US2328931A - Preparing sulphonated products - Google Patents

Description

Patented Sept. 7, 1943 PREPARING SULPHONATED PRODUCTS Karl T. Steik, Upper Montclair, N. J., assignor to National Oil Products Company, N. .L, a corporation of New Jersey Harrison,

No Drawing. Application June 17, 1939, Serial No. 279,678

8 Claims.

My invention isdirected to the production of sulphonated materials, and more particularly to the production of sulphonated fatty acids, fatty oils and fatty derivatives, by novel methods which yield these sulphonated materials in substantially.

method of sulphonation, as now carried out, is to treat the material with an excess of sulphonating.

reagent, such as sulphuric acid, chlorsulphonic acid, oleum, or similar suitable reagents; and when sulphonation has proceeded to the desired stage, to wash out the excess acid with Water,

generally in the presence of salts such as sodium chloride or sodium sulphate. This washing, however, cannot be carried out to the point where all excess acid is eliminated, because of the emulsifying properties of the sulphonated mass and because such washing, if excessive, considerably reduces the yield of sulphonated material. In addition, the washing operation also causes the formation of undesirable by-products, by hydrol ysis of the sulphonation mass, and must therefore be limited to the point where it still gives a good yield of sulphonated material not containing too high a proportion of these hydrolytic byproducts. For these reasons, the remainder of the excess acid is not eliminated by water washes, but is neutralized instead with aqueous solutions of alkalies such as potash, soda, ammonia, etc.

The aqueous solutions of the inorganic salts formed by this neutralization are then settled out of the sulphonated oil by allowing the mass to stand and separate into layers. During the neutralization process enough alkali is used so that part or all of the combined acid of the sulphonated oil is also neutralized. The extent of this neutralization of the sulphonated oil itself depends on the intended use of the oil, the pH of which can be varied to suit such use.

As pointed out before, the emulsifying properties of the sulphonated mass and the water-solubility imparted to it by sulphonation make for the retention in the sulphonated oil of substantial proportions of both water and inorganic salts, even after prolonged washing and standing. The sulphonated oils now produced are therefore relatively high in both water and inorganic salt content, the water content being about 18% and the inorganic salt content being about 1% and usually higher than this figure. In the case of oils with a very low combined SO: content the moisture may drop to 10%, but such oils are special products and are not being produced to any great extent; After the wash water has been drawn off the moisture content is raised to 25%, which is normal for commercial products. The retention of the salts in the sulphonated oil\ is, of course, helped by the presence of water in which they are in solution, and the salts thus retained are due both to neutralization of the excess mineral acid used for sulphonation and to. the washing of the crude sulphonation mass with aqueous salt solution.

The relatively high water and salt content of sulphonated fatty acids, fatty oils and fatty derivatives is undesirable and detrimental for various reasons. The presence of by-products of hydrolysis produced by water treatments is also undesirable for certain uses. The high water content of commercial products greatly reduces their range of application and adds to the difiiculty of their mixing with non-sulphonated oils 'or other substances with which they are incorporated for industrial uses.

The inorganic salt content reduces the stability of emulsions produced with the sulphonated oils,-and is often detrimental to the materials treated with these oils. By catalytic action, the salts also cause the oils to hydrolyze and to oxidize more rapidly and thereby considerably reduce their usefulness in various processes where these oils are employed, since it is generally necessary that the oils used in such materials as textiles, paper, leather, etc., for lubricating or finishing operations should show a minimum of oxidizability. The inorganic salts also considerably reduce the miscibility of sulphonated oils with other oils such as mineral oil and fatty oils.

The hydrolytic by-products, formed during water washing of the crude sulphonation mass to remove excess acid and part of the salts of the neutralization and also during standing of watercontaining sulphonated oils, give haziness to the finished oil, cause it to be unstable and to separate on storage, accelerate oxidation of the oil and have various detrimental affects on materials to which the oil is applied, by acting as oxidation catalysts, for example.

During the step of sulphonating fatty oils and derivative thereof by the treatment thereof with sulphuric acid or other sulphonating agents, condensation and polymerization of the fatty materials takes place. These reactions, which are induced by the catalytic properties of the sulphonating agent result in fatty materials of very high molecular weight, which, in turn, tend to interfere with the emulsifying efiiciency and otherwise deter from the desirable properties of sulphonated fatty materials.

My method is designed to eliminate the above and other drawbacks due to the presence of water,

salts, hydrolytic by-products, condensation and polymerization products in sulphonated fatty materials, and to prepare these materials in such a manner that these elements are either eliminated or present in such small proportion that they have none of the heretofore observed detrimental affects.

