US2425747A - Lubricating oil composition - Google Patents

Description

Patented Aug. 19, 1947 UNITED STATES PATENT OFFICE LUBRICATING OIL COMPOSITION Delaware No Drawing. Application July 6, 1940, Serial No. 344,232

'7 Claims. 1

This invention relates to a novel type of condensation products and to methods of preparing such products and using same, and more particularly for using such products as pour depressors in Waxy mineral lubricating oils.

Heretoforathe chief commercial method of making Friedel-Crafts condensation products which could be used as pour depressors in waxy lubricating oils, consisted in reacting a long chain aliphatic chlorinated hydrocarbon such as chlorinated paraffin wax, with an aromatic hydrocarbon such as naphthalene in the presence of aluminum chloride, as described in the Davis Patent 1,815,022. It is emphasized that the aliphatic compounds should have a long chain, preferably containing over or carbon atoms. The necessity of using a long chain aliphatic compound is also stressed in the Wiezevich Patent 2,128,109 and in the Graves Patent 2,111,769, where it is stated that halogenated paraffinic hydrocarbons of high molecular weight should be used, and in the British Patent 440,918 where parafilnic hydrocarbon material having at least 12 carbon atoms is specified. Also in the winning and Young Patent 2,045,742, the patentees describe their pour depressors as follows: Polymers produced by the condensation of oxygencontaining aliphatic materials with long paraffin chains such as alcohols and the like or the condensation of such materials in the presence of aromatics; and in the Gleason Patent 2,106,247, the patentee also refers to the use of alcohols containing relatively long hydrocarbon chains, 1. e. containing at least 10 or 12 carbon atoms and preferably even more.

Contrary to the above teachings of the prior art, applicants have now found that a new type of pour depressor can be prepared by starting with relatively low molecular weight aliphatic a1- cohols, i. e. having less than 10 carbon atoms, preferably less than 7 carbon atoms, by condensing them with aromatic compounds, preferably using a Friedel-Crafts condensation catalyst. Applicants have also found that contrary to the prior art, saturated alcohols can be used without either chlorinating or unsaturating them.

Accordingly, one object of the present invention is to make a new type of wax modifier suitable for use as a Pour depressor; another object is to develop new uses for lower molecular weight aliphatic alcohols, which may be obtained in relatively large quantity at low cost; another object is to eifect the direct chemical condensation of these low molecular weight alcohols with suitable aromatic compounds under proper conditions to obtain products suitable as pour depressors,

etc.

These and other objects and advantages of the invention will appear more clearly from the following specification.

Broadly, the process of the present invention comprises subjecting to a Friedel-Crafts condensation a low molecular weight aliphatic alcohol, preferably containing less than 7 carbon atoms, and an aromatic compound, preferably selected from a group consisting of aromatic hydrocarbons and oxy or hydroxy derivatives thereof, such as the phenolic compounds.

Examples of the alcohols which can be used include methyl alcohol, ethyl alcohol, normal propylalcohol, isopropyl alcohol, the butyl alcohols such as normal butyl alcohol, isobutyl alcohol, secondary butyl alcohol, the amyl alcohols, such as n-butyl carbinol, sec-butyl carbinol, dimethyl ethyl carbinol, methyl propyl carbinol and the hexyl alcohols. These may be used singly or in combination. In particular we have found the mixed amyl alcohol of commerce to be particularly useful. Other mixed alcohols may be used, such as those obtained, for instance, by hydration of a mixture of normally gaseous olefins, e. g. as obtained in the gaseous products formed during the cracking of heavier normally liquid petroleum fractions of the kerosene, gas oil or lubricating oil boiling range.

Of the various aromatic compounds which can be used, the hydrocarbon containing less than 4 aromatic nuclei are preferred, e. g. benzene, naphthalene, tetralin, diphenyl, cyclo-hexyl-phenyl, anthacene, phenanthrene, fluorene, chyrsene, toluene, Xylene, amyl-benzene, amyl-naphthalene and the like. j

Instead of using aromatic hydrocarbons per se, Various oxy-aromatic compounds can be used, such as phenol, benzyl phenol, resorcinol, o-hydroxydiphenyl, b-naphthol, p-cresol, hydroquinone, catechol, xylenol, phenyl ethyl phenol, methyl hydroxydiphenyl, guaiacol, the monethyl ether of catechol, methyl naphthol, tolyl naphthol, xylyl naphthol, benzyl naphthol, methoxyhydroxynaphthalene, anthrazole and the like.

