US2374682A - Oil-phosphatide composition - Google Patents

Description

Patented May 1, 1945 OIL-PHOSPHATIDE COMPOSITION Percy L. Julian, Maywood, and Edwin W. Meyer, Evanston, Ill., assignors, by mesne assignments, to American Lecithin Company NoiDrawing. Application July 25, 1941,

' Serial No. 403,994

1 Claims. (01. 252-51) The present invention relates to oil-phosphatide compositions and especially to lubricating oils having reduced varnish forming properties and/or reduced emulsifying properties.

Lubricating oils used in present day automobiles and other high compression engines and the like are subject to varnish formation caused by the high temperatures and pressure to which the lubricating oil is subjected during use.. Numerous treatments have been proposed to overcome this varnish formation. Phosphatides, such as maybe obtained from soybeans or other sources, are usefulior this purpose. Phosphatides generally available commercially are emulsifying agents; Since in normal'use the lubricating agents come into contact with water the presence of these phosphatides results in stable emulsions which are undesirable.

It is accordingly an object of the invention to provide an oil-phosphatide mixture of reduced emulsifying properties.

Another object is to provide a lubricating composition of reduced or retarded emulsifying properties. v

Another object is to provide a lubricating oil composition containing phosphatides which will have reduced or limited emulsifying properties.

A further object is to provide a method for decreasing varnish formation and to prevent emulsiflcation of lubricating oils.

An additional object is to provide a method for decreasing or retarding emulsiflcation of lubricating oils.

Further objects will appear from the descrip-' tion whichiollows.

It has been found that the desired objects of the present invention may be obtained by treating the phosphatide with an acid substance capable of reducing the pH value of the phosphatide and incorporating the thus treated phosphatide into the lubricating oil.

/ This method of incorporating the acid substances i is described in our copending application Se- Compounds like phosphatides of the lecithin variety are zwitter ions and have long been recognized as good emulsifying agents since they contain a large oil soluble residue in the molecule as well as water soluble groupings. Thus the amino groups and the phosphoric acid groups have a tendency to be attracted to water, while the fatty acid portions would tend to be at tracted to the oil. By treating the phosphatide with acid substances the charges upon the "zwitcreased. Slnce'the charges which tend to cause' water solubility are neutralized the phosphatide has its minimum solubility in water and consequently is at or near the iso-electric point.

It is important, however, that the acid substance be uniformly distributed throughout the mass. In the case ofwater soluble acids these may be incorporated into aqueous emulsions of the 'phosphatide and the emulsions then dried.

rial No. 403,990, filed July 25, 1941.

Where oil soluble acids are used they are generally incorporated into a dry phosphatide-glyceride oil mixture, preferably in the molten or fluid condition.

In our copending application Serial No. 403,991, filed July 25, 1941, is described the method of incorporating oil soluble acid liberating substances such as acyl halides, 'sulfonyl halides, acyl pyridinium and substituted pyridinium halides. In our'copending application Serial No. 403,992, filed July 25, 1941, is described the incorporation of concentrated phosphoric acid and glycerol phosphoric acid into dry phosphatide glycerol mixtures. In our copending application Serial No. 403,993, fl1ed July 25, 1941, is described the incorporation-of oil soluble sulfonic acids into phosphatide mixtures. Coacervates of phosphatides with proteins, amino acids, and similar amino compounds may also be employed. In the case of these coacervates it is believed that the charges on the phosphatide molecule are neutralized by coacervation although applicants do not wish to be bound by this theory. Weisehahn Patent No. 2,198,842, dated March 26, 1940, de-

scribes the incorporation of fatty acids into the phosphatide' mixture.

It has been found that when phosphatides treated according to any ofthe above mentioned procedures are added to lubricating oil the emulsifying tendency is reduced or substantially eliminated and at the same time the varnish inhibiting action of the phosphatide is retamed.

As mentioned in the above identified applications, the addition of smaller amounts of acid or acid-liberating substances does not bring about a substantial reduction in the emulsifying properties. However, upon the addition of further amounts a sharp break in the emulsifying properties occurs, further addition beyond this point having only a slight effect upon the emulsifying property.

