0.5 ml. 480 kg of salt are obtained. It contains, by weight:

TiO2 - 20; SO3 - 47; (NH4) 20-17; Fe ^^ “0/04; insoluble residue - 0.3 with the remainder being moisture.

After separation of the titanium double salt, the filtrate and washings are combined (yield 1,170 l) and ammonium sulphate is added to a total ammonium sulphate and sulfuric acid content of 600 g / l to ensure post-precipitation of the salt. The degree of precipitation of titanium is 15% of its initial content. The salt is filtered off to give 100 kg of final salt containing, by weight: TiO 2 to 18 and FejO 2 to 2.5. The salt thus prepared is returned to the starting titanium-ferric ferrous sulfate solution. The yield of the titanium double salt when using the recovery product after three returns is 97%.

Example 3

Method for tanning hides

The skins obtained from the horns of large horns (residual pieces, spillage waste, etc.) are placed in a drum, water at a temperature of 23-26 ° C is added to the liquid-to-leakage ratio 1.2 and then the sodium salt of disulfodinaphthylmethane is added 2% by weight of the skins.

The treatment time of the solids in this solution in a rotating drum is 1.5 hours, after which the titanium tanning agent prepared in Example 1 is added at 6% by weight of the soles, calculated as TiO2, and ammonium sulfate at 6% by weight of the soles. All of these ingredients are added in a dry state. Years are tanned by rotating the drum for 20 hours. The semi-finished leather thus obtained is then neutralized with sodium sulphite and urotropin, each of which is added at 3.5% by weight of the hides. Neutralization is stopped when the pH of the semi-finished product is 4.5. The semi-finished product of the bandage is washed with water and post-tanned with synthetic tanning agents using 17% tannins by weight.

ίο 6544 9

Synthetic tanning agents are those that are resistant to acidic media and arrunonium sulfate.

Post-tanning is performed with a water / leak ratio of 1.4 at 40 ° C for 2 days. The initial pH of the solution should not be less than 4. To reduce foaming in the post-partitioning, add 0.8 l of finishing paste or sulfonated whale fat together with a tanning agent.

The semi-finished product is then washed, the water is squeezed out, concentrated by dipping into a filler and greased. The following compounds are used for dipping: magnesium sulphate or ammonium sulphate in an amount of 5%, molasses in an amount of 8%. Lubrication is performed using solid lubricants. The other finishing steps are performed in the usual way. The leather thus prepared has the following characteristics: volume yield 102%, dry abrasion strength 200 r / min. 2 hours water absorption 45%.

Example 4

The descaled skins are placed in a drum, 26 ° C water is added to a water / flow ratio of 1.2, and phthalic anhydride is added in an amount of 2.0% by weight of the skins. Further treatment of the skins is carried out under the conditions described in Example 3 above. The characteristics of the obtained leather are similar to those obtained in Example 3.

Example 5

The treatment of the hides is carried out following the procedure described in Example 3, except that before the tanned hides are treated with aluminum alum in an amount of 3% by weight of the hides. The characteristics of the final leather are similar to those given in Example 3 above.

Example 6

The descaled hides are tanned under the conditions described in Example 3. Prior to tanning, the hides are treated with a mixture of aluminum alum and urotropin at a rate of 3.5% by weight of the hides, with a ratio of 2.5: 1 between the components of the mixture. The characteristics of the final leather are similar to those given in Example 3.

Example 7

Tanning of the descaled hides is carried out as in Example 3. Before tanning, the hides are treated with ammonium titanyl sulphate in an amount of 3% by weight of the hides. The characteristics of the final leather are similar to those given in Example 3.

Example 8

Prior to tanning, the pre-chromed hides are treated with phenolic oligomers dispersed in lignosulfonic acids in an amount of 3.5% by weight of the hides. The post-treatment of the semi-finished leather product is carried out under the conditions described in Example 3. The characteristics of the final leather are similar to those given in Example 3 above.

Example 9

The descaled hides from the cattle hides are placed in a drum, 26 ° C of water is added to a water / leach ratio of 1.2 and the titanium tanning agent prepared in Example 2 is added 6% by weight of hides TiCy, together with ammonium sulphate added 6% by weight of hides . At the same time, 0.8% by weight of lactic acid is added to the tanning bath. The duration of tanning in this solution is 22 hours. The resulting semi-finished leather product is then neutralized with sodium sulfite and urotropin, each used in an amount of 3.5% by weight of the hides. Neutralization is stopped when the pH of the semi-finished product is 4.5. The semi-finished product is then washed with water and post-tanned with synthetic tanning agents. Further processing of the semi-finished leather products is performed as described in Example 3 above. The use of lactic acid in the tanning process improves the quality of the final leather. The volume yield is 105%, the dry wear strength is 210 rpm and the 2-hour water absorption is 45%.

Example 10

The descaling of the descaled hides is carried out as described in Example 9 above, except that after neutralization the semi-finished leather product is treated with Nairit latex in an amount of 3% by weight of the hides, calculated on the dry matter. The duration of the treatment is 1 hour. Treatment of the semi-finished product with Nairit latex significantly improves the wear resistance of the final leather - 250 rpm.

12 65449

Example 11

The descaled and pickled hides are treated following the procedure described in Example 9 above, adding aluminum alum in an amount of 2% by weight of the hides. The characteristics of the final leather are similar to those obtained in Example 9.