The catalysts which are used to effect the reaction of the two classes of materials described above can be of several types. Of these the catalysts of the so-called Friedel-Crafts type are especially preferred, such as aluminum chloride, ferric chloride, zinc chloride, antimony chloride, antimony fluoride, stannic chloride, boron fluoride and others. Of these, aluminum chloride is preferred. Other types of catalysts may be used, such as sulfuric acid, hydrogen fluoride, activated clays, silica gel, metals such as metallic zinc, aluminum, etc.

In carrying out the invention, the two abovedescribed reagents are preferably mixed in simple molecular proportions, and in general, it is preferred to use between about 1 to mols of the low molecular weight alcohol to 1 mol of the aromatic compound, and the amount of catalyst to be used can vary within fairly wide limits, depending primarily upon the temperature used as well as upon the concentration of the reactants, but usually the amount of catalyst, such as aluminum chloride, should be between about 0.1 and 2.0 mols per mol of low molecular weight aliphatic alcohol used. and preferably the amount of catalyst will be between about 0.5 and 1.0 mol per mol of the alcohol.

Although not essential, it is desirable that a solvent be used during the reaction and this should be inert to the reactants taking part in the chemical condensation; such suitable solvents are refined kerosene, tetrachlorethane, carbon disulfide, nitrobenzene and others.

In the procedure to be used in carrying out the present invention it is preferable to mix the two reactants, namely the aromatic compound and the low molecular weight alcohol, with the solvent, and gradually add the catalyst, e. g., aluminum chloride. Usually a, vigorous reaction takes place, as is evidenced by the rapid evolution of hydrogen chloride gas, and if necessary the reaction vessel is cooled to prevent the temperature from rising above 200 F., but in any case, the temperature of the reaction mixture is finally increased to the vicinity of 150-250 F., by the application of heat if necessary, and maintained thereat for a period of about to 5 hours, or usually about 1 to 3 hours.

After the reaction has been substantially completed, the mixture is preferably cooled, e. g. to about 125 F., and then diluted with /2 to 10, preferably 1 to 3 volumes of refined kerosene as a diluent. The reaction mixture is then neutralized by adding, preferably slowly, a suitable hydrolyzing agent such as water, alcohol, or a mixturethereof, e. g., a 1:1 mixture of ethyl or iso-'- propyl alcohol and water. The mixture is then settled and the sludge resulting from hydrolysis of the catalyst is withdrawn and the kerosene extract, which may if desired be washed further, e. g., with an alcohol-water mixture, is then distilled as with fire and steam to about 600 F., to remove solvent and low boiling condensation products.

The above described order of procedure may be varied substantially if desired. For instance, onealternative procedure is to mix the aromatic compound with the solvent and then add the aluminum chloride and finally add the low molecular weight aliphatic alcohol slowly with stirring,

finally heating the reaction mixture until the desired condensation has been completed. Still other alternative ways of mixing may be used if desired, but in any case the reaction should be stopped before the production of substantial amounts of solid rubbery condensation products which are insoluble in mineral lubricating oils.

The products of the present invention range in physical properties from viscous oils to hard resinous solids, the color thereof varying fairly widely from green to brown. Without any desire to limit the invention to any particular theory as to the condensation reactions involved, the mechanism of which is not well understood, it is be- 1 lieved that the products of this invention may be considered to be compounds having the general chemical formula A1(R)n, in which Ar represents an aromatic nucleus, R represents a low molecular weight aliphatic hydrocarbon group, preferably an alkyl group, having less than 7 carbon atoms, and n represents an integer of more than 3 and preferably at least 5. For instance, in two cases, the products of this invention have been found by chemical analysis, molecular weight, etc., to be essentially pentamethyl naphthalene and hepta-ethyl naphthalene, respectively.

