US3927966A - Process of producing a fatliquoring chrome tanning agent, composition containing same and method of using same - Google Patents

Process of producing a fatliquoring chrome tanning agent, composition containing same and method of using same Download PDF

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US3927966A
US3927966A US521509A US52150974A US3927966A US 3927966 A US3927966 A US 3927966A US 521509 A US521509 A US 521509A US 52150974 A US52150974 A US 52150974A US 3927966 A US3927966 A US 3927966A
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fatliquoring
chrome
tanning
mixture
alkyl sulfonate
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Rolf Leberfinger
Heinz Matschkal
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Schill and Seilacher AG
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Schill and Seilacher AG
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    • CCHEMISTRY; METALLURGY
    • C14SKINS; HIDES; PELTS; LEATHER
    • C14CCHEMICAL TREATMENT OF HIDES, SKINS OR LEATHER, e.g. TANNING, IMPREGNATING, FINISHING; APPARATUS THEREFOR; COMPOSITIONS FOR TANNING
    • C14C3/00Tanning; Compositions for tanning
    • C14C3/02Chemical tanning
    • C14C3/04Mineral tanning
    • C14C3/06Mineral tanning using chromium compounds

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  • the present invention relates to a fatliquoring tanning agent and more particularly to a fatliquoring chrome-tanning agent, to a process of making such an agent, and to a method of using it in tanning leather.
  • Fatliquoring and/or oiling of leather after tanning serves to impart to leather a soft and flexible feel. Fatliquoring of leather is carried out usually with aqueous emulsions of fats or oils while the leather is still wet. Subsequently to the tanning process the leather is treated for this purpose in a rotating drum with 2% to (calculated for the so-called sammied or shaved weight of the leather) of a water-soluble fatliquoring agent emulsified in 100% to 200% of water at 20 C. to 50 C. for 30 minutes to 60 minutes.
  • Absorption of the fat or oil emulsion and incorporation into the leather is due to the fact that the emulsifier or the emulsifying portion of the emulsion is bound by polar groups of the leather and thus is withdrawn from the emulsion.
  • the emulsion breaks and becomes deemulsified and the hydrophobic, emulsified, water-soluble fat or oil component is deposited on the leather fiber and covers or envelopes the same.
  • this covering or enveloping prevents the leather fibers to stick together.
  • said covering or envelope decreases the frictional resistance at the fiber surface and thus prevents mechanical damage of the leather fiber on exposing the leather to stress.
  • optimum tensile strength properties of the leather are achieved.
  • fatliquoring agents which emulsify in water in an anion-active manner. Fatliquoring, most frequently, is effected subsequently to dyeing the leather.
  • anion-active emulsifying fatliquoring agents there are also used cationactive or non-ionogenic emulsifying fatliquoring agents in order to achieve certain specific effects. However, such agents are used only to a small extent.
  • Suitable anion-active fatliquoring agents are, for instance, sulfated oils and fats of vegetable or animal origin, sulfated or sulfited fish or sperm oils, and also alkyl sulfonates produced by saponifying alkyl sulfochlorides.
  • Cation-active emulsifying fatliquoring agents are preparations based on salts of alkylamines or quaternary alkylammonium salts in combination with hydrophobic, nonpolar fats and oils of biological origin as well as fatlike compounds of non-biological origin.
  • Nonionogenic emulsifying fatliquoring agents are agents based on ethoxylated fatty alcohols, fatty acids, or alkylphenols.
  • Partial or complete fatliquoring can be carried out not only subsequently to the tanning process and especially subsequently to chrome-tanning but also during the tanning process. Proceeding in this way is effected for reasons of economy or in order to impart to the leather an improved re-wetting ability if it is to be subjected to intermediate drying. If the leather were not exposed to the action of a fatliquoring agent before drying, it would not be possible to rehydrate the dried leather as this is required for dyeing the same and for subjecting it to subsequent finishing treatments.
  • the sulfited train oils which at present are preferably used for this purpose have the disadvantage that they are stable against light only to a certain extent and that they cause yellowing of the leather. They are also frequently responsible for formation of loose grain.
  • the sulfited sperm oils which do not have these disadvantages, are too expensive due to the scarcity of their raw material, and the cation-active or nonionogenic agent used alone do not produce the desired effect.
  • Another object of the present invention is to provide a process of producing such a fatliquoring chrome-tanning agent.
  • a further object of the present invention is to use such a fatliquoring chrome-tanning agent for tanning and fatliquoring unhaired, delimed, split or unsplit, bated, and pickled skins, hides, or pelts.
  • Still another object of the present invention is to use such fatliquoring chrome-tanning agents for re-tanning and fatliquoring of chrome-tanning skins, hides, or pelts.
  • the present invention is concerned with the surprising usefulness of alkyl sulfonates which, per se, are not stable against chrome-tanning salts, as fatliquoring agents which can be applied to the leather during chrome-tanning or retanning.
  • emulsions of said alkyl sulfonates are mixed with chromium (III) sulfate solutions and the mixture is atomized and spraydried to a powder.
  • the alkyl sulfonates may contain up to 40% of paraffin oils and other neutral oils calculated for the active compound. If the alkyl sulfonates contain oily paraffin components, they alone cannot be atomized and spray-dried to a powder.
  • the spray-dried products of mixtures of alkyl sulfonate emulsions and chromium sulfate solutions are completely soluble in water and do not cause separation of an oily deposit which is formed if the mixture of the alkyl sulfonate emulsion and chromium sulfate solution were not spray-dried.
