US2536684A - Sulfurized product and preparation thereof - Google Patents

Description

Patented Jan. 2, 1951 a SULFURIZED'PRODUCT AND PREPARATION THEREOF Denham Harman and William E. Vaughan, Berkeley, Qalifi, assignors toShell Development Company, San Francisco, Calif., a corporation I of Delaware i No Drawing. Application June 2, 1947, Serial No. 751,976

9 Claims. (c1. 252-es.s)

' l his invention relates to novel products and phorus linkages. Still" in accordance with this to their preparation and use. More particularly invention it has been found that such products 'it pertains to the-use of certain sulfur containmay be prepared by heating the two ingredients ing linear polymers especially useful as synthetic together, either alone or in the presenceof al- E lubricants or as lubricant additives. 5 solvent for one or more of the ingredients of the Mineral oil fractions are suitable for many reaction mixture or of a solvent for the products lubricating purposes, but itis well known that prepared. Again-in accordance with this invensuch lubricants possess certain inherent limitation, it has been found that these sulfurized polytions such as tendency to oxidize, thickening at mers have excellent lubricating characteristics low; temperatures and poor inherent lubricating and inherently possess extreme pressure propercharacteristics under conditions of relatively exties. Still in accordance with this invention, it

' treme pressure such as in hypoid gear lubricahasbeen found that the subject sulfurizedpolyq'.

tion, A large number of additives have been mers'may be used in combination with lubricat employed with mineral oils in order to improve ingmaterialsin order to enhance the extreme these shortcomings with a certain degree of pressure properties and other characteristics success. thereof. Various synthetic materials have been pro- Polymers which may be sulfurized for the pur posed for use as synthetic lubricants. These inpose of thepresent invention include especially clude polymers of cracked wax olefins and those prepared from alkylene oxides and alkylene' alkylat'ed aromatics such as alkylated naphthaglycolsr a lenesg Some of these are useful for special pur- Alkylene oxid s, and particularlyv theralkylene poses but, especially if the synthetic lubricants oxides having the oxygen bound to adjacent car are derived from olefinic, sources, they usually bon atoms, form polymers of the above conpossess corrosion and'oxi'dation characteristics figuration. These monomeric Oxides have the limiting their utilization to a substantial degree. 5 general Configuration Another type of synthetic lubricant which has 4 been investigated is the alkylene oxide polymer i type such-as polymerized propylene. oxide. This latter type of synthetic lubricant is suitable for even moderate extreme pressure conditlons are wherein thlfree valencesi s e i ahsjf use only under mild operating conditions. Ii I w encountered this type of polymeric lubricant fails drogens brg'anic radicals to function satisfactorily and results in rapid a I wear of the machinery or engine being lubricated. fig g g fgg 222 2 22 23 gggg r ig It is an 9 of-this invention to provide novel butylene oxide 2 3-b'utylene oxide isobutylehe 1 g;fgififi ggg gs is another 2 oxide, tetramethylethylene oxide, methylphenyl- J p 9 t process 0 ethylene oxide, cyclohexene oxide, methylcyclothe product1on of such materials. It is a further hexane oxide 1 2 cetene oxide. and other W of E mventlon to proYlde novel. y stances-containing theepoxide linkages such as l l a A further 9 9 of thls 40 eoichlorohydrin epibromohydrin and glycides Ventlon 13 t9 Provlde .novel addmves for lubricat' such as'glycidofand l 2-epoxy-2-butanol as well mg m l sald additives providing l h as derivatives and polymerlzable homologs and 9 i extreme pressure propertles analogs of the aforementioned substances other ObJeFtS become apparent during the Copolymers of the alkylene oxides useful in l i dlscusswn' compositions of the present invention include for v ow in accordance with this invention, it has example the copolymer-s of ethylene oxide and been found that polymers r f r units propylene oxide; and copolymers of ethylene mg the general configuratmn. v oxide and isobutylene oxide; the copolymers of '.(O. .R) e r propylenejoxide and epichlorohydrin; the'flco- I 59 polymers of propylene oxide and l,-2butylene wherein R is an-organlc radical (especially a oxide; the copolymers. of propylene oxide and hydrocarbon radical) may be converted to more glycidol; ,and thecopolymersofpropylene oxide useful products by reaction with sulfur, with and isobutylene oxide. V 1 Q] compounds containing sulfur tohalide linkages Polymers similar tol those above are. form d or with compounds containing sulfur to phosfromlthe alkylene glycols, including the poly-l methylene glycols and the ethyleneoglycols. The monomeric and lower polymeric glycols have the general configuration wherein n is an integer and R1 and R2 are hydrogens or organic radicals. V