The products of this invention have been found to be particularly useful as pour depressors in waxy mineral lubricating oils, in which case, for instance, the addition of a small amount, e. g., 0.1% to 10.0% or preferably 0.2% to 5.0% of the condensation product to a waxy mineral lubricating oil having a pour point of about 30 F., causes the reduction of the pour point to about 0 F. or

even substantially therebelow, e. g., -10 F., F. or even F., depending upon the particular conditions used in effecting the condensation and depending upon the amount of pour depressor used and the type of lubricating oil into which it is incorporated, such as those derived from Pennsylvania type crude oils or other oils or fractions thereof which are rich in paraffinic type hydrocarbons.

A small amount of this condensation product which may be referred to in broad way as a wax modifier, is also useful as a dewaxing aid for removing wax from mineral lubricating oils of undesirably high wax content; and still further, similar small amounts of this wax modifier may be incorporated into paraffin wax or compositions containing same to be used for various purposes such as for coating and impregnating paper, etc. or for making various molded wax products.

For the sake of illustration but without desiring to limit the invention to the particular materials, proportions or reaction conditions used, the following table of experimental data are given:

Table 1 Product Solvent I V Arum. Compd. Aliph. Alc. cc Point o F 2 lfg g Hrs. Percent Product Yield Nature Added Name gm. Name gin. (k) (t) l 2 5 1 Benzene 88 200 275 200 3 52 Vlsc. green oil l5 2 d0 88 200 275 200 3 71 -25 3 Naphthalene. 88 200 275 180 3 M4 20 4 Diphenyl 88 200 275 1% 206 Dark red resin -50 5. Naphthalene. 'Sec.buty1 74 200 275 180 1 Vise. red green oil 20 6 o 128 Isopropyl.-. 65 200 275 1 149 do l5 Pour points of original oils were: test N o. 8, +10 F.; test No. 15, +20 F. k-Kerosene.

tTetra cl ethane. 9 Original oil, pour point +30 F., unless otherwise indicated.

Table 1Contm.ued

, Product T t Arom. Qompd. Ahph. Ale. g Point g g o fi Hrs. Percent Product Yield Nature Added N ame gm Narne gm (k) (t) 1 2 5 7. N aphthalehe. Sec. amyl- 275 150 4. 5, 188 Vise. red green oil do Methyl- 275 175 2 120 Visc. green brown oil do 275 175 2 44 Visc. green oil 275 175 2, 140 Vise. green brown oil 275 175 2 129 do 138 175 2 l e 94 do 275 1-75 2 91 do 275 190 2 139 Vise. green oil. 275 190 '2 52 d0 do 275 190 2 79 Deep green v Mixed amyl. 275 200 2 .94 Brown resin- Meth 275 200 2 i 28 Brown waxy Isopropyl. 275 200 2 44 Visa. green oil. Mixed amyl. 275 200 2 90 Vise. brown green oil. 275 200 2 44 Brown resin 1 Pour points of original oils were: test No. 8, F test 0. l5, F.

t-Tetra cl ethane.

2 Original oil, pour point F., unless otherwise indicated.

Although the nature of the raw materials used and the reaction conditions used, were varied as indicated in the above Table 1, the same general type of procedure was used throughout all of the tests; and for the sake of illustration this will be explained as applied to the first example (i. e. test 1).

In a suitable reactor equipped with a mechanical stirrer, thermometer, reflux condenser and dropping funnel were placed '78 grams of benzene, 200 cc. of kerosene as solvent and 275 grams of anhydrous aluminum chloride. The stirrer was started and the reaction flask was cooled with a bath of running cold water. 88 gramsof secondary amyl alcohol were now slowly added to the reaction mixture over a period of 30 minutes. After the addition of the amyl alcohol the cold water bath was removed, and the reaction temperature slowly increased to 200 F. and maintained thereat for 3 hours. Vigorous reaction took place as evidenced by the very heavy evolution of hydrogen chloride gas. After cooling to about 125 F. the reaction mixture was diluted with kerosene and neutralized by slowly adding about 1 liter of a mixture of alcohol and water. After settling and withdrawal of the aluminous sludge, the kerosene extract was washed further with the alcohol-water mixture and then distilled with fire and steam to 600 F. to remove solvent and low-boiling products. A bottoms residue comprising 52 grams of a very viscous green oil was obtained as product.