I have discovered that, by taking up the crude sulphonation mass in a suitable organic solvent or solvents before washing with water, I can neutralize the excess sulphonating agent with alkalies such as potash, soda, ammonia, etc., in the presence of the solvent and separate the inorganic salts of neutralization which precipitate out by settling, filtration, centrifuging or otherwise. The fatty condensation and polymerization products which are normally formed during sulphonation precipitate out of the solvent solution of the sulphonation mass and are removed along with the precipitated inorganic salts. The alkali used in neutralizing the excess acid may be added as a concentrated aqueous solution or dissolved in an organic solvent such as alcohol. After separation of the inorganic salts, condensation and polymerization products, the substantially alt-free solvent solution of the sulphonated material is distilled, preferably under vacuum, to eliminate the solvent and during this distillation, the bulk of the water present in the neutralizing medium or that formed by neutral ization of the acid also distills off with the solvent. The solvent is later dehydrated and reused for subsequent similar procedures. In order to eliminate excessive foaming, especially toward the end of distillation, agitation is desirable, particularly for pasty products like sulphonated tallow or castor oil. By this method a batch of sulphonated products can be'made in about six hours instead of thirty or more hours by the old method.

By "crude sulphonation mass as referred to in this specification and claims, I mean the mass obtained after treatment of the fatty acid, fatty oil or fatty derivative with a sulphonating reagent, prior to any other treatment with water or neutralizing agents.

The above described procedure yields a material which is substantially free of inorganic salts and water and which contains practically none of the hydrolytic by-products which are produced in substantial quantities by the water-washes of the usual sulphonation methods. Sulphonated oils produced according to the invention contain about .3% to 3.0% moisture and only traces of inorganic salts, i. e., up to about .l2%.

It will be understood that various modifications of my procedure will yield sulphonated material which is equally within the scope of my disclosure. For example, if hydrolytic by-prodnets are not detrimental for some purposes, it is possible to wash part of the excess acid contained in the crude sulphonation mass with water and then take up the mass in a solvent. 'The neutralization with alkali can also be carried out before the mass is taken up in the solvent with removal of the salts after addition of the neutralized mass to the solvent.

The precipitated salts can be removed from the solvent solution in stages, if desired, i. e., first in a concentrated solution and later in a more dilute solution. For the production of sulphonated oils which are substantially salt-free and water-free, however, we find it necessary to use a total volume of solvent which is at least equal to and preferably 3 to 4 times the volume of crude sulphonation mass which is being treated, whichever of the above methods is employed to form and remove the inorganic salts. This quantity of solvent is also necessary for the eflicient removal of water added through the sulphonating and neutralizing agents employed, and if the crude sulphonation mass has been water-washed prior to neutralization, an even larger volume of solvent may be needed to remove the additional water present.

Oils are subject to bacterial decomposition depending on the kind of bacteria with which the oil has been contaminated. The glycerides may be split and the glycerine oxidized to water and carbon dioxide, or the sulphur in the suphate group may be reduced to hydrogen sulphide.

Substantially anhydrous sulphonated fatty products as obtained by the described process are not subject to bacterial action. This fact is of enormous importance when considering the dimculty with which germs in an oil are killed by bacteriacides and that oils decomposed by bacteria are no longer satisfactory for the purposes for which they are intended.

Sulphonated oils are often used for blending with raw oils to make the mixtures emulsifiable. Substantially anhydrous and salt-free oils free of hydrolytic by-products, condensation and polymerization products, obtained by this method blend very easily to homogeneous, nonseparating emulsifiable mixtures. Blends are now possible that could not be made with sulphonated oils as they were known before this discovery.

In carrying out the process of the invention any suitable solvent of the type mentioned above may be employed, the following examples being illustrative of some of those which have been found suitable: ethyl alcohol, isopropyl alcohol, ethylene dichloride, trichlorethylene, petroleum ether, acetone, methyl ethyl ketone, methyl sperm, whale, tuna fish, etc. Animal oils: neatsfoot, beef tallow, bone, fat, horse fat, wool fat, mutton tallow, etc. In general, the process is applicable to all fatty acids, fatty esters and their derivatives which are capable of sulphonation through the presence of a hydroxyl group or a point of unsaturation. Sulphonated mono and diglycerides and fatty acids esterified with any mono or polyhydric alcohols may be produced according to this invention.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following examples which are given merely to further illustrate the invention and are not to be construed in a limiting sense, all parts given being by weight.