Example 12

The descaled and pickled hides are treated following the procedure described in Example 9, adding aluminum alum in an amount of 2% by weight of the hides during tanning. After neutralization, the semi-finished leather product is treated with Nairit latex in an amount of 2% by weight of the solids, calculated on the dry matter. The characteristics of the final leather are similar to those obtained in Example 10 above.

Example 13

The descaled and pickled and chromed hides are treated following the procedure described in Example 9, adding a substance which is the condensation product of synthetic fatty acids with triethanolamine in an amount of 1.0% by weight of the hides during tanning. The characteristics of the final leather are similar to those obtained in Example 9 above.

Example 14

The descaled, pickled and chromed skins are treated as in Example 9, adding 1% of the condensation product of synthetic fatty acids with triethanolamine during tanning. After neutralization of the semi-finished leather product, it is treated with 2% Nairit latex based on the weight of the solids in the dry matter. The characteristics of the finished leather are similar to those specified in Example 10.

Leather made using a titanium tanning agent according to Examples 3-14 above has the following physical and mechanical characteristics: tensile strength 26-31 MPa; elongation 13-14%; wear resistance (abrasion resistance), dry 180-250 r / min.

wet 5.8-9.0 h / mm; 2 hour vcsi absorption 42-45% hydrothermal stability 90-100%.

13 65449

In addition, the leather made using the titanium tanning agent of the present invention has increased water resistance, perspiration resistance and mold resistance, and can be stored for a long time without deteriorating in quality.

Claims (12)

A process for the preparation of a titanium excipient starting from sulphate solutions containing titanium and ferriferous ions, by adding to the starting solution an oxidizing agent and then ammonium sulphate and sulfuric acid to precipitate diammonium titanyl bis (sulphate) monohydrate ) and stabilizes said double salt with ammonium sulfate, characterized in that to the starting sulfate solution is added as an oxidizing agent a sulfate solution of a peroxytitane complex so that the residual content of the complex in the starting solution will be 0.01-2 g / l calculated as titanium dioxide. 2. Process according to claim 1, characterized in that the double salt (NH 2) 2 10 (SO 2) is precipitated until it is formed in an amount of 75-85% calculated as titanium dioxide, then separated and the precipitated double salt is washed, the filtrate and the wash water are combined and the combination is treated with ammonium sulphate to post-precipitate the double salt, which is separated and returned to the starting solution. 3. A process for tanning of decalcified hides, characterized in that the hides are first treated with tanning activating agents, which consist of the sodium salt of disulfodinafethylmethane, phthalic anhydride, aluminum alum, aluminum alum together with urotropin, ammonium titanyl sulphate or phenol sulphonate sulphate treated with a titanium tanning agent prepared by adding a sulfate solution containing titanium and ferriferous ions, such as an oxidizing agent to a sulfate solution of a peroxite titanium complex so that the residual content of the complex in the starting solution will be 0.01-2 g / l; calculated as titanium dioxide, and then ammonium sulphate and sulfuric acid to precipitate diammonium titanyl bis (sulphate) monohydrate (NH 4) TiOtSO 4) 2 H 2 O preferably in an amount of 75-85%, calculated as titanium dioxide, and separated and washed. 4. A process according to claim 3, characterized in that, as the tanning activating agent, the sodium salt of disulfodinaphthylmethane is used in an amount of 1.5-2.5% by weight of the hides. ie 6 5 4 4 9 5. A process according to claim 3, characterized in that, as the tanning activating agent, phthalic anhydride is used in an amount of 1.2-2.2% by weight of the hides. 6. A process according to claim 3, characterized in that, as the tanning activating agent, aluminum alum is used in an amount from 1 to 3% by weight of the hides. 7. A process according to claim 3, characterized in that, as the tanning activating agent, a mixture of aluminum alum with urotropin is used in an amount of 1.8-5%, based on the weight of the hides, wherein the ratio of the components prevails between 0.5: 1 and 3.4: 1. 8. A process according to claim 3, characterized in that, as the digging activating agent, aramonium titany sulphate is used in an amount of 5-15% by weight of the hides. 9. A process according to claim 3, characterized in that, as the tanning activating agent, phenol oligomers dispersed in lignosulfonic acids are used in an amount of 2.5-5.0% by weight of the skins. Method according to claim 9, characterized in that the hides are chromium-plated prior to their treatment with phenol oligomers dispersed in lignosulfonic acids. 11. A method of tanning of decalcified hides or decalcified and grazed hides, or decalcified, grazed and chromed hides, characterized in that the tanning is performed using a titanium tanning agent prepared by adding a sulfate solution containing titanium - and ferriferous ions, such as oxidizing agents, a sulfate solution of a peroxitite complex such that the residue of the complex in the starting solution will be 0.01-2 g / l, calculated as titanium dioxide and then ammonium sulfate and sulfuric acid to precipitate diammonium titanylbis (sulfate) (NH ^) 2 ^ in ° (SO₂) of lactic acid, aluminum alum or condensation products of synthetic fatty acids with triethanolamine, and wherein the complexing agents are added in an amount of 0.5-2.0% calculated P * weight of hides na. Method according to claim 11, characterized in that the leather obtained from the tanning process is treated with a chloroprene rubber latex in an amount of 1-6% calculated on the dry weight of the hides.