If R1 and/or R2 are not hydrogen atoms, they may be organic radicals such as alkyl, aralkyl, aryl, etc. Preferably, if they are not hydrogens, they are aliphatic radicals, especially saturated lower aliphatic radicals, but may also be groups which contain olefinic or acetylenic links. Typical of the trimethylene alkyl substituted glycols are the methylated trimethylene glycols, including 1 methyl-1,3-propanediol; '2 methyl 1,3- propanediol; 1,1-dimethy1-=1,3-propanediol; 1-,2- dimethyl 1,3 propanediol; 1,3 dimethyl 1,3- propanediol; 2,2-dimethyl-1,3-propanedio1; 1,1,2- trimethyl--l.,3 propanediol; 1,1,3 9 trimethyl- 1,3- propanediol; 1,2,2 trimethyl 1,3 propanediol; 1,2,3 trimethyl 1,3-propanediol; l,1,2,2-tetramethyl-1,3-propanediol; 1,'1,3-,3-tetramethyl-1,3- propanediol; 1,2,3,3-tetramethyl 1,3 propanediol; 1,1,2,2,3 pentamethyl 1,3 propanediol; 1,1,2,3,3-pentamethyl-1,3-propanediol; and hexamethyl-LS-propanediol. a

In place of the methyl groups other alkyl groups may be utilized such as ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, etc., as well as their isomers. Preferably, when alkyl groups are the substituents R1 and R2, they have from 1 to 10 carbon atoms, and still more preferably from 1 to 5.

It will be understood that R1 and R2 may be similar or dissimilar groups. Thus, when expending the general formula given hereinbefore to its indicated number of carbon atoms, it then becomes 7 R: R4 R0 11o- -on wherein R3 through Rs are either hydrogen atoms orsimilar or dissimilar organic radicals. Those derivatives of trimethylene glycol, other than trimethylene glycol itself, which gives the most satisfactory polymers for general use have either one or two of the Rs as lower alkyl groups. Thus, 2 methyl 1,3 propanediol and 2,2 dimethyl=1,3-propanediol form excellent polymers when treated according to the method of the present invention.

other lower alkyl substituted 'trimethyiene glycols which polymerize readily are 1-methyl-2- ethyl-L3-"propanediol; 2-methyl 2 ethyl 1,3- p'ropanediol; 1-methyl- 3-ethyl -1,3-propanedioli 2-methyl-2-propyl-l,3-propanediol; 'l-methyl-2= isopropyl-1,3*propanediol 2-methyl-2-butyl-l,3- propanediol; 2 methyl='3-butyl 1,'3 propanediol;

4 and homologs, analogs and derivatives of the; same.

Cycloaliphatic radicals may be one or more of the substituents represented by R3 to Rs in the above general formula. Thus R3 through Ra may be such radicals as cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, ethylcyclohexyl, etc. However, open chain alkyl substituents form polymers having preferred properties.

The polymers have modified properties if the trimethylene glycol derivative contains other active groups, such as additional hydroxyls, carboxyls, carbonyls, halogens, sulfur, phosphorus, nitrogen, etc.

Polymethylene' glycols having 6 or more carbon atoms separating the glycollic hydroxyls also form polymers and copolymers which are readily improved by the present process.