It is important, however, that the acid material be uniformly distributed throughout, the phosphatide mass, The amount of acid material added will depend somewhat upon the particular composition of-the phosphatide-oil mix tures and upon the "particular acid used. The change in emulsifying properties appears to be dependent upon the nature of the charge or charges upon the phosphatide-molecule. Thus a substantial reduction in emulsifying power does to produce the proper reduction ofthe pH value not occur the addition of the smaller quantities of acid material but appears .to take place only upon the addition of a suiilcient amount of acid of the mixture. pH values determined on the water layer formed by emulsifying lubricating oil ever; do notwish to be understood as meaning that the pH? value of the water layer is neces-' sarily or always a true indication of the pH value of the dry mixture itself or of the true condition -of the charges upon the phosphatide molecule.

The pH value obtained in the water layer may depend to some extent upon the amount of the particular acid dissolved in the water. However,

the dry phosphatide-oil mixture is of a lipophilic nature and consequently the pH of an aqueous solution of an acid may not necessarily represent the true condition of the charges uponthe phosphatide molecule. The decrease in theeinulsifying properties, however, does occur rather sharply and may be readily determined. While the emulsifying properties do not substantially decrease until this critical point is reached more acid may be added if desired and still produc the decreased emulsifying properties. v

Among the acid substances which may be used may bementioned mineral acids such as hydrochloric, sulfuric, and phosphoric; glycerol phos phoric; sulfonic acids such as benzene sulfonic acid; fatty acids such as stearic, soybeanoil fatty acids, lauric, etc. acid liberating substances such I as acyl halides including stearoyl chloride and soybean oil acid chlorides, benzoyl chloride; sulfonyl halides such as toluene sulfonyl chloride:

acyl pyridinium halides such as benzoyl pyridinium chlorides; and substituted pyridinium halides such as stearoyl quinolinium and stearoyl acridinium chloride.

The amount of acid or. acid liberating substances used will vary somewhat depending upon the particular acid substance used but since the break in emulsifying properties is sharp the amount necessary may be readily determined.

The coacervates also show inhibited emulsifying properties. EXAMPLE I Hydrochloric. acid was ,added in varying amounts to aliquot parts of a soybean oil-phosphatide emulsioncontaining about 50% water,

about 32.5% phosphatides and about 17.5% 011..

' The pH values of the acidified emulsions-were obtained and the emulsions dried. The emulsifying properties. of the mixtures of phosphatide mersed in a heating liquid anda temperature of 180 F. was maintained during the tests. Themixtures were agitated forminutes. and allowed to stand at the test temperature for specified lubricating oil times. The mixtures separated into three layers, an oil layer, a water layer and an emulsion layer. The number of ml. in the emulsion layers were observed. Similar experiments were run using ammonium hydroxide to increase the pH value. The results are shown in Table I.

TABLE I M]. of emulsion pH values min. '30 min. 45 min. 60 min.

EXAMPLEII TABLE II 0.1% 0] phosphatidegluceride oil-acid min: used in emulsification tests Amoumaoid MLofemulsion' pH of Acid material ag water .1? mix 15 30 layer 4 min. min. min. min.

. Percent .Untreated phosphatide 40.0 4410 45.0 44.0 5.0

Stesrol 1 41.5 440 42.0 40.5 4.58 Pgridziium 2.5 43.5 40.0 30.5 3&0 4.10 50 c lei-me 5.0 3.0 2.0 1.5 1.5 3.15

Do 10. 0 3. 0 3. 0 3. 0 a. 0 3. 5o

2 -4s.5 45.5 42.0 42.0 5.8 Y I a sac 20.5 1&0 13.0 5.72 4 4.0 25 2.0 2.0 510 5 2.5 2.0 1.5 1.0 an

- Toluene 4 0.6 0.0 0.0 0.0 4.10 Bulfonyl chloride. 5 2.0 1.0 1.0 0.5 4.05

B e a0 1.0 1.0 1.0 1.0 4.71 -Sulionic 3.5 1.5 1.0 1.0 1.0 4.31 Acid 5.0 2.5 2.0 2.0 20 4.0a 7.0 3.0 2.5 2.0 .20 3.00

