US2861063A - Odor stabilization of sulfur-containing organic materials - Google Patents

Description

ODOR STABILIZATION OF SULFUR-CONTAINING ORGANIC MATERIALS United States PatentfO Fredrick L. Jonach, Kew Gardens, N. Y., assignor to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Application September 22, 1955 Serial No. 536,013

5 Claims. (Cl. 260-139) This invention relates to the odor stabilization of sulfur-containing organic materials which normally evolve hydrogen sulfide and more particularly relates to a method for stabilizing such materials by treating them with lead peroxide (PbO t0 the resultant stabilized products ing'eve'n small amounts of unstable sulfur-containing compounds will evolve hydrogen sulfide. Users of such compositions object to these odors and consequently the saleability of the product is impaired. Many organic compounds that have been sulfurized. or phosphosulfurized by treatment with sulfur, sulfides of phosphorus and the like show this characteristic instability with respect to hydrogen sulfide evolution. 7

Numerous attempts have been made in the prior art to stabilize such sulfur-containing compounds or compositions including these compounds. None of these prior art methods have been entirely effective and they have been especially ineffective with pho-sphosulfurized hydrocarbons which in general are extremely potent H 8 evolvers. It is unfortunate that heretofore it has not been possible to effectively stabilize these phosphosulfurized hydrocarbons since not only are they inexpensive but they are also among the most potent detergent and oxidation inhibitor additives known for lubricating oil compositions.

It has now been found that the evolution of hydrogen sulfide from unstable sulfur-containing organic materials may be effectively eliminated or at least partially reduced by treating these materials with lead peroxide (PbO The lead peroxide treatment also reduces the corrosivity of the sulfur-containing organic materials.

THE SULFUR-CONTAINING ORGANIC MATERIALS the sulfurized and/or phosphosulfurized hydrocarbons. These hydrocarbon materials maybe parafiins, such as bright stock residuums, lubricating oil distillates, petrola- 'tums, paraflin waxes, etc.; olefins, such as isobutylene,

P 3 P 8 P 8 or other phosphorus sulfide and is pref- 2,861,063 Patented Nov. 18, 1958 acrolein, decene, dodecene, cetene, octadecene,'etc.; olefin polymers having molecular weight ranges from about to 50,000, particularly from about 500 to l0,000, such as those of ethylene, propylene, butylene, isobut'ylene. amylenes, etc.; diolefins, such as butadiene, isoprene, chloroprene, cyclopentadiene, terpenes', etc.; acetylenes; copolymers of low molecular weight monoolefins and diolefins having molecular weight ranges of about 1,000 to 30,000; aromatics, such as-benzene, naphthalene,

'anthracene, toluene, xylene, diphenyl, etc.; alkyl aromatics; cyclic aliphatics; petroleum fractions; condensation products of halogenated aliphatic hydrocarbons with an aromatic compound and'the like.

Another class of sulfur-containing organic compounds which are useful as lubricating oil additives are sulfurized and/or 'phosphosulfurized oxygen-containing organic compounds. Included in this group are sulfurized and/ or phosphosulfurized animal and vegetable .oils, fats, rosins, resin and the acid ester hydrogenated and lower alkyl derivatures thereof. Included in this class are products such as sulfurized sperm oil, phosphorus sulfide treated ,rosin, rosin derivatives suchas methyl abietate and the like, for example, the products sold under the trade name Abalyn, Hercolyn and the like, as well as various sulfur and/or phosphorus sulfide treated organic acids,

methyl esters, etc., derived from these products and from lanolirndegras, tall oil, and the like. Such materials as have been described above are well known to those skilled in the art.

The su'lfurization and/or phosphosulfnrization of hydrocarbons, oxygen-containing organic compounds and thelike are also well known in'the art. Sulfurization is generally accomplished by reacting the organic compound withelemental sulfur. The sulfides of phosphorus which can be employed for phosphosulfnrization include P 8 erably phosphorus pentasulfide (P 5 Mixtures of two or more phosphorus sulfides may alsobe. employed as well as-mixtures of elemental phosphorus sulfur.