The polymethylene glycols from which such polymers are prepared have the general formula tually, when Z is more than 1, the glycol is a dimer, trimer, etc, of the corresponding monomeric glycol. The polymethylene glycols polymerizing most readily are those in which 1 is an integer from 6 to 20.

Monomeric, unsubstituted polymethylene glycols falling within the above formula include 1,6- hexanediol; 1,7-hept2an'ediol; 1,8-octanediol; 1,9- non'anediol; 1,1 0-decanediol; 1,12-dodeca'nedi0l: and polymerizable homologs, analogs andderivatives of the same.

The above glycols are those in which all of the R substitue'nts attached to the carbon atoms are hydrogen atoms. When one or more of the Ra's are substitu'ents other than hydrogen atoms they may be hydrocarbon radicals, such as aliphatic, aromatic, or aiicyclie hydrocarbon radicals, or radicals containing non-hydrocarbon members, such as hydroxyl, 'carboxyl, or carbonyl groups, or sulfur, selenium, telluriu'ni, phosphorus or nitrogen atoms. Preferably, however, any organic radicals attached to the polymethylene glycol are hydrocarbon radicals. Of these, the aliphatic hydrocarbons are preferred, and the saturated lower aliphatic radicals give the most stable polymers and have the widest utility. Hence, the preferred Rs, other than hydrogen, are the lower alkyls, such as methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl, tertbutyl, amyl, iso-arnyi, heiryl, etc. group's- Again, even when Rs other than hydrogen are present, it is preferred that the monomeric glycol contain a preponderance of hydrogen substituent Rs. The most reactive glycols are those in which less than 4 Rs are other than hydrogen, and the greatest reactivity is possessed by those having 2 or less Rs which are organic radicals.

Glycols which fall Within the above classification include LS-heptanediol; LB-octanediol; l d-nonanediolg Ld-dodecanediol; 1,6-decanediol; III-octanediol; 1,'7=nonanediol; 1,7-decanediol; l,'7-d'odecanediol; 1,8-nonanediol; 1,8-deca'nedi'ql'; LQ-decan'ediOl; 1,9-dodecan'ediol; "l,10-dodecane-" diol; 2,7-octanediol; zfi-nonan'ediol; 2,7-decanediol; gfl-dodecan'ediol; 2,8-no'nanediol; 2,8-dec-y assess;

anediol; 2,8-dodecanediol; 2,9-decanediol; 2.9- dodecanediol; 2,3-dimethyl-1,6-hexanediol; 2,4 dizhethyl-LG-hexanediol; 2,5-dimethyl-1,6-hxanediol; 4,4-dimethyl 1,6-hexanediol; 5,5-dimethyl 1,6-hexanediol; 2-methyl-3-ethyl-L7 heptanediol; 2-ethyl-3-methyl-l,7-heptanediol; 3,3-diethyl-1,7-heptanediol; 3,4-diisopropyl-1,8- octanediol; etc. and their polymerizable homologs, analogs and derivatives.

- The polymers described hereinbefore may be homopolymers or-may be copolymers. For example, an ethylene glycol may be copolymerized with a trimethylene glycol to give copolymers having units of the general configuration wherein m and 01. are integers and the free valences within the brackets are satisfied with hydrogen atoms or organic radicals. These include copolymers of ethylene glycol and trimethylene glycol; ethylene glycol and l-methyl-l, 3-propanediol; ethylene glycol and 2-methyl-1,3-propanediol; ethylene glycol and 2,2-dimethyl-1,3- propanediol; ethylene glycol and l,3-diethyl-l ,3- propanediol; 1,2-dimethylethylene glycol and trimethylene glycol; 1,2-dimethylethylene glycol and 1,3-dibutyl-1,3-propanediol, etc. Other copolymers falling within the'general formula of substances stabilized according to the present invention include the copolymers of an ethylene glycol or a trimethylene glycol with a polymethylene glycol having more than 5 carbon atoms separating the glycollic hydroxyls. These copolymers have units of the general configuration le-eweser wherein m, n, pand y are integers, and the free valences are satisfied with hydrogen atoms or organic radicals. These include for example, copolymers of ethylene glycol and hexamethylene glycol; trimethylene glycol and hexamethylene glycol, etc. The alkylene oxides usually are polymerize at temperatures from about -60 C. to about 100 C. in the presence of alkalies, acids, amines or salts. The glycols are polymerized at higher temperatures (150-300" C.) in the presence of dehydration catalysts, such as iodine, mineral acids, such as nitric acid or sulfuric acid, hydrogen halides such as hydrogen iodide or hydrogen chloride; or organic sulfonic acids such as paratoluene sulfonic acid.