Example I 500 parts of olive oil and 150 parts of 66B. sulphuric acid were sulphonated at 20 C. for two hours. The crude sulphonation mass was then taken up in 1500 parts of ethyl alcohol and neutralized to a pH of 6.5-7.0 with 530 parts of a 15% solution of NaOH in methyl alcohol. After filtering ofi the salts, the solvent was distilled off in the usual way. The dry product contained 8.8% of organically combined S03, 1.0% moisture and a trace of salts.

Example II 500 parts of castor oil were sulphonated with 150 parts of 66 B. sulphuric acid at 35 C. The sulphonation mass was taken up in 1000 parts of ethyl alcohol and neutralized to a pH of 7.0-7.5 with 540 parts of a 17.5% solutionof NaOH in ethyl alcohol and finished as in Example I. The final product contained 6.98% of organically combined S03, 2.5% of moisture and trace of salts.

Example III 500 parts of sperm oil were sulphonated with 150 parts of 66 B. sulphuric acid at 20 C. The sulphonation mass was taken up in 1500 parts of isopropyl alcohol, neutralized with 410 parts of a 18.5% solution of NaOH in methyl alcohol. Finished as in Example I. The final product contained 7.72% of organically combined SO: and

1.0% of moisture.

Example IV 500 parts of tallow were sulphonated with 125 parts of 66 B. sulphuric acid at 40 C. The sulphonation mass was taken up in 1500 parts of ethyl alcohol and neutralized with 590 parts of a 15.2% solution of NaOH in methyl alcohol. Finished as in Example 1. Final product contained 2.6% of organically combined S03, 3.0% of moisture and 0.04% of inorganic salts.

Example V 500 parts of sperm oil were sulphonated with 150 parts of 66 B. sulphuric acid. The sulphonation mass was taken up with 1200 parts of ethylene dichloride. The oil was neutralized and finished as under Example III. The finished product contained 7.9% of organically combined SO: and 0.6% of moisture and only a trace of inorganic salts.

Example VI As an example of a marine oil 500 grams of cod oil were sulphonated with 133 grams of 66 B. sulphuric acid for two hours at a temperature of 8 C. to 20 C. The sulphonation mass was .taken up in 1500 c. c. of isopropyl alcohol and neutralized with 450 grams of a 15.5% solution of NaOH in methyl alcohol. The pH was 6.5. After standing overnight the precipitated salt was filtered off and then the alcohols were distilled oif from the solution in the usual way. The product had the following composition:

Organically combined SO: per cent 6.6

Acid value 220 Alkali per cent 0.27

Moisture "do"--. 1.0

Example VII As an example of sulphonated fatty acids 500 grams of oleic acid were sulphonated with 150 grams of 66 B. sulphuric acid for two hours. The temperature in the beginning of sulphonation was 6 C. and was gradually raised to 20 C. after all acid was added. The sulphonation mass was taken up in 1500 c. c. of isopropyl alcohol and neutralized to pH of 6.5 with a 15.5% solution of NaOH in methyl alcohol. The solution was allowed to stand overnight, the salts were filtered off and the alcohols distilled off in the usual way. The product had the following specifications:

Organically combined S03 per cent 8.6 Acid value 96.4 Alkali per cent 3.63 Water do 0.75 Inorganic salts Trace Example VIII Similar to Example VII except that the neutralization is carried out with a concentrated aqueous solution of NaOH instead of a methyl alcohol solution of NaOH. The pH values to which I the solutions of the sulphonation mass were neutralized are merely illustrative. According to the products desired, as determined by their uses. the pH range of neutralization may be from about pH 2.5 to pH 11.0, but since such oils may have new uses for which pH values may be different, I do not limit myself to the above range.

Example IX 20 lbs. of olive oil were sulphonated for 4 hours with 6 lbs. of 66 B. sulphuric acid at a temperature of 30 C. The crude sulphonation mass was taken up in lbs. of methyl ethyl ketone and 24 lbs. of a 15% solution of NaOH in ethyl alcohol was stirred into the olution. The sodium sulphate which precipitated out was filtered oil and the solvent was distilled from the filtrate under reduced pressure, leaving as a residue a sulphonated olive oil containing 1.0% water and 0.05% inorganic salt.

Example X 20 lbs. of olive oil were sulphonated as in Example IX. The crude'sulphonation mass was taken up in 50 lbs. methyl ethyl ketone and 7 lbs. of a 50% aqueous NaOH solution were added. The salt was filtered off and the solvent distilled under reduced pressure. The sul phonated olive oil produced in this manner contained approximately 1.5% H20 and 0.07% inorganic salt.

