US2586690A - Pour depressants - Google Patents

Description

Patented Feb. 19, 1952 POUR DEPRESSANTS .Louis A. Mikeska, Westfield, N. J., assignor to 'Stan'dardOil Development Company, a corporationof'Delawal-e .No Drawing. Application May 29, 1948, Serial No. 30,180

4 Claims. (01. 260-609) This invention relates to novel lubricating compositions and to the preparation thereof. More particularly, itrelates to the preparation of certain novel products for the purpose, adding such products to lubricating oil compositions to improve their properties. The invention further relates to a new methodoflowering or depressing the pourpoint of waxy mineral lubricating oil.

Many difierent problems are involved in the production of waxy mineral lube oils which will pour or flow readilyat low temperatures such as those encountered in cold climates or even in winter time in warmer climate. One way of partially solving this problem is to dewax the oil, but this is expensive and in certain respects reduces the quality of the oil. Another method which may either be used alone'or in conjunction with a light dewaxing is to add to the waxy lubricant a small amount of a substance called a'pour depressor which modifies the properties of the wax during crystallization and prevents the growth of the long needle-like crystals, the interlocking of which is primarily responsible for the apparent solidification of the oil. In the use of such pour depressors, it is known that sometimes a pour depressor will have relatively good potency in some waxy lubricating oil base stockandrelatively poor potency in other waxy lubricating oil base stock. It .is also known that two or more different pour depressors having'relatively the same pour depressor potency as tested by'th'e standard A. S. T. M. pour point test may be quite different in regard to their pour stability as measured by the procedure described in Oil and Gas Journal, June 24, 1943, page 43, using the apparatus labeled Fig. V, or by other tests.

The present invention was based upon the discovery that the potency of pour-dep'ressorscan be markedly improved by incorporating into the pour depressor itself prior to the-addition to .the waxy mineral lubricating oil axsubstanfee which in itself is not an ie'irective p'ou'r depressor but which acts-to enhance the potency o f-agiven pour -depressor with noloss-of stability.

It is known-that wax modifyingagentsmay be prepared by condensation ofrela-tivelylon'g chain paraffi'nic material such as chlorinated parafiin wax or olefins corresponding thereto with aromatic hydrocarbons such as phenol. The condensation .of such materials has generally been carried out in the presence of a Friedel-Cra'fts catalyst such as aluminum chloride, boron fluoride, etc preferably .in the presenceof .an inert solvent. This .product is oil soluble and has an average molecular weight above "1000 preferably "from I500 to "5000and.generally has very 2 good pour "depressing properties as determined by standard A. S. T. M. pour point tests.

However, under field conditions of winter storage, the oil blends are subjected to frequent fluctuationsof high and low temperatures. These blends have sometimes been found to be solidat temperatures substantially above the A. S. T. M. pour point. It is a primary object of the present invention to modify those Friedel-Crafts condensation products in such a way as to either improve their potency, or their pour stability, or both.

Broadly the present invention comprises modifying such wax modifiers and pour depressors which may be referred to as high molecular weight Friedel-Crafts condensation products by directly condensing them further with alpha or beta chloro ethers having an ether linkage which may be represented by the general formula R-XRHal where R and R represent aliphaticradicals, at least one of which contains from 8 to 18 carbon atoms, Hal represents a halogen and X represents a radical selected from the class consisting of O-, S and O-CS-'S-. Linkages having oxygen or sulfur as the bridging element have similar characte'ristic's. The xanthate type ether linkage has the characteristics of both: that is to say it may be considered as an oxygen linkage or a sulfur linkage or as a combined linkage involving both oxygen and sulfur as bridging elements.

The invention may be modified byfirst condensing the initial aromatic aliphatic condensation product with formaldehyde in the presence of hydrogen chloride to obtain a halo-methyb.

phenol and then condensing further with an alkali metal mercaptan. One or more groups having the general formula may be introduced into the aromatic nucleus. lows:

Wax phenols can be condensed with a-ChlOl'O- ethers by merely heating amixture of the two ingredients. When p-chloroalkyl ethers are used as the modifying agents, Friedel-Crafts type catalysts must be used; Two reactions may be carried out at temperatures ranging from 10 C. to C.

Complex thioethers and .polyethers and xanthates such as the following may be used for the purpose of this reaction:

The basic conditions are as folatsaeoo Phenol or alkylated phenol when condensed with three or more molecules of chloroalkyl ethers, thioethers, or xanthates yields an effective pour depressant. This condensation generally follows the pattern of the following equation:

If desired the preparation of the stabilized pour depressant may be carried out in the presence of chloroethers or chlorothioethers, thus saving an extra step in its manufacture generally the direct condensation product of ethers or thioethers with wax phenol gives a product having greater pour stability and is to be preferred.