  • the resulting spraydried mixture has tanning as well as fatliquoring properties and yields chrome leather which is resistant to boiling and which dries reversibly without losing its soft feel.
  • a fatliquoring chrome-tanning agent which has been obtained in a form of a powder by spray-drying a mixture consisting of an alkyl sulfonate emulsion and a chromium sulfate solution.
  • Solutions of cation-active emulsifiers and anion-active emulsifiers, the latter being based on fatty alcohol polyglycol ether sulfates with 4 moles of ehtylene oxide can be added thereto and can be atomized and spray-dried in mixture therewith.
  • Such spray-dried powders are used according to the present invention for simultaneous tannning and fat-liquoring or, respectively, for simultaneous re-tanning and fatliquoring.
  • alkyl sulfonates and the fatty alcohol polyglycol ether sulfates are bound as a complex to the chromium atom of the chromium sulfate under the conditions of spray-drying.
  • a chromium alkyl sulfonato complex compound or, respectively, a chromium fatty alcohol polyglycol ether sulfato complex compound are formed.
  • the salts of paraffin sulfonic acids are main components of the mixture in addition to the chromium sulfate and the resulting products are stable in emulsion form against electrolytes even without the addition of nonionogenic emulsifiers of the type of high-molecular ethoxylated alkyl phenols or fatty alcohols as they are mentioned in said German Published application No. 2,134,070, provided a mixture of chromium sulfate and alkyl sulfonate solutions as they are employed according to the present invention are heated and subsequently atomized and spray-dried to a powder.
  • the fatliquoring chrome-tanning agents are obtained by heating a chromium sulfate solution of a basicity up to 50% and preferably of about 33% in mixture with an alkyl sulfonate solution to a temperature between about 40 C. and about 180 C., if required, under pressure, for about 45 minutes to about 90 minutes and by removing the water from the heated mixture by spray-drying.
  • cation-active emulsifiers or anion-active emulsifiers the latter based on fatty alcohol polyglycol ether sulfates with, preferably, four moles of ethylene oxide may be added to the mixture.
  • the mixture of components to be spray-dried contains between about 15% and about 65% of chromium sulfate corresponding to about 3.8% and about 17% of chromium trioxide, preferably between 55% and 60%;
  • compositions of lower or higher concentration are rather uneconomical or can be prepared technically with difficulty only.
  • the proportion in which the solutions or, respectively, emulsions of chromium sulfate, the alkyl sulfonate which may contain certain amounts of paraffins and other neutral oils, and, if desired, the fatty alcohol polyglycol ether sulfate or the cation-active emulsifier are mixed, is selected so that the resulting spray-dried produce contains between about 93.0% and about 53.0% of chromium sulfate corresponding to between about 24.0% and about 14.0%, preferably between 23% and 20% of chromium trioxide;
  • paraffin oils which can be present in the alkyl sulfonate, or other neutral oils of biological or non-biological origin;
  • fatty alcohol polyglycol ether sulfate between 0% and about 5.0% of a fatty alcohol polyglycol ether sulfate or of a cation-active emulsifier.
  • Suitable alkyl sulfonates are, for instance, the saponification products of alkyl sulfochlorides with at least 8 carbon atoms and preferably with 10 to 18 carbon atoms in their alkyl moiety.
  • the alkyl sulfochlorides or, respectively, their saponification products can contain paraffin oils and other neutral oils with at least 8 carbon atoms in an amount up to 40%.
  • the leather is fatliquored at the same time during chrome-tanning.
  • chrome-tanned leather according to the present invention can be rehydrated readily and without difficulty after importing the tanned leather in the dry state and can then be further processed.
  • wet-blues are tanned with a chrome-tanning agent according to the present invention, there is no danger of faulty further processing and the quality of the leather is not impaired if such wet-blues are caused to dry or to partly dry due to improper storage or handling during shipping.
  • EXAMPLE 1 parts, by weight, of chromium sulfate of a basicity of 33% are dissolved in 160 parts, by weight, of water of 40 C. and are then emulsified by the addition of parts, by weight, of an aqueous alkyl sulfonate solution containing 40% of alkyl sulfonates with 10 to 18 carbon atoms in their alkyl moiety,
  • the emulsion is heated for about 1 hour to 90 C. and is then atomized in a disc-type spray-drying device at an entrance temperature for the drying air of 180 C. and with a disc speed of 18,000 revolutions per minute.
  • a pulverulent, water-soluble tanning and fatliquoring composition is obtained.
  • EXAMPLE 2 80 parts, by weight, of chromium sulfate with a basicity of 33% are dissolved in i 160 parts, by weight, of water of 40 C. and are emulsified with 60 parts, by weight, of an alkyl sulfonate solution of the composition given in Example 1. The resulting emulsion is heated and atomized as described in Example 1 to yield a pulverulent tanning and fatliquoring composition according to the present invention.
  • EXAMPLE 3 80 parts, by weight, of chromium sulfate of a basicity of 33% are dissolved in 160 parts, by weight, of water of 40 C. and are emulsified with 60 parts, by weight, of the alkyl sulfonate solution of Example 1 together with parts, by weight, of a aqueous solution of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
  • the resulting emulsion is heated and atomized as described in Example 1.
  • EXAMPLE 4 80 parts, by weight, of chromium sulfate with a basicity of 33% are dissolved in 160 parts, by weight, of water of C. and are emulsitied with 60 parts, by weight, of an alkyl sulfonate solution of the composition given in Example 1, together with 6 parts, by weight, of a cation-active emulsifier dissolved in 14 parts, by weight, of water.