Example XI 20' lbs. of oleic acid were sulphonated for 4 hours with 6 lbs. of 66 B. sulphuric acid at 30 C. To the crude sulphonation mass were added 30 lbs. of a 15% solution of KOH in methyl alcohol and the mass was dropped into 60 lbs. of acetone. The salt which precipitated out was filtered off and the solvent distilled, leaving as a residue a sulphonated oleic acid containing 1.3% Water and 0.05% inorganic salt.

Example XII precipitated out was filtered off and the solvent distilled under reduced pressure. The residue consisted of a sulphonated neats-foot oil containing 2.5% H20 and'0.1% inorganic salt.

Example XIII The olive oil of Example IX was replaced by sperm oil to produce a sulphonated sperm oil which was substantially free of water, i. e., 2% or less, and which contained only a trace of inorganic salt.

. Example XIV 10 lbs. of isobutyl oleate were sulphonated with lbs. of 66 B. sulphuric acid for 5 hours at 25 C. The crude sulphonation mass was taken up in 5 lbs. of methyl ethyl ketone and neutralized with 11.5 lbs. of a 25% aqueous solution of KOH.

After neutralization, the mass was run into 25 lbs. of methyl ethyl ketone and the inorganic salts filtered off. The filtrate was distilled under reduced pressure, leaving a residue consisting of sulphonated isobutyl oleate containing 1.2% water and 0.12% inorganic salt.

Erample XV The methyl ethyl ketone of Example XIV was replaced by methyl propyl ketone. While the water and salt content of the sulphonated materials produced as described in the above examples was of the order of 1 to 3.0% for water and 0.01 to 0.12% for inorganic salts, it is readily understood that the volume of solvent and the number of operations can be varied to produce practically any desired water and inorganic salt content in the finished material.

I therefore use my process to bring down the water and inorganic saltcontent to the point where I have observed that the drawbacks of ordinary sulphonated fatty materials are eliminated. It was found that a water content of less than 3% and an inorganic salt content of less than 0.12% are the limits below which most of these already-mentioned drawbacks are eliminated; and all of the sulphonated fatty materials produced in the above examples, are, therefore, well suited for many uses where ordinary sulphonated materials cannot be satisfactorily employed because of the disadvantages inherent to such materials.

The crystallization of salts on the fibers which tenders textile materials and gives them a harsh feeling, cannot occur with my materials as it does with ordinary sulphonated products. The

low content of salts and water also prevents the increase in the rate of hydrolysis of the fatty esters, which'is characteristic of ordinary sulphonated oils. This hydrolysis of ordinary sulphonated products, both during their preparation and upon standing, leads to the formation of free fatty acids and oxy-acids which accelerate the corrosion of metallic parts When these oils are used, while also causing tendering of fibers to which such oils are applied. The formation of oxy-fats also has the drawback of accelerating oxidation of the oil. All these disadvantages are eliminated by the use of my sulphonated materials.

The carrying capacity of my materials for other non-sulphonated oils is also greatly improved. For example, in the preparation of cutting oils with ordinary sulphonated sperm oil, only 4 parts of paraffin oil can be added to 1 part of sulphonated sperm oil. With my anhydrous and of methyl ethyl ketone. The inorganic salt which salt-free sulphonated sperm oil, however, 6 to 8 parts of paraffln oil can be added without afiecting the stability and emulsiflability of the finished product. The resulting cutting oil is also greatly improved by reason of the fact that it does not have the corrosive action incident to the presence of large amounts ,of salts, which also catalyzes hydrolytic changes and which thus further favor the production of materials leading to such corrosive action of the oil.

The low water and salt content also makes it possible to prepare oils containing less titratable alkali representing soap, since our oils do not hydrolyze to the point where ordinary sulphonated oils become acid and therefore need more alkali to counteract the afiects of this hydrolysis.

The sulphonated materials obtained in the above examples are particularly suited to finishing treatments of textiles, leather,- paper, etc. Being substantially anhydrous and salt-free, they blend more efficiently with non-sulphonated fatty or mineral oils often used in such treatments, and give mixtures of greatly improved permanence and stability. Their emulsifying properties are also greatly enhanced because of the absence of the salts, condensation and polymerization products which inhibit part of the emulsifying power of sulphonated oils produced by the usual methods.