The invention will be better understood from a consideration of the following experimental data:

Example 1 93 gms. of wax phenol (0.15 mol based on the hydroxyl group), 39.? gms. (=0.15 mol of B- chloroethyl lorol sulfide (C1CH2CH2SC12H25), and 150 cc. of Varsol were placed into a 3-way flask equipped with a stirrer and a return condenser. The lorol radical is obtained from hydrogenated coconut oils and comprises principally the C12 or lauryl radical. An alcohol containing principally lauryl alcohol obtained in this manner is available commercially as Lorol. 10 gms. of aluminum chloride was then added, little by little, over a period of 20 min. The temperature of the reaction mixture was then raised to, and maintained at, TO-75 C. for 2 hours, and then at 90-95" C. for 5 hours. The reaction mixture was rapidly stirred throughout the time.

On completion of the reaction the product was poured into a mixture of ice and hydrochloric acid, and was extracted with ether. The extract was washed free of hydrochloric acid and dried over sodium sulfate. The solvents and unchanged B-chloroethyl-lorol sulfide were removed by heating in a Claisen flask at 2 mm. and 300 C. bath temperature until no more product distilled. The residue consisted of 115.4 gms. of dark viscous oil which showed the following pour characteristics when blended with paraflin base oil.

4 Example 2.-LauryZthiomethyl-wamphenol Alkylthiomethyl-waxphenols may be prepared in either of two ways. In both cases the end products have the same general structure. One may simply condense waxphenol with chloro- -methylalkyl thioether by heating the two ingredients together. But in this case, some side reactions take place which result in considerable amount of polymerization or formation of high molecular weight products. Better results can be obtained if the following procedure is followed:

To accomplish the desired objective, the reaction is carried out in two steps. First, the wax phenol is condensed with formaldehyde in the presence of hydrogen chloride to yield chloromethyl phenol, which is in turn condensed with an alkali metal mercaptide.

Step Number 1-Chloromethyl-waxph enol.-A

3-way flask equipped with a stirrer, a return condenser and an inlet tube for hydrogen chloride,

was charged with 42 gms. (1.4 mol) of trioxymethylene, and 300 ml. benzene. Dry hydrogen chloride was then passed through the mixture at 25 C. with rapid stirring until saturated. Seventeen grams of hydrogen chloride were absorbed. To this was then added slowly (over a period of 20 min.) with stirring and cooling a solution consisting of 295.7 gms. of waxphenol and 300 ml. of benzol. When all the waxphenol had been added the temperature was raised to 45-50 C. and maintained at this point throughout the reaction time of 4 hours. A slow stream of hydrogen chloride was passed through the mixture continuously.

On completion of the reaction, the mixture was cooled, poured into ice water and extracted with ether. The ether extract was washed several times with ice water and was then dried over sodium sulfate. On removal of the solvent at C. under 2 mm. pressure, a viscous brown residue weighing 310 gms. was obtained. This product may be designated as Product A. It was found to contain.4.33% organic chlorine.

Step Number z.-'-Laurylthiomethyl-wa.rphenob-A 3-way flask equipped with a stirrer, a return condenser, a thermometer, and a dropping funnel was charged with 50.5 gms. of lauryl mercaptan and 400 ml. dioxane. To this was then added 23.5 gms. of sodium methylate. The dropping funnel was charged with gms. of chloromethyl waxphenol (Product A above) dissolved in 150 ml. dioxane. The latter was then added slowly to the reactor with rapid stirring.

The temperature rose spontaneously from 25 to 45 0. As the reaction progressed, the product in the flask became extremely viscous, hence a little toluene was added to reduce its viscosity. When all of the chloromethyl derivative had been added, the temperature was raised to residue which consisted of 1'76 gms. of dark brown viscous liquid, may be designated as Product B.

'A. S. T. M. pour point data on the product were obtained in the concentrations indicated,

" in an oil of SAE 10 grade consisting of a mixture of extracted Mid-Continent neutral and extracted Mid-Continent Bright Stock. This base assesseoil was also used in all the other examples described below.

In the S. 0. D. Pour Stabilit Test described on page 89, vol. 46, Oil and Gas Journal (1947), the 0.25% blend solidified at F. As the weight of the condensate is 17% greater than that of the original waxphenol, the former has decidedly higher A. S. T. M. potency than the latter. This product too, unlike the unmodified waxphenol, is active not only as a pour depressantbut also "as an anti-oxidant or an anti-corrodant.-

Example '3.-TertiaryoctyZthiomethyZ-wazphenol A highly effective product as a pour depressant and an anti-oxidant was also obtained on substitution of tertiary octyl mercaptan for the lauryl mercaptan in a modification of the reaction described in Example 2. In this case, the reaction was carried out in one step as follows:

A 3-way flask equipped with a stirrer, a return condenser and an inlet tube for hydrogen chloride, was charged with 108 gms. of waxphenol (0.2 mol) 42.3 gms. (0.3 mol) of tertiary octyl mercaptan and 9 gms. (0.3 mol) of trioxymethylene. Then, while stirring, hydrogen chloride gas was passed through the solution at room temperature. The temperature rose spontaneously to 50 C. It was maintained at this point for two hours, and the reaction was finally brought to completion by refluxing for 1 hOurS. Hydrogen chloride was passed through the solution throughout the time.