  • the emulsion is heated and spray-dried as described in Example 1.
  • EXAMPLE 5 80 parts, by weight, of chromium sulfate of a basicity of 33% are dissolved in 160 parts, by weight, of water of 14 C. and are emulsified with 16 parts, by weight, of an aqueous alkyl sulfonate solution consisting of 35% of alkyl sulfonates with 10 to 18 carbon atoms in the alkyl moiety,
  • alkali metal sulfate and ammonium sulfate as they are obtained by saponifying the corresponding alkyl sulfonylchlorides and 29% of water together with 10 parts, by weight, of a 30% aqueous solution of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
  • the resulting emulsion is heated and spray-dried as described in Example 1.
  • EXAMPLE 6 parts, by weight, of chromium sulfate with a basicity of 33% are dissolved in 160 parts, by weight, of water of 40 C. and are emulsified with 60 parts, by weight, of an alkyl sulfonate solution of the composition described in Example 5 together with 20 parts, by weight, of a 30% aqueous solution of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
  • the resulting emulsion is heated and spray-dried as described in Example 1.
  • EXAMPLE 7 80 parts, by weight, of chromium sulfate with a basicity of 33% are dissolved in 160 parts, by weight, of water of 40 C. and the solution is emulsified by means of 60 parts, by weight, of an alkyl sulfonate solution of the composition given in Example 5 together with 6 parts, by weight, of a cation-active emulsifier dissolved in 14 parts, by weight, of water.
  • the resulting emulsion is heated and spray-dried as described in Example 1.
  • EXAMPLE A The limed, bated, and pickled, unsplit cowhide is chrome-tanned with the composition described in Example 1 in the following manner. The percentages refer to the weight of the hides:
  • the hides are chrome-tanned for minutes.
  • a solution of 1.0% of sodium formate and 1.5% of sodium bicarbonate dissolved in 25.0% of water is added to the tanned hides in 3 portions at intervals of 10 minutes each. Tannage is carried out for 15 hours 7 over night whereby the drum is rotated every 15 minutes.
  • the pH of the hides is about 3.8.
  • the tanned leather is split, folded, neutralized, retanned, dyed and, if required, re-oiled.
  • it is first dried to dry-blues.
  • the dry-blues can be re-wet at a later time by treating them with 800.0% of water calculated for the dry weight of the leather and 2.0% of 25% ammonia within 60 minutes and can be further processed and finished in the usual manner.
  • the leather obtained as described hereinabove is of good quality and meets all the conventional requirements. In addition thereto, such leather is only slightly extractable and has a good re-wetting capacity if it is subjected to intermediate drying before dyeing.
  • the leather obtained according to Example B is of excellent quality and meets all the conventional requirements.
  • anion-active emulsifiers there are preferably used anion-active alkyl sulfonates and the ethoxylated fatty alcohol sulfates as they are known to the art as highly effective and extensively used detergents and surfactants.
  • cation-active emulsifiers as added in Examples 4 and 7 there may preferably be employed salts of higher alkylamines and quaternary alkyl ammonium salts as they are also known to the art.
  • alkali metal and ammonium salts are present in the alkyl sulfonates when they are obtained by saponification with alkali metal hydroxides and/or ammonia, whereby alkali metal and/or ammonium salts are formed as by-products. It is, however, also possible to use alkyl sulfonates which are substantially free of such alkali metal and/or ammonium salts. The following example illustrates such a composition which is free of such salts.
  • the emulsion is heated for about 1 hour to 90 C. and is then atomized in a disc-type spray-drying device at an entrance temperature for the drying air of C. and with a disc speed of 18,000 revolutions per minute.
  • a pulverulent, water-soluble tanning and fat-liquoring composition is obtained.
  • the mixture of the aqueous solutions contains between about 15% and about 65% of chromium sulfate, corresponding to about 3.8% and about 17% of chromium trioxide, and between about 2% and about 25% of an alkyl sulfonate.
  • alkyl sulfonate solution additionally contains a paraffinic hydrocarbon with at least 8 carbon atoms.
  • alkyl sulfonate is an alkyl sulfonate with to 18 carbon atoms in the alkyl moiety.
  • a fatliquoring chrome-tanning agent in powder form said agent containing between about 93.0% and about 53.0% of chromium sulfate, corresponding to about 24% to about 14.0% of chromium trioxide and between about 6.0% and about 23.0% of an alkyl sulfonate, the alkyl moiety of said alkyl sulfonate having at least 8 carbon atoms.
  • the fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 12.0% of an oil selected from the group consisting of a paraffin oil with at least 8 carbon atoms and a neutral oil.
  • the fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 5% of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
  • the fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 5% of a cationactive emulsifier.
  • the fatliquoring chrome-tanning agent of claim 12 additionally containing between about 1% and about 7% alkali metal and ammonium salts.

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  • General Chemical & Material Sciences (AREA)
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Abstract

The fatliquoring chrome-tanning agent of this invention is composed of a spray-dried powder of a mixture of chromium sulfate and a higher molecular alkyl sulfonate which may contain paraffinic hydrocarbons, cation-active emulsifiers and/or anionactive fatty alcohol polyglycol ether sulfates. The powder can be used for simultaneous chrome-tanning and fatliquoring or for simultaneous retanning and oiling.

Description

United States Patent Leberfinger et al.