In an attempt to ascertain the nature of several of the products of the present invention, the following analytical data were obtained:

1 Original poor is +80 F. Test oil comprises a blend of 10 parts 0; Bright Stock and 90 parts of Manchester Spindle.

Based on the above analytical data, the following average structural formulae are suggested as possibly being the correct ones to represent the product described in those cases, although it should be understood of course that no attempt has been made to determine the precise position of the various substituent groups.

It is not intended that this invention be limited to any of the specific examples which were given merely for the sake of illustration nor to any theory as to the mechanism of the operation of the invention but only by the appended claims in which it is intended to claim all novelty inherent in the invention as broadly as the prior art permits.

We claim:

1. A lubricating composition comprising a major proportion of a lubricating oil base stock and a small amount of a condensation product of an aliphatic mono-hydroxy alcohol having less than 7 carbon atoms and an aromatic compound having less than 4 aromatic nuclei, said condensation product being substantially non-volatile at about 600 F. under reduced pressure and having the property of depressing the pour point of waxy mineral lubricating oils when added thereto in small amounts,

2. A lubricating composition comprising a major proportion of waxy mineral lubricating oil and a small amount of a condensation product of an alcohol having the general formula R-OH, in which R is an alkyl group having less than 7 carbon atoms, and an aromatic compound having less than 4 aromatic nuclei and selected from the group consisting of aromatic hydrocarbons and their hydroxy derivatives, the said condensation product having the property of depressing the pour point of waxy mineral lubricating oils when added thereto in small amounts and being substantially non-volatile at about 600 F. under fire and steam distillation and essentially a compound having an aromatic nucleus to which are attached at least 3 low molecular weight alkyl groups.

3. A lubricating composition comprising a major proportion of a waxy mineral lubricating oil and a small amount of a polyamylated naphthalene substantially non-volatile at about 600 F. under fire and steam distillation and containing at least 3 amyl groups for each naphthalene nucleus.

4. A lubricating composition comprising a major proportion of a waxy mineral lubricating oil and a small amount of a chemical compound substantially non-volatile at about 600 F. under fire and steam distillation and having the propcity of depressing the pour point of waxy mineral lubricating oils when added thereto in small amounts and having the general formula Ar-R in which Ar represents an aromatic nucleus, R represents an aliphatic hydrocarbon group having less than 7 carbon atoms and n is an integer of at least 3.

5. A lubricant comprising a lubricating oil base stock and a small amount of hepta-ethyl naphthalene.

6. A lubricant comprising a major proportion of waxy mineral lubricating oil and a small but pour-depressing amount of a Friedel-Crafts condensation product of an aliphatic alcohol having less than 7 carbon atoms and an aromatic compound having less than 4 aromatic nuclei, said condensation product having the property of depressing the pour point of waxy mineral lubricating oils when added thereto in small amounts and being substantially non-volatile up to 600 F. under fire and steam distillation.

'7. A lubricant comprising a major proportion REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 17,548 Michel Dec. 31, 1939 2,072,107 Fulton et al Mar. 2, 1937 2,141,593 Clarke Dec. 27, 1938 2,147,315 Pier Feb. 14, 1939 2,072,120 Mikeska Mar. 2, 1937 1,990,985 Fonrobert Feb. 12, 1935 2,028,472 Rabe Jan. 21, 1936 1,908,190 Schollkopf May 9, 1933 OTHER REFERENCES Organic Reactions with Boron Fluoride, XIII, The Alkylation of Benzene with Alcohols, McKenna and Sowa, 2 pages, March, 1937. (Copy in Div. 31.)

Methods for the alkylation of Benzene, Shen., vol. 26, Journal Inst. Pet., page 475, Oct. 1940. (Copy in Div. 31.)

Chemistry of Petroleum Derivatives, Ellis, vol. 2, Reinhold Publishing Co., 1937, page 138. (Copy in Div. 31.)