The mixture was cooled. poured into water, and then extracted with ether. The extract was washed and dried over sodium sulfate. On removal of the ether, the residue was topped at 150 C. bath temperature under 2 mm. pressure. The reaction product consisted of 122 gms. of dark brown viscous liquid. Its pour depressant. properties were determined in the same base' oil as was used in the previous examples, andthe tests were carried out in the concentrations indicated below:

In the s. o. D. Pour Stability test the 0.25% blend solidified at +15 F.

Eaiample 4.-LaurylxanthomethyZ-waxphenol Chloromethyl-waxphenol was prepared as desired in Step 1 of Example 2. The chlorinated product was found to contain 3.84% chlorine.

To prepare the .xanthomethyl derivative 1:. 3- way flask equipped withastirrenn return condenser, and a thermometer-was chargedwith 500 m1. of benzene, .135 (0.2 .mol) of the above described chloromethyl-waxphencil, and 10.8 gms. of sodium methylate. The mixture was stirred for awhile =atroom temperature whereupon 41.5.

gms. (0.146 .mol) sodium lauryl .xanthate was added. The mixture wasth-en refluxedro'r four hours withrapidstirring.

:On c001ing,xthe .mixture was poured into-water. acidified with a slight :excess 0f hydrochloricacid, and extracted with ether. The extract was washed with water and :finally drie'dover-sodium sulfate. .On removal .01 the solvent at C. and 2 mm. pressure a residue weighing 159 gms. and consisting of a dark brown oil was obtained. Its pour point characteristics were determined in the same oil and in the same way as was used in the previous examples.

TABLE V Percent 00110. A. S. T. M. Product of Additive Pour Point in Base Oil F.

Base Oil 0 +30 Condensate 0. 25 45 D0. 0. 50 35 Do 1.00 (-35 Original waxphenol 0. 25 20 Do 0. 50 --30 Do 1.00 (-35 In the S. O. D. Pour Stability test the 0.25% blend solidified at +15 F. Here again, as in the previous examples, though the weight of the modified material exceeded the weight of the starting product by 18%, the former proved to be decidedly more active than the latter.

The products obtained as described above were each tested for pour depressant potency by the Standard A. S. T. M. procedure in a mixture of extracted Mid-Continent-Neutral and extracted Mid-Continent Bright Stock of SAE 10 grade. The pour point of this base oil blend was +30 F. The same base oil was used in all the pour point determinations described.

The products of Example I were stable at -17 F. in the S. O. D. Pour Stability test described in Oil and Gas Journal, .vol. 46, page 89 (1947). It should be noted that although the weight of the condensate was 25% greater than that of the original phenol, the former has a higher A. S. T. M. potency than the latter. This means the potency of the pour depressant was improved by at least 25%. In addition to improved potency, the condensates are superior to wax phenols from which they are derived in that the former possess antioxidant properties which are absent in the Wax phenols.

It is not intended that this invention be limited to the specific materials which have been mentioned merely forthe sake of illustration but only by the appended claims in which it is intended to claim all novelty inherent in the invention as well as all modifications coming within the scope and spirit of the invention.

What I claim is:

1. A process which comprises modifying a Friedel-Crafts condensation product of a chlorinated wax and phenol, said condensation product having a molecular weight of at least 400, by reacting said condensation product with a beta-chloroethyl thioether containing an alkyl group having from 8 to 18 carbon atoms in the:

presence of aluminum chloride.

2. A process according to claim 1 wherein said thioether is beta-chloroethyl lauryl sulfide.

3. A product having the desirable characteristic of lowering the pour point of lubricatin oils with which it is blended which consists essentially of a Friedel-Crafts condensation product of chlorinated wax and phenol, said condensation product having a molecular weight of at least 400, which has been modified by reaction with a beta-chloroethyl thioether containing an alkyl group having from 8.to 18 carbon atoms in the presence of aluminum chloride.

4. A product according to claim 3 wherein said thioether is beta-chloroethyl lauryl sulfide.

LOUIS A. MIKESKA.

. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,143,142 Dietrich Jan. 10, 1939 2,201,814 Evans et al May 21, 1940 2,239,515 Bartlett et al. Apr. 22, 1941 2,266,737 Bruson et a1 Dec. 23, 1941 2,330,858 Anderson Oct. 5, 1943 2,352,435 Hoefielman et a1. June 27, 1944 2,488,134 Mikeska et al Nov. 15, 1949

Claims (1)

1. A PROCESS WHICH COMPRISES MODIFYING A FRIEDEL-CRARTS CONDENSATION PRODUCT OF A CHLORINATED WAX AND PHENOL, SAID CONDENSATION PRODUCT HAVING A MOLECULAR WEIGHT OF AT LEAST 400, BY REACTING SAID CONDENSATION PRODUCT WITH A BETA-CHLOROETHYL THIOETHER CONTAINING AN ALKYL GROUP HAVING FROM 8 TO 18 CARBON ATOMS IN THE PRESENCE OF ALUMINUM CHLORIDE.