00 Glycero 2.5 8.0 4.0 4.0 25 4.81 Phosphoric 5.0 2.5 2.5 2.0 2.0 431 Acid 20.0 8.5 5.0 4.0 8.5 3.0 I

' EXAMPLE III 06 To aliquot parts of a mixture of soybean phosphatide and soybean oil containing about parts of phosphatide and about 35 parts of soybean oil were incorporated 3% of soya oil fatty acid chlorides by mixing at about80? C. When 1 the dispersion was complete emulsiflcation. tests were then made asfin Example I by employing varying amounts of this .phosphatide-glyceride oil-acid chloride mixture. with the results shown I! inTablcIII. 7 a

lntreatcd pbosphatide In addition to gelatin, other proteins and aim Tests 111 3% o soya acid chlorides used with phosphatideoil mixtures Per cent oi hospbatideoil-acid c loride mixture used in emulsification test Ml. oi emulsion 15 min. 30 min. 46 min. 60 min.

Untreated phcsphatlde- EXAMPLEIV no acids such as egg albumin or glycine may-be employed.

We have given examples of the invention which have been'found to be useful but they are to be considered by way of illustration and not of limitation; One skilled in the art will obviously vary the amounts of proportion of the ingred-ients to get optimum results.

It is not to be understood from the foregoing description that a mixture of phosphatide and glyceride oil must inall cases be treated or that the composition used necessarily in all cases cohtains 'glyceride oil. Phosphatide alone may be treated and used, or the glyceride oil may be removed from a treated phosphatide-glyceride oil mixture in the same manner as described in Example I. Emulsification tests, as in Example I, were then made employing varying amounts of this phosphatide-glyceride-oil-phosphoric acid Tum: IV

5% 85% phosphoric acid in'phosphatide-oil mixture Per cent pbosphatido Ml'mamumon used 11 acid mixture pH of o in emulsiflcation water layer 45 min. 00 min.

To an emulsion of about 50% water, about 32.5% soybean phosphatides, and about 17.5% soybean oil was added a water solution containing of gelatin on the basis of the weight of phosphatides contained in the emulsion. After thorough agitation, a volume of hydrochloric acid solution suflicient to produce an acidity of about pH 2.0 was added. The curdy mixture was dried under vacuum in a steam-jacketed kettle equipped with a mechanical agitator. The temperature of drying was regulated at 70-80 C. The product when sufliciently dried is a fluid mass of high viscosity. To enhance the color, bleaching with benroyl peroxide and/or hydrogen peroxide may be resorted to. The emulsifying characteristics of lubricating oil treated with three separate preparations prepared in the tide has been sufliciently treated in the manner indicated. a

The invention is considered to reside broadlyposition suitable for lubricating high pressure such an amount of acid material that the charges upon the "zwitter" ions which tend to cause water solubility have been neutralized and the phosphatidic material is therefore at or near its isoelectrlc point.

manner indicated were then determined by the Navy test.

Tun: V

Emulsion tests-Gelatin coacervate Per cent M]. of emulsion addition to oil 16min. 30min. 45min.

sso-u-n-n acmenoon:

- 2. A composition comprising a major amount of mineral oil and a minor amount of a phoshatide which has been treated with sumcient acid material so that the charges upon the "switter ions which tend to cause water solubility have been neutralized and the phosphatide material is therefore at or near its iso-electric point.

3. The lubricating composition of claim 1 in which the phosphatide is soybean phosphatide.

4. A composition comprising a major amount of mineral oil and a minor amount of a glyceride oil containing phosphatide composition which has been treated with such an amount-of acid material that the charges upon the phosphatide zwitter ions which tend to cause water solubility have been neutralized and the phosphatide is therefore at'or near'its iso-ele'ct'ric point.

5. The composition of claim 2 in which the acid material is oil dispersible.

'6. The composition of claim 2 in which the acid material is oil dispersible' and thc'phos'phatidc is soybean phosphatide.

"I. The composition .of .claim in which the phosphatide is soybean phosphatide.

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