In producing the sulfurized polymers according to the process of the present invention,"it is preferred practice to heat one or more of the polymers at a temperature from about 50 C. to about 200 C. for a period of about 3 to 5 hours with an agent or agents from the group consisting of sulfur, sulfur compounds containing sulfur to halide linkages, and sulfur compounds containing sulfur to phosphorus linkages. Typical members of this group include sulfur monochloride, sulfur dichloride and phosphorus pentasulfide as well as their homologs. The two ingredients of the reaction mixture, namely the polymer and the sulfur or sulfur compound, may be heated in the absence of other materials or in the presence of solvents for one or more of the ingredients or products. Suitable solvents include chlorinated hydrocarbons, unsaturated aliphatic compounds such as hydrocarbons or alcohols, etc.

" The proportion of sulfur or sulfur compound to the polymer may vary within relatively wide limits depending upon the purpose for which the product is intended. If the product is to be used as a synthetic lubricant it is preferred that the proportion of sulfur to polymer be within the range from about 1% to about 20% by weight of the polymer. However, higher or lower percentages of the sulfur or sulfur compound may be employed. In order to obtain a synthetic lubricating material having satisfactory extreme pressure properties at high loads it is usually preferred that the percentage of sulfur be from about 3% to about 10%, basedon the weight of the polymer. For exceptional cases sulfur con--- taining up to about 30% or more may be obtained.

- Under normal operating conditions it is advisable to employ an amount of sulfur in excess of that amount with which it is desired to modify the polymer. By the use of such an excess the rate of reaction is increased to a satisfactory degree. If an excess is used it becomes necessary at the end of the heating period to separate the unreacted sulfur or sulfur. compound from the modified polymeric material.v Ordinarily the excess agent will remain in suspension and may be separated by a filtration or centrifuging operation. Under some conditions however, the excess agent dissolves in the polymer and, if it is necessary to separate therefrom, it must be removed by such means as solvent extraction. For manylu-.

bricating purposes an excess of sulfur is not objectionable if it is dissolved in the body of the lubricant.

The sulfurizing operation normally may be effected without undue discolorization or other adverse effects on the subject polymers. However, it may be desirable to colorize 0r decolorize the product by subjecting it to an operation such as filtration through activated carbon, treatment with an absorbent clay or by chemical means of decolorization.

The products obtained by the sulfurization of polymers such as those described above, are solids or liquids useful for a number of purposes. The solids are particularly effective as extreme pressure additives in lubricants, while the liquid members of the sulfurized series are effective not only as extreme pressure additives but as lubricants themselves. lubricating characteristics, having high viscosity indices and low pour points.

Lubricants which may be modifiedby the addition of a solid or liquid sulfurized polymer as described hereinbefore include Oleaginous materials such as mineral oils, fatty oils, vegetable oils such as corn oil, cottonseed oil and castor oil; animal oil such as neats-foot oil; and fish oils such as sperm oil. Oleaginous materials whenmodified by such means as halogenation, hydrogenation, alkylation and other means may be modified by the sulfurized polymers of the present invention. Depending upon the application intended, oleaginous materials of extreme low or extreme high viscosities may be used successfully. Lubricating oils of a viscosity from about 30 seconds at F. to about 250 seconds at 210 F. and higher may be used if desired. Furthermore, parafiinic, naphthenic, asphaltic base oils or carbons or mixtures may be used in combination with the sulfurized polymers. I