The sulphonating reagents and catalysts employed are immaterial since my process is directed to the treatment of the mass after it has been subjected to sulphonation and since my process can be used for sulphonated fatty oils, fatty acids or fatty derivatives produced with any of the sulphonating reagents employed for the manufacture of these oils.

The expression hydrolytic by-products is employed in the present specification and claims to connote the products formed by hydrolysis of the various constituent in sulphonated animal, vegetable and marine oils, fats and their respective fatty acids and fatty esters, said products specifically including, among others, fatty acids, oxy-fatty acids, glycerol, and sulphuric acid. The expression condensation and polymerization products is used herein to denote those products which are formed by condensation and polymerization reactions which occur during the step which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting ense.

It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described and all statements of the scope of the invention, which as a matter of language might be said to fall therebetween, and that they are intended to be inclusive in scope and not exclusive in that if desired other materials may be added to my novel composition of matter herein claimed without departing from the spirit of the invention. Particularly it is to be understood that in said claims, ingredients or components recited in the singular are intended to include compatible mixtures of said ingredients wherever the sense permits.

This application is a continuation-in-part of my co-pending applications, Serial Nos. 77,761 and 160,270, filed May 4, 1936, and August 21, 1937, respectively.

Having described my invention, what I claim as new and desire to secure by Letter Patent, is:

1. In a process of producing a substantially anhydrous and salt-free sulphonated material selected from the group consisting of animal, vegetable and marine oils, fats and their respective fatty acids and fatty esters, the steps which comprise dispersing the crude sulphonation mass in at least an equal volume of a substantially anhydrous organic solvent, neutralizing the sulphonated material, separating the insoluble products of neutralization and removing the solvent and water simultaneously by distillation.

2. In a process of producing a substantially anhydrous and salt-free sulphonated material selected from the group consisting of animal, vegetable and marine oils, fats and their respective fatty acids and fatty esters, the steps which comprise dispersing the crude ulphonation mass in at least an equal volume 01' a substantially anhydrous alcohol, neutralizing the sulphonated material, separating the insoluble products of-neutralization and removing the alcohol and water simultaneously by distillation.

3. In a process of producing a substantially anhydrous and salt-free sulphonated material selected from the group consisting of animal, vegetable and marine oils, fats and their respective fatty acids and i'atty esters, the steps which comprise dispersing the crude sulphonation mass in at least an equal volume of a substantially anhydrous chlorinated hydrocarbon solvent, neutralizing the sulphonated material, separating the insoluble products of neutralization and removing the solvent and water simultaneously by distillation.

4. In a process of producing a substantially anhydrous and salt-free sulphonated material selected from the group consisting of animal,

vegetable and marine oils, fats and their respective fatty acids and fatty esters, the steps which comprise dispersing the crude sulphonation mass in at least an equal volume of a substantially anhydrous ketone, neutralizing the sulphonated material, separating the insoluble products of neutralization and removing the solvent and water simultaneously by distillation. I

5. In a process of producing a substantially anhydrous and salt-free sulphonated material selected from the group consisting of animal, vegetable and marine oils, fats and their respective fatty acids and fatty esters, the steps which comprise dispersing the crude sulphonation mass in at least an equal volume of a substantially anhydrous isopropyl alcohol, neutralizing the sulphonated material, separating the insoluble products of neutralization and removing the alcohol and water simultaneously by distillation.

6. In a process of producing a substantially anhydrous and salt-free sulphonated material selected from the group consisting of animal, vegetable and marine oils, fats and their respective fatty acids and fatty esters, the steps which comprise dispersing the crude sulphonation mass in at least an equal volume of a substantially anhydrous ethylene dichloride, neutralizing the sulphonated material, separatingthe insoluble products of neutralization and removing the ethylene dichloride and water simultaneously by distillation.

7. In a process of producing a substantially anhydrous and salt-free sulphonated material selected from the group consisting of animal, vegetable and marine oils, fats and their respective fatty acid and fatty esters, the steps which comprise dispersing the crude sulphonation mass in at least an equal volume of a substantially anhydrous methyl ethyl ketone, neutralizing the sulphonated material, separating the insoluble products 0:! neutralization and removing the methyl ethyl ketone and water simultaneously by distillation.

8. In the process of producing a substantially anhydrous salt-free sulphonated vegetable oil, the steps which comprise dispersing a crude sulphonated vegetable oil in at least an equal volume of a substantially anhydrous organic solvent, neutralizing the sulphonated oil, separating the insoluble products of neutralization and removing the solvent and water simultaneously by distillation.

KARL T. STEIKr