[ Dec. 23, 1975 PROCESS OF PRODUCING A FATLIQUORING CHROME TANNING AGENT, COMPOSITION CONTAINING SAME AND METHOD OF USING SAME Inventors: Rolf Leberfinger, Holzgerlingen;
Heinz Matschkal, Gaertringen, both of Assignee: Schill & Seilacher, Boeblingen,
Germany Filed: Nov. 6, 1974 Appl. No.: 521,509
Foreign Application Priority Data Nov. 7, 1973 Germany 2355503 US. Cl. 8/94.2; 8/9426; 8/9427 Int. Cl. C14C 5/00; C14C 3/04; C14C 3/06 Field of Search 8/94.2, 94.26, 94.27
References Cited UNITED STATES PATENTS 9/1957 Perrin 8/9427 FOREIGN PATENTS OR APPLICATIONS 310,834 l/l956 Switzerland 187,225 10/1956 Austria Primary Examiner-Joseph L. Schofer Assistant Examiner-A. L. Clingman Attorney, Agent, or FirmErich M. H. Radde 18 Claims, No Drawings PROCESS OF PRODUCING A FATLIQUORING CHROME TANNING AGENT, COMPOSITION CONTAINING SAME AND METHOD OF USING SAME BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fatliquoring tanning agent and more particularly to a fatliquoring chrome-tanning agent, to a process of making such an agent, and to a method of using it in tanning leather.
2. Description of the Prior Art Fatliquoring and/or oiling of leather after tanning serves to impart to leather a soft and flexible feel. Fatliquoring of leather is carried out usually with aqueous emulsions of fats or oils while the leather is still wet. Subsequently to the tanning process the leather is treated for this purpose in a rotating drum with 2% to (calculated for the so-called sammied or shaved weight of the leather) of a water-soluble fatliquoring agent emulsified in 100% to 200% of water at 20 C. to 50 C. for 30 minutes to 60 minutes. Absorption of the fat or oil emulsion and incorporation into the leather is due to the fact that the emulsifier or the emulsifying portion of the emulsion is bound by polar groups of the leather and thus is withdrawn from the emulsion. As a result thereof the emulsion breaks and becomes deemulsified and the hydrophobic, emulsified, water-soluble fat or oil component is deposited on the leather fiber and covers or envelopes the same. On drying of the leather, this covering or enveloping prevents the leather fibers to stick together. At the same time, said covering or envelope decreases the frictional resistance at the fiber surface and thus prevents mechanical damage of the leather fiber on exposing the leather to stress. As a result thereof optimum tensile strength properties of the leather are achieved.
ln general fatliquoring is carried out mainly by means of so-called fatliquoring agents which emulsify in water in an anion-active manner. Fatliquoring, most frequently, is effected subsequently to dyeing the leather. In place of, or in addition to, the anion-active emulsifying fatliquoring agents, there are also used cationactive or non-ionogenic emulsifying fatliquoring agents in order to achieve certain specific effects. However, such agents are used only to a small extent.
Suitable anion-active fatliquoring agents are, for instance, sulfated oils and fats of vegetable or animal origin, sulfated or sulfited fish or sperm oils, and also alkyl sulfonates produced by saponifying alkyl sulfochlorides.
Cation-active emulsifying fatliquoring agents are preparations based on salts of alkylamines or quaternary alkylammonium salts in combination with hydrophobic, nonpolar fats and oils of biological origin as well as fatlike compounds of non-biological origin.
Nonionogenic emulsifying fatliquoring agents are agents based on ethoxylated fatty alcohols, fatty acids, or alkylphenols.
Partial or complete fatliquoring can be carried out not only subsequently to the tanning process and especially subsequently to chrome-tanning but also during the tanning process. Proceeding in this way is effected for reasons of economy or in order to impart to the leather an improved re-wetting ability if it is to be subjected to intermediate drying. If the leather were not exposed to the action of a fatliquoring agent before drying, it would not be possible to rehydrate the dried leather as this is required for dyeing the same and for subjecting it to subsequent finishing treatments.
Heretofore there have been used for this purpose 5 only fatliquoring agents of the nonionogenic or cationactive emulsifier type or of the sulfited train oil and sperm oil type, because only emulsions of such types are stable enough against the chrome-tanning salts.
The sulfited train oils which at present are preferably used for this purpose, however, have the disadvantage that they are stable against light only to a certain extent and that they cause yellowing of the leather. They are also frequently responsible for formation of loose grain. The sulfited sperm oils which do not have these disadvantages, are too expensive due to the scarcity of their raw material, and the cation-active or nonionogenic agent used alone do not produce the desired effect.
The above mentioned sulfated oils and fats as well as products based on synthetic alkyl sulfonates are not suitable for fatliquoring the leather during chrome-tanning because their emulsions are not stable against chrome-tanning salts.
SUMMARY OF THE INVENTION It is one object of the present invention to provide a fatliquoring chrome-tanning agent which does not have the disadvantages of the fatliquoring agents used heretofore in chrome-tanning.
Another object of the present invention is to provide a process of producing such a fatliquoring chrome-tanning agent.
A further object of the present invention is to use such a fatliquoring chrome-tanning agent for tanning and fatliquoring unhaired, delimed, split or unsplit, bated, and pickled skins, hides, or pelts.
Still another object of the present invention is to use such fatliquoring chrome-tanning agents for re-tanning and fatliquoring of chrome-tanning skins, hides, or pelts.
Other objects of the present invention and advantageous features thereof will become apparent as the description proceeds.
In principle the present invention is concerned with the surprising usefulness of alkyl sulfonates which, per se, are not stable against chrome-tanning salts, as fatliquoring agents which can be applied to the leather during chrome-tanning or retanning. For this purpose, emulsions of said alkyl sulfonates are mixed with chromium (III) sulfate solutions and the mixture is atomized and spraydried to a powder. The alkyl sulfonates may contain up to 40% of paraffin oils and other neutral oils calculated for the active compound. If the alkyl sulfonates contain oily paraffin components, they alone cannot be atomized and spray-dried to a powder.