. The sulfurization and/ or phosphosulfurization reaction -is conveniently carriedout at an elevated temperature of about'200 to 600 F., preferably about 300 to about 550 F., using in general about 2 to about 5 molecular proportions of the organic compound to '1 molecular proportion of sulfur or phosphorus sulfide in the reaction. The-reaction will generally be carried out until the maximum amount of sulfur or phosphorus sulfide has been added to the organic compound although this is not essential. The reaction time is not'critical and the time required to cause the maximum amount of sulfur or phosphorus sulfide to react will vary with the temperature. A reaction time of 2 to 10 hours is frequently necessary and, if desired, the reaction product may be further treated by blowing with steam, alcohol, ammonia, or an amine at an elevated temperature of about 200 F. to improve the odor thereofvto a certain extent. The sulfur-containing organicmaterials ofthis invention will generally contain at least 1.0% and usually at least 2.0% by weight of chemically combine-d sulfur. P 8 treated polyi'sobutylenes having molecular weights in the range of about 500 to 25,000, particularly about 500 to 2,000, are especially stabilized effectively in accordance 'with this invenmaterials in accordance with this invention is accomplished by treating these materials with lead peroxide -(PbO In general, the'unstable sulfur-containing organic materials will be treated with a small amountof Pb0 at an elevated temperature for an extended per od of time. In the stabilization reaction, the reaction variables, namely, temperature, time and proportion of PbO are interchangeable to a certain extent. Generally more effective stabilization .will be'obtained when using higher temperatures, longer reaction times and greater proportions of P130:-

Elevated temperatures in the range of about 80 to 400 F. are generally efiective in the stabilization reaction carried out in accordance with the present inventon. Temperatures in the range of about 150 to 350 F. are ureferred and a temperature of about 300 F. has been shown to be exceedingly effective. As to the reaction time, generally a period of at least about one hour is required. Effective stabilization is obtained when utilizing reaction times of about 8 to 24 hours, preferably about 12 to 16 hours. In general, about 0.5 to 50% by weight of PbOg will be employed, based on the sulfurcontaining organic material to be stabilized. Proportions of PhD, in the range of about 5% to 30% by weight, based on the sulfur-containing organic material, are preferred and exceedingly effective results are obtained when utilizing about 10 to 25% by weight of PbO If the sulfur-containing organic material is liquid under the treating conditions, the treating reaction may be carried out without a solvent. However, in general, it is preferred to carry out the stabilization reaction of the present invention in the presence of a solvent for the sulfur-containing organic material. Hydrocarbon solvents are preferred, with a mineral lubricating oil being the preferred solvent since normally the sulfur-containing organic materials useful as lubricating oil additives are marketed as additive concentrates consisting of the additive in a diluent mineral oil. The stabilization reaction is preferably carried out with intimate mixing of the reactants, such as by stirring the reaction mixture. It is preferred to utilize PbO in a finely divided form (such as a powder) to provide ready contact between it and the sulfur-containing organic materials. After the stabilization reaction, any unreacted PbO may be filtered from the reaction mixture. The stabilized reaction products of this invention will in general contain in the range of about 0.1 to 10 wt. of lead as a result of the stabilization reaction.

The invention will be more fully understood by reference to the following examples. It is pointed out, however, that the examples are given for the purpose of illustration only and are not to be construed as limiting the scope of the present invention in any way.

Example I The sulfur-containing organic material to be stabilized in accordance with the present inventin.--A polyisobutylene of about 1100 Staudinger molecular weight was reacted with about 10% by weight of P 8 (based on the polyisobutylene) at a temperature of about 425 F. for about 8 hours. The phosphosulfurized polyisobutylene was diluted with a mineral lubricating oil to form two additive concentrates, product A containing about 40% and product A containing about 50% by weight of the phosphosulfurized polyisobutylene.

Treatment of Product A with PbO .--l00 grams of product A were then stirred with 10 grams of powdered PbO at a temperature of about 190 F. for about 30 hours. The resultant stabilized reaction product, hereinafter referred to as product B, was blended with a solvent refined mineral lubricating oil (having an S. U. S. viscosity at 210 F. of about 45 seconds and hereinafter referred to as the base stock) to form a lubricating oil composition containing about 10 vol. percent of product B. This composition was diluted with normal heptane and filtered through Celite filter aid. The heptane was removed, giving a light-colored lubricating oil composition of excellent odor characteristics. a

A second lubricating oil composition was prepared 4 using product A. This second composition consisted of about 10 vol. percent of product A in the base stock. These two compositions had the following properties:

1 The lead acetate test is an effective test for determining the stability as to 1123 evolution of compositions containing sulfur-containing organic materials. This test is carried out as follows: 800 cc. of the oil composltion are placed in a l-quart bottle and heated at 120F. for one hour. Then a piece of paper moistened with saturated lead acetate solution is exposed to the blend for a period of 5 minutes. The resultant lead sultide stain is rated for its intensity, a rating of 10 being a dark stain with a trace of silvery overlay, a rating oi 0 being no stain, and a rating of 10+ being a stain with considerable silvery overlay.