A special type of lubricant which is particularly suited to modification with the subject sulfurized polymers includes lubricants comprising or de- The oily products have satisfactory rived from the alkylene oxide or alkylene glycol polymers listed above. These polymers may be the same as the polymers from which the sulfurized materials are derived or they may be different members of the same class. A particularly desirable means of preparing lubricating compositions of this variety comprises treating such polymers with a minor amount of sulfur or sulfur compounds as listed hereinbefore so as to produce in situ a polymeric lubricant, a minor amount of which is in a sulfuri'zed condition. It will be considered within the scope of this invention that the sulfuriz'ation may be complete or at anystage short of completion so that a. greater or less amount of the main body of the polymeric lubricant is in a sulfurized state.-

The lubricating compositions of this invention may contain other'modifying ingredients such as gelling agents. stabilizers, anti-corrosion agents, viscosity index improvers, thickener, and the like. Particularly suitable gelling agents for polymeric alkylene oxides or glycols which contain or comprise sulfurized-polymers are lithium soaps of the higher fatty acids such as lithium stearate.

The use of these sulfurized polymers either in or as lubricants is particularly suitable where extreme pressure or heavy duty conditions prevail. It has been discovered that by the sulfurization as described hereinabove pressure characteristics are'imparted to the alkylene oxide and glycol polyiners. The examples which followdescribe the preparation and use of this invention. It is not intended that the invention be limited specifically to these examples but that they be treated as specific illustrations thereof.

Example I 100 parts of a polymerized propylene oxide were heated with parts by weight of flowers of sulfur at a temperature of 170 C. for 3 hours. The prodnot was a cloudy oil which was clarified by filtration. It had the following characteristics:

Example II "100 parts of a 'copolymer of trimethylene glycol and diethylene glycol was heated with 5 parts by weight of flowers of sulfur at a temperature of 190C. for 5 hours. The product was filtered to give a clear light yellow oil having the following h properties:

Sulfur, per cent by weight 2.02 Mercapta'n sulfur, per cent by weight 0.6 Viscosity index l- 1'25 Pour point, F l l -35 Ercmple III Sulfur, per cent by weight 0.90 Chlorine, .per cent by weight (3.56 viscosity index l 145 point. F..-...-

Example I V parts by weight of a polymer of propylene oxide was heated with 5 parts by weight of sulfur dichloride at a temperature of 185 C. for a period of 3 hours. The product was filtered to yield an odorless yellow oil having the following properties:

Sulfur, per cent by weight -1 0.64; Chlorine, per cent by weight 0.58 Viscosity index .145 Pour point, "F -3 I ExampleV Viscosity index Q... Pour point, F l0 Example VI The non-sulfurized and suifurized polymers de-fscribed in Examples 1 through 5 were treated for extreme pressure properties, using the 4 ball machine described by Bo'elage in Engineering" (July 14, 1933). The following table represents the data obtained:

Wear in mm. at Various Loads (kgs) Lubricant v Polymerized:

Propylene oxide- 0.57 1.63 2. 50 W Propylene oxide Sulfur 0. 611261.215 1. 61 1. 63 1. 69 1.861.88 Propylene oxide +SC]: 1.04 1.56 1.84 1. 94 2.06 2. 16 .W Propylene oxide +SzClz 0.98 1. 21 1. 781. 871.88 2. 01 W Propylene oxide I y g 0.86 2. 45 5. 09 Copolymer of tri 1 methylene glycol and ethylene gly- 1 col 1--.-.. 0.40 0.45 1.91 2. W Ethylene glycol-l-S. 1.39 1. 92 1.66 ..--e 1. 91 211 W indicates welding.

We claim as our invention:

1. The process which consists essentially of heating a polymer having recurring units of the general configuration wherein R is an alkylene hydrocarbon radical, with an agent selected from the'group consisting of sulfur, compounds containing sulfur to chlorine linkages and compounds containing sulfur to phosphorus linkages for a period of 3 to 5 hours at a temperature between 50 and 200 (3., the amount of said agent being sufficient to impart a sulfur content of l to 30% by weight of said polymer to the reaction product.