The spray-dried products of mixtures of alkyl sulfonate emulsions and chromium sulfate solutions are completely soluble in water and do not cause separation of an oily deposit which is formed if the mixture of the alkyl sulfonate emulsion and chromium sulfate solution were not spray-dried. The resulting spraydried mixture has tanning as well as fatliquoring properties and yields chrome leather which is resistant to boiling and which dries reversibly without losing its soft feel.
Thus it is an important characteristic feature of the present invention to produce and use a fatliquoring chrome-tanning agent which has been obtained in a form of a powder by spray-drying a mixture consisting of an alkyl sulfonate emulsion and a chromium sulfate solution. Solutions of cation-active emulsifiers and anion-active emulsifiers, the latter being based on fatty alcohol polyglycol ether sulfates with 4 moles of ehtylene oxide, can be added thereto and can be atomized and spray-dried in mixture therewith. Such spray-dried powders are used according to the present invention for simultaneous tannning and fat-liquoring or, respectively, for simultaneous re-tanning and fatliquoring.
It can be assumed that the alkyl sulfonates and the fatty alcohol polyglycol ether sulfates are bound as a complex to the chromium atom of the chromium sulfate under the conditions of spray-drying. As a result thereof a chromium alkyl sulfonato complex compound or, respectively, a chromium fatty alcohol polyglycol ether sulfato complex compound are formed.
In German Published application No. 2,134,070 it has been suggested to mix chromium sulfate with chloro paraffins, if desired, with the addition of small amounts of paraffin sulfonic acids or their salts. However, it is pointed out in said application that, only when using at the same time high molecular ethoxylated emulsifiers, there are obtained mixtures which yield stable emulsions in spite of their high electrolyte content.
In contrast thereto according to the present invention the salts of paraffin sulfonic acids are main components of the mixture in addition to the chromium sulfate and the resulting products are stable in emulsion form against electrolytes even without the addition of nonionogenic emulsifiers of the type of high-molecular ethoxylated alkyl phenols or fatty alcohols as they are mentioned in said German Published application No. 2,134,070, provided a mixture of chromium sulfate and alkyl sulfonate solutions as they are employed according to the present invention are heated and subsequently atomized and spray-dried to a powder.
According to the process of the present invention the fatliquoring chrome-tanning agents are obtained by heating a chromium sulfate solution of a basicity up to 50% and preferably of about 33% in mixture with an alkyl sulfonate solution to a temperature between about 40 C. and about 180 C., if required, under pressure, for about 45 minutes to about 90 minutes and by removing the water from the heated mixture by spray-drying. If desired, cation-active emulsifiers or anion-active emulsifiers, the latter based on fatty alcohol polyglycol ether sulfates with, preferably, four moles of ethylene oxide may be added to the mixture.
The mixture of components to be spray-dried contains between about 15% and about 65% of chromium sulfate corresponding to about 3.8% and about 17% of chromium trioxide, preferably between 55% and 60%;
between about 2% and about 25%, preferably between and of an alkyl sulfonate;
between 0% and about 5% of a fatty alcohol polyglycol ether sulfate or of a cation-active emulsifier; and
between about 83% and about 20% of water.
It is, of course, also possible to use compositions of lower or higher concentration as given above. Such composition, however, are rather uneconomical or can be prepared technically with difficulty only.
The proportion in which the solutions or, respectively, emulsions of chromium sulfate, the alkyl sulfonate which may contain certain amounts of paraffins and other neutral oils, and, if desired, the fatty alcohol polyglycol ether sulfate or the cation-active emulsifier are mixed, is selected so that the resulting spray-dried produce contains between about 93.0% and about 53.0% of chromium sulfate corresponding to between about 24.0% and about 14.0%, preferably between 23% and 20% of chromium trioxide;
between about 6.0% and about 23.0%, preferably between 6% and 15%, of an alkyl sulfonate;
between 0% and about 12.0%, preferably between 6% and 12%, of paraffin oils which can be present in the alkyl sulfonate, or other neutral oils of biological or non-biological origin;
between about 1% and about 7% of alkali metal and ammonium salts; and
between 0% and about 5.0% of a fatty alcohol polyglycol ether sulfate or of a cation-active emulsifier.
Suitable alkyl sulfonates are, for instance, the saponification products of alkyl sulfochlorides with at least 8 carbon atoms and preferably with 10 to 18 carbon atoms in their alkyl moiety. The alkyl sulfochlorides or, respectively, their saponification products can contain paraffin oils and other neutral oils with at least 8 carbon atoms in an amount up to 40%.
The advantages achieved by using a chrome-tanning and fatliquoring agent according to the present invention are as follows:
a. The leather is fatliquored at the same time during chrome-tanning.
b. It is possible to use during chrome-tanning or chrome-retanning with the product according to the present invention fatliquoring agents based on alkyl sulfonates which usually are not resistant to chromium-tanning salts.
c. Leather which has been treated with the products according to the present invention is distinguished by its excellent fat-binding capacity and low extractibility as well as by d. an excellent re-wetting capacity after drying.