It will be noted that the method of the present invention is exceedingly effective in stabilizing a sulfur-containing organic material such as phosphosulfurized polyisobutylene. More specifically, it will be noted that the oil composition containing product B of the present invention had a 0 rating in the lead acetate test whereas the oil composition containing product A had a rating of 10+ in the lead acetate test.

Example 11 Product A was stabilized, in accordance with the prescut invention, utilizing varying proportions of powdered PbO and varying reaction times to produce stabilized additives as shown below.

1 The lead acetate test was carried out in this example in the following manner: The treated product was blended with the base oil to term a composition of 10 weight percent of the treated product and 90 weight percent of the base oil. The resultant composition was then rated for E28 evolution as described in Example I.

It will be noted that the evolution of hydrogen sulfide from product A was reduced by treating it with PbO, in accordance with the present invention. When reaction times of 12 hours or greater were employed, there was no detectable evolution of H 8 from the treated product in the lead acetate test.

Example III In this example, product A was blended with the base stock to prepare compositions containing about 10 wt. percent of product A in the base stock. Portions of this composition were treated with powdered PhD, at several different reaction temperatures to prepare stabilized compositions as shown below.

TABLE up k 1 Stabilization reaction carried out with a blend of weight percent of product A in the base stock.

2 The lead acetate test in this example was carried out as described in Example I.

It will be noted that the evolution of H 8 from the compositions containing product A was substantially reduced by treating the compositions with PhD, in accordance with the present invention.

When the stabilized products, particularly the stabilized phosphosulfurized hydrocarbons, of the present invention are employed in lubricating oils, they are generally added in proportions of about 0.1 to about 10.0% and preferably about 1.0 to about 6.0%, based on the total composition. The proportions giving the best results will vary somewhat according to the nature of the additive and the specific purpose which the lubricant is to serve in a given case. For commercial purposes, it is convenient to prepare concentrated oil solutions in which the amount of the stabilized additive in the composition ranges from to 75% by weight, and to transport and store them in such form. In preparing a lubricating oil composition for use as a crankcase lubricant, the additive concentrate is merely blended with the base oil in the required amount.

The products of the present invention may be employed not only in ordinary hydrocarbon lubricating oils but also in the heavy duty type of lubricating oils which have been compounded with such detergent type additives as metal soaps, metal petroleum sulfonates, metal phenates, metal alcoholates, metal alkyl phenol sulfides, metal organo phosphates, phosphites, thiophosphates, and thiophosphites, metal xanthates and thioxanthates, metal thiocarbamates, and the like. Other types of additives, such as phenols and phenol sulfides, may also be present.

The lubricating oil base stock used in the compositions of this invention may be straight mineral lubricating oils or distillates derived from parafiinic, naphthenic, asphaltic or mixed base crudes, or, if desired, various blended oils may be employed as well as residuals, particularly those from which asphaltic constituents have been carefully removed. The oils may be refined by conventional methods using acid, alkali and/or clay or other agents such as aluminum chloride, or they may be extracted oils produced by solvent extraction with solvents such as phenol,

sulfur dioxide, etc. Hydrogenated oils or white oils may be employed as well as synthetic oils prepared, for example, by the polymerization of olefins or by the reaction of oxides of carbon with hydrogen or by the hydrogenation of coal or its products. In certain instances cracking coal tar fractions and coal tar or shale oil distillates may also be used.

Synthetic lubricating oils having a viscosity of at least S. S. U. at 100 F. may also be used, such as esters of monobasic acids (e. g. the ester of C Oxo alcohol with C Oxo acid; the ester of C Oxo alcohol with octanoic acid, etc.), esters of dibasic acids (e. g. di-Z-ethyl hexyl sebacate, di-nonyl adipate, etc.), esters of glycols (e. g. C Oxo acid diester of tetraethylene glycol, etc.), complex esters (e. g. the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of Z-ethyl-hexanoic acid; the com- -plex ester formed by reacting one mole of tetraethylene glycol with two moles of sebacic acid and two moles of 2- ethyl hexanol; the complex ester formed by reacting together one mole of azelaic acid, one mole of tetraethylene glycol, one mode of C Oxo alcohol, and one mole of C Oxo acid), esters of phosphoric acid (e. g. the ester formed by contacting three moles of the mono methyl ether of ethylene glycol with one mole of phosphorus oxychloride, etc.), halocarbon oils (e. g. the polymer of chlorotrifluoroethylene containing twelve recurring units of chlorotriflu-oroethylene), alkyl silicates (e. g. methyl polysiloxanes, ethyl polysiloxanes, methyl-phenyl polysiloxanes, ethylphenyl polysiloxanes, etc.), sulfite esters e. g. ester formed by reacting one mole of sulfur oxychloride with two moles of the methyl ether or ethylene glycol, etc.), carbonates (e. g. the carbonate formed by reacting C Oxo alcohol with ethyl carbonate to form a half ester and reacting this half ester with tetraethylene glycol), mercaptals (e. g. the mercaptal formed by reacting 2- ethyl hexyl mercaptan with formaldehyde), formals (e. g. the formal formed by reacting C Oxo alcohol with formaldehyde), polyglycol type synthetic oils (e. g. the compound formed by condensing butyl alcohol with fourteen units of propylene oxide, etc.), or mixtures of any of the above in any proportions. Also, mixtures of these synthetic oils and mineral oils in any proportions may be employed. Also, for special applications, animal, vegetable or fish oils or their hydrogenated or voltolized products may be employed in admixture with the synthetic and/or mineral oils.