2. The reaction products prepared according to the process of claim 1.

3. The process which consists essentially of heating 100 parts by weight of a copolymer of trimethylene glycol and diethylene glycol with 5 parts by weight of sulfur at a temperature of 190 C. for 5 hours.

s. The process which consists essentially of heating 100 parts by weight of a propylene oxide polymer with 5 parts by weight of sulfur at a temperature of C. for 3 hours.

5. The process which consists essentially of heating 100 parts by weight of a propylene oxide polymer with 5 parts by weight of phosphorus pentasulfide at 190 C. for 5 hours.

6. A lubricating composition comprising a major proportion of an alkylene glycol polymer and a minor amount, suflicient to impart extreme pressure properties to said composition, of

a polymeric alkylene glycol reaction product with sulfur, said reaction product being prepared by the process of claim 1.

'7. A lubricating composition comprising a major proportion of an alkylene oxide polymer and a minor amount, suflicient to impart extreme pressure properties to said composition, of a polymeric alkylene oxide reaction product with sulfur, said reaction product being prepared by the process of claim 1.

8. A lubricating composition comprising a major proportion of a mineral oil lubricant and a minor amount, suificient to impart extreme pressure properties to said composition, of a polymeric alkylene oxide reaction product with phosphorus pentasulfide, said reaction product being prepared by the process of claim 1.

9. A lubricating composition suitable for use as an extreme pressure lubricant comprising a major proportion of an oleaginous lubricant and a minor amount, sufiicient to impart extreme pressure properties to said composition, of the reaction product of an oxyalkylene polymer with an agent of the group consisting of sulfur, compounds containing sulfur directly attached to a halogen atom and compounds containing sulfur directly attached to a phosphorus atom, said reaction product containing 1 to 30% by weight of sulfur based on the weightof the polymer, said product having been prepared according to the process of claim 1.

' DENHAM HARMAN.

WILLIAM E. VAUGHAN.

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

UNITED STATES PATENTS Adams et a1. Mar. 27, 1945 Toussaint et al. Aug. 19, 1947 Ballard et a1 Oct. 11, 1949 OTHER- REFERENCES Synthetic Organic Chemicals, page 23, 12th ed., published by Carbide and Carbon Chemical Corp, July 1, 1945.

Dachlauer at al. Oct. 5, 1937 Hughes et a1 Aug. 14, 1945 Morgan et al Oct. 15, 1946

Claims (2)

1. THE PROCESS WHICH CONSISTS ESSENTIALLY OF HEATING A POLYMER HAVING RECURRING UNITS OF THE GENERAL CONFIGURATION @SP -(O-R)@SP WHEREIN R IS AN ALKYLENE HYDROCARBON RADICAL, WITH AN AGENT SELECTED FROM THE GROUP CONSISTING OF SULFUR, COMPOUNDS CONTAINING SULFUR TO CHLORINE LINKAGES AND COMPOUNDS CONTAINING SULFUR TO PHOSPHOROUS LINKAGES FOR A PERIOD OF 3 TO 5 HOURS AT A TEMPERATURE BETWEEN 50* AND 200* C., THE AMOUNT OF SAID AGENT BEING SUFFICIENT TO IMPART A SULFUR CONTENT OF 1 TO 30% BY WEIGHT OF SAID POLYMER TO THE REACTION PRODUCT.

6. A LUBRICATING COMPOSITION COMPRISING A MAJOR PROPORTION OF AN ALKYLENE GLYCOL POLYMER AND A MINOR AMOUNT, SUFFICIENT TO IMPART EXTREME PRESSURE PROPERTIES TO SAID COMPOSITION, OF A POLYMERIC ALKYLENE GLYCOL REACTION PRODUCT WITH SULFUR, SAID REACTION PRODUCT BEING PREPARED BY THE PROCESS OF CLAIM 1.