In view of the last mentioned property it is possible to import chrome leather from the countries of origin of the skins or hides in the form of dry-blues, i.e. in dry condition and not in the form of wet-blues in wet condition provided such leather has been tanned with the chrome-tanning agents according to the present invention. Chrome-tanned leather according to the present invention can be rehydrated readily and without difficulty after importing the tanned leather in the dry state and can then be further processed. If wet-blues are tanned with a chrome-tanning agent according to the present invention, there is no danger of faulty further processing and the quality of the leather is not impaired if such wet-blues are caused to dry or to partly dry due to improper storage or handling during shipping.
Furthermore, the danger of mold formation is considerably reduced.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The following examples serve to illustrate the prepartion of tanning compositions according to the present invention as well as their use in tanning, without, however, being limited thereto.
EXAMPLE 1 parts, by weight, of chromium sulfate of a basicity of 33% are dissolved in 160 parts, by weight, of water of 40 C. and are then emulsified by the addition of parts, by weight, of an aqueous alkyl sulfonate solution containing 40% of alkyl sulfonates with 10 to 18 carbon atoms in their alkyl moiety,
18% of paraffins with 10 to 18 carbon atoms in their alkyl moiety,
14% of sodium sulfate and ammonium sulfate or chloride as they are obtained on producing the alkyl sulfonates by saponifying the alkyl sulfochlorides, and
28% of water.
The emulsion is heated for about 1 hour to 90 C. and is then atomized in a disc-type spray-drying device at an entrance temperature for the drying air of 180 C. and with a disc speed of 18,000 revolutions per minute.
A pulverulent, water-soluble tanning and fatliquoring composition is obtained.
EXAMPLE 2 80 parts, by weight, of chromium sulfate with a basicity of 33% are dissolved in i 160 parts, by weight, of water of 40 C. and are emulsified with 60 parts, by weight, of an alkyl sulfonate solution of the composition given in Example 1. The resulting emulsion is heated and atomized as described in Example 1 to yield a pulverulent tanning and fatliquoring composition according to the present invention.
EXAMPLE 3 80 parts, by weight, of chromium sulfate of a basicity of 33% are dissolved in 160 parts, by weight, of water of 40 C. and are emulsified with 60 parts, by weight, of the alkyl sulfonate solution of Example 1 together with parts, by weight, of a aqueous solution of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
The resulting emulsion is heated and atomized as described in Example 1.
EXAMPLE 4 80 parts, by weight, of chromium sulfate with a basicity of 33% are dissolved in 160 parts, by weight, of water of C. and are emulsitied with 60 parts, by weight, of an alkyl sulfonate solution of the composition given in Example 1, together with 6 parts, by weight, of a cation-active emulsifier dissolved in 14 parts, by weight, of water.
The emulsion is heated and spray-dried as described in Example 1.
EXAMPLE 5 80 parts, by weight, of chromium sulfate of a basicity of 33% are dissolved in 160 parts, by weight, of water of 14 C. and are emulsified with 16 parts, by weight, of an aqueous alkyl sulfonate solution consisting of 35% of alkyl sulfonates with 10 to 18 carbon atoms in the alkyl moiety,
25% of paraffin oils with 10 to 18 carbon atoms in their alkyl moiety or other neutral oils of biological or nonbiological origin,
11% of alkali metal sulfate and ammonium sulfate as they are obtained by saponifying the corresponding alkyl sulfonylchlorides and 29% of water together with 10 parts, by weight, of a 30% aqueous solution of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
The resulting emulsion is heated and spray-dried as described in Example 1.
EXAMPLE 6 parts, by weight, of chromium sulfate with a basicity of 33% are dissolved in 160 parts, by weight, of water of 40 C. and are emulsified with 60 parts, by weight, of an alkyl sulfonate solution of the composition described in Example 5 together with 20 parts, by weight, of a 30% aqueous solution of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
The resulting emulsion is heated and spray-dried as described in Example 1.
EXAMPLE 7 80 parts, by weight, of chromium sulfate with a basicity of 33% are dissolved in 160 parts, by weight, of water of 40 C. and the solution is emulsified by means of 60 parts, by weight, of an alkyl sulfonate solution of the composition given in Example 5 together with 6 parts, by weight, of a cation-active emulsifier dissolved in 14 parts, by weight, of water.
The resulting emulsion is heated and spray-dried as described in Example 1.
Of course, other chromium sulfate solutions of the required concentration and basicity as they can be prepared or obtained in another manner than described hereinabove, can be used in Examples 1 to 7 in place of the aqueous chromium sulfate solution of said examles. p The following examples describe the manner in which the spray-dried powders according to the present invention are used for simultaneous tanning and fat-liquoring of skins, hides, and pelts without, however, being limited thereto.
EXAMPLE A The limed, bated, and pickled, unsplit cowhide is chrome-tanned with the composition described in Example 1 in the following manner. The percentages refer to the weight of the hides:
60.0% of water of 30 C.
2.0% of sodium sulfate 17% of the composition described in Example 2, which is added in two equal portions, the second portion being added 30 minutes after the first portion has been added.
The hides are chrome-tanned for minutes.
A solution of 1.0% of sodium formate and 1.5% of sodium bicarbonate dissolved in 25.0% of water is added to the tanned hides in 3 portions at intervals of 10 minutes each. Tannage is carried out for 15 hours 7 over night whereby the drum is rotated every 15 minutes. The pH of the hides is about 3.8.
Then, there is added to the tanning float 200% of water of 35 C. and run for 30 minutes. After sammying, the tanned leather is split, folded, neutralized, retanned, dyed and, if required, re-oiled. Or, after treatment with the composition according to the present invention and after sammying, it is first dried to dry-blues. The dry-blues can be re-wet at a later time by treating them with 800.0% of water calculated for the dry weight of the leather and 2.0% of 25% ammonia within 60 minutes and can be further processed and finished in the usual manner.