For the best results the base stock chosen should normally be an oil which with the new additive present gives the optimum performance in the service contemplated. However, since one advantage of the additives is that their use also makes feasible the employment of less satisfactory mineral oils, no strict rule can be laid down for the choice of the base stock. The additives are normally suificiently soluble in the base stock, but in some cases auxiliary solvent agents may be used. The lubricating oils will usually range from about 40 to 150 seconds (Saybolt) viscosity at 210 F. The viscosity index may range from 0 to or even higher.

Other agents than those which have been mentioned may be present in the oil composition, such as dyes, pour point depressants, heat thickened fatty oils, sulfurized fatty oils, sludge dispersers, antioxidants, thickeners, viscosity index improvers, oiliness agents, resins, rubber, olefin polymers, and the like. Assisting agents which are particularly desirable as plasticizers and defoamers are the higher alcohols having preferably 8 to 20 carbon atoms, e. g. cctyl alcohol, lauryl alcohol, stearyl alcohol, and the like.

In addition to being employed in lubricants, the additives of the present invention may also be used in other mineral oil products such as motor fuels, hydraulic fluids, torque converter fluids, cutting oils, flushing oils, turbine oils, transformer oils, industrial oils, process oils, and the like, and generally as useful additives in oleaginous products. They may also be used in gear lubricants, greases and other products containing lubricating oils as ingredients.

What is claimed is: I

1. An odor stabilized organic product obtained by treating a phosphorus sulfide treated olefin polymer with Pb0 at an elevated temperature in the range of 80 to 400 F. for a time in the range of 8 to 24 hours.

2. A stabilized organic product obtained by treating a phosphorus sulfide treated olefin polymer with about 5 to 30% by weight of PbO at a temperature of about to 350 F. for about 8 to 24 hours.

3. A stabilized organic product obtained by treating a P 5 treated polyisobutylene having a molecular Weight of about 500 to 2,000 with about 10 to 20% by weight of PbO at about 300 F. for about 12 to 16 hours.

4. A method for reducing the evolution of hydrogen sulfide from a phosphorus sulfide treated olefin polymer which comprises treating said phosphorus sulfide treated polymer with about 5 to 30% by weight of finely divided PbO at a temperature of about 150 to 350 F. for about 8 to 24 hours.

5. A method for reducing the evolution of hydrogen sulfide from 21 P 8 treated polyisobutylene having a molecular weight of about 500 to 2,000 which comprises treating said P 8 treated polyisobutylene with about 10 to 20% by weight of finely divided PbO at about 300 F. for about 12 to 16 hours, and removing unreacted PhD; from the resultant reaction mixture.

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References Cited in the file of this patent UNITED STATES PATENTS Musselman Dec. 11,

Claims (2)

1. AN ODOR STABILIZED ORGANIC PRODUCT OBTAINED BY TREATING A PHOSPHORUS SULFIDE TREATED OLEFIN POLYMER WITH PBO2 AT AN ELEVATED TEMPERATURE IN THE RANGE OF 80* TO 400*F. FOR A TIME IN THE RANGE OF 8 TO 24 HOURS.

4. A METHOD FOR REDUCING THE EVOLUTION OF HYDROGEN SULFIDE FROM A PHOSPHORUS SULFIDE TREATED OLEFIN POLYMER WHICH COMPRISES TREATING SAID PHOSPHORUS SULFIDE TREATED POLYMER WITH ABOUT 5 TO 30% BY WEIGHT OF FINELY DIVIDED PBO2 AT A TEMPERATURE OF ABOUT 150* TO 350*F. FOR ABOUT 8 TO 24 HOURS.