The leather obtained as described hereinabove is of good quality and meets all the conventional requirements. In addition thereto, such leather is only slightly extractable and has a good re-wetting capacity if it is subjected to intermediate drying before dyeing.
EXAMPLE B Chrome-tanned and folded leather is re-tanned and fatliquored with the composition according to Example 3 of the present invention as described hereinafter, whereby the percent values given refer to the folding weight:
Washing: With 300.0% of water of 35 C. for
minutes.
Chrome-retanning: With 80.0% of water at 45 C.
and with 5.0% to 7.0% of the composition as described in Example 3.
The leather obtained according to Example B is of excellent quality and meets all the conventional requirements.
Of course, many changes and variations in the composition of the fatliquoring and chrome-tanning agents of the present invention, in the manner of their preparation, in the conditions of atomizing and spray-drying the solutions and/or emulsions of the components of said agents, in the concentration of the solutions used for chrome-tanning or re-tanning, in the temperature, duration, and other conditions of tanning or re-tanning, and the like may be made by those skilled in the art in accordance with the principles set forth herein and in the claims annexed thereto.
Thus, for instance, other amounts of chromium sulfate and the other components of the fatliquoring and chrome-tanning composition according to the present invention than those given in the aforesaid Examples 1 to 7 may be present in such compositions and other temperatures and spray-drying conditions may be employed for preparing the fatliquoring powders of the present invention. Likewise, chrome-tanning and retanning may be effected with other amounts and concentrations of the fatliquoring and chrome-tanning compositions according to the present invention than those given in Examples A and B.
As anion-active emulsifiers there are preferably used anion-active alkyl sulfonates and the ethoxylated fatty alcohol sulfates as they are known to the art as highly effective and extensively used detergents and surfactants.
As cation-active emulsifiers as added in Examples 4 and 7 there may preferably be employed salts of higher alkylamines and quaternary alkyl ammonium salts as they are also known to the art.
Usually the alkali metal and ammonium salts are present in the alkyl sulfonates when they are obtained by saponification with alkali metal hydroxides and/or ammonia, whereby alkali metal and/or ammonium salts are formed as by-products. It is, however, also possible to use alkyl sulfonates which are substantially free of such alkali metal and/or ammonium salts. The following example illustrates such a composition which is free of such salts.
EXAMPLE 7 parts, by weight, of chromium sulfate of a basicity of 33% are dissolved in parts, by weight, of water of 40 C. and are then emulsified by the addition of 15 parts, by weight of an aqueous alkyl sulfonate solution containing 47% of alkyl sulfonates with 10 to 18 carbon atoms in their alkyl moiety,
21% of paraffins with 10 to 18 carbon atoms in their alkyl moiety and 32% of water.
The emulsion is heated for about 1 hour to 90 C. and is then atomized in a disc-type spray-drying device at an entrance temperature for the drying air of C. and with a disc speed of 18,000 revolutions per minute.
A pulverulent, water-soluble tanning and fat-liquoring composition is obtained.
We claim:
1. In a process of producing a fatliquoring chrometanning agent, the steps which comprise a. heating an aqueous chromium sulfate solution in mixture with an aqueous solution of an alkyl sulfonate, the alkyl residue of which contains at least 8 carbon atoms, and
b. atomizing and spray-drying said mixture of solutions to a powder.
2. The process of claim 1, in which the mixture of the aqueous solutions contains between about 15% and about 65% of chromium sulfate, corresponding to about 3.8% and about 17% of chromium trioxide, and between about 2% and about 25% of an alkyl sulfonate.
3. The process of claim 1, in which the alkyl sulfonate solution additionally contains a paraffinic hydrocarbon with at least 8 carbon atoms.
4. The process of claim 1, in which the aqueous alkyl sulfonate solution additionally contains a neutral oil.
5. The process of claim 1, in which the mixture of solutions to be atomized additionally contains a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
6. The process of claim 1, in which the mixture of solutions to be atomized additionally contains a cationactive emulsifier.
7. The process of claim 2, in which the mixture of solutions to be atomized additionally contains a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
8. The process of claim 2, in which the mixture of solutions to be atomized additionally contains a cationactive emulsifier.
9. The process of claim 5, in which the fatty alcohol polyglycol ether sulfate is present in an amount up to about 5%.
10. The process of claim 6, in which the cationactive emulsifier is present in an amount up to about 5%.
11. The process of claim 1, in which the alkyl sulfonate is an alkyl sulfonate with to 18 carbon atoms in the alkyl moiety.
12. A fatliquoring chrome-tanning agent in powder form, said agent containing between about 93.0% and about 53.0% of chromium sulfate, corresponding to about 24% to about 14.0% of chromium trioxide and between about 6.0% and about 23.0% of an alkyl sulfonate, the alkyl moiety of said alkyl sulfonate having at least 8 carbon atoms.
13. The fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 12.0% of an oil selected from the group consisting of a paraffin oil with at least 8 carbon atoms and a neutral oil.
14. The fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 5% of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
15. The fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 5% of a cationactive emulsifier.
16. The fatliquoring chrome-tanning agent of claim 12 additionally containing between about 1% and about 7% alkali metal and ammonium salts.
17. In a process of simultaneously chrome-tanning and fatliquoring skins, hides, and the like, the step which comprises tanning skins, hides, and the like with the spray-dried product of claim 1.
18. In a process of simultaneously re-tanning and fatliquoring chrome-tanned skins, hides, and the like, the step which comprises re-tanning chrome-tanned skins, hides, and the like with the spray-dried process of claim 1.
UNITED STATES PATENT OFFICE CERTIFICATE OF CGRRECTION Patent No. 3,927,966 Dated December 23, 1975 lnventofls) ROLF LEBERFINGER and HEINZ MATSCHKAL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: 0
Column 3, lines 4 and 5: "ehty lene" should read ethylene 0 Column 3 line 64: "composition" should read compositions Column 4, line 4: "produce" should read product Column 10, line 8; Between "7%" and "alkali", the word of should be inserted a Signed and Sealed this thirteenth Day of April1976 [SEAL] AIIESI. O
RUTH C. MASON C. MARSHALL DANN Arresting Officer ('ummissitmcr uj'lareins and Trademarks

Claims (18)

1. IN A PROCESS OF PRODUCING A FATLIQUORING CHROME-TANNING AGENT, THE STEP WHICH COMPRISES A. HEATING AN AQUEOUS CHROMIUM SULFATE SOLUTION IN MIXTURE WITH AN AQUEOUS SOLUTION OF AN ALKYL SULFONATE, THE ALKYL RESIDUE OF WHICH CONTAINS AT LEAST 8 CARBON ATOMS, AND B. ATOMIZING AND SPRAY-DRYING SAID MIXTURE OF SOLUTIONS TO A POWDER.
2. The process of claim 1, in which the mixture of the aqueous solutions contains between about 15% and about 65% of chromium sulfate, corresponding to about 3.8% and about 17% of chromium trioxide, and between about 2% and about 25% of an alkyl sulfonate.
3. The process of claim 1, in which the alkyl sulfonate solution additionally contains a paraffinic hydrocarbon with at least 8 carbon atoms.
4. The process of claim 1, in which the aqueous alkyl sulfonate solution additionally contains a neutral oil.
5. The process of claim 1, in which the mixture of solutions to be atomized additionally contains a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
6. The process of claim 1, in which the mixture of solutions to be atomized additionally contains a cation-active emulsifier.
7. The process of claim 2, in which the mixture of solutions to be atomized additionally contains a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
8. The process of claim 2, in which the mixture of solutions to be atomized additionally contains a cation-active emulsifier.
9. The process of claim 5, in which the fatty alcohol polyglycol ether sulfate is present in an amount up to about 5%.
10. The process of claim 6, in which the cationactive emulsifier is present in an amount up to about 5%.
11. The process of claim 1, in which the alkyl sulfonate is an alkyl sulfonate with 10 to 18 carbon atoms in the alkyl moiety.
12. A FATLIQUORING CHROME-TANNING AGENT IN POWDER FORM, SAID AGENT CONTAINING BETWEEN ABOUT 93.0% AND ABOUT 53.0% OF CHROMIUM SULFATE, CORRESPONDING TO ABOUT 24% TO ABOUT 14.0% OF CHROMIUM TRIOXIDE AND BETWEEN ABOUT 6.0% AND ABOUT 23.0% OF AN ALKYL SULFONATE, THE ALKYL MOIETY OF SAID ALKYL SULFONATE HAVING AT LEAST 8 CARBON ATOMS.
13. The fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 12.0% of an oil selected from the group consisting of a paraffin oil with at least 8 carbon atoms and a neutral oil.
14. The fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 5% of a fatty alcohol polyglycol ether sulfate with 4 moles of ethylene oxide.
15. The fatliquoring chrome-tanning agent of claim 12 additionally containing up to about 5% of a cation-active emulsifier.
16. The fatliquoring chrome-tanning agent of claim 12 additionally containing between about 1% and about 7% alkali metal and ammonium salts.
17. In a process of simultaneously chrome-tanning and fatliquoring skins, hides, and the like, the step which comprises tanning skins, hides, anD the like with the spray-dried product of claim 1.
18. In a process of simultaneously re-tanning and fatliquoring chrome-tanned skins, hides, and the like, the step which comprises re-tanning chrome-tanned skins, hides, and the like with the spray-dried process of claim 1.
US521509A 1973-11-07 1974-11-06 Process of producing a fatliquoring chrome tanning agent, composition containing same and method of using same Expired - Lifetime US3927966A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4744794A (en) * 1984-05-24 1988-05-17 Henkel Kommanditgesellschaft Auf Aktien Leather fatliquoring agents combinable with tanning and retanning compositions
CN113429320A (en) * 2021-07-15 2021-09-24 老河口市天和科技有限公司 Preparation method of pentadecyl sulfonyl chloride and oil tanning agent containing pentadecyl sulfonyl chloride

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FR2670800B1 (en) * 1990-12-19 1994-05-20 Gaches Chimie Sa PROCESS FOR THE TREATMENT OF SKINS OR LEATHERS, TANNING AGENTS AND METHOD OF MANUFACTURE.

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2805117A (en) * 1953-09-08 1957-09-03 Diamond Alkali Co Method of preparing a tanning composition comprising basic chromic sulfate

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2805117A (en) * 1953-09-08 1957-09-03 Diamond Alkali Co Method of preparing a tanning composition comprising basic chromic sulfate

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4744794A (en) * 1984-05-24 1988-05-17 Henkel Kommanditgesellschaft Auf Aktien Leather fatliquoring agents combinable with tanning and retanning compositions
CN113429320A (en) * 2021-07-15 2021-09-24 老河口市天和科技有限公司 Preparation method of pentadecyl sulfonyl chloride and oil tanning agent containing pentadecyl sulfonyl chloride

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